1# 2# (C) Copyright 2000 - 2013 3# Wolfgang Denk, DENX Software Engineering, wd@denx.de. 4# 5# SPDX-License-Identifier: GPL-2.0+ 6# 7 8Summary: 9======== 10 11This directory contains the source code for U-Boot, a boot loader for 12Embedded boards based on PowerPC, ARM, MIPS and several other 13processors, which can be installed in a boot ROM and used to 14initialize and test the hardware or to download and run application 15code. 16 17The development of U-Boot is closely related to Linux: some parts of 18the source code originate in the Linux source tree, we have some 19header files in common, and special provision has been made to 20support booting of Linux images. 21 22Some attention has been paid to make this software easily 23configurable and extendable. For instance, all monitor commands are 24implemented with the same call interface, so that it's very easy to 25add new commands. Also, instead of permanently adding rarely used 26code (for instance hardware test utilities) to the monitor, you can 27load and run it dynamically. 28 29 30Status: 31======= 32 33In general, all boards for which a configuration option exists in the 34Makefile have been tested to some extent and can be considered 35"working". In fact, many of them are used in production systems. 36 37In case of problems see the CHANGELOG file to find out who contributed 38the specific port. In addition, there are various MAINTAINERS files 39scattered throughout the U-Boot source identifying the people or 40companies responsible for various boards and subsystems. 41 42Note: As of August, 2010, there is no longer a CHANGELOG file in the 43actual U-Boot source tree; however, it can be created dynamically 44from the Git log using: 45 46 make CHANGELOG 47 48 49Where to get help: 50================== 51 52In case you have questions about, problems with or contributions for 53U-Boot, you should send a message to the U-Boot mailing list at 54<u-boot@lists.denx.de>. There is also an archive of previous traffic 55on the mailing list - please search the archive before asking FAQ's. 56Please see http://lists.denx.de/pipermail/u-boot and 57http://dir.gmane.org/gmane.comp.boot-loaders.u-boot 58 59 60Where to get source code: 61========================= 62 63The U-Boot source code is maintained in the Git repository at 64git://www.denx.de/git/u-boot.git ; you can browse it online at 65http://www.denx.de/cgi-bin/gitweb.cgi?p=u-boot.git;a=summary 66 67The "snapshot" links on this page allow you to download tarballs of 68any version you might be interested in. Official releases are also 69available for FTP download from the ftp://ftp.denx.de/pub/u-boot/ 70directory. 71 72Pre-built (and tested) images are available from 73ftp://ftp.denx.de/pub/u-boot/images/ 74 75 76Where we come from: 77=================== 78 79- start from 8xxrom sources 80- create PPCBoot project (http://sourceforge.net/projects/ppcboot) 81- clean up code 82- make it easier to add custom boards 83- make it possible to add other [PowerPC] CPUs 84- extend functions, especially: 85 * Provide extended interface to Linux boot loader 86 * S-Record download 87 * network boot 88 * PCMCIA / CompactFlash / ATA disk / SCSI ... boot 89- create ARMBoot project (http://sourceforge.net/projects/armboot) 90- add other CPU families (starting with ARM) 91- create U-Boot project (http://sourceforge.net/projects/u-boot) 92- current project page: see http://www.denx.de/wiki/U-Boot 93 94 95Names and Spelling: 96=================== 97 98The "official" name of this project is "Das U-Boot". The spelling 99"U-Boot" shall be used in all written text (documentation, comments 100in source files etc.). Example: 101 102 This is the README file for the U-Boot project. 103 104File names etc. shall be based on the string "u-boot". Examples: 105 106 include/asm-ppc/u-boot.h 107 108 #include <asm/u-boot.h> 109 110Variable names, preprocessor constants etc. shall be either based on 111the string "u_boot" or on "U_BOOT". Example: 112 113 U_BOOT_VERSION u_boot_logo 114 IH_OS_U_BOOT u_boot_hush_start 115 116 117Versioning: 118=========== 119 120Starting with the release in October 2008, the names of the releases 121were changed from numerical release numbers without deeper meaning 122into a time stamp based numbering. Regular releases are identified by 123names consisting of the calendar year and month of the release date. 124Additional fields (if present) indicate release candidates or bug fix 125releases in "stable" maintenance trees. 126 127Examples: 128 U-Boot v2009.11 - Release November 2009 129 U-Boot v2009.11.1 - Release 1 in version November 2009 stable tree 130 U-Boot v2010.09-rc1 - Release candidate 1 for September 2010 release 131 132 133Directory Hierarchy: 134==================== 135 136/arch Architecture specific files 137 /arc Files generic to ARC architecture 138 /arm Files generic to ARM architecture 139 /m68k Files generic to m68k architecture 140 /microblaze Files generic to microblaze architecture 141 /mips Files generic to MIPS architecture 142 /nds32 Files generic to NDS32 architecture 143 /nios2 Files generic to Altera NIOS2 architecture 144 /openrisc Files generic to OpenRISC architecture 145 /powerpc Files generic to PowerPC architecture 146 /sandbox Files generic to HW-independent "sandbox" 147 /sh Files generic to SH architecture 148 /x86 Files generic to x86 architecture 149/api Machine/arch independent API for external apps 150/board Board dependent files 151/cmd U-Boot commands functions 152/common Misc architecture independent functions 153/configs Board default configuration files 154/disk Code for disk drive partition handling 155/doc Documentation (don't expect too much) 156/drivers Commonly used device drivers 157/dts Contains Makefile for building internal U-Boot fdt. 158/examples Example code for standalone applications, etc. 159/fs Filesystem code (cramfs, ext2, jffs2, etc.) 160/include Header Files 161/lib Library routines generic to all architectures 162/Licenses Various license files 163/net Networking code 164/post Power On Self Test 165/scripts Various build scripts and Makefiles 166/test Various unit test files 167/tools Tools to build S-Record or U-Boot images, etc. 168 169Software Configuration: 170======================= 171 172Configuration is usually done using C preprocessor defines; the 173rationale behind that is to avoid dead code whenever possible. 174 175There are two classes of configuration variables: 176 177* Configuration _OPTIONS_: 178 These are selectable by the user and have names beginning with 179 "CONFIG_". 180 181* Configuration _SETTINGS_: 182 These depend on the hardware etc. and should not be meddled with if 183 you don't know what you're doing; they have names beginning with 184 "CONFIG_SYS_". 185 186Previously, all configuration was done by hand, which involved creating 187symbolic links and editing configuration files manually. More recently, 188U-Boot has added the Kbuild infrastructure used by the Linux kernel, 189allowing you to use the "make menuconfig" command to configure your 190build. 191 192 193Selection of Processor Architecture and Board Type: 194--------------------------------------------------- 195 196For all supported boards there are ready-to-use default 197configurations available; just type "make <board_name>_defconfig". 198 199Example: For a TQM823L module type: 200 201 cd u-boot 202 make TQM823L_defconfig 203 204Note: If you're looking for the default configuration file for a board 205you're sure used to be there but is now missing, check the file 206doc/README.scrapyard for a list of no longer supported boards. 207 208Sandbox Environment: 209-------------------- 210 211U-Boot can be built natively to run on a Linux host using the 'sandbox' 212board. This allows feature development which is not board- or architecture- 213specific to be undertaken on a native platform. The sandbox is also used to 214run some of U-Boot's tests. 215 216See board/sandbox/README.sandbox for more details. 217 218 219Board Initialisation Flow: 220-------------------------- 221 222This is the intended start-up flow for boards. This should apply for both 223SPL and U-Boot proper (i.e. they both follow the same rules). 224 225Note: "SPL" stands for "Secondary Program Loader," which is explained in 226more detail later in this file. 227 228At present, SPL mostly uses a separate code path, but the function names 229and roles of each function are the same. Some boards or architectures 230may not conform to this. At least most ARM boards which use 231CONFIG_SPL_FRAMEWORK conform to this. 232 233Execution typically starts with an architecture-specific (and possibly 234CPU-specific) start.S file, such as: 235 236 - arch/arm/cpu/armv7/start.S 237 - arch/powerpc/cpu/mpc83xx/start.S 238 - arch/mips/cpu/start.S 239 240and so on. From there, three functions are called; the purpose and 241limitations of each of these functions are described below. 242 243lowlevel_init(): 244 - purpose: essential init to permit execution to reach board_init_f() 245 - no global_data or BSS 246 - there is no stack (ARMv7 may have one but it will soon be removed) 247 - must not set up SDRAM or use console 248 - must only do the bare minimum to allow execution to continue to 249 board_init_f() 250 - this is almost never needed 251 - return normally from this function 252 253board_init_f(): 254 - purpose: set up the machine ready for running board_init_r(): 255 i.e. SDRAM and serial UART 256 - global_data is available 257 - stack is in SRAM 258 - BSS is not available, so you cannot use global/static variables, 259 only stack variables and global_data 260 261 Non-SPL-specific notes: 262 - dram_init() is called to set up DRAM. If already done in SPL this 263 can do nothing 264 265 SPL-specific notes: 266 - you can override the entire board_init_f() function with your own 267 version as needed. 268 - preloader_console_init() can be called here in extremis 269 - should set up SDRAM, and anything needed to make the UART work 270 - these is no need to clear BSS, it will be done by crt0.S 271 - must return normally from this function (don't call board_init_r() 272 directly) 273 274Here the BSS is cleared. For SPL, if CONFIG_SPL_STACK_R is defined, then at 275this point the stack and global_data are relocated to below 276CONFIG_SPL_STACK_R_ADDR. For non-SPL, U-Boot is relocated to run at the top of 277memory. 278 279board_init_r(): 280 - purpose: main execution, common code 281 - global_data is available 282 - SDRAM is available 283 - BSS is available, all static/global variables can be used 284 - execution eventually continues to main_loop() 285 286 Non-SPL-specific notes: 287 - U-Boot is relocated to the top of memory and is now running from 288 there. 289 290 SPL-specific notes: 291 - stack is optionally in SDRAM, if CONFIG_SPL_STACK_R is defined and 292 CONFIG_SPL_STACK_R_ADDR points into SDRAM 293 - preloader_console_init() can be called here - typically this is 294 done by selecting CONFIG_SPL_BOARD_INIT and then supplying a 295 spl_board_init() function containing this call 296 - loads U-Boot or (in falcon mode) Linux 297 298 299 300Configuration Options: 301---------------------- 302 303Configuration depends on the combination of board and CPU type; all 304such information is kept in a configuration file 305"include/configs/<board_name>.h". 306 307Example: For a TQM823L module, all configuration settings are in 308"include/configs/TQM823L.h". 309 310 311Many of the options are named exactly as the corresponding Linux 312kernel configuration options. The intention is to make it easier to 313build a config tool - later. 314 315 316The following options need to be configured: 317 318- CPU Type: Define exactly one, e.g. CONFIG_MPC85XX. 319 320- Board Type: Define exactly one, e.g. CONFIG_MPC8540ADS. 321 322- Marvell Family Member 323 CONFIG_SYS_MVFS - define it if you want to enable 324 multiple fs option at one time 325 for marvell soc family 326 327- 85xx CPU Options: 328 CONFIG_SYS_PPC64 329 330 Specifies that the core is a 64-bit PowerPC implementation (implements 331 the "64" category of the Power ISA). This is necessary for ePAPR 332 compliance, among other possible reasons. 333 334 CONFIG_SYS_FSL_TBCLK_DIV 335 336 Defines the core time base clock divider ratio compared to the 337 system clock. On most PQ3 devices this is 8, on newer QorIQ 338 devices it can be 16 or 32. The ratio varies from SoC to Soc. 339 340 CONFIG_SYS_FSL_PCIE_COMPAT 341 342 Defines the string to utilize when trying to match PCIe device 343 tree nodes for the given platform. 344 345 CONFIG_SYS_FSL_ERRATUM_A004510 346 347 Enables a workaround for erratum A004510. If set, 348 then CONFIG_SYS_FSL_ERRATUM_A004510_SVR_REV and 349 CONFIG_SYS_FSL_CORENET_SNOOPVEC_COREONLY must be set. 350 351 CONFIG_SYS_FSL_ERRATUM_A004510_SVR_REV 352 CONFIG_SYS_FSL_ERRATUM_A004510_SVR_REV2 (optional) 353 354 Defines one or two SoC revisions (low 8 bits of SVR) 355 for which the A004510 workaround should be applied. 356 357 The rest of SVR is either not relevant to the decision 358 of whether the erratum is present (e.g. p2040 versus 359 p2041) or is implied by the build target, which controls 360 whether CONFIG_SYS_FSL_ERRATUM_A004510 is set. 361 362 See Freescale App Note 4493 for more information about 363 this erratum. 364 365 CONFIG_A003399_NOR_WORKAROUND 366 Enables a workaround for IFC erratum A003399. It is only 367 required during NOR boot. 368 369 CONFIG_A008044_WORKAROUND 370 Enables a workaround for T1040/T1042 erratum A008044. It is only 371 required during NAND boot and valid for Rev 1.0 SoC revision 372 373 CONFIG_SYS_FSL_CORENET_SNOOPVEC_COREONLY 374 375 This is the value to write into CCSR offset 0x18600 376 according to the A004510 workaround. 377 378 CONFIG_SYS_FSL_DSP_DDR_ADDR 379 This value denotes start offset of DDR memory which is 380 connected exclusively to the DSP cores. 381 382 CONFIG_SYS_FSL_DSP_M2_RAM_ADDR 383 This value denotes start offset of M2 memory 384 which is directly connected to the DSP core. 385 386 CONFIG_SYS_FSL_DSP_M3_RAM_ADDR 387 This value denotes start offset of M3 memory which is directly 388 connected to the DSP core. 389 390 CONFIG_SYS_FSL_DSP_CCSRBAR_DEFAULT 391 This value denotes start offset of DSP CCSR space. 392 393 CONFIG_SYS_FSL_SINGLE_SOURCE_CLK 394 Single Source Clock is clocking mode present in some of FSL SoC's. 395 In this mode, a single differential clock is used to supply 396 clocks to the sysclock, ddrclock and usbclock. 397 398 CONFIG_SYS_CPC_REINIT_F 399 This CONFIG is defined when the CPC is configured as SRAM at the 400 time of U-Boot entry and is required to be re-initialized. 401 402 CONFIG_DEEP_SLEEP 403 Indicates this SoC supports deep sleep feature. If deep sleep is 404 supported, core will start to execute uboot when wakes up. 405 406- Generic CPU options: 407 CONFIG_SYS_GENERIC_GLOBAL_DATA 408 Defines global data is initialized in generic board board_init_f(). 409 If this macro is defined, global data is created and cleared in 410 generic board board_init_f(). Without this macro, architecture/board 411 should initialize global data before calling board_init_f(). 412 413 CONFIG_SYS_BIG_ENDIAN, CONFIG_SYS_LITTLE_ENDIAN 414 415 Defines the endianess of the CPU. Implementation of those 416 values is arch specific. 417 418 CONFIG_SYS_FSL_DDR 419 Freescale DDR driver in use. This type of DDR controller is 420 found in mpc83xx, mpc85xx, mpc86xx as well as some ARM core 421 SoCs. 422 423 CONFIG_SYS_FSL_DDR_ADDR 424 Freescale DDR memory-mapped register base. 425 426 CONFIG_SYS_FSL_DDR_EMU 427 Specify emulator support for DDR. Some DDR features such as 428 deskew training are not available. 429 430 CONFIG_SYS_FSL_DDRC_GEN1 431 Freescale DDR1 controller. 432 433 CONFIG_SYS_FSL_DDRC_GEN2 434 Freescale DDR2 controller. 435 436 CONFIG_SYS_FSL_DDRC_GEN3 437 Freescale DDR3 controller. 438 439 CONFIG_SYS_FSL_DDRC_GEN4 440 Freescale DDR4 controller. 441 442 CONFIG_SYS_FSL_DDRC_ARM_GEN3 443 Freescale DDR3 controller for ARM-based SoCs. 444 445 CONFIG_SYS_FSL_DDR1 446 Board config to use DDR1. It can be enabled for SoCs with 447 Freescale DDR1 or DDR2 controllers, depending on the board 448 implemetation. 449 450 CONFIG_SYS_FSL_DDR2 451 Board config to use DDR2. It can be enabled for SoCs with 452 Freescale DDR2 or DDR3 controllers, depending on the board 453 implementation. 454 455 CONFIG_SYS_FSL_DDR3 456 Board config to use DDR3. It can be enabled for SoCs with 457 Freescale DDR3 or DDR3L controllers. 458 459 CONFIG_SYS_FSL_DDR3L 460 Board config to use DDR3L. It can be enabled for SoCs with 461 DDR3L controllers. 462 463 CONFIG_SYS_FSL_DDR4 464 Board config to use DDR4. It can be enabled for SoCs with 465 DDR4 controllers. 466 467 CONFIG_SYS_FSL_IFC_BE 468 Defines the IFC controller register space as Big Endian 469 470 CONFIG_SYS_FSL_IFC_LE 471 Defines the IFC controller register space as Little Endian 472 473 CONFIG_SYS_FSL_IFC_CLK_DIV 474 Defines divider of platform clock(clock input to IFC controller). 475 476 CONFIG_SYS_FSL_LBC_CLK_DIV 477 Defines divider of platform clock(clock input to eLBC controller). 478 479 CONFIG_SYS_FSL_PBL_PBI 480 It enables addition of RCW (Power on reset configuration) in built image. 481 Please refer doc/README.pblimage for more details 482 483 CONFIG_SYS_FSL_PBL_RCW 484 It adds PBI(pre-boot instructions) commands in u-boot build image. 485 PBI commands can be used to configure SoC before it starts the execution. 486 Please refer doc/README.pblimage for more details 487 488 CONFIG_SPL_FSL_PBL 489 It adds a target to create boot binary having SPL binary in PBI format 490 concatenated with u-boot binary. 491 492 CONFIG_SYS_FSL_DDR_BE 493 Defines the DDR controller register space as Big Endian 494 495 CONFIG_SYS_FSL_DDR_LE 496 Defines the DDR controller register space as Little Endian 497 498 CONFIG_SYS_FSL_DDR_SDRAM_BASE_PHY 499 Physical address from the view of DDR controllers. It is the 500 same as CONFIG_SYS_DDR_SDRAM_BASE for all Power SoCs. But 501 it could be different for ARM SoCs. 502 503 CONFIG_SYS_FSL_DDR_INTLV_256B 504 DDR controller interleaving on 256-byte. This is a special 505 interleaving mode, handled by Dickens for Freescale layerscape 506 SoCs with ARM core. 507 508 CONFIG_SYS_FSL_DDR_MAIN_NUM_CTRLS 509 Number of controllers used as main memory. 510 511 CONFIG_SYS_FSL_OTHER_DDR_NUM_CTRLS 512 Number of controllers used for other than main memory. 513 514 CONFIG_SYS_FSL_HAS_DP_DDR 515 Defines the SoC has DP-DDR used for DPAA. 516 517 CONFIG_SYS_FSL_SEC_BE 518 Defines the SEC controller register space as Big Endian 519 520 CONFIG_SYS_FSL_SEC_LE 521 Defines the SEC controller register space as Little Endian 522 523- MIPS CPU options: 524 CONFIG_SYS_INIT_SP_OFFSET 525 526 Offset relative to CONFIG_SYS_SDRAM_BASE for initial stack 527 pointer. This is needed for the temporary stack before 528 relocation. 529 530 CONFIG_SYS_MIPS_CACHE_MODE 531 532 Cache operation mode for the MIPS CPU. 533 See also arch/mips/include/asm/mipsregs.h. 534 Possible values are: 535 CONF_CM_CACHABLE_NO_WA 536 CONF_CM_CACHABLE_WA 537 CONF_CM_UNCACHED 538 CONF_CM_CACHABLE_NONCOHERENT 539 CONF_CM_CACHABLE_CE 540 CONF_CM_CACHABLE_COW 541 CONF_CM_CACHABLE_CUW 542 CONF_CM_CACHABLE_ACCELERATED 543 544 CONFIG_SYS_XWAY_EBU_BOOTCFG 545 546 Special option for Lantiq XWAY SoCs for booting from NOR flash. 547 See also arch/mips/cpu/mips32/start.S. 548 549 CONFIG_XWAY_SWAP_BYTES 550 551 Enable compilation of tools/xway-swap-bytes needed for Lantiq 552 XWAY SoCs for booting from NOR flash. The U-Boot image needs to 553 be swapped if a flash programmer is used. 554 555- ARM options: 556 CONFIG_SYS_EXCEPTION_VECTORS_HIGH 557 558 Select high exception vectors of the ARM core, e.g., do not 559 clear the V bit of the c1 register of CP15. 560 561 COUNTER_FREQUENCY 562 Generic timer clock source frequency. 563 564 COUNTER_FREQUENCY_REAL 565 Generic timer clock source frequency if the real clock is 566 different from COUNTER_FREQUENCY, and can only be determined 567 at run time. 568 569- Tegra SoC options: 570 CONFIG_TEGRA_SUPPORT_NON_SECURE 571 572 Support executing U-Boot in non-secure (NS) mode. Certain 573 impossible actions will be skipped if the CPU is in NS mode, 574 such as ARM architectural timer initialization. 575 576- Linux Kernel Interface: 577 CONFIG_CLOCKS_IN_MHZ 578 579 U-Boot stores all clock information in Hz 580 internally. For binary compatibility with older Linux 581 kernels (which expect the clocks passed in the 582 bd_info data to be in MHz) the environment variable 583 "clocks_in_mhz" can be defined so that U-Boot 584 converts clock data to MHZ before passing it to the 585 Linux kernel. 586 When CONFIG_CLOCKS_IN_MHZ is defined, a definition of 587 "clocks_in_mhz=1" is automatically included in the 588 default environment. 589 590 CONFIG_MEMSIZE_IN_BYTES [relevant for MIPS only] 591 592 When transferring memsize parameter to Linux, some versions 593 expect it to be in bytes, others in MB. 594 Define CONFIG_MEMSIZE_IN_BYTES to make it in bytes. 595 596 CONFIG_OF_LIBFDT 597 598 New kernel versions are expecting firmware settings to be 599 passed using flattened device trees (based on open firmware 600 concepts). 601 602 CONFIG_OF_LIBFDT 603 * New libfdt-based support 604 * Adds the "fdt" command 605 * The bootm command automatically updates the fdt 606 607 OF_TBCLK - The timebase frequency. 608 OF_STDOUT_PATH - The path to the console device 609 610 boards with QUICC Engines require OF_QE to set UCC MAC 611 addresses 612 613 CONFIG_OF_BOARD_SETUP 614 615 Board code has addition modification that it wants to make 616 to the flat device tree before handing it off to the kernel 617 618 CONFIG_OF_SYSTEM_SETUP 619 620 Other code has addition modification that it wants to make 621 to the flat device tree before handing it off to the kernel. 622 This causes ft_system_setup() to be called before booting 623 the kernel. 624 625 CONFIG_OF_IDE_FIXUP 626 627 U-Boot can detect if an IDE device is present or not. 628 If not, and this new config option is activated, U-Boot 629 removes the ATA node from the DTS before booting Linux, 630 so the Linux IDE driver does not probe the device and 631 crash. This is needed for buggy hardware (uc101) where 632 no pull down resistor is connected to the signal IDE5V_DD7. 633 634 CONFIG_MACH_TYPE [relevant for ARM only][mandatory] 635 636 This setting is mandatory for all boards that have only one 637 machine type and must be used to specify the machine type 638 number as it appears in the ARM machine registry 639 (see http://www.arm.linux.org.uk/developer/machines/). 640 Only boards that have multiple machine types supported 641 in a single configuration file and the machine type is 642 runtime discoverable, do not have to use this setting. 643 644- vxWorks boot parameters: 645 646 bootvx constructs a valid bootline using the following 647 environments variables: bootdev, bootfile, ipaddr, netmask, 648 serverip, gatewayip, hostname, othbootargs. 649 It loads the vxWorks image pointed bootfile. 650 651 Note: If a "bootargs" environment is defined, it will overwride 652 the defaults discussed just above. 653 654- Cache Configuration: 655 CONFIG_SYS_ICACHE_OFF - Do not enable instruction cache in U-Boot 656 CONFIG_SYS_DCACHE_OFF - Do not enable data cache in U-Boot 657 CONFIG_SYS_L2CACHE_OFF- Do not enable L2 cache in U-Boot 658 659- Cache Configuration for ARM: 660 CONFIG_SYS_L2_PL310 - Enable support for ARM PL310 L2 cache 661 controller 662 CONFIG_SYS_PL310_BASE - Physical base address of PL310 663 controller register space 664 665- Serial Ports: 666 CONFIG_PL010_SERIAL 667 668 Define this if you want support for Amba PrimeCell PL010 UARTs. 669 670 CONFIG_PL011_SERIAL 671 672 Define this if you want support for Amba PrimeCell PL011 UARTs. 673 674 CONFIG_PL011_CLOCK 675 676 If you have Amba PrimeCell PL011 UARTs, set this variable to 677 the clock speed of the UARTs. 678 679 CONFIG_PL01x_PORTS 680 681 If you have Amba PrimeCell PL010 or PL011 UARTs on your board, 682 define this to a list of base addresses for each (supported) 683 port. See e.g. include/configs/versatile.h 684 685 CONFIG_SERIAL_HW_FLOW_CONTROL 686 687 Define this variable to enable hw flow control in serial driver. 688 Current user of this option is drivers/serial/nsl16550.c driver 689 690- Console Baudrate: 691 CONFIG_BAUDRATE - in bps 692 Select one of the baudrates listed in 693 CONFIG_SYS_BAUDRATE_TABLE, see below. 694 695- Autoboot Command: 696 CONFIG_BOOTCOMMAND 697 Only needed when CONFIG_BOOTDELAY is enabled; 698 define a command string that is automatically executed 699 when no character is read on the console interface 700 within "Boot Delay" after reset. 701 702 CONFIG_BOOTARGS 703 This can be used to pass arguments to the bootm 704 command. The value of CONFIG_BOOTARGS goes into the 705 environment value "bootargs". 706 707 CONFIG_RAMBOOT and CONFIG_NFSBOOT 708 The value of these goes into the environment as 709 "ramboot" and "nfsboot" respectively, and can be used 710 as a convenience, when switching between booting from 711 RAM and NFS. 712 713- Bootcount: 714 CONFIG_BOOTCOUNT_LIMIT 715 Implements a mechanism for detecting a repeating reboot 716 cycle, see: 717 http://www.denx.de/wiki/view/DULG/UBootBootCountLimit 718 719 CONFIG_BOOTCOUNT_ENV 720 If no softreset save registers are found on the hardware 721 "bootcount" is stored in the environment. To prevent a 722 saveenv on all reboots, the environment variable 723 "upgrade_available" is used. If "upgrade_available" is 724 0, "bootcount" is always 0, if "upgrade_available" is 725 1 "bootcount" is incremented in the environment. 726 So the Userspace Applikation must set the "upgrade_available" 727 and "bootcount" variable to 0, if a boot was successfully. 