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_BSP * Board specific commands 827 CONFIG_CMD_BOOTD bootd 828 CONFIG_CMD_BOOTI * ARM64 Linux kernel Image support 829 CONFIG_CMD_CACHE * icache, dcache 830 CONFIG_CMD_CLK * clock command support 831 CONFIG_CMD_CONSOLE coninfo 832 CONFIG_CMD_CRC32 * crc32 833 CONFIG_CMD_DATE * support for RTC, date/time... 834 CONFIG_CMD_DHCP * DHCP support 835 CONFIG_CMD_DIAG * Diagnostics 836 CONFIG_CMD_DS4510 * ds4510 I2C gpio commands 837 CONFIG_CMD_DS4510_INFO * ds4510 I2C info command 838 CONFIG_CMD_DS4510_MEM * ds4510 I2C eeprom/sram commansd 839 CONFIG_CMD_DS4510_RST * ds4510 I2C rst command 840 CONFIG_CMD_DTT * Digital Therm and Thermostat 841 CONFIG_CMD_ECHO echo arguments 842 CONFIG_CMD_EDITENV edit env variable 843 CONFIG_CMD_EEPROM * EEPROM read/write support 844 CONFIG_CMD_EEPROM_LAYOUT* EEPROM layout aware commands 845 CONFIG_CMD_ELF * bootelf, bootvx 846 CONFIG_CMD_ENV_CALLBACK * display details about env callbacks 847 CONFIG_CMD_ENV_FLAGS * display details about env flags 848 CONFIG_CMD_ENV_EXISTS * check existence of env variable 849 CONFIG_CMD_EXPORTENV * export the environment 850 CONFIG_CMD_EXT2 * ext2 command support 851 CONFIG_CMD_EXT4 * ext4 command support 852 CONFIG_CMD_FS_GENERIC * filesystem commands (e.g. load, ls) 853 that work for multiple fs types 854 CONFIG_CMD_FS_UUID * Look up a filesystem UUID 855 CONFIG_CMD_SAVEENV saveenv 856 CONFIG_CMD_FDC * Floppy Disk Support 857 CONFIG_CMD_FAT * FAT command support 858 CONFIG_CMD_FLASH flinfo, erase, protect 859 CONFIG_CMD_FPGA FPGA device initialization support 860 CONFIG_CMD_FUSE * Device fuse support 861 CONFIG_CMD_GETTIME * Get time since boot 862 CONFIG_CMD_GO * the 'go' command (exec code) 863 CONFIG_CMD_GREPENV * search environment 864 CONFIG_CMD_HASH * calculate hash / digest 865 CONFIG_CMD_I2C * I2C serial bus support 866 CONFIG_CMD_IDE * IDE harddisk support 867 CONFIG_CMD_IMI iminfo 868 CONFIG_CMD_IMLS List all images found in NOR flash 869 CONFIG_CMD_IMLS_NAND * List all images found in NAND flash 870 CONFIG_CMD_IMMAP * IMMR dump support 871 CONFIG_CMD_IOTRACE * I/O tracing for debugging 872 CONFIG_CMD_IMPORTENV * import an environment 873 CONFIG_CMD_INI * import data from an ini file into the env 874 CONFIG_CMD_IRQ * irqinfo 875 CONFIG_CMD_ITEST Integer/string test of 2 values 876 CONFIG_CMD_JFFS2 * JFFS2 Support 877 CONFIG_CMD_KGDB * kgdb 878 CONFIG_CMD_LDRINFO * ldrinfo (display Blackfin loader) 879 CONFIG_CMD_LINK_LOCAL * link-local IP address auto-configuration 880 (169.254.*.*) 881 CONFIG_CMD_LOADB loadb 882 CONFIG_CMD_LOADS loads 883 CONFIG_CMD_MD5SUM * print md5 message digest 884 (requires CONFIG_CMD_MEMORY and CONFIG_MD5) 885 CONFIG_CMD_MEMINFO * Display detailed memory information 886 CONFIG_CMD_MEMORY md, mm, nm, mw, cp, cmp, crc, base, 887 loop, loopw 888 CONFIG_CMD_MEMTEST * mtest 889 CONFIG_CMD_MISC Misc functions like sleep etc 890 CONFIG_CMD_MMC * MMC memory mapped support 891 CONFIG_CMD_MII * MII utility commands 892 CONFIG_CMD_MTDPARTS * MTD partition support 893 CONFIG_CMD_NAND * NAND support 894 CONFIG_CMD_NET bootp, tftpboot, rarpboot 895 CONFIG_CMD_NFS NFS support 896 CONFIG_CMD_PCA953X * PCA953x I2C gpio commands 897 CONFIG_CMD_PCA953X_INFO * PCA953x I2C gpio info command 898 CONFIG_CMD_PCI * pciinfo 899 CONFIG_CMD_PCMCIA * PCMCIA support 900 CONFIG_CMD_PING * send ICMP ECHO_REQUEST to network 901 host 902 CONFIG_CMD_PORTIO * Port I/O 903 CONFIG_CMD_READ * Read raw data from partition 904 CONFIG_CMD_REGINFO * Register dump 905 CONFIG_CMD_RUN run command in env variable 906 CONFIG_CMD_SANDBOX * sb command to access sandbox features 907 CONFIG_CMD_SAVES * save S record dump 908 CONFIG_SCSI * SCSI Support 909 CONFIG_CMD_SDRAM * print SDRAM configuration information 910 (requires CONFIG_CMD_I2C) 911 CONFIG_CMD_SETGETDCR Support for DCR Register access 912 (4xx only) 913 CONFIG_CMD_SF * Read/write/erase SPI NOR flash 914 CONFIG_CMD_SHA1SUM * print sha1 memory digest 915 (requires CONFIG_CMD_MEMORY) 916 CONFIG_CMD_SOFTSWITCH * Soft switch setting command for BF60x 917 CONFIG_CMD_SOURCE "source" command Support 918 CONFIG_CMD_SPI * SPI serial bus support 919 CONFIG_CMD_TFTPSRV * TFTP transfer in server mode 920 CONFIG_CMD_TFTPPUT * TFTP put command (upload) 921 CONFIG_CMD_TIME * run command and report execution time (ARM specific) 922 CONFIG_CMD_TIMER * access to the system tick timer 923 CONFIG_CMD_USB * USB support 924 CONFIG_CMD_CDP * Cisco Discover Protocol support 925 CONFIG_CMD_MFSL * Microblaze FSL support 926 CONFIG_CMD_XIMG Load part of Multi Image 927 CONFIG_CMD_UUID * Generate random UUID or GUID string 928 929 EXAMPLE: If you want all functions except of network 930 support you can write: 931 932 #include "config_cmd_all.h" 933 #undef CONFIG_CMD_NET 934 935 Other Commands: 936 fdt (flattened device tree) command: CONFIG_OF_LIBFDT 937 938 Note: Don't enable the "icache" and "dcache" commands 939 (configuration option CONFIG_CMD_CACHE) unless you know 940 what you (and your U-Boot users) are doing. Data 941 cache cannot be enabled on systems like the 8xx or 942 8260 (where accesses to the IMMR region must be 943 uncached), and it cannot be disabled on all other 944 systems where we (mis-) use the data cache to hold an 945 initial stack and some data. 946 947 948 XXX - this list needs to get updated! 949 950- Removal of commands 951 If no commands are needed to boot, you can disable 952 CONFIG_CMDLINE to remove them. In this case, the command line 953 will not be available, and when U-Boot wants to execute the 954 boot command (on start-up) it will call board_run_command() 955 instead. This can reduce image size significantly for very 956 simple boot procedures. 957 958- Regular expression support: 959 CONFIG_REGEX 960 If this variable is defined, U-Boot is linked against 961 the SLRE (Super Light Regular Expression) library, 962 which adds regex support to some commands, as for 963 example "env grep" and "setexpr". 964 965- Device tree: 966 CONFIG_OF_CONTROL 967 If this variable is defined, U-Boot will use a device tree 968 to configure its devices, instead of relying on statically 969 compiled #defines in the board file. This option is 970 experimental and only available on a few boards. The device 971 tree is available in the global data as gd->fdt_blob. 972 973 U-Boot needs to get its device tree from somewhere. This can 974 be done using one of the two options below: 975 976 CONFIG_OF_EMBED 977 If this variable is defined, U-Boot will embed a device tree 978 binary in its image. This device tree file should be in the 979 board directory and called <soc>-<board>.dts. The binary file 980 is then picked up in board_init_f() and made available through 981 the global data structure as gd->blob. 982 983 CONFIG_OF_SEPARATE 984 If this variable is defined, U-Boot will build a device tree 985 binary. It will be called u-boot.dtb. Architecture-specific 986 code will locate it at run-time. Generally this works by: 987 988 cat u-boot.bin u-boot.dtb >image.bin 989 990 and in fact, U-Boot does this for you, creating a file called 991 u-boot-dtb.bin which is useful in the common case. You can 992 still use the individual files if you need something more 993 exotic. 994 995- Watchdog: 996 CONFIG_WATCHDOG 997 If this variable is defined, it enables watchdog 998 support for the SoC. There must be support in the SoC 999 specific code for a watchdog. For the 8xx and 8260 1000 CPUs, the SIU Watchdog feature is enabled in the SYPCR 1001 register. When supported for a specific SoC is 1002 available, then no further board specific code should 1003 be needed to use it. 1004 1005 CONFIG_HW_WATCHDOG 1006 When using a watchdog circuitry external to the used 1007 SoC, then define this variable and provide board 1008 specific code for the "hw_watchdog_reset" function. 1009 1010 CONFIG_AT91_HW_WDT_TIMEOUT 1011 specify the timeout in seconds. default 2 seconds. 1012 1013- U-Boot Version: 1014 CONFIG_VERSION_VARIABLE 1015 If this variable is defined, an environment variable 1016 named "ver" is created by U-Boot showing the U-Boot 1017 version as printed by the "version" command. 1018 Any change to this variable will be reverted at the 1019 next reset. 1020 1021- Real-Time Clock: 1022 1023 When CONFIG_CMD_DATE is selected, the type of the RTC 1024 has to be selected, too. Define exactly one of the 1025 following options: 1026 1027 CONFIG_RTC_MPC8xx - use internal RTC of MPC8xx 1028 CONFIG_RTC_PCF8563 - use Philips PCF8563 RTC 1029 CONFIG_RTC_MC13XXX - use MC13783 or MC13892 RTC 1030 CONFIG_RTC_MC146818 - use MC146818 RTC 1031 CONFIG_RTC_DS1307 - use Maxim, Inc. DS1307 RTC 1032 CONFIG_RTC_DS1337 - use Maxim, Inc. DS1337 RTC 1033 CONFIG_RTC_DS1338 - use Maxim, Inc. DS1338 RTC 1034 CONFIG_RTC_DS1339 - use Maxim, Inc. DS1339 RTC 1035 CONFIG_RTC_DS164x - use Dallas DS164x RTC 1036 CONFIG_RTC_ISL1208 - use Intersil ISL1208 RTC 1037 CONFIG_RTC_MAX6900 - use Maxim, Inc. MAX6900 RTC 1038 CONFIG_SYS_RTC_DS1337_NOOSC - Turn off the OSC output for DS1337 1039 CONFIG_SYS_RV3029_TCR - enable trickle charger on 1040 RV3029 RTC. 1041 1042 Note that if the RTC uses I2C, then the I2C interface 1043 must also be configured. See I2C Support, below. 1044 1045- GPIO Support: 1046 CONFIG_PCA953X - use NXP's PCA953X series I2C GPIO 1047 1048 The CONFIG_SYS_I2C_PCA953X_WIDTH option specifies a list of 1049 chip-ngpio pairs that tell the PCA953X driver the number of 1050 pins supported by a particular chip. 1051 1052 Note that if the GPIO device uses I2C, then the I2C interface 1053 must also be configured. See I2C Support, below. 1054 1055- I/O tracing: 1056 When CONFIG_IO_TRACE is selected, U-Boot intercepts all I/O 1057 accesses and can checksum them or write a list of them out 1058 to memory. See the 'iotrace' command for details. This is 1059 useful for testing device drivers since it can confirm that 1060 the driver behaves the same way before and after a code 1061 change. Currently this is supported on sandbox and arm. To 1062 add support for your architecture, add '#include <iotrace.h>' 1063 to the bottom of arch/<arch>/include/asm/io.h and test. 1064 1065 Example output from the 'iotrace stats' command is below. 1066 Note that if the trace buffer is exhausted, the checksum will 1067 still continue to operate. 1068 1069 iotrace is enabled 1070 Start: 10000000 (buffer start address) 1071 Size: 00010000 (buffer size) 1072 Offset: 00000120 (current buffer offset) 1073 Output: 10000120 (start + offset) 1074 Count: 00000018 (number of trace records) 1075 CRC32: 9526fb66 (CRC32 of all trace records) 1076 1077- Timestamp Support: 1078 1079 When CONFIG_TIMESTAMP is selected, the timestamp 1080 (date and time) of an image is printed by image 1081 commands like bootm or iminfo. This option is 1082 automatically enabled when you select CONFIG_CMD_DATE . 1083 1084- Partition Labels (disklabels) Supported: 1085 Zero or more of the following: 1086 CONFIG_MAC_PARTITION Apple's MacOS partition table. 1087 CONFIG_DOS_PARTITION MS Dos partition table, traditional on the 1088 Intel architecture, USB sticks, etc. 1089 CONFIG_ISO_PARTITION ISO partition table, used on CDROM etc. 1090 CONFIG_EFI_PARTITION GPT partition table, common when EFI is the 1091 bootloader. Note 2TB partition limit; see 1092 disk/part_efi.c 1093 CONFIG_MTD_PARTITIONS Memory Technology Device partition table. 1094 1095 If IDE or SCSI support is enabled (CONFIG_CMD_IDE or 1096 CONFIG_SCSI) you must configure support for at 1097 least one non-MTD partition type as well. 1098 1099- IDE Reset method: 1100 CONFIG_IDE_RESET_ROUTINE - this is defined in several 1101 board configurations files but used nowhere! 1102 1103 CONFIG_IDE_RESET - is this is defined, IDE Reset will 1104 be performed by calling the function 1105 ide_set_reset(int reset) 1106 which has to be defined in a board specific file 1107 1108- ATAPI Support: 1109 CONFIG_ATAPI 1110 1111 Set this to enable ATAPI support. 1112 1113- LBA48 Support 1114 CONFIG_LBA48 1115 1116 Set this to enable support for disks larger than 137GB 1117 Also look at CONFIG_SYS_64BIT_LBA. 1118 Whithout these , LBA48 support uses 32bit variables and will 'only' 1119 support disks up to 2.1TB. 1120 1121 CONFIG_SYS_64BIT_LBA: 1122 When enabled, makes the IDE subsystem use 64bit sector addresses. 1123 Default is 32bit. 1124 1125- SCSI Support: 1126 At the moment only there is only support for the 1127 SYM53C8XX SCSI controller; define 1128 CONFIG_SCSI_SYM53C8XX to enable it. 1129 1130 CONFIG_SYS_SCSI_MAX_LUN [8], CONFIG_SYS_SCSI_MAX_SCSI_ID [7] and 1131 CONFIG_SYS_SCSI_MAX_DEVICE [CONFIG_SYS_SCSI_MAX_SCSI_ID * 1132 CONFIG_SYS_SCSI_MAX_LUN] can be adjusted to define the 1133 maximum numbers of LUNs, SCSI ID's and target 1134 devices. 1135 CONFIG_SYS_SCSI_SYM53C8XX_CCF to fix clock timing (80Mhz) 1136 1137 The environment variable 'scsidevs' is set to the number of 1138 SCSI devices found during the last scan. 1139 1140- NETWORK Support (PCI): 1141 CONFIG_E1000 1142 Support for Intel 8254x/8257x gigabit chips. 1143 1144 CONFIG_E1000_SPI 1145 Utility code for direct access to the SPI bus on Intel 8257x. 1146 This does not do anything useful unless you set at least one 1147 of CONFIG_CMD_E1000 or CONFIG_E1000_SPI_GENERIC. 1148 1149 CONFIG_E1000_SPI_GENERIC 1150 Allow generic access to the SPI bus on the Intel 8257x, for 1151 example with the "sspi" command. 1152 1153 CONFIG_CMD_E1000 1154 Management command for E1000 devices. When used on devices 1155 with SPI support you can reprogram the EEPROM from U-Boot. 1156 1157 CONFIG_EEPRO100 1158 Support for Intel 82557/82559/82559ER chips. 1159 Optional CONFIG_EEPRO100_SROM_WRITE enables EEPROM 1160 write routine for first time initialisation. 1161 1162 CONFIG_TULIP 1163 Support for Digital 2114x chips. 1164 Optional CONFIG_TULIP_SELECT_MEDIA for board specific 1165 modem chip initialisation (KS8761/QS6611). 1166 1167 CONFIG_NATSEMI 1168 Support for National dp83815 chips. 1169 1170 CONFIG_NS8382X 1171 Support for National dp8382[01] gigabit chips. 1172 1173- NETWORK Support (other): 1174 1175 CONFIG_DRIVER_AT91EMAC 1176 Support for AT91RM9200 EMAC. 1177 1178 CONFIG_RMII 1179 Define this to use reduced MII inteface 1180 1181 CONFIG_DRIVER_AT91EMAC_QUIET 1182 If this defined, the driver is quiet. 1183 The driver doen't show link status messages. 1184 1185 CONFIG_CALXEDA_XGMAC 1186 Support for the Calxeda XGMAC device 1187 1188 CONFIG_LAN91C96 1189 Support for SMSC's LAN91C96 chips. 1190 1191 CONFIG_LAN91C96_USE_32_BIT 1192 Define this to enable 32 bit addressing 1193 1194 CONFIG_SMC91111 1195 Support for SMSC's LAN91C111 chip 1196 1197 CONFIG_SMC91111_BASE 1198 Define this to hold the physical address 1199 of the device (I/O space) 1200 1201 CONFIG_SMC_USE_32_BIT 1202 Define this if data bus is 32 bits 1203 1204 CONFIG_SMC_USE_IOFUNCS 1205 Define this to use i/o functions instead of macros 1206 (some hardware wont work with macros) 1207 1208 CONFIG_DRIVER_TI_EMAC 1209 Support for davinci emac 1210 1211 CONFIG_SYS_DAVINCI_EMAC_PHY_COUNT 1212 Define this if you have more then 3 PHYs. 1213 1214 CONFIG_FTGMAC100 1215 Support for Faraday's FTGMAC100 Gigabit SoC Ethernet 1216 1217 CONFIG_FTGMAC100_EGIGA 1218 Define this to use GE link update with gigabit PHY. 1219 Define this if FTGMAC100 is connected to gigabit PHY. 1220 If your system has 10/100 PHY only, it might not occur 1221 wrong behavior. Because PHY usually return timeout or 1222 useless data when polling gigabit status and gigabit 1223 control registers. This behavior won't affect the 1224 correctnessof 10/100 link speed update. 1225 1226 CONFIG_SMC911X 1227 Support for SMSC's LAN911x and LAN921x chips 1228 1229 CONFIG_SMC911X_BASE 1230 Define this to hold the physical address 1231 of the device (I/O space) 1232 1233 CONFIG_SMC911X_32_BIT 1234 Define this if data bus is 32 bits 1235 1236 CONFIG_SMC911X_16_BIT 1237 Define this if data bus is 16 bits. If your processor 1238 automatically converts one 32 bit word to two 16 bit 1239 words you may also try CONFIG_SMC911X_32_BIT. 1240 1241 CONFIG_SH_ETHER 1242 Support for Renesas on-chip Ethernet controller 1243 1244 CONFIG_SH_ETHER_USE_PORT 1245 Define the number of ports to be used 1246 1247 CONFIG_SH_ETHER_PHY_ADDR 1248 Define the ETH PHY's address 1249 1250 CONFIG_SH_ETHER_CACHE_WRITEBACK 1251 If this option is set, the driver enables cache flush. 1252 1253- PWM Support: 1254 CONFIG_PWM_IMX 1255 Support for PWM module on the imx6. 1256 1257- TPM Support: 1258 CONFIG_TPM 1259 Support TPM devices. 1260 1261 CONFIG_TPM_TIS_INFINEON 1262 Support for Infineon i2c bus TPM devices. Only one device 1263 per system is supported at this time. 1264 1265 CONFIG_TPM_TIS_I2C_BURST_LIMITATION 1266 Define the burst count bytes upper limit 1267 1268 CONFIG_TPM_ST33ZP24 1269 Support for STMicroelectronics TPM devices. Requires DM_TPM support. 1270 1271 CONFIG_TPM_ST33ZP24_I2C 1272 Support for STMicroelectronics ST33ZP24 I2C devices. 1273 Requires TPM_ST33ZP24 and I2C. 1274 1275 CONFIG_TPM_ST33ZP24_SPI 1276 Support for STMicroelectronics ST33ZP24 SPI devices. 1277 Requires TPM_ST33ZP24 and SPI. 1278 1279 CONFIG_TPM_ATMEL_TWI 1280 Support for Atmel TWI TPM device. Requires I2C support. 1281 1282 CONFIG_TPM_TIS_LPC 1283 Support for generic parallel port TPM devices. Only one device 1284 per system is supported at this time. 1285 1286 CONFIG_TPM_TIS_BASE_ADDRESS 1287 Base address where the generic TPM device is mapped 1288 to. Contemporary x86 systems usually map it at 1289 0xfed40000. 1290 1291 CONFIG_CMD_TPM 1292 Add tpm monitor functions. 1293 Requires CONFIG_TPM. If CONFIG_TPM_AUTH_SESSIONS is set, also 1294 provides monitor access to authorized functions. 1295 1296 CONFIG_TPM 1297 Define this to enable the TPM support library which provides 1298 functional interfaces to some TPM commands. 1299 Requires support for a TPM device. 1300 1301 CONFIG_TPM_AUTH_SESSIONS 1302 Define this to enable authorized functions in the TPM library. 1303 Requires CONFIG_TPM and CONFIG_SHA1. 1304 1305- USB Support: 1306 At the moment only the UHCI host controller is 1307 supported (PIP405, MIP405, MPC5200); define 1308 CONFIG_USB_UHCI to enable it. 1309 define CONFIG_USB_KEYBOARD to enable the USB Keyboard 1310 and define CONFIG_USB_STORAGE to enable the USB 1311 storage devices. 1312 Note: 1313 Supported are USB Keyboards and USB Floppy drives 1314 (TEAC FD-05PUB). 1315 MPC5200 USB requires additional defines: 1316 CONFIG_USB_CLOCK 1317 for 528 MHz Clock: 0x0001bbbb 1318 CONFIG_PSC3_USB 1319 for USB on PSC3 1320 CONFIG_USB_CONFIG 1321 for differential drivers: 0x00001000 1322 for single ended drivers: 0x00005000 1323 for differential drivers on PSC3: 0x00000100 1324 for single ended drivers on PSC3: 0x00004100 1325 CONFIG_SYS_USB_EVENT_POLL 1326 May be defined to allow interrupt polling 1327 instead of using asynchronous interrupts 1328 1329 CONFIG_USB_EHCI_TXFIFO_THRESH enables setting of the 1330 txfilltuning field in the EHCI controller on reset. 1331 1332 CONFIG_USB_DWC2_REG_ADDR the physical CPU address of the DWC2 1333 HW module registers. 1334 1335- USB Device: 1336 Define the below if you wish to use the USB console. 1337 Once firmware is rebuilt from a serial console issue the 1338 command "setenv stdin usbtty; setenv stdout usbtty" and 1339 attach your USB cable. The Unix command "dmesg" should print 1340 it has found a new device. The environment variable usbtty 1341 can be set to gserial or cdc_acm to enable your device to 1342 appear to a USB host as a Linux gserial device or a 1343 Common Device Class Abstract Control Model serial device. 1344 If you select usbtty = gserial you should be able to enumerate 1345 a Linux host by 1346 # modprobe usbserial vendor=0xVendorID product=0xProductID 1347 else if using cdc_acm, simply setting the environment 1348 variable usbtty to be cdc_acm should suffice. The following 1349 might be defined in YourBoardName.h 1350 1351 CONFIG_USB_DEVICE 1352 Define this to build a UDC device 1353 1354 CONFIG_USB_TTY 1355 Define this to have a tty type of device available to 1356 talk to the UDC device 1357 1358 CONFIG_USBD_HS 1359 Define this to enable the high speed support for usb 1360 device and usbtty. If this feature is enabled, a routine 1361 int is_usbd_high_speed(void) 1362 also needs to be defined by the driver to dynamically poll 1363 whether the enumeration has succeded at high speed or full 1364 speed. 1365 1366 CONFIG_SYS_CONSOLE_IS_IN_ENV 1367 Define this if you want stdin, stdout &/or stderr to 1368 be set to usbtty. 1369 1370 mpc8xx: 1371 CONFIG_SYS_USB_EXTC_CLK 0xBLAH 1372 Derive USB clock from external clock "blah" 1373 - CONFIG_SYS_USB_EXTC_CLK 0x02 1374 1375 If you have a USB-IF assigned VendorID then you may wish to 1376 define your own vendor specific values either in BoardName.h 1377 or directly in usbd_vendor_info.h. If you don't define 1378 CONFIG_USBD_MANUFACTURER, CONFIG_USBD_PRODUCT_NAME, 1379 CONFIG_USBD_VENDORID and CONFIG_USBD_PRODUCTID, then U-Boot 1380 should pretend to be a Linux device to it's target host. 1381 1382 CONFIG_USBD_MANUFACTURER 1383 Define this string as the name of your company for 1384 - CONFIG_USBD_MANUFACTURER "my company" 1385 1386 CONFIG_USBD_PRODUCT_NAME 1387 Define this string as the name of your product 1388 - CONFIG_USBD_PRODUCT_NAME "acme usb device" 1389 1390 CONFIG_USBD_VENDORID 1391 Define this as your assigned Vendor ID from the USB 1392 Implementors Forum. This *must* be a genuine Vendor ID 1393 to avoid polluting the USB namespace. 1394 - CONFIG_USBD_VENDORID 0xFFFF 1395 1396 CONFIG_USBD_PRODUCTID 1397 Define this as the unique Product ID 1398 for your device 1399 - CONFIG_USBD_PRODUCTID 0xFFFF 1400 1401- ULPI Layer Support: 1402 The ULPI (UTMI Low Pin (count) Interface) PHYs are supported via 1403 the generic ULPI layer. The generic layer accesses the ULPI PHY 1404 via the platform viewport, so you need both the genric layer and 1405 the viewport enabled. Currently only Chipidea/ARC based 1406 viewport is supported. 1407 To enable the ULPI layer support, define CONFIG_USB_ULPI and 1408 CONFIG_USB_ULPI_VIEWPORT in your board configuration file. 1409 If your ULPI phy needs a different reference clock than the 1410 standard 24 MHz then you have to define CONFIG_ULPI_REF_CLK to 1411 the appropriate value in Hz. 1412 1413- MMC Support: 1414 The MMC controller on the Intel PXA is supported. To 1415 enable this define CONFIG_MMC. The MMC can be 1416 accessed from the boot prompt by mapping the device 1417 to physical memory similar to flash. Command line is 1418 enabled with CONFIG_CMD_MMC. The MMC driver also works with 1419 the FAT fs. This is enabled with CONFIG_CMD_FAT. 1420 1421 CONFIG_SH_MMCIF 1422 Support for Renesas on-chip MMCIF controller 1423 1424 CONFIG_SH_MMCIF_ADDR 1425 Define the base address of MMCIF registers 1426 1427 CONFIG_SH_MMCIF_CLK 1428 Define the clock frequency for MMCIF 1429 1430 CONFIG_SUPPORT_EMMC_BOOT 1431 Enable some additional features of the eMMC boot partitions. 1432 1433 CONFIG_SUPPORT_EMMC_RPMB 1434 Enable the commands for reading, writing and programming the 1435 key for the Replay Protection Memory Block partition in eMMC. 1436 1437- USB Device Firmware Update (DFU) class support: 1438 CONFIG_USB_FUNCTION_DFU 1439 This enables the USB portion of the DFU USB class 1440 1441 CONFIG_CMD_DFU 1442 This enables the command "dfu" which is used to have 1443 U-Boot create a DFU class device via USB. This command 1444 requires that the "dfu_alt_info" environment variable be 1445 set and define the alt settings to expose to the host. 1446 1447 CONFIG_DFU_MMC 1448 This enables support for exposing (e)MMC devices via DFU. 1449 1450 CONFIG_DFU_NAND 1451 This enables support for exposing NAND devices via DFU. 1452 1453 CONFIG_DFU_RAM 1454 This enables support for exposing RAM via DFU. 1455 Note: DFU spec refer to non-volatile memory usage, but 1456 allow usages beyond the scope of spec - here RAM usage, 1457 one that would help mostly the developer. 1458 1459 CONFIG_SYS_DFU_DATA_BUF_SIZE 1460 Dfu transfer uses a buffer before writing data to the 1461 raw storage device. Make the size (in bytes) of this buffer 1462 configurable. The size of this buffer is also configurable 1463 through the "dfu_bufsiz" environment variable. 1464 1465 CONFIG_SYS_DFU_MAX_FILE_SIZE 1466 When updating files rather than the raw storage device, 1467 we use a static buffer to copy the file into and then write 1468 the buffer once we've been given the whole file. Define 1469 this to the maximum filesize (in bytes) for the buffer. 1470 Default is 4 MiB if undefined. 1471 1472 DFU_DEFAULT_POLL_TIMEOUT 1473 Poll timeout [ms], is the timeout a device can send to the 1474 host. The host must wait for this timeout before sending 1475 a subsequent DFU_GET_STATUS request to the device. 1476 1477 DFU_MANIFEST_POLL_TIMEOUT 1478 Poll timeout [ms], which the device sends to the host when 1479 entering dfuMANIFEST state. Host waits this timeout, before 1480 sending again an USB request to the device. 1481 1482- USB Device Android Fastboot support: 1483 CONFIG_USB_FUNCTION_FASTBOOT 1484 This enables the USB part of the fastboot gadget 1485 1486 CONFIG_CMD_FASTBOOT 1487 This enables the command "fastboot" which enables the Android 1488 fastboot mode for the platform's USB device. Fastboot is a USB 1489 protocol for downloading images, flashing and device control 1490 used on Android devices. 1491 See doc/README.android-fastboot for more information. 1492 1493 CONFIG_ANDROID_BOOT_IMAGE 1494 This enables support for booting images which use the Android 1495 image format header. 1496 1497 CONFIG_FASTBOOT_BUF_ADDR 1498 The fastboot protocol requires a large memory buffer for 1499 downloads. Define this to the starting RAM address to use for 1500 downloaded images. 1501 1502 CONFIG_FASTBOOT_BUF_SIZE 1503 The fastboot protocol requires a large memory buffer for 1504 downloads. This buffer should be as large as possible for a 1505 platform. Define this to the size available RAM for fastboot. 1506 1507 CONFIG_FASTBOOT_FLASH 1508 The fastboot protocol includes a "flash" command for writing 1509 the downloaded image to a non-volatile storage device. Define 1510 this to enable the "fastboot flash" command. 