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- FAT(File Allocation Table) filesystem cluster size: 1550 CONFIG_FS_FAT_MAX_CLUSTSIZE 1551 1552 Define the max cluster size for fat operations else 1553 a default value of 65536 will be defined. 1554 1555- Keyboard Support: 1556 See Kconfig help for available keyboard drivers. 1557 1558 CONFIG_KEYBOARD 1559 1560 Define this to enable a custom keyboard support. 1561 This simply calls drv_keyboard_init() which must be 1562 defined in your board-specific files. This option is deprecated 1563 and is only used by novena. For new boards, use driver model 1564 instead. 1565 1566- Video support: 1567 CONFIG_FSL_DIU_FB 1568 Enable the Freescale DIU video driver. Reference boards for 1569 SOCs that have a DIU should define this macro to enable DIU 1570 support, and should also define these other macros: 1571 1572 CONFIG_SYS_DIU_ADDR 1573 CONFIG_VIDEO 1574 CONFIG_CFB_CONSOLE 1575 CONFIG_VIDEO_SW_CURSOR 1576 CONFIG_VGA_AS_SINGLE_DEVICE 1577 CONFIG_VIDEO_LOGO 1578 CONFIG_VIDEO_BMP_LOGO 1579 1580 The DIU driver will look for the 'video-mode' environment 1581 variable, and if defined, enable the DIU as a console during 1582 boot. See the documentation file doc/README.video for a 1583 description of this variable. 1584 1585- LCD Support: CONFIG_LCD 1586 1587 Define this to enable LCD support (for output to LCD 1588 display); also select one of the supported displays 1589 by defining one of these: 1590 1591 CONFIG_ATMEL_LCD: 1592 1593 HITACHI TX09D70VM1CCA, 3.5", 240x320. 1594 1595 CONFIG_NEC_NL6448AC33: 1596 1597 NEC NL6448AC33-18. Active, color, single scan. 1598 1599 CONFIG_NEC_NL6448BC20 1600 1601 NEC NL6448BC20-08. 6.5", 640x480. 1602 Active, color, single scan. 1603 1604 CONFIG_NEC_NL6448BC33_54 1605 1606 NEC NL6448BC33-54. 10.4", 640x480. 1607 Active, color, single scan. 1608 1609 CONFIG_SHARP_16x9 1610 1611 Sharp 320x240. Active, color, single scan. 1612 It isn't 16x9, and I am not sure what it is. 1613 1614 CONFIG_SHARP_LQ64D341 1615 1616 Sharp LQ64D341 display, 640x480. 1617 Active, color, single scan. 1618 1619 CONFIG_HLD1045 1620 1621 HLD1045 display, 640x480. 1622 Active, color, single scan. 1623 1624 CONFIG_OPTREX_BW 1625 1626 Optrex CBL50840-2 NF-FW 99 22 M5 1627 or 1628 Hitachi LMG6912RPFC-00T 1629 or 1630 Hitachi SP14Q002 1631 1632 320x240. Black & white. 1633 1634 CONFIG_LCD_ALIGNMENT 1635 1636 Normally the LCD is page-aligned (typically 4KB). If this is 1637 defined then the LCD will be aligned to this value instead. 1638 For ARM it is sometimes useful to use MMU_SECTION_SIZE 1639 here, since it is cheaper to change data cache settings on 1640 a per-section basis. 1641 1642 1643 CONFIG_LCD_ROTATION 1644 1645 Sometimes, for example if the display is mounted in portrait 1646 mode or even if it's mounted landscape but rotated by 180degree, 1647 we need to rotate our content of the display relative to the 1648 framebuffer, so that user can read the messages which are 1649 printed out. 1650 Once CONFIG_LCD_ROTATION is defined, the lcd_console will be 1651 initialized with a given rotation from "vl_rot" out of 1652 "vidinfo_t" which is provided by the board specific code. 1653 The value for vl_rot is coded as following (matching to 1654 fbcon=rotate:<n> linux-kernel commandline): 1655 0 = no rotation respectively 0 degree 1656 1 = 90 degree rotation 1657 2 = 180 degree rotation 1658 3 = 270 degree rotation 1659 1660 If CONFIG_LCD_ROTATION is not defined, the console will be 1661 initialized with 0degree rotation. 1662 1663 CONFIG_LCD_BMP_RLE8 1664 1665 Support drawing of RLE8-compressed bitmaps on the LCD. 1666 1667 CONFIG_I2C_EDID 1668 1669 Enables an 'i2c edid' command which can read EDID 1670 information over I2C from an attached LCD display. 1671 1672- Splash Screen Support: CONFIG_SPLASH_SCREEN 1673 1674 If this option is set, the environment is checked for 1675 a variable "splashimage". If found, the usual display 1676 of logo, copyright and system information on the LCD 1677 is suppressed and the BMP image at the address 1678 specified in "splashimage" is loaded instead. The 1679 console is redirected to the "nulldev", too. This 1680 allows for a "silent" boot where a splash screen is 1681 loaded very quickly after power-on. 1682 1683 CONFIG_SPLASHIMAGE_GUARD 1684 1685 If this option is set, then U-Boot will prevent the environment 1686 variable "splashimage" from being set to a problematic address 1687 (see doc/README.displaying-bmps). 1688 This option is useful for targets where, due to alignment 1689 restrictions, an improperly aligned BMP image will cause a data 1690 abort. If you think you will not have problems with unaligned 1691 accesses (for example because your toolchain prevents them) 1692 there is no need to set this option. 1693 1694 CONFIG_SPLASH_SCREEN_ALIGN 1695 1696 If this option is set the splash image can be freely positioned 1697 on the screen. Environment variable "splashpos" specifies the 1698 position as "x,y". If a positive number is given it is used as 1699 number of pixel from left/top. If a negative number is given it 1700 is used as number of pixel from right/bottom. You can also 1701 specify 'm' for centering the image. 1702 1703 Example: 1704 setenv splashpos m,m 1705 => image at center of screen 1706 1707 setenv splashpos 30,20 1708 => image at x = 30 and y = 20 1709 1710 setenv splashpos -10,m 1711 => vertically centered image 1712 at x = dspWidth - bmpWidth - 9 1713 1714- Gzip compressed BMP image support: CONFIG_VIDEO_BMP_GZIP 1715 1716 If this option is set, additionally to standard BMP 1717 images, gzipped BMP images can be displayed via the 1718 splashscreen support or the bmp command. 1719 1720- Run length encoded BMP image (RLE8) support: CONFIG_VIDEO_BMP_RLE8 1721 1722 If this option is set, 8-bit RLE compressed BMP images 1723 can be displayed via the splashscreen support or the 1724 bmp command. 1725 1726- Compression support: 1727 CONFIG_GZIP 1728 1729 Enabled by default to support gzip compressed images. 1730 1731 CONFIG_BZIP2 1732 1733 If this option is set, support for bzip2 compressed 1734 images is included. If not, only uncompressed and gzip 1735 compressed images are supported. 1736 1737 NOTE: the bzip2 algorithm requires a lot of RAM, so 1738 the malloc area (as defined by CONFIG_SYS_MALLOC_LEN) should 1739 be at least 4MB. 1740 1741 CONFIG_LZMA 1742 1743 If this option is set, support for lzma compressed 1744 images is included. 1745 1746 Note: The LZMA algorithm adds between 2 and 4KB of code and it 1747 requires an amount of dynamic memory that is given by the 1748 formula: 1749 1750 (1846 + 768 << (lc + lp)) * sizeof(uint16) 1751 1752 Where lc and lp stand for, respectively, Literal context bits 1753 and Literal pos bits. 1754 1755 This value is upper-bounded by 14MB in the worst case. Anyway, 1756 for a ~4MB large kernel image, we have lc=3 and lp=0 for a 1757 total amount of (1846 + 768 << (3 + 0)) * 2 = ~41KB... that is 1758 a very small buffer. 1759 1760 Use the lzmainfo tool to determinate the lc and lp values and 1761 then calculate the amount of needed dynamic memory (ensuring 1762 the appropriate CONFIG_SYS_MALLOC_LEN value). 1763 1764 CONFIG_LZO 1765 1766 If this option is set, support for LZO compressed images 1767 is included. 1768 1769- MII/PHY support: 1770 CONFIG_PHY_ADDR 1771 1772 The address of PHY on MII bus. 1773 1774 CONFIG_PHY_CLOCK_FREQ (ppc4xx) 1775 1776 The clock frequency of the MII bus 1777 1778 CONFIG_PHY_GIGE 1779 1780 If this option is set, support for speed/duplex 1781 detection of gigabit PHY is included. 1782 1783 CONFIG_PHY_RESET_DELAY 1784 1785 Some PHY like Intel LXT971A need extra delay after 1786 reset before any MII register access is possible. 1787 For such PHY, set this option to the usec delay 1788 required. (minimum 300usec for LXT971A) 1789 1790 CONFIG_PHY_CMD_DELAY (ppc4xx) 1791 1792 Some PHY like Intel LXT971A need extra delay after 1793 command issued before MII status register can be read 1794 1795- IP address: 1796 CONFIG_IPADDR 1797 1798 Define a default value for the IP address to use for 1799 the default Ethernet interface, in case this is not 1800 determined through e.g. bootp. 1801 (Environment variable "ipaddr") 1802 1803- Server IP address: 1804 CONFIG_SERVERIP 1805 1806 Defines a default value for the IP address of a TFTP 1807 server to contact when using the "tftboot" command. 1808 (Environment variable "serverip") 1809 1810 CONFIG_KEEP_SERVERADDR 1811 1812 Keeps the server's MAC address, in the env 'serveraddr' 1813 for passing to bootargs (like Linux's netconsole option) 1814 1815- Gateway IP address: 1816 CONFIG_GATEWAYIP 1817 1818 Defines a default value for the IP address of the 1819 default router where packets to other networks are 1820 sent to. 1821 (Environment variable "gatewayip") 1822 1823- Subnet mask: 1824 CONFIG_NETMASK 1825 1826 Defines a default value for the subnet mask (or 1827 routing prefix) which is used to determine if an IP 1828 address belongs to the local subnet or needs to be 1829 forwarded through a router. 1830 (Environment variable "netmask") 1831 1832- Multicast TFTP Mode: 1833 CONFIG_MCAST_TFTP 1834 1835 Defines whether you want to support multicast TFTP as per 1836 rfc-2090; for example to work with atftp. Lets lots of targets 1837 tftp down the same boot image concurrently. Note: the Ethernet 1838 driver in use must provide a function: mcast() to join/leave a 1839 multicast group. 1840 1841- BOOTP Recovery Mode: 1842 CONFIG_BOOTP_RANDOM_DELAY 1843 1844 If you have many targets in a network that try to 1845 boot using BOOTP, you may want to avoid that all 1846 systems send out BOOTP requests at precisely the same 1847 moment (which would happen for instance at recovery 1848 from a power failure, when all systems will try to 1849 boot, thus flooding the BOOTP server. Defining 1850 CONFIG_BOOTP_RANDOM_DELAY causes a random delay to be 1851 inserted before sending out BOOTP requests. The 1852 following delays are inserted then: 1853 1854 1st BOOTP request: delay 0 ... 1 sec 1855 2nd BOOTP request: delay 0 ... 2 sec 1856 3rd BOOTP request: delay 0 ... 4 sec 1857 4th and following 1858 BOOTP requests: delay 0 ... 8 sec 1859 1860 CONFIG_BOOTP_ID_CACHE_SIZE 1861 1862 BOOTP packets are uniquely identified using a 32-bit ID. The 1863 server will copy the ID from client requests to responses and 1864 U-Boot will use this to determine if it is the destination of 1865 an incoming response. Some servers will check that addresses 1866 aren't in use before handing them out (usually using an ARP 1867 ping) and therefore take up to a few hundred milliseconds to 1868 respond. Network congestion may also influence the time it 1869 takes for a response to make it back to the client. If that 1870 time is too long, U-Boot will retransmit requests. In order 1871 to allow earlier responses to still be accepted after these 1872 retransmissions, U-Boot's BOOTP client keeps a small cache of 1873 IDs. The CONFIG_BOOTP_ID_CACHE_SIZE controls the size of this 1874 cache. The default is to keep IDs for up to four outstanding 1875 requests. Increasing this will allow U-Boot to accept offers 1876 from a BOOTP client in networks with unusually high latency. 1877 1878- DHCP Advanced Options: 1879 You can fine tune the DHCP functionality by defining 1880 CONFIG_BOOTP_* symbols: 1881 1882 CONFIG_BOOTP_SUBNETMASK 1883 CONFIG_BOOTP_GATEWAY 1884 CONFIG_BOOTP_HOSTNAME 1885 CONFIG_BOOTP_NISDOMAIN 1886 CONFIG_BOOTP_BOOTPATH 1887 CONFIG_BOOTP_BOOTFILESIZE 1888 CONFIG_BOOTP_DNS 1889 CONFIG_BOOTP_DNS2 1890 CONFIG_BOOTP_SEND_HOSTNAME 1891 CONFIG_BOOTP_NTPSERVER 1892 CONFIG_BOOTP_TIMEOFFSET 1893 CONFIG_BOOTP_VENDOREX 1894 CONFIG_BOOTP_MAY_FAIL 1895 1896 CONFIG_BOOTP_SERVERIP - TFTP server will be the serverip 1897 environment variable, not the BOOTP server. 1898 1899 CONFIG_BOOTP_MAY_FAIL - If the DHCP server is not found 1900 after the configured retry count, the call will fail 1901 instead of starting over. This can be used to fail over 1902 to Link-local IP address configuration if the DHCP server 1903 is not available. 1904 1905 CONFIG_BOOTP_DNS2 - If a DHCP client requests the DNS 1906 serverip from a DHCP server, it is possible that more 1907 than one DNS serverip is offered to the client. 1908 If CONFIG_BOOTP_DNS2 is enabled, the secondary DNS 1909 serverip will be stored in the additional environment 1910 variable "dnsip2". The first DNS serverip is always 1911 stored in the variable "dnsip", when CONFIG_BOOTP_DNS 1912 is defined. 1913 1914 CONFIG_BOOTP_SEND_HOSTNAME - Some DHCP servers are capable 1915 to do a dynamic update of a DNS server. To do this, they 1916 need the hostname of the DHCP requester. 1917 If CONFIG_BOOTP_SEND_HOSTNAME is defined, the content 1918 of the "hostname" environment variable is passed as 1919 option 12 to the DHCP server. 1920 1921 CONFIG_BOOTP_DHCP_REQUEST_DELAY 1922 1923 A 32bit value in microseconds for a delay between 1924 receiving a "DHCP Offer" and sending the "DHCP Request". 1925 This fixes a problem with certain DHCP servers that don't 1926 respond 100% of the time to a "DHCP request". E.g. On an 1927 AT91RM9200 processor running at 180MHz, this delay needed 1928 to be *at least* 15,000 usec before a Windows Server 2003 1929 DHCP server would reply 100% of the time. I recommend at 1930 least 50,000 usec to be safe. The alternative is to hope 1931 that one of the retries will be successful but note that 1932 the DHCP timeout and retry process takes a longer than 1933 this delay. 1934 1935 - Link-local IP address negotiation: 1936 Negotiate with other link-local clients on the local network 1937 for an address that doesn't require explicit configuration. 1938 This is especially useful if a DHCP server cannot be guaranteed 1939 to exist in all environments that the device must operate. 1940 1941 See doc/README.link-local for more information. 1942 1943 - CDP Options: 1944 CONFIG_CDP_DEVICE_ID 1945 1946 The device id used in CDP trigger frames. 1947 1948 CONFIG_CDP_DEVICE_ID_PREFIX 1949 1950 A two character string which is prefixed to the MAC address 1951 of the device. 1952 1953 CONFIG_CDP_PORT_ID 1954 1955 A printf format string which contains the ascii name of 1956 the port. Normally is set to "eth%d" which sets 1957 eth0 for the first Ethernet, eth1 for the second etc. 1958 1959 CONFIG_CDP_CAPABILITIES 1960 1961 A 32bit integer which indicates the device capabilities; 1962 0x00000010 for a normal host which does not forwards. 1963 1964 CONFIG_CDP_VERSION 1965 1966 An ascii string containing the version of the software. 1967 1968 CONFIG_CDP_PLATFORM 1969 1970 An ascii string containing the name of the platform. 1971 1972 CONFIG_CDP_TRIGGER 1973 1974 A 32bit integer sent on the trigger. 1975 1976 CONFIG_CDP_POWER_CONSUMPTION 1977 1978 A 16bit integer containing the power consumption of the 1979 device in .1 of milliwatts. 1980 1981 CONFIG_CDP_APPLIANCE_VLAN_TYPE 1982 1983 A byte containing the id of the VLAN. 1984 1985- Status LED: CONFIG_LED_STATUS 1986 1987 Several configurations allow to display the current 1988 status using a LED. For instance, the LED will blink 1989 fast while running U-Boot code, stop blinking as 1990 soon as a reply to a BOOTP request was received, and 1991 start blinking slow once the Linux kernel is running 1992 (supported by a status LED driver in the Linux 1993 kernel). Defining CONFIG_LED_STATUS enables this 1994 feature in U-Boot. 1995 1996 Additional options: 1997 1998 CONFIG_LED_STATUS_GPIO 1999 The status LED can be connected to a GPIO pin. 2000 In such cases, the gpio_led driver can be used as a 2001 status LED backend implementation. Define CONFIG_LED_STATUS_GPIO 2002 to include the gpio_led driver in the U-Boot binary. 2003 2004 CONFIG_GPIO_LED_INVERTED_TABLE 2005 Some GPIO connected LEDs may have inverted polarity in which 2006 case the GPIO high value corresponds to LED off state and 2007 GPIO low value corresponds to LED on state. 2008 In such cases CONFIG_GPIO_LED_INVERTED_TABLE may be defined 2009 with a list of GPIO LEDs that have inverted polarity. 2010 2011- CAN Support: CONFIG_CAN_DRIVER 2012 2013 Defining CONFIG_CAN_DRIVER enables CAN driver support 2014 on those systems that support this (optional) 2015 feature, like the TQM8xxL modules. 2016 2017- I2C Support: CONFIG_SYS_I2C 2018 2019 This enable the NEW i2c subsystem, and will allow you to use 2020 i2c commands at the u-boot command line (as long as you set 2021 CONFIG_CMD_I2C in CONFIG_COMMANDS) and communicate with i2c 2022 based realtime clock chips or other i2c devices. See 2023 common/cmd_i2c.c for a description of the command line 2024 interface. 2025 2026 ported i2c driver to the new framework: 2027 - drivers/i2c/soft_i2c.c: 2028 - activate first bus with CONFIG_SYS_I2C_SOFT define 2029 CONFIG_SYS_I2C_SOFT_SPEED and CONFIG_SYS_I2C_SOFT_SLAVE 2030 for defining speed and slave address 2031 - activate second bus with I2C_SOFT_DECLARATIONS2 define 2032 CONFIG_SYS_I2C_SOFT_SPEED_2 and CONFIG_SYS_I2C_SOFT_SLAVE_2 2033 for defining speed and slave address 2034 - activate third bus with I2C_SOFT_DECLARATIONS3 define 2035 CONFIG_SYS_I2C_SOFT_SPEED_3 and CONFIG_SYS_I2C_SOFT_SLAVE_3 2036 for defining speed and slave address 2037 - activate fourth bus with I2C_SOFT_DECLARATIONS4 define 2038 CONFIG_SYS_I2C_SOFT_SPEED_4 and CONFIG_SYS_I2C_SOFT_SLAVE_4 2039 for defining speed and slave address 2040 2041 - drivers/i2c/fsl_i2c.c: 2042 - activate i2c driver with CONFIG_SYS_I2C_FSL 2043 define CONFIG_SYS_FSL_I2C_OFFSET for setting the register 2044 offset CONFIG_SYS_FSL_I2C_SPEED for the i2c speed and 2045 CONFIG_SYS_FSL_I2C_SLAVE for the slave addr of the first 2046 bus. 2047 - If your board supports a second fsl i2c bus, define 2048 CONFIG_SYS_FSL_I2C2_OFFSET for the register offset 2049 CONFIG_SYS_FSL_I2C2_SPEED for the speed and 2050 CONFIG_SYS_FSL_I2C2_SLAVE for the slave address of the 2051 second bus. 2052 2053 - drivers/i2c/tegra_i2c.c: 2054 - activate this driver with CONFIG_SYS_I2C_TEGRA 2055 - This driver adds 4 i2c buses with a fix speed from 2056 100000 and the slave addr 0! 2057 2058 - drivers/i2c/ppc4xx_i2c.c 2059 - activate this driver with CONFIG_SYS_I2C_PPC4XX 2060 - CONFIG_SYS_I2C_PPC4XX_CH0 activate hardware channel 0 2061 - CONFIG_SYS_I2C_PPC4XX_CH1 activate hardware channel 1 2062 2063 - drivers/i2c/i2c_mxc.c 2064 - activate this driver with CONFIG_SYS_I2C_MXC 2065 - enable bus 1 with CONFIG_SYS_I2C_MXC_I2C1 2066 - enable bus 2 with CONFIG_SYS_I2C_MXC_I2C2 2067 - enable bus 3 with CONFIG_SYS_I2C_MXC_I2C3 2068 - enable bus 4 with CONFIG_SYS_I2C_MXC_I2C4 2069 - define speed for bus 1 with CONFIG_SYS_MXC_I2C1_SPEED 2070 - define slave for bus 1 with CONFIG_SYS_MXC_I2C1_SLAVE 2071 - define speed for bus 2 with CONFIG_SYS_MXC_I2C2_SPEED 2072 - define slave for bus 2 with CONFIG_SYS_MXC_I2C2_SLAVE 2073 - define speed for bus 3 with CONFIG_SYS_MXC_I2C3_SPEED 2074 - define slave for bus 3 with CONFIG_SYS_MXC_I2C3_SLAVE 2075 - define speed for bus 4 with CONFIG_SYS_MXC_I2C4_SPEED 2076 - define slave for bus 4 with CONFIG_SYS_MXC_I2C4_SLAVE 2077 If those defines are not set, default value is 100000 2078 for speed, and 0 for slave. 2079 2080 - drivers/i2c/rcar_i2c.c: 2081 - activate this driver with CONFIG_SYS_I2C_RCAR 2082 - This driver adds 4 i2c buses 2083 2084 - CONFIG_SYS_RCAR_I2C0_BASE for setting the register channel 0 2085 - CONFIG_SYS_RCAR_I2C0_SPEED for for the speed channel 0 2086 - CONFIG_SYS_RCAR_I2C1_BASE for setting the register channel 1 2087 - CONFIG_SYS_RCAR_I2C1_SPEED for for the speed channel 1 2088 - CONFIG_SYS_RCAR_I2C2_BASE for setting the register channel 2 2089 - CONFIG_SYS_RCAR_I2C2_SPEED for for the speed channel 2 2090 - CONFIG_SYS_RCAR_I2C3_BASE for setting the register channel 3 2091 - CONFIG_SYS_RCAR_I2C3_SPEED for for the speed channel 3 2092 - CONFIF_SYS_RCAR_I2C_NUM_CONTROLLERS for number of i2c buses 2093 2094 - drivers/i2c/sh_i2c.c: 2095 - activate this driver with CONFIG_SYS_I2C_SH 2096 - This driver adds from 2 to 5 i2c buses 2097 2098 - CONFIG_SYS_I2C_SH_BASE0 for setting the register channel 0 2099 - CONFIG_SYS_I2C_SH_SPEED0 for for the speed channel 0 2100 - CONFIG_SYS_I2C_SH_BASE1 for setting the register channel 1 2101 - CONFIG_SYS_I2C_SH_SPEED1 for for the speed channel 1 2102 - CONFIG_SYS_I2C_SH_BASE2 for setting the register channel 2 2103 - CONFIG_SYS_I2C_SH_SPEED2 for for the speed channel 2 2104 - CONFIG_SYS_I2C_SH_BASE3 for setting the register channel 3 2105 - CONFIG_SYS_I2C_SH_SPEED3 for for the speed channel 3 2106 - CONFIG_SYS_I2C_SH_BASE4 for setting the register channel 4 2107 - CONFIG_SYS_I2C_SH_SPEED4 for for the speed channel 4 2108 - CONFIG_SYS_I2C_SH_NUM_CONTROLLERS for number of i2c buses 2109 2110 - drivers/i2c/omap24xx_i2c.c 2111 - activate this driver with CONFIG_SYS_I2C_OMAP24XX 2112 - CONFIG_SYS_OMAP24_I2C_SPEED speed channel 0 2113 - CONFIG_SYS_OMAP24_I2C_SLAVE slave addr channel 0 2114 - CONFIG_SYS_OMAP24_I2C_SPEED1 speed channel 1 2115 - CONFIG_SYS_OMAP24_I2C_SLAVE1 slave addr channel 1 2116 - CONFIG_SYS_OMAP24_I2C_SPEED2 speed channel 2 2117 - CONFIG_SYS_OMAP24_I2C_SLAVE2 slave addr channel 2 2118 - CONFIG_SYS_OMAP24_I2C_SPEED3 speed channel 3 2119 - CONFIG_SYS_OMAP24_I2C_SLAVE3 slave addr channel 3 2120 - CONFIG_SYS_OMAP24_I2C_SPEED4 speed channel 4 2121 - CONFIG_SYS_OMAP24_I2C_SLAVE4 slave addr channel 4 2122 2123 - drivers/i2c/zynq_i2c.c 2124 - activate this driver with CONFIG_SYS_I2C_ZYNQ 2125 - set CONFIG_SYS_I2C_ZYNQ_SPEED for speed setting 2126 - set CONFIG_SYS_I2C_ZYNQ_SLAVE for slave addr 2127 2128 - drivers/i2c/s3c24x0_i2c.c: 2129 - activate this driver with CONFIG_SYS_I2C_S3C24X0 2130 - This driver adds i2c buses (11 for Exynos5250, Exynos5420 2131 9 i2c buses for Exynos4 and 1 for S3C24X0 SoCs from Samsung) 2132 with a fix speed from 100000 and the slave addr 0! 2133 2134 - drivers/i2c/ihs_i2c.c 2135 - activate this driver with CONFIG_SYS_I2C_IHS 2136 - CONFIG_SYS_I2C_IHS_CH0 activate hardware channel 0 2137 - CONFIG_SYS_I2C_IHS_SPEED_0 speed channel 0 2138 - CONFIG_SYS_I2C_IHS_SLAVE_0 slave addr channel 0 2139 - CONFIG_SYS_I2C_IHS_CH1 activate hardware channel 1 2140 - CONFIG_SYS_I2C_IHS_SPEED_1 speed channel 1 2141 - CONFIG_SYS_I2C_IHS_SLAVE_1 slave addr channel 1 2142 - CONFIG_SYS_I2C_IHS_CH2 activate hardware channel 2 2143 - CONFIG_SYS_I2C_IHS_SPEED_2 speed channel 2 2144 - CONFIG_SYS_I2C_IHS_SLAVE_2 slave addr channel 2 2145 - CONFIG_SYS_I2C_IHS_CH3 activate hardware channel 3 2146 - CONFIG_SYS_I2C_IHS_SPEED_3 speed channel 3 2147 - CONFIG_SYS_I2C_IHS_SLAVE_3 slave addr channel 3 2148 - activate dual channel with CONFIG_SYS_I2C_IHS_DUAL 2149 - CONFIG_SYS_I2C_IHS_SPEED_0_1 speed channel 0_1 2150 - CONFIG_SYS_I2C_IHS_SLAVE_0_1 slave addr channel 0_1 2151 - CONFIG_SYS_I2C_IHS_SPEED_1_1 speed channel 1_1 2152 - CONFIG_SYS_I2C_IHS_SLAVE_1_1 slave addr channel 1_1 2153 - CONFIG_SYS_I2C_IHS_SPEED_2_1 speed channel 2_1 2154 - CONFIG_SYS_I2C_IHS_SLAVE_2_1 slave addr channel 2_1 2155 - CONFIG_SYS_I2C_IHS_SPEED_3_1 speed channel 3_1 2156 - CONFIG_SYS_I2C_IHS_SLAVE_3_1 slave addr channel 3_1 2157 2158 additional defines: 2159 2160 CONFIG_SYS_NUM_I2C_BUSES 2161 Hold the number of i2c buses you want to use. 2162 2163 CONFIG_SYS_I2C_DIRECT_BUS 2164 define this, if you don't use i2c muxes on your hardware. 