1.. SPDX-License-Identifier: CC-BY-SA-2.0-UK 2 3****************** 4Variables Glossary 5****************** 6 7This chapter lists common variables used in the OpenEmbedded build 8system and gives an overview of their function and contents. 9 10:term:`A <ABIEXTENSION>` :term:`B` :term:`C <CACHE>` 11:term:`D` :term:`E <EFI_PROVIDER>` :term:`F <FEATURE_PACKAGES>` 12:term:`G <GCCPIE>` :term:`H <HOMEPAGE>` :term:`I <ICECC_DISABLED>` 13:term:`K <KARCH>` :term:`L <LABELS>` :term:`M <MACHINE>` 14:term:`N <NATIVELSBSTRING>` :term:`O <OBJCOPY>` :term:`P` 15:term:`R <RANLIB>` :term:`S` :term:`T` 16:term:`U <UBOOT_CONFIG>` :term:`V <VOLATILE_LOG_DIR>` 17:term:`W <WARN_QA>` :term:`X <XSERVER>` 18 19.. glossary:: 20 :sorted: 21 22 :term:`ABIEXTENSION` 23 Extension to the Application Binary Interface (ABI) field of the GNU 24 canonical architecture name (e.g. "eabi"). 25 26 ABI extensions are set in the machine include files. For example, the 27 ``meta/conf/machine/include/arm/arch-arm.inc`` file sets the 28 following extension:: 29 30 ABIEXTENSION = "eabi" 31 32 :term:`ALLOW_EMPTY` 33 Specifies whether to produce an output package even if it is empty. 34 By default, BitBake does not produce empty packages. This default 35 behavior can cause issues when there is an 36 :term:`RDEPENDS` or some other hard runtime 37 requirement on the existence of the package. 38 39 Like all package-controlling variables, you must always use them in 40 conjunction with a package name override, as in:: 41 42 ALLOW_EMPTY:${PN} = "1" 43 ALLOW_EMPTY:${PN}-dev = "1" 44 ALLOW_EMPTY:${PN}-staticdev = "1" 45 46 :term:`ALTERNATIVE` 47 Lists commands in a package that need an alternative binary naming 48 scheme. Sometimes the same command is provided in multiple packages. 49 When this occurs, the OpenEmbedded build system needs to use the 50 alternatives system to create a different binary naming scheme so the 51 commands can co-exist. 52 53 To use the variable, list out the package's commands that are also 54 provided by another package. For example, if the ``busybox`` package 55 has four such commands, you identify them as follows:: 56 57 ALTERNATIVE:busybox = "sh sed test bracket" 58 59 For more information on the alternatives system, see the 60 ":ref:`ref-classes-update-alternatives`" 61 section. 62 63 :term:`ALTERNATIVE_LINK_NAME` 64 Used by the alternatives system to map duplicated commands to actual 65 locations. For example, if the ``bracket`` command provided by the 66 ``busybox`` package is duplicated through another package, you must 67 use the :term:`ALTERNATIVE_LINK_NAME` variable to specify the actual 68 location:: 69 70 ALTERNATIVE_LINK_NAME[bracket] = "/usr/bin/[" 71 72 In this example, the binary for the ``bracket`` command (i.e. ``[``) 73 from the ``busybox`` package resides in ``/usr/bin/``. 74 75 .. note:: 76 77 If :term:`ALTERNATIVE_LINK_NAME` is not defined, it defaults to ``${bindir}/name``. 78 79 For more information on the alternatives system, see the 80 ":ref:`ref-classes-update-alternatives`" 81 section. 82 83 :term:`ALTERNATIVE_PRIORITY` 84 Used by the alternatives system to create default priorities for 85 duplicated commands. You can use the variable to create a single 86 default regardless of the command name or package, a default for 87 specific duplicated commands regardless of the package, or a default 88 for specific commands tied to particular packages. Here are the 89 available syntax forms:: 90 91 ALTERNATIVE_PRIORITY = "priority" 92 ALTERNATIVE_PRIORITY[name] = "priority" 93 ALTERNATIVE_PRIORITY_pkg[name] = "priority" 94 95 For more information on the alternatives system, see the 96 ":ref:`ref-classes-update-alternatives`" 97 section. 98 99 :term:`ALTERNATIVE_TARGET` 100 Used by the alternatives system to create default link locations for 101 duplicated commands. You can use the variable to create a single 102 default location for all duplicated commands regardless of the 103 command name or package, a default for specific duplicated commands 104 regardless of the package, or a default for specific commands tied to 105 particular packages. Here are the available syntax forms:: 106 107 ALTERNATIVE_TARGET = "target" 108 ALTERNATIVE_TARGET[name] = "target" 109 ALTERNATIVE_TARGET_pkg[name] = "target" 110 111 .. note:: 112 113 If :term:`ALTERNATIVE_TARGET` is not defined, it inherits the value 114 from the :term:`ALTERNATIVE_LINK_NAME` variable. 115 116 If :term:`ALTERNATIVE_LINK_NAME` and :term:`ALTERNATIVE_TARGET` are the 117 same, the target for :term:`ALTERNATIVE_TARGET` has "``.{BPN}``" 118 appended to it. 119 120 Finally, if the file referenced has not been renamed, the 121 alternatives system will rename it to avoid the need to rename 122 alternative files in the :ref:`ref-tasks-install` 123 task while retaining support for the command if necessary. 124 125 For more information on the alternatives system, see the 126 ":ref:`ref-classes-update-alternatives`" section. 127 128 :term:`ANY_OF_DISTRO_FEATURES` 129 When inheriting the 130 :ref:`features_check <ref-classes-features_check>` 131 class, this variable identifies a list of distribution features where 132 at least one must be enabled in the current configuration in order 133 for the OpenEmbedded build system to build the recipe. In other words, 134 if none of the features listed in :term:`ANY_OF_DISTRO_FEATURES` 135 appear in :term:`DISTRO_FEATURES` within the current configuration, then 136 the recipe will be skipped, and if the build system attempts to build 137 the recipe then an error will be triggered. 138 139 140 :term:`APPEND` 141 An override list of append strings for each target specified with 142 :term:`LABELS`. 143 144 See the :ref:`grub-efi <ref-classes-grub-efi>` class for more 145 information on how this variable is used. 146 147 :term:`AR` 148 The minimal command and arguments used to run ``ar``. 149 150 :term:`ARCHIVER_MODE` 151 When used with the :ref:`archiver <ref-classes-archiver>` class, 152 determines the type of information used to create a released archive. 153 You can use this variable to create archives of patched source, 154 original source, configured source, and so forth by employing the 155 following variable flags (varflags):: 156 157 ARCHIVER_MODE[src] = "original" # Uses original (unpacked) source files. 158 ARCHIVER_MODE[src] = "patched" # Uses patched source files. This is the default. 159 ARCHIVER_MODE[src] = "configured" # Uses configured source files. 160 ARCHIVER_MODE[diff] = "1" # Uses patches between do_unpack and do_patch. 161 ARCHIVER_MODE[diff-exclude] ?= "file file ..." # Lists files and directories to exclude from diff. 162 ARCHIVER_MODE[dumpdata] = "1" # Uses environment data. 163 ARCHIVER_MODE[recipe] = "1" # Uses recipe and include files. 164 ARCHIVER_MODE[srpm] = "1" # Uses RPM package files. 165 166 For information on how the variable works, see the 167 ``meta/classes/archiver.bbclass`` file in the :term:`Source Directory`. 168 169 :term:`AS` 170 Minimal command and arguments needed to run the assembler. 171 172 :term:`ASSUME_PROVIDED` 173 Lists recipe names (:term:`PN` values) BitBake does not 174 attempt to build. Instead, BitBake assumes these recipes have already 175 been built. 176 177 In OpenEmbedded-Core, :term:`ASSUME_PROVIDED` mostly specifies native 178 tools that should not be built. An example is ``git-native``, which 179 when specified, allows for the Git binary from the host to be used 180 rather than building ``git-native``. 181 182 :term:`ASSUME_SHLIBS` 183 Provides additional ``shlibs`` provider mapping information, which 184 adds to or overwrites the information provided automatically by the 185 system. Separate multiple entries using spaces. 186 187 As an example, use the following form to add an ``shlib`` provider of 188 shlibname in packagename with the optional version:: 189 190 shlibname:packagename[_version] 191 192 Here is an example that adds a shared library named ``libEGL.so.1`` 193 as being provided by the ``libegl-implementation`` package:: 194 195 ASSUME_SHLIBS = "libEGL.so.1:libegl-implementation" 196 197 :term:`AUTHOR` 198 The email address used to contact the original author or authors in 199 order to send patches and forward bugs. 200 201 :term:`AUTO_LIBNAME_PKGS` 202 When the :ref:`debian <ref-classes-debian>` class is inherited, 203 which is the default behavior, :term:`AUTO_LIBNAME_PKGS` specifies which 204 packages should be checked for libraries and renamed according to 205 Debian library package naming. 206 207 The default value is "${PACKAGES}", which causes the debian class to 208 act on all packages that are explicitly generated by the recipe. 209 210 :term:`AUTOREV` 211 When :term:`SRCREV` is set to the value of this variable, it specifies to 212 use the latest source revision in the repository. Here is an example:: 213 214 SRCREV = "${AUTOREV}" 215 216 If you use the previous statement to retrieve the latest version of 217 software, you need to be sure :term:`PV` contains 218 ``${``\ :term:`SRCPV`\ ``}``. For example, suppose you 219 have a kernel recipe that inherits the 220 :ref:`kernel <ref-classes-kernel>` class and you use the previous 221 statement. In this example, ``${SRCPV}`` does not automatically get 222 into :term:`PV`. Consequently, you need to change :term:`PV` in your recipe 223 so that it does contain ``${SRCPV}``. 224 225 For more information see the 226 ":ref:`dev-manual/common-tasks:automatically incrementing a package version number`" 227 section in the Yocto Project Development Tasks Manual. 228 229 :term:`AUTO_SYSLINUXMENU` 230 Enables creating an automatic menu for the syslinux bootloader. You 231 must set this variable in your recipe. The 232 :ref:`syslinux <ref-classes-syslinux>` class checks this variable. 233 234 :term:`AVAILTUNES` 235 The list of defined CPU and Application Binary Interface (ABI) 236 tunings (i.e. "tunes") available for use by the OpenEmbedded build 237 system. 238 239 The list simply presents the tunes that are available. Not all tunes 240 may be compatible with a particular machine configuration, or with 241 each other in a 242 :ref:`Multilib <dev-manual/common-tasks:combining multiple versions of library files into one image>` 243 configuration. 244 245 To add a tune to the list, be sure to append it with spaces using the 246 "+=" BitBake operator. Do not simply replace the list by using the 247 "=" operator. See the 248 ":ref:`bitbake:bitbake-user-manual/bitbake-user-manual-metadata:basic syntax`" section in the BitBake 249 User Manual for more information. 250 251 :term:`AZ_SAS` 252 Azure Storage Shared Access Signature, when using the 253 :ref:`Azure Storage fetcher (az://) <bitbake:bitbake-user-manual/bitbake-user-manual-fetching:fetchers>` 254 This variable can be defined to be used by the fetcher to authenticate 255 and gain access to non-public artifacts. 256 :: 257 258 AZ_SAS = ""se=2021-01-01&sp=r&sv=2018-11-09&sr=c&skoid=<skoid>&sig=<signature>"" 259 260 For more information see Microsoft's Azure Storage documentation at 261 https://docs.microsoft.com/en-us/azure/storage/common/storage-sas-overview 262 263 :term:`B` 264 The directory within the :term:`Build Directory` in 265 which the OpenEmbedded build system places generated objects during a 266 recipe's build process. By default, this directory is the same as the 267 :term:`S` directory, which is defined as:: 268 269 S = "${WORKDIR}/${BP}" 270 271 You can separate the (:term:`S`) directory and the directory pointed to 272 by the :term:`B` variable. Most Autotools-based recipes support 273 separating these directories. The build system defaults to using 274 separate directories for ``gcc`` and some kernel recipes. 275 276 :term:`BAD_RECOMMENDATIONS` 277 Lists "recommended-only" packages to not install. Recommended-only 278 packages are packages installed only through the 279 :term:`RRECOMMENDS` variable. You can prevent any 280 of these "recommended" packages from being installed by listing them 281 with the :term:`BAD_RECOMMENDATIONS` variable:: 282 283 BAD_RECOMMENDATIONS = "package_name package_name package_name ..." 284 285 You can set this variable globally in your ``local.conf`` file or you 286 can attach it to a specific image recipe by using the recipe name 287 override:: 288 289 BAD_RECOMMENDATIONS:pn-target_image = "package_name" 290 291 It is important to realize that if you choose to not install packages 292 using this variable and some other packages are dependent on them 293 (i.e. listed in a recipe's :term:`RDEPENDS` 294 variable), the OpenEmbedded build system ignores your request and 295 will install the packages to avoid dependency errors. 296 297 This variable is supported only when using the IPK and RPM 298 packaging backends. DEB is not supported. 299 300 See the :term:`NO_RECOMMENDATIONS` and the 301 :term:`PACKAGE_EXCLUDE` variables for related 302 information. 303 304 :term:`BASE_LIB` 305 The library directory name for the CPU or Application Binary 306 Interface (ABI) tune. The :term:`BASE_LIB` applies only in the Multilib 307 context. See the ":ref:`dev-manual/common-tasks:combining multiple versions of library files into one image`" 308 section in the Yocto Project Development Tasks Manual for information 309 on Multilib. 310 311 The :term:`BASE_LIB` variable is defined in the machine include files in 312 the :term:`Source Directory`. If Multilib is not 313 being used, the value defaults to "lib". 314 315 :term:`BASE_WORKDIR` 316 Points to the base of the work directory for all recipes. The default 317 value is "${TMPDIR}/work". 318 319 :term:`BB_ALLOWED_NETWORKS` 320 Specifies a space-delimited list of hosts that the fetcher is allowed 321 to use to obtain the required source code. Following are 322 considerations surrounding this variable: 323 324 - This host list is only used if :term:`BB_NO_NETWORK` is either not set 325 or set to "0". 326 327 - There is limited support for wildcard matching against the beginning of 328 host names. For example, the following setting matches 329 ``git.gnu.org``, ``ftp.gnu.org``, and ``foo.git.gnu.org``. 330 :: 331 332 BB_ALLOWED_NETWORKS = "*.gnu.org" 333 334 .. note:: 335 336 The use of the "``*``" character only works at the beginning of 337 a host name and it must be isolated from the remainder of the 338 host name. You cannot use the wildcard character in any other 339 location of the name or combined with the front part of the 340 name. 341 342 For example, ``*.foo.bar`` is supported, while ``*aa.foo.bar`` 343 is not. 344 345 - Mirrors not in the host list are skipped and logged in debug. 346 347 - Attempts to access networks not in the host list cause a failure. 348 349 Using :term:`BB_ALLOWED_NETWORKS` in conjunction with 350 :term:`PREMIRRORS` is very useful. Adding the host 351 you want to use to :term:`PREMIRRORS` results in the source code being 352 fetched from an allowed location and avoids raising an error when a 353 host that is not allowed is in a :term:`SRC_URI` 354 statement. This is because the fetcher does not attempt to use the 355 host listed in :term:`SRC_URI` after a successful fetch from the 356 :term:`PREMIRRORS` occurs. 357 358 :term:`BB_DANGLINGAPPENDS_WARNONLY` 359 Defines how BitBake handles situations where an append file 360 (``.bbappend``) has no corresponding recipe file (``.bb``). This 361 condition often occurs when layers get out of sync (e.g. ``oe-core`` 362 bumps a recipe version and the old recipe no longer exists and the 363 other layer has not been updated to the new version of the recipe 364 yet). 365 366 The default fatal behavior is safest because it is the sane reaction 367 given something is out of sync. It is important to realize when your 368 changes are no longer being applied. 369 370 You can change the default behavior by setting this variable to "1", 371 "yes", or "true" in your ``local.conf`` file, which is located in the 372 :term:`Build Directory`: Here is an example:: 373 374 BB_DANGLINGAPPENDS_WARNONLY = "1" 375 376 :term:`BB_DISKMON_DIRS` 377 Monitors disk space and available inodes during the build and allows 378 you to control the build based on these parameters. 379 380 Disk space monitoring is disabled by default. To enable monitoring, 381 add the :term:`BB_DISKMON_DIRS` variable to your ``conf/local.conf`` file 382 found in the :term:`Build Directory`. Use the 383 following form: 384 385 .. code-block:: none 386 387 BB_DISKMON_DIRS = "action,dir,threshold [...]" 388 389 where: 390 391 action is: 392 ABORT: Immediately stop the build when 393 a threshold is broken. 394 STOPTASKS: Stop the build after the currently 395 executing tasks have finished when 396 a threshold is broken. 397 WARN: Issue a warning but continue the 398 build when a threshold is broken. 399 Subsequent warnings are issued as 400 defined by the BB_DISKMON_WARNINTERVAL 401 variable, which must be defined in 402 the conf/local.conf file. 403 404 dir is: 405 Any directory you choose. You can specify one or 406 more directories to monitor by separating the 407 groupings with a space. If two directories are 408 on the same device, only the first directory 409 is monitored. 410 411 threshold is: 412 Either the minimum available disk space, 413 the minimum number of free inodes, or 414 both. You must specify at least one. To 415 omit one or the other, simply omit the value. 416 Specify the threshold using G, M, K for Gbytes, 417 Mbytes, and Kbytes, respectively. If you do 418 not specify G, M, or K, Kbytes is assumed by 419 default. Do not use GB, MB, or KB. 420 421 Here are some examples:: 422 423 BB_DISKMON_DIRS = "ABORT,${TMPDIR},1G,100K WARN,${SSTATE_DIR},1G,100K" 424 BB_DISKMON_DIRS = "STOPTASKS,${TMPDIR},1G" 425 BB_DISKMON_DIRS = "ABORT,${TMPDIR},,100K" 426 427 The first example works only if you also provide the 428 :term:`BB_DISKMON_WARNINTERVAL` 429 variable in the ``conf/local.conf``. This example causes the build 430 system to immediately stop when either the disk space in 431 ``${TMPDIR}`` drops below 1 Gbyte or the available free inodes drops 432 below 100 Kbytes. Because two directories are provided with the 433 variable, the build system also issue a warning when the disk space 434 in the ``${SSTATE_DIR}`` directory drops below 1 Gbyte or the number 435 of free inodes drops below 100 Kbytes. Subsequent warnings are issued 436 during intervals as defined by the :term:`BB_DISKMON_WARNINTERVAL` 437 variable. 438 439 The second example stops the build after all currently executing 440 tasks complete when the minimum disk space in the ``${TMPDIR}`` 441 directory drops below 1 Gbyte. No disk monitoring occurs for the free 442 inodes in this case. 443 444 The final example immediately stops the build when the number of 445 free inodes in the ``${TMPDIR}`` directory drops below 100 Kbytes. No 446 disk space monitoring for the directory itself occurs in this case. 447 448 :term:`BB_DISKMON_WARNINTERVAL` 449 Defines the disk space and free inode warning intervals. To set these 450 intervals, define the variable in your ``conf/local.conf`` file in 451 the :term:`Build Directory`. 452 453 If you are going to use the :term:`BB_DISKMON_WARNINTERVAL` variable, you 454 must also use the :term:`BB_DISKMON_DIRS` 455 variable and define its action as "WARN". During the build, 456 subsequent warnings are issued each time disk space or number of free 457 inodes further reduces by the respective interval. 458 459 If you do not provide a :term:`BB_DISKMON_WARNINTERVAL` variable and you 460 do use :term:`BB_DISKMON_DIRS` with the "WARN" action, the disk 461 monitoring interval defaults to the following:: 462 463 BB_DISKMON_WARNINTERVAL = "50M,5K" 464 465 When specifying the variable in your configuration file, use the 466 following form: 467 468 .. code-block:: none 469 470 BB_DISKMON_WARNINTERVAL = "disk_space_interval,disk_inode_interval" 471 472 where: 473 474 disk_space_interval is: 475 An interval of memory expressed in either 476 G, M, or K for Gbytes, Mbytes, or Kbytes, 477 respectively. You cannot use GB, MB, or KB. 478 479 disk_inode_interval is: 480 An interval of free inodes expressed in either 481 G, M, or K for Gbytes, Mbytes, or Kbytes, 482 respectively. You cannot use GB, MB, or KB. 483 484 Here is an example:: 485 486 BB_DISKMON_DIRS = "WARN,${SSTATE_DIR},1G,100K" 487 BB_DISKMON_WARNINTERVAL = "50M,5K" 488 489 These variables cause the 490 OpenEmbedded build system to issue subsequent warnings each time the 491 available disk space further reduces by 50 Mbytes or the number of 492 free inodes further reduces by 5 Kbytes in the ``${SSTATE_DIR}`` 493 directory. Subsequent warnings based on the interval occur each time 494 a respective interval is reached beyond the initial warning (i.e. 1 495 Gbytes and 100 Kbytes). 496 497 :term:`BB_GENERATE_MIRROR_TARBALLS` 498 Causes tarballs of the source control repositories (e.g. Git 499 repositories), including metadata, to be placed in the 500 :term:`DL_DIR` directory. 501 502 For performance reasons, creating and placing tarballs of these 503 repositories is not the default action by the OpenEmbedded build 504 system. 505 :: 506 507 BB_GENERATE_MIRROR_TARBALLS = "1" 508 509 Set this variable in your 510 ``local.conf`` file in the :term:`Build Directory`. 511 512 Once you have the tarballs containing your source files, you can 513 clean up your :term:`DL_DIR` directory by deleting any Git or other 514 source control work directories. 515 516 :term:`BB_NUMBER_THREADS` 517 The maximum number of tasks BitBake should run in parallel at any one 518 time. The OpenEmbedded build system automatically configures this 519 variable to be equal to the number of cores on the build system. For 520 example, a system with a dual core processor that also uses 521 hyper-threading causes the :term:`BB_NUMBER_THREADS` variable to default 522 to "4". 523 524 For single socket systems (i.e. one CPU), you should not have to 525 override this variable to gain optimal parallelism during builds. 526 However, if you have very large systems that employ multiple physical 527 CPUs, you might want to make sure the :term:`BB_NUMBER_THREADS` variable 528 is not set higher than "20". 529 530 For more information on speeding up builds, see the 531 ":ref:`dev-manual/common-tasks:speeding up a build`" 532 section in the Yocto Project Development Tasks Manual. 533 534 :term:`BB_SERVER_TIMEOUT` 535 Specifies the time (in seconds) after which to unload the BitBake 536 server due to inactivity. Set :term:`BB_SERVER_TIMEOUT` to determine how 537 long the BitBake server stays resident between invocations. 538 539 For example, the following statement in your ``local.conf`` file 540 instructs the server to be unloaded after 20 seconds of inactivity:: 541 542 BB_SERVER_TIMEOUT = "20" 543 544 If you want the server to never be unloaded, 545 set :term:`BB_SERVER_TIMEOUT` to "-1". 546 547 :term:`BBCLASSEXTEND` 548 Allows you to extend a recipe so that it builds variants of the 549 software. There are common variants for recipes as "natives" like 550 ``quilt-native``, which is a copy of Quilt built to run on the build 551 system; "crosses" such as ``gcc-cross``, which is a compiler built to 552 run on the build machine but produces binaries that run on the target 553 :term:`MACHINE`; "nativesdk", which targets the SDK 554 machine instead of :term:`MACHINE`; and "mulitlibs" in the form 555 "``multilib:``\ multilib_name". 556 557 To build a different variant of the recipe with a minimal amount of 558 code, it usually is as simple as adding the following to your recipe:: 559 560 BBCLASSEXTEND =+ "native nativesdk" 561 BBCLASSEXTEND =+ "multilib:multilib_name" 562 563 .. note:: 564 565 Internally, the :term:`BBCLASSEXTEND` mechanism generates recipe 566 variants by rewriting variable values and applying overrides such 567 as ``:class-native``. For example, to generate a native version of 568 a recipe, a :term:`DEPENDS` on "foo" is rewritten 569 to a :term:`DEPENDS` on "foo-native". 570 571 Even when using :term:`BBCLASSEXTEND`, the recipe is only parsed once. 572 Parsing once adds some limitations. For example, it is not 573 possible to include a different file depending on the variant, 574 since ``include`` statements are processed when the recipe is 575 parsed. 576 577 :term:`BBFILE_COLLECTIONS` 578 Lists the names of configured layers. These names are used to find 579 the other ``BBFILE_*`` variables. Typically, each layer will append 580 its name to this variable in its ``conf/layer.conf`` file. 581 582 :term:`BBFILE_PATTERN` 583 Variable that expands to match files from 584 :term:`BBFILES` in a particular layer. This variable 585 is used in the ``conf/layer.conf`` file and must be suffixed with the 586 name of the specific layer (e.g. ``BBFILE_PATTERN_emenlow``). 587 588 :term:`BBFILE_PRIORITY` 589 Assigns the priority for recipe files in each layer. 590 591 This variable is useful in situations where the same recipe appears 592 in more than one layer. Setting this variable allows you to 593 prioritize a layer against other layers that contain the same recipe 594 - effectively letting you control the precedence for the multiple 595 layers. The precedence established through this variable stands 596 regardless of a recipe's version (:term:`PV` variable). For 597 example, a layer that has a recipe with a higher :term:`PV` value but for 598 which the :term:`BBFILE_PRIORITY` is set to have a lower precedence still 599 has a lower precedence. 600 601 A larger value for the :term:`BBFILE_PRIORITY` variable results in a 602 higher precedence. For example, the value 6 has a higher precedence 603 than the value 5. If not specified, the :term:`BBFILE_PRIORITY` variable 604 is set based on layer dependencies (see the :term:`LAYERDEPENDS` variable 605 for more information. The default priority, if unspecified for a 606 layer with no dependencies, is the lowest defined priority + 1 (or 1 607 if no priorities are defined). 608 609 .. tip:: 610 611 You can use the command ``bitbake-layers show-layers`` 612 to list all configured layers along with their priorities. 613 614 :term:`BBFILES` 615 A space-separated list of recipe files BitBake uses to build 616 software. 617 618 When specifying recipe files, you can pattern match using Python's 619 `glob <https://docs.python.org/3/library/glob.html>`_ syntax. 620 For details on the syntax, see the documentation by following the 621 previous link. 622 623 :term:`BBFILES_DYNAMIC` 624 Activates content when identified layers are present. You identify 625 the layers by the collections that the layers define. 626 627 Use the :term:`BBFILES_DYNAMIC` variable to avoid ``.bbappend`` files 628 whose corresponding ``.bb`` file is in a layer that attempts to 629 modify other layers through ``.bbappend`` but does not want to 630 introduce a hard dependency on those other layers. 631 632 Use the following form for :term:`BBFILES_DYNAMIC`: 633 ``collection_name:filename_pattern``. 634 635 The following example identifies two collection names and two 636 filename patterns:: 637 638 BBFILES_DYNAMIC += " \ 639 clang-layer:${LAYERDIR}/bbappends/meta-clang/*/*/*.bbappend \ 640 core:${LAYERDIR}/bbappends/openembedded-core/meta/*/*/*.bbappend \ 641 " 642 643 This next example shows an error message that occurs because invalid 644 entries are found, which cause parsing to fail: 645 646 .. code-block:: none 647 648 ERROR: BBFILES_DYNAMIC entries must be of the form <collection name>:<filename pattern>, not: 649 /work/my-layer/bbappends/meta-security-isafw/*/*/*.bbappend 650 /work/my-layer/bbappends/openembedded-core/meta/*/*/*.bbappend 651 652 :term:`BBINCLUDELOGS` 653 Variable that controls how BitBake displays logs on build failure. 654 655 :term:`BBINCLUDELOGS_LINES` 656 If :term:`BBINCLUDELOGS` is set, specifies the 657 maximum number of lines from the task log file to print when 658 reporting a failed task. If you do not set :term:`BBINCLUDELOGS_LINES`, 659 the entire log is printed. 660 661 :term:`BBLAYERS` 662 Lists the layers to enable during the build. This variable is defined 663 in the ``bblayers.conf`` configuration file in the :term:`Build Directory`. 664 Here is an example:: 665 666 BBLAYERS = " \ 667 /home/scottrif/poky/meta \ 668 /home/scottrif/poky/meta-poky \ 669 /home/scottrif/poky/meta-yocto-bsp \ 670 /home/scottrif/poky/meta-mykernel \ 671 " 672 673 This example enables four layers, one of which is a custom, 674 user-defined layer named ``meta-mykernel``. 675 676 :term:`BBMASK` 677 Prevents BitBake from processing recipes and recipe append files. 678 679 You can use the :term:`BBMASK` variable to "hide" these ``.bb`` and 680 ``.bbappend`` files. BitBake ignores any recipe or recipe append 681 files that match any of the expressions. It is as if BitBake does not 682 see them at all. Consequently, matching files are not parsed or 683 otherwise used by BitBake. 684 685 The values you provide are passed to Python's regular expression 686 compiler. Consequently, the syntax follows Python's Regular 687 Expression (re) syntax. The expressions are compared against the full 688 paths to the files. For complete syntax information, see Python's 689 documentation at https://docs.python.org/3/library/re.html#regular-expression-syntax. 690 691 The following example uses a complete regular expression to tell 692 BitBake to ignore all recipe and recipe append files in the 693 ``meta-ti/recipes-misc/`` directory:: 694 695 BBMASK = "meta-ti/recipes-misc/" 696 697 If you want to mask out multiple directories or recipes, you can 698 specify multiple regular expression fragments. This next example 699 masks out multiple directories and individual recipes:: 700 701 BBMASK += "/meta-ti/recipes-misc/ meta-ti/recipes-ti/packagegroup/" 702 BBMASK += "/meta-oe/recipes-support/" 703 BBMASK += "/meta-foo/.*/openldap" 704 BBMASK += "opencv.*\.bbappend" 705 BBMASK += "lzma" 706 707 .. note:: 708 709 When specifying a directory name, use the trailing slash character 710 to ensure you match just that directory name. 711 712 :term:`BBMULTICONFIG` 713 Specifies each additional separate configuration when you are 714 building targets with multiple configurations. Use this variable in 715 your ``conf/local.conf`` configuration file. Specify a 716 multiconfigname for each configuration file you are using. For 717 example, the following line specifies three configuration files:: 718 719 BBMULTICONFIG = "configA configB configC" 720 721 Each configuration file you 722 use must reside in the :term:`Build Directory` 723 ``conf/multiconfig`` directory (e.g. 724 ``build_directory/conf/multiconfig/configA.conf``). 725 726 For information on how to use :term:`BBMULTICONFIG` in an environment 727 that supports building targets with multiple configurations, see the 728 ":ref:`dev-manual/common-tasks:building images for multiple targets using multiple configurations`" 729 section in the Yocto Project Development Tasks Manual. 730 731 :term:`BBPATH` 732 Used by BitBake to locate ``.bbclass`` and configuration files. This 733 variable is analogous to the ``PATH`` variable. 734 735 .. note:: 736 737 If you run BitBake from a directory outside of the 738 :term:`Build Directory`, you must be sure to set :term:`BBPATH` 739 to point to the Build Directory. Set the variable as you would any 740 environment variable and then run BitBake:: 741 742 $ BBPATH = "build_directory" 743 $ export BBPATH 744 $ bitbake target 745 746 747 :term:`BBSERVER` 748 If defined in the BitBake environment, :term:`BBSERVER` points to the 749 BitBake remote server. 750 751 Use the following format to export the variable to the BitBake 752 environment:: 753 754 export BBSERVER=localhost:$port 755 756 By default, :term:`BBSERVER` also appears in :term:`BB_BASEHASH_IGNORE_VARS`. 757 Consequently, :term:`BBSERVER` is excluded from checksum and dependency 758 data. 759 760 :term:`BINCONFIG` 761 When inheriting the 762 :ref:`binconfig-disabled <ref-classes-binconfig-disabled>` class, 763 this variable specifies binary configuration scripts to disable in 764 favor of using ``pkg-config`` to query the information. The 765 :ref:`binconfig-disabled <ref-classes-binconfig-disabled>` class will modify the specified scripts to 766 return an error so that calls to them can be easily found and 767 replaced. 768 769 To add multiple scripts, separate them by spaces. Here is an example 770 from the ``libpng`` recipe:: 771 772 BINCONFIG = "${bindir}/libpng-config ${bindir}/libpng16-config" 773 774 :term:`BINCONFIG_GLOB` 775 When inheriting the :ref:`binconfig <ref-classes-binconfig>` class, 776 this variable specifies a wildcard for configuration scripts that 777 need editing. The scripts are edited to correct any paths that have 778 been set up during compilation so that they are correct for use when 779 installed into the sysroot and called by the build processes of other 780 recipes. 781 782 .. note:: 783 784 The :term:`BINCONFIG_GLOB` variable uses 785 `shell globbing <https://tldp.org/LDP/abs/html/globbingref.html>`__, 786 which is recognition and expansion of wildcards during pattern 787 matching. Shell globbing is very similar to 788 `fnmatch <https://docs.python.org/3/library/fnmatch.html#module-fnmatch>`__ 789 and `glob <https://docs.python.org/3/library/glob.html>`__. 790 791 For more information on how this variable works, see 792 ``meta/classes/binconfig.bbclass`` in the :term:`Source Directory`. 793 You can also find general 794 information on the class in the 795 ":ref:`ref-classes-binconfig`" section. 796 797 :term:`BP` 798 The base recipe name and version but without any special recipe name 799 suffix (i.e. ``-native``, ``lib64-``, and so forth). :term:`BP` is 800 comprised of the following:: 801 802 ${BPN}-${PV} 803 804 :term:`BPN` 805 This variable is a version of the :term:`PN` variable with 806 common prefixes and suffixes removed, such as ``nativesdk-``, 807 ``-cross``, ``-native``, and multilib's ``lib64-`` and ``lib32-``. 808 The exact lists of prefixes and suffixes removed are specified by the 809 :term:`MLPREFIX` and 810 :term:`SPECIAL_PKGSUFFIX` variables, 811 respectively. 812 813 :term:`BUGTRACKER` 814 Specifies a URL for an upstream bug tracking website for a recipe. 815 The OpenEmbedded build system does not use this variable. Rather, the 816 variable is a useful pointer in case a bug in the software being 817 built needs to be manually reported. 818 819 :term:`BUILD_ARCH` 820 Specifies the architecture of the build host (e.g. ``i686``). The 821 OpenEmbedded build system sets the value of :term:`BUILD_ARCH` from the 822 machine name reported by the ``uname`` command. 823 824 :term:`BUILD_AS_ARCH` 825 Specifies the architecture-specific assembler flags for the build 826 host. By default, the value of :term:`BUILD_AS_ARCH` is empty. 827 828 :term:`BUILD_CC_ARCH` 829 Specifies the architecture-specific C compiler flags for the build 830 host. By default, the value of :term:`BUILD_CC_ARCH` is empty. 831 832 :term:`BUILD_CCLD` 833 Specifies the linker command to be used for the build host when the C 834 compiler is being used as the linker. By default, :term:`BUILD_CCLD` 835 points to GCC and passes as arguments the value of 836 :term:`BUILD_CC_ARCH`, assuming 837 :term:`BUILD_CC_ARCH` is set. 838 839 :term:`BUILD_CFLAGS` 840 Specifies the flags to pass to the C compiler when building for the 841 build host. When building in the ``-native`` context, 842 :term:`CFLAGS` is set to the value of this variable by 843 default. 844 845 :term:`BUILD_CPPFLAGS` 846 Specifies the flags to pass to the C preprocessor (i.e. to both the C 847 and the C++ compilers) when building for the build host. When 848 building in the ``-native`` context, :term:`CPPFLAGS` 849 is set to the value of this variable by default. 850 851 :term:`BUILD_CXXFLAGS` 852 Specifies the flags to pass to the C++ compiler when building for the 853 build host. When building in the ``-native`` context, 854 :term:`CXXFLAGS` is set to the value of this variable 855 by default. 856 857 :term:`BUILD_FC` 858 Specifies the Fortran compiler command for the build host. By 859 default, :term:`BUILD_FC` points to Gfortran and passes as arguments the 860 value of :term:`BUILD_CC_ARCH`, assuming 861 :term:`BUILD_CC_ARCH` is set. 862 863 :term:`BUILD_LD` 864 Specifies the linker command for the build host. By default, 865 :term:`BUILD_LD` points to the GNU linker (ld) and passes as arguments 866 the value of :term:`BUILD_LD_ARCH`, assuming 867 :term:`BUILD_LD_ARCH` is set. 868 869 :term:`BUILD_LD_ARCH` 870 Specifies architecture-specific linker flags for the build host. By 871 default, the value of :term:`BUILD_LD_ARCH` is empty. 872 873 :term:`BUILD_LDFLAGS` 874 Specifies the flags to pass to the linker when building for the build 875 host. When building in the ``-native`` context, 876 :term:`LDFLAGS` is set to the value of this variable 877 by default. 878 879 :term:`BUILD_OPTIMIZATION` 880 Specifies the optimization flags passed to the C compiler when 881 building for the build host or the SDK. The flags are passed through 882 the :term:`BUILD_CFLAGS` and 883 :term:`BUILDSDK_CFLAGS` default values. 884 885 The default value of the :term:`BUILD_OPTIMIZATION` variable is "-O2 886 -pipe". 887 888 :term:`BUILD_OS` 889 Specifies the operating system in use on the build host (e.g. 890 "linux"). The OpenEmbedded build system sets the value of 891 :term:`BUILD_OS` from the OS reported by the ``uname`` command - the 892 first word, converted to lower-case characters. 893 894 :term:`BUILD_PREFIX` 895 The toolchain binary prefix used for native recipes. The OpenEmbedded 896 build system uses the :term:`BUILD_PREFIX` value to set the 897 :term:`TARGET_PREFIX` when building for 898 ``native`` recipes. 899 900 :term:`BUILD_STRIP` 901 Specifies the command to be used to strip debugging symbols from 902 binaries produced for the build host. By default, :term:`BUILD_STRIP` 903 points to 904 ``${``\ :term:`BUILD_PREFIX`\ ``}strip``. 905 906 :term:`BUILD_SYS` 907 Specifies the system, including the architecture and the operating 908 system, to use when building for the build host (i.e. when building 909 ``native`` recipes). 910 911 The OpenEmbedded build system automatically sets this variable based 912 on :term:`BUILD_ARCH`, 913 :term:`BUILD_VENDOR`, and 914 :term:`BUILD_OS`. You do not need to set the 915 :term:`BUILD_SYS` variable yourself. 916 917 :term:`BUILD_VENDOR` 918 Specifies the vendor name to use when building for the build host. 919 The default value is an empty string (""). 920 921 :term:`BUILDDIR` 922 Points to the location of the :term:`Build Directory`. 923 You can define this directory indirectly through the 924 :ref:`structure-core-script` script by passing in a Build 925 Directory path when you run the script. If you run the script and do 926 not provide a Build Directory path, the :term:`BUILDDIR` defaults to 927 ``build`` in the current directory. 928 929 :term:`BUILDHISTORY_COMMIT` 930 When inheriting the :ref:`buildhistory <ref-classes-buildhistory>` 931 class, this variable specifies whether or not to commit the build 932 history output in a local Git repository. If set to "1", this local 933 repository will be maintained automatically by the :ref:`buildhistory <ref-classes-buildhistory>` 934 class and a commit will be created on every build for changes to each 935 top-level subdirectory of the build history output (images, packages, 936 and sdk). If you want to track changes to build history over time, 937 you should set this value to "1". 938 939 By default, the :ref:`buildhistory <ref-classes-buildhistory>` class does not commit the build 940 history output in a local Git repository:: 941 942 BUILDHISTORY_COMMIT ?= "0" 943 944 :term:`BUILDHISTORY_COMMIT_AUTHOR` 945 When inheriting the :ref:`buildhistory <ref-classes-buildhistory>` 946 class, this variable specifies the author to use for each Git commit. 947 In order for the :term:`BUILDHISTORY_COMMIT_AUTHOR` variable to work, the 948 :term:`BUILDHISTORY_COMMIT` variable must 949 be set to "1". 950 951 Git requires that the value you provide for the 952 :term:`BUILDHISTORY_COMMIT_AUTHOR` variable takes the form of "name 953 email@host". Providing an email address or host that is not valid 954 does not produce an error. 955 956 By default, the :ref:`buildhistory <ref-classes-buildhistory>` class sets the variable as follows:: 957 958 BUILDHISTORY_COMMIT_AUTHOR ?= "buildhistory <buildhistory@${DISTRO}>" 959 960 :term:`BUILDHISTORY_DIR` 961 When inheriting the :ref:`buildhistory <ref-classes-buildhistory>` 962 class, this variable specifies the directory in which build history 963 information is kept. For more information on how the variable works, 964 see the :ref:`ref-classes-buildhistory` class. 965 966 By default, the :ref:`buildhistory <ref-classes-buildhistory>` class sets the directory as follows:: 967 968 BUILDHISTORY_DIR ?= "${TOPDIR}/buildhistory" 969 970 :term:`BUILDHISTORY_FEATURES` 971 When inheriting the :ref:`buildhistory <ref-classes-buildhistory>` 972 class, this variable specifies the build history features to be 973 enabled. For more information on how build history works, see the 974 ":ref:`dev-manual/common-tasks:maintaining build output quality`" 975 section in the Yocto Project Development Tasks Manual. 976 977 You can specify these features in the form of a space-separated list: 978 979 - *image:* Analysis of the contents of images, which includes the 980 list of installed packages among other things. 981 982 - *package:* Analysis of the contents of individual packages. 983 984 - *sdk:* Analysis of the contents of the software development kit 985 (SDK). 986 987 - *task:* Save output file signatures for 988 :ref:`shared state <overview-manual/concepts:shared state cache>` 989 (sstate) tasks. 990 This saves one file per task and lists the SHA-256 checksums for 991 each file staged (i.e. the output of the task). 992 993 By default, the :ref:`buildhistory <ref-classes-buildhistory>` class enables the following 994 features:: 995 996 BUILDHISTORY_FEATURES ?= "image package sdk" 997 998 :term:`BUILDHISTORY_IMAGE_FILES` 999 When inheriting the :ref:`buildhistory <ref-classes-buildhistory>` 1000 class, this variable specifies a list of paths to files copied from 1001 the image contents into the build history directory under an 1002 "image-files" directory in the directory for the image, so that you 1003 can track the contents of each file. The default is to copy 1004 ``/etc/passwd`` and ``/etc/group``, which allows you to monitor for 1005 changes in user and group entries. You can modify the list to include 1006 any file. Specifying an invalid path does not produce an error. 1007 Consequently, you can include files that might not always be present. 1008 1009 By default, the :ref:`buildhistory <ref-classes-buildhistory>` class provides paths to the 1010 following files:: 1011 1012 BUILDHISTORY_IMAGE_FILES ?= "/etc/passwd /etc/group" 1013 1014 :term:`BUILDHISTORY_PATH_PREFIX_STRIP` 1015 When inheriting the :ref:`buildhistory <ref-classes-buildhistory>` 1016 class, this variable specifies a common path prefix that should be 1017 stripped off the beginning of paths in the task signature list when the 1018 ``task`` feature is active in :term:`BUILDHISTORY_FEATURES`. This can be 1019 useful when build history is populated from multiple sources that may not 1020 all use the same top level directory. 1021 1022 By default, the :ref:`buildhistory <ref-classes-buildhistory>` class sets the variable as follows:: 1023 1024 BUILDHISTORY_PATH_PREFIX_STRIP ?= "" 1025 1026 In this case, no prefixes will be stripped. 1027 1028 :term:`BUILDHISTORY_PUSH_REPO` 1029 When inheriting the :ref:`buildhistory <ref-classes-buildhistory>` 1030 class, this variable optionally specifies a remote repository to 1031 which build history pushes Git changes. In order for 1032 :term:`BUILDHISTORY_PUSH_REPO` to work, 1033 :term:`BUILDHISTORY_COMMIT` must be set to 1034 "1". 1035 1036 The repository should correspond to a remote address that specifies a 1037 repository as understood by Git, or alternatively to a remote name 1038 that you have set up manually using ``git remote`` within the local 1039 repository. 1040 1041 By default, the :ref:`buildhistory <ref-classes-buildhistory>` class sets the variable as follows:: 1042 1043 BUILDHISTORY_PUSH_REPO ?= "" 1044 1045 :term:`BUILDSDK_CFLAGS` 1046 Specifies the flags to pass to the C compiler when building for the 1047 SDK. When building in the ``nativesdk-`` context, 1048 :term:`CFLAGS` is set to the value of this variable by 1049 default. 1050 1051 :term:`BUILDSDK_CPPFLAGS` 1052 Specifies the flags to pass to the C pre-processor (i.e. to both the 1053 C and the C++ compilers) when building for the SDK. When building in 1054 the ``nativesdk-`` context, :term:`CPPFLAGS` is set 1055 to the value of this variable by default. 1056 1057 :term:`BUILDSDK_CXXFLAGS` 1058 Specifies the flags to pass to the C++ compiler when building for the 1059 SDK. When building in the ``nativesdk-`` context, 1060 :term:`CXXFLAGS` is set to the value of this variable 1061 by default. 1062 1063 :term:`BUILDSDK_LDFLAGS` 1064 Specifies the flags to pass to the linker when building for the SDK. 1065 When building in the ``nativesdk-`` context, 1066 :term:`LDFLAGS` is set to the value of this variable 1067 by default. 1068 1069 :term:`BUILDSTATS_BASE` 1070 Points to the location of the directory that holds build statistics 1071 when you use and enable the 1072 :ref:`buildstats <ref-classes-buildstats>` class. The 1073 :term:`BUILDSTATS_BASE` directory defaults to 1074 ``${``\ :term:`TMPDIR`\ ``}/buildstats/``. 1075 1076 :term:`BUSYBOX_SPLIT_SUID` 1077 For the BusyBox recipe, specifies whether to split the output 1078 executable file into two parts: one for features that require 1079 ``setuid root``, and one for the remaining features (i.e. those that 1080 do not require ``setuid root``). 1081 1082 The :term:`BUSYBOX_SPLIT_SUID` variable defaults to "1", which results in 1083 splitting the output executable file. Set the variable to "0" to get 1084 a single output executable file. 1085 1086 :term:`CACHE` 1087 Specifies the directory BitBake uses to store a cache of the 1088 :term:`Metadata` so it does not need to be parsed every time 1089 BitBake is started. 1090 1091 :term:`CC` 1092 The minimal command and arguments used to run the C compiler. 1093 1094 :term:`CFLAGS` 1095 Specifies the flags to pass to the C compiler. This variable is 1096 exported to an environment variable and thus made visible to the 1097 software being built during the compilation step. 1098 1099 Default initialization for :term:`CFLAGS` varies depending on what is 1100 being built: 1101 1102 - :term:`TARGET_CFLAGS` when building for the 1103 target 1104 1105 - :term:`BUILD_CFLAGS` when building for the 1106 build host (i.e. ``-native``) 1107 1108 - :term:`BUILDSDK_CFLAGS` when building for 1109 an SDK (i.e. ``nativesdk-``) 1110 1111 :term:`CLASSOVERRIDE` 1112 An internal variable specifying the special class override that 1113 should currently apply (e.g. "class-target", "class-native", and so 1114 forth). The classes that use this variable (e.g. 1115 :ref:`native <ref-classes-native>`, 1116 :ref:`nativesdk <ref-classes-nativesdk>`, and so forth) set the 1117 variable to appropriate values. 1118 1119 .. note:: 1120 1121 :term:`CLASSOVERRIDE` gets its default "class-target" value from the 1122 ``bitbake.conf`` file. 1123 1124 As an example, the following override allows you to install extra 1125 files, but only when building for the target:: 1126 1127 do_install:append:class-target() { 1128 install my-extra-file ${D}${sysconfdir} 1129 } 1130 1131 Here is an example where ``FOO`` is set to 1132 "native" when building for the build host, and to "other" when not 1133 building for the build host:: 1134 1135 FOO:class-native = "native" 1136 FOO = "other" 1137 1138 The underlying mechanism behind :term:`CLASSOVERRIDE` is simply 1139 that it is included in the default value of 1140 :term:`OVERRIDES`. 