1511 1512 CONFIG_FASTBOOT_FLASH_MMC_DEV 1513 The fastboot "flash" command requires additional information 1514 regarding the non-volatile storage device. Define this to 1515 the eMMC device that fastboot should use to store the image. 1516 1517 CONFIG_FASTBOOT_GPT_NAME 1518 The fastboot "flash" command supports writing the downloaded 1519 image to the Protective MBR and the Primary GUID Partition 1520 Table. (Additionally, this downloaded image is post-processed 1521 to generate and write the Backup GUID Partition Table.) 1522 This occurs when the specified "partition name" on the 1523 "fastboot flash" command line matches this value. 1524 The default is "gpt" if undefined. 1525 1526 CONFIG_FASTBOOT_MBR_NAME 1527 The fastboot "flash" command supports writing the downloaded 1528 image to DOS MBR. 1529 This occurs when the "partition name" specified on the 1530 "fastboot flash" command line matches this value. 1531 If not defined the default value "mbr" is used. 1532 1533- Journaling Flash filesystem support: 1534 CONFIG_JFFS2_NAND 1535 Define these for a default partition on a NAND device 1536 1537 CONFIG_SYS_JFFS2_FIRST_SECTOR, 1538 CONFIG_SYS_JFFS2_FIRST_BANK, CONFIG_SYS_JFFS2_NUM_BANKS 1539 Define these for a default partition on a NOR device 1540 1541- FAT(File Allocation Table) filesystem write function support: 1542 CONFIG_FAT_WRITE 1543 1544 Define this to enable support for saving memory data as a 1545 file in FAT formatted partition. 1546 1547 This will also enable the command "fatwrite" enabling the 1548 user to write files to FAT. 1549 1550- CBFS (Coreboot Filesystem) support: 1551 CONFIG_CMD_CBFS 1552 1553 Define this to enable support for reading from a Coreboot 1554 filesystem. Available commands are cbfsinit, cbfsinfo, cbfsls 1555 and cbfsload. 1556 1557- FAT(File Allocation Table) filesystem cluster size: 1558 CONFIG_FS_FAT_MAX_CLUSTSIZE 1559 1560 Define the max cluster size for fat operations else 1561 a default value of 65536 will be defined. 1562 1563- Keyboard Support: 1564 See Kconfig help for available keyboard drivers. 1565 1566 CONFIG_KEYBOARD 1567 1568 Define this to enable a custom keyboard support. 1569 This simply calls drv_keyboard_init() which must be 1570 defined in your board-specific files. This option is deprecated 1571 and is only used by novena. For new boards, use driver model 1572 instead. 1573 1574- Video support: 1575 CONFIG_FSL_DIU_FB 1576 Enable the Freescale DIU video driver. Reference boards for 1577 SOCs that have a DIU should define this macro to enable DIU 1578 support, and should also define these other macros: 1579 1580 CONFIG_SYS_DIU_ADDR 1581 CONFIG_VIDEO 1582 CONFIG_CMD_BMP 1583 CONFIG_CFB_CONSOLE 1584 CONFIG_VIDEO_SW_CURSOR 1585 CONFIG_VGA_AS_SINGLE_DEVICE 1586 CONFIG_VIDEO_LOGO 1587 CONFIG_VIDEO_BMP_LOGO 1588 1589 The DIU driver will look for the 'video-mode' environment 1590 variable, and if defined, enable the DIU as a console during 1591 boot. See the documentation file doc/README.video for a 1592 description of this variable. 1593 1594- LCD Support: CONFIG_LCD 1595 1596 Define this to enable LCD support (for output to LCD 1597 display); also select one of the supported displays 1598 by defining one of these: 1599 1600 CONFIG_ATMEL_LCD: 1601 1602 HITACHI TX09D70VM1CCA, 3.5", 240x320. 1603 1604 CONFIG_NEC_NL6448AC33: 1605 1606 NEC NL6448AC33-18. Active, color, single scan. 1607 1608 CONFIG_NEC_NL6448BC20 1609 1610 NEC NL6448BC20-08. 6.5", 640x480. 1611 Active, color, single scan. 1612 1613 CONFIG_NEC_NL6448BC33_54 1614 1615 NEC NL6448BC33-54. 10.4", 640x480. 1616 Active, color, single scan. 1617 1618 CONFIG_SHARP_16x9 1619 1620 Sharp 320x240. Active, color, single scan. 1621 It isn't 16x9, and I am not sure what it is. 1622 1623 CONFIG_SHARP_LQ64D341 1624 1625 Sharp LQ64D341 display, 640x480. 1626 Active, color, single scan. 1627 1628 CONFIG_HLD1045 1629 1630 HLD1045 display, 640x480. 1631 Active, color, single scan. 1632 1633 CONFIG_OPTREX_BW 1634 1635 Optrex CBL50840-2 NF-FW 99 22 M5 1636 or 1637 Hitachi LMG6912RPFC-00T 1638 or 1639 Hitachi SP14Q002 1640 1641 320x240. Black & white. 1642 1643 Normally display is black on white background; define 1644 CONFIG_SYS_WHITE_ON_BLACK to get it inverted. 1645 1646 CONFIG_LCD_ALIGNMENT 1647 1648 Normally the LCD is page-aligned (typically 4KB). If this is 1649 defined then the LCD will be aligned to this value instead. 1650 For ARM it is sometimes useful to use MMU_SECTION_SIZE 1651 here, since it is cheaper to change data cache settings on 1652 a per-section basis. 1653 1654 1655 CONFIG_LCD_ROTATION 1656 1657 Sometimes, for example if the display is mounted in portrait 1658 mode or even if it's mounted landscape but rotated by 180degree, 1659 we need to rotate our content of the display relative to the 1660 framebuffer, so that user can read the messages which are 1661 printed out. 1662 Once CONFIG_LCD_ROTATION is defined, the lcd_console will be 1663 initialized with a given rotation from "vl_rot" out of 1664 "vidinfo_t" which is provided by the board specific code. 1665 The value for vl_rot is coded as following (matching to 1666 fbcon=rotate:<n> linux-kernel commandline): 1667 0 = no rotation respectively 0 degree 1668 1 = 90 degree rotation 1669 2 = 180 degree rotation 1670 3 = 270 degree rotation 1671 1672 If CONFIG_LCD_ROTATION is not defined, the console will be 1673 initialized with 0degree rotation. 1674 1675 CONFIG_LCD_BMP_RLE8 1676 1677 Support drawing of RLE8-compressed bitmaps on the LCD. 1678 1679 CONFIG_I2C_EDID 1680 1681 Enables an 'i2c edid' command which can read EDID 1682 information over I2C from an attached LCD display. 1683 1684- Splash Screen Support: CONFIG_SPLASH_SCREEN 1685 1686 If this option is set, the environment is checked for 1687 a variable "splashimage". If found, the usual display 1688 of logo, copyright and system information on the LCD 1689 is suppressed and the BMP image at the address 1690 specified in "splashimage" is loaded instead. The 1691 console is redirected to the "nulldev", too. This 1692 allows for a "silent" boot where a splash screen is 1693 loaded very quickly after power-on. 1694 1695 CONFIG_SPLASHIMAGE_GUARD 1696 1697 If this option is set, then U-Boot will prevent the environment 1698 variable "splashimage" from being set to a problematic address 1699 (see doc/README.displaying-bmps). 1700 This option is useful for targets where, due to alignment 1701 restrictions, an improperly aligned BMP image will cause a data 1702 abort. If you think you will not have problems with unaligned 1703 accesses (for example because your toolchain prevents them) 1704 there is no need to set this option. 1705 1706 CONFIG_SPLASH_SCREEN_ALIGN 1707 1708 If this option is set the splash image can be freely positioned 1709 on the screen. Environment variable "splashpos" specifies the 1710 position as "x,y". If a positive number is given it is used as 1711 number of pixel from left/top. If a negative number is given it 1712 is used as number of pixel from right/bottom. You can also 1713 specify 'm' for centering the image. 1714 1715 Example: 1716 setenv splashpos m,m 1717 => image at center of screen 1718 1719 setenv splashpos 30,20 1720 => image at x = 30 and y = 20 1721 1722 setenv splashpos -10,m 1723 => vertically centered image 1724 at x = dspWidth - bmpWidth - 9 1725 1726- Gzip compressed BMP image support: CONFIG_VIDEO_BMP_GZIP 1727 1728 If this option is set, additionally to standard BMP 1729 images, gzipped BMP images can be displayed via the 1730 splashscreen support or the bmp command. 1731 1732- Run length encoded BMP image (RLE8) support: CONFIG_VIDEO_BMP_RLE8 1733 1734 If this option is set, 8-bit RLE compressed BMP images 1735 can be displayed via the splashscreen support or the 1736 bmp command. 1737 1738- Compression support: 1739 CONFIG_GZIP 1740 1741 Enabled by default to support gzip compressed images. 1742 1743 CONFIG_BZIP2 1744 1745 If this option is set, support for bzip2 compressed 1746 images is included. If not, only uncompressed and gzip 1747 compressed images are supported. 1748 1749 NOTE: the bzip2 algorithm requires a lot of RAM, so 1750 the malloc area (as defined by CONFIG_SYS_MALLOC_LEN) should 1751 be at least 4MB. 1752 1753 CONFIG_LZMA 1754 1755 If this option is set, support for lzma compressed 1756 images is included. 1757 1758 Note: The LZMA algorithm adds between 2 and 4KB of code and it 1759 requires an amount of dynamic memory that is given by the 1760 formula: 1761 1762 (1846 + 768 << (lc + lp)) * sizeof(uint16) 1763 1764 Where lc and lp stand for, respectively, Literal context bits 1765 and Literal pos bits. 1766 1767 This value is upper-bounded by 14MB in the worst case. Anyway, 1768 for a ~4MB large kernel image, we have lc=3 and lp=0 for a 1769 total amount of (1846 + 768 << (3 + 0)) * 2 = ~41KB... that is 1770 a very small buffer. 1771 1772 Use the lzmainfo tool to determinate the lc and lp values and 1773 then calculate the amount of needed dynamic memory (ensuring 1774 the appropriate CONFIG_SYS_MALLOC_LEN value). 1775 1776 CONFIG_LZO 1777 1778 If this option is set, support for LZO compressed images 1779 is included. 1780 1781- MII/PHY support: 1782 CONFIG_PHY_ADDR 1783 1784 The address of PHY on MII bus. 1785 1786 CONFIG_PHY_CLOCK_FREQ (ppc4xx) 1787 1788 The clock frequency of the MII bus 1789 1790 CONFIG_PHY_GIGE 1791 1792 If this option is set, support for speed/duplex 1793 detection of gigabit PHY is included. 1794 1795 CONFIG_PHY_RESET_DELAY 1796 1797 Some PHY like Intel LXT971A need extra delay after 1798 reset before any MII register access is possible. 1799 For such PHY, set this option to the usec delay 1800 required. (minimum 300usec for LXT971A) 1801 1802 CONFIG_PHY_CMD_DELAY (ppc4xx) 1803 1804 Some PHY like Intel LXT971A need extra delay after 1805 command issued before MII status register can be read 1806 1807- IP address: 1808 CONFIG_IPADDR 1809 1810 Define a default value for the IP address to use for 1811 the default Ethernet interface, in case this is not 1812 determined through e.g. bootp. 1813 (Environment variable "ipaddr") 1814 1815- Server IP address: 1816 CONFIG_SERVERIP 1817 1818 Defines a default value for the IP address of a TFTP 1819 server to contact when using the "tftboot" command. 1820 (Environment variable "serverip") 1821 1822 CONFIG_KEEP_SERVERADDR 1823 1824 Keeps the server's MAC address, in the env 'serveraddr' 1825 for passing to bootargs (like Linux's netconsole option) 1826 1827- Gateway IP address: 1828 CONFIG_GATEWAYIP 1829 1830 Defines a default value for the IP address of the 1831 default router where packets to other networks are 1832 sent to. 1833 (Environment variable "gatewayip") 1834 1835- Subnet mask: 1836 CONFIG_NETMASK 1837 1838 Defines a default value for the subnet mask (or 1839 routing prefix) which is used to determine if an IP 1840 address belongs to the local subnet or needs to be 1841 forwarded through a router. 1842 (Environment variable "netmask") 1843 1844- Multicast TFTP Mode: 1845 CONFIG_MCAST_TFTP 1846 1847 Defines whether you want to support multicast TFTP as per 1848 rfc-2090; for example to work with atftp. Lets lots of targets 1849 tftp down the same boot image concurrently. Note: the Ethernet 1850 driver in use must provide a function: mcast() to join/leave a 1851 multicast group. 1852 1853- BOOTP Recovery Mode: 1854 CONFIG_BOOTP_RANDOM_DELAY 1855 1856 If you have many targets in a network that try to 1857 boot using BOOTP, you may want to avoid that all 1858 systems send out BOOTP requests at precisely the same 1859 moment (which would happen for instance at recovery 1860 from a power failure, when all systems will try to 1861 boot, thus flooding the BOOTP server. Defining 1862 CONFIG_BOOTP_RANDOM_DELAY causes a random delay to be 1863 inserted before sending out BOOTP requests. The 1864 following delays are inserted then: 1865 1866 1st BOOTP request: delay 0 ... 1 sec 1867 2nd BOOTP request: delay 0 ... 2 sec 1868 3rd BOOTP request: delay 0 ... 4 sec 1869 4th and following 1870 BOOTP requests: delay 0 ... 8 sec 1871 1872 CONFIG_BOOTP_ID_CACHE_SIZE 1873 1874 BOOTP packets are uniquely identified using a 32-bit ID. The 1875 server will copy the ID from client requests to responses and 1876 U-Boot will use this to determine if it is the destination of 1877 an incoming response. Some servers will check that addresses 1878 aren't in use before handing them out (usually using an ARP 1879 ping) and therefore take up to a few hundred milliseconds to 1880 respond. Network congestion may also influence the time it 1881 takes for a response to make it back to the client. If that 1882 time is too long, U-Boot will retransmit requests. In order 1883 to allow earlier responses to still be accepted after these 1884 retransmissions, U-Boot's BOOTP client keeps a small cache of 1885 IDs. The CONFIG_BOOTP_ID_CACHE_SIZE controls the size of this 1886 cache. The default is to keep IDs for up to four outstanding 1887 requests. Increasing this will allow U-Boot to accept offers 1888 from a BOOTP client in networks with unusually high latency. 1889 1890- DHCP Advanced Options: 1891 You can fine tune the DHCP functionality by defining 1892 CONFIG_BOOTP_* symbols: 1893 1894 CONFIG_BOOTP_SUBNETMASK 1895 CONFIG_BOOTP_GATEWAY 1896 CONFIG_BOOTP_HOSTNAME 1897 CONFIG_BOOTP_NISDOMAIN 1898 CONFIG_BOOTP_BOOTPATH 1899 CONFIG_BOOTP_BOOTFILESIZE 1900 CONFIG_BOOTP_DNS 1901 CONFIG_BOOTP_DNS2 1902 CONFIG_BOOTP_SEND_HOSTNAME 1903 CONFIG_BOOTP_NTPSERVER 1904 CONFIG_BOOTP_TIMEOFFSET 1905 CONFIG_BOOTP_VENDOREX 1906 CONFIG_BOOTP_MAY_FAIL 1907 1908 CONFIG_BOOTP_SERVERIP - TFTP server will be the serverip 1909 environment variable, not the BOOTP server. 1910 1911 CONFIG_BOOTP_MAY_FAIL - If the DHCP server is not found 1912 after the configured retry count, the call will fail 1913 instead of starting over. This can be used to fail over 1914 to Link-local IP address configuration if the DHCP server 1915 is not available. 1916 1917 CONFIG_BOOTP_DNS2 - If a DHCP client requests the DNS 1918 serverip from a DHCP server, it is possible that more 1919 than one DNS serverip is offered to the client. 1920 If CONFIG_BOOTP_DNS2 is enabled, the secondary DNS 1921 serverip will be stored in the additional environment 1922 variable "dnsip2". The first DNS serverip is always 1923 stored in the variable "dnsip", when CONFIG_BOOTP_DNS 1924 is defined. 1925 1926 CONFIG_BOOTP_SEND_HOSTNAME - Some DHCP servers are capable 1927 to do a dynamic update of a DNS server. To do this, they 1928 need the hostname of the DHCP requester. 1929 If CONFIG_BOOTP_SEND_HOSTNAME is defined, the content 1930 of the "hostname" environment variable is passed as 1931 option 12 to the DHCP server. 1932 1933 CONFIG_BOOTP_DHCP_REQUEST_DELAY 1934 1935 A 32bit value in microseconds for a delay between 1936 receiving a "DHCP Offer" and sending the "DHCP Request". 1937 This fixes a problem with certain DHCP servers that don't 1938 respond 100% of the time to a "DHCP request". E.g. On an 1939 AT91RM9200 processor running at 180MHz, this delay needed 1940 to be *at least* 15,000 usec before a Windows Server 2003 1941 DHCP server would reply 100% of the time. I recommend at 1942 least 50,000 usec to be safe. The alternative is to hope 1943 that one of the retries will be successful but note that 1944 the DHCP timeout and retry process takes a longer than 1945 this delay. 1946 1947 - Link-local IP address negotiation: 1948 Negotiate with other link-local clients on the local network 1949 for an address that doesn't require explicit configuration. 1950 This is especially useful if a DHCP server cannot be guaranteed 1951 to exist in all environments that the device must operate. 1952 1953 See doc/README.link-local for more information. 1954 1955 - CDP Options: 1956 CONFIG_CDP_DEVICE_ID 1957 1958 The device id used in CDP trigger frames. 1959 1960 CONFIG_CDP_DEVICE_ID_PREFIX 1961 1962 A two character string which is prefixed to the MAC address 1963 of the device. 1964 1965 CONFIG_CDP_PORT_ID 1966 1967 A printf format string which contains the ascii name of 1968 the port. Normally is set to "eth%d" which sets 1969 eth0 for the first Ethernet, eth1 for the second etc. 1970 1971 CONFIG_CDP_CAPABILITIES 1972 1973 A 32bit integer which indicates the device capabilities; 1974 0x00000010 for a normal host which does not forwards. 1975 1976 CONFIG_CDP_VERSION 1977 1978 An ascii string containing the version of the software. 1979 1980 CONFIG_CDP_PLATFORM 1981 1982 An ascii string containing the name of the platform. 1983 1984 CONFIG_CDP_TRIGGER 1985 1986 A 32bit integer sent on the trigger. 1987 1988 CONFIG_CDP_POWER_CONSUMPTION 1989 1990 A 16bit integer containing the power consumption of the 1991 device in .1 of milliwatts. 1992 1993 CONFIG_CDP_APPLIANCE_VLAN_TYPE 1994 1995 A byte containing the id of the VLAN. 1996 1997- Status LED: CONFIG_LED_STATUS 1998 1999 Several configurations allow to display the current 2000 status using a LED. For instance, the LED will blink 2001 fast while running U-Boot code, stop blinking as 2002 soon as a reply to a BOOTP request was received, and 2003 start blinking slow once the Linux kernel is running 2004 (supported by a status LED driver in the Linux 2005 kernel). Defining CONFIG_LED_STATUS enables this 2006 feature in U-Boot. 2007 2008 Additional options: 2009 2010 CONFIG_LED_STATUS_GPIO 2011 The status LED can be connected to a GPIO pin. 2012 In such cases, the gpio_led driver can be used as a 2013 status LED backend implementation. Define CONFIG_LED_STATUS_GPIO 2014 to include the gpio_led driver in the U-Boot binary. 2015 2016 CONFIG_GPIO_LED_INVERTED_TABLE 2017 Some GPIO connected LEDs may have inverted polarity in which 2018 case the GPIO high value corresponds to LED off state and 2019 GPIO low value corresponds to LED on state. 2020 In such cases CONFIG_GPIO_LED_INVERTED_TABLE may be defined 2021 with a list of GPIO LEDs that have inverted polarity. 2022 2023- CAN Support: CONFIG_CAN_DRIVER 2024 2025 Defining CONFIG_CAN_DRIVER enables CAN driver support 2026 on those systems that support this (optional) 2027 feature, like the TQM8xxL modules. 2028 2029- I2C Support: CONFIG_SYS_I2C 2030 2031 This enable the NEW i2c subsystem, and will allow you to use 2032 i2c commands at the u-boot command line (as long as you set 2033 CONFIG_CMD_I2C in CONFIG_COMMANDS) and communicate with i2c 2034 based realtime clock chips or other i2c devices. See 2035 common/cmd_i2c.c for a description of the command line 2036 interface. 2037 2038 ported i2c driver to the new framework: 2039 - drivers/i2c/soft_i2c.c: 2040 - activate first bus with CONFIG_SYS_I2C_SOFT define 2041 CONFIG_SYS_I2C_SOFT_SPEED and CONFIG_SYS_I2C_SOFT_SLAVE 2042 for defining speed and slave address 2043 - activate second bus with I2C_SOFT_DECLARATIONS2 define 2044 CONFIG_SYS_I2C_SOFT_SPEED_2 and CONFIG_SYS_I2C_SOFT_SLAVE_2 2045 for defining speed and slave address 2046 - activate third bus with I2C_SOFT_DECLARATIONS3 define 2047 CONFIG_SYS_I2C_SOFT_SPEED_3 and CONFIG_SYS_I2C_SOFT_SLAVE_3 2048 for defining speed and slave address 2049 - activate fourth bus with I2C_SOFT_DECLARATIONS4 define 2050 CONFIG_SYS_I2C_SOFT_SPEED_4 and CONFIG_SYS_I2C_SOFT_SLAVE_4 2051 for defining speed and slave address 2052 2053 - drivers/i2c/fsl_i2c.c: 2054 - activate i2c driver with CONFIG_SYS_I2C_FSL 2055 define CONFIG_SYS_FSL_I2C_OFFSET for setting the register 2056 offset CONFIG_SYS_FSL_I2C_SPEED for the i2c speed and 2057 CONFIG_SYS_FSL_I2C_SLAVE for the slave addr of the first 2058 bus. 2059 - If your board supports a second fsl i2c bus, define 2060 CONFIG_SYS_FSL_I2C2_OFFSET for the register offset 2061 CONFIG_SYS_FSL_I2C2_SPEED for the speed and 2062 CONFIG_SYS_FSL_I2C2_SLAVE for the slave address of the 2063 second bus. 2064 2065 - drivers/i2c/tegra_i2c.c: 2066 - activate this driver with CONFIG_SYS_I2C_TEGRA 2067 - This driver adds 4 i2c buses with a fix speed from 2068 100000 and the slave addr 0! 2069 2070 - drivers/i2c/ppc4xx_i2c.c 2071 - activate this driver with CONFIG_SYS_I2C_PPC4XX 2072 - CONFIG_SYS_I2C_PPC4XX_CH0 activate hardware channel 0 2073 - CONFIG_SYS_I2C_PPC4XX_CH1 activate hardware channel 1 2074 2075 - drivers/i2c/i2c_mxc.c 2076 - activate this driver with CONFIG_SYS_I2C_MXC 2077 - enable bus 1 with CONFIG_SYS_I2C_MXC_I2C1 2078 - enable bus 2 with CONFIG_SYS_I2C_MXC_I2C2 2079 - enable bus 3 with CONFIG_SYS_I2C_MXC_I2C3 2080 - enable bus 4 with CONFIG_SYS_I2C_MXC_I2C4 2081 - define speed for bus 1 with CONFIG_SYS_MXC_I2C1_SPEED 2082 - define slave for bus 1 with CONFIG_SYS_MXC_I2C1_SLAVE 2083 - define speed for bus 2 with CONFIG_SYS_MXC_I2C2_SPEED 2084 - define slave for bus 2 with CONFIG_SYS_MXC_I2C2_SLAVE 2085 - define speed for bus 3 with CONFIG_SYS_MXC_I2C3_SPEED 2086 - define slave for bus 3 with CONFIG_SYS_MXC_I2C3_SLAVE 2087 - define speed for bus 4 with CONFIG_SYS_MXC_I2C4_SPEED 2088 - define slave for bus 4 with CONFIG_SYS_MXC_I2C4_SLAVE 2089 If those defines are not set, default value is 100000 2090 for speed, and 0 for slave. 2091 2092 - drivers/i2c/rcar_i2c.c: 2093 - activate this driver with CONFIG_SYS_I2C_RCAR 2094 - This driver adds 4 i2c buses 2095 2096 - CONFIG_SYS_RCAR_I2C0_BASE for setting the register channel 0 2097 - CONFIG_SYS_RCAR_I2C0_SPEED for for the speed channel 0 2098 - CONFIG_SYS_RCAR_I2C1_BASE for setting the register channel 1 2099 - CONFIG_SYS_RCAR_I2C1_SPEED for for the speed channel 1 2100 - CONFIG_SYS_RCAR_I2C2_BASE for setting the register channel 2 2101 - CONFIG_SYS_RCAR_I2C2_SPEED for for the speed channel 2 2102 - CONFIG_SYS_RCAR_I2C3_BASE for setting the register channel 3 2103 - CONFIG_SYS_RCAR_I2C3_SPEED for for the speed channel 3 2104 - CONFIF_SYS_RCAR_I2C_NUM_CONTROLLERS for number of i2c buses 2105 2106 - drivers/i2c/sh_i2c.c: 2107 - activate this driver with CONFIG_SYS_I2C_SH 2108 - This driver adds from 2 to 5 i2c buses 2109 2110 - CONFIG_SYS_I2C_SH_BASE0 for setting the register channel 0 2111 - CONFIG_SYS_I2C_SH_SPEED0 for for the speed channel 0 2112 - CONFIG_SYS_I2C_SH_BASE1 for setting the register channel 1 2113 - CONFIG_SYS_I2C_SH_SPEED1 for for the speed channel 1 2114 - CONFIG_SYS_I2C_SH_BASE2 for setting the register channel 2 2115 - CONFIG_SYS_I2C_SH_SPEED2 for for the speed channel 2 2116 - CONFIG_SYS_I2C_SH_BASE3 for setting the register channel 3 2117 - CONFIG_SYS_I2C_SH_SPEED3 for for the speed channel 3 2118 - CONFIG_SYS_I2C_SH_BASE4 for setting the register channel 4 2119 - CONFIG_SYS_I2C_SH_SPEED4 for for the speed channel 4 2120 - CONFIG_SYS_I2C_SH_NUM_CONTROLLERS for number of i2c buses 2121 2122 - drivers/i2c/omap24xx_i2c.c 2123 - activate this driver with CONFIG_SYS_I2C_OMAP24XX 2124 - CONFIG_SYS_OMAP24_I2C_SPEED speed channel 0 2125 - CONFIG_SYS_OMAP24_I2C_SLAVE slave addr channel 0 2126 - CONFIG_SYS_OMAP24_I2C_SPEED1 speed channel 1 2127 - CONFIG_SYS_OMAP24_I2C_SLAVE1 slave addr channel 1 2128 - CONFIG_SYS_OMAP24_I2C_SPEED2 speed channel 2 2129 - CONFIG_SYS_OMAP24_I2C_SLAVE2 slave addr channel 2 2130 - CONFIG_SYS_OMAP24_I2C_SPEED3 speed channel 3 2131 - CONFIG_SYS_OMAP24_I2C_SLAVE3 slave addr channel 3 2132 - CONFIG_SYS_OMAP24_I2C_SPEED4 speed channel 4 2133 - CONFIG_SYS_OMAP24_I2C_SLAVE4 slave addr channel 4 2134 2135 - drivers/i2c/zynq_i2c.c 2136 - activate this driver with CONFIG_SYS_I2C_ZYNQ 2137 - set CONFIG_SYS_I2C_ZYNQ_SPEED for speed setting 2138 - set CONFIG_SYS_I2C_ZYNQ_SLAVE for slave addr 2139 2140 - drivers/i2c/s3c24x0_i2c.c: 2141 - activate this driver with CONFIG_SYS_I2C_S3C24X0 2142 - This driver adds i2c buses (11 for Exynos5250, Exynos5420 2143 9 i2c buses for Exynos4 and 1 for S3C24X0 SoCs from Samsung) 2144 with a fix speed from 100000 and the slave addr 0! 2145 2146 - drivers/i2c/ihs_i2c.c 2147 - activate this driver with CONFIG_SYS_I2C_IHS 2148 - CONFIG_SYS_I2C_IHS_CH0 activate hardware channel 0 2149 - CONFIG_SYS_I2C_IHS_SPEED_0 speed channel 0 2150 - CONFIG_SYS_I2C_IHS_SLAVE_0 slave addr channel 0 2151 - CONFIG_SYS_I2C_IHS_CH1 activate hardware channel 1 2152 - CONFIG_SYS_I2C_IHS_SPEED_1 speed channel 1 2153 - CONFIG_SYS_I2C_IHS_SLAVE_1 slave addr channel 1 2154 - CONFIG_SYS_I2C_IHS_CH2 activate hardware channel 2 2155 - CONFIG_SYS_I2C_IHS_SPEED_2 speed channel 2 2156 - CONFIG_SYS_I2C_IHS_SLAVE_2 slave addr channel 2 2157 - CONFIG_SYS_I2C_IHS_CH3 activate hardware channel 3 2158 - CONFIG_SYS_I2C_IHS_SPEED_3 speed channel 3 2159 - CONFIG_SYS_I2C_IHS_SLAVE_3 slave addr channel 3 2160 - activate dual channel with CONFIG_SYS_I2C_IHS_DUAL 2161 - CONFIG_SYS_I2C_IHS_SPEED_0_1 speed channel 0_1 2162 - CONFIG_SYS_I2C_IHS_SLAVE_0_1 slave addr channel 0_1 2163 - CONFIG_SYS_I2C_IHS_SPEED_1_1 speed channel 1_1 2164 - CONFIG_SYS_I2C_IHS_SLAVE_1_1 slave addr channel 1_1 2165 - CONFIG_SYS_I2C_IHS_SPEED_2_1 speed channel 2_1 2166 - CONFIG_SYS_I2C_IHS_SLAVE_2_1 slave addr channel 2_1 2167 - CONFIG_SYS_I2C_IHS_SPEED_3_1 speed channel 3_1 2168 - CONFIG_SYS_I2C_IHS_SLAVE_3_1 slave addr channel 3_1 2169 2170 additional defines: 2171 2172 CONFIG_SYS_NUM_I2C_BUSES 2173 Hold the number of i2c buses you want to use. 2174 2175 CONFIG_SYS_I2C_DIRECT_BUS 2176 define this, if you don't use i2c muxes on your hardware. 2177 if CONFIG_SYS_I2C_MAX_HOPS is not defined or == 0 you can 2178 omit this define. 2179 2180 CONFIG_SYS_I2C_MAX_HOPS 2181 define how many muxes are maximal consecutively connected 2182 on one i2c bus. If you not use i2c muxes, omit this 2183 define. 2184 2185 CONFIG_SYS_I2C_BUSES 2186 hold a list of buses you want to use, only used if 2187 CONFIG_SYS_I2C_DIRECT_BUS is not defined, for example 2188 a board with CONFIG_SYS_I2C_MAX_HOPS = 1 and 2189 CONFIG_SYS_NUM_I2C_BUSES = 9: 2190 2191 CONFIG_SYS_I2C_BUSES {{0, {I2C_NULL_HOP}}, \ 2192 {0, {{I2C_MUX_PCA9547, 0x70, 1}}}, \ 2193 {0, {{I2C_MUX_PCA9547, 0x70, 2}}}, \ 2194 {0, {{I2C_MUX_PCA9547, 0x70, 3}}}, \ 2195 {0, {{I2C_MUX_PCA9547, 0x70, 4}}}, \ 2196 {0, {{I2C_MUX_PCA9547, 0x70, 5}}}, \ 2197 {1, {I2C_NULL_HOP}}, \ 2198 {1, {{I2C_MUX_PCA9544, 0x72, 1}}}, \ 2199 {1, {{I2C_MUX_PCA9544, 0x72, 2}}}, \ 2200 } 2201 2202 which defines 2203 bus 0 on adapter 0 without a mux 2204 bus 1 on adapter 0 with a PCA9547 on address 0x70 port 1 2205 bus 2 on adapter 0 with a PCA9547 on address 0x70 port 2 2206 bus 3 on adapter 0 with a PCA9547 on address 0x70 port 3 2207 bus 4 on adapter 0 with a PCA9547 on address 0x70 port 4 2208 bus 5 on adapter 0 with a PCA9547 on address 0x70 port 5 2209 bus 6 on adapter 1 without a mux 2210 bus 7 on adapter 1 with a PCA9544 on address 0x72 port 1 2211 bus 8 on adapter 1 with a PCA9544 on address 0x72 port 2 2212 2213 If you do not have i2c muxes on your board, omit this define. 