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 selecting 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_DHCP * DHCP support 832 CONFIG_CMD_DIAG * Diagnostics 833 CONFIG_CMD_ECHO echo arguments 834 CONFIG_CMD_EDITENV edit env variable 835 CONFIG_CMD_ELF * bootelf, bootvx 836 CONFIG_CMD_ENV_EXISTS * check existence of env variable 837 CONFIG_CMD_EXPORTENV * export the environment 838 CONFIG_CMD_EXT2 * ext2 command support 839 CONFIG_CMD_EXT4 * ext4 command support 840 CONFIG_CMD_FS_GENERIC * filesystem commands (e.g. load, ls) 841 that work for multiple fs types 842 CONFIG_CMD_FS_UUID * Look up a filesystem UUID 843 CONFIG_CMD_SAVEENV saveenv 844 CONFIG_CMD_FAT * FAT command support 845 CONFIG_CMD_FLASH flinfo, erase, protect 846 CONFIG_CMD_FPGA FPGA device initialization support 847 CONFIG_CMD_GO * the 'go' command (exec code) 848 CONFIG_CMD_GREPENV * search environment 849 CONFIG_CMD_I2C * I2C serial bus support 850 CONFIG_CMD_IMI iminfo 851 CONFIG_CMD_IMLS List all images found in NOR flash 852 CONFIG_CMD_IMLS_NAND * List all images found in NAND flash 853 CONFIG_CMD_IOTRACE * I/O tracing for debugging 854 CONFIG_CMD_IMPORTENV * import an environment 855 CONFIG_CMD_INI * import data from an ini file into the env 856 CONFIG_CMD_IRQ * irqinfo 857 CONFIG_CMD_ITEST Integer/string test of 2 values 858 CONFIG_CMD_JFFS2 * JFFS2 Support 859 CONFIG_CMD_KGDB * kgdb 860 CONFIG_CMD_LDRINFO * ldrinfo (display Blackfin loader) 861 CONFIG_CMD_LINK_LOCAL * link-local IP address auto-configuration 862 (169.254.*.*) 863 CONFIG_CMD_LOADB loadb 864 CONFIG_CMD_LOADS loads 865 CONFIG_CMD_MD5SUM * print md5 message digest 866 (requires CONFIG_CMD_MEMORY and CONFIG_MD5) 867 CONFIG_CMD_MEMINFO * Display detailed memory information 868 CONFIG_CMD_MEMORY md, mm, nm, mw, cp, cmp, crc, base, 869 loop, loopw 870 CONFIG_CMD_MEMTEST * mtest 871 CONFIG_CMD_MISC Misc functions like sleep etc 872 CONFIG_CMD_MMC * MMC memory mapped support 873 CONFIG_CMD_MII * MII utility commands 874 CONFIG_CMD_MTDPARTS * MTD partition support 875 CONFIG_CMD_NAND * NAND support 876 CONFIG_CMD_NET bootp, tftpboot, rarpboot 877 CONFIG_CMD_NFS NFS support 878 CONFIG_CMD_PCA953X * PCA953x I2C gpio commands 879 CONFIG_CMD_PCA953X_INFO * PCA953x I2C gpio info command 880 CONFIG_CMD_PCI * pciinfo 881 CONFIG_CMD_PCMCIA * PCMCIA support 882 CONFIG_CMD_PING * send ICMP ECHO_REQUEST to network 883 host 884 CONFIG_CMD_PORTIO * Port I/O 885 CONFIG_CMD_READ * Read raw data from partition 886 CONFIG_CMD_REGINFO * Register dump 887 CONFIG_CMD_RUN run command in env variable 888 CONFIG_CMD_SANDBOX * sb command to access sandbox features 889 CONFIG_CMD_SAVES * save S record dump 890 CONFIG_SCSI * SCSI Support 891 CONFIG_CMD_SDRAM * print SDRAM configuration information 892 (requires CONFIG_CMD_I2C) 893 CONFIG_CMD_SETGETDCR Support for DCR Register access 894 (4xx only) 895 CONFIG_CMD_SF * Read/write/erase SPI NOR flash 896 CONFIG_CMD_SHA1SUM * print sha1 memory digest 897 (requires CONFIG_CMD_MEMORY) 898 CONFIG_CMD_SOFTSWITCH * Soft switch setting command for BF60x 899 CONFIG_CMD_SOURCE "source" command Support 900 CONFIG_CMD_SPI * SPI serial bus support 901 CONFIG_CMD_TFTPSRV * TFTP transfer in server mode 902 CONFIG_CMD_TFTPPUT * TFTP put command (upload) 903 CONFIG_CMD_TIME * run command and report execution time (ARM specific) 904 CONFIG_CMD_TIMER * access to the system tick timer 905 CONFIG_CMD_USB * USB support 906 CONFIG_CMD_CDP * Cisco Discover Protocol support 907 CONFIG_CMD_MFSL * Microblaze FSL support 908 CONFIG_CMD_XIMG Load part of Multi Image 909 CONFIG_CMD_UUID * Generate random UUID or GUID string 910 911 EXAMPLE: If you want all functions except of network 912 support you can write: 913 914 #include "config_cmd_all.h" 915 #undef CONFIG_CMD_NET 916 917 Other Commands: 918 fdt (flattened device tree) command: CONFIG_OF_LIBFDT 919 920 Note: Don't enable the "icache" and "dcache" commands 921 (configuration option CONFIG_CMD_CACHE) unless you know 922 what you (and your U-Boot users) are doing. Data 923 cache cannot be enabled on systems like the 8xx or 924 8260 (where accesses to the IMMR region must be 925 uncached), and it cannot be disabled on all other 926 systems where we (mis-) use the data cache to hold an 927 initial stack and some data. 928 929 930 XXX - this list needs to get updated! 931 932- Removal of commands 933 If no commands are needed to boot, you can disable 934 CONFIG_CMDLINE to remove them. In this case, the command line 935 will not be available, and when U-Boot wants to execute the 936 boot command (on start-up) it will call board_run_command() 937 instead. This can reduce image size significantly for very 938 simple boot procedures. 939 940- Regular expression support: 941 CONFIG_REGEX 942 If this variable is defined, U-Boot is linked against 943 the SLRE (Super Light Regular Expression) library, 944 which adds regex support to some commands, as for 945 example "env grep" and "setexpr". 946 947- Device tree: 948 CONFIG_OF_CONTROL 949 If this variable is defined, U-Boot will use a device tree 950 to configure its devices, instead of relying on statically 951 compiled #defines in the board file. This option is 952 experimental and only available on a few boards. The device 953 tree is available in the global data as gd->fdt_blob. 954 955 U-Boot needs to get its device tree from somewhere. This can 956 be done using one of the three options below: 957 958 CONFIG_OF_EMBED 959 If this variable is defined, U-Boot will embed a device tree 960 binary in its image. This device tree file should be in the 961 board directory and called <soc>-<board>.dts. The binary file 962 is then picked up in board_init_f() and made available through 963 the global data structure as gd->blob. 964 965 CONFIG_OF_SEPARATE 966 If this variable is defined, U-Boot will build a device tree 967 binary. It will be called u-boot.dtb. Architecture-specific 968 code will locate it at run-time. Generally this works by: 969 970 cat u-boot.bin u-boot.dtb >image.bin 971 972 and in fact, U-Boot does this for you, creating a file called 973 u-boot-dtb.bin which is useful in the common case. You can 974 still use the individual files if you need something more 975 exotic. 976 977 CONFIG_OF_BOARD 978 If this variable is defined, U-Boot will use the device tree 979 provided by the board at runtime instead of embedding one with 980 the image. Only boards defining board_fdt_blob_setup() support 981 this option (see include/fdtdec.h file). 982 983- Watchdog: 984 CONFIG_WATCHDOG 985 If this variable is defined, it enables watchdog 986 support for the SoC. There must be support in the SoC 987 specific code for a watchdog. For the 8xx and 8260 988 CPUs, the SIU Watchdog feature is enabled in the SYPCR 989 register. When supported for a specific SoC is 990 available, then no further board specific code should 991 be needed to use it. 992 993 CONFIG_HW_WATCHDOG 994 When using a watchdog circuitry external to the used 995 SoC, then define this variable and provide board 996 specific code for the "hw_watchdog_reset" function. 997 998 CONFIG_AT91_HW_WDT_TIMEOUT 999 specify the timeout in seconds. default 2 seconds. 1000 1001- U-Boot Version: 1002 CONFIG_VERSION_VARIABLE 1003 If this variable is defined, an environment variable 1004 named "ver" is created by U-Boot showing the U-Boot 1005 version as printed by the "version" command. 1006 Any change to this variable will be reverted at the 1007 next reset. 1008 1009- Real-Time Clock: 1010 1011 When CONFIG_CMD_DATE is selected, the type of the RTC 1012 has to be selected, too. Define exactly one of the 1013 following options: 1014 1015 CONFIG_RTC_MPC8xx - use internal RTC of MPC8xx 1016 CONFIG_RTC_PCF8563 - use Philips PCF8563 RTC 1017 CONFIG_RTC_MC13XXX - use MC13783 or MC13892 RTC 1018 CONFIG_RTC_MC146818 - use MC146818 RTC 1019 CONFIG_RTC_DS1307 - use Maxim, Inc. DS1307 RTC 1020 CONFIG_RTC_DS1337 - use Maxim, Inc. DS1337 RTC 1021 CONFIG_RTC_DS1338 - use Maxim, Inc. DS1338 RTC 1022 CONFIG_RTC_DS1339 - use Maxim, Inc. DS1339 RTC 1023 CONFIG_RTC_DS164x - use Dallas DS164x RTC 1024 CONFIG_RTC_ISL1208 - use Intersil ISL1208 RTC 1025 CONFIG_RTC_MAX6900 - use Maxim, Inc. MAX6900 RTC 1026 CONFIG_SYS_RTC_DS1337_NOOSC - Turn off the OSC output for DS1337 1027 CONFIG_SYS_RV3029_TCR - enable trickle charger on 1028 RV3029 RTC. 1029 1030 Note that if the RTC uses I2C, then the I2C interface 1031 must also be configured. See I2C Support, below. 1032 1033- GPIO Support: 1034 CONFIG_PCA953X - use NXP's PCA953X series I2C GPIO 1035 1036 The CONFIG_SYS_I2C_PCA953X_WIDTH option specifies a list of 1037 chip-ngpio pairs that tell the PCA953X driver the number of 1038 pins supported by a particular chip. 1039 1040 Note that if the GPIO device uses I2C, then the I2C interface 1041 must also be configured. See I2C Support, below. 1042 1043- I/O tracing: 1044 When CONFIG_IO_TRACE is selected, U-Boot intercepts all I/O 1045 accesses and can checksum them or write a list of them out 1046 to memory. See the 'iotrace' command for details. This is 1047 useful for testing device drivers since it can confirm that 1048 the driver behaves the same way before and after a code 1049 change. Currently this is supported on sandbox and arm. To 1050 add support for your architecture, add '#include <iotrace.h>' 1051 to the bottom of arch/<arch>/include/asm/io.h and test. 1052 1053 Example output from the 'iotrace stats' command is below. 1054 Note that if the trace buffer is exhausted, the checksum will 1055 still continue to operate. 1056 1057 iotrace is enabled 1058 Start: 10000000 (buffer start address) 1059 Size: 00010000 (buffer size) 1060 Offset: 00000120 (current buffer offset) 1061 Output: 10000120 (start + offset) 1062 Count: 00000018 (number of trace records) 1063 CRC32: 9526fb66 (CRC32 of all trace records) 1064 1065- Timestamp Support: 1066 1067 When CONFIG_TIMESTAMP is selected, the timestamp 1068 (date and time) of an image is printed by image 1069 commands like bootm or iminfo. This option is 1070 automatically enabled when you select CONFIG_CMD_DATE . 1071 1072- Partition Labels (disklabels) Supported: 1073 Zero or more of the following: 1074 CONFIG_MAC_PARTITION Apple's MacOS partition table. 1075 CONFIG_DOS_PARTITION MS Dos partition table, traditional on the 1076 Intel architecture, USB sticks, etc. 1077 CONFIG_ISO_PARTITION ISO partition table, used on CDROM etc. 1078 CONFIG_EFI_PARTITION GPT partition table, common when EFI is the 1079 bootloader. Note 2TB partition limit; see 1080 disk/part_efi.c 1081 CONFIG_MTD_PARTITIONS Memory Technology Device partition table. 1082 1083 If IDE or SCSI support is enabled (CONFIG_IDE or 1084 CONFIG_SCSI) you must configure support for at 1085 least one non-MTD partition type as well. 1086 1087- IDE Reset method: 1088 CONFIG_IDE_RESET_ROUTINE - this is defined in several 1089 board configurations files but used nowhere! 1090 1091 CONFIG_IDE_RESET - is this is defined, IDE Reset will 1092 be performed by calling the function 1093 ide_set_reset(int reset) 1094 which has to be defined in a board specific file 1095 1096- ATAPI Support: 1097 CONFIG_ATAPI 1098 1099 Set this to enable ATAPI support. 1100 1101- LBA48 Support 1102 CONFIG_LBA48 1103 1104 Set this to enable support for disks larger than 137GB 1105 Also look at CONFIG_SYS_64BIT_LBA. 1106 Whithout these , LBA48 support uses 32bit variables and will 'only' 1107 support disks up to 2.1TB. 1108 1109 CONFIG_SYS_64BIT_LBA: 1110 When enabled, makes the IDE subsystem use 64bit sector addresses. 1111 Default is 32bit. 1112 1113- SCSI Support: 1114 At the moment only there is only support for the 1115 SYM53C8XX SCSI controller; define 1116 CONFIG_SCSI_SYM53C8XX to enable it. 1117 1118 CONFIG_SYS_SCSI_MAX_LUN [8], CONFIG_SYS_SCSI_MAX_SCSI_ID [7] and 1119 CONFIG_SYS_SCSI_MAX_DEVICE [CONFIG_SYS_SCSI_MAX_SCSI_ID * 1120 CONFIG_SYS_SCSI_MAX_LUN] can be adjusted to define the 1121 maximum numbers of LUNs, SCSI ID's and target 1122 devices. 1123 CONFIG_SYS_SCSI_SYM53C8XX_CCF to fix clock timing (80Mhz) 1124 1125 The environment variable 'scsidevs' is set to the number of 1126 SCSI devices found during the last scan. 1127 1128- NETWORK Support (PCI): 1129 CONFIG_E1000 1130 Support for Intel 8254x/8257x gigabit chips. 1131 1132 CONFIG_E1000_SPI 1133 Utility code for direct access to the SPI bus on Intel 8257x. 1134 This does not do anything useful unless you set at least one 1135 of CONFIG_CMD_E1000 or CONFIG_E1000_SPI_GENERIC. 1136 1137 CONFIG_E1000_SPI_GENERIC 1138 Allow generic access to the SPI bus on the Intel 8257x, for 1139 example with the "sspi" command. 1140 1141 CONFIG_CMD_E1000 1142 Management command for E1000 devices. When used on devices 1143 with SPI support you can reprogram the EEPROM from U-Boot. 1144 1145 CONFIG_EEPRO100 1146 Support for Intel 82557/82559/82559ER chips. 1147 Optional CONFIG_EEPRO100_SROM_WRITE enables EEPROM 1148 write routine for first time initialisation. 1149 1150 CONFIG_TULIP 1151 Support for Digital 2114x chips. 1152 Optional CONFIG_TULIP_SELECT_MEDIA for board specific 1153 modem chip initialisation (KS8761/QS6611). 1154 1155 CONFIG_NATSEMI 1156 Support for National dp83815 chips. 1157 1158 CONFIG_NS8382X 1159 Support for National dp8382[01] gigabit chips. 1160 1161- NETWORK Support (other): 1162 1163 CONFIG_DRIVER_AT91EMAC 1164 Support for AT91RM9200 EMAC. 1165 1166 CONFIG_RMII 1167 Define this to use reduced MII inteface 1168 1169 CONFIG_DRIVER_AT91EMAC_QUIET 1170 If this defined, the driver is quiet. 1171 The driver doen't show link status messages. 1172 1173 CONFIG_CALXEDA_XGMAC 1174 Support for the Calxeda XGMAC device 1175 1176 CONFIG_LAN91C96 1177 Support for SMSC's LAN91C96 chips. 1178 1179 CONFIG_LAN91C96_USE_32_BIT 1180 Define this to enable 32 bit addressing 1181 1182 CONFIG_SMC91111 1183 Support for SMSC's LAN91C111 chip 1184 1185 CONFIG_SMC91111_BASE 1186 Define this to hold the physical address 1187 of the device (I/O space) 1188 1189 CONFIG_SMC_USE_32_BIT 1190 Define this if data bus is 32 bits 1191 1192 CONFIG_SMC_USE_IOFUNCS 1193 Define this to use i/o functions instead of macros 1194 (some hardware wont work with macros) 1195 1196 CONFIG_DRIVER_TI_EMAC 1197 Support for davinci emac 1198 1199 CONFIG_SYS_DAVINCI_EMAC_PHY_COUNT 1200 Define this if you have more then 3 PHYs. 1201 1202 CONFIG_FTGMAC100 1203 Support for Faraday's FTGMAC100 Gigabit SoC Ethernet 1204 1205 CONFIG_FTGMAC100_EGIGA 1206 Define this to use GE link update with gigabit PHY. 1207 Define this if FTGMAC100 is connected to gigabit PHY. 1208 If your system has 10/100 PHY only, it might not occur 1209 wrong behavior. Because PHY usually return timeout or 1210 useless data when polling gigabit status and gigabit 1211 control registers. This behavior won't affect the 1212 correctnessof 10/100 link speed update. 1213 1214 CONFIG_SMC911X 1215 Support for SMSC's LAN911x and LAN921x chips 1216 1217 CONFIG_SMC911X_BASE 1218 Define this to hold the physical address 1219 of the device (I/O space) 1220 1221 CONFIG_SMC911X_32_BIT 1222 Define this if data bus is 32 bits 1223 1224 CONFIG_SMC911X_16_BIT 1225 Define this if data bus is 16 bits. If your processor 1226 automatically converts one 32 bit word to two 16 bit 1227 words you may also try CONFIG_SMC911X_32_BIT. 1228 1229 CONFIG_SH_ETHER 1230 Support for Renesas on-chip Ethernet controller 1231 1232 CONFIG_SH_ETHER_USE_PORT 1233 Define the number of ports to be used 1234 1235 CONFIG_SH_ETHER_PHY_ADDR 1236 Define the ETH PHY's address 1237 1238 CONFIG_SH_ETHER_CACHE_WRITEBACK 1239 If this option is set, the driver enables cache flush. 1240 1241- PWM Support: 1242 CONFIG_PWM_IMX 1243 Support for PWM module on the imx6. 1244 1245- TPM Support: 1246 CONFIG_TPM 1247 Support TPM devices. 1248 1249 CONFIG_TPM_TIS_INFINEON 1250 Support for Infineon i2c bus TPM devices. Only one device 1251 per system is supported at this time. 1252 1253 CONFIG_TPM_TIS_I2C_BURST_LIMITATION 1254 Define the burst count bytes upper limit 1255 1256 CONFIG_TPM_ST33ZP24 1257 Support for STMicroelectronics TPM devices. Requires DM_TPM support. 1258 1259 CONFIG_TPM_ST33ZP24_I2C 1260 Support for STMicroelectronics ST33ZP24 I2C devices. 1261 Requires TPM_ST33ZP24 and I2C. 1262 1263 CONFIG_TPM_ST33ZP24_SPI 1264 Support for STMicroelectronics ST33ZP24 SPI devices. 1265 Requires TPM_ST33ZP24 and SPI. 1266 1267 CONFIG_TPM_ATMEL_TWI 1268 Support for Atmel TWI TPM device. Requires I2C support. 1269 1270 CONFIG_TPM_TIS_LPC 1271 Support for generic parallel port TPM devices. Only one device 1272 per system is supported at this time. 1273 1274 CONFIG_TPM_TIS_BASE_ADDRESS 1275 Base address where the generic TPM device is mapped 1276 to. Contemporary x86 systems usually map it at 1277 0xfed40000. 1278 1279 CONFIG_CMD_TPM 1280 Add tpm monitor functions. 1281 Requires CONFIG_TPM. If CONFIG_TPM_AUTH_SESSIONS is set, also 1282 provides monitor access to authorized functions. 1283 1284 CONFIG_TPM 1285 Define this to enable the TPM support library which provides 1286 functional interfaces to some TPM commands. 1287 Requires support for a TPM device. 1288 1289 CONFIG_TPM_AUTH_SESSIONS 1290 Define this to enable authorized functions in the TPM library. 1291 Requires CONFIG_TPM and CONFIG_SHA1. 1292 1293- USB Support: 1294 At the moment only the UHCI host controller is 1295 supported (PIP405, MIP405, MPC5200); define 1296 CONFIG_USB_UHCI to enable it. 1297 define CONFIG_USB_KEYBOARD to enable the USB Keyboard 1298 and define CONFIG_USB_STORAGE to enable the USB 1299 storage devices. 1300 Note: 1301 Supported are USB Keyboards and USB Floppy drives 1302 (TEAC FD-05PUB). 1303 MPC5200 USB requires additional defines: 1304 CONFIG_USB_CLOCK 1305 for 528 MHz Clock: 0x0001bbbb 1306 CONFIG_PSC3_USB 1307 for USB on PSC3 1308 CONFIG_USB_CONFIG 1309 for differential drivers: 0x00001000 1310 for single ended drivers: 0x00005000 1311 for differential drivers on PSC3: 0x00000100 1312 for single ended drivers on PSC3: 0x00004100 1313 CONFIG_SYS_USB_EVENT_POLL 1314 May be defined to allow interrupt polling 1315 instead of using asynchronous interrupts 1316 1317 CONFIG_USB_EHCI_TXFIFO_THRESH enables setting of the 1318 txfilltuning field in the EHCI controller on reset. 1319 1320 CONFIG_USB_DWC2_REG_ADDR the physical CPU address of the DWC2 1321 HW module registers. 1322 1323- USB Device: 1324 Define the below if you wish to use the USB console. 1325 Once firmware is rebuilt from a serial console issue the 1326 command "setenv stdin usbtty; setenv stdout usbtty" and 1327 attach your USB cable. The Unix command "dmesg" should print 1328 it has found a new device. The environment variable usbtty 1329 can be set to gserial or cdc_acm to enable your device to 1330 appear to a USB host as a Linux gserial device or a 1331 Common Device Class Abstract Control Model serial device. 1332 If you select usbtty = gserial you should be able to enumerate 1333 a Linux host by 1334 # modprobe usbserial vendor=0xVendorID product=0xProductID 1335 else if using cdc_acm, simply setting the environment 1336 variable usbtty to be cdc_acm should suffice. The following 1337 might be defined in YourBoardName.h 1338 1339 CONFIG_USB_DEVICE 1340 Define this to build a UDC device 1341 1342 CONFIG_USB_TTY 1343 Define this to have a tty type of device available to 1344 talk to the UDC device 1345 1346 CONFIG_USBD_HS 1347 Define this to enable the high speed support for usb 1348 device and usbtty. If this feature is enabled, a routine 1349 int is_usbd_high_speed(void) 1350 also needs to be defined by the driver to dynamically poll 1351 whether the enumeration has succeded at high speed or full 1352 speed. 1353 1354 CONFIG_SYS_CONSOLE_IS_IN_ENV 1355 Define this if you want stdin, stdout &/or stderr to 1356 be set to usbtty. 1357 1358 mpc8xx: 1359 CONFIG_SYS_USB_EXTC_CLK 0xBLAH 1360 Derive USB clock from external clock "blah" 1361 - CONFIG_SYS_USB_EXTC_CLK 0x02 1362 1363 If you have a USB-IF assigned VendorID then you may wish to 1364 define your own vendor specific values either in BoardName.h 1365 or directly in usbd_vendor_info.h. If you don't define 1366 CONFIG_USBD_MANUFACTURER, CONFIG_USBD_PRODUCT_NAME, 1367 CONFIG_USBD_VENDORID and CONFIG_USBD_PRODUCTID, then U-Boot 1368 should pretend to be a Linux device to it's target host. 1369 1370 CONFIG_USBD_MANUFACTURER 1371 Define this string as the name of your company for 1372 - CONFIG_USBD_MANUFACTURER "my company" 1373 1374 CONFIG_USBD_PRODUCT_NAME 1375 Define this string as the name of your product 1376 - CONFIG_USBD_PRODUCT_NAME "acme usb device" 1377 1378 CONFIG_USBD_VENDORID 1379 Define this as your assigned Vendor ID from the USB 1380 Implementors Forum. This *must* be a genuine Vendor ID 1381 to avoid polluting the USB namespace. 1382 - CONFIG_USBD_VENDORID 0xFFFF 1383 1384 CONFIG_USBD_PRODUCTID 1385 Define this as the unique Product ID 1386 for your device 1387 - CONFIG_USBD_PRODUCTID 0xFFFF 1388 1389- ULPI Layer Support: 1390 The ULPI (UTMI Low Pin (count) Interface) PHYs are supported via 1391 the generic ULPI layer. The generic layer accesses the ULPI PHY 1392 via the platform viewport, so you need both the genric layer and 1393 the viewport enabled. Currently only Chipidea/ARC based 1394 viewport is supported. 1395 To enable the ULPI layer support, define CONFIG_USB_ULPI and 1396 CONFIG_USB_ULPI_VIEWPORT in your board configuration file. 1397 If your ULPI phy needs a different reference clock than the 1398 standard 24 MHz then you have to define CONFIG_ULPI_REF_CLK to 1399 the appropriate value in Hz. 1400 1401- MMC Support: 1402 The MMC controller on the Intel PXA is supported. To 1403 enable this define CONFIG_MMC. The MMC can be 1404 accessed from the boot prompt by mapping the device 1405 to physical memory similar to flash. Command line is 1406 enabled with CONFIG_CMD_MMC. The MMC driver also works with 1407 the FAT fs. This is enabled with CONFIG_CMD_FAT. 1408 1409 CONFIG_SH_MMCIF 1410 Support for Renesas on-chip MMCIF controller 1411 1412 CONFIG_SH_MMCIF_ADDR 1413 Define the base address of MMCIF registers 1414 1415 CONFIG_SH_MMCIF_CLK 1416 Define the clock frequency for MMCIF 1417 1418 CONFIG_SUPPORT_EMMC_BOOT 1419 Enable some additional features of the eMMC boot partitions. 1420 1421 CONFIG_SUPPORT_EMMC_RPMB 1422 Enable the commands for reading, writing and programming the 1423 key for the Replay Protection Memory Block partition in eMMC. 1424 1425- USB Device Firmware Update (DFU) class support: 1426 CONFIG_USB_FUNCTION_DFU 1427 This enables the USB portion of the DFU USB class 1428 1429 CONFIG_CMD_DFU 1430 This enables the command "dfu" which is used to have 1431 U-Boot create a DFU class device via USB. This command 1432 requires that the "dfu_alt_info" environment variable be 1433 set and define the alt settings to expose to the host. 1434 1435 CONFIG_DFU_MMC 1436 This enables support for exposing (e)MMC devices via DFU. 1437 1438 CONFIG_DFU_NAND 1439 This enables support for exposing NAND devices via DFU. 1440 1441 CONFIG_DFU_RAM 1442 This enables support for exposing RAM via DFU. 1443 Note: DFU spec refer to non-volatile memory usage, but 1444 allow usages beyond the scope of spec - here RAM usage, 1445 one that would help mostly the developer. 1446 1447 CONFIG_SYS_DFU_DATA_BUF_SIZE 1448 Dfu transfer uses a buffer before writing data to the 1449 raw storage device. Make the size (in bytes) of this buffer 1450 configurable. The size of this buffer is also configurable 1451 through the "dfu_bufsiz" environment variable. 1452 1453 CONFIG_SYS_DFU_MAX_FILE_SIZE 1454 When updating files rather than the raw storage device, 1455 we use a static buffer to copy the file into and then write 1456 the buffer once we've been given the whole file. Define 1457 this to the maximum filesize (in bytes) for the buffer. 1458 Default is 4 MiB if undefined. 1459 1460 DFU_DEFAULT_POLL_TIMEOUT 1461 Poll timeout [ms], is the timeout a device can send to the 1462 host. The host must wait for this timeout before sending 1463 a subsequent DFU_GET_STATUS request to the device. 1464 1465 DFU_MANIFEST_POLL_TIMEOUT 1466 Poll timeout [ms], which the device sends to the host when 1467 entering dfuMANIFEST state. Host waits this timeout, before 1468 sending again an USB request to the device. 1469 1470- USB Device Android Fastboot support: 1471 CONFIG_USB_FUNCTION_FASTBOOT 1472 This enables the USB part of the fastboot gadget 1473 1474 CONFIG_CMD_FASTBOOT 1475 This enables the command "fastboot" which enables the Android 1476 fastboot mode for the platform's USB device. Fastboot is a USB 1477 protocol for downloading images, flashing and device control 1478 used on Android devices. 1479 See doc/README.android-fastboot for more information. 1480 1481 CONFIG_ANDROID_BOOT_IMAGE 1482 This enables support for booting images which use the Android 1483 image format header. 1484 1485 CONFIG_FASTBOOT_BUF_ADDR 1486 The fastboot protocol requires a large memory buffer for 1487 downloads. Define this to the starting RAM address to use for 1488 downloaded images. 1489 1490 CONFIG_FASTBOOT_BUF_SIZE 1491 The fastboot protocol requires a large memory buffer for 1492 downloads. This buffer should be as large as possible for a 1493 platform. Define this to the size available RAM for fastboot. 1494 1495 CONFIG_FASTBOOT_FLASH 1496 The fastboot protocol includes a "flash" command for writing 1497 the downloaded image to a non-volatile storage device. Define 1498 this to enable the "fastboot flash" command. 