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_CLK * clock command support 830 CONFIG_CMD_CONSOLE coninfo 831 CONFIG_CMD_CRC32 * crc32 832 CONFIG_CMD_DATE * support for RTC, date/time... 833 CONFIG_CMD_DHCP * DHCP support 834 CONFIG_CMD_DIAG * Diagnostics 835 CONFIG_CMD_DS4510 * ds4510 I2C gpio commands 836 CONFIG_CMD_DS4510_INFO * ds4510 I2C info command 837 CONFIG_CMD_DS4510_MEM * ds4510 I2C eeprom/sram commansd 838 CONFIG_CMD_DS4510_RST * ds4510 I2C rst command 839 CONFIG_CMD_DTT * Digital Therm and Thermostat 840 CONFIG_CMD_ECHO echo arguments 841 CONFIG_CMD_EDITENV edit env variable 842 CONFIG_CMD_EEPROM * EEPROM read/write support 843 CONFIG_CMD_EEPROM_LAYOUT* EEPROM layout aware commands 844 CONFIG_CMD_ELF * bootelf, bootvx 845 CONFIG_CMD_ENV_CALLBACK * display details about env callbacks 846 CONFIG_CMD_ENV_FLAGS * display details about env flags 847 CONFIG_CMD_ENV_EXISTS * check existence of env variable 848 CONFIG_CMD_EXPORTENV * export the environment 849 CONFIG_CMD_EXT2 * ext2 command support 850 CONFIG_CMD_EXT4 * ext4 command support 851 CONFIG_CMD_FS_GENERIC * filesystem commands (e.g. load, ls) 852 that work for multiple fs types 853 CONFIG_CMD_FS_UUID * Look up a filesystem UUID 854 CONFIG_CMD_SAVEENV saveenv 855 CONFIG_CMD_FDC * Floppy Disk Support 856 CONFIG_CMD_FAT * FAT command support 857 CONFIG_CMD_FLASH flinfo, erase, protect 858 CONFIG_CMD_FPGA FPGA device initialization support 859 CONFIG_CMD_FUSE * Device fuse support 860 CONFIG_CMD_GETTIME * Get time since boot 861 CONFIG_CMD_GO * the 'go' command (exec code) 862 CONFIG_CMD_GREPENV * search environment 863 CONFIG_CMD_HASH * calculate hash / digest 864 CONFIG_CMD_I2C * I2C serial bus support 865 CONFIG_CMD_IDE * IDE harddisk support 866 CONFIG_CMD_IMI iminfo 867 CONFIG_CMD_IMLS List all images found in NOR flash 868 CONFIG_CMD_IMLS_NAND * List all images found in NAND flash 869 CONFIG_CMD_IMMAP * IMMR dump support 870 CONFIG_CMD_IOTRACE * I/O tracing for debugging 871 CONFIG_CMD_IMPORTENV * import an environment 872 CONFIG_CMD_INI * import data from an ini file into the env 873 CONFIG_CMD_IRQ * irqinfo 874 CONFIG_CMD_ITEST Integer/string test of 2 values 875 CONFIG_CMD_JFFS2 * JFFS2 Support 876 CONFIG_CMD_KGDB * kgdb 877 CONFIG_CMD_LDRINFO * ldrinfo (display Blackfin loader) 878 CONFIG_CMD_LINK_LOCAL * link-local IP address auto-configuration 879 (169.254.*.*) 880 CONFIG_CMD_LOADB loadb 881 CONFIG_CMD_LOADS loads 882 CONFIG_CMD_MD5SUM * print md5 message digest 883 (requires CONFIG_CMD_MEMORY and CONFIG_MD5) 884 CONFIG_CMD_MEMINFO * Display detailed memory information 885 CONFIG_CMD_MEMORY md, mm, nm, mw, cp, cmp, crc, base, 886 loop, loopw 887 CONFIG_CMD_MEMTEST * mtest 888 CONFIG_CMD_MISC Misc functions like sleep etc 889 CONFIG_CMD_MMC * MMC memory mapped support 890 CONFIG_CMD_MII * MII utility commands 891 CONFIG_CMD_MTDPARTS * MTD partition support 892 CONFIG_CMD_NAND * NAND support 893 CONFIG_CMD_NET bootp, tftpboot, rarpboot 894 CONFIG_CMD_NFS NFS support 895 CONFIG_CMD_PCA953X * PCA953x I2C gpio commands 896 CONFIG_CMD_PCA953X_INFO * PCA953x I2C gpio info command 897 CONFIG_CMD_PCI * pciinfo 898 CONFIG_CMD_PCMCIA * PCMCIA support 899 CONFIG_CMD_PING * send ICMP ECHO_REQUEST to network 900 host 901 CONFIG_CMD_PORTIO * Port I/O 902 CONFIG_CMD_READ * Read raw data from partition 903 CONFIG_CMD_REGINFO * Register dump 904 CONFIG_CMD_RUN run command in env variable 905 CONFIG_CMD_SANDBOX * sb command to access sandbox features 906 CONFIG_CMD_SAVES * save S record dump 907 CONFIG_SCSI * SCSI Support 908 CONFIG_CMD_SDRAM * print SDRAM configuration information 909 (requires CONFIG_CMD_I2C) 910 CONFIG_CMD_SETGETDCR Support for DCR Register access 911 (4xx only) 912 CONFIG_CMD_SF * Read/write/erase SPI NOR flash 913 CONFIG_CMD_SHA1SUM * print sha1 memory digest 914 (requires CONFIG_CMD_MEMORY) 915 CONFIG_CMD_SOFTSWITCH * Soft switch setting command for BF60x 916 CONFIG_CMD_SOURCE "source" command Support 917 CONFIG_CMD_SPI * SPI serial bus support 918 CONFIG_CMD_TFTPSRV * TFTP transfer in server mode 919 CONFIG_CMD_TFTPPUT * TFTP put command (upload) 920 CONFIG_CMD_TIME * run command and report execution time (ARM specific) 921 CONFIG_CMD_TIMER * access to the system tick timer 922 CONFIG_CMD_USB * USB support 923 CONFIG_CMD_CDP * Cisco Discover Protocol support 924 CONFIG_CMD_MFSL * Microblaze FSL support 925 CONFIG_CMD_XIMG Load part of Multi Image 926 CONFIG_CMD_UUID * Generate random UUID or GUID string 927 928 EXAMPLE: If you want all functions except of network 929 support you can write: 930 931 #include "config_cmd_all.h" 932 #undef CONFIG_CMD_NET 933 934 Other Commands: 935 fdt (flattened device tree) command: CONFIG_OF_LIBFDT 936 937 Note: Don't enable the "icache" and "dcache" commands 938 (configuration option CONFIG_CMD_CACHE) unless you know 939 what you (and your U-Boot users) are doing. Data 940 cache cannot be enabled on systems like the 8xx or 941 8260 (where accesses to the IMMR region must be 942 uncached), and it cannot be disabled on all other 943 systems where we (mis-) use the data cache to hold an 944 initial stack and some data. 945 946 947 XXX - this list needs to get updated! 948 949- Removal of commands 950 If no commands are needed to boot, you can disable 951 CONFIG_CMDLINE to remove them. In this case, the command line 952 will not be available, and when U-Boot wants to execute the 953 boot command (on start-up) it will call board_run_command() 954 instead. This can reduce image size significantly for very 955 simple boot procedures. 956 957- Regular expression support: 958 CONFIG_REGEX 959 If this variable is defined, U-Boot is linked against 960 the SLRE (Super Light Regular Expression) library, 961 which adds regex support to some commands, as for 962 example "env grep" and "setexpr". 963 964- Device tree: 965 CONFIG_OF_CONTROL 966 If this variable is defined, U-Boot will use a device tree 967 to configure its devices, instead of relying on statically 968 compiled #defines in the board file. This option is 969 experimental and only available on a few boards. The device 970 tree is available in the global data as gd->fdt_blob. 971 972 U-Boot needs to get its device tree from somewhere. This can 973 be done using one of the two options below: 974 975 CONFIG_OF_EMBED 976 If this variable is defined, U-Boot will embed a device tree 977 binary in its image. This device tree file should be in the 978 board directory and called <soc>-<board>.dts. The binary file 979 is then picked up in board_init_f() and made available through 980 the global data structure as gd->blob. 981 982 CONFIG_OF_SEPARATE 983 If this variable is defined, U-Boot will build a device tree 984 binary. It will be called u-boot.dtb. Architecture-specific 985 code will locate it at run-time. Generally this works by: 986 987 cat u-boot.bin u-boot.dtb >image.bin 988 989 and in fact, U-Boot does this for you, creating a file called 990 u-boot-dtb.bin which is useful in the common case. You can 991 still use the individual files if you need something more 992 exotic. 993 994- Watchdog: 995 CONFIG_WATCHDOG 996 If this variable is defined, it enables watchdog 997 support for the SoC. There must be support in the SoC 998 specific code for a watchdog. For the 8xx and 8260 999 CPUs, the SIU Watchdog feature is enabled in the SYPCR 1000 register. When supported for a specific SoC is 1001 available, then no further board specific code should 1002 be needed to use it. 1003 1004 CONFIG_HW_WATCHDOG 1005 When using a watchdog circuitry external to the used 1006 SoC, then define this variable and provide board 1007 specific code for the "hw_watchdog_reset" function. 1008 1009 CONFIG_AT91_HW_WDT_TIMEOUT 1010 specify the timeout in seconds. default 2 seconds. 1011 1012- U-Boot Version: 1013 CONFIG_VERSION_VARIABLE 1014 If this variable is defined, an environment variable 1015 named "ver" is created by U-Boot showing the U-Boot 1016 version as printed by the "version" command. 1017 Any change to this variable will be reverted at the 1018 next reset. 1019 1020- Real-Time Clock: 1021 1022 When CONFIG_CMD_DATE is selected, the type of the RTC 1023 has to be selected, too. Define exactly one of the 1024 following options: 1025 1026 CONFIG_RTC_MPC8xx - use internal RTC of MPC8xx 1027 CONFIG_RTC_PCF8563 - use Philips PCF8563 RTC 1028 CONFIG_RTC_MC13XXX - use MC13783 or MC13892 RTC 1029 CONFIG_RTC_MC146818 - use MC146818 RTC 1030 CONFIG_RTC_DS1307 - use Maxim, Inc. DS1307 RTC 1031 CONFIG_RTC_DS1337 - use Maxim, Inc. DS1337 RTC 1032 CONFIG_RTC_DS1338 - use Maxim, Inc. DS1338 RTC 1033 CONFIG_RTC_DS1339 - use Maxim, Inc. DS1339 RTC 1034 CONFIG_RTC_DS164x - use Dallas DS164x RTC 1035 CONFIG_RTC_ISL1208 - use Intersil ISL1208 RTC 1036 CONFIG_RTC_MAX6900 - use Maxim, Inc. MAX6900 RTC 1037 CONFIG_SYS_RTC_DS1337_NOOSC - Turn off the OSC output for DS1337 1038 CONFIG_SYS_RV3029_TCR - enable trickle charger on 1039 RV3029 RTC. 1040 1041 Note that if the RTC uses I2C, then the I2C interface 1042 must also be configured. See I2C Support, below. 1043 1044- GPIO Support: 1045 CONFIG_PCA953X - use NXP's PCA953X series I2C GPIO 1046 1047 The CONFIG_SYS_I2C_PCA953X_WIDTH option specifies a list of 1048 chip-ngpio pairs that tell the PCA953X driver the number of 1049 pins supported by a particular chip. 1050 1051 Note that if the GPIO device uses I2C, then the I2C interface 1052 must also be configured. See I2C Support, below. 1053 1054- I/O tracing: 1055 When CONFIG_IO_TRACE is selected, U-Boot intercepts all I/O 1056 accesses and can checksum them or write a list of them out 1057 to memory. See the 'iotrace' command for details. This is 1058 useful for testing device drivers since it can confirm that 1059 the driver behaves the same way before and after a code 1060 change. Currently this is supported on sandbox and arm. To 1061 add support for your architecture, add '#include <iotrace.h>' 1062 to the bottom of arch/<arch>/include/asm/io.h and test. 1063 1064 Example output from the 'iotrace stats' command is below. 1065 Note that if the trace buffer is exhausted, the checksum will 1066 still continue to operate. 1067 1068 iotrace is enabled 1069 Start: 10000000 (buffer start address) 1070 Size: 00010000 (buffer size) 1071 Offset: 00000120 (current buffer offset) 1072 Output: 10000120 (start + offset) 1073 Count: 00000018 (number of trace records) 1074 CRC32: 9526fb66 (CRC32 of all trace records) 1075 1076- Timestamp Support: 1077 1078 When CONFIG_TIMESTAMP is selected, the timestamp 1079 (date and time) of an image is printed by image 1080 commands like bootm or iminfo. This option is 1081 automatically enabled when you select CONFIG_CMD_DATE . 1082 1083- Partition Labels (disklabels) Supported: 1084 Zero or more of the following: 1085 CONFIG_MAC_PARTITION Apple's MacOS partition table. 1086 CONFIG_DOS_PARTITION MS Dos partition table, traditional on the 1087 Intel architecture, USB sticks, etc. 1088 CONFIG_ISO_PARTITION ISO partition table, used on CDROM etc. 1089 CONFIG_EFI_PARTITION GPT partition table, common when EFI is the 1090 bootloader. Note 2TB partition limit; see 1091 disk/part_efi.c 1092 CONFIG_MTD_PARTITIONS Memory Technology Device partition table. 1093 1094 If IDE or SCSI support is enabled (CONFIG_CMD_IDE or 1095 CONFIG_SCSI) you must configure support for at 1096 least one non-MTD partition type as well. 1097 1098- IDE Reset method: 1099 CONFIG_IDE_RESET_ROUTINE - this is defined in several 1100 board configurations files but used nowhere! 1101 1102 CONFIG_IDE_RESET - is this is defined, IDE Reset will 1103 be performed by calling the function 1104 ide_set_reset(int reset) 1105 which has to be defined in a board specific file 1106 1107- ATAPI Support: 1108 CONFIG_ATAPI 1109 1110 Set this to enable ATAPI support. 1111 1112- LBA48 Support 1113 CONFIG_LBA48 1114 1115 Set this to enable support for disks larger than 137GB 1116 Also look at CONFIG_SYS_64BIT_LBA. 1117 Whithout these , LBA48 support uses 32bit variables and will 'only' 1118 support disks up to 2.1TB. 1119 1120 CONFIG_SYS_64BIT_LBA: 1121 When enabled, makes the IDE subsystem use 64bit sector addresses. 1122 Default is 32bit. 1123 1124- SCSI Support: 1125 At the moment only there is only support for the 1126 SYM53C8XX SCSI controller; define 1127 CONFIG_SCSI_SYM53C8XX to enable it. 1128 1129 CONFIG_SYS_SCSI_MAX_LUN [8], CONFIG_SYS_SCSI_MAX_SCSI_ID [7] and 1130 CONFIG_SYS_SCSI_MAX_DEVICE [CONFIG_SYS_SCSI_MAX_SCSI_ID * 1131 CONFIG_SYS_SCSI_MAX_LUN] can be adjusted to define the 1132 maximum numbers of LUNs, SCSI ID's and target 1133 devices. 1134 CONFIG_SYS_SCSI_SYM53C8XX_CCF to fix clock timing (80Mhz) 1135 1136 The environment variable 'scsidevs' is set to the number of 1137 SCSI devices found during the last scan. 1138 1139- NETWORK Support (PCI): 1140 CONFIG_E1000 1141 Support for Intel 8254x/8257x gigabit chips. 1142 1143 CONFIG_E1000_SPI 1144 Utility code for direct access to the SPI bus on Intel 8257x. 1145 This does not do anything useful unless you set at least one 1146 of CONFIG_CMD_E1000 or CONFIG_E1000_SPI_GENERIC. 1147 1148 CONFIG_E1000_SPI_GENERIC 1149 Allow generic access to the SPI bus on the Intel 8257x, for 1150 example with the "sspi" command. 1151 1152 CONFIG_CMD_E1000 1153 Management command for E1000 devices. When used on devices 1154 with SPI support you can reprogram the EEPROM from U-Boot. 1155 1156 CONFIG_EEPRO100 1157 Support for Intel 82557/82559/82559ER chips. 1158 Optional CONFIG_EEPRO100_SROM_WRITE enables EEPROM 1159 write routine for first time initialisation. 1160 1161 CONFIG_TULIP 1162 Support for Digital 2114x chips. 1163 Optional CONFIG_TULIP_SELECT_MEDIA for board specific 1164 modem chip initialisation (KS8761/QS6611). 1165 1166 CONFIG_NATSEMI 1167 Support for National dp83815 chips. 1168 1169 CONFIG_NS8382X 1170 Support for National dp8382[01] gigabit chips. 1171 1172- NETWORK Support (other): 1173 1174 CONFIG_DRIVER_AT91EMAC 1175 Support for AT91RM9200 EMAC. 1176 1177 CONFIG_RMII 1178 Define this to use reduced MII inteface 1179 1180 CONFIG_DRIVER_AT91EMAC_QUIET 1181 If this defined, the driver is quiet. 1182 The driver doen't show link status messages. 1183 1184 CONFIG_CALXEDA_XGMAC 1185 Support for the Calxeda XGMAC device 1186 1187 CONFIG_LAN91C96 1188 Support for SMSC's LAN91C96 chips. 1189 1190 CONFIG_LAN91C96_USE_32_BIT 1191 Define this to enable 32 bit addressing 1192 1193 CONFIG_SMC91111 1194 Support for SMSC's LAN91C111 chip 1195 1196 CONFIG_SMC91111_BASE 1197 Define this to hold the physical address 1198 of the device (I/O space) 1199 1200 CONFIG_SMC_USE_32_BIT 1201 Define this if data bus is 32 bits 1202 1203 CONFIG_SMC_USE_IOFUNCS 1204 Define this to use i/o functions instead of macros 1205 (some hardware wont work with macros) 1206 1207 CONFIG_DRIVER_TI_EMAC 1208 Support for davinci emac 1209 1210 CONFIG_SYS_DAVINCI_EMAC_PHY_COUNT 1211 Define this if you have more then 3 PHYs. 1212 1213 CONFIG_FTGMAC100 1214 Support for Faraday's FTGMAC100 Gigabit SoC Ethernet 1215 1216 CONFIG_FTGMAC100_EGIGA 1217 Define this to use GE link update with gigabit PHY. 1218 Define this if FTGMAC100 is connected to gigabit PHY. 1219 If your system has 10/100 PHY only, it might not occur 1220 wrong behavior. Because PHY usually return timeout or 1221 useless data when polling gigabit status and gigabit 1222 control registers. This behavior won't affect the 1223 correctnessof 10/100 link speed update. 1224 1225 CONFIG_SMC911X 1226 Support for SMSC's LAN911x and LAN921x chips 1227 1228 CONFIG_SMC911X_BASE 1229 Define this to hold the physical address 1230 of the device (I/O space) 1231 1232 CONFIG_SMC911X_32_BIT 1233 Define this if data bus is 32 bits 1234 1235 CONFIG_SMC911X_16_BIT 1236 Define this if data bus is 16 bits. If your processor 1237 automatically converts one 32 bit word to two 16 bit 1238 words you may also try CONFIG_SMC911X_32_BIT. 1239 1240 CONFIG_SH_ETHER 1241 Support for Renesas on-chip Ethernet controller 1242 1243 CONFIG_SH_ETHER_USE_PORT 1244 Define the number of ports to be used 1245 1246 CONFIG_SH_ETHER_PHY_ADDR 1247 Define the ETH PHY's address 1248 1249 CONFIG_SH_ETHER_CACHE_WRITEBACK 1250 If this option is set, the driver enables cache flush. 1251 1252- PWM Support: 1253 CONFIG_PWM_IMX 1254 Support for PWM module on the imx6. 1255 1256- TPM Support: 1257 CONFIG_TPM 1258 Support TPM devices. 1259 1260 CONFIG_TPM_TIS_INFINEON 1261 Support for Infineon i2c bus TPM devices. Only one device 1262 per system is supported at this time. 1263 1264 CONFIG_TPM_TIS_I2C_BURST_LIMITATION 1265 Define the burst count bytes upper limit 1266 1267 CONFIG_TPM_ST33ZP24 1268 Support for STMicroelectronics TPM devices. Requires DM_TPM support. 1269 1270 CONFIG_TPM_ST33ZP24_I2C 1271 Support for STMicroelectronics ST33ZP24 I2C devices. 1272 Requires TPM_ST33ZP24 and I2C. 1273 1274 CONFIG_TPM_ST33ZP24_SPI 1275 Support for STMicroelectronics ST33ZP24 SPI devices. 1276 Requires TPM_ST33ZP24 and SPI. 1277 1278 CONFIG_TPM_ATMEL_TWI 1279 Support for Atmel TWI TPM device. Requires I2C support. 1280 1281 CONFIG_TPM_TIS_LPC 1282 Support for generic parallel port TPM devices. Only one device 1283 per system is supported at this time. 1284 1285 CONFIG_TPM_TIS_BASE_ADDRESS 1286 Base address where the generic TPM device is mapped 1287 to. Contemporary x86 systems usually map it at 1288 0xfed40000. 1289 1290 CONFIG_CMD_TPM 1291 Add tpm monitor functions. 1292 Requires CONFIG_TPM. If CONFIG_TPM_AUTH_SESSIONS is set, also 1293 provides monitor access to authorized functions. 1294 1295 CONFIG_TPM 1296 Define this to enable the TPM support library which provides 1297 functional interfaces to some TPM commands. 1298 Requires support for a TPM device. 1299 1300 CONFIG_TPM_AUTH_SESSIONS 1301 Define this to enable authorized functions in the TPM library. 1302 Requires CONFIG_TPM and CONFIG_SHA1. 1303 1304- USB Support: 1305 At the moment only the UHCI host controller is 1306 supported (PIP405, MIP405, MPC5200); define 1307 CONFIG_USB_UHCI to enable it. 1308 define CONFIG_USB_KEYBOARD to enable the USB Keyboard 1309 and define CONFIG_USB_STORAGE to enable the USB 1310 storage devices. 1311 Note: 1312 Supported are USB Keyboards and USB Floppy drives 1313 (TEAC FD-05PUB). 1314 MPC5200 USB requires additional defines: 1315 CONFIG_USB_CLOCK 1316 for 528 MHz Clock: 0x0001bbbb 1317 CONFIG_PSC3_USB 1318 for USB on PSC3 1319 CONFIG_USB_CONFIG 1320 for differential drivers: 0x00001000 1321 for single ended drivers: 0x00005000 1322 for differential drivers on PSC3: 0x00000100 1323 for single ended drivers on PSC3: 0x00004100 1324 CONFIG_SYS_USB_EVENT_POLL 1325 May be defined to allow interrupt polling 1326 instead of using asynchronous interrupts 1327 1328 CONFIG_USB_EHCI_TXFIFO_THRESH enables setting of the 1329 txfilltuning field in the EHCI controller on reset. 1330 1331 CONFIG_USB_DWC2_REG_ADDR the physical CPU address of the DWC2 1332 HW module registers. 1333 1334- USB Device: 1335 Define the below if you wish to use the USB console. 1336 Once firmware is rebuilt from a serial console issue the 1337 command "setenv stdin usbtty; setenv stdout usbtty" and 1338 attach your USB cable. The Unix command "dmesg" should print 1339 it has found a new device. The environment variable usbtty 1340 can be set to gserial or cdc_acm to enable your device to 1341 appear to a USB host as a Linux gserial device or a 1342 Common Device Class Abstract Control Model serial device. 1343 If you select usbtty = gserial you should be able to enumerate 1344 a Linux host by 1345 # modprobe usbserial vendor=0xVendorID product=0xProductID 1346 else if using cdc_acm, simply setting the environment 1347 variable usbtty to be cdc_acm should suffice. The following 1348 might be defined in YourBoardName.h 1349 1350 CONFIG_USB_DEVICE 1351 Define this to build a UDC device 1352 1353 CONFIG_USB_TTY 1354 Define this to have a tty type of device available to 1355 talk to the UDC device 1356 1357 CONFIG_USBD_HS 1358 Define this to enable the high speed support for usb 1359 device and usbtty. If this feature is enabled, a routine 1360 int is_usbd_high_speed(void) 1361 also needs to be defined by the driver to dynamically poll 1362 whether the enumeration has succeded at high speed or full 1363 speed. 1364 1365 CONFIG_SYS_CONSOLE_IS_IN_ENV 1366 Define this if you want stdin, stdout &/or stderr to 1367 be set to usbtty. 1368 1369 mpc8xx: 1370 CONFIG_SYS_USB_EXTC_CLK 0xBLAH 1371 Derive USB clock from external clock "blah" 1372 - CONFIG_SYS_USB_EXTC_CLK 0x02 1373 1374 If you have a USB-IF assigned VendorID then you may wish to 1375 define your own vendor specific values either in BoardName.h 1376 or directly in usbd_vendor_info.h. If you don't define 1377 CONFIG_USBD_MANUFACTURER, CONFIG_USBD_PRODUCT_NAME, 1378 CONFIG_USBD_VENDORID and CONFIG_USBD_PRODUCTID, then U-Boot 1379 should pretend to be a Linux device to it's target host. 1380 1381 CONFIG_USBD_MANUFACTURER 1382 Define this string as the name of your company for 1383 - CONFIG_USBD_MANUFACTURER "my company" 1384 1385 CONFIG_USBD_PRODUCT_NAME 1386 Define this string as the name of your product 1387 - CONFIG_USBD_PRODUCT_NAME "acme usb device" 1388 1389 CONFIG_USBD_VENDORID 1390 Define this as your assigned Vendor ID from the USB 1391 Implementors Forum. This *must* be a genuine Vendor ID 1392 to avoid polluting the USB namespace. 1393 - CONFIG_USBD_VENDORID 0xFFFF 1394 1395 CONFIG_USBD_PRODUCTID 1396 Define this as the unique Product ID 1397 for your device 1398 - CONFIG_USBD_PRODUCTID 0xFFFF 1399 1400- ULPI Layer Support: 1401 The ULPI (UTMI Low Pin (count) Interface) PHYs are supported via 1402 the generic ULPI layer. The generic layer accesses the ULPI PHY 1403 via the platform viewport, so you need both the genric layer and 1404 the viewport enabled. Currently only Chipidea/ARC based 1405 viewport is supported. 1406 To enable the ULPI layer support, define CONFIG_USB_ULPI and 1407 CONFIG_USB_ULPI_VIEWPORT in your board configuration file. 1408 If your ULPI phy needs a different reference clock than the 1409 standard 24 MHz then you have to define CONFIG_ULPI_REF_CLK to 1410 the appropriate value in Hz. 1411 1412- MMC Support: 1413 The MMC controller on the Intel PXA is supported. To 1414 enable this define CONFIG_MMC. The MMC can be 1415 accessed from the boot prompt by mapping the device 1416 to physical memory similar to flash. Command line is 1417 enabled with CONFIG_CMD_MMC. The MMC driver also works with 1418 the FAT fs. This is enabled with CONFIG_CMD_FAT. 1419 1420 CONFIG_SH_MMCIF 1421 Support for Renesas on-chip MMCIF controller 1422 1423 CONFIG_SH_MMCIF_ADDR 1424 Define the base address of MMCIF registers 1425 1426 CONFIG_SH_MMCIF_CLK 1427 Define the clock frequency for MMCIF 1428 1429 CONFIG_SUPPORT_EMMC_BOOT 1430 Enable some additional features of the eMMC boot partitions. 1431 1432 CONFIG_SUPPORT_EMMC_RPMB 1433 Enable the commands for reading, writing and programming the 1434 key for the Replay Protection Memory Block partition in eMMC. 1435 1436- USB Device Firmware Update (DFU) class support: 1437 CONFIG_USB_FUNCTION_DFU 1438 This enables the USB portion of the DFU USB class 1439 1440 CONFIG_CMD_DFU 1441 This enables the command "dfu" which is used to have 1442 U-Boot create a DFU class device via USB. This command 1443 requires that the "dfu_alt_info" environment variable be 1444 set and define the alt settings to expose to the host. 1445 1446 CONFIG_DFU_MMC 1447 This enables support for exposing (e)MMC devices via DFU. 1448 1449 CONFIG_DFU_NAND 1450 This enables support for exposing NAND devices via DFU. 1451 1452 CONFIG_DFU_RAM 1453 This enables support for exposing RAM via DFU. 1454 Note: DFU spec refer to non-volatile memory usage, but 1455 allow usages beyond the scope of spec - here RAM usage, 1456 one that would help mostly the developer. 1457 1458 CONFIG_SYS_DFU_DATA_BUF_SIZE 1459 Dfu transfer uses a buffer before writing data to the 1460 raw storage device. Make the size (in bytes) of this buffer 1461 configurable. The size of this buffer is also configurable 1462 through the "dfu_bufsiz" environment variable. 1463 1464 CONFIG_SYS_DFU_MAX_FILE_SIZE 1465 When updating files rather than the raw storage device, 1466 we use a static buffer to copy the file into and then write 1467 the buffer once we've been given the whole file. Define 1468 this to the maximum filesize (in bytes) for the buffer. 1469 Default is 4 MiB if undefined. 1470 1471 DFU_DEFAULT_POLL_TIMEOUT 1472 Poll timeout [ms], is the timeout a device can send to the 1473 host. The host must wait for this timeout before sending 1474 a subsequent DFU_GET_STATUS request to the device. 1475 1476 DFU_MANIFEST_POLL_TIMEOUT 1477 Poll timeout [ms], which the device sends to the host when 1478 entering dfuMANIFEST state. Host waits this timeout, before 1479 sending again an USB request to the device. 1480 1481- USB Device Android Fastboot support: 1482 CONFIG_USB_FUNCTION_FASTBOOT 1483 This enables the USB part of the fastboot gadget 1484 1485 CONFIG_CMD_FASTBOOT 1486 This enables the command "fastboot" which enables the Android 1487 fastboot mode for the platform's USB device. Fastboot is a USB 1488 protocol for downloading images, flashing and device control 1489 used on Android devices. 1490 See doc/README.android-fastboot for more information. 1491 1492 CONFIG_ANDROID_BOOT_IMAGE 1493 This enables support for booting images which use the Android 1494 image format header. 1495 1496 CONFIG_FASTBOOT_BUF_ADDR 1497 The fastboot protocol requires a large memory buffer for 1498 downloads. Define this to the starting RAM address to use for 1499 downloaded images. 1500 1501 CONFIG_FASTBOOT_BUF_SIZE 1502 The fastboot protocol requires a large memory buffer for 1503 downloads. This buffer should be as large as possible for a 1504 platform. Define this to the size available RAM for fastboot. 1505 1506 CONFIG_FASTBOOT_FLASH 1507 The fastboot protocol includes a "flash" command for writing 1508 the downloaded image to a non-volatile storage device. Define 1509 this to enable the "fastboot flash" command. 