2214 2215- Legacy I2C Support: CONFIG_HARD_I2C 2216 2217 NOTE: It is intended to move drivers to CONFIG_SYS_I2C which 2218 provides the following compelling advantages: 2219 2220 - more than one i2c adapter is usable 2221 - approved multibus support 2222 - better i2c mux support 2223 2224 ** Please consider updating your I2C driver now. ** 2225 2226 These enable legacy I2C serial bus commands. Defining 2227 CONFIG_HARD_I2C will include the appropriate I2C driver 2228 for the selected CPU. 2229 2230 This will allow you to use i2c commands at the u-boot 2231 command line (as long as you set CONFIG_CMD_I2C in 2232 CONFIG_COMMANDS) and communicate with i2c based realtime 2233 clock chips. See common/cmd_i2c.c for a description of the 2234 command line interface. 2235 2236 CONFIG_HARD_I2C selects a hardware I2C controller. 2237 2238 There are several other quantities that must also be 2239 defined when you define CONFIG_HARD_I2C. 2240 2241 In both cases you will need to define CONFIG_SYS_I2C_SPEED 2242 to be the frequency (in Hz) at which you wish your i2c bus 2243 to run and CONFIG_SYS_I2C_SLAVE to be the address of this node (ie 2244 the CPU's i2c node address). 2245 2246 Now, the u-boot i2c code for the mpc8xx 2247 (arch/powerpc/cpu/mpc8xx/i2c.c) sets the CPU up as a master node 2248 and so its address should therefore be cleared to 0 (See, 2249 eg, MPC823e User's Manual p.16-473). So, set 2250 CONFIG_SYS_I2C_SLAVE to 0. 2251 2252 CONFIG_SYS_I2C_INIT_MPC5XXX 2253 2254 When a board is reset during an i2c bus transfer 2255 chips might think that the current transfer is still 2256 in progress. Reset the slave devices by sending start 2257 commands until the slave device responds. 2258 2259 That's all that's required for CONFIG_HARD_I2C. 2260 2261 If you use the software i2c interface (CONFIG_SYS_I2C_SOFT) 2262 then the following macros need to be defined (examples are 2263 from include/configs/lwmon.h): 2264 2265 I2C_INIT 2266 2267 (Optional). Any commands necessary to enable the I2C 2268 controller or configure ports. 2269 2270 eg: #define I2C_INIT (immr->im_cpm.cp_pbdir |= PB_SCL) 2271 2272 I2C_PORT 2273 2274 (Only for MPC8260 CPU). The I/O port to use (the code 2275 assumes both bits are on the same port). Valid values 2276 are 0..3 for ports A..D. 2277 2278 I2C_ACTIVE 2279 2280 The code necessary to make the I2C data line active 2281 (driven). If the data line is open collector, this 2282 define can be null. 2283 2284 eg: #define I2C_ACTIVE (immr->im_cpm.cp_pbdir |= PB_SDA) 2285 2286 I2C_TRISTATE 2287 2288 The code necessary to make the I2C data line tri-stated 2289 (inactive). If the data line is open collector, this 2290 define can be null. 2291 2292 eg: #define I2C_TRISTATE (immr->im_cpm.cp_pbdir &= ~PB_SDA) 2293 2294 I2C_READ 2295 2296 Code that returns true if the I2C data line is high, 2297 false if it is low. 2298 2299 eg: #define I2C_READ ((immr->im_cpm.cp_pbdat & PB_SDA) != 0) 2300 2301 I2C_SDA(bit) 2302 2303 If <bit> is true, sets the I2C data line high. If it 2304 is false, it clears it (low). 2305 2306 eg: #define I2C_SDA(bit) \ 2307 if(bit) immr->im_cpm.cp_pbdat |= PB_SDA; \ 2308 else immr->im_cpm.cp_pbdat &= ~PB_SDA 2309 2310 I2C_SCL(bit) 2311 2312 If <bit> is true, sets the I2C clock line high. If it 2313 is false, it clears it (low). 2314 2315 eg: #define I2C_SCL(bit) \ 2316 if(bit) immr->im_cpm.cp_pbdat |= PB_SCL; \ 2317 else immr->im_cpm.cp_pbdat &= ~PB_SCL 2318 2319 I2C_DELAY 2320 2321 This delay is invoked four times per clock cycle so this 2322 controls the rate of data transfer. The data rate thus 2323 is 1 / (I2C_DELAY * 4). Often defined to be something 2324 like: 2325 2326 #define I2C_DELAY udelay(2) 2327 2328 CONFIG_SOFT_I2C_GPIO_SCL / CONFIG_SOFT_I2C_GPIO_SDA 2329 2330 If your arch supports the generic GPIO framework (asm/gpio.h), 2331 then you may alternatively define the two GPIOs that are to be 2332 used as SCL / SDA. Any of the previous I2C_xxx macros will 2333 have GPIO-based defaults assigned to them as appropriate. 2334 2335 You should define these to the GPIO value as given directly to 2336 the generic GPIO functions. 2337 2338 CONFIG_SYS_I2C_INIT_BOARD 2339 2340 When a board is reset during an i2c bus transfer 2341 chips might think that the current transfer is still 2342 in progress. On some boards it is possible to access 2343 the i2c SCLK line directly, either by using the 2344 processor pin as a GPIO or by having a second pin 2345 connected to the bus. If this option is defined a 2346 custom i2c_init_board() routine in boards/xxx/board.c 2347 is run early in the boot sequence. 2348 2349 CONFIG_SYS_I2C_BOARD_LATE_INIT 2350 2351 An alternative to CONFIG_SYS_I2C_INIT_BOARD. If this option is 2352 defined a custom i2c_board_late_init() routine in 2353 boards/xxx/board.c is run AFTER the operations in i2c_init() 2354 is completed. This callpoint can be used to unreset i2c bus 2355 using CPU i2c controller register accesses for CPUs whose i2c 2356 controller provide such a method. It is called at the end of 2357 i2c_init() to allow i2c_init operations to setup the i2c bus 2358 controller on the CPU (e.g. setting bus speed & slave address). 2359 2360 CONFIG_I2CFAST (PPC405GP|PPC405EP only) 2361 2362 This option enables configuration of bi_iic_fast[] flags 2363 in u-boot bd_info structure based on u-boot environment 2364 variable "i2cfast". (see also i2cfast) 2365 2366 CONFIG_I2C_MULTI_BUS 2367 2368 This option allows the use of multiple I2C buses, each of which 2369 must have a controller. At any point in time, only one bus is 2370 active. To switch to a different bus, use the 'i2c dev' command. 2371 Note that bus numbering is zero-based. 2372 2373 CONFIG_SYS_I2C_NOPROBES 2374 2375 This option specifies a list of I2C devices that will be skipped 2376 when the 'i2c probe' command is issued. If CONFIG_I2C_MULTI_BUS 2377 is set, specify a list of bus-device pairs. Otherwise, specify 2378 a 1D array of device addresses 2379 2380 e.g. 2381 #undef CONFIG_I2C_MULTI_BUS 2382 #define CONFIG_SYS_I2C_NOPROBES {0x50,0x68} 2383 2384 will skip addresses 0x50 and 0x68 on a board with one I2C bus 2385 2386 #define CONFIG_I2C_MULTI_BUS 2387 #define CONFIG_SYS_I2C_NOPROBES {{0,0x50},{0,0x68},{1,0x54}} 2388 2389 will skip addresses 0x50 and 0x68 on bus 0 and address 0x54 on bus 1 2390 2391 CONFIG_SYS_SPD_BUS_NUM 2392 2393 If defined, then this indicates the I2C bus number for DDR SPD. 2394 If not defined, then U-Boot assumes that SPD is on I2C bus 0. 2395 2396 CONFIG_SYS_RTC_BUS_NUM 2397 2398 If defined, then this indicates the I2C bus number for the RTC. 2399 If not defined, then U-Boot assumes that RTC is on I2C bus 0. 2400 2401 CONFIG_SYS_DTT_BUS_NUM 2402 2403 If defined, then this indicates the I2C bus number for the DTT. 2404 If not defined, then U-Boot assumes that DTT is on I2C bus 0. 2405 2406 CONFIG_SYS_I2C_DTT_ADDR: 2407 2408 If defined, specifies the I2C address of the DTT device. 2409 If not defined, then U-Boot uses predefined value for 2410 specified DTT device. 2411 2412 CONFIG_SOFT_I2C_READ_REPEATED_START 2413 2414 defining this will force the i2c_read() function in 2415 the soft_i2c driver to perform an I2C repeated start 2416 between writing the address pointer and reading the 2417 data. If this define is omitted the default behaviour 2418 of doing a stop-start sequence will be used. Most I2C 2419 devices can use either method, but some require one or 2420 the other. 2421 2422- SPI Support: CONFIG_SPI 2423 2424 Enables SPI driver (so far only tested with 2425 SPI EEPROM, also an instance works with Crystal A/D and 2426 D/As on the SACSng board) 2427 2428 CONFIG_SH_SPI 2429 2430 Enables the driver for SPI controller on SuperH. Currently 2431 only SH7757 is supported. 2432 2433 CONFIG_SOFT_SPI 2434 2435 Enables a software (bit-bang) SPI driver rather than 2436 using hardware support. This is a general purpose 2437 driver that only requires three general I/O port pins 2438 (two outputs, one input) to function. If this is 2439 defined, the board configuration must define several 2440 SPI configuration items (port pins to use, etc). For 2441 an example, see include/configs/sacsng.h. 2442 2443 CONFIG_HARD_SPI 2444 2445 Enables a hardware SPI driver for general-purpose reads 2446 and writes. As with CONFIG_SOFT_SPI, the board configuration 2447 must define a list of chip-select function pointers. 2448 Currently supported on some MPC8xxx processors. For an 2449 example, see include/configs/mpc8349emds.h. 2450 2451 CONFIG_MXC_SPI 2452 2453 Enables the driver for the SPI controllers on i.MX and MXC 2454 SoCs. Currently i.MX31/35/51 are supported. 2455 2456 CONFIG_SYS_SPI_MXC_WAIT 2457 Timeout for waiting until spi transfer completed. 2458 default: (CONFIG_SYS_HZ/100) /* 10 ms */ 2459 2460- FPGA Support: CONFIG_FPGA 2461 2462 Enables FPGA subsystem. 2463 2464 CONFIG_FPGA_<vendor> 2465 2466 Enables support for specific chip vendors. 2467 (ALTERA, XILINX) 2468 2469 CONFIG_FPGA_<family> 2470 2471 Enables support for FPGA family. 2472 (SPARTAN2, SPARTAN3, VIRTEX2, CYCLONE2, ACEX1K, ACEX) 2473 2474 CONFIG_FPGA_COUNT 2475 2476 Specify the number of FPGA devices to support. 2477 2478 CONFIG_CMD_FPGA_LOADMK 2479 2480 Enable support for fpga loadmk command 2481 2482 CONFIG_CMD_FPGA_LOADP 2483 2484 Enable support for fpga loadp command - load partial bitstream 2485 2486 CONFIG_CMD_FPGA_LOADBP 2487 2488 Enable support for fpga loadbp command - load partial bitstream 2489 (Xilinx only) 2490 2491 CONFIG_SYS_FPGA_PROG_FEEDBACK 2492 2493 Enable printing of hash marks during FPGA configuration. 2494 2495 CONFIG_SYS_FPGA_CHECK_BUSY 2496 2497 Enable checks on FPGA configuration interface busy 2498 status by the configuration function. This option 2499 will require a board or device specific function to 2500 be written. 2501 2502 CONFIG_FPGA_DELAY 2503 2504 If defined, a function that provides delays in the FPGA 2505 configuration driver. 2506 2507 CONFIG_SYS_FPGA_CHECK_CTRLC 2508 Allow Control-C to interrupt FPGA configuration 2509 2510 CONFIG_SYS_FPGA_CHECK_ERROR 2511 2512 Check for configuration errors during FPGA bitfile 2513 loading. For example, abort during Virtex II 2514 configuration if the INIT_B line goes low (which 2515 indicated a CRC error). 2516 2517 CONFIG_SYS_FPGA_WAIT_INIT 2518 2519 Maximum time to wait for the INIT_B line to de-assert 2520 after PROB_B has been de-asserted during a Virtex II 2521 FPGA configuration sequence. The default time is 500 2522 ms. 2523 2524 CONFIG_SYS_FPGA_WAIT_BUSY 2525 2526 Maximum time to wait for BUSY to de-assert during 2527 Virtex II FPGA configuration. The default is 5 ms. 2528 2529 CONFIG_SYS_FPGA_WAIT_CONFIG 2530 2531 Time to wait after FPGA configuration. The default is 2532 200 ms. 2533 2534- Configuration Management: 2535 CONFIG_BUILD_TARGET 2536 2537 Some SoCs need special image types (e.g. U-Boot binary 2538 with a special header) as build targets. By defining 2539 CONFIG_BUILD_TARGET in the SoC / board header, this 2540 special image will be automatically built upon calling 2541 make / buildman. 2542 2543 CONFIG_IDENT_STRING 2544 2545 If defined, this string will be added to the U-Boot 2546 version information (U_BOOT_VERSION) 2547 2548- Vendor Parameter Protection: 2549 2550 U-Boot considers the values of the environment 2551 variables "serial#" (Board Serial Number) and 2552 "ethaddr" (Ethernet Address) to be parameters that 2553 are set once by the board vendor / manufacturer, and 2554 protects these variables from casual modification by 2555 the user. Once set, these variables are read-only, 2556 and write or delete attempts are rejected. You can 2557 change this behaviour: 2558 2559 If CONFIG_ENV_OVERWRITE is #defined in your config 2560 file, the write protection for vendor parameters is 2561 completely disabled. Anybody can change or delete 2562 these parameters. 2563 2564 Alternatively, if you define _both_ an ethaddr in the 2565 default env _and_ CONFIG_OVERWRITE_ETHADDR_ONCE, a default 2566 Ethernet address is installed in the environment, 2567 which can be changed exactly ONCE by the user. [The 2568 serial# is unaffected by this, i. e. it remains 2569 read-only.] 2570 2571 The same can be accomplished in a more flexible way 2572 for any variable by configuring the type of access 2573 to allow for those variables in the ".flags" variable 2574 or define CONFIG_ENV_FLAGS_LIST_STATIC. 2575 2576- Protected RAM: 2577 CONFIG_PRAM 2578 2579 Define this variable to enable the reservation of 2580 "protected RAM", i. e. RAM which is not overwritten 2581 by U-Boot. Define CONFIG_PRAM to hold the number of 2582 kB you want to reserve for pRAM. You can overwrite 2583 this default value by defining an environment 2584 variable "pram" to the number of kB you want to 2585 reserve. Note that the board info structure will 2586 still show the full amount of RAM. If pRAM is 2587 reserved, a new environment variable "mem" will 2588 automatically be defined to hold the amount of 2589 remaining RAM in a form that can be passed as boot 2590 argument to Linux, for instance like that: 2591 2592 setenv bootargs ... mem=\${mem} 2593 saveenv 2594 2595 This way you can tell Linux not to use this memory, 2596 either, which results in a memory region that will 2597 not be affected by reboots. 2598 2599 *WARNING* If your board configuration uses automatic 2600 detection of the RAM size, you must make sure that 2601 this memory test is non-destructive. So far, the 2602 following board configurations are known to be 2603 "pRAM-clean": 2604 2605 IVMS8, IVML24, SPD8xx, TQM8xxL, 2606 HERMES, IP860, RPXlite, LWMON, 2607 FLAGADM, TQM8260 2608 2609- Access to physical memory region (> 4GB) 2610 Some basic support is provided for operations on memory not 2611 normally accessible to U-Boot - e.g. some architectures 2612 support access to more than 4GB of memory on 32-bit 2613 machines using physical address extension or similar. 2614 Define CONFIG_PHYSMEM to access this basic support, which 2615 currently only supports clearing the memory. 2616 2617- Error Recovery: 2618 CONFIG_PANIC_HANG 2619 2620 Define this variable to stop the system in case of a 2621 fatal error, so that you have to reset it manually. 2622 This is probably NOT a good idea for an embedded 2623 system where you want the system to reboot 2624 automatically as fast as possible, but it may be 2625 useful during development since you can try to debug 2626 the conditions that lead to the situation. 2627 2628 CONFIG_NET_RETRY_COUNT 2629 2630 This variable defines the number of retries for 2631 network operations like ARP, RARP, TFTP, or BOOTP 2632 before giving up the operation. If not defined, a 2633 default value of 5 is used. 2634 2635 CONFIG_ARP_TIMEOUT 2636 2637 Timeout waiting for an ARP reply in milliseconds. 2638 2639 CONFIG_NFS_TIMEOUT 2640 2641 Timeout in milliseconds used in NFS protocol. 2642 If you encounter "ERROR: Cannot umount" in nfs command, 2643 try longer timeout such as 2644 #define CONFIG_NFS_TIMEOUT 10000UL 2645 2646- Command Interpreter: 2647 CONFIG_AUTO_COMPLETE 2648 2649 Enable auto completion of commands using TAB. 2650 2651 CONFIG_SYS_PROMPT_HUSH_PS2 2652 2653 This defines the secondary prompt string, which is 2654 printed when the command interpreter needs more input 2655 to complete a command. Usually "> ". 2656 2657 Note: 2658 2659 In the current implementation, the local variables 2660 space and global environment variables space are 2661 separated. Local variables are those you define by 2662 simply typing `name=value'. To access a local 2663 variable later on, you have write `$name' or 2664 `${name}'; to execute the contents of a variable 2665 directly type `$name' at the command prompt. 2666 2667 Global environment variables are those you use 2668 setenv/printenv to work with. To run a command stored 2669 in such a variable, you need to use the run command, 2670 and you must not use the '$' sign to access them. 2671 2672 To store commands and special characters in a 2673 variable, please use double quotation marks 2674 surrounding the whole text of the variable, instead 2675 of the backslashes before semicolons and special 2676 symbols. 2677 2678- Command Line Editing and History: 2679 CONFIG_CMDLINE_EDITING 2680 2681 Enable editing and History functions for interactive 2682 command line input operations 2683 2684- Command Line PS1/PS2 support: 2685 CONFIG_CMDLINE_PS_SUPPORT 2686 2687 Enable support for changing the command prompt string 2688 at run-time. Only static string is supported so far. 2689 The string is obtained from environment variables PS1 2690 and PS2. 2691 2692- Default Environment: 2693 CONFIG_EXTRA_ENV_SETTINGS 2694 2695 Define this to contain any number of null terminated 2696 strings (variable = value pairs) that will be part of 2697 the default environment compiled into the boot image. 2698 2699 For example, place something like this in your 2700 board's config file: 2701 2702 #define CONFIG_EXTRA_ENV_SETTINGS \ 2703 "myvar1=value1\0" \ 2704 "myvar2=value2\0" 2705 2706 Warning: This method is based on knowledge about the 2707 internal format how the environment is stored by the 2708 U-Boot code. This is NOT an official, exported 2709 interface! Although it is unlikely that this format 2710 will change soon, there is no guarantee either. 2711 You better know what you are doing here. 2712 2713 Note: overly (ab)use of the default environment is 2714 discouraged. Make sure to check other ways to preset 2715 the environment like the "source" command or the 2716 boot command first. 2717 2718 CONFIG_ENV_VARS_UBOOT_CONFIG 2719 2720 Define this in order to add variables describing the 2721 U-Boot build configuration to the default environment. 2722 These will be named arch, cpu, board, vendor, and soc. 2723 2724 Enabling this option will cause the following to be defined: 2725 2726 - CONFIG_SYS_ARCH 2727 - CONFIG_SYS_CPU 2728 - CONFIG_SYS_BOARD 2729 - CONFIG_SYS_VENDOR 2730 - CONFIG_SYS_SOC 2731 2732 CONFIG_ENV_VARS_UBOOT_RUNTIME_CONFIG 2733 2734 Define this in order to add variables describing certain 2735 run-time determined information about the hardware to the 2736 environment. These will be named board_name, board_rev. 2737 2738 CONFIG_DELAY_ENVIRONMENT 2739 2740 Normally the environment is loaded when the board is 2741 initialised so that it is available to U-Boot. This inhibits 2742 that so that the environment is not available until 2743 explicitly loaded later by U-Boot code. With CONFIG_OF_CONTROL 2744 this is instead controlled by the value of 2745 /config/load-environment. 2746 2747- DataFlash Support: 2748 CONFIG_HAS_DATAFLASH 2749 2750 Defining this option enables DataFlash features and 2751 allows to read/write in Dataflash via the standard 2752 commands cp, md... 2753 2754- Serial Flash support 2755 CONFIG_CMD_SF 2756 2757 Defining this option enables SPI flash commands 2758 'sf probe/read/write/erase/update'. 2759 2760 Usage requires an initial 'probe' to define the serial 2761 flash parameters, followed by read/write/erase/update 2762 commands. 2763 2764 The following defaults may be provided by the platform 2765 to handle the common case when only a single serial 2766 flash is present on the system. 2767 2768 CONFIG_SF_DEFAULT_BUS Bus identifier 2769 CONFIG_SF_DEFAULT_CS Chip-select 2770 CONFIG_SF_DEFAULT_MODE (see include/spi.h) 2771 CONFIG_SF_DEFAULT_SPEED in Hz 2772 2773 CONFIG_CMD_SF_TEST 2774 2775 Define this option to include a destructive SPI flash 2776 test ('sf test'). 2777 2778 CONFIG_SF_DUAL_FLASH Dual flash memories 2779 2780 Define this option to use dual flash support where two flash 2781 memories can be connected with a given cs line. 2782 Currently Xilinx Zynq qspi supports these type of connections. 2783 2784- SystemACE Support: 2785 CONFIG_SYSTEMACE 2786 2787 Adding this option adds support for Xilinx SystemACE 2788 chips attached via some sort of local bus. The address 2789 of the chip must also be defined in the 2790 CONFIG_SYS_SYSTEMACE_BASE macro. For example: 2791 2792 #define CONFIG_SYSTEMACE 2793 #define CONFIG_SYS_SYSTEMACE_BASE 0xf0000000 2794 2795 When SystemACE support is added, the "ace" device type 2796 becomes available to the fat commands, i.e. fatls. 2797 2798- TFTP Fixed UDP Port: 2799 CONFIG_TFTP_PORT 2800 2801 If this is defined, the environment variable tftpsrcp 2802 is used to supply the TFTP UDP source port value. 2803 If tftpsrcp isn't defined, the normal pseudo-random port 2804 number generator is used. 2805 2806 Also, the environment variable tftpdstp is used to supply 2807 the TFTP UDP destination port value. If tftpdstp isn't 2808 defined, the normal port 69 is used. 2809 2810 The purpose for tftpsrcp is to allow a TFTP server to 2811 blindly start the TFTP transfer using the pre-configured 2812 target IP address and UDP port. This has the effect of 2813 "punching through" the (Windows XP) firewall, allowing 2814 the remainder of the TFTP transfer to proceed normally. 2815 A better solution is to properly configure the firewall, 2816 but sometimes that is not allowed. 2817 2818- Hashing support: 2819 CONFIG_CMD_HASH 2820 2821 This enables a generic 'hash' command which can produce 2822 hashes / digests from a few algorithms (e.g. SHA1, SHA256). 2823 2824 CONFIG_HASH_VERIFY 2825 2826 Enable the hash verify command (hash -v). This adds to code 2827 size a little. 2828 2829 CONFIG_SHA1 - This option enables support of hashing using SHA1 2830 algorithm. The hash is calculated in software. 2831 CONFIG_SHA256 - This option enables support of hashing using 2832 SHA256 algorithm. The hash is calculated in software. 2833 CONFIG_SHA_HW_ACCEL - This option enables hardware acceleration 2834 for SHA1/SHA256 hashing. 2835 This affects the 'hash' command and also the 2836 hash_lookup_algo() function. 2837 CONFIG_SHA_PROG_HW_ACCEL - This option enables 2838 hardware-acceleration for SHA1/SHA256 progressive hashing. 2839 Data can be streamed in a block at a time and the hashing 2840 is performed in hardware. 2841 2842 Note: There is also a sha1sum command, which should perhaps 2843 be deprecated in favour of 'hash sha1'. 2844 2845- Freescale i.MX specific commands: 2846 CONFIG_CMD_HDMIDETECT 2847 This enables 'hdmidet' command which returns true if an 2848 HDMI monitor is detected. This command is i.MX 6 specific. 2849 2850- bootcount support: 2851 CONFIG_BOOTCOUNT_LIMIT 2852 2853 This enables the bootcounter support, see: 2854 http://www.denx.de/wiki/DULG/UBootBootCountLimit 2855 2856 CONFIG_AT91SAM9XE 2857 enable special bootcounter support on at91sam9xe based boards. 2858 CONFIG_SOC_DA8XX 2859 enable special bootcounter support on da850 based boards. 2860 CONFIG_BOOTCOUNT_RAM 2861 enable support for the bootcounter in RAM 2862 CONFIG_BOOTCOUNT_I2C 2863 enable support for the bootcounter on an i2c (like RTC) device. 2864 CONFIG_SYS_I2C_RTC_ADDR = i2c chip address 2865 CONFIG_SYS_BOOTCOUNT_ADDR = i2c addr which is used for 2866 the bootcounter. 2867 CONFIG_BOOTCOUNT_ALEN = address len 2868 2869- Show boot progress: 2870 CONFIG_SHOW_BOOT_PROGRESS 2871 2872 Defining this option allows to add some board- 2873 specific code (calling a user-provided function 2874 "show_boot_progress(int)") that enables you to show 2875 the system's boot progress on some display (for 2876 example, some LED's) on your board. At the moment, 2877 the following checkpoints are implemented: 2878 2879 2880Legacy uImage format: 2881 2882 Arg Where When 2883 1 common/cmd_bootm.c before attempting to boot an image 2884 -1 common/cmd_bootm.c Image header has bad magic number 2885 2 common/cmd_bootm.c Image header has correct magic number 2886 -2 common/cmd_bootm.c Image header has bad checksum 2887 3 common/cmd_bootm.c Image header has correct checksum 2888 -3 common/cmd_bootm.c Image data has bad checksum 2889 4 common/cmd_bootm.c Image data has correct checksum 2890 -4 common/cmd_bootm.c Image is for unsupported architecture 2891 5 common/cmd_bootm.c Architecture check OK 2892 -5 common/cmd_bootm.c Wrong Image Type (not kernel, multi) 2893 6 common/cmd_bootm.c Image Type check OK 2894 -6 common/cmd_bootm.c gunzip uncompression error 2895 -7 common/cmd_bootm.c Unimplemented compression type 2896 7 common/cmd_bootm.c Uncompression OK 2897 8 common/cmd_bootm.c No uncompress/copy overwrite error 2898 -9 common/cmd_bootm.c Unsupported OS (not Linux, BSD, VxWorks, QNX) 2899 2900 9 common/image.c Start initial ramdisk verification 2901 -10 common/image.c Ramdisk header has bad magic number 2902 -11 common/image.c Ramdisk header has bad checksum 2903 10 common/image.c Ramdisk header is OK 2904 -12 common/image.c Ramdisk data has bad checksum 2905 11 common/image.c Ramdisk data has correct checksum 2906 12 common/image.c Ramdisk verification complete, start loading 2907 -13 common/image.c Wrong Image Type (not PPC Linux ramdisk) 2908 13 common/image.c Start multifile image verification 2909 14 common/image.c No initial ramdisk, no multifile, continue. 