1# 2# (C) Copyright 2000 - 2013 3# Wolfgang Denk, DENX Software Engineering, wd@denx.de. 4# 5# SPDX-License-Identifier: GPL-2.0+ 6# 7 8Summary: 9======== 10 11This directory contains the source code for U-Boot, a boot loader for 12Embedded boards based on PowerPC, ARM, MIPS and several other 13processors, which can be installed in a boot ROM and used to 14initialize and test the hardware or to download and run application 15code. 16 17The development of U-Boot is closely related to Linux: some parts of 18the source code originate in the Linux source tree, we have some 19header files in common, and special provision has been made to 20support booting of Linux images. 21 22Some attention has been paid to make this software easily 23configurable and extendable. For instance, all monitor commands are 24implemented with the same call interface, so that it's very easy to 25add new commands. Also, instead of permanently adding rarely used 26code (for instance hardware test utilities) to the monitor, you can 27load and run it dynamically. 28 29 30Status: 31======= 32 33In general, all boards for which a configuration option exists in the 34Makefile have been tested to some extent and can be considered 35"working". In fact, many of them are used in production systems. 36 37In case of problems see the CHANGELOG file to find out who contributed 38the specific port. In addition, there are various MAINTAINERS files 39scattered throughout the U-Boot source identifying the people or 40companies responsible for various boards and subsystems. 41 42Note: As of August, 2010, there is no longer a CHANGELOG file in the 43actual U-Boot source tree; however, it can be created dynamically 44from the Git log using: 45 46 make CHANGELOG 47 48 49Where to get help: 50================== 51 52In case you have questions about, problems with or contributions for 53U-Boot, you should send a message to the U-Boot mailing list at 54<u-boot@lists.denx.de>. There is also an archive of previous traffic 55on the mailing list - please search the archive before asking FAQ's. 56Please see http://lists.denx.de/pipermail/u-boot and 57http://dir.gmane.org/gmane.comp.boot-loaders.u-boot 58 59 60Where to get source code: 61========================= 62 63The U-Boot source code is maintained in the Git repository at 64git://www.denx.de/git/u-boot.git ; you can browse it online at 65http://www.denx.de/cgi-bin/gitweb.cgi?p=u-boot.git;a=summary 66 67The "snapshot" links on this page allow you to download tarballs of 68any version you might be interested in. Official releases are also 69available for FTP download from the ftp://ftp.denx.de/pub/u-boot/ 70directory. 71 72Pre-built (and tested) images are available from 73ftp://ftp.denx.de/pub/u-boot/images/ 74 75 76Where we come from: 77=================== 78 79- start from 8xxrom sources 80- create PPCBoot project (http://sourceforge.net/projects/ppcboot) 81- clean up code 82- make it easier to add custom boards 83- make it possible to add other [PowerPC] CPUs 84- extend functions, especially: 85 * Provide extended interface to Linux boot loader 86 * S-Record download 87 * network boot 88 * PCMCIA / CompactFlash / ATA disk / SCSI ... boot 89- create ARMBoot project (http://sourceforge.net/projects/armboot) 90- add other CPU families (starting with ARM) 91- create U-Boot project (http://sourceforge.net/projects/u-boot) 92- current project page: see http://www.denx.de/wiki/U-Boot 93 94 95Names and Spelling: 96=================== 97 98The "official" name of this project is "Das U-Boot". The spelling 99"U-Boot" shall be used in all written text (documentation, comments 100in source files etc.). Example: 101 102 This is the README file for the U-Boot project. 103 104File names etc. shall be based on the string "u-boot". Examples: 105 106 include/asm-ppc/u-boot.h 107 108 #include <asm/u-boot.h> 109 110Variable names, preprocessor constants etc. shall be either based on 111the string "u_boot" or on "U_BOOT". Example: 112 113 U_BOOT_VERSION u_boot_logo 114 IH_OS_U_BOOT u_boot_hush_start 115 116 117Versioning: 118=========== 119 120Starting with the release in October 2008, the names of the releases 121were changed from numerical release numbers without deeper meaning 122into a time stamp based numbering. Regular releases are identified by 123names consisting of the calendar year and month of the release date. 124Additional fields (if present) indicate release candidates or bug fix 125releases in "stable" maintenance trees. 126 127Examples: 128 U-Boot v2009.11 - Release November 2009 129 U-Boot v2009.11.1 - Release 1 in version November 2009 stable tree 130 U-Boot v2010.09-rc1 - Release candidate 1 for September 2010 release 131 132 133Directory Hierarchy: 134==================== 135 136/arch Architecture specific files 137 /arc Files generic to ARC architecture 138 /arm Files generic to ARM architecture 139 /avr32 Files generic to AVR32 architecture 140 /m68k Files generic to m68k architecture 141 /microblaze Files generic to microblaze architecture 142 /mips Files generic to MIPS architecture 143 /nds32 Files generic to NDS32 architecture 144 /nios2 Files generic to Altera NIOS2 architecture 145 /openrisc Files generic to OpenRISC architecture 146 /powerpc Files generic to PowerPC architecture 147 /sandbox Files generic to HW-independent "sandbox" 148 /sh Files generic to SH architecture 149 /x86 Files generic to x86 architecture 150/api Machine/arch independent API for external apps 151/board Board dependent files 152/cmd U-Boot commands functions 153/common Misc architecture independent functions 154/configs Board default configuration files 155/disk Code for disk drive partition handling 156/doc Documentation (don't expect too much) 157/drivers Commonly used device drivers 158/dts Contains Makefile for building internal U-Boot fdt. 159/examples Example code for standalone applications, etc. 160/fs Filesystem code (cramfs, ext2, jffs2, etc.) 161/include Header Files 162/lib Library routines generic to all architectures 163/Licenses Various license files 164/net Networking code 165/post Power On Self Test 166/scripts Various build scripts and Makefiles 167/test Various unit test files 168/tools Tools to build S-Record or U-Boot images, etc. 169 170Software Configuration: 171======================= 172 173Configuration is usually done using C preprocessor defines; the 174rationale behind that is to avoid dead code whenever possible. 175 176There are two classes of configuration variables: 177 178* Configuration _OPTIONS_: 179 These are selectable by the user and have names beginning with 180 "CONFIG_". 181 182* Configuration _SETTINGS_: 183 These depend on the hardware etc. and should not be meddled with if 184 you don't know what you're doing; they have names beginning with 185 "CONFIG_SYS_". 186 187Previously, all configuration was done by hand, which involved creating 188symbolic links and editing configuration files manually. More recently, 189U-Boot has added the Kbuild infrastructure used by the Linux kernel, 190allowing you to use the "make menuconfig" command to configure your 191build. 192 193 194Selection of Processor Architecture and Board Type: 195--------------------------------------------------- 196 197For all supported boards there are ready-to-use default 198configurations available; just type "make <board_name>_defconfig". 199 200Example: For a TQM823L module type: 201 202 cd u-boot 203 make TQM823L_defconfig 204 205Note: If you're looking for the default configuration file for a board 206you're sure used to be there but is now missing, check the file 207doc/README.scrapyard for a list of no longer supported boards. 208 209Sandbox Environment: 210-------------------- 211 212U-Boot can be built natively to run on a Linux host using the 'sandbox' 213board. This allows feature development which is not board- or architecture- 214specific to be undertaken on a native platform. The sandbox is also used to 215run some of U-Boot's tests. 216 217See board/sandbox/README.sandbox for more details. 218 219 220Board Initialisation Flow: 221-------------------------- 222 223This is the intended start-up flow for boards. This should apply for both 224SPL and U-Boot proper (i.e. they both follow the same rules). 225 226Note: "SPL" stands for "Secondary Program Loader," which is explained in 227more detail later in this file. 228 229At present, SPL mostly uses a separate code path, but the function names 230and roles of each function are the same. Some boards or architectures 231may not conform to this. At least most ARM boards which use 232CONFIG_SPL_FRAMEWORK conform to this. 233 234Execution typically starts with an architecture-specific (and possibly 235CPU-specific) start.S file, such as: 236 237 - arch/arm/cpu/armv7/start.S 238 - arch/powerpc/cpu/mpc83xx/start.S 239 - arch/mips/cpu/start.S 240 241and so on. From there, three functions are called; the purpose and 242limitations of each of these functions are described below. 243 244lowlevel_init(): 245 - purpose: essential init to permit execution to reach board_init_f() 246 - no global_data or BSS 247 - there is no stack (ARMv7 may have one but it will soon be removed) 248 - must not set up SDRAM or use console 249 - must only do the bare minimum to allow execution to continue to 250 board_init_f() 251 - this is almost never needed 252 - return normally from this function 253 254board_init_f(): 255 - purpose: set up the machine ready for running board_init_r(): 256 i.e. SDRAM and serial UART 257 - global_data is available 258 - stack is in SRAM 259 - BSS is not available, so you cannot use global/static variables, 260 only stack variables and global_data 261 262 Non-SPL-specific notes: 263 - dram_init() is called to set up DRAM. If already done in SPL this 264 can do nothing 265 266 SPL-specific notes: 267 - you can override the entire board_init_f() function with your own 268 version as needed. 269 - preloader_console_init() can be called here in extremis 270 - should set up SDRAM, and anything needed to make the UART work 271 - these is no need to clear BSS, it will be done by crt0.S 272 - must return normally from this function (don't call board_init_r() 273 directly) 274 275Here the BSS is cleared. For SPL, if CONFIG_SPL_STACK_R is defined, then at 276this point the stack and global_data are relocated to below 277CONFIG_SPL_STACK_R_ADDR. For non-SPL, U-Boot is relocated to run at the top of 278memory. 279 280board_init_r(): 281 - purpose: main execution, common code 282 - global_data is available 283 - SDRAM is available 284 - BSS is available, all static/global variables can be used 285 - execution eventually continues to main_loop() 286 287 Non-SPL-specific notes: 288 - U-Boot is relocated to the top of memory and is now running from 289 there. 290 291 SPL-specific notes: 292 - stack is optionally in SDRAM, if CONFIG_SPL_STACK_R is defined and 293 CONFIG_SPL_STACK_R_ADDR points into SDRAM 294 - preloader_console_init() can be called here - typically this is 295 done by defining CONFIG_SPL_BOARD_INIT and then supplying a 296 spl_board_init() function containing this call 297 - loads U-Boot or (in falcon mode) Linux 298 299 300 301Configuration Options: 302---------------------- 303 304Configuration depends on the combination of board and CPU type; all 305such information is kept in a configuration file 306"include/configs/<board_name>.h". 307 308Example: For a TQM823L module, all configuration settings are in 309"include/configs/TQM823L.h". 310 311 312Many of the options are named exactly as the corresponding Linux 313kernel configuration options. The intention is to make it easier to 314build a config tool - later. 315 316 317The following options need to be configured: 318 319- CPU Type: Define exactly one, e.g. CONFIG_MPC85XX. 320 321- Board Type: Define exactly one, e.g. CONFIG_MPC8540ADS. 322 323- CPU Daughterboard Type: (if CONFIG_ATSTK1000 is defined) 324 Define exactly one, e.g. CONFIG_ATSTK1002 325 326- Marvell Family Member 327 CONFIG_SYS_MVFS - define it if you want to enable 328 multiple fs option at one time 329 for marvell soc family 330 331- 8xx CPU Options: (if using an MPC8xx CPU) 332 CONFIG_8xx_GCLK_FREQ - deprecated: CPU clock if 333 get_gclk_freq() cannot work 334 e.g. if there is no 32KHz 335 reference PIT/RTC clock 336 CONFIG_8xx_OSCLK - PLL input clock (either EXTCLK 337 or XTAL/EXTAL) 338 339- 859/866/885 CPU options: (if using a MPC859 or MPC866 or MPC885 CPU): 340 CONFIG_SYS_8xx_CPUCLK_MIN 341 CONFIG_SYS_8xx_CPUCLK_MAX 342 CONFIG_8xx_CPUCLK_DEFAULT 343 See doc/README.MPC866 344 345 CONFIG_SYS_MEASURE_CPUCLK 346 347 Define this to measure the actual CPU clock instead 348 of relying on the correctness of the configured 349 values. Mostly useful for board bringup to make sure 350 the PLL is locked at the intended frequency. Note 351 that this requires a (stable) reference clock (32 kHz 352 RTC clock or CONFIG_SYS_8XX_XIN) 353 354 CONFIG_SYS_DELAYED_ICACHE 355 356 Define this option if you want to enable the 357 ICache only when Code runs from RAM. 358 359- 85xx CPU Options: 360 CONFIG_SYS_PPC64 361 362 Specifies that the core is a 64-bit PowerPC implementation (implements 363 the "64" category of the Power ISA). This is necessary for ePAPR 364 compliance, among other possible reasons. 365 366 CONFIG_SYS_FSL_TBCLK_DIV 367 368 Defines the core time base clock divider ratio compared to the 369 system clock. On most PQ3 devices this is 8, on newer QorIQ 370 devices it can be 16 or 32. The ratio varies from SoC to Soc. 371 372 CONFIG_SYS_FSL_PCIE_COMPAT 373 374 Defines the string to utilize when trying to match PCIe device 375 tree nodes for the given platform. 376 377 CONFIG_SYS_FSL_ERRATUM_A004510 378 379 Enables a workaround for erratum A004510. If set, 380 then CONFIG_SYS_FSL_ERRATUM_A004510_SVR_REV and 381 CONFIG_SYS_FSL_CORENET_SNOOPVEC_COREONLY must be set. 382 383 CONFIG_SYS_FSL_ERRATUM_A004510_SVR_REV 384 CONFIG_SYS_FSL_ERRATUM_A004510_SVR_REV2 (optional) 385 386 Defines one or two SoC revisions (low 8 bits of SVR) 387 for which the A004510 workaround should be applied. 388 389 The rest of SVR is either not relevant to the decision 390 of whether the erratum is present (e.g. p2040 versus 391 p2041) or is implied by the build target, which controls 392 whether CONFIG_SYS_FSL_ERRATUM_A004510 is set. 393 394 See Freescale App Note 4493 for more information about 395 this erratum. 396 397 CONFIG_A003399_NOR_WORKAROUND 398 Enables a workaround for IFC erratum A003399. It is only 399 required during NOR boot. 400 401 CONFIG_A008044_WORKAROUND 402 Enables a workaround for T1040/T1042 erratum A008044. It is only 403 required during NAND boot and valid for Rev 1.0 SoC revision 404 405 CONFIG_SYS_FSL_CORENET_SNOOPVEC_COREONLY 406 407 This is the value to write into CCSR offset 0x18600 408 according to the A004510 workaround. 409 410 CONFIG_SYS_FSL_DSP_DDR_ADDR 411 This value denotes start offset of DDR memory which is 412 connected exclusively to the DSP cores. 413 414 CONFIG_SYS_FSL_DSP_M2_RAM_ADDR 415 This value denotes start offset of M2 memory 416 which is directly connected to the DSP core. 417 418 CONFIG_SYS_FSL_DSP_M3_RAM_ADDR 419 This value denotes start offset of M3 memory which is directly 420 connected to the DSP core. 421 422 CONFIG_SYS_FSL_DSP_CCSRBAR_DEFAULT 423 This value denotes start offset of DSP CCSR space. 424 425 CONFIG_SYS_FSL_SINGLE_SOURCE_CLK 426 Single Source Clock is clocking mode present in some of FSL SoC's. 427 In this mode, a single differential clock is used to supply 428 clocks to the sysclock, ddrclock and usbclock. 429 430 CONFIG_SYS_CPC_REINIT_F 431 This CONFIG is defined when the CPC is configured as SRAM at the 432 time of U-Boot entry and is required to be re-initialized. 433 434 CONFIG_DEEP_SLEEP 435 Indicates this SoC supports deep sleep feature. If deep sleep is 436 supported, core will start to execute uboot when wakes up. 437 438- Generic CPU options: 439 CONFIG_SYS_GENERIC_GLOBAL_DATA 440 Defines global data is initialized in generic board board_init_f(). 441 If this macro is defined, global data is created and cleared in 442 generic board board_init_f(). Without this macro, architecture/board 443 should initialize global data before calling board_init_f(). 444 445 CONFIG_SYS_BIG_ENDIAN, CONFIG_SYS_LITTLE_ENDIAN 446 447 Defines the endianess of the CPU. Implementation of those 448 values is arch specific. 449 450 CONFIG_SYS_FSL_DDR 451 Freescale DDR driver in use. This type of DDR controller is 452 found in mpc83xx, mpc85xx, mpc86xx as well as some ARM core 453 SoCs. 454 455 CONFIG_SYS_FSL_DDR_ADDR 456 Freescale DDR memory-mapped register base. 457 458 CONFIG_SYS_FSL_DDR_EMU 459 Specify emulator support for DDR. Some DDR features such as 460 deskew training are not available. 461 462 CONFIG_SYS_FSL_DDRC_GEN1 463 Freescale DDR1 controller. 464 465 CONFIG_SYS_FSL_DDRC_GEN2 466 Freescale DDR2 controller. 467 468 CONFIG_SYS_FSL_DDRC_GEN3 469 Freescale DDR3 controller. 470 471 CONFIG_SYS_FSL_DDRC_GEN4 472 Freescale DDR4 controller. 473 474 CONFIG_SYS_FSL_DDRC_ARM_GEN3 475 Freescale DDR3 controller for ARM-based SoCs. 476 477 CONFIG_SYS_FSL_DDR1 478 Board config to use DDR1. It can be enabled for SoCs with 479 Freescale DDR1 or DDR2 controllers, depending on the board 480 implemetation. 481 482 CONFIG_SYS_FSL_DDR2 483 Board config to use DDR2. It can be enabled for SoCs with 484 Freescale DDR2 or DDR3 controllers, depending on the board 485 implementation. 486 487 CONFIG_SYS_FSL_DDR3 488 Board config to use DDR3. It can be enabled for SoCs with 489 Freescale DDR3 or DDR3L controllers. 490 491 CONFIG_SYS_FSL_DDR3L 492 Board config to use DDR3L. It can be enabled for SoCs with 493 DDR3L controllers. 494 495 CONFIG_SYS_FSL_DDR4 496 Board config to use DDR4. It can be enabled for SoCs with 497 DDR4 controllers. 498 499 CONFIG_SYS_FSL_IFC_BE 500 Defines the IFC controller register space as Big Endian 501 502 CONFIG_SYS_FSL_IFC_LE 503 Defines the IFC controller register space as Little Endian 504 505 CONFIG_SYS_FSL_IFC_CLK_DIV 506 Defines divider of platform clock(clock input to IFC controller). 507 508 CONFIG_SYS_FSL_LBC_CLK_DIV 509 Defines divider of platform clock(clock input to eLBC controller). 510 511 CONFIG_SYS_FSL_PBL_PBI 512 It enables addition of RCW (Power on reset configuration) in built image. 513 Please refer doc/README.pblimage for more details 514 515 CONFIG_SYS_FSL_PBL_RCW 516 It adds PBI(pre-boot instructions) commands in u-boot build image. 517 PBI commands can be used to configure SoC before it starts the execution. 518 Please refer doc/README.pblimage for more details 519 520 CONFIG_SPL_FSL_PBL 521 It adds a target to create boot binary having SPL binary in PBI format 522 concatenated with u-boot binary. 523 524 CONFIG_SYS_FSL_DDR_BE 525 Defines the DDR controller register space as Big Endian 526 527 CONFIG_SYS_FSL_DDR_LE 528 Defines the DDR controller register space as Little Endian 529 530 CONFIG_SYS_FSL_DDR_SDRAM_BASE_PHY 531 Physical address from the view of DDR controllers. It is the 532 same as CONFIG_SYS_DDR_SDRAM_BASE for all Power SoCs. But 533 it could be different for ARM SoCs. 534 535 CONFIG_SYS_FSL_DDR_INTLV_256B 536 DDR controller interleaving on 256-byte. This is a special 537 interleaving mode, handled by Dickens for Freescale layerscape 538 SoCs with ARM core. 539 540 CONFIG_SYS_FSL_DDR_MAIN_NUM_CTRLS 541 Number of controllers used as main memory. 542 543 CONFIG_SYS_FSL_OTHER_DDR_NUM_CTRLS 544 Number of controllers used for other than main memory. 545 546 CONFIG_SYS_FSL_HAS_DP_DDR 547 Defines the SoC has DP-DDR used for DPAA. 548 549 CONFIG_SYS_FSL_SEC_BE 550 Defines the SEC controller register space as Big Endian 551 552 CONFIG_SYS_FSL_SEC_LE 553 Defines the SEC controller register space as Little Endian 554 555- MIPS CPU options: 556 CONFIG_SYS_INIT_SP_OFFSET 557 558 Offset relative to CONFIG_SYS_SDRAM_BASE for initial stack 559 pointer. This is needed for the temporary stack before 560 relocation. 561 562 CONFIG_SYS_MIPS_CACHE_MODE 563 564 Cache operation mode for the MIPS CPU. 565 See also arch/mips/include/asm/mipsregs.h. 566 Possible values are: 567 CONF_CM_CACHABLE_NO_WA 568 CONF_CM_CACHABLE_WA 569 CONF_CM_UNCACHED 570 CONF_CM_CACHABLE_NONCOHERENT 571 CONF_CM_CACHABLE_CE 572 CONF_CM_CACHABLE_COW 573 CONF_CM_CACHABLE_CUW 574 CONF_CM_CACHABLE_ACCELERATED 575 576 CONFIG_SYS_XWAY_EBU_BOOTCFG 577 578 Special option for Lantiq XWAY SoCs for booting from NOR flash. 579 See also arch/mips/cpu/mips32/start.S. 580 581 CONFIG_XWAY_SWAP_BYTES 582 583 Enable compilation of tools/xway-swap-bytes needed for Lantiq 584 XWAY SoCs for booting from NOR flash. The U-Boot image needs to 585 be swapped if a flash programmer is used. 586 587- ARM options: 588 CONFIG_SYS_EXCEPTION_VECTORS_HIGH 589 590 Select high exception vectors of the ARM core, e.g., do not 591 clear the V bit of the c1 register of CP15. 592 593 COUNTER_FREQUENCY 594 Generic timer clock source frequency. 595 596 COUNTER_FREQUENCY_REAL 597 Generic timer clock source frequency if the real clock is 598 different from COUNTER_FREQUENCY, and can only be determined 599 at run time. 600 601- Tegra SoC options: 602 CONFIG_TEGRA_SUPPORT_NON_SECURE 603 604 Support executing U-Boot in non-secure (NS) mode. Certain 605 impossible actions will be skipped if the CPU is in NS mode, 606 such as ARM architectural timer initialization. 607 608- Linux Kernel Interface: 609 CONFIG_CLOCKS_IN_MHZ 610 611 U-Boot stores all clock information in Hz 612 internally. For binary compatibility with older Linux 613 kernels (which expect the clocks passed in the 614 bd_info data to be in MHz) the environment variable 615 "clocks_in_mhz" can be defined so that U-Boot 616 converts clock data to MHZ before passing it to the 617 Linux kernel. 618 When CONFIG_CLOCKS_IN_MHZ is defined, a definition of 619 "clocks_in_mhz=1" is automatically included in the 620 default environment. 621 622 CONFIG_MEMSIZE_IN_BYTES [relevant for MIPS only] 623 624 When transferring memsize parameter to Linux, some versions 625 expect it to be in bytes, others in MB. 626 Define CONFIG_MEMSIZE_IN_BYTES to make it in bytes. 627 628 CONFIG_OF_LIBFDT 629 630 New kernel versions are expecting firmware settings to be 631 passed using flattened device trees (based on open firmware 632 concepts). 633 634 CONFIG_OF_LIBFDT 635 * New libfdt-based support 636 * Adds the "fdt" command 637 * The bootm command automatically updates the fdt 638 639 OF_CPU - The proper name of the cpus node (only required for 640 MPC512X and MPC5xxx based boards). 641 OF_SOC - The proper name of the soc node (only required for 642 MPC512X and MPC5xxx based boards). 643 OF_TBCLK - The timebase frequency. 644 OF_STDOUT_PATH - The path to the console device 645 646 boards with QUICC Engines require OF_QE to set UCC MAC 647 addresses 648 649 CONFIG_OF_BOARD_SETUP 650 651 Board code has addition modification that it wants to make 652 to the flat device tree before handing it off to the kernel 653 654 CONFIG_OF_SYSTEM_SETUP 655 656 Other code has addition modification that it wants to make 657 to the flat device tree before handing it off to the kernel. 658 This causes ft_system_setup() to be called before booting 659 the kernel. 660 661 CONFIG_OF_IDE_FIXUP 662 663 U-Boot can detect if an IDE device is present or not. 664 If not, and this new config option is activated, U-Boot 665 removes the ATA node from the DTS before booting Linux, 666 so the Linux IDE driver does not probe the device and 667 crash. This is needed for buggy hardware (uc101) where 668 no pull down resistor is connected to the signal IDE5V_DD7. 669 670 CONFIG_MACH_TYPE [relevant for ARM only][mandatory] 671 672 This setting is mandatory for all boards that have only one 673 machine type and must be used to specify the machine type 674 number as it appears in the ARM machine registry 675 (see http://www.arm.linux.org.uk/developer/machines/). 676 Only boards that have multiple machine types supported 677 in a single configuration file and the machine type is 678 runtime discoverable, do not have to use this setting. 679 680- vxWorks boot parameters: 681 682 bootvx constructs a valid bootline using the following 683 environments variables: bootdev, bootfile, ipaddr, netmask, 684 serverip, gatewayip, hostname, othbootargs. 685 It loads the vxWorks image pointed bootfile. 686 687 Note: If a "bootargs" environment is defined, it will overwride 688 the defaults discussed just above. 689 690- Cache Configuration: 691 CONFIG_SYS_ICACHE_OFF - Do not enable instruction cache in U-Boot 692 CONFIG_SYS_DCACHE_OFF - Do not enable data cache in U-Boot 693 CONFIG_SYS_L2CACHE_OFF- Do not enable L2 cache in U-Boot 694 695- Cache Configuration for ARM: 696 CONFIG_SYS_L2_PL310 - Enable support for ARM PL310 L2 cache 697 controller 698 CONFIG_SYS_PL310_BASE - Physical base address of PL310 699 controller register space 700 701- Serial Ports: 702 CONFIG_PL010_SERIAL 703 704 Define this if you want support for Amba PrimeCell PL010 UARTs. 705 706 CONFIG_PL011_SERIAL 707 708 Define this if you want support for Amba PrimeCell PL011 UARTs. 709 710 CONFIG_PL011_CLOCK 711 712 If you have Amba PrimeCell PL011 UARTs, set this variable to 713 the clock speed of the UARTs. 714 715 CONFIG_PL01x_PORTS 716 717 If you have Amba PrimeCell PL010 or PL011 UARTs on your board, 718 define this to a list of base addresses for each (supported) 719 port. See e.g. include/configs/versatile.h 720 721 CONFIG_SERIAL_HW_FLOW_CONTROL 722 723 Define this variable to enable hw flow control in serial driver. 724 Current user of this option is drivers/serial/nsl16550.c driver 725 726- Console Interface: 727 Depending on board, define exactly one serial port 728 (like CONFIG_8xx_CONS_SMC1, CONFIG_8xx_CONS_SMC2, 729 CONFIG_8xx_CONS_SCC1, ...), or switch off the serial 730 console by defining CONFIG_8xx_CONS_NONE 731 732 Note: if CONFIG_8xx_CONS_NONE is defined, the serial 733 port routines must be defined elsewhere 734 (i.e. serial_init(), serial_getc(), ...) 735 736- Console Baudrate: 737 CONFIG_BAUDRATE - in bps 738 Select one of the baudrates listed in 739 CONFIG_SYS_BAUDRATE_TABLE, see below. 740 CONFIG_SYS_BRGCLK_PRESCALE, baudrate prescale 741 742- Console Rx buffer length 743 With CONFIG_SYS_SMC_RXBUFLEN it is possible to define 744 the maximum receive buffer length for the SMC. 745 This option is actual only for 82xx and 8xx possible. 746 If using CONFIG_SYS_SMC_RXBUFLEN also CONFIG_SYS_MAXIDLE 747 must be defined, to setup the maximum idle timeout for 748 the SMC. 749 750- Autoboot Command: 751 CONFIG_BOOTCOMMAND 752 Only needed when CONFIG_BOOTDELAY is enabled; 753 define a command string that is automatically executed 754 when no character is read on the console interface 755 within "Boot Delay" after reset. 756 757 CONFIG_BOOTARGS 758 This can be used to pass arguments to the bootm 759 command. The value of CONFIG_BOOTARGS goes into the 760 environment value "bootargs". 761 762 CONFIG_RAMBOOT and CONFIG_NFSBOOT 763 The value of these goes into the environment as 764 "ramboot" and "nfsboot" respectively, and can be used 765 as a convenience, when switching between booting from 766 RAM and NFS. 767 768- Bootcount: 769 CONFIG_BOOTCOUNT_LIMIT 770 Implements a mechanism for detecting a repeating reboot 771 cycle, see: 772 http://www.denx.de/wiki/view/DULG/UBootBootCountLimit 773 774 CONFIG_BOOTCOUNT_ENV 775 If no softreset save registers are found on the hardware 776 "bootcount" is stored in the environment. To prevent a 777 saveenv on all reboots, the environment variable 778 "upgrade_available" is used. If "upgrade_available" is 779 0, "bootcount" is always 0, if "upgrade_available" is 780 1 "bootcount" is incremented in the environment. 781 So the Userspace Applikation must set the "upgrade_available" 782 and "bootcount" variable to 0, if a boot was successfully. 783 784- Pre-Boot Commands: 785 CONFIG_PREBOOT 786 787 When this option is #defined, the existence of the 788 environment variable "preboot" will be checked 789 immediately before starting the CONFIG_BOOTDELAY 790 countdown and/or running the auto-boot command resp. 791 entering interactive mode. 792 793 This feature is especially useful when "preboot" is 794 automatically generated or modified. For an example 795 see the LWMON board specific code: here "preboot" is 796 modified when the user holds down a certain 797 combination of keys on the (special) keyboard when 798 booting the systems 799 800- Serial Download Echo Mode: 801 CONFIG_LOADS_ECHO 802 If defined to 1, all characters received during a 803 serial download (using the "loads" command) are 804 echoed back. This might be needed by some terminal 805 emulations (like "cu"), but may as well just take 806 time on others. This setting #define's the initial 807 value of the "loads_echo" environment variable. 808 809- Kgdb Serial Baudrate: (if CONFIG_CMD_KGDB is defined) 810 CONFIG_KGDB_BAUDRATE 811 Select one of the baudrates listed in 812 CONFIG_SYS_BAUDRATE_TABLE, see below. 813 814- Monitor Functions: 815 Monitor commands can be included or excluded 816 from the build by using the #include files 817 <config_cmd_all.h> and #undef'ing unwanted 818 commands, or adding #define's for wanted commands. 819 820 The default command configuration includes all commands 821 except those marked below with a "*". 