1510 1511 CONFIG_FASTBOOT_FLASH_MMC_DEV 1512 The fastboot "flash" command requires additional information 1513 regarding the non-volatile storage device. Define this to 1514 the eMMC device that fastboot should use to store the image. 1515 1516 CONFIG_FASTBOOT_GPT_NAME 1517 The fastboot "flash" command supports writing the downloaded 1518 image to the Protective MBR and the Primary GUID Partition 1519 Table. (Additionally, this downloaded image is post-processed 1520 to generate and write the Backup GUID Partition Table.) 1521 This occurs when the specified "partition name" on the 1522 "fastboot flash" command line matches this value. 1523 The default is "gpt" if undefined. 1524 1525 CONFIG_FASTBOOT_MBR_NAME 1526 The fastboot "flash" command supports writing the downloaded 1527 image to DOS MBR. 1528 This occurs when the "partition name" specified on the 1529 "fastboot flash" command line matches this value. 1530 If not defined the default value "mbr" is used. 1531 1532- Journaling Flash filesystem support: 1533 CONFIG_JFFS2_NAND 1534 Define these for a default partition on a NAND device 1535 1536 CONFIG_SYS_JFFS2_FIRST_SECTOR, 1537 CONFIG_SYS_JFFS2_FIRST_BANK, CONFIG_SYS_JFFS2_NUM_BANKS 1538 Define these for a default partition on a NOR device 1539 1540- FAT(File Allocation Table) filesystem write function support: 1541 CONFIG_FAT_WRITE 1542 1543 Define this to enable support for saving memory data as a 1544 file in FAT formatted partition. 1545 1546 This will also enable the command "fatwrite" enabling the 1547 user to write files to FAT. 1548 1549- CBFS (Coreboot Filesystem) support: 1550 CONFIG_CMD_CBFS 1551 1552 Define this to enable support for reading from a Coreboot 1553 filesystem. Available commands are cbfsinit, cbfsinfo, cbfsls 1554 and cbfsload. 1555 1556- FAT(File Allocation Table) filesystem cluster size: 1557 CONFIG_FS_FAT_MAX_CLUSTSIZE 1558 1559 Define the max cluster size for fat operations else 1560 a default value of 65536 will be defined. 1561 1562- Keyboard Support: 1563 See Kconfig help for available keyboard drivers. 1564 1565 CONFIG_KEYBOARD 1566 1567 Define this to enable a custom keyboard support. 1568 This simply calls drv_keyboard_init() which must be 1569 defined in your board-specific files. This option is deprecated 1570 and is only used by novena. For new boards, use driver model 1571 instead. 1572 1573- Video support: 1574 CONFIG_FSL_DIU_FB 1575 Enable the Freescale DIU video driver. Reference boards for 1576 SOCs that have a DIU should define this macro to enable DIU 1577 support, and should also define these other macros: 1578 1579 CONFIG_SYS_DIU_ADDR 1580 CONFIG_VIDEO 1581 CONFIG_CFB_CONSOLE 1582 CONFIG_VIDEO_SW_CURSOR 1583 CONFIG_VGA_AS_SINGLE_DEVICE 1584 CONFIG_VIDEO_LOGO 1585 CONFIG_VIDEO_BMP_LOGO 1586 1587 The DIU driver will look for the 'video-mode' environment 1588 variable, and if defined, enable the DIU as a console during 1589 boot. See the documentation file doc/README.video for a 1590 description of this variable. 1591 1592- LCD Support: CONFIG_LCD 1593 1594 Define this to enable LCD support (for output to LCD 1595 display); also select one of the supported displays 1596 by defining one of these: 1597 1598 CONFIG_ATMEL_LCD: 1599 1600 HITACHI TX09D70VM1CCA, 3.5", 240x320. 1601 1602 CONFIG_NEC_NL6448AC33: 1603 1604 NEC NL6448AC33-18. Active, color, single scan. 1605 1606 CONFIG_NEC_NL6448BC20 1607 1608 NEC NL6448BC20-08. 6.5", 640x480. 1609 Active, color, single scan. 1610 1611 CONFIG_NEC_NL6448BC33_54 1612 1613 NEC NL6448BC33-54. 10.4", 640x480. 1614 Active, color, single scan. 1615 1616 CONFIG_SHARP_16x9 1617 1618 Sharp 320x240. Active, color, single scan. 1619 It isn't 16x9, and I am not sure what it is. 1620 1621 CONFIG_SHARP_LQ64D341 1622 1623 Sharp LQ64D341 display, 640x480. 1624 Active, color, single scan. 1625 1626 CONFIG_HLD1045 1627 1628 HLD1045 display, 640x480. 1629 Active, color, single scan. 1630 1631 CONFIG_OPTREX_BW 1632 1633 Optrex CBL50840-2 NF-FW 99 22 M5 1634 or 1635 Hitachi LMG6912RPFC-00T 1636 or 1637 Hitachi SP14Q002 1638 1639 320x240. Black & white. 1640 1641 Normally display is black on white background; define 1642 CONFIG_SYS_WHITE_ON_BLACK to get it inverted. 1643 1644 CONFIG_LCD_ALIGNMENT 1645 1646 Normally the LCD is page-aligned (typically 4KB). If this is 1647 defined then the LCD will be aligned to this value instead. 1648 For ARM it is sometimes useful to use MMU_SECTION_SIZE 1649 here, since it is cheaper to change data cache settings on 1650 a per-section basis. 1651 1652 1653 CONFIG_LCD_ROTATION 1654 1655 Sometimes, for example if the display is mounted in portrait 1656 mode or even if it's mounted landscape but rotated by 180degree, 1657 we need to rotate our content of the display relative to the 1658 framebuffer, so that user can read the messages which are 1659 printed out. 1660 Once CONFIG_LCD_ROTATION is defined, the lcd_console will be 1661 initialized with a given rotation from "vl_rot" out of 1662 "vidinfo_t" which is provided by the board specific code. 1663 The value for vl_rot is coded as following (matching to 1664 fbcon=rotate:<n> linux-kernel commandline): 1665 0 = no rotation respectively 0 degree 1666 1 = 90 degree rotation 1667 2 = 180 degree rotation 1668 3 = 270 degree rotation 1669 1670 If CONFIG_LCD_ROTATION is not defined, the console will be 1671 initialized with 0degree rotation. 1672 1673 CONFIG_LCD_BMP_RLE8 1674 1675 Support drawing of RLE8-compressed bitmaps on the LCD. 1676 1677 CONFIG_I2C_EDID 1678 1679 Enables an 'i2c edid' command which can read EDID 1680 information over I2C from an attached LCD display. 1681 1682- Splash Screen Support: CONFIG_SPLASH_SCREEN 1683 1684 If this option is set, the environment is checked for 1685 a variable "splashimage". If found, the usual display 1686 of logo, copyright and system information on the LCD 1687 is suppressed and the BMP image at the address 1688 specified in "splashimage" is loaded instead. The 1689 console is redirected to the "nulldev", too. This 1690 allows for a "silent" boot where a splash screen is 1691 loaded very quickly after power-on. 1692 1693 CONFIG_SPLASHIMAGE_GUARD 1694 1695 If this option is set, then U-Boot will prevent the environment 1696 variable "splashimage" from being set to a problematic address 1697 (see doc/README.displaying-bmps). 1698 This option is useful for targets where, due to alignment 1699 restrictions, an improperly aligned BMP image will cause a data 1700 abort. If you think you will not have problems with unaligned 1701 accesses (for example because your toolchain prevents them) 1702 there is no need to set this option. 1703 1704 CONFIG_SPLASH_SCREEN_ALIGN 1705 1706 If this option is set the splash image can be freely positioned 1707 on the screen. Environment variable "splashpos" specifies the 1708 position as "x,y". If a positive number is given it is used as 1709 number of pixel from left/top. If a negative number is given it 1710 is used as number of pixel from right/bottom. You can also 1711 specify 'm' for centering the image. 1712 1713 Example: 1714 setenv splashpos m,m 1715 => image at center of screen 1716 1717 setenv splashpos 30,20 1718 => image at x = 30 and y = 20 1719 1720 setenv splashpos -10,m 1721 => vertically centered image 1722 at x = dspWidth - bmpWidth - 9 1723 1724- Gzip compressed BMP image support: CONFIG_VIDEO_BMP_GZIP 1725 1726 If this option is set, additionally to standard BMP 1727 images, gzipped BMP images can be displayed via the 1728 splashscreen support or the bmp command. 1729 1730- Run length encoded BMP image (RLE8) support: CONFIG_VIDEO_BMP_RLE8 1731 1732 If this option is set, 8-bit RLE compressed BMP images 1733 can be displayed via the splashscreen support or the 1734 bmp command. 1735 1736- Compression support: 1737 CONFIG_GZIP 1738 1739 Enabled by default to support gzip compressed images. 1740 1741 CONFIG_BZIP2 1742 1743 If this option is set, support for bzip2 compressed 1744 images is included. If not, only uncompressed and gzip 1745 compressed images are supported. 1746 1747 NOTE: the bzip2 algorithm requires a lot of RAM, so 1748 the malloc area (as defined by CONFIG_SYS_MALLOC_LEN) should 1749 be at least 4MB. 1750 1751 CONFIG_LZMA 1752 1753 If this option is set, support for lzma compressed 1754 images is included. 1755 1756 Note: The LZMA algorithm adds between 2 and 4KB of code and it 1757 requires an amount of dynamic memory that is given by the 1758 formula: 1759 1760 (1846 + 768 << (lc + lp)) * sizeof(uint16) 1761 1762 Where lc and lp stand for, respectively, Literal context bits 1763 and Literal pos bits. 1764 1765 This value is upper-bounded by 14MB in the worst case. Anyway, 1766 for a ~4MB large kernel image, we have lc=3 and lp=0 for a 1767 total amount of (1846 + 768 << (3 + 0)) * 2 = ~41KB... that is 1768 a very small buffer. 1769 1770 Use the lzmainfo tool to determinate the lc and lp values and 1771 then calculate the amount of needed dynamic memory (ensuring 1772 the appropriate CONFIG_SYS_MALLOC_LEN value). 1773 1774 CONFIG_LZO 1775 1776 If this option is set, support for LZO compressed images 1777 is included. 1778 1779- MII/PHY support: 1780 CONFIG_PHY_ADDR 1781 1782 The address of PHY on MII bus. 1783 1784 CONFIG_PHY_CLOCK_FREQ (ppc4xx) 1785 1786 The clock frequency of the MII bus 1787 1788 CONFIG_PHY_GIGE 1789 1790 If this option is set, support for speed/duplex 1791 detection of gigabit PHY is included. 1792 1793 CONFIG_PHY_RESET_DELAY 1794 1795 Some PHY like Intel LXT971A need extra delay after 1796 reset before any MII register access is possible. 1797 For such PHY, set this option to the usec delay 1798 required. (minimum 300usec for LXT971A) 1799 1800 CONFIG_PHY_CMD_DELAY (ppc4xx) 1801 1802 Some PHY like Intel LXT971A need extra delay after 1803 command issued before MII status register can be read 1804 1805- IP address: 1806 CONFIG_IPADDR 1807 1808 Define a default value for the IP address to use for 1809 the default Ethernet interface, in case this is not 1810 determined through e.g. bootp. 1811 (Environment variable "ipaddr") 1812 1813- Server IP address: 1814 CONFIG_SERVERIP 1815 1816 Defines a default value for the IP address of a TFTP 1817 server to contact when using the "tftboot" command. 1818 (Environment variable "serverip") 1819 1820 CONFIG_KEEP_SERVERADDR 1821 1822 Keeps the server's MAC address, in the env 'serveraddr' 1823 for passing to bootargs (like Linux's netconsole option) 1824 1825- Gateway IP address: 1826 CONFIG_GATEWAYIP 1827 1828 Defines a default value for the IP address of the 1829 default router where packets to other networks are 1830 sent to. 1831 (Environment variable "gatewayip") 1832 1833- Subnet mask: 1834 CONFIG_NETMASK 1835 1836 Defines a default value for the subnet mask (or 1837 routing prefix) which is used to determine if an IP 1838 address belongs to the local subnet or needs to be 1839 forwarded through a router. 1840 (Environment variable "netmask") 1841 1842- Multicast TFTP Mode: 1843 CONFIG_MCAST_TFTP 1844 1845 Defines whether you want to support multicast TFTP as per 1846 rfc-2090; for example to work with atftp. Lets lots of targets 1847 tftp down the same boot image concurrently. Note: the Ethernet 1848 driver in use must provide a function: mcast() to join/leave a 1849 multicast group. 1850 1851- BOOTP Recovery Mode: 1852 CONFIG_BOOTP_RANDOM_DELAY 1853 1854 If you have many targets in a network that try to 1855 boot using BOOTP, you may want to avoid that all 1856 systems send out BOOTP requests at precisely the same 1857 moment (which would happen for instance at recovery 1858 from a power failure, when all systems will try to 1859 boot, thus flooding the BOOTP server. Defining 1860 CONFIG_BOOTP_RANDOM_DELAY causes a random delay to be 1861 inserted before sending out BOOTP requests. The 1862 following delays are inserted then: 1863 1864 1st BOOTP request: delay 0 ... 1 sec 1865 2nd BOOTP request: delay 0 ... 2 sec 1866 3rd BOOTP request: delay 0 ... 4 sec 1867 4th and following 1868 BOOTP requests: delay 0 ... 8 sec 1869 1870 CONFIG_BOOTP_ID_CACHE_SIZE 1871 1872 BOOTP packets are uniquely identified using a 32-bit ID. The 1873 server will copy the ID from client requests to responses and 1874 U-Boot will use this to determine if it is the destination of 1875 an incoming response. Some servers will check that addresses 1876 aren't in use before handing them out (usually using an ARP 1877 ping) and therefore take up to a few hundred milliseconds to 1878 respond. Network congestion may also influence the time it 1879 takes for a response to make it back to the client. If that 1880 time is too long, U-Boot will retransmit requests. In order 1881 to allow earlier responses to still be accepted after these 1882 retransmissions, U-Boot's BOOTP client keeps a small cache of 1883 IDs. The CONFIG_BOOTP_ID_CACHE_SIZE controls the size of this 1884 cache. The default is to keep IDs for up to four outstanding 1885 requests. Increasing this will allow U-Boot to accept offers 1886 from a BOOTP client in networks with unusually high latency. 1887 1888- DHCP Advanced Options: 1889 You can fine tune the DHCP functionality by defining 1890 CONFIG_BOOTP_* symbols: 1891 1892 CONFIG_BOOTP_SUBNETMASK 1893 CONFIG_BOOTP_GATEWAY 1894 CONFIG_BOOTP_HOSTNAME 1895 CONFIG_BOOTP_NISDOMAIN 1896 CONFIG_BOOTP_BOOTPATH 1897 CONFIG_BOOTP_BOOTFILESIZE 1898 CONFIG_BOOTP_DNS 1899 CONFIG_BOOTP_DNS2 1900 CONFIG_BOOTP_SEND_HOSTNAME 1901 CONFIG_BOOTP_NTPSERVER 1902 CONFIG_BOOTP_TIMEOFFSET 1903 CONFIG_BOOTP_VENDOREX 1904 CONFIG_BOOTP_MAY_FAIL 1905 1906 CONFIG_BOOTP_SERVERIP - TFTP server will be the serverip 1907 environment variable, not the BOOTP server. 1908 1909 CONFIG_BOOTP_MAY_FAIL - If the DHCP server is not found 1910 after the configured retry count, the call will fail 1911 instead of starting over. This can be used to fail over 1912 to Link-local IP address configuration if the DHCP server 1913 is not available. 1914 1915 CONFIG_BOOTP_DNS2 - If a DHCP client requests the DNS 1916 serverip from a DHCP server, it is possible that more 1917 than one DNS serverip is offered to the client. 1918 If CONFIG_BOOTP_DNS2 is enabled, the secondary DNS 1919 serverip will be stored in the additional environment 1920 variable "dnsip2". The first DNS serverip is always 1921 stored in the variable "dnsip", when CONFIG_BOOTP_DNS 1922 is defined. 1923 1924 CONFIG_BOOTP_SEND_HOSTNAME - Some DHCP servers are capable 1925 to do a dynamic update of a DNS server. To do this, they 1926 need the hostname of the DHCP requester. 1927 If CONFIG_BOOTP_SEND_HOSTNAME is defined, the content 1928 of the "hostname" environment variable is passed as 1929 option 12 to the DHCP server. 1930 1931 CONFIG_BOOTP_DHCP_REQUEST_DELAY 1932 1933 A 32bit value in microseconds for a delay between 1934 receiving a "DHCP Offer" and sending the "DHCP Request". 1935 This fixes a problem with certain DHCP servers that don't 1936 respond 100% of the time to a "DHCP request". E.g. On an 1937 AT91RM9200 processor running at 180MHz, this delay needed 1938 to be *at least* 15,000 usec before a Windows Server 2003 1939 DHCP server would reply 100% of the time. I recommend at 1940 least 50,000 usec to be safe. The alternative is to hope 1941 that one of the retries will be successful but note that 1942 the DHCP timeout and retry process takes a longer than 1943 this delay. 1944 1945 - Link-local IP address negotiation: 1946 Negotiate with other link-local clients on the local network 1947 for an address that doesn't require explicit configuration. 1948 This is especially useful if a DHCP server cannot be guaranteed 1949 to exist in all environments that the device must operate. 1950 1951 See doc/README.link-local for more information. 1952 1953 - CDP Options: 1954 CONFIG_CDP_DEVICE_ID 1955 1956 The device id used in CDP trigger frames. 1957 1958 CONFIG_CDP_DEVICE_ID_PREFIX 1959 1960 A two character string which is prefixed to the MAC address 1961 of the device. 1962 1963 CONFIG_CDP_PORT_ID 1964 1965 A printf format string which contains the ascii name of 1966 the port. Normally is set to "eth%d" which sets 1967 eth0 for the first Ethernet, eth1 for the second etc. 1968 1969 CONFIG_CDP_CAPABILITIES 1970 1971 A 32bit integer which indicates the device capabilities; 1972 0x00000010 for a normal host which does not forwards. 1973 1974 CONFIG_CDP_VERSION 1975 1976 An ascii string containing the version of the software. 1977 1978 CONFIG_CDP_PLATFORM 1979 1980 An ascii string containing the name of the platform. 1981 1982 CONFIG_CDP_TRIGGER 1983 1984 A 32bit integer sent on the trigger. 1985 1986 CONFIG_CDP_POWER_CONSUMPTION 1987 1988 A 16bit integer containing the power consumption of the 1989 device in .1 of milliwatts. 1990 1991 CONFIG_CDP_APPLIANCE_VLAN_TYPE 1992 1993 A byte containing the id of the VLAN. 1994 1995- Status LED: CONFIG_LED_STATUS 1996 1997 Several configurations allow to display the current 1998 status using a LED. For instance, the LED will blink 1999 fast while running U-Boot code, stop blinking as 2000 soon as a reply to a BOOTP request was received, and 2001 start blinking slow once the Linux kernel is running 2002 (supported by a status LED driver in the Linux 2003 kernel). Defining CONFIG_LED_STATUS enables this 2004 feature in U-Boot. 2005 2006 Additional options: 2007 2008 CONFIG_LED_STATUS_GPIO 2009 The status LED can be connected to a GPIO pin. 2010 In such cases, the gpio_led driver can be used as a 2011 status LED backend implementation. Define CONFIG_LED_STATUS_GPIO 2012 to include the gpio_led driver in the U-Boot binary. 2013 2014 CONFIG_GPIO_LED_INVERTED_TABLE 2015 Some GPIO connected LEDs may have inverted polarity in which 2016 case the GPIO high value corresponds to LED off state and 2017 GPIO low value corresponds to LED on state. 2018 In such cases CONFIG_GPIO_LED_INVERTED_TABLE may be defined 2019 with a list of GPIO LEDs that have inverted polarity. 2020 2021- CAN Support: CONFIG_CAN_DRIVER 2022 2023 Defining CONFIG_CAN_DRIVER enables CAN driver support 2024 on those systems that support this (optional) 2025 feature, like the TQM8xxL modules. 2026 2027- I2C Support: CONFIG_SYS_I2C 2028 2029 This enable the NEW i2c subsystem, and will allow you to use 2030 i2c commands at the u-boot command line (as long as you set 2031 CONFIG_CMD_I2C in CONFIG_COMMANDS) and communicate with i2c 2032 based realtime clock chips or other i2c devices. See 2033 common/cmd_i2c.c for a description of the command line 2034 interface. 2035 2036 ported i2c driver to the new framework: 2037 - drivers/i2c/soft_i2c.c: 2038 - activate first bus with CONFIG_SYS_I2C_SOFT define 2039 CONFIG_SYS_I2C_SOFT_SPEED and CONFIG_SYS_I2C_SOFT_SLAVE 2040 for defining speed and slave address 2041 - activate second bus with I2C_SOFT_DECLARATIONS2 define 2042 CONFIG_SYS_I2C_SOFT_SPEED_2 and CONFIG_SYS_I2C_SOFT_SLAVE_2 2043 for defining speed and slave address 2044 - activate third bus with I2C_SOFT_DECLARATIONS3 define 2045 CONFIG_SYS_I2C_SOFT_SPEED_3 and CONFIG_SYS_I2C_SOFT_SLAVE_3 2046 for defining speed and slave address 2047 - activate fourth bus with I2C_SOFT_DECLARATIONS4 define 2048 CONFIG_SYS_I2C_SOFT_SPEED_4 and CONFIG_SYS_I2C_SOFT_SLAVE_4 2049 for defining speed and slave address 2050 2051 - drivers/i2c/fsl_i2c.c: 2052 - activate i2c driver with CONFIG_SYS_I2C_FSL 2053 define CONFIG_SYS_FSL_I2C_OFFSET for setting the register 2054 offset CONFIG_SYS_FSL_I2C_SPEED for the i2c speed and 2055 CONFIG_SYS_FSL_I2C_SLAVE for the slave addr of the first 2056 bus. 2057 - If your board supports a second fsl i2c bus, define 2058 CONFIG_SYS_FSL_I2C2_OFFSET for the register offset 2059 CONFIG_SYS_FSL_I2C2_SPEED for the speed and 2060 CONFIG_SYS_FSL_I2C2_SLAVE for the slave address of the 2061 second bus. 2062 2063 - drivers/i2c/tegra_i2c.c: 2064 - activate this driver with CONFIG_SYS_I2C_TEGRA 2065 - This driver adds 4 i2c buses with a fix speed from 2066 100000 and the slave addr 0! 2067 2068 - drivers/i2c/ppc4xx_i2c.c 2069 - activate this driver with CONFIG_SYS_I2C_PPC4XX 2070 - CONFIG_SYS_I2C_PPC4XX_CH0 activate hardware channel 0 2071 - CONFIG_SYS_I2C_PPC4XX_CH1 activate hardware channel 1 2072 2073 - drivers/i2c/i2c_mxc.c 2074 - activate this driver with CONFIG_SYS_I2C_MXC 2075 - enable bus 1 with CONFIG_SYS_I2C_MXC_I2C1 2076 - enable bus 2 with CONFIG_SYS_I2C_MXC_I2C2 2077 - enable bus 3 with CONFIG_SYS_I2C_MXC_I2C3 2078 - enable bus 4 with CONFIG_SYS_I2C_MXC_I2C4 2079 - define speed for bus 1 with CONFIG_SYS_MXC_I2C1_SPEED 2080 - define slave for bus 1 with CONFIG_SYS_MXC_I2C1_SLAVE 2081 - define speed for bus 2 with CONFIG_SYS_MXC_I2C2_SPEED 2082 - define slave for bus 2 with CONFIG_SYS_MXC_I2C2_SLAVE 2083 - define speed for bus 3 with CONFIG_SYS_MXC_I2C3_SPEED 2084 - define slave for bus 3 with CONFIG_SYS_MXC_I2C3_SLAVE 2085 - define speed for bus 4 with CONFIG_SYS_MXC_I2C4_SPEED 2086 - define slave for bus 4 with CONFIG_SYS_MXC_I2C4_SLAVE 2087 If those defines are not set, default value is 100000 2088 for speed, and 0 for slave. 2089 2090 - drivers/i2c/rcar_i2c.c: 2091 - activate this driver with CONFIG_SYS_I2C_RCAR 2092 - This driver adds 4 i2c buses 2093 2094 - CONFIG_SYS_RCAR_I2C0_BASE for setting the register channel 0 2095 - CONFIG_SYS_RCAR_I2C0_SPEED for for the speed channel 0 2096 - CONFIG_SYS_RCAR_I2C1_BASE for setting the register channel 1 2097 - CONFIG_SYS_RCAR_I2C1_SPEED for for the speed channel 1 2098 - CONFIG_SYS_RCAR_I2C2_BASE for setting the register channel 2 2099 - CONFIG_SYS_RCAR_I2C2_SPEED for for the speed channel 2 2100 - CONFIG_SYS_RCAR_I2C3_BASE for setting the register channel 3 2101 - CONFIG_SYS_RCAR_I2C3_SPEED for for the speed channel 3 2102 - CONFIF_SYS_RCAR_I2C_NUM_CONTROLLERS for number of i2c buses 2103 2104 - drivers/i2c/sh_i2c.c: 2105 - activate this driver with CONFIG_SYS_I2C_SH 2106 - This driver adds from 2 to 5 i2c buses 2107 2108 - CONFIG_SYS_I2C_SH_BASE0 for setting the register channel 0 2109 - CONFIG_SYS_I2C_SH_SPEED0 for for the speed channel 0 2110 - CONFIG_SYS_I2C_SH_BASE1 for setting the register channel 1 2111 - CONFIG_SYS_I2C_SH_SPEED1 for for the speed channel 1 2112 - CONFIG_SYS_I2C_SH_BASE2 for setting the register channel 2 2113 - CONFIG_SYS_I2C_SH_SPEED2 for for the speed channel 2 2114 - CONFIG_SYS_I2C_SH_BASE3 for setting the register channel 3 2115 - CONFIG_SYS_I2C_SH_SPEED3 for for the speed channel 3 2116 - CONFIG_SYS_I2C_SH_BASE4 for setting the register channel 4 2117 - CONFIG_SYS_I2C_SH_SPEED4 for for the speed channel 4 2118 - CONFIG_SYS_I2C_SH_NUM_CONTROLLERS for number of i2c buses 2119 2120 - drivers/i2c/omap24xx_i2c.c 2121 - activate this driver with CONFIG_SYS_I2C_OMAP24XX 2122 - CONFIG_SYS_OMAP24_I2C_SPEED speed channel 0 2123 - CONFIG_SYS_OMAP24_I2C_SLAVE slave addr channel 0 2124 - CONFIG_SYS_OMAP24_I2C_SPEED1 speed channel 1 2125 - CONFIG_SYS_OMAP24_I2C_SLAVE1 slave addr channel 1 2126 - CONFIG_SYS_OMAP24_I2C_SPEED2 speed channel 2 2127 - CONFIG_SYS_OMAP24_I2C_SLAVE2 slave addr channel 2 2128 - CONFIG_SYS_OMAP24_I2C_SPEED3 speed channel 3 2129 - CONFIG_SYS_OMAP24_I2C_SLAVE3 slave addr channel 3 2130 - CONFIG_SYS_OMAP24_I2C_SPEED4 speed channel 4 2131 - CONFIG_SYS_OMAP24_I2C_SLAVE4 slave addr channel 4 2132 2133 - drivers/i2c/zynq_i2c.c 2134 - activate this driver with CONFIG_SYS_I2C_ZYNQ 2135 - set CONFIG_SYS_I2C_ZYNQ_SPEED for speed setting 2136 - set CONFIG_SYS_I2C_ZYNQ_SLAVE for slave addr 2137 2138 - drivers/i2c/s3c24x0_i2c.c: 2139 - activate this driver with CONFIG_SYS_I2C_S3C24X0 2140 - This driver adds i2c buses (11 for Exynos5250, Exynos5420 2141 9 i2c buses for Exynos4 and 1 for S3C24X0 SoCs from Samsung) 2142 with a fix speed from 100000 and the slave addr 0! 2143 2144 - drivers/i2c/ihs_i2c.c 2145 - activate this driver with CONFIG_SYS_I2C_IHS 2146 - CONFIG_SYS_I2C_IHS_CH0 activate hardware channel 0 2147 - CONFIG_SYS_I2C_IHS_SPEED_0 speed channel 0 2148 - CONFIG_SYS_I2C_IHS_SLAVE_0 slave addr channel 0 2149 - CONFIG_SYS_I2C_IHS_CH1 activate hardware channel 1 2150 - CONFIG_SYS_I2C_IHS_SPEED_1 speed channel 1 2151 - CONFIG_SYS_I2C_IHS_SLAVE_1 slave addr channel 1 2152 - CONFIG_SYS_I2C_IHS_CH2 activate hardware channel 2 2153 - CONFIG_SYS_I2C_IHS_SPEED_2 speed channel 2 2154 - CONFIG_SYS_I2C_IHS_SLAVE_2 slave addr channel 2 2155 - CONFIG_SYS_I2C_IHS_CH3 activate hardware channel 3 2156 - CONFIG_SYS_I2C_IHS_SPEED_3 speed channel 3 2157 - CONFIG_SYS_I2C_IHS_SLAVE_3 slave addr channel 3 2158 - activate dual channel with CONFIG_SYS_I2C_IHS_DUAL 2159 - CONFIG_SYS_I2C_IHS_SPEED_0_1 speed channel 0_1 2160 - CONFIG_SYS_I2C_IHS_SLAVE_0_1 slave addr channel 0_1 2161 - CONFIG_SYS_I2C_IHS_SPEED_1_1 speed channel 1_1 2162 - CONFIG_SYS_I2C_IHS_SLAVE_1_1 slave addr channel 1_1 2163 - CONFIG_SYS_I2C_IHS_SPEED_2_1 speed channel 2_1 2164 - CONFIG_SYS_I2C_IHS_SLAVE_2_1 slave addr channel 2_1 2165 - CONFIG_SYS_I2C_IHS_SPEED_3_1 speed channel 3_1 2166 - CONFIG_SYS_I2C_IHS_SLAVE_3_1 slave addr channel 3_1 2167 2168 additional defines: 2169 2170 CONFIG_SYS_NUM_I2C_BUSES 2171 Hold the number of i2c buses you want to use. 2172 2173 CONFIG_SYS_I2C_DIRECT_BUS 2174 define this, if you don't use i2c muxes on your hardware. 2175 if CONFIG_SYS_I2C_MAX_HOPS is not defined or == 0 you can 2176 omit this define. 2177 2178 CONFIG_SYS_I2C_MAX_HOPS 2179 define how many muxes are maximal consecutively connected 2180 on one i2c bus. If you not use i2c muxes, omit this 2181 define. 2182 2183 CONFIG_SYS_I2C_BUSES 2184 hold a list of buses you want to use, only used if 2185 CONFIG_SYS_I2C_DIRECT_BUS is not defined, for example 2186 a board with CONFIG_SYS_I2C_MAX_HOPS = 1 and 2187 CONFIG_SYS_NUM_I2C_BUSES = 9: 2188 2189 CONFIG_SYS_I2C_BUSES {{0, {I2C_NULL_HOP}}, \ 2190 {0, {{I2C_MUX_PCA9547, 0x70, 1}}}, \ 2191 {0, {{I2C_MUX_PCA9547, 0x70, 2}}}, \ 2192 {0, {{I2C_MUX_PCA9547, 0x70, 3}}}, \ 2193 {0, {{I2C_MUX_PCA9547, 0x70, 4}}}, \ 2194 {0, {{I2C_MUX_PCA9547, 0x70, 5}}}, \ 2195 {1, {I2C_NULL_HOP}}, \ 2196 {1, {{I2C_MUX_PCA9544, 0x72, 1}}}, \ 2197 {1, {{I2C_MUX_PCA9544, 0x72, 2}}}, \ 2198 } 2199 2200 which defines 2201 bus 0 on adapter 0 without a mux 2202 bus 1 on adapter 0 with a PCA9547 on address 0x70 port 1 2203 bus 2 on adapter 0 with a PCA9547 on address 0x70 port 2 2204 bus 3 on adapter 0 with a PCA9547 on address 0x70 port 3 2205 bus 4 on adapter 0 with a PCA9547 on address 0x70 port 4 2206 bus 5 on adapter 0 with a PCA9547 on address 0x70 port 5 2207 bus 6 on adapter 1 without a mux 2208 bus 7 on adapter 1 with a PCA9544 on address 0x72 port 1 2209 bus 8 on adapter 1 with a PCA9544 on address 0x72 port 2 2210 2211 If you do not have i2c muxes on your board, omit this define. 