1499 1500 CONFIG_FASTBOOT_FLASH_MMC_DEV 1501 The fastboot "flash" command requires additional information 1502 regarding the non-volatile storage device. Define this to 1503 the eMMC device that fastboot should use to store the image. 1504 1505 CONFIG_FASTBOOT_GPT_NAME 1506 The fastboot "flash" command supports writing the downloaded 1507 image to the Protective MBR and the Primary GUID Partition 1508 Table. (Additionally, this downloaded image is post-processed 1509 to generate and write the Backup GUID Partition Table.) 1510 This occurs when the specified "partition name" on the 1511 "fastboot flash" command line matches this value. 1512 The default is "gpt" if undefined. 1513 1514 CONFIG_FASTBOOT_MBR_NAME 1515 The fastboot "flash" command supports writing the downloaded 1516 image to DOS MBR. 1517 This occurs when the "partition name" specified on the 1518 "fastboot flash" command line matches this value. 1519 If not defined the default value "mbr" is used. 1520 1521- Journaling Flash filesystem support: 1522 CONFIG_JFFS2_NAND 1523 Define these for a default partition on a NAND device 1524 1525 CONFIG_SYS_JFFS2_FIRST_SECTOR, 1526 CONFIG_SYS_JFFS2_FIRST_BANK, CONFIG_SYS_JFFS2_NUM_BANKS 1527 Define these for a default partition on a NOR device 1528 1529- FAT(File Allocation Table) filesystem write function support: 1530 CONFIG_FAT_WRITE 1531 1532 Define this to enable support for saving memory data as a 1533 file in FAT formatted partition. 1534 1535 This will also enable the command "fatwrite" enabling the 1536 user to write files to FAT. 1537 1538- FAT(File Allocation Table) filesystem cluster size: 1539 CONFIG_FS_FAT_MAX_CLUSTSIZE 1540 1541 Define the max cluster size for fat operations else 1542 a default value of 65536 will be defined. 1543 1544- Keyboard Support: 1545 See Kconfig help for available keyboard drivers. 1546 1547 CONFIG_KEYBOARD 1548 1549 Define this to enable a custom keyboard support. 1550 This simply calls drv_keyboard_init() which must be 1551 defined in your board-specific files. This option is deprecated 1552 and is only used by novena. For new boards, use driver model 1553 instead. 1554 1555- Video support: 1556 CONFIG_FSL_DIU_FB 1557 Enable the Freescale DIU video driver. Reference boards for 1558 SOCs that have a DIU should define this macro to enable DIU 1559 support, and should also define these other macros: 1560 1561 CONFIG_SYS_DIU_ADDR 1562 CONFIG_VIDEO 1563 CONFIG_CFB_CONSOLE 1564 CONFIG_VIDEO_SW_CURSOR 1565 CONFIG_VGA_AS_SINGLE_DEVICE 1566 CONFIG_VIDEO_LOGO 1567 CONFIG_VIDEO_BMP_LOGO 1568 1569 The DIU driver will look for the 'video-mode' environment 1570 variable, and if defined, enable the DIU as a console during 1571 boot. See the documentation file doc/README.video for a 1572 description of this variable. 1573 1574- LCD Support: CONFIG_LCD 1575 1576 Define this to enable LCD support (for output to LCD 1577 display); also select one of the supported displays 1578 by defining one of these: 1579 1580 CONFIG_ATMEL_LCD: 1581 1582 HITACHI TX09D70VM1CCA, 3.5", 240x320. 1583 1584 CONFIG_NEC_NL6448AC33: 1585 1586 NEC NL6448AC33-18. Active, color, single scan. 1587 1588 CONFIG_NEC_NL6448BC20 1589 1590 NEC NL6448BC20-08. 6.5", 640x480. 1591 Active, color, single scan. 1592 1593 CONFIG_NEC_NL6448BC33_54 1594 1595 NEC NL6448BC33-54. 10.4", 640x480. 1596 Active, color, single scan. 1597 1598 CONFIG_SHARP_16x9 1599 1600 Sharp 320x240. Active, color, single scan. 1601 It isn't 16x9, and I am not sure what it is. 1602 1603 CONFIG_SHARP_LQ64D341 1604 1605 Sharp LQ64D341 display, 640x480. 1606 Active, color, single scan. 1607 1608 CONFIG_HLD1045 1609 1610 HLD1045 display, 640x480. 1611 Active, color, single scan. 1612 1613 CONFIG_OPTREX_BW 1614 1615 Optrex CBL50840-2 NF-FW 99 22 M5 1616 or 1617 Hitachi LMG6912RPFC-00T 1618 or 1619 Hitachi SP14Q002 1620 1621 320x240. Black & white. 1622 1623 CONFIG_LCD_ALIGNMENT 1624 1625 Normally the LCD is page-aligned (typically 4KB). If this is 1626 defined then the LCD will be aligned to this value instead. 1627 For ARM it is sometimes useful to use MMU_SECTION_SIZE 1628 here, since it is cheaper to change data cache settings on 1629 a per-section basis. 1630 1631 1632 CONFIG_LCD_ROTATION 1633 1634 Sometimes, for example if the display is mounted in portrait 1635 mode or even if it's mounted landscape but rotated by 180degree, 1636 we need to rotate our content of the display relative to the 1637 framebuffer, so that user can read the messages which are 1638 printed out. 1639 Once CONFIG_LCD_ROTATION is defined, the lcd_console will be 1640 initialized with a given rotation from "vl_rot" out of 1641 "vidinfo_t" which is provided by the board specific code. 1642 The value for vl_rot is coded as following (matching to 1643 fbcon=rotate:<n> linux-kernel commandline): 1644 0 = no rotation respectively 0 degree 1645 1 = 90 degree rotation 1646 2 = 180 degree rotation 1647 3 = 270 degree rotation 1648 1649 If CONFIG_LCD_ROTATION is not defined, the console will be 1650 initialized with 0degree rotation. 1651 1652 CONFIG_LCD_BMP_RLE8 1653 1654 Support drawing of RLE8-compressed bitmaps on the LCD. 1655 1656 CONFIG_I2C_EDID 1657 1658 Enables an 'i2c edid' command which can read EDID 1659 information over I2C from an attached LCD display. 1660 1661- Splash Screen Support: CONFIG_SPLASH_SCREEN 1662 1663 If this option is set, the environment is checked for 1664 a variable "splashimage". If found, the usual display 1665 of logo, copyright and system information on the LCD 1666 is suppressed and the BMP image at the address 1667 specified in "splashimage" is loaded instead. The 1668 console is redirected to the "nulldev", too. This 1669 allows for a "silent" boot where a splash screen is 1670 loaded very quickly after power-on. 1671 1672 CONFIG_SPLASHIMAGE_GUARD 1673 1674 If this option is set, then U-Boot will prevent the environment 1675 variable "splashimage" from being set to a problematic address 1676 (see doc/README.displaying-bmps). 1677 This option is useful for targets where, due to alignment 1678 restrictions, an improperly aligned BMP image will cause a data 1679 abort. If you think you will not have problems with unaligned 1680 accesses (for example because your toolchain prevents them) 1681 there is no need to set this option. 1682 1683 CONFIG_SPLASH_SCREEN_ALIGN 1684 1685 If this option is set the splash image can be freely positioned 1686 on the screen. Environment variable "splashpos" specifies the 1687 position as "x,y". If a positive number is given it is used as 1688 number of pixel from left/top. If a negative number is given it 1689 is used as number of pixel from right/bottom. You can also 1690 specify 'm' for centering the image. 1691 1692 Example: 1693 setenv splashpos m,m 1694 => image at center of screen 1695 1696 setenv splashpos 30,20 1697 => image at x = 30 and y = 20 1698 1699 setenv splashpos -10,m 1700 => vertically centered image 1701 at x = dspWidth - bmpWidth - 9 1702 1703- Gzip compressed BMP image support: CONFIG_VIDEO_BMP_GZIP 1704 1705 If this option is set, additionally to standard BMP 1706 images, gzipped BMP images can be displayed via the 1707 splashscreen support or the bmp command. 1708 1709- Run length encoded BMP image (RLE8) support: CONFIG_VIDEO_BMP_RLE8 1710 1711 If this option is set, 8-bit RLE compressed BMP images 1712 can be displayed via the splashscreen support or the 1713 bmp command. 1714 1715- Compression support: 1716 CONFIG_GZIP 1717 1718 Enabled by default to support gzip compressed images. 1719 1720 CONFIG_BZIP2 1721 1722 If this option is set, support for bzip2 compressed 1723 images is included. If not, only uncompressed and gzip 1724 compressed images are supported. 1725 1726 NOTE: the bzip2 algorithm requires a lot of RAM, so 1727 the malloc area (as defined by CONFIG_SYS_MALLOC_LEN) should 1728 be at least 4MB. 1729 1730 CONFIG_LZMA 1731 1732 If this option is set, support for lzma compressed 1733 images is included. 1734 1735 Note: The LZMA algorithm adds between 2 and 4KB of code and it 1736 requires an amount of dynamic memory that is given by the 1737 formula: 1738 1739 (1846 + 768 << (lc + lp)) * sizeof(uint16) 1740 1741 Where lc and lp stand for, respectively, Literal context bits 1742 and Literal pos bits. 1743 1744 This value is upper-bounded by 14MB in the worst case. Anyway, 1745 for a ~4MB large kernel image, we have lc=3 and lp=0 for a 1746 total amount of (1846 + 768 << (3 + 0)) * 2 = ~41KB... that is 1747 a very small buffer. 1748 1749 Use the lzmainfo tool to determinate the lc and lp values and 1750 then calculate the amount of needed dynamic memory (ensuring 1751 the appropriate CONFIG_SYS_MALLOC_LEN value). 1752 1753 CONFIG_LZO 1754 1755 If this option is set, support for LZO compressed images 1756 is included. 1757 1758- MII/PHY support: 1759 CONFIG_PHY_ADDR 1760 1761 The address of PHY on MII bus. 1762 1763 CONFIG_PHY_CLOCK_FREQ (ppc4xx) 1764 1765 The clock frequency of the MII bus 1766 1767 CONFIG_PHY_GIGE 1768 1769 If this option is set, support for speed/duplex 1770 detection of gigabit PHY is included. 1771 1772 CONFIG_PHY_RESET_DELAY 1773 1774 Some PHY like Intel LXT971A need extra delay after 1775 reset before any MII register access is possible. 1776 For such PHY, set this option to the usec delay 1777 required. (minimum 300usec for LXT971A) 1778 1779 CONFIG_PHY_CMD_DELAY (ppc4xx) 1780 1781 Some PHY like Intel LXT971A need extra delay after 1782 command issued before MII status register can be read 1783 1784- IP address: 1785 CONFIG_IPADDR 1786 1787 Define a default value for the IP address to use for 1788 the default Ethernet interface, in case this is not 1789 determined through e.g. bootp. 1790 (Environment variable "ipaddr") 1791 1792- Server IP address: 1793 CONFIG_SERVERIP 1794 1795 Defines a default value for the IP address of a TFTP 1796 server to contact when using the "tftboot" command. 1797 (Environment variable "serverip") 1798 1799 CONFIG_KEEP_SERVERADDR 1800 1801 Keeps the server's MAC address, in the env 'serveraddr' 1802 for passing to bootargs (like Linux's netconsole option) 1803 1804- Gateway IP address: 1805 CONFIG_GATEWAYIP 1806 1807 Defines a default value for the IP address of the 1808 default router where packets to other networks are 1809 sent to. 1810 (Environment variable "gatewayip") 1811 1812- Subnet mask: 1813 CONFIG_NETMASK 1814 1815 Defines a default value for the subnet mask (or 1816 routing prefix) which is used to determine if an IP 1817 address belongs to the local subnet or needs to be 1818 forwarded through a router. 1819 (Environment variable "netmask") 1820 1821- Multicast TFTP Mode: 1822 CONFIG_MCAST_TFTP 1823 1824 Defines whether you want to support multicast TFTP as per 1825 rfc-2090; for example to work with atftp. Lets lots of targets 1826 tftp down the same boot image concurrently. Note: the Ethernet 1827 driver in use must provide a function: mcast() to join/leave a 1828 multicast group. 1829 1830- BOOTP Recovery Mode: 1831 CONFIG_BOOTP_RANDOM_DELAY 1832 1833 If you have many targets in a network that try to 1834 boot using BOOTP, you may want to avoid that all 1835 systems send out BOOTP requests at precisely the same 1836 moment (which would happen for instance at recovery 1837 from a power failure, when all systems will try to 1838 boot, thus flooding the BOOTP server. Defining 1839 CONFIG_BOOTP_RANDOM_DELAY causes a random delay to be 1840 inserted before sending out BOOTP requests. The 1841 following delays are inserted then: 1842 1843 1st BOOTP request: delay 0 ... 1 sec 1844 2nd BOOTP request: delay 0 ... 2 sec 1845 3rd BOOTP request: delay 0 ... 4 sec 1846 4th and following 1847 BOOTP requests: delay 0 ... 8 sec 1848 1849 CONFIG_BOOTP_ID_CACHE_SIZE 1850 1851 BOOTP packets are uniquely identified using a 32-bit ID. The 1852 server will copy the ID from client requests to responses and 1853 U-Boot will use this to determine if it is the destination of 1854 an incoming response. Some servers will check that addresses 1855 aren't in use before handing them out (usually using an ARP 1856 ping) and therefore take up to a few hundred milliseconds to 1857 respond. Network congestion may also influence the time it 1858 takes for a response to make it back to the client. If that 1859 time is too long, U-Boot will retransmit requests. In order 1860 to allow earlier responses to still be accepted after these 1861 retransmissions, U-Boot's BOOTP client keeps a small cache of 1862 IDs. The CONFIG_BOOTP_ID_CACHE_SIZE controls the size of this 1863 cache. The default is to keep IDs for up to four outstanding 1864 requests. Increasing this will allow U-Boot to accept offers 1865 from a BOOTP client in networks with unusually high latency. 1866 1867- DHCP Advanced Options: 1868 You can fine tune the DHCP functionality by defining 1869 CONFIG_BOOTP_* symbols: 1870 1871 CONFIG_BOOTP_SUBNETMASK 1872 CONFIG_BOOTP_GATEWAY 1873 CONFIG_BOOTP_HOSTNAME 1874 CONFIG_BOOTP_NISDOMAIN 1875 CONFIG_BOOTP_BOOTPATH 1876 CONFIG_BOOTP_BOOTFILESIZE 1877 CONFIG_BOOTP_DNS 1878 CONFIG_BOOTP_DNS2 1879 CONFIG_BOOTP_SEND_HOSTNAME 1880 CONFIG_BOOTP_NTPSERVER 1881 CONFIG_BOOTP_TIMEOFFSET 1882 CONFIG_BOOTP_VENDOREX 1883 CONFIG_BOOTP_MAY_FAIL 1884 1885 CONFIG_BOOTP_SERVERIP - TFTP server will be the serverip 1886 environment variable, not the BOOTP server. 1887 1888 CONFIG_BOOTP_MAY_FAIL - If the DHCP server is not found 1889 after the configured retry count, the call will fail 1890 instead of starting over. This can be used to fail over 1891 to Link-local IP address configuration if the DHCP server 1892 is not available. 1893 1894 CONFIG_BOOTP_DNS2 - If a DHCP client requests the DNS 1895 serverip from a DHCP server, it is possible that more 1896 than one DNS serverip is offered to the client. 1897 If CONFIG_BOOTP_DNS2 is enabled, the secondary DNS 1898 serverip will be stored in the additional environment 1899 variable "dnsip2". The first DNS serverip is always 1900 stored in the variable "dnsip", when CONFIG_BOOTP_DNS 1901 is defined. 1902 1903 CONFIG_BOOTP_SEND_HOSTNAME - Some DHCP servers are capable 1904 to do a dynamic update of a DNS server. To do this, they 1905 need the hostname of the DHCP requester. 1906 If CONFIG_BOOTP_SEND_HOSTNAME is defined, the content 1907 of the "hostname" environment variable is passed as 1908 option 12 to the DHCP server. 1909 1910 CONFIG_BOOTP_DHCP_REQUEST_DELAY 1911 1912 A 32bit value in microseconds for a delay between 1913 receiving a "DHCP Offer" and sending the "DHCP Request". 1914 This fixes a problem with certain DHCP servers that don't 1915 respond 100% of the time to a "DHCP request". E.g. On an 1916 AT91RM9200 processor running at 180MHz, this delay needed 1917 to be *at least* 15,000 usec before a Windows Server 2003 1918 DHCP server would reply 100% of the time. I recommend at 1919 least 50,000 usec to be safe. The alternative is to hope 1920 that one of the retries will be successful but note that 1921 the DHCP timeout and retry process takes a longer than 1922 this delay. 1923 1924 - Link-local IP address negotiation: 1925 Negotiate with other link-local clients on the local network 1926 for an address that doesn't require explicit configuration. 1927 This is especially useful if a DHCP server cannot be guaranteed 1928 to exist in all environments that the device must operate. 1929 1930 See doc/README.link-local for more information. 1931 1932 - CDP Options: 1933 CONFIG_CDP_DEVICE_ID 1934 1935 The device id used in CDP trigger frames. 1936 1937 CONFIG_CDP_DEVICE_ID_PREFIX 1938 1939 A two character string which is prefixed to the MAC address 1940 of the device. 1941 1942 CONFIG_CDP_PORT_ID 1943 1944 A printf format string which contains the ascii name of 1945 the port. Normally is set to "eth%d" which sets 1946 eth0 for the first Ethernet, eth1 for the second etc. 1947 1948 CONFIG_CDP_CAPABILITIES 1949 1950 A 32bit integer which indicates the device capabilities; 1951 0x00000010 for a normal host which does not forwards. 1952 1953 CONFIG_CDP_VERSION 1954 1955 An ascii string containing the version of the software. 1956 1957 CONFIG_CDP_PLATFORM 1958 1959 An ascii string containing the name of the platform. 1960 1961 CONFIG_CDP_TRIGGER 1962 1963 A 32bit integer sent on the trigger. 1964 1965 CONFIG_CDP_POWER_CONSUMPTION 1966 1967 A 16bit integer containing the power consumption of the 1968 device in .1 of milliwatts. 1969 1970 CONFIG_CDP_APPLIANCE_VLAN_TYPE 1971 1972 A byte containing the id of the VLAN. 1973 1974- Status LED: CONFIG_LED_STATUS 1975 1976 Several configurations allow to display the current 1977 status using a LED. For instance, the LED will blink 1978 fast while running U-Boot code, stop blinking as 1979 soon as a reply to a BOOTP request was received, and 1980 start blinking slow once the Linux kernel is running 1981 (supported by a status LED driver in the Linux 1982 kernel). Defining CONFIG_LED_STATUS enables this 1983 feature in U-Boot. 1984 1985 Additional options: 1986 1987 CONFIG_LED_STATUS_GPIO 1988 The status LED can be connected to a GPIO pin. 1989 In such cases, the gpio_led driver can be used as a 1990 status LED backend implementation. Define CONFIG_LED_STATUS_GPIO 1991 to include the gpio_led driver in the U-Boot binary. 1992 1993 CONFIG_GPIO_LED_INVERTED_TABLE 1994 Some GPIO connected LEDs may have inverted polarity in which 1995 case the GPIO high value corresponds to LED off state and 1996 GPIO low value corresponds to LED on state. 1997 In such cases CONFIG_GPIO_LED_INVERTED_TABLE may be defined 1998 with a list of GPIO LEDs that have inverted polarity. 1999 2000- CAN Support: CONFIG_CAN_DRIVER 2001 2002 Defining CONFIG_CAN_DRIVER enables CAN driver support 2003 on those systems that support this (optional) 2004 feature, like the TQM8xxL modules. 2005 2006- I2C Support: CONFIG_SYS_I2C 2007 2008 This enable the NEW i2c subsystem, and will allow you to use 2009 i2c commands at the u-boot command line (as long as you set 2010 CONFIG_CMD_I2C in CONFIG_COMMANDS) and communicate with i2c 2011 based realtime clock chips or other i2c devices. See 2012 common/cmd_i2c.c for a description of the command line 2013 interface. 2014 2015 ported i2c driver to the new framework: 2016 - drivers/i2c/soft_i2c.c: 2017 - activate first bus with CONFIG_SYS_I2C_SOFT define 2018 CONFIG_SYS_I2C_SOFT_SPEED and CONFIG_SYS_I2C_SOFT_SLAVE 2019 for defining speed and slave address 2020 - activate second bus with I2C_SOFT_DECLARATIONS2 define 2021 CONFIG_SYS_I2C_SOFT_SPEED_2 and CONFIG_SYS_I2C_SOFT_SLAVE_2 2022 for defining speed and slave address 2023 - activate third bus with I2C_SOFT_DECLARATIONS3 define 2024 CONFIG_SYS_I2C_SOFT_SPEED_3 and CONFIG_SYS_I2C_SOFT_SLAVE_3 2025 for defining speed and slave address 2026 - activate fourth bus with I2C_SOFT_DECLARATIONS4 define 2027 CONFIG_SYS_I2C_SOFT_SPEED_4 and CONFIG_SYS_I2C_SOFT_SLAVE_4 2028 for defining speed and slave address 2029 2030 - drivers/i2c/fsl_i2c.c: 2031 - activate i2c driver with CONFIG_SYS_I2C_FSL 2032 define CONFIG_SYS_FSL_I2C_OFFSET for setting the register 2033 offset CONFIG_SYS_FSL_I2C_SPEED for the i2c speed and 2034 CONFIG_SYS_FSL_I2C_SLAVE for the slave addr of the first 2035 bus. 2036 - If your board supports a second fsl i2c bus, define 2037 CONFIG_SYS_FSL_I2C2_OFFSET for the register offset 2038 CONFIG_SYS_FSL_I2C2_SPEED for the speed and 2039 CONFIG_SYS_FSL_I2C2_SLAVE for the slave address of the 2040 second bus. 2041 2042 - drivers/i2c/tegra_i2c.c: 2043 - activate this driver with CONFIG_SYS_I2C_TEGRA 2044 - This driver adds 4 i2c buses with a fix speed from 2045 100000 and the slave addr 0! 2046 2047 - drivers/i2c/ppc4xx_i2c.c 2048 - activate this driver with CONFIG_SYS_I2C_PPC4XX 2049 - CONFIG_SYS_I2C_PPC4XX_CH0 activate hardware channel 0 2050 - CONFIG_SYS_I2C_PPC4XX_CH1 activate hardware channel 1 2051 2052 - drivers/i2c/i2c_mxc.c 2053 - activate this driver with CONFIG_SYS_I2C_MXC 2054 - enable bus 1 with CONFIG_SYS_I2C_MXC_I2C1 2055 - enable bus 2 with CONFIG_SYS_I2C_MXC_I2C2 2056 - enable bus 3 with CONFIG_SYS_I2C_MXC_I2C3 2057 - enable bus 4 with CONFIG_SYS_I2C_MXC_I2C4 2058 - define speed for bus 1 with CONFIG_SYS_MXC_I2C1_SPEED 2059 - define slave for bus 1 with CONFIG_SYS_MXC_I2C1_SLAVE 2060 - define speed for bus 2 with CONFIG_SYS_MXC_I2C2_SPEED 2061 - define slave for bus 2 with CONFIG_SYS_MXC_I2C2_SLAVE 2062 - define speed for bus 3 with CONFIG_SYS_MXC_I2C3_SPEED 2063 - define slave for bus 3 with CONFIG_SYS_MXC_I2C3_SLAVE 2064 - define speed for bus 4 with CONFIG_SYS_MXC_I2C4_SPEED 2065 - define slave for bus 4 with CONFIG_SYS_MXC_I2C4_SLAVE 2066 If those defines are not set, default value is 100000 2067 for speed, and 0 for slave. 2068 2069 - drivers/i2c/rcar_i2c.c: 2070 - activate this driver with CONFIG_SYS_I2C_RCAR 2071 - This driver adds 4 i2c buses 2072 2073 - CONFIG_SYS_RCAR_I2C0_BASE for setting the register channel 0 2074 - CONFIG_SYS_RCAR_I2C0_SPEED for for the speed channel 0 2075 - CONFIG_SYS_RCAR_I2C1_BASE for setting the register channel 1 2076 - CONFIG_SYS_RCAR_I2C1_SPEED for for the speed channel 1 2077 - CONFIG_SYS_RCAR_I2C2_BASE for setting the register channel 2 2078 - CONFIG_SYS_RCAR_I2C2_SPEED for for the speed channel 2 2079 - CONFIG_SYS_RCAR_I2C3_BASE for setting the register channel 3 2080 - CONFIG_SYS_RCAR_I2C3_SPEED for for the speed channel 3 2081 - CONFIF_SYS_RCAR_I2C_NUM_CONTROLLERS for number of i2c buses 2082 2083 - drivers/i2c/sh_i2c.c: 2084 - activate this driver with CONFIG_SYS_I2C_SH 2085 - This driver adds from 2 to 5 i2c buses 2086 2087 - CONFIG_SYS_I2C_SH_BASE0 for setting the register channel 0 2088 - CONFIG_SYS_I2C_SH_SPEED0 for for the speed channel 0 2089 - CONFIG_SYS_I2C_SH_BASE1 for setting the register channel 1 2090 - CONFIG_SYS_I2C_SH_SPEED1 for for the speed channel 1 2091 - CONFIG_SYS_I2C_SH_BASE2 for setting the register channel 2 2092 - CONFIG_SYS_I2C_SH_SPEED2 for for the speed channel 2 2093 - CONFIG_SYS_I2C_SH_BASE3 for setting the register channel 3 2094 - CONFIG_SYS_I2C_SH_SPEED3 for for the speed channel 3 2095 - CONFIG_SYS_I2C_SH_BASE4 for setting the register channel 4 2096 - CONFIG_SYS_I2C_SH_SPEED4 for for the speed channel 4 2097 - CONFIG_SYS_I2C_SH_NUM_CONTROLLERS for number of i2c buses 2098 2099 - drivers/i2c/omap24xx_i2c.c 2100 - activate this driver with CONFIG_SYS_I2C_OMAP24XX 2101 - CONFIG_SYS_OMAP24_I2C_SPEED speed channel 0 2102 - CONFIG_SYS_OMAP24_I2C_SLAVE slave addr channel 0 2103 - CONFIG_SYS_OMAP24_I2C_SPEED1 speed channel 1 2104 - CONFIG_SYS_OMAP24_I2C_SLAVE1 slave addr channel 1 2105 - CONFIG_SYS_OMAP24_I2C_SPEED2 speed channel 2 2106 - CONFIG_SYS_OMAP24_I2C_SLAVE2 slave addr channel 2 2107 - CONFIG_SYS_OMAP24_I2C_SPEED3 speed channel 3 2108 - CONFIG_SYS_OMAP24_I2C_SLAVE3 slave addr channel 3 2109 - CONFIG_SYS_OMAP24_I2C_SPEED4 speed channel 4 2110 - CONFIG_SYS_OMAP24_I2C_SLAVE4 slave addr channel 4 2111 2112 - drivers/i2c/zynq_i2c.c 2113 - activate this driver with CONFIG_SYS_I2C_ZYNQ 2114 - set CONFIG_SYS_I2C_ZYNQ_SPEED for speed setting 2115 - set CONFIG_SYS_I2C_ZYNQ_SLAVE for slave addr 2116 2117 - drivers/i2c/s3c24x0_i2c.c: 2118 - activate this driver with CONFIG_SYS_I2C_S3C24X0 2119 - This driver adds i2c buses (11 for Exynos5250, Exynos5420 2120 9 i2c buses for Exynos4 and 1 for S3C24X0 SoCs from Samsung) 2121 with a fix speed from 100000 and the slave addr 0! 2122 2123 - drivers/i2c/ihs_i2c.c 2124 - activate this driver with CONFIG_SYS_I2C_IHS 2125 - CONFIG_SYS_I2C_IHS_CH0 activate hardware channel 0 2126 - CONFIG_SYS_I2C_IHS_SPEED_0 speed channel 0 2127 - CONFIG_SYS_I2C_IHS_SLAVE_0 slave addr channel 0 2128 - CONFIG_SYS_I2C_IHS_CH1 activate hardware channel 1 2129 - CONFIG_SYS_I2C_IHS_SPEED_1 speed channel 1 2130 - CONFIG_SYS_I2C_IHS_SLAVE_1 slave addr channel 1 2131 - CONFIG_SYS_I2C_IHS_CH2 activate hardware channel 2 2132 - CONFIG_SYS_I2C_IHS_SPEED_2 speed channel 2 2133 - CONFIG_SYS_I2C_IHS_SLAVE_2 slave addr channel 2 2134 - CONFIG_SYS_I2C_IHS_CH3 activate hardware channel 3 2135 - CONFIG_SYS_I2C_IHS_SPEED_3 speed channel 3 2136 - CONFIG_SYS_I2C_IHS_SLAVE_3 slave addr channel 3 2137 - activate dual channel with CONFIG_SYS_I2C_IHS_DUAL 2138 - CONFIG_SYS_I2C_IHS_SPEED_0_1 speed channel 0_1 2139 - CONFIG_SYS_I2C_IHS_SLAVE_0_1 slave addr channel 0_1 2140 - CONFIG_SYS_I2C_IHS_SPEED_1_1 speed channel 1_1 2141 - CONFIG_SYS_I2C_IHS_SLAVE_1_1 slave addr channel 1_1 2142 - CONFIG_SYS_I2C_IHS_SPEED_2_1 speed channel 2_1 2143 - CONFIG_SYS_I2C_IHS_SLAVE_2_1 slave addr channel 2_1 2144 - CONFIG_SYS_I2C_IHS_SPEED_3_1 speed channel 3_1 2145 - CONFIG_SYS_I2C_IHS_SLAVE_3_1 slave addr channel 3_1 2146 2147 additional defines: 2148 2149 CONFIG_SYS_NUM_I2C_BUSES 2150 Hold the number of i2c buses you want to use. 2151 2152 CONFIG_SYS_I2C_DIRECT_BUS 2153 define this, if you don't use i2c muxes on your hardware. 2154 if CONFIG_SYS_I2C_MAX_HOPS is not defined or == 0 you can 2155 omit this define. 2156 2157 CONFIG_SYS_I2C_MAX_HOPS 2158 define how many muxes are maximal consecutively connected 2159 on one i2c bus. If you not use i2c muxes, omit this 2160 define. 