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_DHCP * DHCP support 831 CONFIG_CMD_DIAG * Diagnostics 832 CONFIG_CMD_ECHO echo arguments 833 CONFIG_CMD_EDITENV edit env variable 834 CONFIG_CMD_ELF * bootelf, bootvx 835 CONFIG_CMD_ENV_EXISTS * check existence of env variable 836 CONFIG_CMD_EXPORTENV * export the environment 837 CONFIG_CMD_EXT2 * ext2 command support 838 CONFIG_CMD_EXT4 * ext4 command support 839 CONFIG_CMD_FS_GENERIC * filesystem commands (e.g. load, ls) 840 that work for multiple fs types 841 CONFIG_CMD_FS_UUID * Look up a filesystem UUID 842 CONFIG_CMD_SAVEENV saveenv 843 CONFIG_CMD_FLASH flinfo, erase, protect 844 CONFIG_CMD_FPGA FPGA device initialization support 845 CONFIG_CMD_GO * the 'go' command (exec code) 846 CONFIG_CMD_GREPENV * search environment 847 CONFIG_CMD_I2C * I2C serial bus support 848 CONFIG_CMD_IMI iminfo 849 CONFIG_CMD_IMLS List all images found in NOR flash 850 CONFIG_CMD_IMLS_NAND * List all images found in NAND flash 851 CONFIG_CMD_IMPORTENV * import an environment 852 CONFIG_CMD_INI * import data from an ini file into the env 853 CONFIG_CMD_ITEST Integer/string test of 2 values 854 CONFIG_CMD_LDRINFO * ldrinfo (display Blackfin loader) 855 CONFIG_CMD_LINK_LOCAL * link-local IP address auto-configuration 856 (169.254.*.*) 857 CONFIG_CMD_LOADB loadb 858 CONFIG_CMD_LOADS loads 859 CONFIG_CMD_MD5SUM * print md5 message digest 860 (requires CONFIG_CMD_MEMORY and CONFIG_MD5) 861 CONFIG_CMD_MEMINFO * Display detailed memory information 862 CONFIG_CMD_MEMORY md, mm, nm, mw, cp, cmp, crc, base, 863 loop, loopw 864 CONFIG_CMD_MEMTEST * mtest 865 CONFIG_CMD_MISC Misc functions like sleep etc 866 CONFIG_CMD_MMC * MMC memory mapped support 867 CONFIG_CMD_MII * MII utility commands 868 CONFIG_CMD_MTDPARTS * MTD partition support 869 CONFIG_CMD_NAND * NAND support 870 CONFIG_CMD_NET bootp, tftpboot, rarpboot 871 CONFIG_CMD_NFS NFS support 872 CONFIG_CMD_PCA953X * PCA953x I2C gpio commands 873 CONFIG_CMD_PCA953X_INFO * PCA953x I2C gpio info command 874 CONFIG_CMD_PCI * pciinfo 875 CONFIG_CMD_PCMCIA * PCMCIA support 876 CONFIG_CMD_PING * send ICMP ECHO_REQUEST to network 877 host 878 CONFIG_CMD_PORTIO * Port I/O 879 CONFIG_CMD_READ * Read raw data from partition 880 CONFIG_CMD_REGINFO * Register dump 881 CONFIG_CMD_RUN run command in env variable 882 CONFIG_CMD_SANDBOX * sb command to access sandbox features 883 CONFIG_CMD_SAVES * save S record dump 884 CONFIG_SCSI * SCSI Support 885 CONFIG_CMD_SDRAM * print SDRAM configuration information 886 (requires CONFIG_CMD_I2C) 887 CONFIG_CMD_SETGETDCR Support for DCR Register access 888 (4xx only) 889 CONFIG_CMD_SF * Read/write/erase SPI NOR flash 890 CONFIG_CMD_SOFTSWITCH * Soft switch setting command for BF60x 891 CONFIG_CMD_SOURCE "source" command Support 892 CONFIG_CMD_SPI * SPI serial bus support 893 CONFIG_CMD_TFTPSRV * TFTP transfer in server mode 894 CONFIG_CMD_TFTPPUT * TFTP put command (upload) 895 CONFIG_CMD_TIME * run command and report execution time (ARM specific) 896 CONFIG_CMD_TIMER * access to the system tick timer 897 CONFIG_CMD_USB * USB support 898 CONFIG_CMD_CDP * Cisco Discover Protocol support 899 CONFIG_CMD_MFSL * Microblaze FSL support 900 CONFIG_CMD_XIMG Load part of Multi Image 901 CONFIG_CMD_UUID * Generate random UUID or GUID string 902 903 EXAMPLE: If you want all functions except of network 904 support you can write: 905 906 #include "config_cmd_all.h" 907 #undef CONFIG_CMD_NET 908 909 Other Commands: 910 fdt (flattened device tree) command: CONFIG_OF_LIBFDT 911 912 Note: Don't enable the "icache" and "dcache" commands 913 (configuration option CONFIG_CMD_CACHE) unless you know 914 what you (and your U-Boot users) are doing. Data 915 cache cannot be enabled on systems like the 8xx or 916 8260 (where accesses to the IMMR region must be 917 uncached), and it cannot be disabled on all other 918 systems where we (mis-) use the data cache to hold an 919 initial stack and some data. 920 921 922 XXX - this list needs to get updated! 923 924- Removal of commands 925 If no commands are needed to boot, you can disable 926 CONFIG_CMDLINE to remove them. In this case, the command line 927 will not be available, and when U-Boot wants to execute the 928 boot command (on start-up) it will call board_run_command() 929 instead. This can reduce image size significantly for very 930 simple boot procedures. 931 932- Regular expression support: 933 CONFIG_REGEX 934 If this variable is defined, U-Boot is linked against 935 the SLRE (Super Light Regular Expression) library, 936 which adds regex support to some commands, as for 937 example "env grep" and "setexpr". 938 939- Device tree: 940 CONFIG_OF_CONTROL 941 If this variable is defined, U-Boot will use a device tree 942 to configure its devices, instead of relying on statically 943 compiled #defines in the board file. This option is 944 experimental and only available on a few boards. The device 945 tree is available in the global data as gd->fdt_blob. 946 947 U-Boot needs to get its device tree from somewhere. This can 948 be done using one of the three options below: 949 950 CONFIG_OF_EMBED 951 If this variable is defined, U-Boot will embed a device tree 952 binary in its image. This device tree file should be in the 953 board directory and called <soc>-<board>.dts. The binary file 954 is then picked up in board_init_f() and made available through 955 the global data structure as gd->blob. 956 957 CONFIG_OF_SEPARATE 958 If this variable is defined, U-Boot will build a device tree 959 binary. It will be called u-boot.dtb. Architecture-specific 960 code will locate it at run-time. Generally this works by: 961 962 cat u-boot.bin u-boot.dtb >image.bin 963 964 and in fact, U-Boot does this for you, creating a file called 965 u-boot-dtb.bin which is useful in the common case. You can 966 still use the individual files if you need something more 967 exotic. 968 969 CONFIG_OF_BOARD 970 If this variable is defined, U-Boot will use the device tree 971 provided by the board at runtime instead of embedding one with 972 the image. Only boards defining board_fdt_blob_setup() support 973 this option (see include/fdtdec.h file). 974 975- Watchdog: 976 CONFIG_WATCHDOG 977 If this variable is defined, it enables watchdog 978 support for the SoC. There must be support in the SoC 979 specific code for a watchdog. For the 8xx and 8260 980 CPUs, the SIU Watchdog feature is enabled in the SYPCR 981 register. When supported for a specific SoC is 982 available, then no further board specific code should 983 be needed to use it. 984 985 CONFIG_HW_WATCHDOG 986 When using a watchdog circuitry external to the used 987 SoC, then define this variable and provide board 988 specific code for the "hw_watchdog_reset" function. 989 990 CONFIG_AT91_HW_WDT_TIMEOUT 991 specify the timeout in seconds. default 2 seconds. 992 993- U-Boot Version: 994 CONFIG_VERSION_VARIABLE 995 If this variable is defined, an environment variable 996 named "ver" is created by U-Boot showing the U-Boot 997 version as printed by the "version" command. 998 Any change to this variable will be reverted at the 999 next reset. 1000 1001- Real-Time Clock: 1002 1003 When CONFIG_CMD_DATE is selected, the type of the RTC 1004 has to be selected, too. Define exactly one of the 1005 following options: 1006 1007 CONFIG_RTC_MPC8xx - use internal RTC of MPC8xx 1008 CONFIG_RTC_PCF8563 - use Philips PCF8563 RTC 1009 CONFIG_RTC_MC13XXX - use MC13783 or MC13892 RTC 1010 CONFIG_RTC_MC146818 - use MC146818 RTC 1011 CONFIG_RTC_DS1307 - use Maxim, Inc. DS1307 RTC 1012 CONFIG_RTC_DS1337 - use Maxim, Inc. DS1337 RTC 1013 CONFIG_RTC_DS1338 - use Maxim, Inc. DS1338 RTC 1014 CONFIG_RTC_DS1339 - use Maxim, Inc. DS1339 RTC 1015 CONFIG_RTC_DS164x - use Dallas DS164x RTC 1016 CONFIG_RTC_ISL1208 - use Intersil ISL1208 RTC 1017 CONFIG_RTC_MAX6900 - use Maxim, Inc. MAX6900 RTC 1018 CONFIG_RTC_DS1337_NOOSC - Turn off the OSC output for DS1337 1019 CONFIG_SYS_RV3029_TCR - enable trickle charger on 1020 RV3029 RTC. 1021 1022 Note that if the RTC uses I2C, then the I2C interface 1023 must also be configured. See I2C Support, below. 1024 1025- GPIO Support: 1026 CONFIG_PCA953X - use NXP's PCA953X series I2C GPIO 1027 1028 The CONFIG_SYS_I2C_PCA953X_WIDTH option specifies a list of 1029 chip-ngpio pairs that tell the PCA953X driver the number of 1030 pins supported by a particular chip. 1031 1032 Note that if the GPIO device uses I2C, then the I2C interface 1033 must also be configured. See I2C Support, below. 1034 1035- I/O tracing: 1036 When CONFIG_IO_TRACE is selected, U-Boot intercepts all I/O 1037 accesses and can checksum them or write a list of them out 1038 to memory. See the 'iotrace' command for details. This is 1039 useful for testing device drivers since it can confirm that 1040 the driver behaves the same way before and after a code 1041 change. Currently this is supported on sandbox and arm. To 1042 add support for your architecture, add '#include <iotrace.h>' 1043 to the bottom of arch/<arch>/include/asm/io.h and test. 1044 1045 Example output from the 'iotrace stats' command is below. 1046 Note that if the trace buffer is exhausted, the checksum will 1047 still continue to operate. 1048 1049 iotrace is enabled 1050 Start: 10000000 (buffer start address) 1051 Size: 00010000 (buffer size) 1052 Offset: 00000120 (current buffer offset) 1053 Output: 10000120 (start + offset) 1054 Count: 00000018 (number of trace records) 1055 CRC32: 9526fb66 (CRC32 of all trace records) 1056 1057- Timestamp Support: 1058 1059 When CONFIG_TIMESTAMP is selected, the timestamp 1060 (date and time) of an image is printed by image 1061 commands like bootm or iminfo. This option is 1062 automatically enabled when you select CONFIG_CMD_DATE . 1063 1064- Partition Labels (disklabels) Supported: 1065 Zero or more of the following: 1066 CONFIG_MAC_PARTITION Apple's MacOS partition table. 1067 CONFIG_ISO_PARTITION ISO partition table, used on CDROM etc. 1068 CONFIG_EFI_PARTITION GPT partition table, common when EFI is the 1069 bootloader. Note 2TB partition limit; see 1070 disk/part_efi.c 1071 CONFIG_MTD_PARTITIONS Memory Technology Device partition table. 1072 1073 If IDE or SCSI support is enabled (CONFIG_IDE or 1074 CONFIG_SCSI) you must configure support for at 1075 least one non-MTD partition type as well. 1076 1077- IDE Reset method: 1078 CONFIG_IDE_RESET_ROUTINE - this is defined in several 1079 board configurations files but used nowhere! 1080 1081 CONFIG_IDE_RESET - is this is defined, IDE Reset will 1082 be performed by calling the function 1083 ide_set_reset(int reset) 1084 which has to be defined in a board specific file 1085 1086- ATAPI Support: 1087 CONFIG_ATAPI 1088 1089 Set this to enable ATAPI support. 1090 1091- LBA48 Support 1092 CONFIG_LBA48 1093 1094 Set this to enable support for disks larger than 137GB 1095 Also look at CONFIG_SYS_64BIT_LBA. 1096 Whithout these , LBA48 support uses 32bit variables and will 'only' 1097 support disks up to 2.1TB. 1098 1099 CONFIG_SYS_64BIT_LBA: 1100 When enabled, makes the IDE subsystem use 64bit sector addresses. 1101 Default is 32bit. 1102 1103- SCSI Support: 1104 At the moment only there is only support for the 1105 SYM53C8XX SCSI controller; define 1106 CONFIG_SCSI_SYM53C8XX to enable it. 1107 1108 CONFIG_SYS_SCSI_MAX_LUN [8], CONFIG_SYS_SCSI_MAX_SCSI_ID [7] and 1109 CONFIG_SYS_SCSI_MAX_DEVICE [CONFIG_SYS_SCSI_MAX_SCSI_ID * 1110 CONFIG_SYS_SCSI_MAX_LUN] can be adjusted to define the 1111 maximum numbers of LUNs, SCSI ID's and target 1112 devices. 1113 CONFIG_SYS_SCSI_SYM53C8XX_CCF to fix clock timing (80Mhz) 1114 1115 The environment variable 'scsidevs' is set to the number of 1116 SCSI devices found during the last scan. 1117 1118- NETWORK Support (PCI): 1119 CONFIG_E1000 1120 Support for Intel 8254x/8257x gigabit chips. 1121 1122 CONFIG_E1000_SPI 1123 Utility code for direct access to the SPI bus on Intel 8257x. 1124 This does not do anything useful unless you set at least one 1125 of CONFIG_CMD_E1000 or CONFIG_E1000_SPI_GENERIC. 1126 1127 CONFIG_E1000_SPI_GENERIC 1128 Allow generic access to the SPI bus on the Intel 8257x, for 1129 example with the "sspi" command. 1130 1131 CONFIG_CMD_E1000 1132 Management command for E1000 devices. When used on devices 1133 with SPI support you can reprogram the EEPROM from U-Boot. 1134 1135 CONFIG_EEPRO100 1136 Support for Intel 82557/82559/82559ER chips. 1137 Optional CONFIG_EEPRO100_SROM_WRITE enables EEPROM 1138 write routine for first time initialisation. 1139 1140 CONFIG_TULIP 1141 Support for Digital 2114x chips. 1142 Optional CONFIG_TULIP_SELECT_MEDIA for board specific 1143 modem chip initialisation (KS8761/QS6611). 1144 1145 CONFIG_NATSEMI 1146 Support for National dp83815 chips. 1147 1148 CONFIG_NS8382X 1149 Support for National dp8382[01] gigabit chips. 1150 1151- NETWORK Support (other): 1152 1153 CONFIG_DRIVER_AT91EMAC 1154 Support for AT91RM9200 EMAC. 1155 1156 CONFIG_RMII 1157 Define this to use reduced MII inteface 1158 1159 CONFIG_DRIVER_AT91EMAC_QUIET 1160 If this defined, the driver is quiet. 1161 The driver doen't show link status messages. 1162 1163 CONFIG_CALXEDA_XGMAC 1164 Support for the Calxeda XGMAC device 1165 1166 CONFIG_LAN91C96 1167 Support for SMSC's LAN91C96 chips. 1168 1169 CONFIG_LAN91C96_USE_32_BIT 1170 Define this to enable 32 bit addressing 1171 1172 CONFIG_SMC91111 1173 Support for SMSC's LAN91C111 chip 1174 1175 CONFIG_SMC91111_BASE 1176 Define this to hold the physical address 1177 of the device (I/O space) 1178 1179 CONFIG_SMC_USE_32_BIT 1180 Define this if data bus is 32 bits 1181 1182 CONFIG_SMC_USE_IOFUNCS 1183 Define this to use i/o functions instead of macros 1184 (some hardware wont work with macros) 1185 1186 CONFIG_DRIVER_TI_EMAC 1187 Support for davinci emac 1188 1189 CONFIG_SYS_DAVINCI_EMAC_PHY_COUNT 1190 Define this if you have more then 3 PHYs. 1191 1192 CONFIG_FTGMAC100 1193 Support for Faraday's FTGMAC100 Gigabit SoC Ethernet 1194 1195 CONFIG_FTGMAC100_EGIGA 1196 Define this to use GE link update with gigabit PHY. 1197 Define this if FTGMAC100 is connected to gigabit PHY. 1198 If your system has 10/100 PHY only, it might not occur 1199 wrong behavior. Because PHY usually return timeout or 1200 useless data when polling gigabit status and gigabit 1201 control registers. This behavior won't affect the 1202 correctnessof 10/100 link speed update. 1203 1204 CONFIG_SMC911X 1205 Support for SMSC's LAN911x and LAN921x chips 1206 1207 CONFIG_SMC911X_BASE 1208 Define this to hold the physical address 1209 of the device (I/O space) 1210 1211 CONFIG_SMC911X_32_BIT 1212 Define this if data bus is 32 bits 1213 1214 CONFIG_SMC911X_16_BIT 1215 Define this if data bus is 16 bits. If your processor 1216 automatically converts one 32 bit word to two 16 bit 1217 words you may also try CONFIG_SMC911X_32_BIT. 1218 1219 CONFIG_SH_ETHER 1220 Support for Renesas on-chip Ethernet controller 1221 1222 CONFIG_SH_ETHER_USE_PORT 1223 Define the number of ports to be used 1224 1225 CONFIG_SH_ETHER_PHY_ADDR 1226 Define the ETH PHY's address 1227 1228 CONFIG_SH_ETHER_CACHE_WRITEBACK 1229 If this option is set, the driver enables cache flush. 1230 1231- PWM Support: 1232 CONFIG_PWM_IMX 1233 Support for PWM module on the imx6. 1234 1235- TPM Support: 1236 CONFIG_TPM 1237 Support TPM devices. 1238 1239 CONFIG_TPM_TIS_INFINEON 1240 Support for Infineon i2c bus TPM devices. Only one device 1241 per system is supported at this time. 1242 1243 CONFIG_TPM_TIS_I2C_BURST_LIMITATION 1244 Define the burst count bytes upper limit 1245 1246 CONFIG_TPM_ST33ZP24 1247 Support for STMicroelectronics TPM devices. Requires DM_TPM support. 1248 1249 CONFIG_TPM_ST33ZP24_I2C 1250 Support for STMicroelectronics ST33ZP24 I2C devices. 1251 Requires TPM_ST33ZP24 and I2C. 1252 1253 CONFIG_TPM_ST33ZP24_SPI 1254 Support for STMicroelectronics ST33ZP24 SPI devices. 1255 Requires TPM_ST33ZP24 and SPI. 1256 1257 CONFIG_TPM_ATMEL_TWI 1258 Support for Atmel TWI TPM device. Requires I2C support. 1259 1260 CONFIG_TPM_TIS_LPC 1261 Support for generic parallel port TPM devices. Only one device 1262 per system is supported at this time. 1263 1264 CONFIG_TPM_TIS_BASE_ADDRESS 1265 Base address where the generic TPM device is mapped 1266 to. Contemporary x86 systems usually map it at 1267 0xfed40000. 1268 1269 CONFIG_CMD_TPM 1270 Add tpm monitor functions. 1271 Requires CONFIG_TPM. If CONFIG_TPM_AUTH_SESSIONS is set, also 1272 provides monitor access to authorized functions. 1273 1274 CONFIG_TPM 1275 Define this to enable the TPM support library which provides 1276 functional interfaces to some TPM commands. 1277 Requires support for a TPM device. 1278 1279 CONFIG_TPM_AUTH_SESSIONS 1280 Define this to enable authorized functions in the TPM library. 1281 Requires CONFIG_TPM and CONFIG_SHA1. 1282 1283- USB Support: 1284 At the moment only the UHCI host controller is 1285 supported (PIP405, MIP405, MPC5200); define 1286 CONFIG_USB_UHCI to enable it. 1287 define CONFIG_USB_KEYBOARD to enable the USB Keyboard 1288 and define CONFIG_USB_STORAGE to enable the USB 1289 storage devices. 1290 Note: 1291 Supported are USB Keyboards and USB Floppy drives 1292 (TEAC FD-05PUB). 1293 MPC5200 USB requires additional defines: 1294 CONFIG_USB_CLOCK 1295 for 528 MHz Clock: 0x0001bbbb 1296 CONFIG_PSC3_USB 1297 for USB on PSC3 1298 CONFIG_USB_CONFIG 1299 for differential drivers: 0x00001000 1300 for single ended drivers: 0x00005000 1301 for differential drivers on PSC3: 0x00000100 1302 for single ended drivers on PSC3: 0x00004100 1303 CONFIG_SYS_USB_EVENT_POLL 1304 May be defined to allow interrupt polling 1305 instead of using asynchronous interrupts 1306 1307 CONFIG_USB_EHCI_TXFIFO_THRESH enables setting of the 1308 txfilltuning field in the EHCI controller on reset. 1309 1310 CONFIG_USB_DWC2_REG_ADDR the physical CPU address of the DWC2 1311 HW module registers. 1312 1313- USB Device: 1314 Define the below if you wish to use the USB console. 1315 Once firmware is rebuilt from a serial console issue the 1316 command "setenv stdin usbtty; setenv stdout usbtty" and 1317 attach your USB cable. The Unix command "dmesg" should print 1318 it has found a new device. The environment variable usbtty 1319 can be set to gserial or cdc_acm to enable your device to 1320 appear to a USB host as a Linux gserial device or a 1321 Common Device Class Abstract Control Model serial device. 1322 If you select usbtty = gserial you should be able to enumerate 1323 a Linux host by 1324 # modprobe usbserial vendor=0xVendorID product=0xProductID 1325 else if using cdc_acm, simply setting the environment 1326 variable usbtty to be cdc_acm should suffice. The following 1327 might be defined in YourBoardName.h 1328 1329 CONFIG_USB_DEVICE 1330 Define this to build a UDC device 1331 1332 CONFIG_USB_TTY 1333 Define this to have a tty type of device available to 1334 talk to the UDC device 1335 1336 CONFIG_USBD_HS 1337 Define this to enable the high speed support for usb 1338 device and usbtty. If this feature is enabled, a routine 1339 int is_usbd_high_speed(void) 1340 also needs to be defined by the driver to dynamically poll 1341 whether the enumeration has succeded at high speed or full 1342 speed. 1343 1344 CONFIG_SYS_CONSOLE_IS_IN_ENV 1345 Define this if you want stdin, stdout &/or stderr to 1346 be set to usbtty. 1347 1348 mpc8xx: 1349 CONFIG_SYS_USB_EXTC_CLK 0xBLAH 1350 Derive USB clock from external clock "blah" 1351 - CONFIG_SYS_USB_EXTC_CLK 0x02 1352 1353 If you have a USB-IF assigned VendorID then you may wish to 1354 define your own vendor specific values either in BoardName.h 1355 or directly in usbd_vendor_info.h. If you don't define 1356 CONFIG_USBD_MANUFACTURER, CONFIG_USBD_PRODUCT_NAME, 1357 CONFIG_USBD_VENDORID and CONFIG_USBD_PRODUCTID, then U-Boot 1358 should pretend to be a Linux device to it's target host. 1359 1360 CONFIG_USBD_MANUFACTURER 1361 Define this string as the name of your company for 1362 - CONFIG_USBD_MANUFACTURER "my company" 1363 1364 CONFIG_USBD_PRODUCT_NAME 1365 Define this string as the name of your product 1366 - CONFIG_USBD_PRODUCT_NAME "acme usb device" 1367 1368 CONFIG_USBD_VENDORID 1369 Define this as your assigned Vendor ID from the USB 1370 Implementors Forum. This *must* be a genuine Vendor ID 1371 to avoid polluting the USB namespace. 1372 - CONFIG_USBD_VENDORID 0xFFFF 1373 1374 CONFIG_USBD_PRODUCTID 1375 Define this as the unique Product ID 1376 for your device 1377 - CONFIG_USBD_PRODUCTID 0xFFFF 1378 1379- ULPI Layer Support: 1380 The ULPI (UTMI Low Pin (count) Interface) PHYs are supported via 1381 the generic ULPI layer. The generic layer accesses the ULPI PHY 1382 via the platform viewport, so you need both the genric layer and 1383 the viewport enabled. Currently only Chipidea/ARC based 1384 viewport is supported. 1385 To enable the ULPI layer support, define CONFIG_USB_ULPI and 1386 CONFIG_USB_ULPI_VIEWPORT in your board configuration file. 1387 If your ULPI phy needs a different reference clock than the 1388 standard 24 MHz then you have to define CONFIG_ULPI_REF_CLK to 1389 the appropriate value in Hz. 1390 1391- MMC Support: 1392 The MMC controller on the Intel PXA is supported. To 1393 enable this define CONFIG_MMC. The MMC can be 1394 accessed from the boot prompt by mapping the device 1395 to physical memory similar to flash. Command line is 1396 enabled with CONFIG_CMD_MMC. The MMC driver also works with 1397 the FAT fs. This is enabled with CONFIG_CMD_FAT. 1398 1399 CONFIG_SH_MMCIF 1400 Support for Renesas on-chip MMCIF controller 1401 1402 CONFIG_SH_MMCIF_ADDR 1403 Define the base address of MMCIF registers 1404 1405 CONFIG_SH_MMCIF_CLK 1406 Define the clock frequency for MMCIF 1407 1408 CONFIG_SUPPORT_EMMC_BOOT 1409 Enable some additional features of the eMMC boot partitions. 1410 1411 CONFIG_SUPPORT_EMMC_RPMB 1412 Enable the commands for reading, writing and programming the 1413 key for the Replay Protection Memory Block partition in eMMC. 1414 1415- USB Device Firmware Update (DFU) class support: 1416 CONFIG_USB_FUNCTION_DFU 1417 This enables the USB portion of the DFU USB class 1418 1419 CONFIG_CMD_DFU 1420 This enables the command "dfu" which is used to have 1421 U-Boot create a DFU class device via USB. This command 1422 requires that the "dfu_alt_info" environment variable be 1423 set and define the alt settings to expose to the host. 1424 1425 CONFIG_DFU_MMC 1426 This enables support for exposing (e)MMC devices via DFU. 1427 1428 CONFIG_DFU_NAND 1429 This enables support for exposing NAND devices via DFU. 1430 1431 CONFIG_DFU_RAM 1432 This enables support for exposing RAM via DFU. 1433 Note: DFU spec refer to non-volatile memory usage, but 1434 allow usages beyond the scope of spec - here RAM usage, 1435 one that would help mostly the developer. 1436 1437 CONFIG_SYS_DFU_DATA_BUF_SIZE 1438 Dfu transfer uses a buffer before writing data to the 1439 raw storage device. Make the size (in bytes) of this buffer 1440 configurable. The size of this buffer is also configurable 1441 through the "dfu_bufsiz" environment variable. 1442 1443 CONFIG_SYS_DFU_MAX_FILE_SIZE 1444 When updating files rather than the raw storage device, 1445 we use a static buffer to copy the file into and then write 1446 the buffer once we've been given the whole file. Define 1447 this to the maximum filesize (in bytes) for the buffer. 1448 Default is 4 MiB if undefined. 1449 1450 DFU_DEFAULT_POLL_TIMEOUT 1451 Poll timeout [ms], is the timeout a device can send to the 1452 host. The host must wait for this timeout before sending 1453 a subsequent DFU_GET_STATUS request to the device. 1454 1455 DFU_MANIFEST_POLL_TIMEOUT 1456 Poll timeout [ms], which the device sends to the host when 1457 entering dfuMANIFEST state. Host waits this timeout, before 1458 sending again an USB request to the device. 1459 1460- USB Device Android Fastboot support: 1461 CONFIG_USB_FUNCTION_FASTBOOT 1462 This enables the USB part of the fastboot gadget 1463 1464 CONFIG_CMD_FASTBOOT 1465 This enables the command "fastboot" which enables the Android 1466 fastboot mode for the platform's USB device. Fastboot is a USB 1467 protocol for downloading images, flashing and device control 1468 used on Android devices. 1469 See doc/README.android-fastboot for more information. 1470 1471 CONFIG_ANDROID_BOOT_IMAGE 1472 This enables support for booting images which use the Android 1473 image format header. 1474 1475 CONFIG_FASTBOOT_BUF_ADDR 1476 The fastboot protocol requires a large memory buffer for 1477 downloads. Define this to the starting RAM address to use for 1478 downloaded images. 1479 1480 CONFIG_FASTBOOT_BUF_SIZE 1481 The fastboot protocol requires a large memory buffer for 1482 downloads. This buffer should be as large as possible for a 1483 platform. Define this to the size available RAM for fastboot. 1484 1485 CONFIG_FASTBOOT_FLASH 1486 The fastboot protocol includes a "flash" command for writing 1487 the downloaded image to a non-volatile storage device. Define 1488 this to enable the "fastboot flash" command. 