1# 2# (C) Copyright 2000 - 2013 3# Wolfgang Denk, DENX Software Engineering, wd@denx.de. 4# 5# SPDX-License-Identifier: GPL-2.0+ 6# 7 8Summary: 9======== 10 11This directory contains the source code for U-Boot, a boot loader for 12Embedded boards based on PowerPC, ARM, MIPS and several other 13processors, which can be installed in a boot ROM and used to 14initialize and test the hardware or to download and run application 15code. 16 17The development of U-Boot is closely related to Linux: some parts of 18the source code originate in the Linux source tree, we have some 19header files in common, and special provision has been made to 20support booting of Linux images. 21 22Some attention has been paid to make this software easily 23configurable and extendable. For instance, all monitor commands are 24implemented with the same call interface, so that it's very easy to 25add new commands. Also, instead of permanently adding rarely used 26code (for instance hardware test utilities) to the monitor, you can 27load and run it dynamically. 28 29 30Status: 31======= 32 33In general, all boards for which a configuration option exists in the 34Makefile have been tested to some extent and can be considered 35"working". In fact, many of them are used in production systems. 36 37In case of problems see the CHANGELOG file to find out who contributed 38the specific port. In addition, there are various MAINTAINERS files 39scattered throughout the U-Boot source identifying the people or 40companies responsible for various boards and subsystems. 41 42Note: As of August, 2010, there is no longer a CHANGELOG file in the 43actual U-Boot source tree; however, it can be created dynamically 44from the Git log using: 45 46 make CHANGELOG 47 48 49Where to get help: 50================== 51 52In case you have questions about, problems with or contributions for 53U-Boot, you should send a message to the U-Boot mailing list at 54<u-boot@lists.denx.de>. There is also an archive of previous traffic 55on the mailing list - please search the archive before asking FAQ's. 56Please see http://lists.denx.de/pipermail/u-boot and 57http://dir.gmane.org/gmane.comp.boot-loaders.u-boot 58 59 60Where to get source code: 61========================= 62 63The U-Boot source code is maintained in the Git repository at 64git://www.denx.de/git/u-boot.git ; you can browse it online at 65http://www.denx.de/cgi-bin/gitweb.cgi?p=u-boot.git;a=summary 66 67The "snapshot" links on this page allow you to download tarballs of 68any version you might be interested in. Official releases are also 69available for FTP download from the ftp://ftp.denx.de/pub/u-boot/ 70directory. 71 72Pre-built (and tested) images are available from 73ftp://ftp.denx.de/pub/u-boot/images/ 74 75 76Where we come from: 77=================== 78 79- start from 8xxrom sources 80- create PPCBoot project (http://sourceforge.net/projects/ppcboot) 81- clean up code 82- make it easier to add custom boards 83- make it possible to add other [PowerPC] CPUs 84- extend functions, especially: 85 * Provide extended interface to Linux boot loader 86 * S-Record download 87 * network boot 88 * PCMCIA / CompactFlash / ATA disk / SCSI ... boot 89- create ARMBoot project (http://sourceforge.net/projects/armboot) 90- add other CPU families (starting with ARM) 91- create U-Boot project (http://sourceforge.net/projects/u-boot) 92- current project page: see http://www.denx.de/wiki/U-Boot 93 94 95Names and Spelling: 96=================== 97 98The "official" name of this project is "Das U-Boot". The spelling 99"U-Boot" shall be used in all written text (documentation, comments 100in source files etc.). Example: 101 102 This is the README file for the U-Boot project. 103 104File names etc. shall be based on the string "u-boot". Examples: 105 106 include/asm-ppc/u-boot.h 107 108 #include <asm/u-boot.h> 109 110Variable names, preprocessor constants etc. shall be either based on 111the string "u_boot" or on "U_BOOT". Example: 112 113 U_BOOT_VERSION u_boot_logo 114 IH_OS_U_BOOT u_boot_hush_start 115 116 117Versioning: 118=========== 119 120Starting with the release in October 2008, the names of the releases 121were changed from numerical release numbers without deeper meaning 122into a time stamp based numbering. Regular releases are identified by 123names consisting of the calendar year and month of the release date. 124Additional fields (if present) indicate release candidates or bug fix 125releases in "stable" maintenance trees. 126 127Examples: 128 U-Boot v2009.11 - Release November 2009 129 U-Boot v2009.11.1 - Release 1 in version November 2009 stable tree 130 U-Boot v2010.09-rc1 - Release candidate 1 for September 2010 release 131 132 133Directory Hierarchy: 134==================== 135 136/arch Architecture specific files 137 /arc Files generic to ARC architecture 138 /arm Files generic to ARM architecture 139 /avr32 Files generic to AVR32 architecture 140 /m68k Files generic to m68k architecture 141 /microblaze Files generic to microblaze architecture 142 /mips Files generic to MIPS architecture 143 /nds32 Files generic to NDS32 architecture 144 /nios2 Files generic to Altera NIOS2 architecture 145 /openrisc Files generic to OpenRISC architecture 146 /powerpc Files generic to PowerPC architecture 147 /sandbox Files generic to HW-independent "sandbox" 148 /sh Files generic to SH architecture 149 /x86 Files generic to x86 architecture 150/api Machine/arch independent API for external apps 151/board Board dependent files 152/cmd U-Boot commands functions 153/common Misc architecture independent functions 154/configs Board default configuration files 155/disk Code for disk drive partition handling 156/doc Documentation (don't expect too much) 157/drivers Commonly used device drivers 158/dts Contains Makefile for building internal U-Boot fdt. 159/examples Example code for standalone applications, etc. 160/fs Filesystem code (cramfs, ext2, jffs2, etc.) 161/include Header Files 162/lib Library routines generic to all architectures 163/Licenses Various license files 164/net Networking code 165/post Power On Self Test 166/scripts Various build scripts and Makefiles 167/test Various unit test files 168/tools Tools to build S-Record or U-Boot images, etc. 169 170Software Configuration: 171======================= 172 173Configuration is usually done using C preprocessor defines; the 174rationale behind that is to avoid dead code whenever possible. 175 176There are two classes of configuration variables: 177 178* Configuration _OPTIONS_: 179 These are selectable by the user and have names beginning with 180 "CONFIG_". 181 182* Configuration _SETTINGS_: 183 These depend on the hardware etc. and should not be meddled with if 184 you don't know what you're doing; they have names beginning with 185 "CONFIG_SYS_". 186 187Previously, all configuration was done by hand, which involved creating 188symbolic links and editing configuration files manually. More recently, 189U-Boot has added the Kbuild infrastructure used by the Linux kernel, 190allowing you to use the "make menuconfig" command to configure your 191build. 192 193 194Selection of Processor Architecture and Board Type: 195--------------------------------------------------- 196 197For all supported boards there are ready-to-use default 198configurations available; just type "make <board_name>_defconfig". 199 200Example: For a TQM823L module type: 201 202 cd u-boot 203 make TQM823L_defconfig 204 205Note: If you're looking for the default configuration file for a board 206you're sure used to be there but is now missing, check the file 207doc/README.scrapyard for a list of no longer supported boards. 208 209Sandbox Environment: 210-------------------- 211 212U-Boot can be built natively to run on a Linux host using the 'sandbox' 213board. This allows feature development which is not board- or architecture- 214specific to be undertaken on a native platform. The sandbox is also used to 215run some of U-Boot's tests. 216 217See board/sandbox/README.sandbox for more details. 218 219 220Board Initialisation Flow: 221-------------------------- 222 223This is the intended start-up flow for boards. This should apply for both 224SPL and U-Boot proper (i.e. they both follow the same rules). 225 226Note: "SPL" stands for "Secondary Program Loader," which is explained in 227more detail later in this file. 228 229At present, SPL mostly uses a separate code path, but the function names 230and roles of each function are the same. Some boards or architectures 231may not conform to this. At least most ARM boards which use 232CONFIG_SPL_FRAMEWORK conform to this. 233 234Execution typically starts with an architecture-specific (and possibly 235CPU-specific) start.S file, such as: 236 237 - arch/arm/cpu/armv7/start.S 238 - arch/powerpc/cpu/mpc83xx/start.S 239 - arch/mips/cpu/start.S 240 241and so on. From there, three functions are called; the purpose and 242limitations of each of these functions are described below. 243 244lowlevel_init(): 245 - purpose: essential init to permit execution to reach board_init_f() 246 - no global_data or BSS 247 - there is no stack (ARMv7 may have one but it will soon be removed) 248 - must not set up SDRAM or use console 249 - must only do the bare minimum to allow execution to continue to 250 board_init_f() 251 - this is almost never needed 252 - return normally from this function 253 254board_init_f(): 255 - purpose: set up the machine ready for running board_init_r(): 256 i.e. SDRAM and serial UART 257 - global_data is available 258 - stack is in SRAM 259 - BSS is not available, so you cannot use global/static variables, 260 only stack variables and global_data 261 262 Non-SPL-specific notes: 263 - dram_init() is called to set up DRAM. If already done in SPL this 264 can do nothing 265 266 SPL-specific notes: 267 - you can override the entire board_init_f() function with your own 268 version as needed. 269 - preloader_console_init() can be called here in extremis 270 - should set up SDRAM, and anything needed to make the UART work 271 - these is no need to clear BSS, it will be done by crt0.S 272 - must return normally from this function (don't call board_init_r() 273 directly) 274 275Here the BSS is cleared. For SPL, if CONFIG_SPL_STACK_R is defined, then at 276this point the stack and global_data are relocated to below 277CONFIG_SPL_STACK_R_ADDR. For non-SPL, U-Boot is relocated to run at the top of 278memory. 279 280board_init_r(): 281 - purpose: main execution, common code 282 - global_data is available 283 - SDRAM is available 284 - BSS is available, all static/global variables can be used 285 - execution eventually continues to main_loop() 286 287 Non-SPL-specific notes: 288 - U-Boot is relocated to the top of memory and is now running from 289 there. 290 291 SPL-specific notes: 292 - stack is optionally in SDRAM, if CONFIG_SPL_STACK_R is defined and 293 CONFIG_SPL_STACK_R_ADDR points into SDRAM 294 - preloader_console_init() can be called here - typically this is 295 done by defining CONFIG_SPL_BOARD_INIT and then supplying a 296 spl_board_init() function containing this call 297 - loads U-Boot or (in falcon mode) Linux 298 299 300 301Configuration Options: 302---------------------- 303 304Configuration depends on the combination of board and CPU type; all 305such information is kept in a configuration file 306"include/configs/<board_name>.h". 307 308Example: For a TQM823L module, all configuration settings are in 309"include/configs/TQM823L.h". 310 311 312Many of the options are named exactly as the corresponding Linux 313kernel configuration options. The intention is to make it easier to 314build a config tool - later. 315 316 317The following options need to be configured: 318 319- CPU Type: Define exactly one, e.g. CONFIG_MPC85XX. 320 321- Board Type: Define exactly one, e.g. CONFIG_MPC8540ADS. 322 323- CPU Daughterboard Type: (if CONFIG_ATSTK1000 is defined) 324 Define exactly one, e.g. CONFIG_ATSTK1002 325 326- Marvell Family Member 327 CONFIG_SYS_MVFS - define it if you want to enable 328 multiple fs option at one time 329 for marvell soc family 330 331- 8xx CPU Options: (if using an MPC8xx CPU) 332 CONFIG_8xx_GCLK_FREQ - deprecated: CPU clock if 333 get_gclk_freq() cannot work 334 e.g. if there is no 32KHz 335 reference PIT/RTC clock 336 CONFIG_8xx_OSCLK - PLL input clock (either EXTCLK 337 or XTAL/EXTAL) 338 339- 859/866/885 CPU options: (if using a MPC859 or MPC866 or MPC885 CPU): 340 CONFIG_SYS_8xx_CPUCLK_MIN 341 CONFIG_SYS_8xx_CPUCLK_MAX 342 CONFIG_8xx_CPUCLK_DEFAULT 343 See doc/README.MPC866 344 345 CONFIG_SYS_MEASURE_CPUCLK 346 347 Define this to measure the actual CPU clock instead 348 of relying on the correctness of the configured 349 values. Mostly useful for board bringup to make sure 350 the PLL is locked at the intended frequency. Note 351 that this requires a (stable) reference clock (32 kHz 352 RTC clock or CONFIG_SYS_8XX_XIN) 353 354 CONFIG_SYS_DELAYED_ICACHE 355 356 Define this option if you want to enable the 357 ICache only when Code runs from RAM. 358 359- 85xx CPU Options: 360 CONFIG_SYS_PPC64 361 362 Specifies that the core is a 64-bit PowerPC implementation (implements 363 the "64" category of the Power ISA). This is necessary for ePAPR 364 compliance, among other possible reasons. 365 366 CONFIG_SYS_FSL_TBCLK_DIV 367 368 Defines the core time base clock divider ratio compared to the 369 system clock. On most PQ3 devices this is 8, on newer QorIQ 370 devices it can be 16 or 32. The ratio varies from SoC to Soc. 371 372 CONFIG_SYS_FSL_PCIE_COMPAT 373 374 Defines the string to utilize when trying to match PCIe device 375 tree nodes for the given platform. 376 377 CONFIG_SYS_FSL_ERRATUM_A004510 378 379 Enables a workaround for erratum A004510. If set, 380 then CONFIG_SYS_FSL_ERRATUM_A004510_SVR_REV and 381 CONFIG_SYS_FSL_CORENET_SNOOPVEC_COREONLY must be set. 382 383 CONFIG_SYS_FSL_ERRATUM_A004510_SVR_REV 384 CONFIG_SYS_FSL_ERRATUM_A004510_SVR_REV2 (optional) 385 386 Defines one or two SoC revisions (low 8 bits of SVR) 387 for which the A004510 workaround should be applied. 388 389 The rest of SVR is either not relevant to the decision 390 of whether the erratum is present (e.g. p2040 versus 391 p2041) or is implied by the build target, which controls 392 whether CONFIG_SYS_FSL_ERRATUM_A004510 is set. 393 394 See Freescale App Note 4493 for more information about 395 this erratum. 396 397 CONFIG_A003399_NOR_WORKAROUND 398 Enables a workaround for IFC erratum A003399. It is only 399 required during NOR boot. 400 401 CONFIG_A008044_WORKAROUND 402 Enables a workaround for T1040/T1042 erratum A008044. It is only 403 required during NAND boot and valid for Rev 1.0 SoC revision 404 405 CONFIG_SYS_FSL_CORENET_SNOOPVEC_COREONLY 406 407 This is the value to write into CCSR offset 0x18600 408 according to the A004510 workaround. 409 410 CONFIG_SYS_FSL_DSP_DDR_ADDR 411 This value denotes start offset of DDR memory which is 412 connected exclusively to the DSP cores. 413 414 CONFIG_SYS_FSL_DSP_M2_RAM_ADDR 415 This value denotes start offset of M2 memory 416 which is directly connected to the DSP core. 417 418 CONFIG_SYS_FSL_DSP_M3_RAM_ADDR 419 This value denotes start offset of M3 memory which is directly 420 connected to the DSP core. 421 422 CONFIG_SYS_FSL_DSP_CCSRBAR_DEFAULT 423 This value denotes start offset of DSP CCSR space. 424 425 CONFIG_SYS_FSL_SINGLE_SOURCE_CLK 426 Single Source Clock is clocking mode present in some of FSL SoC's. 427 In this mode, a single differential clock is used to supply 428 clocks to the sysclock, ddrclock and usbclock. 429 430 CONFIG_SYS_CPC_REINIT_F 431 This CONFIG is defined when the CPC is configured as SRAM at the 432 time of U-Boot entry and is required to be re-initialized. 433 434 CONFIG_DEEP_SLEEP 435 Indicates this SoC supports deep sleep feature. If deep sleep is 436 supported, core will start to execute uboot when wakes up. 437 438- Generic CPU options: 439 CONFIG_SYS_GENERIC_GLOBAL_DATA 440 Defines global data is initialized in generic board board_init_f(). 441 If this macro is defined, global data is created and cleared in 442 generic board board_init_f(). Without this macro, architecture/board 443 should initialize global data before calling board_init_f(). 444 445 CONFIG_SYS_BIG_ENDIAN, CONFIG_SYS_LITTLE_ENDIAN 446 447 Defines the endianess of the CPU. Implementation of those 448 values is arch specific. 449 450 CONFIG_SYS_FSL_DDR 451 Freescale DDR driver in use. This type of DDR controller is 452 found in mpc83xx, mpc85xx, mpc86xx as well as some ARM core 453 SoCs. 454 455 CONFIG_SYS_FSL_DDR_ADDR 456 Freescale DDR memory-mapped register base. 457 458 CONFIG_SYS_FSL_DDR_EMU 459 Specify emulator support for DDR. Some DDR features such as 460 deskew training are not available. 461 462 CONFIG_SYS_FSL_DDRC_GEN1 463 Freescale DDR1 controller. 464 465 CONFIG_SYS_FSL_DDRC_GEN2 466 Freescale DDR2 controller. 467 468 CONFIG_SYS_FSL_DDRC_GEN3 469 Freescale DDR3 controller. 470 471 CONFIG_SYS_FSL_DDRC_GEN4 472 Freescale DDR4 controller. 473 474 CONFIG_SYS_FSL_DDRC_ARM_GEN3 475 Freescale DDR3 controller for ARM-based SoCs. 476 477 CONFIG_SYS_FSL_DDR1 478 Board config to use DDR1. It can be enabled for SoCs with 479 Freescale DDR1 or DDR2 controllers, depending on the board 480 implemetation. 481 482 CONFIG_SYS_FSL_DDR2 483 Board config to use DDR2. It can be enabled for SoCs with 484 Freescale DDR2 or DDR3 controllers, depending on the board 485 implementation. 486 487 CONFIG_SYS_FSL_DDR3 488 Board config to use DDR3. It can be enabled for SoCs with 489 Freescale DDR3 or DDR3L controllers. 490 491 CONFIG_SYS_FSL_DDR3L 492 Board config to use DDR3L. It can be enabled for SoCs with 493 DDR3L controllers. 494 495 CONFIG_SYS_FSL_DDR4 496 Board config to use DDR4. It can be enabled for SoCs with 497 DDR4 controllers. 498 499 CONFIG_SYS_FSL_IFC_BE 500 Defines the IFC controller register space as Big Endian 501 502 CONFIG_SYS_FSL_IFC_LE 503 Defines the IFC controller register space as Little Endian 504 505 CONFIG_SYS_FSL_IFC_CLK_DIV 506 Defines divider of platform clock(clock input to IFC controller). 507 508 CONFIG_SYS_FSL_LBC_CLK_DIV 509 Defines divider of platform clock(clock input to eLBC controller). 510 511 CONFIG_SYS_FSL_PBL_PBI 512 It enables addition of RCW (Power on reset configuration) in built image. 513 Please refer doc/README.pblimage for more details 514 515 CONFIG_SYS_FSL_PBL_RCW 516 It adds PBI(pre-boot instructions) commands in u-boot build image. 517 PBI commands can be used to configure SoC before it starts the execution. 518 Please refer doc/README.pblimage for more details 519 520 CONFIG_SPL_FSL_PBL 521 It adds a target to create boot binary having SPL binary in PBI format 522 concatenated with u-boot binary. 523 524 CONFIG_SYS_FSL_DDR_BE 525 Defines the DDR controller register space as Big Endian 526 527 CONFIG_SYS_FSL_DDR_LE 528 Defines the DDR controller register space as Little Endian 529 530 CONFIG_SYS_FSL_DDR_SDRAM_BASE_PHY 531 Physical address from the view of DDR controllers. It is the 532 same as CONFIG_SYS_DDR_SDRAM_BASE for all Power SoCs. But 533 it could be different for ARM SoCs. 534 535 CONFIG_SYS_FSL_DDR_INTLV_256B 536 DDR controller interleaving on 256-byte. This is a special 537 interleaving mode, handled by Dickens for Freescale layerscape 538 SoCs with ARM core. 539 540 CONFIG_SYS_FSL_DDR_MAIN_NUM_CTRLS 541 Number of controllers used as main memory. 542 543 CONFIG_SYS_FSL_OTHER_DDR_NUM_CTRLS 544 Number of controllers used for other than main memory. 545 546 CONFIG_SYS_FSL_HAS_DP_DDR 547 Defines the SoC has DP-DDR used for DPAA. 548 549 CONFIG_SYS_FSL_SEC_BE 550 Defines the SEC controller register space as Big Endian 551 552 CONFIG_SYS_FSL_SEC_LE 553 Defines the SEC controller register space as Little Endian 554 555- MIPS CPU options: 556 CONFIG_SYS_INIT_SP_OFFSET 557 558 Offset relative to CONFIG_SYS_SDRAM_BASE for initial stack 559 pointer. This is needed for the temporary stack before 560 relocation. 561 562 CONFIG_SYS_MIPS_CACHE_MODE 563 564 Cache operation mode for the MIPS CPU. 565 See also arch/mips/include/asm/mipsregs.h. 566 Possible values are: 567 CONF_CM_CACHABLE_NO_WA 568 CONF_CM_CACHABLE_WA 569 CONF_CM_UNCACHED 570 CONF_CM_CACHABLE_NONCOHERENT 571 CONF_CM_CACHABLE_CE 572 CONF_CM_CACHABLE_COW 573 CONF_CM_CACHABLE_CUW 574 CONF_CM_CACHABLE_ACCELERATED 575 576 CONFIG_SYS_XWAY_EBU_BOOTCFG 577 578 Special option for Lantiq XWAY SoCs for booting from NOR flash. 579 See also arch/mips/cpu/mips32/start.S. 580 581 CONFIG_XWAY_SWAP_BYTES 582 583 Enable compilation of tools/xway-swap-bytes needed for Lantiq 584 XWAY SoCs for booting from NOR flash. The U-Boot image needs to 585 be swapped if a flash programmer is used. 586 587- ARM options: 588 CONFIG_SYS_EXCEPTION_VECTORS_HIGH 589 590 Select high exception vectors of the ARM core, e.g., do not 591 clear the V bit of the c1 register of CP15. 592 593 COUNTER_FREQUENCY 594 Generic timer clock source frequency. 595 596 COUNTER_FREQUENCY_REAL 597 Generic timer clock source frequency if the real clock is 598 different from COUNTER_FREQUENCY, and can only be determined 599 at run time. 600 601- Tegra SoC options: 602 CONFIG_TEGRA_SUPPORT_NON_SECURE 603 604 Support executing U-Boot in non-secure (NS) mode. Certain 605 impossible actions will be skipped if the CPU is in NS mode, 606 such as ARM architectural timer initialization. 607 608- Linux Kernel Interface: 609 CONFIG_CLOCKS_IN_MHZ 610 611 U-Boot stores all clock information in Hz 612 internally. For binary compatibility with older Linux 613 kernels (which expect the clocks passed in the 614 bd_info data to be in MHz) the environment variable 615 "clocks_in_mhz" can be defined so that U-Boot 616 converts clock data to MHZ before passing it to the 617 Linux kernel. 618 When CONFIG_CLOCKS_IN_MHZ is defined, a definition of 619 "clocks_in_mhz=1" is automatically included in the 620 default environment. 621 622 CONFIG_MEMSIZE_IN_BYTES [relevant for MIPS only] 623 624 When transferring memsize parameter to Linux, some versions 625 expect it to be in bytes, others in MB. 626 Define CONFIG_MEMSIZE_IN_BYTES to make it in bytes. 627 628 CONFIG_OF_LIBFDT 629 630 New kernel versions are expecting firmware settings to be 631 passed using flattened device trees (based on open firmware 632 concepts). 633 634 CONFIG_OF_LIBFDT 635 * New libfdt-based support 636 * Adds the "fdt" command 637 * The bootm command automatically updates the fdt 638 639 OF_CPU - The proper name of the cpus node (only required for 640 MPC512X and MPC5xxx based boards). 641 OF_SOC - The proper name of the soc node (only required for 642 MPC512X and MPC5xxx based boards). 643 OF_TBCLK - The timebase frequency. 644 OF_STDOUT_PATH - The path to the console device 645 646 boards with QUICC Engines require OF_QE to set UCC MAC 647 addresses 648 649 CONFIG_OF_BOARD_SETUP 650 651 Board code has addition modification that it wants to make 652 to the flat device tree before handing it off to the kernel 653 654 CONFIG_OF_SYSTEM_SETUP 655 656 Other code has addition modification that it wants to make 657 to the flat device tree before handing it off to the kernel. 658 This causes ft_system_setup() to be called before booting 659 the kernel. 660 661 CONFIG_OF_IDE_FIXUP 662 663 U-Boot can detect if an IDE device is present or not. 664 If not, and this new config option is activated, U-Boot 665 removes the ATA node from the DTS before booting Linux, 666 so the Linux IDE driver does not probe the device and 667 crash. This is needed for buggy hardware (uc101) where 668 no pull down resistor is connected to the signal IDE5V_DD7. 669 670 CONFIG_MACH_TYPE [relevant for ARM only][mandatory] 671 672 This setting is mandatory for all boards that have only one 673 machine type and must be used to specify the machine type 674 number as it appears in the ARM machine registry 675 (see http://www.arm.linux.org.uk/developer/machines/). 676 Only boards that have multiple machine types supported 677 in a single configuration file and the machine type is 678 runtime discoverable, do not have to use this setting. 679 680- vxWorks boot parameters: 681 682 bootvx constructs a valid bootline using the following 683 environments variables: bootdev, bootfile, ipaddr, netmask, 684 serverip, gatewayip, hostname, othbootargs. 685 It loads the vxWorks image pointed bootfile. 686 687 Note: If a "bootargs" environment is defined, it will overwride 688 the defaults discussed just above. 689 690- Cache Configuration: 691 CONFIG_SYS_ICACHE_OFF - Do not enable instruction cache in U-Boot 692 CONFIG_SYS_DCACHE_OFF - Do not enable data cache in U-Boot 693 CONFIG_SYS_L2CACHE_OFF- Do not enable L2 cache in U-Boot 694 695- Cache Configuration for ARM: 696 CONFIG_SYS_L2_PL310 - Enable support for ARM PL310 L2 cache 697 controller 698 CONFIG_SYS_PL310_BASE - Physical base address of PL310 699 controller register space 700 701- Serial Ports: 702 CONFIG_PL010_SERIAL 703 704 Define this if you want support for Amba PrimeCell PL010 UARTs. 705 706 CONFIG_PL011_SERIAL 707 708 Define this if you want support for Amba PrimeCell PL011 UARTs. 709 710 CONFIG_PL011_CLOCK 711 712 If you have Amba PrimeCell PL011 UARTs, set this variable to 713 the clock speed of the UARTs. 714 715 CONFIG_PL01x_PORTS 716 717 If you have Amba PrimeCell PL010 or PL011 UARTs on your board, 718 define this to a list of base addresses for each (supported) 719 port. See e.g. include/configs/versatile.h 720 721 CONFIG_SERIAL_HW_FLOW_CONTROL 722 723 Define this variable to enable hw flow control in serial driver. 724 Current user of this option is drivers/serial/nsl16550.c driver 725 726- Console Interface: 727 Depending on board, define exactly one serial port 728 (like CONFIG_8xx_CONS_SMC1, CONFIG_8xx_CONS_SMC2, 729 CONFIG_8xx_CONS_SCC1, ...), or switch off the serial 730 console by defining CONFIG_8xx_CONS_NONE 731 732 Note: if CONFIG_8xx_CONS_NONE is defined, the serial 733 port routines must be defined elsewhere 734 (i.e. serial_init(), serial_getc(), ...) 735 736- Console Baudrate: 737 CONFIG_BAUDRATE - in bps 738 Select one of the baudrates listed in 739 CONFIG_SYS_BAUDRATE_TABLE, see below. 740 CONFIG_SYS_BRGCLK_PRESCALE, baudrate prescale 741 742- Console Rx buffer length 743 With CONFIG_SYS_SMC_RXBUFLEN it is possible to define 744 the maximum receive buffer length for the SMC. 745 This option is actual only for 82xx and 8xx possible. 746 If using CONFIG_SYS_SMC_RXBUFLEN also CONFIG_SYS_MAXIDLE 747 must be defined, to setup the maximum idle timeout for 748 the SMC. 749 750- Autoboot Command: 751 CONFIG_BOOTCOMMAND 752 Only needed when CONFIG_BOOTDELAY is enabled; 753 define a command string that is automatically executed 754 when no character is read on the console interface 755 within "Boot Delay" after reset. 756 757 CONFIG_BOOTARGS 758 This can be used to pass arguments to the bootm 759 command. The value of CONFIG_BOOTARGS goes into the 760 environment value "bootargs". 761 762 CONFIG_RAMBOOT and CONFIG_NFSBOOT 763 The value of these goes into the environment as 764 "ramboot" and "nfsboot" respectively, and can be used 765 as a convenience, when switching between booting from 766 RAM and NFS. 767 768- Bootcount: 769 CONFIG_BOOTCOUNT_LIMIT 770 Implements a mechanism for detecting a repeating reboot 771 cycle, see: 772 http://www.denx.de/wiki/view/DULG/UBootBootCountLimit 773 774 CONFIG_BOOTCOUNT_ENV 775 If no softreset save registers are found on the hardware 776 "bootcount" is stored in the environment. To prevent a 777 saveenv on all reboots, the environment variable 778 "upgrade_available" is used. If "upgrade_available" is 779 0, "bootcount" is always 0, if "upgrade_available" is 780 1 "bootcount" is incremented in the environment. 781 So the Userspace Applikation must set the "upgrade_available" 782 and "bootcount" variable to 0, if a boot was successfully. 783 784- Pre-Boot Commands: 785 CONFIG_PREBOOT 786 787 When this option is #defined, the existence of the 788 environment variable "preboot" will be checked 789 immediately before starting the CONFIG_BOOTDELAY 790 countdown and/or running the auto-boot command resp. 791 entering interactive mode. 792 793 This feature is especially useful when "preboot" is 794 automatically generated or modified. For an example 795 see the LWMON board specific code: here "preboot" is 796 modified when the user holds down a certain 797 combination of keys on the (special) keyboard when 798 booting the systems 799 800- Serial Download Echo Mode: 801 CONFIG_LOADS_ECHO 802 If defined to 1, all characters received during a 803 serial download (using the "loads" command) are 804 echoed back. This might be needed by some terminal 805 emulations (like "cu"), but may as well just take 806 time on others. This setting #define's the initial 807 value of the "loads_echo" environment variable. 808 809- Kgdb Serial Baudrate: (if CONFIG_CMD_KGDB is defined) 810 CONFIG_KGDB_BAUDRATE 811 Select one of the baudrates listed in 812 CONFIG_SYS_BAUDRATE_TABLE, see below. 813 814- Monitor Functions: 815 Monitor commands can be included or excluded 816 from the build by using the #include files 817 <config_cmd_all.h> and #undef'ing unwanted 818 commands, or adding #define's for wanted commands. 819 820 The default command configuration includes all commands 821 except those marked below with a "*". 