1Binman Entry Documentation 2=========================== 3 4This file describes the entry types supported by binman. These entry types can 5be placed in an image one by one to build up a final firmware image. It is 6fairly easy to create new entry types. Just add a new file to the 'etype' 7directory. You can use the existing entries as examples. 8 9Note that some entries are subclasses of others, using and extending their 10features to produce new behaviours. 11 12 13 14Entry: blob: Entry containing an arbitrary binary blob 15------------------------------------------------------ 16 17Note: This should not be used by itself. It is normally used as a parent 18class by other entry types. 19 20Properties / Entry arguments: 21 - filename: Filename of file to read into entry 22 - compress: Compression algorithm to use: 23 none: No compression 24 lz4: Use lz4 compression (via 'lz4' command-line utility) 25 26This entry reads data from a file and places it in the entry. The 27default filename is often specified specified by the subclass. See for 28example the 'u_boot' entry which provides the filename 'u-boot.bin'. 29 30If compression is enabled, an extra 'uncomp-size' property is written to 31the node (if enabled with -u) which provides the uncompressed size of the 32data. 33 34 35 36Entry: blob-dtb: A blob that holds a device tree 37------------------------------------------------ 38 39This is a blob containing a device tree. The contents of the blob are 40obtained from the list of available device-tree files, managed by the 41'state' module. 42 43 44 45Entry: blob-named-by-arg: A blob entry which gets its filename property from its subclass 46----------------------------------------------------------------------------------------- 47 48Properties / Entry arguments: 49 - <xxx>-path: Filename containing the contents of this entry (optional, 50 defaults to 0) 51 52where <xxx> is the blob_fname argument to the constructor. 53 54This entry cannot be used directly. Instead, it is used as a parent class 55for another entry, which defined blob_fname. This parameter is used to 56set the entry-arg or property containing the filename. The entry-arg or 57property is in turn used to set the actual filename. 58 59See cros_ec_rw for an example of this. 60 61 62 63Entry: cros-ec-rw: A blob entry which contains a Chromium OS read-write EC image 64-------------------------------------------------------------------------------- 65 66Properties / Entry arguments: 67 - cros-ec-rw-path: Filename containing the EC image 68 69This entry holds a Chromium OS EC (embedded controller) image, for use in 70updating the EC on startup via software sync. 71 72 73 74Entry: files: Entry containing a set of files 75--------------------------------------------- 76 77Properties / Entry arguments: 78 - pattern: Filename pattern to match the files to include 79 - compress: Compression algorithm to use: 80 none: No compression 81 lz4: Use lz4 compression (via 'lz4' command-line utility) 82 83This entry reads a number of files and places each in a separate sub-entry 84within this entry. To access these you need to enable device-tree updates 85at run-time so you can obtain the file positions. 86 87 88 89Entry: fill: An entry which is filled to a particular byte value 90---------------------------------------------------------------- 91 92Properties / Entry arguments: 93 - fill-byte: Byte to use to fill the entry 94 95Note that the size property must be set since otherwise this entry does not 96know how large it should be. 97 98You can often achieve the same effect using the pad-byte property of the 99overall image, in that the space between entries will then be padded with 100that byte. But this entry is sometimes useful for explicitly setting the 101byte value of a region. 102 103 104 105Entry: fmap: An entry which contains an Fmap section 106---------------------------------------------------- 107 108Properties / Entry arguments: 109 None 110 111FMAP is a simple format used by flashrom, an open-source utility for 112reading and writing the SPI flash, typically on x86 CPUs. The format 113provides flashrom with a list of areas, so it knows what it in the flash. 114It can then read or write just a single area, instead of the whole flash. 115 116The format is defined by the flashrom project, in the file lib/fmap.h - 117see www.flashrom.org/Flashrom for more information. 