1489 1490 CONFIG_FASTBOOT_FLASH_MMC_DEV 1491 The fastboot "flash" command requires additional information 1492 regarding the non-volatile storage device. Define this to 1493 the eMMC device that fastboot should use to store the image. 1494 1495 CONFIG_FASTBOOT_GPT_NAME 1496 The fastboot "flash" command supports writing the downloaded 1497 image to the Protective MBR and the Primary GUID Partition 1498 Table. (Additionally, this downloaded image is post-processed 1499 to generate and write the Backup GUID Partition Table.) 1500 This occurs when the specified "partition name" on the 1501 "fastboot flash" command line matches this value. 1502 The default is "gpt" if undefined. 1503 1504 CONFIG_FASTBOOT_MBR_NAME 1505 The fastboot "flash" command supports writing the downloaded 1506 image to DOS MBR. 1507 This occurs when the "partition name" specified on the 1508 "fastboot flash" command line matches this value. 1509 If not defined the default value "mbr" is used. 1510 1511- Journaling Flash filesystem support: 1512 CONFIG_JFFS2_NAND 1513 Define these for a default partition on a NAND device 1514 1515 CONFIG_SYS_JFFS2_FIRST_SECTOR, 1516 CONFIG_SYS_JFFS2_FIRST_BANK, CONFIG_SYS_JFFS2_NUM_BANKS 1517 Define these for a default partition on a NOR device 1518 1519- Keyboard Support: 1520 See Kconfig help for available keyboard drivers. 1521 1522 CONFIG_KEYBOARD 1523 1524 Define this to enable a custom keyboard support. 1525 This simply calls drv_keyboard_init() which must be 1526 defined in your board-specific files. This option is deprecated 1527 and is only used by novena. For new boards, use driver model 1528 instead. 1529 1530- Video support: 1531 CONFIG_FSL_DIU_FB 1532 Enable the Freescale DIU video driver. Reference boards for 1533 SOCs that have a DIU should define this macro to enable DIU 1534 support, and should also define these other macros: 1535 1536 CONFIG_SYS_DIU_ADDR 1537 CONFIG_VIDEO 1538 CONFIG_CFB_CONSOLE 1539 CONFIG_VIDEO_SW_CURSOR 1540 CONFIG_VGA_AS_SINGLE_DEVICE 1541 CONFIG_VIDEO_LOGO 1542 CONFIG_VIDEO_BMP_LOGO 1543 1544 The DIU driver will look for the 'video-mode' environment 1545 variable, and if defined, enable the DIU as a console during 1546 boot. See the documentation file doc/README.video for a 1547 description of this variable. 1548 1549- LCD Support: CONFIG_LCD 1550 1551 Define this to enable LCD support (for output to LCD 1552 display); also select one of the supported displays 1553 by defining one of these: 1554 1555 CONFIG_ATMEL_LCD: 1556 1557 HITACHI TX09D70VM1CCA, 3.5", 240x320. 1558 1559 CONFIG_NEC_NL6448AC33: 1560 1561 NEC NL6448AC33-18. Active, color, single scan. 1562 1563 CONFIG_NEC_NL6448BC20 1564 1565 NEC NL6448BC20-08. 6.5", 640x480. 1566 Active, color, single scan. 1567 1568 CONFIG_NEC_NL6448BC33_54 1569 1570 NEC NL6448BC33-54. 10.4", 640x480. 1571 Active, color, single scan. 1572 1573 CONFIG_SHARP_16x9 1574 1575 Sharp 320x240. Active, color, single scan. 1576 It isn't 16x9, and I am not sure what it is. 1577 1578 CONFIG_SHARP_LQ64D341 1579 1580 Sharp LQ64D341 display, 640x480. 1581 Active, color, single scan. 1582 1583 CONFIG_HLD1045 1584 1585 HLD1045 display, 640x480. 1586 Active, color, single scan. 1587 1588 CONFIG_OPTREX_BW 1589 1590 Optrex CBL50840-2 NF-FW 99 22 M5 1591 or 1592 Hitachi LMG6912RPFC-00T 1593 or 1594 Hitachi SP14Q002 1595 1596 320x240. Black & white. 1597 1598 CONFIG_LCD_ALIGNMENT 1599 1600 Normally the LCD is page-aligned (typically 4KB). If this is 1601 defined then the LCD will be aligned to this value instead. 1602 For ARM it is sometimes useful to use MMU_SECTION_SIZE 1603 here, since it is cheaper to change data cache settings on 1604 a per-section basis. 1605 1606 1607 CONFIG_LCD_ROTATION 1608 1609 Sometimes, for example if the display is mounted in portrait 1610 mode or even if it's mounted landscape but rotated by 180degree, 1611 we need to rotate our content of the display relative to the 1612 framebuffer, so that user can read the messages which are 1613 printed out. 1614 Once CONFIG_LCD_ROTATION is defined, the lcd_console will be 1615 initialized with a given rotation from "vl_rot" out of 1616 "vidinfo_t" which is provided by the board specific code. 1617 The value for vl_rot is coded as following (matching to 1618 fbcon=rotate:<n> linux-kernel commandline): 1619 0 = no rotation respectively 0 degree 1620 1 = 90 degree rotation 1621 2 = 180 degree rotation 1622 3 = 270 degree rotation 1623 1624 If CONFIG_LCD_ROTATION is not defined, the console will be 1625 initialized with 0degree rotation. 1626 1627 CONFIG_LCD_BMP_RLE8 1628 1629 Support drawing of RLE8-compressed bitmaps on the LCD. 1630 1631 CONFIG_I2C_EDID 1632 1633 Enables an 'i2c edid' command which can read EDID 1634 information over I2C from an attached LCD display. 1635 1636- Splash Screen Support: CONFIG_SPLASH_SCREEN 1637 1638 If this option is set, the environment is checked for 1639 a variable "splashimage". If found, the usual display 1640 of logo, copyright and system information on the LCD 1641 is suppressed and the BMP image at the address 1642 specified in "splashimage" is loaded instead. The 1643 console is redirected to the "nulldev", too. This 1644 allows for a "silent" boot where a splash screen is 1645 loaded very quickly after power-on. 1646 1647 CONFIG_SPLASHIMAGE_GUARD 1648 1649 If this option is set, then U-Boot will prevent the environment 1650 variable "splashimage" from being set to a problematic address 1651 (see doc/README.displaying-bmps). 1652 This option is useful for targets where, due to alignment 1653 restrictions, an improperly aligned BMP image will cause a data 1654 abort. If you think you will not have problems with unaligned 1655 accesses (for example because your toolchain prevents them) 1656 there is no need to set this option. 1657 1658 CONFIG_SPLASH_SCREEN_ALIGN 1659 1660 If this option is set the splash image can be freely positioned 1661 on the screen. Environment variable "splashpos" specifies the 1662 position as "x,y". If a positive number is given it is used as 1663 number of pixel from left/top. If a negative number is given it 1664 is used as number of pixel from right/bottom. You can also 1665 specify 'm' for centering the image. 1666 1667 Example: 1668 setenv splashpos m,m 1669 => image at center of screen 1670 1671 setenv splashpos 30,20 1672 => image at x = 30 and y = 20 1673 1674 setenv splashpos -10,m 1675 => vertically centered image 1676 at x = dspWidth - bmpWidth - 9 1677 1678- Gzip compressed BMP image support: CONFIG_VIDEO_BMP_GZIP 1679 1680 If this option is set, additionally to standard BMP 1681 images, gzipped BMP images can be displayed via the 1682 splashscreen support or the bmp command. 1683 1684- Run length encoded BMP image (RLE8) support: CONFIG_VIDEO_BMP_RLE8 1685 1686 If this option is set, 8-bit RLE compressed BMP images 1687 can be displayed via the splashscreen support or the 1688 bmp command. 1689 1690- Compression support: 1691 CONFIG_GZIP 1692 1693 Enabled by default to support gzip compressed images. 1694 1695 CONFIG_BZIP2 1696 1697 If this option is set, support for bzip2 compressed 1698 images is included. If not, only uncompressed and gzip 1699 compressed images are supported. 1700 1701 NOTE: the bzip2 algorithm requires a lot of RAM, so 1702 the malloc area (as defined by CONFIG_SYS_MALLOC_LEN) should 1703 be at least 4MB. 1704 1705 CONFIG_LZO 1706 1707 If this option is set, support for LZO compressed images 1708 is included. 1709 1710- MII/PHY support: 1711 CONFIG_PHY_ADDR 1712 1713 The address of PHY on MII bus. 1714 1715 CONFIG_PHY_CLOCK_FREQ (ppc4xx) 1716 1717 The clock frequency of the MII bus 1718 1719 CONFIG_PHY_GIGE 1720 1721 If this option is set, support for speed/duplex 1722 detection of gigabit PHY is included. 1723 1724 CONFIG_PHY_RESET_DELAY 1725 1726 Some PHY like Intel LXT971A need extra delay after 1727 reset before any MII register access is possible. 1728 For such PHY, set this option to the usec delay 1729 required. (minimum 300usec for LXT971A) 1730 1731 CONFIG_PHY_CMD_DELAY (ppc4xx) 1732 1733 Some PHY like Intel LXT971A need extra delay after 1734 command issued before MII status register can be read 1735 1736- IP address: 1737 CONFIG_IPADDR 1738 1739 Define a default value for the IP address to use for 1740 the default Ethernet interface, in case this is not 1741 determined through e.g. bootp. 1742 (Environment variable "ipaddr") 1743 1744- Server IP address: 1745 CONFIG_SERVERIP 1746 1747 Defines a default value for the IP address of a TFTP 1748 server to contact when using the "tftboot" command. 1749 (Environment variable "serverip") 1750 1751 CONFIG_KEEP_SERVERADDR 1752 1753 Keeps the server's MAC address, in the env 'serveraddr' 1754 for passing to bootargs (like Linux's netconsole option) 1755 1756- Gateway IP address: 1757 CONFIG_GATEWAYIP 1758 1759 Defines a default value for the IP address of the 1760 default router where packets to other networks are 1761 sent to. 1762 (Environment variable "gatewayip") 1763 1764- Subnet mask: 1765 CONFIG_NETMASK 1766 1767 Defines a default value for the subnet mask (or 1768 routing prefix) which is used to determine if an IP 1769 address belongs to the local subnet or needs to be 1770 forwarded through a router. 1771 (Environment variable "netmask") 1772 1773- Multicast TFTP Mode: 1774 CONFIG_MCAST_TFTP 1775 1776 Defines whether you want to support multicast TFTP as per 1777 rfc-2090; for example to work with atftp. Lets lots of targets 1778 tftp down the same boot image concurrently. Note: the Ethernet 1779 driver in use must provide a function: mcast() to join/leave a 1780 multicast group. 1781 1782- BOOTP Recovery Mode: 1783 CONFIG_BOOTP_RANDOM_DELAY 1784 1785 If you have many targets in a network that try to 1786 boot using BOOTP, you may want to avoid that all 1787 systems send out BOOTP requests at precisely the same 1788 moment (which would happen for instance at recovery 1789 from a power failure, when all systems will try to 1790 boot, thus flooding the BOOTP server. Defining 1791 CONFIG_BOOTP_RANDOM_DELAY causes a random delay to be 1792 inserted before sending out BOOTP requests. The 1793 following delays are inserted then: 1794 1795 1st BOOTP request: delay 0 ... 1 sec 1796 2nd BOOTP request: delay 0 ... 2 sec 1797 3rd BOOTP request: delay 0 ... 4 sec 1798 4th and following 1799 BOOTP requests: delay 0 ... 8 sec 1800 1801 CONFIG_BOOTP_ID_CACHE_SIZE 1802 1803 BOOTP packets are uniquely identified using a 32-bit ID. The 1804 server will copy the ID from client requests to responses and 1805 U-Boot will use this to determine if it is the destination of 1806 an incoming response. Some servers will check that addresses 1807 aren't in use before handing them out (usually using an ARP 1808 ping) and therefore take up to a few hundred milliseconds to 1809 respond. Network congestion may also influence the time it 1810 takes for a response to make it back to the client. If that 1811 time is too long, U-Boot will retransmit requests. In order 1812 to allow earlier responses to still be accepted after these 1813 retransmissions, U-Boot's BOOTP client keeps a small cache of 1814 IDs. The CONFIG_BOOTP_ID_CACHE_SIZE controls the size of this 1815 cache. The default is to keep IDs for up to four outstanding 1816 requests. Increasing this will allow U-Boot to accept offers 1817 from a BOOTP client in networks with unusually high latency. 1818 1819- DHCP Advanced Options: 1820 You can fine tune the DHCP functionality by defining 1821 CONFIG_BOOTP_* symbols: 1822 1823 CONFIG_BOOTP_SUBNETMASK 1824 CONFIG_BOOTP_GATEWAY 1825 CONFIG_BOOTP_HOSTNAME 1826 CONFIG_BOOTP_NISDOMAIN 1827 CONFIG_BOOTP_BOOTPATH 1828 CONFIG_BOOTP_BOOTFILESIZE 1829 CONFIG_BOOTP_DNS 1830 CONFIG_BOOTP_DNS2 1831 CONFIG_BOOTP_SEND_HOSTNAME 1832 CONFIG_BOOTP_NTPSERVER 1833 CONFIG_BOOTP_TIMEOFFSET 1834 CONFIG_BOOTP_VENDOREX 1835 CONFIG_BOOTP_MAY_FAIL 1836 1837 CONFIG_BOOTP_SERVERIP - TFTP server will be the serverip 1838 environment variable, not the BOOTP server. 1839 1840 CONFIG_BOOTP_MAY_FAIL - If the DHCP server is not found 1841 after the configured retry count, the call will fail 1842 instead of starting over. This can be used to fail over 1843 to Link-local IP address configuration if the DHCP server 1844 is not available. 1845 1846 CONFIG_BOOTP_DNS2 - If a DHCP client requests the DNS 1847 serverip from a DHCP server, it is possible that more 1848 than one DNS serverip is offered to the client. 1849 If CONFIG_BOOTP_DNS2 is enabled, the secondary DNS 1850 serverip will be stored in the additional environment 1851 variable "dnsip2". The first DNS serverip is always 1852 stored in the variable "dnsip", when CONFIG_BOOTP_DNS 1853 is defined. 1854 1855 CONFIG_BOOTP_SEND_HOSTNAME - Some DHCP servers are capable 1856 to do a dynamic update of a DNS server. To do this, they 1857 need the hostname of the DHCP requester. 1858 If CONFIG_BOOTP_SEND_HOSTNAME is defined, the content 1859 of the "hostname" environment variable is passed as 1860 option 12 to the DHCP server. 1861 1862 CONFIG_BOOTP_DHCP_REQUEST_DELAY 1863 1864 A 32bit value in microseconds for a delay between 1865 receiving a "DHCP Offer" and sending the "DHCP Request". 1866 This fixes a problem with certain DHCP servers that don't 1867 respond 100% of the time to a "DHCP request". E.g. On an 1868 AT91RM9200 processor running at 180MHz, this delay needed 1869 to be *at least* 15,000 usec before a Windows Server 2003 1870 DHCP server would reply 100% of the time. I recommend at 1871 least 50,000 usec to be safe. The alternative is to hope 1872 that one of the retries will be successful but note that 1873 the DHCP timeout and retry process takes a longer than 1874 this delay. 1875 1876 - Link-local IP address negotiation: 1877 Negotiate with other link-local clients on the local network 1878 for an address that doesn't require explicit configuration. 1879 This is especially useful if a DHCP server cannot be guaranteed 1880 to exist in all environments that the device must operate. 1881 1882 See doc/README.link-local for more information. 1883 1884 - CDP Options: 1885 CONFIG_CDP_DEVICE_ID 1886 1887 The device id used in CDP trigger frames. 1888 1889 CONFIG_CDP_DEVICE_ID_PREFIX 1890 1891 A two character string which is prefixed to the MAC address 1892 of the device. 1893 1894 CONFIG_CDP_PORT_ID 1895 1896 A printf format string which contains the ascii name of 1897 the port. Normally is set to "eth%d" which sets 1898 eth0 for the first Ethernet, eth1 for the second etc. 1899 1900 CONFIG_CDP_CAPABILITIES 1901 1902 A 32bit integer which indicates the device capabilities; 1903 0x00000010 for a normal host which does not forwards. 1904 1905 CONFIG_CDP_VERSION 1906 1907 An ascii string containing the version of the software. 1908 1909 CONFIG_CDP_PLATFORM 1910 1911 An ascii string containing the name of the platform. 1912 1913 CONFIG_CDP_TRIGGER 1914 1915 A 32bit integer sent on the trigger. 1916 1917 CONFIG_CDP_POWER_CONSUMPTION 1918 1919 A 16bit integer containing the power consumption of the 1920 device in .1 of milliwatts. 1921 1922 CONFIG_CDP_APPLIANCE_VLAN_TYPE 1923 1924 A byte containing the id of the VLAN. 1925 1926- Status LED: CONFIG_LED_STATUS 1927 1928 Several configurations allow to display the current 1929 status using a LED. For instance, the LED will blink 1930 fast while running U-Boot code, stop blinking as 1931 soon as a reply to a BOOTP request was received, and 1932 start blinking slow once the Linux kernel is running 1933 (supported by a status LED driver in the Linux 1934 kernel). Defining CONFIG_LED_STATUS enables this 1935 feature in U-Boot. 1936 1937 Additional options: 1938 1939 CONFIG_LED_STATUS_GPIO 1940 The status LED can be connected to a GPIO pin. 1941 In such cases, the gpio_led driver can be used as a 1942 status LED backend implementation. Define CONFIG_LED_STATUS_GPIO 1943 to include the gpio_led driver in the U-Boot binary. 1944 1945 CONFIG_GPIO_LED_INVERTED_TABLE 1946 Some GPIO connected LEDs may have inverted polarity in which 1947 case the GPIO high value corresponds to LED off state and 1948 GPIO low value corresponds to LED on state. 1949 In such cases CONFIG_GPIO_LED_INVERTED_TABLE may be defined 1950 with a list of GPIO LEDs that have inverted polarity. 1951 1952- CAN Support: CONFIG_CAN_DRIVER 1953 1954 Defining CONFIG_CAN_DRIVER enables CAN driver support 1955 on those systems that support this (optional) 1956 feature, like the TQM8xxL modules. 1957 1958- I2C Support: CONFIG_SYS_I2C 1959 1960 This enable the NEW i2c subsystem, and will allow you to use 1961 i2c commands at the u-boot command line (as long as you set 1962 CONFIG_CMD_I2C in CONFIG_COMMANDS) and communicate with i2c 1963 based realtime clock chips or other i2c devices. See 1964 common/cmd_i2c.c for a description of the command line 1965 interface. 1966 1967 ported i2c driver to the new framework: 1968 - drivers/i2c/soft_i2c.c: 1969 - activate first bus with CONFIG_SYS_I2C_SOFT define 1970 CONFIG_SYS_I2C_SOFT_SPEED and CONFIG_SYS_I2C_SOFT_SLAVE 1971 for defining speed and slave address 1972 - activate second bus with I2C_SOFT_DECLARATIONS2 define 1973 CONFIG_SYS_I2C_SOFT_SPEED_2 and CONFIG_SYS_I2C_SOFT_SLAVE_2 1974 for defining speed and slave address 1975 - activate third bus with I2C_SOFT_DECLARATIONS3 define 1976 CONFIG_SYS_I2C_SOFT_SPEED_3 and CONFIG_SYS_I2C_SOFT_SLAVE_3 1977 for defining speed and slave address 1978 - activate fourth bus with I2C_SOFT_DECLARATIONS4 define 1979 CONFIG_SYS_I2C_SOFT_SPEED_4 and CONFIG_SYS_I2C_SOFT_SLAVE_4 1980 for defining speed and slave address 1981 1982 - drivers/i2c/fsl_i2c.c: 1983 - activate i2c driver with CONFIG_SYS_I2C_FSL 1984 define CONFIG_SYS_FSL_I2C_OFFSET for setting the register 1985 offset CONFIG_SYS_FSL_I2C_SPEED for the i2c speed and 1986 CONFIG_SYS_FSL_I2C_SLAVE for the slave addr of the first 1987 bus. 1988 - If your board supports a second fsl i2c bus, define 1989 CONFIG_SYS_FSL_I2C2_OFFSET for the register offset 1990 CONFIG_SYS_FSL_I2C2_SPEED for the speed and 1991 CONFIG_SYS_FSL_I2C2_SLAVE for the slave address of the 1992 second bus. 1993 1994 - drivers/i2c/tegra_i2c.c: 1995 - activate this driver with CONFIG_SYS_I2C_TEGRA 1996 - This driver adds 4 i2c buses with a fix speed from 1997 100000 and the slave addr 0! 1998 1999 - drivers/i2c/ppc4xx_i2c.c 2000 - activate this driver with CONFIG_SYS_I2C_PPC4XX 2001 - CONFIG_SYS_I2C_PPC4XX_CH0 activate hardware channel 0 2002 - CONFIG_SYS_I2C_PPC4XX_CH1 activate hardware channel 1 2003 2004 - drivers/i2c/i2c_mxc.c 2005 - activate this driver with CONFIG_SYS_I2C_MXC 2006 - enable bus 1 with CONFIG_SYS_I2C_MXC_I2C1 2007 - enable bus 2 with CONFIG_SYS_I2C_MXC_I2C2 2008 - enable bus 3 with CONFIG_SYS_I2C_MXC_I2C3 2009 - enable bus 4 with CONFIG_SYS_I2C_MXC_I2C4 2010 - define speed for bus 1 with CONFIG_SYS_MXC_I2C1_SPEED 2011 - define slave for bus 1 with CONFIG_SYS_MXC_I2C1_SLAVE 2012 - define speed for bus 2 with CONFIG_SYS_MXC_I2C2_SPEED 2013 - define slave for bus 2 with CONFIG_SYS_MXC_I2C2_SLAVE 2014 - define speed for bus 3 with CONFIG_SYS_MXC_I2C3_SPEED 2015 - define slave for bus 3 with CONFIG_SYS_MXC_I2C3_SLAVE 2016 - define speed for bus 4 with CONFIG_SYS_MXC_I2C4_SPEED 2017 - define slave for bus 4 with CONFIG_SYS_MXC_I2C4_SLAVE 2018 If those defines are not set, default value is 100000 2019 for speed, and 0 for slave. 2020 2021 - drivers/i2c/rcar_i2c.c: 2022 - activate this driver with CONFIG_SYS_I2C_RCAR 2023 - This driver adds 4 i2c buses 2024 2025 - CONFIG_SYS_RCAR_I2C0_BASE for setting the register channel 0 2026 - CONFIG_SYS_RCAR_I2C0_SPEED for for the speed channel 0 2027 - CONFIG_SYS_RCAR_I2C1_BASE for setting the register channel 1 2028 - CONFIG_SYS_RCAR_I2C1_SPEED for for the speed channel 1 2029 - CONFIG_SYS_RCAR_I2C2_BASE for setting the register channel 2 2030 - CONFIG_SYS_RCAR_I2C2_SPEED for for the speed channel 2 2031 - CONFIG_SYS_RCAR_I2C3_BASE for setting the register channel 3 2032 - CONFIG_SYS_RCAR_I2C3_SPEED for for the speed channel 3 2033 - CONFIF_SYS_RCAR_I2C_NUM_CONTROLLERS for number of i2c buses 2034 2035 - drivers/i2c/sh_i2c.c: 2036 - activate this driver with CONFIG_SYS_I2C_SH 2037 - This driver adds from 2 to 5 i2c buses 2038 2039 - CONFIG_SYS_I2C_SH_BASE0 for setting the register channel 0 2040 - CONFIG_SYS_I2C_SH_SPEED0 for for the speed channel 0 2041 - CONFIG_SYS_I2C_SH_BASE1 for setting the register channel 1 2042 - CONFIG_SYS_I2C_SH_SPEED1 for for the speed channel 1 2043 - CONFIG_SYS_I2C_SH_BASE2 for setting the register channel 2 2044 - CONFIG_SYS_I2C_SH_SPEED2 for for the speed channel 2 2045 - CONFIG_SYS_I2C_SH_BASE3 for setting the register channel 3 2046 - CONFIG_SYS_I2C_SH_SPEED3 for for the speed channel 3 2047 - CONFIG_SYS_I2C_SH_BASE4 for setting the register channel 4 2048 - CONFIG_SYS_I2C_SH_SPEED4 for for the speed channel 4 2049 - CONFIG_SYS_I2C_SH_NUM_CONTROLLERS for number of i2c buses 2050 2051 - drivers/i2c/omap24xx_i2c.c 2052 - activate this driver with CONFIG_SYS_I2C_OMAP24XX 2053 - CONFIG_SYS_OMAP24_I2C_SPEED speed channel 0 2054 - CONFIG_SYS_OMAP24_I2C_SLAVE slave addr channel 0 2055 - CONFIG_SYS_OMAP24_I2C_SPEED1 speed channel 1 2056 - CONFIG_SYS_OMAP24_I2C_SLAVE1 slave addr channel 1 2057 - CONFIG_SYS_OMAP24_I2C_SPEED2 speed channel 2 2058 - CONFIG_SYS_OMAP24_I2C_SLAVE2 slave addr channel 2 2059 - CONFIG_SYS_OMAP24_I2C_SPEED3 speed channel 3 2060 - CONFIG_SYS_OMAP24_I2C_SLAVE3 slave addr channel 3 2061 - CONFIG_SYS_OMAP24_I2C_SPEED4 speed channel 4 2062 - CONFIG_SYS_OMAP24_I2C_SLAVE4 slave addr channel 4 2063 2064 - drivers/i2c/zynq_i2c.c 2065 - activate this driver with CONFIG_SYS_I2C_ZYNQ 2066 - set CONFIG_SYS_I2C_ZYNQ_SPEED for speed setting 2067 - set CONFIG_SYS_I2C_ZYNQ_SLAVE for slave addr 2068 2069 - drivers/i2c/s3c24x0_i2c.c: 2070 - activate this driver with CONFIG_SYS_I2C_S3C24X0 2071 - This driver adds i2c buses (11 for Exynos5250, Exynos5420 2072 9 i2c buses for Exynos4 and 1 for S3C24X0 SoCs from Samsung) 2073 with a fix speed from 100000 and the slave addr 0! 2074 2075 - drivers/i2c/ihs_i2c.c 2076 - activate this driver with CONFIG_SYS_I2C_IHS 2077 - CONFIG_SYS_I2C_IHS_CH0 activate hardware channel 0 2078 - CONFIG_SYS_I2C_IHS_SPEED_0 speed channel 0 2079 - CONFIG_SYS_I2C_IHS_SLAVE_0 slave addr channel 0 2080 - CONFIG_SYS_I2C_IHS_CH1 activate hardware channel 1 2081 - CONFIG_SYS_I2C_IHS_SPEED_1 speed channel 1 2082 - CONFIG_SYS_I2C_IHS_SLAVE_1 slave addr channel 1 2083 - CONFIG_SYS_I2C_IHS_CH2 activate hardware channel 2 2084 - CONFIG_SYS_I2C_IHS_SPEED_2 speed channel 2 2085 - CONFIG_SYS_I2C_IHS_SLAVE_2 slave addr channel 2 2086 - CONFIG_SYS_I2C_IHS_CH3 activate hardware channel 3 2087 - CONFIG_SYS_I2C_IHS_SPEED_3 speed channel 3 2088 - CONFIG_SYS_I2C_IHS_SLAVE_3 slave addr channel 3 2089 - activate dual channel with CONFIG_SYS_I2C_IHS_DUAL 2090 - CONFIG_SYS_I2C_IHS_SPEED_0_1 speed channel 0_1 2091 - CONFIG_SYS_I2C_IHS_SLAVE_0_1 slave addr channel 0_1 2092 - CONFIG_SYS_I2C_IHS_SPEED_1_1 speed channel 1_1 2093 - CONFIG_SYS_I2C_IHS_SLAVE_1_1 slave addr channel 1_1 2094 - CONFIG_SYS_I2C_IHS_SPEED_2_1 speed channel 2_1 2095 - CONFIG_SYS_I2C_IHS_SLAVE_2_1 slave addr channel 2_1 2096 - CONFIG_SYS_I2C_IHS_SPEED_3_1 speed channel 3_1 2097 - CONFIG_SYS_I2C_IHS_SLAVE_3_1 slave addr channel 3_1 2098 2099 additional defines: 2100 2101 CONFIG_SYS_NUM_I2C_BUSES 2102 Hold the number of i2c buses you want to use. 2103 2104 CONFIG_SYS_I2C_DIRECT_BUS 2105 define this, if you don't use i2c muxes on your hardware. 2106 if CONFIG_SYS_I2C_MAX_HOPS is not defined or == 0 you can 2107 omit this define. 2108 2109 CONFIG_SYS_I2C_MAX_HOPS 2110 define how many muxes are maximal consecutively connected 2111 on one i2c bus. If you not use i2c muxes, omit this 2112 define. 2113 2114 CONFIG_SYS_I2C_BUSES 2115 hold a list of buses you want to use, only used if 2116 CONFIG_SYS_I2C_DIRECT_BUS is not defined, for example 2117 a board with CONFIG_SYS_I2C_MAX_HOPS = 1 and 2118 CONFIG_SYS_NUM_I2C_BUSES = 9: 2119 2120 CONFIG_SYS_I2C_BUSES {{0, {I2C_NULL_HOP}}, \ 2121 {0, {{I2C_MUX_PCA9547, 0x70, 1}}}, \ 2122 {0, {{I2C_MUX_PCA9547, 0x70, 2}}}, \ 2123 {0, {{I2C_MUX_PCA9547, 0x70, 3}}}, \ 2124 {0, {{I2C_MUX_PCA9547, 0x70, 4}}}, \ 2125 {0, {{I2C_MUX_PCA9547, 0x70, 5}}}, \ 2126 {1, {I2C_NULL_HOP}}, \ 2127 {1, {{I2C_MUX_PCA9544, 0x72, 1}}}, \ 2128 {1, {{I2C_MUX_PCA9544, 0x72, 2}}}, \ 2129 } 2130 2131 which defines 2132 bus 0 on adapter 0 without a mux 2133 bus 1 on adapter 0 with a PCA9547 on address 0x70 port 1 2134 bus 2 on adapter 0 with a PCA9547 on address 0x70 port 2 2135 bus 3 on adapter 0 with a PCA9547 on address 0x70 port 3 2136 bus 4 on adapter 0 with a PCA9547 on address 0x70 port 4 2137 bus 5 on adapter 0 with a PCA9547 on address 0x70 port 5 2138 bus 6 on adapter 1 without a mux 2139 bus 7 on adapter 1 with a PCA9544 on address 0x72 port 1 2140 bus 8 on adapter 1 with a PCA9544 on address 0x72 port 2 2141 2142 If you do not have i2c muxes on your board, omit this define. 2143 2144- Legacy I2C Support: 2145 If you use the software i2c interface (CONFIG_SYS_I2C_SOFT) 2146 then the following macros need to be defined (examples are 2147 from include/configs/lwmon.h): 2148 2149 I2C_INIT 2150 2151 (Optional). Any commands necessary to enable the I2C 2152 controller or configure ports. 