1# 2# (C) Copyright 2000 - 2013 3# Wolfgang Denk, DENX Software Engineering, wd@denx.de. 4# 5# SPDX-License-Identifier: GPL-2.0+ 6# 7 8Summary: 9======== 10 11This directory contains the source code for U-Boot, a boot loader for 12Embedded boards based on PowerPC, ARM, MIPS and several other 13processors, which can be installed in a boot ROM and used to 14initialize and test the hardware or to download and run application 15code. 16 17The development of U-Boot is closely related to Linux: some parts of 18the source code originate in the Linux source tree, we have some 19header files in common, and special provision has been made to 20support booting of Linux images. 21 22Some attention has been paid to make this software easily 23configurable and extendable. For instance, all monitor commands are 24implemented with the same call interface, so that it's very easy to 25add new commands. Also, instead of permanently adding rarely used 26code (for instance hardware test utilities) to the monitor, you can 27load and run it dynamically. 28 29 30Status: 31======= 32 33In general, all boards for which a configuration option exists in the 34Makefile have been tested to some extent and can be considered 35"working". In fact, many of them are used in production systems. 36 37In case of problems see the CHANGELOG file to find out who contributed 38the specific port. In addition, there are various MAINTAINERS files 39scattered throughout the U-Boot source identifying the people or 40companies responsible for various boards and subsystems. 41 42Note: As of August, 2010, there is no longer a CHANGELOG file in the 43actual U-Boot source tree; however, it can be created dynamically 44from the Git log using: 45 46 make CHANGELOG 47 48 49Where to get help: 50================== 51 52In case you have questions about, problems with or contributions for 53U-Boot, you should send a message to the U-Boot mailing list at 54<u-boot@lists.denx.de>. There is also an archive of previous traffic 55on the mailing list - please search the archive before asking FAQ's. 56Please see http://lists.denx.de/pipermail/u-boot and 57http://dir.gmane.org/gmane.comp.boot-loaders.u-boot 58 59 60Where to get source code: 61========================= 62 63The U-Boot source code is maintained in the Git repository at 64git://www.denx.de/git/u-boot.git ; you can browse it online at 65http://www.denx.de/cgi-bin/gitweb.cgi?p=u-boot.git;a=summary 66 67The "snapshot" links on this page allow you to download tarballs of 68any version you might be interested in. Official releases are also 69available for FTP download from the ftp://ftp.denx.de/pub/u-boot/ 70directory. 71 72Pre-built (and tested) images are available from 73ftp://ftp.denx.de/pub/u-boot/images/ 74 75 76Where we come from: 77=================== 78 79- start from 8xxrom sources 80- create PPCBoot project (http://sourceforge.net/projects/ppcboot) 81- clean up code 82- make it easier to add custom boards 83- make it possible to add other [PowerPC] CPUs 84- extend functions, especially: 85 * Provide extended interface to Linux boot loader 86 * S-Record download 87 * network boot 88 * PCMCIA / CompactFlash / ATA disk / SCSI ... boot 89- create ARMBoot project (http://sourceforge.net/projects/armboot) 90- add other CPU families (starting with ARM) 91- create U-Boot project (http://sourceforge.net/projects/u-boot) 92- current project page: see http://www.denx.de/wiki/U-Boot 93 94 95Names and Spelling: 96=================== 97 98The "official" name of this project is "Das U-Boot". The spelling 99"U-Boot" shall be used in all written text (documentation, comments 100in source files etc.). Example: 101 102 This is the README file for the U-Boot project. 103 104File names etc. shall be based on the string "u-boot". Examples: 105 106 include/asm-ppc/u-boot.h 107 108 #include <asm/u-boot.h> 109 110Variable names, preprocessor constants etc. shall be either based on 111the string "u_boot" or on "U_BOOT". Example: 112 113 U_BOOT_VERSION u_boot_logo 114 IH_OS_U_BOOT u_boot_hush_start 115 116 117Versioning: 118=========== 119 120Starting with the release in October 2008, the names of the releases 121were changed from numerical release numbers without deeper meaning 122into a time stamp based numbering. Regular releases are identified by 123names consisting of the calendar year and month of the release date. 124Additional fields (if present) indicate release candidates or bug fix 125releases in "stable" maintenance trees. 126 127Examples: 128 U-Boot v2009.11 - Release November 2009 129 U-Boot v2009.11.1 - Release 1 in version November 2009 stable tree 130 U-Boot v2010.09-rc1 - Release candidate 1 for September 2010 release 131 132 133Directory Hierarchy: 134==================== 135 136/arch Architecture specific files 137 /arc Files generic to ARC architecture 138 /arm Files generic to ARM architecture 139 /avr32 Files generic to AVR32 architecture 140 /m68k Files generic to m68k architecture 141 /microblaze Files generic to microblaze architecture 142 /mips Files generic to MIPS architecture 143 /nds32 Files generic to NDS32 architecture 144 /nios2 Files generic to Altera NIOS2 architecture 145 /openrisc Files generic to OpenRISC architecture 146 /powerpc Files generic to PowerPC architecture 147 /sandbox Files generic to HW-independent "sandbox" 148 /sh Files generic to SH architecture 149 /x86 Files generic to x86 architecture 150/api Machine/arch independent API for external apps 151/board Board dependent files 152/cmd U-Boot commands functions 153/common Misc architecture independent functions 154/configs Board default configuration files 155/disk Code for disk drive partition handling 156/doc Documentation (don't expect too much) 157/drivers Commonly used device drivers 158/dts Contains Makefile for building internal U-Boot fdt. 159/examples Example code for standalone applications, etc. 160/fs Filesystem code (cramfs, ext2, jffs2, etc.) 161/include Header Files 162/lib Library routines generic to all architectures 163/Licenses Various license files 164/net Networking code 165/post Power On Self Test 166/scripts Various build scripts and Makefiles 167/test Various unit test files 168/tools Tools to build S-Record or U-Boot images, etc. 169 170Software Configuration: 171======================= 172 173Configuration is usually done using C preprocessor defines; the 174rationale behind that is to avoid dead code whenever possible. 175 176There are two classes of configuration variables: 177 178* Configuration _OPTIONS_: 179 These are selectable by the user and have names beginning with 180 "CONFIG_". 181 182* Configuration _SETTINGS_: 183 These depend on the hardware etc. and should not be meddled with if 184 you don't know what you're doing; they have names beginning with 185 "CONFIG_SYS_". 186 187Previously, all configuration was done by hand, which involved creating 188symbolic links and editing configuration files manually. More recently, 189U-Boot has added the Kbuild infrastructure used by the Linux kernel, 190allowing you to use the "make menuconfig" command to configure your 191build. 192 193 194Selection of Processor Architecture and Board Type: 195--------------------------------------------------- 196 197For all supported boards there are ready-to-use default 198configurations available; just type "make <board_name>_defconfig". 199 200Example: For a TQM823L module type: 201 202 cd u-boot 203 make TQM823L_defconfig 204 205Note: If you're looking for the default configuration file for a board 206you're sure used to be there but is now missing, check the file 207doc/README.scrapyard for a list of no longer supported boards. 208 209Sandbox Environment: 210-------------------- 211 212U-Boot can be built natively to run on a Linux host using the 'sandbox' 213board. This allows feature development which is not board- or architecture- 214specific to be undertaken on a native platform. The sandbox is also used to 215run some of U-Boot's tests. 216 217See board/sandbox/README.sandbox for more details. 218 219 220Board Initialisation Flow: 221-------------------------- 222 223This is the intended start-up flow for boards. This should apply for both 224SPL and U-Boot proper (i.e. they both follow the same rules). 225 226Note: "SPL" stands for "Secondary Program Loader," which is explained in 227more detail later in this file. 228 229At present, SPL mostly uses a separate code path, but the function names 230and roles of each function are the same. Some boards or architectures 231may not conform to this. At least most ARM boards which use 232CONFIG_SPL_FRAMEWORK conform to this. 233 234Execution typically starts with an architecture-specific (and possibly 235CPU-specific) start.S file, such as: 236 237 - arch/arm/cpu/armv7/start.S 238 - arch/powerpc/cpu/mpc83xx/start.S 239 - arch/mips/cpu/start.S 240 241and so on. From there, three functions are called; the purpose and 242limitations of each of these functions are described below. 243 244lowlevel_init(): 245 - purpose: essential init to permit execution to reach board_init_f() 246 - no global_data or BSS 247 - there is no stack (ARMv7 may have one but it will soon be removed) 248 - must not set up SDRAM or use console 249 - must only do the bare minimum to allow execution to continue to 250 board_init_f() 251 - this is almost never needed 252 - return normally from this function 253 254board_init_f(): 255 - purpose: set up the machine ready for running board_init_r(): 256 i.e. SDRAM and serial UART 257 - global_data is available 258 - stack is in SRAM 259 - BSS is not available, so you cannot use global/static variables, 260 only stack variables and global_data 261 262 Non-SPL-specific notes: 263 - dram_init() is called to set up DRAM. If already done in SPL this 264 can do nothing 265 266 SPL-specific notes: 267 - you can override the entire board_init_f() function with your own 268 version as needed. 269 - preloader_console_init() can be called here in extremis 270 - should set up SDRAM, and anything needed to make the UART work 271 - these is no need to clear BSS, it will be done by crt0.S 272 - must return normally from this function (don't call board_init_r() 273 directly) 274 275Here the BSS is cleared. For SPL, if CONFIG_SPL_STACK_R is defined, then at 276this point the stack and global_data are relocated to below 277CONFIG_SPL_STACK_R_ADDR. For non-SPL, U-Boot is relocated to run at the top of 278memory. 279 280board_init_r(): 281 - purpose: main execution, common code 282 - global_data is available 283 - SDRAM is available 284 - BSS is available, all static/global variables can be used 285 - execution eventually continues to main_loop() 286 287 Non-SPL-specific notes: 288 - U-Boot is relocated to the top of memory and is now running from 289 there. 290 291 SPL-specific notes: 292 - stack is optionally in SDRAM, if CONFIG_SPL_STACK_R is defined and 293 CONFIG_SPL_STACK_R_ADDR points into SDRAM 294 - preloader_console_init() can be called here - typically this is 295 done by selecting CONFIG_SPL_BOARD_INIT and then supplying a 296 spl_board_init() function containing this call 297 - loads U-Boot or (in falcon mode) Linux 298 299 300 301Configuration Options: 302---------------------- 303 304Configuration depends on the combination of board and CPU type; all 305such information is kept in a configuration file 306"include/configs/<board_name>.h". 307 308Example: For a TQM823L module, all configuration settings are in 309"include/configs/TQM823L.h". 310 311 312Many of the options are named exactly as the corresponding Linux 313kernel configuration options. The intention is to make it easier to 314build a config tool - later. 315 316 317The following options need to be configured: 318 319- CPU Type: Define exactly one, e.g. CONFIG_MPC85XX. 320 321- Board Type: Define exactly one, e.g. CONFIG_MPC8540ADS. 322 323- CPU Daughterboard Type: (if CONFIG_ATSTK1000 is defined) 324 Define exactly one, e.g. CONFIG_ATSTK1002 325 326- Marvell Family Member 327 CONFIG_SYS_MVFS - define it if you want to enable 328 multiple fs option at one time 329 for marvell soc family 330 331- 8xx CPU Options: (if using an MPC8xx CPU) 332 CONFIG_8xx_GCLK_FREQ - deprecated: CPU clock if 333 get_gclk_freq() cannot work 334 e.g. if there is no 32KHz 335 reference PIT/RTC clock 336 CONFIG_8xx_OSCLK - PLL input clock (either EXTCLK 337 or XTAL/EXTAL) 338 339- 859/866/885 CPU options: (if using a MPC859 or MPC866 or MPC885 CPU): 340 CONFIG_SYS_8xx_CPUCLK_MIN 341 CONFIG_SYS_8xx_CPUCLK_MAX 342 CONFIG_8xx_CPUCLK_DEFAULT 343 See doc/README.MPC866 344 345 CONFIG_SYS_MEASURE_CPUCLK 346 347 Define this to measure the actual CPU clock instead 348 of relying on the correctness of the configured 349 values. Mostly useful for board bringup to make sure 350 the PLL is locked at the intended frequency. Note 351 that this requires a (stable) reference clock (32 kHz 352 RTC clock or CONFIG_SYS_8XX_XIN) 353 354 CONFIG_SYS_DELAYED_ICACHE 355 356 Define this option if you want to enable the 357 ICache only when Code runs from RAM. 358 359- 85xx CPU Options: 360 CONFIG_SYS_PPC64 361 362 Specifies that the core is a 64-bit PowerPC implementation (implements 363 the "64" category of the Power ISA). This is necessary for ePAPR 364 compliance, among other possible reasons. 365 366 CONFIG_SYS_FSL_TBCLK_DIV 367 368 Defines the core time base clock divider ratio compared to the 369 system clock. On most PQ3 devices this is 8, on newer QorIQ 370 devices it can be 16 or 32. The ratio varies from SoC to Soc. 371 372 CONFIG_SYS_FSL_PCIE_COMPAT 373 374 Defines the string to utilize when trying to match PCIe device 375 tree nodes for the given platform. 376 377 CONFIG_SYS_FSL_ERRATUM_A004510 378 379 Enables a workaround for erratum A004510. If set, 380 then CONFIG_SYS_FSL_ERRATUM_A004510_SVR_REV and 381 CONFIG_SYS_FSL_CORENET_SNOOPVEC_COREONLY must be set. 382 383 CONFIG_SYS_FSL_ERRATUM_A004510_SVR_REV 384 CONFIG_SYS_FSL_ERRATUM_A004510_SVR_REV2 (optional) 385 386 Defines one or two SoC revisions (low 8 bits of SVR) 387 for which the A004510 workaround should be applied. 388 389 The rest of SVR is either not relevant to the decision 390 of whether the erratum is present (e.g. p2040 versus 391 p2041) or is implied by the build target, which controls 392 whether CONFIG_SYS_FSL_ERRATUM_A004510 is set. 393 394 See Freescale App Note 4493 for more information about 395 this erratum. 396 397 CONFIG_A003399_NOR_WORKAROUND 398 Enables a workaround for IFC erratum A003399. It is only 399 required during NOR boot. 400 401 CONFIG_A008044_WORKAROUND 402 Enables a workaround for T1040/T1042 erratum A008044. It is only 403 required during NAND boot and valid for Rev 1.0 SoC revision 404 405 CONFIG_SYS_FSL_CORENET_SNOOPVEC_COREONLY 406 407 This is the value to write into CCSR offset 0x18600 408 according to the A004510 workaround. 409 410 CONFIG_SYS_FSL_DSP_DDR_ADDR 411 This value denotes start offset of DDR memory which is 412 connected exclusively to the DSP cores. 413 414 CONFIG_SYS_FSL_DSP_M2_RAM_ADDR 415 This value denotes start offset of M2 memory 416 which is directly connected to the DSP core. 417 418 CONFIG_SYS_FSL_DSP_M3_RAM_ADDR 419 This value denotes start offset of M3 memory which is directly 420 connected to the DSP core. 421 422 CONFIG_SYS_FSL_DSP_CCSRBAR_DEFAULT 423 This value denotes start offset of DSP CCSR space. 424 425 CONFIG_SYS_FSL_SINGLE_SOURCE_CLK 426 Single Source Clock is clocking mode present in some of FSL SoC's. 427 In this mode, a single differential clock is used to supply 428 clocks to the sysclock, ddrclock and usbclock. 429 430 CONFIG_SYS_CPC_REINIT_F 431 This CONFIG is defined when the CPC is configured as SRAM at the 432 time of U-Boot entry and is required to be re-initialized. 433 434 CONFIG_DEEP_SLEEP 435 Indicates this SoC supports deep sleep feature. If deep sleep is 436 supported, core will start to execute uboot when wakes up. 437 438- Generic CPU options: 439 CONFIG_SYS_GENERIC_GLOBAL_DATA 440 Defines global data is initialized in generic board board_init_f(). 441 If this macro is defined, global data is created and cleared in 442 generic board board_init_f(). Without this macro, architecture/board 443 should initialize global data before calling board_init_f(). 444 445 CONFIG_SYS_BIG_ENDIAN, CONFIG_SYS_LITTLE_ENDIAN 446 447 Defines the endianess of the CPU. Implementation of those 448 values is arch specific. 449 450 CONFIG_SYS_FSL_DDR 451 Freescale DDR driver in use. This type of DDR controller is 452 found in mpc83xx, mpc85xx, mpc86xx as well as some ARM core 453 SoCs. 454 455 CONFIG_SYS_FSL_DDR_ADDR 456 Freescale DDR memory-mapped register base. 457 458 CONFIG_SYS_FSL_DDR_EMU 459 Specify emulator support for DDR. Some DDR features such as 460 deskew training are not available. 461 462 CONFIG_SYS_FSL_DDRC_GEN1 463 Freescale DDR1 controller. 464 465 CONFIG_SYS_FSL_DDRC_GEN2 466 Freescale DDR2 controller. 467 468 CONFIG_SYS_FSL_DDRC_GEN3 469 Freescale DDR3 controller. 470 471 CONFIG_SYS_FSL_DDRC_GEN4 472 Freescale DDR4 controller. 473 474 CONFIG_SYS_FSL_DDRC_ARM_GEN3 475 Freescale DDR3 controller for ARM-based SoCs. 476 477 CONFIG_SYS_FSL_DDR1 478 Board config to use DDR1. It can be enabled for SoCs with 479 Freescale DDR1 or DDR2 controllers, depending on the board 480 implemetation. 481 482 CONFIG_SYS_FSL_DDR2 483 Board config to use DDR2. It can be enabled for SoCs with 484 Freescale DDR2 or DDR3 controllers, depending on the board 485 implementation. 486 487 CONFIG_SYS_FSL_DDR3 488 Board config to use DDR3. It can be enabled for SoCs with 489 Freescale DDR3 or DDR3L controllers. 490 491 CONFIG_SYS_FSL_DDR3L 492 Board config to use DDR3L. It can be enabled for SoCs with 493 DDR3L controllers. 494 495 CONFIG_SYS_FSL_DDR4 496 Board config to use DDR4. It can be enabled for SoCs with 497 DDR4 controllers. 498 499 CONFIG_SYS_FSL_IFC_BE 500 Defines the IFC controller register space as Big Endian 501 502 CONFIG_SYS_FSL_IFC_LE 503 Defines the IFC controller register space as Little Endian 504 505 CONFIG_SYS_FSL_IFC_CLK_DIV 506 Defines divider of platform clock(clock input to IFC controller). 507 508 CONFIG_SYS_FSL_LBC_CLK_DIV 509 Defines divider of platform clock(clock input to eLBC controller). 510 511 CONFIG_SYS_FSL_PBL_PBI 512 It enables addition of RCW (Power on reset configuration) in built image. 513 Please refer doc/README.pblimage for more details 514 515 CONFIG_SYS_FSL_PBL_RCW 516 It adds PBI(pre-boot instructions) commands in u-boot build image. 517 PBI commands can be used to configure SoC before it starts the execution. 518 Please refer doc/README.pblimage for more details 519 520 CONFIG_SPL_FSL_PBL 521 It adds a target to create boot binary having SPL binary in PBI format 522 concatenated with u-boot binary. 523 524 CONFIG_SYS_FSL_DDR_BE 525 Defines the DDR controller register space as Big Endian 526 527 CONFIG_SYS_FSL_DDR_LE 528 Defines the DDR controller register space as Little Endian 529 530 CONFIG_SYS_FSL_DDR_SDRAM_BASE_PHY 531 Physical address from the view of DDR controllers. It is the 532 same as CONFIG_SYS_DDR_SDRAM_BASE for all Power SoCs. But 533 it could be different for ARM SoCs. 534 535 CONFIG_SYS_FSL_DDR_INTLV_256B 536 DDR controller interleaving on 256-byte. This is a special 537 interleaving mode, handled by Dickens for Freescale layerscape 538 SoCs with ARM core. 539 540 CONFIG_SYS_FSL_DDR_MAIN_NUM_CTRLS 541 Number of controllers used as main memory. 542 543 CONFIG_SYS_FSL_OTHER_DDR_NUM_CTRLS 544 Number of controllers used for other than main memory. 545 546 CONFIG_SYS_FSL_HAS_DP_DDR 547 Defines the SoC has DP-DDR used for DPAA. 548 549 CONFIG_SYS_FSL_SEC_BE 550 Defines the SEC controller register space as Big Endian 551 552 CONFIG_SYS_FSL_SEC_LE 553 Defines the SEC controller register space as Little Endian 554 555- MIPS CPU options: 556 CONFIG_SYS_INIT_SP_OFFSET 557 558 Offset relative to CONFIG_SYS_SDRAM_BASE for initial stack 559 pointer. This is needed for the temporary stack before 560 relocation. 561 562 CONFIG_SYS_MIPS_CACHE_MODE 563 564 Cache operation mode for the MIPS CPU. 565 See also arch/mips/include/asm/mipsregs.h. 566 Possible values are: 567 CONF_CM_CACHABLE_NO_WA 568 CONF_CM_CACHABLE_WA 569 CONF_CM_UNCACHED 570 CONF_CM_CACHABLE_NONCOHERENT 571 CONF_CM_CACHABLE_CE 572 CONF_CM_CACHABLE_COW 573 CONF_CM_CACHABLE_CUW 574 CONF_CM_CACHABLE_ACCELERATED 575 576 CONFIG_SYS_XWAY_EBU_BOOTCFG 577 578 Special option for Lantiq XWAY SoCs for booting from NOR flash. 579 See also arch/mips/cpu/mips32/start.S. 580 581 CONFIG_XWAY_SWAP_BYTES 582 583 Enable compilation of tools/xway-swap-bytes needed for Lantiq 584 XWAY SoCs for booting from NOR flash. The U-Boot image needs to 585 be swapped if a flash programmer is used. 586 587- ARM options: 588 CONFIG_SYS_EXCEPTION_VECTORS_HIGH 589 590 Select high exception vectors of the ARM core, e.g., do not 591 clear the V bit of the c1 register of CP15. 592 593 COUNTER_FREQUENCY 594 Generic timer clock source frequency. 595 596 COUNTER_FREQUENCY_REAL 597 Generic timer clock source frequency if the real clock is 598 different from COUNTER_FREQUENCY, and can only be determined 599 at run time. 600 601- Tegra SoC options: 602 CONFIG_TEGRA_SUPPORT_NON_SECURE 603 604 Support executing U-Boot in non-secure (NS) mode. Certain 605 impossible actions will be skipped if the CPU is in NS mode, 606 such as ARM architectural timer initialization. 607 608- Linux Kernel Interface: 609 CONFIG_CLOCKS_IN_MHZ 610 611 U-Boot stores all clock information in Hz 612 internally. For binary compatibility with older Linux 613 kernels (which expect the clocks passed in the 614 bd_info data to be in MHz) the environment variable 615 "clocks_in_mhz" can be defined so that U-Boot 616 converts clock data to MHZ before passing it to the 617 Linux kernel. 618 When CONFIG_CLOCKS_IN_MHZ is defined, a definition of 619 "clocks_in_mhz=1" is automatically included in the 620 default environment. 621 622 CONFIG_MEMSIZE_IN_BYTES [relevant for MIPS only] 623 624 When transferring memsize parameter to Linux, some versions 625 expect it to be in bytes, others in MB. 626 Define CONFIG_MEMSIZE_IN_BYTES to make it in bytes. 627 628 CONFIG_OF_LIBFDT 629 630 New kernel versions are expecting firmware settings to be 631 passed using flattened device trees (based on open firmware 632 concepts). 633 634 CONFIG_OF_LIBFDT 635 * New libfdt-based support 636 * Adds the "fdt" command 637 * The bootm command automatically updates the fdt 638 639 OF_CPU - The proper name of the cpus node (only required for 640 MPC512X and MPC5xxx based boards). 641 OF_SOC - The proper name of the soc node (only required for 642 MPC512X and MPC5xxx based boards). 643 OF_TBCLK - The timebase frequency. 644 OF_STDOUT_PATH - The path to the console device 645 646 boards with QUICC Engines require OF_QE to set UCC MAC 647 addresses 648 649 CONFIG_OF_BOARD_SETUP 650 651 Board code has addition modification that it wants to make 652 to the flat device tree before handing it off to the kernel 653 654 CONFIG_OF_SYSTEM_SETUP 655 656 Other code has addition modification that it wants to make 657 to the flat device tree before handing it off to the kernel. 658 This causes ft_system_setup() to be called before booting 659 the kernel. 660 661 CONFIG_OF_IDE_FIXUP 662 663 U-Boot can detect if an IDE device is present or not. 664 If not, and this new config option is activated, U-Boot 665 removes the ATA node from the DTS before booting Linux, 666 so the Linux IDE driver does not probe the device and 667 crash. This is needed for buggy hardware (uc101) where 668 no pull down resistor is connected to the signal IDE5V_DD7. 669 670 CONFIG_MACH_TYPE [relevant for ARM only][mandatory] 671 672 This setting is mandatory for all boards that have only one 673 machine type and must be used to specify the machine type 674 number as it appears in the ARM machine registry 675 (see http://www.arm.linux.org.uk/developer/machines/). 676 Only boards that have multiple machine types supported 677 in a single configuration file and the machine type is 678 runtime discoverable, do not have to use this setting. 679 680- vxWorks boot parameters: 681 682 bootvx constructs a valid bootline using the following 683 environments variables: bootdev, bootfile, ipaddr, netmask, 684 serverip, gatewayip, hostname, othbootargs. 685 It loads the vxWorks image pointed bootfile. 686 687 Note: If a "bootargs" environment is defined, it will overwride 688 the defaults discussed just above. 689 690- Cache Configuration: 691 CONFIG_SYS_ICACHE_OFF - Do not enable instruction cache in U-Boot 692 CONFIG_SYS_DCACHE_OFF - Do not enable data cache in U-Boot 693 CONFIG_SYS_L2CACHE_OFF- Do not enable L2 cache in U-Boot 694 695- Cache Configuration for ARM: 696 CONFIG_SYS_L2_PL310 - Enable support for ARM PL310 L2 cache 697 controller 698 CONFIG_SYS_PL310_BASE - Physical base address of PL310 699 controller register space 700 701- Serial Ports: 702 CONFIG_PL010_SERIAL 703 704 Define this if you want support for Amba PrimeCell PL010 UARTs. 705 706 CONFIG_PL011_SERIAL 707 708 Define this if you want support for Amba PrimeCell PL011 UARTs. 709 710 CONFIG_PL011_CLOCK 711 712 If you have Amba PrimeCell PL011 UARTs, set this variable to 713 the clock speed of the UARTs. 714 715 CONFIG_PL01x_PORTS 716 717 If you have Amba PrimeCell PL010 or PL011 UARTs on your board, 718 define this to a list of base addresses for each (supported) 719 port. See e.g. include/configs/versatile.h 720 721 CONFIG_SERIAL_HW_FLOW_CONTROL 722 723 Define this variable to enable hw flow control in serial driver. 724 Current user of this option is drivers/serial/nsl16550.c driver 725 726- Console Interface: 727 Depending on board, define exactly one serial port 728 (like CONFIG_8xx_CONS_SMC1, CONFIG_8xx_CONS_SMC2, 729 CONFIG_8xx_CONS_SCC1, ...), or switch off the serial 730 console by defining CONFIG_8xx_CONS_NONE 731 732 Note: if CONFIG_8xx_CONS_NONE is defined, the serial 733 port routines must be defined elsewhere 734 (i.e. serial_init(), serial_getc(), ...) 735 736- Console Baudrate: 737 CONFIG_BAUDRATE - in bps 738 Select one of the baudrates listed in 739 CONFIG_SYS_BAUDRATE_TABLE, see below. 740 CONFIG_SYS_BRGCLK_PRESCALE, baudrate prescale 741 742- Console Rx buffer length 743 With CONFIG_SYS_SMC_RXBUFLEN it is possible to define 744 the maximum receive buffer length for the SMC. 745 This option is actual only for 82xx and 8xx possible. 746 If using CONFIG_SYS_SMC_RXBUFLEN also CONFIG_SYS_MAXIDLE 747 must be defined, to setup the maximum idle timeout for 748 the SMC. 749 750- Autoboot Command: 751 CONFIG_BOOTCOMMAND 752 Only needed when CONFIG_BOOTDELAY is enabled; 753 define a command string that is automatically executed 754 when no character is read on the console interface 755 within "Boot Delay" after reset. 756 757 CONFIG_BOOTARGS 758 This can be used to pass arguments to the bootm 759 command. The value of CONFIG_BOOTARGS goes into the 760 environment value "bootargs". 761 762 CONFIG_RAMBOOT and CONFIG_NFSBOOT 763 The value of these goes into the environment as 764 "ramboot" and "nfsboot" respectively, and can be used 765 as a convenience, when switching between booting from 766 RAM and NFS. 767 768- Bootcount: 769 CONFIG_BOOTCOUNT_LIMIT 770 Implements a mechanism for detecting a repeating reboot 771 cycle, see: 772 http://www.denx.de/wiki/view/DULG/UBootBootCountLimit 773 774 CONFIG_BOOTCOUNT_ENV 775 If no softreset save registers are found on the hardware 776 "bootcount" is stored in the environment. To prevent a 777 saveenv on all reboots, the environment variable 778 "upgrade_available" is used. If "upgrade_available" is 779 0, "bootcount" is always 0, if "upgrade_available" is 780 1 "bootcount" is incremented in the environment. 781 So the Userspace Applikation must set the "upgrade_available" 782 and "bootcount" variable to 0, if a boot was successfully. 783 784- Pre-Boot Commands: 785 CONFIG_PREBOOT 786 787 When this option is #defined, the existence of the 788 environment variable "preboot" will be checked 789 immediately before starting the CONFIG_BOOTDELAY 790 countdown and/or running the auto-boot command resp. 791 entering interactive mode. 792 793 This feature is especially useful when "preboot" is 794 automatically generated or modified. For an example 795 see the LWMON board specific code: here "preboot" is 796 modified when the user holds down a certain 797 combination of keys on the (special) keyboard when 798 booting the systems 799 800- Serial Download Echo Mode: 801 CONFIG_LOADS_ECHO 802 If defined to 1, all characters received during a 803 serial download (using the "loads" command) are 804 echoed back. This might be needed by some terminal 805 emulations (like "cu"), but may as well just take 806 time on others. This setting #define's the initial 807 value of the "loads_echo" environment variable. 808 809- Kgdb Serial Baudrate: (if CONFIG_CMD_KGDB is defined) 810 CONFIG_KGDB_BAUDRATE 811 Select one of the baudrates listed in 812 CONFIG_SYS_BAUDRATE_TABLE, see below. 