728 729- Pre-Boot Commands: 730 CONFIG_PREBOOT 731 732 When this option is #defined, the existence of the 733 environment variable "preboot" will be checked 734 immediately before starting the CONFIG_BOOTDELAY 735 countdown and/or running the auto-boot command resp. 736 entering interactive mode. 737 738 This feature is especially useful when "preboot" is 739 automatically generated or modified. For an example 740 see the LWMON board specific code: here "preboot" is 741 modified when the user holds down a certain 742 combination of keys on the (special) keyboard when 743 booting the systems 744 745- Serial Download Echo Mode: 746 CONFIG_LOADS_ECHO 747 If defined to 1, all characters received during a 748 serial download (using the "loads" command) are 749 echoed back. This might be needed by some terminal 750 emulations (like "cu"), but may as well just take 751 time on others. This setting #define's the initial 752 value of the "loads_echo" environment variable. 753 754- Kgdb Serial Baudrate: (if CONFIG_CMD_KGDB is defined) 755 CONFIG_KGDB_BAUDRATE 756 Select one of the baudrates listed in 757 CONFIG_SYS_BAUDRATE_TABLE, see below. 758 759- Monitor Functions: 760 Monitor commands can be included or excluded 761 from the build by using the #include files 762 <config_cmd_all.h> and #undef'ing unwanted 763 commands, or adding #define's for wanted commands. 764 765 The default command configuration includes all commands 766 except those marked below with a "*". 767 768 CONFIG_CMD_AES AES 128 CBC encrypt/decrypt 769 CONFIG_CMD_ASKENV * ask for env variable 770 CONFIG_CMD_BDI bdinfo 771 CONFIG_CMD_BOOTD bootd 772 CONFIG_CMD_BOOTI * ARM64 Linux kernel Image support 773 CONFIG_CMD_CACHE * icache, dcache 774 CONFIG_CMD_CONSOLE coninfo 775 CONFIG_CMD_DHCP * DHCP support 776 CONFIG_CMD_DIAG * Diagnostics 777 CONFIG_CMD_ECHO echo arguments 778 CONFIG_CMD_EDITENV edit env variable 779 CONFIG_CMD_ELF * bootelf, bootvx 780 CONFIG_CMD_ENV_EXISTS * check existence of env variable 781 CONFIG_CMD_EXPORTENV * export the environment 782 CONFIG_CMD_EXT2 * ext2 command support 783 CONFIG_CMD_EXT4 * ext4 command support 784 CONFIG_CMD_FS_GENERIC * filesystem commands (e.g. load, ls) 785 that work for multiple fs types 786 CONFIG_CMD_FS_UUID * Look up a filesystem UUID 787 CONFIG_CMD_SAVEENV saveenv 788 CONFIG_CMD_FLASH flinfo, erase, protect 789 CONFIG_CMD_FPGA FPGA device initialization support 790 CONFIG_CMD_GO * the 'go' command (exec code) 791 CONFIG_CMD_GREPENV * search environment 792 CONFIG_CMD_I2C * I2C serial bus support 793 CONFIG_CMD_IMI iminfo 794 CONFIG_CMD_IMLS List all images found in NOR flash 795 CONFIG_CMD_IMLS_NAND * List all images found in NAND flash 796 CONFIG_CMD_IMPORTENV * import an environment 797 CONFIG_CMD_INI * import data from an ini file into the env 798 CONFIG_CMD_ITEST Integer/string test of 2 values 799 CONFIG_CMD_LDRINFO * ldrinfo (display Blackfin loader) 800 CONFIG_CMD_LINK_LOCAL * link-local IP address auto-configuration 801 (169.254.*.*) 802 CONFIG_CMD_LOADB loadb 803 CONFIG_CMD_LOADS loads 804 CONFIG_CMD_MD5SUM * print md5 message digest 805 (requires CONFIG_CMD_MEMORY and CONFIG_MD5) 806 CONFIG_CMD_MEMINFO * Display detailed memory information 807 CONFIG_CMD_MEMORY md, mm, nm, mw, cp, cmp, crc, base, 808 loop, loopw 809 CONFIG_CMD_MEMTEST * mtest 810 CONFIG_CMD_MISC Misc functions like sleep etc 811 CONFIG_CMD_MMC * MMC memory mapped support 812 CONFIG_CMD_MII * MII utility commands 813 CONFIG_CMD_NET bootp, tftpboot, rarpboot 814 CONFIG_CMD_NFS NFS support 815 CONFIG_CMD_PING * send ICMP ECHO_REQUEST to network 816 host 817 CONFIG_CMD_PORTIO * Port I/O 818 CONFIG_CMD_READ * Read raw data from partition 819 CONFIG_CMD_REGINFO * Register dump 820 CONFIG_CMD_RUN run command in env variable 821 CONFIG_CMD_SANDBOX * sb command to access sandbox features 822 CONFIG_CMD_SAVES * save S record dump 823 CONFIG_CMD_SDRAM * print SDRAM configuration information 824 (requires CONFIG_CMD_I2C) 825 CONFIG_CMD_SF * Read/write/erase SPI NOR flash 826 CONFIG_CMD_SOFTSWITCH * Soft switch setting command for BF60x 827 CONFIG_CMD_SOURCE "source" command Support 828 CONFIG_CMD_SPI * SPI serial bus support 829 CONFIG_CMD_TFTPSRV * TFTP transfer in server mode 830 CONFIG_CMD_TFTPPUT * TFTP put command (upload) 831 CONFIG_CMD_TIME * run command and report execution time (ARM specific) 832 CONFIG_CMD_TIMER * access to the system tick timer 833 CONFIG_CMD_USB * USB support 834 CONFIG_CMD_CDP * Cisco Discover Protocol support 835 CONFIG_CMD_XIMG Load part of Multi Image 836 CONFIG_CMD_UUID * Generate random UUID or GUID string 837 838 EXAMPLE: If you want all functions except of network 839 support you can write: 840 841 #include "config_cmd_all.h" 842 #undef CONFIG_CMD_NET 843 844 Other Commands: 845 fdt (flattened device tree) command: CONFIG_OF_LIBFDT 846 847 Note: Don't enable the "icache" and "dcache" commands 848 (configuration option CONFIG_CMD_CACHE) unless you know 849 what you (and your U-Boot users) are doing. Data 850 cache cannot be enabled on systems like the 851 8xx (where accesses to the IMMR region must be 852 uncached), and it cannot be disabled on all other 853 systems where we (mis-) use the data cache to hold an 854 initial stack and some data. 855 856 857 XXX - this list needs to get updated! 858 859- Removal of commands 860 If no commands are needed to boot, you can disable 861 CONFIG_CMDLINE to remove them. In this case, the command line 862 will not be available, and when U-Boot wants to execute the 863 boot command (on start-up) it will call board_run_command() 864 instead. This can reduce image size significantly for very 865 simple boot procedures. 866 867- Regular expression support: 868 CONFIG_REGEX 869 If this variable is defined, U-Boot is linked against 870 the SLRE (Super Light Regular Expression) library, 871 which adds regex support to some commands, as for 872 example "env grep" and "setexpr". 873 874- Device tree: 875 CONFIG_OF_CONTROL 876 If this variable is defined, U-Boot will use a device tree 877 to configure its devices, instead of relying on statically 878 compiled #defines in the board file. This option is 879 experimental and only available on a few boards. The device 880 tree is available in the global data as gd->fdt_blob. 881 882 U-Boot needs to get its device tree from somewhere. This can 883 be done using one of the three options below: 884 885 CONFIG_OF_EMBED 886 If this variable is defined, U-Boot will embed a device tree 887 binary in its image. This device tree file should be in the 888 board directory and called <soc>-<board>.dts. The binary file 889 is then picked up in board_init_f() and made available through 890 the global data structure as gd->blob. 891 892 CONFIG_OF_SEPARATE 893 If this variable is defined, U-Boot will build a device tree 894 binary. It will be called u-boot.dtb. Architecture-specific 895 code will locate it at run-time. Generally this works by: 896 897 cat u-boot.bin u-boot.dtb >image.bin 898 899 and in fact, U-Boot does this for you, creating a file called 900 u-boot-dtb.bin which is useful in the common case. You can 901 still use the individual files if you need something more 902 exotic. 903 904 CONFIG_OF_BOARD 905 If this variable is defined, U-Boot will use the device tree 906 provided by the board at runtime instead of embedding one with 907 the image. Only boards defining board_fdt_blob_setup() support 908 this option (see include/fdtdec.h file). 909 910- Watchdog: 911 CONFIG_WATCHDOG 912 If this variable is defined, it enables watchdog 913 support for the SoC. There must be support in the SoC 914 specific code for a watchdog. For the 8xx 915 CPUs, the SIU Watchdog feature is enabled in the SYPCR 916 register. When supported for a specific SoC is 917 available, then no further board specific code should 918 be needed to use it. 919 920 CONFIG_HW_WATCHDOG 921 When using a watchdog circuitry external to the used 922 SoC, then define this variable and provide board 923 specific code for the "hw_watchdog_reset" function. 924 925 CONFIG_AT91_HW_WDT_TIMEOUT 926 specify the timeout in seconds. default 2 seconds. 927 928- U-Boot Version: 929 CONFIG_VERSION_VARIABLE 930 If this variable is defined, an environment variable 931 named "ver" is created by U-Boot showing the U-Boot 932 version as printed by the "version" command. 933 Any change to this variable will be reverted at the 934 next reset. 935 936- Real-Time Clock: 937 938 When CONFIG_CMD_DATE is selected, the type of the RTC 939 has to be selected, too. Define exactly one of the 940 following options: 941 942 CONFIG_RTC_PCF8563 - use Philips PCF8563 RTC 943 CONFIG_RTC_MC13XXX - use MC13783 or MC13892 RTC 944 CONFIG_RTC_MC146818 - use MC146818 RTC 945 CONFIG_RTC_DS1307 - use Maxim, Inc. DS1307 RTC 946 CONFIG_RTC_DS1337 - use Maxim, Inc. DS1337 RTC 947 CONFIG_RTC_DS1338 - use Maxim, Inc. DS1338 RTC 948 CONFIG_RTC_DS1339 - use Maxim, Inc. DS1339 RTC 949 CONFIG_RTC_DS164x - use Dallas DS164x RTC 950 CONFIG_RTC_ISL1208 - use Intersil ISL1208 RTC 951 CONFIG_RTC_MAX6900 - use Maxim, Inc. MAX6900 RTC 952 CONFIG_RTC_DS1337_NOOSC - Turn off the OSC output for DS1337 953 CONFIG_SYS_RV3029_TCR - enable trickle charger on 954 RV3029 RTC. 955 956 Note that if the RTC uses I2C, then the I2C interface 957 must also be configured. See I2C Support, below. 958 959- GPIO Support: 960 CONFIG_PCA953X - use NXP's PCA953X series I2C GPIO 961 962 The CONFIG_SYS_I2C_PCA953X_WIDTH option specifies a list of 963 chip-ngpio pairs that tell the PCA953X driver the number of 964 pins supported by a particular chip. 965 966 Note that if the GPIO device uses I2C, then the I2C interface 967 must also be configured. See I2C Support, below. 968 969- I/O tracing: 970 When CONFIG_IO_TRACE is selected, U-Boot intercepts all I/O 971 accesses and can checksum them or write a list of them out 972 to memory. See the 'iotrace' command for details. This is 973 useful for testing device drivers since it can confirm that 974 the driver behaves the same way before and after a code 975 change. Currently this is supported on sandbox and arm. To 976 add support for your architecture, add '#include <iotrace.h>' 977 to the bottom of arch/<arch>/include/asm/io.h and test. 978 979 Example output from the 'iotrace stats' command is below. 980 Note that if the trace buffer is exhausted, the checksum will 981 still continue to operate. 982 983 iotrace is enabled 984 Start: 10000000 (buffer start address) 985 Size: 00010000 (buffer size) 986 Offset: 00000120 (current buffer offset) 987 Output: 10000120 (start + offset) 988 Count: 00000018 (number of trace records) 989 CRC32: 9526fb66 (CRC32 of all trace records) 990 991- Timestamp Support: 992 993 When CONFIG_TIMESTAMP is selected, the timestamp 994 (date and time) of an image is printed by image 995 commands like bootm or iminfo. This option is 996 automatically enabled when you select CONFIG_CMD_DATE . 997 998- Partition Labels (disklabels) Supported: 999 Zero or more of the following: 1000 CONFIG_MAC_PARTITION Apple's MacOS partition table. 1001 CONFIG_ISO_PARTITION ISO partition table, used on CDROM etc. 1002 CONFIG_EFI_PARTITION GPT partition table, common when EFI is the 1003 bootloader. Note 2TB partition limit; see 1004 disk/part_efi.c 1005 CONFIG_MTD_PARTITIONS Memory Technology Device partition table. 1006 1007 If IDE or SCSI support is enabled (CONFIG_IDE or 1008 CONFIG_SCSI) you must configure support for at 1009 least one non-MTD partition type as well. 1010 1011- IDE Reset method: 1012 CONFIG_IDE_RESET_ROUTINE - this is defined in several 1013 board configurations files but used nowhere! 1014 1015 CONFIG_IDE_RESET - is this is defined, IDE Reset will 1016 be performed by calling the function 1017 ide_set_reset(int reset) 1018 which has to be defined in a board specific file 1019 1020- ATAPI Support: 1021 CONFIG_ATAPI 1022 1023 Set this to enable ATAPI support. 1024 1025- LBA48 Support 1026 CONFIG_LBA48 1027 1028 Set this to enable support for disks larger than 137GB 1029 Also look at CONFIG_SYS_64BIT_LBA. 1030 Whithout these , LBA48 support uses 32bit variables and will 'only' 1031 support disks up to 2.1TB. 1032 1033 CONFIG_SYS_64BIT_LBA: 1034 When enabled, makes the IDE subsystem use 64bit sector addresses. 1035 Default is 32bit. 1036 1037- SCSI Support: 1038 CONFIG_SYS_SCSI_MAX_LUN [8], CONFIG_SYS_SCSI_MAX_SCSI_ID [7] and 1039 CONFIG_SYS_SCSI_MAX_DEVICE [CONFIG_SYS_SCSI_MAX_SCSI_ID * 1040 CONFIG_SYS_SCSI_MAX_LUN] can be adjusted to define the 1041 maximum numbers of LUNs, SCSI ID's and target 1042 devices. 1043 1044 The environment variable 'scsidevs' is set to the number of 1045 SCSI devices found during the last scan. 1046 1047- NETWORK Support (PCI): 1048 CONFIG_E1000 1049 Support for Intel 8254x/8257x gigabit chips. 1050 1051 CONFIG_E1000_SPI 1052 Utility code for direct access to the SPI bus on Intel 8257x. 1053 This does not do anything useful unless you set at least one 1054 of CONFIG_CMD_E1000 or CONFIG_E1000_SPI_GENERIC. 1055 1056 CONFIG_E1000_SPI_GENERIC 1057 Allow generic access to the SPI bus on the Intel 8257x, for 1058 example with the "sspi" command. 1059 1060 CONFIG_CMD_E1000 1061 Management command for E1000 devices. When used on devices 1062 with SPI support you can reprogram the EEPROM from U-Boot. 1063 1064 CONFIG_EEPRO100 1065 Support for Intel 82557/82559/82559ER chips. 1066 Optional CONFIG_EEPRO100_SROM_WRITE enables EEPROM 1067 write routine for first time initialisation. 1068 1069 CONFIG_TULIP 1070 Support for Digital 2114x chips. 1071 Optional CONFIG_TULIP_SELECT_MEDIA for board specific 1072 modem chip initialisation (KS8761/QS6611). 1073 1074 CONFIG_NATSEMI 1075 Support for National dp83815 chips. 1076 1077 CONFIG_NS8382X 1078 Support for National dp8382[01] gigabit chips. 1079 1080- NETWORK Support (other): 1081 1082 CONFIG_DRIVER_AT91EMAC 1083 Support for AT91RM9200 EMAC. 1084 1085 CONFIG_RMII 1086 Define this to use reduced MII inteface 1087 1088 CONFIG_DRIVER_AT91EMAC_QUIET 1089 If this defined, the driver is quiet. 1090 The driver doen't show link status messages. 1091 1092 CONFIG_CALXEDA_XGMAC 1093 Support for the Calxeda XGMAC device 1094 1095 CONFIG_LAN91C96 1096 Support for SMSC's LAN91C96 chips. 1097 1098 CONFIG_LAN91C96_USE_32_BIT 1099 Define this to enable 32 bit addressing 1100 1101 CONFIG_SMC91111 1102 Support for SMSC's LAN91C111 chip 1103 1104 CONFIG_SMC91111_BASE 1105 Define this to hold the physical address 1106 of the device (I/O space) 1107 1108 CONFIG_SMC_USE_32_BIT 1109 Define this if data bus is 32 bits 1110 1111 CONFIG_SMC_USE_IOFUNCS 1112 Define this to use i/o functions instead of macros 1113 (some hardware wont work with macros) 1114 1115 CONFIG_DRIVER_TI_EMAC 1116 Support for davinci emac 1117 1118 CONFIG_SYS_DAVINCI_EMAC_PHY_COUNT 1119 Define this if you have more then 3 PHYs. 1120 1121 CONFIG_FTGMAC100 1122 Support for Faraday's FTGMAC100 Gigabit SoC Ethernet 1123 1124 CONFIG_FTGMAC100_EGIGA 1125 Define this to use GE link update with gigabit PHY. 1126 Define this if FTGMAC100 is connected to gigabit PHY. 1127 If your system has 10/100 PHY only, it might not occur 1128 wrong behavior. Because PHY usually return timeout or 1129 useless data when polling gigabit status and gigabit 1130 control registers. This behavior won't affect the 1131 correctnessof 10/100 link speed update. 1132 1133 CONFIG_SMC911X 1134 Support for SMSC's LAN911x and LAN921x chips 1135 1136 CONFIG_SMC911X_BASE 1137 Define this to hold the physical address 1138 of the device (I/O space) 1139 1140 CONFIG_SMC911X_32_BIT 1141 Define this if data bus is 32 bits 1142 1143 CONFIG_SMC911X_16_BIT 1144 Define this if data bus is 16 bits. If your processor 1145 automatically converts one 32 bit word to two 16 bit 1146 words you may also try CONFIG_SMC911X_32_BIT. 1147 1148 CONFIG_SH_ETHER 1149 Support for Renesas on-chip Ethernet controller 1150 1151 CONFIG_SH_ETHER_USE_PORT 1152 Define the number of ports to be used 1153 1154 CONFIG_SH_ETHER_PHY_ADDR 1155 Define the ETH PHY's address 1156 1157 CONFIG_SH_ETHER_CACHE_WRITEBACK 1158 If this option is set, the driver enables cache flush. 1159 1160- PWM Support: 1161 CONFIG_PWM_IMX 1162 Support for PWM module on the imx6. 1163 1164- TPM Support: 1165 CONFIG_TPM 1166 Support TPM devices. 1167 1168 CONFIG_TPM_TIS_INFINEON 1169 Support for Infineon i2c bus TPM devices. Only one device 1170 per system is supported at this time. 1171 1172 CONFIG_TPM_TIS_I2C_BURST_LIMITATION 1173 Define the burst count bytes upper limit 1174 1175 CONFIG_TPM_ST33ZP24 1176 Support for STMicroelectronics TPM devices. Requires DM_TPM support. 1177 1178 CONFIG_TPM_ST33ZP24_I2C 1179 Support for STMicroelectronics ST33ZP24 I2C devices. 1180 Requires TPM_ST33ZP24 and I2C. 1181 1182 CONFIG_TPM_ST33ZP24_SPI 1183 Support for STMicroelectronics ST33ZP24 SPI devices. 1184 Requires TPM_ST33ZP24 and SPI. 1185 1186 CONFIG_TPM_ATMEL_TWI 1187 Support for Atmel TWI TPM device. Requires I2C support. 1188 1189 CONFIG_TPM_TIS_LPC 1190 Support for generic parallel port TPM devices. Only one device 1191 per system is supported at this time. 1192 1193 CONFIG_TPM_TIS_BASE_ADDRESS 1194 Base address where the generic TPM device is mapped 1195 to. Contemporary x86 systems usually map it at 1196 0xfed40000. 1197 1198 CONFIG_CMD_TPM 1199 Add tpm monitor functions. 1200 Requires CONFIG_TPM. If CONFIG_TPM_AUTH_SESSIONS is set, also 1201 provides monitor access to authorized functions. 1202 1203 CONFIG_TPM 1204 Define this to enable the TPM support library which provides 1205 functional interfaces to some TPM commands. 1206 Requires support for a TPM device. 1207 1208 CONFIG_TPM_AUTH_SESSIONS 1209 Define this to enable authorized functions in the TPM library. 1210 Requires CONFIG_TPM and CONFIG_SHA1. 1211 1212- USB Support: 1213 At the moment only the UHCI host controller is 1214 supported (PIP405, MIP405); define 1215 CONFIG_USB_UHCI to enable it. 1216 define CONFIG_USB_KEYBOARD to enable the USB Keyboard 1217 and define CONFIG_USB_STORAGE to enable the USB 1218 storage devices. 1219 Note: 1220 Supported are USB Keyboards and USB Floppy drives 1221 (TEAC FD-05PUB). 1222 1223 CONFIG_USB_EHCI_TXFIFO_THRESH enables setting of the 1224 txfilltuning field in the EHCI controller on reset. 1225 1226 CONFIG_USB_DWC2_REG_ADDR the physical CPU address of the DWC2 1227 HW module registers. 1228 1229- USB Device: 1230 Define the below if you wish to use the USB console. 1231 Once firmware is rebuilt from a serial console issue the 1232 command "setenv stdin usbtty; setenv stdout usbtty" and 1233 attach your USB cable. The Unix command "dmesg" should print 1234 it has found a new device. The environment variable usbtty 1235 can be set to gserial or cdc_acm to enable your device to 1236 appear to a USB host as a Linux gserial device or a 1237 Common Device Class Abstract Control Model serial device. 1238 If you select usbtty = gserial you should be able to enumerate 1239 a Linux host by 1240 # modprobe usbserial vendor=0xVendorID product=0xProductID 1241 else if using cdc_acm, simply setting the environment 1242 variable usbtty to be cdc_acm should suffice. The following 1243 might be defined in YourBoardName.h 1244 1245 CONFIG_USB_DEVICE 1246 Define this to build a UDC device 1247 1248 CONFIG_USB_TTY 1249 Define this to have a tty type of device available to 1250 talk to the UDC device 1251 1252 CONFIG_USBD_HS 1253 Define this to enable the high speed support for usb 1254 device and usbtty. If this feature is enabled, a routine 1255 int is_usbd_high_speed(void) 1256 also needs to be defined by the driver to dynamically poll 1257 whether the enumeration has succeded at high speed or full 1258 speed. 1259 1260 CONFIG_SYS_CONSOLE_IS_IN_ENV 1261 Define this if you want stdin, stdout &/or stderr to 1262 be set to usbtty. 1263 1264 If you have a USB-IF assigned VendorID then you may wish to 1265 define your own vendor specific values either in BoardName.h 1266 or directly in usbd_vendor_info.h. If you don't define 1267 CONFIG_USBD_MANUFACTURER, CONFIG_USBD_PRODUCT_NAME, 1268 CONFIG_USBD_VENDORID and CONFIG_USBD_PRODUCTID, then U-Boot 1269 should pretend to be a Linux device to it's target host. 1270 1271 CONFIG_USBD_MANUFACTURER 1272 Define this string as the name of your company for 1273 - CONFIG_USBD_MANUFACTURER "my company" 1274 1275 CONFIG_USBD_PRODUCT_NAME 1276 Define this string as the name of your product 1277 - CONFIG_USBD_PRODUCT_NAME "acme usb device" 1278 1279 CONFIG_USBD_VENDORID 1280 Define this as your assigned Vendor ID from the USB 1281 Implementors Forum. This *must* be a genuine Vendor ID 1282 to avoid polluting the USB namespace. 1283 - CONFIG_USBD_VENDORID 0xFFFF 1284 1285 CONFIG_USBD_PRODUCTID 1286 Define this as the unique Product ID 1287 for your device 1288 - CONFIG_USBD_PRODUCTID 0xFFFF 1289 1290- ULPI Layer Support: 1291 The ULPI (UTMI Low Pin (count) Interface) PHYs are supported via 1292 the generic ULPI layer. The generic layer accesses the ULPI PHY 1293 via the platform viewport, so you need both the genric layer and 1294 the viewport enabled. Currently only Chipidea/ARC based 1295 viewport is supported. 1296 To enable the ULPI layer support, define CONFIG_USB_ULPI and 1297 CONFIG_USB_ULPI_VIEWPORT in your board configuration file. 1298 If your ULPI phy needs a different reference clock than the 1299 standard 24 MHz then you have to define CONFIG_ULPI_REF_CLK to 1300 the appropriate value in Hz. 1301 1302- MMC Support: 1303 The MMC controller on the Intel PXA is supported. To 1304 enable this define CONFIG_MMC. The MMC can be 1305 accessed from the boot prompt by mapping the device 1306 to physical memory similar to flash. Command line is 1307 enabled with CONFIG_CMD_MMC. The MMC driver also works with 1308 the FAT fs. This is enabled with CONFIG_CMD_FAT. 1309 1310 CONFIG_SH_MMCIF 1311 Support for Renesas on-chip MMCIF controller 1312 1313 CONFIG_SH_MMCIF_ADDR 1314 Define the base address of MMCIF registers 1315 1316 CONFIG_SH_MMCIF_CLK 1317 Define the clock frequency for MMCIF 1318 1319 CONFIG_SUPPORT_EMMC_BOOT 1320 Enable some additional features of the eMMC boot partitions. 1321 1322 CONFIG_SUPPORT_EMMC_RPMB 1323 Enable the commands for reading, writing and programming the 1324 key for the Replay Protection Memory Block partition in eMMC. 1325 1326- USB Device Firmware Update (DFU) class support: 1327 CONFIG_USB_FUNCTION_DFU 1328 This enables the USB portion of the DFU USB class 1329 1330 CONFIG_CMD_DFU 1331 This enables the command "dfu" which is used to have 1332 U-Boot create a DFU class device via USB. This command 1333 requires that the "dfu_alt_info" environment variable be 1334 set and define the alt settings to expose to the host. 1335 1336 CONFIG_DFU_MMC 1337 This enables support for exposing (e)MMC devices via DFU. 1338 1339 CONFIG_DFU_NAND 1340 This enables support for exposing NAND devices via DFU. 1341 1342 CONFIG_DFU_RAM 1343 This enables support for exposing RAM via DFU. 1344 Note: DFU spec refer to non-volatile memory usage, but 1345 allow usages beyond the scope of spec - here RAM usage, 1346 one that would help mostly the developer. 1347 1348 CONFIG_SYS_DFU_DATA_BUF_SIZE 1349 Dfu transfer uses a buffer before writing data to the 1350 raw storage device. Make the size (in bytes) of this buffer 1351 configurable. The size of this buffer is also configurable 1352 through the "dfu_bufsiz" environment variable. 1353 1354 CONFIG_SYS_DFU_MAX_FILE_SIZE 1355 When updating files rather than the raw storage device, 1356 we use a static buffer to copy the file into and then write 1357 the buffer once we've been given the whole file. Define 1358 this to the maximum filesize (in bytes) for the buffer. 1359 Default is 4 MiB if undefined. 1360 1361 DFU_DEFAULT_POLL_TIMEOUT 1362 Poll timeout [ms], is the timeout a device can send to the 1363 host. The host must wait for this timeout before sending 1364 a subsequent DFU_GET_STATUS request to the device. 1365 1366 DFU_MANIFEST_POLL_TIMEOUT 1367 Poll timeout [ms], which the device sends to the host when 1368 entering dfuMANIFEST state. Host waits this timeout, before 1369 sending again an USB request to the device. 1370 1371- USB Device Android Fastboot support: 1372 CONFIG_USB_FUNCTION_FASTBOOT 1373 This enables the USB part of the fastboot gadget 1374 1375 CONFIG_CMD_FASTBOOT 1376 This enables the command "fastboot" which enables the Android 1377 fastboot mode for the platform's USB device. Fastboot is a USB 1378 protocol for downloading images, flashing and device control 1379 used on Android devices. 1380 See doc/README.android-fastboot for more information. 1381 1382 CONFIG_ANDROID_BOOT_IMAGE 1383 This enables support for booting images which use the Android 1384 image format header. 1385 1386 CONFIG_FASTBOOT_BUF_ADDR 1387 The fastboot protocol requires a large memory buffer for 1388 downloads. Define this to the starting RAM address to use for 1389 downloaded images. 1390 1391 CONFIG_FASTBOOT_BUF_SIZE 1392 The fastboot protocol requires a large memory buffer for 1393 downloads. This buffer should be as large as possible for a 1394 platform. Define this to the size available RAM for fastboot. 1395 1396 CONFIG_FASTBOOT_FLASH 1397 The fastboot protocol includes a "flash" command for writing 1398 the downloaded image to a non-volatile storage device. Define 1399 this to enable the "fastboot flash" command. 1400 1401 CONFIG_FASTBOOT_FLASH_MMC_DEV 1402 The fastboot "flash" command requires additional information 1403 regarding the non-volatile storage device. Define this to 1404 the eMMC device that fastboot should use to store the image. 1405 1406 CONFIG_FASTBOOT_GPT_NAME 1407 The fastboot "flash" command supports writing the downloaded 1408 image to the Protective MBR and the Primary GUID Partition 1409 Table. (Additionally, this downloaded image is post-processed 1410 to generate and write the Backup GUID Partition Table.) 1411 This occurs when the specified "partition name" on the 1412 "fastboot flash" command line matches this value. 1413 The default is "gpt" if undefined. 1414 1415 CONFIG_FASTBOOT_MBR_NAME 1416 The fastboot "flash" command supports writing the downloaded 1417 image to DOS MBR. 1418 This occurs when the "partition name" specified on the 1419 "fastboot flash" command line matches this value. 1420 If not defined the default value "mbr" is used. 1421 1422- Journaling Flash filesystem support: 1423 CONFIG_JFFS2_NAND 1424 Define these for a default partition on a NAND device 1425 1426 CONFIG_SYS_JFFS2_FIRST_SECTOR, 1427 CONFIG_SYS_JFFS2_FIRST_BANK, CONFIG_SYS_JFFS2_NUM_BANKS 1428 Define these for a default partition on a NOR device 1429 1430- Keyboard Support: 1431 See Kconfig help for available keyboard drivers. 