822 823 CONFIG_CMD_AES AES 128 CBC encrypt/decrypt 824 CONFIG_CMD_ASKENV * ask for env variable 825 CONFIG_CMD_BDI bdinfo 826 CONFIG_CMD_BOOTD bootd 827 CONFIG_CMD_BOOTI * ARM64 Linux kernel Image support 828 CONFIG_CMD_CACHE * icache, dcache 829 CONFIG_CMD_CLK * clock command support 830 CONFIG_CMD_CONSOLE coninfo 831 CONFIG_CMD_CRC32 * crc32 832 CONFIG_CMD_DATE * support for RTC, date/time... 833 CONFIG_CMD_DHCP * DHCP support 834 CONFIG_CMD_DIAG * Diagnostics 835 CONFIG_CMD_DS4510 * ds4510 I2C gpio commands 836 CONFIG_CMD_DS4510_INFO * ds4510 I2C info command 837 CONFIG_CMD_DS4510_MEM * ds4510 I2C eeprom/sram commansd 838 CONFIG_CMD_DS4510_RST * ds4510 I2C rst command 839 CONFIG_CMD_DTT * Digital Therm and Thermostat 840 CONFIG_CMD_ECHO echo arguments 841 CONFIG_CMD_EDITENV edit env variable 842 CONFIG_CMD_EEPROM * EEPROM read/write support 843 CONFIG_CMD_EEPROM_LAYOUT* EEPROM layout aware commands 844 CONFIG_CMD_ELF * bootelf, bootvx 845 CONFIG_CMD_ENV_CALLBACK * display details about env callbacks 846 CONFIG_CMD_ENV_FLAGS * display details about env flags 847 CONFIG_CMD_ENV_EXISTS * check existence of env variable 848 CONFIG_CMD_EXPORTENV * export the environment 849 CONFIG_CMD_EXT2 * ext2 command support 850 CONFIG_CMD_EXT4 * ext4 command support 851 CONFIG_CMD_FS_GENERIC * filesystem commands (e.g. load, ls) 852 that work for multiple fs types 853 CONFIG_CMD_FS_UUID * Look up a filesystem UUID 854 CONFIG_CMD_SAVEENV saveenv 855 CONFIG_CMD_FDC * Floppy Disk Support 856 CONFIG_CMD_FAT * FAT command support 857 CONFIG_CMD_FLASH flinfo, erase, protect 858 CONFIG_CMD_FPGA FPGA device initialization support 859 CONFIG_CMD_FUSE * Device fuse support 860 CONFIG_CMD_GETTIME * Get time since boot 861 CONFIG_CMD_GO * the 'go' command (exec code) 862 CONFIG_CMD_GREPENV * search environment 863 CONFIG_CMD_HASH * calculate hash / digest 864 CONFIG_CMD_I2C * I2C serial bus support 865 CONFIG_CMD_IDE * IDE harddisk support 866 CONFIG_CMD_IMI iminfo 867 CONFIG_CMD_IMLS List all images found in NOR flash 868 CONFIG_CMD_IMLS_NAND * List all images found in NAND flash 869 CONFIG_CMD_IMMAP * IMMR dump support 870 CONFIG_CMD_IOTRACE * I/O tracing for debugging 871 CONFIG_CMD_IMPORTENV * import an environment 872 CONFIG_CMD_INI * import data from an ini file into the env 873 CONFIG_CMD_IRQ * irqinfo 874 CONFIG_CMD_ITEST Integer/string test of 2 values 875 CONFIG_CMD_JFFS2 * JFFS2 Support 876 CONFIG_CMD_KGDB * kgdb 877 CONFIG_CMD_LDRINFO * ldrinfo (display Blackfin loader) 878 CONFIG_CMD_LINK_LOCAL * link-local IP address auto-configuration 879 (169.254.*.*) 880 CONFIG_CMD_LOADB loadb 881 CONFIG_CMD_LOADS loads 882 CONFIG_CMD_MD5SUM * print md5 message digest 883 (requires CONFIG_CMD_MEMORY and CONFIG_MD5) 884 CONFIG_CMD_MEMINFO * Display detailed memory information 885 CONFIG_CMD_MEMORY md, mm, nm, mw, cp, cmp, crc, base, 886 loop, loopw 887 CONFIG_CMD_MEMTEST * mtest 888 CONFIG_CMD_MISC Misc functions like sleep etc 889 CONFIG_CMD_MMC * MMC memory mapped support 890 CONFIG_CMD_MII * MII utility commands 891 CONFIG_CMD_MTDPARTS * MTD partition support 892 CONFIG_CMD_NAND * NAND support 893 CONFIG_CMD_NET bootp, tftpboot, rarpboot 894 CONFIG_CMD_NFS NFS support 895 CONFIG_CMD_PCA953X * PCA953x I2C gpio commands 896 CONFIG_CMD_PCA953X_INFO * PCA953x I2C gpio info command 897 CONFIG_CMD_PCI * pciinfo 898 CONFIG_CMD_PCMCIA * PCMCIA support 899 CONFIG_CMD_PING * send ICMP ECHO_REQUEST to network 900 host 901 CONFIG_CMD_PORTIO * Port I/O 902 CONFIG_CMD_READ * Read raw data from partition 903 CONFIG_CMD_REGINFO * Register dump 904 CONFIG_CMD_RUN run command in env variable 905 CONFIG_CMD_SANDBOX * sb command to access sandbox features 906 CONFIG_CMD_SAVES * save S record dump 907 CONFIG_SCSI * SCSI Support 908 CONFIG_CMD_SDRAM * print SDRAM configuration information 909 (requires CONFIG_CMD_I2C) 910 CONFIG_CMD_SETGETDCR Support for DCR Register access 911 (4xx only) 912 CONFIG_CMD_SF * Read/write/erase SPI NOR flash 913 CONFIG_CMD_SHA1SUM * print sha1 memory digest 914 (requires CONFIG_CMD_MEMORY) 915 CONFIG_CMD_SOFTSWITCH * Soft switch setting command for BF60x 916 CONFIG_CMD_SOURCE "source" command Support 917 CONFIG_CMD_SPI * SPI serial bus support 918 CONFIG_CMD_TFTPSRV * TFTP transfer in server mode 919 CONFIG_CMD_TFTPPUT * TFTP put command (upload) 920 CONFIG_CMD_TIME * run command and report execution time (ARM specific) 921 CONFIG_CMD_TIMER * access to the system tick timer 922 CONFIG_CMD_USB * USB support 923 CONFIG_CMD_CDP * Cisco Discover Protocol support 924 CONFIG_CMD_MFSL * Microblaze FSL support 925 CONFIG_CMD_XIMG Load part of Multi Image 926 CONFIG_CMD_UUID * Generate random UUID or GUID string 927 928 EXAMPLE: If you want all functions except of network 929 support you can write: 930 931 #include "config_cmd_all.h" 932 #undef CONFIG_CMD_NET 933 934 Other Commands: 935 fdt (flattened device tree) command: CONFIG_OF_LIBFDT 936 937 Note: Don't enable the "icache" and "dcache" commands 938 (configuration option CONFIG_CMD_CACHE) unless you know 939 what you (and your U-Boot users) are doing. Data 940 cache cannot be enabled on systems like the 8xx or 941 8260 (where accesses to the IMMR region must be 942 uncached), and it cannot be disabled on all other 943 systems where we (mis-) use the data cache to hold an 944 initial stack and some data. 945 946 947 XXX - this list needs to get updated! 948 949- Removal of commands 950 If no commands are needed to boot, you can disable 951 CONFIG_CMDLINE to remove them. In this case, the command line 952 will not be available, and when U-Boot wants to execute the 953 boot command (on start-up) it will call board_run_command() 954 instead. This can reduce image size significantly for very 955 simple boot procedures. 956 957- Regular expression support: 958 CONFIG_REGEX 959 If this variable is defined, U-Boot is linked against 960 the SLRE (Super Light Regular Expression) library, 961 which adds regex support to some commands, as for 962 example "env grep" and "setexpr". 963 964- Device tree: 965 CONFIG_OF_CONTROL 966 If this variable is defined, U-Boot will use a device tree 967 to configure its devices, instead of relying on statically 968 compiled #defines in the board file. This option is 969 experimental and only available on a few boards. The device 970 tree is available in the global data as gd->fdt_blob. 971 972 U-Boot needs to get its device tree from somewhere. This can 973 be done using one of the two options below: 974 975 CONFIG_OF_EMBED 976 If this variable is defined, U-Boot will embed a device tree 977 binary in its image. This device tree file should be in the 978 board directory and called <soc>-<board>.dts. The binary file 979 is then picked up in board_init_f() and made available through 980 the global data structure as gd->blob. 981 982 CONFIG_OF_SEPARATE 983 If this variable is defined, U-Boot will build a device tree 984 binary. It will be called u-boot.dtb. Architecture-specific 985 code will locate it at run-time. Generally this works by: 986 987 cat u-boot.bin u-boot.dtb >image.bin 988 989 and in fact, U-Boot does this for you, creating a file called 990 u-boot-dtb.bin which is useful in the common case. You can 991 still use the individual files if you need something more 992 exotic. 993 994- Watchdog: 995 CONFIG_WATCHDOG 996 If this variable is defined, it enables watchdog 997 support for the SoC. There must be support in the SoC 998 specific code for a watchdog. For the 8xx and 8260 999 CPUs, the SIU Watchdog feature is enabled in the SYPCR 1000 register. When supported for a specific SoC is 1001 available, then no further board specific code should 1002 be needed to use it. 1003 1004 CONFIG_HW_WATCHDOG 1005 When using a watchdog circuitry external to the used 1006 SoC, then define this variable and provide board 1007 specific code for the "hw_watchdog_reset" function. 1008 1009 CONFIG_AT91_HW_WDT_TIMEOUT 1010 specify the timeout in seconds. default 2 seconds. 1011 1012- U-Boot Version: 1013 CONFIG_VERSION_VARIABLE 1014 If this variable is defined, an environment variable 1015 named "ver" is created by U-Boot showing the U-Boot 1016 version as printed by the "version" command. 1017 Any change to this variable will be reverted at the 1018 next reset. 1019 1020- Real-Time Clock: 1021 1022 When CONFIG_CMD_DATE is selected, the type of the RTC 1023 has to be selected, too. Define exactly one of the 1024 following options: 1025 1026 CONFIG_RTC_MPC8xx - use internal RTC of MPC8xx 1027 CONFIG_RTC_PCF8563 - use Philips PCF8563 RTC 1028 CONFIG_RTC_MC13XXX - use MC13783 or MC13892 RTC 1029 CONFIG_RTC_MC146818 - use MC146818 RTC 1030 CONFIG_RTC_DS1307 - use Maxim, Inc. DS1307 RTC 1031 CONFIG_RTC_DS1337 - use Maxim, Inc. DS1337 RTC 1032 CONFIG_RTC_DS1338 - use Maxim, Inc. DS1338 RTC 1033 CONFIG_RTC_DS1339 - use Maxim, Inc. DS1339 RTC 1034 CONFIG_RTC_DS164x - use Dallas DS164x RTC 1035 CONFIG_RTC_ISL1208 - use Intersil ISL1208 RTC 1036 CONFIG_RTC_MAX6900 - use Maxim, Inc. MAX6900 RTC 1037 CONFIG_SYS_RTC_DS1337_NOOSC - Turn off the OSC output for DS1337 1038 CONFIG_SYS_RV3029_TCR - enable trickle charger on 1039 RV3029 RTC. 1040 1041 Note that if the RTC uses I2C, then the I2C interface 1042 must also be configured. See I2C Support, below. 1043 1044- GPIO Support: 1045 CONFIG_PCA953X - use NXP's PCA953X series I2C GPIO 1046 1047 The CONFIG_SYS_I2C_PCA953X_WIDTH option specifies a list of 1048 chip-ngpio pairs that tell the PCA953X driver the number of 1049 pins supported by a particular chip. 1050 1051 Note that if the GPIO device uses I2C, then the I2C interface 1052 must also be configured. See I2C Support, below. 1053 1054- I/O tracing: 1055 When CONFIG_IO_TRACE is selected, U-Boot intercepts all I/O 1056 accesses and can checksum them or write a list of them out 1057 to memory. See the 'iotrace' command for details. This is 1058 useful for testing device drivers since it can confirm that 1059 the driver behaves the same way before and after a code 1060 change. Currently this is supported on sandbox and arm. To 1061 add support for your architecture, add '#include <iotrace.h>' 1062 to the bottom of arch/<arch>/include/asm/io.h and test. 1063 1064 Example output from the 'iotrace stats' command is below. 1065 Note that if the trace buffer is exhausted, the checksum will 1066 still continue to operate. 1067 1068 iotrace is enabled 1069 Start: 10000000 (buffer start address) 1070 Size: 00010000 (buffer size) 1071 Offset: 00000120 (current buffer offset) 1072 Output: 10000120 (start + offset) 1073 Count: 00000018 (number of trace records) 1074 CRC32: 9526fb66 (CRC32 of all trace records) 1075 1076- Timestamp Support: 1077 1078 When CONFIG_TIMESTAMP is selected, the timestamp 1079 (date and time) of an image is printed by image 1080 commands like bootm or iminfo. This option is 1081 automatically enabled when you select CONFIG_CMD_DATE . 1082 1083- Partition Labels (disklabels) Supported: 1084 Zero or more of the following: 1085 CONFIG_MAC_PARTITION Apple's MacOS partition table. 1086 CONFIG_DOS_PARTITION MS Dos partition table, traditional on the 1087 Intel architecture, USB sticks, etc. 1088 CONFIG_ISO_PARTITION ISO partition table, used on CDROM etc. 1089 CONFIG_EFI_PARTITION GPT partition table, common when EFI is the 1090 bootloader. Note 2TB partition limit; see 1091 disk/part_efi.c 1092 CONFIG_MTD_PARTITIONS Memory Technology Device partition table. 1093 1094 If IDE or SCSI support is enabled (CONFIG_CMD_IDE or 1095 CONFIG_SCSI) you must configure support for at 1096 least one non-MTD partition type as well. 1097 1098- IDE Reset method: 1099 CONFIG_IDE_RESET_ROUTINE - this is defined in several 1100 board configurations files but used nowhere! 1101 1102 CONFIG_IDE_RESET - is this is defined, IDE Reset will 1103 be performed by calling the function 1104 ide_set_reset(int reset) 1105 which has to be defined in a board specific file 1106 1107- ATAPI Support: 1108 CONFIG_ATAPI 1109 1110 Set this to enable ATAPI support. 1111 1112- LBA48 Support 1113 CONFIG_LBA48 1114 1115 Set this to enable support for disks larger than 137GB 1116 Also look at CONFIG_SYS_64BIT_LBA. 1117 Whithout these , LBA48 support uses 32bit variables and will 'only' 1118 support disks up to 2.1TB. 1119 1120 CONFIG_SYS_64BIT_LBA: 1121 When enabled, makes the IDE subsystem use 64bit sector addresses. 1122 Default is 32bit. 1123 1124- SCSI Support: 1125 At the moment only there is only support for the 1126 SYM53C8XX SCSI controller; define 1127 CONFIG_SCSI_SYM53C8XX to enable it. 1128 1129 CONFIG_SYS_SCSI_MAX_LUN [8], CONFIG_SYS_SCSI_MAX_SCSI_ID [7] and 1130 CONFIG_SYS_SCSI_MAX_DEVICE [CONFIG_SYS_SCSI_MAX_SCSI_ID * 1131 CONFIG_SYS_SCSI_MAX_LUN] can be adjusted to define the 1132 maximum numbers of LUNs, SCSI ID's and target 1133 devices. 1134 CONFIG_SYS_SCSI_SYM53C8XX_CCF to fix clock timing (80Mhz) 1135 1136 The environment variable 'scsidevs' is set to the number of 1137 SCSI devices found during the last scan. 1138 1139- NETWORK Support (PCI): 1140 CONFIG_E1000 1141 Support for Intel 8254x/8257x gigabit chips. 1142 1143 CONFIG_E1000_SPI 1144 Utility code for direct access to the SPI bus on Intel 8257x. 1145 This does not do anything useful unless you set at least one 1146 of CONFIG_CMD_E1000 or CONFIG_E1000_SPI_GENERIC. 1147 1148 CONFIG_E1000_SPI_GENERIC 1149 Allow generic access to the SPI bus on the Intel 8257x, for 1150 example with the "sspi" command. 1151 1152 CONFIG_CMD_E1000 1153 Management command for E1000 devices. When used on devices 1154 with SPI support you can reprogram the EEPROM from U-Boot. 1155 1156 CONFIG_EEPRO100 1157 Support for Intel 82557/82559/82559ER chips. 1158 Optional CONFIG_EEPRO100_SROM_WRITE enables EEPROM 1159 write routine for first time initialisation. 1160 1161 CONFIG_TULIP 1162 Support for Digital 2114x chips. 1163 Optional CONFIG_TULIP_SELECT_MEDIA for board specific 1164 modem chip initialisation (KS8761/QS6611). 1165 1166 CONFIG_NATSEMI 1167 Support for National dp83815 chips. 1168 1169 CONFIG_NS8382X 1170 Support for National dp8382[01] gigabit chips. 1171 1172- NETWORK Support (other): 1173 1174 CONFIG_DRIVER_AT91EMAC 1175 Support for AT91RM9200 EMAC. 1176 1177 CONFIG_RMII 1178 Define this to use reduced MII inteface 1179 1180 CONFIG_DRIVER_AT91EMAC_QUIET 1181 If this defined, the driver is quiet. 1182 The driver doen't show link status messages. 1183 1184 CONFIG_CALXEDA_XGMAC 1185 Support for the Calxeda XGMAC device 1186 1187 CONFIG_LAN91C96 1188 Support for SMSC's LAN91C96 chips. 1189 1190 CONFIG_LAN91C96_USE_32_BIT 1191 Define this to enable 32 bit addressing 1192 1193 CONFIG_SMC91111 1194 Support for SMSC's LAN91C111 chip 1195 1196 CONFIG_SMC91111_BASE 1197 Define this to hold the physical address 1198 of the device (I/O space) 1199 1200 CONFIG_SMC_USE_32_BIT 1201 Define this if data bus is 32 bits 1202 1203 CONFIG_SMC_USE_IOFUNCS 1204 Define this to use i/o functions instead of macros 1205 (some hardware wont work with macros) 1206 1207 CONFIG_DRIVER_TI_EMAC 1208 Support for davinci emac 1209 1210 CONFIG_SYS_DAVINCI_EMAC_PHY_COUNT 1211 Define this if you have more then 3 PHYs. 1212 1213 CONFIG_FTGMAC100 1214 Support for Faraday's FTGMAC100 Gigabit SoC Ethernet 1215 1216 CONFIG_FTGMAC100_EGIGA 1217 Define this to use GE link update with gigabit PHY. 1218 Define this if FTGMAC100 is connected to gigabit PHY. 1219 If your system has 10/100 PHY only, it might not occur 1220 wrong behavior. Because PHY usually return timeout or 1221 useless data when polling gigabit status and gigabit 1222 control registers. This behavior won't affect the 1223 correctnessof 10/100 link speed update. 1224 1225 CONFIG_SMC911X 1226 Support for SMSC's LAN911x and LAN921x chips 1227 1228 CONFIG_SMC911X_BASE 1229 Define this to hold the physical address 1230 of the device (I/O space) 1231 1232 CONFIG_SMC911X_32_BIT 1233 Define this if data bus is 32 bits 1234 1235 CONFIG_SMC911X_16_BIT 1236 Define this if data bus is 16 bits. If your processor 1237 automatically converts one 32 bit word to two 16 bit 1238 words you may also try CONFIG_SMC911X_32_BIT. 1239 1240 CONFIG_SH_ETHER 1241 Support for Renesas on-chip Ethernet controller 1242 1243 CONFIG_SH_ETHER_USE_PORT 1244 Define the number of ports to be used 1245 1246 CONFIG_SH_ETHER_PHY_ADDR 1247 Define the ETH PHY's address 1248 1249 CONFIG_SH_ETHER_CACHE_WRITEBACK 1250 If this option is set, the driver enables cache flush. 1251 1252- PWM Support: 1253 CONFIG_PWM_IMX 1254 Support for PWM module on the imx6. 1255 1256- TPM Support: 1257 CONFIG_TPM 1258 Support TPM devices. 1259 1260 CONFIG_TPM_TIS_INFINEON 1261 Support for Infineon i2c bus TPM devices. Only one device 1262 per system is supported at this time. 1263 1264 CONFIG_TPM_TIS_I2C_BURST_LIMITATION 1265 Define the burst count bytes upper limit 1266 1267 CONFIG_TPM_ST33ZP24 1268 Support for STMicroelectronics TPM devices. Requires DM_TPM support. 1269 1270 CONFIG_TPM_ST33ZP24_I2C 1271 Support for STMicroelectronics ST33ZP24 I2C devices. 1272 Requires TPM_ST33ZP24 and I2C. 1273 1274 CONFIG_TPM_ST33ZP24_SPI 1275 Support for STMicroelectronics ST33ZP24 SPI devices. 1276 Requires TPM_ST33ZP24 and SPI. 1277 1278 CONFIG_TPM_ATMEL_TWI 1279 Support for Atmel TWI TPM device. Requires I2C support. 1280 1281 CONFIG_TPM_TIS_LPC 1282 Support for generic parallel port TPM devices. Only one device 1283 per system is supported at this time. 1284 1285 CONFIG_TPM_TIS_BASE_ADDRESS 1286 Base address where the generic TPM device is mapped 1287 to. Contemporary x86 systems usually map it at 1288 0xfed40000. 1289 1290 CONFIG_CMD_TPM 1291 Add tpm monitor functions. 1292 Requires CONFIG_TPM. If CONFIG_TPM_AUTH_SESSIONS is set, also 1293 provides monitor access to authorized functions. 1294 1295 CONFIG_TPM 1296 Define this to enable the TPM support library which provides 1297 functional interfaces to some TPM commands. 1298 Requires support for a TPM device. 1299 1300 CONFIG_TPM_AUTH_SESSIONS 1301 Define this to enable authorized functions in the TPM library. 1302 Requires CONFIG_TPM and CONFIG_SHA1. 1303 1304- USB Support: 1305 At the moment only the UHCI host controller is 1306 supported (PIP405, MIP405, MPC5200); define 1307 CONFIG_USB_UHCI to enable it. 1308 define CONFIG_USB_KEYBOARD to enable the USB Keyboard 1309 and define CONFIG_USB_STORAGE to enable the USB 1310 storage devices. 1311 Note: 1312 Supported are USB Keyboards and USB Floppy drives 1313 (TEAC FD-05PUB). 1314 MPC5200 USB requires additional defines: 1315 CONFIG_USB_CLOCK 1316 for 528 MHz Clock: 0x0001bbbb 1317 CONFIG_PSC3_USB 1318 for USB on PSC3 1319 CONFIG_USB_CONFIG 1320 for differential drivers: 0x00001000 1321 for single ended drivers: 0x00005000 1322 for differential drivers on PSC3: 0x00000100 1323 for single ended drivers on PSC3: 0x00004100 1324 CONFIG_SYS_USB_EVENT_POLL 1325 May be defined to allow interrupt polling 1326 instead of using asynchronous interrupts 1327 1328 CONFIG_USB_EHCI_TXFIFO_THRESH enables setting of the 1329 txfilltuning field in the EHCI controller on reset. 1330 1331 CONFIG_USB_DWC2_REG_ADDR the physical CPU address of the DWC2 1332 HW module registers. 1333 1334- USB Device: 1335 Define the below if you wish to use the USB console. 1336 Once firmware is rebuilt from a serial console issue the 1337 command "setenv stdin usbtty; setenv stdout usbtty" and 1338 attach your USB cable. The Unix command "dmesg" should print 1339 it has found a new device. The environment variable usbtty 1340 can be set to gserial or cdc_acm to enable your device to 1341 appear to a USB host as a Linux gserial device or a 1342 Common Device Class Abstract Control Model serial device. 1343 If you select usbtty = gserial you should be able to enumerate 1344 a Linux host by 1345 # modprobe usbserial vendor=0xVendorID product=0xProductID 1346 else if using cdc_acm, simply setting the environment 1347 variable usbtty to be cdc_acm should suffice. The following 1348 might be defined in YourBoardName.h 1349 1350 CONFIG_USB_DEVICE 1351 Define this to build a UDC device 1352 1353 CONFIG_USB_TTY 1354 Define this to have a tty type of device available to 1355 talk to the UDC device 1356 1357 CONFIG_USBD_HS 1358 Define this to enable the high speed support for usb 1359 device and usbtty. If this feature is enabled, a routine 1360 int is_usbd_high_speed(void) 1361 also needs to be defined by the driver to dynamically poll 1362 whether the enumeration has succeded at high speed or full 1363 speed. 1364 1365 CONFIG_SYS_CONSOLE_IS_IN_ENV 1366 Define this if you want stdin, stdout &/or stderr to 1367 be set to usbtty. 1368 1369 mpc8xx: 1370 CONFIG_SYS_USB_EXTC_CLK 0xBLAH 1371 Derive USB clock from external clock "blah" 1372 - CONFIG_SYS_USB_EXTC_CLK 0x02 1373 1374 If you have a USB-IF assigned VendorID then you may wish to 1375 define your own vendor specific values either in BoardName.h 1376 or directly in usbd_vendor_info.h. If you don't define 1377 CONFIG_USBD_MANUFACTURER, CONFIG_USBD_PRODUCT_NAME, 1378 CONFIG_USBD_VENDORID and CONFIG_USBD_PRODUCTID, then U-Boot 1379 should pretend to be a Linux device to it's target host. 1380 1381 CONFIG_USBD_MANUFACTURER 1382 Define this string as the name of your company for 1383 - CONFIG_USBD_MANUFACTURER "my company" 1384 1385 CONFIG_USBD_PRODUCT_NAME 1386 Define this string as the name of your product 1387 - CONFIG_USBD_PRODUCT_NAME "acme usb device" 1388 1389 CONFIG_USBD_VENDORID 1390 Define this as your assigned Vendor ID from the USB 1391 Implementors Forum. This *must* be a genuine Vendor ID 1392 to avoid polluting the USB namespace. 1393 - CONFIG_USBD_VENDORID 0xFFFF 1394 1395 CONFIG_USBD_PRODUCTID 1396 Define this as the unique Product ID 1397 for your device 1398 - CONFIG_USBD_PRODUCTID 0xFFFF 1399 1400- ULPI Layer Support: 1401 The ULPI (UTMI Low Pin (count) Interface) PHYs are supported via 1402 the generic ULPI layer. The generic layer accesses the ULPI PHY 1403 via the platform viewport, so you need both the genric layer and 1404 the viewport enabled. Currently only Chipidea/ARC based 1405 viewport is supported. 1406 To enable the ULPI layer support, define CONFIG_USB_ULPI and 1407 CONFIG_USB_ULPI_VIEWPORT in your board configuration file. 1408 If your ULPI phy needs a different reference clock than the 1409 standard 24 MHz then you have to define CONFIG_ULPI_REF_CLK to 1410 the appropriate value in Hz. 1411 1412- MMC Support: 1413 The MMC controller on the Intel PXA is supported. To 1414 enable this define CONFIG_MMC. The MMC can be 1415 accessed from the boot prompt by mapping the device 1416 to physical memory similar to flash. Command line is 1417 enabled with CONFIG_CMD_MMC. The MMC driver also works with 1418 the FAT fs. This is enabled with CONFIG_CMD_FAT. 1419 1420 CONFIG_SH_MMCIF 1421 Support for Renesas on-chip MMCIF controller 1422 1423 CONFIG_SH_MMCIF_ADDR 1424 Define the base address of MMCIF registers 1425 1426 CONFIG_SH_MMCIF_CLK 1427 Define the clock frequency for MMCIF 1428 1429 CONFIG_SUPPORT_EMMC_BOOT 1430 Enable some additional features of the eMMC boot partitions. 1431 1432 CONFIG_SUPPORT_EMMC_RPMB 1433 Enable the commands for reading, writing and programming the 1434 key for the Replay Protection Memory Block partition in eMMC. 1435 1436- USB Device Firmware Update (DFU) class support: 1437 CONFIG_USB_FUNCTION_DFU 1438 This enables the USB portion of the DFU USB class 1439 1440 CONFIG_CMD_DFU 1441 This enables the command "dfu" which is used to have 1442 U-Boot create a DFU class device via USB. This command 1443 requires that the "dfu_alt_info" environment variable be 1444 set and define the alt settings to expose to the host. 1445 1446 CONFIG_DFU_MMC 1447 This enables support for exposing (e)MMC devices via DFU. 1448 1449 CONFIG_DFU_NAND 1450 This enables support for exposing NAND devices via DFU. 1451 1452 CONFIG_DFU_RAM 1453 This enables support for exposing RAM via DFU. 1454 Note: DFU spec refer to non-volatile memory usage, but 1455 allow usages beyond the scope of spec - here RAM usage, 1456 one that would help mostly the developer. 1457 1458 CONFIG_SYS_DFU_DATA_BUF_SIZE 1459 Dfu transfer uses a buffer before writing data to the 1460 raw storage device. Make the size (in bytes) of this buffer 1461 configurable. The size of this buffer is also configurable 1462 through the "dfu_bufsiz" environment variable. 1463 1464 CONFIG_SYS_DFU_MAX_FILE_SIZE 1465 When updating files rather than the raw storage device, 1466 we use a static buffer to copy the file into and then write 1467 the buffer once we've been given the whole file. Define 1468 this to the maximum filesize (in bytes) for the buffer. 1469 Default is 4 MiB if undefined. 1470 1471 DFU_DEFAULT_POLL_TIMEOUT 1472 Poll timeout [ms], is the timeout a device can send to the 1473 host. The host must wait for this timeout before sending 1474 a subsequent DFU_GET_STATUS request to the device. 1475 1476 DFU_MANIFEST_POLL_TIMEOUT 1477 Poll timeout [ms], which the device sends to the host when 1478 entering dfuMANIFEST state. Host waits this timeout, before 1479 sending again an USB request to the device. 1480 1481- USB Device Android Fastboot support: 1482 CONFIG_USB_FUNCTION_FASTBOOT 1483 This enables the USB part of the fastboot gadget 1484 1485 CONFIG_CMD_FASTBOOT 1486 This enables the command "fastboot" which enables the Android 1487 fastboot mode for the platform's USB device. Fastboot is a USB 1488 protocol for downloading images, flashing and device control 1489 used on Android devices. 1490 See doc/README.android-fastboot for more information. 1491 1492 CONFIG_ANDROID_BOOT_IMAGE 1493 This enables support for booting images which use the Android 1494 image format header. 1495 1496 CONFIG_FASTBOOT_BUF_ADDR 1497 The fastboot protocol requires a large memory buffer for 1498 downloads. Define this to the starting RAM address to use for 1499 downloaded images. 1500 1501 CONFIG_FASTBOOT_BUF_SIZE 1502 The fastboot protocol requires a large memory buffer for 1503 downloads. This buffer should be as large as possible for a 1504 platform. Define this to the size available RAM for fastboot. 1505 1506 CONFIG_FASTBOOT_FLASH 1507 The fastboot protocol includes a "flash" command for writing 1508 the downloaded image to a non-volatile storage device. Define 1509 this to enable the "fastboot flash" command. 1510 1511 CONFIG_FASTBOOT_FLASH_MMC_DEV 1512 The fastboot "flash" command requires additional information 1513 regarding the non-volatile storage device. Define this to 1514 the eMMC device that fastboot should use to store the image. 1515 1516 CONFIG_FASTBOOT_GPT_NAME 1517 The fastboot "flash" command supports writing the downloaded 1518 image to the Protective MBR and the Primary GUID Partition 1519 Table. (Additionally, this downloaded image is post-processed 1520 to generate and write the Backup GUID Partition Table.) 1521 This occurs when the specified "partition name" on the 1522 "fastboot flash" command line matches this value. 1523 The default is "gpt" if undefined. 1524 1525 CONFIG_FASTBOOT_MBR_NAME 1526 The fastboot "flash" command supports writing the downloaded 1527 image to DOS MBR. 1528 This occurs when the "partition name" specified on the 1529 "fastboot flash" command line matches this value. 1530 If not defined the default value "mbr" is used. 1531 1532- Journaling Flash filesystem support: 1533 CONFIG_JFFS2_NAND 1534 Define these for a default partition on a NAND device 1535 1536 CONFIG_SYS_JFFS2_FIRST_SECTOR, 1537 CONFIG_SYS_JFFS2_FIRST_BANK, CONFIG_SYS_JFFS2_NUM_BANKS 1538 Define these for a default partition on a NOR device 1539 1540- FAT(File Allocation Table) filesystem write function support: 1541 CONFIG_FAT_WRITE 1542 1543 Define this to enable support for saving memory data as a 1544 file in FAT formatted partition. 1545 1546 This will also enable the command "fatwrite" enabling the 1547 user to write files to FAT. 1548 1549- CBFS (Coreboot Filesystem) support: 1550 CONFIG_CMD_CBFS 1551 1552 Define this to enable support for reading from a Coreboot 1553 filesystem. Available commands are cbfsinit, cbfsinfo, cbfsls 1554 and cbfsload. 1555 1556- FAT(File Allocation Table) filesystem cluster size: 1557 CONFIG_FS_FAT_MAX_CLUSTSIZE 1558 1559 Define the max cluster size for fat operations else 1560 a default value of 65536 will be defined. 1561 1562- Keyboard Support: 1563 See Kconfig help for available keyboard drivers. 1564 1565 CONFIG_KEYBOARD 1566 1567 Define this to enable a custom keyboard support. 1568 This simply calls drv_keyboard_init() which must be 1569 defined in your board-specific files. This option is deprecated 1570 and is only used by novena. For new boards, use driver model 1571 instead. 1572 1573- Video support: 1574 CONFIG_FSL_DIU_FB 1575 Enable the Freescale DIU video driver. Reference boards for 1576 SOCs that have a DIU should define this macro to enable DIU 1577 support, and should also define these other macros: 1578 1579 CONFIG_SYS_DIU_ADDR 1580 CONFIG_VIDEO 1581 CONFIG_CFB_CONSOLE 1582 CONFIG_VIDEO_SW_CURSOR 1583 CONFIG_VGA_AS_SINGLE_DEVICE 1584 CONFIG_VIDEO_LOGO 1585 CONFIG_VIDEO_BMP_LOGO 1586 1587 The DIU driver will look for the 'video-mode' environment 1588 variable, and if defined, enable the DIU as a console during 1589 boot. See the documentation file doc/README.video for a 1590 description of this variable. 1591 1592- LCD Support: CONFIG_LCD 1593 1594 Define this to enable LCD support (for output to LCD 1595 display); also select one of the supported displays 1596 by defining one of these: 1597 1598 CONFIG_ATMEL_LCD: 1599 1600 HITACHI TX09D70VM1CCA, 3.5", 240x320. 1601 1602 CONFIG_NEC_NL6448AC33: 1603 1604 NEC NL6448AC33-18. Active, color, single scan. 1605 1606 CONFIG_NEC_NL6448BC20 1607 1608 NEC NL6448BC20-08. 6.5", 640x480. 1609 Active, color, single scan. 1610 1611 CONFIG_NEC_NL6448BC33_54 1612 1613 NEC NL6448BC33-54. 10.4", 640x480. 1614 Active, color, single scan. 1615 1616 CONFIG_SHARP_16x9 1617 1618 Sharp 320x240. Active, color, single scan. 1619 It isn't 16x9, and I am not sure what it is. 1620 1621 CONFIG_SHARP_LQ64D341 1622 1623 Sharp LQ64D341 display, 640x480. 1624 Active, color, single scan. 1625 1626 CONFIG_HLD1045 1627 1628 HLD1045 display, 640x480. 