2212 2213- Legacy I2C Support: CONFIG_HARD_I2C 2214 2215 NOTE: It is intended to move drivers to CONFIG_SYS_I2C which 2216 provides the following compelling advantages: 2217 2218 - more than one i2c adapter is usable 2219 - approved multibus support 2220 - better i2c mux support 2221 2222 ** Please consider updating your I2C driver now. ** 2223 2224 These enable legacy I2C serial bus commands. Defining 2225 CONFIG_HARD_I2C will include the appropriate I2C driver 2226 for the selected CPU. 2227 2228 This will allow you to use i2c commands at the u-boot 2229 command line (as long as you set CONFIG_CMD_I2C in 2230 CONFIG_COMMANDS) and communicate with i2c based realtime 2231 clock chips. See common/cmd_i2c.c for a description of the 2232 command line interface. 2233 2234 CONFIG_HARD_I2C selects a hardware I2C controller. 2235 2236 There are several other quantities that must also be 2237 defined when you define CONFIG_HARD_I2C. 2238 2239 In both cases you will need to define CONFIG_SYS_I2C_SPEED 2240 to be the frequency (in Hz) at which you wish your i2c bus 2241 to run and CONFIG_SYS_I2C_SLAVE to be the address of this node (ie 2242 the CPU's i2c node address). 2243 2244 Now, the u-boot i2c code for the mpc8xx 2245 (arch/powerpc/cpu/mpc8xx/i2c.c) sets the CPU up as a master node 2246 and so its address should therefore be cleared to 0 (See, 2247 eg, MPC823e User's Manual p.16-473). So, set 2248 CONFIG_SYS_I2C_SLAVE to 0. 2249 2250 CONFIG_SYS_I2C_INIT_MPC5XXX 2251 2252 When a board is reset during an i2c bus transfer 2253 chips might think that the current transfer is still 2254 in progress. Reset the slave devices by sending start 2255 commands until the slave device responds. 2256 2257 That's all that's required for CONFIG_HARD_I2C. 2258 2259 If you use the software i2c interface (CONFIG_SYS_I2C_SOFT) 2260 then the following macros need to be defined (examples are 2261 from include/configs/lwmon.h): 2262 2263 I2C_INIT 2264 2265 (Optional). Any commands necessary to enable the I2C 2266 controller or configure ports. 2267 2268 eg: #define I2C_INIT (immr->im_cpm.cp_pbdir |= PB_SCL) 2269 2270 I2C_PORT 2271 2272 (Only for MPC8260 CPU). The I/O port to use (the code 2273 assumes both bits are on the same port). Valid values 2274 are 0..3 for ports A..D. 2275 2276 I2C_ACTIVE 2277 2278 The code necessary to make the I2C data line active 2279 (driven). If the data line is open collector, this 2280 define can be null. 2281 2282 eg: #define I2C_ACTIVE (immr->im_cpm.cp_pbdir |= PB_SDA) 2283 2284 I2C_TRISTATE 2285 2286 The code necessary to make the I2C data line tri-stated 2287 (inactive). If the data line is open collector, this 2288 define can be null. 2289 2290 eg: #define I2C_TRISTATE (immr->im_cpm.cp_pbdir &= ~PB_SDA) 2291 2292 I2C_READ 2293 2294 Code that returns true if the I2C data line is high, 2295 false if it is low. 2296 2297 eg: #define I2C_READ ((immr->im_cpm.cp_pbdat & PB_SDA) != 0) 2298 2299 I2C_SDA(bit) 2300 2301 If <bit> is true, sets the I2C data line high. If it 2302 is false, it clears it (low). 2303 2304 eg: #define I2C_SDA(bit) \ 2305 if(bit) immr->im_cpm.cp_pbdat |= PB_SDA; \ 2306 else immr->im_cpm.cp_pbdat &= ~PB_SDA 2307 2308 I2C_SCL(bit) 2309 2310 If <bit> is true, sets the I2C clock line high. If it 2311 is false, it clears it (low). 2312 2313 eg: #define I2C_SCL(bit) \ 2314 if(bit) immr->im_cpm.cp_pbdat |= PB_SCL; \ 2315 else immr->im_cpm.cp_pbdat &= ~PB_SCL 2316 2317 I2C_DELAY 2318 2319 This delay is invoked four times per clock cycle so this 2320 controls the rate of data transfer. The data rate thus 2321 is 1 / (I2C_DELAY * 4). Often defined to be something 2322 like: 2323 2324 #define I2C_DELAY udelay(2) 2325 2326 CONFIG_SOFT_I2C_GPIO_SCL / CONFIG_SOFT_I2C_GPIO_SDA 2327 2328 If your arch supports the generic GPIO framework (asm/gpio.h), 2329 then you may alternatively define the two GPIOs that are to be 2330 used as SCL / SDA. Any of the previous I2C_xxx macros will 2331 have GPIO-based defaults assigned to them as appropriate. 2332 2333 You should define these to the GPIO value as given directly to 2334 the generic GPIO functions. 2335 2336 CONFIG_SYS_I2C_INIT_BOARD 2337 2338 When a board is reset during an i2c bus transfer 2339 chips might think that the current transfer is still 2340 in progress. On some boards it is possible to access 2341 the i2c SCLK line directly, either by using the 2342 processor pin as a GPIO or by having a second pin 2343 connected to the bus. If this option is defined a 2344 custom i2c_init_board() routine in boards/xxx/board.c 2345 is run early in the boot sequence. 2346 2347 CONFIG_SYS_I2C_BOARD_LATE_INIT 2348 2349 An alternative to CONFIG_SYS_I2C_INIT_BOARD. If this option is 2350 defined a custom i2c_board_late_init() routine in 2351 boards/xxx/board.c is run AFTER the operations in i2c_init() 2352 is completed. This callpoint can be used to unreset i2c bus 2353 using CPU i2c controller register accesses for CPUs whose i2c 2354 controller provide such a method. It is called at the end of 2355 i2c_init() to allow i2c_init operations to setup the i2c bus 2356 controller on the CPU (e.g. setting bus speed & slave address). 2357 2358 CONFIG_I2CFAST (PPC405GP|PPC405EP only) 2359 2360 This option enables configuration of bi_iic_fast[] flags 2361 in u-boot bd_info structure based on u-boot environment 2362 variable "i2cfast". (see also i2cfast) 2363 2364 CONFIG_I2C_MULTI_BUS 2365 2366 This option allows the use of multiple I2C buses, each of which 2367 must have a controller. At any point in time, only one bus is 2368 active. To switch to a different bus, use the 'i2c dev' command. 2369 Note that bus numbering is zero-based. 2370 2371 CONFIG_SYS_I2C_NOPROBES 2372 2373 This option specifies a list of I2C devices that will be skipped 2374 when the 'i2c probe' command is issued. If CONFIG_I2C_MULTI_BUS 2375 is set, specify a list of bus-device pairs. Otherwise, specify 2376 a 1D array of device addresses 2377 2378 e.g. 2379 #undef CONFIG_I2C_MULTI_BUS 2380 #define CONFIG_SYS_I2C_NOPROBES {0x50,0x68} 2381 2382 will skip addresses 0x50 and 0x68 on a board with one I2C bus 2383 2384 #define CONFIG_I2C_MULTI_BUS 2385 #define CONFIG_SYS_I2C_NOPROBES {{0,0x50},{0,0x68},{1,0x54}} 2386 2387 will skip addresses 0x50 and 0x68 on bus 0 and address 0x54 on bus 1 2388 2389 CONFIG_SYS_SPD_BUS_NUM 2390 2391 If defined, then this indicates the I2C bus number for DDR SPD. 2392 If not defined, then U-Boot assumes that SPD is on I2C bus 0. 2393 2394 CONFIG_SYS_RTC_BUS_NUM 2395 2396 If defined, then this indicates the I2C bus number for the RTC. 2397 If not defined, then U-Boot assumes that RTC is on I2C bus 0. 2398 2399 CONFIG_SYS_DTT_BUS_NUM 2400 2401 If defined, then this indicates the I2C bus number for the DTT. 2402 If not defined, then U-Boot assumes that DTT is on I2C bus 0. 2403 2404 CONFIG_SYS_I2C_DTT_ADDR: 2405 2406 If defined, specifies the I2C address of the DTT device. 2407 If not defined, then U-Boot uses predefined value for 2408 specified DTT device. 2409 2410 CONFIG_SOFT_I2C_READ_REPEATED_START 2411 2412 defining this will force the i2c_read() function in 2413 the soft_i2c driver to perform an I2C repeated start 2414 between writing the address pointer and reading the 2415 data. If this define is omitted the default behaviour 2416 of doing a stop-start sequence will be used. Most I2C 2417 devices can use either method, but some require one or 2418 the other. 2419 2420- SPI Support: CONFIG_SPI 2421 2422 Enables SPI driver (so far only tested with 2423 SPI EEPROM, also an instance works with Crystal A/D and 2424 D/As on the SACSng board) 2425 2426 CONFIG_SH_SPI 2427 2428 Enables the driver for SPI controller on SuperH. Currently 2429 only SH7757 is supported. 2430 2431 CONFIG_SOFT_SPI 2432 2433 Enables a software (bit-bang) SPI driver rather than 2434 using hardware support. This is a general purpose 2435 driver that only requires three general I/O port pins 2436 (two outputs, one input) to function. If this is 2437 defined, the board configuration must define several 2438 SPI configuration items (port pins to use, etc). For 2439 an example, see include/configs/sacsng.h. 2440 2441 CONFIG_HARD_SPI 2442 2443 Enables a hardware SPI driver for general-purpose reads 2444 and writes. As with CONFIG_SOFT_SPI, the board configuration 2445 must define a list of chip-select function pointers. 2446 Currently supported on some MPC8xxx processors. For an 2447 example, see include/configs/mpc8349emds.h. 2448 2449 CONFIG_MXC_SPI 2450 2451 Enables the driver for the SPI controllers on i.MX and MXC 2452 SoCs. Currently i.MX31/35/51 are supported. 2453 2454 CONFIG_SYS_SPI_MXC_WAIT 2455 Timeout for waiting until spi transfer completed. 2456 default: (CONFIG_SYS_HZ/100) /* 10 ms */ 2457 2458- FPGA Support: CONFIG_FPGA 2459 2460 Enables FPGA subsystem. 2461 2462 CONFIG_FPGA_<vendor> 2463 2464 Enables support for specific chip vendors. 2465 (ALTERA, XILINX) 2466 2467 CONFIG_FPGA_<family> 2468 2469 Enables support for FPGA family. 2470 (SPARTAN2, SPARTAN3, VIRTEX2, CYCLONE2, ACEX1K, ACEX) 2471 2472 CONFIG_FPGA_COUNT 2473 2474 Specify the number of FPGA devices to support. 2475 2476 CONFIG_CMD_FPGA_LOADMK 2477 2478 Enable support for fpga loadmk command 2479 2480 CONFIG_CMD_FPGA_LOADP 2481 2482 Enable support for fpga loadp command - load partial bitstream 2483 2484 CONFIG_CMD_FPGA_LOADBP 2485 2486 Enable support for fpga loadbp command - load partial bitstream 2487 (Xilinx only) 2488 2489 CONFIG_SYS_FPGA_PROG_FEEDBACK 2490 2491 Enable printing of hash marks during FPGA configuration. 2492 2493 CONFIG_SYS_FPGA_CHECK_BUSY 2494 2495 Enable checks on FPGA configuration interface busy 2496 status by the configuration function. This option 2497 will require a board or device specific function to 2498 be written. 2499 2500 CONFIG_FPGA_DELAY 2501 2502 If defined, a function that provides delays in the FPGA 2503 configuration driver. 2504 2505 CONFIG_SYS_FPGA_CHECK_CTRLC 2506 Allow Control-C to interrupt FPGA configuration 2507 2508 CONFIG_SYS_FPGA_CHECK_ERROR 2509 2510 Check for configuration errors during FPGA bitfile 2511 loading. For example, abort during Virtex II 2512 configuration if the INIT_B line goes low (which 2513 indicated a CRC error). 2514 2515 CONFIG_SYS_FPGA_WAIT_INIT 2516 2517 Maximum time to wait for the INIT_B line to de-assert 2518 after PROB_B has been de-asserted during a Virtex II 2519 FPGA configuration sequence. The default time is 500 2520 ms. 2521 2522 CONFIG_SYS_FPGA_WAIT_BUSY 2523 2524 Maximum time to wait for BUSY to de-assert during 2525 Virtex II FPGA configuration. The default is 5 ms. 2526 2527 CONFIG_SYS_FPGA_WAIT_CONFIG 2528 2529 Time to wait after FPGA configuration. The default is 2530 200 ms. 2531 2532- Configuration Management: 2533 CONFIG_BUILD_TARGET 2534 2535 Some SoCs need special image types (e.g. U-Boot binary 2536 with a special header) as build targets. By defining 2537 CONFIG_BUILD_TARGET in the SoC / board header, this 2538 special image will be automatically built upon calling 2539 make / buildman. 2540 2541 CONFIG_IDENT_STRING 2542 2543 If defined, this string will be added to the U-Boot 2544 version information (U_BOOT_VERSION) 2545 2546- Vendor Parameter Protection: 2547 2548 U-Boot considers the values of the environment 2549 variables "serial#" (Board Serial Number) and 2550 "ethaddr" (Ethernet Address) to be parameters that 2551 are set once by the board vendor / manufacturer, and 2552 protects these variables from casual modification by 2553 the user. Once set, these variables are read-only, 2554 and write or delete attempts are rejected. You can 2555 change this behaviour: 2556 2557 If CONFIG_ENV_OVERWRITE is #defined in your config 2558 file, the write protection for vendor parameters is 2559 completely disabled. Anybody can change or delete 2560 these parameters. 2561 2562 Alternatively, if you define _both_ an ethaddr in the 2563 default env _and_ CONFIG_OVERWRITE_ETHADDR_ONCE, a default 2564 Ethernet address is installed in the environment, 2565 which can be changed exactly ONCE by the user. [The 2566 serial# is unaffected by this, i. e. it remains 2567 read-only.] 2568 2569 The same can be accomplished in a more flexible way 2570 for any variable by configuring the type of access 2571 to allow for those variables in the ".flags" variable 2572 or define CONFIG_ENV_FLAGS_LIST_STATIC. 2573 2574- Protected RAM: 2575 CONFIG_PRAM 2576 2577 Define this variable to enable the reservation of 2578 "protected RAM", i. e. RAM which is not overwritten 2579 by U-Boot. Define CONFIG_PRAM to hold the number of 2580 kB you want to reserve for pRAM. You can overwrite 2581 this default value by defining an environment 2582 variable "pram" to the number of kB you want to 2583 reserve. Note that the board info structure will 2584 still show the full amount of RAM. If pRAM is 2585 reserved, a new environment variable "mem" will 2586 automatically be defined to hold the amount of 2587 remaining RAM in a form that can be passed as boot 2588 argument to Linux, for instance like that: 2589 2590 setenv bootargs ... mem=\${mem} 2591 saveenv 2592 2593 This way you can tell Linux not to use this memory, 2594 either, which results in a memory region that will 2595 not be affected by reboots. 2596 2597 *WARNING* If your board configuration uses automatic 2598 detection of the RAM size, you must make sure that 2599 this memory test is non-destructive. So far, the 2600 following board configurations are known to be 2601 "pRAM-clean": 2602 2603 IVMS8, IVML24, SPD8xx, TQM8xxL, 2604 HERMES, IP860, RPXlite, LWMON, 2605 FLAGADM, TQM8260 2606 2607- Access to physical memory region (> 4GB) 2608 Some basic support is provided for operations on memory not 2609 normally accessible to U-Boot - e.g. some architectures 2610 support access to more than 4GB of memory on 32-bit 2611 machines using physical address extension or similar. 2612 Define CONFIG_PHYSMEM to access this basic support, which 2613 currently only supports clearing the memory. 2614 2615- Error Recovery: 2616 CONFIG_PANIC_HANG 2617 2618 Define this variable to stop the system in case of a 2619 fatal error, so that you have to reset it manually. 2620 This is probably NOT a good idea for an embedded 2621 system where you want the system to reboot 2622 automatically as fast as possible, but it may be 2623 useful during development since you can try to debug 2624 the conditions that lead to the situation. 2625 2626 CONFIG_NET_RETRY_COUNT 2627 2628 This variable defines the number of retries for 2629 network operations like ARP, RARP, TFTP, or BOOTP 2630 before giving up the operation. If not defined, a 2631 default value of 5 is used. 2632 2633 CONFIG_ARP_TIMEOUT 2634 2635 Timeout waiting for an ARP reply in milliseconds. 2636 2637 CONFIG_NFS_TIMEOUT 2638 2639 Timeout in milliseconds used in NFS protocol. 2640 If you encounter "ERROR: Cannot umount" in nfs command, 2641 try longer timeout such as 2642 #define CONFIG_NFS_TIMEOUT 10000UL 2643 2644- Command Interpreter: 2645 CONFIG_AUTO_COMPLETE 2646 2647 Enable auto completion of commands using TAB. 2648 2649 CONFIG_SYS_PROMPT_HUSH_PS2 2650 2651 This defines the secondary prompt string, which is 2652 printed when the command interpreter needs more input 2653 to complete a command. Usually "> ". 2654 2655 Note: 2656 2657 In the current implementation, the local variables 2658 space and global environment variables space are 2659 separated. Local variables are those you define by 2660 simply typing `name=value'. To access a local 2661 variable later on, you have write `$name' or 2662 `${name}'; to execute the contents of a variable 2663 directly type `$name' at the command prompt. 2664 2665 Global environment variables are those you use 2666 setenv/printenv to work with. To run a command stored 2667 in such a variable, you need to use the run command, 2668 and you must not use the '$' sign to access them. 2669 2670 To store commands and special characters in a 2671 variable, please use double quotation marks 2672 surrounding the whole text of the variable, instead 2673 of the backslashes before semicolons and special 2674 symbols. 2675 2676- Command Line Editing and History: 2677 CONFIG_CMDLINE_EDITING 2678 2679 Enable editing and History functions for interactive 2680 command line input operations 2681 2682- Command Line PS1/PS2 support: 2683 CONFIG_CMDLINE_PS_SUPPORT 2684 2685 Enable support for changing the command prompt string 2686 at run-time. Only static string is supported so far. 2687 The string is obtained from environment variables PS1 2688 and PS2. 2689 2690- Default Environment: 2691 CONFIG_EXTRA_ENV_SETTINGS 2692 2693 Define this to contain any number of null terminated 2694 strings (variable = value pairs) that will be part of 2695 the default environment compiled into the boot image. 2696 2697 For example, place something like this in your 2698 board's config file: 2699 2700 #define CONFIG_EXTRA_ENV_SETTINGS \ 2701 "myvar1=value1\0" \ 2702 "myvar2=value2\0" 2703 2704 Warning: This method is based on knowledge about the 2705 internal format how the environment is stored by the 2706 U-Boot code. This is NOT an official, exported 2707 interface! Although it is unlikely that this format 2708 will change soon, there is no guarantee either. 2709 You better know what you are doing here. 2710 2711 Note: overly (ab)use of the default environment is 2712 discouraged. Make sure to check other ways to preset 2713 the environment like the "source" command or the 2714 boot command first. 2715 2716 CONFIG_ENV_VARS_UBOOT_CONFIG 2717 2718 Define this in order to add variables describing the 2719 U-Boot build configuration to the default environment. 2720 These will be named arch, cpu, board, vendor, and soc. 2721 2722 Enabling this option will cause the following to be defined: 2723 2724 - CONFIG_SYS_ARCH 2725 - CONFIG_SYS_CPU 2726 - CONFIG_SYS_BOARD 2727 - CONFIG_SYS_VENDOR 2728 - CONFIG_SYS_SOC 2729 2730 CONFIG_ENV_VARS_UBOOT_RUNTIME_CONFIG 2731 2732 Define this in order to add variables describing certain 2733 run-time determined information about the hardware to the 2734 environment. These will be named board_name, board_rev. 2735 2736 CONFIG_DELAY_ENVIRONMENT 2737 2738 Normally the environment is loaded when the board is 2739 initialised so that it is available to U-Boot. This inhibits 2740 that so that the environment is not available until 2741 explicitly loaded later by U-Boot code. With CONFIG_OF_CONTROL 2742 this is instead controlled by the value of 2743 /config/load-environment. 2744 2745- DataFlash Support: 2746 CONFIG_HAS_DATAFLASH 2747 2748 Defining this option enables DataFlash features and 2749 allows to read/write in Dataflash via the standard 2750 commands cp, md... 2751 2752- Serial Flash support 2753 CONFIG_CMD_SF 2754 2755 Defining this option enables SPI flash commands 2756 'sf probe/read/write/erase/update'. 2757 2758 Usage requires an initial 'probe' to define the serial 2759 flash parameters, followed by read/write/erase/update 2760 commands. 2761 2762 The following defaults may be provided by the platform 2763 to handle the common case when only a single serial 2764 flash is present on the system. 2765 2766 CONFIG_SF_DEFAULT_BUS Bus identifier 2767 CONFIG_SF_DEFAULT_CS Chip-select 2768 CONFIG_SF_DEFAULT_MODE (see include/spi.h) 2769 CONFIG_SF_DEFAULT_SPEED in Hz 2770 2771 CONFIG_CMD_SF_TEST 2772 2773 Define this option to include a destructive SPI flash 2774 test ('sf test'). 2775 2776 CONFIG_SF_DUAL_FLASH Dual flash memories 2777 2778 Define this option to use dual flash support where two flash 2779 memories can be connected with a given cs line. 2780 Currently Xilinx Zynq qspi supports these type of connections. 2781 2782- SystemACE Support: 2783 CONFIG_SYSTEMACE 2784 2785 Adding this option adds support for Xilinx SystemACE 2786 chips attached via some sort of local bus. The address 2787 of the chip must also be defined in the 2788 CONFIG_SYS_SYSTEMACE_BASE macro. For example: 2789 2790 #define CONFIG_SYSTEMACE 2791 #define CONFIG_SYS_SYSTEMACE_BASE 0xf0000000 2792 2793 When SystemACE support is added, the "ace" device type 2794 becomes available to the fat commands, i.e. fatls. 2795 2796- TFTP Fixed UDP Port: 2797 CONFIG_TFTP_PORT 2798 2799 If this is defined, the environment variable tftpsrcp 2800 is used to supply the TFTP UDP source port value. 2801 If tftpsrcp isn't defined, the normal pseudo-random port 2802 number generator is used. 2803 2804 Also, the environment variable tftpdstp is used to supply 2805 the TFTP UDP destination port value. If tftpdstp isn't 2806 defined, the normal port 69 is used. 2807 2808 The purpose for tftpsrcp is to allow a TFTP server to 2809 blindly start the TFTP transfer using the pre-configured 2810 target IP address and UDP port. This has the effect of 2811 "punching through" the (Windows XP) firewall, allowing 2812 the remainder of the TFTP transfer to proceed normally. 2813 A better solution is to properly configure the firewall, 2814 but sometimes that is not allowed. 2815 2816- Hashing support: 2817 CONFIG_CMD_HASH 2818 2819 This enables a generic 'hash' command which can produce 2820 hashes / digests from a few algorithms (e.g. SHA1, SHA256). 2821 2822 CONFIG_HASH_VERIFY 2823 2824 Enable the hash verify command (hash -v). This adds to code 2825 size a little. 2826 2827 CONFIG_SHA1 - This option enables support of hashing using SHA1 2828 algorithm. The hash is calculated in software. 2829 CONFIG_SHA256 - This option enables support of hashing using 2830 SHA256 algorithm. The hash is calculated in software. 2831 CONFIG_SHA_HW_ACCEL - This option enables hardware acceleration 2832 for SHA1/SHA256 hashing. 2833 This affects the 'hash' command and also the 2834 hash_lookup_algo() function. 2835 CONFIG_SHA_PROG_HW_ACCEL - This option enables 2836 hardware-acceleration for SHA1/SHA256 progressive hashing. 2837 Data can be streamed in a block at a time and the hashing 2838 is performed in hardware. 2839 2840 Note: There is also a sha1sum command, which should perhaps 2841 be deprecated in favour of 'hash sha1'. 2842 2843- Freescale i.MX specific commands: 2844 CONFIG_CMD_HDMIDETECT 2845 This enables 'hdmidet' command which returns true if an 2846 HDMI monitor is detected. This command is i.MX 6 specific. 2847 2848- bootcount support: 2849 CONFIG_BOOTCOUNT_LIMIT 2850 2851 This enables the bootcounter support, see: 2852 http://www.denx.de/wiki/DULG/UBootBootCountLimit 2853 2854 CONFIG_AT91SAM9XE 2855 enable special bootcounter support on at91sam9xe based boards. 2856 CONFIG_SOC_DA8XX 2857 enable special bootcounter support on da850 based boards. 2858 CONFIG_BOOTCOUNT_RAM 2859 enable support for the bootcounter in RAM 2860 CONFIG_BOOTCOUNT_I2C 2861 enable support for the bootcounter on an i2c (like RTC) device. 2862 CONFIG_SYS_I2C_RTC_ADDR = i2c chip address 2863 CONFIG_SYS_BOOTCOUNT_ADDR = i2c addr which is used for 2864 the bootcounter. 2865 CONFIG_BOOTCOUNT_ALEN = address len 2866 2867- Show boot progress: 2868 CONFIG_SHOW_BOOT_PROGRESS 2869 2870 Defining this option allows to add some board- 2871 specific code (calling a user-provided function 2872 "show_boot_progress(int)") that enables you to show 2873 the system's boot progress on some display (for 2874 example, some LED's) on your board. At the moment, 2875 the following checkpoints are implemented: 2876 2877 2878Legacy uImage format: 2879 2880 Arg Where When 2881 1 common/cmd_bootm.c before attempting to boot an image 2882 -1 common/cmd_bootm.c Image header has bad magic number 2883 2 common/cmd_bootm.c Image header has correct magic number 2884 -2 common/cmd_bootm.c Image header has bad checksum 2885 3 common/cmd_bootm.c Image header has correct checksum 2886 -3 common/cmd_bootm.c Image data has bad checksum 2887 4 common/cmd_bootm.c Image data has correct checksum 2888 -4 common/cmd_bootm.c Image is for unsupported architecture 2889 5 common/cmd_bootm.c Architecture check OK 2890 -5 common/cmd_bootm.c Wrong Image Type (not kernel, multi) 2891 6 common/cmd_bootm.c Image Type check OK 2892 -6 common/cmd_bootm.c gunzip uncompression error 2893 -7 common/cmd_bootm.c Unimplemented compression type 2894 7 common/cmd_bootm.c Uncompression OK 2895 8 common/cmd_bootm.c No uncompress/copy overwrite error 2896 -9 common/cmd_bootm.c Unsupported OS (not Linux, BSD, VxWorks, QNX) 2897 2898 9 common/image.c Start initial ramdisk verification 2899 -10 common/image.c Ramdisk header has bad magic number 2900 -11 common/image.c Ramdisk header has bad checksum 2901 10 common/image.c Ramdisk header is OK 2902 -12 common/image.c Ramdisk data has bad checksum 2903 11 common/image.c Ramdisk data has correct checksum 2904 12 common/image.c Ramdisk verification complete, start loading 2905 -13 common/image.c Wrong Image Type (not PPC Linux ramdisk) 2906 13 common/image.c Start multifile image verification 2907 14 common/image.c No initial ramdisk, no multifile, continue. 