822 823 CONFIG_CMD_AES AES 128 CBC encrypt/decrypt 824 CONFIG_CMD_ASKENV * ask for env variable 825 CONFIG_CMD_BDI bdinfo 826 CONFIG_CMD_BOOTD bootd 827 CONFIG_CMD_BOOTI * ARM64 Linux kernel Image support 828 CONFIG_CMD_CACHE * icache, dcache 829 CONFIG_CMD_CONSOLE coninfo 830 CONFIG_CMD_CRC32 * crc32 831 CONFIG_CMD_DATE * support for RTC, date/time... 832 CONFIG_CMD_DHCP * DHCP support 833 CONFIG_CMD_DIAG * Diagnostics 834 CONFIG_CMD_DS4510 * ds4510 I2C gpio commands 835 CONFIG_CMD_DS4510_INFO * ds4510 I2C info command 836 CONFIG_CMD_DS4510_MEM * ds4510 I2C eeprom/sram commansd 837 CONFIG_CMD_DS4510_RST * ds4510 I2C rst command 838 CONFIG_CMD_DTT * Digital Therm and Thermostat 839 CONFIG_CMD_ECHO echo arguments 840 CONFIG_CMD_EDITENV edit env variable 841 CONFIG_CMD_EEPROM * EEPROM read/write support 842 CONFIG_CMD_EEPROM_LAYOUT* EEPROM layout aware commands 843 CONFIG_CMD_ELF * bootelf, bootvx 844 CONFIG_CMD_ENV_CALLBACK * display details about env callbacks 845 CONFIG_CMD_ENV_FLAGS * display details about env flags 846 CONFIG_CMD_ENV_EXISTS * check existence of env variable 847 CONFIG_CMD_EXPORTENV * export the environment 848 CONFIG_CMD_EXT2 * ext2 command support 849 CONFIG_CMD_EXT4 * ext4 command support 850 CONFIG_CMD_FS_GENERIC * filesystem commands (e.g. load, ls) 851 that work for multiple fs types 852 CONFIG_CMD_FS_UUID * Look up a filesystem UUID 853 CONFIG_CMD_SAVEENV saveenv 854 CONFIG_CMD_FDC * Floppy Disk Support 855 CONFIG_CMD_FAT * FAT command support 856 CONFIG_CMD_FLASH flinfo, erase, protect 857 CONFIG_CMD_FPGA FPGA device initialization support 858 CONFIG_CMD_FUSE * Device fuse support 859 CONFIG_CMD_GETTIME * Get time since boot 860 CONFIG_CMD_GO * the 'go' command (exec code) 861 CONFIG_CMD_GREPENV * search environment 862 CONFIG_CMD_HASH * calculate hash / digest 863 CONFIG_CMD_I2C * I2C serial bus support 864 CONFIG_CMD_IDE * IDE harddisk support 865 CONFIG_CMD_IMI iminfo 866 CONFIG_CMD_IMLS List all images found in NOR flash 867 CONFIG_CMD_IMLS_NAND * List all images found in NAND flash 868 CONFIG_CMD_IMMAP * IMMR dump support 869 CONFIG_CMD_IOTRACE * I/O tracing for debugging 870 CONFIG_CMD_IMPORTENV * import an environment 871 CONFIG_CMD_INI * import data from an ini file into the env 872 CONFIG_CMD_IRQ * irqinfo 873 CONFIG_CMD_ITEST Integer/string test of 2 values 874 CONFIG_CMD_JFFS2 * JFFS2 Support 875 CONFIG_CMD_KGDB * kgdb 876 CONFIG_CMD_LDRINFO * ldrinfo (display Blackfin loader) 877 CONFIG_CMD_LINK_LOCAL * link-local IP address auto-configuration 878 (169.254.*.*) 879 CONFIG_CMD_LOADB loadb 880 CONFIG_CMD_LOADS loads 881 CONFIG_CMD_MD5SUM * print md5 message digest 882 (requires CONFIG_CMD_MEMORY and CONFIG_MD5) 883 CONFIG_CMD_MEMINFO * Display detailed memory information 884 CONFIG_CMD_MEMORY md, mm, nm, mw, cp, cmp, crc, base, 885 loop, loopw 886 CONFIG_CMD_MEMTEST * mtest 887 CONFIG_CMD_MISC Misc functions like sleep etc 888 CONFIG_CMD_MMC * MMC memory mapped support 889 CONFIG_CMD_MII * MII utility commands 890 CONFIG_CMD_MTDPARTS * MTD partition support 891 CONFIG_CMD_NAND * NAND support 892 CONFIG_CMD_NET bootp, tftpboot, rarpboot 893 CONFIG_CMD_NFS NFS support 894 CONFIG_CMD_PCA953X * PCA953x I2C gpio commands 895 CONFIG_CMD_PCA953X_INFO * PCA953x I2C gpio info command 896 CONFIG_CMD_PCI * pciinfo 897 CONFIG_CMD_PCMCIA * PCMCIA support 898 CONFIG_CMD_PING * send ICMP ECHO_REQUEST to network 899 host 900 CONFIG_CMD_PORTIO * Port I/O 901 CONFIG_CMD_READ * Read raw data from partition 902 CONFIG_CMD_REGINFO * Register dump 903 CONFIG_CMD_RUN run command in env variable 904 CONFIG_CMD_SANDBOX * sb command to access sandbox features 905 CONFIG_CMD_SAVES * save S record dump 906 CONFIG_SCSI * SCSI Support 907 CONFIG_CMD_SDRAM * print SDRAM configuration information 908 (requires CONFIG_CMD_I2C) 909 CONFIG_CMD_SETGETDCR Support for DCR Register access 910 (4xx only) 911 CONFIG_CMD_SF * Read/write/erase SPI NOR flash 912 CONFIG_CMD_SHA1SUM * print sha1 memory digest 913 (requires CONFIG_CMD_MEMORY) 914 CONFIG_CMD_SOFTSWITCH * Soft switch setting command for BF60x 915 CONFIG_CMD_SOURCE "source" command Support 916 CONFIG_CMD_SPI * SPI serial bus support 917 CONFIG_CMD_TFTPSRV * TFTP transfer in server mode 918 CONFIG_CMD_TFTPPUT * TFTP put command (upload) 919 CONFIG_CMD_TIME * run command and report execution time (ARM specific) 920 CONFIG_CMD_TIMER * access to the system tick timer 921 CONFIG_CMD_USB * USB support 922 CONFIG_CMD_CDP * Cisco Discover Protocol support 923 CONFIG_CMD_MFSL * Microblaze FSL support 924 CONFIG_CMD_XIMG Load part of Multi Image 925 CONFIG_CMD_UUID * Generate random UUID or GUID string 926 927 EXAMPLE: If you want all functions except of network 928 support you can write: 929 930 #include "config_cmd_all.h" 931 #undef CONFIG_CMD_NET 932 933 Other Commands: 934 fdt (flattened device tree) command: CONFIG_OF_LIBFDT 935 936 Note: Don't enable the "icache" and "dcache" commands 937 (configuration option CONFIG_CMD_CACHE) unless you know 938 what you (and your U-Boot users) are doing. Data 939 cache cannot be enabled on systems like the 8xx or 940 8260 (where accesses to the IMMR region must be 941 uncached), and it cannot be disabled on all other 942 systems where we (mis-) use the data cache to hold an 943 initial stack and some data. 944 945 946 XXX - this list needs to get updated! 947 948- Removal of commands 949 If no commands are needed to boot, you can disable 950 CONFIG_CMDLINE to remove them. In this case, the command line 951 will not be available, and when U-Boot wants to execute the 952 boot command (on start-up) it will call board_run_command() 953 instead. This can reduce image size significantly for very 954 simple boot procedures. 955 956- Regular expression support: 957 CONFIG_REGEX 958 If this variable is defined, U-Boot is linked against 959 the SLRE (Super Light Regular Expression) library, 960 which adds regex support to some commands, as for 961 example "env grep" and "setexpr". 962 963- Device tree: 964 CONFIG_OF_CONTROL 965 If this variable is defined, U-Boot will use a device tree 966 to configure its devices, instead of relying on statically 967 compiled #defines in the board file. This option is 968 experimental and only available on a few boards. The device 969 tree is available in the global data as gd->fdt_blob. 970 971 U-Boot needs to get its device tree from somewhere. This can 972 be done using one of the two options below: 973 974 CONFIG_OF_EMBED 975 If this variable is defined, U-Boot will embed a device tree 976 binary in its image. This device tree file should be in the 977 board directory and called <soc>-<board>.dts. The binary file 978 is then picked up in board_init_f() and made available through 979 the global data structure as gd->blob. 980 981 CONFIG_OF_SEPARATE 982 If this variable is defined, U-Boot will build a device tree 983 binary. It will be called u-boot.dtb. Architecture-specific 984 code will locate it at run-time. Generally this works by: 985 986 cat u-boot.bin u-boot.dtb >image.bin 987 988 and in fact, U-Boot does this for you, creating a file called 989 u-boot-dtb.bin which is useful in the common case. You can 990 still use the individual files if you need something more 991 exotic. 992 993- Watchdog: 994 CONFIG_WATCHDOG 995 If this variable is defined, it enables watchdog 996 support for the SoC. There must be support in the SoC 997 specific code for a watchdog. For the 8xx and 8260 998 CPUs, the SIU Watchdog feature is enabled in the SYPCR 999 register. When supported for a specific SoC is 1000 available, then no further board specific code should 1001 be needed to use it. 1002 1003 CONFIG_HW_WATCHDOG 1004 When using a watchdog circuitry external to the used 1005 SoC, then define this variable and provide board 1006 specific code for the "hw_watchdog_reset" function. 1007 1008 CONFIG_AT91_HW_WDT_TIMEOUT 1009 specify the timeout in seconds. default 2 seconds. 1010 1011- U-Boot Version: 1012 CONFIG_VERSION_VARIABLE 1013 If this variable is defined, an environment variable 1014 named "ver" is created by U-Boot showing the U-Boot 1015 version as printed by the "version" command. 1016 Any change to this variable will be reverted at the 1017 next reset. 1018 1019- Real-Time Clock: 1020 1021 When CONFIG_CMD_DATE is selected, the type of the RTC 1022 has to be selected, too. Define exactly one of the 1023 following options: 1024 1025 CONFIG_RTC_MPC8xx - use internal RTC of MPC8xx 1026 CONFIG_RTC_PCF8563 - use Philips PCF8563 RTC 1027 CONFIG_RTC_MC13XXX - use MC13783 or MC13892 RTC 1028 CONFIG_RTC_MC146818 - use MC146818 RTC 1029 CONFIG_RTC_DS1307 - use Maxim, Inc. DS1307 RTC 1030 CONFIG_RTC_DS1337 - use Maxim, Inc. DS1337 RTC 1031 CONFIG_RTC_DS1338 - use Maxim, Inc. DS1338 RTC 1032 CONFIG_RTC_DS1339 - use Maxim, Inc. DS1339 RTC 1033 CONFIG_RTC_DS164x - use Dallas DS164x RTC 1034 CONFIG_RTC_ISL1208 - use Intersil ISL1208 RTC 1035 CONFIG_RTC_MAX6900 - use Maxim, Inc. MAX6900 RTC 1036 CONFIG_SYS_RTC_DS1337_NOOSC - Turn off the OSC output for DS1337 1037 CONFIG_SYS_RV3029_TCR - enable trickle charger on 1038 RV3029 RTC. 1039 1040 Note that if the RTC uses I2C, then the I2C interface 1041 must also be configured. See I2C Support, below. 1042 1043- GPIO Support: 1044 CONFIG_PCA953X - use NXP's PCA953X series I2C GPIO 1045 1046 The CONFIG_SYS_I2C_PCA953X_WIDTH option specifies a list of 1047 chip-ngpio pairs that tell the PCA953X driver the number of 1048 pins supported by a particular chip. 1049 1050 Note that if the GPIO device uses I2C, then the I2C interface 1051 must also be configured. See I2C Support, below. 1052 1053- I/O tracing: 1054 When CONFIG_IO_TRACE is selected, U-Boot intercepts all I/O 1055 accesses and can checksum them or write a list of them out 1056 to memory. See the 'iotrace' command for details. This is 1057 useful for testing device drivers since it can confirm that 1058 the driver behaves the same way before and after a code 1059 change. Currently this is supported on sandbox and arm. To 1060 add support for your architecture, add '#include <iotrace.h>' 1061 to the bottom of arch/<arch>/include/asm/io.h and test. 1062 1063 Example output from the 'iotrace stats' command is below. 1064 Note that if the trace buffer is exhausted, the checksum will 1065 still continue to operate. 1066 1067 iotrace is enabled 1068 Start: 10000000 (buffer start address) 1069 Size: 00010000 (buffer size) 1070 Offset: 00000120 (current buffer offset) 1071 Output: 10000120 (start + offset) 1072 Count: 00000018 (number of trace records) 1073 CRC32: 9526fb66 (CRC32 of all trace records) 1074 1075- Timestamp Support: 1076 1077 When CONFIG_TIMESTAMP is selected, the timestamp 1078 (date and time) of an image is printed by image 1079 commands like bootm or iminfo. This option is 1080 automatically enabled when you select CONFIG_CMD_DATE . 1081 1082- Partition Labels (disklabels) Supported: 1083 Zero or more of the following: 1084 CONFIG_MAC_PARTITION Apple's MacOS partition table. 1085 CONFIG_DOS_PARTITION MS Dos partition table, traditional on the 1086 Intel architecture, USB sticks, etc. 1087 CONFIG_ISO_PARTITION ISO partition table, used on CDROM etc. 1088 CONFIG_EFI_PARTITION GPT partition table, common when EFI is the 1089 bootloader. Note 2TB partition limit; see 1090 disk/part_efi.c 1091 CONFIG_MTD_PARTITIONS Memory Technology Device partition table. 1092 1093 If IDE or SCSI support is enabled (CONFIG_CMD_IDE or 1094 CONFIG_SCSI) you must configure support for at 1095 least one non-MTD partition type as well. 1096 1097- IDE Reset method: 1098 CONFIG_IDE_RESET_ROUTINE - this is defined in several 1099 board configurations files but used nowhere! 1100 1101 CONFIG_IDE_RESET - is this is defined, IDE Reset will 1102 be performed by calling the function 1103 ide_set_reset(int reset) 1104 which has to be defined in a board specific file 1105 1106- ATAPI Support: 1107 CONFIG_ATAPI 1108 1109 Set this to enable ATAPI support. 1110 1111- LBA48 Support 1112 CONFIG_LBA48 1113 1114 Set this to enable support for disks larger than 137GB 1115 Also look at CONFIG_SYS_64BIT_LBA. 1116 Whithout these , LBA48 support uses 32bit variables and will 'only' 1117 support disks up to 2.1TB. 1118 1119 CONFIG_SYS_64BIT_LBA: 1120 When enabled, makes the IDE subsystem use 64bit sector addresses. 1121 Default is 32bit. 1122 1123- SCSI Support: 1124 At the moment only there is only support for the 1125 SYM53C8XX SCSI controller; define 1126 CONFIG_SCSI_SYM53C8XX to enable it. 1127 1128 CONFIG_SYS_SCSI_MAX_LUN [8], CONFIG_SYS_SCSI_MAX_SCSI_ID [7] and 1129 CONFIG_SYS_SCSI_MAX_DEVICE [CONFIG_SYS_SCSI_MAX_SCSI_ID * 1130 CONFIG_SYS_SCSI_MAX_LUN] can be adjusted to define the 1131 maximum numbers of LUNs, SCSI ID's and target 1132 devices. 1133 CONFIG_SYS_SCSI_SYM53C8XX_CCF to fix clock timing (80Mhz) 1134 1135 The environment variable 'scsidevs' is set to the number of 1136 SCSI devices found during the last scan. 1137 1138- NETWORK Support (PCI): 1139 CONFIG_E1000 1140 Support for Intel 8254x/8257x gigabit chips. 1141 1142 CONFIG_E1000_SPI 1143 Utility code for direct access to the SPI bus on Intel 8257x. 1144 This does not do anything useful unless you set at least one 1145 of CONFIG_CMD_E1000 or CONFIG_E1000_SPI_GENERIC. 1146 1147 CONFIG_E1000_SPI_GENERIC 1148 Allow generic access to the SPI bus on the Intel 8257x, for 1149 example with the "sspi" command. 1150 1151 CONFIG_CMD_E1000 1152 Management command for E1000 devices. When used on devices 1153 with SPI support you can reprogram the EEPROM from U-Boot. 1154 1155 CONFIG_EEPRO100 1156 Support for Intel 82557/82559/82559ER chips. 1157 Optional CONFIG_EEPRO100_SROM_WRITE enables EEPROM 1158 write routine for first time initialisation. 1159 1160 CONFIG_TULIP 1161 Support for Digital 2114x chips. 1162 Optional CONFIG_TULIP_SELECT_MEDIA for board specific 1163 modem chip initialisation (KS8761/QS6611). 1164 1165 CONFIG_NATSEMI 1166 Support for National dp83815 chips. 1167 1168 CONFIG_NS8382X 1169 Support for National dp8382[01] gigabit chips. 1170 1171- NETWORK Support (other): 1172 1173 CONFIG_DRIVER_AT91EMAC 1174 Support for AT91RM9200 EMAC. 1175 1176 CONFIG_RMII 1177 Define this to use reduced MII inteface 1178 1179 CONFIG_DRIVER_AT91EMAC_QUIET 1180 If this defined, the driver is quiet. 1181 The driver doen't show link status messages. 1182 1183 CONFIG_CALXEDA_XGMAC 1184 Support for the Calxeda XGMAC device 1185 1186 CONFIG_LAN91C96 1187 Support for SMSC's LAN91C96 chips. 1188 1189 CONFIG_LAN91C96_USE_32_BIT 1190 Define this to enable 32 bit addressing 1191 1192 CONFIG_SMC91111 1193 Support for SMSC's LAN91C111 chip 1194 1195 CONFIG_SMC91111_BASE 1196 Define this to hold the physical address 1197 of the device (I/O space) 1198 1199 CONFIG_SMC_USE_32_BIT 1200 Define this if data bus is 32 bits 1201 1202 CONFIG_SMC_USE_IOFUNCS 1203 Define this to use i/o functions instead of macros 1204 (some hardware wont work with macros) 1205 1206 CONFIG_DRIVER_TI_EMAC 1207 Support for davinci emac 1208 1209 CONFIG_SYS_DAVINCI_EMAC_PHY_COUNT 1210 Define this if you have more then 3 PHYs. 1211 1212 CONFIG_FTGMAC100 1213 Support for Faraday's FTGMAC100 Gigabit SoC Ethernet 1214 1215 CONFIG_FTGMAC100_EGIGA 1216 Define this to use GE link update with gigabit PHY. 1217 Define this if FTGMAC100 is connected to gigabit PHY. 1218 If your system has 10/100 PHY only, it might not occur 1219 wrong behavior. Because PHY usually return timeout or 1220 useless data when polling gigabit status and gigabit 1221 control registers. This behavior won't affect the 1222 correctnessof 10/100 link speed update. 1223 1224 CONFIG_SMC911X 1225 Support for SMSC's LAN911x and LAN921x chips 1226 1227 CONFIG_SMC911X_BASE 1228 Define this to hold the physical address 1229 of the device (I/O space) 1230 1231 CONFIG_SMC911X_32_BIT 1232 Define this if data bus is 32 bits 1233 1234 CONFIG_SMC911X_16_BIT 1235 Define this if data bus is 16 bits. If your processor 1236 automatically converts one 32 bit word to two 16 bit 1237 words you may also try CONFIG_SMC911X_32_BIT. 1238 1239 CONFIG_SH_ETHER 1240 Support for Renesas on-chip Ethernet controller 1241 1242 CONFIG_SH_ETHER_USE_PORT 1243 Define the number of ports to be used 1244 1245 CONFIG_SH_ETHER_PHY_ADDR 1246 Define the ETH PHY's address 1247 1248 CONFIG_SH_ETHER_CACHE_WRITEBACK 1249 If this option is set, the driver enables cache flush. 1250 1251- PWM Support: 1252 CONFIG_PWM_IMX 1253 Support for PWM module on the imx6. 1254 1255- TPM Support: 1256 CONFIG_TPM 1257 Support TPM devices. 1258 1259 CONFIG_TPM_TIS_INFINEON 1260 Support for Infineon i2c bus TPM devices. Only one device 1261 per system is supported at this time. 1262 1263 CONFIG_TPM_TIS_I2C_BURST_LIMITATION 1264 Define the burst count bytes upper limit 1265 1266 CONFIG_TPM_ST33ZP24 1267 Support for STMicroelectronics TPM devices. Requires DM_TPM support. 1268 1269 CONFIG_TPM_ST33ZP24_I2C 1270 Support for STMicroelectronics ST33ZP24 I2C devices. 1271 Requires TPM_ST33ZP24 and I2C. 1272 1273 CONFIG_TPM_ST33ZP24_SPI 1274 Support for STMicroelectronics ST33ZP24 SPI devices. 1275 Requires TPM_ST33ZP24 and SPI. 1276 1277 CONFIG_TPM_ATMEL_TWI 1278 Support for Atmel TWI TPM device. Requires I2C support. 1279 1280 CONFIG_TPM_TIS_LPC 1281 Support for generic parallel port TPM devices. Only one device 1282 per system is supported at this time. 1283 1284 CONFIG_TPM_TIS_BASE_ADDRESS 1285 Base address where the generic TPM device is mapped 1286 to. Contemporary x86 systems usually map it at 1287 0xfed40000. 1288 1289 CONFIG_CMD_TPM 1290 Add tpm monitor functions. 1291 Requires CONFIG_TPM. If CONFIG_TPM_AUTH_SESSIONS is set, also 1292 provides monitor access to authorized functions. 1293 1294 CONFIG_TPM 1295 Define this to enable the TPM support library which provides 1296 functional interfaces to some TPM commands. 1297 Requires support for a TPM device. 1298 1299 CONFIG_TPM_AUTH_SESSIONS 1300 Define this to enable authorized functions in the TPM library. 1301 Requires CONFIG_TPM and CONFIG_SHA1. 1302 1303- USB Support: 1304 At the moment only the UHCI host controller is 1305 supported (PIP405, MIP405, MPC5200); define 1306 CONFIG_USB_UHCI to enable it. 1307 define CONFIG_USB_KEYBOARD to enable the USB Keyboard 1308 and define CONFIG_USB_STORAGE to enable the USB 1309 storage devices. 1310 Note: 1311 Supported are USB Keyboards and USB Floppy drives 1312 (TEAC FD-05PUB). 1313 MPC5200 USB requires additional defines: 1314 CONFIG_USB_CLOCK 1315 for 528 MHz Clock: 0x0001bbbb 1316 CONFIG_PSC3_USB 1317 for USB on PSC3 1318 CONFIG_USB_CONFIG 1319 for differential drivers: 0x00001000 1320 for single ended drivers: 0x00005000 1321 for differential drivers on PSC3: 0x00000100 1322 for single ended drivers on PSC3: 0x00004100 1323 CONFIG_SYS_USB_EVENT_POLL 1324 May be defined to allow interrupt polling 1325 instead of using asynchronous interrupts 1326 1327 CONFIG_USB_EHCI_TXFIFO_THRESH enables setting of the 1328 txfilltuning field in the EHCI controller on reset. 1329 1330 CONFIG_USB_DWC2_REG_ADDR the physical CPU address of the DWC2 1331 HW module registers. 1332 1333- USB Device: 1334 Define the below if you wish to use the USB console. 1335 Once firmware is rebuilt from a serial console issue the 1336 command "setenv stdin usbtty; setenv stdout usbtty" and 1337 attach your USB cable. The Unix command "dmesg" should print 1338 it has found a new device. The environment variable usbtty 1339 can be set to gserial or cdc_acm to enable your device to 1340 appear to a USB host as a Linux gserial device or a 1341 Common Device Class Abstract Control Model serial device. 1342 If you select usbtty = gserial you should be able to enumerate 1343 a Linux host by 1344 # modprobe usbserial vendor=0xVendorID product=0xProductID 1345 else if using cdc_acm, simply setting the environment 1346 variable usbtty to be cdc_acm should suffice. The following 1347 might be defined in YourBoardName.h 1348 1349 CONFIG_USB_DEVICE 1350 Define this to build a UDC device 1351 1352 CONFIG_USB_TTY 1353 Define this to have a tty type of device available to 1354 talk to the UDC device 1355 1356 CONFIG_USBD_HS 1357 Define this to enable the high speed support for usb 1358 device and usbtty. If this feature is enabled, a routine 1359 int is_usbd_high_speed(void) 1360 also needs to be defined by the driver to dynamically poll 1361 whether the enumeration has succeded at high speed or full 1362 speed. 1363 1364 CONFIG_SYS_CONSOLE_IS_IN_ENV 1365 Define this if you want stdin, stdout &/or stderr to 1366 be set to usbtty. 1367 1368 mpc8xx: 1369 CONFIG_SYS_USB_EXTC_CLK 0xBLAH 1370 Derive USB clock from external clock "blah" 1371 - CONFIG_SYS_USB_EXTC_CLK 0x02 1372 1373 If you have a USB-IF assigned VendorID then you may wish to 1374 define your own vendor specific values either in BoardName.h 1375 or directly in usbd_vendor_info.h. If you don't define 1376 CONFIG_USBD_MANUFACTURER, CONFIG_USBD_PRODUCT_NAME, 1377 CONFIG_USBD_VENDORID and CONFIG_USBD_PRODUCTID, then U-Boot 1378 should pretend to be a Linux device to it's target host. 1379 1380 CONFIG_USBD_MANUFACTURER 1381 Define this string as the name of your company for 1382 - CONFIG_USBD_MANUFACTURER "my company" 1383 1384 CONFIG_USBD_PRODUCT_NAME 1385 Define this string as the name of your product 1386 - CONFIG_USBD_PRODUCT_NAME "acme usb device" 1387 1388 CONFIG_USBD_VENDORID 1389 Define this as your assigned Vendor ID from the USB 1390 Implementors Forum. This *must* be a genuine Vendor ID 1391 to avoid polluting the USB namespace. 1392 - CONFIG_USBD_VENDORID 0xFFFF 1393 1394 CONFIG_USBD_PRODUCTID 1395 Define this as the unique Product ID 1396 for your device 1397 - CONFIG_USBD_PRODUCTID 0xFFFF 1398 1399- ULPI Layer Support: 1400 The ULPI (UTMI Low Pin (count) Interface) PHYs are supported via 1401 the generic ULPI layer. The generic layer accesses the ULPI PHY 1402 via the platform viewport, so you need both the genric layer and 1403 the viewport enabled. Currently only Chipidea/ARC based 1404 viewport is supported. 1405 To enable the ULPI layer support, define CONFIG_USB_ULPI and 1406 CONFIG_USB_ULPI_VIEWPORT in your board configuration file. 1407 If your ULPI phy needs a different reference clock than the 1408 standard 24 MHz then you have to define CONFIG_ULPI_REF_CLK to 1409 the appropriate value in Hz. 1410 1411- MMC Support: 1412 The MMC controller on the Intel PXA is supported. To 1413 enable this define CONFIG_MMC. The MMC can be 1414 accessed from the boot prompt by mapping the device 1415 to physical memory similar to flash. Command line is 1416 enabled with CONFIG_CMD_MMC. The MMC driver also works with 1417 the FAT fs. This is enabled with CONFIG_CMD_FAT. 1418 1419 CONFIG_SH_MMCIF 1420 Support for Renesas on-chip MMCIF controller 1421 1422 CONFIG_SH_MMCIF_ADDR 1423 Define the base address of MMCIF registers 1424 1425 CONFIG_SH_MMCIF_CLK 1426 Define the clock frequency for MMCIF 1427 1428 CONFIG_SUPPORT_EMMC_BOOT 1429 Enable some additional features of the eMMC boot partitions. 1430 1431 CONFIG_SUPPORT_EMMC_RPMB 1432 Enable the commands for reading, writing and programming the 1433 key for the Replay Protection Memory Block partition in eMMC. 1434 1435- USB Device Firmware Update (DFU) class support: 1436 CONFIG_USB_FUNCTION_DFU 1437 This enables the USB portion of the DFU USB class 1438 1439 CONFIG_CMD_DFU 1440 This enables the command "dfu" which is used to have 1441 U-Boot create a DFU class device via USB. This command 1442 requires that the "dfu_alt_info" environment variable be 1443 set and define the alt settings to expose to the host. 1444 1445 CONFIG_DFU_MMC 1446 This enables support for exposing (e)MMC devices via DFU. 1447 1448 CONFIG_DFU_NAND 1449 This enables support for exposing NAND devices via DFU. 1450 1451 CONFIG_DFU_RAM 1452 This enables support for exposing RAM via DFU. 1453 Note: DFU spec refer to non-volatile memory usage, but 1454 allow usages beyond the scope of spec - here RAM usage, 1455 one that would help mostly the developer. 1456 1457 CONFIG_SYS_DFU_DATA_BUF_SIZE 1458 Dfu transfer uses a buffer before writing data to the 1459 raw storage device. Make the size (in bytes) of this buffer 1460 configurable. The size of this buffer is also configurable 1461 through the "dfu_bufsiz" environment variable. 1462 1463 CONFIG_SYS_DFU_MAX_FILE_SIZE 1464 When updating files rather than the raw storage device, 1465 we use a static buffer to copy the file into and then write 1466 the buffer once we've been given the whole file. Define 1467 this to the maximum filesize (in bytes) for the buffer. 1468 Default is 4 MiB if undefined. 1469 1470 DFU_DEFAULT_POLL_TIMEOUT 1471 Poll timeout [ms], is the timeout a device can send to the 1472 host. The host must wait for this timeout before sending 1473 a subsequent DFU_GET_STATUS request to the device. 1474 1475 DFU_MANIFEST_POLL_TIMEOUT 1476 Poll timeout [ms], which the device sends to the host when 1477 entering dfuMANIFEST state. Host waits this timeout, before 1478 sending again an USB request to the device. 1479 1480- USB Device Android Fastboot support: 1481 CONFIG_USB_FUNCTION_FASTBOOT 1482 This enables the USB part of the fastboot gadget 1483 1484 CONFIG_CMD_FASTBOOT 1485 This enables the command "fastboot" which enables the Android 1486 fastboot mode for the platform's USB device. Fastboot is a USB 1487 protocol for downloading images, flashing and device control 1488 used on Android devices. 1489 See doc/README.android-fastboot for more information. 1490 1491 CONFIG_ANDROID_BOOT_IMAGE 1492 This enables support for booting images which use the Android 1493 image format header. 1494 1495 CONFIG_FASTBOOT_BUF_ADDR 1496 The fastboot protocol requires a large memory buffer for 1497 downloads. Define this to the starting RAM address to use for 1498 downloaded images. 1499 1500 CONFIG_FASTBOOT_BUF_SIZE 1501 The fastboot protocol requires a large memory buffer for 1502 downloads. This buffer should be as large as possible for a 1503 platform. Define this to the size available RAM for fastboot. 1504 1505 CONFIG_FASTBOOT_FLASH 1506 The fastboot protocol includes a "flash" command for writing 1507 the downloaded image to a non-volatile storage device. Define 1508 this to enable the "fastboot flash" command. 1509 1510 CONFIG_FASTBOOT_FLASH_MMC_DEV 1511 The fastboot "flash" command requires additional information 1512 regarding the non-volatile storage device. Define this to 1513 the eMMC device that fastboot should use to store the image. 1514 1515 CONFIG_FASTBOOT_GPT_NAME 1516 The fastboot "flash" command supports writing the downloaded 1517 image to the Protective MBR and the Primary GUID Partition 1518 Table. (Additionally, this downloaded image is post-processed 1519 to generate and write the Backup GUID Partition Table.) 1520 This occurs when the specified "partition name" on the 1521 "fastboot flash" command line matches this value. 1522 The default is "gpt" if undefined. 1523 1524 CONFIG_FASTBOOT_MBR_NAME 1525 The fastboot "flash" command supports writing the downloaded 1526 image to DOS MBR. 1527 This occurs when the "partition name" specified on the 1528 "fastboot flash" command line matches this value. 1529 If not defined the default value "mbr" is used. 1530 1531- Journaling Flash filesystem support: 1532 CONFIG_JFFS2_NAND 1533 Define these for a default partition on a NAND device 1534 1535 CONFIG_SYS_JFFS2_FIRST_SECTOR, 1536 CONFIG_SYS_JFFS2_FIRST_BANK, CONFIG_SYS_JFFS2_NUM_BANKS 1537 Define these for a default partition on a NOR device 1538 1539- FAT(File Allocation Table) filesystem write function support: 1540 CONFIG_FAT_WRITE 1541 1542 Define this to enable support for saving memory data as a 1543 file in FAT formatted partition. 1544 1545 This will also enable the command "fatwrite" enabling the 1546 user to write files to FAT. 1547 1548- FAT(File Allocation Table) filesystem cluster size: 1549 CONFIG_FS_FAT_MAX_CLUSTSIZE 1550 1551 Define the max cluster size for fat operations else 1552 a default value of 65536 will be defined. 1553 1554- Keyboard Support: 1555 See Kconfig help for available keyboard drivers. 1556 1557 CONFIG_KEYBOARD 1558 1559 Define this to enable a custom keyboard support. 1560 This simply calls drv_keyboard_init() which must be 1561 defined in your board-specific files. This option is deprecated 1562 and is only used by novena. For new boards, use driver model 1563 instead. 1564 1565- Video support: 1566 CONFIG_FSL_DIU_FB 1567 Enable the Freescale DIU video driver. Reference boards for 1568 SOCs that have a DIU should define this macro to enable DIU 1569 support, and should also define these other macros: 1570 1571 CONFIG_SYS_DIU_ADDR 1572 CONFIG_VIDEO 1573 CONFIG_CFB_CONSOLE 1574 CONFIG_VIDEO_SW_CURSOR 1575 CONFIG_VGA_AS_SINGLE_DEVICE 1576 CONFIG_VIDEO_LOGO 1577 CONFIG_VIDEO_BMP_LOGO 1578 1579 The DIU driver will look for the 'video-mode' environment 1580 variable, and if defined, enable the DIU as a console during 1581 boot. See the documentation file doc/README.video for a 1582 description of this variable. 1583 1584- LCD Support: CONFIG_LCD 1585 1586 Define this to enable LCD support (for output to LCD 1587 display); also select one of the supported displays 1588 by defining one of these: 1589 1590 CONFIG_ATMEL_LCD: 1591 1592 HITACHI TX09D70VM1CCA, 3.5", 240x320. 1593 1594 CONFIG_NEC_NL6448AC33: 1595 1596 NEC NL6448AC33-18. Active, color, single scan. 1597 1598 CONFIG_NEC_NL6448BC20 1599 1600 NEC NL6448BC20-08. 6.5", 640x480. 1601 Active, color, single scan. 1602 1603 CONFIG_NEC_NL6448BC33_54 1604 1605 NEC NL6448BC33-54. 10.4", 640x480. 1606 Active, color, single scan. 1607 1608 CONFIG_SHARP_16x9 1609 1610 Sharp 320x240. Active, color, single scan. 1611 It isn't 16x9, and I am not sure what it is. 1612 1613 CONFIG_SHARP_LQ64D341 1614 1615 Sharp LQ64D341 display, 640x480. 1616 Active, color, single scan. 1617 1618 CONFIG_HLD1045 1619 1620 HLD1045 display, 640x480. 1621 Active, color, single scan. 1622 1623 CONFIG_OPTREX_BW 1624 1625 Optrex CBL50840-2 NF-FW 99 22 M5 1626 or 1627 Hitachi LMG6912RPFC-00T 1628 or 1629 Hitachi SP14Q002 1630 1631 320x240. Black & white. 