2910 2911 15 arch/<arch>/lib/bootm.c All preparation done, transferring control to OS 2912 2913 -30 arch/powerpc/lib/board.c Fatal error, hang the system 2914 -31 post/post.c POST test failed, detected by post_output_backlog() 2915 -32 post/post.c POST test failed, detected by post_run_single() 2916 2917 34 common/cmd_doc.c before loading a Image from a DOC device 2918 -35 common/cmd_doc.c Bad usage of "doc" command 2919 35 common/cmd_doc.c correct usage of "doc" command 2920 -36 common/cmd_doc.c No boot device 2921 36 common/cmd_doc.c correct boot device 2922 -37 common/cmd_doc.c Unknown Chip ID on boot device 2923 37 common/cmd_doc.c correct chip ID found, device available 2924 -38 common/cmd_doc.c Read Error on boot device 2925 38 common/cmd_doc.c reading Image header from DOC device OK 2926 -39 common/cmd_doc.c Image header has bad magic number 2927 39 common/cmd_doc.c Image header has correct magic number 2928 -40 common/cmd_doc.c Error reading Image from DOC device 2929 40 common/cmd_doc.c Image header has correct magic number 2930 41 common/cmd_ide.c before loading a Image from a IDE device 2931 -42 common/cmd_ide.c Bad usage of "ide" command 2932 42 common/cmd_ide.c correct usage of "ide" command 2933 -43 common/cmd_ide.c No boot device 2934 43 common/cmd_ide.c boot device found 2935 -44 common/cmd_ide.c Device not available 2936 44 common/cmd_ide.c Device available 2937 -45 common/cmd_ide.c wrong partition selected 2938 45 common/cmd_ide.c partition selected 2939 -46 common/cmd_ide.c Unknown partition table 2940 46 common/cmd_ide.c valid partition table found 2941 -47 common/cmd_ide.c Invalid partition type 2942 47 common/cmd_ide.c correct partition type 2943 -48 common/cmd_ide.c Error reading Image Header on boot device 2944 48 common/cmd_ide.c reading Image Header from IDE device OK 2945 -49 common/cmd_ide.c Image header has bad magic number 2946 49 common/cmd_ide.c Image header has correct magic number 2947 -50 common/cmd_ide.c Image header has bad checksum 2948 50 common/cmd_ide.c Image header has correct checksum 2949 -51 common/cmd_ide.c Error reading Image from IDE device 2950 51 common/cmd_ide.c reading Image from IDE device OK 2951 52 common/cmd_nand.c before loading a Image from a NAND device 2952 -53 common/cmd_nand.c Bad usage of "nand" command 2953 53 common/cmd_nand.c correct usage of "nand" command 2954 -54 common/cmd_nand.c No boot device 2955 54 common/cmd_nand.c boot device found 2956 -55 common/cmd_nand.c Unknown Chip ID on boot device 2957 55 common/cmd_nand.c correct chip ID found, device available 2958 -56 common/cmd_nand.c Error reading Image Header on boot device 2959 56 common/cmd_nand.c reading Image Header from NAND device OK 2960 -57 common/cmd_nand.c Image header has bad magic number 2961 57 common/cmd_nand.c Image header has correct magic number 2962 -58 common/cmd_nand.c Error reading Image from NAND device 2963 58 common/cmd_nand.c reading Image from NAND device OK 2964 2965 -60 common/env_common.c Environment has a bad CRC, using default 2966 2967 64 net/eth.c starting with Ethernet configuration. 2968 -64 net/eth.c no Ethernet found. 2969 65 net/eth.c Ethernet found. 2970 2971 -80 common/cmd_net.c usage wrong 2972 80 common/cmd_net.c before calling net_loop() 2973 -81 common/cmd_net.c some error in net_loop() occurred 2974 81 common/cmd_net.c net_loop() back without error 2975 -82 common/cmd_net.c size == 0 (File with size 0 loaded) 2976 82 common/cmd_net.c trying automatic boot 2977 83 common/cmd_net.c running "source" command 2978 -83 common/cmd_net.c some error in automatic boot or "source" command 2979 84 common/cmd_net.c end without errors 2980 2981FIT uImage format: 2982 2983 Arg Where When 2984 100 common/cmd_bootm.c Kernel FIT Image has correct format 2985 -100 common/cmd_bootm.c Kernel FIT Image has incorrect format 2986 101 common/cmd_bootm.c No Kernel subimage unit name, using configuration 2987 -101 common/cmd_bootm.c Can't get configuration for kernel subimage 2988 102 common/cmd_bootm.c Kernel unit name specified 2989 -103 common/cmd_bootm.c Can't get kernel subimage node offset 2990 103 common/cmd_bootm.c Found configuration node 2991 104 common/cmd_bootm.c Got kernel subimage node offset 2992 -104 common/cmd_bootm.c Kernel subimage hash verification failed 2993 105 common/cmd_bootm.c Kernel subimage hash verification OK 2994 -105 common/cmd_bootm.c Kernel subimage is for unsupported architecture 2995 106 common/cmd_bootm.c Architecture check OK 2996 -106 common/cmd_bootm.c Kernel subimage has wrong type 2997 107 common/cmd_bootm.c Kernel subimage type OK 2998 -107 common/cmd_bootm.c Can't get kernel subimage data/size 2999 108 common/cmd_bootm.c Got kernel subimage data/size 3000 -108 common/cmd_bootm.c Wrong image type (not legacy, FIT) 3001 -109 common/cmd_bootm.c Can't get kernel subimage type 3002 -110 common/cmd_bootm.c Can't get kernel subimage comp 3003 -111 common/cmd_bootm.c Can't get kernel subimage os 3004 -112 common/cmd_bootm.c Can't get kernel subimage load address 3005 -113 common/cmd_bootm.c Image uncompress/copy overwrite error 3006 3007 120 common/image.c Start initial ramdisk verification 3008 -120 common/image.c Ramdisk FIT image has incorrect format 3009 121 common/image.c Ramdisk FIT image has correct format 3010 122 common/image.c No ramdisk subimage unit name, using configuration 3011 -122 common/image.c Can't get configuration for ramdisk subimage 3012 123 common/image.c Ramdisk unit name specified 3013 -124 common/image.c Can't get ramdisk subimage node offset 3014 125 common/image.c Got ramdisk subimage node offset 3015 -125 common/image.c Ramdisk subimage hash verification failed 3016 126 common/image.c Ramdisk subimage hash verification OK 3017 -126 common/image.c Ramdisk subimage for unsupported architecture 3018 127 common/image.c Architecture check OK 3019 -127 common/image.c Can't get ramdisk subimage data/size 3020 128 common/image.c Got ramdisk subimage data/size 3021 129 common/image.c Can't get ramdisk load address 3022 -129 common/image.c Got ramdisk load address 3023 3024 -130 common/cmd_doc.c Incorrect FIT image format 3025 131 common/cmd_doc.c FIT image format OK 3026 3027 -140 common/cmd_ide.c Incorrect FIT image format 3028 141 common/cmd_ide.c FIT image format OK 3029 3030 -150 common/cmd_nand.c Incorrect FIT image format 3031 151 common/cmd_nand.c FIT image format OK 3032 3033- legacy image format: 3034 CONFIG_IMAGE_FORMAT_LEGACY 3035 enables the legacy image format support in U-Boot. 3036 3037 Default: 3038 enabled if CONFIG_FIT_SIGNATURE is not defined. 3039 3040 CONFIG_DISABLE_IMAGE_LEGACY 3041 disable the legacy image format 3042 3043 This define is introduced, as the legacy image format is 3044 enabled per default for backward compatibility. 3045 3046- FIT image support: 3047 CONFIG_FIT_DISABLE_SHA256 3048 Supporting SHA256 hashes has quite an impact on binary size. 3049 For constrained systems sha256 hash support can be disabled 3050 with this option. 3051 3052 TODO(sjg@chromium.org): Adjust this option to be positive, 3053 and move it to Kconfig 3054 3055- Standalone program support: 3056 CONFIG_STANDALONE_LOAD_ADDR 3057 3058 This option defines a board specific value for the 3059 address where standalone program gets loaded, thus 3060 overwriting the architecture dependent default 3061 settings. 3062 3063- Frame Buffer Address: 3064 CONFIG_FB_ADDR 3065 3066 Define CONFIG_FB_ADDR if you want to use specific 3067 address for frame buffer. This is typically the case 3068 when using a graphics controller has separate video 3069 memory. U-Boot will then place the frame buffer at 3070 the given address instead of dynamically reserving it 3071 in system RAM by calling lcd_setmem(), which grabs 3072 the memory for the frame buffer depending on the 3073 configured panel size. 3074 3075 Please see board_init_f function. 3076 3077- Automatic software updates via TFTP server 3078 CONFIG_UPDATE_TFTP 3079 CONFIG_UPDATE_TFTP_CNT_MAX 3080 CONFIG_UPDATE_TFTP_MSEC_MAX 3081 3082 These options enable and control the auto-update feature; 3083 for a more detailed description refer to doc/README.update. 3084 3085- MTD Support (mtdparts command, UBI support) 3086 CONFIG_MTD_DEVICE 3087 3088 Adds the MTD device infrastructure from the Linux kernel. 3089 Needed for mtdparts command support. 3090 3091 CONFIG_MTD_PARTITIONS 3092 3093 Adds the MTD partitioning infrastructure from the Linux 3094 kernel. Needed for UBI support. 3095 3096- UBI support 3097 CONFIG_CMD_UBI 3098 3099 Adds commands for interacting with MTD partitions formatted 3100 with the UBI flash translation layer 3101 3102 Requires also defining CONFIG_RBTREE 3103 3104 CONFIG_UBI_SILENCE_MSG 3105 3106 Make the verbose messages from UBI stop printing. This leaves 3107 warnings and errors enabled. 3108 3109 3110 CONFIG_MTD_UBI_WL_THRESHOLD 3111 This parameter defines the maximum difference between the highest 3112 erase counter value and the lowest erase counter value of eraseblocks 3113 of UBI devices. When this threshold is exceeded, UBI starts performing 3114 wear leveling by means of moving data from eraseblock with low erase 3115 counter to eraseblocks with high erase counter. 3116 3117 The default value should be OK for SLC NAND flashes, NOR flashes and 3118 other flashes which have eraseblock life-cycle 100000 or more. 3119 However, in case of MLC NAND flashes which typically have eraseblock 3120 life-cycle less than 10000, the threshold should be lessened (e.g., 3121 to 128 or 256, although it does not have to be power of 2). 3122 3123 default: 4096 3124 3125 CONFIG_MTD_UBI_BEB_LIMIT 3126 This option specifies the maximum bad physical eraseblocks UBI 3127 expects on the MTD device (per 1024 eraseblocks). If the 3128 underlying flash does not admit of bad eraseblocks (e.g. NOR 3129 flash), this value is ignored. 3130 3131 NAND datasheets often specify the minimum and maximum NVM 3132 (Number of Valid Blocks) for the flashes' endurance lifetime. 3133 The maximum expected bad eraseblocks per 1024 eraseblocks 3134 then can be calculated as "1024 * (1 - MinNVB / MaxNVB)", 3135 which gives 20 for most NANDs (MaxNVB is basically the total 3136 count of eraseblocks on the chip). 3137 3138 To put it differently, if this value is 20, UBI will try to 3139 reserve about 1.9% of physical eraseblocks for bad blocks 3140 handling. And that will be 1.9% of eraseblocks on the entire 3141 NAND chip, not just the MTD partition UBI attaches. This means 3142 that if you have, say, a NAND flash chip admits maximum 40 bad 3143 eraseblocks, and it is split on two MTD partitions of the same 3144 size, UBI will reserve 40 eraseblocks when attaching a 3145 partition. 3146 3147 default: 20 3148 3149 CONFIG_MTD_UBI_FASTMAP 3150 Fastmap is a mechanism which allows attaching an UBI device 3151 in nearly constant time. Instead of scanning the whole MTD device it 3152 only has to locate a checkpoint (called fastmap) on the device. 3153 The on-flash fastmap contains all information needed to attach 3154 the device. Using fastmap makes only sense on large devices where 3155 attaching by scanning takes long. UBI will not automatically install 3156 a fastmap on old images, but you can set the UBI parameter 3157 CONFIG_MTD_UBI_FASTMAP_AUTOCONVERT to 1 if you want so. Please note 3158 that fastmap-enabled images are still usable with UBI implementations 3159 without fastmap support. On typical flash devices the whole fastmap 3160 fits into one PEB. UBI will reserve PEBs to hold two fastmaps. 3161 3162 CONFIG_MTD_UBI_FASTMAP_AUTOCONVERT 3163 Set this parameter to enable fastmap automatically on images 3164 without a fastmap. 3165 default: 0 3166 3167 CONFIG_MTD_UBI_FM_DEBUG 3168 Enable UBI fastmap debug 3169 default: 0 3170 3171- UBIFS support 3172 CONFIG_CMD_UBIFS 3173 3174 Adds commands for interacting with UBI volumes formatted as 3175 UBIFS. UBIFS is read-only in u-boot. 3176 3177 Requires UBI support as well as CONFIG_LZO 3178 3179 CONFIG_UBIFS_SILENCE_MSG 3180 3181 Make the verbose messages from UBIFS stop printing. This leaves 3182 warnings and errors enabled. 3183 3184- SPL framework 3185 CONFIG_SPL 3186 Enable building of SPL globally. 3187 3188 CONFIG_SPL_LDSCRIPT 3189 LDSCRIPT for linking the SPL binary. 3190 3191 CONFIG_SPL_MAX_FOOTPRINT 3192 Maximum size in memory allocated to the SPL, BSS included. 3193 When defined, the linker checks that the actual memory 3194 used by SPL from _start to __bss_end does not exceed it. 3195 CONFIG_SPL_MAX_FOOTPRINT and CONFIG_SPL_BSS_MAX_SIZE 3196 must not be both defined at the same time. 3197 3198 CONFIG_SPL_MAX_SIZE 3199 Maximum size of the SPL image (text, data, rodata, and 3200 linker lists sections), BSS excluded. 3201 When defined, the linker checks that the actual size does 3202 not exceed it. 3203 3204 CONFIG_SPL_TEXT_BASE 3205 TEXT_BASE for linking the SPL binary. 3206 3207 CONFIG_SPL_RELOC_TEXT_BASE 3208 Address to relocate to. If unspecified, this is equal to 3209 CONFIG_SPL_TEXT_BASE (i.e. no relocation is done). 3210 3211 CONFIG_SPL_BSS_START_ADDR 3212 Link address for the BSS within the SPL binary. 3213 3214 CONFIG_SPL_BSS_MAX_SIZE 3215 Maximum size in memory allocated to the SPL BSS. 3216 When defined, the linker checks that the actual memory used 3217 by SPL from __bss_start to __bss_end does not exceed it. 3218 CONFIG_SPL_MAX_FOOTPRINT and CONFIG_SPL_BSS_MAX_SIZE 3219 must not be both defined at the same time. 3220 3221 CONFIG_SPL_STACK 3222 Adress of the start of the stack SPL will use 3223 3224 CONFIG_SPL_PANIC_ON_RAW_IMAGE 3225 When defined, SPL will panic() if the image it has 3226 loaded does not have a signature. 3227 Defining this is useful when code which loads images 3228 in SPL cannot guarantee that absolutely all read errors 3229 will be caught. 3230 An example is the LPC32XX MLC NAND driver, which will 3231 consider that a completely unreadable NAND block is bad, 3232 and thus should be skipped silently. 3233 3234 CONFIG_SPL_RELOC_STACK 3235 Adress of the start of the stack SPL will use after 3236 relocation. If unspecified, this is equal to 3237 CONFIG_SPL_STACK. 3238 3239 CONFIG_SYS_SPL_MALLOC_START 3240 Starting address of the malloc pool used in SPL. 3241 When this option is set the full malloc is used in SPL and 3242 it is set up by spl_init() and before that, the simple malloc() 3243 can be used if CONFIG_SYS_MALLOC_F is defined. 3244 3245 CONFIG_SYS_SPL_MALLOC_SIZE 3246 The size of the malloc pool used in SPL. 3247 3248 CONFIG_SPL_FRAMEWORK 3249 Enable the SPL framework under common/. This framework 3250 supports MMC, NAND and YMODEM loading of U-Boot and NAND 3251 NAND loading of the Linux Kernel. 3252 3253 CONFIG_SPL_OS_BOOT 3254 Enable booting directly to an OS from SPL. 3255 See also: doc/README.falcon 3256 3257 CONFIG_SPL_DISPLAY_PRINT 3258 For ARM, enable an optional function to print more information 3259 about the running system. 3260 3261 CONFIG_SPL_INIT_MINIMAL 3262 Arch init code should be built for a very small image 3263 3264 CONFIG_SYS_MMCSD_RAW_MODE_U_BOOT_PARTITION 3265 Partition on the MMC to load U-Boot from when the MMC is being 3266 used in raw mode 3267 3268 CONFIG_SYS_MMCSD_RAW_MODE_KERNEL_SECTOR 3269 Sector to load kernel uImage from when MMC is being 3270 used in raw mode (for Falcon mode) 3271 3272 CONFIG_SYS_MMCSD_RAW_MODE_ARGS_SECTOR, 3273 CONFIG_SYS_MMCSD_RAW_MODE_ARGS_SECTORS 3274 Sector and number of sectors to load kernel argument 3275 parameters from when MMC is being used in raw mode 3276 (for falcon mode) 3277 3278 CONFIG_SYS_MMCSD_FS_BOOT_PARTITION 3279 Partition on the MMC to load U-Boot from when the MMC is being 3280 used in fs mode 3281 3282 CONFIG_SPL_FS_LOAD_PAYLOAD_NAME 3283 Filename to read to load U-Boot when reading from filesystem 3284 3285 CONFIG_SPL_FS_LOAD_KERNEL_NAME 3286 Filename to read to load kernel uImage when reading 3287 from filesystem (for Falcon mode) 3288 3289 CONFIG_SPL_FS_LOAD_ARGS_NAME 3290 Filename to read to load kernel argument parameters 3291 when reading from filesystem (for Falcon mode) 3292 3293 CONFIG_SPL_MPC83XX_WAIT_FOR_NAND 3294 Set this for NAND SPL on PPC mpc83xx targets, so that 3295 start.S waits for the rest of the SPL to load before 3296 continuing (the hardware starts execution after just 3297 loading the first page rather than the full 4K). 3298 3299 CONFIG_SPL_SKIP_RELOCATE 3300 Avoid SPL relocation 3301 3302 CONFIG_SPL_NAND_BASE 3303 Include nand_base.c in the SPL. Requires 3304 CONFIG_SPL_NAND_DRIVERS. 3305 3306 CONFIG_SPL_NAND_DRIVERS 3307 SPL uses normal NAND drivers, not minimal drivers. 3308 3309 CONFIG_SPL_NAND_ECC 3310 Include standard software ECC in the SPL 3311 3312 CONFIG_SPL_NAND_SIMPLE 3313 Support for NAND boot using simple NAND drivers that 3314 expose the cmd_ctrl() interface. 3315 3316 CONFIG_SPL_UBI 3317 Support for a lightweight UBI (fastmap) scanner and 3318 loader 3319 3320 CONFIG_SPL_NAND_RAW_ONLY 3321 Support to boot only raw u-boot.bin images. Use this only 3322 if you need to save space. 3323 3324 CONFIG_SPL_COMMON_INIT_DDR 3325 Set for common ddr init with serial presence detect in 3326 SPL binary. 3327 3328 CONFIG_SYS_NAND_5_ADDR_CYCLE, CONFIG_SYS_NAND_PAGE_COUNT, 3329 CONFIG_SYS_NAND_PAGE_SIZE, CONFIG_SYS_NAND_OOBSIZE, 3330 CONFIG_SYS_NAND_BLOCK_SIZE, CONFIG_SYS_NAND_BAD_BLOCK_POS, 3331 CONFIG_SYS_NAND_ECCPOS, CONFIG_SYS_NAND_ECCSIZE, 3332 CONFIG_SYS_NAND_ECCBYTES 3333 Defines the size and behavior of the NAND that SPL uses 3334 to read U-Boot 3335 3336 CONFIG_SPL_NAND_BOOT 3337 Add support NAND boot 3338 3339 CONFIG_SYS_NAND_U_BOOT_OFFS 3340 Location in NAND to read U-Boot from 3341 3342 CONFIG_SYS_NAND_U_BOOT_DST 3343 Location in memory to load U-Boot to 3344 3345 CONFIG_SYS_NAND_U_BOOT_SIZE 3346 Size of image to load 3347 3348 CONFIG_SYS_NAND_U_BOOT_START 3349 Entry point in loaded image to jump to 3350 3351 CONFIG_SYS_NAND_HW_ECC_OOBFIRST 3352 Define this if you need to first read the OOB and then the 3353 data. This is used, for example, on davinci platforms. 3354 3355 CONFIG_SPL_OMAP3_ID_NAND 3356 Support for an OMAP3-specific set of functions to return the 3357 ID and MFR of the first attached NAND chip, if present. 3358 3359 CONFIG_SPL_RAM_DEVICE 3360 Support for running image already present in ram, in SPL binary 3361 3362 CONFIG_SPL_PAD_TO 3363 Image offset to which the SPL should be padded before appending 3364 the SPL payload. By default, this is defined as 3365 CONFIG_SPL_MAX_SIZE, or 0 if CONFIG_SPL_MAX_SIZE is undefined. 3366 CONFIG_SPL_PAD_TO must be either 0, meaning to append the SPL 3367 payload without any padding, or >= CONFIG_SPL_MAX_SIZE. 3368 3369 CONFIG_SPL_TARGET 3370 Final target image containing SPL and payload. Some SPLs 3371 use an arch-specific makefile fragment instead, for 3372 example if more than one image needs to be produced. 3373 3374 CONFIG_FIT_SPL_PRINT 3375 Printing information about a FIT image adds quite a bit of 3376 code to SPL. So this is normally disabled in SPL. Use this 3377 option to re-enable it. This will affect the output of the 3378 bootm command when booting a FIT image. 3379 3380- TPL framework 3381 CONFIG_TPL 3382 Enable building of TPL globally. 3383 3384 CONFIG_TPL_PAD_TO 3385 Image offset to which the TPL should be padded before appending 3386 the TPL payload. By default, this is defined as 3387 CONFIG_SPL_MAX_SIZE, or 0 if CONFIG_SPL_MAX_SIZE is undefined. 3388 CONFIG_SPL_PAD_TO must be either 0, meaning to append the SPL 3389 payload without any padding, or >= CONFIG_SPL_MAX_SIZE. 3390 3391- Interrupt support (PPC): 3392 3393 There are common interrupt_init() and timer_interrupt() 3394 for all PPC archs. interrupt_init() calls interrupt_init_cpu() 3395 for CPU specific initialization. interrupt_init_cpu() 3396 should set decrementer_count to appropriate value. If 3397 CPU resets decrementer automatically after interrupt 3398 (ppc4xx) it should set decrementer_count to zero. 3399 timer_interrupt() calls timer_interrupt_cpu() for CPU 3400 specific handling. If board has watchdog / status_led 3401 / other_activity_monitor it works automatically from 3402 general timer_interrupt(). 3403 3404 3405Board initialization settings: 3406------------------------------ 3407 3408During Initialization u-boot calls a number of board specific functions 3409to allow the preparation of board specific prerequisites, e.g. pin setup 3410before drivers are initialized. To enable these callbacks the 3411following configuration macros have to be defined. Currently this is 3412architecture specific, so please check arch/your_architecture/lib/board.c 3413typically in board_init_f() and board_init_r(). 3414 3415- CONFIG_BOARD_EARLY_INIT_F: Call board_early_init_f() 3416- CONFIG_BOARD_EARLY_INIT_R: Call board_early_init_r() 3417- CONFIG_BOARD_LATE_INIT: Call board_late_init() 3418- CONFIG_BOARD_POSTCLK_INIT: Call board_postclk_init() 3419 3420Configuration Settings: 3421----------------------- 3422 3423- CONFIG_SYS_SUPPORT_64BIT_DATA: Defined automatically if compiled as 64-bit. 3424 Optionally it can be defined to support 64-bit memory commands. 3425 3426- CONFIG_SYS_LONGHELP: Defined when you want long help messages included; 3427 undefine this when you're short of memory. 3428 3429- CONFIG_SYS_HELP_CMD_WIDTH: Defined when you want to override the default 3430 width of the commands listed in the 'help' command output. 3431 3432- CONFIG_SYS_PROMPT: This is what U-Boot prints on the console to 3433 prompt for user input. 3434 3435- CONFIG_SYS_CBSIZE: Buffer size for input from the Console 3436 3437- CONFIG_SYS_PBSIZE: Buffer size for Console output 3438 3439- CONFIG_SYS_MAXARGS: max. Number of arguments accepted for monitor commands 3440 3441- CONFIG_SYS_BARGSIZE: Buffer size for Boot Arguments which are passed to 3442 the application (usually a Linux kernel) when it is 3443 booted 3444 3445- CONFIG_SYS_BAUDRATE_TABLE: 3446 List of legal baudrate settings for this board. 3447 3448- CONFIG_SYS_MEMTEST_START, CONFIG_SYS_MEMTEST_END: 3449 Begin and End addresses of the area used by the 3450 simple memory test. 3451 3452- CONFIG_SYS_ALT_MEMTEST: 3453 Enable an alternate, more extensive memory test. 3454 3455- CONFIG_SYS_MEMTEST_SCRATCH: 3456 Scratch address used by the alternate memory test 3457 You only need to set this if address zero isn't writeable 3458 3459- CONFIG_SYS_MEM_RESERVE_SECURE 3460 Only implemented for ARMv8 for now. 3461 If defined, the size of CONFIG_SYS_MEM_RESERVE_SECURE memory 3462 is substracted from total RAM and won't be reported to OS. 3463 This memory can be used as secure memory. A variable 3464 gd->arch.secure_ram is used to track the location. In systems 3465 the RAM base is not zero, or RAM is divided into banks, 3466 this variable needs to be recalcuated to get the address. 3467 3468- CONFIG_SYS_MEM_TOP_HIDE: 3469 If CONFIG_SYS_MEM_TOP_HIDE is defined in the board config header, 3470 this specified memory area will get subtracted from the top 3471 (end) of RAM and won't get "touched" at all by U-Boot. By 3472 fixing up gd->ram_size the Linux kernel should gets passed 3473 the now "corrected" memory size and won't touch it either. 3474 This should work for arch/ppc and arch/powerpc. Only Linux 3475 board ports in arch/powerpc with bootwrapper support that 3476 recalculate the memory size from the SDRAM controller setup 3477 will have to get fixed in Linux additionally. 3478 3479 This option can be used as a workaround for the 440EPx/GRx 3480 CHIP 11 errata where the last 256 bytes in SDRAM shouldn't 3481 be touched. 3482 3483 WARNING: Please make sure that this value is a multiple of 3484 the Linux page size (normally 4k). If this is not the case, 3485 then the end address of the Linux memory will be located at a 3486 non page size aligned address and this could cause major 3487 problems. 3488 3489- CONFIG_SYS_LOADS_BAUD_CHANGE: 3490 Enable temporary baudrate change while serial download 3491 3492- CONFIG_SYS_SDRAM_BASE: 3493 Physical start address of SDRAM. _Must_ be 0 here. 3494 3495- CONFIG_SYS_FLASH_BASE: 3496 Physical start address of Flash memory. 3497 3498- CONFIG_SYS_MONITOR_BASE: 3499 Physical start address of boot monitor code (set by 3500 make config files to be same as the text base address 3501 (CONFIG_SYS_TEXT_BASE) used when linking) - same as 3502 CONFIG_SYS_FLASH_BASE when booting from flash. 3503 3504- CONFIG_SYS_MONITOR_LEN: 3505 Size of memory reserved for monitor code, used to 3506 determine _at_compile_time_ (!) if the environment is 3507 embedded within the U-Boot image, or in a separate 3508 flash sector. 3509 3510- CONFIG_SYS_MALLOC_LEN: 3511 Size of DRAM reserved for malloc() use. 3512 3513- CONFIG_SYS_MALLOC_F_LEN 3514 Size of the malloc() pool for use before relocation. If 3515 this is defined, then a very simple malloc() implementation 3516 will become available before relocation. The address is just 3517 below the global data, and the stack is moved down to make 3518 space. 3519 3520 This feature allocates regions with increasing addresses 3521 within the region. calloc() is supported, but realloc() 3522 is not available. free() is supported but does nothing. 3523 The memory will be freed (or in fact just forgotten) when 3524 U-Boot relocates itself. 3525 3526- CONFIG_SYS_MALLOC_SIMPLE 3527 Provides a simple and small malloc() and calloc() for those 3528 boards which do not use the full malloc in SPL (which is 3529 enabled with CONFIG_SYS_SPL_MALLOC_START). 3530 3531- CONFIG_SYS_NONCACHED_MEMORY: 3532 Size of non-cached memory area. This area of memory will be 3533 typically located right below the malloc() area and mapped 3534 uncached in the MMU. This is useful for drivers that would 3535 otherwise require a lot of explicit cache maintenance. For 3536 some drivers it's also impossible to properly maintain the 3537 cache. For example if the regions that need to be flushed 3538 are not a multiple of the cache-line size, *and* padding 3539 cannot be allocated between the regions to align them (i.e. 3540 if the HW requires a contiguous array of regions, and the 3541 size of each region is not cache-aligned), then a flush of 3542 one region may result in overwriting data that hardware has 3543 written to another region in the same cache-line. This can 3544 happen for example in network drivers where descriptors for 3545 buffers are typically smaller than the CPU cache-line (e.g. 3546 16 bytes vs. 32 or 64 bytes). 3547 3548 Non-cached memory is only supported on 32-bit ARM at present. 3549 3550- CONFIG_SYS_BOOTM_LEN: 3551 Normally compressed uImages are limited to an 3552 uncompressed size of 8 MBytes. If this is not enough, 3553 you can define CONFIG_SYS_BOOTM_LEN in your board config file 3554 to adjust this setting to your needs. 