1432 1433 CONFIG_KEYBOARD 1434 1435 Define this to enable a custom keyboard support. 1436 This simply calls drv_keyboard_init() which must be 1437 defined in your board-specific files. This option is deprecated 1438 and is only used by novena. For new boards, use driver model 1439 instead. 1440 1441- Video support: 1442 CONFIG_FSL_DIU_FB 1443 Enable the Freescale DIU video driver. Reference boards for 1444 SOCs that have a DIU should define this macro to enable DIU 1445 support, and should also define these other macros: 1446 1447 CONFIG_SYS_DIU_ADDR 1448 CONFIG_VIDEO 1449 CONFIG_CFB_CONSOLE 1450 CONFIG_VIDEO_SW_CURSOR 1451 CONFIG_VGA_AS_SINGLE_DEVICE 1452 CONFIG_VIDEO_LOGO 1453 CONFIG_VIDEO_BMP_LOGO 1454 1455 The DIU driver will look for the 'video-mode' environment 1456 variable, and if defined, enable the DIU as a console during 1457 boot. See the documentation file doc/README.video for a 1458 description of this variable. 1459 1460- LCD Support: CONFIG_LCD 1461 1462 Define this to enable LCD support (for output to LCD 1463 display); also select one of the supported displays 1464 by defining one of these: 1465 1466 CONFIG_ATMEL_LCD: 1467 1468 HITACHI TX09D70VM1CCA, 3.5", 240x320. 1469 1470 CONFIG_NEC_NL6448AC33: 1471 1472 NEC NL6448AC33-18. Active, color, single scan. 1473 1474 CONFIG_NEC_NL6448BC20 1475 1476 NEC NL6448BC20-08. 6.5", 640x480. 1477 Active, color, single scan. 1478 1479 CONFIG_NEC_NL6448BC33_54 1480 1481 NEC NL6448BC33-54. 10.4", 640x480. 1482 Active, color, single scan. 1483 1484 CONFIG_SHARP_16x9 1485 1486 Sharp 320x240. Active, color, single scan. 1487 It isn't 16x9, and I am not sure what it is. 1488 1489 CONFIG_SHARP_LQ64D341 1490 1491 Sharp LQ64D341 display, 640x480. 1492 Active, color, single scan. 1493 1494 CONFIG_HLD1045 1495 1496 HLD1045 display, 640x480. 1497 Active, color, single scan. 1498 1499 CONFIG_OPTREX_BW 1500 1501 Optrex CBL50840-2 NF-FW 99 22 M5 1502 or 1503 Hitachi LMG6912RPFC-00T 1504 or 1505 Hitachi SP14Q002 1506 1507 320x240. Black & white. 1508 1509 CONFIG_LCD_ALIGNMENT 1510 1511 Normally the LCD is page-aligned (typically 4KB). If this is 1512 defined then the LCD will be aligned to this value instead. 1513 For ARM it is sometimes useful to use MMU_SECTION_SIZE 1514 here, since it is cheaper to change data cache settings on 1515 a per-section basis. 1516 1517 1518 CONFIG_LCD_ROTATION 1519 1520 Sometimes, for example if the display is mounted in portrait 1521 mode or even if it's mounted landscape but rotated by 180degree, 1522 we need to rotate our content of the display relative to the 1523 framebuffer, so that user can read the messages which are 1524 printed out. 1525 Once CONFIG_LCD_ROTATION is defined, the lcd_console will be 1526 initialized with a given rotation from "vl_rot" out of 1527 "vidinfo_t" which is provided by the board specific code. 1528 The value for vl_rot is coded as following (matching to 1529 fbcon=rotate:<n> linux-kernel commandline): 1530 0 = no rotation respectively 0 degree 1531 1 = 90 degree rotation 1532 2 = 180 degree rotation 1533 3 = 270 degree rotation 1534 1535 If CONFIG_LCD_ROTATION is not defined, the console will be 1536 initialized with 0degree rotation. 1537 1538 CONFIG_LCD_BMP_RLE8 1539 1540 Support drawing of RLE8-compressed bitmaps on the LCD. 1541 1542 CONFIG_I2C_EDID 1543 1544 Enables an 'i2c edid' command which can read EDID 1545 information over I2C from an attached LCD display. 1546 1547- Splash Screen Support: CONFIG_SPLASH_SCREEN 1548 1549 If this option is set, the environment is checked for 1550 a variable "splashimage". If found, the usual display 1551 of logo, copyright and system information on the LCD 1552 is suppressed and the BMP image at the address 1553 specified in "splashimage" is loaded instead. The 1554 console is redirected to the "nulldev", too. This 1555 allows for a "silent" boot where a splash screen is 1556 loaded very quickly after power-on. 1557 1558 CONFIG_SPLASHIMAGE_GUARD 1559 1560 If this option is set, then U-Boot will prevent the environment 1561 variable "splashimage" from being set to a problematic address 1562 (see doc/README.displaying-bmps). 1563 This option is useful for targets where, due to alignment 1564 restrictions, an improperly aligned BMP image will cause a data 1565 abort. If you think you will not have problems with unaligned 1566 accesses (for example because your toolchain prevents them) 1567 there is no need to set this option. 1568 1569 CONFIG_SPLASH_SCREEN_ALIGN 1570 1571 If this option is set the splash image can be freely positioned 1572 on the screen. Environment variable "splashpos" specifies the 1573 position as "x,y". If a positive number is given it is used as 1574 number of pixel from left/top. If a negative number is given it 1575 is used as number of pixel from right/bottom. You can also 1576 specify 'm' for centering the image. 1577 1578 Example: 1579 setenv splashpos m,m 1580 => image at center of screen 1581 1582 setenv splashpos 30,20 1583 => image at x = 30 and y = 20 1584 1585 setenv splashpos -10,m 1586 => vertically centered image 1587 at x = dspWidth - bmpWidth - 9 1588 1589- Gzip compressed BMP image support: CONFIG_VIDEO_BMP_GZIP 1590 1591 If this option is set, additionally to standard BMP 1592 images, gzipped BMP images can be displayed via the 1593 splashscreen support or the bmp command. 1594 1595- Run length encoded BMP image (RLE8) support: CONFIG_VIDEO_BMP_RLE8 1596 1597 If this option is set, 8-bit RLE compressed BMP images 1598 can be displayed via the splashscreen support or the 1599 bmp command. 1600 1601- Compression support: 1602 CONFIG_GZIP 1603 1604 Enabled by default to support gzip compressed images. 1605 1606 CONFIG_BZIP2 1607 1608 If this option is set, support for bzip2 compressed 1609 images is included. If not, only uncompressed and gzip 1610 compressed images are supported. 1611 1612 NOTE: the bzip2 algorithm requires a lot of RAM, so 1613 the malloc area (as defined by CONFIG_SYS_MALLOC_LEN) should 1614 be at least 4MB. 1615 1616- MII/PHY support: 1617 CONFIG_PHY_ADDR 1618 1619 The address of PHY on MII bus. 1620 1621 CONFIG_PHY_CLOCK_FREQ (ppc4xx) 1622 1623 The clock frequency of the MII bus 1624 1625 CONFIG_PHY_RESET_DELAY 1626 1627 Some PHY like Intel LXT971A need extra delay after 1628 reset before any MII register access is possible. 1629 For such PHY, set this option to the usec delay 1630 required. (minimum 300usec for LXT971A) 1631 1632 CONFIG_PHY_CMD_DELAY (ppc4xx) 1633 1634 Some PHY like Intel LXT971A need extra delay after 1635 command issued before MII status register can be read 1636 1637- IP address: 1638 CONFIG_IPADDR 1639 1640 Define a default value for the IP address to use for 1641 the default Ethernet interface, in case this is not 1642 determined through e.g. bootp. 1643 (Environment variable "ipaddr") 1644 1645- Server IP address: 1646 CONFIG_SERVERIP 1647 1648 Defines a default value for the IP address of a TFTP 1649 server to contact when using the "tftboot" command. 1650 (Environment variable "serverip") 1651 1652 CONFIG_KEEP_SERVERADDR 1653 1654 Keeps the server's MAC address, in the env 'serveraddr' 1655 for passing to bootargs (like Linux's netconsole option) 1656 1657- Gateway IP address: 1658 CONFIG_GATEWAYIP 1659 1660 Defines a default value for the IP address of the 1661 default router where packets to other networks are 1662 sent to. 1663 (Environment variable "gatewayip") 1664 1665- Subnet mask: 1666 CONFIG_NETMASK 1667 1668 Defines a default value for the subnet mask (or 1669 routing prefix) which is used to determine if an IP 1670 address belongs to the local subnet or needs to be 1671 forwarded through a router. 1672 (Environment variable "netmask") 1673 1674- Multicast TFTP Mode: 1675 CONFIG_MCAST_TFTP 1676 1677 Defines whether you want to support multicast TFTP as per 1678 rfc-2090; for example to work with atftp. Lets lots of targets 1679 tftp down the same boot image concurrently. Note: the Ethernet 1680 driver in use must provide a function: mcast() to join/leave a 1681 multicast group. 1682 1683- BOOTP Recovery Mode: 1684 CONFIG_BOOTP_RANDOM_DELAY 1685 1686 If you have many targets in a network that try to 1687 boot using BOOTP, you may want to avoid that all 1688 systems send out BOOTP requests at precisely the same 1689 moment (which would happen for instance at recovery 1690 from a power failure, when all systems will try to 1691 boot, thus flooding the BOOTP server. Defining 1692 CONFIG_BOOTP_RANDOM_DELAY causes a random delay to be 1693 inserted before sending out BOOTP requests. The 1694 following delays are inserted then: 1695 1696 1st BOOTP request: delay 0 ... 1 sec 1697 2nd BOOTP request: delay 0 ... 2 sec 1698 3rd BOOTP request: delay 0 ... 4 sec 1699 4th and following 1700 BOOTP requests: delay 0 ... 8 sec 1701 1702 CONFIG_BOOTP_ID_CACHE_SIZE 1703 1704 BOOTP packets are uniquely identified using a 32-bit ID. The 1705 server will copy the ID from client requests to responses and 1706 U-Boot will use this to determine if it is the destination of 1707 an incoming response. Some servers will check that addresses 1708 aren't in use before handing them out (usually using an ARP 1709 ping) and therefore take up to a few hundred milliseconds to 1710 respond. Network congestion may also influence the time it 1711 takes for a response to make it back to the client. If that 1712 time is too long, U-Boot will retransmit requests. In order 1713 to allow earlier responses to still be accepted after these 1714 retransmissions, U-Boot's BOOTP client keeps a small cache of 1715 IDs. The CONFIG_BOOTP_ID_CACHE_SIZE controls the size of this 1716 cache. The default is to keep IDs for up to four outstanding 1717 requests. Increasing this will allow U-Boot to accept offers 1718 from a BOOTP client in networks with unusually high latency. 1719 1720- DHCP Advanced Options: 1721 You can fine tune the DHCP functionality by defining 1722 CONFIG_BOOTP_* symbols: 1723 1724 CONFIG_BOOTP_SUBNETMASK 1725 CONFIG_BOOTP_GATEWAY 1726 CONFIG_BOOTP_HOSTNAME 1727 CONFIG_BOOTP_NISDOMAIN 1728 CONFIG_BOOTP_BOOTPATH 1729 CONFIG_BOOTP_BOOTFILESIZE 1730 CONFIG_BOOTP_DNS 1731 CONFIG_BOOTP_DNS2 1732 CONFIG_BOOTP_SEND_HOSTNAME 1733 CONFIG_BOOTP_NTPSERVER 1734 CONFIG_BOOTP_TIMEOFFSET 1735 CONFIG_BOOTP_VENDOREX 1736 CONFIG_BOOTP_MAY_FAIL 1737 1738 CONFIG_BOOTP_SERVERIP - TFTP server will be the serverip 1739 environment variable, not the BOOTP server. 1740 1741 CONFIG_BOOTP_MAY_FAIL - If the DHCP server is not found 1742 after the configured retry count, the call will fail 1743 instead of starting over. This can be used to fail over 1744 to Link-local IP address configuration if the DHCP server 1745 is not available. 1746 1747 CONFIG_BOOTP_DNS2 - If a DHCP client requests the DNS 1748 serverip from a DHCP server, it is possible that more 1749 than one DNS serverip is offered to the client. 1750 If CONFIG_BOOTP_DNS2 is enabled, the secondary DNS 1751 serverip will be stored in the additional environment 1752 variable "dnsip2". The first DNS serverip is always 1753 stored in the variable "dnsip", when CONFIG_BOOTP_DNS 1754 is defined. 1755 1756 CONFIG_BOOTP_SEND_HOSTNAME - Some DHCP servers are capable 1757 to do a dynamic update of a DNS server. To do this, they 1758 need the hostname of the DHCP requester. 1759 If CONFIG_BOOTP_SEND_HOSTNAME is defined, the content 1760 of the "hostname" environment variable is passed as 1761 option 12 to the DHCP server. 1762 1763 CONFIG_BOOTP_DHCP_REQUEST_DELAY 1764 1765 A 32bit value in microseconds for a delay between 1766 receiving a "DHCP Offer" and sending the "DHCP Request". 1767 This fixes a problem with certain DHCP servers that don't 1768 respond 100% of the time to a "DHCP request". E.g. On an 1769 AT91RM9200 processor running at 180MHz, this delay needed 1770 to be *at least* 15,000 usec before a Windows Server 2003 1771 DHCP server would reply 100% of the time. I recommend at 1772 least 50,000 usec to be safe. The alternative is to hope 1773 that one of the retries will be successful but note that 1774 the DHCP timeout and retry process takes a longer than 1775 this delay. 1776 1777 - Link-local IP address negotiation: 1778 Negotiate with other link-local clients on the local network 1779 for an address that doesn't require explicit configuration. 1780 This is especially useful if a DHCP server cannot be guaranteed 1781 to exist in all environments that the device must operate. 1782 1783 See doc/README.link-local for more information. 1784 1785 - CDP Options: 1786 CONFIG_CDP_DEVICE_ID 1787 1788 The device id used in CDP trigger frames. 1789 1790 CONFIG_CDP_DEVICE_ID_PREFIX 1791 1792 A two character string which is prefixed to the MAC address 1793 of the device. 1794 1795 CONFIG_CDP_PORT_ID 1796 1797 A printf format string which contains the ascii name of 1798 the port. Normally is set to "eth%d" which sets 1799 eth0 for the first Ethernet, eth1 for the second etc. 1800 1801 CONFIG_CDP_CAPABILITIES 1802 1803 A 32bit integer which indicates the device capabilities; 1804 0x00000010 for a normal host which does not forwards. 1805 1806 CONFIG_CDP_VERSION 1807 1808 An ascii string containing the version of the software. 1809 1810 CONFIG_CDP_PLATFORM 1811 1812 An ascii string containing the name of the platform. 1813 1814 CONFIG_CDP_TRIGGER 1815 1816 A 32bit integer sent on the trigger. 1817 1818 CONFIG_CDP_POWER_CONSUMPTION 1819 1820 A 16bit integer containing the power consumption of the 1821 device in .1 of milliwatts. 1822 1823 CONFIG_CDP_APPLIANCE_VLAN_TYPE 1824 1825 A byte containing the id of the VLAN. 1826 1827- Status LED: CONFIG_LED_STATUS 1828 1829 Several configurations allow to display the current 1830 status using a LED. For instance, the LED will blink 1831 fast while running U-Boot code, stop blinking as 1832 soon as a reply to a BOOTP request was received, and 1833 start blinking slow once the Linux kernel is running 1834 (supported by a status LED driver in the Linux 1835 kernel). Defining CONFIG_LED_STATUS enables this 1836 feature in U-Boot. 1837 1838 Additional options: 1839 1840 CONFIG_LED_STATUS_GPIO 1841 The status LED can be connected to a GPIO pin. 1842 In such cases, the gpio_led driver can be used as a 1843 status LED backend implementation. Define CONFIG_LED_STATUS_GPIO 1844 to include the gpio_led driver in the U-Boot binary. 1845 1846 CONFIG_GPIO_LED_INVERTED_TABLE 1847 Some GPIO connected LEDs may have inverted polarity in which 1848 case the GPIO high value corresponds to LED off state and 1849 GPIO low value corresponds to LED on state. 1850 In such cases CONFIG_GPIO_LED_INVERTED_TABLE may be defined 1851 with a list of GPIO LEDs that have inverted polarity. 1852 1853- I2C Support: CONFIG_SYS_I2C 1854 1855 This enable the NEW i2c subsystem, and will allow you to use 1856 i2c commands at the u-boot command line (as long as you set 1857 CONFIG_CMD_I2C in CONFIG_COMMANDS) and communicate with i2c 1858 based realtime clock chips or other i2c devices. See 1859 common/cmd_i2c.c for a description of the command line 1860 interface. 1861 1862 ported i2c driver to the new framework: 1863 - drivers/i2c/soft_i2c.c: 1864 - activate first bus with CONFIG_SYS_I2C_SOFT define 1865 CONFIG_SYS_I2C_SOFT_SPEED and CONFIG_SYS_I2C_SOFT_SLAVE 1866 for defining speed and slave address 1867 - activate second bus with I2C_SOFT_DECLARATIONS2 define 1868 CONFIG_SYS_I2C_SOFT_SPEED_2 and CONFIG_SYS_I2C_SOFT_SLAVE_2 1869 for defining speed and slave address 1870 - activate third bus with I2C_SOFT_DECLARATIONS3 define 1871 CONFIG_SYS_I2C_SOFT_SPEED_3 and CONFIG_SYS_I2C_SOFT_SLAVE_3 1872 for defining speed and slave address 1873 - activate fourth bus with I2C_SOFT_DECLARATIONS4 define 1874 CONFIG_SYS_I2C_SOFT_SPEED_4 and CONFIG_SYS_I2C_SOFT_SLAVE_4 1875 for defining speed and slave address 1876 1877 - drivers/i2c/fsl_i2c.c: 1878 - activate i2c driver with CONFIG_SYS_I2C_FSL 1879 define CONFIG_SYS_FSL_I2C_OFFSET for setting the register 1880 offset CONFIG_SYS_FSL_I2C_SPEED for the i2c speed and 1881 CONFIG_SYS_FSL_I2C_SLAVE for the slave addr of the first 1882 bus. 1883 - If your board supports a second fsl i2c bus, define 1884 CONFIG_SYS_FSL_I2C2_OFFSET for the register offset 1885 CONFIG_SYS_FSL_I2C2_SPEED for the speed and 1886 CONFIG_SYS_FSL_I2C2_SLAVE for the slave address of the 1887 second bus. 1888 1889 - drivers/i2c/tegra_i2c.c: 1890 - activate this driver with CONFIG_SYS_I2C_TEGRA 1891 - This driver adds 4 i2c buses with a fix speed from 1892 100000 and the slave addr 0! 1893 1894 - drivers/i2c/ppc4xx_i2c.c 1895 - activate this driver with CONFIG_SYS_I2C_PPC4XX 1896 - CONFIG_SYS_I2C_PPC4XX_CH0 activate hardware channel 0 1897 - CONFIG_SYS_I2C_PPC4XX_CH1 activate hardware channel 1 1898 1899 - drivers/i2c/i2c_mxc.c 1900 - activate this driver with CONFIG_SYS_I2C_MXC 1901 - enable bus 1 with CONFIG_SYS_I2C_MXC_I2C1 1902 - enable bus 2 with CONFIG_SYS_I2C_MXC_I2C2 1903 - enable bus 3 with CONFIG_SYS_I2C_MXC_I2C3 1904 - enable bus 4 with CONFIG_SYS_I2C_MXC_I2C4 1905 - define speed for bus 1 with CONFIG_SYS_MXC_I2C1_SPEED 1906 - define slave for bus 1 with CONFIG_SYS_MXC_I2C1_SLAVE 1907 - define speed for bus 2 with CONFIG_SYS_MXC_I2C2_SPEED 1908 - define slave for bus 2 with CONFIG_SYS_MXC_I2C2_SLAVE 1909 - define speed for bus 3 with CONFIG_SYS_MXC_I2C3_SPEED 1910 - define slave for bus 3 with CONFIG_SYS_MXC_I2C3_SLAVE 1911 - define speed for bus 4 with CONFIG_SYS_MXC_I2C4_SPEED 1912 - define slave for bus 4 with CONFIG_SYS_MXC_I2C4_SLAVE 1913 If those defines are not set, default value is 100000 1914 for speed, and 0 for slave. 1915 1916 - drivers/i2c/rcar_i2c.c: 1917 - activate this driver with CONFIG_SYS_I2C_RCAR 1918 - This driver adds 4 i2c buses 1919 1920 - CONFIG_SYS_RCAR_I2C0_BASE for setting the register channel 0 1921 - CONFIG_SYS_RCAR_I2C0_SPEED for for the speed channel 0 1922 - CONFIG_SYS_RCAR_I2C1_BASE for setting the register channel 1 1923 - CONFIG_SYS_RCAR_I2C1_SPEED for for the speed channel 1 1924 - CONFIG_SYS_RCAR_I2C2_BASE for setting the register channel 2 1925 - CONFIG_SYS_RCAR_I2C2_SPEED for for the speed channel 2 1926 - CONFIG_SYS_RCAR_I2C3_BASE for setting the register channel 3 1927 - CONFIG_SYS_RCAR_I2C3_SPEED for for the speed channel 3 1928 - CONFIF_SYS_RCAR_I2C_NUM_CONTROLLERS for number of i2c buses 1929 1930 - drivers/i2c/sh_i2c.c: 1931 - activate this driver with CONFIG_SYS_I2C_SH 1932 - This driver adds from 2 to 5 i2c buses 1933 1934 - CONFIG_SYS_I2C_SH_BASE0 for setting the register channel 0 1935 - CONFIG_SYS_I2C_SH_SPEED0 for for the speed channel 0 1936 - CONFIG_SYS_I2C_SH_BASE1 for setting the register channel 1 1937 - CONFIG_SYS_I2C_SH_SPEED1 for for the speed channel 1 1938 - CONFIG_SYS_I2C_SH_BASE2 for setting the register channel 2 1939 - CONFIG_SYS_I2C_SH_SPEED2 for for the speed channel 2 1940 - CONFIG_SYS_I2C_SH_BASE3 for setting the register channel 3 1941 - CONFIG_SYS_I2C_SH_SPEED3 for for the speed channel 3 1942 - CONFIG_SYS_I2C_SH_BASE4 for setting the register channel 4 1943 - CONFIG_SYS_I2C_SH_SPEED4 for for the speed channel 4 1944 - CONFIG_SYS_I2C_SH_NUM_CONTROLLERS for number of i2c buses 1945 1946 - drivers/i2c/omap24xx_i2c.c 1947 - activate this driver with CONFIG_SYS_I2C_OMAP24XX 1948 - CONFIG_SYS_OMAP24_I2C_SPEED speed channel 0 1949 - CONFIG_SYS_OMAP24_I2C_SLAVE slave addr channel 0 1950 - CONFIG_SYS_OMAP24_I2C_SPEED1 speed channel 1 1951 - CONFIG_SYS_OMAP24_I2C_SLAVE1 slave addr channel 1 1952 - CONFIG_SYS_OMAP24_I2C_SPEED2 speed channel 2 1953 - CONFIG_SYS_OMAP24_I2C_SLAVE2 slave addr channel 2 1954 - CONFIG_SYS_OMAP24_I2C_SPEED3 speed channel 3 1955 - CONFIG_SYS_OMAP24_I2C_SLAVE3 slave addr channel 3 1956 - CONFIG_SYS_OMAP24_I2C_SPEED4 speed channel 4 1957 - CONFIG_SYS_OMAP24_I2C_SLAVE4 slave addr channel 4 1958 1959 - drivers/i2c/zynq_i2c.c 1960 - activate this driver with CONFIG_SYS_I2C_ZYNQ 1961 - set CONFIG_SYS_I2C_ZYNQ_SPEED for speed setting 1962 - set CONFIG_SYS_I2C_ZYNQ_SLAVE for slave addr 1963 1964 - drivers/i2c/s3c24x0_i2c.c: 1965 - activate this driver with CONFIG_SYS_I2C_S3C24X0 1966 - This driver adds i2c buses (11 for Exynos5250, Exynos5420 1967 9 i2c buses for Exynos4 and 1 for S3C24X0 SoCs from Samsung) 1968 with a fix speed from 100000 and the slave addr 0! 1969 1970 - drivers/i2c/ihs_i2c.c 1971 - activate this driver with CONFIG_SYS_I2C_IHS 1972 - CONFIG_SYS_I2C_IHS_CH0 activate hardware channel 0 1973 - CONFIG_SYS_I2C_IHS_SPEED_0 speed channel 0 1974 - CONFIG_SYS_I2C_IHS_SLAVE_0 slave addr channel 0 1975 - CONFIG_SYS_I2C_IHS_CH1 activate hardware channel 1 1976 - CONFIG_SYS_I2C_IHS_SPEED_1 speed channel 1 1977 - CONFIG_SYS_I2C_IHS_SLAVE_1 slave addr channel 1 1978 - CONFIG_SYS_I2C_IHS_CH2 activate hardware channel 2 1979 - CONFIG_SYS_I2C_IHS_SPEED_2 speed channel 2 1980 - CONFIG_SYS_I2C_IHS_SLAVE_2 slave addr channel 2 1981 - CONFIG_SYS_I2C_IHS_CH3 activate hardware channel 3 1982 - CONFIG_SYS_I2C_IHS_SPEED_3 speed channel 3 1983 - CONFIG_SYS_I2C_IHS_SLAVE_3 slave addr channel 3 1984 - activate dual channel with CONFIG_SYS_I2C_IHS_DUAL 1985 - CONFIG_SYS_I2C_IHS_SPEED_0_1 speed channel 0_1 1986 - CONFIG_SYS_I2C_IHS_SLAVE_0_1 slave addr channel 0_1 1987 - CONFIG_SYS_I2C_IHS_SPEED_1_1 speed channel 1_1 1988 - CONFIG_SYS_I2C_IHS_SLAVE_1_1 slave addr channel 1_1 1989 - CONFIG_SYS_I2C_IHS_SPEED_2_1 speed channel 2_1 1990 - CONFIG_SYS_I2C_IHS_SLAVE_2_1 slave addr channel 2_1 1991 - CONFIG_SYS_I2C_IHS_SPEED_3_1 speed channel 3_1 1992 - CONFIG_SYS_I2C_IHS_SLAVE_3_1 slave addr channel 3_1 1993 1994 additional defines: 1995 1996 CONFIG_SYS_NUM_I2C_BUSES 1997 Hold the number of i2c buses you want to use. 1998 1999 CONFIG_SYS_I2C_DIRECT_BUS 2000 define this, if you don't use i2c muxes on your hardware. 2001 if CONFIG_SYS_I2C_MAX_HOPS is not defined or == 0 you can 2002 omit this define. 2003 2004 CONFIG_SYS_I2C_MAX_HOPS 2005 define how many muxes are maximal consecutively connected 2006 on one i2c bus. If you not use i2c muxes, omit this 2007 define. 2008 2009 CONFIG_SYS_I2C_BUSES 2010 hold a list of buses you want to use, only used if 2011 CONFIG_SYS_I2C_DIRECT_BUS is not defined, for example 2012 a board with CONFIG_SYS_I2C_MAX_HOPS = 1 and 2013 CONFIG_SYS_NUM_I2C_BUSES = 9: 2014 2015 CONFIG_SYS_I2C_BUSES {{0, {I2C_NULL_HOP}}, \ 2016 {0, {{I2C_MUX_PCA9547, 0x70, 1}}}, \ 2017 {0, {{I2C_MUX_PCA9547, 0x70, 2}}}, \ 2018 {0, {{I2C_MUX_PCA9547, 0x70, 3}}}, \ 2019 {0, {{I2C_MUX_PCA9547, 0x70, 4}}}, \ 2020 {0, {{I2C_MUX_PCA9547, 0x70, 5}}}, \ 2021 {1, {I2C_NULL_HOP}}, \ 2022 {1, {{I2C_MUX_PCA9544, 0x72, 1}}}, \ 2023 {1, {{I2C_MUX_PCA9544, 0x72, 2}}}, \ 2024 } 2025 2026 which defines 2027 bus 0 on adapter 0 without a mux 2028 bus 1 on adapter 0 with a PCA9547 on address 0x70 port 1 2029 bus 2 on adapter 0 with a PCA9547 on address 0x70 port 2 2030 bus 3 on adapter 0 with a PCA9547 on address 0x70 port 3 2031 bus 4 on adapter 0 with a PCA9547 on address 0x70 port 4 2032 bus 5 on adapter 0 with a PCA9547 on address 0x70 port 5 2033 bus 6 on adapter 1 without a mux 2034 bus 7 on adapter 1 with a PCA9544 on address 0x72 port 1 2035 bus 8 on adapter 1 with a PCA9544 on address 0x72 port 2 2036 2037 If you do not have i2c muxes on your board, omit this define. 2038 2039- Legacy I2C Support: 2040 If you use the software i2c interface (CONFIG_SYS_I2C_SOFT) 2041 then the following macros need to be defined (examples are 2042 from include/configs/lwmon.h): 2043 2044 I2C_INIT 2045 2046 (Optional). Any commands necessary to enable the I2C 2047 controller or configure ports. 2048 2049 eg: #define I2C_INIT (immr->im_cpm.cp_pbdir |= PB_SCL) 2050 2051 I2C_ACTIVE 2052 2053 The code necessary to make the I2C data line active 2054 (driven). If the data line is open collector, this 2055 define can be null. 2056 2057 eg: #define I2C_ACTIVE (immr->im_cpm.cp_pbdir |= PB_SDA) 2058 2059 I2C_TRISTATE 2060 2061 The code necessary to make the I2C data line tri-stated 2062 (inactive). If the data line is open collector, this 2063 define can be null. 2064 2065 eg: #define I2C_TRISTATE (immr->im_cpm.cp_pbdir &= ~PB_SDA) 2066 2067 I2C_READ 2068 2069 Code that returns true if the I2C data line is high, 2070 false if it is low. 2071 2072 eg: #define I2C_READ ((immr->im_cpm.cp_pbdat & PB_SDA) != 0) 2073 2074 I2C_SDA(bit) 2075 2076 If <bit> is true, sets the I2C data line high. If it 2077 is false, it clears it (low). 2078 2079 eg: #define I2C_SDA(bit) \ 2080 if(bit) immr->im_cpm.cp_pbdat |= PB_SDA; \ 2081 else immr->im_cpm.cp_pbdat &= ~PB_SDA 2082 2083 I2C_SCL(bit) 2084 2085 If <bit> is true, sets the I2C clock line high. If it 2086 is false, it clears it (low). 2087 2088 eg: #define I2C_SCL(bit) \ 2089 if(bit) immr->im_cpm.cp_pbdat |= PB_SCL; \ 2090 else immr->im_cpm.cp_pbdat &= ~PB_SCL 2091 2092 I2C_DELAY 2093 2094 This delay is invoked four times per clock cycle so this 2095 controls the rate of data transfer. The data rate thus 2096 is 1 / (I2C_DELAY * 4). Often defined to be something 2097 like: 2098 2099 #define I2C_DELAY udelay(2) 2100 2101 CONFIG_SOFT_I2C_GPIO_SCL / CONFIG_SOFT_I2C_GPIO_SDA 2102 2103 If your arch supports the generic GPIO framework (asm/gpio.h), 2104 then you may alternatively define the two GPIOs that are to be 2105 used as SCL / SDA. Any of the previous I2C_xxx macros will 2106 have GPIO-based defaults assigned to them as appropriate. 2107 2108 You should define these to the GPIO value as given directly to 2109 the generic GPIO functions. 2110 2111 CONFIG_SYS_I2C_INIT_BOARD 2112 2113 When a board is reset during an i2c bus transfer 2114 chips might think that the current transfer is still 2115 in progress. On some boards it is possible to access 2116 the i2c SCLK line directly, either by using the 2117 processor pin as a GPIO or by having a second pin 2118 connected to the bus. If this option is defined a 2119 custom i2c_init_board() routine in boards/xxx/board.c 2120 is run early in the boot sequence. 2121 2122 CONFIG_I2C_MULTI_BUS 2123 2124 This option allows the use of multiple I2C buses, each of which 2125 must have a controller. At any point in time, only one bus is 2126 active. To switch to a different bus, use the 'i2c dev' command. 