2165 if CONFIG_SYS_I2C_MAX_HOPS is not defined or == 0 you can 2166 omit this define. 2167 2168 CONFIG_SYS_I2C_MAX_HOPS 2169 define how many muxes are maximal consecutively connected 2170 on one i2c bus. If you not use i2c muxes, omit this 2171 define. 2172 2173 CONFIG_SYS_I2C_BUSES 2174 hold a list of buses you want to use, only used if 2175 CONFIG_SYS_I2C_DIRECT_BUS is not defined, for example 2176 a board with CONFIG_SYS_I2C_MAX_HOPS = 1 and 2177 CONFIG_SYS_NUM_I2C_BUSES = 9: 2178 2179 CONFIG_SYS_I2C_BUSES {{0, {I2C_NULL_HOP}}, \ 2180 {0, {{I2C_MUX_PCA9547, 0x70, 1}}}, \ 2181 {0, {{I2C_MUX_PCA9547, 0x70, 2}}}, \ 2182 {0, {{I2C_MUX_PCA9547, 0x70, 3}}}, \ 2183 {0, {{I2C_MUX_PCA9547, 0x70, 4}}}, \ 2184 {0, {{I2C_MUX_PCA9547, 0x70, 5}}}, \ 2185 {1, {I2C_NULL_HOP}}, \ 2186 {1, {{I2C_MUX_PCA9544, 0x72, 1}}}, \ 2187 {1, {{I2C_MUX_PCA9544, 0x72, 2}}}, \ 2188 } 2189 2190 which defines 2191 bus 0 on adapter 0 without a mux 2192 bus 1 on adapter 0 with a PCA9547 on address 0x70 port 1 2193 bus 2 on adapter 0 with a PCA9547 on address 0x70 port 2 2194 bus 3 on adapter 0 with a PCA9547 on address 0x70 port 3 2195 bus 4 on adapter 0 with a PCA9547 on address 0x70 port 4 2196 bus 5 on adapter 0 with a PCA9547 on address 0x70 port 5 2197 bus 6 on adapter 1 without a mux 2198 bus 7 on adapter 1 with a PCA9544 on address 0x72 port 1 2199 bus 8 on adapter 1 with a PCA9544 on address 0x72 port 2 2200 2201 If you do not have i2c muxes on your board, omit this define. 2202 2203- Legacy I2C Support: CONFIG_HARD_I2C 2204 2205 NOTE: It is intended to move drivers to CONFIG_SYS_I2C which 2206 provides the following compelling advantages: 2207 2208 - more than one i2c adapter is usable 2209 - approved multibus support 2210 - better i2c mux support 2211 2212 ** Please consider updating your I2C driver now. ** 2213 2214 These enable legacy I2C serial bus commands. Defining 2215 CONFIG_HARD_I2C will include the appropriate I2C driver 2216 for the selected CPU. 2217 2218 This will allow you to use i2c commands at the u-boot 2219 command line (as long as you set CONFIG_CMD_I2C in 2220 CONFIG_COMMANDS) and communicate with i2c based realtime 2221 clock chips. See common/cmd_i2c.c for a description of the 2222 command line interface. 2223 2224 CONFIG_HARD_I2C selects a hardware I2C controller. 2225 2226 There are several other quantities that must also be 2227 defined when you define CONFIG_HARD_I2C. 2228 2229 In both cases you will need to define CONFIG_SYS_I2C_SPEED 2230 to be the frequency (in Hz) at which you wish your i2c bus 2231 to run and CONFIG_SYS_I2C_SLAVE to be the address of this node (ie 2232 the CPU's i2c node address). 2233 2234 Now, the u-boot i2c code for the mpc8xx 2235 (arch/powerpc/cpu/mpc8xx/i2c.c) sets the CPU up as a master node 2236 and so its address should therefore be cleared to 0 (See, 2237 eg, MPC823e User's Manual p.16-473). So, set 2238 CONFIG_SYS_I2C_SLAVE to 0. 2239 2240 CONFIG_SYS_I2C_INIT_MPC5XXX 2241 2242 When a board is reset during an i2c bus transfer 2243 chips might think that the current transfer is still 2244 in progress. Reset the slave devices by sending start 2245 commands until the slave device responds. 2246 2247 That's all that's required for CONFIG_HARD_I2C. 2248 2249 If you use the software i2c interface (CONFIG_SYS_I2C_SOFT) 2250 then the following macros need to be defined (examples are 2251 from include/configs/lwmon.h): 2252 2253 I2C_INIT 2254 2255 (Optional). Any commands necessary to enable the I2C 2256 controller or configure ports. 2257 2258 eg: #define I2C_INIT (immr->im_cpm.cp_pbdir |= PB_SCL) 2259 2260 I2C_PORT 2261 2262 (Only for MPC8260 CPU). The I/O port to use (the code 2263 assumes both bits are on the same port). Valid values 2264 are 0..3 for ports A..D. 2265 2266 I2C_ACTIVE 2267 2268 The code necessary to make the I2C data line active 2269 (driven). If the data line is open collector, this 2270 define can be null. 2271 2272 eg: #define I2C_ACTIVE (immr->im_cpm.cp_pbdir |= PB_SDA) 2273 2274 I2C_TRISTATE 2275 2276 The code necessary to make the I2C data line tri-stated 2277 (inactive). If the data line is open collector, this 2278 define can be null. 2279 2280 eg: #define I2C_TRISTATE (immr->im_cpm.cp_pbdir &= ~PB_SDA) 2281 2282 I2C_READ 2283 2284 Code that returns true if the I2C data line is high, 2285 false if it is low. 2286 2287 eg: #define I2C_READ ((immr->im_cpm.cp_pbdat & PB_SDA) != 0) 2288 2289 I2C_SDA(bit) 2290 2291 If <bit> is true, sets the I2C data line high. If it 2292 is false, it clears it (low). 2293 2294 eg: #define I2C_SDA(bit) \ 2295 if(bit) immr->im_cpm.cp_pbdat |= PB_SDA; \ 2296 else immr->im_cpm.cp_pbdat &= ~PB_SDA 2297 2298 I2C_SCL(bit) 2299 2300 If <bit> is true, sets the I2C clock line high. If it 2301 is false, it clears it (low). 2302 2303 eg: #define I2C_SCL(bit) \ 2304 if(bit) immr->im_cpm.cp_pbdat |= PB_SCL; \ 2305 else immr->im_cpm.cp_pbdat &= ~PB_SCL 2306 2307 I2C_DELAY 2308 2309 This delay is invoked four times per clock cycle so this 2310 controls the rate of data transfer. The data rate thus 2311 is 1 / (I2C_DELAY * 4). Often defined to be something 2312 like: 2313 2314 #define I2C_DELAY udelay(2) 2315 2316 CONFIG_SOFT_I2C_GPIO_SCL / CONFIG_SOFT_I2C_GPIO_SDA 2317 2318 If your arch supports the generic GPIO framework (asm/gpio.h), 2319 then you may alternatively define the two GPIOs that are to be 2320 used as SCL / SDA. Any of the previous I2C_xxx macros will 2321 have GPIO-based defaults assigned to them as appropriate. 2322 2323 You should define these to the GPIO value as given directly to 2324 the generic GPIO functions. 2325 2326 CONFIG_SYS_I2C_INIT_BOARD 2327 2328 When a board is reset during an i2c bus transfer 2329 chips might think that the current transfer is still 2330 in progress. On some boards it is possible to access 2331 the i2c SCLK line directly, either by using the 2332 processor pin as a GPIO or by having a second pin 2333 connected to the bus. If this option is defined a 2334 custom i2c_init_board() routine in boards/xxx/board.c 2335 is run early in the boot sequence. 2336 2337 CONFIG_SYS_I2C_BOARD_LATE_INIT 2338 2339 An alternative to CONFIG_SYS_I2C_INIT_BOARD. If this option is 2340 defined a custom i2c_board_late_init() routine in 2341 boards/xxx/board.c is run AFTER the operations in i2c_init() 2342 is completed. This callpoint can be used to unreset i2c bus 2343 using CPU i2c controller register accesses for CPUs whose i2c 2344 controller provide such a method. It is called at the end of 2345 i2c_init() to allow i2c_init operations to setup the i2c bus 2346 controller on the CPU (e.g. setting bus speed & slave address). 2347 2348 CONFIG_I2CFAST (PPC405GP|PPC405EP only) 2349 2350 This option enables configuration of bi_iic_fast[] flags 2351 in u-boot bd_info structure based on u-boot environment 2352 variable "i2cfast". (see also i2cfast) 2353 2354 CONFIG_I2C_MULTI_BUS 2355 2356 This option allows the use of multiple I2C buses, each of which 2357 must have a controller. At any point in time, only one bus is 2358 active. To switch to a different bus, use the 'i2c dev' command. 2359 Note that bus numbering is zero-based. 2360 2361 CONFIG_SYS_I2C_NOPROBES 2362 2363 This option specifies a list of I2C devices that will be skipped 2364 when the 'i2c probe' command is issued. If CONFIG_I2C_MULTI_BUS 2365 is set, specify a list of bus-device pairs. Otherwise, specify 2366 a 1D array of device addresses 2367 2368 e.g. 2369 #undef CONFIG_I2C_MULTI_BUS 2370 #define CONFIG_SYS_I2C_NOPROBES {0x50,0x68} 2371 2372 will skip addresses 0x50 and 0x68 on a board with one I2C bus 2373 2374 #define CONFIG_I2C_MULTI_BUS 2375 #define CONFIG_SYS_I2C_NOPROBES {{0,0x50},{0,0x68},{1,0x54}} 2376 2377 will skip addresses 0x50 and 0x68 on bus 0 and address 0x54 on bus 1 2378 2379 CONFIG_SYS_SPD_BUS_NUM 2380 2381 If defined, then this indicates the I2C bus number for DDR SPD. 2382 If not defined, then U-Boot assumes that SPD is on I2C bus 0. 2383 2384 CONFIG_SYS_RTC_BUS_NUM 2385 2386 If defined, then this indicates the I2C bus number for the RTC. 2387 If not defined, then U-Boot assumes that RTC is on I2C bus 0. 2388 2389 CONFIG_SYS_DTT_BUS_NUM 2390 2391 If defined, then this indicates the I2C bus number for the DTT. 2392 If not defined, then U-Boot assumes that DTT is on I2C bus 0. 2393 2394 CONFIG_SYS_I2C_DTT_ADDR: 2395 2396 If defined, specifies the I2C address of the DTT device. 2397 If not defined, then U-Boot uses predefined value for 2398 specified DTT device. 2399 2400 CONFIG_SOFT_I2C_READ_REPEATED_START 2401 2402 defining this will force the i2c_read() function in 2403 the soft_i2c driver to perform an I2C repeated start 2404 between writing the address pointer and reading the 2405 data. If this define is omitted the default behaviour 2406 of doing a stop-start sequence will be used. Most I2C 2407 devices can use either method, but some require one or 2408 the other. 2409 2410- SPI Support: CONFIG_SPI 2411 2412 Enables SPI driver (so far only tested with 2413 SPI EEPROM, also an instance works with Crystal A/D and 2414 D/As on the SACSng board) 2415 2416 CONFIG_SH_SPI 2417 2418 Enables the driver for SPI controller on SuperH. Currently 2419 only SH7757 is supported. 2420 2421 CONFIG_SOFT_SPI 2422 2423 Enables a software (bit-bang) SPI driver rather than 2424 using hardware support. This is a general purpose 2425 driver that only requires three general I/O port pins 2426 (two outputs, one input) to function. If this is 2427 defined, the board configuration must define several 2428 SPI configuration items (port pins to use, etc). For 2429 an example, see include/configs/sacsng.h. 2430 2431 CONFIG_HARD_SPI 2432 2433 Enables a hardware SPI driver for general-purpose reads 2434 and writes. As with CONFIG_SOFT_SPI, the board configuration 2435 must define a list of chip-select function pointers. 2436 Currently supported on some MPC8xxx processors. For an 2437 example, see include/configs/mpc8349emds.h. 2438 2439 CONFIG_MXC_SPI 2440 2441 Enables the driver for the SPI controllers on i.MX and MXC 2442 SoCs. Currently i.MX31/35/51 are supported. 2443 2444 CONFIG_SYS_SPI_MXC_WAIT 2445 Timeout for waiting until spi transfer completed. 2446 default: (CONFIG_SYS_HZ/100) /* 10 ms */ 2447 2448- FPGA Support: CONFIG_FPGA 2449 2450 Enables FPGA subsystem. 2451 2452 CONFIG_FPGA_<vendor> 2453 2454 Enables support for specific chip vendors. 2455 (ALTERA, XILINX) 2456 2457 CONFIG_FPGA_<family> 2458 2459 Enables support for FPGA family. 2460 (SPARTAN2, SPARTAN3, VIRTEX2, CYCLONE2, ACEX1K, ACEX) 2461 2462 CONFIG_FPGA_COUNT 2463 2464 Specify the number of FPGA devices to support. 2465 2466 CONFIG_CMD_FPGA_LOADMK 2467 2468 Enable support for fpga loadmk command 2469 2470 CONFIG_CMD_FPGA_LOADP 2471 2472 Enable support for fpga loadp command - load partial bitstream 2473 2474 CONFIG_CMD_FPGA_LOADBP 2475 2476 Enable support for fpga loadbp command - load partial bitstream 2477 (Xilinx only) 2478 2479 CONFIG_SYS_FPGA_PROG_FEEDBACK 2480 2481 Enable printing of hash marks during FPGA configuration. 2482 2483 CONFIG_SYS_FPGA_CHECK_BUSY 2484 2485 Enable checks on FPGA configuration interface busy 2486 status by the configuration function. This option 2487 will require a board or device specific function to 2488 be written. 2489 2490 CONFIG_FPGA_DELAY 2491 2492 If defined, a function that provides delays in the FPGA 2493 configuration driver. 2494 2495 CONFIG_SYS_FPGA_CHECK_CTRLC 2496 Allow Control-C to interrupt FPGA configuration 2497 2498 CONFIG_SYS_FPGA_CHECK_ERROR 2499 2500 Check for configuration errors during FPGA bitfile 2501 loading. For example, abort during Virtex II 2502 configuration if the INIT_B line goes low (which 2503 indicated a CRC error). 2504 2505 CONFIG_SYS_FPGA_WAIT_INIT 2506 2507 Maximum time to wait for the INIT_B line to de-assert 2508 after PROB_B has been de-asserted during a Virtex II 2509 FPGA configuration sequence. The default time is 500 2510 ms. 2511 2512 CONFIG_SYS_FPGA_WAIT_BUSY 2513 2514 Maximum time to wait for BUSY to de-assert during 2515 Virtex II FPGA configuration. The default is 5 ms. 2516 2517 CONFIG_SYS_FPGA_WAIT_CONFIG 2518 2519 Time to wait after FPGA configuration. The default is 2520 200 ms. 2521 2522- Configuration Management: 2523 CONFIG_BUILD_TARGET 2524 2525 Some SoCs need special image types (e.g. U-Boot binary 2526 with a special header) as build targets. By defining 2527 CONFIG_BUILD_TARGET in the SoC / board header, this 2528 special image will be automatically built upon calling 2529 make / buildman. 2530 2531 CONFIG_IDENT_STRING 2532 2533 If defined, this string will be added to the U-Boot 2534 version information (U_BOOT_VERSION) 2535 2536- Vendor Parameter Protection: 2537 2538 U-Boot considers the values of the environment 2539 variables "serial#" (Board Serial Number) and 2540 "ethaddr" (Ethernet Address) to be parameters that 2541 are set once by the board vendor / manufacturer, and 2542 protects these variables from casual modification by 2543 the user. Once set, these variables are read-only, 2544 and write or delete attempts are rejected. You can 2545 change this behaviour: 2546 2547 If CONFIG_ENV_OVERWRITE is #defined in your config 2548 file, the write protection for vendor parameters is 2549 completely disabled. Anybody can change or delete 2550 these parameters. 2551 2552 Alternatively, if you define _both_ an ethaddr in the 2553 default env _and_ CONFIG_OVERWRITE_ETHADDR_ONCE, a default 2554 Ethernet address is installed in the environment, 2555 which can be changed exactly ONCE by the user. [The 2556 serial# is unaffected by this, i. e. it remains 2557 read-only.] 2558 2559 The same can be accomplished in a more flexible way 2560 for any variable by configuring the type of access 2561 to allow for those variables in the ".flags" variable 2562 or define CONFIG_ENV_FLAGS_LIST_STATIC. 2563 2564- Protected RAM: 2565 CONFIG_PRAM 2566 2567 Define this variable to enable the reservation of 2568 "protected RAM", i. e. RAM which is not overwritten 2569 by U-Boot. Define CONFIG_PRAM to hold the number of 2570 kB you want to reserve for pRAM. You can overwrite 2571 this default value by defining an environment 2572 variable "pram" to the number of kB you want to 2573 reserve. Note that the board info structure will 2574 still show the full amount of RAM. If pRAM is 2575 reserved, a new environment variable "mem" will 2576 automatically be defined to hold the amount of 2577 remaining RAM in a form that can be passed as boot 2578 argument to Linux, for instance like that: 2579 2580 setenv bootargs ... mem=\${mem} 2581 saveenv 2582 2583 This way you can tell Linux not to use this memory, 2584 either, which results in a memory region that will 2585 not be affected by reboots. 2586 2587 *WARNING* If your board configuration uses automatic 2588 detection of the RAM size, you must make sure that 2589 this memory test is non-destructive. So far, the 2590 following board configurations are known to be 2591 "pRAM-clean": 2592 2593 IVMS8, IVML24, SPD8xx, TQM8xxL, 2594 HERMES, IP860, RPXlite, LWMON, 2595 FLAGADM, TQM8260 2596 2597- Access to physical memory region (> 4GB) 2598 Some basic support is provided for operations on memory not 2599 normally accessible to U-Boot - e.g. some architectures 2600 support access to more than 4GB of memory on 32-bit 2601 machines using physical address extension or similar. 2602 Define CONFIG_PHYSMEM to access this basic support, which 2603 currently only supports clearing the memory. 2604 2605- Error Recovery: 2606 CONFIG_PANIC_HANG 2607 2608 Define this variable to stop the system in case of a 2609 fatal error, so that you have to reset it manually. 2610 This is probably NOT a good idea for an embedded 2611 system where you want the system to reboot 2612 automatically as fast as possible, but it may be 2613 useful during development since you can try to debug 2614 the conditions that lead to the situation. 2615 2616 CONFIG_NET_RETRY_COUNT 2617 2618 This variable defines the number of retries for 2619 network operations like ARP, RARP, TFTP, or BOOTP 2620 before giving up the operation. If not defined, a 2621 default value of 5 is used. 2622 2623 CONFIG_ARP_TIMEOUT 2624 2625 Timeout waiting for an ARP reply in milliseconds. 2626 2627 CONFIG_NFS_TIMEOUT 2628 2629 Timeout in milliseconds used in NFS protocol. 2630 If you encounter "ERROR: Cannot umount" in nfs command, 2631 try longer timeout such as 2632 #define CONFIG_NFS_TIMEOUT 10000UL 2633 2634- Command Interpreter: 2635 CONFIG_AUTO_COMPLETE 2636 2637 Enable auto completion of commands using TAB. 2638 2639 CONFIG_SYS_PROMPT_HUSH_PS2 2640 2641 This defines the secondary prompt string, which is 2642 printed when the command interpreter needs more input 2643 to complete a command. Usually "> ". 2644 2645 Note: 2646 2647 In the current implementation, the local variables 2648 space and global environment variables space are 2649 separated. Local variables are those you define by 2650 simply typing `name=value'. To access a local 2651 variable later on, you have write `$name' or 2652 `${name}'; to execute the contents of a variable 2653 directly type `$name' at the command prompt. 2654 2655 Global environment variables are those you use 2656 setenv/printenv to work with. To run a command stored 2657 in such a variable, you need to use the run command, 2658 and you must not use the '$' sign to access them. 2659 2660 To store commands and special characters in a 2661 variable, please use double quotation marks 2662 surrounding the whole text of the variable, instead 2663 of the backslashes before semicolons and special 2664 symbols. 2665 2666- Command Line Editing and History: 2667 CONFIG_CMDLINE_EDITING 2668 2669 Enable editing and History functions for interactive 2670 command line input operations 2671 2672- Command Line PS1/PS2 support: 2673 CONFIG_CMDLINE_PS_SUPPORT 2674 2675 Enable support for changing the command prompt string 2676 at run-time. Only static string is supported so far. 2677 The string is obtained from environment variables PS1 2678 and PS2. 2679 2680- Default Environment: 2681 CONFIG_EXTRA_ENV_SETTINGS 2682 2683 Define this to contain any number of null terminated 2684 strings (variable = value pairs) that will be part of 2685 the default environment compiled into the boot image. 2686 2687 For example, place something like this in your 2688 board's config file: 2689 2690 #define CONFIG_EXTRA_ENV_SETTINGS \ 2691 "myvar1=value1\0" \ 2692 "myvar2=value2\0" 2693 2694 Warning: This method is based on knowledge about the 2695 internal format how the environment is stored by the 2696 U-Boot code. This is NOT an official, exported 2697 interface! Although it is unlikely that this format 2698 will change soon, there is no guarantee either. 2699 You better know what you are doing here. 2700 2701 Note: overly (ab)use of the default environment is 2702 discouraged. Make sure to check other ways to preset 2703 the environment like the "source" command or the 2704 boot command first. 2705 2706 CONFIG_ENV_VARS_UBOOT_CONFIG 2707 2708 Define this in order to add variables describing the 2709 U-Boot build configuration to the default environment. 2710 These will be named arch, cpu, board, vendor, and soc. 2711 2712 Enabling this option will cause the following to be defined: 2713 2714 - CONFIG_SYS_ARCH 2715 - CONFIG_SYS_CPU 2716 - CONFIG_SYS_BOARD 2717 - CONFIG_SYS_VENDOR 2718 - CONFIG_SYS_SOC 2719 2720 CONFIG_ENV_VARS_UBOOT_RUNTIME_CONFIG 2721 2722 Define this in order to add variables describing certain 2723 run-time determined information about the hardware to the 2724 environment. These will be named board_name, board_rev. 2725 2726 CONFIG_DELAY_ENVIRONMENT 2727 2728 Normally the environment is loaded when the board is 2729 initialised so that it is available to U-Boot. This inhibits 2730 that so that the environment is not available until 2731 explicitly loaded later by U-Boot code. With CONFIG_OF_CONTROL 2732 this is instead controlled by the value of 2733 /config/load-environment. 2734 2735- DataFlash Support: 2736 CONFIG_HAS_DATAFLASH 2737 2738 Defining this option enables DataFlash features and 2739 allows to read/write in Dataflash via the standard 2740 commands cp, md... 2741 2742- Serial Flash support 2743 CONFIG_CMD_SF 2744 2745 Defining this option enables SPI flash commands 2746 'sf probe/read/write/erase/update'. 2747 2748 Usage requires an initial 'probe' to define the serial 2749 flash parameters, followed by read/write/erase/update 2750 commands. 2751 2752 The following defaults may be provided by the platform 2753 to handle the common case when only a single serial 2754 flash is present on the system. 2755 2756 CONFIG_SF_DEFAULT_BUS Bus identifier 2757 CONFIG_SF_DEFAULT_CS Chip-select 2758 CONFIG_SF_DEFAULT_MODE (see include/spi.h) 2759 CONFIG_SF_DEFAULT_SPEED in Hz 2760 2761 CONFIG_CMD_SF_TEST 2762 2763 Define this option to include a destructive SPI flash 2764 test ('sf test'). 2765 2766 CONFIG_SF_DUAL_FLASH Dual flash memories 2767 2768 Define this option to use dual flash support where two flash 2769 memories can be connected with a given cs line. 2770 Currently Xilinx Zynq qspi supports these type of connections. 2771 2772- SystemACE Support: 2773 CONFIG_SYSTEMACE 2774 2775 Adding this option adds support for Xilinx SystemACE 2776 chips attached via some sort of local bus. The address 2777 of the chip must also be defined in the 2778 CONFIG_SYS_SYSTEMACE_BASE macro. For example: 2779 2780 #define CONFIG_SYSTEMACE 2781 #define CONFIG_SYS_SYSTEMACE_BASE 0xf0000000 2782 2783 When SystemACE support is added, the "ace" device type 2784 becomes available to the fat commands, i.e. fatls. 2785 2786- TFTP Fixed UDP Port: 2787 CONFIG_TFTP_PORT 2788 2789 If this is defined, the environment variable tftpsrcp 2790 is used to supply the TFTP UDP source port value. 