813 814- Monitor Functions: 815 Monitor commands can be included or excluded 816 from the build by using the #include files 817 <config_cmd_all.h> and #undef'ing unwanted 818 commands, or adding #define's for wanted commands. 819 820 The default command configuration includes all commands 821 except those marked below with a "*". 822 823 CONFIG_CMD_AES AES 128 CBC encrypt/decrypt 824 CONFIG_CMD_ASKENV * ask for env variable 825 CONFIG_CMD_BDI bdinfo 826 CONFIG_CMD_BOOTD bootd 827 CONFIG_CMD_BOOTI * ARM64 Linux kernel Image support 828 CONFIG_CMD_CACHE * icache, dcache 829 CONFIG_CMD_CONSOLE coninfo 830 CONFIG_CMD_CRC32 * crc32 831 CONFIG_CMD_DHCP * DHCP support 832 CONFIG_CMD_DIAG * Diagnostics 833 CONFIG_CMD_ECHO echo arguments 834 CONFIG_CMD_EDITENV edit env variable 835 CONFIG_CMD_ELF * bootelf, bootvx 836 CONFIG_CMD_ENV_EXISTS * check existence of env variable 837 CONFIG_CMD_EXPORTENV * export the environment 838 CONFIG_CMD_EXT2 * ext2 command support 839 CONFIG_CMD_EXT4 * ext4 command support 840 CONFIG_CMD_FS_GENERIC * filesystem commands (e.g. load, ls) 841 that work for multiple fs types 842 CONFIG_CMD_FS_UUID * Look up a filesystem UUID 843 CONFIG_CMD_SAVEENV saveenv 844 CONFIG_CMD_FAT * FAT command support 845 CONFIG_CMD_FLASH flinfo, erase, protect 846 CONFIG_CMD_FPGA FPGA device initialization support 847 CONFIG_CMD_GO * the 'go' command (exec code) 848 CONFIG_CMD_GREPENV * search environment 849 CONFIG_CMD_I2C * I2C serial bus support 850 CONFIG_CMD_IMI iminfo 851 CONFIG_CMD_IMLS List all images found in NOR flash 852 CONFIG_CMD_IMLS_NAND * List all images found in NAND flash 853 CONFIG_CMD_IMPORTENV * import an environment 854 CONFIG_CMD_INI * import data from an ini file into the env 855 CONFIG_CMD_IRQ * irqinfo 856 CONFIG_CMD_ITEST Integer/string test of 2 values 857 CONFIG_CMD_KGDB * kgdb 858 CONFIG_CMD_LDRINFO * ldrinfo (display Blackfin loader) 859 CONFIG_CMD_LINK_LOCAL * link-local IP address auto-configuration 860 (169.254.*.*) 861 CONFIG_CMD_LOADB loadb 862 CONFIG_CMD_LOADS loads 863 CONFIG_CMD_MD5SUM * print md5 message digest 864 (requires CONFIG_CMD_MEMORY and CONFIG_MD5) 865 CONFIG_CMD_MEMINFO * Display detailed memory information 866 CONFIG_CMD_MEMORY md, mm, nm, mw, cp, cmp, crc, base, 867 loop, loopw 868 CONFIG_CMD_MEMTEST * mtest 869 CONFIG_CMD_MISC Misc functions like sleep etc 870 CONFIG_CMD_MMC * MMC memory mapped support 871 CONFIG_CMD_MII * MII utility commands 872 CONFIG_CMD_MTDPARTS * MTD partition support 873 CONFIG_CMD_NAND * NAND support 874 CONFIG_CMD_NET bootp, tftpboot, rarpboot 875 CONFIG_CMD_NFS NFS support 876 CONFIG_CMD_PCA953X * PCA953x I2C gpio commands 877 CONFIG_CMD_PCA953X_INFO * PCA953x I2C gpio info command 878 CONFIG_CMD_PCI * pciinfo 879 CONFIG_CMD_PCMCIA * PCMCIA support 880 CONFIG_CMD_PING * send ICMP ECHO_REQUEST to network 881 host 882 CONFIG_CMD_PORTIO * Port I/O 883 CONFIG_CMD_READ * Read raw data from partition 884 CONFIG_CMD_REGINFO * Register dump 885 CONFIG_CMD_RUN run command in env variable 886 CONFIG_CMD_SANDBOX * sb command to access sandbox features 887 CONFIG_CMD_SAVES * save S record dump 888 CONFIG_SCSI * SCSI Support 889 CONFIG_CMD_SDRAM * print SDRAM configuration information 890 (requires CONFIG_CMD_I2C) 891 CONFIG_CMD_SETGETDCR Support for DCR Register access 892 (4xx only) 893 CONFIG_CMD_SF * Read/write/erase SPI NOR flash 894 CONFIG_CMD_SHA1SUM * print sha1 memory digest 895 (requires CONFIG_CMD_MEMORY) 896 CONFIG_CMD_SOFTSWITCH * Soft switch setting command for BF60x 897 CONFIG_CMD_SOURCE "source" command Support 898 CONFIG_CMD_SPI * SPI serial bus support 899 CONFIG_CMD_TFTPSRV * TFTP transfer in server mode 900 CONFIG_CMD_TFTPPUT * TFTP put command (upload) 901 CONFIG_CMD_TIME * run command and report execution time (ARM specific) 902 CONFIG_CMD_TIMER * access to the system tick timer 903 CONFIG_CMD_USB * USB support 904 CONFIG_CMD_CDP * Cisco Discover Protocol support 905 CONFIG_CMD_MFSL * Microblaze FSL support 906 CONFIG_CMD_XIMG Load part of Multi Image 907 CONFIG_CMD_UUID * Generate random UUID or GUID string 908 909 EXAMPLE: If you want all functions except of network 910 support you can write: 911 912 #include "config_cmd_all.h" 913 #undef CONFIG_CMD_NET 914 915 Other Commands: 916 fdt (flattened device tree) command: CONFIG_OF_LIBFDT 917 918 Note: Don't enable the "icache" and "dcache" commands 919 (configuration option CONFIG_CMD_CACHE) unless you know 920 what you (and your U-Boot users) are doing. Data 921 cache cannot be enabled on systems like the 8xx or 922 8260 (where accesses to the IMMR region must be 923 uncached), and it cannot be disabled on all other 924 systems where we (mis-) use the data cache to hold an 925 initial stack and some data. 926 927 928 XXX - this list needs to get updated! 929 930- Removal of commands 931 If no commands are needed to boot, you can disable 932 CONFIG_CMDLINE to remove them. In this case, the command line 933 will not be available, and when U-Boot wants to execute the 934 boot command (on start-up) it will call board_run_command() 935 instead. This can reduce image size significantly for very 936 simple boot procedures. 937 938- Regular expression support: 939 CONFIG_REGEX 940 If this variable is defined, U-Boot is linked against 941 the SLRE (Super Light Regular Expression) library, 942 which adds regex support to some commands, as for 943 example "env grep" and "setexpr". 944 945- Device tree: 946 CONFIG_OF_CONTROL 947 If this variable is defined, U-Boot will use a device tree 948 to configure its devices, instead of relying on statically 949 compiled #defines in the board file. This option is 950 experimental and only available on a few boards. The device 951 tree is available in the global data as gd->fdt_blob. 952 953 U-Boot needs to get its device tree from somewhere. This can 954 be done using one of the three options below: 955 956 CONFIG_OF_EMBED 957 If this variable is defined, U-Boot will embed a device tree 958 binary in its image. This device tree file should be in the 959 board directory and called <soc>-<board>.dts. The binary file 960 is then picked up in board_init_f() and made available through 961 the global data structure as gd->blob. 962 963 CONFIG_OF_SEPARATE 964 If this variable is defined, U-Boot will build a device tree 965 binary. It will be called u-boot.dtb. Architecture-specific 966 code will locate it at run-time. Generally this works by: 967 968 cat u-boot.bin u-boot.dtb >image.bin 969 970 and in fact, U-Boot does this for you, creating a file called 971 u-boot-dtb.bin which is useful in the common case. You can 972 still use the individual files if you need something more 973 exotic. 974 975 CONFIG_OF_BOARD 976 If this variable is defined, U-Boot will use the device tree 977 provided by the board at runtime instead of embedding one with 978 the image. Only boards defining board_fdt_blob_setup() support 979 this option (see include/fdtdec.h file). 980 981- Watchdog: 982 CONFIG_WATCHDOG 983 If this variable is defined, it enables watchdog 984 support for the SoC. There must be support in the SoC 985 specific code for a watchdog. For the 8xx and 8260 986 CPUs, the SIU Watchdog feature is enabled in the SYPCR 987 register. When supported for a specific SoC is 988 available, then no further board specific code should 989 be needed to use it. 990 991 CONFIG_HW_WATCHDOG 992 When using a watchdog circuitry external to the used 993 SoC, then define this variable and provide board 994 specific code for the "hw_watchdog_reset" function. 995 996 CONFIG_AT91_HW_WDT_TIMEOUT 997 specify the timeout in seconds. default 2 seconds. 998 999- U-Boot Version: 1000 CONFIG_VERSION_VARIABLE 1001 If this variable is defined, an environment variable 1002 named "ver" is created by U-Boot showing the U-Boot 1003 version as printed by the "version" command. 1004 Any change to this variable will be reverted at the 1005 next reset. 1006 1007- Real-Time Clock: 1008 1009 When CONFIG_CMD_DATE is selected, the type of the RTC 1010 has to be selected, too. Define exactly one of the 1011 following options: 1012 1013 CONFIG_RTC_MPC8xx - use internal RTC of MPC8xx 1014 CONFIG_RTC_PCF8563 - use Philips PCF8563 RTC 1015 CONFIG_RTC_MC13XXX - use MC13783 or MC13892 RTC 1016 CONFIG_RTC_MC146818 - use MC146818 RTC 1017 CONFIG_RTC_DS1307 - use Maxim, Inc. DS1307 RTC 1018 CONFIG_RTC_DS1337 - use Maxim, Inc. DS1337 RTC 1019 CONFIG_RTC_DS1338 - use Maxim, Inc. DS1338 RTC 1020 CONFIG_RTC_DS1339 - use Maxim, Inc. DS1339 RTC 1021 CONFIG_RTC_DS164x - use Dallas DS164x RTC 1022 CONFIG_RTC_ISL1208 - use Intersil ISL1208 RTC 1023 CONFIG_RTC_MAX6900 - use Maxim, Inc. MAX6900 RTC 1024 CONFIG_SYS_RTC_DS1337_NOOSC - Turn off the OSC output for DS1337 1025 CONFIG_SYS_RV3029_TCR - enable trickle charger on 1026 RV3029 RTC. 1027 1028 Note that if the RTC uses I2C, then the I2C interface 1029 must also be configured. See I2C Support, below. 1030 1031- GPIO Support: 1032 CONFIG_PCA953X - use NXP's PCA953X series I2C GPIO 1033 1034 The CONFIG_SYS_I2C_PCA953X_WIDTH option specifies a list of 1035 chip-ngpio pairs that tell the PCA953X driver the number of 1036 pins supported by a particular chip. 1037 1038 Note that if the GPIO device uses I2C, then the I2C interface 1039 must also be configured. See I2C Support, below. 1040 1041- I/O tracing: 1042 When CONFIG_IO_TRACE is selected, U-Boot intercepts all I/O 1043 accesses and can checksum them or write a list of them out 1044 to memory. See the 'iotrace' command for details. This is 1045 useful for testing device drivers since it can confirm that 1046 the driver behaves the same way before and after a code 1047 change. Currently this is supported on sandbox and arm. To 1048 add support for your architecture, add '#include <iotrace.h>' 1049 to the bottom of arch/<arch>/include/asm/io.h and test. 1050 1051 Example output from the 'iotrace stats' command is below. 1052 Note that if the trace buffer is exhausted, the checksum will 1053 still continue to operate. 1054 1055 iotrace is enabled 1056 Start: 10000000 (buffer start address) 1057 Size: 00010000 (buffer size) 1058 Offset: 00000120 (current buffer offset) 1059 Output: 10000120 (start + offset) 1060 Count: 00000018 (number of trace records) 1061 CRC32: 9526fb66 (CRC32 of all trace records) 1062 1063- Timestamp Support: 1064 1065 When CONFIG_TIMESTAMP is selected, the timestamp 1066 (date and time) of an image is printed by image 1067 commands like bootm or iminfo. This option is 1068 automatically enabled when you select CONFIG_CMD_DATE . 1069 1070- Partition Labels (disklabels) Supported: 1071 Zero or more of the following: 1072 CONFIG_MAC_PARTITION Apple's MacOS partition table. 1073 CONFIG_DOS_PARTITION MS Dos partition table, traditional on the 1074 Intel architecture, USB sticks, etc. 1075 CONFIG_ISO_PARTITION ISO partition table, used on CDROM etc. 1076 CONFIG_EFI_PARTITION GPT partition table, common when EFI is the 1077 bootloader. Note 2TB partition limit; see 1078 disk/part_efi.c 1079 CONFIG_MTD_PARTITIONS Memory Technology Device partition table. 1080 1081 If IDE or SCSI support is enabled (CONFIG_IDE or 1082 CONFIG_SCSI) you must configure support for at 1083 least one non-MTD partition type as well. 1084 1085- IDE Reset method: 1086 CONFIG_IDE_RESET_ROUTINE - this is defined in several 1087 board configurations files but used nowhere! 1088 1089 CONFIG_IDE_RESET - is this is defined, IDE Reset will 1090 be performed by calling the function 1091 ide_set_reset(int reset) 1092 which has to be defined in a board specific file 1093 1094- ATAPI Support: 1095 CONFIG_ATAPI 1096 1097 Set this to enable ATAPI support. 1098 1099- LBA48 Support 1100 CONFIG_LBA48 1101 1102 Set this to enable support for disks larger than 137GB 1103 Also look at CONFIG_SYS_64BIT_LBA. 1104 Whithout these , LBA48 support uses 32bit variables and will 'only' 1105 support disks up to 2.1TB. 1106 1107 CONFIG_SYS_64BIT_LBA: 1108 When enabled, makes the IDE subsystem use 64bit sector addresses. 1109 Default is 32bit. 1110 1111- SCSI Support: 1112 At the moment only there is only support for the 1113 SYM53C8XX SCSI controller; define 1114 CONFIG_SCSI_SYM53C8XX to enable it. 1115 1116 CONFIG_SYS_SCSI_MAX_LUN [8], CONFIG_SYS_SCSI_MAX_SCSI_ID [7] and 1117 CONFIG_SYS_SCSI_MAX_DEVICE [CONFIG_SYS_SCSI_MAX_SCSI_ID * 1118 CONFIG_SYS_SCSI_MAX_LUN] can be adjusted to define the 1119 maximum numbers of LUNs, SCSI ID's and target 1120 devices. 1121 CONFIG_SYS_SCSI_SYM53C8XX_CCF to fix clock timing (80Mhz) 1122 1123 The environment variable 'scsidevs' is set to the number of 1124 SCSI devices found during the last scan. 1125 1126- NETWORK Support (PCI): 1127 CONFIG_E1000 1128 Support for Intel 8254x/8257x gigabit chips. 1129 1130 CONFIG_E1000_SPI 1131 Utility code for direct access to the SPI bus on Intel 8257x. 1132 This does not do anything useful unless you set at least one 1133 of CONFIG_CMD_E1000 or CONFIG_E1000_SPI_GENERIC. 1134 1135 CONFIG_E1000_SPI_GENERIC 1136 Allow generic access to the SPI bus on the Intel 8257x, for 1137 example with the "sspi" command. 1138 1139 CONFIG_CMD_E1000 1140 Management command for E1000 devices. When used on devices 1141 with SPI support you can reprogram the EEPROM from U-Boot. 1142 1143 CONFIG_EEPRO100 1144 Support for Intel 82557/82559/82559ER chips. 1145 Optional CONFIG_EEPRO100_SROM_WRITE enables EEPROM 1146 write routine for first time initialisation. 1147 1148 CONFIG_TULIP 1149 Support for Digital 2114x chips. 1150 Optional CONFIG_TULIP_SELECT_MEDIA for board specific 1151 modem chip initialisation (KS8761/QS6611). 1152 1153 CONFIG_NATSEMI 1154 Support for National dp83815 chips. 1155 1156 CONFIG_NS8382X 1157 Support for National dp8382[01] gigabit chips. 1158 1159- NETWORK Support (other): 1160 1161 CONFIG_DRIVER_AT91EMAC 1162 Support for AT91RM9200 EMAC. 1163 1164 CONFIG_RMII 1165 Define this to use reduced MII inteface 1166 1167 CONFIG_DRIVER_AT91EMAC_QUIET 1168 If this defined, the driver is quiet. 1169 The driver doen't show link status messages. 1170 1171 CONFIG_CALXEDA_XGMAC 1172 Support for the Calxeda XGMAC device 1173 1174 CONFIG_LAN91C96 1175 Support for SMSC's LAN91C96 chips. 1176 1177 CONFIG_LAN91C96_USE_32_BIT 1178 Define this to enable 32 bit addressing 1179 1180 CONFIG_SMC91111 1181 Support for SMSC's LAN91C111 chip 1182 1183 CONFIG_SMC91111_BASE 1184 Define this to hold the physical address 1185 of the device (I/O space) 1186 1187 CONFIG_SMC_USE_32_BIT 1188 Define this if data bus is 32 bits 1189 1190 CONFIG_SMC_USE_IOFUNCS 1191 Define this to use i/o functions instead of macros 1192 (some hardware wont work with macros) 1193 1194 CONFIG_DRIVER_TI_EMAC 1195 Support for davinci emac 1196 1197 CONFIG_SYS_DAVINCI_EMAC_PHY_COUNT 1198 Define this if you have more then 3 PHYs. 1199 1200 CONFIG_FTGMAC100 1201 Support for Faraday's FTGMAC100 Gigabit SoC Ethernet 1202 1203 CONFIG_FTGMAC100_EGIGA 1204 Define this to use GE link update with gigabit PHY. 1205 Define this if FTGMAC100 is connected to gigabit PHY. 1206 If your system has 10/100 PHY only, it might not occur 1207 wrong behavior. Because PHY usually return timeout or 1208 useless data when polling gigabit status and gigabit 1209 control registers. This behavior won't affect the 1210 correctnessof 10/100 link speed update. 1211 1212 CONFIG_SMC911X 1213 Support for SMSC's LAN911x and LAN921x chips 1214 1215 CONFIG_SMC911X_BASE 1216 Define this to hold the physical address 1217 of the device (I/O space) 1218 1219 CONFIG_SMC911X_32_BIT 1220 Define this if data bus is 32 bits 1221 1222 CONFIG_SMC911X_16_BIT 1223 Define this if data bus is 16 bits. If your processor 1224 automatically converts one 32 bit word to two 16 bit 1225 words you may also try CONFIG_SMC911X_32_BIT. 1226 1227 CONFIG_SH_ETHER 1228 Support for Renesas on-chip Ethernet controller 1229 1230 CONFIG_SH_ETHER_USE_PORT 1231 Define the number of ports to be used 1232 1233 CONFIG_SH_ETHER_PHY_ADDR 1234 Define the ETH PHY's address 1235 1236 CONFIG_SH_ETHER_CACHE_WRITEBACK 1237 If this option is set, the driver enables cache flush. 1238 1239- PWM Support: 1240 CONFIG_PWM_IMX 1241 Support for PWM module on the imx6. 1242 1243- TPM Support: 1244 CONFIG_TPM 1245 Support TPM devices. 1246 1247 CONFIG_TPM_TIS_INFINEON 1248 Support for Infineon i2c bus TPM devices. Only one device 1249 per system is supported at this time. 1250 1251 CONFIG_TPM_TIS_I2C_BURST_LIMITATION 1252 Define the burst count bytes upper limit 1253 1254 CONFIG_TPM_ST33ZP24 1255 Support for STMicroelectronics TPM devices. Requires DM_TPM support. 1256 1257 CONFIG_TPM_ST33ZP24_I2C 1258 Support for STMicroelectronics ST33ZP24 I2C devices. 1259 Requires TPM_ST33ZP24 and I2C. 1260 1261 CONFIG_TPM_ST33ZP24_SPI 1262 Support for STMicroelectronics ST33ZP24 SPI devices. 1263 Requires TPM_ST33ZP24 and SPI. 1264 1265 CONFIG_TPM_ATMEL_TWI 1266 Support for Atmel TWI TPM device. Requires I2C support. 1267 1268 CONFIG_TPM_TIS_LPC 1269 Support for generic parallel port TPM devices. Only one device 1270 per system is supported at this time. 1271 1272 CONFIG_TPM_TIS_BASE_ADDRESS 1273 Base address where the generic TPM device is mapped 1274 to. Contemporary x86 systems usually map it at 1275 0xfed40000. 1276 1277 CONFIG_CMD_TPM 1278 Add tpm monitor functions. 1279 Requires CONFIG_TPM. If CONFIG_TPM_AUTH_SESSIONS is set, also 1280 provides monitor access to authorized functions. 1281 1282 CONFIG_TPM 1283 Define this to enable the TPM support library which provides 1284 functional interfaces to some TPM commands. 1285 Requires support for a TPM device. 1286 1287 CONFIG_TPM_AUTH_SESSIONS 1288 Define this to enable authorized functions in the TPM library. 1289 Requires CONFIG_TPM and CONFIG_SHA1. 1290 1291- USB Support: 1292 At the moment only the UHCI host controller is 1293 supported (PIP405, MIP405, MPC5200); define 1294 CONFIG_USB_UHCI to enable it. 1295 define CONFIG_USB_KEYBOARD to enable the USB Keyboard 1296 and define CONFIG_USB_STORAGE to enable the USB 1297 storage devices. 1298 Note: 1299 Supported are USB Keyboards and USB Floppy drives 1300 (TEAC FD-05PUB). 1301 MPC5200 USB requires additional defines: 1302 CONFIG_USB_CLOCK 1303 for 528 MHz Clock: 0x0001bbbb 1304 CONFIG_PSC3_USB 1305 for USB on PSC3 1306 CONFIG_USB_CONFIG 1307 for differential drivers: 0x00001000 1308 for single ended drivers: 0x00005000 1309 for differential drivers on PSC3: 0x00000100 1310 for single ended drivers on PSC3: 0x00004100 1311 CONFIG_SYS_USB_EVENT_POLL 1312 May be defined to allow interrupt polling 1313 instead of using asynchronous interrupts 1314 1315 CONFIG_USB_EHCI_TXFIFO_THRESH enables setting of the 1316 txfilltuning field in the EHCI controller on reset. 1317 1318 CONFIG_USB_DWC2_REG_ADDR the physical CPU address of the DWC2 1319 HW module registers. 1320 1321- USB Device: 1322 Define the below if you wish to use the USB console. 1323 Once firmware is rebuilt from a serial console issue the 1324 command "setenv stdin usbtty; setenv stdout usbtty" and 1325 attach your USB cable. The Unix command "dmesg" should print 1326 it has found a new device. The environment variable usbtty 1327 can be set to gserial or cdc_acm to enable your device to 1328 appear to a USB host as a Linux gserial device or a 1329 Common Device Class Abstract Control Model serial device. 1330 If you select usbtty = gserial you should be able to enumerate 1331 a Linux host by 1332 # modprobe usbserial vendor=0xVendorID product=0xProductID 1333 else if using cdc_acm, simply setting the environment 1334 variable usbtty to be cdc_acm should suffice. The following 1335 might be defined in YourBoardName.h 1336 1337 CONFIG_USB_DEVICE 1338 Define this to build a UDC device 1339 1340 CONFIG_USB_TTY 1341 Define this to have a tty type of device available to 1342 talk to the UDC device 1343 1344 CONFIG_USBD_HS 1345 Define this to enable the high speed support for usb 1346 device and usbtty. If this feature is enabled, a routine 1347 int is_usbd_high_speed(void) 1348 also needs to be defined by the driver to dynamically poll 1349 whether the enumeration has succeded at high speed or full 1350 speed. 1351 1352 CONFIG_SYS_CONSOLE_IS_IN_ENV 1353 Define this if you want stdin, stdout &/or stderr to 1354 be set to usbtty. 1355 1356 mpc8xx: 1357 CONFIG_SYS_USB_EXTC_CLK 0xBLAH 1358 Derive USB clock from external clock "blah" 1359 - CONFIG_SYS_USB_EXTC_CLK 0x02 1360 1361 If you have a USB-IF assigned VendorID then you may wish to 1362 define your own vendor specific values either in BoardName.h 1363 or directly in usbd_vendor_info.h. If you don't define 1364 CONFIG_USBD_MANUFACTURER, CONFIG_USBD_PRODUCT_NAME, 1365 CONFIG_USBD_VENDORID and CONFIG_USBD_PRODUCTID, then U-Boot 1366 should pretend to be a Linux device to it's target host. 1367 1368 CONFIG_USBD_MANUFACTURER 1369 Define this string as the name of your company for 1370 - CONFIG_USBD_MANUFACTURER "my company" 1371 1372 CONFIG_USBD_PRODUCT_NAME 1373 Define this string as the name of your product 1374 - CONFIG_USBD_PRODUCT_NAME "acme usb device" 1375 1376 CONFIG_USBD_VENDORID 1377 Define this as your assigned Vendor ID from the USB 1378 Implementors Forum. This *must* be a genuine Vendor ID 1379 to avoid polluting the USB namespace. 1380 - CONFIG_USBD_VENDORID 0xFFFF 1381 1382 CONFIG_USBD_PRODUCTID 1383 Define this as the unique Product ID 1384 for your device 1385 - CONFIG_USBD_PRODUCTID 0xFFFF 1386 1387- ULPI Layer Support: 1388 The ULPI (UTMI Low Pin (count) Interface) PHYs are supported via 1389 the generic ULPI layer. The generic layer accesses the ULPI PHY 1390 via the platform viewport, so you need both the genric layer and 1391 the viewport enabled. Currently only Chipidea/ARC based 1392 viewport is supported. 1393 To enable the ULPI layer support, define CONFIG_USB_ULPI and 1394 CONFIG_USB_ULPI_VIEWPORT in your board configuration file. 1395 If your ULPI phy needs a different reference clock than the 1396 standard 24 MHz then you have to define CONFIG_ULPI_REF_CLK to 1397 the appropriate value in Hz. 1398 1399- MMC Support: 1400 The MMC controller on the Intel PXA is supported. To 1401 enable this define CONFIG_MMC. The MMC can be 1402 accessed from the boot prompt by mapping the device 1403 to physical memory similar to flash. Command line is 1404 enabled with CONFIG_CMD_MMC. The MMC driver also works with 1405 the FAT fs. This is enabled with CONFIG_CMD_FAT. 1406 1407 CONFIG_SH_MMCIF 1408 Support for Renesas on-chip MMCIF controller 1409 1410 CONFIG_SH_MMCIF_ADDR 1411 Define the base address of MMCIF registers 1412 1413 CONFIG_SH_MMCIF_CLK 1414 Define the clock frequency for MMCIF 1415 1416 CONFIG_SUPPORT_EMMC_BOOT 1417 Enable some additional features of the eMMC boot partitions. 1418 1419 CONFIG_SUPPORT_EMMC_RPMB 1420 Enable the commands for reading, writing and programming the 1421 key for the Replay Protection Memory Block partition in eMMC. 1422 1423- USB Device Firmware Update (DFU) class support: 1424 CONFIG_USB_FUNCTION_DFU 1425 This enables the USB portion of the DFU USB class 1426 1427 CONFIG_CMD_DFU 1428 This enables the command "dfu" which is used to have 1429 U-Boot create a DFU class device via USB. This command 1430 requires that the "dfu_alt_info" environment variable be 1431 set and define the alt settings to expose to the host. 1432 1433 CONFIG_DFU_MMC 1434 This enables support for exposing (e)MMC devices via DFU. 1435 1436 CONFIG_DFU_NAND 1437 This enables support for exposing NAND devices via DFU. 1438 1439 CONFIG_DFU_RAM 1440 This enables support for exposing RAM via DFU. 1441 Note: DFU spec refer to non-volatile memory usage, but 1442 allow usages beyond the scope of spec - here RAM usage, 1443 one that would help mostly the developer. 1444 1445 CONFIG_SYS_DFU_DATA_BUF_SIZE 1446 Dfu transfer uses a buffer before writing data to the 1447 raw storage device. Make the size (in bytes) of this buffer 1448 configurable. The size of this buffer is also configurable 1449 through the "dfu_bufsiz" environment variable. 1450 1451 CONFIG_SYS_DFU_MAX_FILE_SIZE 1452 When updating files rather than the raw storage device, 1453 we use a static buffer to copy the file into and then write 1454 the buffer once we've been given the whole file. Define 1455 this to the maximum filesize (in bytes) for the buffer. 1456 Default is 4 MiB if undefined. 1457 1458 DFU_DEFAULT_POLL_TIMEOUT 1459 Poll timeout [ms], is the timeout a device can send to the 1460 host. The host must wait for this timeout before sending 1461 a subsequent DFU_GET_STATUS request to the device. 1462 1463 DFU_MANIFEST_POLL_TIMEOUT 1464 Poll timeout [ms], which the device sends to the host when 1465 entering dfuMANIFEST state. Host waits this timeout, before 1466 sending again an USB request to the device. 1467 1468- USB Device Android Fastboot support: 1469 CONFIG_USB_FUNCTION_FASTBOOT 1470 This enables the USB part of the fastboot gadget 1471 1472 CONFIG_CMD_FASTBOOT 1473 This enables the command "fastboot" which enables the Android 1474 fastboot mode for the platform's USB device. Fastboot is a USB 1475 protocol for downloading images, flashing and device control 1476 used on Android devices. 1477 See doc/README.android-fastboot for more information. 1478 1479 CONFIG_ANDROID_BOOT_IMAGE 1480 This enables support for booting images which use the Android 1481 image format header. 1482 1483 CONFIG_FASTBOOT_BUF_ADDR 1484 The fastboot protocol requires a large memory buffer for 1485 downloads. Define this to the starting RAM address to use for 1486 downloaded images. 1487 1488 CONFIG_FASTBOOT_BUF_SIZE 1489 The fastboot protocol requires a large memory buffer for 1490 downloads. This buffer should be as large as possible for a 1491 platform. Define this to the size available RAM for fastboot. 1492 1493 CONFIG_FASTBOOT_FLASH 1494 The fastboot protocol includes a "flash" command for writing 1495 the downloaded image to a non-volatile storage device. Define 1496 this to enable the "fastboot flash" command. 1497 1498 CONFIG_FASTBOOT_FLASH_MMC_DEV 1499 The fastboot "flash" command requires additional information 1500 regarding the non-volatile storage device. Define this to 1501 the eMMC device that fastboot should use to store the image. 1502 1503 CONFIG_FASTBOOT_GPT_NAME 1504 The fastboot "flash" command supports writing the downloaded 1505 image to the Protective MBR and the Primary GUID Partition 1506 Table. (Additionally, this downloaded image is post-processed 1507 to generate and write the Backup GUID Partition Table.) 1508 This occurs when the specified "partition name" on the 1509 "fastboot flash" command line matches this value. 1510 The default is "gpt" if undefined. 1511 1512 CONFIG_FASTBOOT_MBR_NAME 1513 The fastboot "flash" command supports writing the downloaded 1514 image to DOS MBR. 1515 This occurs when the "partition name" specified on the 1516 "fastboot flash" command line matches this value. 1517 If not defined the default value "mbr" is used. 1518 1519- Journaling Flash filesystem support: 1520 CONFIG_JFFS2_NAND 1521 Define these for a default partition on a NAND device 1522 1523 CONFIG_SYS_JFFS2_FIRST_SECTOR, 1524 CONFIG_SYS_JFFS2_FIRST_BANK, CONFIG_SYS_JFFS2_NUM_BANKS 1525 Define these for a default partition on a NOR device 1526 1527- FAT(File Allocation Table) filesystem write function support: 1528 CONFIG_FAT_WRITE 1529 1530 Define this to enable support for saving memory data as a 1531 file in FAT formatted partition. 1532 1533 This will also enable the command "fatwrite" enabling the 1534 user to write files to FAT. 1535 1536- FAT(File Allocation Table) filesystem cluster size: 1537 CONFIG_FS_FAT_MAX_CLUSTSIZE 1538 1539 Define the max cluster size for fat operations else 1540 a default value of 65536 will be defined. 1541 1542- Keyboard Support: 1543 See Kconfig help for available keyboard drivers. 1544 1545 CONFIG_KEYBOARD 1546 1547 Define this to enable a custom keyboard support. 1548 This simply calls drv_keyboard_init() which must be 1549 defined in your board-specific files. This option is deprecated 1550 and is only used by novena. For new boards, use driver model 1551 instead. 1552 1553- Video support: 1554 CONFIG_FSL_DIU_FB 1555 Enable the Freescale DIU video driver. Reference boards for 1556 SOCs that have a DIU should define this macro to enable DIU 1557 support, and should also define these other macros: 1558 1559 CONFIG_SYS_DIU_ADDR 1560 CONFIG_VIDEO 1561 CONFIG_CFB_CONSOLE 1562 CONFIG_VIDEO_SW_CURSOR 1563 CONFIG_VGA_AS_SINGLE_DEVICE 1564 CONFIG_VIDEO_LOGO 1565 CONFIG_VIDEO_BMP_LOGO 1566 1567 The DIU driver will look for the 'video-mode' environment 1568 variable, and if defined, enable the DIU as a console during 1569 boot. See the documentation file doc/README.video for a 1570 description of this variable. 1571 1572- LCD Support: CONFIG_LCD 1573 1574 Define this to enable LCD support (for output to LCD 1575 display); also select one of the supported displays 1576 by defining one of these: 1577 1578 CONFIG_ATMEL_LCD: 1579 1580 HITACHI TX09D70VM1CCA, 3.5", 240x320. 1581 1582 CONFIG_NEC_NL6448AC33: 1583 1584 NEC NL6448AC33-18. Active, color, single scan. 1585 1586 CONFIG_NEC_NL6448BC20 1587 1588 NEC NL6448BC20-08. 