1141 1142 :term:`CLEANBROKEN` 1143 If set to "1" within a recipe, :term:`CLEANBROKEN` specifies that the 1144 ``make clean`` command does not work for the software being built. 1145 Consequently, the OpenEmbedded build system will not try to run 1146 ``make clean`` during the :ref:`ref-tasks-configure` 1147 task, which is the default behavior. 1148 1149 :term:`COMBINED_FEATURES` 1150 Provides a list of hardware features that are enabled in both 1151 :term:`MACHINE_FEATURES` and 1152 :term:`DISTRO_FEATURES`. This select list of 1153 features contains features that make sense to be controlled both at 1154 the machine and distribution configuration level. For example, the 1155 "bluetooth" feature requires hardware support but should also be 1156 optional at the distribution level, in case the hardware supports 1157 Bluetooth but you do not ever intend to use it. 1158 1159 :term:`COMMON_LICENSE_DIR` 1160 Points to ``meta/files/common-licenses`` in the 1161 :term:`Source Directory`, which is where generic license 1162 files reside. 1163 1164 :term:`COMPATIBLE_HOST` 1165 A regular expression that resolves to one or more hosts (when the 1166 recipe is native) or one or more targets (when the recipe is 1167 non-native) with which a recipe is compatible. The regular expression 1168 is matched against :term:`HOST_SYS`. You can use the 1169 variable to stop recipes from being built for classes of systems with 1170 which the recipes are not compatible. Stopping these builds is 1171 particularly useful with kernels. The variable also helps to increase 1172 parsing speed since the build system skips parsing recipes not 1173 compatible with the current system. 1174 1175 :term:`COMPATIBLE_MACHINE` 1176 A regular expression that resolves to one or more target machines 1177 with which a recipe is compatible. The regular expression is matched 1178 against :term:`MACHINEOVERRIDES`. You can use 1179 the variable to stop recipes from being built for machines with which 1180 the recipes are not compatible. Stopping these builds is particularly 1181 useful with kernels. The variable also helps to increase parsing 1182 speed since the build system skips parsing recipes not compatible 1183 with the current machine. 1184 1185 :term:`COMPLEMENTARY_GLOB` 1186 Defines wildcards to match when installing a list of complementary 1187 packages for all the packages explicitly (or implicitly) installed in 1188 an image. 1189 1190 .. note:: 1191 1192 The :term:`COMPLEMENTARY_GLOB` variable uses Unix filename pattern matching 1193 (`fnmatch <https://docs.python.org/3/library/fnmatch.html#module-fnmatch>`__), 1194 which is similar to the Unix style pathname pattern expansion 1195 (`glob <https://docs.python.org/3/library/glob.html>`__). 1196 1197 The resulting list of complementary packages is associated with an 1198 item that can be added to 1199 :term:`IMAGE_FEATURES`. An example usage of 1200 this is the "dev-pkgs" item that when added to :term:`IMAGE_FEATURES` 1201 will install -dev packages (containing headers and other development 1202 files) for every package in the image. 1203 1204 To add a new feature item pointing to a wildcard, use a variable flag 1205 to specify the feature item name and use the value to specify the 1206 wildcard. Here is an example:: 1207 1208 COMPLEMENTARY_GLOB[dev-pkgs] = '*-dev' 1209 1210 :term:`COMPONENTS_DIR` 1211 Stores sysroot components for each recipe. The OpenEmbedded build 1212 system uses :term:`COMPONENTS_DIR` when constructing recipe-specific 1213 sysroots for other recipes. 1214 1215 The default is 1216 "``${``\ :term:`STAGING_DIR`\ ``}-components``." 1217 (i.e. 1218 "``${``\ :term:`TMPDIR`\ ``}/sysroots-components``"). 1219 1220 :term:`CONF_VERSION` 1221 Tracks the version of the local configuration file (i.e. 1222 ``local.conf``). The value for :term:`CONF_VERSION` increments each time 1223 ``build/conf/`` compatibility changes. 1224 1225 :term:`CONFFILES` 1226 Identifies editable or configurable files that are part of a package. 1227 If the Package Management System (PMS) is being used to update 1228 packages on the target system, it is possible that configuration 1229 files you have changed after the original installation and that you 1230 now want to remain unchanged are overwritten. In other words, 1231 editable files might exist in the package that you do not want reset 1232 as part of the package update process. You can use the :term:`CONFFILES` 1233 variable to list the files in the package that you wish to prevent 1234 the PMS from overwriting during this update process. 1235 1236 To use the :term:`CONFFILES` variable, provide a package name override 1237 that identifies the resulting package. Then, provide a 1238 space-separated list of files. Here is an example:: 1239 1240 CONFFILES:${PN} += "${sysconfdir}/file1 \ 1241 ${sysconfdir}/file2 ${sysconfdir}/file3" 1242 1243 There is a relationship between the :term:`CONFFILES` and :term:`FILES` 1244 variables. The files listed within :term:`CONFFILES` must be a subset of 1245 the files listed within :term:`FILES`. Because the configuration files 1246 you provide with :term:`CONFFILES` are simply being identified so that 1247 the PMS will not overwrite them, it makes sense that the files must 1248 already be included as part of the package through the :term:`FILES` 1249 variable. 1250 1251 .. note:: 1252 1253 When specifying paths as part of the :term:`CONFFILES` variable, it is 1254 good practice to use appropriate path variables. 1255 For example, ``${sysconfdir}`` rather than ``/etc`` or ``${bindir}`` 1256 rather than ``/usr/bin``. You can find a list of these variables at 1257 the top of the ``meta/conf/bitbake.conf`` file in the 1258 :term:`Source Directory`. 1259 1260 :term:`CONFIG_INITRAMFS_SOURCE` 1261 Identifies the initial RAM filesystem (initramfs) source files. The 1262 OpenEmbedded build system receives and uses this kernel Kconfig 1263 variable as an environment variable. By default, the variable is set 1264 to null (""). 1265 1266 The :term:`CONFIG_INITRAMFS_SOURCE` can be either a single cpio archive 1267 with a ``.cpio`` suffix or a space-separated list of directories and 1268 files for building the initramfs image. A cpio archive should contain 1269 a filesystem archive to be used as an initramfs image. Directories 1270 should contain a filesystem layout to be included in the initramfs 1271 image. Files should contain entries according to the format described 1272 by the ``usr/gen_init_cpio`` program in the kernel tree. 1273 1274 If you specify multiple directories and files, the initramfs image 1275 will be the aggregate of all of them. 1276 1277 For information on creating an initramfs, see the 1278 ":ref:`dev-manual/common-tasks:building an initial ram filesystem (initramfs) image`" section 1279 in the Yocto Project Development Tasks Manual. 1280 1281 :term:`CONFIG_SITE` 1282 A list of files that contains ``autoconf`` test results relevant to 1283 the current build. This variable is used by the Autotools utilities 1284 when running ``configure``. 1285 1286 :term:`CONFIGURE_FLAGS` 1287 The minimal arguments for GNU configure. 1288 1289 :term:`CONFLICT_DISTRO_FEATURES` 1290 When inheriting the 1291 :ref:`features_check <ref-classes-features_check>` 1292 class, this variable identifies distribution features that would be 1293 in conflict should the recipe be built. In other words, if the 1294 :term:`CONFLICT_DISTRO_FEATURES` variable lists a feature that also 1295 appears in :term:`DISTRO_FEATURES` within the current configuration, then 1296 the recipe will be skipped, and if the build system attempts to build 1297 the recipe then an error will be triggered. 1298 1299 :term:`COPY_LIC_DIRS` 1300 If set to "1" along with the 1301 :term:`COPY_LIC_MANIFEST` variable, the 1302 OpenEmbedded build system copies into the image the license files, 1303 which are located in ``/usr/share/common-licenses``, for each 1304 package. The license files are placed in directories within the image 1305 itself during build time. 1306 1307 .. note:: 1308 1309 The :term:`COPY_LIC_DIRS` does not offer a path for adding licenses for 1310 newly installed packages to an image, which might be most suitable for 1311 read-only filesystems that cannot be upgraded. See the 1312 :term:`LICENSE_CREATE_PACKAGE` variable for additional information. 1313 You can also reference the ":ref:`dev-manual/common-tasks:providing license text`" 1314 section in the Yocto Project Development Tasks Manual for 1315 information on providing license text. 1316 1317 :term:`COPY_LIC_MANIFEST` 1318 If set to "1", the OpenEmbedded build system copies the license 1319 manifest for the image to 1320 ``/usr/share/common-licenses/license.manifest`` within the image 1321 itself during build time. 1322 1323 .. note:: 1324 1325 The :term:`COPY_LIC_MANIFEST` does not offer a path for adding licenses for 1326 newly installed packages to an image, which might be most suitable for 1327 read-only filesystems that cannot be upgraded. See the 1328 :term:`LICENSE_CREATE_PACKAGE` variable for additional information. 1329 You can also reference the ":ref:`dev-manual/common-tasks:providing license text`" 1330 section in the Yocto Project Development Tasks Manual for 1331 information on providing license text. 1332 1333 :term:`COPYLEFT_LICENSE_EXCLUDE` 1334 A space-separated list of licenses to exclude from the source 1335 archived by the :ref:`archiver <ref-classes-archiver>` class. In 1336 other words, if a license in a recipe's 1337 :term:`LICENSE` value is in the value of 1338 :term:`COPYLEFT_LICENSE_EXCLUDE`, then its source is not archived by the 1339 class. 1340 1341 .. note:: 1342 1343 The :term:`COPYLEFT_LICENSE_EXCLUDE` variable takes precedence over the 1344 :term:`COPYLEFT_LICENSE_INCLUDE` variable. 1345 1346 The default value, which is "CLOSED Proprietary", for 1347 :term:`COPYLEFT_LICENSE_EXCLUDE` is set by the 1348 :ref:`copyleft_filter <ref-classes-copyleft_filter>` class, which 1349 is inherited by the :ref:`archiver <ref-classes-archiver>` class. 1350 1351 :term:`COPYLEFT_LICENSE_INCLUDE` 1352 A space-separated list of licenses to include in the source archived 1353 by the :ref:`archiver <ref-classes-archiver>` class. In other 1354 words, if a license in a recipe's :term:`LICENSE` 1355 value is in the value of :term:`COPYLEFT_LICENSE_INCLUDE`, then its 1356 source is archived by the class. 1357 1358 The default value is set by the 1359 :ref:`copyleft_filter <ref-classes-copyleft_filter>` class, which 1360 is inherited by the :ref:`archiver <ref-classes-archiver>` class. The default value includes 1361 "GPL*", "LGPL*", and "AGPL*". 1362 1363 :term:`COPYLEFT_PN_EXCLUDE` 1364 A list of recipes to exclude in the source archived by the 1365 :ref:`archiver <ref-classes-archiver>` class. The 1366 :term:`COPYLEFT_PN_EXCLUDE` variable overrides the license inclusion and 1367 exclusion caused through the 1368 :term:`COPYLEFT_LICENSE_INCLUDE` and 1369 :term:`COPYLEFT_LICENSE_EXCLUDE` 1370 variables, respectively. 1371 1372 The default value, which is "" indicating to not explicitly exclude 1373 any recipes by name, for :term:`COPYLEFT_PN_EXCLUDE` is set by the 1374 :ref:`copyleft_filter <ref-classes-copyleft_filter>` class, which 1375 is inherited by the :ref:`archiver <ref-classes-archiver>` class. 1376 1377 :term:`COPYLEFT_PN_INCLUDE` 1378 A list of recipes to include in the source archived by the 1379 :ref:`archiver <ref-classes-archiver>` class. The 1380 :term:`COPYLEFT_PN_INCLUDE` variable overrides the license inclusion and 1381 exclusion caused through the 1382 :term:`COPYLEFT_LICENSE_INCLUDE` and 1383 :term:`COPYLEFT_LICENSE_EXCLUDE` 1384 variables, respectively. 1385 1386 The default value, which is "" indicating to not explicitly include 1387 any recipes by name, for :term:`COPYLEFT_PN_INCLUDE` is set by the 1388 :ref:`copyleft_filter <ref-classes-copyleft_filter>` class, which 1389 is inherited by the :ref:`archiver <ref-classes-archiver>` class. 1390 1391 :term:`COPYLEFT_RECIPE_TYPES` 1392 A space-separated list of recipe types to include in the source 1393 archived by the :ref:`archiver <ref-classes-archiver>` class. 1394 Recipe types are ``target``, ``native``, ``nativesdk``, ``cross``, 1395 ``crosssdk``, and ``cross-canadian``. 1396 1397 The default value, which is "target*", for :term:`COPYLEFT_RECIPE_TYPES` 1398 is set by the :ref:`copyleft_filter <ref-classes-copyleft_filter>` 1399 class, which is inherited by the :ref:`archiver <ref-classes-archiver>` class. 1400 1401 :term:`CORE_IMAGE_EXTRA_INSTALL` 1402 Specifies the list of packages to be added to the image. You should 1403 only set this variable in the ``local.conf`` configuration file found 1404 in the :term:`Build Directory`. 1405 1406 This variable replaces ``POKY_EXTRA_INSTALL``, which is no longer 1407 supported. 1408 1409 :term:`COREBASE` 1410 Specifies the parent directory of the OpenEmbedded-Core Metadata 1411 layer (i.e. ``meta``). 1412 1413 It is an important distinction that :term:`COREBASE` points to the parent 1414 of this layer and not the layer itself. Consider an example where you 1415 have cloned the Poky Git repository and retained the ``poky`` name 1416 for your local copy of the repository. In this case, :term:`COREBASE` 1417 points to the ``poky`` folder because it is the parent directory of 1418 the ``poky/meta`` layer. 1419 1420 :term:`COREBASE_FILES` 1421 Lists files from the :term:`COREBASE` directory that 1422 should be copied other than the layers listed in the 1423 ``bblayers.conf`` file. The :term:`COREBASE_FILES` variable allows 1424 to copy metadata from the OpenEmbedded build system 1425 into the extensible SDK. 1426 1427 Explicitly listing files in :term:`COREBASE` is needed because it 1428 typically contains build directories and other files that should not 1429 normally be copied into the extensible SDK. Consequently, the value 1430 of :term:`COREBASE_FILES` is used in order to only copy the files that 1431 are actually needed. 1432 1433 :term:`CPP` 1434 The minimal command and arguments used to run the C preprocessor. 1435 1436 :term:`CPPFLAGS` 1437 Specifies the flags to pass to the C pre-processor (i.e. to both the 1438 C and the C++ compilers). This variable is exported to an environment 1439 variable and thus made visible to the software being built during the 1440 compilation step. 1441 1442 Default initialization for :term:`CPPFLAGS` varies depending on what is 1443 being built: 1444 1445 - :term:`TARGET_CPPFLAGS` when building for 1446 the target 1447 1448 - :term:`BUILD_CPPFLAGS` when building for the 1449 build host (i.e. ``-native``) 1450 1451 - :term:`BUILDSDK_CPPFLAGS` when building 1452 for an SDK (i.e. ``nativesdk-``) 1453 1454 :term:`CROSS_COMPILE` 1455 The toolchain binary prefix for the target tools. The 1456 :term:`CROSS_COMPILE` variable is the same as the 1457 :term:`TARGET_PREFIX` variable. 1458 1459 .. note:: 1460 1461 The OpenEmbedded build system sets the :term:`CROSS_COMPILE` 1462 variable only in certain contexts (e.g. when building for kernel 1463 and kernel module recipes). 1464 1465 :term:`CVE_CHECK_IGNORE` 1466 The list of CVE IDs which are ignored. Here is 1467 an example from the :oe_layerindex:`Python3 recipe</layerindex/recipe/23823>`:: 1468 1469 # This is windows only issue. 1470 CVE_CHECK_IGNORE += "CVE-2020-15523" 1471 1472 :term:`CVE_CHECK_SKIP_RECIPE` 1473 The list of package names (:term:`PN`) for which 1474 CVEs (Common Vulnerabilities and Exposures) are ignored. 1475 1476 :term:`CVE_PRODUCT` 1477 In a recipe, defines the name used to match the recipe name 1478 against the name in the upstream `NIST CVE database <https://nvd.nist.gov/>`__. 1479 1480 The default is ${:term:`BPN`}. If it does not match the name in the NIST CVE 1481 database or matches with multiple entries in the database, the default 1482 value needs to be changed. 1483 1484 Here is an example from the :oe_layerindex:`Berkeley DB recipe </layerindex/recipe/544>`:: 1485 1486 CVE_PRODUCT = "oracle_berkeley_db berkeley_db" 1487 1488 Sometimes the product name is not specific enough, for example 1489 "tar" has been matching CVEs for the GNU ``tar`` package and also 1490 the ``node-tar`` node.js extension. To avoid this problem, use the 1491 vendor name as a prefix. The syntax for this is:: 1492 1493 CVE_PRODUCT = "vendor:package" 1494 1495 :term:`CVSDIR` 1496 The directory in which files checked out under the CVS system are 1497 stored. 1498 1499 :term:`CXX` 1500 The minimal command and arguments used to run the C++ compiler. 1501 1502 :term:`CXXFLAGS` 1503 Specifies the flags to pass to the C++ compiler. This variable is 1504 exported to an environment variable and thus made visible to the 1505 software being built during the compilation step. 1506 1507 Default initialization for :term:`CXXFLAGS` varies depending on what is 1508 being built: 1509 1510 - :term:`TARGET_CXXFLAGS` when building for 1511 the target 1512 1513 - :term:`BUILD_CXXFLAGS` when building for the 1514 build host (i.e. ``-native``) 1515 1516 - :term:`BUILDSDK_CXXFLAGS` when building 1517 for an SDK (i.e. ``nativesdk-``) 1518 1519 :term:`D` 1520 The destination directory. The location in the :term:`Build Directory` 1521 where components are installed by the 1522 :ref:`ref-tasks-install` task. This location defaults 1523 to:: 1524 1525 ${WORKDIR}/image 1526 1527 .. note:: 1528 1529 Tasks that read from or write to this directory should run under 1530 :ref:`fakeroot <overview-manual/concepts:fakeroot and pseudo>`. 1531 1532 :term:`DATE` 1533 The date the build was started. Dates appear using the year, month, 1534 and day (YMD) format (e.g. "20150209" for February 9th, 2015). 1535 1536 :term:`DATETIME` 1537 The date and time on which the current build started. The format is 1538 suitable for timestamps. 1539 1540 :term:`DEBIAN_NOAUTONAME` 1541 When the :ref:`debian <ref-classes-debian>` class is inherited, 1542 which is the default behavior, :term:`DEBIAN_NOAUTONAME` specifies a 1543 particular package should not be renamed according to Debian library 1544 package naming. You must use the package name as an override when you 1545 set this variable. Here is an example from the ``fontconfig`` recipe:: 1546 1547 DEBIAN_NOAUTONAME:fontconfig-utils = "1" 1548 1549 :term:`DEBIANNAME` 1550 When the :ref:`debian <ref-classes-debian>` class is inherited, 1551 which is the default behavior, :term:`DEBIANNAME` allows you to override 1552 the library name for an individual package. Overriding the library 1553 name in these cases is rare. You must use the package name as an 1554 override when you set this variable. Here is an example from the 1555 ``dbus`` recipe:: 1556 1557 DEBIANNAME:${PN} = "dbus-1" 1558 1559 :term:`DEBUG_BUILD` 1560 Specifies to build packages with debugging information. This 1561 influences the value of the :term:`SELECTED_OPTIMIZATION` variable. 1562 1563 :term:`DEBUG_OPTIMIZATION` 1564 The options to pass in :term:`TARGET_CFLAGS` and :term:`CFLAGS` when 1565 compiling a system for debugging. This variable defaults to "-O 1566 -fno-omit-frame-pointer ${DEBUG_FLAGS} -pipe". 1567 1568 :term:`DEBUG_PREFIX_MAP` 1569 Allows to set C compiler options, such as ``-fdebug-prefix-map``, 1570 ``-fmacro-prefix-map``, and ``-ffile-prefix-map``, which allow to 1571 replace build-time paths by install-time ones in the debugging sections 1572 of binaries. This makes compiler output files location independent, 1573 at the cost of having to pass an extra command to tell the debugger 1574 where source files are. 1575 1576 This is used by the Yocto Project to guarantee 1577 :doc:`/test-manual/reproducible-builds` even when the source code of 1578 a package uses the ``__FILE__`` or ``assert()`` macros. See the 1579 `reproducible-builds.org <https://reproducible-builds.org/docs/build-path/>`__ 1580 website for details. 1581 1582 This variable is set in the ``meta/conf/bitbake.conf`` file. It is 1583 not intended to be user-configurable. 1584 1585 :term:`DEFAULT_PREFERENCE` 1586 Specifies a weak bias for recipe selection priority. 1587 1588 The most common usage of this is variable is to set it to "-1" within 1589 a recipe for a development version of a piece of software. Using the 1590 variable in this way causes the stable version of the recipe to build 1591 by default in the absence of :term:`PREFERRED_VERSION` being used to 1592 build the development version. 1593 1594 .. note:: 1595 1596 The bias provided by :term:`DEFAULT_PREFERENCE` is weak and is overridden 1597 by :term:`BBFILE_PRIORITY` if that variable is different between two 1598 layers that contain different versions of the same recipe. 1599 1600 :term:`DEFAULTTUNE` 1601 The default CPU and Application Binary Interface (ABI) tunings (i.e. 1602 the "tune") used by the OpenEmbedded build system. The 1603 :term:`DEFAULTTUNE` helps define 1604 :term:`TUNE_FEATURES`. 1605 1606 The default tune is either implicitly or explicitly set by the 1607 machine (:term:`MACHINE`). However, you can override 1608 the setting using available tunes as defined with 1609 :term:`AVAILTUNES`. 1610 1611 :term:`DEPENDS` 1612 Lists a recipe's build-time dependencies. These are dependencies on 1613 other recipes whose contents (e.g. headers and shared libraries) are 1614 needed by the recipe at build time. 1615 1616 As an example, consider a recipe ``foo`` that contains the following 1617 assignment:: 1618 1619 DEPENDS = "bar" 1620 1621 The practical effect of the previous 1622 assignment is that all files installed by bar will be available in 1623 the appropriate staging sysroot, given by the 1624 :term:`STAGING_DIR* <STAGING_DIR>` variables, by the time the 1625 :ref:`ref-tasks-configure` task for ``foo`` runs. 1626 This mechanism is implemented by having ``do_configure`` depend on 1627 the :ref:`ref-tasks-populate_sysroot` task of 1628 each recipe listed in :term:`DEPENDS`, through a 1629 ``[``\ :ref:`deptask <bitbake:bitbake-user-manual/bitbake-user-manual-metadata:variable flags>`\ ``]`` 1630 declaration in the :ref:`base <ref-classes-base>` class. 1631 1632 .. note:: 1633 1634 It seldom is necessary to reference, for example, :term:`STAGING_DIR_HOST` 1635 explicitly. The standard classes and build-related variables are 1636 configured to automatically use the appropriate staging sysroots. 1637 1638 As another example, :term:`DEPENDS` can also be used to add utilities 1639 that run on the build machine during the build. For example, a recipe 1640 that makes use of a code generator built by the recipe ``codegen`` 1641 might have the following:: 1642 1643 DEPENDS = "codegen-native" 1644 1645 For more 1646 information, see the :ref:`native <ref-classes-native>` class and 1647 the :term:`EXTRANATIVEPATH` variable. 1648 1649 .. note:: 1650 1651 - :term:`DEPENDS` is a list of recipe names. Or, to be more precise, 1652 it is a list of :term:`PROVIDES` names, which 1653 usually match recipe names. Putting a package name such as 1654 "foo-dev" in :term:`DEPENDS` does not make sense. Use "foo" 1655 instead, as this will put files from all the packages that make 1656 up ``foo``, which includes those from ``foo-dev``, into the 1657 sysroot. 1658 1659 - One recipe having another recipe in :term:`DEPENDS` does not by 1660 itself add any runtime dependencies between the packages 1661 produced by the two recipes. However, as explained in the 1662 ":ref:`overview-manual/concepts:automatically added runtime dependencies`" 1663 section in the Yocto Project Overview and Concepts Manual, 1664 runtime dependencies will often be added automatically, meaning 1665 :term:`DEPENDS` alone is sufficient for most recipes. 1666 1667 - Counterintuitively, :term:`DEPENDS` is often necessary even for 1668 recipes that install precompiled components. For example, if 1669 ``libfoo`` is a precompiled library that links against 1670 ``libbar``, then linking against ``libfoo`` requires both 1671 ``libfoo`` and ``libbar`` to be available in the sysroot. 1672 Without a :term:`DEPENDS` from the recipe that installs ``libfoo`` 1673 to the recipe that installs ``libbar``, other recipes might 1674 fail to link against ``libfoo``. 1675 1676 For information on runtime dependencies, see the 1677 :term:`RDEPENDS` variable. You can also see the 1678 ":ref:`bitbake:bitbake-user-manual/bitbake-user-manual-metadata:tasks`" and 1679 ":ref:`bitbake:bitbake-user-manual/bitbake-user-manual-execution:dependencies`" sections in the 1680 BitBake User Manual for additional information on tasks and 1681 dependencies. 1682 1683 :term:`DEPLOY_DIR` 1684 Points to the general area that the OpenEmbedded build system uses to 1685 place images, packages, SDKs, and other output files that are ready 1686 to be used outside of the build system. By default, this directory 1687 resides within the :term:`Build Directory` as 1688 ``${TMPDIR}/deploy``. 1689 1690 For more information on the structure of the Build Directory, see 1691 ":ref:`ref-manual/structure:the build directory - \`\`build/\`\``" section. 1692 For more detail on the contents of the ``deploy`` directory, see the 1693 ":ref:`overview-manual/concepts:images`", 1694 ":ref:`overview-manual/concepts:package feeds`", and 1695 ":ref:`overview-manual/concepts:application development sdk`" sections all in the 1696 Yocto Project Overview and Concepts Manual. 1697 1698 :term:`DEPLOY_DIR_DEB` 1699 Points to the area that the OpenEmbedded build system uses to place 1700 Debian packages that are ready to be used outside of the build 1701 system. This variable applies only when 1702 :term:`PACKAGE_CLASSES` contains 1703 "package_deb". 1704 1705 The BitBake configuration file initially defines the 1706 :term:`DEPLOY_DIR_DEB` variable as a sub-folder of 1707 :term:`DEPLOY_DIR`:: 1708 1709 DEPLOY_DIR_DEB = "${DEPLOY_DIR}/deb" 1710 1711 The :ref:`package_deb <ref-classes-package_deb>` class uses the 1712 :term:`DEPLOY_DIR_DEB` variable to make sure the 1713 :ref:`ref-tasks-package_write_deb` task 1714 writes Debian packages into the appropriate folder. For more 1715 information on how packaging works, see the 1716 ":ref:`overview-manual/concepts:package feeds`" section 1717 in the Yocto Project Overview and Concepts Manual. 1718 1719 :term:`DEPLOY_DIR_IMAGE` 1720 Points to the area that the OpenEmbedded build system uses to place 1721 images and other associated output files that are ready to be 1722 deployed onto the target machine. The directory is machine-specific 1723 as it contains the ``${MACHINE}`` name. By default, this directory 1724 resides within the :term:`Build Directory` as 1725 ``${DEPLOY_DIR}/images/${MACHINE}/``. 1726 1727 It must not be used directly in recipes when deploying files. Instead, 1728 it's only useful when a recipe needs to "read" a file already deployed 1729 by a dependency. So, it should be filled with the contents of 1730 :term:`DEPLOYDIR` by the :ref:`deploy <ref-classes-deploy>` class or 1731 with the contents of :term:`IMGDEPLOYDIR` by the :ref:`image 1732 <ref-classes-image>` class. 1733 1734 For more information on the structure of the Build Directory, see 1735 ":ref:`ref-manual/structure:the build directory - \`\`build/\`\``" section. 1736 For more detail on the contents of the ``deploy`` directory, see the 1737 ":ref:`overview-manual/concepts:images`" and 1738 ":ref:`overview-manual/concepts:application development sdk`" sections both in 1739 the Yocto Project Overview and Concepts Manual. 1740 1741 :term:`DEPLOY_DIR_IPK` 1742 Points to the area that the OpenEmbedded build system uses to place 1743 IPK packages that are ready to be used outside of the build system. 1744 This variable applies only when 1745 :term:`PACKAGE_CLASSES` contains 1746 "package_ipk". 1747 1748 The BitBake configuration file initially defines this variable as a 1749 sub-folder of :term:`DEPLOY_DIR`:: 1750 1751 DEPLOY_DIR_IPK = "${DEPLOY_DIR}/ipk" 1752 1753 The :ref:`package_ipk <ref-classes-package_ipk>` class uses the 1754 :term:`DEPLOY_DIR_IPK` variable to make sure the 1755 :ref:`ref-tasks-package_write_ipk` task 1756 writes IPK packages into the appropriate folder. For more information 1757 on how packaging works, see the 1758 ":ref:`overview-manual/concepts:package feeds`" section 1759 in the Yocto Project Overview and Concepts Manual. 1760 1761 :term:`DEPLOY_DIR_RPM` 1762 Points to the area that the OpenEmbedded build system uses to place 1763 RPM packages that are ready to be used outside of the build system. 1764 This variable applies only when 1765 :term:`PACKAGE_CLASSES` contains 1766 "package_rpm". 1767 1768 The BitBake configuration file initially defines this variable as a 1769 sub-folder of :term:`DEPLOY_DIR`:: 1770 1771 DEPLOY_DIR_RPM = "${DEPLOY_DIR}/rpm" 1772 1773 The :ref:`package_rpm <ref-classes-package_rpm>` class uses the 1774 :term:`DEPLOY_DIR_RPM` variable to make sure the 1775 :ref:`ref-tasks-package_write_rpm` task 1776 writes RPM packages into the appropriate folder. For more information 1777 on how packaging works, see the 1778 ":ref:`overview-manual/concepts:package feeds`" section 1779 in the Yocto Project Overview and Concepts Manual. 1780 1781 :term:`DEPLOY_DIR_TAR` 1782 Points to the area that the OpenEmbedded build system uses to place 1783 tarballs that are ready to be used outside of the build system. This 1784 variable applies only when 1785 :term:`PACKAGE_CLASSES` contains 1786 "package_tar". 1787 1788 The BitBake configuration file initially defines this variable as a 1789 sub-folder of :term:`DEPLOY_DIR`:: 1790 1791 DEPLOY_DIR_TAR = "${DEPLOY_DIR}/tar" 1792 1793 The :ref:`package_tar <ref-classes-package_tar>` class uses the 1794 :term:`DEPLOY_DIR_TAR` variable to make sure the 1795 :ref:`ref-tasks-package_write_tar` task 1796 writes TAR packages into the appropriate folder. For more information 1797 on how packaging works, see the 1798 ":ref:`overview-manual/concepts:package feeds`" section 1799 in the Yocto Project Overview and Concepts Manual. 1800 1801 :term:`DEPLOYDIR` 1802 When inheriting the :ref:`deploy <ref-classes-deploy>` class, the 1803 :term:`DEPLOYDIR` points to a temporary work area for deployed files that 1804 is set in the :ref:`deploy <ref-classes-deploy>` class as follows:: 1805 1806 DEPLOYDIR = "${WORKDIR}/deploy-${PN}" 1807 1808 Recipes inheriting the :ref:`deploy <ref-classes-deploy>` class should copy files to be 1809 deployed into :term:`DEPLOYDIR`, and the class will take care of copying 1810 them into :term:`DEPLOY_DIR_IMAGE` 1811 afterwards. 1812 1813 :term:`DESCRIPTION` 1814 The package description used by package managers. If not set, 1815 :term:`DESCRIPTION` takes the value of the :term:`SUMMARY` 1816 variable. 1817 1818 :term:`DISTRO` 1819 The short name of the distribution. For information on the long name 1820 of the distribution, see the :term:`DISTRO_NAME` 1821 variable. 1822 1823 The :term:`DISTRO` variable corresponds to a distribution configuration 1824 file whose root name is the same as the variable's argument and whose 1825 filename extension is ``.conf``. For example, the distribution 1826 configuration file for the Poky distribution is named ``poky.conf`` 1827 and resides in the ``meta-poky/conf/distro`` directory of the 1828 :term:`Source Directory`. 1829 1830 Within that ``poky.conf`` file, the :term:`DISTRO` variable is set as 1831 follows:: 1832 1833 DISTRO = "poky" 1834 1835 Distribution configuration files are located in a ``conf/distro`` 1836 directory within the :term:`Metadata` that contains the 1837 distribution configuration. The value for :term:`DISTRO` must not contain 1838 spaces, and is typically all lower-case. 1839 1840 .. note:: 1841 1842 If the :term:`DISTRO` variable is blank, a set of default configurations 1843 are used, which are specified within 1844 ``meta/conf/distro/defaultsetup.conf`` also in the Source Directory. 1845 1846 :term:`DISTRO_CODENAME` 1847 Specifies a codename for the distribution being built. 1848 1849 :term:`DISTRO_EXTRA_RDEPENDS` 1850 Specifies a list of distro-specific packages to add to all images. 1851 This variable takes effect through ``packagegroup-base`` so the 1852 variable only really applies to the more full-featured images that 1853 include ``packagegroup-base``. You can use this variable to keep 1854 distro policy out of generic images. As with all other distro 1855 variables, you set this variable in the distro ``.conf`` file. 1856 1857 :term:`DISTRO_EXTRA_RRECOMMENDS` 1858 Specifies a list of distro-specific packages to add to all images if 1859 the packages exist. The packages might not exist or be empty (e.g. 1860 kernel modules). The list of packages are automatically installed but 1861 you can remove them. 1862 1863 :term:`DISTRO_FEATURES` 1864 The software support you want in your distribution for various 1865 features. You define your distribution features in the distribution 1866 configuration file. 1867 1868 In most cases, the presence or absence of a feature in 1869 :term:`DISTRO_FEATURES` is translated to the appropriate option supplied 1870 to the configure script during the 1871 :ref:`ref-tasks-configure` task for recipes that 1872 optionally support the feature. For example, specifying "x11" in 1873 :term:`DISTRO_FEATURES`, causes every piece of software built for the 1874 target that can optionally support X11 to have its X11 support 1875 enabled. 1876 1877 Two more examples are Bluetooth and NFS support. For a more complete 1878 list of features that ships with the Yocto Project and that you can 1879 provide with this variable, see the ":ref:`ref-features-distro`" section. 1880 1881 :term:`DISTRO_FEATURES_BACKFILL` 1882 Features to be added to :term:`DISTRO_FEATURES` if not also present in 1883 :term:`DISTRO_FEATURES_BACKFILL_CONSIDERED`. 1884 1885 This variable is set in the ``meta/conf/bitbake.conf`` file. It is 1886 not intended to be user-configurable. It is best to just reference 1887 the variable to see which distro features are being backfilled for 1888 all distro configurations. See the ":ref:`ref-features-backfill`" section 1889 for more information. 1890 1891 :term:`DISTRO_FEATURES_BACKFILL_CONSIDERED` 1892 Features from :term:`DISTRO_FEATURES_BACKFILL` that should not be 1893 backfilled (i.e. added to :term:`DISTRO_FEATURES`) during the build. See 1894 the ":ref:`ref-features-backfill`" section for more information. 1895 1896 :term:`DISTRO_FEATURES_DEFAULT` 1897 A convenience variable that gives you the default list of distro 1898 features with the exception of any features specific to the C library 1899 (``libc``). 1900 1901 When creating a custom distribution, you might find it useful to be 1902 able to reuse the default 1903 :term:`DISTRO_FEATURES` options without the 1904 need to write out the full set. Here is an example that uses 1905 :term:`DISTRO_FEATURES_DEFAULT` from a custom distro configuration file:: 1906 1907 DISTRO_FEATURES ?= "${DISTRO_FEATURES_DEFAULT} myfeature" 1908 1909 :term:`DISTRO_FEATURES_FILTER_NATIVE` 1910 Specifies a list of features that if present in the target 1911 :term:`DISTRO_FEATURES` value should be 1912 included in :term:`DISTRO_FEATURES` when building native recipes. This 1913 variable is used in addition to the features filtered using the 1914 :term:`DISTRO_FEATURES_NATIVE` 1915 variable. 1916 1917 :term:`DISTRO_FEATURES_FILTER_NATIVESDK` 1918 Specifies a list of features that if present in the target 1919 :term:`DISTRO_FEATURES` value should be 1920 included in :term:`DISTRO_FEATURES` when building nativesdk recipes. This 1921 variable is used in addition to the features filtered using the 1922 :term:`DISTRO_FEATURES_NATIVESDK` 1923 variable. 1924 1925 :term:`DISTRO_FEATURES_NATIVE` 1926 Specifies a list of features that should be included in 1927 :term:`DISTRO_FEATURES` when building native 1928 recipes. This variable is used in addition to the features filtered 1929 using the 1930 :term:`DISTRO_FEATURES_FILTER_NATIVE` 1931 variable. 1932 1933 :term:`DISTRO_FEATURES_NATIVESDK` 1934 Specifies a list of features that should be included in 1935 :term:`DISTRO_FEATURES` when building 1936 nativesdk recipes. This variable is used in addition to the features 1937 filtered using the 1938 :term:`DISTRO_FEATURES_FILTER_NATIVESDK` 1939 variable. 1940 1941 :term:`DISTRO_NAME` 1942 The long name of the distribution. For information on the short name 1943 of the distribution, see the :term:`DISTRO` variable. 1944 1945 The :term:`DISTRO_NAME` variable corresponds to a distribution 1946 configuration file whose root name is the same as the variable's 1947 argument and whose filename extension is ``.conf``. For example, the 1948 distribution configuration file for the Poky distribution is named 1949 ``poky.conf`` and resides in the ``meta-poky/conf/distro`` directory 1950 of the :term:`Source Directory`. 1951 1952 Within that ``poky.conf`` file, the :term:`DISTRO_NAME` variable is set 1953 as follows:: 1954 1955 DISTRO_NAME = "Poky (Yocto Project Reference Distro)" 1956 1957 Distribution configuration files are located in a ``conf/distro`` 1958 directory within the :term:`Metadata` that contains the 1959 distribution configuration. 1960 1961 .. note:: 1962 1963 If the :term:`DISTRO_NAME` variable is blank, a set of default 1964 configurations are used, which are specified within 1965 ``meta/conf/distro/defaultsetup.conf`` also in the Source Directory. 1966 1967 :term:`DISTRO_VERSION` 1968 The version of the distribution. 1969 1970 :term:`DISTROOVERRIDES` 1971 A colon-separated list of overrides specific to the current 1972 distribution. By default, this list includes the value of 1973 :term:`DISTRO`. 1974 1975 You can extend :term:`DISTROOVERRIDES` to add extra overrides that should 1976 apply to the distribution. 1977 1978 The underlying mechanism behind :term:`DISTROOVERRIDES` is simply that it 1979 is included in the default value of 1980 :term:`OVERRIDES`. 1981 1982 :term:`DL_DIR` 1983 The central download directory used by the build process to store 1984 downloads. By default, :term:`DL_DIR` gets files suitable for mirroring 1985 for everything except Git repositories. If you want tarballs of Git 1986 repositories, use the 1987 :term:`BB_GENERATE_MIRROR_TARBALLS` 1988 variable. 1989 1990 You can set this directory by defining the :term:`DL_DIR` variable in the 1991 ``conf/local.conf`` file. This directory is self-maintaining and you 1992 should not have to touch it. By default, the directory is 1993 ``downloads`` in the :term:`Build Directory`. 1994 :: 1995 1996 #DL_DIR ?= "${TOPDIR}/downloads" 1997 1998 To specify a different download directory, 1999 simply remove the comment from the line and provide your directory. 2000 2001 During a first build, the system downloads many different source code 2002 tarballs from various upstream projects. Downloading can take a 2003 while, particularly if your network connection is slow. Tarballs are 2004 all stored in the directory defined by :term:`DL_DIR` and the build 2005 system looks there first to find source tarballs. 2006 2007 .. note:: 2008 2009 When wiping and rebuilding, you can preserve this directory to 2010 speed up this part of subsequent builds. 2011 2012 You can safely share this directory between multiple builds on the 2013 same development machine. For additional information on how the build 2014 process gets source files when working behind a firewall or proxy 2015 server, see this specific question in the ":doc:`faq`" 2016 chapter. You can also refer to the 2017 ":yocto_wiki:`Working Behind a Network Proxy </Working_Behind_a_Network_Proxy>`" 2018 Wiki page. 2019 2020 :term:`DOC_COMPRESS` 2021 When inheriting the :ref:`compress_doc <ref-classes-compress_doc>` 2022 class, this variable sets the compression policy used when the 2023 OpenEmbedded build system compresses man pages and info pages. By 2024 default, the compression method used is gz (gzip). Other policies 2025 available are xz and bz2. 2026 2027 For information on policies and on how to use this variable, see the 2028 comments in the ``meta/classes/compress_doc.bbclass`` file. 2029 2030 :term:`EFI_PROVIDER` 2031 When building bootable images (i.e. where ``hddimg``, ``iso``, or 2032 ``wic.vmdk`` is in :term:`IMAGE_FSTYPES`), the 2033 :term:`EFI_PROVIDER` variable specifies the EFI bootloader to use. The 2034 default is "grub-efi", but "systemd-boot" can be used instead. 2035 2036 See the :ref:`systemd-boot <ref-classes-systemd-boot>` and 2037 :ref:`image-live <ref-classes-image-live>` classes for more 2038 information. 2039 2040 :term:`ENABLE_BINARY_LOCALE_GENERATION` 2041 Variable that controls which locales for ``glibc`` are generated 2042 during the build (useful if the target device has 64Mbytes of RAM or 2043 less). 2044 2045 :term:`ERR_REPORT_DIR` 2046 When used with the :ref:`report-error <ref-classes-report-error>` 2047 class, specifies the path used for storing the debug files created by 2048 the :ref:`error reporting 2049 tool <dev-manual/common-tasks:using the error reporting tool>`, which 2050 allows you to submit build errors you encounter to a central 2051 database. By default, the value of this variable is 2052 ``${``\ :term:`LOG_DIR`\ ``}/error-report``. 2053 2054 You can set :term:`ERR_REPORT_DIR` to the path you want the error 2055 reporting tool to store the debug files as follows in your 2056 ``local.conf`` file:: 2057 2058 ERR_REPORT_DIR = "path" 2059 2060 :term:`ERROR_QA` 2061 Specifies the quality assurance checks whose failures are reported as 2062 errors by the OpenEmbedded build system. You set this variable in 2063 your distribution configuration file. For a list of the checks you 2064 can control with this variable, see the 2065 ":ref:`ref-classes-insane`" section. 2066 2067 :term:`ESDK_CLASS_INHERIT_DISABLE` 2068 A list of classes to remove from the :term:`INHERIT` 2069 value globally within the extensible SDK configuration. The 2070 :ref:`populate-sdk-ext <ref-classes-populate-sdk-*>` class sets the 2071 default value:: 2072 2073 ESDK_CLASS_INHERIT_DISABLE ?= "buildhistory icecc" 2074 2075 Some classes are not generally applicable within the extensible SDK 2076 context. You can use this variable to disable those classes. 2077 2078 For additional information on how to customize the extensible SDK's 2079 configuration, see the 2080 ":ref:`sdk-manual/appendix-customizing:configuring the extensible sdk`" 2081 section in the Yocto Project Application Development and the 2082 Extensible Software Development Kit (eSDK) manual. 2083 2084 :term:`ESDK_LOCALCONF_ALLOW` 2085 A list of variables allowed through from the OpenEmbedded build 2086 system configuration into the extensible SDK configuration. By 2087 default, the list of variables is empty and is set in the 2088 :ref:`populate-sdk-ext <ref-classes-populate-sdk-*>` class. 2089 2090 This list overrides the variables specified using the 2091 :term:`ESDK_LOCALCONF_REMOVE` variable as well as 2092 other variables automatically added due to the "/" character 2093 being found at the start of the 2094 value, which is usually indicative of being a path and thus might not 2095 be valid on the system where the SDK is installed. 2096 2097 For additional information on how to customize the extensible SDK's 2098 configuration, see the 2099 ":ref:`sdk-manual/appendix-customizing:configuring the extensible sdk`" 2100 section in the Yocto Project Application Development and the 2101 Extensible Software Development Kit (eSDK) manual. 2102 2103 :term:`ESDK_LOCALCONF_REMOVE` 2104 A list of variables not allowed through from the OpenEmbedded build 2105 system configuration into the extensible SDK configuration. Usually, 2106 these are variables that are specific to the machine on which the 2107 build system is running and thus would be potentially problematic 2108 within the extensible SDK. 2109 2110 By default, :term:`ESDK_LOCALCONF_REMOVE` is set in the 2111 :ref:`populate-sdk-ext <ref-classes-populate-sdk-*>` class and 2112 excludes the following variables: 2113 2114 - :term:`CONF_VERSION` 2115 - :term:`BB_NUMBER_THREADS` 2116 - :term:`BB_NUMBER_PARSE_THREADS` 2117 - :term:`PARALLEL_MAKE` 2118 - :term:`PRSERV_HOST` 2119 - :term:`SSTATE_MIRRORS` :term:`DL_DIR` 2120 - :term:`SSTATE_DIR` :term:`TMPDIR` 2121 - :term:`BB_SERVER_TIMEOUT` 2122 2123 For additional information on how to customize the extensible SDK's 2124 configuration, see the 2125 ":ref:`sdk-manual/appendix-customizing:configuring the extensible sdk`" 2126 section in the Yocto Project Application Development and the 2127 Extensible Software Development Kit (eSDK) manual. 2128 2129 :term:`EXCLUDE_FROM_SHLIBS` 2130 Triggers the OpenEmbedded build system's shared libraries resolver to 2131 exclude an entire package when scanning for shared libraries. 2132 2133 .. note:: 2134 2135 The shared libraries resolver's functionality results in part from 2136 the internal function ``package_do_shlibs``, which is part of the 2137 :ref:`ref-tasks-package` task. You should be aware that the shared 2138 libraries resolver might implicitly define some dependencies between 2139 packages. 2140 2141 The :term:`EXCLUDE_FROM_SHLIBS` variable is similar to the 2142 :term:`PRIVATE_LIBS` variable, which excludes a 2143 package's particular libraries only and not the whole package. 2144 2145 Use the :term:`EXCLUDE_FROM_SHLIBS` variable by setting it to "1" for a 2146 particular package:: 2147 2148 EXCLUDE_FROM_SHLIBS = "1" 2149 2150 :term:`EXCLUDE_FROM_WORLD` 2151 Directs BitBake to exclude a recipe from world builds (i.e. 2152 ``bitbake world``). During world builds, BitBake locates, parses and 2153 builds all recipes found in every layer exposed in the 2154 ``bblayers.conf`` configuration file. 2155 2156 To exclude a recipe from a world build using this variable, set the 2157 variable to "1" in the recipe. 2158 2159 .. note:: 2160 2161 Recipes added to :term:`EXCLUDE_FROM_WORLD` may still be built during a 2162 world build in order to satisfy dependencies of other recipes. Adding 2163 a recipe to :term:`EXCLUDE_FROM_WORLD` only ensures that the recipe is not 2164 explicitly added to the list of build targets in a world build. 2165 2166 :term:`EXTENDPE` 2167 Used with file and pathnames to create a prefix for a recipe's 2168 version based on the recipe's :term:`PE` value. If :term:`PE` 2169 is set and greater than zero for a recipe, :term:`EXTENDPE` becomes that 2170 value (e.g if :term:`PE` is equal to "1" then :term:`EXTENDPE` becomes "1"). 2171 If a recipe's :term:`PE` is not set (the default) or is equal to zero, 2172 :term:`EXTENDPE` becomes "". 2173 2174 See the :term:`STAMP` variable for an example. 2175 2176 :term:`EXTENDPKGV` 2177 The full package version specification as it appears on the final 2178 packages produced by a recipe. The variable's value is normally used 2179 to fix a runtime dependency to the exact same version of another 2180 package in the same recipe:: 2181 2182 RDEPENDS:${PN}-additional-module = "${PN} (= ${EXTENDPKGV})" 2183 2184 The dependency relationships are intended to force the package 2185 manager to upgrade these types of packages in lock-step. 2186 2187 :term:`EXTERNAL_KERNEL_TOOLS` 2188 When set, the :term:`EXTERNAL_KERNEL_TOOLS` variable indicates that these 2189 tools are not in the source tree. 2190 2191 When kernel tools are available in the tree, they are preferred over 2192 any externally installed tools. Setting the :term:`EXTERNAL_KERNEL_TOOLS` 2193 variable tells the OpenEmbedded build system to prefer the installed 2194 external tools. See the 2195 :ref:`kernel-yocto <ref-classes-kernel-yocto>` class in 2196 ``meta/classes`` to see how the variable is used. 2197 2198 :term:`EXTERNALSRC` 2199 When inheriting the :ref:`externalsrc <ref-classes-externalsrc>` 2200 class, this variable points to the source tree, which is outside of 2201 the OpenEmbedded build system. When set, this variable sets the 2202 :term:`S` variable, which is what the OpenEmbedded build 2203 system uses to locate unpacked recipe source code. 2204 2205 See the ":ref:`ref-classes-externalsrc`" section for details. You 2206 can also find information on how to use this variable in the 2207 ":ref:`dev-manual/common-tasks:building software from an external source`" 2208 section in the Yocto Project Development Tasks Manual. 