2791 If tftpsrcp isn't defined, the normal pseudo-random port 2792 number generator is used. 2793 2794 Also, the environment variable tftpdstp is used to supply 2795 the TFTP UDP destination port value. If tftpdstp isn't 2796 defined, the normal port 69 is used. 2797 2798 The purpose for tftpsrcp is to allow a TFTP server to 2799 blindly start the TFTP transfer using the pre-configured 2800 target IP address and UDP port. This has the effect of 2801 "punching through" the (Windows XP) firewall, allowing 2802 the remainder of the TFTP transfer to proceed normally. 2803 A better solution is to properly configure the firewall, 2804 but sometimes that is not allowed. 2805 2806- Hashing support: 2807 CONFIG_CMD_HASH 2808 2809 This enables a generic 'hash' command which can produce 2810 hashes / digests from a few algorithms (e.g. SHA1, SHA256). 2811 2812 CONFIG_HASH_VERIFY 2813 2814 Enable the hash verify command (hash -v). This adds to code 2815 size a little. 2816 2817 CONFIG_SHA1 - This option enables support of hashing using SHA1 2818 algorithm. The hash is calculated in software. 2819 CONFIG_SHA256 - This option enables support of hashing using 2820 SHA256 algorithm. The hash is calculated in software. 2821 CONFIG_SHA_HW_ACCEL - This option enables hardware acceleration 2822 for SHA1/SHA256 hashing. 2823 This affects the 'hash' command and also the 2824 hash_lookup_algo() function. 2825 CONFIG_SHA_PROG_HW_ACCEL - This option enables 2826 hardware-acceleration for SHA1/SHA256 progressive hashing. 2827 Data can be streamed in a block at a time and the hashing 2828 is performed in hardware. 2829 2830 Note: There is also a sha1sum command, which should perhaps 2831 be deprecated in favour of 'hash sha1'. 2832 2833- Freescale i.MX specific commands: 2834 CONFIG_CMD_HDMIDETECT 2835 This enables 'hdmidet' command which returns true if an 2836 HDMI monitor is detected. This command is i.MX 6 specific. 2837 2838- bootcount support: 2839 CONFIG_BOOTCOUNT_LIMIT 2840 2841 This enables the bootcounter support, see: 2842 http://www.denx.de/wiki/DULG/UBootBootCountLimit 2843 2844 CONFIG_AT91SAM9XE 2845 enable special bootcounter support on at91sam9xe based boards. 2846 CONFIG_SOC_DA8XX 2847 enable special bootcounter support on da850 based boards. 2848 CONFIG_BOOTCOUNT_RAM 2849 enable support for the bootcounter in RAM 2850 CONFIG_BOOTCOUNT_I2C 2851 enable support for the bootcounter on an i2c (like RTC) device. 2852 CONFIG_SYS_I2C_RTC_ADDR = i2c chip address 2853 CONFIG_SYS_BOOTCOUNT_ADDR = i2c addr which is used for 2854 the bootcounter. 2855 CONFIG_BOOTCOUNT_ALEN = address len 2856 2857- Show boot progress: 2858 CONFIG_SHOW_BOOT_PROGRESS 2859 2860 Defining this option allows to add some board- 2861 specific code (calling a user-provided function 2862 "show_boot_progress(int)") that enables you to show 2863 the system's boot progress on some display (for 2864 example, some LED's) on your board. At the moment, 2865 the following checkpoints are implemented: 2866 2867 2868Legacy uImage format: 2869 2870 Arg Where When 2871 1 common/cmd_bootm.c before attempting to boot an image 2872 -1 common/cmd_bootm.c Image header has bad magic number 2873 2 common/cmd_bootm.c Image header has correct magic number 2874 -2 common/cmd_bootm.c Image header has bad checksum 2875 3 common/cmd_bootm.c Image header has correct checksum 2876 -3 common/cmd_bootm.c Image data has bad checksum 2877 4 common/cmd_bootm.c Image data has correct checksum 2878 -4 common/cmd_bootm.c Image is for unsupported architecture 2879 5 common/cmd_bootm.c Architecture check OK 2880 -5 common/cmd_bootm.c Wrong Image Type (not kernel, multi) 2881 6 common/cmd_bootm.c Image Type check OK 2882 -6 common/cmd_bootm.c gunzip uncompression error 2883 -7 common/cmd_bootm.c Unimplemented compression type 2884 7 common/cmd_bootm.c Uncompression OK 2885 8 common/cmd_bootm.c No uncompress/copy overwrite error 2886 -9 common/cmd_bootm.c Unsupported OS (not Linux, BSD, VxWorks, QNX) 2887 2888 9 common/image.c Start initial ramdisk verification 2889 -10 common/image.c Ramdisk header has bad magic number 2890 -11 common/image.c Ramdisk header has bad checksum 2891 10 common/image.c Ramdisk header is OK 2892 -12 common/image.c Ramdisk data has bad checksum 2893 11 common/image.c Ramdisk data has correct checksum 2894 12 common/image.c Ramdisk verification complete, start loading 2895 -13 common/image.c Wrong Image Type (not PPC Linux ramdisk) 2896 13 common/image.c Start multifile image verification 2897 14 common/image.c No initial ramdisk, no multifile, continue. 2898 2899 15 arch/<arch>/lib/bootm.c All preparation done, transferring control to OS 2900 2901 -30 arch/powerpc/lib/board.c Fatal error, hang the system 2902 -31 post/post.c POST test failed, detected by post_output_backlog() 2903 -32 post/post.c POST test failed, detected by post_run_single() 2904 2905 34 common/cmd_doc.c before loading a Image from a DOC device 2906 -35 common/cmd_doc.c Bad usage of "doc" command 2907 35 common/cmd_doc.c correct usage of "doc" command 2908 -36 common/cmd_doc.c No boot device 2909 36 common/cmd_doc.c correct boot device 2910 -37 common/cmd_doc.c Unknown Chip ID on boot device 2911 37 common/cmd_doc.c correct chip ID found, device available 2912 -38 common/cmd_doc.c Read Error on boot device 2913 38 common/cmd_doc.c reading Image header from DOC device OK 2914 -39 common/cmd_doc.c Image header has bad magic number 2915 39 common/cmd_doc.c Image header has correct magic number 2916 -40 common/cmd_doc.c Error reading Image from DOC device 2917 40 common/cmd_doc.c Image header has correct magic number 2918 41 common/cmd_ide.c before loading a Image from a IDE device 2919 -42 common/cmd_ide.c Bad usage of "ide" command 2920 42 common/cmd_ide.c correct usage of "ide" command 2921 -43 common/cmd_ide.c No boot device 2922 43 common/cmd_ide.c boot device found 2923 -44 common/cmd_ide.c Device not available 2924 44 common/cmd_ide.c Device available 2925 -45 common/cmd_ide.c wrong partition selected 2926 45 common/cmd_ide.c partition selected 2927 -46 common/cmd_ide.c Unknown partition table 2928 46 common/cmd_ide.c valid partition table found 2929 -47 common/cmd_ide.c Invalid partition type 2930 47 common/cmd_ide.c correct partition type 2931 -48 common/cmd_ide.c Error reading Image Header on boot device 2932 48 common/cmd_ide.c reading Image Header from IDE device OK 2933 -49 common/cmd_ide.c Image header has bad magic number 2934 49 common/cmd_ide.c Image header has correct magic number 2935 -50 common/cmd_ide.c Image header has bad checksum 2936 50 common/cmd_ide.c Image header has correct checksum 2937 -51 common/cmd_ide.c Error reading Image from IDE device 2938 51 common/cmd_ide.c reading Image from IDE device OK 2939 52 common/cmd_nand.c before loading a Image from a NAND device 2940 -53 common/cmd_nand.c Bad usage of "nand" command 2941 53 common/cmd_nand.c correct usage of "nand" command 2942 -54 common/cmd_nand.c No boot device 2943 54 common/cmd_nand.c boot device found 2944 -55 common/cmd_nand.c Unknown Chip ID on boot device 2945 55 common/cmd_nand.c correct chip ID found, device available 2946 -56 common/cmd_nand.c Error reading Image Header on boot device 2947 56 common/cmd_nand.c reading Image Header from NAND device OK 2948 -57 common/cmd_nand.c Image header has bad magic number 2949 57 common/cmd_nand.c Image header has correct magic number 2950 -58 common/cmd_nand.c Error reading Image from NAND device 2951 58 common/cmd_nand.c reading Image from NAND device OK 2952 2953 -60 common/env_common.c Environment has a bad CRC, using default 2954 2955 64 net/eth.c starting with Ethernet configuration. 2956 -64 net/eth.c no Ethernet found. 2957 65 net/eth.c Ethernet found. 2958 2959 -80 common/cmd_net.c usage wrong 2960 80 common/cmd_net.c before calling net_loop() 2961 -81 common/cmd_net.c some error in net_loop() occurred 2962 81 common/cmd_net.c net_loop() back without error 2963 -82 common/cmd_net.c size == 0 (File with size 0 loaded) 2964 82 common/cmd_net.c trying automatic boot 2965 83 common/cmd_net.c running "source" command 2966 -83 common/cmd_net.c some error in automatic boot or "source" command 2967 84 common/cmd_net.c end without errors 2968 2969FIT uImage format: 2970 2971 Arg Where When 2972 100 common/cmd_bootm.c Kernel FIT Image has correct format 2973 -100 common/cmd_bootm.c Kernel FIT Image has incorrect format 2974 101 common/cmd_bootm.c No Kernel subimage unit name, using configuration 2975 -101 common/cmd_bootm.c Can't get configuration for kernel subimage 2976 102 common/cmd_bootm.c Kernel unit name specified 2977 -103 common/cmd_bootm.c Can't get kernel subimage node offset 2978 103 common/cmd_bootm.c Found configuration node 2979 104 common/cmd_bootm.c Got kernel subimage node offset 2980 -104 common/cmd_bootm.c Kernel subimage hash verification failed 2981 105 common/cmd_bootm.c Kernel subimage hash verification OK 2982 -105 common/cmd_bootm.c Kernel subimage is for unsupported architecture 2983 106 common/cmd_bootm.c Architecture check OK 2984 -106 common/cmd_bootm.c Kernel subimage has wrong type 2985 107 common/cmd_bootm.c Kernel subimage type OK 2986 -107 common/cmd_bootm.c Can't get kernel subimage data/size 2987 108 common/cmd_bootm.c Got kernel subimage data/size 2988 -108 common/cmd_bootm.c Wrong image type (not legacy, FIT) 2989 -109 common/cmd_bootm.c Can't get kernel subimage type 2990 -110 common/cmd_bootm.c Can't get kernel subimage comp 2991 -111 common/cmd_bootm.c Can't get kernel subimage os 2992 -112 common/cmd_bootm.c Can't get kernel subimage load address 2993 -113 common/cmd_bootm.c Image uncompress/copy overwrite error 2994 2995 120 common/image.c Start initial ramdisk verification 2996 -120 common/image.c Ramdisk FIT image has incorrect format 2997 121 common/image.c Ramdisk FIT image has correct format 2998 122 common/image.c No ramdisk subimage unit name, using configuration 2999 -122 common/image.c Can't get configuration for ramdisk subimage 3000 123 common/image.c Ramdisk unit name specified 3001 -124 common/image.c Can't get ramdisk subimage node offset 3002 125 common/image.c Got ramdisk subimage node offset 3003 -125 common/image.c Ramdisk subimage hash verification failed 3004 126 common/image.c Ramdisk subimage hash verification OK 3005 -126 common/image.c Ramdisk subimage for unsupported architecture 3006 127 common/image.c Architecture check OK 3007 -127 common/image.c Can't get ramdisk subimage data/size 3008 128 common/image.c Got ramdisk subimage data/size 3009 129 common/image.c Can't get ramdisk load address 3010 -129 common/image.c Got ramdisk load address 3011 3012 -130 common/cmd_doc.c Incorrect FIT image format 3013 131 common/cmd_doc.c FIT image format OK 3014 3015 -140 common/cmd_ide.c Incorrect FIT image format 3016 141 common/cmd_ide.c FIT image format OK 3017 3018 -150 common/cmd_nand.c Incorrect FIT image format 3019 151 common/cmd_nand.c FIT image format OK 3020 3021- legacy image format: 3022 CONFIG_IMAGE_FORMAT_LEGACY 3023 enables the legacy image format support in U-Boot. 3024 3025 Default: 3026 enabled if CONFIG_FIT_SIGNATURE is not defined. 3027 3028 CONFIG_DISABLE_IMAGE_LEGACY 3029 disable the legacy image format 3030 3031 This define is introduced, as the legacy image format is 3032 enabled per default for backward compatibility. 3033 3034- FIT image support: 3035 CONFIG_FIT_DISABLE_SHA256 3036 Supporting SHA256 hashes has quite an impact on binary size. 3037 For constrained systems sha256 hash support can be disabled 3038 with this option. 3039 3040 TODO(sjg@chromium.org): Adjust this option to be positive, 3041 and move it to Kconfig 3042 3043- Standalone program support: 3044 CONFIG_STANDALONE_LOAD_ADDR 3045 3046 This option defines a board specific value for the 3047 address where standalone program gets loaded, thus 3048 overwriting the architecture dependent default 3049 settings. 3050 3051- Frame Buffer Address: 3052 CONFIG_FB_ADDR 3053 3054 Define CONFIG_FB_ADDR if you want to use specific 3055 address for frame buffer. This is typically the case 3056 when using a graphics controller has separate video 3057 memory. U-Boot will then place the frame buffer at 3058 the given address instead of dynamically reserving it 3059 in system RAM by calling lcd_setmem(), which grabs 3060 the memory for the frame buffer depending on the 3061 configured panel size. 3062 3063 Please see board_init_f function. 3064 3065- Automatic software updates via TFTP server 3066 CONFIG_UPDATE_TFTP 3067 CONFIG_UPDATE_TFTP_CNT_MAX 3068 CONFIG_UPDATE_TFTP_MSEC_MAX 3069 3070 These options enable and control the auto-update feature; 3071 for a more detailed description refer to doc/README.update. 3072 3073- MTD Support (mtdparts command, UBI support) 3074 CONFIG_MTD_DEVICE 3075 3076 Adds the MTD device infrastructure from the Linux kernel. 3077 Needed for mtdparts command support. 3078 3079 CONFIG_MTD_PARTITIONS 3080 3081 Adds the MTD partitioning infrastructure from the Linux 3082 kernel. Needed for UBI support. 3083 3084- UBI support 3085 CONFIG_CMD_UBI 3086 3087 Adds commands for interacting with MTD partitions formatted 3088 with the UBI flash translation layer 3089 3090 Requires also defining CONFIG_RBTREE 3091 3092 CONFIG_UBI_SILENCE_MSG 3093 3094 Make the verbose messages from UBI stop printing. This leaves 3095 warnings and errors enabled. 3096 3097 3098 CONFIG_MTD_UBI_WL_THRESHOLD 3099 This parameter defines the maximum difference between the highest 3100 erase counter value and the lowest erase counter value of eraseblocks 3101 of UBI devices. When this threshold is exceeded, UBI starts performing 3102 wear leveling by means of moving data from eraseblock with low erase 3103 counter to eraseblocks with high erase counter. 3104 3105 The default value should be OK for SLC NAND flashes, NOR flashes and 3106 other flashes which have eraseblock life-cycle 100000 or more. 3107 However, in case of MLC NAND flashes which typically have eraseblock 3108 life-cycle less than 10000, the threshold should be lessened (e.g., 3109 to 128 or 256, although it does not have to be power of 2). 3110 3111 default: 4096 3112 3113 CONFIG_MTD_UBI_BEB_LIMIT 3114 This option specifies the maximum bad physical eraseblocks UBI 3115 expects on the MTD device (per 1024 eraseblocks). If the 3116 underlying flash does not admit of bad eraseblocks (e.g. NOR 3117 flash), this value is ignored. 3118 3119 NAND datasheets often specify the minimum and maximum NVM 3120 (Number of Valid Blocks) for the flashes' endurance lifetime. 3121 The maximum expected bad eraseblocks per 1024 eraseblocks 3122 then can be calculated as "1024 * (1 - MinNVB / MaxNVB)", 3123 which gives 20 for most NANDs (MaxNVB is basically the total 3124 count of eraseblocks on the chip). 3125 3126 To put it differently, if this value is 20, UBI will try to 3127 reserve about 1.9% of physical eraseblocks for bad blocks 3128 handling. And that will be 1.9% of eraseblocks on the entire 3129 NAND chip, not just the MTD partition UBI attaches. This means 3130 that if you have, say, a NAND flash chip admits maximum 40 bad 3131 eraseblocks, and it is split on two MTD partitions of the same 3132 size, UBI will reserve 40 eraseblocks when attaching a 3133 partition. 3134 3135 default: 20 3136 3137 CONFIG_MTD_UBI_FASTMAP 3138 Fastmap is a mechanism which allows attaching an UBI device 3139 in nearly constant time. Instead of scanning the whole MTD device it 3140 only has to locate a checkpoint (called fastmap) on the device. 3141 The on-flash fastmap contains all information needed to attach 3142 the device. Using fastmap makes only sense on large devices where 3143 attaching by scanning takes long. UBI will not automatically install 3144 a fastmap on old images, but you can set the UBI parameter 3145 CONFIG_MTD_UBI_FASTMAP_AUTOCONVERT to 1 if you want so. Please note 3146 that fastmap-enabled images are still usable with UBI implementations 3147 without fastmap support. On typical flash devices the whole fastmap 3148 fits into one PEB. UBI will reserve PEBs to hold two fastmaps. 3149 3150 CONFIG_MTD_UBI_FASTMAP_AUTOCONVERT 3151 Set this parameter to enable fastmap automatically on images 3152 without a fastmap. 3153 default: 0 3154 3155 CONFIG_MTD_UBI_FM_DEBUG 3156 Enable UBI fastmap debug 3157 default: 0 3158 3159- UBIFS support 3160 CONFIG_CMD_UBIFS 3161 3162 Adds commands for interacting with UBI volumes formatted as 3163 UBIFS. UBIFS is read-only in u-boot. 3164 3165 Requires UBI support as well as CONFIG_LZO 3166 3167 CONFIG_UBIFS_SILENCE_MSG 3168 3169 Make the verbose messages from UBIFS stop printing. This leaves 3170 warnings and errors enabled. 3171 3172- SPL framework 3173 CONFIG_SPL 3174 Enable building of SPL globally. 3175 3176 CONFIG_SPL_LDSCRIPT 3177 LDSCRIPT for linking the SPL binary. 3178 3179 CONFIG_SPL_MAX_FOOTPRINT 3180 Maximum size in memory allocated to the SPL, BSS included. 3181 When defined, the linker checks that the actual memory 3182 used by SPL from _start to __bss_end does not exceed it. 3183 CONFIG_SPL_MAX_FOOTPRINT and CONFIG_SPL_BSS_MAX_SIZE 3184 must not be both defined at the same time. 3185 3186 CONFIG_SPL_MAX_SIZE 3187 Maximum size of the SPL image (text, data, rodata, and 3188 linker lists sections), BSS excluded. 3189 When defined, the linker checks that the actual size does 3190 not exceed it. 3191 3192 CONFIG_SPL_TEXT_BASE 3193 TEXT_BASE for linking the SPL binary. 3194 3195 CONFIG_SPL_RELOC_TEXT_BASE 3196 Address to relocate to. If unspecified, this is equal to 3197 CONFIG_SPL_TEXT_BASE (i.e. no relocation is done). 3198 3199 CONFIG_SPL_BSS_START_ADDR 3200 Link address for the BSS within the SPL binary. 3201 3202 CONFIG_SPL_BSS_MAX_SIZE 3203 Maximum size in memory allocated to the SPL BSS. 3204 When defined, the linker checks that the actual memory used 3205 by SPL from __bss_start to __bss_end does not exceed it. 3206 CONFIG_SPL_MAX_FOOTPRINT and CONFIG_SPL_BSS_MAX_SIZE 3207 must not be both defined at the same time. 3208 3209 CONFIG_SPL_STACK 3210 Adress of the start of the stack SPL will use 3211 3212 CONFIG_SPL_PANIC_ON_RAW_IMAGE 3213 When defined, SPL will panic() if the image it has 3214 loaded does not have a signature. 3215 Defining this is useful when code which loads images 3216 in SPL cannot guarantee that absolutely all read errors 3217 will be caught. 3218 An example is the LPC32XX MLC NAND driver, which will 3219 consider that a completely unreadable NAND block is bad, 3220 and thus should be skipped silently. 3221 3222 CONFIG_SPL_RELOC_STACK 3223 Adress of the start of the stack SPL will use after 3224 relocation. If unspecified, this is equal to 3225 CONFIG_SPL_STACK. 3226 3227 CONFIG_SYS_SPL_MALLOC_START 3228 Starting address of the malloc pool used in SPL. 3229 When this option is set the full malloc is used in SPL and 3230 it is set up by spl_init() and before that, the simple malloc() 3231 can be used if CONFIG_SYS_MALLOC_F is defined. 3232 3233 CONFIG_SYS_SPL_MALLOC_SIZE 3234 The size of the malloc pool used in SPL. 3235 3236 CONFIG_SPL_FRAMEWORK 3237 Enable the SPL framework under common/. This framework 3238 supports MMC, NAND and YMODEM loading of U-Boot and NAND 3239 NAND loading of the Linux Kernel. 3240 3241 CONFIG_SPL_OS_BOOT 3242 Enable booting directly to an OS from SPL. 3243 See also: doc/README.falcon 3244 3245 CONFIG_SPL_DISPLAY_PRINT 3246 For ARM, enable an optional function to print more information 3247 about the running system. 3248 3249 CONFIG_SPL_INIT_MINIMAL 3250 Arch init code should be built for a very small image 3251 3252 CONFIG_SYS_MMCSD_RAW_MODE_U_BOOT_PARTITION 3253 Partition on the MMC to load U-Boot from when the MMC is being 3254 used in raw mode 3255 3256 CONFIG_SYS_MMCSD_RAW_MODE_KERNEL_SECTOR 3257 Sector to load kernel uImage from when MMC is being 3258 used in raw mode (for Falcon mode) 3259 3260 CONFIG_SYS_MMCSD_RAW_MODE_ARGS_SECTOR, 3261 CONFIG_SYS_MMCSD_RAW_MODE_ARGS_SECTORS 3262 Sector and number of sectors to load kernel argument 3263 parameters from when MMC is being used in raw mode 3264 (for falcon mode) 3265 3266 CONFIG_SYS_MMCSD_FS_BOOT_PARTITION 3267 Partition on the MMC to load U-Boot from when the MMC is being 3268 used in fs mode 3269 3270 CONFIG_SPL_FS_LOAD_PAYLOAD_NAME 3271 Filename to read to load U-Boot when reading from filesystem 3272 3273 CONFIG_SPL_FS_LOAD_KERNEL_NAME 3274 Filename to read to load kernel uImage when reading 3275 from filesystem (for Falcon mode) 3276 3277 CONFIG_SPL_FS_LOAD_ARGS_NAME 3278 Filename to read to load kernel argument parameters 3279 when reading from filesystem (for Falcon mode) 3280 3281 CONFIG_SPL_MPC83XX_WAIT_FOR_NAND 3282 Set this for NAND SPL on PPC mpc83xx targets, so that 3283 start.S waits for the rest of the SPL to load before 3284 continuing (the hardware starts execution after just 3285 loading the first page rather than the full 4K). 3286 3287 CONFIG_SPL_SKIP_RELOCATE 3288 Avoid SPL relocation 3289 3290 CONFIG_SPL_NAND_BASE 3291 Include nand_base.c in the SPL. Requires 3292 CONFIG_SPL_NAND_DRIVERS. 3293 3294 CONFIG_SPL_NAND_DRIVERS 3295 SPL uses normal NAND drivers, not minimal drivers. 3296 3297 CONFIG_SPL_NAND_ECC 3298 Include standard software ECC in the SPL 3299 3300 CONFIG_SPL_NAND_SIMPLE 3301 Support for NAND boot using simple NAND drivers that 3302 expose the cmd_ctrl() interface. 3303 3304 CONFIG_SPL_UBI 3305 Support for a lightweight UBI (fastmap) scanner and 3306 loader 3307 3308 CONFIG_SPL_NAND_RAW_ONLY 3309 Support to boot only raw u-boot.bin images. Use this only 3310 if you need to save space. 3311 3312 CONFIG_SPL_COMMON_INIT_DDR 3313 Set for common ddr init with serial presence detect in 3314 SPL binary. 3315 3316 CONFIG_SYS_NAND_5_ADDR_CYCLE, CONFIG_SYS_NAND_PAGE_COUNT, 3317 CONFIG_SYS_NAND_PAGE_SIZE, CONFIG_SYS_NAND_OOBSIZE, 3318 CONFIG_SYS_NAND_BLOCK_SIZE, CONFIG_SYS_NAND_BAD_BLOCK_POS, 3319 CONFIG_SYS_NAND_ECCPOS, CONFIG_SYS_NAND_ECCSIZE, 3320 CONFIG_SYS_NAND_ECCBYTES 3321 Defines the size and behavior of the NAND that SPL uses 3322 to read U-Boot 3323 3324 CONFIG_SPL_NAND_BOOT 3325 Add support NAND boot 3326 3327 CONFIG_SYS_NAND_U_BOOT_OFFS 3328 Location in NAND to read U-Boot from 3329 3330 CONFIG_SYS_NAND_U_BOOT_DST 3331 Location in memory to load U-Boot to 3332 3333 CONFIG_SYS_NAND_U_BOOT_SIZE 3334 Size of image to load 3335 3336 CONFIG_SYS_NAND_U_BOOT_START 3337 Entry point in loaded image to jump to 3338 3339 CONFIG_SYS_NAND_HW_ECC_OOBFIRST 3340 Define this if you need to first read the OOB and then the 3341 data. This is used, for example, on davinci platforms. 