2161 2162 CONFIG_SYS_I2C_BUSES 2163 hold a list of buses you want to use, only used if 2164 CONFIG_SYS_I2C_DIRECT_BUS is not defined, for example 2165 a board with CONFIG_SYS_I2C_MAX_HOPS = 1 and 2166 CONFIG_SYS_NUM_I2C_BUSES = 9: 2167 2168 CONFIG_SYS_I2C_BUSES {{0, {I2C_NULL_HOP}}, \ 2169 {0, {{I2C_MUX_PCA9547, 0x70, 1}}}, \ 2170 {0, {{I2C_MUX_PCA9547, 0x70, 2}}}, \ 2171 {0, {{I2C_MUX_PCA9547, 0x70, 3}}}, \ 2172 {0, {{I2C_MUX_PCA9547, 0x70, 4}}}, \ 2173 {0, {{I2C_MUX_PCA9547, 0x70, 5}}}, \ 2174 {1, {I2C_NULL_HOP}}, \ 2175 {1, {{I2C_MUX_PCA9544, 0x72, 1}}}, \ 2176 {1, {{I2C_MUX_PCA9544, 0x72, 2}}}, \ 2177 } 2178 2179 which defines 2180 bus 0 on adapter 0 without a mux 2181 bus 1 on adapter 0 with a PCA9547 on address 0x70 port 1 2182 bus 2 on adapter 0 with a PCA9547 on address 0x70 port 2 2183 bus 3 on adapter 0 with a PCA9547 on address 0x70 port 3 2184 bus 4 on adapter 0 with a PCA9547 on address 0x70 port 4 2185 bus 5 on adapter 0 with a PCA9547 on address 0x70 port 5 2186 bus 6 on adapter 1 without a mux 2187 bus 7 on adapter 1 with a PCA9544 on address 0x72 port 1 2188 bus 8 on adapter 1 with a PCA9544 on address 0x72 port 2 2189 2190 If you do not have i2c muxes on your board, omit this define. 2191 2192- Legacy I2C Support: 2193 If you use the software i2c interface (CONFIG_SYS_I2C_SOFT) 2194 then the following macros need to be defined (examples are 2195 from include/configs/lwmon.h): 2196 2197 I2C_INIT 2198 2199 (Optional). Any commands necessary to enable the I2C 2200 controller or configure ports. 2201 2202 eg: #define I2C_INIT (immr->im_cpm.cp_pbdir |= PB_SCL) 2203 2204 I2C_PORT 2205 2206 (Only for MPC8260 CPU). The I/O port to use (the code 2207 assumes both bits are on the same port). Valid values 2208 are 0..3 for ports A..D. 2209 2210 I2C_ACTIVE 2211 2212 The code necessary to make the I2C data line active 2213 (driven). If the data line is open collector, this 2214 define can be null. 2215 2216 eg: #define I2C_ACTIVE (immr->im_cpm.cp_pbdir |= PB_SDA) 2217 2218 I2C_TRISTATE 2219 2220 The code necessary to make the I2C data line tri-stated 2221 (inactive). If the data line is open collector, this 2222 define can be null. 2223 2224 eg: #define I2C_TRISTATE (immr->im_cpm.cp_pbdir &= ~PB_SDA) 2225 2226 I2C_READ 2227 2228 Code that returns true if the I2C data line is high, 2229 false if it is low. 2230 2231 eg: #define I2C_READ ((immr->im_cpm.cp_pbdat & PB_SDA) != 0) 2232 2233 I2C_SDA(bit) 2234 2235 If <bit> is true, sets the I2C data line high. If it 2236 is false, it clears it (low). 2237 2238 eg: #define I2C_SDA(bit) \ 2239 if(bit) immr->im_cpm.cp_pbdat |= PB_SDA; \ 2240 else immr->im_cpm.cp_pbdat &= ~PB_SDA 2241 2242 I2C_SCL(bit) 2243 2244 If <bit> is true, sets the I2C clock line high. If it 2245 is false, it clears it (low). 2246 2247 eg: #define I2C_SCL(bit) \ 2248 if(bit) immr->im_cpm.cp_pbdat |= PB_SCL; \ 2249 else immr->im_cpm.cp_pbdat &= ~PB_SCL 2250 2251 I2C_DELAY 2252 2253 This delay is invoked four times per clock cycle so this 2254 controls the rate of data transfer. The data rate thus 2255 is 1 / (I2C_DELAY * 4). Often defined to be something 2256 like: 2257 2258 #define I2C_DELAY udelay(2) 2259 2260 CONFIG_SOFT_I2C_GPIO_SCL / CONFIG_SOFT_I2C_GPIO_SDA 2261 2262 If your arch supports the generic GPIO framework (asm/gpio.h), 2263 then you may alternatively define the two GPIOs that are to be 2264 used as SCL / SDA. Any of the previous I2C_xxx macros will 2265 have GPIO-based defaults assigned to them as appropriate. 2266 2267 You should define these to the GPIO value as given directly to 2268 the generic GPIO functions. 2269 2270 CONFIG_SYS_I2C_INIT_BOARD 2271 2272 When a board is reset during an i2c bus transfer 2273 chips might think that the current transfer is still 2274 in progress. On some boards it is possible to access 2275 the i2c SCLK line directly, either by using the 2276 processor pin as a GPIO or by having a second pin 2277 connected to the bus. If this option is defined a 2278 custom i2c_init_board() routine in boards/xxx/board.c 2279 is run early in the boot sequence. 2280 2281 CONFIG_I2C_MULTI_BUS 2282 2283 This option allows the use of multiple I2C buses, each of which 2284 must have a controller. At any point in time, only one bus is 2285 active. To switch to a different bus, use the 'i2c dev' command. 2286 Note that bus numbering is zero-based. 2287 2288 CONFIG_SYS_I2C_NOPROBES 2289 2290 This option specifies a list of I2C devices that will be skipped 2291 when the 'i2c probe' command is issued. If CONFIG_I2C_MULTI_BUS 2292 is set, specify a list of bus-device pairs. Otherwise, specify 2293 a 1D array of device addresses 2294 2295 e.g. 2296 #undef CONFIG_I2C_MULTI_BUS 2297 #define CONFIG_SYS_I2C_NOPROBES {0x50,0x68} 2298 2299 will skip addresses 0x50 and 0x68 on a board with one I2C bus 2300 2301 #define CONFIG_I2C_MULTI_BUS 2302 #define CONFIG_SYS_I2C_NOPROBES {{0,0x50},{0,0x68},{1,0x54}} 2303 2304 will skip addresses 0x50 and 0x68 on bus 0 and address 0x54 on bus 1 2305 2306 CONFIG_SYS_SPD_BUS_NUM 2307 2308 If defined, then this indicates the I2C bus number for DDR SPD. 2309 If not defined, then U-Boot assumes that SPD is on I2C bus 0. 2310 2311 CONFIG_SYS_RTC_BUS_NUM 2312 2313 If defined, then this indicates the I2C bus number for the RTC. 2314 If not defined, then U-Boot assumes that RTC is on I2C bus 0. 2315 2316 CONFIG_SOFT_I2C_READ_REPEATED_START 2317 2318 defining this will force the i2c_read() function in 2319 the soft_i2c driver to perform an I2C repeated start 2320 between writing the address pointer and reading the 2321 data. If this define is omitted the default behaviour 2322 of doing a stop-start sequence will be used. Most I2C 2323 devices can use either method, but some require one or 2324 the other. 2325 2326- SPI Support: CONFIG_SPI 2327 2328 Enables SPI driver (so far only tested with 2329 SPI EEPROM, also an instance works with Crystal A/D and 2330 D/As on the SACSng board) 2331 2332 CONFIG_SH_SPI 2333 2334 Enables the driver for SPI controller on SuperH. Currently 2335 only SH7757 is supported. 2336 2337 CONFIG_SOFT_SPI 2338 2339 Enables a software (bit-bang) SPI driver rather than 2340 using hardware support. This is a general purpose 2341 driver that only requires three general I/O port pins 2342 (two outputs, one input) to function. If this is 2343 defined, the board configuration must define several 2344 SPI configuration items (port pins to use, etc). For 2345 an example, see include/configs/sacsng.h. 2346 2347 CONFIG_HARD_SPI 2348 2349 Enables a hardware SPI driver for general-purpose reads 2350 and writes. As with CONFIG_SOFT_SPI, the board configuration 2351 must define a list of chip-select function pointers. 2352 Currently supported on some MPC8xxx processors. For an 2353 example, see include/configs/mpc8349emds.h. 2354 2355 CONFIG_MXC_SPI 2356 2357 Enables the driver for the SPI controllers on i.MX and MXC 2358 SoCs. Currently i.MX31/35/51 are supported. 2359 2360 CONFIG_SYS_SPI_MXC_WAIT 2361 Timeout for waiting until spi transfer completed. 2362 default: (CONFIG_SYS_HZ/100) /* 10 ms */ 2363 2364- FPGA Support: CONFIG_FPGA 2365 2366 Enables FPGA subsystem. 2367 2368 CONFIG_FPGA_<vendor> 2369 2370 Enables support for specific chip vendors. 2371 (ALTERA, XILINX) 2372 2373 CONFIG_FPGA_<family> 2374 2375 Enables support for FPGA family. 2376 (SPARTAN2, SPARTAN3, VIRTEX2, CYCLONE2, ACEX1K, ACEX) 2377 2378 CONFIG_FPGA_COUNT 2379 2380 Specify the number of FPGA devices to support. 2381 2382 CONFIG_SYS_FPGA_PROG_FEEDBACK 2383 2384 Enable printing of hash marks during FPGA configuration. 2385 2386 CONFIG_SYS_FPGA_CHECK_BUSY 2387 2388 Enable checks on FPGA configuration interface busy 2389 status by the configuration function. This option 2390 will require a board or device specific function to 2391 be written. 2392 2393 CONFIG_FPGA_DELAY 2394 2395 If defined, a function that provides delays in the FPGA 2396 configuration driver. 2397 2398 CONFIG_SYS_FPGA_CHECK_CTRLC 2399 Allow Control-C to interrupt FPGA configuration 2400 2401 CONFIG_SYS_FPGA_CHECK_ERROR 2402 2403 Check for configuration errors during FPGA bitfile 2404 loading. For example, abort during Virtex II 2405 configuration if the INIT_B line goes low (which 2406 indicated a CRC error). 2407 2408 CONFIG_SYS_FPGA_WAIT_INIT 2409 2410 Maximum time to wait for the INIT_B line to de-assert 2411 after PROB_B has been de-asserted during a Virtex II 2412 FPGA configuration sequence. The default time is 500 2413 ms. 2414 2415 CONFIG_SYS_FPGA_WAIT_BUSY 2416 2417 Maximum time to wait for BUSY to de-assert during 2418 Virtex II FPGA configuration. The default is 5 ms. 2419 2420 CONFIG_SYS_FPGA_WAIT_CONFIG 2421 2422 Time to wait after FPGA configuration. The default is 2423 200 ms. 2424 2425- Configuration Management: 2426 CONFIG_BUILD_TARGET 2427 2428 Some SoCs need special image types (e.g. U-Boot binary 2429 with a special header) as build targets. By defining 2430 CONFIG_BUILD_TARGET in the SoC / board header, this 2431 special image will be automatically built upon calling 2432 make / buildman. 2433 2434 CONFIG_IDENT_STRING 2435 2436 If defined, this string will be added to the U-Boot 2437 version information (U_BOOT_VERSION) 2438 2439- Vendor Parameter Protection: 2440 2441 U-Boot considers the values of the environment 2442 variables "serial#" (Board Serial Number) and 2443 "ethaddr" (Ethernet Address) to be parameters that 2444 are set once by the board vendor / manufacturer, and 2445 protects these variables from casual modification by 2446 the user. Once set, these variables are read-only, 2447 and write or delete attempts are rejected. You can 2448 change this behaviour: 2449 2450 If CONFIG_ENV_OVERWRITE is #defined in your config 2451 file, the write protection for vendor parameters is 2452 completely disabled. Anybody can change or delete 2453 these parameters. 2454 2455 Alternatively, if you define _both_ an ethaddr in the 2456 default env _and_ CONFIG_OVERWRITE_ETHADDR_ONCE, a default 2457 Ethernet address is installed in the environment, 2458 which can be changed exactly ONCE by the user. [The 2459 serial# is unaffected by this, i. e. it remains 2460 read-only.] 2461 2462 The same can be accomplished in a more flexible way 2463 for any variable by configuring the type of access 2464 to allow for those variables in the ".flags" variable 2465 or define CONFIG_ENV_FLAGS_LIST_STATIC. 2466 2467- Protected RAM: 2468 CONFIG_PRAM 2469 2470 Define this variable to enable the reservation of 2471 "protected RAM", i. e. RAM which is not overwritten 2472 by U-Boot. Define CONFIG_PRAM to hold the number of 2473 kB you want to reserve for pRAM. You can overwrite 2474 this default value by defining an environment 2475 variable "pram" to the number of kB you want to 2476 reserve. Note that the board info structure will 2477 still show the full amount of RAM. If pRAM is 2478 reserved, a new environment variable "mem" will 2479 automatically be defined to hold the amount of 2480 remaining RAM in a form that can be passed as boot 2481 argument to Linux, for instance like that: 2482 2483 setenv bootargs ... mem=\${mem} 2484 saveenv 2485 2486 This way you can tell Linux not to use this memory, 2487 either, which results in a memory region that will 2488 not be affected by reboots. 2489 2490 *WARNING* If your board configuration uses automatic 2491 detection of the RAM size, you must make sure that 2492 this memory test is non-destructive. So far, the 2493 following board configurations are known to be 2494 "pRAM-clean": 2495 2496 IVMS8, IVML24, SPD8xx, TQM8xxL, 2497 HERMES, IP860, RPXlite, LWMON, 2498 FLAGADM, TQM8260 2499 2500- Access to physical memory region (> 4GB) 2501 Some basic support is provided for operations on memory not 2502 normally accessible to U-Boot - e.g. some architectures 2503 support access to more than 4GB of memory on 32-bit 2504 machines using physical address extension or similar. 2505 Define CONFIG_PHYSMEM to access this basic support, which 2506 currently only supports clearing the memory. 2507 2508- Error Recovery: 2509 CONFIG_PANIC_HANG 2510 2511 Define this variable to stop the system in case of a 2512 fatal error, so that you have to reset it manually. 2513 This is probably NOT a good idea for an embedded 2514 system where you want the system to reboot 2515 automatically as fast as possible, but it may be 2516 useful during development since you can try to debug 2517 the conditions that lead to the situation. 2518 2519 CONFIG_NET_RETRY_COUNT 2520 2521 This variable defines the number of retries for 2522 network operations like ARP, RARP, TFTP, or BOOTP 2523 before giving up the operation. If not defined, a 2524 default value of 5 is used. 2525 2526 CONFIG_ARP_TIMEOUT 2527 2528 Timeout waiting for an ARP reply in milliseconds. 2529 2530 CONFIG_NFS_TIMEOUT 2531 2532 Timeout in milliseconds used in NFS protocol. 2533 If you encounter "ERROR: Cannot umount" in nfs command, 2534 try longer timeout such as 2535 #define CONFIG_NFS_TIMEOUT 10000UL 2536 2537- Command Interpreter: 2538 CONFIG_AUTO_COMPLETE 2539 2540 Enable auto completion of commands using TAB. 2541 2542 CONFIG_SYS_PROMPT_HUSH_PS2 2543 2544 This defines the secondary prompt string, which is 2545 printed when the command interpreter needs more input 2546 to complete a command. Usually "> ". 2547 2548 Note: 2549 2550 In the current implementation, the local variables 2551 space and global environment variables space are 2552 separated. Local variables are those you define by 2553 simply typing `name=value'. To access a local 2554 variable later on, you have write `$name' or 2555 `${name}'; to execute the contents of a variable 2556 directly type `$name' at the command prompt. 2557 2558 Global environment variables are those you use 2559 setenv/printenv to work with. To run a command stored 2560 in such a variable, you need to use the run command, 2561 and you must not use the '$' sign to access them. 2562 2563 To store commands and special characters in a 2564 variable, please use double quotation marks 2565 surrounding the whole text of the variable, instead 2566 of the backslashes before semicolons and special 2567 symbols. 2568 2569- Command Line Editing and History: 2570 CONFIG_CMDLINE_EDITING 2571 2572 Enable editing and History functions for interactive 2573 command line input operations 2574 2575- Command Line PS1/PS2 support: 2576 CONFIG_CMDLINE_PS_SUPPORT 2577 2578 Enable support for changing the command prompt string 2579 at run-time. Only static string is supported so far. 2580 The string is obtained from environment variables PS1 2581 and PS2. 2582 2583- Default Environment: 2584 CONFIG_EXTRA_ENV_SETTINGS 2585 2586 Define this to contain any number of null terminated 2587 strings (variable = value pairs) that will be part of 2588 the default environment compiled into the boot image. 2589 2590 For example, place something like this in your 2591 board's config file: 2592 2593 #define CONFIG_EXTRA_ENV_SETTINGS \ 2594 "myvar1=value1\0" \ 2595 "myvar2=value2\0" 2596 2597 Warning: This method is based on knowledge about the 2598 internal format how the environment is stored by the 2599 U-Boot code. This is NOT an official, exported 2600 interface! Although it is unlikely that this format 2601 will change soon, there is no guarantee either. 2602 You better know what you are doing here. 2603 2604 Note: overly (ab)use of the default environment is 2605 discouraged. Make sure to check other ways to preset 2606 the environment like the "source" command or the 2607 boot command first. 2608 2609 CONFIG_ENV_VARS_UBOOT_CONFIG 2610 2611 Define this in order to add variables describing the 2612 U-Boot build configuration to the default environment. 2613 These will be named arch, cpu, board, vendor, and soc. 2614 2615 Enabling this option will cause the following to be defined: 2616 2617 - CONFIG_SYS_ARCH 2618 - CONFIG_SYS_CPU 2619 - CONFIG_SYS_BOARD 2620 - CONFIG_SYS_VENDOR 2621 - CONFIG_SYS_SOC 2622 2623 CONFIG_ENV_VARS_UBOOT_RUNTIME_CONFIG 2624 2625 Define this in order to add variables describing certain 2626 run-time determined information about the hardware to the 2627 environment. These will be named board_name, board_rev. 2628 2629 CONFIG_DELAY_ENVIRONMENT 2630 2631 Normally the environment is loaded when the board is 2632 initialised so that it is available to U-Boot. This inhibits 2633 that so that the environment is not available until 2634 explicitly loaded later by U-Boot code. With CONFIG_OF_CONTROL 2635 this is instead controlled by the value of 2636 /config/load-environment. 2637 2638- DataFlash Support: 2639 CONFIG_HAS_DATAFLASH 2640 2641 Defining this option enables DataFlash features and 2642 allows to read/write in Dataflash via the standard 2643 commands cp, md... 2644 2645- Serial Flash support 2646 CONFIG_CMD_SF 2647 2648 Defining this option enables SPI flash commands 2649 'sf probe/read/write/erase/update'. 2650 2651 Usage requires an initial 'probe' to define the serial 2652 flash parameters, followed by read/write/erase/update 2653 commands. 2654 2655 The following defaults may be provided by the platform 2656 to handle the common case when only a single serial 2657 flash is present on the system. 2658 2659 CONFIG_SF_DEFAULT_BUS Bus identifier 2660 CONFIG_SF_DEFAULT_CS Chip-select 2661 CONFIG_SF_DEFAULT_MODE (see include/spi.h) 2662 CONFIG_SF_DEFAULT_SPEED in Hz 2663 2664 CONFIG_CMD_SF_TEST 2665 2666 Define this option to include a destructive SPI flash 2667 test ('sf test'). 2668 2669 CONFIG_SF_DUAL_FLASH Dual flash memories 2670 2671 Define this option to use dual flash support where two flash 2672 memories can be connected with a given cs line. 2673 Currently Xilinx Zynq qspi supports these type of connections. 2674 2675- SystemACE Support: 2676 CONFIG_SYSTEMACE 2677 2678 Adding this option adds support for Xilinx SystemACE 2679 chips attached via some sort of local bus. The address 2680 of the chip must also be defined in the 2681 CONFIG_SYS_SYSTEMACE_BASE macro. For example: 2682 2683 #define CONFIG_SYSTEMACE 2684 #define CONFIG_SYS_SYSTEMACE_BASE 0xf0000000 2685 2686 When SystemACE support is added, the "ace" device type 2687 becomes available to the fat commands, i.e. fatls. 2688 2689- TFTP Fixed UDP Port: 2690 CONFIG_TFTP_PORT 2691 2692 If this is defined, the environment variable tftpsrcp 2693 is used to supply the TFTP UDP source port value. 2694 If tftpsrcp isn't defined, the normal pseudo-random port 2695 number generator is used. 2696 2697 Also, the environment variable tftpdstp is used to supply 2698 the TFTP UDP destination port value. If tftpdstp isn't 2699 defined, the normal port 69 is used. 2700 2701 The purpose for tftpsrcp is to allow a TFTP server to 2702 blindly start the TFTP transfer using the pre-configured 2703 target IP address and UDP port. This has the effect of 2704 "punching through" the (Windows XP) firewall, allowing 2705 the remainder of the TFTP transfer to proceed normally. 2706 A better solution is to properly configure the firewall, 2707 but sometimes that is not allowed. 2708 2709- Hashing support: 2710 CONFIG_HASH_VERIFY 2711 2712 Enable the hash verify command (hash -v). This adds to code 2713 size a little. 2714 2715 Note: There is also a sha1sum command, which should perhaps 2716 be deprecated in favour of 'hash sha1'. 2717 2718- bootcount support: 2719 CONFIG_BOOTCOUNT_LIMIT 2720 2721 This enables the bootcounter support, see: 2722 http://www.denx.de/wiki/DULG/UBootBootCountLimit 2723 2724 CONFIG_AT91SAM9XE 2725 enable special bootcounter support on at91sam9xe based boards. 2726 CONFIG_SOC_DA8XX 2727 enable special bootcounter support on da850 based boards. 2728 CONFIG_BOOTCOUNT_RAM 2729 enable support for the bootcounter in RAM 2730 CONFIG_BOOTCOUNT_I2C 2731 enable support for the bootcounter on an i2c (like RTC) device. 2732 CONFIG_SYS_I2C_RTC_ADDR = i2c chip address 2733 CONFIG_SYS_BOOTCOUNT_ADDR = i2c addr which is used for 2734 the bootcounter. 2735 CONFIG_BOOTCOUNT_ALEN = address len 2736 2737- Show boot progress: 2738 CONFIG_SHOW_BOOT_PROGRESS 2739 2740 Defining this option allows to add some board- 2741 specific code (calling a user-provided function 2742 "show_boot_progress(int)") that enables you to show 2743 the system's boot progress on some display (for 2744 example, some LED's) on your board. At the moment, 2745 the following checkpoints are implemented: 2746 2747 2748Legacy uImage format: 2749 2750 Arg Where When 2751 1 common/cmd_bootm.c before attempting to boot an image 2752 -1 common/cmd_bootm.c Image header has bad magic number 2753 2 common/cmd_bootm.c Image header has correct magic number 2754 -2 common/cmd_bootm.c Image header has bad checksum 2755 3 common/cmd_bootm.c Image header has correct checksum 2756 -3 common/cmd_bootm.c Image data has bad checksum 2757 4 common/cmd_bootm.c Image data has correct checksum 2758 -4 common/cmd_bootm.c Image is for unsupported architecture 2759 5 common/cmd_bootm.c Architecture check OK 2760 -5 common/cmd_bootm.c Wrong Image Type (not kernel, multi) 2761 6 common/cmd_bootm.c Image Type check OK 2762 -6 common/cmd_bootm.c gunzip uncompression error 2763 -7 common/cmd_bootm.c Unimplemented compression type 2764 7 common/cmd_bootm.c Uncompression OK 2765 8 common/cmd_bootm.c No uncompress/copy overwrite error 2766 -9 common/cmd_bootm.c Unsupported OS (not Linux, BSD, VxWorks, QNX) 2767 2768 9 common/image.c Start initial ramdisk verification 2769 -10 common/image.c Ramdisk header has bad magic number 2770 -11 common/image.c Ramdisk header has bad checksum 2771 10 common/image.c Ramdisk header is OK 2772 -12 common/image.c Ramdisk data has bad checksum 2773 11 common/image.c Ramdisk data has correct checksum 2774 12 common/image.c Ramdisk verification complete, start loading 2775 -13 common/image.c Wrong Image Type (not PPC Linux ramdisk) 2776 13 common/image.c Start multifile image verification 2777 14 common/image.c No initial ramdisk, no multifile, continue. 2778 2779 15 arch/<arch>/lib/bootm.c All preparation done, transferring control to OS 2780 2781 -30 arch/powerpc/lib/board.c Fatal error, hang the system 2782 -31 post/post.c POST test failed, detected by post_output_backlog() 2783 -32 post/post.c POST test failed, detected by post_run_single() 2784 2785 34 common/cmd_doc.c before loading a Image from a DOC device 2786 -35 common/cmd_doc.c Bad usage of "doc" command 2787 35 common/cmd_doc.c correct usage of "doc" command 2788 -36 common/cmd_doc.c No boot device 2789 36 common/cmd_doc.c correct boot device 2790 -37 common/cmd_doc.c Unknown Chip ID on boot device 2791 37 common/cmd_doc.c correct chip ID found, device available 2792 -38 common/cmd_doc.c Read Error on boot device 2793 38 common/cmd_doc.c reading Image header from DOC device OK 2794 -39 common/cmd_doc.c Image header has bad magic number 2795 39 common/cmd_doc.c Image header has correct magic number 2796 -40 common/cmd_doc.c Error reading Image from DOC device 2797 40 common/cmd_doc.c Image header has correct magic number 2798 41 common/cmd_ide.c before loading a Image from a IDE device 2799 -42 common/cmd_ide.c Bad usage of "ide" command 2800 42 common/cmd_ide.c correct usage of "ide" command 2801 -43 common/cmd_ide.c No boot device 2802 43 common/cmd_ide.c boot device found 2803 -44 common/cmd_ide.c Device not available 2804 44 common/cmd_ide.c Device available 2805 -45 common/cmd_ide.c wrong partition selected 2806 45 common/cmd_ide.c partition selected 2807 -46 common/cmd_ide.c Unknown partition table 2808 46 common/cmd_ide.c valid partition table found 2809 -47 common/cmd_ide.c Invalid partition type 2810 47 common/cmd_ide.c correct partition type 2811 -48 common/cmd_ide.c Error reading Image Header on boot device 2812 48 common/cmd_ide.c reading Image Header from IDE device OK 2813 -49 common/cmd_ide.c Image header has bad magic number 2814 49 common/cmd_ide.c Image header has correct magic number 2815 -50 common/cmd_ide.c Image header has bad checksum 2816 50 common/cmd_ide.c Image header has correct checksum 2817 -51 common/cmd_ide.c Error reading Image from IDE device 2818 51 common/cmd_ide.c reading Image from IDE device OK 2819 52 common/cmd_nand.c before loading a Image from a NAND device 2820 -53 common/cmd_nand.c Bad usage of "nand" command 2821 53 common/cmd_nand.c correct usage of "nand" command 2822 -54 common/cmd_nand.c No boot device 2823 54 common/cmd_nand.c boot device found 2824 -55 common/cmd_nand.c Unknown Chip ID on boot device 2825 55 common/cmd_nand.c correct chip ID found, device available 2826 -56 common/cmd_nand.c Error reading Image Header on boot device 2827 56 common/cmd_nand.c reading Image Header from NAND device OK 2828 -57 common/cmd_nand.c Image header has bad magic number 2829 57 common/cmd_nand.c Image header has correct magic number 2830 -58 common/cmd_nand.c Error reading Image from NAND device 2831 58 common/cmd_nand.c reading Image from NAND device OK 2832 2833 -60 common/env_common.c Environment has a bad CRC, using default 2834 2835 64 net/eth.c starting with Ethernet configuration. 2836 -64 net/eth.c no Ethernet found. 2837 65 net/eth.c Ethernet found. 