2908 2909 15 arch/<arch>/lib/bootm.c All preparation done, transferring control to OS 2910 2911 -30 arch/powerpc/lib/board.c Fatal error, hang the system 2912 -31 post/post.c POST test failed, detected by post_output_backlog() 2913 -32 post/post.c POST test failed, detected by post_run_single() 2914 2915 34 common/cmd_doc.c before loading a Image from a DOC device 2916 -35 common/cmd_doc.c Bad usage of "doc" command 2917 35 common/cmd_doc.c correct usage of "doc" command 2918 -36 common/cmd_doc.c No boot device 2919 36 common/cmd_doc.c correct boot device 2920 -37 common/cmd_doc.c Unknown Chip ID on boot device 2921 37 common/cmd_doc.c correct chip ID found, device available 2922 -38 common/cmd_doc.c Read Error on boot device 2923 38 common/cmd_doc.c reading Image header from DOC device OK 2924 -39 common/cmd_doc.c Image header has bad magic number 2925 39 common/cmd_doc.c Image header has correct magic number 2926 -40 common/cmd_doc.c Error reading Image from DOC device 2927 40 common/cmd_doc.c Image header has correct magic number 2928 41 common/cmd_ide.c before loading a Image from a IDE device 2929 -42 common/cmd_ide.c Bad usage of "ide" command 2930 42 common/cmd_ide.c correct usage of "ide" command 2931 -43 common/cmd_ide.c No boot device 2932 43 common/cmd_ide.c boot device found 2933 -44 common/cmd_ide.c Device not available 2934 44 common/cmd_ide.c Device available 2935 -45 common/cmd_ide.c wrong partition selected 2936 45 common/cmd_ide.c partition selected 2937 -46 common/cmd_ide.c Unknown partition table 2938 46 common/cmd_ide.c valid partition table found 2939 -47 common/cmd_ide.c Invalid partition type 2940 47 common/cmd_ide.c correct partition type 2941 -48 common/cmd_ide.c Error reading Image Header on boot device 2942 48 common/cmd_ide.c reading Image Header from IDE device OK 2943 -49 common/cmd_ide.c Image header has bad magic number 2944 49 common/cmd_ide.c Image header has correct magic number 2945 -50 common/cmd_ide.c Image header has bad checksum 2946 50 common/cmd_ide.c Image header has correct checksum 2947 -51 common/cmd_ide.c Error reading Image from IDE device 2948 51 common/cmd_ide.c reading Image from IDE device OK 2949 52 common/cmd_nand.c before loading a Image from a NAND device 2950 -53 common/cmd_nand.c Bad usage of "nand" command 2951 53 common/cmd_nand.c correct usage of "nand" command 2952 -54 common/cmd_nand.c No boot device 2953 54 common/cmd_nand.c boot device found 2954 -55 common/cmd_nand.c Unknown Chip ID on boot device 2955 55 common/cmd_nand.c correct chip ID found, device available 2956 -56 common/cmd_nand.c Error reading Image Header on boot device 2957 56 common/cmd_nand.c reading Image Header from NAND device OK 2958 -57 common/cmd_nand.c Image header has bad magic number 2959 57 common/cmd_nand.c Image header has correct magic number 2960 -58 common/cmd_nand.c Error reading Image from NAND device 2961 58 common/cmd_nand.c reading Image from NAND device OK 2962 2963 -60 common/env_common.c Environment has a bad CRC, using default 2964 2965 64 net/eth.c starting with Ethernet configuration. 2966 -64 net/eth.c no Ethernet found. 2967 65 net/eth.c Ethernet found. 2968 2969 -80 common/cmd_net.c usage wrong 2970 80 common/cmd_net.c before calling net_loop() 2971 -81 common/cmd_net.c some error in net_loop() occurred 2972 81 common/cmd_net.c net_loop() back without error 2973 -82 common/cmd_net.c size == 0 (File with size 0 loaded) 2974 82 common/cmd_net.c trying automatic boot 2975 83 common/cmd_net.c running "source" command 2976 -83 common/cmd_net.c some error in automatic boot or "source" command 2977 84 common/cmd_net.c end without errors 2978 2979FIT uImage format: 2980 2981 Arg Where When 2982 100 common/cmd_bootm.c Kernel FIT Image has correct format 2983 -100 common/cmd_bootm.c Kernel FIT Image has incorrect format 2984 101 common/cmd_bootm.c No Kernel subimage unit name, using configuration 2985 -101 common/cmd_bootm.c Can't get configuration for kernel subimage 2986 102 common/cmd_bootm.c Kernel unit name specified 2987 -103 common/cmd_bootm.c Can't get kernel subimage node offset 2988 103 common/cmd_bootm.c Found configuration node 2989 104 common/cmd_bootm.c Got kernel subimage node offset 2990 -104 common/cmd_bootm.c Kernel subimage hash verification failed 2991 105 common/cmd_bootm.c Kernel subimage hash verification OK 2992 -105 common/cmd_bootm.c Kernel subimage is for unsupported architecture 2993 106 common/cmd_bootm.c Architecture check OK 2994 -106 common/cmd_bootm.c Kernel subimage has wrong type 2995 107 common/cmd_bootm.c Kernel subimage type OK 2996 -107 common/cmd_bootm.c Can't get kernel subimage data/size 2997 108 common/cmd_bootm.c Got kernel subimage data/size 2998 -108 common/cmd_bootm.c Wrong image type (not legacy, FIT) 2999 -109 common/cmd_bootm.c Can't get kernel subimage type 3000 -110 common/cmd_bootm.c Can't get kernel subimage comp 3001 -111 common/cmd_bootm.c Can't get kernel subimage os 3002 -112 common/cmd_bootm.c Can't get kernel subimage load address 3003 -113 common/cmd_bootm.c Image uncompress/copy overwrite error 3004 3005 120 common/image.c Start initial ramdisk verification 3006 -120 common/image.c Ramdisk FIT image has incorrect format 3007 121 common/image.c Ramdisk FIT image has correct format 3008 122 common/image.c No ramdisk subimage unit name, using configuration 3009 -122 common/image.c Can't get configuration for ramdisk subimage 3010 123 common/image.c Ramdisk unit name specified 3011 -124 common/image.c Can't get ramdisk subimage node offset 3012 125 common/image.c Got ramdisk subimage node offset 3013 -125 common/image.c Ramdisk subimage hash verification failed 3014 126 common/image.c Ramdisk subimage hash verification OK 3015 -126 common/image.c Ramdisk subimage for unsupported architecture 3016 127 common/image.c Architecture check OK 3017 -127 common/image.c Can't get ramdisk subimage data/size 3018 128 common/image.c Got ramdisk subimage data/size 3019 129 common/image.c Can't get ramdisk load address 3020 -129 common/image.c Got ramdisk load address 3021 3022 -130 common/cmd_doc.c Incorrect FIT image format 3023 131 common/cmd_doc.c FIT image format OK 3024 3025 -140 common/cmd_ide.c Incorrect FIT image format 3026 141 common/cmd_ide.c FIT image format OK 3027 3028 -150 common/cmd_nand.c Incorrect FIT image format 3029 151 common/cmd_nand.c FIT image format OK 3030 3031- legacy image format: 3032 CONFIG_IMAGE_FORMAT_LEGACY 3033 enables the legacy image format support in U-Boot. 3034 3035 Default: 3036 enabled if CONFIG_FIT_SIGNATURE is not defined. 3037 3038 CONFIG_DISABLE_IMAGE_LEGACY 3039 disable the legacy image format 3040 3041 This define is introduced, as the legacy image format is 3042 enabled per default for backward compatibility. 3043 3044- FIT image support: 3045 CONFIG_FIT_DISABLE_SHA256 3046 Supporting SHA256 hashes has quite an impact on binary size. 3047 For constrained systems sha256 hash support can be disabled 3048 with this option. 3049 3050 TODO(sjg@chromium.org): Adjust this option to be positive, 3051 and move it to Kconfig 3052 3053- Standalone program support: 3054 CONFIG_STANDALONE_LOAD_ADDR 3055 3056 This option defines a board specific value for the 3057 address where standalone program gets loaded, thus 3058 overwriting the architecture dependent default 3059 settings. 3060 3061- Frame Buffer Address: 3062 CONFIG_FB_ADDR 3063 3064 Define CONFIG_FB_ADDR if you want to use specific 3065 address for frame buffer. This is typically the case 3066 when using a graphics controller has separate video 3067 memory. U-Boot will then place the frame buffer at 3068 the given address instead of dynamically reserving it 3069 in system RAM by calling lcd_setmem(), which grabs 3070 the memory for the frame buffer depending on the 3071 configured panel size. 3072 3073 Please see board_init_f function. 3074 3075- Automatic software updates via TFTP server 3076 CONFIG_UPDATE_TFTP 3077 CONFIG_UPDATE_TFTP_CNT_MAX 3078 CONFIG_UPDATE_TFTP_MSEC_MAX 3079 3080 These options enable and control the auto-update feature; 3081 for a more detailed description refer to doc/README.update. 3082 3083- MTD Support (mtdparts command, UBI support) 3084 CONFIG_MTD_DEVICE 3085 3086 Adds the MTD device infrastructure from the Linux kernel. 3087 Needed for mtdparts command support. 3088 3089 CONFIG_MTD_PARTITIONS 3090 3091 Adds the MTD partitioning infrastructure from the Linux 3092 kernel. Needed for UBI support. 3093 3094- UBI support 3095 CONFIG_CMD_UBI 3096 3097 Adds commands for interacting with MTD partitions formatted 3098 with the UBI flash translation layer 3099 3100 Requires also defining CONFIG_RBTREE 3101 3102 CONFIG_UBI_SILENCE_MSG 3103 3104 Make the verbose messages from UBI stop printing. This leaves 3105 warnings and errors enabled. 3106 3107 3108 CONFIG_MTD_UBI_WL_THRESHOLD 3109 This parameter defines the maximum difference between the highest 3110 erase counter value and the lowest erase counter value of eraseblocks 3111 of UBI devices. When this threshold is exceeded, UBI starts performing 3112 wear leveling by means of moving data from eraseblock with low erase 3113 counter to eraseblocks with high erase counter. 3114 3115 The default value should be OK for SLC NAND flashes, NOR flashes and 3116 other flashes which have eraseblock life-cycle 100000 or more. 3117 However, in case of MLC NAND flashes which typically have eraseblock 3118 life-cycle less than 10000, the threshold should be lessened (e.g., 3119 to 128 or 256, although it does not have to be power of 2). 3120 3121 default: 4096 3122 3123 CONFIG_MTD_UBI_BEB_LIMIT 3124 This option specifies the maximum bad physical eraseblocks UBI 3125 expects on the MTD device (per 1024 eraseblocks). If the 3126 underlying flash does not admit of bad eraseblocks (e.g. NOR 3127 flash), this value is ignored. 3128 3129 NAND datasheets often specify the minimum and maximum NVM 3130 (Number of Valid Blocks) for the flashes' endurance lifetime. 3131 The maximum expected bad eraseblocks per 1024 eraseblocks 3132 then can be calculated as "1024 * (1 - MinNVB / MaxNVB)", 3133 which gives 20 for most NANDs (MaxNVB is basically the total 3134 count of eraseblocks on the chip). 3135 3136 To put it differently, if this value is 20, UBI will try to 3137 reserve about 1.9% of physical eraseblocks for bad blocks 3138 handling. And that will be 1.9% of eraseblocks on the entire 3139 NAND chip, not just the MTD partition UBI attaches. This means 3140 that if you have, say, a NAND flash chip admits maximum 40 bad 3141 eraseblocks, and it is split on two MTD partitions of the same 3142 size, UBI will reserve 40 eraseblocks when attaching a 3143 partition. 3144 3145 default: 20 3146 3147 CONFIG_MTD_UBI_FASTMAP 3148 Fastmap is a mechanism which allows attaching an UBI device 3149 in nearly constant time. Instead of scanning the whole MTD device it 3150 only has to locate a checkpoint (called fastmap) on the device. 3151 The on-flash fastmap contains all information needed to attach 3152 the device. Using fastmap makes only sense on large devices where 3153 attaching by scanning takes long. UBI will not automatically install 3154 a fastmap on old images, but you can set the UBI parameter 3155 CONFIG_MTD_UBI_FASTMAP_AUTOCONVERT to 1 if you want so. Please note 3156 that fastmap-enabled images are still usable with UBI implementations 3157 without fastmap support. On typical flash devices the whole fastmap 3158 fits into one PEB. UBI will reserve PEBs to hold two fastmaps. 3159 3160 CONFIG_MTD_UBI_FASTMAP_AUTOCONVERT 3161 Set this parameter to enable fastmap automatically on images 3162 without a fastmap. 3163 default: 0 3164 3165 CONFIG_MTD_UBI_FM_DEBUG 3166 Enable UBI fastmap debug 3167 default: 0 3168 3169- UBIFS support 3170 CONFIG_CMD_UBIFS 3171 3172 Adds commands for interacting with UBI volumes formatted as 3173 UBIFS. UBIFS is read-only in u-boot. 3174 3175 Requires UBI support as well as CONFIG_LZO 3176 3177 CONFIG_UBIFS_SILENCE_MSG 3178 3179 Make the verbose messages from UBIFS stop printing. This leaves 3180 warnings and errors enabled. 3181 3182- SPL framework 3183 CONFIG_SPL 3184 Enable building of SPL globally. 3185 3186 CONFIG_SPL_LDSCRIPT 3187 LDSCRIPT for linking the SPL binary. 3188 3189 CONFIG_SPL_MAX_FOOTPRINT 3190 Maximum size in memory allocated to the SPL, BSS included. 3191 When defined, the linker checks that the actual memory 3192 used by SPL from _start to __bss_end does not exceed it. 3193 CONFIG_SPL_MAX_FOOTPRINT and CONFIG_SPL_BSS_MAX_SIZE 3194 must not be both defined at the same time. 3195 3196 CONFIG_SPL_MAX_SIZE 3197 Maximum size of the SPL image (text, data, rodata, and 3198 linker lists sections), BSS excluded. 3199 When defined, the linker checks that the actual size does 3200 not exceed it. 3201 3202 CONFIG_SPL_TEXT_BASE 3203 TEXT_BASE for linking the SPL binary. 3204 3205 CONFIG_SPL_RELOC_TEXT_BASE 3206 Address to relocate to. If unspecified, this is equal to 3207 CONFIG_SPL_TEXT_BASE (i.e. no relocation is done). 3208 3209 CONFIG_SPL_BSS_START_ADDR 3210 Link address for the BSS within the SPL binary. 3211 3212 CONFIG_SPL_BSS_MAX_SIZE 3213 Maximum size in memory allocated to the SPL BSS. 3214 When defined, the linker checks that the actual memory used 3215 by SPL from __bss_start to __bss_end does not exceed it. 3216 CONFIG_SPL_MAX_FOOTPRINT and CONFIG_SPL_BSS_MAX_SIZE 3217 must not be both defined at the same time. 3218 3219 CONFIG_SPL_STACK 3220 Adress of the start of the stack SPL will use 3221 3222 CONFIG_SPL_PANIC_ON_RAW_IMAGE 3223 When defined, SPL will panic() if the image it has 3224 loaded does not have a signature. 3225 Defining this is useful when code which loads images 3226 in SPL cannot guarantee that absolutely all read errors 3227 will be caught. 3228 An example is the LPC32XX MLC NAND driver, which will 3229 consider that a completely unreadable NAND block is bad, 3230 and thus should be skipped silently. 3231 3232 CONFIG_SPL_RELOC_STACK 3233 Adress of the start of the stack SPL will use after 3234 relocation. If unspecified, this is equal to 3235 CONFIG_SPL_STACK. 3236 3237 CONFIG_SYS_SPL_MALLOC_START 3238 Starting address of the malloc pool used in SPL. 3239 When this option is set the full malloc is used in SPL and 3240 it is set up by spl_init() and before that, the simple malloc() 3241 can be used if CONFIG_SYS_MALLOC_F is defined. 3242 3243 CONFIG_SYS_SPL_MALLOC_SIZE 3244 The size of the malloc pool used in SPL. 3245 3246 CONFIG_SPL_FRAMEWORK 3247 Enable the SPL framework under common/. This framework 3248 supports MMC, NAND and YMODEM loading of U-Boot and NAND 3249 NAND loading of the Linux Kernel. 3250 3251 CONFIG_SPL_OS_BOOT 3252 Enable booting directly to an OS from SPL. 3253 See also: doc/README.falcon 3254 3255 CONFIG_SPL_DISPLAY_PRINT 3256 For ARM, enable an optional function to print more information 3257 about the running system. 3258 3259 CONFIG_SPL_INIT_MINIMAL 3260 Arch init code should be built for a very small image 3261 3262 CONFIG_SYS_MMCSD_RAW_MODE_U_BOOT_PARTITION 3263 Partition on the MMC to load U-Boot from when the MMC is being 3264 used in raw mode 3265 3266 CONFIG_SYS_MMCSD_RAW_MODE_KERNEL_SECTOR 3267 Sector to load kernel uImage from when MMC is being 3268 used in raw mode (for Falcon mode) 3269 3270 CONFIG_SYS_MMCSD_RAW_MODE_ARGS_SECTOR, 3271 CONFIG_SYS_MMCSD_RAW_MODE_ARGS_SECTORS 3272 Sector and number of sectors to load kernel argument 3273 parameters from when MMC is being used in raw mode 3274 (for falcon mode) 3275 3276 CONFIG_SYS_MMCSD_FS_BOOT_PARTITION 3277 Partition on the MMC to load U-Boot from when the MMC is being 3278 used in fs mode 3279 3280 CONFIG_SPL_FS_LOAD_PAYLOAD_NAME 3281 Filename to read to load U-Boot when reading from filesystem 3282 3283 CONFIG_SPL_FS_LOAD_KERNEL_NAME 3284 Filename to read to load kernel uImage when reading 3285 from filesystem (for Falcon mode) 3286 3287 CONFIG_SPL_FS_LOAD_ARGS_NAME 3288 Filename to read to load kernel argument parameters 3289 when reading from filesystem (for Falcon mode) 3290 3291 CONFIG_SPL_MPC83XX_WAIT_FOR_NAND 3292 Set this for NAND SPL on PPC mpc83xx targets, so that 3293 start.S waits for the rest of the SPL to load before 3294 continuing (the hardware starts execution after just 3295 loading the first page rather than the full 4K). 3296 3297 CONFIG_SPL_SKIP_RELOCATE 3298 Avoid SPL relocation 3299 3300 CONFIG_SPL_NAND_BASE 3301 Include nand_base.c in the SPL. Requires 3302 CONFIG_SPL_NAND_DRIVERS. 3303 3304 CONFIG_SPL_NAND_DRIVERS 3305 SPL uses normal NAND drivers, not minimal drivers. 3306 3307 CONFIG_SPL_NAND_ECC 3308 Include standard software ECC in the SPL 3309 3310 CONFIG_SPL_NAND_SIMPLE 3311 Support for NAND boot using simple NAND drivers that 3312 expose the cmd_ctrl() interface. 3313 3314 CONFIG_SPL_UBI 3315 Support for a lightweight UBI (fastmap) scanner and 3316 loader 3317 3318 CONFIG_SPL_NAND_RAW_ONLY 3319 Support to boot only raw u-boot.bin images. Use this only 3320 if you need to save space. 3321 3322 CONFIG_SPL_COMMON_INIT_DDR 3323 Set for common ddr init with serial presence detect in 3324 SPL binary. 3325 3326 CONFIG_SYS_NAND_5_ADDR_CYCLE, CONFIG_SYS_NAND_PAGE_COUNT, 3327 CONFIG_SYS_NAND_PAGE_SIZE, CONFIG_SYS_NAND_OOBSIZE, 3328 CONFIG_SYS_NAND_BLOCK_SIZE, CONFIG_SYS_NAND_BAD_BLOCK_POS, 3329 CONFIG_SYS_NAND_ECCPOS, CONFIG_SYS_NAND_ECCSIZE, 3330 CONFIG_SYS_NAND_ECCBYTES 3331 Defines the size and behavior of the NAND that SPL uses 3332 to read U-Boot 3333 3334 CONFIG_SPL_NAND_BOOT 3335 Add support NAND boot 3336 3337 CONFIG_SYS_NAND_U_BOOT_OFFS 3338 Location in NAND to read U-Boot from 3339 3340 CONFIG_SYS_NAND_U_BOOT_DST 3341 Location in memory to load U-Boot to 3342 3343 CONFIG_SYS_NAND_U_BOOT_SIZE 3344 Size of image to load 3345 3346 CONFIG_SYS_NAND_U_BOOT_START 3347 Entry point in loaded image to jump to 3348 3349 CONFIG_SYS_NAND_HW_ECC_OOBFIRST 3350 Define this if you need to first read the OOB and then the 3351 data. This is used, for example, on davinci platforms. 3352 3353 CONFIG_SPL_OMAP3_ID_NAND 3354 Support for an OMAP3-specific set of functions to return the 3355 ID and MFR of the first attached NAND chip, if present. 3356 3357 CONFIG_SPL_RAM_DEVICE 3358 Support for running image already present in ram, in SPL binary 3359 3360 CONFIG_SPL_PAD_TO 3361 Image offset to which the SPL should be padded before appending 3362 the SPL payload. By default, this is defined as 3363 CONFIG_SPL_MAX_SIZE, or 0 if CONFIG_SPL_MAX_SIZE is undefined. 3364 CONFIG_SPL_PAD_TO must be either 0, meaning to append the SPL 3365 payload without any padding, or >= CONFIG_SPL_MAX_SIZE. 3366 3367 CONFIG_SPL_TARGET 3368 Final target image containing SPL and payload. Some SPLs 3369 use an arch-specific makefile fragment instead, for 3370 example if more than one image needs to be produced. 3371 3372 CONFIG_FIT_SPL_PRINT 3373 Printing information about a FIT image adds quite a bit of 3374 code to SPL. So this is normally disabled in SPL. Use this 3375 option to re-enable it. This will affect the output of the 3376 bootm command when booting a FIT image. 3377 3378- TPL framework 3379 CONFIG_TPL 3380 Enable building of TPL globally. 3381 3382 CONFIG_TPL_PAD_TO 3383 Image offset to which the TPL should be padded before appending 3384 the TPL payload. By default, this is defined as 3385 CONFIG_SPL_MAX_SIZE, or 0 if CONFIG_SPL_MAX_SIZE is undefined. 3386 CONFIG_SPL_PAD_TO must be either 0, meaning to append the SPL 3387 payload without any padding, or >= CONFIG_SPL_MAX_SIZE. 3388 3389- Interrupt support (PPC): 3390 3391 There are common interrupt_init() and timer_interrupt() 3392 for all PPC archs. interrupt_init() calls interrupt_init_cpu() 3393 for CPU specific initialization. interrupt_init_cpu() 3394 should set decrementer_count to appropriate value. If 3395 CPU resets decrementer automatically after interrupt 3396 (ppc4xx) it should set decrementer_count to zero. 3397 timer_interrupt() calls timer_interrupt_cpu() for CPU 3398 specific handling. If board has watchdog / status_led 3399 / other_activity_monitor it works automatically from 3400 general timer_interrupt(). 3401 3402 3403Board initialization settings: 3404------------------------------ 3405 3406During Initialization u-boot calls a number of board specific functions 3407to allow the preparation of board specific prerequisites, e.g. pin setup 3408before drivers are initialized. To enable these callbacks the 3409following configuration macros have to be defined. Currently this is 3410architecture specific, so please check arch/your_architecture/lib/board.c 3411typically in board_init_f() and board_init_r(). 3412 3413- CONFIG_BOARD_EARLY_INIT_F: Call board_early_init_f() 3414- CONFIG_BOARD_EARLY_INIT_R: Call board_early_init_r() 3415- CONFIG_BOARD_LATE_INIT: Call board_late_init() 3416- CONFIG_BOARD_POSTCLK_INIT: Call board_postclk_init() 3417 3418Configuration Settings: 3419----------------------- 3420 3421- CONFIG_SYS_SUPPORT_64BIT_DATA: Defined automatically if compiled as 64-bit. 3422 Optionally it can be defined to support 64-bit memory commands. 3423 3424- CONFIG_SYS_LONGHELP: Defined when you want long help messages included; 3425 undefine this when you're short of memory. 3426 3427- CONFIG_SYS_HELP_CMD_WIDTH: Defined when you want to override the default 3428 width of the commands listed in the 'help' command output. 3429 3430- CONFIG_SYS_PROMPT: This is what U-Boot prints on the console to 3431 prompt for user input. 3432 3433- CONFIG_SYS_CBSIZE: Buffer size for input from the Console 3434 3435- CONFIG_SYS_PBSIZE: Buffer size for Console output 3436 3437- CONFIG_SYS_MAXARGS: max. Number of arguments accepted for monitor commands 3438 3439- CONFIG_SYS_BARGSIZE: Buffer size for Boot Arguments which are passed to 3440 the application (usually a Linux kernel) when it is 3441 booted 3442 3443- CONFIG_SYS_BAUDRATE_TABLE: 3444 List of legal baudrate settings for this board. 3445 3446- CONFIG_SYS_MEMTEST_START, CONFIG_SYS_MEMTEST_END: 3447 Begin and End addresses of the area used by the 3448 simple memory test. 3449 3450- CONFIG_SYS_ALT_MEMTEST: 3451 Enable an alternate, more extensive memory test. 3452 3453- CONFIG_SYS_MEMTEST_SCRATCH: 3454 Scratch address used by the alternate memory test 3455 You only need to set this if address zero isn't writeable 3456 3457- CONFIG_SYS_MEM_RESERVE_SECURE 3458 Only implemented for ARMv8 for now. 3459 If defined, the size of CONFIG_SYS_MEM_RESERVE_SECURE memory 3460 is substracted from total RAM and won't be reported to OS. 3461 This memory can be used as secure memory. A variable 3462 gd->arch.secure_ram is used to track the location. In systems 3463 the RAM base is not zero, or RAM is divided into banks, 3464 this variable needs to be recalcuated to get the address. 3465 3466- CONFIG_SYS_MEM_TOP_HIDE: 3467 If CONFIG_SYS_MEM_TOP_HIDE is defined in the board config header, 3468 this specified memory area will get subtracted from the top 3469 (end) of RAM and won't get "touched" at all by U-Boot. By 3470 fixing up gd->ram_size the Linux kernel should gets passed 3471 the now "corrected" memory size and won't touch it either. 3472 This should work for arch/ppc and arch/powerpc. Only Linux 3473 board ports in arch/powerpc with bootwrapper support that 3474 recalculate the memory size from the SDRAM controller setup 3475 will have to get fixed in Linux additionally. 3476 3477 This option can be used as a workaround for the 440EPx/GRx 3478 CHIP 11 errata where the last 256 bytes in SDRAM shouldn't 3479 be touched. 3480 3481 WARNING: Please make sure that this value is a multiple of 3482 the Linux page size (normally 4k). If this is not the case, 3483 then the end address of the Linux memory will be located at a 3484 non page size aligned address and this could cause major 3485 problems. 3486 3487- CONFIG_SYS_LOADS_BAUD_CHANGE: 3488 Enable temporary baudrate change while serial download 3489 3490- CONFIG_SYS_SDRAM_BASE: 3491 Physical start address of SDRAM. _Must_ be 0 here. 3492 3493- CONFIG_SYS_FLASH_BASE: 3494 Physical start address of Flash memory. 3495 3496- CONFIG_SYS_MONITOR_BASE: 3497 Physical start address of boot monitor code (set by 3498 make config files to be same as the text base address 3499 (CONFIG_SYS_TEXT_BASE) used when linking) - same as 3500 CONFIG_SYS_FLASH_BASE when booting from flash. 3501 3502- CONFIG_SYS_MONITOR_LEN: 3503 Size of memory reserved for monitor code, used to 3504 determine _at_compile_time_ (!) if the environment is 3505 embedded within the U-Boot image, or in a separate 3506 flash sector. 3507 3508- CONFIG_SYS_MALLOC_LEN: 3509 Size of DRAM reserved for malloc() use. 3510 3511- CONFIG_SYS_MALLOC_F_LEN 3512 Size of the malloc() pool for use before relocation. If 3513 this is defined, then a very simple malloc() implementation 3514 will become available before relocation. The address is just 3515 below the global data, and the stack is moved down to make 3516 space. 3517 3518 This feature allocates regions with increasing addresses 3519 within the region. calloc() is supported, but realloc() 3520 is not available. free() is supported but does nothing. 3521 The memory will be freed (or in fact just forgotten) when 3522 U-Boot relocates itself. 3523 3524- CONFIG_SYS_MALLOC_SIMPLE 3525 Provides a simple and small malloc() and calloc() for those 3526 boards which do not use the full malloc in SPL (which is 3527 enabled with CONFIG_SYS_SPL_MALLOC_START). 3528 3529- CONFIG_SYS_NONCACHED_MEMORY: 3530 Size of non-cached memory area. This area of memory will be 3531 typically located right below the malloc() area and mapped 3532 uncached in the MMU. This is useful for drivers that would 3533 otherwise require a lot of explicit cache maintenance. For 3534 some drivers it's also impossible to properly maintain the 3535 cache. For example if the regions that need to be flushed 3536 are not a multiple of the cache-line size, *and* padding 3537 cannot be allocated between the regions to align them (i.e. 3538 if the HW requires a contiguous array of regions, and the 3539 size of each region is not cache-aligned), then a flush of 3540 one region may result in overwriting data that hardware has 3541 written to another region in the same cache-line. This can 3542 happen for example in network drivers where descriptors for 3543 buffers are typically smaller than the CPU cache-line (e.g. 3544 16 bytes vs. 32 or 64 bytes). 3545 3546 Non-cached memory is only supported on 32-bit ARM at present. 3547 3548- CONFIG_SYS_BOOTM_LEN: 3549 Normally compressed uImages are limited to an 3550 uncompressed size of 8 MBytes. If this is not enough, 3551 you can define CONFIG_SYS_BOOTM_LEN in your board config file 3552 to adjust this setting to your needs. 