6.5", 640x480. 1589 Active, color, single scan. 1590 1591 CONFIG_NEC_NL6448BC33_54 1592 1593 NEC NL6448BC33-54. 10.4", 640x480. 1594 Active, color, single scan. 1595 1596 CONFIG_SHARP_16x9 1597 1598 Sharp 320x240. Active, color, single scan. 1599 It isn't 16x9, and I am not sure what it is. 1600 1601 CONFIG_SHARP_LQ64D341 1602 1603 Sharp LQ64D341 display, 640x480. 1604 Active, color, single scan. 1605 1606 CONFIG_HLD1045 1607 1608 HLD1045 display, 640x480. 1609 Active, color, single scan. 1610 1611 CONFIG_OPTREX_BW 1612 1613 Optrex CBL50840-2 NF-FW 99 22 M5 1614 or 1615 Hitachi LMG6912RPFC-00T 1616 or 1617 Hitachi SP14Q002 1618 1619 320x240. Black & white. 1620 1621 CONFIG_LCD_ALIGNMENT 1622 1623 Normally the LCD is page-aligned (typically 4KB). If this is 1624 defined then the LCD will be aligned to this value instead. 1625 For ARM it is sometimes useful to use MMU_SECTION_SIZE 1626 here, since it is cheaper to change data cache settings on 1627 a per-section basis. 1628 1629 1630 CONFIG_LCD_ROTATION 1631 1632 Sometimes, for example if the display is mounted in portrait 1633 mode or even if it's mounted landscape but rotated by 180degree, 1634 we need to rotate our content of the display relative to the 1635 framebuffer, so that user can read the messages which are 1636 printed out. 1637 Once CONFIG_LCD_ROTATION is defined, the lcd_console will be 1638 initialized with a given rotation from "vl_rot" out of 1639 "vidinfo_t" which is provided by the board specific code. 1640 The value for vl_rot is coded as following (matching to 1641 fbcon=rotate:<n> linux-kernel commandline): 1642 0 = no rotation respectively 0 degree 1643 1 = 90 degree rotation 1644 2 = 180 degree rotation 1645 3 = 270 degree rotation 1646 1647 If CONFIG_LCD_ROTATION is not defined, the console will be 1648 initialized with 0degree rotation. 1649 1650 CONFIG_LCD_BMP_RLE8 1651 1652 Support drawing of RLE8-compressed bitmaps on the LCD. 1653 1654 CONFIG_I2C_EDID 1655 1656 Enables an 'i2c edid' command which can read EDID 1657 information over I2C from an attached LCD display. 1658 1659- Splash Screen Support: CONFIG_SPLASH_SCREEN 1660 1661 If this option is set, the environment is checked for 1662 a variable "splashimage". If found, the usual display 1663 of logo, copyright and system information on the LCD 1664 is suppressed and the BMP image at the address 1665 specified in "splashimage" is loaded instead. The 1666 console is redirected to the "nulldev", too. This 1667 allows for a "silent" boot where a splash screen is 1668 loaded very quickly after power-on. 1669 1670 CONFIG_SPLASHIMAGE_GUARD 1671 1672 If this option is set, then U-Boot will prevent the environment 1673 variable "splashimage" from being set to a problematic address 1674 (see doc/README.displaying-bmps). 1675 This option is useful for targets where, due to alignment 1676 restrictions, an improperly aligned BMP image will cause a data 1677 abort. If you think you will not have problems with unaligned 1678 accesses (for example because your toolchain prevents them) 1679 there is no need to set this option. 1680 1681 CONFIG_SPLASH_SCREEN_ALIGN 1682 1683 If this option is set the splash image can be freely positioned 1684 on the screen. Environment variable "splashpos" specifies the 1685 position as "x,y". If a positive number is given it is used as 1686 number of pixel from left/top. If a negative number is given it 1687 is used as number of pixel from right/bottom. You can also 1688 specify 'm' for centering the image. 1689 1690 Example: 1691 setenv splashpos m,m 1692 => image at center of screen 1693 1694 setenv splashpos 30,20 1695 => image at x = 30 and y = 20 1696 1697 setenv splashpos -10,m 1698 => vertically centered image 1699 at x = dspWidth - bmpWidth - 9 1700 1701- Gzip compressed BMP image support: CONFIG_VIDEO_BMP_GZIP 1702 1703 If this option is set, additionally to standard BMP 1704 images, gzipped BMP images can be displayed via the 1705 splashscreen support or the bmp command. 1706 1707- Run length encoded BMP image (RLE8) support: CONFIG_VIDEO_BMP_RLE8 1708 1709 If this option is set, 8-bit RLE compressed BMP images 1710 can be displayed via the splashscreen support or the 1711 bmp command. 1712 1713- Compression support: 1714 CONFIG_GZIP 1715 1716 Enabled by default to support gzip compressed images. 1717 1718 CONFIG_BZIP2 1719 1720 If this option is set, support for bzip2 compressed 1721 images is included. If not, only uncompressed and gzip 1722 compressed images are supported. 1723 1724 NOTE: the bzip2 algorithm requires a lot of RAM, so 1725 the malloc area (as defined by CONFIG_SYS_MALLOC_LEN) should 1726 be at least 4MB. 1727 1728 CONFIG_LZMA 1729 1730 If this option is set, support for lzma compressed 1731 images is included. 1732 1733 Note: The LZMA algorithm adds between 2 and 4KB of code and it 1734 requires an amount of dynamic memory that is given by the 1735 formula: 1736 1737 (1846 + 768 << (lc + lp)) * sizeof(uint16) 1738 1739 Where lc and lp stand for, respectively, Literal context bits 1740 and Literal pos bits. 1741 1742 This value is upper-bounded by 14MB in the worst case. Anyway, 1743 for a ~4MB large kernel image, we have lc=3 and lp=0 for a 1744 total amount of (1846 + 768 << (3 + 0)) * 2 = ~41KB... that is 1745 a very small buffer. 1746 1747 Use the lzmainfo tool to determinate the lc and lp values and 1748 then calculate the amount of needed dynamic memory (ensuring 1749 the appropriate CONFIG_SYS_MALLOC_LEN value). 1750 1751 CONFIG_LZO 1752 1753 If this option is set, support for LZO compressed images 1754 is included. 1755 1756- MII/PHY support: 1757 CONFIG_PHY_ADDR 1758 1759 The address of PHY on MII bus. 1760 1761 CONFIG_PHY_CLOCK_FREQ (ppc4xx) 1762 1763 The clock frequency of the MII bus 1764 1765 CONFIG_PHY_GIGE 1766 1767 If this option is set, support for speed/duplex 1768 detection of gigabit PHY is included. 1769 1770 CONFIG_PHY_RESET_DELAY 1771 1772 Some PHY like Intel LXT971A need extra delay after 1773 reset before any MII register access is possible. 1774 For such PHY, set this option to the usec delay 1775 required. (minimum 300usec for LXT971A) 1776 1777 CONFIG_PHY_CMD_DELAY (ppc4xx) 1778 1779 Some PHY like Intel LXT971A need extra delay after 1780 command issued before MII status register can be read 1781 1782- IP address: 1783 CONFIG_IPADDR 1784 1785 Define a default value for the IP address to use for 1786 the default Ethernet interface, in case this is not 1787 determined through e.g. bootp. 1788 (Environment variable "ipaddr") 1789 1790- Server IP address: 1791 CONFIG_SERVERIP 1792 1793 Defines a default value for the IP address of a TFTP 1794 server to contact when using the "tftboot" command. 1795 (Environment variable "serverip") 1796 1797 CONFIG_KEEP_SERVERADDR 1798 1799 Keeps the server's MAC address, in the env 'serveraddr' 1800 for passing to bootargs (like Linux's netconsole option) 1801 1802- Gateway IP address: 1803 CONFIG_GATEWAYIP 1804 1805 Defines a default value for the IP address of the 1806 default router where packets to other networks are 1807 sent to. 1808 (Environment variable "gatewayip") 1809 1810- Subnet mask: 1811 CONFIG_NETMASK 1812 1813 Defines a default value for the subnet mask (or 1814 routing prefix) which is used to determine if an IP 1815 address belongs to the local subnet or needs to be 1816 forwarded through a router. 1817 (Environment variable "netmask") 1818 1819- Multicast TFTP Mode: 1820 CONFIG_MCAST_TFTP 1821 1822 Defines whether you want to support multicast TFTP as per 1823 rfc-2090; for example to work with atftp. Lets lots of targets 1824 tftp down the same boot image concurrently. Note: the Ethernet 1825 driver in use must provide a function: mcast() to join/leave a 1826 multicast group. 1827 1828- BOOTP Recovery Mode: 1829 CONFIG_BOOTP_RANDOM_DELAY 1830 1831 If you have many targets in a network that try to 1832 boot using BOOTP, you may want to avoid that all 1833 systems send out BOOTP requests at precisely the same 1834 moment (which would happen for instance at recovery 1835 from a power failure, when all systems will try to 1836 boot, thus flooding the BOOTP server. Defining 1837 CONFIG_BOOTP_RANDOM_DELAY causes a random delay to be 1838 inserted before sending out BOOTP requests. The 1839 following delays are inserted then: 1840 1841 1st BOOTP request: delay 0 ... 1 sec 1842 2nd BOOTP request: delay 0 ... 2 sec 1843 3rd BOOTP request: delay 0 ... 4 sec 1844 4th and following 1845 BOOTP requests: delay 0 ... 8 sec 1846 1847 CONFIG_BOOTP_ID_CACHE_SIZE 1848 1849 BOOTP packets are uniquely identified using a 32-bit ID. The 1850 server will copy the ID from client requests to responses and 1851 U-Boot will use this to determine if it is the destination of 1852 an incoming response. Some servers will check that addresses 1853 aren't in use before handing them out (usually using an ARP 1854 ping) and therefore take up to a few hundred milliseconds to 1855 respond. Network congestion may also influence the time it 1856 takes for a response to make it back to the client. If that 1857 time is too long, U-Boot will retransmit requests. In order 1858 to allow earlier responses to still be accepted after these 1859 retransmissions, U-Boot's BOOTP client keeps a small cache of 1860 IDs. The CONFIG_BOOTP_ID_CACHE_SIZE controls the size of this 1861 cache. The default is to keep IDs for up to four outstanding 1862 requests. Increasing this will allow U-Boot to accept offers 1863 from a BOOTP client in networks with unusually high latency. 1864 1865- DHCP Advanced Options: 1866 You can fine tune the DHCP functionality by defining 1867 CONFIG_BOOTP_* symbols: 1868 1869 CONFIG_BOOTP_SUBNETMASK 1870 CONFIG_BOOTP_GATEWAY 1871 CONFIG_BOOTP_HOSTNAME 1872 CONFIG_BOOTP_NISDOMAIN 1873 CONFIG_BOOTP_BOOTPATH 1874 CONFIG_BOOTP_BOOTFILESIZE 1875 CONFIG_BOOTP_DNS 1876 CONFIG_BOOTP_DNS2 1877 CONFIG_BOOTP_SEND_HOSTNAME 1878 CONFIG_BOOTP_NTPSERVER 1879 CONFIG_BOOTP_TIMEOFFSET 1880 CONFIG_BOOTP_VENDOREX 1881 CONFIG_BOOTP_MAY_FAIL 1882 1883 CONFIG_BOOTP_SERVERIP - TFTP server will be the serverip 1884 environment variable, not the BOOTP server. 1885 1886 CONFIG_BOOTP_MAY_FAIL - If the DHCP server is not found 1887 after the configured retry count, the call will fail 1888 instead of starting over. This can be used to fail over 1889 to Link-local IP address configuration if the DHCP server 1890 is not available. 1891 1892 CONFIG_BOOTP_DNS2 - If a DHCP client requests the DNS 1893 serverip from a DHCP server, it is possible that more 1894 than one DNS serverip is offered to the client. 1895 If CONFIG_BOOTP_DNS2 is enabled, the secondary DNS 1896 serverip will be stored in the additional environment 1897 variable "dnsip2". The first DNS serverip is always 1898 stored in the variable "dnsip", when CONFIG_BOOTP_DNS 1899 is defined. 1900 1901 CONFIG_BOOTP_SEND_HOSTNAME - Some DHCP servers are capable 1902 to do a dynamic update of a DNS server. To do this, they 1903 need the hostname of the DHCP requester. 1904 If CONFIG_BOOTP_SEND_HOSTNAME is defined, the content 1905 of the "hostname" environment variable is passed as 1906 option 12 to the DHCP server. 1907 1908 CONFIG_BOOTP_DHCP_REQUEST_DELAY 1909 1910 A 32bit value in microseconds for a delay between 1911 receiving a "DHCP Offer" and sending the "DHCP Request". 1912 This fixes a problem with certain DHCP servers that don't 1913 respond 100% of the time to a "DHCP request". E.g. On an 1914 AT91RM9200 processor running at 180MHz, this delay needed 1915 to be *at least* 15,000 usec before a Windows Server 2003 1916 DHCP server would reply 100% of the time. I recommend at 1917 least 50,000 usec to be safe. The alternative is to hope 1918 that one of the retries will be successful but note that 1919 the DHCP timeout and retry process takes a longer than 1920 this delay. 1921 1922 - Link-local IP address negotiation: 1923 Negotiate with other link-local clients on the local network 1924 for an address that doesn't require explicit configuration. 1925 This is especially useful if a DHCP server cannot be guaranteed 1926 to exist in all environments that the device must operate. 1927 1928 See doc/README.link-local for more information. 1929 1930 - CDP Options: 1931 CONFIG_CDP_DEVICE_ID 1932 1933 The device id used in CDP trigger frames. 1934 1935 CONFIG_CDP_DEVICE_ID_PREFIX 1936 1937 A two character string which is prefixed to the MAC address 1938 of the device. 1939 1940 CONFIG_CDP_PORT_ID 1941 1942 A printf format string which contains the ascii name of 1943 the port. Normally is set to "eth%d" which sets 1944 eth0 for the first Ethernet, eth1 for the second etc. 1945 1946 CONFIG_CDP_CAPABILITIES 1947 1948 A 32bit integer which indicates the device capabilities; 1949 0x00000010 for a normal host which does not forwards. 1950 1951 CONFIG_CDP_VERSION 1952 1953 An ascii string containing the version of the software. 1954 1955 CONFIG_CDP_PLATFORM 1956 1957 An ascii string containing the name of the platform. 1958 1959 CONFIG_CDP_TRIGGER 1960 1961 A 32bit integer sent on the trigger. 1962 1963 CONFIG_CDP_POWER_CONSUMPTION 1964 1965 A 16bit integer containing the power consumption of the 1966 device in .1 of milliwatts. 1967 1968 CONFIG_CDP_APPLIANCE_VLAN_TYPE 1969 1970 A byte containing the id of the VLAN. 1971 1972- Status LED: CONFIG_LED_STATUS 1973 1974 Several configurations allow to display the current 1975 status using a LED. For instance, the LED will blink 1976 fast while running U-Boot code, stop blinking as 1977 soon as a reply to a BOOTP request was received, and 1978 start blinking slow once the Linux kernel is running 1979 (supported by a status LED driver in the Linux 1980 kernel). Defining CONFIG_LED_STATUS enables this 1981 feature in U-Boot. 1982 1983 Additional options: 1984 1985 CONFIG_LED_STATUS_GPIO 1986 The status LED can be connected to a GPIO pin. 1987 In such cases, the gpio_led driver can be used as a 1988 status LED backend implementation. Define CONFIG_LED_STATUS_GPIO 1989 to include the gpio_led driver in the U-Boot binary. 1990 1991 CONFIG_GPIO_LED_INVERTED_TABLE 1992 Some GPIO connected LEDs may have inverted polarity in which 1993 case the GPIO high value corresponds to LED off state and 1994 GPIO low value corresponds to LED on state. 1995 In such cases CONFIG_GPIO_LED_INVERTED_TABLE may be defined 1996 with a list of GPIO LEDs that have inverted polarity. 1997 1998- CAN Support: CONFIG_CAN_DRIVER 1999 2000 Defining CONFIG_CAN_DRIVER enables CAN driver support 2001 on those systems that support this (optional) 2002 feature, like the TQM8xxL modules. 2003 2004- I2C Support: CONFIG_SYS_I2C 2005 2006 This enable the NEW i2c subsystem, and will allow you to use 2007 i2c commands at the u-boot command line (as long as you set 2008 CONFIG_CMD_I2C in CONFIG_COMMANDS) and communicate with i2c 2009 based realtime clock chips or other i2c devices. See 2010 common/cmd_i2c.c for a description of the command line 2011 interface. 2012 2013 ported i2c driver to the new framework: 2014 - drivers/i2c/soft_i2c.c: 2015 - activate first bus with CONFIG_SYS_I2C_SOFT define 2016 CONFIG_SYS_I2C_SOFT_SPEED and CONFIG_SYS_I2C_SOFT_SLAVE 2017 for defining speed and slave address 2018 - activate second bus with I2C_SOFT_DECLARATIONS2 define 2019 CONFIG_SYS_I2C_SOFT_SPEED_2 and CONFIG_SYS_I2C_SOFT_SLAVE_2 2020 for defining speed and slave address 2021 - activate third bus with I2C_SOFT_DECLARATIONS3 define 2022 CONFIG_SYS_I2C_SOFT_SPEED_3 and CONFIG_SYS_I2C_SOFT_SLAVE_3 2023 for defining speed and slave address 2024 - activate fourth bus with I2C_SOFT_DECLARATIONS4 define 2025 CONFIG_SYS_I2C_SOFT_SPEED_4 and CONFIG_SYS_I2C_SOFT_SLAVE_4 2026 for defining speed and slave address 2027 2028 - drivers/i2c/fsl_i2c.c: 2029 - activate i2c driver with CONFIG_SYS_I2C_FSL 2030 define CONFIG_SYS_FSL_I2C_OFFSET for setting the register 2031 offset CONFIG_SYS_FSL_I2C_SPEED for the i2c speed and 2032 CONFIG_SYS_FSL_I2C_SLAVE for the slave addr of the first 2033 bus. 2034 - If your board supports a second fsl i2c bus, define 2035 CONFIG_SYS_FSL_I2C2_OFFSET for the register offset 2036 CONFIG_SYS_FSL_I2C2_SPEED for the speed and 2037 CONFIG_SYS_FSL_I2C2_SLAVE for the slave address of the 2038 second bus. 2039 2040 - drivers/i2c/tegra_i2c.c: 2041 - activate this driver with CONFIG_SYS_I2C_TEGRA 2042 - This driver adds 4 i2c buses with a fix speed from 2043 100000 and the slave addr 0! 2044 2045 - drivers/i2c/ppc4xx_i2c.c 2046 - activate this driver with CONFIG_SYS_I2C_PPC4XX 2047 - CONFIG_SYS_I2C_PPC4XX_CH0 activate hardware channel 0 2048 - CONFIG_SYS_I2C_PPC4XX_CH1 activate hardware channel 1 2049 2050 - drivers/i2c/i2c_mxc.c 2051 - activate this driver with CONFIG_SYS_I2C_MXC 2052 - enable bus 1 with CONFIG_SYS_I2C_MXC_I2C1 2053 - enable bus 2 with CONFIG_SYS_I2C_MXC_I2C2 2054 - enable bus 3 with CONFIG_SYS_I2C_MXC_I2C3 2055 - enable bus 4 with CONFIG_SYS_I2C_MXC_I2C4 2056 - define speed for bus 1 with CONFIG_SYS_MXC_I2C1_SPEED 2057 - define slave for bus 1 with CONFIG_SYS_MXC_I2C1_SLAVE 2058 - define speed for bus 2 with CONFIG_SYS_MXC_I2C2_SPEED 2059 - define slave for bus 2 with CONFIG_SYS_MXC_I2C2_SLAVE 2060 - define speed for bus 3 with CONFIG_SYS_MXC_I2C3_SPEED 2061 - define slave for bus 3 with CONFIG_SYS_MXC_I2C3_SLAVE 2062 - define speed for bus 4 with CONFIG_SYS_MXC_I2C4_SPEED 2063 - define slave for bus 4 with CONFIG_SYS_MXC_I2C4_SLAVE 2064 If those defines are not set, default value is 100000 2065 for speed, and 0 for slave. 2066 2067 - drivers/i2c/rcar_i2c.c: 2068 - activate this driver with CONFIG_SYS_I2C_RCAR 2069 - This driver adds 4 i2c buses 2070 2071 - CONFIG_SYS_RCAR_I2C0_BASE for setting the register channel 0 2072 - CONFIG_SYS_RCAR_I2C0_SPEED for for the speed channel 0 2073 - CONFIG_SYS_RCAR_I2C1_BASE for setting the register channel 1 2074 - CONFIG_SYS_RCAR_I2C1_SPEED for for the speed channel 1 2075 - CONFIG_SYS_RCAR_I2C2_BASE for setting the register channel 2 2076 - CONFIG_SYS_RCAR_I2C2_SPEED for for the speed channel 2 2077 - CONFIG_SYS_RCAR_I2C3_BASE for setting the register channel 3 2078 - CONFIG_SYS_RCAR_I2C3_SPEED for for the speed channel 3 2079 - CONFIF_SYS_RCAR_I2C_NUM_CONTROLLERS for number of i2c buses 2080 2081 - drivers/i2c/sh_i2c.c: 2082 - activate this driver with CONFIG_SYS_I2C_SH 2083 - This driver adds from 2 to 5 i2c buses 2084 2085 - CONFIG_SYS_I2C_SH_BASE0 for setting the register channel 0 2086 - CONFIG_SYS_I2C_SH_SPEED0 for for the speed channel 0 2087 - CONFIG_SYS_I2C_SH_BASE1 for setting the register channel 1 2088 - CONFIG_SYS_I2C_SH_SPEED1 for for the speed channel 1 2089 - CONFIG_SYS_I2C_SH_BASE2 for setting the register channel 2 2090 - CONFIG_SYS_I2C_SH_SPEED2 for for the speed channel 2 2091 - CONFIG_SYS_I2C_SH_BASE3 for setting the register channel 3 2092 - CONFIG_SYS_I2C_SH_SPEED3 for for the speed channel 3 2093 - CONFIG_SYS_I2C_SH_BASE4 for setting the register channel 4 2094 - CONFIG_SYS_I2C_SH_SPEED4 for for the speed channel 4 2095 - CONFIG_SYS_I2C_SH_NUM_CONTROLLERS for number of i2c buses 2096 2097 - drivers/i2c/omap24xx_i2c.c 2098 - activate this driver with CONFIG_SYS_I2C_OMAP24XX 2099 - CONFIG_SYS_OMAP24_I2C_SPEED speed channel 0 2100 - CONFIG_SYS_OMAP24_I2C_SLAVE slave addr channel 0 2101 - CONFIG_SYS_OMAP24_I2C_SPEED1 speed channel 1 2102 - CONFIG_SYS_OMAP24_I2C_SLAVE1 slave addr channel 1 2103 - CONFIG_SYS_OMAP24_I2C_SPEED2 speed channel 2 2104 - CONFIG_SYS_OMAP24_I2C_SLAVE2 slave addr channel 2 2105 - CONFIG_SYS_OMAP24_I2C_SPEED3 speed channel 3 2106 - CONFIG_SYS_OMAP24_I2C_SLAVE3 slave addr channel 3 2107 - CONFIG_SYS_OMAP24_I2C_SPEED4 speed channel 4 2108 - CONFIG_SYS_OMAP24_I2C_SLAVE4 slave addr channel 4 2109 2110 - drivers/i2c/zynq_i2c.c 2111 - activate this driver with CONFIG_SYS_I2C_ZYNQ 2112 - set CONFIG_SYS_I2C_ZYNQ_SPEED for speed setting 2113 - set CONFIG_SYS_I2C_ZYNQ_SLAVE for slave addr 2114 2115 - drivers/i2c/s3c24x0_i2c.c: 2116 - activate this driver with CONFIG_SYS_I2C_S3C24X0 2117 - This driver adds i2c buses (11 for Exynos5250, Exynos5420 2118 9 i2c buses for Exynos4 and 1 for S3C24X0 SoCs from Samsung) 2119 with a fix speed from 100000 and the slave addr 0! 2120 2121 - drivers/i2c/ihs_i2c.c 2122 - activate this driver with CONFIG_SYS_I2C_IHS 2123 - CONFIG_SYS_I2C_IHS_CH0 activate hardware channel 0 2124 - CONFIG_SYS_I2C_IHS_SPEED_0 speed channel 0 2125 - CONFIG_SYS_I2C_IHS_SLAVE_0 slave addr channel 0 2126 - CONFIG_SYS_I2C_IHS_CH1 activate hardware channel 1 2127 - CONFIG_SYS_I2C_IHS_SPEED_1 speed channel 1 2128 - CONFIG_SYS_I2C_IHS_SLAVE_1 slave addr channel 1 2129 - CONFIG_SYS_I2C_IHS_CH2 activate hardware channel 2 2130 - CONFIG_SYS_I2C_IHS_SPEED_2 speed channel 2 2131 - CONFIG_SYS_I2C_IHS_SLAVE_2 slave addr channel 2 2132 - CONFIG_SYS_I2C_IHS_CH3 activate hardware channel 3 2133 - CONFIG_SYS_I2C_IHS_SPEED_3 speed channel 3 2134 - CONFIG_SYS_I2C_IHS_SLAVE_3 slave addr channel 3 2135 - activate dual channel with CONFIG_SYS_I2C_IHS_DUAL 2136 - CONFIG_SYS_I2C_IHS_SPEED_0_1 speed channel 0_1 2137 - CONFIG_SYS_I2C_IHS_SLAVE_0_1 slave addr channel 0_1 2138 - CONFIG_SYS_I2C_IHS_SPEED_1_1 speed channel 1_1 2139 - CONFIG_SYS_I2C_IHS_SLAVE_1_1 slave addr channel 1_1 2140 - CONFIG_SYS_I2C_IHS_SPEED_2_1 speed channel 2_1 2141 - CONFIG_SYS_I2C_IHS_SLAVE_2_1 slave addr channel 2_1 2142 - CONFIG_SYS_I2C_IHS_SPEED_3_1 speed channel 3_1 2143 - CONFIG_SYS_I2C_IHS_SLAVE_3_1 slave addr channel 3_1 2144 2145 additional defines: 2146 2147 CONFIG_SYS_NUM_I2C_BUSES 2148 Hold the number of i2c buses you want to use. 2149 2150 CONFIG_SYS_I2C_DIRECT_BUS 2151 define this, if you don't use i2c muxes on your hardware. 2152 if CONFIG_SYS_I2C_MAX_HOPS is not defined or == 0 you can 2153 omit this define. 2154 2155 CONFIG_SYS_I2C_MAX_HOPS 2156 define how many muxes are maximal consecutively connected 2157 on one i2c bus. If you not use i2c muxes, omit this 2158 define. 2159 2160 CONFIG_SYS_I2C_BUSES 2161 hold a list of buses you want to use, only used if 2162 CONFIG_SYS_I2C_DIRECT_BUS is not defined, for example 2163 a board with CONFIG_SYS_I2C_MAX_HOPS = 1 and 2164 CONFIG_SYS_NUM_I2C_BUSES = 9: 2165 2166 CONFIG_SYS_I2C_BUSES {{0, {I2C_NULL_HOP}}, \ 2167 {0, {{I2C_MUX_PCA9547, 0x70, 1}}}, \ 2168 {0, {{I2C_MUX_PCA9547, 0x70, 2}}}, \ 2169 {0, {{I2C_MUX_PCA9547, 0x70, 3}}}, \ 2170 {0, {{I2C_MUX_PCA9547, 0x70, 4}}}, \ 2171 {0, {{I2C_MUX_PCA9547, 0x70, 5}}}, \ 2172 {1, {I2C_NULL_HOP}}, \ 2173 {1, {{I2C_MUX_PCA9544, 0x72, 1}}}, \ 2174 {1, {{I2C_MUX_PCA9544, 0x72, 2}}}, \ 2175 } 2176 2177 which defines 2178 bus 0 on adapter 0 without a mux 2179 bus 1 on adapter 0 with a PCA9547 on address 0x70 port 1 2180 bus 2 on adapter 0 with a PCA9547 on address 0x70 port 2 2181 bus 3 on adapter 0 with a PCA9547 on address 0x70 port 3 2182 bus 4 on adapter 0 with a PCA9547 on address 0x70 port 4 2183 bus 5 on adapter 0 with a PCA9547 on address 0x70 port 5 2184 bus 6 on adapter 1 without a mux 2185 bus 7 on adapter 1 with a PCA9544 on address 0x72 port 1 2186 bus 8 on adapter 1 with a PCA9544 on address 0x72 port 2 2187 2188 If you do not have i2c muxes on your board, omit this define. 2189 2190- Legacy I2C Support: 2191 If you use the software i2c interface (CONFIG_SYS_I2C_SOFT) 2192 then the following macros need to be defined (examples are 2193 from include/configs/lwmon.h): 2194 2195 I2C_INIT 2196 2197 (Optional). Any commands necessary to enable the I2C 2198 controller or configure ports. 2199 2200 eg: #define I2C_INIT (immr->im_cpm.cp_pbdir |= PB_SCL) 2201 2202 I2C_PORT 2203 2204 (Only for MPC8260 CPU). The I/O port to use (the code 2205 assumes both bits are on the same port). Valid values 2206 are 0..3 for ports A..D. 2207 2208 I2C_ACTIVE 2209 2210 The code necessary to make the I2C data line active 2211 (driven). If the data line is open collector, this 2212 define can be null. 2213 2214 eg: #define I2C_ACTIVE (immr->im_cpm.cp_pbdir |= PB_SDA) 2215 2216 I2C_TRISTATE 2217 2218 The code necessary to make the I2C data line tri-stated 2219 (inactive). If the data line is open collector, this 2220 define can be null. 2221 2222 eg: #define I2C_TRISTATE (immr->im_cpm.cp_pbdir &= ~PB_SDA) 2223 2224 I2C_READ 2225 2226 Code that returns true if the I2C data line is high, 2227 false if it is low. 2228 2229 eg: #define I2C_READ ((immr->im_cpm.cp_pbdat & PB_SDA) != 0) 2230 2231 I2C_SDA(bit) 2232 2233 If <bit> is true, sets the I2C data line high. If it 2234 is false, it clears it (low). 2235 2236 eg: #define I2C_SDA(bit) \ 2237 if(bit) immr->im_cpm.cp_pbdat |= PB_SDA; \ 2238 else immr->im_cpm.cp_pbdat &= ~PB_SDA 2239 2240 I2C_SCL(bit) 2241 2242 If <bit> is true, sets the I2C clock line high. If it 2243 is false, it clears it (low). 2244 2245 eg: #define I2C_SCL(bit) \ 2246 if(bit) immr->im_cpm.cp_pbdat |= PB_SCL; \ 2247 else immr->im_cpm.cp_pbdat &= ~PB_SCL 2248 2249 I2C_DELAY 2250 2251 This delay is invoked four times per clock cycle so this 2252 controls the rate of data transfer. The data rate thus 2253 is 1 / (I2C_DELAY * 4). Often defined to be something 2254 like: 2255 2256 #define I2C_DELAY udelay(2) 2257 2258 CONFIG_SOFT_I2C_GPIO_SCL / CONFIG_SOFT_I2C_GPIO_SDA 2259 2260 If your arch supports the generic GPIO framework (asm/gpio.h), 2261 then you may alternatively define the two GPIOs that are to be 2262 used as SCL / SDA. Any of the previous I2C_xxx macros will 2263 have GPIO-based defaults assigned to them as appropriate. 2264 2265 You should define these to the GPIO value as given directly to 2266 the generic GPIO functions. 2267 2268 CONFIG_SYS_I2C_INIT_BOARD 2269 2270 When a board is reset during an i2c bus transfer 2271 chips might think that the current transfer is still 2272 in progress. On some boards it is possible to access 2273 the i2c SCLK line directly, either by using the 2274 processor pin as a GPIO or by having a second pin 2275 connected to the bus. If this option is defined a 2276 custom i2c_init_board() routine in boards/xxx/board.c 2277 is run early in the boot sequence. 2278 2279 CONFIG_I2C_MULTI_BUS 2280 2281 This option allows the use of multiple I2C buses, each of which 2282 must have a controller. At any point in time, only one bus is 2283 active. To switch to a different bus, use the 'i2c dev' command. 2284 Note that bus numbering is zero-based. 2285 2286 CONFIG_SYS_I2C_NOPROBES 2287 2288 This option specifies a list of I2C devices that will be skipped 2289 when the 'i2c probe' command is issued. If CONFIG_I2C_MULTI_BUS 2290 is set, specify a list of bus-device pairs. Otherwise, specify 2291 a 1D array of device addresses 2292 2293 e.g. 2294 #undef CONFIG_I2C_MULTI_BUS 2295 #define CONFIG_SYS_I2C_NOPROBES {0x50,0x68} 2296 2297 will skip addresses 0x50 and 0x68 on a board with one I2C bus 2298 2299 #define CONFIG_I2C_MULTI_BUS 2300 #define CONFIG_SYS_I2C_NOPROBES {{0,0x50},{0,0x68},{1,0x54}} 2301 2302 will skip addresses 0x50 and 0x68 on bus 0 and address 0x54 on bus 1 2303 2304 CONFIG_SYS_SPD_BUS_NUM 2305 2306 If defined, then this indicates the I2C bus number for DDR SPD. 2307 If not defined, then U-Boot assumes that SPD is on I2C bus 0. 2308 2309 CONFIG_SYS_RTC_BUS_NUM 2310 2311 If defined, then this indicates the I2C bus number for the RTC. 2312 If not defined, then U-Boot assumes that RTC is on I2C bus 0. 2313 2314 CONFIG_SOFT_I2C_READ_REPEATED_START 2315 2316 defining this will force the i2c_read() function in 2317 the soft_i2c driver to perform an I2C repeated start 2318 between writing the address pointer and reading the 2319 data. If this define is omitted the default behaviour 2320 of doing a stop-start sequence will be used. Most I2C 2321 devices can use either method, but some require one or 2322 the other. 2323 2324- SPI Support: CONFIG_SPI 2325 2326 Enables SPI driver (so far only tested with 2327 SPI EEPROM, also an instance works with Crystal A/D and 2328 D/As on the SACSng board) 2329 2330 CONFIG_SH_SPI 2331 2332 Enables the driver for SPI controller on SuperH. Currently 2333 only SH7757 is supported. 2334 2335 CONFIG_SOFT_SPI 2336 2337 Enables a software (bit-bang) SPI driver rather than 2338 using hardware support. This is a general purpose 2339 driver that only requires three general I/O port pins 2340 (two outputs, one input) to function. If this is 2341 defined, the board configuration must define several 2342 SPI configuration items (port pins to use, etc). For 2343 an example, see include/configs/sacsng.h. 2344 2345 CONFIG_HARD_SPI 2346 2347 Enables a hardware SPI driver for general-purpose reads 2348 and writes. As with CONFIG_SOFT_SPI, the board configuration 2349 must define a list of chip-select function pointers. 2350 Currently supported on some MPC8xxx processors. For an 2351 example, see include/configs/mpc8349emds.h. 2352 2353 CONFIG_MXC_SPI 2354 2355 Enables the driver for the SPI controllers on i.MX and MXC 2356 SoCs. Currently i.MX31/35/51 are supported. 2357 2358 CONFIG_SYS_SPI_MXC_WAIT 2359 Timeout for waiting until spi transfer completed. 2360 default: (CONFIG_SYS_HZ/100) /* 10 ms */ 2361 2362- FPGA Support: CONFIG_FPGA 2363 2364 Enables FPGA subsystem. 