2838 2839 -80 common/cmd_net.c usage wrong 2840 80 common/cmd_net.c before calling net_loop() 2841 -81 common/cmd_net.c some error in net_loop() occurred 2842 81 common/cmd_net.c net_loop() back without error 2843 -82 common/cmd_net.c size == 0 (File with size 0 loaded) 2844 82 common/cmd_net.c trying automatic boot 2845 83 common/cmd_net.c running "source" command 2846 -83 common/cmd_net.c some error in automatic boot or "source" command 2847 84 common/cmd_net.c end without errors 2848 2849FIT uImage format: 2850 2851 Arg Where When 2852 100 common/cmd_bootm.c Kernel FIT Image has correct format 2853 -100 common/cmd_bootm.c Kernel FIT Image has incorrect format 2854 101 common/cmd_bootm.c No Kernel subimage unit name, using configuration 2855 -101 common/cmd_bootm.c Can't get configuration for kernel subimage 2856 102 common/cmd_bootm.c Kernel unit name specified 2857 -103 common/cmd_bootm.c Can't get kernel subimage node offset 2858 103 common/cmd_bootm.c Found configuration node 2859 104 common/cmd_bootm.c Got kernel subimage node offset 2860 -104 common/cmd_bootm.c Kernel subimage hash verification failed 2861 105 common/cmd_bootm.c Kernel subimage hash verification OK 2862 -105 common/cmd_bootm.c Kernel subimage is for unsupported architecture 2863 106 common/cmd_bootm.c Architecture check OK 2864 -106 common/cmd_bootm.c Kernel subimage has wrong type 2865 107 common/cmd_bootm.c Kernel subimage type OK 2866 -107 common/cmd_bootm.c Can't get kernel subimage data/size 2867 108 common/cmd_bootm.c Got kernel subimage data/size 2868 -108 common/cmd_bootm.c Wrong image type (not legacy, FIT) 2869 -109 common/cmd_bootm.c Can't get kernel subimage type 2870 -110 common/cmd_bootm.c Can't get kernel subimage comp 2871 -111 common/cmd_bootm.c Can't get kernel subimage os 2872 -112 common/cmd_bootm.c Can't get kernel subimage load address 2873 -113 common/cmd_bootm.c Image uncompress/copy overwrite error 2874 2875 120 common/image.c Start initial ramdisk verification 2876 -120 common/image.c Ramdisk FIT image has incorrect format 2877 121 common/image.c Ramdisk FIT image has correct format 2878 122 common/image.c No ramdisk subimage unit name, using configuration 2879 -122 common/image.c Can't get configuration for ramdisk subimage 2880 123 common/image.c Ramdisk unit name specified 2881 -124 common/image.c Can't get ramdisk subimage node offset 2882 125 common/image.c Got ramdisk subimage node offset 2883 -125 common/image.c Ramdisk subimage hash verification failed 2884 126 common/image.c Ramdisk subimage hash verification OK 2885 -126 common/image.c Ramdisk subimage for unsupported architecture 2886 127 common/image.c Architecture check OK 2887 -127 common/image.c Can't get ramdisk subimage data/size 2888 128 common/image.c Got ramdisk subimage data/size 2889 129 common/image.c Can't get ramdisk load address 2890 -129 common/image.c Got ramdisk load address 2891 2892 -130 common/cmd_doc.c Incorrect FIT image format 2893 131 common/cmd_doc.c FIT image format OK 2894 2895 -140 common/cmd_ide.c Incorrect FIT image format 2896 141 common/cmd_ide.c FIT image format OK 2897 2898 -150 common/cmd_nand.c Incorrect FIT image format 2899 151 common/cmd_nand.c FIT image format OK 2900 2901- legacy image format: 2902 CONFIG_IMAGE_FORMAT_LEGACY 2903 enables the legacy image format support in U-Boot. 2904 2905 Default: 2906 enabled if CONFIG_FIT_SIGNATURE is not defined. 2907 2908 CONFIG_DISABLE_IMAGE_LEGACY 2909 disable the legacy image format 2910 2911 This define is introduced, as the legacy image format is 2912 enabled per default for backward compatibility. 2913 2914- Standalone program support: 2915 CONFIG_STANDALONE_LOAD_ADDR 2916 2917 This option defines a board specific value for the 2918 address where standalone program gets loaded, thus 2919 overwriting the architecture dependent default 2920 settings. 2921 2922- Frame Buffer Address: 2923 CONFIG_FB_ADDR 2924 2925 Define CONFIG_FB_ADDR if you want to use specific 2926 address for frame buffer. This is typically the case 2927 when using a graphics controller has separate video 2928 memory. U-Boot will then place the frame buffer at 2929 the given address instead of dynamically reserving it 2930 in system RAM by calling lcd_setmem(), which grabs 2931 the memory for the frame buffer depending on the 2932 configured panel size. 2933 2934 Please see board_init_f function. 2935 2936- Automatic software updates via TFTP server 2937 CONFIG_UPDATE_TFTP 2938 CONFIG_UPDATE_TFTP_CNT_MAX 2939 CONFIG_UPDATE_TFTP_MSEC_MAX 2940 2941 These options enable and control the auto-update feature; 2942 for a more detailed description refer to doc/README.update. 2943 2944- MTD Support (mtdparts command, UBI support) 2945 CONFIG_MTD_DEVICE 2946 2947 Adds the MTD device infrastructure from the Linux kernel. 2948 Needed for mtdparts command support. 2949 2950 CONFIG_MTD_PARTITIONS 2951 2952 Adds the MTD partitioning infrastructure from the Linux 2953 kernel. Needed for UBI support. 2954 2955- UBI support 2956 CONFIG_CMD_UBI 2957 2958 Adds commands for interacting with MTD partitions formatted 2959 with the UBI flash translation layer 2960 2961 Requires also defining CONFIG_RBTREE 2962 2963 CONFIG_UBI_SILENCE_MSG 2964 2965 Make the verbose messages from UBI stop printing. This leaves 2966 warnings and errors enabled. 2967 2968 2969 CONFIG_MTD_UBI_WL_THRESHOLD 2970 This parameter defines the maximum difference between the highest 2971 erase counter value and the lowest erase counter value of eraseblocks 2972 of UBI devices. When this threshold is exceeded, UBI starts performing 2973 wear leveling by means of moving data from eraseblock with low erase 2974 counter to eraseblocks with high erase counter. 2975 2976 The default value should be OK for SLC NAND flashes, NOR flashes and 2977 other flashes which have eraseblock life-cycle 100000 or more. 2978 However, in case of MLC NAND flashes which typically have eraseblock 2979 life-cycle less than 10000, the threshold should be lessened (e.g., 2980 to 128 or 256, although it does not have to be power of 2). 2981 2982 default: 4096 2983 2984 CONFIG_MTD_UBI_BEB_LIMIT 2985 This option specifies the maximum bad physical eraseblocks UBI 2986 expects on the MTD device (per 1024 eraseblocks). If the 2987 underlying flash does not admit of bad eraseblocks (e.g. NOR 2988 flash), this value is ignored. 2989 2990 NAND datasheets often specify the minimum and maximum NVM 2991 (Number of Valid Blocks) for the flashes' endurance lifetime. 2992 The maximum expected bad eraseblocks per 1024 eraseblocks 2993 then can be calculated as "1024 * (1 - MinNVB / MaxNVB)", 2994 which gives 20 for most NANDs (MaxNVB is basically the total 2995 count of eraseblocks on the chip). 2996 2997 To put it differently, if this value is 20, UBI will try to 2998 reserve about 1.9% of physical eraseblocks for bad blocks 2999 handling. And that will be 1.9% of eraseblocks on the entire 3000 NAND chip, not just the MTD partition UBI attaches. This means 3001 that if you have, say, a NAND flash chip admits maximum 40 bad 3002 eraseblocks, and it is split on two MTD partitions of the same 3003 size, UBI will reserve 40 eraseblocks when attaching a 3004 partition. 3005 3006 default: 20 3007 3008 CONFIG_MTD_UBI_FASTMAP 3009 Fastmap is a mechanism which allows attaching an UBI device 3010 in nearly constant time. Instead of scanning the whole MTD device it 3011 only has to locate a checkpoint (called fastmap) on the device. 3012 The on-flash fastmap contains all information needed to attach 3013 the device. Using fastmap makes only sense on large devices where 3014 attaching by scanning takes long. UBI will not automatically install 3015 a fastmap on old images, but you can set the UBI parameter 3016 CONFIG_MTD_UBI_FASTMAP_AUTOCONVERT to 1 if you want so. Please note 3017 that fastmap-enabled images are still usable with UBI implementations 3018 without fastmap support. On typical flash devices the whole fastmap 3019 fits into one PEB. UBI will reserve PEBs to hold two fastmaps. 3020 3021 CONFIG_MTD_UBI_FASTMAP_AUTOCONVERT 3022 Set this parameter to enable fastmap automatically on images 3023 without a fastmap. 3024 default: 0 3025 3026 CONFIG_MTD_UBI_FM_DEBUG 3027 Enable UBI fastmap debug 3028 default: 0 3029 3030- UBIFS support 3031 CONFIG_CMD_UBIFS 3032 3033 Adds commands for interacting with UBI volumes formatted as 3034 UBIFS. UBIFS is read-only in u-boot. 3035 3036 Requires UBI support as well as CONFIG_LZO 3037 3038 CONFIG_UBIFS_SILENCE_MSG 3039 3040 Make the verbose messages from UBIFS stop printing. This leaves 3041 warnings and errors enabled. 3042 3043- SPL framework 3044 CONFIG_SPL 3045 Enable building of SPL globally. 3046 3047 CONFIG_SPL_LDSCRIPT 3048 LDSCRIPT for linking the SPL binary. 3049 3050 CONFIG_SPL_MAX_FOOTPRINT 3051 Maximum size in memory allocated to the SPL, BSS included. 3052 When defined, the linker checks that the actual memory 3053 used by SPL from _start to __bss_end does not exceed it. 3054 CONFIG_SPL_MAX_FOOTPRINT and CONFIG_SPL_BSS_MAX_SIZE 3055 must not be both defined at the same time. 3056 3057 CONFIG_SPL_MAX_SIZE 3058 Maximum size of the SPL image (text, data, rodata, and 3059 linker lists sections), BSS excluded. 3060 When defined, the linker checks that the actual size does 3061 not exceed it. 3062 3063 CONFIG_SPL_TEXT_BASE 3064 TEXT_BASE for linking the SPL binary. 3065 3066 CONFIG_SPL_RELOC_TEXT_BASE 3067 Address to relocate to. If unspecified, this is equal to 3068 CONFIG_SPL_TEXT_BASE (i.e. no relocation is done). 3069 3070 CONFIG_SPL_BSS_START_ADDR 3071 Link address for the BSS within the SPL binary. 3072 3073 CONFIG_SPL_BSS_MAX_SIZE 3074 Maximum size in memory allocated to the SPL BSS. 3075 When defined, the linker checks that the actual memory used 3076 by SPL from __bss_start to __bss_end does not exceed it. 3077 CONFIG_SPL_MAX_FOOTPRINT and CONFIG_SPL_BSS_MAX_SIZE 3078 must not be both defined at the same time. 3079 3080 CONFIG_SPL_STACK 3081 Adress of the start of the stack SPL will use 3082 3083 CONFIG_SPL_PANIC_ON_RAW_IMAGE 3084 When defined, SPL will panic() if the image it has 3085 loaded does not have a signature. 3086 Defining this is useful when code which loads images 3087 in SPL cannot guarantee that absolutely all read errors 3088 will be caught. 3089 An example is the LPC32XX MLC NAND driver, which will 3090 consider that a completely unreadable NAND block is bad, 3091 and thus should be skipped silently. 3092 3093 CONFIG_SPL_RELOC_STACK 3094 Adress of the start of the stack SPL will use after 3095 relocation. If unspecified, this is equal to 3096 CONFIG_SPL_STACK. 3097 3098 CONFIG_SYS_SPL_MALLOC_START 3099 Starting address of the malloc pool used in SPL. 3100 When this option is set the full malloc is used in SPL and 3101 it is set up by spl_init() and before that, the simple malloc() 3102 can be used if CONFIG_SYS_MALLOC_F is defined. 3103 3104 CONFIG_SYS_SPL_MALLOC_SIZE 3105 The size of the malloc pool used in SPL. 3106 3107 CONFIG_SPL_FRAMEWORK 3108 Enable the SPL framework under common/. This framework 3109 supports MMC, NAND and YMODEM loading of U-Boot and NAND 3110 NAND loading of the Linux Kernel. 3111 3112 CONFIG_SPL_OS_BOOT 3113 Enable booting directly to an OS from SPL. 3114 See also: doc/README.falcon 3115 3116 CONFIG_SPL_DISPLAY_PRINT 3117 For ARM, enable an optional function to print more information 3118 about the running system. 3119 3120 CONFIG_SPL_INIT_MINIMAL 3121 Arch init code should be built for a very small image 3122 3123 CONFIG_SYS_MMCSD_RAW_MODE_U_BOOT_PARTITION 3124 Partition on the MMC to load U-Boot from when the MMC is being 3125 used in raw mode 3126 3127 CONFIG_SYS_MMCSD_RAW_MODE_KERNEL_SECTOR 3128 Sector to load kernel uImage from when MMC is being 3129 used in raw mode (for Falcon mode) 3130 3131 CONFIG_SYS_MMCSD_RAW_MODE_ARGS_SECTOR, 3132 CONFIG_SYS_MMCSD_RAW_MODE_ARGS_SECTORS 3133 Sector and number of sectors to load kernel argument 3134 parameters from when MMC is being used in raw mode 3135 (for falcon mode) 3136 3137 CONFIG_SYS_MMCSD_FS_BOOT_PARTITION 3138 Partition on the MMC to load U-Boot from when the MMC is being 3139 used in fs mode 3140 3141 CONFIG_SPL_FS_LOAD_PAYLOAD_NAME 3142 Filename to read to load U-Boot when reading from filesystem 3143 3144 CONFIG_SPL_FS_LOAD_KERNEL_NAME 3145 Filename to read to load kernel uImage when reading 3146 from filesystem (for Falcon mode) 3147 3148 CONFIG_SPL_FS_LOAD_ARGS_NAME 3149 Filename to read to load kernel argument parameters 3150 when reading from filesystem (for Falcon mode) 3151 3152 CONFIG_SPL_MPC83XX_WAIT_FOR_NAND 3153 Set this for NAND SPL on PPC mpc83xx targets, so that 3154 start.S waits for the rest of the SPL to load before 3155 continuing (the hardware starts execution after just 3156 loading the first page rather than the full 4K). 3157 3158 CONFIG_SPL_SKIP_RELOCATE 3159 Avoid SPL relocation 3160 3161 CONFIG_SPL_NAND_BASE 3162 Include nand_base.c in the SPL. Requires 3163 CONFIG_SPL_NAND_DRIVERS. 3164 3165 CONFIG_SPL_NAND_DRIVERS 3166 SPL uses normal NAND drivers, not minimal drivers. 3167 3168 CONFIG_SPL_NAND_ECC 3169 Include standard software ECC in the SPL 3170 3171 CONFIG_SPL_NAND_SIMPLE 3172 Support for NAND boot using simple NAND drivers that 3173 expose the cmd_ctrl() interface. 3174 3175 CONFIG_SPL_UBI 3176 Support for a lightweight UBI (fastmap) scanner and 3177 loader 3178 3179 CONFIG_SPL_NAND_RAW_ONLY 3180 Support to boot only raw u-boot.bin images. Use this only 3181 if you need to save space. 3182 3183 CONFIG_SPL_COMMON_INIT_DDR 3184 Set for common ddr init with serial presence detect in 3185 SPL binary. 3186 3187 CONFIG_SYS_NAND_5_ADDR_CYCLE, CONFIG_SYS_NAND_PAGE_COUNT, 3188 CONFIG_SYS_NAND_PAGE_SIZE, CONFIG_SYS_NAND_OOBSIZE, 3189 CONFIG_SYS_NAND_BLOCK_SIZE, CONFIG_SYS_NAND_BAD_BLOCK_POS, 3190 CONFIG_SYS_NAND_ECCPOS, CONFIG_SYS_NAND_ECCSIZE, 3191 CONFIG_SYS_NAND_ECCBYTES 3192 Defines the size and behavior of the NAND that SPL uses 3193 to read U-Boot 3194 3195 CONFIG_SPL_NAND_BOOT 3196 Add support NAND boot 3197 3198 CONFIG_SYS_NAND_U_BOOT_OFFS 3199 Location in NAND to read U-Boot from 3200 3201 CONFIG_SYS_NAND_U_BOOT_DST 3202 Location in memory to load U-Boot to 3203 3204 CONFIG_SYS_NAND_U_BOOT_SIZE 3205 Size of image to load 3206 3207 CONFIG_SYS_NAND_U_BOOT_START 3208 Entry point in loaded image to jump to 3209 3210 CONFIG_SYS_NAND_HW_ECC_OOBFIRST 3211 Define this if you need to first read the OOB and then the 3212 data. This is used, for example, on davinci platforms. 3213 3214 CONFIG_SPL_OMAP3_ID_NAND 3215 Support for an OMAP3-specific set of functions to return the 3216 ID and MFR of the first attached NAND chip, if present. 3217 3218 CONFIG_SPL_RAM_DEVICE 3219 Support for running image already present in ram, in SPL binary 3220 3221 CONFIG_SPL_PAD_TO 3222 Image offset to which the SPL should be padded before appending 3223 the SPL payload. By default, this is defined as 3224 CONFIG_SPL_MAX_SIZE, or 0 if CONFIG_SPL_MAX_SIZE is undefined. 3225 CONFIG_SPL_PAD_TO must be either 0, meaning to append the SPL 3226 payload without any padding, or >= CONFIG_SPL_MAX_SIZE. 3227 3228 CONFIG_SPL_TARGET 3229 Final target image containing SPL and payload. Some SPLs 3230 use an arch-specific makefile fragment instead, for 3231 example if more than one image needs to be produced. 3232 3233 CONFIG_FIT_SPL_PRINT 3234 Printing information about a FIT image adds quite a bit of 3235 code to SPL. So this is normally disabled in SPL. Use this 3236 option to re-enable it. This will affect the output of the 3237 bootm command when booting a FIT image. 3238 3239- TPL framework 3240 CONFIG_TPL 3241 Enable building of TPL globally. 3242 3243 CONFIG_TPL_PAD_TO 3244 Image offset to which the TPL should be padded before appending 3245 the TPL payload. By default, this is defined as 3246 CONFIG_SPL_MAX_SIZE, or 0 if CONFIG_SPL_MAX_SIZE is undefined. 3247 CONFIG_SPL_PAD_TO must be either 0, meaning to append the SPL 3248 payload without any padding, or >= CONFIG_SPL_MAX_SIZE. 3249 3250- Interrupt support (PPC): 3251 3252 There are common interrupt_init() and timer_interrupt() 3253 for all PPC archs. interrupt_init() calls interrupt_init_cpu() 3254 for CPU specific initialization. interrupt_init_cpu() 3255 should set decrementer_count to appropriate value. If 3256 CPU resets decrementer automatically after interrupt 3257 (ppc4xx) it should set decrementer_count to zero. 3258 timer_interrupt() calls timer_interrupt_cpu() for CPU 3259 specific handling. If board has watchdog / status_led 3260 / other_activity_monitor it works automatically from 3261 general timer_interrupt(). 3262 3263 3264Board initialization settings: 3265------------------------------ 3266 3267During Initialization u-boot calls a number of board specific functions 3268to allow the preparation of board specific prerequisites, e.g. pin setup 3269before drivers are initialized. To enable these callbacks the 3270following configuration macros have to be defined. Currently this is 3271architecture specific, so please check arch/your_architecture/lib/board.c 3272typically in board_init_f() and board_init_r(). 3273 3274- CONFIG_BOARD_EARLY_INIT_F: Call board_early_init_f() 3275- CONFIG_BOARD_EARLY_INIT_R: Call board_early_init_r() 3276- CONFIG_BOARD_LATE_INIT: Call board_late_init() 3277- CONFIG_BOARD_POSTCLK_INIT: Call board_postclk_init() 3278 3279Configuration Settings: 3280----------------------- 3281 3282- CONFIG_SYS_SUPPORT_64BIT_DATA: Defined automatically if compiled as 64-bit. 3283 Optionally it can be defined to support 64-bit memory commands. 3284 3285- CONFIG_SYS_LONGHELP: Defined when you want long help messages included; 3286 undefine this when you're short of memory. 3287 3288- CONFIG_SYS_HELP_CMD_WIDTH: Defined when you want to override the default 3289 width of the commands listed in the 'help' command output. 3290 3291- CONFIG_SYS_PROMPT: This is what U-Boot prints on the console to 3292 prompt for user input. 3293 3294- CONFIG_SYS_CBSIZE: Buffer size for input from the Console 3295 3296- CONFIG_SYS_PBSIZE: Buffer size for Console output 3297 3298- CONFIG_SYS_MAXARGS: max. Number of arguments accepted for monitor commands 3299 3300- CONFIG_SYS_BARGSIZE: Buffer size for Boot Arguments which are passed to 3301 the application (usually a Linux kernel) when it is 3302 booted 3303 3304- CONFIG_SYS_BAUDRATE_TABLE: 3305 List of legal baudrate settings for this board. 3306 3307- CONFIG_SYS_MEMTEST_START, CONFIG_SYS_MEMTEST_END: 3308 Begin and End addresses of the area used by the 3309 simple memory test. 3310 3311- CONFIG_SYS_ALT_MEMTEST: 3312 Enable an alternate, more extensive memory test. 3313 3314- CONFIG_SYS_MEMTEST_SCRATCH: 3315 Scratch address used by the alternate memory test 3316 You only need to set this if address zero isn't writeable 3317 3318- CONFIG_SYS_MEM_RESERVE_SECURE 3319 Only implemented for ARMv8 for now. 3320 If defined, the size of CONFIG_SYS_MEM_RESERVE_SECURE memory 3321 is substracted from total RAM and won't be reported to OS. 3322 This memory can be used as secure memory. A variable 3323 gd->arch.secure_ram is used to track the location. In systems 3324 the RAM base is not zero, or RAM is divided into banks, 3325 this variable needs to be recalcuated to get the address. 3326 3327- CONFIG_SYS_MEM_TOP_HIDE: 3328 If CONFIG_SYS_MEM_TOP_HIDE is defined in the board config header, 3329 this specified memory area will get subtracted from the top 3330 (end) of RAM and won't get "touched" at all by U-Boot. By 3331 fixing up gd->ram_size the Linux kernel should gets passed 3332 the now "corrected" memory size and won't touch it either. 3333 This should work for arch/ppc and arch/powerpc. Only Linux 3334 board ports in arch/powerpc with bootwrapper support that 3335 recalculate the memory size from the SDRAM controller setup 3336 will have to get fixed in Linux additionally. 3337 3338 This option can be used as a workaround for the 440EPx/GRx 3339 CHIP 11 errata where the last 256 bytes in SDRAM shouldn't 3340 be touched. 3341 3342 WARNING: Please make sure that this value is a multiple of 3343 the Linux page size (normally 4k). If this is not the case, 3344 then the end address of the Linux memory will be located at a 3345 non page size aligned address and this could cause major 3346 problems. 3347 3348- CONFIG_SYS_LOADS_BAUD_CHANGE: 3349 Enable temporary baudrate change while serial download 3350 3351- CONFIG_SYS_SDRAM_BASE: 3352 Physical start address of SDRAM. _Must_ be 0 here. 3353 3354- CONFIG_SYS_FLASH_BASE: 3355 Physical start address of Flash memory. 3356 3357- CONFIG_SYS_MONITOR_BASE: 3358 Physical start address of boot monitor code (set by 3359 make config files to be same as the text base address 3360 (CONFIG_SYS_TEXT_BASE) used when linking) - same as 3361 CONFIG_SYS_FLASH_BASE when booting from flash. 3362 3363- CONFIG_SYS_MONITOR_LEN: 3364 Size of memory reserved for monitor code, used to 3365 determine _at_compile_time_ (!) if the environment is 3366 embedded within the U-Boot image, or in a separate 3367 flash sector. 3368 3369- CONFIG_SYS_MALLOC_LEN: 3370 Size of DRAM reserved for malloc() use. 3371 3372- CONFIG_SYS_MALLOC_F_LEN 3373 Size of the malloc() pool for use before relocation. If 3374 this is defined, then a very simple malloc() implementation 3375 will become available before relocation. The address is just 3376 below the global data, and the stack is moved down to make 3377 space. 3378 3379 This feature allocates regions with increasing addresses 3380 within the region. calloc() is supported, but realloc() 3381 is not available. free() is supported but does nothing. 3382 The memory will be freed (or in fact just forgotten) when 3383 U-Boot relocates itself. 3384 3385- CONFIG_SYS_MALLOC_SIMPLE 3386 Provides a simple and small malloc() and calloc() for those 3387 boards which do not use the full malloc in SPL (which is 3388 enabled with CONFIG_SYS_SPL_MALLOC_START). 3389 3390- CONFIG_SYS_NONCACHED_MEMORY: 3391 Size of non-cached memory area. This area of memory will be 3392 typically located right below the malloc() area and mapped 3393 uncached in the MMU. This is useful for drivers that would 3394 otherwise require a lot of explicit cache maintenance. For 3395 some drivers it's also impossible to properly maintain the 3396 cache. For example if the regions that need to be flushed 3397 are not a multiple of the cache-line size, *and* padding 3398 cannot be allocated between the regions to align them (i.e. 3399 if the HW requires a contiguous array of regions, and the 3400 size of each region is not cache-aligned), then a flush of 3401 one region may result in overwriting data that hardware has 3402 written to another region in the same cache-line. This can 3403 happen for example in network drivers where descriptors for 3404 buffers are typically smaller than the CPU cache-line (e.g. 3405 16 bytes vs. 32 or 64 bytes). 3406 3407 Non-cached memory is only supported on 32-bit ARM at present. 3408 3409- CONFIG_SYS_BOOTM_LEN: 3410 Normally compressed uImages are limited to an 3411 uncompressed size of 8 MBytes. If this is not enough, 3412 you can define CONFIG_SYS_BOOTM_LEN in your board config file 3413 to adjust this setting to your needs. 3414 3415- CONFIG_SYS_BOOTMAPSZ: 3416 Maximum size of memory mapped by the startup code of 3417 the Linux kernel; all data that must be processed by 3418 the Linux kernel (bd_info, boot arguments, FDT blob if 3419 used) must be put below this limit, unless "bootm_low" 3420 environment variable is defined and non-zero. In such case 3421 all data for the Linux kernel must be between "bootm_low" 3422 and "bootm_low" + CONFIG_SYS_BOOTMAPSZ. The environment 3423 variable "bootm_mapsize" will override the value of 3424 CONFIG_SYS_BOOTMAPSZ. If CONFIG_SYS_BOOTMAPSZ is undefined, 3425 then the value in "bootm_size" will be used instead. 3426 3427- CONFIG_SYS_BOOT_RAMDISK_HIGH: 3428 Enable initrd_high functionality. If defined then the 3429 initrd_high feature is enabled and the bootm ramdisk subcommand 3430 is enabled. 3431 3432- CONFIG_SYS_BOOT_GET_CMDLINE: 3433 Enables allocating and saving kernel cmdline in space between 3434 "bootm_low" and "bootm_low" + BOOTMAPSZ. 3435 3436- CONFIG_SYS_BOOT_GET_KBD: 3437 Enables allocating and saving a kernel copy of the bd_info in 3438 space between "bootm_low" and "bootm_low" + BOOTMAPSZ. 3439 3440- CONFIG_SYS_MAX_FLASH_BANKS: 3441 Max number of Flash memory banks 3442 3443- CONFIG_SYS_MAX_FLASH_SECT: 3444 Max number of sectors on a Flash chip 3445 3446- CONFIG_SYS_FLASH_ERASE_TOUT: 3447 Timeout for Flash erase operations (in ms) 3448 3449- CONFIG_SYS_FLASH_WRITE_TOUT: 3450 Timeout for Flash write operations (in ms) 3451 3452- CONFIG_SYS_FLASH_LOCK_TOUT 3453 Timeout for Flash set sector lock bit operation (in ms) 3454 3455- CONFIG_SYS_FLASH_UNLOCK_TOUT 3456 Timeout for Flash clear lock bits operation (in ms) 3457 3458- CONFIG_SYS_FLASH_PROTECTION 3459 If defined, hardware flash sectors protection is used 3460 instead of U-Boot software protection. 3461 3462- CONFIG_SYS_DIRECT_FLASH_TFTP: 3463 3464 Enable TFTP transfers directly to flash memory; 3465 without this option such a download has to be 3466 performed in two steps: (1) download to RAM, and (2) 3467 copy from RAM to flash. 3468 3469 The two-step approach is usually more reliable, since 3470 you can check if the download worked before you erase 3471 the flash, but in some situations (when system RAM is 3472 too limited to allow for a temporary copy of the 3473 downloaded image) this option may be very useful. 3474 3475- CONFIG_SYS_FLASH_CFI: 3476 Define if the flash driver uses extra elements in the 3477 common flash structure for storing flash geometry. 