3553 3554- CONFIG_SYS_BOOTMAPSZ: 3555 Maximum size of memory mapped by the startup code of 3556 the Linux kernel; all data that must be processed by 3557 the Linux kernel (bd_info, boot arguments, FDT blob if 3558 used) must be put below this limit, unless "bootm_low" 3559 environment variable is defined and non-zero. In such case 3560 all data for the Linux kernel must be between "bootm_low" 3561 and "bootm_low" + CONFIG_SYS_BOOTMAPSZ. The environment 3562 variable "bootm_mapsize" will override the value of 3563 CONFIG_SYS_BOOTMAPSZ. If CONFIG_SYS_BOOTMAPSZ is undefined, 3564 then the value in "bootm_size" will be used instead. 3565 3566- CONFIG_SYS_BOOT_RAMDISK_HIGH: 3567 Enable initrd_high functionality. If defined then the 3568 initrd_high feature is enabled and the bootm ramdisk subcommand 3569 is enabled. 3570 3571- CONFIG_SYS_BOOT_GET_CMDLINE: 3572 Enables allocating and saving kernel cmdline in space between 3573 "bootm_low" and "bootm_low" + BOOTMAPSZ. 3574 3575- CONFIG_SYS_BOOT_GET_KBD: 3576 Enables allocating and saving a kernel copy of the bd_info in 3577 space between "bootm_low" and "bootm_low" + BOOTMAPSZ. 3578 3579- CONFIG_SYS_MAX_FLASH_BANKS: 3580 Max number of Flash memory banks 3581 3582- CONFIG_SYS_MAX_FLASH_SECT: 3583 Max number of sectors on a Flash chip 3584 3585- CONFIG_SYS_FLASH_ERASE_TOUT: 3586 Timeout for Flash erase operations (in ms) 3587 3588- CONFIG_SYS_FLASH_WRITE_TOUT: 3589 Timeout for Flash write operations (in ms) 3590 3591- CONFIG_SYS_FLASH_LOCK_TOUT 3592 Timeout for Flash set sector lock bit operation (in ms) 3593 3594- CONFIG_SYS_FLASH_UNLOCK_TOUT 3595 Timeout for Flash clear lock bits operation (in ms) 3596 3597- CONFIG_SYS_FLASH_PROTECTION 3598 If defined, hardware flash sectors protection is used 3599 instead of U-Boot software protection. 3600 3601- CONFIG_SYS_DIRECT_FLASH_TFTP: 3602 3603 Enable TFTP transfers directly to flash memory; 3604 without this option such a download has to be 3605 performed in two steps: (1) download to RAM, and (2) 3606 copy from RAM to flash. 3607 3608 The two-step approach is usually more reliable, since 3609 you can check if the download worked before you erase 3610 the flash, but in some situations (when system RAM is 3611 too limited to allow for a temporary copy of the 3612 downloaded image) this option may be very useful. 3613 3614- CONFIG_SYS_FLASH_CFI: 3615 Define if the flash driver uses extra elements in the 3616 common flash structure for storing flash geometry. 3617 3618- CONFIG_FLASH_CFI_DRIVER 3619 This option also enables the building of the cfi_flash driver 3620 in the drivers directory 3621 3622- CONFIG_FLASH_CFI_MTD 3623 This option enables the building of the cfi_mtd driver 3624 in the drivers directory. The driver exports CFI flash 3625 to the MTD layer. 3626 3627- CONFIG_SYS_FLASH_USE_BUFFER_WRITE 3628 Use buffered writes to flash. 3629 3630- CONFIG_FLASH_SPANSION_S29WS_N 3631 s29ws-n MirrorBit flash has non-standard addresses for buffered 3632 write commands. 3633 3634- CONFIG_SYS_FLASH_QUIET_TEST 3635 If this option is defined, the common CFI flash doesn't 3636 print it's warning upon not recognized FLASH banks. This 3637 is useful, if some of the configured banks are only 3638 optionally available. 3639 3640- CONFIG_FLASH_SHOW_PROGRESS 3641 If defined (must be an integer), print out countdown 3642 digits and dots. Recommended value: 45 (9..1) for 80 3643 column displays, 15 (3..1) for 40 column displays. 3644 3645- CONFIG_FLASH_VERIFY 3646 If defined, the content of the flash (destination) is compared 3647 against the source after the write operation. An error message 3648 will be printed when the contents are not identical. 3649 Please note that this option is useless in nearly all cases, 3650 since such flash programming errors usually are detected earlier 3651 while unprotecting/erasing/programming. Please only enable 3652 this option if you really know what you are doing. 3653 3654- CONFIG_SYS_RX_ETH_BUFFER: 3655 Defines the number of Ethernet receive buffers. On some 3656 Ethernet controllers it is recommended to set this value 3657 to 8 or even higher (EEPRO100 or 405 EMAC), since all 3658 buffers can be full shortly after enabling the interface 3659 on high Ethernet traffic. 3660 Defaults to 4 if not defined. 3661 3662- CONFIG_ENV_MAX_ENTRIES 3663 3664 Maximum number of entries in the hash table that is used 3665 internally to store the environment settings. The default 3666 setting is supposed to be generous and should work in most 3667 cases. This setting can be used to tune behaviour; see 3668 lib/hashtable.c for details. 3669 3670- CONFIG_ENV_FLAGS_LIST_DEFAULT 3671- CONFIG_ENV_FLAGS_LIST_STATIC 3672 Enable validation of the values given to environment variables when 3673 calling env set. Variables can be restricted to only decimal, 3674 hexadecimal, or boolean. If CONFIG_CMD_NET is also defined, 3675 the variables can also be restricted to IP address or MAC address. 3676 3677 The format of the list is: 3678 type_attribute = [s|d|x|b|i|m] 3679 access_attribute = [a|r|o|c] 3680 attributes = type_attribute[access_attribute] 3681 entry = variable_name[:attributes] 3682 list = entry[,list] 3683 3684 The type attributes are: 3685 s - String (default) 3686 d - Decimal 3687 x - Hexadecimal 3688 b - Boolean ([1yYtT|0nNfF]) 3689 i - IP address 3690 m - MAC address 3691 3692 The access attributes are: 3693 a - Any (default) 3694 r - Read-only 3695 o - Write-once 3696 c - Change-default 3697 3698 - CONFIG_ENV_FLAGS_LIST_DEFAULT 3699 Define this to a list (string) to define the ".flags" 3700 environment variable in the default or embedded environment. 3701 3702 - CONFIG_ENV_FLAGS_LIST_STATIC 3703 Define this to a list (string) to define validation that 3704 should be done if an entry is not found in the ".flags" 3705 environment variable. To override a setting in the static 3706 list, simply add an entry for the same variable name to the 3707 ".flags" variable. 3708 3709 If CONFIG_REGEX is defined, the variable_name above is evaluated as a 3710 regular expression. This allows multiple variables to define the same 3711 flags without explicitly listing them for each variable. 3712 3713- CONFIG_ENV_ACCESS_IGNORE_FORCE 3714 If defined, don't allow the -f switch to env set override variable 3715 access flags. 3716 3717- CONFIG_OMAP_PLATFORM_RESET_TIME_MAX_USEC (OMAP only) 3718 This is set by OMAP boards for the max time that reset should 3719 be asserted. See doc/README.omap-reset-time for details on how 3720 the value can be calculated on a given board. 3721 3722- CONFIG_USE_STDINT 3723 If stdint.h is available with your toolchain you can define this 3724 option to enable it. You can provide option 'USE_STDINT=1' when 3725 building U-Boot to enable this. 3726 3727The following definitions that deal with the placement and management 3728of environment data (variable area); in general, we support the 3729following configurations: 3730 3731- CONFIG_BUILD_ENVCRC: 3732 3733 Builds up envcrc with the target environment so that external utils 3734 may easily extract it and embed it in final U-Boot images. 3735 3736- CONFIG_ENV_IS_IN_FLASH: 3737 3738 Define this if the environment is in flash memory. 3739 3740 a) The environment occupies one whole flash sector, which is 3741 "embedded" in the text segment with the U-Boot code. This 3742 happens usually with "bottom boot sector" or "top boot 3743 sector" type flash chips, which have several smaller 3744 sectors at the start or the end. For instance, such a 3745 layout can have sector sizes of 8, 2x4, 16, Nx32 kB. In 3746 such a case you would place the environment in one of the 3747 4 kB sectors - with U-Boot code before and after it. With 3748 "top boot sector" type flash chips, you would put the 3749 environment in one of the last sectors, leaving a gap 3750 between U-Boot and the environment. 3751 3752 - CONFIG_ENV_OFFSET: 3753 3754 Offset of environment data (variable area) to the 3755 beginning of flash memory; for instance, with bottom boot 3756 type flash chips the second sector can be used: the offset 3757 for this sector is given here. 3758 3759 CONFIG_ENV_OFFSET is used relative to CONFIG_SYS_FLASH_BASE. 3760 3761 - CONFIG_ENV_ADDR: 3762 3763 This is just another way to specify the start address of 3764 the flash sector containing the environment (instead of 3765 CONFIG_ENV_OFFSET). 3766 3767 - CONFIG_ENV_SECT_SIZE: 3768 3769 Size of the sector containing the environment. 3770 3771 3772 b) Sometimes flash chips have few, equal sized, BIG sectors. 3773 In such a case you don't want to spend a whole sector for 3774 the environment. 3775 3776 - CONFIG_ENV_SIZE: 3777 3778 If you use this in combination with CONFIG_ENV_IS_IN_FLASH 3779 and CONFIG_ENV_SECT_SIZE, you can specify to use only a part 3780 of this flash sector for the environment. This saves 3781 memory for the RAM copy of the environment. 3782 3783 It may also save flash memory if you decide to use this 3784 when your environment is "embedded" within U-Boot code, 3785 since then the remainder of the flash sector could be used 3786 for U-Boot code. It should be pointed out that this is 3787 STRONGLY DISCOURAGED from a robustness point of view: 3788 updating the environment in flash makes it always 3789 necessary to erase the WHOLE sector. If something goes 3790 wrong before the contents has been restored from a copy in 3791 RAM, your target system will be dead. 3792 3793 - CONFIG_ENV_ADDR_REDUND 3794 CONFIG_ENV_SIZE_REDUND 3795 3796 These settings describe a second storage area used to hold 3797 a redundant copy of the environment data, so that there is 3798 a valid backup copy in case there is a power failure during 3799 a "saveenv" operation. 3800 3801BE CAREFUL! Any changes to the flash layout, and some changes to the 3802source code will make it necessary to adapt <board>/u-boot.lds* 3803accordingly! 3804 3805 3806- CONFIG_ENV_IS_IN_NVRAM: 3807 3808 Define this if you have some non-volatile memory device 3809 (NVRAM, battery buffered SRAM) which you want to use for the 3810 environment. 3811 3812 - CONFIG_ENV_ADDR: 3813 - CONFIG_ENV_SIZE: 3814 3815 These two #defines are used to determine the memory area you 3816 want to use for environment. It is assumed that this memory 3817 can just be read and written to, without any special 3818 provision. 3819 3820BE CAREFUL! The first access to the environment happens quite early 3821in U-Boot initialization (when we try to get the setting of for the 3822console baudrate). You *MUST* have mapped your NVRAM area then, or 3823U-Boot will hang. 3824 3825Please note that even with NVRAM we still use a copy of the 3826environment in RAM: we could work on NVRAM directly, but we want to 3827keep settings there always unmodified except somebody uses "saveenv" 3828to save the current settings. 3829 3830 3831- CONFIG_ENV_IS_IN_EEPROM: 3832 3833 Use this if you have an EEPROM or similar serial access 3834 device and a driver for it. 3835 3836 - CONFIG_ENV_OFFSET: 3837 - CONFIG_ENV_SIZE: 3838 3839 These two #defines specify the offset and size of the 3840 environment area within the total memory of your EEPROM. 3841 3842 - CONFIG_SYS_I2C_EEPROM_ADDR: 3843 If defined, specified the chip address of the EEPROM device. 3844 The default address is zero. 3845 3846 - CONFIG_SYS_I2C_EEPROM_BUS: 3847 If defined, specified the i2c bus of the EEPROM device. 3848 3849 - CONFIG_SYS_EEPROM_PAGE_WRITE_BITS: 3850 If defined, the number of bits used to address bytes in a 3851 single page in the EEPROM device. A 64 byte page, for example 3852 would require six bits. 3853 3854 - CONFIG_SYS_EEPROM_PAGE_WRITE_DELAY_MS: 3855 If defined, the number of milliseconds to delay between 3856 page writes. The default is zero milliseconds. 3857 3858 - CONFIG_SYS_I2C_EEPROM_ADDR_LEN: 3859 The length in bytes of the EEPROM memory array address. Note 3860 that this is NOT the chip address length! 3861 3862 - CONFIG_SYS_I2C_EEPROM_ADDR_OVERFLOW: 3863 EEPROM chips that implement "address overflow" are ones 3864 like Catalyst 24WC04/08/16 which has 9/10/11 bits of 3865 address and the extra bits end up in the "chip address" bit 3866 slots. This makes a 24WC08 (1Kbyte) chip look like four 256 3867 byte chips. 3868 3869 Note that we consider the length of the address field to 3870 still be one byte because the extra address bits are hidden 3871 in the chip address. 3872 3873 - CONFIG_SYS_EEPROM_SIZE: 3874 The size in bytes of the EEPROM device. 3875 3876 - CONFIG_ENV_EEPROM_IS_ON_I2C 3877 define this, if you have I2C and SPI activated, and your 3878 EEPROM, which holds the environment, is on the I2C bus. 3879 3880 - CONFIG_I2C_ENV_EEPROM_BUS 3881 if you have an Environment on an EEPROM reached over 3882 I2C muxes, you can define here, how to reach this 3883 EEPROM. For example: 3884 3885 #define CONFIG_I2C_ENV_EEPROM_BUS 1 3886 3887 EEPROM which holds the environment, is reached over 3888 a pca9547 i2c mux with address 0x70, channel 3. 3889 3890- CONFIG_ENV_IS_IN_DATAFLASH: 3891 3892 Define this if you have a DataFlash memory device which you 3893 want to use for the environment. 3894 3895 - CONFIG_ENV_OFFSET: 3896 - CONFIG_ENV_ADDR: 3897 - CONFIG_ENV_SIZE: 3898 3899 These three #defines specify the offset and size of the 3900 environment area within the total memory of your DataFlash placed 3901 at the specified address. 3902 3903- CONFIG_ENV_IS_IN_SPI_FLASH: 3904 3905 Define this if you have a SPI Flash memory device which you 3906 want to use for the environment. 3907 3908 - CONFIG_ENV_OFFSET: 3909 - CONFIG_ENV_SIZE: 3910 3911 These two #defines specify the offset and size of the 3912 environment area within the SPI Flash. CONFIG_ENV_OFFSET must be 3913 aligned to an erase sector boundary. 3914 3915 - CONFIG_ENV_SECT_SIZE: 3916 3917 Define the SPI flash's sector size. 3918 3919 - CONFIG_ENV_OFFSET_REDUND (optional): 3920 3921 This setting describes a second storage area of CONFIG_ENV_SIZE 3922 size used to hold a redundant copy of the environment data, so 3923 that there is a valid backup copy in case there is a power failure 3924 during a "saveenv" operation. CONFIG_ENV_OFFSET_REDUND must be 3925 aligned to an erase sector boundary. 3926 3927 - CONFIG_ENV_SPI_BUS (optional): 3928 - CONFIG_ENV_SPI_CS (optional): 3929 3930 Define the SPI bus and chip select. If not defined they will be 0. 3931 3932 - CONFIG_ENV_SPI_MAX_HZ (optional): 3933 3934 Define the SPI max work clock. If not defined then use 1MHz. 3935 3936 - CONFIG_ENV_SPI_MODE (optional): 3937 3938 Define the SPI work mode. If not defined then use SPI_MODE_3. 3939 3940- CONFIG_ENV_IS_IN_REMOTE: 3941 3942 Define this if you have a remote memory space which you 3943 want to use for the local device's environment. 3944 3945 - CONFIG_ENV_ADDR: 3946 - CONFIG_ENV_SIZE: 3947 3948 These two #defines specify the address and size of the 3949 environment area within the remote memory space. The 3950 local device can get the environment from remote memory 3951 space by SRIO or PCIE links. 3952 3953BE CAREFUL! For some special cases, the local device can not use 3954"saveenv" command. For example, the local device will get the 3955environment stored in a remote NOR flash by SRIO or PCIE link, 3956but it can not erase, write this NOR flash by SRIO or PCIE interface. 3957 3958- CONFIG_ENV_IS_IN_NAND: 3959 3960 Define this if you have a NAND device which you want to use 3961 for the environment. 3962 3963 - CONFIG_ENV_OFFSET: 3964 - CONFIG_ENV_SIZE: 3965 3966 These two #defines specify the offset and size of the environment 3967 area within the first NAND device. CONFIG_ENV_OFFSET must be 3968 aligned to an erase block boundary. 3969 3970 - CONFIG_ENV_OFFSET_REDUND (optional): 3971 3972 This setting describes a second storage area of CONFIG_ENV_SIZE 3973 size used to hold a redundant copy of the environment data, so 3974 that there is a valid backup copy in case there is a power failure 3975 during a "saveenv" operation. CONFIG_ENV_OFFSET_REDUND must be 3976 aligned to an erase block boundary. 3977 3978 - CONFIG_ENV_RANGE (optional): 3979 3980 Specifies the length of the region in which the environment 3981 can be written. This should be a multiple of the NAND device's 3982 block size. Specifying a range with more erase blocks than 3983 are needed to hold CONFIG_ENV_SIZE allows bad blocks within 3984 the range to be avoided. 3985 3986 - CONFIG_ENV_OFFSET_OOB (optional): 3987 3988 Enables support for dynamically retrieving the offset of the 3989 environment from block zero's out-of-band data. The 3990 "nand env.oob" command can be used to record this offset. 3991 Currently, CONFIG_ENV_OFFSET_REDUND is not supported when 3992 using CONFIG_ENV_OFFSET_OOB. 3993 3994- CONFIG_NAND_ENV_DST 3995 3996 Defines address in RAM to which the nand_spl code should copy the 3997 environment. If redundant environment is used, it will be copied to 3998 CONFIG_NAND_ENV_DST + CONFIG_ENV_SIZE. 3999 4000- CONFIG_ENV_IS_IN_UBI: 4001 4002 Define this if you have an UBI volume that you want to use for the 4003 environment. This has the benefit of wear-leveling the environment 4004 accesses, which is important on NAND. 4005 4006 - CONFIG_ENV_UBI_PART: 4007 4008 Define this to a string that is the mtd partition containing the UBI. 4009 4010 - CONFIG_ENV_UBI_VOLUME: 4011 4012 Define this to the name of the volume that you want to store the 4013 environment in. 4014 4015 - CONFIG_ENV_UBI_VOLUME_REDUND: 4016 4017 Define this to the name of another volume to store a second copy of 4018 the environment in. This will enable redundant environments in UBI. 4019 It is assumed that both volumes are in the same MTD partition. 4020 4021 - CONFIG_UBI_SILENCE_MSG 4022 - CONFIG_UBIFS_SILENCE_MSG 4023 4024 You will probably want to define these to avoid a really noisy system 4025 when storing the env in UBI. 4026 4027- CONFIG_ENV_IS_IN_FAT: 4028 Define this if you want to use the FAT file system for the environment. 4029 4030 - FAT_ENV_INTERFACE: 4031 4032 Define this to a string that is the name of the block device. 4033 4034 - FAT_ENV_DEVICE_AND_PART: 4035 4036 Define this to a string to specify the partition of the device. It can 4037 be as following: 4038 4039 "D:P", "D:0", "D", "D:" or "D:auto" (D, P are integers. And P >= 1) 4040 - "D:P": device D partition P. Error occurs if device D has no 4041 partition table. 4042 - "D:0": device D. 4043 - "D" or "D:": device D partition 1 if device D has partition 4044 table, or the whole device D if has no partition 4045 table. 4046 - "D:auto": first partition in device D with bootable flag set. 4047 If none, first valid partition in device D. If no 4048 partition table then means device D. 4049 4050 - FAT_ENV_FILE: 4051 4052 It's a string of the FAT file name. This file use to store the 4053 environment. 4054 4055 - CONFIG_FAT_WRITE: 4056 This should be defined. Otherwise it cannot save the environment file. 4057 4058- CONFIG_ENV_IS_IN_MMC: 4059 4060 Define this if you have an MMC device which you want to use for the 4061 environment. 4062 4063 - CONFIG_SYS_MMC_ENV_DEV: 4064 4065 Specifies which MMC device the environment is stored in. 4066 4067 - CONFIG_SYS_MMC_ENV_PART (optional): 4068 4069 Specifies which MMC partition the environment is stored in. If not 4070 set, defaults to partition 0, the user area. Common values might be 4071 1 (first MMC boot partition), 2 (second MMC boot partition). 4072 4073 - CONFIG_ENV_OFFSET: 4074 - CONFIG_ENV_SIZE: 4075 4076 These two #defines specify the offset and size of the environment 4077 area within the specified MMC device. 4078 4079 If offset is positive (the usual case), it is treated as relative to 4080 the start of the MMC partition. If offset is negative, it is treated 4081 as relative to the end of the MMC partition. This can be useful if 4082 your board may be fitted with different MMC devices, which have 4083 different sizes for the MMC partitions, and you always want the 4084 environment placed at the very end of the partition, to leave the 4085 maximum possible space before it, to store other data. 4086 4087 These two values are in units of bytes, but must be aligned to an 4088 MMC sector boundary. 4089 4090 - CONFIG_ENV_OFFSET_REDUND (optional): 4091 4092 Specifies a second storage area, of CONFIG_ENV_SIZE size, used to 4093 hold a redundant copy of the environment data. This provides a 4094 valid backup copy in case the other copy is corrupted, e.g. due 4095 to a power failure during a "saveenv" operation. 4096 4097 This value may also be positive or negative; this is handled in the 4098 same way as CONFIG_ENV_OFFSET. 4099 4100 This value is also in units of bytes, but must also be aligned to 4101 an MMC sector boundary. 4102 4103 - CONFIG_ENV_SIZE_REDUND (optional): 4104 4105 This value need not be set, even when CONFIG_ENV_OFFSET_REDUND is 4106 set. If this value is set, it must be set to the same value as 4107 CONFIG_ENV_SIZE. 4108 4109- CONFIG_SYS_SPI_INIT_OFFSET 4110 4111 Defines offset to the initial SPI buffer area in DPRAM. The 4112 area is used at an early stage (ROM part) if the environment 4113 is configured to reside in the SPI EEPROM: We need a 520 byte 4114 scratch DPRAM area. It is used between the two initialization 4115 calls (spi_init_f() and spi_init_r()). A value of 0xB00 seems 4116 to be a good choice since it makes it far enough from the 4117 start of the data area as well as from the stack pointer. 4118 4119Please note that the environment is read-only until the monitor 4120has been relocated to RAM and a RAM copy of the environment has been 4121created; also, when using EEPROM you will have to use getenv_f() 4122until then to read environment variables. 4123 4124The environment is protected by a CRC32 checksum. Before the monitor 4125is relocated into RAM, as a result of a bad CRC you will be working 4126with the compiled-in default environment - *silently*!!! [This is 4127necessary, because the first environment variable we need is the 4128"baudrate" setting for the console - if we have a bad CRC, we don't 4129have any device yet where we could complain.] 4130 4131Note: once the monitor has been relocated, then it will complain if 4132the default environment is used; a new CRC is computed as soon as you 4133use the "saveenv" command to store a valid environment. 4134 4135- CONFIG_SYS_FAULT_ECHO_LINK_DOWN: 4136 Echo the inverted Ethernet link state to the fault LED. 4137 4138 Note: If this option is active, then CONFIG_SYS_FAULT_MII_ADDR 4139 also needs to be defined. 4140 4141- CONFIG_SYS_FAULT_MII_ADDR: 4142 MII address of the PHY to check for the Ethernet link state. 4143 4144- CONFIG_NS16550_MIN_FUNCTIONS: 4145 Define this if you desire to only have use of the NS16550_init 4146 and NS16550_putc functions for the serial driver located at 4147 drivers/serial/ns16550.c. This option is useful for saving 4148 space for already greatly restricted images, including but not 4149 limited to NAND_SPL configurations. 4150 4151- CONFIG_DISPLAY_BOARDINFO 4152 Display information about the board that U-Boot is running on 4153 when U-Boot starts up. The board function checkboard() is called 4154 to do this. 4155 4156- CONFIG_DISPLAY_BOARDINFO_LATE 4157 Similar to the previous option, but display this information 4158 later, once stdio is running and output goes to the LCD, if 4159 present. 4160 4161- CONFIG_BOARD_SIZE_LIMIT: 4162 Maximum size of the U-Boot image. When defined, the 4163 build system checks that the actual size does not 4164 exceed it. 4165 4166Low Level (hardware related) configuration options: 4167--------------------------------------------------- 4168 4169- CONFIG_SYS_CACHELINE_SIZE: 4170 Cache Line Size of the CPU. 4171 4172- CONFIG_SYS_DEFAULT_IMMR: 4173 Default address of the IMMR after system reset. 4174 4175 Needed on some 8260 systems (MPC8260ADS, PQ2FADS-ZU, 4176 and RPXsuper) to be able to adjust the position of 4177 the IMMR register after a reset. 4178 4179- CONFIG_SYS_CCSRBAR_DEFAULT: 4180 Default (power-on reset) physical address of CCSR on Freescale 4181 PowerPC SOCs. 4182 4183- CONFIG_SYS_CCSRBAR: 4184 Virtual address of CCSR. On a 32-bit build, this is typically 4185 the same value as CONFIG_SYS_CCSRBAR_DEFAULT. 4186 4187 CONFIG_SYS_DEFAULT_IMMR must also be set to this value, 4188 for cross-platform code that uses that macro instead. 4189 4190- CONFIG_SYS_CCSRBAR_PHYS: 4191 Physical address of CCSR. CCSR can be relocated to a new 4192 physical address, if desired. In this case, this macro should 4193 be set to that address. Otherwise, it should be set to the 4194 same value as CONFIG_SYS_CCSRBAR_DEFAULT. For example, CCSR 4195 is typically relocated on 36-bit builds. It is recommended 4196 that this macro be defined via the _HIGH and _LOW macros: 4197 4198 #define CONFIG_SYS_CCSRBAR_PHYS ((CONFIG_SYS_CCSRBAR_PHYS_HIGH 4199 * 1ull) << 32 | CONFIG_SYS_CCSRBAR_PHYS_LOW) 4200 4201- CONFIG_SYS_CCSRBAR_PHYS_HIGH: 4202 Bits 33-36 of CONFIG_SYS_CCSRBAR_PHYS. This value is typically 4203 either 0 (32-bit build) or 0xF (36-bit build). This macro is 4204 used in assembly code, so it must not contain typecasts or 4205 integer size suffixes (e.g. "ULL"). 4206 4207- CONFIG_SYS_CCSRBAR_PHYS_LOW: 4208 Lower 32-bits of CONFIG_SYS_CCSRBAR_PHYS. This macro is 4209 used in assembly code, so it must not contain typecasts or 4210 integer size suffixes (e.g. "ULL"). 4211 4212- CONFIG_SYS_CCSR_DO_NOT_RELOCATE: 4213 If this macro is defined, then CONFIG_SYS_CCSRBAR_PHYS will be 4214 forced to a value that ensures that CCSR is not relocated. 4215 4216- Floppy Disk Support: 4217 CONFIG_SYS_FDC_DRIVE_NUMBER 4218 4219 the default drive number (default value 0) 4220 4221 CONFIG_SYS_ISA_IO_STRIDE 4222 4223 defines the spacing between FDC chipset registers 4224 (default value 1) 4225 4226 CONFIG_SYS_ISA_IO_OFFSET 4227 4228 defines the offset of register from address. It 4229 depends on which part of the data bus is connected to 4230 the FDC chipset. (default value 0) 4231 4232 If CONFIG_SYS_ISA_IO_STRIDE CONFIG_SYS_ISA_IO_OFFSET and 4233 CONFIG_SYS_FDC_DRIVE_NUMBER are undefined, they take their 4234 default value. 