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 /avr32 Files generic to AVR32 architecture 140 /m68k Files generic to m68k architecture 141 /microblaze Files generic to microblaze architecture 142 /mips Files generic to MIPS architecture 143 /nds32 Files generic to NDS32 architecture 144 /nios2 Files generic to Altera NIOS2 architecture 145 /openrisc Files generic to OpenRISC architecture 146 /powerpc Files generic to PowerPC architecture 147 /sandbox Files generic to HW-independent "sandbox" 148 /sh Files generic to SH architecture 149 /x86 Files generic to x86 architecture 150/api Machine/arch independent API for external apps 151/board Board dependent files 152/cmd U-Boot commands functions 153/common Misc architecture independent functions 154/configs Board default configuration files 155/disk Code for disk drive partition handling 156/doc Documentation (don't expect too much) 157/drivers Commonly used device drivers 158/dts Contains Makefile for building internal U-Boot fdt. 159/examples Example code for standalone applications, etc. 160/fs Filesystem code (cramfs, ext2, jffs2, etc.) 161/include Header Files 162/lib Library routines generic to all architectures 163/Licenses Various license files 164/net Networking code 165/post Power On Self Test 166/scripts Various build scripts and Makefiles 167/test Various unit test files 168/tools Tools to build S-Record or U-Boot images, etc. 169 170Software Configuration: 171======================= 172 173Configuration is usually done using C preprocessor defines; the 174rationale behind that is to avoid dead code whenever possible. 175 176There are two classes of configuration variables: 177 178* Configuration _OPTIONS_: 179 These are selectable by the user and have names beginning with 180 "CONFIG_". 181 182* Configuration _SETTINGS_: 183 These depend on the hardware etc. and should not be meddled with if 184 you don't know what you're doing; they have names beginning with 185 "CONFIG_SYS_". 186 187Previously, all configuration was done by hand, which involved creating 188symbolic links and editing configuration files manually. More recently, 189U-Boot has added the Kbuild infrastructure used by the Linux kernel, 190allowing you to use the "make menuconfig" command to configure your 191build. 192 193 194Selection of Processor Architecture and Board Type: 195--------------------------------------------------- 196 197For all supported boards there are ready-to-use default 198configurations available; just type "make <board_name>_defconfig". 199 200Example: For a TQM823L module type: 201 202 cd u-boot 203 make TQM823L_defconfig 204 205Note: If you're looking for the default configuration file for a board 206you're sure used to be there but is now missing, check the file 207doc/README.scrapyard for a list of no longer supported boards. 208 209Sandbox Environment: 210-------------------- 211 212U-Boot can be built natively to run on a Linux host using the 'sandbox' 213board. This allows feature development which is not board- or architecture- 214specific to be undertaken on a native platform. The sandbox is also used to 215run some of U-Boot's tests. 216 217See board/sandbox/README.sandbox for more details. 218 219 220Board Initialisation Flow: 221-------------------------- 222 223This is the intended start-up flow for boards. This should apply for both 224SPL and U-Boot proper (i.e. they both follow the same rules). 225 226Note: "SPL" stands for "Secondary Program Loader," which is explained in 227more detail later in this file. 228 229At present, SPL mostly uses a separate code path, but the function names 230and roles of each function are the same. Some boards or architectures 231may not conform to this. At least most ARM boards which use 232CONFIG_SPL_FRAMEWORK conform to this. 233 234Execution typically starts with an architecture-specific (and possibly 235CPU-specific) start.S file, such as: 236 237 - arch/arm/cpu/armv7/start.S 238 - arch/powerpc/cpu/mpc83xx/start.S 239 - arch/mips/cpu/start.S 240 241and so on. From there, three functions are called; the purpose and 242limitations of each of these functions are described below. 243 244lowlevel_init(): 245 - purpose: essential init to permit execution to reach board_init_f() 246 - no global_data or BSS 247 - there is no stack (ARMv7 may have one but it will soon be removed) 248 - must not set up SDRAM or use console 249 - must only do the bare minimum to allow execution to continue to 250 board_init_f() 251 - this is almost never needed 252 - return normally from this function 253 254board_init_f(): 255 - purpose: set up the machine ready for running board_init_r(): 256 i.e. SDRAM and serial UART 257 - global_data is available 258 - stack is in SRAM 259 - BSS is not available, so you cannot use global/static variables, 260 only stack variables and global_data 261 262 Non-SPL-specific notes: 263 - dram_init() is called to set up DRAM. If already done in SPL this 264 can do nothing 265 266 SPL-specific notes: 267 - you can override the entire board_init_f() function with your own 268 version as needed. 269 - preloader_console_init() can be called here in extremis 270 - should set up SDRAM, and anything needed to make the UART work 271 - these is no need to clear BSS, it will be done by crt0.S 272 - must return normally from this function (don't call board_init_r() 273 directly) 274 275Here the BSS is cleared. For SPL, if CONFIG_SPL_STACK_R is defined, then at 276this point the stack and global_data are relocated to below 277CONFIG_SPL_STACK_R_ADDR. For non-SPL, U-Boot is relocated to run at the top of 278memory. 279 280board_init_r(): 281 - purpose: main execution, common code 282 - global_data is available 283 - SDRAM is available 284 - BSS is available, all static/global variables can be used 285 - execution eventually continues to main_loop() 286 287 Non-SPL-specific notes: 288 - U-Boot is relocated to the top of memory and is now running from 289 there. 290 291 SPL-specific notes: 292 - stack is optionally in SDRAM, if CONFIG_SPL_STACK_R is defined and 293 CONFIG_SPL_STACK_R_ADDR points into SDRAM 294 - preloader_console_init() can be called here - typically this is 295 done by defining CONFIG_SPL_BOARD_INIT and then supplying a 296 spl_board_init() function containing this call 297 - loads U-Boot or (in falcon mode) Linux 298 299 300 301Configuration Options: 302---------------------- 303 304Configuration depends on the combination of board and CPU type; all 305such information is kept in a configuration file 306"include/configs/<board_name>.h". 307 308Example: For a TQM823L module, all configuration settings are in 309"include/configs/TQM823L.h". 310 311 312Many of the options are named exactly as the corresponding Linux 313kernel configuration options. The intention is to make it easier to 314build a config tool - later. 315 316 317The following options need to be configured: 318 319- CPU Type: Define exactly one, e.g. CONFIG_MPC85XX. 320 321- Board Type: Define exactly one, e.g. CONFIG_MPC8540ADS. 322 323- CPU Daughterboard Type: (if CONFIG_ATSTK1000 is defined) 324 Define exactly one, e.g. CONFIG_ATSTK1002 325 326- Marvell Family Member 327 CONFIG_SYS_MVFS - define it if you want to enable 328 multiple fs option at one time 329 for marvell soc family 330 331- 8xx CPU Options: (if using an MPC8xx CPU) 332 CONFIG_8xx_GCLK_FREQ - deprecated: CPU clock if 333 get_gclk_freq() cannot work 334 e.g. if there is no 32KHz 335 reference PIT/RTC clock 336 CONFIG_8xx_OSCLK - PLL input clock (either EXTCLK 337 or XTAL/EXTAL) 338 339- 859/866/885 CPU options: (if using a MPC859 or MPC866 or MPC885 CPU): 340 CONFIG_SYS_8xx_CPUCLK_MIN 341 CONFIG_SYS_8xx_CPUCLK_MAX 342 CONFIG_8xx_CPUCLK_DEFAULT 343 See doc/README.MPC866 344 345 CONFIG_SYS_MEASURE_CPUCLK 346 347 Define this to measure the actual CPU clock instead 348 of relying on the correctness of the configured 349 values. Mostly useful for board bringup to make sure 350 the PLL is locked at the intended frequency. Note 351 that this requires a (stable) reference clock (32 kHz 352 RTC clock or CONFIG_SYS_8XX_XIN) 353 354 CONFIG_SYS_DELAYED_ICACHE 355 356 Define this option if you want to enable the 357 ICache only when Code runs from RAM. 358 359- 85xx CPU Options: 360 CONFIG_SYS_PPC64 361 362 Specifies that the core is a 64-bit PowerPC implementation (implements 363 the "64" category of the Power ISA). This is necessary for ePAPR 364 compliance, among other possible reasons. 365 366 CONFIG_SYS_FSL_TBCLK_DIV 367 368 Defines the core time base clock divider ratio compared to the 369 system clock. On most PQ3 devices this is 8, on newer QorIQ 370 devices it can be 16 or 32. The ratio varies from SoC to Soc. 371 372 CONFIG_SYS_FSL_PCIE_COMPAT 373 374 Defines the string to utilize when trying to match PCIe device 375 tree nodes for the given platform. 376 377 CONFIG_SYS_FSL_ERRATUM_A004510 378 379 Enables a workaround for erratum A004510. If set, 380 then CONFIG_SYS_FSL_ERRATUM_A004510_SVR_REV and 381 CONFIG_SYS_FSL_CORENET_SNOOPVEC_COREONLY must be set. 382 383 CONFIG_SYS_FSL_ERRATUM_A004510_SVR_REV 384 CONFIG_SYS_FSL_ERRATUM_A004510_SVR_REV2 (optional) 385 386 Defines one or two SoC revisions (low 8 bits of SVR) 387 for which the A004510 workaround should be applied. 388 389 The rest of SVR is either not relevant to the decision 390 of whether the erratum is present (e.g. p2040 versus 391 p2041) or is implied by the build target, which controls 392 whether CONFIG_SYS_FSL_ERRATUM_A004510 is set. 393 394 See Freescale App Note 4493 for more information about 395 this erratum. 396 397 CONFIG_A003399_NOR_WORKAROUND 398 Enables a workaround for IFC erratum A003399. It is only 399 required during NOR boot. 400 401 CONFIG_A008044_WORKAROUND 402 Enables a workaround for T1040/T1042 erratum A008044. It is only 403 required during NAND boot and valid for Rev 1.0 SoC revision 404 405 CONFIG_SYS_FSL_CORENET_SNOOPVEC_COREONLY 406 407 This is the value to write into CCSR offset 0x18600 408 according to the A004510 workaround. 409 410 CONFIG_SYS_FSL_DSP_DDR_ADDR 411 This value denotes start offset of DDR memory which is 412 connected exclusively to the DSP cores. 413 414 CONFIG_SYS_FSL_DSP_M2_RAM_ADDR 415 This value denotes start offset of M2 memory 416 which is directly connected to the DSP core. 417 418 CONFIG_SYS_FSL_DSP_M3_RAM_ADDR 419 This value denotes start offset of M3 memory which is directly 420 connected to the DSP core. 421 422 CONFIG_SYS_FSL_DSP_CCSRBAR_DEFAULT 423 This value denotes start offset of DSP CCSR space. 424 425 CONFIG_SYS_FSL_SINGLE_SOURCE_CLK 426 Single Source Clock is clocking mode present in some of FSL SoC's. 427 In this mode, a single differential clock is used to supply 428 clocks to the sysclock, ddrclock and usbclock. 429 430 CONFIG_SYS_CPC_REINIT_F 431 This CONFIG is defined when the CPC is configured as SRAM at the 432 time of U-Boot entry and is required to be re-initialized. 433 434 CONFIG_DEEP_SLEEP 435 Indicates this SoC supports deep sleep feature. If deep sleep is 436 supported, core will start to execute uboot when wakes up. 437 438- Generic CPU options: 439 CONFIG_SYS_GENERIC_GLOBAL_DATA 440 Defines global data is initialized in generic board board_init_f(). 441 If this macro is defined, global data is created and cleared in 442 generic board board_init_f(). Without this macro, architecture/board 443 should initialize global data before calling board_init_f(). 444 445 CONFIG_SYS_BIG_ENDIAN, CONFIG_SYS_LITTLE_ENDIAN 446 447 Defines the endianess of the CPU. Implementation of those 448 values is arch specific. 449 450 CONFIG_SYS_FSL_DDR 451 Freescale DDR driver in use. This type of DDR controller is 452 found in mpc83xx, mpc85xx, mpc86xx as well as some ARM core 453 SoCs. 454 455 CONFIG_SYS_FSL_DDR_ADDR 456 Freescale DDR memory-mapped register base. 457 458 CONFIG_SYS_FSL_DDR_EMU 459 Specify emulator support for DDR. Some DDR features such as 460 deskew training are not available. 461 462 CONFIG_SYS_FSL_DDRC_GEN1 463 Freescale DDR1 controller. 464 465 CONFIG_SYS_FSL_DDRC_GEN2 466 Freescale DDR2 controller. 467 468 CONFIG_SYS_FSL_DDRC_GEN3 469 Freescale DDR3 controller. 470 471 CONFIG_SYS_FSL_DDRC_GEN4 472 Freescale DDR4 controller. 473 474 CONFIG_SYS_FSL_DDRC_ARM_GEN3 475 Freescale DDR3 controller for ARM-based SoCs. 476 477 CONFIG_SYS_FSL_DDR1 478 Board config to use DDR1. It can be enabled for SoCs with 479 Freescale DDR1 or DDR2 controllers, depending on the board 480 implemetation. 481 482 CONFIG_SYS_FSL_DDR2 483 Board config to use DDR2. It can be enabled for SoCs with 484 Freescale DDR2 or DDR3 controllers, depending on the board 485 implementation. 486 487 CONFIG_SYS_FSL_DDR3 488 Board config to use DDR3. It can be enabled for SoCs with 489 Freescale DDR3 or DDR3L controllers. 490 491 CONFIG_SYS_FSL_DDR3L 492 Board config to use DDR3L. It can be enabled for SoCs with 493 DDR3L controllers. 494 495 CONFIG_SYS_FSL_DDR4 496 Board config to use DDR4. It can be enabled for SoCs with 497 DDR4 controllers. 498 499 CONFIG_SYS_FSL_IFC_BE 500 Defines the IFC controller register space as Big Endian 501 502 CONFIG_SYS_FSL_IFC_LE 503 Defines the IFC controller register space as Little Endian 504 505 CONFIG_SYS_FSL_IFC_CLK_DIV 506 Defines divider of platform clock(clock input to IFC controller). 507 508 CONFIG_SYS_FSL_LBC_CLK_DIV 509 Defines divider of platform clock(clock input to eLBC controller). 510 511 CONFIG_SYS_FSL_PBL_PBI 512 It enables addition of RCW (Power on reset configuration) in built image. 513 Please refer doc/README.pblimage for more details 514 515 CONFIG_SYS_FSL_PBL_RCW 516 It adds PBI(pre-boot instructions) commands in u-boot build image. 517 PBI commands can be used to configure SoC before it starts the execution. 518 Please refer doc/README.pblimage for more details 519 520 CONFIG_SPL_FSL_PBL 521 It adds a target to create boot binary having SPL binary in PBI format 522 concatenated with u-boot binary. 523 524 CONFIG_SYS_FSL_DDR_BE 525 Defines the DDR controller register space as Big Endian 526 527 CONFIG_SYS_FSL_DDR_LE 528 Defines the DDR controller register space as Little Endian 529 530 CONFIG_SYS_FSL_DDR_SDRAM_BASE_PHY 531 Physical address from the view of DDR controllers. It is the 532 same as CONFIG_SYS_DDR_SDRAM_BASE for all Power SoCs. But 533 it could be different for ARM SoCs. 534 535 CONFIG_SYS_FSL_DDR_INTLV_256B 536 DDR controller interleaving on 256-byte. This is a special 537 interleaving mode, handled by Dickens for Freescale layerscape 538 SoCs with ARM core. 539 540 CONFIG_SYS_FSL_DDR_MAIN_NUM_CTRLS 541 Number of controllers used as main memory. 542 543 CONFIG_SYS_FSL_OTHER_DDR_NUM_CTRLS 544 Number of controllers used for other than main memory. 545 546 CONFIG_SYS_FSL_HAS_DP_DDR 547 Defines the SoC has DP-DDR used for DPAA. 548 549 CONFIG_SYS_FSL_SEC_BE 550 Defines the SEC controller register space as Big Endian 551 552 CONFIG_SYS_FSL_SEC_LE 553 Defines the SEC controller register space as Little Endian 554 555- MIPS CPU options: 556 CONFIG_SYS_INIT_SP_OFFSET 557 558 Offset relative to CONFIG_SYS_SDRAM_BASE for initial stack 559 pointer. This is needed for the temporary stack before 560 relocation. 561 562 CONFIG_SYS_MIPS_CACHE_MODE 563 564 Cache operation mode for the MIPS CPU. 565 See also arch/mips/include/asm/mipsregs.h. 566 Possible values are: 567 CONF_CM_CACHABLE_NO_WA 568 CONF_CM_CACHABLE_WA 569 CONF_CM_UNCACHED 570 CONF_CM_CACHABLE_NONCOHERENT 571 CONF_CM_CACHABLE_CE 572 CONF_CM_CACHABLE_COW 573 CONF_CM_CACHABLE_CUW 574 CONF_CM_CACHABLE_ACCELERATED 575 576 CONFIG_SYS_XWAY_EBU_BOOTCFG 577 578 Special option for Lantiq XWAY SoCs for booting from NOR flash. 579 See also arch/mips/cpu/mips32/start.S. 580 581 CONFIG_XWAY_SWAP_BYTES 582 583 Enable compilation of tools/xway-swap-bytes needed for Lantiq 584 XWAY SoCs for booting from NOR flash. The U-Boot image needs to 585 be swapped if a flash programmer is used. 586 587- ARM options: 588 CONFIG_SYS_EXCEPTION_VECTORS_HIGH 589 590 Select high exception vectors of the ARM core, e.g., do not 591 clear the V bit of the c1 register of CP15. 592 593 COUNTER_FREQUENCY 594 Generic timer clock source frequency. 595 596 COUNTER_FREQUENCY_REAL 597 Generic timer clock source frequency if the real clock is 598 different from COUNTER_FREQUENCY, and can only be determined 599 at run time. 600 601- Tegra SoC options: 602 CONFIG_TEGRA_SUPPORT_NON_SECURE 603 604 Support executing U-Boot in non-secure (NS) mode. Certain 605 impossible actions will be skipped if the CPU is in NS mode, 606 such as ARM architectural timer initialization. 607 608- Linux Kernel Interface: 609 CONFIG_CLOCKS_IN_MHZ 610 611 U-Boot stores all clock information in Hz 612 internally. For binary compatibility with older Linux 613 kernels (which expect the clocks passed in the 614 bd_info data to be in MHz) the environment variable 615 "clocks_in_mhz" can be defined so that U-Boot 616 converts clock data to MHZ before passing it to the 617 Linux kernel. 618 When CONFIG_CLOCKS_IN_MHZ is defined, a definition of 619 "clocks_in_mhz=1" is automatically included in the 620 default environment. 621 622 CONFIG_MEMSIZE_IN_BYTES [relevant for MIPS only] 623 624 When transferring memsize parameter to Linux, some versions 625 expect it to be in bytes, others in MB. 626 Define CONFIG_MEMSIZE_IN_BYTES to make it in bytes. 627 628 CONFIG_OF_LIBFDT 629 630 New kernel versions are expecting firmware settings to be 631 passed using flattened device trees (based on open firmware 632 concepts). 633 634 CONFIG_OF_LIBFDT 635 * New libfdt-based support 636 * Adds the "fdt" command 637 * The bootm command automatically updates the fdt 638 639 OF_CPU - The proper name of the cpus node (only required for 640 MPC512X and MPC5xxx based boards). 641 OF_SOC - The proper name of the soc node (only required for 642 MPC512X and MPC5xxx based boards). 643 OF_TBCLK - The timebase frequency. 644 OF_STDOUT_PATH - The path to the console device 645 646 boards with QUICC Engines require OF_QE to set UCC MAC 647 addresses 648 649 CONFIG_OF_BOARD_SETUP 650 651 Board code has addition modification that it wants to make 652 to the flat device tree before handing it off to the kernel 653 654 CONFIG_OF_SYSTEM_SETUP 655 656 Other code has addition modification that it wants to make 657 to the flat device tree before handing it off to the kernel. 658 This causes ft_system_setup() to be called before booting 659 the kernel. 660 661 CONFIG_OF_IDE_FIXUP 662 663 U-Boot can detect if an IDE device is present or not. 664 If not, and this new config option is activated, U-Boot 665 removes the ATA node from the DTS before booting Linux, 666 so the Linux IDE driver does not probe the device and 667 crash. This is needed for buggy hardware (uc101) where 668 no pull down resistor is connected to the signal IDE5V_DD7. 669 670 CONFIG_MACH_TYPE [relevant for ARM only][mandatory] 671 672 This setting is mandatory for all boards that have only one 673 machine type and must be used to specify the machine type 674 number as it appears in the ARM machine registry 675 (see http://www.arm.linux.org.uk/developer/machines/). 676 Only boards that have multiple machine types supported 677 in a single configuration file and the machine type is 678 runtime discoverable, do not have to use this setting. 679 680- vxWorks boot parameters: 681 682 bootvx constructs a valid bootline using the following 683 environments variables: bootdev, bootfile, ipaddr, netmask, 684 serverip, gatewayip, hostname, othbootargs. 685 It loads the vxWorks image pointed bootfile. 686 687 Note: If a "bootargs" environment is defined, it will overwride 688 the defaults discussed just above. 689 690- Cache Configuration: 691 CONFIG_SYS_ICACHE_OFF - Do not enable instruction cache in U-Boot 692 CONFIG_SYS_DCACHE_OFF - Do not enable data cache in U-Boot 693 CONFIG_SYS_L2CACHE_OFF- Do not enable L2 cache in U-Boot 694 695- Cache Configuration for ARM: 696 CONFIG_SYS_L2_PL310 - Enable support for ARM PL310 L2 cache 697 controller 698 CONFIG_SYS_PL310_BASE - Physical base address of PL310 699 controller register space 700 701- Serial Ports: 702 CONFIG_PL010_SERIAL 703 704 Define this if you want support for Amba PrimeCell PL010 UARTs. 705 706 CONFIG_PL011_SERIAL 707 708 Define this if you want support for Amba PrimeCell PL011 UARTs. 709 710 CONFIG_PL011_CLOCK 711 712 If you have Amba PrimeCell PL011 UARTs, set this variable to 713 the clock speed of the UARTs. 714 715 CONFIG_PL01x_PORTS 716 717 If you have Amba PrimeCell PL010 or PL011 UARTs on your board, 718 define this to a list of base addresses for each (supported) 719 port. See e.g. include/configs/versatile.h 720 721 CONFIG_SERIAL_HW_FLOW_CONTROL 722 723 Define this variable to enable hw flow control in serial driver. 724 Current user of this option is drivers/serial/nsl16550.c driver 725 726- Console Interface: 727 Depending on board, define exactly one serial port 728 (like CONFIG_8xx_CONS_SMC1, CONFIG_8xx_CONS_SMC2, 729 CONFIG_8xx_CONS_SCC1, ...), or switch off the serial 730 console by defining CONFIG_8xx_CONS_NONE 731 732 Note: if CONFIG_8xx_CONS_NONE is defined, the serial 733 port routines must be defined elsewhere 734 (i.e. serial_init(), serial_getc(), ...) 735 736- Console Baudrate: 737 CONFIG_BAUDRATE - in bps 738 Select one of the baudrates listed in 739 CONFIG_SYS_BAUDRATE_TABLE, see below. 740 CONFIG_SYS_BRGCLK_PRESCALE, baudrate prescale 741 742- Console Rx buffer length 743 With CONFIG_SYS_SMC_RXBUFLEN it is possible to define 744 the maximum receive buffer length for the SMC. 745 This option is actual only for 82xx and 8xx possible. 746 If using CONFIG_SYS_SMC_RXBUFLEN also CONFIG_SYS_MAXIDLE 747 must be defined, to setup the maximum idle timeout for 748 the SMC. 749 750- Autoboot Command: 751 CONFIG_BOOTCOMMAND 752 Only needed when CONFIG_BOOTDELAY is enabled; 753 define a command string that is automatically executed 754 when no character is read on the console interface 755 within "Boot Delay" after reset. 756 757 CONFIG_BOOTARGS 758 This can be used to pass arguments to the bootm 759 command. The value of CONFIG_BOOTARGS goes into the 760 environment value "bootargs". 761 762 CONFIG_RAMBOOT and CONFIG_NFSBOOT 763 The value of these goes into the environment as 764 "ramboot" and "nfsboot" respectively, and can be used 765 as a convenience, when switching between booting from 766 RAM and NFS. 767 768- Bootcount: 769 CONFIG_BOOTCOUNT_LIMIT 770 Implements a mechanism for detecting a repeating reboot 771 cycle, see: 772 http://www.denx.de/wiki/view/DULG/UBootBootCountLimit 773 774 CONFIG_BOOTCOUNT_ENV 775 If no softreset save registers are found on the hardware 776 "bootcount" is stored in the environment. To prevent a 777 saveenv on all reboots, the environment variable 778 "upgrade_available" is used. If "upgrade_available" is 779 0, "bootcount" is always 0, if "upgrade_available" is 780 1 "bootcount" is incremented in the environment. 781 So the Userspace Applikation must set the "upgrade_available" 782 and "bootcount" variable to 0, if a boot was successfully. 783 784- Pre-Boot Commands: 785 CONFIG_PREBOOT 786 787 When this option is #defined, the existence of the 788 environment variable "preboot" will be checked 789 immediately before starting the CONFIG_BOOTDELAY 790 countdown and/or running the auto-boot command resp. 791 entering interactive mode. 792 793 This feature is especially useful when "preboot" is 794 automatically generated or modified. For an example 795 see the LWMON board specific code: here "preboot" is 796 modified when the user holds down a certain 797 combination of keys on the (special) keyboard when 798 booting the systems 799 800- Serial Download Echo Mode: 801 CONFIG_LOADS_ECHO 802 If defined to 1, all characters received during a 803 serial download (using the "loads" command) are 804 echoed back. This might be needed by some terminal 805 emulations (like "cu"), but may as well just take 806 time on others. This setting #define's the initial 807 value of the "loads_echo" environment variable. 808 809- Kgdb Serial Baudrate: (if CONFIG_CMD_KGDB is defined) 810 CONFIG_KGDB_BAUDRATE 811 Select one of the baudrates listed in 812 CONFIG_SYS_BAUDRATE_TABLE, see below. 813 814- Monitor Functions: 815 Monitor commands can be included or excluded 816 from the build by using the #include files 817 <config_cmd_all.h> and #undef'ing unwanted 818 commands, or adding #define's for wanted commands. 819 820 The default command configuration includes all commands 821 except those marked below with a "*". 822 823 CONFIG_CMD_AES AES 128 CBC encrypt/decrypt 824 CONFIG_CMD_ASKENV * ask for env variable 825 CONFIG_CMD_BDI bdinfo 826 CONFIG_CMD_BOOTD bootd 827 CONFIG_CMD_BOOTI * ARM64 Linux kernel Image support 828 CONFIG_CMD_CACHE * icache, dcache 829 CONFIG_CMD_CONSOLE coninfo 830 CONFIG_CMD_CRC32 * crc32 831 CONFIG_CMD_DHCP * DHCP support 832 CONFIG_CMD_DIAG * Diagnostics 833 CONFIG_CMD_DS4510 * ds4510 I2C gpio commands 834 CONFIG_CMD_DS4510_INFO * ds4510 I2C info command 835 CONFIG_CMD_DS4510_MEM * ds4510 I2C eeprom/sram commansd 836 CONFIG_CMD_DS4510_RST * ds4510 I2C rst command 837 CONFIG_CMD_DTT * Digital Therm and Thermostat 838 CONFIG_CMD_ECHO echo arguments 839 CONFIG_CMD_EDITENV edit env variable 840 CONFIG_CMD_EEPROM * EEPROM read/write support 841 CONFIG_CMD_EEPROM_LAYOUT* EEPROM layout aware commands 842 CONFIG_CMD_ELF * bootelf, bootvx 843 CONFIG_CMD_ENV_CALLBACK * display details about env callbacks 844 CONFIG_CMD_ENV_FLAGS * display details about env flags 845 CONFIG_CMD_ENV_EXISTS * check existence of env variable 846 CONFIG_CMD_EXPORTENV * export the environment 847 CONFIG_CMD_EXT2 * ext2 command support 848 CONFIG_CMD_EXT4 * ext4 command support 849 CONFIG_CMD_FS_GENERIC * filesystem commands (e.g. load, ls) 850 that work for multiple fs types 851 CONFIG_CMD_FS_UUID * Look up a filesystem UUID 852 CONFIG_CMD_SAVEENV saveenv 853 CONFIG_CMD_FDC * Floppy Disk Support 854 CONFIG_CMD_FAT * FAT command support 855 CONFIG_CMD_FLASH flinfo, erase, protect 856 CONFIG_CMD_FPGA FPGA device initialization support 857 CONFIG_CMD_FUSE * Device fuse support 858 CONFIG_CMD_GETTIME * Get time since boot 859 CONFIG_CMD_GO * the 'go' command (exec code) 860 CONFIG_CMD_GREPENV * search environment 861 CONFIG_CMD_HASH * calculate hash / digest 862 CONFIG_CMD_I2C * I2C serial bus support 863 CONFIG_CMD_IDE * IDE harddisk support 864 CONFIG_CMD_IMI iminfo 865 CONFIG_CMD_IMLS List all images found in NOR flash 866 CONFIG_CMD_IMLS_NAND * List all images found in NAND flash 867 CONFIG_CMD_IMMAP * IMMR dump support 868 CONFIG_CMD_IOTRACE * I/O tracing for debugging 869 CONFIG_CMD_IMPORTENV * import an environment 870 CONFIG_CMD_INI * import data from an ini file into the env 871 CONFIG_CMD_IRQ * irqinfo 872 CONFIG_CMD_ITEST Integer/string test of 2 values 873 CONFIG_CMD_JFFS2 * JFFS2 Support 874 CONFIG_CMD_KGDB * kgdb 875 CONFIG_CMD_LDRINFO * ldrinfo (display Blackfin loader) 876 CONFIG_CMD_LINK_LOCAL * link-local IP address auto-configuration 877 (169.254.*.*) 878 CONFIG_CMD_LOADB loadb 879 CONFIG_CMD_LOADS loads 880 CONFIG_CMD_MD5SUM * print md5 message digest 881 (requires CONFIG_CMD_MEMORY and CONFIG_MD5) 882 CONFIG_CMD_MEMINFO * Display detailed memory information 883 CONFIG_CMD_MEMORY md, mm, nm, mw, cp, cmp, crc, base, 884 loop, loopw 885 CONFIG_CMD_MEMTEST * mtest 886 CONFIG_CMD_MISC Misc functions like sleep etc 887 CONFIG_CMD_MMC * MMC memory mapped support 888 CONFIG_CMD_MII * MII utility commands 889 CONFIG_CMD_MTDPARTS * MTD partition support 890 CONFIG_CMD_NAND * NAND support 891 CONFIG_CMD_NET bootp, tftpboot, rarpboot 892 CONFIG_CMD_NFS NFS support 893 CONFIG_CMD_PCA953X * PCA953x I2C gpio commands 894 CONFIG_CMD_PCA953X_INFO * PCA953x I2C gpio info command 895 CONFIG_CMD_PCI * pciinfo 896 CONFIG_CMD_PCMCIA * PCMCIA support 897 CONFIG_CMD_PING * send ICMP ECHO_REQUEST to network 898 host 899 CONFIG_CMD_PORTIO * Port I/O 900 CONFIG_CMD_READ * Read raw data from partition 901 CONFIG_CMD_REGINFO * Register dump 902 CONFIG_CMD_RUN run command in env variable 903 CONFIG_CMD_SANDBOX * sb command to access sandbox features 904 CONFIG_CMD_SAVES * save S record dump 905 CONFIG_SCSI * SCSI Support 906 CONFIG_CMD_SDRAM * print SDRAM configuration information 907 (requires CONFIG_CMD_I2C) 908 CONFIG_CMD_SETGETDCR Support for DCR Register access 909 (4xx only) 910 CONFIG_CMD_SF * Read/write/erase SPI NOR flash 911 CONFIG_CMD_SHA1SUM * print sha1 memory digest 912 (requires CONFIG_CMD_MEMORY) 913 CONFIG_CMD_SOFTSWITCH * Soft switch setting command for BF60x 914 CONFIG_CMD_SOURCE "source" command Support 915 CONFIG_CMD_SPI * SPI serial bus support 916 CONFIG_CMD_TFTPSRV * TFTP transfer in server mode 917 CONFIG_CMD_TFTPPUT * TFTP put command (upload) 918 CONFIG_CMD_TIME * run command and report execution time (ARM specific) 919 CONFIG_CMD_TIMER * access to the system tick timer 920 CONFIG_CMD_USB * USB support 921 CONFIG_CMD_CDP * Cisco Discover Protocol support 922 CONFIG_CMD_MFSL * Microblaze FSL support 923 CONFIG_CMD_XIMG Load part of Multi Image 924 CONFIG_CMD_UUID * Generate random UUID or GUID string 925 926 EXAMPLE: If you want all functions except of network 927 support you can write: 928 929 #include "config_cmd_all.h" 930 #undef CONFIG_CMD_NET 931 932 Other Commands: 933 fdt (flattened device tree) command: CONFIG_OF_LIBFDT 934 935 Note: Don't enable the "icache" and "dcache" commands 936 (configuration option CONFIG_CMD_CACHE) unless you know 937 what you (and your U-Boot users) are doing. Data 938 cache cannot be enabled on systems like the 8xx or 939 8260 (where accesses to the IMMR region must be 940 uncached), and it cannot be disabled on all other 941 systems where we (mis-) use the data cache to hold an 942 initial stack and some data. 943 944 945 XXX - this list needs to get updated! 