118 119When used, this entry will be populated with an FMAP which reflects the 120entries in the current image. Note that any hierarchy is squashed, since 121FMAP does not support this. 122 123 124 125Entry: gbb: An entry which contains a Chromium OS Google Binary Block 126--------------------------------------------------------------------- 127 128Properties / Entry arguments: 129 - hardware-id: Hardware ID to use for this build (a string) 130 - keydir: Directory containing the public keys to use 131 - bmpblk: Filename containing images used by recovery 132 133Chromium OS uses a GBB to store various pieces of information, in particular 134the root and recovery keys that are used to verify the boot process. Some 135more details are here: 136 137 https://www.chromium.org/chromium-os/firmware-porting-guide/2-concepts 138 139but note that the page dates from 2013 so is quite out of date. See 140README.chromium for how to obtain the required keys and tools. 141 142 143 144Entry: intel-cmc: Entry containing an Intel Chipset Micro Code (CMC) file 145------------------------------------------------------------------------- 146 147Properties / Entry arguments: 148 - filename: Filename of file to read into entry 149 150This file contains microcode for some devices in a special format. An 151example filename is 'Microcode/C0_22211.BIN'. 152 153See README.x86 for information about x86 binary blobs. 154 155 156 157Entry: intel-descriptor: Intel flash descriptor block (4KB) 158----------------------------------------------------------- 159 160Properties / Entry arguments: 161 filename: Filename of file containing the descriptor. This is typically 162 a 4KB binary file, sometimes called 'descriptor.bin' 163 164This entry is placed at the start of flash and provides information about 165the SPI flash regions. In particular it provides the base address and 166size of the ME (Management Engine) region, allowing us to place the ME 167binary in the right place. 168 169With this entry in your image, the position of the 'intel-me' entry will be 170fixed in the image, which avoids you needed to specify an offset for that 171region. This is useful, because it is not possible to change the position 172of the ME region without updating the descriptor. 173 174See README.x86 for information about x86 binary blobs. 175 176 177 178Entry: intel-fsp: Entry containing an Intel Firmware Support Package (FSP) file 179------------------------------------------------------------------------------- 180 181Properties / Entry arguments: 182 - filename: Filename of file to read into entry 183 184This file contains binary blobs which are used on some devices to make the 185platform work. U-Boot executes this code since it is not possible to set up 186the hardware using U-Boot open-source code. Documentation is typically not 187available in sufficient detail to allow this. 188 189An example filename is 'FSP/QUEENSBAY_FSP_GOLD_001_20-DECEMBER-2013.fd' 190 191See README.x86 for information about x86 binary blobs. 192 193 194 195Entry: intel-me: Entry containing an Intel Management Engine (ME) file 196---------------------------------------------------------------------- 197 198Properties / Entry arguments: 199 - filename: Filename of file to read into entry 200 201This file contains code used by the SoC that is required to make it work. 202The Management Engine is like a background task that runs things that are 203not clearly documented, but may include keyboard, deplay and network 204access. For platform that use ME it is not possible to disable it. U-Boot 205does not directly execute code in the ME binary. 206 207A typical filename is 'me.bin'. 208 209See README.x86 for information about x86 binary blobs. 210 211 212 213Entry: intel-mrc: Entry containing an Intel Memory Reference Code (MRC) file 214---------------------------------------------------------------------------- 215 216Properties / Entry arguments: 217 - filename: Filename of file to read into entry 218 219This file contains code for setting up the SDRAM on some Intel systems. This 220is executed by U-Boot when needed early during startup. A typical filename 221is 'mrc.bin'. 222 223See README.x86 for information about x86 binary blobs. 