2365 2366 CONFIG_FPGA_<vendor> 2367 2368 Enables support for specific chip vendors. 2369 (ALTERA, XILINX) 2370 2371 CONFIG_FPGA_<family> 2372 2373 Enables support for FPGA family. 2374 (SPARTAN2, SPARTAN3, VIRTEX2, CYCLONE2, ACEX1K, ACEX) 2375 2376 CONFIG_FPGA_COUNT 2377 2378 Specify the number of FPGA devices to support. 2379 2380 CONFIG_SYS_FPGA_PROG_FEEDBACK 2381 2382 Enable printing of hash marks during FPGA configuration. 2383 2384 CONFIG_SYS_FPGA_CHECK_BUSY 2385 2386 Enable checks on FPGA configuration interface busy 2387 status by the configuration function. This option 2388 will require a board or device specific function to 2389 be written. 2390 2391 CONFIG_FPGA_DELAY 2392 2393 If defined, a function that provides delays in the FPGA 2394 configuration driver. 2395 2396 CONFIG_SYS_FPGA_CHECK_CTRLC 2397 Allow Control-C to interrupt FPGA configuration 2398 2399 CONFIG_SYS_FPGA_CHECK_ERROR 2400 2401 Check for configuration errors during FPGA bitfile 2402 loading. For example, abort during Virtex II 2403 configuration if the INIT_B line goes low (which 2404 indicated a CRC error). 2405 2406 CONFIG_SYS_FPGA_WAIT_INIT 2407 2408 Maximum time to wait for the INIT_B line to de-assert 2409 after PROB_B has been de-asserted during a Virtex II 2410 FPGA configuration sequence. The default time is 500 2411 ms. 2412 2413 CONFIG_SYS_FPGA_WAIT_BUSY 2414 2415 Maximum time to wait for BUSY to de-assert during 2416 Virtex II FPGA configuration. The default is 5 ms. 2417 2418 CONFIG_SYS_FPGA_WAIT_CONFIG 2419 2420 Time to wait after FPGA configuration. The default is 2421 200 ms. 2422 2423- Configuration Management: 2424 CONFIG_BUILD_TARGET 2425 2426 Some SoCs need special image types (e.g. U-Boot binary 2427 with a special header) as build targets. By defining 2428 CONFIG_BUILD_TARGET in the SoC / board header, this 2429 special image will be automatically built upon calling 2430 make / buildman. 2431 2432 CONFIG_IDENT_STRING 2433 2434 If defined, this string will be added to the U-Boot 2435 version information (U_BOOT_VERSION) 2436 2437- Vendor Parameter Protection: 2438 2439 U-Boot considers the values of the environment 2440 variables "serial#" (Board Serial Number) and 2441 "ethaddr" (Ethernet Address) to be parameters that 2442 are set once by the board vendor / manufacturer, and 2443 protects these variables from casual modification by 2444 the user. Once set, these variables are read-only, 2445 and write or delete attempts are rejected. You can 2446 change this behaviour: 2447 2448 If CONFIG_ENV_OVERWRITE is #defined in your config 2449 file, the write protection for vendor parameters is 2450 completely disabled. Anybody can change or delete 2451 these parameters. 2452 2453 Alternatively, if you define _both_ an ethaddr in the 2454 default env _and_ CONFIG_OVERWRITE_ETHADDR_ONCE, a default 2455 Ethernet address is installed in the environment, 2456 which can be changed exactly ONCE by the user. [The 2457 serial# is unaffected by this, i. e. it remains 2458 read-only.] 2459 2460 The same can be accomplished in a more flexible way 2461 for any variable by configuring the type of access 2462 to allow for those variables in the ".flags" variable 2463 or define CONFIG_ENV_FLAGS_LIST_STATIC. 2464 2465- Protected RAM: 2466 CONFIG_PRAM 2467 2468 Define this variable to enable the reservation of 2469 "protected RAM", i. e. RAM which is not overwritten 2470 by U-Boot. Define CONFIG_PRAM to hold the number of 2471 kB you want to reserve for pRAM. You can overwrite 2472 this default value by defining an environment 2473 variable "pram" to the number of kB you want to 2474 reserve. Note that the board info structure will 2475 still show the full amount of RAM. If pRAM is 2476 reserved, a new environment variable "mem" will 2477 automatically be defined to hold the amount of 2478 remaining RAM in a form that can be passed as boot 2479 argument to Linux, for instance like that: 2480 2481 setenv bootargs ... mem=\${mem} 2482 saveenv 2483 2484 This way you can tell Linux not to use this memory, 2485 either, which results in a memory region that will 2486 not be affected by reboots. 2487 2488 *WARNING* If your board configuration uses automatic 2489 detection of the RAM size, you must make sure that 2490 this memory test is non-destructive. So far, the 2491 following board configurations are known to be 2492 "pRAM-clean": 2493 2494 IVMS8, IVML24, SPD8xx, TQM8xxL, 2495 HERMES, IP860, RPXlite, LWMON, 2496 FLAGADM, TQM8260 2497 2498- Access to physical memory region (> 4GB) 2499 Some basic support is provided for operations on memory not 2500 normally accessible to U-Boot - e.g. some architectures 2501 support access to more than 4GB of memory on 32-bit 2502 machines using physical address extension or similar. 2503 Define CONFIG_PHYSMEM to access this basic support, which 2504 currently only supports clearing the memory. 2505 2506- Error Recovery: 2507 CONFIG_PANIC_HANG 2508 2509 Define this variable to stop the system in case of a 2510 fatal error, so that you have to reset it manually. 2511 This is probably NOT a good idea for an embedded 2512 system where you want the system to reboot 2513 automatically as fast as possible, but it may be 2514 useful during development since you can try to debug 2515 the conditions that lead to the situation. 2516 2517 CONFIG_NET_RETRY_COUNT 2518 2519 This variable defines the number of retries for 2520 network operations like ARP, RARP, TFTP, or BOOTP 2521 before giving up the operation. If not defined, a 2522 default value of 5 is used. 2523 2524 CONFIG_ARP_TIMEOUT 2525 2526 Timeout waiting for an ARP reply in milliseconds. 2527 2528 CONFIG_NFS_TIMEOUT 2529 2530 Timeout in milliseconds used in NFS protocol. 2531 If you encounter "ERROR: Cannot umount" in nfs command, 2532 try longer timeout such as 2533 #define CONFIG_NFS_TIMEOUT 10000UL 2534 2535- Command Interpreter: 2536 CONFIG_AUTO_COMPLETE 2537 2538 Enable auto completion of commands using TAB. 2539 2540 CONFIG_SYS_PROMPT_HUSH_PS2 2541 2542 This defines the secondary prompt string, which is 2543 printed when the command interpreter needs more input 2544 to complete a command. Usually "> ". 2545 2546 Note: 2547 2548 In the current implementation, the local variables 2549 space and global environment variables space are 2550 separated. Local variables are those you define by 2551 simply typing `name=value'. To access a local 2552 variable later on, you have write `$name' or 2553 `${name}'; to execute the contents of a variable 2554 directly type `$name' at the command prompt. 2555 2556 Global environment variables are those you use 2557 setenv/printenv to work with. To run a command stored 2558 in such a variable, you need to use the run command, 2559 and you must not use the '$' sign to access them. 2560 2561 To store commands and special characters in a 2562 variable, please use double quotation marks 2563 surrounding the whole text of the variable, instead 2564 of the backslashes before semicolons and special 2565 symbols. 2566 2567- Command Line Editing and History: 2568 CONFIG_CMDLINE_EDITING 2569 2570 Enable editing and History functions for interactive 2571 command line input operations 2572 2573- Command Line PS1/PS2 support: 2574 CONFIG_CMDLINE_PS_SUPPORT 2575 2576 Enable support for changing the command prompt string 2577 at run-time. Only static string is supported so far. 2578 The string is obtained from environment variables PS1 2579 and PS2. 2580 2581- Default Environment: 2582 CONFIG_EXTRA_ENV_SETTINGS 2583 2584 Define this to contain any number of null terminated 2585 strings (variable = value pairs) that will be part of 2586 the default environment compiled into the boot image. 2587 2588 For example, place something like this in your 2589 board's config file: 2590 2591 #define CONFIG_EXTRA_ENV_SETTINGS \ 2592 "myvar1=value1\0" \ 2593 "myvar2=value2\0" 2594 2595 Warning: This method is based on knowledge about the 2596 internal format how the environment is stored by the 2597 U-Boot code. This is NOT an official, exported 2598 interface! Although it is unlikely that this format 2599 will change soon, there is no guarantee either. 2600 You better know what you are doing here. 2601 2602 Note: overly (ab)use of the default environment is 2603 discouraged. Make sure to check other ways to preset 2604 the environment like the "source" command or the 2605 boot command first. 2606 2607 CONFIG_ENV_VARS_UBOOT_CONFIG 2608 2609 Define this in order to add variables describing the 2610 U-Boot build configuration to the default environment. 2611 These will be named arch, cpu, board, vendor, and soc. 2612 2613 Enabling this option will cause the following to be defined: 2614 2615 - CONFIG_SYS_ARCH 2616 - CONFIG_SYS_CPU 2617 - CONFIG_SYS_BOARD 2618 - CONFIG_SYS_VENDOR 2619 - CONFIG_SYS_SOC 2620 2621 CONFIG_ENV_VARS_UBOOT_RUNTIME_CONFIG 2622 2623 Define this in order to add variables describing certain 2624 run-time determined information about the hardware to the 2625 environment. These will be named board_name, board_rev. 2626 2627 CONFIG_DELAY_ENVIRONMENT 2628 2629 Normally the environment is loaded when the board is 2630 initialised so that it is available to U-Boot. This inhibits 2631 that so that the environment is not available until 2632 explicitly loaded later by U-Boot code. With CONFIG_OF_CONTROL 2633 this is instead controlled by the value of 2634 /config/load-environment. 2635 2636- DataFlash Support: 2637 CONFIG_HAS_DATAFLASH 2638 2639 Defining this option enables DataFlash features and 2640 allows to read/write in Dataflash via the standard 2641 commands cp, md... 2642 2643- Serial Flash support 2644 CONFIG_CMD_SF 2645 2646 Defining this option enables SPI flash commands 2647 'sf probe/read/write/erase/update'. 2648 2649 Usage requires an initial 'probe' to define the serial 2650 flash parameters, followed by read/write/erase/update 2651 commands. 2652 2653 The following defaults may be provided by the platform 2654 to handle the common case when only a single serial 2655 flash is present on the system. 2656 2657 CONFIG_SF_DEFAULT_BUS Bus identifier 2658 CONFIG_SF_DEFAULT_CS Chip-select 2659 CONFIG_SF_DEFAULT_MODE (see include/spi.h) 2660 CONFIG_SF_DEFAULT_SPEED in Hz 2661 2662 CONFIG_CMD_SF_TEST 2663 2664 Define this option to include a destructive SPI flash 2665 test ('sf test'). 2666 2667 CONFIG_SF_DUAL_FLASH Dual flash memories 2668 2669 Define this option to use dual flash support where two flash 2670 memories can be connected with a given cs line. 2671 Currently Xilinx Zynq qspi supports these type of connections. 2672 2673- SystemACE Support: 2674 CONFIG_SYSTEMACE 2675 2676 Adding this option adds support for Xilinx SystemACE 2677 chips attached via some sort of local bus. The address 2678 of the chip must also be defined in the 2679 CONFIG_SYS_SYSTEMACE_BASE macro. For example: 2680 2681 #define CONFIG_SYSTEMACE 2682 #define CONFIG_SYS_SYSTEMACE_BASE 0xf0000000 2683 2684 When SystemACE support is added, the "ace" device type 2685 becomes available to the fat commands, i.e. fatls. 2686 2687- TFTP Fixed UDP Port: 2688 CONFIG_TFTP_PORT 2689 2690 If this is defined, the environment variable tftpsrcp 2691 is used to supply the TFTP UDP source port value. 2692 If tftpsrcp isn't defined, the normal pseudo-random port 2693 number generator is used. 2694 2695 Also, the environment variable tftpdstp is used to supply 2696 the TFTP UDP destination port value. If tftpdstp isn't 2697 defined, the normal port 69 is used. 2698 2699 The purpose for tftpsrcp is to allow a TFTP server to 2700 blindly start the TFTP transfer using the pre-configured 2701 target IP address and UDP port. This has the effect of 2702 "punching through" the (Windows XP) firewall, allowing 2703 the remainder of the TFTP transfer to proceed normally. 2704 A better solution is to properly configure the firewall, 2705 but sometimes that is not allowed. 2706 2707- Hashing support: 2708 CONFIG_HASH_VERIFY 2709 2710 Enable the hash verify command (hash -v). This adds to code 2711 size a little. 2712 2713 Note: There is also a sha1sum command, which should perhaps 2714 be deprecated in favour of 'hash sha1'. 2715 2716- bootcount support: 2717 CONFIG_BOOTCOUNT_LIMIT 2718 2719 This enables the bootcounter support, see: 2720 http://www.denx.de/wiki/DULG/UBootBootCountLimit 2721 2722 CONFIG_AT91SAM9XE 2723 enable special bootcounter support on at91sam9xe based boards. 2724 CONFIG_SOC_DA8XX 2725 enable special bootcounter support on da850 based boards. 2726 CONFIG_BOOTCOUNT_RAM 2727 enable support for the bootcounter in RAM 2728 CONFIG_BOOTCOUNT_I2C 2729 enable support for the bootcounter on an i2c (like RTC) device. 2730 CONFIG_SYS_I2C_RTC_ADDR = i2c chip address 2731 CONFIG_SYS_BOOTCOUNT_ADDR = i2c addr which is used for 2732 the bootcounter. 2733 CONFIG_BOOTCOUNT_ALEN = address len 2734 2735- Show boot progress: 2736 CONFIG_SHOW_BOOT_PROGRESS 2737 2738 Defining this option allows to add some board- 2739 specific code (calling a user-provided function 2740 "show_boot_progress(int)") that enables you to show 2741 the system's boot progress on some display (for 2742 example, some LED's) on your board. At the moment, 2743 the following checkpoints are implemented: 2744 2745 2746Legacy uImage format: 2747 2748 Arg Where When 2749 1 common/cmd_bootm.c before attempting to boot an image 2750 -1 common/cmd_bootm.c Image header has bad magic number 2751 2 common/cmd_bootm.c Image header has correct magic number 2752 -2 common/cmd_bootm.c Image header has bad checksum 2753 3 common/cmd_bootm.c Image header has correct checksum 2754 -3 common/cmd_bootm.c Image data has bad checksum 2755 4 common/cmd_bootm.c Image data has correct checksum 2756 -4 common/cmd_bootm.c Image is for unsupported architecture 2757 5 common/cmd_bootm.c Architecture check OK 2758 -5 common/cmd_bootm.c Wrong Image Type (not kernel, multi) 2759 6 common/cmd_bootm.c Image Type check OK 2760 -6 common/cmd_bootm.c gunzip uncompression error 2761 -7 common/cmd_bootm.c Unimplemented compression type 2762 7 common/cmd_bootm.c Uncompression OK 2763 8 common/cmd_bootm.c No uncompress/copy overwrite error 2764 -9 common/cmd_bootm.c Unsupported OS (not Linux, BSD, VxWorks, QNX) 2765 2766 9 common/image.c Start initial ramdisk verification 2767 -10 common/image.c Ramdisk header has bad magic number 2768 -11 common/image.c Ramdisk header has bad checksum 2769 10 common/image.c Ramdisk header is OK 2770 -12 common/image.c Ramdisk data has bad checksum 2771 11 common/image.c Ramdisk data has correct checksum 2772 12 common/image.c Ramdisk verification complete, start loading 2773 -13 common/image.c Wrong Image Type (not PPC Linux ramdisk) 2774 13 common/image.c Start multifile image verification 2775 14 common/image.c No initial ramdisk, no multifile, continue. 2776 2777 15 arch/<arch>/lib/bootm.c All preparation done, transferring control to OS 2778 2779 -30 arch/powerpc/lib/board.c Fatal error, hang the system 2780 -31 post/post.c POST test failed, detected by post_output_backlog() 2781 -32 post/post.c POST test failed, detected by post_run_single() 2782 2783 34 common/cmd_doc.c before loading a Image from a DOC device 2784 -35 common/cmd_doc.c Bad usage of "doc" command 2785 35 common/cmd_doc.c correct usage of "doc" command 2786 -36 common/cmd_doc.c No boot device 2787 36 common/cmd_doc.c correct boot device 2788 -37 common/cmd_doc.c Unknown Chip ID on boot device 2789 37 common/cmd_doc.c correct chip ID found, device available 2790 -38 common/cmd_doc.c Read Error on boot device 2791 38 common/cmd_doc.c reading Image header from DOC device OK 2792 -39 common/cmd_doc.c Image header has bad magic number 2793 39 common/cmd_doc.c Image header has correct magic number 2794 -40 common/cmd_doc.c Error reading Image from DOC device 2795 40 common/cmd_doc.c Image header has correct magic number 2796 41 common/cmd_ide.c before loading a Image from a IDE device 2797 -42 common/cmd_ide.c Bad usage of "ide" command 2798 42 common/cmd_ide.c correct usage of "ide" command 2799 -43 common/cmd_ide.c No boot device 2800 43 common/cmd_ide.c boot device found 2801 -44 common/cmd_ide.c Device not available 2802 44 common/cmd_ide.c Device available 2803 -45 common/cmd_ide.c wrong partition selected 2804 45 common/cmd_ide.c partition selected 2805 -46 common/cmd_ide.c Unknown partition table 2806 46 common/cmd_ide.c valid partition table found 2807 -47 common/cmd_ide.c Invalid partition type 2808 47 common/cmd_ide.c correct partition type 2809 -48 common/cmd_ide.c Error reading Image Header on boot device 2810 48 common/cmd_ide.c reading Image Header from IDE device OK 2811 -49 common/cmd_ide.c Image header has bad magic number 2812 49 common/cmd_ide.c Image header has correct magic number 2813 -50 common/cmd_ide.c Image header has bad checksum 2814 50 common/cmd_ide.c Image header has correct checksum 2815 -51 common/cmd_ide.c Error reading Image from IDE device 2816 51 common/cmd_ide.c reading Image from IDE device OK 2817 52 common/cmd_nand.c before loading a Image from a NAND device 2818 -53 common/cmd_nand.c Bad usage of "nand" command 2819 53 common/cmd_nand.c correct usage of "nand" command 2820 -54 common/cmd_nand.c No boot device 2821 54 common/cmd_nand.c boot device found 2822 -55 common/cmd_nand.c Unknown Chip ID on boot device 2823 55 common/cmd_nand.c correct chip ID found, device available 2824 -56 common/cmd_nand.c Error reading Image Header on boot device 2825 56 common/cmd_nand.c reading Image Header from NAND device OK 2826 -57 common/cmd_nand.c Image header has bad magic number 2827 57 common/cmd_nand.c Image header has correct magic number 2828 -58 common/cmd_nand.c Error reading Image from NAND device 2829 58 common/cmd_nand.c reading Image from NAND device OK 2830 2831 -60 common/env_common.c Environment has a bad CRC, using default 2832 2833 64 net/eth.c starting with Ethernet configuration. 2834 -64 net/eth.c no Ethernet found. 2835 65 net/eth.c Ethernet found. 2836 2837 -80 common/cmd_net.c usage wrong 2838 80 common/cmd_net.c before calling net_loop() 2839 -81 common/cmd_net.c some error in net_loop() occurred 2840 81 common/cmd_net.c net_loop() back without error 2841 -82 common/cmd_net.c size == 0 (File with size 0 loaded) 2842 82 common/cmd_net.c trying automatic boot 2843 83 common/cmd_net.c running "source" command 2844 -83 common/cmd_net.c some error in automatic boot or "source" command 2845 84 common/cmd_net.c end without errors 2846 2847FIT uImage format: 2848 2849 Arg Where When 2850 100 common/cmd_bootm.c Kernel FIT Image has correct format 2851 -100 common/cmd_bootm.c Kernel FIT Image has incorrect format 2852 101 common/cmd_bootm.c No Kernel subimage unit name, using configuration 2853 -101 common/cmd_bootm.c Can't get configuration for kernel subimage 2854 102 common/cmd_bootm.c Kernel unit name specified 2855 -103 common/cmd_bootm.c Can't get kernel subimage node offset 2856 103 common/cmd_bootm.c Found configuration node 2857 104 common/cmd_bootm.c Got kernel subimage node offset 2858 -104 common/cmd_bootm.c Kernel subimage hash verification failed 2859 105 common/cmd_bootm.c Kernel subimage hash verification OK 2860 -105 common/cmd_bootm.c Kernel subimage is for unsupported architecture 2861 106 common/cmd_bootm.c Architecture check OK 2862 -106 common/cmd_bootm.c Kernel subimage has wrong type 2863 107 common/cmd_bootm.c Kernel subimage type OK 2864 -107 common/cmd_bootm.c Can't get kernel subimage data/size 2865 108 common/cmd_bootm.c Got kernel subimage data/size 2866 -108 common/cmd_bootm.c Wrong image type (not legacy, FIT) 2867 -109 common/cmd_bootm.c Can't get kernel subimage type 2868 -110 common/cmd_bootm.c Can't get kernel subimage comp 2869 -111 common/cmd_bootm.c Can't get kernel subimage os 2870 -112 common/cmd_bootm.c Can't get kernel subimage load address 2871 -113 common/cmd_bootm.c Image uncompress/copy overwrite error 2872 2873 120 common/image.c Start initial ramdisk verification 2874 -120 common/image.c Ramdisk FIT image has incorrect format 2875 121 common/image.c Ramdisk FIT image has correct format 2876 122 common/image.c No ramdisk subimage unit name, using configuration 2877 -122 common/image.c Can't get configuration for ramdisk subimage 2878 123 common/image.c Ramdisk unit name specified 2879 -124 common/image.c Can't get ramdisk subimage node offset 2880 125 common/image.c Got ramdisk subimage node offset 2881 -125 common/image.c Ramdisk subimage hash verification failed 2882 126 common/image.c Ramdisk subimage hash verification OK 2883 -126 common/image.c Ramdisk subimage for unsupported architecture 2884 127 common/image.c Architecture check OK 2885 -127 common/image.c Can't get ramdisk subimage data/size 2886 128 common/image.c Got ramdisk subimage data/size 2887 129 common/image.c Can't get ramdisk load address 2888 -129 common/image.c Got ramdisk load address 2889 2890 -130 common/cmd_doc.c Incorrect FIT image format 2891 131 common/cmd_doc.c FIT image format OK 2892 2893 -140 common/cmd_ide.c Incorrect FIT image format 2894 141 common/cmd_ide.c FIT image format OK 2895 2896 -150 common/cmd_nand.c Incorrect FIT image format 2897 151 common/cmd_nand.c FIT image format OK 2898 2899- legacy image format: 2900 CONFIG_IMAGE_FORMAT_LEGACY 2901 enables the legacy image format support in U-Boot. 2902 2903 Default: 2904 enabled if CONFIG_FIT_SIGNATURE is not defined. 2905 2906 CONFIG_DISABLE_IMAGE_LEGACY 2907 disable the legacy image format 2908 2909 This define is introduced, as the legacy image format is 2910 enabled per default for backward compatibility. 2911 2912- Standalone program support: 2913 CONFIG_STANDALONE_LOAD_ADDR 2914 2915 This option defines a board specific value for the 2916 address where standalone program gets loaded, thus 2917 overwriting the architecture dependent default 2918 settings. 2919 2920- Frame Buffer Address: 2921 CONFIG_FB_ADDR 2922 2923 Define CONFIG_FB_ADDR if you want to use specific 2924 address for frame buffer. This is typically the case 2925 when using a graphics controller has separate video 2926 memory. U-Boot will then place the frame buffer at 2927 the given address instead of dynamically reserving it 2928 in system RAM by calling lcd_setmem(), which grabs 2929 the memory for the frame buffer depending on the 2930 configured panel size. 2931 2932 Please see board_init_f function. 2933 2934- Automatic software updates via TFTP server 2935 CONFIG_UPDATE_TFTP 2936 CONFIG_UPDATE_TFTP_CNT_MAX 2937 CONFIG_UPDATE_TFTP_MSEC_MAX 2938 2939 These options enable and control the auto-update feature; 2940 for a more detailed description refer to doc/README.update. 2941 2942- MTD Support (mtdparts command, UBI support) 2943 CONFIG_MTD_DEVICE 2944 2945 Adds the MTD device infrastructure from the Linux kernel. 2946 Needed for mtdparts command support. 2947 2948 CONFIG_MTD_PARTITIONS 2949 2950 Adds the MTD partitioning infrastructure from the Linux 2951 kernel. Needed for UBI support. 2952 2953- UBI support 2954 CONFIG_CMD_UBI 2955 2956 Adds commands for interacting with MTD partitions formatted 2957 with the UBI flash translation layer 2958 2959 Requires also defining CONFIG_RBTREE 2960 2961 CONFIG_UBI_SILENCE_MSG 2962 2963 Make the verbose messages from UBI stop printing. This leaves 2964 warnings and errors enabled. 2965 2966 2967 CONFIG_MTD_UBI_WL_THRESHOLD 2968 This parameter defines the maximum difference between the highest 2969 erase counter value and the lowest erase counter value of eraseblocks 2970 of UBI devices. When this threshold is exceeded, UBI starts performing 2971 wear leveling by means of moving data from eraseblock with low erase 2972 counter to eraseblocks with high erase counter. 2973 2974 The default value should be OK for SLC NAND flashes, NOR flashes and 2975 other flashes which have eraseblock life-cycle 100000 or more. 2976 However, in case of MLC NAND flashes which typically have eraseblock 2977 life-cycle less than 10000, the threshold should be lessened (e.g., 2978 to 128 or 256, although it does not have to be power of 2). 2979 2980 default: 4096 2981 2982 CONFIG_MTD_UBI_BEB_LIMIT 2983 This option specifies the maximum bad physical eraseblocks UBI 2984 expects on the MTD device (per 1024 eraseblocks). If the 2985 underlying flash does not admit of bad eraseblocks (e.g. NOR 2986 flash), this value is ignored. 2987 2988 NAND datasheets often specify the minimum and maximum NVM 2989 (Number of Valid Blocks) for the flashes' endurance lifetime. 2990 The maximum expected bad eraseblocks per 1024 eraseblocks 2991 then can be calculated as "1024 * (1 - MinNVB / MaxNVB)", 2992 which gives 20 for most NANDs (MaxNVB is basically the total 2993 count of eraseblocks on the chip). 2994 2995 To put it differently, if this value is 20, UBI will try to 2996 reserve about 1.9% of physical eraseblocks for bad blocks 2997 handling. And that will be 1.9% of eraseblocks on the entire 2998 NAND chip, not just the MTD partition UBI attaches. This means 2999 that if you have, say, a NAND flash chip admits maximum 40 bad 3000 eraseblocks, and it is split on two MTD partitions of the same 3001 size, UBI will reserve 40 eraseblocks when attaching a 3002 partition. 3003 3004 default: 20 3005 3006 CONFIG_MTD_UBI_FASTMAP 3007 Fastmap is a mechanism which allows attaching an UBI device 3008 in nearly constant time. Instead of scanning the whole MTD device it 3009 only has to locate a checkpoint (called fastmap) on the device. 3010 The on-flash fastmap contains all information needed to attach 3011 the device. Using fastmap makes only sense on large devices where 3012 attaching by scanning takes long. UBI will not automatically install 3013 a fastmap on old images, but you can set the UBI parameter 3014 CONFIG_MTD_UBI_FASTMAP_AUTOCONVERT to 1 if you want so. Please note 3015 that fastmap-enabled images are still usable with UBI implementations 3016 without fastmap support. On typical flash devices the whole fastmap 3017 fits into one PEB. UBI will reserve PEBs to hold two fastmaps. 3018 3019 CONFIG_MTD_UBI_FASTMAP_AUTOCONVERT 3020 Set this parameter to enable fastmap automatically on images 3021 without a fastmap. 3022 default: 0 3023 3024 CONFIG_MTD_UBI_FM_DEBUG 3025 Enable UBI fastmap debug 3026 default: 0 3027 3028- UBIFS support 3029 CONFIG_CMD_UBIFS 3030 3031 Adds commands for interacting with UBI volumes formatted as 3032 UBIFS. UBIFS is read-only in u-boot. 3033 3034 Requires UBI support as well as CONFIG_LZO 3035 3036 CONFIG_UBIFS_SILENCE_MSG 3037 3038 Make the verbose messages from UBIFS stop printing. This leaves 3039 warnings and errors enabled. 3040 3041- SPL framework 3042 CONFIG_SPL 3043 Enable building of SPL globally. 3044 3045 CONFIG_SPL_LDSCRIPT 3046 LDSCRIPT for linking the SPL binary. 3047 3048 CONFIG_SPL_MAX_FOOTPRINT 3049 Maximum size in memory allocated to the SPL, BSS included. 3050 When defined, the linker checks that the actual memory 3051 used by SPL from _start to __bss_end does not exceed it. 3052 CONFIG_SPL_MAX_FOOTPRINT and CONFIG_SPL_BSS_MAX_SIZE 3053 must not be both defined at the same time. 3054 3055 CONFIG_SPL_MAX_SIZE 3056 Maximum size of the SPL image (text, data, rodata, and 3057 linker lists sections), BSS excluded. 3058 When defined, the linker checks that the actual size does 3059 not exceed it. 3060 3061 CONFIG_SPL_TEXT_BASE 3062 TEXT_BASE for linking the SPL binary. 3063 3064 CONFIG_SPL_RELOC_TEXT_BASE 3065 Address to relocate to. If unspecified, this is equal to 3066 CONFIG_SPL_TEXT_BASE (i.e. no relocation is done). 3067 3068 CONFIG_SPL_BSS_START_ADDR 3069 Link address for the BSS within the SPL binary. 3070 3071 CONFIG_SPL_BSS_MAX_SIZE 3072 Maximum size in memory allocated to the SPL BSS. 3073 When defined, the linker checks that the actual memory used 3074 by SPL from __bss_start to __bss_end does not exceed it. 3075 CONFIG_SPL_MAX_FOOTPRINT and CONFIG_SPL_BSS_MAX_SIZE 3076 must not be both defined at the same time. 3077 3078 CONFIG_SPL_STACK 3079 Adress of the start of the stack SPL will use 3080 3081 CONFIG_SPL_PANIC_ON_RAW_IMAGE 3082 When defined, SPL will panic() if the image it has 3083 loaded does not have a signature. 3084 Defining this is useful when code which loads images 3085 in SPL cannot guarantee that absolutely all read errors 3086 will be caught. 3087 An example is the LPC32XX MLC NAND driver, which will 3088 consider that a completely unreadable NAND block is bad, 3089 and thus should be skipped silently. 3090 3091 CONFIG_SPL_RELOC_STACK 3092 Adress of the start of the stack SPL will use after 3093 relocation. If unspecified, this is equal to 3094 CONFIG_SPL_STACK. 3095 3096 CONFIG_SYS_SPL_MALLOC_START 3097 Starting address of the malloc pool used in SPL. 3098 When this option is set the full malloc is used in SPL and 3099 it is set up by spl_init() and before that, the simple malloc() 3100 can be used if CONFIG_SYS_MALLOC_F is defined. 3101 3102 CONFIG_SYS_SPL_MALLOC_SIZE 3103 The size of the malloc pool used in SPL. 3104 3105 CONFIG_SPL_FRAMEWORK 3106 Enable the SPL framework under common/. This framework 3107 supports MMC, NAND and YMODEM loading of U-Boot and NAND 3108 NAND loading of the Linux Kernel. 