1629 Active, color, single scan. 1630 1631 CONFIG_OPTREX_BW 1632 1633 Optrex CBL50840-2 NF-FW 99 22 M5 1634 or 1635 Hitachi LMG6912RPFC-00T 1636 or 1637 Hitachi SP14Q002 1638 1639 320x240. Black & white. 1640 1641 CONFIG_LCD_ALIGNMENT 1642 1643 Normally the LCD is page-aligned (typically 4KB). If this is 1644 defined then the LCD will be aligned to this value instead. 1645 For ARM it is sometimes useful to use MMU_SECTION_SIZE 1646 here, since it is cheaper to change data cache settings on 1647 a per-section basis. 1648 1649 1650 CONFIG_LCD_ROTATION 1651 1652 Sometimes, for example if the display is mounted in portrait 1653 mode or even if it's mounted landscape but rotated by 180degree, 1654 we need to rotate our content of the display relative to the 1655 framebuffer, so that user can read the messages which are 1656 printed out. 1657 Once CONFIG_LCD_ROTATION is defined, the lcd_console will be 1658 initialized with a given rotation from "vl_rot" out of 1659 "vidinfo_t" which is provided by the board specific code. 1660 The value for vl_rot is coded as following (matching to 1661 fbcon=rotate:<n> linux-kernel commandline): 1662 0 = no rotation respectively 0 degree 1663 1 = 90 degree rotation 1664 2 = 180 degree rotation 1665 3 = 270 degree rotation 1666 1667 If CONFIG_LCD_ROTATION is not defined, the console will be 1668 initialized with 0degree rotation. 1669 1670 CONFIG_LCD_BMP_RLE8 1671 1672 Support drawing of RLE8-compressed bitmaps on the LCD. 1673 1674 CONFIG_I2C_EDID 1675 1676 Enables an 'i2c edid' command which can read EDID 1677 information over I2C from an attached LCD display. 1678 1679- Splash Screen Support: CONFIG_SPLASH_SCREEN 1680 1681 If this option is set, the environment is checked for 1682 a variable "splashimage". If found, the usual display 1683 of logo, copyright and system information on the LCD 1684 is suppressed and the BMP image at the address 1685 specified in "splashimage" is loaded instead. The 1686 console is redirected to the "nulldev", too. This 1687 allows for a "silent" boot where a splash screen is 1688 loaded very quickly after power-on. 1689 1690 CONFIG_SPLASHIMAGE_GUARD 1691 1692 If this option is set, then U-Boot will prevent the environment 1693 variable "splashimage" from being set to a problematic address 1694 (see doc/README.displaying-bmps). 1695 This option is useful for targets where, due to alignment 1696 restrictions, an improperly aligned BMP image will cause a data 1697 abort. If you think you will not have problems with unaligned 1698 accesses (for example because your toolchain prevents them) 1699 there is no need to set this option. 1700 1701 CONFIG_SPLASH_SCREEN_ALIGN 1702 1703 If this option is set the splash image can be freely positioned 1704 on the screen. Environment variable "splashpos" specifies the 1705 position as "x,y". If a positive number is given it is used as 1706 number of pixel from left/top. If a negative number is given it 1707 is used as number of pixel from right/bottom. You can also 1708 specify 'm' for centering the image. 1709 1710 Example: 1711 setenv splashpos m,m 1712 => image at center of screen 1713 1714 setenv splashpos 30,20 1715 => image at x = 30 and y = 20 1716 1717 setenv splashpos -10,m 1718 => vertically centered image 1719 at x = dspWidth - bmpWidth - 9 1720 1721- Gzip compressed BMP image support: CONFIG_VIDEO_BMP_GZIP 1722 1723 If this option is set, additionally to standard BMP 1724 images, gzipped BMP images can be displayed via the 1725 splashscreen support or the bmp command. 1726 1727- Run length encoded BMP image (RLE8) support: CONFIG_VIDEO_BMP_RLE8 1728 1729 If this option is set, 8-bit RLE compressed BMP images 1730 can be displayed via the splashscreen support or the 1731 bmp command. 1732 1733- Compression support: 1734 CONFIG_GZIP 1735 1736 Enabled by default to support gzip compressed images. 1737 1738 CONFIG_BZIP2 1739 1740 If this option is set, support for bzip2 compressed 1741 images is included. If not, only uncompressed and gzip 1742 compressed images are supported. 1743 1744 NOTE: the bzip2 algorithm requires a lot of RAM, so 1745 the malloc area (as defined by CONFIG_SYS_MALLOC_LEN) should 1746 be at least 4MB. 1747 1748 CONFIG_LZMA 1749 1750 If this option is set, support for lzma compressed 1751 images is included. 1752 1753 Note: The LZMA algorithm adds between 2 and 4KB of code and it 1754 requires an amount of dynamic memory that is given by the 1755 formula: 1756 1757 (1846 + 768 << (lc + lp)) * sizeof(uint16) 1758 1759 Where lc and lp stand for, respectively, Literal context bits 1760 and Literal pos bits. 1761 1762 This value is upper-bounded by 14MB in the worst case. Anyway, 1763 for a ~4MB large kernel image, we have lc=3 and lp=0 for a 1764 total amount of (1846 + 768 << (3 + 0)) * 2 = ~41KB... that is 1765 a very small buffer. 1766 1767 Use the lzmainfo tool to determinate the lc and lp values and 1768 then calculate the amount of needed dynamic memory (ensuring 1769 the appropriate CONFIG_SYS_MALLOC_LEN value). 1770 1771 CONFIG_LZO 1772 1773 If this option is set, support for LZO compressed images 1774 is included. 1775 1776- MII/PHY support: 1777 CONFIG_PHY_ADDR 1778 1779 The address of PHY on MII bus. 1780 1781 CONFIG_PHY_CLOCK_FREQ (ppc4xx) 1782 1783 The clock frequency of the MII bus 1784 1785 CONFIG_PHY_GIGE 1786 1787 If this option is set, support for speed/duplex 1788 detection of gigabit PHY is included. 1789 1790 CONFIG_PHY_RESET_DELAY 1791 1792 Some PHY like Intel LXT971A need extra delay after 1793 reset before any MII register access is possible. 1794 For such PHY, set this option to the usec delay 1795 required. (minimum 300usec for LXT971A) 1796 1797 CONFIG_PHY_CMD_DELAY (ppc4xx) 1798 1799 Some PHY like Intel LXT971A need extra delay after 1800 command issued before MII status register can be read 1801 1802- IP address: 1803 CONFIG_IPADDR 1804 1805 Define a default value for the IP address to use for 1806 the default Ethernet interface, in case this is not 1807 determined through e.g. bootp. 1808 (Environment variable "ipaddr") 1809 1810- Server IP address: 1811 CONFIG_SERVERIP 1812 1813 Defines a default value for the IP address of a TFTP 1814 server to contact when using the "tftboot" command. 1815 (Environment variable "serverip") 1816 1817 CONFIG_KEEP_SERVERADDR 1818 1819 Keeps the server's MAC address, in the env 'serveraddr' 1820 for passing to bootargs (like Linux's netconsole option) 1821 1822- Gateway IP address: 1823 CONFIG_GATEWAYIP 1824 1825 Defines a default value for the IP address of the 1826 default router where packets to other networks are 1827 sent to. 1828 (Environment variable "gatewayip") 1829 1830- Subnet mask: 1831 CONFIG_NETMASK 1832 1833 Defines a default value for the subnet mask (or 1834 routing prefix) which is used to determine if an IP 1835 address belongs to the local subnet or needs to be 1836 forwarded through a router. 1837 (Environment variable "netmask") 1838 1839- Multicast TFTP Mode: 1840 CONFIG_MCAST_TFTP 1841 1842 Defines whether you want to support multicast TFTP as per 1843 rfc-2090; for example to work with atftp. Lets lots of targets 1844 tftp down the same boot image concurrently. Note: the Ethernet 1845 driver in use must provide a function: mcast() to join/leave a 1846 multicast group. 1847 1848- BOOTP Recovery Mode: 1849 CONFIG_BOOTP_RANDOM_DELAY 1850 1851 If you have many targets in a network that try to 1852 boot using BOOTP, you may want to avoid that all 1853 systems send out BOOTP requests at precisely the same 1854 moment (which would happen for instance at recovery 1855 from a power failure, when all systems will try to 1856 boot, thus flooding the BOOTP server. Defining 1857 CONFIG_BOOTP_RANDOM_DELAY causes a random delay to be 1858 inserted before sending out BOOTP requests. The 1859 following delays are inserted then: 1860 1861 1st BOOTP request: delay 0 ... 1 sec 1862 2nd BOOTP request: delay 0 ... 2 sec 1863 3rd BOOTP request: delay 0 ... 4 sec 1864 4th and following 1865 BOOTP requests: delay 0 ... 8 sec 1866 1867 CONFIG_BOOTP_ID_CACHE_SIZE 1868 1869 BOOTP packets are uniquely identified using a 32-bit ID. The 1870 server will copy the ID from client requests to responses and 1871 U-Boot will use this to determine if it is the destination of 1872 an incoming response. Some servers will check that addresses 1873 aren't in use before handing them out (usually using an ARP 1874 ping) and therefore take up to a few hundred milliseconds to 1875 respond. Network congestion may also influence the time it 1876 takes for a response to make it back to the client. If that 1877 time is too long, U-Boot will retransmit requests. In order 1878 to allow earlier responses to still be accepted after these 1879 retransmissions, U-Boot's BOOTP client keeps a small cache of 1880 IDs. The CONFIG_BOOTP_ID_CACHE_SIZE controls the size of this 1881 cache. The default is to keep IDs for up to four outstanding 1882 requests. Increasing this will allow U-Boot to accept offers 1883 from a BOOTP client in networks with unusually high latency. 1884 1885- DHCP Advanced Options: 1886 You can fine tune the DHCP functionality by defining 1887 CONFIG_BOOTP_* symbols: 1888 1889 CONFIG_BOOTP_SUBNETMASK 1890 CONFIG_BOOTP_GATEWAY 1891 CONFIG_BOOTP_HOSTNAME 1892 CONFIG_BOOTP_NISDOMAIN 1893 CONFIG_BOOTP_BOOTPATH 1894 CONFIG_BOOTP_BOOTFILESIZE 1895 CONFIG_BOOTP_DNS 1896 CONFIG_BOOTP_DNS2 1897 CONFIG_BOOTP_SEND_HOSTNAME 1898 CONFIG_BOOTP_NTPSERVER 1899 CONFIG_BOOTP_TIMEOFFSET 1900 CONFIG_BOOTP_VENDOREX 1901 CONFIG_BOOTP_MAY_FAIL 1902 1903 CONFIG_BOOTP_SERVERIP - TFTP server will be the serverip 1904 environment variable, not the BOOTP server. 1905 1906 CONFIG_BOOTP_MAY_FAIL - If the DHCP server is not found 1907 after the configured retry count, the call will fail 1908 instead of starting over. This can be used to fail over 1909 to Link-local IP address configuration if the DHCP server 1910 is not available. 1911 1912 CONFIG_BOOTP_DNS2 - If a DHCP client requests the DNS 1913 serverip from a DHCP server, it is possible that more 1914 than one DNS serverip is offered to the client. 1915 If CONFIG_BOOTP_DNS2 is enabled, the secondary DNS 1916 serverip will be stored in the additional environment 1917 variable "dnsip2". The first DNS serverip is always 1918 stored in the variable "dnsip", when CONFIG_BOOTP_DNS 1919 is defined. 1920 1921 CONFIG_BOOTP_SEND_HOSTNAME - Some DHCP servers are capable 1922 to do a dynamic update of a DNS server. To do this, they 1923 need the hostname of the DHCP requester. 1924 If CONFIG_BOOTP_SEND_HOSTNAME is defined, the content 1925 of the "hostname" environment variable is passed as 1926 option 12 to the DHCP server. 1927 1928 CONFIG_BOOTP_DHCP_REQUEST_DELAY 1929 1930 A 32bit value in microseconds for a delay between 1931 receiving a "DHCP Offer" and sending the "DHCP Request". 1932 This fixes a problem with certain DHCP servers that don't 1933 respond 100% of the time to a "DHCP request". E.g. On an 1934 AT91RM9200 processor running at 180MHz, this delay needed 1935 to be *at least* 15,000 usec before a Windows Server 2003 1936 DHCP server would reply 100% of the time. I recommend at 1937 least 50,000 usec to be safe. The alternative is to hope 1938 that one of the retries will be successful but note that 1939 the DHCP timeout and retry process takes a longer than 1940 this delay. 1941 1942 - Link-local IP address negotiation: 1943 Negotiate with other link-local clients on the local network 1944 for an address that doesn't require explicit configuration. 1945 This is especially useful if a DHCP server cannot be guaranteed 1946 to exist in all environments that the device must operate. 1947 1948 See doc/README.link-local for more information. 1949 1950 - CDP Options: 1951 CONFIG_CDP_DEVICE_ID 1952 1953 The device id used in CDP trigger frames. 1954 1955 CONFIG_CDP_DEVICE_ID_PREFIX 1956 1957 A two character string which is prefixed to the MAC address 1958 of the device. 1959 1960 CONFIG_CDP_PORT_ID 1961 1962 A printf format string which contains the ascii name of 1963 the port. Normally is set to "eth%d" which sets 1964 eth0 for the first Ethernet, eth1 for the second etc. 1965 1966 CONFIG_CDP_CAPABILITIES 1967 1968 A 32bit integer which indicates the device capabilities; 1969 0x00000010 for a normal host which does not forwards. 1970 1971 CONFIG_CDP_VERSION 1972 1973 An ascii string containing the version of the software. 1974 1975 CONFIG_CDP_PLATFORM 1976 1977 An ascii string containing the name of the platform. 1978 1979 CONFIG_CDP_TRIGGER 1980 1981 A 32bit integer sent on the trigger. 1982 1983 CONFIG_CDP_POWER_CONSUMPTION 1984 1985 A 16bit integer containing the power consumption of the 1986 device in .1 of milliwatts. 1987 1988 CONFIG_CDP_APPLIANCE_VLAN_TYPE 1989 1990 A byte containing the id of the VLAN. 1991 1992- Status LED: CONFIG_LED_STATUS 1993 1994 Several configurations allow to display the current 1995 status using a LED. For instance, the LED will blink 1996 fast while running U-Boot code, stop blinking as 1997 soon as a reply to a BOOTP request was received, and 1998 start blinking slow once the Linux kernel is running 1999 (supported by a status LED driver in the Linux 2000 kernel). Defining CONFIG_LED_STATUS enables this 2001 feature in U-Boot. 2002 2003 Additional options: 2004 2005 CONFIG_LED_STATUS_GPIO 2006 The status LED can be connected to a GPIO pin. 2007 In such cases, the gpio_led driver can be used as a 2008 status LED backend implementation. Define CONFIG_LED_STATUS_GPIO 2009 to include the gpio_led driver in the U-Boot binary. 2010 2011 CONFIG_GPIO_LED_INVERTED_TABLE 2012 Some GPIO connected LEDs may have inverted polarity in which 2013 case the GPIO high value corresponds to LED off state and 2014 GPIO low value corresponds to LED on state. 2015 In such cases CONFIG_GPIO_LED_INVERTED_TABLE may be defined 2016 with a list of GPIO LEDs that have inverted polarity. 2017 2018- CAN Support: CONFIG_CAN_DRIVER 2019 2020 Defining CONFIG_CAN_DRIVER enables CAN driver support 2021 on those systems that support this (optional) 2022 feature, like the TQM8xxL modules. 2023 2024- I2C Support: CONFIG_SYS_I2C 2025 2026 This enable the NEW i2c subsystem, and will allow you to use 2027 i2c commands at the u-boot command line (as long as you set 2028 CONFIG_CMD_I2C in CONFIG_COMMANDS) and communicate with i2c 2029 based realtime clock chips or other i2c devices. See 2030 common/cmd_i2c.c for a description of the command line 2031 interface. 2032 2033 ported i2c driver to the new framework: 2034 - drivers/i2c/soft_i2c.c: 2035 - activate first bus with CONFIG_SYS_I2C_SOFT define 2036 CONFIG_SYS_I2C_SOFT_SPEED and CONFIG_SYS_I2C_SOFT_SLAVE 2037 for defining speed and slave address 2038 - activate second bus with I2C_SOFT_DECLARATIONS2 define 2039 CONFIG_SYS_I2C_SOFT_SPEED_2 and CONFIG_SYS_I2C_SOFT_SLAVE_2 2040 for defining speed and slave address 2041 - activate third bus with I2C_SOFT_DECLARATIONS3 define 2042 CONFIG_SYS_I2C_SOFT_SPEED_3 and CONFIG_SYS_I2C_SOFT_SLAVE_3 2043 for defining speed and slave address 2044 - activate fourth bus with I2C_SOFT_DECLARATIONS4 define 2045 CONFIG_SYS_I2C_SOFT_SPEED_4 and CONFIG_SYS_I2C_SOFT_SLAVE_4 2046 for defining speed and slave address 2047 2048 - drivers/i2c/fsl_i2c.c: 2049 - activate i2c driver with CONFIG_SYS_I2C_FSL 2050 define CONFIG_SYS_FSL_I2C_OFFSET for setting the register 2051 offset CONFIG_SYS_FSL_I2C_SPEED for the i2c speed and 2052 CONFIG_SYS_FSL_I2C_SLAVE for the slave addr of the first 2053 bus. 2054 - If your board supports a second fsl i2c bus, define 2055 CONFIG_SYS_FSL_I2C2_OFFSET for the register offset 2056 CONFIG_SYS_FSL_I2C2_SPEED for the speed and 2057 CONFIG_SYS_FSL_I2C2_SLAVE for the slave address of the 2058 second bus. 2059 2060 - drivers/i2c/tegra_i2c.c: 2061 - activate this driver with CONFIG_SYS_I2C_TEGRA 2062 - This driver adds 4 i2c buses with a fix speed from 2063 100000 and the slave addr 0! 2064 2065 - drivers/i2c/ppc4xx_i2c.c 2066 - activate this driver with CONFIG_SYS_I2C_PPC4XX 2067 - CONFIG_SYS_I2C_PPC4XX_CH0 activate hardware channel 0 2068 - CONFIG_SYS_I2C_PPC4XX_CH1 activate hardware channel 1 2069 2070 - drivers/i2c/i2c_mxc.c 2071 - activate this driver with CONFIG_SYS_I2C_MXC 2072 - enable bus 1 with CONFIG_SYS_I2C_MXC_I2C1 2073 - enable bus 2 with CONFIG_SYS_I2C_MXC_I2C2 2074 - enable bus 3 with CONFIG_SYS_I2C_MXC_I2C3 2075 - enable bus 4 with CONFIG_SYS_I2C_MXC_I2C4 2076 - define speed for bus 1 with CONFIG_SYS_MXC_I2C1_SPEED 2077 - define slave for bus 1 with CONFIG_SYS_MXC_I2C1_SLAVE 2078 - define speed for bus 2 with CONFIG_SYS_MXC_I2C2_SPEED 2079 - define slave for bus 2 with CONFIG_SYS_MXC_I2C2_SLAVE 2080 - define speed for bus 3 with CONFIG_SYS_MXC_I2C3_SPEED 2081 - define slave for bus 3 with CONFIG_SYS_MXC_I2C3_SLAVE 2082 - define speed for bus 4 with CONFIG_SYS_MXC_I2C4_SPEED 2083 - define slave for bus 4 with CONFIG_SYS_MXC_I2C4_SLAVE 2084 If those defines are not set, default value is 100000 2085 for speed, and 0 for slave. 2086 2087 - drivers/i2c/rcar_i2c.c: 2088 - activate this driver with CONFIG_SYS_I2C_RCAR 2089 - This driver adds 4 i2c buses 2090 2091 - CONFIG_SYS_RCAR_I2C0_BASE for setting the register channel 0 2092 - CONFIG_SYS_RCAR_I2C0_SPEED for for the speed channel 0 2093 - CONFIG_SYS_RCAR_I2C1_BASE for setting the register channel 1 2094 - CONFIG_SYS_RCAR_I2C1_SPEED for for the speed channel 1 2095 - CONFIG_SYS_RCAR_I2C2_BASE for setting the register channel 2 2096 - CONFIG_SYS_RCAR_I2C2_SPEED for for the speed channel 2 2097 - CONFIG_SYS_RCAR_I2C3_BASE for setting the register channel 3 2098 - CONFIG_SYS_RCAR_I2C3_SPEED for for the speed channel 3 2099 - CONFIF_SYS_RCAR_I2C_NUM_CONTROLLERS for number of i2c buses 2100 2101 - drivers/i2c/sh_i2c.c: 2102 - activate this driver with CONFIG_SYS_I2C_SH 2103 - This driver adds from 2 to 5 i2c buses 2104 2105 - CONFIG_SYS_I2C_SH_BASE0 for setting the register channel 0 2106 - CONFIG_SYS_I2C_SH_SPEED0 for for the speed channel 0 2107 - CONFIG_SYS_I2C_SH_BASE1 for setting the register channel 1 2108 - CONFIG_SYS_I2C_SH_SPEED1 for for the speed channel 1 2109 - CONFIG_SYS_I2C_SH_BASE2 for setting the register channel 2 2110 - CONFIG_SYS_I2C_SH_SPEED2 for for the speed channel 2 2111 - CONFIG_SYS_I2C_SH_BASE3 for setting the register channel 3 2112 - CONFIG_SYS_I2C_SH_SPEED3 for for the speed channel 3 2113 - CONFIG_SYS_I2C_SH_BASE4 for setting the register channel 4 2114 - CONFIG_SYS_I2C_SH_SPEED4 for for the speed channel 4 2115 - CONFIG_SYS_I2C_SH_NUM_CONTROLLERS for number of i2c buses 2116 2117 - drivers/i2c/omap24xx_i2c.c 2118 - activate this driver with CONFIG_SYS_I2C_OMAP24XX 2119 - CONFIG_SYS_OMAP24_I2C_SPEED speed channel 0 2120 - CONFIG_SYS_OMAP24_I2C_SLAVE slave addr channel 0 2121 - CONFIG_SYS_OMAP24_I2C_SPEED1 speed channel 1 2122 - CONFIG_SYS_OMAP24_I2C_SLAVE1 slave addr channel 1 2123 - CONFIG_SYS_OMAP24_I2C_SPEED2 speed channel 2 2124 - CONFIG_SYS_OMAP24_I2C_SLAVE2 slave addr channel 2 2125 - CONFIG_SYS_OMAP24_I2C_SPEED3 speed channel 3 2126 - CONFIG_SYS_OMAP24_I2C_SLAVE3 slave addr channel 3 2127 - CONFIG_SYS_OMAP24_I2C_SPEED4 speed channel 4 2128 - CONFIG_SYS_OMAP24_I2C_SLAVE4 slave addr channel 4 2129 2130 - drivers/i2c/zynq_i2c.c 2131 - activate this driver with CONFIG_SYS_I2C_ZYNQ 2132 - set CONFIG_SYS_I2C_ZYNQ_SPEED for speed setting 2133 - set CONFIG_SYS_I2C_ZYNQ_SLAVE for slave addr 2134 2135 - drivers/i2c/s3c24x0_i2c.c: 2136 - activate this driver with CONFIG_SYS_I2C_S3C24X0 2137 - This driver adds i2c buses (11 for Exynos5250, Exynos5420 2138 9 i2c buses for Exynos4 and 1 for S3C24X0 SoCs from Samsung) 2139 with a fix speed from 100000 and the slave addr 0! 2140 2141 - drivers/i2c/ihs_i2c.c 2142 - activate this driver with CONFIG_SYS_I2C_IHS 2143 - CONFIG_SYS_I2C_IHS_CH0 activate hardware channel 0 2144 - CONFIG_SYS_I2C_IHS_SPEED_0 speed channel 0 2145 - CONFIG_SYS_I2C_IHS_SLAVE_0 slave addr channel 0 2146 - CONFIG_SYS_I2C_IHS_CH1 activate hardware channel 1 2147 - CONFIG_SYS_I2C_IHS_SPEED_1 speed channel 1 2148 - CONFIG_SYS_I2C_IHS_SLAVE_1 slave addr channel 1 2149 - CONFIG_SYS_I2C_IHS_CH2 activate hardware channel 2 2150 - CONFIG_SYS_I2C_IHS_SPEED_2 speed channel 2 2151 - CONFIG_SYS_I2C_IHS_SLAVE_2 slave addr channel 2 2152 - CONFIG_SYS_I2C_IHS_CH3 activate hardware channel 3 2153 - CONFIG_SYS_I2C_IHS_SPEED_3 speed channel 3 2154 - CONFIG_SYS_I2C_IHS_SLAVE_3 slave addr channel 3 2155 - activate dual channel with CONFIG_SYS_I2C_IHS_DUAL 2156 - CONFIG_SYS_I2C_IHS_SPEED_0_1 speed channel 0_1 2157 - CONFIG_SYS_I2C_IHS_SLAVE_0_1 slave addr channel 0_1 2158 - CONFIG_SYS_I2C_IHS_SPEED_1_1 speed channel 1_1 2159 - CONFIG_SYS_I2C_IHS_SLAVE_1_1 slave addr channel 1_1 2160 - CONFIG_SYS_I2C_IHS_SPEED_2_1 speed channel 2_1 2161 - CONFIG_SYS_I2C_IHS_SLAVE_2_1 slave addr channel 2_1 2162 - CONFIG_SYS_I2C_IHS_SPEED_3_1 speed channel 3_1 2163 - CONFIG_SYS_I2C_IHS_SLAVE_3_1 slave addr channel 3_1 2164 2165 additional defines: 2166 2167 CONFIG_SYS_NUM_I2C_BUSES 2168 Hold the number of i2c buses you want to use. 2169 2170 CONFIG_SYS_I2C_DIRECT_BUS 2171 define this, if you don't use i2c muxes on your hardware. 2172 if CONFIG_SYS_I2C_MAX_HOPS is not defined or == 0 you can 2173 omit this define. 2174 2175 CONFIG_SYS_I2C_MAX_HOPS 2176 define how many muxes are maximal consecutively connected 2177 on one i2c bus. If you not use i2c muxes, omit this 2178 define. 2179 2180 CONFIG_SYS_I2C_BUSES 2181 hold a list of buses you want to use, only used if 2182 CONFIG_SYS_I2C_DIRECT_BUS is not defined, for example 2183 a board with CONFIG_SYS_I2C_MAX_HOPS = 1 and 2184 CONFIG_SYS_NUM_I2C_BUSES = 9: 2185 2186 CONFIG_SYS_I2C_BUSES {{0, {I2C_NULL_HOP}}, \ 2187 {0, {{I2C_MUX_PCA9547, 0x70, 1}}}, \ 2188 {0, {{I2C_MUX_PCA9547, 0x70, 2}}}, \ 2189 {0, {{I2C_MUX_PCA9547, 0x70, 3}}}, \ 2190 {0, {{I2C_MUX_PCA9547, 0x70, 4}}}, \ 2191 {0, {{I2C_MUX_PCA9547, 0x70, 5}}}, \ 2192 {1, {I2C_NULL_HOP}}, \ 2193 {1, {{I2C_MUX_PCA9544, 0x72, 1}}}, \ 2194 {1, {{I2C_MUX_PCA9544, 0x72, 2}}}, \ 2195 } 2196 2197 which defines 2198 bus 0 on adapter 0 without a mux 2199 bus 1 on adapter 0 with a PCA9547 on address 0x70 port 1 2200 bus 2 on adapter 0 with a PCA9547 on address 0x70 port 2 2201 bus 3 on adapter 0 with a PCA9547 on address 0x70 port 3 2202 bus 4 on adapter 0 with a PCA9547 on address 0x70 port 4 2203 bus 5 on adapter 0 with a PCA9547 on address 0x70 port 5 2204 bus 6 on adapter 1 without a mux 2205 bus 7 on adapter 1 with a PCA9544 on address 0x72 port 1 2206 bus 8 on adapter 1 with a PCA9544 on address 0x72 port 2 2207 2208 If you do not have i2c muxes on your board, omit this define. 2209 2210- Legacy I2C Support: CONFIG_HARD_I2C 2211 2212 NOTE: It is intended to move drivers to CONFIG_SYS_I2C which 2213 provides the following compelling advantages: 2214 2215 - more than one i2c adapter is usable 2216 - approved multibus support 2217 - better i2c mux support 2218 2219 ** Please consider updating your I2C driver now. ** 2220 2221 These enable legacy I2C serial bus commands. Defining 2222 CONFIG_HARD_I2C will include the appropriate I2C driver 2223 for the selected CPU. 2224 2225 This will allow you to use i2c commands at the u-boot 2226 command line (as long as you set CONFIG_CMD_I2C in 2227 CONFIG_COMMANDS) and communicate with i2c based realtime 2228 clock chips. See common/cmd_i2c.c for a description of the 2229 command line interface. 2230 2231 CONFIG_HARD_I2C selects a hardware I2C controller. 2232 2233 There are several other quantities that must also be 2234 defined when you define CONFIG_HARD_I2C. 2235 2236 In both cases you will need to define CONFIG_SYS_I2C_SPEED 2237 to be the frequency (in Hz) at which you wish your i2c bus 2238 to run and CONFIG_SYS_I2C_SLAVE to be the address of this node (ie 2239 the CPU's i2c node address). 2240 2241 Now, the u-boot i2c code for the mpc8xx 2242 (arch/powerpc/cpu/mpc8xx/i2c.c) sets the CPU up as a master node 2243 and so its address should therefore be cleared to 0 (See, 2244 eg, MPC823e User's Manual p.16-473). So, set 2245 CONFIG_SYS_I2C_SLAVE to 0. 2246 2247 CONFIG_SYS_I2C_INIT_MPC5XXX 2248 2249 When a board is reset during an i2c bus transfer 2250 chips might think that the current transfer is still 2251 in progress. Reset the slave devices by sending start 2252 commands until the slave device responds. 2253 2254 That's all that's required for CONFIG_HARD_I2C. 2255 2256 If you use the software i2c interface (CONFIG_SYS_I2C_SOFT) 2257 then the following macros need to be defined (examples are 2258 from include/configs/lwmon.h): 2259 2260 I2C_INIT 2261 2262 (Optional). Any commands necessary to enable the I2C 2263 controller or configure ports. 2264 2265 eg: #define I2C_INIT (immr->im_cpm.cp_pbdir |= PB_SCL) 2266 2267 I2C_PORT 2268 2269 (Only for MPC8260 CPU). The I/O port to use (the code 2270 assumes both bits are on the same port). Valid values 2271 are 0..3 for ports A..D. 2272 2273 I2C_ACTIVE 2274 2275 The code necessary to make the I2C data line active 2276 (driven). If the data line is open collector, this 2277 define can be null. 2278 2279 eg: #define I2C_ACTIVE (immr->im_cpm.cp_pbdir |= PB_SDA) 2280 2281 I2C_TRISTATE 2282 2283 The code necessary to make the I2C data line tri-stated 2284 (inactive). If the data line is open collector, this 2285 define can be null. 2286 2287 eg: #define I2C_TRISTATE (immr->im_cpm.cp_pbdir &= ~PB_SDA) 2288 2289 I2C_READ 2290 2291 Code that returns true if the I2C data line is high, 2292 false if it is low. 2293 2294 eg: #define I2C_READ ((immr->im_cpm.cp_pbdat & PB_SDA) != 0) 2295 2296 I2C_SDA(bit) 2297 2298 If <bit> is true, sets the I2C data line high. If it 2299 is false, it clears it (low). 2300 2301 eg: #define I2C_SDA(bit) \ 2302 if(bit) immr->im_cpm.cp_pbdat |= PB_SDA; \ 2303 else immr->im_cpm.cp_pbdat &= ~PB_SDA 2304 2305 I2C_SCL(bit) 2306 2307 If <bit> is true, sets the I2C clock line high. If it 2308 is false, it clears it (low). 2309 2310 eg: #define I2C_SCL(bit) \ 2311 if(bit) immr->im_cpm.cp_pbdat |= PB_SCL; \ 2312 else immr->im_cpm.cp_pbdat &= ~PB_SCL 2313 2314 I2C_DELAY 2315 2316 This delay is invoked four times per clock cycle so this 2317 controls the rate of data transfer. The data rate thus 2318 is 1 / (I2C_DELAY * 4). Often defined to be something 2319 like: 2320 2321 #define I2C_DELAY udelay(2) 2322 2323 CONFIG_SOFT_I2C_GPIO_SCL / CONFIG_SOFT_I2C_GPIO_SDA 2324 2325 If your arch supports the generic GPIO framework (asm/gpio.h), 2326 then you may alternatively define the two GPIOs that are to be 2327 used as SCL / SDA. Any of the previous I2C_xxx macros will 2328 have GPIO-based defaults assigned to them as appropriate. 2329 2330 You should define these to the GPIO value as given directly to 2331 the generic GPIO functions. 2332 2333 CONFIG_SYS_I2C_INIT_BOARD 2334 2335 When a board is reset during an i2c bus transfer 2336 chips might think that the current transfer is still 2337 in progress. On some boards it is possible to access 2338 the i2c SCLK line directly, either by using the 2339 processor pin as a GPIO or by having a second pin 2340 connected to the bus. If this option is defined a 2341 custom i2c_init_board() routine in boards/xxx/board.c 2342 is run early in the boot sequence. 2343 2344 CONFIG_SYS_I2C_BOARD_LATE_INIT 2345 2346 An alternative to CONFIG_SYS_I2C_INIT_BOARD. If this option is 2347 defined a custom i2c_board_late_init() routine in 2348 boards/xxx/board.c is run AFTER the operations in i2c_init() 2349 is completed. This callpoint can be used to unreset i2c bus 2350 using CPU i2c controller register accesses for CPUs whose i2c 2351 controller provide such a method. It is called at the end of 2352 i2c_init() to allow i2c_init operations to setup the i2c bus 2353 controller on the CPU (e.g. setting bus speed & slave address). 2354 2355 CONFIG_I2CFAST (PPC405GP|PPC405EP only) 2356 2357 This option enables configuration of bi_iic_fast[] flags 2358 in u-boot bd_info structure based on u-boot environment 2359 variable "i2cfast". (see also i2cfast) 2360 2361 CONFIG_I2C_MULTI_BUS 2362 2363 This option allows the use of multiple I2C buses, each of which 2364 must have a controller. At any point in time, only one bus is 2365 active. To switch to a different bus, use the 'i2c dev' command. 2366 Note that bus numbering is zero-based. 2367 2368 CONFIG_SYS_I2C_NOPROBES 2369 2370 This option specifies a list of I2C devices that will be skipped 2371 when the 'i2c probe' command is issued. If CONFIG_I2C_MULTI_BUS 2372 is set, specify a list of bus-device pairs. Otherwise, specify 2373 a 1D array of device addresses 2374 2375 e.g. 2376 #undef CONFIG_I2C_MULTI_BUS 2377 #define CONFIG_SYS_I2C_NOPROBES {0x50,0x68} 2378 2379 will skip addresses 0x50 and 0x68 on a board with one I2C bus 2380 2381 #define CONFIG_I2C_MULTI_BUS 2382 #define CONFIG_SYS_I2C_NOPROBES {{0,0x50},{0,0x68},{1,0x54}} 2383 2384 will skip addresses 0x50 and 0x68 on bus 0 and address 0x54 on bus 1 2385 2386 CONFIG_SYS_SPD_BUS_NUM 2387 2388 If defined, then this indicates the I2C bus number for DDR SPD. 2389 If not defined, then U-Boot assumes that SPD is on I2C bus 0. 2390 2391 CONFIG_SYS_RTC_BUS_NUM 2392 2393 If defined, then this indicates the I2C bus number for the RTC. 2394 If not defined, then U-Boot assumes that RTC is on I2C bus 0. 2395 2396 CONFIG_SYS_DTT_BUS_NUM 2397 2398 If defined, then this indicates the I2C bus number for the DTT. 2399 If not defined, then U-Boot assumes that DTT is on I2C bus 0. 2400 2401 CONFIG_SYS_I2C_DTT_ADDR: 2402 2403 If defined, specifies the I2C address of the DTT device. 2404 If not defined, then U-Boot uses predefined value for 2405 specified DTT device. 