224 225 226 227Entry: intel-vbt: Entry containing an Intel Video BIOS Table (VBT) file 228----------------------------------------------------------------------- 229 230Properties / Entry arguments: 231 - filename: Filename of file to read into entry 232 233This file contains code that sets up the integrated graphics subsystem on 234some Intel SoCs. U-Boot executes this when the display is started up. 235 236See README.x86 for information about Intel binary blobs. 237 238 239 240Entry: intel-vga: Entry containing an Intel Video Graphics Adaptor (VGA) file 241----------------------------------------------------------------------------- 242 243Properties / Entry arguments: 244 - filename: Filename of file to read into entry 245 246This file contains code that sets up the integrated graphics subsystem on 247some Intel SoCs. U-Boot executes this when the display is started up. 248 249This is similar to the VBT file but in a different format. 250 251See README.x86 for information about Intel binary blobs. 252 253 254 255Entry: section: Entry that contains other entries 256------------------------------------------------- 257 258Properties / Entry arguments: (see binman README for more information) 259 - size: Size of section in bytes 260 - align-size: Align size to a particular power of two 261 - pad-before: Add padding before the entry 262 - pad-after: Add padding after the entry 263 - pad-byte: Pad byte to use when padding 264 - sort-by-offset: Reorder the entries by offset 265 - end-at-4gb: Used to build an x86 ROM which ends at 4GB (2^32) 266 - name-prefix: Adds a prefix to the name of every entry in the section 267 when writing out the map 268 269A section is an entry which can contain other entries, thus allowing 270hierarchical images to be created. See 'Sections and hierarchical images' 271in the binman README for more information. 272 273 274 275Entry: text: An entry which contains text 276----------------------------------------- 277 278The text can be provided either in the node itself or by a command-line 279argument. There is a level of indirection to allow multiple text strings 280and sharing of text. 281 282Properties / Entry arguments: 283 text-label: The value of this string indicates the property / entry-arg 284 that contains the string to place in the entry 285 <xxx> (actual name is the value of text-label): contains the string to 286 place in the entry. 287 288Example node: 289 290 text { 291 size = <50>; 292 text-label = "message"; 293 }; 294 295You can then use: 296 297 binman -amessage="this is my message" 298 299and binman will insert that string into the entry. 300 301It is also possible to put the string directly in the node: 302 303 text { 304 size = <8>; 305 text-label = "message"; 306 message = "a message directly in the node" 307 }; 308 309The text is not itself nul-terminated. This can be achieved, if required, 310by setting the size of the entry to something larger than the text. 311 312 313 314Entry: u-boot: U-Boot flat binary 315--------------------------------- 316 317Properties / Entry arguments: 318 - filename: Filename of u-boot.bin (default 'u-boot.bin') 319 320This is the U-Boot binary, containing relocation information to allow it 321to relocate itself at runtime. The binary typically includes a device tree 322blob at the end of it. Use u_boot_nodtb if you want to package the device 323tree separately. 324 325U-Boot can access binman symbols at runtime. See: 326 327 'Access to binman entry offsets at run time (fdt)' 328 329in the binman README for more information. 330 331 332 333Entry: u-boot-dtb: U-Boot device tree 334------------------------------------- 335 336Properties / Entry arguments: 337 - filename: Filename of u-boot.dtb (default 'u-boot.dtb') 338 339This is the U-Boot device tree, containing configuration information for 340U-Boot. U-Boot needs this to know what devices are present and which drivers 341to activate. 342 343Note: This is mostly an internal entry type, used by others. This allows 344binman to know which entries contain a device tree. 345 346 347 348Entry: u-boot-dtb-with-ucode: A U-Boot device tree file, with the microcode removed 349----------------------------------------------------------------------------------- 350 351Properties / Entry arguments: 352 - filename: Filename of u-boot.dtb (default 'u-boot.dtb') 353 354See Entry_u_boot_ucode for full details of the three entries involved in 355this process. This entry provides the U-Boot device-tree file, which 356contains the microcode. If the microcode is not being collated into one 357place then the offset and size of the microcode is recorded by this entry, 358for use by u_boot_with_ucode_ptr. If it is being collated, then this 359entry deletes the microcode from the device tree (to save space) and makes 360it available to u_boot_ucode. 