3109 3110 CONFIG_SPL_OS_BOOT 3111 Enable booting directly to an OS from SPL. 3112 See also: doc/README.falcon 3113 3114 CONFIG_SPL_DISPLAY_PRINT 3115 For ARM, enable an optional function to print more information 3116 about the running system. 3117 3118 CONFIG_SPL_INIT_MINIMAL 3119 Arch init code should be built for a very small image 3120 3121 CONFIG_SYS_MMCSD_RAW_MODE_U_BOOT_PARTITION 3122 Partition on the MMC to load U-Boot from when the MMC is being 3123 used in raw mode 3124 3125 CONFIG_SYS_MMCSD_RAW_MODE_KERNEL_SECTOR 3126 Sector to load kernel uImage from when MMC is being 3127 used in raw mode (for Falcon mode) 3128 3129 CONFIG_SYS_MMCSD_RAW_MODE_ARGS_SECTOR, 3130 CONFIG_SYS_MMCSD_RAW_MODE_ARGS_SECTORS 3131 Sector and number of sectors to load kernel argument 3132 parameters from when MMC is being used in raw mode 3133 (for falcon mode) 3134 3135 CONFIG_SYS_MMCSD_FS_BOOT_PARTITION 3136 Partition on the MMC to load U-Boot from when the MMC is being 3137 used in fs mode 3138 3139 CONFIG_SPL_FS_LOAD_PAYLOAD_NAME 3140 Filename to read to load U-Boot when reading from filesystem 3141 3142 CONFIG_SPL_FS_LOAD_KERNEL_NAME 3143 Filename to read to load kernel uImage when reading 3144 from filesystem (for Falcon mode) 3145 3146 CONFIG_SPL_FS_LOAD_ARGS_NAME 3147 Filename to read to load kernel argument parameters 3148 when reading from filesystem (for Falcon mode) 3149 3150 CONFIG_SPL_MPC83XX_WAIT_FOR_NAND 3151 Set this for NAND SPL on PPC mpc83xx targets, so that 3152 start.S waits for the rest of the SPL to load before 3153 continuing (the hardware starts execution after just 3154 loading the first page rather than the full 4K). 3155 3156 CONFIG_SPL_SKIP_RELOCATE 3157 Avoid SPL relocation 3158 3159 CONFIG_SPL_NAND_BASE 3160 Include nand_base.c in the SPL. Requires 3161 CONFIG_SPL_NAND_DRIVERS. 3162 3163 CONFIG_SPL_NAND_DRIVERS 3164 SPL uses normal NAND drivers, not minimal drivers. 3165 3166 CONFIG_SPL_NAND_ECC 3167 Include standard software ECC in the SPL 3168 3169 CONFIG_SPL_NAND_SIMPLE 3170 Support for NAND boot using simple NAND drivers that 3171 expose the cmd_ctrl() interface. 3172 3173 CONFIG_SPL_UBI 3174 Support for a lightweight UBI (fastmap) scanner and 3175 loader 3176 3177 CONFIG_SPL_NAND_RAW_ONLY 3178 Support to boot only raw u-boot.bin images. Use this only 3179 if you need to save space. 3180 3181 CONFIG_SPL_COMMON_INIT_DDR 3182 Set for common ddr init with serial presence detect in 3183 SPL binary. 3184 3185 CONFIG_SYS_NAND_5_ADDR_CYCLE, CONFIG_SYS_NAND_PAGE_COUNT, 3186 CONFIG_SYS_NAND_PAGE_SIZE, CONFIG_SYS_NAND_OOBSIZE, 3187 CONFIG_SYS_NAND_BLOCK_SIZE, CONFIG_SYS_NAND_BAD_BLOCK_POS, 3188 CONFIG_SYS_NAND_ECCPOS, CONFIG_SYS_NAND_ECCSIZE, 3189 CONFIG_SYS_NAND_ECCBYTES 3190 Defines the size and behavior of the NAND that SPL uses 3191 to read U-Boot 3192 3193 CONFIG_SPL_NAND_BOOT 3194 Add support NAND boot 3195 3196 CONFIG_SYS_NAND_U_BOOT_OFFS 3197 Location in NAND to read U-Boot from 3198 3199 CONFIG_SYS_NAND_U_BOOT_DST 3200 Location in memory to load U-Boot to 3201 3202 CONFIG_SYS_NAND_U_BOOT_SIZE 3203 Size of image to load 3204 3205 CONFIG_SYS_NAND_U_BOOT_START 3206 Entry point in loaded image to jump to 3207 3208 CONFIG_SYS_NAND_HW_ECC_OOBFIRST 3209 Define this if you need to first read the OOB and then the 3210 data. This is used, for example, on davinci platforms. 3211 3212 CONFIG_SPL_OMAP3_ID_NAND 3213 Support for an OMAP3-specific set of functions to return the 3214 ID and MFR of the first attached NAND chip, if present. 3215 3216 CONFIG_SPL_RAM_DEVICE 3217 Support for running image already present in ram, in SPL binary 3218 3219 CONFIG_SPL_PAD_TO 3220 Image offset to which the SPL should be padded before appending 3221 the SPL payload. By default, this is defined as 3222 CONFIG_SPL_MAX_SIZE, or 0 if CONFIG_SPL_MAX_SIZE is undefined. 3223 CONFIG_SPL_PAD_TO must be either 0, meaning to append the SPL 3224 payload without any padding, or >= CONFIG_SPL_MAX_SIZE. 3225 3226 CONFIG_SPL_TARGET 3227 Final target image containing SPL and payload. Some SPLs 3228 use an arch-specific makefile fragment instead, for 3229 example if more than one image needs to be produced. 3230 3231 CONFIG_FIT_SPL_PRINT 3232 Printing information about a FIT image adds quite a bit of 3233 code to SPL. So this is normally disabled in SPL. Use this 3234 option to re-enable it. This will affect the output of the 3235 bootm command when booting a FIT image. 3236 3237- TPL framework 3238 CONFIG_TPL 3239 Enable building of TPL globally. 3240 3241 CONFIG_TPL_PAD_TO 3242 Image offset to which the TPL should be padded before appending 3243 the TPL payload. By default, this is defined as 3244 CONFIG_SPL_MAX_SIZE, or 0 if CONFIG_SPL_MAX_SIZE is undefined. 3245 CONFIG_SPL_PAD_TO must be either 0, meaning to append the SPL 3246 payload without any padding, or >= CONFIG_SPL_MAX_SIZE. 3247 3248- Interrupt support (PPC): 3249 3250 There are common interrupt_init() and timer_interrupt() 3251 for all PPC archs. interrupt_init() calls interrupt_init_cpu() 3252 for CPU specific initialization. interrupt_init_cpu() 3253 should set decrementer_count to appropriate value. If 3254 CPU resets decrementer automatically after interrupt 3255 (ppc4xx) it should set decrementer_count to zero. 3256 timer_interrupt() calls timer_interrupt_cpu() for CPU 3257 specific handling. If board has watchdog / status_led 3258 / other_activity_monitor it works automatically from 3259 general timer_interrupt(). 3260 3261 3262Board initialization settings: 3263------------------------------ 3264 3265During Initialization u-boot calls a number of board specific functions 3266to allow the preparation of board specific prerequisites, e.g. pin setup 3267before drivers are initialized. To enable these callbacks the 3268following configuration macros have to be defined. Currently this is 3269architecture specific, so please check arch/your_architecture/lib/board.c 3270typically in board_init_f() and board_init_r(). 3271 3272- CONFIG_BOARD_EARLY_INIT_F: Call board_early_init_f() 3273- CONFIG_BOARD_EARLY_INIT_R: Call board_early_init_r() 3274- CONFIG_BOARD_LATE_INIT: Call board_late_init() 3275- CONFIG_BOARD_POSTCLK_INIT: Call board_postclk_init() 3276 3277Configuration Settings: 3278----------------------- 3279 3280- CONFIG_SYS_SUPPORT_64BIT_DATA: Defined automatically if compiled as 64-bit. 3281 Optionally it can be defined to support 64-bit memory commands. 3282 3283- CONFIG_SYS_LONGHELP: Defined when you want long help messages included; 3284 undefine this when you're short of memory. 3285 3286- CONFIG_SYS_HELP_CMD_WIDTH: Defined when you want to override the default 3287 width of the commands listed in the 'help' command output. 3288 3289- CONFIG_SYS_PROMPT: This is what U-Boot prints on the console to 3290 prompt for user input. 3291 3292- CONFIG_SYS_CBSIZE: Buffer size for input from the Console 3293 3294- CONFIG_SYS_PBSIZE: Buffer size for Console output 3295 3296- CONFIG_SYS_MAXARGS: max. Number of arguments accepted for monitor commands 3297 3298- CONFIG_SYS_BARGSIZE: Buffer size for Boot Arguments which are passed to 3299 the application (usually a Linux kernel) when it is 3300 booted 3301 3302- CONFIG_SYS_BAUDRATE_TABLE: 3303 List of legal baudrate settings for this board. 3304 3305- CONFIG_SYS_MEMTEST_START, CONFIG_SYS_MEMTEST_END: 3306 Begin and End addresses of the area used by the 3307 simple memory test. 3308 3309- CONFIG_SYS_ALT_MEMTEST: 3310 Enable an alternate, more extensive memory test. 3311 3312- CONFIG_SYS_MEMTEST_SCRATCH: 3313 Scratch address used by the alternate memory test 3314 You only need to set this if address zero isn't writeable 3315 3316- CONFIG_SYS_MEM_RESERVE_SECURE 3317 Only implemented for ARMv8 for now. 3318 If defined, the size of CONFIG_SYS_MEM_RESERVE_SECURE memory 3319 is substracted from total RAM and won't be reported to OS. 3320 This memory can be used as secure memory. A variable 3321 gd->arch.secure_ram is used to track the location. In systems 3322 the RAM base is not zero, or RAM is divided into banks, 3323 this variable needs to be recalcuated to get the address. 3324 3325- CONFIG_SYS_MEM_TOP_HIDE: 3326 If CONFIG_SYS_MEM_TOP_HIDE is defined in the board config header, 3327 this specified memory area will get subtracted from the top 3328 (end) of RAM and won't get "touched" at all by U-Boot. By 3329 fixing up gd->ram_size the Linux kernel should gets passed 3330 the now "corrected" memory size and won't touch it either. 3331 This should work for arch/ppc and arch/powerpc. Only Linux 3332 board ports in arch/powerpc with bootwrapper support that 3333 recalculate the memory size from the SDRAM controller setup 3334 will have to get fixed in Linux additionally. 3335 3336 This option can be used as a workaround for the 440EPx/GRx 3337 CHIP 11 errata where the last 256 bytes in SDRAM shouldn't 3338 be touched. 3339 3340 WARNING: Please make sure that this value is a multiple of 3341 the Linux page size (normally 4k). If this is not the case, 3342 then the end address of the Linux memory will be located at a 3343 non page size aligned address and this could cause major 3344 problems. 3345 3346- CONFIG_SYS_LOADS_BAUD_CHANGE: 3347 Enable temporary baudrate change while serial download 3348 3349- CONFIG_SYS_SDRAM_BASE: 3350 Physical start address of SDRAM. _Must_ be 0 here. 3351 3352- CONFIG_SYS_FLASH_BASE: 3353 Physical start address of Flash memory. 3354 3355- CONFIG_SYS_MONITOR_BASE: 3356 Physical start address of boot monitor code (set by 3357 make config files to be same as the text base address 3358 (CONFIG_SYS_TEXT_BASE) used when linking) - same as 3359 CONFIG_SYS_FLASH_BASE when booting from flash. 3360 3361- CONFIG_SYS_MONITOR_LEN: 3362 Size of memory reserved for monitor code, used to 3363 determine _at_compile_time_ (!) if the environment is 3364 embedded within the U-Boot image, or in a separate 3365 flash sector. 3366 3367- CONFIG_SYS_MALLOC_LEN: 3368 Size of DRAM reserved for malloc() use. 3369 3370- CONFIG_SYS_MALLOC_F_LEN 3371 Size of the malloc() pool for use before relocation. If 3372 this is defined, then a very simple malloc() implementation 3373 will become available before relocation. The address is just 3374 below the global data, and the stack is moved down to make 3375 space. 3376 3377 This feature allocates regions with increasing addresses 3378 within the region. calloc() is supported, but realloc() 3379 is not available. free() is supported but does nothing. 3380 The memory will be freed (or in fact just forgotten) when 3381 U-Boot relocates itself. 3382 3383- CONFIG_SYS_MALLOC_SIMPLE 3384 Provides a simple and small malloc() and calloc() for those 3385 boards which do not use the full malloc in SPL (which is 3386 enabled with CONFIG_SYS_SPL_MALLOC_START). 3387 3388- CONFIG_SYS_NONCACHED_MEMORY: 3389 Size of non-cached memory area. This area of memory will be 3390 typically located right below the malloc() area and mapped 3391 uncached in the MMU. This is useful for drivers that would 3392 otherwise require a lot of explicit cache maintenance. For 3393 some drivers it's also impossible to properly maintain the 3394 cache. For example if the regions that need to be flushed 3395 are not a multiple of the cache-line size, *and* padding 3396 cannot be allocated between the regions to align them (i.e. 3397 if the HW requires a contiguous array of regions, and the 3398 size of each region is not cache-aligned), then a flush of 3399 one region may result in overwriting data that hardware has 3400 written to another region in the same cache-line. This can 3401 happen for example in network drivers where descriptors for 3402 buffers are typically smaller than the CPU cache-line (e.g. 3403 16 bytes vs. 32 or 64 bytes). 3404 3405 Non-cached memory is only supported on 32-bit ARM at present. 3406 3407- CONFIG_SYS_BOOTM_LEN: 3408 Normally compressed uImages are limited to an 3409 uncompressed size of 8 MBytes. If this is not enough, 3410 you can define CONFIG_SYS_BOOTM_LEN in your board config file 3411 to adjust this setting to your needs. 3412 3413- CONFIG_SYS_BOOTMAPSZ: 3414 Maximum size of memory mapped by the startup code of 3415 the Linux kernel; all data that must be processed by 3416 the Linux kernel (bd_info, boot arguments, FDT blob if 3417 used) must be put below this limit, unless "bootm_low" 3418 environment variable is defined and non-zero. In such case 3419 all data for the Linux kernel must be between "bootm_low" 3420 and "bootm_low" + CONFIG_SYS_BOOTMAPSZ. The environment 3421 variable "bootm_mapsize" will override the value of 3422 CONFIG_SYS_BOOTMAPSZ. If CONFIG_SYS_BOOTMAPSZ is undefined, 3423 then the value in "bootm_size" will be used instead. 3424 3425- CONFIG_SYS_BOOT_RAMDISK_HIGH: 3426 Enable initrd_high functionality. If defined then the 3427 initrd_high feature is enabled and the bootm ramdisk subcommand 3428 is enabled. 3429 3430- CONFIG_SYS_BOOT_GET_CMDLINE: 3431 Enables allocating and saving kernel cmdline in space between 3432 "bootm_low" and "bootm_low" + BOOTMAPSZ. 3433 3434- CONFIG_SYS_BOOT_GET_KBD: 3435 Enables allocating and saving a kernel copy of the bd_info in 3436 space between "bootm_low" and "bootm_low" + BOOTMAPSZ. 3437 3438- CONFIG_SYS_MAX_FLASH_BANKS: 3439 Max number of Flash memory banks 3440 3441- CONFIG_SYS_MAX_FLASH_SECT: 3442 Max number of sectors on a Flash chip 3443 3444- CONFIG_SYS_FLASH_ERASE_TOUT: 3445 Timeout for Flash erase operations (in ms) 3446 3447- CONFIG_SYS_FLASH_WRITE_TOUT: 3448 Timeout for Flash write operations (in ms) 3449 3450- CONFIG_SYS_FLASH_LOCK_TOUT 3451 Timeout for Flash set sector lock bit operation (in ms) 3452 3453- CONFIG_SYS_FLASH_UNLOCK_TOUT 3454 Timeout for Flash clear lock bits operation (in ms) 3455 3456- CONFIG_SYS_FLASH_PROTECTION 3457 If defined, hardware flash sectors protection is used 3458 instead of U-Boot software protection. 3459 3460- CONFIG_SYS_DIRECT_FLASH_TFTP: 3461 3462 Enable TFTP transfers directly to flash memory; 3463 without this option such a download has to be 3464 performed in two steps: (1) download to RAM, and (2) 3465 copy from RAM to flash. 3466 3467 The two-step approach is usually more reliable, since 3468 you can check if the download worked before you erase 3469 the flash, but in some situations (when system RAM is 3470 too limited to allow for a temporary copy of the 3471 downloaded image) this option may be very useful. 3472 3473- CONFIG_SYS_FLASH_CFI: 3474 Define if the flash driver uses extra elements in the 3475 common flash structure for storing flash geometry. 3476 3477- CONFIG_FLASH_CFI_DRIVER 3478 This option also enables the building of the cfi_flash driver 3479 in the drivers directory 3480 3481- CONFIG_FLASH_CFI_MTD 3482 This option enables the building of the cfi_mtd driver 3483 in the drivers directory. The driver exports CFI flash 3484 to the MTD layer. 3485 3486- CONFIG_SYS_FLASH_USE_BUFFER_WRITE 3487 Use buffered writes to flash. 3488 3489- CONFIG_FLASH_SPANSION_S29WS_N 3490 s29ws-n MirrorBit flash has non-standard addresses for buffered 3491 write commands. 3492 3493- CONFIG_SYS_FLASH_QUIET_TEST 3494 If this option is defined, the common CFI flash doesn't 3495 print it's warning upon not recognized FLASH banks. This 3496 is useful, if some of the configured banks are only 3497 optionally available. 3498 3499- CONFIG_FLASH_SHOW_PROGRESS 3500 If defined (must be an integer), print out countdown 3501 digits and dots. Recommended value: 45 (9..1) for 80 3502 column displays, 15 (3..1) for 40 column displays. 3503 3504- CONFIG_FLASH_VERIFY 3505 If defined, the content of the flash (destination) is compared 3506 against the source after the write operation. An error message 3507 will be printed when the contents are not identical. 3508 Please note that this option is useless in nearly all cases, 3509 since such flash programming errors usually are detected earlier 3510 while unprotecting/erasing/programming. Please only enable 3511 this option if you really know what you are doing. 3512 3513- CONFIG_SYS_RX_ETH_BUFFER: 3514 Defines the number of Ethernet receive buffers. On some 3515 Ethernet controllers it is recommended to set this value 3516 to 8 or even higher (EEPRO100 or 405 EMAC), since all 3517 buffers can be full shortly after enabling the interface 3518 on high Ethernet traffic. 3519 Defaults to 4 if not defined. 3520 3521- CONFIG_ENV_MAX_ENTRIES 3522 3523 Maximum number of entries in the hash table that is used 3524 internally to store the environment settings. The default 3525 setting is supposed to be generous and should work in most 3526 cases. This setting can be used to tune behaviour; see 3527 lib/hashtable.c for details. 3528 3529- CONFIG_ENV_FLAGS_LIST_DEFAULT 3530- CONFIG_ENV_FLAGS_LIST_STATIC 3531 Enable validation of the values given to environment variables when 3532 calling env set. Variables can be restricted to only decimal, 3533 hexadecimal, or boolean. If CONFIG_CMD_NET is also defined, 3534 the variables can also be restricted to IP address or MAC address. 3535 3536 The format of the list is: 3537 type_attribute = [s|d|x|b|i|m] 3538 access_attribute = [a|r|o|c] 3539 attributes = type_attribute[access_attribute] 3540 entry = variable_name[:attributes] 3541 list = entry[,list] 3542 3543 The type attributes are: 3544 s - String (default) 3545 d - Decimal 3546 x - Hexadecimal 3547 b - Boolean ([1yYtT|0nNfF]) 3548 i - IP address 3549 m - MAC address 3550 3551 The access attributes are: 3552 a - Any (default) 3553 r - Read-only 3554 o - Write-once 3555 c - Change-default 3556 3557 - CONFIG_ENV_FLAGS_LIST_DEFAULT 3558 Define this to a list (string) to define the ".flags" 3559 environment variable in the default or embedded environment. 3560 3561 - CONFIG_ENV_FLAGS_LIST_STATIC 3562 Define this to a list (string) to define validation that 3563 should be done if an entry is not found in the ".flags" 3564 environment variable. To override a setting in the static 3565 list, simply add an entry for the same variable name to the 3566 ".flags" variable. 3567 3568 If CONFIG_REGEX is defined, the variable_name above is evaluated as a 3569 regular expression. This allows multiple variables to define the same 3570 flags without explicitly listing them for each variable. 3571 3572- CONFIG_ENV_ACCESS_IGNORE_FORCE 3573 If defined, don't allow the -f switch to env set override variable 3574 access flags. 3575 3576- CONFIG_USE_STDINT 3577 If stdint.h is available with your toolchain you can define this 3578 option to enable it. You can provide option 'USE_STDINT=1' when 3579 building U-Boot to enable this. 3580 3581The following definitions that deal with the placement and management 3582of environment data (variable area); in general, we support the 3583following configurations: 3584 3585- CONFIG_BUILD_ENVCRC: 3586 3587 Builds up envcrc with the target environment so that external utils 3588 may easily extract it and embed it in final U-Boot images. 3589 3590- CONFIG_ENV_IS_IN_FLASH: 3591 3592 Define this if the environment is in flash memory. 3593 3594 a) The environment occupies one whole flash sector, which is 3595 "embedded" in the text segment with the U-Boot code. This 3596 happens usually with "bottom boot sector" or "top boot 3597 sector" type flash chips, which have several smaller 3598 sectors at the start or the end. For instance, such a 3599 layout can have sector sizes of 8, 2x4, 16, Nx32 kB. In 3600 such a case you would place the environment in one of the 3601 4 kB sectors - with U-Boot code before and after it. With 3602 "top boot sector" type flash chips, you would put the 3603 environment in one of the last sectors, leaving a gap 3604 between U-Boot and the environment. 3605 3606 - CONFIG_ENV_OFFSET: 3607 3608 Offset of environment data (variable area) to the 3609 beginning of flash memory; for instance, with bottom boot 3610 type flash chips the second sector can be used: the offset 3611 for this sector is given here. 3612 3613 CONFIG_ENV_OFFSET is used relative to CONFIG_SYS_FLASH_BASE. 3614 3615 - CONFIG_ENV_ADDR: 3616 3617 This is just another way to specify the start address of 3618 the flash sector containing the environment (instead of 3619 CONFIG_ENV_OFFSET). 3620 3621 - CONFIG_ENV_SECT_SIZE: 3622 3623 Size of the sector containing the environment. 3624 3625 3626 b) Sometimes flash chips have few, equal sized, BIG sectors. 3627 In such a case you don't want to spend a whole sector for 3628 the environment. 3629 3630 - CONFIG_ENV_SIZE: 3631 3632 If you use this in combination with CONFIG_ENV_IS_IN_FLASH 3633 and CONFIG_ENV_SECT_SIZE, you can specify to use only a part 3634 of this flash sector for the environment. This saves 3635 memory for the RAM copy of the environment. 3636 3637 It may also save flash memory if you decide to use this 3638 when your environment is "embedded" within U-Boot code, 3639 since then the remainder of the flash sector could be used 3640 for U-Boot code. It should be pointed out that this is 3641 STRONGLY DISCOURAGED from a robustness point of view: 3642 updating the environment in flash makes it always 3643 necessary to erase the WHOLE sector. If something goes 3644 wrong before the contents has been restored from a copy in 3645 RAM, your target system will be dead. 3646 3647 - CONFIG_ENV_ADDR_REDUND 3648 CONFIG_ENV_SIZE_REDUND 3649 3650 These settings describe a second storage area used to hold 3651 a redundant copy of the environment data, so that there is 3652 a valid backup copy in case there is a power failure during 3653 a "saveenv" operation. 3654 3655BE CAREFUL! Any changes to the flash layout, and some changes to the 3656source code will make it necessary to adapt <board>/u-boot.lds* 3657accordingly! 3658 3659 3660- CONFIG_ENV_IS_IN_NVRAM: 3661 3662 Define this if you have some non-volatile memory device 3663 (NVRAM, battery buffered SRAM) which you want to use for the 3664 environment. 3665 3666 - CONFIG_ENV_ADDR: 3667 - CONFIG_ENV_SIZE: 3668 3669 These two #defines are used to determine the memory area you 3670 want to use for environment. It is assumed that this memory 3671 can just be read and written to, without any special 3672 provision. 3673 3674BE CAREFUL! The first access to the environment happens quite early 3675in U-Boot initialization (when we try to get the setting of for the 3676console baudrate). You *MUST* have mapped your NVRAM area then, or 3677U-Boot will hang. 3678 3679Please note that even with NVRAM we still use a copy of the 3680environment in RAM: we could work on NVRAM directly, but we want to 3681keep settings there always unmodified except somebody uses "saveenv" 3682to save the current settings. 3683 3684 3685- CONFIG_ENV_IS_IN_EEPROM: 3686 3687 Use this if you have an EEPROM or similar serial access 3688 device and a driver for it. 3689 3690 - CONFIG_ENV_OFFSET: 3691 - CONFIG_ENV_SIZE: 3692 3693 These two #defines specify the offset and size of the 3694 environment area within the total memory of your EEPROM. 3695 3696 - CONFIG_SYS_I2C_EEPROM_ADDR: 3697 If defined, specified the chip address of the EEPROM device. 3698 The default address is zero. 3699 3700 - CONFIG_SYS_I2C_EEPROM_BUS: 3701 If defined, specified the i2c bus of the EEPROM device. 3702 3703 - CONFIG_SYS_EEPROM_PAGE_WRITE_BITS: 3704 If defined, the number of bits used to address bytes in a 3705 single page in the EEPROM device. A 64 byte page, for example 3706 would require six bits. 3707 3708 - CONFIG_SYS_EEPROM_PAGE_WRITE_DELAY_MS: 3709 If defined, the number of milliseconds to delay between 3710 page writes. The default is zero milliseconds. 3711 3712 - CONFIG_SYS_I2C_EEPROM_ADDR_LEN: 3713 The length in bytes of the EEPROM memory array address. Note 3714 that this is NOT the chip address length! 3715 3716 - CONFIG_SYS_I2C_EEPROM_ADDR_OVERFLOW: 3717 EEPROM chips that implement "address overflow" are ones 3718 like Catalyst 24WC04/08/16 which has 9/10/11 bits of 3719 address and the extra bits end up in the "chip address" bit 3720 slots. This makes a 24WC08 (1Kbyte) chip look like four 256 3721 byte chips. 3722 3723 Note that we consider the length of the address field to 3724 still be one byte because the extra address bits are hidden 3725 in the chip address. 3726 3727 - CONFIG_SYS_EEPROM_SIZE: 3728 The size in bytes of the EEPROM device. 3729 3730 - CONFIG_ENV_EEPROM_IS_ON_I2C 3731 define this, if you have I2C and SPI activated, and your 3732 EEPROM, which holds the environment, is on the I2C bus. 3733 3734 - CONFIG_I2C_ENV_EEPROM_BUS 3735 if you have an Environment on an EEPROM reached over 3736 I2C muxes, you can define here, how to reach this 3737 EEPROM. For example: 3738 3739 #define CONFIG_I2C_ENV_EEPROM_BUS 1 3740 3741 EEPROM which holds the environment, is reached over 3742 a pca9547 i2c mux with address 0x70, channel 3. 3743 3744- CONFIG_ENV_IS_IN_DATAFLASH: 3745 3746 Define this if you have a DataFlash memory device which you 3747 want to use for the environment. 3748 3749 - CONFIG_ENV_OFFSET: 3750 - CONFIG_ENV_ADDR: 3751 - CONFIG_ENV_SIZE: 3752 3753 These three #defines specify the offset and size of the 3754 environment area within the total memory of your DataFlash placed 3755 at the specified address. 3756 3757- CONFIG_ENV_IS_IN_SPI_FLASH: 3758 3759 Define this if you have a SPI Flash memory device which you 3760 want to use for the environment. 3761 3762 - CONFIG_ENV_OFFSET: 3763 - CONFIG_ENV_SIZE: 3764 3765 These two #defines specify the offset and size of the 3766 environment area within the SPI Flash. CONFIG_ENV_OFFSET must be 3767 aligned to an erase sector boundary. 3768 3769 - CONFIG_ENV_SECT_SIZE: 3770 3771 Define the SPI flash's sector size. 3772 3773 - CONFIG_ENV_OFFSET_REDUND (optional): 3774 3775 This setting describes a second storage area of CONFIG_ENV_SIZE 3776 size used to hold a redundant copy of the environment data, so 3777 that there is a valid backup copy in case there is a power failure 3778 during a "saveenv" operation. CONFIG_ENV_OFFSET_REDUND must be 3779 aligned to an erase sector boundary. 3780 3781 - CONFIG_ENV_SPI_BUS (optional): 3782 - CONFIG_ENV_SPI_CS (optional): 3783 3784 Define the SPI bus and chip select. If not defined they will be 0. 3785 3786 - CONFIG_ENV_SPI_MAX_HZ (optional): 3787 3788 Define the SPI max work clock. If not defined then use 1MHz. 3789 3790 - CONFIG_ENV_SPI_MODE (optional): 3791 3792 Define the SPI work mode. If not defined then use SPI_MODE_3. 3793 3794- CONFIG_ENV_IS_IN_REMOTE: 3795 3796 Define this if you have a remote memory space which you 3797 want to use for the local device's environment. 3798 3799 - CONFIG_ENV_ADDR: 3800 - CONFIG_ENV_SIZE: 3801 3802 These two #defines specify the address and size of the 3803 environment area within the remote memory space. The 3804 local device can get the environment from remote memory 3805 space by SRIO or PCIE links. 3806 3807BE CAREFUL! For some special cases, the local device can not use 3808"saveenv" command. For example, the local device will get the 3809environment stored in a remote NOR flash by SRIO or PCIE link, 3810but it can not erase, write this NOR flash by SRIO or PCIE interface. 3811 3812- CONFIG_ENV_IS_IN_NAND: 3813 3814 Define this if you have a NAND device which you want to use 3815 for the environment. 3816 3817 - CONFIG_ENV_OFFSET: 3818 - CONFIG_ENV_SIZE: 3819 3820 These two #defines specify the offset and size of the environment 3821 area within the first NAND device. CONFIG_ENV_OFFSET must be 3822 aligned to an erase block boundary. 3823 3824 - CONFIG_ENV_OFFSET_REDUND (optional): 3825 3826 This setting describes a second storage area of CONFIG_ENV_SIZE 3827 size used to hold a redundant copy of the environment data, so 3828 that there is a valid backup copy in case there is a power failure 3829 during a "saveenv" operation. CONFIG_ENV_OFFSET_REDUND must be 3830 aligned to an erase block boundary. 3831 3832 - CONFIG_ENV_RANGE (optional): 3833 3834 Specifies the length of the region in which the environment 3835 can be written. This should be a multiple of the NAND device's 3836 block size. Specifying a range with more erase blocks than 3837 are needed to hold CONFIG_ENV_SIZE allows bad blocks within 3838 the range to be avoided. 3839 3840 - CONFIG_ENV_OFFSET_OOB (optional): 3841 3842 Enables support for dynamically retrieving the offset of the 3843 environment from block zero's out-of-band data. The 3844 "nand env.oob" command can be used to record this offset. 3845 Currently, CONFIG_ENV_OFFSET_REDUND is not supported when 3846 using CONFIG_ENV_OFFSET_OOB. 3847 3848- CONFIG_NAND_ENV_DST 3849 3850 Defines address in RAM to which the nand_spl code should copy the 3851 environment. If redundant environment is used, it will be copied to 3852 CONFIG_NAND_ENV_DST + CONFIG_ENV_SIZE. 3853 3854- CONFIG_ENV_IS_IN_UBI: 3855 3856 Define this if you have an UBI volume that you want to use for the 3857 environment. This has the benefit of wear-leveling the environment 3858 accesses, which is important on NAND. 3859 3860 - CONFIG_ENV_UBI_PART: 3861 3862 Define this to a string that is the mtd partition containing the UBI. 3863 3864 - CONFIG_ENV_UBI_VOLUME: 3865 3866 Define this to the name of the volume that you want to store the 3867 environment in. 3868 3869 - CONFIG_ENV_UBI_VOLUME_REDUND: 3870 3871 Define this to the name of another volume to store a second copy of 3872 the environment in. This will enable redundant environments in UBI. 3873 It is assumed that both volumes are in the same MTD partition. 