1632 1633 CONFIG_LCD_ALIGNMENT 1634 1635 Normally the LCD is page-aligned (typically 4KB). If this is 1636 defined then the LCD will be aligned to this value instead. 1637 For ARM it is sometimes useful to use MMU_SECTION_SIZE 1638 here, since it is cheaper to change data cache settings on 1639 a per-section basis. 1640 1641 1642 CONFIG_LCD_ROTATION 1643 1644 Sometimes, for example if the display is mounted in portrait 1645 mode or even if it's mounted landscape but rotated by 180degree, 1646 we need to rotate our content of the display relative to the 1647 framebuffer, so that user can read the messages which are 1648 printed out. 1649 Once CONFIG_LCD_ROTATION is defined, the lcd_console will be 1650 initialized with a given rotation from "vl_rot" out of 1651 "vidinfo_t" which is provided by the board specific code. 1652 The value for vl_rot is coded as following (matching to 1653 fbcon=rotate:<n> linux-kernel commandline): 1654 0 = no rotation respectively 0 degree 1655 1 = 90 degree rotation 1656 2 = 180 degree rotation 1657 3 = 270 degree rotation 1658 1659 If CONFIG_LCD_ROTATION is not defined, the console will be 1660 initialized with 0degree rotation. 1661 1662 CONFIG_LCD_BMP_RLE8 1663 1664 Support drawing of RLE8-compressed bitmaps on the LCD. 1665 1666 CONFIG_I2C_EDID 1667 1668 Enables an 'i2c edid' command which can read EDID 1669 information over I2C from an attached LCD display. 1670 1671- Splash Screen Support: CONFIG_SPLASH_SCREEN 1672 1673 If this option is set, the environment is checked for 1674 a variable "splashimage". If found, the usual display 1675 of logo, copyright and system information on the LCD 1676 is suppressed and the BMP image at the address 1677 specified in "splashimage" is loaded instead. The 1678 console is redirected to the "nulldev", too. This 1679 allows for a "silent" boot where a splash screen is 1680 loaded very quickly after power-on. 1681 1682 CONFIG_SPLASHIMAGE_GUARD 1683 1684 If this option is set, then U-Boot will prevent the environment 1685 variable "splashimage" from being set to a problematic address 1686 (see doc/README.displaying-bmps). 1687 This option is useful for targets where, due to alignment 1688 restrictions, an improperly aligned BMP image will cause a data 1689 abort. If you think you will not have problems with unaligned 1690 accesses (for example because your toolchain prevents them) 1691 there is no need to set this option. 1692 1693 CONFIG_SPLASH_SCREEN_ALIGN 1694 1695 If this option is set the splash image can be freely positioned 1696 on the screen. Environment variable "splashpos" specifies the 1697 position as "x,y". If a positive number is given it is used as 1698 number of pixel from left/top. If a negative number is given it 1699 is used as number of pixel from right/bottom. You can also 1700 specify 'm' for centering the image. 1701 1702 Example: 1703 setenv splashpos m,m 1704 => image at center of screen 1705 1706 setenv splashpos 30,20 1707 => image at x = 30 and y = 20 1708 1709 setenv splashpos -10,m 1710 => vertically centered image 1711 at x = dspWidth - bmpWidth - 9 1712 1713- Gzip compressed BMP image support: CONFIG_VIDEO_BMP_GZIP 1714 1715 If this option is set, additionally to standard BMP 1716 images, gzipped BMP images can be displayed via the 1717 splashscreen support or the bmp command. 1718 1719- Run length encoded BMP image (RLE8) support: CONFIG_VIDEO_BMP_RLE8 1720 1721 If this option is set, 8-bit RLE compressed BMP images 1722 can be displayed via the splashscreen support or the 1723 bmp command. 1724 1725- Compression support: 1726 CONFIG_GZIP 1727 1728 Enabled by default to support gzip compressed images. 1729 1730 CONFIG_BZIP2 1731 1732 If this option is set, support for bzip2 compressed 1733 images is included. If not, only uncompressed and gzip 1734 compressed images are supported. 1735 1736 NOTE: the bzip2 algorithm requires a lot of RAM, so 1737 the malloc area (as defined by CONFIG_SYS_MALLOC_LEN) should 1738 be at least 4MB. 1739 1740 CONFIG_LZMA 1741 1742 If this option is set, support for lzma compressed 1743 images is included. 1744 1745 Note: The LZMA algorithm adds between 2 and 4KB of code and it 1746 requires an amount of dynamic memory that is given by the 1747 formula: 1748 1749 (1846 + 768 << (lc + lp)) * sizeof(uint16) 1750 1751 Where lc and lp stand for, respectively, Literal context bits 1752 and Literal pos bits. 1753 1754 This value is upper-bounded by 14MB in the worst case. Anyway, 1755 for a ~4MB large kernel image, we have lc=3 and lp=0 for a 1756 total amount of (1846 + 768 << (3 + 0)) * 2 = ~41KB... that is 1757 a very small buffer. 1758 1759 Use the lzmainfo tool to determinate the lc and lp values and 1760 then calculate the amount of needed dynamic memory (ensuring 1761 the appropriate CONFIG_SYS_MALLOC_LEN value). 1762 1763 CONFIG_LZO 1764 1765 If this option is set, support for LZO compressed images 1766 is included. 1767 1768- MII/PHY support: 1769 CONFIG_PHY_ADDR 1770 1771 The address of PHY on MII bus. 1772 1773 CONFIG_PHY_CLOCK_FREQ (ppc4xx) 1774 1775 The clock frequency of the MII bus 1776 1777 CONFIG_PHY_GIGE 1778 1779 If this option is set, support for speed/duplex 1780 detection of gigabit PHY is included. 1781 1782 CONFIG_PHY_RESET_DELAY 1783 1784 Some PHY like Intel LXT971A need extra delay after 1785 reset before any MII register access is possible. 1786 For such PHY, set this option to the usec delay 1787 required. (minimum 300usec for LXT971A) 1788 1789 CONFIG_PHY_CMD_DELAY (ppc4xx) 1790 1791 Some PHY like Intel LXT971A need extra delay after 1792 command issued before MII status register can be read 1793 1794- IP address: 1795 CONFIG_IPADDR 1796 1797 Define a default value for the IP address to use for 1798 the default Ethernet interface, in case this is not 1799 determined through e.g. bootp. 1800 (Environment variable "ipaddr") 1801 1802- Server IP address: 1803 CONFIG_SERVERIP 1804 1805 Defines a default value for the IP address of a TFTP 1806 server to contact when using the "tftboot" command. 1807 (Environment variable "serverip") 1808 1809 CONFIG_KEEP_SERVERADDR 1810 1811 Keeps the server's MAC address, in the env 'serveraddr' 1812 for passing to bootargs (like Linux's netconsole option) 1813 1814- Gateway IP address: 1815 CONFIG_GATEWAYIP 1816 1817 Defines a default value for the IP address of the 1818 default router where packets to other networks are 1819 sent to. 1820 (Environment variable "gatewayip") 1821 1822- Subnet mask: 1823 CONFIG_NETMASK 1824 1825 Defines a default value for the subnet mask (or 1826 routing prefix) which is used to determine if an IP 1827 address belongs to the local subnet or needs to be 1828 forwarded through a router. 1829 (Environment variable "netmask") 1830 1831- Multicast TFTP Mode: 1832 CONFIG_MCAST_TFTP 1833 1834 Defines whether you want to support multicast TFTP as per 1835 rfc-2090; for example to work with atftp. Lets lots of targets 1836 tftp down the same boot image concurrently. Note: the Ethernet 1837 driver in use must provide a function: mcast() to join/leave a 1838 multicast group. 1839 1840- BOOTP Recovery Mode: 1841 CONFIG_BOOTP_RANDOM_DELAY 1842 1843 If you have many targets in a network that try to 1844 boot using BOOTP, you may want to avoid that all 1845 systems send out BOOTP requests at precisely the same 1846 moment (which would happen for instance at recovery 1847 from a power failure, when all systems will try to 1848 boot, thus flooding the BOOTP server. Defining 1849 CONFIG_BOOTP_RANDOM_DELAY causes a random delay to be 1850 inserted before sending out BOOTP requests. The 1851 following delays are inserted then: 1852 1853 1st BOOTP request: delay 0 ... 1 sec 1854 2nd BOOTP request: delay 0 ... 2 sec 1855 3rd BOOTP request: delay 0 ... 4 sec 1856 4th and following 1857 BOOTP requests: delay 0 ... 8 sec 1858 1859 CONFIG_BOOTP_ID_CACHE_SIZE 1860 1861 BOOTP packets are uniquely identified using a 32-bit ID. The 1862 server will copy the ID from client requests to responses and 1863 U-Boot will use this to determine if it is the destination of 1864 an incoming response. Some servers will check that addresses 1865 aren't in use before handing them out (usually using an ARP 1866 ping) and therefore take up to a few hundred milliseconds to 1867 respond. Network congestion may also influence the time it 1868 takes for a response to make it back to the client. If that 1869 time is too long, U-Boot will retransmit requests. In order 1870 to allow earlier responses to still be accepted after these 1871 retransmissions, U-Boot's BOOTP client keeps a small cache of 1872 IDs. The CONFIG_BOOTP_ID_CACHE_SIZE controls the size of this 1873 cache. The default is to keep IDs for up to four outstanding 1874 requests. Increasing this will allow U-Boot to accept offers 1875 from a BOOTP client in networks with unusually high latency. 1876 1877- DHCP Advanced Options: 1878 You can fine tune the DHCP functionality by defining 1879 CONFIG_BOOTP_* symbols: 1880 1881 CONFIG_BOOTP_SUBNETMASK 1882 CONFIG_BOOTP_GATEWAY 1883 CONFIG_BOOTP_HOSTNAME 1884 CONFIG_BOOTP_NISDOMAIN 1885 CONFIG_BOOTP_BOOTPATH 1886 CONFIG_BOOTP_BOOTFILESIZE 1887 CONFIG_BOOTP_DNS 1888 CONFIG_BOOTP_DNS2 1889 CONFIG_BOOTP_SEND_HOSTNAME 1890 CONFIG_BOOTP_NTPSERVER 1891 CONFIG_BOOTP_TIMEOFFSET 1892 CONFIG_BOOTP_VENDOREX 1893 CONFIG_BOOTP_MAY_FAIL 1894 1895 CONFIG_BOOTP_SERVERIP - TFTP server will be the serverip 1896 environment variable, not the BOOTP server. 1897 1898 CONFIG_BOOTP_MAY_FAIL - If the DHCP server is not found 1899 after the configured retry count, the call will fail 1900 instead of starting over. This can be used to fail over 1901 to Link-local IP address configuration if the DHCP server 1902 is not available. 1903 1904 CONFIG_BOOTP_DNS2 - If a DHCP client requests the DNS 1905 serverip from a DHCP server, it is possible that more 1906 than one DNS serverip is offered to the client. 1907 If CONFIG_BOOTP_DNS2 is enabled, the secondary DNS 1908 serverip will be stored in the additional environment 1909 variable "dnsip2". The first DNS serverip is always 1910 stored in the variable "dnsip", when CONFIG_BOOTP_DNS 1911 is defined. 1912 1913 CONFIG_BOOTP_SEND_HOSTNAME - Some DHCP servers are capable 1914 to do a dynamic update of a DNS server. To do this, they 1915 need the hostname of the DHCP requester. 1916 If CONFIG_BOOTP_SEND_HOSTNAME is defined, the content 1917 of the "hostname" environment variable is passed as 1918 option 12 to the DHCP server. 1919 1920 CONFIG_BOOTP_DHCP_REQUEST_DELAY 1921 1922 A 32bit value in microseconds for a delay between 1923 receiving a "DHCP Offer" and sending the "DHCP Request". 1924 This fixes a problem with certain DHCP servers that don't 1925 respond 100% of the time to a "DHCP request". E.g. On an 1926 AT91RM9200 processor running at 180MHz, this delay needed 1927 to be *at least* 15,000 usec before a Windows Server 2003 1928 DHCP server would reply 100% of the time. I recommend at 1929 least 50,000 usec to be safe. The alternative is to hope 1930 that one of the retries will be successful but note that 1931 the DHCP timeout and retry process takes a longer than 1932 this delay. 1933 1934 - Link-local IP address negotiation: 1935 Negotiate with other link-local clients on the local network 1936 for an address that doesn't require explicit configuration. 1937 This is especially useful if a DHCP server cannot be guaranteed 1938 to exist in all environments that the device must operate. 1939 1940 See doc/README.link-local for more information. 1941 1942 - CDP Options: 1943 CONFIG_CDP_DEVICE_ID 1944 1945 The device id used in CDP trigger frames. 1946 1947 CONFIG_CDP_DEVICE_ID_PREFIX 1948 1949 A two character string which is prefixed to the MAC address 1950 of the device. 1951 1952 CONFIG_CDP_PORT_ID 1953 1954 A printf format string which contains the ascii name of 1955 the port. Normally is set to "eth%d" which sets 1956 eth0 for the first Ethernet, eth1 for the second etc. 1957 1958 CONFIG_CDP_CAPABILITIES 1959 1960 A 32bit integer which indicates the device capabilities; 1961 0x00000010 for a normal host which does not forwards. 1962 1963 CONFIG_CDP_VERSION 1964 1965 An ascii string containing the version of the software. 1966 1967 CONFIG_CDP_PLATFORM 1968 1969 An ascii string containing the name of the platform. 1970 1971 CONFIG_CDP_TRIGGER 1972 1973 A 32bit integer sent on the trigger. 1974 1975 CONFIG_CDP_POWER_CONSUMPTION 1976 1977 A 16bit integer containing the power consumption of the 1978 device in .1 of milliwatts. 1979 1980 CONFIG_CDP_APPLIANCE_VLAN_TYPE 1981 1982 A byte containing the id of the VLAN. 1983 1984- Status LED: CONFIG_LED_STATUS 1985 1986 Several configurations allow to display the current 1987 status using a LED. For instance, the LED will blink 1988 fast while running U-Boot code, stop blinking as 1989 soon as a reply to a BOOTP request was received, and 1990 start blinking slow once the Linux kernel is running 1991 (supported by a status LED driver in the Linux 1992 kernel). Defining CONFIG_LED_STATUS enables this 1993 feature in U-Boot. 1994 1995 Additional options: 1996 1997 CONFIG_LED_STATUS_GPIO 1998 The status LED can be connected to a GPIO pin. 1999 In such cases, the gpio_led driver can be used as a 2000 status LED backend implementation. Define CONFIG_LED_STATUS_GPIO 2001 to include the gpio_led driver in the U-Boot binary. 2002 2003 CONFIG_GPIO_LED_INVERTED_TABLE 2004 Some GPIO connected LEDs may have inverted polarity in which 2005 case the GPIO high value corresponds to LED off state and 2006 GPIO low value corresponds to LED on state. 2007 In such cases CONFIG_GPIO_LED_INVERTED_TABLE may be defined 2008 with a list of GPIO LEDs that have inverted polarity. 2009 2010- CAN Support: CONFIG_CAN_DRIVER 2011 2012 Defining CONFIG_CAN_DRIVER enables CAN driver support 2013 on those systems that support this (optional) 2014 feature, like the TQM8xxL modules. 2015 2016- I2C Support: CONFIG_SYS_I2C 2017 2018 This enable the NEW i2c subsystem, and will allow you to use 2019 i2c commands at the u-boot command line (as long as you set 2020 CONFIG_CMD_I2C in CONFIG_COMMANDS) and communicate with i2c 2021 based realtime clock chips or other i2c devices. See 2022 common/cmd_i2c.c for a description of the command line 2023 interface. 2024 2025 ported i2c driver to the new framework: 2026 - drivers/i2c/soft_i2c.c: 2027 - activate first bus with CONFIG_SYS_I2C_SOFT define 2028 CONFIG_SYS_I2C_SOFT_SPEED and CONFIG_SYS_I2C_SOFT_SLAVE 2029 for defining speed and slave address 2030 - activate second bus with I2C_SOFT_DECLARATIONS2 define 2031 CONFIG_SYS_I2C_SOFT_SPEED_2 and CONFIG_SYS_I2C_SOFT_SLAVE_2 2032 for defining speed and slave address 2033 - activate third bus with I2C_SOFT_DECLARATIONS3 define 2034 CONFIG_SYS_I2C_SOFT_SPEED_3 and CONFIG_SYS_I2C_SOFT_SLAVE_3 2035 for defining speed and slave address 2036 - activate fourth bus with I2C_SOFT_DECLARATIONS4 define 2037 CONFIG_SYS_I2C_SOFT_SPEED_4 and CONFIG_SYS_I2C_SOFT_SLAVE_4 2038 for defining speed and slave address 2039 2040 - drivers/i2c/fsl_i2c.c: 2041 - activate i2c driver with CONFIG_SYS_I2C_FSL 2042 define CONFIG_SYS_FSL_I2C_OFFSET for setting the register 2043 offset CONFIG_SYS_FSL_I2C_SPEED for the i2c speed and 2044 CONFIG_SYS_FSL_I2C_SLAVE for the slave addr of the first 2045 bus. 2046 - If your board supports a second fsl i2c bus, define 2047 CONFIG_SYS_FSL_I2C2_OFFSET for the register offset 2048 CONFIG_SYS_FSL_I2C2_SPEED for the speed and 2049 CONFIG_SYS_FSL_I2C2_SLAVE for the slave address of the 2050 second bus. 2051 2052 - drivers/i2c/tegra_i2c.c: 2053 - activate this driver with CONFIG_SYS_I2C_TEGRA 2054 - This driver adds 4 i2c buses with a fix speed from 2055 100000 and the slave addr 0! 2056 2057 - drivers/i2c/ppc4xx_i2c.c 2058 - activate this driver with CONFIG_SYS_I2C_PPC4XX 2059 - CONFIG_SYS_I2C_PPC4XX_CH0 activate hardware channel 0 2060 - CONFIG_SYS_I2C_PPC4XX_CH1 activate hardware channel 1 2061 2062 - drivers/i2c/i2c_mxc.c 2063 - activate this driver with CONFIG_SYS_I2C_MXC 2064 - enable bus 1 with CONFIG_SYS_I2C_MXC_I2C1 2065 - enable bus 2 with CONFIG_SYS_I2C_MXC_I2C2 2066 - enable bus 3 with CONFIG_SYS_I2C_MXC_I2C3 2067 - enable bus 4 with CONFIG_SYS_I2C_MXC_I2C4 2068 - define speed for bus 1 with CONFIG_SYS_MXC_I2C1_SPEED 2069 - define slave for bus 1 with CONFIG_SYS_MXC_I2C1_SLAVE 2070 - define speed for bus 2 with CONFIG_SYS_MXC_I2C2_SPEED 2071 - define slave for bus 2 with CONFIG_SYS_MXC_I2C2_SLAVE 2072 - define speed for bus 3 with CONFIG_SYS_MXC_I2C3_SPEED 2073 - define slave for bus 3 with CONFIG_SYS_MXC_I2C3_SLAVE 2074 - define speed for bus 4 with CONFIG_SYS_MXC_I2C4_SPEED 2075 - define slave for bus 4 with CONFIG_SYS_MXC_I2C4_SLAVE 2076 If those defines are not set, default value is 100000 2077 for speed, and 0 for slave. 2078 2079 - drivers/i2c/rcar_i2c.c: 2080 - activate this driver with CONFIG_SYS_I2C_RCAR 2081 - This driver adds 4 i2c buses 2082 2083 - CONFIG_SYS_RCAR_I2C0_BASE for setting the register channel 0 2084 - CONFIG_SYS_RCAR_I2C0_SPEED for for the speed channel 0 2085 - CONFIG_SYS_RCAR_I2C1_BASE for setting the register channel 1 2086 - CONFIG_SYS_RCAR_I2C1_SPEED for for the speed channel 1 2087 - CONFIG_SYS_RCAR_I2C2_BASE for setting the register channel 2 2088 - CONFIG_SYS_RCAR_I2C2_SPEED for for the speed channel 2 2089 - CONFIG_SYS_RCAR_I2C3_BASE for setting the register channel 3 2090 - CONFIG_SYS_RCAR_I2C3_SPEED for for the speed channel 3 2091 - CONFIF_SYS_RCAR_I2C_NUM_CONTROLLERS for number of i2c buses 2092 2093 - drivers/i2c/sh_i2c.c: 2094 - activate this driver with CONFIG_SYS_I2C_SH 2095 - This driver adds from 2 to 5 i2c buses 2096 2097 - CONFIG_SYS_I2C_SH_BASE0 for setting the register channel 0 2098 - CONFIG_SYS_I2C_SH_SPEED0 for for the speed channel 0 2099 - CONFIG_SYS_I2C_SH_BASE1 for setting the register channel 1 2100 - CONFIG_SYS_I2C_SH_SPEED1 for for the speed channel 1 2101 - CONFIG_SYS_I2C_SH_BASE2 for setting the register channel 2 2102 - CONFIG_SYS_I2C_SH_SPEED2 for for the speed channel 2 2103 - CONFIG_SYS_I2C_SH_BASE3 for setting the register channel 3 2104 - CONFIG_SYS_I2C_SH_SPEED3 for for the speed channel 3 2105 - CONFIG_SYS_I2C_SH_BASE4 for setting the register channel 4 2106 - CONFIG_SYS_I2C_SH_SPEED4 for for the speed channel 4 2107 - CONFIG_SYS_I2C_SH_NUM_CONTROLLERS for number of i2c buses 2108 2109 - drivers/i2c/omap24xx_i2c.c 2110 - activate this driver with CONFIG_SYS_I2C_OMAP24XX 2111 - CONFIG_SYS_OMAP24_I2C_SPEED speed channel 0 2112 - CONFIG_SYS_OMAP24_I2C_SLAVE slave addr channel 0 2113 - CONFIG_SYS_OMAP24_I2C_SPEED1 speed channel 1 2114 - CONFIG_SYS_OMAP24_I2C_SLAVE1 slave addr channel 1 2115 - CONFIG_SYS_OMAP24_I2C_SPEED2 speed channel 2 2116 - CONFIG_SYS_OMAP24_I2C_SLAVE2 slave addr channel 2 2117 - CONFIG_SYS_OMAP24_I2C_SPEED3 speed channel 3 2118 - CONFIG_SYS_OMAP24_I2C_SLAVE3 slave addr channel 3 2119 - CONFIG_SYS_OMAP24_I2C_SPEED4 speed channel 4 2120 - CONFIG_SYS_OMAP24_I2C_SLAVE4 slave addr channel 4 2121 2122 - drivers/i2c/zynq_i2c.c 2123 - activate this driver with CONFIG_SYS_I2C_ZYNQ 2124 - set CONFIG_SYS_I2C_ZYNQ_SPEED for speed setting 2125 - set CONFIG_SYS_I2C_ZYNQ_SLAVE for slave addr 2126 2127 - drivers/i2c/s3c24x0_i2c.c: 2128 - activate this driver with CONFIG_SYS_I2C_S3C24X0 2129 - This driver adds i2c buses (11 for Exynos5250, Exynos5420 2130 9 i2c buses for Exynos4 and 1 for S3C24X0 SoCs from Samsung) 2131 with a fix speed from 100000 and the slave addr 0! 2132 2133 - drivers/i2c/ihs_i2c.c 2134 - activate this driver with CONFIG_SYS_I2C_IHS 2135 - CONFIG_SYS_I2C_IHS_CH0 activate hardware channel 0 2136 - CONFIG_SYS_I2C_IHS_SPEED_0 speed channel 0 2137 - CONFIG_SYS_I2C_IHS_SLAVE_0 slave addr channel 0 2138 - CONFIG_SYS_I2C_IHS_CH1 activate hardware channel 1 2139 - CONFIG_SYS_I2C_IHS_SPEED_1 speed channel 1 2140 - CONFIG_SYS_I2C_IHS_SLAVE_1 slave addr channel 1 2141 - CONFIG_SYS_I2C_IHS_CH2 activate hardware channel 2 2142 - CONFIG_SYS_I2C_IHS_SPEED_2 speed channel 2 2143 - CONFIG_SYS_I2C_IHS_SLAVE_2 slave addr channel 2 2144 - CONFIG_SYS_I2C_IHS_CH3 activate hardware channel 3 2145 - CONFIG_SYS_I2C_IHS_SPEED_3 speed channel 3 2146 - CONFIG_SYS_I2C_IHS_SLAVE_3 slave addr channel 3 2147 - activate dual channel with CONFIG_SYS_I2C_IHS_DUAL 2148 - CONFIG_SYS_I2C_IHS_SPEED_0_1 speed channel 0_1 2149 - CONFIG_SYS_I2C_IHS_SLAVE_0_1 slave addr channel 0_1 2150 - CONFIG_SYS_I2C_IHS_SPEED_1_1 speed channel 1_1 2151 - CONFIG_SYS_I2C_IHS_SLAVE_1_1 slave addr channel 1_1 2152 - CONFIG_SYS_I2C_IHS_SPEED_2_1 speed channel 2_1 2153 - CONFIG_SYS_I2C_IHS_SLAVE_2_1 slave addr channel 2_1 2154 - CONFIG_SYS_I2C_IHS_SPEED_3_1 speed channel 3_1 2155 - CONFIG_SYS_I2C_IHS_SLAVE_3_1 slave addr channel 3_1 2156 2157 additional defines: 2158 2159 CONFIG_SYS_NUM_I2C_BUSES 2160 Hold the number of i2c buses you want to use. 2161 2162 CONFIG_SYS_I2C_DIRECT_BUS 2163 define this, if you don't use i2c muxes on your hardware. 2164 if CONFIG_SYS_I2C_MAX_HOPS is not defined or == 0 you can 2165 omit this define. 2166 2167 CONFIG_SYS_I2C_MAX_HOPS 2168 define how many muxes are maximal consecutively connected 2169 on one i2c bus. If you not use i2c muxes, omit this 2170 define. 2171 2172 CONFIG_SYS_I2C_BUSES 2173 hold a list of buses you want to use, only used if 2174 CONFIG_SYS_I2C_DIRECT_BUS is not defined, for example 2175 a board with CONFIG_SYS_I2C_MAX_HOPS = 1 and 2176 CONFIG_SYS_NUM_I2C_BUSES = 9: 2177 2178 CONFIG_SYS_I2C_BUSES {{0, {I2C_NULL_HOP}}, \ 2179 {0, {{I2C_MUX_PCA9547, 0x70, 1}}}, \ 2180 {0, {{I2C_MUX_PCA9547, 0x70, 2}}}, \ 2181 {0, {{I2C_MUX_PCA9547, 0x70, 3}}}, \ 2182 {0, {{I2C_MUX_PCA9547, 0x70, 4}}}, \ 2183 {0, {{I2C_MUX_PCA9547, 0x70, 5}}}, \ 2184 {1, {I2C_NULL_HOP}}, \ 2185 {1, {{I2C_MUX_PCA9544, 0x72, 1}}}, \ 2186 {1, {{I2C_MUX_PCA9544, 0x72, 2}}}, \ 2187 } 2188 2189 which defines 2190 bus 0 on adapter 0 without a mux 2191 bus 1 on adapter 0 with a PCA9547 on address 0x70 port 1 2192 bus 2 on adapter 0 with a PCA9547 on address 0x70 port 2 2193 bus 3 on adapter 0 with a PCA9547 on address 0x70 port 3 2194 bus 4 on adapter 0 with a PCA9547 on address 0x70 port 4 2195 bus 5 on adapter 0 with a PCA9547 on address 0x70 port 5 2196 bus 6 on adapter 1 without a mux 2197 bus 7 on adapter 1 with a PCA9544 on address 0x72 port 1 2198 bus 8 on adapter 1 with a PCA9544 on address 0x72 port 2 2199 2200 If you do not have i2c muxes on your board, omit this define. 2201 2202- Legacy I2C Support: CONFIG_HARD_I2C 2203 2204 NOTE: It is intended to move drivers to CONFIG_SYS_I2C which 2205 provides the following compelling advantages: 2206 2207 - more than one i2c adapter is usable 2208 - approved multibus support 2209 - better i2c mux support 2210 2211 ** Please consider updating your I2C driver now. ** 2212 2213 These enable legacy I2C serial bus commands. Defining 2214 CONFIG_HARD_I2C will include the appropriate I2C driver 2215 for the selected CPU. 2216 2217 This will allow you to use i2c commands at the u-boot 2218 command line (as long as you set CONFIG_CMD_I2C in 2219 CONFIG_COMMANDS) and communicate with i2c based realtime 2220 clock chips. See common/cmd_i2c.c for a description of the 2221 command line interface. 2222 2223 CONFIG_HARD_I2C selects a hardware I2C controller. 2224 2225 There are several other quantities that must also be 2226 defined when you define CONFIG_HARD_I2C. 2227 2228 In both cases you will need to define CONFIG_SYS_I2C_SPEED 2229 to be the frequency (in Hz) at which you wish your i2c bus 2230 to run and CONFIG_SYS_I2C_SLAVE to be the address of this node (ie 2231 the CPU's i2c node address). 2232 2233 Now, the u-boot i2c code for the mpc8xx 2234 (arch/powerpc/cpu/mpc8xx/i2c.c) sets the CPU up as a master node 2235 and so its address should therefore be cleared to 0 (See, 2236 eg, MPC823e User's Manual p.16-473). So, set 2237 CONFIG_SYS_I2C_SLAVE to 0. 2238 2239 CONFIG_SYS_I2C_INIT_MPC5XXX 2240 2241 When a board is reset during an i2c bus transfer 2242 chips might think that the current transfer is still 2243 in progress. Reset the slave devices by sending start 2244 commands until the slave device responds. 2245 2246 That's all that's required for CONFIG_HARD_I2C. 2247 2248 If you use the software i2c interface (CONFIG_SYS_I2C_SOFT) 2249 then the following macros need to be defined (examples are 2250 from include/configs/lwmon.h): 2251 2252 I2C_INIT 2253 2254 (Optional). Any commands necessary to enable the I2C 2255 controller or configure ports. 2256 2257 eg: #define I2C_INIT (immr->im_cpm.cp_pbdir |= PB_SCL) 2258 2259 I2C_PORT 2260 2261 (Only for MPC8260 CPU). The I/O port to use (the code 2262 assumes both bits are on the same port). Valid values 2263 are 0..3 for ports A..D. 2264 2265 I2C_ACTIVE 2266 2267 The code necessary to make the I2C data line active 2268 (driven). If the data line is open collector, this 2269 define can be null. 2270 2271 eg: #define I2C_ACTIVE (immr->im_cpm.cp_pbdir |= PB_SDA) 2272 2273 I2C_TRISTATE 2274 2275 The code necessary to make the I2C data line tri-stated 2276 (inactive). If the data line is open collector, this 2277 define can be null. 2278 2279 eg: #define I2C_TRISTATE (immr->im_cpm.cp_pbdir &= ~PB_SDA) 2280 2281 I2C_READ 2282 2283 Code that returns true if the I2C data line is high, 2284 false if it is low. 2285 2286 eg: #define I2C_READ ((immr->im_cpm.cp_pbdat & PB_SDA) != 0) 2287 2288 I2C_SDA(bit) 2289 2290 If <bit> is true, sets the I2C data line high. If it 2291 is false, it clears it (low). 2292 2293 eg: #define I2C_SDA(bit) \ 2294 if(bit) immr->im_cpm.cp_pbdat |= PB_SDA; \ 2295 else immr->im_cpm.cp_pbdat &= ~PB_SDA 2296 2297 I2C_SCL(bit) 2298 2299 If <bit> is true, sets the I2C clock line high. If it 2300 is false, it clears it (low). 2301 2302 eg: #define I2C_SCL(bit) \ 2303 if(bit) immr->im_cpm.cp_pbdat |= PB_SCL; \ 2304 else immr->im_cpm.cp_pbdat &= ~PB_SCL 2305 2306 I2C_DELAY 2307 2308 This delay is invoked four times per clock cycle so this 2309 controls the rate of data transfer. The data rate thus 2310 is 1 / (I2C_DELAY * 4). Often defined to be something 2311 like: 2312 2313 #define I2C_DELAY udelay(2) 2314 2315 CONFIG_SOFT_I2C_GPIO_SCL / CONFIG_SOFT_I2C_GPIO_SDA 2316 2317 If your arch supports the generic GPIO framework (asm/gpio.h), 2318 then you may alternatively define the two GPIOs that are to be 2319 used as SCL / SDA. Any of the previous I2C_xxx macros will 2320 have GPIO-based defaults assigned to them as appropriate. 2321 2322 You should define these to the GPIO value as given directly to 2323 the generic GPIO functions. 2324 2325 CONFIG_SYS_I2C_INIT_BOARD 2326 2327 When a board is reset during an i2c bus transfer 2328 chips might think that the current transfer is still 2329 in progress. On some boards it is possible to access 2330 the i2c SCLK line directly, either by using the 2331 processor pin as a GPIO or by having a second pin 2332 connected to the bus. If this option is defined a 2333 custom i2c_init_board() routine in boards/xxx/board.c 2334 is run early in the boot sequence. 2335 2336 CONFIG_SYS_I2C_BOARD_LATE_INIT 2337 2338 An alternative to CONFIG_SYS_I2C_INIT_BOARD. If this option is 2339 defined a custom i2c_board_late_init() routine in 2340 boards/xxx/board.c is run AFTER the operations in i2c_init() 2341 is completed. This callpoint can be used to unreset i2c bus 2342 using CPU i2c controller register accesses for CPUs whose i2c 2343 controller provide such a method. It is called at the end of 2344 i2c_init() to allow i2c_init operations to setup the i2c bus 2345 controller on the CPU (e.g. setting bus speed & slave address). 2346 2347 CONFIG_I2CFAST (PPC405GP|PPC405EP only) 2348 2349 This option enables configuration of bi_iic_fast[] flags 2350 in u-boot bd_info structure based on u-boot environment 2351 variable "i2cfast". (see also i2cfast) 2352 2353 CONFIG_I2C_MULTI_BUS 2354 2355 This option allows the use of multiple I2C buses, each of which 2356 must have a controller. At any point in time, only one bus is 2357 active. To switch to a different bus, use the 'i2c dev' command. 2358 Note that bus numbering is zero-based. 2359 2360 CONFIG_SYS_I2C_NOPROBES 2361 2362 This option specifies a list of I2C devices that will be skipped 2363 when the 'i2c probe' command is issued. If CONFIG_I2C_MULTI_BUS 2364 is set, specify a list of bus-device pairs. Otherwise, specify 2365 a 1D array of device addresses 2366 2367 e.g. 2368 #undef CONFIG_I2C_MULTI_BUS 2369 #define CONFIG_SYS_I2C_NOPROBES {0x50,0x68} 2370 2371 will skip addresses 0x50 and 0x68 on a board with one I2C bus 2372 2373 #define CONFIG_I2C_MULTI_BUS 2374 #define CONFIG_SYS_I2C_NOPROBES {{0,0x50},{0,0x68},{1,0x54}} 2375 2376 will skip addresses 0x50 and 0x68 on bus 0 and address 0x54 on bus 1 2377 2378 CONFIG_SYS_SPD_BUS_NUM 2379 2380 If defined, then this indicates the I2C bus number for DDR SPD. 2381 If not defined, then U-Boot assumes that SPD is on I2C bus 0. 2382 2383 CONFIG_SYS_RTC_BUS_NUM 2384 2385 If defined, then this indicates the I2C bus number for the RTC. 2386 If not defined, then U-Boot assumes that RTC is on I2C bus 0. 2387 2388 CONFIG_SYS_DTT_BUS_NUM 2389 2390 If defined, then this indicates the I2C bus number for the DTT. 2391 If not defined, then U-Boot assumes that DTT is on I2C bus 0. 2392 2393 CONFIG_SYS_I2C_DTT_ADDR: 2394 2395 If defined, specifies the I2C address of the DTT device. 2396 If not defined, then U-Boot uses predefined value for 2397 specified DTT device. 2398 2399 CONFIG_SOFT_I2C_READ_REPEATED_START 2400 2401 defining this will force the i2c_read() function in 2402 the soft_i2c driver to perform an I2C repeated start 2403 between writing the address pointer and reading the 2404 data. If this define is omitted the default behaviour 2405 of doing a stop-start sequence will be used. Most I2C 2406 devices can use either method, but some require one or 2407 the other. 