2406 2407 CONFIG_SOFT_I2C_READ_REPEATED_START 2408 2409 defining this will force the i2c_read() function in 2410 the soft_i2c driver to perform an I2C repeated start 2411 between writing the address pointer and reading the 2412 data. If this define is omitted the default behaviour 2413 of doing a stop-start sequence will be used. Most I2C 2414 devices can use either method, but some require one or 2415 the other. 2416 2417- SPI Support: CONFIG_SPI 2418 2419 Enables SPI driver (so far only tested with 2420 SPI EEPROM, also an instance works with Crystal A/D and 2421 D/As on the SACSng board) 2422 2423 CONFIG_SH_SPI 2424 2425 Enables the driver for SPI controller on SuperH. Currently 2426 only SH7757 is supported. 2427 2428 CONFIG_SOFT_SPI 2429 2430 Enables a software (bit-bang) SPI driver rather than 2431 using hardware support. This is a general purpose 2432 driver that only requires three general I/O port pins 2433 (two outputs, one input) to function. If this is 2434 defined, the board configuration must define several 2435 SPI configuration items (port pins to use, etc). For 2436 an example, see include/configs/sacsng.h. 2437 2438 CONFIG_HARD_SPI 2439 2440 Enables a hardware SPI driver for general-purpose reads 2441 and writes. As with CONFIG_SOFT_SPI, the board configuration 2442 must define a list of chip-select function pointers. 2443 Currently supported on some MPC8xxx processors. For an 2444 example, see include/configs/mpc8349emds.h. 2445 2446 CONFIG_MXC_SPI 2447 2448 Enables the driver for the SPI controllers on i.MX and MXC 2449 SoCs. Currently i.MX31/35/51 are supported. 2450 2451 CONFIG_SYS_SPI_MXC_WAIT 2452 Timeout for waiting until spi transfer completed. 2453 default: (CONFIG_SYS_HZ/100) /* 10 ms */ 2454 2455- FPGA Support: CONFIG_FPGA 2456 2457 Enables FPGA subsystem. 2458 2459 CONFIG_FPGA_<vendor> 2460 2461 Enables support for specific chip vendors. 2462 (ALTERA, XILINX) 2463 2464 CONFIG_FPGA_<family> 2465 2466 Enables support for FPGA family. 2467 (SPARTAN2, SPARTAN3, VIRTEX2, CYCLONE2, ACEX1K, ACEX) 2468 2469 CONFIG_FPGA_COUNT 2470 2471 Specify the number of FPGA devices to support. 2472 2473 CONFIG_CMD_FPGA_LOADMK 2474 2475 Enable support for fpga loadmk command 2476 2477 CONFIG_CMD_FPGA_LOADP 2478 2479 Enable support for fpga loadp command - load partial bitstream 2480 2481 CONFIG_CMD_FPGA_LOADBP 2482 2483 Enable support for fpga loadbp command - load partial bitstream 2484 (Xilinx only) 2485 2486 CONFIG_SYS_FPGA_PROG_FEEDBACK 2487 2488 Enable printing of hash marks during FPGA configuration. 2489 2490 CONFIG_SYS_FPGA_CHECK_BUSY 2491 2492 Enable checks on FPGA configuration interface busy 2493 status by the configuration function. This option 2494 will require a board or device specific function to 2495 be written. 2496 2497 CONFIG_FPGA_DELAY 2498 2499 If defined, a function that provides delays in the FPGA 2500 configuration driver. 2501 2502 CONFIG_SYS_FPGA_CHECK_CTRLC 2503 Allow Control-C to interrupt FPGA configuration 2504 2505 CONFIG_SYS_FPGA_CHECK_ERROR 2506 2507 Check for configuration errors during FPGA bitfile 2508 loading. For example, abort during Virtex II 2509 configuration if the INIT_B line goes low (which 2510 indicated a CRC error). 2511 2512 CONFIG_SYS_FPGA_WAIT_INIT 2513 2514 Maximum time to wait for the INIT_B line to de-assert 2515 after PROB_B has been de-asserted during a Virtex II 2516 FPGA configuration sequence. The default time is 500 2517 ms. 2518 2519 CONFIG_SYS_FPGA_WAIT_BUSY 2520 2521 Maximum time to wait for BUSY to de-assert during 2522 Virtex II FPGA configuration. The default is 5 ms. 2523 2524 CONFIG_SYS_FPGA_WAIT_CONFIG 2525 2526 Time to wait after FPGA configuration. The default is 2527 200 ms. 2528 2529- Configuration Management: 2530 CONFIG_BUILD_TARGET 2531 2532 Some SoCs need special image types (e.g. U-Boot binary 2533 with a special header) as build targets. By defining 2534 CONFIG_BUILD_TARGET in the SoC / board header, this 2535 special image will be automatically built upon calling 2536 make / buildman. 2537 2538 CONFIG_IDENT_STRING 2539 2540 If defined, this string will be added to the U-Boot 2541 version information (U_BOOT_VERSION) 2542 2543- Vendor Parameter Protection: 2544 2545 U-Boot considers the values of the environment 2546 variables "serial#" (Board Serial Number) and 2547 "ethaddr" (Ethernet Address) to be parameters that 2548 are set once by the board vendor / manufacturer, and 2549 protects these variables from casual modification by 2550 the user. Once set, these variables are read-only, 2551 and write or delete attempts are rejected. You can 2552 change this behaviour: 2553 2554 If CONFIG_ENV_OVERWRITE is #defined in your config 2555 file, the write protection for vendor parameters is 2556 completely disabled. Anybody can change or delete 2557 these parameters. 2558 2559 Alternatively, if you define _both_ an ethaddr in the 2560 default env _and_ CONFIG_OVERWRITE_ETHADDR_ONCE, a default 2561 Ethernet address is installed in the environment, 2562 which can be changed exactly ONCE by the user. [The 2563 serial# is unaffected by this, i. e. it remains 2564 read-only.] 2565 2566 The same can be accomplished in a more flexible way 2567 for any variable by configuring the type of access 2568 to allow for those variables in the ".flags" variable 2569 or define CONFIG_ENV_FLAGS_LIST_STATIC. 2570 2571- Protected RAM: 2572 CONFIG_PRAM 2573 2574 Define this variable to enable the reservation of 2575 "protected RAM", i. e. RAM which is not overwritten 2576 by U-Boot. Define CONFIG_PRAM to hold the number of 2577 kB you want to reserve for pRAM. You can overwrite 2578 this default value by defining an environment 2579 variable "pram" to the number of kB you want to 2580 reserve. Note that the board info structure will 2581 still show the full amount of RAM. If pRAM is 2582 reserved, a new environment variable "mem" will 2583 automatically be defined to hold the amount of 2584 remaining RAM in a form that can be passed as boot 2585 argument to Linux, for instance like that: 2586 2587 setenv bootargs ... mem=\${mem} 2588 saveenv 2589 2590 This way you can tell Linux not to use this memory, 2591 either, which results in a memory region that will 2592 not be affected by reboots. 2593 2594 *WARNING* If your board configuration uses automatic 2595 detection of the RAM size, you must make sure that 2596 this memory test is non-destructive. So far, the 2597 following board configurations are known to be 2598 "pRAM-clean": 2599 2600 IVMS8, IVML24, SPD8xx, TQM8xxL, 2601 HERMES, IP860, RPXlite, LWMON, 2602 FLAGADM, TQM8260 2603 2604- Access to physical memory region (> 4GB) 2605 Some basic support is provided for operations on memory not 2606 normally accessible to U-Boot - e.g. some architectures 2607 support access to more than 4GB of memory on 32-bit 2608 machines using physical address extension or similar. 2609 Define CONFIG_PHYSMEM to access this basic support, which 2610 currently only supports clearing the memory. 2611 2612- Error Recovery: 2613 CONFIG_PANIC_HANG 2614 2615 Define this variable to stop the system in case of a 2616 fatal error, so that you have to reset it manually. 2617 This is probably NOT a good idea for an embedded 2618 system where you want the system to reboot 2619 automatically as fast as possible, but it may be 2620 useful during development since you can try to debug 2621 the conditions that lead to the situation. 2622 2623 CONFIG_NET_RETRY_COUNT 2624 2625 This variable defines the number of retries for 2626 network operations like ARP, RARP, TFTP, or BOOTP 2627 before giving up the operation. If not defined, a 2628 default value of 5 is used. 2629 2630 CONFIG_ARP_TIMEOUT 2631 2632 Timeout waiting for an ARP reply in milliseconds. 2633 2634 CONFIG_NFS_TIMEOUT 2635 2636 Timeout in milliseconds used in NFS protocol. 2637 If you encounter "ERROR: Cannot umount" in nfs command, 2638 try longer timeout such as 2639 #define CONFIG_NFS_TIMEOUT 10000UL 2640 2641- Command Interpreter: 2642 CONFIG_AUTO_COMPLETE 2643 2644 Enable auto completion of commands using TAB. 2645 2646 CONFIG_SYS_PROMPT_HUSH_PS2 2647 2648 This defines the secondary prompt string, which is 2649 printed when the command interpreter needs more input 2650 to complete a command. Usually "> ". 2651 2652 Note: 2653 2654 In the current implementation, the local variables 2655 space and global environment variables space are 2656 separated. Local variables are those you define by 2657 simply typing `name=value'. To access a local 2658 variable later on, you have write `$name' or 2659 `${name}'; to execute the contents of a variable 2660 directly type `$name' at the command prompt. 2661 2662 Global environment variables are those you use 2663 setenv/printenv to work with. To run a command stored 2664 in such a variable, you need to use the run command, 2665 and you must not use the '$' sign to access them. 2666 2667 To store commands and special characters in a 2668 variable, please use double quotation marks 2669 surrounding the whole text of the variable, instead 2670 of the backslashes before semicolons and special 2671 symbols. 2672 2673- Command Line Editing and History: 2674 CONFIG_CMDLINE_EDITING 2675 2676 Enable editing and History functions for interactive 2677 command line input operations 2678 2679- Command Line PS1/PS2 support: 2680 CONFIG_CMDLINE_PS_SUPPORT 2681 2682 Enable support for changing the command prompt string 2683 at run-time. Only static string is supported so far. 2684 The string is obtained from environment variables PS1 2685 and PS2. 2686 2687- Default Environment: 2688 CONFIG_EXTRA_ENV_SETTINGS 2689 2690 Define this to contain any number of null terminated 2691 strings (variable = value pairs) that will be part of 2692 the default environment compiled into the boot image. 2693 2694 For example, place something like this in your 2695 board's config file: 2696 2697 #define CONFIG_EXTRA_ENV_SETTINGS \ 2698 "myvar1=value1\0" \ 2699 "myvar2=value2\0" 2700 2701 Warning: This method is based on knowledge about the 2702 internal format how the environment is stored by the 2703 U-Boot code. This is NOT an official, exported 2704 interface! Although it is unlikely that this format 2705 will change soon, there is no guarantee either. 2706 You better know what you are doing here. 2707 2708 Note: overly (ab)use of the default environment is 2709 discouraged. Make sure to check other ways to preset 2710 the environment like the "source" command or the 2711 boot command first. 2712 2713 CONFIG_ENV_VARS_UBOOT_CONFIG 2714 2715 Define this in order to add variables describing the 2716 U-Boot build configuration to the default environment. 2717 These will be named arch, cpu, board, vendor, and soc. 2718 2719 Enabling this option will cause the following to be defined: 2720 2721 - CONFIG_SYS_ARCH 2722 - CONFIG_SYS_CPU 2723 - CONFIG_SYS_BOARD 2724 - CONFIG_SYS_VENDOR 2725 - CONFIG_SYS_SOC 2726 2727 CONFIG_ENV_VARS_UBOOT_RUNTIME_CONFIG 2728 2729 Define this in order to add variables describing certain 2730 run-time determined information about the hardware to the 2731 environment. These will be named board_name, board_rev. 2732 2733 CONFIG_DELAY_ENVIRONMENT 2734 2735 Normally the environment is loaded when the board is 2736 initialised so that it is available to U-Boot. This inhibits 2737 that so that the environment is not available until 2738 explicitly loaded later by U-Boot code. With CONFIG_OF_CONTROL 2739 this is instead controlled by the value of 2740 /config/load-environment. 2741 2742- DataFlash Support: 2743 CONFIG_HAS_DATAFLASH 2744 2745 Defining this option enables DataFlash features and 2746 allows to read/write in Dataflash via the standard 2747 commands cp, md... 2748 2749- Serial Flash support 2750 CONFIG_CMD_SF 2751 2752 Defining this option enables SPI flash commands 2753 'sf probe/read/write/erase/update'. 2754 2755 Usage requires an initial 'probe' to define the serial 2756 flash parameters, followed by read/write/erase/update 2757 commands. 2758 2759 The following defaults may be provided by the platform 2760 to handle the common case when only a single serial 2761 flash is present on the system. 2762 2763 CONFIG_SF_DEFAULT_BUS Bus identifier 2764 CONFIG_SF_DEFAULT_CS Chip-select 2765 CONFIG_SF_DEFAULT_MODE (see include/spi.h) 2766 CONFIG_SF_DEFAULT_SPEED in Hz 2767 2768 CONFIG_CMD_SF_TEST 2769 2770 Define this option to include a destructive SPI flash 2771 test ('sf test'). 2772 2773 CONFIG_SF_DUAL_FLASH Dual flash memories 2774 2775 Define this option to use dual flash support where two flash 2776 memories can be connected with a given cs line. 2777 Currently Xilinx Zynq qspi supports these type of connections. 2778 2779- SystemACE Support: 2780 CONFIG_SYSTEMACE 2781 2782 Adding this option adds support for Xilinx SystemACE 2783 chips attached via some sort of local bus. The address 2784 of the chip must also be defined in the 2785 CONFIG_SYS_SYSTEMACE_BASE macro. For example: 2786 2787 #define CONFIG_SYSTEMACE 2788 #define CONFIG_SYS_SYSTEMACE_BASE 0xf0000000 2789 2790 When SystemACE support is added, the "ace" device type 2791 becomes available to the fat commands, i.e. fatls. 2792 2793- TFTP Fixed UDP Port: 2794 CONFIG_TFTP_PORT 2795 2796 If this is defined, the environment variable tftpsrcp 2797 is used to supply the TFTP UDP source port value. 2798 If tftpsrcp isn't defined, the normal pseudo-random port 2799 number generator is used. 2800 2801 Also, the environment variable tftpdstp is used to supply 2802 the TFTP UDP destination port value. If tftpdstp isn't 2803 defined, the normal port 69 is used. 2804 2805 The purpose for tftpsrcp is to allow a TFTP server to 2806 blindly start the TFTP transfer using the pre-configured 2807 target IP address and UDP port. This has the effect of 2808 "punching through" the (Windows XP) firewall, allowing 2809 the remainder of the TFTP transfer to proceed normally. 2810 A better solution is to properly configure the firewall, 2811 but sometimes that is not allowed. 2812 2813- Hashing support: 2814 CONFIG_CMD_HASH 2815 2816 This enables a generic 'hash' command which can produce 2817 hashes / digests from a few algorithms (e.g. SHA1, SHA256). 2818 2819 CONFIG_HASH_VERIFY 2820 2821 Enable the hash verify command (hash -v). This adds to code 2822 size a little. 2823 2824 CONFIG_SHA1 - This option enables support of hashing using SHA1 2825 algorithm. The hash is calculated in software. 2826 CONFIG_SHA256 - This option enables support of hashing using 2827 SHA256 algorithm. The hash is calculated in software. 2828 CONFIG_SHA_HW_ACCEL - This option enables hardware acceleration 2829 for SHA1/SHA256 hashing. 2830 This affects the 'hash' command and also the 2831 hash_lookup_algo() function. 2832 CONFIG_SHA_PROG_HW_ACCEL - This option enables 2833 hardware-acceleration for SHA1/SHA256 progressive hashing. 2834 Data can be streamed in a block at a time and the hashing 2835 is performed in hardware. 2836 2837 Note: There is also a sha1sum command, which should perhaps 2838 be deprecated in favour of 'hash sha1'. 2839 2840- Freescale i.MX specific commands: 2841 CONFIG_CMD_HDMIDETECT 2842 This enables 'hdmidet' command which returns true if an 2843 HDMI monitor is detected. This command is i.MX 6 specific. 2844 2845- bootcount support: 2846 CONFIG_BOOTCOUNT_LIMIT 2847 2848 This enables the bootcounter support, see: 2849 http://www.denx.de/wiki/DULG/UBootBootCountLimit 2850 2851 CONFIG_AT91SAM9XE 2852 enable special bootcounter support on at91sam9xe based boards. 2853 CONFIG_SOC_DA8XX 2854 enable special bootcounter support on da850 based boards. 2855 CONFIG_BOOTCOUNT_RAM 2856 enable support for the bootcounter in RAM 2857 CONFIG_BOOTCOUNT_I2C 2858 enable support for the bootcounter on an i2c (like RTC) device. 2859 CONFIG_SYS_I2C_RTC_ADDR = i2c chip address 2860 CONFIG_SYS_BOOTCOUNT_ADDR = i2c addr which is used for 2861 the bootcounter. 2862 CONFIG_BOOTCOUNT_ALEN = address len 2863 2864- Show boot progress: 2865 CONFIG_SHOW_BOOT_PROGRESS 2866 2867 Defining this option allows to add some board- 2868 specific code (calling a user-provided function 2869 "show_boot_progress(int)") that enables you to show 2870 the system's boot progress on some display (for 2871 example, some LED's) on your board. At the moment, 2872 the following checkpoints are implemented: 2873 2874 2875Legacy uImage format: 2876 2877 Arg Where When 2878 1 common/cmd_bootm.c before attempting to boot an image 2879 -1 common/cmd_bootm.c Image header has bad magic number 2880 2 common/cmd_bootm.c Image header has correct magic number 2881 -2 common/cmd_bootm.c Image header has bad checksum 2882 3 common/cmd_bootm.c Image header has correct checksum 2883 -3 common/cmd_bootm.c Image data has bad checksum 2884 4 common/cmd_bootm.c Image data has correct checksum 2885 -4 common/cmd_bootm.c Image is for unsupported architecture 2886 5 common/cmd_bootm.c Architecture check OK 2887 -5 common/cmd_bootm.c Wrong Image Type (not kernel, multi) 2888 6 common/cmd_bootm.c Image Type check OK 2889 -6 common/cmd_bootm.c gunzip uncompression error 2890 -7 common/cmd_bootm.c Unimplemented compression type 2891 7 common/cmd_bootm.c Uncompression OK 2892 8 common/cmd_bootm.c No uncompress/copy overwrite error 2893 -9 common/cmd_bootm.c Unsupported OS (not Linux, BSD, VxWorks, QNX) 2894 2895 9 common/image.c Start initial ramdisk verification 2896 -10 common/image.c Ramdisk header has bad magic number 2897 -11 common/image.c Ramdisk header has bad checksum 2898 10 common/image.c Ramdisk header is OK 2899 -12 common/image.c Ramdisk data has bad checksum 2900 11 common/image.c Ramdisk data has correct checksum 2901 12 common/image.c Ramdisk verification complete, start loading 2902 -13 common/image.c Wrong Image Type (not PPC Linux ramdisk) 2903 13 common/image.c Start multifile image verification 2904 14 common/image.c No initial ramdisk, no multifile, continue. 2905 2906 15 arch/<arch>/lib/bootm.c All preparation done, transferring control to OS 2907 2908 -30 arch/powerpc/lib/board.c Fatal error, hang the system 2909 -31 post/post.c POST test failed, detected by post_output_backlog() 2910 -32 post/post.c POST test failed, detected by post_run_single() 2911 2912 34 common/cmd_doc.c before loading a Image from a DOC device 2913 -35 common/cmd_doc.c Bad usage of "doc" command 2914 35 common/cmd_doc.c correct usage of "doc" command 2915 -36 common/cmd_doc.c No boot device 2916 36 common/cmd_doc.c correct boot device 2917 -37 common/cmd_doc.c Unknown Chip ID on boot device 2918 37 common/cmd_doc.c correct chip ID found, device available 2919 -38 common/cmd_doc.c Read Error on boot device 2920 38 common/cmd_doc.c reading Image header from DOC device OK 2921 -39 common/cmd_doc.c Image header has bad magic number 2922 39 common/cmd_doc.c Image header has correct magic number 2923 -40 common/cmd_doc.c Error reading Image from DOC device 2924 40 common/cmd_doc.c Image header has correct magic number 2925 41 common/cmd_ide.c before loading a Image from a IDE device 2926 -42 common/cmd_ide.c Bad usage of "ide" command 2927 42 common/cmd_ide.c correct usage of "ide" command 2928 -43 common/cmd_ide.c No boot device 2929 43 common/cmd_ide.c boot device found 2930 -44 common/cmd_ide.c Device not available 2931 44 common/cmd_ide.c Device available 2932 -45 common/cmd_ide.c wrong partition selected 2933 45 common/cmd_ide.c partition selected 2934 -46 common/cmd_ide.c Unknown partition table 2935 46 common/cmd_ide.c valid partition table found 2936 -47 common/cmd_ide.c Invalid partition type 2937 47 common/cmd_ide.c correct partition type 2938 -48 common/cmd_ide.c Error reading Image Header on boot device 2939 48 common/cmd_ide.c reading Image Header from IDE device OK 2940 -49 common/cmd_ide.c Image header has bad magic number 2941 49 common/cmd_ide.c Image header has correct magic number 2942 -50 common/cmd_ide.c Image header has bad checksum 2943 50 common/cmd_ide.c Image header has correct checksum 2944 -51 common/cmd_ide.c Error reading Image from IDE device 2945 51 common/cmd_ide.c reading Image from IDE device OK 2946 52 common/cmd_nand.c before loading a Image from a NAND device 2947 -53 common/cmd_nand.c Bad usage of "nand" command 2948 53 common/cmd_nand.c correct usage of "nand" command 2949 -54 common/cmd_nand.c No boot device 2950 54 common/cmd_nand.c boot device found 2951 -55 common/cmd_nand.c Unknown Chip ID on boot device 2952 55 common/cmd_nand.c correct chip ID found, device available 2953 -56 common/cmd_nand.c Error reading Image Header on boot device 2954 56 common/cmd_nand.c reading Image Header from NAND device OK 2955 -57 common/cmd_nand.c Image header has bad magic number 2956 57 common/cmd_nand.c Image header has correct magic number 2957 -58 common/cmd_nand.c Error reading Image from NAND device 2958 58 common/cmd_nand.c reading Image from NAND device OK 2959 2960 -60 common/env_common.c Environment has a bad CRC, using default 2961 2962 64 net/eth.c starting with Ethernet configuration. 2963 -64 net/eth.c no Ethernet found. 2964 65 net/eth.c Ethernet found. 2965 2966 -80 common/cmd_net.c usage wrong 2967 80 common/cmd_net.c before calling net_loop() 2968 -81 common/cmd_net.c some error in net_loop() occurred 2969 81 common/cmd_net.c net_loop() back without error 2970 -82 common/cmd_net.c size == 0 (File with size 0 loaded) 2971 82 common/cmd_net.c trying automatic boot 2972 83 common/cmd_net.c running "source" command 2973 -83 common/cmd_net.c some error in automatic boot or "source" command 2974 84 common/cmd_net.c end without errors 2975 2976FIT uImage format: 2977 2978 Arg Where When 2979 100 common/cmd_bootm.c Kernel FIT Image has correct format 2980 -100 common/cmd_bootm.c Kernel FIT Image has incorrect format 2981 101 common/cmd_bootm.c No Kernel subimage unit name, using configuration 2982 -101 common/cmd_bootm.c Can't get configuration for kernel subimage 2983 102 common/cmd_bootm.c Kernel unit name specified 2984 -103 common/cmd_bootm.c Can't get kernel subimage node offset 2985 103 common/cmd_bootm.c Found configuration node 2986 104 common/cmd_bootm.c Got kernel subimage node offset 2987 -104 common/cmd_bootm.c Kernel subimage hash verification failed 2988 105 common/cmd_bootm.c Kernel subimage hash verification OK 2989 -105 common/cmd_bootm.c Kernel subimage is for unsupported architecture 2990 106 common/cmd_bootm.c Architecture check OK 2991 -106 common/cmd_bootm.c Kernel subimage has wrong type 2992 107 common/cmd_bootm.c Kernel subimage type OK 2993 -107 common/cmd_bootm.c Can't get kernel subimage data/size 2994 108 common/cmd_bootm.c Got kernel subimage data/size 2995 -108 common/cmd_bootm.c Wrong image type (not legacy, FIT) 2996 -109 common/cmd_bootm.c Can't get kernel subimage type 2997 -110 common/cmd_bootm.c Can't get kernel subimage comp 2998 -111 common/cmd_bootm.c Can't get kernel subimage os 2999 -112 common/cmd_bootm.c Can't get kernel subimage load address 3000 -113 common/cmd_bootm.c Image uncompress/copy overwrite error 3001 3002 120 common/image.c Start initial ramdisk verification 3003 -120 common/image.c Ramdisk FIT image has incorrect format 3004 121 common/image.c Ramdisk FIT image has correct format 3005 122 common/image.c No ramdisk subimage unit name, using configuration 3006 -122 common/image.c Can't get configuration for ramdisk subimage 3007 123 common/image.c Ramdisk unit name specified 3008 -124 common/image.c Can't get ramdisk subimage node offset 3009 125 common/image.c Got ramdisk subimage node offset 3010 -125 common/image.c Ramdisk subimage hash verification failed 3011 126 common/image.c Ramdisk subimage hash verification OK 3012 -126 common/image.c Ramdisk subimage for unsupported architecture 3013 127 common/image.c Architecture check OK 3014 -127 common/image.c Can't get ramdisk subimage data/size 3015 128 common/image.c Got ramdisk subimage data/size 3016 129 common/image.c Can't get ramdisk load address 3017 -129 common/image.c Got ramdisk load address 3018 3019 -130 common/cmd_doc.c Incorrect FIT image format 3020 131 common/cmd_doc.c FIT image format OK 3021 3022 -140 common/cmd_ide.c Incorrect FIT image format 3023 141 common/cmd_ide.c FIT image format OK 3024 3025 -150 common/cmd_nand.c Incorrect FIT image format 3026 151 common/cmd_nand.c FIT image format OK 3027 3028- legacy image format: 3029 CONFIG_IMAGE_FORMAT_LEGACY 3030 enables the legacy image format support in U-Boot. 3031 3032 Default: 3033 enabled if CONFIG_FIT_SIGNATURE is not defined. 3034 3035 CONFIG_DISABLE_IMAGE_LEGACY 3036 disable the legacy image format 3037 3038 This define is introduced, as the legacy image format is 3039 enabled per default for backward compatibility. 3040 3041- FIT image support: 3042 CONFIG_FIT_DISABLE_SHA256 3043 Supporting SHA256 hashes has quite an impact on binary size. 3044 For constrained systems sha256 hash support can be disabled 3045 with this option. 3046 3047 TODO(sjg@chromium.org): Adjust this option to be positive, 3048 and move it to Kconfig 3049 3050- Standalone program support: 3051 CONFIG_STANDALONE_LOAD_ADDR 3052 3053 This option defines a board specific value for the 3054 address where standalone program gets loaded, thus 3055 overwriting the architecture dependent default 3056 settings. 3057 3058- Frame Buffer Address: 3059 CONFIG_FB_ADDR 3060 3061 Define CONFIG_FB_ADDR if you want to use specific 3062 address for frame buffer. This is typically the case 3063 when using a graphics controller has separate video 3064 memory. U-Boot will then place the frame buffer at 3065 the given address instead of dynamically reserving it 3066 in system RAM by calling lcd_setmem(), which grabs 3067 the memory for the frame buffer depending on the 3068 configured panel size. 3069 3070 Please see board_init_f function. 3071 3072- Automatic software updates via TFTP server 3073 CONFIG_UPDATE_TFTP 3074 CONFIG_UPDATE_TFTP_CNT_MAX 3075 CONFIG_UPDATE_TFTP_MSEC_MAX 3076 3077 These options enable and control the auto-update feature; 3078 for a more detailed description refer to doc/README.update. 3079 3080- MTD Support (mtdparts command, UBI support) 3081 CONFIG_MTD_DEVICE 3082 3083 Adds the MTD device infrastructure from the Linux kernel. 3084 Needed for mtdparts command support. 3085 3086 CONFIG_MTD_PARTITIONS 3087 3088 Adds the MTD partitioning infrastructure from the Linux 3089 kernel. Needed for UBI support. 3090 3091- UBI support 3092 CONFIG_CMD_UBI 3093 3094 Adds commands for interacting with MTD partitions formatted 3095 with the UBI flash translation layer 3096 3097 Requires also defining CONFIG_RBTREE 3098 3099 CONFIG_UBI_SILENCE_MSG 3100 3101 Make the verbose messages from UBI stop printing. This leaves 3102 warnings and errors enabled. 3103 3104 3105 CONFIG_MTD_UBI_WL_THRESHOLD 3106 This parameter defines the maximum difference between the highest 3107 erase counter value and the lowest erase counter value of eraseblocks 3108 of UBI devices. When this threshold is exceeded, UBI starts performing 3109 wear leveling by means of moving data from eraseblock with low erase 3110 counter to eraseblocks with high erase counter. 3111 3112 The default value should be OK for SLC NAND flashes, NOR flashes and 3113 other flashes which have eraseblock life-cycle 100000 or more. 3114 However, in case of MLC NAND flashes which typically have eraseblock 3115 life-cycle less than 10000, the threshold should be lessened (e.g., 3116 to 128 or 256, although it does not have to be power of 2). 3117 3118 default: 4096 3119 3120 CONFIG_MTD_UBI_BEB_LIMIT 3121 This option specifies the maximum bad physical eraseblocks UBI 3122 expects on the MTD device (per 1024 eraseblocks). If the 3123 underlying flash does not admit of bad eraseblocks (e.g. NOR 3124 flash), this value is ignored. 3125 3126 NAND datasheets often specify the minimum and maximum NVM 3127 (Number of Valid Blocks) for the flashes' endurance lifetime. 3128 The maximum expected bad eraseblocks per 1024 eraseblocks 3129 then can be calculated as "1024 * (1 - MinNVB / MaxNVB)", 3130 which gives 20 for most NANDs (MaxNVB is basically the total 3131 count of eraseblocks on the chip). 3132 3133 To put it differently, if this value is 20, UBI will try to 3134 reserve about 1.9% of physical eraseblocks for bad blocks 3135 handling. And that will be 1.9% of eraseblocks on the entire 3136 NAND chip, not just the MTD partition UBI attaches. This means 3137 that if you have, say, a NAND flash chip admits maximum 40 bad 3138 eraseblocks, and it is split on two MTD partitions of the same 3139 size, UBI will reserve 40 eraseblocks when attaching a 3140 partition. 3141 3142 default: 20 3143 3144 CONFIG_MTD_UBI_FASTMAP 3145 Fastmap is a mechanism which allows attaching an UBI device 3146 in nearly constant time. Instead of scanning the whole MTD device it 3147 only has to locate a checkpoint (called fastmap) on the device. 3148 The on-flash fastmap contains all information needed to attach 3149 the device. Using fastmap makes only sense on large devices where 3150 attaching by scanning takes long. UBI will not automatically install 3151 a fastmap on old images, but you can set the UBI parameter 3152 CONFIG_MTD_UBI_FASTMAP_AUTOCONVERT to 1 if you want so. Please note 3153 that fastmap-enabled images are still usable with UBI implementations 3154 without fastmap support. On typical flash devices the whole fastmap 3155 fits into one PEB. UBI will reserve PEBs to hold two fastmaps. 3156 3157 CONFIG_MTD_UBI_FASTMAP_AUTOCONVERT 3158 Set this parameter to enable fastmap automatically on images 3159 without a fastmap. 3160 default: 0 3161 3162 CONFIG_MTD_UBI_FM_DEBUG 3163 Enable UBI fastmap debug 3164 default: 0 3165 3166- UBIFS support 3167 CONFIG_CMD_UBIFS 3168 3169 Adds commands for interacting with UBI volumes formatted as 3170 UBIFS. UBIFS is read-only in u-boot. 3171 3172 Requires UBI support as well as CONFIG_LZO 3173 3174 CONFIG_UBIFS_SILENCE_MSG 3175 3176 Make the verbose messages from UBIFS stop printing. This leaves 3177 warnings and errors enabled. 