4235 4236 if CONFIG_SYS_FDC_HW_INIT is defined, then the function 4237 fdc_hw_init() is called at the beginning of the FDC 4238 setup. fdc_hw_init() must be provided by the board 4239 source code. It is used to make hardware-dependent 4240 initializations. 4241 4242- CONFIG_IDE_AHB: 4243 Most IDE controllers were designed to be connected with PCI 4244 interface. Only few of them were designed for AHB interface. 4245 When software is doing ATA command and data transfer to 4246 IDE devices through IDE-AHB controller, some additional 4247 registers accessing to these kind of IDE-AHB controller 4248 is required. 4249 4250- CONFIG_SYS_IMMR: Physical address of the Internal Memory. 4251 DO NOT CHANGE unless you know exactly what you're 4252 doing! (11-4) [MPC8xx/82xx systems only] 4253 4254- CONFIG_SYS_INIT_RAM_ADDR: 4255 4256 Start address of memory area that can be used for 4257 initial data and stack; please note that this must be 4258 writable memory that is working WITHOUT special 4259 initialization, i. e. you CANNOT use normal RAM which 4260 will become available only after programming the 4261 memory controller and running certain initialization 4262 sequences. 4263 4264 U-Boot uses the following memory types: 4265 - MPC8xx and MPC8260: IMMR (internal memory of the CPU) 4266 - MPC824X: data cache 4267 - PPC4xx: data cache 4268 4269- CONFIG_SYS_GBL_DATA_OFFSET: 4270 4271 Offset of the initial data structure in the memory 4272 area defined by CONFIG_SYS_INIT_RAM_ADDR. Usually 4273 CONFIG_SYS_GBL_DATA_OFFSET is chosen such that the initial 4274 data is located at the end of the available space 4275 (sometimes written as (CONFIG_SYS_INIT_RAM_SIZE - 4276 GENERATED_GBL_DATA_SIZE), and the initial stack is just 4277 below that area (growing from (CONFIG_SYS_INIT_RAM_ADDR + 4278 CONFIG_SYS_GBL_DATA_OFFSET) downward. 4279 4280 Note: 4281 On the MPC824X (or other systems that use the data 4282 cache for initial memory) the address chosen for 4283 CONFIG_SYS_INIT_RAM_ADDR is basically arbitrary - it must 4284 point to an otherwise UNUSED address space between 4285 the top of RAM and the start of the PCI space. 4286 4287- CONFIG_SYS_SIUMCR: SIU Module Configuration (11-6) 4288 4289- CONFIG_SYS_SYPCR: System Protection Control (11-9) 4290 4291- CONFIG_SYS_TBSCR: Time Base Status and Control (11-26) 4292 4293- CONFIG_SYS_PISCR: Periodic Interrupt Status and Control (11-31) 4294 4295- CONFIG_SYS_PLPRCR: PLL, Low-Power, and Reset Control Register (15-30) 4296 4297- CONFIG_SYS_SCCR: System Clock and reset Control Register (15-27) 4298 4299- CONFIG_SYS_OR_TIMING_SDRAM: 4300 SDRAM timing 4301 4302- CONFIG_SYS_MAMR_PTA: 4303 periodic timer for refresh 4304 4305- CONFIG_SYS_DER: Debug Event Register (37-47) 4306 4307- FLASH_BASE0_PRELIM, FLASH_BASE1_PRELIM, CONFIG_SYS_REMAP_OR_AM, 4308 CONFIG_SYS_PRELIM_OR_AM, CONFIG_SYS_OR_TIMING_FLASH, CONFIG_SYS_OR0_REMAP, 4309 CONFIG_SYS_OR0_PRELIM, CONFIG_SYS_BR0_PRELIM, CONFIG_SYS_OR1_REMAP, CONFIG_SYS_OR1_PRELIM, 4310 CONFIG_SYS_BR1_PRELIM: 4311 Memory Controller Definitions: BR0/1 and OR0/1 (FLASH) 4312 4313- SDRAM_BASE2_PRELIM, SDRAM_BASE3_PRELIM, SDRAM_MAX_SIZE, 4314 CONFIG_SYS_OR_TIMING_SDRAM, CONFIG_SYS_OR2_PRELIM, CONFIG_SYS_BR2_PRELIM, 4315 CONFIG_SYS_OR3_PRELIM, CONFIG_SYS_BR3_PRELIM: 4316 Memory Controller Definitions: BR2/3 and OR2/3 (SDRAM) 4317 4318- CONFIG_SYS_MAMR_PTA, CONFIG_SYS_MPTPR_2BK_4K, CONFIG_SYS_MPTPR_1BK_4K, CONFIG_SYS_MPTPR_2BK_8K, 4319 CONFIG_SYS_MPTPR_1BK_8K, CONFIG_SYS_MAMR_8COL, CONFIG_SYS_MAMR_9COL: 4320 Machine Mode Register and Memory Periodic Timer 4321 Prescaler definitions (SDRAM timing) 4322 4323- CONFIG_SYS_I2C_UCODE_PATCH, CONFIG_SYS_I2C_DPMEM_OFFSET [0x1FC0]: 4324 enable I2C microcode relocation patch (MPC8xx); 4325 define relocation offset in DPRAM [DSP2] 4326 4327- CONFIG_SYS_SMC_UCODE_PATCH, CONFIG_SYS_SMC_DPMEM_OFFSET [0x1FC0]: 4328 enable SMC microcode relocation patch (MPC8xx); 4329 define relocation offset in DPRAM [SMC1] 4330 4331- CONFIG_SYS_SPI_UCODE_PATCH, CONFIG_SYS_SPI_DPMEM_OFFSET [0x1FC0]: 4332 enable SPI microcode relocation patch (MPC8xx); 4333 define relocation offset in DPRAM [SCC4] 4334 4335- CONFIG_SYS_CPM_POST_WORD_ADDR: (MPC8xx, MPC8260 only) 4336 Offset of the bootmode word in DPRAM used by post 4337 (Power On Self Tests). This definition overrides 4338 #define'd default value in commproc.h resp. 4339 cpm_8260.h. 4340 4341- CONFIG_SYS_PCI_SLV_MEM_LOCAL, CONFIG_SYS_PCI_SLV_MEM_BUS, CONFIG_SYS_PICMR0_MASK_ATTRIB, 4342 CONFIG_SYS_PCI_MSTR0_LOCAL, CONFIG_SYS_PCIMSK0_MASK, CONFIG_SYS_PCI_MSTR1_LOCAL, 4343 CONFIG_SYS_PCIMSK1_MASK, CONFIG_SYS_PCI_MSTR_MEM_LOCAL, CONFIG_SYS_PCI_MSTR_MEM_BUS, 4344 CONFIG_SYS_CPU_PCI_MEM_START, CONFIG_SYS_PCI_MSTR_MEM_SIZE, CONFIG_SYS_POCMR0_MASK_ATTRIB, 4345 CONFIG_SYS_PCI_MSTR_MEMIO_LOCAL, CONFIG_SYS_PCI_MSTR_MEMIO_BUS, CPU_PCI_MEMIO_START, 4346 CONFIG_SYS_PCI_MSTR_MEMIO_SIZE, CONFIG_SYS_POCMR1_MASK_ATTRIB, CONFIG_SYS_PCI_MSTR_IO_LOCAL, 4347 CONFIG_SYS_PCI_MSTR_IO_BUS, CONFIG_SYS_CPU_PCI_IO_START, CONFIG_SYS_PCI_MSTR_IO_SIZE, 4348 CONFIG_SYS_POCMR2_MASK_ATTRIB: (MPC826x only) 4349 Overrides the default PCI memory map in arch/powerpc/cpu/mpc8260/pci.c if set. 4350 4351- CONFIG_PCI_DISABLE_PCIE: 4352 Disable PCI-Express on systems where it is supported but not 4353 required. 4354 4355- CONFIG_PCI_ENUM_ONLY 4356 Only scan through and get the devices on the buses. 4357 Don't do any setup work, presumably because someone or 4358 something has already done it, and we don't need to do it 4359 a second time. Useful for platforms that are pre-booted 4360 by coreboot or similar. 4361 4362- CONFIG_PCI_INDIRECT_BRIDGE: 4363 Enable support for indirect PCI bridges. 4364 4365- CONFIG_SYS_SRIO: 4366 Chip has SRIO or not 4367 4368- CONFIG_SRIO1: 4369 Board has SRIO 1 port available 4370 4371- CONFIG_SRIO2: 4372 Board has SRIO 2 port available 4373 4374- CONFIG_SRIO_PCIE_BOOT_MASTER 4375 Board can support master function for Boot from SRIO and PCIE 4376 4377- CONFIG_SYS_SRIOn_MEM_VIRT: 4378 Virtual Address of SRIO port 'n' memory region 4379 4380- CONFIG_SYS_SRIOn_MEM_PHYS: 4381 Physical Address of SRIO port 'n' memory region 4382 4383- CONFIG_SYS_SRIOn_MEM_SIZE: 4384 Size of SRIO port 'n' memory region 4385 4386- CONFIG_SYS_NAND_BUSWIDTH_16BIT 4387 Defined to tell the NAND controller that the NAND chip is using 4388 a 16 bit bus. 4389 Not all NAND drivers use this symbol. 4390 Example of drivers that use it: 4391 - drivers/mtd/nand/ndfc.c 4392 - drivers/mtd/nand/mxc_nand.c 4393 4394- CONFIG_SYS_NDFC_EBC0_CFG 4395 Sets the EBC0_CFG register for the NDFC. If not defined 4396 a default value will be used. 4397 4398- CONFIG_SPD_EEPROM 4399 Get DDR timing information from an I2C EEPROM. Common 4400 with pluggable memory modules such as SODIMMs 4401 4402 SPD_EEPROM_ADDRESS 4403 I2C address of the SPD EEPROM 4404 4405- CONFIG_SYS_SPD_BUS_NUM 4406 If SPD EEPROM is on an I2C bus other than the first 4407 one, specify here. Note that the value must resolve 4408 to something your driver can deal with. 4409 4410- CONFIG_SYS_DDR_RAW_TIMING 4411 Get DDR timing information from other than SPD. Common with 4412 soldered DDR chips onboard without SPD. DDR raw timing 4413 parameters are extracted from datasheet and hard-coded into 4414 header files or board specific files. 4415 4416- CONFIG_FSL_DDR_INTERACTIVE 4417 Enable interactive DDR debugging. See doc/README.fsl-ddr. 4418 4419- CONFIG_FSL_DDR_SYNC_REFRESH 4420 Enable sync of refresh for multiple controllers. 4421 4422- CONFIG_FSL_DDR_BIST 4423 Enable built-in memory test for Freescale DDR controllers. 4424 4425- CONFIG_SYS_83XX_DDR_USES_CS0 4426 Only for 83xx systems. If specified, then DDR should 4427 be configured using CS0 and CS1 instead of CS2 and CS3. 4428 4429- CONFIG_ETHER_ON_FEC[12] 4430 Define to enable FEC[12] on a 8xx series processor. 4431 4432- CONFIG_FEC[12]_PHY 4433 Define to the hardcoded PHY address which corresponds 4434 to the given FEC; i. e. 4435 #define CONFIG_FEC1_PHY 4 4436 means that the PHY with address 4 is connected to FEC1 4437 4438 When set to -1, means to probe for first available. 4439 4440- CONFIG_FEC[12]_PHY_NORXERR 4441 The PHY does not have a RXERR line (RMII only). 4442 (so program the FEC to ignore it). 4443 4444- CONFIG_RMII 4445 Enable RMII mode for all FECs. 4446 Note that this is a global option, we can't 4447 have one FEC in standard MII mode and another in RMII mode. 4448 4449- CONFIG_CRC32_VERIFY 4450 Add a verify option to the crc32 command. 4451 The syntax is: 4452 4453 => crc32 -v <address> <count> <crc32> 4454 4455 Where address/count indicate a memory area 4456 and crc32 is the correct crc32 which the 4457 area should have. 4458 4459- CONFIG_LOOPW 4460 Add the "loopw" memory command. This only takes effect if 4461 the memory commands are activated globally (CONFIG_CMD_MEM). 4462 4463- CONFIG_MX_CYCLIC 4464 Add the "mdc" and "mwc" memory commands. These are cyclic 4465 "md/mw" commands. 4466 Examples: 4467 4468 => mdc.b 10 4 500 4469 This command will print 4 bytes (10,11,12,13) each 500 ms. 4470 4471 => mwc.l 100 12345678 10 4472 This command will write 12345678 to address 100 all 10 ms. 4473 4474 This only takes effect if the memory commands are activated 4475 globally (CONFIG_CMD_MEM). 4476 4477- CONFIG_SKIP_LOWLEVEL_INIT 4478 [ARM, NDS32, MIPS only] If this variable is defined, then certain 4479 low level initializations (like setting up the memory 4480 controller) are omitted and/or U-Boot does not 4481 relocate itself into RAM. 4482 4483 Normally this variable MUST NOT be defined. The only 4484 exception is when U-Boot is loaded (to RAM) by some 4485 other boot loader or by a debugger which performs 4486 these initializations itself. 4487 4488- CONFIG_SKIP_LOWLEVEL_INIT_ONLY 4489 [ARM926EJ-S only] This allows just the call to lowlevel_init() 4490 to be skipped. The normal CP15 init (such as enabling the 4491 instruction cache) is still performed. 4492 4493- CONFIG_SPL_BUILD 4494 Modifies the behaviour of start.S when compiling a loader 4495 that is executed before the actual U-Boot. E.g. when 4496 compiling a NAND SPL. 4497 4498- CONFIG_TPL_BUILD 4499 Modifies the behaviour of start.S when compiling a loader 4500 that is executed after the SPL and before the actual U-Boot. 4501 It is loaded by the SPL. 4502 4503- CONFIG_SYS_MPC85XX_NO_RESETVEC 4504 Only for 85xx systems. If this variable is specified, the section 4505 .resetvec is not kept and the section .bootpg is placed in the 4506 previous 4k of the .text section. 4507 4508- CONFIG_ARCH_MAP_SYSMEM 4509 Generally U-Boot (and in particular the md command) uses 4510 effective address. It is therefore not necessary to regard 4511 U-Boot address as virtual addresses that need to be translated 4512 to physical addresses. However, sandbox requires this, since 4513 it maintains its own little RAM buffer which contains all 4514 addressable memory. This option causes some memory accesses 4515 to be mapped through map_sysmem() / unmap_sysmem(). 4516 4517- CONFIG_X86_RESET_VECTOR 4518 If defined, the x86 reset vector code is included. This is not 4519 needed when U-Boot is running from Coreboot. 4520 4521- CONFIG_SYS_MPUCLK 4522 Defines the MPU clock speed (in MHz). 4523 4524 NOTE : currently only supported on AM335x platforms. 4525 4526- CONFIG_SPL_AM33XX_ENABLE_RTC32K_OSC: 4527 Enables the RTC32K OSC on AM33xx based plattforms 4528 4529- CONFIG_SYS_NAND_NO_SUBPAGE_WRITE 4530 Option to disable subpage write in NAND driver 4531 driver that uses this: 4532 drivers/mtd/nand/davinci_nand.c 4533 4534Freescale QE/FMAN Firmware Support: 4535----------------------------------- 4536 4537The Freescale QUICCEngine (QE) and Frame Manager (FMAN) both support the 4538loading of "firmware", which is encoded in the QE firmware binary format. 4539This firmware often needs to be loaded during U-Boot booting, so macros 4540are used to identify the storage device (NOR flash, SPI, etc) and the address 4541within that device. 4542 4543- CONFIG_SYS_FMAN_FW_ADDR 4544 The address in the storage device where the FMAN microcode is located. The 4545 meaning of this address depends on which CONFIG_SYS_QE_FW_IN_xxx macro 4546 is also specified. 4547 4548- CONFIG_SYS_QE_FW_ADDR 4549 The address in the storage device where the QE microcode is located. The 4550 meaning of this address depends on which CONFIG_SYS_QE_FW_IN_xxx macro 4551 is also specified. 4552 4553- CONFIG_SYS_QE_FMAN_FW_LENGTH 4554 The maximum possible size of the firmware. The firmware binary format 4555 has a field that specifies the actual size of the firmware, but it 4556 might not be possible to read any part of the firmware unless some 4557 local storage is allocated to hold the entire firmware first. 4558 4559- CONFIG_SYS_QE_FMAN_FW_IN_NOR 4560 Specifies that QE/FMAN firmware is located in NOR flash, mapped as 4561 normal addressable memory via the LBC. CONFIG_SYS_FMAN_FW_ADDR is the 4562 virtual address in NOR flash. 4563 4564- CONFIG_SYS_QE_FMAN_FW_IN_NAND 4565 Specifies that QE/FMAN firmware is located in NAND flash. 4566 CONFIG_SYS_FMAN_FW_ADDR is the offset within NAND flash. 4567 4568- CONFIG_SYS_QE_FMAN_FW_IN_MMC 4569 Specifies that QE/FMAN firmware is located on the primary SD/MMC 4570 device. CONFIG_SYS_FMAN_FW_ADDR is the byte offset on that device. 4571 4572- CONFIG_SYS_QE_FMAN_FW_IN_REMOTE 4573 Specifies that QE/FMAN firmware is located in the remote (master) 4574 memory space. CONFIG_SYS_FMAN_FW_ADDR is a virtual address which 4575 can be mapped from slave TLB->slave LAW->slave SRIO or PCIE outbound 4576 window->master inbound window->master LAW->the ucode address in 4577 master's memory space. 4578 4579Freescale Layerscape Management Complex Firmware Support: 4580--------------------------------------------------------- 4581The Freescale Layerscape Management Complex (MC) supports the loading of 4582"firmware". 4583This firmware often needs to be loaded during U-Boot booting, so macros 4584are used to identify the storage device (NOR flash, SPI, etc) and the address 4585within that device. 4586 4587- CONFIG_FSL_MC_ENET 4588 Enable the MC driver for Layerscape SoCs. 4589 4590Freescale Layerscape Debug Server Support: 4591------------------------------------------- 4592The Freescale Layerscape Debug Server Support supports the loading of 4593"Debug Server firmware" and triggering SP boot-rom. 4594This firmware often needs to be loaded during U-Boot booting. 4595 4596- CONFIG_SYS_MC_RSV_MEM_ALIGN 4597 Define alignment of reserved memory MC requires 4598 4599Reproducible builds 4600------------------- 4601 4602In order to achieve reproducible builds, timestamps used in the U-Boot build 4603process have to be set to a fixed value. 4604 4605This is done using the SOURCE_DATE_EPOCH environment variable. 4606SOURCE_DATE_EPOCH is to be set on the build host's shell, not as a configuration 4607option for U-Boot or an environment variable in U-Boot. 4608 4609SOURCE_DATE_EPOCH should be set to a number of seconds since the epoch, in UTC. 4610 4611Building the Software: 4612====================== 4613 4614Building U-Boot has been tested in several native build environments 4615and in many different cross environments. Of course we cannot support 4616all possibly existing versions of cross development tools in all 4617(potentially obsolete) versions. In case of tool chain problems we 4618recommend to use the ELDK (see http://www.denx.de/wiki/DULG/ELDK) 4619which is extensively used to build and test U-Boot. 4620 4621If you are not using a native environment, it is assumed that you 4622have GNU cross compiling tools available in your path. In this case, 4623you must set the environment variable CROSS_COMPILE in your shell. 4624Note that no changes to the Makefile or any other source files are 4625necessary. For example using the ELDK on a 4xx CPU, please enter: 4626 4627 $ CROSS_COMPILE=ppc_4xx- 4628 $ export CROSS_COMPILE 4629 4630Note: If you wish to generate Windows versions of the utilities in 4631 the tools directory you can use the MinGW toolchain 4632 (http://www.mingw.org). Set your HOST tools to the MinGW 4633 toolchain and execute 'make tools'. For example: 4634 4635 $ make HOSTCC=i586-mingw32msvc-gcc HOSTSTRIP=i586-mingw32msvc-strip tools 4636 4637 Binaries such as tools/mkimage.exe will be created which can 4638 be executed on computers running Windows. 4639 4640U-Boot is intended to be simple to build. After installing the 4641sources you must configure U-Boot for one specific board type. This 4642is done by typing: 4643 4644 make NAME_defconfig 4645 4646where "NAME_defconfig" is the name of one of the existing configu- 4647rations; see boards.cfg for supported names. 4648 4649Note: for some board special configuration names may exist; check if 4650 additional information is available from the board vendor; for 4651 instance, the TQM823L systems are available without (standard) 4652 or with LCD support. You can select such additional "features" 4653 when choosing the configuration, i. e. 4654 4655 make TQM823L_defconfig 4656 - will configure for a plain TQM823L, i. e. no LCD support 4657 4658 make TQM823L_LCD_defconfig 4659 - will configure for a TQM823L with U-Boot console on LCD 4660 4661 etc. 4662 4663 4664Finally, type "make all", and you should get some working U-Boot 4665images ready for download to / installation on your system: 4666 4667- "u-boot.bin" is a raw binary image 4668- "u-boot" is an image in ELF binary format 4669- "u-boot.srec" is in Motorola S-Record format 4670 4671By default the build is performed locally and the objects are saved 4672in the source directory. One of the two methods can be used to change 4673this behavior and build U-Boot to some external directory: 4674 46751. Add O= to the make command line invocations: 4676 4677 make O=/tmp/build distclean 4678 make O=/tmp/build NAME_defconfig 4679 make O=/tmp/build all 4680 46812. Set environment variable KBUILD_OUTPUT to point to the desired location: 4682 4683 export KBUILD_OUTPUT=/tmp/build 4684 make distclean 4685 make NAME_defconfig 4686 make all 4687 4688Note that the command line "O=" setting overrides the KBUILD_OUTPUT environment 4689variable. 4690 4691 4692Please be aware that the Makefiles assume you are using GNU make, so 4693for instance on NetBSD you might need to use "gmake" instead of 4694native "make". 4695 4696 4697If the system board that you have is not listed, then you will need 4698to port U-Boot to your hardware platform. To do this, follow these 4699steps: 4700 47011. Create a new directory to hold your board specific code. Add any 4702 files you need. In your board directory, you will need at least 4703 the "Makefile" and a "<board>.c". 47042. Create a new configuration file "include/configs/<board>.h" for 4705 your board. 47063. If you're porting U-Boot to a new CPU, then also create a new 4707 directory to hold your CPU specific code. Add any files you need. 47084. Run "make <board>_defconfig" with your new name. 47095. Type "make", and you should get a working "u-boot.srec" file 4710 to be installed on your target system. 47116. Debug and solve any problems that might arise. 4712 [Of course, this last step is much harder than it sounds.] 4713 4714 4715Testing of U-Boot Modifications, Ports to New Hardware, etc.: 4716============================================================== 4717 4718If you have modified U-Boot sources (for instance added a new board 4719or support for new devices, a new CPU, etc.) you are expected to 4720provide feedback to the other developers. The feedback normally takes 4721the form of a "patch", i. e. a context diff against a certain (latest 4722official or latest in the git repository) version of U-Boot sources. 4723 4724But before you submit such a patch, please verify that your modifi- 4725cation did not break existing code. At least make sure that *ALL* of 4726the supported boards compile WITHOUT ANY compiler warnings. To do so, 4727just run the buildman script (tools/buildman/buildman), which will 4728configure and build U-Boot for ALL supported system. Be warned, this 4729will take a while. Please see the buildman README, or run 'buildman -H' 4730for documentation. 4731 4732 4733See also "U-Boot Porting Guide" below. 4734 4735 4736Monitor Commands - Overview: 4737============================ 4738 4739go - start application at address 'addr' 4740run - run commands in an environment variable 4741bootm - boot application image from memory 4742bootp - boot image via network using BootP/TFTP protocol 4743bootz - boot zImage from memory 4744tftpboot- boot image via network using TFTP protocol 4745 and env variables "ipaddr" and "serverip" 4746 (and eventually "gatewayip") 4747tftpput - upload a file via network using TFTP protocol 4748rarpboot- boot image via network using RARP/TFTP protocol 4749diskboot- boot from IDE devicebootd - boot default, i.e., run 'bootcmd' 4750loads - load S-Record file over serial line 4751loadb - load binary file over serial line (kermit mode) 4752md - memory display 4753mm - memory modify (auto-incrementing) 4754nm - memory modify (constant address) 4755mw - memory write (fill) 4756cp - memory copy 4757cmp - memory compare 4758crc32 - checksum calculation 4759i2c - I2C sub-system 4760sspi - SPI utility commands 4761base - print or set address offset 4762printenv- print environment variables 4763setenv - set environment variables 4764saveenv - save environment variables to persistent storage 4765protect - enable or disable FLASH write protection 4766erase - erase FLASH memory 4767flinfo - print FLASH memory information 4768nand - NAND memory operations (see doc/README.nand) 4769bdinfo - print Board Info structure 4770iminfo - print header information for application image 4771coninfo - print console devices and informations 4772ide - IDE sub-system 4773loop - infinite loop on address range 4774loopw - infinite write loop on address range 4775mtest - simple RAM test 4776icache - enable or disable instruction cache 4777dcache - enable or disable data cache 4778reset - Perform RESET of the CPU 4779echo - echo args to console 4780version - print monitor version 4781help - print online help 4782? - alias for 'help' 4783 4784 4785Monitor Commands - Detailed Description: 4786======================================== 4787 4788TODO. 4789 4790For now: just type "help <command>". 4791 4792 4793Environment Variables: 4794====================== 4795 4796U-Boot supports user configuration using Environment Variables which 4797can be made persistent by saving to Flash memory. 4798 4799Environment Variables are set using "setenv", printed using 4800"printenv", and saved to Flash using "saveenv". Using "setenv" 4801without a value can be used to delete a variable from the 4802environment. As long as you don't save the environment you are 4803working with an in-memory copy. In case the Flash area containing the 4804environment is erased by accident, a default environment is provided. 4805 4806Some configuration options can be set using Environment Variables. 4807 4808List of environment variables (most likely not complete): 4809 4810 baudrate - see CONFIG_BAUDRATE 4811 4812 bootdelay - see CONFIG_BOOTDELAY 4813 4814 bootcmd - see CONFIG_BOOTCOMMAND 4815 4816 bootargs - Boot arguments when booting an RTOS image 4817 4818 bootfile - Name of the image to load with TFTP 4819 4820 bootm_low - Memory range available for image processing in the bootm 4821 command can be restricted. This variable is given as 4822 a hexadecimal number and defines lowest address allowed 4823 for use by the bootm command. See also "bootm_size" 4824 environment variable. Address defined by "bootm_low" is 4825 also the base of the initial memory mapping for the Linux 4826 kernel -- see the description of CONFIG_SYS_BOOTMAPSZ and 4827 bootm_mapsize. 4828 4829 bootm_mapsize - Size of the initial memory mapping for the Linux kernel. 4830 This variable is given as a hexadecimal number and it 4831 defines the size of the memory region starting at base 4832 address bootm_low that is accessible by the Linux kernel 4833 during early boot. If unset, CONFIG_SYS_BOOTMAPSZ is used 4834 as the default value if it is defined, and bootm_size is 4835 used otherwise. 4836 4837 bootm_size - Memory range available for image processing in the bootm 4838 command can be restricted. This variable is given as 4839 a hexadecimal number and defines the size of the region 4840 allowed for use by the bootm command. See also "bootm_low" 4841 environment variable. 4842 4843 updatefile - Location of the software update file on a TFTP server, used 4844 by the automatic software update feature. Please refer to 4845 documentation in doc/README.update for more details. 4846 4847 autoload - if set to "no" (any string beginning with 'n'), 4848 "bootp" will just load perform a lookup of the 4849 configuration from the BOOTP server, but not try to 4850 load any image using TFTP 4851 4852 autostart - if set to "yes", an image loaded using the "bootp", 4853 "rarpboot", "tftpboot" or "diskboot" commands will 4854 be automatically started (by internally calling 4855 "bootm") 4856 4857 If set to "no", a standalone image passed to the 4858 "bootm" command will be copied to the load address 4859 (and eventually uncompressed), but NOT be started. 4860 This can be used to load and uncompress arbitrary 4861 data. 4862 4863 fdt_high - if set this restricts the maximum address that the 4864 flattened device tree will be copied into upon boot. 4865 For example, if you have a system with 1 GB memory 4866 at physical address 0x10000000, while Linux kernel 4867 only recognizes the first 704 MB as low memory, you 4868 may need to set fdt_high as 0x3C000000 to have the 4869 device tree blob be copied to the maximum address 4870 of the 704 MB low memory, so that Linux kernel can 4871 access it during the boot procedure. 4872 4873 If this is set to the special value 0xFFFFFFFF then 4874 the fdt will not be copied at all on boot. For this 4875 to work it must reside in writable memory, have 4876 sufficient padding on the end of it for u-boot to 4877 add the information it needs into it, and the memory 4878 must be accessible by the kernel. 4879 4880 fdtcontroladdr- if set this is the address of the control flattened 4881 device tree used by U-Boot when CONFIG_OF_CONTROL is 4882 defined. 