2408 2409- SPI Support: CONFIG_SPI 2410 2411 Enables SPI driver (so far only tested with 2412 SPI EEPROM, also an instance works with Crystal A/D and 2413 D/As on the SACSng board) 2414 2415 CONFIG_SH_SPI 2416 2417 Enables the driver for SPI controller on SuperH. Currently 2418 only SH7757 is supported. 2419 2420 CONFIG_SOFT_SPI 2421 2422 Enables a software (bit-bang) SPI driver rather than 2423 using hardware support. This is a general purpose 2424 driver that only requires three general I/O port pins 2425 (two outputs, one input) to function. If this is 2426 defined, the board configuration must define several 2427 SPI configuration items (port pins to use, etc). For 2428 an example, see include/configs/sacsng.h. 2429 2430 CONFIG_HARD_SPI 2431 2432 Enables a hardware SPI driver for general-purpose reads 2433 and writes. As with CONFIG_SOFT_SPI, the board configuration 2434 must define a list of chip-select function pointers. 2435 Currently supported on some MPC8xxx processors. For an 2436 example, see include/configs/mpc8349emds.h. 2437 2438 CONFIG_MXC_SPI 2439 2440 Enables the driver for the SPI controllers on i.MX and MXC 2441 SoCs. Currently i.MX31/35/51 are supported. 2442 2443 CONFIG_SYS_SPI_MXC_WAIT 2444 Timeout for waiting until spi transfer completed. 2445 default: (CONFIG_SYS_HZ/100) /* 10 ms */ 2446 2447- FPGA Support: CONFIG_FPGA 2448 2449 Enables FPGA subsystem. 2450 2451 CONFIG_FPGA_<vendor> 2452 2453 Enables support for specific chip vendors. 2454 (ALTERA, XILINX) 2455 2456 CONFIG_FPGA_<family> 2457 2458 Enables support for FPGA family. 2459 (SPARTAN2, SPARTAN3, VIRTEX2, CYCLONE2, ACEX1K, ACEX) 2460 2461 CONFIG_FPGA_COUNT 2462 2463 Specify the number of FPGA devices to support. 2464 2465 CONFIG_CMD_FPGA_LOADMK 2466 2467 Enable support for fpga loadmk command 2468 2469 CONFIG_CMD_FPGA_LOADP 2470 2471 Enable support for fpga loadp command - load partial bitstream 2472 2473 CONFIG_CMD_FPGA_LOADBP 2474 2475 Enable support for fpga loadbp command - load partial bitstream 2476 (Xilinx only) 2477 2478 CONFIG_SYS_FPGA_PROG_FEEDBACK 2479 2480 Enable printing of hash marks during FPGA configuration. 2481 2482 CONFIG_SYS_FPGA_CHECK_BUSY 2483 2484 Enable checks on FPGA configuration interface busy 2485 status by the configuration function. This option 2486 will require a board or device specific function to 2487 be written. 2488 2489 CONFIG_FPGA_DELAY 2490 2491 If defined, a function that provides delays in the FPGA 2492 configuration driver. 2493 2494 CONFIG_SYS_FPGA_CHECK_CTRLC 2495 Allow Control-C to interrupt FPGA configuration 2496 2497 CONFIG_SYS_FPGA_CHECK_ERROR 2498 2499 Check for configuration errors during FPGA bitfile 2500 loading. For example, abort during Virtex II 2501 configuration if the INIT_B line goes low (which 2502 indicated a CRC error). 2503 2504 CONFIG_SYS_FPGA_WAIT_INIT 2505 2506 Maximum time to wait for the INIT_B line to de-assert 2507 after PROB_B has been de-asserted during a Virtex II 2508 FPGA configuration sequence. The default time is 500 2509 ms. 2510 2511 CONFIG_SYS_FPGA_WAIT_BUSY 2512 2513 Maximum time to wait for BUSY to de-assert during 2514 Virtex II FPGA configuration. The default is 5 ms. 2515 2516 CONFIG_SYS_FPGA_WAIT_CONFIG 2517 2518 Time to wait after FPGA configuration. The default is 2519 200 ms. 2520 2521- Configuration Management: 2522 CONFIG_BUILD_TARGET 2523 2524 Some SoCs need special image types (e.g. U-Boot binary 2525 with a special header) as build targets. By defining 2526 CONFIG_BUILD_TARGET in the SoC / board header, this 2527 special image will be automatically built upon calling 2528 make / buildman. 2529 2530 CONFIG_IDENT_STRING 2531 2532 If defined, this string will be added to the U-Boot 2533 version information (U_BOOT_VERSION) 2534 2535- Vendor Parameter Protection: 2536 2537 U-Boot considers the values of the environment 2538 variables "serial#" (Board Serial Number) and 2539 "ethaddr" (Ethernet Address) to be parameters that 2540 are set once by the board vendor / manufacturer, and 2541 protects these variables from casual modification by 2542 the user. Once set, these variables are read-only, 2543 and write or delete attempts are rejected. You can 2544 change this behaviour: 2545 2546 If CONFIG_ENV_OVERWRITE is #defined in your config 2547 file, the write protection for vendor parameters is 2548 completely disabled. Anybody can change or delete 2549 these parameters. 2550 2551 Alternatively, if you define _both_ an ethaddr in the 2552 default env _and_ CONFIG_OVERWRITE_ETHADDR_ONCE, a default 2553 Ethernet address is installed in the environment, 2554 which can be changed exactly ONCE by the user. [The 2555 serial# is unaffected by this, i. e. it remains 2556 read-only.] 2557 2558 The same can be accomplished in a more flexible way 2559 for any variable by configuring the type of access 2560 to allow for those variables in the ".flags" variable 2561 or define CONFIG_ENV_FLAGS_LIST_STATIC. 2562 2563- Protected RAM: 2564 CONFIG_PRAM 2565 2566 Define this variable to enable the reservation of 2567 "protected RAM", i. e. RAM which is not overwritten 2568 by U-Boot. Define CONFIG_PRAM to hold the number of 2569 kB you want to reserve for pRAM. You can overwrite 2570 this default value by defining an environment 2571 variable "pram" to the number of kB you want to 2572 reserve. Note that the board info structure will 2573 still show the full amount of RAM. If pRAM is 2574 reserved, a new environment variable "mem" will 2575 automatically be defined to hold the amount of 2576 remaining RAM in a form that can be passed as boot 2577 argument to Linux, for instance like that: 2578 2579 setenv bootargs ... mem=\${mem} 2580 saveenv 2581 2582 This way you can tell Linux not to use this memory, 2583 either, which results in a memory region that will 2584 not be affected by reboots. 2585 2586 *WARNING* If your board configuration uses automatic 2587 detection of the RAM size, you must make sure that 2588 this memory test is non-destructive. So far, the 2589 following board configurations are known to be 2590 "pRAM-clean": 2591 2592 IVMS8, IVML24, SPD8xx, TQM8xxL, 2593 HERMES, IP860, RPXlite, LWMON, 2594 FLAGADM, TQM8260 2595 2596- Access to physical memory region (> 4GB) 2597 Some basic support is provided for operations on memory not 2598 normally accessible to U-Boot - e.g. some architectures 2599 support access to more than 4GB of memory on 32-bit 2600 machines using physical address extension or similar. 2601 Define CONFIG_PHYSMEM to access this basic support, which 2602 currently only supports clearing the memory. 2603 2604- Error Recovery: 2605 CONFIG_PANIC_HANG 2606 2607 Define this variable to stop the system in case of a 2608 fatal error, so that you have to reset it manually. 2609 This is probably NOT a good idea for an embedded 2610 system where you want the system to reboot 2611 automatically as fast as possible, but it may be 2612 useful during development since you can try to debug 2613 the conditions that lead to the situation. 2614 2615 CONFIG_NET_RETRY_COUNT 2616 2617 This variable defines the number of retries for 2618 network operations like ARP, RARP, TFTP, or BOOTP 2619 before giving up the operation. If not defined, a 2620 default value of 5 is used. 2621 2622 CONFIG_ARP_TIMEOUT 2623 2624 Timeout waiting for an ARP reply in milliseconds. 2625 2626 CONFIG_NFS_TIMEOUT 2627 2628 Timeout in milliseconds used in NFS protocol. 2629 If you encounter "ERROR: Cannot umount" in nfs command, 2630 try longer timeout such as 2631 #define CONFIG_NFS_TIMEOUT 10000UL 2632 2633- Command Interpreter: 2634 CONFIG_AUTO_COMPLETE 2635 2636 Enable auto completion of commands using TAB. 2637 2638 CONFIG_SYS_PROMPT_HUSH_PS2 2639 2640 This defines the secondary prompt string, which is 2641 printed when the command interpreter needs more input 2642 to complete a command. Usually "> ". 2643 2644 Note: 2645 2646 In the current implementation, the local variables 2647 space and global environment variables space are 2648 separated. Local variables are those you define by 2649 simply typing `name=value'. To access a local 2650 variable later on, you have write `$name' or 2651 `${name}'; to execute the contents of a variable 2652 directly type `$name' at the command prompt. 2653 2654 Global environment variables are those you use 2655 setenv/printenv to work with. To run a command stored 2656 in such a variable, you need to use the run command, 2657 and you must not use the '$' sign to access them. 2658 2659 To store commands and special characters in a 2660 variable, please use double quotation marks 2661 surrounding the whole text of the variable, instead 2662 of the backslashes before semicolons and special 2663 symbols. 2664 2665- Command Line Editing and History: 2666 CONFIG_CMDLINE_EDITING 2667 2668 Enable editing and History functions for interactive 2669 command line input operations 2670 2671- Command Line PS1/PS2 support: 2672 CONFIG_CMDLINE_PS_SUPPORT 2673 2674 Enable support for changing the command prompt string 2675 at run-time. Only static string is supported so far. 2676 The string is obtained from environment variables PS1 2677 and PS2. 2678 2679- Default Environment: 2680 CONFIG_EXTRA_ENV_SETTINGS 2681 2682 Define this to contain any number of null terminated 2683 strings (variable = value pairs) that will be part of 2684 the default environment compiled into the boot image. 2685 2686 For example, place something like this in your 2687 board's config file: 2688 2689 #define CONFIG_EXTRA_ENV_SETTINGS \ 2690 "myvar1=value1\0" \ 2691 "myvar2=value2\0" 2692 2693 Warning: This method is based on knowledge about the 2694 internal format how the environment is stored by the 2695 U-Boot code. This is NOT an official, exported 2696 interface! Although it is unlikely that this format 2697 will change soon, there is no guarantee either. 2698 You better know what you are doing here. 2699 2700 Note: overly (ab)use of the default environment is 2701 discouraged. Make sure to check other ways to preset 2702 the environment like the "source" command or the 2703 boot command first. 2704 2705 CONFIG_ENV_VARS_UBOOT_CONFIG 2706 2707 Define this in order to add variables describing the 2708 U-Boot build configuration to the default environment. 2709 These will be named arch, cpu, board, vendor, and soc. 2710 2711 Enabling this option will cause the following to be defined: 2712 2713 - CONFIG_SYS_ARCH 2714 - CONFIG_SYS_CPU 2715 - CONFIG_SYS_BOARD 2716 - CONFIG_SYS_VENDOR 2717 - CONFIG_SYS_SOC 2718 2719 CONFIG_ENV_VARS_UBOOT_RUNTIME_CONFIG 2720 2721 Define this in order to add variables describing certain 2722 run-time determined information about the hardware to the 2723 environment. These will be named board_name, board_rev. 2724 2725 CONFIG_DELAY_ENVIRONMENT 2726 2727 Normally the environment is loaded when the board is 2728 initialised so that it is available to U-Boot. This inhibits 2729 that so that the environment is not available until 2730 explicitly loaded later by U-Boot code. With CONFIG_OF_CONTROL 2731 this is instead controlled by the value of 2732 /config/load-environment. 2733 2734- DataFlash Support: 2735 CONFIG_HAS_DATAFLASH 2736 2737 Defining this option enables DataFlash features and 2738 allows to read/write in Dataflash via the standard 2739 commands cp, md... 2740 2741- Serial Flash support 2742 CONFIG_CMD_SF 2743 2744 Defining this option enables SPI flash commands 2745 'sf probe/read/write/erase/update'. 2746 2747 Usage requires an initial 'probe' to define the serial 2748 flash parameters, followed by read/write/erase/update 2749 commands. 2750 2751 The following defaults may be provided by the platform 2752 to handle the common case when only a single serial 2753 flash is present on the system. 2754 2755 CONFIG_SF_DEFAULT_BUS Bus identifier 2756 CONFIG_SF_DEFAULT_CS Chip-select 2757 CONFIG_SF_DEFAULT_MODE (see include/spi.h) 2758 CONFIG_SF_DEFAULT_SPEED in Hz 2759 2760 CONFIG_CMD_SF_TEST 2761 2762 Define this option to include a destructive SPI flash 2763 test ('sf test'). 2764 2765 CONFIG_SF_DUAL_FLASH Dual flash memories 2766 2767 Define this option to use dual flash support where two flash 2768 memories can be connected with a given cs line. 2769 Currently Xilinx Zynq qspi supports these type of connections. 2770 2771- SystemACE Support: 2772 CONFIG_SYSTEMACE 2773 2774 Adding this option adds support for Xilinx SystemACE 2775 chips attached via some sort of local bus. The address 2776 of the chip must also be defined in the 2777 CONFIG_SYS_SYSTEMACE_BASE macro. For example: 2778 2779 #define CONFIG_SYSTEMACE 2780 #define CONFIG_SYS_SYSTEMACE_BASE 0xf0000000 2781 2782 When SystemACE support is added, the "ace" device type 2783 becomes available to the fat commands, i.e. fatls. 2784 2785- TFTP Fixed UDP Port: 2786 CONFIG_TFTP_PORT 2787 2788 If this is defined, the environment variable tftpsrcp 2789 is used to supply the TFTP UDP source port value. 2790 If tftpsrcp isn't defined, the normal pseudo-random port 2791 number generator is used. 2792 2793 Also, the environment variable tftpdstp is used to supply 2794 the TFTP UDP destination port value. If tftpdstp isn't 2795 defined, the normal port 69 is used. 2796 2797 The purpose for tftpsrcp is to allow a TFTP server to 2798 blindly start the TFTP transfer using the pre-configured 2799 target IP address and UDP port. This has the effect of 2800 "punching through" the (Windows XP) firewall, allowing 2801 the remainder of the TFTP transfer to proceed normally. 2802 A better solution is to properly configure the firewall, 2803 but sometimes that is not allowed. 2804 2805- Hashing support: 2806 CONFIG_CMD_HASH 2807 2808 This enables a generic 'hash' command which can produce 2809 hashes / digests from a few algorithms (e.g. SHA1, SHA256). 2810 2811 CONFIG_HASH_VERIFY 2812 2813 Enable the hash verify command (hash -v). This adds to code 2814 size a little. 2815 2816 CONFIG_SHA1 - This option enables support of hashing using SHA1 2817 algorithm. The hash is calculated in software. 2818 CONFIG_SHA256 - This option enables support of hashing using 2819 SHA256 algorithm. The hash is calculated in software. 2820 CONFIG_SHA_HW_ACCEL - This option enables hardware acceleration 2821 for SHA1/SHA256 hashing. 2822 This affects the 'hash' command and also the 2823 hash_lookup_algo() function. 2824 CONFIG_SHA_PROG_HW_ACCEL - This option enables 2825 hardware-acceleration for SHA1/SHA256 progressive hashing. 2826 Data can be streamed in a block at a time and the hashing 2827 is performed in hardware. 2828 2829 Note: There is also a sha1sum command, which should perhaps 2830 be deprecated in favour of 'hash sha1'. 2831 2832- Freescale i.MX specific commands: 2833 CONFIG_CMD_HDMIDETECT 2834 This enables 'hdmidet' command which returns true if an 2835 HDMI monitor is detected. This command is i.MX 6 specific. 2836 2837- bootcount support: 2838 CONFIG_BOOTCOUNT_LIMIT 2839 2840 This enables the bootcounter support, see: 2841 http://www.denx.de/wiki/DULG/UBootBootCountLimit 2842 2843 CONFIG_AT91SAM9XE 2844 enable special bootcounter support on at91sam9xe based boards. 2845 CONFIG_SOC_DA8XX 2846 enable special bootcounter support on da850 based boards. 2847 CONFIG_BOOTCOUNT_RAM 2848 enable support for the bootcounter in RAM 2849 CONFIG_BOOTCOUNT_I2C 2850 enable support for the bootcounter on an i2c (like RTC) device. 2851 CONFIG_SYS_I2C_RTC_ADDR = i2c chip address 2852 CONFIG_SYS_BOOTCOUNT_ADDR = i2c addr which is used for 2853 the bootcounter. 2854 CONFIG_BOOTCOUNT_ALEN = address len 2855 2856- Show boot progress: 2857 CONFIG_SHOW_BOOT_PROGRESS 2858 2859 Defining this option allows to add some board- 2860 specific code (calling a user-provided function 2861 "show_boot_progress(int)") that enables you to show 2862 the system's boot progress on some display (for 2863 example, some LED's) on your board. At the moment, 2864 the following checkpoints are implemented: 2865 2866 2867Legacy uImage format: 2868 2869 Arg Where When 2870 1 common/cmd_bootm.c before attempting to boot an image 2871 -1 common/cmd_bootm.c Image header has bad magic number 2872 2 common/cmd_bootm.c Image header has correct magic number 2873 -2 common/cmd_bootm.c Image header has bad checksum 2874 3 common/cmd_bootm.c Image header has correct checksum 2875 -3 common/cmd_bootm.c Image data has bad checksum 2876 4 common/cmd_bootm.c Image data has correct checksum 2877 -4 common/cmd_bootm.c Image is for unsupported architecture 2878 5 common/cmd_bootm.c Architecture check OK 2879 -5 common/cmd_bootm.c Wrong Image Type (not kernel, multi) 2880 6 common/cmd_bootm.c Image Type check OK 2881 -6 common/cmd_bootm.c gunzip uncompression error 2882 -7 common/cmd_bootm.c Unimplemented compression type 2883 7 common/cmd_bootm.c Uncompression OK 2884 8 common/cmd_bootm.c No uncompress/copy overwrite error 2885 -9 common/cmd_bootm.c Unsupported OS (not Linux, BSD, VxWorks, QNX) 2886 2887 9 common/image.c Start initial ramdisk verification 2888 -10 common/image.c Ramdisk header has bad magic number 2889 -11 common/image.c Ramdisk header has bad checksum 2890 10 common/image.c Ramdisk header is OK 2891 -12 common/image.c Ramdisk data has bad checksum 2892 11 common/image.c Ramdisk data has correct checksum 2893 12 common/image.c Ramdisk verification complete, start loading 2894 -13 common/image.c Wrong Image Type (not PPC Linux ramdisk) 2895 13 common/image.c Start multifile image verification 2896 14 common/image.c No initial ramdisk, no multifile, continue. 2897 2898 15 arch/<arch>/lib/bootm.c All preparation done, transferring control to OS 2899 2900 -30 arch/powerpc/lib/board.c Fatal error, hang the system 2901 -31 post/post.c POST test failed, detected by post_output_backlog() 2902 -32 post/post.c POST test failed, detected by post_run_single() 2903 2904 34 common/cmd_doc.c before loading a Image from a DOC device 2905 -35 common/cmd_doc.c Bad usage of "doc" command 2906 35 common/cmd_doc.c correct usage of "doc" command 2907 -36 common/cmd_doc.c No boot device 2908 36 common/cmd_doc.c correct boot device 2909 -37 common/cmd_doc.c Unknown Chip ID on boot device 2910 37 common/cmd_doc.c correct chip ID found, device available 2911 -38 common/cmd_doc.c Read Error on boot device 2912 38 common/cmd_doc.c reading Image header from DOC device OK 2913 -39 common/cmd_doc.c Image header has bad magic number 2914 39 common/cmd_doc.c Image header has correct magic number 2915 -40 common/cmd_doc.c Error reading Image from DOC device 2916 40 common/cmd_doc.c Image header has correct magic number 2917 41 common/cmd_ide.c before loading a Image from a IDE device 2918 -42 common/cmd_ide.c Bad usage of "ide" command 2919 42 common/cmd_ide.c correct usage of "ide" command 2920 -43 common/cmd_ide.c No boot device 2921 43 common/cmd_ide.c boot device found 2922 -44 common/cmd_ide.c Device not available 2923 44 common/cmd_ide.c Device available 2924 -45 common/cmd_ide.c wrong partition selected 2925 45 common/cmd_ide.c partition selected 2926 -46 common/cmd_ide.c Unknown partition table 2927 46 common/cmd_ide.c valid partition table found 2928 -47 common/cmd_ide.c Invalid partition type 2929 47 common/cmd_ide.c correct partition type 2930 -48 common/cmd_ide.c Error reading Image Header on boot device 2931 48 common/cmd_ide.c reading Image Header from IDE device OK 2932 -49 common/cmd_ide.c Image header has bad magic number 2933 49 common/cmd_ide.c Image header has correct magic number 2934 -50 common/cmd_ide.c Image header has bad checksum 2935 50 common/cmd_ide.c Image header has correct checksum 2936 -51 common/cmd_ide.c Error reading Image from IDE device 2937 51 common/cmd_ide.c reading Image from IDE device OK 2938 52 common/cmd_nand.c before loading a Image from a NAND device 2939 -53 common/cmd_nand.c Bad usage of "nand" command 2940 53 common/cmd_nand.c correct usage of "nand" command 2941 -54 common/cmd_nand.c No boot device 2942 54 common/cmd_nand.c boot device found 2943 -55 common/cmd_nand.c Unknown Chip ID on boot device 2944 55 common/cmd_nand.c correct chip ID found, device available 2945 -56 common/cmd_nand.c Error reading Image Header on boot device 2946 56 common/cmd_nand.c reading Image Header from NAND device OK 2947 -57 common/cmd_nand.c Image header has bad magic number 2948 57 common/cmd_nand.c Image header has correct magic number 2949 -58 common/cmd_nand.c Error reading Image from NAND device 2950 58 common/cmd_nand.c reading Image from NAND device OK 2951 2952 -60 common/env_common.c Environment has a bad CRC, using default 2953 2954 64 net/eth.c starting with Ethernet configuration. 2955 -64 net/eth.c no Ethernet found. 2956 65 net/eth.c Ethernet found. 2957 2958 -80 common/cmd_net.c usage wrong 2959 80 common/cmd_net.c before calling net_loop() 2960 -81 common/cmd_net.c some error in net_loop() occurred 2961 81 common/cmd_net.c net_loop() back without error 2962 -82 common/cmd_net.c size == 0 (File with size 0 loaded) 2963 82 common/cmd_net.c trying automatic boot 2964 83 common/cmd_net.c running "source" command 2965 -83 common/cmd_net.c some error in automatic boot or "source" command 2966 84 common/cmd_net.c end without errors 2967 2968FIT uImage format: 2969 2970 Arg Where When 2971 100 common/cmd_bootm.c Kernel FIT Image has correct format 2972 -100 common/cmd_bootm.c Kernel FIT Image has incorrect format 2973 101 common/cmd_bootm.c No Kernel subimage unit name, using configuration 2974 -101 common/cmd_bootm.c Can't get configuration for kernel subimage 2975 102 common/cmd_bootm.c Kernel unit name specified 2976 -103 common/cmd_bootm.c Can't get kernel subimage node offset 2977 103 common/cmd_bootm.c Found configuration node 2978 104 common/cmd_bootm.c Got kernel subimage node offset 2979 -104 common/cmd_bootm.c Kernel subimage hash verification failed 2980 105 common/cmd_bootm.c Kernel subimage hash verification OK 2981 -105 common/cmd_bootm.c Kernel subimage is for unsupported architecture 2982 106 common/cmd_bootm.c Architecture check OK 2983 -106 common/cmd_bootm.c Kernel subimage has wrong type 2984 107 common/cmd_bootm.c Kernel subimage type OK 2985 -107 common/cmd_bootm.c Can't get kernel subimage data/size 2986 108 common/cmd_bootm.c Got kernel subimage data/size 2987 -108 common/cmd_bootm.c Wrong image type (not legacy, FIT) 2988 -109 common/cmd_bootm.c Can't get kernel subimage type 2989 -110 common/cmd_bootm.c Can't get kernel subimage comp 2990 -111 common/cmd_bootm.c Can't get kernel subimage os 2991 -112 common/cmd_bootm.c Can't get kernel subimage load address 2992 -113 common/cmd_bootm.c Image uncompress/copy overwrite error 2993 2994 120 common/image.c Start initial ramdisk verification 2995 -120 common/image.c Ramdisk FIT image has incorrect format 2996 121 common/image.c Ramdisk FIT image has correct format 2997 122 common/image.c No ramdisk subimage unit name, using configuration 2998 -122 common/image.c Can't get configuration for ramdisk subimage 2999 123 common/image.c Ramdisk unit name specified 3000 -124 common/image.c Can't get ramdisk subimage node offset 3001 125 common/image.c Got ramdisk subimage node offset 3002 -125 common/image.c Ramdisk subimage hash verification failed 3003 126 common/image.c Ramdisk subimage hash verification OK 3004 -126 common/image.c Ramdisk subimage for unsupported architecture 3005 127 common/image.c Architecture check OK 3006 -127 common/image.c Can't get ramdisk subimage data/size 3007 128 common/image.c Got ramdisk subimage data/size 3008 129 common/image.c Can't get ramdisk load address 3009 -129 common/image.c Got ramdisk load address 3010 3011 -130 common/cmd_doc.c Incorrect FIT image format 3012 131 common/cmd_doc.c FIT image format OK 3013 3014 -140 common/cmd_ide.c Incorrect FIT image format 3015 141 common/cmd_ide.c FIT image format OK 3016 3017 -150 common/cmd_nand.c Incorrect FIT image format 3018 151 common/cmd_nand.c FIT image format OK 3019 3020- legacy image format: 3021 CONFIG_IMAGE_FORMAT_LEGACY 3022 enables the legacy image format support in U-Boot. 3023 3024 Default: 3025 enabled if CONFIG_FIT_SIGNATURE is not defined. 3026 3027 CONFIG_DISABLE_IMAGE_LEGACY 3028 disable the legacy image format 3029 3030 This define is introduced, as the legacy image format is 3031 enabled per default for backward compatibility. 3032 3033- FIT image support: 3034 CONFIG_FIT_DISABLE_SHA256 3035 Supporting SHA256 hashes has quite an impact on binary size. 3036 For constrained systems sha256 hash support can be disabled 3037 with this option. 3038 3039 TODO(sjg@chromium.org): Adjust this option to be positive, 3040 and move it to Kconfig 3041 3042- Standalone program support: 3043 CONFIG_STANDALONE_LOAD_ADDR 3044 3045 This option defines a board specific value for the 3046 address where standalone program gets loaded, thus 3047 overwriting the architecture dependent default 3048 settings. 3049 3050- Frame Buffer Address: 3051 CONFIG_FB_ADDR 3052 3053 Define CONFIG_FB_ADDR if you want to use specific 3054 address for frame buffer. This is typically the case 3055 when using a graphics controller has separate video 3056 memory. U-Boot will then place the frame buffer at 3057 the given address instead of dynamically reserving it 3058 in system RAM by calling lcd_setmem(), which grabs 3059 the memory for the frame buffer depending on the 3060 configured panel size. 3061 3062 Please see board_init_f function. 3063 3064- Automatic software updates via TFTP server 3065 CONFIG_UPDATE_TFTP 3066 CONFIG_UPDATE_TFTP_CNT_MAX 3067 CONFIG_UPDATE_TFTP_MSEC_MAX 3068 3069 These options enable and control the auto-update feature; 3070 for a more detailed description refer to doc/README.update. 3071 3072- MTD Support (mtdparts command, UBI support) 3073 CONFIG_MTD_DEVICE 3074 3075 Adds the MTD device infrastructure from the Linux kernel. 3076 Needed for mtdparts command support. 3077 3078 CONFIG_MTD_PARTITIONS 3079 3080 Adds the MTD partitioning infrastructure from the Linux 3081 kernel. Needed for UBI support. 3082 3083- UBI support 3084 CONFIG_CMD_UBI 3085 3086 Adds commands for interacting with MTD partitions formatted 3087 with the UBI flash translation layer 3088 3089 Requires also defining CONFIG_RBTREE 3090 3091 CONFIG_UBI_SILENCE_MSG 3092 3093 Make the verbose messages from UBI stop printing. This leaves 3094 warnings and errors enabled. 3095 3096 3097 CONFIG_MTD_UBI_WL_THRESHOLD 3098 This parameter defines the maximum difference between the highest 3099 erase counter value and the lowest erase counter value of eraseblocks 3100 of UBI devices. When this threshold is exceeded, UBI starts performing 3101 wear leveling by means of moving data from eraseblock with low erase 3102 counter to eraseblocks with high erase counter. 3103 3104 The default value should be OK for SLC NAND flashes, NOR flashes and 3105 other flashes which have eraseblock life-cycle 100000 or more. 3106 However, in case of MLC NAND flashes which typically have eraseblock 3107 life-cycle less than 10000, the threshold should be lessened (e.g., 3108 to 128 or 256, although it does not have to be power of 2). 3109 3110 default: 4096 3111 3112 CONFIG_MTD_UBI_BEB_LIMIT 3113 This option specifies the maximum bad physical eraseblocks UBI 3114 expects on the MTD device (per 1024 eraseblocks). If the 3115 underlying flash does not admit of bad eraseblocks (e.g. NOR 3116 flash), this value is ignored. 3117 3118 NAND datasheets often specify the minimum and maximum NVM 3119 (Number of Valid Blocks) for the flashes' endurance lifetime. 3120 The maximum expected bad eraseblocks per 1024 eraseblocks 3121 then can be calculated as "1024 * (1 - MinNVB / MaxNVB)", 3122 which gives 20 for most NANDs (MaxNVB is basically the total 3123 count of eraseblocks on the chip). 3124 3125 To put it differently, if this value is 20, UBI will try to 3126 reserve about 1.9% of physical eraseblocks for bad blocks 3127 handling. And that will be 1.9% of eraseblocks on the entire 3128 NAND chip, not just the MTD partition UBI attaches. This means 3129 that if you have, say, a NAND flash chip admits maximum 40 bad 3130 eraseblocks, and it is split on two MTD partitions of the same 3131 size, UBI will reserve 40 eraseblocks when attaching a 3132 partition. 3133 3134 default: 20 3135 3136 CONFIG_MTD_UBI_FASTMAP 3137 Fastmap is a mechanism which allows attaching an UBI device 3138 in nearly constant time. Instead of scanning the whole MTD device it 3139 only has to locate a checkpoint (called fastmap) on the device. 3140 The on-flash fastmap contains all information needed to attach 3141 the device. Using fastmap makes only sense on large devices where 3142 attaching by scanning takes long. UBI will not automatically install 3143 a fastmap on old images, but you can set the UBI parameter 3144 CONFIG_MTD_UBI_FASTMAP_AUTOCONVERT to 1 if you want so. Please note 3145 that fastmap-enabled images are still usable with UBI implementations 3146 without fastmap support. On typical flash devices the whole fastmap 3147 fits into one PEB. UBI will reserve PEBs to hold two fastmaps. 3148 3149 CONFIG_MTD_UBI_FASTMAP_AUTOCONVERT 3150 Set this parameter to enable fastmap automatically on images 3151 without a fastmap. 3152 default: 0 3153 3154 CONFIG_MTD_UBI_FM_DEBUG 3155 Enable UBI fastmap debug 3156 default: 0 3157 3158- UBIFS support 3159 CONFIG_CMD_UBIFS 3160 3161 Adds commands for interacting with UBI volumes formatted as 3162 UBIFS. UBIFS is read-only in u-boot. 3163 3164 Requires UBI support as well as CONFIG_LZO 3165 3166 CONFIG_UBIFS_SILENCE_MSG 3167 3168 Make the verbose messages from UBIFS stop printing. This leaves 3169 warnings and errors enabled. 3170 3171- SPL framework 3172 CONFIG_SPL 3173 Enable building of SPL globally. 3174 3175 CONFIG_SPL_LDSCRIPT 3176 LDSCRIPT for linking the SPL binary. 