3478 3479- CONFIG_FLASH_CFI_DRIVER 3480 This option also enables the building of the cfi_flash driver 3481 in the drivers directory 3482 3483- CONFIG_FLASH_CFI_MTD 3484 This option enables the building of the cfi_mtd driver 3485 in the drivers directory. The driver exports CFI flash 3486 to the MTD layer. 3487 3488- CONFIG_SYS_FLASH_USE_BUFFER_WRITE 3489 Use buffered writes to flash. 3490 3491- CONFIG_FLASH_SPANSION_S29WS_N 3492 s29ws-n MirrorBit flash has non-standard addresses for buffered 3493 write commands. 3494 3495- CONFIG_SYS_FLASH_QUIET_TEST 3496 If this option is defined, the common CFI flash doesn't 3497 print it's warning upon not recognized FLASH banks. This 3498 is useful, if some of the configured banks are only 3499 optionally available. 3500 3501- CONFIG_FLASH_SHOW_PROGRESS 3502 If defined (must be an integer), print out countdown 3503 digits and dots. Recommended value: 45 (9..1) for 80 3504 column displays, 15 (3..1) for 40 column displays. 3505 3506- CONFIG_FLASH_VERIFY 3507 If defined, the content of the flash (destination) is compared 3508 against the source after the write operation. An error message 3509 will be printed when the contents are not identical. 3510 Please note that this option is useless in nearly all cases, 3511 since such flash programming errors usually are detected earlier 3512 while unprotecting/erasing/programming. Please only enable 3513 this option if you really know what you are doing. 3514 3515- CONFIG_SYS_RX_ETH_BUFFER: 3516 Defines the number of Ethernet receive buffers. On some 3517 Ethernet controllers it is recommended to set this value 3518 to 8 or even higher (EEPRO100 or 405 EMAC), since all 3519 buffers can be full shortly after enabling the interface 3520 on high Ethernet traffic. 3521 Defaults to 4 if not defined. 3522 3523- CONFIG_ENV_MAX_ENTRIES 3524 3525 Maximum number of entries in the hash table that is used 3526 internally to store the environment settings. The default 3527 setting is supposed to be generous and should work in most 3528 cases. This setting can be used to tune behaviour; see 3529 lib/hashtable.c for details. 3530 3531- CONFIG_ENV_FLAGS_LIST_DEFAULT 3532- CONFIG_ENV_FLAGS_LIST_STATIC 3533 Enable validation of the values given to environment variables when 3534 calling env set. Variables can be restricted to only decimal, 3535 hexadecimal, or boolean. If CONFIG_CMD_NET is also defined, 3536 the variables can also be restricted to IP address or MAC address. 3537 3538 The format of the list is: 3539 type_attribute = [s|d|x|b|i|m] 3540 access_attribute = [a|r|o|c] 3541 attributes = type_attribute[access_attribute] 3542 entry = variable_name[:attributes] 3543 list = entry[,list] 3544 3545 The type attributes are: 3546 s - String (default) 3547 d - Decimal 3548 x - Hexadecimal 3549 b - Boolean ([1yYtT|0nNfF]) 3550 i - IP address 3551 m - MAC address 3552 3553 The access attributes are: 3554 a - Any (default) 3555 r - Read-only 3556 o - Write-once 3557 c - Change-default 3558 3559 - CONFIG_ENV_FLAGS_LIST_DEFAULT 3560 Define this to a list (string) to define the ".flags" 3561 environment variable in the default or embedded environment. 3562 3563 - CONFIG_ENV_FLAGS_LIST_STATIC 3564 Define this to a list (string) to define validation that 3565 should be done if an entry is not found in the ".flags" 3566 environment variable. To override a setting in the static 3567 list, simply add an entry for the same variable name to the 3568 ".flags" variable. 3569 3570 If CONFIG_REGEX is defined, the variable_name above is evaluated as a 3571 regular expression. This allows multiple variables to define the same 3572 flags without explicitly listing them for each variable. 3573 3574- CONFIG_ENV_ACCESS_IGNORE_FORCE 3575 If defined, don't allow the -f switch to env set override variable 3576 access flags. 3577 3578- CONFIG_USE_STDINT 3579 If stdint.h is available with your toolchain you can define this 3580 option to enable it. You can provide option 'USE_STDINT=1' when 3581 building U-Boot to enable this. 3582 3583The following definitions that deal with the placement and management 3584of environment data (variable area); in general, we support the 3585following configurations: 3586 3587- CONFIG_BUILD_ENVCRC: 3588 3589 Builds up envcrc with the target environment so that external utils 3590 may easily extract it and embed it in final U-Boot images. 3591 3592- CONFIG_ENV_IS_IN_FLASH: 3593 3594 Define this if the environment is in flash memory. 3595 3596 a) The environment occupies one whole flash sector, which is 3597 "embedded" in the text segment with the U-Boot code. This 3598 happens usually with "bottom boot sector" or "top boot 3599 sector" type flash chips, which have several smaller 3600 sectors at the start or the end. For instance, such a 3601 layout can have sector sizes of 8, 2x4, 16, Nx32 kB. In 3602 such a case you would place the environment in one of the 3603 4 kB sectors - with U-Boot code before and after it. With 3604 "top boot sector" type flash chips, you would put the 3605 environment in one of the last sectors, leaving a gap 3606 between U-Boot and the environment. 3607 3608 - CONFIG_ENV_OFFSET: 3609 3610 Offset of environment data (variable area) to the 3611 beginning of flash memory; for instance, with bottom boot 3612 type flash chips the second sector can be used: the offset 3613 for this sector is given here. 3614 3615 CONFIG_ENV_OFFSET is used relative to CONFIG_SYS_FLASH_BASE. 3616 3617 - CONFIG_ENV_ADDR: 3618 3619 This is just another way to specify the start address of 3620 the flash sector containing the environment (instead of 3621 CONFIG_ENV_OFFSET). 3622 3623 - CONFIG_ENV_SECT_SIZE: 3624 3625 Size of the sector containing the environment. 3626 3627 3628 b) Sometimes flash chips have few, equal sized, BIG sectors. 3629 In such a case you don't want to spend a whole sector for 3630 the environment. 3631 3632 - CONFIG_ENV_SIZE: 3633 3634 If you use this in combination with CONFIG_ENV_IS_IN_FLASH 3635 and CONFIG_ENV_SECT_SIZE, you can specify to use only a part 3636 of this flash sector for the environment. This saves 3637 memory for the RAM copy of the environment. 3638 3639 It may also save flash memory if you decide to use this 3640 when your environment is "embedded" within U-Boot code, 3641 since then the remainder of the flash sector could be used 3642 for U-Boot code. It should be pointed out that this is 3643 STRONGLY DISCOURAGED from a robustness point of view: 3644 updating the environment in flash makes it always 3645 necessary to erase the WHOLE sector. If something goes 3646 wrong before the contents has been restored from a copy in 3647 RAM, your target system will be dead. 3648 3649 - CONFIG_ENV_ADDR_REDUND 3650 CONFIG_ENV_SIZE_REDUND 3651 3652 These settings describe a second storage area used to hold 3653 a redundant copy of the environment data, so that there is 3654 a valid backup copy in case there is a power failure during 3655 a "saveenv" operation. 3656 3657BE CAREFUL! Any changes to the flash layout, and some changes to the 3658source code will make it necessary to adapt <board>/u-boot.lds* 3659accordingly! 3660 3661 3662- CONFIG_ENV_IS_IN_NVRAM: 3663 3664 Define this if you have some non-volatile memory device 3665 (NVRAM, battery buffered SRAM) which you want to use for the 3666 environment. 3667 3668 - CONFIG_ENV_ADDR: 3669 - CONFIG_ENV_SIZE: 3670 3671 These two #defines are used to determine the memory area you 3672 want to use for environment. It is assumed that this memory 3673 can just be read and written to, without any special 3674 provision. 3675 3676BE CAREFUL! The first access to the environment happens quite early 3677in U-Boot initialization (when we try to get the setting of for the 3678console baudrate). You *MUST* have mapped your NVRAM area then, or 3679U-Boot will hang. 3680 3681Please note that even with NVRAM we still use a copy of the 3682environment in RAM: we could work on NVRAM directly, but we want to 3683keep settings there always unmodified except somebody uses "saveenv" 3684to save the current settings. 3685 3686 3687- CONFIG_ENV_IS_IN_EEPROM: 3688 3689 Use this if you have an EEPROM or similar serial access 3690 device and a driver for it. 3691 3692 - CONFIG_ENV_OFFSET: 3693 - CONFIG_ENV_SIZE: 3694 3695 These two #defines specify the offset and size of the 3696 environment area within the total memory of your EEPROM. 3697 3698 - CONFIG_SYS_I2C_EEPROM_ADDR: 3699 If defined, specified the chip address of the EEPROM device. 3700 The default address is zero. 3701 3702 - CONFIG_SYS_I2C_EEPROM_BUS: 3703 If defined, specified the i2c bus of the EEPROM device. 3704 3705 - CONFIG_SYS_EEPROM_PAGE_WRITE_BITS: 3706 If defined, the number of bits used to address bytes in a 3707 single page in the EEPROM device. A 64 byte page, for example 3708 would require six bits. 3709 3710 - CONFIG_SYS_EEPROM_PAGE_WRITE_DELAY_MS: 3711 If defined, the number of milliseconds to delay between 3712 page writes. The default is zero milliseconds. 3713 3714 - CONFIG_SYS_I2C_EEPROM_ADDR_LEN: 3715 The length in bytes of the EEPROM memory array address. Note 3716 that this is NOT the chip address length! 3717 3718 - CONFIG_SYS_I2C_EEPROM_ADDR_OVERFLOW: 3719 EEPROM chips that implement "address overflow" are ones 3720 like Catalyst 24WC04/08/16 which has 9/10/11 bits of 3721 address and the extra bits end up in the "chip address" bit 3722 slots. This makes a 24WC08 (1Kbyte) chip look like four 256 3723 byte chips. 3724 3725 Note that we consider the length of the address field to 3726 still be one byte because the extra address bits are hidden 3727 in the chip address. 3728 3729 - CONFIG_SYS_EEPROM_SIZE: 3730 The size in bytes of the EEPROM device. 3731 3732 - CONFIG_ENV_EEPROM_IS_ON_I2C 3733 define this, if you have I2C and SPI activated, and your 3734 EEPROM, which holds the environment, is on the I2C bus. 3735 3736 - CONFIG_I2C_ENV_EEPROM_BUS 3737 if you have an Environment on an EEPROM reached over 3738 I2C muxes, you can define here, how to reach this 3739 EEPROM. For example: 3740 3741 #define CONFIG_I2C_ENV_EEPROM_BUS 1 3742 3743 EEPROM which holds the environment, is reached over 3744 a pca9547 i2c mux with address 0x70, channel 3. 3745 3746- CONFIG_ENV_IS_IN_DATAFLASH: 3747 3748 Define this if you have a DataFlash memory device which you 3749 want to use for the environment. 3750 3751 - CONFIG_ENV_OFFSET: 3752 - CONFIG_ENV_ADDR: 3753 - CONFIG_ENV_SIZE: 3754 3755 These three #defines specify the offset and size of the 3756 environment area within the total memory of your DataFlash placed 3757 at the specified address. 3758 3759- CONFIG_ENV_IS_IN_SPI_FLASH: 3760 3761 Define this if you have a SPI Flash memory device which you 3762 want to use for the environment. 3763 3764 - CONFIG_ENV_OFFSET: 3765 - CONFIG_ENV_SIZE: 3766 3767 These two #defines specify the offset and size of the 3768 environment area within the SPI Flash. CONFIG_ENV_OFFSET must be 3769 aligned to an erase sector boundary. 3770 3771 - CONFIG_ENV_SECT_SIZE: 3772 3773 Define the SPI flash's sector size. 3774 3775 - CONFIG_ENV_OFFSET_REDUND (optional): 3776 3777 This setting describes a second storage area of CONFIG_ENV_SIZE 3778 size used to hold a redundant copy of the environment data, so 3779 that there is a valid backup copy in case there is a power failure 3780 during a "saveenv" operation. CONFIG_ENV_OFFSET_REDUND must be 3781 aligned to an erase sector boundary. 3782 3783 - CONFIG_ENV_SPI_BUS (optional): 3784 - CONFIG_ENV_SPI_CS (optional): 3785 3786 Define the SPI bus and chip select. If not defined they will be 0. 3787 3788 - CONFIG_ENV_SPI_MAX_HZ (optional): 3789 3790 Define the SPI max work clock. If not defined then use 1MHz. 3791 3792 - CONFIG_ENV_SPI_MODE (optional): 3793 3794 Define the SPI work mode. If not defined then use SPI_MODE_3. 3795 3796- CONFIG_ENV_IS_IN_REMOTE: 3797 3798 Define this if you have a remote memory space which you 3799 want to use for the local device's environment. 3800 3801 - CONFIG_ENV_ADDR: 3802 - CONFIG_ENV_SIZE: 3803 3804 These two #defines specify the address and size of the 3805 environment area within the remote memory space. The 3806 local device can get the environment from remote memory 3807 space by SRIO or PCIE links. 3808 3809BE CAREFUL! For some special cases, the local device can not use 3810"saveenv" command. For example, the local device will get the 3811environment stored in a remote NOR flash by SRIO or PCIE link, 3812but it can not erase, write this NOR flash by SRIO or PCIE interface. 3813 3814- CONFIG_ENV_IS_IN_NAND: 3815 3816 Define this if you have a NAND device which you want to use 3817 for the environment. 3818 3819 - CONFIG_ENV_OFFSET: 3820 - CONFIG_ENV_SIZE: 3821 3822 These two #defines specify the offset and size of the environment 3823 area within the first NAND device. CONFIG_ENV_OFFSET must be 3824 aligned to an erase block boundary. 3825 3826 - CONFIG_ENV_OFFSET_REDUND (optional): 3827 3828 This setting describes a second storage area of CONFIG_ENV_SIZE 3829 size used to hold a redundant copy of the environment data, so 3830 that there is a valid backup copy in case there is a power failure 3831 during a "saveenv" operation. CONFIG_ENV_OFFSET_REDUND must be 3832 aligned to an erase block boundary. 3833 3834 - CONFIG_ENV_RANGE (optional): 3835 3836 Specifies the length of the region in which the environment 3837 can be written. This should be a multiple of the NAND device's 3838 block size. Specifying a range with more erase blocks than 3839 are needed to hold CONFIG_ENV_SIZE allows bad blocks within 3840 the range to be avoided. 3841 3842 - CONFIG_ENV_OFFSET_OOB (optional): 3843 3844 Enables support for dynamically retrieving the offset of the 3845 environment from block zero's out-of-band data. The 3846 "nand env.oob" command can be used to record this offset. 3847 Currently, CONFIG_ENV_OFFSET_REDUND is not supported when 3848 using CONFIG_ENV_OFFSET_OOB. 3849 3850- CONFIG_NAND_ENV_DST 3851 3852 Defines address in RAM to which the nand_spl code should copy the 3853 environment. If redundant environment is used, it will be copied to 3854 CONFIG_NAND_ENV_DST + CONFIG_ENV_SIZE. 3855 3856- CONFIG_ENV_IS_IN_UBI: 3857 3858 Define this if you have an UBI volume that you want to use for the 3859 environment. This has the benefit of wear-leveling the environment 3860 accesses, which is important on NAND. 3861 3862 - CONFIG_ENV_UBI_PART: 3863 3864 Define this to a string that is the mtd partition containing the UBI. 3865 3866 - CONFIG_ENV_UBI_VOLUME: 3867 3868 Define this to the name of the volume that you want to store the 3869 environment in. 3870 3871 - CONFIG_ENV_UBI_VOLUME_REDUND: 3872 3873 Define this to the name of another volume to store a second copy of 3874 the environment in. This will enable redundant environments in UBI. 3875 It is assumed that both volumes are in the same MTD partition. 3876 3877 - CONFIG_UBI_SILENCE_MSG 3878 - CONFIG_UBIFS_SILENCE_MSG 3879 3880 You will probably want to define these to avoid a really noisy system 3881 when storing the env in UBI. 3882 3883- CONFIG_ENV_IS_IN_FAT: 3884 Define this if you want to use the FAT file system for the environment. 3885 3886 - FAT_ENV_INTERFACE: 3887 3888 Define this to a string that is the name of the block device. 3889 3890 - FAT_ENV_DEVICE_AND_PART: 3891 3892 Define this to a string to specify the partition of the device. It can 3893 be as following: 3894 3895 "D:P", "D:0", "D", "D:" or "D:auto" (D, P are integers. And P >= 1) 3896 - "D:P": device D partition P. Error occurs if device D has no 3897 partition table. 3898 - "D:0": device D. 3899 - "D" or "D:": device D partition 1 if device D has partition 3900 table, or the whole device D if has no partition 3901 table. 3902 - "D:auto": first partition in device D with bootable flag set. 3903 If none, first valid partition in device D. If no 3904 partition table then means device D. 3905 3906 - FAT_ENV_FILE: 3907 3908 It's a string of the FAT file name. This file use to store the 3909 environment. 3910 3911 - CONFIG_FAT_WRITE: 3912 This should be defined. Otherwise it cannot save the environment file. 3913 3914- CONFIG_ENV_IS_IN_MMC: 3915 3916 Define this if you have an MMC device which you want to use for the 3917 environment. 3918 3919 - CONFIG_SYS_MMC_ENV_DEV: 3920 3921 Specifies which MMC device the environment is stored in. 3922 3923 - CONFIG_SYS_MMC_ENV_PART (optional): 3924 3925 Specifies which MMC partition the environment is stored in. If not 3926 set, defaults to partition 0, the user area. Common values might be 3927 1 (first MMC boot partition), 2 (second MMC boot partition). 3928 3929 - CONFIG_ENV_OFFSET: 3930 - CONFIG_ENV_SIZE: 3931 3932 These two #defines specify the offset and size of the environment 3933 area within the specified MMC device. 3934 3935 If offset is positive (the usual case), it is treated as relative to 3936 the start of the MMC partition. If offset is negative, it is treated 3937 as relative to the end of the MMC partition. This can be useful if 3938 your board may be fitted with different MMC devices, which have 3939 different sizes for the MMC partitions, and you always want the 3940 environment placed at the very end of the partition, to leave the 3941 maximum possible space before it, to store other data. 3942 3943 These two values are in units of bytes, but must be aligned to an 3944 MMC sector boundary. 3945 3946 - CONFIG_ENV_OFFSET_REDUND (optional): 3947 3948 Specifies a second storage area, of CONFIG_ENV_SIZE size, used to 3949 hold a redundant copy of the environment data. This provides a 3950 valid backup copy in case the other copy is corrupted, e.g. due 3951 to a power failure during a "saveenv" operation. 3952 3953 This value may also be positive or negative; this is handled in the 3954 same way as CONFIG_ENV_OFFSET. 3955 3956 This value is also in units of bytes, but must also be aligned to 3957 an MMC sector boundary. 3958 3959 - CONFIG_ENV_SIZE_REDUND (optional): 3960 3961 This value need not be set, even when CONFIG_ENV_OFFSET_REDUND is 3962 set. If this value is set, it must be set to the same value as 3963 CONFIG_ENV_SIZE. 3964 3965- CONFIG_SYS_SPI_INIT_OFFSET 3966 3967 Defines offset to the initial SPI buffer area in DPRAM. The 3968 area is used at an early stage (ROM part) if the environment 3969 is configured to reside in the SPI EEPROM: We need a 520 byte 3970 scratch DPRAM area. It is used between the two initialization 3971 calls (spi_init_f() and spi_init_r()). A value of 0xB00 seems 3972 to be a good choice since it makes it far enough from the 3973 start of the data area as well as from the stack pointer. 3974 3975Please note that the environment is read-only until the monitor 3976has been relocated to RAM and a RAM copy of the environment has been 3977created; also, when using EEPROM you will have to use getenv_f() 3978until then to read environment variables. 3979 3980The environment is protected by a CRC32 checksum. Before the monitor 3981is relocated into RAM, as a result of a bad CRC you will be working 3982with the compiled-in default environment - *silently*!!! [This is 3983necessary, because the first environment variable we need is the 3984"baudrate" setting for the console - if we have a bad CRC, we don't 3985have any device yet where we could complain.] 3986 3987Note: once the monitor has been relocated, then it will complain if 3988the default environment is used; a new CRC is computed as soon as you 3989use the "saveenv" command to store a valid environment. 3990 3991- CONFIG_SYS_FAULT_ECHO_LINK_DOWN: 3992 Echo the inverted Ethernet link state to the fault LED. 3993 3994 Note: If this option is active, then CONFIG_SYS_FAULT_MII_ADDR 3995 also needs to be defined. 3996 3997- CONFIG_SYS_FAULT_MII_ADDR: 3998 MII address of the PHY to check for the Ethernet link state. 3999 4000- CONFIG_NS16550_MIN_FUNCTIONS: 4001 Define this if you desire to only have use of the NS16550_init 4002 and NS16550_putc functions for the serial driver located at 4003 drivers/serial/ns16550.c. This option is useful for saving 4004 space for already greatly restricted images, including but not 4005 limited to NAND_SPL configurations. 4006 4007- CONFIG_DISPLAY_BOARDINFO 4008 Display information about the board that U-Boot is running on 4009 when U-Boot starts up. The board function checkboard() is called 4010 to do this. 4011 4012- CONFIG_DISPLAY_BOARDINFO_LATE 4013 Similar to the previous option, but display this information 4014 later, once stdio is running and output goes to the LCD, if 4015 present. 4016 4017- CONFIG_BOARD_SIZE_LIMIT: 4018 Maximum size of the U-Boot image. When defined, the 4019 build system checks that the actual size does not 4020 exceed it. 4021 4022Low Level (hardware related) configuration options: 4023--------------------------------------------------- 4024 4025- CONFIG_SYS_CACHELINE_SIZE: 4026 Cache Line Size of the CPU. 4027 4028- CONFIG_SYS_DEFAULT_IMMR: 4029 Default address of the IMMR after system reset. 4030 4031 Needed on some 8260 systems (MPC8260ADS, PQ2FADS-ZU, 4032 and RPXsuper) to be able to adjust the position of 4033 the IMMR register after a reset. 4034 4035- CONFIG_SYS_CCSRBAR_DEFAULT: 4036 Default (power-on reset) physical address of CCSR on Freescale 4037 PowerPC SOCs. 4038 4039- CONFIG_SYS_CCSRBAR: 4040 Virtual address of CCSR. On a 32-bit build, this is typically 4041 the same value as CONFIG_SYS_CCSRBAR_DEFAULT. 4042 4043 CONFIG_SYS_DEFAULT_IMMR must also be set to this value, 4044 for cross-platform code that uses that macro instead. 4045 4046- CONFIG_SYS_CCSRBAR_PHYS: 4047 Physical address of CCSR. CCSR can be relocated to a new 4048 physical address, if desired. In this case, this macro should 4049 be set to that address. Otherwise, it should be set to the 4050 same value as CONFIG_SYS_CCSRBAR_DEFAULT. For example, CCSR 4051 is typically relocated on 36-bit builds. It is recommended 4052 that this macro be defined via the _HIGH and _LOW macros: 4053 4054 #define CONFIG_SYS_CCSRBAR_PHYS ((CONFIG_SYS_CCSRBAR_PHYS_HIGH 4055 * 1ull) << 32 | CONFIG_SYS_CCSRBAR_PHYS_LOW) 4056 4057- CONFIG_SYS_CCSRBAR_PHYS_HIGH: 4058 Bits 33-36 of CONFIG_SYS_CCSRBAR_PHYS. This value is typically 4059 either 0 (32-bit build) or 0xF (36-bit build). This macro is 4060 used in assembly code, so it must not contain typecasts or 4061 integer size suffixes (e.g. "ULL"). 4062 4063- CONFIG_SYS_CCSRBAR_PHYS_LOW: 4064 Lower 32-bits of CONFIG_SYS_CCSRBAR_PHYS. This macro is 4065 used in assembly code, so it must not contain typecasts or 4066 integer size suffixes (e.g. "ULL"). 4067 4068- CONFIG_SYS_CCSR_DO_NOT_RELOCATE: 4069 If this macro is defined, then CONFIG_SYS_CCSRBAR_PHYS will be 4070 forced to a value that ensures that CCSR is not relocated. 4071 4072- Floppy Disk Support: 4073 CONFIG_SYS_FDC_DRIVE_NUMBER 4074 4075 the default drive number (default value 0) 4076 4077 CONFIG_SYS_ISA_IO_STRIDE 4078 4079 defines the spacing between FDC chipset registers 4080 (default value 1) 4081 4082 CONFIG_SYS_ISA_IO_OFFSET 4083 4084 defines the offset of register from address. It 4085 depends on which part of the data bus is connected to 4086 the FDC chipset. (default value 0) 4087 4088 If CONFIG_SYS_ISA_IO_STRIDE CONFIG_SYS_ISA_IO_OFFSET and 4089 CONFIG_SYS_FDC_DRIVE_NUMBER are undefined, they take their 4090 default value. 4091 4092 if CONFIG_SYS_FDC_HW_INIT is defined, then the function 4093 fdc_hw_init() is called at the beginning of the FDC 4094 setup. fdc_hw_init() must be provided by the board 4095 source code. It is used to make hardware-dependent 4096 initializations. 4097 4098- CONFIG_IDE_AHB: 4099 Most IDE controllers were designed to be connected with PCI 4100 interface. Only few of them were designed for AHB interface. 4101 When software is doing ATA command and data transfer to 4102 IDE devices through IDE-AHB controller, some additional 4103 registers accessing to these kind of IDE-AHB controller 4104 is required. 4105 4106- CONFIG_SYS_IMMR: Physical address of the Internal Memory. 4107 DO NOT CHANGE unless you know exactly what you're 4108 doing! (11-4) [MPC8xx/82xx systems only] 4109 4110- CONFIG_SYS_INIT_RAM_ADDR: 4111 4112 Start address of memory area that can be used for 4113 initial data and stack; please note that this must be 4114 writable memory that is working WITHOUT special 4115 initialization, i. e. you CANNOT use normal RAM which 4116 will become available only after programming the 4117 memory controller and running certain initialization 4118 sequences. 4119 4120 U-Boot uses the following memory types: 4121 - MPC8xx and MPC8260: IMMR (internal memory of the CPU) 4122 - MPC824X: data cache 4123 - PPC4xx: data cache 4124 4125- CONFIG_SYS_GBL_DATA_OFFSET: 4126 4127 Offset of the initial data structure in the memory 4128 area defined by CONFIG_SYS_INIT_RAM_ADDR. Usually 4129 CONFIG_SYS_GBL_DATA_OFFSET is chosen such that the initial 4130 data is located at the end of the available space 4131 (sometimes written as (CONFIG_SYS_INIT_RAM_SIZE - 4132 GENERATED_GBL_DATA_SIZE), and the initial stack is just 4133 below that area (growing from (CONFIG_SYS_INIT_RAM_ADDR + 4134 CONFIG_SYS_GBL_DATA_OFFSET) downward. 4135 4136 Note: 4137 On the MPC824X (or other systems that use the data 4138 cache for initial memory) the address chosen for 4139 CONFIG_SYS_INIT_RAM_ADDR is basically arbitrary - it must 4140 point to an otherwise UNUSED address space between 4141 the top of RAM and the start of the PCI space. 