3874 3875 - CONFIG_UBI_SILENCE_MSG 3876 - CONFIG_UBIFS_SILENCE_MSG 3877 3878 You will probably want to define these to avoid a really noisy system 3879 when storing the env in UBI. 3880 3881- CONFIG_ENV_IS_IN_FAT: 3882 Define this if you want to use the FAT file system for the environment. 3883 3884 - FAT_ENV_INTERFACE: 3885 3886 Define this to a string that is the name of the block device. 3887 3888 - FAT_ENV_DEVICE_AND_PART: 3889 3890 Define this to a string to specify the partition of the device. It can 3891 be as following: 3892 3893 "D:P", "D:0", "D", "D:" or "D:auto" (D, P are integers. And P >= 1) 3894 - "D:P": device D partition P. Error occurs if device D has no 3895 partition table. 3896 - "D:0": device D. 3897 - "D" or "D:": device D partition 1 if device D has partition 3898 table, or the whole device D if has no partition 3899 table. 3900 - "D:auto": first partition in device D with bootable flag set. 3901 If none, first valid partition in device D. If no 3902 partition table then means device D. 3903 3904 - FAT_ENV_FILE: 3905 3906 It's a string of the FAT file name. This file use to store the 3907 environment. 3908 3909 - CONFIG_FAT_WRITE: 3910 This should be defined. Otherwise it cannot save the environment file. 3911 3912- CONFIG_ENV_IS_IN_MMC: 3913 3914 Define this if you have an MMC device which you want to use for the 3915 environment. 3916 3917 - CONFIG_SYS_MMC_ENV_DEV: 3918 3919 Specifies which MMC device the environment is stored in. 3920 3921 - CONFIG_SYS_MMC_ENV_PART (optional): 3922 3923 Specifies which MMC partition the environment is stored in. If not 3924 set, defaults to partition 0, the user area. Common values might be 3925 1 (first MMC boot partition), 2 (second MMC boot partition). 3926 3927 - CONFIG_ENV_OFFSET: 3928 - CONFIG_ENV_SIZE: 3929 3930 These two #defines specify the offset and size of the environment 3931 area within the specified MMC device. 3932 3933 If offset is positive (the usual case), it is treated as relative to 3934 the start of the MMC partition. If offset is negative, it is treated 3935 as relative to the end of the MMC partition. This can be useful if 3936 your board may be fitted with different MMC devices, which have 3937 different sizes for the MMC partitions, and you always want the 3938 environment placed at the very end of the partition, to leave the 3939 maximum possible space before it, to store other data. 3940 3941 These two values are in units of bytes, but must be aligned to an 3942 MMC sector boundary. 3943 3944 - CONFIG_ENV_OFFSET_REDUND (optional): 3945 3946 Specifies a second storage area, of CONFIG_ENV_SIZE size, used to 3947 hold a redundant copy of the environment data. This provides a 3948 valid backup copy in case the other copy is corrupted, e.g. due 3949 to a power failure during a "saveenv" operation. 3950 3951 This value may also be positive or negative; this is handled in the 3952 same way as CONFIG_ENV_OFFSET. 3953 3954 This value is also in units of bytes, but must also be aligned to 3955 an MMC sector boundary. 3956 3957 - CONFIG_ENV_SIZE_REDUND (optional): 3958 3959 This value need not be set, even when CONFIG_ENV_OFFSET_REDUND is 3960 set. If this value is set, it must be set to the same value as 3961 CONFIG_ENV_SIZE. 3962 3963- CONFIG_SYS_SPI_INIT_OFFSET 3964 3965 Defines offset to the initial SPI buffer area in DPRAM. The 3966 area is used at an early stage (ROM part) if the environment 3967 is configured to reside in the SPI EEPROM: We need a 520 byte 3968 scratch DPRAM area. It is used between the two initialization 3969 calls (spi_init_f() and spi_init_r()). A value of 0xB00 seems 3970 to be a good choice since it makes it far enough from the 3971 start of the data area as well as from the stack pointer. 3972 3973Please note that the environment is read-only until the monitor 3974has been relocated to RAM and a RAM copy of the environment has been 3975created; also, when using EEPROM you will have to use getenv_f() 3976until then to read environment variables. 3977 3978The environment is protected by a CRC32 checksum. Before the monitor 3979is relocated into RAM, as a result of a bad CRC you will be working 3980with the compiled-in default environment - *silently*!!! [This is 3981necessary, because the first environment variable we need is the 3982"baudrate" setting for the console - if we have a bad CRC, we don't 3983have any device yet where we could complain.] 3984 3985Note: once the monitor has been relocated, then it will complain if 3986the default environment is used; a new CRC is computed as soon as you 3987use the "saveenv" command to store a valid environment. 3988 3989- CONFIG_SYS_FAULT_ECHO_LINK_DOWN: 3990 Echo the inverted Ethernet link state to the fault LED. 3991 3992 Note: If this option is active, then CONFIG_SYS_FAULT_MII_ADDR 3993 also needs to be defined. 3994 3995- CONFIG_SYS_FAULT_MII_ADDR: 3996 MII address of the PHY to check for the Ethernet link state. 3997 3998- CONFIG_NS16550_MIN_FUNCTIONS: 3999 Define this if you desire to only have use of the NS16550_init 4000 and NS16550_putc functions for the serial driver located at 4001 drivers/serial/ns16550.c. This option is useful for saving 4002 space for already greatly restricted images, including but not 4003 limited to NAND_SPL configurations. 4004 4005- CONFIG_DISPLAY_BOARDINFO 4006 Display information about the board that U-Boot is running on 4007 when U-Boot starts up. The board function checkboard() is called 4008 to do this. 4009 4010- CONFIG_DISPLAY_BOARDINFO_LATE 4011 Similar to the previous option, but display this information 4012 later, once stdio is running and output goes to the LCD, if 4013 present. 4014 4015- CONFIG_BOARD_SIZE_LIMIT: 4016 Maximum size of the U-Boot image. When defined, the 4017 build system checks that the actual size does not 4018 exceed it. 4019 4020Low Level (hardware related) configuration options: 4021--------------------------------------------------- 4022 4023- CONFIG_SYS_CACHELINE_SIZE: 4024 Cache Line Size of the CPU. 4025 4026- CONFIG_SYS_DEFAULT_IMMR: 4027 Default address of the IMMR after system reset. 4028 4029 Needed on some 8260 systems (MPC8260ADS, PQ2FADS-ZU, 4030 and RPXsuper) to be able to adjust the position of 4031 the IMMR register after a reset. 4032 4033- CONFIG_SYS_CCSRBAR_DEFAULT: 4034 Default (power-on reset) physical address of CCSR on Freescale 4035 PowerPC SOCs. 4036 4037- CONFIG_SYS_CCSRBAR: 4038 Virtual address of CCSR. On a 32-bit build, this is typically 4039 the same value as CONFIG_SYS_CCSRBAR_DEFAULT. 4040 4041 CONFIG_SYS_DEFAULT_IMMR must also be set to this value, 4042 for cross-platform code that uses that macro instead. 4043 4044- CONFIG_SYS_CCSRBAR_PHYS: 4045 Physical address of CCSR. CCSR can be relocated to a new 4046 physical address, if desired. In this case, this macro should 4047 be set to that address. Otherwise, it should be set to the 4048 same value as CONFIG_SYS_CCSRBAR_DEFAULT. For example, CCSR 4049 is typically relocated on 36-bit builds. It is recommended 4050 that this macro be defined via the _HIGH and _LOW macros: 4051 4052 #define CONFIG_SYS_CCSRBAR_PHYS ((CONFIG_SYS_CCSRBAR_PHYS_HIGH 4053 * 1ull) << 32 | CONFIG_SYS_CCSRBAR_PHYS_LOW) 4054 4055- CONFIG_SYS_CCSRBAR_PHYS_HIGH: 4056 Bits 33-36 of CONFIG_SYS_CCSRBAR_PHYS. This value is typically 4057 either 0 (32-bit build) or 0xF (36-bit build). This macro is 4058 used in assembly code, so it must not contain typecasts or 4059 integer size suffixes (e.g. "ULL"). 4060 4061- CONFIG_SYS_CCSRBAR_PHYS_LOW: 4062 Lower 32-bits of CONFIG_SYS_CCSRBAR_PHYS. This macro is 4063 used in assembly code, so it must not contain typecasts or 4064 integer size suffixes (e.g. "ULL"). 4065 4066- CONFIG_SYS_CCSR_DO_NOT_RELOCATE: 4067 If this macro is defined, then CONFIG_SYS_CCSRBAR_PHYS will be 4068 forced to a value that ensures that CCSR is not relocated. 4069 4070- Floppy Disk Support: 4071 CONFIG_SYS_FDC_DRIVE_NUMBER 4072 4073 the default drive number (default value 0) 4074 4075 CONFIG_SYS_ISA_IO_STRIDE 4076 4077 defines the spacing between FDC chipset registers 4078 (default value 1) 4079 4080 CONFIG_SYS_ISA_IO_OFFSET 4081 4082 defines the offset of register from address. It 4083 depends on which part of the data bus is connected to 4084 the FDC chipset. (default value 0) 4085 4086 If CONFIG_SYS_ISA_IO_STRIDE CONFIG_SYS_ISA_IO_OFFSET and 4087 CONFIG_SYS_FDC_DRIVE_NUMBER are undefined, they take their 4088 default value. 4089 4090 if CONFIG_SYS_FDC_HW_INIT is defined, then the function 4091 fdc_hw_init() is called at the beginning of the FDC 4092 setup. fdc_hw_init() must be provided by the board 4093 source code. It is used to make hardware-dependent 4094 initializations. 4095 4096- CONFIG_IDE_AHB: 4097 Most IDE controllers were designed to be connected with PCI 4098 interface. Only few of them were designed for AHB interface. 4099 When software is doing ATA command and data transfer to 4100 IDE devices through IDE-AHB controller, some additional 4101 registers accessing to these kind of IDE-AHB controller 4102 is required. 4103 4104- CONFIG_SYS_IMMR: Physical address of the Internal Memory. 4105 DO NOT CHANGE unless you know exactly what you're 4106 doing! (11-4) [MPC8xx/82xx systems only] 4107 4108- CONFIG_SYS_INIT_RAM_ADDR: 4109 4110 Start address of memory area that can be used for 4111 initial data and stack; please note that this must be 4112 writable memory that is working WITHOUT special 4113 initialization, i. e. you CANNOT use normal RAM which 4114 will become available only after programming the 4115 memory controller and running certain initialization 4116 sequences. 4117 4118 U-Boot uses the following memory types: 4119 - MPC8xx and MPC8260: IMMR (internal memory of the CPU) 4120 - MPC824X: data cache 4121 - PPC4xx: data cache 4122 4123- CONFIG_SYS_GBL_DATA_OFFSET: 4124 4125 Offset of the initial data structure in the memory 4126 area defined by CONFIG_SYS_INIT_RAM_ADDR. Usually 4127 CONFIG_SYS_GBL_DATA_OFFSET is chosen such that the initial 4128 data is located at the end of the available space 4129 (sometimes written as (CONFIG_SYS_INIT_RAM_SIZE - 4130 GENERATED_GBL_DATA_SIZE), and the initial stack is just 4131 below that area (growing from (CONFIG_SYS_INIT_RAM_ADDR + 4132 CONFIG_SYS_GBL_DATA_OFFSET) downward. 4133 4134 Note: 4135 On the MPC824X (or other systems that use the data 4136 cache for initial memory) the address chosen for 4137 CONFIG_SYS_INIT_RAM_ADDR is basically arbitrary - it must 4138 point to an otherwise UNUSED address space between 4139 the top of RAM and the start of the PCI space. 4140 4141- CONFIG_SYS_SIUMCR: SIU Module Configuration (11-6) 4142 4143- CONFIG_SYS_SYPCR: System Protection Control (11-9) 4144 4145- CONFIG_SYS_TBSCR: Time Base Status and Control (11-26) 4146 4147- CONFIG_SYS_PISCR: Periodic Interrupt Status and Control (11-31) 4148 4149- CONFIG_SYS_PLPRCR: PLL, Low-Power, and Reset Control Register (15-30) 4150 4151- CONFIG_SYS_SCCR: System Clock and reset Control Register (15-27) 4152 4153- CONFIG_SYS_OR_TIMING_SDRAM: 4154 SDRAM timing 4155 4156- CONFIG_SYS_MAMR_PTA: 4157 periodic timer for refresh 4158 4159- CONFIG_SYS_DER: Debug Event Register (37-47) 4160 4161- FLASH_BASE0_PRELIM, FLASH_BASE1_PRELIM, CONFIG_SYS_REMAP_OR_AM, 4162 CONFIG_SYS_PRELIM_OR_AM, CONFIG_SYS_OR_TIMING_FLASH, CONFIG_SYS_OR0_REMAP, 4163 CONFIG_SYS_OR0_PRELIM, CONFIG_SYS_BR0_PRELIM, CONFIG_SYS_OR1_REMAP, CONFIG_SYS_OR1_PRELIM, 4164 CONFIG_SYS_BR1_PRELIM: 4165 Memory Controller Definitions: BR0/1 and OR0/1 (FLASH) 4166 4167- SDRAM_BASE2_PRELIM, SDRAM_BASE3_PRELIM, SDRAM_MAX_SIZE, 4168 CONFIG_SYS_OR_TIMING_SDRAM, CONFIG_SYS_OR2_PRELIM, CONFIG_SYS_BR2_PRELIM, 4169 CONFIG_SYS_OR3_PRELIM, CONFIG_SYS_BR3_PRELIM: 4170 Memory Controller Definitions: BR2/3 and OR2/3 (SDRAM) 4171 4172- CONFIG_SYS_MAMR_PTA, CONFIG_SYS_MPTPR_2BK_4K, CONFIG_SYS_MPTPR_1BK_4K, CONFIG_SYS_MPTPR_2BK_8K, 4173 CONFIG_SYS_MPTPR_1BK_8K, CONFIG_SYS_MAMR_8COL, CONFIG_SYS_MAMR_9COL: 4174 Machine Mode Register and Memory Periodic Timer 4175 Prescaler definitions (SDRAM timing) 4176 4177- CONFIG_SYS_I2C_UCODE_PATCH, CONFIG_SYS_I2C_DPMEM_OFFSET [0x1FC0]: 4178 enable I2C microcode relocation patch (MPC8xx); 4179 define relocation offset in DPRAM [DSP2] 4180 4181- CONFIG_SYS_SMC_UCODE_PATCH, CONFIG_SYS_SMC_DPMEM_OFFSET [0x1FC0]: 4182 enable SMC microcode relocation patch (MPC8xx); 4183 define relocation offset in DPRAM [SMC1] 4184 4185- CONFIG_SYS_SPI_UCODE_PATCH, CONFIG_SYS_SPI_DPMEM_OFFSET [0x1FC0]: 4186 enable SPI microcode relocation patch (MPC8xx); 4187 define relocation offset in DPRAM [SCC4] 4188 4189- CONFIG_SYS_CPM_POST_WORD_ADDR: (MPC8xx, MPC8260 only) 4190 Offset of the bootmode word in DPRAM used by post 4191 (Power On Self Tests). This definition overrides 4192 #define'd default value in commproc.h resp. 4193 cpm_8260.h. 4194 4195- CONFIG_SYS_PCI_SLV_MEM_LOCAL, CONFIG_SYS_PCI_SLV_MEM_BUS, CONFIG_SYS_PICMR0_MASK_ATTRIB, 4196 CONFIG_SYS_PCI_MSTR0_LOCAL, CONFIG_SYS_PCIMSK0_MASK, CONFIG_SYS_PCI_MSTR1_LOCAL, 4197 CONFIG_SYS_PCIMSK1_MASK, CONFIG_SYS_PCI_MSTR_MEM_LOCAL, CONFIG_SYS_PCI_MSTR_MEM_BUS, 4198 CONFIG_SYS_CPU_PCI_MEM_START, CONFIG_SYS_PCI_MSTR_MEM_SIZE, CONFIG_SYS_POCMR0_MASK_ATTRIB, 4199 CONFIG_SYS_PCI_MSTR_MEMIO_LOCAL, CONFIG_SYS_PCI_MSTR_MEMIO_BUS, CPU_PCI_MEMIO_START, 4200 CONFIG_SYS_PCI_MSTR_MEMIO_SIZE, CONFIG_SYS_POCMR1_MASK_ATTRIB, CONFIG_SYS_PCI_MSTR_IO_LOCAL, 4201 CONFIG_SYS_PCI_MSTR_IO_BUS, CONFIG_SYS_CPU_PCI_IO_START, CONFIG_SYS_PCI_MSTR_IO_SIZE, 4202 CONFIG_SYS_POCMR2_MASK_ATTRIB: (MPC826x only) 4203 Overrides the default PCI memory map in arch/powerpc/cpu/mpc8260/pci.c if set. 4204 4205- CONFIG_PCI_DISABLE_PCIE: 4206 Disable PCI-Express on systems where it is supported but not 4207 required. 4208 4209- CONFIG_PCI_ENUM_ONLY 4210 Only scan through and get the devices on the buses. 4211 Don't do any setup work, presumably because someone or 4212 something has already done it, and we don't need to do it 4213 a second time. Useful for platforms that are pre-booted 4214 by coreboot or similar. 4215 4216- CONFIG_PCI_INDIRECT_BRIDGE: 4217 Enable support for indirect PCI bridges. 4218 4219- CONFIG_SYS_SRIO: 4220 Chip has SRIO or not 4221 4222- CONFIG_SRIO1: 4223 Board has SRIO 1 port available 4224 4225- CONFIG_SRIO2: 4226 Board has SRIO 2 port available 4227 4228- CONFIG_SRIO_PCIE_BOOT_MASTER 4229 Board can support master function for Boot from SRIO and PCIE 4230 4231- CONFIG_SYS_SRIOn_MEM_VIRT: 4232 Virtual Address of SRIO port 'n' memory region 4233 4234- CONFIG_SYS_SRIOn_MEM_PHYS: 4235 Physical Address of SRIO port 'n' memory region 4236 4237- CONFIG_SYS_SRIOn_MEM_SIZE: 4238 Size of SRIO port 'n' memory region 4239 4240- CONFIG_SYS_NAND_BUSWIDTH_16BIT 4241 Defined to tell the NAND controller that the NAND chip is using 4242 a 16 bit bus. 4243 Not all NAND drivers use this symbol. 4244 Example of drivers that use it: 4245 - drivers/mtd/nand/ndfc.c 4246 - drivers/mtd/nand/mxc_nand.c 4247 4248- CONFIG_SYS_NDFC_EBC0_CFG 4249 Sets the EBC0_CFG register for the NDFC. If not defined 4250 a default value will be used. 4251 4252- CONFIG_SPD_EEPROM 4253 Get DDR timing information from an I2C EEPROM. Common 4254 with pluggable memory modules such as SODIMMs 4255 4256 SPD_EEPROM_ADDRESS 4257 I2C address of the SPD EEPROM 4258 4259- CONFIG_SYS_SPD_BUS_NUM 4260 If SPD EEPROM is on an I2C bus other than the first 4261 one, specify here. Note that the value must resolve 4262 to something your driver can deal with. 4263 4264- CONFIG_SYS_DDR_RAW_TIMING 4265 Get DDR timing information from other than SPD. Common with 4266 soldered DDR chips onboard without SPD. DDR raw timing 4267 parameters are extracted from datasheet and hard-coded into 4268 header files or board specific files. 4269 4270- CONFIG_FSL_DDR_INTERACTIVE 4271 Enable interactive DDR debugging. See doc/README.fsl-ddr. 4272 4273- CONFIG_FSL_DDR_SYNC_REFRESH 4274 Enable sync of refresh for multiple controllers. 4275 4276- CONFIG_FSL_DDR_BIST 4277 Enable built-in memory test for Freescale DDR controllers. 4278 4279- CONFIG_SYS_83XX_DDR_USES_CS0 4280 Only for 83xx systems. If specified, then DDR should 4281 be configured using CS0 and CS1 instead of CS2 and CS3. 4282 4283- CONFIG_ETHER_ON_FEC[12] 4284 Define to enable FEC[12] on a 8xx series processor. 4285 4286- CONFIG_FEC[12]_PHY 4287 Define to the hardcoded PHY address which corresponds 4288 to the given FEC; i. e. 4289 #define CONFIG_FEC1_PHY 4 4290 means that the PHY with address 4 is connected to FEC1 4291 4292 When set to -1, means to probe for first available. 4293 4294- CONFIG_FEC[12]_PHY_NORXERR 4295 The PHY does not have a RXERR line (RMII only). 4296 (so program the FEC to ignore it). 4297 4298- CONFIG_RMII 4299 Enable RMII mode for all FECs. 4300 Note that this is a global option, we can't 4301 have one FEC in standard MII mode and another in RMII mode. 4302 4303- CONFIG_CRC32_VERIFY 4304 Add a verify option to the crc32 command. 4305 The syntax is: 4306 4307 => crc32 -v <address> <count> <crc32> 4308 4309 Where address/count indicate a memory area 4310 and crc32 is the correct crc32 which the 4311 area should have. 4312 4313- CONFIG_LOOPW 4314 Add the "loopw" memory command. This only takes effect if 4315 the memory commands are activated globally (CONFIG_CMD_MEM). 4316 4317- CONFIG_MX_CYCLIC 4318 Add the "mdc" and "mwc" memory commands. These are cyclic 4319 "md/mw" commands. 4320 Examples: 4321 4322 => mdc.b 10 4 500 4323 This command will print 4 bytes (10,11,12,13) each 500 ms. 4324 4325 => mwc.l 100 12345678 10 4326 This command will write 12345678 to address 100 all 10 ms. 4327 4328 This only takes effect if the memory commands are activated 4329 globally (CONFIG_CMD_MEM). 4330 4331- CONFIG_SKIP_LOWLEVEL_INIT 4332 [ARM, NDS32, MIPS only] If this variable is defined, then certain 4333 low level initializations (like setting up the memory 4334 controller) are omitted and/or U-Boot does not 4335 relocate itself into RAM. 4336 4337 Normally this variable MUST NOT be defined. The only 4338 exception is when U-Boot is loaded (to RAM) by some 4339 other boot loader or by a debugger which performs 4340 these initializations itself. 4341 4342- CONFIG_SKIP_LOWLEVEL_INIT_ONLY 4343 [ARM926EJ-S only] This allows just the call to lowlevel_init() 4344 to be skipped. The normal CP15 init (such as enabling the 4345 instruction cache) is still performed. 4346 4347- CONFIG_SPL_BUILD 4348 Modifies the behaviour of start.S when compiling a loader 4349 that is executed before the actual U-Boot. E.g. when 4350 compiling a NAND SPL. 4351 4352- CONFIG_TPL_BUILD 4353 Modifies the behaviour of start.S when compiling a loader 4354 that is executed after the SPL and before the actual U-Boot. 4355 It is loaded by the SPL. 4356 4357- CONFIG_SYS_MPC85XX_NO_RESETVEC 4358 Only for 85xx systems. If this variable is specified, the section 4359 .resetvec is not kept and the section .bootpg is placed in the 4360 previous 4k of the .text section. 4361 4362- CONFIG_ARCH_MAP_SYSMEM 4363 Generally U-Boot (and in particular the md command) uses 4364 effective address. It is therefore not necessary to regard 4365 U-Boot address as virtual addresses that need to be translated 4366 to physical addresses. However, sandbox requires this, since 4367 it maintains its own little RAM buffer which contains all 4368 addressable memory. This option causes some memory accesses 4369 to be mapped through map_sysmem() / unmap_sysmem(). 4370 4371- CONFIG_X86_RESET_VECTOR 4372 If defined, the x86 reset vector code is included. This is not 4373 needed when U-Boot is running from Coreboot. 4374 4375- CONFIG_SPL_AM33XX_ENABLE_RTC32K_OSC: 4376 Enables the RTC32K OSC on AM33xx based plattforms 4377 4378- CONFIG_SYS_NAND_NO_SUBPAGE_WRITE 4379 Option to disable subpage write in NAND driver 4380 driver that uses this: 4381 drivers/mtd/nand/davinci_nand.c 4382 4383Freescale QE/FMAN Firmware Support: 4384----------------------------------- 4385 4386The Freescale QUICCEngine (QE) and Frame Manager (FMAN) both support the 4387loading of "firmware", which is encoded in the QE firmware binary format. 4388This firmware often needs to be loaded during U-Boot booting, so macros 4389are used to identify the storage device (NOR flash, SPI, etc) and the address 4390within that device. 4391 4392- CONFIG_SYS_FMAN_FW_ADDR 4393 The address in the storage device where the FMAN microcode is located. The 4394 meaning of this address depends on which CONFIG_SYS_QE_FW_IN_xxx macro 4395 is also specified. 4396 4397- CONFIG_SYS_QE_FW_ADDR 4398 The address in the storage device where the QE microcode is located. The 4399 meaning of this address depends on which CONFIG_SYS_QE_FW_IN_xxx macro 4400 is also specified. 4401 4402- CONFIG_SYS_QE_FMAN_FW_LENGTH 4403 The maximum possible size of the firmware. The firmware binary format 4404 has a field that specifies the actual size of the firmware, but it 4405 might not be possible to read any part of the firmware unless some 4406 local storage is allocated to hold the entire firmware first. 4407 4408- CONFIG_SYS_QE_FMAN_FW_IN_NOR 4409 Specifies that QE/FMAN firmware is located in NOR flash, mapped as 4410 normal addressable memory via the LBC. CONFIG_SYS_FMAN_FW_ADDR is the 4411 virtual address in NOR flash. 4412 4413- CONFIG_SYS_QE_FMAN_FW_IN_NAND 4414 Specifies that QE/FMAN firmware is located in NAND flash. 4415 CONFIG_SYS_FMAN_FW_ADDR is the offset within NAND flash. 4416 4417- CONFIG_SYS_QE_FMAN_FW_IN_MMC 4418 Specifies that QE/FMAN firmware is located on the primary SD/MMC 4419 device. CONFIG_SYS_FMAN_FW_ADDR is the byte offset on that device. 4420 4421- CONFIG_SYS_QE_FMAN_FW_IN_REMOTE 4422 Specifies that QE/FMAN firmware is located in the remote (master) 4423 memory space. CONFIG_SYS_FMAN_FW_ADDR is a virtual address which 4424 can be mapped from slave TLB->slave LAW->slave SRIO or PCIE outbound 4425 window->master inbound window->master LAW->the ucode address in 4426 master's memory space. 4427 4428Freescale Layerscape Management Complex Firmware Support: 4429--------------------------------------------------------- 4430The Freescale Layerscape Management Complex (MC) supports the loading of 4431"firmware". 4432This firmware often needs to be loaded during U-Boot booting, so macros 4433are used to identify the storage device (NOR flash, SPI, etc) and the address 4434within that device. 4435 4436- CONFIG_FSL_MC_ENET 4437 Enable the MC driver for Layerscape SoCs. 4438 4439Freescale Layerscape Debug Server Support: 4440------------------------------------------- 4441The Freescale Layerscape Debug Server Support supports the loading of 4442"Debug Server firmware" and triggering SP boot-rom. 4443This firmware often needs to be loaded during U-Boot booting. 4444 4445- CONFIG_SYS_MC_RSV_MEM_ALIGN 4446 Define alignment of reserved memory MC requires 4447 4448Reproducible builds 4449------------------- 4450 4451In order to achieve reproducible builds, timestamps used in the U-Boot build 4452process have to be set to a fixed value. 4453 4454This is done using the SOURCE_DATE_EPOCH environment variable. 4455SOURCE_DATE_EPOCH is to be set on the build host's shell, not as a configuration 4456option for U-Boot or an environment variable in U-Boot. 4457 4458SOURCE_DATE_EPOCH should be set to a number of seconds since the epoch, in UTC. 4459 4460Building the Software: 4461====================== 4462 4463Building U-Boot has been tested in several native build environments 4464and in many different cross environments. Of course we cannot support 4465all possibly existing versions of cross development tools in all 4466(potentially obsolete) versions. In case of tool chain problems we 4467recommend to use the ELDK (see http://www.denx.de/wiki/DULG/ELDK) 4468which is extensively used to build and test U-Boot. 4469 4470If you are not using a native environment, it is assumed that you 4471have GNU cross compiling tools available in your path. In this case, 4472you must set the environment variable CROSS_COMPILE in your shell. 4473Note that no changes to the Makefile or any other source files are 4474necessary. For example using the ELDK on a 4xx CPU, please enter: 4475 4476 $ CROSS_COMPILE=ppc_4xx- 4477 $ export CROSS_COMPILE 4478 4479Note: If you wish to generate Windows versions of the utilities in 4480 the tools directory you can use the MinGW toolchain 4481 (http://www.mingw.org). Set your HOST tools to the MinGW 4482 toolchain and execute 'make tools'. For example: 4483 4484 $ make HOSTCC=i586-mingw32msvc-gcc HOSTSTRIP=i586-mingw32msvc-strip tools 4485 4486 Binaries such as tools/mkimage.exe will be created which can 4487 be executed on computers running Windows. 4488 4489U-Boot is intended to be simple to build. After installing the 4490sources you must configure U-Boot for one specific board type. This 4491is done by typing: 4492 4493 make NAME_defconfig 4494 4495where "NAME_defconfig" is the name of one of the existing configu- 4496rations; see boards.cfg for supported names. 4497 4498Note: for some board special configuration names may exist; check if 4499 additional information is available from the board vendor; for 4500 instance, the TQM823L systems are available without (standard) 4501 or with LCD support. You can select such additional "features" 4502 when choosing the configuration, i. e. 4503 4504 make TQM823L_defconfig 4505 - will configure for a plain TQM823L, i. e. no LCD support 4506 4507 make TQM823L_LCD_defconfig 4508 - will configure for a TQM823L with U-Boot console on LCD 4509 4510 etc. 4511 4512 4513Finally, type "make all", and you should get some working U-Boot 4514images ready for download to / installation on your system: 4515 4516- "u-boot.bin" is a raw binary image 4517- "u-boot" is an image in ELF binary format 4518- "u-boot.srec" is in Motorola S-Record format 4519 4520By default the build is performed locally and the objects are saved 4521in the source directory. One of the two methods can be used to change 4522this behavior and build U-Boot to some external directory: 4523 45241. Add O= to the make command line invocations: 4525 4526 make O=/tmp/build distclean 4527 make O=/tmp/build NAME_defconfig 4528 make O=/tmp/build all 4529 45302. Set environment variable KBUILD_OUTPUT to point to the desired location: 4531 4532 export KBUILD_OUTPUT=/tmp/build 4533 make distclean 4534 make NAME_defconfig 4535 make all 4536 4537Note that the command line "O=" setting overrides the KBUILD_OUTPUT environment 4538variable. 4539 4540 4541Please be aware that the Makefiles assume you are using GNU make, so 4542for instance on NetBSD you might need to use "gmake" instead of 4543native "make". 4544 4545 4546If the system board that you have is not listed, then you will need 4547to port U-Boot to your hardware platform. To do this, follow these 4548steps: 4549 45501. Create a new directory to hold your board specific code. Add any 4551 files you need. In your board directory, you will need at least 4552 the "Makefile" and a "<board>.c". 45532. Create a new configuration file "include/configs/<board>.h" for 4554 your board. 45553. If you're porting U-Boot to a new CPU, then also create a new 4556 directory to hold your CPU specific code. Add any files you need. 45574. Run "make <board>_defconfig" with your new name. 45585. Type "make", and you should get a working "u-boot.srec" file 4559 to be installed on your target system. 45606. Debug and solve any problems that might arise. 4561 [Of course, this last step is much harder than it sounds.] 4562 4563 4564Testing of U-Boot Modifications, Ports to New Hardware, etc.: 4565============================================================== 4566 4567If you have modified U-Boot sources (for instance added a new board 4568or support for new devices, a new CPU, etc.) you are expected to 4569provide feedback to the other developers. The feedback normally takes 4570the form of a "patch", i. e. a context diff against a certain (latest 4571official or latest in the git repository) version of U-Boot sources. 4572 4573But before you submit such a patch, please verify that your modifi- 4574cation did not break existing code. At least make sure that *ALL* of 4575the supported boards compile WITHOUT ANY compiler warnings. To do so, 4576just run the buildman script (tools/buildman/buildman), which will 4577configure and build U-Boot for ALL supported system. Be warned, this 4578will take a while. Please see the buildman README, or run 'buildman -H' 4579for documentation. 4580 4581 4582See also "U-Boot Porting Guide" below. 