946 947- Removal of commands 948 If no commands are needed to boot, you can disable 949 CONFIG_CMDLINE to remove them. In this case, the command line 950 will not be available, and when U-Boot wants to execute the 951 boot command (on start-up) it will call board_run_command() 952 instead. This can reduce image size significantly for very 953 simple boot procedures. 954 955- Regular expression support: 956 CONFIG_REGEX 957 If this variable is defined, U-Boot is linked against 958 the SLRE (Super Light Regular Expression) library, 959 which adds regex support to some commands, as for 960 example "env grep" and "setexpr". 961 962- Device tree: 963 CONFIG_OF_CONTROL 964 If this variable is defined, U-Boot will use a device tree 965 to configure its devices, instead of relying on statically 966 compiled #defines in the board file. This option is 967 experimental and only available on a few boards. The device 968 tree is available in the global data as gd->fdt_blob. 969 970 U-Boot needs to get its device tree from somewhere. This can 971 be done using one of the three options below: 972 973 CONFIG_OF_EMBED 974 If this variable is defined, U-Boot will embed a device tree 975 binary in its image. This device tree file should be in the 976 board directory and called <soc>-<board>.dts. The binary file 977 is then picked up in board_init_f() and made available through 978 the global data structure as gd->blob. 979 980 CONFIG_OF_SEPARATE 981 If this variable is defined, U-Boot will build a device tree 982 binary. It will be called u-boot.dtb. Architecture-specific 983 code will locate it at run-time. Generally this works by: 984 985 cat u-boot.bin u-boot.dtb >image.bin 986 987 and in fact, U-Boot does this for you, creating a file called 988 u-boot-dtb.bin which is useful in the common case. You can 989 still use the individual files if you need something more 990 exotic. 991 992 CONFIG_OF_BOARD 993 If this variable is defined, U-Boot will use the device tree 994 provided by the board at runtime instead of embedding one with 995 the image. Only boards defining board_fdt_blob_setup() support 996 this option (see include/fdtdec.h file). 997 998- Watchdog: 999 CONFIG_WATCHDOG 1000 If this variable is defined, it enables watchdog 1001 support for the SoC. There must be support in the SoC 1002 specific code for a watchdog. For the 8xx and 8260 1003 CPUs, the SIU Watchdog feature is enabled in the SYPCR 1004 register. When supported for a specific SoC is 1005 available, then no further board specific code should 1006 be needed to use it. 1007 1008 CONFIG_HW_WATCHDOG 1009 When using a watchdog circuitry external to the used 1010 SoC, then define this variable and provide board 1011 specific code for the "hw_watchdog_reset" function. 1012 1013 CONFIG_AT91_HW_WDT_TIMEOUT 1014 specify the timeout in seconds. default 2 seconds. 1015 1016- U-Boot Version: 1017 CONFIG_VERSION_VARIABLE 1018 If this variable is defined, an environment variable 1019 named "ver" is created by U-Boot showing the U-Boot 1020 version as printed by the "version" command. 1021 Any change to this variable will be reverted at the 1022 next reset. 1023 1024- Real-Time Clock: 1025 1026 When CONFIG_CMD_DATE is selected, the type of the RTC 1027 has to be selected, too. Define exactly one of the 1028 following options: 1029 1030 CONFIG_RTC_MPC8xx - use internal RTC of MPC8xx 1031 CONFIG_RTC_PCF8563 - use Philips PCF8563 RTC 1032 CONFIG_RTC_MC13XXX - use MC13783 or MC13892 RTC 1033 CONFIG_RTC_MC146818 - use MC146818 RTC 1034 CONFIG_RTC_DS1307 - use Maxim, Inc. DS1307 RTC 1035 CONFIG_RTC_DS1337 - use Maxim, Inc. DS1337 RTC 1036 CONFIG_RTC_DS1338 - use Maxim, Inc. DS1338 RTC 1037 CONFIG_RTC_DS1339 - use Maxim, Inc. DS1339 RTC 1038 CONFIG_RTC_DS164x - use Dallas DS164x RTC 1039 CONFIG_RTC_ISL1208 - use Intersil ISL1208 RTC 1040 CONFIG_RTC_MAX6900 - use Maxim, Inc. MAX6900 RTC 1041 CONFIG_SYS_RTC_DS1337_NOOSC - Turn off the OSC output for DS1337 1042 CONFIG_SYS_RV3029_TCR - enable trickle charger on 1043 RV3029 RTC. 1044 1045 Note that if the RTC uses I2C, then the I2C interface 1046 must also be configured. See I2C Support, below. 1047 1048- GPIO Support: 1049 CONFIG_PCA953X - use NXP's PCA953X series I2C GPIO 1050 1051 The CONFIG_SYS_I2C_PCA953X_WIDTH option specifies a list of 1052 chip-ngpio pairs that tell the PCA953X driver the number of 1053 pins supported by a particular chip. 1054 1055 Note that if the GPIO device uses I2C, then the I2C interface 1056 must also be configured. See I2C Support, below. 1057 1058- I/O tracing: 1059 When CONFIG_IO_TRACE is selected, U-Boot intercepts all I/O 1060 accesses and can checksum them or write a list of them out 1061 to memory. See the 'iotrace' command for details. This is 1062 useful for testing device drivers since it can confirm that 1063 the driver behaves the same way before and after a code 1064 change. Currently this is supported on sandbox and arm. To 1065 add support for your architecture, add '#include <iotrace.h>' 1066 to the bottom of arch/<arch>/include/asm/io.h and test. 1067 1068 Example output from the 'iotrace stats' command is below. 1069 Note that if the trace buffer is exhausted, the checksum will 1070 still continue to operate. 1071 1072 iotrace is enabled 1073 Start: 10000000 (buffer start address) 1074 Size: 00010000 (buffer size) 1075 Offset: 00000120 (current buffer offset) 1076 Output: 10000120 (start + offset) 1077 Count: 00000018 (number of trace records) 1078 CRC32: 9526fb66 (CRC32 of all trace records) 1079 1080- Timestamp Support: 1081 1082 When CONFIG_TIMESTAMP is selected, the timestamp 1083 (date and time) of an image is printed by image 1084 commands like bootm or iminfo. This option is 1085 automatically enabled when you select CONFIG_CMD_DATE . 1086 1087- Partition Labels (disklabels) Supported: 1088 Zero or more of the following: 1089 CONFIG_MAC_PARTITION Apple's MacOS partition table. 1090 CONFIG_DOS_PARTITION MS Dos partition table, traditional on the 1091 Intel architecture, USB sticks, etc. 1092 CONFIG_ISO_PARTITION ISO partition table, used on CDROM etc. 1093 CONFIG_EFI_PARTITION GPT partition table, common when EFI is the 1094 bootloader. Note 2TB partition limit; see 1095 disk/part_efi.c 1096 CONFIG_MTD_PARTITIONS Memory Technology Device partition table. 1097 1098 If IDE or SCSI support is enabled (CONFIG_CMD_IDE or 1099 CONFIG_SCSI) you must configure support for at 1100 least one non-MTD partition type as well. 1101 1102- IDE Reset method: 1103 CONFIG_IDE_RESET_ROUTINE - this is defined in several 1104 board configurations files but used nowhere! 1105 1106 CONFIG_IDE_RESET - is this is defined, IDE Reset will 1107 be performed by calling the function 1108 ide_set_reset(int reset) 1109 which has to be defined in a board specific file 1110 1111- ATAPI Support: 1112 CONFIG_ATAPI 1113 1114 Set this to enable ATAPI support. 1115 1116- LBA48 Support 1117 CONFIG_LBA48 1118 1119 Set this to enable support for disks larger than 137GB 1120 Also look at CONFIG_SYS_64BIT_LBA. 1121 Whithout these , LBA48 support uses 32bit variables and will 'only' 1122 support disks up to 2.1TB. 1123 1124 CONFIG_SYS_64BIT_LBA: 1125 When enabled, makes the IDE subsystem use 64bit sector addresses. 1126 Default is 32bit. 1127 1128- SCSI Support: 1129 At the moment only there is only support for the 1130 SYM53C8XX SCSI controller; define 1131 CONFIG_SCSI_SYM53C8XX to enable it. 1132 1133 CONFIG_SYS_SCSI_MAX_LUN [8], CONFIG_SYS_SCSI_MAX_SCSI_ID [7] and 1134 CONFIG_SYS_SCSI_MAX_DEVICE [CONFIG_SYS_SCSI_MAX_SCSI_ID * 1135 CONFIG_SYS_SCSI_MAX_LUN] can be adjusted to define the 1136 maximum numbers of LUNs, SCSI ID's and target 1137 devices. 1138 CONFIG_SYS_SCSI_SYM53C8XX_CCF to fix clock timing (80Mhz) 1139 1140 The environment variable 'scsidevs' is set to the number of 1141 SCSI devices found during the last scan. 1142 1143- NETWORK Support (PCI): 1144 CONFIG_E1000 1145 Support for Intel 8254x/8257x gigabit chips. 1146 1147 CONFIG_E1000_SPI 1148 Utility code for direct access to the SPI bus on Intel 8257x. 1149 This does not do anything useful unless you set at least one 1150 of CONFIG_CMD_E1000 or CONFIG_E1000_SPI_GENERIC. 1151 1152 CONFIG_E1000_SPI_GENERIC 1153 Allow generic access to the SPI bus on the Intel 8257x, for 1154 example with the "sspi" command. 1155 1156 CONFIG_CMD_E1000 1157 Management command for E1000 devices. When used on devices 1158 with SPI support you can reprogram the EEPROM from U-Boot. 1159 1160 CONFIG_EEPRO100 1161 Support for Intel 82557/82559/82559ER chips. 1162 Optional CONFIG_EEPRO100_SROM_WRITE enables EEPROM 1163 write routine for first time initialisation. 1164 1165 CONFIG_TULIP 1166 Support for Digital 2114x chips. 1167 Optional CONFIG_TULIP_SELECT_MEDIA for board specific 1168 modem chip initialisation (KS8761/QS6611). 1169 1170 CONFIG_NATSEMI 1171 Support for National dp83815 chips. 1172 1173 CONFIG_NS8382X 1174 Support for National dp8382[01] gigabit chips. 1175 1176- NETWORK Support (other): 1177 1178 CONFIG_DRIVER_AT91EMAC 1179 Support for AT91RM9200 EMAC. 1180 1181 CONFIG_RMII 1182 Define this to use reduced MII inteface 1183 1184 CONFIG_DRIVER_AT91EMAC_QUIET 1185 If this defined, the driver is quiet. 1186 The driver doen't show link status messages. 1187 1188 CONFIG_CALXEDA_XGMAC 1189 Support for the Calxeda XGMAC device 1190 1191 CONFIG_LAN91C96 1192 Support for SMSC's LAN91C96 chips. 1193 1194 CONFIG_LAN91C96_USE_32_BIT 1195 Define this to enable 32 bit addressing 1196 1197 CONFIG_SMC91111 1198 Support for SMSC's LAN91C111 chip 1199 1200 CONFIG_SMC91111_BASE 1201 Define this to hold the physical address 1202 of the device (I/O space) 1203 1204 CONFIG_SMC_USE_32_BIT 1205 Define this if data bus is 32 bits 1206 1207 CONFIG_SMC_USE_IOFUNCS 1208 Define this to use i/o functions instead of macros 1209 (some hardware wont work with macros) 1210 1211 CONFIG_DRIVER_TI_EMAC 1212 Support for davinci emac 1213 1214 CONFIG_SYS_DAVINCI_EMAC_PHY_COUNT 1215 Define this if you have more then 3 PHYs. 1216 1217 CONFIG_FTGMAC100 1218 Support for Faraday's FTGMAC100 Gigabit SoC Ethernet 1219 1220 CONFIG_FTGMAC100_EGIGA 1221 Define this to use GE link update with gigabit PHY. 1222 Define this if FTGMAC100 is connected to gigabit PHY. 1223 If your system has 10/100 PHY only, it might not occur 1224 wrong behavior. Because PHY usually return timeout or 1225 useless data when polling gigabit status and gigabit 1226 control registers. This behavior won't affect the 1227 correctnessof 10/100 link speed update. 1228 1229 CONFIG_SMC911X 1230 Support for SMSC's LAN911x and LAN921x chips 1231 1232 CONFIG_SMC911X_BASE 1233 Define this to hold the physical address 1234 of the device (I/O space) 1235 1236 CONFIG_SMC911X_32_BIT 1237 Define this if data bus is 32 bits 1238 1239 CONFIG_SMC911X_16_BIT 1240 Define this if data bus is 16 bits. If your processor 1241 automatically converts one 32 bit word to two 16 bit 1242 words you may also try CONFIG_SMC911X_32_BIT. 1243 1244 CONFIG_SH_ETHER 1245 Support for Renesas on-chip Ethernet controller 1246 1247 CONFIG_SH_ETHER_USE_PORT 1248 Define the number of ports to be used 1249 1250 CONFIG_SH_ETHER_PHY_ADDR 1251 Define the ETH PHY's address 1252 1253 CONFIG_SH_ETHER_CACHE_WRITEBACK 1254 If this option is set, the driver enables cache flush. 1255 1256- PWM Support: 1257 CONFIG_PWM_IMX 1258 Support for PWM module on the imx6. 1259 1260- TPM Support: 1261 CONFIG_TPM 1262 Support TPM devices. 1263 1264 CONFIG_TPM_TIS_INFINEON 1265 Support for Infineon i2c bus TPM devices. Only one device 1266 per system is supported at this time. 1267 1268 CONFIG_TPM_TIS_I2C_BURST_LIMITATION 1269 Define the burst count bytes upper limit 1270 1271 CONFIG_TPM_ST33ZP24 1272 Support for STMicroelectronics TPM devices. Requires DM_TPM support. 1273 1274 CONFIG_TPM_ST33ZP24_I2C 1275 Support for STMicroelectronics ST33ZP24 I2C devices. 1276 Requires TPM_ST33ZP24 and I2C. 1277 1278 CONFIG_TPM_ST33ZP24_SPI 1279 Support for STMicroelectronics ST33ZP24 SPI devices. 1280 Requires TPM_ST33ZP24 and SPI. 1281 1282 CONFIG_TPM_ATMEL_TWI 1283 Support for Atmel TWI TPM device. Requires I2C support. 1284 1285 CONFIG_TPM_TIS_LPC 1286 Support for generic parallel port TPM devices. Only one device 1287 per system is supported at this time. 1288 1289 CONFIG_TPM_TIS_BASE_ADDRESS 1290 Base address where the generic TPM device is mapped 1291 to. Contemporary x86 systems usually map it at 1292 0xfed40000. 1293 1294 CONFIG_CMD_TPM 1295 Add tpm monitor functions. 1296 Requires CONFIG_TPM. If CONFIG_TPM_AUTH_SESSIONS is set, also 1297 provides monitor access to authorized functions. 1298 1299 CONFIG_TPM 1300 Define this to enable the TPM support library which provides 1301 functional interfaces to some TPM commands. 1302 Requires support for a TPM device. 1303 1304 CONFIG_TPM_AUTH_SESSIONS 1305 Define this to enable authorized functions in the TPM library. 1306 Requires CONFIG_TPM and CONFIG_SHA1. 1307 1308- USB Support: 1309 At the moment only the UHCI host controller is 1310 supported (PIP405, MIP405, MPC5200); define 1311 CONFIG_USB_UHCI to enable it. 1312 define CONFIG_USB_KEYBOARD to enable the USB Keyboard 1313 and define CONFIG_USB_STORAGE to enable the USB 1314 storage devices. 1315 Note: 1316 Supported are USB Keyboards and USB Floppy drives 1317 (TEAC FD-05PUB). 1318 MPC5200 USB requires additional defines: 1319 CONFIG_USB_CLOCK 1320 for 528 MHz Clock: 0x0001bbbb 1321 CONFIG_PSC3_USB 1322 for USB on PSC3 1323 CONFIG_USB_CONFIG 1324 for differential drivers: 0x00001000 1325 for single ended drivers: 0x00005000 1326 for differential drivers on PSC3: 0x00000100 1327 for single ended drivers on PSC3: 0x00004100 1328 CONFIG_SYS_USB_EVENT_POLL 1329 May be defined to allow interrupt polling 1330 instead of using asynchronous interrupts 1331 1332 CONFIG_USB_EHCI_TXFIFO_THRESH enables setting of the 1333 txfilltuning field in the EHCI controller on reset. 1334 1335 CONFIG_USB_DWC2_REG_ADDR the physical CPU address of the DWC2 1336 HW module registers. 1337 1338- USB Device: 1339 Define the below if you wish to use the USB console. 1340 Once firmware is rebuilt from a serial console issue the 1341 command "setenv stdin usbtty; setenv stdout usbtty" and 1342 attach your USB cable. The Unix command "dmesg" should print 1343 it has found a new device. The environment variable usbtty 1344 can be set to gserial or cdc_acm to enable your device to 1345 appear to a USB host as a Linux gserial device or a 1346 Common Device Class Abstract Control Model serial device. 1347 If you select usbtty = gserial you should be able to enumerate 1348 a Linux host by 1349 # modprobe usbserial vendor=0xVendorID product=0xProductID 1350 else if using cdc_acm, simply setting the environment 1351 variable usbtty to be cdc_acm should suffice. The following 1352 might be defined in YourBoardName.h 1353 1354 CONFIG_USB_DEVICE 1355 Define this to build a UDC device 1356 1357 CONFIG_USB_TTY 1358 Define this to have a tty type of device available to 1359 talk to the UDC device 1360 1361 CONFIG_USBD_HS 1362 Define this to enable the high speed support for usb 1363 device and usbtty. If this feature is enabled, a routine 1364 int is_usbd_high_speed(void) 1365 also needs to be defined by the driver to dynamically poll 1366 whether the enumeration has succeded at high speed or full 1367 speed. 1368 1369 CONFIG_SYS_CONSOLE_IS_IN_ENV 1370 Define this if you want stdin, stdout &/or stderr to 1371 be set to usbtty. 1372 1373 mpc8xx: 1374 CONFIG_SYS_USB_EXTC_CLK 0xBLAH 1375 Derive USB clock from external clock "blah" 1376 - CONFIG_SYS_USB_EXTC_CLK 0x02 1377 1378 If you have a USB-IF assigned VendorID then you may wish to 1379 define your own vendor specific values either in BoardName.h 1380 or directly in usbd_vendor_info.h. If you don't define 1381 CONFIG_USBD_MANUFACTURER, CONFIG_USBD_PRODUCT_NAME, 1382 CONFIG_USBD_VENDORID and CONFIG_USBD_PRODUCTID, then U-Boot 1383 should pretend to be a Linux device to it's target host. 1384 1385 CONFIG_USBD_MANUFACTURER 1386 Define this string as the name of your company for 1387 - CONFIG_USBD_MANUFACTURER "my company" 1388 1389 CONFIG_USBD_PRODUCT_NAME 1390 Define this string as the name of your product 1391 - CONFIG_USBD_PRODUCT_NAME "acme usb device" 1392 1393 CONFIG_USBD_VENDORID 1394 Define this as your assigned Vendor ID from the USB 1395 Implementors Forum. This *must* be a genuine Vendor ID 1396 to avoid polluting the USB namespace. 1397 - CONFIG_USBD_VENDORID 0xFFFF 1398 1399 CONFIG_USBD_PRODUCTID 1400 Define this as the unique Product ID 1401 for your device 1402 - CONFIG_USBD_PRODUCTID 0xFFFF 1403 1404- ULPI Layer Support: 1405 The ULPI (UTMI Low Pin (count) Interface) PHYs are supported via 1406 the generic ULPI layer. The generic layer accesses the ULPI PHY 1407 via the platform viewport, so you need both the genric layer and 1408 the viewport enabled. Currently only Chipidea/ARC based 1409 viewport is supported. 1410 To enable the ULPI layer support, define CONFIG_USB_ULPI and 1411 CONFIG_USB_ULPI_VIEWPORT in your board configuration file. 1412 If your ULPI phy needs a different reference clock than the 1413 standard 24 MHz then you have to define CONFIG_ULPI_REF_CLK to 1414 the appropriate value in Hz. 1415 1416- MMC Support: 1417 The MMC controller on the Intel PXA is supported. To 1418 enable this define CONFIG_MMC. The MMC can be 1419 accessed from the boot prompt by mapping the device 1420 to physical memory similar to flash. Command line is 1421 enabled with CONFIG_CMD_MMC. The MMC driver also works with 1422 the FAT fs. This is enabled with CONFIG_CMD_FAT. 1423 1424 CONFIG_SH_MMCIF 1425 Support for Renesas on-chip MMCIF controller 1426 1427 CONFIG_SH_MMCIF_ADDR 1428 Define the base address of MMCIF registers 1429 1430 CONFIG_SH_MMCIF_CLK 1431 Define the clock frequency for MMCIF 1432 1433 CONFIG_SUPPORT_EMMC_BOOT 1434 Enable some additional features of the eMMC boot partitions. 1435 1436 CONFIG_SUPPORT_EMMC_RPMB 1437 Enable the commands for reading, writing and programming the 1438 key for the Replay Protection Memory Block partition in eMMC. 1439 1440- USB Device Firmware Update (DFU) class support: 1441 CONFIG_USB_FUNCTION_DFU 1442 This enables the USB portion of the DFU USB class 1443 1444 CONFIG_CMD_DFU 1445 This enables the command "dfu" which is used to have 1446 U-Boot create a DFU class device via USB. This command 1447 requires that the "dfu_alt_info" environment variable be 1448 set and define the alt settings to expose to the host. 1449 1450 CONFIG_DFU_MMC 1451 This enables support for exposing (e)MMC devices via DFU. 1452 1453 CONFIG_DFU_NAND 1454 This enables support for exposing NAND devices via DFU. 1455 1456 CONFIG_DFU_RAM 1457 This enables support for exposing RAM via DFU. 1458 Note: DFU spec refer to non-volatile memory usage, but 1459 allow usages beyond the scope of spec - here RAM usage, 1460 one that would help mostly the developer. 1461 1462 CONFIG_SYS_DFU_DATA_BUF_SIZE 1463 Dfu transfer uses a buffer before writing data to the 1464 raw storage device. Make the size (in bytes) of this buffer 1465 configurable. The size of this buffer is also configurable 1466 through the "dfu_bufsiz" environment variable. 1467 1468 CONFIG_SYS_DFU_MAX_FILE_SIZE 1469 When updating files rather than the raw storage device, 1470 we use a static buffer to copy the file into and then write 1471 the buffer once we've been given the whole file. Define 1472 this to the maximum filesize (in bytes) for the buffer. 1473 Default is 4 MiB if undefined. 1474 1475 DFU_DEFAULT_POLL_TIMEOUT 1476 Poll timeout [ms], is the timeout a device can send to the 1477 host. The host must wait for this timeout before sending 1478 a subsequent DFU_GET_STATUS request to the device. 1479 1480 DFU_MANIFEST_POLL_TIMEOUT 1481 Poll timeout [ms], which the device sends to the host when 1482 entering dfuMANIFEST state. Host waits this timeout, before 1483 sending again an USB request to the device. 1484 1485- USB Device Android Fastboot support: 1486 CONFIG_USB_FUNCTION_FASTBOOT 1487 This enables the USB part of the fastboot gadget 1488 1489 CONFIG_CMD_FASTBOOT 1490 This enables the command "fastboot" which enables the Android 1491 fastboot mode for the platform's USB device. Fastboot is a USB 1492 protocol for downloading images, flashing and device control 1493 used on Android devices. 1494 See doc/README.android-fastboot for more information. 1495 1496 CONFIG_ANDROID_BOOT_IMAGE 1497 This enables support for booting images which use the Android 1498 image format header. 1499 1500 CONFIG_FASTBOOT_BUF_ADDR 1501 The fastboot protocol requires a large memory buffer for 1502 downloads. Define this to the starting RAM address to use for 1503 downloaded images. 1504 1505 CONFIG_FASTBOOT_BUF_SIZE 1506 The fastboot protocol requires a large memory buffer for 1507 downloads. This buffer should be as large as possible for a 1508 platform. Define this to the size available RAM for fastboot. 1509 1510 CONFIG_FASTBOOT_FLASH 1511 The fastboot protocol includes a "flash" command for writing 1512 the downloaded image to a non-volatile storage device. Define 1513 this to enable the "fastboot flash" command. 1514 1515 CONFIG_FASTBOOT_FLASH_MMC_DEV 1516 The fastboot "flash" command requires additional information 1517 regarding the non-volatile storage device. Define this to 1518 the eMMC device that fastboot should use to store the image. 1519 1520 CONFIG_FASTBOOT_GPT_NAME 1521 The fastboot "flash" command supports writing the downloaded 1522 image to the Protective MBR and the Primary GUID Partition 1523 Table. (Additionally, this downloaded image is post-processed 1524 to generate and write the Backup GUID Partition Table.) 1525 This occurs when the specified "partition name" on the 1526 "fastboot flash" command line matches this value. 1527 The default is "gpt" if undefined. 1528 1529 CONFIG_FASTBOOT_MBR_NAME 1530 The fastboot "flash" command supports writing the downloaded 1531 image to DOS MBR. 1532 This occurs when the "partition name" specified on the 1533 "fastboot flash" command line matches this value. 1534 If not defined the default value "mbr" is used. 1535 1536- Journaling Flash filesystem support: 1537 CONFIG_JFFS2_NAND 1538 Define these for a default partition on a NAND device 1539 1540 CONFIG_SYS_JFFS2_FIRST_SECTOR, 1541 CONFIG_SYS_JFFS2_FIRST_BANK, CONFIG_SYS_JFFS2_NUM_BANKS 1542 Define these for a default partition on a NOR device 1543 1544- FAT(File Allocation Table) filesystem write function support: 1545 CONFIG_FAT_WRITE 1546 1547 Define this to enable support for saving memory data as a 1548 file in FAT formatted partition. 1549 1550 This will also enable the command "fatwrite" enabling the 1551 user to write files to FAT. 1552 1553- FAT(File Allocation Table) filesystem cluster size: 1554 CONFIG_FS_FAT_MAX_CLUSTSIZE 1555 1556 Define the max cluster size for fat operations else 1557 a default value of 65536 will be defined. 1558 1559- Keyboard Support: 1560 See Kconfig help for available keyboard drivers. 1561 1562 CONFIG_KEYBOARD 1563 1564 Define this to enable a custom keyboard support. 1565 This simply calls drv_keyboard_init() which must be 1566 defined in your board-specific files. This option is deprecated 1567 and is only used by novena. For new boards, use driver model 1568 instead. 1569 1570- Video support: 1571 CONFIG_FSL_DIU_FB 1572 Enable the Freescale DIU video driver. Reference boards for 1573 SOCs that have a DIU should define this macro to enable DIU 1574 support, and should also define these other macros: 1575 1576 CONFIG_SYS_DIU_ADDR 1577 CONFIG_VIDEO 1578 CONFIG_CFB_CONSOLE 1579 CONFIG_VIDEO_SW_CURSOR 1580 CONFIG_VGA_AS_SINGLE_DEVICE 1581 CONFIG_VIDEO_LOGO 1582 CONFIG_VIDEO_BMP_LOGO 1583 1584 The DIU driver will look for the 'video-mode' environment 1585 variable, and if defined, enable the DIU as a console during 1586 boot. See the documentation file doc/README.video for a 1587 description of this variable. 1588 1589- LCD Support: CONFIG_LCD 1590 1591 Define this to enable LCD support (for output to LCD 1592 display); also select one of the supported displays 1593 by defining one of these: 1594 1595 CONFIG_ATMEL_LCD: 1596 1597 HITACHI TX09D70VM1CCA, 3.5", 240x320. 1598 1599 CONFIG_NEC_NL6448AC33: 1600 1601 NEC NL6448AC33-18. Active, color, single scan. 1602 1603 CONFIG_NEC_NL6448BC20 1604 1605 NEC NL6448BC20-08. 6.5", 640x480. 1606 Active, color, single scan. 1607 1608 CONFIG_NEC_NL6448BC33_54 1609 1610 NEC NL6448BC33-54. 10.4", 640x480. 1611 Active, color, single scan. 1612 1613 CONFIG_SHARP_16x9 1614 1615 Sharp 320x240. Active, color, single scan. 1616 It isn't 16x9, and I am not sure what it is. 1617 1618 CONFIG_SHARP_LQ64D341 1619 1620 Sharp LQ64D341 display, 640x480. 1621 Active, color, single scan. 1622 1623 CONFIG_HLD1045 1624 1625 HLD1045 display, 640x480. 1626 Active, color, single scan. 1627 1628 CONFIG_OPTREX_BW 1629 1630 Optrex CBL50840-2 NF-FW 99 22 M5 1631 or 1632 Hitachi LMG6912RPFC-00T 1633 or 1634 Hitachi SP14Q002 1635 1636 320x240. Black & white. 1637 1638 CONFIG_LCD_ALIGNMENT 1639 1640 Normally the LCD is page-aligned (typically 4KB). If this is 1641 defined then the LCD will be aligned to this value instead. 1642 For ARM it is sometimes useful to use MMU_SECTION_SIZE 1643 here, since it is cheaper to change data cache settings on 1644 a per-section basis. 1645 1646 1647 CONFIG_LCD_ROTATION 1648 1649 Sometimes, for example if the display is mounted in portrait 1650 mode or even if it's mounted landscape but rotated by 180degree, 1651 we need to rotate our content of the display relative to the 1652 framebuffer, so that user can read the messages which are 1653 printed out. 1654 Once CONFIG_LCD_ROTATION is defined, the lcd_console will be 1655 initialized with a given rotation from "vl_rot" out of 1656 "vidinfo_t" which is provided by the board specific code. 1657 The value for vl_rot is coded as following (matching to 1658 fbcon=rotate:<n> linux-kernel commandline): 1659 0 = no rotation respectively 0 degree 1660 1 = 90 degree rotation 1661 2 = 180 degree rotation 1662 3 = 270 degree rotation 1663 1664 If CONFIG_LCD_ROTATION is not defined, the console will be 1665 initialized with 0degree rotation. 1666 1667 CONFIG_LCD_BMP_RLE8 1668 1669 Support drawing of RLE8-compressed bitmaps on the LCD. 1670 1671 CONFIG_I2C_EDID 1672 1673 Enables an 'i2c edid' command which can read EDID 1674 information over I2C from an attached LCD display. 1675 1676- Splash Screen Support: CONFIG_SPLASH_SCREEN 1677 1678 If this option is set, the environment is checked for 1679 a variable "splashimage". If found, the usual display 1680 of logo, copyright and system information on the LCD 1681 is suppressed and the BMP image at the address 1682 specified in "splashimage" is loaded instead. The 1683 console is redirected to the "nulldev", too. This 1684 allows for a "silent" boot where a splash screen is 1685 loaded very quickly after power-on. 1686 1687 CONFIG_SPLASHIMAGE_GUARD 1688 1689 If this option is set, then U-Boot will prevent the environment 1690 variable "splashimage" from being set to a problematic address 1691 (see doc/README.displaying-bmps). 1692 This option is useful for targets where, due to alignment 1693 restrictions, an improperly aligned BMP image will cause a data 1694 abort. If you think you will not have problems with unaligned 1695 accesses (for example because your toolchain prevents them) 1696 there is no need to set this option. 1697 1698 CONFIG_SPLASH_SCREEN_ALIGN 1699 1700 If this option is set the splash image can be freely positioned 1701 on the screen. Environment variable "splashpos" specifies the 1702 position as "x,y". If a positive number is given it is used as 1703 number of pixel from left/top. If a negative number is given it 1704 is used as number of pixel from right/bottom. You can also 1705 specify 'm' for centering the image. 1706 1707 Example: 1708 setenv splashpos m,m 1709 => image at center of screen 1710 1711 setenv splashpos 30,20 1712 => image at x = 30 and y = 20 1713 1714 setenv splashpos -10,m 1715 => vertically centered image 1716 at x = dspWidth - bmpWidth - 9 1717 1718- Gzip compressed BMP image support: CONFIG_VIDEO_BMP_GZIP 1719 1720 If this option is set, additionally to standard BMP 1721 images, gzipped BMP images can be displayed via the 1722 splashscreen support or the bmp command. 