3342 3343 CONFIG_SPL_OMAP3_ID_NAND 3344 Support for an OMAP3-specific set of functions to return the 3345 ID and MFR of the first attached NAND chip, if present. 3346 3347 CONFIG_SPL_RAM_DEVICE 3348 Support for running image already present in ram, in SPL binary 3349 3350 CONFIG_SPL_PAD_TO 3351 Image offset to which the SPL should be padded before appending 3352 the SPL payload. By default, this is defined as 3353 CONFIG_SPL_MAX_SIZE, or 0 if CONFIG_SPL_MAX_SIZE is undefined. 3354 CONFIG_SPL_PAD_TO must be either 0, meaning to append the SPL 3355 payload without any padding, or >= CONFIG_SPL_MAX_SIZE. 3356 3357 CONFIG_SPL_TARGET 3358 Final target image containing SPL and payload. Some SPLs 3359 use an arch-specific makefile fragment instead, for 3360 example if more than one image needs to be produced. 3361 3362 CONFIG_FIT_SPL_PRINT 3363 Printing information about a FIT image adds quite a bit of 3364 code to SPL. So this is normally disabled in SPL. Use this 3365 option to re-enable it. This will affect the output of the 3366 bootm command when booting a FIT image. 3367 3368- TPL framework 3369 CONFIG_TPL 3370 Enable building of TPL globally. 3371 3372 CONFIG_TPL_PAD_TO 3373 Image offset to which the TPL should be padded before appending 3374 the TPL payload. By default, this is defined as 3375 CONFIG_SPL_MAX_SIZE, or 0 if CONFIG_SPL_MAX_SIZE is undefined. 3376 CONFIG_SPL_PAD_TO must be either 0, meaning to append the SPL 3377 payload without any padding, or >= CONFIG_SPL_MAX_SIZE. 3378 3379- Interrupt support (PPC): 3380 3381 There are common interrupt_init() and timer_interrupt() 3382 for all PPC archs. interrupt_init() calls interrupt_init_cpu() 3383 for CPU specific initialization. interrupt_init_cpu() 3384 should set decrementer_count to appropriate value. If 3385 CPU resets decrementer automatically after interrupt 3386 (ppc4xx) it should set decrementer_count to zero. 3387 timer_interrupt() calls timer_interrupt_cpu() for CPU 3388 specific handling. If board has watchdog / status_led 3389 / other_activity_monitor it works automatically from 3390 general timer_interrupt(). 3391 3392 3393Board initialization settings: 3394------------------------------ 3395 3396During Initialization u-boot calls a number of board specific functions 3397to allow the preparation of board specific prerequisites, e.g. pin setup 3398before drivers are initialized. To enable these callbacks the 3399following configuration macros have to be defined. Currently this is 3400architecture specific, so please check arch/your_architecture/lib/board.c 3401typically in board_init_f() and board_init_r(). 3402 3403- CONFIG_BOARD_EARLY_INIT_F: Call board_early_init_f() 3404- CONFIG_BOARD_EARLY_INIT_R: Call board_early_init_r() 3405- CONFIG_BOARD_LATE_INIT: Call board_late_init() 3406- CONFIG_BOARD_POSTCLK_INIT: Call board_postclk_init() 3407 3408Configuration Settings: 3409----------------------- 3410 3411- CONFIG_SYS_SUPPORT_64BIT_DATA: Defined automatically if compiled as 64-bit. 3412 Optionally it can be defined to support 64-bit memory commands. 3413 3414- CONFIG_SYS_LONGHELP: Defined when you want long help messages included; 3415 undefine this when you're short of memory. 3416 3417- CONFIG_SYS_HELP_CMD_WIDTH: Defined when you want to override the default 3418 width of the commands listed in the 'help' command output. 3419 3420- CONFIG_SYS_PROMPT: This is what U-Boot prints on the console to 3421 prompt for user input. 3422 3423- CONFIG_SYS_CBSIZE: Buffer size for input from the Console 3424 3425- CONFIG_SYS_PBSIZE: Buffer size for Console output 3426 3427- CONFIG_SYS_MAXARGS: max. Number of arguments accepted for monitor commands 3428 3429- CONFIG_SYS_BARGSIZE: Buffer size for Boot Arguments which are passed to 3430 the application (usually a Linux kernel) when it is 3431 booted 3432 3433- CONFIG_SYS_BAUDRATE_TABLE: 3434 List of legal baudrate settings for this board. 3435 3436- CONFIG_SYS_MEMTEST_START, CONFIG_SYS_MEMTEST_END: 3437 Begin and End addresses of the area used by the 3438 simple memory test. 3439 3440- CONFIG_SYS_ALT_MEMTEST: 3441 Enable an alternate, more extensive memory test. 3442 3443- CONFIG_SYS_MEMTEST_SCRATCH: 3444 Scratch address used by the alternate memory test 3445 You only need to set this if address zero isn't writeable 3446 3447- CONFIG_SYS_MEM_RESERVE_SECURE 3448 Only implemented for ARMv8 for now. 3449 If defined, the size of CONFIG_SYS_MEM_RESERVE_SECURE memory 3450 is substracted from total RAM and won't be reported to OS. 3451 This memory can be used as secure memory. A variable 3452 gd->arch.secure_ram is used to track the location. In systems 3453 the RAM base is not zero, or RAM is divided into banks, 3454 this variable needs to be recalcuated to get the address. 3455 3456- CONFIG_SYS_MEM_TOP_HIDE: 3457 If CONFIG_SYS_MEM_TOP_HIDE is defined in the board config header, 3458 this specified memory area will get subtracted from the top 3459 (end) of RAM and won't get "touched" at all by U-Boot. By 3460 fixing up gd->ram_size the Linux kernel should gets passed 3461 the now "corrected" memory size and won't touch it either. 3462 This should work for arch/ppc and arch/powerpc. Only Linux 3463 board ports in arch/powerpc with bootwrapper support that 3464 recalculate the memory size from the SDRAM controller setup 3465 will have to get fixed in Linux additionally. 3466 3467 This option can be used as a workaround for the 440EPx/GRx 3468 CHIP 11 errata where the last 256 bytes in SDRAM shouldn't 3469 be touched. 3470 3471 WARNING: Please make sure that this value is a multiple of 3472 the Linux page size (normally 4k). If this is not the case, 3473 then the end address of the Linux memory will be located at a 3474 non page size aligned address and this could cause major 3475 problems. 3476 3477- CONFIG_SYS_LOADS_BAUD_CHANGE: 3478 Enable temporary baudrate change while serial download 3479 3480- CONFIG_SYS_SDRAM_BASE: 3481 Physical start address of SDRAM. _Must_ be 0 here. 3482 3483- CONFIG_SYS_FLASH_BASE: 3484 Physical start address of Flash memory. 3485 3486- CONFIG_SYS_MONITOR_BASE: 3487 Physical start address of boot monitor code (set by 3488 make config files to be same as the text base address 3489 (CONFIG_SYS_TEXT_BASE) used when linking) - same as 3490 CONFIG_SYS_FLASH_BASE when booting from flash. 3491 3492- CONFIG_SYS_MONITOR_LEN: 3493 Size of memory reserved for monitor code, used to 3494 determine _at_compile_time_ (!) if the environment is 3495 embedded within the U-Boot image, or in a separate 3496 flash sector. 3497 3498- CONFIG_SYS_MALLOC_LEN: 3499 Size of DRAM reserved for malloc() use. 3500 3501- CONFIG_SYS_MALLOC_F_LEN 3502 Size of the malloc() pool for use before relocation. If 3503 this is defined, then a very simple malloc() implementation 3504 will become available before relocation. The address is just 3505 below the global data, and the stack is moved down to make 3506 space. 3507 3508 This feature allocates regions with increasing addresses 3509 within the region. calloc() is supported, but realloc() 3510 is not available. free() is supported but does nothing. 3511 The memory will be freed (or in fact just forgotten) when 3512 U-Boot relocates itself. 3513 3514- CONFIG_SYS_MALLOC_SIMPLE 3515 Provides a simple and small malloc() and calloc() for those 3516 boards which do not use the full malloc in SPL (which is 3517 enabled with CONFIG_SYS_SPL_MALLOC_START). 3518 3519- CONFIG_SYS_NONCACHED_MEMORY: 3520 Size of non-cached memory area. This area of memory will be 3521 typically located right below the malloc() area and mapped 3522 uncached in the MMU. This is useful for drivers that would 3523 otherwise require a lot of explicit cache maintenance. For 3524 some drivers it's also impossible to properly maintain the 3525 cache. For example if the regions that need to be flushed 3526 are not a multiple of the cache-line size, *and* padding 3527 cannot be allocated between the regions to align them (i.e. 3528 if the HW requires a contiguous array of regions, and the 3529 size of each region is not cache-aligned), then a flush of 3530 one region may result in overwriting data that hardware has 3531 written to another region in the same cache-line. This can 3532 happen for example in network drivers where descriptors for 3533 buffers are typically smaller than the CPU cache-line (e.g. 3534 16 bytes vs. 32 or 64 bytes). 3535 3536 Non-cached memory is only supported on 32-bit ARM at present. 3537 3538- CONFIG_SYS_BOOTM_LEN: 3539 Normally compressed uImages are limited to an 3540 uncompressed size of 8 MBytes. If this is not enough, 3541 you can define CONFIG_SYS_BOOTM_LEN in your board config file 3542 to adjust this setting to your needs. 3543 3544- CONFIG_SYS_BOOTMAPSZ: 3545 Maximum size of memory mapped by the startup code of 3546 the Linux kernel; all data that must be processed by 3547 the Linux kernel (bd_info, boot arguments, FDT blob if 3548 used) must be put below this limit, unless "bootm_low" 3549 environment variable is defined and non-zero. In such case 3550 all data for the Linux kernel must be between "bootm_low" 3551 and "bootm_low" + CONFIG_SYS_BOOTMAPSZ. The environment 3552 variable "bootm_mapsize" will override the value of 3553 CONFIG_SYS_BOOTMAPSZ. If CONFIG_SYS_BOOTMAPSZ is undefined, 3554 then the value in "bootm_size" will be used instead. 3555 3556- CONFIG_SYS_BOOT_RAMDISK_HIGH: 3557 Enable initrd_high functionality. If defined then the 3558 initrd_high feature is enabled and the bootm ramdisk subcommand 3559 is enabled. 3560 3561- CONFIG_SYS_BOOT_GET_CMDLINE: 3562 Enables allocating and saving kernel cmdline in space between 3563 "bootm_low" and "bootm_low" + BOOTMAPSZ. 3564 3565- CONFIG_SYS_BOOT_GET_KBD: 3566 Enables allocating and saving a kernel copy of the bd_info in 3567 space between "bootm_low" and "bootm_low" + BOOTMAPSZ. 3568 3569- CONFIG_SYS_MAX_FLASH_BANKS: 3570 Max number of Flash memory banks 3571 3572- CONFIG_SYS_MAX_FLASH_SECT: 3573 Max number of sectors on a Flash chip 3574 3575- CONFIG_SYS_FLASH_ERASE_TOUT: 3576 Timeout for Flash erase operations (in ms) 3577 3578- CONFIG_SYS_FLASH_WRITE_TOUT: 3579 Timeout for Flash write operations (in ms) 3580 3581- CONFIG_SYS_FLASH_LOCK_TOUT 3582 Timeout for Flash set sector lock bit operation (in ms) 3583 3584- CONFIG_SYS_FLASH_UNLOCK_TOUT 3585 Timeout for Flash clear lock bits operation (in ms) 3586 3587- CONFIG_SYS_FLASH_PROTECTION 3588 If defined, hardware flash sectors protection is used 3589 instead of U-Boot software protection. 3590 3591- CONFIG_SYS_DIRECT_FLASH_TFTP: 3592 3593 Enable TFTP transfers directly to flash memory; 3594 without this option such a download has to be 3595 performed in two steps: (1) download to RAM, and (2) 3596 copy from RAM to flash. 3597 3598 The two-step approach is usually more reliable, since 3599 you can check if the download worked before you erase 3600 the flash, but in some situations (when system RAM is 3601 too limited to allow for a temporary copy of the 3602 downloaded image) this option may be very useful. 3603 3604- CONFIG_SYS_FLASH_CFI: 3605 Define if the flash driver uses extra elements in the 3606 common flash structure for storing flash geometry. 3607 3608- CONFIG_FLASH_CFI_DRIVER 3609 This option also enables the building of the cfi_flash driver 3610 in the drivers directory 3611 3612- CONFIG_FLASH_CFI_MTD 3613 This option enables the building of the cfi_mtd driver 3614 in the drivers directory. The driver exports CFI flash 3615 to the MTD layer. 3616 3617- CONFIG_SYS_FLASH_USE_BUFFER_WRITE 3618 Use buffered writes to flash. 3619 3620- CONFIG_FLASH_SPANSION_S29WS_N 3621 s29ws-n MirrorBit flash has non-standard addresses for buffered 3622 write commands. 3623 3624- CONFIG_SYS_FLASH_QUIET_TEST 3625 If this option is defined, the common CFI flash doesn't 3626 print it's warning upon not recognized FLASH banks. This 3627 is useful, if some of the configured banks are only 3628 optionally available. 3629 3630- CONFIG_FLASH_SHOW_PROGRESS 3631 If defined (must be an integer), print out countdown 3632 digits and dots. Recommended value: 45 (9..1) for 80 3633 column displays, 15 (3..1) for 40 column displays. 3634 3635- CONFIG_FLASH_VERIFY 3636 If defined, the content of the flash (destination) is compared 3637 against the source after the write operation. An error message 3638 will be printed when the contents are not identical. 3639 Please note that this option is useless in nearly all cases, 3640 since such flash programming errors usually are detected earlier 3641 while unprotecting/erasing/programming. Please only enable 3642 this option if you really know what you are doing. 3643 3644- CONFIG_SYS_RX_ETH_BUFFER: 3645 Defines the number of Ethernet receive buffers. On some 3646 Ethernet controllers it is recommended to set this value 3647 to 8 or even higher (EEPRO100 or 405 EMAC), since all 3648 buffers can be full shortly after enabling the interface 3649 on high Ethernet traffic. 3650 Defaults to 4 if not defined. 3651 3652- CONFIG_ENV_MAX_ENTRIES 3653 3654 Maximum number of entries in the hash table that is used 3655 internally to store the environment settings. The default 3656 setting is supposed to be generous and should work in most 3657 cases. This setting can be used to tune behaviour; see 3658 lib/hashtable.c for details. 3659 3660- CONFIG_ENV_FLAGS_LIST_DEFAULT 3661- CONFIG_ENV_FLAGS_LIST_STATIC 3662 Enable validation of the values given to environment variables when 3663 calling env set. Variables can be restricted to only decimal, 3664 hexadecimal, or boolean. If CONFIG_CMD_NET is also defined, 3665 the variables can also be restricted to IP address or MAC address. 3666 3667 The format of the list is: 3668 type_attribute = [s|d|x|b|i|m] 3669 access_attribute = [a|r|o|c] 3670 attributes = type_attribute[access_attribute] 3671 entry = variable_name[:attributes] 3672 list = entry[,list] 3673 3674 The type attributes are: 3675 s - String (default) 3676 d - Decimal 3677 x - Hexadecimal 3678 b - Boolean ([1yYtT|0nNfF]) 3679 i - IP address 3680 m - MAC address 3681 3682 The access attributes are: 3683 a - Any (default) 3684 r - Read-only 3685 o - Write-once 3686 c - Change-default 3687 3688 - CONFIG_ENV_FLAGS_LIST_DEFAULT 3689 Define this to a list (string) to define the ".flags" 3690 environment variable in the default or embedded environment. 3691 3692 - CONFIG_ENV_FLAGS_LIST_STATIC 3693 Define this to a list (string) to define validation that 3694 should be done if an entry is not found in the ".flags" 3695 environment variable. To override a setting in the static 3696 list, simply add an entry for the same variable name to the 3697 ".flags" variable. 3698 3699 If CONFIG_REGEX is defined, the variable_name above is evaluated as a 3700 regular expression. This allows multiple variables to define the same 3701 flags without explicitly listing them for each variable. 3702 3703- CONFIG_ENV_ACCESS_IGNORE_FORCE 3704 If defined, don't allow the -f switch to env set override variable 3705 access flags. 3706 3707- CONFIG_OMAP_PLATFORM_RESET_TIME_MAX_USEC (OMAP only) 3708 This is set by OMAP boards for the max time that reset should 3709 be asserted. See doc/README.omap-reset-time for details on how 3710 the value can be calculated on a given board. 3711 3712- CONFIG_USE_STDINT 3713 If stdint.h is available with your toolchain you can define this 3714 option to enable it. You can provide option 'USE_STDINT=1' when 3715 building U-Boot to enable this. 3716 3717The following definitions that deal with the placement and management 3718of environment data (variable area); in general, we support the 3719following configurations: 3720 3721- CONFIG_BUILD_ENVCRC: 3722 3723 Builds up envcrc with the target environment so that external utils 3724 may easily extract it and embed it in final U-Boot images. 3725 3726- CONFIG_ENV_IS_IN_FLASH: 3727 3728 Define this if the environment is in flash memory. 3729 3730 a) The environment occupies one whole flash sector, which is 3731 "embedded" in the text segment with the U-Boot code. This 3732 happens usually with "bottom boot sector" or "top boot 3733 sector" type flash chips, which have several smaller 3734 sectors at the start or the end. For instance, such a 3735 layout can have sector sizes of 8, 2x4, 16, Nx32 kB. In 3736 such a case you would place the environment in one of the 3737 4 kB sectors - with U-Boot code before and after it. With 3738 "top boot sector" type flash chips, you would put the 3739 environment in one of the last sectors, leaving a gap 3740 between U-Boot and the environment. 3741 3742 - CONFIG_ENV_OFFSET: 3743 3744 Offset of environment data (variable area) to the 3745 beginning of flash memory; for instance, with bottom boot 3746 type flash chips the second sector can be used: the offset 3747 for this sector is given here. 3748 3749 CONFIG_ENV_OFFSET is used relative to CONFIG_SYS_FLASH_BASE. 3750 3751 - CONFIG_ENV_ADDR: 3752 3753 This is just another way to specify the start address of 3754 the flash sector containing the environment (instead of 3755 CONFIG_ENV_OFFSET). 3756 3757 - CONFIG_ENV_SECT_SIZE: 3758 3759 Size of the sector containing the environment. 3760 3761 3762 b) Sometimes flash chips have few, equal sized, BIG sectors. 3763 In such a case you don't want to spend a whole sector for 3764 the environment. 3765 3766 - CONFIG_ENV_SIZE: 3767 3768 If you use this in combination with CONFIG_ENV_IS_IN_FLASH 3769 and CONFIG_ENV_SECT_SIZE, you can specify to use only a part 3770 of this flash sector for the environment. This saves 3771 memory for the RAM copy of the environment. 3772 3773 It may also save flash memory if you decide to use this 3774 when your environment is "embedded" within U-Boot code, 3775 since then the remainder of the flash sector could be used 3776 for U-Boot code. It should be pointed out that this is 3777 STRONGLY DISCOURAGED from a robustness point of view: 3778 updating the environment in flash makes it always 3779 necessary to erase the WHOLE sector. If something goes 3780 wrong before the contents has been restored from a copy in 3781 RAM, your target system will be dead. 3782 3783 - CONFIG_ENV_ADDR_REDUND 3784 CONFIG_ENV_SIZE_REDUND 3785 3786 These settings describe a second storage area used to hold 3787 a redundant copy of the environment data, so that there is 3788 a valid backup copy in case there is a power failure during 3789 a "saveenv" operation. 3790 3791BE CAREFUL! Any changes to the flash layout, and some changes to the 3792source code will make it necessary to adapt <board>/u-boot.lds* 3793accordingly! 3794 3795 3796- CONFIG_ENV_IS_IN_NVRAM: 3797 3798 Define this if you have some non-volatile memory device 3799 (NVRAM, battery buffered SRAM) which you want to use for the 3800 environment. 3801 3802 - CONFIG_ENV_ADDR: 3803 - CONFIG_ENV_SIZE: 3804 3805 These two #defines are used to determine the memory area you 3806 want to use for environment. It is assumed that this memory 3807 can just be read and written to, without any special 3808 provision. 3809 3810BE CAREFUL! The first access to the environment happens quite early 3811in U-Boot initialization (when we try to get the setting of for the 3812console baudrate). You *MUST* have mapped your NVRAM area then, or 3813U-Boot will hang. 3814 3815Please note that even with NVRAM we still use a copy of the 3816environment in RAM: we could work on NVRAM directly, but we want to 3817keep settings there always unmodified except somebody uses "saveenv" 3818to save the current settings. 3819 3820 3821- CONFIG_ENV_IS_IN_EEPROM: 3822 3823 Use this if you have an EEPROM or similar serial access 3824 device and a driver for it. 3825 3826 - CONFIG_ENV_OFFSET: 3827 - CONFIG_ENV_SIZE: 3828 3829 These two #defines specify the offset and size of the 3830 environment area within the total memory of your EEPROM. 3831 3832 - CONFIG_SYS_I2C_EEPROM_ADDR: 3833 If defined, specified the chip address of the EEPROM device. 3834 The default address is zero. 3835 3836 - CONFIG_SYS_I2C_EEPROM_BUS: 3837 If defined, specified the i2c bus of the EEPROM device. 3838 3839 - CONFIG_SYS_EEPROM_PAGE_WRITE_BITS: 3840 If defined, the number of bits used to address bytes in a 3841 single page in the EEPROM device. A 64 byte page, for example 3842 would require six bits. 3843 3844 - CONFIG_SYS_EEPROM_PAGE_WRITE_DELAY_MS: 3845 If defined, the number of milliseconds to delay between 3846 page writes. The default is zero milliseconds. 3847 3848 - CONFIG_SYS_I2C_EEPROM_ADDR_LEN: 3849 The length in bytes of the EEPROM memory array address. Note 3850 that this is NOT the chip address length! 3851 3852 - CONFIG_SYS_I2C_EEPROM_ADDR_OVERFLOW: 3853 EEPROM chips that implement "address overflow" are ones 3854 like Catalyst 24WC04/08/16 which has 9/10/11 bits of 3855 address and the extra bits end up in the "chip address" bit 3856 slots. This makes a 24WC08 (1Kbyte) chip look like four 256 3857 byte chips. 3858 3859 Note that we consider the length of the address field to 3860 still be one byte because the extra address bits are hidden 3861 in the chip address. 3862 3863 - CONFIG_SYS_EEPROM_SIZE: 3864 The size in bytes of the EEPROM device. 3865 3866 - CONFIG_ENV_EEPROM_IS_ON_I2C 3867 define this, if you have I2C and SPI activated, and your 3868 EEPROM, which holds the environment, is on the I2C bus. 3869 3870 - CONFIG_I2C_ENV_EEPROM_BUS 3871 if you have an Environment on an EEPROM reached over 3872 I2C muxes, you can define here, how to reach this 3873 EEPROM. For example: 3874 3875 #define CONFIG_I2C_ENV_EEPROM_BUS 1 3876 3877 EEPROM which holds the environment, is reached over 3878 a pca9547 i2c mux with address 0x70, channel 3. 3879 3880- CONFIG_ENV_IS_IN_DATAFLASH: 3881 3882 Define this if you have a DataFlash memory device which you 3883 want to use for the environment. 3884 3885 - CONFIG_ENV_OFFSET: 3886 - CONFIG_ENV_ADDR: 3887 - CONFIG_ENV_SIZE: 3888 3889 These three #defines specify the offset and size of the 3890 environment area within the total memory of your DataFlash placed 3891 at the specified address. 3892 3893- CONFIG_ENV_IS_IN_SPI_FLASH: 3894 3895 Define this if you have a SPI Flash memory device which you 3896 want to use for the environment. 3897 3898 - CONFIG_ENV_OFFSET: 3899 - CONFIG_ENV_SIZE: 3900 3901 These two #defines specify the offset and size of the 3902 environment area within the SPI Flash. CONFIG_ENV_OFFSET must be 3903 aligned to an erase sector boundary. 