4583 4584 4585Monitor Commands - Overview: 4586============================ 4587 4588go - start application at address 'addr' 4589run - run commands in an environment variable 4590bootm - boot application image from memory 4591bootp - boot image via network using BootP/TFTP protocol 4592bootz - boot zImage from memory 4593tftpboot- boot image via network using TFTP protocol 4594 and env variables "ipaddr" and "serverip" 4595 (and eventually "gatewayip") 4596tftpput - upload a file via network using TFTP protocol 4597rarpboot- boot image via network using RARP/TFTP protocol 4598diskboot- boot from IDE devicebootd - boot default, i.e., run 'bootcmd' 4599loads - load S-Record file over serial line 4600loadb - load binary file over serial line (kermit mode) 4601md - memory display 4602mm - memory modify (auto-incrementing) 4603nm - memory modify (constant address) 4604mw - memory write (fill) 4605cp - memory copy 4606cmp - memory compare 4607crc32 - checksum calculation 4608i2c - I2C sub-system 4609sspi - SPI utility commands 4610base - print or set address offset 4611printenv- print environment variables 4612setenv - set environment variables 4613saveenv - save environment variables to persistent storage 4614protect - enable or disable FLASH write protection 4615erase - erase FLASH memory 4616flinfo - print FLASH memory information 4617nand - NAND memory operations (see doc/README.nand) 4618bdinfo - print Board Info structure 4619iminfo - print header information for application image 4620coninfo - print console devices and informations 4621ide - IDE sub-system 4622loop - infinite loop on address range 4623loopw - infinite write loop on address range 4624mtest - simple RAM test 4625icache - enable or disable instruction cache 4626dcache - enable or disable data cache 4627reset - Perform RESET of the CPU 4628echo - echo args to console 4629version - print monitor version 4630help - print online help 4631? - alias for 'help' 4632 4633 4634Monitor Commands - Detailed Description: 4635======================================== 4636 4637TODO. 4638 4639For now: just type "help <command>". 4640 4641 4642Environment Variables: 4643====================== 4644 4645U-Boot supports user configuration using Environment Variables which 4646can be made persistent by saving to Flash memory. 4647 4648Environment Variables are set using "setenv", printed using 4649"printenv", and saved to Flash using "saveenv". Using "setenv" 4650without a value can be used to delete a variable from the 4651environment. As long as you don't save the environment you are 4652working with an in-memory copy. In case the Flash area containing the 4653environment is erased by accident, a default environment is provided. 4654 4655Some configuration options can be set using Environment Variables. 4656 4657List of environment variables (most likely not complete): 4658 4659 baudrate - see CONFIG_BAUDRATE 4660 4661 bootdelay - see CONFIG_BOOTDELAY 4662 4663 bootcmd - see CONFIG_BOOTCOMMAND 4664 4665 bootargs - Boot arguments when booting an RTOS image 4666 4667 bootfile - Name of the image to load with TFTP 4668 4669 bootm_low - Memory range available for image processing in the bootm 4670 command can be restricted. This variable is given as 4671 a hexadecimal number and defines lowest address allowed 4672 for use by the bootm command. See also "bootm_size" 4673 environment variable. Address defined by "bootm_low" is 4674 also the base of the initial memory mapping for the Linux 4675 kernel -- see the description of CONFIG_SYS_BOOTMAPSZ and 4676 bootm_mapsize. 4677 4678 bootm_mapsize - Size of the initial memory mapping for the Linux kernel. 4679 This variable is given as a hexadecimal number and it 4680 defines the size of the memory region starting at base 4681 address bootm_low that is accessible by the Linux kernel 4682 during early boot. If unset, CONFIG_SYS_BOOTMAPSZ is used 4683 as the default value if it is defined, and bootm_size is 4684 used otherwise. 4685 4686 bootm_size - Memory range available for image processing in the bootm 4687 command can be restricted. This variable is given as 4688 a hexadecimal number and defines the size of the region 4689 allowed for use by the bootm command. See also "bootm_low" 4690 environment variable. 4691 4692 updatefile - Location of the software update file on a TFTP server, used 4693 by the automatic software update feature. Please refer to 4694 documentation in doc/README.update for more details. 4695 4696 autoload - if set to "no" (any string beginning with 'n'), 4697 "bootp" will just load perform a lookup of the 4698 configuration from the BOOTP server, but not try to 4699 load any image using TFTP 4700 4701 autostart - if set to "yes", an image loaded using the "bootp", 4702 "rarpboot", "tftpboot" or "diskboot" commands will 4703 be automatically started (by internally calling 4704 "bootm") 4705 4706 If set to "no", a standalone image passed to the 4707 "bootm" command will be copied to the load address 4708 (and eventually uncompressed), but NOT be started. 4709 This can be used to load and uncompress arbitrary 4710 data. 4711 4712 fdt_high - if set this restricts the maximum address that the 4713 flattened device tree will be copied into upon boot. 4714 For example, if you have a system with 1 GB memory 4715 at physical address 0x10000000, while Linux kernel 4716 only recognizes the first 704 MB as low memory, you 4717 may need to set fdt_high as 0x3C000000 to have the 4718 device tree blob be copied to the maximum address 4719 of the 704 MB low memory, so that Linux kernel can 4720 access it during the boot procedure. 4721 4722 If this is set to the special value 0xFFFFFFFF then 4723 the fdt will not be copied at all on boot. For this 4724 to work it must reside in writable memory, have 4725 sufficient padding on the end of it for u-boot to 4726 add the information it needs into it, and the memory 4727 must be accessible by the kernel. 4728 4729 fdtcontroladdr- if set this is the address of the control flattened 4730 device tree used by U-Boot when CONFIG_OF_CONTROL is 4731 defined. 4732 4733 i2cfast - (PPC405GP|PPC405EP only) 4734 if set to 'y' configures Linux I2C driver for fast 4735 mode (400kHZ). This environment variable is used in 4736 initialization code. So, for changes to be effective 4737 it must be saved and board must be reset. 4738 4739 initrd_high - restrict positioning of initrd images: 4740 If this variable is not set, initrd images will be 4741 copied to the highest possible address in RAM; this 4742 is usually what you want since it allows for 4743 maximum initrd size. If for some reason you want to 4744 make sure that the initrd image is loaded below the 4745 CONFIG_SYS_BOOTMAPSZ limit, you can set this environment 4746 variable to a value of "no" or "off" or "0". 4747 Alternatively, you can set it to a maximum upper 4748 address to use (U-Boot will still check that it 4749 does not overwrite the U-Boot stack and data). 4750 4751 For instance, when you have a system with 16 MB 4752 RAM, and want to reserve 4 MB from use by Linux, 4753 you can do this by adding "mem=12M" to the value of 4754 the "bootargs" variable. However, now you must make 4755 sure that the initrd image is placed in the first 4756 12 MB as well - this can be done with 4757 4758 setenv initrd_high 00c00000 4759 4760 If you set initrd_high to 0xFFFFFFFF, this is an 4761 indication to U-Boot that all addresses are legal 4762 for the Linux kernel, including addresses in flash 4763 memory. In this case U-Boot will NOT COPY the 4764 ramdisk at all. This may be useful to reduce the 4765 boot time on your system, but requires that this 4766 feature is supported by your Linux kernel. 4767 4768 ipaddr - IP address; needed for tftpboot command 4769 4770 loadaddr - Default load address for commands like "bootp", 4771 "rarpboot", "tftpboot", "loadb" or "diskboot" 4772 4773 loads_echo - see CONFIG_LOADS_ECHO 4774 4775 serverip - TFTP server IP address; needed for tftpboot command 4776 4777 bootretry - see CONFIG_BOOT_RETRY_TIME 4778 4779 bootdelaykey - see CONFIG_AUTOBOOT_DELAY_STR 4780 4781 bootstopkey - see CONFIG_AUTOBOOT_STOP_STR 4782 4783 ethprime - controls which interface is used first. 4784 4785 ethact - controls which interface is currently active. 4786 For example you can do the following 4787 4788 => setenv ethact FEC 4789 => ping 192.168.0.1 # traffic sent on FEC 4790 => setenv ethact SCC 4791 => ping 10.0.0.1 # traffic sent on SCC 4792 4793 ethrotate - When set to "no" U-Boot does not go through all 4794 available network interfaces. 4795 It just stays at the currently selected interface. 4796 4797 netretry - When set to "no" each network operation will 4798 either succeed or fail without retrying. 4799 When set to "once" the network operation will 4800 fail when all the available network interfaces 4801 are tried once without success. 4802 Useful on scripts which control the retry operation 4803 themselves. 4804 4805 npe_ucode - set load address for the NPE microcode 4806 4807 silent_linux - If set then Linux will be told to boot silently, by 4808 changing the console to be empty. If "yes" it will be 4809 made silent. If "no" it will not be made silent. If 4810 unset, then it will be made silent if the U-Boot console 4811 is silent. 4812 4813 tftpsrcp - If this is set, the value is used for TFTP's 4814 UDP source port. 4815 4816 tftpdstp - If this is set, the value is used for TFTP's UDP 4817 destination port instead of the Well Know Port 69. 4818 4819 tftpblocksize - Block size to use for TFTP transfers; if not set, 4820 we use the TFTP server's default block size 4821 4822 tftptimeout - Retransmission timeout for TFTP packets (in milli- 4823 seconds, minimum value is 1000 = 1 second). Defines 4824 when a packet is considered to be lost so it has to 4825 be retransmitted. The default is 5000 = 5 seconds. 4826 Lowering this value may make downloads succeed 4827 faster in networks with high packet loss rates or 4828 with unreliable TFTP servers. 4829 4830 tftptimeoutcountmax - maximum count of TFTP timeouts (no 4831 unit, minimum value = 0). Defines how many timeouts 4832 can happen during a single file transfer before that 4833 transfer is aborted. The default is 10, and 0 means 4834 'no timeouts allowed'. Increasing this value may help 4835 downloads succeed with high packet loss rates, or with 4836 unreliable TFTP servers or client hardware. 4837 4838 vlan - When set to a value < 4095 the traffic over 4839 Ethernet is encapsulated/received over 802.1q 4840 VLAN tagged frames. 4841 4842 bootpretryperiod - Period during which BOOTP/DHCP sends retries. 4843 Unsigned value, in milliseconds. If not set, the period will 4844 be either the default (28000), or a value based on 4845 CONFIG_NET_RETRY_COUNT, if defined. This value has 4846 precedence over the valu based on CONFIG_NET_RETRY_COUNT. 4847 4848The following image location variables contain the location of images 4849used in booting. The "Image" column gives the role of the image and is 4850not an environment variable name. The other columns are environment 4851variable names. "File Name" gives the name of the file on a TFTP 4852server, "RAM Address" gives the location in RAM the image will be 4853loaded to, and "Flash Location" gives the image's address in NOR 4854flash or offset in NAND flash. 4855 4856*Note* - these variables don't have to be defined for all boards, some 4857boards currently use other variables for these purposes, and some 4858boards use these variables for other purposes. 4859 4860Image File Name RAM Address Flash Location 4861----- --------- ----------- -------------- 4862u-boot u-boot u-boot_addr_r u-boot_addr 4863Linux kernel bootfile kernel_addr_r kernel_addr 4864device tree blob fdtfile fdt_addr_r fdt_addr 4865ramdisk ramdiskfile ramdisk_addr_r ramdisk_addr 4866 4867The following environment variables may be used and automatically 4868updated by the network boot commands ("bootp" and "rarpboot"), 4869depending the information provided by your boot server: 4870 4871 bootfile - see above 4872 dnsip - IP address of your Domain Name Server 4873 dnsip2 - IP address of your secondary Domain Name Server 4874 gatewayip - IP address of the Gateway (Router) to use 4875 hostname - Target hostname 4876 ipaddr - see above 4877 netmask - Subnet Mask 4878 rootpath - Pathname of the root filesystem on the NFS server 4879 serverip - see above 4880 4881 4882There are two special Environment Variables: 4883 4884 serial# - contains hardware identification information such 4885 as type string and/or serial number 4886 ethaddr - Ethernet address 4887 4888These variables can be set only once (usually during manufacturing of 4889the board). U-Boot refuses to delete or overwrite these variables 4890once they have been set once. 4891 4892 4893Further special Environment Variables: 4894 4895 ver - Contains the U-Boot version string as printed 4896 with the "version" command. This variable is 4897 readonly (see CONFIG_VERSION_VARIABLE). 4898 4899 4900Please note that changes to some configuration parameters may take 4901only effect after the next boot (yes, that's just like Windoze :-). 4902 4903 4904Callback functions for environment variables: 4905--------------------------------------------- 4906 4907For some environment variables, the behavior of u-boot needs to change 4908when their values are changed. This functionality allows functions to 4909be associated with arbitrary variables. On creation, overwrite, or 4910deletion, the callback will provide the opportunity for some side 4911effect to happen or for the change to be rejected. 4912 4913The callbacks are named and associated with a function using the 4914U_BOOT_ENV_CALLBACK macro in your board or driver code. 4915 4916These callbacks are associated with variables in one of two ways. The 4917static list can be added to by defining CONFIG_ENV_CALLBACK_LIST_STATIC 4918in the board configuration to a string that defines a list of 4919associations. The list must be in the following format: 4920 4921 entry = variable_name[:callback_name] 4922 list = entry[,list] 4923 4924If the callback name is not specified, then the callback is deleted. 4925Spaces are also allowed anywhere in the list. 4926 4927Callbacks can also be associated by defining the ".callbacks" variable 4928with the same list format above. Any association in ".callbacks" will 4929override any association in the static list. You can define 4930CONFIG_ENV_CALLBACK_LIST_DEFAULT to a list (string) to define the 4931".callbacks" environment variable in the default or embedded environment. 4932 4933If CONFIG_REGEX is defined, the variable_name above is evaluated as a 4934regular expression. This allows multiple variables to be connected to 4935the same callback without explicitly listing them all out. 4936 4937 4938Command Line Parsing: 4939===================== 4940 4941There are two different command line parsers available with U-Boot: 4942the old "simple" one, and the much more powerful "hush" shell: 4943 4944Old, simple command line parser: 4945-------------------------------- 4946 4947- supports environment variables (through setenv / saveenv commands) 4948- several commands on one line, separated by ';' 4949- variable substitution using "... ${name} ..." syntax 4950- special characters ('$', ';') can be escaped by prefixing with '\', 4951 for example: 4952 setenv bootcmd bootm \${address} 4953- You can also escape text by enclosing in single apostrophes, for example: 4954 setenv addip 'setenv bootargs $bootargs ip=$ipaddr:$serverip:$gatewayip:$netmask:$hostname::off' 4955 4956Hush shell: 4957----------- 4958 4959- similar to Bourne shell, with control structures like 4960 if...then...else...fi, for...do...done; while...do...done, 4961 until...do...done, ... 4962- supports environment ("global") variables (through setenv / saveenv 4963 commands) and local shell variables (through standard shell syntax 4964 "name=value"); only environment variables can be used with "run" 4965 command 4966 4967General rules: 4968-------------- 4969 4970(1) If a command line (or an environment variable executed by a "run" 4971 command) contains several commands separated by semicolon, and 4972 one of these commands fails, then the remaining commands will be 4973 executed anyway. 4974 4975(2) If you execute several variables with one call to run (i. e. 4976 calling run with a list of variables as arguments), any failing 4977 command will cause "run" to terminate, i. e. the remaining 4978 variables are not executed. 4979 4980Note for Redundant Ethernet Interfaces: 4981======================================= 4982 4983Some boards come with redundant Ethernet interfaces; U-Boot supports 4984such configurations and is capable of automatic selection of a 4985"working" interface when needed. MAC assignment works as follows: 4986 4987Network interfaces are numbered eth0, eth1, eth2, ... Corresponding 4988MAC addresses can be stored in the environment as "ethaddr" (=>eth0), 4989"eth1addr" (=>eth1), "eth2addr", ... 4990 4991If the network interface stores some valid MAC address (for instance 4992in SROM), this is used as default address if there is NO correspon- 4993ding setting in the environment; if the corresponding environment 4994variable is set, this overrides the settings in the card; that means: 4995 4996o If the SROM has a valid MAC address, and there is no address in the 4997 environment, the SROM's address is used. 4998 4999o If there is no valid address in the SROM, and a definition in the 5000 environment exists, then the value from the environment variable is 5001 used. 5002 5003o If both the SROM and the environment contain a MAC address, and 5004 both addresses are the same, this MAC address is used. 5005 5006o If both the SROM and the environment contain a MAC address, and the 5007 addresses differ, the value from the environment is used and a 5008 warning is printed. 5009 5010o If neither SROM nor the environment contain a MAC address, an error 5011 is raised. If CONFIG_NET_RANDOM_ETHADDR is defined, then in this case 5012 a random, locally-assigned MAC is used. 5013 5014If Ethernet drivers implement the 'write_hwaddr' function, valid MAC addresses 5015will be programmed into hardware as part of the initialization process. This 5016may be skipped by setting the appropriate 'ethmacskip' environment variable. 5017The naming convention is as follows: 5018"ethmacskip" (=>eth0), "eth1macskip" (=>eth1) etc. 5019 5020Image Formats: 5021============== 5022 5023U-Boot is capable of booting (and performing other auxiliary operations on) 5024images in two formats: 5025 5026New uImage format (FIT) 5027----------------------- 5028 5029Flexible and powerful format based on Flattened Image Tree -- FIT (similar 5030to Flattened Device Tree). It allows the use of images with multiple 5031components (several kernels, ramdisks, etc.), with contents protected by 5032SHA1, MD5 or CRC32. More details are found in the doc/uImage.FIT directory. 5033 5034 5035Old uImage format 5036----------------- 5037 5038Old image format is based on binary files which can be basically anything, 5039preceded by a special header; see the definitions in include/image.h for 5040details; basically, the header defines the following image properties: 5041 5042* Target Operating System (Provisions for OpenBSD, NetBSD, FreeBSD, 5043 4.4BSD, Linux, SVR4, Esix, Solaris, Irix, SCO, Dell, NCR, VxWorks, 5044 LynxOS, pSOS, QNX, RTEMS, INTEGRITY; 5045 Currently supported: Linux, NetBSD, VxWorks, QNX, RTEMS, LynxOS, 5046 INTEGRITY). 5047* Target CPU Architecture (Provisions for Alpha, ARM, AVR32, Intel x86, 5048 IA64, MIPS, NDS32, Nios II, PowerPC, IBM S390, SuperH, Sparc, Sparc 64 Bit; 5049 Currently supported: ARM, AVR32, Intel x86, MIPS, NDS32, Nios II, PowerPC). 5050* Compression Type (uncompressed, gzip, bzip2) 5051* Load Address 5052* Entry Point 5053* Image Name 5054* Image Timestamp 5055 5056The header is marked by a special Magic Number, and both the header 5057and the data portions of the image are secured against corruption by 5058CRC32 checksums. 5059 5060 5061Linux Support: 5062============== 5063 5064Although U-Boot should support any OS or standalone application 5065easily, the main focus has always been on Linux during the design of 5066U-Boot. 5067 5068U-Boot includes many features that so far have been part of some 5069special "boot loader" code within the Linux kernel. Also, any 5070"initrd" images to be used are no longer part of one big Linux image; 5071instead, kernel and "initrd" are separate images. This implementation 5072serves several purposes: 5073 5074- the same features can be used for other OS or standalone 5075 applications (for instance: using compressed images to reduce the 5076 Flash memory footprint) 5077 5078- it becomes much easier to port new Linux kernel versions because 5079 lots of low-level, hardware dependent stuff are done by U-Boot 5080 5081- the same Linux kernel image can now be used with different "initrd" 5082 images; of course this also means that different kernel images can 5083 be run with the same "initrd". This makes testing easier (you don't 5084 have to build a new "zImage.initrd" Linux image when you just 5085 change a file in your "initrd"). Also, a field-upgrade of the 5086 software is easier now. 5087 5088 5089Linux HOWTO: 5090============ 5091 5092Porting Linux to U-Boot based systems: 5093--------------------------------------- 5094 5095U-Boot cannot save you from doing all the necessary modifications to 5096configure the Linux device drivers for use with your target hardware 5097(no, we don't intend to provide a full virtual machine interface to 5098Linux :-). 5099 5100But now you can ignore ALL boot loader code (in arch/powerpc/mbxboot). 5101 5102Just make sure your machine specific header file (for instance 5103include/asm-ppc/tqm8xx.h) includes the same definition of the Board 5104Information structure as we define in include/asm-<arch>/u-boot.h, 5105and make sure that your definition of IMAP_ADDR uses the same value 5106as your U-Boot configuration in CONFIG_SYS_IMMR. 5107 5108Note that U-Boot now has a driver model, a unified model for drivers. 5109If you are adding a new driver, plumb it into driver model. If there 5110is no uclass available, you are encouraged to create one. See 5111doc/driver-model. 5112 5113 5114Configuring the Linux kernel: 5115----------------------------- 5116 5117No specific requirements for U-Boot. Make sure you have some root 5118device (initial ramdisk, NFS) for your target system. 5119 5120 5121Building a Linux Image: 5122----------------------- 5123 5124With U-Boot, "normal" build targets like "zImage" or "bzImage" are 5125not used. If you use recent kernel source, a new build target 5126"uImage" will exist which automatically builds an image usable by 5127U-Boot. Most older kernels also have support for a "pImage" target, 5128which was introduced for our predecessor project PPCBoot and uses a 5129100% compatible format. 5130 5131Example: 5132 5133 make TQM850L_defconfig 5134 make oldconfig 5135 make dep 5136 make uImage 5137 5138The "uImage" build target uses a special tool (in 'tools/mkimage') to 5139encapsulate a compressed Linux kernel image with header information, 5140CRC32 checksum etc. for use with U-Boot. This is what we are doing: 5141 5142* build a standard "vmlinux" kernel image (in ELF binary format): 5143 5144* convert the kernel into a raw binary image: 5145 5146 ${CROSS_COMPILE}-objcopy -O binary \ 5147 -R .note -R .comment \ 5148 -S vmlinux linux.bin 5149 5150* compress the binary image: 5151 5152 gzip -9 linux.bin 5153 5154* package compressed binary image for U-Boot: 5155 5156 mkimage -A ppc -O linux -T kernel -C gzip \ 5157 -a 0 -e 0 -n "Linux Kernel Image" \ 5158 -d linux.bin.gz uImage 5159 5160 5161The "mkimage" tool can also be used to create ramdisk images for use 5162with U-Boot, either separated from the Linux kernel image, or 5163combined into one file. "mkimage" encapsulates the images with a 64 5164byte header containing information about target architecture, 5165operating system, image type, compression method, entry points, time 5166stamp, CRC32 checksums, etc. 5167 5168"mkimage" can be called in two ways: to verify existing images and 5169print the header information, or to build new images. 5170 5171In the first form (with "-l" option) mkimage lists the information 5172contained in the header of an existing U-Boot image; this includes 5173checksum verification: 5174 5175 tools/mkimage -l image 5176 -l ==> list image header information 5177 5178The second form (with "-d" option) is used to build a U-Boot image 5179from a "data file" which is used as image payload: 5180 5181 tools/mkimage -A arch -O os -T type -C comp -a addr -e ep \ 5182 -n name -d data_file image 5183 -A ==> set architecture to 'arch' 5184 -O ==> set operating system to 'os' 5185 -T ==> set image type to 'type' 5186 -C ==> set compression type 'comp' 5187 -a ==> set load address to 'addr' (hex) 5188 -e ==> set entry point to 'ep' (hex) 5189 -n ==> set image name to 'name' 5190 -d ==> use image data from 'datafile' 5191 5192Right now, all Linux kernels for PowerPC systems use the same load 5193address (0x00000000), but the entry point address depends on the 5194kernel version: 5195 5196- 2.2.x kernels have the entry point at 0x0000000C, 5197- 2.3.x and later kernels have the entry point at 0x00000000. 5198 5199So a typical call to build a U-Boot image would read: 5200 5201 -> tools/mkimage -n '2.4.4 kernel for TQM850L' \ 5202 > -A ppc -O linux -T kernel -C gzip -a 0 -e 0 \ 5203 > -d /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/powerpc/coffboot/vmlinux.gz \ 5204 > examples/uImage.TQM850L 5205 Image Name: 2.4.4 kernel for TQM850L 5206 Created: Wed Jul 19 02:34:59 2000 5207 Image Type: PowerPC Linux Kernel Image (gzip compressed) 5208 Data Size: 335725 Bytes = 327.86 kB = 0.32 MB 5209 Load Address: 0x00000000 5210 Entry Point: 0x00000000 5211 5212To verify the contents of the image (or check for corruption): 5213 5214 -> tools/mkimage -l examples/uImage.TQM850L 5215 Image Name: 2.4.4 kernel for TQM850L 5216 Created: Wed Jul 19 02:34:59 2000 5217 Image Type: PowerPC Linux Kernel Image (gzip compressed) 5218 Data Size: 335725 Bytes = 327.86 kB = 0.32 MB 5219 Load Address: 0x00000000 5220 Entry Point: 0x00000000 5221 5222NOTE: for embedded systems where boot time is critical you can trade 5223speed for memory and install an UNCOMPRESSED image instead: this 5224needs more space in Flash, but boots much faster since it does not 5225need to be uncompressed: 5226 5227 -> gunzip /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/powerpc/coffboot/vmlinux.gz 5228 -> tools/mkimage -n '2.4.4 kernel for TQM850L' \ 5229 > -A ppc -O linux -T kernel -C none -a 0 -e 0 \ 5230 > -d /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/powerpc/coffboot/vmlinux \ 5231 > examples/uImage.TQM850L-uncompressed 5232 Image Name: 2.4.4 kernel for TQM850L 5233 Created: Wed Jul 19 02:34:59 2000 5234 Image Type: PowerPC Linux Kernel Image (uncompressed) 5235 Data Size: 792160 Bytes = 773.59 kB = 0.76 MB 5236 Load Address: 0x00000000 5237 Entry Point: 0x00000000 5238 5239 5240Similar you can build U-Boot images from a 'ramdisk.image.gz' file 5241when your kernel is intended to use an initial ramdisk: 5242 5243 -> tools/mkimage -n 'Simple Ramdisk Image' \ 5244 > -A ppc -O linux -T ramdisk -C gzip \ 5245 > -d /LinuxPPC/images/SIMPLE-ramdisk.image.gz examples/simple-initrd 5246 Image Name: Simple Ramdisk Image 5247 Created: Wed Jan 12 14:01:50 2000 5248 Image Type: PowerPC Linux RAMDisk Image (gzip compressed) 5249 Data Size: 566530 Bytes = 553.25 kB = 0.54 MB 5250 Load Address: 0x00000000 5251 Entry Point: 0x00000000 5252 5253The "dumpimage" is a tool to disassemble images built by mkimage. Its "-i" 5254option performs the converse operation of the mkimage's second form (the "-d" 5255option). Given an image built by mkimage, the dumpimage extracts a "data file" 5256from the image: 5257 5258 tools/dumpimage -i image -T type -p position data_file 5259 -i ==> extract from the 'image' a specific 'data_file' 5260 -T ==> set image type to 'type' 5261 -p ==> 'position' (starting at 0) of the 'data_file' inside the 'image' 5262 5263 5264Installing a Linux Image: 5265------------------------- 5266 5267To downloading a U-Boot image over the serial (console) interface, 5268you must convert the image to S-Record format: 5269 5270 objcopy -I binary -O srec examples/image examples/image.srec 5271 5272The 'objcopy' does not understand the information in the U-Boot 5273image header, so the resulting S-Record file will be relative to 5274address 0x00000000. To load it to a given address, you need to 5275specify the target address as 'offset' parameter with the 'loads' 5276command. 5277 5278Example: install the image to address 0x40100000 (which on the 5279TQM8xxL is in the first Flash bank): 5280 5281 => erase 40100000 401FFFFF 5282 5283 .......... done 5284 Erased 8 sectors 5285 5286 => loads 40100000 5287 ## Ready for S-Record download ... 5288 ~>examples/image.srec 5289 1 2 3 4 5 6 7 8 9 10 11 12 13 ... 5290 ... 