2127 Note that bus numbering is zero-based. 2128 2129 CONFIG_SYS_I2C_NOPROBES 2130 2131 This option specifies a list of I2C devices that will be skipped 2132 when the 'i2c probe' command is issued. If CONFIG_I2C_MULTI_BUS 2133 is set, specify a list of bus-device pairs. Otherwise, specify 2134 a 1D array of device addresses 2135 2136 e.g. 2137 #undef CONFIG_I2C_MULTI_BUS 2138 #define CONFIG_SYS_I2C_NOPROBES {0x50,0x68} 2139 2140 will skip addresses 0x50 and 0x68 on a board with one I2C bus 2141 2142 #define CONFIG_I2C_MULTI_BUS 2143 #define CONFIG_SYS_I2C_NOPROBES {{0,0x50},{0,0x68},{1,0x54}} 2144 2145 will skip addresses 0x50 and 0x68 on bus 0 and address 0x54 on bus 1 2146 2147 CONFIG_SYS_SPD_BUS_NUM 2148 2149 If defined, then this indicates the I2C bus number for DDR SPD. 2150 If not defined, then U-Boot assumes that SPD is on I2C bus 0. 2151 2152 CONFIG_SYS_RTC_BUS_NUM 2153 2154 If defined, then this indicates the I2C bus number for the RTC. 2155 If not defined, then U-Boot assumes that RTC is on I2C bus 0. 2156 2157 CONFIG_SOFT_I2C_READ_REPEATED_START 2158 2159 defining this will force the i2c_read() function in 2160 the soft_i2c driver to perform an I2C repeated start 2161 between writing the address pointer and reading the 2162 data. If this define is omitted the default behaviour 2163 of doing a stop-start sequence will be used. Most I2C 2164 devices can use either method, but some require one or 2165 the other. 2166 2167- SPI Support: CONFIG_SPI 2168 2169 Enables SPI driver (so far only tested with 2170 SPI EEPROM, also an instance works with Crystal A/D and 2171 D/As on the SACSng board) 2172 2173 CONFIG_SH_SPI 2174 2175 Enables the driver for SPI controller on SuperH. Currently 2176 only SH7757 is supported. 2177 2178 CONFIG_SOFT_SPI 2179 2180 Enables a software (bit-bang) SPI driver rather than 2181 using hardware support. This is a general purpose 2182 driver that only requires three general I/O port pins 2183 (two outputs, one input) to function. If this is 2184 defined, the board configuration must define several 2185 SPI configuration items (port pins to use, etc). For 2186 an example, see include/configs/sacsng.h. 2187 2188 CONFIG_HARD_SPI 2189 2190 Enables a hardware SPI driver for general-purpose reads 2191 and writes. As with CONFIG_SOFT_SPI, the board configuration 2192 must define a list of chip-select function pointers. 2193 Currently supported on some MPC8xxx processors. For an 2194 example, see include/configs/mpc8349emds.h. 2195 2196 CONFIG_MXC_SPI 2197 2198 Enables the driver for the SPI controllers on i.MX and MXC 2199 SoCs. Currently i.MX31/35/51 are supported. 2200 2201 CONFIG_SYS_SPI_MXC_WAIT 2202 Timeout for waiting until spi transfer completed. 2203 default: (CONFIG_SYS_HZ/100) /* 10 ms */ 2204 2205- FPGA Support: CONFIG_FPGA 2206 2207 Enables FPGA subsystem. 2208 2209 CONFIG_FPGA_<vendor> 2210 2211 Enables support for specific chip vendors. 2212 (ALTERA, XILINX) 2213 2214 CONFIG_FPGA_<family> 2215 2216 Enables support for FPGA family. 2217 (SPARTAN2, SPARTAN3, VIRTEX2, CYCLONE2, ACEX1K, ACEX) 2218 2219 CONFIG_FPGA_COUNT 2220 2221 Specify the number of FPGA devices to support. 2222 2223 CONFIG_SYS_FPGA_PROG_FEEDBACK 2224 2225 Enable printing of hash marks during FPGA configuration. 2226 2227 CONFIG_SYS_FPGA_CHECK_BUSY 2228 2229 Enable checks on FPGA configuration interface busy 2230 status by the configuration function. This option 2231 will require a board or device specific function to 2232 be written. 2233 2234 CONFIG_FPGA_DELAY 2235 2236 If defined, a function that provides delays in the FPGA 2237 configuration driver. 2238 2239 CONFIG_SYS_FPGA_CHECK_CTRLC 2240 Allow Control-C to interrupt FPGA configuration 2241 2242 CONFIG_SYS_FPGA_CHECK_ERROR 2243 2244 Check for configuration errors during FPGA bitfile 2245 loading. For example, abort during Virtex II 2246 configuration if the INIT_B line goes low (which 2247 indicated a CRC error). 2248 2249 CONFIG_SYS_FPGA_WAIT_INIT 2250 2251 Maximum time to wait for the INIT_B line to de-assert 2252 after PROB_B has been de-asserted during a Virtex II 2253 FPGA configuration sequence. The default time is 500 2254 ms. 2255 2256 CONFIG_SYS_FPGA_WAIT_BUSY 2257 2258 Maximum time to wait for BUSY to de-assert during 2259 Virtex II FPGA configuration. The default is 5 ms. 2260 2261 CONFIG_SYS_FPGA_WAIT_CONFIG 2262 2263 Time to wait after FPGA configuration. The default is 2264 200 ms. 2265 2266- Configuration Management: 2267 CONFIG_BUILD_TARGET 2268 2269 Some SoCs need special image types (e.g. U-Boot binary 2270 with a special header) as build targets. By defining 2271 CONFIG_BUILD_TARGET in the SoC / board header, this 2272 special image will be automatically built upon calling 2273 make / buildman. 2274 2275 CONFIG_IDENT_STRING 2276 2277 If defined, this string will be added to the U-Boot 2278 version information (U_BOOT_VERSION) 2279 2280- Vendor Parameter Protection: 2281 2282 U-Boot considers the values of the environment 2283 variables "serial#" (Board Serial Number) and 2284 "ethaddr" (Ethernet Address) to be parameters that 2285 are set once by the board vendor / manufacturer, and 2286 protects these variables from casual modification by 2287 the user. Once set, these variables are read-only, 2288 and write or delete attempts are rejected. You can 2289 change this behaviour: 2290 2291 If CONFIG_ENV_OVERWRITE is #defined in your config 2292 file, the write protection for vendor parameters is 2293 completely disabled. Anybody can change or delete 2294 these parameters. 2295 2296 Alternatively, if you define _both_ an ethaddr in the 2297 default env _and_ CONFIG_OVERWRITE_ETHADDR_ONCE, a default 2298 Ethernet address is installed in the environment, 2299 which can be changed exactly ONCE by the user. [The 2300 serial# is unaffected by this, i. e. it remains 2301 read-only.] 2302 2303 The same can be accomplished in a more flexible way 2304 for any variable by configuring the type of access 2305 to allow for those variables in the ".flags" variable 2306 or define CONFIG_ENV_FLAGS_LIST_STATIC. 2307 2308- Protected RAM: 2309 CONFIG_PRAM 2310 2311 Define this variable to enable the reservation of 2312 "protected RAM", i. e. RAM which is not overwritten 2313 by U-Boot. Define CONFIG_PRAM to hold the number of 2314 kB you want to reserve for pRAM. You can overwrite 2315 this default value by defining an environment 2316 variable "pram" to the number of kB you want to 2317 reserve. Note that the board info structure will 2318 still show the full amount of RAM. If pRAM is 2319 reserved, a new environment variable "mem" will 2320 automatically be defined to hold the amount of 2321 remaining RAM in a form that can be passed as boot 2322 argument to Linux, for instance like that: 2323 2324 setenv bootargs ... mem=\${mem} 2325 saveenv 2326 2327 This way you can tell Linux not to use this memory, 2328 either, which results in a memory region that will 2329 not be affected by reboots. 2330 2331 *WARNING* If your board configuration uses automatic 2332 detection of the RAM size, you must make sure that 2333 this memory test is non-destructive. So far, the 2334 following board configurations are known to be 2335 "pRAM-clean": 2336 2337 IVMS8, IVML24, SPD8xx, 2338 HERMES, IP860, RPXlite, LWMON, 2339 FLAGADM 2340 2341- Access to physical memory region (> 4GB) 2342 Some basic support is provided for operations on memory not 2343 normally accessible to U-Boot - e.g. some architectures 2344 support access to more than 4GB of memory on 32-bit 2345 machines using physical address extension or similar. 2346 Define CONFIG_PHYSMEM to access this basic support, which 2347 currently only supports clearing the memory. 2348 2349- Error Recovery: 2350 CONFIG_PANIC_HANG 2351 2352 Define this variable to stop the system in case of a 2353 fatal error, so that you have to reset it manually. 2354 This is probably NOT a good idea for an embedded 2355 system where you want the system to reboot 2356 automatically as fast as possible, but it may be 2357 useful during development since you can try to debug 2358 the conditions that lead to the situation. 2359 2360 CONFIG_NET_RETRY_COUNT 2361 2362 This variable defines the number of retries for 2363 network operations like ARP, RARP, TFTP, or BOOTP 2364 before giving up the operation. If not defined, a 2365 default value of 5 is used. 2366 2367 CONFIG_ARP_TIMEOUT 2368 2369 Timeout waiting for an ARP reply in milliseconds. 2370 2371 CONFIG_NFS_TIMEOUT 2372 2373 Timeout in milliseconds used in NFS protocol. 2374 If you encounter "ERROR: Cannot umount" in nfs command, 2375 try longer timeout such as 2376 #define CONFIG_NFS_TIMEOUT 10000UL 2377 2378- Command Interpreter: 2379 CONFIG_AUTO_COMPLETE 2380 2381 Enable auto completion of commands using TAB. 2382 2383 CONFIG_SYS_PROMPT_HUSH_PS2 2384 2385 This defines the secondary prompt string, which is 2386 printed when the command interpreter needs more input 2387 to complete a command. Usually "> ". 2388 2389 Note: 2390 2391 In the current implementation, the local variables 2392 space and global environment variables space are 2393 separated. Local variables are those you define by 2394 simply typing `name=value'. To access a local 2395 variable later on, you have write `$name' or 2396 `${name}'; to execute the contents of a variable 2397 directly type `$name' at the command prompt. 2398 2399 Global environment variables are those you use 2400 setenv/printenv to work with. To run a command stored 2401 in such a variable, you need to use the run command, 2402 and you must not use the '$' sign to access them. 2403 2404 To store commands and special characters in a 2405 variable, please use double quotation marks 2406 surrounding the whole text of the variable, instead 2407 of the backslashes before semicolons and special 2408 symbols. 2409 2410- Command Line Editing and History: 2411 CONFIG_CMDLINE_EDITING 2412 2413 Enable editing and History functions for interactive 2414 command line input operations 2415 2416- Command Line PS1/PS2 support: 2417 CONFIG_CMDLINE_PS_SUPPORT 2418 2419 Enable support for changing the command prompt string 2420 at run-time. Only static string is supported so far. 2421 The string is obtained from environment variables PS1 2422 and PS2. 2423 2424- Default Environment: 2425 CONFIG_EXTRA_ENV_SETTINGS 2426 2427 Define this to contain any number of null terminated 2428 strings (variable = value pairs) that will be part of 2429 the default environment compiled into the boot image. 2430 2431 For example, place something like this in your 2432 board's config file: 2433 2434 #define CONFIG_EXTRA_ENV_SETTINGS \ 2435 "myvar1=value1\0" \ 2436 "myvar2=value2\0" 2437 2438 Warning: This method is based on knowledge about the 2439 internal format how the environment is stored by the 2440 U-Boot code. This is NOT an official, exported 2441 interface! Although it is unlikely that this format 2442 will change soon, there is no guarantee either. 2443 You better know what you are doing here. 2444 2445 Note: overly (ab)use of the default environment is 2446 discouraged. Make sure to check other ways to preset 2447 the environment like the "source" command or the 2448 boot command first. 2449 2450 CONFIG_ENV_VARS_UBOOT_CONFIG 2451 2452 Define this in order to add variables describing the 2453 U-Boot build configuration to the default environment. 2454 These will be named arch, cpu, board, vendor, and soc. 2455 2456 Enabling this option will cause the following to be defined: 2457 2458 - CONFIG_SYS_ARCH 2459 - CONFIG_SYS_CPU 2460 - CONFIG_SYS_BOARD 2461 - CONFIG_SYS_VENDOR 2462 - CONFIG_SYS_SOC 2463 2464 CONFIG_ENV_VARS_UBOOT_RUNTIME_CONFIG 2465 2466 Define this in order to add variables describing certain 2467 run-time determined information about the hardware to the 2468 environment. These will be named board_name, board_rev. 2469 2470 CONFIG_DELAY_ENVIRONMENT 2471 2472 Normally the environment is loaded when the board is 2473 initialised so that it is available to U-Boot. This inhibits 2474 that so that the environment is not available until 2475 explicitly loaded later by U-Boot code. With CONFIG_OF_CONTROL 2476 this is instead controlled by the value of 2477 /config/load-environment. 2478 2479- DataFlash Support: 2480 CONFIG_HAS_DATAFLASH 2481 2482 Defining this option enables DataFlash features and 2483 allows to read/write in Dataflash via the standard 2484 commands cp, md... 2485 2486- Serial Flash support 2487 CONFIG_CMD_SF 2488 2489 Defining this option enables SPI flash commands 2490 'sf probe/read/write/erase/update'. 2491 2492 Usage requires an initial 'probe' to define the serial 2493 flash parameters, followed by read/write/erase/update 2494 commands. 2495 2496 The following defaults may be provided by the platform 2497 to handle the common case when only a single serial 2498 flash is present on the system. 2499 2500 CONFIG_SF_DEFAULT_BUS Bus identifier 2501 CONFIG_SF_DEFAULT_CS Chip-select 2502 CONFIG_SF_DEFAULT_MODE (see include/spi.h) 2503 CONFIG_SF_DEFAULT_SPEED in Hz 2504 2505 CONFIG_CMD_SF_TEST 2506 2507 Define this option to include a destructive SPI flash 2508 test ('sf test'). 2509 2510- SystemACE Support: 2511 CONFIG_SYSTEMACE 2512 2513 Adding this option adds support for Xilinx SystemACE 2514 chips attached via some sort of local bus. The address 2515 of the chip must also be defined in the 2516 CONFIG_SYS_SYSTEMACE_BASE macro. For example: 2517 2518 #define CONFIG_SYSTEMACE 2519 #define CONFIG_SYS_SYSTEMACE_BASE 0xf0000000 2520 2521 When SystemACE support is added, the "ace" device type 2522 becomes available to the fat commands, i.e. fatls. 2523 2524- TFTP Fixed UDP Port: 2525 CONFIG_TFTP_PORT 2526 2527 If this is defined, the environment variable tftpsrcp 2528 is used to supply the TFTP UDP source port value. 2529 If tftpsrcp isn't defined, the normal pseudo-random port 2530 number generator is used. 2531 2532 Also, the environment variable tftpdstp is used to supply 2533 the TFTP UDP destination port value. If tftpdstp isn't 2534 defined, the normal port 69 is used. 2535 2536 The purpose for tftpsrcp is to allow a TFTP server to 2537 blindly start the TFTP transfer using the pre-configured 2538 target IP address and UDP port. This has the effect of 2539 "punching through" the (Windows XP) firewall, allowing 2540 the remainder of the TFTP transfer to proceed normally. 2541 A better solution is to properly configure the firewall, 2542 but sometimes that is not allowed. 2543 2544- bootcount support: 2545 CONFIG_BOOTCOUNT_LIMIT 2546 2547 This enables the bootcounter support, see: 2548 http://www.denx.de/wiki/DULG/UBootBootCountLimit 2549 2550 CONFIG_AT91SAM9XE 2551 enable special bootcounter support on at91sam9xe based boards. 2552 CONFIG_SOC_DA8XX 2553 enable special bootcounter support on da850 based boards. 2554 CONFIG_BOOTCOUNT_RAM 2555 enable support for the bootcounter in RAM 2556 CONFIG_BOOTCOUNT_I2C 2557 enable support for the bootcounter on an i2c (like RTC) device. 2558 CONFIG_SYS_I2C_RTC_ADDR = i2c chip address 2559 CONFIG_SYS_BOOTCOUNT_ADDR = i2c addr which is used for 2560 the bootcounter. 2561 CONFIG_BOOTCOUNT_ALEN = address len 2562 2563- Show boot progress: 2564 CONFIG_SHOW_BOOT_PROGRESS 2565 2566 Defining this option allows to add some board- 2567 specific code (calling a user-provided function 2568 "show_boot_progress(int)") that enables you to show 2569 the system's boot progress on some display (for 2570 example, some LED's) on your board. At the moment, 2571 the following checkpoints are implemented: 2572 2573 2574Legacy uImage format: 2575 2576 Arg Where When 2577 1 common/cmd_bootm.c before attempting to boot an image 2578 -1 common/cmd_bootm.c Image header has bad magic number 2579 2 common/cmd_bootm.c Image header has correct magic number 2580 -2 common/cmd_bootm.c Image header has bad checksum 2581 3 common/cmd_bootm.c Image header has correct checksum 2582 -3 common/cmd_bootm.c Image data has bad checksum 2583 4 common/cmd_bootm.c Image data has correct checksum 2584 -4 common/cmd_bootm.c Image is for unsupported architecture 2585 5 common/cmd_bootm.c Architecture check OK 2586 -5 common/cmd_bootm.c Wrong Image Type (not kernel, multi) 2587 6 common/cmd_bootm.c Image Type check OK 2588 -6 common/cmd_bootm.c gunzip uncompression error 2589 -7 common/cmd_bootm.c Unimplemented compression type 2590 7 common/cmd_bootm.c Uncompression OK 2591 8 common/cmd_bootm.c No uncompress/copy overwrite error 2592 -9 common/cmd_bootm.c Unsupported OS (not Linux, BSD, VxWorks, QNX) 2593 2594 9 common/image.c Start initial ramdisk verification 2595 -10 common/image.c Ramdisk header has bad magic number 2596 -11 common/image.c Ramdisk header has bad checksum 2597 10 common/image.c Ramdisk header is OK 2598 -12 common/image.c Ramdisk data has bad checksum 2599 11 common/image.c Ramdisk data has correct checksum 2600 12 common/image.c Ramdisk verification complete, start loading 2601 -13 common/image.c Wrong Image Type (not PPC Linux ramdisk) 2602 13 common/image.c Start multifile image verification 2603 14 common/image.c No initial ramdisk, no multifile, continue. 2604 2605 15 arch/<arch>/lib/bootm.c All preparation done, transferring control to OS 2606 2607 -30 arch/powerpc/lib/board.c Fatal error, hang the system 2608 -31 post/post.c POST test failed, detected by post_output_backlog() 2609 -32 post/post.c POST test failed, detected by post_run_single() 2610 2611 34 common/cmd_doc.c before loading a Image from a DOC device 2612 -35 common/cmd_doc.c Bad usage of "doc" command 2613 35 common/cmd_doc.c correct usage of "doc" command 2614 -36 common/cmd_doc.c No boot device 2615 36 common/cmd_doc.c correct boot device 2616 -37 common/cmd_doc.c Unknown Chip ID on boot device 2617 37 common/cmd_doc.c correct chip ID found, device available 2618 -38 common/cmd_doc.c Read Error on boot device 2619 38 common/cmd_doc.c reading Image header from DOC device OK 2620 -39 common/cmd_doc.c Image header has bad magic number 2621 39 common/cmd_doc.c Image header has correct magic number 2622 -40 common/cmd_doc.c Error reading Image from DOC device 2623 40 common/cmd_doc.c Image header has correct magic number 2624 41 common/cmd_ide.c before loading a Image from a IDE device 2625 -42 common/cmd_ide.c Bad usage of "ide" command 2626 42 common/cmd_ide.c correct usage of "ide" command 2627 -43 common/cmd_ide.c No boot device 2628 43 common/cmd_ide.c boot device found 2629 -44 common/cmd_ide.c Device not available 2630 44 common/cmd_ide.c Device available 2631 -45 common/cmd_ide.c wrong partition selected 2632 45 common/cmd_ide.c partition selected 2633 -46 common/cmd_ide.c Unknown partition table 2634 46 common/cmd_ide.c valid partition table found 2635 -47 common/cmd_ide.c Invalid partition type 2636 47 common/cmd_ide.c correct partition type 2637 -48 common/cmd_ide.c Error reading Image Header on boot device 2638 48 common/cmd_ide.c reading Image Header from IDE device OK 2639 -49 common/cmd_ide.c Image header has bad magic number 2640 49 common/cmd_ide.c Image header has correct magic number 2641 -50 common/cmd_ide.c Image header has bad checksum 2642 50 common/cmd_ide.c Image header has correct checksum 2643 -51 common/cmd_ide.c Error reading Image from IDE device 2644 51 common/cmd_ide.c reading Image from IDE device OK 2645 52 common/cmd_nand.c before loading a Image from a NAND device 2646 -53 common/cmd_nand.c Bad usage of "nand" command 2647 53 common/cmd_nand.c correct usage of "nand" command 2648 -54 common/cmd_nand.c No boot device 2649 54 common/cmd_nand.c boot device found 2650 -55 common/cmd_nand.c Unknown Chip ID on boot device 2651 55 common/cmd_nand.c correct chip ID found, device available 2652 -56 common/cmd_nand.c Error reading Image Header on boot device 2653 56 common/cmd_nand.c reading Image Header from NAND device OK 2654 -57 common/cmd_nand.c Image header has bad magic number 2655 57 common/cmd_nand.c Image header has correct magic number 2656 -58 common/cmd_nand.c Error reading Image from NAND device 2657 58 common/cmd_nand.c reading Image from NAND device OK 2658 2659 -60 common/env_common.c Environment has a bad CRC, using default 2660 2661 64 net/eth.c starting with Ethernet configuration. 2662 -64 net/eth.c no Ethernet found. 2663 65 net/eth.c Ethernet found. 2664 2665 -80 common/cmd_net.c usage wrong 2666 80 common/cmd_net.c before calling net_loop() 2667 -81 common/cmd_net.c some error in net_loop() occurred 2668 81 common/cmd_net.c net_loop() back without error 2669 -82 common/cmd_net.c size == 0 (File with size 0 loaded) 2670 82 common/cmd_net.c trying automatic boot 2671 83 common/cmd_net.c running "source" command 2672 -83 common/cmd_net.c some error in automatic boot or "source" command 2673 84 common/cmd_net.c end without errors 2674 2675FIT uImage format: 2676 2677 Arg Where When 2678 100 common/cmd_bootm.c Kernel FIT Image has correct format 2679 -100 common/cmd_bootm.c Kernel FIT Image has incorrect format 2680 101 common/cmd_bootm.c No Kernel subimage unit name, using configuration 2681 -101 common/cmd_bootm.c Can't get configuration for kernel subimage 2682 102 common/cmd_bootm.c Kernel unit name specified 2683 -103 common/cmd_bootm.c Can't get kernel subimage node offset 2684 103 common/cmd_bootm.c Found configuration node 2685 104 common/cmd_bootm.c Got kernel subimage node offset 2686 -104 common/cmd_bootm.c Kernel subimage hash verification failed 2687 105 common/cmd_bootm.c Kernel subimage hash verification OK 2688 -105 common/cmd_bootm.c Kernel subimage is for unsupported architecture 2689 106 common/cmd_bootm.c Architecture check OK 2690 -106 common/cmd_bootm.c Kernel subimage has wrong type 2691 107 common/cmd_bootm.c Kernel subimage type OK 2692 -107 common/cmd_bootm.c Can't get kernel subimage data/size 2693 108 common/cmd_bootm.c Got kernel subimage data/size 2694 -108 common/cmd_bootm.c Wrong image type (not legacy, FIT) 2695 -109 common/cmd_bootm.c Can't get kernel subimage type 2696 -110 common/cmd_bootm.c Can't get kernel subimage comp 2697 -111 common/cmd_bootm.c Can't get kernel subimage os 2698 -112 common/cmd_bootm.c Can't get kernel subimage load address 2699 -113 common/cmd_bootm.c Image uncompress/copy overwrite error 2700 2701 120 common/image.c Start initial ramdisk verification 2702 -120 common/image.c Ramdisk FIT image has incorrect format 2703 121 common/image.c Ramdisk FIT image has correct format 2704 122 common/image.c No ramdisk subimage unit name, using configuration 2705 -122 common/image.c Can't get configuration for ramdisk subimage 2706 123 common/image.c Ramdisk unit name specified 2707 -124 common/image.c Can't get ramdisk subimage node offset 2708 125 common/image.c Got ramdisk subimage node offset 2709 -125 common/image.c Ramdisk subimage hash verification failed 2710 126 common/image.c Ramdisk subimage hash verification OK 2711 -126 common/image.c Ramdisk subimage for unsupported architecture 2712 127 common/image.c Architecture check OK 2713 -127 common/image.c Can't get ramdisk subimage data/size 2714 128 common/image.c Got ramdisk subimage data/size 2715 129 common/image.c Can't get ramdisk load address 2716 -129 common/image.c Got ramdisk load address 2717 2718 -130 common/cmd_doc.c Incorrect FIT image format 2719 131 common/cmd_doc.c FIT image format OK 2720 2721 -140 common/cmd_ide.c Incorrect FIT image format 2722 141 common/cmd_ide.c FIT image format OK 2723 2724 -150 common/cmd_nand.c Incorrect FIT image format 2725 151 common/cmd_nand.c FIT image format OK 2726 2727- legacy image format: 2728 CONFIG_IMAGE_FORMAT_LEGACY 2729 enables the legacy image format support in U-Boot. 2730 2731 Default: 2732 enabled if CONFIG_FIT_SIGNATURE is not defined. 2733 2734 CONFIG_DISABLE_IMAGE_LEGACY 2735 disable the legacy image format 2736 2737 This define is introduced, as the legacy image format is 2738 enabled per default for backward compatibility. 2739 2740- Standalone program support: 2741 CONFIG_STANDALONE_LOAD_ADDR 2742 2743 This option defines a board specific value for the 2744 address where standalone program gets loaded, thus 2745 overwriting the architecture dependent default 2746 settings. 2747 2748- Frame Buffer Address: 2749 CONFIG_FB_ADDR 2750 2751 Define CONFIG_FB_ADDR if you want to use specific 2752 address for frame buffer. This is typically the case 2753 when using a graphics controller has separate video 2754 memory. U-Boot will then place the frame buffer at 2755 the given address instead of dynamically reserving it 2756 in system RAM by calling lcd_setmem(), which grabs 2757 the memory for the frame buffer depending on the 2758 configured panel size. 2759 2760 Please see board_init_f function. 2761 2762- Automatic software updates via TFTP server 2763 CONFIG_UPDATE_TFTP 2764 CONFIG_UPDATE_TFTP_CNT_MAX 2765 CONFIG_UPDATE_TFTP_MSEC_MAX 2766 2767 These options enable and control the auto-update feature; 2768 for a more detailed description refer to doc/README.update. 2769 2770- MTD Support (mtdparts command, UBI support) 2771 CONFIG_MTD_DEVICE 2772 2773 Adds the MTD device infrastructure from the Linux kernel. 2774 Needed for mtdparts command support. 2775 2776 CONFIG_MTD_PARTITIONS 2777 2778 Adds the MTD partitioning infrastructure from the Linux 2779 kernel. Needed for UBI support. 2780 2781- UBI support 2782 CONFIG_UBI_SILENCE_MSG 2783 2784 Make the verbose messages from UBI stop printing. This leaves 2785 warnings and errors enabled. 2786 2787 2788 CONFIG_MTD_UBI_WL_THRESHOLD 2789 This parameter defines the maximum difference between the highest 2790 erase counter value and the lowest erase counter value of eraseblocks 2791 of UBI devices. When this threshold is exceeded, UBI starts performing 2792 wear leveling by means of moving data from eraseblock with low erase 2793 counter to eraseblocks with high erase counter. 2794 2795 The default value should be OK for SLC NAND flashes, NOR flashes and 2796 other flashes which have eraseblock life-cycle 100000 or more. 2797 However, in case of MLC NAND flashes which typically have eraseblock 2798 life-cycle less than 10000, the threshold should be lessened (e.g., 2799 to 128 or 256, although it does not have to be power of 2). 