2209 2210 :term:`EXTERNALSRC_BUILD` 2211 When inheriting the :ref:`externalsrc <ref-classes-externalsrc>` 2212 class, this variable points to the directory in which the recipe's 2213 source code is built, which is outside of the OpenEmbedded build 2214 system. When set, this variable sets the :term:`B` variable, 2215 which is what the OpenEmbedded build system uses to locate the Build 2216 Directory. 2217 2218 See the ":ref:`ref-classes-externalsrc`" section for details. You 2219 can also find information on how to use this variable in the 2220 ":ref:`dev-manual/common-tasks:building software from an external source`" 2221 section in the Yocto Project Development Tasks Manual. 2222 2223 :term:`EXTRA_AUTORECONF` 2224 For recipes inheriting the :ref:`autotools <ref-classes-autotools>` 2225 class, you can use :term:`EXTRA_AUTORECONF` to specify extra options to 2226 pass to the ``autoreconf`` command that is executed during the 2227 :ref:`ref-tasks-configure` task. 2228 2229 The default value is "--exclude=autopoint". 2230 2231 :term:`EXTRA_IMAGE_FEATURES` 2232 A list of additional features to include in an image. When listing 2233 more than one feature, separate them with a space. 2234 2235 Typically, you configure this variable in your ``local.conf`` file, 2236 which is found in the :term:`Build Directory`. 2237 Although you can use this variable from within a recipe, best 2238 practices dictate that you do not. 2239 2240 .. note:: 2241 2242 To enable primary features from within the image recipe, use the 2243 :term:`IMAGE_FEATURES` variable. 2244 2245 Here are some examples of features you can add: 2246 2247 - "dbg-pkgs" - Adds -dbg packages for all installed packages including 2248 symbol information for debugging and profiling. 2249 2250 - "debug-tweaks" - Makes an image suitable for debugging. For example, allows root logins without passwords and 2251 enables post-installation logging. See the 'allow-empty-password' and 2252 'post-install-logging' features in the ":ref:`ref-features-image`" 2253 section for more information. 2254 - "dev-pkgs" - Adds -dev packages for all installed packages. This is 2255 useful if you want to develop against the libraries in the image. 2256 - "read-only-rootfs" - Creates an image whose root filesystem is 2257 read-only. See the 2258 ":ref:`dev-manual/common-tasks:creating a read-only root filesystem`" 2259 section in the Yocto Project Development Tasks Manual for more 2260 information 2261 - "tools-debug" - Adds debugging tools such as gdb and strace. 2262 - "tools-sdk" - Adds development tools such as gcc, make, 2263 pkgconfig and so forth. 2264 - "tools-testapps" - Adds useful testing tools 2265 such as ts_print, aplay, arecord and so forth. 2266 2267 For a complete list of image features that ships with the Yocto 2268 Project, see the ":ref:`ref-features-image`" section. 2269 2270 For an example that shows how to customize your image by using this 2271 variable, see the ":ref:`dev-manual/common-tasks:customizing images using custom \`\`image_features\`\` and \`\`extra_image_features\`\``" 2272 section in the Yocto Project Development Tasks Manual. 2273 2274 :term:`EXTRA_IMAGECMD` 2275 Specifies additional options for the image creation command that has 2276 been specified in :term:`IMAGE_CMD`. When setting 2277 this variable, use an override for the associated image type. Here is 2278 an example:: 2279 2280 EXTRA_IMAGECMD:ext3 ?= "-i 4096" 2281 2282 :term:`EXTRA_IMAGEDEPENDS` 2283 A list of recipes to build that do not provide packages for 2284 installing into the root filesystem. 2285 2286 Sometimes a recipe is required to build the final image but is not 2287 needed in the root filesystem. You can use the :term:`EXTRA_IMAGEDEPENDS` 2288 variable to list these recipes and thus specify the dependencies. A 2289 typical example is a required bootloader in a machine configuration. 2290 2291 .. note:: 2292 2293 To add packages to the root filesystem, see the various 2294 :term:`RDEPENDS` and :term:`RRECOMMENDS` variables. 2295 2296 :term:`EXTRA_OECMAKE` 2297 Additional `CMake <https://cmake.org/overview/>`__ options. See the 2298 :ref:`cmake <ref-classes-cmake>` class for additional information. 2299 2300 :term:`EXTRA_OECONF` 2301 Additional ``configure`` script options. See 2302 :term:`PACKAGECONFIG_CONFARGS` for 2303 additional information on passing configure script options. 2304 2305 :term:`EXTRA_OEMAKE` 2306 Additional GNU ``make`` options. 2307 2308 Because the :term:`EXTRA_OEMAKE` defaults to "", you need to set the 2309 variable to specify any required GNU options. 2310 2311 :term:`PARALLEL_MAKE` and 2312 :term:`PARALLEL_MAKEINST` also make use of 2313 :term:`EXTRA_OEMAKE` to pass the required flags. 2314 2315 :term:`EXTRA_OESCONS` 2316 When inheriting the :ref:`scons <ref-classes-scons>` class, this 2317 variable specifies additional configuration options you want to pass 2318 to the ``scons`` command line. 2319 2320 :term:`EXTRA_USERS_PARAMS` 2321 When inheriting the :ref:`extrausers <ref-classes-extrausers>` 2322 class, this variable provides image level user and group operations. 2323 This is a more global method of providing user and group 2324 configuration as compared to using the 2325 :ref:`useradd <ref-classes-useradd>` class, which ties user and 2326 group configurations to a specific recipe. 2327 2328 The set list of commands you can configure using the 2329 :term:`EXTRA_USERS_PARAMS` is shown in the :ref:`extrausers <ref-classes-extrausers>` class. These 2330 commands map to the normal Unix commands of the same names:: 2331 2332 # EXTRA_USERS_PARAMS = "\ 2333 # useradd -p '' tester; \ 2334 # groupadd developers; \ 2335 # userdel nobody; \ 2336 # groupdel -g video; \ 2337 # groupmod -g 1020 developers; \ 2338 # usermod -s /bin/sh tester; \ 2339 # " 2340 2341 Hardcoded passwords are supported via the ``-p`` parameters for 2342 ``useradd`` or ``usermod``, but only hashed. 2343 2344 Here is an example that adds two users named "tester-jim" and "tester-sue" and assigns 2345 passwords. First on host, create the (escaped) password hash:: 2346 2347 printf "%q" $(mkpasswd -m sha256crypt tester01) 2348 2349 The resulting hash is set to a variable and used in ``useradd`` command parameters:: 2350 2351 inherit extrausers 2352 PASSWD = "\$X\$ABC123\$A-Long-Hash" 2353 EXTRA_USERS_PARAMS = "\ 2354 useradd -p '${PASSWD}' tester-jim; \ 2355 useradd -p '${PASSWD}' tester-sue; \ 2356 " 2357 2358 Finally, here is an example that sets the root password:: 2359 2360 inherit extrausers 2361 EXTRA_USERS_PARAMS = "\ 2362 usermod -p '${PASSWD}' root; \ 2363 " 2364 2365 .. note:: 2366 2367 From a security perspective, hardcoding a default password is not 2368 generally a good idea or even legal in some jurisdictions. It is 2369 recommended that you do not do this if you are building a production 2370 image. 2371 2372 Additionally there is a special ``passwd-expire`` command that will 2373 cause the password for a user to be expired and thus force changing it 2374 on first login, for example:: 2375 2376 EXTRA_USERS_PARAMS += " useradd myuser; passwd-expire myuser;" 2377 2378 .. note:: 2379 2380 At present, ``passwd-expire`` may only work for remote logins when 2381 using OpenSSH and not dropbear as an SSH server. 2382 2383 :term:`EXTRANATIVEPATH` 2384 A list of subdirectories of 2385 ``${``\ :term:`STAGING_BINDIR_NATIVE`\ ``}`` 2386 added to the beginning of the environment variable ``PATH``. As an 2387 example, the following prepends 2388 "${STAGING_BINDIR_NATIVE}/foo:${STAGING_BINDIR_NATIVE}/bar:" to 2389 ``PATH``:: 2390 2391 EXTRANATIVEPATH = "foo bar" 2392 2393 :term:`FEATURE_PACKAGES` 2394 Defines one or more packages to include in an image when a specific 2395 item is included in :term:`IMAGE_FEATURES`. 2396 When setting the value, :term:`FEATURE_PACKAGES` should have the name of 2397 the feature item as an override. Here is an example:: 2398 2399 FEATURE_PACKAGES_widget = "package1 package2" 2400 2401 In this example, if "widget" were added to :term:`IMAGE_FEATURES`, 2402 package1 and package2 would be included in the image. 2403 2404 .. note:: 2405 2406 Packages installed by features defined through :term:`FEATURE_PACKAGES` 2407 are often package groups. While similarly named, you should not 2408 confuse the :term:`FEATURE_PACKAGES` variable with package groups, which 2409 are discussed elsewhere in the documentation. 2410 2411 :term:`FEED_DEPLOYDIR_BASE_URI` 2412 Points to the base URL of the server and location within the 2413 document-root that provides the metadata and packages required by 2414 OPKG to support runtime package management of IPK packages. You set 2415 this variable in your ``local.conf`` file. 2416 2417 Consider the following example:: 2418 2419 FEED_DEPLOYDIR_BASE_URI = "http://192.168.7.1/BOARD-dir" 2420 2421 This example assumes you are serving 2422 your packages over HTTP and your databases are located in a directory 2423 named ``BOARD-dir``, which is underneath your HTTP server's 2424 document-root. In this case, the OpenEmbedded build system generates 2425 a set of configuration files for you in your target that work with 2426 the feed. 2427 2428 :term:`FILES` 2429 The list of files and directories that are placed in a package. The 2430 :term:`PACKAGES` variable lists the packages 2431 generated by a recipe. 2432 2433 To use the :term:`FILES` variable, provide a package name override that 2434 identifies the resulting package. Then, provide a space-separated 2435 list of files or paths that identify the files you want included as 2436 part of the resulting package. Here is an example:: 2437 2438 FILES:${PN} += "${bindir}/mydir1 ${bindir}/mydir2/myfile" 2439 2440 .. note:: 2441 2442 - When specifying files or paths, you can pattern match using 2443 Python's 2444 `glob <https://docs.python.org/3/library/glob.html>`_ 2445 syntax. For details on the syntax, see the documentation by 2446 following the previous link. 2447 2448 - When specifying paths as part of the :term:`FILES` variable, it is 2449 good practice to use appropriate path variables. For example, 2450 use ``${sysconfdir}`` rather than ``/etc``, or ``${bindir}`` 2451 rather than ``/usr/bin``. You can find a list of these 2452 variables at the top of the ``meta/conf/bitbake.conf`` file in 2453 the :term:`Source Directory`. You will also 2454 find the default values of the various ``FILES:*`` variables in 2455 this file. 2456 2457 If some of the files you provide with the :term:`FILES` variable are 2458 editable and you know they should not be overwritten during the 2459 package update process by the Package Management System (PMS), you 2460 can identify these files so that the PMS will not overwrite them. See 2461 the :term:`CONFFILES` variable for information on 2462 how to identify these files to the PMS. 2463 2464 :term:`FILES_SOLIBSDEV` 2465 Defines the file specification to match 2466 :term:`SOLIBSDEV`. In other words, 2467 :term:`FILES_SOLIBSDEV` defines the full path name of the development 2468 symbolic link (symlink) for shared libraries on the target platform. 2469 2470 The following statement from the ``bitbake.conf`` shows how it is 2471 set:: 2472 2473 FILES_SOLIBSDEV ?= "${base_libdir}/lib*${SOLIBSDEV} ${libdir}/lib*${SOLIBSDEV}" 2474 2475 :term:`FILESEXTRAPATHS` 2476 Extends the search path the OpenEmbedded build system uses when 2477 looking for files and patches as it processes recipes and append 2478 files. The default directories BitBake uses when it processes recipes 2479 are initially defined by the :term:`FILESPATH` 2480 variable. You can extend :term:`FILESPATH` variable by using 2481 :term:`FILESEXTRAPATHS`. 2482 2483 Best practices dictate that you accomplish this by using 2484 :term:`FILESEXTRAPATHS` from within a ``.bbappend`` file and that you 2485 prepend paths as follows:: 2486 2487 FILESEXTRAPATHS:prepend := "${THISDIR}/${PN}:" 2488 2489 In the above example, the build system first 2490 looks for files in a directory that has the same name as the 2491 corresponding append file. 2492 2493 .. note:: 2494 2495 When extending :term:`FILESEXTRAPATHS`, be sure to use the immediate 2496 expansion (``:=``) operator. Immediate expansion makes sure that 2497 BitBake evaluates :term:`THISDIR` at the time the 2498 directive is encountered rather than at some later time when 2499 expansion might result in a directory that does not contain the 2500 files you need. 2501 2502 Also, include the trailing separating colon character if you are 2503 prepending. The trailing colon character is necessary because you 2504 are directing BitBake to extend the path by prepending directories 2505 to the search path. 2506 2507 Here is another common use:: 2508 2509 FILESEXTRAPATHS:prepend := "${THISDIR}/files:" 2510 2511 In this example, the build system extends the 2512 :term:`FILESPATH` variable to include a directory named ``files`` that is 2513 in the same directory as the corresponding append file. 2514 2515 This next example specifically adds three paths:: 2516 2517 FILESEXTRAPATHS:prepend := "path_1:path_2:path_3:" 2518 2519 A final example shows how you can extend the search path and include 2520 a :term:`MACHINE`-specific override, which is useful 2521 in a BSP layer:: 2522 2523 FILESEXTRAPATHS:prepend:intel-x86-common := "${THISDIR}/${PN}:" 2524 2525 The previous statement appears in the 2526 ``linux-yocto-dev.bbappend`` file, which is found in the 2527 :ref:`overview-manual/development-environment:yocto project source repositories` in 2528 ``meta-intel/common/recipes-kernel/linux``. Here, the machine 2529 override is a special :term:`PACKAGE_ARCH` 2530 definition for multiple ``meta-intel`` machines. 2531 2532 .. note:: 2533 2534 For a layer that supports a single BSP, the override could just be 2535 the value of :term:`MACHINE`. 2536 2537 By prepending paths in ``.bbappend`` files, you allow multiple append 2538 files that reside in different layers but are used for the same 2539 recipe to correctly extend the path. 2540 2541 :term:`FILESOVERRIDES` 2542 A subset of :term:`OVERRIDES` used by the 2543 OpenEmbedded build system for creating 2544 :term:`FILESPATH`. The :term:`FILESOVERRIDES` variable 2545 uses overrides to automatically extend the 2546 :term:`FILESPATH` variable. For an example of how 2547 that works, see the :term:`FILESPATH` variable 2548 description. Additionally, you find more information on how overrides 2549 are handled in the 2550 ":ref:`bitbake:bitbake-user-manual/bitbake-user-manual-metadata:conditional syntax (overrides)`" 2551 section of the BitBake User Manual. 2552 2553 By default, the :term:`FILESOVERRIDES` variable is defined as:: 2554 2555 FILESOVERRIDES = "${TRANSLATED_TARGET_ARCH}:${MACHINEOVERRIDES}:${DISTROOVERRIDES}" 2556 2557 .. note:: 2558 2559 Do not hand-edit the :term:`FILESOVERRIDES` variable. The values match up 2560 with expected overrides and are used in an expected manner by the 2561 build system. 2562 2563 :term:`FILESPATH` 2564 The default set of directories the OpenEmbedded build system uses 2565 when searching for patches and files. 2566 2567 During the build process, BitBake searches each directory in 2568 :term:`FILESPATH` in the specified order when looking for files and 2569 patches specified by each ``file://`` URI in a recipe's 2570 :term:`SRC_URI` statements. 2571 2572 The default value for the :term:`FILESPATH` variable is defined in the 2573 :ref:`ref-classes-base` class found in ``meta/classes`` in the 2574 :term:`Source Directory`:: 2575 2576 FILESPATH = "${@base_set_filespath(["${FILE_DIRNAME}/${BP}", \ 2577 "${FILE_DIRNAME}/${BPN}", "${FILE_DIRNAME}/files"], d)}" 2578 2579 The 2580 :term:`FILESPATH` variable is automatically extended using the overrides 2581 from the :term:`FILESOVERRIDES` variable. 2582 2583 .. note:: 2584 2585 - Do not hand-edit the :term:`FILESPATH` variable. If you want the 2586 build system to look in directories other than the defaults, 2587 extend the :term:`FILESPATH` variable by using the 2588 :term:`FILESEXTRAPATHS` variable. 2589 2590 - Be aware that the default :term:`FILESPATH` directories do not map 2591 to directories in custom layers where append files 2592 (``.bbappend``) are used. If you want the build system to find 2593 patches or files that reside with your append files, you need 2594 to extend the :term:`FILESPATH` variable by using the 2595 :term:`FILESEXTRAPATHS` variable. 2596 2597 You can take advantage of this searching behavior in useful ways. For 2598 example, consider a case where there is the following directory structure 2599 for general and machine-specific configurations:: 2600 2601 files/defconfig 2602 files/MACHINEA/defconfig 2603 files/MACHINEB/defconfig 2604 2605 Also in the example, the :term:`SRC_URI` statement contains 2606 "file://defconfig". Given this scenario, you can set 2607 :term:`MACHINE` to "MACHINEA" and cause the build 2608 system to use files from ``files/MACHINEA``. Set :term:`MACHINE` to 2609 "MACHINEB" and the build system uses files from ``files/MACHINEB``. 2610 Finally, for any machine other than "MACHINEA" and "MACHINEB", the 2611 build system uses files from ``files/defconfig``. 2612 2613 You can find out more about the patching process in the 2614 ":ref:`overview-manual/concepts:patching`" section 2615 in the Yocto Project Overview and Concepts Manual and the 2616 ":ref:`dev-manual/common-tasks:patching code`" section in 2617 the Yocto Project Development Tasks Manual. See the 2618 :ref:`ref-tasks-patch` task as well. 2619 2620 :term:`FILESYSTEM_PERMS_TABLES` 2621 Allows you to define your own file permissions settings table as part 2622 of your configuration for the packaging process. For example, suppose 2623 you need a consistent set of custom permissions for a set of groups 2624 and users across an entire work project. It is best to do this in the 2625 packages themselves but this is not always possible. 2626 2627 By default, the OpenEmbedded build system uses the ``fs-perms.txt``, 2628 which is located in the ``meta/files`` folder in the :term:`Source Directory`. 2629 If you create your own file 2630 permissions setting table, you should place it in your layer or the 2631 distro's layer. 2632 2633 You define the :term:`FILESYSTEM_PERMS_TABLES` variable in the 2634 ``conf/local.conf`` file, which is found in the :term:`Build Directory`, 2635 to point to your custom 2636 ``fs-perms.txt``. You can specify more than a single file permissions 2637 setting table. The paths you specify to these files must be defined 2638 within the :term:`BBPATH` variable. 2639 2640 For guidance on how to create your own file permissions settings 2641 table file, examine the existing ``fs-perms.txt``. 2642 2643 :term:`FIT_DESC` 2644 Specifies the description string encoded into a fitImage. The default 2645 value is set by the :ref:`kernel-fitimage <ref-classes-kernel-fitimage>` 2646 class as follows:: 2647 2648 FIT_DESC ?= "U-Boot fitImage for ${DISTRO_NAME}/${PV}/${MACHINE}" 2649 2650 :term:`FIT_GENERATE_KEYS` 2651 Decides whether to generate the keys for signing fitImage if they 2652 don't already exist. The keys are created in :term:`UBOOT_SIGN_KEYDIR`. 2653 The default value is 0. 2654 2655 :term:`FIT_HASH_ALG` 2656 Specifies the hash algorithm used in creating the FIT Image. For e.g. sha256. 2657 2658 :term:`FIT_KERNEL_COMP_ALG` 2659 Compression algorithm to use for the kernel image inside the FIT Image. 2660 At present, the only supported values are "gzip" (default) or "none" 2661 If you set this variable to anything other than "none" you may also need 2662 to set :term:`FIT_KERNEL_COMP_ALG_EXTENSION`. 2663 2664 :term:`FIT_KERNEL_COMP_ALG_EXTENSION` 2665 File extension corresponding to :term:`FIT_KERNEL_COMP_ALG`. The default 2666 value is ".gz". 2667 2668 :term:`FIT_KEY_GENRSA_ARGS` 2669 Arguments to openssl genrsa for generating RSA private key for signing 2670 fitImage. The default value is "-F4". i.e. the public exponent 65537 to 2671 use. 2672 2673 :term:`FIT_KEY_REQ_ARGS` 2674 Arguments to openssl req for generating certificate for signing fitImage. 2675 The default value is "-batch -new". batch for non interactive mode 2676 and new for generating new keys. 2677 2678 :term:`FIT_KEY_SIGN_PKCS` 2679 Format for public key certificate used in signing fitImage. 2680 The default value is "x509". 2681 2682 :term:`FIT_SIGN_ALG` 2683 Specifies the signature algorithm used in creating the FIT Image. 2684 For e.g. rsa2048. 2685 2686 :term:`FIT_SIGN_INDIVIDUAL` 2687 If set to "1", then the :ref:`kernel-fitimage <ref-classes-kernel-fitimage>` 2688 class will sign the kernel, dtb and ramdisk images individually in addition 2689 to signing the fitImage itself. This could be useful if you are 2690 intending to verify signatures in another context than booting via 2691 U-Boot. 2692 2693 :term:`FIT_SIGN_NUMBITS` 2694 Size of private key in number of bits used in fitImage. The default 2695 value is "2048". 2696 2697 :term:`FONT_EXTRA_RDEPENDS` 2698 When inheriting the :ref:`fontcache <ref-classes-fontcache>` class, 2699 this variable specifies the runtime dependencies for font packages. 2700 By default, the :term:`FONT_EXTRA_RDEPENDS` is set to "fontconfig-utils". 2701 2702 :term:`FONT_PACKAGES` 2703 When inheriting the :ref:`fontcache <ref-classes-fontcache>` class, 2704 this variable identifies packages containing font files that need to 2705 be cached by Fontconfig. By default, the :ref:`fontcache <ref-classes-fontcache>` class assumes 2706 that fonts are in the recipe's main package (i.e. 2707 ``${``\ :term:`PN`\ ``}``). Use this variable if fonts you 2708 need are in a package other than that main package. 2709 2710 :term:`FORCE_RO_REMOVE` 2711 Forces the removal of the packages listed in ``ROOTFS_RO_UNNEEDED`` 2712 during the generation of the root filesystem. 2713 2714 Set the variable to "1" to force the removal of these packages. 2715 2716 :term:`FULL_OPTIMIZATION` 2717 The options to pass in :term:`TARGET_CFLAGS` and :term:`CFLAGS` when 2718 compiling an optimized system. This variable defaults to "-O2 -pipe 2719 ${DEBUG_FLAGS}". 2720 2721 :term:`GCCPIE` 2722 Enables Position Independent Executables (PIE) within the GNU C 2723 Compiler (GCC). Enabling PIE in the GCC makes Return Oriented 2724 Programming (ROP) attacks much more difficult to execute. 2725 2726 By default the ``security_flags.inc`` file enables PIE by setting the 2727 variable as follows:: 2728 2729 GCCPIE ?= "--enable-default-pie" 2730 2731 :term:`GCCVERSION` 2732 Specifies the default version of the GNU C Compiler (GCC) used for 2733 compilation. By default, :term:`GCCVERSION` is set to "8.x" in the 2734 ``meta/conf/distro/include/tcmode-default.inc`` include file:: 2735 2736 GCCVERSION ?= "8.%" 2737 2738 You can override this value by setting it in a 2739 configuration file such as the ``local.conf``. 2740 2741 :term:`GDB` 2742 The minimal command and arguments to run the GNU Debugger. 2743 2744 :term:`GIR_EXTRA_LIBS_PATH` 2745 Allows to specify an extra search path for ``.so`` files 2746 in GLib related recipes using GObject introspection, 2747 and which do not compile without this setting. 2748 See the ":ref:`dev-manual/common-tasks:enabling gobject introspection support`" 2749 section for details. 2750 2751 :term:`GITDIR` 2752 The directory in which a local copy of a Git repository is stored 2753 when it is cloned. 2754 2755 :term:`GLIBC_GENERATE_LOCALES` 2756 Specifies the list of GLIBC locales to generate should you not wish 2757 to generate all LIBC locals, which can be time consuming. 2758 2759 .. note:: 2760 2761 If you specifically remove the locale ``en_US.UTF-8``, you must set 2762 :term:`IMAGE_LINGUAS` appropriately. 2763 2764 You can set :term:`GLIBC_GENERATE_LOCALES` in your ``local.conf`` file. 2765 By default, all locales are generated. 2766 :: 2767 2768 GLIBC_GENERATE_LOCALES = "en_GB.UTF-8 en_US.UTF-8" 2769 2770 :term:`GROUPADD_PARAM` 2771 When inheriting the :ref:`useradd <ref-classes-useradd>` class, 2772 this variable specifies for a package what parameters should be 2773 passed to the ``groupadd`` command if you wish to add a group to the 2774 system when the package is installed. 2775 2776 Here is an example from the ``dbus`` recipe:: 2777 2778 GROUPADD_PARAM:${PN} = "-r netdev" 2779 2780 For information on the standard Linux shell command 2781 ``groupadd``, see https://linux.die.net/man/8/groupadd. 2782 2783 :term:`GROUPMEMS_PARAM` 2784 When inheriting the :ref:`useradd <ref-classes-useradd>` class, 2785 this variable specifies for a package what parameters should be 2786 passed to the ``groupmems`` command if you wish to modify the members 2787 of a group when the package is installed. 2788 2789 For information on the standard Linux shell command ``groupmems``, 2790 see https://linux.die.net/man/8/groupmems. 2791 2792 :term:`GRUB_GFXSERIAL` 2793 Configures the GNU GRand Unified Bootloader (GRUB) to have graphics 2794 and serial in the boot menu. Set this variable to "1" in your 2795 ``local.conf`` or distribution configuration file to enable graphics 2796 and serial in the menu. 2797 2798 See the :ref:`grub-efi <ref-classes-grub-efi>` class for more 2799 information on how this variable is used. 2800 2801 :term:`GRUB_OPTS` 2802 Additional options to add to the GNU GRand Unified Bootloader (GRUB) 2803 configuration. Use a semi-colon character (``;``) to separate 2804 multiple options. 2805 2806 The :term:`GRUB_OPTS` variable is optional. See the 2807 :ref:`grub-efi <ref-classes-grub-efi>` class for more information 2808 on how this variable is used. 2809 2810 :term:`GRUB_TIMEOUT` 2811 Specifies the timeout before executing the default ``LABEL`` in the 2812 GNU GRand Unified Bootloader (GRUB). 2813 2814 The :term:`GRUB_TIMEOUT` variable is optional. See the 2815 :ref:`grub-efi <ref-classes-grub-efi>` class for more information 2816 on how this variable is used. 2817 2818 :term:`GTKIMMODULES_PACKAGES` 2819 When inheriting the 2820 :ref:`gtk-immodules-cache <ref-classes-gtk-immodules-cache>` class, 2821 this variable specifies the packages that contain the GTK+ input 2822 method modules being installed when the modules are in packages other 2823 than the main package. 2824 2825 :term:`HOMEPAGE` 2826 Website where more information about the software the recipe is 2827 building can be found. 2828 2829 :term:`HOST_ARCH` 2830 The name of the target architecture, which is normally the same as 2831 :term:`TARGET_ARCH`. The OpenEmbedded build system 2832 supports many architectures. Here is an example list of architectures 2833 supported. This list is by no means complete as the architecture is 2834 configurable: 2835 2836 - arm 2837 - i586 2838 - x86_64 2839 - powerpc 2840 - powerpc64 2841 - mips 2842 - mipsel 2843 2844 :term:`HOST_CC_ARCH` 2845 Specifies architecture-specific compiler flags that are passed to the 2846 C compiler. 2847 2848 Default initialization for :term:`HOST_CC_ARCH` varies depending on what 2849 is being built: 2850 2851 - :term:`TARGET_CC_ARCH` when building for the 2852 target 2853 2854 - :term:`BUILD_CC_ARCH` when building for the build host (i.e. 2855 ``-native``) 2856 2857 - ``BUILDSDK_CC_ARCH`` when building for an SDK (i.e. 2858 ``nativesdk-``) 2859 2860 :term:`HOST_OS` 2861 Specifies the name of the target operating system, which is normally 2862 the same as the :term:`TARGET_OS`. The variable can 2863 be set to "linux" for ``glibc``-based systems and to "linux-musl" for 2864 ``musl``. For ARM/EABI targets, there are also "linux-gnueabi" and 2865 "linux-musleabi" values possible. 2866 2867 :term:`HOST_PREFIX` 2868 Specifies the prefix for the cross-compile toolchain. :term:`HOST_PREFIX` 2869 is normally the same as :term:`TARGET_PREFIX`. 2870 2871 :term:`HOST_SYS` 2872 Specifies the system, including the architecture and the operating 2873 system, for which the build is occurring in the context of the 2874 current recipe. 2875 2876 The OpenEmbedded build system automatically sets this variable based 2877 on :term:`HOST_ARCH`, 2878 :term:`HOST_VENDOR`, and 2879 :term:`HOST_OS` variables. 2880 2881 .. note:: 2882 2883 You do not need to set the variable yourself. 2884 2885 Consider these two examples: 2886 2887 - Given a native recipe on a 32-bit x86 machine running Linux, the 2888 value is "i686-linux". 2889 2890 - Given a recipe being built for a little-endian MIPS target running 2891 Linux, the value might be "mipsel-linux". 2892 2893 :term:`HOST_VENDOR` 2894 Specifies the name of the vendor. :term:`HOST_VENDOR` is normally the 2895 same as :term:`TARGET_VENDOR`. 2896 2897 :term:`HOSTTOOLS` 2898 A space-separated list (filter) of tools on the build host that 2899 should be allowed to be called from within build tasks. Using this 2900 filter helps reduce the possibility of host contamination. If a tool 2901 specified in the value of :term:`HOSTTOOLS` is not found on the build 2902 host, the OpenEmbedded build system produces an error and the build 2903 is not started. 2904 2905 For additional information, see 2906 :term:`HOSTTOOLS_NONFATAL`. 2907 2908 :term:`HOSTTOOLS_NONFATAL` 2909 A space-separated list (filter) of tools on the build host that 2910 should be allowed to be called from within build tasks. Using this 2911 filter helps reduce the possibility of host contamination. Unlike 2912 :term:`HOSTTOOLS`, the OpenEmbedded build system 2913 does not produce an error if a tool specified in the value of 2914 :term:`HOSTTOOLS_NONFATAL` is not found on the build host. Thus, you can 2915 use :term:`HOSTTOOLS_NONFATAL` to filter optional host tools. 2916 2917 :term:`ICECC_CLASS_DISABLE` 2918 Identifies user classes that you do not want the Icecream distributed 2919 compile support to consider. This variable is used by the 2920 :ref:`icecc <ref-classes-icecc>` class. You set this variable in 2921 your ``local.conf`` file. 2922 2923 When you list classes using this variable, the recipes inheriting 2924 those classes will not benefit from distributed compilation across 2925 remote hosts. Instead they will be built locally. 2926 2927 :term:`ICECC_DISABLED` 2928 Disables or enables the ``icecc`` (Icecream) function. For more 2929 information on this function and best practices for using this 2930 variable, see the ":ref:`ref-classes-icecc`" 2931 section. 2932 2933 Setting this variable to "1" in your ``local.conf`` disables the 2934 function:: 2935 2936 ICECC_DISABLED ??= "1" 2937 2938 To enable the function, set the variable as follows:: 2939 2940 ICECC_DISABLED = "" 2941 2942 :term:`ICECC_ENV_EXEC` 2943 Points to the ``icecc-create-env`` script that you provide. This 2944 variable is used by the :ref:`icecc <ref-classes-icecc>` class. You 2945 set this variable in your ``local.conf`` file. 2946 2947 If you do not point to a script that you provide, the OpenEmbedded 2948 build system uses the default script provided by the 2949 ``icecc-create-env.bb`` recipe, which is a modified version and not 2950 the one that comes with ``icecc``. 2951 2952 :term:`ICECC_PARALLEL_MAKE` 2953 Extra options passed to the ``make`` command during the 2954 :ref:`ref-tasks-compile` task that specify parallel 2955 compilation. This variable usually takes the form of "-j x", where x 2956 represents the maximum number of parallel threads ``make`` can run. 2957 2958 .. note:: 2959 2960 The options passed affect builds on all enabled machines on the 2961 network, which are machines running the ``iceccd`` daemon. 2962 2963 If your enabled machines support multiple cores, coming up with the 2964 maximum number of parallel threads that gives you the best 2965 performance could take some experimentation since machine speed, 2966 network lag, available memory, and existing machine loads can all 2967 affect build time. Consequently, unlike the 2968 :term:`PARALLEL_MAKE` variable, there is no 2969 rule-of-thumb for setting :term:`ICECC_PARALLEL_MAKE` to achieve optimal 2970 performance. 2971 2972 If you do not set :term:`ICECC_PARALLEL_MAKE`, the build system does not 2973 use it (i.e. the system does not detect and assign the number of 2974 cores as is done with :term:`PARALLEL_MAKE`). 2975 2976 :term:`ICECC_PATH` 2977 The location of the ``icecc`` binary. You can set this variable in 2978 your ``local.conf`` file. If your ``local.conf`` file does not define 2979 this variable, the :ref:`icecc <ref-classes-icecc>` class attempts 2980 to define it by locating ``icecc`` using ``which``. 2981 2982 :term:`ICECC_RECIPE_DISABLE` 2983 Identifies user recipes that you do not want the Icecream distributed 2984 compile support to consider. This variable is used by the 2985 :ref:`icecc <ref-classes-icecc>` class. You set this variable in 2986 your ``local.conf`` file. 2987 2988 When you list recipes using this variable, you are excluding them 2989 from distributed compilation across remote hosts. Instead they will 2990 be built locally. 2991 2992 :term:`ICECC_RECIPE_ENABLE` 2993 Identifies user recipes that use an empty 2994 :term:`PARALLEL_MAKE` variable that you want to 2995 force remote distributed compilation on using the Icecream 2996 distributed compile support. This variable is used by the 2997 :ref:`icecc <ref-classes-icecc>` class. You set this variable in 2998 your ``local.conf`` file. 2999 3000 :term:`IMAGE_BASENAME` 3001 The base name of image output files. This variable defaults to the 3002 recipe name (``${``\ :term:`PN`\ ``}``). 3003 3004 :term:`IMAGE_BOOT_FILES` 3005 A space-separated list of files installed into the boot partition 3006 when preparing an image using the Wic tool with the 3007 ``bootimg-partition`` source plugin. By default, 3008 the files are 3009 installed under the same name as the source files. To change the 3010 installed name, separate it from the original name with a semi-colon 3011 (;). Source files need to be located in 3012 :term:`DEPLOY_DIR_IMAGE`. Here are two 3013 examples:: 3014 3015 IMAGE_BOOT_FILES = "u-boot.img uImage;kernel" 3016 IMAGE_BOOT_FILES = "u-boot.${UBOOT_SUFFIX} ${KERNEL_IMAGETYPE}" 3017 3018 Alternatively, source files can be picked up using a glob pattern. In 3019 this case, the destination file must have the same name as the base 3020 name of the source file path. To install files into a directory 3021 within the target location, pass its name after a semi-colon (;). 3022 Here are two examples:: 3023 3024 IMAGE_BOOT_FILES = "bcm2835-bootfiles/*" 3025 IMAGE_BOOT_FILES = "bcm2835-bootfiles/*;boot/" 3026 3027 The first example 3028 installs all files from ``${DEPLOY_DIR_IMAGE}/bcm2835-bootfiles`` 3029 into the root of the target partition. The second example installs 3030 the same files into a ``boot`` directory within the target partition. 3031 3032 You can find information on how to use the Wic tool in the 3033 ":ref:`dev-manual/common-tasks:creating partitioned images using wic`" 3034 section of the Yocto Project Development Tasks Manual. Reference 3035 material for Wic is located in the 3036 ":doc:`/ref-manual/kickstart`" chapter. 3037 3038 :term:`IMAGE_CLASSES` 3039 A list of classes that all images should inherit. You typically use 3040 this variable to specify the list of classes that register the 3041 different types of images the OpenEmbedded build system creates. 3042 3043 The default value for :term:`IMAGE_CLASSES` is ``image_types``. You can 3044 set this variable in your ``local.conf`` or in a distribution 3045 configuration file. 3046 3047 For more information, see ``meta/classes/image_types.bbclass`` in the 3048 :term:`Source Directory`. 3049 3050 :term:`IMAGE_CMD` 3051 Specifies the command to create the image file for a specific image 3052 type, which corresponds to the value set in 3053 :term:`IMAGE_FSTYPES`, (e.g. ``ext3``, 3054 ``btrfs``, and so forth). When setting this variable, you should use 3055 an override for the associated type. Here is an example:: 3056 3057 IMAGE_CMD:jffs2 = "mkfs.jffs2 --root=${IMAGE_ROOTFS} --faketime \ 3058 --output=${IMGDEPLOYDIR}/${IMAGE_NAME}${IMAGE_NAME_SUFFIX}.jffs2 \ 3059 ${EXTRA_IMAGECMD}" 3060 3061 You typically do not need to set this variable unless you are adding 3062 support for a new image type. For more examples on how to set this 3063 variable, see the :ref:`image_types <ref-classes-image_types>` 3064 class file, which is ``meta/classes/image_types.bbclass``. 3065 3066 :term:`IMAGE_DEVICE_TABLES` 3067 Specifies one or more files that contain custom device tables that 3068 are passed to the ``makedevs`` command as part of creating an image. 3069 These files list basic device nodes that should be created under 3070 ``/dev`` within the image. If :term:`IMAGE_DEVICE_TABLES` is not set, 3071 ``files/device_table-minimal.txt`` is used, which is located by 3072 :term:`BBPATH`. For details on how you should write 3073 device table files, see ``meta/files/device_table-minimal.txt`` as an 3074 example. 3075 3076 :term:`IMAGE_EFI_BOOT_FILES` 3077 A space-separated list of files installed into the boot partition 3078 when preparing an image using the Wic tool with the 3079 ``bootimg-efi`` source plugin. By default, 3080 the files are 3081 installed under the same name as the source files. To change the 3082 installed name, separate it from the original name with a semi-colon 3083 (;). Source files need to be located in 3084 :term:`DEPLOY_DIR_IMAGE`. Here are two 3085 examples:: 3086 3087 IMAGE_EFI_BOOT_FILES = "${KERNEL_IMAGETYPE};bz2" 3088 IMAGE_EFI_BOOT_FILES = "${KERNEL_IMAGETYPE} microcode.cpio" 3089 3090 Alternatively, source files can be picked up using a glob pattern. In 3091 this case, the destination file must have the same name as the base 3092 name of the source file path. To install files into a directory 3093 within the target location, pass its name after a semi-colon (;). 3094 Here are two examples:: 3095 3096 IMAGE_EFI_BOOT_FILES = "boot/loader/*" 3097 IMAGE_EFI_BOOT_FILES = "boot/loader/*;boot/" 3098 3099 The first example 3100 installs all files from ``${DEPLOY_DIR_IMAGE}/boot/loader/`` 3101 into the root of the target partition. The second example installs 3102 the same files into a ``boot`` directory within the target partition. 3103 3104 You can find information on how to use the Wic tool in the 3105 ":ref:`dev-manual/common-tasks:creating partitioned images using wic`" 3106 section of the Yocto Project Development Tasks Manual. Reference 3107 material for Wic is located in the 3108 ":doc:`/ref-manual/kickstart`" chapter. 3109 3110 :term:`IMAGE_FEATURES` 3111 The primary list of features to include in an image. Typically, you 3112 configure this variable in an image recipe. Although you can use this 3113 variable from your ``local.conf`` file, which is found in the 3114 :term:`Build Directory`, best practices dictate that you do 3115 not. 3116 3117 .. note:: 3118 3119 To enable extra features from outside the image recipe, use the 3120 :term:`EXTRA_IMAGE_FEATURES` variable. 3121 3122 For a list of image features that ships with the Yocto Project, see 3123 the ":ref:`ref-features-image`" section. 3124 3125 For an example that shows how to customize your image by using this 3126 variable, see the ":ref:`dev-manual/common-tasks:customizing images using custom \`\`image_features\`\` and \`\`extra_image_features\`\``" 3127 section in the Yocto Project Development Tasks Manual. 3128 3129 :term:`IMAGE_FSTYPES` 3130 Specifies the formats the OpenEmbedded build system uses during the 3131 build when creating the root filesystem. For example, setting 3132 :term:`IMAGE_FSTYPES` as follows causes the build system to create root 3133 filesystems using two formats: ``.ext3`` and ``.tar.bz2``:: 3134 3135 IMAGE_FSTYPES = "ext3 tar.bz2" 3136 3137 For the complete list of supported image formats from which you can 3138 choose, see :term:`IMAGE_TYPES`. 3139 3140 .. note:: 3141 3142 - If an image recipe uses the "inherit image" line and you are 3143 setting :term:`IMAGE_FSTYPES` inside the recipe, you must set 3144 :term:`IMAGE_FSTYPES` prior to using the "inherit image" line. 3145 3146 - Due to the way the OpenEmbedded build system processes this 3147 variable, you cannot update its contents by using ``:append`` 3148 or ``:prepend``. You must use the ``+=`` operator to add one or 3149 more options to the :term:`IMAGE_FSTYPES` variable. 3150 3151 :term:`IMAGE_INSTALL` 3152 Used by recipes to specify the packages to install into an image 3153 through the :ref:`image <ref-classes-image>` class. Use the 3154 :term:`IMAGE_INSTALL` variable with care to avoid ordering issues. 3155 3156 Image recipes set :term:`IMAGE_INSTALL` to specify the packages to 3157 install into an image through :ref:`ref-classes-image`. Additionally, 3158 there are "helper" classes such as the 3159 :ref:`core-image <ref-classes-core-image>` class which can 3160 take lists used with :term:`IMAGE_FEATURES` and turn them into 3161 auto-generated entries in :term:`IMAGE_INSTALL` in addition to its 3162 default contents. 3163 3164 When you use this variable, it is best to use it as follows:: 3165 3166 IMAGE_INSTALL:append = " package-name" 3167 3168 Be sure to include the space 3169 between the quotation character and the start of the package name or 3170 names. 3171 3172 .. note:: 3173 3174 - When working with a 3175 :ref:`core-image-minimal-initramfs <ref-manual/images:images>` 3176 image, do not use the :term:`IMAGE_INSTALL` variable to specify 3177 packages for installation. Instead, use the 3178 :term:`PACKAGE_INSTALL` variable, which 3179 allows the initial RAM filesystem (initramfs) recipe to use a 3180 fixed set of packages and not be affected by :term:`IMAGE_INSTALL`. 3181 For information on creating an initramfs, see the 3182 ":ref:`dev-manual/common-tasks:building an initial ram filesystem (initramfs) image`" 3183 section in the Yocto Project Development Tasks Manual. 3184 3185 - Using :term:`IMAGE_INSTALL` with the 3186 :ref:`+= <bitbake:bitbake-user-manual/bitbake-user-manual-metadata:appending (+=) and prepending (=+) with spaces>` 3187 BitBake operator within the ``/conf/local.conf`` file or from 3188 within an image recipe is not recommended. Use of this operator 3189 in these ways can cause ordering issues. Since 3190 :ref:`ref-classes-core-image` sets :term:`IMAGE_INSTALL` to a default 3191 value using the 3192 :ref:`?= <bitbake:bitbake-user-manual/bitbake-user-manual-metadata:setting a default value (?=)>` 3193 operator, using a ``+=`` operation against :term:`IMAGE_INSTALL` 3194 results in unexpected behavior when used within 3195 ``conf/local.conf``. Furthermore, the same operation from 3196 within an image recipe may or may not succeed depending on the 3197 specific situation. In both these cases, the behavior is 3198 contrary to how most users expect the ``+=`` operator to work. 3199 3200 :term:`IMAGE_LINGUAS` 3201 Specifies the list of locales to install into the image during the 3202 root filesystem construction process. The OpenEmbedded build system 3203 automatically splits locale files, which are used for localization, 3204 into separate packages. Setting the :term:`IMAGE_LINGUAS` variable 3205 ensures that any locale packages that correspond to packages already 3206 selected for installation into the image are also installed. Here is 3207 an example:: 3208 3209 IMAGE_LINGUAS = "pt-br de-de" 3210 3211 In this example, the build system ensures any Brazilian Portuguese 3212 and German locale files that correspond to packages in the image are 3213 installed (i.e. ``*-locale-pt-br`` and ``*-locale-de-de`` as well as 3214 ``*-locale-pt`` and ``*-locale-de``, since some software packages 3215 only provide locale files by language and not by country-specific 3216 language). 3217 3218 See the :term:`GLIBC_GENERATE_LOCALES` 3219 variable for information on generating GLIBC locales. 3220 3221 3222 :term:`IMAGE_LINK_NAME` 3223 The name of the output image symlink (which does not include 3224 the version part as :term:`IMAGE_NAME` does). The default value 3225 is derived using the :term:`IMAGE_BASENAME` and :term:`MACHINE` 3226 variables:: 3227 3228 IMAGE_LINK_NAME ?= "${IMAGE_BASENAME}-${MACHINE}" 3229 3230 3231 :term:`IMAGE_MANIFEST` 3232 The manifest file for the image. This file lists all the installed 3233 packages that make up the image. The file contains package 3234 information on a line-per-package basis as follows:: 3235 3236 packagename packagearch version 3237 3238 The :ref:`rootfs-postcommands <ref-classes-rootfs*>` class defines the manifest 3239 file as follows:: 3240 3241 IMAGE_MANIFEST ="${IMGDEPLOYDIR}/${IMAGE_NAME}${IMAGE_NAME_SUFFIX}.manifest" 3242 3243 The location is 3244 derived using the :term:`IMGDEPLOYDIR` 3245 and :term:`IMAGE_NAME` variables. You can find 3246 information on how the image is created in the ":ref:`overview-manual/concepts:image generation`" 3247 section in the Yocto Project Overview and Concepts Manual. 3248 3249 :term:`IMAGE_NAME` 3250 The name of the output image files minus the extension. This variable 3251 is derived using the :term:`IMAGE_BASENAME`, 3252 :term:`MACHINE`, and :term:`IMAGE_VERSION_SUFFIX` 3253 variables:: 3254 3255 IMAGE_NAME ?= "${IMAGE_BASENAME}-${MACHINE}${IMAGE_VERSION_SUFFIX}" 3256 3257 :term:`IMAGE_NAME_SUFFIX` 3258 Suffix used for the image output filename - defaults to ``".rootfs"`` 3259 to distinguish the image file from other files created during image 3260 building; however if this suffix is redundant or not desired you can 3261 clear the value of this variable (set the value to ""). For example, 3262 this is typically cleared in initramfs image recipes. 3263 3264 :term:`IMAGE_OVERHEAD_FACTOR` 3265 Defines a multiplier that the build system applies to the initial 3266 image size for cases when the multiplier times the returned disk 3267 usage value for the image is greater than the sum of 3268 :term:`IMAGE_ROOTFS_SIZE` and :term:`IMAGE_ROOTFS_EXTRA_SPACE`. The result of 3269 the multiplier applied to the initial image size creates free disk 3270 space in the image as overhead. By default, the build process uses a 3271 multiplier of 1.3 for this variable. This default value results in 3272 30% free disk space added to the image when this method is used to 3273 determine the final generated image size. You should be aware that 3274 post install scripts and the package management system uses disk 3275 space inside this overhead area. Consequently, the multiplier does 3276 not produce an image with all the theoretical free disk space. See 3277 :term:`IMAGE_ROOTFS_SIZE` for information on how the build system 3278 determines the overall image size. 3279 3280 The default 30% free disk space typically gives the image enough room 3281 to boot and allows for basic post installs while still leaving a 3282 small amount of free disk space. If 30% free space is inadequate, you 3283 can increase the default value. For example, the following setting 3284 gives you 50% free space added to the image:: 3285 3286 IMAGE_OVERHEAD_FACTOR = "1.5" 3287 3288 Alternatively, you can ensure a specific amount of free disk space is 3289 added to the image by using the :term:`IMAGE_ROOTFS_EXTRA_SPACE` 3290 variable. 3291 3292 :term:`IMAGE_PKGTYPE` 3293 Defines the package type (i.e. DEB, RPM, IPK, or TAR) used by the 3294 OpenEmbedded build system. The variable is defined appropriately by 3295 the :ref:`package_deb <ref-classes-package_deb>`, 3296 :ref:`package_rpm <ref-classes-package_rpm>`, 3297 :ref:`package_ipk <ref-classes-package_ipk>`, or 3298 :ref:`package_tar <ref-classes-package_tar>` class. 