361 362 363 364Entry: u-boot-elf: U-Boot ELF image 365----------------------------------- 366 367Properties / Entry arguments: 368 - filename: Filename of u-boot (default 'u-boot') 369 370This is the U-Boot ELF image. It does not include a device tree but can be 371relocated to any address for execution. 372 373 374 375Entry: u-boot-img: U-Boot legacy image 376-------------------------------------- 377 378Properties / Entry arguments: 379 - filename: Filename of u-boot.img (default 'u-boot.img') 380 381This is the U-Boot binary as a packaged image, in legacy format. It has a 382header which allows it to be loaded at the correct address for execution. 383 384You should use FIT (Flat Image Tree) instead of the legacy image for new 385applications. 386 387 388 389Entry: u-boot-nodtb: U-Boot flat binary without device tree appended 390-------------------------------------------------------------------- 391 392Properties / Entry arguments: 393 - filename: Filename of u-boot.bin (default 'u-boot-nodtb.bin') 394 395This is the U-Boot binary, containing relocation information to allow it 396to relocate itself at runtime. It does not include a device tree blob at 397the end of it so normally cannot work without it. You can add a u_boot_dtb 398entry after this one, or use a u_boot entry instead (which contains both 399U-Boot and the device tree). 400 401 402 403Entry: u-boot-spl: U-Boot SPL binary 404------------------------------------ 405 406Properties / Entry arguments: 407 - filename: Filename of u-boot-spl.bin (default 'spl/u-boot-spl.bin') 408 409This is the U-Boot SPL (Secondary Program Loader) binary. This is a small 410binary which loads before U-Boot proper, typically into on-chip SRAM. It is 411responsible for locating, loading and jumping to U-Boot. Note that SPL is 412not relocatable so must be loaded to the correct address in SRAM, or written 413to run from the correct address if direct flash execution is possible (e.g. 414on x86 devices). 415 416SPL can access binman symbols at runtime. See: 417 418 'Access to binman entry offsets at run time (symbols)' 419 420in the binman README for more information. 421 422The ELF file 'spl/u-boot-spl' must also be available for this to work, since 423binman uses that to look up symbols to write into the SPL binary. 424 425 426 427Entry: u-boot-spl-bss-pad: U-Boot SPL binary padded with a BSS region 428--------------------------------------------------------------------- 429 430Properties / Entry arguments: 431 None 432 433This is similar to u_boot_spl except that padding is added after the SPL 434binary to cover the BSS (Block Started by Symbol) region. This region holds 435the various used by SPL. It is set to 0 by SPL when it starts up. If you 436want to append data to the SPL image (such as a device tree file), you must 437pad out the BSS region to avoid the data overlapping with U-Boot variables. 438This entry is useful in that case. It automatically pads out the entry size 439to cover both the code, data and BSS. 440 441The ELF file 'spl/u-boot-spl' must also be available for this to work, since 442binman uses that to look up the BSS address. 443 444 445 446Entry: u-boot-spl-dtb: U-Boot SPL device tree 447--------------------------------------------- 448 449Properties / Entry arguments: 450 - filename: Filename of u-boot.dtb (default 'spl/u-boot-spl.dtb') 451 452This is the SPL device tree, containing configuration information for 453SPL. SPL needs this to know what devices are present and which drivers 454to activate. 455 456 457 458Entry: u-boot-spl-elf: U-Boot SPL ELF image 459------------------------------------------- 460 461Properties / Entry arguments: 462 - filename: Filename of SPL u-boot (default 'spl/u-boot') 463 464This is the U-Boot SPL ELF image. It does not include a device tree but can 465be relocated to any address for execution. 466 467 468 469Entry: u-boot-spl-nodtb: SPL binary without device tree appended 470---------------------------------------------------------------- 471 472Properties / Entry arguments: 473 - filename: Filename of spl/u-boot-spl-nodtb.bin (default 474 'spl/u-boot-spl-nodtb.bin') 475 476This is the U-Boot SPL binary, It does not include a device tree blob at 477the end of it so may not be able to work without it, assuming SPL needs 478a device tree to operation on your platform. You can add a u_boot_spl_dtb 479entry after this one, or use a u_boot_spl entry instead (which contains 480both SPL and the device tree). 