2800 2801 default: 4096 2802 2803 CONFIG_MTD_UBI_BEB_LIMIT 2804 This option specifies the maximum bad physical eraseblocks UBI 2805 expects on the MTD device (per 1024 eraseblocks). If the 2806 underlying flash does not admit of bad eraseblocks (e.g. NOR 2807 flash), this value is ignored. 2808 2809 NAND datasheets often specify the minimum and maximum NVM 2810 (Number of Valid Blocks) for the flashes' endurance lifetime. 2811 The maximum expected bad eraseblocks per 1024 eraseblocks 2812 then can be calculated as "1024 * (1 - MinNVB / MaxNVB)", 2813 which gives 20 for most NANDs (MaxNVB is basically the total 2814 count of eraseblocks on the chip). 2815 2816 To put it differently, if this value is 20, UBI will try to 2817 reserve about 1.9% of physical eraseblocks for bad blocks 2818 handling. And that will be 1.9% of eraseblocks on the entire 2819 NAND chip, not just the MTD partition UBI attaches. This means 2820 that if you have, say, a NAND flash chip admits maximum 40 bad 2821 eraseblocks, and it is split on two MTD partitions of the same 2822 size, UBI will reserve 40 eraseblocks when attaching a 2823 partition. 2824 2825 default: 20 2826 2827 CONFIG_MTD_UBI_FASTMAP 2828 Fastmap is a mechanism which allows attaching an UBI device 2829 in nearly constant time. Instead of scanning the whole MTD device it 2830 only has to locate a checkpoint (called fastmap) on the device. 2831 The on-flash fastmap contains all information needed to attach 2832 the device. Using fastmap makes only sense on large devices where 2833 attaching by scanning takes long. UBI will not automatically install 2834 a fastmap on old images, but you can set the UBI parameter 2835 CONFIG_MTD_UBI_FASTMAP_AUTOCONVERT to 1 if you want so. Please note 2836 that fastmap-enabled images are still usable with UBI implementations 2837 without fastmap support. On typical flash devices the whole fastmap 2838 fits into one PEB. UBI will reserve PEBs to hold two fastmaps. 2839 2840 CONFIG_MTD_UBI_FASTMAP_AUTOCONVERT 2841 Set this parameter to enable fastmap automatically on images 2842 without a fastmap. 2843 default: 0 2844 2845 CONFIG_MTD_UBI_FM_DEBUG 2846 Enable UBI fastmap debug 2847 default: 0 2848 2849- UBIFS support 2850 CONFIG_UBIFS_SILENCE_MSG 2851 2852 Make the verbose messages from UBIFS stop printing. This leaves 2853 warnings and errors enabled. 2854 2855- SPL framework 2856 CONFIG_SPL 2857 Enable building of SPL globally. 2858 2859 CONFIG_SPL_LDSCRIPT 2860 LDSCRIPT for linking the SPL binary. 2861 2862 CONFIG_SPL_MAX_FOOTPRINT 2863 Maximum size in memory allocated to the SPL, BSS included. 2864 When defined, the linker checks that the actual memory 2865 used by SPL from _start to __bss_end does not exceed it. 2866 CONFIG_SPL_MAX_FOOTPRINT and CONFIG_SPL_BSS_MAX_SIZE 2867 must not be both defined at the same time. 2868 2869 CONFIG_SPL_MAX_SIZE 2870 Maximum size of the SPL image (text, data, rodata, and 2871 linker lists sections), BSS excluded. 2872 When defined, the linker checks that the actual size does 2873 not exceed it. 2874 2875 CONFIG_SPL_TEXT_BASE 2876 TEXT_BASE for linking the SPL binary. 2877 2878 CONFIG_SPL_RELOC_TEXT_BASE 2879 Address to relocate to. If unspecified, this is equal to 2880 CONFIG_SPL_TEXT_BASE (i.e. no relocation is done). 2881 2882 CONFIG_SPL_BSS_START_ADDR 2883 Link address for the BSS within the SPL binary. 2884 2885 CONFIG_SPL_BSS_MAX_SIZE 2886 Maximum size in memory allocated to the SPL BSS. 2887 When defined, the linker checks that the actual memory used 2888 by SPL from __bss_start to __bss_end does not exceed it. 2889 CONFIG_SPL_MAX_FOOTPRINT and CONFIG_SPL_BSS_MAX_SIZE 2890 must not be both defined at the same time. 2891 2892 CONFIG_SPL_STACK 2893 Adress of the start of the stack SPL will use 2894 2895 CONFIG_SPL_PANIC_ON_RAW_IMAGE 2896 When defined, SPL will panic() if the image it has 2897 loaded does not have a signature. 2898 Defining this is useful when code which loads images 2899 in SPL cannot guarantee that absolutely all read errors 2900 will be caught. 2901 An example is the LPC32XX MLC NAND driver, which will 2902 consider that a completely unreadable NAND block is bad, 2903 and thus should be skipped silently. 2904 2905 CONFIG_SPL_RELOC_STACK 2906 Adress of the start of the stack SPL will use after 2907 relocation. If unspecified, this is equal to 2908 CONFIG_SPL_STACK. 2909 2910 CONFIG_SYS_SPL_MALLOC_START 2911 Starting address of the malloc pool used in SPL. 2912 When this option is set the full malloc is used in SPL and 2913 it is set up by spl_init() and before that, the simple malloc() 2914 can be used if CONFIG_SYS_MALLOC_F is defined. 2915 2916 CONFIG_SYS_SPL_MALLOC_SIZE 2917 The size of the malloc pool used in SPL. 2918 2919 CONFIG_SPL_FRAMEWORK 2920 Enable the SPL framework under common/. This framework 2921 supports MMC, NAND and YMODEM loading of U-Boot and NAND 2922 NAND loading of the Linux Kernel. 2923 2924 CONFIG_SPL_OS_BOOT 2925 Enable booting directly to an OS from SPL. 2926 See also: doc/README.falcon 2927 2928 CONFIG_SPL_DISPLAY_PRINT 2929 For ARM, enable an optional function to print more information 2930 about the running system. 2931 2932 CONFIG_SPL_INIT_MINIMAL 2933 Arch init code should be built for a very small image 2934 2935 CONFIG_SYS_MMCSD_RAW_MODE_U_BOOT_PARTITION 2936 Partition on the MMC to load U-Boot from when the MMC is being 2937 used in raw mode 2938 2939 CONFIG_SYS_MMCSD_RAW_MODE_KERNEL_SECTOR 2940 Sector to load kernel uImage from when MMC is being 2941 used in raw mode (for Falcon mode) 2942 2943 CONFIG_SYS_MMCSD_RAW_MODE_ARGS_SECTOR, 2944 CONFIG_SYS_MMCSD_RAW_MODE_ARGS_SECTORS 2945 Sector and number of sectors to load kernel argument 2946 parameters from when MMC is being used in raw mode 2947 (for falcon mode) 2948 2949 CONFIG_SYS_MMCSD_FS_BOOT_PARTITION 2950 Partition on the MMC to load U-Boot from when the MMC is being 2951 used in fs mode 2952 2953 CONFIG_SPL_FS_LOAD_PAYLOAD_NAME 2954 Filename to read to load U-Boot when reading from filesystem 2955 2956 CONFIG_SPL_FS_LOAD_KERNEL_NAME 2957 Filename to read to load kernel uImage when reading 2958 from filesystem (for Falcon mode) 2959 2960 CONFIG_SPL_FS_LOAD_ARGS_NAME 2961 Filename to read to load kernel argument parameters 2962 when reading from filesystem (for Falcon mode) 2963 2964 CONFIG_SPL_MPC83XX_WAIT_FOR_NAND 2965 Set this for NAND SPL on PPC mpc83xx targets, so that 2966 start.S waits for the rest of the SPL to load before 2967 continuing (the hardware starts execution after just 2968 loading the first page rather than the full 4K). 2969 2970 CONFIG_SPL_SKIP_RELOCATE 2971 Avoid SPL relocation 2972 2973 CONFIG_SPL_NAND_BASE 2974 Include nand_base.c in the SPL. Requires 2975 CONFIG_SPL_NAND_DRIVERS. 2976 2977 CONFIG_SPL_NAND_DRIVERS 2978 SPL uses normal NAND drivers, not minimal drivers. 2979 2980 CONFIG_SPL_NAND_ECC 2981 Include standard software ECC in the SPL 2982 2983 CONFIG_SPL_NAND_SIMPLE 2984 Support for NAND boot using simple NAND drivers that 2985 expose the cmd_ctrl() interface. 2986 2987 CONFIG_SPL_UBI 2988 Support for a lightweight UBI (fastmap) scanner and 2989 loader 2990 2991 CONFIG_SPL_NAND_RAW_ONLY 2992 Support to boot only raw u-boot.bin images. Use this only 2993 if you need to save space. 2994 2995 CONFIG_SPL_COMMON_INIT_DDR 2996 Set for common ddr init with serial presence detect in 2997 SPL binary. 2998 2999 CONFIG_SYS_NAND_5_ADDR_CYCLE, CONFIG_SYS_NAND_PAGE_COUNT, 3000 CONFIG_SYS_NAND_PAGE_SIZE, CONFIG_SYS_NAND_OOBSIZE, 3001 CONFIG_SYS_NAND_BLOCK_SIZE, CONFIG_SYS_NAND_BAD_BLOCK_POS, 3002 CONFIG_SYS_NAND_ECCPOS, CONFIG_SYS_NAND_ECCSIZE, 3003 CONFIG_SYS_NAND_ECCBYTES 3004 Defines the size and behavior of the NAND that SPL uses 3005 to read U-Boot 3006 3007 CONFIG_SPL_NAND_BOOT 3008 Add support NAND boot 3009 3010 CONFIG_SYS_NAND_U_BOOT_OFFS 3011 Location in NAND to read U-Boot from 3012 3013 CONFIG_SYS_NAND_U_BOOT_DST 3014 Location in memory to load U-Boot to 3015 3016 CONFIG_SYS_NAND_U_BOOT_SIZE 3017 Size of image to load 3018 3019 CONFIG_SYS_NAND_U_BOOT_START 3020 Entry point in loaded image to jump to 3021 3022 CONFIG_SYS_NAND_HW_ECC_OOBFIRST 3023 Define this if you need to first read the OOB and then the 3024 data. This is used, for example, on davinci platforms. 3025 3026 CONFIG_SPL_OMAP3_ID_NAND 3027 Support for an OMAP3-specific set of functions to return the 3028 ID and MFR of the first attached NAND chip, if present. 3029 3030 CONFIG_SPL_RAM_DEVICE 3031 Support for running image already present in ram, in SPL binary 3032 3033 CONFIG_SPL_PAD_TO 3034 Image offset to which the SPL should be padded before appending 3035 the SPL payload. By default, this is defined as 3036 CONFIG_SPL_MAX_SIZE, or 0 if CONFIG_SPL_MAX_SIZE is undefined. 3037 CONFIG_SPL_PAD_TO must be either 0, meaning to append the SPL 3038 payload without any padding, or >= CONFIG_SPL_MAX_SIZE. 3039 3040 CONFIG_SPL_TARGET 3041 Final target image containing SPL and payload. Some SPLs 3042 use an arch-specific makefile fragment instead, for 3043 example if more than one image needs to be produced. 3044 3045 CONFIG_FIT_SPL_PRINT 3046 Printing information about a FIT image adds quite a bit of 3047 code to SPL. So this is normally disabled in SPL. Use this 3048 option to re-enable it. This will affect the output of the 3049 bootm command when booting a FIT image. 3050 3051- TPL framework 3052 CONFIG_TPL 3053 Enable building of TPL globally. 3054 3055 CONFIG_TPL_PAD_TO 3056 Image offset to which the TPL should be padded before appending 3057 the TPL payload. By default, this is defined as 3058 CONFIG_SPL_MAX_SIZE, or 0 if CONFIG_SPL_MAX_SIZE is undefined. 3059 CONFIG_SPL_PAD_TO must be either 0, meaning to append the SPL 3060 payload without any padding, or >= CONFIG_SPL_MAX_SIZE. 3061 3062- Interrupt support (PPC): 3063 3064 There are common interrupt_init() and timer_interrupt() 3065 for all PPC archs. interrupt_init() calls interrupt_init_cpu() 3066 for CPU specific initialization. interrupt_init_cpu() 3067 should set decrementer_count to appropriate value. If 3068 CPU resets decrementer automatically after interrupt 3069 (ppc4xx) it should set decrementer_count to zero. 3070 timer_interrupt() calls timer_interrupt_cpu() for CPU 3071 specific handling. If board has watchdog / status_led 3072 / other_activity_monitor it works automatically from 3073 general timer_interrupt(). 3074 3075 3076Board initialization settings: 3077------------------------------ 3078 3079During Initialization u-boot calls a number of board specific functions 3080to allow the preparation of board specific prerequisites, e.g. pin setup 3081before drivers are initialized. To enable these callbacks the 3082following configuration macros have to be defined. Currently this is 3083architecture specific, so please check arch/your_architecture/lib/board.c 3084typically in board_init_f() and board_init_r(). 3085 3086- CONFIG_BOARD_EARLY_INIT_F: Call board_early_init_f() 3087- CONFIG_BOARD_EARLY_INIT_R: Call board_early_init_r() 3088- CONFIG_BOARD_LATE_INIT: Call board_late_init() 3089- CONFIG_BOARD_POSTCLK_INIT: Call board_postclk_init() 3090 3091Configuration Settings: 3092----------------------- 3093 3094- CONFIG_SYS_SUPPORT_64BIT_DATA: Defined automatically if compiled as 64-bit. 3095 Optionally it can be defined to support 64-bit memory commands. 3096 3097- CONFIG_SYS_LONGHELP: Defined when you want long help messages included; 3098 undefine this when you're short of memory. 3099 3100- CONFIG_SYS_HELP_CMD_WIDTH: Defined when you want to override the default 3101 width of the commands listed in the 'help' command output. 3102 3103- CONFIG_SYS_PROMPT: This is what U-Boot prints on the console to 3104 prompt for user input. 3105 3106- CONFIG_SYS_CBSIZE: Buffer size for input from the Console 3107 3108- CONFIG_SYS_PBSIZE: Buffer size for Console output 3109 3110- CONFIG_SYS_MAXARGS: max. Number of arguments accepted for monitor commands 3111 3112- CONFIG_SYS_BARGSIZE: Buffer size for Boot Arguments which are passed to 3113 the application (usually a Linux kernel) when it is 3114 booted 3115 3116- CONFIG_SYS_BAUDRATE_TABLE: 3117 List of legal baudrate settings for this board. 3118 3119- CONFIG_SYS_MEMTEST_START, CONFIG_SYS_MEMTEST_END: 3120 Begin and End addresses of the area used by the 3121 simple memory test. 3122 3123- CONFIG_SYS_ALT_MEMTEST: 3124 Enable an alternate, more extensive memory test. 3125 3126- CONFIG_SYS_MEMTEST_SCRATCH: 3127 Scratch address used by the alternate memory test 3128 You only need to set this if address zero isn't writeable 3129 3130- CONFIG_SYS_MEM_RESERVE_SECURE 3131 Only implemented for ARMv8 for now. 3132 If defined, the size of CONFIG_SYS_MEM_RESERVE_SECURE memory 3133 is substracted from total RAM and won't be reported to OS. 3134 This memory can be used as secure memory. A variable 3135 gd->arch.secure_ram is used to track the location. In systems 3136 the RAM base is not zero, or RAM is divided into banks, 3137 this variable needs to be recalcuated to get the address. 3138 3139- CONFIG_SYS_MEM_TOP_HIDE: 3140 If CONFIG_SYS_MEM_TOP_HIDE is defined in the board config header, 3141 this specified memory area will get subtracted from the top 3142 (end) of RAM and won't get "touched" at all by U-Boot. By 3143 fixing up gd->ram_size the Linux kernel should gets passed 3144 the now "corrected" memory size and won't touch it either. 3145 This should work for arch/ppc and arch/powerpc. Only Linux 3146 board ports in arch/powerpc with bootwrapper support that 3147 recalculate the memory size from the SDRAM controller setup 3148 will have to get fixed in Linux additionally. 3149 3150 This option can be used as a workaround for the 440EPx/GRx 3151 CHIP 11 errata where the last 256 bytes in SDRAM shouldn't 3152 be touched. 3153 3154 WARNING: Please make sure that this value is a multiple of 3155 the Linux page size (normally 4k). If this is not the case, 3156 then the end address of the Linux memory will be located at a 3157 non page size aligned address and this could cause major 3158 problems. 3159 3160- CONFIG_SYS_LOADS_BAUD_CHANGE: 3161 Enable temporary baudrate change while serial download 3162 3163- CONFIG_SYS_SDRAM_BASE: 3164 Physical start address of SDRAM. _Must_ be 0 here. 3165 3166- CONFIG_SYS_FLASH_BASE: 3167 Physical start address of Flash memory. 3168 3169- CONFIG_SYS_MONITOR_BASE: 3170 Physical start address of boot monitor code (set by 3171 make config files to be same as the text base address 3172 (CONFIG_SYS_TEXT_BASE) used when linking) - same as 3173 CONFIG_SYS_FLASH_BASE when booting from flash. 3174 3175- CONFIG_SYS_MONITOR_LEN: 3176 Size of memory reserved for monitor code, used to 3177 determine _at_compile_time_ (!) if the environment is 3178 embedded within the U-Boot image, or in a separate 3179 flash sector. 3180 3181- CONFIG_SYS_MALLOC_LEN: 3182 Size of DRAM reserved for malloc() use. 3183 3184- CONFIG_SYS_MALLOC_F_LEN 3185 Size of the malloc() pool for use before relocation. If 3186 this is defined, then a very simple malloc() implementation 3187 will become available before relocation. The address is just 3188 below the global data, and the stack is moved down to make 3189 space. 3190 3191 This feature allocates regions with increasing addresses 3192 within the region. calloc() is supported, but realloc() 3193 is not available. free() is supported but does nothing. 3194 The memory will be freed (or in fact just forgotten) when 3195 U-Boot relocates itself. 3196 3197- CONFIG_SYS_MALLOC_SIMPLE 3198 Provides a simple and small malloc() and calloc() for those 3199 boards which do not use the full malloc in SPL (which is 3200 enabled with CONFIG_SYS_SPL_MALLOC_START). 3201 3202- CONFIG_SYS_NONCACHED_MEMORY: 3203 Size of non-cached memory area. This area of memory will be 3204 typically located right below the malloc() area and mapped 3205 uncached in the MMU. This is useful for drivers that would 3206 otherwise require a lot of explicit cache maintenance. For 3207 some drivers it's also impossible to properly maintain the 3208 cache. For example if the regions that need to be flushed 3209 are not a multiple of the cache-line size, *and* padding 3210 cannot be allocated between the regions to align them (i.e. 3211 if the HW requires a contiguous array of regions, and the 3212 size of each region is not cache-aligned), then a flush of 3213 one region may result in overwriting data that hardware has 3214 written to another region in the same cache-line. This can 3215 happen for example in network drivers where descriptors for 3216 buffers are typically smaller than the CPU cache-line (e.g. 3217 16 bytes vs. 32 or 64 bytes). 3218 3219 Non-cached memory is only supported on 32-bit ARM at present. 3220 3221- CONFIG_SYS_BOOTM_LEN: 3222 Normally compressed uImages are limited to an 3223 uncompressed size of 8 MBytes. If this is not enough, 3224 you can define CONFIG_SYS_BOOTM_LEN in your board config file 3225 to adjust this setting to your needs. 3226 3227- CONFIG_SYS_BOOTMAPSZ: 3228 Maximum size of memory mapped by the startup code of 3229 the Linux kernel; all data that must be processed by 3230 the Linux kernel (bd_info, boot arguments, FDT blob if 3231 used) must be put below this limit, unless "bootm_low" 3232 environment variable is defined and non-zero. In such case 3233 all data for the Linux kernel must be between "bootm_low" 3234 and "bootm_low" + CONFIG_SYS_BOOTMAPSZ. The environment 3235 variable "bootm_mapsize" will override the value of 3236 CONFIG_SYS_BOOTMAPSZ. If CONFIG_SYS_BOOTMAPSZ is undefined, 3237 then the value in "bootm_size" will be used instead. 3238 3239- CONFIG_SYS_BOOT_RAMDISK_HIGH: 3240 Enable initrd_high functionality. If defined then the 3241 initrd_high feature is enabled and the bootm ramdisk subcommand 3242 is enabled. 3243 3244- CONFIG_SYS_BOOT_GET_CMDLINE: 3245 Enables allocating and saving kernel cmdline in space between 3246 "bootm_low" and "bootm_low" + BOOTMAPSZ. 3247 3248- CONFIG_SYS_BOOT_GET_KBD: 3249 Enables allocating and saving a kernel copy of the bd_info in 3250 space between "bootm_low" and "bootm_low" + BOOTMAPSZ. 3251 3252- CONFIG_SYS_MAX_FLASH_BANKS: 3253 Max number of Flash memory banks 3254 3255- CONFIG_SYS_MAX_FLASH_SECT: 3256 Max number of sectors on a Flash chip 3257 3258- CONFIG_SYS_FLASH_ERASE_TOUT: 3259 Timeout for Flash erase operations (in ms) 3260 3261- CONFIG_SYS_FLASH_WRITE_TOUT: 3262 Timeout for Flash write operations (in ms) 3263 3264- CONFIG_SYS_FLASH_LOCK_TOUT 3265 Timeout for Flash set sector lock bit operation (in ms) 3266 3267- CONFIG_SYS_FLASH_UNLOCK_TOUT 3268 Timeout for Flash clear lock bits operation (in ms) 3269 3270- CONFIG_SYS_FLASH_PROTECTION 3271 If defined, hardware flash sectors protection is used 3272 instead of U-Boot software protection. 3273 3274- CONFIG_SYS_DIRECT_FLASH_TFTP: 3275 3276 Enable TFTP transfers directly to flash memory; 3277 without this option such a download has to be 3278 performed in two steps: (1) download to RAM, and (2) 3279 copy from RAM to flash. 3280 3281 The two-step approach is usually more reliable, since 3282 you can check if the download worked before you erase 3283 the flash, but in some situations (when system RAM is 3284 too limited to allow for a temporary copy of the 3285 downloaded image) this option may be very useful. 3286 3287- CONFIG_SYS_FLASH_CFI: 3288 Define if the flash driver uses extra elements in the 3289 common flash structure for storing flash geometry. 3290 3291- CONFIG_FLASH_CFI_DRIVER 3292 This option also enables the building of the cfi_flash driver 3293 in the drivers directory 3294 3295- CONFIG_FLASH_CFI_MTD 3296 This option enables the building of the cfi_mtd driver 3297 in the drivers directory. The driver exports CFI flash 3298 to the MTD layer. 3299 3300- CONFIG_SYS_FLASH_USE_BUFFER_WRITE 3301 Use buffered writes to flash. 3302 3303- CONFIG_FLASH_SPANSION_S29WS_N 3304 s29ws-n MirrorBit flash has non-standard addresses for buffered 3305 write commands. 3306 3307- CONFIG_SYS_FLASH_QUIET_TEST 3308 If this option is defined, the common CFI flash doesn't 3309 print it's warning upon not recognized FLASH banks. This 3310 is useful, if some of the configured banks are only 3311 optionally available. 3312 3313- CONFIG_FLASH_SHOW_PROGRESS 3314 If defined (must be an integer), print out countdown 3315 digits and dots. Recommended value: 45 (9..1) for 80 3316 column displays, 15 (3..1) for 40 column displays. 3317 3318- CONFIG_FLASH_VERIFY 3319 If defined, the content of the flash (destination) is compared 3320 against the source after the write operation. An error message 3321 will be printed when the contents are not identical. 3322 Please note that this option is useless in nearly all cases, 3323 since such flash programming errors usually are detected earlier 3324 while unprotecting/erasing/programming. Please only enable 3325 this option if you really know what you are doing. 3326 3327- CONFIG_SYS_RX_ETH_BUFFER: 3328 Defines the number of Ethernet receive buffers. On some 3329 Ethernet controllers it is recommended to set this value 3330 to 8 or even higher (EEPRO100 or 405 EMAC), since all 3331 buffers can be full shortly after enabling the interface 3332 on high Ethernet traffic. 3333 Defaults to 4 if not defined. 3334 3335- CONFIG_ENV_MAX_ENTRIES 3336 3337 Maximum number of entries in the hash table that is used 3338 internally to store the environment settings. The default 3339 setting is supposed to be generous and should work in most 3340 cases. This setting can be used to tune behaviour; see 3341 lib/hashtable.c for details. 3342 3343- CONFIG_ENV_FLAGS_LIST_DEFAULT 3344- CONFIG_ENV_FLAGS_LIST_STATIC 3345 Enable validation of the values given to environment variables when 3346 calling env set. Variables can be restricted to only decimal, 3347 hexadecimal, or boolean. If CONFIG_CMD_NET is also defined, 3348 the variables can also be restricted to IP address or MAC address. 3349 3350 The format of the list is: 3351 type_attribute = [s|d|x|b|i|m] 3352 access_attribute = [a|r|o|c] 3353 attributes = type_attribute[access_attribute] 3354 entry = variable_name[:attributes] 3355 list = entry[,list] 3356 3357 The type attributes are: 3358 s - String (default) 3359 d - Decimal 3360 x - Hexadecimal 3361 b - Boolean ([1yYtT|0nNfF]) 3362 i - IP address 3363 m - MAC address 3364 3365 The access attributes are: 3366 a - Any (default) 3367 r - Read-only 3368 o - Write-once 3369 c - Change-default 3370 3371 - CONFIG_ENV_FLAGS_LIST_DEFAULT 3372 Define this to a list (string) to define the ".flags" 3373 environment variable in the default or embedded environment. 3374 3375 - CONFIG_ENV_FLAGS_LIST_STATIC 3376 Define this to a list (string) to define validation that 3377 should be done if an entry is not found in the ".flags" 3378 environment variable. To override a setting in the static 3379 list, simply add an entry for the same variable name to the 3380 ".flags" variable. 3381 3382 If CONFIG_REGEX is defined, the variable_name above is evaluated as a 3383 regular expression. This allows multiple variables to define the same 3384 flags without explicitly listing them for each variable. 3385 3386- CONFIG_ENV_ACCESS_IGNORE_FORCE 3387 If defined, don't allow the -f switch to env set override variable 3388 access flags. 3389 3390- CONFIG_USE_STDINT 3391 If stdint.h is available with your toolchain you can define this 3392 option to enable it. You can provide option 'USE_STDINT=1' when 3393 building U-Boot to enable this. 3394 3395The following definitions that deal with the placement and management 3396of environment data (variable area); in general, we support the 3397following configurations: 3398 3399- CONFIG_BUILD_ENVCRC: 3400 3401 Builds up envcrc with the target environment so that external utils 3402 may easily extract it and embed it in final U-Boot images. 3403 3404BE CAREFUL! The first access to the environment happens quite early 3405in U-Boot initialization (when we try to get the setting of for the 3406console baudrate). You *MUST* have mapped your NVRAM area then, or 3407U-Boot will hang. 3408 3409Please note that even with NVRAM we still use a copy of the 3410environment in RAM: we could work on NVRAM directly, but we want to 3411keep settings there always unmodified except somebody uses "saveenv" 3412to save the current settings. 3413 3414BE CAREFUL! For some special cases, the local device can not use 3415"saveenv" command. For example, the local device will get the 3416environment stored in a remote NOR flash by SRIO or PCIE link, 3417but it can not erase, write this NOR flash by SRIO or PCIE interface. 3418 3419- CONFIG_NAND_ENV_DST 3420 3421 Defines address in RAM to which the nand_spl code should copy the 3422 environment. If redundant environment is used, it will be copied to 3423 CONFIG_NAND_ENV_DST + CONFIG_ENV_SIZE. 3424 3425Please note that the environment is read-only until the monitor 3426has been relocated to RAM and a RAM copy of the environment has been 3427created; also, when using EEPROM you will have to use getenv_f() 3428until then to read environment variables. 3429 3430The environment is protected by a CRC32 checksum. Before the monitor 3431is relocated into RAM, as a result of a bad CRC you will be working 3432with the compiled-in default environment - *silently*!!! [This is 3433necessary, because the first environment variable we need is the 3434"baudrate" setting for the console - if we have a bad CRC, we don't 3435have any device yet where we could complain.] 3436 3437Note: once the monitor has been relocated, then it will complain if 3438the default environment is used; a new CRC is computed as soon as you 3439use the "saveenv" command to store a valid environment. 3440 3441- CONFIG_SYS_FAULT_ECHO_LINK_DOWN: 3442 Echo the inverted Ethernet link state to the fault LED. 3443 3444 Note: If this option is active, then CONFIG_SYS_FAULT_MII_ADDR 3445 also needs to be defined. 3446 3447- CONFIG_SYS_FAULT_MII_ADDR: 3448 MII address of the PHY to check for the Ethernet link state. 