2153 2154 eg: #define I2C_INIT (immr->im_cpm.cp_pbdir |= PB_SCL) 2155 2156 I2C_PORT 2157 2158 (Only for MPC8260 CPU). The I/O port to use (the code 2159 assumes both bits are on the same port). Valid values 2160 are 0..3 for ports A..D. 2161 2162 I2C_ACTIVE 2163 2164 The code necessary to make the I2C data line active 2165 (driven). If the data line is open collector, this 2166 define can be null. 2167 2168 eg: #define I2C_ACTIVE (immr->im_cpm.cp_pbdir |= PB_SDA) 2169 2170 I2C_TRISTATE 2171 2172 The code necessary to make the I2C data line tri-stated 2173 (inactive). If the data line is open collector, this 2174 define can be null. 2175 2176 eg: #define I2C_TRISTATE (immr->im_cpm.cp_pbdir &= ~PB_SDA) 2177 2178 I2C_READ 2179 2180 Code that returns true if the I2C data line is high, 2181 false if it is low. 2182 2183 eg: #define I2C_READ ((immr->im_cpm.cp_pbdat & PB_SDA) != 0) 2184 2185 I2C_SDA(bit) 2186 2187 If <bit> is true, sets the I2C data line high. If it 2188 is false, it clears it (low). 2189 2190 eg: #define I2C_SDA(bit) \ 2191 if(bit) immr->im_cpm.cp_pbdat |= PB_SDA; \ 2192 else immr->im_cpm.cp_pbdat &= ~PB_SDA 2193 2194 I2C_SCL(bit) 2195 2196 If <bit> is true, sets the I2C clock line high. If it 2197 is false, it clears it (low). 2198 2199 eg: #define I2C_SCL(bit) \ 2200 if(bit) immr->im_cpm.cp_pbdat |= PB_SCL; \ 2201 else immr->im_cpm.cp_pbdat &= ~PB_SCL 2202 2203 I2C_DELAY 2204 2205 This delay is invoked four times per clock cycle so this 2206 controls the rate of data transfer. The data rate thus 2207 is 1 / (I2C_DELAY * 4). Often defined to be something 2208 like: 2209 2210 #define I2C_DELAY udelay(2) 2211 2212 CONFIG_SOFT_I2C_GPIO_SCL / CONFIG_SOFT_I2C_GPIO_SDA 2213 2214 If your arch supports the generic GPIO framework (asm/gpio.h), 2215 then you may alternatively define the two GPIOs that are to be 2216 used as SCL / SDA. Any of the previous I2C_xxx macros will 2217 have GPIO-based defaults assigned to them as appropriate. 2218 2219 You should define these to the GPIO value as given directly to 2220 the generic GPIO functions. 2221 2222 CONFIG_SYS_I2C_INIT_BOARD 2223 2224 When a board is reset during an i2c bus transfer 2225 chips might think that the current transfer is still 2226 in progress. On some boards it is possible to access 2227 the i2c SCLK line directly, either by using the 2228 processor pin as a GPIO or by having a second pin 2229 connected to the bus. If this option is defined a 2230 custom i2c_init_board() routine in boards/xxx/board.c 2231 is run early in the boot sequence. 2232 2233 CONFIG_I2C_MULTI_BUS 2234 2235 This option allows the use of multiple I2C buses, each of which 2236 must have a controller. At any point in time, only one bus is 2237 active. To switch to a different bus, use the 'i2c dev' command. 2238 Note that bus numbering is zero-based. 2239 2240 CONFIG_SYS_I2C_NOPROBES 2241 2242 This option specifies a list of I2C devices that will be skipped 2243 when the 'i2c probe' command is issued. If CONFIG_I2C_MULTI_BUS 2244 is set, specify a list of bus-device pairs. Otherwise, specify 2245 a 1D array of device addresses 2246 2247 e.g. 2248 #undef CONFIG_I2C_MULTI_BUS 2249 #define CONFIG_SYS_I2C_NOPROBES {0x50,0x68} 2250 2251 will skip addresses 0x50 and 0x68 on a board with one I2C bus 2252 2253 #define CONFIG_I2C_MULTI_BUS 2254 #define CONFIG_SYS_I2C_NOPROBES {{0,0x50},{0,0x68},{1,0x54}} 2255 2256 will skip addresses 0x50 and 0x68 on bus 0 and address 0x54 on bus 1 2257 2258 CONFIG_SYS_SPD_BUS_NUM 2259 2260 If defined, then this indicates the I2C bus number for DDR SPD. 2261 If not defined, then U-Boot assumes that SPD is on I2C bus 0. 2262 2263 CONFIG_SYS_RTC_BUS_NUM 2264 2265 If defined, then this indicates the I2C bus number for the RTC. 2266 If not defined, then U-Boot assumes that RTC is on I2C bus 0. 2267 2268 CONFIG_SOFT_I2C_READ_REPEATED_START 2269 2270 defining this will force the i2c_read() function in 2271 the soft_i2c driver to perform an I2C repeated start 2272 between writing the address pointer and reading the 2273 data. If this define is omitted the default behaviour 2274 of doing a stop-start sequence will be used. Most I2C 2275 devices can use either method, but some require one or 2276 the other. 2277 2278- SPI Support: CONFIG_SPI 2279 2280 Enables SPI driver (so far only tested with 2281 SPI EEPROM, also an instance works with Crystal A/D and 2282 D/As on the SACSng board) 2283 2284 CONFIG_SH_SPI 2285 2286 Enables the driver for SPI controller on SuperH. Currently 2287 only SH7757 is supported. 2288 2289 CONFIG_SOFT_SPI 2290 2291 Enables a software (bit-bang) SPI driver rather than 2292 using hardware support. This is a general purpose 2293 driver that only requires three general I/O port pins 2294 (two outputs, one input) to function. If this is 2295 defined, the board configuration must define several 2296 SPI configuration items (port pins to use, etc). For 2297 an example, see include/configs/sacsng.h. 2298 2299 CONFIG_HARD_SPI 2300 2301 Enables a hardware SPI driver for general-purpose reads 2302 and writes. As with CONFIG_SOFT_SPI, the board configuration 2303 must define a list of chip-select function pointers. 2304 Currently supported on some MPC8xxx processors. For an 2305 example, see include/configs/mpc8349emds.h. 2306 2307 CONFIG_MXC_SPI 2308 2309 Enables the driver for the SPI controllers on i.MX and MXC 2310 SoCs. Currently i.MX31/35/51 are supported. 2311 2312 CONFIG_SYS_SPI_MXC_WAIT 2313 Timeout for waiting until spi transfer completed. 2314 default: (CONFIG_SYS_HZ/100) /* 10 ms */ 2315 2316- FPGA Support: CONFIG_FPGA 2317 2318 Enables FPGA subsystem. 2319 2320 CONFIG_FPGA_<vendor> 2321 2322 Enables support for specific chip vendors. 2323 (ALTERA, XILINX) 2324 2325 CONFIG_FPGA_<family> 2326 2327 Enables support for FPGA family. 2328 (SPARTAN2, SPARTAN3, VIRTEX2, CYCLONE2, ACEX1K, ACEX) 2329 2330 CONFIG_FPGA_COUNT 2331 2332 Specify the number of FPGA devices to support. 2333 2334 CONFIG_SYS_FPGA_PROG_FEEDBACK 2335 2336 Enable printing of hash marks during FPGA configuration. 2337 2338 CONFIG_SYS_FPGA_CHECK_BUSY 2339 2340 Enable checks on FPGA configuration interface busy 2341 status by the configuration function. This option 2342 will require a board or device specific function to 2343 be written. 2344 2345 CONFIG_FPGA_DELAY 2346 2347 If defined, a function that provides delays in the FPGA 2348 configuration driver. 2349 2350 CONFIG_SYS_FPGA_CHECK_CTRLC 2351 Allow Control-C to interrupt FPGA configuration 2352 2353 CONFIG_SYS_FPGA_CHECK_ERROR 2354 2355 Check for configuration errors during FPGA bitfile 2356 loading. For example, abort during Virtex II 2357 configuration if the INIT_B line goes low (which 2358 indicated a CRC error). 2359 2360 CONFIG_SYS_FPGA_WAIT_INIT 2361 2362 Maximum time to wait for the INIT_B line to de-assert 2363 after PROB_B has been de-asserted during a Virtex II 2364 FPGA configuration sequence. The default time is 500 2365 ms. 2366 2367 CONFIG_SYS_FPGA_WAIT_BUSY 2368 2369 Maximum time to wait for BUSY to de-assert during 2370 Virtex II FPGA configuration. The default is 5 ms. 2371 2372 CONFIG_SYS_FPGA_WAIT_CONFIG 2373 2374 Time to wait after FPGA configuration. The default is 2375 200 ms. 2376 2377- Configuration Management: 2378 CONFIG_BUILD_TARGET 2379 2380 Some SoCs need special image types (e.g. U-Boot binary 2381 with a special header) as build targets. By defining 2382 CONFIG_BUILD_TARGET in the SoC / board header, this 2383 special image will be automatically built upon calling 2384 make / buildman. 2385 2386 CONFIG_IDENT_STRING 2387 2388 If defined, this string will be added to the U-Boot 2389 version information (U_BOOT_VERSION) 2390 2391- Vendor Parameter Protection: 2392 2393 U-Boot considers the values of the environment 2394 variables "serial#" (Board Serial Number) and 2395 "ethaddr" (Ethernet Address) to be parameters that 2396 are set once by the board vendor / manufacturer, and 2397 protects these variables from casual modification by 2398 the user. Once set, these variables are read-only, 2399 and write or delete attempts are rejected. You can 2400 change this behaviour: 2401 2402 If CONFIG_ENV_OVERWRITE is #defined in your config 2403 file, the write protection for vendor parameters is 2404 completely disabled. Anybody can change or delete 2405 these parameters. 2406 2407 Alternatively, if you define _both_ an ethaddr in the 2408 default env _and_ CONFIG_OVERWRITE_ETHADDR_ONCE, a default 2409 Ethernet address is installed in the environment, 2410 which can be changed exactly ONCE by the user. [The 2411 serial# is unaffected by this, i. e. it remains 2412 read-only.] 2413 2414 The same can be accomplished in a more flexible way 2415 for any variable by configuring the type of access 2416 to allow for those variables in the ".flags" variable 2417 or define CONFIG_ENV_FLAGS_LIST_STATIC. 2418 2419- Protected RAM: 2420 CONFIG_PRAM 2421 2422 Define this variable to enable the reservation of 2423 "protected RAM", i. e. RAM which is not overwritten 2424 by U-Boot. Define CONFIG_PRAM to hold the number of 2425 kB you want to reserve for pRAM. You can overwrite 2426 this default value by defining an environment 2427 variable "pram" to the number of kB you want to 2428 reserve. Note that the board info structure will 2429 still show the full amount of RAM. If pRAM is 2430 reserved, a new environment variable "mem" will 2431 automatically be defined to hold the amount of 2432 remaining RAM in a form that can be passed as boot 2433 argument to Linux, for instance like that: 2434 2435 setenv bootargs ... mem=\${mem} 2436 saveenv 2437 2438 This way you can tell Linux not to use this memory, 2439 either, which results in a memory region that will 2440 not be affected by reboots. 2441 2442 *WARNING* If your board configuration uses automatic 2443 detection of the RAM size, you must make sure that 2444 this memory test is non-destructive. So far, the 2445 following board configurations are known to be 2446 "pRAM-clean": 2447 2448 IVMS8, IVML24, SPD8xx, TQM8xxL, 2449 HERMES, IP860, RPXlite, LWMON, 2450 FLAGADM, TQM8260 2451 2452- Access to physical memory region (> 4GB) 2453 Some basic support is provided for operations on memory not 2454 normally accessible to U-Boot - e.g. some architectures 2455 support access to more than 4GB of memory on 32-bit 2456 machines using physical address extension or similar. 2457 Define CONFIG_PHYSMEM to access this basic support, which 2458 currently only supports clearing the memory. 2459 2460- Error Recovery: 2461 CONFIG_PANIC_HANG 2462 2463 Define this variable to stop the system in case of a 2464 fatal error, so that you have to reset it manually. 2465 This is probably NOT a good idea for an embedded 2466 system where you want the system to reboot 2467 automatically as fast as possible, but it may be 2468 useful during development since you can try to debug 2469 the conditions that lead to the situation. 2470 2471 CONFIG_NET_RETRY_COUNT 2472 2473 This variable defines the number of retries for 2474 network operations like ARP, RARP, TFTP, or BOOTP 2475 before giving up the operation. If not defined, a 2476 default value of 5 is used. 2477 2478 CONFIG_ARP_TIMEOUT 2479 2480 Timeout waiting for an ARP reply in milliseconds. 2481 2482 CONFIG_NFS_TIMEOUT 2483 2484 Timeout in milliseconds used in NFS protocol. 2485 If you encounter "ERROR: Cannot umount" in nfs command, 2486 try longer timeout such as 2487 #define CONFIG_NFS_TIMEOUT 10000UL 2488 2489- Command Interpreter: 2490 CONFIG_AUTO_COMPLETE 2491 2492 Enable auto completion of commands using TAB. 2493 2494 CONFIG_SYS_PROMPT_HUSH_PS2 2495 2496 This defines the secondary prompt string, which is 2497 printed when the command interpreter needs more input 2498 to complete a command. Usually "> ". 2499 2500 Note: 2501 2502 In the current implementation, the local variables 2503 space and global environment variables space are 2504 separated. Local variables are those you define by 2505 simply typing `name=value'. To access a local 2506 variable later on, you have write `$name' or 2507 `${name}'; to execute the contents of a variable 2508 directly type `$name' at the command prompt. 2509 2510 Global environment variables are those you use 2511 setenv/printenv to work with. To run a command stored 2512 in such a variable, you need to use the run command, 2513 and you must not use the '$' sign to access them. 2514 2515 To store commands and special characters in a 2516 variable, please use double quotation marks 2517 surrounding the whole text of the variable, instead 2518 of the backslashes before semicolons and special 2519 symbols. 2520 2521- Command Line Editing and History: 2522 CONFIG_CMDLINE_EDITING 2523 2524 Enable editing and History functions for interactive 2525 command line input operations 2526 2527- Command Line PS1/PS2 support: 2528 CONFIG_CMDLINE_PS_SUPPORT 2529 2530 Enable support for changing the command prompt string 2531 at run-time. Only static string is supported so far. 2532 The string is obtained from environment variables PS1 2533 and PS2. 2534 2535- Default Environment: 2536 CONFIG_EXTRA_ENV_SETTINGS 2537 2538 Define this to contain any number of null terminated 2539 strings (variable = value pairs) that will be part of 2540 the default environment compiled into the boot image. 2541 2542 For example, place something like this in your 2543 board's config file: 2544 2545 #define CONFIG_EXTRA_ENV_SETTINGS \ 2546 "myvar1=value1\0" \ 2547 "myvar2=value2\0" 2548 2549 Warning: This method is based on knowledge about the 2550 internal format how the environment is stored by the 2551 U-Boot code. This is NOT an official, exported 2552 interface! Although it is unlikely that this format 2553 will change soon, there is no guarantee either. 2554 You better know what you are doing here. 2555 2556 Note: overly (ab)use of the default environment is 2557 discouraged. Make sure to check other ways to preset 2558 the environment like the "source" command or the 2559 boot command first. 2560 2561 CONFIG_ENV_VARS_UBOOT_CONFIG 2562 2563 Define this in order to add variables describing the 2564 U-Boot build configuration to the default environment. 2565 These will be named arch, cpu, board, vendor, and soc. 2566 2567 Enabling this option will cause the following to be defined: 2568 2569 - CONFIG_SYS_ARCH 2570 - CONFIG_SYS_CPU 2571 - CONFIG_SYS_BOARD 2572 - CONFIG_SYS_VENDOR 2573 - CONFIG_SYS_SOC 2574 2575 CONFIG_ENV_VARS_UBOOT_RUNTIME_CONFIG 2576 2577 Define this in order to add variables describing certain 2578 run-time determined information about the hardware to the 2579 environment. These will be named board_name, board_rev. 2580 2581 CONFIG_DELAY_ENVIRONMENT 2582 2583 Normally the environment is loaded when the board is 2584 initialised so that it is available to U-Boot. This inhibits 2585 that so that the environment is not available until 2586 explicitly loaded later by U-Boot code. With CONFIG_OF_CONTROL 2587 this is instead controlled by the value of 2588 /config/load-environment. 2589 2590- DataFlash Support: 2591 CONFIG_HAS_DATAFLASH 2592 2593 Defining this option enables DataFlash features and 2594 allows to read/write in Dataflash via the standard 2595 commands cp, md... 2596 2597- Serial Flash support 2598 CONFIG_CMD_SF 2599 2600 Defining this option enables SPI flash commands 2601 'sf probe/read/write/erase/update'. 2602 2603 Usage requires an initial 'probe' to define the serial 2604 flash parameters, followed by read/write/erase/update 2605 commands. 2606 2607 The following defaults may be provided by the platform 2608 to handle the common case when only a single serial 2609 flash is present on the system. 2610 2611 CONFIG_SF_DEFAULT_BUS Bus identifier 2612 CONFIG_SF_DEFAULT_CS Chip-select 2613 CONFIG_SF_DEFAULT_MODE (see include/spi.h) 2614 CONFIG_SF_DEFAULT_SPEED in Hz 2615 2616 CONFIG_CMD_SF_TEST 2617 2618 Define this option to include a destructive SPI flash 2619 test ('sf test'). 2620 2621 CONFIG_SF_DUAL_FLASH Dual flash memories 2622 2623 Define this option to use dual flash support where two flash 2624 memories can be connected with a given cs line. 2625 Currently Xilinx Zynq qspi supports these type of connections. 2626 2627- SystemACE Support: 2628 CONFIG_SYSTEMACE 2629 2630 Adding this option adds support for Xilinx SystemACE 2631 chips attached via some sort of local bus. The address 2632 of the chip must also be defined in the 2633 CONFIG_SYS_SYSTEMACE_BASE macro. For example: 2634 2635 #define CONFIG_SYSTEMACE 2636 #define CONFIG_SYS_SYSTEMACE_BASE 0xf0000000 2637 2638 When SystemACE support is added, the "ace" device type 2639 becomes available to the fat commands, i.e. fatls. 2640 2641- TFTP Fixed UDP Port: 2642 CONFIG_TFTP_PORT 2643 2644 If this is defined, the environment variable tftpsrcp 2645 is used to supply the TFTP UDP source port value. 2646 If tftpsrcp isn't defined, the normal pseudo-random port 2647 number generator is used. 2648 2649 Also, the environment variable tftpdstp is used to supply 2650 the TFTP UDP destination port value. If tftpdstp isn't 2651 defined, the normal port 69 is used. 2652 2653 The purpose for tftpsrcp is to allow a TFTP server to 2654 blindly start the TFTP transfer using the pre-configured 2655 target IP address and UDP port. This has the effect of 2656 "punching through" the (Windows XP) firewall, allowing 2657 the remainder of the TFTP transfer to proceed normally. 2658 A better solution is to properly configure the firewall, 2659 but sometimes that is not allowed. 2660 2661- bootcount support: 2662 CONFIG_BOOTCOUNT_LIMIT 2663 2664 This enables the bootcounter support, see: 2665 http://www.denx.de/wiki/DULG/UBootBootCountLimit 2666 2667 CONFIG_AT91SAM9XE 2668 enable special bootcounter support on at91sam9xe based boards. 2669 CONFIG_SOC_DA8XX 2670 enable special bootcounter support on da850 based boards. 2671 CONFIG_BOOTCOUNT_RAM 2672 enable support for the bootcounter in RAM 2673 CONFIG_BOOTCOUNT_I2C 2674 enable support for the bootcounter on an i2c (like RTC) device. 2675 CONFIG_SYS_I2C_RTC_ADDR = i2c chip address 2676 CONFIG_SYS_BOOTCOUNT_ADDR = i2c addr which is used for 2677 the bootcounter. 2678 CONFIG_BOOTCOUNT_ALEN = address len 2679 2680- Show boot progress: 2681 CONFIG_SHOW_BOOT_PROGRESS 2682 2683 Defining this option allows to add some board- 2684 specific code (calling a user-provided function 2685 "show_boot_progress(int)") that enables you to show 2686 the system's boot progress on some display (for 2687 example, some LED's) on your board. At the moment, 2688 the following checkpoints are implemented: 2689 2690 2691Legacy uImage format: 2692 2693 Arg Where When 2694 1 common/cmd_bootm.c before attempting to boot an image 2695 -1 common/cmd_bootm.c Image header has bad magic number 2696 2 common/cmd_bootm.c Image header has correct magic number 2697 -2 common/cmd_bootm.c Image header has bad checksum 2698 3 common/cmd_bootm.c Image header has correct checksum 2699 -3 common/cmd_bootm.c Image data has bad checksum 2700 4 common/cmd_bootm.c Image data has correct checksum 2701 -4 common/cmd_bootm.c Image is for unsupported architecture 2702 5 common/cmd_bootm.c Architecture check OK 2703 -5 common/cmd_bootm.c Wrong Image Type (not kernel, multi) 2704 6 common/cmd_bootm.c Image Type check OK 2705 -6 common/cmd_bootm.c gunzip uncompression error 2706 -7 common/cmd_bootm.c Unimplemented compression type 2707 7 common/cmd_bootm.c Uncompression OK 2708 8 common/cmd_bootm.c No uncompress/copy overwrite error 2709 -9 common/cmd_bootm.c Unsupported OS (not Linux, BSD, VxWorks, QNX) 2710 2711 9 common/image.c Start initial ramdisk verification 2712 -10 common/image.c Ramdisk header has bad magic number 2713 -11 common/image.c Ramdisk header has bad checksum 2714 10 common/image.c Ramdisk header is OK 2715 -12 common/image.c Ramdisk data has bad checksum 2716 11 common/image.c Ramdisk data has correct checksum 2717 12 common/image.c Ramdisk verification complete, start loading 2718 -13 common/image.c Wrong Image Type (not PPC Linux ramdisk) 2719 13 common/image.c Start multifile image verification 2720 14 common/image.c No initial ramdisk, no multifile, continue. 2721 2722 15 arch/<arch>/lib/bootm.c All preparation done, transferring control to OS 2723 2724 -30 arch/powerpc/lib/board.c Fatal error, hang the system 2725 -31 post/post.c POST test failed, detected by post_output_backlog() 2726 -32 post/post.c POST test failed, detected by post_run_single() 2727 2728 34 common/cmd_doc.c before loading a Image from a DOC device 2729 -35 common/cmd_doc.c Bad usage of "doc" command 2730 35 common/cmd_doc.c correct usage of "doc" command 2731 -36 common/cmd_doc.c No boot device 2732 36 common/cmd_doc.c correct boot device 2733 -37 common/cmd_doc.c Unknown Chip ID on boot device 2734 37 common/cmd_doc.c correct chip ID found, device available 2735 -38 common/cmd_doc.c Read Error on boot device 2736 38 common/cmd_doc.c reading Image header from DOC device OK 2737 -39 common/cmd_doc.c Image header has bad magic number 2738 39 common/cmd_doc.c Image header has correct magic number 2739 -40 common/cmd_doc.c Error reading Image from DOC device 2740 40 common/cmd_doc.c Image header has correct magic number 2741 41 common/cmd_ide.c before loading a Image from a IDE device 2742 -42 common/cmd_ide.c Bad usage of "ide" command 2743 42 common/cmd_ide.c correct usage of "ide" command 2744 -43 common/cmd_ide.c No boot device 2745 43 common/cmd_ide.c boot device found 2746 -44 common/cmd_ide.c Device not available 2747 44 common/cmd_ide.c Device available 2748 -45 common/cmd_ide.c wrong partition selected 2749 45 common/cmd_ide.c partition selected 2750 -46 common/cmd_ide.c Unknown partition table 2751 46 common/cmd_ide.c valid partition table found 2752 -47 common/cmd_ide.c Invalid partition type 2753 47 common/cmd_ide.c correct partition type 2754 -48 common/cmd_ide.c Error reading Image Header on boot device 2755 48 common/cmd_ide.c reading Image Header from IDE device OK 2756 -49 common/cmd_ide.c Image header has bad magic number 2757 49 common/cmd_ide.c Image header has correct magic number 2758 -50 common/cmd_ide.c Image header has bad checksum 2759 50 common/cmd_ide.c Image header has correct checksum 2760 -51 common/cmd_ide.c Error reading Image from IDE device 2761 51 common/cmd_ide.c reading Image from IDE device OK 2762 52 common/cmd_nand.c before loading a Image from a NAND device 2763 -53 common/cmd_nand.c Bad usage of "nand" command 2764 53 common/cmd_nand.c correct usage of "nand" command 2765 -54 common/cmd_nand.c No boot device 2766 54 common/cmd_nand.c boot device found 2767 -55 common/cmd_nand.c Unknown Chip ID on boot device 2768 55 common/cmd_nand.c correct chip ID found, device available 2769 -56 common/cmd_nand.c Error reading Image Header on boot device 2770 56 common/cmd_nand.c reading Image Header from NAND device OK 2771 -57 common/cmd_nand.c Image header has bad magic number 2772 57 common/cmd_nand.c Image header has correct magic number 2773 -58 common/cmd_nand.c Error reading Image from NAND device 2774 58 common/cmd_nand.c reading Image from NAND device OK 2775 2776 -60 common/env_common.c Environment has a bad CRC, using default 2777 2778 64 net/eth.c starting with Ethernet configuration. 2779 -64 net/eth.c no Ethernet found. 2780 65 net/eth.c Ethernet found. 2781 2782 -80 common/cmd_net.c usage wrong 2783 80 common/cmd_net.c before calling net_loop() 2784 -81 common/cmd_net.c some error in net_loop() occurred 2785 81 common/cmd_net.c net_loop() back without error 2786 -82 common/cmd_net.c size == 0 (File with size 0 loaded) 2787 82 common/cmd_net.c trying automatic boot 2788 83 common/cmd_net.c running "source" command 2789 -83 common/cmd_net.c some error in automatic boot or "source" command 2790 84 common/cmd_net.c end without errors 2791 2792FIT uImage format: 2793 2794 Arg Where When 2795 100 common/cmd_bootm.c Kernel FIT Image has correct format 2796 -100 common/cmd_bootm.c Kernel FIT Image has incorrect format 2797 101 common/cmd_bootm.c No Kernel subimage unit name, using configuration 2798 -101 common/cmd_bootm.c Can't get configuration for kernel subimage 2799 102 common/cmd_bootm.c Kernel unit name specified 2800 -103 common/cmd_bootm.c Can't get kernel subimage node offset 2801 103 common/cmd_bootm.c Found configuration node 2802 104 common/cmd_bootm.c Got kernel subimage node offset 2803 -104 common/cmd_bootm.c Kernel subimage hash verification failed 2804 105 common/cmd_bootm.c Kernel subimage hash verification OK 2805 -105 common/cmd_bootm.c Kernel subimage is for unsupported architecture 2806 106 common/cmd_bootm.c Architecture check OK 2807 -106 common/cmd_bootm.c Kernel subimage has wrong type 2808 107 common/cmd_bootm.c Kernel subimage type OK 2809 -107 common/cmd_bootm.c Can't get kernel subimage data/size 2810 108 common/cmd_bootm.c Got kernel subimage data/size 2811 -108 common/cmd_bootm.c Wrong image type (not legacy, FIT) 2812 -109 common/cmd_bootm.c Can't get kernel subimage type 2813 -110 common/cmd_bootm.c Can't get kernel subimage comp 2814 -111 common/cmd_bootm.c Can't get kernel subimage os 2815 -112 common/cmd_bootm.c Can't get kernel subimage load address 2816 -113 common/cmd_bootm.c Image uncompress/copy overwrite error 2817 2818 120 common/image.c Start initial ramdisk verification 2819 -120 common/image.c Ramdisk FIT image has incorrect format 2820 121 common/image.c Ramdisk FIT image has correct format 2821 122 common/image.c No ramdisk subimage unit name, using configuration 2822 -122 common/image.c Can't get configuration for ramdisk subimage 2823 123 common/image.c Ramdisk unit name specified 2824 -124 common/image.c Can't get ramdisk subimage node offset 2825 125 common/image.c Got ramdisk subimage node offset 2826 -125 common/image.c Ramdisk subimage hash verification failed 2827 126 common/image.c Ramdisk subimage hash verification OK 2828 -126 common/image.c Ramdisk subimage for unsupported architecture 2829 127 common/image.c Architecture check OK 2830 -127 common/image.c Can't get ramdisk subimage data/size 2831 128 common/image.c Got ramdisk subimage data/size 2832 129 common/image.c Can't get ramdisk load address 2833 -129 common/image.c Got ramdisk load address 2834 2835 -130 common/cmd_doc.c Incorrect FIT image format 2836 131 common/cmd_doc.c FIT image format OK 2837 2838 -140 common/cmd_ide.c Incorrect FIT image format 2839 141 common/cmd_ide.c FIT image format OK 2840 2841 -150 common/cmd_nand.c Incorrect FIT image format 2842 151 common/cmd_nand.c FIT image format OK 2843 2844- legacy image format: 2845 CONFIG_IMAGE_FORMAT_LEGACY 2846 enables the legacy image format support in U-Boot. 2847 2848 Default: 2849 enabled if CONFIG_FIT_SIGNATURE is not defined. 