3555 3556- CONFIG_SYS_BOOTMAPSZ: 3557 Maximum size of memory mapped by the startup code of 3558 the Linux kernel; all data that must be processed by 3559 the Linux kernel (bd_info, boot arguments, FDT blob if 3560 used) must be put below this limit, unless "bootm_low" 3561 environment variable is defined and non-zero. In such case 3562 all data for the Linux kernel must be between "bootm_low" 3563 and "bootm_low" + CONFIG_SYS_BOOTMAPSZ. The environment 3564 variable "bootm_mapsize" will override the value of 3565 CONFIG_SYS_BOOTMAPSZ. If CONFIG_SYS_BOOTMAPSZ is undefined, 3566 then the value in "bootm_size" will be used instead. 3567 3568- CONFIG_SYS_BOOT_RAMDISK_HIGH: 3569 Enable initrd_high functionality. If defined then the 3570 initrd_high feature is enabled and the bootm ramdisk subcommand 3571 is enabled. 3572 3573- CONFIG_SYS_BOOT_GET_CMDLINE: 3574 Enables allocating and saving kernel cmdline in space between 3575 "bootm_low" and "bootm_low" + BOOTMAPSZ. 3576 3577- CONFIG_SYS_BOOT_GET_KBD: 3578 Enables allocating and saving a kernel copy of the bd_info in 3579 space between "bootm_low" and "bootm_low" + BOOTMAPSZ. 3580 3581- CONFIG_SYS_MAX_FLASH_BANKS: 3582 Max number of Flash memory banks 3583 3584- CONFIG_SYS_MAX_FLASH_SECT: 3585 Max number of sectors on a Flash chip 3586 3587- CONFIG_SYS_FLASH_ERASE_TOUT: 3588 Timeout for Flash erase operations (in ms) 3589 3590- CONFIG_SYS_FLASH_WRITE_TOUT: 3591 Timeout for Flash write operations (in ms) 3592 3593- CONFIG_SYS_FLASH_LOCK_TOUT 3594 Timeout for Flash set sector lock bit operation (in ms) 3595 3596- CONFIG_SYS_FLASH_UNLOCK_TOUT 3597 Timeout for Flash clear lock bits operation (in ms) 3598 3599- CONFIG_SYS_FLASH_PROTECTION 3600 If defined, hardware flash sectors protection is used 3601 instead of U-Boot software protection. 3602 3603- CONFIG_SYS_DIRECT_FLASH_TFTP: 3604 3605 Enable TFTP transfers directly to flash memory; 3606 without this option such a download has to be 3607 performed in two steps: (1) download to RAM, and (2) 3608 copy from RAM to flash. 3609 3610 The two-step approach is usually more reliable, since 3611 you can check if the download worked before you erase 3612 the flash, but in some situations (when system RAM is 3613 too limited to allow for a temporary copy of the 3614 downloaded image) this option may be very useful. 3615 3616- CONFIG_SYS_FLASH_CFI: 3617 Define if the flash driver uses extra elements in the 3618 common flash structure for storing flash geometry. 3619 3620- CONFIG_FLASH_CFI_DRIVER 3621 This option also enables the building of the cfi_flash driver 3622 in the drivers directory 3623 3624- CONFIG_FLASH_CFI_MTD 3625 This option enables the building of the cfi_mtd driver 3626 in the drivers directory. The driver exports CFI flash 3627 to the MTD layer. 3628 3629- CONFIG_SYS_FLASH_USE_BUFFER_WRITE 3630 Use buffered writes to flash. 3631 3632- CONFIG_FLASH_SPANSION_S29WS_N 3633 s29ws-n MirrorBit flash has non-standard addresses for buffered 3634 write commands. 3635 3636- CONFIG_SYS_FLASH_QUIET_TEST 3637 If this option is defined, the common CFI flash doesn't 3638 print it's warning upon not recognized FLASH banks. This 3639 is useful, if some of the configured banks are only 3640 optionally available. 3641 3642- CONFIG_FLASH_SHOW_PROGRESS 3643 If defined (must be an integer), print out countdown 3644 digits and dots. Recommended value: 45 (9..1) for 80 3645 column displays, 15 (3..1) for 40 column displays. 3646 3647- CONFIG_FLASH_VERIFY 3648 If defined, the content of the flash (destination) is compared 3649 against the source after the write operation. An error message 3650 will be printed when the contents are not identical. 3651 Please note that this option is useless in nearly all cases, 3652 since such flash programming errors usually are detected earlier 3653 while unprotecting/erasing/programming. Please only enable 3654 this option if you really know what you are doing. 3655 3656- CONFIG_SYS_RX_ETH_BUFFER: 3657 Defines the number of Ethernet receive buffers. On some 3658 Ethernet controllers it is recommended to set this value 3659 to 8 or even higher (EEPRO100 or 405 EMAC), since all 3660 buffers can be full shortly after enabling the interface 3661 on high Ethernet traffic. 3662 Defaults to 4 if not defined. 3663 3664- CONFIG_ENV_MAX_ENTRIES 3665 3666 Maximum number of entries in the hash table that is used 3667 internally to store the environment settings. The default 3668 setting is supposed to be generous and should work in most 3669 cases. This setting can be used to tune behaviour; see 3670 lib/hashtable.c for details. 3671 3672- CONFIG_ENV_FLAGS_LIST_DEFAULT 3673- CONFIG_ENV_FLAGS_LIST_STATIC 3674 Enable validation of the values given to environment variables when 3675 calling env set. Variables can be restricted to only decimal, 3676 hexadecimal, or boolean. If CONFIG_CMD_NET is also defined, 3677 the variables can also be restricted to IP address or MAC address. 3678 3679 The format of the list is: 3680 type_attribute = [s|d|x|b|i|m] 3681 access_attribute = [a|r|o|c] 3682 attributes = type_attribute[access_attribute] 3683 entry = variable_name[:attributes] 3684 list = entry[,list] 3685 3686 The type attributes are: 3687 s - String (default) 3688 d - Decimal 3689 x - Hexadecimal 3690 b - Boolean ([1yYtT|0nNfF]) 3691 i - IP address 3692 m - MAC address 3693 3694 The access attributes are: 3695 a - Any (default) 3696 r - Read-only 3697 o - Write-once 3698 c - Change-default 3699 3700 - CONFIG_ENV_FLAGS_LIST_DEFAULT 3701 Define this to a list (string) to define the ".flags" 3702 environment variable in the default or embedded environment. 3703 3704 - CONFIG_ENV_FLAGS_LIST_STATIC 3705 Define this to a list (string) to define validation that 3706 should be done if an entry is not found in the ".flags" 3707 environment variable. To override a setting in the static 3708 list, simply add an entry for the same variable name to the 3709 ".flags" variable. 3710 3711 If CONFIG_REGEX is defined, the variable_name above is evaluated as a 3712 regular expression. This allows multiple variables to define the same 3713 flags without explicitly listing them for each variable. 3714 3715- CONFIG_ENV_ACCESS_IGNORE_FORCE 3716 If defined, don't allow the -f switch to env set override variable 3717 access flags. 3718 3719- CONFIG_OMAP_PLATFORM_RESET_TIME_MAX_USEC (OMAP only) 3720 This is set by OMAP boards for the max time that reset should 3721 be asserted. See doc/README.omap-reset-time for details on how 3722 the value can be calculated on a given board. 3723 3724- CONFIG_USE_STDINT 3725 If stdint.h is available with your toolchain you can define this 3726 option to enable it. You can provide option 'USE_STDINT=1' when 3727 building U-Boot to enable this. 3728 3729The following definitions that deal with the placement and management 3730of environment data (variable area); in general, we support the 3731following configurations: 3732 3733- CONFIG_BUILD_ENVCRC: 3734 3735 Builds up envcrc with the target environment so that external utils 3736 may easily extract it and embed it in final U-Boot images. 3737 3738- CONFIG_ENV_IS_IN_FLASH: 3739 3740 Define this if the environment is in flash memory. 3741 3742 a) The environment occupies one whole flash sector, which is 3743 "embedded" in the text segment with the U-Boot code. This 3744 happens usually with "bottom boot sector" or "top boot 3745 sector" type flash chips, which have several smaller 3746 sectors at the start or the end. For instance, such a 3747 layout can have sector sizes of 8, 2x4, 16, Nx32 kB. In 3748 such a case you would place the environment in one of the 3749 4 kB sectors - with U-Boot code before and after it. With 3750 "top boot sector" type flash chips, you would put the 3751 environment in one of the last sectors, leaving a gap 3752 between U-Boot and the environment. 3753 3754 - CONFIG_ENV_OFFSET: 3755 3756 Offset of environment data (variable area) to the 3757 beginning of flash memory; for instance, with bottom boot 3758 type flash chips the second sector can be used: the offset 3759 for this sector is given here. 3760 3761 CONFIG_ENV_OFFSET is used relative to CONFIG_SYS_FLASH_BASE. 3762 3763 - CONFIG_ENV_ADDR: 3764 3765 This is just another way to specify the start address of 3766 the flash sector containing the environment (instead of 3767 CONFIG_ENV_OFFSET). 3768 3769 - CONFIG_ENV_SECT_SIZE: 3770 3771 Size of the sector containing the environment. 3772 3773 3774 b) Sometimes flash chips have few, equal sized, BIG sectors. 3775 In such a case you don't want to spend a whole sector for 3776 the environment. 3777 3778 - CONFIG_ENV_SIZE: 3779 3780 If you use this in combination with CONFIG_ENV_IS_IN_FLASH 3781 and CONFIG_ENV_SECT_SIZE, you can specify to use only a part 3782 of this flash sector for the environment. This saves 3783 memory for the RAM copy of the environment. 3784 3785 It may also save flash memory if you decide to use this 3786 when your environment is "embedded" within U-Boot code, 3787 since then the remainder of the flash sector could be used 3788 for U-Boot code. It should be pointed out that this is 3789 STRONGLY DISCOURAGED from a robustness point of view: 3790 updating the environment in flash makes it always 3791 necessary to erase the WHOLE sector. If something goes 3792 wrong before the contents has been restored from a copy in 3793 RAM, your target system will be dead. 3794 3795 - CONFIG_ENV_ADDR_REDUND 3796 CONFIG_ENV_SIZE_REDUND 3797 3798 These settings describe a second storage area used to hold 3799 a redundant copy of the environment data, so that there is 3800 a valid backup copy in case there is a power failure during 3801 a "saveenv" operation. 3802 3803BE CAREFUL! Any changes to the flash layout, and some changes to the 3804source code will make it necessary to adapt <board>/u-boot.lds* 3805accordingly! 3806 3807 3808- CONFIG_ENV_IS_IN_NVRAM: 3809 3810 Define this if you have some non-volatile memory device 3811 (NVRAM, battery buffered SRAM) which you want to use for the 3812 environment. 3813 3814 - CONFIG_ENV_ADDR: 3815 - CONFIG_ENV_SIZE: 3816 3817 These two #defines are used to determine the memory area you 3818 want to use for environment. It is assumed that this memory 3819 can just be read and written to, without any special 3820 provision. 3821 3822BE CAREFUL! The first access to the environment happens quite early 3823in U-Boot initialization (when we try to get the setting of for the 3824console baudrate). You *MUST* have mapped your NVRAM area then, or 3825U-Boot will hang. 3826 3827Please note that even with NVRAM we still use a copy of the 3828environment in RAM: we could work on NVRAM directly, but we want to 3829keep settings there always unmodified except somebody uses "saveenv" 3830to save the current settings. 3831 3832 3833- CONFIG_ENV_IS_IN_EEPROM: 3834 3835 Use this if you have an EEPROM or similar serial access 3836 device and a driver for it. 3837 3838 - CONFIG_ENV_OFFSET: 3839 - CONFIG_ENV_SIZE: 3840 3841 These two #defines specify the offset and size of the 3842 environment area within the total memory of your EEPROM. 3843 3844 - CONFIG_SYS_I2C_EEPROM_ADDR: 3845 If defined, specified the chip address of the EEPROM device. 3846 The default address is zero. 3847 3848 - CONFIG_SYS_I2C_EEPROM_BUS: 3849 If defined, specified the i2c bus of the EEPROM device. 3850 3851 - CONFIG_SYS_EEPROM_PAGE_WRITE_BITS: 3852 If defined, the number of bits used to address bytes in a 3853 single page in the EEPROM device. A 64 byte page, for example 3854 would require six bits. 3855 3856 - CONFIG_SYS_EEPROM_PAGE_WRITE_DELAY_MS: 3857 If defined, the number of milliseconds to delay between 3858 page writes. The default is zero milliseconds. 3859 3860 - CONFIG_SYS_I2C_EEPROM_ADDR_LEN: 3861 The length in bytes of the EEPROM memory array address. Note 3862 that this is NOT the chip address length! 3863 3864 - CONFIG_SYS_I2C_EEPROM_ADDR_OVERFLOW: 3865 EEPROM chips that implement "address overflow" are ones 3866 like Catalyst 24WC04/08/16 which has 9/10/11 bits of 3867 address and the extra bits end up in the "chip address" bit 3868 slots. This makes a 24WC08 (1Kbyte) chip look like four 256 3869 byte chips. 3870 3871 Note that we consider the length of the address field to 3872 still be one byte because the extra address bits are hidden 3873 in the chip address. 3874 3875 - CONFIG_SYS_EEPROM_SIZE: 3876 The size in bytes of the EEPROM device. 3877 3878 - CONFIG_ENV_EEPROM_IS_ON_I2C 3879 define this, if you have I2C and SPI activated, and your 3880 EEPROM, which holds the environment, is on the I2C bus. 3881 3882 - CONFIG_I2C_ENV_EEPROM_BUS 3883 if you have an Environment on an EEPROM reached over 3884 I2C muxes, you can define here, how to reach this 3885 EEPROM. For example: 3886 3887 #define CONFIG_I2C_ENV_EEPROM_BUS 1 3888 3889 EEPROM which holds the environment, is reached over 3890 a pca9547 i2c mux with address 0x70, channel 3. 3891 3892- CONFIG_ENV_IS_IN_DATAFLASH: 3893 3894 Define this if you have a DataFlash memory device which you 3895 want to use for the environment. 3896 3897 - CONFIG_ENV_OFFSET: 3898 - CONFIG_ENV_ADDR: 3899 - CONFIG_ENV_SIZE: 3900 3901 These three #defines specify the offset and size of the 3902 environment area within the total memory of your DataFlash placed 3903 at the specified address. 3904 3905- CONFIG_ENV_IS_IN_SPI_FLASH: 3906 3907 Define this if you have a SPI Flash memory device which you 3908 want to use for the environment. 3909 3910 - CONFIG_ENV_OFFSET: 3911 - CONFIG_ENV_SIZE: 3912 3913 These two #defines specify the offset and size of the 3914 environment area within the SPI Flash. CONFIG_ENV_OFFSET must be 3915 aligned to an erase sector boundary. 3916 3917 - CONFIG_ENV_SECT_SIZE: 3918 3919 Define the SPI flash's sector size. 3920 3921 - CONFIG_ENV_OFFSET_REDUND (optional): 3922 3923 This setting describes a second storage area of CONFIG_ENV_SIZE 3924 size used to hold a redundant copy of the environment data, so 3925 that there is a valid backup copy in case there is a power failure 3926 during a "saveenv" operation. CONFIG_ENV_OFFSET_REDUND must be 3927 aligned to an erase sector boundary. 3928 3929 - CONFIG_ENV_SPI_BUS (optional): 3930 - CONFIG_ENV_SPI_CS (optional): 3931 3932 Define the SPI bus and chip select. If not defined they will be 0. 3933 3934 - CONFIG_ENV_SPI_MAX_HZ (optional): 3935 3936 Define the SPI max work clock. If not defined then use 1MHz. 3937 3938 - CONFIG_ENV_SPI_MODE (optional): 3939 3940 Define the SPI work mode. If not defined then use SPI_MODE_3. 3941 3942- CONFIG_ENV_IS_IN_REMOTE: 3943 3944 Define this if you have a remote memory space which you 3945 want to use for the local device's environment. 3946 3947 - CONFIG_ENV_ADDR: 3948 - CONFIG_ENV_SIZE: 3949 3950 These two #defines specify the address and size of the 3951 environment area within the remote memory space. The 3952 local device can get the environment from remote memory 3953 space by SRIO or PCIE links. 3954 3955BE CAREFUL! For some special cases, the local device can not use 3956"saveenv" command. For example, the local device will get the 3957environment stored in a remote NOR flash by SRIO or PCIE link, 3958but it can not erase, write this NOR flash by SRIO or PCIE interface. 3959 3960- CONFIG_ENV_IS_IN_NAND: 3961 3962 Define this if you have a NAND device which you want to use 3963 for the environment. 3964 3965 - CONFIG_ENV_OFFSET: 3966 - CONFIG_ENV_SIZE: 3967 3968 These two #defines specify the offset and size of the environment 3969 area within the first NAND device. CONFIG_ENV_OFFSET must be 3970 aligned to an erase block boundary. 3971 3972 - CONFIG_ENV_OFFSET_REDUND (optional): 3973 3974 This setting describes a second storage area of CONFIG_ENV_SIZE 3975 size used to hold a redundant copy of the environment data, so 3976 that there is a valid backup copy in case there is a power failure 3977 during a "saveenv" operation. CONFIG_ENV_OFFSET_REDUND must be 3978 aligned to an erase block boundary. 3979 3980 - CONFIG_ENV_RANGE (optional): 3981 3982 Specifies the length of the region in which the environment 3983 can be written. This should be a multiple of the NAND device's 3984 block size. Specifying a range with more erase blocks than 3985 are needed to hold CONFIG_ENV_SIZE allows bad blocks within 3986 the range to be avoided. 3987 3988 - CONFIG_ENV_OFFSET_OOB (optional): 3989 3990 Enables support for dynamically retrieving the offset of the 3991 environment from block zero's out-of-band data. The 3992 "nand env.oob" command can be used to record this offset. 3993 Currently, CONFIG_ENV_OFFSET_REDUND is not supported when 3994 using CONFIG_ENV_OFFSET_OOB. 3995 3996- CONFIG_NAND_ENV_DST 3997 3998 Defines address in RAM to which the nand_spl code should copy the 3999 environment. If redundant environment is used, it will be copied to 4000 CONFIG_NAND_ENV_DST + CONFIG_ENV_SIZE. 4001 4002- CONFIG_ENV_IS_IN_UBI: 4003 4004 Define this if you have an UBI volume that you want to use for the 4005 environment. This has the benefit of wear-leveling the environment 4006 accesses, which is important on NAND. 4007 4008 - CONFIG_ENV_UBI_PART: 4009 4010 Define this to a string that is the mtd partition containing the UBI. 4011 4012 - CONFIG_ENV_UBI_VOLUME: 4013 4014 Define this to the name of the volume that you want to store the 4015 environment in. 4016 4017 - CONFIG_ENV_UBI_VOLUME_REDUND: 4018 4019 Define this to the name of another volume to store a second copy of 4020 the environment in. This will enable redundant environments in UBI. 4021 It is assumed that both volumes are in the same MTD partition. 4022 4023 - CONFIG_UBI_SILENCE_MSG 4024 - CONFIG_UBIFS_SILENCE_MSG 4025 4026 You will probably want to define these to avoid a really noisy system 4027 when storing the env in UBI. 4028 4029- CONFIG_ENV_IS_IN_FAT: 4030 Define this if you want to use the FAT file system for the environment. 4031 4032 - FAT_ENV_INTERFACE: 4033 4034 Define this to a string that is the name of the block device. 4035 4036 - FAT_ENV_DEVICE_AND_PART: 4037 4038 Define this to a string to specify the partition of the device. It can 4039 be as following: 4040 4041 "D:P", "D:0", "D", "D:" or "D:auto" (D, P are integers. And P >= 1) 4042 - "D:P": device D partition P. Error occurs if device D has no 4043 partition table. 4044 - "D:0": device D. 4045 - "D" or "D:": device D partition 1 if device D has partition 4046 table, or the whole device D if has no partition 4047 table. 4048 - "D:auto": first partition in device D with bootable flag set. 4049 If none, first valid partition in device D. If no 4050 partition table then means device D. 4051 4052 - FAT_ENV_FILE: 4053 4054 It's a string of the FAT file name. This file use to store the 4055 environment. 4056 4057 - CONFIG_FAT_WRITE: 4058 This should be defined. Otherwise it cannot save the environment file. 4059 4060- CONFIG_ENV_IS_IN_MMC: 4061 4062 Define this if you have an MMC device which you want to use for the 4063 environment. 4064 4065 - CONFIG_SYS_MMC_ENV_DEV: 4066 4067 Specifies which MMC device the environment is stored in. 4068 4069 - CONFIG_SYS_MMC_ENV_PART (optional): 4070 4071 Specifies which MMC partition the environment is stored in. If not 4072 set, defaults to partition 0, the user area. Common values might be 4073 1 (first MMC boot partition), 2 (second MMC boot partition). 4074 4075 - CONFIG_ENV_OFFSET: 4076 - CONFIG_ENV_SIZE: 4077 4078 These two #defines specify the offset and size of the environment 4079 area within the specified MMC device. 4080 4081 If offset is positive (the usual case), it is treated as relative to 4082 the start of the MMC partition. If offset is negative, it is treated 4083 as relative to the end of the MMC partition. This can be useful if 4084 your board may be fitted with different MMC devices, which have 4085 different sizes for the MMC partitions, and you always want the 4086 environment placed at the very end of the partition, to leave the 4087 maximum possible space before it, to store other data. 4088 4089 These two values are in units of bytes, but must be aligned to an 4090 MMC sector boundary. 4091 4092 - CONFIG_ENV_OFFSET_REDUND (optional): 4093 4094 Specifies a second storage area, of CONFIG_ENV_SIZE size, used to 4095 hold a redundant copy of the environment data. This provides a 4096 valid backup copy in case the other copy is corrupted, e.g. due 4097 to a power failure during a "saveenv" operation. 4098 4099 This value may also be positive or negative; this is handled in the 4100 same way as CONFIG_ENV_OFFSET. 4101 4102 This value is also in units of bytes, but must also be aligned to 4103 an MMC sector boundary. 4104 4105 - CONFIG_ENV_SIZE_REDUND (optional): 4106 4107 This value need not be set, even when CONFIG_ENV_OFFSET_REDUND is 4108 set. If this value is set, it must be set to the same value as 4109 CONFIG_ENV_SIZE. 4110 4111- CONFIG_SYS_SPI_INIT_OFFSET 4112 4113 Defines offset to the initial SPI buffer area in DPRAM. The 4114 area is used at an early stage (ROM part) if the environment 4115 is configured to reside in the SPI EEPROM: We need a 520 byte 4116 scratch DPRAM area. It is used between the two initialization 4117 calls (spi_init_f() and spi_init_r()). A value of 0xB00 seems 4118 to be a good choice since it makes it far enough from the 4119 start of the data area as well as from the stack pointer. 4120 4121Please note that the environment is read-only until the monitor 4122has been relocated to RAM and a RAM copy of the environment has been 4123created; also, when using EEPROM you will have to use getenv_f() 4124until then to read environment variables. 4125 4126The environment is protected by a CRC32 checksum. Before the monitor 4127is relocated into RAM, as a result of a bad CRC you will be working 4128with the compiled-in default environment - *silently*!!! [This is 4129necessary, because the first environment variable we need is the 4130"baudrate" setting for the console - if we have a bad CRC, we don't 4131have any device yet where we could complain.] 4132 4133Note: once the monitor has been relocated, then it will complain if 4134the default environment is used; a new CRC is computed as soon as you 4135use the "saveenv" command to store a valid environment. 4136 4137- CONFIG_SYS_FAULT_ECHO_LINK_DOWN: 4138 Echo the inverted Ethernet link state to the fault LED. 4139 4140 Note: If this option is active, then CONFIG_SYS_FAULT_MII_ADDR 4141 also needs to be defined. 4142 4143- CONFIG_SYS_FAULT_MII_ADDR: 4144 MII address of the PHY to check for the Ethernet link state. 4145 4146- CONFIG_NS16550_MIN_FUNCTIONS: 4147 Define this if you desire to only have use of the NS16550_init 4148 and NS16550_putc functions for the serial driver located at 4149 drivers/serial/ns16550.c. This option is useful for saving 4150 space for already greatly restricted images, including but not 4151 limited to NAND_SPL configurations. 4152 4153- CONFIG_DISPLAY_BOARDINFO 4154 Display information about the board that U-Boot is running on 4155 when U-Boot starts up. The board function checkboard() is called 4156 to do this. 4157 4158- CONFIG_DISPLAY_BOARDINFO_LATE 4159 Similar to the previous option, but display this information 4160 later, once stdio is running and output goes to the LCD, if 4161 present. 4162 4163- CONFIG_BOARD_SIZE_LIMIT: 4164 Maximum size of the U-Boot image. When defined, the 4165 build system checks that the actual size does not 4166 exceed it. 4167 4168Low Level (hardware related) configuration options: 4169--------------------------------------------------- 4170 4171- CONFIG_SYS_CACHELINE_SIZE: 4172 Cache Line Size of the CPU. 4173 4174- CONFIG_SYS_DEFAULT_IMMR: 4175 Default address of the IMMR after system reset. 4176 4177 Needed on some 8260 systems (MPC8260ADS, PQ2FADS-ZU, 4178 and RPXsuper) to be able to adjust the position of 4179 the IMMR register after a reset. 4180 4181- CONFIG_SYS_CCSRBAR_DEFAULT: 4182 Default (power-on reset) physical address of CCSR on Freescale 4183 PowerPC SOCs. 4184 4185- CONFIG_SYS_CCSRBAR: 4186 Virtual address of CCSR. On a 32-bit build, this is typically 4187 the same value as CONFIG_SYS_CCSRBAR_DEFAULT. 4188 4189 CONFIG_SYS_DEFAULT_IMMR must also be set to this value, 4190 for cross-platform code that uses that macro instead. 4191 4192- CONFIG_SYS_CCSRBAR_PHYS: 4193 Physical address of CCSR. CCSR can be relocated to a new 4194 physical address, if desired. In this case, this macro should 4195 be set to that address. Otherwise, it should be set to the 4196 same value as CONFIG_SYS_CCSRBAR_DEFAULT. For example, CCSR 4197 is typically relocated on 36-bit builds. It is recommended 4198 that this macro be defined via the _HIGH and _LOW macros: 4199 4200 #define CONFIG_SYS_CCSRBAR_PHYS ((CONFIG_SYS_CCSRBAR_PHYS_HIGH 4201 * 1ull) << 32 | CONFIG_SYS_CCSRBAR_PHYS_LOW) 4202 4203- CONFIG_SYS_CCSRBAR_PHYS_HIGH: 4204 Bits 33-36 of CONFIG_SYS_CCSRBAR_PHYS. This value is typically 4205 either 0 (32-bit build) or 0xF (36-bit build). This macro is 4206 used in assembly code, so it must not contain typecasts or 4207 integer size suffixes (e.g. "ULL"). 4208 4209- CONFIG_SYS_CCSRBAR_PHYS_LOW: 4210 Lower 32-bits of CONFIG_SYS_CCSRBAR_PHYS. This macro is 4211 used in assembly code, so it must not contain typecasts or 4212 integer size suffixes (e.g. "ULL"). 4213 4214- CONFIG_SYS_CCSR_DO_NOT_RELOCATE: 4215 If this macro is defined, then CONFIG_SYS_CCSRBAR_PHYS will be 4216 forced to a value that ensures that CCSR is not relocated. 4217 4218- Floppy Disk Support: 4219 CONFIG_SYS_FDC_DRIVE_NUMBER 4220 4221 the default drive number (default value 0) 4222 4223 CONFIG_SYS_ISA_IO_STRIDE 4224 4225 defines the spacing between FDC chipset registers 4226 (default value 1) 4227 4228 CONFIG_SYS_ISA_IO_OFFSET 4229 4230 defines the offset of register from address. It 4231 depends on which part of the data bus is connected to 4232 the FDC chipset. (default value 0) 4233 4234 If CONFIG_SYS_ISA_IO_STRIDE CONFIG_SYS_ISA_IO_OFFSET and 4235 CONFIG_SYS_FDC_DRIVE_NUMBER are undefined, they take their 4236 default value. 