4883 4884 i2cfast - (PPC405GP|PPC405EP only) 4885 if set to 'y' configures Linux I2C driver for fast 4886 mode (400kHZ). This environment variable is used in 4887 initialization code. So, for changes to be effective 4888 it must be saved and board must be reset. 4889 4890 initrd_high - restrict positioning of initrd images: 4891 If this variable is not set, initrd images will be 4892 copied to the highest possible address in RAM; this 4893 is usually what you want since it allows for 4894 maximum initrd size. If for some reason you want to 4895 make sure that the initrd image is loaded below the 4896 CONFIG_SYS_BOOTMAPSZ limit, you can set this environment 4897 variable to a value of "no" or "off" or "0". 4898 Alternatively, you can set it to a maximum upper 4899 address to use (U-Boot will still check that it 4900 does not overwrite the U-Boot stack and data). 4901 4902 For instance, when you have a system with 16 MB 4903 RAM, and want to reserve 4 MB from use by Linux, 4904 you can do this by adding "mem=12M" to the value of 4905 the "bootargs" variable. However, now you must make 4906 sure that the initrd image is placed in the first 4907 12 MB as well - this can be done with 4908 4909 setenv initrd_high 00c00000 4910 4911 If you set initrd_high to 0xFFFFFFFF, this is an 4912 indication to U-Boot that all addresses are legal 4913 for the Linux kernel, including addresses in flash 4914 memory. In this case U-Boot will NOT COPY the 4915 ramdisk at all. This may be useful to reduce the 4916 boot time on your system, but requires that this 4917 feature is supported by your Linux kernel. 4918 4919 ipaddr - IP address; needed for tftpboot command 4920 4921 loadaddr - Default load address for commands like "bootp", 4922 "rarpboot", "tftpboot", "loadb" or "diskboot" 4923 4924 loads_echo - see CONFIG_LOADS_ECHO 4925 4926 serverip - TFTP server IP address; needed for tftpboot command 4927 4928 bootretry - see CONFIG_BOOT_RETRY_TIME 4929 4930 bootdelaykey - see CONFIG_AUTOBOOT_DELAY_STR 4931 4932 bootstopkey - see CONFIG_AUTOBOOT_STOP_STR 4933 4934 ethprime - controls which interface is used first. 4935 4936 ethact - controls which interface is currently active. 4937 For example you can do the following 4938 4939 => setenv ethact FEC 4940 => ping 192.168.0.1 # traffic sent on FEC 4941 => setenv ethact SCC 4942 => ping 10.0.0.1 # traffic sent on SCC 4943 4944 ethrotate - When set to "no" U-Boot does not go through all 4945 available network interfaces. 4946 It just stays at the currently selected interface. 4947 4948 netretry - When set to "no" each network operation will 4949 either succeed or fail without retrying. 4950 When set to "once" the network operation will 4951 fail when all the available network interfaces 4952 are tried once without success. 4953 Useful on scripts which control the retry operation 4954 themselves. 4955 4956 npe_ucode - set load address for the NPE microcode 4957 4958 silent_linux - If set then Linux will be told to boot silently, by 4959 changing the console to be empty. If "yes" it will be 4960 made silent. If "no" it will not be made silent. If 4961 unset, then it will be made silent if the U-Boot console 4962 is silent. 4963 4964 tftpsrcp - If this is set, the value is used for TFTP's 4965 UDP source port. 4966 4967 tftpdstp - If this is set, the value is used for TFTP's UDP 4968 destination port instead of the Well Know Port 69. 4969 4970 tftpblocksize - Block size to use for TFTP transfers; if not set, 4971 we use the TFTP server's default block size 4972 4973 tftptimeout - Retransmission timeout for TFTP packets (in milli- 4974 seconds, minimum value is 1000 = 1 second). Defines 4975 when a packet is considered to be lost so it has to 4976 be retransmitted. The default is 5000 = 5 seconds. 4977 Lowering this value may make downloads succeed 4978 faster in networks with high packet loss rates or 4979 with unreliable TFTP servers. 4980 4981 tftptimeoutcountmax - maximum count of TFTP timeouts (no 4982 unit, minimum value = 0). Defines how many timeouts 4983 can happen during a single file transfer before that 4984 transfer is aborted. The default is 10, and 0 means 4985 'no timeouts allowed'. Increasing this value may help 4986 downloads succeed with high packet loss rates, or with 4987 unreliable TFTP servers or client hardware. 4988 4989 vlan - When set to a value < 4095 the traffic over 4990 Ethernet is encapsulated/received over 802.1q 4991 VLAN tagged frames. 4992 4993 bootpretryperiod - Period during which BOOTP/DHCP sends retries. 4994 Unsigned value, in milliseconds. If not set, the period will 4995 be either the default (28000), or a value based on 4996 CONFIG_NET_RETRY_COUNT, if defined. This value has 4997 precedence over the valu based on CONFIG_NET_RETRY_COUNT. 4998 4999The following image location variables contain the location of images 5000used in booting. The "Image" column gives the role of the image and is 5001not an environment variable name. The other columns are environment 5002variable names. "File Name" gives the name of the file on a TFTP 5003server, "RAM Address" gives the location in RAM the image will be 5004loaded to, and "Flash Location" gives the image's address in NOR 5005flash or offset in NAND flash. 5006 5007*Note* - these variables don't have to be defined for all boards, some 5008boards currently use other variables for these purposes, and some 5009boards use these variables for other purposes. 5010 5011Image File Name RAM Address Flash Location 5012----- --------- ----------- -------------- 5013u-boot u-boot u-boot_addr_r u-boot_addr 5014Linux kernel bootfile kernel_addr_r kernel_addr 5015device tree blob fdtfile fdt_addr_r fdt_addr 5016ramdisk ramdiskfile ramdisk_addr_r ramdisk_addr 5017 5018The following environment variables may be used and automatically 5019updated by the network boot commands ("bootp" and "rarpboot"), 5020depending the information provided by your boot server: 5021 5022 bootfile - see above 5023 dnsip - IP address of your Domain Name Server 5024 dnsip2 - IP address of your secondary Domain Name Server 5025 gatewayip - IP address of the Gateway (Router) to use 5026 hostname - Target hostname 5027 ipaddr - see above 5028 netmask - Subnet Mask 5029 rootpath - Pathname of the root filesystem on the NFS server 5030 serverip - see above 5031 5032 5033There are two special Environment Variables: 5034 5035 serial# - contains hardware identification information such 5036 as type string and/or serial number 5037 ethaddr - Ethernet address 5038 5039These variables can be set only once (usually during manufacturing of 5040the board). U-Boot refuses to delete or overwrite these variables 5041once they have been set once. 5042 5043 5044Further special Environment Variables: 5045 5046 ver - Contains the U-Boot version string as printed 5047 with the "version" command. This variable is 5048 readonly (see CONFIG_VERSION_VARIABLE). 5049 5050 5051Please note that changes to some configuration parameters may take 5052only effect after the next boot (yes, that's just like Windoze :-). 5053 5054 5055Callback functions for environment variables: 5056--------------------------------------------- 5057 5058For some environment variables, the behavior of u-boot needs to change 5059when their values are changed. This functionality allows functions to 5060be associated with arbitrary variables. On creation, overwrite, or 5061deletion, the callback will provide the opportunity for some side 5062effect to happen or for the change to be rejected. 5063 5064The callbacks are named and associated with a function using the 5065U_BOOT_ENV_CALLBACK macro in your board or driver code. 5066 5067These callbacks are associated with variables in one of two ways. The 5068static list can be added to by defining CONFIG_ENV_CALLBACK_LIST_STATIC 5069in the board configuration to a string that defines a list of 5070associations. The list must be in the following format: 5071 5072 entry = variable_name[:callback_name] 5073 list = entry[,list] 5074 5075If the callback name is not specified, then the callback is deleted. 5076Spaces are also allowed anywhere in the list. 5077 5078Callbacks can also be associated by defining the ".callbacks" variable 5079with the same list format above. Any association in ".callbacks" will 5080override any association in the static list. You can define 5081CONFIG_ENV_CALLBACK_LIST_DEFAULT to a list (string) to define the 5082".callbacks" environment variable in the default or embedded environment. 5083 5084If CONFIG_REGEX is defined, the variable_name above is evaluated as a 5085regular expression. This allows multiple variables to be connected to 5086the same callback without explicitly listing them all out. 5087 5088 5089Command Line Parsing: 5090===================== 5091 5092There are two different command line parsers available with U-Boot: 5093the old "simple" one, and the much more powerful "hush" shell: 5094 5095Old, simple command line parser: 5096-------------------------------- 5097 5098- supports environment variables (through setenv / saveenv commands) 5099- several commands on one line, separated by ';' 5100- variable substitution using "... ${name} ..." syntax 5101- special characters ('$', ';') can be escaped by prefixing with '\', 5102 for example: 5103 setenv bootcmd bootm \${address} 5104- You can also escape text by enclosing in single apostrophes, for example: 5105 setenv addip 'setenv bootargs $bootargs ip=$ipaddr:$serverip:$gatewayip:$netmask:$hostname::off' 5106 5107Hush shell: 5108----------- 5109 5110- similar to Bourne shell, with control structures like 5111 if...then...else...fi, for...do...done; while...do...done, 5112 until...do...done, ... 5113- supports environment ("global") variables (through setenv / saveenv 5114 commands) and local shell variables (through standard shell syntax 5115 "name=value"); only environment variables can be used with "run" 5116 command 5117 5118General rules: 5119-------------- 5120 5121(1) If a command line (or an environment variable executed by a "run" 5122 command) contains several commands separated by semicolon, and 5123 one of these commands fails, then the remaining commands will be 5124 executed anyway. 5125 5126(2) If you execute several variables with one call to run (i. e. 5127 calling run with a list of variables as arguments), any failing 5128 command will cause "run" to terminate, i. e. the remaining 5129 variables are not executed. 5130 5131Note for Redundant Ethernet Interfaces: 5132======================================= 5133 5134Some boards come with redundant Ethernet interfaces; U-Boot supports 5135such configurations and is capable of automatic selection of a 5136"working" interface when needed. MAC assignment works as follows: 5137 5138Network interfaces are numbered eth0, eth1, eth2, ... Corresponding 5139MAC addresses can be stored in the environment as "ethaddr" (=>eth0), 5140"eth1addr" (=>eth1), "eth2addr", ... 5141 5142If the network interface stores some valid MAC address (for instance 5143in SROM), this is used as default address if there is NO correspon- 5144ding setting in the environment; if the corresponding environment 5145variable is set, this overrides the settings in the card; that means: 5146 5147o If the SROM has a valid MAC address, and there is no address in the 5148 environment, the SROM's address is used. 5149 5150o If there is no valid address in the SROM, and a definition in the 5151 environment exists, then the value from the environment variable is 5152 used. 5153 5154o If both the SROM and the environment contain a MAC address, and 5155 both addresses are the same, this MAC address is used. 5156 5157o If both the SROM and the environment contain a MAC address, and the 5158 addresses differ, the value from the environment is used and a 5159 warning is printed. 5160 5161o If neither SROM nor the environment contain a MAC address, an error 5162 is raised. If CONFIG_NET_RANDOM_ETHADDR is defined, then in this case 5163 a random, locally-assigned MAC is used. 5164 5165If Ethernet drivers implement the 'write_hwaddr' function, valid MAC addresses 5166will be programmed into hardware as part of the initialization process. This 5167may be skipped by setting the appropriate 'ethmacskip' environment variable. 5168The naming convention is as follows: 5169"ethmacskip" (=>eth0), "eth1macskip" (=>eth1) etc. 5170 5171Image Formats: 5172============== 5173 5174U-Boot is capable of booting (and performing other auxiliary operations on) 5175images in two formats: 5176 5177New uImage format (FIT) 5178----------------------- 5179 5180Flexible and powerful format based on Flattened Image Tree -- FIT (similar 5181to Flattened Device Tree). It allows the use of images with multiple 5182components (several kernels, ramdisks, etc.), with contents protected by 5183SHA1, MD5 or CRC32. More details are found in the doc/uImage.FIT directory. 5184 5185 5186Old uImage format 5187----------------- 5188 5189Old image format is based on binary files which can be basically anything, 5190preceded by a special header; see the definitions in include/image.h for 5191details; basically, the header defines the following image properties: 5192 5193* Target Operating System (Provisions for OpenBSD, NetBSD, FreeBSD, 5194 4.4BSD, Linux, SVR4, Esix, Solaris, Irix, SCO, Dell, NCR, VxWorks, 5195 LynxOS, pSOS, QNX, RTEMS, INTEGRITY; 5196 Currently supported: Linux, NetBSD, VxWorks, QNX, RTEMS, LynxOS, 5197 INTEGRITY). 5198* Target CPU Architecture (Provisions for Alpha, ARM, AVR32, Intel x86, 5199 IA64, MIPS, NDS32, Nios II, PowerPC, IBM S390, SuperH, Sparc, Sparc 64 Bit; 5200 Currently supported: ARM, AVR32, Intel x86, MIPS, NDS32, Nios II, PowerPC). 5201* Compression Type (uncompressed, gzip, bzip2) 5202* Load Address 5203* Entry Point 5204* Image Name 5205* Image Timestamp 5206 5207The header is marked by a special Magic Number, and both the header 5208and the data portions of the image are secured against corruption by 5209CRC32 checksums. 5210 5211 5212Linux Support: 5213============== 5214 5215Although U-Boot should support any OS or standalone application 5216easily, the main focus has always been on Linux during the design of 5217U-Boot. 5218 5219U-Boot includes many features that so far have been part of some 5220special "boot loader" code within the Linux kernel. Also, any 5221"initrd" images to be used are no longer part of one big Linux image; 5222instead, kernel and "initrd" are separate images. This implementation 5223serves several purposes: 5224 5225- the same features can be used for other OS or standalone 5226 applications (for instance: using compressed images to reduce the 5227 Flash memory footprint) 5228 5229- it becomes much easier to port new Linux kernel versions because 5230 lots of low-level, hardware dependent stuff are done by U-Boot 5231 5232- the same Linux kernel image can now be used with different "initrd" 5233 images; of course this also means that different kernel images can 5234 be run with the same "initrd". This makes testing easier (you don't 5235 have to build a new "zImage.initrd" Linux image when you just 5236 change a file in your "initrd"). Also, a field-upgrade of the 5237 software is easier now. 5238 5239 5240Linux HOWTO: 5241============ 5242 5243Porting Linux to U-Boot based systems: 5244--------------------------------------- 5245 5246U-Boot cannot save you from doing all the necessary modifications to 5247configure the Linux device drivers for use with your target hardware 5248(no, we don't intend to provide a full virtual machine interface to 5249Linux :-). 5250 5251But now you can ignore ALL boot loader code (in arch/powerpc/mbxboot). 5252 5253Just make sure your machine specific header file (for instance 5254include/asm-ppc/tqm8xx.h) includes the same definition of the Board 5255Information structure as we define in include/asm-<arch>/u-boot.h, 5256and make sure that your definition of IMAP_ADDR uses the same value 5257as your U-Boot configuration in CONFIG_SYS_IMMR. 5258 5259Note that U-Boot now has a driver model, a unified model for drivers. 5260If you are adding a new driver, plumb it into driver model. If there 5261is no uclass available, you are encouraged to create one. See 5262doc/driver-model. 5263 5264 5265Configuring the Linux kernel: 5266----------------------------- 5267 5268No specific requirements for U-Boot. Make sure you have some root 5269device (initial ramdisk, NFS) for your target system. 5270 5271 5272Building a Linux Image: 5273----------------------- 5274 5275With U-Boot, "normal" build targets like "zImage" or "bzImage" are 5276not used. If you use recent kernel source, a new build target 5277"uImage" will exist which automatically builds an image usable by 5278U-Boot. Most older kernels also have support for a "pImage" target, 5279which was introduced for our predecessor project PPCBoot and uses a 5280100% compatible format. 5281 5282Example: 5283 5284 make TQM850L_defconfig 5285 make oldconfig 5286 make dep 5287 make uImage 5288 5289The "uImage" build target uses a special tool (in 'tools/mkimage') to 5290encapsulate a compressed Linux kernel image with header information, 5291CRC32 checksum etc. for use with U-Boot. This is what we are doing: 5292 5293* build a standard "vmlinux" kernel image (in ELF binary format): 5294 5295* convert the kernel into a raw binary image: 5296 5297 ${CROSS_COMPILE}-objcopy -O binary \ 5298 -R .note -R .comment \ 5299 -S vmlinux linux.bin 5300 5301* compress the binary image: 5302 5303 gzip -9 linux.bin 5304 5305* package compressed binary image for U-Boot: 5306 5307 mkimage -A ppc -O linux -T kernel -C gzip \ 5308 -a 0 -e 0 -n "Linux Kernel Image" \ 5309 -d linux.bin.gz uImage 5310 5311 5312The "mkimage" tool can also be used to create ramdisk images for use 5313with U-Boot, either separated from the Linux kernel image, or 5314combined into one file. "mkimage" encapsulates the images with a 64 5315byte header containing information about target architecture, 5316operating system, image type, compression method, entry points, time 5317stamp, CRC32 checksums, etc. 5318 5319"mkimage" can be called in two ways: to verify existing images and 5320print the header information, or to build new images. 5321 5322In the first form (with "-l" option) mkimage lists the information 5323contained in the header of an existing U-Boot image; this includes 5324checksum verification: 5325 5326 tools/mkimage -l image 5327 -l ==> list image header information 5328 5329The second form (with "-d" option) is used to build a U-Boot image 5330from a "data file" which is used as image payload: 5331 5332 tools/mkimage -A arch -O os -T type -C comp -a addr -e ep \ 5333 -n name -d data_file image 5334 -A ==> set architecture to 'arch' 5335 -O ==> set operating system to 'os' 5336 -T ==> set image type to 'type' 5337 -C ==> set compression type 'comp' 5338 -a ==> set load address to 'addr' (hex) 5339 -e ==> set entry point to 'ep' (hex) 5340 -n ==> set image name to 'name' 5341 -d ==> use image data from 'datafile' 5342 5343Right now, all Linux kernels for PowerPC systems use the same load 5344address (0x00000000), but the entry point address depends on the 5345kernel version: 5346 5347- 2.2.x kernels have the entry point at 0x0000000C, 5348- 2.3.x and later kernels have the entry point at 0x00000000. 5349 5350So a typical call to build a U-Boot image would read: 5351 5352 -> tools/mkimage -n '2.4.4 kernel for TQM850L' \ 5353 > -A ppc -O linux -T kernel -C gzip -a 0 -e 0 \ 5354 > -d /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/powerpc/coffboot/vmlinux.gz \ 5355 > examples/uImage.TQM850L 5356 Image Name: 2.4.4 kernel for TQM850L 5357 Created: Wed Jul 19 02:34:59 2000 5358 Image Type: PowerPC Linux Kernel Image (gzip compressed) 5359 Data Size: 335725 Bytes = 327.86 kB = 0.32 MB 5360 Load Address: 0x00000000 5361 Entry Point: 0x00000000 5362 5363To verify the contents of the image (or check for corruption): 5364 5365 -> tools/mkimage -l examples/uImage.TQM850L 5366 Image Name: 2.4.4 kernel for TQM850L 5367 Created: Wed Jul 19 02:34:59 2000 5368 Image Type: PowerPC Linux Kernel Image (gzip compressed) 5369 Data Size: 335725 Bytes = 327.86 kB = 0.32 MB 5370 Load Address: 0x00000000 5371 Entry Point: 0x00000000 5372 5373NOTE: for embedded systems where boot time is critical you can trade 5374speed for memory and install an UNCOMPRESSED image instead: this 5375needs more space in Flash, but boots much faster since it does not 5376need to be uncompressed: 5377 5378 -> gunzip /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/powerpc/coffboot/vmlinux.gz 5379 -> tools/mkimage -n '2.4.4 kernel for TQM850L' \ 5380 > -A ppc -O linux -T kernel -C none -a 0 -e 0 \ 5381 > -d /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/powerpc/coffboot/vmlinux \ 5382 > examples/uImage.TQM850L-uncompressed 5383 Image Name: 2.4.4 kernel for TQM850L 5384 Created: Wed Jul 19 02:34:59 2000 5385 Image Type: PowerPC Linux Kernel Image (uncompressed) 5386 Data Size: 792160 Bytes = 773.59 kB = 0.76 MB 5387 Load Address: 0x00000000 5388 Entry Point: 0x00000000 5389 5390 5391Similar you can build U-Boot images from a 'ramdisk.image.gz' file 5392when your kernel is intended to use an initial ramdisk: 5393 5394 -> tools/mkimage -n 'Simple Ramdisk Image' \ 5395 > -A ppc -O linux -T ramdisk -C gzip \ 5396 > -d /LinuxPPC/images/SIMPLE-ramdisk.image.gz examples/simple-initrd 5397 Image Name: Simple Ramdisk Image 5398 Created: Wed Jan 12 14:01:50 2000 5399 Image Type: PowerPC Linux RAMDisk Image (gzip compressed) 5400 Data Size: 566530 Bytes = 553.25 kB = 0.54 MB 5401 Load Address: 0x00000000 5402 Entry Point: 0x00000000 5403 5404The "dumpimage" is a tool to disassemble images built by mkimage. Its "-i" 5405option performs the converse operation of the mkimage's second form (the "-d" 5406option). Given an image built by mkimage, the dumpimage extracts a "data file" 5407from the image: 5408 5409 tools/dumpimage -i image -T type -p position data_file 5410 -i ==> extract from the 'image' a specific 'data_file' 5411 -T ==> set image type to 'type' 5412 -p ==> 'position' (starting at 0) of the 'data_file' inside the 'image' 5413 5414 5415Installing a Linux Image: 5416------------------------- 5417 5418To downloading a U-Boot image over the serial (console) interface, 5419you must convert the image to S-Record format: 5420 5421 objcopy -I binary -O srec examples/image examples/image.srec 5422 5423The 'objcopy' does not understand the information in the U-Boot 5424image header, so the resulting S-Record file will be relative to 5425address 0x00000000. To load it to a given address, you need to 5426specify the target address as 'offset' parameter with the 'loads' 5427command. 5428 5429Example: install the image to address 0x40100000 (which on the 5430TQM8xxL is in the first Flash bank): 5431 5432 => erase 40100000 401FFFFF 5433 5434 .......... done 5435 Erased 8 sectors 5436 5437 => loads 40100000 5438 ## Ready for S-Record download ... 5439 ~>examples/image.srec 5440 1 2 3 4 5 6 7 8 9 10 11 12 13 ... 5441 ... 5442 15989 15990 15991 15992 5443 [file transfer complete] 5444 [connected] 5445 ## Start Addr = 0x00000000 5446 5447 5448You can check the success of the download using the 'iminfo' command; 5449this includes a checksum verification so you can be sure no data 5450corruption happened: 5451 5452 => imi 40100000 5453 5454 ## Checking Image at 40100000 ... 5455 Image Name: 2.2.13 for initrd on TQM850L 5456 Image Type: PowerPC Linux Kernel Image (gzip compressed) 5457 Data Size: 335725 Bytes = 327 kB = 0 MB 5458 Load Address: 00000000 5459 Entry Point: 0000000c 5460 Verifying Checksum ... OK 5461 5462 5463Boot Linux: 5464----------- 5465 5466The "bootm" command is used to boot an application that is stored in 5467memory (RAM or Flash). In case of a Linux kernel image, the contents 5468of the "bootargs" environment variable is passed to the kernel as 5469parameters. You can check and modify this variable using the 5470"printenv" and "setenv" commands: 5471 5472 5473 => printenv bootargs 5474 bootargs=root=/dev/ram 5475 5476 => setenv bootargs root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2 5477 5478 => printenv bootargs 5479 bootargs=root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2 5480 5481 => bootm 40020000 5482 ## Booting Linux kernel at 40020000 ... 5483 Image Name: 2.2.13 for NFS on TQM850L 5484 Image Type: PowerPC Linux Kernel Image (gzip compressed) 5485 Data Size: 381681 Bytes = 372 kB = 0 MB 5486 Load Address: 00000000 5487 Entry Point: 0000000c 5488 Verifying Checksum ... OK 5489 Uncompressing Kernel Image ... OK 5490 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 5491 Boot arguments: root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2 5492 time_init: decrementer frequency = 187500000/60 5493 Calibrating delay loop... 49.77 BogoMIPS 5494 Memory: 15208k available (700k kernel code, 444k data, 32k init) [c0000000,c1000000] 5495 ... 5496 5497If you want to boot a Linux kernel with initial RAM disk, you pass 5498the memory addresses of both the kernel and the initrd image (PPBCOOT 5499format!) to the "bootm" command: 5500 5501 => imi 40100000 40200000 5502 5503 ## Checking Image at 40100000 ... 5504 Image Name: 2.2.13 for initrd on TQM850L 5505 Image Type: PowerPC Linux Kernel Image (gzip compressed) 5506 Data Size: 335725 Bytes = 327 kB = 0 MB 5507 Load Address: 00000000 5508 Entry Point: 0000000c 5509 Verifying Checksum ... OK 5510 5511 ## Checking Image at 40200000 ... 5512 Image Name: Simple Ramdisk Image 5513 Image Type: PowerPC Linux RAMDisk Image (gzip compressed) 5514 Data Size: 566530 Bytes = 553 kB = 0 MB 5515 Load Address: 00000000 5516 Entry Point: 00000000 5517 Verifying Checksum ... OK 5518 5519 => bootm 40100000 40200000 5520 ## Booting Linux kernel at 40100000 ... 5521 Image Name: 2.2.13 for initrd on TQM850L 5522 Image Type: PowerPC Linux Kernel Image (gzip compressed) 5523 Data Size: 335725 Bytes = 327 kB = 0 MB 5524 Load Address: 00000000 5525 Entry Point: 0000000c 5526 Verifying Checksum ... OK 5527 Uncompressing Kernel Image ... OK 5528 ## Loading RAMDisk Image at 40200000 ... 