1723 1724- Run length encoded BMP image (RLE8) support: CONFIG_VIDEO_BMP_RLE8 1725 1726 If this option is set, 8-bit RLE compressed BMP images 1727 can be displayed via the splashscreen support or the 1728 bmp command. 1729 1730- Compression support: 1731 CONFIG_GZIP 1732 1733 Enabled by default to support gzip compressed images. 1734 1735 CONFIG_BZIP2 1736 1737 If this option is set, support for bzip2 compressed 1738 images is included. If not, only uncompressed and gzip 1739 compressed images are supported. 1740 1741 NOTE: the bzip2 algorithm requires a lot of RAM, so 1742 the malloc area (as defined by CONFIG_SYS_MALLOC_LEN) should 1743 be at least 4MB. 1744 1745 CONFIG_LZMA 1746 1747 If this option is set, support for lzma compressed 1748 images is included. 1749 1750 Note: The LZMA algorithm adds between 2 and 4KB of code and it 1751 requires an amount of dynamic memory that is given by the 1752 formula: 1753 1754 (1846 + 768 << (lc + lp)) * sizeof(uint16) 1755 1756 Where lc and lp stand for, respectively, Literal context bits 1757 and Literal pos bits. 1758 1759 This value is upper-bounded by 14MB in the worst case. Anyway, 1760 for a ~4MB large kernel image, we have lc=3 and lp=0 for a 1761 total amount of (1846 + 768 << (3 + 0)) * 2 = ~41KB... that is 1762 a very small buffer. 1763 1764 Use the lzmainfo tool to determinate the lc and lp values and 1765 then calculate the amount of needed dynamic memory (ensuring 1766 the appropriate CONFIG_SYS_MALLOC_LEN value). 1767 1768 CONFIG_LZO 1769 1770 If this option is set, support for LZO compressed images 1771 is included. 1772 1773- MII/PHY support: 1774 CONFIG_PHY_ADDR 1775 1776 The address of PHY on MII bus. 1777 1778 CONFIG_PHY_CLOCK_FREQ (ppc4xx) 1779 1780 The clock frequency of the MII bus 1781 1782 CONFIG_PHY_GIGE 1783 1784 If this option is set, support for speed/duplex 1785 detection of gigabit PHY is included. 1786 1787 CONFIG_PHY_RESET_DELAY 1788 1789 Some PHY like Intel LXT971A need extra delay after 1790 reset before any MII register access is possible. 1791 For such PHY, set this option to the usec delay 1792 required. (minimum 300usec for LXT971A) 1793 1794 CONFIG_PHY_CMD_DELAY (ppc4xx) 1795 1796 Some PHY like Intel LXT971A need extra delay after 1797 command issued before MII status register can be read 1798 1799- IP address: 1800 CONFIG_IPADDR 1801 1802 Define a default value for the IP address to use for 1803 the default Ethernet interface, in case this is not 1804 determined through e.g. bootp. 1805 (Environment variable "ipaddr") 1806 1807- Server IP address: 1808 CONFIG_SERVERIP 1809 1810 Defines a default value for the IP address of a TFTP 1811 server to contact when using the "tftboot" command. 1812 (Environment variable "serverip") 1813 1814 CONFIG_KEEP_SERVERADDR 1815 1816 Keeps the server's MAC address, in the env 'serveraddr' 1817 for passing to bootargs (like Linux's netconsole option) 1818 1819- Gateway IP address: 1820 CONFIG_GATEWAYIP 1821 1822 Defines a default value for the IP address of the 1823 default router where packets to other networks are 1824 sent to. 1825 (Environment variable "gatewayip") 1826 1827- Subnet mask: 1828 CONFIG_NETMASK 1829 1830 Defines a default value for the subnet mask (or 1831 routing prefix) which is used to determine if an IP 1832 address belongs to the local subnet or needs to be 1833 forwarded through a router. 1834 (Environment variable "netmask") 1835 1836- Multicast TFTP Mode: 1837 CONFIG_MCAST_TFTP 1838 1839 Defines whether you want to support multicast TFTP as per 1840 rfc-2090; for example to work with atftp. Lets lots of targets 1841 tftp down the same boot image concurrently. Note: the Ethernet 1842 driver in use must provide a function: mcast() to join/leave a 1843 multicast group. 1844 1845- BOOTP Recovery Mode: 1846 CONFIG_BOOTP_RANDOM_DELAY 1847 1848 If you have many targets in a network that try to 1849 boot using BOOTP, you may want to avoid that all 1850 systems send out BOOTP requests at precisely the same 1851 moment (which would happen for instance at recovery 1852 from a power failure, when all systems will try to 1853 boot, thus flooding the BOOTP server. Defining 1854 CONFIG_BOOTP_RANDOM_DELAY causes a random delay to be 1855 inserted before sending out BOOTP requests. The 1856 following delays are inserted then: 1857 1858 1st BOOTP request: delay 0 ... 1 sec 1859 2nd BOOTP request: delay 0 ... 2 sec 1860 3rd BOOTP request: delay 0 ... 4 sec 1861 4th and following 1862 BOOTP requests: delay 0 ... 8 sec 1863 1864 CONFIG_BOOTP_ID_CACHE_SIZE 1865 1866 BOOTP packets are uniquely identified using a 32-bit ID. The 1867 server will copy the ID from client requests to responses and 1868 U-Boot will use this to determine if it is the destination of 1869 an incoming response. Some servers will check that addresses 1870 aren't in use before handing them out (usually using an ARP 1871 ping) and therefore take up to a few hundred milliseconds to 1872 respond. Network congestion may also influence the time it 1873 takes for a response to make it back to the client. If that 1874 time is too long, U-Boot will retransmit requests. In order 1875 to allow earlier responses to still be accepted after these 1876 retransmissions, U-Boot's BOOTP client keeps a small cache of 1877 IDs. The CONFIG_BOOTP_ID_CACHE_SIZE controls the size of this 1878 cache. The default is to keep IDs for up to four outstanding 1879 requests. Increasing this will allow U-Boot to accept offers 1880 from a BOOTP client in networks with unusually high latency. 1881 1882- DHCP Advanced Options: 1883 You can fine tune the DHCP functionality by defining 1884 CONFIG_BOOTP_* symbols: 1885 1886 CONFIG_BOOTP_SUBNETMASK 1887 CONFIG_BOOTP_GATEWAY 1888 CONFIG_BOOTP_HOSTNAME 1889 CONFIG_BOOTP_NISDOMAIN 1890 CONFIG_BOOTP_BOOTPATH 1891 CONFIG_BOOTP_BOOTFILESIZE 1892 CONFIG_BOOTP_DNS 1893 CONFIG_BOOTP_DNS2 1894 CONFIG_BOOTP_SEND_HOSTNAME 1895 CONFIG_BOOTP_NTPSERVER 1896 CONFIG_BOOTP_TIMEOFFSET 1897 CONFIG_BOOTP_VENDOREX 1898 CONFIG_BOOTP_MAY_FAIL 1899 1900 CONFIG_BOOTP_SERVERIP - TFTP server will be the serverip 1901 environment variable, not the BOOTP server. 1902 1903 CONFIG_BOOTP_MAY_FAIL - If the DHCP server is not found 1904 after the configured retry count, the call will fail 1905 instead of starting over. This can be used to fail over 1906 to Link-local IP address configuration if the DHCP server 1907 is not available. 1908 1909 CONFIG_BOOTP_DNS2 - If a DHCP client requests the DNS 1910 serverip from a DHCP server, it is possible that more 1911 than one DNS serverip is offered to the client. 1912 If CONFIG_BOOTP_DNS2 is enabled, the secondary DNS 1913 serverip will be stored in the additional environment 1914 variable "dnsip2". The first DNS serverip is always 1915 stored in the variable "dnsip", when CONFIG_BOOTP_DNS 1916 is defined. 1917 1918 CONFIG_BOOTP_SEND_HOSTNAME - Some DHCP servers are capable 1919 to do a dynamic update of a DNS server. To do this, they 1920 need the hostname of the DHCP requester. 1921 If CONFIG_BOOTP_SEND_HOSTNAME is defined, the content 1922 of the "hostname" environment variable is passed as 1923 option 12 to the DHCP server. 1924 1925 CONFIG_BOOTP_DHCP_REQUEST_DELAY 1926 1927 A 32bit value in microseconds for a delay between 1928 receiving a "DHCP Offer" and sending the "DHCP Request". 1929 This fixes a problem with certain DHCP servers that don't 1930 respond 100% of the time to a "DHCP request". E.g. On an 1931 AT91RM9200 processor running at 180MHz, this delay needed 1932 to be *at least* 15,000 usec before a Windows Server 2003 1933 DHCP server would reply 100% of the time. I recommend at 1934 least 50,000 usec to be safe. The alternative is to hope 1935 that one of the retries will be successful but note that 1936 the DHCP timeout and retry process takes a longer than 1937 this delay. 1938 1939 - Link-local IP address negotiation: 1940 Negotiate with other link-local clients on the local network 1941 for an address that doesn't require explicit configuration. 1942 This is especially useful if a DHCP server cannot be guaranteed 1943 to exist in all environments that the device must operate. 1944 1945 See doc/README.link-local for more information. 1946 1947 - CDP Options: 1948 CONFIG_CDP_DEVICE_ID 1949 1950 The device id used in CDP trigger frames. 1951 1952 CONFIG_CDP_DEVICE_ID_PREFIX 1953 1954 A two character string which is prefixed to the MAC address 1955 of the device. 1956 1957 CONFIG_CDP_PORT_ID 1958 1959 A printf format string which contains the ascii name of 1960 the port. Normally is set to "eth%d" which sets 1961 eth0 for the first Ethernet, eth1 for the second etc. 1962 1963 CONFIG_CDP_CAPABILITIES 1964 1965 A 32bit integer which indicates the device capabilities; 1966 0x00000010 for a normal host which does not forwards. 1967 1968 CONFIG_CDP_VERSION 1969 1970 An ascii string containing the version of the software. 1971 1972 CONFIG_CDP_PLATFORM 1973 1974 An ascii string containing the name of the platform. 1975 1976 CONFIG_CDP_TRIGGER 1977 1978 A 32bit integer sent on the trigger. 1979 1980 CONFIG_CDP_POWER_CONSUMPTION 1981 1982 A 16bit integer containing the power consumption of the 1983 device in .1 of milliwatts. 1984 1985 CONFIG_CDP_APPLIANCE_VLAN_TYPE 1986 1987 A byte containing the id of the VLAN. 1988 1989- Status LED: CONFIG_LED_STATUS 1990 1991 Several configurations allow to display the current 1992 status using a LED. For instance, the LED will blink 1993 fast while running U-Boot code, stop blinking as 1994 soon as a reply to a BOOTP request was received, and 1995 start blinking slow once the Linux kernel is running 1996 (supported by a status LED driver in the Linux 1997 kernel). Defining CONFIG_LED_STATUS enables this 1998 feature in U-Boot. 1999 2000 Additional options: 2001 2002 CONFIG_LED_STATUS_GPIO 2003 The status LED can be connected to a GPIO pin. 2004 In such cases, the gpio_led driver can be used as a 2005 status LED backend implementation. Define CONFIG_LED_STATUS_GPIO 2006 to include the gpio_led driver in the U-Boot binary. 2007 2008 CONFIG_GPIO_LED_INVERTED_TABLE 2009 Some GPIO connected LEDs may have inverted polarity in which 2010 case the GPIO high value corresponds to LED off state and 2011 GPIO low value corresponds to LED on state. 2012 In such cases CONFIG_GPIO_LED_INVERTED_TABLE may be defined 2013 with a list of GPIO LEDs that have inverted polarity. 2014 2015- CAN Support: CONFIG_CAN_DRIVER 2016 2017 Defining CONFIG_CAN_DRIVER enables CAN driver support 2018 on those systems that support this (optional) 2019 feature, like the TQM8xxL modules. 2020 2021- I2C Support: CONFIG_SYS_I2C 2022 2023 This enable the NEW i2c subsystem, and will allow you to use 2024 i2c commands at the u-boot command line (as long as you set 2025 CONFIG_CMD_I2C in CONFIG_COMMANDS) and communicate with i2c 2026 based realtime clock chips or other i2c devices. See 2027 common/cmd_i2c.c for a description of the command line 2028 interface. 2029 2030 ported i2c driver to the new framework: 2031 - drivers/i2c/soft_i2c.c: 2032 - activate first bus with CONFIG_SYS_I2C_SOFT define 2033 CONFIG_SYS_I2C_SOFT_SPEED and CONFIG_SYS_I2C_SOFT_SLAVE 2034 for defining speed and slave address 2035 - activate second bus with I2C_SOFT_DECLARATIONS2 define 2036 CONFIG_SYS_I2C_SOFT_SPEED_2 and CONFIG_SYS_I2C_SOFT_SLAVE_2 2037 for defining speed and slave address 2038 - activate third bus with I2C_SOFT_DECLARATIONS3 define 2039 CONFIG_SYS_I2C_SOFT_SPEED_3 and CONFIG_SYS_I2C_SOFT_SLAVE_3 2040 for defining speed and slave address 2041 - activate fourth bus with I2C_SOFT_DECLARATIONS4 define 2042 CONFIG_SYS_I2C_SOFT_SPEED_4 and CONFIG_SYS_I2C_SOFT_SLAVE_4 2043 for defining speed and slave address 2044 2045 - drivers/i2c/fsl_i2c.c: 2046 - activate i2c driver with CONFIG_SYS_I2C_FSL 2047 define CONFIG_SYS_FSL_I2C_OFFSET for setting the register 2048 offset CONFIG_SYS_FSL_I2C_SPEED for the i2c speed and 2049 CONFIG_SYS_FSL_I2C_SLAVE for the slave addr of the first 2050 bus. 2051 - If your board supports a second fsl i2c bus, define 2052 CONFIG_SYS_FSL_I2C2_OFFSET for the register offset 2053 CONFIG_SYS_FSL_I2C2_SPEED for the speed and 2054 CONFIG_SYS_FSL_I2C2_SLAVE for the slave address of the 2055 second bus. 2056 2057 - drivers/i2c/tegra_i2c.c: 2058 - activate this driver with CONFIG_SYS_I2C_TEGRA 2059 - This driver adds 4 i2c buses with a fix speed from 2060 100000 and the slave addr 0! 2061 2062 - drivers/i2c/ppc4xx_i2c.c 2063 - activate this driver with CONFIG_SYS_I2C_PPC4XX 2064 - CONFIG_SYS_I2C_PPC4XX_CH0 activate hardware channel 0 2065 - CONFIG_SYS_I2C_PPC4XX_CH1 activate hardware channel 1 2066 2067 - drivers/i2c/i2c_mxc.c 2068 - activate this driver with CONFIG_SYS_I2C_MXC 2069 - enable bus 1 with CONFIG_SYS_I2C_MXC_I2C1 2070 - enable bus 2 with CONFIG_SYS_I2C_MXC_I2C2 2071 - enable bus 3 with CONFIG_SYS_I2C_MXC_I2C3 2072 - enable bus 4 with CONFIG_SYS_I2C_MXC_I2C4 2073 - define speed for bus 1 with CONFIG_SYS_MXC_I2C1_SPEED 2074 - define slave for bus 1 with CONFIG_SYS_MXC_I2C1_SLAVE 2075 - define speed for bus 2 with CONFIG_SYS_MXC_I2C2_SPEED 2076 - define slave for bus 2 with CONFIG_SYS_MXC_I2C2_SLAVE 2077 - define speed for bus 3 with CONFIG_SYS_MXC_I2C3_SPEED 2078 - define slave for bus 3 with CONFIG_SYS_MXC_I2C3_SLAVE 2079 - define speed for bus 4 with CONFIG_SYS_MXC_I2C4_SPEED 2080 - define slave for bus 4 with CONFIG_SYS_MXC_I2C4_SLAVE 2081 If those defines are not set, default value is 100000 2082 for speed, and 0 for slave. 2083 2084 - drivers/i2c/rcar_i2c.c: 2085 - activate this driver with CONFIG_SYS_I2C_RCAR 2086 - This driver adds 4 i2c buses 2087 2088 - CONFIG_SYS_RCAR_I2C0_BASE for setting the register channel 0 2089 - CONFIG_SYS_RCAR_I2C0_SPEED for for the speed channel 0 2090 - CONFIG_SYS_RCAR_I2C1_BASE for setting the register channel 1 2091 - CONFIG_SYS_RCAR_I2C1_SPEED for for the speed channel 1 2092 - CONFIG_SYS_RCAR_I2C2_BASE for setting the register channel 2 2093 - CONFIG_SYS_RCAR_I2C2_SPEED for for the speed channel 2 2094 - CONFIG_SYS_RCAR_I2C3_BASE for setting the register channel 3 2095 - CONFIG_SYS_RCAR_I2C3_SPEED for for the speed channel 3 2096 - CONFIF_SYS_RCAR_I2C_NUM_CONTROLLERS for number of i2c buses 2097 2098 - drivers/i2c/sh_i2c.c: 2099 - activate this driver with CONFIG_SYS_I2C_SH 2100 - This driver adds from 2 to 5 i2c buses 2101 2102 - CONFIG_SYS_I2C_SH_BASE0 for setting the register channel 0 2103 - CONFIG_SYS_I2C_SH_SPEED0 for for the speed channel 0 2104 - CONFIG_SYS_I2C_SH_BASE1 for setting the register channel 1 2105 - CONFIG_SYS_I2C_SH_SPEED1 for for the speed channel 1 2106 - CONFIG_SYS_I2C_SH_BASE2 for setting the register channel 2 2107 - CONFIG_SYS_I2C_SH_SPEED2 for for the speed channel 2 2108 - CONFIG_SYS_I2C_SH_BASE3 for setting the register channel 3 2109 - CONFIG_SYS_I2C_SH_SPEED3 for for the speed channel 3 2110 - CONFIG_SYS_I2C_SH_BASE4 for setting the register channel 4 2111 - CONFIG_SYS_I2C_SH_SPEED4 for for the speed channel 4 2112 - CONFIG_SYS_I2C_SH_NUM_CONTROLLERS for number of i2c buses 2113 2114 - drivers/i2c/omap24xx_i2c.c 2115 - activate this driver with CONFIG_SYS_I2C_OMAP24XX 2116 - CONFIG_SYS_OMAP24_I2C_SPEED speed channel 0 2117 - CONFIG_SYS_OMAP24_I2C_SLAVE slave addr channel 0 2118 - CONFIG_SYS_OMAP24_I2C_SPEED1 speed channel 1 2119 - CONFIG_SYS_OMAP24_I2C_SLAVE1 slave addr channel 1 2120 - CONFIG_SYS_OMAP24_I2C_SPEED2 speed channel 2 2121 - CONFIG_SYS_OMAP24_I2C_SLAVE2 slave addr channel 2 2122 - CONFIG_SYS_OMAP24_I2C_SPEED3 speed channel 3 2123 - CONFIG_SYS_OMAP24_I2C_SLAVE3 slave addr channel 3 2124 - CONFIG_SYS_OMAP24_I2C_SPEED4 speed channel 4 2125 - CONFIG_SYS_OMAP24_I2C_SLAVE4 slave addr channel 4 2126 2127 - drivers/i2c/zynq_i2c.c 2128 - activate this driver with CONFIG_SYS_I2C_ZYNQ 2129 - set CONFIG_SYS_I2C_ZYNQ_SPEED for speed setting 2130 - set CONFIG_SYS_I2C_ZYNQ_SLAVE for slave addr 2131 2132 - drivers/i2c/s3c24x0_i2c.c: 2133 - activate this driver with CONFIG_SYS_I2C_S3C24X0 2134 - This driver adds i2c buses (11 for Exynos5250, Exynos5420 2135 9 i2c buses for Exynos4 and 1 for S3C24X0 SoCs from Samsung) 2136 with a fix speed from 100000 and the slave addr 0! 2137 2138 - drivers/i2c/ihs_i2c.c 2139 - activate this driver with CONFIG_SYS_I2C_IHS 2140 - CONFIG_SYS_I2C_IHS_CH0 activate hardware channel 0 2141 - CONFIG_SYS_I2C_IHS_SPEED_0 speed channel 0 2142 - CONFIG_SYS_I2C_IHS_SLAVE_0 slave addr channel 0 2143 - CONFIG_SYS_I2C_IHS_CH1 activate hardware channel 1 2144 - CONFIG_SYS_I2C_IHS_SPEED_1 speed channel 1 2145 - CONFIG_SYS_I2C_IHS_SLAVE_1 slave addr channel 1 2146 - CONFIG_SYS_I2C_IHS_CH2 activate hardware channel 2 2147 - CONFIG_SYS_I2C_IHS_SPEED_2 speed channel 2 2148 - CONFIG_SYS_I2C_IHS_SLAVE_2 slave addr channel 2 2149 - CONFIG_SYS_I2C_IHS_CH3 activate hardware channel 3 2150 - CONFIG_SYS_I2C_IHS_SPEED_3 speed channel 3 2151 - CONFIG_SYS_I2C_IHS_SLAVE_3 slave addr channel 3 2152 - activate dual channel with CONFIG_SYS_I2C_IHS_DUAL 2153 - CONFIG_SYS_I2C_IHS_SPEED_0_1 speed channel 0_1 2154 - CONFIG_SYS_I2C_IHS_SLAVE_0_1 slave addr channel 0_1 2155 - CONFIG_SYS_I2C_IHS_SPEED_1_1 speed channel 1_1 2156 - CONFIG_SYS_I2C_IHS_SLAVE_1_1 slave addr channel 1_1 2157 - CONFIG_SYS_I2C_IHS_SPEED_2_1 speed channel 2_1 2158 - CONFIG_SYS_I2C_IHS_SLAVE_2_1 slave addr channel 2_1 2159 - CONFIG_SYS_I2C_IHS_SPEED_3_1 speed channel 3_1 2160 - CONFIG_SYS_I2C_IHS_SLAVE_3_1 slave addr channel 3_1 2161 2162 additional defines: 2163 2164 CONFIG_SYS_NUM_I2C_BUSES 2165 Hold the number of i2c buses you want to use. 2166 2167 CONFIG_SYS_I2C_DIRECT_BUS 2168 define this, if you don't use i2c muxes on your hardware. 2169 if CONFIG_SYS_I2C_MAX_HOPS is not defined or == 0 you can 2170 omit this define. 2171 2172 CONFIG_SYS_I2C_MAX_HOPS 2173 define how many muxes are maximal consecutively connected 2174 on one i2c bus. If you not use i2c muxes, omit this 2175 define. 2176 2177 CONFIG_SYS_I2C_BUSES 2178 hold a list of buses you want to use, only used if 2179 CONFIG_SYS_I2C_DIRECT_BUS is not defined, for example 2180 a board with CONFIG_SYS_I2C_MAX_HOPS = 1 and 2181 CONFIG_SYS_NUM_I2C_BUSES = 9: 2182 2183 CONFIG_SYS_I2C_BUSES {{0, {I2C_NULL_HOP}}, \ 2184 {0, {{I2C_MUX_PCA9547, 0x70, 1}}}, \ 2185 {0, {{I2C_MUX_PCA9547, 0x70, 2}}}, \ 2186 {0, {{I2C_MUX_PCA9547, 0x70, 3}}}, \ 2187 {0, {{I2C_MUX_PCA9547, 0x70, 4}}}, \ 2188 {0, {{I2C_MUX_PCA9547, 0x70, 5}}}, \ 2189 {1, {I2C_NULL_HOP}}, \ 2190 {1, {{I2C_MUX_PCA9544, 0x72, 1}}}, \ 2191 {1, {{I2C_MUX_PCA9544, 0x72, 2}}}, \ 2192 } 2193 2194 which defines 2195 bus 0 on adapter 0 without a mux 2196 bus 1 on adapter 0 with a PCA9547 on address 0x70 port 1 2197 bus 2 on adapter 0 with a PCA9547 on address 0x70 port 2 2198 bus 3 on adapter 0 with a PCA9547 on address 0x70 port 3 2199 bus 4 on adapter 0 with a PCA9547 on address 0x70 port 4 2200 bus 5 on adapter 0 with a PCA9547 on address 0x70 port 5 2201 bus 6 on adapter 1 without a mux 2202 bus 7 on adapter 1 with a PCA9544 on address 0x72 port 1 2203 bus 8 on adapter 1 with a PCA9544 on address 0x72 port 2 2204 2205 If you do not have i2c muxes on your board, omit this define. 2206 2207----under removal: 2208 2209- Legacy I2C Support: CONFIG_SOFT_I2C 2210 2211 NOTE: It is intended to move drivers to CONFIG_SYS_I2C which 2212 provides the following compelling advantages: 2213 2214 - more than one i2c adapter is usable 2215 - approved multibus support 2216 - better i2c mux support 2217 2218 ** CONFIG_SOFT_I2C is now being removed ** 2219 2220 With CONFIG_SOFT_I2C you will need to define 2221 CONFIG_SYS_I2C_SPEED to be the frequency (in Hz) at which you 2222 wish your i2c bus to run and CONFIG_SYS_I2C_SLAVE to be the 2223 address of this node (ie the CPU's i2c node address). 2224 2225 Now, the u-boot i2c code for the mpc8xx 2226 (arch/powerpc/cpu/mpc8xx/i2c.c) sets the CPU up as a master node 2227 and so its address should therefore be cleared to 0 (See, 2228 eg, MPC823e User's Manual p.16-473). So, set 2229 CONFIG_SYS_I2C_SLAVE to 0. 2230 2231 When a board is reset during an i2c bus transfer 2232 chips might think that the current transfer is still 2233 in progress. Reset the slave devices by sending start 2234 commands until the slave device responds. 2235 2236 That's all that's required for CONFIG_HARD_I2C. 2237 2238 If you use the software i2c interface (CONFIG_SYS_I2C_SOFT) 2239 then the following macros need to be defined (examples are 2240 from include/configs/lwmon.h): 2241 2242 I2C_INIT 2243 2244 (Optional). Any commands necessary to enable the I2C 2245 controller or configure ports. 2246 2247 eg: #define I2C_INIT (immr->im_cpm.cp_pbdir |= PB_SCL) 2248 2249 I2C_PORT 2250 2251 (Only for MPC8260 CPU). The I/O port to use (the code 2252 assumes both bits are on the same port). Valid values 2253 are 0..3 for ports A..D. 2254 2255 I2C_ACTIVE 2256 2257 The code necessary to make the I2C data line active 2258 (driven). If the data line is open collector, this 2259 define can be null. 2260 2261 eg: #define I2C_ACTIVE (immr->im_cpm.cp_pbdir |= PB_SDA) 2262 2263 I2C_TRISTATE 2264 2265 The code necessary to make the I2C data line tri-stated 2266 (inactive). If the data line is open collector, this 2267 define can be null. 2268 2269 eg: #define I2C_TRISTATE (immr->im_cpm.cp_pbdir &= ~PB_SDA) 2270 2271 I2C_READ 2272 2273 Code that returns true if the I2C data line is high, 2274 false if it is low. 2275 2276 eg: #define I2C_READ ((immr->im_cpm.cp_pbdat & PB_SDA) != 0) 2277 2278 I2C_SDA(bit) 2279 2280 If <bit> is true, sets the I2C data line high. If it 2281 is false, it clears it (low). 2282 2283 eg: #define I2C_SDA(bit) \ 2284 if(bit) immr->im_cpm.cp_pbdat |= PB_SDA; \ 2285 else immr->im_cpm.cp_pbdat &= ~PB_SDA 2286 2287 I2C_SCL(bit) 2288 2289 If <bit> is true, sets the I2C clock line high. If it 2290 is false, it clears it (low). 2291 2292 eg: #define I2C_SCL(bit) \ 2293 if(bit) immr->im_cpm.cp_pbdat |= PB_SCL; \ 2294 else immr->im_cpm.cp_pbdat &= ~PB_SCL 2295 2296 I2C_DELAY 2297 2298 This delay is invoked four times per clock cycle so this 2299 controls the rate of data transfer. The data rate thus 2300 is 1 / (I2C_DELAY * 4). Often defined to be something 2301 like: 2302 2303 #define I2C_DELAY udelay(2) 2304 2305 CONFIG_SOFT_I2C_GPIO_SCL / CONFIG_SOFT_I2C_GPIO_SDA 2306 2307 If your arch supports the generic GPIO framework (asm/gpio.h), 2308 then you may alternatively define the two GPIOs that are to be 2309 used as SCL / SDA. Any of the previous I2C_xxx macros will 2310 have GPIO-based defaults assigned to them as appropriate. 2311 2312 You should define these to the GPIO value as given directly to 2313 the generic GPIO functions. 2314 2315 CONFIG_SYS_I2C_INIT_BOARD 2316 2317 When a board is reset during an i2c bus transfer 2318 chips might think that the current transfer is still 2319 in progress. On some boards it is possible to access 2320 the i2c SCLK line directly, either by using the 2321 processor pin as a GPIO or by having a second pin 2322 connected to the bus. If this option is defined a 2323 custom i2c_init_board() routine in boards/xxx/board.c 2324 is run early in the boot sequence. 2325 2326 CONFIG_SYS_I2C_BOARD_LATE_INIT 2327 2328 An alternative to CONFIG_SYS_I2C_INIT_BOARD. If this option is 2329 defined a custom i2c_board_late_init() routine in 2330 boards/xxx/board.c is run AFTER the operations in i2c_init() 2331 is completed. This callpoint can be used to unreset i2c bus 2332 using CPU i2c controller register accesses for CPUs whose i2c 2333 controller provide such a method. It is called at the end of 2334 i2c_init() to allow i2c_init operations to setup the i2c bus 2335 controller on the CPU (e.g. setting bus speed & slave address). 2336 2337 CONFIG_I2CFAST (PPC405GP|PPC405EP only) 2338 2339 This option enables configuration of bi_iic_fast[] flags 2340 in u-boot bd_info structure based on u-boot environment 2341 variable "i2cfast". (see also i2cfast) 2342 2343 CONFIG_I2C_MULTI_BUS 2344 2345 This option allows the use of multiple I2C buses, each of which 2346 must have a controller. At any point in time, only one bus is 2347 active. To switch to a different bus, use the 'i2c dev' command. 2348 Note that bus numbering is zero-based. 2349 2350 CONFIG_SYS_I2C_NOPROBES 2351 2352 This option specifies a list of I2C devices that will be skipped 2353 when the 'i2c probe' command is issued. If CONFIG_I2C_MULTI_BUS 2354 is set, specify a list of bus-device pairs. Otherwise, specify 2355 a 1D array of device addresses 2356 2357 e.g. 2358 #undef CONFIG_I2C_MULTI_BUS 2359 #define CONFIG_SYS_I2C_NOPROBES {0x50,0x68} 2360 2361 will skip addresses 0x50 and 0x68 on a board with one I2C bus 2362 2363 #define CONFIG_I2C_MULTI_BUS 2364 #define CONFIG_SYS_I2C_NOPROBES {{0,0x50},{0,0x68},{1,0x54}} 2365 2366 will skip addresses 0x50 and 0x68 on bus 0 and address 0x54 on bus 1 2367 2368 CONFIG_SYS_SPD_BUS_NUM 2369 2370 If defined, then this indicates the I2C bus number for DDR SPD. 2371 If not defined, then U-Boot assumes that SPD is on I2C bus 0. 2372 2373 CONFIG_SYS_RTC_BUS_NUM 2374 2375 If defined, then this indicates the I2C bus number for the RTC. 2376 If not defined, then U-Boot assumes that RTC is on I2C bus 0. 2377 2378 CONFIG_SYS_DTT_BUS_NUM 2379 2380 If defined, then this indicates the I2C bus number for the DTT. 2381 If not defined, then U-Boot assumes that DTT is on I2C bus 0. 2382 2383 CONFIG_SYS_I2C_DTT_ADDR: 2384 2385 If defined, specifies the I2C address of the DTT device. 2386 If not defined, then U-Boot uses predefined value for 2387 specified DTT device. 2388 2389 CONFIG_SOFT_I2C_READ_REPEATED_START 2390 2391 defining this will force the i2c_read() function in 2392 the soft_i2c driver to perform an I2C repeated start 2393 between writing the address pointer and reading the 2394 data. If this define is omitted the default behaviour 2395 of doing a stop-start sequence will be used. Most I2C 2396 devices can use either method, but some require one or 2397 the other. 2398 2399- SPI Support: CONFIG_SPI 2400 2401 Enables SPI driver (so far only tested with 2402 SPI EEPROM, also an instance works with Crystal A/D and 2403 D/As on the SACSng board) 2404 2405 CONFIG_SH_SPI 2406 2407 Enables the driver for SPI controller on SuperH. Currently 2408 only SH7757 is supported. 2409 2410 CONFIG_SOFT_SPI 2411 2412 Enables a software (bit-bang) SPI driver rather than 2413 using hardware support. This is a general purpose 2414 driver that only requires three general I/O port pins 2415 (two outputs, one input) to function. If this is 2416 defined, the board configuration must define several 2417 SPI configuration items (port pins to use, etc). For 2418 an example, see include/configs/sacsng.h. 2419 2420 CONFIG_HARD_SPI 2421 2422 Enables a hardware SPI driver for general-purpose reads 2423 and writes. As with CONFIG_SOFT_SPI, the board configuration 2424 must define a list of chip-select function pointers. 2425 Currently supported on some MPC8xxx processors. For an 2426 example, see include/configs/mpc8349emds.h. 2427 2428 CONFIG_MXC_SPI 2429 2430 Enables the driver for the SPI controllers on i.MX and MXC 2431 SoCs. Currently i.MX31/35/51 are supported. 2432 2433 CONFIG_SYS_SPI_MXC_WAIT 2434 Timeout for waiting until spi transfer completed. 2435 default: (CONFIG_SYS_HZ/100) /* 10 ms */ 2436 2437- FPGA Support: CONFIG_FPGA 2438 2439 Enables FPGA subsystem. 2440 2441 CONFIG_FPGA_<vendor> 2442 2443 Enables support for specific chip vendors. 2444 (ALTERA, XILINX) 2445 2446 CONFIG_FPGA_<family> 2447 2448 Enables support for FPGA family. 2449 (SPARTAN2, SPARTAN3, VIRTEX2, CYCLONE2, ACEX1K, ACEX) 2450 2451 CONFIG_FPGA_COUNT 2452 2453 Specify the number of FPGA devices to support. 2454 2455 CONFIG_CMD_FPGA_LOADMK 2456 2457 Enable support for fpga loadmk command 2458 2459 CONFIG_CMD_FPGA_LOADP 2460 2461 Enable support for fpga loadp command - load partial bitstream 2462 2463 CONFIG_CMD_FPGA_LOADBP 2464 2465 Enable support for fpga loadbp command - load partial bitstream 2466 (Xilinx only) 2467 2468 CONFIG_SYS_FPGA_PROG_FEEDBACK 2469 2470 Enable printing of hash marks during FPGA configuration. 2471 2472 CONFIG_SYS_FPGA_CHECK_BUSY 2473 2474 Enable checks on FPGA configuration interface busy 2475 status by the configuration function. This option 2476 will require a board or device specific function to 2477 be written. 2478 2479 CONFIG_FPGA_DELAY 2480 2481 If defined, a function that provides delays in the FPGA 2482 configuration driver. 2483 2484 CONFIG_SYS_FPGA_CHECK_CTRLC 2485 Allow Control-C to interrupt FPGA configuration 2486 2487 CONFIG_SYS_FPGA_CHECK_ERROR 2488 2489 Check for configuration errors during FPGA bitfile 2490 loading. For example, abort during Virtex II 2491 configuration if the INIT_B line goes low (which 2492 indicated a CRC error). 