2850 2851 CONFIG_DISABLE_IMAGE_LEGACY 2852 disable the legacy image format 2853 2854 This define is introduced, as the legacy image format is 2855 enabled per default for backward compatibility. 2856 2857- Standalone program support: 2858 CONFIG_STANDALONE_LOAD_ADDR 2859 2860 This option defines a board specific value for the 2861 address where standalone program gets loaded, thus 2862 overwriting the architecture dependent default 2863 settings. 2864 2865- Frame Buffer Address: 2866 CONFIG_FB_ADDR 2867 2868 Define CONFIG_FB_ADDR if you want to use specific 2869 address for frame buffer. This is typically the case 2870 when using a graphics controller has separate video 2871 memory. U-Boot will then place the frame buffer at 2872 the given address instead of dynamically reserving it 2873 in system RAM by calling lcd_setmem(), which grabs 2874 the memory for the frame buffer depending on the 2875 configured panel size. 2876 2877 Please see board_init_f function. 2878 2879- Automatic software updates via TFTP server 2880 CONFIG_UPDATE_TFTP 2881 CONFIG_UPDATE_TFTP_CNT_MAX 2882 CONFIG_UPDATE_TFTP_MSEC_MAX 2883 2884 These options enable and control the auto-update feature; 2885 for a more detailed description refer to doc/README.update. 2886 2887- MTD Support (mtdparts command, UBI support) 2888 CONFIG_MTD_DEVICE 2889 2890 Adds the MTD device infrastructure from the Linux kernel. 2891 Needed for mtdparts command support. 2892 2893 CONFIG_MTD_PARTITIONS 2894 2895 Adds the MTD partitioning infrastructure from the Linux 2896 kernel. Needed for UBI support. 2897 2898- UBI support 2899 CONFIG_CMD_UBI 2900 2901 Adds commands for interacting with MTD partitions formatted 2902 with the UBI flash translation layer 2903 2904 Requires also defining CONFIG_RBTREE 2905 2906 CONFIG_UBI_SILENCE_MSG 2907 2908 Make the verbose messages from UBI stop printing. This leaves 2909 warnings and errors enabled. 2910 2911 2912 CONFIG_MTD_UBI_WL_THRESHOLD 2913 This parameter defines the maximum difference between the highest 2914 erase counter value and the lowest erase counter value of eraseblocks 2915 of UBI devices. When this threshold is exceeded, UBI starts performing 2916 wear leveling by means of moving data from eraseblock with low erase 2917 counter to eraseblocks with high erase counter. 2918 2919 The default value should be OK for SLC NAND flashes, NOR flashes and 2920 other flashes which have eraseblock life-cycle 100000 or more. 2921 However, in case of MLC NAND flashes which typically have eraseblock 2922 life-cycle less than 10000, the threshold should be lessened (e.g., 2923 to 128 or 256, although it does not have to be power of 2). 2924 2925 default: 4096 2926 2927 CONFIG_MTD_UBI_BEB_LIMIT 2928 This option specifies the maximum bad physical eraseblocks UBI 2929 expects on the MTD device (per 1024 eraseblocks). If the 2930 underlying flash does not admit of bad eraseblocks (e.g. NOR 2931 flash), this value is ignored. 2932 2933 NAND datasheets often specify the minimum and maximum NVM 2934 (Number of Valid Blocks) for the flashes' endurance lifetime. 2935 The maximum expected bad eraseblocks per 1024 eraseblocks 2936 then can be calculated as "1024 * (1 - MinNVB / MaxNVB)", 2937 which gives 20 for most NANDs (MaxNVB is basically the total 2938 count of eraseblocks on the chip). 2939 2940 To put it differently, if this value is 20, UBI will try to 2941 reserve about 1.9% of physical eraseblocks for bad blocks 2942 handling. And that will be 1.9% of eraseblocks on the entire 2943 NAND chip, not just the MTD partition UBI attaches. This means 2944 that if you have, say, a NAND flash chip admits maximum 40 bad 2945 eraseblocks, and it is split on two MTD partitions of the same 2946 size, UBI will reserve 40 eraseblocks when attaching a 2947 partition. 2948 2949 default: 20 2950 2951 CONFIG_MTD_UBI_FASTMAP 2952 Fastmap is a mechanism which allows attaching an UBI device 2953 in nearly constant time. Instead of scanning the whole MTD device it 2954 only has to locate a checkpoint (called fastmap) on the device. 2955 The on-flash fastmap contains all information needed to attach 2956 the device. Using fastmap makes only sense on large devices where 2957 attaching by scanning takes long. UBI will not automatically install 2958 a fastmap on old images, but you can set the UBI parameter 2959 CONFIG_MTD_UBI_FASTMAP_AUTOCONVERT to 1 if you want so. Please note 2960 that fastmap-enabled images are still usable with UBI implementations 2961 without fastmap support. On typical flash devices the whole fastmap 2962 fits into one PEB. UBI will reserve PEBs to hold two fastmaps. 2963 2964 CONFIG_MTD_UBI_FASTMAP_AUTOCONVERT 2965 Set this parameter to enable fastmap automatically on images 2966 without a fastmap. 2967 default: 0 2968 2969 CONFIG_MTD_UBI_FM_DEBUG 2970 Enable UBI fastmap debug 2971 default: 0 2972 2973- UBIFS support 2974 CONFIG_CMD_UBIFS 2975 2976 Adds commands for interacting with UBI volumes formatted as 2977 UBIFS. UBIFS is read-only in u-boot. 2978 2979 Requires UBI support as well as CONFIG_LZO 2980 2981 CONFIG_UBIFS_SILENCE_MSG 2982 2983 Make the verbose messages from UBIFS stop printing. This leaves 2984 warnings and errors enabled. 2985 2986- SPL framework 2987 CONFIG_SPL 2988 Enable building of SPL globally. 2989 2990 CONFIG_SPL_LDSCRIPT 2991 LDSCRIPT for linking the SPL binary. 2992 2993 CONFIG_SPL_MAX_FOOTPRINT 2994 Maximum size in memory allocated to the SPL, BSS included. 2995 When defined, the linker checks that the actual memory 2996 used by SPL from _start to __bss_end does not exceed it. 2997 CONFIG_SPL_MAX_FOOTPRINT and CONFIG_SPL_BSS_MAX_SIZE 2998 must not be both defined at the same time. 2999 3000 CONFIG_SPL_MAX_SIZE 3001 Maximum size of the SPL image (text, data, rodata, and 3002 linker lists sections), BSS excluded. 3003 When defined, the linker checks that the actual size does 3004 not exceed it. 3005 3006 CONFIG_SPL_TEXT_BASE 3007 TEXT_BASE for linking the SPL binary. 3008 3009 CONFIG_SPL_RELOC_TEXT_BASE 3010 Address to relocate to. If unspecified, this is equal to 3011 CONFIG_SPL_TEXT_BASE (i.e. no relocation is done). 3012 3013 CONFIG_SPL_BSS_START_ADDR 3014 Link address for the BSS within the SPL binary. 3015 3016 CONFIG_SPL_BSS_MAX_SIZE 3017 Maximum size in memory allocated to the SPL BSS. 3018 When defined, the linker checks that the actual memory used 3019 by SPL from __bss_start to __bss_end does not exceed it. 3020 CONFIG_SPL_MAX_FOOTPRINT and CONFIG_SPL_BSS_MAX_SIZE 3021 must not be both defined at the same time. 3022 3023 CONFIG_SPL_STACK 3024 Adress of the start of the stack SPL will use 3025 3026 CONFIG_SPL_PANIC_ON_RAW_IMAGE 3027 When defined, SPL will panic() if the image it has 3028 loaded does not have a signature. 3029 Defining this is useful when code which loads images 3030 in SPL cannot guarantee that absolutely all read errors 3031 will be caught. 3032 An example is the LPC32XX MLC NAND driver, which will 3033 consider that a completely unreadable NAND block is bad, 3034 and thus should be skipped silently. 3035 3036 CONFIG_SPL_RELOC_STACK 3037 Adress of the start of the stack SPL will use after 3038 relocation. If unspecified, this is equal to 3039 CONFIG_SPL_STACK. 3040 3041 CONFIG_SYS_SPL_MALLOC_START 3042 Starting address of the malloc pool used in SPL. 3043 When this option is set the full malloc is used in SPL and 3044 it is set up by spl_init() and before that, the simple malloc() 3045 can be used if CONFIG_SYS_MALLOC_F is defined. 3046 3047 CONFIG_SYS_SPL_MALLOC_SIZE 3048 The size of the malloc pool used in SPL. 3049 3050 CONFIG_SPL_FRAMEWORK 3051 Enable the SPL framework under common/. This framework 3052 supports MMC, NAND and YMODEM loading of U-Boot and NAND 3053 NAND loading of the Linux Kernel. 3054 3055 CONFIG_SPL_OS_BOOT 3056 Enable booting directly to an OS from SPL. 3057 See also: doc/README.falcon 3058 3059 CONFIG_SPL_DISPLAY_PRINT 3060 For ARM, enable an optional function to print more information 3061 about the running system. 3062 3063 CONFIG_SPL_INIT_MINIMAL 3064 Arch init code should be built for a very small image 3065 3066 CONFIG_SYS_MMCSD_RAW_MODE_U_BOOT_PARTITION 3067 Partition on the MMC to load U-Boot from when the MMC is being 3068 used in raw mode 3069 3070 CONFIG_SYS_MMCSD_RAW_MODE_KERNEL_SECTOR 3071 Sector to load kernel uImage from when MMC is being 3072 used in raw mode (for Falcon mode) 3073 3074 CONFIG_SYS_MMCSD_RAW_MODE_ARGS_SECTOR, 3075 CONFIG_SYS_MMCSD_RAW_MODE_ARGS_SECTORS 3076 Sector and number of sectors to load kernel argument 3077 parameters from when MMC is being used in raw mode 3078 (for falcon mode) 3079 3080 CONFIG_SYS_MMCSD_FS_BOOT_PARTITION 3081 Partition on the MMC to load U-Boot from when the MMC is being 3082 used in fs mode 3083 3084 CONFIG_SPL_FS_LOAD_PAYLOAD_NAME 3085 Filename to read to load U-Boot when reading from filesystem 3086 3087 CONFIG_SPL_FS_LOAD_KERNEL_NAME 3088 Filename to read to load kernel uImage when reading 3089 from filesystem (for Falcon mode) 3090 3091 CONFIG_SPL_FS_LOAD_ARGS_NAME 3092 Filename to read to load kernel argument parameters 3093 when reading from filesystem (for Falcon mode) 3094 3095 CONFIG_SPL_MPC83XX_WAIT_FOR_NAND 3096 Set this for NAND SPL on PPC mpc83xx targets, so that 3097 start.S waits for the rest of the SPL to load before 3098 continuing (the hardware starts execution after just 3099 loading the first page rather than the full 4K). 3100 3101 CONFIG_SPL_SKIP_RELOCATE 3102 Avoid SPL relocation 3103 3104 CONFIG_SPL_NAND_BASE 3105 Include nand_base.c in the SPL. Requires 3106 CONFIG_SPL_NAND_DRIVERS. 3107 3108 CONFIG_SPL_NAND_DRIVERS 3109 SPL uses normal NAND drivers, not minimal drivers. 3110 3111 CONFIG_SPL_NAND_ECC 3112 Include standard software ECC in the SPL 3113 3114 CONFIG_SPL_NAND_SIMPLE 3115 Support for NAND boot using simple NAND drivers that 3116 expose the cmd_ctrl() interface. 3117 3118 CONFIG_SPL_UBI 3119 Support for a lightweight UBI (fastmap) scanner and 3120 loader 3121 3122 CONFIG_SPL_NAND_RAW_ONLY 3123 Support to boot only raw u-boot.bin images. Use this only 3124 if you need to save space. 3125 3126 CONFIG_SPL_COMMON_INIT_DDR 3127 Set for common ddr init with serial presence detect in 3128 SPL binary. 3129 3130 CONFIG_SYS_NAND_5_ADDR_CYCLE, CONFIG_SYS_NAND_PAGE_COUNT, 3131 CONFIG_SYS_NAND_PAGE_SIZE, CONFIG_SYS_NAND_OOBSIZE, 3132 CONFIG_SYS_NAND_BLOCK_SIZE, CONFIG_SYS_NAND_BAD_BLOCK_POS, 3133 CONFIG_SYS_NAND_ECCPOS, CONFIG_SYS_NAND_ECCSIZE, 3134 CONFIG_SYS_NAND_ECCBYTES 3135 Defines the size and behavior of the NAND that SPL uses 3136 to read U-Boot 3137 3138 CONFIG_SPL_NAND_BOOT 3139 Add support NAND boot 3140 3141 CONFIG_SYS_NAND_U_BOOT_OFFS 3142 Location in NAND to read U-Boot from 3143 3144 CONFIG_SYS_NAND_U_BOOT_DST 3145 Location in memory to load U-Boot to 3146 3147 CONFIG_SYS_NAND_U_BOOT_SIZE 3148 Size of image to load 3149 3150 CONFIG_SYS_NAND_U_BOOT_START 3151 Entry point in loaded image to jump to 3152 3153 CONFIG_SYS_NAND_HW_ECC_OOBFIRST 3154 Define this if you need to first read the OOB and then the 3155 data. This is used, for example, on davinci platforms. 3156 3157 CONFIG_SPL_OMAP3_ID_NAND 3158 Support for an OMAP3-specific set of functions to return the 3159 ID and MFR of the first attached NAND chip, if present. 3160 3161 CONFIG_SPL_RAM_DEVICE 3162 Support for running image already present in ram, in SPL binary 3163 3164 CONFIG_SPL_PAD_TO 3165 Image offset to which the SPL should be padded before appending 3166 the SPL payload. By default, this is defined as 3167 CONFIG_SPL_MAX_SIZE, or 0 if CONFIG_SPL_MAX_SIZE is undefined. 3168 CONFIG_SPL_PAD_TO must be either 0, meaning to append the SPL 3169 payload without any padding, or >= CONFIG_SPL_MAX_SIZE. 3170 3171 CONFIG_SPL_TARGET 3172 Final target image containing SPL and payload. Some SPLs 3173 use an arch-specific makefile fragment instead, for 3174 example if more than one image needs to be produced. 3175 3176 CONFIG_FIT_SPL_PRINT 3177 Printing information about a FIT image adds quite a bit of 3178 code to SPL. So this is normally disabled in SPL. Use this 3179 option to re-enable it. This will affect the output of the 3180 bootm command when booting a FIT image. 3181 3182- TPL framework 3183 CONFIG_TPL 3184 Enable building of TPL globally. 3185 3186 CONFIG_TPL_PAD_TO 3187 Image offset to which the TPL should be padded before appending 3188 the TPL payload. By default, this is defined as 3189 CONFIG_SPL_MAX_SIZE, or 0 if CONFIG_SPL_MAX_SIZE is undefined. 3190 CONFIG_SPL_PAD_TO must be either 0, meaning to append the SPL 3191 payload without any padding, or >= CONFIG_SPL_MAX_SIZE. 3192 3193- Interrupt support (PPC): 3194 3195 There are common interrupt_init() and timer_interrupt() 3196 for all PPC archs. interrupt_init() calls interrupt_init_cpu() 3197 for CPU specific initialization. interrupt_init_cpu() 3198 should set decrementer_count to appropriate value. If 3199 CPU resets decrementer automatically after interrupt 3200 (ppc4xx) it should set decrementer_count to zero. 3201 timer_interrupt() calls timer_interrupt_cpu() for CPU 3202 specific handling. If board has watchdog / status_led 3203 / other_activity_monitor it works automatically from 3204 general timer_interrupt(). 3205 3206 3207Board initialization settings: 3208------------------------------ 3209 3210During Initialization u-boot calls a number of board specific functions 3211to allow the preparation of board specific prerequisites, e.g. pin setup 3212before drivers are initialized. To enable these callbacks the 3213following configuration macros have to be defined. Currently this is 3214architecture specific, so please check arch/your_architecture/lib/board.c 3215typically in board_init_f() and board_init_r(). 3216 3217- CONFIG_BOARD_EARLY_INIT_F: Call board_early_init_f() 3218- CONFIG_BOARD_EARLY_INIT_R: Call board_early_init_r() 3219- CONFIG_BOARD_LATE_INIT: Call board_late_init() 3220- CONFIG_BOARD_POSTCLK_INIT: Call board_postclk_init() 3221 3222Configuration Settings: 3223----------------------- 3224 3225- CONFIG_SYS_SUPPORT_64BIT_DATA: Defined automatically if compiled as 64-bit. 3226 Optionally it can be defined to support 64-bit memory commands. 3227 3228- CONFIG_SYS_LONGHELP: Defined when you want long help messages included; 3229 undefine this when you're short of memory. 3230 3231- CONFIG_SYS_HELP_CMD_WIDTH: Defined when you want to override the default 3232 width of the commands listed in the 'help' command output. 3233 3234- CONFIG_SYS_PROMPT: This is what U-Boot prints on the console to 3235 prompt for user input. 3236 3237- CONFIG_SYS_CBSIZE: Buffer size for input from the Console 3238 3239- CONFIG_SYS_PBSIZE: Buffer size for Console output 3240 3241- CONFIG_SYS_MAXARGS: max. Number of arguments accepted for monitor commands 3242 3243- CONFIG_SYS_BARGSIZE: Buffer size for Boot Arguments which are passed to 3244 the application (usually a Linux kernel) when it is 3245 booted 3246 3247- CONFIG_SYS_BAUDRATE_TABLE: 3248 List of legal baudrate settings for this board. 3249 3250- CONFIG_SYS_MEMTEST_START, CONFIG_SYS_MEMTEST_END: 3251 Begin and End addresses of the area used by the 3252 simple memory test. 3253 3254- CONFIG_SYS_ALT_MEMTEST: 3255 Enable an alternate, more extensive memory test. 3256 3257- CONFIG_SYS_MEMTEST_SCRATCH: 3258 Scratch address used by the alternate memory test 3259 You only need to set this if address zero isn't writeable 3260 3261- CONFIG_SYS_MEM_RESERVE_SECURE 3262 Only implemented for ARMv8 for now. 3263 If defined, the size of CONFIG_SYS_MEM_RESERVE_SECURE memory 3264 is substracted from total RAM and won't be reported to OS. 3265 This memory can be used as secure memory. A variable 3266 gd->arch.secure_ram is used to track the location. In systems 3267 the RAM base is not zero, or RAM is divided into banks, 3268 this variable needs to be recalcuated to get the address. 3269 3270- CONFIG_SYS_MEM_TOP_HIDE: 3271 If CONFIG_SYS_MEM_TOP_HIDE is defined in the board config header, 3272 this specified memory area will get subtracted from the top 3273 (end) of RAM and won't get "touched" at all by U-Boot. By 3274 fixing up gd->ram_size the Linux kernel should gets passed 3275 the now "corrected" memory size and won't touch it either. 3276 This should work for arch/ppc and arch/powerpc. Only Linux 3277 board ports in arch/powerpc with bootwrapper support that 3278 recalculate the memory size from the SDRAM controller setup 3279 will have to get fixed in Linux additionally. 3280 3281 This option can be used as a workaround for the 440EPx/GRx 3282 CHIP 11 errata where the last 256 bytes in SDRAM shouldn't 3283 be touched. 3284 3285 WARNING: Please make sure that this value is a multiple of 3286 the Linux page size (normally 4k). If this is not the case, 3287 then the end address of the Linux memory will be located at a 3288 non page size aligned address and this could cause major 3289 problems. 3290 3291- CONFIG_SYS_LOADS_BAUD_CHANGE: 3292 Enable temporary baudrate change while serial download 3293 3294- CONFIG_SYS_SDRAM_BASE: 3295 Physical start address of SDRAM. _Must_ be 0 here. 3296 3297- CONFIG_SYS_FLASH_BASE: 3298 Physical start address of Flash memory. 3299 3300- CONFIG_SYS_MONITOR_BASE: 3301 Physical start address of boot monitor code (set by 3302 make config files to be same as the text base address 3303 (CONFIG_SYS_TEXT_BASE) used when linking) - same as 3304 CONFIG_SYS_FLASH_BASE when booting from flash. 3305 3306- CONFIG_SYS_MONITOR_LEN: 3307 Size of memory reserved for monitor code, used to 3308 determine _at_compile_time_ (!) if the environment is 3309 embedded within the U-Boot image, or in a separate 3310 flash sector. 3311 3312- CONFIG_SYS_MALLOC_LEN: 3313 Size of DRAM reserved for malloc() use. 3314 3315- CONFIG_SYS_MALLOC_F_LEN 3316 Size of the malloc() pool for use before relocation. If 3317 this is defined, then a very simple malloc() implementation 3318 will become available before relocation. The address is just 3319 below the global data, and the stack is moved down to make 3320 space. 3321 3322 This feature allocates regions with increasing addresses 3323 within the region. calloc() is supported, but realloc() 3324 is not available. free() is supported but does nothing. 3325 The memory will be freed (or in fact just forgotten) when 3326 U-Boot relocates itself. 3327 3328- CONFIG_SYS_MALLOC_SIMPLE 3329 Provides a simple and small malloc() and calloc() for those 3330 boards which do not use the full malloc in SPL (which is 3331 enabled with CONFIG_SYS_SPL_MALLOC_START). 3332 3333- CONFIG_SYS_NONCACHED_MEMORY: 3334 Size of non-cached memory area. This area of memory will be 3335 typically located right below the malloc() area and mapped 3336 uncached in the MMU. This is useful for drivers that would 3337 otherwise require a lot of explicit cache maintenance. For 3338 some drivers it's also impossible to properly maintain the 3339 cache. For example if the regions that need to be flushed 3340 are not a multiple of the cache-line size, *and* padding 3341 cannot be allocated between the regions to align them (i.e. 3342 if the HW requires a contiguous array of regions, and the 3343 size of each region is not cache-aligned), then a flush of 3344 one region may result in overwriting data that hardware has 3345 written to another region in the same cache-line. This can 3346 happen for example in network drivers where descriptors for 3347 buffers are typically smaller than the CPU cache-line (e.g. 3348 16 bytes vs. 32 or 64 bytes). 3349 3350 Non-cached memory is only supported on 32-bit ARM at present. 3351 3352- CONFIG_SYS_BOOTM_LEN: 3353 Normally compressed uImages are limited to an 3354 uncompressed size of 8 MBytes. If this is not enough, 3355 you can define CONFIG_SYS_BOOTM_LEN in your board config file 3356 to adjust this setting to your needs. 3357 3358- CONFIG_SYS_BOOTMAPSZ: 3359 Maximum size of memory mapped by the startup code of 3360 the Linux kernel; all data that must be processed by 3361 the Linux kernel (bd_info, boot arguments, FDT blob if 3362 used) must be put below this limit, unless "bootm_low" 3363 environment variable is defined and non-zero. In such case 3364 all data for the Linux kernel must be between "bootm_low" 3365 and "bootm_low" + CONFIG_SYS_BOOTMAPSZ. The environment 3366 variable "bootm_mapsize" will override the value of 3367 CONFIG_SYS_BOOTMAPSZ. If CONFIG_SYS_BOOTMAPSZ is undefined, 3368 then the value in "bootm_size" will be used instead. 3369 3370- CONFIG_SYS_BOOT_RAMDISK_HIGH: 3371 Enable initrd_high functionality. If defined then the 3372 initrd_high feature is enabled and the bootm ramdisk subcommand 3373 is enabled. 3374 3375- CONFIG_SYS_BOOT_GET_CMDLINE: 3376 Enables allocating and saving kernel cmdline in space between 3377 "bootm_low" and "bootm_low" + BOOTMAPSZ. 3378 3379- CONFIG_SYS_BOOT_GET_KBD: 3380 Enables allocating and saving a kernel copy of the bd_info in 3381 space between "bootm_low" and "bootm_low" + BOOTMAPSZ. 3382 3383- CONFIG_SYS_MAX_FLASH_BANKS: 3384 Max number of Flash memory banks 3385 3386- CONFIG_SYS_MAX_FLASH_SECT: 3387 Max number of sectors on a Flash chip 3388 3389- CONFIG_SYS_FLASH_ERASE_TOUT: 3390 Timeout for Flash erase operations (in ms) 3391 3392- CONFIG_SYS_FLASH_WRITE_TOUT: 3393 Timeout for Flash write operations (in ms) 3394 3395- CONFIG_SYS_FLASH_LOCK_TOUT 3396 Timeout for Flash set sector lock bit operation (in ms) 3397 3398- CONFIG_SYS_FLASH_UNLOCK_TOUT 3399 Timeout for Flash clear lock bits operation (in ms) 3400 3401- CONFIG_SYS_FLASH_PROTECTION 3402 If defined, hardware flash sectors protection is used 3403 instead of U-Boot software protection. 3404 3405- CONFIG_SYS_DIRECT_FLASH_TFTP: 3406 3407 Enable TFTP transfers directly to flash memory; 3408 without this option such a download has to be 3409 performed in two steps: (1) download to RAM, and (2) 3410 copy from RAM to flash. 3411 3412 The two-step approach is usually more reliable, since 3413 you can check if the download worked before you erase 3414 the flash, but in some situations (when system RAM is 3415 too limited to allow for a temporary copy of the 3416 downloaded image) this option may be very useful. 3417 3418- CONFIG_SYS_FLASH_CFI: 3419 Define if the flash driver uses extra elements in the 3420 common flash structure for storing flash geometry. 3421 3422- CONFIG_FLASH_CFI_DRIVER 3423 This option also enables the building of the cfi_flash driver 3424 in the drivers directory 3425 3426- CONFIG_FLASH_CFI_MTD 3427 This option enables the building of the cfi_mtd driver 3428 in the drivers directory. The driver exports CFI flash 3429 to the MTD layer. 3430 3431- CONFIG_SYS_FLASH_USE_BUFFER_WRITE 3432 Use buffered writes to flash. 3433 3434- CONFIG_FLASH_SPANSION_S29WS_N 3435 s29ws-n MirrorBit flash has non-standard addresses for buffered 3436 write commands. 3437 3438- CONFIG_SYS_FLASH_QUIET_TEST 3439 If this option is defined, the common CFI flash doesn't 3440 print it's warning upon not recognized FLASH banks. This 3441 is useful, if some of the configured banks are only 3442 optionally available. 3443 3444- CONFIG_FLASH_SHOW_PROGRESS 3445 If defined (must be an integer), print out countdown 3446 digits and dots. Recommended value: 45 (9..1) for 80 3447 column displays, 15 (3..1) for 40 column displays. 3448 3449- CONFIG_FLASH_VERIFY 3450 If defined, the content of the flash (destination) is compared 3451 against the source after the write operation. An error message 3452 will be printed when the contents are not identical. 