3299 3300 .. note:: 3301 3302 The ``package_tar`` class is broken and is not supported. It is 3303 recommended that you do not use it. 3304 3305 The :ref:`populate_sdk_* <ref-classes-populate-sdk-*>` and 3306 :ref:`image <ref-classes-image>` classes use the :term:`IMAGE_PKGTYPE` 3307 for packaging up images and SDKs. 3308 3309 You should not set the :term:`IMAGE_PKGTYPE` manually. Rather, the 3310 variable is set indirectly through the appropriate 3311 :ref:`package_* <ref-classes-package>` class using the 3312 :term:`PACKAGE_CLASSES` variable. The 3313 OpenEmbedded build system uses the first package type (e.g. DEB, RPM, 3314 or IPK) that appears with the variable 3315 3316 .. note:: 3317 3318 Files using the ``.tar`` format are never used as a substitute 3319 packaging format for DEB, RPM, and IPK formatted files for your image 3320 or SDK. 3321 3322 :term:`IMAGE_POSTPROCESS_COMMAND` 3323 Specifies a list of functions to call once the OpenEmbedded build 3324 system creates the final image output files. You can specify 3325 functions separated by semicolons:: 3326 3327 IMAGE_POSTPROCESS_COMMAND += "function; ... " 3328 3329 If you need to pass the root filesystem path to a command within the 3330 function, you can use ``${IMAGE_ROOTFS}``, which points to the 3331 directory that becomes the root filesystem image. See the 3332 :term:`IMAGE_ROOTFS` variable for more 3333 information. 3334 3335 :term:`IMAGE_PREPROCESS_COMMAND` 3336 Specifies a list of functions to call before the OpenEmbedded build 3337 system creates the final image output files. You can specify 3338 functions separated by semicolons:: 3339 3340 IMAGE_PREPROCESS_COMMAND += "function; ... " 3341 3342 If you need to pass the root filesystem path to a command within the 3343 function, you can use ``${IMAGE_ROOTFS}``, which points to the 3344 directory that becomes the root filesystem image. See the 3345 :term:`IMAGE_ROOTFS` variable for more 3346 information. 3347 3348 :term:`IMAGE_ROOTFS` 3349 The location of the root filesystem while it is under construction 3350 (i.e. during the :ref:`ref-tasks-rootfs` task). This 3351 variable is not configurable. Do not change it. 3352 3353 :term:`IMAGE_ROOTFS_ALIGNMENT` 3354 Specifies the alignment for the output image file in Kbytes. If the 3355 size of the image is not a multiple of this value, then the size is 3356 rounded up to the nearest multiple of the value. The default value is 3357 "1". See :term:`IMAGE_ROOTFS_SIZE` for 3358 additional information. 3359 3360 :term:`IMAGE_ROOTFS_EXTRA_SPACE` 3361 Defines additional free disk space created in the image in Kbytes. By 3362 default, this variable is set to "0". This free disk space is added 3363 to the image after the build system determines the image size as 3364 described in :term:`IMAGE_ROOTFS_SIZE`. 3365 3366 This variable is particularly useful when you want to ensure that a 3367 specific amount of free disk space is available on a device after an 3368 image is installed and running. For example, to be sure 5 Gbytes of 3369 free disk space is available, set the variable as follows:: 3370 3371 IMAGE_ROOTFS_EXTRA_SPACE = "5242880" 3372 3373 For example, the Yocto Project Build Appliance specifically requests 3374 40 Gbytes of extra space with the line:: 3375 3376 IMAGE_ROOTFS_EXTRA_SPACE = "41943040" 3377 3378 :term:`IMAGE_ROOTFS_SIZE` 3379 Defines the size in Kbytes for the generated image. The OpenEmbedded 3380 build system determines the final size for the generated image using 3381 an algorithm that takes into account the initial disk space used for 3382 the generated image, a requested size for the image, and requested 3383 additional free disk space to be added to the image. Programatically, 3384 the build system determines the final size of the generated image as 3385 follows:: 3386 3387 if (image-du * overhead) < rootfs-size: 3388 internal-rootfs-size = rootfs-size + xspace 3389 else: 3390 internal-rootfs-size = (image-du * overhead) + xspace 3391 where: 3392 image-du = Returned value of the du command on the image. 3393 overhead = IMAGE_OVERHEAD_FACTOR 3394 rootfs-size = IMAGE_ROOTFS_SIZE 3395 internal-rootfs-size = Initial root filesystem size before any modifications. 3396 xspace = IMAGE_ROOTFS_EXTRA_SPACE 3397 3398 See the :term:`IMAGE_OVERHEAD_FACTOR` 3399 and :term:`IMAGE_ROOTFS_EXTRA_SPACE` 3400 variables for related information. 3401 3402 :term:`IMAGE_TYPEDEP` 3403 Specifies a dependency from one image type on another. Here is an 3404 example from the :ref:`image-live <ref-classes-image-live>` class:: 3405 3406 IMAGE_TYPEDEP:live = "ext3" 3407 3408 In the previous example, the variable ensures that when "live" is 3409 listed with the :term:`IMAGE_FSTYPES` variable, 3410 the OpenEmbedded build system produces an ``ext3`` image first since 3411 one of the components of the live image is an ``ext3`` formatted 3412 partition containing the root filesystem. 3413 3414 :term:`IMAGE_TYPES` 3415 Specifies the complete list of supported image types by default: 3416 3417 - btrfs 3418 - container 3419 - cpio 3420 - cpio.gz 3421 - cpio.lz4 3422 - cpio.lzma 3423 - cpio.xz 3424 - cramfs 3425 - erofs 3426 - erofs-lz4 3427 - erofs-lz4hc 3428 - ext2 3429 - ext2.bz2 3430 - ext2.gz 3431 - ext2.lzma 3432 - ext3 3433 - ext3.gz 3434 - ext4 3435 - ext4.gz 3436 - f2fs 3437 - hddimg 3438 - iso 3439 - jffs2 3440 - jffs2.sum 3441 - multiubi 3442 - squashfs 3443 - squashfs-lz4 3444 - squashfs-lzo 3445 - squashfs-xz 3446 - tar 3447 - tar.bz2 3448 - tar.gz 3449 - tar.lz4 3450 - tar.xz 3451 - tar.zst 3452 - ubi 3453 - ubifs 3454 - wic 3455 - wic.bz2 3456 - wic.gz 3457 - wic.lzma 3458 3459 For more information about these types of images, see 3460 ``meta/classes/image_types*.bbclass`` in the :term:`Source Directory`. 3461 3462 :term:`IMAGE_VERSION_SUFFIX` 3463 Version suffix that is part of the default :term:`IMAGE_NAME` and 3464 :term:`KERNEL_ARTIFACT_NAME` values. 3465 Defaults to ``"-${DATETIME}"``, however you could set this to a 3466 version string that comes from your external build environment if 3467 desired, and this suffix would then be used consistently across 3468 the build artifacts. 3469 3470 :term:`IMGDEPLOYDIR` 3471 When inheriting the :ref:`image <ref-classes-image>` class directly or 3472 through the :ref:`core-image <ref-classes-core-image>` class, the 3473 :term:`IMGDEPLOYDIR` points to a temporary work area for deployed files 3474 that is set in the ``image`` class as follows:: 3475 3476 IMGDEPLOYDIR = "${WORKDIR}/deploy-${PN}-image-complete" 3477 3478 Recipes inheriting the ``image`` class should copy files to be 3479 deployed into :term:`IMGDEPLOYDIR`, and the class will take care of 3480 copying them into :term:`DEPLOY_DIR_IMAGE` afterwards. 3481 3482 :term:`INC_PR` 3483 Helps define the recipe revision for recipes that share a common 3484 ``include`` file. You can think of this variable as part of the 3485 recipe revision as set from within an include file. 3486 3487 Suppose, for example, you have a set of recipes that are used across 3488 several projects. And, within each of those recipes the revision (its 3489 :term:`PR` value) is set accordingly. In this case, when 3490 the revision of those recipes changes, the burden is on you to find 3491 all those recipes and be sure that they get changed to reflect the 3492 updated version of the recipe. In this scenario, it can get 3493 complicated when recipes that are used in many places and provide 3494 common functionality are upgraded to a new revision. 3495 3496 A more efficient way of dealing with this situation is to set the 3497 :term:`INC_PR` variable inside the ``include`` files that the recipes 3498 share and then expand the :term:`INC_PR` variable within the recipes to 3499 help define the recipe revision. 3500 3501 The following provides an example that shows how to use the 3502 :term:`INC_PR` variable given a common ``include`` file that defines the 3503 variable. Once the variable is defined in the ``include`` file, you 3504 can use the variable to set the :term:`PR` values in each recipe. You 3505 will notice that when you set a recipe's :term:`PR` you can provide more 3506 granular revisioning by appending values to the :term:`INC_PR` variable:: 3507 3508 recipes-graphics/xorg-font/xorg-font-common.inc:INC_PR = "r2" 3509 recipes-graphics/xorg-font/encodings_1.0.4.bb:PR = "${INC_PR}.1" 3510 recipes-graphics/xorg-font/font-util_1.3.0.bb:PR = "${INC_PR}.0" 3511 recipes-graphics/xorg-font/font-alias_1.0.3.bb:PR = "${INC_PR}.3" 3512 3513 The 3514 first line of the example establishes the baseline revision to be 3515 used for all recipes that use the ``include`` file. The remaining 3516 lines in the example are from individual recipes and show how the 3517 :term:`PR` value is set. 3518 3519 :term:`INCOMPATIBLE_LICENSE` 3520 Specifies a space-separated list of license names (as they would 3521 appear in :term:`LICENSE`) that should be excluded 3522 from the build. Recipes that provide no alternatives to listed 3523 incompatible licenses are not built. Packages that are individually 3524 licensed with the specified incompatible licenses will be deleted. 3525 3526 There is some support for wildcards in this variable's value, 3527 however it is restricted to specific licenses. Currently only 3528 these wildcards are allowed and expand as follows: 3529 3530 - ``AGPL-3.0*"``: ``AGPL-3.0-only``, ``AGPL-3.0-or-later`` 3531 - ``GPL-3.0*``: ``GPL-3.0-only``, ``GPL-3.0-or-later`` 3532 - ``LGPL-3.0*``: ``LGPL-3.0-only``, ``LGPL-3.0-or-later`` 3533 3534 .. note:: 3535 3536 This functionality is only regularly tested using the following 3537 setting:: 3538 3539 INCOMPATIBLE_LICENSE = "GPL-3.0* LGPL-3.0* AGPL-3.0*" 3540 3541 3542 Although you can use other settings, you might be required to 3543 remove dependencies on or provide alternatives to components that 3544 are required to produce a functional system image. 3545 3546 :term:`INHERIT` 3547 Causes the named class or classes to be inherited globally. Anonymous 3548 functions in the class or classes are not executed for the base 3549 configuration and in each individual recipe. The OpenEmbedded build 3550 system ignores changes to :term:`INHERIT` in individual recipes. 3551 3552 For more information on :term:`INHERIT`, see the 3553 :ref:`bitbake:bitbake-user-manual/bitbake-user-manual-metadata:\`\`inherit\`\` configuration directive`" 3554 section in the BitBake User Manual. 3555 3556 :term:`INHERIT_DISTRO` 3557 Lists classes that will be inherited at the distribution level. It is 3558 unlikely that you want to edit this variable. 3559 3560 The default value of the variable is set as follows in the 3561 ``meta/conf/distro/defaultsetup.conf`` file:: 3562 3563 INHERIT_DISTRO ?= "debian devshell sstate license" 3564 3565 :term:`INHIBIT_DEFAULT_DEPS` 3566 Prevents the default dependencies, namely the C compiler and standard 3567 C library (libc), from being added to :term:`DEPENDS`. 3568 This variable is usually used within recipes that do not require any 3569 compilation using the C compiler. 3570 3571 Set the variable to "1" to prevent the default dependencies from 3572 being added. 3573 3574 :term:`INHIBIT_PACKAGE_DEBUG_SPLIT` 3575 Prevents the OpenEmbedded build system from splitting out debug 3576 information during packaging. By default, the build system splits out 3577 debugging information during the 3578 :ref:`ref-tasks-package` task. For more information on 3579 how debug information is split out, see the 3580 :term:`PACKAGE_DEBUG_SPLIT_STYLE` 3581 variable. 3582 3583 To prevent the build system from splitting out debug information 3584 during packaging, set the :term:`INHIBIT_PACKAGE_DEBUG_SPLIT` variable as 3585 follows:: 3586 3587 INHIBIT_PACKAGE_DEBUG_SPLIT = "1" 3588 3589 :term:`INHIBIT_PACKAGE_STRIP` 3590 If set to "1", causes the build to not strip binaries in resulting 3591 packages and prevents the ``-dbg`` package from containing the source 3592 files. 3593 3594 By default, the OpenEmbedded build system strips binaries and puts 3595 the debugging symbols into ``${``\ :term:`PN`\ ``}-dbg``. 3596 Consequently, you should not set :term:`INHIBIT_PACKAGE_STRIP` when you 3597 plan to debug in general. 3598 3599 :term:`INHIBIT_SYSROOT_STRIP` 3600 If set to "1", causes the build to not strip binaries in the 3601 resulting sysroot. 3602 3603 By default, the OpenEmbedded build system strips binaries in the 3604 resulting sysroot. When you specifically set the 3605 :term:`INHIBIT_SYSROOT_STRIP` variable to "1" in your recipe, you inhibit 3606 this stripping. 3607 3608 If you want to use this variable, include the 3609 :ref:`staging <ref-classes-staging>` class. This class uses a 3610 ``sys_strip()`` function to test for the variable and acts 3611 accordingly. 3612 3613 .. note:: 3614 3615 Use of the :term:`INHIBIT_SYSROOT_STRIP` variable occurs in rare and 3616 special circumstances. For example, suppose you are building 3617 bare-metal firmware by using an external GCC toolchain. Furthermore, 3618 even if the toolchain's binaries are strippable, there are other files 3619 needed for the build that are not strippable. 3620 3621 :term:`INITRAMFS_DEPLOY_DIR_IMAGE` 3622 Indicates the deploy directory used by ``do_bundle_initramfs`` where the 3623 :term:`INITRAMFS_IMAGE` will be fetched from. 3624 This variable is set by default to ``${DEPLOY_DIR_IMAGE}`` in the 3625 :ref:`kernel <ref-classes-kernel>` class and it's only meant to be changed 3626 when building an initramfs image from a separate multiconfig via :term:`INITRAMFS_MULTICONFIG`. 3627 3628 :term:`INITRAMFS_FSTYPES` 3629 Defines the format for the output image of an initial RAM filesystem 3630 (initramfs), which is used during boot. Supported formats are the 3631 same as those supported by the 3632 :term:`IMAGE_FSTYPES` variable. 3633 3634 The default value of this variable, which is set in the 3635 ``meta/conf/bitbake.conf`` configuration file in the 3636 :term:`Source Directory`, is "cpio.gz". The Linux kernel's 3637 initramfs mechanism, as opposed to the initial RAM filesystem 3638 `initrd <https://en.wikipedia.org/wiki/Initrd>`__ mechanism, expects 3639 an optionally compressed cpio archive. 3640 3641 :term:`INITRAMFS_IMAGE` 3642 Specifies the :term:`PROVIDES` name of an image 3643 recipe that is used to build an initial RAM filesystem (initramfs) 3644 image. In other words, the :term:`INITRAMFS_IMAGE` variable causes an 3645 additional recipe to be built as a dependency to whatever root 3646 filesystem recipe you might be using (e.g. ``core-image-sato``). The 3647 initramfs image recipe you provide should set 3648 :term:`IMAGE_FSTYPES` to 3649 :term:`INITRAMFS_FSTYPES`. 3650 3651 An initramfs image provides a temporary root filesystem used for 3652 early system initialization (e.g. loading of modules needed to locate 3653 and mount the "real" root filesystem). 3654 3655 .. note:: 3656 3657 See the ``meta/recipes-core/images/core-image-minimal-initramfs.bb`` 3658 recipe in the :term:`Source Directory` 3659 for an example initramfs recipe. To select this sample recipe as 3660 the one built to provide the initramfs image, set :term:`INITRAMFS_IMAGE` 3661 to "core-image-minimal-initramfs". 3662 3663 You can also find more information by referencing the 3664 ``meta-poky/conf/local.conf.sample.extended`` configuration file in 3665 the Source Directory, the :ref:`image <ref-classes-image>` class, 3666 and the :ref:`kernel <ref-classes-kernel>` class to see how to use 3667 the :term:`INITRAMFS_IMAGE` variable. 3668 3669 If :term:`INITRAMFS_IMAGE` is empty, which is the default, then no 3670 initramfs image is built. 3671 3672 For more information, you can also see the 3673 :term:`INITRAMFS_IMAGE_BUNDLE` 3674 variable, which allows the generated image to be bundled inside the 3675 kernel image. Additionally, for information on creating an initramfs 3676 image, see the ":ref:`dev-manual/common-tasks:building an initial ram filesystem (initramfs) image`" section 3677 in the Yocto Project Development Tasks Manual. 3678 3679 :term:`INITRAMFS_IMAGE_BUNDLE` 3680 Controls whether or not the image recipe specified by 3681 :term:`INITRAMFS_IMAGE` is run through an 3682 extra pass 3683 (:ref:`ref-tasks-bundle_initramfs`) during 3684 kernel compilation in order to build a single binary that contains 3685 both the kernel image and the initial RAM filesystem (initramfs) 3686 image. This makes use of the 3687 :term:`CONFIG_INITRAMFS_SOURCE` kernel 3688 feature. 3689 3690 .. note:: 3691 3692 Bundling the initramfs with the kernel conflates the code in the 3693 initramfs with the GPLv2 licensed Linux kernel binary. Thus only GPLv2 3694 compatible software may be part of a bundled initramfs. 3695 3696 .. note:: 3697 3698 Using an extra compilation pass to bundle the initramfs avoids a 3699 circular dependency between the kernel recipe and the initramfs 3700 recipe should the initramfs include kernel modules. Should that be 3701 the case, the initramfs recipe depends on the kernel for the 3702 kernel modules, and the kernel depends on the initramfs recipe 3703 since the initramfs is bundled inside the kernel image. 3704 3705 The combined binary is deposited into the ``tmp/deploy`` directory, 3706 which is part of the :term:`Build Directory`. 3707 3708 Setting the variable to "1" in a configuration file causes the 3709 OpenEmbedded build system to generate a kernel image with the 3710 initramfs specified in :term:`INITRAMFS_IMAGE` bundled within:: 3711 3712 INITRAMFS_IMAGE_BUNDLE = "1" 3713 3714 By default, the 3715 :ref:`kernel <ref-classes-kernel>` class sets this variable to a 3716 null string as follows:: 3717 3718 INITRAMFS_IMAGE_BUNDLE ?= "" 3719 3720 .. note:: 3721 3722 You must set the :term:`INITRAMFS_IMAGE_BUNDLE` variable in a 3723 configuration file. You cannot set the variable in a recipe file. 3724 3725 See the 3726 :yocto_git:`local.conf.sample.extended </poky/tree/meta-poky/conf/local.conf.sample.extended>` 3727 file for additional information. Also, for information on creating an 3728 initramfs, see the ":ref:`dev-manual/common-tasks:building an initial ram filesystem (initramfs) image`" section 3729 in the Yocto Project Development Tasks Manual. 3730 3731 :term:`INITRAMFS_LINK_NAME` 3732 The link name of the initial RAM filesystem image. This variable is 3733 set in the ``meta/classes/kernel-artifact-names.bbclass`` file as 3734 follows:: 3735 3736 INITRAMFS_LINK_NAME ?= "initramfs-${KERNEL_ARTIFACT_LINK_NAME}" 3737 3738 The value of the 3739 ``KERNEL_ARTIFACT_LINK_NAME`` variable, which is set in the same 3740 file, has the following value:: 3741 3742 KERNEL_ARTIFACT_LINK_NAME ?= "${MACHINE}" 3743 3744 See the :term:`MACHINE` variable for additional 3745 information. 3746 3747 :term:`INITRAMFS_MULTICONFIG` 3748 Defines the multiconfig to create a multiconfig dependency to be used by the :ref:`kernel <ref-classes-kernel>` class. 3749 3750 This allows the kernel to bundle an :term:`INITRAMFS_IMAGE` coming from 3751 a separate multiconfig, this is meant to be used in addition to :term:`INITRAMFS_DEPLOY_DIR_IMAGE`. 3752 3753 For more information on how to bundle an initramfs image from a separate 3754 multiconfig see the ":ref:`dev-manual/common-tasks:Bundling an Initramfs Image From a Separate Multiconfig`" 3755 section in the Yocto Project Development Tasks Manual. 3756 3757 :term:`INITRAMFS_NAME` 3758 The base name of the initial RAM filesystem image. This variable is 3759 set in the ``meta/classes/kernel-artifact-names.bbclass`` file as 3760 follows:: 3761 3762 INITRAMFS_NAME ?= "initramfs-${KERNEL_ARTIFACT_NAME}" 3763 3764 The value of the :term:`KERNEL_ARTIFACT_NAME` 3765 variable, which is set in the same file, has the following value:: 3766 3767 KERNEL_ARTIFACT_NAME ?= "${PKGE}-${PKGV}-${PKGR}-${MACHINE}${IMAGE_VERSION_SUFFIX}" 3768 3769 :term:`INITRD` 3770 Indicates list of filesystem images to concatenate and use as an 3771 initial RAM disk (``initrd``). 3772 3773 The :term:`INITRD` variable is an optional variable used with the 3774 :ref:`image-live <ref-classes-image-live>` class. 3775 3776 :term:`INITRD_IMAGE` 3777 When building a "live" bootable image (i.e. when 3778 :term:`IMAGE_FSTYPES` contains "live"), 3779 :term:`INITRD_IMAGE` specifies the image recipe that should be built to 3780 provide the initial RAM disk image. The default value is 3781 "core-image-minimal-initramfs". 3782 3783 See the :ref:`image-live <ref-classes-image-live>` class for more 3784 information. 3785 3786 :term:`INITSCRIPT_NAME` 3787 The filename of the initialization script as installed to 3788 ``${sysconfdir}/init.d``. 3789 3790 This variable is used in recipes when using :ref:`ref-classes-update-rc.d`. 3791 The variable is mandatory. 3792 3793 :term:`INITSCRIPT_PACKAGES` 3794 A list of the packages that contain initscripts. If multiple packages 3795 are specified, you need to append the package name to the other 3796 ``INITSCRIPT_*`` as an override. 3797 3798 This variable is used in recipes when using :ref:`ref-classes-update-rc.d`. 3799 The variable is optional and defaults to the :term:`PN` 3800 variable. 3801 3802 :term:`INITSCRIPT_PARAMS` 3803 Specifies the options to pass to ``update-rc.d``. Here is an example:: 3804 3805 INITSCRIPT_PARAMS = "start 99 5 2 . stop 20 0 1 6 ." 3806 3807 In this example, the script has a runlevel of 99, starts the script 3808 in initlevels 2 and 5, and stops the script in levels 0, 1 and 6. 3809 3810 The variable's default value is "defaults", which is set in the 3811 :ref:`update-rc.d <ref-classes-update-rc.d>` class. 3812 3813 The value in :term:`INITSCRIPT_PARAMS` is passed through to the 3814 ``update-rc.d`` command. For more information on valid parameters, 3815 please see the ``update-rc.d`` manual page at 3816 https://manpages.debian.org/buster/init-system-helpers/update-rc.d.8.en.html 3817 3818 :term:`INSANE_SKIP` 3819 Specifies the QA checks to skip for a specific package within a 3820 recipe. For example, to skip the check for symbolic link ``.so`` 3821 files in the main package of a recipe, add the following to the 3822 recipe. The package name override must be used, which in this example 3823 is ``${PN}``:: 3824 3825 INSANE_SKIP:${PN} += "dev-so" 3826 3827 See the ":ref:`ref-classes-insane`" section for a 3828 list of the valid QA checks you can specify using this variable. 3829 3830 :term:`INSTALL_TIMEZONE_FILE` 3831 By default, the ``tzdata`` recipe packages an ``/etc/timezone`` file. 3832 Set the :term:`INSTALL_TIMEZONE_FILE` variable to "0" at the 3833 configuration level to disable this behavior. 3834 3835 :term:`IPK_FEED_URIS` 3836 When the IPK backend is in use and package management is enabled on 3837 the target, you can use this variable to set up ``opkg`` in the 3838 target image to point to package feeds on a nominated server. Once 3839 the feed is established, you can perform installations or upgrades 3840 using the package manager at runtime. 3841 3842 :term:`KARCH` 3843 Defines the kernel architecture used when assembling the 3844 configuration. Architectures supported for this release are: 3845 3846 - powerpc 3847 - i386 3848 - x86_64 3849 - arm 3850 - qemu 3851 - mips 3852 3853 You define the :term:`KARCH` variable in the :ref:`kernel-dev/advanced:bsp descriptions`. 3854 3855 :term:`KBRANCH` 3856 A regular expression used by the build process to explicitly identify 3857 the kernel branch that is validated, patched, and configured during a 3858 build. You must set this variable to ensure the exact kernel branch 3859 you want is being used by the build process. 3860 3861 Values for this variable are set in the kernel's recipe file and the 3862 kernel's append file. For example, if you are using the 3863 ``linux-yocto_4.12`` kernel, the kernel recipe file is the 3864 ``meta/recipes-kernel/linux/linux-yocto_4.12.bb`` file. :term:`KBRANCH` 3865 is set as follows in that kernel recipe file:: 3866 3867 KBRANCH ?= "standard/base" 3868 3869 This variable is also used from the kernel's append file to identify 3870 the kernel branch specific to a particular machine or target 3871 hardware. Continuing with the previous kernel example, the kernel's 3872 append file (i.e. ``linux-yocto_4.12.bbappend``) is located in the 3873 BSP layer for a given machine. For example, the append file for the 3874 Beaglebone, EdgeRouter, and generic versions of both 32 and 64-bit IA 3875 machines (``meta-yocto-bsp``) is named 3876 ``meta-yocto-bsp/recipes-kernel/linux/linux-yocto_4.12.bbappend``. 3877 Here are the related statements from that append file:: 3878 3879 KBRANCH:genericx86 = "standard/base" 3880 KBRANCH:genericx86-64 = "standard/base" 3881 KBRANCH:edgerouter = "standard/edgerouter" 3882 KBRANCH:beaglebone = "standard/beaglebone" 3883 3884 The :term:`KBRANCH` statements 3885 identify the kernel branch to use when building for each supported 3886 BSP. 3887 3888 :term:`KBUILD_DEFCONFIG` 3889 When used with the :ref:`kernel-yocto <ref-classes-kernel-yocto>` 3890 class, specifies an "in-tree" kernel configuration file for use 3891 during a kernel build. 3892 3893 Typically, when using a ``defconfig`` to configure a kernel during a 3894 build, you place the file in your layer in the same manner as you 3895 would place patch files and configuration fragment files (i.e. 3896 "out-of-tree"). However, if you want to use a ``defconfig`` file that 3897 is part of the kernel tree (i.e. "in-tree"), you can use the 3898 :term:`KBUILD_DEFCONFIG` variable and append the 3899 :term:`KMACHINE` variable to point to the 3900 ``defconfig`` file. 3901 3902 To use the variable, set it in the append file for your kernel recipe 3903 using the following form:: 3904 3905 KBUILD_DEFCONFIG_KMACHINE ?= defconfig_file 3906 3907 Here is an example from a "raspberrypi2" :term:`KMACHINE` build that uses 3908 a ``defconfig`` file named "bcm2709_defconfig":: 3909 3910 KBUILD_DEFCONFIG:raspberrypi2 = "bcm2709_defconfig" 3911 3912 As an alternative, you can use the following within your append file:: 3913 3914 KBUILD_DEFCONFIG:pn-linux-yocto ?= "defconfig_file" 3915 3916 For more 3917 information on how to use the :term:`KBUILD_DEFCONFIG` variable, see the 3918 ":ref:`kernel-dev/common:using an "in-tree" \`\`defconfig\`\` file`" 3919 section in the Yocto Project Linux Kernel Development Manual. 3920 3921 :term:`KCONFIG_MODE` 3922 When used with the :ref:`kernel-yocto <ref-classes-kernel-yocto>` 3923 class, specifies the kernel configuration values to use for options 3924 not specified in the provided ``defconfig`` file. Valid options are:: 3925 3926 KCONFIG_MODE = "alldefconfig" 3927 KCONFIG_MODE = "allnoconfig" 3928 3929 In ``alldefconfig`` mode the options not explicitly specified will be 3930 assigned their Kconfig default value. In ``allnoconfig`` mode the 3931 options not explicitly specified will be disabled in the kernel 3932 config. 3933 3934 In case :term:`KCONFIG_MODE` is not set the behaviour will depend on where 3935 the ``defconfig`` file is coming from. An "in-tree" ``defconfig`` file 3936 will be handled in ``alldefconfig`` mode, a ``defconfig`` file placed 3937 in ``${WORKDIR}`` through a meta-layer will be handled in 3938 ``allnoconfig`` mode. 3939 3940 An "in-tree" ``defconfig`` file can be selected via the 3941 :term:`KBUILD_DEFCONFIG` variable. :term:`KCONFIG_MODE` does not need to 3942 be explicitly set. 3943 3944 A ``defconfig`` file compatible with ``allnoconfig`` mode can be 3945 generated by copying the ``.config`` file from a working Linux kernel 3946 build, renaming it to ``defconfig`` and placing it into the Linux 3947 kernel ``${WORKDIR}`` through your meta-layer. :term:`KCONFIG_MODE` does 3948 not need to be explicitly set. 3949 3950 A ``defconfig`` file compatible with ``alldefconfig`` mode can be 3951 generated using the 3952 :ref:`ref-tasks-savedefconfig` 3953 task and placed into the Linux kernel ``${WORKDIR}`` through your 3954 meta-layer. Explicitely set :term:`KCONFIG_MODE`:: 3955 3956 KCONFIG_MODE = "alldefconfig" 3957 3958 3959 :term:`KERNEL_ALT_IMAGETYPE` 3960 Specifies an alternate kernel image type for creation in addition to 3961 the kernel image type specified using the 3962 :term:`KERNEL_IMAGETYPE` variable. 3963 3964 :term:`KERNEL_ARTIFACT_NAME` 3965 Specifies the name of all of the build artifacts. You can change the 3966 name of the artifacts by changing the :term:`KERNEL_ARTIFACT_NAME` 3967 variable. 3968 3969 The value of :term:`KERNEL_ARTIFACT_NAME`, which is set in the 3970 ``meta/classes/kernel-artifact-names.bbclass`` file, has the 3971 following default value:: 3972 3973 KERNEL_ARTIFACT_NAME ?= "${PKGE}-${PKGV}-${PKGR}-${MACHINE}${IMAGE_VERSION_SUFFIX}" 3974 3975 See the :term:`PKGE`, :term:`PKGV`, :term:`PKGR`, :term:`MACHINE` 3976 and :term:`IMAGE_VERSION_SUFFIX` variables for additional information. 3977 3978 :term:`KERNEL_CLASSES` 3979 A list of classes defining kernel image types that the 3980 :ref:`kernel <ref-classes-kernel>` class should inherit. You 3981 typically append this variable to enable extended image types. An 3982 example is the "kernel-fitimage", which enables fitImage support and 3983 resides in ``meta/classes/kernel-fitimage.bbclass``. You can register 3984 custom kernel image types with the :ref:`kernel <ref-classes-kernel>` class using this 3985 variable. 3986 3987 :term:`KERNEL_DEBUG_TIMESTAMPS` 3988 If set to "1", enables timestamping functionality during building 3989 the kernel. The default is "0" to disable this for reproducibility 3990 reasons. 3991 3992 :term:`KERNEL_DEVICETREE` 3993 Specifies the name of the generated Linux kernel device tree (i.e. 3994 the ``.dtb``) file. 3995 3996 .. note:: 3997 3998 There is legacy support for specifying the full path to the device 3999 tree. However, providing just the ``.dtb`` file is preferred. 4000 4001 In order to use this variable, the 4002 :ref:`kernel-devicetree <ref-classes-kernel-devicetree>` class must 4003 be inherited. 4004 4005 :term:`KERNEL_DTB_LINK_NAME` 4006 The link name of the kernel device tree binary (DTB). This variable 4007 is set in the ``meta/classes/kernel-artifact-names.bbclass`` file as 4008 follows:: 4009 4010 KERNEL_DTB_LINK_NAME ?= "${KERNEL_ARTIFACT_LINK_NAME}" 4011 4012 The 4013 value of the ``KERNEL_ARTIFACT_LINK_NAME`` variable, which is set in 4014 the same file, has the following value:: 4015 4016 KERNEL_ARTIFACT_LINK_NAME ?= "${MACHINE}" 4017 4018 See the :term:`MACHINE` variable for additional 4019 information. 4020 4021 :term:`KERNEL_DTB_NAME` 4022 The base name of the kernel device tree binary (DTB). This variable 4023 is set in the ``meta/classes/kernel-artifact-names.bbclass`` file as 4024 follows:: 4025 4026 KERNEL_DTB_NAME ?= "${KERNEL_ARTIFACT_NAME}" 4027 4028 The value of the :term:`KERNEL_ARTIFACT_NAME` 4029 variable, which is set in the same file, has the following value:: 4030 4031 KERNEL_ARTIFACT_NAME ?= "${PKGE}-${PKGV}-${PKGR}-${MACHINE}${IMAGE_VERSION_SUFFIX}" 4032 4033 :term:`KERNEL_DTC_FLAGS` 4034 Specifies the ``dtc`` flags that are passed to the Linux kernel build 4035 system when generating the device trees (via ``DTC_FLAGS`` environment 4036 variable). 4037 4038 In order to use this variable, the 4039 :ref:`kernel-devicetree <ref-classes-kernel-devicetree>` class must 4040 be inherited. 4041 4042 :term:`KERNEL_EXTRA_ARGS` 4043 Specifies additional ``make`` command-line arguments the OpenEmbedded 4044 build system passes on when compiling the kernel. 4045 4046 :term:`KERNEL_FEATURES` 4047 Includes additional kernel metadata. In the OpenEmbedded build 4048 system, the default Board Support Packages (BSPs) 4049 :term:`Metadata` is provided through the 4050 :term:`KMACHINE` and :term:`KBRANCH` 4051 variables. You can use the :term:`KERNEL_FEATURES` variable from within 4052 the kernel recipe or kernel append file to further add metadata for 4053 all BSPs or specific BSPs. 4054 4055 The metadata you add through this variable includes config fragments 4056 and features descriptions, which usually includes patches as well as 4057 config fragments. You typically override the :term:`KERNEL_FEATURES` 4058 variable for a specific machine. In this way, you can provide 4059 validated, but optional, sets of kernel configurations and features. 4060 4061 For example, the following example from the ``linux-yocto-rt_4.12`` 4062 kernel recipe adds "netfilter" and "taskstats" features to all BSPs 4063 as well as "virtio" configurations to all QEMU machines. The last two 4064 statements add specific configurations to targeted machine types:: 4065 4066 KERNEL_EXTRA_FEATURES ?= "features/netfilter/netfilter.scc features/taskstats/taskstats.scc" 4067 KERNEL_FEATURES:append = " ${KERNEL_EXTRA_FEATURES}" 4068 KERNEL_FEATURES:append:qemuall = " cfg/virtio.scc" 4069 KERNEL_FEATURES:append:qemux86 = " cfg/sound.scc cfg/paravirt_kvm.scc" 4070 KERNEL_FEATURES:append:qemux86-64 = " cfg/sound.scc" 4071 4072 :term:`KERNEL_FIT_LINK_NAME` 4073 The link name of the kernel flattened image tree (FIT) image. This 4074 variable is set in the ``meta/classes/kernel-artifact-names.bbclass`` 4075 file as follows:: 4076 4077 KERNEL_FIT_LINK_NAME ?= "${KERNEL_ARTIFACT_LINK_NAME}" 4078 4079 The value of the 4080 ``KERNEL_ARTIFACT_LINK_NAME`` variable, which is set in the same 4081 file, has the following value:: 4082 4083 KERNEL_ARTIFACT_LINK_NAME ?= "${MACHINE}" 4084 4085 See the :term:`MACHINE` variable for additional 4086 information. 4087 4088 :term:`KERNEL_FIT_NAME` 4089 The base name of the kernel flattened image tree (FIT) image. This 4090 variable is set in the ``meta/classes/kernel-artifact-names.bbclass`` 4091 file as follows:: 4092 4093 KERNEL_FIT_NAME ?= "${KERNEL_ARTIFACT_NAME}" 4094 4095 The value of the :term:`KERNEL_ARTIFACT_NAME` 4096 variable, which is set in the same file, has the following value:: 4097 4098 KERNEL_ARTIFACT_NAME ?= "${PKGE}-${PKGV}-${PKGR}-${MACHINE}${IMAGE_VERSION_SUFFIX}" 4099 4100 :term:`KERNEL_IMAGE_LINK_NAME` 4101 The link name for the kernel image. This variable is set in the 4102 ``meta/classes/kernel-artifact-names.bbclass`` file as follows:: 4103 4104 KERNEL_IMAGE_LINK_NAME ?= "${KERNEL_ARTIFACT_LINK_NAME}" 4105 4106 The value of 4107 the ``KERNEL_ARTIFACT_LINK_NAME`` variable, which is set in the same 4108 file, has the following value:: 4109 4110 KERNEL_ARTIFACT_LINK_NAME ?= "${MACHINE}" 4111 4112 See the :term:`MACHINE` variable for additional 4113 information. 4114 4115 :term:`KERNEL_IMAGE_MAXSIZE` 4116 Specifies the maximum size of the kernel image file in kilobytes. If 4117 :term:`KERNEL_IMAGE_MAXSIZE` is set, the size of the kernel image file is 4118 checked against the set value during the 4119 :ref:`ref-tasks-sizecheck` task. The task fails if 4120 the kernel image file is larger than the setting. 4121 4122 :term:`KERNEL_IMAGE_MAXSIZE` is useful for target devices that have a 4123 limited amount of space in which the kernel image must be stored. 4124 4125 By default, this variable is not set, which means the size of the 4126 kernel image is not checked. 4127 4128 :term:`KERNEL_IMAGE_NAME` 4129 The base name of the kernel image. This variable is set in the 4130 ``meta/classes/kernel-artifact-names.bbclass`` file as follows:: 4131 4132 KERNEL_IMAGE_NAME ?= "${KERNEL_ARTIFACT_NAME}" 4133 4134 The value of the 4135 :term:`KERNEL_ARTIFACT_NAME` variable, 4136 which is set in the same file, has the following value:: 4137 4138 KERNEL_ARTIFACT_NAME ?= "${PKGE}-${PKGV}-${PKGR}-${MACHINE}${IMAGE_VERSION_SUFFIX}" 4139 4140 :term:`KERNEL_IMAGETYPE` 4141 The type of kernel to build for a device, usually set by the machine 4142 configuration files and defaults to "zImage". This variable is used 4143 when building the kernel and is passed to ``make`` as the target to 4144 build. 4145 4146 If you want to build an alternate kernel image type in addition to that 4147 specified by :term:`KERNEL_IMAGETYPE`, use the :term:`KERNEL_ALT_IMAGETYPE` 4148 variable. 4149 4150 :term:`KERNEL_MODULE_AUTOLOAD` 4151 Lists kernel modules that need to be auto-loaded during boot. 4152 4153 .. note:: 4154 4155 This variable replaces the deprecated :term:`module_autoload` 4156 variable. 4157 4158 You can use the :term:`KERNEL_MODULE_AUTOLOAD` variable anywhere that it 4159 can be recognized by the kernel recipe or by an out-of-tree kernel 4160 module recipe (e.g. a machine configuration file, a distribution 4161 configuration file, an append file for the recipe, or the recipe 4162 itself). 4163 4164 Specify it as follows:: 4165 4166 KERNEL_MODULE_AUTOLOAD += "module_name1 module_name2 module_name3" 4167 4168 Including :term:`KERNEL_MODULE_AUTOLOAD` causes the OpenEmbedded build 4169 system to populate the ``/etc/modules-load.d/modname.conf`` file with 4170 the list of modules to be auto-loaded on boot. The modules appear 4171 one-per-line in the file. Here is an example of the most common use 4172 case:: 4173 4174 KERNEL_MODULE_AUTOLOAD += "module_name" 4175 4176 For information on how to populate the ``modname.conf`` file with 4177 ``modprobe.d`` syntax lines, see the :term:`KERNEL_MODULE_PROBECONF` variable. 4178 4179 :term:`KERNEL_MODULE_PROBECONF` 4180 Provides a list of modules for which the OpenEmbedded build system 4181 expects to find ``module_conf_``\ modname values that specify 4182 configuration for each of the modules. For information on how to 4183 provide those module configurations, see the 4184 :term:`module_conf_* <module_conf>` variable. 4185 4186 :term:`KERNEL_PATH` 4187 The location of the kernel sources. This variable is set to the value 4188 of the :term:`STAGING_KERNEL_DIR` within 4189 the :ref:`module <ref-classes-module>` class. For information on 4190 how this variable is used, see the 4191 ":ref:`kernel-dev/common:incorporating out-of-tree modules`" 4192 section in the Yocto Project Linux Kernel Development Manual. 4193 4194 To help maximize compatibility with out-of-tree drivers used to build 4195 modules, the OpenEmbedded build system also recognizes and uses the 4196 :term:`KERNEL_SRC` variable, which is identical to 4197 the :term:`KERNEL_PATH` variable. Both variables are common variables 4198 used by external Makefiles to point to the kernel source directory. 4199 4200 :term:`KERNEL_SRC` 4201 The location of the kernel sources. This variable is set to the value 4202 of the :term:`STAGING_KERNEL_DIR` within 4203 the :ref:`module <ref-classes-module>` class. For information on 4204 how this variable is used, see the 4205 ":ref:`kernel-dev/common:incorporating out-of-tree modules`" 4206 section in the Yocto Project Linux Kernel Development Manual. 4207 4208 To help maximize compatibility with out-of-tree drivers used to build 4209 modules, the OpenEmbedded build system also recognizes and uses the 4210 :term:`KERNEL_PATH` variable, which is identical 4211 to the :term:`KERNEL_SRC` variable. Both variables are common variables 4212 used by external Makefiles to point to the kernel source directory. 4213 4214 :term:`KERNEL_VERSION` 4215 Specifies the version of the kernel as extracted from ``version.h`` 4216 or ``utsrelease.h`` within the kernel sources. Effects of setting 4217 this variable do not take effect until the kernel has been 4218 configured. Consequently, attempting to refer to this variable in 4219 contexts prior to configuration will not work. 4220 4221 :term:`KERNELDEPMODDEPEND` 4222 Specifies whether the data referenced through 4223 :term:`PKGDATA_DIR` is needed or not. 4224 :term:`KERNELDEPMODDEPEND` does not control whether or not that data 4225 exists, but simply whether or not it is used. If you do not need to 4226 use the data, set the :term:`KERNELDEPMODDEPEND` variable in your 4227 ``initramfs`` recipe. Setting the variable there when the data is not 4228 needed avoids a potential dependency loop. 4229 4230 :term:`KFEATURE_DESCRIPTION` 4231 Provides a short description of a configuration fragment. You use 4232 this variable in the ``.scc`` file that describes a configuration 4233 fragment file. Here is the variable used in a file named ``smp.scc`` 4234 to describe SMP being enabled:: 4235 4236 define KFEATURE_DESCRIPTION "Enable SMP" 4237 4238 :term:`KMACHINE` 4239 The machine as known by the kernel. Sometimes the machine name used 4240 by the kernel does not match the machine name used by the 4241 OpenEmbedded build system. For example, the machine name that the 4242 OpenEmbedded build system understands as ``core2-32-intel-common`` 4243 goes by a different name in the Linux Yocto kernel. The kernel 4244 understands that machine as ``intel-core2-32``. For cases like these, 4245 the :term:`KMACHINE` variable maps the kernel machine name to the 4246 OpenEmbedded build system machine name. 4247 4248 These mappings between different names occur in the Yocto Linux 4249 Kernel's ``meta`` branch. As an example take a look in the 4250 ``common/recipes-kernel/linux/linux-yocto_3.19.bbappend`` file:: 4251 4252 LINUX_VERSION:core2-32-intel-common = "3.19.0" 4253 COMPATIBLE_MACHINE:core2-32-intel-common = "${MACHINE}" 4254 SRCREV_meta:core2-32-intel-common = "8897ef68b30e7426bc1d39895e71fb155d694974" 4255 SRCREV_machine:core2-32-intel-common = "43b9eced9ba8a57add36af07736344dcc383f711" 4256 KMACHINE:core2-32-intel-common = "intel-core2-32" 4257 KBRANCH:core2-32-intel-common = "standard/base" 4258 KERNEL_FEATURES:append:core2-32-intel-common = " ${KERNEL_FEATURES_INTEL_COMMON}" 4259 4260 The :term:`KMACHINE` statement says 4261 that the kernel understands the machine name as "intel-core2-32". 4262 However, the OpenEmbedded build system understands the machine as 4263 "core2-32-intel-common". 4264 4265 :term:`KTYPE` 4266 Defines the kernel type to be used in assembling the configuration. 4267 The linux-yocto recipes define "standard", "tiny", and "preempt-rt" 4268 kernel types. See the ":ref:`kernel-dev/advanced:kernel types`" 4269 section in the 4270 Yocto Project Linux Kernel Development Manual for more information on 4271 kernel types. 4272 4273 You define the :term:`KTYPE` variable in the 4274 :ref:`kernel-dev/advanced:bsp descriptions`. The 4275 value you use must match the value used for the 4276 :term:`LINUX_KERNEL_TYPE` value used by the 4277 kernel recipe. 4278 4279 :term:`LABELS` 4280 Provides a list of targets for automatic configuration. 4281 4282 See the :ref:`grub-efi <ref-classes-grub-efi>` class for more 4283 information on how this variable is used. 4284 4285 :term:`LAYERDEPENDS` 4286 Lists the layers, separated by spaces, on which this recipe depends. 4287 Optionally, you can specify a specific layer version for a dependency 4288 by adding it to the end of the layer name. Here is an example:: 4289 4290 LAYERDEPENDS_mylayer = "anotherlayer (=3)" 4291 4292 In this previous example, 4293 version 3 of "anotherlayer" is compared against 4294 :term:`LAYERVERSION`\ ``_anotherlayer``. 4295 4296 An error is produced if any dependency is missing or the version 4297 numbers (if specified) do not match exactly. This variable is used in 4298 the ``conf/layer.conf`` file and must be suffixed with the name of 4299 the specific layer (e.g. ``LAYERDEPENDS_mylayer``). 4300 4301 :term:`LAYERDIR` 4302 When used inside the ``layer.conf`` configuration file, this variable 4303 provides the path of the current layer. This variable is not 4304 available outside of ``layer.conf`` and references are expanded 4305 immediately when parsing of the file completes. 4306 4307 :term:`LAYERRECOMMENDS` 4308 Lists the layers, separated by spaces, recommended for use with this 4309 layer. 4310 4311 Optionally, you can specify a specific layer version for a 4312 recommendation by adding the version to the end of the layer name. 4313 Here is an example:: 4314 4315 LAYERRECOMMENDS_mylayer = "anotherlayer (=3)" 4316 4317 In this previous example, version 3 of "anotherlayer" is compared 4318 against ``LAYERVERSION_anotherlayer``. 4319 4320 This variable is used in the ``conf/layer.conf`` file and must be 4321 suffixed with the name of the specific layer (e.g. 4322 ``LAYERRECOMMENDS_mylayer``). 4323 4324 :term:`LAYERSERIES_COMPAT` 4325 Lists the versions of the :term:`OpenEmbedded-Core (OE-Core)` for which 4326 a layer is compatible. Using the :term:`LAYERSERIES_COMPAT` variable 4327 allows the layer maintainer to indicate which combinations of the 4328 layer and OE-Core can be expected to work. The variable gives the 4329 system a way to detect when a layer has not been tested with new 4330 releases of OE-Core (e.g. the layer is not maintained). 4331 4332 To specify the OE-Core versions for which a layer is compatible, use 4333 this variable in your layer's ``conf/layer.conf`` configuration file. 4334 For the list, use the Yocto Project 4335 :yocto_wiki:`Release Name </Releases>` (e.g. 4336 &DISTRO_NAME_NO_CAP;). To specify multiple OE-Core versions for the 4337 layer, use a space-separated list:: 4338 4339 LAYERSERIES_COMPAT_layer_root_name = "&DISTRO_NAME_NO_CAP; &DISTRO_NAME_NO_CAP_MINUS_ONE;" 4340 4341 .. note:: 4342 4343 Setting :term:`LAYERSERIES_COMPAT` is required by the Yocto Project 4344 Compatible version 2 standard. 4345 The OpenEmbedded build system produces a warning if the variable 4346 is not set for any given layer. 4347 4348 See the ":ref:`dev-manual/common-tasks:creating your own layer`" 4349 section in the Yocto Project Development Tasks Manual. 4350 4351 :term:`LAYERVERSION` 4352 Optionally specifies the version of a layer as a single number. You 4353 can use this within :term:`LAYERDEPENDS` for 4354 another layer in order to depend on a specific version of the layer. 4355 This variable is used in the ``conf/layer.conf`` file and must be 4356 suffixed with the name of the specific layer (e.g. 4357 ``LAYERVERSION_mylayer``). 4358 4359 :term:`LD` 4360 The minimal command and arguments used to run the linker. 4361 4362 :term:`LDFLAGS` 4363 Specifies the flags to pass to the linker. This variable is exported 4364 to an environment variable and thus made visible to the software 4365 being built during the compilation step. 4366 4367 Default initialization for :term:`LDFLAGS` varies depending on what is 4368 being built: 4369 4370 - :term:`TARGET_LDFLAGS` when building for the 4371 target 4372 4373 - :term:`BUILD_LDFLAGS` when building for the 4374 build host (i.e. ``-native``) 4375 4376 - :term:`BUILDSDK_LDFLAGS` when building for 4377 an SDK (i.e. ``nativesdk-``) 4378 4379 :term:`LEAD_SONAME` 4380 Specifies the lead (or primary) compiled library file (i.e. ``.so``) 4381 that the :ref:`debian <ref-classes-debian>` class applies its 4382 naming policy to given a recipe that packages multiple libraries. 4383 4384 This variable works in conjunction with the :ref:`debian <ref-classes-debian>` class. 4385 4386 :term:`LIC_FILES_CHKSUM` 4387 Checksums of the license text in the recipe source code. 4388 4389 This variable tracks changes in license text of the source code 4390 files. If the license text is changed, it will trigger a build 4391 failure, which gives the developer an opportunity to review any 4392 license change. 4393 4394 This variable must be defined for all recipes (unless 4395 :term:`LICENSE` is set to "CLOSED"). 4396 4397 For more information, see the ":ref:`dev-manual/common-tasks:tracking license changes`" 4398 section in the Yocto Project Development Tasks Manual. 4399 4400 :term:`LICENSE` 4401 The list of source licenses for the recipe. Follow these rules: 4402 4403 - Do not use spaces within individual license names. 4404 4405 - Separate license names using \| (pipe) when there is a choice 4406 between licenses. 4407 4408 - Separate license names using & (ampersand) when there are 4409 multiple licenses for different parts of the source. 4410 4411 - You can use spaces between license names. 4412 4413 - For standard licenses, use the names of the files in 4414 ``meta/files/common-licenses/`` or the 4415 :term:`SPDXLICENSEMAP` flag names defined in 4416 ``meta/conf/licenses.conf``. 4417 4418 Here are some examples:: 4419 4420 LICENSE = "LGPL-2.1-only | GPL-3.0-only" 4421 LICENSE = "MPL-1.0 & LGPL-2.1-only" 4422 LICENSE = "GPL-2.0-or-later" 4423 4424 The first example is from the 4425 recipes for Qt, which the user may choose to distribute under either 4426 the LGPL version 2.1 or GPL version 3. The second example is from 4427 Cairo where two licenses cover different parts of the source code. 4428 The final example is from ``sysstat``, which presents a single 4429 license. 4430 4431 You can also specify licenses on a per-package basis to handle 4432 situations where components of the output have different licenses. 