3177 3178 CONFIG_SPL_MAX_FOOTPRINT 3179 Maximum size in memory allocated to the SPL, BSS included. 3180 When defined, the linker checks that the actual memory 3181 used by SPL from _start to __bss_end does not exceed it. 3182 CONFIG_SPL_MAX_FOOTPRINT and CONFIG_SPL_BSS_MAX_SIZE 3183 must not be both defined at the same time. 3184 3185 CONFIG_SPL_MAX_SIZE 3186 Maximum size of the SPL image (text, data, rodata, and 3187 linker lists sections), BSS excluded. 3188 When defined, the linker checks that the actual size does 3189 not exceed it. 3190 3191 CONFIG_SPL_TEXT_BASE 3192 TEXT_BASE for linking the SPL binary. 3193 3194 CONFIG_SPL_RELOC_TEXT_BASE 3195 Address to relocate to. If unspecified, this is equal to 3196 CONFIG_SPL_TEXT_BASE (i.e. no relocation is done). 3197 3198 CONFIG_SPL_BSS_START_ADDR 3199 Link address for the BSS within the SPL binary. 3200 3201 CONFIG_SPL_BSS_MAX_SIZE 3202 Maximum size in memory allocated to the SPL BSS. 3203 When defined, the linker checks that the actual memory used 3204 by SPL from __bss_start to __bss_end does not exceed it. 3205 CONFIG_SPL_MAX_FOOTPRINT and CONFIG_SPL_BSS_MAX_SIZE 3206 must not be both defined at the same time. 3207 3208 CONFIG_SPL_STACK 3209 Adress of the start of the stack SPL will use 3210 3211 CONFIG_SPL_PANIC_ON_RAW_IMAGE 3212 When defined, SPL will panic() if the image it has 3213 loaded does not have a signature. 3214 Defining this is useful when code which loads images 3215 in SPL cannot guarantee that absolutely all read errors 3216 will be caught. 3217 An example is the LPC32XX MLC NAND driver, which will 3218 consider that a completely unreadable NAND block is bad, 3219 and thus should be skipped silently. 3220 3221 CONFIG_SPL_RELOC_STACK 3222 Adress of the start of the stack SPL will use after 3223 relocation. If unspecified, this is equal to 3224 CONFIG_SPL_STACK. 3225 3226 CONFIG_SYS_SPL_MALLOC_START 3227 Starting address of the malloc pool used in SPL. 3228 When this option is set the full malloc is used in SPL and 3229 it is set up by spl_init() and before that, the simple malloc() 3230 can be used if CONFIG_SYS_MALLOC_F is defined. 3231 3232 CONFIG_SYS_SPL_MALLOC_SIZE 3233 The size of the malloc pool used in SPL. 3234 3235 CONFIG_SPL_FRAMEWORK 3236 Enable the SPL framework under common/. This framework 3237 supports MMC, NAND and YMODEM loading of U-Boot and NAND 3238 NAND loading of the Linux Kernel. 3239 3240 CONFIG_SPL_OS_BOOT 3241 Enable booting directly to an OS from SPL. 3242 See also: doc/README.falcon 3243 3244 CONFIG_SPL_DISPLAY_PRINT 3245 For ARM, enable an optional function to print more information 3246 about the running system. 3247 3248 CONFIG_SPL_INIT_MINIMAL 3249 Arch init code should be built for a very small image 3250 3251 CONFIG_SYS_MMCSD_RAW_MODE_U_BOOT_PARTITION 3252 Partition on the MMC to load U-Boot from when the MMC is being 3253 used in raw mode 3254 3255 CONFIG_SYS_MMCSD_RAW_MODE_KERNEL_SECTOR 3256 Sector to load kernel uImage from when MMC is being 3257 used in raw mode (for Falcon mode) 3258 3259 CONFIG_SYS_MMCSD_RAW_MODE_ARGS_SECTOR, 3260 CONFIG_SYS_MMCSD_RAW_MODE_ARGS_SECTORS 3261 Sector and number of sectors to load kernel argument 3262 parameters from when MMC is being used in raw mode 3263 (for falcon mode) 3264 3265 CONFIG_SYS_MMCSD_FS_BOOT_PARTITION 3266 Partition on the MMC to load U-Boot from when the MMC is being 3267 used in fs mode 3268 3269 CONFIG_SPL_FS_LOAD_PAYLOAD_NAME 3270 Filename to read to load U-Boot when reading from filesystem 3271 3272 CONFIG_SPL_FS_LOAD_KERNEL_NAME 3273 Filename to read to load kernel uImage when reading 3274 from filesystem (for Falcon mode) 3275 3276 CONFIG_SPL_FS_LOAD_ARGS_NAME 3277 Filename to read to load kernel argument parameters 3278 when reading from filesystem (for Falcon mode) 3279 3280 CONFIG_SPL_MPC83XX_WAIT_FOR_NAND 3281 Set this for NAND SPL on PPC mpc83xx targets, so that 3282 start.S waits for the rest of the SPL to load before 3283 continuing (the hardware starts execution after just 3284 loading the first page rather than the full 4K). 3285 3286 CONFIG_SPL_SKIP_RELOCATE 3287 Avoid SPL relocation 3288 3289 CONFIG_SPL_NAND_BASE 3290 Include nand_base.c in the SPL. Requires 3291 CONFIG_SPL_NAND_DRIVERS. 3292 3293 CONFIG_SPL_NAND_DRIVERS 3294 SPL uses normal NAND drivers, not minimal drivers. 3295 3296 CONFIG_SPL_NAND_ECC 3297 Include standard software ECC in the SPL 3298 3299 CONFIG_SPL_NAND_SIMPLE 3300 Support for NAND boot using simple NAND drivers that 3301 expose the cmd_ctrl() interface. 3302 3303 CONFIG_SPL_UBI 3304 Support for a lightweight UBI (fastmap) scanner and 3305 loader 3306 3307 CONFIG_SPL_NAND_RAW_ONLY 3308 Support to boot only raw u-boot.bin images. Use this only 3309 if you need to save space. 3310 3311 CONFIG_SPL_COMMON_INIT_DDR 3312 Set for common ddr init with serial presence detect in 3313 SPL binary. 3314 3315 CONFIG_SYS_NAND_5_ADDR_CYCLE, CONFIG_SYS_NAND_PAGE_COUNT, 3316 CONFIG_SYS_NAND_PAGE_SIZE, CONFIG_SYS_NAND_OOBSIZE, 3317 CONFIG_SYS_NAND_BLOCK_SIZE, CONFIG_SYS_NAND_BAD_BLOCK_POS, 3318 CONFIG_SYS_NAND_ECCPOS, CONFIG_SYS_NAND_ECCSIZE, 3319 CONFIG_SYS_NAND_ECCBYTES 3320 Defines the size and behavior of the NAND that SPL uses 3321 to read U-Boot 3322 3323 CONFIG_SPL_NAND_BOOT 3324 Add support NAND boot 3325 3326 CONFIG_SYS_NAND_U_BOOT_OFFS 3327 Location in NAND to read U-Boot from 3328 3329 CONFIG_SYS_NAND_U_BOOT_DST 3330 Location in memory to load U-Boot to 3331 3332 CONFIG_SYS_NAND_U_BOOT_SIZE 3333 Size of image to load 3334 3335 CONFIG_SYS_NAND_U_BOOT_START 3336 Entry point in loaded image to jump to 3337 3338 CONFIG_SYS_NAND_HW_ECC_OOBFIRST 3339 Define this if you need to first read the OOB and then the 3340 data. This is used, for example, on davinci platforms. 3341 3342 CONFIG_SPL_OMAP3_ID_NAND 3343 Support for an OMAP3-specific set of functions to return the 3344 ID and MFR of the first attached NAND chip, if present. 3345 3346 CONFIG_SPL_RAM_DEVICE 3347 Support for running image already present in ram, in SPL binary 3348 3349 CONFIG_SPL_PAD_TO 3350 Image offset to which the SPL should be padded before appending 3351 the SPL payload. By default, this is defined as 3352 CONFIG_SPL_MAX_SIZE, or 0 if CONFIG_SPL_MAX_SIZE is undefined. 3353 CONFIG_SPL_PAD_TO must be either 0, meaning to append the SPL 3354 payload without any padding, or >= CONFIG_SPL_MAX_SIZE. 3355 3356 CONFIG_SPL_TARGET 3357 Final target image containing SPL and payload. Some SPLs 3358 use an arch-specific makefile fragment instead, for 3359 example if more than one image needs to be produced. 3360 3361 CONFIG_FIT_SPL_PRINT 3362 Printing information about a FIT image adds quite a bit of 3363 code to SPL. So this is normally disabled in SPL. Use this 3364 option to re-enable it. This will affect the output of the 3365 bootm command when booting a FIT image. 3366 3367- TPL framework 3368 CONFIG_TPL 3369 Enable building of TPL globally. 3370 3371 CONFIG_TPL_PAD_TO 3372 Image offset to which the TPL should be padded before appending 3373 the TPL payload. By default, this is defined as 3374 CONFIG_SPL_MAX_SIZE, or 0 if CONFIG_SPL_MAX_SIZE is undefined. 3375 CONFIG_SPL_PAD_TO must be either 0, meaning to append the SPL 3376 payload without any padding, or >= CONFIG_SPL_MAX_SIZE. 3377 3378- Interrupt support (PPC): 3379 3380 There are common interrupt_init() and timer_interrupt() 3381 for all PPC archs. interrupt_init() calls interrupt_init_cpu() 3382 for CPU specific initialization. interrupt_init_cpu() 3383 should set decrementer_count to appropriate value. If 3384 CPU resets decrementer automatically after interrupt 3385 (ppc4xx) it should set decrementer_count to zero. 3386 timer_interrupt() calls timer_interrupt_cpu() for CPU 3387 specific handling. If board has watchdog / status_led 3388 / other_activity_monitor it works automatically from 3389 general timer_interrupt(). 3390 3391 3392Board initialization settings: 3393------------------------------ 3394 3395During Initialization u-boot calls a number of board specific functions 3396to allow the preparation of board specific prerequisites, e.g. pin setup 3397before drivers are initialized. To enable these callbacks the 3398following configuration macros have to be defined. Currently this is 3399architecture specific, so please check arch/your_architecture/lib/board.c 3400typically in board_init_f() and board_init_r(). 3401 3402- CONFIG_BOARD_EARLY_INIT_F: Call board_early_init_f() 3403- CONFIG_BOARD_EARLY_INIT_R: Call board_early_init_r() 3404- CONFIG_BOARD_LATE_INIT: Call board_late_init() 3405- CONFIG_BOARD_POSTCLK_INIT: Call board_postclk_init() 3406 3407Configuration Settings: 3408----------------------- 3409 3410- CONFIG_SYS_SUPPORT_64BIT_DATA: Defined automatically if compiled as 64-bit. 3411 Optionally it can be defined to support 64-bit memory commands. 3412 3413- CONFIG_SYS_LONGHELP: Defined when you want long help messages included; 3414 undefine this when you're short of memory. 3415 3416- CONFIG_SYS_HELP_CMD_WIDTH: Defined when you want to override the default 3417 width of the commands listed in the 'help' command output. 3418 3419- CONFIG_SYS_PROMPT: This is what U-Boot prints on the console to 3420 prompt for user input. 3421 3422- CONFIG_SYS_CBSIZE: Buffer size for input from the Console 3423 3424- CONFIG_SYS_PBSIZE: Buffer size for Console output 3425 3426- CONFIG_SYS_MAXARGS: max. Number of arguments accepted for monitor commands 3427 3428- CONFIG_SYS_BARGSIZE: Buffer size for Boot Arguments which are passed to 3429 the application (usually a Linux kernel) when it is 3430 booted 3431 3432- CONFIG_SYS_BAUDRATE_TABLE: 3433 List of legal baudrate settings for this board. 3434 3435- CONFIG_SYS_MEMTEST_START, CONFIG_SYS_MEMTEST_END: 3436 Begin and End addresses of the area used by the 3437 simple memory test. 3438 3439- CONFIG_SYS_ALT_MEMTEST: 3440 Enable an alternate, more extensive memory test. 3441 3442- CONFIG_SYS_MEMTEST_SCRATCH: 3443 Scratch address used by the alternate memory test 3444 You only need to set this if address zero isn't writeable 3445 3446- CONFIG_SYS_MEM_RESERVE_SECURE 3447 Only implemented for ARMv8 for now. 3448 If defined, the size of CONFIG_SYS_MEM_RESERVE_SECURE memory 3449 is substracted from total RAM and won't be reported to OS. 3450 This memory can be used as secure memory. A variable 3451 gd->arch.secure_ram is used to track the location. In systems 3452 the RAM base is not zero, or RAM is divided into banks, 3453 this variable needs to be recalcuated to get the address. 3454 3455- CONFIG_SYS_MEM_TOP_HIDE: 3456 If CONFIG_SYS_MEM_TOP_HIDE is defined in the board config header, 3457 this specified memory area will get subtracted from the top 3458 (end) of RAM and won't get "touched" at all by U-Boot. By 3459 fixing up gd->ram_size the Linux kernel should gets passed 3460 the now "corrected" memory size and won't touch it either. 3461 This should work for arch/ppc and arch/powerpc. Only Linux 3462 board ports in arch/powerpc with bootwrapper support that 3463 recalculate the memory size from the SDRAM controller setup 3464 will have to get fixed in Linux additionally. 3465 3466 This option can be used as a workaround for the 440EPx/GRx 3467 CHIP 11 errata where the last 256 bytes in SDRAM shouldn't 3468 be touched. 3469 3470 WARNING: Please make sure that this value is a multiple of 3471 the Linux page size (normally 4k). If this is not the case, 3472 then the end address of the Linux memory will be located at a 3473 non page size aligned address and this could cause major 3474 problems. 3475 3476- CONFIG_SYS_LOADS_BAUD_CHANGE: 3477 Enable temporary baudrate change while serial download 3478 3479- CONFIG_SYS_SDRAM_BASE: 3480 Physical start address of SDRAM. _Must_ be 0 here. 3481 3482- CONFIG_SYS_FLASH_BASE: 3483 Physical start address of Flash memory. 3484 3485- CONFIG_SYS_MONITOR_BASE: 3486 Physical start address of boot monitor code (set by 3487 make config files to be same as the text base address 3488 (CONFIG_SYS_TEXT_BASE) used when linking) - same as 3489 CONFIG_SYS_FLASH_BASE when booting from flash. 3490 3491- CONFIG_SYS_MONITOR_LEN: 3492 Size of memory reserved for monitor code, used to 3493 determine _at_compile_time_ (!) if the environment is 3494 embedded within the U-Boot image, or in a separate 3495 flash sector. 3496 3497- CONFIG_SYS_MALLOC_LEN: 3498 Size of DRAM reserved for malloc() use. 3499 3500- CONFIG_SYS_MALLOC_F_LEN 3501 Size of the malloc() pool for use before relocation. If 3502 this is defined, then a very simple malloc() implementation 3503 will become available before relocation. The address is just 3504 below the global data, and the stack is moved down to make 3505 space. 3506 3507 This feature allocates regions with increasing addresses 3508 within the region. calloc() is supported, but realloc() 3509 is not available. free() is supported but does nothing. 3510 The memory will be freed (or in fact just forgotten) when 3511 U-Boot relocates itself. 3512 3513- CONFIG_SYS_MALLOC_SIMPLE 3514 Provides a simple and small malloc() and calloc() for those 3515 boards which do not use the full malloc in SPL (which is 3516 enabled with CONFIG_SYS_SPL_MALLOC_START). 3517 3518- CONFIG_SYS_NONCACHED_MEMORY: 3519 Size of non-cached memory area. This area of memory will be 3520 typically located right below the malloc() area and mapped 3521 uncached in the MMU. This is useful for drivers that would 3522 otherwise require a lot of explicit cache maintenance. For 3523 some drivers it's also impossible to properly maintain the 3524 cache. For example if the regions that need to be flushed 3525 are not a multiple of the cache-line size, *and* padding 3526 cannot be allocated between the regions to align them (i.e. 3527 if the HW requires a contiguous array of regions, and the 3528 size of each region is not cache-aligned), then a flush of 3529 one region may result in overwriting data that hardware has 3530 written to another region in the same cache-line. This can 3531 happen for example in network drivers where descriptors for 3532 buffers are typically smaller than the CPU cache-line (e.g. 3533 16 bytes vs. 32 or 64 bytes). 3534 3535 Non-cached memory is only supported on 32-bit ARM at present. 3536 3537- CONFIG_SYS_BOOTM_LEN: 3538 Normally compressed uImages are limited to an 3539 uncompressed size of 8 MBytes. If this is not enough, 3540 you can define CONFIG_SYS_BOOTM_LEN in your board config file 3541 to adjust this setting to your needs. 3542 3543- CONFIG_SYS_BOOTMAPSZ: 3544 Maximum size of memory mapped by the startup code of 3545 the Linux kernel; all data that must be processed by 3546 the Linux kernel (bd_info, boot arguments, FDT blob if 3547 used) must be put below this limit, unless "bootm_low" 3548 environment variable is defined and non-zero. In such case 3549 all data for the Linux kernel must be between "bootm_low" 3550 and "bootm_low" + CONFIG_SYS_BOOTMAPSZ. The environment 3551 variable "bootm_mapsize" will override the value of 3552 CONFIG_SYS_BOOTMAPSZ. If CONFIG_SYS_BOOTMAPSZ is undefined, 3553 then the value in "bootm_size" will be used instead. 3554 3555- CONFIG_SYS_BOOT_RAMDISK_HIGH: 3556 Enable initrd_high functionality. If defined then the 3557 initrd_high feature is enabled and the bootm ramdisk subcommand 3558 is enabled. 3559 3560- CONFIG_SYS_BOOT_GET_CMDLINE: 3561 Enables allocating and saving kernel cmdline in space between 3562 "bootm_low" and "bootm_low" + BOOTMAPSZ. 3563 3564- CONFIG_SYS_BOOT_GET_KBD: 3565 Enables allocating and saving a kernel copy of the bd_info in 3566 space between "bootm_low" and "bootm_low" + BOOTMAPSZ. 3567 3568- CONFIG_SYS_MAX_FLASH_BANKS: 3569 Max number of Flash memory banks 3570 3571- CONFIG_SYS_MAX_FLASH_SECT: 3572 Max number of sectors on a Flash chip 3573 3574- CONFIG_SYS_FLASH_ERASE_TOUT: 3575 Timeout for Flash erase operations (in ms) 3576 3577- CONFIG_SYS_FLASH_WRITE_TOUT: 3578 Timeout for Flash write operations (in ms) 3579 3580- CONFIG_SYS_FLASH_LOCK_TOUT 3581 Timeout for Flash set sector lock bit operation (in ms) 3582 3583- CONFIG_SYS_FLASH_UNLOCK_TOUT 3584 Timeout for Flash clear lock bits operation (in ms) 3585 3586- CONFIG_SYS_FLASH_PROTECTION 3587 If defined, hardware flash sectors protection is used 3588 instead of U-Boot software protection. 3589 3590- CONFIG_SYS_DIRECT_FLASH_TFTP: 3591 3592 Enable TFTP transfers directly to flash memory; 3593 without this option such a download has to be 3594 performed in two steps: (1) download to RAM, and (2) 3595 copy from RAM to flash. 3596 3597 The two-step approach is usually more reliable, since 3598 you can check if the download worked before you erase 3599 the flash, but in some situations (when system RAM is 3600 too limited to allow for a temporary copy of the 3601 downloaded image) this option may be very useful. 3602 3603- CONFIG_SYS_FLASH_CFI: 3604 Define if the flash driver uses extra elements in the 3605 common flash structure for storing flash geometry. 3606 3607- CONFIG_FLASH_CFI_DRIVER 3608 This option also enables the building of the cfi_flash driver 3609 in the drivers directory 3610 3611- CONFIG_FLASH_CFI_MTD 3612 This option enables the building of the cfi_mtd driver 3613 in the drivers directory. The driver exports CFI flash 3614 to the MTD layer. 3615 3616- CONFIG_SYS_FLASH_USE_BUFFER_WRITE 3617 Use buffered writes to flash. 3618 3619- CONFIG_FLASH_SPANSION_S29WS_N 3620 s29ws-n MirrorBit flash has non-standard addresses for buffered 3621 write commands. 3622 3623- CONFIG_SYS_FLASH_QUIET_TEST 3624 If this option is defined, the common CFI flash doesn't 3625 print it's warning upon not recognized FLASH banks. This 3626 is useful, if some of the configured banks are only 3627 optionally available. 3628 3629- CONFIG_FLASH_SHOW_PROGRESS 3630 If defined (must be an integer), print out countdown 3631 digits and dots. Recommended value: 45 (9..1) for 80 3632 column displays, 15 (3..1) for 40 column displays. 3633 3634- CONFIG_FLASH_VERIFY 3635 If defined, the content of the flash (destination) is compared 3636 against the source after the write operation. An error message 3637 will be printed when the contents are not identical. 3638 Please note that this option is useless in nearly all cases, 3639 since such flash programming errors usually are detected earlier 3640 while unprotecting/erasing/programming. Please only enable 3641 this option if you really know what you are doing. 3642 3643- CONFIG_SYS_RX_ETH_BUFFER: 3644 Defines the number of Ethernet receive buffers. On some 3645 Ethernet controllers it is recommended to set this value 3646 to 8 or even higher (EEPRO100 or 405 EMAC), since all 3647 buffers can be full shortly after enabling the interface 3648 on high Ethernet traffic. 3649 Defaults to 4 if not defined. 3650 3651- CONFIG_ENV_MAX_ENTRIES 3652 3653 Maximum number of entries in the hash table that is used 3654 internally to store the environment settings. The default 3655 setting is supposed to be generous and should work in most 3656 cases. This setting can be used to tune behaviour; see 3657 lib/hashtable.c for details. 3658 3659- CONFIG_ENV_FLAGS_LIST_DEFAULT 3660- CONFIG_ENV_FLAGS_LIST_STATIC 3661 Enable validation of the values given to environment variables when 3662 calling env set. Variables can be restricted to only decimal, 3663 hexadecimal, or boolean. If CONFIG_CMD_NET is also defined, 3664 the variables can also be restricted to IP address or MAC address. 3665 3666 The format of the list is: 3667 type_attribute = [s|d|x|b|i|m] 3668 access_attribute = [a|r|o|c] 3669 attributes = type_attribute[access_attribute] 3670 entry = variable_name[:attributes] 3671 list = entry[,list] 3672 3673 The type attributes are: 3674 s - String (default) 3675 d - Decimal 3676 x - Hexadecimal 3677 b - Boolean ([1yYtT|0nNfF]) 3678 i - IP address 3679 m - MAC address 3680 3681 The access attributes are: 3682 a - Any (default) 3683 r - Read-only 3684 o - Write-once 3685 c - Change-default 3686 3687 - CONFIG_ENV_FLAGS_LIST_DEFAULT 3688 Define this to a list (string) to define the ".flags" 3689 environment variable in the default or embedded environment. 3690 3691 - CONFIG_ENV_FLAGS_LIST_STATIC 3692 Define this to a list (string) to define validation that 3693 should be done if an entry is not found in the ".flags" 3694 environment variable. To override a setting in the static 3695 list, simply add an entry for the same variable name to the 3696 ".flags" variable. 3697 3698 If CONFIG_REGEX is defined, the variable_name above is evaluated as a 3699 regular expression. This allows multiple variables to define the same 3700 flags without explicitly listing them for each variable. 3701 3702- CONFIG_ENV_ACCESS_IGNORE_FORCE 3703 If defined, don't allow the -f switch to env set override variable 3704 access flags. 3705 3706- CONFIG_OMAP_PLATFORM_RESET_TIME_MAX_USEC (OMAP only) 3707 This is set by OMAP boards for the max time that reset should 3708 be asserted. See doc/README.omap-reset-time for details on how 3709 the value can be calculated on a given board. 3710 3711- CONFIG_USE_STDINT 3712 If stdint.h is available with your toolchain you can define this 3713 option to enable it. You can provide option 'USE_STDINT=1' when 3714 building U-Boot to enable this. 3715 3716The following definitions that deal with the placement and management 3717of environment data (variable area); in general, we support the 3718following configurations: 3719 3720- CONFIG_BUILD_ENVCRC: 3721 3722 Builds up envcrc with the target environment so that external utils 3723 may easily extract it and embed it in final U-Boot images. 3724 3725- CONFIG_ENV_IS_IN_FLASH: 3726 3727 Define this if the environment is in flash memory. 3728 3729 a) The environment occupies one whole flash sector, which is 3730 "embedded" in the text segment with the U-Boot code. This 3731 happens usually with "bottom boot sector" or "top boot 3732 sector" type flash chips, which have several smaller 3733 sectors at the start or the end. For instance, such a 3734 layout can have sector sizes of 8, 2x4, 16, Nx32 kB. In 3735 such a case you would place the environment in one of the 3736 4 kB sectors - with U-Boot code before and after it. With 3737 "top boot sector" type flash chips, you would put the 3738 environment in one of the last sectors, leaving a gap 3739 between U-Boot and the environment. 3740 3741 - CONFIG_ENV_OFFSET: 3742 3743 Offset of environment data (variable area) to the 3744 beginning of flash memory; for instance, with bottom boot 3745 type flash chips the second sector can be used: the offset 3746 for this sector is given here. 3747 3748 CONFIG_ENV_OFFSET is used relative to CONFIG_SYS_FLASH_BASE. 3749 3750 - CONFIG_ENV_ADDR: 3751 3752 This is just another way to specify the start address of 3753 the flash sector containing the environment (instead of 3754 CONFIG_ENV_OFFSET). 3755 3756 - CONFIG_ENV_SECT_SIZE: 3757 3758 Size of the sector containing the environment. 3759 3760 3761 b) Sometimes flash chips have few, equal sized, BIG sectors. 3762 In such a case you don't want to spend a whole sector for 3763 the environment. 3764 3765 - CONFIG_ENV_SIZE: 3766 3767 If you use this in combination with CONFIG_ENV_IS_IN_FLASH 3768 and CONFIG_ENV_SECT_SIZE, you can specify to use only a part 3769 of this flash sector for the environment. This saves 3770 memory for the RAM copy of the environment. 3771 3772 It may also save flash memory if you decide to use this 3773 when your environment is "embedded" within U-Boot code, 3774 since then the remainder of the flash sector could be used 3775 for U-Boot code. It should be pointed out that this is 3776 STRONGLY DISCOURAGED from a robustness point of view: 3777 updating the environment in flash makes it always 3778 necessary to erase the WHOLE sector. If something goes 3779 wrong before the contents has been restored from a copy in 3780 RAM, your target system will be dead. 3781 3782 - CONFIG_ENV_ADDR_REDUND 3783 CONFIG_ENV_SIZE_REDUND 3784 3785 These settings describe a second storage area used to hold 3786 a redundant copy of the environment data, so that there is 3787 a valid backup copy in case there is a power failure during 3788 a "saveenv" operation. 3789 3790BE CAREFUL! Any changes to the flash layout, and some changes to the 3791source code will make it necessary to adapt <board>/u-boot.lds* 3792accordingly! 3793 3794 3795- CONFIG_ENV_IS_IN_NVRAM: 3796 3797 Define this if you have some non-volatile memory device 3798 (NVRAM, battery buffered SRAM) which you want to use for the 3799 environment. 3800 3801 - CONFIG_ENV_ADDR: 3802 - CONFIG_ENV_SIZE: 3803 3804 These two #defines are used to determine the memory area you 3805 want to use for environment. It is assumed that this memory 3806 can just be read and written to, without any special 3807 provision. 3808 3809BE CAREFUL! The first access to the environment happens quite early 3810in U-Boot initialization (when we try to get the setting of for the 3811console baudrate). You *MUST* have mapped your NVRAM area then, or 3812U-Boot will hang. 3813 3814Please note that even with NVRAM we still use a copy of the 3815environment in RAM: we could work on NVRAM directly, but we want to 3816keep settings there always unmodified except somebody uses "saveenv" 3817to save the current settings. 3818 3819 3820- CONFIG_ENV_IS_IN_EEPROM: 3821 3822 Use this if you have an EEPROM or similar serial access 3823 device and a driver for it. 3824 3825 - CONFIG_ENV_OFFSET: 3826 - CONFIG_ENV_SIZE: 3827 3828 These two #defines specify the offset and size of the 3829 environment area within the total memory of your EEPROM. 3830 3831 - CONFIG_SYS_I2C_EEPROM_ADDR: 3832 If defined, specified the chip address of the EEPROM device. 3833 The default address is zero. 3834 3835 - CONFIG_SYS_I2C_EEPROM_BUS: 3836 If defined, specified the i2c bus of the EEPROM device. 3837 3838 - CONFIG_SYS_EEPROM_PAGE_WRITE_BITS: 3839 If defined, the number of bits used to address bytes in a 3840 single page in the EEPROM device. A 64 byte page, for example 3841 would require six bits. 3842 3843 - CONFIG_SYS_EEPROM_PAGE_WRITE_DELAY_MS: 3844 If defined, the number of milliseconds to delay between 3845 page writes. The default is zero milliseconds. 3846 3847 - CONFIG_SYS_I2C_EEPROM_ADDR_LEN: 3848 The length in bytes of the EEPROM memory array address. Note 3849 that this is NOT the chip address length! 3850 3851 - CONFIG_SYS_I2C_EEPROM_ADDR_OVERFLOW: 3852 EEPROM chips that implement "address overflow" are ones 3853 like Catalyst 24WC04/08/16 which has 9/10/11 bits of 3854 address and the extra bits end up in the "chip address" bit 3855 slots. This makes a 24WC08 (1Kbyte) chip look like four 256 3856 byte chips. 3857 3858 Note that we consider the length of the address field to 3859 still be one byte because the extra address bits are hidden 3860 in the chip address. 3861 3862 - CONFIG_SYS_EEPROM_SIZE: 3863 The size in bytes of the EEPROM device. 3864 3865 - CONFIG_ENV_EEPROM_IS_ON_I2C 3866 define this, if you have I2C and SPI activated, and your 3867 EEPROM, which holds the environment, is on the I2C bus. 3868 3869 - CONFIG_I2C_ENV_EEPROM_BUS 3870 if you have an Environment on an EEPROM reached over 3871 I2C muxes, you can define here, how to reach this 3872 EEPROM. For example: 3873 3874 #define CONFIG_I2C_ENV_EEPROM_BUS 1 3875 3876 EEPROM which holds the environment, is reached over 3877 a pca9547 i2c mux with address 0x70, channel 3. 3878 3879- CONFIG_ENV_IS_IN_DATAFLASH: 3880 3881 Define this if you have a DataFlash memory device which you 3882 want to use for the environment. 3883 3884 - CONFIG_ENV_OFFSET: 3885 - CONFIG_ENV_ADDR: 3886 - CONFIG_ENV_SIZE: 3887 3888 These three #defines specify the offset and size of the 3889 environment area within the total memory of your DataFlash placed 3890 at the specified address. 3891 3892- CONFIG_ENV_IS_IN_SPI_FLASH: 3893 3894 Define this if you have a SPI Flash memory device which you 3895 want to use for the environment. 3896 3897 - CONFIG_ENV_OFFSET: 3898 - CONFIG_ENV_SIZE: 3899 3900 These two #defines specify the offset and size of the 3901 environment area within the SPI Flash. CONFIG_ENV_OFFSET must be 3902 aligned to an erase sector boundary. 3903 3904 - CONFIG_ENV_SECT_SIZE: 3905 3906 Define the SPI flash's sector size. 3907 3908 - CONFIG_ENV_OFFSET_REDUND (optional): 3909 3910 This setting describes a second storage area of CONFIG_ENV_SIZE 3911 size used to hold a redundant copy of the environment data, so 3912 that there is a valid backup copy in case there is a power failure 3913 during a "saveenv" operation. CONFIG_ENV_OFFSET_REDUND must be 3914 aligned to an erase sector boundary. 3915 3916 - CONFIG_ENV_SPI_BUS (optional): 3917 - CONFIG_ENV_SPI_CS (optional): 3918 3919 Define the SPI bus and chip select. If not defined they will be 0. 3920 3921 - CONFIG_ENV_SPI_MAX_HZ (optional): 3922 3923 Define the SPI max work clock. If not defined then use 1MHz. 3924 3925 - CONFIG_ENV_SPI_MODE (optional): 3926 3927 Define the SPI work mode. If not defined then use SPI_MODE_3. 3928 3929- CONFIG_ENV_IS_IN_REMOTE: 3930 3931 Define this if you have a remote memory space which you 3932 want to use for the local device's environment. 3933 3934 - CONFIG_ENV_ADDR: 3935 - CONFIG_ENV_SIZE: 3936 3937 These two #defines specify the address and size of the 3938 environment area within the remote memory space. The 3939 local device can get the environment from remote memory 3940 space by SRIO or PCIE links. 3941 3942BE CAREFUL! For some special cases, the local device can not use 3943"saveenv" command. For example, the local device will get the 3944environment stored in a remote NOR flash by SRIO or PCIE link, 3945but it can not erase, write this NOR flash by SRIO or PCIE interface. 