3453 Please note that this option is useless in nearly all cases, 3454 since such flash programming errors usually are detected earlier 3455 while unprotecting/erasing/programming. Please only enable 3456 this option if you really know what you are doing. 3457 3458- CONFIG_SYS_RX_ETH_BUFFER: 3459 Defines the number of Ethernet receive buffers. On some 3460 Ethernet controllers it is recommended to set this value 3461 to 8 or even higher (EEPRO100 or 405 EMAC), since all 3462 buffers can be full shortly after enabling the interface 3463 on high Ethernet traffic. 3464 Defaults to 4 if not defined. 3465 3466- CONFIG_ENV_MAX_ENTRIES 3467 3468 Maximum number of entries in the hash table that is used 3469 internally to store the environment settings. The default 3470 setting is supposed to be generous and should work in most 3471 cases. This setting can be used to tune behaviour; see 3472 lib/hashtable.c for details. 3473 3474- CONFIG_ENV_FLAGS_LIST_DEFAULT 3475- CONFIG_ENV_FLAGS_LIST_STATIC 3476 Enable validation of the values given to environment variables when 3477 calling env set. Variables can be restricted to only decimal, 3478 hexadecimal, or boolean. If CONFIG_CMD_NET is also defined, 3479 the variables can also be restricted to IP address or MAC address. 3480 3481 The format of the list is: 3482 type_attribute = [s|d|x|b|i|m] 3483 access_attribute = [a|r|o|c] 3484 attributes = type_attribute[access_attribute] 3485 entry = variable_name[:attributes] 3486 list = entry[,list] 3487 3488 The type attributes are: 3489 s - String (default) 3490 d - Decimal 3491 x - Hexadecimal 3492 b - Boolean ([1yYtT|0nNfF]) 3493 i - IP address 3494 m - MAC address 3495 3496 The access attributes are: 3497 a - Any (default) 3498 r - Read-only 3499 o - Write-once 3500 c - Change-default 3501 3502 - CONFIG_ENV_FLAGS_LIST_DEFAULT 3503 Define this to a list (string) to define the ".flags" 3504 environment variable in the default or embedded environment. 3505 3506 - CONFIG_ENV_FLAGS_LIST_STATIC 3507 Define this to a list (string) to define validation that 3508 should be done if an entry is not found in the ".flags" 3509 environment variable. To override a setting in the static 3510 list, simply add an entry for the same variable name to the 3511 ".flags" variable. 3512 3513 If CONFIG_REGEX is defined, the variable_name above is evaluated as a 3514 regular expression. This allows multiple variables to define the same 3515 flags without explicitly listing them for each variable. 3516 3517- CONFIG_ENV_ACCESS_IGNORE_FORCE 3518 If defined, don't allow the -f switch to env set override variable 3519 access flags. 3520 3521- CONFIG_USE_STDINT 3522 If stdint.h is available with your toolchain you can define this 3523 option to enable it. You can provide option 'USE_STDINT=1' when 3524 building U-Boot to enable this. 3525 3526The following definitions that deal with the placement and management 3527of environment data (variable area); in general, we support the 3528following configurations: 3529 3530- CONFIG_BUILD_ENVCRC: 3531 3532 Builds up envcrc with the target environment so that external utils 3533 may easily extract it and embed it in final U-Boot images. 3534 3535- CONFIG_ENV_IS_IN_FLASH: 3536 3537 Define this if the environment is in flash memory. 3538 3539 a) The environment occupies one whole flash sector, which is 3540 "embedded" in the text segment with the U-Boot code. This 3541 happens usually with "bottom boot sector" or "top boot 3542 sector" type flash chips, which have several smaller 3543 sectors at the start or the end. For instance, such a 3544 layout can have sector sizes of 8, 2x4, 16, Nx32 kB. In 3545 such a case you would place the environment in one of the 3546 4 kB sectors - with U-Boot code before and after it. With 3547 "top boot sector" type flash chips, you would put the 3548 environment in one of the last sectors, leaving a gap 3549 between U-Boot and the environment. 3550 3551 - CONFIG_ENV_OFFSET: 3552 3553 Offset of environment data (variable area) to the 3554 beginning of flash memory; for instance, with bottom boot 3555 type flash chips the second sector can be used: the offset 3556 for this sector is given here. 3557 3558 CONFIG_ENV_OFFSET is used relative to CONFIG_SYS_FLASH_BASE. 3559 3560 - CONFIG_ENV_ADDR: 3561 3562 This is just another way to specify the start address of 3563 the flash sector containing the environment (instead of 3564 CONFIG_ENV_OFFSET). 3565 3566 - CONFIG_ENV_SECT_SIZE: 3567 3568 Size of the sector containing the environment. 3569 3570 3571 b) Sometimes flash chips have few, equal sized, BIG sectors. 3572 In such a case you don't want to spend a whole sector for 3573 the environment. 3574 3575 - CONFIG_ENV_SIZE: 3576 3577 If you use this in combination with CONFIG_ENV_IS_IN_FLASH 3578 and CONFIG_ENV_SECT_SIZE, you can specify to use only a part 3579 of this flash sector for the environment. This saves 3580 memory for the RAM copy of the environment. 3581 3582 It may also save flash memory if you decide to use this 3583 when your environment is "embedded" within U-Boot code, 3584 since then the remainder of the flash sector could be used 3585 for U-Boot code. It should be pointed out that this is 3586 STRONGLY DISCOURAGED from a robustness point of view: 3587 updating the environment in flash makes it always 3588 necessary to erase the WHOLE sector. If something goes 3589 wrong before the contents has been restored from a copy in 3590 RAM, your target system will be dead. 3591 3592 - CONFIG_ENV_ADDR_REDUND 3593 CONFIG_ENV_SIZE_REDUND 3594 3595 These settings describe a second storage area used to hold 3596 a redundant copy of the environment data, so that there is 3597 a valid backup copy in case there is a power failure during 3598 a "saveenv" operation. 3599 3600BE CAREFUL! Any changes to the flash layout, and some changes to the 3601source code will make it necessary to adapt <board>/u-boot.lds* 3602accordingly! 3603 3604 3605- CONFIG_ENV_IS_IN_NVRAM: 3606 3607 Define this if you have some non-volatile memory device 3608 (NVRAM, battery buffered SRAM) which you want to use for the 3609 environment. 3610 3611 - CONFIG_ENV_ADDR: 3612 - CONFIG_ENV_SIZE: 3613 3614 These two #defines are used to determine the memory area you 3615 want to use for environment. It is assumed that this memory 3616 can just be read and written to, without any special 3617 provision. 3618 3619BE CAREFUL! The first access to the environment happens quite early 3620in U-Boot initialization (when we try to get the setting of for the 3621console baudrate). You *MUST* have mapped your NVRAM area then, or 3622U-Boot will hang. 3623 3624Please note that even with NVRAM we still use a copy of the 3625environment in RAM: we could work on NVRAM directly, but we want to 3626keep settings there always unmodified except somebody uses "saveenv" 3627to save the current settings. 3628 3629 3630- CONFIG_ENV_IS_IN_EEPROM: 3631 3632 Use this if you have an EEPROM or similar serial access 3633 device and a driver for it. 3634 3635 - CONFIG_ENV_OFFSET: 3636 - CONFIG_ENV_SIZE: 3637 3638 These two #defines specify the offset and size of the 3639 environment area within the total memory of your EEPROM. 3640 3641 - CONFIG_SYS_I2C_EEPROM_ADDR: 3642 If defined, specified the chip address of the EEPROM device. 3643 The default address is zero. 3644 3645 - CONFIG_SYS_I2C_EEPROM_BUS: 3646 If defined, specified the i2c bus of the EEPROM device. 3647 3648 - CONFIG_SYS_EEPROM_PAGE_WRITE_BITS: 3649 If defined, the number of bits used to address bytes in a 3650 single page in the EEPROM device. A 64 byte page, for example 3651 would require six bits. 3652 3653 - CONFIG_SYS_EEPROM_PAGE_WRITE_DELAY_MS: 3654 If defined, the number of milliseconds to delay between 3655 page writes. The default is zero milliseconds. 3656 3657 - CONFIG_SYS_I2C_EEPROM_ADDR_LEN: 3658 The length in bytes of the EEPROM memory array address. Note 3659 that this is NOT the chip address length! 3660 3661 - CONFIG_SYS_I2C_EEPROM_ADDR_OVERFLOW: 3662 EEPROM chips that implement "address overflow" are ones 3663 like Catalyst 24WC04/08/16 which has 9/10/11 bits of 3664 address and the extra bits end up in the "chip address" bit 3665 slots. This makes a 24WC08 (1Kbyte) chip look like four 256 3666 byte chips. 3667 3668 Note that we consider the length of the address field to 3669 still be one byte because the extra address bits are hidden 3670 in the chip address. 3671 3672 - CONFIG_SYS_EEPROM_SIZE: 3673 The size in bytes of the EEPROM device. 3674 3675 - CONFIG_ENV_EEPROM_IS_ON_I2C 3676 define this, if you have I2C and SPI activated, and your 3677 EEPROM, which holds the environment, is on the I2C bus. 3678 3679 - CONFIG_I2C_ENV_EEPROM_BUS 3680 if you have an Environment on an EEPROM reached over 3681 I2C muxes, you can define here, how to reach this 3682 EEPROM. For example: 3683 3684 #define CONFIG_I2C_ENV_EEPROM_BUS 1 3685 3686 EEPROM which holds the environment, is reached over 3687 a pca9547 i2c mux with address 0x70, channel 3. 3688 3689- CONFIG_ENV_IS_IN_DATAFLASH: 3690 3691 Define this if you have a DataFlash memory device which you 3692 want to use for the environment. 3693 3694 - CONFIG_ENV_OFFSET: 3695 - CONFIG_ENV_ADDR: 3696 - CONFIG_ENV_SIZE: 3697 3698 These three #defines specify the offset and size of the 3699 environment area within the total memory of your DataFlash placed 3700 at the specified address. 3701 3702- CONFIG_ENV_IS_IN_SPI_FLASH: 3703 3704 Define this if you have a SPI Flash memory device which you 3705 want to use for the environment. 3706 3707 - CONFIG_ENV_OFFSET: 3708 - CONFIG_ENV_SIZE: 3709 3710 These two #defines specify the offset and size of the 3711 environment area within the SPI Flash. CONFIG_ENV_OFFSET must be 3712 aligned to an erase sector boundary. 3713 3714 - CONFIG_ENV_SECT_SIZE: 3715 3716 Define the SPI flash's sector size. 3717 3718 - CONFIG_ENV_OFFSET_REDUND (optional): 3719 3720 This setting describes a second storage area of CONFIG_ENV_SIZE 3721 size used to hold a redundant copy of the environment data, so 3722 that there is a valid backup copy in case there is a power failure 3723 during a "saveenv" operation. CONFIG_ENV_OFFSET_REDUND must be 3724 aligned to an erase sector boundary. 3725 3726 - CONFIG_ENV_SPI_BUS (optional): 3727 - CONFIG_ENV_SPI_CS (optional): 3728 3729 Define the SPI bus and chip select. If not defined they will be 0. 3730 3731 - CONFIG_ENV_SPI_MAX_HZ (optional): 3732 3733 Define the SPI max work clock. If not defined then use 1MHz. 3734 3735 - CONFIG_ENV_SPI_MODE (optional): 3736 3737 Define the SPI work mode. If not defined then use SPI_MODE_3. 3738 3739- CONFIG_ENV_IS_IN_REMOTE: 3740 3741 Define this if you have a remote memory space which you 3742 want to use for the local device's environment. 3743 3744 - CONFIG_ENV_ADDR: 3745 - CONFIG_ENV_SIZE: 3746 3747 These two #defines specify the address and size of the 3748 environment area within the remote memory space. The 3749 local device can get the environment from remote memory 3750 space by SRIO or PCIE links. 3751 3752BE CAREFUL! For some special cases, the local device can not use 3753"saveenv" command. For example, the local device will get the 3754environment stored in a remote NOR flash by SRIO or PCIE link, 3755but it can not erase, write this NOR flash by SRIO or PCIE interface. 3756 3757- CONFIG_ENV_IS_IN_NAND: 3758 3759 Define this if you have a NAND device which you want to use 3760 for the environment. 3761 3762 - CONFIG_ENV_OFFSET: 3763 - CONFIG_ENV_SIZE: 3764 3765 These two #defines specify the offset and size of the environment 3766 area within the first NAND device. CONFIG_ENV_OFFSET must be 3767 aligned to an erase block boundary. 3768 3769 - CONFIG_ENV_OFFSET_REDUND (optional): 3770 3771 This setting describes a second storage area of CONFIG_ENV_SIZE 3772 size used to hold a redundant copy of the environment data, so 3773 that there is a valid backup copy in case there is a power failure 3774 during a "saveenv" operation. CONFIG_ENV_OFFSET_REDUND must be 3775 aligned to an erase block boundary. 3776 3777 - CONFIG_ENV_RANGE (optional): 3778 3779 Specifies the length of the region in which the environment 3780 can be written. This should be a multiple of the NAND device's 3781 block size. Specifying a range with more erase blocks than 3782 are needed to hold CONFIG_ENV_SIZE allows bad blocks within 3783 the range to be avoided. 3784 3785 - CONFIG_ENV_OFFSET_OOB (optional): 3786 3787 Enables support for dynamically retrieving the offset of the 3788 environment from block zero's out-of-band data. The 3789 "nand env.oob" command can be used to record this offset. 3790 Currently, CONFIG_ENV_OFFSET_REDUND is not supported when 3791 using CONFIG_ENV_OFFSET_OOB. 3792 3793- CONFIG_NAND_ENV_DST 3794 3795 Defines address in RAM to which the nand_spl code should copy the 3796 environment. If redundant environment is used, it will be copied to 3797 CONFIG_NAND_ENV_DST + CONFIG_ENV_SIZE. 3798 3799- CONFIG_ENV_IS_IN_UBI: 3800 3801 Define this if you have an UBI volume that you want to use for the 3802 environment. This has the benefit of wear-leveling the environment 3803 accesses, which is important on NAND. 3804 3805 - CONFIG_ENV_UBI_PART: 3806 3807 Define this to a string that is the mtd partition containing the UBI. 3808 3809 - CONFIG_ENV_UBI_VOLUME: 3810 3811 Define this to the name of the volume that you want to store the 3812 environment in. 3813 3814 - CONFIG_ENV_UBI_VOLUME_REDUND: 3815 3816 Define this to the name of another volume to store a second copy of 3817 the environment in. This will enable redundant environments in UBI. 3818 It is assumed that both volumes are in the same MTD partition. 3819 3820 - CONFIG_UBI_SILENCE_MSG 3821 - CONFIG_UBIFS_SILENCE_MSG 3822 3823 You will probably want to define these to avoid a really noisy system 3824 when storing the env in UBI. 3825 3826- CONFIG_ENV_IS_IN_FAT: 3827 Define this if you want to use the FAT file system for the environment. 3828 3829 - FAT_ENV_INTERFACE: 3830 3831 Define this to a string that is the name of the block device. 3832 3833 - FAT_ENV_DEVICE_AND_PART: 3834 3835 Define this to a string to specify the partition of the device. It can 3836 be as following: 3837 3838 "D:P", "D:0", "D", "D:" or "D:auto" (D, P are integers. And P >= 1) 3839 - "D:P": device D partition P. Error occurs if device D has no 3840 partition table. 3841 - "D:0": device D. 3842 - "D" or "D:": device D partition 1 if device D has partition 3843 table, or the whole device D if has no partition 3844 table. 3845 - "D:auto": first partition in device D with bootable flag set. 3846 If none, first valid partition in device D. If no 3847 partition table then means device D. 3848 3849 - FAT_ENV_FILE: 3850 3851 It's a string of the FAT file name. This file use to store the 3852 environment. 3853 3854 - CONFIG_FAT_WRITE: 3855 This must be enabled. Otherwise it cannot save the environment file. 3856 3857- CONFIG_ENV_IS_IN_MMC: 3858 3859 Define this if you have an MMC device which you want to use for the 3860 environment. 3861 3862 - CONFIG_SYS_MMC_ENV_DEV: 3863 3864 Specifies which MMC device the environment is stored in. 3865 3866 - CONFIG_SYS_MMC_ENV_PART (optional): 3867 3868 Specifies which MMC partition the environment is stored in. If not 3869 set, defaults to partition 0, the user area. Common values might be 3870 1 (first MMC boot partition), 2 (second MMC boot partition). 3871 3872 - CONFIG_ENV_OFFSET: 3873 - CONFIG_ENV_SIZE: 3874 3875 These two #defines specify the offset and size of the environment 3876 area within the specified MMC device. 3877 3878 If offset is positive (the usual case), it is treated as relative to 3879 the start of the MMC partition. If offset is negative, it is treated 3880 as relative to the end of the MMC partition. This can be useful if 3881 your board may be fitted with different MMC devices, which have 3882 different sizes for the MMC partitions, and you always want the 3883 environment placed at the very end of the partition, to leave the 3884 maximum possible space before it, to store other data. 3885 3886 These two values are in units of bytes, but must be aligned to an 3887 MMC sector boundary. 3888 3889 - CONFIG_ENV_OFFSET_REDUND (optional): 3890 3891 Specifies a second storage area, of CONFIG_ENV_SIZE size, used to 3892 hold a redundant copy of the environment data. This provides a 3893 valid backup copy in case the other copy is corrupted, e.g. due 3894 to a power failure during a "saveenv" operation. 3895 3896 This value may also be positive or negative; this is handled in the 3897 same way as CONFIG_ENV_OFFSET. 3898 3899 This value is also in units of bytes, but must also be aligned to 3900 an MMC sector boundary. 3901 3902 - CONFIG_ENV_SIZE_REDUND (optional): 3903 3904 This value need not be set, even when CONFIG_ENV_OFFSET_REDUND is 3905 set. If this value is set, it must be set to the same value as 3906 CONFIG_ENV_SIZE. 3907 3908- CONFIG_SYS_SPI_INIT_OFFSET 3909 3910 Defines offset to the initial SPI buffer area in DPRAM. The 3911 area is used at an early stage (ROM part) if the environment 3912 is configured to reside in the SPI EEPROM: We need a 520 byte 3913 scratch DPRAM area. It is used between the two initialization 3914 calls (spi_init_f() and spi_init_r()). A value of 0xB00 seems 3915 to be a good choice since it makes it far enough from the 3916 start of the data area as well as from the stack pointer. 3917 3918Please note that the environment is read-only until the monitor 3919has been relocated to RAM and a RAM copy of the environment has been 3920created; also, when using EEPROM you will have to use getenv_f() 3921until then to read environment variables. 3922 3923The environment is protected by a CRC32 checksum. Before the monitor 3924is relocated into RAM, as a result of a bad CRC you will be working 3925with the compiled-in default environment - *silently*!!! [This is 3926necessary, because the first environment variable we need is the 3927"baudrate" setting for the console - if we have a bad CRC, we don't 3928have any device yet where we could complain.] 3929 3930Note: once the monitor has been relocated, then it will complain if 3931the default environment is used; a new CRC is computed as soon as you 3932use the "saveenv" command to store a valid environment. 3933 3934- CONFIG_SYS_FAULT_ECHO_LINK_DOWN: 3935 Echo the inverted Ethernet link state to the fault LED. 3936 3937 Note: If this option is active, then CONFIG_SYS_FAULT_MII_ADDR 3938 also needs to be defined. 3939 3940- CONFIG_SYS_FAULT_MII_ADDR: 3941 MII address of the PHY to check for the Ethernet link state. 3942 3943- CONFIG_NS16550_MIN_FUNCTIONS: 3944 Define this if you desire to only have use of the NS16550_init 3945 and NS16550_putc functions for the serial driver located at 3946 drivers/serial/ns16550.c. This option is useful for saving 3947 space for already greatly restricted images, including but not 3948 limited to NAND_SPL configurations. 3949 3950- CONFIG_DISPLAY_BOARDINFO 3951 Display information about the board that U-Boot is running on 3952 when U-Boot starts up. The board function checkboard() is called 3953 to do this. 3954 3955- CONFIG_DISPLAY_BOARDINFO_LATE 3956 Similar to the previous option, but display this information 3957 later, once stdio is running and output goes to the LCD, if 3958 present. 3959 3960- CONFIG_BOARD_SIZE_LIMIT: 3961 Maximum size of the U-Boot image. When defined, the 3962 build system checks that the actual size does not 3963 exceed it. 3964 3965Low Level (hardware related) configuration options: 3966--------------------------------------------------- 3967 3968- CONFIG_SYS_CACHELINE_SIZE: 3969 Cache Line Size of the CPU. 3970 3971- CONFIG_SYS_DEFAULT_IMMR: 3972 Default address of the IMMR after system reset. 3973 3974 Needed on some 8260 systems (MPC8260ADS, PQ2FADS-ZU, 3975 and RPXsuper) to be able to adjust the position of 3976 the IMMR register after a reset. 3977 3978- CONFIG_SYS_CCSRBAR_DEFAULT: 3979 Default (power-on reset) physical address of CCSR on Freescale 3980 PowerPC SOCs. 3981 3982- CONFIG_SYS_CCSRBAR: 3983 Virtual address of CCSR. On a 32-bit build, this is typically 3984 the same value as CONFIG_SYS_CCSRBAR_DEFAULT. 3985 3986 CONFIG_SYS_DEFAULT_IMMR must also be set to this value, 3987 for cross-platform code that uses that macro instead. 3988 3989- CONFIG_SYS_CCSRBAR_PHYS: 3990 Physical address of CCSR. CCSR can be relocated to a new 3991 physical address, if desired. In this case, this macro should 3992 be set to that address. Otherwise, it should be set to the 3993 same value as CONFIG_SYS_CCSRBAR_DEFAULT. For example, CCSR 3994 is typically relocated on 36-bit builds. It is recommended 3995 that this macro be defined via the _HIGH and _LOW macros: 3996 3997 #define CONFIG_SYS_CCSRBAR_PHYS ((CONFIG_SYS_CCSRBAR_PHYS_HIGH 3998 * 1ull) << 32 | CONFIG_SYS_CCSRBAR_PHYS_LOW) 3999 4000- CONFIG_SYS_CCSRBAR_PHYS_HIGH: 4001 Bits 33-36 of CONFIG_SYS_CCSRBAR_PHYS. This value is typically 4002 either 0 (32-bit build) or 0xF (36-bit build). This macro is 4003 used in assembly code, so it must not contain typecasts or 4004 integer size suffixes (e.g. "ULL"). 4005 4006- CONFIG_SYS_CCSRBAR_PHYS_LOW: 4007 Lower 32-bits of CONFIG_SYS_CCSRBAR_PHYS. This macro is 4008 used in assembly code, so it must not contain typecasts or 4009 integer size suffixes (e.g. "ULL"). 4010 4011- CONFIG_SYS_CCSR_DO_NOT_RELOCATE: 4012 If this macro is defined, then CONFIG_SYS_CCSRBAR_PHYS will be 4013 forced to a value that ensures that CCSR is not relocated. 4014 4015- Floppy Disk Support: 4016 CONFIG_SYS_FDC_DRIVE_NUMBER 4017 4018 the default drive number (default value 0) 4019 4020 CONFIG_SYS_ISA_IO_STRIDE 4021 4022 defines the spacing between FDC chipset registers 4023 (default value 1) 4024 4025 CONFIG_SYS_ISA_IO_OFFSET 4026 4027 defines the offset of register from address. It 4028 depends on which part of the data bus is connected to 4029 the FDC chipset. (default value 0) 4030 4031 If CONFIG_SYS_ISA_IO_STRIDE CONFIG_SYS_ISA_IO_OFFSET and 4032 CONFIG_SYS_FDC_DRIVE_NUMBER are undefined, they take their 4033 default value. 4034 4035 if CONFIG_SYS_FDC_HW_INIT is defined, then the function 4036 fdc_hw_init() is called at the beginning of the FDC 4037 setup. fdc_hw_init() must be provided by the board 4038 source code. It is used to make hardware-dependent 4039 initializations. 4040 4041- CONFIG_IDE_AHB: 4042 Most IDE controllers were designed to be connected with PCI 4043 interface. Only few of them were designed for AHB interface. 4044 When software is doing ATA command and data transfer to 4045 IDE devices through IDE-AHB controller, some additional 4046 registers accessing to these kind of IDE-AHB controller 4047 is required. 4048 4049- CONFIG_SYS_IMMR: Physical address of the Internal Memory. 4050 DO NOT CHANGE unless you know exactly what you're 4051 doing! (11-4) [MPC8xx/82xx systems only] 4052 4053- CONFIG_SYS_INIT_RAM_ADDR: 4054 4055 Start address of memory area that can be used for 4056 initial data and stack; please note that this must be 4057 writable memory that is working WITHOUT special 4058 initialization, i. e. you CANNOT use normal RAM which 4059 will become available only after programming the 4060 memory controller and running certain initialization 4061 sequences. 4062 4063 U-Boot uses the following memory types: 4064 - MPC8xx and MPC8260: IMMR (internal memory of the CPU) 4065 - MPC824X: data cache 4066 - PPC4xx: data cache 4067 4068- CONFIG_SYS_GBL_DATA_OFFSET: 4069 4070 Offset of the initial data structure in the memory 4071 area defined by CONFIG_SYS_INIT_RAM_ADDR. Usually 4072 CONFIG_SYS_GBL_DATA_OFFSET is chosen such that the initial 4073 data is located at the end of the available space 4074 (sometimes written as (CONFIG_SYS_INIT_RAM_SIZE - 4075 GENERATED_GBL_DATA_SIZE), and the initial stack is just 4076 below that area (growing from (CONFIG_SYS_INIT_RAM_ADDR + 4077 CONFIG_SYS_GBL_DATA_OFFSET) downward. 4078 4079 Note: 4080 On the MPC824X (or other systems that use the data 4081 cache for initial memory) the address chosen for 4082 CONFIG_SYS_INIT_RAM_ADDR is basically arbitrary - it must 4083 point to an otherwise UNUSED address space between 4084 the top of RAM and the start of the PCI space. 