4433 For example, a piece of software whose code is licensed under GPLv2 4434 but has accompanying documentation licensed under the GNU Free 4435 Documentation License 1.2 could be specified as follows:: 4436 4437 LICENSE = "GFDL-1.2 & GPL-2.0-only" 4438 LICENSE:${PN} = "GPL-2.0.only" 4439 LICENSE:${PN}-doc = "GFDL-1.2" 4440 4441 :term:`LICENSE_CREATE_PACKAGE` 4442 Setting :term:`LICENSE_CREATE_PACKAGE` to "1" causes the OpenEmbedded 4443 build system to create an extra package (i.e. 4444 ``${``\ :term:`PN`\ ``}-lic``) for each recipe and to add 4445 those packages to the 4446 :term:`RRECOMMENDS`\ ``:${PN}``. 4447 4448 The ``${PN}-lic`` package installs a directory in 4449 ``/usr/share/licenses`` named ``${PN}``, which is the recipe's base 4450 name, and installs files in that directory that contain license and 4451 copyright information (i.e. copies of the appropriate license files 4452 from ``meta/common-licenses`` that match the licenses specified in 4453 the :term:`LICENSE` variable of the recipe metadata 4454 and copies of files marked in 4455 :term:`LIC_FILES_CHKSUM` as containing 4456 license text). 4457 4458 For related information on providing license text, see the 4459 :term:`COPY_LIC_DIRS` variable, the 4460 :term:`COPY_LIC_MANIFEST` variable, and the 4461 ":ref:`dev-manual/common-tasks:providing license text`" 4462 section in the Yocto Project Development Tasks Manual. 4463 4464 :term:`LICENSE_FLAGS` 4465 Specifies additional flags for a recipe you must allow through 4466 :term:`LICENSE_FLAGS_ACCEPTED` in 4467 order for the recipe to be built. When providing multiple flags, 4468 separate them with spaces. 4469 4470 This value is independent of :term:`LICENSE` and is 4471 typically used to mark recipes that might require additional licenses 4472 in order to be used in a commercial product. For more information, 4473 see the 4474 ":ref:`dev-manual/common-tasks:enabling commercially licensed recipes`" 4475 section in the Yocto Project Development Tasks Manual. 4476 4477 :term:`LICENSE_FLAGS_ACCEPTED` 4478 Lists license flags that when specified in 4479 :term:`LICENSE_FLAGS` within a recipe should not 4480 prevent that recipe from being built. For more information, see the 4481 ":ref:`dev-manual/common-tasks:enabling commercially licensed recipes`" 4482 section in the Yocto Project Development Tasks Manual. 4483 4484 :term:`LICENSE_PATH` 4485 Path to additional licenses used during the build. By default, the 4486 OpenEmbedded build system uses :term:`COMMON_LICENSE_DIR` to define the 4487 directory that holds common license text used during the build. The 4488 :term:`LICENSE_PATH` variable allows you to extend that location to other 4489 areas that have additional licenses:: 4490 4491 LICENSE_PATH += "path-to-additional-common-licenses" 4492 4493 :term:`LINUX_KERNEL_TYPE` 4494 Defines the kernel type to be used in assembling the configuration. 4495 The linux-yocto recipes define "standard", "tiny", and "preempt-rt" 4496 kernel types. See the ":ref:`kernel-dev/advanced:kernel types`" 4497 section in the 4498 Yocto Project Linux Kernel Development Manual for more information on 4499 kernel types. 4500 4501 If you do not specify a :term:`LINUX_KERNEL_TYPE`, it defaults to 4502 "standard". Together with :term:`KMACHINE`, the 4503 :term:`LINUX_KERNEL_TYPE` variable defines the search arguments used by 4504 the kernel tools to find the appropriate description within the 4505 kernel :term:`Metadata` with which to build out the sources 4506 and configuration. 4507 4508 :term:`LINUX_VERSION` 4509 The Linux version from ``kernel.org`` on which the Linux kernel image 4510 being built using the OpenEmbedded build system is based. You define 4511 this variable in the kernel recipe. For example, the 4512 ``linux-yocto-3.4.bb`` kernel recipe found in 4513 ``meta/recipes-kernel/linux`` defines the variables as follows:: 4514 4515 LINUX_VERSION ?= "3.4.24" 4516 4517 The :term:`LINUX_VERSION` variable is used to define :term:`PV` 4518 for the recipe:: 4519 4520 PV = "${LINUX_VERSION}+git${SRCPV}" 4521 4522 :term:`LINUX_VERSION_EXTENSION` 4523 A string extension compiled into the version string of the Linux 4524 kernel built with the OpenEmbedded build system. You define this 4525 variable in the kernel recipe. For example, the linux-yocto kernel 4526 recipes all define the variable as follows:: 4527 4528 LINUX_VERSION_EXTENSION ?= "-yocto-${LINUX_KERNEL_TYPE}" 4529 4530 Defining this variable essentially sets the Linux kernel 4531 configuration item ``CONFIG_LOCALVERSION``, which is visible through 4532 the ``uname`` command. Here is an example that shows the extension 4533 assuming it was set as previously shown:: 4534 4535 $ uname -r 4536 3.7.0-rc8-custom 4537 4538 :term:`LOG_DIR` 4539 Specifies the directory to which the OpenEmbedded build system writes 4540 overall log files. The default directory is ``${TMPDIR}/log``. 4541 4542 For the directory containing logs specific to each task, see the 4543 :term:`T` variable. 4544 4545 :term:`MACHINE` 4546 Specifies the target device for which the image is built. You define 4547 :term:`MACHINE` in the ``local.conf`` file found in the 4548 :term:`Build Directory`. By default, :term:`MACHINE` is set to 4549 "qemux86", which is an x86-based architecture machine to be emulated 4550 using QEMU:: 4551 4552 MACHINE ?= "qemux86" 4553 4554 The variable corresponds to a machine configuration file of the same 4555 name, through which machine-specific configurations are set. Thus, 4556 when :term:`MACHINE` is set to "qemux86", the corresponding 4557 ``qemux86.conf`` machine configuration file can be found in 4558 the :term:`Source Directory` in 4559 ``meta/conf/machine``. 4560 4561 The list of machines supported by the Yocto Project as shipped 4562 include the following:: 4563 4564 MACHINE ?= "qemuarm" 4565 MACHINE ?= "qemuarm64" 4566 MACHINE ?= "qemumips" 4567 MACHINE ?= "qemumips64" 4568 MACHINE ?= "qemuppc" 4569 MACHINE ?= "qemux86" 4570 MACHINE ?= "qemux86-64" 4571 MACHINE ?= "genericx86" 4572 MACHINE ?= "genericx86-64" 4573 MACHINE ?= "beaglebone" 4574 MACHINE ?= "edgerouter" 4575 4576 The last five are Yocto Project reference hardware 4577 boards, which are provided in the ``meta-yocto-bsp`` layer. 4578 4579 .. note:: 4580 4581 Adding additional Board Support Package (BSP) layers to your 4582 configuration adds new possible settings for :term:`MACHINE`. 4583 4584 :term:`MACHINE_ARCH` 4585 Specifies the name of the machine-specific architecture. This 4586 variable is set automatically from :term:`MACHINE` or 4587 :term:`TUNE_PKGARCH`. You should not hand-edit 4588 the :term:`MACHINE_ARCH` variable. 4589 4590 :term:`MACHINE_ESSENTIAL_EXTRA_RDEPENDS` 4591 A list of required machine-specific packages to install as part of 4592 the image being built. The build process depends on these packages 4593 being present. Furthermore, because this is a "machine-essential" 4594 variable, the list of packages are essential for the machine to boot. 4595 The impact of this variable affects images based on 4596 ``packagegroup-core-boot``, including the ``core-image-minimal`` 4597 image. 4598 4599 This variable is similar to the 4600 :term:`MACHINE_ESSENTIAL_EXTRA_RRECOMMENDS` variable with the exception 4601 that the image being built has a build dependency on the variable's 4602 list of packages. In other words, the image will not build if a file 4603 in this list is not found. 4604 4605 As an example, suppose the machine for which you are building 4606 requires ``example-init`` to be run during boot to initialize the 4607 hardware. In this case, you would use the following in the machine's 4608 ``.conf`` configuration file:: 4609 4610 MACHINE_ESSENTIAL_EXTRA_RDEPENDS += "example-init" 4611 4612 :term:`MACHINE_ESSENTIAL_EXTRA_RRECOMMENDS` 4613 A list of recommended machine-specific packages to install as part of 4614 the image being built. The build process does not depend on these 4615 packages being present. However, because this is a 4616 "machine-essential" variable, the list of packages are essential for 4617 the machine to boot. The impact of this variable affects images based 4618 on ``packagegroup-core-boot``, including the ``core-image-minimal`` 4619 image. 4620 4621 This variable is similar to the :term:`MACHINE_ESSENTIAL_EXTRA_RDEPENDS` 4622 variable with the exception that the image being built does not have 4623 a build dependency on the variable's list of packages. In other 4624 words, the image will still build if a package in this list is not 4625 found. Typically, this variable is used to handle essential kernel 4626 modules, whose functionality may be selected to be built into the 4627 kernel rather than as a module, in which case a package will not be 4628 produced. 4629 4630 Consider an example where you have a custom kernel where a specific 4631 touchscreen driver is required for the machine to be usable. However, 4632 the driver can be built as a module or into the kernel depending on 4633 the kernel configuration. If the driver is built as a module, you 4634 want it to be installed. But, when the driver is built into the 4635 kernel, you still want the build to succeed. This variable sets up a 4636 "recommends" relationship so that in the latter case, the build will 4637 not fail due to the missing package. To accomplish this, assuming the 4638 package for the module was called ``kernel-module-ab123``, you would 4639 use the following in the machine's ``.conf`` configuration file:: 4640 4641 MACHINE_ESSENTIAL_EXTRA_RRECOMMENDS += "kernel-module-ab123" 4642 4643 .. note:: 4644 4645 In this example, the ``kernel-module-ab123`` recipe needs to 4646 explicitly set its :term:`PACKAGES` variable to ensure that BitBake 4647 does not use the kernel recipe's :term:`PACKAGES_DYNAMIC` variable to 4648 satisfy the dependency. 4649 4650 Some examples of these machine essentials are flash, screen, 4651 keyboard, mouse, or touchscreen drivers (depending on the machine). 4652 4653 :term:`MACHINE_EXTRA_RDEPENDS` 4654 A list of machine-specific packages to install as part of the image 4655 being built that are not essential for the machine to boot. However, 4656 the build process for more fully-featured images depends on the 4657 packages being present. 4658 4659 This variable affects all images based on ``packagegroup-base``, 4660 which does not include the ``core-image-minimal`` or 4661 ``core-image-full-cmdline`` images. 4662 4663 The variable is similar to the :term:`MACHINE_EXTRA_RRECOMMENDS` variable 4664 with the exception that the image being built has a build dependency 4665 on the variable's list of packages. In other words, the image will 4666 not build if a file in this list is not found. 4667 4668 An example is a machine that has WiFi capability but is not essential 4669 for the machine to boot the image. However, if you are building a 4670 more fully-featured image, you want to enable the WiFi. The package 4671 containing the firmware for the WiFi hardware is always expected to 4672 exist, so it is acceptable for the build process to depend upon 4673 finding the package. In this case, assuming the package for the 4674 firmware was called ``wifidriver-firmware``, you would use the 4675 following in the ``.conf`` file for the machine:: 4676 4677 MACHINE_EXTRA_RDEPENDS += "wifidriver-firmware" 4678 4679 :term:`MACHINE_EXTRA_RRECOMMENDS` 4680 A list of machine-specific packages to install as part of the image 4681 being built that are not essential for booting the machine. The image 4682 being built has no build dependency on this list of packages. 4683 4684 This variable affects only images based on ``packagegroup-base``, 4685 which does not include the ``core-image-minimal`` or 4686 ``core-image-full-cmdline`` images. 4687 4688 This variable is similar to the :term:`MACHINE_EXTRA_RDEPENDS` variable 4689 with the exception that the image being built does not have a build 4690 dependency on the variable's list of packages. In other words, the 4691 image will build if a file in this list is not found. 4692 4693 An example is a machine that has WiFi capability but is not essential 4694 For the machine to boot the image. However, if you are building a 4695 more fully-featured image, you want to enable WiFi. In this case, the 4696 package containing the WiFi kernel module will not be produced if the 4697 WiFi driver is built into the kernel, in which case you still want 4698 the build to succeed instead of failing as a result of the package 4699 not being found. To accomplish this, assuming the package for the 4700 module was called ``kernel-module-examplewifi``, you would use the 4701 following in the ``.conf`` file for the machine:: 4702 4703 MACHINE_EXTRA_RRECOMMENDS += "kernel-module-examplewifi" 4704 4705 :term:`MACHINE_FEATURES` 4706 Specifies the list of hardware features the 4707 :term:`MACHINE` is capable of supporting. For related 4708 information on enabling features, see the 4709 :term:`DISTRO_FEATURES`, 4710 :term:`COMBINED_FEATURES`, and 4711 :term:`IMAGE_FEATURES` variables. 4712 4713 For a list of hardware features supported by the Yocto Project as 4714 shipped, see the ":ref:`ref-features-machine`" section. 4715 4716 :term:`MACHINE_FEATURES_BACKFILL` 4717 Features to be added to :term:`MACHINE_FEATURES` if not also present in 4718 :term:`MACHINE_FEATURES_BACKFILL_CONSIDERED`. 4719 4720 This variable is set in the ``meta/conf/bitbake.conf`` file. It is 4721 not intended to be user-configurable. It is best to just reference 4722 the variable to see which machine features are being backfilled for 4723 all machine configurations. See the ":ref:`ref-features-backfill`" 4724 section for more information. 4725 4726 :term:`MACHINE_FEATURES_BACKFILL_CONSIDERED` 4727 Features from :term:`MACHINE_FEATURES_BACKFILL` that should not be 4728 backfilled (i.e. added to :term:`MACHINE_FEATURES`) during the build. See 4729 the ":ref:`ref-features-backfill`" section for more information. 4730 4731 :term:`MACHINEOVERRIDES` 4732 A colon-separated list of overrides that apply to the current 4733 machine. By default, this list includes the value of 4734 :term:`MACHINE`. 4735 4736 You can extend :term:`MACHINEOVERRIDES` to add extra overrides that 4737 should apply to a machine. For example, all machines emulated in QEMU 4738 (e.g. ``qemuarm``, ``qemux86``, and so forth) include a file named 4739 ``meta/conf/machine/include/qemu.inc`` that prepends the following 4740 override to :term:`MACHINEOVERRIDES`:: 4741 4742 MACHINEOVERRIDES =. "qemuall:" 4743 4744 This 4745 override allows variables to be overridden for all machines emulated 4746 in QEMU, like in the following example from the ``connman-conf`` 4747 recipe:: 4748 4749 SRC_URI:append:qemuall = " file://wired.config \ 4750 file://wired-setup \ 4751 " 4752 4753 The underlying mechanism behind 4754 :term:`MACHINEOVERRIDES` is simply that it is included in the default 4755 value of :term:`OVERRIDES`. 4756 4757 :term:`MAINTAINER` 4758 The email address of the distribution maintainer. 4759 4760 :term:`METADATA_BRANCH` 4761 The branch currently checked out for the OpenEmbedded-Core layer (path 4762 determined by :term:`COREBASE`). 4763 4764 :term:`METADATA_REVISION` 4765 The revision currently checked out for the OpenEmbedded-Core layer (path 4766 determined by :term:`COREBASE`). 4767 4768 :term:`MIRRORS` 4769 Specifies additional paths from which the OpenEmbedded build system 4770 gets source code. When the build system searches for source code, it 4771 first tries the local download directory. If that location fails, the 4772 build system tries locations defined by 4773 :term:`PREMIRRORS`, the upstream source, and then 4774 locations specified by :term:`MIRRORS` in that order. 4775 4776 Assuming your distribution (:term:`DISTRO`) is "poky", 4777 the default value for :term:`MIRRORS` is defined in the 4778 ``conf/distro/poky.conf`` file in the ``meta-poky`` Git repository. 4779 4780 :term:`MLPREFIX` 4781 Specifies a prefix has been added to :term:`PN` to create a 4782 special version of a recipe or package (i.e. a Multilib version). The 4783 variable is used in places where the prefix needs to be added to or 4784 removed from a the name (e.g. the :term:`BPN` variable). 4785 :term:`MLPREFIX` gets set when a prefix has been added to :term:`PN`. 4786 4787 .. note:: 4788 4789 The "ML" in :term:`MLPREFIX` stands for "MultiLib". This representation is 4790 historical and comes from a time when ``nativesdk`` was a suffix 4791 rather than a prefix on the recipe name. When ``nativesdk`` was turned 4792 into a prefix, it made sense to set :term:`MLPREFIX` for it as well. 4793 4794 To help understand when :term:`MLPREFIX` might be needed, consider when 4795 :term:`BBCLASSEXTEND` is used to provide a 4796 ``nativesdk`` version of a recipe in addition to the target version. 4797 If that recipe declares build-time dependencies on tasks in other 4798 recipes by using :term:`DEPENDS`, then a dependency on 4799 "foo" will automatically get rewritten to a dependency on 4800 "nativesdk-foo". However, dependencies like the following will not 4801 get rewritten automatically:: 4802 4803 do_foo[depends] += "recipe:do_foo" 4804 4805 If you want such a dependency to also get transformed, you can do the 4806 following:: 4807 4808 do_foo[depends] += "${MLPREFIX}recipe:do_foo" 4809 4810 :term:`module_autoload` 4811 This variable has been replaced by the :term:`KERNEL_MODULE_AUTOLOAD` 4812 variable. You should replace all occurrences of :term:`module_autoload` 4813 with additions to :term:`KERNEL_MODULE_AUTOLOAD`, for example:: 4814 4815 module_autoload_rfcomm = "rfcomm" 4816 4817 should now be replaced with:: 4818 4819 KERNEL_MODULE_AUTOLOAD += "rfcomm" 4820 4821 See the :term:`KERNEL_MODULE_AUTOLOAD` variable for more information. 4822 4823 :term:`module_conf` 4824 Specifies `modprobe.d <https://linux.die.net/man/5/modprobe.d>`_ 4825 syntax lines for inclusion in the ``/etc/modprobe.d/modname.conf`` 4826 file. 4827 4828 You can use this variable anywhere that it can be recognized by the 4829 kernel recipe or out-of-tree kernel module recipe (e.g. a machine 4830 configuration file, a distribution configuration file, an append file 4831 for the recipe, or the recipe itself). If you use this variable, you 4832 must also be sure to list the module name in the 4833 :term:`KERNEL_MODULE_PROBECONF` 4834 variable. 4835 4836 Here is the general syntax:: 4837 4838 module_conf_module_name = "modprobe.d-syntax" 4839 4840 You must use the kernel module name override. 4841 4842 Run ``man modprobe.d`` in the shell to find out more information on 4843 the exact syntax you want to provide with :term:`module_conf`. 4844 4845 Including :term:`module_conf` causes the OpenEmbedded build system to 4846 populate the ``/etc/modprobe.d/modname.conf`` file with 4847 ``modprobe.d`` syntax lines. Here is an example that adds the options 4848 ``arg1`` and ``arg2`` to a module named ``mymodule``:: 4849 4850 module_conf_mymodule = "options mymodule arg1=val1 arg2=val2" 4851 4852 For information on how to specify kernel modules to auto-load on 4853 boot, see the :term:`KERNEL_MODULE_AUTOLOAD` variable. 4854 4855 :term:`MODULE_TARBALL_DEPLOY` 4856 Controls creation of the ``modules-*.tgz`` file. Set this variable to 4857 "0" to disable creation of this file, which contains all of the 4858 kernel modules resulting from a kernel build. 4859 4860 :term:`MODULE_TARBALL_LINK_NAME` 4861 The link name of the kernel module tarball. This variable is set in 4862 the ``meta/classes/kernel-artifact-names.bbclass`` file as follows:: 4863 4864 MODULE_TARBALL_LINK_NAME ?= "${KERNEL_ARTIFACT_LINK_NAME}" 4865 4866 The value 4867 of the ``KERNEL_ARTIFACT_LINK_NAME`` variable, which is set in the 4868 same file, has the following value:: 4869 4870 KERNEL_ARTIFACT_LINK_NAME ?= "${MACHINE}" 4871 4872 See the :term:`MACHINE` variable for additional information. 4873 4874 :term:`MODULE_TARBALL_NAME` 4875 The base name of the kernel module tarball. This variable is set in 4876 the ``meta/classes/kernel-artifact-names.bbclass`` file as follows:: 4877 4878 MODULE_TARBALL_NAME ?= "${KERNEL_ARTIFACT_NAME}" 4879 4880 The value of the :term:`KERNEL_ARTIFACT_NAME` variable, 4881 which is set in the same file, has the following value:: 4882 4883 KERNEL_ARTIFACT_NAME ?= "${PKGE}-${PKGV}-${PKGR}-${MACHINE}${IMAGE_VERSION_SUFFIX}" 4884 4885 :term:`MULTIMACH_TARGET_SYS` 4886 Uniquely identifies the type of the target system for which packages 4887 are being built. This variable allows output for different types of 4888 target systems to be put into different subdirectories of the same 4889 output directory. 4890 4891 The default value of this variable is:: 4892 4893 ${PACKAGE_ARCH}${TARGET_VENDOR}-${TARGET_OS} 4894 4895 Some classes (e.g. 4896 :ref:`cross-canadian <ref-classes-cross-canadian>`) modify the 4897 :term:`MULTIMACH_TARGET_SYS` value. 4898 4899 See the :term:`STAMP` variable for an example. See the 4900 :term:`STAGING_DIR_TARGET` variable for more information. 4901 4902 :term:`NATIVELSBSTRING` 4903 A string identifying the host distribution. Strings consist of the 4904 host distributor ID followed by the release, as reported by the 4905 ``lsb_release`` tool or as read from ``/etc/lsb-release``. For 4906 example, when running a build on Ubuntu 12.10, the value is 4907 "Ubuntu-12.10". If this information is unable to be determined, the 4908 value resolves to "Unknown". 4909 4910 This variable is used by default to isolate native shared state 4911 packages for different distributions (e.g. to avoid problems with 4912 ``glibc`` version incompatibilities). Additionally, the variable is 4913 checked against 4914 :term:`SANITY_TESTED_DISTROS` if that 4915 variable is set. 4916 4917 :term:`NM` 4918 The minimal command and arguments to run ``nm``. 4919 4920 :term:`NO_GENERIC_LICENSE` 4921 Avoids QA errors when you use a non-common, non-CLOSED license in a 4922 recipe. There are packages, such as the linux-firmware package, with many 4923 licenses that are not in any way common. Also, new licenses are added 4924 occasionally to avoid introducing a lot of common license files, 4925 which are only applicable to a specific package. 4926 :term:`NO_GENERIC_LICENSE` is used to allow copying a license that does 4927 not exist in common licenses. 4928 4929 The following example shows how to add :term:`NO_GENERIC_LICENSE` to a 4930 recipe:: 4931 4932 NO_GENERIC_LICENSE[license_name] = "license_file_in_fetched_source" 4933 4934 Here is an example that 4935 uses the ``LICENSE.Abilis.txt`` file as the license from the fetched 4936 source:: 4937 4938 NO_GENERIC_LICENSE[Firmware-Abilis] = "LICENSE.Abilis.txt" 4939 4940 :term:`NO_RECOMMENDATIONS` 4941 Prevents installation of all "recommended-only" packages. 4942 Recommended-only packages are packages installed only through the 4943 :term:`RRECOMMENDS` variable). Setting the 4944 :term:`NO_RECOMMENDATIONS` variable to "1" turns this feature on:: 4945 4946 NO_RECOMMENDATIONS = "1" 4947 4948 You can set this variable globally in your ``local.conf`` file or you 4949 can attach it to a specific image recipe by using the recipe name 4950 override:: 4951 4952 NO_RECOMMENDATIONS:pn-target_image = "1" 4953 4954 It is important to realize that if you choose to not install packages 4955 using this variable and some other packages are dependent on them 4956 (i.e. listed in a recipe's :term:`RDEPENDS` 4957 variable), the OpenEmbedded build system ignores your request and 4958 will install the packages to avoid dependency errors. 4959 4960 .. note:: 4961 4962 Some recommended packages might be required for certain system 4963 functionality, such as kernel modules. It is up to you to add 4964 packages with the :term:`IMAGE_INSTALL` variable. 4965 4966 This variable is only supported when using the IPK and RPM 4967 packaging backends. DEB is not supported. 4968 4969 See the :term:`BAD_RECOMMENDATIONS` and 4970 the :term:`PACKAGE_EXCLUDE` variables for 4971 related information. 4972 4973 :term:`NOAUTOPACKAGEDEBUG` 4974 Disables auto package from splitting ``.debug`` files. If a recipe 4975 requires ``FILES:${PN}-dbg`` to be set manually, the 4976 :term:`NOAUTOPACKAGEDEBUG` can be defined allowing you to define the 4977 content of the debug package. For example:: 4978 4979 NOAUTOPACKAGEDEBUG = "1" 4980 FILES:${PN}-dev = "${includedir}/${QT_DIR_NAME}/Qt/*" 4981 FILES:${PN}-dbg = "/usr/src/debug/" 4982 FILES:${QT_BASE_NAME}-demos-doc = "${docdir}/${QT_DIR_NAME}/qch/qt.qch" 4983 4984 :term:`NON_MULTILIB_RECIPES` 4985 A list of recipes that should not be built for multilib. OE-Core's 4986 ``multilib.conf`` file defines a reasonable starting point for this 4987 list with:: 4988 4989 NON_MULTILIB_RECIPES = "grub grub-efi make-mod-scripts ovmf u-boot" 4990 4991 :term:`OBJCOPY` 4992 The minimal command and arguments to run ``objcopy``. 4993 4994 :term:`OBJDUMP` 4995 The minimal command and arguments to run ``objdump``. 4996 4997 :term:`OE_BINCONFIG_EXTRA_MANGLE` 4998 When inheriting the :ref:`binconfig <ref-classes-binconfig>` class, 4999 this variable specifies additional arguments passed to the "sed" 5000 command. The sed command alters any paths in configuration scripts 5001 that have been set up during compilation. Inheriting this class 5002 results in all paths in these scripts being changed to point into the 5003 ``sysroots/`` directory so that all builds that use the script will 5004 use the correct directories for the cross compiling layout. 5005 5006 See the ``meta/classes/binconfig.bbclass`` in the 5007 :term:`Source Directory` for details on how this class 5008 applies these additional sed command arguments. 5009 5010 :term:`OE_IMPORTS` 5011 An internal variable used to tell the OpenEmbedded build system what 5012 Python modules to import for every Python function run by the system. 5013 5014 .. note:: 5015 5016 Do not set this variable. It is for internal use only. 5017 5018 :term:`OE_INIT_ENV_SCRIPT` 5019 The name of the build environment setup script for the purposes of 5020 setting up the environment within the extensible SDK. The default 5021 value is "oe-init-build-env". 5022 5023 If you use a custom script to set up your build environment, set the 5024 :term:`OE_INIT_ENV_SCRIPT` variable to its name. 5025 5026 :term:`OE_TERMINAL` 5027 Controls how the OpenEmbedded build system spawns interactive 5028 terminals on the host development system (e.g. using the BitBake 5029 command with the ``-c devshell`` command-line option). For more 5030 information, see the ":ref:`dev-manual/common-tasks:using a development shell`" section in 5031 the Yocto Project Development Tasks Manual. 5032 5033 You can use the following values for the :term:`OE_TERMINAL` variable: 5034 5035 - auto 5036 - gnome 5037 - xfce 5038 - rxvt 5039 - screen 5040 - konsole 5041 - none 5042 5043 :term:`OEROOT` 5044 The directory from which the top-level build environment setup script 5045 is sourced. The Yocto Project provides a top-level build environment 5046 setup script: :ref:`structure-core-script`. When you run this 5047 script, the :term:`OEROOT` variable resolves to the directory that 5048 contains the script. 5049 5050 For additional information on how this variable is used, see the 5051 initialization script. 5052 5053 :term:`OLDEST_KERNEL` 5054 Declares the oldest version of the Linux kernel that the produced 5055 binaries must support. This variable is passed into the build of the 5056 Embedded GNU C Library (``glibc``). 5057 5058 The default for this variable comes from the 5059 ``meta/conf/bitbake.conf`` configuration file. You can override this 5060 default by setting the variable in a custom distribution 5061 configuration file. 5062 5063 :term:`OVERRIDES` 5064 A colon-separated list of overrides that currently apply. Overrides 5065 are a BitBake mechanism that allows variables to be selectively 5066 overridden at the end of parsing. The set of overrides in 5067 :term:`OVERRIDES` represents the "state" during building, which includes 5068 the current recipe being built, the machine for which it is being 5069 built, and so forth. 5070 5071 As an example, if the string "an-override" appears as an element in 5072 the colon-separated list in :term:`OVERRIDES`, then the following 5073 assignment will override ``FOO`` with the value "overridden" at the 5074 end of parsing:: 5075 5076 FOO:an-override = "overridden" 5077 5078 See the 5079 ":ref:`bitbake:bitbake-user-manual/bitbake-user-manual-metadata:conditional syntax (overrides)`" 5080 section in the BitBake User Manual for more information on the 5081 overrides mechanism. 5082 5083 The default value of :term:`OVERRIDES` includes the values of the 5084 :term:`CLASSOVERRIDE`, 5085 :term:`MACHINEOVERRIDES`, and 5086 :term:`DISTROOVERRIDES` variables. Another 5087 important override included by default is ``pn-${PN}``. This override 5088 allows variables to be set for a single recipe within configuration 5089 (``.conf``) files. Here is an example:: 5090 5091 FOO:pn-myrecipe = "myrecipe-specific value" 5092 5093 .. note:: 5094 5095 An easy way to see what overrides apply is to search for :term:`OVERRIDES` 5096 in the output of the ``bitbake -e`` command. See the 5097 ":ref:`dev-manual/common-tasks:viewing variable values`" section in the Yocto 5098 Project Development Tasks Manual for more information. 5099 5100 :term:`P` 5101 The recipe name and version. :term:`P` is comprised of the following:: 5102 5103 ${PN}-${PV} 5104 5105 :term:`PACKAGE_ADD_METADATA` 5106 This variable defines additional metadata to add to packages. 5107 5108 You may find you need to inject additional metadata into packages. 5109 This variable allows you to do that by setting the injected data as 5110 the value. Multiple fields can be added by splitting the content with 5111 the literal separator "\n". 5112 5113 The suffixes '_IPK', '_DEB', or '_RPM' can be applied to the variable 5114 to do package type specific settings. It can also be made package 5115 specific by using the package name as a suffix. 5116 5117 You can find out more about applying this variable in the 5118 ":ref:`dev-manual/common-tasks:adding custom metadata to packages`" 5119 section in the Yocto Project Development Tasks Manual. 5120 5121 :term:`PACKAGE_ARCH` 5122 The architecture of the resulting package or packages. 5123 5124 By default, the value of this variable is set to 5125 :term:`TUNE_PKGARCH` when building for the 5126 target, :term:`BUILD_ARCH` when building for the 5127 build host, and "${SDK_ARCH}-${SDKPKGSUFFIX}" when building for the 5128 SDK. 5129 5130 .. note:: 5131 5132 See :term:`SDK_ARCH` for more information. 5133 5134 However, if your recipe's output packages are built specific to the 5135 target machine rather than generally for the architecture of the 5136 machine, you should set :term:`PACKAGE_ARCH` to the value of 5137 :term:`MACHINE_ARCH` in the recipe as follows:: 5138 5139 PACKAGE_ARCH = "${MACHINE_ARCH}" 5140 5141 :term:`PACKAGE_ARCHS` 5142 Specifies a list of architectures compatible with the target machine. 5143 This variable is set automatically and should not normally be 5144 hand-edited. Entries are separated using spaces and listed in order 5145 of priority. The default value for :term:`PACKAGE_ARCHS` is "all any 5146 noarch ${PACKAGE_EXTRA_ARCHS} ${MACHINE_ARCH}". 5147 5148 :term:`PACKAGE_BEFORE_PN` 5149 Enables easily adding packages to :term:`PACKAGES` before ``${PN}`` so 5150 that those added packages can pick up files that would normally be 5151 included in the default package. 5152 5153 :term:`PACKAGE_CLASSES` 5154 This variable, which is set in the ``local.conf`` configuration file 5155 found in the ``conf`` folder of the 5156 :term:`Build Directory`, specifies the package manager the 5157 OpenEmbedded build system uses when packaging data. 5158 5159 You can provide one or more of the following arguments for the 5160 variable: PACKAGE_CLASSES ?= "package_rpm package_deb package_ipk 5161 package_tar" 5162 5163 .. note:: 5164 5165 While it is a legal option, the ``package_tar`` 5166 class has limited functionality due to no support for package 5167 dependencies by that backend. Therefore, it is recommended that 5168 you do not use it. 5169 5170 The build system uses only the first argument in the list as the 5171 package manager when creating your image or SDK. However, packages 5172 will be created using any additional packaging classes you specify. 5173 For example, if you use the following in your ``local.conf`` file:: 5174 5175 PACKAGE_CLASSES ?= "package_ipk" 5176 5177 The OpenEmbedded build system uses 5178 the IPK package manager to create your image or SDK. 5179 5180 For information on packaging and build performance effects as a 5181 result of the package manager in use, see the 5182 ":ref:`ref-classes-package`" section. 5183 5184 :term:`PACKAGE_DEBUG_SPLIT_STYLE` 5185 Determines how to split up and package debug and source information 5186 when creating debugging packages to be used with the GNU Project 5187 Debugger (GDB). In general, based on the value of this variable, 5188 you can combine the source and debug info in a single package, 5189 you can break out the source into a separate package that can be 5190 installed independently, or you can choose to not have the source 5191 packaged at all. 5192 5193 The possible values of :term:`PACKAGE_DEBUG_SPLIT_STYLE` variable: 5194 5195 - "``.debug``": All debugging and source info is placed in a single 5196 ``*-dbg`` package; debug symbol files are placed next to the 5197 binary in a ``.debug`` directory so that, if a binary is installed 5198 into ``/bin``, the corresponding debug symbol file is installed 5199 in ``/bin/.debug``. Source files are installed in the same ``*-dbg`` 5200 package under ``/usr/src/debug``. 5201 5202 - "``debug-file-directory``": As above, all debugging and source info 5203 is placed in a single ``*-dbg`` package; debug symbol files are 5204 placed entirely under the directory ``/usr/lib/debug`` and separated 5205 by the path from where the binary is installed, so that if a binary 5206 is installed in ``/bin``, the corresponding debug symbols are installed 5207 in ``/usr/lib/debug/bin``, and so on. As above, source is installed 5208 in the same package under ``/usr/src/debug``. 5209 5210 - "``debug-with-srcpkg``": Debugging info is placed in the standard 5211 ``*-dbg`` package as with the ``.debug`` value, while source is 5212 placed in a separate ``*-src`` package, which can be installed 5213 independently. This is the default setting for this variable, 5214 as defined in Poky's ``bitbake.conf`` file. 5215 5216 - "``debug-without-src``": The same behavior as with the ``.debug`` 5217 setting, but no source is packaged at all. 5218 5219 .. note:: 5220 5221 Much of the above package splitting can be overridden via 5222 use of the :term:`INHIBIT_PACKAGE_DEBUG_SPLIT` variable. 5223 5224 You can find out more about debugging using GDB by reading the 5225 ":ref:`dev-manual/common-tasks:debugging with the gnu project debugger (gdb) remotely`" section 5226 in the Yocto Project Development Tasks Manual. 5227 5228 :term:`PACKAGE_EXCLUDE` 5229 Lists packages that should not be installed into an image. For 5230 example:: 5231 5232 PACKAGE_EXCLUDE = "package_name package_name package_name ..." 5233 5234 You can set this variable globally in your ``local.conf`` file or you 5235 can attach it to a specific image recipe by using the recipe name 5236 override:: 5237 5238 PACKAGE_EXCLUDE:pn-target_image = "package_name" 5239 5240 If you choose to not install a package using this variable and some 5241 other package is dependent on it (i.e. listed in a recipe's 5242 :term:`RDEPENDS` variable), the OpenEmbedded build 5243 system generates a fatal installation error. Because the build system 5244 halts the process with a fatal error, you can use the variable with 5245 an iterative development process to remove specific components from a 5246 system. 5247 5248 This variable is supported only when using the IPK and RPM 5249 packaging backends. DEB is not supported. 5250 5251 See the :term:`NO_RECOMMENDATIONS` and the 5252 :term:`BAD_RECOMMENDATIONS` variables for 5253 related information. 5254 5255 :term:`PACKAGE_EXCLUDE_COMPLEMENTARY` 5256 Prevents specific packages from being installed when you are 5257 installing complementary packages. 5258 5259 You might find that you want to prevent installing certain packages 5260 when you are installing complementary packages. For example, if you 5261 are using :term:`IMAGE_FEATURES` to install 5262 ``dev-pkgs``, you might not want to install all packages from a 5263 particular multilib. If you find yourself in this situation, you can 5264 use the :term:`PACKAGE_EXCLUDE_COMPLEMENTARY` variable to specify regular 5265 expressions to match the packages you want to exclude. 5266 5267 :term:`PACKAGE_EXTRA_ARCHS` 5268 Specifies the list of architectures compatible with the device CPU. 5269 This variable is useful when you build for several different devices 5270 that use miscellaneous processors such as XScale and ARM926-EJS. 5271 5272 :term:`PACKAGE_FEED_ARCHS` 5273 Optionally specifies the package architectures used as part of the 5274 package feed URIs during the build. When used, the 5275 :term:`PACKAGE_FEED_ARCHS` variable is appended to the final package feed 5276 URI, which is constructed using the 5277 :term:`PACKAGE_FEED_URIS` and 5278 :term:`PACKAGE_FEED_BASE_PATHS` 5279 variables. 5280 5281 .. note:: 5282 5283 You can use the :term:`PACKAGE_FEED_ARCHS` 5284 variable to allow specific package architectures. If you do 5285 not need to allow specific architectures, which is a common 5286 case, you can omit this variable. Omitting the variable results in 5287 all available architectures for the current machine being included 5288 into remote package feeds. 5289 5290 Consider the following example where the :term:`PACKAGE_FEED_URIS`, 5291 :term:`PACKAGE_FEED_BASE_PATHS`, and :term:`PACKAGE_FEED_ARCHS` variables are 5292 defined in your ``local.conf`` file:: 5293 5294 PACKAGE_FEED_URIS = "https://example.com/packagerepos/release \ 5295 https://example.com/packagerepos/updates" 5296 PACKAGE_FEED_BASE_PATHS = "rpm rpm-dev" 5297 PACKAGE_FEED_ARCHS = "all core2-64" 5298 5299 Given these settings, the resulting package feeds are as follows: 5300 5301 .. code-block:: none 5302 5303 https://example.com/packagerepos/release/rpm/all 5304 https://example.com/packagerepos/release/rpm/core2-64 5305 https://example.com/packagerepos/release/rpm-dev/all 5306 https://example.com/packagerepos/release/rpm-dev/core2-64 5307 https://example.com/packagerepos/updates/rpm/all 5308 https://example.com/packagerepos/updates/rpm/core2-64 5309 https://example.com/packagerepos/updates/rpm-dev/all 5310 https://example.com/packagerepos/updates/rpm-dev/core2-64 5311 5312 :term:`PACKAGE_FEED_BASE_PATHS` 5313 Specifies the base path used when constructing package feed URIs. The 5314 :term:`PACKAGE_FEED_BASE_PATHS` variable makes up the middle portion of a 5315 package feed URI used by the OpenEmbedded build system. The base path 5316 lies between the :term:`PACKAGE_FEED_URIS` 5317 and :term:`PACKAGE_FEED_ARCHS` variables. 5318 5319 Consider the following example where the :term:`PACKAGE_FEED_URIS`, 5320 :term:`PACKAGE_FEED_BASE_PATHS`, and :term:`PACKAGE_FEED_ARCHS` variables are 5321 defined in your ``local.conf`` file:: 5322 5323 PACKAGE_FEED_URIS = "https://example.com/packagerepos/release \ 5324 https://example.com/packagerepos/updates" 5325 PACKAGE_FEED_BASE_PATHS = "rpm rpm-dev" 5326 PACKAGE_FEED_ARCHS = "all core2-64" 5327 5328 Given these settings, the resulting package feeds are as follows: 5329 5330 .. code-block:: none 5331 5332 https://example.com/packagerepos/release/rpm/all 5333 https://example.com/packagerepos/release/rpm/core2-64 5334 https://example.com/packagerepos/release/rpm-dev/all 5335 https://example.com/packagerepos/release/rpm-dev/core2-64 5336 https://example.com/packagerepos/updates/rpm/all 5337 https://example.com/packagerepos/updates/rpm/core2-64 5338 https://example.com/packagerepos/updates/rpm-dev/all 5339 https://example.com/packagerepos/updates/rpm-dev/core2-64 5340 5341 :term:`PACKAGE_FEED_URIS` 5342 Specifies the front portion of the package feed URI used by the 5343 OpenEmbedded build system. Each final package feed URI is comprised 5344 of :term:`PACKAGE_FEED_URIS`, 5345 :term:`PACKAGE_FEED_BASE_PATHS`, and 5346 :term:`PACKAGE_FEED_ARCHS` variables. 5347 5348 Consider the following example where the :term:`PACKAGE_FEED_URIS`, 5349 :term:`PACKAGE_FEED_BASE_PATHS`, and :term:`PACKAGE_FEED_ARCHS` variables are 5350 defined in your ``local.conf`` file:: 5351 5352 PACKAGE_FEED_URIS = "https://example.com/packagerepos/release \ 5353 https://example.com/packagerepos/updates" 5354 PACKAGE_FEED_BASE_PATHS = "rpm rpm-dev" 5355 PACKAGE_FEED_ARCHS = "all core2-64" 5356 5357 Given these settings, the resulting package feeds are as follows: 5358 5359 .. code-block:: none 5360 5361 https://example.com/packagerepos/release/rpm/all 5362 https://example.com/packagerepos/release/rpm/core2-64 5363 https://example.com/packagerepos/release/rpm-dev/all 5364 https://example.com/packagerepos/release/rpm-dev/core2-64 5365 https://example.com/packagerepos/updates/rpm/all 5366 https://example.com/packagerepos/updates/rpm/core2-64 5367 https://example.com/packagerepos/updates/rpm-dev/all 5368 https://example.com/packagerepos/updates/rpm-dev/core2-64 5369 5370 :term:`PACKAGE_INSTALL` 5371 The final list of packages passed to the package manager for 5372 installation into the image. 5373 5374 Because the package manager controls actual installation of all 5375 packages, the list of packages passed using :term:`PACKAGE_INSTALL` is 5376 not the final list of packages that are actually installed. This 5377 variable is internal to the image construction code. Consequently, in 5378 general, you should use the 5379 :term:`IMAGE_INSTALL` variable to specify 5380 packages for installation. The exception to this is when working with 5381 the :ref:`core-image-minimal-initramfs <ref-manual/images:images>` 5382 image. When working with an initial RAM filesystem (initramfs) image, 5383 use the :term:`PACKAGE_INSTALL` variable. For information on creating an 5384 initramfs, see the ":ref:`dev-manual/common-tasks:building an initial ram filesystem (initramfs) image`" section 5385 in the Yocto Project Development Tasks Manual. 5386 5387 :term:`PACKAGE_INSTALL_ATTEMPTONLY` 5388 Specifies a list of packages the OpenEmbedded build system attempts 5389 to install when creating an image. If a listed package fails to 5390 install, the build system does not generate an error. This variable 5391 is generally not user-defined. 5392 5393 :term:`PACKAGE_PREPROCESS_FUNCS` 5394 Specifies a list of functions run to pre-process the 5395 :term:`PKGD` directory prior to splitting the files out 5396 to individual packages. 5397 5398 :term:`PACKAGE_WRITE_DEPS` 5399 Specifies a list of dependencies for post-installation and 5400 pre-installation scripts on native/cross tools. If your 5401 post-installation or pre-installation script can execute at root filesystem 5402 creation time rather than on the target but depends on a native tool 5403 in order to execute, you need to list the tools in 5404 :term:`PACKAGE_WRITE_DEPS`. 5405 5406 For information on running post-installation scripts, see the 5407 ":ref:`dev-manual/common-tasks:post-installation scripts`" 5408 section in the Yocto Project Development Tasks Manual. 5409 5410 :term:`PACKAGECONFIG` 5411 This variable provides a means of enabling or disabling features of a 5412 recipe on a per-recipe basis. :term:`PACKAGECONFIG` blocks are defined in 5413 recipes when you specify features and then arguments that define 5414 feature behaviors. Here is the basic block structure (broken over 5415 multiple lines for readability):: 5416 5417 PACKAGECONFIG ??= "f1 f2 f3 ..." 5418 PACKAGECONFIG[f1] = "\ 5419 --with-f1, \ 5420 --without-f1, \ 5421 build-deps-for-f1, \ 5422 runtime-deps-for-f1, \ 5423 runtime-recommends-for-f1, \ 5424 packageconfig-conflicts-for-f1" 5425 PACKAGECONFIG[f2] = "\ 5426 ... and so on and so on ... 5427 5428 The :term:`PACKAGECONFIG` variable itself specifies a space-separated 5429 list of the features to enable. Following the features, you can 5430 determine the behavior of each feature by providing up to six 5431 order-dependent arguments, which are separated by commas. You can 5432 omit any argument you like but must retain the separating commas. The 5433 order is important and specifies the following: 5434 5435 1. Extra arguments that should be added to the configure script 5436 argument list (:term:`EXTRA_OECONF` or 5437 :term:`PACKAGECONFIG_CONFARGS`) if 5438 the feature is enabled. 5439 5440 2. Extra arguments that should be added to :term:`EXTRA_OECONF` or 5441 :term:`PACKAGECONFIG_CONFARGS` if the feature is disabled. 5442 5443 3. Additional build dependencies (:term:`DEPENDS`) 5444 that should be added if the feature is enabled. 5445 5446 4. Additional runtime dependencies (:term:`RDEPENDS`) 5447 that should be added if the feature is enabled. 5448 5449 5. Additional runtime recommendations 5450 (:term:`RRECOMMENDS`) that should be added if 5451 the feature is enabled. 5452 5453 6. Any conflicting (that is, mutually exclusive) :term:`PACKAGECONFIG` 5454 settings for this feature. 5455 5456 Consider the following :term:`PACKAGECONFIG` block taken from the 5457 ``librsvg`` recipe. In this example the feature is ``gtk``, which has 5458 three arguments that determine the feature's behavior. 5459 :: 5460 5461 PACKAGECONFIG[gtk] = "--with-gtk3,--without-gtk3,gtk+3" 5462 5463 The 5464 ``--with-gtk3`` and ``gtk+3`` arguments apply only if the feature is 5465 enabled. In this case, ``--with-gtk3`` is added to the configure 5466 script argument list and ``gtk+3`` is added to :term:`DEPENDS`. On the 5467 other hand, if the feature is disabled say through a ``.bbappend`` 5468 file in another layer, then the second argument ``--without-gtk3`` is 5469 added to the configure script instead. 5470 5471 The basic :term:`PACKAGECONFIG` structure previously described holds true 5472 regardless of whether you are creating a block or changing a block. 5473 When creating a block, use the structure inside your recipe. 5474 5475 If you want to change an existing :term:`PACKAGECONFIG` block, you can do 5476 so one of two ways: 5477 5478 - *Append file:* Create an append file named 5479 ``recipename.bbappend`` in your layer and override the value of 5480 :term:`PACKAGECONFIG`. You can either completely override the 5481 variable:: 5482 5483 PACKAGECONFIG = "f4 f5" 5484 5485 Or, you can just append the variable:: 5486 5487 PACKAGECONFIG:append = " f4" 5488 5489 - *Configuration file:* This method is identical to changing the 5490 block through an append file except you edit your ``local.conf`` 5491 or ``mydistro.conf`` file. As with append files previously 5492 described, you can either completely override the variable:: 5493 5494 PACKAGECONFIG:pn-recipename = "f4 f5" 5495 5496 Or, you can just amend the variable:: 5497 5498 PACKAGECONFIG:append:pn-recipename = " f4" 5499 5500 :term:`PACKAGECONFIG_CONFARGS` 5501 A space-separated list of configuration options generated from the 5502 :term:`PACKAGECONFIG` setting. 5503 5504 Classes such as :ref:`autotools <ref-classes-autotools>` and 5505 :ref:`cmake <ref-classes-cmake>` use :term:`PACKAGECONFIG_CONFARGS` to 5506 pass :term:`PACKAGECONFIG` options to ``configure`` and ``cmake``, 5507 respectively. If you are using :term:`PACKAGECONFIG` but not a class that 5508 handles the ``do_configure`` task, then you need to use 5509 :term:`PACKAGECONFIG_CONFARGS` appropriately. 5510 5511 :term:`PACKAGEGROUP_DISABLE_COMPLEMENTARY` 5512 For recipes inheriting the 5513 :ref:`packagegroup <ref-classes-packagegroup>` class, setting 5514 :term:`PACKAGEGROUP_DISABLE_COMPLEMENTARY` to "1" specifies that the 5515 normal complementary packages (i.e. ``-dev``, ``-dbg``, and so forth) 5516 should not be automatically created by the ``packagegroup`` recipe, 5517 which is the default behavior. 