3178 3179- SPL framework 3180 CONFIG_SPL 3181 Enable building of SPL globally. 3182 3183 CONFIG_SPL_LDSCRIPT 3184 LDSCRIPT for linking the SPL binary. 3185 3186 CONFIG_SPL_MAX_FOOTPRINT 3187 Maximum size in memory allocated to the SPL, BSS included. 3188 When defined, the linker checks that the actual memory 3189 used by SPL from _start to __bss_end does not exceed it. 3190 CONFIG_SPL_MAX_FOOTPRINT and CONFIG_SPL_BSS_MAX_SIZE 3191 must not be both defined at the same time. 3192 3193 CONFIG_SPL_MAX_SIZE 3194 Maximum size of the SPL image (text, data, rodata, and 3195 linker lists sections), BSS excluded. 3196 When defined, the linker checks that the actual size does 3197 not exceed it. 3198 3199 CONFIG_SPL_TEXT_BASE 3200 TEXT_BASE for linking the SPL binary. 3201 3202 CONFIG_SPL_RELOC_TEXT_BASE 3203 Address to relocate to. If unspecified, this is equal to 3204 CONFIG_SPL_TEXT_BASE (i.e. no relocation is done). 3205 3206 CONFIG_SPL_BSS_START_ADDR 3207 Link address for the BSS within the SPL binary. 3208 3209 CONFIG_SPL_BSS_MAX_SIZE 3210 Maximum size in memory allocated to the SPL BSS. 3211 When defined, the linker checks that the actual memory used 3212 by SPL from __bss_start to __bss_end does not exceed it. 3213 CONFIG_SPL_MAX_FOOTPRINT and CONFIG_SPL_BSS_MAX_SIZE 3214 must not be both defined at the same time. 3215 3216 CONFIG_SPL_STACK 3217 Adress of the start of the stack SPL will use 3218 3219 CONFIG_SPL_PANIC_ON_RAW_IMAGE 3220 When defined, SPL will panic() if the image it has 3221 loaded does not have a signature. 3222 Defining this is useful when code which loads images 3223 in SPL cannot guarantee that absolutely all read errors 3224 will be caught. 3225 An example is the LPC32XX MLC NAND driver, which will 3226 consider that a completely unreadable NAND block is bad, 3227 and thus should be skipped silently. 3228 3229 CONFIG_SPL_RELOC_STACK 3230 Adress of the start of the stack SPL will use after 3231 relocation. If unspecified, this is equal to 3232 CONFIG_SPL_STACK. 3233 3234 CONFIG_SYS_SPL_MALLOC_START 3235 Starting address of the malloc pool used in SPL. 3236 When this option is set the full malloc is used in SPL and 3237 it is set up by spl_init() and before that, the simple malloc() 3238 can be used if CONFIG_SYS_MALLOC_F is defined. 3239 3240 CONFIG_SYS_SPL_MALLOC_SIZE 3241 The size of the malloc pool used in SPL. 3242 3243 CONFIG_SPL_FRAMEWORK 3244 Enable the SPL framework under common/. This framework 3245 supports MMC, NAND and YMODEM loading of U-Boot and NAND 3246 NAND loading of the Linux Kernel. 3247 3248 CONFIG_SPL_OS_BOOT 3249 Enable booting directly to an OS from SPL. 3250 See also: doc/README.falcon 3251 3252 CONFIG_SPL_DISPLAY_PRINT 3253 For ARM, enable an optional function to print more information 3254 about the running system. 3255 3256 CONFIG_SPL_INIT_MINIMAL 3257 Arch init code should be built for a very small image 3258 3259 CONFIG_SYS_MMCSD_RAW_MODE_U_BOOT_PARTITION 3260 Partition on the MMC to load U-Boot from when the MMC is being 3261 used in raw mode 3262 3263 CONFIG_SYS_MMCSD_RAW_MODE_KERNEL_SECTOR 3264 Sector to load kernel uImage from when MMC is being 3265 used in raw mode (for Falcon mode) 3266 3267 CONFIG_SYS_MMCSD_RAW_MODE_ARGS_SECTOR, 3268 CONFIG_SYS_MMCSD_RAW_MODE_ARGS_SECTORS 3269 Sector and number of sectors to load kernel argument 3270 parameters from when MMC is being used in raw mode 3271 (for falcon mode) 3272 3273 CONFIG_SYS_MMCSD_FS_BOOT_PARTITION 3274 Partition on the MMC to load U-Boot from when the MMC is being 3275 used in fs mode 3276 3277 CONFIG_SPL_FS_LOAD_PAYLOAD_NAME 3278 Filename to read to load U-Boot when reading from filesystem 3279 3280 CONFIG_SPL_FS_LOAD_KERNEL_NAME 3281 Filename to read to load kernel uImage when reading 3282 from filesystem (for Falcon mode) 3283 3284 CONFIG_SPL_FS_LOAD_ARGS_NAME 3285 Filename to read to load kernel argument parameters 3286 when reading from filesystem (for Falcon mode) 3287 3288 CONFIG_SPL_MPC83XX_WAIT_FOR_NAND 3289 Set this for NAND SPL on PPC mpc83xx targets, so that 3290 start.S waits for the rest of the SPL to load before 3291 continuing (the hardware starts execution after just 3292 loading the first page rather than the full 4K). 3293 3294 CONFIG_SPL_SKIP_RELOCATE 3295 Avoid SPL relocation 3296 3297 CONFIG_SPL_NAND_BASE 3298 Include nand_base.c in the SPL. Requires 3299 CONFIG_SPL_NAND_DRIVERS. 3300 3301 CONFIG_SPL_NAND_DRIVERS 3302 SPL uses normal NAND drivers, not minimal drivers. 3303 3304 CONFIG_SPL_NAND_ECC 3305 Include standard software ECC in the SPL 3306 3307 CONFIG_SPL_NAND_SIMPLE 3308 Support for NAND boot using simple NAND drivers that 3309 expose the cmd_ctrl() interface. 3310 3311 CONFIG_SPL_UBI 3312 Support for a lightweight UBI (fastmap) scanner and 3313 loader 3314 3315 CONFIG_SPL_NAND_RAW_ONLY 3316 Support to boot only raw u-boot.bin images. Use this only 3317 if you need to save space. 3318 3319 CONFIG_SPL_COMMON_INIT_DDR 3320 Set for common ddr init with serial presence detect in 3321 SPL binary. 3322 3323 CONFIG_SYS_NAND_5_ADDR_CYCLE, CONFIG_SYS_NAND_PAGE_COUNT, 3324 CONFIG_SYS_NAND_PAGE_SIZE, CONFIG_SYS_NAND_OOBSIZE, 3325 CONFIG_SYS_NAND_BLOCK_SIZE, CONFIG_SYS_NAND_BAD_BLOCK_POS, 3326 CONFIG_SYS_NAND_ECCPOS, CONFIG_SYS_NAND_ECCSIZE, 3327 CONFIG_SYS_NAND_ECCBYTES 3328 Defines the size and behavior of the NAND that SPL uses 3329 to read U-Boot 3330 3331 CONFIG_SPL_NAND_BOOT 3332 Add support NAND boot 3333 3334 CONFIG_SYS_NAND_U_BOOT_OFFS 3335 Location in NAND to read U-Boot from 3336 3337 CONFIG_SYS_NAND_U_BOOT_DST 3338 Location in memory to load U-Boot to 3339 3340 CONFIG_SYS_NAND_U_BOOT_SIZE 3341 Size of image to load 3342 3343 CONFIG_SYS_NAND_U_BOOT_START 3344 Entry point in loaded image to jump to 3345 3346 CONFIG_SYS_NAND_HW_ECC_OOBFIRST 3347 Define this if you need to first read the OOB and then the 3348 data. This is used, for example, on davinci platforms. 3349 3350 CONFIG_SPL_OMAP3_ID_NAND 3351 Support for an OMAP3-specific set of functions to return the 3352 ID and MFR of the first attached NAND chip, if present. 3353 3354 CONFIG_SPL_RAM_DEVICE 3355 Support for running image already present in ram, in SPL binary 3356 3357 CONFIG_SPL_PAD_TO 3358 Image offset to which the SPL should be padded before appending 3359 the SPL payload. By default, this is defined as 3360 CONFIG_SPL_MAX_SIZE, or 0 if CONFIG_SPL_MAX_SIZE is undefined. 3361 CONFIG_SPL_PAD_TO must be either 0, meaning to append the SPL 3362 payload without any padding, or >= CONFIG_SPL_MAX_SIZE. 3363 3364 CONFIG_SPL_TARGET 3365 Final target image containing SPL and payload. Some SPLs 3366 use an arch-specific makefile fragment instead, for 3367 example if more than one image needs to be produced. 3368 3369 CONFIG_FIT_SPL_PRINT 3370 Printing information about a FIT image adds quite a bit of 3371 code to SPL. So this is normally disabled in SPL. Use this 3372 option to re-enable it. This will affect the output of the 3373 bootm command when booting a FIT image. 3374 3375- TPL framework 3376 CONFIG_TPL 3377 Enable building of TPL globally. 3378 3379 CONFIG_TPL_PAD_TO 3380 Image offset to which the TPL should be padded before appending 3381 the TPL payload. By default, this is defined as 3382 CONFIG_SPL_MAX_SIZE, or 0 if CONFIG_SPL_MAX_SIZE is undefined. 3383 CONFIG_SPL_PAD_TO must be either 0, meaning to append the SPL 3384 payload without any padding, or >= CONFIG_SPL_MAX_SIZE. 3385 3386- Interrupt support (PPC): 3387 3388 There are common interrupt_init() and timer_interrupt() 3389 for all PPC archs. interrupt_init() calls interrupt_init_cpu() 3390 for CPU specific initialization. interrupt_init_cpu() 3391 should set decrementer_count to appropriate value. If 3392 CPU resets decrementer automatically after interrupt 3393 (ppc4xx) it should set decrementer_count to zero. 3394 timer_interrupt() calls timer_interrupt_cpu() for CPU 3395 specific handling. If board has watchdog / status_led 3396 / other_activity_monitor it works automatically from 3397 general timer_interrupt(). 3398 3399 3400Board initialization settings: 3401------------------------------ 3402 3403During Initialization u-boot calls a number of board specific functions 3404to allow the preparation of board specific prerequisites, e.g. pin setup 3405before drivers are initialized. To enable these callbacks the 3406following configuration macros have to be defined. Currently this is 3407architecture specific, so please check arch/your_architecture/lib/board.c 3408typically in board_init_f() and board_init_r(). 3409 3410- CONFIG_BOARD_EARLY_INIT_F: Call board_early_init_f() 3411- CONFIG_BOARD_EARLY_INIT_R: Call board_early_init_r() 3412- CONFIG_BOARD_LATE_INIT: Call board_late_init() 3413- CONFIG_BOARD_POSTCLK_INIT: Call board_postclk_init() 3414 3415Configuration Settings: 3416----------------------- 3417 3418- CONFIG_SYS_SUPPORT_64BIT_DATA: Defined automatically if compiled as 64-bit. 3419 Optionally it can be defined to support 64-bit memory commands. 3420 3421- CONFIG_SYS_LONGHELP: Defined when you want long help messages included; 3422 undefine this when you're short of memory. 3423 3424- CONFIG_SYS_HELP_CMD_WIDTH: Defined when you want to override the default 3425 width of the commands listed in the 'help' command output. 3426 3427- CONFIG_SYS_PROMPT: This is what U-Boot prints on the console to 3428 prompt for user input. 3429 3430- CONFIG_SYS_CBSIZE: Buffer size for input from the Console 3431 3432- CONFIG_SYS_PBSIZE: Buffer size for Console output 3433 3434- CONFIG_SYS_MAXARGS: max. Number of arguments accepted for monitor commands 3435 3436- CONFIG_SYS_BARGSIZE: Buffer size for Boot Arguments which are passed to 3437 the application (usually a Linux kernel) when it is 3438 booted 3439 3440- CONFIG_SYS_BAUDRATE_TABLE: 3441 List of legal baudrate settings for this board. 3442 3443- CONFIG_SYS_MEMTEST_START, CONFIG_SYS_MEMTEST_END: 3444 Begin and End addresses of the area used by the 3445 simple memory test. 3446 3447- CONFIG_SYS_ALT_MEMTEST: 3448 Enable an alternate, more extensive memory test. 3449 3450- CONFIG_SYS_MEMTEST_SCRATCH: 3451 Scratch address used by the alternate memory test 3452 You only need to set this if address zero isn't writeable 3453 3454- CONFIG_SYS_MEM_RESERVE_SECURE 3455 Only implemented for ARMv8 for now. 3456 If defined, the size of CONFIG_SYS_MEM_RESERVE_SECURE memory 3457 is substracted from total RAM and won't be reported to OS. 3458 This memory can be used as secure memory. A variable 3459 gd->arch.secure_ram is used to track the location. In systems 3460 the RAM base is not zero, or RAM is divided into banks, 3461 this variable needs to be recalcuated to get the address. 3462 3463- CONFIG_SYS_MEM_TOP_HIDE: 3464 If CONFIG_SYS_MEM_TOP_HIDE is defined in the board config header, 3465 this specified memory area will get subtracted from the top 3466 (end) of RAM and won't get "touched" at all by U-Boot. By 3467 fixing up gd->ram_size the Linux kernel should gets passed 3468 the now "corrected" memory size and won't touch it either. 3469 This should work for arch/ppc and arch/powerpc. Only Linux 3470 board ports in arch/powerpc with bootwrapper support that 3471 recalculate the memory size from the SDRAM controller setup 3472 will have to get fixed in Linux additionally. 3473 3474 This option can be used as a workaround for the 440EPx/GRx 3475 CHIP 11 errata where the last 256 bytes in SDRAM shouldn't 3476 be touched. 3477 3478 WARNING: Please make sure that this value is a multiple of 3479 the Linux page size (normally 4k). If this is not the case, 3480 then the end address of the Linux memory will be located at a 3481 non page size aligned address and this could cause major 3482 problems. 3483 3484- CONFIG_SYS_LOADS_BAUD_CHANGE: 3485 Enable temporary baudrate change while serial download 3486 3487- CONFIG_SYS_SDRAM_BASE: 3488 Physical start address of SDRAM. _Must_ be 0 here. 3489 3490- CONFIG_SYS_FLASH_BASE: 3491 Physical start address of Flash memory. 3492 3493- CONFIG_SYS_MONITOR_BASE: 3494 Physical start address of boot monitor code (set by 3495 make config files to be same as the text base address 3496 (CONFIG_SYS_TEXT_BASE) used when linking) - same as 3497 CONFIG_SYS_FLASH_BASE when booting from flash. 3498 3499- CONFIG_SYS_MONITOR_LEN: 3500 Size of memory reserved for monitor code, used to 3501 determine _at_compile_time_ (!) if the environment is 3502 embedded within the U-Boot image, or in a separate 3503 flash sector. 3504 3505- CONFIG_SYS_MALLOC_LEN: 3506 Size of DRAM reserved for malloc() use. 3507 3508- CONFIG_SYS_MALLOC_F_LEN 3509 Size of the malloc() pool for use before relocation. If 3510 this is defined, then a very simple malloc() implementation 3511 will become available before relocation. The address is just 3512 below the global data, and the stack is moved down to make 3513 space. 3514 3515 This feature allocates regions with increasing addresses 3516 within the region. calloc() is supported, but realloc() 3517 is not available. free() is supported but does nothing. 3518 The memory will be freed (or in fact just forgotten) when 3519 U-Boot relocates itself. 3520 3521- CONFIG_SYS_MALLOC_SIMPLE 3522 Provides a simple and small malloc() and calloc() for those 3523 boards which do not use the full malloc in SPL (which is 3524 enabled with CONFIG_SYS_SPL_MALLOC_START). 3525 3526- CONFIG_SYS_NONCACHED_MEMORY: 3527 Size of non-cached memory area. This area of memory will be 3528 typically located right below the malloc() area and mapped 3529 uncached in the MMU. This is useful for drivers that would 3530 otherwise require a lot of explicit cache maintenance. For 3531 some drivers it's also impossible to properly maintain the 3532 cache. For example if the regions that need to be flushed 3533 are not a multiple of the cache-line size, *and* padding 3534 cannot be allocated between the regions to align them (i.e. 3535 if the HW requires a contiguous array of regions, and the 3536 size of each region is not cache-aligned), then a flush of 3537 one region may result in overwriting data that hardware has 3538 written to another region in the same cache-line. This can 3539 happen for example in network drivers where descriptors for 3540 buffers are typically smaller than the CPU cache-line (e.g. 3541 16 bytes vs. 32 or 64 bytes). 3542 3543 Non-cached memory is only supported on 32-bit ARM at present. 3544 3545- CONFIG_SYS_BOOTM_LEN: 3546 Normally compressed uImages are limited to an 3547 uncompressed size of 8 MBytes. If this is not enough, 3548 you can define CONFIG_SYS_BOOTM_LEN in your board config file 3549 to adjust this setting to your needs. 3550 3551- CONFIG_SYS_BOOTMAPSZ: 3552 Maximum size of memory mapped by the startup code of 3553 the Linux kernel; all data that must be processed by 3554 the Linux kernel (bd_info, boot arguments, FDT blob if 3555 used) must be put below this limit, unless "bootm_low" 3556 environment variable is defined and non-zero. In such case 3557 all data for the Linux kernel must be between "bootm_low" 3558 and "bootm_low" + CONFIG_SYS_BOOTMAPSZ. The environment 3559 variable "bootm_mapsize" will override the value of 3560 CONFIG_SYS_BOOTMAPSZ. If CONFIG_SYS_BOOTMAPSZ is undefined, 3561 then the value in "bootm_size" will be used instead. 3562 3563- CONFIG_SYS_BOOT_RAMDISK_HIGH: 3564 Enable initrd_high functionality. If defined then the 3565 initrd_high feature is enabled and the bootm ramdisk subcommand 3566 is enabled. 3567 3568- CONFIG_SYS_BOOT_GET_CMDLINE: 3569 Enables allocating and saving kernel cmdline in space between 3570 "bootm_low" and "bootm_low" + BOOTMAPSZ. 3571 3572- CONFIG_SYS_BOOT_GET_KBD: 3573 Enables allocating and saving a kernel copy of the bd_info in 3574 space between "bootm_low" and "bootm_low" + BOOTMAPSZ. 3575 3576- CONFIG_SYS_MAX_FLASH_BANKS: 3577 Max number of Flash memory banks 3578 3579- CONFIG_SYS_MAX_FLASH_SECT: 3580 Max number of sectors on a Flash chip 3581 3582- CONFIG_SYS_FLASH_ERASE_TOUT: 3583 Timeout for Flash erase operations (in ms) 3584 3585- CONFIG_SYS_FLASH_WRITE_TOUT: 3586 Timeout for Flash write operations (in ms) 3587 3588- CONFIG_SYS_FLASH_LOCK_TOUT 3589 Timeout for Flash set sector lock bit operation (in ms) 3590 3591- CONFIG_SYS_FLASH_UNLOCK_TOUT 3592 Timeout for Flash clear lock bits operation (in ms) 3593 3594- CONFIG_SYS_FLASH_PROTECTION 3595 If defined, hardware flash sectors protection is used 3596 instead of U-Boot software protection. 3597 3598- CONFIG_SYS_DIRECT_FLASH_TFTP: 3599 3600 Enable TFTP transfers directly to flash memory; 3601 without this option such a download has to be 3602 performed in two steps: (1) download to RAM, and (2) 3603 copy from RAM to flash. 3604 3605 The two-step approach is usually more reliable, since 3606 you can check if the download worked before you erase 3607 the flash, but in some situations (when system RAM is 3608 too limited to allow for a temporary copy of the 3609 downloaded image) this option may be very useful. 3610 3611- CONFIG_SYS_FLASH_CFI: 3612 Define if the flash driver uses extra elements in the 3613 common flash structure for storing flash geometry. 3614 3615- CONFIG_FLASH_CFI_DRIVER 3616 This option also enables the building of the cfi_flash driver 3617 in the drivers directory 3618 3619- CONFIG_FLASH_CFI_MTD 3620 This option enables the building of the cfi_mtd driver 3621 in the drivers directory. The driver exports CFI flash 3622 to the MTD layer. 3623 3624- CONFIG_SYS_FLASH_USE_BUFFER_WRITE 3625 Use buffered writes to flash. 3626 3627- CONFIG_FLASH_SPANSION_S29WS_N 3628 s29ws-n MirrorBit flash has non-standard addresses for buffered 3629 write commands. 3630 3631- CONFIG_SYS_FLASH_QUIET_TEST 3632 If this option is defined, the common CFI flash doesn't 3633 print it's warning upon not recognized FLASH banks. This 3634 is useful, if some of the configured banks are only 3635 optionally available. 3636 3637- CONFIG_FLASH_SHOW_PROGRESS 3638 If defined (must be an integer), print out countdown 3639 digits and dots. Recommended value: 45 (9..1) for 80 3640 column displays, 15 (3..1) for 40 column displays. 3641 3642- CONFIG_FLASH_VERIFY 3643 If defined, the content of the flash (destination) is compared 3644 against the source after the write operation. An error message 3645 will be printed when the contents are not identical. 3646 Please note that this option is useless in nearly all cases, 3647 since such flash programming errors usually are detected earlier 3648 while unprotecting/erasing/programming. Please only enable 3649 this option if you really know what you are doing. 3650 3651- CONFIG_SYS_RX_ETH_BUFFER: 3652 Defines the number of Ethernet receive buffers. On some 3653 Ethernet controllers it is recommended to set this value 3654 to 8 or even higher (EEPRO100 or 405 EMAC), since all 3655 buffers can be full shortly after enabling the interface 3656 on high Ethernet traffic. 3657 Defaults to 4 if not defined. 3658 3659- CONFIG_ENV_MAX_ENTRIES 3660 3661 Maximum number of entries in the hash table that is used 3662 internally to store the environment settings. The default 3663 setting is supposed to be generous and should work in most 3664 cases. This setting can be used to tune behaviour; see 3665 lib/hashtable.c for details. 3666 3667- CONFIG_ENV_FLAGS_LIST_DEFAULT 3668- CONFIG_ENV_FLAGS_LIST_STATIC 3669 Enable validation of the values given to environment variables when 3670 calling env set. Variables can be restricted to only decimal, 3671 hexadecimal, or boolean. If CONFIG_CMD_NET is also defined, 3672 the variables can also be restricted to IP address or MAC address. 3673 3674 The format of the list is: 3675 type_attribute = [s|d|x|b|i|m] 3676 access_attribute = [a|r|o|c] 3677 attributes = type_attribute[access_attribute] 3678 entry = variable_name[:attributes] 3679 list = entry[,list] 3680 3681 The type attributes are: 3682 s - String (default) 3683 d - Decimal 3684 x - Hexadecimal 3685 b - Boolean ([1yYtT|0nNfF]) 3686 i - IP address 3687 m - MAC address 3688 3689 The access attributes are: 3690 a - Any (default) 3691 r - Read-only 3692 o - Write-once 3693 c - Change-default 3694 3695 - CONFIG_ENV_FLAGS_LIST_DEFAULT 3696 Define this to a list (string) to define the ".flags" 3697 environment variable in the default or embedded environment. 3698 3699 - CONFIG_ENV_FLAGS_LIST_STATIC 3700 Define this to a list (string) to define validation that 3701 should be done if an entry is not found in the ".flags" 3702 environment variable. To override a setting in the static 3703 list, simply add an entry for the same variable name to the 3704 ".flags" variable. 3705 3706 If CONFIG_REGEX is defined, the variable_name above is evaluated as a 3707 regular expression. This allows multiple variables to define the same 3708 flags without explicitly listing them for each variable. 3709 3710- CONFIG_ENV_ACCESS_IGNORE_FORCE 3711 If defined, don't allow the -f switch to env set override variable 3712 access flags. 3713 3714- CONFIG_OMAP_PLATFORM_RESET_TIME_MAX_USEC (OMAP only) 3715 This is set by OMAP boards for the max time that reset should 3716 be asserted. See doc/README.omap-reset-time for details on how 3717 the value can be calculated on a given board. 3718 3719- CONFIG_USE_STDINT 3720 If stdint.h is available with your toolchain you can define this 3721 option to enable it. You can provide option 'USE_STDINT=1' when 3722 building U-Boot to enable this. 3723 3724The following definitions that deal with the placement and management 3725of environment data (variable area); in general, we support the 3726following configurations: 3727 3728- CONFIG_BUILD_ENVCRC: 3729 3730 Builds up envcrc with the target environment so that external utils 3731 may easily extract it and embed it in final U-Boot images. 3732 3733- CONFIG_ENV_IS_IN_FLASH: 3734 3735 Define this if the environment is in flash memory. 3736 3737 a) The environment occupies one whole flash sector, which is 3738 "embedded" in the text segment with the U-Boot code. This 3739 happens usually with "bottom boot sector" or "top boot 3740 sector" type flash chips, which have several smaller 3741 sectors at the start or the end. For instance, such a 3742 layout can have sector sizes of 8, 2x4, 16, Nx32 kB. In 3743 such a case you would place the environment in one of the 3744 4 kB sectors - with U-Boot code before and after it. With 3745 "top boot sector" type flash chips, you would put the 3746 environment in one of the last sectors, leaving a gap 3747 between U-Boot and the environment. 3748 3749 - CONFIG_ENV_OFFSET: 3750 3751 Offset of environment data (variable area) to the 3752 beginning of flash memory; for instance, with bottom boot 3753 type flash chips the second sector can be used: the offset 3754 for this sector is given here. 3755 3756 CONFIG_ENV_OFFSET is used relative to CONFIG_SYS_FLASH_BASE. 3757 3758 - CONFIG_ENV_ADDR: 3759 3760 This is just another way to specify the start address of 3761 the flash sector containing the environment (instead of 3762 CONFIG_ENV_OFFSET). 3763 3764 - CONFIG_ENV_SECT_SIZE: 3765 3766 Size of the sector containing the environment. 3767 3768 3769 b) Sometimes flash chips have few, equal sized, BIG sectors. 3770 In such a case you don't want to spend a whole sector for 3771 the environment. 3772 3773 - CONFIG_ENV_SIZE: 3774 3775 If you use this in combination with CONFIG_ENV_IS_IN_FLASH 3776 and CONFIG_ENV_SECT_SIZE, you can specify to use only a part 3777 of this flash sector for the environment. This saves 3778 memory for the RAM copy of the environment. 3779 3780 It may also save flash memory if you decide to use this 3781 when your environment is "embedded" within U-Boot code, 3782 since then the remainder of the flash sector could be used 3783 for U-Boot code. It should be pointed out that this is 3784 STRONGLY DISCOURAGED from a robustness point of view: 3785 updating the environment in flash makes it always 3786 necessary to erase the WHOLE sector. If something goes 3787 wrong before the contents has been restored from a copy in 3788 RAM, your target system will be dead. 3789 3790 - CONFIG_ENV_ADDR_REDUND 3791 CONFIG_ENV_SIZE_REDUND 3792 3793 These settings describe a second storage area used to hold 3794 a redundant copy of the environment data, so that there is 3795 a valid backup copy in case there is a power failure during 3796 a "saveenv" operation. 3797 3798BE CAREFUL! Any changes to the flash layout, and some changes to the 3799source code will make it necessary to adapt <board>/u-boot.lds* 3800accordingly! 3801 3802 3803- CONFIG_ENV_IS_IN_NVRAM: 3804 3805 Define this if you have some non-volatile memory device 3806 (NVRAM, battery buffered SRAM) which you want to use for the 3807 environment. 3808 3809 - CONFIG_ENV_ADDR: 3810 - CONFIG_ENV_SIZE: 3811 3812 These two #defines are used to determine the memory area you 3813 want to use for environment. It is assumed that this memory 3814 can just be read and written to, without any special 3815 provision. 3816 3817BE CAREFUL! The first access to the environment happens quite early 3818in U-Boot initialization (when we try to get the setting of for the 3819console baudrate). You *MUST* have mapped your NVRAM area then, or 3820U-Boot will hang. 3821 3822Please note that even with NVRAM we still use a copy of the 3823environment in RAM: we could work on NVRAM directly, but we want to 3824keep settings there always unmodified except somebody uses "saveenv" 3825to save the current settings. 3826 3827 3828- CONFIG_ENV_IS_IN_EEPROM: 3829 3830 Use this if you have an EEPROM or similar serial access 3831 device and a driver for it. 3832 3833 - CONFIG_ENV_OFFSET: 3834 - CONFIG_ENV_SIZE: 3835 3836 These two #defines specify the offset and size of the 3837 environment area within the total memory of your EEPROM. 3838 3839 - CONFIG_SYS_I2C_EEPROM_ADDR: 3840 If defined, specified the chip address of the EEPROM device. 3841 The default address is zero. 3842 3843 - CONFIG_SYS_I2C_EEPROM_BUS: 3844 If defined, specified the i2c bus of the EEPROM device. 3845 3846 - CONFIG_SYS_EEPROM_PAGE_WRITE_BITS: 3847 If defined, the number of bits used to address bytes in a 3848 single page in the EEPROM device. A 64 byte page, for example 3849 would require six bits. 3850 3851 - CONFIG_SYS_EEPROM_PAGE_WRITE_DELAY_MS: 3852 If defined, the number of milliseconds to delay between 3853 page writes. The default is zero milliseconds. 3854 3855 - CONFIG_SYS_I2C_EEPROM_ADDR_LEN: 3856 The length in bytes of the EEPROM memory array address. Note 3857 that this is NOT the chip address length! 3858 3859 - CONFIG_SYS_I2C_EEPROM_ADDR_OVERFLOW: 3860 EEPROM chips that implement "address overflow" are ones 3861 like Catalyst 24WC04/08/16 which has 9/10/11 bits of 3862 address and the extra bits end up in the "chip address" bit 3863 slots. This makes a 24WC08 (1Kbyte) chip look like four 256 3864 byte chips. 3865 3866 Note that we consider the length of the address field to 3867 still be one byte because the extra address bits are hidden 3868 in the chip address. 3869 3870 - CONFIG_SYS_EEPROM_SIZE: 3871 The size in bytes of the EEPROM device. 3872 3873 - CONFIG_ENV_EEPROM_IS_ON_I2C 3874 define this, if you have I2C and SPI activated, and your 3875 EEPROM, which holds the environment, is on the I2C bus. 3876 3877 - CONFIG_I2C_ENV_EEPROM_BUS 3878 if you have an Environment on an EEPROM reached over 3879 I2C muxes, you can define here, how to reach this 3880 EEPROM. For example: 3881 3882 #define CONFIG_I2C_ENV_EEPROM_BUS 1 3883 3884 EEPROM which holds the environment, is reached over 3885 a pca9547 i2c mux with address 0x70, channel 3. 3886 3887- CONFIG_ENV_IS_IN_DATAFLASH: 3888 3889 Define this if you have a DataFlash memory device which you 3890 want to use for the environment. 3891 3892 - CONFIG_ENV_OFFSET: 3893 - CONFIG_ENV_ADDR: 3894 - CONFIG_ENV_SIZE: 3895 3896 These three #defines specify the offset and size of the 3897 environment area within the total memory of your DataFlash placed 3898 at the specified address. 3899 3900- CONFIG_ENV_IS_IN_SPI_FLASH: 3901 3902 Define this if you have a SPI Flash memory device which you 3903 want to use for the environment. 3904 3905 - CONFIG_ENV_OFFSET: 3906 - CONFIG_ENV_SIZE: 3907 3908 These two #defines specify the offset and size of the 3909 environment area within the SPI Flash. CONFIG_ENV_OFFSET must be 3910 aligned to an erase sector boundary. 3911 3912 - CONFIG_ENV_SECT_SIZE: 3913 3914 Define the SPI flash's sector size. 3915 3916 - CONFIG_ENV_OFFSET_REDUND (optional): 3917 3918 This setting describes a second storage area of CONFIG_ENV_SIZE 3919 size used to hold a redundant copy of the environment data, so 3920 that there is a valid backup copy in case there is a power failure 3921 during a "saveenv" operation. CONFIG_ENV_OFFSET_REDUND must be 3922 aligned to an erase sector boundary. 3923 3924 - CONFIG_ENV_SPI_BUS (optional): 3925 - CONFIG_ENV_SPI_CS (optional): 3926 3927 Define the SPI bus and chip select. If not defined they will be 0. 3928 3929 - CONFIG_ENV_SPI_MAX_HZ (optional): 3930 3931 Define the SPI max work clock. If not defined then use 1MHz. 3932 3933 - CONFIG_ENV_SPI_MODE (optional): 3934 3935 Define the SPI work mode. If not defined then use SPI_MODE_3. 3936 3937- CONFIG_ENV_IS_IN_REMOTE: 3938 3939 Define this if you have a remote memory space which you 3940 want to use for the local device's environment. 3941 3942 - CONFIG_ENV_ADDR: 3943 - CONFIG_ENV_SIZE: 3944 3945 These two #defines specify the address and size of the 3946 environment area within the remote memory space. The 3947 local device can get the environment from remote memory 3948 space by SRIO or PCIE links. 