4085 4086- CONFIG_SYS_SIUMCR: SIU Module Configuration (11-6) 4087 4088- CONFIG_SYS_SYPCR: System Protection Control (11-9) 4089 4090- CONFIG_SYS_TBSCR: Time Base Status and Control (11-26) 4091 4092- CONFIG_SYS_PISCR: Periodic Interrupt Status and Control (11-31) 4093 4094- CONFIG_SYS_PLPRCR: PLL, Low-Power, and Reset Control Register (15-30) 4095 4096- CONFIG_SYS_SCCR: System Clock and reset Control Register (15-27) 4097 4098- CONFIG_SYS_OR_TIMING_SDRAM: 4099 SDRAM timing 4100 4101- CONFIG_SYS_MAMR_PTA: 4102 periodic timer for refresh 4103 4104- CONFIG_SYS_DER: Debug Event Register (37-47) 4105 4106- FLASH_BASE0_PRELIM, FLASH_BASE1_PRELIM, CONFIG_SYS_REMAP_OR_AM, 4107 CONFIG_SYS_PRELIM_OR_AM, CONFIG_SYS_OR_TIMING_FLASH, CONFIG_SYS_OR0_REMAP, 4108 CONFIG_SYS_OR0_PRELIM, CONFIG_SYS_BR0_PRELIM, CONFIG_SYS_OR1_REMAP, CONFIG_SYS_OR1_PRELIM, 4109 CONFIG_SYS_BR1_PRELIM: 4110 Memory Controller Definitions: BR0/1 and OR0/1 (FLASH) 4111 4112- SDRAM_BASE2_PRELIM, SDRAM_BASE3_PRELIM, SDRAM_MAX_SIZE, 4113 CONFIG_SYS_OR_TIMING_SDRAM, CONFIG_SYS_OR2_PRELIM, CONFIG_SYS_BR2_PRELIM, 4114 CONFIG_SYS_OR3_PRELIM, CONFIG_SYS_BR3_PRELIM: 4115 Memory Controller Definitions: BR2/3 and OR2/3 (SDRAM) 4116 4117- CONFIG_SYS_MAMR_PTA, CONFIG_SYS_MPTPR_2BK_4K, CONFIG_SYS_MPTPR_1BK_4K, CONFIG_SYS_MPTPR_2BK_8K, 4118 CONFIG_SYS_MPTPR_1BK_8K, CONFIG_SYS_MAMR_8COL, CONFIG_SYS_MAMR_9COL: 4119 Machine Mode Register and Memory Periodic Timer 4120 Prescaler definitions (SDRAM timing) 4121 4122- CONFIG_SYS_I2C_UCODE_PATCH, CONFIG_SYS_I2C_DPMEM_OFFSET [0x1FC0]: 4123 enable I2C microcode relocation patch (MPC8xx); 4124 define relocation offset in DPRAM [DSP2] 4125 4126- CONFIG_SYS_SMC_UCODE_PATCH, CONFIG_SYS_SMC_DPMEM_OFFSET [0x1FC0]: 4127 enable SMC microcode relocation patch (MPC8xx); 4128 define relocation offset in DPRAM [SMC1] 4129 4130- CONFIG_SYS_SPI_UCODE_PATCH, CONFIG_SYS_SPI_DPMEM_OFFSET [0x1FC0]: 4131 enable SPI microcode relocation patch (MPC8xx); 4132 define relocation offset in DPRAM [SCC4] 4133 4134- CONFIG_SYS_CPM_POST_WORD_ADDR: (MPC8xx, MPC8260 only) 4135 Offset of the bootmode word in DPRAM used by post 4136 (Power On Self Tests). This definition overrides 4137 #define'd default value in commproc.h resp. 4138 cpm_8260.h. 4139 4140- CONFIG_SYS_PCI_SLV_MEM_LOCAL, CONFIG_SYS_PCI_SLV_MEM_BUS, CONFIG_SYS_PICMR0_MASK_ATTRIB, 4141 CONFIG_SYS_PCI_MSTR0_LOCAL, CONFIG_SYS_PCIMSK0_MASK, CONFIG_SYS_PCI_MSTR1_LOCAL, 4142 CONFIG_SYS_PCIMSK1_MASK, CONFIG_SYS_PCI_MSTR_MEM_LOCAL, CONFIG_SYS_PCI_MSTR_MEM_BUS, 4143 CONFIG_SYS_CPU_PCI_MEM_START, CONFIG_SYS_PCI_MSTR_MEM_SIZE, CONFIG_SYS_POCMR0_MASK_ATTRIB, 4144 CONFIG_SYS_PCI_MSTR_MEMIO_LOCAL, CONFIG_SYS_PCI_MSTR_MEMIO_BUS, CPU_PCI_MEMIO_START, 4145 CONFIG_SYS_PCI_MSTR_MEMIO_SIZE, CONFIG_SYS_POCMR1_MASK_ATTRIB, CONFIG_SYS_PCI_MSTR_IO_LOCAL, 4146 CONFIG_SYS_PCI_MSTR_IO_BUS, CONFIG_SYS_CPU_PCI_IO_START, CONFIG_SYS_PCI_MSTR_IO_SIZE, 4147 CONFIG_SYS_POCMR2_MASK_ATTRIB: (MPC826x only) 4148 Overrides the default PCI memory map in arch/powerpc/cpu/mpc8260/pci.c if set. 4149 4150- CONFIG_PCI_DISABLE_PCIE: 4151 Disable PCI-Express on systems where it is supported but not 4152 required. 4153 4154- CONFIG_PCI_ENUM_ONLY 4155 Only scan through and get the devices on the buses. 4156 Don't do any setup work, presumably because someone or 4157 something has already done it, and we don't need to do it 4158 a second time. Useful for platforms that are pre-booted 4159 by coreboot or similar. 4160 4161- CONFIG_PCI_INDIRECT_BRIDGE: 4162 Enable support for indirect PCI bridges. 4163 4164- CONFIG_SYS_SRIO: 4165 Chip has SRIO or not 4166 4167- CONFIG_SRIO1: 4168 Board has SRIO 1 port available 4169 4170- CONFIG_SRIO2: 4171 Board has SRIO 2 port available 4172 4173- CONFIG_SRIO_PCIE_BOOT_MASTER 4174 Board can support master function for Boot from SRIO and PCIE 4175 4176- CONFIG_SYS_SRIOn_MEM_VIRT: 4177 Virtual Address of SRIO port 'n' memory region 4178 4179- CONFIG_SYS_SRIOn_MEM_PHYS: 4180 Physical Address of SRIO port 'n' memory region 4181 4182- CONFIG_SYS_SRIOn_MEM_SIZE: 4183 Size of SRIO port 'n' memory region 4184 4185- CONFIG_SYS_NAND_BUSWIDTH_16BIT 4186 Defined to tell the NAND controller that the NAND chip is using 4187 a 16 bit bus. 4188 Not all NAND drivers use this symbol. 4189 Example of drivers that use it: 4190 - drivers/mtd/nand/ndfc.c 4191 - drivers/mtd/nand/mxc_nand.c 4192 4193- CONFIG_SYS_NDFC_EBC0_CFG 4194 Sets the EBC0_CFG register for the NDFC. If not defined 4195 a default value will be used. 4196 4197- CONFIG_SPD_EEPROM 4198 Get DDR timing information from an I2C EEPROM. Common 4199 with pluggable memory modules such as SODIMMs 4200 4201 SPD_EEPROM_ADDRESS 4202 I2C address of the SPD EEPROM 4203 4204- CONFIG_SYS_SPD_BUS_NUM 4205 If SPD EEPROM is on an I2C bus other than the first 4206 one, specify here. Note that the value must resolve 4207 to something your driver can deal with. 4208 4209- CONFIG_SYS_DDR_RAW_TIMING 4210 Get DDR timing information from other than SPD. Common with 4211 soldered DDR chips onboard without SPD. DDR raw timing 4212 parameters are extracted from datasheet and hard-coded into 4213 header files or board specific files. 4214 4215- CONFIG_FSL_DDR_INTERACTIVE 4216 Enable interactive DDR debugging. See doc/README.fsl-ddr. 4217 4218- CONFIG_FSL_DDR_SYNC_REFRESH 4219 Enable sync of refresh for multiple controllers. 4220 4221- CONFIG_FSL_DDR_BIST 4222 Enable built-in memory test for Freescale DDR controllers. 4223 4224- CONFIG_SYS_83XX_DDR_USES_CS0 4225 Only for 83xx systems. If specified, then DDR should 4226 be configured using CS0 and CS1 instead of CS2 and CS3. 4227 4228- CONFIG_ETHER_ON_FEC[12] 4229 Define to enable FEC[12] on a 8xx series processor. 4230 4231- CONFIG_FEC[12]_PHY 4232 Define to the hardcoded PHY address which corresponds 4233 to the given FEC; i. e. 4234 #define CONFIG_FEC1_PHY 4 4235 means that the PHY with address 4 is connected to FEC1 4236 4237 When set to -1, means to probe for first available. 4238 4239- CONFIG_FEC[12]_PHY_NORXERR 4240 The PHY does not have a RXERR line (RMII only). 4241 (so program the FEC to ignore it). 4242 4243- CONFIG_RMII 4244 Enable RMII mode for all FECs. 4245 Note that this is a global option, we can't 4246 have one FEC in standard MII mode and another in RMII mode. 4247 4248- CONFIG_CRC32_VERIFY 4249 Add a verify option to the crc32 command. 4250 The syntax is: 4251 4252 => crc32 -v <address> <count> <crc32> 4253 4254 Where address/count indicate a memory area 4255 and crc32 is the correct crc32 which the 4256 area should have. 4257 4258- CONFIG_LOOPW 4259 Add the "loopw" memory command. This only takes effect if 4260 the memory commands are activated globally (CONFIG_CMD_MEM). 4261 4262- CONFIG_MX_CYCLIC 4263 Add the "mdc" and "mwc" memory commands. These are cyclic 4264 "md/mw" commands. 4265 Examples: 4266 4267 => mdc.b 10 4 500 4268 This command will print 4 bytes (10,11,12,13) each 500 ms. 4269 4270 => mwc.l 100 12345678 10 4271 This command will write 12345678 to address 100 all 10 ms. 4272 4273 This only takes effect if the memory commands are activated 4274 globally (CONFIG_CMD_MEM). 4275 4276- CONFIG_SKIP_LOWLEVEL_INIT 4277 [ARM, NDS32, MIPS only] If this variable is defined, then certain 4278 low level initializations (like setting up the memory 4279 controller) are omitted and/or U-Boot does not 4280 relocate itself into RAM. 4281 4282 Normally this variable MUST NOT be defined. The only 4283 exception is when U-Boot is loaded (to RAM) by some 4284 other boot loader or by a debugger which performs 4285 these initializations itself. 4286 4287- CONFIG_SKIP_LOWLEVEL_INIT_ONLY 4288 [ARM926EJ-S only] This allows just the call to lowlevel_init() 4289 to be skipped. The normal CP15 init (such as enabling the 4290 instruction cache) is still performed. 4291 4292- CONFIG_SPL_BUILD 4293 Modifies the behaviour of start.S when compiling a loader 4294 that is executed before the actual U-Boot. E.g. when 4295 compiling a NAND SPL. 4296 4297- CONFIG_TPL_BUILD 4298 Modifies the behaviour of start.S when compiling a loader 4299 that is executed after the SPL and before the actual U-Boot. 4300 It is loaded by the SPL. 4301 4302- CONFIG_SYS_MPC85XX_NO_RESETVEC 4303 Only for 85xx systems. If this variable is specified, the section 4304 .resetvec is not kept and the section .bootpg is placed in the 4305 previous 4k of the .text section. 4306 4307- CONFIG_ARCH_MAP_SYSMEM 4308 Generally U-Boot (and in particular the md command) uses 4309 effective address. It is therefore not necessary to regard 4310 U-Boot address as virtual addresses that need to be translated 4311 to physical addresses. However, sandbox requires this, since 4312 it maintains its own little RAM buffer which contains all 4313 addressable memory. This option causes some memory accesses 4314 to be mapped through map_sysmem() / unmap_sysmem(). 4315 4316- CONFIG_X86_RESET_VECTOR 4317 If defined, the x86 reset vector code is included. This is not 4318 needed when U-Boot is running from Coreboot. 4319 4320- CONFIG_SPL_AM33XX_ENABLE_RTC32K_OSC: 4321 Enables the RTC32K OSC on AM33xx based plattforms 4322 4323- CONFIG_SYS_NAND_NO_SUBPAGE_WRITE 4324 Option to disable subpage write in NAND driver 4325 driver that uses this: 4326 drivers/mtd/nand/davinci_nand.c 4327 4328Freescale QE/FMAN Firmware Support: 4329----------------------------------- 4330 4331The Freescale QUICCEngine (QE) and Frame Manager (FMAN) both support the 4332loading of "firmware", which is encoded in the QE firmware binary format. 4333This firmware often needs to be loaded during U-Boot booting, so macros 4334are used to identify the storage device (NOR flash, SPI, etc) and the address 4335within that device. 4336 4337- CONFIG_SYS_FMAN_FW_ADDR 4338 The address in the storage device where the FMAN microcode is located. The 4339 meaning of this address depends on which CONFIG_SYS_QE_FW_IN_xxx macro 4340 is also specified. 4341 4342- CONFIG_SYS_QE_FW_ADDR 4343 The address in the storage device where the QE microcode is located. The 4344 meaning of this address depends on which CONFIG_SYS_QE_FW_IN_xxx macro 4345 is also specified. 4346 4347- CONFIG_SYS_QE_FMAN_FW_LENGTH 4348 The maximum possible size of the firmware. The firmware binary format 4349 has a field that specifies the actual size of the firmware, but it 4350 might not be possible to read any part of the firmware unless some 4351 local storage is allocated to hold the entire firmware first. 4352 4353- CONFIG_SYS_QE_FMAN_FW_IN_NOR 4354 Specifies that QE/FMAN firmware is located in NOR flash, mapped as 4355 normal addressable memory via the LBC. CONFIG_SYS_FMAN_FW_ADDR is the 4356 virtual address in NOR flash. 4357 4358- CONFIG_SYS_QE_FMAN_FW_IN_NAND 4359 Specifies that QE/FMAN firmware is located in NAND flash. 4360 CONFIG_SYS_FMAN_FW_ADDR is the offset within NAND flash. 4361 4362- CONFIG_SYS_QE_FMAN_FW_IN_MMC 4363 Specifies that QE/FMAN firmware is located on the primary SD/MMC 4364 device. CONFIG_SYS_FMAN_FW_ADDR is the byte offset on that device. 4365 4366- CONFIG_SYS_QE_FMAN_FW_IN_REMOTE 4367 Specifies that QE/FMAN firmware is located in the remote (master) 4368 memory space. CONFIG_SYS_FMAN_FW_ADDR is a virtual address which 4369 can be mapped from slave TLB->slave LAW->slave SRIO or PCIE outbound 4370 window->master inbound window->master LAW->the ucode address in 4371 master's memory space. 4372 4373Freescale Layerscape Management Complex Firmware Support: 4374--------------------------------------------------------- 4375The Freescale Layerscape Management Complex (MC) supports the loading of 4376"firmware". 4377This firmware often needs to be loaded during U-Boot booting, so macros 4378are used to identify the storage device (NOR flash, SPI, etc) and the address 4379within that device. 4380 4381- CONFIG_FSL_MC_ENET 4382 Enable the MC driver for Layerscape SoCs. 4383 4384Freescale Layerscape Debug Server Support: 4385------------------------------------------- 4386The Freescale Layerscape Debug Server Support supports the loading of 4387"Debug Server firmware" and triggering SP boot-rom. 4388This firmware often needs to be loaded during U-Boot booting. 4389 4390- CONFIG_SYS_MC_RSV_MEM_ALIGN 4391 Define alignment of reserved memory MC requires 4392 4393Reproducible builds 4394------------------- 4395 4396In order to achieve reproducible builds, timestamps used in the U-Boot build 4397process have to be set to a fixed value. 4398 4399This is done using the SOURCE_DATE_EPOCH environment variable. 4400SOURCE_DATE_EPOCH is to be set on the build host's shell, not as a configuration 4401option for U-Boot or an environment variable in U-Boot. 4402 4403SOURCE_DATE_EPOCH should be set to a number of seconds since the epoch, in UTC. 4404 4405Building the Software: 4406====================== 4407 4408Building U-Boot has been tested in several native build environments 4409and in many different cross environments. Of course we cannot support 4410all possibly existing versions of cross development tools in all 4411(potentially obsolete) versions. In case of tool chain problems we 4412recommend to use the ELDK (see http://www.denx.de/wiki/DULG/ELDK) 4413which is extensively used to build and test U-Boot. 4414 4415If you are not using a native environment, it is assumed that you 4416have GNU cross compiling tools available in your path. In this case, 4417you must set the environment variable CROSS_COMPILE in your shell. 4418Note that no changes to the Makefile or any other source files are 4419necessary. For example using the ELDK on a 4xx CPU, please enter: 4420 4421 $ CROSS_COMPILE=ppc_4xx- 4422 $ export CROSS_COMPILE 4423 4424Note: If you wish to generate Windows versions of the utilities in 4425 the tools directory you can use the MinGW toolchain 4426 (http://www.mingw.org). Set your HOST tools to the MinGW 4427 toolchain and execute 'make tools'. For example: 4428 4429 $ make HOSTCC=i586-mingw32msvc-gcc HOSTSTRIP=i586-mingw32msvc-strip tools 4430 4431 Binaries such as tools/mkimage.exe will be created which can 4432 be executed on computers running Windows. 4433 4434U-Boot is intended to be simple to build. After installing the 4435sources you must configure U-Boot for one specific board type. This 4436is done by typing: 4437 4438 make NAME_defconfig 4439 4440where "NAME_defconfig" is the name of one of the existing configu- 4441rations; see boards.cfg for supported names. 4442 4443Note: for some board special configuration names may exist; check if 4444 additional information is available from the board vendor; for 4445 instance, the TQM823L systems are available without (standard) 4446 or with LCD support. You can select such additional "features" 4447 when choosing the configuration, i. e. 4448 4449 make TQM823L_defconfig 4450 - will configure for a plain TQM823L, i. e. no LCD support 4451 4452 make TQM823L_LCD_defconfig 4453 - will configure for a TQM823L with U-Boot console on LCD 4454 4455 etc. 4456 4457 4458Finally, type "make all", and you should get some working U-Boot 4459images ready for download to / installation on your system: 4460 4461- "u-boot.bin" is a raw binary image 4462- "u-boot" is an image in ELF binary format 4463- "u-boot.srec" is in Motorola S-Record format 4464 4465By default the build is performed locally and the objects are saved 4466in the source directory. One of the two methods can be used to change 4467this behavior and build U-Boot to some external directory: 4468 44691. Add O= to the make command line invocations: 4470 4471 make O=/tmp/build distclean 4472 make O=/tmp/build NAME_defconfig 4473 make O=/tmp/build all 4474 44752. Set environment variable KBUILD_OUTPUT to point to the desired location: 4476 4477 export KBUILD_OUTPUT=/tmp/build 4478 make distclean 4479 make NAME_defconfig 4480 make all 4481 4482Note that the command line "O=" setting overrides the KBUILD_OUTPUT environment 4483variable. 4484 4485 4486Please be aware that the Makefiles assume you are using GNU make, so 4487for instance on NetBSD you might need to use "gmake" instead of 4488native "make". 4489 4490 4491If the system board that you have is not listed, then you will need 4492to port U-Boot to your hardware platform. To do this, follow these 4493steps: 4494 44951. Create a new directory to hold your board specific code. Add any 4496 files you need. In your board directory, you will need at least 4497 the "Makefile" and a "<board>.c". 44982. Create a new configuration file "include/configs/<board>.h" for 4499 your board. 45003. If you're porting U-Boot to a new CPU, then also create a new 4501 directory to hold your CPU specific code. Add any files you need. 45024. Run "make <board>_defconfig" with your new name. 45035. Type "make", and you should get a working "u-boot.srec" file 4504 to be installed on your target system. 45056. Debug and solve any problems that might arise. 4506 [Of course, this last step is much harder than it sounds.] 4507 4508 4509Testing of U-Boot Modifications, Ports to New Hardware, etc.: 4510============================================================== 4511 4512If you have modified U-Boot sources (for instance added a new board 4513or support for new devices, a new CPU, etc.) you are expected to 4514provide feedback to the other developers. The feedback normally takes 4515the form of a "patch", i. e. a context diff against a certain (latest 4516official or latest in the git repository) version of U-Boot sources. 4517 4518But before you submit such a patch, please verify that your modifi- 4519cation did not break existing code. At least make sure that *ALL* of 4520the supported boards compile WITHOUT ANY compiler warnings. To do so, 4521just run the buildman script (tools/buildman/buildman), which will 4522configure and build U-Boot for ALL supported system. Be warned, this 4523will take a while. Please see the buildman README, or run 'buildman -H' 4524for documentation. 4525 4526 4527See also "U-Boot Porting Guide" below. 4528 4529 4530Monitor Commands - Overview: 4531============================ 4532 4533go - start application at address 'addr' 4534run - run commands in an environment variable 4535bootm - boot application image from memory 4536bootp - boot image via network using BootP/TFTP protocol 4537bootz - boot zImage from memory 4538tftpboot- boot image via network using TFTP protocol 4539 and env variables "ipaddr" and "serverip" 4540 (and eventually "gatewayip") 4541tftpput - upload a file via network using TFTP protocol 4542rarpboot- boot image via network using RARP/TFTP protocol 4543diskboot- boot from IDE devicebootd - boot default, i.e., run 'bootcmd' 4544loads - load S-Record file over serial line 4545loadb - load binary file over serial line (kermit mode) 4546md - memory display 4547mm - memory modify (auto-incrementing) 4548nm - memory modify (constant address) 4549mw - memory write (fill) 4550cp - memory copy 4551cmp - memory compare 4552crc32 - checksum calculation 4553i2c - I2C sub-system 4554sspi - SPI utility commands 4555base - print or set address offset 4556printenv- print environment variables 4557setenv - set environment variables 4558saveenv - save environment variables to persistent storage 4559protect - enable or disable FLASH write protection 4560erase - erase FLASH memory 4561flinfo - print FLASH memory information 4562nand - NAND memory operations (see doc/README.nand) 4563bdinfo - print Board Info structure 4564iminfo - print header information for application image 4565coninfo - print console devices and informations 4566ide - IDE sub-system 4567loop - infinite loop on address range 4568loopw - infinite write loop on address range 4569mtest - simple RAM test 4570icache - enable or disable instruction cache 4571dcache - enable or disable data cache 4572reset - Perform RESET of the CPU 4573echo - echo args to console 4574version - print monitor version 4575help - print online help 4576? - alias for 'help' 4577 4578 4579Monitor Commands - Detailed Description: 4580======================================== 4581 4582TODO. 4583 4584For now: just type "help <command>". 4585 4586 4587Environment Variables: 4588====================== 4589 4590U-Boot supports user configuration using Environment Variables which 4591can be made persistent by saving to Flash memory. 4592 4593Environment Variables are set using "setenv", printed using 4594"printenv", and saved to Flash using "saveenv". Using "setenv" 4595without a value can be used to delete a variable from the 4596environment. As long as you don't save the environment you are 4597working with an in-memory copy. In case the Flash area containing the 4598environment is erased by accident, a default environment is provided. 4599 4600Some configuration options can be set using Environment Variables. 4601 4602List of environment variables (most likely not complete): 4603 4604 baudrate - see CONFIG_BAUDRATE 4605 4606 bootdelay - see CONFIG_BOOTDELAY 4607 4608 bootcmd - see CONFIG_BOOTCOMMAND 4609 4610 bootargs - Boot arguments when booting an RTOS image 4611 4612 bootfile - Name of the image to load with TFTP 4613 4614 bootm_low - Memory range available for image processing in the bootm 4615 command can be restricted. This variable is given as 4616 a hexadecimal number and defines lowest address allowed 4617 for use by the bootm command. See also "bootm_size" 4618 environment variable. Address defined by "bootm_low" is 4619 also the base of the initial memory mapping for the Linux 4620 kernel -- see the description of CONFIG_SYS_BOOTMAPSZ and 4621 bootm_mapsize. 4622 4623 bootm_mapsize - Size of the initial memory mapping for the Linux kernel. 4624 This variable is given as a hexadecimal number and it 4625 defines the size of the memory region starting at base 4626 address bootm_low that is accessible by the Linux kernel 4627 during early boot. If unset, CONFIG_SYS_BOOTMAPSZ is used 4628 as the default value if it is defined, and bootm_size is 4629 used otherwise. 4630 4631 bootm_size - Memory range available for image processing in the bootm 4632 command can be restricted. This variable is given as 4633 a hexadecimal number and defines the size of the region 4634 allowed for use by the bootm command. See also "bootm_low" 4635 environment variable. 4636 4637 updatefile - Location of the software update file on a TFTP server, used 4638 by the automatic software update feature. Please refer to 4639 documentation in doc/README.update for more details. 4640 4641 autoload - if set to "no" (any string beginning with 'n'), 4642 "bootp" will just load perform a lookup of the 4643 configuration from the BOOTP server, but not try to 4644 load any image using TFTP 4645 4646 autostart - if set to "yes", an image loaded using the "bootp", 4647 "rarpboot", "tftpboot" or "diskboot" commands will 4648 be automatically started (by internally calling 4649 "bootm") 4650 4651 If set to "no", a standalone image passed to the 4652 "bootm" command will be copied to the load address 4653 (and eventually uncompressed), but NOT be started. 4654 This can be used to load and uncompress arbitrary 4655 data. 4656 4657 fdt_high - if set this restricts the maximum address that the 4658 flattened device tree will be copied into upon boot. 4659 For example, if you have a system with 1 GB memory 4660 at physical address 0x10000000, while Linux kernel 4661 only recognizes the first 704 MB as low memory, you 4662 may need to set fdt_high as 0x3C000000 to have the 4663 device tree blob be copied to the maximum address 4664 of the 704 MB low memory, so that Linux kernel can 4665 access it during the boot procedure. 4666 4667 If this is set to the special value 0xFFFFFFFF then 4668 the fdt will not be copied at all on boot. For this 4669 to work it must reside in writable memory, have 4670 sufficient padding on the end of it for u-boot to 4671 add the information it needs into it, and the memory 4672 must be accessible by the kernel. 4673 4674 fdtcontroladdr- if set this is the address of the control flattened 4675 device tree used by U-Boot when CONFIG_OF_CONTROL is 4676 defined. 4677 4678 i2cfast - (PPC405GP|PPC405EP only) 4679 if set to 'y' configures Linux I2C driver for fast 4680 mode (400kHZ). This environment variable is used in 4681 initialization code. So, for changes to be effective 4682 it must be saved and board must be reset. 4683 4684 initrd_high - restrict positioning of initrd images: 4685 If this variable is not set, initrd images will be 4686 copied to the highest possible address in RAM; this 4687 is usually what you want since it allows for 4688 maximum initrd size. If for some reason you want to 4689 make sure that the initrd image is loaded below the 4690 CONFIG_SYS_BOOTMAPSZ limit, you can set this environment 4691 variable to a value of "no" or "off" or "0". 4692 Alternatively, you can set it to a maximum upper 4693 address to use (U-Boot will still check that it 4694 does not overwrite the U-Boot stack and data). 4695 4696 For instance, when you have a system with 16 MB 4697 RAM, and want to reserve 4 MB from use by Linux, 4698 you can do this by adding "mem=12M" to the value of 4699 the "bootargs" variable. However, now you must make 4700 sure that the initrd image is placed in the first 4701 12 MB as well - this can be done with 4702 4703 setenv initrd_high 00c00000 4704 4705 If you set initrd_high to 0xFFFFFFFF, this is an 4706 indication to U-Boot that all addresses are legal 4707 for the Linux kernel, including addresses in flash 4708 memory. In this case U-Boot will NOT COPY the 4709 ramdisk at all. This may be useful to reduce the 4710 boot time on your system, but requires that this 4711 feature is supported by your Linux kernel. 4712 4713 ipaddr - IP address; needed for tftpboot command 4714 4715 loadaddr - Default load address for commands like "bootp", 4716 "rarpboot", "tftpboot", "loadb" or "diskboot" 4717 4718 loads_echo - see CONFIG_LOADS_ECHO 4719 4720 serverip - TFTP server IP address; needed for tftpboot command 4721 4722 bootretry - see CONFIG_BOOT_RETRY_TIME 4723 4724 bootdelaykey - see CONFIG_AUTOBOOT_DELAY_STR 4725 4726 bootstopkey - see CONFIG_AUTOBOOT_STOP_STR 4727 4728 ethprime - controls which interface is used first. 