4237 4238 if CONFIG_SYS_FDC_HW_INIT is defined, then the function 4239 fdc_hw_init() is called at the beginning of the FDC 4240 setup. fdc_hw_init() must be provided by the board 4241 source code. It is used to make hardware-dependent 4242 initializations. 4243 4244- CONFIG_IDE_AHB: 4245 Most IDE controllers were designed to be connected with PCI 4246 interface. Only few of them were designed for AHB interface. 4247 When software is doing ATA command and data transfer to 4248 IDE devices through IDE-AHB controller, some additional 4249 registers accessing to these kind of IDE-AHB controller 4250 is required. 4251 4252- CONFIG_SYS_IMMR: Physical address of the Internal Memory. 4253 DO NOT CHANGE unless you know exactly what you're 4254 doing! (11-4) [MPC8xx/82xx systems only] 4255 4256- CONFIG_SYS_INIT_RAM_ADDR: 4257 4258 Start address of memory area that can be used for 4259 initial data and stack; please note that this must be 4260 writable memory that is working WITHOUT special 4261 initialization, i. e. you CANNOT use normal RAM which 4262 will become available only after programming the 4263 memory controller and running certain initialization 4264 sequences. 4265 4266 U-Boot uses the following memory types: 4267 - MPC8xx and MPC8260: IMMR (internal memory of the CPU) 4268 - MPC824X: data cache 4269 - PPC4xx: data cache 4270 4271- CONFIG_SYS_GBL_DATA_OFFSET: 4272 4273 Offset of the initial data structure in the memory 4274 area defined by CONFIG_SYS_INIT_RAM_ADDR. Usually 4275 CONFIG_SYS_GBL_DATA_OFFSET is chosen such that the initial 4276 data is located at the end of the available space 4277 (sometimes written as (CONFIG_SYS_INIT_RAM_SIZE - 4278 GENERATED_GBL_DATA_SIZE), and the initial stack is just 4279 below that area (growing from (CONFIG_SYS_INIT_RAM_ADDR + 4280 CONFIG_SYS_GBL_DATA_OFFSET) downward. 4281 4282 Note: 4283 On the MPC824X (or other systems that use the data 4284 cache for initial memory) the address chosen for 4285 CONFIG_SYS_INIT_RAM_ADDR is basically arbitrary - it must 4286 point to an otherwise UNUSED address space between 4287 the top of RAM and the start of the PCI space. 4288 4289- CONFIG_SYS_SIUMCR: SIU Module Configuration (11-6) 4290 4291- CONFIG_SYS_SYPCR: System Protection Control (11-9) 4292 4293- CONFIG_SYS_TBSCR: Time Base Status and Control (11-26) 4294 4295- CONFIG_SYS_PISCR: Periodic Interrupt Status and Control (11-31) 4296 4297- CONFIG_SYS_PLPRCR: PLL, Low-Power, and Reset Control Register (15-30) 4298 4299- CONFIG_SYS_SCCR: System Clock and reset Control Register (15-27) 4300 4301- CONFIG_SYS_OR_TIMING_SDRAM: 4302 SDRAM timing 4303 4304- CONFIG_SYS_MAMR_PTA: 4305 periodic timer for refresh 4306 4307- CONFIG_SYS_DER: Debug Event Register (37-47) 4308 4309- FLASH_BASE0_PRELIM, FLASH_BASE1_PRELIM, CONFIG_SYS_REMAP_OR_AM, 4310 CONFIG_SYS_PRELIM_OR_AM, CONFIG_SYS_OR_TIMING_FLASH, CONFIG_SYS_OR0_REMAP, 4311 CONFIG_SYS_OR0_PRELIM, CONFIG_SYS_BR0_PRELIM, CONFIG_SYS_OR1_REMAP, CONFIG_SYS_OR1_PRELIM, 4312 CONFIG_SYS_BR1_PRELIM: 4313 Memory Controller Definitions: BR0/1 and OR0/1 (FLASH) 4314 4315- SDRAM_BASE2_PRELIM, SDRAM_BASE3_PRELIM, SDRAM_MAX_SIZE, 4316 CONFIG_SYS_OR_TIMING_SDRAM, CONFIG_SYS_OR2_PRELIM, CONFIG_SYS_BR2_PRELIM, 4317 CONFIG_SYS_OR3_PRELIM, CONFIG_SYS_BR3_PRELIM: 4318 Memory Controller Definitions: BR2/3 and OR2/3 (SDRAM) 4319 4320- CONFIG_SYS_MAMR_PTA, CONFIG_SYS_MPTPR_2BK_4K, CONFIG_SYS_MPTPR_1BK_4K, CONFIG_SYS_MPTPR_2BK_8K, 4321 CONFIG_SYS_MPTPR_1BK_8K, CONFIG_SYS_MAMR_8COL, CONFIG_SYS_MAMR_9COL: 4322 Machine Mode Register and Memory Periodic Timer 4323 Prescaler definitions (SDRAM timing) 4324 4325- CONFIG_SYS_I2C_UCODE_PATCH, CONFIG_SYS_I2C_DPMEM_OFFSET [0x1FC0]: 4326 enable I2C microcode relocation patch (MPC8xx); 4327 define relocation offset in DPRAM [DSP2] 4328 4329- CONFIG_SYS_SMC_UCODE_PATCH, CONFIG_SYS_SMC_DPMEM_OFFSET [0x1FC0]: 4330 enable SMC microcode relocation patch (MPC8xx); 4331 define relocation offset in DPRAM [SMC1] 4332 4333- CONFIG_SYS_SPI_UCODE_PATCH, CONFIG_SYS_SPI_DPMEM_OFFSET [0x1FC0]: 4334 enable SPI microcode relocation patch (MPC8xx); 4335 define relocation offset in DPRAM [SCC4] 4336 4337- CONFIG_SYS_CPM_POST_WORD_ADDR: (MPC8xx, MPC8260 only) 4338 Offset of the bootmode word in DPRAM used by post 4339 (Power On Self Tests). This definition overrides 4340 #define'd default value in commproc.h resp. 4341 cpm_8260.h. 4342 4343- CONFIG_SYS_PCI_SLV_MEM_LOCAL, CONFIG_SYS_PCI_SLV_MEM_BUS, CONFIG_SYS_PICMR0_MASK_ATTRIB, 4344 CONFIG_SYS_PCI_MSTR0_LOCAL, CONFIG_SYS_PCIMSK0_MASK, CONFIG_SYS_PCI_MSTR1_LOCAL, 4345 CONFIG_SYS_PCIMSK1_MASK, CONFIG_SYS_PCI_MSTR_MEM_LOCAL, CONFIG_SYS_PCI_MSTR_MEM_BUS, 4346 CONFIG_SYS_CPU_PCI_MEM_START, CONFIG_SYS_PCI_MSTR_MEM_SIZE, CONFIG_SYS_POCMR0_MASK_ATTRIB, 4347 CONFIG_SYS_PCI_MSTR_MEMIO_LOCAL, CONFIG_SYS_PCI_MSTR_MEMIO_BUS, CPU_PCI_MEMIO_START, 4348 CONFIG_SYS_PCI_MSTR_MEMIO_SIZE, CONFIG_SYS_POCMR1_MASK_ATTRIB, CONFIG_SYS_PCI_MSTR_IO_LOCAL, 4349 CONFIG_SYS_PCI_MSTR_IO_BUS, CONFIG_SYS_CPU_PCI_IO_START, CONFIG_SYS_PCI_MSTR_IO_SIZE, 4350 CONFIG_SYS_POCMR2_MASK_ATTRIB: (MPC826x only) 4351 Overrides the default PCI memory map in arch/powerpc/cpu/mpc8260/pci.c if set. 4352 4353- CONFIG_PCI_DISABLE_PCIE: 4354 Disable PCI-Express on systems where it is supported but not 4355 required. 4356 4357- CONFIG_PCI_ENUM_ONLY 4358 Only scan through and get the devices on the buses. 4359 Don't do any setup work, presumably because someone or 4360 something has already done it, and we don't need to do it 4361 a second time. Useful for platforms that are pre-booted 4362 by coreboot or similar. 4363 4364- CONFIG_PCI_INDIRECT_BRIDGE: 4365 Enable support for indirect PCI bridges. 4366 4367- CONFIG_SYS_SRIO: 4368 Chip has SRIO or not 4369 4370- CONFIG_SRIO1: 4371 Board has SRIO 1 port available 4372 4373- CONFIG_SRIO2: 4374 Board has SRIO 2 port available 4375 4376- CONFIG_SRIO_PCIE_BOOT_MASTER 4377 Board can support master function for Boot from SRIO and PCIE 4378 4379- CONFIG_SYS_SRIOn_MEM_VIRT: 4380 Virtual Address of SRIO port 'n' memory region 4381 4382- CONFIG_SYS_SRIOn_MEM_PHYS: 4383 Physical Address of SRIO port 'n' memory region 4384 4385- CONFIG_SYS_SRIOn_MEM_SIZE: 4386 Size of SRIO port 'n' memory region 4387 4388- CONFIG_SYS_NAND_BUSWIDTH_16BIT 4389 Defined to tell the NAND controller that the NAND chip is using 4390 a 16 bit bus. 4391 Not all NAND drivers use this symbol. 4392 Example of drivers that use it: 4393 - drivers/mtd/nand/ndfc.c 4394 - drivers/mtd/nand/mxc_nand.c 4395 4396- CONFIG_SYS_NDFC_EBC0_CFG 4397 Sets the EBC0_CFG register for the NDFC. If not defined 4398 a default value will be used. 4399 4400- CONFIG_SPD_EEPROM 4401 Get DDR timing information from an I2C EEPROM. Common 4402 with pluggable memory modules such as SODIMMs 4403 4404 SPD_EEPROM_ADDRESS 4405 I2C address of the SPD EEPROM 4406 4407- CONFIG_SYS_SPD_BUS_NUM 4408 If SPD EEPROM is on an I2C bus other than the first 4409 one, specify here. Note that the value must resolve 4410 to something your driver can deal with. 4411 4412- CONFIG_SYS_DDR_RAW_TIMING 4413 Get DDR timing information from other than SPD. Common with 4414 soldered DDR chips onboard without SPD. DDR raw timing 4415 parameters are extracted from datasheet and hard-coded into 4416 header files or board specific files. 4417 4418- CONFIG_FSL_DDR_INTERACTIVE 4419 Enable interactive DDR debugging. See doc/README.fsl-ddr. 4420 4421- CONFIG_FSL_DDR_SYNC_REFRESH 4422 Enable sync of refresh for multiple controllers. 4423 4424- CONFIG_FSL_DDR_BIST 4425 Enable built-in memory test for Freescale DDR controllers. 4426 4427- CONFIG_SYS_83XX_DDR_USES_CS0 4428 Only for 83xx systems. If specified, then DDR should 4429 be configured using CS0 and CS1 instead of CS2 and CS3. 4430 4431- CONFIG_ETHER_ON_FEC[12] 4432 Define to enable FEC[12] on a 8xx series processor. 4433 4434- CONFIG_FEC[12]_PHY 4435 Define to the hardcoded PHY address which corresponds 4436 to the given FEC; i. e. 4437 #define CONFIG_FEC1_PHY 4 4438 means that the PHY with address 4 is connected to FEC1 4439 4440 When set to -1, means to probe for first available. 4441 4442- CONFIG_FEC[12]_PHY_NORXERR 4443 The PHY does not have a RXERR line (RMII only). 4444 (so program the FEC to ignore it). 4445 4446- CONFIG_RMII 4447 Enable RMII mode for all FECs. 4448 Note that this is a global option, we can't 4449 have one FEC in standard MII mode and another in RMII mode. 4450 4451- CONFIG_CRC32_VERIFY 4452 Add a verify option to the crc32 command. 4453 The syntax is: 4454 4455 => crc32 -v <address> <count> <crc32> 4456 4457 Where address/count indicate a memory area 4458 and crc32 is the correct crc32 which the 4459 area should have. 4460 4461- CONFIG_LOOPW 4462 Add the "loopw" memory command. This only takes effect if 4463 the memory commands are activated globally (CONFIG_CMD_MEM). 4464 4465- CONFIG_MX_CYCLIC 4466 Add the "mdc" and "mwc" memory commands. These are cyclic 4467 "md/mw" commands. 4468 Examples: 4469 4470 => mdc.b 10 4 500 4471 This command will print 4 bytes (10,11,12,13) each 500 ms. 4472 4473 => mwc.l 100 12345678 10 4474 This command will write 12345678 to address 100 all 10 ms. 4475 4476 This only takes effect if the memory commands are activated 4477 globally (CONFIG_CMD_MEM). 4478 4479- CONFIG_SKIP_LOWLEVEL_INIT 4480 [ARM, NDS32, MIPS only] If this variable is defined, then certain 4481 low level initializations (like setting up the memory 4482 controller) are omitted and/or U-Boot does not 4483 relocate itself into RAM. 4484 4485 Normally this variable MUST NOT be defined. The only 4486 exception is when U-Boot is loaded (to RAM) by some 4487 other boot loader or by a debugger which performs 4488 these initializations itself. 4489 4490- CONFIG_SKIP_LOWLEVEL_INIT_ONLY 4491 [ARM926EJ-S only] This allows just the call to lowlevel_init() 4492 to be skipped. The normal CP15 init (such as enabling the 4493 instruction cache) is still performed. 4494 4495- CONFIG_SPL_BUILD 4496 Modifies the behaviour of start.S when compiling a loader 4497 that is executed before the actual U-Boot. E.g. when 4498 compiling a NAND SPL. 4499 4500- CONFIG_TPL_BUILD 4501 Modifies the behaviour of start.S when compiling a loader 4502 that is executed after the SPL and before the actual U-Boot. 4503 It is loaded by the SPL. 4504 4505- CONFIG_SYS_MPC85XX_NO_RESETVEC 4506 Only for 85xx systems. If this variable is specified, the section 4507 .resetvec is not kept and the section .bootpg is placed in the 4508 previous 4k of the .text section. 4509 4510- CONFIG_ARCH_MAP_SYSMEM 4511 Generally U-Boot (and in particular the md command) uses 4512 effective address. It is therefore not necessary to regard 4513 U-Boot address as virtual addresses that need to be translated 4514 to physical addresses. However, sandbox requires this, since 4515 it maintains its own little RAM buffer which contains all 4516 addressable memory. This option causes some memory accesses 4517 to be mapped through map_sysmem() / unmap_sysmem(). 4518 4519- CONFIG_X86_RESET_VECTOR 4520 If defined, the x86 reset vector code is included. This is not 4521 needed when U-Boot is running from Coreboot. 4522 4523- CONFIG_SYS_MPUCLK 4524 Defines the MPU clock speed (in MHz). 4525 4526 NOTE : currently only supported on AM335x platforms. 4527 4528- CONFIG_SPL_AM33XX_ENABLE_RTC32K_OSC: 4529 Enables the RTC32K OSC on AM33xx based plattforms 4530 4531- CONFIG_SYS_NAND_NO_SUBPAGE_WRITE 4532 Option to disable subpage write in NAND driver 4533 driver that uses this: 4534 drivers/mtd/nand/davinci_nand.c 4535 4536Freescale QE/FMAN Firmware Support: 4537----------------------------------- 4538 4539The Freescale QUICCEngine (QE) and Frame Manager (FMAN) both support the 4540loading of "firmware", which is encoded in the QE firmware binary format. 4541This firmware often needs to be loaded during U-Boot booting, so macros 4542are used to identify the storage device (NOR flash, SPI, etc) and the address 4543within that device. 4544 4545- CONFIG_SYS_FMAN_FW_ADDR 4546 The address in the storage device where the FMAN microcode is located. The 4547 meaning of this address depends on which CONFIG_SYS_QE_FW_IN_xxx macro 4548 is also specified. 4549 4550- CONFIG_SYS_QE_FW_ADDR 4551 The address in the storage device where the QE microcode is located. The 4552 meaning of this address depends on which CONFIG_SYS_QE_FW_IN_xxx macro 4553 is also specified. 4554 4555- CONFIG_SYS_QE_FMAN_FW_LENGTH 4556 The maximum possible size of the firmware. The firmware binary format 4557 has a field that specifies the actual size of the firmware, but it 4558 might not be possible to read any part of the firmware unless some 4559 local storage is allocated to hold the entire firmware first. 4560 4561- CONFIG_SYS_QE_FMAN_FW_IN_NOR 4562 Specifies that QE/FMAN firmware is located in NOR flash, mapped as 4563 normal addressable memory via the LBC. CONFIG_SYS_FMAN_FW_ADDR is the 4564 virtual address in NOR flash. 4565 4566- CONFIG_SYS_QE_FMAN_FW_IN_NAND 4567 Specifies that QE/FMAN firmware is located in NAND flash. 4568 CONFIG_SYS_FMAN_FW_ADDR is the offset within NAND flash. 4569 4570- CONFIG_SYS_QE_FMAN_FW_IN_MMC 4571 Specifies that QE/FMAN firmware is located on the primary SD/MMC 4572 device. CONFIG_SYS_FMAN_FW_ADDR is the byte offset on that device. 4573 4574- CONFIG_SYS_QE_FMAN_FW_IN_REMOTE 4575 Specifies that QE/FMAN firmware is located in the remote (master) 4576 memory space. CONFIG_SYS_FMAN_FW_ADDR is a virtual address which 4577 can be mapped from slave TLB->slave LAW->slave SRIO or PCIE outbound 4578 window->master inbound window->master LAW->the ucode address in 4579 master's memory space. 4580 4581Freescale Layerscape Management Complex Firmware Support: 4582--------------------------------------------------------- 4583The Freescale Layerscape Management Complex (MC) supports the loading of 4584"firmware". 4585This firmware often needs to be loaded during U-Boot booting, so macros 4586are used to identify the storage device (NOR flash, SPI, etc) and the address 4587within that device. 4588 4589- CONFIG_FSL_MC_ENET 4590 Enable the MC driver for Layerscape SoCs. 4591 4592Freescale Layerscape Debug Server Support: 4593------------------------------------------- 4594The Freescale Layerscape Debug Server Support supports the loading of 4595"Debug Server firmware" and triggering SP boot-rom. 4596This firmware often needs to be loaded during U-Boot booting. 4597 4598- CONFIG_SYS_MC_RSV_MEM_ALIGN 4599 Define alignment of reserved memory MC requires 4600 4601Reproducible builds 4602------------------- 4603 4604In order to achieve reproducible builds, timestamps used in the U-Boot build 4605process have to be set to a fixed value. 4606 4607This is done using the SOURCE_DATE_EPOCH environment variable. 4608SOURCE_DATE_EPOCH is to be set on the build host's shell, not as a configuration 4609option for U-Boot or an environment variable in U-Boot. 4610 4611SOURCE_DATE_EPOCH should be set to a number of seconds since the epoch, in UTC. 4612 4613Building the Software: 4614====================== 4615 4616Building U-Boot has been tested in several native build environments 4617and in many different cross environments. Of course we cannot support 4618all possibly existing versions of cross development tools in all 4619(potentially obsolete) versions. In case of tool chain problems we 4620recommend to use the ELDK (see http://www.denx.de/wiki/DULG/ELDK) 4621which is extensively used to build and test U-Boot. 4622 4623If you are not using a native environment, it is assumed that you 4624have GNU cross compiling tools available in your path. In this case, 4625you must set the environment variable CROSS_COMPILE in your shell. 4626Note that no changes to the Makefile or any other source files are 4627necessary. For example using the ELDK on a 4xx CPU, please enter: 4628 4629 $ CROSS_COMPILE=ppc_4xx- 4630 $ export CROSS_COMPILE 4631 4632Note: If you wish to generate Windows versions of the utilities in 4633 the tools directory you can use the MinGW toolchain 4634 (http://www.mingw.org). Set your HOST tools to the MinGW 4635 toolchain and execute 'make tools'. For example: 4636 4637 $ make HOSTCC=i586-mingw32msvc-gcc HOSTSTRIP=i586-mingw32msvc-strip tools 4638 4639 Binaries such as tools/mkimage.exe will be created which can 4640 be executed on computers running Windows. 4641 4642U-Boot is intended to be simple to build. After installing the 4643sources you must configure U-Boot for one specific board type. This 4644is done by typing: 4645 4646 make NAME_defconfig 4647 4648where "NAME_defconfig" is the name of one of the existing configu- 4649rations; see boards.cfg for supported names. 4650 4651Note: for some board special configuration names may exist; check if 4652 additional information is available from the board vendor; for 4653 instance, the TQM823L systems are available without (standard) 4654 or with LCD support. You can select such additional "features" 4655 when choosing the configuration, i. e. 4656 4657 make TQM823L_defconfig 4658 - will configure for a plain TQM823L, i. e. no LCD support 4659 4660 make TQM823L_LCD_defconfig 4661 - will configure for a TQM823L with U-Boot console on LCD 4662 4663 etc. 4664 4665 4666Finally, type "make all", and you should get some working U-Boot 4667images ready for download to / installation on your system: 4668 4669- "u-boot.bin" is a raw binary image 4670- "u-boot" is an image in ELF binary format 4671- "u-boot.srec" is in Motorola S-Record format 4672 4673By default the build is performed locally and the objects are saved 4674in the source directory. One of the two methods can be used to change 4675this behavior and build U-Boot to some external directory: 4676 46771. Add O= to the make command line invocations: 4678 4679 make O=/tmp/build distclean 4680 make O=/tmp/build NAME_defconfig 4681 make O=/tmp/build all 4682 46832. Set environment variable KBUILD_OUTPUT to point to the desired location: 4684 4685 export KBUILD_OUTPUT=/tmp/build 4686 make distclean 4687 make NAME_defconfig 4688 make all 4689 4690Note that the command line "O=" setting overrides the KBUILD_OUTPUT environment 4691variable. 4692 4693 4694Please be aware that the Makefiles assume you are using GNU make, so 4695for instance on NetBSD you might need to use "gmake" instead of 4696native "make". 4697 4698 4699If the system board that you have is not listed, then you will need 4700to port U-Boot to your hardware platform. To do this, follow these 4701steps: 4702 47031. Create a new directory to hold your board specific code. Add any 4704 files you need. In your board directory, you will need at least 4705 the "Makefile" and a "<board>.c". 47062. Create a new configuration file "include/configs/<board>.h" for 4707 your board. 47083. If you're porting U-Boot to a new CPU, then also create a new 4709 directory to hold your CPU specific code. Add any files you need. 47104. Run "make <board>_defconfig" with your new name. 47115. Type "make", and you should get a working "u-boot.srec" file 4712 to be installed on your target system. 47136. Debug and solve any problems that might arise. 4714 [Of course, this last step is much harder than it sounds.] 4715 4716 4717Testing of U-Boot Modifications, Ports to New Hardware, etc.: 4718============================================================== 4719 4720If you have modified U-Boot sources (for instance added a new board 4721or support for new devices, a new CPU, etc.) you are expected to 4722provide feedback to the other developers. The feedback normally takes 4723the form of a "patch", i. e. a context diff against a certain (latest 4724official or latest in the git repository) version of U-Boot sources. 4725 4726But before you submit such a patch, please verify that your modifi- 4727cation did not break existing code. At least make sure that *ALL* of 4728the supported boards compile WITHOUT ANY compiler warnings. To do so, 4729just run the buildman script (tools/buildman/buildman), which will 4730configure and build U-Boot for ALL supported system. Be warned, this 4731will take a while. Please see the buildman README, or run 'buildman -H' 4732for documentation. 4733 4734 4735See also "U-Boot Porting Guide" below. 4736 4737 4738Monitor Commands - Overview: 4739============================ 4740 4741go - start application at address 'addr' 4742run - run commands in an environment variable 4743bootm - boot application image from memory 4744bootp - boot image via network using BootP/TFTP protocol 4745bootz - boot zImage from memory 4746tftpboot- boot image via network using TFTP protocol 4747 and env variables "ipaddr" and "serverip" 4748 (and eventually "gatewayip") 4749tftpput - upload a file via network using TFTP protocol 4750rarpboot- boot image via network using RARP/TFTP protocol 4751diskboot- boot from IDE devicebootd - boot default, i.e., run 'bootcmd' 4752loads - load S-Record file over serial line 4753loadb - load binary file over serial line (kermit mode) 4754md - memory display 4755mm - memory modify (auto-incrementing) 4756nm - memory modify (constant address) 4757mw - memory write (fill) 4758cp - memory copy 4759cmp - memory compare 4760crc32 - checksum calculation 4761i2c - I2C sub-system 4762sspi - SPI utility commands 4763base - print or set address offset 4764printenv- print environment variables 4765setenv - set environment variables 4766saveenv - save environment variables to persistent storage 4767protect - enable or disable FLASH write protection 4768erase - erase FLASH memory 4769flinfo - print FLASH memory information 4770nand - NAND memory operations (see doc/README.nand) 4771bdinfo - print Board Info structure 4772iminfo - print header information for application image 4773coninfo - print console devices and informations 4774ide - IDE sub-system 4775loop - infinite loop on address range 4776loopw - infinite write loop on address range 4777mtest - simple RAM test 4778icache - enable or disable instruction cache 4779dcache - enable or disable data cache 4780reset - Perform RESET of the CPU 4781echo - echo args to console 4782version - print monitor version 4783help - print online help 4784? - alias for 'help' 4785 4786 4787Monitor Commands - Detailed Description: 4788======================================== 4789 4790TODO. 4791 4792For now: just type "help <command>". 4793 4794 4795Environment Variables: 4796====================== 4797 4798U-Boot supports user configuration using Environment Variables which 4799can be made persistent by saving to Flash memory. 4800 4801Environment Variables are set using "setenv", printed using 4802"printenv", and saved to Flash using "saveenv". Using "setenv" 4803without a value can be used to delete a variable from the 4804environment. As long as you don't save the environment you are 4805working with an in-memory copy. In case the Flash area containing the 4806environment is erased by accident, a default environment is provided. 4807 4808Some configuration options can be set using Environment Variables. 4809 4810List of environment variables (most likely not complete): 4811 4812 baudrate - see CONFIG_BAUDRATE 4813 4814 bootdelay - see CONFIG_BOOTDELAY 4815 4816 bootcmd - see CONFIG_BOOTCOMMAND 4817 4818 bootargs - Boot arguments when booting an RTOS image 4819 4820 bootfile - Name of the image to load with TFTP 4821 4822 bootm_low - Memory range available for image processing in the bootm 4823 command can be restricted. This variable is given as 4824 a hexadecimal number and defines lowest address allowed 4825 for use by the bootm command. See also "bootm_size" 4826 environment variable. Address defined by "bootm_low" is 4827 also the base of the initial memory mapping for the Linux 4828 kernel -- see the description of CONFIG_SYS_BOOTMAPSZ and 4829 bootm_mapsize. 4830 4831 bootm_mapsize - Size of the initial memory mapping for the Linux kernel. 4832 This variable is given as a hexadecimal number and it 4833 defines the size of the memory region starting at base 4834 address bootm_low that is accessible by the Linux kernel 4835 during early boot. If unset, CONFIG_SYS_BOOTMAPSZ is used 4836 as the default value if it is defined, and bootm_size is 4837 used otherwise. 4838 4839 bootm_size - Memory range available for image processing in the bootm 4840 command can be restricted. This variable is given as 4841 a hexadecimal number and defines the size of the region 4842 allowed for use by the bootm command. See also "bootm_low" 4843 environment variable. 4844 4845 updatefile - Location of the software update file on a TFTP server, used 4846 by the automatic software update feature. Please refer to 4847 documentation in doc/README.update for more details. 4848 4849 autoload - if set to "no" (any string beginning with 'n'), 4850 "bootp" will just load perform a lookup of the 4851 configuration from the BOOTP server, but not try to 4852 load any image using TFTP 4853 4854 autostart - if set to "yes", an image loaded using the "bootp", 4855 "rarpboot", "tftpboot" or "diskboot" commands will 4856 be automatically started (by internally calling 4857 "bootm") 4858 4859 If set to "no", a standalone image passed to the 4860 "bootm" command will be copied to the load address 4861 (and eventually uncompressed), but NOT be started. 4862 This can be used to load and uncompress arbitrary 4863 data. 4864 4865 fdt_high - if set this restricts the maximum address that the 4866 flattened device tree will be copied into upon boot. 4867 For example, if you have a system with 1 GB memory 4868 at physical address 0x10000000, while Linux kernel 4869 only recognizes the first 704 MB as low memory, you 4870 may need to set fdt_high as 0x3C000000 to have the 4871 device tree blob be copied to the maximum address 4872 of the 704 MB low memory, so that Linux kernel can 4873 access it during the boot procedure. 4874 4875 If this is set to the special value 0xFFFFFFFF then 4876 the fdt will not be copied at all on boot. For this 4877 to work it must reside in writable memory, have 4878 sufficient padding on the end of it for u-boot to 4879 add the information it needs into it, and the memory 4880 must be accessible by the kernel. 