3449 3450- CONFIG_NS16550_MIN_FUNCTIONS: 3451 Define this if you desire to only have use of the NS16550_init 3452 and NS16550_putc functions for the serial driver located at 3453 drivers/serial/ns16550.c. This option is useful for saving 3454 space for already greatly restricted images, including but not 3455 limited to NAND_SPL configurations. 3456 3457- CONFIG_DISPLAY_BOARDINFO 3458 Display information about the board that U-Boot is running on 3459 when U-Boot starts up. The board function checkboard() is called 3460 to do this. 3461 3462- CONFIG_DISPLAY_BOARDINFO_LATE 3463 Similar to the previous option, but display this information 3464 later, once stdio is running and output goes to the LCD, if 3465 present. 3466 3467- CONFIG_BOARD_SIZE_LIMIT: 3468 Maximum size of the U-Boot image. When defined, the 3469 build system checks that the actual size does not 3470 exceed it. 3471 3472Low Level (hardware related) configuration options: 3473--------------------------------------------------- 3474 3475- CONFIG_SYS_CACHELINE_SIZE: 3476 Cache Line Size of the CPU. 3477 3478- CONFIG_SYS_CCSRBAR_DEFAULT: 3479 Default (power-on reset) physical address of CCSR on Freescale 3480 PowerPC SOCs. 3481 3482- CONFIG_SYS_CCSRBAR: 3483 Virtual address of CCSR. On a 32-bit build, this is typically 3484 the same value as CONFIG_SYS_CCSRBAR_DEFAULT. 3485 3486- CONFIG_SYS_CCSRBAR_PHYS: 3487 Physical address of CCSR. CCSR can be relocated to a new 3488 physical address, if desired. In this case, this macro should 3489 be set to that address. Otherwise, it should be set to the 3490 same value as CONFIG_SYS_CCSRBAR_DEFAULT. For example, CCSR 3491 is typically relocated on 36-bit builds. It is recommended 3492 that this macro be defined via the _HIGH and _LOW macros: 3493 3494 #define CONFIG_SYS_CCSRBAR_PHYS ((CONFIG_SYS_CCSRBAR_PHYS_HIGH 3495 * 1ull) << 32 | CONFIG_SYS_CCSRBAR_PHYS_LOW) 3496 3497- CONFIG_SYS_CCSRBAR_PHYS_HIGH: 3498 Bits 33-36 of CONFIG_SYS_CCSRBAR_PHYS. This value is typically 3499 either 0 (32-bit build) or 0xF (36-bit build). This macro is 3500 used in assembly code, so it must not contain typecasts or 3501 integer size suffixes (e.g. "ULL"). 3502 3503- CONFIG_SYS_CCSRBAR_PHYS_LOW: 3504 Lower 32-bits of CONFIG_SYS_CCSRBAR_PHYS. This macro is 3505 used in assembly code, so it must not contain typecasts or 3506 integer size suffixes (e.g. "ULL"). 3507 3508- CONFIG_SYS_CCSR_DO_NOT_RELOCATE: 3509 If this macro is defined, then CONFIG_SYS_CCSRBAR_PHYS will be 3510 forced to a value that ensures that CCSR is not relocated. 3511 3512- Floppy Disk Support: 3513 CONFIG_SYS_FDC_DRIVE_NUMBER 3514 3515 the default drive number (default value 0) 3516 3517 CONFIG_SYS_ISA_IO_STRIDE 3518 3519 defines the spacing between FDC chipset registers 3520 (default value 1) 3521 3522 CONFIG_SYS_ISA_IO_OFFSET 3523 3524 defines the offset of register from address. It 3525 depends on which part of the data bus is connected to 3526 the FDC chipset. (default value 0) 3527 3528 If CONFIG_SYS_ISA_IO_STRIDE CONFIG_SYS_ISA_IO_OFFSET and 3529 CONFIG_SYS_FDC_DRIVE_NUMBER are undefined, they take their 3530 default value. 3531 3532 if CONFIG_SYS_FDC_HW_INIT is defined, then the function 3533 fdc_hw_init() is called at the beginning of the FDC 3534 setup. fdc_hw_init() must be provided by the board 3535 source code. It is used to make hardware-dependent 3536 initializations. 3537 3538- CONFIG_IDE_AHB: 3539 Most IDE controllers were designed to be connected with PCI 3540 interface. Only few of them were designed for AHB interface. 3541 When software is doing ATA command and data transfer to 3542 IDE devices through IDE-AHB controller, some additional 3543 registers accessing to these kind of IDE-AHB controller 3544 is required. 3545 3546- CONFIG_SYS_IMMR: Physical address of the Internal Memory. 3547 DO NOT CHANGE unless you know exactly what you're 3548 doing! (11-4) [MPC8xx systems only] 3549 3550- CONFIG_SYS_INIT_RAM_ADDR: 3551 3552 Start address of memory area that can be used for 3553 initial data and stack; please note that this must be 3554 writable memory that is working WITHOUT special 3555 initialization, i. e. you CANNOT use normal RAM which 3556 will become available only after programming the 3557 memory controller and running certain initialization 3558 sequences. 3559 3560 U-Boot uses the following memory types: 3561 - MPC8xx: IMMR (internal memory of the CPU) 3562 3563- CONFIG_SYS_GBL_DATA_OFFSET: 3564 3565 Offset of the initial data structure in the memory 3566 area defined by CONFIG_SYS_INIT_RAM_ADDR. Usually 3567 CONFIG_SYS_GBL_DATA_OFFSET is chosen such that the initial 3568 data is located at the end of the available space 3569 (sometimes written as (CONFIG_SYS_INIT_RAM_SIZE - 3570 GENERATED_GBL_DATA_SIZE), and the initial stack is just 3571 below that area (growing from (CONFIG_SYS_INIT_RAM_ADDR + 3572 CONFIG_SYS_GBL_DATA_OFFSET) downward. 3573 3574 Note: 3575 On the MPC824X (or other systems that use the data 3576 cache for initial memory) the address chosen for 3577 CONFIG_SYS_INIT_RAM_ADDR is basically arbitrary - it must 3578 point to an otherwise UNUSED address space between 3579 the top of RAM and the start of the PCI space. 3580 3581- CONFIG_SYS_SCCR: System Clock and reset Control Register (15-27) 3582 3583- CONFIG_SYS_OR_TIMING_SDRAM: 3584 SDRAM timing 3585 3586- CONFIG_SYS_MAMR_PTA: 3587 periodic timer for refresh 3588 3589- FLASH_BASE0_PRELIM, FLASH_BASE1_PRELIM, CONFIG_SYS_REMAP_OR_AM, 3590 CONFIG_SYS_PRELIM_OR_AM, CONFIG_SYS_OR_TIMING_FLASH, CONFIG_SYS_OR0_REMAP, 3591 CONFIG_SYS_OR0_PRELIM, CONFIG_SYS_BR0_PRELIM, CONFIG_SYS_OR1_REMAP, CONFIG_SYS_OR1_PRELIM, 3592 CONFIG_SYS_BR1_PRELIM: 3593 Memory Controller Definitions: BR0/1 and OR0/1 (FLASH) 3594 3595- SDRAM_BASE2_PRELIM, SDRAM_BASE3_PRELIM, SDRAM_MAX_SIZE, 3596 CONFIG_SYS_OR_TIMING_SDRAM, CONFIG_SYS_OR2_PRELIM, CONFIG_SYS_BR2_PRELIM, 3597 CONFIG_SYS_OR3_PRELIM, CONFIG_SYS_BR3_PRELIM: 3598 Memory Controller Definitions: BR2/3 and OR2/3 (SDRAM) 3599 3600- CONFIG_PCI_ENUM_ONLY 3601 Only scan through and get the devices on the buses. 3602 Don't do any setup work, presumably because someone or 3603 something has already done it, and we don't need to do it 3604 a second time. Useful for platforms that are pre-booted 3605 by coreboot or similar. 3606 3607- CONFIG_PCI_INDIRECT_BRIDGE: 3608 Enable support for indirect PCI bridges. 3609 3610- CONFIG_SYS_SRIO: 3611 Chip has SRIO or not 3612 3613- CONFIG_SRIO1: 3614 Board has SRIO 1 port available 3615 3616- CONFIG_SRIO2: 3617 Board has SRIO 2 port available 3618 3619- CONFIG_SRIO_PCIE_BOOT_MASTER 3620 Board can support master function for Boot from SRIO and PCIE 3621 3622- CONFIG_SYS_SRIOn_MEM_VIRT: 3623 Virtual Address of SRIO port 'n' memory region 3624 3625- CONFIG_SYS_SRIOn_MEM_PHYS: 3626 Physical Address of SRIO port 'n' memory region 3627 3628- CONFIG_SYS_SRIOn_MEM_SIZE: 3629 Size of SRIO port 'n' memory region 3630 3631- CONFIG_SYS_NAND_BUSWIDTH_16BIT 3632 Defined to tell the NAND controller that the NAND chip is using 3633 a 16 bit bus. 3634 Not all NAND drivers use this symbol. 3635 Example of drivers that use it: 3636 - drivers/mtd/nand/ndfc.c 3637 - drivers/mtd/nand/mxc_nand.c 3638 3639- CONFIG_SYS_NDFC_EBC0_CFG 3640 Sets the EBC0_CFG register for the NDFC. If not defined 3641 a default value will be used. 3642 3643- CONFIG_SPD_EEPROM 3644 Get DDR timing information from an I2C EEPROM. Common 3645 with pluggable memory modules such as SODIMMs 3646 3647 SPD_EEPROM_ADDRESS 3648 I2C address of the SPD EEPROM 3649 3650- CONFIG_SYS_SPD_BUS_NUM 3651 If SPD EEPROM is on an I2C bus other than the first 3652 one, specify here. Note that the value must resolve 3653 to something your driver can deal with. 3654 3655- CONFIG_SYS_DDR_RAW_TIMING 3656 Get DDR timing information from other than SPD. Common with 3657 soldered DDR chips onboard without SPD. DDR raw timing 3658 parameters are extracted from datasheet and hard-coded into 3659 header files or board specific files. 3660 3661- CONFIG_FSL_DDR_INTERACTIVE 3662 Enable interactive DDR debugging. See doc/README.fsl-ddr. 3663 3664- CONFIG_FSL_DDR_SYNC_REFRESH 3665 Enable sync of refresh for multiple controllers. 3666 3667- CONFIG_FSL_DDR_BIST 3668 Enable built-in memory test for Freescale DDR controllers. 3669 3670- CONFIG_SYS_83XX_DDR_USES_CS0 3671 Only for 83xx systems. If specified, then DDR should 3672 be configured using CS0 and CS1 instead of CS2 and CS3. 3673 3674- CONFIG_RMII 3675 Enable RMII mode for all FECs. 3676 Note that this is a global option, we can't 3677 have one FEC in standard MII mode and another in RMII mode. 3678 3679- CONFIG_CRC32_VERIFY 3680 Add a verify option to the crc32 command. 3681 The syntax is: 3682 3683 => crc32 -v <address> <count> <crc32> 3684 3685 Where address/count indicate a memory area 3686 and crc32 is the correct crc32 which the 3687 area should have. 3688 3689- CONFIG_LOOPW 3690 Add the "loopw" memory command. This only takes effect if 3691 the memory commands are activated globally (CONFIG_CMD_MEMORY). 3692 3693- CONFIG_MX_CYCLIC 3694 Add the "mdc" and "mwc" memory commands. These are cyclic 3695 "md/mw" commands. 3696 Examples: 3697 3698 => mdc.b 10 4 500 3699 This command will print 4 bytes (10,11,12,13) each 500 ms. 3700 3701 => mwc.l 100 12345678 10 3702 This command will write 12345678 to address 100 all 10 ms. 3703 3704 This only takes effect if the memory commands are activated 3705 globally (CONFIG_CMD_MEMORY). 3706 3707- CONFIG_SKIP_LOWLEVEL_INIT 3708 [ARM, NDS32, MIPS only] If this variable is defined, then certain 3709 low level initializations (like setting up the memory 3710 controller) are omitted and/or U-Boot does not 3711 relocate itself into RAM. 3712 3713 Normally this variable MUST NOT be defined. The only 3714 exception is when U-Boot is loaded (to RAM) by some 3715 other boot loader or by a debugger which performs 3716 these initializations itself. 3717 3718- CONFIG_SKIP_LOWLEVEL_INIT_ONLY 3719 [ARM926EJ-S only] This allows just the call to lowlevel_init() 3720 to be skipped. The normal CP15 init (such as enabling the 3721 instruction cache) is still performed. 3722 3723- CONFIG_SPL_BUILD 3724 Modifies the behaviour of start.S when compiling a loader 3725 that is executed before the actual U-Boot. E.g. when 3726 compiling a NAND SPL. 3727 3728- CONFIG_TPL_BUILD 3729 Modifies the behaviour of start.S when compiling a loader 3730 that is executed after the SPL and before the actual U-Boot. 3731 It is loaded by the SPL. 3732 3733- CONFIG_SYS_MPC85XX_NO_RESETVEC 3734 Only for 85xx systems. If this variable is specified, the section 3735 .resetvec is not kept and the section .bootpg is placed in the 3736 previous 4k of the .text section. 3737 3738- CONFIG_ARCH_MAP_SYSMEM 3739 Generally U-Boot (and in particular the md command) uses 3740 effective address. It is therefore not necessary to regard 3741 U-Boot address as virtual addresses that need to be translated 3742 to physical addresses. However, sandbox requires this, since 3743 it maintains its own little RAM buffer which contains all 3744 addressable memory. This option causes some memory accesses 3745 to be mapped through map_sysmem() / unmap_sysmem(). 3746 3747- CONFIG_X86_RESET_VECTOR 3748 If defined, the x86 reset vector code is included. This is not 3749 needed when U-Boot is running from Coreboot. 3750 3751- CONFIG_SPL_AM33XX_ENABLE_RTC32K_OSC: 3752 Enables the RTC32K OSC on AM33xx based plattforms 3753 3754- CONFIG_SYS_NAND_NO_SUBPAGE_WRITE 3755 Option to disable subpage write in NAND driver 3756 driver that uses this: 3757 drivers/mtd/nand/davinci_nand.c 3758 3759Freescale QE/FMAN Firmware Support: 3760----------------------------------- 3761 3762The Freescale QUICCEngine (QE) and Frame Manager (FMAN) both support the 3763loading of "firmware", which is encoded in the QE firmware binary format. 3764This firmware often needs to be loaded during U-Boot booting, so macros 3765are used to identify the storage device (NOR flash, SPI, etc) and the address 3766within that device. 3767 3768- CONFIG_SYS_FMAN_FW_ADDR 3769 The address in the storage device where the FMAN microcode is located. The 3770 meaning of this address depends on which CONFIG_SYS_QE_FW_IN_xxx macro 3771 is also specified. 3772 3773- CONFIG_SYS_QE_FW_ADDR 3774 The address in the storage device where the QE microcode is located. The 3775 meaning of this address depends on which CONFIG_SYS_QE_FW_IN_xxx macro 3776 is also specified. 3777 3778- CONFIG_SYS_QE_FMAN_FW_LENGTH 3779 The maximum possible size of the firmware. The firmware binary format 3780 has a field that specifies the actual size of the firmware, but it 3781 might not be possible to read any part of the firmware unless some 3782 local storage is allocated to hold the entire firmware first. 3783 3784- CONFIG_SYS_QE_FMAN_FW_IN_NOR 3785 Specifies that QE/FMAN firmware is located in NOR flash, mapped as 3786 normal addressable memory via the LBC. CONFIG_SYS_FMAN_FW_ADDR is the 3787 virtual address in NOR flash. 3788 3789- CONFIG_SYS_QE_FMAN_FW_IN_NAND 3790 Specifies that QE/FMAN firmware is located in NAND flash. 3791 CONFIG_SYS_FMAN_FW_ADDR is the offset within NAND flash. 3792 3793- CONFIG_SYS_QE_FMAN_FW_IN_MMC 3794 Specifies that QE/FMAN firmware is located on the primary SD/MMC 3795 device. CONFIG_SYS_FMAN_FW_ADDR is the byte offset on that device. 3796 3797- CONFIG_SYS_QE_FMAN_FW_IN_REMOTE 3798 Specifies that QE/FMAN firmware is located in the remote (master) 3799 memory space. CONFIG_SYS_FMAN_FW_ADDR is a virtual address which 3800 can be mapped from slave TLB->slave LAW->slave SRIO or PCIE outbound 3801 window->master inbound window->master LAW->the ucode address in 3802 master's memory space. 3803 3804Freescale Layerscape Management Complex Firmware Support: 3805--------------------------------------------------------- 3806The Freescale Layerscape Management Complex (MC) supports the loading of 3807"firmware". 3808This firmware often needs to be loaded during U-Boot booting, so macros 3809are used to identify the storage device (NOR flash, SPI, etc) and the address 3810within that device. 3811 3812- CONFIG_FSL_MC_ENET 3813 Enable the MC driver for Layerscape SoCs. 3814 3815Freescale Layerscape Debug Server Support: 3816------------------------------------------- 3817The Freescale Layerscape Debug Server Support supports the loading of 3818"Debug Server firmware" and triggering SP boot-rom. 3819This firmware often needs to be loaded during U-Boot booting. 3820 3821- CONFIG_SYS_MC_RSV_MEM_ALIGN 3822 Define alignment of reserved memory MC requires 3823 3824Reproducible builds 3825------------------- 3826 3827In order to achieve reproducible builds, timestamps used in the U-Boot build 3828process have to be set to a fixed value. 3829 3830This is done using the SOURCE_DATE_EPOCH environment variable. 3831SOURCE_DATE_EPOCH is to be set on the build host's shell, not as a configuration 3832option for U-Boot or an environment variable in U-Boot. 3833 3834SOURCE_DATE_EPOCH should be set to a number of seconds since the epoch, in UTC. 3835 3836Building the Software: 3837====================== 3838 3839Building U-Boot has been tested in several native build environments 3840and in many different cross environments. Of course we cannot support 3841all possibly existing versions of cross development tools in all 3842(potentially obsolete) versions. In case of tool chain problems we 3843recommend to use the ELDK (see http://www.denx.de/wiki/DULG/ELDK) 3844which is extensively used to build and test U-Boot. 3845 3846If you are not using a native environment, it is assumed that you 3847have GNU cross compiling tools available in your path. In this case, 3848you must set the environment variable CROSS_COMPILE in your shell. 3849Note that no changes to the Makefile or any other source files are 3850necessary. For example using the ELDK on a 4xx CPU, please enter: 3851 3852 $ CROSS_COMPILE=ppc_4xx- 3853 $ export CROSS_COMPILE 3854 3855Note: If you wish to generate Windows versions of the utilities in 3856 the tools directory you can use the MinGW toolchain 3857 (http://www.mingw.org). Set your HOST tools to the MinGW 3858 toolchain and execute 'make tools'. For example: 3859 3860 $ make HOSTCC=i586-mingw32msvc-gcc HOSTSTRIP=i586-mingw32msvc-strip tools 3861 3862 Binaries such as tools/mkimage.exe will be created which can 3863 be executed on computers running Windows. 3864 3865U-Boot is intended to be simple to build. After installing the 3866sources you must configure U-Boot for one specific board type. This 3867is done by typing: 3868 3869 make NAME_defconfig 3870 3871where "NAME_defconfig" is the name of one of the existing configu- 3872rations; see boards.cfg for supported names. 3873 3874Note: for some board special configuration names may exist; check if 3875 additional information is available from the board vendor; for 3876 instance, the TQM823L systems are available without (standard) 3877 or with LCD support. You can select such additional "features" 3878 when choosing the configuration, i. e. 3879 3880 make TQM823L_defconfig 3881 - will configure for a plain TQM823L, i. e. no LCD support 3882 3883 make TQM823L_LCD_defconfig 3884 - will configure for a TQM823L with U-Boot console on LCD 3885 3886 etc. 3887 3888 3889Finally, type "make all", and you should get some working U-Boot 3890images ready for download to / installation on your system: 3891 3892- "u-boot.bin" is a raw binary image 3893- "u-boot" is an image in ELF binary format 3894- "u-boot.srec" is in Motorola S-Record format 3895 3896By default the build is performed locally and the objects are saved 3897in the source directory. One of the two methods can be used to change 3898this behavior and build U-Boot to some external directory: 3899 39001. Add O= to the make command line invocations: 3901 3902 make O=/tmp/build distclean 3903 make O=/tmp/build NAME_defconfig 3904 make O=/tmp/build all 3905 39062. Set environment variable KBUILD_OUTPUT to point to the desired location: 3907 3908 export KBUILD_OUTPUT=/tmp/build 3909 make distclean 3910 make NAME_defconfig 3911 make all 3912 3913Note that the command line "O=" setting overrides the KBUILD_OUTPUT environment 3914variable. 3915 3916 3917Please be aware that the Makefiles assume you are using GNU make, so 3918for instance on NetBSD you might need to use "gmake" instead of 3919native "make". 3920 3921 3922If the system board that you have is not listed, then you will need 3923to port U-Boot to your hardware platform. To do this, follow these 3924steps: 3925 39261. Create a new directory to hold your board specific code. Add any 3927 files you need. In your board directory, you will need at least 3928 the "Makefile" and a "<board>.c". 39292. Create a new configuration file "include/configs/<board>.h" for 3930 your board. 39313. If you're porting U-Boot to a new CPU, then also create a new 3932 directory to hold your CPU specific code. Add any files you need. 39334. Run "make <board>_defconfig" with your new name. 39345. Type "make", and you should get a working "u-boot.srec" file 3935 to be installed on your target system. 39366. Debug and solve any problems that might arise. 3937 [Of course, this last step is much harder than it sounds.] 3938 3939 3940Testing of U-Boot Modifications, Ports to New Hardware, etc.: 3941============================================================== 3942 3943If you have modified U-Boot sources (for instance added a new board 3944or support for new devices, a new CPU, etc.) you are expected to 3945provide feedback to the other developers. The feedback normally takes 3946the form of a "patch", i. e. a context diff against a certain (latest 3947official or latest in the git repository) version of U-Boot sources. 3948 3949But before you submit such a patch, please verify that your modifi- 3950cation did not break existing code. At least make sure that *ALL* of 3951the supported boards compile WITHOUT ANY compiler warnings. To do so, 3952just run the buildman script (tools/buildman/buildman), which will 3953configure and build U-Boot for ALL supported system. Be warned, this 3954will take a while. Please see the buildman README, or run 'buildman -H' 3955for documentation. 3956 3957 3958See also "U-Boot Porting Guide" below. 3959 3960 3961Monitor Commands - Overview: 3962============================ 3963 3964go - start application at address 'addr' 3965run - run commands in an environment variable 3966bootm - boot application image from memory 3967bootp - boot image via network using BootP/TFTP protocol 3968bootz - boot zImage from memory 3969tftpboot- boot image via network using TFTP protocol 3970 and env variables "ipaddr" and "serverip" 3971 (and eventually "gatewayip") 3972tftpput - upload a file via network using TFTP protocol 3973rarpboot- boot image via network using RARP/TFTP protocol 3974diskboot- boot from IDE devicebootd - boot default, i.e., run 'bootcmd' 3975loads - load S-Record file over serial line 3976loadb - load binary file over serial line (kermit mode) 3977md - memory display 3978mm - memory modify (auto-incrementing) 3979nm - memory modify (constant address) 3980mw - memory write (fill) 3981cp - memory copy 3982cmp - memory compare 3983crc32 - checksum calculation 3984i2c - I2C sub-system 3985sspi - SPI utility commands 3986base - print or set address offset 3987printenv- print environment variables 3988setenv - set environment variables 3989saveenv - save environment variables to persistent storage 3990protect - enable or disable FLASH write protection 3991erase - erase FLASH memory 3992flinfo - print FLASH memory information 3993nand - NAND memory operations (see doc/README.nand) 3994bdinfo - print Board Info structure 3995iminfo - print header information for application image 3996coninfo - print console devices and informations 3997ide - IDE sub-system 3998loop - infinite loop on address range 3999loopw - infinite write loop on address range 4000mtest - simple RAM test 4001icache - enable or disable instruction cache 4002dcache - enable or disable data cache 4003reset - Perform RESET of the CPU 4004echo - echo args to console 4005version - print monitor version 4006help - print online help 4007? - alias for 'help' 4008 4009 4010Monitor Commands - Detailed Description: 4011======================================== 4012 4013TODO. 4014 4015For now: just type "help <command>". 4016 4017 4018Environment Variables: 4019====================== 4020 4021U-Boot supports user configuration using Environment Variables which 4022can be made persistent by saving to Flash memory. 4023 4024Environment Variables are set using "setenv", printed using 4025"printenv", and saved to Flash using "saveenv". Using "setenv" 4026without a value can be used to delete a variable from the 4027environment. As long as you don't save the environment you are 4028working with an in-memory copy. In case the Flash area containing the 4029environment is erased by accident, a default environment is provided. 4030 4031Some configuration options can be set using Environment Variables. 4032 4033List of environment variables (most likely not complete): 4034 4035 baudrate - see CONFIG_BAUDRATE 4036 4037 bootdelay - see CONFIG_BOOTDELAY 4038 4039 bootcmd - see CONFIG_BOOTCOMMAND 4040 4041 bootargs - Boot arguments when booting an RTOS image 4042 4043 bootfile - Name of the image to load with TFTP 4044 4045 bootm_low - Memory range available for image processing in the bootm 4046 command can be restricted. This variable is given as 4047 a hexadecimal number and defines lowest address allowed 4048 for use by the bootm command. See also "bootm_size" 4049 environment variable. Address defined by "bootm_low" is 4050 also the base of the initial memory mapping for the Linux 4051 kernel -- see the description of CONFIG_SYS_BOOTMAPSZ and 4052 bootm_mapsize. 4053 4054 bootm_mapsize - Size of the initial memory mapping for the Linux kernel. 4055 This variable is given as a hexadecimal number and it 4056 defines the size of the memory region starting at base 4057 address bootm_low that is accessible by the Linux kernel 4058 during early boot. If unset, CONFIG_SYS_BOOTMAPSZ is used 4059 as the default value if it is defined, and bootm_size is 4060 used otherwise. 4061 4062 bootm_size - Memory range available for image processing in the bootm 4063 command can be restricted. This variable is given as 4064 a hexadecimal number and defines the size of the region 4065 allowed for use by the bootm command. See also "bootm_low" 4066 environment variable. 4067 4068 updatefile - Location of the software update file on a TFTP server, used 4069 by the automatic software update feature. Please refer to 4070 documentation in doc/README.update for more details. 4071 4072 autoload - if set to "no" (any string beginning with 'n'), 4073 "bootp" will just load perform a lookup of the 4074 configuration from the BOOTP server, but not try to 4075 load any image using TFTP 4076 4077 autostart - if set to "yes", an image loaded using the "bootp", 4078 "rarpboot", "tftpboot" or "diskboot" commands will 4079 be automatically started (by internally calling 4080 "bootm") 4081 4082 If set to "no", a standalone image passed to the 4083 "bootm" command will be copied to the load address 4084 (and eventually uncompressed), but NOT be started. 4085 This can be used to load and uncompress arbitrary 4086 data. 4087 4088 fdt_high - if set this restricts the maximum address that the 4089 flattened device tree will be copied into upon boot. 4090 For example, if you have a system with 1 GB memory 4091 at physical address 0x10000000, while Linux kernel 4092 only recognizes the first 704 MB as low memory, you 4093 may need to set fdt_high as 0x3C000000 to have the 4094 device tree blob be copied to the maximum address 4095 of the 704 MB low memory, so that Linux kernel can 4096 access it during the boot procedure. 4097 4098 If this is set to the special value 0xFFFFFFFF then 4099 the fdt will not be copied at all on boot. For this 4100 to work it must reside in writable memory, have 4101 sufficient padding on the end of it for u-boot to 4102 add the information it needs into it, and the memory 4103 must be accessible by the kernel. 