4729 4730 ethact - controls which interface is currently active. 4731 For example you can do the following 4732 4733 => setenv ethact FEC 4734 => ping 192.168.0.1 # traffic sent on FEC 4735 => setenv ethact SCC 4736 => ping 10.0.0.1 # traffic sent on SCC 4737 4738 ethrotate - When set to "no" U-Boot does not go through all 4739 available network interfaces. 4740 It just stays at the currently selected interface. 4741 4742 netretry - When set to "no" each network operation will 4743 either succeed or fail without retrying. 4744 When set to "once" the network operation will 4745 fail when all the available network interfaces 4746 are tried once without success. 4747 Useful on scripts which control the retry operation 4748 themselves. 4749 4750 npe_ucode - set load address for the NPE microcode 4751 4752 silent_linux - If set then Linux will be told to boot silently, by 4753 changing the console to be empty. If "yes" it will be 4754 made silent. If "no" it will not be made silent. If 4755 unset, then it will be made silent if the U-Boot console 4756 is silent. 4757 4758 tftpsrcp - If this is set, the value is used for TFTP's 4759 UDP source port. 4760 4761 tftpdstp - If this is set, the value is used for TFTP's UDP 4762 destination port instead of the Well Know Port 69. 4763 4764 tftpblocksize - Block size to use for TFTP transfers; if not set, 4765 we use the TFTP server's default block size 4766 4767 tftptimeout - Retransmission timeout for TFTP packets (in milli- 4768 seconds, minimum value is 1000 = 1 second). Defines 4769 when a packet is considered to be lost so it has to 4770 be retransmitted. The default is 5000 = 5 seconds. 4771 Lowering this value may make downloads succeed 4772 faster in networks with high packet loss rates or 4773 with unreliable TFTP servers. 4774 4775 tftptimeoutcountmax - maximum count of TFTP timeouts (no 4776 unit, minimum value = 0). Defines how many timeouts 4777 can happen during a single file transfer before that 4778 transfer is aborted. The default is 10, and 0 means 4779 'no timeouts allowed'. Increasing this value may help 4780 downloads succeed with high packet loss rates, or with 4781 unreliable TFTP servers or client hardware. 4782 4783 vlan - When set to a value < 4095 the traffic over 4784 Ethernet is encapsulated/received over 802.1q 4785 VLAN tagged frames. 4786 4787 bootpretryperiod - Period during which BOOTP/DHCP sends retries. 4788 Unsigned value, in milliseconds. If not set, the period will 4789 be either the default (28000), or a value based on 4790 CONFIG_NET_RETRY_COUNT, if defined. This value has 4791 precedence over the valu based on CONFIG_NET_RETRY_COUNT. 4792 4793The following image location variables contain the location of images 4794used in booting. The "Image" column gives the role of the image and is 4795not an environment variable name. The other columns are environment 4796variable names. "File Name" gives the name of the file on a TFTP 4797server, "RAM Address" gives the location in RAM the image will be 4798loaded to, and "Flash Location" gives the image's address in NOR 4799flash or offset in NAND flash. 4800 4801*Note* - these variables don't have to be defined for all boards, some 4802boards currently use other variables for these purposes, and some 4803boards use these variables for other purposes. 4804 4805Image File Name RAM Address Flash Location 4806----- --------- ----------- -------------- 4807u-boot u-boot u-boot_addr_r u-boot_addr 4808Linux kernel bootfile kernel_addr_r kernel_addr 4809device tree blob fdtfile fdt_addr_r fdt_addr 4810ramdisk ramdiskfile ramdisk_addr_r ramdisk_addr 4811 4812The following environment variables may be used and automatically 4813updated by the network boot commands ("bootp" and "rarpboot"), 4814depending the information provided by your boot server: 4815 4816 bootfile - see above 4817 dnsip - IP address of your Domain Name Server 4818 dnsip2 - IP address of your secondary Domain Name Server 4819 gatewayip - IP address of the Gateway (Router) to use 4820 hostname - Target hostname 4821 ipaddr - see above 4822 netmask - Subnet Mask 4823 rootpath - Pathname of the root filesystem on the NFS server 4824 serverip - see above 4825 4826 4827There are two special Environment Variables: 4828 4829 serial# - contains hardware identification information such 4830 as type string and/or serial number 4831 ethaddr - Ethernet address 4832 4833These variables can be set only once (usually during manufacturing of 4834the board). U-Boot refuses to delete or overwrite these variables 4835once they have been set once. 4836 4837 4838Further special Environment Variables: 4839 4840 ver - Contains the U-Boot version string as printed 4841 with the "version" command. This variable is 4842 readonly (see CONFIG_VERSION_VARIABLE). 4843 4844 4845Please note that changes to some configuration parameters may take 4846only effect after the next boot (yes, that's just like Windoze :-). 4847 4848 4849Callback functions for environment variables: 4850--------------------------------------------- 4851 4852For some environment variables, the behavior of u-boot needs to change 4853when their values are changed. This functionality allows functions to 4854be associated with arbitrary variables. On creation, overwrite, or 4855deletion, the callback will provide the opportunity for some side 4856effect to happen or for the change to be rejected. 4857 4858The callbacks are named and associated with a function using the 4859U_BOOT_ENV_CALLBACK macro in your board or driver code. 4860 4861These callbacks are associated with variables in one of two ways. The 4862static list can be added to by defining CONFIG_ENV_CALLBACK_LIST_STATIC 4863in the board configuration to a string that defines a list of 4864associations. The list must be in the following format: 4865 4866 entry = variable_name[:callback_name] 4867 list = entry[,list] 4868 4869If the callback name is not specified, then the callback is deleted. 4870Spaces are also allowed anywhere in the list. 4871 4872Callbacks can also be associated by defining the ".callbacks" variable 4873with the same list format above. Any association in ".callbacks" will 4874override any association in the static list. You can define 4875CONFIG_ENV_CALLBACK_LIST_DEFAULT to a list (string) to define the 4876".callbacks" environment variable in the default or embedded environment. 4877 4878If CONFIG_REGEX is defined, the variable_name above is evaluated as a 4879regular expression. This allows multiple variables to be connected to 4880the same callback without explicitly listing them all out. 4881 4882 4883Command Line Parsing: 4884===================== 4885 4886There are two different command line parsers available with U-Boot: 4887the old "simple" one, and the much more powerful "hush" shell: 4888 4889Old, simple command line parser: 4890-------------------------------- 4891 4892- supports environment variables (through setenv / saveenv commands) 4893- several commands on one line, separated by ';' 4894- variable substitution using "... ${name} ..." syntax 4895- special characters ('$', ';') can be escaped by prefixing with '\', 4896 for example: 4897 setenv bootcmd bootm \${address} 4898- You can also escape text by enclosing in single apostrophes, for example: 4899 setenv addip 'setenv bootargs $bootargs ip=$ipaddr:$serverip:$gatewayip:$netmask:$hostname::off' 4900 4901Hush shell: 4902----------- 4903 4904- similar to Bourne shell, with control structures like 4905 if...then...else...fi, for...do...done; while...do...done, 4906 until...do...done, ... 4907- supports environment ("global") variables (through setenv / saveenv 4908 commands) and local shell variables (through standard shell syntax 4909 "name=value"); only environment variables can be used with "run" 4910 command 4911 4912General rules: 4913-------------- 4914 4915(1) If a command line (or an environment variable executed by a "run" 4916 command) contains several commands separated by semicolon, and 4917 one of these commands fails, then the remaining commands will be 4918 executed anyway. 4919 4920(2) If you execute several variables with one call to run (i. e. 4921 calling run with a list of variables as arguments), any failing 4922 command will cause "run" to terminate, i. e. the remaining 4923 variables are not executed. 4924 4925Note for Redundant Ethernet Interfaces: 4926======================================= 4927 4928Some boards come with redundant Ethernet interfaces; U-Boot supports 4929such configurations and is capable of automatic selection of a 4930"working" interface when needed. MAC assignment works as follows: 4931 4932Network interfaces are numbered eth0, eth1, eth2, ... Corresponding 4933MAC addresses can be stored in the environment as "ethaddr" (=>eth0), 4934"eth1addr" (=>eth1), "eth2addr", ... 4935 4936If the network interface stores some valid MAC address (for instance 4937in SROM), this is used as default address if there is NO correspon- 4938ding setting in the environment; if the corresponding environment 4939variable is set, this overrides the settings in the card; that means: 4940 4941o If the SROM has a valid MAC address, and there is no address in the 4942 environment, the SROM's address is used. 4943 4944o If there is no valid address in the SROM, and a definition in the 4945 environment exists, then the value from the environment variable is 4946 used. 4947 4948o If both the SROM and the environment contain a MAC address, and 4949 both addresses are the same, this MAC address is used. 4950 4951o If both the SROM and the environment contain a MAC address, and the 4952 addresses differ, the value from the environment is used and a 4953 warning is printed. 4954 4955o If neither SROM nor the environment contain a MAC address, an error 4956 is raised. If CONFIG_NET_RANDOM_ETHADDR is defined, then in this case 4957 a random, locally-assigned MAC is used. 4958 4959If Ethernet drivers implement the 'write_hwaddr' function, valid MAC addresses 4960will be programmed into hardware as part of the initialization process. This 4961may be skipped by setting the appropriate 'ethmacskip' environment variable. 4962The naming convention is as follows: 4963"ethmacskip" (=>eth0), "eth1macskip" (=>eth1) etc. 4964 4965Image Formats: 4966============== 4967 4968U-Boot is capable of booting (and performing other auxiliary operations on) 4969images in two formats: 4970 4971New uImage format (FIT) 4972----------------------- 4973 4974Flexible and powerful format based on Flattened Image Tree -- FIT (similar 4975to Flattened Device Tree). It allows the use of images with multiple 4976components (several kernels, ramdisks, etc.), with contents protected by 4977SHA1, MD5 or CRC32. More details are found in the doc/uImage.FIT directory. 4978 4979 4980Old uImage format 4981----------------- 4982 4983Old image format is based on binary files which can be basically anything, 4984preceded by a special header; see the definitions in include/image.h for 4985details; basically, the header defines the following image properties: 4986 4987* Target Operating System (Provisions for OpenBSD, NetBSD, FreeBSD, 4988 4.4BSD, Linux, SVR4, Esix, Solaris, Irix, SCO, Dell, NCR, VxWorks, 4989 LynxOS, pSOS, QNX, RTEMS, INTEGRITY; 4990 Currently supported: Linux, NetBSD, VxWorks, QNX, RTEMS, LynxOS, 4991 INTEGRITY). 4992* Target CPU Architecture (Provisions for Alpha, ARM, AVR32, Intel x86, 4993 IA64, MIPS, NDS32, Nios II, PowerPC, IBM S390, SuperH, Sparc, Sparc 64 Bit; 4994 Currently supported: ARM, AVR32, Intel x86, MIPS, NDS32, Nios II, PowerPC). 4995* Compression Type (uncompressed, gzip, bzip2) 4996* Load Address 4997* Entry Point 4998* Image Name 4999* Image Timestamp 5000 5001The header is marked by a special Magic Number, and both the header 5002and the data portions of the image are secured against corruption by 5003CRC32 checksums. 5004 5005 5006Linux Support: 5007============== 5008 5009Although U-Boot should support any OS or standalone application 5010easily, the main focus has always been on Linux during the design of 5011U-Boot. 5012 5013U-Boot includes many features that so far have been part of some 5014special "boot loader" code within the Linux kernel. Also, any 5015"initrd" images to be used are no longer part of one big Linux image; 5016instead, kernel and "initrd" are separate images. This implementation 5017serves several purposes: 5018 5019- the same features can be used for other OS or standalone 5020 applications (for instance: using compressed images to reduce the 5021 Flash memory footprint) 5022 5023- it becomes much easier to port new Linux kernel versions because 5024 lots of low-level, hardware dependent stuff are done by U-Boot 5025 5026- the same Linux kernel image can now be used with different "initrd" 5027 images; of course this also means that different kernel images can 5028 be run with the same "initrd". This makes testing easier (you don't 5029 have to build a new "zImage.initrd" Linux image when you just 5030 change a file in your "initrd"). Also, a field-upgrade of the 5031 software is easier now. 5032 5033 5034Linux HOWTO: 5035============ 5036 5037Porting Linux to U-Boot based systems: 5038--------------------------------------- 5039 5040U-Boot cannot save you from doing all the necessary modifications to 5041configure the Linux device drivers for use with your target hardware 5042(no, we don't intend to provide a full virtual machine interface to 5043Linux :-). 5044 5045But now you can ignore ALL boot loader code (in arch/powerpc/mbxboot). 5046 5047Just make sure your machine specific header file (for instance 5048include/asm-ppc/tqm8xx.h) includes the same definition of the Board 5049Information structure as we define in include/asm-<arch>/u-boot.h, 5050and make sure that your definition of IMAP_ADDR uses the same value 5051as your U-Boot configuration in CONFIG_SYS_IMMR. 5052 5053Note that U-Boot now has a driver model, a unified model for drivers. 5054If you are adding a new driver, plumb it into driver model. If there 5055is no uclass available, you are encouraged to create one. See 5056doc/driver-model. 5057 5058 5059Configuring the Linux kernel: 5060----------------------------- 5061 5062No specific requirements for U-Boot. Make sure you have some root 5063device (initial ramdisk, NFS) for your target system. 5064 5065 5066Building a Linux Image: 5067----------------------- 5068 5069With U-Boot, "normal" build targets like "zImage" or "bzImage" are 5070not used. If you use recent kernel source, a new build target 5071"uImage" will exist which automatically builds an image usable by 5072U-Boot. Most older kernels also have support for a "pImage" target, 5073which was introduced for our predecessor project PPCBoot and uses a 5074100% compatible format. 5075 5076Example: 5077 5078 make TQM850L_defconfig 5079 make oldconfig 5080 make dep 5081 make uImage 5082 5083The "uImage" build target uses a special tool (in 'tools/mkimage') to 5084encapsulate a compressed Linux kernel image with header information, 5085CRC32 checksum etc. for use with U-Boot. This is what we are doing: 5086 5087* build a standard "vmlinux" kernel image (in ELF binary format): 5088 5089* convert the kernel into a raw binary image: 5090 5091 ${CROSS_COMPILE}-objcopy -O binary \ 5092 -R .note -R .comment \ 5093 -S vmlinux linux.bin 5094 5095* compress the binary image: 5096 5097 gzip -9 linux.bin 5098 5099* package compressed binary image for U-Boot: 5100 5101 mkimage -A ppc -O linux -T kernel -C gzip \ 5102 -a 0 -e 0 -n "Linux Kernel Image" \ 5103 -d linux.bin.gz uImage 5104 5105 5106The "mkimage" tool can also be used to create ramdisk images for use 5107with U-Boot, either separated from the Linux kernel image, or 5108combined into one file. "mkimage" encapsulates the images with a 64 5109byte header containing information about target architecture, 5110operating system, image type, compression method, entry points, time 5111stamp, CRC32 checksums, etc. 5112 5113"mkimage" can be called in two ways: to verify existing images and 5114print the header information, or to build new images. 5115 5116In the first form (with "-l" option) mkimage lists the information 5117contained in the header of an existing U-Boot image; this includes 5118checksum verification: 5119 5120 tools/mkimage -l image 5121 -l ==> list image header information 5122 5123The second form (with "-d" option) is used to build a U-Boot image 5124from a "data file" which is used as image payload: 5125 5126 tools/mkimage -A arch -O os -T type -C comp -a addr -e ep \ 5127 -n name -d data_file image 5128 -A ==> set architecture to 'arch' 5129 -O ==> set operating system to 'os' 5130 -T ==> set image type to 'type' 5131 -C ==> set compression type 'comp' 5132 -a ==> set load address to 'addr' (hex) 5133 -e ==> set entry point to 'ep' (hex) 5134 -n ==> set image name to 'name' 5135 -d ==> use image data from 'datafile' 5136 5137Right now, all Linux kernels for PowerPC systems use the same load 5138address (0x00000000), but the entry point address depends on the 5139kernel version: 5140 5141- 2.2.x kernels have the entry point at 0x0000000C, 5142- 2.3.x and later kernels have the entry point at 0x00000000. 5143 5144So a typical call to build a U-Boot image would read: 5145 5146 -> tools/mkimage -n '2.4.4 kernel for TQM850L' \ 5147 > -A ppc -O linux -T kernel -C gzip -a 0 -e 0 \ 5148 > -d /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/powerpc/coffboot/vmlinux.gz \ 5149 > examples/uImage.TQM850L 5150 Image Name: 2.4.4 kernel for TQM850L 5151 Created: Wed Jul 19 02:34:59 2000 5152 Image Type: PowerPC Linux Kernel Image (gzip compressed) 5153 Data Size: 335725 Bytes = 327.86 kB = 0.32 MB 5154 Load Address: 0x00000000 5155 Entry Point: 0x00000000 5156 5157To verify the contents of the image (or check for corruption): 5158 5159 -> tools/mkimage -l examples/uImage.TQM850L 5160 Image Name: 2.4.4 kernel for TQM850L 5161 Created: Wed Jul 19 02:34:59 2000 5162 Image Type: PowerPC Linux Kernel Image (gzip compressed) 5163 Data Size: 335725 Bytes = 327.86 kB = 0.32 MB 5164 Load Address: 0x00000000 5165 Entry Point: 0x00000000 5166 5167NOTE: for embedded systems where boot time is critical you can trade 5168speed for memory and install an UNCOMPRESSED image instead: this 5169needs more space in Flash, but boots much faster since it does not 5170need to be uncompressed: 5171 5172 -> gunzip /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/powerpc/coffboot/vmlinux.gz 5173 -> tools/mkimage -n '2.4.4 kernel for TQM850L' \ 5174 > -A ppc -O linux -T kernel -C none -a 0 -e 0 \ 5175 > -d /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/powerpc/coffboot/vmlinux \ 5176 > examples/uImage.TQM850L-uncompressed 5177 Image Name: 2.4.4 kernel for TQM850L 5178 Created: Wed Jul 19 02:34:59 2000 5179 Image Type: PowerPC Linux Kernel Image (uncompressed) 5180 Data Size: 792160 Bytes = 773.59 kB = 0.76 MB 5181 Load Address: 0x00000000 5182 Entry Point: 0x00000000 5183 5184 5185Similar you can build U-Boot images from a 'ramdisk.image.gz' file 5186when your kernel is intended to use an initial ramdisk: 5187 5188 -> tools/mkimage -n 'Simple Ramdisk Image' \ 5189 > -A ppc -O linux -T ramdisk -C gzip \ 5190 > -d /LinuxPPC/images/SIMPLE-ramdisk.image.gz examples/simple-initrd 5191 Image Name: Simple Ramdisk Image 5192 Created: Wed Jan 12 14:01:50 2000 5193 Image Type: PowerPC Linux RAMDisk Image (gzip compressed) 5194 Data Size: 566530 Bytes = 553.25 kB = 0.54 MB 5195 Load Address: 0x00000000 5196 Entry Point: 0x00000000 5197 5198The "dumpimage" is a tool to disassemble images built by mkimage. Its "-i" 5199option performs the converse operation of the mkimage's second form (the "-d" 5200option). Given an image built by mkimage, the dumpimage extracts a "data file" 5201from the image: 5202 5203 tools/dumpimage -i image -T type -p position data_file 5204 -i ==> extract from the 'image' a specific 'data_file' 5205 -T ==> set image type to 'type' 5206 -p ==> 'position' (starting at 0) of the 'data_file' inside the 'image' 5207 5208 5209Installing a Linux Image: 5210------------------------- 5211 5212To downloading a U-Boot image over the serial (console) interface, 5213you must convert the image to S-Record format: 5214 5215 objcopy -I binary -O srec examples/image examples/image.srec 5216 5217The 'objcopy' does not understand the information in the U-Boot 5218image header, so the resulting S-Record file will be relative to 5219address 0x00000000. To load it to a given address, you need to 5220specify the target address as 'offset' parameter with the 'loads' 5221command. 5222 5223Example: install the image to address 0x40100000 (which on the 5224TQM8xxL is in the first Flash bank): 5225 5226 => erase 40100000 401FFFFF 5227 5228 .......... done 5229 Erased 8 sectors 5230 5231 => loads 40100000 5232 ## Ready for S-Record download ... 5233 ~>examples/image.srec 5234 1 2 3 4 5 6 7 8 9 10 11 12 13 ... 5235 ... 5236 15989 15990 15991 15992 5237 [file transfer complete] 5238 [connected] 5239 ## Start Addr = 0x00000000 5240 5241 5242You can check the success of the download using the 'iminfo' command; 5243this includes a checksum verification so you can be sure no data 5244corruption happened: 5245 5246 => imi 40100000 5247 5248 ## Checking Image at 40100000 ... 5249 Image Name: 2.2.13 for initrd on TQM850L 5250 Image Type: PowerPC Linux Kernel Image (gzip compressed) 5251 Data Size: 335725 Bytes = 327 kB = 0 MB 5252 Load Address: 00000000 5253 Entry Point: 0000000c 5254 Verifying Checksum ... OK 5255 5256 5257Boot Linux: 5258----------- 5259 5260The "bootm" command is used to boot an application that is stored in 5261memory (RAM or Flash). In case of a Linux kernel image, the contents 5262of the "bootargs" environment variable is passed to the kernel as 5263parameters. You can check and modify this variable using the 5264"printenv" and "setenv" commands: 5265 5266 5267 => printenv bootargs 5268 bootargs=root=/dev/ram 5269 5270 => setenv bootargs root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2 5271 5272 => printenv bootargs 5273 bootargs=root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2 5274 5275 => bootm 40020000 5276 ## Booting Linux kernel at 40020000 ... 5277 Image Name: 2.2.13 for NFS on TQM850L 5278 Image Type: PowerPC Linux Kernel Image (gzip compressed) 5279 Data Size: 381681 Bytes = 372 kB = 0 MB 5280 Load Address: 00000000 5281 Entry Point: 0000000c 5282 Verifying Checksum ... OK 5283 Uncompressing Kernel Image ... OK 5284 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 5285 Boot arguments: root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2 5286 time_init: decrementer frequency = 187500000/60 5287 Calibrating delay loop... 49.77 BogoMIPS 5288 Memory: 15208k available (700k kernel code, 444k data, 32k init) [c0000000,c1000000] 5289 ... 5290 5291If you want to boot a Linux kernel with initial RAM disk, you pass 5292the memory addresses of both the kernel and the initrd image (PPBCOOT 5293format!) to the "bootm" command: 5294 5295 => imi 40100000 40200000 5296 5297 ## Checking Image at 40100000 ... 5298 Image Name: 2.2.13 for initrd on TQM850L 5299 Image Type: PowerPC Linux Kernel Image (gzip compressed) 5300 Data Size: 335725 Bytes = 327 kB = 0 MB 5301 Load Address: 00000000 5302 Entry Point: 0000000c 5303 Verifying Checksum ... OK 5304 5305 ## Checking Image at 40200000 ... 5306 Image Name: Simple Ramdisk Image 5307 Image Type: PowerPC Linux RAMDisk Image (gzip compressed) 5308 Data Size: 566530 Bytes = 553 kB = 0 MB 5309 Load Address: 00000000 5310 Entry Point: 00000000 5311 Verifying Checksum ... OK 5312 5313 => bootm 40100000 40200000 5314 ## Booting Linux kernel at 40100000 ... 5315 Image Name: 2.2.13 for initrd on TQM850L 5316 Image Type: PowerPC Linux Kernel Image (gzip compressed) 5317 Data Size: 335725 Bytes = 327 kB = 0 MB 5318 Load Address: 00000000 5319 Entry Point: 0000000c 5320 Verifying Checksum ... OK 5321 Uncompressing Kernel Image ... OK 5322 ## Loading RAMDisk Image at 40200000 ... 5323 Image Name: Simple Ramdisk Image 5324 Image Type: PowerPC Linux RAMDisk Image (gzip compressed) 5325 Data Size: 566530 Bytes = 553 kB = 0 MB 5326 Load Address: 00000000 5327 Entry Point: 00000000 5328 Verifying Checksum ... OK 5329 Loading Ramdisk ... OK 5330 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 5331 Boot arguments: root=/dev/ram 5332 time_init: decrementer frequency = 187500000/60 5333 Calibrating delay loop... 49.77 BogoMIPS 5334 ... 5335 RAMDISK: Compressed image found at block 0 5336 VFS: Mounted root (ext2 filesystem). 