2493 2494 CONFIG_SYS_FPGA_WAIT_INIT 2495 2496 Maximum time to wait for the INIT_B line to de-assert 2497 after PROB_B has been de-asserted during a Virtex II 2498 FPGA configuration sequence. The default time is 500 2499 ms. 2500 2501 CONFIG_SYS_FPGA_WAIT_BUSY 2502 2503 Maximum time to wait for BUSY to de-assert during 2504 Virtex II FPGA configuration. The default is 5 ms. 2505 2506 CONFIG_SYS_FPGA_WAIT_CONFIG 2507 2508 Time to wait after FPGA configuration. The default is 2509 200 ms. 2510 2511- Configuration Management: 2512 CONFIG_BUILD_TARGET 2513 2514 Some SoCs need special image types (e.g. U-Boot binary 2515 with a special header) as build targets. By defining 2516 CONFIG_BUILD_TARGET in the SoC / board header, this 2517 special image will be automatically built upon calling 2518 make / buildman. 2519 2520 CONFIG_IDENT_STRING 2521 2522 If defined, this string will be added to the U-Boot 2523 version information (U_BOOT_VERSION) 2524 2525- Vendor Parameter Protection: 2526 2527 U-Boot considers the values of the environment 2528 variables "serial#" (Board Serial Number) and 2529 "ethaddr" (Ethernet Address) to be parameters that 2530 are set once by the board vendor / manufacturer, and 2531 protects these variables from casual modification by 2532 the user. Once set, these variables are read-only, 2533 and write or delete attempts are rejected. You can 2534 change this behaviour: 2535 2536 If CONFIG_ENV_OVERWRITE is #defined in your config 2537 file, the write protection for vendor parameters is 2538 completely disabled. Anybody can change or delete 2539 these parameters. 2540 2541 Alternatively, if you define _both_ an ethaddr in the 2542 default env _and_ CONFIG_OVERWRITE_ETHADDR_ONCE, a default 2543 Ethernet address is installed in the environment, 2544 which can be changed exactly ONCE by the user. [The 2545 serial# is unaffected by this, i. e. it remains 2546 read-only.] 2547 2548 The same can be accomplished in a more flexible way 2549 for any variable by configuring the type of access 2550 to allow for those variables in the ".flags" variable 2551 or define CONFIG_ENV_FLAGS_LIST_STATIC. 2552 2553- Protected RAM: 2554 CONFIG_PRAM 2555 2556 Define this variable to enable the reservation of 2557 "protected RAM", i. e. RAM which is not overwritten 2558 by U-Boot. Define CONFIG_PRAM to hold the number of 2559 kB you want to reserve for pRAM. You can overwrite 2560 this default value by defining an environment 2561 variable "pram" to the number of kB you want to 2562 reserve. Note that the board info structure will 2563 still show the full amount of RAM. If pRAM is 2564 reserved, a new environment variable "mem" will 2565 automatically be defined to hold the amount of 2566 remaining RAM in a form that can be passed as boot 2567 argument to Linux, for instance like that: 2568 2569 setenv bootargs ... mem=\${mem} 2570 saveenv 2571 2572 This way you can tell Linux not to use this memory, 2573 either, which results in a memory region that will 2574 not be affected by reboots. 2575 2576 *WARNING* If your board configuration uses automatic 2577 detection of the RAM size, you must make sure that 2578 this memory test is non-destructive. So far, the 2579 following board configurations are known to be 2580 "pRAM-clean": 2581 2582 IVMS8, IVML24, SPD8xx, TQM8xxL, 2583 HERMES, IP860, RPXlite, LWMON, 2584 FLAGADM, TQM8260 2585 2586- Access to physical memory region (> 4GB) 2587 Some basic support is provided for operations on memory not 2588 normally accessible to U-Boot - e.g. some architectures 2589 support access to more than 4GB of memory on 32-bit 2590 machines using physical address extension or similar. 2591 Define CONFIG_PHYSMEM to access this basic support, which 2592 currently only supports clearing the memory. 2593 2594- Error Recovery: 2595 CONFIG_PANIC_HANG 2596 2597 Define this variable to stop the system in case of a 2598 fatal error, so that you have to reset it manually. 2599 This is probably NOT a good idea for an embedded 2600 system where you want the system to reboot 2601 automatically as fast as possible, but it may be 2602 useful during development since you can try to debug 2603 the conditions that lead to the situation. 2604 2605 CONFIG_NET_RETRY_COUNT 2606 2607 This variable defines the number of retries for 2608 network operations like ARP, RARP, TFTP, or BOOTP 2609 before giving up the operation. If not defined, a 2610 default value of 5 is used. 2611 2612 CONFIG_ARP_TIMEOUT 2613 2614 Timeout waiting for an ARP reply in milliseconds. 2615 2616 CONFIG_NFS_TIMEOUT 2617 2618 Timeout in milliseconds used in NFS protocol. 2619 If you encounter "ERROR: Cannot umount" in nfs command, 2620 try longer timeout such as 2621 #define CONFIG_NFS_TIMEOUT 10000UL 2622 2623- Command Interpreter: 2624 CONFIG_AUTO_COMPLETE 2625 2626 Enable auto completion of commands using TAB. 2627 2628 CONFIG_SYS_PROMPT_HUSH_PS2 2629 2630 This defines the secondary prompt string, which is 2631 printed when the command interpreter needs more input 2632 to complete a command. Usually "> ". 2633 2634 Note: 2635 2636 In the current implementation, the local variables 2637 space and global environment variables space are 2638 separated. Local variables are those you define by 2639 simply typing `name=value'. To access a local 2640 variable later on, you have write `$name' or 2641 `${name}'; to execute the contents of a variable 2642 directly type `$name' at the command prompt. 2643 2644 Global environment variables are those you use 2645 setenv/printenv to work with. To run a command stored 2646 in such a variable, you need to use the run command, 2647 and you must not use the '$' sign to access them. 2648 2649 To store commands and special characters in a 2650 variable, please use double quotation marks 2651 surrounding the whole text of the variable, instead 2652 of the backslashes before semicolons and special 2653 symbols. 2654 2655- Command Line Editing and History: 2656 CONFIG_CMDLINE_EDITING 2657 2658 Enable editing and History functions for interactive 2659 command line input operations 2660 2661- Command Line PS1/PS2 support: 2662 CONFIG_CMDLINE_PS_SUPPORT 2663 2664 Enable support for changing the command prompt string 2665 at run-time. Only static string is supported so far. 2666 The string is obtained from environment variables PS1 2667 and PS2. 2668 2669- Default Environment: 2670 CONFIG_EXTRA_ENV_SETTINGS 2671 2672 Define this to contain any number of null terminated 2673 strings (variable = value pairs) that will be part of 2674 the default environment compiled into the boot image. 2675 2676 For example, place something like this in your 2677 board's config file: 2678 2679 #define CONFIG_EXTRA_ENV_SETTINGS \ 2680 "myvar1=value1\0" \ 2681 "myvar2=value2\0" 2682 2683 Warning: This method is based on knowledge about the 2684 internal format how the environment is stored by the 2685 U-Boot code. This is NOT an official, exported 2686 interface! Although it is unlikely that this format 2687 will change soon, there is no guarantee either. 2688 You better know what you are doing here. 2689 2690 Note: overly (ab)use of the default environment is 2691 discouraged. Make sure to check other ways to preset 2692 the environment like the "source" command or the 2693 boot command first. 2694 2695 CONFIG_ENV_VARS_UBOOT_CONFIG 2696 2697 Define this in order to add variables describing the 2698 U-Boot build configuration to the default environment. 2699 These will be named arch, cpu, board, vendor, and soc. 2700 2701 Enabling this option will cause the following to be defined: 2702 2703 - CONFIG_SYS_ARCH 2704 - CONFIG_SYS_CPU 2705 - CONFIG_SYS_BOARD 2706 - CONFIG_SYS_VENDOR 2707 - CONFIG_SYS_SOC 2708 2709 CONFIG_ENV_VARS_UBOOT_RUNTIME_CONFIG 2710 2711 Define this in order to add variables describing certain 2712 run-time determined information about the hardware to the 2713 environment. These will be named board_name, board_rev. 2714 2715 CONFIG_DELAY_ENVIRONMENT 2716 2717 Normally the environment is loaded when the board is 2718 initialised so that it is available to U-Boot. This inhibits 2719 that so that the environment is not available until 2720 explicitly loaded later by U-Boot code. With CONFIG_OF_CONTROL 2721 this is instead controlled by the value of 2722 /config/load-environment. 2723 2724- DataFlash Support: 2725 CONFIG_HAS_DATAFLASH 2726 2727 Defining this option enables DataFlash features and 2728 allows to read/write in Dataflash via the standard 2729 commands cp, md... 2730 2731- Serial Flash support 2732 CONFIG_CMD_SF 2733 2734 Defining this option enables SPI flash commands 2735 'sf probe/read/write/erase/update'. 2736 2737 Usage requires an initial 'probe' to define the serial 2738 flash parameters, followed by read/write/erase/update 2739 commands. 2740 2741 The following defaults may be provided by the platform 2742 to handle the common case when only a single serial 2743 flash is present on the system. 2744 2745 CONFIG_SF_DEFAULT_BUS Bus identifier 2746 CONFIG_SF_DEFAULT_CS Chip-select 2747 CONFIG_SF_DEFAULT_MODE (see include/spi.h) 2748 CONFIG_SF_DEFAULT_SPEED in Hz 2749 2750 CONFIG_CMD_SF_TEST 2751 2752 Define this option to include a destructive SPI flash 2753 test ('sf test'). 2754 2755 CONFIG_SF_DUAL_FLASH Dual flash memories 2756 2757 Define this option to use dual flash support where two flash 2758 memories can be connected with a given cs line. 2759 Currently Xilinx Zynq qspi supports these type of connections. 2760 2761- SystemACE Support: 2762 CONFIG_SYSTEMACE 2763 2764 Adding this option adds support for Xilinx SystemACE 2765 chips attached via some sort of local bus. The address 2766 of the chip must also be defined in the 2767 CONFIG_SYS_SYSTEMACE_BASE macro. For example: 2768 2769 #define CONFIG_SYSTEMACE 2770 #define CONFIG_SYS_SYSTEMACE_BASE 0xf0000000 2771 2772 When SystemACE support is added, the "ace" device type 2773 becomes available to the fat commands, i.e. fatls. 2774 2775- TFTP Fixed UDP Port: 2776 CONFIG_TFTP_PORT 2777 2778 If this is defined, the environment variable tftpsrcp 2779 is used to supply the TFTP UDP source port value. 2780 If tftpsrcp isn't defined, the normal pseudo-random port 2781 number generator is used. 2782 2783 Also, the environment variable tftpdstp is used to supply 2784 the TFTP UDP destination port value. If tftpdstp isn't 2785 defined, the normal port 69 is used. 2786 2787 The purpose for tftpsrcp is to allow a TFTP server to 2788 blindly start the TFTP transfer using the pre-configured 2789 target IP address and UDP port. This has the effect of 2790 "punching through" the (Windows XP) firewall, allowing 2791 the remainder of the TFTP transfer to proceed normally. 2792 A better solution is to properly configure the firewall, 2793 but sometimes that is not allowed. 2794 2795- Hashing support: 2796 CONFIG_CMD_HASH 2797 2798 This enables a generic 'hash' command which can produce 2799 hashes / digests from a few algorithms (e.g. SHA1, SHA256). 2800 2801 CONFIG_HASH_VERIFY 2802 2803 Enable the hash verify command (hash -v). This adds to code 2804 size a little. 2805 2806 CONFIG_SHA1 - This option enables support of hashing using SHA1 2807 algorithm. The hash is calculated in software. 2808 CONFIG_SHA256 - This option enables support of hashing using 2809 SHA256 algorithm. The hash is calculated in software. 2810 CONFIG_SHA_HW_ACCEL - This option enables hardware acceleration 2811 for SHA1/SHA256 hashing. 2812 This affects the 'hash' command and also the 2813 hash_lookup_algo() function. 2814 CONFIG_SHA_PROG_HW_ACCEL - This option enables 2815 hardware-acceleration for SHA1/SHA256 progressive hashing. 2816 Data can be streamed in a block at a time and the hashing 2817 is performed in hardware. 2818 2819 Note: There is also a sha1sum command, which should perhaps 2820 be deprecated in favour of 'hash sha1'. 2821 2822- Freescale i.MX specific commands: 2823 CONFIG_CMD_HDMIDETECT 2824 This enables 'hdmidet' command which returns true if an 2825 HDMI monitor is detected. This command is i.MX 6 specific. 2826 2827- bootcount support: 2828 CONFIG_BOOTCOUNT_LIMIT 2829 2830 This enables the bootcounter support, see: 2831 http://www.denx.de/wiki/DULG/UBootBootCountLimit 2832 2833 CONFIG_AT91SAM9XE 2834 enable special bootcounter support on at91sam9xe based boards. 2835 CONFIG_SOC_DA8XX 2836 enable special bootcounter support on da850 based boards. 2837 CONFIG_BOOTCOUNT_RAM 2838 enable support for the bootcounter in RAM 2839 CONFIG_BOOTCOUNT_I2C 2840 enable support for the bootcounter on an i2c (like RTC) device. 2841 CONFIG_SYS_I2C_RTC_ADDR = i2c chip address 2842 CONFIG_SYS_BOOTCOUNT_ADDR = i2c addr which is used for 2843 the bootcounter. 2844 CONFIG_BOOTCOUNT_ALEN = address len 2845 2846- Show boot progress: 2847 CONFIG_SHOW_BOOT_PROGRESS 2848 2849 Defining this option allows to add some board- 2850 specific code (calling a user-provided function 2851 "show_boot_progress(int)") that enables you to show 2852 the system's boot progress on some display (for 2853 example, some LED's) on your board. At the moment, 2854 the following checkpoints are implemented: 2855 2856 2857Legacy uImage format: 2858 2859 Arg Where When 2860 1 common/cmd_bootm.c before attempting to boot an image 2861 -1 common/cmd_bootm.c Image header has bad magic number 2862 2 common/cmd_bootm.c Image header has correct magic number 2863 -2 common/cmd_bootm.c Image header has bad checksum 2864 3 common/cmd_bootm.c Image header has correct checksum 2865 -3 common/cmd_bootm.c Image data has bad checksum 2866 4 common/cmd_bootm.c Image data has correct checksum 2867 -4 common/cmd_bootm.c Image is for unsupported architecture 2868 5 common/cmd_bootm.c Architecture check OK 2869 -5 common/cmd_bootm.c Wrong Image Type (not kernel, multi) 2870 6 common/cmd_bootm.c Image Type check OK 2871 -6 common/cmd_bootm.c gunzip uncompression error 2872 -7 common/cmd_bootm.c Unimplemented compression type 2873 7 common/cmd_bootm.c Uncompression OK 2874 8 common/cmd_bootm.c No uncompress/copy overwrite error 2875 -9 common/cmd_bootm.c Unsupported OS (not Linux, BSD, VxWorks, QNX) 2876 2877 9 common/image.c Start initial ramdisk verification 2878 -10 common/image.c Ramdisk header has bad magic number 2879 -11 common/image.c Ramdisk header has bad checksum 2880 10 common/image.c Ramdisk header is OK 2881 -12 common/image.c Ramdisk data has bad checksum 2882 11 common/image.c Ramdisk data has correct checksum 2883 12 common/image.c Ramdisk verification complete, start loading 2884 -13 common/image.c Wrong Image Type (not PPC Linux ramdisk) 2885 13 common/image.c Start multifile image verification 2886 14 common/image.c No initial ramdisk, no multifile, continue. 2887 2888 15 arch/<arch>/lib/bootm.c All preparation done, transferring control to OS 2889 2890 -30 arch/powerpc/lib/board.c Fatal error, hang the system 2891 -31 post/post.c POST test failed, detected by post_output_backlog() 2892 -32 post/post.c POST test failed, detected by post_run_single() 2893 2894 34 common/cmd_doc.c before loading a Image from a DOC device 2895 -35 common/cmd_doc.c Bad usage of "doc" command 2896 35 common/cmd_doc.c correct usage of "doc" command 2897 -36 common/cmd_doc.c No boot device 2898 36 common/cmd_doc.c correct boot device 2899 -37 common/cmd_doc.c Unknown Chip ID on boot device 2900 37 common/cmd_doc.c correct chip ID found, device available 2901 -38 common/cmd_doc.c Read Error on boot device 2902 38 common/cmd_doc.c reading Image header from DOC device OK 2903 -39 common/cmd_doc.c Image header has bad magic number 2904 39 common/cmd_doc.c Image header has correct magic number 2905 -40 common/cmd_doc.c Error reading Image from DOC device 2906 40 common/cmd_doc.c Image header has correct magic number 2907 41 common/cmd_ide.c before loading a Image from a IDE device 2908 -42 common/cmd_ide.c Bad usage of "ide" command 2909 42 common/cmd_ide.c correct usage of "ide" command 2910 -43 common/cmd_ide.c No boot device 2911 43 common/cmd_ide.c boot device found 2912 -44 common/cmd_ide.c Device not available 2913 44 common/cmd_ide.c Device available 2914 -45 common/cmd_ide.c wrong partition selected 2915 45 common/cmd_ide.c partition selected 2916 -46 common/cmd_ide.c Unknown partition table 2917 46 common/cmd_ide.c valid partition table found 2918 -47 common/cmd_ide.c Invalid partition type 2919 47 common/cmd_ide.c correct partition type 2920 -48 common/cmd_ide.c Error reading Image Header on boot device 2921 48 common/cmd_ide.c reading Image Header from IDE device OK 2922 -49 common/cmd_ide.c Image header has bad magic number 2923 49 common/cmd_ide.c Image header has correct magic number 2924 -50 common/cmd_ide.c Image header has bad checksum 2925 50 common/cmd_ide.c Image header has correct checksum 2926 -51 common/cmd_ide.c Error reading Image from IDE device 2927 51 common/cmd_ide.c reading Image from IDE device OK 2928 52 common/cmd_nand.c before loading a Image from a NAND device 2929 -53 common/cmd_nand.c Bad usage of "nand" command 2930 53 common/cmd_nand.c correct usage of "nand" command 2931 -54 common/cmd_nand.c No boot device 2932 54 common/cmd_nand.c boot device found 2933 -55 common/cmd_nand.c Unknown Chip ID on boot device 2934 55 common/cmd_nand.c correct chip ID found, device available 2935 -56 common/cmd_nand.c Error reading Image Header on boot device 2936 56 common/cmd_nand.c reading Image Header from NAND device OK 2937 -57 common/cmd_nand.c Image header has bad magic number 2938 57 common/cmd_nand.c Image header has correct magic number 2939 -58 common/cmd_nand.c Error reading Image from NAND device 2940 58 common/cmd_nand.c reading Image from NAND device OK 2941 2942 -60 common/env_common.c Environment has a bad CRC, using default 2943 2944 64 net/eth.c starting with Ethernet configuration. 2945 -64 net/eth.c no Ethernet found. 2946 65 net/eth.c Ethernet found. 2947 2948 -80 common/cmd_net.c usage wrong 2949 80 common/cmd_net.c before calling net_loop() 2950 -81 common/cmd_net.c some error in net_loop() occurred 2951 81 common/cmd_net.c net_loop() back without error 2952 -82 common/cmd_net.c size == 0 (File with size 0 loaded) 2953 82 common/cmd_net.c trying automatic boot 2954 83 common/cmd_net.c running "source" command 2955 -83 common/cmd_net.c some error in automatic boot or "source" command 2956 84 common/cmd_net.c end without errors 2957 2958FIT uImage format: 2959 2960 Arg Where When 2961 100 common/cmd_bootm.c Kernel FIT Image has correct format 2962 -100 common/cmd_bootm.c Kernel FIT Image has incorrect format 2963 101 common/cmd_bootm.c No Kernel subimage unit name, using configuration 2964 -101 common/cmd_bootm.c Can't get configuration for kernel subimage 2965 102 common/cmd_bootm.c Kernel unit name specified 2966 -103 common/cmd_bootm.c Can't get kernel subimage node offset 2967 103 common/cmd_bootm.c Found configuration node 2968 104 common/cmd_bootm.c Got kernel subimage node offset 2969 -104 common/cmd_bootm.c Kernel subimage hash verification failed 2970 105 common/cmd_bootm.c Kernel subimage hash verification OK 2971 -105 common/cmd_bootm.c Kernel subimage is for unsupported architecture 2972 106 common/cmd_bootm.c Architecture check OK 2973 -106 common/cmd_bootm.c Kernel subimage has wrong type 2974 107 common/cmd_bootm.c Kernel subimage type OK 2975 -107 common/cmd_bootm.c Can't get kernel subimage data/size 2976 108 common/cmd_bootm.c Got kernel subimage data/size 2977 -108 common/cmd_bootm.c Wrong image type (not legacy, FIT) 2978 -109 common/cmd_bootm.c Can't get kernel subimage type 2979 -110 common/cmd_bootm.c Can't get kernel subimage comp 2980 -111 common/cmd_bootm.c Can't get kernel subimage os 2981 -112 common/cmd_bootm.c Can't get kernel subimage load address 2982 -113 common/cmd_bootm.c Image uncompress/copy overwrite error 2983 2984 120 common/image.c Start initial ramdisk verification 2985 -120 common/image.c Ramdisk FIT image has incorrect format 2986 121 common/image.c Ramdisk FIT image has correct format 2987 122 common/image.c No ramdisk subimage unit name, using configuration 2988 -122 common/image.c Can't get configuration for ramdisk subimage 2989 123 common/image.c Ramdisk unit name specified 2990 -124 common/image.c Can't get ramdisk subimage node offset 2991 125 common/image.c Got ramdisk subimage node offset 2992 -125 common/image.c Ramdisk subimage hash verification failed 2993 126 common/image.c Ramdisk subimage hash verification OK 2994 -126 common/image.c Ramdisk subimage for unsupported architecture 2995 127 common/image.c Architecture check OK 2996 -127 common/image.c Can't get ramdisk subimage data/size 2997 128 common/image.c Got ramdisk subimage data/size 2998 129 common/image.c Can't get ramdisk load address 2999 -129 common/image.c Got ramdisk load address 3000 3001 -130 common/cmd_doc.c Incorrect FIT image format 3002 131 common/cmd_doc.c FIT image format OK 3003 3004 -140 common/cmd_ide.c Incorrect FIT image format 3005 141 common/cmd_ide.c FIT image format OK 3006 3007 -150 common/cmd_nand.c Incorrect FIT image format 3008 151 common/cmd_nand.c FIT image format OK 3009 3010- legacy image format: 3011 CONFIG_IMAGE_FORMAT_LEGACY 3012 enables the legacy image format support in U-Boot. 3013 3014 Default: 3015 enabled if CONFIG_FIT_SIGNATURE is not defined. 3016 3017 CONFIG_DISABLE_IMAGE_LEGACY 3018 disable the legacy image format 3019 3020 This define is introduced, as the legacy image format is 3021 enabled per default for backward compatibility. 3022 3023- FIT image support: 3024 CONFIG_FIT_DISABLE_SHA256 3025 Supporting SHA256 hashes has quite an impact on binary size. 3026 For constrained systems sha256 hash support can be disabled 3027 with this option. 3028 3029 TODO(sjg@chromium.org): Adjust this option to be positive, 3030 and move it to Kconfig 3031 3032- Standalone program support: 3033 CONFIG_STANDALONE_LOAD_ADDR 3034 3035 This option defines a board specific value for the 3036 address where standalone program gets loaded, thus 3037 overwriting the architecture dependent default 3038 settings. 3039 3040- Frame Buffer Address: 3041 CONFIG_FB_ADDR 3042 3043 Define CONFIG_FB_ADDR if you want to use specific 3044 address for frame buffer. This is typically the case 3045 when using a graphics controller has separate video 3046 memory. U-Boot will then place the frame buffer at 3047 the given address instead of dynamically reserving it 3048 in system RAM by calling lcd_setmem(), which grabs 3049 the memory for the frame buffer depending on the 3050 configured panel size. 3051 3052 Please see board_init_f function. 3053 3054- Automatic software updates via TFTP server 3055 CONFIG_UPDATE_TFTP 3056 CONFIG_UPDATE_TFTP_CNT_MAX 3057 CONFIG_UPDATE_TFTP_MSEC_MAX 3058 3059 These options enable and control the auto-update feature; 3060 for a more detailed description refer to doc/README.update. 3061 3062- MTD Support (mtdparts command, UBI support) 3063 CONFIG_MTD_DEVICE 3064 3065 Adds the MTD device infrastructure from the Linux kernel. 3066 Needed for mtdparts command support. 3067 3068 CONFIG_MTD_PARTITIONS 3069 3070 Adds the MTD partitioning infrastructure from the Linux 3071 kernel. Needed for UBI support. 3072 3073- UBI support 3074 CONFIG_CMD_UBI 3075 3076 Adds commands for interacting with MTD partitions formatted 3077 with the UBI flash translation layer 3078 3079 Requires also defining CONFIG_RBTREE 3080 3081 CONFIG_UBI_SILENCE_MSG 3082 3083 Make the verbose messages from UBI stop printing. This leaves 3084 warnings and errors enabled. 3085 3086 3087 CONFIG_MTD_UBI_WL_THRESHOLD 3088 This parameter defines the maximum difference between the highest 3089 erase counter value and the lowest erase counter value of eraseblocks 3090 of UBI devices. When this threshold is exceeded, UBI starts performing 3091 wear leveling by means of moving data from eraseblock with low erase 3092 counter to eraseblocks with high erase counter. 3093 3094 The default value should be OK for SLC NAND flashes, NOR flashes and 3095 other flashes which have eraseblock life-cycle 100000 or more. 3096 However, in case of MLC NAND flashes which typically have eraseblock 3097 life-cycle less than 10000, the threshold should be lessened (e.g., 3098 to 128 or 256, although it does not have to be power of 2). 3099 3100 default: 4096 3101 3102 CONFIG_MTD_UBI_BEB_LIMIT 3103 This option specifies the maximum bad physical eraseblocks UBI 3104 expects on the MTD device (per 1024 eraseblocks). If the 3105 underlying flash does not admit of bad eraseblocks (e.g. NOR 3106 flash), this value is ignored. 3107 3108 NAND datasheets often specify the minimum and maximum NVM 3109 (Number of Valid Blocks) for the flashes' endurance lifetime. 3110 The maximum expected bad eraseblocks per 1024 eraseblocks 3111 then can be calculated as "1024 * (1 - MinNVB / MaxNVB)", 3112 which gives 20 for most NANDs (MaxNVB is basically the total 3113 count of eraseblocks on the chip). 3114 3115 To put it differently, if this value is 20, UBI will try to 3116 reserve about 1.9% of physical eraseblocks for bad blocks 3117 handling. And that will be 1.9% of eraseblocks on the entire 3118 NAND chip, not just the MTD partition UBI attaches. This means 3119 that if you have, say, a NAND flash chip admits maximum 40 bad 3120 eraseblocks, and it is split on two MTD partitions of the same 3121 size, UBI will reserve 40 eraseblocks when attaching a 3122 partition. 3123 3124 default: 20 3125 3126 CONFIG_MTD_UBI_FASTMAP 3127 Fastmap is a mechanism which allows attaching an UBI device 3128 in nearly constant time. Instead of scanning the whole MTD device it 3129 only has to locate a checkpoint (called fastmap) on the device. 3130 The on-flash fastmap contains all information needed to attach 3131 the device. Using fastmap makes only sense on large devices where 3132 attaching by scanning takes long. UBI will not automatically install 3133 a fastmap on old images, but you can set the UBI parameter 3134 CONFIG_MTD_UBI_FASTMAP_AUTOCONVERT to 1 if you want so. Please note 3135 that fastmap-enabled images are still usable with UBI implementations 3136 without fastmap support. On typical flash devices the whole fastmap 3137 fits into one PEB. UBI will reserve PEBs to hold two fastmaps. 3138 3139 CONFIG_MTD_UBI_FASTMAP_AUTOCONVERT 3140 Set this parameter to enable fastmap automatically on images 3141 without a fastmap. 3142 default: 0 3143 3144 CONFIG_MTD_UBI_FM_DEBUG 3145 Enable UBI fastmap debug 3146 default: 0 3147 3148- UBIFS support 3149 CONFIG_CMD_UBIFS 3150 3151 Adds commands for interacting with UBI volumes formatted as 3152 UBIFS. UBIFS is read-only in u-boot. 3153 3154 Requires UBI support as well as CONFIG_LZO 3155 3156 CONFIG_UBIFS_SILENCE_MSG 3157 3158 Make the verbose messages from UBIFS stop printing. This leaves 3159 warnings and errors enabled. 3160 3161- SPL framework 3162 CONFIG_SPL 3163 Enable building of SPL globally. 3164 3165 CONFIG_SPL_LDSCRIPT 3166 LDSCRIPT for linking the SPL binary. 3167 3168 CONFIG_SPL_MAX_FOOTPRINT 3169 Maximum size in memory allocated to the SPL, BSS included. 3170 When defined, the linker checks that the actual memory 3171 used by SPL from _start to __bss_end does not exceed it. 3172 CONFIG_SPL_MAX_FOOTPRINT and CONFIG_SPL_BSS_MAX_SIZE 3173 must not be both defined at the same time. 3174 3175 CONFIG_SPL_MAX_SIZE 3176 Maximum size of the SPL image (text, data, rodata, and 3177 linker lists sections), BSS excluded. 3178 When defined, the linker checks that the actual size does 3179 not exceed it. 3180 3181 CONFIG_SPL_TEXT_BASE 3182 TEXT_BASE for linking the SPL binary. 3183 3184 CONFIG_SPL_RELOC_TEXT_BASE 3185 Address to relocate to. If unspecified, this is equal to 3186 CONFIG_SPL_TEXT_BASE (i.e. no relocation is done). 3187 3188 CONFIG_SPL_BSS_START_ADDR 3189 Link address for the BSS within the SPL binary. 3190 3191 CONFIG_SPL_BSS_MAX_SIZE 3192 Maximum size in memory allocated to the SPL BSS. 3193 When defined, the linker checks that the actual memory used 3194 by SPL from __bss_start to __bss_end does not exceed it. 3195 CONFIG_SPL_MAX_FOOTPRINT and CONFIG_SPL_BSS_MAX_SIZE 3196 must not be both defined at the same time. 3197 3198 CONFIG_SPL_STACK 3199 Adress of the start of the stack SPL will use 3200 3201 CONFIG_SPL_PANIC_ON_RAW_IMAGE 3202 When defined, SPL will panic() if the image it has 3203 loaded does not have a signature. 3204 Defining this is useful when code which loads images 3205 in SPL cannot guarantee that absolutely all read errors 3206 will be caught. 3207 An example is the LPC32XX MLC NAND driver, which will 3208 consider that a completely unreadable NAND block is bad, 3209 and thus should be skipped silently. 3210 3211 CONFIG_SPL_RELOC_STACK 3212 Adress of the start of the stack SPL will use after 3213 relocation. If unspecified, this is equal to 3214 CONFIG_SPL_STACK. 3215 3216 CONFIG_SYS_SPL_MALLOC_START 3217 Starting address of the malloc pool used in SPL. 3218 When this option is set the full malloc is used in SPL and 3219 it is set up by spl_init() and before that, the simple malloc() 3220 can be used if CONFIG_SYS_MALLOC_F is defined. 3221 3222 CONFIG_SYS_SPL_MALLOC_SIZE 3223 The size of the malloc pool used in SPL. 3224 3225 CONFIG_SPL_FRAMEWORK 3226 Enable the SPL framework under common/. This framework 3227 supports MMC, NAND and YMODEM loading of U-Boot and NAND 3228 NAND loading of the Linux Kernel. 