3904 3905 - CONFIG_ENV_SECT_SIZE: 3906 3907 Define the SPI flash's sector size. 3908 3909 - CONFIG_ENV_OFFSET_REDUND (optional): 3910 3911 This setting describes a second storage area of CONFIG_ENV_SIZE 3912 size used to hold a redundant copy of the environment data, so 3913 that there is a valid backup copy in case there is a power failure 3914 during a "saveenv" operation. CONFIG_ENV_OFFSET_REDUND must be 3915 aligned to an erase sector boundary. 3916 3917 - CONFIG_ENV_SPI_BUS (optional): 3918 - CONFIG_ENV_SPI_CS (optional): 3919 3920 Define the SPI bus and chip select. If not defined they will be 0. 3921 3922 - CONFIG_ENV_SPI_MAX_HZ (optional): 3923 3924 Define the SPI max work clock. If not defined then use 1MHz. 3925 3926 - CONFIG_ENV_SPI_MODE (optional): 3927 3928 Define the SPI work mode. If not defined then use SPI_MODE_3. 3929 3930- CONFIG_ENV_IS_IN_REMOTE: 3931 3932 Define this if you have a remote memory space which you 3933 want to use for the local device's environment. 3934 3935 - CONFIG_ENV_ADDR: 3936 - CONFIG_ENV_SIZE: 3937 3938 These two #defines specify the address and size of the 3939 environment area within the remote memory space. The 3940 local device can get the environment from remote memory 3941 space by SRIO or PCIE links. 3942 3943BE CAREFUL! For some special cases, the local device can not use 3944"saveenv" command. For example, the local device will get the 3945environment stored in a remote NOR flash by SRIO or PCIE link, 3946but it can not erase, write this NOR flash by SRIO or PCIE interface. 3947 3948- CONFIG_ENV_IS_IN_NAND: 3949 3950 Define this if you have a NAND device which you want to use 3951 for the environment. 3952 3953 - CONFIG_ENV_OFFSET: 3954 - CONFIG_ENV_SIZE: 3955 3956 These two #defines specify the offset and size of the environment 3957 area within the first NAND device. CONFIG_ENV_OFFSET must be 3958 aligned to an erase block boundary. 3959 3960 - CONFIG_ENV_OFFSET_REDUND (optional): 3961 3962 This setting describes a second storage area of CONFIG_ENV_SIZE 3963 size used to hold a redundant copy of the environment data, so 3964 that there is a valid backup copy in case there is a power failure 3965 during a "saveenv" operation. CONFIG_ENV_OFFSET_REDUND must be 3966 aligned to an erase block boundary. 3967 3968 - CONFIG_ENV_RANGE (optional): 3969 3970 Specifies the length of the region in which the environment 3971 can be written. This should be a multiple of the NAND device's 3972 block size. Specifying a range with more erase blocks than 3973 are needed to hold CONFIG_ENV_SIZE allows bad blocks within 3974 the range to be avoided. 3975 3976 - CONFIG_ENV_OFFSET_OOB (optional): 3977 3978 Enables support for dynamically retrieving the offset of the 3979 environment from block zero's out-of-band data. The 3980 "nand env.oob" command can be used to record this offset. 3981 Currently, CONFIG_ENV_OFFSET_REDUND is not supported when 3982 using CONFIG_ENV_OFFSET_OOB. 3983 3984- CONFIG_NAND_ENV_DST 3985 3986 Defines address in RAM to which the nand_spl code should copy the 3987 environment. If redundant environment is used, it will be copied to 3988 CONFIG_NAND_ENV_DST + CONFIG_ENV_SIZE. 3989 3990- CONFIG_ENV_IS_IN_UBI: 3991 3992 Define this if you have an UBI volume that you want to use for the 3993 environment. This has the benefit of wear-leveling the environment 3994 accesses, which is important on NAND. 3995 3996 - CONFIG_ENV_UBI_PART: 3997 3998 Define this to a string that is the mtd partition containing the UBI. 3999 4000 - CONFIG_ENV_UBI_VOLUME: 4001 4002 Define this to the name of the volume that you want to store the 4003 environment in. 4004 4005 - CONFIG_ENV_UBI_VOLUME_REDUND: 4006 4007 Define this to the name of another volume to store a second copy of 4008 the environment in. This will enable redundant environments in UBI. 4009 It is assumed that both volumes are in the same MTD partition. 4010 4011 - CONFIG_UBI_SILENCE_MSG 4012 - CONFIG_UBIFS_SILENCE_MSG 4013 4014 You will probably want to define these to avoid a really noisy system 4015 when storing the env in UBI. 4016 4017- CONFIG_ENV_IS_IN_FAT: 4018 Define this if you want to use the FAT file system for the environment. 4019 4020 - FAT_ENV_INTERFACE: 4021 4022 Define this to a string that is the name of the block device. 4023 4024 - FAT_ENV_DEVICE_AND_PART: 4025 4026 Define this to a string to specify the partition of the device. It can 4027 be as following: 4028 4029 "D:P", "D:0", "D", "D:" or "D:auto" (D, P are integers. And P >= 1) 4030 - "D:P": device D partition P. Error occurs if device D has no 4031 partition table. 4032 - "D:0": device D. 4033 - "D" or "D:": device D partition 1 if device D has partition 4034 table, or the whole device D if has no partition 4035 table. 4036 - "D:auto": first partition in device D with bootable flag set. 4037 If none, first valid partition in device D. If no 4038 partition table then means device D. 4039 4040 - FAT_ENV_FILE: 4041 4042 It's a string of the FAT file name. This file use to store the 4043 environment. 4044 4045 - CONFIG_FAT_WRITE: 4046 This should be defined. Otherwise it cannot save the environment file. 4047 4048- CONFIG_ENV_IS_IN_MMC: 4049 4050 Define this if you have an MMC device which you want to use for the 4051 environment. 4052 4053 - CONFIG_SYS_MMC_ENV_DEV: 4054 4055 Specifies which MMC device the environment is stored in. 4056 4057 - CONFIG_SYS_MMC_ENV_PART (optional): 4058 4059 Specifies which MMC partition the environment is stored in. If not 4060 set, defaults to partition 0, the user area. Common values might be 4061 1 (first MMC boot partition), 2 (second MMC boot partition). 4062 4063 - CONFIG_ENV_OFFSET: 4064 - CONFIG_ENV_SIZE: 4065 4066 These two #defines specify the offset and size of the environment 4067 area within the specified MMC device. 4068 4069 If offset is positive (the usual case), it is treated as relative to 4070 the start of the MMC partition. If offset is negative, it is treated 4071 as relative to the end of the MMC partition. This can be useful if 4072 your board may be fitted with different MMC devices, which have 4073 different sizes for the MMC partitions, and you always want the 4074 environment placed at the very end of the partition, to leave the 4075 maximum possible space before it, to store other data. 4076 4077 These two values are in units of bytes, but must be aligned to an 4078 MMC sector boundary. 4079 4080 - CONFIG_ENV_OFFSET_REDUND (optional): 4081 4082 Specifies a second storage area, of CONFIG_ENV_SIZE size, used to 4083 hold a redundant copy of the environment data. This provides a 4084 valid backup copy in case the other copy is corrupted, e.g. due 4085 to a power failure during a "saveenv" operation. 4086 4087 This value may also be positive or negative; this is handled in the 4088 same way as CONFIG_ENV_OFFSET. 4089 4090 This value is also in units of bytes, but must also be aligned to 4091 an MMC sector boundary. 4092 4093 - CONFIG_ENV_SIZE_REDUND (optional): 4094 4095 This value need not be set, even when CONFIG_ENV_OFFSET_REDUND is 4096 set. If this value is set, it must be set to the same value as 4097 CONFIG_ENV_SIZE. 4098 4099- CONFIG_SYS_SPI_INIT_OFFSET 4100 4101 Defines offset to the initial SPI buffer area in DPRAM. The 4102 area is used at an early stage (ROM part) if the environment 4103 is configured to reside in the SPI EEPROM: We need a 520 byte 4104 scratch DPRAM area. It is used between the two initialization 4105 calls (spi_init_f() and spi_init_r()). A value of 0xB00 seems 4106 to be a good choice since it makes it far enough from the 4107 start of the data area as well as from the stack pointer. 4108 4109Please note that the environment is read-only until the monitor 4110has been relocated to RAM and a RAM copy of the environment has been 4111created; also, when using EEPROM you will have to use getenv_f() 4112until then to read environment variables. 4113 4114The environment is protected by a CRC32 checksum. Before the monitor 4115is relocated into RAM, as a result of a bad CRC you will be working 4116with the compiled-in default environment - *silently*!!! [This is 4117necessary, because the first environment variable we need is the 4118"baudrate" setting for the console - if we have a bad CRC, we don't 4119have any device yet where we could complain.] 4120 4121Note: once the monitor has been relocated, then it will complain if 4122the default environment is used; a new CRC is computed as soon as you 4123use the "saveenv" command to store a valid environment. 4124 4125- CONFIG_SYS_FAULT_ECHO_LINK_DOWN: 4126 Echo the inverted Ethernet link state to the fault LED. 4127 4128 Note: If this option is active, then CONFIG_SYS_FAULT_MII_ADDR 4129 also needs to be defined. 4130 4131- CONFIG_SYS_FAULT_MII_ADDR: 4132 MII address of the PHY to check for the Ethernet link state. 4133 4134- CONFIG_NS16550_MIN_FUNCTIONS: 4135 Define this if you desire to only have use of the NS16550_init 4136 and NS16550_putc functions for the serial driver located at 4137 drivers/serial/ns16550.c. This option is useful for saving 4138 space for already greatly restricted images, including but not 4139 limited to NAND_SPL configurations. 4140 4141- CONFIG_DISPLAY_BOARDINFO 4142 Display information about the board that U-Boot is running on 4143 when U-Boot starts up. The board function checkboard() is called 4144 to do this. 4145 4146- CONFIG_DISPLAY_BOARDINFO_LATE 4147 Similar to the previous option, but display this information 4148 later, once stdio is running and output goes to the LCD, if 4149 present. 4150 4151- CONFIG_BOARD_SIZE_LIMIT: 4152 Maximum size of the U-Boot image. When defined, the 4153 build system checks that the actual size does not 4154 exceed it. 4155 4156Low Level (hardware related) configuration options: 4157--------------------------------------------------- 4158 4159- CONFIG_SYS_CACHELINE_SIZE: 4160 Cache Line Size of the CPU. 4161 4162- CONFIG_SYS_DEFAULT_IMMR: 4163 Default address of the IMMR after system reset. 4164 4165 Needed on some 8260 systems (MPC8260ADS, PQ2FADS-ZU, 4166 and RPXsuper) to be able to adjust the position of 4167 the IMMR register after a reset. 4168 4169- CONFIG_SYS_CCSRBAR_DEFAULT: 4170 Default (power-on reset) physical address of CCSR on Freescale 4171 PowerPC SOCs. 4172 4173- CONFIG_SYS_CCSRBAR: 4174 Virtual address of CCSR. On a 32-bit build, this is typically 4175 the same value as CONFIG_SYS_CCSRBAR_DEFAULT. 4176 4177 CONFIG_SYS_DEFAULT_IMMR must also be set to this value, 4178 for cross-platform code that uses that macro instead. 4179 4180- CONFIG_SYS_CCSRBAR_PHYS: 4181 Physical address of CCSR. CCSR can be relocated to a new 4182 physical address, if desired. In this case, this macro should 4183 be set to that address. Otherwise, it should be set to the 4184 same value as CONFIG_SYS_CCSRBAR_DEFAULT. For example, CCSR 4185 is typically relocated on 36-bit builds. It is recommended 4186 that this macro be defined via the _HIGH and _LOW macros: 4187 4188 #define CONFIG_SYS_CCSRBAR_PHYS ((CONFIG_SYS_CCSRBAR_PHYS_HIGH 4189 * 1ull) << 32 | CONFIG_SYS_CCSRBAR_PHYS_LOW) 4190 4191- CONFIG_SYS_CCSRBAR_PHYS_HIGH: 4192 Bits 33-36 of CONFIG_SYS_CCSRBAR_PHYS. This value is typically 4193 either 0 (32-bit build) or 0xF (36-bit build). This macro is 4194 used in assembly code, so it must not contain typecasts or 4195 integer size suffixes (e.g. "ULL"). 4196 4197- CONFIG_SYS_CCSRBAR_PHYS_LOW: 4198 Lower 32-bits of CONFIG_SYS_CCSRBAR_PHYS. This macro is 4199 used in assembly code, so it must not contain typecasts or 4200 integer size suffixes (e.g. "ULL"). 4201 4202- CONFIG_SYS_CCSR_DO_NOT_RELOCATE: 4203 If this macro is defined, then CONFIG_SYS_CCSRBAR_PHYS will be 4204 forced to a value that ensures that CCSR is not relocated. 4205 4206- Floppy Disk Support: 4207 CONFIG_SYS_FDC_DRIVE_NUMBER 4208 4209 the default drive number (default value 0) 4210 4211 CONFIG_SYS_ISA_IO_STRIDE 4212 4213 defines the spacing between FDC chipset registers 4214 (default value 1) 4215 4216 CONFIG_SYS_ISA_IO_OFFSET 4217 4218 defines the offset of register from address. It 4219 depends on which part of the data bus is connected to 4220 the FDC chipset. (default value 0) 4221 4222 If CONFIG_SYS_ISA_IO_STRIDE CONFIG_SYS_ISA_IO_OFFSET and 4223 CONFIG_SYS_FDC_DRIVE_NUMBER are undefined, they take their 4224 default value. 4225 4226 if CONFIG_SYS_FDC_HW_INIT is defined, then the function 4227 fdc_hw_init() is called at the beginning of the FDC 4228 setup. fdc_hw_init() must be provided by the board 4229 source code. It is used to make hardware-dependent 4230 initializations. 4231 4232- CONFIG_IDE_AHB: 4233 Most IDE controllers were designed to be connected with PCI 4234 interface. Only few of them were designed for AHB interface. 4235 When software is doing ATA command and data transfer to 4236 IDE devices through IDE-AHB controller, some additional 4237 registers accessing to these kind of IDE-AHB controller 4238 is required. 4239 4240- CONFIG_SYS_IMMR: Physical address of the Internal Memory. 4241 DO NOT CHANGE unless you know exactly what you're 4242 doing! (11-4) [MPC8xx/82xx systems only] 4243 4244- CONFIG_SYS_INIT_RAM_ADDR: 4245 4246 Start address of memory area that can be used for 4247 initial data and stack; please note that this must be 4248 writable memory that is working WITHOUT special 4249 initialization, i. e. you CANNOT use normal RAM which 4250 will become available only after programming the 4251 memory controller and running certain initialization 4252 sequences. 4253 4254 U-Boot uses the following memory types: 4255 - MPC8xx and MPC8260: IMMR (internal memory of the CPU) 4256 - MPC824X: data cache 4257 - PPC4xx: data cache 4258 4259- CONFIG_SYS_GBL_DATA_OFFSET: 4260 4261 Offset of the initial data structure in the memory 4262 area defined by CONFIG_SYS_INIT_RAM_ADDR. Usually 4263 CONFIG_SYS_GBL_DATA_OFFSET is chosen such that the initial 4264 data is located at the end of the available space 4265 (sometimes written as (CONFIG_SYS_INIT_RAM_SIZE - 4266 GENERATED_GBL_DATA_SIZE), and the initial stack is just 4267 below that area (growing from (CONFIG_SYS_INIT_RAM_ADDR + 4268 CONFIG_SYS_GBL_DATA_OFFSET) downward. 4269 4270 Note: 4271 On the MPC824X (or other systems that use the data 4272 cache for initial memory) the address chosen for 4273 CONFIG_SYS_INIT_RAM_ADDR is basically arbitrary - it must 4274 point to an otherwise UNUSED address space between 4275 the top of RAM and the start of the PCI space. 4276 4277- CONFIG_SYS_SIUMCR: SIU Module Configuration (11-6) 4278 4279- CONFIG_SYS_SYPCR: System Protection Control (11-9) 4280 4281- CONFIG_SYS_TBSCR: Time Base Status and Control (11-26) 4282 4283- CONFIG_SYS_PISCR: Periodic Interrupt Status and Control (11-31) 4284 4285- CONFIG_SYS_PLPRCR: PLL, Low-Power, and Reset Control Register (15-30) 4286 4287- CONFIG_SYS_SCCR: System Clock and reset Control Register (15-27) 4288 4289- CONFIG_SYS_OR_TIMING_SDRAM: 4290 SDRAM timing 4291 4292- CONFIG_SYS_MAMR_PTA: 4293 periodic timer for refresh 4294 4295- CONFIG_SYS_DER: Debug Event Register (37-47) 4296 4297- FLASH_BASE0_PRELIM, FLASH_BASE1_PRELIM, CONFIG_SYS_REMAP_OR_AM, 4298 CONFIG_SYS_PRELIM_OR_AM, CONFIG_SYS_OR_TIMING_FLASH, CONFIG_SYS_OR0_REMAP, 4299 CONFIG_SYS_OR0_PRELIM, CONFIG_SYS_BR0_PRELIM, CONFIG_SYS_OR1_REMAP, CONFIG_SYS_OR1_PRELIM, 4300 CONFIG_SYS_BR1_PRELIM: 4301 Memory Controller Definitions: BR0/1 and OR0/1 (FLASH) 4302 4303- SDRAM_BASE2_PRELIM, SDRAM_BASE3_PRELIM, SDRAM_MAX_SIZE, 4304 CONFIG_SYS_OR_TIMING_SDRAM, CONFIG_SYS_OR2_PRELIM, CONFIG_SYS_BR2_PRELIM, 4305 CONFIG_SYS_OR3_PRELIM, CONFIG_SYS_BR3_PRELIM: 4306 Memory Controller Definitions: BR2/3 and OR2/3 (SDRAM) 4307 4308- CONFIG_SYS_MAMR_PTA, CONFIG_SYS_MPTPR_2BK_4K, CONFIG_SYS_MPTPR_1BK_4K, CONFIG_SYS_MPTPR_2BK_8K, 4309 CONFIG_SYS_MPTPR_1BK_8K, CONFIG_SYS_MAMR_8COL, CONFIG_SYS_MAMR_9COL: 4310 Machine Mode Register and Memory Periodic Timer 4311 Prescaler definitions (SDRAM timing) 4312 4313- CONFIG_SYS_I2C_UCODE_PATCH, CONFIG_SYS_I2C_DPMEM_OFFSET [0x1FC0]: 4314 enable I2C microcode relocation patch (MPC8xx); 4315 define relocation offset in DPRAM [DSP2] 4316 4317- CONFIG_SYS_SMC_UCODE_PATCH, CONFIG_SYS_SMC_DPMEM_OFFSET [0x1FC0]: 4318 enable SMC microcode relocation patch (MPC8xx); 4319 define relocation offset in DPRAM [SMC1] 4320 4321- CONFIG_SYS_SPI_UCODE_PATCH, CONFIG_SYS_SPI_DPMEM_OFFSET [0x1FC0]: 4322 enable SPI microcode relocation patch (MPC8xx); 4323 define relocation offset in DPRAM [SCC4] 4324 4325- CONFIG_SYS_CPM_POST_WORD_ADDR: (MPC8xx, MPC8260 only) 4326 Offset of the bootmode word in DPRAM used by post 4327 (Power On Self Tests). This definition overrides 4328 #define'd default value in commproc.h resp. 4329 cpm_8260.h. 4330 4331- CONFIG_SYS_PCI_SLV_MEM_LOCAL, CONFIG_SYS_PCI_SLV_MEM_BUS, CONFIG_SYS_PICMR0_MASK_ATTRIB, 4332 CONFIG_SYS_PCI_MSTR0_LOCAL, CONFIG_SYS_PCIMSK0_MASK, CONFIG_SYS_PCI_MSTR1_LOCAL, 4333 CONFIG_SYS_PCIMSK1_MASK, CONFIG_SYS_PCI_MSTR_MEM_LOCAL, CONFIG_SYS_PCI_MSTR_MEM_BUS, 4334 CONFIG_SYS_CPU_PCI_MEM_START, CONFIG_SYS_PCI_MSTR_MEM_SIZE, CONFIG_SYS_POCMR0_MASK_ATTRIB, 4335 CONFIG_SYS_PCI_MSTR_MEMIO_LOCAL, CONFIG_SYS_PCI_MSTR_MEMIO_BUS, CPU_PCI_MEMIO_START, 4336 CONFIG_SYS_PCI_MSTR_MEMIO_SIZE, CONFIG_SYS_POCMR1_MASK_ATTRIB, CONFIG_SYS_PCI_MSTR_IO_LOCAL, 4337 CONFIG_SYS_PCI_MSTR_IO_BUS, CONFIG_SYS_CPU_PCI_IO_START, CONFIG_SYS_PCI_MSTR_IO_SIZE, 4338 CONFIG_SYS_POCMR2_MASK_ATTRIB: (MPC826x only) 4339 Overrides the default PCI memory map in arch/powerpc/cpu/mpc8260/pci.c if set. 4340 4341- CONFIG_PCI_DISABLE_PCIE: 4342 Disable PCI-Express on systems where it is supported but not 4343 required. 4344 4345- CONFIG_PCI_ENUM_ONLY 4346 Only scan through and get the devices on the buses. 4347 Don't do any setup work, presumably because someone or 4348 something has already done it, and we don't need to do it 4349 a second time. Useful for platforms that are pre-booted 4350 by coreboot or similar. 4351 4352- CONFIG_PCI_INDIRECT_BRIDGE: 4353 Enable support for indirect PCI bridges. 4354 4355- CONFIG_SYS_SRIO: 4356 Chip has SRIO or not 4357 4358- CONFIG_SRIO1: 4359 Board has SRIO 1 port available 4360 4361- CONFIG_SRIO2: 4362 Board has SRIO 2 port available 4363 4364- CONFIG_SRIO_PCIE_BOOT_MASTER 4365 Board can support master function for Boot from SRIO and PCIE 4366 4367- CONFIG_SYS_SRIOn_MEM_VIRT: 4368 Virtual Address of SRIO port 'n' memory region 4369 4370- CONFIG_SYS_SRIOn_MEM_PHYS: 4371 Physical Address of SRIO port 'n' memory region 4372 4373- CONFIG_SYS_SRIOn_MEM_SIZE: 4374 Size of SRIO port 'n' memory region 4375 4376- CONFIG_SYS_NAND_BUSWIDTH_16BIT 4377 Defined to tell the NAND controller that the NAND chip is using 4378 a 16 bit bus. 4379 Not all NAND drivers use this symbol. 4380 Example of drivers that use it: 4381 - drivers/mtd/nand/ndfc.c 4382 - drivers/mtd/nand/mxc_nand.c 4383 4384- CONFIG_SYS_NDFC_EBC0_CFG 4385 Sets the EBC0_CFG register for the NDFC. If not defined 4386 a default value will be used. 4387 4388- CONFIG_SPD_EEPROM 4389 Get DDR timing information from an I2C EEPROM. Common 4390 with pluggable memory modules such as SODIMMs 4391 4392 SPD_EEPROM_ADDRESS 4393 I2C address of the SPD EEPROM 4394 4395- CONFIG_SYS_SPD_BUS_NUM 4396 If SPD EEPROM is on an I2C bus other than the first 4397 one, specify here. Note that the value must resolve 4398 to something your driver can deal with. 4399 4400- CONFIG_SYS_DDR_RAW_TIMING 4401 Get DDR timing information from other than SPD. Common with 4402 soldered DDR chips onboard without SPD. DDR raw timing 4403 parameters are extracted from datasheet and hard-coded into 4404 header files or board specific files. 4405 4406- CONFIG_FSL_DDR_INTERACTIVE 4407 Enable interactive DDR debugging. See doc/README.fsl-ddr. 4408 4409- CONFIG_FSL_DDR_SYNC_REFRESH 4410 Enable sync of refresh for multiple controllers. 4411 4412- CONFIG_FSL_DDR_BIST 4413 Enable built-in memory test for Freescale DDR controllers. 4414 4415- CONFIG_SYS_83XX_DDR_USES_CS0 4416 Only for 83xx systems. If specified, then DDR should 4417 be configured using CS0 and CS1 instead of CS2 and CS3. 4418 4419- CONFIG_ETHER_ON_FEC[12] 4420 Define to enable FEC[12] on a 8xx series processor. 4421 4422- CONFIG_FEC[12]_PHY 4423 Define to the hardcoded PHY address which corresponds 4424 to the given FEC; i. e. 4425 #define CONFIG_FEC1_PHY 4 4426 means that the PHY with address 4 is connected to FEC1 4427 4428 When set to -1, means to probe for first available. 4429 4430- CONFIG_FEC[12]_PHY_NORXERR 4431 The PHY does not have a RXERR line (RMII only). 4432 (so program the FEC to ignore it). 4433 4434- CONFIG_RMII 4435 Enable RMII mode for all FECs. 4436 Note that this is a global option, we can't 4437 have one FEC in standard MII mode and another in RMII mode. 4438 4439- CONFIG_CRC32_VERIFY 4440 Add a verify option to the crc32 command. 4441 The syntax is: 4442 4443 => crc32 -v <address> <count> <crc32> 4444 4445 Where address/count indicate a memory area 4446 and crc32 is the correct crc32 which the 4447 area should have. 4448 4449- CONFIG_LOOPW 4450 Add the "loopw" memory command. This only takes effect if 4451 the memory commands are activated globally (CONFIG_CMD_MEM). 4452 4453- CONFIG_MX_CYCLIC 4454 Add the "mdc" and "mwc" memory commands. These are cyclic 4455 "md/mw" commands. 4456 Examples: 4457 4458 => mdc.b 10 4 500 4459 This command will print 4 bytes (10,11,12,13) each 500 ms. 4460 4461 => mwc.l 100 12345678 10 4462 This command will write 12345678 to address 100 all 10 ms. 4463 4464 This only takes effect if the memory commands are activated 4465 globally (CONFIG_CMD_MEM). 4466 4467- CONFIG_SKIP_LOWLEVEL_INIT 4468 [ARM, NDS32, MIPS only] If this variable is defined, then certain 4469 low level initializations (like setting up the memory 4470 controller) are omitted and/or U-Boot does not 4471 relocate itself into RAM. 4472 4473 Normally this variable MUST NOT be defined. The only 4474 exception is when U-Boot is loaded (to RAM) by some 4475 other boot loader or by a debugger which performs 4476 these initializations itself. 4477 4478- CONFIG_SKIP_LOWLEVEL_INIT_ONLY 4479 [ARM926EJ-S only] This allows just the call to lowlevel_init() 4480 to be skipped. The normal CP15 init (such as enabling the 4481 instruction cache) is still performed. 4482 4483- CONFIG_SPL_BUILD 4484 Modifies the behaviour of start.S when compiling a loader 4485 that is executed before the actual U-Boot. E.g. when 4486 compiling a NAND SPL. 4487 4488- CONFIG_TPL_BUILD 4489 Modifies the behaviour of start.S when compiling a loader 4490 that is executed after the SPL and before the actual U-Boot. 4491 It is loaded by the SPL. 4492 4493- CONFIG_SYS_MPC85XX_NO_RESETVEC 4494 Only for 85xx systems. If this variable is specified, the section 4495 .resetvec is not kept and the section .bootpg is placed in the 4496 previous 4k of the .text section. 