3949 3950BE CAREFUL! For some special cases, the local device can not use 3951"saveenv" command. For example, the local device will get the 3952environment stored in a remote NOR flash by SRIO or PCIE link, 3953but it can not erase, write this NOR flash by SRIO or PCIE interface. 3954 3955- CONFIG_ENV_IS_IN_NAND: 3956 3957 Define this if you have a NAND device which you want to use 3958 for the environment. 3959 3960 - CONFIG_ENV_OFFSET: 3961 - CONFIG_ENV_SIZE: 3962 3963 These two #defines specify the offset and size of the environment 3964 area within the first NAND device. CONFIG_ENV_OFFSET must be 3965 aligned to an erase block boundary. 3966 3967 - CONFIG_ENV_OFFSET_REDUND (optional): 3968 3969 This setting describes a second storage area of CONFIG_ENV_SIZE 3970 size used to hold a redundant copy of the environment data, so 3971 that there is a valid backup copy in case there is a power failure 3972 during a "saveenv" operation. CONFIG_ENV_OFFSET_REDUND must be 3973 aligned to an erase block boundary. 3974 3975 - CONFIG_ENV_RANGE (optional): 3976 3977 Specifies the length of the region in which the environment 3978 can be written. This should be a multiple of the NAND device's 3979 block size. Specifying a range with more erase blocks than 3980 are needed to hold CONFIG_ENV_SIZE allows bad blocks within 3981 the range to be avoided. 3982 3983 - CONFIG_ENV_OFFSET_OOB (optional): 3984 3985 Enables support for dynamically retrieving the offset of the 3986 environment from block zero's out-of-band data. The 3987 "nand env.oob" command can be used to record this offset. 3988 Currently, CONFIG_ENV_OFFSET_REDUND is not supported when 3989 using CONFIG_ENV_OFFSET_OOB. 3990 3991- CONFIG_NAND_ENV_DST 3992 3993 Defines address in RAM to which the nand_spl code should copy the 3994 environment. If redundant environment is used, it will be copied to 3995 CONFIG_NAND_ENV_DST + CONFIG_ENV_SIZE. 3996 3997- CONFIG_ENV_IS_IN_UBI: 3998 3999 Define this if you have an UBI volume that you want to use for the 4000 environment. This has the benefit of wear-leveling the environment 4001 accesses, which is important on NAND. 4002 4003 - CONFIG_ENV_UBI_PART: 4004 4005 Define this to a string that is the mtd partition containing the UBI. 4006 4007 - CONFIG_ENV_UBI_VOLUME: 4008 4009 Define this to the name of the volume that you want to store the 4010 environment in. 4011 4012 - CONFIG_ENV_UBI_VOLUME_REDUND: 4013 4014 Define this to the name of another volume to store a second copy of 4015 the environment in. This will enable redundant environments in UBI. 4016 It is assumed that both volumes are in the same MTD partition. 4017 4018 - CONFIG_UBI_SILENCE_MSG 4019 - CONFIG_UBIFS_SILENCE_MSG 4020 4021 You will probably want to define these to avoid a really noisy system 4022 when storing the env in UBI. 4023 4024- CONFIG_ENV_IS_IN_FAT: 4025 Define this if you want to use the FAT file system for the environment. 4026 4027 - FAT_ENV_INTERFACE: 4028 4029 Define this to a string that is the name of the block device. 4030 4031 - FAT_ENV_DEVICE_AND_PART: 4032 4033 Define this to a string to specify the partition of the device. It can 4034 be as following: 4035 4036 "D:P", "D:0", "D", "D:" or "D:auto" (D, P are integers. And P >= 1) 4037 - "D:P": device D partition P. Error occurs if device D has no 4038 partition table. 4039 - "D:0": device D. 4040 - "D" or "D:": device D partition 1 if device D has partition 4041 table, or the whole device D if has no partition 4042 table. 4043 - "D:auto": first partition in device D with bootable flag set. 4044 If none, first valid partition in device D. If no 4045 partition table then means device D. 4046 4047 - FAT_ENV_FILE: 4048 4049 It's a string of the FAT file name. This file use to store the 4050 environment. 4051 4052 - CONFIG_FAT_WRITE: 4053 This should be defined. Otherwise it cannot save the environment file. 4054 4055- CONFIG_ENV_IS_IN_MMC: 4056 4057 Define this if you have an MMC device which you want to use for the 4058 environment. 4059 4060 - CONFIG_SYS_MMC_ENV_DEV: 4061 4062 Specifies which MMC device the environment is stored in. 4063 4064 - CONFIG_SYS_MMC_ENV_PART (optional): 4065 4066 Specifies which MMC partition the environment is stored in. If not 4067 set, defaults to partition 0, the user area. Common values might be 4068 1 (first MMC boot partition), 2 (second MMC boot partition). 4069 4070 - CONFIG_ENV_OFFSET: 4071 - CONFIG_ENV_SIZE: 4072 4073 These two #defines specify the offset and size of the environment 4074 area within the specified MMC device. 4075 4076 If offset is positive (the usual case), it is treated as relative to 4077 the start of the MMC partition. If offset is negative, it is treated 4078 as relative to the end of the MMC partition. This can be useful if 4079 your board may be fitted with different MMC devices, which have 4080 different sizes for the MMC partitions, and you always want the 4081 environment placed at the very end of the partition, to leave the 4082 maximum possible space before it, to store other data. 4083 4084 These two values are in units of bytes, but must be aligned to an 4085 MMC sector boundary. 4086 4087 - CONFIG_ENV_OFFSET_REDUND (optional): 4088 4089 Specifies a second storage area, of CONFIG_ENV_SIZE size, used to 4090 hold a redundant copy of the environment data. This provides a 4091 valid backup copy in case the other copy is corrupted, e.g. due 4092 to a power failure during a "saveenv" operation. 4093 4094 This value may also be positive or negative; this is handled in the 4095 same way as CONFIG_ENV_OFFSET. 4096 4097 This value is also in units of bytes, but must also be aligned to 4098 an MMC sector boundary. 4099 4100 - CONFIG_ENV_SIZE_REDUND (optional): 4101 4102 This value need not be set, even when CONFIG_ENV_OFFSET_REDUND is 4103 set. If this value is set, it must be set to the same value as 4104 CONFIG_ENV_SIZE. 4105 4106- CONFIG_SYS_SPI_INIT_OFFSET 4107 4108 Defines offset to the initial SPI buffer area in DPRAM. The 4109 area is used at an early stage (ROM part) if the environment 4110 is configured to reside in the SPI EEPROM: We need a 520 byte 4111 scratch DPRAM area. It is used between the two initialization 4112 calls (spi_init_f() and spi_init_r()). A value of 0xB00 seems 4113 to be a good choice since it makes it far enough from the 4114 start of the data area as well as from the stack pointer. 4115 4116Please note that the environment is read-only until the monitor 4117has been relocated to RAM and a RAM copy of the environment has been 4118created; also, when using EEPROM you will have to use getenv_f() 4119until then to read environment variables. 4120 4121The environment is protected by a CRC32 checksum. Before the monitor 4122is relocated into RAM, as a result of a bad CRC you will be working 4123with the compiled-in default environment - *silently*!!! [This is 4124necessary, because the first environment variable we need is the 4125"baudrate" setting for the console - if we have a bad CRC, we don't 4126have any device yet where we could complain.] 4127 4128Note: once the monitor has been relocated, then it will complain if 4129the default environment is used; a new CRC is computed as soon as you 4130use the "saveenv" command to store a valid environment. 4131 4132- CONFIG_SYS_FAULT_ECHO_LINK_DOWN: 4133 Echo the inverted Ethernet link state to the fault LED. 4134 4135 Note: If this option is active, then CONFIG_SYS_FAULT_MII_ADDR 4136 also needs to be defined. 4137 4138- CONFIG_SYS_FAULT_MII_ADDR: 4139 MII address of the PHY to check for the Ethernet link state. 4140 4141- CONFIG_NS16550_MIN_FUNCTIONS: 4142 Define this if you desire to only have use of the NS16550_init 4143 and NS16550_putc functions for the serial driver located at 4144 drivers/serial/ns16550.c. This option is useful for saving 4145 space for already greatly restricted images, including but not 4146 limited to NAND_SPL configurations. 4147 4148- CONFIG_DISPLAY_BOARDINFO 4149 Display information about the board that U-Boot is running on 4150 when U-Boot starts up. The board function checkboard() is called 4151 to do this. 4152 4153- CONFIG_DISPLAY_BOARDINFO_LATE 4154 Similar to the previous option, but display this information 4155 later, once stdio is running and output goes to the LCD, if 4156 present. 4157 4158- CONFIG_BOARD_SIZE_LIMIT: 4159 Maximum size of the U-Boot image. When defined, the 4160 build system checks that the actual size does not 4161 exceed it. 4162 4163Low Level (hardware related) configuration options: 4164--------------------------------------------------- 4165 4166- CONFIG_SYS_CACHELINE_SIZE: 4167 Cache Line Size of the CPU. 4168 4169- CONFIG_SYS_DEFAULT_IMMR: 4170 Default address of the IMMR after system reset. 4171 4172 Needed on some 8260 systems (MPC8260ADS, PQ2FADS-ZU, 4173 and RPXsuper) to be able to adjust the position of 4174 the IMMR register after a reset. 4175 4176- CONFIG_SYS_CCSRBAR_DEFAULT: 4177 Default (power-on reset) physical address of CCSR on Freescale 4178 PowerPC SOCs. 4179 4180- CONFIG_SYS_CCSRBAR: 4181 Virtual address of CCSR. On a 32-bit build, this is typically 4182 the same value as CONFIG_SYS_CCSRBAR_DEFAULT. 4183 4184 CONFIG_SYS_DEFAULT_IMMR must also be set to this value, 4185 for cross-platform code that uses that macro instead. 4186 4187- CONFIG_SYS_CCSRBAR_PHYS: 4188 Physical address of CCSR. CCSR can be relocated to a new 4189 physical address, if desired. In this case, this macro should 4190 be set to that address. Otherwise, it should be set to the 4191 same value as CONFIG_SYS_CCSRBAR_DEFAULT. For example, CCSR 4192 is typically relocated on 36-bit builds. It is recommended 4193 that this macro be defined via the _HIGH and _LOW macros: 4194 4195 #define CONFIG_SYS_CCSRBAR_PHYS ((CONFIG_SYS_CCSRBAR_PHYS_HIGH 4196 * 1ull) << 32 | CONFIG_SYS_CCSRBAR_PHYS_LOW) 4197 4198- CONFIG_SYS_CCSRBAR_PHYS_HIGH: 4199 Bits 33-36 of CONFIG_SYS_CCSRBAR_PHYS. This value is typically 4200 either 0 (32-bit build) or 0xF (36-bit build). This macro is 4201 used in assembly code, so it must not contain typecasts or 4202 integer size suffixes (e.g. "ULL"). 4203 4204- CONFIG_SYS_CCSRBAR_PHYS_LOW: 4205 Lower 32-bits of CONFIG_SYS_CCSRBAR_PHYS. 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_CCSR_DO_NOT_RELOCATE: 4210 If this macro is defined, then CONFIG_SYS_CCSRBAR_PHYS will be 4211 forced to a value that ensures that CCSR is not relocated. 4212 4213- Floppy Disk Support: 4214 CONFIG_SYS_FDC_DRIVE_NUMBER 4215 4216 the default drive number (default value 0) 4217 4218 CONFIG_SYS_ISA_IO_STRIDE 4219 4220 defines the spacing between FDC chipset registers 4221 (default value 1) 4222 4223 CONFIG_SYS_ISA_IO_OFFSET 4224 4225 defines the offset of register from address. It 4226 depends on which part of the data bus is connected to 4227 the FDC chipset. (default value 0) 4228 4229 If CONFIG_SYS_ISA_IO_STRIDE CONFIG_SYS_ISA_IO_OFFSET and 4230 CONFIG_SYS_FDC_DRIVE_NUMBER are undefined, they take their 4231 default value. 4232 4233 if CONFIG_SYS_FDC_HW_INIT is defined, then the function 4234 fdc_hw_init() is called at the beginning of the FDC 4235 setup. fdc_hw_init() must be provided by the board 4236 source code. It is used to make hardware-dependent 4237 initializations. 4238 4239- CONFIG_IDE_AHB: 4240 Most IDE controllers were designed to be connected with PCI 4241 interface. Only few of them were designed for AHB interface. 4242 When software is doing ATA command and data transfer to 4243 IDE devices through IDE-AHB controller, some additional 4244 registers accessing to these kind of IDE-AHB controller 4245 is required. 4246 4247- CONFIG_SYS_IMMR: Physical address of the Internal Memory. 4248 DO NOT CHANGE unless you know exactly what you're 4249 doing! (11-4) [MPC8xx/82xx systems only] 4250 4251- CONFIG_SYS_INIT_RAM_ADDR: 4252 4253 Start address of memory area that can be used for 4254 initial data and stack; please note that this must be 4255 writable memory that is working WITHOUT special 4256 initialization, i. e. you CANNOT use normal RAM which 4257 will become available only after programming the 4258 memory controller and running certain initialization 4259 sequences. 4260 4261 U-Boot uses the following memory types: 4262 - MPC8xx and MPC8260: IMMR (internal memory of the CPU) 4263 - MPC824X: data cache 4264 - PPC4xx: data cache 4265 4266- CONFIG_SYS_GBL_DATA_OFFSET: 4267 4268 Offset of the initial data structure in the memory 4269 area defined by CONFIG_SYS_INIT_RAM_ADDR. Usually 4270 CONFIG_SYS_GBL_DATA_OFFSET is chosen such that the initial 4271 data is located at the end of the available space 4272 (sometimes written as (CONFIG_SYS_INIT_RAM_SIZE - 4273 GENERATED_GBL_DATA_SIZE), and the initial stack is just 4274 below that area (growing from (CONFIG_SYS_INIT_RAM_ADDR + 4275 CONFIG_SYS_GBL_DATA_OFFSET) downward. 4276 4277 Note: 4278 On the MPC824X (or other systems that use the data 4279 cache for initial memory) the address chosen for 4280 CONFIG_SYS_INIT_RAM_ADDR is basically arbitrary - it must 4281 point to an otherwise UNUSED address space between 4282 the top of RAM and the start of the PCI space. 4283 4284- CONFIG_SYS_SIUMCR: SIU Module Configuration (11-6) 4285 4286- CONFIG_SYS_SYPCR: System Protection Control (11-9) 4287 4288- CONFIG_SYS_TBSCR: Time Base Status and Control (11-26) 4289 4290- CONFIG_SYS_PISCR: Periodic Interrupt Status and Control (11-31) 4291 4292- CONFIG_SYS_PLPRCR: PLL, Low-Power, and Reset Control Register (15-30) 4293 4294- CONFIG_SYS_SCCR: System Clock and reset Control Register (15-27) 4295 4296- CONFIG_SYS_OR_TIMING_SDRAM: 4297 SDRAM timing 4298 4299- CONFIG_SYS_MAMR_PTA: 4300 periodic timer for refresh 4301 4302- CONFIG_SYS_DER: Debug Event Register (37-47) 4303 4304- FLASH_BASE0_PRELIM, FLASH_BASE1_PRELIM, CONFIG_SYS_REMAP_OR_AM, 4305 CONFIG_SYS_PRELIM_OR_AM, CONFIG_SYS_OR_TIMING_FLASH, CONFIG_SYS_OR0_REMAP, 4306 CONFIG_SYS_OR0_PRELIM, CONFIG_SYS_BR0_PRELIM, CONFIG_SYS_OR1_REMAP, CONFIG_SYS_OR1_PRELIM, 4307 CONFIG_SYS_BR1_PRELIM: 4308 Memory Controller Definitions: BR0/1 and OR0/1 (FLASH) 4309 4310- SDRAM_BASE2_PRELIM, SDRAM_BASE3_PRELIM, SDRAM_MAX_SIZE, 4311 CONFIG_SYS_OR_TIMING_SDRAM, CONFIG_SYS_OR2_PRELIM, CONFIG_SYS_BR2_PRELIM, 4312 CONFIG_SYS_OR3_PRELIM, CONFIG_SYS_BR3_PRELIM: 4313 Memory Controller Definitions: BR2/3 and OR2/3 (SDRAM) 4314 4315- CONFIG_SYS_MAMR_PTA, CONFIG_SYS_MPTPR_2BK_4K, CONFIG_SYS_MPTPR_1BK_4K, CONFIG_SYS_MPTPR_2BK_8K, 4316 CONFIG_SYS_MPTPR_1BK_8K, CONFIG_SYS_MAMR_8COL, CONFIG_SYS_MAMR_9COL: 4317 Machine Mode Register and Memory Periodic Timer 4318 Prescaler definitions (SDRAM timing) 4319 4320- CONFIG_SYS_I2C_UCODE_PATCH, CONFIG_SYS_I2C_DPMEM_OFFSET [0x1FC0]: 4321 enable I2C microcode relocation patch (MPC8xx); 4322 define relocation offset in DPRAM [DSP2] 4323 4324- CONFIG_SYS_SMC_UCODE_PATCH, CONFIG_SYS_SMC_DPMEM_OFFSET [0x1FC0]: 4325 enable SMC microcode relocation patch (MPC8xx); 4326 define relocation offset in DPRAM [SMC1] 4327 4328- CONFIG_SYS_SPI_UCODE_PATCH, CONFIG_SYS_SPI_DPMEM_OFFSET [0x1FC0]: 4329 enable SPI microcode relocation patch (MPC8xx); 4330 define relocation offset in DPRAM [SCC4] 4331 4332- CONFIG_SYS_CPM_POST_WORD_ADDR: (MPC8xx, MPC8260 only) 4333 Offset of the bootmode word in DPRAM used by post 4334 (Power On Self Tests). This definition overrides 4335 #define'd default value in commproc.h resp. 4336 cpm_8260.h. 4337 4338- CONFIG_SYS_PCI_SLV_MEM_LOCAL, CONFIG_SYS_PCI_SLV_MEM_BUS, CONFIG_SYS_PICMR0_MASK_ATTRIB, 4339 CONFIG_SYS_PCI_MSTR0_LOCAL, CONFIG_SYS_PCIMSK0_MASK, CONFIG_SYS_PCI_MSTR1_LOCAL, 4340 CONFIG_SYS_PCIMSK1_MASK, CONFIG_SYS_PCI_MSTR_MEM_LOCAL, CONFIG_SYS_PCI_MSTR_MEM_BUS, 4341 CONFIG_SYS_CPU_PCI_MEM_START, CONFIG_SYS_PCI_MSTR_MEM_SIZE, CONFIG_SYS_POCMR0_MASK_ATTRIB, 4342 CONFIG_SYS_PCI_MSTR_MEMIO_LOCAL, CONFIG_SYS_PCI_MSTR_MEMIO_BUS, CPU_PCI_MEMIO_START, 4343 CONFIG_SYS_PCI_MSTR_MEMIO_SIZE, CONFIG_SYS_POCMR1_MASK_ATTRIB, CONFIG_SYS_PCI_MSTR_IO_LOCAL, 4344 CONFIG_SYS_PCI_MSTR_IO_BUS, CONFIG_SYS_CPU_PCI_IO_START, CONFIG_SYS_PCI_MSTR_IO_SIZE, 4345 CONFIG_SYS_POCMR2_MASK_ATTRIB: (MPC826x only) 4346 Overrides the default PCI memory map in arch/powerpc/cpu/mpc8260/pci.c if set. 4347 4348- CONFIG_PCI_DISABLE_PCIE: 4349 Disable PCI-Express on systems where it is supported but not 4350 required. 4351 4352- CONFIG_PCI_ENUM_ONLY 4353 Only scan through and get the devices on the buses. 4354 Don't do any setup work, presumably because someone or 4355 something has already done it, and we don't need to do it 4356 a second time. Useful for platforms that are pre-booted 4357 by coreboot or similar. 4358 4359- CONFIG_PCI_INDIRECT_BRIDGE: 4360 Enable support for indirect PCI bridges. 4361 4362- CONFIG_SYS_SRIO: 4363 Chip has SRIO or not 4364 4365- CONFIG_SRIO1: 4366 Board has SRIO 1 port available 4367 4368- CONFIG_SRIO2: 4369 Board has SRIO 2 port available 4370 4371- CONFIG_SRIO_PCIE_BOOT_MASTER 4372 Board can support master function for Boot from SRIO and PCIE 4373 4374- CONFIG_SYS_SRIOn_MEM_VIRT: 4375 Virtual Address of SRIO port 'n' memory region 4376 4377- CONFIG_SYS_SRIOn_MEM_PHYS: 4378 Physical Address of SRIO port 'n' memory region 4379 4380- CONFIG_SYS_SRIOn_MEM_SIZE: 4381 Size of SRIO port 'n' memory region 4382 4383- CONFIG_SYS_NAND_BUSWIDTH_16BIT 4384 Defined to tell the NAND controller that the NAND chip is using 4385 a 16 bit bus. 4386 Not all NAND drivers use this symbol. 4387 Example of drivers that use it: 4388 - drivers/mtd/nand/ndfc.c 4389 - drivers/mtd/nand/mxc_nand.c 4390 4391- CONFIG_SYS_NDFC_EBC0_CFG 4392 Sets the EBC0_CFG register for the NDFC. If not defined 4393 a default value will be used. 4394 4395- CONFIG_SPD_EEPROM 4396 Get DDR timing information from an I2C EEPROM. Common 4397 with pluggable memory modules such as SODIMMs 4398 4399 SPD_EEPROM_ADDRESS 4400 I2C address of the SPD EEPROM 4401 4402- CONFIG_SYS_SPD_BUS_NUM 4403 If SPD EEPROM is on an I2C bus other than the first 4404 one, specify here. Note that the value must resolve 4405 to something your driver can deal with. 4406 4407- CONFIG_SYS_DDR_RAW_TIMING 4408 Get DDR timing information from other than SPD. Common with 4409 soldered DDR chips onboard without SPD. DDR raw timing 4410 parameters are extracted from datasheet and hard-coded into 4411 header files or board specific files. 4412 4413- CONFIG_FSL_DDR_INTERACTIVE 4414 Enable interactive DDR debugging. See doc/README.fsl-ddr. 4415 4416- CONFIG_FSL_DDR_SYNC_REFRESH 4417 Enable sync of refresh for multiple controllers. 4418 4419- CONFIG_FSL_DDR_BIST 4420 Enable built-in memory test for Freescale DDR controllers. 4421 4422- CONFIG_SYS_83XX_DDR_USES_CS0 4423 Only for 83xx systems. If specified, then DDR should 4424 be configured using CS0 and CS1 instead of CS2 and CS3. 4425 4426- CONFIG_ETHER_ON_FEC[12] 4427 Define to enable FEC[12] on a 8xx series processor. 4428 4429- CONFIG_FEC[12]_PHY 4430 Define to the hardcoded PHY address which corresponds 4431 to the given FEC; i. e. 4432 #define CONFIG_FEC1_PHY 4 4433 means that the PHY with address 4 is connected to FEC1 4434 4435 When set to -1, means to probe for first available. 4436 4437- CONFIG_FEC[12]_PHY_NORXERR 4438 The PHY does not have a RXERR line (RMII only). 4439 (so program the FEC to ignore it). 4440 4441- CONFIG_RMII 4442 Enable RMII mode for all FECs. 4443 Note that this is a global option, we can't 4444 have one FEC in standard MII mode and another in RMII mode. 4445 4446- CONFIG_CRC32_VERIFY 4447 Add a verify option to the crc32 command. 4448 The syntax is: 4449 4450 => crc32 -v <address> <count> <crc32> 4451 4452 Where address/count indicate a memory area 4453 and crc32 is the correct crc32 which the 4454 area should have. 4455 4456- CONFIG_LOOPW 4457 Add the "loopw" memory command. This only takes effect if 4458 the memory commands are activated globally (CONFIG_CMD_MEM). 4459 4460- CONFIG_MX_CYCLIC 4461 Add the "mdc" and "mwc" memory commands. These are cyclic 4462 "md/mw" commands. 4463 Examples: 4464 4465 => mdc.b 10 4 500 4466 This command will print 4 bytes (10,11,12,13) each 500 ms. 4467 4468 => mwc.l 100 12345678 10 4469 This command will write 12345678 to address 100 all 10 ms. 4470 4471 This only takes effect if the memory commands are activated 4472 globally (CONFIG_CMD_MEM). 4473 4474- CONFIG_SKIP_LOWLEVEL_INIT 4475 [ARM, NDS32, MIPS only] If this variable is defined, then certain 4476 low level initializations (like setting up the memory 4477 controller) are omitted and/or U-Boot does not 4478 relocate itself into RAM. 4479 4480 Normally this variable MUST NOT be defined. The only 4481 exception is when U-Boot is loaded (to RAM) by some 4482 other boot loader or by a debugger which performs 4483 these initializations itself. 4484 4485- CONFIG_SKIP_LOWLEVEL_INIT_ONLY 4486 [ARM926EJ-S only] This allows just the call to lowlevel_init() 4487 to be skipped. The normal CP15 init (such as enabling the 4488 instruction cache) is still performed. 4489 4490- CONFIG_SPL_BUILD 4491 Modifies the behaviour of start.S when compiling a loader 4492 that is executed before the actual U-Boot. E.g. when 4493 compiling a NAND SPL. 4494 4495- CONFIG_TPL_BUILD 4496 Modifies the behaviour of start.S when compiling a loader 4497 that is executed after the SPL and before the actual U-Boot. 4498 It is loaded by the SPL. 4499 4500- CONFIG_SYS_MPC85XX_NO_RESETVEC 4501 Only for 85xx systems. If this variable is specified, the section 4502 .resetvec is not kept and the section .bootpg is placed in the 4503 previous 4k of the .text section. 4504 4505- CONFIG_ARCH_MAP_SYSMEM 4506 Generally U-Boot (and in particular the md command) uses 4507 effective address. It is therefore not necessary to regard 4508 U-Boot address as virtual addresses that need to be translated 4509 to physical addresses. However, sandbox requires this, since 4510 it maintains its own little RAM buffer which contains all 4511 addressable memory. This option causes some memory accesses 4512 to be mapped through map_sysmem() / unmap_sysmem(). 4513 4514- CONFIG_X86_RESET_VECTOR 4515 If defined, the x86 reset vector code is included. This is not 4516 needed when U-Boot is running from Coreboot. 4517 4518- CONFIG_SYS_MPUCLK 4519 Defines the MPU clock speed (in MHz). 4520 4521 NOTE : currently only supported on AM335x platforms. 4522 4523- CONFIG_SPL_AM33XX_ENABLE_RTC32K_OSC: 4524 Enables the RTC32K OSC on AM33xx based plattforms 4525 4526- CONFIG_SYS_NAND_NO_SUBPAGE_WRITE 4527 Option to disable subpage write in NAND driver 4528 driver that uses this: 4529 drivers/mtd/nand/davinci_nand.c 4530 4531Freescale QE/FMAN Firmware Support: 4532----------------------------------- 4533 4534The Freescale QUICCEngine (QE) and Frame Manager (FMAN) both support the 4535loading of "firmware", which is encoded in the QE firmware binary format. 4536This firmware often needs to be loaded during U-Boot booting, so macros 4537are used to identify the storage device (NOR flash, SPI, etc) and the address 4538within that device. 4539 4540- CONFIG_SYS_FMAN_FW_ADDR 4541 The address in the storage device where the FMAN microcode is located. The 4542 meaning of this address depends on which CONFIG_SYS_QE_FW_IN_xxx macro 4543 is also specified. 4544 4545- CONFIG_SYS_QE_FW_ADDR 4546 The address in the storage device where the QE 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_FMAN_FW_LENGTH 4551 The maximum possible size of the firmware. The firmware binary format 4552 has a field that specifies the actual size of the firmware, but it 4553 might not be possible to read any part of the firmware unless some 4554 local storage is allocated to hold the entire firmware first. 4555 4556- CONFIG_SYS_QE_FMAN_FW_IN_NOR 4557 Specifies that QE/FMAN firmware is located in NOR flash, mapped as 4558 normal addressable memory via the LBC. CONFIG_SYS_FMAN_FW_ADDR is the 4559 virtual address in NOR flash. 4560 4561- CONFIG_SYS_QE_FMAN_FW_IN_NAND 4562 Specifies that QE/FMAN firmware is located in NAND flash. 4563 CONFIG_SYS_FMAN_FW_ADDR is the offset within NAND flash. 4564 4565- CONFIG_SYS_QE_FMAN_FW_IN_MMC 4566 Specifies that QE/FMAN firmware is located on the primary SD/MMC 4567 device. CONFIG_SYS_FMAN_FW_ADDR is the byte offset on that device. 4568 4569- CONFIG_SYS_QE_FMAN_FW_IN_REMOTE 4570 Specifies that QE/FMAN firmware is located in the remote (master) 4571 memory space. CONFIG_SYS_FMAN_FW_ADDR is a virtual address which 4572 can be mapped from slave TLB->slave LAW->slave SRIO or PCIE outbound 4573 window->master inbound window->master LAW->the ucode address in 4574 master's memory space. 4575 4576Freescale Layerscape Management Complex Firmware Support: 4577--------------------------------------------------------- 4578The Freescale Layerscape Management Complex (MC) supports the loading of 4579"firmware". 4580This firmware often needs to be loaded during U-Boot booting, so macros 4581are used to identify the storage device (NOR flash, SPI, etc) and the address 4582within that device. 4583 4584- CONFIG_FSL_MC_ENET 4585 Enable the MC driver for Layerscape SoCs. 4586 4587Freescale Layerscape Debug Server Support: 4588------------------------------------------- 4589The Freescale Layerscape Debug Server Support supports the loading of 4590"Debug Server firmware" and triggering SP boot-rom. 4591This firmware often needs to be loaded during U-Boot booting. 4592 4593- CONFIG_SYS_MC_RSV_MEM_ALIGN 4594 Define alignment of reserved memory MC requires 4595 4596Reproducible builds 4597------------------- 4598 4599In order to achieve reproducible builds, timestamps used in the U-Boot build 4600process have to be set to a fixed value. 4601 4602This is done using the SOURCE_DATE_EPOCH environment variable. 4603SOURCE_DATE_EPOCH is to be set on the build host's shell, not as a configuration 4604option for U-Boot or an environment variable in U-Boot. 4605 4606SOURCE_DATE_EPOCH should be set to a number of seconds since the epoch, in UTC. 4607 4608Building the Software: 4609====================== 4610 4611Building U-Boot has been tested in several native build environments 4612and in many different cross environments. Of course we cannot support 4613all possibly existing versions of cross development tools in all 4614(potentially obsolete) versions. In case of tool chain problems we 4615recommend to use the ELDK (see http://www.denx.de/wiki/DULG/ELDK) 4616which is extensively used to build and test U-Boot. 4617 4618If you are not using a native environment, it is assumed that you 4619have GNU cross compiling tools available in your path. In this case, 4620you must set the environment variable CROSS_COMPILE in your shell. 4621Note that no changes to the Makefile or any other source files are 4622necessary. For example using the ELDK on a 4xx CPU, please enter: 4623 4624 $ CROSS_COMPILE=ppc_4xx- 4625 $ export CROSS_COMPILE 4626 4627Note: If you wish to generate Windows versions of the utilities in 4628 the tools directory you can use the MinGW toolchain 4629 (http://www.mingw.org). Set your HOST tools to the MinGW 4630 toolchain and execute 'make tools'. For example: 4631 4632 $ make HOSTCC=i586-mingw32msvc-gcc HOSTSTRIP=i586-mingw32msvc-strip tools 4633 4634 Binaries such as tools/mkimage.exe will be created which can 4635 be executed on computers running Windows. 4636 4637U-Boot is intended to be simple to build. After installing the 4638sources you must configure U-Boot for one specific board type. This 4639is done by typing: 4640 4641 make NAME_defconfig 4642 4643where "NAME_defconfig" is the name of one of the existing configu- 4644rations; see boards.cfg for supported names. 4645 4646Note: for some board special configuration names may exist; check if 4647 additional information is available from the board vendor; for 4648 instance, the TQM823L systems are available without (standard) 4649 or with LCD support. You can select such additional "features" 4650 when choosing the configuration, i. e. 4651 4652 make TQM823L_defconfig 4653 - will configure for a plain TQM823L, i. e. no LCD support 4654 4655 make TQM823L_LCD_defconfig 4656 - will configure for a TQM823L with U-Boot console on LCD 4657 4658 etc. 4659 4660 4661Finally, type "make all", and you should get some working U-Boot 4662images ready for download to / installation on your system: 4663 4664- "u-boot.bin" is a raw binary image 4665- "u-boot" is an image in ELF binary format 4666- "u-boot.srec" is in Motorola S-Record format 4667 4668By default the build is performed locally and the objects are saved 4669in the source directory. One of the two methods can be used to change 4670this behavior and build U-Boot to some external directory: 4671 46721. Add O= to the make command line invocations: 4673 4674 make O=/tmp/build distclean 4675 make O=/tmp/build NAME_defconfig 4676 make O=/tmp/build all 4677 46782. Set environment variable KBUILD_OUTPUT to point to the desired location: 4679 4680 export KBUILD_OUTPUT=/tmp/build 4681 make distclean 4682 make NAME_defconfig 4683 make all 4684 4685Note that the command line "O=" setting overrides the KBUILD_OUTPUT environment 4686variable. 4687 4688 4689Please be aware that the Makefiles assume you are using GNU make, so 4690for instance on NetBSD you might need to use "gmake" instead of 4691native "make". 4692 4693 4694If the system board that you have is not listed, then you will need 4695to port U-Boot to your hardware platform. To do this, follow these 4696steps: 4697 46981. Create a new directory to hold your board specific code. Add any 4699 files you need. In your board directory, you will need at least 4700 the "Makefile" and a "<board>.c". 47012. Create a new configuration file "include/configs/<board>.h" for 4702 your board. 47033. If you're porting U-Boot to a new CPU, then also create a new 4704 directory to hold your CPU specific code. Add any files you need. 47054. Run "make <board>_defconfig" with your new name. 47065. Type "make", and you should get a working "u-boot.srec" file 4707 to be installed on your target system. 