3946 3947- CONFIG_ENV_IS_IN_NAND: 3948 3949 Define this if you have a NAND device which you want to use 3950 for the environment. 3951 3952 - CONFIG_ENV_OFFSET: 3953 - CONFIG_ENV_SIZE: 3954 3955 These two #defines specify the offset and size of the environment 3956 area within the first NAND device. CONFIG_ENV_OFFSET must be 3957 aligned to an erase block boundary. 3958 3959 - CONFIG_ENV_OFFSET_REDUND (optional): 3960 3961 This setting describes a second storage area of CONFIG_ENV_SIZE 3962 size used to hold a redundant copy of the environment data, so 3963 that there is a valid backup copy in case there is a power failure 3964 during a "saveenv" operation. CONFIG_ENV_OFFSET_REDUND must be 3965 aligned to an erase block boundary. 3966 3967 - CONFIG_ENV_RANGE (optional): 3968 3969 Specifies the length of the region in which the environment 3970 can be written. This should be a multiple of the NAND device's 3971 block size. Specifying a range with more erase blocks than 3972 are needed to hold CONFIG_ENV_SIZE allows bad blocks within 3973 the range to be avoided. 3974 3975 - CONFIG_ENV_OFFSET_OOB (optional): 3976 3977 Enables support for dynamically retrieving the offset of the 3978 environment from block zero's out-of-band data. The 3979 "nand env.oob" command can be used to record this offset. 3980 Currently, CONFIG_ENV_OFFSET_REDUND is not supported when 3981 using CONFIG_ENV_OFFSET_OOB. 3982 3983- CONFIG_NAND_ENV_DST 3984 3985 Defines address in RAM to which the nand_spl code should copy the 3986 environment. If redundant environment is used, it will be copied to 3987 CONFIG_NAND_ENV_DST + CONFIG_ENV_SIZE. 3988 3989- CONFIG_ENV_IS_IN_UBI: 3990 3991 Define this if you have an UBI volume that you want to use for the 3992 environment. This has the benefit of wear-leveling the environment 3993 accesses, which is important on NAND. 3994 3995 - CONFIG_ENV_UBI_PART: 3996 3997 Define this to a string that is the mtd partition containing the UBI. 3998 3999 - CONFIG_ENV_UBI_VOLUME: 4000 4001 Define this to the name of the volume that you want to store the 4002 environment in. 4003 4004 - CONFIG_ENV_UBI_VOLUME_REDUND: 4005 4006 Define this to the name of another volume to store a second copy of 4007 the environment in. This will enable redundant environments in UBI. 4008 It is assumed that both volumes are in the same MTD partition. 4009 4010 - CONFIG_UBI_SILENCE_MSG 4011 - CONFIG_UBIFS_SILENCE_MSG 4012 4013 You will probably want to define these to avoid a really noisy system 4014 when storing the env in UBI. 4015 4016- CONFIG_ENV_IS_IN_FAT: 4017 Define this if you want to use the FAT file system for the environment. 4018 4019 - FAT_ENV_INTERFACE: 4020 4021 Define this to a string that is the name of the block device. 4022 4023 - FAT_ENV_DEVICE_AND_PART: 4024 4025 Define this to a string to specify the partition of the device. It can 4026 be as following: 4027 4028 "D:P", "D:0", "D", "D:" or "D:auto" (D, P are integers. And P >= 1) 4029 - "D:P": device D partition P. Error occurs if device D has no 4030 partition table. 4031 - "D:0": device D. 4032 - "D" or "D:": device D partition 1 if device D has partition 4033 table, or the whole device D if has no partition 4034 table. 4035 - "D:auto": first partition in device D with bootable flag set. 4036 If none, first valid partition in device D. If no 4037 partition table then means device D. 4038 4039 - FAT_ENV_FILE: 4040 4041 It's a string of the FAT file name. This file use to store the 4042 environment. 4043 4044 - CONFIG_FAT_WRITE: 4045 This should be defined. Otherwise it cannot save the environment file. 4046 4047- CONFIG_ENV_IS_IN_MMC: 4048 4049 Define this if you have an MMC device which you want to use for the 4050 environment. 4051 4052 - CONFIG_SYS_MMC_ENV_DEV: 4053 4054 Specifies which MMC device the environment is stored in. 4055 4056 - CONFIG_SYS_MMC_ENV_PART (optional): 4057 4058 Specifies which MMC partition the environment is stored in. If not 4059 set, defaults to partition 0, the user area. Common values might be 4060 1 (first MMC boot partition), 2 (second MMC boot partition). 4061 4062 - CONFIG_ENV_OFFSET: 4063 - CONFIG_ENV_SIZE: 4064 4065 These two #defines specify the offset and size of the environment 4066 area within the specified MMC device. 4067 4068 If offset is positive (the usual case), it is treated as relative to 4069 the start of the MMC partition. If offset is negative, it is treated 4070 as relative to the end of the MMC partition. This can be useful if 4071 your board may be fitted with different MMC devices, which have 4072 different sizes for the MMC partitions, and you always want the 4073 environment placed at the very end of the partition, to leave the 4074 maximum possible space before it, to store other data. 4075 4076 These two values are in units of bytes, but must be aligned to an 4077 MMC sector boundary. 4078 4079 - CONFIG_ENV_OFFSET_REDUND (optional): 4080 4081 Specifies a second storage area, of CONFIG_ENV_SIZE size, used to 4082 hold a redundant copy of the environment data. This provides a 4083 valid backup copy in case the other copy is corrupted, e.g. due 4084 to a power failure during a "saveenv" operation. 4085 4086 This value may also be positive or negative; this is handled in the 4087 same way as CONFIG_ENV_OFFSET. 4088 4089 This value is also in units of bytes, but must also be aligned to 4090 an MMC sector boundary. 4091 4092 - CONFIG_ENV_SIZE_REDUND (optional): 4093 4094 This value need not be set, even when CONFIG_ENV_OFFSET_REDUND is 4095 set. If this value is set, it must be set to the same value as 4096 CONFIG_ENV_SIZE. 4097 4098- CONFIG_SYS_SPI_INIT_OFFSET 4099 4100 Defines offset to the initial SPI buffer area in DPRAM. The 4101 area is used at an early stage (ROM part) if the environment 4102 is configured to reside in the SPI EEPROM: We need a 520 byte 4103 scratch DPRAM area. It is used between the two initialization 4104 calls (spi_init_f() and spi_init_r()). A value of 0xB00 seems 4105 to be a good choice since it makes it far enough from the 4106 start of the data area as well as from the stack pointer. 4107 4108Please note that the environment is read-only until the monitor 4109has been relocated to RAM and a RAM copy of the environment has been 4110created; also, when using EEPROM you will have to use getenv_f() 4111until then to read environment variables. 4112 4113The environment is protected by a CRC32 checksum. Before the monitor 4114is relocated into RAM, as a result of a bad CRC you will be working 4115with the compiled-in default environment - *silently*!!! [This is 4116necessary, because the first environment variable we need is the 4117"baudrate" setting for the console - if we have a bad CRC, we don't 4118have any device yet where we could complain.] 4119 4120Note: once the monitor has been relocated, then it will complain if 4121the default environment is used; a new CRC is computed as soon as you 4122use the "saveenv" command to store a valid environment. 4123 4124- CONFIG_SYS_FAULT_ECHO_LINK_DOWN: 4125 Echo the inverted Ethernet link state to the fault LED. 4126 4127 Note: If this option is active, then CONFIG_SYS_FAULT_MII_ADDR 4128 also needs to be defined. 4129 4130- CONFIG_SYS_FAULT_MII_ADDR: 4131 MII address of the PHY to check for the Ethernet link state. 4132 4133- CONFIG_NS16550_MIN_FUNCTIONS: 4134 Define this if you desire to only have use of the NS16550_init 4135 and NS16550_putc functions for the serial driver located at 4136 drivers/serial/ns16550.c. This option is useful for saving 4137 space for already greatly restricted images, including but not 4138 limited to NAND_SPL configurations. 4139 4140- CONFIG_DISPLAY_BOARDINFO 4141 Display information about the board that U-Boot is running on 4142 when U-Boot starts up. The board function checkboard() is called 4143 to do this. 4144 4145- CONFIG_DISPLAY_BOARDINFO_LATE 4146 Similar to the previous option, but display this information 4147 later, once stdio is running and output goes to the LCD, if 4148 present. 4149 4150- CONFIG_BOARD_SIZE_LIMIT: 4151 Maximum size of the U-Boot image. When defined, the 4152 build system checks that the actual size does not 4153 exceed it. 4154 4155Low Level (hardware related) configuration options: 4156--------------------------------------------------- 4157 4158- CONFIG_SYS_CACHELINE_SIZE: 4159 Cache Line Size of the CPU. 4160 4161- CONFIG_SYS_DEFAULT_IMMR: 4162 Default address of the IMMR after system reset. 4163 4164 Needed on some 8260 systems (MPC8260ADS, PQ2FADS-ZU, 4165 and RPXsuper) to be able to adjust the position of 4166 the IMMR register after a reset. 4167 4168- CONFIG_SYS_CCSRBAR_DEFAULT: 4169 Default (power-on reset) physical address of CCSR on Freescale 4170 PowerPC SOCs. 4171 4172- CONFIG_SYS_CCSRBAR: 4173 Virtual address of CCSR. On a 32-bit build, this is typically 4174 the same value as CONFIG_SYS_CCSRBAR_DEFAULT. 4175 4176 CONFIG_SYS_DEFAULT_IMMR must also be set to this value, 4177 for cross-platform code that uses that macro instead. 4178 4179- CONFIG_SYS_CCSRBAR_PHYS: 4180 Physical address of CCSR. CCSR can be relocated to a new 4181 physical address, if desired. In this case, this macro should 4182 be set to that address. Otherwise, it should be set to the 4183 same value as CONFIG_SYS_CCSRBAR_DEFAULT. For example, CCSR 4184 is typically relocated on 36-bit builds. It is recommended 4185 that this macro be defined via the _HIGH and _LOW macros: 4186 4187 #define CONFIG_SYS_CCSRBAR_PHYS ((CONFIG_SYS_CCSRBAR_PHYS_HIGH 4188 * 1ull) << 32 | CONFIG_SYS_CCSRBAR_PHYS_LOW) 4189 4190- CONFIG_SYS_CCSRBAR_PHYS_HIGH: 4191 Bits 33-36 of CONFIG_SYS_CCSRBAR_PHYS. This value is typically 4192 either 0 (32-bit build) or 0xF (36-bit build). This macro is 4193 used in assembly code, so it must not contain typecasts or 4194 integer size suffixes (e.g. "ULL"). 4195 4196- CONFIG_SYS_CCSRBAR_PHYS_LOW: 4197 Lower 32-bits of CONFIG_SYS_CCSRBAR_PHYS. This macro is 4198 used in assembly code, so it must not contain typecasts or 4199 integer size suffixes (e.g. "ULL"). 4200 4201- CONFIG_SYS_CCSR_DO_NOT_RELOCATE: 4202 If this macro is defined, then CONFIG_SYS_CCSRBAR_PHYS will be 4203 forced to a value that ensures that CCSR is not relocated. 4204 4205- Floppy Disk Support: 4206 CONFIG_SYS_FDC_DRIVE_NUMBER 4207 4208 the default drive number (default value 0) 4209 4210 CONFIG_SYS_ISA_IO_STRIDE 4211 4212 defines the spacing between FDC chipset registers 4213 (default value 1) 4214 4215 CONFIG_SYS_ISA_IO_OFFSET 4216 4217 defines the offset of register from address. It 4218 depends on which part of the data bus is connected to 4219 the FDC chipset. (default value 0) 4220 4221 If CONFIG_SYS_ISA_IO_STRIDE CONFIG_SYS_ISA_IO_OFFSET and 4222 CONFIG_SYS_FDC_DRIVE_NUMBER are undefined, they take their 4223 default value. 4224 4225 if CONFIG_SYS_FDC_HW_INIT is defined, then the function 4226 fdc_hw_init() is called at the beginning of the FDC 4227 setup. fdc_hw_init() must be provided by the board 4228 source code. It is used to make hardware-dependent 4229 initializations. 4230 4231- CONFIG_IDE_AHB: 4232 Most IDE controllers were designed to be connected with PCI 4233 interface. Only few of them were designed for AHB interface. 4234 When software is doing ATA command and data transfer to 4235 IDE devices through IDE-AHB controller, some additional 4236 registers accessing to these kind of IDE-AHB controller 4237 is required. 4238 4239- CONFIG_SYS_IMMR: Physical address of the Internal Memory. 4240 DO NOT CHANGE unless you know exactly what you're 4241 doing! (11-4) [MPC8xx/82xx systems only] 4242 4243- CONFIG_SYS_INIT_RAM_ADDR: 4244 4245 Start address of memory area that can be used for 4246 initial data and stack; please note that this must be 4247 writable memory that is working WITHOUT special 4248 initialization, i. e. you CANNOT use normal RAM which 4249 will become available only after programming the 4250 memory controller and running certain initialization 4251 sequences. 4252 4253 U-Boot uses the following memory types: 4254 - MPC8xx and MPC8260: IMMR (internal memory of the CPU) 4255 - MPC824X: data cache 4256 - PPC4xx: data cache 4257 4258- CONFIG_SYS_GBL_DATA_OFFSET: 4259 4260 Offset of the initial data structure in the memory 4261 area defined by CONFIG_SYS_INIT_RAM_ADDR. Usually 4262 CONFIG_SYS_GBL_DATA_OFFSET is chosen such that the initial 4263 data is located at the end of the available space 4264 (sometimes written as (CONFIG_SYS_INIT_RAM_SIZE - 4265 GENERATED_GBL_DATA_SIZE), and the initial stack is just 4266 below that area (growing from (CONFIG_SYS_INIT_RAM_ADDR + 4267 CONFIG_SYS_GBL_DATA_OFFSET) downward. 4268 4269 Note: 4270 On the MPC824X (or other systems that use the data 4271 cache for initial memory) the address chosen for 4272 CONFIG_SYS_INIT_RAM_ADDR is basically arbitrary - it must 4273 point to an otherwise UNUSED address space between 4274 the top of RAM and the start of the PCI space. 4275 4276- CONFIG_SYS_SIUMCR: SIU Module Configuration (11-6) 4277 4278- CONFIG_SYS_SYPCR: System Protection Control (11-9) 4279 4280- CONFIG_SYS_TBSCR: Time Base Status and Control (11-26) 4281 4282- CONFIG_SYS_PISCR: Periodic Interrupt Status and Control (11-31) 4283 4284- CONFIG_SYS_PLPRCR: PLL, Low-Power, and Reset Control Register (15-30) 4285 4286- CONFIG_SYS_SCCR: System Clock and reset Control Register (15-27) 4287 4288- CONFIG_SYS_OR_TIMING_SDRAM: 4289 SDRAM timing 4290 4291- CONFIG_SYS_MAMR_PTA: 4292 periodic timer for refresh 4293 4294- CONFIG_SYS_DER: Debug Event Register (37-47) 4295 4296- FLASH_BASE0_PRELIM, FLASH_BASE1_PRELIM, CONFIG_SYS_REMAP_OR_AM, 4297 CONFIG_SYS_PRELIM_OR_AM, CONFIG_SYS_OR_TIMING_FLASH, CONFIG_SYS_OR0_REMAP, 4298 CONFIG_SYS_OR0_PRELIM, CONFIG_SYS_BR0_PRELIM, CONFIG_SYS_OR1_REMAP, CONFIG_SYS_OR1_PRELIM, 4299 CONFIG_SYS_BR1_PRELIM: 4300 Memory Controller Definitions: BR0/1 and OR0/1 (FLASH) 4301 4302- SDRAM_BASE2_PRELIM, SDRAM_BASE3_PRELIM, SDRAM_MAX_SIZE, 4303 CONFIG_SYS_OR_TIMING_SDRAM, CONFIG_SYS_OR2_PRELIM, CONFIG_SYS_BR2_PRELIM, 4304 CONFIG_SYS_OR3_PRELIM, CONFIG_SYS_BR3_PRELIM: 4305 Memory Controller Definitions: BR2/3 and OR2/3 (SDRAM) 4306 4307- CONFIG_SYS_MAMR_PTA, CONFIG_SYS_MPTPR_2BK_4K, CONFIG_SYS_MPTPR_1BK_4K, CONFIG_SYS_MPTPR_2BK_8K, 4308 CONFIG_SYS_MPTPR_1BK_8K, CONFIG_SYS_MAMR_8COL, CONFIG_SYS_MAMR_9COL: 4309 Machine Mode Register and Memory Periodic Timer 4310 Prescaler definitions (SDRAM timing) 4311 4312- CONFIG_SYS_I2C_UCODE_PATCH, CONFIG_SYS_I2C_DPMEM_OFFSET [0x1FC0]: 4313 enable I2C microcode relocation patch (MPC8xx); 4314 define relocation offset in DPRAM [DSP2] 4315 4316- CONFIG_SYS_SMC_UCODE_PATCH, CONFIG_SYS_SMC_DPMEM_OFFSET [0x1FC0]: 4317 enable SMC microcode relocation patch (MPC8xx); 4318 define relocation offset in DPRAM [SMC1] 4319 4320- CONFIG_SYS_SPI_UCODE_PATCH, CONFIG_SYS_SPI_DPMEM_OFFSET [0x1FC0]: 4321 enable SPI microcode relocation patch (MPC8xx); 4322 define relocation offset in DPRAM [SCC4] 4323 4324- CONFIG_SYS_CPM_POST_WORD_ADDR: (MPC8xx, MPC8260 only) 4325 Offset of the bootmode word in DPRAM used by post 4326 (Power On Self Tests). This definition overrides 4327 #define'd default value in commproc.h resp. 4328 cpm_8260.h. 4329 4330- CONFIG_SYS_PCI_SLV_MEM_LOCAL, CONFIG_SYS_PCI_SLV_MEM_BUS, CONFIG_SYS_PICMR0_MASK_ATTRIB, 4331 CONFIG_SYS_PCI_MSTR0_LOCAL, CONFIG_SYS_PCIMSK0_MASK, CONFIG_SYS_PCI_MSTR1_LOCAL, 4332 CONFIG_SYS_PCIMSK1_MASK, CONFIG_SYS_PCI_MSTR_MEM_LOCAL, CONFIG_SYS_PCI_MSTR_MEM_BUS, 4333 CONFIG_SYS_CPU_PCI_MEM_START, CONFIG_SYS_PCI_MSTR_MEM_SIZE, CONFIG_SYS_POCMR0_MASK_ATTRIB, 4334 CONFIG_SYS_PCI_MSTR_MEMIO_LOCAL, CONFIG_SYS_PCI_MSTR_MEMIO_BUS, CPU_PCI_MEMIO_START, 4335 CONFIG_SYS_PCI_MSTR_MEMIO_SIZE, CONFIG_SYS_POCMR1_MASK_ATTRIB, CONFIG_SYS_PCI_MSTR_IO_LOCAL, 4336 CONFIG_SYS_PCI_MSTR_IO_BUS, CONFIG_SYS_CPU_PCI_IO_START, CONFIG_SYS_PCI_MSTR_IO_SIZE, 4337 CONFIG_SYS_POCMR2_MASK_ATTRIB: (MPC826x only) 4338 Overrides the default PCI memory map in arch/powerpc/cpu/mpc8260/pci.c if set. 4339 4340- CONFIG_PCI_DISABLE_PCIE: 4341 Disable PCI-Express on systems where it is supported but not 4342 required. 4343 4344- CONFIG_PCI_ENUM_ONLY 4345 Only scan through and get the devices on the buses. 4346 Don't do any setup work, presumably because someone or 4347 something has already done it, and we don't need to do it 4348 a second time. Useful for platforms that are pre-booted 4349 by coreboot or similar. 4350 4351- CONFIG_PCI_INDIRECT_BRIDGE: 4352 Enable support for indirect PCI bridges. 4353 4354- CONFIG_SYS_SRIO: 4355 Chip has SRIO or not 4356 4357- CONFIG_SRIO1: 4358 Board has SRIO 1 port available 4359 4360- CONFIG_SRIO2: 4361 Board has SRIO 2 port available 4362 4363- CONFIG_SRIO_PCIE_BOOT_MASTER 4364 Board can support master function for Boot from SRIO and PCIE 4365 4366- CONFIG_SYS_SRIOn_MEM_VIRT: 4367 Virtual Address of SRIO port 'n' memory region 4368 4369- CONFIG_SYS_SRIOn_MEM_PHYS: 4370 Physical Address of SRIO port 'n' memory region 4371 4372- CONFIG_SYS_SRIOn_MEM_SIZE: 4373 Size of SRIO port 'n' memory region 4374 4375- CONFIG_SYS_NAND_BUSWIDTH_16BIT 4376 Defined to tell the NAND controller that the NAND chip is using 4377 a 16 bit bus. 4378 Not all NAND drivers use this symbol. 4379 Example of drivers that use it: 4380 - drivers/mtd/nand/ndfc.c 4381 - drivers/mtd/nand/mxc_nand.c 4382 4383- CONFIG_SYS_NDFC_EBC0_CFG 4384 Sets the EBC0_CFG register for the NDFC. If not defined 4385 a default value will be used. 4386 4387- CONFIG_SPD_EEPROM 4388 Get DDR timing information from an I2C EEPROM. Common 4389 with pluggable memory modules such as SODIMMs 4390 4391 SPD_EEPROM_ADDRESS 4392 I2C address of the SPD EEPROM 4393 4394- CONFIG_SYS_SPD_BUS_NUM 4395 If SPD EEPROM is on an I2C bus other than the first 4396 one, specify here. Note that the value must resolve 4397 to something your driver can deal with. 4398 4399- CONFIG_SYS_DDR_RAW_TIMING 4400 Get DDR timing information from other than SPD. Common with 4401 soldered DDR chips onboard without SPD. DDR raw timing 4402 parameters are extracted from datasheet and hard-coded into 4403 header files or board specific files. 4404 4405- CONFIG_FSL_DDR_INTERACTIVE 4406 Enable interactive DDR debugging. See doc/README.fsl-ddr. 4407 4408- CONFIG_FSL_DDR_SYNC_REFRESH 4409 Enable sync of refresh for multiple controllers. 4410 4411- CONFIG_FSL_DDR_BIST 4412 Enable built-in memory test for Freescale DDR controllers. 4413 4414- CONFIG_SYS_83XX_DDR_USES_CS0 4415 Only for 83xx systems. If specified, then DDR should 4416 be configured using CS0 and CS1 instead of CS2 and CS3. 4417 4418- CONFIG_ETHER_ON_FEC[12] 4419 Define to enable FEC[12] on a 8xx series processor. 4420 4421- CONFIG_FEC[12]_PHY 4422 Define to the hardcoded PHY address which corresponds 4423 to the given FEC; i. e. 4424 #define CONFIG_FEC1_PHY 4 4425 means that the PHY with address 4 is connected to FEC1 4426 4427 When set to -1, means to probe for first available. 4428 4429- CONFIG_FEC[12]_PHY_NORXERR 4430 The PHY does not have a RXERR line (RMII only). 4431 (so program the FEC to ignore it). 4432 4433- CONFIG_RMII 4434 Enable RMII mode for all FECs. 4435 Note that this is a global option, we can't 4436 have one FEC in standard MII mode and another in RMII mode. 4437 4438- CONFIG_CRC32_VERIFY 4439 Add a verify option to the crc32 command. 4440 The syntax is: 4441 4442 => crc32 -v <address> <count> <crc32> 4443 4444 Where address/count indicate a memory area 4445 and crc32 is the correct crc32 which the 4446 area should have. 4447 4448- CONFIG_LOOPW 4449 Add the "loopw" memory command. This only takes effect if 4450 the memory commands are activated globally (CONFIG_CMD_MEM). 4451 4452- CONFIG_MX_CYCLIC 4453 Add the "mdc" and "mwc" memory commands. These are cyclic 4454 "md/mw" commands. 4455 Examples: 4456 4457 => mdc.b 10 4 500 4458 This command will print 4 bytes (10,11,12,13) each 500 ms. 4459 4460 => mwc.l 100 12345678 10 4461 This command will write 12345678 to address 100 all 10 ms. 4462 4463 This only takes effect if the memory commands are activated 4464 globally (CONFIG_CMD_MEM). 4465 4466- CONFIG_SKIP_LOWLEVEL_INIT 4467 [ARM, NDS32, MIPS only] If this variable is defined, then certain 4468 low level initializations (like setting up the memory 4469 controller) are omitted and/or U-Boot does not 4470 relocate itself into RAM. 4471 4472 Normally this variable MUST NOT be defined. The only 4473 exception is when U-Boot is loaded (to RAM) by some 4474 other boot loader or by a debugger which performs 4475 these initializations itself. 4476 4477- CONFIG_SKIP_LOWLEVEL_INIT_ONLY 4478 [ARM926EJ-S only] This allows just the call to lowlevel_init() 4479 to be skipped. The normal CP15 init (such as enabling the 4480 instruction cache) is still performed. 4481 4482- CONFIG_SPL_BUILD 4483 Modifies the behaviour of start.S when compiling a loader 4484 that is executed before the actual U-Boot. E.g. when 4485 compiling a NAND SPL. 4486 4487- CONFIG_TPL_BUILD 4488 Modifies the behaviour of start.S when compiling a loader 4489 that is executed after the SPL and before the actual U-Boot. 4490 It is loaded by the SPL. 4491 4492- CONFIG_SYS_MPC85XX_NO_RESETVEC 4493 Only for 85xx systems. If this variable is specified, the section 4494 .resetvec is not kept and the section .bootpg is placed in the 4495 previous 4k of the .text section. 4496 4497- CONFIG_ARCH_MAP_SYSMEM 4498 Generally U-Boot (and in particular the md command) uses 4499 effective address. It is therefore not necessary to regard 4500 U-Boot address as virtual addresses that need to be translated 4501 to physical addresses. However, sandbox requires this, since 4502 it maintains its own little RAM buffer which contains all 4503 addressable memory. This option causes some memory accesses 4504 to be mapped through map_sysmem() / unmap_sysmem(). 4505 4506- CONFIG_X86_RESET_VECTOR 4507 If defined, the x86 reset vector code is included. This is not 4508 needed when U-Boot is running from Coreboot. 4509 4510- CONFIG_SYS_MPUCLK 4511 Defines the MPU clock speed (in MHz). 4512 4513 NOTE : currently only supported on AM335x platforms. 4514 4515- CONFIG_SPL_AM33XX_ENABLE_RTC32K_OSC: 4516 Enables the RTC32K OSC on AM33xx based plattforms 4517 4518- CONFIG_SYS_NAND_NO_SUBPAGE_WRITE 4519 Option to disable subpage write in NAND driver 4520 driver that uses this: 4521 drivers/mtd/nand/davinci_nand.c 4522 4523Freescale QE/FMAN Firmware Support: 4524----------------------------------- 4525 4526The Freescale QUICCEngine (QE) and Frame Manager (FMAN) both support the 4527loading of "firmware", which is encoded in the QE firmware binary format. 4528This firmware often needs to be loaded during U-Boot booting, so macros 4529are used to identify the storage device (NOR flash, SPI, etc) and the address 4530within that device. 4531 4532- CONFIG_SYS_FMAN_FW_ADDR 4533 The address in the storage device where the FMAN microcode is located. The 4534 meaning of this address depends on which CONFIG_SYS_QE_FW_IN_xxx macro 4535 is also specified. 4536 4537- CONFIG_SYS_QE_FW_ADDR 4538 The address in the storage device where the QE microcode is located. The 4539 meaning of this address depends on which CONFIG_SYS_QE_FW_IN_xxx macro 4540 is also specified. 4541 4542- CONFIG_SYS_QE_FMAN_FW_LENGTH 4543 The maximum possible size of the firmware. The firmware binary format 4544 has a field that specifies the actual size of the firmware, but it 4545 might not be possible to read any part of the firmware unless some 4546 local storage is allocated to hold the entire firmware first. 4547 4548- CONFIG_SYS_QE_FMAN_FW_IN_NOR 4549 Specifies that QE/FMAN firmware is located in NOR flash, mapped as 4550 normal addressable memory via the LBC. CONFIG_SYS_FMAN_FW_ADDR is the 4551 virtual address in NOR flash. 4552 4553- CONFIG_SYS_QE_FMAN_FW_IN_NAND 4554 Specifies that QE/FMAN firmware is located in NAND flash. 4555 CONFIG_SYS_FMAN_FW_ADDR is the offset within NAND flash. 4556 4557- CONFIG_SYS_QE_FMAN_FW_IN_MMC 4558 Specifies that QE/FMAN firmware is located on the primary SD/MMC 4559 device. CONFIG_SYS_FMAN_FW_ADDR is the byte offset on that device. 4560 4561- CONFIG_SYS_QE_FMAN_FW_IN_REMOTE 4562 Specifies that QE/FMAN firmware is located in the remote (master) 4563 memory space. CONFIG_SYS_FMAN_FW_ADDR is a virtual address which 4564 can be mapped from slave TLB->slave LAW->slave SRIO or PCIE outbound 4565 window->master inbound window->master LAW->the ucode address in 4566 master's memory space. 4567 4568Freescale Layerscape Management Complex Firmware Support: 4569--------------------------------------------------------- 4570The Freescale Layerscape Management Complex (MC) supports the loading of 4571"firmware". 4572This firmware often needs to be loaded during U-Boot booting, so macros 4573are used to identify the storage device (NOR flash, SPI, etc) and the address 4574within that device. 4575 4576- CONFIG_FSL_MC_ENET 4577 Enable the MC driver for Layerscape SoCs. 4578 4579Freescale Layerscape Debug Server Support: 4580------------------------------------------- 4581The Freescale Layerscape Debug Server Support supports the loading of 4582"Debug Server firmware" and triggering SP boot-rom. 4583This firmware often needs to be loaded during U-Boot booting. 4584 4585- CONFIG_SYS_MC_RSV_MEM_ALIGN 4586 Define alignment of reserved memory MC requires 4587 4588Reproducible builds 4589------------------- 4590 4591In order to achieve reproducible builds, timestamps used in the U-Boot build 4592process have to be set to a fixed value. 4593 4594This is done using the SOURCE_DATE_EPOCH environment variable. 4595SOURCE_DATE_EPOCH is to be set on the build host's shell, not as a configuration 4596option for U-Boot or an environment variable in U-Boot. 4597 4598SOURCE_DATE_EPOCH should be set to a number of seconds since the epoch, in UTC. 4599 4600Building the Software: 4601====================== 4602 4603Building U-Boot has been tested in several native build environments 4604and in many different cross environments. Of course we cannot support 4605all possibly existing versions of cross development tools in all 4606(potentially obsolete) versions. In case of tool chain problems we 4607recommend to use the ELDK (see http://www.denx.de/wiki/DULG/ELDK) 4608which is extensively used to build and test U-Boot. 4609 4610If you are not using a native environment, it is assumed that you 4611have GNU cross compiling tools available in your path. In this case, 4612you must set the environment variable CROSS_COMPILE in your shell. 4613Note that no changes to the Makefile or any other source files are 4614necessary. For example using the ELDK on a 4xx CPU, please enter: 4615 4616 $ CROSS_COMPILE=ppc_4xx- 4617 $ export CROSS_COMPILE 4618 4619Note: If you wish to generate Windows versions of the utilities in 4620 the tools directory you can use the MinGW toolchain 4621 (http://www.mingw.org). Set your HOST tools to the MinGW 4622 toolchain and execute 'make tools'. For example: 4623 4624 $ make HOSTCC=i586-mingw32msvc-gcc HOSTSTRIP=i586-mingw32msvc-strip tools 4625 4626 Binaries such as tools/mkimage.exe will be created which can 4627 be executed on computers running Windows. 4628 4629U-Boot is intended to be simple to build. After installing the 4630sources you must configure U-Boot for one specific board type. This 4631is done by typing: 4632 4633 make NAME_defconfig 4634 4635where "NAME_defconfig" is the name of one of the existing configu- 4636rations; see boards.cfg for supported names. 4637 4638Note: for some board special configuration names may exist; check if 4639 additional information is available from the board vendor; for 4640 instance, the TQM823L systems are available without (standard) 4641 or with LCD support. You can select such additional "features" 4642 when choosing the configuration, i. e. 4643 4644 make TQM823L_defconfig 4645 - will configure for a plain TQM823L, i. e. no LCD support 4646 4647 make TQM823L_LCD_defconfig 4648 - will configure for a TQM823L with U-Boot console on LCD 4649 4650 etc. 4651 4652 4653Finally, type "make all", and you should get some working U-Boot 4654images ready for download to / installation on your system: 4655 4656- "u-boot.bin" is a raw binary image 4657- "u-boot" is an image in ELF binary format 4658- "u-boot.srec" is in Motorola S-Record format 4659 4660By default the build is performed locally and the objects are saved 4661in the source directory. One of the two methods can be used to change 4662this behavior and build U-Boot to some external directory: 4663 46641. Add O= to the make command line invocations: 4665 4666 make O=/tmp/build distclean 4667 make O=/tmp/build NAME_defconfig 4668 make O=/tmp/build all 4669 46702. Set environment variable KBUILD_OUTPUT to point to the desired location: 4671 4672 export KBUILD_OUTPUT=/tmp/build 4673 make distclean 4674 make NAME_defconfig 4675 make all 4676 4677Note that the command line "O=" setting overrides the KBUILD_OUTPUT environment 4678variable. 4679 4680 4681Please be aware that the Makefiles assume you are using GNU make, so 4682for instance on NetBSD you might need to use "gmake" instead of 4683native "make". 4684 4685 4686If the system board that you have is not listed, then you will need 4687to port U-Boot to your hardware platform. To do this, follow these 4688steps: 4689 46901. Create a new directory to hold your board specific code. Add any 4691 files you need. In your board directory, you will need at least 4692 the "Makefile" and a "<board>.c". 46932. Create a new configuration file "include/configs/<board>.h" for 4694 your board. 46953. If you're porting U-Boot to a new CPU, then also create a new 4696 directory to hold your CPU specific code. Add any files you need. 46974. Run "make <board>_defconfig" with your new name. 46985. Type "make", and you should get a working "u-boot.srec" file 4699 to be installed on your target system. 