5337 5338 bash# 5339 5340Boot Linux and pass a flat device tree: 5341----------- 5342 5343First, U-Boot must be compiled with the appropriate defines. See the section 5344titled "Linux Kernel Interface" above for a more in depth explanation. The 5345following is an example of how to start a kernel and pass an updated 5346flat device tree: 5347 5348=> print oftaddr 5349oftaddr=0x300000 5350=> print oft 5351oft=oftrees/mpc8540ads.dtb 5352=> tftp $oftaddr $oft 5353Speed: 1000, full duplex 5354Using TSEC0 device 5355TFTP from server 192.168.1.1; our IP address is 192.168.1.101 5356Filename 'oftrees/mpc8540ads.dtb'. 5357Load address: 0x300000 5358Loading: # 5359done 5360Bytes transferred = 4106 (100a hex) 5361=> tftp $loadaddr $bootfile 5362Speed: 1000, full duplex 5363Using TSEC0 device 5364TFTP from server 192.168.1.1; our IP address is 192.168.1.2 5365Filename 'uImage'. 5366Load address: 0x200000 5367Loading:############ 5368done 5369Bytes transferred = 1029407 (fb51f hex) 5370=> print loadaddr 5371loadaddr=200000 5372=> print oftaddr 5373oftaddr=0x300000 5374=> bootm $loadaddr - $oftaddr 5375## Booting image at 00200000 ... 5376 Image Name: Linux-2.6.17-dirty 5377 Image Type: PowerPC Linux Kernel Image (gzip compressed) 5378 Data Size: 1029343 Bytes = 1005.2 kB 5379 Load Address: 00000000 5380 Entry Point: 00000000 5381 Verifying Checksum ... OK 5382 Uncompressing Kernel Image ... OK 5383Booting using flat device tree at 0x300000 5384Using MPC85xx ADS machine description 5385Memory CAM mapping: CAM0=256Mb, CAM1=256Mb, CAM2=0Mb residual: 0Mb 5386[snip] 5387 5388 5389More About U-Boot Image Types: 5390------------------------------ 5391 5392U-Boot supports the following image types: 5393 5394 "Standalone Programs" are directly runnable in the environment 5395 provided by U-Boot; it is expected that (if they behave 5396 well) you can continue to work in U-Boot after return from 5397 the Standalone Program. 5398 "OS Kernel Images" are usually images of some Embedded OS which 5399 will take over control completely. Usually these programs 5400 will install their own set of exception handlers, device 5401 drivers, set up the MMU, etc. - this means, that you cannot 5402 expect to re-enter U-Boot except by resetting the CPU. 5403 "RAMDisk Images" are more or less just data blocks, and their 5404 parameters (address, size) are passed to an OS kernel that is 5405 being started. 5406 "Multi-File Images" contain several images, typically an OS 5407 (Linux) kernel image and one or more data images like 5408 RAMDisks. This construct is useful for instance when you want 5409 to boot over the network using BOOTP etc., where the boot 5410 server provides just a single image file, but you want to get 5411 for instance an OS kernel and a RAMDisk image. 5412 5413 "Multi-File Images" start with a list of image sizes, each 5414 image size (in bytes) specified by an "uint32_t" in network 5415 byte order. This list is terminated by an "(uint32_t)0". 5416 Immediately after the terminating 0 follow the images, one by 5417 one, all aligned on "uint32_t" boundaries (size rounded up to 5418 a multiple of 4 bytes). 5419 5420 "Firmware Images" are binary images containing firmware (like 5421 U-Boot or FPGA images) which usually will be programmed to 5422 flash memory. 5423 5424 "Script files" are command sequences that will be executed by 5425 U-Boot's command interpreter; this feature is especially 5426 useful when you configure U-Boot to use a real shell (hush) 5427 as command interpreter. 5428 5429Booting the Linux zImage: 5430------------------------- 5431 5432On some platforms, it's possible to boot Linux zImage. This is done 5433using the "bootz" command. The syntax of "bootz" command is the same 5434as the syntax of "bootm" command. 5435 5436Note, defining the CONFIG_SUPPORT_RAW_INITRD allows user to supply 5437kernel with raw initrd images. The syntax is slightly different, the 5438address of the initrd must be augmented by it's size, in the following 5439format: "<initrd addres>:<initrd size>". 5440 5441 5442Standalone HOWTO: 5443================= 5444 5445One of the features of U-Boot is that you can dynamically load and 5446run "standalone" applications, which can use some resources of 5447U-Boot like console I/O functions or interrupt services. 5448 5449Two simple examples are included with the sources: 5450 5451"Hello World" Demo: 5452------------------- 5453 5454'examples/hello_world.c' contains a small "Hello World" Demo 5455application; it is automatically compiled when you build U-Boot. 5456It's configured to run at address 0x00040004, so you can play with it 5457like that: 5458 5459 => loads 5460 ## Ready for S-Record download ... 5461 ~>examples/hello_world.srec 5462 1 2 3 4 5 6 7 8 9 10 11 ... 5463 [file transfer complete] 5464 [connected] 5465 ## Start Addr = 0x00040004 5466 5467 => go 40004 Hello World! This is a test. 5468 ## Starting application at 0x00040004 ... 5469 Hello World 5470 argc = 7 5471 argv[0] = "40004" 5472 argv[1] = "Hello" 5473 argv[2] = "World!" 5474 argv[3] = "This" 5475 argv[4] = "is" 5476 argv[5] = "a" 5477 argv[6] = "test." 5478 argv[7] = "<NULL>" 5479 Hit any key to exit ... 5480 5481 ## Application terminated, rc = 0x0 5482 5483Another example, which demonstrates how to register a CPM interrupt 5484handler with the U-Boot code, can be found in 'examples/timer.c'. 5485Here, a CPM timer is set up to generate an interrupt every second. 5486The interrupt service routine is trivial, just printing a '.' 5487character, but this is just a demo program. The application can be 5488controlled by the following keys: 5489 5490 ? - print current values og the CPM Timer registers 5491 b - enable interrupts and start timer 5492 e - stop timer and disable interrupts 5493 q - quit application 5494 5495 => loads 5496 ## Ready for S-Record download ... 5497 ~>examples/timer.srec 5498 1 2 3 4 5 6 7 8 9 10 11 ... 5499 [file transfer complete] 5500 [connected] 5501 ## Start Addr = 0x00040004 5502 5503 => go 40004 5504 ## Starting application at 0x00040004 ... 5505 TIMERS=0xfff00980 5506 Using timer 1 5507 tgcr @ 0xfff00980, tmr @ 0xfff00990, trr @ 0xfff00994, tcr @ 0xfff00998, tcn @ 0xfff0099c, ter @ 0xfff009b0 5508 5509Hit 'b': 5510 [q, b, e, ?] Set interval 1000000 us 5511 Enabling timer 5512Hit '?': 5513 [q, b, e, ?] ........ 5514 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0xef6, ter=0x0 5515Hit '?': 5516 [q, b, e, ?] . 5517 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x2ad4, ter=0x0 5518Hit '?': 5519 [q, b, e, ?] . 5520 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x1efc, ter=0x0 5521Hit '?': 5522 [q, b, e, ?] . 5523 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x169d, ter=0x0 5524Hit 'e': 5525 [q, b, e, ?] ...Stopping timer 5526Hit 'q': 5527 [q, b, e, ?] ## Application terminated, rc = 0x0 5528 5529 5530Minicom warning: 5531================ 5532 5533Over time, many people have reported problems when trying to use the 5534"minicom" terminal emulation program for serial download. I (wd) 5535consider minicom to be broken, and recommend not to use it. Under 5536Unix, I recommend to use C-Kermit for general purpose use (and 5537especially for kermit binary protocol download ("loadb" command), and 5538use "cu" for S-Record download ("loads" command). See 5539http://www.denx.de/wiki/view/DULG/SystemSetup#Section_4.3. 5540for help with kermit. 5541 5542 5543Nevertheless, if you absolutely want to use it try adding this 5544configuration to your "File transfer protocols" section: 5545 5546 Name Program Name U/D FullScr IO-Red. Multi 5547 X kermit /usr/bin/kermit -i -l %l -s Y U Y N N 5548 Y kermit /usr/bin/kermit -i -l %l -r N D Y N N 5549 5550 5551NetBSD Notes: 5552============= 5553 5554Starting at version 0.9.2, U-Boot supports NetBSD both as host 5555(build U-Boot) and target system (boots NetBSD/mpc8xx). 5556 5557Building requires a cross environment; it is known to work on 5558NetBSD/i386 with the cross-powerpc-netbsd-1.3 package (you will also 5559need gmake since the Makefiles are not compatible with BSD make). 5560Note that the cross-powerpc package does not install include files; 5561attempting to build U-Boot will fail because <machine/ansi.h> is 5562missing. This file has to be installed and patched manually: 5563 5564 # cd /usr/pkg/cross/powerpc-netbsd/include 5565 # mkdir powerpc 5566 # ln -s powerpc machine 5567 # cp /usr/src/sys/arch/powerpc/include/ansi.h powerpc/ansi.h 5568 # ${EDIT} powerpc/ansi.h ## must remove __va_list, _BSD_VA_LIST 5569 5570Native builds *don't* work due to incompatibilities between native 5571and U-Boot include files. 5572 5573Booting assumes that (the first part of) the image booted is a 5574stage-2 loader which in turn loads and then invokes the kernel 5575proper. Loader sources will eventually appear in the NetBSD source 5576tree (probably in sys/arc/mpc8xx/stand/u-boot_stage2/); in the 5577meantime, see ftp://ftp.denx.de/pub/u-boot/ppcboot_stage2.tar.gz 5578 5579 5580Implementation Internals: 5581========================= 5582 5583The following is not intended to be a complete description of every 5584implementation detail. However, it should help to understand the 5585inner workings of U-Boot and make it easier to port it to custom 5586hardware. 5587 5588 5589Initial Stack, Global Data: 5590--------------------------- 5591 5592The implementation of U-Boot is complicated by the fact that U-Boot 5593starts running out of ROM (flash memory), usually without access to 5594system RAM (because the memory controller is not initialized yet). 5595This means that we don't have writable Data or BSS segments, and BSS 5596is not initialized as zero. To be able to get a C environment working 5597at all, we have to allocate at least a minimal stack. Implementation 5598options for this are defined and restricted by the CPU used: Some CPU 5599models provide on-chip memory (like the IMMR area on MPC8xx and 5600MPC826x processors), on others (parts of) the data cache can be 5601locked as (mis-) used as memory, etc. 5602 5603 Chris Hallinan posted a good summary of these issues to the 5604 U-Boot mailing list: 5605 5606 Subject: RE: [U-Boot-Users] RE: More On Memory Bank x (nothingness)? 5607 From: "Chris Hallinan" <clh@net1plus.com> 5608 Date: Mon, 10 Feb 2003 16:43:46 -0500 (22:43 MET) 5609 ... 5610 5611 Correct me if I'm wrong, folks, but the way I understand it 5612 is this: Using DCACHE as initial RAM for Stack, etc, does not 5613 require any physical RAM backing up the cache. The cleverness 5614 is that the cache is being used as a temporary supply of 5615 necessary storage before the SDRAM controller is setup. It's 5616 beyond the scope of this list to explain the details, but you 5617 can see how this works by studying the cache architecture and 5618 operation in the architecture and processor-specific manuals. 5619 5620 OCM is On Chip Memory, which I believe the 405GP has 4K. It 5621 is another option for the system designer to use as an 5622 initial stack/RAM area prior to SDRAM being available. Either 5623 option should work for you. Using CS 4 should be fine if your 5624 board designers haven't used it for something that would 5625 cause you grief during the initial boot! It is frequently not 5626 used. 5627 5628 CONFIG_SYS_INIT_RAM_ADDR should be somewhere that won't interfere 5629 with your processor/board/system design. The default value 5630 you will find in any recent u-boot distribution in 5631 walnut.h should work for you. I'd set it to a value larger 5632 than your SDRAM module. If you have a 64MB SDRAM module, set 5633 it above 400_0000. Just make sure your board has no resources 5634 that are supposed to respond to that address! That code in 5635 start.S has been around a while and should work as is when 5636 you get the config right. 5637 5638 -Chris Hallinan 5639 DS4.COM, Inc. 5640 5641It is essential to remember this, since it has some impact on the C 5642code for the initialization procedures: 5643 5644* Initialized global data (data segment) is read-only. Do not attempt 5645 to write it. 5646 5647* Do not use any uninitialized global data (or implicitly initialized 5648 as zero data - BSS segment) at all - this is undefined, initiali- 5649 zation is performed later (when relocating to RAM). 5650 5651* Stack space is very limited. Avoid big data buffers or things like 5652 that. 5653 5654Having only the stack as writable memory limits means we cannot use 5655normal global data to share information between the code. But it 5656turned out that the implementation of U-Boot can be greatly 5657simplified by making a global data structure (gd_t) available to all 5658functions. We could pass a pointer to this data as argument to _all_ 5659functions, but this would bloat the code. Instead we use a feature of 5660the GCC compiler (Global Register Variables) to share the data: we 5661place a pointer (gd) to the global data into a register which we 5662reserve for this purpose. 5663 5664When choosing a register for such a purpose we are restricted by the 5665relevant (E)ABI specifications for the current architecture, and by 5666GCC's implementation. 5667 5668For PowerPC, the following registers have specific use: 5669 R1: stack pointer 5670 R2: reserved for system use 5671 R3-R4: parameter passing and return values 5672 R5-R10: parameter passing 5673 R13: small data area pointer 5674 R30: GOT pointer 5675 R31: frame pointer 5676 5677 (U-Boot also uses R12 as internal GOT pointer. r12 5678 is a volatile register so r12 needs to be reset when 5679 going back and forth between asm and C) 5680 5681 ==> U-Boot will use R2 to hold a pointer to the global data 5682 5683 Note: on PPC, we could use a static initializer (since the 5684 address of the global data structure is known at compile time), 5685 but it turned out that reserving a register results in somewhat 5686 smaller code - although the code savings are not that big (on 5687 average for all boards 752 bytes for the whole U-Boot image, 5688 624 text + 127 data). 5689 5690On ARM, the following registers are used: 5691 5692 R0: function argument word/integer result 5693 R1-R3: function argument word 5694 R9: platform specific 5695 R10: stack limit (used only if stack checking is enabled) 5696 R11: argument (frame) pointer 5697 R12: temporary workspace 5698 R13: stack pointer 5699 R14: link register 5700 R15: program counter 5701 5702 ==> U-Boot will use R9 to hold a pointer to the global data 5703 5704 Note: on ARM, only R_ARM_RELATIVE relocations are supported. 5705 5706On Nios II, the ABI is documented here: 5707 http://www.altera.com/literature/hb/nios2/n2cpu_nii51016.pdf 5708 5709 ==> U-Boot will use gp to hold a pointer to the global data 5710 5711 Note: on Nios II, we give "-G0" option to gcc and don't use gp 5712 to access small data sections, so gp is free. 5713 5714On NDS32, the following registers are used: 5715 5716 R0-R1: argument/return 5717 R2-R5: argument 5718 R15: temporary register for assembler 5719 R16: trampoline register 5720 R28: frame pointer (FP) 5721 R29: global pointer (GP) 5722 R30: link register (LP) 5723 R31: stack pointer (SP) 5724 PC: program counter (PC) 5725 5726 ==> U-Boot will use R10 to hold a pointer to the global data 5727 5728NOTE: DECLARE_GLOBAL_DATA_PTR must be used with file-global scope, 5729or current versions of GCC may "optimize" the code too much. 5730 5731Memory Management: 5732------------------ 5733 5734U-Boot runs in system state and uses physical addresses, i.e. the 5735MMU is not used either for address mapping nor for memory protection. 5736 5737The available memory is mapped to fixed addresses using the memory 5738controller. In this process, a contiguous block is formed for each 5739memory type (Flash, SDRAM, SRAM), even when it consists of several 5740physical memory banks. 5741 5742U-Boot is installed in the first 128 kB of the first Flash bank (on 5743TQM8xxL modules this is the range 0x40000000 ... 0x4001FFFF). After 5744booting and sizing and initializing DRAM, the code relocates itself 5745to the upper end of DRAM. Immediately below the U-Boot code some 5746memory is reserved for use by malloc() [see CONFIG_SYS_MALLOC_LEN 5747configuration setting]. Below that, a structure with global Board 5748Info data is placed, followed by the stack (growing downward). 5749 5750Additionally, some exception handler code is copied to the low 8 kB 5751of DRAM (0x00000000 ... 0x00001FFF). 5752 5753So a typical memory configuration with 16 MB of DRAM could look like 5754this: 5755 5756 0x0000 0000 Exception Vector code 5757 : 5758 0x0000 1FFF 5759 0x0000 2000 Free for Application Use 5760 : 5761 : 5762 5763 : 5764 : 5765 0x00FB FF20 Monitor Stack (Growing downward) 5766 0x00FB FFAC Board Info Data and permanent copy of global data 5767 0x00FC 0000 Malloc Arena 5768 : 5769 0x00FD FFFF 5770 0x00FE 0000 RAM Copy of Monitor Code 5771 ... eventually: LCD or video framebuffer 5772 ... eventually: pRAM (Protected RAM - unchanged by reset) 5773 0x00FF FFFF [End of RAM] 5774 5775 5776System Initialization: 5777---------------------- 5778 5779In the reset configuration, U-Boot starts at the reset entry point 5780(on most PowerPC systems at address 0x00000100). Because of the reset 5781configuration for CS0# this is a mirror of the on board Flash memory. 5782To be able to re-map memory U-Boot then jumps to its link address. 5783To be able to implement the initialization code in C, a (small!) 5784initial stack is set up in the internal Dual Ported RAM (in case CPUs 5785which provide such a feature like MPC8xx or MPC8260), or in a locked 5786part of the data cache. After that, U-Boot initializes the CPU core, 5787the caches and the SIU. 5788 5789Next, all (potentially) available memory banks are mapped using a 5790preliminary mapping. For example, we put them on 512 MB boundaries 5791(multiples of 0x20000000: SDRAM on 0x00000000 and 0x20000000, Flash 5792on 0x40000000 and 0x60000000, SRAM on 0x80000000). Then UPM A is 5793programmed for SDRAM access. Using the temporary configuration, a 5794simple memory test is run that determines the size of the SDRAM 5795banks. 5796 5797When there is more than one SDRAM bank, and the banks are of 5798different size, the largest is mapped first. For equal size, the first 5799bank (CS2#) is mapped first. The first mapping is always for address 58000x00000000, with any additional banks following immediately to create 5801contiguous memory starting from 0. 5802 5803Then, the monitor installs itself at the upper end of the SDRAM area 5804and allocates memory for use by malloc() and for the global Board 5805Info data; also, the exception vector code is copied to the low RAM 5806pages, and the final stack is set up. 5807 5808Only after this relocation will you have a "normal" C environment; 5809until that you are restricted in several ways, mostly because you are 5810running from ROM, and because the code will have to be relocated to a 5811new address in RAM. 5812 5813 5814U-Boot Porting Guide: 5815---------------------- 5816 5817[Based on messages by Jerry Van Baren in the U-Boot-Users mailing 5818list, October 2002] 5819 5820 5821int main(int argc, char *argv[]) 5822{ 5823 sighandler_t no_more_time; 5824 5825 signal(SIGALRM, no_more_time); 5826 alarm(PROJECT_DEADLINE - toSec (3 * WEEK)); 5827 5828 if (available_money > available_manpower) { 5829 Pay consultant to port U-Boot; 5830 return 0; 5831 } 5832 5833 Download latest U-Boot source; 5834 5835 Subscribe to u-boot mailing list; 5836 5837 if (clueless) 5838 email("Hi, I am new to U-Boot, how do I get started?"); 5839 5840 while (learning) { 5841 Read the README file in the top level directory; 5842 Read http://www.denx.de/twiki/bin/view/DULG/Manual; 5843 Read applicable doc/*.README; 5844 Read the source, Luke; 5845 /* find . -name "*.[chS]" | xargs grep -i <keyword> */ 5846 } 5847 5848 if (available_money > toLocalCurrency ($2500)) 5849 Buy a BDI3000; 5850 else 5851 Add a lot of aggravation and time; 5852 5853 if (a similar board exists) { /* hopefully... */ 5854 cp -a board/<similar> board/<myboard> 5855 cp include/configs/<similar>.h include/configs/<myboard>.h 5856 } else { 5857 Create your own board support subdirectory; 5858 Create your own board include/configs/<myboard>.h file; 5859 } 5860 Edit new board/<myboard> files 5861 Edit new include/configs/<myboard>.h 5862 5863 while (!accepted) { 5864 while (!running) { 5865 do { 5866 Add / modify source code; 5867 } until (compiles); 5868 Debug; 5869 if (clueless) 5870 email("Hi, I am having problems..."); 5871 } 5872 Send patch file to the U-Boot email list; 5873 if (reasonable critiques) 5874 Incorporate improvements from email list code review; 5875 else 5876 Defend code as written; 5877 } 5878 5879 return 0; 5880} 5881 5882void no_more_time (int sig) 5883{ 5884 hire_a_guru(); 5885} 5886 5887 5888Coding Standards: 5889----------------- 5890 5891All contributions to U-Boot should conform to the Linux kernel 5892coding style; see the file "Documentation/CodingStyle" and the script 5893"scripts/Lindent" in your Linux kernel source directory. 5894 5895Source files originating from a different project (for example the 5896MTD subsystem) are generally exempt from these guidelines and are not 5897reformatted to ease subsequent migration to newer versions of those 5898sources. 5899 5900Please note that U-Boot is implemented in C (and to some small parts in 5901Assembler); no C++ is used, so please do not use C++ style comments (//) 5902in your code. 5903 5904Please also stick to the following formatting rules: 5905- remove any trailing white space 5906- use TAB characters for indentation and vertical alignment, not spaces 5907- make sure NOT to use DOS '\r\n' line feeds 5908- do not add more than 2 consecutive empty lines to source files 5909- do not add trailing empty lines to source files 5910 5911Submissions which do not conform to the standards may be returned 5912with a request to reformat the changes. 5913 5914 5915Submitting Patches: 5916------------------- 5917 5918Since the number of patches for U-Boot is growing, we need to 5919establish some rules. Submissions which do not conform to these rules 5920may be rejected, even when they contain important and valuable stuff. 5921 5922Please see http://www.denx.de/wiki/U-Boot/Patches for details. 5923 5924Patches shall be sent to the u-boot mailing list <u-boot@lists.denx.de>; 5925see http://lists.denx.de/mailman/listinfo/u-boot 5926 5927When you send a patch, please include the following information with 5928it: 5929 5930* For bug fixes: a description of the bug and how your patch fixes 5931 this bug. Please try to include a way of demonstrating that the 5932 patch actually fixes something. 5933 5934* For new features: a description of the feature and your 5935 implementation. 5936 5937* A CHANGELOG entry as plaintext (separate from the patch) 5938 5939* For major contributions, add a MAINTAINERS file with your 5940 information and associated file and directory references. 5941 5942* When you add support for a new board, don't forget to add a 5943 maintainer e-mail address to the boards.cfg file, too. 5944 5945* If your patch adds new configuration options, don't forget to 5946 document these in the README file. 5947 5948* The patch itself. If you are using git (which is *strongly* 5949 recommended) you can easily generate the patch using the 5950 "git format-patch". If you then use "git send-email" to send it to 5951 the U-Boot mailing list, you will avoid most of the common problems 5952 with some other mail clients. 5953 5954 If you cannot use git, use "diff -purN OLD NEW". If your version of 5955 diff does not support these options, then get the latest version of 5956 GNU diff. 5957 5958 The current directory when running this command shall be the parent 5959 directory of the U-Boot source tree (i. e. please make sure that 5960 your patch includes sufficient directory information for the 5961 affected files). 5962 5963 We prefer patches as plain text. MIME attachments are discouraged, 5964 and compressed attachments must not be used. 5965 5966* If one logical set of modifications affects or creates several 5967 files, all these changes shall be submitted in a SINGLE patch file. 5968 5969* Changesets that contain different, unrelated modifications shall be 5970 submitted as SEPARATE patches, one patch per changeset. 5971 5972 5973Notes: 5974 5975* Before sending the patch, run the buildman script on your patched 5976 source tree and make sure that no errors or warnings are reported 5977 for any of the boards. 5978 5979* Keep your modifications to the necessary minimum: A patch 5980 containing several unrelated changes or arbitrary reformats will be 5981 returned with a request to re-formatting / split it. 5982 5983* If you modify existing code, make sure that your new code does not 5984 add to the memory footprint of the code ;-) Small is beautiful! 5985 When adding new features, these should compile conditionally only 5986 (using #ifdef), and the resulting code with the new feature 5987 disabled must not need more memory than the old code without your 5988 modification. 5989 5990* Remember that there is a size limit of 100 kB per message on the 5991 u-boot mailing list. Bigger patches will be moderated. If they are 5992 reasonable and not too big, they will be acknowledged. But patches 5993 bigger than the size limit should be avoided. 5994