4497 4498- CONFIG_ARCH_MAP_SYSMEM 4499 Generally U-Boot (and in particular the md command) uses 4500 effective address. It is therefore not necessary to regard 4501 U-Boot address as virtual addresses that need to be translated 4502 to physical addresses. However, sandbox requires this, since 4503 it maintains its own little RAM buffer which contains all 4504 addressable memory. This option causes some memory accesses 4505 to be mapped through map_sysmem() / unmap_sysmem(). 4506 4507- CONFIG_X86_RESET_VECTOR 4508 If defined, the x86 reset vector code is included. This is not 4509 needed when U-Boot is running from Coreboot. 4510 4511- CONFIG_SYS_MPUCLK 4512 Defines the MPU clock speed (in MHz). 4513 4514 NOTE : currently only supported on AM335x platforms. 4515 4516- CONFIG_SPL_AM33XX_ENABLE_RTC32K_OSC: 4517 Enables the RTC32K OSC on AM33xx based plattforms 4518 4519- CONFIG_SYS_NAND_NO_SUBPAGE_WRITE 4520 Option to disable subpage write in NAND driver 4521 driver that uses this: 4522 drivers/mtd/nand/davinci_nand.c 4523 4524Freescale QE/FMAN Firmware Support: 4525----------------------------------- 4526 4527The Freescale QUICCEngine (QE) and Frame Manager (FMAN) both support the 4528loading of "firmware", which is encoded in the QE firmware binary format. 4529This firmware often needs to be loaded during U-Boot booting, so macros 4530are used to identify the storage device (NOR flash, SPI, etc) and the address 4531within that device. 4532 4533- CONFIG_SYS_FMAN_FW_ADDR 4534 The address in the storage device where the FMAN microcode is located. The 4535 meaning of this address depends on which CONFIG_SYS_QE_FW_IN_xxx macro 4536 is also specified. 4537 4538- CONFIG_SYS_QE_FW_ADDR 4539 The address in the storage device where the QE microcode is located. The 4540 meaning of this address depends on which CONFIG_SYS_QE_FW_IN_xxx macro 4541 is also specified. 4542 4543- CONFIG_SYS_QE_FMAN_FW_LENGTH 4544 The maximum possible size of the firmware. The firmware binary format 4545 has a field that specifies the actual size of the firmware, but it 4546 might not be possible to read any part of the firmware unless some 4547 local storage is allocated to hold the entire firmware first. 4548 4549- CONFIG_SYS_QE_FMAN_FW_IN_NOR 4550 Specifies that QE/FMAN firmware is located in NOR flash, mapped as 4551 normal addressable memory via the LBC. CONFIG_SYS_FMAN_FW_ADDR is the 4552 virtual address in NOR flash. 4553 4554- CONFIG_SYS_QE_FMAN_FW_IN_NAND 4555 Specifies that QE/FMAN firmware is located in NAND flash. 4556 CONFIG_SYS_FMAN_FW_ADDR is the offset within NAND flash. 4557 4558- CONFIG_SYS_QE_FMAN_FW_IN_MMC 4559 Specifies that QE/FMAN firmware is located on the primary SD/MMC 4560 device. CONFIG_SYS_FMAN_FW_ADDR is the byte offset on that device. 4561 4562- CONFIG_SYS_QE_FMAN_FW_IN_REMOTE 4563 Specifies that QE/FMAN firmware is located in the remote (master) 4564 memory space. CONFIG_SYS_FMAN_FW_ADDR is a virtual address which 4565 can be mapped from slave TLB->slave LAW->slave SRIO or PCIE outbound 4566 window->master inbound window->master LAW->the ucode address in 4567 master's memory space. 4568 4569Freescale Layerscape Management Complex Firmware Support: 4570--------------------------------------------------------- 4571The Freescale Layerscape Management Complex (MC) supports the loading of 4572"firmware". 4573This firmware often needs to be loaded during U-Boot booting, so macros 4574are used to identify the storage device (NOR flash, SPI, etc) and the address 4575within that device. 4576 4577- CONFIG_FSL_MC_ENET 4578 Enable the MC driver for Layerscape SoCs. 4579 4580Freescale Layerscape Debug Server Support: 4581------------------------------------------- 4582The Freescale Layerscape Debug Server Support supports the loading of 4583"Debug Server firmware" and triggering SP boot-rom. 4584This firmware often needs to be loaded during U-Boot booting. 4585 4586- CONFIG_SYS_MC_RSV_MEM_ALIGN 4587 Define alignment of reserved memory MC requires 4588 4589Reproducible builds 4590------------------- 4591 4592In order to achieve reproducible builds, timestamps used in the U-Boot build 4593process have to be set to a fixed value. 4594 4595This is done using the SOURCE_DATE_EPOCH environment variable. 4596SOURCE_DATE_EPOCH is to be set on the build host's shell, not as a configuration 4597option for U-Boot or an environment variable in U-Boot. 4598 4599SOURCE_DATE_EPOCH should be set to a number of seconds since the epoch, in UTC. 4600 4601Building the Software: 4602====================== 4603 4604Building U-Boot has been tested in several native build environments 4605and in many different cross environments. Of course we cannot support 4606all possibly existing versions of cross development tools in all 4607(potentially obsolete) versions. In case of tool chain problems we 4608recommend to use the ELDK (see http://www.denx.de/wiki/DULG/ELDK) 4609which is extensively used to build and test U-Boot. 4610 4611If you are not using a native environment, it is assumed that you 4612have GNU cross compiling tools available in your path. In this case, 4613you must set the environment variable CROSS_COMPILE in your shell. 4614Note that no changes to the Makefile or any other source files are 4615necessary. For example using the ELDK on a 4xx CPU, please enter: 4616 4617 $ CROSS_COMPILE=ppc_4xx- 4618 $ export CROSS_COMPILE 4619 4620Note: If you wish to generate Windows versions of the utilities in 4621 the tools directory you can use the MinGW toolchain 4622 (http://www.mingw.org). Set your HOST tools to the MinGW 4623 toolchain and execute 'make tools'. For example: 4624 4625 $ make HOSTCC=i586-mingw32msvc-gcc HOSTSTRIP=i586-mingw32msvc-strip tools 4626 4627 Binaries such as tools/mkimage.exe will be created which can 4628 be executed on computers running Windows. 4629 4630U-Boot is intended to be simple to build. After installing the 4631sources you must configure U-Boot for one specific board type. This 4632is done by typing: 4633 4634 make NAME_defconfig 4635 4636where "NAME_defconfig" is the name of one of the existing configu- 4637rations; see boards.cfg for supported names. 4638 4639Note: for some board special configuration names may exist; check if 4640 additional information is available from the board vendor; for 4641 instance, the TQM823L systems are available without (standard) 4642 or with LCD support. You can select such additional "features" 4643 when choosing the configuration, i. e. 4644 4645 make TQM823L_defconfig 4646 - will configure for a plain TQM823L, i. e. no LCD support 4647 4648 make TQM823L_LCD_defconfig 4649 - will configure for a TQM823L with U-Boot console on LCD 4650 4651 etc. 4652 4653 4654Finally, type "make all", and you should get some working U-Boot 4655images ready for download to / installation on your system: 4656 4657- "u-boot.bin" is a raw binary image 4658- "u-boot" is an image in ELF binary format 4659- "u-boot.srec" is in Motorola S-Record format 4660 4661By default the build is performed locally and the objects are saved 4662in the source directory. One of the two methods can be used to change 4663this behavior and build U-Boot to some external directory: 4664 46651. Add O= to the make command line invocations: 4666 4667 make O=/tmp/build distclean 4668 make O=/tmp/build NAME_defconfig 4669 make O=/tmp/build all 4670 46712. Set environment variable KBUILD_OUTPUT to point to the desired location: 4672 4673 export KBUILD_OUTPUT=/tmp/build 4674 make distclean 4675 make NAME_defconfig 4676 make all 4677 4678Note that the command line "O=" setting overrides the KBUILD_OUTPUT environment 4679variable. 4680 4681 4682Please be aware that the Makefiles assume you are using GNU make, so 4683for instance on NetBSD you might need to use "gmake" instead of 4684native "make". 4685 4686 4687If the system board that you have is not listed, then you will need 4688to port U-Boot to your hardware platform. To do this, follow these 4689steps: 4690 46911. Create a new directory to hold your board specific code. Add any 4692 files you need. In your board directory, you will need at least 4693 the "Makefile" and a "<board>.c". 46942. Create a new configuration file "include/configs/<board>.h" for 4695 your board. 46963. If you're porting U-Boot to a new CPU, then also create a new 4697 directory to hold your CPU specific code. Add any files you need. 46984. Run "make <board>_defconfig" with your new name. 46995. Type "make", and you should get a working "u-boot.srec" file 4700 to be installed on your target system. 47016. Debug and solve any problems that might arise. 4702 [Of course, this last step is much harder than it sounds.] 4703 4704 4705Testing of U-Boot Modifications, Ports to New Hardware, etc.: 4706============================================================== 4707 4708If you have modified U-Boot sources (for instance added a new board 4709or support for new devices, a new CPU, etc.) you are expected to 4710provide feedback to the other developers. The feedback normally takes 4711the form of a "patch", i. e. a context diff against a certain (latest 4712official or latest in the git repository) version of U-Boot sources. 4713 4714But before you submit such a patch, please verify that your modifi- 4715cation did not break existing code. At least make sure that *ALL* of 4716the supported boards compile WITHOUT ANY compiler warnings. To do so, 4717just run the buildman script (tools/buildman/buildman), which will 4718configure and build U-Boot for ALL supported system. Be warned, this 4719will take a while. Please see the buildman README, or run 'buildman -H' 4720for documentation. 4721 4722 4723See also "U-Boot Porting Guide" below. 4724 4725 4726Monitor Commands - Overview: 4727============================ 4728 4729go - start application at address 'addr' 4730run - run commands in an environment variable 4731bootm - boot application image from memory 4732bootp - boot image via network using BootP/TFTP protocol 4733bootz - boot zImage from memory 4734tftpboot- boot image via network using TFTP protocol 4735 and env variables "ipaddr" and "serverip" 4736 (and eventually "gatewayip") 4737tftpput - upload a file via network using TFTP protocol 4738rarpboot- boot image via network using RARP/TFTP protocol 4739diskboot- boot from IDE devicebootd - boot default, i.e., run 'bootcmd' 4740loads - load S-Record file over serial line 4741loadb - load binary file over serial line (kermit mode) 4742md - memory display 4743mm - memory modify (auto-incrementing) 4744nm - memory modify (constant address) 4745mw - memory write (fill) 4746cp - memory copy 4747cmp - memory compare 4748crc32 - checksum calculation 4749i2c - I2C sub-system 4750sspi - SPI utility commands 4751base - print or set address offset 4752printenv- print environment variables 4753setenv - set environment variables 4754saveenv - save environment variables to persistent storage 4755protect - enable or disable FLASH write protection 4756erase - erase FLASH memory 4757flinfo - print FLASH memory information 4758nand - NAND memory operations (see doc/README.nand) 4759bdinfo - print Board Info structure 4760iminfo - print header information for application image 4761coninfo - print console devices and informations 4762ide - IDE sub-system 4763loop - infinite loop on address range 4764loopw - infinite write loop on address range 4765mtest - simple RAM test 4766icache - enable or disable instruction cache 4767dcache - enable or disable data cache 4768reset - Perform RESET of the CPU 4769echo - echo args to console 4770version - print monitor version 4771help - print online help 4772? - alias for 'help' 4773 4774 4775Monitor Commands - Detailed Description: 4776======================================== 4777 4778TODO. 4779 4780For now: just type "help <command>". 4781 4782 4783Environment Variables: 4784====================== 4785 4786U-Boot supports user configuration using Environment Variables which 4787can be made persistent by saving to Flash memory. 4788 4789Environment Variables are set using "setenv", printed using 4790"printenv", and saved to Flash using "saveenv". Using "setenv" 4791without a value can be used to delete a variable from the 4792environment. As long as you don't save the environment you are 4793working with an in-memory copy. In case the Flash area containing the 4794environment is erased by accident, a default environment is provided. 4795 4796Some configuration options can be set using Environment Variables. 4797 4798List of environment variables (most likely not complete): 4799 4800 baudrate - see CONFIG_BAUDRATE 4801 4802 bootdelay - see CONFIG_BOOTDELAY 4803 4804 bootcmd - see CONFIG_BOOTCOMMAND 4805 4806 bootargs - Boot arguments when booting an RTOS image 4807 4808 bootfile - Name of the image to load with TFTP 4809 4810 bootm_low - Memory range available for image processing in the bootm 4811 command can be restricted. This variable is given as 4812 a hexadecimal number and defines lowest address allowed 4813 for use by the bootm command. See also "bootm_size" 4814 environment variable. Address defined by "bootm_low" is 4815 also the base of the initial memory mapping for the Linux 4816 kernel -- see the description of CONFIG_SYS_BOOTMAPSZ and 4817 bootm_mapsize. 4818 4819 bootm_mapsize - Size of the initial memory mapping for the Linux kernel. 4820 This variable is given as a hexadecimal number and it 4821 defines the size of the memory region starting at base 4822 address bootm_low that is accessible by the Linux kernel 4823 during early boot. If unset, CONFIG_SYS_BOOTMAPSZ is used 4824 as the default value if it is defined, and bootm_size is 4825 used otherwise. 4826 4827 bootm_size - Memory range available for image processing in the bootm 4828 command can be restricted. This variable is given as 4829 a hexadecimal number and defines the size of the region 4830 allowed for use by the bootm command. See also "bootm_low" 4831 environment variable. 4832 4833 updatefile - Location of the software update file on a TFTP server, used 4834 by the automatic software update feature. Please refer to 4835 documentation in doc/README.update for more details. 4836 4837 autoload - if set to "no" (any string beginning with 'n'), 4838 "bootp" will just load perform a lookup of the 4839 configuration from the BOOTP server, but not try to 4840 load any image using TFTP 4841 4842 autostart - if set to "yes", an image loaded using the "bootp", 4843 "rarpboot", "tftpboot" or "diskboot" commands will 4844 be automatically started (by internally calling 4845 "bootm") 4846 4847 If set to "no", a standalone image passed to the 4848 "bootm" command will be copied to the load address 4849 (and eventually uncompressed), but NOT be started. 4850 This can be used to load and uncompress arbitrary 4851 data. 4852 4853 fdt_high - if set this restricts the maximum address that the 4854 flattened device tree will be copied into upon boot. 4855 For example, if you have a system with 1 GB memory 4856 at physical address 0x10000000, while Linux kernel 4857 only recognizes the first 704 MB as low memory, you 4858 may need to set fdt_high as 0x3C000000 to have the 4859 device tree blob be copied to the maximum address 4860 of the 704 MB low memory, so that Linux kernel can 4861 access it during the boot procedure. 4862 4863 If this is set to the special value 0xFFFFFFFF then 4864 the fdt will not be copied at all on boot. For this 4865 to work it must reside in writable memory, have 4866 sufficient padding on the end of it for u-boot to 4867 add the information it needs into it, and the memory 4868 must be accessible by the kernel. 4869 4870 fdtcontroladdr- if set this is the address of the control flattened 4871 device tree used by U-Boot when CONFIG_OF_CONTROL is 4872 defined. 4873 4874 i2cfast - (PPC405GP|PPC405EP only) 4875 if set to 'y' configures Linux I2C driver for fast 4876 mode (400kHZ). This environment variable is used in 4877 initialization code. So, for changes to be effective 4878 it must be saved and board must be reset. 4879 4880 initrd_high - restrict positioning of initrd images: 4881 If this variable is not set, initrd images will be 4882 copied to the highest possible address in RAM; this 4883 is usually what you want since it allows for 4884 maximum initrd size. If for some reason you want to 4885 make sure that the initrd image is loaded below the 4886 CONFIG_SYS_BOOTMAPSZ limit, you can set this environment 4887 variable to a value of "no" or "off" or "0". 4888 Alternatively, you can set it to a maximum upper 4889 address to use (U-Boot will still check that it 4890 does not overwrite the U-Boot stack and data). 4891 4892 For instance, when you have a system with 16 MB 4893 RAM, and want to reserve 4 MB from use by Linux, 4894 you can do this by adding "mem=12M" to the value of 4895 the "bootargs" variable. However, now you must make 4896 sure that the initrd image is placed in the first 4897 12 MB as well - this can be done with 4898 4899 setenv initrd_high 00c00000 4900 4901 If you set initrd_high to 0xFFFFFFFF, this is an 4902 indication to U-Boot that all addresses are legal 4903 for the Linux kernel, including addresses in flash 4904 memory. In this case U-Boot will NOT COPY the 4905 ramdisk at all. This may be useful to reduce the 4906 boot time on your system, but requires that this 4907 feature is supported by your Linux kernel. 4908 4909 ipaddr - IP address; needed for tftpboot command 4910 4911 loadaddr - Default load address for commands like "bootp", 4912 "rarpboot", "tftpboot", "loadb" or "diskboot" 4913 4914 loads_echo - see CONFIG_LOADS_ECHO 4915 4916 serverip - TFTP server IP address; needed for tftpboot command 4917 4918 bootretry - see CONFIG_BOOT_RETRY_TIME 4919 4920 bootdelaykey - see CONFIG_AUTOBOOT_DELAY_STR 4921 4922 bootstopkey - see CONFIG_AUTOBOOT_STOP_STR 4923 4924 ethprime - controls which interface is used first. 4925 4926 ethact - controls which interface is currently active. 4927 For example you can do the following 4928 4929 => setenv ethact FEC 4930 => ping 192.168.0.1 # traffic sent on FEC 4931 => setenv ethact SCC 4932 => ping 10.0.0.1 # traffic sent on SCC 4933 4934 ethrotate - When set to "no" U-Boot does not go through all 4935 available network interfaces. 4936 It just stays at the currently selected interface. 4937 4938 netretry - When set to "no" each network operation will 4939 either succeed or fail without retrying. 4940 When set to "once" the network operation will 4941 fail when all the available network interfaces 4942 are tried once without success. 4943 Useful on scripts which control the retry operation 4944 themselves. 4945 4946 npe_ucode - set load address for the NPE microcode 4947 4948 silent_linux - If set then Linux will be told to boot silently, by 4949 changing the console to be empty. If "yes" it will be 4950 made silent. If "no" it will not be made silent. If 4951 unset, then it will be made silent if the U-Boot console 4952 is silent. 4953 4954 tftpsrcp - If this is set, the value is used for TFTP's 4955 UDP source port. 4956 4957 tftpdstp - If this is set, the value is used for TFTP's UDP 4958 destination port instead of the Well Know Port 69. 4959 4960 tftpblocksize - Block size to use for TFTP transfers; if not set, 4961 we use the TFTP server's default block size 4962 4963 tftptimeout - Retransmission timeout for TFTP packets (in milli- 4964 seconds, minimum value is 1000 = 1 second). Defines 4965 when a packet is considered to be lost so it has to 4966 be retransmitted. The default is 5000 = 5 seconds. 4967 Lowering this value may make downloads succeed 4968 faster in networks with high packet loss rates or 4969 with unreliable TFTP servers. 4970 4971 tftptimeoutcountmax - maximum count of TFTP timeouts (no 4972 unit, minimum value = 0). Defines how many timeouts 4973 can happen during a single file transfer before that 4974 transfer is aborted. The default is 10, and 0 means 4975 'no timeouts allowed'. Increasing this value may help 4976 downloads succeed with high packet loss rates, or with 4977 unreliable TFTP servers or client hardware. 4978 4979 vlan - When set to a value < 4095 the traffic over 4980 Ethernet is encapsulated/received over 802.1q 4981 VLAN tagged frames. 4982 4983 bootpretryperiod - Period during which BOOTP/DHCP sends retries. 4984 Unsigned value, in milliseconds. If not set, the period will 4985 be either the default (28000), or a value based on 4986 CONFIG_NET_RETRY_COUNT, if defined. This value has 4987 precedence over the valu based on CONFIG_NET_RETRY_COUNT. 4988 4989The following image location variables contain the location of images 4990used in booting. The "Image" column gives the role of the image and is 4991not an environment variable name. The other columns are environment 4992variable names. "File Name" gives the name of the file on a TFTP 4993server, "RAM Address" gives the location in RAM the image will be 4994loaded to, and "Flash Location" gives the image's address in NOR 4995flash or offset in NAND flash. 4996 4997*Note* - these variables don't have to be defined for all boards, some 4998boards currently use other variables for these purposes, and some 4999boards use these variables for other purposes. 5000 5001Image File Name RAM Address Flash Location 5002----- --------- ----------- -------------- 5003u-boot u-boot u-boot_addr_r u-boot_addr 5004Linux kernel bootfile kernel_addr_r kernel_addr 5005device tree blob fdtfile fdt_addr_r fdt_addr 5006ramdisk ramdiskfile ramdisk_addr_r ramdisk_addr 5007 5008The following environment variables may be used and automatically 5009updated by the network boot commands ("bootp" and "rarpboot"), 5010depending the information provided by your boot server: 5011 5012 bootfile - see above 5013 dnsip - IP address of your Domain Name Server 5014 dnsip2 - IP address of your secondary Domain Name Server 5015 gatewayip - IP address of the Gateway (Router) to use 5016 hostname - Target hostname 5017 ipaddr - see above 5018 netmask - Subnet Mask 5019 rootpath - Pathname of the root filesystem on the NFS server 5020 serverip - see above 5021 5022 5023There are two special Environment Variables: 5024 5025 serial# - contains hardware identification information such 5026 as type string and/or serial number 5027 ethaddr - Ethernet address 5028 5029These variables can be set only once (usually during manufacturing of 5030the board). U-Boot refuses to delete or overwrite these variables 5031once they have been set once. 5032 5033 5034Further special Environment Variables: 5035 5036 ver - Contains the U-Boot version string as printed 5037 with the "version" command. This variable is 5038 readonly (see CONFIG_VERSION_VARIABLE). 