4881 4882 fdtcontroladdr- if set this is the address of the control flattened 4883 device tree used by U-Boot when CONFIG_OF_CONTROL is 4884 defined. 4885 4886 i2cfast - (PPC405GP|PPC405EP only) 4887 if set to 'y' configures Linux I2C driver for fast 4888 mode (400kHZ). This environment variable is used in 4889 initialization code. So, for changes to be effective 4890 it must be saved and board must be reset. 4891 4892 initrd_high - restrict positioning of initrd images: 4893 If this variable is not set, initrd images will be 4894 copied to the highest possible address in RAM; this 4895 is usually what you want since it allows for 4896 maximum initrd size. If for some reason you want to 4897 make sure that the initrd image is loaded below the 4898 CONFIG_SYS_BOOTMAPSZ limit, you can set this environment 4899 variable to a value of "no" or "off" or "0". 4900 Alternatively, you can set it to a maximum upper 4901 address to use (U-Boot will still check that it 4902 does not overwrite the U-Boot stack and data). 4903 4904 For instance, when you have a system with 16 MB 4905 RAM, and want to reserve 4 MB from use by Linux, 4906 you can do this by adding "mem=12M" to the value of 4907 the "bootargs" variable. However, now you must make 4908 sure that the initrd image is placed in the first 4909 12 MB as well - this can be done with 4910 4911 setenv initrd_high 00c00000 4912 4913 If you set initrd_high to 0xFFFFFFFF, this is an 4914 indication to U-Boot that all addresses are legal 4915 for the Linux kernel, including addresses in flash 4916 memory. In this case U-Boot will NOT COPY the 4917 ramdisk at all. This may be useful to reduce the 4918 boot time on your system, but requires that this 4919 feature is supported by your Linux kernel. 4920 4921 ipaddr - IP address; needed for tftpboot command 4922 4923 loadaddr - Default load address for commands like "bootp", 4924 "rarpboot", "tftpboot", "loadb" or "diskboot" 4925 4926 loads_echo - see CONFIG_LOADS_ECHO 4927 4928 serverip - TFTP server IP address; needed for tftpboot command 4929 4930 bootretry - see CONFIG_BOOT_RETRY_TIME 4931 4932 bootdelaykey - see CONFIG_AUTOBOOT_DELAY_STR 4933 4934 bootstopkey - see CONFIG_AUTOBOOT_STOP_STR 4935 4936 ethprime - controls which interface is used first. 4937 4938 ethact - controls which interface is currently active. 4939 For example you can do the following 4940 4941 => setenv ethact FEC 4942 => ping 192.168.0.1 # traffic sent on FEC 4943 => setenv ethact SCC 4944 => ping 10.0.0.1 # traffic sent on SCC 4945 4946 ethrotate - When set to "no" U-Boot does not go through all 4947 available network interfaces. 4948 It just stays at the currently selected interface. 4949 4950 netretry - When set to "no" each network operation will 4951 either succeed or fail without retrying. 4952 When set to "once" the network operation will 4953 fail when all the available network interfaces 4954 are tried once without success. 4955 Useful on scripts which control the retry operation 4956 themselves. 4957 4958 npe_ucode - set load address for the NPE microcode 4959 4960 silent_linux - If set then Linux will be told to boot silently, by 4961 changing the console to be empty. If "yes" it will be 4962 made silent. If "no" it will not be made silent. If 4963 unset, then it will be made silent if the U-Boot console 4964 is silent. 4965 4966 tftpsrcp - If this is set, the value is used for TFTP's 4967 UDP source port. 4968 4969 tftpdstp - If this is set, the value is used for TFTP's UDP 4970 destination port instead of the Well Know Port 69. 4971 4972 tftpblocksize - Block size to use for TFTP transfers; if not set, 4973 we use the TFTP server's default block size 4974 4975 tftptimeout - Retransmission timeout for TFTP packets (in milli- 4976 seconds, minimum value is 1000 = 1 second). Defines 4977 when a packet is considered to be lost so it has to 4978 be retransmitted. The default is 5000 = 5 seconds. 4979 Lowering this value may make downloads succeed 4980 faster in networks with high packet loss rates or 4981 with unreliable TFTP servers. 4982 4983 tftptimeoutcountmax - maximum count of TFTP timeouts (no 4984 unit, minimum value = 0). Defines how many timeouts 4985 can happen during a single file transfer before that 4986 transfer is aborted. The default is 10, and 0 means 4987 'no timeouts allowed'. Increasing this value may help 4988 downloads succeed with high packet loss rates, or with 4989 unreliable TFTP servers or client hardware. 4990 4991 vlan - When set to a value < 4095 the traffic over 4992 Ethernet is encapsulated/received over 802.1q 4993 VLAN tagged frames. 4994 4995 bootpretryperiod - Period during which BOOTP/DHCP sends retries. 4996 Unsigned value, in milliseconds. If not set, the period will 4997 be either the default (28000), or a value based on 4998 CONFIG_NET_RETRY_COUNT, if defined. This value has 4999 precedence over the valu based on CONFIG_NET_RETRY_COUNT. 5000 5001The following image location variables contain the location of images 5002used in booting. The "Image" column gives the role of the image and is 5003not an environment variable name. The other columns are environment 5004variable names. "File Name" gives the name of the file on a TFTP 5005server, "RAM Address" gives the location in RAM the image will be 5006loaded to, and "Flash Location" gives the image's address in NOR 5007flash or offset in NAND flash. 5008 5009*Note* - these variables don't have to be defined for all boards, some 5010boards currently use other variables for these purposes, and some 5011boards use these variables for other purposes. 5012 5013Image File Name RAM Address Flash Location 5014----- --------- ----------- -------------- 5015u-boot u-boot u-boot_addr_r u-boot_addr 5016Linux kernel bootfile kernel_addr_r kernel_addr 5017device tree blob fdtfile fdt_addr_r fdt_addr 5018ramdisk ramdiskfile ramdisk_addr_r ramdisk_addr 5019 5020The following environment variables may be used and automatically 5021updated by the network boot commands ("bootp" and "rarpboot"), 5022depending the information provided by your boot server: 5023 5024 bootfile - see above 5025 dnsip - IP address of your Domain Name Server 5026 dnsip2 - IP address of your secondary Domain Name Server 5027 gatewayip - IP address of the Gateway (Router) to use 5028 hostname - Target hostname 5029 ipaddr - see above 5030 netmask - Subnet Mask 5031 rootpath - Pathname of the root filesystem on the NFS server 5032 serverip - see above 5033 5034 5035There are two special Environment Variables: 5036 5037 serial# - contains hardware identification information such 5038 as type string and/or serial number 5039 ethaddr - Ethernet address 5040 5041These variables can be set only once (usually during manufacturing of 5042the board). U-Boot refuses to delete or overwrite these variables 5043once they have been set once. 5044 5045 5046Further special Environment Variables: 5047 5048 ver - Contains the U-Boot version string as printed 5049 with the "version" command. This variable is 5050 readonly (see CONFIG_VERSION_VARIABLE). 5051 5052 5053Please note that changes to some configuration parameters may take 5054only effect after the next boot (yes, that's just like Windoze :-). 5055 5056 5057Callback functions for environment variables: 5058--------------------------------------------- 5059 5060For some environment variables, the behavior of u-boot needs to change 5061when their values are changed. This functionality allows functions to 5062be associated with arbitrary variables. On creation, overwrite, or 5063deletion, the callback will provide the opportunity for some side 5064effect to happen or for the change to be rejected. 5065 5066The callbacks are named and associated with a function using the 5067U_BOOT_ENV_CALLBACK macro in your board or driver code. 5068 5069These callbacks are associated with variables in one of two ways. The 5070static list can be added to by defining CONFIG_ENV_CALLBACK_LIST_STATIC 5071in the board configuration to a string that defines a list of 5072associations. The list must be in the following format: 5073 5074 entry = variable_name[:callback_name] 5075 list = entry[,list] 5076 5077If the callback name is not specified, then the callback is deleted. 5078Spaces are also allowed anywhere in the list. 5079 5080Callbacks can also be associated by defining the ".callbacks" variable 5081with the same list format above. Any association in ".callbacks" will 5082override any association in the static list. You can define 5083CONFIG_ENV_CALLBACK_LIST_DEFAULT to a list (string) to define the 5084".callbacks" environment variable in the default or embedded environment. 5085 5086If CONFIG_REGEX is defined, the variable_name above is evaluated as a 5087regular expression. This allows multiple variables to be connected to 5088the same callback without explicitly listing them all out. 5089 5090 5091Command Line Parsing: 5092===================== 5093 5094There are two different command line parsers available with U-Boot: 5095the old "simple" one, and the much more powerful "hush" shell: 5096 5097Old, simple command line parser: 5098-------------------------------- 5099 5100- supports environment variables (through setenv / saveenv commands) 5101- several commands on one line, separated by ';' 5102- variable substitution using "... ${name} ..." syntax 5103- special characters ('$', ';') can be escaped by prefixing with '\', 5104 for example: 5105 setenv bootcmd bootm \${address} 5106- You can also escape text by enclosing in single apostrophes, for example: 5107 setenv addip 'setenv bootargs $bootargs ip=$ipaddr:$serverip:$gatewayip:$netmask:$hostname::off' 5108 5109Hush shell: 5110----------- 5111 5112- similar to Bourne shell, with control structures like 5113 if...then...else...fi, for...do...done; while...do...done, 5114 until...do...done, ... 5115- supports environment ("global") variables (through setenv / saveenv 5116 commands) and local shell variables (through standard shell syntax 5117 "name=value"); only environment variables can be used with "run" 5118 command 5119 5120General rules: 5121-------------- 5122 5123(1) If a command line (or an environment variable executed by a "run" 5124 command) contains several commands separated by semicolon, and 5125 one of these commands fails, then the remaining commands will be 5126 executed anyway. 5127 5128(2) If you execute several variables with one call to run (i. e. 5129 calling run with a list of variables as arguments), any failing 5130 command will cause "run" to terminate, i. e. the remaining 5131 variables are not executed. 5132 5133Note for Redundant Ethernet Interfaces: 5134======================================= 5135 5136Some boards come with redundant Ethernet interfaces; U-Boot supports 5137such configurations and is capable of automatic selection of a 5138"working" interface when needed. MAC assignment works as follows: 5139 5140Network interfaces are numbered eth0, eth1, eth2, ... Corresponding 5141MAC addresses can be stored in the environment as "ethaddr" (=>eth0), 5142"eth1addr" (=>eth1), "eth2addr", ... 5143 5144If the network interface stores some valid MAC address (for instance 5145in SROM), this is used as default address if there is NO correspon- 5146ding setting in the environment; if the corresponding environment 5147variable is set, this overrides the settings in the card; that means: 5148 5149o If the SROM has a valid MAC address, and there is no address in the 5150 environment, the SROM's address is used. 5151 5152o If there is no valid address in the SROM, and a definition in the 5153 environment exists, then the value from the environment variable is 5154 used. 5155 5156o If both the SROM and the environment contain a MAC address, and 5157 both addresses are the same, this MAC address is used. 5158 5159o If both the SROM and the environment contain a MAC address, and the 5160 addresses differ, the value from the environment is used and a 5161 warning is printed. 5162 5163o If neither SROM nor the environment contain a MAC address, an error 5164 is raised. If CONFIG_NET_RANDOM_ETHADDR is defined, then in this case 5165 a random, locally-assigned MAC is used. 5166 5167If Ethernet drivers implement the 'write_hwaddr' function, valid MAC addresses 5168will be programmed into hardware as part of the initialization process. This 5169may be skipped by setting the appropriate 'ethmacskip' environment variable. 5170The naming convention is as follows: 5171"ethmacskip" (=>eth0), "eth1macskip" (=>eth1) etc. 5172 5173Image Formats: 5174============== 5175 5176U-Boot is capable of booting (and performing other auxiliary operations on) 5177images in two formats: 5178 5179New uImage format (FIT) 5180----------------------- 5181 5182Flexible and powerful format based on Flattened Image Tree -- FIT (similar 5183to Flattened Device Tree). It allows the use of images with multiple 5184components (several kernels, ramdisks, etc.), with contents protected by 5185SHA1, MD5 or CRC32. More details are found in the doc/uImage.FIT directory. 5186 5187 5188Old uImage format 5189----------------- 5190 5191Old image format is based on binary files which can be basically anything, 5192preceded by a special header; see the definitions in include/image.h for 5193details; basically, the header defines the following image properties: 5194 5195* Target Operating System (Provisions for OpenBSD, NetBSD, FreeBSD, 5196 4.4BSD, Linux, SVR4, Esix, Solaris, Irix, SCO, Dell, NCR, VxWorks, 5197 LynxOS, pSOS, QNX, RTEMS, INTEGRITY; 5198 Currently supported: Linux, NetBSD, VxWorks, QNX, RTEMS, LynxOS, 5199 INTEGRITY). 5200* Target CPU Architecture (Provisions for Alpha, ARM, AVR32, Intel x86, 5201 IA64, MIPS, NDS32, Nios II, PowerPC, IBM S390, SuperH, Sparc, Sparc 64 Bit; 5202 Currently supported: ARM, AVR32, Intel x86, MIPS, NDS32, Nios II, PowerPC). 5203* Compression Type (uncompressed, gzip, bzip2) 5204* Load Address 5205* Entry Point 5206* Image Name 5207* Image Timestamp 5208 5209The header is marked by a special Magic Number, and both the header 5210and the data portions of the image are secured against corruption by 5211CRC32 checksums. 5212 5213 5214Linux Support: 5215============== 5216 5217Although U-Boot should support any OS or standalone application 5218easily, the main focus has always been on Linux during the design of 5219U-Boot. 5220 5221U-Boot includes many features that so far have been part of some 5222special "boot loader" code within the Linux kernel. Also, any 5223"initrd" images to be used are no longer part of one big Linux image; 5224instead, kernel and "initrd" are separate images. This implementation 5225serves several purposes: 5226 5227- the same features can be used for other OS or standalone 5228 applications (for instance: using compressed images to reduce the 5229 Flash memory footprint) 5230 5231- it becomes much easier to port new Linux kernel versions because 5232 lots of low-level, hardware dependent stuff are done by U-Boot 5233 5234- the same Linux kernel image can now be used with different "initrd" 5235 images; of course this also means that different kernel images can 5236 be run with the same "initrd". This makes testing easier (you don't 5237 have to build a new "zImage.initrd" Linux image when you just 5238 change a file in your "initrd"). Also, a field-upgrade of the 5239 software is easier now. 5240 5241 5242Linux HOWTO: 5243============ 5244 5245Porting Linux to U-Boot based systems: 5246--------------------------------------- 5247 5248U-Boot cannot save you from doing all the necessary modifications to 5249configure the Linux device drivers for use with your target hardware 5250(no, we don't intend to provide a full virtual machine interface to 5251Linux :-). 5252 5253But now you can ignore ALL boot loader code (in arch/powerpc/mbxboot). 5254 5255Just make sure your machine specific header file (for instance 5256include/asm-ppc/tqm8xx.h) includes the same definition of the Board 5257Information structure as we define in include/asm-<arch>/u-boot.h, 5258and make sure that your definition of IMAP_ADDR uses the same value 5259as your U-Boot configuration in CONFIG_SYS_IMMR. 5260 5261Note that U-Boot now has a driver model, a unified model for drivers. 5262If you are adding a new driver, plumb it into driver model. If there 5263is no uclass available, you are encouraged to create one. See 5264doc/driver-model. 5265 5266 5267Configuring the Linux kernel: 5268----------------------------- 5269 5270No specific requirements for U-Boot. Make sure you have some root 5271device (initial ramdisk, NFS) for your target system. 5272 5273 5274Building a Linux Image: 5275----------------------- 5276 5277With U-Boot, "normal" build targets like "zImage" or "bzImage" are 5278not used. If you use recent kernel source, a new build target 5279"uImage" will exist which automatically builds an image usable by 5280U-Boot. Most older kernels also have support for a "pImage" target, 5281which was introduced for our predecessor project PPCBoot and uses a 5282100% compatible format. 5283 5284Example: 5285 5286 make TQM850L_defconfig 5287 make oldconfig 5288 make dep 5289 make uImage 5290 5291The "uImage" build target uses a special tool (in 'tools/mkimage') to 5292encapsulate a compressed Linux kernel image with header information, 5293CRC32 checksum etc. for use with U-Boot. This is what we are doing: 5294 5295* build a standard "vmlinux" kernel image (in ELF binary format): 5296 5297* convert the kernel into a raw binary image: 5298 5299 ${CROSS_COMPILE}-objcopy -O binary \ 5300 -R .note -R .comment \ 5301 -S vmlinux linux.bin 5302 5303* compress the binary image: 5304 5305 gzip -9 linux.bin 5306 5307* package compressed binary image for U-Boot: 5308 5309 mkimage -A ppc -O linux -T kernel -C gzip \ 5310 -a 0 -e 0 -n "Linux Kernel Image" \ 5311 -d linux.bin.gz uImage 5312 5313 5314The "mkimage" tool can also be used to create ramdisk images for use 5315with U-Boot, either separated from the Linux kernel image, or 5316combined into one file. "mkimage" encapsulates the images with a 64 5317byte header containing information about target architecture, 5318operating system, image type, compression method, entry points, time 5319stamp, CRC32 checksums, etc. 5320 5321"mkimage" can be called in two ways: to verify existing images and 5322print the header information, or to build new images. 5323 5324In the first form (with "-l" option) mkimage lists the information 5325contained in the header of an existing U-Boot image; this includes 5326checksum verification: 5327 5328 tools/mkimage -l image 5329 -l ==> list image header information 5330 5331The second form (with "-d" option) is used to build a U-Boot image 5332from a "data file" which is used as image payload: 5333 5334 tools/mkimage -A arch -O os -T type -C comp -a addr -e ep \ 5335 -n name -d data_file image 5336 -A ==> set architecture to 'arch' 5337 -O ==> set operating system to 'os' 5338 -T ==> set image type to 'type' 5339 -C ==> set compression type 'comp' 5340 -a ==> set load address to 'addr' (hex) 5341 -e ==> set entry point to 'ep' (hex) 5342 -n ==> set image name to 'name' 5343 -d ==> use image data from 'datafile' 5344 5345Right now, all Linux kernels for PowerPC systems use the same load 5346address (0x00000000), but the entry point address depends on the 5347kernel version: 5348 5349- 2.2.x kernels have the entry point at 0x0000000C, 5350- 2.3.x and later kernels have the entry point at 0x00000000. 5351 5352So a typical call to build a U-Boot image would read: 5353 5354 -> tools/mkimage -n '2.4.4 kernel for TQM850L' \ 5355 > -A ppc -O linux -T kernel -C gzip -a 0 -e 0 \ 5356 > -d /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/powerpc/coffboot/vmlinux.gz \ 5357 > examples/uImage.TQM850L 5358 Image Name: 2.4.4 kernel for TQM850L 5359 Created: Wed Jul 19 02:34:59 2000 5360 Image Type: PowerPC Linux Kernel Image (gzip compressed) 5361 Data Size: 335725 Bytes = 327.86 kB = 0.32 MB 5362 Load Address: 0x00000000 5363 Entry Point: 0x00000000 5364 5365To verify the contents of the image (or check for corruption): 5366 5367 -> tools/mkimage -l examples/uImage.TQM850L 5368 Image Name: 2.4.4 kernel for TQM850L 5369 Created: Wed Jul 19 02:34:59 2000 5370 Image Type: PowerPC Linux Kernel Image (gzip compressed) 5371 Data Size: 335725 Bytes = 327.86 kB = 0.32 MB 5372 Load Address: 0x00000000 5373 Entry Point: 0x00000000 5374 5375NOTE: for embedded systems where boot time is critical you can trade 5376speed for memory and install an UNCOMPRESSED image instead: this 5377needs more space in Flash, but boots much faster since it does not 5378need to be uncompressed: 5379 5380 -> gunzip /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/powerpc/coffboot/vmlinux.gz 5381 -> tools/mkimage -n '2.4.4 kernel for TQM850L' \ 5382 > -A ppc -O linux -T kernel -C none -a 0 -e 0 \ 5383 > -d /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/powerpc/coffboot/vmlinux \ 5384 > examples/uImage.TQM850L-uncompressed 5385 Image Name: 2.4.4 kernel for TQM850L 5386 Created: Wed Jul 19 02:34:59 2000 5387 Image Type: PowerPC Linux Kernel Image (uncompressed) 5388 Data Size: 792160 Bytes = 773.59 kB = 0.76 MB 5389 Load Address: 0x00000000 5390 Entry Point: 0x00000000 5391 5392 5393Similar you can build U-Boot images from a 'ramdisk.image.gz' file 5394when your kernel is intended to use an initial ramdisk: 5395 5396 -> tools/mkimage -n 'Simple Ramdisk Image' \ 5397 > -A ppc -O linux -T ramdisk -C gzip \ 5398 > -d /LinuxPPC/images/SIMPLE-ramdisk.image.gz examples/simple-initrd 5399 Image Name: Simple Ramdisk Image 5400 Created: Wed Jan 12 14:01:50 2000 5401 Image Type: PowerPC Linux RAMDisk Image (gzip compressed) 5402 Data Size: 566530 Bytes = 553.25 kB = 0.54 MB 5403 Load Address: 0x00000000 5404 Entry Point: 0x00000000 5405 5406The "dumpimage" is a tool to disassemble images built by mkimage. Its "-i" 5407option performs the converse operation of the mkimage's second form (the "-d" 5408option). Given an image built by mkimage, the dumpimage extracts a "data file" 5409from the image: 5410 5411 tools/dumpimage -i image -T type -p position data_file 5412 -i ==> extract from the 'image' a specific 'data_file' 5413 -T ==> set image type to 'type' 5414 -p ==> 'position' (starting at 0) of the 'data_file' inside the 'image' 5415 5416 5417Installing a Linux Image: 5418------------------------- 5419 5420To downloading a U-Boot image over the serial (console) interface, 5421you must convert the image to S-Record format: 5422 5423 objcopy -I binary -O srec examples/image examples/image.srec 5424 5425The 'objcopy' does not understand the information in the U-Boot 5426image header, so the resulting S-Record file will be relative to 5427address 0x00000000. To load it to a given address, you need to 5428specify the target address as 'offset' parameter with the 'loads' 5429command. 5430 5431Example: install the image to address 0x40100000 (which on the 5432TQM8xxL is in the first Flash bank): 5433 5434 => erase 40100000 401FFFFF 5435 5436 .......... done 5437 Erased 8 sectors 5438 5439 => loads 40100000 5440 ## Ready for S-Record download ... 5441 ~>examples/image.srec 5442 1 2 3 4 5 6 7 8 9 10 11 12 13 ... 5443 ... 5444 15989 15990 15991 15992 5445 [file transfer complete] 5446 [connected] 5447 ## Start Addr = 0x00000000 5448 5449 5450You can check the success of the download using the 'iminfo' command; 5451this includes a checksum verification so you can be sure no data 5452corruption happened: 5453 5454 => imi 40100000 5455 5456 ## Checking Image at 40100000 ... 5457 Image Name: 2.2.13 for initrd on TQM850L 5458 Image Type: PowerPC Linux Kernel Image (gzip compressed) 5459 Data Size: 335725 Bytes = 327 kB = 0 MB 5460 Load Address: 00000000 5461 Entry Point: 0000000c 5462 Verifying Checksum ... OK 5463 5464 5465Boot Linux: 5466----------- 5467 5468The "bootm" command is used to boot an application that is stored in 5469memory (RAM or Flash). In case of a Linux kernel image, the contents 5470of the "bootargs" environment variable is passed to the kernel as 5471parameters. You can check and modify this variable using the 5472"printenv" and "setenv" commands: 5473 5474 5475 => printenv bootargs 5476 bootargs=root=/dev/ram 5477 5478 => setenv bootargs root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2 5479 5480 => printenv bootargs 5481 bootargs=root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2 5482 5483 => bootm 40020000 5484 ## Booting Linux kernel at 40020000 ... 5485 Image Name: 2.2.13 for NFS on TQM850L 5486 Image Type: PowerPC Linux Kernel Image (gzip compressed) 5487 Data Size: 381681 Bytes = 372 kB = 0 MB 5488 Load Address: 00000000 5489 Entry Point: 0000000c 5490 Verifying Checksum ... OK 5491 Uncompressing Kernel Image ... OK 5492 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 5493 Boot arguments: root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2 5494 time_init: decrementer frequency = 187500000/60 5495 Calibrating delay loop... 49.77 BogoMIPS 5496 Memory: 15208k available (700k kernel code, 444k data, 32k init) [c0000000,c1000000] 5497 ... 5498 5499If you want to boot a Linux kernel with initial RAM disk, you pass 5500the memory addresses of both the kernel and the initrd image (PPBCOOT 5501format!) to the "bootm" command: 5502 5503 => imi 40100000 40200000 5504 5505 ## Checking Image at 40100000 ... 5506 Image Name: 2.2.13 for initrd on TQM850L 5507 Image Type: PowerPC Linux Kernel Image (gzip compressed) 5508 Data Size: 335725 Bytes = 327 kB = 0 MB 5509 Load Address: 00000000 5510 Entry Point: 0000000c 5511 Verifying Checksum ... OK 5512 5513 ## Checking Image at 40200000 ... 5514 Image Name: Simple Ramdisk Image 5515 Image Type: PowerPC Linux RAMDisk Image (gzip compressed) 5516 Data Size: 566530 Bytes = 553 kB = 0 MB 5517 Load Address: 00000000 5518 Entry Point: 00000000 5519 Verifying Checksum ... OK 5520 5521 => bootm 40100000 40200000 5522 ## Booting Linux kernel at 40100000 ... 5523 Image Name: 2.2.13 for initrd on TQM850L 5524 Image Type: PowerPC Linux Kernel Image (gzip compressed) 5525 Data Size: 335725 Bytes = 327 kB = 0 MB 5526 Load Address: 00000000 5527 Entry Point: 0000000c 5528 Verifying Checksum ... OK 5529 Uncompressing Kernel Image ... OK 5530 ## Loading RAMDisk Image at 40200000 ... 