3229 3230 CONFIG_SPL_OS_BOOT 3231 Enable booting directly to an OS from SPL. 3232 See also: doc/README.falcon 3233 3234 CONFIG_SPL_DISPLAY_PRINT 3235 For ARM, enable an optional function to print more information 3236 about the running system. 3237 3238 CONFIG_SPL_INIT_MINIMAL 3239 Arch init code should be built for a very small image 3240 3241 CONFIG_SYS_MMCSD_RAW_MODE_U_BOOT_PARTITION 3242 Partition on the MMC to load U-Boot from when the MMC is being 3243 used in raw mode 3244 3245 CONFIG_SYS_MMCSD_RAW_MODE_KERNEL_SECTOR 3246 Sector to load kernel uImage from when MMC is being 3247 used in raw mode (for Falcon mode) 3248 3249 CONFIG_SYS_MMCSD_RAW_MODE_ARGS_SECTOR, 3250 CONFIG_SYS_MMCSD_RAW_MODE_ARGS_SECTORS 3251 Sector and number of sectors to load kernel argument 3252 parameters from when MMC is being used in raw mode 3253 (for falcon mode) 3254 3255 CONFIG_SYS_MMCSD_FS_BOOT_PARTITION 3256 Partition on the MMC to load U-Boot from when the MMC is being 3257 used in fs mode 3258 3259 CONFIG_SPL_FS_LOAD_PAYLOAD_NAME 3260 Filename to read to load U-Boot when reading from filesystem 3261 3262 CONFIG_SPL_FS_LOAD_KERNEL_NAME 3263 Filename to read to load kernel uImage when reading 3264 from filesystem (for Falcon mode) 3265 3266 CONFIG_SPL_FS_LOAD_ARGS_NAME 3267 Filename to read to load kernel argument parameters 3268 when reading from filesystem (for Falcon mode) 3269 3270 CONFIG_SPL_MPC83XX_WAIT_FOR_NAND 3271 Set this for NAND SPL on PPC mpc83xx targets, so that 3272 start.S waits for the rest of the SPL to load before 3273 continuing (the hardware starts execution after just 3274 loading the first page rather than the full 4K). 3275 3276 CONFIG_SPL_SKIP_RELOCATE 3277 Avoid SPL relocation 3278 3279 CONFIG_SPL_NAND_BASE 3280 Include nand_base.c in the SPL. Requires 3281 CONFIG_SPL_NAND_DRIVERS. 3282 3283 CONFIG_SPL_NAND_DRIVERS 3284 SPL uses normal NAND drivers, not minimal drivers. 3285 3286 CONFIG_SPL_NAND_ECC 3287 Include standard software ECC in the SPL 3288 3289 CONFIG_SPL_NAND_SIMPLE 3290 Support for NAND boot using simple NAND drivers that 3291 expose the cmd_ctrl() interface. 3292 3293 CONFIG_SPL_UBI 3294 Support for a lightweight UBI (fastmap) scanner and 3295 loader 3296 3297 CONFIG_SPL_NAND_RAW_ONLY 3298 Support to boot only raw u-boot.bin images. Use this only 3299 if you need to save space. 3300 3301 CONFIG_SPL_COMMON_INIT_DDR 3302 Set for common ddr init with serial presence detect in 3303 SPL binary. 3304 3305 CONFIG_SYS_NAND_5_ADDR_CYCLE, CONFIG_SYS_NAND_PAGE_COUNT, 3306 CONFIG_SYS_NAND_PAGE_SIZE, CONFIG_SYS_NAND_OOBSIZE, 3307 CONFIG_SYS_NAND_BLOCK_SIZE, CONFIG_SYS_NAND_BAD_BLOCK_POS, 3308 CONFIG_SYS_NAND_ECCPOS, CONFIG_SYS_NAND_ECCSIZE, 3309 CONFIG_SYS_NAND_ECCBYTES 3310 Defines the size and behavior of the NAND that SPL uses 3311 to read U-Boot 3312 3313 CONFIG_SPL_NAND_BOOT 3314 Add support NAND boot 3315 3316 CONFIG_SYS_NAND_U_BOOT_OFFS 3317 Location in NAND to read U-Boot from 3318 3319 CONFIG_SYS_NAND_U_BOOT_DST 3320 Location in memory to load U-Boot to 3321 3322 CONFIG_SYS_NAND_U_BOOT_SIZE 3323 Size of image to load 3324 3325 CONFIG_SYS_NAND_U_BOOT_START 3326 Entry point in loaded image to jump to 3327 3328 CONFIG_SYS_NAND_HW_ECC_OOBFIRST 3329 Define this if you need to first read the OOB and then the 3330 data. This is used, for example, on davinci platforms. 3331 3332 CONFIG_SPL_OMAP3_ID_NAND 3333 Support for an OMAP3-specific set of functions to return the 3334 ID and MFR of the first attached NAND chip, if present. 3335 3336 CONFIG_SPL_RAM_DEVICE 3337 Support for running image already present in ram, in SPL binary 3338 3339 CONFIG_SPL_PAD_TO 3340 Image offset to which the SPL should be padded before appending 3341 the SPL payload. By default, this is defined as 3342 CONFIG_SPL_MAX_SIZE, or 0 if CONFIG_SPL_MAX_SIZE is undefined. 3343 CONFIG_SPL_PAD_TO must be either 0, meaning to append the SPL 3344 payload without any padding, or >= CONFIG_SPL_MAX_SIZE. 3345 3346 CONFIG_SPL_TARGET 3347 Final target image containing SPL and payload. Some SPLs 3348 use an arch-specific makefile fragment instead, for 3349 example if more than one image needs to be produced. 3350 3351 CONFIG_FIT_SPL_PRINT 3352 Printing information about a FIT image adds quite a bit of 3353 code to SPL. So this is normally disabled in SPL. Use this 3354 option to re-enable it. This will affect the output of the 3355 bootm command when booting a FIT image. 3356 3357- TPL framework 3358 CONFIG_TPL 3359 Enable building of TPL globally. 3360 3361 CONFIG_TPL_PAD_TO 3362 Image offset to which the TPL should be padded before appending 3363 the TPL payload. By default, this is defined as 3364 CONFIG_SPL_MAX_SIZE, or 0 if CONFIG_SPL_MAX_SIZE is undefined. 3365 CONFIG_SPL_PAD_TO must be either 0, meaning to append the SPL 3366 payload without any padding, or >= CONFIG_SPL_MAX_SIZE. 3367 3368- Interrupt support (PPC): 3369 3370 There are common interrupt_init() and timer_interrupt() 3371 for all PPC archs. interrupt_init() calls interrupt_init_cpu() 3372 for CPU specific initialization. interrupt_init_cpu() 3373 should set decrementer_count to appropriate value. If 3374 CPU resets decrementer automatically after interrupt 3375 (ppc4xx) it should set decrementer_count to zero. 3376 timer_interrupt() calls timer_interrupt_cpu() for CPU 3377 specific handling. If board has watchdog / status_led 3378 / other_activity_monitor it works automatically from 3379 general timer_interrupt(). 3380 3381 3382Board initialization settings: 3383------------------------------ 3384 3385During Initialization u-boot calls a number of board specific functions 3386to allow the preparation of board specific prerequisites, e.g. pin setup 3387before drivers are initialized. To enable these callbacks the 3388following configuration macros have to be defined. Currently this is 3389architecture specific, so please check arch/your_architecture/lib/board.c 3390typically in board_init_f() and board_init_r(). 3391 3392- CONFIG_BOARD_EARLY_INIT_F: Call board_early_init_f() 3393- CONFIG_BOARD_EARLY_INIT_R: Call board_early_init_r() 3394- CONFIG_BOARD_LATE_INIT: Call board_late_init() 3395- CONFIG_BOARD_POSTCLK_INIT: Call board_postclk_init() 3396 3397Configuration Settings: 3398----------------------- 3399 3400- CONFIG_SYS_SUPPORT_64BIT_DATA: Defined automatically if compiled as 64-bit. 3401 Optionally it can be defined to support 64-bit memory commands. 3402 3403- CONFIG_SYS_LONGHELP: Defined when you want long help messages included; 3404 undefine this when you're short of memory. 3405 3406- CONFIG_SYS_HELP_CMD_WIDTH: Defined when you want to override the default 3407 width of the commands listed in the 'help' command output. 3408 3409- CONFIG_SYS_PROMPT: This is what U-Boot prints on the console to 3410 prompt for user input. 3411 3412- CONFIG_SYS_CBSIZE: Buffer size for input from the Console 3413 3414- CONFIG_SYS_PBSIZE: Buffer size for Console output 3415 3416- CONFIG_SYS_MAXARGS: max. Number of arguments accepted for monitor commands 3417 3418- CONFIG_SYS_BARGSIZE: Buffer size for Boot Arguments which are passed to 3419 the application (usually a Linux kernel) when it is 3420 booted 3421 3422- CONFIG_SYS_BAUDRATE_TABLE: 3423 List of legal baudrate settings for this board. 3424 3425- CONFIG_SYS_MEMTEST_START, CONFIG_SYS_MEMTEST_END: 3426 Begin and End addresses of the area used by the 3427 simple memory test. 3428 3429- CONFIG_SYS_ALT_MEMTEST: 3430 Enable an alternate, more extensive memory test. 3431 3432- CONFIG_SYS_MEMTEST_SCRATCH: 3433 Scratch address used by the alternate memory test 3434 You only need to set this if address zero isn't writeable 3435 3436- CONFIG_SYS_MEM_RESERVE_SECURE 3437 Only implemented for ARMv8 for now. 3438 If defined, the size of CONFIG_SYS_MEM_RESERVE_SECURE memory 3439 is substracted from total RAM and won't be reported to OS. 3440 This memory can be used as secure memory. A variable 3441 gd->arch.secure_ram is used to track the location. In systems 3442 the RAM base is not zero, or RAM is divided into banks, 3443 this variable needs to be recalcuated to get the address. 3444 3445- CONFIG_SYS_MEM_TOP_HIDE: 3446 If CONFIG_SYS_MEM_TOP_HIDE is defined in the board config header, 3447 this specified memory area will get subtracted from the top 3448 (end) of RAM and won't get "touched" at all by U-Boot. By 3449 fixing up gd->ram_size the Linux kernel should gets passed 3450 the now "corrected" memory size and won't touch it either. 3451 This should work for arch/ppc and arch/powerpc. Only Linux 3452 board ports in arch/powerpc with bootwrapper support that 3453 recalculate the memory size from the SDRAM controller setup 3454 will have to get fixed in Linux additionally. 3455 3456 This option can be used as a workaround for the 440EPx/GRx 3457 CHIP 11 errata where the last 256 bytes in SDRAM shouldn't 3458 be touched. 3459 3460 WARNING: Please make sure that this value is a multiple of 3461 the Linux page size (normally 4k). If this is not the case, 3462 then the end address of the Linux memory will be located at a 3463 non page size aligned address and this could cause major 3464 problems. 3465 3466- CONFIG_SYS_LOADS_BAUD_CHANGE: 3467 Enable temporary baudrate change while serial download 3468 3469- CONFIG_SYS_SDRAM_BASE: 3470 Physical start address of SDRAM. _Must_ be 0 here. 3471 3472- CONFIG_SYS_FLASH_BASE: 3473 Physical start address of Flash memory. 3474 3475- CONFIG_SYS_MONITOR_BASE: 3476 Physical start address of boot monitor code (set by 3477 make config files to be same as the text base address 3478 (CONFIG_SYS_TEXT_BASE) used when linking) - same as 3479 CONFIG_SYS_FLASH_BASE when booting from flash. 3480 3481- CONFIG_SYS_MONITOR_LEN: 3482 Size of memory reserved for monitor code, used to 3483 determine _at_compile_time_ (!) if the environment is 3484 embedded within the U-Boot image, or in a separate 3485 flash sector. 3486 3487- CONFIG_SYS_MALLOC_LEN: 3488 Size of DRAM reserved for malloc() use. 3489 3490- CONFIG_SYS_MALLOC_F_LEN 3491 Size of the malloc() pool for use before relocation. If 3492 this is defined, then a very simple malloc() implementation 3493 will become available before relocation. The address is just 3494 below the global data, and the stack is moved down to make 3495 space. 3496 3497 This feature allocates regions with increasing addresses 3498 within the region. calloc() is supported, but realloc() 3499 is not available. free() is supported but does nothing. 3500 The memory will be freed (or in fact just forgotten) when 3501 U-Boot relocates itself. 3502 3503- CONFIG_SYS_MALLOC_SIMPLE 3504 Provides a simple and small malloc() and calloc() for those 3505 boards which do not use the full malloc in SPL (which is 3506 enabled with CONFIG_SYS_SPL_MALLOC_START). 3507 3508- CONFIG_SYS_NONCACHED_MEMORY: 3509 Size of non-cached memory area. This area of memory will be 3510 typically located right below the malloc() area and mapped 3511 uncached in the MMU. This is useful for drivers that would 3512 otherwise require a lot of explicit cache maintenance. For 3513 some drivers it's also impossible to properly maintain the 3514 cache. For example if the regions that need to be flushed 3515 are not a multiple of the cache-line size, *and* padding 3516 cannot be allocated between the regions to align them (i.e. 3517 if the HW requires a contiguous array of regions, and the 3518 size of each region is not cache-aligned), then a flush of 3519 one region may result in overwriting data that hardware has 3520 written to another region in the same cache-line. This can 3521 happen for example in network drivers where descriptors for 3522 buffers are typically smaller than the CPU cache-line (e.g. 3523 16 bytes vs. 32 or 64 bytes). 3524 3525 Non-cached memory is only supported on 32-bit ARM at present. 3526 3527- CONFIG_SYS_BOOTM_LEN: 3528 Normally compressed uImages are limited to an 3529 uncompressed size of 8 MBytes. If this is not enough, 3530 you can define CONFIG_SYS_BOOTM_LEN in your board config file 3531 to adjust this setting to your needs. 3532 3533- CONFIG_SYS_BOOTMAPSZ: 3534 Maximum size of memory mapped by the startup code of 3535 the Linux kernel; all data that must be processed by 3536 the Linux kernel (bd_info, boot arguments, FDT blob if 3537 used) must be put below this limit, unless "bootm_low" 3538 environment variable is defined and non-zero. In such case 3539 all data for the Linux kernel must be between "bootm_low" 3540 and "bootm_low" + CONFIG_SYS_BOOTMAPSZ. The environment 3541 variable "bootm_mapsize" will override the value of 3542 CONFIG_SYS_BOOTMAPSZ. If CONFIG_SYS_BOOTMAPSZ is undefined, 3543 then the value in "bootm_size" will be used instead. 3544 3545- CONFIG_SYS_BOOT_RAMDISK_HIGH: 3546 Enable initrd_high functionality. If defined then the 3547 initrd_high feature is enabled and the bootm ramdisk subcommand 3548 is enabled. 3549 3550- CONFIG_SYS_BOOT_GET_CMDLINE: 3551 Enables allocating and saving kernel cmdline in space between 3552 "bootm_low" and "bootm_low" + BOOTMAPSZ. 3553 3554- CONFIG_SYS_BOOT_GET_KBD: 3555 Enables allocating and saving a kernel copy of the bd_info in 3556 space between "bootm_low" and "bootm_low" + BOOTMAPSZ. 3557 3558- CONFIG_SYS_MAX_FLASH_BANKS: 3559 Max number of Flash memory banks 3560 3561- CONFIG_SYS_MAX_FLASH_SECT: 3562 Max number of sectors on a Flash chip 3563 3564- CONFIG_SYS_FLASH_ERASE_TOUT: 3565 Timeout for Flash erase operations (in ms) 3566 3567- CONFIG_SYS_FLASH_WRITE_TOUT: 3568 Timeout for Flash write operations (in ms) 3569 3570- CONFIG_SYS_FLASH_LOCK_TOUT 3571 Timeout for Flash set sector lock bit operation (in ms) 3572 3573- CONFIG_SYS_FLASH_UNLOCK_TOUT 3574 Timeout for Flash clear lock bits operation (in ms) 3575 3576- CONFIG_SYS_FLASH_PROTECTION 3577 If defined, hardware flash sectors protection is used 3578 instead of U-Boot software protection. 3579 3580- CONFIG_SYS_DIRECT_FLASH_TFTP: 3581 3582 Enable TFTP transfers directly to flash memory; 3583 without this option such a download has to be 3584 performed in two steps: (1) download to RAM, and (2) 3585 copy from RAM to flash. 3586 3587 The two-step approach is usually more reliable, since 3588 you can check if the download worked before you erase 3589 the flash, but in some situations (when system RAM is 3590 too limited to allow for a temporary copy of the 3591 downloaded image) this option may be very useful. 3592 3593- CONFIG_SYS_FLASH_CFI: 3594 Define if the flash driver uses extra elements in the 3595 common flash structure for storing flash geometry. 3596 3597- CONFIG_FLASH_CFI_DRIVER 3598 This option also enables the building of the cfi_flash driver 3599 in the drivers directory 3600 3601- CONFIG_FLASH_CFI_MTD 3602 This option enables the building of the cfi_mtd driver 3603 in the drivers directory. The driver exports CFI flash 3604 to the MTD layer. 3605 3606- CONFIG_SYS_FLASH_USE_BUFFER_WRITE 3607 Use buffered writes to flash. 3608 3609- CONFIG_FLASH_SPANSION_S29WS_N 3610 s29ws-n MirrorBit flash has non-standard addresses for buffered 3611 write commands. 3612 3613- CONFIG_SYS_FLASH_QUIET_TEST 3614 If this option is defined, the common CFI flash doesn't 3615 print it's warning upon not recognized FLASH banks. This 3616 is useful, if some of the configured banks are only 3617 optionally available. 3618 3619- CONFIG_FLASH_SHOW_PROGRESS 3620 If defined (must be an integer), print out countdown 3621 digits and dots. Recommended value: 45 (9..1) for 80 3622 column displays, 15 (3..1) for 40 column displays. 3623 3624- CONFIG_FLASH_VERIFY 3625 If defined, the content of the flash (destination) is compared 3626 against the source after the write operation. An error message 3627 will be printed when the contents are not identical. 3628 Please note that this option is useless in nearly all cases, 3629 since such flash programming errors usually are detected earlier 3630 while unprotecting/erasing/programming. Please only enable 3631 this option if you really know what you are doing. 3632 3633- CONFIG_SYS_RX_ETH_BUFFER: 3634 Defines the number of Ethernet receive buffers. On some 3635 Ethernet controllers it is recommended to set this value 3636 to 8 or even higher (EEPRO100 or 405 EMAC), since all 3637 buffers can be full shortly after enabling the interface 3638 on high Ethernet traffic. 3639 Defaults to 4 if not defined. 3640 3641- CONFIG_ENV_MAX_ENTRIES 3642 3643 Maximum number of entries in the hash table that is used 3644 internally to store the environment settings. The default 3645 setting is supposed to be generous and should work in most 3646 cases. This setting can be used to tune behaviour; see 3647 lib/hashtable.c for details. 3648 3649- CONFIG_ENV_FLAGS_LIST_DEFAULT 3650- CONFIG_ENV_FLAGS_LIST_STATIC 3651 Enable validation of the values given to environment variables when 3652 calling env set. Variables can be restricted to only decimal, 3653 hexadecimal, or boolean. If CONFIG_CMD_NET is also defined, 3654 the variables can also be restricted to IP address or MAC address. 3655 3656 The format of the list is: 3657 type_attribute = [s|d|x|b|i|m] 3658 access_attribute = [a|r|o|c] 3659 attributes = type_attribute[access_attribute] 3660 entry = variable_name[:attributes] 3661 list = entry[,list] 3662 3663 The type attributes are: 3664 s - String (default) 3665 d - Decimal 3666 x - Hexadecimal 3667 b - Boolean ([1yYtT|0nNfF]) 3668 i - IP address 3669 m - MAC address 3670 3671 The access attributes are: 3672 a - Any (default) 3673 r - Read-only 3674 o - Write-once 3675 c - Change-default 3676 3677 - CONFIG_ENV_FLAGS_LIST_DEFAULT 3678 Define this to a list (string) to define the ".flags" 3679 environment variable in the default or embedded environment. 3680 3681 - CONFIG_ENV_FLAGS_LIST_STATIC 3682 Define this to a list (string) to define validation that 3683 should be done if an entry is not found in the ".flags" 3684 environment variable. To override a setting in the static 3685 list, simply add an entry for the same variable name to the 3686 ".flags" variable. 3687 3688 If CONFIG_REGEX is defined, the variable_name above is evaluated as a 3689 regular expression. This allows multiple variables to define the same 3690 flags without explicitly listing them for each variable. 3691 3692- CONFIG_ENV_ACCESS_IGNORE_FORCE 3693 If defined, don't allow the -f switch to env set override variable 3694 access flags. 3695 3696- CONFIG_OMAP_PLATFORM_RESET_TIME_MAX_USEC (OMAP only) 3697 This is set by OMAP boards for the max time that reset should 3698 be asserted. See doc/README.omap-reset-time for details on how 3699 the value can be calculated on a given board. 3700 3701- CONFIG_USE_STDINT 3702 If stdint.h is available with your toolchain you can define this 3703 option to enable it. You can provide option 'USE_STDINT=1' when 3704 building U-Boot to enable this. 3705 3706The following definitions that deal with the placement and management 3707of environment data (variable area); in general, we support the 3708following configurations: 3709 3710- CONFIG_BUILD_ENVCRC: 3711 3712 Builds up envcrc with the target environment so that external utils 3713 may easily extract it and embed it in final U-Boot images. 3714 3715- CONFIG_ENV_IS_IN_FLASH: 3716 3717 Define this if the environment is in flash memory. 3718 3719 a) The environment occupies one whole flash sector, which is 3720 "embedded" in the text segment with the U-Boot code. This 3721 happens usually with "bottom boot sector" or "top boot 3722 sector" type flash chips, which have several smaller 3723 sectors at the start or the end. For instance, such a 3724 layout can have sector sizes of 8, 2x4, 16, Nx32 kB. In 3725 such a case you would place the environment in one of the 3726 4 kB sectors - with U-Boot code before and after it. With 3727 "top boot sector" type flash chips, you would put the 3728 environment in one of the last sectors, leaving a gap 3729 between U-Boot and the environment. 3730 3731 - CONFIG_ENV_OFFSET: 3732 3733 Offset of environment data (variable area) to the 3734 beginning of flash memory; for instance, with bottom boot 3735 type flash chips the second sector can be used: the offset 3736 for this sector is given here. 3737 3738 CONFIG_ENV_OFFSET is used relative to CONFIG_SYS_FLASH_BASE. 3739 3740 - CONFIG_ENV_ADDR: 3741 3742 This is just another way to specify the start address of 3743 the flash sector containing the environment (instead of 3744 CONFIG_ENV_OFFSET). 3745 3746 - CONFIG_ENV_SECT_SIZE: 3747 3748 Size of the sector containing the environment. 3749 3750 3751 b) Sometimes flash chips have few, equal sized, BIG sectors. 3752 In such a case you don't want to spend a whole sector for 3753 the environment. 3754 3755 - CONFIG_ENV_SIZE: 3756 3757 If you use this in combination with CONFIG_ENV_IS_IN_FLASH 3758 and CONFIG_ENV_SECT_SIZE, you can specify to use only a part 3759 of this flash sector for the environment. This saves 3760 memory for the RAM copy of the environment. 3761 3762 It may also save flash memory if you decide to use this 3763 when your environment is "embedded" within U-Boot code, 3764 since then the remainder of the flash sector could be used 3765 for U-Boot code. It should be pointed out that this is 3766 STRONGLY DISCOURAGED from a robustness point of view: 3767 updating the environment in flash makes it always 3768 necessary to erase the WHOLE sector. If something goes 3769 wrong before the contents has been restored from a copy in 3770 RAM, your target system will be dead. 3771 3772 - CONFIG_ENV_ADDR_REDUND 3773 CONFIG_ENV_SIZE_REDUND 3774 3775 These settings describe a second storage area used to hold 3776 a redundant copy of the environment data, so that there is 3777 a valid backup copy in case there is a power failure during 3778 a "saveenv" operation. 3779 3780BE CAREFUL! Any changes to the flash layout, and some changes to the 3781source code will make it necessary to adapt <board>/u-boot.lds* 3782accordingly! 3783 3784 3785- CONFIG_ENV_IS_IN_NVRAM: 3786 3787 Define this if you have some non-volatile memory device 3788 (NVRAM, battery buffered SRAM) which you want to use for the 3789 environment. 3790 3791 - CONFIG_ENV_ADDR: 3792 - CONFIG_ENV_SIZE: 3793 3794 These two #defines are used to determine the memory area you 3795 want to use for environment. It is assumed that this memory 3796 can just be read and written to, without any special 3797 provision. 3798 3799BE CAREFUL! The first access to the environment happens quite early 3800in U-Boot initialization (when we try to get the setting of for the 3801console baudrate). You *MUST* have mapped your NVRAM area then, or 3802U-Boot will hang. 3803 3804Please note that even with NVRAM we still use a copy of the 3805environment in RAM: we could work on NVRAM directly, but we want to 3806keep settings there always unmodified except somebody uses "saveenv" 3807to save the current settings. 3808 3809 3810- CONFIG_ENV_IS_IN_EEPROM: 3811 3812 Use this if you have an EEPROM or similar serial access 3813 device and a driver for it. 3814 3815 - CONFIG_ENV_OFFSET: 3816 - CONFIG_ENV_SIZE: 3817 3818 These two #defines specify the offset and size of the 3819 environment area within the total memory of your EEPROM. 3820 3821 - CONFIG_SYS_I2C_EEPROM_ADDR: 3822 If defined, specified the chip address of the EEPROM device. 3823 The default address is zero. 3824 3825 - CONFIG_SYS_I2C_EEPROM_BUS: 3826 If defined, specified the i2c bus of the EEPROM device. 3827 3828 - CONFIG_SYS_EEPROM_PAGE_WRITE_BITS: 3829 If defined, the number of bits used to address bytes in a 3830 single page in the EEPROM device. A 64 byte page, for example 3831 would require six bits. 3832 3833 - CONFIG_SYS_EEPROM_PAGE_WRITE_DELAY_MS: 3834 If defined, the number of milliseconds to delay between 3835 page writes. The default is zero milliseconds. 3836 3837 - CONFIG_SYS_I2C_EEPROM_ADDR_LEN: 3838 The length in bytes of the EEPROM memory array address. Note 3839 that this is NOT the chip address length! 3840 3841 - CONFIG_SYS_I2C_EEPROM_ADDR_OVERFLOW: 3842 EEPROM chips that implement "address overflow" are ones 3843 like Catalyst 24WC04/08/16 which has 9/10/11 bits of 3844 address and the extra bits end up in the "chip address" bit 3845 slots. This makes a 24WC08 (1Kbyte) chip look like four 256 3846 byte chips. 3847 3848 Note that we consider the length of the address field to 3849 still be one byte because the extra address bits are hidden 3850 in the chip address. 3851 3852 - CONFIG_SYS_EEPROM_SIZE: 3853 The size in bytes of the EEPROM device. 3854 3855 - CONFIG_ENV_EEPROM_IS_ON_I2C 3856 define this, if you have I2C and SPI activated, and your 3857 EEPROM, which holds the environment, is on the I2C bus. 3858 3859 - CONFIG_I2C_ENV_EEPROM_BUS 3860 if you have an Environment on an EEPROM reached over 3861 I2C muxes, you can define here, how to reach this 3862 EEPROM. For example: 3863 3864 #define CONFIG_I2C_ENV_EEPROM_BUS 1 3865 3866 EEPROM which holds the environment, is reached over 3867 a pca9547 i2c mux with address 0x70, channel 3. 3868 3869- CONFIG_ENV_IS_IN_DATAFLASH: 3870 3871 Define this if you have a DataFlash memory device which you 3872 want to use for the environment. 3873 3874 - CONFIG_ENV_OFFSET: 3875 - CONFIG_ENV_ADDR: 3876 - CONFIG_ENV_SIZE: 3877 3878 These three #defines specify the offset and size of the 3879 environment area within the total memory of your DataFlash placed 3880 at the specified address. 3881 3882- CONFIG_ENV_IS_IN_SPI_FLASH: 3883 3884 Define this if you have a SPI Flash memory device which you 3885 want to use for the environment. 3886 3887 - CONFIG_ENV_OFFSET: 3888 - CONFIG_ENV_SIZE: 3889 3890 These two #defines specify the offset and size of the 3891 environment area within the SPI Flash. CONFIG_ENV_OFFSET must be 3892 aligned to an erase sector boundary. 3893 3894 - CONFIG_ENV_SECT_SIZE: 3895 3896 Define the SPI flash's sector size. 3897 3898 - CONFIG_ENV_OFFSET_REDUND (optional): 3899 3900 This setting describes a second storage area of CONFIG_ENV_SIZE 3901 size used to hold a redundant copy of the environment data, so 3902 that there is a valid backup copy in case there is a power failure 3903 during a "saveenv" operation. CONFIG_ENV_OFFSET_REDUND must be 3904 aligned to an erase sector boundary. 3905 3906 - CONFIG_ENV_SPI_BUS (optional): 3907 - CONFIG_ENV_SPI_CS (optional): 3908 3909 Define the SPI bus and chip select. If not defined they will be 0. 3910 3911 - CONFIG_ENV_SPI_MAX_HZ (optional): 3912 3913 Define the SPI max work clock. If not defined then use 1MHz. 3914 3915 - CONFIG_ENV_SPI_MODE (optional): 3916 3917 Define the SPI work mode. If not defined then use SPI_MODE_3. 3918 3919- CONFIG_ENV_IS_IN_REMOTE: 3920 3921 Define this if you have a remote memory space which you 3922 want to use for the local device's environment. 3923 3924 - CONFIG_ENV_ADDR: 3925 - CONFIG_ENV_SIZE: 3926 3927 These two #defines specify the address and size of the 3928 environment area within the remote memory space. The 3929 local device can get the environment from remote memory 3930 space by SRIO or PCIE links. 3931 3932BE CAREFUL! For some special cases, the local device can not use 3933"saveenv" command. For example, the local device will get the 3934environment stored in a remote NOR flash by SRIO or PCIE link, 3935but it can not erase, write this NOR flash by SRIO or PCIE interface. 3936 3937- CONFIG_ENV_IS_IN_NAND: 3938 3939 Define this if you have a NAND device which you want to use 3940 for the environment. 3941 3942 - CONFIG_ENV_OFFSET: 3943 - CONFIG_ENV_SIZE: 3944 3945 These two #defines specify the offset and size of the environment 3946 area within the first NAND device. CONFIG_ENV_OFFSET must be 3947 aligned to an erase block boundary. 3948 3949 - CONFIG_ENV_OFFSET_REDUND (optional): 3950 3951 This setting describes a second storage area of CONFIG_ENV_SIZE 3952 size used to hold a redundant copy of the environment data, so 3953 that there is a valid backup copy in case there is a power failure 3954 during a "saveenv" operation. CONFIG_ENV_OFFSET_REDUND must be 3955 aligned to an erase block boundary. 3956 3957 - CONFIG_ENV_RANGE (optional): 3958 3959 Specifies the length of the region in which the environment 3960 can be written. This should be a multiple of the NAND device's 3961 block size. Specifying a range with more erase blocks than 3962 are needed to hold CONFIG_ENV_SIZE allows bad blocks within 3963 the range to be avoided. 3964 3965 - CONFIG_ENV_OFFSET_OOB (optional): 3966 3967 Enables support for dynamically retrieving the offset of the 3968 environment from block zero's out-of-band data. The 3969 "nand env.oob" command can be used to record this offset. 3970 Currently, CONFIG_ENV_OFFSET_REDUND is not supported when 3971 using CONFIG_ENV_OFFSET_OOB. 3972 3973- CONFIG_NAND_ENV_DST 3974 3975 Defines address in RAM to which the nand_spl code should copy the 3976 environment. If redundant environment is used, it will be copied to 3977 CONFIG_NAND_ENV_DST + CONFIG_ENV_SIZE. 3978 3979- CONFIG_ENV_IS_IN_UBI: 3980 3981 Define this if you have an UBI volume that you want to use for the 3982 environment. This has the benefit of wear-leveling the environment 3983 accesses, which is important on NAND. 3984 3985 - CONFIG_ENV_UBI_PART: 3986 3987 Define this to a string that is the mtd partition containing the UBI. 3988 3989 - CONFIG_ENV_UBI_VOLUME: 3990 3991 Define this to the name of the volume that you want to store the 3992 environment in. 3993 3994 - CONFIG_ENV_UBI_VOLUME_REDUND: 3995 3996 Define this to the name of another volume to store a second copy of 3997 the environment in. This will enable redundant environments in UBI. 3998 It is assumed that both volumes are in the same MTD partition. 