4142 4143- CONFIG_SYS_SIUMCR: SIU Module Configuration (11-6) 4144 4145- CONFIG_SYS_SYPCR: System Protection Control (11-9) 4146 4147- CONFIG_SYS_TBSCR: Time Base Status and Control (11-26) 4148 4149- CONFIG_SYS_PISCR: Periodic Interrupt Status and Control (11-31) 4150 4151- CONFIG_SYS_PLPRCR: PLL, Low-Power, and Reset Control Register (15-30) 4152 4153- CONFIG_SYS_SCCR: System Clock and reset Control Register (15-27) 4154 4155- CONFIG_SYS_OR_TIMING_SDRAM: 4156 SDRAM timing 4157 4158- CONFIG_SYS_MAMR_PTA: 4159 periodic timer for refresh 4160 4161- CONFIG_SYS_DER: Debug Event Register (37-47) 4162 4163- FLASH_BASE0_PRELIM, FLASH_BASE1_PRELIM, CONFIG_SYS_REMAP_OR_AM, 4164 CONFIG_SYS_PRELIM_OR_AM, CONFIG_SYS_OR_TIMING_FLASH, CONFIG_SYS_OR0_REMAP, 4165 CONFIG_SYS_OR0_PRELIM, CONFIG_SYS_BR0_PRELIM, CONFIG_SYS_OR1_REMAP, CONFIG_SYS_OR1_PRELIM, 4166 CONFIG_SYS_BR1_PRELIM: 4167 Memory Controller Definitions: BR0/1 and OR0/1 (FLASH) 4168 4169- SDRAM_BASE2_PRELIM, SDRAM_BASE3_PRELIM, SDRAM_MAX_SIZE, 4170 CONFIG_SYS_OR_TIMING_SDRAM, CONFIG_SYS_OR2_PRELIM, CONFIG_SYS_BR2_PRELIM, 4171 CONFIG_SYS_OR3_PRELIM, CONFIG_SYS_BR3_PRELIM: 4172 Memory Controller Definitions: BR2/3 and OR2/3 (SDRAM) 4173 4174- CONFIG_SYS_MAMR_PTA, CONFIG_SYS_MPTPR_2BK_4K, CONFIG_SYS_MPTPR_1BK_4K, CONFIG_SYS_MPTPR_2BK_8K, 4175 CONFIG_SYS_MPTPR_1BK_8K, CONFIG_SYS_MAMR_8COL, CONFIG_SYS_MAMR_9COL: 4176 Machine Mode Register and Memory Periodic Timer 4177 Prescaler definitions (SDRAM timing) 4178 4179- CONFIG_SYS_I2C_UCODE_PATCH, CONFIG_SYS_I2C_DPMEM_OFFSET [0x1FC0]: 4180 enable I2C microcode relocation patch (MPC8xx); 4181 define relocation offset in DPRAM [DSP2] 4182 4183- CONFIG_SYS_SMC_UCODE_PATCH, CONFIG_SYS_SMC_DPMEM_OFFSET [0x1FC0]: 4184 enable SMC microcode relocation patch (MPC8xx); 4185 define relocation offset in DPRAM [SMC1] 4186 4187- CONFIG_SYS_SPI_UCODE_PATCH, CONFIG_SYS_SPI_DPMEM_OFFSET [0x1FC0]: 4188 enable SPI microcode relocation patch (MPC8xx); 4189 define relocation offset in DPRAM [SCC4] 4190 4191- CONFIG_SYS_CPM_POST_WORD_ADDR: (MPC8xx, MPC8260 only) 4192 Offset of the bootmode word in DPRAM used by post 4193 (Power On Self Tests). This definition overrides 4194 #define'd default value in commproc.h resp. 4195 cpm_8260.h. 4196 4197- CONFIG_SYS_PCI_SLV_MEM_LOCAL, CONFIG_SYS_PCI_SLV_MEM_BUS, CONFIG_SYS_PICMR0_MASK_ATTRIB, 4198 CONFIG_SYS_PCI_MSTR0_LOCAL, CONFIG_SYS_PCIMSK0_MASK, CONFIG_SYS_PCI_MSTR1_LOCAL, 4199 CONFIG_SYS_PCIMSK1_MASK, CONFIG_SYS_PCI_MSTR_MEM_LOCAL, CONFIG_SYS_PCI_MSTR_MEM_BUS, 4200 CONFIG_SYS_CPU_PCI_MEM_START, CONFIG_SYS_PCI_MSTR_MEM_SIZE, CONFIG_SYS_POCMR0_MASK_ATTRIB, 4201 CONFIG_SYS_PCI_MSTR_MEMIO_LOCAL, CONFIG_SYS_PCI_MSTR_MEMIO_BUS, CPU_PCI_MEMIO_START, 4202 CONFIG_SYS_PCI_MSTR_MEMIO_SIZE, CONFIG_SYS_POCMR1_MASK_ATTRIB, CONFIG_SYS_PCI_MSTR_IO_LOCAL, 4203 CONFIG_SYS_PCI_MSTR_IO_BUS, CONFIG_SYS_CPU_PCI_IO_START, CONFIG_SYS_PCI_MSTR_IO_SIZE, 4204 CONFIG_SYS_POCMR2_MASK_ATTRIB: (MPC826x only) 4205 Overrides the default PCI memory map in arch/powerpc/cpu/mpc8260/pci.c if set. 4206 4207- CONFIG_PCI_DISABLE_PCIE: 4208 Disable PCI-Express on systems where it is supported but not 4209 required. 4210 4211- CONFIG_PCI_ENUM_ONLY 4212 Only scan through and get the devices on the buses. 4213 Don't do any setup work, presumably because someone or 4214 something has already done it, and we don't need to do it 4215 a second time. Useful for platforms that are pre-booted 4216 by coreboot or similar. 4217 4218- CONFIG_PCI_INDIRECT_BRIDGE: 4219 Enable support for indirect PCI bridges. 4220 4221- CONFIG_SYS_SRIO: 4222 Chip has SRIO or not 4223 4224- CONFIG_SRIO1: 4225 Board has SRIO 1 port available 4226 4227- CONFIG_SRIO2: 4228 Board has SRIO 2 port available 4229 4230- CONFIG_SRIO_PCIE_BOOT_MASTER 4231 Board can support master function for Boot from SRIO and PCIE 4232 4233- CONFIG_SYS_SRIOn_MEM_VIRT: 4234 Virtual Address of SRIO port 'n' memory region 4235 4236- CONFIG_SYS_SRIOn_MEM_PHYS: 4237 Physical Address of SRIO port 'n' memory region 4238 4239- CONFIG_SYS_SRIOn_MEM_SIZE: 4240 Size of SRIO port 'n' memory region 4241 4242- CONFIG_SYS_NAND_BUSWIDTH_16BIT 4243 Defined to tell the NAND controller that the NAND chip is using 4244 a 16 bit bus. 4245 Not all NAND drivers use this symbol. 4246 Example of drivers that use it: 4247 - drivers/mtd/nand/ndfc.c 4248 - drivers/mtd/nand/mxc_nand.c 4249 4250- CONFIG_SYS_NDFC_EBC0_CFG 4251 Sets the EBC0_CFG register for the NDFC. If not defined 4252 a default value will be used. 4253 4254- CONFIG_SPD_EEPROM 4255 Get DDR timing information from an I2C EEPROM. Common 4256 with pluggable memory modules such as SODIMMs 4257 4258 SPD_EEPROM_ADDRESS 4259 I2C address of the SPD EEPROM 4260 4261- CONFIG_SYS_SPD_BUS_NUM 4262 If SPD EEPROM is on an I2C bus other than the first 4263 one, specify here. Note that the value must resolve 4264 to something your driver can deal with. 4265 4266- CONFIG_SYS_DDR_RAW_TIMING 4267 Get DDR timing information from other than SPD. Common with 4268 soldered DDR chips onboard without SPD. DDR raw timing 4269 parameters are extracted from datasheet and hard-coded into 4270 header files or board specific files. 4271 4272- CONFIG_FSL_DDR_INTERACTIVE 4273 Enable interactive DDR debugging. See doc/README.fsl-ddr. 4274 4275- CONFIG_FSL_DDR_SYNC_REFRESH 4276 Enable sync of refresh for multiple controllers. 4277 4278- CONFIG_FSL_DDR_BIST 4279 Enable built-in memory test for Freescale DDR controllers. 4280 4281- CONFIG_SYS_83XX_DDR_USES_CS0 4282 Only for 83xx systems. If specified, then DDR should 4283 be configured using CS0 and CS1 instead of CS2 and CS3. 4284 4285- CONFIG_ETHER_ON_FEC[12] 4286 Define to enable FEC[12] on a 8xx series processor. 4287 4288- CONFIG_FEC[12]_PHY 4289 Define to the hardcoded PHY address which corresponds 4290 to the given FEC; i. e. 4291 #define CONFIG_FEC1_PHY 4 4292 means that the PHY with address 4 is connected to FEC1 4293 4294 When set to -1, means to probe for first available. 4295 4296- CONFIG_FEC[12]_PHY_NORXERR 4297 The PHY does not have a RXERR line (RMII only). 4298 (so program the FEC to ignore it). 4299 4300- CONFIG_RMII 4301 Enable RMII mode for all FECs. 4302 Note that this is a global option, we can't 4303 have one FEC in standard MII mode and another in RMII mode. 4304 4305- CONFIG_CRC32_VERIFY 4306 Add a verify option to the crc32 command. 4307 The syntax is: 4308 4309 => crc32 -v <address> <count> <crc32> 4310 4311 Where address/count indicate a memory area 4312 and crc32 is the correct crc32 which the 4313 area should have. 4314 4315- CONFIG_LOOPW 4316 Add the "loopw" memory command. This only takes effect if 4317 the memory commands are activated globally (CONFIG_CMD_MEM). 4318 4319- CONFIG_MX_CYCLIC 4320 Add the "mdc" and "mwc" memory commands. These are cyclic 4321 "md/mw" commands. 4322 Examples: 4323 4324 => mdc.b 10 4 500 4325 This command will print 4 bytes (10,11,12,13) each 500 ms. 4326 4327 => mwc.l 100 12345678 10 4328 This command will write 12345678 to address 100 all 10 ms. 4329 4330 This only takes effect if the memory commands are activated 4331 globally (CONFIG_CMD_MEM). 4332 4333- CONFIG_SKIP_LOWLEVEL_INIT 4334 [ARM, NDS32, MIPS only] If this variable is defined, then certain 4335 low level initializations (like setting up the memory 4336 controller) are omitted and/or U-Boot does not 4337 relocate itself into RAM. 4338 4339 Normally this variable MUST NOT be defined. The only 4340 exception is when U-Boot is loaded (to RAM) by some 4341 other boot loader or by a debugger which performs 4342 these initializations itself. 4343 4344- CONFIG_SKIP_LOWLEVEL_INIT_ONLY 4345 [ARM926EJ-S only] This allows just the call to lowlevel_init() 4346 to be skipped. The normal CP15 init (such as enabling the 4347 instruction cache) is still performed. 4348 4349- CONFIG_SPL_BUILD 4350 Modifies the behaviour of start.S when compiling a loader 4351 that is executed before the actual U-Boot. E.g. when 4352 compiling a NAND SPL. 4353 4354- CONFIG_TPL_BUILD 4355 Modifies the behaviour of start.S when compiling a loader 4356 that is executed after the SPL and before the actual U-Boot. 4357 It is loaded by the SPL. 4358 4359- CONFIG_SYS_MPC85XX_NO_RESETVEC 4360 Only for 85xx systems. If this variable is specified, the section 4361 .resetvec is not kept and the section .bootpg is placed in the 4362 previous 4k of the .text section. 4363 4364- CONFIG_ARCH_MAP_SYSMEM 4365 Generally U-Boot (and in particular the md command) uses 4366 effective address. It is therefore not necessary to regard 4367 U-Boot address as virtual addresses that need to be translated 4368 to physical addresses. However, sandbox requires this, since 4369 it maintains its own little RAM buffer which contains all 4370 addressable memory. This option causes some memory accesses 4371 to be mapped through map_sysmem() / unmap_sysmem(). 4372 4373- CONFIG_X86_RESET_VECTOR 4374 If defined, the x86 reset vector code is included. This is not 4375 needed when U-Boot is running from Coreboot. 4376 4377- CONFIG_SPL_AM33XX_ENABLE_RTC32K_OSC: 4378 Enables the RTC32K OSC on AM33xx based plattforms 4379 4380- CONFIG_SYS_NAND_NO_SUBPAGE_WRITE 4381 Option to disable subpage write in NAND driver 4382 driver that uses this: 4383 drivers/mtd/nand/davinci_nand.c 4384 4385Freescale QE/FMAN Firmware Support: 4386----------------------------------- 4387 4388The Freescale QUICCEngine (QE) and Frame Manager (FMAN) both support the 4389loading of "firmware", which is encoded in the QE firmware binary format. 4390This firmware often needs to be loaded during U-Boot booting, so macros 4391are used to identify the storage device (NOR flash, SPI, etc) and the address 4392within that device. 4393 4394- CONFIG_SYS_FMAN_FW_ADDR 4395 The address in the storage device where the FMAN microcode is located. The 4396 meaning of this address depends on which CONFIG_SYS_QE_FW_IN_xxx macro 4397 is also specified. 4398 4399- CONFIG_SYS_QE_FW_ADDR 4400 The address in the storage device where the QE microcode is located. The 4401 meaning of this address depends on which CONFIG_SYS_QE_FW_IN_xxx macro 4402 is also specified. 4403 4404- CONFIG_SYS_QE_FMAN_FW_LENGTH 4405 The maximum possible size of the firmware. The firmware binary format 4406 has a field that specifies the actual size of the firmware, but it 4407 might not be possible to read any part of the firmware unless some 4408 local storage is allocated to hold the entire firmware first. 4409 4410- CONFIG_SYS_QE_FMAN_FW_IN_NOR 4411 Specifies that QE/FMAN firmware is located in NOR flash, mapped as 4412 normal addressable memory via the LBC. CONFIG_SYS_FMAN_FW_ADDR is the 4413 virtual address in NOR flash. 4414 4415- CONFIG_SYS_QE_FMAN_FW_IN_NAND 4416 Specifies that QE/FMAN firmware is located in NAND flash. 4417 CONFIG_SYS_FMAN_FW_ADDR is the offset within NAND flash. 4418 4419- CONFIG_SYS_QE_FMAN_FW_IN_MMC 4420 Specifies that QE/FMAN firmware is located on the primary SD/MMC 4421 device. CONFIG_SYS_FMAN_FW_ADDR is the byte offset on that device. 4422 4423- CONFIG_SYS_QE_FMAN_FW_IN_REMOTE 4424 Specifies that QE/FMAN firmware is located in the remote (master) 4425 memory space. CONFIG_SYS_FMAN_FW_ADDR is a virtual address which 4426 can be mapped from slave TLB->slave LAW->slave SRIO or PCIE outbound 4427 window->master inbound window->master LAW->the ucode address in 4428 master's memory space. 4429 4430Freescale Layerscape Management Complex Firmware Support: 4431--------------------------------------------------------- 4432The Freescale Layerscape Management Complex (MC) supports the loading of 4433"firmware". 4434This firmware often needs to be loaded during U-Boot booting, so macros 4435are used to identify the storage device (NOR flash, SPI, etc) and the address 4436within that device. 4437 4438- CONFIG_FSL_MC_ENET 4439 Enable the MC driver for Layerscape SoCs. 4440 4441Freescale Layerscape Debug Server Support: 4442------------------------------------------- 4443The Freescale Layerscape Debug Server Support supports the loading of 4444"Debug Server firmware" and triggering SP boot-rom. 4445This firmware often needs to be loaded during U-Boot booting. 4446 4447- CONFIG_SYS_MC_RSV_MEM_ALIGN 4448 Define alignment of reserved memory MC requires 4449 4450Reproducible builds 4451------------------- 4452 4453In order to achieve reproducible builds, timestamps used in the U-Boot build 4454process have to be set to a fixed value. 4455 4456This is done using the SOURCE_DATE_EPOCH environment variable. 4457SOURCE_DATE_EPOCH is to be set on the build host's shell, not as a configuration 4458option for U-Boot or an environment variable in U-Boot. 4459 4460SOURCE_DATE_EPOCH should be set to a number of seconds since the epoch, in UTC. 4461 4462Building the Software: 4463====================== 4464 4465Building U-Boot has been tested in several native build environments 4466and in many different cross environments. Of course we cannot support 4467all possibly existing versions of cross development tools in all 4468(potentially obsolete) versions. In case of tool chain problems we 4469recommend to use the ELDK (see http://www.denx.de/wiki/DULG/ELDK) 4470which is extensively used to build and test U-Boot. 4471 4472If you are not using a native environment, it is assumed that you 4473have GNU cross compiling tools available in your path. In this case, 4474you must set the environment variable CROSS_COMPILE in your shell. 4475Note that no changes to the Makefile or any other source files are 4476necessary. For example using the ELDK on a 4xx CPU, please enter: 4477 4478 $ CROSS_COMPILE=ppc_4xx- 4479 $ export CROSS_COMPILE 4480 4481Note: If you wish to generate Windows versions of the utilities in 4482 the tools directory you can use the MinGW toolchain 4483 (http://www.mingw.org). Set your HOST tools to the MinGW 4484 toolchain and execute 'make tools'. For example: 4485 4486 $ make HOSTCC=i586-mingw32msvc-gcc HOSTSTRIP=i586-mingw32msvc-strip tools 4487 4488 Binaries such as tools/mkimage.exe will be created which can 4489 be executed on computers running Windows. 4490 4491U-Boot is intended to be simple to build. After installing the 4492sources you must configure U-Boot for one specific board type. This 4493is done by typing: 4494 4495 make NAME_defconfig 4496 4497where "NAME_defconfig" is the name of one of the existing configu- 4498rations; see boards.cfg for supported names. 4499 4500Note: for some board special configuration names may exist; check if 4501 additional information is available from the board vendor; for 4502 instance, the TQM823L systems are available without (standard) 4503 or with LCD support. You can select such additional "features" 4504 when choosing the configuration, i. e. 4505 4506 make TQM823L_defconfig 4507 - will configure for a plain TQM823L, i. e. no LCD support 4508 4509 make TQM823L_LCD_defconfig 4510 - will configure for a TQM823L with U-Boot console on LCD 4511 4512 etc. 4513 4514 4515Finally, type "make all", and you should get some working U-Boot 4516images ready for download to / installation on your system: 4517 4518- "u-boot.bin" is a raw binary image 4519- "u-boot" is an image in ELF binary format 4520- "u-boot.srec" is in Motorola S-Record format 4521 4522By default the build is performed locally and the objects are saved 4523in the source directory. One of the two methods can be used to change 4524this behavior and build U-Boot to some external directory: 4525 45261. Add O= to the make command line invocations: 4527 4528 make O=/tmp/build distclean 4529 make O=/tmp/build NAME_defconfig 4530 make O=/tmp/build all 4531 45322. Set environment variable KBUILD_OUTPUT to point to the desired location: 4533 4534 export KBUILD_OUTPUT=/tmp/build 4535 make distclean 4536 make NAME_defconfig 4537 make all 4538 4539Note that the command line "O=" setting overrides the KBUILD_OUTPUT environment 4540variable. 4541 4542 4543Please be aware that the Makefiles assume you are using GNU make, so 4544for instance on NetBSD you might need to use "gmake" instead of 4545native "make". 4546 4547 4548If the system board that you have is not listed, then you will need 4549to port U-Boot to your hardware platform. To do this, follow these 4550steps: 4551 45521. Create a new directory to hold your board specific code. Add any 4553 files you need. In your board directory, you will need at least 4554 the "Makefile" and a "<board>.c". 45552. Create a new configuration file "include/configs/<board>.h" for 4556 your board. 45573. If you're porting U-Boot to a new CPU, then also create a new 4558 directory to hold your CPU specific code. Add any files you need. 45594. Run "make <board>_defconfig" with your new name. 45605. Type "make", and you should get a working "u-boot.srec" file 4561 to be installed on your target system. 45626. Debug and solve any problems that might arise. 4563 [Of course, this last step is much harder than it sounds.] 4564 4565 4566Testing of U-Boot Modifications, Ports to New Hardware, etc.: 4567============================================================== 4568 4569If you have modified U-Boot sources (for instance added a new board 4570or support for new devices, a new CPU, etc.) you are expected to 4571provide feedback to the other developers. The feedback normally takes 4572the form of a "patch", i. e. a context diff against a certain (latest 4573official or latest in the git repository) version of U-Boot sources. 4574 4575But before you submit such a patch, please verify that your modifi- 4576cation did not break existing code. At least make sure that *ALL* of 4577the supported boards compile WITHOUT ANY compiler warnings. To do so, 4578just run the buildman script (tools/buildman/buildman), which will 4579configure and build U-Boot for ALL supported system. Be warned, this 4580will take a while. Please see the buildman README, or run 'buildman -H' 4581for documentation. 4582 4583 4584See also "U-Boot Porting Guide" below. 4585 4586 4587Monitor Commands - Overview: 4588============================ 4589 4590go - start application at address 'addr' 4591run - run commands in an environment variable 4592bootm - boot application image from memory 4593bootp - boot image via network using BootP/TFTP protocol 4594bootz - boot zImage from memory 4595tftpboot- boot image via network using TFTP protocol 4596 and env variables "ipaddr" and "serverip" 4597 (and eventually "gatewayip") 4598tftpput - upload a file via network using TFTP protocol 4599rarpboot- boot image via network using RARP/TFTP protocol 4600diskboot- boot from IDE devicebootd - boot default, i.e., run 'bootcmd' 4601loads - load S-Record file over serial line 4602loadb - load binary file over serial line (kermit mode) 4603md - memory display 4604mm - memory modify (auto-incrementing) 4605nm - memory modify (constant address) 4606mw - memory write (fill) 4607cp - memory copy 4608cmp - memory compare 4609crc32 - checksum calculation 4610i2c - I2C sub-system 4611sspi - SPI utility commands 4612base - print or set address offset 4613printenv- print environment variables 4614setenv - set environment variables 4615saveenv - save environment variables to persistent storage 4616protect - enable or disable FLASH write protection 4617erase - erase FLASH memory 4618flinfo - print FLASH memory information 4619nand - NAND memory operations (see doc/README.nand) 4620bdinfo - print Board Info structure 4621iminfo - print header information for application image 4622coninfo - print console devices and informations 4623ide - IDE sub-system 4624loop - infinite loop on address range 4625loopw - infinite write loop on address range 4626mtest - simple RAM test 4627icache - enable or disable instruction cache 4628dcache - enable or disable data cache 4629reset - Perform RESET of the CPU 4630echo - echo args to console 4631version - print monitor version 4632help - print online help 4633? - alias for 'help' 4634 4635 4636Monitor Commands - Detailed Description: 4637======================================== 4638 4639TODO. 4640 4641For now: just type "help <command>". 4642 4643 4644Environment Variables: 4645====================== 4646 4647U-Boot supports user configuration using Environment Variables which 4648can be made persistent by saving to Flash memory. 4649 4650Environment Variables are set using "setenv", printed using 4651"printenv", and saved to Flash using "saveenv". Using "setenv" 4652without a value can be used to delete a variable from the 4653environment. As long as you don't save the environment you are 4654working with an in-memory copy. In case the Flash area containing the 4655environment is erased by accident, a default environment is provided. 4656 4657Some configuration options can be set using Environment Variables. 4658 4659List of environment variables (most likely not complete): 4660 4661 baudrate - see CONFIG_BAUDRATE 4662 4663 bootdelay - see CONFIG_BOOTDELAY 4664 4665 bootcmd - see CONFIG_BOOTCOMMAND 4666 4667 bootargs - Boot arguments when booting an RTOS image 4668 4669 bootfile - Name of the image to load with TFTP 4670 4671 bootm_low - Memory range available for image processing in the bootm 4672 command can be restricted. This variable is given as 4673 a hexadecimal number and defines lowest address allowed 4674 for use by the bootm command. See also "bootm_size" 4675 environment variable. Address defined by "bootm_low" is 4676 also the base of the initial memory mapping for the Linux 4677 kernel -- see the description of CONFIG_SYS_BOOTMAPSZ and 4678 bootm_mapsize. 4679 4680 bootm_mapsize - Size of the initial memory mapping for the Linux kernel. 4681 This variable is given as a hexadecimal number and it 4682 defines the size of the memory region starting at base 4683 address bootm_low that is accessible by the Linux kernel 4684 during early boot. If unset, CONFIG_SYS_BOOTMAPSZ is used 4685 as the default value if it is defined, and bootm_size is 4686 used otherwise. 4687 4688 bootm_size - Memory range available for image processing in the bootm 4689 command can be restricted. This variable is given as 4690 a hexadecimal number and defines the size of the region 4691 allowed for use by the bootm command. See also "bootm_low" 4692 environment variable. 4693 4694 updatefile - Location of the software update file on a TFTP server, used 4695 by the automatic software update feature. Please refer to 4696 documentation in doc/README.update for more details. 4697 4698 autoload - if set to "no" (any string beginning with 'n'), 4699 "bootp" will just load perform a lookup of the 4700 configuration from the BOOTP server, but not try to 4701 load any image using TFTP 4702 4703 autostart - if set to "yes", an image loaded using the "bootp", 4704 "rarpboot", "tftpboot" or "diskboot" commands will 4705 be automatically started (by internally calling 4706 "bootm") 4707 4708 If set to "no", a standalone image passed to the 4709 "bootm" command will be copied to the load address 4710 (and eventually uncompressed), but NOT be started. 4711 This can be used to load and uncompress arbitrary 4712 data. 4713 4714 fdt_high - if set this restricts the maximum address that the 4715 flattened device tree will be copied into upon boot. 4716 For example, if you have a system with 1 GB memory 4717 at physical address 0x10000000, while Linux kernel 4718 only recognizes the first 704 MB as low memory, you 4719 may need to set fdt_high as 0x3C000000 to have the 4720 device tree blob be copied to the maximum address 4721 of the 704 MB low memory, so that Linux kernel can 4722 access it during the boot procedure. 4723 4724 If this is set to the special value 0xFFFFFFFF then 4725 the fdt will not be copied at all on boot. For this 4726 to work it must reside in writable memory, have 4727 sufficient padding on the end of it for u-boot to 4728 add the information it needs into it, and the memory 4729 must be accessible by the kernel. 4730 4731 fdtcontroladdr- if set this is the address of the control flattened 4732 device tree used by U-Boot when CONFIG_OF_CONTROL is 4733 defined. 4734 4735 i2cfast - (PPC405GP|PPC405EP only) 4736 if set to 'y' configures Linux I2C driver for fast 4737 mode (400kHZ). This environment variable is used in 4738 initialization code. So, for changes to be effective 4739 it must be saved and board must be reset. 4740 4741 initrd_high - restrict positioning of initrd images: 4742 If this variable is not set, initrd images will be 4743 copied to the highest possible address in RAM; this 4744 is usually what you want since it allows for 4745 maximum initrd size. If for some reason you want to 4746 make sure that the initrd image is loaded below the 4747 CONFIG_SYS_BOOTMAPSZ limit, you can set this environment 4748 variable to a value of "no" or "off" or "0". 4749 Alternatively, you can set it to a maximum upper 4750 address to use (U-Boot will still check that it 4751 does not overwrite the U-Boot stack and data). 4752 4753 For instance, when you have a system with 16 MB 4754 RAM, and want to reserve 4 MB from use by Linux, 4755 you can do this by adding "mem=12M" to the value of 4756 the "bootargs" variable. However, now you must make 4757 sure that the initrd image is placed in the first 4758 12 MB as well - this can be done with 4759 4760 setenv initrd_high 00c00000 4761 4762 If you set initrd_high to 0xFFFFFFFF, this is an 4763 indication to U-Boot that all addresses are legal 4764 for the Linux kernel, including addresses in flash 4765 memory. In this case U-Boot will NOT COPY the 4766 ramdisk at all. This may be useful to reduce the 4767 boot time on your system, but requires that this 4768 feature is supported by your Linux kernel. 