5518 5519 :term:`PACKAGES` 5520 The list of packages the recipe creates. The default value is the 5521 following:: 5522 5523 ${PN}-src ${PN}-dbg ${PN}-staticdev ${PN}-dev ${PN}-doc ${PN}-locale ${PACKAGE_BEFORE_PN} ${PN} 5524 5525 During packaging, the :ref:`ref-tasks-package` task 5526 goes through :term:`PACKAGES` and uses the :term:`FILES` 5527 variable corresponding to each package to assign files to the 5528 package. If a file matches the :term:`FILES` variable for more than one 5529 package in :term:`PACKAGES`, it will be assigned to the earliest 5530 (leftmost) package. 5531 5532 Packages in the variable's list that are empty (i.e. where none of 5533 the patterns in ``FILES:``\ pkg match any files installed by the 5534 :ref:`ref-tasks-install` task) are not generated, 5535 unless generation is forced through the 5536 :term:`ALLOW_EMPTY` variable. 5537 5538 :term:`PACKAGES_DYNAMIC` 5539 A promise that your recipe satisfies runtime dependencies for 5540 optional modules that are found in other recipes. 5541 :term:`PACKAGES_DYNAMIC` does not actually satisfy the dependencies, it 5542 only states that they should be satisfied. For example, if a hard, 5543 runtime dependency (:term:`RDEPENDS`) of another 5544 package is satisfied at build time through the :term:`PACKAGES_DYNAMIC` 5545 variable, but a package with the module name is never actually 5546 produced, then the other package will be broken. Thus, if you attempt 5547 to include that package in an image, you will get a dependency 5548 failure from the packaging system during the 5549 :ref:`ref-tasks-rootfs` task. 5550 5551 Typically, if there is a chance that such a situation can occur and 5552 the package that is not created is valid without the dependency being 5553 satisfied, then you should use :term:`RRECOMMENDS` 5554 (a soft runtime dependency) instead of :term:`RDEPENDS`. 5555 5556 For an example of how to use the :term:`PACKAGES_DYNAMIC` variable when 5557 you are splitting packages, see the 5558 ":ref:`dev-manual/common-tasks:handling optional module packaging`" 5559 section in the Yocto Project Development Tasks Manual. 5560 5561 :term:`PACKAGESPLITFUNCS` 5562 Specifies a list of functions run to perform additional splitting of 5563 files into individual packages. Recipes can either prepend to this 5564 variable or prepend to the ``populate_packages`` function in order to 5565 perform additional package splitting. In either case, the function 5566 should set :term:`PACKAGES`, 5567 :term:`FILES`, :term:`RDEPENDS` and 5568 other packaging variables appropriately in order to perform the 5569 desired splitting. 5570 5571 :term:`PARALLEL_MAKE` 5572 Extra options passed to the ``make`` command during the 5573 :ref:`ref-tasks-compile` task in order to specify 5574 parallel compilation on the local build host. This variable is 5575 usually in the form "-j x", where x represents the maximum number of 5576 parallel threads ``make`` can run. 5577 5578 .. note:: 5579 5580 In order for :term:`PARALLEL_MAKE` to be effective, ``make`` must be 5581 called with ``${``\ :term:`EXTRA_OEMAKE`\ ``}``. An easy way to ensure 5582 this is to use the ``oe_runmake`` function. 5583 5584 By default, the OpenEmbedded build system automatically sets this 5585 variable to be equal to the number of cores the build system uses. 5586 5587 .. note:: 5588 5589 If the software being built experiences dependency issues during 5590 the ``do_compile`` task that result in race conditions, you can clear 5591 the :term:`PARALLEL_MAKE` variable within the recipe as a workaround. For 5592 information on addressing race conditions, see the 5593 ":ref:`dev-manual/common-tasks:debugging parallel make races`" 5594 section in the Yocto Project Development Tasks Manual. 5595 5596 For single socket systems (i.e. one CPU), you should not have to 5597 override this variable to gain optimal parallelism during builds. 5598 However, if you have very large systems that employ multiple physical 5599 CPUs, you might want to make sure the :term:`PARALLEL_MAKE` variable is 5600 not set higher than "-j 20". 5601 5602 For more information on speeding up builds, see the 5603 ":ref:`dev-manual/common-tasks:speeding up a build`" 5604 section in the Yocto Project Development Tasks Manual. 5605 5606 :term:`PARALLEL_MAKEINST` 5607 Extra options passed to the ``make install`` command during the 5608 :ref:`ref-tasks-install` task in order to specify 5609 parallel installation. This variable defaults to the value of 5610 :term:`PARALLEL_MAKE`. 5611 5612 .. note:: 5613 5614 In order for :term:`PARALLEL_MAKEINST` to be effective, ``make`` must 5615 be called with 5616 ``${``\ :term:`EXTRA_OEMAKE`\ ``}``. An easy 5617 way to ensure this is to use the ``oe_runmake`` function. 5618 5619 If the software being built experiences dependency issues during 5620 the ``do_install`` task that result in race conditions, you can 5621 clear the :term:`PARALLEL_MAKEINST` variable within the recipe as a 5622 workaround. For information on addressing race conditions, see the 5623 ":ref:`dev-manual/common-tasks:debugging parallel make races`" 5624 section in the Yocto Project Development Tasks Manual. 5625 5626 :term:`PATCHRESOLVE` 5627 Determines the action to take when a patch fails. You can set this 5628 variable to one of two values: "noop" and "user". 5629 5630 The default value of "noop" causes the build to simply fail when the 5631 OpenEmbedded build system cannot successfully apply a patch. Setting 5632 the value to "user" causes the build system to launch a shell and 5633 places you in the right location so that you can manually resolve the 5634 conflicts. 5635 5636 Set this variable in your ``local.conf`` file. 5637 5638 :term:`PATCHTOOL` 5639 Specifies the utility used to apply patches for a recipe during the 5640 :ref:`ref-tasks-patch` task. You can specify one of 5641 three utilities: "patch", "quilt", or "git". The default utility used 5642 is "quilt" except for the quilt-native recipe itself. Because the 5643 quilt tool is not available at the time quilt-native is being 5644 patched, it uses "patch". 5645 5646 If you wish to use an alternative patching tool, set the variable in 5647 the recipe using one of the following:: 5648 5649 PATCHTOOL = "patch" 5650 PATCHTOOL = "quilt" 5651 PATCHTOOL = "git" 5652 5653 :term:`PE` 5654 The epoch of the recipe. By default, this variable is unset. The 5655 variable is used to make upgrades possible when the versioning scheme 5656 changes in some backwards incompatible way. 5657 5658 :term:`PE` is the default value of the :term:`PKGE` variable. 5659 5660 :term:`PEP517_BUILD_API` 5661 When used by recipes that inherit the :ref:`python_pep517 5662 <ref-classes-python_pep517>` class, specifies the entry point to the 5663 PEP-517 compliant build API (such as ``flit_core.buildapi``). 5664 5665 :term:`PEP517_WHEEL_PATH` 5666 When used by recipes that inherit the 5667 :ref:`python_pep517 <ref-classes-python_pep517>` class, 5668 denotes the path to ``dist/`` (short for distribution) where the 5669 binary archive ``wheel`` is built. 5670 5671 :term:`PF` 5672 Specifies the recipe or package name and includes all version and 5673 revision numbers (i.e. ``glibc-2.13-r20+svnr15508/`` and 5674 ``bash-4.2-r1/``). This variable is comprised of the following: 5675 ${:term:`PN`}-${:term:`EXTENDPE`}${:term:`PV`}-${:term:`PR`} 5676 5677 :term:`PIXBUF_PACKAGES` 5678 When inheriting the :ref:`pixbufcache <ref-classes-pixbufcache>` 5679 class, this variable identifies packages that contain the pixbuf 5680 loaders used with ``gdk-pixbuf``. By default, the ``pixbufcache`` 5681 class assumes that the loaders are in the recipe's main package (i.e. 5682 ``${``\ :term:`PN`\ ``}``). Use this variable if the 5683 loaders you need are in a package other than that main package. 5684 5685 :term:`PKG` 5686 The name of the resulting package created by the OpenEmbedded build 5687 system. 5688 5689 .. note:: 5690 5691 When using the :term:`PKG` variable, you must use a package name override. 5692 5693 For example, when the :ref:`debian <ref-classes-debian>` class 5694 renames the output package, it does so by setting 5695 ``PKG:packagename``. 5696 5697 :term:`PKG_CONFIG_PATH` 5698 The path to ``pkg-config`` files for the current build context. 5699 ``pkg-config`` reads this variable from the environment. 5700 5701 :term:`PKGD` 5702 Points to the destination directory for files to be packaged before 5703 they are split into individual packages. This directory defaults to 5704 the following:: 5705 5706 ${WORKDIR}/package 5707 5708 Do not change this default. 5709 5710 :term:`PKGDATA_DIR` 5711 Points to a shared, global-state directory that holds data generated 5712 during the packaging process. During the packaging process, the 5713 :ref:`ref-tasks-packagedata` task packages data 5714 for each recipe and installs it into this temporary, shared area. 5715 This directory defaults to the following, which you should not 5716 change:: 5717 5718 ${STAGING_DIR_HOST}/pkgdata 5719 5720 For examples of how this data is used, see the 5721 ":ref:`overview-manual/concepts:automatically added runtime dependencies`" 5722 section in the Yocto Project Overview and Concepts Manual and the 5723 ":ref:`dev-manual/common-tasks:viewing package information with \`\`oe-pkgdata-util\`\``" 5724 section in the Yocto Project Development Tasks Manual. For more 5725 information on the shared, global-state directory, see 5726 :term:`STAGING_DIR_HOST`. 5727 5728 :term:`PKGDEST` 5729 Points to the parent directory for files to be packaged after they 5730 have been split into individual packages. This directory defaults to 5731 the following:: 5732 5733 ${WORKDIR}/packages-split 5734 5735 Under this directory, the build system creates directories for each 5736 package specified in :term:`PACKAGES`. Do not change 5737 this default. 5738 5739 :term:`PKGDESTWORK` 5740 Points to a temporary work area where the 5741 :ref:`ref-tasks-package` task saves package metadata. 5742 The :term:`PKGDESTWORK` location defaults to the following:: 5743 5744 ${WORKDIR}/pkgdata 5745 5746 Do not change this default. 5747 5748 The :ref:`ref-tasks-packagedata` task copies the 5749 package metadata from :term:`PKGDESTWORK` to 5750 :term:`PKGDATA_DIR` to make it available globally. 5751 5752 :term:`PKGE` 5753 The epoch of the package(s) built by the recipe. By default, :term:`PKGE` 5754 is set to :term:`PE`. 5755 5756 :term:`PKGR` 5757 The revision of the package(s) built by the recipe. By default, 5758 :term:`PKGR` is set to :term:`PR`. 5759 5760 :term:`PKGV` 5761 The version of the package(s) built by the recipe. By default, 5762 :term:`PKGV` is set to :term:`PV`. 5763 5764 :term:`PN` 5765 This variable can have two separate functions depending on the 5766 context: a recipe name or a resulting package name. 5767 5768 :term:`PN` refers to a recipe name in the context of a file used by the 5769 OpenEmbedded build system as input to create a package. The name is 5770 normally extracted from the recipe file name. For example, if the 5771 recipe is named ``expat_2.0.1.bb``, then the default value of :term:`PN` 5772 will be "expat". 5773 5774 The variable refers to a package name in the context of a file 5775 created or produced by the OpenEmbedded build system. 5776 5777 If applicable, the :term:`PN` variable also contains any special suffix 5778 or prefix. For example, using ``bash`` to build packages for the 5779 native machine, :term:`PN` is ``bash-native``. Using ``bash`` to build 5780 packages for the target and for Multilib, :term:`PN` would be ``bash`` 5781 and ``lib64-bash``, respectively. 5782 5783 :term:`POPULATE_SDK_POST_HOST_COMMAND` 5784 Specifies a list of functions to call once the OpenEmbedded build 5785 system has created the host part of the SDK. You can specify 5786 functions separated by semicolons:: 5787 5788 POPULATE_SDK_POST_HOST_COMMAND += "function; ... " 5789 5790 If you need to pass the SDK path to a command within a function, you 5791 can use ``${SDK_DIR}``, which points to the parent directory used by 5792 the OpenEmbedded build system when creating SDK output. See the 5793 :term:`SDK_DIR` variable for more information. 5794 5795 :term:`POPULATE_SDK_POST_TARGET_COMMAND` 5796 Specifies a list of functions to call once the OpenEmbedded build 5797 system has created the target part of the SDK. You can specify 5798 functions separated by semicolons:: 5799 5800 POPULATE_SDK_POST_TARGET_COMMAND += "function; ... " 5801 5802 If you need to pass the SDK path to a command within a function, you 5803 can use ``${SDK_DIR}``, which points to the parent directory used by 5804 the OpenEmbedded build system when creating SDK output. See the 5805 :term:`SDK_DIR` variable for more information. 5806 5807 :term:`PR` 5808 The revision of the recipe. The default value for this variable is 5809 "r0". Subsequent revisions of the recipe conventionally have the 5810 values "r1", "r2", and so forth. When :term:`PV` increases, 5811 :term:`PR` is conventionally reset to "r0". 5812 5813 .. note:: 5814 5815 The OpenEmbedded build system does not need the aid of :term:`PR` 5816 to know when to rebuild a recipe. The build system uses the task 5817 :ref:`input checksums <overview-manual/concepts:checksums (signatures)>` along with the 5818 :ref:`stamp <structure-build-tmp-stamps>` and 5819 :ref:`overview-manual/concepts:shared state cache` 5820 mechanisms. 5821 5822 The :term:`PR` variable primarily becomes significant when a package 5823 manager dynamically installs packages on an already built image. In 5824 this case, :term:`PR`, which is the default value of 5825 :term:`PKGR`, helps the package manager distinguish which 5826 package is the most recent one in cases where many packages have the 5827 same :term:`PV` (i.e. :term:`PKGV`). A component having many packages with 5828 the same :term:`PV` usually means that the packages all install the same 5829 upstream version, but with later (:term:`PR`) version packages including 5830 packaging fixes. 5831 5832 .. note:: 5833 5834 :term:`PR` does not need to be increased for changes that do not change the 5835 package contents or metadata. 5836 5837 Because manually managing :term:`PR` can be cumbersome and error-prone, 5838 an automated solution exists. See the 5839 ":ref:`dev-manual/common-tasks:working with a pr service`" section 5840 in the Yocto Project Development Tasks Manual for more information. 5841 5842 :term:`PREFERRED_PROVIDER` 5843 If multiple recipes provide the same item, this variable determines 5844 which recipe is preferred and thus provides the item (i.e. the 5845 preferred provider). You should always suffix this variable with the 5846 name of the provided item. And, you should define the variable using 5847 the preferred recipe's name (:term:`PN`). Here is a common 5848 example:: 5849 5850 PREFERRED_PROVIDER_virtual/kernel ?= "linux-yocto" 5851 5852 In the previous example, multiple recipes are providing "virtual/kernel". 5853 The :term:`PREFERRED_PROVIDER` variable is set with the name (:term:`PN`) of 5854 the recipe you prefer to provide "virtual/kernel". 5855 5856 Following are more examples:: 5857 5858 PREFERRED_PROVIDER_virtual/xserver = "xserver-xf86" 5859 PREFERRED_PROVIDER_virtual/libgl ?= "mesa" 5860 5861 For more 5862 information, see the ":ref:`dev-manual/common-tasks:using virtual providers`" 5863 section in the Yocto Project Development Tasks Manual. 5864 5865 .. note:: 5866 5867 If you use a ``virtual/\*`` item with :term:`PREFERRED_PROVIDER`, then any 5868 recipe that :term:`PROVIDES` that item but is not selected (defined) 5869 by :term:`PREFERRED_PROVIDER` is prevented from building, which is usually 5870 desirable since this mechanism is designed to select between mutually 5871 exclusive alternative providers. 5872 5873 :term:`PREFERRED_VERSION` 5874 If there are multiple versions of a recipe available, this variable 5875 determines which version should be given preference. You must always 5876 suffix the variable with the :term:`PN` you want to select (`python` in 5877 the first example below), and you should specify the :term:`PV` 5878 accordingly (`3.4.0` in the example). 5879 5880 The :term:`PREFERRED_VERSION` variable supports limited wildcard use 5881 through the "``%``" character. You can use the character to match any 5882 number of characters, which can be useful when specifying versions 5883 that contain long revision numbers that potentially change. Here are 5884 two examples:: 5885 5886 PREFERRED_VERSION_python = "3.4.0" 5887 PREFERRED_VERSION_linux-yocto = "5.0%" 5888 5889 .. note:: 5890 5891 The use of the "%" character is limited in that it only works at the end of the 5892 string. You cannot use the wildcard character in any other 5893 location of the string. 5894 5895 The specified version is matched against :term:`PV`, which 5896 does not necessarily match the version part of the recipe's filename. 5897 For example, consider two recipes ``foo_1.2.bb`` and ``foo_git.bb`` 5898 where ``foo_git.bb`` contains the following assignment:: 5899 5900 PV = "1.1+git${SRCPV}" 5901 5902 In this case, the correct way to select 5903 ``foo_git.bb`` is by using an assignment such as the following:: 5904 5905 PREFERRED_VERSION_foo = "1.1+git%" 5906 5907 Compare that previous example 5908 against the following incorrect example, which does not work:: 5909 5910 PREFERRED_VERSION_foo = "git" 5911 5912 Sometimes the :term:`PREFERRED_VERSION` variable can be set by 5913 configuration files in a way that is hard to change. You can use 5914 :term:`OVERRIDES` to set a machine-specific 5915 override. Here is an example:: 5916 5917 PREFERRED_VERSION_linux-yocto:qemux86 = "5.0%" 5918 5919 Although not recommended, worst case, you can also use the 5920 "forcevariable" override, which is the strongest override possible. 5921 Here is an example:: 5922 5923 PREFERRED_VERSION_linux-yocto:forcevariable = "5.0%" 5924 5925 .. note:: 5926 5927 The ``:forcevariable`` override is not handled specially. This override 5928 only works because the default value of :term:`OVERRIDES` includes "forcevariable". 5929 5930 If a recipe with the specified version is not available, a warning 5931 message will be shown. See :term:`REQUIRED_VERSION` if you want this 5932 to be an error instead. 5933 5934 :term:`PREMIRRORS` 5935 Specifies additional paths from which the OpenEmbedded build system 5936 gets source code. When the build system searches for source code, it 5937 first tries the local download directory. If that location fails, the 5938 build system tries locations defined by :term:`PREMIRRORS`, the upstream 5939 source, and then locations specified by 5940 :term:`MIRRORS` in that order. 5941 5942 Assuming your distribution (:term:`DISTRO`) is "poky", 5943 the default value for :term:`PREMIRRORS` is defined in the 5944 ``conf/distro/poky.conf`` file in the ``meta-poky`` Git repository. 5945 5946 Typically, you could add a specific server for the build system to 5947 attempt before any others by adding something like the following to 5948 the ``local.conf`` configuration file in the 5949 :term:`Build Directory`:: 5950 5951 PREMIRRORS:prepend = "\ 5952 git://.*/.* &YOCTO_DL_URL;/mirror/sources/ \ 5953 ftp://.*/.* &YOCTO_DL_URL;/mirror/sources/ \ 5954 http://.*/.* &YOCTO_DL_URL;/mirror/sources/ \ 5955 https://.*/.* &YOCTO_DL_URL;/mirror/sources/" 5956 5957 These changes cause the 5958 build system to intercept Git, FTP, HTTP, and HTTPS requests and 5959 direct them to the ``http://`` sources mirror. You can use 5960 ``file://`` URLs to point to local directories or network shares as 5961 well. 5962 5963 :term:`PRIORITY` 5964 Indicates the importance of a package. 5965 5966 :term:`PRIORITY` is considered to be part of the distribution policy 5967 because the importance of any given recipe depends on the purpose for 5968 which the distribution is being produced. Thus, :term:`PRIORITY` is not 5969 normally set within recipes. 5970 5971 You can set :term:`PRIORITY` to "required", "standard", "extra", and 5972 "optional", which is the default. 5973 5974 :term:`PRIVATE_LIBS` 5975 Specifies libraries installed within a recipe that should be ignored 5976 by the OpenEmbedded build system's shared library resolver. This 5977 variable is typically used when software being built by a recipe has 5978 its own private versions of a library normally provided by another 5979 recipe. In this case, you would not want the package containing the 5980 private libraries to be set as a dependency on other unrelated 5981 packages that should instead depend on the package providing the 5982 standard version of the library. 5983 5984 Libraries specified in this variable should be specified by their 5985 file name. For example, from the Firefox recipe in meta-browser:: 5986 5987 PRIVATE_LIBS = "libmozjs.so \ 5988 libxpcom.so \ 5989 libnspr4.so \ 5990 libxul.so \ 5991 libmozalloc.so \ 5992 libplc4.so \ 5993 libplds4.so" 5994 5995 For more information, see the 5996 ":ref:`overview-manual/concepts:automatically added runtime dependencies`" 5997 section in the Yocto Project Overview and Concepts Manual. 5998 5999 :term:`PROVIDES` 6000 A list of aliases by which a particular recipe can be known. By 6001 default, a recipe's own :term:`PN` is implicitly already in its 6002 :term:`PROVIDES` list and therefore does not need to mention that it 6003 provides itself. If a recipe uses :term:`PROVIDES`, the additional 6004 aliases are synonyms for the recipe and can be useful for satisfying 6005 dependencies of other recipes during the build as specified by 6006 :term:`DEPENDS`. 6007 6008 Consider the following example :term:`PROVIDES` statement from the recipe 6009 file ``eudev_3.2.9.bb``:: 6010 6011 PROVIDES += "udev" 6012 6013 The :term:`PROVIDES` statement 6014 results in the "eudev" recipe also being available as simply "udev". 6015 6016 .. note:: 6017 6018 A recipe's own recipe name (:term:`PN`) is always implicitly prepended 6019 to `PROVIDES`, so while using "+=" in the above example may not be 6020 strictly necessary it is recommended to avoid confusion. 6021 6022 In addition to providing recipes under alternate names, the 6023 :term:`PROVIDES` mechanism is also used to implement virtual targets. A 6024 virtual target is a name that corresponds to some particular 6025 functionality (e.g. a Linux kernel). Recipes that provide the 6026 functionality in question list the virtual target in :term:`PROVIDES`. 6027 Recipes that depend on the functionality in question can include the 6028 virtual target in :term:`DEPENDS` to leave the choice of provider open. 6029 6030 Conventionally, virtual targets have names on the form 6031 "virtual/function" (e.g. "virtual/kernel"). The slash is simply part 6032 of the name and has no syntactical significance. 6033 6034 The :term:`PREFERRED_PROVIDER` variable is 6035 used to select which particular recipe provides a virtual target. 6036 6037 .. note:: 6038 6039 A corresponding mechanism for virtual runtime dependencies 6040 (packages) exists. However, the mechanism does not depend on any 6041 special functionality beyond ordinary variable assignments. For 6042 example, ``VIRTUAL-RUNTIME_dev_manager`` refers to the package of 6043 the component that manages the ``/dev`` directory. 6044 6045 Setting the "preferred provider" for runtime dependencies is as 6046 simple as using the following assignment in a configuration file:: 6047 6048 VIRTUAL-RUNTIME_dev_manager = "udev" 6049 6050 6051 :term:`PRSERV_HOST` 6052 The network based :term:`PR` service host and port. 6053 6054 The ``conf/local.conf.sample.extended`` configuration file in the 6055 :term:`Source Directory` shows how the 6056 :term:`PRSERV_HOST` variable is set:: 6057 6058 PRSERV_HOST = "localhost:0" 6059 6060 You must 6061 set the variable if you want to automatically start a local :ref:`PR 6062 service <dev-manual/common-tasks:working with a pr service>`. You can 6063 set :term:`PRSERV_HOST` to other values to use a remote PR service. 6064 6065 6066 :term:`PSEUDO_IGNORE_PATHS` 6067 A comma-separated (without spaces) list of path prefixes that should be ignored 6068 by pseudo when monitoring and recording file operations, in order to avoid 6069 problems with files being written to outside of the pseudo context and 6070 reduce pseudo's overhead. A path is ignored if it matches any prefix in the list 6071 and can include partial directory (or file) names. 6072 6073 6074 :term:`PTEST_ENABLED` 6075 Specifies whether or not :ref:`Package 6076 Test <dev-manual/common-tasks:testing packages with ptest>` (ptest) 6077 functionality is enabled when building a recipe. You should not set 6078 this variable directly. Enabling and disabling building Package Tests 6079 at build time should be done by adding "ptest" to (or removing it 6080 from) :term:`DISTRO_FEATURES`. 6081 6082 :term:`PV` 6083 The version of the recipe. The version is normally extracted from the 6084 recipe filename. For example, if the recipe is named 6085 ``expat_2.0.1.bb``, then the default value of :term:`PV` will be "2.0.1". 6086 :term:`PV` is generally not overridden within a recipe unless it is 6087 building an unstable (i.e. development) version from a source code 6088 repository (e.g. Git or Subversion). 6089 6090 :term:`PV` is the default value of the :term:`PKGV` variable. 6091 6092 :term:`PYTHON_ABI` 6093 When used by recipes that inherit the 6094 :ref:`setuptools3 <ref-classes-setuptools3>` class, denotes the 6095 Application Binary Interface (ABI) currently in use for Python. By 6096 default, the ABI is "m". You do not have to set this variable as the 6097 OpenEmbedded build system sets it for you. 6098 6099 The OpenEmbedded build system uses the ABI to construct directory 6100 names used when installing the Python headers and libraries in 6101 sysroot (e.g. ``.../python3.3m/...``). 6102 6103 :term:`PYTHON_PN` 6104 When used by recipes that inherit the 6105 :ref:`setuptools3 <ref-classes-setuptools3>` classe, specifies the 6106 major Python version being built. For Python 3.x, :term:`PYTHON_PN` would 6107 be "python3". You do not have to set this variable as the 6108 OpenEmbedded build system automatically sets it for you. 6109 6110 The variable allows recipes to use common infrastructure such as the 6111 following:: 6112 6113 DEPENDS += "${PYTHON_PN}-native" 6114 6115 In the previous example, 6116 the version of the dependency is :term:`PYTHON_PN`. 6117 6118 :term:`QA_EMPTY_DIRS` 6119 Specifies a list of directories that are expected to be empty when 6120 packaging; if ``empty-dirs`` appears in :term:`ERROR_QA` or 6121 :term:`WARN_QA` these will be checked and an error or warning 6122 (respectively) will be produced. 6123 6124 The default :term:`QA_EMPTY_DIRS` value is set in 6125 :ref:`insane.bbclass <ref-classes-insane>`. 6126 6127 :term:`QA_EMPTY_DIRS_RECOMMENDATION` 6128 Specifies a recommendation for why a directory must be empty, 6129 which will be included in the error message if a specific directory 6130 is found to contain files. Must be overridden with the directory 6131 path to match on. 6132 6133 If no recommendation is specified for a directory, then the default 6134 "but it is expected to be empty" will be used. 6135 6136 An example message shows if files were present in '/dev':: 6137 6138 QA_EMPTY_DIRS_RECOMMENDATION:/dev = "but all devices must be created at runtime" 6139 6140 :term:`RANLIB` 6141 The minimal command and arguments to run ``ranlib``. 6142 6143 :term:`RCONFLICTS` 6144 The list of packages that conflict with packages. Note that packages 6145 will not be installed if conflicting packages are not first removed. 6146 6147 Like all package-controlling variables, you must always use them in 6148 conjunction with a package name override. Here is an example:: 6149 6150 RCONFLICTS:${PN} = "another_conflicting_package_name" 6151 6152 BitBake, which the OpenEmbedded build system uses, supports 6153 specifying versioned dependencies. Although the syntax varies 6154 depending on the packaging format, BitBake hides these differences 6155 from you. Here is the general syntax to specify versions with the 6156 :term:`RCONFLICTS` variable:: 6157 6158 RCONFLICTS:${PN} = "package (operator version)" 6159 6160 For ``operator``, you can specify the following: 6161 6162 - = 6163 - < 6164 - > 6165 - <= 6166 - >= 6167 6168 For example, the following sets up a dependency on version 1.2 or 6169 greater of the package ``foo``:: 6170 6171 RCONFLICTS:${PN} = "foo (>= 1.2)" 6172 6173 :term:`RDEPENDS` 6174 Lists runtime dependencies of a package. These dependencies are other 6175 packages that must be installed in order for the package to function 6176 correctly. As an example, the following assignment declares that the 6177 package ``foo`` needs the packages ``bar`` and ``baz`` to be 6178 installed:: 6179 6180 RDEPENDS:foo = "bar baz" 6181 6182 The most common types of package 6183 runtime dependencies are automatically detected and added. Therefore, 6184 most recipes do not need to set :term:`RDEPENDS`. For more information, 6185 see the 6186 ":ref:`overview-manual/concepts:automatically added runtime dependencies`" 6187 section in the Yocto Project Overview and Concepts Manual. 6188 6189 The practical effect of the above :term:`RDEPENDS` assignment is that 6190 ``bar`` and ``baz`` will be declared as dependencies inside the 6191 package ``foo`` when it is written out by one of the 6192 :ref:`do_package_write_\* <ref-tasks-package_write_deb>` tasks. 6193 Exactly how this is done depends on which package format is used, 6194 which is determined by 6195 :term:`PACKAGE_CLASSES`. When the 6196 corresponding package manager installs the package, it will know to 6197 also install the packages on which it depends. 6198 6199 To ensure that the packages ``bar`` and ``baz`` get built, the 6200 previous :term:`RDEPENDS` assignment also causes a task dependency to be 6201 added. This dependency is from the recipe's 6202 :ref:`ref-tasks-build` (not to be confused with 6203 :ref:`ref-tasks-compile`) task to the 6204 ``do_package_write_*`` task of the recipes that build ``bar`` and 6205 ``baz``. 6206 6207 The names of the packages you list within :term:`RDEPENDS` must be the 6208 names of other packages - they cannot be recipe names. Although 6209 package names and recipe names usually match, the important point 6210 here is that you are providing package names within the :term:`RDEPENDS` 6211 variable. For an example of the default list of packages created from 6212 a recipe, see the :term:`PACKAGES` variable. 6213 6214 Because the :term:`RDEPENDS` variable applies to packages being built, 6215 you should always use the variable in a form with an attached package 6216 name (remember that a single recipe can build multiple packages). For 6217 example, suppose you are building a development package that depends 6218 on the ``perl`` package. In this case, you would use the following 6219 :term:`RDEPENDS` statement:: 6220 6221 RDEPENDS:${PN}-dev += "perl" 6222 6223 In the example, 6224 the development package depends on the ``perl`` package. Thus, the 6225 :term:`RDEPENDS` variable has the ``${PN}-dev`` package name as part of 6226 the variable. 6227 6228 .. note:: 6229 6230 ``RDEPENDS:${PN}-dev`` includes ``${``\ :term:`PN`\ ``}`` 6231 by default. This default is set in the BitBake configuration file 6232 (``meta/conf/bitbake.conf``). Be careful not to accidentally remove 6233 ``${PN}`` when modifying ``RDEPENDS:${PN}-dev``. Use the "+=" operator 6234 rather than the "=" operator. 6235 6236 The package names you use with :term:`RDEPENDS` must appear as they would 6237 in the :term:`PACKAGES` variable. The :term:`PKG` variable 6238 allows a different name to be used for the final package (e.g. the 6239 :ref:`debian <ref-classes-debian>` class uses this to rename 6240 packages), but this final package name cannot be used with 6241 :term:`RDEPENDS`, which makes sense as :term:`RDEPENDS` is meant to be 6242 independent of the package format used. 6243 6244 BitBake, which the OpenEmbedded build system uses, supports 6245 specifying versioned dependencies. Although the syntax varies 6246 depending on the packaging format, BitBake hides these differences 6247 from you. Here is the general syntax to specify versions with the 6248 :term:`RDEPENDS` variable:: 6249 6250 RDEPENDS:${PN} = "package (operator version)" 6251 6252 For ``operator``, you can specify the following: 6253 6254 - = 6255 - < 6256 - > 6257 - <= 6258 - >= 6259 6260 For version, provide the version number. 6261 6262 .. note:: 6263 6264 You can use :term:`EXTENDPKGV` to provide a full package version 6265 specification. 6266 6267 For example, the following sets up a dependency on version 1.2 or 6268 greater of the package ``foo``:: 6269 6270 RDEPENDS:${PN} = "foo (>= 1.2)" 6271 6272 For information on build-time dependencies, see the 6273 :term:`DEPENDS` variable. You can also see the 6274 ":ref:`bitbake:bitbake-user-manual/bitbake-user-manual-metadata:tasks`" and 6275 ":ref:`bitbake:bitbake-user-manual/bitbake-user-manual-execution:dependencies`" sections in the 6276 BitBake User Manual for additional information on tasks and 6277 dependencies. 6278 6279 :term:`RECIPE_NO_UPDATE_REASON` 6280 If a recipe should not be replaced by a more recent upstream version, 6281 putting the reason why in this variable in a recipe allows 6282 ``devtool check-upgrade-status`` command to display it, as explained 6283 in the ":ref:`ref-manual/devtool-reference:checking on the upgrade status of a recipe`" 6284 section. 6285 6286 :term:`REQUIRED_DISTRO_FEATURES` 6287 When inheriting the 6288 :ref:`features_check <ref-classes-features_check>` 6289 class, this variable identifies distribution features that must exist 6290 in the current configuration in order for the OpenEmbedded build 6291 system to build the recipe. In other words, if the 6292 :term:`REQUIRED_DISTRO_FEATURES` variable lists a feature that does not 6293 appear in :term:`DISTRO_FEATURES` within the current configuration, then 6294 the recipe will be skipped, and if the build system attempts to build 6295 the recipe then an error will be triggered. 6296 6297 :term:`REQUIRED_VERSION` 6298 If there are multiple versions of a recipe available, this variable 6299 determines which version should be given preference. 6300 :term:`REQUIRED_VERSION` works in exactly the same manner as 6301 :term:`PREFERRED_VERSION`, except that if the specified version is not 6302 available then an error message is shown and the build fails 6303 immediately. 6304 6305 If both :term:`REQUIRED_VERSION` and :term:`PREFERRED_VERSION` are set 6306 for the same recipe, the :term:`REQUIRED_VERSION` value applies. 6307 6308 :term:`RM_WORK_EXCLUDE` 6309 With ``rm_work`` enabled, this variable specifies a list of recipes 6310 whose work directories should not be removed. See the 6311 ":ref:`ref-classes-rm-work`" section for more 6312 details. 6313 6314 :term:`ROOT_HOME` 6315 Defines the root home directory. By default, this directory is set as 6316 follows in the BitBake configuration file:: 6317 6318 ROOT_HOME ??= "/home/root" 6319 6320 .. note:: 6321 6322 This default value is likely used because some embedded solutions 6323 prefer to have a read-only root filesystem and prefer to keep 6324 writeable data in one place. 6325 6326 You can override the default by setting the variable in any layer or 6327 in the ``local.conf`` file. Because the default is set using a "weak" 6328 assignment (i.e. "??="), you can use either of the following forms to 6329 define your override:: 6330 6331 ROOT_HOME = "/root" 6332 ROOT_HOME ?= "/root" 6333 6334 These 6335 override examples use ``/root``, which is probably the most commonly 6336 used override. 6337 6338 :term:`ROOTFS` 6339 Indicates a filesystem image to include as the root filesystem. 6340 6341 The :term:`ROOTFS` variable is an optional variable used with the 6342 :ref:`image-live <ref-classes-image-live>` class. 6343 6344 :term:`ROOTFS_POSTINSTALL_COMMAND` 6345 Specifies a list of functions to call after the OpenEmbedded build 6346 system has installed packages. You can specify functions separated by 6347 semicolons:: 6348 6349 ROOTFS_POSTINSTALL_COMMAND += "function; ... " 6350 6351 If you need to pass the root filesystem path to a command within a 6352 function, you can use ``${IMAGE_ROOTFS}``, which points to the 6353 directory that becomes the root filesystem image. See the 6354 :term:`IMAGE_ROOTFS` variable for more 6355 information. 6356 6357 :term:`ROOTFS_POSTPROCESS_COMMAND` 6358 Specifies a list of functions to call once the OpenEmbedded build 6359 system has created the root filesystem. You can specify functions 6360 separated by semicolons:: 6361 6362 ROOTFS_POSTPROCESS_COMMAND += "function; ... " 6363 6364 If you need to pass the root filesystem path to a command within a 6365 function, you can use ``${IMAGE_ROOTFS}``, which points to the 6366 directory that becomes the root filesystem image. See the 6367 :term:`IMAGE_ROOTFS` variable for more 6368 information. 6369 6370 :term:`ROOTFS_POSTUNINSTALL_COMMAND` 6371 Specifies a list of functions to call after the OpenEmbedded build 6372 system has removed unnecessary packages. When runtime package 6373 management is disabled in the image, several packages are removed 6374 including ``base-passwd``, ``shadow``, and ``update-alternatives``. 6375 You can specify functions separated by semicolons:: 6376 6377 ROOTFS_POSTUNINSTALL_COMMAND += "function; ... " 6378 6379 If you need to pass the root filesystem path to a command within a 6380 function, you can use ``${IMAGE_ROOTFS}``, which points to the 6381 directory that becomes the root filesystem image. See the 6382 :term:`IMAGE_ROOTFS` variable for more 6383 information. 6384 6385 :term:`ROOTFS_PREPROCESS_COMMAND` 6386 Specifies a list of functions to call before the OpenEmbedded build 6387 system has created the root filesystem. You can specify functions 6388 separated by semicolons:: 6389 6390 ROOTFS_PREPROCESS_COMMAND += "function; ... " 6391 6392 If you need to pass the root filesystem path to a command within a 6393 function, you can use ``${IMAGE_ROOTFS}``, which points to the 6394 directory that becomes the root filesystem image. See the 6395 :term:`IMAGE_ROOTFS` variable for more 6396 information. 6397 6398 :term:`RPROVIDES` 6399 A list of package name aliases that a package also provides. These 6400 aliases are useful for satisfying runtime dependencies of other 6401 packages both during the build and on the target (as specified by 6402 :term:`RDEPENDS`). 6403 6404 .. note:: 6405 6406 A package's own name is implicitly already in its :term:`RPROVIDES` list. 6407 6408 As with all package-controlling variables, you must always use the 6409 variable in conjunction with a package name override. Here is an 6410 example:: 6411 6412 RPROVIDES:${PN} = "widget-abi-2" 6413 6414 :term:`RRECOMMENDS` 6415 A list of packages that extends the usability of a package being 6416 built. The package being built does not depend on this list of 6417 packages in order to successfully build, but rather uses them for 6418 extended usability. To specify runtime dependencies for packages, see 6419 the :term:`RDEPENDS` variable. 6420 6421 The package manager will automatically install the :term:`RRECOMMENDS` 6422 list of packages when installing the built package. However, you can 6423 prevent listed packages from being installed by using the 6424 :term:`BAD_RECOMMENDATIONS`, 6425 :term:`NO_RECOMMENDATIONS`, and 6426 :term:`PACKAGE_EXCLUDE` variables. 6427 6428 Packages specified in :term:`RRECOMMENDS` need not actually be produced. 6429 However, there must be a recipe providing each package, either 6430 through the :term:`PACKAGES` or 6431 :term:`PACKAGES_DYNAMIC` variables or the 6432 :term:`RPROVIDES` variable, or an error will occur 6433 during the build. If such a recipe does exist and the package is not 6434 produced, the build continues without error. 6435 6436 Because the :term:`RRECOMMENDS` variable applies to packages being built, 6437 you should always attach an override to the variable to specify the 6438 particular package whose usability is being extended. For example, 6439 suppose you are building a development package that is extended to 6440 support wireless functionality. In this case, you would use the 6441 following:: 6442 6443 RRECOMMENDS:${PN}-dev += "wireless_package_name" 6444 6445 In the 6446 example, the package name (``${PN}-dev``) must appear as it would in 6447 the :term:`PACKAGES` namespace before any renaming of the output package 6448 by classes such as :ref:`ref-classes-debian`. 6449 6450 BitBake, which the OpenEmbedded build system uses, supports 6451 specifying versioned recommends. Although the syntax varies depending 6452 on the packaging format, BitBake hides these differences from you. 6453 Here is the general syntax to specify versions with the 6454 :term:`RRECOMMENDS` variable:: 6455 6456 RRECOMMENDS:${PN} = "package (operator version)" 6457 6458 For ``operator``, you can specify the following: 6459 6460 - = 6461 - < 6462 - > 6463 - <= 6464 - >= 6465 6466 For example, the following sets up a recommend on version 1.2 or 6467 greater of the package ``foo``:: 6468 6469 RRECOMMENDS:${PN} = "foo (>= 1.2)" 6470 6471 :term:`RREPLACES` 6472 A list of packages replaced by a package. The package manager uses 6473 this variable to determine which package should be installed to 6474 replace other package(s) during an upgrade. In order to also have the 6475 other package(s) removed at the same time, you must add the name of 6476 the other package to the :term:`RCONFLICTS` variable. 6477 6478 As with all package-controlling variables, you must use this variable 6479 in conjunction with a package name override. Here is an example:: 6480 6481 RREPLACES:${PN} = "other_package_being_replaced" 6482 6483 BitBake, which the OpenEmbedded build system uses, supports 6484 specifying versioned replacements. Although the syntax varies 6485 depending on the packaging format, BitBake hides these differences 6486 from you. Here is the general syntax to specify versions with the 6487 :term:`RREPLACES` variable:: 6488 6489 RREPLACES:${PN} = "package (operator version)" 6490 6491 For ``operator``, you can specify the following: 6492 6493 - = 6494 - < 6495 - > 6496 - <= 6497 - >= 6498 6499 For example, the following sets up a replacement using version 1.2 6500 or greater of the package ``foo``:: 6501 6502 RREPLACES:${PN} = "foo (>= 1.2)" 6503 6504 :term:`RSUGGESTS` 6505 A list of additional packages that you can suggest for installation 6506 by the package manager at the time a package is installed. Not all 6507 package managers support this functionality. 6508 6509 As with all package-controlling variables, you must always use this 6510 variable in conjunction with a package name override. Here is an 6511 example:: 6512 6513 RSUGGESTS:${PN} = "useful_package another_package" 6514 6515 :term:`S` 6516 The location in the :term:`Build Directory` where 6517 unpacked recipe source code resides. By default, this directory is 6518 ``${``\ :term:`WORKDIR`\ ``}/${``\ :term:`BPN`\ ``}-${``\ :term:`PV`\ ``}``, 6519 where ``${BPN}`` is the base recipe name and ``${PV}`` is the recipe 6520 version. If the source tarball extracts the code to a directory named 6521 anything other than ``${BPN}-${PV}``, or if the source code is 6522 fetched from an SCM such as Git or Subversion, then you must set 6523 :term:`S` in the recipe so that the OpenEmbedded build system knows where 6524 to find the unpacked source. 6525 6526 As an example, assume a :term:`Source Directory` 6527 top-level folder named ``poky`` and a default Build Directory at 6528 ``poky/build``. In this case, the work directory the build system 6529 uses to keep the unpacked recipe for ``db`` is the following:: 6530 6531 poky/build/tmp/work/qemux86-poky-linux/db/5.1.19-r3/db-5.1.19 6532 6533 The unpacked source code resides in the ``db-5.1.19`` folder. 6534 6535 This next example assumes a Git repository. By default, Git 6536 repositories are cloned to ``${WORKDIR}/git`` during 6537 :ref:`ref-tasks-fetch`. Since this path is different 6538 from the default value of :term:`S`, you must set it specifically so the 6539 source can be located:: 6540 6541 SRC_URI = "git://path/to/repo.git;branch=main" 6542 S = "${WORKDIR}/git" 6543 6544 :term:`SANITY_REQUIRED_UTILITIES` 6545 Specifies a list of command-line utilities that should be checked for 6546 during the initial sanity checking process when running BitBake. If 6547 any of the utilities are not installed on the build host, then 6548 BitBake immediately exits with an error. 6549 6550 :term:`SANITY_TESTED_DISTROS` 6551 A list of the host distribution identifiers that the build system has 6552 been tested against. Identifiers consist of the host distributor ID 6553 followed by the release, as reported by the ``lsb_release`` tool or 6554 as read from ``/etc/lsb-release``. Separate the list items with 6555 explicit newline characters (``\n``). If :term:`SANITY_TESTED_DISTROS` is 6556 not empty and the current value of 6557 :term:`NATIVELSBSTRING` does not appear in the 6558 list, then the build system reports a warning that indicates the 6559 current host distribution has not been tested as a build host. 6560 6561 :term:`SDK_ARCH` 6562 The target architecture for the SDK. Typically, you do not directly 6563 set this variable. Instead, use :term:`SDKMACHINE`. 6564 6565 :term:`SDK_CUSTOM_TEMPLATECONF` 6566 When building the extensible SDK, if :term:`SDK_CUSTOM_TEMPLATECONF` is set to 6567 "1" and a ``conf/templateconf.conf`` file exists in the build directory 6568 (:term:`TOPDIR`) then this will be copied into the SDK. 6569 6570 :term:`SDK_DEPLOY` 6571 The directory set up and used by the 6572 :ref:`populate_sdk_base <ref-classes-populate-sdk>` class to which 6573 the SDK is deployed. The ``populate_sdk_base`` class defines 6574 :term:`SDK_DEPLOY` as follows:: 6575 6576 SDK_DEPLOY = "${TMPDIR}/deploy/sdk" 6577 6578 :term:`SDK_DIR` 6579 The parent directory used by the OpenEmbedded build system when 6580 creating SDK output. The 6581 :ref:`populate_sdk_base <ref-classes-populate-sdk-*>` class defines 6582 the variable as follows:: 6583 6584 SDK_DIR = "${WORKDIR}/sdk" 6585 6586 .. note:: 6587 6588 The :term:`SDK_DIR` directory is a temporary directory as it is part of 6589 :term:`WORKDIR`. The final output directory is :term:`SDK_DEPLOY`. 6590 6591 :term:`SDK_EXT_TYPE` 6592 Controls whether or not shared state artifacts are copied into the 6593 extensible SDK. The default value of "full" copies all of the 6594 required shared state artifacts into the extensible SDK. The value 6595 "minimal" leaves these artifacts out of the SDK. 6596 6597 .. note:: 6598 6599 If you set the variable to "minimal", you need to ensure 6600 :term:`SSTATE_MIRRORS` is set in the SDK's configuration to enable the 6601 artifacts to be fetched as needed. 6602 6603 :term:`SDK_HOST_MANIFEST` 6604 The manifest file for the host part of the SDK. This file lists all 6605 the installed packages that make up the host part of the SDK. The 6606 file contains package information on a line-per-package basis as 6607 follows:: 6608 6609 packagename packagearch version 6610 6611 The :ref:`populate_sdk_base <ref-classes-populate-sdk-*>` class 6612 defines the manifest file as follows:: 6613 6614 SDK_HOST_MANIFEST = "${SDK_DEPLOY}/${TOOLCHAIN_OUTPUTNAME}.host.manifest" 6615 6616 The location is derived using the :term:`SDK_DEPLOY` and 6617 :term:`TOOLCHAIN_OUTPUTNAME` variables. 6618 6619 :term:`SDK_INCLUDE_PKGDATA` 6620 When set to "1", specifies to include the packagedata for all recipes 6621 in the "world" target in the extensible SDK. Including this data 6622 allows the ``devtool search`` command to find these recipes in search 6623 results, as well as allows the ``devtool add`` command to map 6624 dependencies more effectively. 