3999 4000 - CONFIG_UBI_SILENCE_MSG 4001 - CONFIG_UBIFS_SILENCE_MSG 4002 4003 You will probably want to define these to avoid a really noisy system 4004 when storing the env in UBI. 4005 4006- CONFIG_ENV_IS_IN_FAT: 4007 Define this if you want to use the FAT file system for the environment. 4008 4009 - FAT_ENV_INTERFACE: 4010 4011 Define this to a string that is the name of the block device. 4012 4013 - FAT_ENV_DEVICE_AND_PART: 4014 4015 Define this to a string to specify the partition of the device. It can 4016 be as following: 4017 4018 "D:P", "D:0", "D", "D:" or "D:auto" (D, P are integers. And P >= 1) 4019 - "D:P": device D partition P. Error occurs if device D has no 4020 partition table. 4021 - "D:0": device D. 4022 - "D" or "D:": device D partition 1 if device D has partition 4023 table, or the whole device D if has no partition 4024 table. 4025 - "D:auto": first partition in device D with bootable flag set. 4026 If none, first valid partition in device D. If no 4027 partition table then means device D. 4028 4029 - FAT_ENV_FILE: 4030 4031 It's a string of the FAT file name. This file use to store the 4032 environment. 4033 4034 - CONFIG_FAT_WRITE: 4035 This should be defined. Otherwise it cannot save the environment file. 4036 4037- CONFIG_ENV_IS_IN_MMC: 4038 4039 Define this if you have an MMC device which you want to use for the 4040 environment. 4041 4042 - CONFIG_SYS_MMC_ENV_DEV: 4043 4044 Specifies which MMC device the environment is stored in. 4045 4046 - CONFIG_SYS_MMC_ENV_PART (optional): 4047 4048 Specifies which MMC partition the environment is stored in. If not 4049 set, defaults to partition 0, the user area. Common values might be 4050 1 (first MMC boot partition), 2 (second MMC boot partition). 4051 4052 - CONFIG_ENV_OFFSET: 4053 - CONFIG_ENV_SIZE: 4054 4055 These two #defines specify the offset and size of the environment 4056 area within the specified MMC device. 4057 4058 If offset is positive (the usual case), it is treated as relative to 4059 the start of the MMC partition. If offset is negative, it is treated 4060 as relative to the end of the MMC partition. This can be useful if 4061 your board may be fitted with different MMC devices, which have 4062 different sizes for the MMC partitions, and you always want the 4063 environment placed at the very end of the partition, to leave the 4064 maximum possible space before it, to store other data. 4065 4066 These two values are in units of bytes, but must be aligned to an 4067 MMC sector boundary. 4068 4069 - CONFIG_ENV_OFFSET_REDUND (optional): 4070 4071 Specifies a second storage area, of CONFIG_ENV_SIZE size, used to 4072 hold a redundant copy of the environment data. This provides a 4073 valid backup copy in case the other copy is corrupted, e.g. due 4074 to a power failure during a "saveenv" operation. 4075 4076 This value may also be positive or negative; this is handled in the 4077 same way as CONFIG_ENV_OFFSET. 4078 4079 This value is also in units of bytes, but must also be aligned to 4080 an MMC sector boundary. 4081 4082 - CONFIG_ENV_SIZE_REDUND (optional): 4083 4084 This value need not be set, even when CONFIG_ENV_OFFSET_REDUND is 4085 set. If this value is set, it must be set to the same value as 4086 CONFIG_ENV_SIZE. 4087 4088- CONFIG_SYS_SPI_INIT_OFFSET 4089 4090 Defines offset to the initial SPI buffer area in DPRAM. The 4091 area is used at an early stage (ROM part) if the environment 4092 is configured to reside in the SPI EEPROM: We need a 520 byte 4093 scratch DPRAM area. It is used between the two initialization 4094 calls (spi_init_f() and spi_init_r()). A value of 0xB00 seems 4095 to be a good choice since it makes it far enough from the 4096 start of the data area as well as from the stack pointer. 4097 4098Please note that the environment is read-only until the monitor 4099has been relocated to RAM and a RAM copy of the environment has been 4100created; also, when using EEPROM you will have to use getenv_f() 4101until then to read environment variables. 4102 4103The environment is protected by a CRC32 checksum. Before the monitor 4104is relocated into RAM, as a result of a bad CRC you will be working 4105with the compiled-in default environment - *silently*!!! [This is 4106necessary, because the first environment variable we need is the 4107"baudrate" setting for the console - if we have a bad CRC, we don't 4108have any device yet where we could complain.] 4109 4110Note: once the monitor has been relocated, then it will complain if 4111the default environment is used; a new CRC is computed as soon as you 4112use the "saveenv" command to store a valid environment. 4113 4114- CONFIG_SYS_FAULT_ECHO_LINK_DOWN: 4115 Echo the inverted Ethernet link state to the fault LED. 4116 4117 Note: If this option is active, then CONFIG_SYS_FAULT_MII_ADDR 4118 also needs to be defined. 4119 4120- CONFIG_SYS_FAULT_MII_ADDR: 4121 MII address of the PHY to check for the Ethernet link state. 4122 4123- CONFIG_NS16550_MIN_FUNCTIONS: 4124 Define this if you desire to only have use of the NS16550_init 4125 and NS16550_putc functions for the serial driver located at 4126 drivers/serial/ns16550.c. This option is useful for saving 4127 space for already greatly restricted images, including but not 4128 limited to NAND_SPL configurations. 4129 4130- CONFIG_DISPLAY_BOARDINFO 4131 Display information about the board that U-Boot is running on 4132 when U-Boot starts up. The board function checkboard() is called 4133 to do this. 4134 4135- CONFIG_DISPLAY_BOARDINFO_LATE 4136 Similar to the previous option, but display this information 4137 later, once stdio is running and output goes to the LCD, if 4138 present. 4139 4140- CONFIG_BOARD_SIZE_LIMIT: 4141 Maximum size of the U-Boot image. When defined, the 4142 build system checks that the actual size does not 4143 exceed it. 4144 4145Low Level (hardware related) configuration options: 4146--------------------------------------------------- 4147 4148- CONFIG_SYS_CACHELINE_SIZE: 4149 Cache Line Size of the CPU. 4150 4151- CONFIG_SYS_DEFAULT_IMMR: 4152 Default address of the IMMR after system reset. 4153 4154 Needed on some 8260 systems (MPC8260ADS, PQ2FADS-ZU, 4155 and RPXsuper) to be able to adjust the position of 4156 the IMMR register after a reset. 4157 4158- CONFIG_SYS_CCSRBAR_DEFAULT: 4159 Default (power-on reset) physical address of CCSR on Freescale 4160 PowerPC SOCs. 4161 4162- CONFIG_SYS_CCSRBAR: 4163 Virtual address of CCSR. On a 32-bit build, this is typically 4164 the same value as CONFIG_SYS_CCSRBAR_DEFAULT. 4165 4166 CONFIG_SYS_DEFAULT_IMMR must also be set to this value, 4167 for cross-platform code that uses that macro instead. 4168 4169- CONFIG_SYS_CCSRBAR_PHYS: 4170 Physical address of CCSR. CCSR can be relocated to a new 4171 physical address, if desired. In this case, this macro should 4172 be set to that address. Otherwise, it should be set to the 4173 same value as CONFIG_SYS_CCSRBAR_DEFAULT. For example, CCSR 4174 is typically relocated on 36-bit builds. It is recommended 4175 that this macro be defined via the _HIGH and _LOW macros: 4176 4177 #define CONFIG_SYS_CCSRBAR_PHYS ((CONFIG_SYS_CCSRBAR_PHYS_HIGH 4178 * 1ull) << 32 | CONFIG_SYS_CCSRBAR_PHYS_LOW) 4179 4180- CONFIG_SYS_CCSRBAR_PHYS_HIGH: 4181 Bits 33-36 of CONFIG_SYS_CCSRBAR_PHYS. This value is typically 4182 either 0 (32-bit build) or 0xF (36-bit build). This macro is 4183 used in assembly code, so it must not contain typecasts or 4184 integer size suffixes (e.g. "ULL"). 4185 4186- CONFIG_SYS_CCSRBAR_PHYS_LOW: 4187 Lower 32-bits of CONFIG_SYS_CCSRBAR_PHYS. This macro is 4188 used in assembly code, so it must not contain typecasts or 4189 integer size suffixes (e.g. "ULL"). 4190 4191- CONFIG_SYS_CCSR_DO_NOT_RELOCATE: 4192 If this macro is defined, then CONFIG_SYS_CCSRBAR_PHYS will be 4193 forced to a value that ensures that CCSR is not relocated. 4194 4195- Floppy Disk Support: 4196 CONFIG_SYS_FDC_DRIVE_NUMBER 4197 4198 the default drive number (default value 0) 4199 4200 CONFIG_SYS_ISA_IO_STRIDE 4201 4202 defines the spacing between FDC chipset registers 4203 (default value 1) 4204 4205 CONFIG_SYS_ISA_IO_OFFSET 4206 4207 defines the offset of register from address. It 4208 depends on which part of the data bus is connected to 4209 the FDC chipset. (default value 0) 4210 4211 If CONFIG_SYS_ISA_IO_STRIDE CONFIG_SYS_ISA_IO_OFFSET and 4212 CONFIG_SYS_FDC_DRIVE_NUMBER are undefined, they take their 4213 default value. 4214 4215 if CONFIG_SYS_FDC_HW_INIT is defined, then the function 4216 fdc_hw_init() is called at the beginning of the FDC 4217 setup. fdc_hw_init() must be provided by the board 4218 source code. It is used to make hardware-dependent 4219 initializations. 4220 4221- CONFIG_IDE_AHB: 4222 Most IDE controllers were designed to be connected with PCI 4223 interface. Only few of them were designed for AHB interface. 4224 When software is doing ATA command and data transfer to 4225 IDE devices through IDE-AHB controller, some additional 4226 registers accessing to these kind of IDE-AHB controller 4227 is required. 4228 4229- CONFIG_SYS_IMMR: Physical address of the Internal Memory. 4230 DO NOT CHANGE unless you know exactly what you're 4231 doing! (11-4) [MPC8xx/82xx systems only] 4232 4233- CONFIG_SYS_INIT_RAM_ADDR: 4234 4235 Start address of memory area that can be used for 4236 initial data and stack; please note that this must be 4237 writable memory that is working WITHOUT special 4238 initialization, i. e. you CANNOT use normal RAM which 4239 will become available only after programming the 4240 memory controller and running certain initialization 4241 sequences. 4242 4243 U-Boot uses the following memory types: 4244 - MPC8xx and MPC8260: IMMR (internal memory of the CPU) 4245 - MPC824X: data cache 4246 - PPC4xx: data cache 4247 4248- CONFIG_SYS_GBL_DATA_OFFSET: 4249 4250 Offset of the initial data structure in the memory 4251 area defined by CONFIG_SYS_INIT_RAM_ADDR. Usually 4252 CONFIG_SYS_GBL_DATA_OFFSET is chosen such that the initial 4253 data is located at the end of the available space 4254 (sometimes written as (CONFIG_SYS_INIT_RAM_SIZE - 4255 GENERATED_GBL_DATA_SIZE), and the initial stack is just 4256 below that area (growing from (CONFIG_SYS_INIT_RAM_ADDR + 4257 CONFIG_SYS_GBL_DATA_OFFSET) downward. 4258 4259 Note: 4260 On the MPC824X (or other systems that use the data 4261 cache for initial memory) the address chosen for 4262 CONFIG_SYS_INIT_RAM_ADDR is basically arbitrary - it must 4263 point to an otherwise UNUSED address space between 4264 the top of RAM and the start of the PCI space. 4265 4266- CONFIG_SYS_SIUMCR: SIU Module Configuration (11-6) 4267 4268- CONFIG_SYS_SYPCR: System Protection Control (11-9) 4269 4270- CONFIG_SYS_TBSCR: Time Base Status and Control (11-26) 4271 4272- CONFIG_SYS_PISCR: Periodic Interrupt Status and Control (11-31) 4273 4274- CONFIG_SYS_PLPRCR: PLL, Low-Power, and Reset Control Register (15-30) 4275 4276- CONFIG_SYS_SCCR: System Clock and reset Control Register (15-27) 4277 4278- CONFIG_SYS_OR_TIMING_SDRAM: 4279 SDRAM timing 4280 4281- CONFIG_SYS_MAMR_PTA: 4282 periodic timer for refresh 4283 4284- CONFIG_SYS_DER: Debug Event Register (37-47) 4285 4286- FLASH_BASE0_PRELIM, FLASH_BASE1_PRELIM, CONFIG_SYS_REMAP_OR_AM, 4287 CONFIG_SYS_PRELIM_OR_AM, CONFIG_SYS_OR_TIMING_FLASH, CONFIG_SYS_OR0_REMAP, 4288 CONFIG_SYS_OR0_PRELIM, CONFIG_SYS_BR0_PRELIM, CONFIG_SYS_OR1_REMAP, CONFIG_SYS_OR1_PRELIM, 4289 CONFIG_SYS_BR1_PRELIM: 4290 Memory Controller Definitions: BR0/1 and OR0/1 (FLASH) 4291 4292- SDRAM_BASE2_PRELIM, SDRAM_BASE3_PRELIM, SDRAM_MAX_SIZE, 4293 CONFIG_SYS_OR_TIMING_SDRAM, CONFIG_SYS_OR2_PRELIM, CONFIG_SYS_BR2_PRELIM, 4294 CONFIG_SYS_OR3_PRELIM, CONFIG_SYS_BR3_PRELIM: 4295 Memory Controller Definitions: BR2/3 and OR2/3 (SDRAM) 4296 4297- CONFIG_SYS_MAMR_PTA, CONFIG_SYS_MPTPR_2BK_4K, CONFIG_SYS_MPTPR_1BK_4K, CONFIG_SYS_MPTPR_2BK_8K, 4298 CONFIG_SYS_MPTPR_1BK_8K, CONFIG_SYS_MAMR_8COL, CONFIG_SYS_MAMR_9COL: 4299 Machine Mode Register and Memory Periodic Timer 4300 Prescaler definitions (SDRAM timing) 4301 4302- CONFIG_SYS_I2C_UCODE_PATCH, CONFIG_SYS_I2C_DPMEM_OFFSET [0x1FC0]: 4303 enable I2C microcode relocation patch (MPC8xx); 4304 define relocation offset in DPRAM [DSP2] 4305 4306- CONFIG_SYS_SMC_UCODE_PATCH, CONFIG_SYS_SMC_DPMEM_OFFSET [0x1FC0]: 4307 enable SMC microcode relocation patch (MPC8xx); 4308 define relocation offset in DPRAM [SMC1] 4309 4310- CONFIG_SYS_SPI_UCODE_PATCH, CONFIG_SYS_SPI_DPMEM_OFFSET [0x1FC0]: 4311 enable SPI microcode relocation patch (MPC8xx); 4312 define relocation offset in DPRAM [SCC4] 4313 4314- CONFIG_SYS_CPM_POST_WORD_ADDR: (MPC8xx, MPC8260 only) 4315 Offset of the bootmode word in DPRAM used by post 4316 (Power On Self Tests). This definition overrides 4317 #define'd default value in commproc.h resp. 4318 cpm_8260.h. 4319 4320- CONFIG_SYS_PCI_SLV_MEM_LOCAL, CONFIG_SYS_PCI_SLV_MEM_BUS, CONFIG_SYS_PICMR0_MASK_ATTRIB, 4321 CONFIG_SYS_PCI_MSTR0_LOCAL, CONFIG_SYS_PCIMSK0_MASK, CONFIG_SYS_PCI_MSTR1_LOCAL, 4322 CONFIG_SYS_PCIMSK1_MASK, CONFIG_SYS_PCI_MSTR_MEM_LOCAL, CONFIG_SYS_PCI_MSTR_MEM_BUS, 4323 CONFIG_SYS_CPU_PCI_MEM_START, CONFIG_SYS_PCI_MSTR_MEM_SIZE, CONFIG_SYS_POCMR0_MASK_ATTRIB, 4324 CONFIG_SYS_PCI_MSTR_MEMIO_LOCAL, CONFIG_SYS_PCI_MSTR_MEMIO_BUS, CPU_PCI_MEMIO_START, 4325 CONFIG_SYS_PCI_MSTR_MEMIO_SIZE, CONFIG_SYS_POCMR1_MASK_ATTRIB, CONFIG_SYS_PCI_MSTR_IO_LOCAL, 4326 CONFIG_SYS_PCI_MSTR_IO_BUS, CONFIG_SYS_CPU_PCI_IO_START, CONFIG_SYS_PCI_MSTR_IO_SIZE, 4327 CONFIG_SYS_POCMR2_MASK_ATTRIB: (MPC826x only) 4328 Overrides the default PCI memory map in arch/powerpc/cpu/mpc8260/pci.c if set. 4329 4330- CONFIG_PCI_DISABLE_PCIE: 4331 Disable PCI-Express on systems where it is supported but not 4332 required. 4333 4334- CONFIG_PCI_ENUM_ONLY 4335 Only scan through and get the devices on the buses. 4336 Don't do any setup work, presumably because someone or 4337 something has already done it, and we don't need to do it 4338 a second time. Useful for platforms that are pre-booted 4339 by coreboot or similar. 4340 4341- CONFIG_PCI_INDIRECT_BRIDGE: 4342 Enable support for indirect PCI bridges. 4343 4344- CONFIG_SYS_SRIO: 4345 Chip has SRIO or not 4346 4347- CONFIG_SRIO1: 4348 Board has SRIO 1 port available 4349 4350- CONFIG_SRIO2: 4351 Board has SRIO 2 port available 4352 4353- CONFIG_SRIO_PCIE_BOOT_MASTER 4354 Board can support master function for Boot from SRIO and PCIE 4355 4356- CONFIG_SYS_SRIOn_MEM_VIRT: 4357 Virtual Address of SRIO port 'n' memory region 4358 4359- CONFIG_SYS_SRIOn_MEM_PHYS: 4360 Physical Address of SRIO port 'n' memory region 4361 4362- CONFIG_SYS_SRIOn_MEM_SIZE: 4363 Size of SRIO port 'n' memory region 4364 4365- CONFIG_SYS_NAND_BUSWIDTH_16BIT 4366 Defined to tell the NAND controller that the NAND chip is using 4367 a 16 bit bus. 4368 Not all NAND drivers use this symbol. 4369 Example of drivers that use it: 4370 - drivers/mtd/nand/ndfc.c 4371 - drivers/mtd/nand/mxc_nand.c 4372 4373- CONFIG_SYS_NDFC_EBC0_CFG 4374 Sets the EBC0_CFG register for the NDFC. If not defined 4375 a default value will be used. 4376 4377- CONFIG_SPD_EEPROM 4378 Get DDR timing information from an I2C EEPROM. Common 4379 with pluggable memory modules such as SODIMMs 4380 4381 SPD_EEPROM_ADDRESS 4382 I2C address of the SPD EEPROM 4383 4384- CONFIG_SYS_SPD_BUS_NUM 4385 If SPD EEPROM is on an I2C bus other than the first 4386 one, specify here. Note that the value must resolve 4387 to something your driver can deal with. 4388 4389- CONFIG_SYS_DDR_RAW_TIMING 4390 Get DDR timing information from other than SPD. Common with 4391 soldered DDR chips onboard without SPD. DDR raw timing 4392 parameters are extracted from datasheet and hard-coded into 4393 header files or board specific files. 4394 4395- CONFIG_FSL_DDR_INTERACTIVE 4396 Enable interactive DDR debugging. See doc/README.fsl-ddr. 4397 4398- CONFIG_FSL_DDR_SYNC_REFRESH 4399 Enable sync of refresh for multiple controllers. 4400 4401- CONFIG_FSL_DDR_BIST 4402 Enable built-in memory test for Freescale DDR controllers. 4403 4404- CONFIG_SYS_83XX_DDR_USES_CS0 4405 Only for 83xx systems. If specified, then DDR should 4406 be configured using CS0 and CS1 instead of CS2 and CS3. 4407 4408- CONFIG_ETHER_ON_FEC[12] 4409 Define to enable FEC[12] on a 8xx series processor. 4410 4411- CONFIG_FEC[12]_PHY 4412 Define to the hardcoded PHY address which corresponds 4413 to the given FEC; i. e. 4414 #define CONFIG_FEC1_PHY 4 4415 means that the PHY with address 4 is connected to FEC1 4416 4417 When set to -1, means to probe for first available. 4418 4419- CONFIG_FEC[12]_PHY_NORXERR 4420 The PHY does not have a RXERR line (RMII only). 4421 (so program the FEC to ignore it). 4422 4423- CONFIG_RMII 4424 Enable RMII mode for all FECs. 4425 Note that this is a global option, we can't 4426 have one FEC in standard MII mode and another in RMII mode. 4427 4428- CONFIG_CRC32_VERIFY 4429 Add a verify option to the crc32 command. 4430 The syntax is: 4431 4432 => crc32 -v <address> <count> <crc32> 4433 4434 Where address/count indicate a memory area 4435 and crc32 is the correct crc32 which the 4436 area should have. 4437 4438- CONFIG_LOOPW 4439 Add the "loopw" memory command. This only takes effect if 4440 the memory commands are activated globally (CONFIG_CMD_MEM). 4441 4442- CONFIG_MX_CYCLIC 4443 Add the "mdc" and "mwc" memory commands. These are cyclic 4444 "md/mw" commands. 4445 Examples: 4446 4447 => mdc.b 10 4 500 4448 This command will print 4 bytes (10,11,12,13) each 500 ms. 4449 4450 => mwc.l 100 12345678 10 4451 This command will write 12345678 to address 100 all 10 ms. 4452 4453 This only takes effect if the memory commands are activated 4454 globally (CONFIG_CMD_MEM). 4455 4456- CONFIG_SKIP_LOWLEVEL_INIT 4457 [ARM, NDS32, MIPS only] If this variable is defined, then certain 4458 low level initializations (like setting up the memory 4459 controller) are omitted and/or U-Boot does not 4460 relocate itself into RAM. 4461 4462 Normally this variable MUST NOT be defined. The only 4463 exception is when U-Boot is loaded (to RAM) by some 4464 other boot loader or by a debugger which performs 4465 these initializations itself. 4466 4467- CONFIG_SKIP_LOWLEVEL_INIT_ONLY 4468 [ARM926EJ-S only] This allows just the call to lowlevel_init() 4469 to be skipped. The normal CP15 init (such as enabling the 4470 instruction cache) is still performed. 4471 4472- CONFIG_SPL_BUILD 4473 Modifies the behaviour of start.S when compiling a loader 4474 that is executed before the actual U-Boot. E.g. when 4475 compiling a NAND SPL. 4476 4477- CONFIG_TPL_BUILD 4478 Modifies the behaviour of start.S when compiling a loader 4479 that is executed after the SPL and before the actual U-Boot. 4480 It is loaded by the SPL. 4481 4482- CONFIG_SYS_MPC85XX_NO_RESETVEC 4483 Only for 85xx systems. If this variable is specified, the section 4484 .resetvec is not kept and the section .bootpg is placed in the 4485 previous 4k of the .text section. 4486 4487- CONFIG_ARCH_MAP_SYSMEM 4488 Generally U-Boot (and in particular the md command) uses 4489 effective address. It is therefore not necessary to regard 4490 U-Boot address as virtual addresses that need to be translated 4491 to physical addresses. However, sandbox requires this, since 4492 it maintains its own little RAM buffer which contains all 4493 addressable memory. This option causes some memory accesses 4494 to be mapped through map_sysmem() / unmap_sysmem(). 4495 4496- CONFIG_X86_RESET_VECTOR 4497 If defined, the x86 reset vector code is included. This is not 4498 needed when U-Boot is running from Coreboot. 4499 4500- CONFIG_SPL_AM33XX_ENABLE_RTC32K_OSC: 4501 Enables the RTC32K OSC on AM33xx based plattforms 4502 4503- CONFIG_SYS_NAND_NO_SUBPAGE_WRITE 4504 Option to disable subpage write in NAND driver 4505 driver that uses this: 4506 drivers/mtd/nand/davinci_nand.c 4507 4508Freescale QE/FMAN Firmware Support: 4509----------------------------------- 4510 4511The Freescale QUICCEngine (QE) and Frame Manager (FMAN) both support the 4512loading of "firmware", which is encoded in the QE firmware binary format. 4513This firmware often needs to be loaded during U-Boot booting, so macros 4514are used to identify the storage device (NOR flash, SPI, etc) and the address 4515within that device. 4516 4517- CONFIG_SYS_FMAN_FW_ADDR 4518 The address in the storage device where the FMAN microcode is located. The 4519 meaning of this address depends on which CONFIG_SYS_QE_FW_IN_xxx macro 4520 is also specified. 4521 4522- CONFIG_SYS_QE_FW_ADDR 4523 The address in the storage device where the QE microcode is located. The 4524 meaning of this address depends on which CONFIG_SYS_QE_FW_IN_xxx macro 4525 is also specified. 4526 4527- CONFIG_SYS_QE_FMAN_FW_LENGTH 4528 The maximum possible size of the firmware. The firmware binary format 4529 has a field that specifies the actual size of the firmware, but it 4530 might not be possible to read any part of the firmware unless some 4531 local storage is allocated to hold the entire firmware first. 4532 4533- CONFIG_SYS_QE_FMAN_FW_IN_NOR 4534 Specifies that QE/FMAN firmware is located in NOR flash, mapped as 4535 normal addressable memory via the LBC. CONFIG_SYS_FMAN_FW_ADDR is the 4536 virtual address in NOR flash. 4537 4538- CONFIG_SYS_QE_FMAN_FW_IN_NAND 4539 Specifies that QE/FMAN firmware is located in NAND flash. 4540 CONFIG_SYS_FMAN_FW_ADDR is the offset within NAND flash. 4541 4542- CONFIG_SYS_QE_FMAN_FW_IN_MMC 4543 Specifies that QE/FMAN firmware is located on the primary SD/MMC 4544 device. CONFIG_SYS_FMAN_FW_ADDR is the byte offset on that device. 4545 4546- CONFIG_SYS_QE_FMAN_FW_IN_REMOTE 4547 Specifies that QE/FMAN firmware is located in the remote (master) 4548 memory space. CONFIG_SYS_FMAN_FW_ADDR is a virtual address which 4549 can be mapped from slave TLB->slave LAW->slave SRIO or PCIE outbound 4550 window->master inbound window->master LAW->the ucode address in 4551 master's memory space. 4552 4553Freescale Layerscape Management Complex Firmware Support: 4554--------------------------------------------------------- 4555The Freescale Layerscape Management Complex (MC) supports the loading of 4556"firmware". 4557This firmware often needs to be loaded during U-Boot booting, so macros 4558are used to identify the storage device (NOR flash, SPI, etc) and the address 4559within that device. 4560 4561- CONFIG_FSL_MC_ENET 4562 Enable the MC driver for Layerscape SoCs. 4563 4564Freescale Layerscape Debug Server Support: 4565------------------------------------------- 4566The Freescale Layerscape Debug Server Support supports the loading of 4567"Debug Server firmware" and triggering SP boot-rom. 4568This firmware often needs to be loaded during U-Boot booting. 4569 4570- CONFIG_SYS_MC_RSV_MEM_ALIGN 4571 Define alignment of reserved memory MC requires 4572 4573Reproducible builds 4574------------------- 4575 4576In order to achieve reproducible builds, timestamps used in the U-Boot build 4577process have to be set to a fixed value. 4578 4579This is done using the SOURCE_DATE_EPOCH environment variable. 4580SOURCE_DATE_EPOCH is to be set on the build host's shell, not as a configuration 4581option for U-Boot or an environment variable in U-Boot. 4582 4583SOURCE_DATE_EPOCH should be set to a number of seconds since the epoch, in UTC. 4584 4585Building the Software: 4586====================== 4587 4588Building U-Boot has been tested in several native build environments 4589and in many different cross environments. Of course we cannot support 4590all possibly existing versions of cross development tools in all 4591(potentially obsolete) versions. In case of tool chain problems we 4592recommend to use the ELDK (see http://www.denx.de/wiki/DULG/ELDK) 4593which is extensively used to build and test U-Boot. 4594 4595If you are not using a native environment, it is assumed that you 4596have GNU cross compiling tools available in your path. In this case, 4597you must set the environment variable CROSS_COMPILE in your shell. 4598Note that no changes to the Makefile or any other source files are 4599necessary. For example using the ELDK on a 4xx CPU, please enter: 4600 4601 $ CROSS_COMPILE=ppc_4xx- 4602 $ export CROSS_COMPILE 4603 4604Note: If you wish to generate Windows versions of the utilities in 4605 the tools directory you can use the MinGW toolchain 4606 (http://www.mingw.org). Set your HOST tools to the MinGW 4607 toolchain and execute 'make tools'. For example: 4608 4609 $ make HOSTCC=i586-mingw32msvc-gcc HOSTSTRIP=i586-mingw32msvc-strip tools 4610 4611 Binaries such as tools/mkimage.exe will be created which can 4612 be executed on computers running Windows. 4613 4614U-Boot is intended to be simple to build. After installing the 4615sources you must configure U-Boot for one specific board type. This 4616is done by typing: 4617 4618 make NAME_defconfig 4619 4620where "NAME_defconfig" is the name of one of the existing configu- 4621rations; see boards.cfg for supported names. 4622 4623Note: for some board special configuration names may exist; check if 4624 additional information is available from the board vendor; for 4625 instance, the TQM823L systems are available without (standard) 4626 or with LCD support. You can select such additional "features" 4627 when choosing the configuration, i. e. 4628 4629 make TQM823L_defconfig 4630 - will configure for a plain TQM823L, i. e. no LCD support 4631 4632 make TQM823L_LCD_defconfig 4633 - will configure for a TQM823L with U-Boot console on LCD 4634 4635 etc. 4636 4637 4638Finally, type "make all", and you should get some working U-Boot 4639images ready for download to / installation on your system: 4640 4641- "u-boot.bin" is a raw binary image 4642- "u-boot" is an image in ELF binary format 4643- "u-boot.srec" is in Motorola S-Record format 4644 4645By default the build is performed locally and the objects are saved 4646in the source directory. One of the two methods can be used to change 4647this behavior and build U-Boot to some external directory: 4648 46491. Add O= to the make command line invocations: 4650 4651 make O=/tmp/build distclean 4652 make O=/tmp/build NAME_defconfig 4653 make O=/tmp/build all 4654 46552. Set environment variable KBUILD_OUTPUT to point to the desired location: 4656 4657 export KBUILD_OUTPUT=/tmp/build 4658 make distclean 4659 make NAME_defconfig 4660 make all 4661 4662Note that the command line "O=" setting overrides the KBUILD_OUTPUT environment 4663variable. 4664 4665 4666Please be aware that the Makefiles assume you are using GNU make, so 4667for instance on NetBSD you might need to use "gmake" instead of 4668native "make". 4669 4670 4671If the system board that you have is not listed, then you will need 4672to port U-Boot to your hardware platform. To do this, follow these 4673steps: 4674 46751. Create a new directory to hold your board specific code. Add any 4676 files you need. In your board directory, you will need at least 4677 the "Makefile" and a "<board>.c". 46782. Create a new configuration file "include/configs/<board>.h" for 4679 your board. 46803. If you're porting U-Boot to a new CPU, then also create a new 4681 directory to hold your CPU specific code. Add any files you need. 46824. Run "make <board>_defconfig" with your new name. 46835. Type "make", and you should get a working "u-boot.srec" file 4684 to be installed on your target system. 46856. Debug and solve any problems that might arise. 4686 [Of course, this last step is much harder than it sounds.] 4687 4688 4689Testing of U-Boot Modifications, Ports to New Hardware, etc.: 4690============================================================== 4691 4692If you have modified U-Boot sources (for instance added a new board 4693or support for new devices, a new CPU, etc.) you are expected to 4694provide feedback to the other developers. The feedback normally takes 4695the form of a "patch", i. e. a context diff against a certain (latest 4696official or latest in the git repository) version of U-Boot sources. 4697 4698But before you submit such a patch, please verify that your modifi- 4699cation did not break existing code. At least make sure that *ALL* of 4700the supported boards compile WITHOUT ANY compiler warnings. To do so, 4701just run the buildman script (tools/buildman/buildman), which will 4702configure and build U-Boot for ALL supported system. Be warned, this 4703will take a while. Please see the buildman README, or run 'buildman -H' 4704for documentation. 4705 4706 4707See also "U-Boot Porting Guide" below. 