4769 4770 ipaddr - IP address; needed for tftpboot command 4771 4772 loadaddr - Default load address for commands like "bootp", 4773 "rarpboot", "tftpboot", "loadb" or "diskboot" 4774 4775 loads_echo - see CONFIG_LOADS_ECHO 4776 4777 serverip - TFTP server IP address; needed for tftpboot command 4778 4779 bootretry - see CONFIG_BOOT_RETRY_TIME 4780 4781 bootdelaykey - see CONFIG_AUTOBOOT_DELAY_STR 4782 4783 bootstopkey - see CONFIG_AUTOBOOT_STOP_STR 4784 4785 ethprime - controls which interface is used first. 4786 4787 ethact - controls which interface is currently active. 4788 For example you can do the following 4789 4790 => setenv ethact FEC 4791 => ping 192.168.0.1 # traffic sent on FEC 4792 => setenv ethact SCC 4793 => ping 10.0.0.1 # traffic sent on SCC 4794 4795 ethrotate - When set to "no" U-Boot does not go through all 4796 available network interfaces. 4797 It just stays at the currently selected interface. 4798 4799 netretry - When set to "no" each network operation will 4800 either succeed or fail without retrying. 4801 When set to "once" the network operation will 4802 fail when all the available network interfaces 4803 are tried once without success. 4804 Useful on scripts which control the retry operation 4805 themselves. 4806 4807 npe_ucode - set load address for the NPE microcode 4808 4809 silent_linux - If set then Linux will be told to boot silently, by 4810 changing the console to be empty. If "yes" it will be 4811 made silent. If "no" it will not be made silent. If 4812 unset, then it will be made silent if the U-Boot console 4813 is silent. 4814 4815 tftpsrcp - If this is set, the value is used for TFTP's 4816 UDP source port. 4817 4818 tftpdstp - If this is set, the value is used for TFTP's UDP 4819 destination port instead of the Well Know Port 69. 4820 4821 tftpblocksize - Block size to use for TFTP transfers; if not set, 4822 we use the TFTP server's default block size 4823 4824 tftptimeout - Retransmission timeout for TFTP packets (in milli- 4825 seconds, minimum value is 1000 = 1 second). Defines 4826 when a packet is considered to be lost so it has to 4827 be retransmitted. The default is 5000 = 5 seconds. 4828 Lowering this value may make downloads succeed 4829 faster in networks with high packet loss rates or 4830 with unreliable TFTP servers. 4831 4832 tftptimeoutcountmax - maximum count of TFTP timeouts (no 4833 unit, minimum value = 0). Defines how many timeouts 4834 can happen during a single file transfer before that 4835 transfer is aborted. The default is 10, and 0 means 4836 'no timeouts allowed'. Increasing this value may help 4837 downloads succeed with high packet loss rates, or with 4838 unreliable TFTP servers or client hardware. 4839 4840 vlan - When set to a value < 4095 the traffic over 4841 Ethernet is encapsulated/received over 802.1q 4842 VLAN tagged frames. 4843 4844 bootpretryperiod - Period during which BOOTP/DHCP sends retries. 4845 Unsigned value, in milliseconds. If not set, the period will 4846 be either the default (28000), or a value based on 4847 CONFIG_NET_RETRY_COUNT, if defined. This value has 4848 precedence over the valu based on CONFIG_NET_RETRY_COUNT. 4849 4850The following image location variables contain the location of images 4851used in booting. The "Image" column gives the role of the image and is 4852not an environment variable name. The other columns are environment 4853variable names. "File Name" gives the name of the file on a TFTP 4854server, "RAM Address" gives the location in RAM the image will be 4855loaded to, and "Flash Location" gives the image's address in NOR 4856flash or offset in NAND flash. 4857 4858*Note* - these variables don't have to be defined for all boards, some 4859boards currently use other variables for these purposes, and some 4860boards use these variables for other purposes. 4861 4862Image File Name RAM Address Flash Location 4863----- --------- ----------- -------------- 4864u-boot u-boot u-boot_addr_r u-boot_addr 4865Linux kernel bootfile kernel_addr_r kernel_addr 4866device tree blob fdtfile fdt_addr_r fdt_addr 4867ramdisk ramdiskfile ramdisk_addr_r ramdisk_addr 4868 4869The following environment variables may be used and automatically 4870updated by the network boot commands ("bootp" and "rarpboot"), 4871depending the information provided by your boot server: 4872 4873 bootfile - see above 4874 dnsip - IP address of your Domain Name Server 4875 dnsip2 - IP address of your secondary Domain Name Server 4876 gatewayip - IP address of the Gateway (Router) to use 4877 hostname - Target hostname 4878 ipaddr - see above 4879 netmask - Subnet Mask 4880 rootpath - Pathname of the root filesystem on the NFS server 4881 serverip - see above 4882 4883 4884There are two special Environment Variables: 4885 4886 serial# - contains hardware identification information such 4887 as type string and/or serial number 4888 ethaddr - Ethernet address 4889 4890These variables can be set only once (usually during manufacturing of 4891the board). U-Boot refuses to delete or overwrite these variables 4892once they have been set once. 4893 4894 4895Further special Environment Variables: 4896 4897 ver - Contains the U-Boot version string as printed 4898 with the "version" command. This variable is 4899 readonly (see CONFIG_VERSION_VARIABLE). 4900 4901 4902Please note that changes to some configuration parameters may take 4903only effect after the next boot (yes, that's just like Windoze :-). 4904 4905 4906Callback functions for environment variables: 4907--------------------------------------------- 4908 4909For some environment variables, the behavior of u-boot needs to change 4910when their values are changed. This functionality allows functions to 4911be associated with arbitrary variables. On creation, overwrite, or 4912deletion, the callback will provide the opportunity for some side 4913effect to happen or for the change to be rejected. 4914 4915The callbacks are named and associated with a function using the 4916U_BOOT_ENV_CALLBACK macro in your board or driver code. 4917 4918These callbacks are associated with variables in one of two ways. The 4919static list can be added to by defining CONFIG_ENV_CALLBACK_LIST_STATIC 4920in the board configuration to a string that defines a list of 4921associations. The list must be in the following format: 4922 4923 entry = variable_name[:callback_name] 4924 list = entry[,list] 4925 4926If the callback name is not specified, then the callback is deleted. 4927Spaces are also allowed anywhere in the list. 4928 4929Callbacks can also be associated by defining the ".callbacks" variable 4930with the same list format above. Any association in ".callbacks" will 4931override any association in the static list. You can define 4932CONFIG_ENV_CALLBACK_LIST_DEFAULT to a list (string) to define the 4933".callbacks" environment variable in the default or embedded environment. 4934 4935If CONFIG_REGEX is defined, the variable_name above is evaluated as a 4936regular expression. This allows multiple variables to be connected to 4937the same callback without explicitly listing them all out. 4938 4939 4940Command Line Parsing: 4941===================== 4942 4943There are two different command line parsers available with U-Boot: 4944the old "simple" one, and the much more powerful "hush" shell: 4945 4946Old, simple command line parser: 4947-------------------------------- 4948 4949- supports environment variables (through setenv / saveenv commands) 4950- several commands on one line, separated by ';' 4951- variable substitution using "... ${name} ..." syntax 4952- special characters ('$', ';') can be escaped by prefixing with '\', 4953 for example: 4954 setenv bootcmd bootm \${address} 4955- You can also escape text by enclosing in single apostrophes, for example: 4956 setenv addip 'setenv bootargs $bootargs ip=$ipaddr:$serverip:$gatewayip:$netmask:$hostname::off' 4957 4958Hush shell: 4959----------- 4960 4961- similar to Bourne shell, with control structures like 4962 if...then...else...fi, for...do...done; while...do...done, 4963 until...do...done, ... 4964- supports environment ("global") variables (through setenv / saveenv 4965 commands) and local shell variables (through standard shell syntax 4966 "name=value"); only environment variables can be used with "run" 4967 command 4968 4969General rules: 4970-------------- 4971 4972(1) If a command line (or an environment variable executed by a "run" 4973 command) contains several commands separated by semicolon, and 4974 one of these commands fails, then the remaining commands will be 4975 executed anyway. 4976 4977(2) If you execute several variables with one call to run (i. e. 4978 calling run with a list of variables as arguments), any failing 4979 command will cause "run" to terminate, i. e. the remaining 4980 variables are not executed. 4981 4982Note for Redundant Ethernet Interfaces: 4983======================================= 4984 4985Some boards come with redundant Ethernet interfaces; U-Boot supports 4986such configurations and is capable of automatic selection of a 4987"working" interface when needed. MAC assignment works as follows: 4988 4989Network interfaces are numbered eth0, eth1, eth2, ... Corresponding 4990MAC addresses can be stored in the environment as "ethaddr" (=>eth0), 4991"eth1addr" (=>eth1), "eth2addr", ... 4992 4993If the network interface stores some valid MAC address (for instance 4994in SROM), this is used as default address if there is NO correspon- 4995ding setting in the environment; if the corresponding environment 4996variable is set, this overrides the settings in the card; that means: 4997 4998o If the SROM has a valid MAC address, and there is no address in the 4999 environment, the SROM's address is used. 5000 5001o If there is no valid address in the SROM, and a definition in the 5002 environment exists, then the value from the environment variable is 5003 used. 5004 5005o If both the SROM and the environment contain a MAC address, and 5006 both addresses are the same, this MAC address is used. 5007 5008o If both the SROM and the environment contain a MAC address, and the 5009 addresses differ, the value from the environment is used and a 5010 warning is printed. 5011 5012o If neither SROM nor the environment contain a MAC address, an error 5013 is raised. If CONFIG_NET_RANDOM_ETHADDR is defined, then in this case 5014 a random, locally-assigned MAC is used. 5015 5016If Ethernet drivers implement the 'write_hwaddr' function, valid MAC addresses 5017will be programmed into hardware as part of the initialization process. This 5018may be skipped by setting the appropriate 'ethmacskip' environment variable. 5019The naming convention is as follows: 5020"ethmacskip" (=>eth0), "eth1macskip" (=>eth1) etc. 5021 5022Image Formats: 5023============== 5024 5025U-Boot is capable of booting (and performing other auxiliary operations on) 5026images in two formats: 5027 5028New uImage format (FIT) 5029----------------------- 5030 5031Flexible and powerful format based on Flattened Image Tree -- FIT (similar 5032to Flattened Device Tree). It allows the use of images with multiple 5033components (several kernels, ramdisks, etc.), with contents protected by 5034SHA1, MD5 or CRC32. More details are found in the doc/uImage.FIT directory. 5035 5036 5037Old uImage format 5038----------------- 5039 5040Old image format is based on binary files which can be basically anything, 5041preceded by a special header; see the definitions in include/image.h for 5042details; basically, the header defines the following image properties: 5043 5044* Target Operating System (Provisions for OpenBSD, NetBSD, FreeBSD, 5045 4.4BSD, Linux, SVR4, Esix, Solaris, Irix, SCO, Dell, NCR, VxWorks, 5046 LynxOS, pSOS, QNX, RTEMS, INTEGRITY; 5047 Currently supported: Linux, NetBSD, VxWorks, QNX, RTEMS, LynxOS, 5048 INTEGRITY). 5049* Target CPU Architecture (Provisions for Alpha, ARM, AVR32, Intel x86, 5050 IA64, MIPS, NDS32, Nios II, PowerPC, IBM S390, SuperH, Sparc, Sparc 64 Bit; 5051 Currently supported: ARM, AVR32, Intel x86, MIPS, NDS32, Nios II, PowerPC). 5052* Compression Type (uncompressed, gzip, bzip2) 5053* Load Address 5054* Entry Point 5055* Image Name 5056* Image Timestamp 5057 5058The header is marked by a special Magic Number, and both the header 5059and the data portions of the image are secured against corruption by 5060CRC32 checksums. 5061 5062 5063Linux Support: 5064============== 5065 5066Although U-Boot should support any OS or standalone application 5067easily, the main focus has always been on Linux during the design of 5068U-Boot. 5069 5070U-Boot includes many features that so far have been part of some 5071special "boot loader" code within the Linux kernel. Also, any 5072"initrd" images to be used are no longer part of one big Linux image; 5073instead, kernel and "initrd" are separate images. This implementation 5074serves several purposes: 5075 5076- the same features can be used for other OS or standalone 5077 applications (for instance: using compressed images to reduce the 5078 Flash memory footprint) 5079 5080- it becomes much easier to port new Linux kernel versions because 5081 lots of low-level, hardware dependent stuff are done by U-Boot 5082 5083- the same Linux kernel image can now be used with different "initrd" 5084 images; of course this also means that different kernel images can 5085 be run with the same "initrd". This makes testing easier (you don't 5086 have to build a new "zImage.initrd" Linux image when you just 5087 change a file in your "initrd"). Also, a field-upgrade of the 5088 software is easier now. 5089 5090 5091Linux HOWTO: 5092============ 5093 5094Porting Linux to U-Boot based systems: 5095--------------------------------------- 5096 5097U-Boot cannot save you from doing all the necessary modifications to 5098configure the Linux device drivers for use with your target hardware 5099(no, we don't intend to provide a full virtual machine interface to 5100Linux :-). 5101 5102But now you can ignore ALL boot loader code (in arch/powerpc/mbxboot). 5103 5104Just make sure your machine specific header file (for instance 5105include/asm-ppc/tqm8xx.h) includes the same definition of the Board 5106Information structure as we define in include/asm-<arch>/u-boot.h, 5107and make sure that your definition of IMAP_ADDR uses the same value 5108as your U-Boot configuration in CONFIG_SYS_IMMR. 5109 5110Note that U-Boot now has a driver model, a unified model for drivers. 5111If you are adding a new driver, plumb it into driver model. If there 5112is no uclass available, you are encouraged to create one. See 5113doc/driver-model. 5114 5115 5116Configuring the Linux kernel: 5117----------------------------- 5118 5119No specific requirements for U-Boot. Make sure you have some root 5120device (initial ramdisk, NFS) for your target system. 5121 5122 5123Building a Linux Image: 5124----------------------- 5125 5126With U-Boot, "normal" build targets like "zImage" or "bzImage" are 5127not used. If you use recent kernel source, a new build target 5128"uImage" will exist which automatically builds an image usable by 5129U-Boot. Most older kernels also have support for a "pImage" target, 5130which was introduced for our predecessor project PPCBoot and uses a 5131100% compatible format. 5132 5133Example: 5134 5135 make TQM850L_defconfig 5136 make oldconfig 5137 make dep 5138 make uImage 5139 5140The "uImage" build target uses a special tool (in 'tools/mkimage') to 5141encapsulate a compressed Linux kernel image with header information, 5142CRC32 checksum etc. for use with U-Boot. This is what we are doing: 5143 5144* build a standard "vmlinux" kernel image (in ELF binary format): 5145 5146* convert the kernel into a raw binary image: 5147 5148 ${CROSS_COMPILE}-objcopy -O binary \ 5149 -R .note -R .comment \ 5150 -S vmlinux linux.bin 5151 5152* compress the binary image: 5153 5154 gzip -9 linux.bin 5155 5156* package compressed binary image for U-Boot: 5157 5158 mkimage -A ppc -O linux -T kernel -C gzip \ 5159 -a 0 -e 0 -n "Linux Kernel Image" \ 5160 -d linux.bin.gz uImage 5161 5162 5163The "mkimage" tool can also be used to create ramdisk images for use 5164with U-Boot, either separated from the Linux kernel image, or 5165combined into one file. "mkimage" encapsulates the images with a 64 5166byte header containing information about target architecture, 5167operating system, image type, compression method, entry points, time 5168stamp, CRC32 checksums, etc. 5169 5170"mkimage" can be called in two ways: to verify existing images and 5171print the header information, or to build new images. 5172 5173In the first form (with "-l" option) mkimage lists the information 5174contained in the header of an existing U-Boot image; this includes 5175checksum verification: 5176 5177 tools/mkimage -l image 5178 -l ==> list image header information 5179 5180The second form (with "-d" option) is used to build a U-Boot image 5181from a "data file" which is used as image payload: 5182 5183 tools/mkimage -A arch -O os -T type -C comp -a addr -e ep \ 5184 -n name -d data_file image 5185 -A ==> set architecture to 'arch' 5186 -O ==> set operating system to 'os' 5187 -T ==> set image type to 'type' 5188 -C ==> set compression type 'comp' 5189 -a ==> set load address to 'addr' (hex) 5190 -e ==> set entry point to 'ep' (hex) 5191 -n ==> set image name to 'name' 5192 -d ==> use image data from 'datafile' 5193 5194Right now, all Linux kernels for PowerPC systems use the same load 5195address (0x00000000), but the entry point address depends on the 5196kernel version: 5197 5198- 2.2.x kernels have the entry point at 0x0000000C, 5199- 2.3.x and later kernels have the entry point at 0x00000000. 5200 5201So a typical call to build a U-Boot image would read: 5202 5203 -> tools/mkimage -n '2.4.4 kernel for TQM850L' \ 5204 > -A ppc -O linux -T kernel -C gzip -a 0 -e 0 \ 5205 > -d /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/powerpc/coffboot/vmlinux.gz \ 5206 > examples/uImage.TQM850L 5207 Image Name: 2.4.4 kernel for TQM850L 5208 Created: Wed Jul 19 02:34:59 2000 5209 Image Type: PowerPC Linux Kernel Image (gzip compressed) 5210 Data Size: 335725 Bytes = 327.86 kB = 0.32 MB 5211 Load Address: 0x00000000 5212 Entry Point: 0x00000000 5213 5214To verify the contents of the image (or check for corruption): 5215 5216 -> tools/mkimage -l examples/uImage.TQM850L 5217 Image Name: 2.4.4 kernel for TQM850L 5218 Created: Wed Jul 19 02:34:59 2000 5219 Image Type: PowerPC Linux Kernel Image (gzip compressed) 5220 Data Size: 335725 Bytes = 327.86 kB = 0.32 MB 5221 Load Address: 0x00000000 5222 Entry Point: 0x00000000 5223 5224NOTE: for embedded systems where boot time is critical you can trade 5225speed for memory and install an UNCOMPRESSED image instead: this 5226needs more space in Flash, but boots much faster since it does not 5227need to be uncompressed: 5228 5229 -> gunzip /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/powerpc/coffboot/vmlinux.gz 5230 -> tools/mkimage -n '2.4.4 kernel for TQM850L' \ 5231 > -A ppc -O linux -T kernel -C none -a 0 -e 0 \ 5232 > -d /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/powerpc/coffboot/vmlinux \ 5233 > examples/uImage.TQM850L-uncompressed 5234 Image Name: 2.4.4 kernel for TQM850L 5235 Created: Wed Jul 19 02:34:59 2000 5236 Image Type: PowerPC Linux Kernel Image (uncompressed) 5237 Data Size: 792160 Bytes = 773.59 kB = 0.76 MB 5238 Load Address: 0x00000000 5239 Entry Point: 0x00000000 5240 5241 5242Similar you can build U-Boot images from a 'ramdisk.image.gz' file 5243when your kernel is intended to use an initial ramdisk: 5244 5245 -> tools/mkimage -n 'Simple Ramdisk Image' \ 5246 > -A ppc -O linux -T ramdisk -C gzip \ 5247 > -d /LinuxPPC/images/SIMPLE-ramdisk.image.gz examples/simple-initrd 5248 Image Name: Simple Ramdisk Image 5249 Created: Wed Jan 12 14:01:50 2000 5250 Image Type: PowerPC Linux RAMDisk Image (gzip compressed) 5251 Data Size: 566530 Bytes = 553.25 kB = 0.54 MB 5252 Load Address: 0x00000000 5253 Entry Point: 0x00000000 5254 5255The "dumpimage" is a tool to disassemble images built by mkimage. Its "-i" 5256option performs the converse operation of the mkimage's second form (the "-d" 5257option). Given an image built by mkimage, the dumpimage extracts a "data file" 5258from the image: 5259 5260 tools/dumpimage -i image -T type -p position data_file 5261 -i ==> extract from the 'image' a specific 'data_file' 5262 -T ==> set image type to 'type' 5263 -p ==> 'position' (starting at 0) of the 'data_file' inside the 'image' 5264 5265 5266Installing a Linux Image: 5267------------------------- 5268 5269To downloading a U-Boot image over the serial (console) interface, 5270you must convert the image to S-Record format: 5271 5272 objcopy -I binary -O srec examples/image examples/image.srec 5273 5274The 'objcopy' does not understand the information in the U-Boot 5275image header, so the resulting S-Record file will be relative to 5276address 0x00000000. To load it to a given address, you need to 5277specify the target address as 'offset' parameter with the 'loads' 5278command. 5279 5280Example: install the image to address 0x40100000 (which on the 5281TQM8xxL is in the first Flash bank): 5282 5283 => erase 40100000 401FFFFF 5284 5285 .......... done 5286 Erased 8 sectors 5287 5288 => loads 40100000 5289 ## Ready for S-Record download ... 5290 ~>examples/image.srec 5291 1 2 3 4 5 6 7 8 9 10 11 12 13 ... 5292 ... 5293 15989 15990 15991 15992 5294 [file transfer complete] 5295 [connected] 5296 ## Start Addr = 0x00000000 5297 5298 5299You can check the success of the download using the 'iminfo' command; 5300this includes a checksum verification so you can be sure no data 5301corruption happened: 5302 5303 => imi 40100000 5304 5305 ## Checking Image at 40100000 ... 5306 Image Name: 2.2.13 for initrd on TQM850L 5307 Image Type: PowerPC Linux Kernel Image (gzip compressed) 5308 Data Size: 335725 Bytes = 327 kB = 0 MB 5309 Load Address: 00000000 5310 Entry Point: 0000000c 5311 Verifying Checksum ... OK 5312 5313 5314Boot Linux: 5315----------- 5316 5317The "bootm" command is used to boot an application that is stored in 5318memory (RAM or Flash). In case of a Linux kernel image, the contents 5319of the "bootargs" environment variable is passed to the kernel as 5320parameters. You can check and modify this variable using the 5321"printenv" and "setenv" commands: 5322 5323 5324 => printenv bootargs 5325 bootargs=root=/dev/ram 5326 5327 => setenv bootargs root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2 5328 5329 => printenv bootargs 5330 bootargs=root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2 5331 5332 => bootm 40020000 5333 ## Booting Linux kernel at 40020000 ... 5334 Image Name: 2.2.13 for NFS on TQM850L 5335 Image Type: PowerPC Linux Kernel Image (gzip compressed) 5336 Data Size: 381681 Bytes = 372 kB = 0 MB 5337 Load Address: 00000000 5338 Entry Point: 0000000c 5339 Verifying Checksum ... OK 5340 Uncompressing Kernel Image ... OK 5341 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 5342 Boot arguments: root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2 5343 time_init: decrementer frequency = 187500000/60 5344 Calibrating delay loop... 49.77 BogoMIPS 5345 Memory: 15208k available (700k kernel code, 444k data, 32k init) [c0000000,c1000000] 5346 ... 5347 5348If you want to boot a Linux kernel with initial RAM disk, you pass 5349the memory addresses of both the kernel and the initrd image (PPBCOOT 5350format!) to the "bootm" command: 5351 5352 => imi 40100000 40200000 5353 5354 ## Checking Image at 40100000 ... 5355 Image Name: 2.2.13 for initrd on TQM850L 5356 Image Type: PowerPC Linux Kernel Image (gzip compressed) 5357 Data Size: 335725 Bytes = 327 kB = 0 MB 5358 Load Address: 00000000 5359 Entry Point: 0000000c 5360 Verifying Checksum ... OK 5361 5362 ## Checking Image at 40200000 ... 5363 Image Name: Simple Ramdisk Image 5364 Image Type: PowerPC Linux RAMDisk Image (gzip compressed) 5365 Data Size: 566530 Bytes = 553 kB = 0 MB 5366 Load Address: 00000000 5367 Entry Point: 00000000 5368 Verifying Checksum ... OK 5369 5370 => bootm 40100000 40200000 5371 ## Booting Linux kernel at 40100000 ... 5372 Image Name: 2.2.13 for initrd on TQM850L 5373 Image Type: PowerPC Linux Kernel Image (gzip compressed) 5374 Data Size: 335725 Bytes = 327 kB = 0 MB 5375 Load Address: 00000000 5376 Entry Point: 0000000c 5377 Verifying Checksum ... OK 5378 Uncompressing Kernel Image ... OK 5379 ## Loading RAMDisk Image at 40200000 ... 5380 Image Name: Simple Ramdisk Image 5381 Image Type: PowerPC Linux RAMDisk Image (gzip compressed) 5382 Data Size: 566530 Bytes = 553 kB = 0 MB 5383 Load Address: 00000000 5384 Entry Point: 00000000 5385 Verifying Checksum ... OK 5386 Loading Ramdisk ... OK 5387 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 5388 Boot arguments: root=/dev/ram 5389 time_init: decrementer frequency = 187500000/60 5390 Calibrating delay loop... 49.77 BogoMIPS 5391 ... 5392 RAMDISK: Compressed image found at block 0 5393 VFS: Mounted root (ext2 filesystem). 