5039 5040 5041Please note that changes to some configuration parameters may take 5042only effect after the next boot (yes, that's just like Windoze :-). 5043 5044 5045Callback functions for environment variables: 5046--------------------------------------------- 5047 5048For some environment variables, the behavior of u-boot needs to change 5049when their values are changed. This functionality allows functions to 5050be associated with arbitrary variables. On creation, overwrite, or 5051deletion, the callback will provide the opportunity for some side 5052effect to happen or for the change to be rejected. 5053 5054The callbacks are named and associated with a function using the 5055U_BOOT_ENV_CALLBACK macro in your board or driver code. 5056 5057These callbacks are associated with variables in one of two ways. The 5058static list can be added to by defining CONFIG_ENV_CALLBACK_LIST_STATIC 5059in the board configuration to a string that defines a list of 5060associations. The list must be in the following format: 5061 5062 entry = variable_name[:callback_name] 5063 list = entry[,list] 5064 5065If the callback name is not specified, then the callback is deleted. 5066Spaces are also allowed anywhere in the list. 5067 5068Callbacks can also be associated by defining the ".callbacks" variable 5069with the same list format above. Any association in ".callbacks" will 5070override any association in the static list. You can define 5071CONFIG_ENV_CALLBACK_LIST_DEFAULT to a list (string) to define the 5072".callbacks" environment variable in the default or embedded environment. 5073 5074If CONFIG_REGEX is defined, the variable_name above is evaluated as a 5075regular expression. This allows multiple variables to be connected to 5076the same callback without explicitly listing them all out. 5077 5078 5079Command Line Parsing: 5080===================== 5081 5082There are two different command line parsers available with U-Boot: 5083the old "simple" one, and the much more powerful "hush" shell: 5084 5085Old, simple command line parser: 5086-------------------------------- 5087 5088- supports environment variables (through setenv / saveenv commands) 5089- several commands on one line, separated by ';' 5090- variable substitution using "... ${name} ..." syntax 5091- special characters ('$', ';') can be escaped by prefixing with '\', 5092 for example: 5093 setenv bootcmd bootm \${address} 5094- You can also escape text by enclosing in single apostrophes, for example: 5095 setenv addip 'setenv bootargs $bootargs ip=$ipaddr:$serverip:$gatewayip:$netmask:$hostname::off' 5096 5097Hush shell: 5098----------- 5099 5100- similar to Bourne shell, with control structures like 5101 if...then...else...fi, for...do...done; while...do...done, 5102 until...do...done, ... 5103- supports environment ("global") variables (through setenv / saveenv 5104 commands) and local shell variables (through standard shell syntax 5105 "name=value"); only environment variables can be used with "run" 5106 command 5107 5108General rules: 5109-------------- 5110 5111(1) If a command line (or an environment variable executed by a "run" 5112 command) contains several commands separated by semicolon, and 5113 one of these commands fails, then the remaining commands will be 5114 executed anyway. 5115 5116(2) If you execute several variables with one call to run (i. e. 5117 calling run with a list of variables as arguments), any failing 5118 command will cause "run" to terminate, i. e. the remaining 5119 variables are not executed. 5120 5121Note for Redundant Ethernet Interfaces: 5122======================================= 5123 5124Some boards come with redundant Ethernet interfaces; U-Boot supports 5125such configurations and is capable of automatic selection of a 5126"working" interface when needed. MAC assignment works as follows: 5127 5128Network interfaces are numbered eth0, eth1, eth2, ... Corresponding 5129MAC addresses can be stored in the environment as "ethaddr" (=>eth0), 5130"eth1addr" (=>eth1), "eth2addr", ... 5131 5132If the network interface stores some valid MAC address (for instance 5133in SROM), this is used as default address if there is NO correspon- 5134ding setting in the environment; if the corresponding environment 5135variable is set, this overrides the settings in the card; that means: 5136 5137o If the SROM has a valid MAC address, and there is no address in the 5138 environment, the SROM's address is used. 5139 5140o If there is no valid address in the SROM, and a definition in the 5141 environment exists, then the value from the environment variable is 5142 used. 5143 5144o If both the SROM and the environment contain a MAC address, and 5145 both addresses are the same, this MAC address is used. 5146 5147o If both the SROM and the environment contain a MAC address, and the 5148 addresses differ, the value from the environment is used and a 5149 warning is printed. 5150 5151o If neither SROM nor the environment contain a MAC address, an error 5152 is raised. If CONFIG_NET_RANDOM_ETHADDR is defined, then in this case 5153 a random, locally-assigned MAC is used. 5154 5155If Ethernet drivers implement the 'write_hwaddr' function, valid MAC addresses 5156will be programmed into hardware as part of the initialization process. This 5157may be skipped by setting the appropriate 'ethmacskip' environment variable. 5158The naming convention is as follows: 5159"ethmacskip" (=>eth0), "eth1macskip" (=>eth1) etc. 5160 5161Image Formats: 5162============== 5163 5164U-Boot is capable of booting (and performing other auxiliary operations on) 5165images in two formats: 5166 5167New uImage format (FIT) 5168----------------------- 5169 5170Flexible and powerful format based on Flattened Image Tree -- FIT (similar 5171to Flattened Device Tree). It allows the use of images with multiple 5172components (several kernels, ramdisks, etc.), with contents protected by 5173SHA1, MD5 or CRC32. More details are found in the doc/uImage.FIT directory. 5174 5175 5176Old uImage format 5177----------------- 5178 5179Old image format is based on binary files which can be basically anything, 5180preceded by a special header; see the definitions in include/image.h for 5181details; basically, the header defines the following image properties: 5182 5183* Target Operating System (Provisions for OpenBSD, NetBSD, FreeBSD, 5184 4.4BSD, Linux, SVR4, Esix, Solaris, Irix, SCO, Dell, NCR, VxWorks, 5185 LynxOS, pSOS, QNX, RTEMS, INTEGRITY; 5186 Currently supported: Linux, NetBSD, VxWorks, QNX, RTEMS, LynxOS, 5187 INTEGRITY). 5188* Target CPU Architecture (Provisions for Alpha, ARM, AVR32, Intel x86, 5189 IA64, MIPS, NDS32, Nios II, PowerPC, IBM S390, SuperH, Sparc, Sparc 64 Bit; 5190 Currently supported: ARM, AVR32, Intel x86, MIPS, NDS32, Nios II, PowerPC). 5191* Compression Type (uncompressed, gzip, bzip2) 5192* Load Address 5193* Entry Point 5194* Image Name 5195* Image Timestamp 5196 5197The header is marked by a special Magic Number, and both the header 5198and the data portions of the image are secured against corruption by 5199CRC32 checksums. 5200 5201 5202Linux Support: 5203============== 5204 5205Although U-Boot should support any OS or standalone application 5206easily, the main focus has always been on Linux during the design of 5207U-Boot. 5208 5209U-Boot includes many features that so far have been part of some 5210special "boot loader" code within the Linux kernel. Also, any 5211"initrd" images to be used are no longer part of one big Linux image; 5212instead, kernel and "initrd" are separate images. This implementation 5213serves several purposes: 5214 5215- the same features can be used for other OS or standalone 5216 applications (for instance: using compressed images to reduce the 5217 Flash memory footprint) 5218 5219- it becomes much easier to port new Linux kernel versions because 5220 lots of low-level, hardware dependent stuff are done by U-Boot 5221 5222- the same Linux kernel image can now be used with different "initrd" 5223 images; of course this also means that different kernel images can 5224 be run with the same "initrd". This makes testing easier (you don't 5225 have to build a new "zImage.initrd" Linux image when you just 5226 change a file in your "initrd"). Also, a field-upgrade of the 5227 software is easier now. 5228 5229 5230Linux HOWTO: 5231============ 5232 5233Porting Linux to U-Boot based systems: 5234--------------------------------------- 5235 5236U-Boot cannot save you from doing all the necessary modifications to 5237configure the Linux device drivers for use with your target hardware 5238(no, we don't intend to provide a full virtual machine interface to 5239Linux :-). 5240 5241But now you can ignore ALL boot loader code (in arch/powerpc/mbxboot). 5242 5243Just make sure your machine specific header file (for instance 5244include/asm-ppc/tqm8xx.h) includes the same definition of the Board 5245Information structure as we define in include/asm-<arch>/u-boot.h, 5246and make sure that your definition of IMAP_ADDR uses the same value 5247as your U-Boot configuration in CONFIG_SYS_IMMR. 5248 5249Note that U-Boot now has a driver model, a unified model for drivers. 5250If you are adding a new driver, plumb it into driver model. If there 5251is no uclass available, you are encouraged to create one. See 5252doc/driver-model. 5253 5254 5255Configuring the Linux kernel: 5256----------------------------- 5257 5258No specific requirements for U-Boot. Make sure you have some root 5259device (initial ramdisk, NFS) for your target system. 5260 5261 5262Building a Linux Image: 5263----------------------- 5264 5265With U-Boot, "normal" build targets like "zImage" or "bzImage" are 5266not used. If you use recent kernel source, a new build target 5267"uImage" will exist which automatically builds an image usable by 5268U-Boot. Most older kernels also have support for a "pImage" target, 5269which was introduced for our predecessor project PPCBoot and uses a 5270100% compatible format. 5271 5272Example: 5273 5274 make TQM850L_defconfig 5275 make oldconfig 5276 make dep 5277 make uImage 5278 5279The "uImage" build target uses a special tool (in 'tools/mkimage') to 5280encapsulate a compressed Linux kernel image with header information, 5281CRC32 checksum etc. for use with U-Boot. This is what we are doing: 5282 5283* build a standard "vmlinux" kernel image (in ELF binary format): 5284 5285* convert the kernel into a raw binary image: 5286 5287 ${CROSS_COMPILE}-objcopy -O binary \ 5288 -R .note -R .comment \ 5289 -S vmlinux linux.bin 5290 5291* compress the binary image: 5292 5293 gzip -9 linux.bin 5294 5295* package compressed binary image for U-Boot: 5296 5297 mkimage -A ppc -O linux -T kernel -C gzip \ 5298 -a 0 -e 0 -n "Linux Kernel Image" \ 5299 -d linux.bin.gz uImage 5300 5301 5302The "mkimage" tool can also be used to create ramdisk images for use 5303with U-Boot, either separated from the Linux kernel image, or 5304combined into one file. "mkimage" encapsulates the images with a 64 5305byte header containing information about target architecture, 5306operating system, image type, compression method, entry points, time 5307stamp, CRC32 checksums, etc. 5308 5309"mkimage" can be called in two ways: to verify existing images and 5310print the header information, or to build new images. 5311 5312In the first form (with "-l" option) mkimage lists the information 5313contained in the header of an existing U-Boot image; this includes 5314checksum verification: 5315 5316 tools/mkimage -l image 5317 -l ==> list image header information 5318 5319The second form (with "-d" option) is used to build a U-Boot image 5320from a "data file" which is used as image payload: 5321 5322 tools/mkimage -A arch -O os -T type -C comp -a addr -e ep \ 5323 -n name -d data_file image 5324 -A ==> set architecture to 'arch' 5325 -O ==> set operating system to 'os' 5326 -T ==> set image type to 'type' 5327 -C ==> set compression type 'comp' 5328 -a ==> set load address to 'addr' (hex) 5329 -e ==> set entry point to 'ep' (hex) 5330 -n ==> set image name to 'name' 5331 -d ==> use image data from 'datafile' 5332 5333Right now, all Linux kernels for PowerPC systems use the same load 5334address (0x00000000), but the entry point address depends on the 5335kernel version: 5336 5337- 2.2.x kernels have the entry point at 0x0000000C, 5338- 2.3.x and later kernels have the entry point at 0x00000000. 5339 5340So a typical call to build a U-Boot image would read: 5341 5342 -> tools/mkimage -n '2.4.4 kernel for TQM850L' \ 5343 > -A ppc -O linux -T kernel -C gzip -a 0 -e 0 \ 5344 > -d /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/powerpc/coffboot/vmlinux.gz \ 5345 > examples/uImage.TQM850L 5346 Image Name: 2.4.4 kernel for TQM850L 5347 Created: Wed Jul 19 02:34:59 2000 5348 Image Type: PowerPC Linux Kernel Image (gzip compressed) 5349 Data Size: 335725 Bytes = 327.86 kB = 0.32 MB 5350 Load Address: 0x00000000 5351 Entry Point: 0x00000000 5352 5353To verify the contents of the image (or check for corruption): 5354 5355 -> tools/mkimage -l 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 5363NOTE: for embedded systems where boot time is critical you can trade 5364speed for memory and install an UNCOMPRESSED image instead: this 5365needs more space in Flash, but boots much faster since it does not 5366need to be uncompressed: 5367 5368 -> gunzip /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/powerpc/coffboot/vmlinux.gz 5369 -> tools/mkimage -n '2.4.4 kernel for TQM850L' \ 5370 > -A ppc -O linux -T kernel -C none -a 0 -e 0 \ 5371 > -d /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/powerpc/coffboot/vmlinux \ 5372 > examples/uImage.TQM850L-uncompressed 5373 Image Name: 2.4.4 kernel for TQM850L 5374 Created: Wed Jul 19 02:34:59 2000 5375 Image Type: PowerPC Linux Kernel Image (uncompressed) 5376 Data Size: 792160 Bytes = 773.59 kB = 0.76 MB 5377 Load Address: 0x00000000 5378 Entry Point: 0x00000000 5379 5380 5381Similar you can build U-Boot images from a 'ramdisk.image.gz' file 5382when your kernel is intended to use an initial ramdisk: 5383 5384 -> tools/mkimage -n 'Simple Ramdisk Image' \ 5385 > -A ppc -O linux -T ramdisk -C gzip \ 5386 > -d /LinuxPPC/images/SIMPLE-ramdisk.image.gz examples/simple-initrd 5387 Image Name: Simple Ramdisk Image 5388 Created: Wed Jan 12 14:01:50 2000 5389 Image Type: PowerPC Linux RAMDisk Image (gzip compressed) 5390 Data Size: 566530 Bytes = 553.25 kB = 0.54 MB 5391 Load Address: 0x00000000 5392 Entry Point: 0x00000000 5393 5394The "dumpimage" is a tool to disassemble images built by mkimage. Its "-i" 5395option performs the converse operation of the mkimage's second form (the "-d" 5396option). Given an image built by mkimage, the dumpimage extracts a "data file" 5397from the image: 5398 5399 tools/dumpimage -i image -T type -p position data_file 5400 -i ==> extract from the 'image' a specific 'data_file' 5401 -T ==> set image type to 'type' 5402 -p ==> 'position' (starting at 0) of the 'data_file' inside the 'image' 5403 5404 5405Installing a Linux Image: 5406------------------------- 5407 5408To downloading a U-Boot image over the serial (console) interface, 5409you must convert the image to S-Record format: 5410 5411 objcopy -I binary -O srec examples/image examples/image.srec 5412 5413The 'objcopy' does not understand the information in the U-Boot 5414image header, so the resulting S-Record file will be relative to 5415address 0x00000000. To load it to a given address, you need to 5416specify the target address as 'offset' parameter with the 'loads' 5417command. 5418 5419Example: install the image to address 0x40100000 (which on the 5420TQM8xxL is in the first Flash bank): 5421 5422 => erase 40100000 401FFFFF 5423 5424 .......... done 5425 Erased 8 sectors 5426 5427 => loads 40100000 5428 ## Ready for S-Record download ... 5429 ~>examples/image.srec 5430 1 2 3 4 5 6 7 8 9 10 11 12 13 ... 5431 ... 5432 15989 15990 15991 15992 5433 [file transfer complete] 5434 [connected] 5435 ## Start Addr = 0x00000000 5436 5437 5438You can check the success of the download using the 'iminfo' command; 5439this includes a checksum verification so you can be sure no data 5440corruption happened: 5441 5442 => imi 40100000 5443 5444 ## Checking Image at 40100000 ... 5445 Image Name: 2.2.13 for initrd on TQM850L 5446 Image Type: PowerPC Linux Kernel Image (gzip compressed) 5447 Data Size: 335725 Bytes = 327 kB = 0 MB 5448 Load Address: 00000000 5449 Entry Point: 0000000c 5450 Verifying Checksum ... OK 5451 5452 5453Boot Linux: 5454----------- 5455 5456The "bootm" command is used to boot an application that is stored in 5457memory (RAM or Flash). In case of a Linux kernel image, the contents 5458of the "bootargs" environment variable is passed to the kernel as 5459parameters. You can check and modify this variable using the 5460"printenv" and "setenv" commands: 5461 5462 5463 => printenv bootargs 5464 bootargs=root=/dev/ram 5465 5466 => setenv bootargs root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2 5467 5468 => printenv bootargs 5469 bootargs=root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2 5470 5471 => bootm 40020000 5472 ## Booting Linux kernel at 40020000 ... 5473 Image Name: 2.2.13 for NFS on TQM850L 5474 Image Type: PowerPC Linux Kernel Image (gzip compressed) 5475 Data Size: 381681 Bytes = 372 kB = 0 MB 5476 Load Address: 00000000 5477 Entry Point: 0000000c 5478 Verifying Checksum ... OK 5479 Uncompressing Kernel Image ... OK 5480 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 5481 Boot arguments: root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2 5482 time_init: decrementer frequency = 187500000/60 5483 Calibrating delay loop... 49.77 BogoMIPS 5484 Memory: 15208k available (700k kernel code, 444k data, 32k init) [c0000000,c1000000] 5485 ... 5486 5487If you want to boot a Linux kernel with initial RAM disk, you pass 5488the memory addresses of both the kernel and the initrd image (PPBCOOT 5489format!) to the "bootm" command: 5490 5491 => imi 40100000 40200000 5492 5493 ## Checking Image at 40100000 ... 5494 Image Name: 2.2.13 for initrd on TQM850L 5495 Image Type: PowerPC Linux Kernel Image (gzip compressed) 5496 Data Size: 335725 Bytes = 327 kB = 0 MB 5497 Load Address: 00000000 5498 Entry Point: 0000000c 5499 Verifying Checksum ... OK 5500 5501 ## Checking Image at 40200000 ... 5502 Image Name: Simple Ramdisk Image 5503 Image Type: PowerPC Linux RAMDisk Image (gzip compressed) 5504 Data Size: 566530 Bytes = 553 kB = 0 MB 5505 Load Address: 00000000 5506 Entry Point: 00000000 5507 Verifying Checksum ... OK 5508 5509 => bootm 40100000 40200000 5510 ## Booting Linux kernel at 40100000 ... 5511 Image Name: 2.2.13 for initrd on TQM850L 5512 Image Type: PowerPC Linux Kernel Image (gzip compressed) 5513 Data Size: 335725 Bytes = 327 kB = 0 MB 5514 Load Address: 00000000 5515 Entry Point: 0000000c 5516 Verifying Checksum ... OK 5517 Uncompressing Kernel Image ... OK 5518 ## Loading RAMDisk Image at 40200000 ... 5519 Image Name: Simple Ramdisk Image 5520 Image Type: PowerPC Linux RAMDisk Image (gzip compressed) 5521 Data Size: 566530 Bytes = 553 kB = 0 MB 5522 Load Address: 00000000 5523 Entry Point: 00000000 5524 Verifying Checksum ... OK 5525 Loading Ramdisk ... OK 5526 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 5527 Boot arguments: root=/dev/ram 5528 time_init: decrementer frequency = 187500000/60 5529 Calibrating delay loop... 49.77 BogoMIPS 5530 ... 5531 RAMDISK: Compressed image found at block 0 5532 VFS: Mounted root (ext2 filesystem). 5533 5534 bash# 5535 5536Boot Linux and pass a flat device tree: 5537----------- 5538 5539First, U-Boot must be compiled with the appropriate defines. See the section 5540titled "Linux Kernel Interface" above for a more in depth explanation. The 5541following is an example of how to start a kernel and pass an updated 5542flat device tree: 5543 5544=> print oftaddr 5545oftaddr=0x300000 5546=> print oft 5547oft=oftrees/mpc8540ads.dtb 5548=> tftp $oftaddr $oft 5549Speed: 1000, full duplex 5550Using TSEC0 device 5551TFTP from server 192.168.1.1; our IP address is 192.168.1.101 5552Filename 'oftrees/mpc8540ads.dtb'. 5553Load address: 0x300000 5554Loading: # 5555done 5556Bytes transferred = 4106 (100a hex) 5557=> tftp $loadaddr $bootfile 5558Speed: 1000, full duplex 5559Using TSEC0 device 5560TFTP from server 192.168.1.1; our IP address is 192.168.1.2 5561Filename 'uImage'. 5562Load address: 0x200000 5563Loading:############ 5564done 5565Bytes transferred = 1029407 (fb51f hex) 5566=> print loadaddr 5567loadaddr=200000 5568=> print oftaddr 5569oftaddr=0x300000 5570=> bootm $loadaddr - $oftaddr 5571## Booting image at 00200000 ... 5572 Image Name: Linux-2.6.17-dirty 5573 Image Type: PowerPC Linux Kernel Image (gzip compressed) 5574 Data Size: 1029343 Bytes = 1005.2 kB 5575 Load Address: 00000000 5576 Entry Point: 00000000 5577 Verifying Checksum ... OK 5578 Uncompressing Kernel Image ... OK 5579Booting using flat device tree at 0x300000 5580Using MPC85xx ADS machine description 5581Memory CAM mapping: CAM0=256Mb, CAM1=256Mb, CAM2=0Mb residual: 0Mb 5582[snip] 5583 5584 5585More About U-Boot Image Types: 5586------------------------------ 5587 5588U-Boot supports the following image types: 5589 5590 "Standalone Programs" are directly runnable in the environment 5591 provided by U-Boot; it is expected that (if they behave 5592 well) you can continue to work in U-Boot after return from 5593 the Standalone Program. 5594 "OS Kernel Images" are usually images of some Embedded OS which 5595 will take over control completely. Usually these programs 5596 will install their own set of exception handlers, device 5597 drivers, set up the MMU, etc. - this means, that you cannot 5598 expect to re-enter U-Boot except by resetting the CPU. 5599 "RAMDisk Images" are more or less just data blocks, and their 5600 parameters (address, size) are passed to an OS kernel that is 5601 being started. 5602 "Multi-File Images" contain several images, typically an OS 5603 (Linux) kernel image and one or more data images like 5604 RAMDisks. This construct is useful for instance when you want 5605 to boot over the network using BOOTP etc., where the boot 5606 server provides just a single image file, but you want to get 5607 for instance an OS kernel and a RAMDisk image. 