5291 15989 15990 15991 15992 5292 [file transfer complete] 5293 [connected] 5294 ## Start Addr = 0x00000000 5295 5296 5297You can check the success of the download using the 'iminfo' command; 5298this includes a checksum verification so you can be sure no data 5299corruption happened: 5300 5301 => imi 40100000 5302 5303 ## Checking Image at 40100000 ... 5304 Image Name: 2.2.13 for initrd on TQM850L 5305 Image Type: PowerPC Linux Kernel Image (gzip compressed) 5306 Data Size: 335725 Bytes = 327 kB = 0 MB 5307 Load Address: 00000000 5308 Entry Point: 0000000c 5309 Verifying Checksum ... OK 5310 5311 5312Boot Linux: 5313----------- 5314 5315The "bootm" command is used to boot an application that is stored in 5316memory (RAM or Flash). In case of a Linux kernel image, the contents 5317of the "bootargs" environment variable is passed to the kernel as 5318parameters. You can check and modify this variable using the 5319"printenv" and "setenv" commands: 5320 5321 5322 => printenv bootargs 5323 bootargs=root=/dev/ram 5324 5325 => setenv bootargs root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2 5326 5327 => printenv bootargs 5328 bootargs=root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2 5329 5330 => bootm 40020000 5331 ## Booting Linux kernel at 40020000 ... 5332 Image Name: 2.2.13 for NFS on TQM850L 5333 Image Type: PowerPC Linux Kernel Image (gzip compressed) 5334 Data Size: 381681 Bytes = 372 kB = 0 MB 5335 Load Address: 00000000 5336 Entry Point: 0000000c 5337 Verifying Checksum ... OK 5338 Uncompressing Kernel Image ... OK 5339 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 5340 Boot arguments: root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2 5341 time_init: decrementer frequency = 187500000/60 5342 Calibrating delay loop... 49.77 BogoMIPS 5343 Memory: 15208k available (700k kernel code, 444k data, 32k init) [c0000000,c1000000] 5344 ... 5345 5346If you want to boot a Linux kernel with initial RAM disk, you pass 5347the memory addresses of both the kernel and the initrd image (PPBCOOT 5348format!) to the "bootm" command: 5349 5350 => imi 40100000 40200000 5351 5352 ## Checking Image at 40100000 ... 5353 Image Name: 2.2.13 for initrd on TQM850L 5354 Image Type: PowerPC Linux Kernel Image (gzip compressed) 5355 Data Size: 335725 Bytes = 327 kB = 0 MB 5356 Load Address: 00000000 5357 Entry Point: 0000000c 5358 Verifying Checksum ... OK 5359 5360 ## Checking Image at 40200000 ... 5361 Image Name: Simple Ramdisk Image 5362 Image Type: PowerPC Linux RAMDisk Image (gzip compressed) 5363 Data Size: 566530 Bytes = 553 kB = 0 MB 5364 Load Address: 00000000 5365 Entry Point: 00000000 5366 Verifying Checksum ... OK 5367 5368 => bootm 40100000 40200000 5369 ## Booting Linux kernel at 40100000 ... 5370 Image Name: 2.2.13 for initrd on TQM850L 5371 Image Type: PowerPC Linux Kernel Image (gzip compressed) 5372 Data Size: 335725 Bytes = 327 kB = 0 MB 5373 Load Address: 00000000 5374 Entry Point: 0000000c 5375 Verifying Checksum ... OK 5376 Uncompressing Kernel Image ... OK 5377 ## Loading RAMDisk Image at 40200000 ... 5378 Image Name: Simple Ramdisk Image 5379 Image Type: PowerPC Linux RAMDisk Image (gzip compressed) 5380 Data Size: 566530 Bytes = 553 kB = 0 MB 5381 Load Address: 00000000 5382 Entry Point: 00000000 5383 Verifying Checksum ... OK 5384 Loading Ramdisk ... OK 5385 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 5386 Boot arguments: root=/dev/ram 5387 time_init: decrementer frequency = 187500000/60 5388 Calibrating delay loop... 49.77 BogoMIPS 5389 ... 5390 RAMDISK: Compressed image found at block 0 5391 VFS: Mounted root (ext2 filesystem). 5392 5393 bash# 5394 5395Boot Linux and pass a flat device tree: 5396----------- 5397 5398First, U-Boot must be compiled with the appropriate defines. See the section 5399titled "Linux Kernel Interface" above for a more in depth explanation. The 5400following is an example of how to start a kernel and pass an updated 5401flat device tree: 5402 5403=> print oftaddr 5404oftaddr=0x300000 5405=> print oft 5406oft=oftrees/mpc8540ads.dtb 5407=> tftp $oftaddr $oft 5408Speed: 1000, full duplex 5409Using TSEC0 device 5410TFTP from server 192.168.1.1; our IP address is 192.168.1.101 5411Filename 'oftrees/mpc8540ads.dtb'. 5412Load address: 0x300000 5413Loading: # 5414done 5415Bytes transferred = 4106 (100a hex) 5416=> tftp $loadaddr $bootfile 5417Speed: 1000, full duplex 5418Using TSEC0 device 5419TFTP from server 192.168.1.1; our IP address is 192.168.1.2 5420Filename 'uImage'. 5421Load address: 0x200000 5422Loading:############ 5423done 5424Bytes transferred = 1029407 (fb51f hex) 5425=> print loadaddr 5426loadaddr=200000 5427=> print oftaddr 5428oftaddr=0x300000 5429=> bootm $loadaddr - $oftaddr 5430## Booting image at 00200000 ... 5431 Image Name: Linux-2.6.17-dirty 5432 Image Type: PowerPC Linux Kernel Image (gzip compressed) 5433 Data Size: 1029343 Bytes = 1005.2 kB 5434 Load Address: 00000000 5435 Entry Point: 00000000 5436 Verifying Checksum ... OK 5437 Uncompressing Kernel Image ... OK 5438Booting using flat device tree at 0x300000 5439Using MPC85xx ADS machine description 5440Memory CAM mapping: CAM0=256Mb, CAM1=256Mb, CAM2=0Mb residual: 0Mb 5441[snip] 5442 5443 5444More About U-Boot Image Types: 5445------------------------------ 5446 5447U-Boot supports the following image types: 5448 5449 "Standalone Programs" are directly runnable in the environment 5450 provided by U-Boot; it is expected that (if they behave 5451 well) you can continue to work in U-Boot after return from 5452 the Standalone Program. 5453 "OS Kernel Images" are usually images of some Embedded OS which 5454 will take over control completely. Usually these programs 5455 will install their own set of exception handlers, device 5456 drivers, set up the MMU, etc. - this means, that you cannot 5457 expect to re-enter U-Boot except by resetting the CPU. 5458 "RAMDisk Images" are more or less just data blocks, and their 5459 parameters (address, size) are passed to an OS kernel that is 5460 being started. 5461 "Multi-File Images" contain several images, typically an OS 5462 (Linux) kernel image and one or more data images like 5463 RAMDisks. This construct is useful for instance when you want 5464 to boot over the network using BOOTP etc., where the boot 5465 server provides just a single image file, but you want to get 5466 for instance an OS kernel and a RAMDisk image. 5467 5468 "Multi-File Images" start with a list of image sizes, each 5469 image size (in bytes) specified by an "uint32_t" in network 5470 byte order. This list is terminated by an "(uint32_t)0". 5471 Immediately after the terminating 0 follow the images, one by 5472 one, all aligned on "uint32_t" boundaries (size rounded up to 5473 a multiple of 4 bytes). 5474 5475 "Firmware Images" are binary images containing firmware (like 5476 U-Boot or FPGA images) which usually will be programmed to 5477 flash memory. 5478 5479 "Script files" are command sequences that will be executed by 5480 U-Boot's command interpreter; this feature is especially 5481 useful when you configure U-Boot to use a real shell (hush) 5482 as command interpreter. 5483 5484Booting the Linux zImage: 5485------------------------- 5486 5487On some platforms, it's possible to boot Linux zImage. This is done 5488using the "bootz" command. The syntax of "bootz" command is the same 5489as the syntax of "bootm" command. 5490 5491Note, defining the CONFIG_SUPPORT_RAW_INITRD allows user to supply 5492kernel with raw initrd images. The syntax is slightly different, the 5493address of the initrd must be augmented by it's size, in the following 5494format: "<initrd addres>:<initrd size>". 5495 5496 5497Standalone HOWTO: 5498================= 5499 5500One of the features of U-Boot is that you can dynamically load and 5501run "standalone" applications, which can use some resources of 5502U-Boot like console I/O functions or interrupt services. 5503 5504Two simple examples are included with the sources: 5505 5506"Hello World" Demo: 5507------------------- 5508 5509'examples/hello_world.c' contains a small "Hello World" Demo 5510application; it is automatically compiled when you build U-Boot. 5511It's configured to run at address 0x00040004, so you can play with it 5512like that: 5513 5514 => loads 5515 ## Ready for S-Record download ... 5516 ~>examples/hello_world.srec 5517 1 2 3 4 5 6 7 8 9 10 11 ... 5518 [file transfer complete] 5519 [connected] 5520 ## Start Addr = 0x00040004 5521 5522 => go 40004 Hello World! This is a test. 5523 ## Starting application at 0x00040004 ... 5524 Hello World 5525 argc = 7 5526 argv[0] = "40004" 5527 argv[1] = "Hello" 5528 argv[2] = "World!" 5529 argv[3] = "This" 5530 argv[4] = "is" 5531 argv[5] = "a" 5532 argv[6] = "test." 5533 argv[7] = "<NULL>" 5534 Hit any key to exit ... 5535 5536 ## Application terminated, rc = 0x0 5537 5538Another example, which demonstrates how to register a CPM interrupt 5539handler with the U-Boot code, can be found in 'examples/timer.c'. 5540Here, a CPM timer is set up to generate an interrupt every second. 5541The interrupt service routine is trivial, just printing a '.' 5542character, but this is just a demo program. The application can be 5543controlled by the following keys: 5544 5545 ? - print current values og the CPM Timer registers 5546 b - enable interrupts and start timer 5547 e - stop timer and disable interrupts 5548 q - quit application 5549 5550 => loads 5551 ## Ready for S-Record download ... 5552 ~>examples/timer.srec 5553 1 2 3 4 5 6 7 8 9 10 11 ... 5554 [file transfer complete] 5555 [connected] 5556 ## Start Addr = 0x00040004 5557 5558 => go 40004 5559 ## Starting application at 0x00040004 ... 5560 TIMERS=0xfff00980 5561 Using timer 1 5562 tgcr @ 0xfff00980, tmr @ 0xfff00990, trr @ 0xfff00994, tcr @ 0xfff00998, tcn @ 0xfff0099c, ter @ 0xfff009b0 5563 5564Hit 'b': 5565 [q, b, e, ?] Set interval 1000000 us 5566 Enabling timer 5567Hit '?': 5568 [q, b, e, ?] ........ 5569 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0xef6, ter=0x0 5570Hit '?': 5571 [q, b, e, ?] . 5572 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x2ad4, ter=0x0 5573Hit '?': 5574 [q, b, e, ?] . 5575 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x1efc, ter=0x0 5576Hit '?': 5577 [q, b, e, ?] . 5578 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x169d, ter=0x0 5579Hit 'e': 5580 [q, b, e, ?] ...Stopping timer 5581Hit 'q': 5582 [q, b, e, ?] ## Application terminated, rc = 0x0 5583 5584 5585Minicom warning: 5586================ 5587 5588Over time, many people have reported problems when trying to use the 5589"minicom" terminal emulation program for serial download. I (wd) 5590consider minicom to be broken, and recommend not to use it. Under 5591Unix, I recommend to use C-Kermit for general purpose use (and 5592especially for kermit binary protocol download ("loadb" command), and 5593use "cu" for S-Record download ("loads" command). See 5594http://www.denx.de/wiki/view/DULG/SystemSetup#Section_4.3. 5595for help with kermit. 5596 5597 5598Nevertheless, if you absolutely want to use it try adding this 5599configuration to your "File transfer protocols" section: 5600 5601 Name Program Name U/D FullScr IO-Red. Multi 5602 X kermit /usr/bin/kermit -i -l %l -s Y U Y N N 5603 Y kermit /usr/bin/kermit -i -l %l -r N D Y N N 5604 5605 5606NetBSD Notes: 5607============= 5608 5609Starting at version 0.9.2, U-Boot supports NetBSD both as host 5610(build U-Boot) and target system (boots NetBSD/mpc8xx). 5611 5612Building requires a cross environment; it is known to work on 5613NetBSD/i386 with the cross-powerpc-netbsd-1.3 package (you will also 5614need gmake since the Makefiles are not compatible with BSD make). 5615Note that the cross-powerpc package does not install include files; 5616attempting to build U-Boot will fail because <machine/ansi.h> is 5617missing. This file has to be installed and patched manually: 5618 5619 # cd /usr/pkg/cross/powerpc-netbsd/include 5620 # mkdir powerpc 5621 # ln -s powerpc machine 5622 # cp /usr/src/sys/arch/powerpc/include/ansi.h powerpc/ansi.h 5623 # ${EDIT} powerpc/ansi.h ## must remove __va_list, _BSD_VA_LIST 5624 5625Native builds *don't* work due to incompatibilities between native 5626and U-Boot include files. 5627 5628Booting assumes that (the first part of) the image booted is a 5629stage-2 loader which in turn loads and then invokes the kernel 5630proper. Loader sources will eventually appear in the NetBSD source 5631tree (probably in sys/arc/mpc8xx/stand/u-boot_stage2/); in the 5632meantime, see ftp://ftp.denx.de/pub/u-boot/ppcboot_stage2.tar.gz 5633 5634 5635Implementation Internals: 5636========================= 5637 5638The following is not intended to be a complete description of every 5639implementation detail. However, it should help to understand the 5640inner workings of U-Boot and make it easier to port it to custom 5641hardware. 5642 5643 5644Initial Stack, Global Data: 5645--------------------------- 5646 5647The implementation of U-Boot is complicated by the fact that U-Boot 5648starts running out of ROM (flash memory), usually without access to 5649system RAM (because the memory controller is not initialized yet). 5650This means that we don't have writable Data or BSS segments, and BSS 5651is not initialized as zero. To be able to get a C environment working 5652at all, we have to allocate at least a minimal stack. Implementation 5653options for this are defined and restricted by the CPU used: Some CPU 5654models provide on-chip memory (like the IMMR area on MPC8xx and 5655MPC826x processors), on others (parts of) the data cache can be 5656locked as (mis-) used as memory, etc. 5657 5658 Chris Hallinan posted a good summary of these issues to the 5659 U-Boot mailing list: 5660 5661 Subject: RE: [U-Boot-Users] RE: More On Memory Bank x (nothingness)? 5662 From: "Chris Hallinan" <clh@net1plus.com> 5663 Date: Mon, 10 Feb 2003 16:43:46 -0500 (22:43 MET) 5664 ... 5665 5666 Correct me if I'm wrong, folks, but the way I understand it 5667 is this: Using DCACHE as initial RAM for Stack, etc, does not 5668 require any physical RAM backing up the cache. The cleverness 5669 is that the cache is being used as a temporary supply of 5670 necessary storage before the SDRAM controller is setup. It's 5671 beyond the scope of this list to explain the details, but you 5672 can see how this works by studying the cache architecture and 5673 operation in the architecture and processor-specific manuals. 5674 5675 OCM is On Chip Memory, which I believe the 405GP has 4K. It 5676 is another option for the system designer to use as an 5677 initial stack/RAM area prior to SDRAM being available. Either 5678 option should work for you. Using CS 4 should be fine if your 5679 board designers haven't used it for something that would 5680 cause you grief during the initial boot! It is frequently not 5681 used. 5682 5683 CONFIG_SYS_INIT_RAM_ADDR should be somewhere that won't interfere 5684 with your processor/board/system design. The default value 5685 you will find in any recent u-boot distribution in 5686 walnut.h should work for you. I'd set it to a value larger 5687 than your SDRAM module. If you have a 64MB SDRAM module, set 5688 it above 400_0000. Just make sure your board has no resources 5689 that are supposed to respond to that address! That code in 5690 start.S has been around a while and should work as is when 5691 you get the config right. 5692 5693 -Chris Hallinan 5694 DS4.COM, Inc. 5695 5696It is essential to remember this, since it has some impact on the C 5697code for the initialization procedures: 5698 5699* Initialized global data (data segment) is read-only. Do not attempt 5700 to write it. 5701 5702* Do not use any uninitialized global data (or implicitly initialized 5703 as zero data - BSS segment) at all - this is undefined, initiali- 5704 zation is performed later (when relocating to RAM). 5705 5706* Stack space is very limited. Avoid big data buffers or things like 5707 that. 5708 5709Having only the stack as writable memory limits means we cannot use 5710normal global data to share information between the code. But it 5711turned out that the implementation of U-Boot can be greatly 5712simplified by making a global data structure (gd_t) available to all 5713functions. We could pass a pointer to this data as argument to _all_ 5714functions, but this would bloat the code. Instead we use a feature of 5715the GCC compiler (Global Register Variables) to share the data: we 5716place a pointer (gd) to the global data into a register which we 5717reserve for this purpose. 5718 5719When choosing a register for such a purpose we are restricted by the 5720relevant (E)ABI specifications for the current architecture, and by 5721GCC's implementation. 5722 5723For PowerPC, the following registers have specific use: 5724 R1: stack pointer 5725 R2: reserved for system use 5726 R3-R4: parameter passing and return values 5727 R5-R10: parameter passing 5728 R13: small data area pointer 5729 R30: GOT pointer 5730 R31: frame pointer 5731 5732 (U-Boot also uses R12 as internal GOT pointer. r12 5733 is a volatile register so r12 needs to be reset when 5734 going back and forth between asm and C) 5735 5736 ==> U-Boot will use R2 to hold a pointer to the global data 5737 5738 Note: on PPC, we could use a static initializer (since the 5739 address of the global data structure is known at compile time), 5740 but it turned out that reserving a register results in somewhat 5741 smaller code - although the code savings are not that big (on 5742 average for all boards 752 bytes for the whole U-Boot image, 5743 624 text + 127 data). 5744 5745On ARM, the following registers are used: 5746 5747 R0: function argument word/integer result 5748 R1-R3: function argument word 5749 R9: platform specific 5750 R10: stack limit (used only if stack checking is enabled) 5751 R11: argument (frame) pointer 5752 R12: temporary workspace 5753 R13: stack pointer 5754 R14: link register 5755 R15: program counter 5756 5757 ==> U-Boot will use R9 to hold a pointer to the global data 5758 5759 Note: on ARM, only R_ARM_RELATIVE relocations are supported. 5760 5761On Nios II, the ABI is documented here: 5762 http://www.altera.com/literature/hb/nios2/n2cpu_nii51016.pdf 5763 5764 ==> U-Boot will use gp to hold a pointer to the global data 5765 5766 Note: on Nios II, we give "-G0" option to gcc and don't use gp 5767 to access small data sections, so gp is free. 5768 5769On NDS32, the following registers are used: 5770 5771 R0-R1: argument/return 5772 R2-R5: argument 5773 R15: temporary register for assembler 5774 R16: trampoline register 5775 R28: frame pointer (FP) 5776 R29: global pointer (GP) 5777 R30: link register (LP) 5778 R31: stack pointer (SP) 5779 PC: program counter (PC) 5780 5781 ==> U-Boot will use R10 to hold a pointer to the global data 5782 5783NOTE: DECLARE_GLOBAL_DATA_PTR must be used with file-global scope, 5784or current versions of GCC may "optimize" the code too much. 5785 5786Memory Management: 5787------------------ 5788 5789U-Boot runs in system state and uses physical addresses, i.e. the 5790MMU is not used either for address mapping nor for memory protection. 5791 5792The available memory is mapped to fixed addresses using the memory 5793controller. In this process, a contiguous block is formed for each 5794memory type (Flash, SDRAM, SRAM), even when it consists of several 5795physical memory banks. 5796 5797U-Boot is installed in the first 128 kB of the first Flash bank (on 5798TQM8xxL modules this is the range 0x40000000 ... 0x4001FFFF). After 5799booting and sizing and initializing DRAM, the code relocates itself 5800to the upper end of DRAM. Immediately below the U-Boot code some 5801memory is reserved for use by malloc() [see CONFIG_SYS_MALLOC_LEN 5802configuration setting]. Below that, a structure with global Board 5803Info data is placed, followed by the stack (growing downward). 5804 5805Additionally, some exception handler code is copied to the low 8 kB 5806of DRAM (0x00000000 ... 0x00001FFF). 5807 5808So a typical memory configuration with 16 MB of DRAM could look like 5809this: 5810 5811 0x0000 0000 Exception Vector code 5812 : 5813 0x0000 1FFF 5814 0x0000 2000 Free for Application Use 5815 : 5816 : 5817 5818 : 5819 : 5820 0x00FB FF20 Monitor Stack (Growing downward) 5821 0x00FB FFAC Board Info Data and permanent copy of global data 5822 0x00FC 0000 Malloc Arena 5823 : 5824 0x00FD FFFF 5825 0x00FE 0000 RAM Copy of Monitor Code 5826 ... eventually: LCD or video framebuffer 5827 ... eventually: pRAM (Protected RAM - unchanged by reset) 5828 0x00FF FFFF [End of RAM] 5829 5830 5831System Initialization: 5832---------------------- 5833 5834In the reset configuration, U-Boot starts at the reset entry point 5835(on most PowerPC systems at address 0x00000100). Because of the reset 5836configuration for CS0# this is a mirror of the on board Flash memory. 5837To be able to re-map memory U-Boot then jumps to its link address. 5838To be able to implement the initialization code in C, a (small!) 5839initial stack is set up in the internal Dual Ported RAM (in case CPUs 5840which provide such a feature like MPC8xx or MPC8260), or in a locked 5841part of the data cache. After that, U-Boot initializes the CPU core, 5842the caches and the SIU. 5843 5844Next, all (potentially) available memory banks are mapped using a 5845preliminary mapping. For example, we put them on 512 MB boundaries 5846(multiples of 0x20000000: SDRAM on 0x00000000 and 0x20000000, Flash 5847on 0x40000000 and 0x60000000, SRAM on 0x80000000). Then UPM A is 5848programmed for SDRAM access. Using the temporary configuration, a 5849simple memory test is run that determines the size of the SDRAM 5850banks. 5851 5852When there is more than one SDRAM bank, and the banks are of 5853different size, the largest is mapped first. For equal size, the first 5854bank (CS2#) is mapped first. The first mapping is always for address 58550x00000000, with any additional banks following immediately to create 5856contiguous memory starting from 0. 5857 5858Then, the monitor installs itself at the upper end of the SDRAM area 5859and allocates memory for use by malloc() and for the global Board 5860Info data; also, the exception vector code is copied to the low RAM 5861pages, and the final stack is set up. 5862 5863Only after this relocation will you have a "normal" C environment; 5864until that you are restricted in several ways, mostly because you are 5865running from ROM, and because the code will have to be relocated to a 5866new address in RAM. 5867 5868 5869U-Boot Porting Guide: 5870---------------------- 5871 5872[Based on messages by Jerry Van Baren in the U-Boot-Users mailing 5873list, October 2002] 5874 5875 5876int main(int argc, char *argv[]) 5877{ 5878 sighandler_t no_more_time; 5879 5880 signal(SIGALRM, no_more_time); 5881 alarm(PROJECT_DEADLINE - toSec (3 * WEEK)); 5882 5883 if (available_money > available_manpower) { 5884 Pay consultant to port U-Boot; 5885 return 0; 5886 } 5887 5888 Download latest U-Boot source; 5889 5890 Subscribe to u-boot mailing list; 5891 5892 if (clueless) 5893 email("Hi, I am new to U-Boot, how do I get started?"); 5894 5895 while (learning) { 5896 Read the README file in the top level directory; 5897 Read http://www.denx.de/twiki/bin/view/DULG/Manual; 5898 Read applicable doc/*.README; 5899 Read the source, Luke; 5900 /* find . -name "*.[chS]" | xargs grep -i <keyword> */ 5901 } 5902 5903 if (available_money > toLocalCurrency ($2500)) 5904 Buy a BDI3000; 5905 else 5906 Add a lot of aggravation and time; 5907 5908 if (a similar board exists) { /* hopefully... */ 5909 cp -a board/<similar> board/<myboard> 5910 cp include/configs/<similar>.h include/configs/<myboard>.h 5911 } else { 5912 Create your own board support subdirectory; 5913 Create your own board include/configs/<myboard>.h file; 5914 } 5915 Edit new board/<myboard> files 5916 Edit new include/configs/<myboard>.h 5917 5918 while (!accepted) { 5919 while (!running) { 5920 do { 5921 Add / modify source code; 5922 } until (compiles); 5923 Debug; 5924 if (clueless) 5925 email("Hi, I am having problems..."); 5926 } 5927 Send patch file to the U-Boot email list; 5928 if (reasonable critiques) 5929 Incorporate improvements from email list code review; 5930 else 5931 Defend code as written; 5932 } 5933 5934 return 0; 5935} 5936 5937void no_more_time (int sig) 5938{ 5939 hire_a_guru(); 5940} 5941 5942 5943Coding Standards: 5944----------------- 5945 5946All contributions to U-Boot should conform to the Linux kernel 5947coding style; see the file "Documentation/CodingStyle" and the script 5948"scripts/Lindent" in your Linux kernel source directory. 5949 5950Source files originating from a different project (for example the 5951MTD subsystem) are generally exempt from these guidelines and are not 5952reformatted to ease subsequent migration to newer versions of those 5953sources. 5954 5955Please note that U-Boot is implemented in C (and to some small parts in 5956Assembler); no C++ is used, so please do not use C++ style comments (//) 5957in your code. 5958 5959Please also stick to the following formatting rules: 5960- remove any trailing white space 5961- use TAB characters for indentation and vertical alignment, not spaces 5962- make sure NOT to use DOS '\r\n' line feeds 5963- do not add more than 2 consecutive empty lines to source files 5964- do not add trailing empty lines to source files 5965 5966Submissions which do not conform to the standards may be returned 5967with a request to reformat the changes. 5968 5969 5970Submitting Patches: 5971------------------- 5972 5973Since the number of patches for U-Boot is growing, we need to 5974establish some rules. Submissions which do not conform to these rules 5975may be rejected, even when they contain important and valuable stuff. 5976 5977Please see http://www.denx.de/wiki/U-Boot/Patches for details. 5978 5979Patches shall be sent to the u-boot mailing list <u-boot@lists.denx.de>; 5980see http://lists.denx.de/mailman/listinfo/u-boot 5981 5982When you send a patch, please include the following information with 5983it: 5984 5985* For bug fixes: a description of the bug and how your patch fixes 5986 this bug. Please try to include a way of demonstrating that the 5987 patch actually fixes something. 5988 5989* For new features: a description of the feature and your 5990 implementation. 5991 5992* A CHANGELOG entry as plaintext (separate from the patch) 5993 5994* For major contributions, add a MAINTAINERS file with your 5995 information and associated file and directory references. 5996 5997* When you add support for a new board, don't forget to add a 5998 maintainer e-mail address to the boards.cfg file, too. 5999 6000* If your patch adds new configuration options, don't forget to 6001 document these in the README file. 6002 6003* The patch itself. If you are using git (which is *strongly* 6004 recommended) you can easily generate the patch using the 6005 "git format-patch". If you then use "git send-email" to send it to 6006 the U-Boot mailing list, you will avoid most of the common problems 6007 with some other mail clients. 6008 6009 If you cannot use git, use "diff -purN OLD NEW". If your version of 6010 diff does not support these options, then get the latest version of 6011 GNU diff. 6012 6013 The current directory when running this command shall be the parent 6014 directory of the U-Boot source tree (i. e. please make sure that 6015 your patch includes sufficient directory information for the 6016 affected files). 6017 6018 We prefer patches as plain text. MIME attachments are discouraged, 6019 and compressed attachments must not be used. 6020 6021* If one logical set of modifications affects or creates several 6022 files, all these changes shall be submitted in a SINGLE patch file. 6023 6024* Changesets that contain different, unrelated modifications shall be 6025 submitted as SEPARATE patches, one patch per changeset. 6026 6027 6028Notes: 6029 6030* Before sending the patch, run the buildman script on your patched 6031 source tree and make sure that no errors or warnings are reported 6032 for any of the boards. 6033 6034* Keep your modifications to the necessary minimum: A patch 6035 containing several unrelated changes or arbitrary reformats will be 6036 returned with a request to re-formatting / split it. 6037 6038* If you modify existing code, make sure that your new code does not 6039 add to the memory footprint of the code ;-) Small is beautiful! 6040 When adding new features, these should compile conditionally only 6041 (using #ifdef), and the resulting code with the new feature 6042 disabled must not need more memory than the old code without your 6043 modification. 6044 6045* Remember that there is a size limit of 100 kB per message on the 6046 u-boot mailing list. Bigger patches will be moderated. If they are 6047 reasonable and not too big, they will be acknowledged. But patches 6048 bigger than the size limit should be avoided. 6049