4104 4105 fdtcontroladdr- if set this is the address of the control flattened 4106 device tree used by U-Boot when CONFIG_OF_CONTROL is 4107 defined. 4108 4109 i2cfast - (PPC405GP|PPC405EP only) 4110 if set to 'y' configures Linux I2C driver for fast 4111 mode (400kHZ). This environment variable is used in 4112 initialization code. So, for changes to be effective 4113 it must be saved and board must be reset. 4114 4115 initrd_high - restrict positioning of initrd images: 4116 If this variable is not set, initrd images will be 4117 copied to the highest possible address in RAM; this 4118 is usually what you want since it allows for 4119 maximum initrd size. If for some reason you want to 4120 make sure that the initrd image is loaded below the 4121 CONFIG_SYS_BOOTMAPSZ limit, you can set this environment 4122 variable to a value of "no" or "off" or "0". 4123 Alternatively, you can set it to a maximum upper 4124 address to use (U-Boot will still check that it 4125 does not overwrite the U-Boot stack and data). 4126 4127 For instance, when you have a system with 16 MB 4128 RAM, and want to reserve 4 MB from use by Linux, 4129 you can do this by adding "mem=12M" to the value of 4130 the "bootargs" variable. However, now you must make 4131 sure that the initrd image is placed in the first 4132 12 MB as well - this can be done with 4133 4134 setenv initrd_high 00c00000 4135 4136 If you set initrd_high to 0xFFFFFFFF, this is an 4137 indication to U-Boot that all addresses are legal 4138 for the Linux kernel, including addresses in flash 4139 memory. In this case U-Boot will NOT COPY the 4140 ramdisk at all. This may be useful to reduce the 4141 boot time on your system, but requires that this 4142 feature is supported by your Linux kernel. 4143 4144 ipaddr - IP address; needed for tftpboot command 4145 4146 loadaddr - Default load address for commands like "bootp", 4147 "rarpboot", "tftpboot", "loadb" or "diskboot" 4148 4149 loads_echo - see CONFIG_LOADS_ECHO 4150 4151 serverip - TFTP server IP address; needed for tftpboot command 4152 4153 bootretry - see CONFIG_BOOT_RETRY_TIME 4154 4155 bootdelaykey - see CONFIG_AUTOBOOT_DELAY_STR 4156 4157 bootstopkey - see CONFIG_AUTOBOOT_STOP_STR 4158 4159 ethprime - controls which interface is used first. 4160 4161 ethact - controls which interface is currently active. 4162 For example you can do the following 4163 4164 => setenv ethact FEC 4165 => ping 192.168.0.1 # traffic sent on FEC 4166 => setenv ethact SCC 4167 => ping 10.0.0.1 # traffic sent on SCC 4168 4169 ethrotate - When set to "no" U-Boot does not go through all 4170 available network interfaces. 4171 It just stays at the currently selected interface. 4172 4173 netretry - When set to "no" each network operation will 4174 either succeed or fail without retrying. 4175 When set to "once" the network operation will 4176 fail when all the available network interfaces 4177 are tried once without success. 4178 Useful on scripts which control the retry operation 4179 themselves. 4180 4181 npe_ucode - set load address for the NPE microcode 4182 4183 silent_linux - If set then Linux will be told to boot silently, by 4184 changing the console to be empty. If "yes" it will be 4185 made silent. If "no" it will not be made silent. If 4186 unset, then it will be made silent if the U-Boot console 4187 is silent. 4188 4189 tftpsrcp - If this is set, the value is used for TFTP's 4190 UDP source port. 4191 4192 tftpdstp - If this is set, the value is used for TFTP's UDP 4193 destination port instead of the Well Know Port 69. 4194 4195 tftpblocksize - Block size to use for TFTP transfers; if not set, 4196 we use the TFTP server's default block size 4197 4198 tftptimeout - Retransmission timeout for TFTP packets (in milli- 4199 seconds, minimum value is 1000 = 1 second). Defines 4200 when a packet is considered to be lost so it has to 4201 be retransmitted. The default is 5000 = 5 seconds. 4202 Lowering this value may make downloads succeed 4203 faster in networks with high packet loss rates or 4204 with unreliable TFTP servers. 4205 4206 tftptimeoutcountmax - maximum count of TFTP timeouts (no 4207 unit, minimum value = 0). Defines how many timeouts 4208 can happen during a single file transfer before that 4209 transfer is aborted. The default is 10, and 0 means 4210 'no timeouts allowed'. Increasing this value may help 4211 downloads succeed with high packet loss rates, or with 4212 unreliable TFTP servers or client hardware. 4213 4214 vlan - When set to a value < 4095 the traffic over 4215 Ethernet is encapsulated/received over 802.1q 4216 VLAN tagged frames. 4217 4218 bootpretryperiod - Period during which BOOTP/DHCP sends retries. 4219 Unsigned value, in milliseconds. If not set, the period will 4220 be either the default (28000), or a value based on 4221 CONFIG_NET_RETRY_COUNT, if defined. This value has 4222 precedence over the valu based on CONFIG_NET_RETRY_COUNT. 4223 4224The following image location variables contain the location of images 4225used in booting. The "Image" column gives the role of the image and is 4226not an environment variable name. The other columns are environment 4227variable names. "File Name" gives the name of the file on a TFTP 4228server, "RAM Address" gives the location in RAM the image will be 4229loaded to, and "Flash Location" gives the image's address in NOR 4230flash or offset in NAND flash. 4231 4232*Note* - these variables don't have to be defined for all boards, some 4233boards currently use other variables for these purposes, and some 4234boards use these variables for other purposes. 4235 4236Image File Name RAM Address Flash Location 4237----- --------- ----------- -------------- 4238u-boot u-boot u-boot_addr_r u-boot_addr 4239Linux kernel bootfile kernel_addr_r kernel_addr 4240device tree blob fdtfile fdt_addr_r fdt_addr 4241ramdisk ramdiskfile ramdisk_addr_r ramdisk_addr 4242 4243The following environment variables may be used and automatically 4244updated by the network boot commands ("bootp" and "rarpboot"), 4245depending the information provided by your boot server: 4246 4247 bootfile - see above 4248 dnsip - IP address of your Domain Name Server 4249 dnsip2 - IP address of your secondary Domain Name Server 4250 gatewayip - IP address of the Gateway (Router) to use 4251 hostname - Target hostname 4252 ipaddr - see above 4253 netmask - Subnet Mask 4254 rootpath - Pathname of the root filesystem on the NFS server 4255 serverip - see above 4256 4257 4258There are two special Environment Variables: 4259 4260 serial# - contains hardware identification information such 4261 as type string and/or serial number 4262 ethaddr - Ethernet address 4263 4264These variables can be set only once (usually during manufacturing of 4265the board). U-Boot refuses to delete or overwrite these variables 4266once they have been set once. 4267 4268 4269Further special Environment Variables: 4270 4271 ver - Contains the U-Boot version string as printed 4272 with the "version" command. This variable is 4273 readonly (see CONFIG_VERSION_VARIABLE). 4274 4275 4276Please note that changes to some configuration parameters may take 4277only effect after the next boot (yes, that's just like Windoze :-). 4278 4279 4280Callback functions for environment variables: 4281--------------------------------------------- 4282 4283For some environment variables, the behavior of u-boot needs to change 4284when their values are changed. This functionality allows functions to 4285be associated with arbitrary variables. On creation, overwrite, or 4286deletion, the callback will provide the opportunity for some side 4287effect to happen or for the change to be rejected. 4288 4289The callbacks are named and associated with a function using the 4290U_BOOT_ENV_CALLBACK macro in your board or driver code. 4291 4292These callbacks are associated with variables in one of two ways. The 4293static list can be added to by defining CONFIG_ENV_CALLBACK_LIST_STATIC 4294in the board configuration to a string that defines a list of 4295associations. The list must be in the following format: 4296 4297 entry = variable_name[:callback_name] 4298 list = entry[,list] 4299 4300If the callback name is not specified, then the callback is deleted. 4301Spaces are also allowed anywhere in the list. 4302 4303Callbacks can also be associated by defining the ".callbacks" variable 4304with the same list format above. Any association in ".callbacks" will 4305override any association in the static list. You can define 4306CONFIG_ENV_CALLBACK_LIST_DEFAULT to a list (string) to define the 4307".callbacks" environment variable in the default or embedded environment. 4308 4309If CONFIG_REGEX is defined, the variable_name above is evaluated as a 4310regular expression. This allows multiple variables to be connected to 4311the same callback without explicitly listing them all out. 4312 4313 4314Command Line Parsing: 4315===================== 4316 4317There are two different command line parsers available with U-Boot: 4318the old "simple" one, and the much more powerful "hush" shell: 4319 4320Old, simple command line parser: 4321-------------------------------- 4322 4323- supports environment variables (through setenv / saveenv commands) 4324- several commands on one line, separated by ';' 4325- variable substitution using "... ${name} ..." syntax 4326- special characters ('$', ';') can be escaped by prefixing with '\', 4327 for example: 4328 setenv bootcmd bootm \${address} 4329- You can also escape text by enclosing in single apostrophes, for example: 4330 setenv addip 'setenv bootargs $bootargs ip=$ipaddr:$serverip:$gatewayip:$netmask:$hostname::off' 4331 4332Hush shell: 4333----------- 4334 4335- similar to Bourne shell, with control structures like 4336 if...then...else...fi, for...do...done; while...do...done, 4337 until...do...done, ... 4338- supports environment ("global") variables (through setenv / saveenv 4339 commands) and local shell variables (through standard shell syntax 4340 "name=value"); only environment variables can be used with "run" 4341 command 4342 4343General rules: 4344-------------- 4345 4346(1) If a command line (or an environment variable executed by a "run" 4347 command) contains several commands separated by semicolon, and 4348 one of these commands fails, then the remaining commands will be 4349 executed anyway. 4350 4351(2) If you execute several variables with one call to run (i. e. 4352 calling run with a list of variables as arguments), any failing 4353 command will cause "run" to terminate, i. e. the remaining 4354 variables are not executed. 4355 4356Note for Redundant Ethernet Interfaces: 4357======================================= 4358 4359Some boards come with redundant Ethernet interfaces; U-Boot supports 4360such configurations and is capable of automatic selection of a 4361"working" interface when needed. MAC assignment works as follows: 4362 4363Network interfaces are numbered eth0, eth1, eth2, ... Corresponding 4364MAC addresses can be stored in the environment as "ethaddr" (=>eth0), 4365"eth1addr" (=>eth1), "eth2addr", ... 4366 4367If the network interface stores some valid MAC address (for instance 4368in SROM), this is used as default address if there is NO correspon- 4369ding setting in the environment; if the corresponding environment 4370variable is set, this overrides the settings in the card; that means: 4371 4372o If the SROM has a valid MAC address, and there is no address in the 4373 environment, the SROM's address is used. 4374 4375o If there is no valid address in the SROM, and a definition in the 4376 environment exists, then the value from the environment variable is 4377 used. 4378 4379o If both the SROM and the environment contain a MAC address, and 4380 both addresses are the same, this MAC address is used. 4381 4382o If both the SROM and the environment contain a MAC address, and the 4383 addresses differ, the value from the environment is used and a 4384 warning is printed. 4385 4386o If neither SROM nor the environment contain a MAC address, an error 4387 is raised. If CONFIG_NET_RANDOM_ETHADDR is defined, then in this case 4388 a random, locally-assigned MAC is used. 4389 4390If Ethernet drivers implement the 'write_hwaddr' function, valid MAC addresses 4391will be programmed into hardware as part of the initialization process. This 4392may be skipped by setting the appropriate 'ethmacskip' environment variable. 4393The naming convention is as follows: 4394"ethmacskip" (=>eth0), "eth1macskip" (=>eth1) etc. 4395 4396Image Formats: 4397============== 4398 4399U-Boot is capable of booting (and performing other auxiliary operations on) 4400images in two formats: 4401 4402New uImage format (FIT) 4403----------------------- 4404 4405Flexible and powerful format based on Flattened Image Tree -- FIT (similar 4406to Flattened Device Tree). It allows the use of images with multiple 4407components (several kernels, ramdisks, etc.), with contents protected by 4408SHA1, MD5 or CRC32. More details are found in the doc/uImage.FIT directory. 4409 4410 4411Old uImage format 4412----------------- 4413 4414Old image format is based on binary files which can be basically anything, 4415preceded by a special header; see the definitions in include/image.h for 4416details; basically, the header defines the following image properties: 4417 4418* Target Operating System (Provisions for OpenBSD, NetBSD, FreeBSD, 4419 4.4BSD, Linux, SVR4, Esix, Solaris, Irix, SCO, Dell, NCR, VxWorks, 4420 LynxOS, pSOS, QNX, RTEMS, INTEGRITY; 4421 Currently supported: Linux, NetBSD, VxWorks, QNX, RTEMS, LynxOS, 4422 INTEGRITY). 4423* Target CPU Architecture (Provisions for Alpha, ARM, Intel x86, 4424 IA64, MIPS, NDS32, Nios II, PowerPC, IBM S390, SuperH, Sparc, Sparc 64 Bit; 4425 Currently supported: ARM, Intel x86, MIPS, NDS32, Nios II, PowerPC). 4426* Compression Type (uncompressed, gzip, bzip2) 4427* Load Address 4428* Entry Point 4429* Image Name 4430* Image Timestamp 4431 4432The header is marked by a special Magic Number, and both the header 4433and the data portions of the image are secured against corruption by 4434CRC32 checksums. 4435 4436 4437Linux Support: 4438============== 4439 4440Although U-Boot should support any OS or standalone application 4441easily, the main focus has always been on Linux during the design of 4442U-Boot. 4443 4444U-Boot includes many features that so far have been part of some 4445special "boot loader" code within the Linux kernel. Also, any 4446"initrd" images to be used are no longer part of one big Linux image; 4447instead, kernel and "initrd" are separate images. This implementation 4448serves several purposes: 4449 4450- the same features can be used for other OS or standalone 4451 applications (for instance: using compressed images to reduce the 4452 Flash memory footprint) 4453 4454- it becomes much easier to port new Linux kernel versions because 4455 lots of low-level, hardware dependent stuff are done by U-Boot 4456 4457- the same Linux kernel image can now be used with different "initrd" 4458 images; of course this also means that different kernel images can 4459 be run with the same "initrd". This makes testing easier (you don't 4460 have to build a new "zImage.initrd" Linux image when you just 4461 change a file in your "initrd"). Also, a field-upgrade of the 4462 software is easier now. 4463 4464 4465Linux HOWTO: 4466============ 4467 4468Porting Linux to U-Boot based systems: 4469--------------------------------------- 4470 4471U-Boot cannot save you from doing all the necessary modifications to 4472configure the Linux device drivers for use with your target hardware 4473(no, we don't intend to provide a full virtual machine interface to 4474Linux :-). 4475 4476But now you can ignore ALL boot loader code (in arch/powerpc/mbxboot). 4477 4478Just make sure your machine specific header file (for instance 4479include/asm-ppc/tqm8xx.h) includes the same definition of the Board 4480Information structure as we define in include/asm-<arch>/u-boot.h, 4481and make sure that your definition of IMAP_ADDR uses the same value 4482as your U-Boot configuration in CONFIG_SYS_IMMR. 4483 4484Note that U-Boot now has a driver model, a unified model for drivers. 4485If you are adding a new driver, plumb it into driver model. If there 4486is no uclass available, you are encouraged to create one. See 4487doc/driver-model. 4488 4489 4490Configuring the Linux kernel: 4491----------------------------- 4492 4493No specific requirements for U-Boot. Make sure you have some root 4494device (initial ramdisk, NFS) for your target system. 4495 4496 4497Building a Linux Image: 4498----------------------- 4499 4500With U-Boot, "normal" build targets like "zImage" or "bzImage" are 4501not used. If you use recent kernel source, a new build target 4502"uImage" will exist which automatically builds an image usable by 4503U-Boot. Most older kernels also have support for a "pImage" target, 4504which was introduced for our predecessor project PPCBoot and uses a 4505100% compatible format. 4506 4507Example: 4508 4509 make TQM850L_defconfig 4510 make oldconfig 4511 make dep 4512 make uImage 4513 4514The "uImage" build target uses a special tool (in 'tools/mkimage') to 4515encapsulate a compressed Linux kernel image with header information, 4516CRC32 checksum etc. for use with U-Boot. This is what we are doing: 4517 4518* build a standard "vmlinux" kernel image (in ELF binary format): 4519 4520* convert the kernel into a raw binary image: 4521 4522 ${CROSS_COMPILE}-objcopy -O binary \ 4523 -R .note -R .comment \ 4524 -S vmlinux linux.bin 4525 4526* compress the binary image: 4527 4528 gzip -9 linux.bin 4529 4530* package compressed binary image for U-Boot: 4531 4532 mkimage -A ppc -O linux -T kernel -C gzip \ 4533 -a 0 -e 0 -n "Linux Kernel Image" \ 4534 -d linux.bin.gz uImage 4535 4536 4537The "mkimage" tool can also be used to create ramdisk images for use 4538with U-Boot, either separated from the Linux kernel image, or 4539combined into one file. "mkimage" encapsulates the images with a 64 4540byte header containing information about target architecture, 4541operating system, image type, compression method, entry points, time 4542stamp, CRC32 checksums, etc. 4543 4544"mkimage" can be called in two ways: to verify existing images and 4545print the header information, or to build new images. 4546 4547In the first form (with "-l" option) mkimage lists the information 4548contained in the header of an existing U-Boot image; this includes 4549checksum verification: 4550 4551 tools/mkimage -l image 4552 -l ==> list image header information 4553 4554The second form (with "-d" option) is used to build a U-Boot image 4555from a "data file" which is used as image payload: 4556 4557 tools/mkimage -A arch -O os -T type -C comp -a addr -e ep \ 4558 -n name -d data_file image 4559 -A ==> set architecture to 'arch' 4560 -O ==> set operating system to 'os' 4561 -T ==> set image type to 'type' 4562 -C ==> set compression type 'comp' 4563 -a ==> set load address to 'addr' (hex) 4564 -e ==> set entry point to 'ep' (hex) 4565 -n ==> set image name to 'name' 4566 -d ==> use image data from 'datafile' 4567 4568Right now, all Linux kernels for PowerPC systems use the same load 4569address (0x00000000), but the entry point address depends on the 4570kernel version: 4571 4572- 2.2.x kernels have the entry point at 0x0000000C, 4573- 2.3.x and later kernels have the entry point at 0x00000000. 4574 4575So a typical call to build a U-Boot image would read: 4576 4577 -> tools/mkimage -n '2.4.4 kernel for TQM850L' \ 4578 > -A ppc -O linux -T kernel -C gzip -a 0 -e 0 \ 4579 > -d /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/powerpc/coffboot/vmlinux.gz \ 4580 > examples/uImage.TQM850L 4581 Image Name: 2.4.4 kernel for TQM850L 4582 Created: Wed Jul 19 02:34:59 2000 4583 Image Type: PowerPC Linux Kernel Image (gzip compressed) 4584 Data Size: 335725 Bytes = 327.86 kB = 0.32 MB 4585 Load Address: 0x00000000 4586 Entry Point: 0x00000000 4587 4588To verify the contents of the image (or check for corruption): 4589 4590 -> tools/mkimage -l examples/uImage.TQM850L 4591 Image Name: 2.4.4 kernel for TQM850L 4592 Created: Wed Jul 19 02:34:59 2000 4593 Image Type: PowerPC Linux Kernel Image (gzip compressed) 4594 Data Size: 335725 Bytes = 327.86 kB = 0.32 MB 4595 Load Address: 0x00000000 4596 Entry Point: 0x00000000 4597 4598NOTE: for embedded systems where boot time is critical you can trade 4599speed for memory and install an UNCOMPRESSED image instead: this 4600needs more space in Flash, but boots much faster since it does not 4601need to be uncompressed: 4602 4603 -> gunzip /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/powerpc/coffboot/vmlinux.gz 4604 -> tools/mkimage -n '2.4.4 kernel for TQM850L' \ 4605 > -A ppc -O linux -T kernel -C none -a 0 -e 0 \ 4606 > -d /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/powerpc/coffboot/vmlinux \ 4607 > examples/uImage.TQM850L-uncompressed 4608 Image Name: 2.4.4 kernel for TQM850L 4609 Created: Wed Jul 19 02:34:59 2000 4610 Image Type: PowerPC Linux Kernel Image (uncompressed) 4611 Data Size: 792160 Bytes = 773.59 kB = 0.76 MB 4612 Load Address: 0x00000000 4613 Entry Point: 0x00000000 4614 4615 4616Similar you can build U-Boot images from a 'ramdisk.image.gz' file 4617when your kernel is intended to use an initial ramdisk: 4618 4619 -> tools/mkimage -n 'Simple Ramdisk Image' \ 4620 > -A ppc -O linux -T ramdisk -C gzip \ 4621 > -d /LinuxPPC/images/SIMPLE-ramdisk.image.gz examples/simple-initrd 4622 Image Name: Simple Ramdisk Image 4623 Created: Wed Jan 12 14:01:50 2000 4624 Image Type: PowerPC Linux RAMDisk Image (gzip compressed) 4625 Data Size: 566530 Bytes = 553.25 kB = 0.54 MB 4626 Load Address: 0x00000000 4627 Entry Point: 0x00000000 4628 4629The "dumpimage" is a tool to disassemble images built by mkimage. Its "-i" 4630option performs the converse operation of the mkimage's second form (the "-d" 4631option). Given an image built by mkimage, the dumpimage extracts a "data file" 4632from the image: 4633 4634 tools/dumpimage -i image -T type -p position data_file 4635 -i ==> extract from the 'image' a specific 'data_file' 4636 -T ==> set image type to 'type' 4637 -p ==> 'position' (starting at 0) of the 'data_file' inside the 'image' 4638 4639 4640Installing a Linux Image: 4641------------------------- 4642 4643To downloading a U-Boot image over the serial (console) interface, 4644you must convert the image to S-Record format: 4645 4646 objcopy -I binary -O srec examples/image examples/image.srec 4647 4648The 'objcopy' does not understand the information in the U-Boot 4649image header, so the resulting S-Record file will be relative to 4650address 0x00000000. To load it to a given address, you need to 4651specify the target address as 'offset' parameter with the 'loads' 4652command. 4653 4654Example: install the image to address 0x40100000 (which on the 4655TQM8xxL is in the first Flash bank): 4656 4657 => erase 40100000 401FFFFF 4658 4659 .......... done 4660 Erased 8 sectors 4661 4662 => loads 40100000 4663 ## Ready for S-Record download ... 4664 ~>examples/image.srec 4665 1 2 3 4 5 6 7 8 9 10 11 12 13 ... 4666 ... 4667 15989 15990 15991 15992 4668 [file transfer complete] 4669 [connected] 4670 ## Start Addr = 0x00000000 4671 4672 4673You can check the success of the download using the 'iminfo' command; 4674this includes a checksum verification so you can be sure no data 4675corruption happened: 4676 4677 => imi 40100000 4678 4679 ## Checking Image at 40100000 ... 4680 Image Name: 2.2.13 for initrd on TQM850L 4681 Image Type: PowerPC Linux Kernel Image (gzip compressed) 4682 Data Size: 335725 Bytes = 327 kB = 0 MB 4683 Load Address: 00000000 4684 Entry Point: 0000000c 4685 Verifying Checksum ... OK 4686 4687 4688Boot Linux: 4689----------- 4690 4691The "bootm" command is used to boot an application that is stored in 4692memory (RAM or Flash). In case of a Linux kernel image, the contents 4693of the "bootargs" environment variable is passed to the kernel as 4694parameters. You can check and modify this variable using the 4695"printenv" and "setenv" commands: 4696 4697 4698 => printenv bootargs 4699 bootargs=root=/dev/ram 4700 4701 => setenv bootargs root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2 4702 4703 => printenv bootargs 4704 bootargs=root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2 4705 4706 => bootm 40020000 4707 ## Booting Linux kernel at 40020000 ... 4708 Image Name: 2.2.13 for NFS on TQM850L 4709 Image Type: PowerPC Linux Kernel Image (gzip compressed) 4710 Data Size: 381681 Bytes = 372 kB = 0 MB 4711 Load Address: 00000000 4712 Entry Point: 0000000c 4713 Verifying Checksum ... OK 4714 Uncompressing Kernel Image ... OK 4715 Linux version 2.2.13 (wd@denx.local.net) (gcc version 2.95.2 19991024 (release)) #1 Wed Jul 19 02:35:17 MEST 2000 4716 Boot arguments: root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2 4717 time_init: decrementer frequency = 187500000/60 4718 Calibrating delay loop... 49.77 BogoMIPS 4719 Memory: 15208k available (700k kernel code, 444k data, 32k init) [c0000000,c1000000] 4720 ... 4721 4722If you want to boot a Linux kernel with initial RAM disk, you pass 4723the memory addresses of both the kernel and the initrd image (PPBCOOT 4724format!) to the "bootm" command: 4725 4726 => imi 40100000 40200000 4727 4728 ## Checking Image at 40100000 ... 4729 Image Name: 2.2.13 for initrd on TQM850L 4730 Image Type: PowerPC Linux Kernel Image (gzip compressed) 4731 Data Size: 335725 Bytes = 327 kB = 0 MB 4732 Load Address: 00000000 4733 Entry Point: 0000000c 4734 Verifying Checksum ... OK 4735 4736 ## Checking Image at 40200000 ... 4737 Image Name: Simple Ramdisk Image 4738 Image Type: PowerPC Linux RAMDisk Image (gzip compressed) 4739 Data Size: 566530 Bytes = 553 kB = 0 MB 4740 Load Address: 00000000 4741 Entry Point: 00000000 4742 Verifying Checksum ... OK 4743 4744 => bootm 40100000 40200000 4745 ## Booting Linux kernel at 40100000 ... 