4708 4709 4710Monitor Commands - Overview: 4711============================ 4712 4713go - start application at address 'addr' 4714run - run commands in an environment variable 4715bootm - boot application image from memory 4716bootp - boot image via network using BootP/TFTP protocol 4717bootz - boot zImage from memory 4718tftpboot- boot image via network using TFTP protocol 4719 and env variables "ipaddr" and "serverip" 4720 (and eventually "gatewayip") 4721tftpput - upload a file via network using TFTP protocol 4722rarpboot- boot image via network using RARP/TFTP protocol 4723diskboot- boot from IDE devicebootd - boot default, i.e., run 'bootcmd' 4724loads - load S-Record file over serial line 4725loadb - load binary file over serial line (kermit mode) 4726md - memory display 4727mm - memory modify (auto-incrementing) 4728nm - memory modify (constant address) 4729mw - memory write (fill) 4730cp - memory copy 4731cmp - memory compare 4732crc32 - checksum calculation 4733i2c - I2C sub-system 4734sspi - SPI utility commands 4735base - print or set address offset 4736printenv- print environment variables 4737setenv - set environment variables 4738saveenv - save environment variables to persistent storage 4739protect - enable or disable FLASH write protection 4740erase - erase FLASH memory 4741flinfo - print FLASH memory information 4742nand - NAND memory operations (see doc/README.nand) 4743bdinfo - print Board Info structure 4744iminfo - print header information for application image 4745coninfo - print console devices and informations 4746ide - IDE sub-system 4747loop - infinite loop on address range 4748loopw - infinite write loop on address range 4749mtest - simple RAM test 4750icache - enable or disable instruction cache 4751dcache - enable or disable data cache 4752reset - Perform RESET of the CPU 4753echo - echo args to console 4754version - print monitor version 4755help - print online help 4756? - alias for 'help' 4757 4758 4759Monitor Commands - Detailed Description: 4760======================================== 4761 4762TODO. 4763 4764For now: just type "help <command>". 4765 4766 4767Environment Variables: 4768====================== 4769 4770U-Boot supports user configuration using Environment Variables which 4771can be made persistent by saving to Flash memory. 4772 4773Environment Variables are set using "setenv", printed using 4774"printenv", and saved to Flash using "saveenv". Using "setenv" 4775without a value can be used to delete a variable from the 4776environment. As long as you don't save the environment you are 4777working with an in-memory copy. In case the Flash area containing the 4778environment is erased by accident, a default environment is provided. 4779 4780Some configuration options can be set using Environment Variables. 4781 4782List of environment variables (most likely not complete): 4783 4784 baudrate - see CONFIG_BAUDRATE 4785 4786 bootdelay - see CONFIG_BOOTDELAY 4787 4788 bootcmd - see CONFIG_BOOTCOMMAND 4789 4790 bootargs - Boot arguments when booting an RTOS image 4791 4792 bootfile - Name of the image to load with TFTP 4793 4794 bootm_low - Memory range available for image processing in the bootm 4795 command can be restricted. This variable is given as 4796 a hexadecimal number and defines lowest address allowed 4797 for use by the bootm command. See also "bootm_size" 4798 environment variable. Address defined by "bootm_low" is 4799 also the base of the initial memory mapping for the Linux 4800 kernel -- see the description of CONFIG_SYS_BOOTMAPSZ and 4801 bootm_mapsize. 4802 4803 bootm_mapsize - Size of the initial memory mapping for the Linux kernel. 4804 This variable is given as a hexadecimal number and it 4805 defines the size of the memory region starting at base 4806 address bootm_low that is accessible by the Linux kernel 4807 during early boot. If unset, CONFIG_SYS_BOOTMAPSZ is used 4808 as the default value if it is defined, and bootm_size is 4809 used otherwise. 4810 4811 bootm_size - Memory range available for image processing in the bootm 4812 command can be restricted. This variable is given as 4813 a hexadecimal number and defines the size of the region 4814 allowed for use by the bootm command. See also "bootm_low" 4815 environment variable. 4816 4817 updatefile - Location of the software update file on a TFTP server, used 4818 by the automatic software update feature. Please refer to 4819 documentation in doc/README.update for more details. 4820 4821 autoload - if set to "no" (any string beginning with 'n'), 4822 "bootp" will just load perform a lookup of the 4823 configuration from the BOOTP server, but not try to 4824 load any image using TFTP 4825 4826 autostart - if set to "yes", an image loaded using the "bootp", 4827 "rarpboot", "tftpboot" or "diskboot" commands will 4828 be automatically started (by internally calling 4829 "bootm") 4830 4831 If set to "no", a standalone image passed to the 4832 "bootm" command will be copied to the load address 4833 (and eventually uncompressed), but NOT be started. 4834 This can be used to load and uncompress arbitrary 4835 data. 4836 4837 fdt_high - if set this restricts the maximum address that the 4838 flattened device tree will be copied into upon boot. 4839 For example, if you have a system with 1 GB memory 4840 at physical address 0x10000000, while Linux kernel 4841 only recognizes the first 704 MB as low memory, you 4842 may need to set fdt_high as 0x3C000000 to have the 4843 device tree blob be copied to the maximum address 4844 of the 704 MB low memory, so that Linux kernel can 4845 access it during the boot procedure. 4846 4847 If this is set to the special value 0xFFFFFFFF then 4848 the fdt will not be copied at all on boot. For this 4849 to work it must reside in writable memory, have 4850 sufficient padding on the end of it for u-boot to 4851 add the information it needs into it, and the memory 4852 must be accessible by the kernel. 4853 4854 fdtcontroladdr- if set this is the address of the control flattened 4855 device tree used by U-Boot when CONFIG_OF_CONTROL is 4856 defined. 4857 4858 i2cfast - (PPC405GP|PPC405EP only) 4859 if set to 'y' configures Linux I2C driver for fast 4860 mode (400kHZ). This environment variable is used in 4861 initialization code. So, for changes to be effective 4862 it must be saved and board must be reset. 4863 4864 initrd_high - restrict positioning of initrd images: 4865 If this variable is not set, initrd images will be 4866 copied to the highest possible address in RAM; this 4867 is usually what you want since it allows for 4868 maximum initrd size. If for some reason you want to 4869 make sure that the initrd image is loaded below the 4870 CONFIG_SYS_BOOTMAPSZ limit, you can set this environment 4871 variable to a value of "no" or "off" or "0". 4872 Alternatively, you can set it to a maximum upper 4873 address to use (U-Boot will still check that it 4874 does not overwrite the U-Boot stack and data). 4875 4876 For instance, when you have a system with 16 MB 4877 RAM, and want to reserve 4 MB from use by Linux, 4878 you can do this by adding "mem=12M" to the value of 4879 the "bootargs" variable. However, now you must make 4880 sure that the initrd image is placed in the first 4881 12 MB as well - this can be done with 4882 4883 setenv initrd_high 00c00000 4884 4885 If you set initrd_high to 0xFFFFFFFF, this is an 4886 indication to U-Boot that all addresses are legal 4887 for the Linux kernel, including addresses in flash 4888 memory. In this case U-Boot will NOT COPY the 4889 ramdisk at all. This may be useful to reduce the 4890 boot time on your system, but requires that this 4891 feature is supported by your Linux kernel. 4892 4893 ipaddr - IP address; needed for tftpboot command 4894 4895 loadaddr - Default load address for commands like "bootp", 4896 "rarpboot", "tftpboot", "loadb" or "diskboot" 4897 4898 loads_echo - see CONFIG_LOADS_ECHO 4899 4900 serverip - TFTP server IP address; needed for tftpboot command 4901 4902 bootretry - see CONFIG_BOOT_RETRY_TIME 4903 4904 bootdelaykey - see CONFIG_AUTOBOOT_DELAY_STR 4905 4906 bootstopkey - see CONFIG_AUTOBOOT_STOP_STR 4907 4908 ethprime - controls which interface is used first. 4909 4910 ethact - controls which interface is currently active. 4911 For example you can do the following 4912 4913 => setenv ethact FEC 4914 => ping 192.168.0.1 # traffic sent on FEC 4915 => setenv ethact SCC 4916 => ping 10.0.0.1 # traffic sent on SCC 4917 4918 ethrotate - When set to "no" U-Boot does not go through all 4919 available network interfaces. 4920 It just stays at the currently selected interface. 4921 4922 netretry - When set to "no" each network operation will 4923 either succeed or fail without retrying. 4924 When set to "once" the network operation will 4925 fail when all the available network interfaces 4926 are tried once without success. 4927 Useful on scripts which control the retry operation 4928 themselves. 4929 4930 npe_ucode - set load address for the NPE microcode 4931 4932 silent_linux - If set then Linux will be told to boot silently, by 4933 changing the console to be empty. If "yes" it will be 4934 made silent. If "no" it will not be made silent. If 4935 unset, then it will be made silent if the U-Boot console 4936 is silent. 4937 4938 tftpsrcp - If this is set, the value is used for TFTP's 4939 UDP source port. 4940 4941 tftpdstp - If this is set, the value is used for TFTP's UDP 4942 destination port instead of the Well Know Port 69. 4943 4944 tftpblocksize - Block size to use for TFTP transfers; if not set, 4945 we use the TFTP server's default block size 4946 4947 tftptimeout - Retransmission timeout for TFTP packets (in milli- 4948 seconds, minimum value is 1000 = 1 second). Defines 4949 when a packet is considered to be lost so it has to 4950 be retransmitted. The default is 5000 = 5 seconds. 4951 Lowering this value may make downloads succeed 4952 faster in networks with high packet loss rates or 4953 with unreliable TFTP servers. 4954 4955 tftptimeoutcountmax - maximum count of TFTP timeouts (no 4956 unit, minimum value = 0). Defines how many timeouts 4957 can happen during a single file transfer before that 4958 transfer is aborted. The default is 10, and 0 means 4959 'no timeouts allowed'. Increasing this value may help 4960 downloads succeed with high packet loss rates, or with 4961 unreliable TFTP servers or client hardware. 4962 4963 vlan - When set to a value < 4095 the traffic over 4964 Ethernet is encapsulated/received over 802.1q 4965 VLAN tagged frames. 4966 4967 bootpretryperiod - Period during which BOOTP/DHCP sends retries. 4968 Unsigned value, in milliseconds. If not set, the period will 4969 be either the default (28000), or a value based on 4970 CONFIG_NET_RETRY_COUNT, if defined. This value has 4971 precedence over the valu based on CONFIG_NET_RETRY_COUNT. 4972 4973The following image location variables contain the location of images 4974used in booting. The "Image" column gives the role of the image and is 4975not an environment variable name. The other columns are environment 4976variable names. "File Name" gives the name of the file on a TFTP 4977server, "RAM Address" gives the location in RAM the image will be 4978loaded to, and "Flash Location" gives the image's address in NOR 4979flash or offset in NAND flash. 4980 4981*Note* - these variables don't have to be defined for all boards, some 4982boards currently use other variables for these purposes, and some 4983boards use these variables for other purposes. 4984 4985Image File Name RAM Address Flash Location 4986----- --------- ----------- -------------- 4987u-boot u-boot u-boot_addr_r u-boot_addr 4988Linux kernel bootfile kernel_addr_r kernel_addr 4989device tree blob fdtfile fdt_addr_r fdt_addr 4990ramdisk ramdiskfile ramdisk_addr_r ramdisk_addr 4991 4992The following environment variables may be used and automatically 4993updated by the network boot commands ("bootp" and "rarpboot"), 4994depending the information provided by your boot server: 4995 4996 bootfile - see above 4997 dnsip - IP address of your Domain Name Server 4998 dnsip2 - IP address of your secondary Domain Name Server 4999 gatewayip - IP address of the Gateway (Router) to use 5000 hostname - Target hostname 5001 ipaddr - see above 5002 netmask - Subnet Mask 5003 rootpath - Pathname of the root filesystem on the NFS server 5004 serverip - see above 5005 5006 5007There are two special Environment Variables: 5008 5009 serial# - contains hardware identification information such 5010 as type string and/or serial number 5011 ethaddr - Ethernet address 5012 5013These variables can be set only once (usually during manufacturing of 5014the board). U-Boot refuses to delete or overwrite these variables 5015once they have been set once. 5016 5017 5018Further special Environment Variables: 5019 5020 ver - Contains the U-Boot version string as printed 5021 with the "version" command. This variable is 5022 readonly (see CONFIG_VERSION_VARIABLE). 5023 5024 5025Please note that changes to some configuration parameters may take 5026only effect after the next boot (yes, that's just like Windoze :-). 5027 5028 5029Callback functions for environment variables: 5030--------------------------------------------- 5031 5032For some environment variables, the behavior of u-boot needs to change 5033when their values are changed. This functionality allows functions to 5034be associated with arbitrary variables. On creation, overwrite, or 5035deletion, the callback will provide the opportunity for some side 5036effect to happen or for the change to be rejected. 5037 5038The callbacks are named and associated with a function using the 5039U_BOOT_ENV_CALLBACK macro in your board or driver code. 5040 5041These callbacks are associated with variables in one of two ways. The 5042static list can be added to by defining CONFIG_ENV_CALLBACK_LIST_STATIC 5043in the board configuration to a string that defines a list of 5044associations. The list must be in the following format: 5045 5046 entry = variable_name[:callback_name] 5047 list = entry[,list] 5048 5049If the callback name is not specified, then the callback is deleted. 5050Spaces are also allowed anywhere in the list. 5051 5052Callbacks can also be associated by defining the ".callbacks" variable 5053with the same list format above. Any association in ".callbacks" will 5054override any association in the static list. You can define 5055CONFIG_ENV_CALLBACK_LIST_DEFAULT to a list (string) to define the 5056".callbacks" environment variable in the default or embedded environment. 5057 5058If CONFIG_REGEX is defined, the variable_name above is evaluated as a 5059regular expression. This allows multiple variables to be connected to 5060the same callback without explicitly listing them all out. 5061 5062 5063Command Line Parsing: 5064===================== 5065 5066There are two different command line parsers available with U-Boot: 5067the old "simple" one, and the much more powerful "hush" shell: 5068 5069Old, simple command line parser: 5070-------------------------------- 5071 5072- supports environment variables (through setenv / saveenv commands) 5073- several commands on one line, separated by ';' 5074- variable substitution using "... ${name} ..." syntax 5075- special characters ('$', ';') can be escaped by prefixing with '\', 5076 for example: 5077 setenv bootcmd bootm \${address} 5078- You can also escape text by enclosing in single apostrophes, for example: 5079 setenv addip 'setenv bootargs $bootargs ip=$ipaddr:$serverip:$gatewayip:$netmask:$hostname::off' 5080 5081Hush shell: 5082----------- 5083 5084- similar to Bourne shell, with control structures like 5085 if...then...else...fi, for...do...done; while...do...done, 5086 until...do...done, ... 5087- supports environment ("global") variables (through setenv / saveenv 5088 commands) and local shell variables (through standard shell syntax 5089 "name=value"); only environment variables can be used with "run" 5090 command 5091 5092General rules: 5093-------------- 5094 5095(1) If a command line (or an environment variable executed by a "run" 5096 command) contains several commands separated by semicolon, and 5097 one of these commands fails, then the remaining commands will be 5098 executed anyway. 5099 5100(2) If you execute several variables with one call to run (i. e. 5101 calling run with a list of variables as arguments), any failing 5102 command will cause "run" to terminate, i. e. the remaining 5103 variables are not executed. 5104 5105Note for Redundant Ethernet Interfaces: 5106======================================= 5107 5108Some boards come with redundant Ethernet interfaces; U-Boot supports 5109such configurations and is capable of automatic selection of a 5110"working" interface when needed. MAC assignment works as follows: 5111 5112Network interfaces are numbered eth0, eth1, eth2, ... Corresponding 5113MAC addresses can be stored in the environment as "ethaddr" (=>eth0), 5114"eth1addr" (=>eth1), "eth2addr", ... 5115 5116If the network interface stores some valid MAC address (for instance 5117in SROM), this is used as default address if there is NO correspon- 5118ding setting in the environment; if the corresponding environment 5119variable is set, this overrides the settings in the card; that means: 5120 5121o If the SROM has a valid MAC address, and there is no address in the 5122 environment, the SROM's address is used. 5123 5124o If there is no valid address in the SROM, and a definition in the 5125 environment exists, then the value from the environment variable is 5126 used. 5127 5128o If both the SROM and the environment contain a MAC address, and 5129 both addresses are the same, this MAC address is used. 5130 5131o If both the SROM and the environment contain a MAC address, and the 5132 addresses differ, the value from the environment is used and a 5133 warning is printed. 5134 5135o If neither SROM nor the environment contain a MAC address, an error 5136 is raised. If CONFIG_NET_RANDOM_ETHADDR is defined, then in this case 5137 a random, locally-assigned MAC is used. 5138 5139If Ethernet drivers implement the 'write_hwaddr' function, valid MAC addresses 5140will be programmed into hardware as part of the initialization process. This 5141may be skipped by setting the appropriate 'ethmacskip' environment variable. 5142The naming convention is as follows: 5143"ethmacskip" (=>eth0), "eth1macskip" (=>eth1) etc. 5144 5145Image Formats: 5146============== 5147 5148U-Boot is capable of booting (and performing other auxiliary operations on) 5149images in two formats: 5150 5151New uImage format (FIT) 5152----------------------- 5153 5154Flexible and powerful format based on Flattened Image Tree -- FIT (similar 5155to Flattened Device Tree). It allows the use of images with multiple 5156components (several kernels, ramdisks, etc.), with contents protected by 5157SHA1, MD5 or CRC32. More details are found in the doc/uImage.FIT directory. 5158 5159 5160Old uImage format 5161----------------- 5162 5163Old image format is based on binary files which can be basically anything, 5164preceded by a special header; see the definitions in include/image.h for 5165details; basically, the header defines the following image properties: 5166 5167* Target Operating System (Provisions for OpenBSD, NetBSD, FreeBSD, 5168 4.4BSD, Linux, SVR4, Esix, Solaris, Irix, SCO, Dell, NCR, VxWorks, 5169 LynxOS, pSOS, QNX, RTEMS, INTEGRITY; 5170 Currently supported: Linux, NetBSD, VxWorks, QNX, RTEMS, LynxOS, 5171 INTEGRITY). 5172* Target CPU Architecture (Provisions for Alpha, ARM, AVR32, Intel x86, 5173 IA64, MIPS, NDS32, Nios II, PowerPC, IBM S390, SuperH, Sparc, Sparc 64 Bit; 5174 Currently supported: ARM, AVR32, Intel x86, MIPS, NDS32, Nios II, PowerPC). 5175* Compression Type (uncompressed, gzip, bzip2) 5176* Load Address 5177* Entry Point 5178* Image Name 5179* Image Timestamp 5180 5181The header is marked by a special Magic Number, and both the header 5182and the data portions of the image are secured against corruption by 5183CRC32 checksums. 5184 5185 5186Linux Support: 5187============== 5188 5189Although U-Boot should support any OS or standalone application 5190easily, the main focus has always been on Linux during the design of 5191U-Boot. 5192 5193U-Boot includes many features that so far have been part of some 5194special "boot loader" code within the Linux kernel. Also, any 5195"initrd" images to be used are no longer part of one big Linux image; 5196instead, kernel and "initrd" are separate images. This implementation 5197serves several purposes: 5198 5199- the same features can be used for other OS or standalone 5200 applications (for instance: using compressed images to reduce the 5201 Flash memory footprint) 5202 5203- it becomes much easier to port new Linux kernel versions because 5204 lots of low-level, hardware dependent stuff are done by U-Boot 5205 5206- the same Linux kernel image can now be used with different "initrd" 5207 images; of course this also means that different kernel images can 5208 be run with the same "initrd". This makes testing easier (you don't 5209 have to build a new "zImage.initrd" Linux image when you just 5210 change a file in your "initrd"). Also, a field-upgrade of the 5211 software is easier now. 5212 5213 5214Linux HOWTO: 5215============ 5216 5217Porting Linux to U-Boot based systems: 5218--------------------------------------- 5219 5220U-Boot cannot save you from doing all the necessary modifications to 5221configure the Linux device drivers for use with your target hardware 5222(no, we don't intend to provide a full virtual machine interface to 5223Linux :-). 5224 5225But now you can ignore ALL boot loader code (in arch/powerpc/mbxboot). 5226 5227Just make sure your machine specific header file (for instance 5228include/asm-ppc/tqm8xx.h) includes the same definition of the Board 5229Information structure as we define in include/asm-<arch>/u-boot.h, 5230and make sure that your definition of IMAP_ADDR uses the same value 5231as your U-Boot configuration in CONFIG_SYS_IMMR. 5232 5233Note that U-Boot now has a driver model, a unified model for drivers. 5234If you are adding a new driver, plumb it into driver model. If there 5235is no uclass available, you are encouraged to create one. See 5236doc/driver-model. 5237 5238 5239Configuring the Linux kernel: 5240----------------------------- 5241 5242No specific requirements for U-Boot. Make sure you have some root 5243device (initial ramdisk, NFS) for your target system. 5244 5245 5246Building a Linux Image: 5247----------------------- 5248 5249With U-Boot, "normal" build targets like "zImage" or "bzImage" are 5250not used. If you use recent kernel source, a new build target 5251"uImage" will exist which automatically builds an image usable by 5252U-Boot. Most older kernels also have support for a "pImage" target, 5253which was introduced for our predecessor project PPCBoot and uses a 5254100% compatible format. 5255 5256Example: 5257 5258 make TQM850L_defconfig 5259 make oldconfig 5260 make dep 5261 make uImage 5262 5263The "uImage" build target uses a special tool (in 'tools/mkimage') to 5264encapsulate a compressed Linux kernel image with header information, 5265CRC32 checksum etc. for use with U-Boot. This is what we are doing: 5266 5267* build a standard "vmlinux" kernel image (in ELF binary format): 5268 5269* convert the kernel into a raw binary image: 5270 5271 ${CROSS_COMPILE}-objcopy -O binary \ 5272 -R .note -R .comment \ 5273 -S vmlinux linux.bin 5274 5275* compress the binary image: 5276 5277 gzip -9 linux.bin 5278 5279* package compressed binary image for U-Boot: 5280 5281 mkimage -A ppc -O linux -T kernel -C gzip \ 5282 -a 0 -e 0 -n "Linux Kernel Image" \ 5283 -d linux.bin.gz uImage 5284 5285 5286The "mkimage" tool can also be used to create ramdisk images for use 5287with U-Boot, either separated from the Linux kernel image, or 5288combined into one file. "mkimage" encapsulates the images with a 64 5289byte header containing information about target architecture, 5290operating system, image type, compression method, entry points, time 5291stamp, CRC32 checksums, etc. 5292 5293"mkimage" can be called in two ways: to verify existing images and 5294print the header information, or to build new images. 5295 5296In the first form (with "-l" option) mkimage lists the information 5297contained in the header of an existing U-Boot image; this includes 5298checksum verification: 5299 5300 tools/mkimage -l image 5301 -l ==> list image header information 5302 5303The second form (with "-d" option) is used to build a U-Boot image 5304from a "data file" which is used as image payload: 5305 5306 tools/mkimage -A arch -O os -T type -C comp -a addr -e ep \ 5307 -n name -d data_file image 5308 -A ==> set architecture to 'arch' 5309 -O ==> set operating system to 'os' 5310 -T ==> set image type to 'type' 5311 -C ==> set compression type 'comp' 5312 -a ==> set load address to 'addr' (hex) 5313 -e ==> set entry point to 'ep' (hex) 5314 -n ==> set image name to 'name' 5315 -d ==> use image data from 'datafile' 5316 5317Right now, all Linux kernels for PowerPC systems use the same load 5318address (0x00000000), but the entry point address depends on the 5319kernel version: 5320 5321- 2.2.x kernels have the entry point at 0x0000000C, 5322- 2.3.x and later kernels have the entry point at 0x00000000. 5323 5324So a typical call to build a U-Boot image would read: 5325 5326 -> tools/mkimage -n '2.4.4 kernel for TQM850L' \ 5327 > -A ppc -O linux -T kernel -C gzip -a 0 -e 0 \ 5328 > -d /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/powerpc/coffboot/vmlinux.gz \ 5329 > examples/uImage.TQM850L 5330 Image Name: 2.4.4 kernel for TQM850L 5331 Created: Wed Jul 19 02:34:59 2000 5332 Image Type: PowerPC Linux Kernel Image (gzip compressed) 5333 Data Size: 335725 Bytes = 327.86 kB = 0.32 MB 5334 Load Address: 0x00000000 5335 Entry Point: 0x00000000 5336 5337To verify the contents of the image (or check for corruption): 5338 5339 -> tools/mkimage -l examples/uImage.TQM850L 5340 Image Name: 2.4.4 kernel for TQM850L 5341 Created: Wed Jul 19 02:34:59 2000 5342 Image Type: PowerPC Linux Kernel Image (gzip compressed) 5343 Data Size: 335725 Bytes = 327.86 kB = 0.32 MB 5344 Load Address: 0x00000000 5345 Entry Point: 0x00000000 5346 5347NOTE: for embedded systems where boot time is critical you can trade 5348speed for memory and install an UNCOMPRESSED image instead: this 5349needs more space in Flash, but boots much faster since it does not 5350need to be uncompressed: 5351 5352 -> gunzip /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/powerpc/coffboot/vmlinux.gz 5353 -> tools/mkimage -n '2.4.4 kernel for TQM850L' \ 5354 > -A ppc -O linux -T kernel -C none -a 0 -e 0 \ 5355 > -d /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/powerpc/coffboot/vmlinux \ 5356 > examples/uImage.TQM850L-uncompressed 5357 Image Name: 2.4.4 kernel for TQM850L 5358 Created: Wed Jul 19 02:34:59 2000 5359 Image Type: PowerPC Linux Kernel Image (uncompressed) 5360 Data Size: 792160 Bytes = 773.59 kB = 0.76 MB 5361 Load Address: 0x00000000 5362 Entry Point: 0x00000000 5363 5364 5365Similar you can build U-Boot images from a 'ramdisk.image.gz' file 5366when your kernel is intended to use an initial ramdisk: 5367 5368 -> tools/mkimage -n 'Simple Ramdisk Image' \ 5369 > -A ppc -O linux -T ramdisk -C gzip \ 5370 > -d /LinuxPPC/images/SIMPLE-ramdisk.image.gz examples/simple-initrd 5371 Image Name: Simple Ramdisk Image 5372 Created: Wed Jan 12 14:01:50 2000 5373 Image Type: PowerPC Linux RAMDisk Image (gzip compressed) 5374 Data Size: 566530 Bytes = 553.25 kB = 0.54 MB 5375 Load Address: 0x00000000 5376 Entry Point: 0x00000000 5377 5378The "dumpimage" is a tool to disassemble images built by mkimage. Its "-i" 5379option performs the converse operation of the mkimage's second form (the "-d" 5380option). Given an image built by mkimage, the dumpimage extracts a "data file" 5381from the image: 5382 5383 tools/dumpimage -i image -T type -p position data_file 5384 -i ==> extract from the 'image' a specific 'data_file' 5385 -T ==> set image type to 'type' 5386 -p ==> 'position' (starting at 0) of the 'data_file' inside the 'image' 5387 5388 5389Installing a Linux Image: 5390------------------------- 5391 5392To downloading a U-Boot image over the serial (console) interface, 5393you must convert the image to S-Record format: 5394 5395 objcopy -I binary -O srec examples/image examples/image.srec 5396 5397The 'objcopy' does not understand the information in the U-Boot 5398image header, so the resulting S-Record file will be relative to 5399address 0x00000000. To load it to a given address, you need to 5400specify the target address as 'offset' parameter with the 'loads' 5401command. 5402 5403Example: install the image to address 0x40100000 (which on the 5404TQM8xxL is in the first Flash bank): 5405 5406 => erase 40100000 401FFFFF 5407 5408 .......... done 5409 Erased 8 sectors 5410 5411 => loads 40100000 5412 ## Ready for S-Record download ... 5413 ~>examples/image.srec 5414 1 2 3 4 5 6 7 8 9 10 11 12 13 ... 