6625 6626 .. note:: 6627 6628 Enabling the :term:`SDK_INCLUDE_PKGDATA` 6629 variable significantly increases build time because all of world 6630 needs to be built. Enabling the variable also slightly increases 6631 the size of the extensible SDK. 6632 6633 :term:`SDK_INCLUDE_TOOLCHAIN` 6634 When set to "1", specifies to include the toolchain in the extensible 6635 SDK. Including the toolchain is useful particularly when 6636 :term:`SDK_EXT_TYPE` is set to "minimal" to keep 6637 the SDK reasonably small but you still want to provide a usable 6638 toolchain. For example, suppose you want to use the toolchain from an 6639 IDE or from other tools and you do not want to perform additional 6640 steps to install the toolchain. 6641 6642 The :term:`SDK_INCLUDE_TOOLCHAIN` variable defaults to "0" if 6643 :term:`SDK_EXT_TYPE` is set to "minimal", and defaults to "1" if 6644 :term:`SDK_EXT_TYPE` is set to "full". 6645 6646 :term:`SDK_NAME` 6647 The base name for SDK output files. The name is derived from the 6648 :term:`DISTRO`, :term:`TCLIBC`, 6649 :term:`SDK_ARCH`, 6650 :term:`IMAGE_BASENAME`, and 6651 :term:`TUNE_PKGARCH` variables:: 6652 6653 SDK_NAME = "${DISTRO}-${TCLIBC}-${SDK_ARCH}-${IMAGE_BASENAME}-${TUNE_PKGARCH}" 6654 6655 :term:`SDK_OS` 6656 Specifies the operating system for which the SDK will be built. The 6657 default value is the value of :term:`BUILD_OS`. 6658 6659 :term:`SDK_OUTPUT` 6660 The location used by the OpenEmbedded build system when creating SDK 6661 output. The :ref:`populate_sdk_base <ref-classes-populate-sdk-*>` 6662 class defines the variable as follows:: 6663 6664 SDK_DIR = "${WORKDIR}/sdk" 6665 SDK_OUTPUT = "${SDK_DIR}/image" 6666 SDK_DEPLOY = "${DEPLOY_DIR}/sdk" 6667 6668 .. note:: 6669 6670 The :term:`SDK_OUTPUT` directory is a temporary directory as it is part of 6671 :term:`WORKDIR` by way of :term:`SDK_DIR`. The final output directory is 6672 :term:`SDK_DEPLOY`. 6673 6674 :term:`SDK_PACKAGE_ARCHS` 6675 Specifies a list of architectures compatible with the SDK machine. 6676 This variable is set automatically and should not normally be 6677 hand-edited. Entries are separated using spaces and listed in order 6678 of priority. The default value for :term:`SDK_PACKAGE_ARCHS` is "all any 6679 noarch ${SDK_ARCH}-${SDKPKGSUFFIX}". 6680 6681 :term:`SDK_POSTPROCESS_COMMAND` 6682 Specifies a list of functions to call once the OpenEmbedded build 6683 system creates the SDK. You can specify functions separated by 6684 semicolons: SDK_POSTPROCESS_COMMAND += "function; ... " 6685 6686 If you need to pass an SDK path to a command within a function, you 6687 can use ``${SDK_DIR}``, which points to the parent directory used by 6688 the OpenEmbedded build system when creating SDK output. See the 6689 :term:`SDK_DIR` variable for more information. 6690 6691 :term:`SDK_PREFIX` 6692 The toolchain binary prefix used for ``nativesdk`` recipes. The 6693 OpenEmbedded build system uses the :term:`SDK_PREFIX` value to set the 6694 :term:`TARGET_PREFIX` when building 6695 ``nativesdk`` recipes. The default value is "${SDK_SYS}-". 6696 6697 :term:`SDK_RECRDEP_TASKS` 6698 A list of shared state tasks added to the extensible SDK. By default, 6699 the following tasks are added: 6700 6701 - do_populate_lic 6702 - do_package_qa 6703 - do_populate_sysroot 6704 - do_deploy 6705 6706 Despite the default value of "" for the 6707 :term:`SDK_RECRDEP_TASKS` variable, the above four tasks are always added 6708 to the SDK. To specify tasks beyond these four, you need to use the 6709 :term:`SDK_RECRDEP_TASKS` variable (e.g. you are defining additional 6710 tasks that are needed in order to build 6711 :term:`SDK_TARGETS`). 6712 6713 :term:`SDK_SYS` 6714 Specifies the system, including the architecture and the operating 6715 system, for which the SDK will be built. 6716 6717 The OpenEmbedded build system automatically sets this variable based 6718 on :term:`SDK_ARCH`, 6719 :term:`SDK_VENDOR`, and 6720 :term:`SDK_OS`. You do not need to set the :term:`SDK_SYS` 6721 variable yourself. 6722 6723 :term:`SDK_TARGET_MANIFEST` 6724 The manifest file for the target part of the SDK. This file lists all 6725 the installed packages that make up the target part of the SDK. The 6726 file contains package information on a line-per-package basis as 6727 follows:: 6728 6729 packagename packagearch version 6730 6731 The :ref:`populate_sdk_base <ref-classes-populate-sdk-*>` class 6732 defines the manifest file as follows:: 6733 6734 SDK_TARGET_MANIFEST = "${SDK_DEPLOY}/${TOOLCHAIN_OUTPUTNAME}.target.manifest" 6735 6736 The location is derived using the :term:`SDK_DEPLOY` and 6737 :term:`TOOLCHAIN_OUTPUTNAME` variables. 6738 6739 :term:`SDK_TARGETS` 6740 A list of targets to install from shared state as part of the 6741 standard or extensible SDK installation. The default value is "${PN}" 6742 (i.e. the image from which the SDK is built). 6743 6744 The :term:`SDK_TARGETS` variable is an internal variable and typically 6745 would not be changed. 6746 6747 :term:`SDK_TITLE` 6748 The title to be printed when running the SDK installer. By default, 6749 this title is based on the :term:`DISTRO_NAME` or 6750 :term:`DISTRO` variable and is set in the 6751 :ref:`populate_sdk_base <ref-classes-populate-sdk-*>` class as 6752 follows:: 6753 6754 SDK_TITLE ??= "${@d.getVar('DISTRO_NAME') or d.getVar('DISTRO')} SDK" 6755 6756 For the default distribution "poky", 6757 :term:`SDK_TITLE` is set to "Poky (Yocto Project Reference Distro)". 6758 6759 For information on how to change this default title, see the 6760 ":ref:`sdk-manual/appendix-customizing:changing the extensible sdk installer title`" 6761 section in the Yocto Project Application Development and the 6762 Extensible Software Development Kit (eSDK) manual. 6763 6764 :term:`SDK_UPDATE_URL` 6765 An optional URL for an update server for the extensible SDK. If set, 6766 the value is used as the default update server when running 6767 ``devtool sdk-update`` within the extensible SDK. 6768 6769 :term:`SDK_VENDOR` 6770 Specifies the name of the SDK vendor. 6771 6772 :term:`SDK_VERSION` 6773 Specifies the version of the SDK. The Poky distribution configuration file 6774 (``/meta-poky/conf/distro/poky.conf``) sets the default 6775 :term:`SDK_VERSION` as follows:: 6776 6777 SDK_VERSION = "${@d.getVar('DISTRO_VERSION').replace('snapshot-${METADATA_REVISION}', 'snapshot')}" 6778 6779 For additional information, see the 6780 :term:`DISTRO_VERSION` and 6781 :term:`METADATA_REVISION` variables. 6782 6783 :term:`SDKEXTPATH` 6784 The default installation directory for the Extensible SDK. By 6785 default, this directory is based on the :term:`DISTRO` 6786 variable and is set in the 6787 :ref:`populate_sdk_base <ref-classes-populate-sdk-*>` class as 6788 follows:: 6789 6790 SDKEXTPATH ??= "~/${@d.getVar('DISTRO')}_sdk" 6791 6792 For the 6793 default distribution "poky", the :term:`SDKEXTPATH` is set to "poky_sdk". 6794 6795 For information on how to change this default directory, see the 6796 ":ref:`sdk-manual/appendix-customizing:changing the default sdk installation directory`" 6797 section in the Yocto Project Application Development and the 6798 Extensible Software Development Kit (eSDK) manual. 6799 6800 :term:`SDKIMAGE_FEATURES` 6801 Equivalent to :term:`IMAGE_FEATURES`. However, this variable applies to 6802 the SDK generated from an image using the following command:: 6803 6804 $ bitbake -c populate_sdk imagename 6805 6806 :term:`SDKMACHINE` 6807 The machine for which the SDK is built. In other words, the SDK is built 6808 such that it runs on the target you specify with the :term:`SDKMACHINE` 6809 value. The value points to a corresponding ``.conf`` file under 6810 ``conf/machine-sdk/`` in the enabled layers, for example ``aarch64``, 6811 ``i586``, ``i686``, ``ppc64``, ``ppc64le``, and ``x86_64`` are 6812 :oe_git:`available in OpenEmbedded-Core </openembedded-core/tree/meta/conf/machine-sdk>`. 6813 6814 The variable defaults to :term:`BUILD_ARCH` so that SDKs are built for the 6815 architecture of the build machine. 6816 6817 .. note:: 6818 6819 You cannot set the :term:`SDKMACHINE` 6820 variable in your distribution configuration file. If you do, the 6821 configuration will not take effect. 6822 6823 :term:`SDKPATH` 6824 Defines the path offered to the user for installation of the SDK that 6825 is generated by the OpenEmbedded build system. The path appears as 6826 the default location for installing the SDK when you run the SDK's 6827 installation script. You can override the offered path when you run 6828 the script. 6829 6830 :term:`SDKTARGETSYSROOT` 6831 The full path to the sysroot used for cross-compilation within an SDK 6832 as it will be when installed into the default 6833 :term:`SDKPATH`. 6834 6835 :term:`SECTION` 6836 The section in which packages should be categorized. Package 6837 management utilities can make use of this variable. 6838 6839 :term:`SELECTED_OPTIMIZATION` 6840 Specifies the optimization flags passed to the C compiler when 6841 building for the target. The flags are passed through the default 6842 value of the :term:`TARGET_CFLAGS` variable. 6843 6844 The :term:`SELECTED_OPTIMIZATION` variable takes the value of 6845 :term:`FULL_OPTIMIZATION` unless :term:`DEBUG_BUILD` = "1", in which 6846 case the value of :term:`DEBUG_OPTIMIZATION` is used. 6847 6848 :term:`SERIAL_CONSOLE` 6849 Defines a serial console (TTY) to enable using 6850 `getty <https://en.wikipedia.org/wiki/Getty_(Unix)>`__. Provide a 6851 value that specifies the baud rate followed by the TTY device name 6852 separated by a space. You cannot specify more than one TTY device:: 6853 6854 SERIAL_CONSOLE = "115200 ttyS0" 6855 6856 .. note:: 6857 6858 The :term:`SERIAL_CONSOLE` variable is deprecated. Please use the 6859 :term:`SERIAL_CONSOLES` variable. 6860 6861 :term:`SERIAL_CONSOLES` 6862 Defines a serial console (TTY) to enable using 6863 `getty <https://en.wikipedia.org/wiki/Getty_(Unix)>`__. Provide a 6864 value that specifies the baud rate followed by the TTY device name 6865 separated by a semicolon. Use spaces to separate multiple devices:: 6866 6867 SERIAL_CONSOLES = "115200;ttyS0 115200;ttyS1" 6868 6869 :term:`SERIAL_CONSOLES_CHECK` 6870 Specifies serial consoles, which must be listed in 6871 :term:`SERIAL_CONSOLES`, to check against 6872 ``/proc/console`` before enabling them using getty. This variable 6873 allows aliasing in the format: <device>:<alias>. If a device was 6874 listed as "sclp_line0" in ``/dev/`` and "ttyS0" was listed in 6875 ``/proc/console``, you would do the following:: 6876 6877 SERIAL_CONSOLES_CHECK = "slcp_line0:ttyS0" 6878 6879 This variable is currently only supported with SysVinit (i.e. not 6880 with systemd). Note that :term:`SERIAL_CONSOLES_CHECK` also requires 6881 ``/etc/inittab`` to be writable when used with SysVinit. This makes it 6882 incompatible with customizations such as the following:: 6883 6884 EXTRA_IMAGE_FEATURES += "read-only-rootfs" 6885 6886 :term:`SETUPTOOLS_BUILD_ARGS` 6887 When used by recipes that inherit the 6888 :ref:`setuptools3 <ref-classes-setuptools3>` class, this variable can 6889 be used to specify additional arguments to be passed to ``setup.py build`` 6890 in the ``setuptools3_do_compile()`` task. 6891 6892 :term:`SETUPTOOLS_INSTALL_ARGS` 6893 When used by recipes that inherit the 6894 :ref:`setuptools3 <ref-classes-setuptools3>` class, this variable can 6895 be used to specify additional arguments to be passed to ``setup.py install`` 6896 in the ``setuptools3_do_install()`` task. 6897 6898 :term:`SETUPTOOLS_SETUP_PATH` 6899 When used by recipes that inherit the 6900 :ref:`setuptools3 <ref-classes-setuptools3>` class, this variable should 6901 be used to specify the directory in which the ``setup.py`` file is 6902 located if it is not at the root of the source tree (as specified by 6903 :term:`S`). For example, in a recipe where the sources are fetched from 6904 a Git repository and ``setup.py`` is in a ``python/pythonmodule`` 6905 subdirectory, you would have this:: 6906 6907 S = "${WORKDIR}/git" 6908 SETUPTOOLS_SETUP_PATH = "${S}/python/pythonmodule" 6909 6910 :term:`SIGGEN_EXCLUDE_SAFE_RECIPE_DEPS` 6911 A list of recipe dependencies that should not be used to determine 6912 signatures of tasks from one recipe when they depend on tasks from 6913 another recipe. For example:: 6914 6915 SIGGEN_EXCLUDE_SAFE_RECIPE_DEPS += "intone->mplayer2" 6916 6917 In the previous example, ``intone`` depends on ``mplayer2``. 6918 6919 You can use the special token ``"*"`` on the left-hand side of the 6920 dependency to match all recipes except the one on the right-hand 6921 side. Here is an example:: 6922 6923 SIGGEN_EXCLUDE_SAFE_RECIPE_DEPS += "*->quilt-native" 6924 6925 In the previous example, all recipes except ``quilt-native`` ignore 6926 task signatures from the ``quilt-native`` recipe when determining 6927 their task signatures. 6928 6929 Use of this variable is one mechanism to remove dependencies that 6930 affect task signatures and thus force rebuilds when a recipe changes. 6931 6932 .. note:: 6933 6934 If you add an inappropriate dependency for a recipe relationship, 6935 the software might break during runtime if the interface of the 6936 second recipe was changed after the first recipe had been built. 6937 6938 :term:`SIGGEN_EXCLUDERECIPES_ABISAFE` 6939 A list of recipes that are completely stable and will never change. 6940 The ABI for the recipes in the list are presented by output from the 6941 tasks run to build the recipe. Use of this variable is one way to 6942 remove dependencies from one recipe on another that affect task 6943 signatures and thus force rebuilds when the recipe changes. 6944 6945 .. note:: 6946 6947 If you add an inappropriate variable to this list, the software 6948 might break at runtime if the interface of the recipe was changed 6949 after the other had been built. 6950 6951 :term:`SITEINFO_BITS` 6952 Specifies the number of bits for the target system CPU. The value 6953 should be either "32" or "64". 6954 6955 :term:`SITEINFO_ENDIANNESS` 6956 Specifies the endian byte order of the target system. The value 6957 should be either "le" for little-endian or "be" for big-endian. 6958 6959 :term:`SKIP_FILEDEPS` 6960 Enables removal of all files from the "Provides" section of an RPM 6961 package. Removal of these files is required for packages containing 6962 prebuilt binaries and libraries such as ``libstdc++`` and ``glibc``. 6963 6964 To enable file removal, set the variable to "1" in your 6965 ``conf/local.conf`` configuration file in your: 6966 :term:`Build Directory`. 6967 :: 6968 6969 SKIP_FILEDEPS = "1" 6970 6971 :term:`SKIP_RECIPE` 6972 Used to prevent the OpenEmbedded build system from building a given 6973 recipe. Specify the :term:`PN` value as a variable flag (``varflag``) 6974 and provide a reason, which will be reported when attempting to 6975 build the recipe. 6976 6977 To prevent a recipe from being built, use the :term:`SKIP_RECIPE` 6978 variable in your ``local.conf`` file or distribution configuration. 6979 Here is an example which prevents ``myrecipe`` from being built:: 6980 6981 SKIP_RECIPE[myrecipe] = "Not supported by our organization." 6982 6983 :term:`SOC_FAMILY` 6984 Groups together machines based upon the same family of SOC (System On 6985 Chip). You typically set this variable in a common ``.inc`` file that 6986 you include in the configuration files of all the machines. 6987 6988 .. note:: 6989 6990 You must include ``conf/machine/include/soc-family.inc`` for this 6991 variable to appear in :term:`MACHINEOVERRIDES`. 6992 6993 :term:`SOLIBS` 6994 Defines the suffix for shared libraries used on the target platform. 6995 By default, this suffix is ".so.*" for all Linux-based systems and is 6996 defined in the ``meta/conf/bitbake.conf`` configuration file. 6997 6998 You will see this variable referenced in the default values of 6999 ``FILES:${PN}``. 7000 7001 :term:`SOLIBSDEV` 7002 Defines the suffix for the development symbolic link (symlink) for 7003 shared libraries on the target platform. By default, this suffix is 7004 ".so" for Linux-based systems and is defined in the 7005 ``meta/conf/bitbake.conf`` configuration file. 7006 7007 You will see this variable referenced in the default values of 7008 ``FILES:${PN}-dev``. 7009 7010 :term:`SOURCE_DATE_EPOCH` 7011 This defines a date expressed in number of seconds since 7012 the UNIX EPOCH (01 Jan 1970 00:00:00 UTC), which is used by 7013 multiple build systems to force a timestamp in built binaries. 7014 Many upstream projects already support this variable. 7015 7016 You will find more details in the `official specifications 7017 <https://reproducible-builds.org/specs/source-date-epoch/>`__. 7018 7019 A value for each recipe is computed from the sources by 7020 :oe_git:`meta/lib/oe/reproducible.py </openembedded-core/tree/meta/lib/oe/reproducible.py>`. 7021 7022 If a recipe wishes to override the default behavior, it should set its 7023 own :term:`SOURCE_DATE_EPOCH` value:: 7024 7025 SOURCE_DATE_EPOCH = "1613559011" 7026 7027 :term:`SOURCE_MIRROR_FETCH` 7028 When you are fetching files to create a mirror of sources (i.e. 7029 creating a source mirror), setting :term:`SOURCE_MIRROR_FETCH` to "1" in 7030 your ``local.conf`` configuration file ensures the source for all 7031 recipes are fetched regardless of whether or not a recipe is 7032 compatible with the configuration. A recipe is considered 7033 incompatible with the currently configured machine when either or 7034 both the :term:`COMPATIBLE_MACHINE` 7035 variable and :term:`COMPATIBLE_HOST` variables 7036 specify compatibility with a machine other than that of the current 7037 machine or host. 7038 7039 .. note:: 7040 7041 Do not set the :term:`SOURCE_MIRROR_FETCH` 7042 variable unless you are creating a source mirror. In other words, 7043 do not set the variable during a normal build. 7044 7045 :term:`SOURCE_MIRROR_URL` 7046 Defines your own :term:`PREMIRRORS` from which to 7047 first fetch source before attempting to fetch from the upstream 7048 specified in :term:`SRC_URI`. 7049 7050 To use this variable, you must globally inherit the 7051 :ref:`own-mirrors <ref-classes-own-mirrors>` class and then provide 7052 the URL to your mirrors. Here is the general syntax:: 7053 7054 INHERIT += "own-mirrors" 7055 SOURCE_MIRROR_URL = "http://example.com/my_source_mirror" 7056 7057 .. note:: 7058 7059 You can specify only a single URL in :term:`SOURCE_MIRROR_URL`. 7060 7061 :term:`SPDXLICENSEMAP` 7062 Maps commonly used license names to their SPDX counterparts found in 7063 ``meta/files/common-licenses/``. For the default :term:`SPDXLICENSEMAP` 7064 mappings, see the ``meta/conf/licenses.conf`` file. 7065 7066 For additional information, see the :term:`LICENSE` 7067 variable. 7068 7069 :term:`SPECIAL_PKGSUFFIX` 7070 A list of prefixes for :term:`PN` used by the OpenEmbedded 7071 build system to create variants of recipes or packages. The list 7072 specifies the prefixes to strip off during certain circumstances such 7073 as the generation of the :term:`BPN` variable. 7074 7075 :term:`SPL_BINARY` 7076 The file type for the Secondary Program Loader (SPL). Some devices 7077 use an SPL from which to boot (e.g. the BeagleBone development 7078 board). For such cases, you can declare the file type of the SPL 7079 binary in the ``u-boot.inc`` include file, which is used in the 7080 U-Boot recipe. 7081 7082 The SPL file type is set to "null" by default in the ``u-boot.inc`` 7083 file as follows:: 7084 7085 # Some versions of u-boot build an SPL (Second Program Loader) image that 7086 # should be packaged along with the u-boot binary as well as placed in the 7087 # deploy directory. For those versions they can set the following variables 7088 # to allow packaging the SPL. 7089 SPL_BINARY ?= "" 7090 SPL_BINARYNAME ?= "${@os.path.basename(d.getVar("SPL_BINARY"))}" 7091 SPL_IMAGE ?= "${SPL_BINARYNAME}-${MACHINE}-${PV}-${PR}" 7092 SPL_SYMLINK ?= "${SPL_BINARYNAME}-${MACHINE}" 7093 7094 The :term:`SPL_BINARY` variable helps form 7095 various ``SPL_*`` variables used by the OpenEmbedded build system. 7096 7097 See the BeagleBone machine configuration example in the 7098 ":ref:`dev-manual/common-tasks:adding a layer using the \`\`bitbake-layers\`\` script`" 7099 section in the Yocto Project Board Support Package Developer's Guide 7100 for additional information. 7101 7102 :term:`SRC_URI` 7103 7104 See the BitBake manual for the initial description for this variable: 7105 :term:`bitbake:SRC_URI`. 7106 7107 The following features are added by OpenEmbedded and the Yocto Project. 7108 7109 There are standard and recipe-specific options. Here are standard ones: 7110 7111 - ``apply`` - Whether to apply the patch or not. The default 7112 action is to apply the patch. 7113 7114 - ``striplevel`` - Which striplevel to use when applying the 7115 patch. The default level is 1. 7116 7117 - ``patchdir`` - Specifies the directory in which the patch should 7118 be applied. The default is ``${``\ :term:`S`\ ``}``. 7119 7120 Here are options specific to recipes building code from a revision 7121 control system: 7122 7123 - ``mindate`` - Apply the patch only if 7124 :term:`SRCDATE` is equal to or greater than 7125 ``mindate``. 7126 7127 - ``maxdate`` - Apply the patch only if :term:`SRCDATE` is not later 7128 than ``maxdate``. 7129 7130 - ``minrev`` - Apply the patch only if :term:`SRCREV` is equal to or 7131 greater than ``minrev``. 7132 7133 - ``maxrev`` - Apply the patch only if :term:`SRCREV` is not later 7134 than ``maxrev``. 7135 7136 - ``rev`` - Apply the patch only if :term:`SRCREV` is equal to 7137 ``rev``. 7138 7139 - ``notrev`` - Apply the patch only if :term:`SRCREV` is not equal to 7140 ``rev``. 7141 7142 .. note:: 7143 7144 If you want the build system to pick up files specified through 7145 a :term:`SRC_URI` statement from your append file, you need to be 7146 sure to extend the :term:`FILESPATH` variable by also using the 7147 :term:`FILESEXTRAPATHS` variable from within your append file. 7148 7149 :term:`SRC_URI_OVERRIDES_PACKAGE_ARCH` 7150 By default, the OpenEmbedded build system automatically detects 7151 whether :term:`SRC_URI` contains files that are machine-specific. If so, 7152 the build system automatically changes :term:`PACKAGE_ARCH`. Setting this 7153 variable to "0" disables this behavior. 7154 7155 :term:`SRCDATE` 7156 The date of the source code used to build the package. This variable 7157 applies only if the source was fetched from a Source Code Manager 7158 (SCM). 7159 7160 :term:`SRCPV` 7161 Returns the version string of the current package. This string is 7162 used to help define the value of :term:`PV`. 7163 7164 The :term:`SRCPV` variable is defined in the ``meta/conf/bitbake.conf`` 7165 configuration file in the :term:`Source Directory` as 7166 follows:: 7167 7168 SRCPV = "${@bb.fetch2.get_srcrev(d)}" 7169 7170 Recipes that need to define :term:`PV` do so with the help of the 7171 :term:`SRCPV`. For example, the ``ofono`` recipe (``ofono_git.bb``) 7172 located in ``meta/recipes-connectivity`` in the Source Directory 7173 defines :term:`PV` as follows:: 7174 7175 PV = "0.12-git${SRCPV}" 7176 7177 :term:`SRCREV` 7178 The revision of the source code used to build the package. This 7179 variable applies to Subversion, Git, Mercurial, and Bazaar only. Note 7180 that if you want to build a fixed revision and you want to avoid 7181 performing a query on the remote repository every time BitBake parses 7182 your recipe, you should specify a :term:`SRCREV` that is a full revision 7183 identifier and not just a tag. 7184 7185 .. note:: 7186 7187 For information on limitations when inheriting the latest revision 7188 of software using :term:`SRCREV`, see the :term:`AUTOREV` variable 7189 description and the 7190 ":ref:`dev-manual/common-tasks:automatically incrementing a package version number`" 7191 section, which is in the Yocto Project Development Tasks Manual. 7192 7193 :term:`SRCTREECOVEREDTASKS` 7194 A list of tasks that are typically not relevant (and therefore skipped) 7195 when building using the :ref:`externalsrc <ref-classes-externalsrc>` 7196 class. The default value as set in that class file is the set of tasks 7197 that are rarely needed when using external source:: 7198 7199 SRCTREECOVEREDTASKS ?= "do_patch do_unpack do_fetch" 7200 7201 The notable exception is when processing external kernel source as 7202 defined in the :ref:`kernel-yocto <ref-classes-kernel-yocto>` 7203 class file (formatted for aesthetics):: 7204 7205 SRCTREECOVEREDTASKS += "\ 7206 do_validate_branches \ 7207 do_kernel_configcheck \ 7208 do_kernel_checkout \ 7209 do_fetch \ 7210 do_unpack \ 7211 do_patch \ 7212 " 7213 7214 See the associated :term:`EXTERNALSRC` and :term:`EXTERNALSRC_BUILD` 7215 variables for more information. 7216 7217 :term:`SSTATE_DIR` 7218 The directory for the shared state cache. 7219 7220 :term:`SSTATE_MIRROR_ALLOW_NETWORK` 7221 If set to "1", allows fetches from mirrors that are specified in 7222 :term:`SSTATE_MIRRORS` to work even when 7223 fetching from the network is disabled by setting :term:`BB_NO_NETWORK` to 7224 "1". Using the :term:`SSTATE_MIRROR_ALLOW_NETWORK` variable is useful if 7225 you have set :term:`SSTATE_MIRRORS` to point to an internal server for 7226 your shared state cache, but you want to disable any other fetching 7227 from the network. 7228 7229 :term:`SSTATE_MIRRORS` 7230 Configures the OpenEmbedded build system to search other mirror 7231 locations for prebuilt cache data objects before building out the 7232 data. This variable works like fetcher :term:`MIRRORS` 7233 and :term:`PREMIRRORS` and points to the cache 7234 locations to check for the shared state (sstate) objects. 7235 7236 You can specify a filesystem directory or a remote URL such as HTTP 7237 or FTP. The locations you specify need to contain the shared state 7238 cache (sstate-cache) results from previous builds. The sstate-cache 7239 you point to can also be from builds on other machines. 7240 7241 When pointing to sstate build artifacts on another machine that uses 7242 a different GCC version for native builds, you must configure 7243 :term:`SSTATE_MIRRORS` with a regular expression that maps local search 7244 paths to server paths. The paths need to take into account 7245 :term:`NATIVELSBSTRING` set by the 7246 :ref:`uninative <ref-classes-uninative>` class. For example, the 7247 following maps the local search path ``universal-4.9`` to the 7248 server-provided path server_url_sstate_path:: 7249 7250 SSTATE_MIRRORS ?= "file://universal-4.9/(.*) https://server_url_sstate_path/universal-4.8/\1" 7251 7252 If a mirror uses the same structure as 7253 :term:`SSTATE_DIR`, you need to add "PATH" at the 7254 end as shown in the examples below. The build system substitutes the 7255 correct path within the directory structure. 7256 :: 7257 7258 SSTATE_MIRRORS ?= "\ 7259 file://.* https://someserver.tld/share/sstate/PATH;downloadfilename=PATH \ 7260 file://.* file:///some-local-dir/sstate/PATH" 7261 7262 :term:`SSTATE_SCAN_FILES` 7263 Controls the list of files the OpenEmbedded build system scans for 7264 hardcoded installation paths. The variable uses a space-separated 7265 list of filenames (not paths) with standard wildcard characters 7266 allowed. 7267 7268 During a build, the OpenEmbedded build system creates a shared state 7269 (sstate) object during the first stage of preparing the sysroots. 7270 That object is scanned for hardcoded paths for original installation 7271 locations. The list of files that are scanned for paths is controlled 7272 by the :term:`SSTATE_SCAN_FILES` variable. Typically, recipes add files 7273 they want to be scanned to the value of :term:`SSTATE_SCAN_FILES` rather 7274 than the variable being comprehensively set. The 7275 :ref:`sstate <ref-classes-sstate>` class specifies the default list 7276 of files. 7277 7278 For details on the process, see the 7279 :ref:`staging <ref-classes-staging>` class. 7280 7281 :term:`STAGING_BASE_LIBDIR_NATIVE` 7282 Specifies the path to the ``/lib`` subdirectory of the sysroot 7283 directory for the build host. 7284 7285 :term:`STAGING_BASELIBDIR` 7286 Specifies the path to the ``/lib`` subdirectory of the sysroot 7287 directory for the target for which the current recipe is being built 7288 (:term:`STAGING_DIR_HOST`). 7289 7290 :term:`STAGING_BINDIR` 7291 Specifies the path to the ``/usr/bin`` subdirectory of the sysroot 7292 directory for the target for which the current recipe is being built 7293 (:term:`STAGING_DIR_HOST`). 7294 7295 :term:`STAGING_BINDIR_CROSS` 7296 Specifies the path to the directory containing binary configuration 7297 scripts. These scripts provide configuration information for other 7298 software that wants to make use of libraries or include files 7299 provided by the software associated with the script. 7300 7301 .. note:: 7302 7303 This style of build configuration has been largely replaced by 7304 ``pkg-config``. Consequently, if ``pkg-config`` is supported by the 7305 library to which you are linking, it is recommended you use 7306 ``pkg-config`` instead of a provided configuration script. 7307 7308 :term:`STAGING_BINDIR_NATIVE` 7309 Specifies the path to the ``/usr/bin`` subdirectory of the sysroot 7310 directory for the build host. 7311 7312 :term:`STAGING_DATADIR` 7313 Specifies the path to the ``/usr/share`` subdirectory of the sysroot 7314 directory for the target for which the current recipe is being built 7315 (:term:`STAGING_DIR_HOST`). 7316 7317 :term:`STAGING_DATADIR_NATIVE` 7318 Specifies the path to the ``/usr/share`` subdirectory of the sysroot 7319 directory for the build host. 7320 7321 :term:`STAGING_DIR` 7322 Helps construct the ``recipe-sysroots`` directory, which is used 7323 during packaging. 7324 7325 For information on how staging for recipe-specific sysroots occurs, 7326 see the :ref:`ref-tasks-populate_sysroot` 7327 task, the ":ref:`sdk-manual/extensible:sharing files between recipes`" 7328 section in the Yocto Project Development Tasks Manual, the 7329 ":ref:`overview-manual/concepts:configuration, compilation, and staging`" 7330 section in the Yocto Project Overview and Concepts Manual, and the 7331 :term:`SYSROOT_DIRS` variable. 7332 7333 .. note:: 7334 7335 Recipes should never write files directly under the :term:`STAGING_DIR` 7336 directory because the OpenEmbedded build system manages the 7337 directory automatically. Instead, files should be installed to 7338 ``${``\ :term:`D`\ ``}`` within your recipe's :ref:`ref-tasks-install` 7339 task and then the OpenEmbedded build system will stage a subset of 7340 those files into the sysroot. 7341 7342 :term:`STAGING_DIR_HOST` 7343 Specifies the path to the sysroot directory for the system on which 7344 the component is built to run (the system that hosts the component). 7345 For most recipes, this sysroot is the one in which that recipe's 7346 :ref:`ref-tasks-populate_sysroot` task copies 7347 files. Exceptions include ``-native`` recipes, where the 7348 ``do_populate_sysroot`` task instead uses 7349 :term:`STAGING_DIR_NATIVE`. Depending on 7350 the type of recipe and the build target, :term:`STAGING_DIR_HOST` can 7351 have the following values: 7352 7353 - For recipes building for the target machine, the value is 7354 "${:term:`STAGING_DIR`}/${:term:`MACHINE`}". 7355 7356 - For native recipes building for the build host, the value is empty 7357 given the assumption that when building for the build host, the 7358 build host's own directories should be used. 7359 7360 .. note:: 7361 7362 ``-native`` recipes are not installed into host paths like such 7363 as ``/usr``. Rather, these recipes are installed into 7364 :term:`STAGING_DIR_NATIVE`. When compiling ``-native`` recipes, 7365 standard build environment variables such as 7366 :term:`CPPFLAGS` and 7367 :term:`CFLAGS` are set up so that both host paths 7368 and :term:`STAGING_DIR_NATIVE` are searched for libraries and 7369 headers using, for example, GCC's ``-isystem`` option. 7370 7371 Thus, the emphasis is that the ``STAGING_DIR*`` variables 7372 should be viewed as input variables by tasks such as 7373 :ref:`ref-tasks-configure`, 7374 :ref:`ref-tasks-compile`, and 7375 :ref:`ref-tasks-install`. Having the real system 7376 root correspond to :term:`STAGING_DIR_HOST` makes conceptual sense 7377 for ``-native`` recipes, as they make use of host headers and 7378 libraries. 7379 7380 :term:`STAGING_DIR_NATIVE` 7381 Specifies the path to the sysroot directory used when building 7382 components that run on the build host itself. 7383 7384 :term:`STAGING_DIR_TARGET` 7385 Specifies the path to the sysroot used for the system for which the 7386 component generates code. For components that do not generate code, 7387 which is the majority, :term:`STAGING_DIR_TARGET` is set to match 7388 :term:`STAGING_DIR_HOST`. 7389 7390 Some recipes build binaries that can run on the target system but 7391 those binaries in turn generate code for another different system 7392 (e.g. cross-canadian recipes). Using terminology from GNU, the 7393 primary system is referred to as the "HOST" and the secondary, or 7394 different, system is referred to as the "TARGET". Thus, the binaries 7395 run on the "HOST" system and generate binaries for the "TARGET" 7396 system. The :term:`STAGING_DIR_HOST` variable points to the sysroot used 7397 for the "HOST" system, while :term:`STAGING_DIR_TARGET` points to the 7398 sysroot used for the "TARGET" system. 7399 7400 :term:`STAGING_ETCDIR_NATIVE` 7401 Specifies the path to the ``/etc`` subdirectory of the sysroot 7402 directory for the build host. 7403 7404 :term:`STAGING_EXECPREFIXDIR` 7405 Specifies the path to the ``/usr`` subdirectory of the sysroot 7406 directory for the target for which the current recipe is being built 7407 (:term:`STAGING_DIR_HOST`). 7408 7409 :term:`STAGING_INCDIR` 7410 Specifies the path to the ``/usr/include`` subdirectory of the 7411 sysroot directory for the target for which the current recipe being 7412 built (:term:`STAGING_DIR_HOST`). 7413 7414 :term:`STAGING_INCDIR_NATIVE` 7415 Specifies the path to the ``/usr/include`` subdirectory of the 7416 sysroot directory for the build host. 7417 7418 :term:`STAGING_KERNEL_BUILDDIR` 7419 Points to the directory containing the kernel build artifacts. 7420 Recipes building software that needs to access kernel build artifacts 7421 (e.g. ``systemtap-uprobes``) can look in the directory specified with 7422 the :term:`STAGING_KERNEL_BUILDDIR` variable to find these artifacts 7423 after the kernel has been built. 7424 7425 :term:`STAGING_KERNEL_DIR` 7426 The directory with kernel headers that are required to build 7427 out-of-tree modules. 7428 7429 :term:`STAGING_LIBDIR` 7430 Specifies the path to the ``/usr/lib`` subdirectory of the sysroot 7431 directory for the target for which the current recipe is being built 7432 (:term:`STAGING_DIR_HOST`). 7433 7434 :term:`STAGING_LIBDIR_NATIVE` 7435 Specifies the path to the ``/usr/lib`` subdirectory of the sysroot 7436 directory for the build host. 7437 7438 :term:`STAMP` 7439 Specifies the base path used to create recipe stamp files. The path 7440 to an actual stamp file is constructed by evaluating this string and 7441 then appending additional information. Currently, the default 7442 assignment for :term:`STAMP` as set in the ``meta/conf/bitbake.conf`` 7443 file is:: 7444 7445 STAMP = "${STAMPS_DIR}/${MULTIMACH_TARGET_SYS}/${PN}/${EXTENDPE}${PV}-${PR}" 7446 7447 For information on how BitBake uses stamp files to determine if a 7448 task should be rerun, see the 7449 ":ref:`overview-manual/concepts:stamp files and the rerunning of tasks`" 7450 section in the Yocto Project Overview and Concepts Manual. 7451 7452 See :term:`STAMPS_DIR`, 7453 :term:`MULTIMACH_TARGET_SYS`, 7454 :term:`PN`, :term:`EXTENDPE`, 7455 :term:`PV`, and :term:`PR` for related variable 7456 information. 7457 7458 :term:`STAMPS_DIR` 7459 Specifies the base directory in which the OpenEmbedded build system 7460 places stamps. The default directory is ``${TMPDIR}/stamps``. 7461 7462 :term:`STRIP` 7463 The minimal command and arguments to run ``strip``, which is used to 7464 strip symbols. 7465 7466 :term:`SUMMARY` 7467 The short (72 characters or less) summary of the binary package for 7468 packaging systems such as ``opkg``, ``rpm``, or ``dpkg``. By default, 7469 :term:`SUMMARY` is used to define the 7470 :term:`DESCRIPTION` variable if :term:`DESCRIPTION` is 7471 not set in the recipe. 7472 7473 :term:`SVNDIR` 7474 The directory in which files checked out of a Subversion system are 7475 stored. 7476 7477 :term:`SYSLINUX_DEFAULT_CONSOLE` 7478 Specifies the kernel boot default console. If you want to use a 7479 console other than the default, set this variable in your recipe as 7480 follows where "X" is the console number you want to use:: 7481 7482 SYSLINUX_DEFAULT_CONSOLE = "console=ttyX" 7483 7484 The :ref:`syslinux <ref-classes-syslinux>` class initially sets 7485 this variable to null but then checks for a value later. 7486 7487 :term:`SYSLINUX_OPTS` 7488 Lists additional options to add to the syslinux file. You need to set 7489 this variable in your recipe. If you want to list multiple options, 7490 separate the options with a semicolon character (``;``). 7491 7492 The :ref:`syslinux <ref-classes-syslinux>` class uses this variable 7493 to create a set of options. 7494 7495 :term:`SYSLINUX_SERIAL` 7496 Specifies the alternate serial port or turns it off. To turn off 7497 serial, set this variable to an empty string in your recipe. The 7498 variable's default value is set in the 7499 :ref:`syslinux <ref-classes-syslinux>` class as follows:: 7500 7501 SYSLINUX_SERIAL ?= "0 115200" 7502 7503 The class checks for and uses the variable as needed. 7504 7505 :term:`SYSLINUX_SERIAL_TTY` 7506 Specifies the alternate console=tty... kernel boot argument. The 7507 variable's default value is set in the 7508 :ref:`syslinux <ref-classes-syslinux>` class as follows:: 7509 7510 SYSLINUX_SERIAL_TTY ?= "console=ttyS0,115200" 7511 7512 The class checks for and uses the variable as needed. 7513 7514 :term:`SYSLINUX_SPLASH` 7515 An ``.LSS`` file used as the background for the VGA boot menu when 7516 you use the boot menu. You need to set this variable in your recipe. 7517 7518 The :ref:`syslinux <ref-classes-syslinux>` class checks for this 7519 variable and if found, the OpenEmbedded build system installs the 7520 splash screen. 7521 7522 :term:`SYSROOT_DESTDIR` 7523 Points to the temporary directory under the work directory (default 7524 "``${``\ :term:`WORKDIR`\ ``}/sysroot-destdir``") 7525 where the files populated into the sysroot are assembled during the 7526 :ref:`ref-tasks-populate_sysroot` task. 7527 7528 :term:`SYSROOT_DIRS` 7529 Directories that are staged into the sysroot by the 7530 :ref:`ref-tasks-populate_sysroot` task. By 7531 default, the following directories are staged:: 7532 7533 SYSROOT_DIRS = " \ 7534 ${includedir} \ 7535 ${libdir} \ 7536 ${base_libdir} \ 7537 ${nonarch_base_libdir} \ 7538 ${datadir} \ 7539 /sysroot-only \ 7540 " 7541 7542 :term:`SYSROOT_DIRS_IGNORE` 7543 Directories that are not staged into the sysroot by the 7544 :ref:`ref-tasks-populate_sysroot` task. You 7545 can use this variable to exclude certain subdirectories of 7546 directories listed in :term:`SYSROOT_DIRS` from 7547 staging. By default, the following directories are not staged:: 7548 7549 SYSROOT_DIRS_IGNORE = " \ 7550 ${mandir} \ 7551 ${docdir} \ 7552 ${infodir} \ 7553 ${datadir}/X11/locale \ 7554 ${datadir}/applications \ 7555 ${datadir}/bash-completion \ 7556 ${datadir}/fonts \ 7557 ${datadir}/gtk-doc/html \ 7558 ${datadir}/installed-tests \ 7559 ${datadir}/locale \ 7560 ${datadir}/pixmaps \ 7561 ${datadir}/terminfo \ 7562 ${libdir}/${BPN}/ptest \ 7563 " 7564 7565 :term:`SYSROOT_DIRS_NATIVE` 7566 Extra directories staged into the sysroot by the 7567 :ref:`ref-tasks-populate_sysroot` task for 7568 ``-native`` recipes, in addition to those specified in 7569 :term:`SYSROOT_DIRS`. By default, the following 7570 extra directories are staged:: 7571 7572 SYSROOT_DIRS_NATIVE = " \ 7573 ${bindir} \ 7574 ${sbindir} \ 7575 ${base_bindir} \ 7576 ${base_sbindir} \ 7577 ${libexecdir} \ 7578 ${sysconfdir} \ 7579 ${localstatedir} \ 7580 " 7581 7582 .. note:: 7583 7584 Programs built by ``-native`` recipes run directly from the sysroot 7585 (:term:`STAGING_DIR_NATIVE`), which is why additional directories 7586 containing program executables and supporting files need to be staged. 7587 7588 :term:`SYSROOT_PREPROCESS_FUNCS` 7589 A list of functions to execute after files are staged into the 7590 sysroot. These functions are usually used to apply additional 7591 processing on the staged files, or to stage additional files. 7592 7593 :term:`SYSTEMD_AUTO_ENABLE` 7594 When inheriting the :ref:`systemd <ref-classes-systemd>` class, 7595 this variable specifies whether the specified service in 7596 :term:`SYSTEMD_SERVICE` should start 7597 automatically or not. By default, the service is enabled to 7598 automatically start at boot time. The default setting is in the 7599 :ref:`systemd <ref-classes-systemd>` class as follows:: 7600 7601 SYSTEMD_AUTO_ENABLE ??= "enable" 7602 7603 You can disable the service by setting the variable to "disable". 7604 7605 :term:`SYSTEMD_BOOT_CFG` 7606 When :term:`EFI_PROVIDER` is set to 7607 "systemd-boot", the :term:`SYSTEMD_BOOT_CFG` variable specifies the 7608 configuration file that should be used. By default, the 7609 :ref:`systemd-boot <ref-classes-systemd-boot>` class sets the 7610 :term:`SYSTEMD_BOOT_CFG` as follows:: 7611 7612 SYSTEMD_BOOT_CFG ?= "${:term:`S`}/loader.conf" 7613 7614 For information on Systemd-boot, see the `Systemd-boot 7615 documentation <https://www.freedesktop.org/wiki/Software/systemd/systemd-boot/>`__. 7616 7617 :term:`SYSTEMD_BOOT_ENTRIES` 7618 When :term:`EFI_PROVIDER` is set to 7619 "systemd-boot", the :term:`SYSTEMD_BOOT_ENTRIES` variable specifies a 7620 list of entry files (``*.conf``) to install that contain one boot 7621 entry per file. By default, the 7622 :ref:`systemd-boot <ref-classes-systemd-boot>` class sets the 7623 :term:`SYSTEMD_BOOT_ENTRIES` as follows:: 7624 7625 SYSTEMD_BOOT_ENTRIES ?= "" 7626 7627 For information on Systemd-boot, see the `Systemd-boot 7628 documentation <https://www.freedesktop.org/wiki/Software/systemd/systemd-boot/>`__. 7629 7630 :term:`SYSTEMD_BOOT_TIMEOUT` 7631 When :term:`EFI_PROVIDER` is set to 7632 "systemd-boot", the :term:`SYSTEMD_BOOT_TIMEOUT` variable specifies the 7633 boot menu timeout in seconds. By default, the 7634 :ref:`systemd-boot <ref-classes-systemd-boot>` class sets the 7635 :term:`SYSTEMD_BOOT_TIMEOUT` as follows:: 7636 7637 SYSTEMD_BOOT_TIMEOUT ?= "10" 7638 7639 For information on Systemd-boot, see the `Systemd-boot 7640 documentation <https://www.freedesktop.org/wiki/Software/systemd/systemd-boot/>`__. 7641 7642 :term:`SYSTEMD_PACKAGES` 7643 When inheriting the :ref:`systemd <ref-classes-systemd>` class, 7644 this variable locates the systemd unit files when they are not found 7645 in the main recipe's package. By default, the :term:`SYSTEMD_PACKAGES` 7646 variable is set such that the systemd unit files are assumed to 7647 reside in the recipes main package:: 7648 7649 SYSTEMD_PACKAGES ?= "${PN}" 7650 7651 If these unit files are not in this recipe's main package, you need 7652 to use :term:`SYSTEMD_PACKAGES` to list the package or packages in which 7653 the build system can find the systemd unit files. 7654 7655 :term:`SYSTEMD_SERVICE` 7656 When inheriting the :ref:`systemd <ref-classes-systemd>` class, 7657 this variable specifies the systemd service name for a package. 7658 7659 When you specify this file in your recipe, use a package name 7660 override to indicate the package to which the value applies. Here is 7661 an example from the connman recipe:: 7662 7663 SYSTEMD_SERVICE:${PN} = "connman.service" 7664 7665 :term:`SYSVINIT_ENABLED_GETTYS` 7666 When using 7667 :ref:`SysVinit <dev-manual/common-tasks:enabling system services>`, 7668 specifies a space-separated list of the virtual terminals that should 7669 run a `getty <https://en.wikipedia.org/wiki/Getty_%28Unix%29>`__ 7670 (allowing login), assuming :term:`USE_VT` is not set to 7671 "0". 7672 7673 The default value for :term:`SYSVINIT_ENABLED_GETTYS` is "1" (i.e. only 7674 run a getty on the first virtual terminal). 7675 7676 :term:`T` 7677 This variable points to a directory were BitBake places temporary 7678 files, which consist mostly of task logs and scripts, when building a 7679 particular recipe. The variable is typically set as follows:: 7680 7681 T = "${WORKDIR}/temp" 7682 7683 The :term:`WORKDIR` is the directory into which 7684 BitBake unpacks and builds the recipe. The default ``bitbake.conf`` 7685 file sets this variable. 7686 7687 The :term:`T` variable is not to be confused with the 7688 :term:`TMPDIR` variable, which points to the root of 7689 the directory tree where BitBake places the output of an entire 7690 build. 7691 7692 :term:`TARGET_ARCH` 7693 The target machine's architecture. The OpenEmbedded build system 7694 supports many architectures. Here is an example list of architectures 7695 supported. This list is by no means complete as the architecture is 7696 configurable: 7697 7698 - arm 7699 - i586 7700 - x86_64 7701 - powerpc 7702 - powerpc64 7703 - mips 7704 - mipsel 7705 7706 For additional information on machine architectures, see the 7707 :term:`TUNE_ARCH` variable. 7708 7709 :term:`TARGET_AS_ARCH` 7710 Specifies architecture-specific assembler flags for the target 7711 system. :term:`TARGET_AS_ARCH` is initialized from 7712 :term:`TUNE_ASARGS` by default in the BitBake 7713 configuration file (``meta/conf/bitbake.conf``):: 7714 7715 TARGET_AS_ARCH = "${TUNE_ASARGS}" 7716 7717 :term:`TARGET_CC_ARCH` 7718 Specifies architecture-specific C compiler flags for the target 7719 system. :term:`TARGET_CC_ARCH` is initialized from 7720 :term:`TUNE_CCARGS` by default. 7721 7722 .. note:: 7723 7724 It is a common workaround to append :term:`LDFLAGS` to 7725 :term:`TARGET_CC_ARCH` in recipes that build software for the target that 7726 would not otherwise respect the exported :term:`LDFLAGS` variable. 7727 7728 :term:`TARGET_CC_KERNEL_ARCH` 7729 This is a specific kernel compiler flag for a CPU or Application 7730 Binary Interface (ABI) tune. The flag is used rarely and only for 7731 cases where a userspace :term:`TUNE_CCARGS` is not 7732 compatible with the kernel compilation. The :term:`TARGET_CC_KERNEL_ARCH` 7733 variable allows the kernel (and associated modules) to use a 7734 different configuration. See the 7735 ``meta/conf/machine/include/arm/feature-arm-thumb.inc`` file in the 7736 :term:`Source Directory` for an example. 7737 7738 :term:`TARGET_CFLAGS` 7739 Specifies the flags to pass to the C compiler when building for the 7740 target. When building in the target context, 7741 :term:`CFLAGS` is set to the value of this variable by 7742 default. 7743 7744 Additionally, the SDK's environment setup script sets the :term:`CFLAGS` 7745 variable in the environment to the :term:`TARGET_CFLAGS` value so that 7746 executables built using the SDK also have the flags applied. 7747 7748 :term:`TARGET_CPPFLAGS` 7749 Specifies the flags to pass to the C pre-processor (i.e. to both the 7750 C and the C++ compilers) when building for the target. When building 7751 in the target context, :term:`CPPFLAGS` is set to the 7752 value of this variable by default. 7753 7754 Additionally, the SDK's environment setup script sets the 7755 :term:`CPPFLAGS` variable in the environment to the :term:`TARGET_CPPFLAGS` 7756 value so that executables built using the SDK also have the flags 7757 applied. 7758 7759 :term:`TARGET_CXXFLAGS` 7760 Specifies the flags to pass to the C++ compiler when building for the 7761 target. When building in the target context, 7762 :term:`CXXFLAGS` is set to the value of this variable 7763 by default. 