47086. Debug and solve any problems that might arise. 4709 [Of course, this last step is much harder than it sounds.] 4710 4711 4712Testing of U-Boot Modifications, Ports to New Hardware, etc.: 4713============================================================== 4714 4715If you have modified U-Boot sources (for instance added a new board 4716or support for new devices, a new CPU, etc.) you are expected to 4717provide feedback to the other developers. The feedback normally takes 4718the form of a "patch", i. e. a context diff against a certain (latest 4719official or latest in the git repository) version of U-Boot sources. 4720 4721But before you submit such a patch, please verify that your modifi- 4722cation did not break existing code. At least make sure that *ALL* of 4723the supported boards compile WITHOUT ANY compiler warnings. To do so, 4724just run the buildman script (tools/buildman/buildman), which will 4725configure and build U-Boot for ALL supported system. Be warned, this 4726will take a while. Please see the buildman README, or run 'buildman -H' 4727for documentation. 4728 4729 4730See also "U-Boot Porting Guide" below. 4731 4732 4733Monitor Commands - Overview: 4734============================ 4735 4736go - start application at address 'addr' 4737run - run commands in an environment variable 4738bootm - boot application image from memory 4739bootp - boot image via network using BootP/TFTP protocol 4740bootz - boot zImage from memory 4741tftpboot- boot image via network using TFTP protocol 4742 and env variables "ipaddr" and "serverip" 4743 (and eventually "gatewayip") 4744tftpput - upload a file via network using TFTP protocol 4745rarpboot- boot image via network using RARP/TFTP protocol 4746diskboot- boot from IDE devicebootd - boot default, i.e., run 'bootcmd' 4747loads - load S-Record file over serial line 4748loadb - load binary file over serial line (kermit mode) 4749md - memory display 4750mm - memory modify (auto-incrementing) 4751nm - memory modify (constant address) 4752mw - memory write (fill) 4753cp - memory copy 4754cmp - memory compare 4755crc32 - checksum calculation 4756i2c - I2C sub-system 4757sspi - SPI utility commands 4758base - print or set address offset 4759printenv- print environment variables 4760setenv - set environment variables 4761saveenv - save environment variables to persistent storage 4762protect - enable or disable FLASH write protection 4763erase - erase FLASH memory 4764flinfo - print FLASH memory information 4765nand - NAND memory operations (see doc/README.nand) 4766bdinfo - print Board Info structure 4767iminfo - print header information for application image 4768coninfo - print console devices and informations 4769ide - IDE sub-system 4770loop - infinite loop on address range 4771loopw - infinite write loop on address range 4772mtest - simple RAM test 4773icache - enable or disable instruction cache 4774dcache - enable or disable data cache 4775reset - Perform RESET of the CPU 4776echo - echo args to console 4777version - print monitor version 4778help - print online help 4779? - alias for 'help' 4780 4781 4782Monitor Commands - Detailed Description: 4783======================================== 4784 4785TODO. 4786 4787For now: just type "help <command>". 4788 4789 4790Environment Variables: 4791====================== 4792 4793U-Boot supports user configuration using Environment Variables which 4794can be made persistent by saving to Flash memory. 4795 4796Environment Variables are set using "setenv", printed using 4797"printenv", and saved to Flash using "saveenv". Using "setenv" 4798without a value can be used to delete a variable from the 4799environment. As long as you don't save the environment you are 4800working with an in-memory copy. In case the Flash area containing the 4801environment is erased by accident, a default environment is provided. 4802 4803Some configuration options can be set using Environment Variables. 4804 4805List of environment variables (most likely not complete): 4806 4807 baudrate - see CONFIG_BAUDRATE 4808 4809 bootdelay - see CONFIG_BOOTDELAY 4810 4811 bootcmd - see CONFIG_BOOTCOMMAND 4812 4813 bootargs - Boot arguments when booting an RTOS image 4814 4815 bootfile - Name of the image to load with TFTP 4816 4817 bootm_low - Memory range available for image processing in the bootm 4818 command can be restricted. This variable is given as 4819 a hexadecimal number and defines lowest address allowed 4820 for use by the bootm command. See also "bootm_size" 4821 environment variable. Address defined by "bootm_low" is 4822 also the base of the initial memory mapping for the Linux 4823 kernel -- see the description of CONFIG_SYS_BOOTMAPSZ and 4824 bootm_mapsize. 4825 4826 bootm_mapsize - Size of the initial memory mapping for the Linux kernel. 4827 This variable is given as a hexadecimal number and it 4828 defines the size of the memory region starting at base 4829 address bootm_low that is accessible by the Linux kernel 4830 during early boot. If unset, CONFIG_SYS_BOOTMAPSZ is used 4831 as the default value if it is defined, and bootm_size is 4832 used otherwise. 4833 4834 bootm_size - Memory range available for image processing in the bootm 4835 command can be restricted. This variable is given as 4836 a hexadecimal number and defines the size of the region 4837 allowed for use by the bootm command. See also "bootm_low" 4838 environment variable. 4839 4840 updatefile - Location of the software update file on a TFTP server, used 4841 by the automatic software update feature. Please refer to 4842 documentation in doc/README.update for more details. 4843 4844 autoload - if set to "no" (any string beginning with 'n'), 4845 "bootp" will just load perform a lookup of the 4846 configuration from the BOOTP server, but not try to 4847 load any image using TFTP 4848 4849 autostart - if set to "yes", an image loaded using the "bootp", 4850 "rarpboot", "tftpboot" or "diskboot" commands will 4851 be automatically started (by internally calling 4852 "bootm") 4853 4854 If set to "no", a standalone image passed to the 4855 "bootm" command will be copied to the load address 4856 (and eventually uncompressed), but NOT be started. 4857 This can be used to load and uncompress arbitrary 4858 data. 4859 4860 fdt_high - if set this restricts the maximum address that the 4861 flattened device tree will be copied into upon boot. 4862 For example, if you have a system with 1 GB memory 4863 at physical address 0x10000000, while Linux kernel 4864 only recognizes the first 704 MB as low memory, you 4865 may need to set fdt_high as 0x3C000000 to have the 4866 device tree blob be copied to the maximum address 4867 of the 704 MB low memory, so that Linux kernel can 4868 access it during the boot procedure. 4869 4870 If this is set to the special value 0xFFFFFFFF then 4871 the fdt will not be copied at all on boot. For this 4872 to work it must reside in writable memory, have 4873 sufficient padding on the end of it for u-boot to 4874 add the information it needs into it, and the memory 4875 must be accessible by the kernel. 4876 4877 fdtcontroladdr- if set this is the address of the control flattened 4878 device tree used by U-Boot when CONFIG_OF_CONTROL is 4879 defined. 4880 4881 i2cfast - (PPC405GP|PPC405EP only) 4882 if set to 'y' configures Linux I2C driver for fast 4883 mode (400kHZ). This environment variable is used in 4884 initialization code. So, for changes to be effective 4885 it must be saved and board must be reset. 4886 4887 initrd_high - restrict positioning of initrd images: 4888 If this variable is not set, initrd images will be 4889 copied to the highest possible address in RAM; this 4890 is usually what you want since it allows for 4891 maximum initrd size. If for some reason you want to 4892 make sure that the initrd image is loaded below the 4893 CONFIG_SYS_BOOTMAPSZ limit, you can set this environment 4894 variable to a value of "no" or "off" or "0". 4895 Alternatively, you can set it to a maximum upper 4896 address to use (U-Boot will still check that it 4897 does not overwrite the U-Boot stack and data). 4898 4899 For instance, when you have a system with 16 MB 4900 RAM, and want to reserve 4 MB from use by Linux, 4901 you can do this by adding "mem=12M" to the value of 4902 the "bootargs" variable. However, now you must make 4903 sure that the initrd image is placed in the first 4904 12 MB as well - this can be done with 4905 4906 setenv initrd_high 00c00000 4907 4908 If you set initrd_high to 0xFFFFFFFF, this is an 4909 indication to U-Boot that all addresses are legal 4910 for the Linux kernel, including addresses in flash 4911 memory. In this case U-Boot will NOT COPY the 4912 ramdisk at all. This may be useful to reduce the 4913 boot time on your system, but requires that this 4914 feature is supported by your Linux kernel. 4915 4916 ipaddr - IP address; needed for tftpboot command 4917 4918 loadaddr - Default load address for commands like "bootp", 4919 "rarpboot", "tftpboot", "loadb" or "diskboot" 4920 4921 loads_echo - see CONFIG_LOADS_ECHO 4922 4923 serverip - TFTP server IP address; needed for tftpboot command 4924 4925 bootretry - see CONFIG_BOOT_RETRY_TIME 4926 4927 bootdelaykey - see CONFIG_AUTOBOOT_DELAY_STR 4928 4929 bootstopkey - see CONFIG_AUTOBOOT_STOP_STR 4930 4931 ethprime - controls which interface is used first. 4932 4933 ethact - controls which interface is currently active. 4934 For example you can do the following 4935 4936 => setenv ethact FEC 4937 => ping 192.168.0.1 # traffic sent on FEC 4938 => setenv ethact SCC 4939 => ping 10.0.0.1 # traffic sent on SCC 4940 4941 ethrotate - When set to "no" U-Boot does not go through all 4942 available network interfaces. 4943 It just stays at the currently selected interface. 4944 4945 netretry - When set to "no" each network operation will 4946 either succeed or fail without retrying. 4947 When set to "once" the network operation will 4948 fail when all the available network interfaces 4949 are tried once without success. 4950 Useful on scripts which control the retry operation 4951 themselves. 4952 4953 npe_ucode - set load address for the NPE microcode 4954 4955 silent_linux - If set then Linux will be told to boot silently, by 4956 changing the console to be empty. If "yes" it will be 4957 made silent. If "no" it will not be made silent. If 4958 unset, then it will be made silent if the U-Boot console 4959 is silent. 4960 4961 tftpsrcp - If this is set, the value is used for TFTP's 4962 UDP source port. 4963 4964 tftpdstp - If this is set, the value is used for TFTP's UDP 4965 destination port instead of the Well Know Port 69. 4966 4967 tftpblocksize - Block size to use for TFTP transfers; if not set, 4968 we use the TFTP server's default block size 4969 4970 tftptimeout - Retransmission timeout for TFTP packets (in milli- 4971 seconds, minimum value is 1000 = 1 second). Defines 4972 when a packet is considered to be lost so it has to 4973 be retransmitted. The default is 5000 = 5 seconds. 4974 Lowering this value may make downloads succeed 4975 faster in networks with high packet loss rates or 4976 with unreliable TFTP servers. 4977 4978 tftptimeoutcountmax - maximum count of TFTP timeouts (no 4979 unit, minimum value = 0). Defines how many timeouts 4980 can happen during a single file transfer before that 4981 transfer is aborted. The default is 10, and 0 means 4982 'no timeouts allowed'. Increasing this value may help 4983 downloads succeed with high packet loss rates, or with 4984 unreliable TFTP servers or client hardware. 4985 4986 vlan - When set to a value < 4095 the traffic over 4987 Ethernet is encapsulated/received over 802.1q 4988 VLAN tagged frames. 4989 4990 bootpretryperiod - Period during which BOOTP/DHCP sends retries. 4991 Unsigned value, in milliseconds. If not set, the period will 4992 be either the default (28000), or a value based on 4993 CONFIG_NET_RETRY_COUNT, if defined. This value has 4994 precedence over the valu based on CONFIG_NET_RETRY_COUNT. 4995 4996The following image location variables contain the location of images 4997used in booting. The "Image" column gives the role of the image and is 4998not an environment variable name. The other columns are environment 4999variable names. "File Name" gives the name of the file on a TFTP 5000server, "RAM Address" gives the location in RAM the image will be 5001loaded to, and "Flash Location" gives the image's address in NOR 5002flash or offset in NAND flash. 5003 5004*Note* - these variables don't have to be defined for all boards, some 5005boards currently use other variables for these purposes, and some 5006boards use these variables for other purposes. 5007 5008Image File Name RAM Address Flash Location 5009----- --------- ----------- -------------- 5010u-boot u-boot u-boot_addr_r u-boot_addr 5011Linux kernel bootfile kernel_addr_r kernel_addr 5012device tree blob fdtfile fdt_addr_r fdt_addr 5013ramdisk ramdiskfile ramdisk_addr_r ramdisk_addr 5014 5015The following environment variables may be used and automatically 5016updated by the network boot commands ("bootp" and "rarpboot"), 5017depending the information provided by your boot server: 5018 5019 bootfile - see above 5020 dnsip - IP address of your Domain Name Server 5021 dnsip2 - IP address of your secondary Domain Name Server 5022 gatewayip - IP address of the Gateway (Router) to use 5023 hostname - Target hostname 5024 ipaddr - see above 5025 netmask - Subnet Mask 5026 rootpath - Pathname of the root filesystem on the NFS server 5027 serverip - see above 5028 5029 5030There are two special Environment Variables: 5031 5032 serial# - contains hardware identification information such 5033 as type string and/or serial number 5034 ethaddr - Ethernet address 5035 5036These variables can be set only once (usually during manufacturing of 5037the board). U-Boot refuses to delete or overwrite these variables 5038once they have been set once. 5039 5040 5041Further special Environment Variables: 5042 5043 ver - Contains the U-Boot version string as printed 5044 with the "version" command. This variable is 5045 readonly (see CONFIG_VERSION_VARIABLE). 5046 5047 5048Please note that changes to some configuration parameters may take 5049only effect after the next boot (yes, that's just like Windoze :-). 5050 5051 5052Callback functions for environment variables: 5053--------------------------------------------- 5054 5055For some environment variables, the behavior of u-boot needs to change 5056when their values are changed. This functionality allows functions to 5057be associated with arbitrary variables. On creation, overwrite, or 5058deletion, the callback will provide the opportunity for some side 5059effect to happen or for the change to be rejected. 5060 5061The callbacks are named and associated with a function using the 5062U_BOOT_ENV_CALLBACK macro in your board or driver code. 5063 5064These callbacks are associated with variables in one of two ways. The 5065static list can be added to by defining CONFIG_ENV_CALLBACK_LIST_STATIC 5066in the board configuration to a string that defines a list of 5067associations. The list must be in the following format: 5068 5069 entry = variable_name[:callback_name] 5070 list = entry[,list] 5071 5072If the callback name is not specified, then the callback is deleted. 5073Spaces are also allowed anywhere in the list. 5074 5075Callbacks can also be associated by defining the ".callbacks" variable 5076with the same list format above. Any association in ".callbacks" will 5077override any association in the static list. You can define 5078CONFIG_ENV_CALLBACK_LIST_DEFAULT to a list (string) to define the 5079".callbacks" environment variable in the default or embedded environment. 5080 5081If CONFIG_REGEX is defined, the variable_name above is evaluated as a 5082regular expression. This allows multiple variables to be connected to 5083the same callback without explicitly listing them all out. 5084 5085 5086Command Line Parsing: 5087===================== 5088 5089There are two different command line parsers available with U-Boot: 5090the old "simple" one, and the much more powerful "hush" shell: 5091 5092Old, simple command line parser: 5093-------------------------------- 5094 5095- supports environment variables (through setenv / saveenv commands) 5096- several commands on one line, separated by ';' 5097- variable substitution using "... ${name} ..." syntax 5098- special characters ('$', ';') can be escaped by prefixing with '\', 5099 for example: 5100 setenv bootcmd bootm \${address} 5101- You can also escape text by enclosing in single apostrophes, for example: 5102 setenv addip 'setenv bootargs $bootargs ip=$ipaddr:$serverip:$gatewayip:$netmask:$hostname::off' 5103 5104Hush shell: 5105----------- 5106 5107- similar to Bourne shell, with control structures like 5108 if...then...else...fi, for...do...done; while...do...done, 5109 until...do...done, ... 5110- supports environment ("global") variables (through setenv / saveenv 5111 commands) and local shell variables (through standard shell syntax 5112 "name=value"); only environment variables can be used with "run" 5113 command 5114 5115General rules: 5116-------------- 5117 5118(1) If a command line (or an environment variable executed by a "run" 5119 command) contains several commands separated by semicolon, and 5120 one of these commands fails, then the remaining commands will be 5121 executed anyway. 5122 5123(2) If you execute several variables with one call to run (i. e. 5124 calling run with a list of variables as arguments), any failing 5125 command will cause "run" to terminate, i. e. the remaining 5126 variables are not executed. 5127 5128Note for Redundant Ethernet Interfaces: 5129======================================= 5130 5131Some boards come with redundant Ethernet interfaces; U-Boot supports 5132such configurations and is capable of automatic selection of a 5133"working" interface when needed. MAC assignment works as follows: 5134 5135Network interfaces are numbered eth0, eth1, eth2, ... Corresponding 5136MAC addresses can be stored in the environment as "ethaddr" (=>eth0), 5137"eth1addr" (=>eth1), "eth2addr", ... 5138 5139If the network interface stores some valid MAC address (for instance 5140in SROM), this is used as default address if there is NO correspon- 5141ding setting in the environment; if the corresponding environment 5142variable is set, this overrides the settings in the card; that means: 5143 5144o If the SROM has a valid MAC address, and there is no address in the 5145 environment, the SROM's address is used. 5146 5147o If there is no valid address in the SROM, and a definition in the 5148 environment exists, then the value from the environment variable is 5149 used. 5150 5151o If both the SROM and the environment contain a MAC address, and 5152 both addresses are the same, this MAC address is used. 5153 5154o If both the SROM and the environment contain a MAC address, and the 5155 addresses differ, the value from the environment is used and a 5156 warning is printed. 5157 5158o If neither SROM nor the environment contain a MAC address, an error 5159 is raised. If CONFIG_NET_RANDOM_ETHADDR is defined, then in this case 5160 a random, locally-assigned MAC is used. 5161 5162If Ethernet drivers implement the 'write_hwaddr' function, valid MAC addresses 5163will be programmed into hardware as part of the initialization process. This 5164may be skipped by setting the appropriate 'ethmacskip' environment variable. 5165The naming convention is as follows: 5166"ethmacskip" (=>eth0), "eth1macskip" (=>eth1) etc. 5167 5168Image Formats: 5169============== 5170 5171U-Boot is capable of booting (and performing other auxiliary operations on) 5172images in two formats: 5173 5174New uImage format (FIT) 5175----------------------- 5176 5177Flexible and powerful format based on Flattened Image Tree -- FIT (similar 5178to Flattened Device Tree). It allows the use of images with multiple 5179components (several kernels, ramdisks, etc.), with contents protected by 5180SHA1, MD5 or CRC32. More details are found in the doc/uImage.FIT directory. 5181 5182 5183Old uImage format 5184----------------- 5185 5186Old image format is based on binary files which can be basically anything, 5187preceded by a special header; see the definitions in include/image.h for 5188details; basically, the header defines the following image properties: 5189 5190* Target Operating System (Provisions for OpenBSD, NetBSD, FreeBSD, 5191 4.4BSD, Linux, SVR4, Esix, Solaris, Irix, SCO, Dell, NCR, VxWorks, 5192 LynxOS, pSOS, QNX, RTEMS, INTEGRITY; 5193 Currently supported: Linux, NetBSD, VxWorks, QNX, RTEMS, LynxOS, 5194 INTEGRITY). 5195* Target CPU Architecture (Provisions for Alpha, ARM, AVR32, Intel x86, 5196 IA64, MIPS, NDS32, Nios II, PowerPC, IBM S390, SuperH, Sparc, Sparc 64 Bit; 5197 Currently supported: ARM, AVR32, Intel x86, MIPS, NDS32, Nios II, PowerPC). 5198* Compression Type (uncompressed, gzip, bzip2) 5199* Load Address 5200* Entry Point 5201* Image Name 5202* Image Timestamp 5203 5204The header is marked by a special Magic Number, and both the header 5205and the data portions of the image are secured against corruption by 5206CRC32 checksums. 5207 5208 5209Linux Support: 5210============== 5211 5212Although U-Boot should support any OS or standalone application 5213easily, the main focus has always been on Linux during the design of 5214U-Boot. 5215 5216U-Boot includes many features that so far have been part of some 5217special "boot loader" code within the Linux kernel. Also, any 5218"initrd" images to be used are no longer part of one big Linux image; 5219instead, kernel and "initrd" are separate images. This implementation 5220serves several purposes: 5221 5222- the same features can be used for other OS or standalone 5223 applications (for instance: using compressed images to reduce the 5224 Flash memory footprint) 5225 5226- it becomes much easier to port new Linux kernel versions because 5227 lots of low-level, hardware dependent stuff are done by U-Boot 5228 5229- the same Linux kernel image can now be used with different "initrd" 5230 images; of course this also means that different kernel images can 5231 be run with the same "initrd". This makes testing easier (you don't 5232 have to build a new "zImage.initrd" Linux image when you just 5233 change a file in your "initrd"). Also, a field-upgrade of the 5234 software is easier now. 5235 5236 5237Linux HOWTO: 5238============ 5239 5240Porting Linux to U-Boot based systems: 5241--------------------------------------- 5242 5243U-Boot cannot save you from doing all the necessary modifications to 5244configure the Linux device drivers for use with your target hardware 5245(no, we don't intend to provide a full virtual machine interface to 5246Linux :-). 5247 5248But now you can ignore ALL boot loader code (in arch/powerpc/mbxboot). 5249 5250Just make sure your machine specific header file (for instance 5251include/asm-ppc/tqm8xx.h) includes the same definition of the Board 5252Information structure as we define in include/asm-<arch>/u-boot.h, 5253and make sure that your definition of IMAP_ADDR uses the same value 5254as your U-Boot configuration in CONFIG_SYS_IMMR. 5255 5256Note that U-Boot now has a driver model, a unified model for drivers. 5257If you are adding a new driver, plumb it into driver model. If there 5258is no uclass available, you are encouraged to create one. See 5259doc/driver-model. 5260 5261 5262Configuring the Linux kernel: 5263----------------------------- 5264 5265No specific requirements for U-Boot. Make sure you have some root 5266device (initial ramdisk, NFS) for your target system. 5267 5268 5269Building a Linux Image: 5270----------------------- 5271 5272With U-Boot, "normal" build targets like "zImage" or "bzImage" are 5273not used. If you use recent kernel source, a new build target 5274"uImage" will exist which automatically builds an image usable by 5275U-Boot. Most older kernels also have support for a "pImage" target, 5276which was introduced for our predecessor project PPCBoot and uses a 5277100% compatible format. 5278 5279Example: 5280 5281 make TQM850L_defconfig 5282 make oldconfig 5283 make dep 5284 make uImage 5285 5286The "uImage" build target uses a special tool (in 'tools/mkimage') to 5287encapsulate a compressed Linux kernel image with header information, 5288CRC32 checksum etc. for use with U-Boot. This is what we are doing: 5289 5290* build a standard "vmlinux" kernel image (in ELF binary format): 5291 5292* convert the kernel into a raw binary image: 5293 5294 ${CROSS_COMPILE}-objcopy -O binary \ 5295 -R .note -R .comment \ 5296 -S vmlinux linux.bin 5297 5298* compress the binary image: 5299 5300 gzip -9 linux.bin 5301 5302* package compressed binary image for U-Boot: 5303 5304 mkimage -A ppc -O linux -T kernel -C gzip \ 5305 -a 0 -e 0 -n "Linux Kernel Image" \ 5306 -d linux.bin.gz uImage 5307 5308 5309The "mkimage" tool can also be used to create ramdisk images for use 5310with U-Boot, either separated from the Linux kernel image, or 5311combined into one file. "mkimage" encapsulates the images with a 64 5312byte header containing information about target architecture, 5313operating system, image type, compression method, entry points, time 5314stamp, CRC32 checksums, etc. 5315 5316"mkimage" can be called in two ways: to verify existing images and 5317print the header information, or to build new images. 5318 5319In the first form (with "-l" option) mkimage lists the information 5320contained in the header of an existing U-Boot image; this includes 5321checksum verification: 5322 5323 tools/mkimage -l image 5324 -l ==> list image header information 5325 5326The second form (with "-d" option) is used to build a U-Boot image 5327from a "data file" which is used as image payload: 5328 5329 tools/mkimage -A arch -O os -T type -C comp -a addr -e ep \ 5330 -n name -d data_file image 5331 -A ==> set architecture to 'arch' 5332 -O ==> set operating system to 'os' 5333 -T ==> set image type to 'type' 5334 -C ==> set compression type 'comp' 5335 -a ==> set load address to 'addr' (hex) 5336 -e ==> set entry point to 'ep' (hex) 5337 -n ==> set image name to 'name' 5338 -d ==> use image data from 'datafile' 5339 5340Right now, all Linux kernels for PowerPC systems use the same load 5341address (0x00000000), but the entry point address depends on the 5342kernel version: 5343 5344- 2.2.x kernels have the entry point at 0x0000000C, 5345- 2.3.x and later kernels have the entry point at 0x00000000. 5346 5347So a typical call to build a U-Boot image would read: 5348 5349 -> tools/mkimage -n '2.4.4 kernel for TQM850L' \ 5350 > -A ppc -O linux -T kernel -C gzip -a 0 -e 0 \ 5351 > -d /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/powerpc/coffboot/vmlinux.gz \ 5352 > examples/uImage.TQM850L 5353 Image Name: 2.4.4 kernel for TQM850L 5354 Created: Wed Jul 19 02:34:59 2000 5355 Image Type: PowerPC Linux Kernel Image (gzip compressed) 5356 Data Size: 335725 Bytes = 327.86 kB = 0.32 MB 5357 Load Address: 0x00000000 5358 Entry Point: 0x00000000 5359 5360To verify the contents of the image (or check for corruption): 5361 5362 -> tools/mkimage -l examples/uImage.TQM850L 5363 Image Name: 2.4.4 kernel for TQM850L 5364 Created: Wed Jul 19 02:34:59 2000 5365 Image Type: PowerPC Linux Kernel Image (gzip compressed) 5366 Data Size: 335725 Bytes = 327.86 kB = 0.32 MB 5367 Load Address: 0x00000000 5368 Entry Point: 0x00000000 5369 5370NOTE: for embedded systems where boot time is critical you can trade 5371speed for memory and install an UNCOMPRESSED image instead: this 5372needs more space in Flash, but boots much faster since it does not 5373need to be uncompressed: 5374 5375 -> gunzip /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/powerpc/coffboot/vmlinux.gz 5376 -> tools/mkimage -n '2.4.4 kernel for TQM850L' \ 5377 > -A ppc -O linux -T kernel -C none -a 0 -e 0 \ 5378 > -d /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/powerpc/coffboot/vmlinux \ 5379 > examples/uImage.TQM850L-uncompressed 5380 Image Name: 2.4.4 kernel for TQM850L 5381 Created: Wed Jul 19 02:34:59 2000 5382 Image Type: PowerPC Linux Kernel Image (uncompressed) 5383 Data Size: 792160 Bytes = 773.59 kB = 0.76 MB 5384 Load Address: 0x00000000 5385 Entry Point: 0x00000000 5386 5387 5388Similar you can build U-Boot images from a 'ramdisk.image.gz' file 5389when your kernel is intended to use an initial ramdisk: 5390 5391 -> tools/mkimage -n 'Simple Ramdisk Image' \ 5392 > -A ppc -O linux -T ramdisk -C gzip \ 5393 > -d /LinuxPPC/images/SIMPLE-ramdisk.image.gz examples/simple-initrd 5394 Image Name: Simple Ramdisk Image 5395 Created: Wed Jan 12 14:01:50 2000 5396 Image Type: PowerPC Linux RAMDisk Image (gzip compressed) 5397 Data Size: 566530 Bytes = 553.25 kB = 0.54 MB 5398 Load Address: 0x00000000 5399 Entry Point: 0x00000000 5400 5401The "dumpimage" is a tool to disassemble images built by mkimage. Its "-i" 5402option performs the converse operation of the mkimage's second form (the "-d" 5403option). Given an image built by mkimage, the dumpimage extracts a "data file" 5404from the image: 5405 5406 tools/dumpimage -i image -T type -p position data_file 5407 -i ==> extract from the 'image' a specific 'data_file' 5408 -T ==> set image type to 'type' 5409 -p ==> 'position' (starting at 0) of the 'data_file' inside the 'image' 5410 5411 5412Installing a Linux Image: 5413------------------------- 5414 5415To downloading a U-Boot image over the serial (console) interface, 5416you must convert the image to S-Record format: 5417 5418 objcopy -I binary -O srec examples/image examples/image.srec 5419 5420The 'objcopy' does not understand the information in the U-Boot 5421image header, so the resulting S-Record file will be relative to 5422address 0x00000000. To load it to a given address, you need to 5423specify the target address as 'offset' parameter with the 'loads' 5424command. 