5529 Image Name: Simple Ramdisk Image 5530 Image Type: PowerPC Linux RAMDisk Image (gzip compressed) 5531 Data Size: 566530 Bytes = 553 kB = 0 MB 5532 Load Address: 00000000 5533 Entry Point: 00000000 5534 Verifying Checksum ... OK 5535 Loading Ramdisk ... OK 5536 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 5537 Boot arguments: root=/dev/ram 5538 time_init: decrementer frequency = 187500000/60 5539 Calibrating delay loop... 49.77 BogoMIPS 5540 ... 5541 RAMDISK: Compressed image found at block 0 5542 VFS: Mounted root (ext2 filesystem). 5543 5544 bash# 5545 5546Boot Linux and pass a flat device tree: 5547----------- 5548 5549First, U-Boot must be compiled with the appropriate defines. See the section 5550titled "Linux Kernel Interface" above for a more in depth explanation. The 5551following is an example of how to start a kernel and pass an updated 5552flat device tree: 5553 5554=> print oftaddr 5555oftaddr=0x300000 5556=> print oft 5557oft=oftrees/mpc8540ads.dtb 5558=> tftp $oftaddr $oft 5559Speed: 1000, full duplex 5560Using TSEC0 device 5561TFTP from server 192.168.1.1; our IP address is 192.168.1.101 5562Filename 'oftrees/mpc8540ads.dtb'. 5563Load address: 0x300000 5564Loading: # 5565done 5566Bytes transferred = 4106 (100a hex) 5567=> tftp $loadaddr $bootfile 5568Speed: 1000, full duplex 5569Using TSEC0 device 5570TFTP from server 192.168.1.1; our IP address is 192.168.1.2 5571Filename 'uImage'. 5572Load address: 0x200000 5573Loading:############ 5574done 5575Bytes transferred = 1029407 (fb51f hex) 5576=> print loadaddr 5577loadaddr=200000 5578=> print oftaddr 5579oftaddr=0x300000 5580=> bootm $loadaddr - $oftaddr 5581## Booting image at 00200000 ... 5582 Image Name: Linux-2.6.17-dirty 5583 Image Type: PowerPC Linux Kernel Image (gzip compressed) 5584 Data Size: 1029343 Bytes = 1005.2 kB 5585 Load Address: 00000000 5586 Entry Point: 00000000 5587 Verifying Checksum ... OK 5588 Uncompressing Kernel Image ... OK 5589Booting using flat device tree at 0x300000 5590Using MPC85xx ADS machine description 5591Memory CAM mapping: CAM0=256Mb, CAM1=256Mb, CAM2=0Mb residual: 0Mb 5592[snip] 5593 5594 5595More About U-Boot Image Types: 5596------------------------------ 5597 5598U-Boot supports the following image types: 5599 5600 "Standalone Programs" are directly runnable in the environment 5601 provided by U-Boot; it is expected that (if they behave 5602 well) you can continue to work in U-Boot after return from 5603 the Standalone Program. 5604 "OS Kernel Images" are usually images of some Embedded OS which 5605 will take over control completely. Usually these programs 5606 will install their own set of exception handlers, device 5607 drivers, set up the MMU, etc. - this means, that you cannot 5608 expect to re-enter U-Boot except by resetting the CPU. 5609 "RAMDisk Images" are more or less just data blocks, and their 5610 parameters (address, size) are passed to an OS kernel that is 5611 being started. 5612 "Multi-File Images" contain several images, typically an OS 5613 (Linux) kernel image and one or more data images like 5614 RAMDisks. This construct is useful for instance when you want 5615 to boot over the network using BOOTP etc., where the boot 5616 server provides just a single image file, but you want to get 5617 for instance an OS kernel and a RAMDisk image. 5618 5619 "Multi-File Images" start with a list of image sizes, each 5620 image size (in bytes) specified by an "uint32_t" in network 5621 byte order. This list is terminated by an "(uint32_t)0". 5622 Immediately after the terminating 0 follow the images, one by 5623 one, all aligned on "uint32_t" boundaries (size rounded up to 5624 a multiple of 4 bytes). 5625 5626 "Firmware Images" are binary images containing firmware (like 5627 U-Boot or FPGA images) which usually will be programmed to 5628 flash memory. 5629 5630 "Script files" are command sequences that will be executed by 5631 U-Boot's command interpreter; this feature is especially 5632 useful when you configure U-Boot to use a real shell (hush) 5633 as command interpreter. 5634 5635Booting the Linux zImage: 5636------------------------- 5637 5638On some platforms, it's possible to boot Linux zImage. This is done 5639using the "bootz" command. The syntax of "bootz" command is the same 5640as the syntax of "bootm" command. 5641 5642Note, defining the CONFIG_SUPPORT_RAW_INITRD allows user to supply 5643kernel with raw initrd images. The syntax is slightly different, the 5644address of the initrd must be augmented by it's size, in the following 5645format: "<initrd addres>:<initrd size>". 5646 5647 5648Standalone HOWTO: 5649================= 5650 5651One of the features of U-Boot is that you can dynamically load and 5652run "standalone" applications, which can use some resources of 5653U-Boot like console I/O functions or interrupt services. 5654 5655Two simple examples are included with the sources: 5656 5657"Hello World" Demo: 5658------------------- 5659 5660'examples/hello_world.c' contains a small "Hello World" Demo 5661application; it is automatically compiled when you build U-Boot. 5662It's configured to run at address 0x00040004, so you can play with it 5663like that: 5664 5665 => loads 5666 ## Ready for S-Record download ... 5667 ~>examples/hello_world.srec 5668 1 2 3 4 5 6 7 8 9 10 11 ... 5669 [file transfer complete] 5670 [connected] 5671 ## Start Addr = 0x00040004 5672 5673 => go 40004 Hello World! This is a test. 5674 ## Starting application at 0x00040004 ... 5675 Hello World 5676 argc = 7 5677 argv[0] = "40004" 5678 argv[1] = "Hello" 5679 argv[2] = "World!" 5680 argv[3] = "This" 5681 argv[4] = "is" 5682 argv[5] = "a" 5683 argv[6] = "test." 5684 argv[7] = "<NULL>" 5685 Hit any key to exit ... 5686 5687 ## Application terminated, rc = 0x0 5688 5689Another example, which demonstrates how to register a CPM interrupt 5690handler with the U-Boot code, can be found in 'examples/timer.c'. 5691Here, a CPM timer is set up to generate an interrupt every second. 5692The interrupt service routine is trivial, just printing a '.' 5693character, but this is just a demo program. The application can be 5694controlled by the following keys: 5695 5696 ? - print current values og the CPM Timer registers 5697 b - enable interrupts and start timer 5698 e - stop timer and disable interrupts 5699 q - quit application 5700 5701 => loads 5702 ## Ready for S-Record download ... 5703 ~>examples/timer.srec 5704 1 2 3 4 5 6 7 8 9 10 11 ... 5705 [file transfer complete] 5706 [connected] 5707 ## Start Addr = 0x00040004 5708 5709 => go 40004 5710 ## Starting application at 0x00040004 ... 5711 TIMERS=0xfff00980 5712 Using timer 1 5713 tgcr @ 0xfff00980, tmr @ 0xfff00990, trr @ 0xfff00994, tcr @ 0xfff00998, tcn @ 0xfff0099c, ter @ 0xfff009b0 5714 5715Hit 'b': 5716 [q, b, e, ?] Set interval 1000000 us 5717 Enabling timer 5718Hit '?': 5719 [q, b, e, ?] ........ 5720 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0xef6, ter=0x0 5721Hit '?': 5722 [q, b, e, ?] . 5723 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x2ad4, ter=0x0 5724Hit '?': 5725 [q, b, e, ?] . 5726 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x1efc, ter=0x0 5727Hit '?': 5728 [q, b, e, ?] . 5729 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x169d, ter=0x0 5730Hit 'e': 5731 [q, b, e, ?] ...Stopping timer 5732Hit 'q': 5733 [q, b, e, ?] ## Application terminated, rc = 0x0 5734 5735 5736Minicom warning: 5737================ 5738 5739Over time, many people have reported problems when trying to use the 5740"minicom" terminal emulation program for serial download. I (wd) 5741consider minicom to be broken, and recommend not to use it. Under 5742Unix, I recommend to use C-Kermit for general purpose use (and 5743especially for kermit binary protocol download ("loadb" command), and 5744use "cu" for S-Record download ("loads" command). See 5745http://www.denx.de/wiki/view/DULG/SystemSetup#Section_4.3. 5746for help with kermit. 5747 5748 5749Nevertheless, if you absolutely want to use it try adding this 5750configuration to your "File transfer protocols" section: 5751 5752 Name Program Name U/D FullScr IO-Red. Multi 5753 X kermit /usr/bin/kermit -i -l %l -s Y U Y N N 5754 Y kermit /usr/bin/kermit -i -l %l -r N D Y N N 5755 5756 5757NetBSD Notes: 5758============= 5759 5760Starting at version 0.9.2, U-Boot supports NetBSD both as host 5761(build U-Boot) and target system (boots NetBSD/mpc8xx). 5762 5763Building requires a cross environment; it is known to work on 5764NetBSD/i386 with the cross-powerpc-netbsd-1.3 package (you will also 5765need gmake since the Makefiles are not compatible with BSD make). 5766Note that the cross-powerpc package does not install include files; 5767attempting to build U-Boot will fail because <machine/ansi.h> is 5768missing. This file has to be installed and patched manually: 5769 5770 # cd /usr/pkg/cross/powerpc-netbsd/include 5771 # mkdir powerpc 5772 # ln -s powerpc machine 5773 # cp /usr/src/sys/arch/powerpc/include/ansi.h powerpc/ansi.h 5774 # ${EDIT} powerpc/ansi.h ## must remove __va_list, _BSD_VA_LIST 5775 5776Native builds *don't* work due to incompatibilities between native 5777and U-Boot include files. 5778 5779Booting assumes that (the first part of) the image booted is a 5780stage-2 loader which in turn loads and then invokes the kernel 5781proper. Loader sources will eventually appear in the NetBSD source 5782tree (probably in sys/arc/mpc8xx/stand/u-boot_stage2/); in the 5783meantime, see ftp://ftp.denx.de/pub/u-boot/ppcboot_stage2.tar.gz 5784 5785 5786Implementation Internals: 5787========================= 5788 5789The following is not intended to be a complete description of every 5790implementation detail. However, it should help to understand the 5791inner workings of U-Boot and make it easier to port it to custom 5792hardware. 5793 5794 5795Initial Stack, Global Data: 5796--------------------------- 5797 5798The implementation of U-Boot is complicated by the fact that U-Boot 5799starts running out of ROM (flash memory), usually without access to 5800system RAM (because the memory controller is not initialized yet). 5801This means that we don't have writable Data or BSS segments, and BSS 5802is not initialized as zero. To be able to get a C environment working 5803at all, we have to allocate at least a minimal stack. Implementation 5804options for this are defined and restricted by the CPU used: Some CPU 5805models provide on-chip memory (like the IMMR area on MPC8xx and 5806MPC826x processors), on others (parts of) the data cache can be 5807locked as (mis-) used as memory, etc. 5808 5809 Chris Hallinan posted a good summary of these issues to the 5810 U-Boot mailing list: 5811 5812 Subject: RE: [U-Boot-Users] RE: More On Memory Bank x (nothingness)? 5813 From: "Chris Hallinan" <clh@net1plus.com> 5814 Date: Mon, 10 Feb 2003 16:43:46 -0500 (22:43 MET) 5815 ... 5816 5817 Correct me if I'm wrong, folks, but the way I understand it 5818 is this: Using DCACHE as initial RAM for Stack, etc, does not 5819 require any physical RAM backing up the cache. The cleverness 5820 is that the cache is being used as a temporary supply of 5821 necessary storage before the SDRAM controller is setup. It's 5822 beyond the scope of this list to explain the details, but you 5823 can see how this works by studying the cache architecture and 5824 operation in the architecture and processor-specific manuals. 5825 5826 OCM is On Chip Memory, which I believe the 405GP has 4K. It 5827 is another option for the system designer to use as an 5828 initial stack/RAM area prior to SDRAM being available. Either 5829 option should work for you. Using CS 4 should be fine if your 5830 board designers haven't used it for something that would 5831 cause you grief during the initial boot! It is frequently not 5832 used. 5833 5834 CONFIG_SYS_INIT_RAM_ADDR should be somewhere that won't interfere 5835 with your processor/board/system design. The default value 5836 you will find in any recent u-boot distribution in 5837 walnut.h should work for you. I'd set it to a value larger 5838 than your SDRAM module. If you have a 64MB SDRAM module, set 5839 it above 400_0000. Just make sure your board has no resources 5840 that are supposed to respond to that address! That code in 5841 start.S has been around a while and should work as is when 5842 you get the config right. 5843 5844 -Chris Hallinan 5845 DS4.COM, Inc. 5846 5847It is essential to remember this, since it has some impact on the C 5848code for the initialization procedures: 5849 5850* Initialized global data (data segment) is read-only. Do not attempt 5851 to write it. 5852 5853* Do not use any uninitialized global data (or implicitly initialized 5854 as zero data - BSS segment) at all - this is undefined, initiali- 5855 zation is performed later (when relocating to RAM). 5856 5857* Stack space is very limited. Avoid big data buffers or things like 5858 that. 5859 5860Having only the stack as writable memory limits means we cannot use 5861normal global data to share information between the code. But it 5862turned out that the implementation of U-Boot can be greatly 5863simplified by making a global data structure (gd_t) available to all 5864functions. We could pass a pointer to this data as argument to _all_ 5865functions, but this would bloat the code. Instead we use a feature of 5866the GCC compiler (Global Register Variables) to share the data: we 5867place a pointer (gd) to the global data into a register which we 5868reserve for this purpose. 5869 5870When choosing a register for such a purpose we are restricted by the 5871relevant (E)ABI specifications for the current architecture, and by 5872GCC's implementation. 5873 5874For PowerPC, the following registers have specific use: 5875 R1: stack pointer 5876 R2: reserved for system use 5877 R3-R4: parameter passing and return values 5878 R5-R10: parameter passing 5879 R13: small data area pointer 5880 R30: GOT pointer 5881 R31: frame pointer 5882 5883 (U-Boot also uses R12 as internal GOT pointer. r12 5884 is a volatile register so r12 needs to be reset when 5885 going back and forth between asm and C) 5886 5887 ==> U-Boot will use R2 to hold a pointer to the global data 5888 5889 Note: on PPC, we could use a static initializer (since the 5890 address of the global data structure is known at compile time), 5891 but it turned out that reserving a register results in somewhat 5892 smaller code - although the code savings are not that big (on 5893 average for all boards 752 bytes for the whole U-Boot image, 5894 624 text + 127 data). 5895 5896On ARM, the following registers are used: 5897 5898 R0: function argument word/integer result 5899 R1-R3: function argument word 5900 R9: platform specific 5901 R10: stack limit (used only if stack checking is enabled) 5902 R11: argument (frame) pointer 5903 R12: temporary workspace 5904 R13: stack pointer 5905 R14: link register 5906 R15: program counter 5907 5908 ==> U-Boot will use R9 to hold a pointer to the global data 5909 5910 Note: on ARM, only R_ARM_RELATIVE relocations are supported. 5911 5912On Nios II, the ABI is documented here: 5913 http://www.altera.com/literature/hb/nios2/n2cpu_nii51016.pdf 5914 5915 ==> U-Boot will use gp to hold a pointer to the global data 5916 5917 Note: on Nios II, we give "-G0" option to gcc and don't use gp 5918 to access small data sections, so gp is free. 5919 5920On NDS32, the following registers are used: 5921 5922 R0-R1: argument/return 5923 R2-R5: argument 5924 R15: temporary register for assembler 5925 R16: trampoline register 5926 R28: frame pointer (FP) 5927 R29: global pointer (GP) 5928 R30: link register (LP) 5929 R31: stack pointer (SP) 5930 PC: program counter (PC) 5931 5932 ==> U-Boot will use R10 to hold a pointer to the global data 5933 5934NOTE: DECLARE_GLOBAL_DATA_PTR must be used with file-global scope, 5935or current versions of GCC may "optimize" the code too much. 5936 5937Memory Management: 5938------------------ 5939 5940U-Boot runs in system state and uses physical addresses, i.e. the 5941MMU is not used either for address mapping nor for memory protection. 5942 5943The available memory is mapped to fixed addresses using the memory 5944controller. In this process, a contiguous block is formed for each 5945memory type (Flash, SDRAM, SRAM), even when it consists of several 5946physical memory banks. 5947 5948U-Boot is installed in the first 128 kB of the first Flash bank (on 5949TQM8xxL modules this is the range 0x40000000 ... 0x4001FFFF). After 5950booting and sizing and initializing DRAM, the code relocates itself 5951to the upper end of DRAM. Immediately below the U-Boot code some 5952memory is reserved for use by malloc() [see CONFIG_SYS_MALLOC_LEN 5953configuration setting]. Below that, a structure with global Board 5954Info data is placed, followed by the stack (growing downward). 5955 5956Additionally, some exception handler code is copied to the low 8 kB 5957of DRAM (0x00000000 ... 0x00001FFF). 5958 5959So a typical memory configuration with 16 MB of DRAM could look like 5960this: 5961 5962 0x0000 0000 Exception Vector code 5963 : 5964 0x0000 1FFF 5965 0x0000 2000 Free for Application Use 5966 : 5967 : 5968 5969 : 5970 : 5971 0x00FB FF20 Monitor Stack (Growing downward) 5972 0x00FB FFAC Board Info Data and permanent copy of global data 5973 0x00FC 0000 Malloc Arena 5974 : 5975 0x00FD FFFF 5976 0x00FE 0000 RAM Copy of Monitor Code 5977 ... eventually: LCD or video framebuffer 5978 ... eventually: pRAM (Protected RAM - unchanged by reset) 5979 0x00FF FFFF [End of RAM] 5980 5981 5982System Initialization: 5983---------------------- 5984 5985In the reset configuration, U-Boot starts at the reset entry point 5986(on most PowerPC systems at address 0x00000100). Because of the reset 5987configuration for CS0# this is a mirror of the on board Flash memory. 5988To be able to re-map memory U-Boot then jumps to its link address. 5989To be able to implement the initialization code in C, a (small!) 5990initial stack is set up in the internal Dual Ported RAM (in case CPUs 5991which provide such a feature like MPC8xx or MPC8260), or in a locked 5992part of the data cache. After that, U-Boot initializes the CPU core, 5993the caches and the SIU. 5994 5995Next, all (potentially) available memory banks are mapped using a 5996preliminary mapping. For example, we put them on 512 MB boundaries 5997(multiples of 0x20000000: SDRAM on 0x00000000 and 0x20000000, Flash 5998on 0x40000000 and 0x60000000, SRAM on 0x80000000). Then UPM A is 5999programmed for SDRAM access. Using the temporary configuration, a 6000simple memory test is run that determines the size of the SDRAM 6001banks. 6002 6003When there is more than one SDRAM bank, and the banks are of 6004different size, the largest is mapped first. For equal size, the first 6005bank (CS2#) is mapped first. The first mapping is always for address 60060x00000000, with any additional banks following immediately to create 6007contiguous memory starting from 0. 6008 6009Then, the monitor installs itself at the upper end of the SDRAM area 6010and allocates memory for use by malloc() and for the global Board 6011Info data; also, the exception vector code is copied to the low RAM 6012pages, and the final stack is set up. 6013 6014Only after this relocation will you have a "normal" C environment; 6015until that you are restricted in several ways, mostly because you are 6016running from ROM, and because the code will have to be relocated to a 6017new address in RAM. 6018 6019 6020U-Boot Porting Guide: 6021---------------------- 6022 6023[Based on messages by Jerry Van Baren in the U-Boot-Users mailing 6024list, October 2002] 6025 6026 6027int main(int argc, char *argv[]) 6028{ 6029 sighandler_t no_more_time; 6030 6031 signal(SIGALRM, no_more_time); 6032 alarm(PROJECT_DEADLINE - toSec (3 * WEEK)); 6033 6034 if (available_money > available_manpower) { 6035 Pay consultant to port U-Boot; 6036 return 0; 6037 } 6038 6039 Download latest U-Boot source; 6040 6041 Subscribe to u-boot mailing list; 6042 6043 if (clueless) 6044 email("Hi, I am new to U-Boot, how do I get started?"); 6045 6046 while (learning) { 6047 Read the README file in the top level directory; 6048 Read http://www.denx.de/twiki/bin/view/DULG/Manual; 6049 Read applicable doc/*.README; 6050 Read the source, Luke; 6051 /* find . -name "*.[chS]" | xargs grep -i <keyword> */ 6052 } 6053 6054 if (available_money > toLocalCurrency ($2500)) 6055 Buy a BDI3000; 6056 else 6057 Add a lot of aggravation and time; 6058 6059 if (a similar board exists) { /* hopefully... */ 6060 cp -a board/<similar> board/<myboard> 6061 cp include/configs/<similar>.h include/configs/<myboard>.h 6062 } else { 6063 Create your own board support subdirectory; 6064 Create your own board include/configs/<myboard>.h file; 6065 } 6066 Edit new board/<myboard> files 6067 Edit new include/configs/<myboard>.h 6068 6069 while (!accepted) { 6070 while (!running) { 6071 do { 6072 Add / modify source code; 6073 } until (compiles); 6074 Debug; 6075 if (clueless) 6076 email("Hi, I am having problems..."); 6077 } 6078 Send patch file to the U-Boot email list; 6079 if (reasonable critiques) 6080 Incorporate improvements from email list code review; 6081 else 6082 Defend code as written; 6083 } 6084 6085 return 0; 6086} 6087 6088void no_more_time (int sig) 6089{ 6090 hire_a_guru(); 6091} 6092 6093 6094Coding Standards: 6095----------------- 6096 6097All contributions to U-Boot should conform to the Linux kernel 6098coding style; see the file "Documentation/CodingStyle" and the script 6099"scripts/Lindent" in your Linux kernel source directory. 6100 6101Source files originating from a different project (for example the 6102MTD subsystem) are generally exempt from these guidelines and are not 6103reformatted to ease subsequent migration to newer versions of those 6104sources. 6105 6106Please note that U-Boot is implemented in C (and to some small parts in 6107Assembler); no C++ is used, so please do not use C++ style comments (//) 6108in your code. 6109 6110Please also stick to the following formatting rules: 6111- remove any trailing white space 6112- use TAB characters for indentation and vertical alignment, not spaces 6113- make sure NOT to use DOS '\r\n' line feeds 6114- do not add more than 2 consecutive empty lines to source files 6115- do not add trailing empty lines to source files 6116 6117Submissions which do not conform to the standards may be returned 6118with a request to reformat the changes. 6119 6120 6121Submitting Patches: 6122------------------- 6123 6124Since the number of patches for U-Boot is growing, we need to 6125establish some rules. Submissions which do not conform to these rules 6126may be rejected, even when they contain important and valuable stuff. 6127 6128Please see http://www.denx.de/wiki/U-Boot/Patches for details. 6129 6130Patches shall be sent to the u-boot mailing list <u-boot@lists.denx.de>; 6131see http://lists.denx.de/mailman/listinfo/u-boot 6132 6133When you send a patch, please include the following information with 6134it: 6135 6136* For bug fixes: a description of the bug and how your patch fixes 6137 this bug. Please try to include a way of demonstrating that the 6138 patch actually fixes something. 6139 6140* For new features: a description of the feature and your 6141 implementation. 6142 6143* A CHANGELOG entry as plaintext (separate from the patch) 6144 6145* For major contributions, add a MAINTAINERS file with your 6146 information and associated file and directory references. 6147 6148* When you add support for a new board, don't forget to add a 6149 maintainer e-mail address to the boards.cfg file, too. 6150 6151* If your patch adds new configuration options, don't forget to 6152 document these in the README file. 6153 6154* The patch itself. If you are using git (which is *strongly* 6155 recommended) you can easily generate the patch using the 6156 "git format-patch". If you then use "git send-email" to send it to 6157 the U-Boot mailing list, you will avoid most of the common problems 6158 with some other mail clients. 6159 6160 If you cannot use git, use "diff -purN OLD NEW". If your version of 6161 diff does not support these options, then get the latest version of 6162 GNU diff. 6163 6164 The current directory when running this command shall be the parent 6165 directory of the U-Boot source tree (i. e. please make sure that 6166 your patch includes sufficient directory information for the 6167 affected files). 6168 6169 We prefer patches as plain text. MIME attachments are discouraged, 6170 and compressed attachments must not be used. 6171 6172* If one logical set of modifications affects or creates several 6173 files, all these changes shall be submitted in a SINGLE patch file. 6174 6175* Changesets that contain different, unrelated modifications shall be 6176 submitted as SEPARATE patches, one patch per changeset. 6177 6178 6179Notes: 6180 6181* Before sending the patch, run the buildman script on your patched 6182 source tree and make sure that no errors or warnings are reported 6183 for any of the boards. 6184 6185* Keep your modifications to the necessary minimum: A patch 6186 containing several unrelated changes or arbitrary reformats will be 6187 returned with a request to re-formatting / split it. 6188 6189* If you modify existing code, make sure that your new code does not 6190 add to the memory footprint of the code ;-) Small is beautiful! 6191 When adding new features, these should compile conditionally only 6192 (using #ifdef), and the resulting code with the new feature 6193 disabled must not need more memory than the old code without your 6194 modification. 6195 6196* Remember that there is a size limit of 100 kB per message on the 6197 u-boot mailing list. Bigger patches will be moderated. If they are 6198 reasonable and not too big, they will be acknowledged. But patches 6199 bigger than the size limit should be avoided. 6200