481 482 483 484Entry: u-boot-spl-with-ucode-ptr: U-Boot SPL with embedded microcode pointer 485---------------------------------------------------------------------------- 486 487This is used when SPL must set up the microcode for U-Boot. 488 489See Entry_u_boot_ucode for full details of the entries involved in this 490process. 491 492 493 494Entry: u-boot-tpl: U-Boot TPL binary 495------------------------------------ 496 497Properties / Entry arguments: 498 - filename: Filename of u-boot-tpl.bin (default 'tpl/u-boot-tpl.bin') 499 500This is the U-Boot TPL (Tertiary Program Loader) binary. This is a small 501binary which loads before SPL, typically into on-chip SRAM. It is 502responsible for locating, loading and jumping to SPL, the next-stage 503loader. Note that SPL is not relocatable so must be loaded to the correct 504address in SRAM, or written to run from the correct address if direct 505flash execution is possible (e.g. on x86 devices). 506 507SPL can access binman symbols at runtime. See: 508 509 'Access to binman entry offsets at run time (symbols)' 510 511in the binman README for more information. 512 513The ELF file 'tpl/u-boot-tpl' must also be available for this to work, since 514binman uses that to look up symbols to write into the TPL binary. 515 516 517 518Entry: u-boot-tpl-dtb: U-Boot TPL device tree 519--------------------------------------------- 520 521Properties / Entry arguments: 522 - filename: Filename of u-boot.dtb (default 'tpl/u-boot-tpl.dtb') 523 524This is the TPL device tree, containing configuration information for 525TPL. TPL needs this to know what devices are present and which drivers 526to activate. 527 528 529 530Entry: u-boot-tpl-dtb-with-ucode: U-Boot TPL with embedded microcode pointer 531---------------------------------------------------------------------------- 532 533This is used when TPL must set up the microcode for U-Boot. 534 535See Entry_u_boot_ucode for full details of the entries involved in this 536process. 537 538 539 540Entry: u-boot-tpl-with-ucode-ptr: U-Boot TPL with embedded microcode pointer 541---------------------------------------------------------------------------- 542 543See Entry_u_boot_ucode for full details of the entries involved in this 544process. 545 546 547 548Entry: u-boot-ucode: U-Boot microcode block 549------------------------------------------- 550 551Properties / Entry arguments: 552 None 553 554The contents of this entry are filled in automatically by other entries 555which must also be in the image. 556 557U-Boot on x86 needs a single block of microcode. This is collected from 558the various microcode update nodes in the device tree. It is also unable 559to read the microcode from the device tree on platforms that use FSP 560(Firmware Support Package) binaries, because the API requires that the 561microcode is supplied before there is any SRAM available to use (i.e. 562the FSP sets up the SRAM / cache-as-RAM but does so in the call that 563requires the microcode!). To keep things simple, all x86 platforms handle 564microcode the same way in U-Boot (even non-FSP platforms). This is that 565a table is placed at _dt_ucode_base_size containing the base address and 566size of the microcode. This is either passed to the FSP (for FSP 567platforms), or used to set up the microcode (for non-FSP platforms). 568This all happens in the build system since it is the only way to get 569the microcode into a single blob and accessible without SRAM. 570 571There are two cases to handle. If there is only one microcode blob in 572the device tree, then the ucode pointer it set to point to that. This 573entry (u-boot-ucode) is empty. If there is more than one update, then 574this entry holds the concatenation of all updates, and the device tree 575entry (u-boot-dtb-with-ucode) is updated to remove the microcode. This 576last step ensures that that the microcode appears in one contiguous 577block in the image and is not unnecessarily duplicated in the device 578tree. It is referred to as 'collation' here. 579 580Entry types that have a part to play in handling microcode: 581 582 Entry_u_boot_with_ucode_ptr: 583 Contains u-boot-nodtb.bin (i.e. U-Boot without the device tree). 