5415 ... 5416 15989 15990 15991 15992 5417 [file transfer complete] 5418 [connected] 5419 ## Start Addr = 0x00000000 5420 5421 5422You can check the success of the download using the 'iminfo' command; 5423this includes a checksum verification so you can be sure no data 5424corruption happened: 5425 5426 => imi 40100000 5427 5428 ## Checking Image at 40100000 ... 5429 Image Name: 2.2.13 for initrd on TQM850L 5430 Image Type: PowerPC Linux Kernel Image (gzip compressed) 5431 Data Size: 335725 Bytes = 327 kB = 0 MB 5432 Load Address: 00000000 5433 Entry Point: 0000000c 5434 Verifying Checksum ... OK 5435 5436 5437Boot Linux: 5438----------- 5439 5440The "bootm" command is used to boot an application that is stored in 5441memory (RAM or Flash). In case of a Linux kernel image, the contents 5442of the "bootargs" environment variable is passed to the kernel as 5443parameters. You can check and modify this variable using the 5444"printenv" and "setenv" commands: 5445 5446 5447 => printenv bootargs 5448 bootargs=root=/dev/ram 5449 5450 => setenv bootargs root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2 5451 5452 => printenv bootargs 5453 bootargs=root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2 5454 5455 => bootm 40020000 5456 ## Booting Linux kernel at 40020000 ... 5457 Image Name: 2.2.13 for NFS on TQM850L 5458 Image Type: PowerPC Linux Kernel Image (gzip compressed) 5459 Data Size: 381681 Bytes = 372 kB = 0 MB 5460 Load Address: 00000000 5461 Entry Point: 0000000c 5462 Verifying Checksum ... OK 5463 Uncompressing Kernel Image ... OK 5464 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 5465 Boot arguments: root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2 5466 time_init: decrementer frequency = 187500000/60 5467 Calibrating delay loop... 49.77 BogoMIPS 5468 Memory: 15208k available (700k kernel code, 444k data, 32k init) [c0000000,c1000000] 5469 ... 5470 5471If you want to boot a Linux kernel with initial RAM disk, you pass 5472the memory addresses of both the kernel and the initrd image (PPBCOOT 5473format!) to the "bootm" command: 5474 5475 => imi 40100000 40200000 5476 5477 ## Checking Image at 40100000 ... 5478 Image Name: 2.2.13 for initrd on TQM850L 5479 Image Type: PowerPC Linux Kernel Image (gzip compressed) 5480 Data Size: 335725 Bytes = 327 kB = 0 MB 5481 Load Address: 00000000 5482 Entry Point: 0000000c 5483 Verifying Checksum ... OK 5484 5485 ## Checking Image at 40200000 ... 5486 Image Name: Simple Ramdisk Image 5487 Image Type: PowerPC Linux RAMDisk Image (gzip compressed) 5488 Data Size: 566530 Bytes = 553 kB = 0 MB 5489 Load Address: 00000000 5490 Entry Point: 00000000 5491 Verifying Checksum ... OK 5492 5493 => bootm 40100000 40200000 5494 ## Booting Linux kernel at 40100000 ... 5495 Image Name: 2.2.13 for initrd on TQM850L 5496 Image Type: PowerPC Linux Kernel Image (gzip compressed) 5497 Data Size: 335725 Bytes = 327 kB = 0 MB 5498 Load Address: 00000000 5499 Entry Point: 0000000c 5500 Verifying Checksum ... OK 5501 Uncompressing Kernel Image ... OK 5502 ## Loading RAMDisk Image at 40200000 ... 5503 Image Name: Simple Ramdisk Image 5504 Image Type: PowerPC Linux RAMDisk Image (gzip compressed) 5505 Data Size: 566530 Bytes = 553 kB = 0 MB 5506 Load Address: 00000000 5507 Entry Point: 00000000 5508 Verifying Checksum ... OK 5509 Loading Ramdisk ... OK 5510 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 5511 Boot arguments: root=/dev/ram 5512 time_init: decrementer frequency = 187500000/60 5513 Calibrating delay loop... 49.77 BogoMIPS 5514 ... 5515 RAMDISK: Compressed image found at block 0 5516 VFS: Mounted root (ext2 filesystem). 5517 5518 bash# 5519 5520Boot Linux and pass a flat device tree: 5521----------- 5522 5523First, U-Boot must be compiled with the appropriate defines. See the section 5524titled "Linux Kernel Interface" above for a more in depth explanation. The 5525following is an example of how to start a kernel and pass an updated 5526flat device tree: 5527 5528=> print oftaddr 5529oftaddr=0x300000 5530=> print oft 5531oft=oftrees/mpc8540ads.dtb 5532=> tftp $oftaddr $oft 5533Speed: 1000, full duplex 5534Using TSEC0 device 5535TFTP from server 192.168.1.1; our IP address is 192.168.1.101 5536Filename 'oftrees/mpc8540ads.dtb'. 5537Load address: 0x300000 5538Loading: # 5539done 5540Bytes transferred = 4106 (100a hex) 5541=> tftp $loadaddr $bootfile 5542Speed: 1000, full duplex 5543Using TSEC0 device 5544TFTP from server 192.168.1.1; our IP address is 192.168.1.2 5545Filename 'uImage'. 5546Load address: 0x200000 5547Loading:############ 5548done 5549Bytes transferred = 1029407 (fb51f hex) 5550=> print loadaddr 5551loadaddr=200000 5552=> print oftaddr 5553oftaddr=0x300000 5554=> bootm $loadaddr - $oftaddr 5555## Booting image at 00200000 ... 5556 Image Name: Linux-2.6.17-dirty 5557 Image Type: PowerPC Linux Kernel Image (gzip compressed) 5558 Data Size: 1029343 Bytes = 1005.2 kB 5559 Load Address: 00000000 5560 Entry Point: 00000000 5561 Verifying Checksum ... OK 5562 Uncompressing Kernel Image ... OK 5563Booting using flat device tree at 0x300000 5564Using MPC85xx ADS machine description 5565Memory CAM mapping: CAM0=256Mb, CAM1=256Mb, CAM2=0Mb residual: 0Mb 5566[snip] 5567 5568 5569More About U-Boot Image Types: 5570------------------------------ 5571 5572U-Boot supports the following image types: 5573 5574 "Standalone Programs" are directly runnable in the environment 5575 provided by U-Boot; it is expected that (if they behave 5576 well) you can continue to work in U-Boot after return from 5577 the Standalone Program. 5578 "OS Kernel Images" are usually images of some Embedded OS which 5579 will take over control completely. Usually these programs 5580 will install their own set of exception handlers, device 5581 drivers, set up the MMU, etc. - this means, that you cannot 5582 expect to re-enter U-Boot except by resetting the CPU. 5583 "RAMDisk Images" are more or less just data blocks, and their 5584 parameters (address, size) are passed to an OS kernel that is 5585 being started. 5586 "Multi-File Images" contain several images, typically an OS 5587 (Linux) kernel image and one or more data images like 5588 RAMDisks. This construct is useful for instance when you want 5589 to boot over the network using BOOTP etc., where the boot 5590 server provides just a single image file, but you want to get 5591 for instance an OS kernel and a RAMDisk image. 5592 5593 "Multi-File Images" start with a list of image sizes, each 5594 image size (in bytes) specified by an "uint32_t" in network 5595 byte order. This list is terminated by an "(uint32_t)0". 5596 Immediately after the terminating 0 follow the images, one by 5597 one, all aligned on "uint32_t" boundaries (size rounded up to 5598 a multiple of 4 bytes). 5599 5600 "Firmware Images" are binary images containing firmware (like 5601 U-Boot or FPGA images) which usually will be programmed to 5602 flash memory. 5603 5604 "Script files" are command sequences that will be executed by 5605 U-Boot's command interpreter; this feature is especially 5606 useful when you configure U-Boot to use a real shell (hush) 5607 as command interpreter. 5608 5609Booting the Linux zImage: 5610------------------------- 5611 5612On some platforms, it's possible to boot Linux zImage. This is done 5613using the "bootz" command. The syntax of "bootz" command is the same 5614as the syntax of "bootm" command. 5615 5616Note, defining the CONFIG_SUPPORT_RAW_INITRD allows user to supply 5617kernel with raw initrd images. The syntax is slightly different, the 5618address of the initrd must be augmented by it's size, in the following 5619format: "<initrd addres>:<initrd size>". 5620 5621 5622Standalone HOWTO: 5623================= 5624 5625One of the features of U-Boot is that you can dynamically load and 5626run "standalone" applications, which can use some resources of 5627U-Boot like console I/O functions or interrupt services. 5628 5629Two simple examples are included with the sources: 5630 5631"Hello World" Demo: 5632------------------- 5633 5634'examples/hello_world.c' contains a small "Hello World" Demo 5635application; it is automatically compiled when you build U-Boot. 5636It's configured to run at address 0x00040004, so you can play with it 5637like that: 5638 5639 => loads 5640 ## Ready for S-Record download ... 5641 ~>examples/hello_world.srec 5642 1 2 3 4 5 6 7 8 9 10 11 ... 5643 [file transfer complete] 5644 [connected] 5645 ## Start Addr = 0x00040004 5646 5647 => go 40004 Hello World! This is a test. 5648 ## Starting application at 0x00040004 ... 5649 Hello World 5650 argc = 7 5651 argv[0] = "40004" 5652 argv[1] = "Hello" 5653 argv[2] = "World!" 5654 argv[3] = "This" 5655 argv[4] = "is" 5656 argv[5] = "a" 5657 argv[6] = "test." 5658 argv[7] = "<NULL>" 5659 Hit any key to exit ... 5660 5661 ## Application terminated, rc = 0x0 5662 5663Another example, which demonstrates how to register a CPM interrupt 5664handler with the U-Boot code, can be found in 'examples/timer.c'. 5665Here, a CPM timer is set up to generate an interrupt every second. 5666The interrupt service routine is trivial, just printing a '.' 5667character, but this is just a demo program. The application can be 5668controlled by the following keys: 5669 5670 ? - print current values og the CPM Timer registers 5671 b - enable interrupts and start timer 5672 e - stop timer and disable interrupts 5673 q - quit application 5674 5675 => loads 5676 ## Ready for S-Record download ... 5677 ~>examples/timer.srec 5678 1 2 3 4 5 6 7 8 9 10 11 ... 5679 [file transfer complete] 5680 [connected] 5681 ## Start Addr = 0x00040004 5682 5683 => go 40004 5684 ## Starting application at 0x00040004 ... 5685 TIMERS=0xfff00980 5686 Using timer 1 5687 tgcr @ 0xfff00980, tmr @ 0xfff00990, trr @ 0xfff00994, tcr @ 0xfff00998, tcn @ 0xfff0099c, ter @ 0xfff009b0 5688 5689Hit 'b': 5690 [q, b, e, ?] Set interval 1000000 us 5691 Enabling timer 5692Hit '?': 5693 [q, b, e, ?] ........ 5694 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0xef6, ter=0x0 5695Hit '?': 5696 [q, b, e, ?] . 5697 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x2ad4, ter=0x0 5698Hit '?': 5699 [q, b, e, ?] . 5700 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x1efc, ter=0x0 5701Hit '?': 5702 [q, b, e, ?] . 5703 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x169d, ter=0x0 5704Hit 'e': 5705 [q, b, e, ?] ...Stopping timer 5706Hit 'q': 5707 [q, b, e, ?] ## Application terminated, rc = 0x0 5708 5709 5710Minicom warning: 5711================ 5712 5713Over time, many people have reported problems when trying to use the 5714"minicom" terminal emulation program for serial download. I (wd) 5715consider minicom to be broken, and recommend not to use it. Under 5716Unix, I recommend to use C-Kermit for general purpose use (and 5717especially for kermit binary protocol download ("loadb" command), and 5718use "cu" for S-Record download ("loads" command). See 5719http://www.denx.de/wiki/view/DULG/SystemSetup#Section_4.3. 5720for help with kermit. 5721 5722 5723Nevertheless, if you absolutely want to use it try adding this 5724configuration to your "File transfer protocols" section: 5725 5726 Name Program Name U/D FullScr IO-Red. Multi 5727 X kermit /usr/bin/kermit -i -l %l -s Y U Y N N 5728 Y kermit /usr/bin/kermit -i -l %l -r N D Y N N 5729 5730 5731NetBSD Notes: 5732============= 5733 5734Starting at version 0.9.2, U-Boot supports NetBSD both as host 5735(build U-Boot) and target system (boots NetBSD/mpc8xx). 5736 5737Building requires a cross environment; it is known to work on 5738NetBSD/i386 with the cross-powerpc-netbsd-1.3 package (you will also 5739need gmake since the Makefiles are not compatible with BSD make). 5740Note that the cross-powerpc package does not install include files; 5741attempting to build U-Boot will fail because <machine/ansi.h> is 5742missing. This file has to be installed and patched manually: 5743 5744 # cd /usr/pkg/cross/powerpc-netbsd/include 5745 # mkdir powerpc 5746 # ln -s powerpc machine 5747 # cp /usr/src/sys/arch/powerpc/include/ansi.h powerpc/ansi.h 5748 # ${EDIT} powerpc/ansi.h ## must remove __va_list, _BSD_VA_LIST 5749 5750Native builds *don't* work due to incompatibilities between native 5751and U-Boot include files. 5752 5753Booting assumes that (the first part of) the image booted is a 5754stage-2 loader which in turn loads and then invokes the kernel 5755proper. Loader sources will eventually appear in the NetBSD source 5756tree (probably in sys/arc/mpc8xx/stand/u-boot_stage2/); in the 5757meantime, see ftp://ftp.denx.de/pub/u-boot/ppcboot_stage2.tar.gz 5758 5759 5760Implementation Internals: 5761========================= 5762 5763The following is not intended to be a complete description of every 5764implementation detail. However, it should help to understand the 5765inner workings of U-Boot and make it easier to port it to custom 5766hardware. 5767 5768 5769Initial Stack, Global Data: 5770--------------------------- 5771 5772The implementation of U-Boot is complicated by the fact that U-Boot 5773starts running out of ROM (flash memory), usually without access to 5774system RAM (because the memory controller is not initialized yet). 5775This means that we don't have writable Data or BSS segments, and BSS 5776is not initialized as zero. To be able to get a C environment working 5777at all, we have to allocate at least a minimal stack. Implementation 5778options for this are defined and restricted by the CPU used: Some CPU 5779models provide on-chip memory (like the IMMR area on MPC8xx and 5780MPC826x processors), on others (parts of) the data cache can be 5781locked as (mis-) used as memory, etc. 5782 5783 Chris Hallinan posted a good summary of these issues to the 5784 U-Boot mailing list: 5785 5786 Subject: RE: [U-Boot-Users] RE: More On Memory Bank x (nothingness)? 5787 From: "Chris Hallinan" <clh@net1plus.com> 5788 Date: Mon, 10 Feb 2003 16:43:46 -0500 (22:43 MET) 5789 ... 5790 5791 Correct me if I'm wrong, folks, but the way I understand it 5792 is this: Using DCACHE as initial RAM for Stack, etc, does not 5793 require any physical RAM backing up the cache. The cleverness 5794 is that the cache is being used as a temporary supply of 5795 necessary storage before the SDRAM controller is setup. It's 5796 beyond the scope of this list to explain the details, but you 5797 can see how this works by studying the cache architecture and 5798 operation in the architecture and processor-specific manuals. 5799 5800 OCM is On Chip Memory, which I believe the 405GP has 4K. It 5801 is another option for the system designer to use as an 5802 initial stack/RAM area prior to SDRAM being available. Either 5803 option should work for you. Using CS 4 should be fine if your 5804 board designers haven't used it for something that would 5805 cause you grief during the initial boot! It is frequently not 5806 used. 5807 5808 CONFIG_SYS_INIT_RAM_ADDR should be somewhere that won't interfere 5809 with your processor/board/system design. The default value 5810 you will find in any recent u-boot distribution in 5811 walnut.h should work for you. I'd set it to a value larger 5812 than your SDRAM module. If you have a 64MB SDRAM module, set 5813 it above 400_0000. Just make sure your board has no resources 5814 that are supposed to respond to that address! That code in 5815 start.S has been around a while and should work as is when 5816 you get the config right. 5817 5818 -Chris Hallinan 5819 DS4.COM, Inc. 5820 5821It is essential to remember this, since it has some impact on the C 5822code for the initialization procedures: 5823 5824* Initialized global data (data segment) is read-only. Do not attempt 5825 to write it. 5826 5827* Do not use any uninitialized global data (or implicitly initialized 5828 as zero data - BSS segment) at all - this is undefined, initiali- 5829 zation is performed later (when relocating to RAM). 5830 5831* Stack space is very limited. Avoid big data buffers or things like 5832 that. 5833 5834Having only the stack as writable memory limits means we cannot use 5835normal global data to share information between the code. But it 5836turned out that the implementation of U-Boot can be greatly 5837simplified by making a global data structure (gd_t) available to all 5838functions. We could pass a pointer to this data as argument to _all_ 5839functions, but this would bloat the code. Instead we use a feature of 5840the GCC compiler (Global Register Variables) to share the data: we 5841place a pointer (gd) to the global data into a register which we 5842reserve for this purpose. 5843 5844When choosing a register for such a purpose we are restricted by the 5845relevant (E)ABI specifications for the current architecture, and by 5846GCC's implementation. 5847 5848For PowerPC, the following registers have specific use: 5849 R1: stack pointer 5850 R2: reserved for system use 5851 R3-R4: parameter passing and return values 5852 R5-R10: parameter passing 5853 R13: small data area pointer 5854 R30: GOT pointer 5855 R31: frame pointer 5856 5857 (U-Boot also uses R12 as internal GOT pointer. r12 5858 is a volatile register so r12 needs to be reset when 5859 going back and forth between asm and C) 5860 5861 ==> U-Boot will use R2 to hold a pointer to the global data 5862 5863 Note: on PPC, we could use a static initializer (since the 5864 address of the global data structure is known at compile time), 5865 but it turned out that reserving a register results in somewhat 5866 smaller code - although the code savings are not that big (on 5867 average for all boards 752 bytes for the whole U-Boot image, 5868 624 text + 127 data). 5869 5870On ARM, the following registers are used: 5871 5872 R0: function argument word/integer result 5873 R1-R3: function argument word 5874 R9: platform specific 5875 R10: stack limit (used only if stack checking is enabled) 5876 R11: argument (frame) pointer 5877 R12: temporary workspace 5878 R13: stack pointer 5879 R14: link register 5880 R15: program counter 5881 5882 ==> U-Boot will use R9 to hold a pointer to the global data 5883 5884 Note: on ARM, only R_ARM_RELATIVE relocations are supported. 5885 5886On Nios II, the ABI is documented here: 5887 http://www.altera.com/literature/hb/nios2/n2cpu_nii51016.pdf 5888 5889 ==> U-Boot will use gp to hold a pointer to the global data 5890 5891 Note: on Nios II, we give "-G0" option to gcc and don't use gp 5892 to access small data sections, so gp is free. 5893 5894On NDS32, the following registers are used: 5895 5896 R0-R1: argument/return 5897 R2-R5: argument 5898 R15: temporary register for assembler 5899 R16: trampoline register 5900 R28: frame pointer (FP) 5901 R29: global pointer (GP) 5902 R30: link register (LP) 5903 R31: stack pointer (SP) 5904 PC: program counter (PC) 5905 5906 ==> U-Boot will use R10 to hold a pointer to the global data 5907 5908NOTE: DECLARE_GLOBAL_DATA_PTR must be used with file-global scope, 5909or current versions of GCC may "optimize" the code too much. 5910 5911Memory Management: 5912------------------ 5913 5914U-Boot runs in system state and uses physical addresses, i.e. the 5915MMU is not used either for address mapping nor for memory protection. 5916 5917The available memory is mapped to fixed addresses using the memory 5918controller. In this process, a contiguous block is formed for each 5919memory type (Flash, SDRAM, SRAM), even when it consists of several 5920physical memory banks. 5921 5922U-Boot is installed in the first 128 kB of the first Flash bank (on 5923TQM8xxL modules this is the range 0x40000000 ... 0x4001FFFF). After 5924booting and sizing and initializing DRAM, the code relocates itself 5925to the upper end of DRAM. Immediately below the U-Boot code some 5926memory is reserved for use by malloc() [see CONFIG_SYS_MALLOC_LEN 5927configuration setting]. Below that, a structure with global Board 5928Info data is placed, followed by the stack (growing downward). 5929 5930Additionally, some exception handler code is copied to the low 8 kB 5931of DRAM (0x00000000 ... 0x00001FFF). 5932 5933So a typical memory configuration with 16 MB of DRAM could look like 5934this: 5935 5936 0x0000 0000 Exception Vector code 5937 : 5938 0x0000 1FFF 5939 0x0000 2000 Free for Application Use 5940 : 5941 : 5942 5943 : 5944 : 5945 0x00FB FF20 Monitor Stack (Growing downward) 5946 0x00FB FFAC Board Info Data and permanent copy of global data 5947 0x00FC 0000 Malloc Arena 5948 : 5949 0x00FD FFFF 5950 0x00FE 0000 RAM Copy of Monitor Code 5951 ... eventually: LCD or video framebuffer 5952 ... eventually: pRAM (Protected RAM - unchanged by reset) 5953 0x00FF FFFF [End of RAM] 5954 5955 5956System Initialization: 5957---------------------- 5958 5959In the reset configuration, U-Boot starts at the reset entry point 5960(on most PowerPC systems at address 0x00000100). Because of the reset 5961configuration for CS0# this is a mirror of the on board Flash memory. 5962To be able to re-map memory U-Boot then jumps to its link address. 5963To be able to implement the initialization code in C, a (small!) 5964initial stack is set up in the internal Dual Ported RAM (in case CPUs 5965which provide such a feature like MPC8xx or MPC8260), or in a locked 5966part of the data cache. After that, U-Boot initializes the CPU core, 5967the caches and the SIU. 5968 5969Next, all (potentially) available memory banks are mapped using a 5970preliminary mapping. For example, we put them on 512 MB boundaries 5971(multiples of 0x20000000: SDRAM on 0x00000000 and 0x20000000, Flash 5972on 0x40000000 and 0x60000000, SRAM on 0x80000000). Then UPM A is 5973programmed for SDRAM access. Using the temporary configuration, a 5974simple memory test is run that determines the size of the SDRAM 5975banks. 5976 5977When there is more than one SDRAM bank, and the banks are of 5978different size, the largest is mapped first. For equal size, the first 5979bank (CS2#) is mapped first. The first mapping is always for address 59800x00000000, with any additional banks following immediately to create 5981contiguous memory starting from 0. 5982 5983Then, the monitor installs itself at the upper end of the SDRAM area 5984and allocates memory for use by malloc() and for the global Board 5985Info data; also, the exception vector code is copied to the low RAM 5986pages, and the final stack is set up. 5987 5988Only after this relocation will you have a "normal" C environment; 5989until that you are restricted in several ways, mostly because you are 5990running from ROM, and because the code will have to be relocated to a 5991new address in RAM. 5992 5993 5994U-Boot Porting Guide: 5995---------------------- 5996 5997[Based on messages by Jerry Van Baren in the U-Boot-Users mailing 5998list, October 2002] 5999 6000 6001int main(int argc, char *argv[]) 6002{ 6003 sighandler_t no_more_time; 6004 6005 signal(SIGALRM, no_more_time); 6006 alarm(PROJECT_DEADLINE - toSec (3 * WEEK)); 6007 6008 if (available_money > available_manpower) { 6009 Pay consultant to port U-Boot; 6010 return 0; 6011 } 6012 6013 Download latest U-Boot source; 6014 6015 Subscribe to u-boot mailing list; 6016 6017 if (clueless) 6018 email("Hi, I am new to U-Boot, how do I get started?"); 6019 6020 while (learning) { 6021 Read the README file in the top level directory; 6022 Read http://www.denx.de/twiki/bin/view/DULG/Manual; 6023 Read applicable doc/*.README; 6024 Read the source, Luke; 6025 /* find . -name "*.[chS]" | xargs grep -i <keyword> */ 6026 } 6027 6028 if (available_money > toLocalCurrency ($2500)) 6029 Buy a BDI3000; 6030 else 6031 Add a lot of aggravation and time; 6032 6033 if (a similar board exists) { /* hopefully... */ 6034 cp -a board/<similar> board/<myboard> 6035 cp include/configs/<similar>.h include/configs/<myboard>.h 6036 } else { 6037 Create your own board support subdirectory; 6038 Create your own board include/configs/<myboard>.h file; 6039 } 6040 Edit new board/<myboard> files 6041 Edit new include/configs/<myboard>.h 6042 6043 while (!accepted) { 6044 while (!running) { 6045 do { 6046 Add / modify source code; 6047 } until (compiles); 6048 Debug; 6049 if (clueless) 6050 email("Hi, I am having problems..."); 6051 } 6052 Send patch file to the U-Boot email list; 6053 if (reasonable critiques) 6054 Incorporate improvements from email list code review; 6055 else 6056 Defend code as written; 6057 } 6058 6059 return 0; 6060} 6061 6062void no_more_time (int sig) 6063{ 6064 hire_a_guru(); 6065} 6066 6067 6068Coding Standards: 6069----------------- 6070 6071All contributions to U-Boot should conform to the Linux kernel 6072coding style; see the file "Documentation/CodingStyle" and the script 6073"scripts/Lindent" in your Linux kernel source directory. 6074 6075Source files originating from a different project (for example the 6076MTD subsystem) are generally exempt from these guidelines and are not 6077reformatted to ease subsequent migration to newer versions of those 6078sources. 6079 6080Please note that U-Boot is implemented in C (and to some small parts in 6081Assembler); no C++ is used, so please do not use C++ style comments (//) 6082in your code. 6083 6084Please also stick to the following formatting rules: 6085- remove any trailing white space 6086- use TAB characters for indentation and vertical alignment, not spaces 6087- make sure NOT to use DOS '\r\n' line feeds 6088- do not add more than 2 consecutive empty lines to source files 6089- do not add trailing empty lines to source files 6090 6091Submissions which do not conform to the standards may be returned 6092with a request to reformat the changes. 6093 6094 6095Submitting Patches: 6096------------------- 6097 6098Since the number of patches for U-Boot is growing, we need to 6099establish some rules. Submissions which do not conform to these rules 6100may be rejected, even when they contain important and valuable stuff. 6101 6102Please see http://www.denx.de/wiki/U-Boot/Patches for details. 6103 6104Patches shall be sent to the u-boot mailing list <u-boot@lists.denx.de>; 6105see http://lists.denx.de/mailman/listinfo/u-boot 6106 6107When you send a patch, please include the following information with 6108it: 6109 6110* For bug fixes: a description of the bug and how your patch fixes 6111 this bug. Please try to include a way of demonstrating that the 6112 patch actually fixes something. 6113 6114* For new features: a description of the feature and your 6115 implementation. 6116 6117* A CHANGELOG entry as plaintext (separate from the patch) 6118 6119* For major contributions, add a MAINTAINERS file with your 6120 information and associated file and directory references. 6121 6122* When you add support for a new board, don't forget to add a 6123 maintainer e-mail address to the boards.cfg file, too. 6124 6125* If your patch adds new configuration options, don't forget to 6126 document these in the README file. 6127 6128* The patch itself. If you are using git (which is *strongly* 6129 recommended) you can easily generate the patch using the 6130 "git format-patch". If you then use "git send-email" to send it to 6131 the U-Boot mailing list, you will avoid most of the common problems 6132 with some other mail clients. 6133 6134 If you cannot use git, use "diff -purN OLD NEW". If your version of 6135 diff does not support these options, then get the latest version of 6136 GNU diff. 6137 6138 The current directory when running this command shall be the parent 6139 directory of the U-Boot source tree (i. e. please make sure that 6140 your patch includes sufficient directory information for the 6141 affected files). 6142 6143 We prefer patches as plain text. MIME attachments are discouraged, 6144 and compressed attachments must not be used. 6145 6146* If one logical set of modifications affects or creates several 6147 files, all these changes shall be submitted in a SINGLE patch file. 6148 6149* Changesets that contain different, unrelated modifications shall be 6150 submitted as SEPARATE patches, one patch per changeset. 6151 6152 6153Notes: 6154 6155* Before sending the patch, run the buildman script on your patched 6156 source tree and make sure that no errors or warnings are reported 6157 for any of the boards. 6158 6159* Keep your modifications to the necessary minimum: A patch 6160 containing several unrelated changes or arbitrary reformats will be 6161 returned with a request to re-formatting / split it. 6162 6163* If you modify existing code, make sure that your new code does not 6164 add to the memory footprint of the code ;-) Small is beautiful! 6165 When adding new features, these should compile conditionally only 6166 (using #ifdef), and the resulting code with the new feature 6167 disabled must not need more memory than the old code without your 6168 modification. 6169 6170* Remember that there is a size limit of 100 kB per message on the 6171 u-boot mailing list. Bigger patches will be moderated. If they are 6172 reasonable and not too big, they will be acknowledged. But patches 6173 bigger than the size limit should be avoided. 6174