4746 Image Name: 2.2.13 for initrd on TQM850L 4747 Image Type: PowerPC Linux Kernel Image (gzip compressed) 4748 Data Size: 335725 Bytes = 327 kB = 0 MB 4749 Load Address: 00000000 4750 Entry Point: 0000000c 4751 Verifying Checksum ... OK 4752 Uncompressing Kernel Image ... OK 4753 ## Loading RAMDisk Image at 40200000 ... 4754 Image Name: Simple Ramdisk Image 4755 Image Type: PowerPC Linux RAMDisk Image (gzip compressed) 4756 Data Size: 566530 Bytes = 553 kB = 0 MB 4757 Load Address: 00000000 4758 Entry Point: 00000000 4759 Verifying Checksum ... OK 4760 Loading Ramdisk ... OK 4761 Linux version 2.2.13 (wd@denx.local.net) (gcc version 2.95.2 19991024 (release)) #1 Wed Jul 19 02:32:08 MEST 2000 4762 Boot arguments: root=/dev/ram 4763 time_init: decrementer frequency = 187500000/60 4764 Calibrating delay loop... 49.77 BogoMIPS 4765 ... 4766 RAMDISK: Compressed image found at block 0 4767 VFS: Mounted root (ext2 filesystem). 4768 4769 bash# 4770 4771Boot Linux and pass a flat device tree: 4772----------- 4773 4774First, U-Boot must be compiled with the appropriate defines. See the section 4775titled "Linux Kernel Interface" above for a more in depth explanation. The 4776following is an example of how to start a kernel and pass an updated 4777flat device tree: 4778 4779=> print oftaddr 4780oftaddr=0x300000 4781=> print oft 4782oft=oftrees/mpc8540ads.dtb 4783=> tftp $oftaddr $oft 4784Speed: 1000, full duplex 4785Using TSEC0 device 4786TFTP from server 192.168.1.1; our IP address is 192.168.1.101 4787Filename 'oftrees/mpc8540ads.dtb'. 4788Load address: 0x300000 4789Loading: # 4790done 4791Bytes transferred = 4106 (100a hex) 4792=> tftp $loadaddr $bootfile 4793Speed: 1000, full duplex 4794Using TSEC0 device 4795TFTP from server 192.168.1.1; our IP address is 192.168.1.2 4796Filename 'uImage'. 4797Load address: 0x200000 4798Loading:############ 4799done 4800Bytes transferred = 1029407 (fb51f hex) 4801=> print loadaddr 4802loadaddr=200000 4803=> print oftaddr 4804oftaddr=0x300000 4805=> bootm $loadaddr - $oftaddr 4806## Booting image at 00200000 ... 4807 Image Name: Linux-2.6.17-dirty 4808 Image Type: PowerPC Linux Kernel Image (gzip compressed) 4809 Data Size: 1029343 Bytes = 1005.2 kB 4810 Load Address: 00000000 4811 Entry Point: 00000000 4812 Verifying Checksum ... OK 4813 Uncompressing Kernel Image ... OK 4814Booting using flat device tree at 0x300000 4815Using MPC85xx ADS machine description 4816Memory CAM mapping: CAM0=256Mb, CAM1=256Mb, CAM2=0Mb residual: 0Mb 4817[snip] 4818 4819 4820More About U-Boot Image Types: 4821------------------------------ 4822 4823U-Boot supports the following image types: 4824 4825 "Standalone Programs" are directly runnable in the environment 4826 provided by U-Boot; it is expected that (if they behave 4827 well) you can continue to work in U-Boot after return from 4828 the Standalone Program. 4829 "OS Kernel Images" are usually images of some Embedded OS which 4830 will take over control completely. Usually these programs 4831 will install their own set of exception handlers, device 4832 drivers, set up the MMU, etc. - this means, that you cannot 4833 expect to re-enter U-Boot except by resetting the CPU. 4834 "RAMDisk Images" are more or less just data blocks, and their 4835 parameters (address, size) are passed to an OS kernel that is 4836 being started. 4837 "Multi-File Images" contain several images, typically an OS 4838 (Linux) kernel image and one or more data images like 4839 RAMDisks. This construct is useful for instance when you want 4840 to boot over the network using BOOTP etc., where the boot 4841 server provides just a single image file, but you want to get 4842 for instance an OS kernel and a RAMDisk image. 4843 4844 "Multi-File Images" start with a list of image sizes, each 4845 image size (in bytes) specified by an "uint32_t" in network 4846 byte order. This list is terminated by an "(uint32_t)0". 4847 Immediately after the terminating 0 follow the images, one by 4848 one, all aligned on "uint32_t" boundaries (size rounded up to 4849 a multiple of 4 bytes). 4850 4851 "Firmware Images" are binary images containing firmware (like 4852 U-Boot or FPGA images) which usually will be programmed to 4853 flash memory. 4854 4855 "Script files" are command sequences that will be executed by 4856 U-Boot's command interpreter; this feature is especially 4857 useful when you configure U-Boot to use a real shell (hush) 4858 as command interpreter. 4859 4860Booting the Linux zImage: 4861------------------------- 4862 4863On some platforms, it's possible to boot Linux zImage. This is done 4864using the "bootz" command. The syntax of "bootz" command is the same 4865as the syntax of "bootm" command. 4866 4867Note, defining the CONFIG_SUPPORT_RAW_INITRD allows user to supply 4868kernel with raw initrd images. The syntax is slightly different, the 4869address of the initrd must be augmented by it's size, in the following 4870format: "<initrd addres>:<initrd size>". 4871 4872 4873Standalone HOWTO: 4874================= 4875 4876One of the features of U-Boot is that you can dynamically load and 4877run "standalone" applications, which can use some resources of 4878U-Boot like console I/O functions or interrupt services. 4879 4880Two simple examples are included with the sources: 4881 4882"Hello World" Demo: 4883------------------- 4884 4885'examples/hello_world.c' contains a small "Hello World" Demo 4886application; it is automatically compiled when you build U-Boot. 4887It's configured to run at address 0x00040004, so you can play with it 4888like that: 4889 4890 => loads 4891 ## Ready for S-Record download ... 4892 ~>examples/hello_world.srec 4893 1 2 3 4 5 6 7 8 9 10 11 ... 4894 [file transfer complete] 4895 [connected] 4896 ## Start Addr = 0x00040004 4897 4898 => go 40004 Hello World! This is a test. 4899 ## Starting application at 0x00040004 ... 4900 Hello World 4901 argc = 7 4902 argv[0] = "40004" 4903 argv[1] = "Hello" 4904 argv[2] = "World!" 4905 argv[3] = "This" 4906 argv[4] = "is" 4907 argv[5] = "a" 4908 argv[6] = "test." 4909 argv[7] = "<NULL>" 4910 Hit any key to exit ... 4911 4912 ## Application terminated, rc = 0x0 4913 4914Another example, which demonstrates how to register a CPM interrupt 4915handler with the U-Boot code, can be found in 'examples/timer.c'. 4916Here, a CPM timer is set up to generate an interrupt every second. 4917The interrupt service routine is trivial, just printing a '.' 4918character, but this is just a demo program. The application can be 4919controlled by the following keys: 4920 4921 ? - print current values og the CPM Timer registers 4922 b - enable interrupts and start timer 4923 e - stop timer and disable interrupts 4924 q - quit application 4925 4926 => loads 4927 ## Ready for S-Record download ... 4928 ~>examples/timer.srec 4929 1 2 3 4 5 6 7 8 9 10 11 ... 4930 [file transfer complete] 4931 [connected] 4932 ## Start Addr = 0x00040004 4933 4934 => go 40004 4935 ## Starting application at 0x00040004 ... 4936 TIMERS=0xfff00980 4937 Using timer 1 4938 tgcr @ 0xfff00980, tmr @ 0xfff00990, trr @ 0xfff00994, tcr @ 0xfff00998, tcn @ 0xfff0099c, ter @ 0xfff009b0 4939 4940Hit 'b': 4941 [q, b, e, ?] Set interval 1000000 us 4942 Enabling timer 4943Hit '?': 4944 [q, b, e, ?] ........ 4945 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0xef6, ter=0x0 4946Hit '?': 4947 [q, b, e, ?] . 4948 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x2ad4, ter=0x0 4949Hit '?': 4950 [q, b, e, ?] . 4951 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x1efc, ter=0x0 4952Hit '?': 4953 [q, b, e, ?] . 4954 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x169d, ter=0x0 4955Hit 'e': 4956 [q, b, e, ?] ...Stopping timer 4957Hit 'q': 4958 [q, b, e, ?] ## Application terminated, rc = 0x0 4959 4960 4961Minicom warning: 4962================ 4963 4964Over time, many people have reported problems when trying to use the 4965"minicom" terminal emulation program for serial download. I (wd) 4966consider minicom to be broken, and recommend not to use it. Under 4967Unix, I recommend to use C-Kermit for general purpose use (and 4968especially for kermit binary protocol download ("loadb" command), and 4969use "cu" for S-Record download ("loads" command). See 4970http://www.denx.de/wiki/view/DULG/SystemSetup#Section_4.3. 4971for help with kermit. 4972 4973 4974Nevertheless, if you absolutely want to use it try adding this 4975configuration to your "File transfer protocols" section: 4976 4977 Name Program Name U/D FullScr IO-Red. Multi 4978 X kermit /usr/bin/kermit -i -l %l -s Y U Y N N 4979 Y kermit /usr/bin/kermit -i -l %l -r N D Y N N 4980 4981 4982NetBSD Notes: 4983============= 4984 4985Starting at version 0.9.2, U-Boot supports NetBSD both as host 4986(build U-Boot) and target system (boots NetBSD/mpc8xx). 4987 4988Building requires a cross environment; it is known to work on 4989NetBSD/i386 with the cross-powerpc-netbsd-1.3 package (you will also 4990need gmake since the Makefiles are not compatible with BSD make). 4991Note that the cross-powerpc package does not install include files; 4992attempting to build U-Boot will fail because <machine/ansi.h> is 4993missing. This file has to be installed and patched manually: 4994 4995 # cd /usr/pkg/cross/powerpc-netbsd/include 4996 # mkdir powerpc 4997 # ln -s powerpc machine 4998 # cp /usr/src/sys/arch/powerpc/include/ansi.h powerpc/ansi.h 4999 # ${EDIT} powerpc/ansi.h ## must remove __va_list, _BSD_VA_LIST 5000 5001Native builds *don't* work due to incompatibilities between native 5002and U-Boot include files. 5003 5004Booting assumes that (the first part of) the image booted is a 5005stage-2 loader which in turn loads and then invokes the kernel 5006proper. Loader sources will eventually appear in the NetBSD source 5007tree (probably in sys/arc/mpc8xx/stand/u-boot_stage2/); in the 5008meantime, see ftp://ftp.denx.de/pub/u-boot/ppcboot_stage2.tar.gz 5009 5010 5011Implementation Internals: 5012========================= 5013 5014The following is not intended to be a complete description of every 5015implementation detail. However, it should help to understand the 5016inner workings of U-Boot and make it easier to port it to custom 5017hardware. 5018 5019 5020Initial Stack, Global Data: 5021--------------------------- 5022 5023The implementation of U-Boot is complicated by the fact that U-Boot 5024starts running out of ROM (flash memory), usually without access to 5025system RAM (because the memory controller is not initialized yet). 5026This means that we don't have writable Data or BSS segments, and BSS 5027is not initialized as zero. To be able to get a C environment working 5028at all, we have to allocate at least a minimal stack. Implementation 5029options for this are defined and restricted by the CPU used: Some CPU 5030models provide on-chip memory (like the IMMR area on MPC8xx and 5031MPC826x processors), on others (parts of) the data cache can be 5032locked as (mis-) used as memory, etc. 5033 5034 Chris Hallinan posted a good summary of these issues to the 5035 U-Boot mailing list: 5036 5037 Subject: RE: [U-Boot-Users] RE: More On Memory Bank x (nothingness)? 5038 From: "Chris Hallinan" <clh@net1plus.com> 5039 Date: Mon, 10 Feb 2003 16:43:46 -0500 (22:43 MET) 5040 ... 5041 5042 Correct me if I'm wrong, folks, but the way I understand it 5043 is this: Using DCACHE as initial RAM for Stack, etc, does not 5044 require any physical RAM backing up the cache. The cleverness 5045 is that the cache is being used as a temporary supply of 5046 necessary storage before the SDRAM controller is setup. It's 5047 beyond the scope of this list to explain the details, but you 5048 can see how this works by studying the cache architecture and 5049 operation in the architecture and processor-specific manuals. 5050 5051 OCM is On Chip Memory, which I believe the 405GP has 4K. It 5052 is another option for the system designer to use as an 5053 initial stack/RAM area prior to SDRAM being available. Either 5054 option should work for you. Using CS 4 should be fine if your 5055 board designers haven't used it for something that would 5056 cause you grief during the initial boot! It is frequently not 5057 used. 5058 5059 CONFIG_SYS_INIT_RAM_ADDR should be somewhere that won't interfere 5060 with your processor/board/system design. The default value 5061 you will find in any recent u-boot distribution in 5062 walnut.h should work for you. I'd set it to a value larger 5063 than your SDRAM module. If you have a 64MB SDRAM module, set 5064 it above 400_0000. Just make sure your board has no resources 5065 that are supposed to respond to that address! That code in 5066 start.S has been around a while and should work as is when 5067 you get the config right. 5068 5069 -Chris Hallinan 5070 DS4.COM, Inc. 5071 5072It is essential to remember this, since it has some impact on the C 5073code for the initialization procedures: 5074 5075* Initialized global data (data segment) is read-only. Do not attempt 5076 to write it. 5077 5078* Do not use any uninitialized global data (or implicitly initialized 5079 as zero data - BSS segment) at all - this is undefined, initiali- 5080 zation is performed later (when relocating to RAM). 5081 5082* Stack space is very limited. Avoid big data buffers or things like 5083 that. 5084 5085Having only the stack as writable memory limits means we cannot use 5086normal global data to share information between the code. But it 5087turned out that the implementation of U-Boot can be greatly 5088simplified by making a global data structure (gd_t) available to all 5089functions. We could pass a pointer to this data as argument to _all_ 5090functions, but this would bloat the code. Instead we use a feature of 5091the GCC compiler (Global Register Variables) to share the data: we 5092place a pointer (gd) to the global data into a register which we 5093reserve for this purpose. 5094 5095When choosing a register for such a purpose we are restricted by the 5096relevant (E)ABI specifications for the current architecture, and by 5097GCC's implementation. 5098 5099For PowerPC, the following registers have specific use: 5100 R1: stack pointer 5101 R2: reserved for system use 5102 R3-R4: parameter passing and return values 5103 R5-R10: parameter passing 5104 R13: small data area pointer 5105 R30: GOT pointer 5106 R31: frame pointer 5107 5108 (U-Boot also uses R12 as internal GOT pointer. r12 5109 is a volatile register so r12 needs to be reset when 5110 going back and forth between asm and C) 5111 5112 ==> U-Boot will use R2 to hold a pointer to the global data 5113 5114 Note: on PPC, we could use a static initializer (since the 5115 address of the global data structure is known at compile time), 5116 but it turned out that reserving a register results in somewhat 5117 smaller code - although the code savings are not that big (on 5118 average for all boards 752 bytes for the whole U-Boot image, 5119 624 text + 127 data). 5120 5121On ARM, the following registers are used: 5122 5123 R0: function argument word/integer result 5124 R1-R3: function argument word 5125 R9: platform specific 5126 R10: stack limit (used only if stack checking is enabled) 5127 R11: argument (frame) pointer 5128 R12: temporary workspace 5129 R13: stack pointer 5130 R14: link register 5131 R15: program counter 5132 5133 ==> U-Boot will use R9 to hold a pointer to the global data 5134 5135 Note: on ARM, only R_ARM_RELATIVE relocations are supported. 5136 5137On Nios II, the ABI is documented here: 5138 http://www.altera.com/literature/hb/nios2/n2cpu_nii51016.pdf 5139 5140 ==> U-Boot will use gp to hold a pointer to the global data 5141 5142 Note: on Nios II, we give "-G0" option to gcc and don't use gp 5143 to access small data sections, so gp is free. 5144 5145On NDS32, the following registers are used: 5146 5147 R0-R1: argument/return 5148 R2-R5: argument 5149 R15: temporary register for assembler 5150 R16: trampoline register 5151 R28: frame pointer (FP) 5152 R29: global pointer (GP) 5153 R30: link register (LP) 5154 R31: stack pointer (SP) 5155 PC: program counter (PC) 5156 5157 ==> U-Boot will use R10 to hold a pointer to the global data 5158 5159NOTE: DECLARE_GLOBAL_DATA_PTR must be used with file-global scope, 5160or current versions of GCC may "optimize" the code too much. 5161 5162Memory Management: 5163------------------ 5164 5165U-Boot runs in system state and uses physical addresses, i.e. the 5166MMU is not used either for address mapping nor for memory protection. 5167 5168The available memory is mapped to fixed addresses using the memory 5169controller. In this process, a contiguous block is formed for each 5170memory type (Flash, SDRAM, SRAM), even when it consists of several 5171physical memory banks. 5172 5173U-Boot is installed in the first 128 kB of the first Flash bank (on 5174TQM8xxL modules this is the range 0x40000000 ... 0x4001FFFF). After 5175booting and sizing and initializing DRAM, the code relocates itself 5176to the upper end of DRAM. Immediately below the U-Boot code some 5177memory is reserved for use by malloc() [see CONFIG_SYS_MALLOC_LEN 5178configuration setting]. Below that, a structure with global Board 5179Info data is placed, followed by the stack (growing downward). 5180 5181Additionally, some exception handler code is copied to the low 8 kB 5182of DRAM (0x00000000 ... 0x00001FFF). 5183 5184So a typical memory configuration with 16 MB of DRAM could look like 5185this: 5186 5187 0x0000 0000 Exception Vector code 5188 : 5189 0x0000 1FFF 5190 0x0000 2000 Free for Application Use 5191 : 5192 : 5193 5194 : 5195 : 5196 0x00FB FF20 Monitor Stack (Growing downward) 5197 0x00FB FFAC Board Info Data and permanent copy of global data 5198 0x00FC 0000 Malloc Arena 5199 : 5200 0x00FD FFFF 5201 0x00FE 0000 RAM Copy of Monitor Code 5202 ... eventually: LCD or video framebuffer 5203 ... eventually: pRAM (Protected RAM - unchanged by reset) 5204 0x00FF FFFF [End of RAM] 5205 5206 5207System Initialization: 5208---------------------- 5209 5210In the reset configuration, U-Boot starts at the reset entry point 5211(on most PowerPC systems at address 0x00000100). Because of the reset 5212configuration for CS0# this is a mirror of the on board Flash memory. 5213To be able to re-map memory U-Boot then jumps to its link address. 5214To be able to implement the initialization code in C, a (small!) 5215initial stack is set up in the internal Dual Ported RAM (in case CPUs 5216which provide such a feature like), or in a locked part of the data 5217cache. After that, U-Boot initializes the CPU core, the caches and 5218the SIU. 5219 5220Next, all (potentially) available memory banks are mapped using a 5221preliminary mapping. For example, we put them on 512 MB boundaries 5222(multiples of 0x20000000: SDRAM on 0x00000000 and 0x20000000, Flash 5223on 0x40000000 and 0x60000000, SRAM on 0x80000000). Then UPM A is 5224programmed for SDRAM access. Using the temporary configuration, a 5225simple memory test is run that determines the size of the SDRAM 5226banks. 5227 5228When there is more than one SDRAM bank, and the banks are of 5229different size, the largest is mapped first. For equal size, the first 5230bank (CS2#) is mapped first. The first mapping is always for address 52310x00000000, with any additional banks following immediately to create 5232contiguous memory starting from 0. 5233 5234Then, the monitor installs itself at the upper end of the SDRAM area 5235and allocates memory for use by malloc() and for the global Board 5236Info data; also, the exception vector code is copied to the low RAM 5237pages, and the final stack is set up. 5238 5239Only after this relocation will you have a "normal" C environment; 5240until that you are restricted in several ways, mostly because you are 5241running from ROM, and because the code will have to be relocated to a 5242new address in RAM. 5243 5244 5245U-Boot Porting Guide: 5246---------------------- 5247 5248[Based on messages by Jerry Van Baren in the U-Boot-Users mailing 5249list, October 2002] 5250 5251 5252int main(int argc, char *argv[]) 5253{ 5254 sighandler_t no_more_time; 5255 5256 signal(SIGALRM, no_more_time); 5257 alarm(PROJECT_DEADLINE - toSec (3 * WEEK)); 5258 5259 if (available_money > available_manpower) { 5260 Pay consultant to port U-Boot; 5261 return 0; 5262 } 5263 5264 Download latest U-Boot source; 5265 5266 Subscribe to u-boot mailing list; 5267 5268 if (clueless) 5269 email("Hi, I am new to U-Boot, how do I get started?"); 5270 5271 while (learning) { 5272 Read the README file in the top level directory; 5273 Read http://www.denx.de/twiki/bin/view/DULG/Manual; 5274 Read applicable doc/*.README; 5275 Read the source, Luke; 5276 /* find . -name "*.[chS]" | xargs grep -i <keyword> */ 5277 } 5278 5279 if (available_money > toLocalCurrency ($2500)) 5280 Buy a BDI3000; 5281 else 5282 Add a lot of aggravation and time; 5283 5284 if (a similar board exists) { /* hopefully... */ 5285 cp -a board/<similar> board/<myboard> 5286 cp include/configs/<similar>.h include/configs/<myboard>.h 5287 } else { 5288 Create your own board support subdirectory; 5289 Create your own board include/configs/<myboard>.h file; 5290 } 5291 Edit new board/<myboard> files 5292 Edit new include/configs/<myboard>.h 5293 5294 while (!accepted) { 5295 while (!running) { 5296 do { 5297 Add / modify source code; 5298 } until (compiles); 5299 Debug; 5300 if (clueless) 5301 email("Hi, I am having problems..."); 5302 } 5303 Send patch file to the U-Boot email list; 5304 if (reasonable critiques) 5305 Incorporate improvements from email list code review; 5306 else 5307 Defend code as written; 5308 } 5309 5310 return 0; 5311} 5312 5313void no_more_time (int sig) 5314{ 5315 hire_a_guru(); 5316} 5317 5318 5319Coding Standards: 5320----------------- 5321 5322All contributions to U-Boot should conform to the Linux kernel 5323coding style; see the file "Documentation/CodingStyle" and the script 5324"scripts/Lindent" in your Linux kernel source directory. 5325 5326Source files originating from a different project (for example the 5327MTD subsystem) are generally exempt from these guidelines and are not 5328reformatted to ease subsequent migration to newer versions of those 5329sources. 5330 5331Please note that U-Boot is implemented in C (and to some small parts in 5332Assembler); no C++ is used, so please do not use C++ style comments (//) 5333in your code. 5334 5335Please also stick to the following formatting rules: 5336- remove any trailing white space 5337- use TAB characters for indentation and vertical alignment, not spaces 5338- make sure NOT to use DOS '\r\n' line feeds 5339- do not add more than 2 consecutive empty lines to source files 5340- do not add trailing empty lines to source files 5341 5342Submissions which do not conform to the standards may be returned 5343with a request to reformat the changes. 5344 5345 5346Submitting Patches: 5347------------------- 5348 5349Since the number of patches for U-Boot is growing, we need to 5350establish some rules. Submissions which do not conform to these rules 5351may be rejected, even when they contain important and valuable stuff. 5352 5353Please see http://www.denx.de/wiki/U-Boot/Patches for details. 5354 5355Patches shall be sent to the u-boot mailing list <u-boot@lists.denx.de>; 5356see http://lists.denx.de/mailman/listinfo/u-boot 5357 5358When you send a patch, please include the following information with 5359it: 5360 5361* For bug fixes: a description of the bug and how your patch fixes 5362 this bug. Please try to include a way of demonstrating that the 5363 patch actually fixes something. 5364 5365* For new features: a description of the feature and your 5366 implementation. 5367 5368* A CHANGELOG entry as plaintext (separate from the patch) 5369 5370* For major contributions, add a MAINTAINERS file with your 5371 information and associated file and directory references. 5372 5373* When you add support for a new board, don't forget to add a 5374 maintainer e-mail address to the boards.cfg file, too. 5375 5376* If your patch adds new configuration options, don't forget to 5377 document these in the README file. 5378 5379* The patch itself. If you are using git (which is *strongly* 5380 recommended) you can easily generate the patch using the 5381 "git format-patch". If you then use "git send-email" to send it to 5382 the U-Boot mailing list, you will avoid most of the common problems 5383 with some other mail clients. 5384 5385 If you cannot use git, use "diff -purN OLD NEW". If your version of 5386 diff does not support these options, then get the latest version of 5387 GNU diff. 5388 5389 The current directory when running this command shall be the parent 5390 directory of the U-Boot source tree (i. e. please make sure that 5391 your patch includes sufficient directory information for the 5392 affected files). 5393 5394 We prefer patches as plain text. MIME attachments are discouraged, 5395 and compressed attachments must not be used. 5396 5397* If one logical set of modifications affects or creates several 5398 files, all these changes shall be submitted in a SINGLE patch file. 5399 5400* Changesets that contain different, unrelated modifications shall be 5401 submitted as SEPARATE patches, one patch per changeset. 5402 5403 5404Notes: 5405 5406* Before sending the patch, run the buildman script on your patched 5407 source tree and make sure that no errors or warnings are reported 5408 for any of the boards. 5409 5410* Keep your modifications to the necessary minimum: A patch 5411 containing several unrelated changes or arbitrary reformats will be 5412 returned with a request to re-formatting / split it. 5413 5414* If you modify existing code, make sure that your new code does not 5415 add to the memory footprint of the code ;-) Small is beautiful! 5416 When adding new features, these should compile conditionally only 5417 (using #ifdef), and the resulting code with the new feature 5418 disabled must not need more memory than the old code without your 5419 modification. 5420 5421* Remember that there is a size limit of 100 kB per message on the 5422 u-boot mailing list. Bigger patches will be moderated. If they are 5423 reasonable and not too big, they will be acknowledged. But patches 5424 bigger than the size limit should be avoided. 5425