584 It updates it with the address and size of the microcode so that 585 U-Boot can find it early on start-up. 586 Entry_u_boot_dtb_with_ucode: 587 Contains u-boot.dtb. It stores the microcode in a 588 'self.ucode_data' property, which is then read by this class to 589 obtain the microcode if needed. If collation is performed, it 590 removes the microcode from the device tree. 591 Entry_u_boot_ucode: 592 This class. If collation is enabled it reads the microcode from 593 the Entry_u_boot_dtb_with_ucode entry, and uses it as the 594 contents of this entry. 595 596 597 598Entry: u-boot-with-ucode-ptr: U-Boot with embedded microcode pointer 599-------------------------------------------------------------------- 600 601Properties / Entry arguments: 602 - filename: Filename of u-boot-nodtb.dtb (default 'u-boot-nodtb.dtb') 603 - optional-ucode: boolean property to make microcode optional. If the 604 u-boot.bin image does not include microcode, no error will 605 be generated. 606 607See Entry_u_boot_ucode for full details of the three entries involved in 608this process. This entry updates U-Boot with the offset and size of the 609microcode, to allow early x86 boot code to find it without doing anything 610complicated. Otherwise it is the same as the u_boot entry. 611 612 613 614Entry: vblock: An entry which contains a Chromium OS verified boot block 615------------------------------------------------------------------------ 616 617Properties / Entry arguments: 618 - keydir: Directory containing the public keys to use 619 - keyblock: Name of the key file to use (inside keydir) 620 - signprivate: Name of provide key file to use (inside keydir) 621 - version: Version number of the vblock (typically 1) 622 - kernelkey: Name of the kernel key to use (inside keydir) 623 - preamble-flags: Value of the vboot preamble flags (typically 0) 624 625Output files: 626 - input.<unique_name> - input file passed to futility 627 - vblock.<unique_name> - output file generated by futility (which is 628 used as the entry contents) 629 630Chromium OS signs the read-write firmware and kernel, writing the signature 631in this block. This allows U-Boot to verify that the next firmware stage 632and kernel are genuine. 633 634 635 636Entry: x86-start16: x86 16-bit start-up code for U-Boot 637------------------------------------------------------- 638 639Properties / Entry arguments: 640 - filename: Filename of u-boot-x86-16bit.bin (default 641 'u-boot-x86-16bit.bin') 642 643x86 CPUs start up in 16-bit mode, even if they are 32-bit CPUs. This code 644must be placed at a particular address. This entry holds that code. It is 645typically placed at offset CONFIG_SYS_X86_START16. The code is responsible 646for changing to 32-bit mode and jumping to U-Boot's entry point, which 647requires 32-bit mode (for 32-bit U-Boot). 648 649For 64-bit U-Boot, the 'x86_start16_spl' entry type is used instead. 650 651 652 653Entry: x86-start16-spl: x86 16-bit start-up code for SPL 654-------------------------------------------------------- 655 656Properties / Entry arguments: 657 - filename: Filename of spl/u-boot-x86-16bit-spl.bin (default 658 'spl/u-boot-x86-16bit-spl.bin') 659 660x86 CPUs start up in 16-bit mode, even if they are 64-bit CPUs. This code 661must be placed at a particular address. This entry holds that code. It is 662typically placed at offset CONFIG_SYS_X86_START16. The code is responsible 663for changing to 32-bit mode and starting SPL, which in turn changes to 66464-bit mode and jumps to U-Boot (for 64-bit U-Boot). 665 666For 32-bit U-Boot, the 'x86_start16' entry type is used instead. 667 668 669 670Entry: x86-start16-tpl: x86 16-bit start-up code for TPL 671-------------------------------------------------------- 672 673Properties / Entry arguments: 674 - filename: Filename of tpl/u-boot-x86-16bit-tpl.bin (default 675 'tpl/u-boot-x86-16bit-tpl.bin') 676 677x86 CPUs start up in 16-bit mode, even if they are 64-bit CPUs. This code 678must be placed at a particular address. This entry holds that code. It is 679typically placed at offset CONFIG_SYS_X86_START16. The code is responsible 680for changing to 32-bit mode and starting TPL, which in turn jumps to SPL. 681 682If TPL is not being used, the 'x86_start16_spl or 'x86_start16' entry types 683may be used instead. 684 685 686 687