47006. Debug and solve any problems that might arise. 4701 [Of course, this last step is much harder than it sounds.] 4702 4703 4704Testing of U-Boot Modifications, Ports to New Hardware, etc.: 4705============================================================== 4706 4707If you have modified U-Boot sources (for instance added a new board 4708or support for new devices, a new CPU, etc.) you are expected to 4709provide feedback to the other developers. The feedback normally takes 4710the form of a "patch", i. e. a context diff against a certain (latest 4711official or latest in the git repository) version of U-Boot sources. 4712 4713But before you submit such a patch, please verify that your modifi- 4714cation did not break existing code. At least make sure that *ALL* of 4715the supported boards compile WITHOUT ANY compiler warnings. To do so, 4716just run the buildman script (tools/buildman/buildman), which will 4717configure and build U-Boot for ALL supported system. Be warned, this 4718will take a while. Please see the buildman README, or run 'buildman -H' 4719for documentation. 4720 4721 4722See also "U-Boot Porting Guide" below. 4723 4724 4725Monitor Commands - Overview: 4726============================ 4727 4728go - start application at address 'addr' 4729run - run commands in an environment variable 4730bootm - boot application image from memory 4731bootp - boot image via network using BootP/TFTP protocol 4732bootz - boot zImage from memory 4733tftpboot- boot image via network using TFTP protocol 4734 and env variables "ipaddr" and "serverip" 4735 (and eventually "gatewayip") 4736tftpput - upload a file via network using TFTP protocol 4737rarpboot- boot image via network using RARP/TFTP protocol 4738diskboot- boot from IDE devicebootd - boot default, i.e., run 'bootcmd' 4739loads - load S-Record file over serial line 4740loadb - load binary file over serial line (kermit mode) 4741md - memory display 4742mm - memory modify (auto-incrementing) 4743nm - memory modify (constant address) 4744mw - memory write (fill) 4745cp - memory copy 4746cmp - memory compare 4747crc32 - checksum calculation 4748i2c - I2C sub-system 4749sspi - SPI utility commands 4750base - print or set address offset 4751printenv- print environment variables 4752setenv - set environment variables 4753saveenv - save environment variables to persistent storage 4754protect - enable or disable FLASH write protection 4755erase - erase FLASH memory 4756flinfo - print FLASH memory information 4757nand - NAND memory operations (see doc/README.nand) 4758bdinfo - print Board Info structure 4759iminfo - print header information for application image 4760coninfo - print console devices and informations 4761ide - IDE sub-system 4762loop - infinite loop on address range 4763loopw - infinite write loop on address range 4764mtest - simple RAM test 4765icache - enable or disable instruction cache 4766dcache - enable or disable data cache 4767reset - Perform RESET of the CPU 4768echo - echo args to console 4769version - print monitor version 4770help - print online help 4771? - alias for 'help' 4772 4773 4774Monitor Commands - Detailed Description: 4775======================================== 4776 4777TODO. 4778 4779For now: just type "help <command>". 4780 4781 4782Environment Variables: 4783====================== 4784 4785U-Boot supports user configuration using Environment Variables which 4786can be made persistent by saving to Flash memory. 4787 4788Environment Variables are set using "setenv", printed using 4789"printenv", and saved to Flash using "saveenv". Using "setenv" 4790without a value can be used to delete a variable from the 4791environment. As long as you don't save the environment you are 4792working with an in-memory copy. In case the Flash area containing the 4793environment is erased by accident, a default environment is provided. 4794 4795Some configuration options can be set using Environment Variables. 4796 4797List of environment variables (most likely not complete): 4798 4799 baudrate - see CONFIG_BAUDRATE 4800 4801 bootdelay - see CONFIG_BOOTDELAY 4802 4803 bootcmd - see CONFIG_BOOTCOMMAND 4804 4805 bootargs - Boot arguments when booting an RTOS image 4806 4807 bootfile - Name of the image to load with TFTP 4808 4809 bootm_low - Memory range available for image processing in the bootm 4810 command can be restricted. This variable is given as 4811 a hexadecimal number and defines lowest address allowed 4812 for use by the bootm command. See also "bootm_size" 4813 environment variable. Address defined by "bootm_low" is 4814 also the base of the initial memory mapping for the Linux 4815 kernel -- see the description of CONFIG_SYS_BOOTMAPSZ and 4816 bootm_mapsize. 4817 4818 bootm_mapsize - Size of the initial memory mapping for the Linux kernel. 4819 This variable is given as a hexadecimal number and it 4820 defines the size of the memory region starting at base 4821 address bootm_low that is accessible by the Linux kernel 4822 during early boot. If unset, CONFIG_SYS_BOOTMAPSZ is used 4823 as the default value if it is defined, and bootm_size is 4824 used otherwise. 4825 4826 bootm_size - Memory range available for image processing in the bootm 4827 command can be restricted. This variable is given as 4828 a hexadecimal number and defines the size of the region 4829 allowed for use by the bootm command. See also "bootm_low" 4830 environment variable. 4831 4832 updatefile - Location of the software update file on a TFTP server, used 4833 by the automatic software update feature. Please refer to 4834 documentation in doc/README.update for more details. 4835 4836 autoload - if set to "no" (any string beginning with 'n'), 4837 "bootp" will just load perform a lookup of the 4838 configuration from the BOOTP server, but not try to 4839 load any image using TFTP 4840 4841 autostart - if set to "yes", an image loaded using the "bootp", 4842 "rarpboot", "tftpboot" or "diskboot" commands will 4843 be automatically started (by internally calling 4844 "bootm") 4845 4846 If set to "no", a standalone image passed to the 4847 "bootm" command will be copied to the load address 4848 (and eventually uncompressed), but NOT be started. 4849 This can be used to load and uncompress arbitrary 4850 data. 4851 4852 fdt_high - if set this restricts the maximum address that the 4853 flattened device tree will be copied into upon boot. 4854 For example, if you have a system with 1 GB memory 4855 at physical address 0x10000000, while Linux kernel 4856 only recognizes the first 704 MB as low memory, you 4857 may need to set fdt_high as 0x3C000000 to have the 4858 device tree blob be copied to the maximum address 4859 of the 704 MB low memory, so that Linux kernel can 4860 access it during the boot procedure. 4861 4862 If this is set to the special value 0xFFFFFFFF then 4863 the fdt will not be copied at all on boot. For this 4864 to work it must reside in writable memory, have 4865 sufficient padding on the end of it for u-boot to 4866 add the information it needs into it, and the memory 4867 must be accessible by the kernel. 4868 4869 fdtcontroladdr- if set this is the address of the control flattened 4870 device tree used by U-Boot when CONFIG_OF_CONTROL is 4871 defined. 4872 4873 i2cfast - (PPC405GP|PPC405EP only) 4874 if set to 'y' configures Linux I2C driver for fast 4875 mode (400kHZ). This environment variable is used in 4876 initialization code. So, for changes to be effective 4877 it must be saved and board must be reset. 4878 4879 initrd_high - restrict positioning of initrd images: 4880 If this variable is not set, initrd images will be 4881 copied to the highest possible address in RAM; this 4882 is usually what you want since it allows for 4883 maximum initrd size. If for some reason you want to 4884 make sure that the initrd image is loaded below the 4885 CONFIG_SYS_BOOTMAPSZ limit, you can set this environment 4886 variable to a value of "no" or "off" or "0". 4887 Alternatively, you can set it to a maximum upper 4888 address to use (U-Boot will still check that it 4889 does not overwrite the U-Boot stack and data). 4890 4891 For instance, when you have a system with 16 MB 4892 RAM, and want to reserve 4 MB from use by Linux, 4893 you can do this by adding "mem=12M" to the value of 4894 the "bootargs" variable. However, now you must make 4895 sure that the initrd image is placed in the first 4896 12 MB as well - this can be done with 4897 4898 setenv initrd_high 00c00000 4899 4900 If you set initrd_high to 0xFFFFFFFF, this is an 4901 indication to U-Boot that all addresses are legal 4902 for the Linux kernel, including addresses in flash 4903 memory. In this case U-Boot will NOT COPY the 4904 ramdisk at all. This may be useful to reduce the 4905 boot time on your system, but requires that this 4906 feature is supported by your Linux kernel. 4907 4908 ipaddr - IP address; needed for tftpboot command 4909 4910 loadaddr - Default load address for commands like "bootp", 4911 "rarpboot", "tftpboot", "loadb" or "diskboot" 4912 4913 loads_echo - see CONFIG_LOADS_ECHO 4914 4915 serverip - TFTP server IP address; needed for tftpboot command 4916 4917 bootretry - see CONFIG_BOOT_RETRY_TIME 4918 4919 bootdelaykey - see CONFIG_AUTOBOOT_DELAY_STR 4920 4921 bootstopkey - see CONFIG_AUTOBOOT_STOP_STR 4922 4923 ethprime - controls which interface is used first. 4924 4925 ethact - controls which interface is currently active. 4926 For example you can do the following 4927 4928 => setenv ethact FEC 4929 => ping 192.168.0.1 # traffic sent on FEC 4930 => setenv ethact SCC 4931 => ping 10.0.0.1 # traffic sent on SCC 4932 4933 ethrotate - When set to "no" U-Boot does not go through all 4934 available network interfaces. 4935 It just stays at the currently selected interface. 4936 4937 netretry - When set to "no" each network operation will 4938 either succeed or fail without retrying. 4939 When set to "once" the network operation will 4940 fail when all the available network interfaces 4941 are tried once without success. 4942 Useful on scripts which control the retry operation 4943 themselves. 4944 4945 npe_ucode - set load address for the NPE microcode 4946 4947 silent_linux - If set then Linux will be told to boot silently, by 4948 changing the console to be empty. If "yes" it will be 4949 made silent. If "no" it will not be made silent. If 4950 unset, then it will be made silent if the U-Boot console 4951 is silent. 4952 4953 tftpsrcp - If this is set, the value is used for TFTP's 4954 UDP source port. 4955 4956 tftpdstp - If this is set, the value is used for TFTP's UDP 4957 destination port instead of the Well Know Port 69. 4958 4959 tftpblocksize - Block size to use for TFTP transfers; if not set, 4960 we use the TFTP server's default block size 4961 4962 tftptimeout - Retransmission timeout for TFTP packets (in milli- 4963 seconds, minimum value is 1000 = 1 second). Defines 4964 when a packet is considered to be lost so it has to 4965 be retransmitted. The default is 5000 = 5 seconds. 4966 Lowering this value may make downloads succeed 4967 faster in networks with high packet loss rates or 4968 with unreliable TFTP servers. 4969 4970 tftptimeoutcountmax - maximum count of TFTP timeouts (no 4971 unit, minimum value = 0). Defines how many timeouts 4972 can happen during a single file transfer before that 4973 transfer is aborted. The default is 10, and 0 means 4974 'no timeouts allowed'. Increasing this value may help 4975 downloads succeed with high packet loss rates, or with 4976 unreliable TFTP servers or client hardware. 4977 4978 vlan - When set to a value < 4095 the traffic over 4979 Ethernet is encapsulated/received over 802.1q 4980 VLAN tagged frames. 4981 4982 bootpretryperiod - Period during which BOOTP/DHCP sends retries. 4983 Unsigned value, in milliseconds. If not set, the period will 4984 be either the default (28000), or a value based on 4985 CONFIG_NET_RETRY_COUNT, if defined. This value has 4986 precedence over the valu based on CONFIG_NET_RETRY_COUNT. 4987 4988The following image location variables contain the location of images 4989used in booting. The "Image" column gives the role of the image and is 4990not an environment variable name. The other columns are environment 4991variable names. "File Name" gives the name of the file on a TFTP 4992server, "RAM Address" gives the location in RAM the image will be 4993loaded to, and "Flash Location" gives the image's address in NOR 4994flash or offset in NAND flash. 4995 4996*Note* - these variables don't have to be defined for all boards, some 4997boards currently use other variables for these purposes, and some 4998boards use these variables for other purposes. 4999 5000Image File Name RAM Address Flash Location 5001----- --------- ----------- -------------- 5002u-boot u-boot u-boot_addr_r u-boot_addr 5003Linux kernel bootfile kernel_addr_r kernel_addr 5004device tree blob fdtfile fdt_addr_r fdt_addr 5005ramdisk ramdiskfile ramdisk_addr_r ramdisk_addr 5006 5007The following environment variables may be used and automatically 5008updated by the network boot commands ("bootp" and "rarpboot"), 5009depending the information provided by your boot server: 5010 5011 bootfile - see above 5012 dnsip - IP address of your Domain Name Server 5013 dnsip2 - IP address of your secondary Domain Name Server 5014 gatewayip - IP address of the Gateway (Router) to use 5015 hostname - Target hostname 5016 ipaddr - see above 5017 netmask - Subnet Mask 5018 rootpath - Pathname of the root filesystem on the NFS server 5019 serverip - see above 5020 5021 5022There are two special Environment Variables: 5023 5024 serial# - contains hardware identification information such 5025 as type string and/or serial number 5026 ethaddr - Ethernet address 5027 5028These variables can be set only once (usually during manufacturing of 5029the board). U-Boot refuses to delete or overwrite these variables 5030once they have been set once. 5031 5032 5033Further special Environment Variables: 5034 5035 ver - Contains the U-Boot version string as printed 5036 with the "version" command. This variable is 5037 readonly (see CONFIG_VERSION_VARIABLE). 5038 5039 5040Please note that changes to some configuration parameters may take 5041only effect after the next boot (yes, that's just like Windoze :-). 5042 5043 5044Callback functions for environment variables: 5045--------------------------------------------- 5046 5047For some environment variables, the behavior of u-boot needs to change 5048when their values are changed. This functionality allows functions to 5049be associated with arbitrary variables. On creation, overwrite, or 5050deletion, the callback will provide the opportunity for some side 5051effect to happen or for the change to be rejected. 5052 5053The callbacks are named and associated with a function using the 5054U_BOOT_ENV_CALLBACK macro in your board or driver code. 5055 5056These callbacks are associated with variables in one of two ways. The 5057static list can be added to by defining CONFIG_ENV_CALLBACK_LIST_STATIC 5058in the board configuration to a string that defines a list of 5059associations. The list must be in the following format: 5060 5061 entry = variable_name[:callback_name] 5062 list = entry[,list] 5063 5064If the callback name is not specified, then the callback is deleted. 5065Spaces are also allowed anywhere in the list. 5066 5067Callbacks can also be associated by defining the ".callbacks" variable 5068with the same list format above. Any association in ".callbacks" will 5069override any association in the static list. You can define 5070CONFIG_ENV_CALLBACK_LIST_DEFAULT to a list (string) to define the 5071".callbacks" environment variable in the default or embedded environment. 5072 5073If CONFIG_REGEX is defined, the variable_name above is evaluated as a 5074regular expression. This allows multiple variables to be connected to 5075the same callback without explicitly listing them all out. 5076 5077 5078Command Line Parsing: 5079===================== 5080 5081There are two different command line parsers available with U-Boot: 5082the old "simple" one, and the much more powerful "hush" shell: 5083 5084Old, simple command line parser: 5085-------------------------------- 5086 5087- supports environment variables (through setenv / saveenv commands) 5088- several commands on one line, separated by ';' 5089- variable substitution using "... ${name} ..." syntax 5090- special characters ('$', ';') can be escaped by prefixing with '\', 5091 for example: 5092 setenv bootcmd bootm \${address} 5093- You can also escape text by enclosing in single apostrophes, for example: 5094 setenv addip 'setenv bootargs $bootargs ip=$ipaddr:$serverip:$gatewayip:$netmask:$hostname::off' 5095 5096Hush shell: 5097----------- 5098 5099- similar to Bourne shell, with control structures like 5100 if...then...else...fi, for...do...done; while...do...done, 5101 until...do...done, ... 5102- supports environment ("global") variables (through setenv / saveenv 5103 commands) and local shell variables (through standard shell syntax 5104 "name=value"); only environment variables can be used with "run" 5105 command 5106 5107General rules: 5108-------------- 5109 5110(1) If a command line (or an environment variable executed by a "run" 5111 command) contains several commands separated by semicolon, and 5112 one of these commands fails, then the remaining commands will be 5113 executed anyway. 5114 5115(2) If you execute several variables with one call to run (i. e. 5116 calling run with a list of variables as arguments), any failing 5117 command will cause "run" to terminate, i. e. the remaining 5118 variables are not executed. 5119 5120Note for Redundant Ethernet Interfaces: 5121======================================= 5122 5123Some boards come with redundant Ethernet interfaces; U-Boot supports 5124such configurations and is capable of automatic selection of a 5125"working" interface when needed. MAC assignment works as follows: 5126 5127Network interfaces are numbered eth0, eth1, eth2, ... Corresponding 5128MAC addresses can be stored in the environment as "ethaddr" (=>eth0), 5129"eth1addr" (=>eth1), "eth2addr", ... 5130 5131If the network interface stores some valid MAC address (for instance 5132in SROM), this is used as default address if there is NO correspon- 5133ding setting in the environment; if the corresponding environment 5134variable is set, this overrides the settings in the card; that means: 5135 5136o If the SROM has a valid MAC address, and there is no address in the 5137 environment, the SROM's address is used. 5138 5139o If there is no valid address in the SROM, and a definition in the 5140 environment exists, then the value from the environment variable is 5141 used. 5142 5143o If both the SROM and the environment contain a MAC address, and 5144 both addresses are the same, this MAC address is used. 5145 5146o If both the SROM and the environment contain a MAC address, and the 5147 addresses differ, the value from the environment is used and a 5148 warning is printed. 5149 5150o If neither SROM nor the environment contain a MAC address, an error 5151 is raised. If CONFIG_NET_RANDOM_ETHADDR is defined, then in this case 5152 a random, locally-assigned MAC is used. 5153 5154If Ethernet drivers implement the 'write_hwaddr' function, valid MAC addresses 5155will be programmed into hardware as part of the initialization process. This 5156may be skipped by setting the appropriate 'ethmacskip' environment variable. 5157The naming convention is as follows: 5158"ethmacskip" (=>eth0), "eth1macskip" (=>eth1) etc. 5159 5160Image Formats: 5161============== 5162 5163U-Boot is capable of booting (and performing other auxiliary operations on) 5164images in two formats: 5165 5166New uImage format (FIT) 5167----------------------- 5168 5169Flexible and powerful format based on Flattened Image Tree -- FIT (similar 5170to Flattened Device Tree). It allows the use of images with multiple 5171components (several kernels, ramdisks, etc.), with contents protected by 5172SHA1, MD5 or CRC32. More details are found in the doc/uImage.FIT directory. 5173 5174 5175Old uImage format 5176----------------- 5177 5178Old image format is based on binary files which can be basically anything, 5179preceded by a special header; see the definitions in include/image.h for 5180details; basically, the header defines the following image properties: 5181 5182* Target Operating System (Provisions for OpenBSD, NetBSD, FreeBSD, 5183 4.4BSD, Linux, SVR4, Esix, Solaris, Irix, SCO, Dell, NCR, VxWorks, 5184 LynxOS, pSOS, QNX, RTEMS, INTEGRITY; 5185 Currently supported: Linux, NetBSD, VxWorks, QNX, RTEMS, LynxOS, 5186 INTEGRITY). 5187* Target CPU Architecture (Provisions for Alpha, ARM, AVR32, Intel x86, 5188 IA64, MIPS, NDS32, Nios II, PowerPC, IBM S390, SuperH, Sparc, Sparc 64 Bit; 5189 Currently supported: ARM, AVR32, Intel x86, MIPS, NDS32, Nios II, PowerPC). 5190* Compression Type (uncompressed, gzip, bzip2) 5191* Load Address 5192* Entry Point 5193* Image Name 5194* Image Timestamp 5195 5196The header is marked by a special Magic Number, and both the header 5197and the data portions of the image are secured against corruption by 5198CRC32 checksums. 5199 5200 5201Linux Support: 5202============== 5203 5204Although U-Boot should support any OS or standalone application 5205easily, the main focus has always been on Linux during the design of 5206U-Boot. 5207 5208U-Boot includes many features that so far have been part of some 5209special "boot loader" code within the Linux kernel. Also, any 5210"initrd" images to be used are no longer part of one big Linux image; 5211instead, kernel and "initrd" are separate images. This implementation 5212serves several purposes: 5213 5214- the same features can be used for other OS or standalone 5215 applications (for instance: using compressed images to reduce the 5216 Flash memory footprint) 5217 5218- it becomes much easier to port new Linux kernel versions because 5219 lots of low-level, hardware dependent stuff are done by U-Boot 5220 5221- the same Linux kernel image can now be used with different "initrd" 5222 images; of course this also means that different kernel images can 5223 be run with the same "initrd". This makes testing easier (you don't 5224 have to build a new "zImage.initrd" Linux image when you just 5225 change a file in your "initrd"). Also, a field-upgrade of the 5226 software is easier now. 5227 5228 5229Linux HOWTO: 5230============ 5231 5232Porting Linux to U-Boot based systems: 5233--------------------------------------- 5234 5235U-Boot cannot save you from doing all the necessary modifications to 5236configure the Linux device drivers for use with your target hardware 5237(no, we don't intend to provide a full virtual machine interface to 5238Linux :-). 5239 5240But now you can ignore ALL boot loader code (in arch/powerpc/mbxboot). 5241 5242Just make sure your machine specific header file (for instance 5243include/asm-ppc/tqm8xx.h) includes the same definition of the Board 5244Information structure as we define in include/asm-<arch>/u-boot.h, 5245and make sure that your definition of IMAP_ADDR uses the same value 5246as your U-Boot configuration in CONFIG_SYS_IMMR. 5247 5248Note that U-Boot now has a driver model, a unified model for drivers. 5249If you are adding a new driver, plumb it into driver model. If there 5250is no uclass available, you are encouraged to create one. See 5251doc/driver-model. 5252 5253 5254Configuring the Linux kernel: 5255----------------------------- 5256 5257No specific requirements for U-Boot. Make sure you have some root 5258device (initial ramdisk, NFS) for your target system. 5259 5260 5261Building a Linux Image: 5262----------------------- 5263 5264With U-Boot, "normal" build targets like "zImage" or "bzImage" are 5265not used. If you use recent kernel source, a new build target 5266"uImage" will exist which automatically builds an image usable by 5267U-Boot. Most older kernels also have support for a "pImage" target, 5268which was introduced for our predecessor project PPCBoot and uses a 5269100% compatible format. 5270 5271Example: 5272 5273 make TQM850L_defconfig 5274 make oldconfig 5275 make dep 5276 make uImage 5277 5278The "uImage" build target uses a special tool (in 'tools/mkimage') to 5279encapsulate a compressed Linux kernel image with header information, 5280CRC32 checksum etc. for use with U-Boot. This is what we are doing: 5281 5282* build a standard "vmlinux" kernel image (in ELF binary format): 5283 5284* convert the kernel into a raw binary image: 5285 5286 ${CROSS_COMPILE}-objcopy -O binary \ 5287 -R .note -R .comment \ 5288 -S vmlinux linux.bin 5289 5290* compress the binary image: 5291 5292 gzip -9 linux.bin 5293 5294* package compressed binary image for U-Boot: 5295 5296 mkimage -A ppc -O linux -T kernel -C gzip \ 5297 -a 0 -e 0 -n "Linux Kernel Image" \ 5298 -d linux.bin.gz uImage 5299 5300 5301The "mkimage" tool can also be used to create ramdisk images for use 5302with U-Boot, either separated from the Linux kernel image, or 5303combined into one file. "mkimage" encapsulates the images with a 64 5304byte header containing information about target architecture, 5305operating system, image type, compression method, entry points, time 5306stamp, CRC32 checksums, etc. 5307 5308"mkimage" can be called in two ways: to verify existing images and 5309print the header information, or to build new images. 5310 5311In the first form (with "-l" option) mkimage lists the information 5312contained in the header of an existing U-Boot image; this includes 5313checksum verification: 5314 5315 tools/mkimage -l image 5316 -l ==> list image header information 5317 5318The second form (with "-d" option) is used to build a U-Boot image 5319from a "data file" which is used as image payload: 5320 5321 tools/mkimage -A arch -O os -T type -C comp -a addr -e ep \ 5322 -n name -d data_file image 5323 -A ==> set architecture to 'arch' 5324 -O ==> set operating system to 'os' 5325 -T ==> set image type to 'type' 5326 -C ==> set compression type 'comp' 5327 -a ==> set load address to 'addr' (hex) 5328 -e ==> set entry point to 'ep' (hex) 5329 -n ==> set image name to 'name' 5330 -d ==> use image data from 'datafile' 5331 5332Right now, all Linux kernels for PowerPC systems use the same load 5333address (0x00000000), but the entry point address depends on the 5334kernel version: 5335 5336- 2.2.x kernels have the entry point at 0x0000000C, 5337- 2.3.x and later kernels have the entry point at 0x00000000. 5338 5339So a typical call to build a U-Boot image would read: 5340 5341 -> tools/mkimage -n '2.4.4 kernel for TQM850L' \ 5342 > -A ppc -O linux -T kernel -C gzip -a 0 -e 0 \ 5343 > -d /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/powerpc/coffboot/vmlinux.gz \ 5344 > examples/uImage.TQM850L 5345 Image Name: 2.4.4 kernel for TQM850L 5346 Created: Wed Jul 19 02:34:59 2000 5347 Image Type: PowerPC Linux Kernel Image (gzip compressed) 5348 Data Size: 335725 Bytes = 327.86 kB = 0.32 MB 5349 Load Address: 0x00000000 5350 Entry Point: 0x00000000 5351 5352To verify the contents of the image (or check for corruption): 5353 5354 -> tools/mkimage -l examples/uImage.TQM850L 5355 Image Name: 2.4.4 kernel for TQM850L 5356 Created: Wed Jul 19 02:34:59 2000 5357 Image Type: PowerPC Linux Kernel Image (gzip compressed) 5358 Data Size: 335725 Bytes = 327.86 kB = 0.32 MB 5359 Load Address: 0x00000000 5360 Entry Point: 0x00000000 5361 5362NOTE: for embedded systems where boot time is critical you can trade 5363speed for memory and install an UNCOMPRESSED image instead: this 5364needs more space in Flash, but boots much faster since it does not 5365need to be uncompressed: 5366 5367 -> gunzip /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/powerpc/coffboot/vmlinux.gz 5368 -> tools/mkimage -n '2.4.4 kernel for TQM850L' \ 5369 > -A ppc -O linux -T kernel -C none -a 0 -e 0 \ 5370 > -d /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/powerpc/coffboot/vmlinux \ 5371 > examples/uImage.TQM850L-uncompressed 5372 Image Name: 2.4.4 kernel for TQM850L 5373 Created: Wed Jul 19 02:34:59 2000 5374 Image Type: PowerPC Linux Kernel Image (uncompressed) 5375 Data Size: 792160 Bytes = 773.59 kB = 0.76 MB 5376 Load Address: 0x00000000 5377 Entry Point: 0x00000000 5378 5379 5380Similar you can build U-Boot images from a 'ramdisk.image.gz' file 5381when your kernel is intended to use an initial ramdisk: 5382 5383 -> tools/mkimage -n 'Simple Ramdisk Image' \ 5384 > -A ppc -O linux -T ramdisk -C gzip \ 5385 > -d /LinuxPPC/images/SIMPLE-ramdisk.image.gz examples/simple-initrd 5386 Image Name: Simple Ramdisk Image 5387 Created: Wed Jan 12 14:01:50 2000 5388 Image Type: PowerPC Linux RAMDisk Image (gzip compressed) 5389 Data Size: 566530 Bytes = 553.25 kB = 0.54 MB 5390 Load Address: 0x00000000 5391 Entry Point: 0x00000000 5392 5393The "dumpimage" is a tool to disassemble images built by mkimage. Its "-i" 5394option performs the converse operation of the mkimage's second form (the "-d" 5395option). Given an image built by mkimage, the dumpimage extracts a "data file" 5396from the image: 5397 5398 tools/dumpimage -i image -T type -p position data_file 5399 -i ==> extract from the 'image' a specific 'data_file' 5400 -T ==> set image type to 'type' 5401 -p ==> 'position' (starting at 0) of the 'data_file' inside the 'image' 5402 5403 5404Installing a Linux Image: 5405------------------------- 5406 5407To downloading a U-Boot image over the serial (console) interface, 5408you must convert the image to S-Record format: 5409 5410 objcopy -I binary -O srec examples/image examples/image.srec 5411 5412The 'objcopy' does not understand the information in the U-Boot 5413image header, so the resulting S-Record file will be relative to 5414address 0x00000000. To load it to a given address, you need to 5415specify the target address as 'offset' parameter with the 'loads' 5416command. 