7764 7765 Additionally, the SDK's environment setup script sets the 7766 :term:`CXXFLAGS` variable in the environment to the :term:`TARGET_CXXFLAGS` 7767 value so that executables built using the SDK also have the flags 7768 applied. 7769 7770 :term:`TARGET_FPU` 7771 Specifies the method for handling FPU code. For FPU-less targets, 7772 which include most ARM CPUs, the variable must be set to "soft". If 7773 not, the kernel emulation gets used, which results in a performance 7774 penalty. 7775 7776 :term:`TARGET_LD_ARCH` 7777 Specifies architecture-specific linker flags for the target system. 7778 :term:`TARGET_LD_ARCH` is initialized from 7779 :term:`TUNE_LDARGS` by default in the BitBake 7780 configuration file (``meta/conf/bitbake.conf``):: 7781 7782 TARGET_LD_ARCH = "${TUNE_LDARGS}" 7783 7784 :term:`TARGET_LDFLAGS` 7785 Specifies the flags to pass to the linker when building for the 7786 target. When building in the target context, 7787 :term:`LDFLAGS` is set to the value of this variable 7788 by default. 7789 7790 Additionally, the SDK's environment setup script sets the 7791 :term:`LDFLAGS` variable in the environment to the 7792 :term:`TARGET_LDFLAGS` value so that executables built using the SDK also 7793 have the flags applied. 7794 7795 :term:`TARGET_OS` 7796 Specifies the target's operating system. The variable can be set to 7797 "linux" for glibc-based systems (GNU C Library) and to "linux-musl" 7798 for musl libc. For ARM/EABI targets, the possible values are 7799 "linux-gnueabi" and "linux-musleabi". 7800 7801 :term:`TARGET_PREFIX` 7802 Specifies the prefix used for the toolchain binary target tools. 7803 7804 Depending on the type of recipe and the build target, 7805 :term:`TARGET_PREFIX` is set as follows: 7806 7807 - For recipes building for the target machine, the value is 7808 "${:term:`TARGET_SYS`}-". 7809 7810 - For native recipes, the build system sets the variable to the 7811 value of :term:`BUILD_PREFIX`. 7812 7813 - For native SDK recipes (``nativesdk``), the build system sets the 7814 variable to the value of :term:`SDK_PREFIX`. 7815 7816 :term:`TARGET_SYS` 7817 Specifies the system, including the architecture and the operating 7818 system, for which the build is occurring in the context of the 7819 current recipe. 7820 7821 The OpenEmbedded build system automatically sets this variable based 7822 on :term:`TARGET_ARCH`, 7823 :term:`TARGET_VENDOR`, and 7824 :term:`TARGET_OS` variables. 7825 7826 .. note:: 7827 7828 You do not need to set the :term:`TARGET_SYS` variable yourself. 7829 7830 Consider these two examples: 7831 7832 - Given a native recipe on a 32-bit, x86 machine running Linux, the 7833 value is "i686-linux". 7834 7835 - Given a recipe being built for a little-endian, MIPS target 7836 running Linux, the value might be "mipsel-linux". 7837 7838 :term:`TARGET_VENDOR` 7839 Specifies the name of the target vendor. 7840 7841 :term:`TCLIBC` 7842 Specifies the GNU standard C library (``libc``) variant to use during 7843 the build process. 7844 7845 You can select "glibc", "musl", "newlib", or "baremetal". 7846 7847 :term:`TCLIBCAPPEND` 7848 Specifies a suffix to be appended onto the 7849 :term:`TMPDIR` value. The suffix identifies the 7850 ``libc`` variant for building. When you are building for multiple 7851 variants with the same :term:`Build Directory`, this 7852 mechanism ensures that output for different ``libc`` variants is kept 7853 separate to avoid potential conflicts. 7854 7855 In the ``defaultsetup.conf`` file, the default value of 7856 :term:`TCLIBCAPPEND` is "-${TCLIBC}". However, distros such as poky, 7857 which normally only support one ``libc`` variant, set 7858 :term:`TCLIBCAPPEND` to "" in their distro configuration file resulting 7859 in no suffix being applied. 7860 7861 :term:`TCMODE` 7862 Specifies the toolchain selector. :term:`TCMODE` controls the 7863 characteristics of the generated packages and images by telling the 7864 OpenEmbedded build system which toolchain profile to use. By default, 7865 the OpenEmbedded build system builds its own internal toolchain. The 7866 variable's default value is "default", which uses that internal 7867 toolchain. 7868 7869 .. note:: 7870 7871 If :term:`TCMODE` is set to a value other than "default", then it is your 7872 responsibility to ensure that the toolchain is compatible with the 7873 default toolchain. Using older or newer versions of these 7874 components might cause build problems. See the Release Notes for 7875 the Yocto Project release for the specific components with which 7876 the toolchain must be compatible. To access the Release Notes, go 7877 to the :yocto_home:`Downloads </software-overview/downloads>` 7878 page on the Yocto Project website and click on the "RELEASE 7879 INFORMATION" link for the appropriate release. 7880 7881 The :term:`TCMODE` variable is similar to :term:`TCLIBC`, 7882 which controls the variant of the GNU standard C library (``libc``) 7883 used during the build process: ``glibc`` or ``musl``. 7884 7885 With additional layers, it is possible to use a pre-compiled external 7886 toolchain. One example is the Sourcery G++ Toolchain. The support for 7887 this toolchain resides in the separate Mentor Graphics 7888 ``meta-sourcery`` layer at 7889 https://github.com/MentorEmbedded/meta-sourcery/. 7890 7891 The layer's ``README`` file contains information on how to use the 7892 Sourcery G++ Toolchain as an external toolchain. In summary, you must 7893 be sure to add the layer to your ``bblayers.conf`` file in front of 7894 the ``meta`` layer and then set the ``EXTERNAL_TOOLCHAIN`` variable 7895 in your ``local.conf`` file to the location in which you installed 7896 the toolchain. 7897 7898 The fundamentals used for this example apply to any external 7899 toolchain. You can use ``meta-sourcery`` as a template for adding 7900 support for other external toolchains. 7901 7902 :term:`TEMPLATECONF` 7903 Specifies the directory used by the build system to find templates 7904 from which to build the ``bblayers.conf`` and ``local.conf`` files. 7905 Use this variable if you wish to customize such files, and the default 7906 BitBake targets shown when sourcing the ``oe-init-build-env`` script. 7907 7908 For details, see the 7909 :ref:`dev-manual/common-tasks:creating a custom template configuration directory` 7910 section in the Yocto Project Development Tasks manual. 7911 7912 .. note:: 7913 7914 You must set this variable in the external environment in order 7915 for it to work. 7916 7917 :term:`TEST_EXPORT_DIR` 7918 The location the OpenEmbedded build system uses to export tests when 7919 the :term:`TEST_EXPORT_ONLY` variable is set 7920 to "1". 7921 7922 The :term:`TEST_EXPORT_DIR` variable defaults to 7923 ``"${TMPDIR}/testimage/${PN}"``. 7924 7925 :term:`TEST_EXPORT_ONLY` 7926 Specifies to export the tests only. Set this variable to "1" if you 7927 do not want to run the tests but you want them to be exported in a 7928 manner that you to run them outside of the build system. 7929 7930 :term:`TEST_LOG_DIR` 7931 Holds the SSH log and the boot log for QEMU machines. The 7932 :term:`TEST_LOG_DIR` variable defaults to ``"${WORKDIR}/testimage"``. 7933 7934 .. note:: 7935 7936 Actual test results reside in the task log (``log.do_testimage``), 7937 which is in the ``${WORKDIR}/temp/`` directory. 7938 7939 :term:`TEST_POWERCONTROL_CMD` 7940 For automated hardware testing, specifies the command to use to 7941 control the power of the target machine under test. Typically, this 7942 command would point to a script that performs the appropriate action 7943 (e.g. interacting with a web-enabled power strip). The specified 7944 command should expect to receive as the last argument "off", "on" or 7945 "cycle" specifying to power off, on, or cycle (power off and then 7946 power on) the device, respectively. 7947 7948 :term:`TEST_POWERCONTROL_EXTRA_ARGS` 7949 For automated hardware testing, specifies additional arguments to 7950 pass through to the command specified in 7951 :term:`TEST_POWERCONTROL_CMD`. Setting 7952 :term:`TEST_POWERCONTROL_EXTRA_ARGS` is optional. You can use it if you 7953 wish, for example, to separate the machine-specific and 7954 non-machine-specific parts of the arguments. 7955 7956 :term:`TEST_QEMUBOOT_TIMEOUT` 7957 The time in seconds allowed for an image to boot before automated 7958 runtime tests begin to run against an image. The default timeout 7959 period to allow the boot process to reach the login prompt is 500 7960 seconds. You can specify a different value in the ``local.conf`` 7961 file. 7962 7963 For more information on testing images, see the 7964 ":ref:`dev-manual/common-tasks:performing automated runtime testing`" 7965 section in the Yocto Project Development Tasks Manual. 7966 7967 :term:`TEST_SERIALCONTROL_CMD` 7968 For automated hardware testing, specifies the command to use to 7969 connect to the serial console of the target machine under test. This 7970 command simply needs to connect to the serial console and forward 7971 that connection to standard input and output as any normal terminal 7972 program does. 7973 7974 For example, to use the Picocom terminal program on serial device 7975 ``/dev/ttyUSB0`` at 115200bps, you would set the variable as follows:: 7976 7977 TEST_SERIALCONTROL_CMD = "picocom /dev/ttyUSB0 -b 115200" 7978 7979 :term:`TEST_SERIALCONTROL_EXTRA_ARGS` 7980 For automated hardware testing, specifies additional arguments to 7981 pass through to the command specified in 7982 :term:`TEST_SERIALCONTROL_CMD`. Setting 7983 :term:`TEST_SERIALCONTROL_EXTRA_ARGS` is optional. You can use it if you 7984 wish, for example, to separate the machine-specific and 7985 non-machine-specific parts of the command. 7986 7987 :term:`TEST_SERVER_IP` 7988 The IP address of the build machine (host machine). This IP address 7989 is usually automatically detected. However, if detection fails, this 7990 variable needs to be set to the IP address of the build machine (i.e. 7991 where the build is taking place). 7992 7993 .. note:: 7994 7995 The :term:`TEST_SERVER_IP` variable is only used for a small number of 7996 tests such as the "dnf" test suite, which needs to download packages 7997 from ``WORKDIR/oe-rootfs-repo``. 7998 7999 :term:`TEST_SUITES` 8000 An ordered list of tests (modules) to run against an image when 8001 performing automated runtime testing. 8002 8003 The OpenEmbedded build system provides a core set of tests that can 8004 be used against images. 8005 8006 .. note:: 8007 8008 Currently, there is only support for running these tests under 8009 QEMU. 8010 8011 Tests include ``ping``, ``ssh``, ``df`` among others. You can add 8012 your own tests to the list of tests by appending :term:`TEST_SUITES` as 8013 follows:: 8014 8015 TEST_SUITES:append = " mytest" 8016 8017 Alternatively, you can 8018 provide the "auto" option to have all applicable tests run against 8019 the image. 8020 :: 8021 8022 TEST_SUITES:append = " auto" 8023 8024 Using this option causes the 8025 build system to automatically run tests that are applicable to the 8026 image. Tests that are not applicable are skipped. 8027 8028 The order in which tests are run is important. Tests that depend on 8029 another test must appear later in the list than the test on which 8030 they depend. For example, if you append the list of tests with two 8031 tests (``test_A`` and ``test_B``) where ``test_B`` is dependent on 8032 ``test_A``, then you must order the tests as follows:: 8033 8034 TEST_SUITES = "test_A test_B" 8035 8036 For more information on testing images, see the 8037 ":ref:`dev-manual/common-tasks:performing automated runtime testing`" 8038 section in the Yocto Project Development Tasks Manual. 8039 8040 :term:`TEST_TARGET` 8041 Specifies the target controller to use when running tests against a 8042 test image. The default controller to use is "qemu":: 8043 8044 TEST_TARGET = "qemu" 8045 8046 A target controller is a class that defines how an image gets 8047 deployed on a target and how a target is started. A layer can extend 8048 the controllers by adding a module in the layer's 8049 ``/lib/oeqa/controllers`` directory and by inheriting the 8050 ``BaseTarget`` class, which is an abstract class that cannot be used 8051 as a value of :term:`TEST_TARGET`. 8052 8053 You can provide the following arguments with :term:`TEST_TARGET`: 8054 8055 - *"qemu":* Boots a QEMU image and runs the tests. See the 8056 ":ref:`dev-manual/common-tasks:enabling runtime tests on qemu`" section 8057 in the Yocto Project Development Tasks Manual for more 8058 information. 8059 8060 - *"simpleremote":* Runs the tests on target hardware that is 8061 already up and running. The hardware can be on the network or it 8062 can be a device running an image on QEMU. You must also set 8063 :term:`TEST_TARGET_IP` when you use 8064 "simpleremote". 8065 8066 .. note:: 8067 8068 This argument is defined in 8069 ``meta/lib/oeqa/controllers/simpleremote.py``. 8070 8071 For information on running tests on hardware, see the 8072 ":ref:`dev-manual/common-tasks:enabling runtime tests on hardware`" 8073 section in the Yocto Project Development Tasks Manual. 8074 8075 :term:`TEST_TARGET_IP` 8076 The IP address of your hardware under test. The :term:`TEST_TARGET_IP` 8077 variable has no effect when :term:`TEST_TARGET` is 8078 set to "qemu". 8079 8080 When you specify the IP address, you can also include a port. Here is 8081 an example:: 8082 8083 TEST_TARGET_IP = "192.168.1.4:2201" 8084 8085 Specifying a port is 8086 useful when SSH is started on a non-standard port or in cases when 8087 your hardware under test is behind a firewall or network that is not 8088 directly accessible from your host and you need to do port address 8089 translation. 8090 8091 :term:`TESTIMAGE_AUTO` 8092 Automatically runs the series of automated tests for images when an 8093 image is successfully built. Setting :term:`TESTIMAGE_AUTO` to "1" causes 8094 any image that successfully builds to automatically boot under QEMU. 8095 Using the variable also adds in dependencies so that any SDK for 8096 which testing is requested is automatically built first. 8097 8098 These tests are written in Python making use of the ``unittest`` 8099 module, and the majority of them run commands on the target system 8100 over ``ssh``. You can set this variable to "1" in your ``local.conf`` 8101 file in the :term:`Build Directory` to have the 8102 OpenEmbedded build system automatically run these tests after an 8103 image successfully builds: 8104 8105 TESTIMAGE_AUTO = "1" 8106 8107 For more information 8108 on enabling, running, and writing these tests, see the 8109 ":ref:`dev-manual/common-tasks:performing automated runtime testing`" 8110 section in the Yocto Project Development Tasks Manual and the 8111 ":ref:`ref-classes-testimage*`" section. 8112 8113 :term:`THISDIR` 8114 The directory in which the file BitBake is currently parsing is 8115 located. Do not manually set this variable. 8116 8117 :term:`TIME` 8118 The time the build was started. Times appear using the hour, minute, 8119 and second (HMS) format (e.g. "140159" for one minute and fifty-nine 8120 seconds past 1400 hours). 8121 8122 :term:`TMPDIR` 8123 This variable is the base directory the OpenEmbedded build system 8124 uses for all build output and intermediate files (other than the 8125 shared state cache). By default, the :term:`TMPDIR` variable points to 8126 ``tmp`` within the :term:`Build Directory`. 8127 8128 If you want to establish this directory in a location other than the 8129 default, you can uncomment and edit the following statement in the 8130 ``conf/local.conf`` file in the :term:`Source Directory`:: 8131 8132 #TMPDIR = "${TOPDIR}/tmp" 8133 8134 An example use for this scenario is to set :term:`TMPDIR` to a local disk, 8135 which does not use NFS, while having the Build Directory use NFS. 8136 8137 The filesystem used by :term:`TMPDIR` must have standard filesystem 8138 semantics (i.e. mixed-case files are unique, POSIX file locking, and 8139 persistent inodes). Due to various issues with NFS and bugs in some 8140 implementations, NFS does not meet this minimum requirement. 8141 Consequently, :term:`TMPDIR` cannot be on NFS. 8142 8143 :term:`TOOLCHAIN_HOST_TASK` 8144 This variable lists packages the OpenEmbedded build system uses when 8145 building an SDK, which contains a cross-development environment. The 8146 packages specified by this variable are part of the toolchain set 8147 that runs on the :term:`SDKMACHINE`, and each 8148 package should usually have the prefix ``nativesdk-``. For example, 8149 consider the following command when building an SDK:: 8150 8151 $ bitbake -c populate_sdk imagename 8152 8153 In this case, a default list of packages is 8154 set in this variable, but you can add additional packages to the 8155 list. See the 8156 ":ref:`sdk-manual/appendix-customizing-standard:adding individual packages to the standard sdk`" section 8157 in the Yocto Project Application Development and the Extensible 8158 Software Development Kit (eSDK) manual for more information. 8159 8160 For background information on cross-development toolchains in the 8161 Yocto Project development environment, see the 8162 ":ref:`sdk-manual/intro:the cross-development toolchain`" 8163 section in the Yocto Project Overview and Concepts Manual. For 8164 information on setting up a cross-development environment, see the 8165 :doc:`/sdk-manual/index` manual. 8166 8167 Note that this variable applies to building an SDK, not an eSDK, 8168 in which case the term:`TOOLCHAIN_HOST_TASK_ESDK` setting should be 8169 used instead. 8170 8171 :term:`TOOLCHAIN_HOST_TASK_ESDK` 8172 This variable allows to extend what is installed in the host 8173 portion of an eSDK. This is similar to :term:`TOOLCHAIN_HOST_TASK` 8174 applying to SDKs. 8175 8176 :term:`TOOLCHAIN_OUTPUTNAME` 8177 This variable defines the name used for the toolchain output. The 8178 :ref:`populate_sdk_base <ref-classes-populate-sdk-*>` class sets 8179 the :term:`TOOLCHAIN_OUTPUTNAME` variable as follows:: 8180 8181 TOOLCHAIN_OUTPUTNAME ?= "${SDK_NAME}-toolchain-${SDK_VERSION}" 8182 8183 See 8184 the :term:`SDK_NAME` and 8185 :term:`SDK_VERSION` variables for additional 8186 information. 8187 8188 :term:`TOOLCHAIN_TARGET_TASK` 8189 This variable lists packages the OpenEmbedded build system uses when 8190 it creates the target part of an SDK (i.e. the part built for the 8191 target hardware), which includes libraries and headers. Use this 8192 variable to add individual packages to the part of the SDK that runs 8193 on the target. See the 8194 ":ref:`sdk-manual/appendix-customizing-standard:adding individual packages to the standard sdk`" section 8195 in the Yocto Project Application Development and the Extensible 8196 Software Development Kit (eSDK) manual for more information. 8197 8198 For background information on cross-development toolchains in the 8199 Yocto Project development environment, see the 8200 ":ref:`sdk-manual/intro:the cross-development toolchain`" 8201 section in the Yocto Project Overview and Concepts Manual. For 8202 information on setting up a cross-development environment, see the 8203 :doc:`/sdk-manual/index` manual. 8204 8205 :term:`TRANSLATED_TARGET_ARCH` 8206 A sanitized version of :term:`TARGET_ARCH`. This 8207 variable is used where the architecture is needed in a value where 8208 underscores are not allowed, for example within package filenames. In 8209 this case, dash characters replace any underscore characters used in 8210 :term:`TARGET_ARCH`. 8211 8212 Do not edit this variable. 8213 8214 :term:`TUNE_ARCH` 8215 The GNU canonical architecture for a specific architecture (i.e. 8216 ``arm``, ``armeb``, ``mips``, ``mips64``, and so forth). BitBake uses 8217 this value to setup configuration. 8218 8219 :term:`TUNE_ARCH` definitions are specific to a given architecture. The 8220 definitions can be a single static definition, or can be dynamically 8221 adjusted. You can see details for a given CPU family by looking at 8222 the architecture's ``README`` file. For example, the 8223 ``meta/conf/machine/include/mips/README`` file in the 8224 :term:`Source Directory` provides information for 8225 :term:`TUNE_ARCH` specific to the ``mips`` architecture. 8226 8227 :term:`TUNE_ARCH` is tied closely to 8228 :term:`TARGET_ARCH`, which defines the target 8229 machine's architecture. The BitBake configuration file 8230 (``meta/conf/bitbake.conf``) sets :term:`TARGET_ARCH` as follows:: 8231 8232 TARGET_ARCH = "${TUNE_ARCH}" 8233 8234 The following list, which is by no means complete since architectures 8235 are configurable, shows supported machine architectures: 8236 8237 - arm 8238 - i586 8239 - x86_64 8240 - powerpc 8241 - powerpc64 8242 - mips 8243 - mipsel 8244 8245 :term:`TUNE_ASARGS` 8246 Specifies architecture-specific assembler flags for the target 8247 system. The set of flags is based on the selected tune features. 8248 :term:`TUNE_ASARGS` is set using the tune include files, which are 8249 typically under ``meta/conf/machine/include/`` and are influenced 8250 through :term:`TUNE_FEATURES`. For example, the 8251 ``meta/conf/machine/include/x86/arch-x86.inc`` file defines the flags 8252 for the x86 architecture as follows:: 8253 8254 TUNE_ASARGS += "${@bb.utils.contains("TUNE_FEATURES", "mx32", "-x32", "", d)}" 8255 8256 .. note:: 8257 8258 Board Support Packages (BSPs) select the tune. The selected tune, 8259 in turn, affects the tune variables themselves (i.e. the tune can 8260 supply its own set of flags). 8261 8262 :term:`TUNE_CCARGS` 8263 Specifies architecture-specific C compiler flags for the target 8264 system. The set of flags is based on the selected tune features. 8265 :term:`TUNE_CCARGS` is set using the tune include files, which are 8266 typically under ``meta/conf/machine/include/`` and are influenced 8267 through :term:`TUNE_FEATURES`. 8268 8269 .. note:: 8270 8271 Board Support Packages (BSPs) select the tune. The selected tune, 8272 in turn, affects the tune variables themselves (i.e. the tune can 8273 supply its own set of flags). 8274 8275 :term:`TUNE_FEATURES` 8276 Features used to "tune" a compiler for optimal use given a specific 8277 processor. The features are defined within the tune files and allow 8278 arguments (i.e. ``TUNE_*ARGS``) to be dynamically generated based on 8279 the features. 8280 8281 The OpenEmbedded build system verifies the features to be sure they 8282 are not conflicting and that they are supported. 8283 8284 The BitBake configuration file (``meta/conf/bitbake.conf``) defines 8285 :term:`TUNE_FEATURES` as follows:: 8286 8287 TUNE_FEATURES ??= "${TUNE_FEATURES:tune-${DEFAULTTUNE}}" 8288 8289 See the :term:`DEFAULTTUNE` variable for more information. 8290 8291 :term:`TUNE_LDARGS` 8292 Specifies architecture-specific linker flags for the target system. 8293 The set of flags is based on the selected tune features. 8294 :term:`TUNE_LDARGS` is set using the tune include files, which are 8295 typically under ``meta/conf/machine/include/`` and are influenced 8296 through :term:`TUNE_FEATURES`. For example, the 8297 ``meta/conf/machine/include/x86/arch-x86.inc`` file defines the flags 8298 for the x86 architecture as follows:: 8299 8300 TUNE_LDARGS += "${@bb.utils.contains("TUNE_FEATURES", "mx32", "-m elf32_x86_64", "", d)}" 8301 8302 .. note:: 8303 8304 Board Support Packages (BSPs) select the tune. The selected tune, 8305 in turn, affects the tune variables themselves (i.e. the tune can 8306 supply its own set of flags). 8307 8308 :term:`TUNE_PKGARCH` 8309 The package architecture understood by the packaging system to define 8310 the architecture, ABI, and tuning of output packages. The specific 8311 tune is defined using the "_tune" override as follows:: 8312 8313 TUNE_PKGARCH:tune-tune = "tune" 8314 8315 These tune-specific package architectures are defined in the machine 8316 include files. Here is an example of the "core2-32" tuning as used in 8317 the ``meta/conf/machine/include/x86/tune-core2.inc`` file:: 8318 8319 TUNE_PKGARCH:tune-core2-32 = "core2-32" 8320 8321 :term:`TUNECONFLICTS[feature]` 8322 Specifies CPU or Application Binary Interface (ABI) tuning features 8323 that conflict with feature. 8324 8325 Known tuning conflicts are specified in the machine include files in 8326 the :term:`Source Directory`. Here is an example from 8327 the ``meta/conf/machine/include/mips/arch-mips.inc`` include file 8328 that lists the "o32" and "n64" features as conflicting with the "n32" 8329 feature:: 8330 8331 TUNECONFLICTS[n32] = "o32 n64" 8332 8333 :term:`TUNEVALID[feature]` 8334 Specifies a valid CPU or Application Binary Interface (ABI) tuning 8335 feature. The specified feature is stored as a flag. Valid features 8336 are specified in the machine include files (e.g. 8337 ``meta/conf/machine/include/arm/arch-arm.inc``). Here is an example 8338 from that file:: 8339 8340 TUNEVALID[bigendian] = "Enable big-endian mode." 8341 8342 See the machine include files in the :term:`Source Directory` 8343 for these features. 8344 8345 :term:`UBOOT_CONFIG` 8346 Configures the :term:`UBOOT_MACHINE` and can 8347 also define :term:`IMAGE_FSTYPES` for individual 8348 cases. 8349 8350 Following is an example from the ``meta-fsl-arm`` layer. :: 8351 8352 UBOOT_CONFIG ??= "sd" 8353 UBOOT_CONFIG[sd] = "mx6qsabreauto_config,sdcard" 8354 UBOOT_CONFIG[eimnor] = "mx6qsabreauto_eimnor_config" 8355 UBOOT_CONFIG[nand] = "mx6qsabreauto_nand_config,ubifs" 8356 UBOOT_CONFIG[spinor] = "mx6qsabreauto_spinor_config" 8357 8358 In this example, "sd" is selected as the configuration of the possible four for the 8359 :term:`UBOOT_MACHINE`. The "sd" configuration defines 8360 "mx6qsabreauto_config" as the value for :term:`UBOOT_MACHINE`, while the 8361 "sdcard" specifies the :term:`IMAGE_FSTYPES` to use for the U-Boot image. 8362 8363 For more information on how the :term:`UBOOT_CONFIG` is handled, see the 8364 :ref:`uboot-config <ref-classes-uboot-config>` 8365 class. 8366 8367 :term:`UBOOT_DTB_LOADADDRESS` 8368 Specifies the load address for the dtb image used by U-Boot. During FIT 8369 image creation, the :term:`UBOOT_DTB_LOADADDRESS` variable is used in 8370 :ref:`kernel-fitimage <ref-classes-kernel-fitimage>` class to specify 8371 the load address to be used in 8372 creating the dtb sections of Image Tree Source for the FIT image. 8373 8374 :term:`UBOOT_DTBO_LOADADDRESS` 8375 Specifies the load address for the dtbo image used by U-Boot. During FIT 8376 image creation, the :term:`UBOOT_DTBO_LOADADDRESS` variable is used in 8377 :ref:`kernel-fitimage <ref-classes-kernel-fitimage>` class to specify the load address to be used in 8378 creating the dtbo sections of Image Tree Source for the FIT image. 8379 8380 :term:`UBOOT_ENTRYPOINT` 8381 Specifies the entry point for the U-Boot image. During U-Boot image 8382 creation, the :term:`UBOOT_ENTRYPOINT` variable is passed as a 8383 command-line parameter to the ``uboot-mkimage`` utility. 8384 8385 :term:`UBOOT_LOADADDRESS` 8386 Specifies the load address for the U-Boot image. During U-Boot image 8387 creation, the :term:`UBOOT_LOADADDRESS` variable is passed as a 8388 command-line parameter to the ``uboot-mkimage`` utility. 8389 8390 :term:`UBOOT_LOCALVERSION` 8391 Appends a string to the name of the local version of the U-Boot 8392 image. For example, assuming the version of the U-Boot image built 8393 was "2013.10", the full version string reported by U-Boot would be 8394 "2013.10-yocto" given the following statement:: 8395 8396 UBOOT_LOCALVERSION = "-yocto" 8397 8398 :term:`UBOOT_MACHINE` 8399 Specifies the value passed on the ``make`` command line when building 8400 a U-Boot image. The value indicates the target platform 8401 configuration. You typically set this variable from the machine 8402 configuration file (i.e. ``conf/machine/machine_name.conf``). 8403 8404 Please see the "Selection of Processor Architecture and Board Type" 8405 section in the U-Boot README for valid values for this variable. 8406 8407 :term:`UBOOT_MAKE_TARGET` 8408 Specifies the target called in the ``Makefile``. The default target 8409 is "all". 8410 8411 :term:`UBOOT_MKIMAGE` 8412 Specifies the name of the mkimage command as used by the 8413 :ref:`kernel-fitimage <ref-classes-kernel-fitimage>` class to assemble 8414 the FIT image. This can be used to substitute an alternative command, wrapper 8415 script or function if desired. The default is "uboot-mkimage". 8416 8417 :term:`UBOOT_MKIMAGE_DTCOPTS` 8418 Options for the device tree compiler passed to mkimage '-D' 8419 feature while creating FIT image in :ref:`kernel-fitimage <ref-classes-kernel-fitimage>` class. 8420 If :term:`UBOOT_MKIMAGE_DTCOPTS` is not set then kernel-fitimage will not 8421 pass the ``-D`` option to mkimage. 8422 8423 :term:`UBOOT_MKIMAGE_SIGN` 8424 Specifies the name of the mkimage command as used by the 8425 :ref:`kernel-fitimage <ref-classes-kernel-fitimage>` class to sign 8426 the FIT image after it has been assembled (if enabled). This can be used 8427 to substitute an alternative command, wrapper script or function if 8428 desired. The default is "${:term:`UBOOT_MKIMAGE`}". 8429 8430 :term:`UBOOT_MKIMAGE_SIGN_ARGS` 8431 Optionally specifies additional arguments for the 8432 :ref:`kernel-fitimage <ref-classes-kernel-fitimage>` class to pass to the 8433 mkimage command when signing the FIT image. 8434 8435 :term:`UBOOT_RD_ENTRYPOINT` 8436 Specifies the entrypoint for the RAM disk image. 8437 During FIT image creation, the 8438 :term:`UBOOT_RD_ENTRYPOINT` variable is used 8439 in :ref:`kernel-fitimage <ref-classes-kernel-fitimage>` class to specify the 8440 entrypoint to be used in creating the Image Tree Source for 8441 the FIT image. 8442 8443 :term:`UBOOT_RD_LOADADDRESS` 8444 Specifies the load address for the RAM disk image. 8445 During FIT image creation, the 8446 :term:`UBOOT_RD_LOADADDRESS` variable is used 8447 in :ref:`kernel-fitimage <ref-classes-kernel-fitimage>` class to specify the 8448 load address to be used in creating the Image Tree Source for 8449 the FIT image. 8450 8451 :term:`UBOOT_SIGN_ENABLE` 8452 Enable signing of FIT image. The default value is "0". 8453 8454 :term:`UBOOT_SIGN_KEYDIR` 8455 Location of the directory containing the RSA key and 8456 certificate used for signing FIT image. 8457 8458 :term:`UBOOT_SIGN_KEYNAME` 8459 The name of keys used for signing U-Boot FIT image stored in 8460 :term:`UBOOT_SIGN_KEYDIR` directory. For e.g. dev.key key and dev.crt 8461 certificate stored in :term:`UBOOT_SIGN_KEYDIR` directory will have 8462 :term:`UBOOT_SIGN_KEYNAME` set to "dev". 8463 8464 :term:`UBOOT_SUFFIX` 8465 Points to the generated U-Boot extension. For example, ``u-boot.sb`` 8466 has a ``.sb`` extension. 8467 8468 The default U-Boot extension is ``.bin`` 8469 8470 :term:`UBOOT_TARGET` 8471 Specifies the target used for building U-Boot. The target is passed 8472 directly as part of the "make" command (e.g. SPL and AIS). If you do 8473 not specifically set this variable, the OpenEmbedded build process 8474 passes and uses "all" for the target during the U-Boot building 8475 process. 8476 8477 :term:`UNKNOWN_CONFIGURE_OPT_IGNORE` 8478 Specifies a list of options that, if reported by the configure script 8479 as being invalid, should not generate a warning during the 8480 :ref:`ref-tasks-configure` task. Normally, invalid 8481 configure options are simply not passed to the configure script (e.g. 8482 should be removed from :term:`EXTRA_OECONF` or 8483 :term:`PACKAGECONFIG_CONFARGS`). 8484 However, there are common options that are passed to all 8485 configure scripts at a class level, but might not be valid for some 8486 configure scripts. Therefore warnings about these options are useless. 8487 For these cases, the options are added to :term:`UNKNOWN_CONFIGURE_OPT_IGNORE`. 8488 8489 The configure arguments check that uses 8490 :term:`UNKNOWN_CONFIGURE_OPT_IGNORE` is part of the 8491 :ref:`insane <ref-classes-insane>` class and is only enabled if the 8492 recipe inherits the :ref:`autotools <ref-classes-autotools>` class. 8493 8494 :term:`UPDATERCPN` 8495 For recipes inheriting the 8496 :ref:`update-rc.d <ref-classes-update-rc.d>` class, :term:`UPDATERCPN` 8497 specifies the package that contains the initscript that is enabled. 8498 8499 The default value is "${PN}". Given that almost all recipes that 8500 install initscripts package them in the main package for the recipe, 8501 you rarely need to set this variable in individual recipes. 8502 8503 :term:`UPSTREAM_CHECK_COMMITS` 8504 You can perform a per-recipe check for what the latest upstream 8505 source code version is by calling ``devtool latest-version recipe``. If 8506 the recipe source code is provided from Git repositories, but 8507 releases are not identified by Git tags, set :term:`UPSTREAM_CHECK_COMMITS` 8508 to ``1`` in the recipe, and the OpenEmbedded build system 8509 will compare the latest commit with the one currently specified 8510 by the recipe (:term:`SRCREV`). 8511 :: 8512 8513 UPSTREAM_CHECK_COMMITS = "1" 8514 8515 :term:`UPSTREAM_CHECK_GITTAGREGEX` 8516 You can perform a per-recipe check for what the latest upstream 8517 source code version is by calling ``devtool latest-version recipe``. If 8518 the recipe source code is provided from Git repositories, the 8519 OpenEmbedded build system determines the latest upstream version by 8520 picking the latest tag from the list of all repository tags. 8521 8522 You can use the :term:`UPSTREAM_CHECK_GITTAGREGEX` variable to provide a 8523 regular expression to filter only the relevant tags should the 8524 default filter not work correctly. 8525 :: 8526 8527 UPSTREAM_CHECK_GITTAGREGEX = "git_tag_regex" 8528 8529 :term:`UPSTREAM_CHECK_REGEX` 8530 Use the :term:`UPSTREAM_CHECK_REGEX` variable to specify a different 8531 regular expression instead of the default one when the package 8532 checking system is parsing the page found using 8533 :term:`UPSTREAM_CHECK_URI`. 8534 :: 8535 8536 UPSTREAM_CHECK_REGEX = "package_regex" 8537 8538 :term:`UPSTREAM_CHECK_URI` 8539 You can perform a per-recipe check for what the latest upstream 8540 source code version is by calling ``devtool latest-version recipe``. If 8541 the source code is provided from tarballs, the latest version is 8542 determined by fetching the directory listing where the tarball is and 8543 attempting to find a later tarball. When this approach does not work, 8544 you can use :term:`UPSTREAM_CHECK_URI` to provide a different URI that 8545 contains the link to the latest tarball. 8546 :: 8547 8548 UPSTREAM_CHECK_URI = "recipe_url" 8549 8550 :term:`UPSTREAM_VERSION_UNKNOWN` 8551 You can perform a per-recipe check for what the latest upstream 8552 source code version is by calling ``devtool latest-version recipe``. 8553 If no combination of the :term:`UPSTREAM_CHECK_URI`, :term:`UPSTREAM_CHECK_REGEX`, 8554 :term:`UPSTREAM_CHECK_GITTAGREGEX` and :term:`UPSTREAM_CHECK_COMMITS` variables in 8555 the recipe allows to determine what the latest upstream version is, 8556 you can set :term:`UPSTREAM_VERSION_UNKNOWN` to ``1`` in the recipe 8557 to acknowledge that the check cannot be performed. 8558 :: 8559 8560 UPSTREAM_VERSION_UNKNOWN = "1" 8561 8562 :term:`USE_DEVFS` 8563 Determines if ``devtmpfs`` is used for ``/dev`` population. The 8564 default value used for :term:`USE_DEVFS` is "1" when no value is 8565 specifically set. Typically, you would set :term:`USE_DEVFS` to "0" for a 8566 statically populated ``/dev`` directory. 8567 8568 See the ":ref:`dev-manual/common-tasks:selecting a device manager`" section in 8569 the Yocto Project Development Tasks Manual for information on how to 8570 use this variable. 8571 8572 :term:`USE_VT` 8573 When using 8574 :ref:`SysVinit <dev-manual/common-tasks:enabling system services>`, 8575 determines whether or not to run a 8576 `getty <https://en.wikipedia.org/wiki/Getty_%28Unix%29>`__ on any 8577 virtual terminals in order to enable logging in through those 8578 terminals. 8579 8580 The default value used for :term:`USE_VT` is "1" when no default value is 8581 specifically set. Typically, you would set :term:`USE_VT` to "0" in the 8582 machine configuration file for machines that do not have a graphical 8583 display attached and therefore do not need virtual terminal 8584 functionality. 8585 8586 :term:`USER_CLASSES` 8587 A list of classes to globally inherit. These classes are used by the 8588 OpenEmbedded build system to enable extra features. 8589 8590 The default list is set in your ``local.conf`` file:: 8591 8592 USER_CLASSES ?= "buildstats" 8593 8594 For more information, see 8595 ``meta-poky/conf/local.conf.sample`` in the :term:`Source Directory`. 8596 8597 :term:`USERADD_ERROR_DYNAMIC` 8598 If set to ``error``, forces the OpenEmbedded build system to produce 8599 an error if the user identification (``uid``) and group 8600 identification (``gid``) values are not defined in any of the files 8601 listed in :term:`USERADD_UID_TABLES` and 8602 :term:`USERADD_GID_TABLES`. If set to 8603 ``warn``, a warning will be issued instead. 8604 8605 The default behavior for the build system is to dynamically apply 8606 ``uid`` and ``gid`` values. Consequently, the 8607 :term:`USERADD_ERROR_DYNAMIC` variable is by default not set. If you plan 8608 on using statically assigned ``gid`` and ``uid`` values, you should 8609 set the :term:`USERADD_ERROR_DYNAMIC` variable in your ``local.conf`` 8610 file as follows:: 8611 8612 USERADD_ERROR_DYNAMIC = "error" 8613 8614 Overriding the 8615 default behavior implies you are going to also take steps to set 8616 static ``uid`` and ``gid`` values through use of the 8617 :term:`USERADDEXTENSION`, 8618 :term:`USERADD_UID_TABLES`, and 8619 :term:`USERADD_GID_TABLES` variables. 8620 8621 .. note:: 8622 8623 There is a difference in behavior between setting 8624 :term:`USERADD_ERROR_DYNAMIC` to ``error`` and setting it to ``warn``. 8625 When it is set to ``warn``, the build system will report a warning for 8626 every undefined ``uid`` and ``gid`` in any recipe. But when it is set 8627 to ``error``, it will only report errors for recipes that are actually 8628 built. 8629 This saves you from having to add static IDs for recipes that you 8630 know will never be built. 8631 8632 :term:`USERADD_GID_TABLES` 8633 Specifies a password file to use for obtaining static group 8634 identification (``gid``) values when the OpenEmbedded build system 8635 adds a group to the system during package installation. 8636 8637 When applying static group identification (``gid``) values, the 8638 OpenEmbedded build system looks in :term:`BBPATH` for a 8639 ``files/group`` file and then applies those ``uid`` values. Set the 8640 variable as follows in your ``local.conf`` file:: 8641 8642 8643 USERADD_GID_TABLES = "files/group" 8644 8645 .. note:: 8646 8647 Setting the :term:`USERADDEXTENSION` variable to "useradd-staticids" 8648 causes the build system to use static ``gid`` values. 8649 8650 :term:`USERADD_PACKAGES` 8651 When inheriting the :ref:`useradd <ref-classes-useradd>` class, 8652 this variable specifies the individual packages within the recipe 8653 that require users and/or groups to be added. 8654 8655 You must set this variable if the recipe inherits the class. For 8656 example, the following enables adding a user for the main package in 8657 a recipe:: 8658 8659 USERADD_PACKAGES = "${PN}" 8660 8661 .. note:: 8662 8663 It follows that if you are going to use the :term:`USERADD_PACKAGES` 8664 variable, you need to set one or more of the :term:`USERADD_PARAM`, 8665 :term:`GROUPADD_PARAM`, or :term:`GROUPMEMS_PARAM` variables. 8666 8667 :term:`USERADD_PARAM` 8668 When inheriting the :ref:`useradd <ref-classes-useradd>` class, 8669 this variable specifies for a package what parameters should pass to 8670 the ``useradd`` command if you add a user to the system when the 8671 package is installed. 8672 8673 Here is an example from the ``dbus`` recipe:: 8674 8675 USERADD_PARAM:${PN} = "--system --home ${localstatedir}/lib/dbus \ 8676 --no-create-home --shell /bin/false \ 8677 --user-group messagebus" 8678 8679 For information on the 8680 standard Linux shell command ``useradd``, see 8681 https://linux.die.net/man/8/useradd. 8682 8683 :term:`USERADD_UID_TABLES` 8684 Specifies a password file to use for obtaining static user 8685 identification (``uid``) values when the OpenEmbedded build system 8686 adds a user to the system during package installation. 8687 8688 When applying static user identification (``uid``) values, the 8689 OpenEmbedded build system looks in :term:`BBPATH` for a 8690 ``files/passwd`` file and then applies those ``uid`` values. Set the 8691 variable as follows in your ``local.conf`` file:: 8692 8693 USERADD_UID_TABLES = "files/passwd" 8694 8695 .. note:: 8696 8697 Setting the :term:`USERADDEXTENSION` variable to "useradd-staticids" 8698 causes the build system to use static ``uid`` values. 8699 8700 :term:`USERADDEXTENSION` 8701 When set to "useradd-staticids", causes the OpenEmbedded build system 8702 to base all user and group additions on a static ``passwd`` and 8703 ``group`` files found in :term:`BBPATH`. 8704 8705 To use static user identification (``uid``) and group identification 8706 (``gid``) values, set the variable as follows in your ``local.conf`` 8707 file: USERADDEXTENSION = "useradd-staticids" 8708 8709 .. note:: 8710 8711 Setting this variable to use static ``uid`` and ``gid`` 8712 values causes the OpenEmbedded build system to employ the 8713 :ref:`ref-classes-useradd` class. 8714 8715 If you use static ``uid`` and ``gid`` information, you must also 8716 specify the ``files/passwd`` and ``files/group`` files by setting the 8717 :term:`USERADD_UID_TABLES` and 8718 :term:`USERADD_GID_TABLES` variables. 8719 Additionally, you should also set the 8720 :term:`USERADD_ERROR_DYNAMIC` variable. 8721 8722 :term:`VOLATILE_LOG_DIR` 8723 Specifies the persistence of the target's ``/var/log`` directory, 8724 which is used to house postinstall target log files. 8725 8726 By default, :term:`VOLATILE_LOG_DIR` is set to "yes", which means the 8727 file is not persistent. You can override this setting by setting the 8728 variable to "no" to make the log directory persistent. 8729 8730 :term:`WARN_QA` 8731 Specifies the quality assurance checks whose failures are reported as 8732 warnings by the OpenEmbedded build system. You set this variable in 8733 your distribution configuration file. For a list of the checks you 8734 can control with this variable, see the 8735 ":ref:`ref-classes-insane`" section. 8736 8737 :term:`WKS_FILE` 8738 Specifies the location of the Wic kickstart file that is used by the 8739 OpenEmbedded build system to create a partitioned image 8740 (``image.wic``). For information on how to create a partitioned 8741 image, see the 8742 ":ref:`dev-manual/common-tasks:creating partitioned images using wic`" 8743 section in the Yocto Project Development Tasks Manual. For details on 8744 the kickstart file format, see the ":doc:`/ref-manual/kickstart`" Chapter. 8745 8746 :term:`WKS_FILE_DEPENDS` 8747 When placed in the recipe that builds your image, this variable lists 8748 build-time dependencies. The :term:`WKS_FILE_DEPENDS` variable is only 8749 applicable when Wic images are active (i.e. when 8750 :term:`IMAGE_FSTYPES` contains entries related 8751 to Wic). If your recipe does not create Wic images, the variable has 8752 no effect. 8753 8754 The :term:`WKS_FILE_DEPENDS` variable is similar to the 8755 :term:`DEPENDS` variable. When you use the variable in 8756 your recipe that builds the Wic image, dependencies you list in the 8757 :term:`WKS_FILE_DEPENDS` variable are added to the :term:`DEPENDS` variable. 8758 8759 With the :term:`WKS_FILE_DEPENDS` variable, you have the possibility to 8760 specify a list of additional dependencies (e.g. native tools, 8761 bootloaders, and so forth), that are required to build Wic images. 8762 Following is an example:: 8763 8764 WKS_FILE_DEPENDS = "some-native-tool" 8765 8766 In the 8767 previous example, some-native-tool would be replaced with an actual 8768 native tool on which the build would depend. 8769 8770 :term:`WKS_FILES` 8771 Specifies a list of candidate Wic kickstart files to be used by the 8772 OpenEmbedded build system to create a partitioned image. Only the 8773 first one that is found, from left to right, will be used. 8774 8775 This is only useful when there are multiple ``.wks`` files that can be 8776 used to produce an image. A typical case is when multiple layers are 8777 used for different hardware platforms, each supplying a different 8778 ``.wks`` file. In this case, you specify all possible ones through 8779 :term:`WKS_FILES`. 8780 8781 If only one ``.wks`` file is used, set :term:`WKS_FILE` instead. 8782 8783 :term:`WORKDIR` 8784 The pathname of the work directory in which the OpenEmbedded build 8785 system builds a recipe. This directory is located within the 8786 :term:`TMPDIR` directory structure and is specific to 8787 the recipe being built and the system for which it is being built. 8788 8789 The :term:`WORKDIR` directory is defined as follows:: 8790 8791 ${TMPDIR}/work/${MULTIMACH_TARGET_SYS}/${PN}/${EXTENDPE}${PV}-${PR} 8792 8793 The actual directory depends on several things: 8794 8795 - :term:`TMPDIR`: The top-level build output directory 8796 - :term:`MULTIMACH_TARGET_SYS`: The target system identifier 8797 - :term:`PN`: The recipe name 8798 - :term:`EXTENDPE`: The epoch - (if :term:`PE` is not specified, which 8799 is usually the case for most recipes, then `EXTENDPE` is blank) 8800 - :term:`PV`: The recipe version 8801 - :term:`PR`: The recipe revision 8802 8803 As an example, assume a Source Directory top-level folder name 8804 ``poky``, a default Build Directory at ``poky/build``, and a 8805 ``qemux86-poky-linux`` machine target system. Furthermore, suppose 8806 your recipe is named ``foo_1.3.0-r0.bb``. In this case, the work 8807 directory the build system uses to build the package would be as 8808 follows:: 8809 8810 poky/build/tmp/work/qemux86-poky-linux/foo/1.3.0-r0 8811 8812 :term:`XSERVER` 8813 Specifies the packages that should be installed to provide an X 8814 server and drivers for the current machine, assuming your image 8815 directly includes ``packagegroup-core-x11-xserver`` or, perhaps 8816 indirectly, includes "x11-base" in 8817 :term:`IMAGE_FEATURES`. 8818 8819 The default value of :term:`XSERVER`, if not specified in the machine 8820 configuration, is "xserver-xorg xf86-video-fbdev xf86-input-evdev". 8821 8822 :term:`XZ_THREADS` 8823 Specifies the number of parallel threads that should be used when 8824 using xz compression. 8825 8826 By default this scales with core count, but is never set less than 2 8827 to ensure that multi-threaded mode is always used so that the output 8828 file contents are deterministic. Builds will work with a value of 1 8829 but the output will differ compared to the output from the compression 8830 generated when more than one thread is used. 8831 8832 On systems where many tasks run in parallel, setting a limit to this 8833 can be helpful in controlling system resource usage. 8834 8835 :term:`XZ_MEMLIMIT` 8836 Specifies the maximum memory the xz compression should use as a percentage 8837 of system memory. If unconstrained the xz compressor can use large amounts of 8838 memory and become problematic with parallelism elsewhere in the build. 8839 "50%" has been found to be a good value. 8840 8841 :term:`ZSTD_THREADS` 8842 Specifies the number of parallel threads that should be used when 8843 using ZStandard compression. 8844 8845 By default this scales with core count, but is never set less than 2 8846 to ensure that multi-threaded mode is always used so that the output 8847 file contents are deterministic. Builds will work with a value of 1 8848 but the output will differ compared to the output from the compression 8849 generated when more than one thread is used. 8850 8851 On systems where many tasks run in parallel, setting a limit to this 8852 can be helpful in controlling system resource usage. 8853 8854