5608 5609 "Multi-File Images" start with a list of image sizes, each 5610 image size (in bytes) specified by an "uint32_t" in network 5611 byte order. This list is terminated by an "(uint32_t)0". 5612 Immediately after the terminating 0 follow the images, one by 5613 one, all aligned on "uint32_t" boundaries (size rounded up to 5614 a multiple of 4 bytes). 5615 5616 "Firmware Images" are binary images containing firmware (like 5617 U-Boot or FPGA images) which usually will be programmed to 5618 flash memory. 5619 5620 "Script files" are command sequences that will be executed by 5621 U-Boot's command interpreter; this feature is especially 5622 useful when you configure U-Boot to use a real shell (hush) 5623 as command interpreter. 5624 5625Booting the Linux zImage: 5626------------------------- 5627 5628On some platforms, it's possible to boot Linux zImage. This is done 5629using the "bootz" command. The syntax of "bootz" command is the same 5630as the syntax of "bootm" command. 5631 5632Note, defining the CONFIG_SUPPORT_RAW_INITRD allows user to supply 5633kernel with raw initrd images. The syntax is slightly different, the 5634address of the initrd must be augmented by it's size, in the following 5635format: "<initrd addres>:<initrd size>". 5636 5637 5638Standalone HOWTO: 5639================= 5640 5641One of the features of U-Boot is that you can dynamically load and 5642run "standalone" applications, which can use some resources of 5643U-Boot like console I/O functions or interrupt services. 5644 5645Two simple examples are included with the sources: 5646 5647"Hello World" Demo: 5648------------------- 5649 5650'examples/hello_world.c' contains a small "Hello World" Demo 5651application; it is automatically compiled when you build U-Boot. 5652It's configured to run at address 0x00040004, so you can play with it 5653like that: 5654 5655 => loads 5656 ## Ready for S-Record download ... 5657 ~>examples/hello_world.srec 5658 1 2 3 4 5 6 7 8 9 10 11 ... 5659 [file transfer complete] 5660 [connected] 5661 ## Start Addr = 0x00040004 5662 5663 => go 40004 Hello World! This is a test. 5664 ## Starting application at 0x00040004 ... 5665 Hello World 5666 argc = 7 5667 argv[0] = "40004" 5668 argv[1] = "Hello" 5669 argv[2] = "World!" 5670 argv[3] = "This" 5671 argv[4] = "is" 5672 argv[5] = "a" 5673 argv[6] = "test." 5674 argv[7] = "<NULL>" 5675 Hit any key to exit ... 5676 5677 ## Application terminated, rc = 0x0 5678 5679Another example, which demonstrates how to register a CPM interrupt 5680handler with the U-Boot code, can be found in 'examples/timer.c'. 5681Here, a CPM timer is set up to generate an interrupt every second. 5682The interrupt service routine is trivial, just printing a '.' 5683character, but this is just a demo program. The application can be 5684controlled by the following keys: 5685 5686 ? - print current values og the CPM Timer registers 5687 b - enable interrupts and start timer 5688 e - stop timer and disable interrupts 5689 q - quit application 5690 5691 => loads 5692 ## Ready for S-Record download ... 5693 ~>examples/timer.srec 5694 1 2 3 4 5 6 7 8 9 10 11 ... 5695 [file transfer complete] 5696 [connected] 5697 ## Start Addr = 0x00040004 5698 5699 => go 40004 5700 ## Starting application at 0x00040004 ... 5701 TIMERS=0xfff00980 5702 Using timer 1 5703 tgcr @ 0xfff00980, tmr @ 0xfff00990, trr @ 0xfff00994, tcr @ 0xfff00998, tcn @ 0xfff0099c, ter @ 0xfff009b0 5704 5705Hit 'b': 5706 [q, b, e, ?] Set interval 1000000 us 5707 Enabling timer 5708Hit '?': 5709 [q, b, e, ?] ........ 5710 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0xef6, ter=0x0 5711Hit '?': 5712 [q, b, e, ?] . 5713 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x2ad4, ter=0x0 5714Hit '?': 5715 [q, b, e, ?] . 5716 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x1efc, ter=0x0 5717Hit '?': 5718 [q, b, e, ?] . 5719 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x169d, ter=0x0 5720Hit 'e': 5721 [q, b, e, ?] ...Stopping timer 5722Hit 'q': 5723 [q, b, e, ?] ## Application terminated, rc = 0x0 5724 5725 5726Minicom warning: 5727================ 5728 5729Over time, many people have reported problems when trying to use the 5730"minicom" terminal emulation program for serial download. I (wd) 5731consider minicom to be broken, and recommend not to use it. Under 5732Unix, I recommend to use C-Kermit for general purpose use (and 5733especially for kermit binary protocol download ("loadb" command), and 5734use "cu" for S-Record download ("loads" command). See 5735http://www.denx.de/wiki/view/DULG/SystemSetup#Section_4.3. 5736for help with kermit. 5737 5738 5739Nevertheless, if you absolutely want to use it try adding this 5740configuration to your "File transfer protocols" section: 5741 5742 Name Program Name U/D FullScr IO-Red. Multi 5743 X kermit /usr/bin/kermit -i -l %l -s Y U Y N N 5744 Y kermit /usr/bin/kermit -i -l %l -r N D Y N N 5745 5746 5747NetBSD Notes: 5748============= 5749 5750Starting at version 0.9.2, U-Boot supports NetBSD both as host 5751(build U-Boot) and target system (boots NetBSD/mpc8xx). 5752 5753Building requires a cross environment; it is known to work on 5754NetBSD/i386 with the cross-powerpc-netbsd-1.3 package (you will also 5755need gmake since the Makefiles are not compatible with BSD make). 5756Note that the cross-powerpc package does not install include files; 5757attempting to build U-Boot will fail because <machine/ansi.h> is 5758missing. This file has to be installed and patched manually: 5759 5760 # cd /usr/pkg/cross/powerpc-netbsd/include 5761 # mkdir powerpc 5762 # ln -s powerpc machine 5763 # cp /usr/src/sys/arch/powerpc/include/ansi.h powerpc/ansi.h 5764 # ${EDIT} powerpc/ansi.h ## must remove __va_list, _BSD_VA_LIST 5765 5766Native builds *don't* work due to incompatibilities between native 5767and U-Boot include files. 5768 5769Booting assumes that (the first part of) the image booted is a 5770stage-2 loader which in turn loads and then invokes the kernel 5771proper. Loader sources will eventually appear in the NetBSD source 5772tree (probably in sys/arc/mpc8xx/stand/u-boot_stage2/); in the 5773meantime, see ftp://ftp.denx.de/pub/u-boot/ppcboot_stage2.tar.gz 5774 5775 5776Implementation Internals: 5777========================= 5778 5779The following is not intended to be a complete description of every 5780implementation detail. However, it should help to understand the 5781inner workings of U-Boot and make it easier to port it to custom 5782hardware. 5783 5784 5785Initial Stack, Global Data: 5786--------------------------- 5787 5788The implementation of U-Boot is complicated by the fact that U-Boot 5789starts running out of ROM (flash memory), usually without access to 5790system RAM (because the memory controller is not initialized yet). 5791This means that we don't have writable Data or BSS segments, and BSS 5792is not initialized as zero. To be able to get a C environment working 5793at all, we have to allocate at least a minimal stack. Implementation 5794options for this are defined and restricted by the CPU used: Some CPU 5795models provide on-chip memory (like the IMMR area on MPC8xx and 5796MPC826x processors), on others (parts of) the data cache can be 5797locked as (mis-) used as memory, etc. 5798 5799 Chris Hallinan posted a good summary of these issues to the 5800 U-Boot mailing list: 5801 5802 Subject: RE: [U-Boot-Users] RE: More On Memory Bank x (nothingness)? 5803 From: "Chris Hallinan" <clh@net1plus.com> 5804 Date: Mon, 10 Feb 2003 16:43:46 -0500 (22:43 MET) 5805 ... 5806 5807 Correct me if I'm wrong, folks, but the way I understand it 5808 is this: Using DCACHE as initial RAM for Stack, etc, does not 5809 require any physical RAM backing up the cache. The cleverness 5810 is that the cache is being used as a temporary supply of 5811 necessary storage before the SDRAM controller is setup. It's 5812 beyond the scope of this list to explain the details, but you 5813 can see how this works by studying the cache architecture and 5814 operation in the architecture and processor-specific manuals. 5815 5816 OCM is On Chip Memory, which I believe the 405GP has 4K. It 5817 is another option for the system designer to use as an 5818 initial stack/RAM area prior to SDRAM being available. Either 5819 option should work for you. Using CS 4 should be fine if your 5820 board designers haven't used it for something that would 5821 cause you grief during the initial boot! It is frequently not 5822 used. 5823 5824 CONFIG_SYS_INIT_RAM_ADDR should be somewhere that won't interfere 5825 with your processor/board/system design. The default value 5826 you will find in any recent u-boot distribution in 5827 walnut.h should work for you. I'd set it to a value larger 5828 than your SDRAM module. If you have a 64MB SDRAM module, set 5829 it above 400_0000. Just make sure your board has no resources 5830 that are supposed to respond to that address! That code in 5831 start.S has been around a while and should work as is when 5832 you get the config right. 5833 5834 -Chris Hallinan 5835 DS4.COM, Inc. 5836 5837It is essential to remember this, since it has some impact on the C 5838code for the initialization procedures: 5839 5840* Initialized global data (data segment) is read-only. Do not attempt 5841 to write it. 5842 5843* Do not use any uninitialized global data (or implicitly initialized 5844 as zero data - BSS segment) at all - this is undefined, initiali- 5845 zation is performed later (when relocating to RAM). 5846 5847* Stack space is very limited. Avoid big data buffers or things like 5848 that. 5849 5850Having only the stack as writable memory limits means we cannot use 5851normal global data to share information between the code. But it 5852turned out that the implementation of U-Boot can be greatly 5853simplified by making a global data structure (gd_t) available to all 5854functions. We could pass a pointer to this data as argument to _all_ 5855functions, but this would bloat the code. Instead we use a feature of 5856the GCC compiler (Global Register Variables) to share the data: we 5857place a pointer (gd) to the global data into a register which we 5858reserve for this purpose. 5859 5860When choosing a register for such a purpose we are restricted by the 5861relevant (E)ABI specifications for the current architecture, and by 5862GCC's implementation. 5863 5864For PowerPC, the following registers have specific use: 5865 R1: stack pointer 5866 R2: reserved for system use 5867 R3-R4: parameter passing and return values 5868 R5-R10: parameter passing 5869 R13: small data area pointer 5870 R30: GOT pointer 5871 R31: frame pointer 5872 5873 (U-Boot also uses R12 as internal GOT pointer. r12 5874 is a volatile register so r12 needs to be reset when 5875 going back and forth between asm and C) 5876 5877 ==> U-Boot will use R2 to hold a pointer to the global data 5878 5879 Note: on PPC, we could use a static initializer (since the 5880 address of the global data structure is known at compile time), 5881 but it turned out that reserving a register results in somewhat 5882 smaller code - although the code savings are not that big (on 5883 average for all boards 752 bytes for the whole U-Boot image, 5884 624 text + 127 data). 5885 5886On ARM, the following registers are used: 5887 5888 R0: function argument word/integer result 5889 R1-R3: function argument word 5890 R9: platform specific 5891 R10: stack limit (used only if stack checking is enabled) 5892 R11: argument (frame) pointer 5893 R12: temporary workspace 5894 R13: stack pointer 5895 R14: link register 5896 R15: program counter 5897 5898 ==> U-Boot will use R9 to hold a pointer to the global data 5899 5900 Note: on ARM, only R_ARM_RELATIVE relocations are supported. 5901 5902On Nios II, the ABI is documented here: 5903 http://www.altera.com/literature/hb/nios2/n2cpu_nii51016.pdf 5904 5905 ==> U-Boot will use gp to hold a pointer to the global data 5906 5907 Note: on Nios II, we give "-G0" option to gcc and don't use gp 5908 to access small data sections, so gp is free. 5909 5910On NDS32, the following registers are used: 5911 5912 R0-R1: argument/return 5913 R2-R5: argument 5914 R15: temporary register for assembler 5915 R16: trampoline register 5916 R28: frame pointer (FP) 5917 R29: global pointer (GP) 5918 R30: link register (LP) 5919 R31: stack pointer (SP) 5920 PC: program counter (PC) 5921 5922 ==> U-Boot will use R10 to hold a pointer to the global data 5923 5924NOTE: DECLARE_GLOBAL_DATA_PTR must be used with file-global scope, 5925or current versions of GCC may "optimize" the code too much. 5926 5927Memory Management: 5928------------------ 5929 5930U-Boot runs in system state and uses physical addresses, i.e. the 5931MMU is not used either for address mapping nor for memory protection. 5932 5933The available memory is mapped to fixed addresses using the memory 5934controller. In this process, a contiguous block is formed for each 5935memory type (Flash, SDRAM, SRAM), even when it consists of several 5936physical memory banks. 5937 5938U-Boot is installed in the first 128 kB of the first Flash bank (on 5939TQM8xxL modules this is the range 0x40000000 ... 0x4001FFFF). After 5940booting and sizing and initializing DRAM, the code relocates itself 5941to the upper end of DRAM. Immediately below the U-Boot code some 5942memory is reserved for use by malloc() [see CONFIG_SYS_MALLOC_LEN 5943configuration setting]. Below that, a structure with global Board 5944Info data is placed, followed by the stack (growing downward). 5945 5946Additionally, some exception handler code is copied to the low 8 kB 5947of DRAM (0x00000000 ... 0x00001FFF). 5948 5949So a typical memory configuration with 16 MB of DRAM could look like 5950this: 5951 5952 0x0000 0000 Exception Vector code 5953 : 5954 0x0000 1FFF 5955 0x0000 2000 Free for Application Use 5956 : 5957 : 5958 5959 : 5960 : 5961 0x00FB FF20 Monitor Stack (Growing downward) 5962 0x00FB FFAC Board Info Data and permanent copy of global data 5963 0x00FC 0000 Malloc Arena 5964 : 5965 0x00FD FFFF 5966 0x00FE 0000 RAM Copy of Monitor Code 5967 ... eventually: LCD or video framebuffer 5968 ... eventually: pRAM (Protected RAM - unchanged by reset) 5969 0x00FF FFFF [End of RAM] 5970 5971 5972System Initialization: 5973---------------------- 5974 5975In the reset configuration, U-Boot starts at the reset entry point 5976(on most PowerPC systems at address 0x00000100). Because of the reset 5977configuration for CS0# this is a mirror of the on board Flash memory. 5978To be able to re-map memory U-Boot then jumps to its link address. 5979To be able to implement the initialization code in C, a (small!) 5980initial stack is set up in the internal Dual Ported RAM (in case CPUs 5981which provide such a feature like MPC8xx or MPC8260), or in a locked 5982part of the data cache. After that, U-Boot initializes the CPU core, 5983the caches and the SIU. 5984 5985Next, all (potentially) available memory banks are mapped using a 5986preliminary mapping. For example, we put them on 512 MB boundaries 5987(multiples of 0x20000000: SDRAM on 0x00000000 and 0x20000000, Flash 5988on 0x40000000 and 0x60000000, SRAM on 0x80000000). Then UPM A is 5989programmed for SDRAM access. Using the temporary configuration, a 5990simple memory test is run that determines the size of the SDRAM 5991banks. 5992 5993When there is more than one SDRAM bank, and the banks are of 5994different size, the largest is mapped first. For equal size, the first 5995bank (CS2#) is mapped first. The first mapping is always for address 59960x00000000, with any additional banks following immediately to create 5997contiguous memory starting from 0. 5998 5999Then, the monitor installs itself at the upper end of the SDRAM area 6000and allocates memory for use by malloc() and for the global Board 6001Info data; also, the exception vector code is copied to the low RAM 6002pages, and the final stack is set up. 6003 6004Only after this relocation will you have a "normal" C environment; 6005until that you are restricted in several ways, mostly because you are 6006running from ROM, and because the code will have to be relocated to a 6007new address in RAM. 6008 6009 6010U-Boot Porting Guide: 6011---------------------- 6012 6013[Based on messages by Jerry Van Baren in the U-Boot-Users mailing 6014list, October 2002] 6015 6016 6017int main(int argc, char *argv[]) 6018{ 6019 sighandler_t no_more_time; 6020 6021 signal(SIGALRM, no_more_time); 6022 alarm(PROJECT_DEADLINE - toSec (3 * WEEK)); 6023 6024 if (available_money > available_manpower) { 6025 Pay consultant to port U-Boot; 6026 return 0; 6027 } 6028 6029 Download latest U-Boot source; 6030 6031 Subscribe to u-boot mailing list; 6032 6033 if (clueless) 6034 email("Hi, I am new to U-Boot, how do I get started?"); 6035 6036 while (learning) { 6037 Read the README file in the top level directory; 6038 Read http://www.denx.de/twiki/bin/view/DULG/Manual; 6039 Read applicable doc/*.README; 6040 Read the source, Luke; 6041 /* find . -name "*.[chS]" | xargs grep -i <keyword> */ 6042 } 6043 6044 if (available_money > toLocalCurrency ($2500)) 6045 Buy a BDI3000; 6046 else 6047 Add a lot of aggravation and time; 6048 6049 if (a similar board exists) { /* hopefully... */ 6050 cp -a board/<similar> board/<myboard> 6051 cp include/configs/<similar>.h include/configs/<myboard>.h 6052 } else { 6053 Create your own board support subdirectory; 6054 Create your own board include/configs/<myboard>.h file; 6055 } 6056 Edit new board/<myboard> files 6057 Edit new include/configs/<myboard>.h 6058 6059 while (!accepted) { 6060 while (!running) { 6061 do { 6062 Add / modify source code; 6063 } until (compiles); 6064 Debug; 6065 if (clueless) 6066 email("Hi, I am having problems..."); 6067 } 6068 Send patch file to the U-Boot email list; 6069 if (reasonable critiques) 6070 Incorporate improvements from email list code review; 6071 else 6072 Defend code as written; 6073 } 6074 6075 return 0; 6076} 6077 6078void no_more_time (int sig) 6079{ 6080 hire_a_guru(); 6081} 6082 6083 6084Coding Standards: 6085----------------- 6086 6087All contributions to U-Boot should conform to the Linux kernel 6088coding style; see the file "Documentation/CodingStyle" and the script 6089"scripts/Lindent" in your Linux kernel source directory. 6090 6091Source files originating from a different project (for example the 6092MTD subsystem) are generally exempt from these guidelines and are not 6093reformatted to ease subsequent migration to newer versions of those 6094sources. 6095 6096Please note that U-Boot is implemented in C (and to some small parts in 6097Assembler); no C++ is used, so please do not use C++ style comments (//) 6098in your code. 6099 6100Please also stick to the following formatting rules: 6101- remove any trailing white space 6102- use TAB characters for indentation and vertical alignment, not spaces 6103- make sure NOT to use DOS '\r\n' line feeds 6104- do not add more than 2 consecutive empty lines to source files 6105- do not add trailing empty lines to source files 6106 6107Submissions which do not conform to the standards may be returned 6108with a request to reformat the changes. 6109 6110 6111Submitting Patches: 6112------------------- 6113 6114Since the number of patches for U-Boot is growing, we need to 6115establish some rules. Submissions which do not conform to these rules 6116may be rejected, even when they contain important and valuable stuff. 6117 6118Please see http://www.denx.de/wiki/U-Boot/Patches for details. 6119 6120Patches shall be sent to the u-boot mailing list <u-boot@lists.denx.de>; 6121see http://lists.denx.de/mailman/listinfo/u-boot 6122 6123When you send a patch, please include the following information with 6124it: 6125 6126* For bug fixes: a description of the bug and how your patch fixes 6127 this bug. Please try to include a way of demonstrating that the 6128 patch actually fixes something. 6129 6130* For new features: a description of the feature and your 6131 implementation. 6132 6133* A CHANGELOG entry as plaintext (separate from the patch) 6134 6135* For major contributions, add a MAINTAINERS file with your 6136 information and associated file and directory references. 6137 6138* When you add support for a new board, don't forget to add a 6139 maintainer e-mail address to the boards.cfg file, too. 6140 6141* If your patch adds new configuration options, don't forget to 6142 document these in the README file. 6143 6144* The patch itself. If you are using git (which is *strongly* 6145 recommended) you can easily generate the patch using the 6146 "git format-patch". If you then use "git send-email" to send it to 6147 the U-Boot mailing list, you will avoid most of the common problems 6148 with some other mail clients. 6149 6150 If you cannot use git, use "diff -purN OLD NEW". If your version of 6151 diff does not support these options, then get the latest version of 6152 GNU diff. 6153 6154 The current directory when running this command shall be the parent 6155 directory of the U-Boot source tree (i. e. please make sure that 6156 your patch includes sufficient directory information for the 6157 affected files). 6158 6159 We prefer patches as plain text. MIME attachments are discouraged, 6160 and compressed attachments must not be used. 6161 6162* If one logical set of modifications affects or creates several 6163 files, all these changes shall be submitted in a SINGLE patch file. 6164 6165* Changesets that contain different, unrelated modifications shall be 6166 submitted as SEPARATE patches, one patch per changeset. 6167 6168 6169Notes: 6170 6171* Before sending the patch, run the buildman script on your patched 6172 source tree and make sure that no errors or warnings are reported 6173 for any of the boards. 6174 6175* Keep your modifications to the necessary minimum: A patch 6176 containing several unrelated changes or arbitrary reformats will be 6177 returned with a request to re-formatting / split it. 6178 6179* If you modify existing code, make sure that your new code does not 6180 add to the memory footprint of the code ;-) Small is beautiful! 6181 When adding new features, these should compile conditionally only 6182 (using #ifdef), and the resulting code with the new feature 6183 disabled must not need more memory than the old code without your 6184 modification. 6185 6186* Remember that there is a size limit of 100 kB per message on the 6187 u-boot mailing list. Bigger patches will be moderated. If they are 6188 reasonable and not too big, they will be acknowledged. But patches 6189 bigger than the size limit should be avoided. 6190