5417 5418Example: install the image to address 0x40100000 (which on the 5419TQM8xxL is in the first Flash bank): 5420 5421 => erase 40100000 401FFFFF 5422 5423 .......... done 5424 Erased 8 sectors 5425 5426 => loads 40100000 5427 ## Ready for S-Record download ... 5428 ~>examples/image.srec 5429 1 2 3 4 5 6 7 8 9 10 11 12 13 ... 5430 ... 5431 15989 15990 15991 15992 5432 [file transfer complete] 5433 [connected] 5434 ## Start Addr = 0x00000000 5435 5436 5437You can check the success of the download using the 'iminfo' command; 5438this includes a checksum verification so you can be sure no data 5439corruption happened: 5440 5441 => imi 40100000 5442 5443 ## Checking Image at 40100000 ... 5444 Image Name: 2.2.13 for initrd on TQM850L 5445 Image Type: PowerPC Linux Kernel Image (gzip compressed) 5446 Data Size: 335725 Bytes = 327 kB = 0 MB 5447 Load Address: 00000000 5448 Entry Point: 0000000c 5449 Verifying Checksum ... OK 5450 5451 5452Boot Linux: 5453----------- 5454 5455The "bootm" command is used to boot an application that is stored in 5456memory (RAM or Flash). In case of a Linux kernel image, the contents 5457of the "bootargs" environment variable is passed to the kernel as 5458parameters. You can check and modify this variable using the 5459"printenv" and "setenv" commands: 5460 5461 5462 => printenv bootargs 5463 bootargs=root=/dev/ram 5464 5465 => setenv bootargs root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2 5466 5467 => printenv bootargs 5468 bootargs=root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2 5469 5470 => bootm 40020000 5471 ## Booting Linux kernel at 40020000 ... 5472 Image Name: 2.2.13 for NFS on TQM850L 5473 Image Type: PowerPC Linux Kernel Image (gzip compressed) 5474 Data Size: 381681 Bytes = 372 kB = 0 MB 5475 Load Address: 00000000 5476 Entry Point: 0000000c 5477 Verifying Checksum ... OK 5478 Uncompressing Kernel Image ... OK 5479 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 5480 Boot arguments: root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2 5481 time_init: decrementer frequency = 187500000/60 5482 Calibrating delay loop... 49.77 BogoMIPS 5483 Memory: 15208k available (700k kernel code, 444k data, 32k init) [c0000000,c1000000] 5484 ... 5485 5486If you want to boot a Linux kernel with initial RAM disk, you pass 5487the memory addresses of both the kernel and the initrd image (PPBCOOT 5488format!) to the "bootm" command: 5489 5490 => imi 40100000 40200000 5491 5492 ## Checking Image at 40100000 ... 5493 Image Name: 2.2.13 for initrd on TQM850L 5494 Image Type: PowerPC Linux Kernel Image (gzip compressed) 5495 Data Size: 335725 Bytes = 327 kB = 0 MB 5496 Load Address: 00000000 5497 Entry Point: 0000000c 5498 Verifying Checksum ... OK 5499 5500 ## Checking Image at 40200000 ... 5501 Image Name: Simple Ramdisk Image 5502 Image Type: PowerPC Linux RAMDisk Image (gzip compressed) 5503 Data Size: 566530 Bytes = 553 kB = 0 MB 5504 Load Address: 00000000 5505 Entry Point: 00000000 5506 Verifying Checksum ... OK 5507 5508 => bootm 40100000 40200000 5509 ## Booting Linux kernel at 40100000 ... 5510 Image Name: 2.2.13 for initrd on TQM850L 5511 Image Type: PowerPC Linux Kernel Image (gzip compressed) 5512 Data Size: 335725 Bytes = 327 kB = 0 MB 5513 Load Address: 00000000 5514 Entry Point: 0000000c 5515 Verifying Checksum ... OK 5516 Uncompressing Kernel Image ... OK 5517 ## Loading RAMDisk Image at 40200000 ... 5518 Image Name: Simple Ramdisk Image 5519 Image Type: PowerPC Linux RAMDisk Image (gzip compressed) 5520 Data Size: 566530 Bytes = 553 kB = 0 MB 5521 Load Address: 00000000 5522 Entry Point: 00000000 5523 Verifying Checksum ... OK 5524 Loading Ramdisk ... OK 5525 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 5526 Boot arguments: root=/dev/ram 5527 time_init: decrementer frequency = 187500000/60 5528 Calibrating delay loop... 49.77 BogoMIPS 5529 ... 5530 RAMDISK: Compressed image found at block 0 5531 VFS: Mounted root (ext2 filesystem). 5532 5533 bash# 5534 5535Boot Linux and pass a flat device tree: 5536----------- 5537 5538First, U-Boot must be compiled with the appropriate defines. See the section 5539titled "Linux Kernel Interface" above for a more in depth explanation. The 5540following is an example of how to start a kernel and pass an updated 5541flat device tree: 5542 5543=> print oftaddr 5544oftaddr=0x300000 5545=> print oft 5546oft=oftrees/mpc8540ads.dtb 5547=> tftp $oftaddr $oft 5548Speed: 1000, full duplex 5549Using TSEC0 device 5550TFTP from server 192.168.1.1; our IP address is 192.168.1.101 5551Filename 'oftrees/mpc8540ads.dtb'. 5552Load address: 0x300000 5553Loading: # 5554done 5555Bytes transferred = 4106 (100a hex) 5556=> tftp $loadaddr $bootfile 5557Speed: 1000, full duplex 5558Using TSEC0 device 5559TFTP from server 192.168.1.1; our IP address is 192.168.1.2 5560Filename 'uImage'. 5561Load address: 0x200000 5562Loading:############ 5563done 5564Bytes transferred = 1029407 (fb51f hex) 5565=> print loadaddr 5566loadaddr=200000 5567=> print oftaddr 5568oftaddr=0x300000 5569=> bootm $loadaddr - $oftaddr 5570## Booting image at 00200000 ... 5571 Image Name: Linux-2.6.17-dirty 5572 Image Type: PowerPC Linux Kernel Image (gzip compressed) 5573 Data Size: 1029343 Bytes = 1005.2 kB 5574 Load Address: 00000000 5575 Entry Point: 00000000 5576 Verifying Checksum ... OK 5577 Uncompressing Kernel Image ... OK 5578Booting using flat device tree at 0x300000 5579Using MPC85xx ADS machine description 5580Memory CAM mapping: CAM0=256Mb, CAM1=256Mb, CAM2=0Mb residual: 0Mb 5581[snip] 5582 5583 5584More About U-Boot Image Types: 5585------------------------------ 5586 5587U-Boot supports the following image types: 5588 5589 "Standalone Programs" are directly runnable in the environment 5590 provided by U-Boot; it is expected that (if they behave 5591 well) you can continue to work in U-Boot after return from 5592 the Standalone Program. 5593 "OS Kernel Images" are usually images of some Embedded OS which 5594 will take over control completely. Usually these programs 5595 will install their own set of exception handlers, device 5596 drivers, set up the MMU, etc. - this means, that you cannot 5597 expect to re-enter U-Boot except by resetting the CPU. 5598 "RAMDisk Images" are more or less just data blocks, and their 5599 parameters (address, size) are passed to an OS kernel that is 5600 being started. 5601 "Multi-File Images" contain several images, typically an OS 5602 (Linux) kernel image and one or more data images like 5603 RAMDisks. This construct is useful for instance when you want 5604 to boot over the network using BOOTP etc., where the boot 5605 server provides just a single image file, but you want to get 5606 for instance an OS kernel and a RAMDisk image. 5607 5608 "Multi-File Images" start with a list of image sizes, each 5609 image size (in bytes) specified by an "uint32_t" in network 5610 byte order. This list is terminated by an "(uint32_t)0". 5611 Immediately after the terminating 0 follow the images, one by 5612 one, all aligned on "uint32_t" boundaries (size rounded up to 5613 a multiple of 4 bytes). 5614 5615 "Firmware Images" are binary images containing firmware (like 5616 U-Boot or FPGA images) which usually will be programmed to 5617 flash memory. 5618 5619 "Script files" are command sequences that will be executed by 5620 U-Boot's command interpreter; this feature is especially 5621 useful when you configure U-Boot to use a real shell (hush) 5622 as command interpreter. 5623 5624Booting the Linux zImage: 5625------------------------- 5626 5627On some platforms, it's possible to boot Linux zImage. This is done 5628using the "bootz" command. The syntax of "bootz" command is the same 5629as the syntax of "bootm" command. 5630 5631Note, defining the CONFIG_SUPPORT_RAW_INITRD allows user to supply 5632kernel with raw initrd images. The syntax is slightly different, the 5633address of the initrd must be augmented by it's size, in the following 5634format: "<initrd addres>:<initrd size>". 5635 5636 5637Standalone HOWTO: 5638================= 5639 5640One of the features of U-Boot is that you can dynamically load and 5641run "standalone" applications, which can use some resources of 5642U-Boot like console I/O functions or interrupt services. 5643 5644Two simple examples are included with the sources: 5645 5646"Hello World" Demo: 5647------------------- 5648 5649'examples/hello_world.c' contains a small "Hello World" Demo 5650application; it is automatically compiled when you build U-Boot. 5651It's configured to run at address 0x00040004, so you can play with it 5652like that: 5653 5654 => loads 5655 ## Ready for S-Record download ... 5656 ~>examples/hello_world.srec 5657 1 2 3 4 5 6 7 8 9 10 11 ... 5658 [file transfer complete] 5659 [connected] 5660 ## Start Addr = 0x00040004 5661 5662 => go 40004 Hello World! This is a test. 5663 ## Starting application at 0x00040004 ... 5664 Hello World 5665 argc = 7 5666 argv[0] = "40004" 5667 argv[1] = "Hello" 5668 argv[2] = "World!" 5669 argv[3] = "This" 5670 argv[4] = "is" 5671 argv[5] = "a" 5672 argv[6] = "test." 5673 argv[7] = "<NULL>" 5674 Hit any key to exit ... 5675 5676 ## Application terminated, rc = 0x0 5677 5678Another example, which demonstrates how to register a CPM interrupt 5679handler with the U-Boot code, can be found in 'examples/timer.c'. 5680Here, a CPM timer is set up to generate an interrupt every second. 5681The interrupt service routine is trivial, just printing a '.' 5682character, but this is just a demo program. The application can be 5683controlled by the following keys: 5684 5685 ? - print current values og the CPM Timer registers 5686 b - enable interrupts and start timer 5687 e - stop timer and disable interrupts 5688 q - quit application 5689 5690 => loads 5691 ## Ready for S-Record download ... 5692 ~>examples/timer.srec 5693 1 2 3 4 5 6 7 8 9 10 11 ... 5694 [file transfer complete] 5695 [connected] 5696 ## Start Addr = 0x00040004 5697 5698 => go 40004 5699 ## Starting application at 0x00040004 ... 5700 TIMERS=0xfff00980 5701 Using timer 1 5702 tgcr @ 0xfff00980, tmr @ 0xfff00990, trr @ 0xfff00994, tcr @ 0xfff00998, tcn @ 0xfff0099c, ter @ 0xfff009b0 5703 5704Hit 'b': 5705 [q, b, e, ?] Set interval 1000000 us 5706 Enabling timer 5707Hit '?': 5708 [q, b, e, ?] ........ 5709 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0xef6, ter=0x0 5710Hit '?': 5711 [q, b, e, ?] . 5712 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x2ad4, ter=0x0 5713Hit '?': 5714 [q, b, e, ?] . 5715 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x1efc, ter=0x0 5716Hit '?': 5717 [q, b, e, ?] . 5718 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x169d, ter=0x0 5719Hit 'e': 5720 [q, b, e, ?] ...Stopping timer 5721Hit 'q': 5722 [q, b, e, ?] ## Application terminated, rc = 0x0 5723 5724 5725Minicom warning: 5726================ 5727 5728Over time, many people have reported problems when trying to use the 5729"minicom" terminal emulation program for serial download. I (wd) 5730consider minicom to be broken, and recommend not to use it. Under 5731Unix, I recommend to use C-Kermit for general purpose use (and 5732especially for kermit binary protocol download ("loadb" command), and 5733use "cu" for S-Record download ("loads" command). See 5734http://www.denx.de/wiki/view/DULG/SystemSetup#Section_4.3. 5735for help with kermit. 5736 5737 5738Nevertheless, if you absolutely want to use it try adding this 5739configuration to your "File transfer protocols" section: 5740 5741 Name Program Name U/D FullScr IO-Red. Multi 5742 X kermit /usr/bin/kermit -i -l %l -s Y U Y N N 5743 Y kermit /usr/bin/kermit -i -l %l -r N D Y N N 5744 5745 5746NetBSD Notes: 5747============= 5748 5749Starting at version 0.9.2, U-Boot supports NetBSD both as host 5750(build U-Boot) and target system (boots NetBSD/mpc8xx). 5751 5752Building requires a cross environment; it is known to work on 5753NetBSD/i386 with the cross-powerpc-netbsd-1.3 package (you will also 5754need gmake since the Makefiles are not compatible with BSD make). 5755Note that the cross-powerpc package does not install include files; 5756attempting to build U-Boot will fail because <machine/ansi.h> is 5757missing. This file has to be installed and patched manually: 5758 5759 # cd /usr/pkg/cross/powerpc-netbsd/include 5760 # mkdir powerpc 5761 # ln -s powerpc machine 5762 # cp /usr/src/sys/arch/powerpc/include/ansi.h powerpc/ansi.h 5763 # ${EDIT} powerpc/ansi.h ## must remove __va_list, _BSD_VA_LIST 5764 5765Native builds *don't* work due to incompatibilities between native 5766and U-Boot include files. 5767 5768Booting assumes that (the first part of) the image booted is a 5769stage-2 loader which in turn loads and then invokes the kernel 5770proper. Loader sources will eventually appear in the NetBSD source 5771tree (probably in sys/arc/mpc8xx/stand/u-boot_stage2/); in the 5772meantime, see ftp://ftp.denx.de/pub/u-boot/ppcboot_stage2.tar.gz 5773 5774 5775Implementation Internals: 5776========================= 5777 5778The following is not intended to be a complete description of every 5779implementation detail. However, it should help to understand the 5780inner workings of U-Boot and make it easier to port it to custom 5781hardware. 5782 5783 5784Initial Stack, Global Data: 5785--------------------------- 5786 5787The implementation of U-Boot is complicated by the fact that U-Boot 5788starts running out of ROM (flash memory), usually without access to 5789system RAM (because the memory controller is not initialized yet). 5790This means that we don't have writable Data or BSS segments, and BSS 5791is not initialized as zero. To be able to get a C environment working 5792at all, we have to allocate at least a minimal stack. Implementation 5793options for this are defined and restricted by the CPU used: Some CPU 5794models provide on-chip memory (like the IMMR area on MPC8xx and 5795MPC826x processors), on others (parts of) the data cache can be 5796locked as (mis-) used as memory, etc. 5797 5798 Chris Hallinan posted a good summary of these issues to the 5799 U-Boot mailing list: 5800 5801 Subject: RE: [U-Boot-Users] RE: More On Memory Bank x (nothingness)? 5802 From: "Chris Hallinan" <clh@net1plus.com> 5803 Date: Mon, 10 Feb 2003 16:43:46 -0500 (22:43 MET) 5804 ... 5805 5806 Correct me if I'm wrong, folks, but the way I understand it 5807 is this: Using DCACHE as initial RAM for Stack, etc, does not 5808 require any physical RAM backing up the cache. The cleverness 5809 is that the cache is being used as a temporary supply of 5810 necessary storage before the SDRAM controller is setup. It's 5811 beyond the scope of this list to explain the details, but you 5812 can see how this works by studying the cache architecture and 5813 operation in the architecture and processor-specific manuals. 5814 5815 OCM is On Chip Memory, which I believe the 405GP has 4K. It 5816 is another option for the system designer to use as an 5817 initial stack/RAM area prior to SDRAM being available. Either 5818 option should work for you. Using CS 4 should be fine if your 5819 board designers haven't used it for something that would 5820 cause you grief during the initial boot! It is frequently not 5821 used. 5822 5823 CONFIG_SYS_INIT_RAM_ADDR should be somewhere that won't interfere 5824 with your processor/board/system design. The default value 5825 you will find in any recent u-boot distribution in 5826 walnut.h should work for you. I'd set it to a value larger 5827 than your SDRAM module. If you have a 64MB SDRAM module, set 5828 it above 400_0000. Just make sure your board has no resources 5829 that are supposed to respond to that address! That code in 5830 start.S has been around a while and should work as is when 5831 you get the config right. 5832 5833 -Chris Hallinan 5834 DS4.COM, Inc. 5835 5836It is essential to remember this, since it has some impact on the C 5837code for the initialization procedures: 5838 5839* Initialized global data (data segment) is read-only. Do not attempt 5840 to write it. 5841 5842* Do not use any uninitialized global data (or implicitly initialized 5843 as zero data - BSS segment) at all - this is undefined, initiali- 5844 zation is performed later (when relocating to RAM). 5845 5846* Stack space is very limited. Avoid big data buffers or things like 5847 that. 5848 5849Having only the stack as writable memory limits means we cannot use 5850normal global data to share information between the code. But it 5851turned out that the implementation of U-Boot can be greatly 5852simplified by making a global data structure (gd_t) available to all 5853functions. We could pass a pointer to this data as argument to _all_ 5854functions, but this would bloat the code. Instead we use a feature of 5855the GCC compiler (Global Register Variables) to share the data: we 5856place a pointer (gd) to the global data into a register which we 5857reserve for this purpose. 5858 5859When choosing a register for such a purpose we are restricted by the 5860relevant (E)ABI specifications for the current architecture, and by 5861GCC's implementation. 5862 5863For PowerPC, the following registers have specific use: 5864 R1: stack pointer 5865 R2: reserved for system use 5866 R3-R4: parameter passing and return values 5867 R5-R10: parameter passing 5868 R13: small data area pointer 5869 R30: GOT pointer 5870 R31: frame pointer 5871 5872 (U-Boot also uses R12 as internal GOT pointer. r12 5873 is a volatile register so r12 needs to be reset when 5874 going back and forth between asm and C) 5875 5876 ==> U-Boot will use R2 to hold a pointer to the global data 5877 5878 Note: on PPC, we could use a static initializer (since the 5879 address of the global data structure is known at compile time), 5880 but it turned out that reserving a register results in somewhat 5881 smaller code - although the code savings are not that big (on 5882 average for all boards 752 bytes for the whole U-Boot image, 5883 624 text + 127 data). 5884 5885On ARM, the following registers are used: 5886 5887 R0: function argument word/integer result 5888 R1-R3: function argument word 5889 R9: platform specific 5890 R10: stack limit (used only if stack checking is enabled) 5891 R11: argument (frame) pointer 5892 R12: temporary workspace 5893 R13: stack pointer 5894 R14: link register 5895 R15: program counter 5896 5897 ==> U-Boot will use R9 to hold a pointer to the global data 5898 5899 Note: on ARM, only R_ARM_RELATIVE relocations are supported. 5900 5901On Nios II, the ABI is documented here: 5902 http://www.altera.com/literature/hb/nios2/n2cpu_nii51016.pdf 5903 5904 ==> U-Boot will use gp to hold a pointer to the global data 5905 5906 Note: on Nios II, we give "-G0" option to gcc and don't use gp 5907 to access small data sections, so gp is free. 5908 5909On NDS32, the following registers are used: 5910 5911 R0-R1: argument/return 5912 R2-R5: argument 5913 R15: temporary register for assembler 5914 R16: trampoline register 5915 R28: frame pointer (FP) 5916 R29: global pointer (GP) 5917 R30: link register (LP) 5918 R31: stack pointer (SP) 5919 PC: program counter (PC) 5920 5921 ==> U-Boot will use R10 to hold a pointer to the global data 5922 5923NOTE: DECLARE_GLOBAL_DATA_PTR must be used with file-global scope, 5924or current versions of GCC may "optimize" the code too much. 5925 5926Memory Management: 5927------------------ 5928 5929U-Boot runs in system state and uses physical addresses, i.e. the 5930MMU is not used either for address mapping nor for memory protection. 5931 5932The available memory is mapped to fixed addresses using the memory 5933controller. In this process, a contiguous block is formed for each 5934memory type (Flash, SDRAM, SRAM), even when it consists of several 5935physical memory banks. 5936 5937U-Boot is installed in the first 128 kB of the first Flash bank (on 5938TQM8xxL modules this is the range 0x40000000 ... 0x4001FFFF). After 5939booting and sizing and initializing DRAM, the code relocates itself 5940to the upper end of DRAM. Immediately below the U-Boot code some 5941memory is reserved for use by malloc() [see CONFIG_SYS_MALLOC_LEN 5942configuration setting]. Below that, a structure with global Board 5943Info data is placed, followed by the stack (growing downward). 5944 5945Additionally, some exception handler code is copied to the low 8 kB 5946of DRAM (0x00000000 ... 0x00001FFF). 5947 5948So a typical memory configuration with 16 MB of DRAM could look like 5949this: 5950 5951 0x0000 0000 Exception Vector code 5952 : 5953 0x0000 1FFF 5954 0x0000 2000 Free for Application Use 5955 : 5956 : 5957 5958 : 5959 : 5960 0x00FB FF20 Monitor Stack (Growing downward) 5961 0x00FB FFAC Board Info Data and permanent copy of global data 5962 0x00FC 0000 Malloc Arena 5963 : 5964 0x00FD FFFF 5965 0x00FE 0000 RAM Copy of Monitor Code 5966 ... eventually: LCD or video framebuffer 5967 ... eventually: pRAM (Protected RAM - unchanged by reset) 5968 0x00FF FFFF [End of RAM] 5969 5970 5971System Initialization: 5972---------------------- 5973 5974In the reset configuration, U-Boot starts at the reset entry point 5975(on most PowerPC systems at address 0x00000100). Because of the reset 5976configuration for CS0# this is a mirror of the on board Flash memory. 5977To be able to re-map memory U-Boot then jumps to its link address. 5978To be able to implement the initialization code in C, a (small!) 5979initial stack is set up in the internal Dual Ported RAM (in case CPUs 5980which provide such a feature like MPC8xx or MPC8260), or in a locked 5981part of the data cache. After that, U-Boot initializes the CPU core, 5982the caches and the SIU. 5983 5984Next, all (potentially) available memory banks are mapped using a 5985preliminary mapping. For example, we put them on 512 MB boundaries 5986(multiples of 0x20000000: SDRAM on 0x00000000 and 0x20000000, Flash 5987on 0x40000000 and 0x60000000, SRAM on 0x80000000). Then UPM A is 5988programmed for SDRAM access. Using the temporary configuration, a 5989simple memory test is run that determines the size of the SDRAM 5990banks. 5991 5992When there is more than one SDRAM bank, and the banks are of 5993different size, the largest is mapped first. For equal size, the first 5994bank (CS2#) is mapped first. The first mapping is always for address 59950x00000000, with any additional banks following immediately to create 5996contiguous memory starting from 0. 5997 5998Then, the monitor installs itself at the upper end of the SDRAM area 5999and allocates memory for use by malloc() and for the global Board 6000Info data; also, the exception vector code is copied to the low RAM 6001pages, and the final stack is set up. 6002 6003Only after this relocation will you have a "normal" C environment; 6004until that you are restricted in several ways, mostly because you are 6005running from ROM, and because the code will have to be relocated to a 6006new address in RAM. 6007 6008 6009U-Boot Porting Guide: 6010---------------------- 6011 6012[Based on messages by Jerry Van Baren in the U-Boot-Users mailing 6013list, October 2002] 6014 6015 6016int main(int argc, char *argv[]) 6017{ 6018 sighandler_t no_more_time; 6019 6020 signal(SIGALRM, no_more_time); 6021 alarm(PROJECT_DEADLINE - toSec (3 * WEEK)); 6022 6023 if (available_money > available_manpower) { 6024 Pay consultant to port U-Boot; 6025 return 0; 6026 } 6027 6028 Download latest U-Boot source; 6029 6030 Subscribe to u-boot mailing list; 6031 6032 if (clueless) 6033 email("Hi, I am new to U-Boot, how do I get started?"); 6034 6035 while (learning) { 6036 Read the README file in the top level directory; 6037 Read http://www.denx.de/twiki/bin/view/DULG/Manual; 6038 Read applicable doc/*.README; 6039 Read the source, Luke; 6040 /* find . -name "*.[chS]" | xargs grep -i <keyword> */ 6041 } 6042 6043 if (available_money > toLocalCurrency ($2500)) 6044 Buy a BDI3000; 6045 else 6046 Add a lot of aggravation and time; 6047 6048 if (a similar board exists) { /* hopefully... */ 6049 cp -a board/<similar> board/<myboard> 6050 cp include/configs/<similar>.h include/configs/<myboard>.h 6051 } else { 6052 Create your own board support subdirectory; 6053 Create your own board include/configs/<myboard>.h file; 6054 } 6055 Edit new board/<myboard> files 6056 Edit new include/configs/<myboard>.h 6057 6058 while (!accepted) { 6059 while (!running) { 6060 do { 6061 Add / modify source code; 6062 } until (compiles); 6063 Debug; 6064 if (clueless) 6065 email("Hi, I am having problems..."); 6066 } 6067 Send patch file to the U-Boot email list; 6068 if (reasonable critiques) 6069 Incorporate improvements from email list code review; 6070 else 6071 Defend code as written; 6072 } 6073 6074 return 0; 6075} 6076 6077void no_more_time (int sig) 6078{ 6079 hire_a_guru(); 6080} 6081 6082 6083Coding Standards: 6084----------------- 6085 6086All contributions to U-Boot should conform to the Linux kernel 6087coding style; see the file "Documentation/CodingStyle" and the script 6088"scripts/Lindent" in your Linux kernel source directory. 6089 6090Source files originating from a different project (for example the 6091MTD subsystem) are generally exempt from these guidelines and are not 6092reformatted to ease subsequent migration to newer versions of those 6093sources. 6094 6095Please note that U-Boot is implemented in C (and to some small parts in 6096Assembler); no C++ is used, so please do not use C++ style comments (//) 6097in your code. 6098 6099Please also stick to the following formatting rules: 6100- remove any trailing white space 6101- use TAB characters for indentation and vertical alignment, not spaces 6102- make sure NOT to use DOS '\r\n' line feeds 6103- do not add more than 2 consecutive empty lines to source files 6104- do not add trailing empty lines to source files 6105 6106Submissions which do not conform to the standards may be returned 6107with a request to reformat the changes. 6108 6109 6110Submitting Patches: 6111------------------- 6112 6113Since the number of patches for U-Boot is growing, we need to 6114establish some rules. Submissions which do not conform to these rules 6115may be rejected, even when they contain important and valuable stuff. 6116 6117Please see http://www.denx.de/wiki/U-Boot/Patches for details. 6118 6119Patches shall be sent to the u-boot mailing list <u-boot@lists.denx.de>; 6120see http://lists.denx.de/mailman/listinfo/u-boot 6121 6122When you send a patch, please include the following information with 6123it: 6124 6125* For bug fixes: a description of the bug and how your patch fixes 6126 this bug. Please try to include a way of demonstrating that the 6127 patch actually fixes something. 6128 6129* For new features: a description of the feature and your 6130 implementation. 6131 6132* A CHANGELOG entry as plaintext (separate from the patch) 6133 6134* For major contributions, add a MAINTAINERS file with your 6135 information and associated file and directory references. 6136 6137* When you add support for a new board, don't forget to add a 6138 maintainer e-mail address to the boards.cfg file, too. 6139 6140* If your patch adds new configuration options, don't forget to 6141 document these in the README file. 6142 6143* The patch itself. If you are using git (which is *strongly* 6144 recommended) you can easily generate the patch using the 6145 "git format-patch". If you then use "git send-email" to send it to 6146 the U-Boot mailing list, you will avoid most of the common problems 6147 with some other mail clients. 6148 6149 If you cannot use git, use "diff -purN OLD NEW". If your version of 6150 diff does not support these options, then get the latest version of 6151 GNU diff. 6152 6153 The current directory when running this command shall be the parent 6154 directory of the U-Boot source tree (i. e. please make sure that 6155 your patch includes sufficient directory information for the 6156 affected files). 6157 6158 We prefer patches as plain text. MIME attachments are discouraged, 6159 and compressed attachments must not be used. 6160 6161* If one logical set of modifications affects or creates several 6162 files, all these changes shall be submitted in a SINGLE patch file. 6163 6164* Changesets that contain different, unrelated modifications shall be 6165 submitted as SEPARATE patches, one patch per changeset. 6166 6167 6168Notes: 6169 6170* Before sending the patch, run the buildman script on your patched 6171 source tree and make sure that no errors or warnings are reported 6172 for any of the boards. 6173 6174* Keep your modifications to the necessary minimum: A patch 6175 containing several unrelated changes or arbitrary reformats will be 6176 returned with a request to re-formatting / split it. 6177 6178* If you modify existing code, make sure that your new code does not 6179 add to the memory footprint of the code ;-) Small is beautiful! 6180 When adding new features, these should compile conditionally only 6181 (using #ifdef), and the resulting code with the new feature 6182 disabled must not need more memory than the old code without your 6183 modification. 6184 6185* Remember that there is a size limit of 100 kB per message on the 6186 u-boot mailing list. Bigger patches will be moderated. If they are 6187 reasonable and not too big, they will be acknowledged. But patches 6188 bigger than the size limit should be avoided. 6189