5531 Image Name: Simple Ramdisk Image 5532 Image Type: PowerPC Linux RAMDisk Image (gzip compressed) 5533 Data Size: 566530 Bytes = 553 kB = 0 MB 5534 Load Address: 00000000 5535 Entry Point: 00000000 5536 Verifying Checksum ... OK 5537 Loading Ramdisk ... OK 5538 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 5539 Boot arguments: root=/dev/ram 5540 time_init: decrementer frequency = 187500000/60 5541 Calibrating delay loop... 49.77 BogoMIPS 5542 ... 5543 RAMDISK: Compressed image found at block 0 5544 VFS: Mounted root (ext2 filesystem). 5545 5546 bash# 5547 5548Boot Linux and pass a flat device tree: 5549----------- 5550 5551First, U-Boot must be compiled with the appropriate defines. See the section 5552titled "Linux Kernel Interface" above for a more in depth explanation. The 5553following is an example of how to start a kernel and pass an updated 5554flat device tree: 5555 5556=> print oftaddr 5557oftaddr=0x300000 5558=> print oft 5559oft=oftrees/mpc8540ads.dtb 5560=> tftp $oftaddr $oft 5561Speed: 1000, full duplex 5562Using TSEC0 device 5563TFTP from server 192.168.1.1; our IP address is 192.168.1.101 5564Filename 'oftrees/mpc8540ads.dtb'. 5565Load address: 0x300000 5566Loading: # 5567done 5568Bytes transferred = 4106 (100a hex) 5569=> tftp $loadaddr $bootfile 5570Speed: 1000, full duplex 5571Using TSEC0 device 5572TFTP from server 192.168.1.1; our IP address is 192.168.1.2 5573Filename 'uImage'. 5574Load address: 0x200000 5575Loading:############ 5576done 5577Bytes transferred = 1029407 (fb51f hex) 5578=> print loadaddr 5579loadaddr=200000 5580=> print oftaddr 5581oftaddr=0x300000 5582=> bootm $loadaddr - $oftaddr 5583## Booting image at 00200000 ... 5584 Image Name: Linux-2.6.17-dirty 5585 Image Type: PowerPC Linux Kernel Image (gzip compressed) 5586 Data Size: 1029343 Bytes = 1005.2 kB 5587 Load Address: 00000000 5588 Entry Point: 00000000 5589 Verifying Checksum ... OK 5590 Uncompressing Kernel Image ... OK 5591Booting using flat device tree at 0x300000 5592Using MPC85xx ADS machine description 5593Memory CAM mapping: CAM0=256Mb, CAM1=256Mb, CAM2=0Mb residual: 0Mb 5594[snip] 5595 5596 5597More About U-Boot Image Types: 5598------------------------------ 5599 5600U-Boot supports the following image types: 5601 5602 "Standalone Programs" are directly runnable in the environment 5603 provided by U-Boot; it is expected that (if they behave 5604 well) you can continue to work in U-Boot after return from 5605 the Standalone Program. 5606 "OS Kernel Images" are usually images of some Embedded OS which 5607 will take over control completely. Usually these programs 5608 will install their own set of exception handlers, device 5609 drivers, set up the MMU, etc. - this means, that you cannot 5610 expect to re-enter U-Boot except by resetting the CPU. 5611 "RAMDisk Images" are more or less just data blocks, and their 5612 parameters (address, size) are passed to an OS kernel that is 5613 being started. 5614 "Multi-File Images" contain several images, typically an OS 5615 (Linux) kernel image and one or more data images like 5616 RAMDisks. This construct is useful for instance when you want 5617 to boot over the network using BOOTP etc., where the boot 5618 server provides just a single image file, but you want to get 5619 for instance an OS kernel and a RAMDisk image. 5620 5621 "Multi-File Images" start with a list of image sizes, each 5622 image size (in bytes) specified by an "uint32_t" in network 5623 byte order. This list is terminated by an "(uint32_t)0". 5624 Immediately after the terminating 0 follow the images, one by 5625 one, all aligned on "uint32_t" boundaries (size rounded up to 5626 a multiple of 4 bytes). 5627 5628 "Firmware Images" are binary images containing firmware (like 5629 U-Boot or FPGA images) which usually will be programmed to 5630 flash memory. 5631 5632 "Script files" are command sequences that will be executed by 5633 U-Boot's command interpreter; this feature is especially 5634 useful when you configure U-Boot to use a real shell (hush) 5635 as command interpreter. 5636 5637Booting the Linux zImage: 5638------------------------- 5639 5640On some platforms, it's possible to boot Linux zImage. This is done 5641using the "bootz" command. The syntax of "bootz" command is the same 5642as the syntax of "bootm" command. 5643 5644Note, defining the CONFIG_SUPPORT_RAW_INITRD allows user to supply 5645kernel with raw initrd images. The syntax is slightly different, the 5646address of the initrd must be augmented by it's size, in the following 5647format: "<initrd addres>:<initrd size>". 5648 5649 5650Standalone HOWTO: 5651================= 5652 5653One of the features of U-Boot is that you can dynamically load and 5654run "standalone" applications, which can use some resources of 5655U-Boot like console I/O functions or interrupt services. 5656 5657Two simple examples are included with the sources: 5658 5659"Hello World" Demo: 5660------------------- 5661 5662'examples/hello_world.c' contains a small "Hello World" Demo 5663application; it is automatically compiled when you build U-Boot. 5664It's configured to run at address 0x00040004, so you can play with it 5665like that: 5666 5667 => loads 5668 ## Ready for S-Record download ... 5669 ~>examples/hello_world.srec 5670 1 2 3 4 5 6 7 8 9 10 11 ... 5671 [file transfer complete] 5672 [connected] 5673 ## Start Addr = 0x00040004 5674 5675 => go 40004 Hello World! This is a test. 5676 ## Starting application at 0x00040004 ... 5677 Hello World 5678 argc = 7 5679 argv[0] = "40004" 5680 argv[1] = "Hello" 5681 argv[2] = "World!" 5682 argv[3] = "This" 5683 argv[4] = "is" 5684 argv[5] = "a" 5685 argv[6] = "test." 5686 argv[7] = "<NULL>" 5687 Hit any key to exit ... 5688 5689 ## Application terminated, rc = 0x0 5690 5691Another example, which demonstrates how to register a CPM interrupt 5692handler with the U-Boot code, can be found in 'examples/timer.c'. 5693Here, a CPM timer is set up to generate an interrupt every second. 5694The interrupt service routine is trivial, just printing a '.' 5695character, but this is just a demo program. The application can be 5696controlled by the following keys: 5697 5698 ? - print current values og the CPM Timer registers 5699 b - enable interrupts and start timer 5700 e - stop timer and disable interrupts 5701 q - quit application 5702 5703 => loads 5704 ## Ready for S-Record download ... 5705 ~>examples/timer.srec 5706 1 2 3 4 5 6 7 8 9 10 11 ... 5707 [file transfer complete] 5708 [connected] 5709 ## Start Addr = 0x00040004 5710 5711 => go 40004 5712 ## Starting application at 0x00040004 ... 5713 TIMERS=0xfff00980 5714 Using timer 1 5715 tgcr @ 0xfff00980, tmr @ 0xfff00990, trr @ 0xfff00994, tcr @ 0xfff00998, tcn @ 0xfff0099c, ter @ 0xfff009b0 5716 5717Hit 'b': 5718 [q, b, e, ?] Set interval 1000000 us 5719 Enabling timer 5720Hit '?': 5721 [q, b, e, ?] ........ 5722 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0xef6, ter=0x0 5723Hit '?': 5724 [q, b, e, ?] . 5725 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x2ad4, ter=0x0 5726Hit '?': 5727 [q, b, e, ?] . 5728 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x1efc, ter=0x0 5729Hit '?': 5730 [q, b, e, ?] . 5731 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x169d, ter=0x0 5732Hit 'e': 5733 [q, b, e, ?] ...Stopping timer 5734Hit 'q': 5735 [q, b, e, ?] ## Application terminated, rc = 0x0 5736 5737 5738Minicom warning: 5739================ 5740 5741Over time, many people have reported problems when trying to use the 5742"minicom" terminal emulation program for serial download. I (wd) 5743consider minicom to be broken, and recommend not to use it. Under 5744Unix, I recommend to use C-Kermit for general purpose use (and 5745especially for kermit binary protocol download ("loadb" command), and 5746use "cu" for S-Record download ("loads" command). See 5747http://www.denx.de/wiki/view/DULG/SystemSetup#Section_4.3. 5748for help with kermit. 5749 5750 5751Nevertheless, if you absolutely want to use it try adding this 5752configuration to your "File transfer protocols" section: 5753 5754 Name Program Name U/D FullScr IO-Red. Multi 5755 X kermit /usr/bin/kermit -i -l %l -s Y U Y N N 5756 Y kermit /usr/bin/kermit -i -l %l -r N D Y N N 5757 5758 5759NetBSD Notes: 5760============= 5761 5762Starting at version 0.9.2, U-Boot supports NetBSD both as host 5763(build U-Boot) and target system (boots NetBSD/mpc8xx). 5764 5765Building requires a cross environment; it is known to work on 5766NetBSD/i386 with the cross-powerpc-netbsd-1.3 package (you will also 5767need gmake since the Makefiles are not compatible with BSD make). 5768Note that the cross-powerpc package does not install include files; 5769attempting to build U-Boot will fail because <machine/ansi.h> is 5770missing. This file has to be installed and patched manually: 5771 5772 # cd /usr/pkg/cross/powerpc-netbsd/include 5773 # mkdir powerpc 5774 # ln -s powerpc machine 5775 # cp /usr/src/sys/arch/powerpc/include/ansi.h powerpc/ansi.h 5776 # ${EDIT} powerpc/ansi.h ## must remove __va_list, _BSD_VA_LIST 5777 5778Native builds *don't* work due to incompatibilities between native 5779and U-Boot include files. 5780 5781Booting assumes that (the first part of) the image booted is a 5782stage-2 loader which in turn loads and then invokes the kernel 5783proper. Loader sources will eventually appear in the NetBSD source 5784tree (probably in sys/arc/mpc8xx/stand/u-boot_stage2/); in the 5785meantime, see ftp://ftp.denx.de/pub/u-boot/ppcboot_stage2.tar.gz 5786 5787 5788Implementation Internals: 5789========================= 5790 5791The following is not intended to be a complete description of every 5792implementation detail. However, it should help to understand the 5793inner workings of U-Boot and make it easier to port it to custom 5794hardware. 5795 5796 5797Initial Stack, Global Data: 5798--------------------------- 5799 5800The implementation of U-Boot is complicated by the fact that U-Boot 5801starts running out of ROM (flash memory), usually without access to 5802system RAM (because the memory controller is not initialized yet). 5803This means that we don't have writable Data or BSS segments, and BSS 5804is not initialized as zero. To be able to get a C environment working 5805at all, we have to allocate at least a minimal stack. Implementation 5806options for this are defined and restricted by the CPU used: Some CPU 5807models provide on-chip memory (like the IMMR area on MPC8xx and 5808MPC826x processors), on others (parts of) the data cache can be 5809locked as (mis-) used as memory, etc. 5810 5811 Chris Hallinan posted a good summary of these issues to the 5812 U-Boot mailing list: 5813 5814 Subject: RE: [U-Boot-Users] RE: More On Memory Bank x (nothingness)? 5815 From: "Chris Hallinan" <clh@net1plus.com> 5816 Date: Mon, 10 Feb 2003 16:43:46 -0500 (22:43 MET) 5817 ... 5818 5819 Correct me if I'm wrong, folks, but the way I understand it 5820 is this: Using DCACHE as initial RAM for Stack, etc, does not 5821 require any physical RAM backing up the cache. The cleverness 5822 is that the cache is being used as a temporary supply of 5823 necessary storage before the SDRAM controller is setup. It's 5824 beyond the scope of this list to explain the details, but you 5825 can see how this works by studying the cache architecture and 5826 operation in the architecture and processor-specific manuals. 5827 5828 OCM is On Chip Memory, which I believe the 405GP has 4K. It 5829 is another option for the system designer to use as an 5830 initial stack/RAM area prior to SDRAM being available. Either 5831 option should work for you. Using CS 4 should be fine if your 5832 board designers haven't used it for something that would 5833 cause you grief during the initial boot! It is frequently not 5834 used. 5835 5836 CONFIG_SYS_INIT_RAM_ADDR should be somewhere that won't interfere 5837 with your processor/board/system design. The default value 5838 you will find in any recent u-boot distribution in 5839 walnut.h should work for you. I'd set it to a value larger 5840 than your SDRAM module. If you have a 64MB SDRAM module, set 5841 it above 400_0000. Just make sure your board has no resources 5842 that are supposed to respond to that address! That code in 5843 start.S has been around a while and should work as is when 5844 you get the config right. 5845 5846 -Chris Hallinan 5847 DS4.COM, Inc. 5848 5849It is essential to remember this, since it has some impact on the C 5850code for the initialization procedures: 5851 5852* Initialized global data (data segment) is read-only. Do not attempt 5853 to write it. 5854 5855* Do not use any uninitialized global data (or implicitly initialized 5856 as zero data - BSS segment) at all - this is undefined, initiali- 5857 zation is performed later (when relocating to RAM). 5858 5859* Stack space is very limited. Avoid big data buffers or things like 5860 that. 5861 5862Having only the stack as writable memory limits means we cannot use 5863normal global data to share information between the code. But it 5864turned out that the implementation of U-Boot can be greatly 5865simplified by making a global data structure (gd_t) available to all 5866functions. We could pass a pointer to this data as argument to _all_ 5867functions, but this would bloat the code. Instead we use a feature of 5868the GCC compiler (Global Register Variables) to share the data: we 5869place a pointer (gd) to the global data into a register which we 5870reserve for this purpose. 5871 5872When choosing a register for such a purpose we are restricted by the 5873relevant (E)ABI specifications for the current architecture, and by 5874GCC's implementation. 5875 5876For PowerPC, the following registers have specific use: 5877 R1: stack pointer 5878 R2: reserved for system use 5879 R3-R4: parameter passing and return values 5880 R5-R10: parameter passing 5881 R13: small data area pointer 5882 R30: GOT pointer 5883 R31: frame pointer 5884 5885 (U-Boot also uses R12 as internal GOT pointer. r12 5886 is a volatile register so r12 needs to be reset when 5887 going back and forth between asm and C) 5888 5889 ==> U-Boot will use R2 to hold a pointer to the global data 5890 5891 Note: on PPC, we could use a static initializer (since the 5892 address of the global data structure is known at compile time), 5893 but it turned out that reserving a register results in somewhat 5894 smaller code - although the code savings are not that big (on 5895 average for all boards 752 bytes for the whole U-Boot image, 5896 624 text + 127 data). 5897 5898On ARM, the following registers are used: 5899 5900 R0: function argument word/integer result 5901 R1-R3: function argument word 5902 R9: platform specific 5903 R10: stack limit (used only if stack checking is enabled) 5904 R11: argument (frame) pointer 5905 R12: temporary workspace 5906 R13: stack pointer 5907 R14: link register 5908 R15: program counter 5909 5910 ==> U-Boot will use R9 to hold a pointer to the global data 5911 5912 Note: on ARM, only R_ARM_RELATIVE relocations are supported. 5913 5914On Nios II, the ABI is documented here: 5915 http://www.altera.com/literature/hb/nios2/n2cpu_nii51016.pdf 5916 5917 ==> U-Boot will use gp to hold a pointer to the global data 5918 5919 Note: on Nios II, we give "-G0" option to gcc and don't use gp 5920 to access small data sections, so gp is free. 5921 5922On NDS32, the following registers are used: 5923 5924 R0-R1: argument/return 5925 R2-R5: argument 5926 R15: temporary register for assembler 5927 R16: trampoline register 5928 R28: frame pointer (FP) 5929 R29: global pointer (GP) 5930 R30: link register (LP) 5931 R31: stack pointer (SP) 5932 PC: program counter (PC) 5933 5934 ==> U-Boot will use R10 to hold a pointer to the global data 5935 5936NOTE: DECLARE_GLOBAL_DATA_PTR must be used with file-global scope, 5937or current versions of GCC may "optimize" the code too much. 5938 5939Memory Management: 5940------------------ 5941 5942U-Boot runs in system state and uses physical addresses, i.e. the 5943MMU is not used either for address mapping nor for memory protection. 5944 5945The available memory is mapped to fixed addresses using the memory 5946controller. In this process, a contiguous block is formed for each 5947memory type (Flash, SDRAM, SRAM), even when it consists of several 5948physical memory banks. 5949 5950U-Boot is installed in the first 128 kB of the first Flash bank (on 5951TQM8xxL modules this is the range 0x40000000 ... 0x4001FFFF). After 5952booting and sizing and initializing DRAM, the code relocates itself 5953to the upper end of DRAM. Immediately below the U-Boot code some 5954memory is reserved for use by malloc() [see CONFIG_SYS_MALLOC_LEN 5955configuration setting]. Below that, a structure with global Board 5956Info data is placed, followed by the stack (growing downward). 5957 5958Additionally, some exception handler code is copied to the low 8 kB 5959of DRAM (0x00000000 ... 0x00001FFF). 5960 5961So a typical memory configuration with 16 MB of DRAM could look like 5962this: 5963 5964 0x0000 0000 Exception Vector code 5965 : 5966 0x0000 1FFF 5967 0x0000 2000 Free for Application Use 5968 : 5969 : 5970 5971 : 5972 : 5973 0x00FB FF20 Monitor Stack (Growing downward) 5974 0x00FB FFAC Board Info Data and permanent copy of global data 5975 0x00FC 0000 Malloc Arena 5976 : 5977 0x00FD FFFF 5978 0x00FE 0000 RAM Copy of Monitor Code 5979 ... eventually: LCD or video framebuffer 5980 ... eventually: pRAM (Protected RAM - unchanged by reset) 5981 0x00FF FFFF [End of RAM] 5982 5983 5984System Initialization: 5985---------------------- 5986 5987In the reset configuration, U-Boot starts at the reset entry point 5988(on most PowerPC systems at address 0x00000100). Because of the reset 5989configuration for CS0# this is a mirror of the on board Flash memory. 5990To be able to re-map memory U-Boot then jumps to its link address. 5991To be able to implement the initialization code in C, a (small!) 5992initial stack is set up in the internal Dual Ported RAM (in case CPUs 5993which provide such a feature like MPC8xx or MPC8260), or in a locked 5994part of the data cache. After that, U-Boot initializes the CPU core, 5995the caches and the SIU. 5996 5997Next, all (potentially) available memory banks are mapped using a 5998preliminary mapping. For example, we put them on 512 MB boundaries 5999(multiples of 0x20000000: SDRAM on 0x00000000 and 0x20000000, Flash 6000on 0x40000000 and 0x60000000, SRAM on 0x80000000). Then UPM A is 6001programmed for SDRAM access. Using the temporary configuration, a 6002simple memory test is run that determines the size of the SDRAM 6003banks. 6004 6005When there is more than one SDRAM bank, and the banks are of 6006different size, the largest is mapped first. For equal size, the first 6007bank (CS2#) is mapped first. The first mapping is always for address 60080x00000000, with any additional banks following immediately to create 6009contiguous memory starting from 0. 6010 6011Then, the monitor installs itself at the upper end of the SDRAM area 6012and allocates memory for use by malloc() and for the global Board 6013Info data; also, the exception vector code is copied to the low RAM 6014pages, and the final stack is set up. 6015 6016Only after this relocation will you have a "normal" C environment; 6017until that you are restricted in several ways, mostly because you are 6018running from ROM, and because the code will have to be relocated to a 6019new address in RAM. 6020 6021 6022U-Boot Porting Guide: 6023---------------------- 6024 6025[Based on messages by Jerry Van Baren in the U-Boot-Users mailing 6026list, October 2002] 6027 6028 6029int main(int argc, char *argv[]) 6030{ 6031 sighandler_t no_more_time; 6032 6033 signal(SIGALRM, no_more_time); 6034 alarm(PROJECT_DEADLINE - toSec (3 * WEEK)); 6035 6036 if (available_money > available_manpower) { 6037 Pay consultant to port U-Boot; 6038 return 0; 6039 } 6040 6041 Download latest U-Boot source; 6042 6043 Subscribe to u-boot mailing list; 6044 6045 if (clueless) 6046 email("Hi, I am new to U-Boot, how do I get started?"); 6047 6048 while (learning) { 6049 Read the README file in the top level directory; 6050 Read http://www.denx.de/twiki/bin/view/DULG/Manual; 6051 Read applicable doc/*.README; 6052 Read the source, Luke; 6053 /* find . -name "*.[chS]" | xargs grep -i <keyword> */ 6054 } 6055 6056 if (available_money > toLocalCurrency ($2500)) 6057 Buy a BDI3000; 6058 else 6059 Add a lot of aggravation and time; 6060 6061 if (a similar board exists) { /* hopefully... */ 6062 cp -a board/<similar> board/<myboard> 6063 cp include/configs/<similar>.h include/configs/<myboard>.h 6064 } else { 6065 Create your own board support subdirectory; 6066 Create your own board include/configs/<myboard>.h file; 6067 } 6068 Edit new board/<myboard> files 6069 Edit new include/configs/<myboard>.h 6070 6071 while (!accepted) { 6072 while (!running) { 6073 do { 6074 Add / modify source code; 6075 } until (compiles); 6076 Debug; 6077 if (clueless) 6078 email("Hi, I am having problems..."); 6079 } 6080 Send patch file to the U-Boot email list; 6081 if (reasonable critiques) 6082 Incorporate improvements from email list code review; 6083 else 6084 Defend code as written; 6085 } 6086 6087 return 0; 6088} 6089 6090void no_more_time (int sig) 6091{ 6092 hire_a_guru(); 6093} 6094 6095 6096Coding Standards: 6097----------------- 6098 6099All contributions to U-Boot should conform to the Linux kernel 6100coding style; see the file "Documentation/CodingStyle" and the script 6101"scripts/Lindent" in your Linux kernel source directory. 6102 6103Source files originating from a different project (for example the 6104MTD subsystem) are generally exempt from these guidelines and are not 6105reformatted to ease subsequent migration to newer versions of those 6106sources. 6107 6108Please note that U-Boot is implemented in C (and to some small parts in 6109Assembler); no C++ is used, so please do not use C++ style comments (//) 6110in your code. 6111 6112Please also stick to the following formatting rules: 6113- remove any trailing white space 6114- use TAB characters for indentation and vertical alignment, not spaces 6115- make sure NOT to use DOS '\r\n' line feeds 6116- do not add more than 2 consecutive empty lines to source files 6117- do not add trailing empty lines to source files 6118 6119Submissions which do not conform to the standards may be returned 6120with a request to reformat the changes. 6121 6122 6123Submitting Patches: 6124------------------- 6125 6126Since the number of patches for U-Boot is growing, we need to 6127establish some rules. Submissions which do not conform to these rules 6128may be rejected, even when they contain important and valuable stuff. 6129 6130Please see http://www.denx.de/wiki/U-Boot/Patches for details. 6131 6132Patches shall be sent to the u-boot mailing list <u-boot@lists.denx.de>; 6133see http://lists.denx.de/mailman/listinfo/u-boot 6134 6135When you send a patch, please include the following information with 6136it: 6137 6138* For bug fixes: a description of the bug and how your patch fixes 6139 this bug. Please try to include a way of demonstrating that the 6140 patch actually fixes something. 6141 6142* For new features: a description of the feature and your 6143 implementation. 6144 6145* A CHANGELOG entry as plaintext (separate from the patch) 6146 6147* For major contributions, add a MAINTAINERS file with your 6148 information and associated file and directory references. 6149 6150* When you add support for a new board, don't forget to add a 6151 maintainer e-mail address to the boards.cfg file, too. 6152 6153* If your patch adds new configuration options, don't forget to 6154 document these in the README file. 6155 6156* The patch itself. If you are using git (which is *strongly* 6157 recommended) you can easily generate the patch using the 6158 "git format-patch". If you then use "git send-email" to send it to 6159 the U-Boot mailing list, you will avoid most of the common problems 6160 with some other mail clients. 6161 6162 If you cannot use git, use "diff -purN OLD NEW". If your version of 6163 diff does not support these options, then get the latest version of 6164 GNU diff. 6165 6166 The current directory when running this command shall be the parent 6167 directory of the U-Boot source tree (i. e. please make sure that 6168 your patch includes sufficient directory information for the 6169 affected files). 6170 6171 We prefer patches as plain text. MIME attachments are discouraged, 6172 and compressed attachments must not be used. 6173 6174* If one logical set of modifications affects or creates several 6175 files, all these changes shall be submitted in a SINGLE patch file. 6176 6177* Changesets that contain different, unrelated modifications shall be 6178 submitted as SEPARATE patches, one patch per changeset. 6179 6180 6181Notes: 6182 6183* Before sending the patch, run the buildman script on your patched 6184 source tree and make sure that no errors or warnings are reported 6185 for any of the boards. 6186 6187* Keep your modifications to the necessary minimum: A patch 6188 containing several unrelated changes or arbitrary reformats will be 6189 returned with a request to re-formatting / split it. 6190 6191* If you modify existing code, make sure that your new code does not 6192 add to the memory footprint of the code ;-) Small is beautiful! 6193 When adding new features, these should compile conditionally only 6194 (using #ifdef), and the resulting code with the new feature 6195 disabled must not need more memory than the old code without your 6196 modification. 6197 6198* Remember that there is a size limit of 100 kB per message on the 6199 u-boot mailing list. Bigger patches will be moderated. If they are 6200 reasonable and not too big, they will be acknowledged. But patches 6201 bigger than the size limit should be avoided. 6202