5394 5395 bash# 5396 5397Boot Linux and pass a flat device tree: 5398----------- 5399 5400First, U-Boot must be compiled with the appropriate defines. See the section 5401titled "Linux Kernel Interface" above for a more in depth explanation. The 5402following is an example of how to start a kernel and pass an updated 5403flat device tree: 5404 5405=> print oftaddr 5406oftaddr=0x300000 5407=> print oft 5408oft=oftrees/mpc8540ads.dtb 5409=> tftp $oftaddr $oft 5410Speed: 1000, full duplex 5411Using TSEC0 device 5412TFTP from server 192.168.1.1; our IP address is 192.168.1.101 5413Filename 'oftrees/mpc8540ads.dtb'. 5414Load address: 0x300000 5415Loading: # 5416done 5417Bytes transferred = 4106 (100a hex) 5418=> tftp $loadaddr $bootfile 5419Speed: 1000, full duplex 5420Using TSEC0 device 5421TFTP from server 192.168.1.1; our IP address is 192.168.1.2 5422Filename 'uImage'. 5423Load address: 0x200000 5424Loading:############ 5425done 5426Bytes transferred = 1029407 (fb51f hex) 5427=> print loadaddr 5428loadaddr=200000 5429=> print oftaddr 5430oftaddr=0x300000 5431=> bootm $loadaddr - $oftaddr 5432## Booting image at 00200000 ... 5433 Image Name: Linux-2.6.17-dirty 5434 Image Type: PowerPC Linux Kernel Image (gzip compressed) 5435 Data Size: 1029343 Bytes = 1005.2 kB 5436 Load Address: 00000000 5437 Entry Point: 00000000 5438 Verifying Checksum ... OK 5439 Uncompressing Kernel Image ... OK 5440Booting using flat device tree at 0x300000 5441Using MPC85xx ADS machine description 5442Memory CAM mapping: CAM0=256Mb, CAM1=256Mb, CAM2=0Mb residual: 0Mb 5443[snip] 5444 5445 5446More About U-Boot Image Types: 5447------------------------------ 5448 5449U-Boot supports the following image types: 5450 5451 "Standalone Programs" are directly runnable in the environment 5452 provided by U-Boot; it is expected that (if they behave 5453 well) you can continue to work in U-Boot after return from 5454 the Standalone Program. 5455 "OS Kernel Images" are usually images of some Embedded OS which 5456 will take over control completely. Usually these programs 5457 will install their own set of exception handlers, device 5458 drivers, set up the MMU, etc. - this means, that you cannot 5459 expect to re-enter U-Boot except by resetting the CPU. 5460 "RAMDisk Images" are more or less just data blocks, and their 5461 parameters (address, size) are passed to an OS kernel that is 5462 being started. 5463 "Multi-File Images" contain several images, typically an OS 5464 (Linux) kernel image and one or more data images like 5465 RAMDisks. This construct is useful for instance when you want 5466 to boot over the network using BOOTP etc., where the boot 5467 server provides just a single image file, but you want to get 5468 for instance an OS kernel and a RAMDisk image. 5469 5470 "Multi-File Images" start with a list of image sizes, each 5471 image size (in bytes) specified by an "uint32_t" in network 5472 byte order. This list is terminated by an "(uint32_t)0". 5473 Immediately after the terminating 0 follow the images, one by 5474 one, all aligned on "uint32_t" boundaries (size rounded up to 5475 a multiple of 4 bytes). 5476 5477 "Firmware Images" are binary images containing firmware (like 5478 U-Boot or FPGA images) which usually will be programmed to 5479 flash memory. 5480 5481 "Script files" are command sequences that will be executed by 5482 U-Boot's command interpreter; this feature is especially 5483 useful when you configure U-Boot to use a real shell (hush) 5484 as command interpreter. 5485 5486Booting the Linux zImage: 5487------------------------- 5488 5489On some platforms, it's possible to boot Linux zImage. This is done 5490using the "bootz" command. The syntax of "bootz" command is the same 5491as the syntax of "bootm" command. 5492 5493Note, defining the CONFIG_SUPPORT_RAW_INITRD allows user to supply 5494kernel with raw initrd images. The syntax is slightly different, the 5495address of the initrd must be augmented by it's size, in the following 5496format: "<initrd addres>:<initrd size>". 5497 5498 5499Standalone HOWTO: 5500================= 5501 5502One of the features of U-Boot is that you can dynamically load and 5503run "standalone" applications, which can use some resources of 5504U-Boot like console I/O functions or interrupt services. 5505 5506Two simple examples are included with the sources: 5507 5508"Hello World" Demo: 5509------------------- 5510 5511'examples/hello_world.c' contains a small "Hello World" Demo 5512application; it is automatically compiled when you build U-Boot. 5513It's configured to run at address 0x00040004, so you can play with it 5514like that: 5515 5516 => loads 5517 ## Ready for S-Record download ... 5518 ~>examples/hello_world.srec 5519 1 2 3 4 5 6 7 8 9 10 11 ... 5520 [file transfer complete] 5521 [connected] 5522 ## Start Addr = 0x00040004 5523 5524 => go 40004 Hello World! This is a test. 5525 ## Starting application at 0x00040004 ... 5526 Hello World 5527 argc = 7 5528 argv[0] = "40004" 5529 argv[1] = "Hello" 5530 argv[2] = "World!" 5531 argv[3] = "This" 5532 argv[4] = "is" 5533 argv[5] = "a" 5534 argv[6] = "test." 5535 argv[7] = "<NULL>" 5536 Hit any key to exit ... 5537 5538 ## Application terminated, rc = 0x0 5539 5540Another example, which demonstrates how to register a CPM interrupt 5541handler with the U-Boot code, can be found in 'examples/timer.c'. 5542Here, a CPM timer is set up to generate an interrupt every second. 5543The interrupt service routine is trivial, just printing a '.' 5544character, but this is just a demo program. The application can be 5545controlled by the following keys: 5546 5547 ? - print current values og the CPM Timer registers 5548 b - enable interrupts and start timer 5549 e - stop timer and disable interrupts 5550 q - quit application 5551 5552 => loads 5553 ## Ready for S-Record download ... 5554 ~>examples/timer.srec 5555 1 2 3 4 5 6 7 8 9 10 11 ... 5556 [file transfer complete] 5557 [connected] 5558 ## Start Addr = 0x00040004 5559 5560 => go 40004 5561 ## Starting application at 0x00040004 ... 5562 TIMERS=0xfff00980 5563 Using timer 1 5564 tgcr @ 0xfff00980, tmr @ 0xfff00990, trr @ 0xfff00994, tcr @ 0xfff00998, tcn @ 0xfff0099c, ter @ 0xfff009b0 5565 5566Hit 'b': 5567 [q, b, e, ?] Set interval 1000000 us 5568 Enabling timer 5569Hit '?': 5570 [q, b, e, ?] ........ 5571 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0xef6, ter=0x0 5572Hit '?': 5573 [q, b, e, ?] . 5574 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x2ad4, ter=0x0 5575Hit '?': 5576 [q, b, e, ?] . 5577 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x1efc, ter=0x0 5578Hit '?': 5579 [q, b, e, ?] . 5580 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x169d, ter=0x0 5581Hit 'e': 5582 [q, b, e, ?] ...Stopping timer 5583Hit 'q': 5584 [q, b, e, ?] ## Application terminated, rc = 0x0 5585 5586 5587Minicom warning: 5588================ 5589 5590Over time, many people have reported problems when trying to use the 5591"minicom" terminal emulation program for serial download. I (wd) 5592consider minicom to be broken, and recommend not to use it. Under 5593Unix, I recommend to use C-Kermit for general purpose use (and 5594especially for kermit binary protocol download ("loadb" command), and 5595use "cu" for S-Record download ("loads" command). See 5596http://www.denx.de/wiki/view/DULG/SystemSetup#Section_4.3. 5597for help with kermit. 5598 5599 5600Nevertheless, if you absolutely want to use it try adding this 5601configuration to your "File transfer protocols" section: 5602 5603 Name Program Name U/D FullScr IO-Red. Multi 5604 X kermit /usr/bin/kermit -i -l %l -s Y U Y N N 5605 Y kermit /usr/bin/kermit -i -l %l -r N D Y N N 5606 5607 5608NetBSD Notes: 5609============= 5610 5611Starting at version 0.9.2, U-Boot supports NetBSD both as host 5612(build U-Boot) and target system (boots NetBSD/mpc8xx). 5613 5614Building requires a cross environment; it is known to work on 5615NetBSD/i386 with the cross-powerpc-netbsd-1.3 package (you will also 5616need gmake since the Makefiles are not compatible with BSD make). 5617Note that the cross-powerpc package does not install include files; 5618attempting to build U-Boot will fail because <machine/ansi.h> is 5619missing. This file has to be installed and patched manually: 5620 5621 # cd /usr/pkg/cross/powerpc-netbsd/include 5622 # mkdir powerpc 5623 # ln -s powerpc machine 5624 # cp /usr/src/sys/arch/powerpc/include/ansi.h powerpc/ansi.h 5625 # ${EDIT} powerpc/ansi.h ## must remove __va_list, _BSD_VA_LIST 5626 5627Native builds *don't* work due to incompatibilities between native 5628and U-Boot include files. 5629 5630Booting assumes that (the first part of) the image booted is a 5631stage-2 loader which in turn loads and then invokes the kernel 5632proper. Loader sources will eventually appear in the NetBSD source 5633tree (probably in sys/arc/mpc8xx/stand/u-boot_stage2/); in the 5634meantime, see ftp://ftp.denx.de/pub/u-boot/ppcboot_stage2.tar.gz 5635 5636 5637Implementation Internals: 5638========================= 5639 5640The following is not intended to be a complete description of every 5641implementation detail. However, it should help to understand the 5642inner workings of U-Boot and make it easier to port it to custom 5643hardware. 5644 5645 5646Initial Stack, Global Data: 5647--------------------------- 5648 5649The implementation of U-Boot is complicated by the fact that U-Boot 5650starts running out of ROM (flash memory), usually without access to 5651system RAM (because the memory controller is not initialized yet). 5652This means that we don't have writable Data or BSS segments, and BSS 5653is not initialized as zero. To be able to get a C environment working 5654at all, we have to allocate at least a minimal stack. Implementation 5655options for this are defined and restricted by the CPU used: Some CPU 5656models provide on-chip memory (like the IMMR area on MPC8xx and 5657MPC826x processors), on others (parts of) the data cache can be 5658locked as (mis-) used as memory, etc. 5659 5660 Chris Hallinan posted a good summary of these issues to the 5661 U-Boot mailing list: 5662 5663 Subject: RE: [U-Boot-Users] RE: More On Memory Bank x (nothingness)? 5664 From: "Chris Hallinan" <clh@net1plus.com> 5665 Date: Mon, 10 Feb 2003 16:43:46 -0500 (22:43 MET) 5666 ... 5667 5668 Correct me if I'm wrong, folks, but the way I understand it 5669 is this: Using DCACHE as initial RAM for Stack, etc, does not 5670 require any physical RAM backing up the cache. The cleverness 5671 is that the cache is being used as a temporary supply of 5672 necessary storage before the SDRAM controller is setup. It's 5673 beyond the scope of this list to explain the details, but you 5674 can see how this works by studying the cache architecture and 5675 operation in the architecture and processor-specific manuals. 5676 5677 OCM is On Chip Memory, which I believe the 405GP has 4K. It 5678 is another option for the system designer to use as an 5679 initial stack/RAM area prior to SDRAM being available. Either 5680 option should work for you. Using CS 4 should be fine if your 5681 board designers haven't used it for something that would 5682 cause you grief during the initial boot! It is frequently not 5683 used. 5684 5685 CONFIG_SYS_INIT_RAM_ADDR should be somewhere that won't interfere 5686 with your processor/board/system design. The default value 5687 you will find in any recent u-boot distribution in 5688 walnut.h should work for you. I'd set it to a value larger 5689 than your SDRAM module. If you have a 64MB SDRAM module, set 5690 it above 400_0000. Just make sure your board has no resources 5691 that are supposed to respond to that address! That code in 5692 start.S has been around a while and should work as is when 5693 you get the config right. 5694 5695 -Chris Hallinan 5696 DS4.COM, Inc. 5697 5698It is essential to remember this, since it has some impact on the C 5699code for the initialization procedures: 5700 5701* Initialized global data (data segment) is read-only. Do not attempt 5702 to write it. 5703 5704* Do not use any uninitialized global data (or implicitly initialized 5705 as zero data - BSS segment) at all - this is undefined, initiali- 5706 zation is performed later (when relocating to RAM). 5707 5708* Stack space is very limited. Avoid big data buffers or things like 5709 that. 5710 5711Having only the stack as writable memory limits means we cannot use 5712normal global data to share information between the code. But it 5713turned out that the implementation of U-Boot can be greatly 5714simplified by making a global data structure (gd_t) available to all 5715functions. We could pass a pointer to this data as argument to _all_ 5716functions, but this would bloat the code. Instead we use a feature of 5717the GCC compiler (Global Register Variables) to share the data: we 5718place a pointer (gd) to the global data into a register which we 5719reserve for this purpose. 5720 5721When choosing a register for such a purpose we are restricted by the 5722relevant (E)ABI specifications for the current architecture, and by 5723GCC's implementation. 5724 5725For PowerPC, the following registers have specific use: 5726 R1: stack pointer 5727 R2: reserved for system use 5728 R3-R4: parameter passing and return values 5729 R5-R10: parameter passing 5730 R13: small data area pointer 5731 R30: GOT pointer 5732 R31: frame pointer 5733 5734 (U-Boot also uses R12 as internal GOT pointer. r12 5735 is a volatile register so r12 needs to be reset when 5736 going back and forth between asm and C) 5737 5738 ==> U-Boot will use R2 to hold a pointer to the global data 5739 5740 Note: on PPC, we could use a static initializer (since the 5741 address of the global data structure is known at compile time), 5742 but it turned out that reserving a register results in somewhat 5743 smaller code - although the code savings are not that big (on 5744 average for all boards 752 bytes for the whole U-Boot image, 5745 624 text + 127 data). 5746 5747On ARM, the following registers are used: 5748 5749 R0: function argument word/integer result 5750 R1-R3: function argument word 5751 R9: platform specific 5752 R10: stack limit (used only if stack checking is enabled) 5753 R11: argument (frame) pointer 5754 R12: temporary workspace 5755 R13: stack pointer 5756 R14: link register 5757 R15: program counter 5758 5759 ==> U-Boot will use R9 to hold a pointer to the global data 5760 5761 Note: on ARM, only R_ARM_RELATIVE relocations are supported. 5762 5763On Nios II, the ABI is documented here: 5764 http://www.altera.com/literature/hb/nios2/n2cpu_nii51016.pdf 5765 5766 ==> U-Boot will use gp to hold a pointer to the global data 5767 5768 Note: on Nios II, we give "-G0" option to gcc and don't use gp 5769 to access small data sections, so gp is free. 5770 5771On NDS32, the following registers are used: 5772 5773 R0-R1: argument/return 5774 R2-R5: argument 5775 R15: temporary register for assembler 5776 R16: trampoline register 5777 R28: frame pointer (FP) 5778 R29: global pointer (GP) 5779 R30: link register (LP) 5780 R31: stack pointer (SP) 5781 PC: program counter (PC) 5782 5783 ==> U-Boot will use R10 to hold a pointer to the global data 5784 5785NOTE: DECLARE_GLOBAL_DATA_PTR must be used with file-global scope, 5786or current versions of GCC may "optimize" the code too much. 5787 5788Memory Management: 5789------------------ 5790 5791U-Boot runs in system state and uses physical addresses, i.e. the 5792MMU is not used either for address mapping nor for memory protection. 5793 5794The available memory is mapped to fixed addresses using the memory 5795controller. In this process, a contiguous block is formed for each 5796memory type (Flash, SDRAM, SRAM), even when it consists of several 5797physical memory banks. 5798 5799U-Boot is installed in the first 128 kB of the first Flash bank (on 5800TQM8xxL modules this is the range 0x40000000 ... 0x4001FFFF). After 5801booting and sizing and initializing DRAM, the code relocates itself 5802to the upper end of DRAM. Immediately below the U-Boot code some 5803memory is reserved for use by malloc() [see CONFIG_SYS_MALLOC_LEN 5804configuration setting]. Below that, a structure with global Board 5805Info data is placed, followed by the stack (growing downward). 5806 5807Additionally, some exception handler code is copied to the low 8 kB 5808of DRAM (0x00000000 ... 0x00001FFF). 5809 5810So a typical memory configuration with 16 MB of DRAM could look like 5811this: 5812 5813 0x0000 0000 Exception Vector code 5814 : 5815 0x0000 1FFF 5816 0x0000 2000 Free for Application Use 5817 : 5818 : 5819 5820 : 5821 : 5822 0x00FB FF20 Monitor Stack (Growing downward) 5823 0x00FB FFAC Board Info Data and permanent copy of global data 5824 0x00FC 0000 Malloc Arena 5825 : 5826 0x00FD FFFF 5827 0x00FE 0000 RAM Copy of Monitor Code 5828 ... eventually: LCD or video framebuffer 5829 ... eventually: pRAM (Protected RAM - unchanged by reset) 5830 0x00FF FFFF [End of RAM] 5831 5832 5833System Initialization: 5834---------------------- 5835 5836In the reset configuration, U-Boot starts at the reset entry point 5837(on most PowerPC systems at address 0x00000100). Because of the reset 5838configuration for CS0# this is a mirror of the on board Flash memory. 5839To be able to re-map memory U-Boot then jumps to its link address. 5840To be able to implement the initialization code in C, a (small!) 5841initial stack is set up in the internal Dual Ported RAM (in case CPUs 5842which provide such a feature like MPC8xx or MPC8260), or in a locked 5843part of the data cache. After that, U-Boot initializes the CPU core, 5844the caches and the SIU. 5845 5846Next, all (potentially) available memory banks are mapped using a 5847preliminary mapping. For example, we put them on 512 MB boundaries 5848(multiples of 0x20000000: SDRAM on 0x00000000 and 0x20000000, Flash 5849on 0x40000000 and 0x60000000, SRAM on 0x80000000). Then UPM A is 5850programmed for SDRAM access. Using the temporary configuration, a 5851simple memory test is run that determines the size of the SDRAM 5852banks. 5853 5854When there is more than one SDRAM bank, and the banks are of 5855different size, the largest is mapped first. For equal size, the first 5856bank (CS2#) is mapped first. The first mapping is always for address 58570x00000000, with any additional banks following immediately to create 5858contiguous memory starting from 0. 5859 5860Then, the monitor installs itself at the upper end of the SDRAM area 5861and allocates memory for use by malloc() and for the global Board 5862Info data; also, the exception vector code is copied to the low RAM 5863pages, and the final stack is set up. 5864 5865Only after this relocation will you have a "normal" C environment; 5866until that you are restricted in several ways, mostly because you are 5867running from ROM, and because the code will have to be relocated to a 5868new address in RAM. 5869 5870 5871U-Boot Porting Guide: 5872---------------------- 5873 5874[Based on messages by Jerry Van Baren in the U-Boot-Users mailing 5875list, October 2002] 5876 5877 5878int main(int argc, char *argv[]) 5879{ 5880 sighandler_t no_more_time; 5881 5882 signal(SIGALRM, no_more_time); 5883 alarm(PROJECT_DEADLINE - toSec (3 * WEEK)); 5884 5885 if (available_money > available_manpower) { 5886 Pay consultant to port U-Boot; 5887 return 0; 5888 } 5889 5890 Download latest U-Boot source; 5891 5892 Subscribe to u-boot mailing list; 5893 5894 if (clueless) 5895 email("Hi, I am new to U-Boot, how do I get started?"); 5896 5897 while (learning) { 5898 Read the README file in the top level directory; 5899 Read http://www.denx.de/twiki/bin/view/DULG/Manual; 5900 Read applicable doc/*.README; 5901 Read the source, Luke; 5902 /* find . -name "*.[chS]" | xargs grep -i <keyword> */ 5903 } 5904 5905 if (available_money > toLocalCurrency ($2500)) 5906 Buy a BDI3000; 5907 else 5908 Add a lot of aggravation and time; 5909 5910 if (a similar board exists) { /* hopefully... */ 5911 cp -a board/<similar> board/<myboard> 5912 cp include/configs/<similar>.h include/configs/<myboard>.h 5913 } else { 5914 Create your own board support subdirectory; 5915 Create your own board include/configs/<myboard>.h file; 5916 } 5917 Edit new board/<myboard> files 5918 Edit new include/configs/<myboard>.h 5919 5920 while (!accepted) { 5921 while (!running) { 5922 do { 5923 Add / modify source code; 5924 } until (compiles); 5925 Debug; 5926 if (clueless) 5927 email("Hi, I am having problems..."); 5928 } 5929 Send patch file to the U-Boot email list; 5930 if (reasonable critiques) 5931 Incorporate improvements from email list code review; 5932 else 5933 Defend code as written; 5934 } 5935 5936 return 0; 5937} 5938 5939void no_more_time (int sig) 5940{ 5941 hire_a_guru(); 5942} 5943 5944 5945Coding Standards: 5946----------------- 5947 5948All contributions to U-Boot should conform to the Linux kernel 5949coding style; see the file "Documentation/CodingStyle" and the script 5950"scripts/Lindent" in your Linux kernel source directory. 5951 5952Source files originating from a different project (for example the 5953MTD subsystem) are generally exempt from these guidelines and are not 5954reformatted to ease subsequent migration to newer versions of those 5955sources. 5956 5957Please note that U-Boot is implemented in C (and to some small parts in 5958Assembler); no C++ is used, so please do not use C++ style comments (//) 5959in your code. 5960 5961Please also stick to the following formatting rules: 5962- remove any trailing white space 5963- use TAB characters for indentation and vertical alignment, not spaces 5964- make sure NOT to use DOS '\r\n' line feeds 5965- do not add more than 2 consecutive empty lines to source files 5966- do not add trailing empty lines to source files 5967 5968Submissions which do not conform to the standards may be returned 5969with a request to reformat the changes. 5970 5971 5972Submitting Patches: 5973------------------- 5974 5975Since the number of patches for U-Boot is growing, we need to 5976establish some rules. Submissions which do not conform to these rules 5977may be rejected, even when they contain important and valuable stuff. 5978 5979Please see http://www.denx.de/wiki/U-Boot/Patches for details. 5980 5981Patches shall be sent to the u-boot mailing list <u-boot@lists.denx.de>; 5982see http://lists.denx.de/mailman/listinfo/u-boot 5983 5984When you send a patch, please include the following information with 5985it: 5986 5987* For bug fixes: a description of the bug and how your patch fixes 5988 this bug. Please try to include a way of demonstrating that the 5989 patch actually fixes something. 5990 5991* For new features: a description of the feature and your 5992 implementation. 5993 5994* A CHANGELOG entry as plaintext (separate from the patch) 5995 5996* For major contributions, add a MAINTAINERS file with your 5997 information and associated file and directory references. 5998 5999* When you add support for a new board, don't forget to add a 6000 maintainer e-mail address to the boards.cfg file, too. 6001 6002* If your patch adds new configuration options, don't forget to 6003 document these in the README file. 6004 6005* The patch itself. If you are using git (which is *strongly* 6006 recommended) you can easily generate the patch using the 6007 "git format-patch". If you then use "git send-email" to send it to 6008 the U-Boot mailing list, you will avoid most of the common problems 6009 with some other mail clients. 6010 6011 If you cannot use git, use "diff -purN OLD NEW". If your version of 6012 diff does not support these options, then get the latest version of 6013 GNU diff. 6014 6015 The current directory when running this command shall be the parent 6016 directory of the U-Boot source tree (i. e. please make sure that 6017 your patch includes sufficient directory information for the 6018 affected files). 6019 6020 We prefer patches as plain text. MIME attachments are discouraged, 6021 and compressed attachments must not be used. 6022 6023* If one logical set of modifications affects or creates several 6024 files, all these changes shall be submitted in a SINGLE patch file. 6025 6026* Changesets that contain different, unrelated modifications shall be 6027 submitted as SEPARATE patches, one patch per changeset. 6028 6029 6030Notes: 6031 6032* Before sending the patch, run the buildman script on your patched 6033 source tree and make sure that no errors or warnings are reported 6034 for any of the boards. 6035 6036* Keep your modifications to the necessary minimum: A patch 6037 containing several unrelated changes or arbitrary reformats will be 6038 returned with a request to re-formatting / split it. 6039 6040* If you modify existing code, make sure that your new code does not 6041 add to the memory footprint of the code ;-) Small is beautiful! 6042 When adding new features, these should compile conditionally only 6043 (using #ifdef), and the resulting code with the new feature 6044 disabled must not need more memory than the old code without your 6045 modification. 6046 6047* Remember that there is a size limit of 100 kB per message on the 6048 u-boot mailing list. Bigger patches will be moderated. If they are 6049 reasonable and not too big, they will be acknowledged. But patches 6050 bigger than the size limit should be avoided. 6051