5425 5426Example: install the image to address 0x40100000 (which on the 5427TQM8xxL is in the first Flash bank): 5428 5429 => erase 40100000 401FFFFF 5430 5431 .......... done 5432 Erased 8 sectors 5433 5434 => loads 40100000 5435 ## Ready for S-Record download ... 5436 ~>examples/image.srec 5437 1 2 3 4 5 6 7 8 9 10 11 12 13 ... 5438 ... 5439 15989 15990 15991 15992 5440 [file transfer complete] 5441 [connected] 5442 ## Start Addr = 0x00000000 5443 5444 5445You can check the success of the download using the 'iminfo' command; 5446this includes a checksum verification so you can be sure no data 5447corruption happened: 5448 5449 => imi 40100000 5450 5451 ## Checking Image at 40100000 ... 5452 Image Name: 2.2.13 for initrd on TQM850L 5453 Image Type: PowerPC Linux Kernel Image (gzip compressed) 5454 Data Size: 335725 Bytes = 327 kB = 0 MB 5455 Load Address: 00000000 5456 Entry Point: 0000000c 5457 Verifying Checksum ... OK 5458 5459 5460Boot Linux: 5461----------- 5462 5463The "bootm" command is used to boot an application that is stored in 5464memory (RAM or Flash). In case of a Linux kernel image, the contents 5465of the "bootargs" environment variable is passed to the kernel as 5466parameters. You can check and modify this variable using the 5467"printenv" and "setenv" commands: 5468 5469 5470 => printenv bootargs 5471 bootargs=root=/dev/ram 5472 5473 => setenv bootargs root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2 5474 5475 => printenv bootargs 5476 bootargs=root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2 5477 5478 => bootm 40020000 5479 ## Booting Linux kernel at 40020000 ... 5480 Image Name: 2.2.13 for NFS on TQM850L 5481 Image Type: PowerPC Linux Kernel Image (gzip compressed) 5482 Data Size: 381681 Bytes = 372 kB = 0 MB 5483 Load Address: 00000000 5484 Entry Point: 0000000c 5485 Verifying Checksum ... OK 5486 Uncompressing Kernel Image ... OK 5487 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 5488 Boot arguments: root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2 5489 time_init: decrementer frequency = 187500000/60 5490 Calibrating delay loop... 49.77 BogoMIPS 5491 Memory: 15208k available (700k kernel code, 444k data, 32k init) [c0000000,c1000000] 5492 ... 5493 5494If you want to boot a Linux kernel with initial RAM disk, you pass 5495the memory addresses of both the kernel and the initrd image (PPBCOOT 5496format!) to the "bootm" command: 5497 5498 => imi 40100000 40200000 5499 5500 ## Checking Image at 40100000 ... 5501 Image Name: 2.2.13 for initrd on TQM850L 5502 Image Type: PowerPC Linux Kernel Image (gzip compressed) 5503 Data Size: 335725 Bytes = 327 kB = 0 MB 5504 Load Address: 00000000 5505 Entry Point: 0000000c 5506 Verifying Checksum ... OK 5507 5508 ## Checking Image at 40200000 ... 5509 Image Name: Simple Ramdisk Image 5510 Image Type: PowerPC Linux RAMDisk Image (gzip compressed) 5511 Data Size: 566530 Bytes = 553 kB = 0 MB 5512 Load Address: 00000000 5513 Entry Point: 00000000 5514 Verifying Checksum ... OK 5515 5516 => bootm 40100000 40200000 5517 ## Booting Linux kernel at 40100000 ... 5518 Image Name: 2.2.13 for initrd on TQM850L 5519 Image Type: PowerPC Linux Kernel Image (gzip compressed) 5520 Data Size: 335725 Bytes = 327 kB = 0 MB 5521 Load Address: 00000000 5522 Entry Point: 0000000c 5523 Verifying Checksum ... OK 5524 Uncompressing Kernel Image ... OK 5525 ## Loading RAMDisk Image at 40200000 ... 5526 Image Name: Simple Ramdisk Image 5527 Image Type: PowerPC Linux RAMDisk Image (gzip compressed) 5528 Data Size: 566530 Bytes = 553 kB = 0 MB 5529 Load Address: 00000000 5530 Entry Point: 00000000 5531 Verifying Checksum ... OK 5532 Loading Ramdisk ... OK 5533 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 5534 Boot arguments: root=/dev/ram 5535 time_init: decrementer frequency = 187500000/60 5536 Calibrating delay loop... 49.77 BogoMIPS 5537 ... 5538 RAMDISK: Compressed image found at block 0 5539 VFS: Mounted root (ext2 filesystem). 5540 5541 bash# 5542 5543Boot Linux and pass a flat device tree: 5544----------- 5545 5546First, U-Boot must be compiled with the appropriate defines. See the section 5547titled "Linux Kernel Interface" above for a more in depth explanation. The 5548following is an example of how to start a kernel and pass an updated 5549flat device tree: 5550 5551=> print oftaddr 5552oftaddr=0x300000 5553=> print oft 5554oft=oftrees/mpc8540ads.dtb 5555=> tftp $oftaddr $oft 5556Speed: 1000, full duplex 5557Using TSEC0 device 5558TFTP from server 192.168.1.1; our IP address is 192.168.1.101 5559Filename 'oftrees/mpc8540ads.dtb'. 5560Load address: 0x300000 5561Loading: # 5562done 5563Bytes transferred = 4106 (100a hex) 5564=> tftp $loadaddr $bootfile 5565Speed: 1000, full duplex 5566Using TSEC0 device 5567TFTP from server 192.168.1.1; our IP address is 192.168.1.2 5568Filename 'uImage'. 5569Load address: 0x200000 5570Loading:############ 5571done 5572Bytes transferred = 1029407 (fb51f hex) 5573=> print loadaddr 5574loadaddr=200000 5575=> print oftaddr 5576oftaddr=0x300000 5577=> bootm $loadaddr - $oftaddr 5578## Booting image at 00200000 ... 5579 Image Name: Linux-2.6.17-dirty 5580 Image Type: PowerPC Linux Kernel Image (gzip compressed) 5581 Data Size: 1029343 Bytes = 1005.2 kB 5582 Load Address: 00000000 5583 Entry Point: 00000000 5584 Verifying Checksum ... OK 5585 Uncompressing Kernel Image ... OK 5586Booting using flat device tree at 0x300000 5587Using MPC85xx ADS machine description 5588Memory CAM mapping: CAM0=256Mb, CAM1=256Mb, CAM2=0Mb residual: 0Mb 5589[snip] 5590 5591 5592More About U-Boot Image Types: 5593------------------------------ 5594 5595U-Boot supports the following image types: 5596 5597 "Standalone Programs" are directly runnable in the environment 5598 provided by U-Boot; it is expected that (if they behave 5599 well) you can continue to work in U-Boot after return from 5600 the Standalone Program. 5601 "OS Kernel Images" are usually images of some Embedded OS which 5602 will take over control completely. Usually these programs 5603 will install their own set of exception handlers, device 5604 drivers, set up the MMU, etc. - this means, that you cannot 5605 expect to re-enter U-Boot except by resetting the CPU. 5606 "RAMDisk Images" are more or less just data blocks, and their 5607 parameters (address, size) are passed to an OS kernel that is 5608 being started. 5609 "Multi-File Images" contain several images, typically an OS 5610 (Linux) kernel image and one or more data images like 5611 RAMDisks. This construct is useful for instance when you want 5612 to boot over the network using BOOTP etc., where the boot 5613 server provides just a single image file, but you want to get 5614 for instance an OS kernel and a RAMDisk image. 5615 5616 "Multi-File Images" start with a list of image sizes, each 5617 image size (in bytes) specified by an "uint32_t" in network 5618 byte order. This list is terminated by an "(uint32_t)0". 5619 Immediately after the terminating 0 follow the images, one by 5620 one, all aligned on "uint32_t" boundaries (size rounded up to 5621 a multiple of 4 bytes). 5622 5623 "Firmware Images" are binary images containing firmware (like 5624 U-Boot or FPGA images) which usually will be programmed to 5625 flash memory. 5626 5627 "Script files" are command sequences that will be executed by 5628 U-Boot's command interpreter; this feature is especially 5629 useful when you configure U-Boot to use a real shell (hush) 5630 as command interpreter. 5631 5632Booting the Linux zImage: 5633------------------------- 5634 5635On some platforms, it's possible to boot Linux zImage. This is done 5636using the "bootz" command. The syntax of "bootz" command is the same 5637as the syntax of "bootm" command. 5638 5639Note, defining the CONFIG_SUPPORT_RAW_INITRD allows user to supply 5640kernel with raw initrd images. The syntax is slightly different, the 5641address of the initrd must be augmented by it's size, in the following 5642format: "<initrd addres>:<initrd size>". 5643 5644 5645Standalone HOWTO: 5646================= 5647 5648One of the features of U-Boot is that you can dynamically load and 5649run "standalone" applications, which can use some resources of 5650U-Boot like console I/O functions or interrupt services. 5651 5652Two simple examples are included with the sources: 5653 5654"Hello World" Demo: 5655------------------- 5656 5657'examples/hello_world.c' contains a small "Hello World" Demo 5658application; it is automatically compiled when you build U-Boot. 5659It's configured to run at address 0x00040004, so you can play with it 5660like that: 5661 5662 => loads 5663 ## Ready for S-Record download ... 5664 ~>examples/hello_world.srec 5665 1 2 3 4 5 6 7 8 9 10 11 ... 5666 [file transfer complete] 5667 [connected] 5668 ## Start Addr = 0x00040004 5669 5670 => go 40004 Hello World! This is a test. 5671 ## Starting application at 0x00040004 ... 5672 Hello World 5673 argc = 7 5674 argv[0] = "40004" 5675 argv[1] = "Hello" 5676 argv[2] = "World!" 5677 argv[3] = "This" 5678 argv[4] = "is" 5679 argv[5] = "a" 5680 argv[6] = "test." 5681 argv[7] = "<NULL>" 5682 Hit any key to exit ... 5683 5684 ## Application terminated, rc = 0x0 5685 5686Another example, which demonstrates how to register a CPM interrupt 5687handler with the U-Boot code, can be found in 'examples/timer.c'. 5688Here, a CPM timer is set up to generate an interrupt every second. 5689The interrupt service routine is trivial, just printing a '.' 5690character, but this is just a demo program. The application can be 5691controlled by the following keys: 5692 5693 ? - print current values og the CPM Timer registers 5694 b - enable interrupts and start timer 5695 e - stop timer and disable interrupts 5696 q - quit application 5697 5698 => loads 5699 ## Ready for S-Record download ... 5700 ~>examples/timer.srec 5701 1 2 3 4 5 6 7 8 9 10 11 ... 5702 [file transfer complete] 5703 [connected] 5704 ## Start Addr = 0x00040004 5705 5706 => go 40004 5707 ## Starting application at 0x00040004 ... 5708 TIMERS=0xfff00980 5709 Using timer 1 5710 tgcr @ 0xfff00980, tmr @ 0xfff00990, trr @ 0xfff00994, tcr @ 0xfff00998, tcn @ 0xfff0099c, ter @ 0xfff009b0 5711 5712Hit 'b': 5713 [q, b, e, ?] Set interval 1000000 us 5714 Enabling timer 5715Hit '?': 5716 [q, b, e, ?] ........ 5717 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0xef6, ter=0x0 5718Hit '?': 5719 [q, b, e, ?] . 5720 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x2ad4, ter=0x0 5721Hit '?': 5722 [q, b, e, ?] . 5723 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x1efc, ter=0x0 5724Hit '?': 5725 [q, b, e, ?] . 5726 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x169d, ter=0x0 5727Hit 'e': 5728 [q, b, e, ?] ...Stopping timer 5729Hit 'q': 5730 [q, b, e, ?] ## Application terminated, rc = 0x0 5731 5732 5733Minicom warning: 5734================ 5735 5736Over time, many people have reported problems when trying to use the 5737"minicom" terminal emulation program for serial download. I (wd) 5738consider minicom to be broken, and recommend not to use it. Under 5739Unix, I recommend to use C-Kermit for general purpose use (and 5740especially for kermit binary protocol download ("loadb" command), and 5741use "cu" for S-Record download ("loads" command). See 5742http://www.denx.de/wiki/view/DULG/SystemSetup#Section_4.3. 5743for help with kermit. 5744 5745 5746Nevertheless, if you absolutely want to use it try adding this 5747configuration to your "File transfer protocols" section: 5748 5749 Name Program Name U/D FullScr IO-Red. Multi 5750 X kermit /usr/bin/kermit -i -l %l -s Y U Y N N 5751 Y kermit /usr/bin/kermit -i -l %l -r N D Y N N 5752 5753 5754NetBSD Notes: 5755============= 5756 5757Starting at version 0.9.2, U-Boot supports NetBSD both as host 5758(build U-Boot) and target system (boots NetBSD/mpc8xx). 5759 5760Building requires a cross environment; it is known to work on 5761NetBSD/i386 with the cross-powerpc-netbsd-1.3 package (you will also 5762need gmake since the Makefiles are not compatible with BSD make). 5763Note that the cross-powerpc package does not install include files; 5764attempting to build U-Boot will fail because <machine/ansi.h> is 5765missing. This file has to be installed and patched manually: 5766 5767 # cd /usr/pkg/cross/powerpc-netbsd/include 5768 # mkdir powerpc 5769 # ln -s powerpc machine 5770 # cp /usr/src/sys/arch/powerpc/include/ansi.h powerpc/ansi.h 5771 # ${EDIT} powerpc/ansi.h ## must remove __va_list, _BSD_VA_LIST 5772 5773Native builds *don't* work due to incompatibilities between native 5774and U-Boot include files. 5775 5776Booting assumes that (the first part of) the image booted is a 5777stage-2 loader which in turn loads and then invokes the kernel 5778proper. Loader sources will eventually appear in the NetBSD source 5779tree (probably in sys/arc/mpc8xx/stand/u-boot_stage2/); in the 5780meantime, see ftp://ftp.denx.de/pub/u-boot/ppcboot_stage2.tar.gz 5781 5782 5783Implementation Internals: 5784========================= 5785 5786The following is not intended to be a complete description of every 5787implementation detail. However, it should help to understand the 5788inner workings of U-Boot and make it easier to port it to custom 5789hardware. 5790 5791 5792Initial Stack, Global Data: 5793--------------------------- 5794 5795The implementation of U-Boot is complicated by the fact that U-Boot 5796starts running out of ROM (flash memory), usually without access to 5797system RAM (because the memory controller is not initialized yet). 5798This means that we don't have writable Data or BSS segments, and BSS 5799is not initialized as zero. To be able to get a C environment working 5800at all, we have to allocate at least a minimal stack. Implementation 5801options for this are defined and restricted by the CPU used: Some CPU 5802models provide on-chip memory (like the IMMR area on MPC8xx and 5803MPC826x processors), on others (parts of) the data cache can be 5804locked as (mis-) used as memory, etc. 5805 5806 Chris Hallinan posted a good summary of these issues to the 5807 U-Boot mailing list: 5808 5809 Subject: RE: [U-Boot-Users] RE: More On Memory Bank x (nothingness)? 5810 From: "Chris Hallinan" <clh@net1plus.com> 5811 Date: Mon, 10 Feb 2003 16:43:46 -0500 (22:43 MET) 5812 ... 5813 5814 Correct me if I'm wrong, folks, but the way I understand it 5815 is this: Using DCACHE as initial RAM for Stack, etc, does not 5816 require any physical RAM backing up the cache. The cleverness 5817 is that the cache is being used as a temporary supply of 5818 necessary storage before the SDRAM controller is setup. It's 5819 beyond the scope of this list to explain the details, but you 5820 can see how this works by studying the cache architecture and 5821 operation in the architecture and processor-specific manuals. 5822 5823 OCM is On Chip Memory, which I believe the 405GP has 4K. It 5824 is another option for the system designer to use as an 5825 initial stack/RAM area prior to SDRAM being available. Either 5826 option should work for you. Using CS 4 should be fine if your 5827 board designers haven't used it for something that would 5828 cause you grief during the initial boot! It is frequently not 5829 used. 5830 5831 CONFIG_SYS_INIT_RAM_ADDR should be somewhere that won't interfere 5832 with your processor/board/system design. The default value 5833 you will find in any recent u-boot distribution in 5834 walnut.h should work for you. I'd set it to a value larger 5835 than your SDRAM module. If you have a 64MB SDRAM module, set 5836 it above 400_0000. Just make sure your board has no resources 5837 that are supposed to respond to that address! That code in 5838 start.S has been around a while and should work as is when 5839 you get the config right. 5840 5841 -Chris Hallinan 5842 DS4.COM, Inc. 5843 5844It is essential to remember this, since it has some impact on the C 5845code for the initialization procedures: 5846 5847* Initialized global data (data segment) is read-only. Do not attempt 5848 to write it. 5849 5850* Do not use any uninitialized global data (or implicitly initialized 5851 as zero data - BSS segment) at all - this is undefined, initiali- 5852 zation is performed later (when relocating to RAM). 5853 5854* Stack space is very limited. Avoid big data buffers or things like 5855 that. 5856 5857Having only the stack as writable memory limits means we cannot use 5858normal global data to share information between the code. But it 5859turned out that the implementation of U-Boot can be greatly 5860simplified by making a global data structure (gd_t) available to all 5861functions. We could pass a pointer to this data as argument to _all_ 5862functions, but this would bloat the code. Instead we use a feature of 5863the GCC compiler (Global Register Variables) to share the data: we 5864place a pointer (gd) to the global data into a register which we 5865reserve for this purpose. 5866 5867When choosing a register for such a purpose we are restricted by the 5868relevant (E)ABI specifications for the current architecture, and by 5869GCC's implementation. 5870 5871For PowerPC, the following registers have specific use: 5872 R1: stack pointer 5873 R2: reserved for system use 5874 R3-R4: parameter passing and return values 5875 R5-R10: parameter passing 5876 R13: small data area pointer 5877 R30: GOT pointer 5878 R31: frame pointer 5879 5880 (U-Boot also uses R12 as internal GOT pointer. r12 5881 is a volatile register so r12 needs to be reset when 5882 going back and forth between asm and C) 5883 5884 ==> U-Boot will use R2 to hold a pointer to the global data 5885 5886 Note: on PPC, we could use a static initializer (since the 5887 address of the global data structure is known at compile time), 5888 but it turned out that reserving a register results in somewhat 5889 smaller code - although the code savings are not that big (on 5890 average for all boards 752 bytes for the whole U-Boot image, 5891 624 text + 127 data). 5892 5893On ARM, the following registers are used: 5894 5895 R0: function argument word/integer result 5896 R1-R3: function argument word 5897 R9: platform specific 5898 R10: stack limit (used only if stack checking is enabled) 5899 R11: argument (frame) pointer 5900 R12: temporary workspace 5901 R13: stack pointer 5902 R14: link register 5903 R15: program counter 5904 5905 ==> U-Boot will use R9 to hold a pointer to the global data 5906 5907 Note: on ARM, only R_ARM_RELATIVE relocations are supported. 5908 5909On Nios II, the ABI is documented here: 5910 http://www.altera.com/literature/hb/nios2/n2cpu_nii51016.pdf 5911 5912 ==> U-Boot will use gp to hold a pointer to the global data 5913 5914 Note: on Nios II, we give "-G0" option to gcc and don't use gp 5915 to access small data sections, so gp is free. 5916 5917On NDS32, the following registers are used: 5918 5919 R0-R1: argument/return 5920 R2-R5: argument 5921 R15: temporary register for assembler 5922 R16: trampoline register 5923 R28: frame pointer (FP) 5924 R29: global pointer (GP) 5925 R30: link register (LP) 5926 R31: stack pointer (SP) 5927 PC: program counter (PC) 5928 5929 ==> U-Boot will use R10 to hold a pointer to the global data 5930 5931NOTE: DECLARE_GLOBAL_DATA_PTR must be used with file-global scope, 5932or current versions of GCC may "optimize" the code too much. 5933 5934Memory Management: 5935------------------ 5936 5937U-Boot runs in system state and uses physical addresses, i.e. the 5938MMU is not used either for address mapping nor for memory protection. 5939 5940The available memory is mapped to fixed addresses using the memory 5941controller. In this process, a contiguous block is formed for each 5942memory type (Flash, SDRAM, SRAM), even when it consists of several 5943physical memory banks. 5944 5945U-Boot is installed in the first 128 kB of the first Flash bank (on 5946TQM8xxL modules this is the range 0x40000000 ... 0x4001FFFF). After 5947booting and sizing and initializing DRAM, the code relocates itself 5948to the upper end of DRAM. Immediately below the U-Boot code some 5949memory is reserved for use by malloc() [see CONFIG_SYS_MALLOC_LEN 5950configuration setting]. Below that, a structure with global Board 5951Info data is placed, followed by the stack (growing downward). 5952 5953Additionally, some exception handler code is copied to the low 8 kB 5954of DRAM (0x00000000 ... 0x00001FFF). 5955 5956So a typical memory configuration with 16 MB of DRAM could look like 5957this: 5958 5959 0x0000 0000 Exception Vector code 5960 : 5961 0x0000 1FFF 5962 0x0000 2000 Free for Application Use 5963 : 5964 : 5965 5966 : 5967 : 5968 0x00FB FF20 Monitor Stack (Growing downward) 5969 0x00FB FFAC Board Info Data and permanent copy of global data 5970 0x00FC 0000 Malloc Arena 5971 : 5972 0x00FD FFFF 5973 0x00FE 0000 RAM Copy of Monitor Code 5974 ... eventually: LCD or video framebuffer 5975 ... eventually: pRAM (Protected RAM - unchanged by reset) 5976 0x00FF FFFF [End of RAM] 5977 5978 5979System Initialization: 5980---------------------- 5981 5982In the reset configuration, U-Boot starts at the reset entry point 5983(on most PowerPC systems at address 0x00000100). Because of the reset 5984configuration for CS0# this is a mirror of the on board Flash memory. 5985To be able to re-map memory U-Boot then jumps to its link address. 5986To be able to implement the initialization code in C, a (small!) 5987initial stack is set up in the internal Dual Ported RAM (in case CPUs 5988which provide such a feature like MPC8xx or MPC8260), or in a locked 5989part of the data cache. After that, U-Boot initializes the CPU core, 5990the caches and the SIU. 5991 5992Next, all (potentially) available memory banks are mapped using a 5993preliminary mapping. For example, we put them on 512 MB boundaries 5994(multiples of 0x20000000: SDRAM on 0x00000000 and 0x20000000, Flash 5995on 0x40000000 and 0x60000000, SRAM on 0x80000000). Then UPM A is 5996programmed for SDRAM access. Using the temporary configuration, a 5997simple memory test is run that determines the size of the SDRAM 5998banks. 5999 6000When there is more than one SDRAM bank, and the banks are of 6001different size, the largest is mapped first. For equal size, the first 6002bank (CS2#) is mapped first. The first mapping is always for address 60030x00000000, with any additional banks following immediately to create 6004contiguous memory starting from 0. 6005 6006Then, the monitor installs itself at the upper end of the SDRAM area 6007and allocates memory for use by malloc() and for the global Board 6008Info data; also, the exception vector code is copied to the low RAM 6009pages, and the final stack is set up. 6010 6011Only after this relocation will you have a "normal" C environment; 6012until that you are restricted in several ways, mostly because you are 6013running from ROM, and because the code will have to be relocated to a 6014new address in RAM. 6015 6016 6017U-Boot Porting Guide: 6018---------------------- 6019 6020[Based on messages by Jerry Van Baren in the U-Boot-Users mailing 6021list, October 2002] 6022 6023 6024int main(int argc, char *argv[]) 6025{ 6026 sighandler_t no_more_time; 6027 6028 signal(SIGALRM, no_more_time); 6029 alarm(PROJECT_DEADLINE - toSec (3 * WEEK)); 6030 6031 if (available_money > available_manpower) { 6032 Pay consultant to port U-Boot; 6033 return 0; 6034 } 6035 6036 Download latest U-Boot source; 6037 6038 Subscribe to u-boot mailing list; 6039 6040 if (clueless) 6041 email("Hi, I am new to U-Boot, how do I get started?"); 6042 6043 while (learning) { 6044 Read the README file in the top level directory; 6045 Read http://www.denx.de/twiki/bin/view/DULG/Manual; 6046 Read applicable doc/*.README; 6047 Read the source, Luke; 6048 /* find . -name "*.[chS]" | xargs grep -i <keyword> */ 6049 } 6050 6051 if (available_money > toLocalCurrency ($2500)) 6052 Buy a BDI3000; 6053 else 6054 Add a lot of aggravation and time; 6055 6056 if (a similar board exists) { /* hopefully... */ 6057 cp -a board/<similar> board/<myboard> 6058 cp include/configs/<similar>.h include/configs/<myboard>.h 6059 } else { 6060 Create your own board support subdirectory; 6061 Create your own board include/configs/<myboard>.h file; 6062 } 6063 Edit new board/<myboard> files 6064 Edit new include/configs/<myboard>.h 6065 6066 while (!accepted) { 6067 while (!running) { 6068 do { 6069 Add / modify source code; 6070 } until (compiles); 6071 Debug; 6072 if (clueless) 6073 email("Hi, I am having problems..."); 6074 } 6075 Send patch file to the U-Boot email list; 6076 if (reasonable critiques) 6077 Incorporate improvements from email list code review; 6078 else 6079 Defend code as written; 6080 } 6081 6082 return 0; 6083} 6084 6085void no_more_time (int sig) 6086{ 6087 hire_a_guru(); 6088} 6089 6090 6091Coding Standards: 6092----------------- 6093 6094All contributions to U-Boot should conform to the Linux kernel 6095coding style; see the file "Documentation/CodingStyle" and the script 6096"scripts/Lindent" in your Linux kernel source directory. 6097 6098Source files originating from a different project (for example the 6099MTD subsystem) are generally exempt from these guidelines and are not 6100reformatted to ease subsequent migration to newer versions of those 6101sources. 6102 6103Please note that U-Boot is implemented in C (and to some small parts in 6104Assembler); no C++ is used, so please do not use C++ style comments (//) 6105in your code. 6106 6107Please also stick to the following formatting rules: 6108- remove any trailing white space 6109- use TAB characters for indentation and vertical alignment, not spaces 6110- make sure NOT to use DOS '\r\n' line feeds 6111- do not add more than 2 consecutive empty lines to source files 6112- do not add trailing empty lines to source files 6113 6114Submissions which do not conform to the standards may be returned 6115with a request to reformat the changes. 6116 6117 6118Submitting Patches: 6119------------------- 6120 6121Since the number of patches for U-Boot is growing, we need to 6122establish some rules. Submissions which do not conform to these rules 6123may be rejected, even when they contain important and valuable stuff. 6124 6125Please see http://www.denx.de/wiki/U-Boot/Patches for details. 6126 6127Patches shall be sent to the u-boot mailing list <u-boot@lists.denx.de>; 6128see http://lists.denx.de/mailman/listinfo/u-boot 6129 6130When you send a patch, please include the following information with 6131it: 6132 6133* For bug fixes: a description of the bug and how your patch fixes 6134 this bug. Please try to include a way of demonstrating that the 6135 patch actually fixes something. 6136 6137* For new features: a description of the feature and your 6138 implementation. 6139 6140* A CHANGELOG entry as plaintext (separate from the patch) 6141 6142* For major contributions, add a MAINTAINERS file with your 6143 information and associated file and directory references. 6144 6145* When you add support for a new board, don't forget to add a 6146 maintainer e-mail address to the boards.cfg file, too. 6147 6148* If your patch adds new configuration options, don't forget to 6149 document these in the README file. 6150 6151* The patch itself. If you are using git (which is *strongly* 6152 recommended) you can easily generate the patch using the 6153 "git format-patch". If you then use "git send-email" to send it to 6154 the U-Boot mailing list, you will avoid most of the common problems 6155 with some other mail clients. 6156 6157 If you cannot use git, use "diff -purN OLD NEW". If your version of 6158 diff does not support these options, then get the latest version of 6159 GNU diff. 6160 6161 The current directory when running this command shall be the parent 6162 directory of the U-Boot source tree (i. e. please make sure that 6163 your patch includes sufficient directory information for the 6164 affected files). 6165 6166 We prefer patches as plain text. MIME attachments are discouraged, 6167 and compressed attachments must not be used. 6168 6169* If one logical set of modifications affects or creates several 6170 files, all these changes shall be submitted in a SINGLE patch file. 6171 6172* Changesets that contain different, unrelated modifications shall be 6173 submitted as SEPARATE patches, one patch per changeset. 6174 6175 6176Notes: 6177 6178* Before sending the patch, run the buildman script on your patched 6179 source tree and make sure that no errors or warnings are reported 6180 for any of the boards. 6181 6182* Keep your modifications to the necessary minimum: A patch 6183 containing several unrelated changes or arbitrary reformats will be 6184 returned with a request to re-formatting / split it. 6185 6186* If you modify existing code, make sure that your new code does not 6187 add to the memory footprint of the code ;-) Small is beautiful! 6188 When adding new features, these should compile conditionally only 6189 (using #ifdef), and the resulting code with the new feature 6190 disabled must not need more memory than the old code without your 6191 modification. 6192 6193* Remember that there is a size limit of 100 kB per message on the 6194 u-boot mailing list. Bigger patches will be moderated. If they are 6195 reasonable and not too big, they will be acknowledged. But patches 6196 bigger than the size limit should be avoided. 6197