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_ITEST Integer/string test of 2 values 856 CONFIG_CMD_LDRINFO * ldrinfo (display Blackfin loader) 857 CONFIG_CMD_LINK_LOCAL * link-local IP address auto-configuration 858 (169.254.*.*) 859 CONFIG_CMD_LOADB loadb 860 CONFIG_CMD_LOADS loads 861 CONFIG_CMD_MD5SUM * print md5 message digest 862 (requires CONFIG_CMD_MEMORY and CONFIG_MD5) 863 CONFIG_CMD_MEMINFO * Display detailed memory information 864 CONFIG_CMD_MEMORY md, mm, nm, mw, cp, cmp, crc, base, 865 loop, loopw 866 CONFIG_CMD_MEMTEST * mtest 867 CONFIG_CMD_MISC Misc functions like sleep etc 868 CONFIG_CMD_MMC * MMC memory mapped support 869 CONFIG_CMD_MII * MII utility commands 870 CONFIG_CMD_MTDPARTS * MTD partition support 871 CONFIG_CMD_NAND * NAND support 872 CONFIG_CMD_NET bootp, tftpboot, rarpboot 873 CONFIG_CMD_NFS NFS support 874 CONFIG_CMD_PCA953X * PCA953x I2C gpio commands 875 CONFIG_CMD_PCA953X_INFO * PCA953x I2C gpio info command 876 CONFIG_CMD_PCI * pciinfo 877 CONFIG_CMD_PCMCIA * PCMCIA support 878 CONFIG_CMD_PING * send ICMP ECHO_REQUEST to network 879 host 880 CONFIG_CMD_PORTIO * Port I/O 881 CONFIG_CMD_READ * Read raw data from partition 882 CONFIG_CMD_REGINFO * Register dump 883 CONFIG_CMD_RUN run command in env variable 884 CONFIG_CMD_SANDBOX * sb command to access sandbox features 885 CONFIG_CMD_SAVES * save S record dump 886 CONFIG_SCSI * SCSI Support 887 CONFIG_CMD_SDRAM * print SDRAM configuration information 888 (requires CONFIG_CMD_I2C) 889 CONFIG_CMD_SETGETDCR Support for DCR Register access 890 (4xx only) 891 CONFIG_CMD_SF * Read/write/erase SPI NOR flash 892 CONFIG_CMD_SHA1SUM * print sha1 memory digest 893 (requires CONFIG_CMD_MEMORY) 894 CONFIG_CMD_SOFTSWITCH * Soft switch setting command for BF60x 895 CONFIG_CMD_SOURCE "source" command Support 896 CONFIG_CMD_SPI * SPI serial bus support 897 CONFIG_CMD_TFTPSRV * TFTP transfer in server mode 898 CONFIG_CMD_TFTPPUT * TFTP put command (upload) 899 CONFIG_CMD_TIME * run command and report execution time (ARM specific) 900 CONFIG_CMD_TIMER * access to the system tick timer 901 CONFIG_CMD_USB * USB support 902 CONFIG_CMD_CDP * Cisco Discover Protocol support 903 CONFIG_CMD_MFSL * Microblaze FSL support 904 CONFIG_CMD_XIMG Load part of Multi Image 905 CONFIG_CMD_UUID * Generate random UUID or GUID string 906 907 EXAMPLE: If you want all functions except of network 908 support you can write: 909 910 #include "config_cmd_all.h" 911 #undef CONFIG_CMD_NET 912 913 Other Commands: 914 fdt (flattened device tree) command: CONFIG_OF_LIBFDT 915 916 Note: Don't enable the "icache" and "dcache" commands 917 (configuration option CONFIG_CMD_CACHE) unless you know 918 what you (and your U-Boot users) are doing. Data 919 cache cannot be enabled on systems like the 8xx or 920 8260 (where accesses to the IMMR region must be 921 uncached), and it cannot be disabled on all other 922 systems where we (mis-) use the data cache to hold an 923 initial stack and some data. 924 925 926 XXX - this list needs to get updated! 927 928- Removal of commands 929 If no commands are needed to boot, you can disable 930 CONFIG_CMDLINE to remove them. In this case, the command line 931 will not be available, and when U-Boot wants to execute the 932 boot command (on start-up) it will call board_run_command() 933 instead. This can reduce image size significantly for very 934 simple boot procedures. 935 936- Regular expression support: 937 CONFIG_REGEX 938 If this variable is defined, U-Boot is linked against 939 the SLRE (Super Light Regular Expression) library, 940 which adds regex support to some commands, as for 941 example "env grep" and "setexpr". 942 943- Device tree: 944 CONFIG_OF_CONTROL 945 If this variable is defined, U-Boot will use a device tree 946 to configure its devices, instead of relying on statically 947 compiled #defines in the board file. This option is 948 experimental and only available on a few boards. The device 949 tree is available in the global data as gd->fdt_blob. 950 951 U-Boot needs to get its device tree from somewhere. This can 952 be done using one of the three options below: 953 954 CONFIG_OF_EMBED 955 If this variable is defined, U-Boot will embed a device tree 956 binary in its image. This device tree file should be in the 957 board directory and called <soc>-<board>.dts. The binary file 958 is then picked up in board_init_f() and made available through 959 the global data structure as gd->blob. 960 961 CONFIG_OF_SEPARATE 962 If this variable is defined, U-Boot will build a device tree 963 binary. It will be called u-boot.dtb. Architecture-specific 964 code will locate it at run-time. Generally this works by: 965 966 cat u-boot.bin u-boot.dtb >image.bin 967 968 and in fact, U-Boot does this for you, creating a file called 969 u-boot-dtb.bin which is useful in the common case. You can 970 still use the individual files if you need something more 971 exotic. 972 973 CONFIG_OF_BOARD 974 If this variable is defined, U-Boot will use the device tree 975 provided by the board at runtime instead of embedding one with 976 the image. Only boards defining board_fdt_blob_setup() support 977 this option (see include/fdtdec.h file). 978 979- Watchdog: 980 CONFIG_WATCHDOG 981 If this variable is defined, it enables watchdog 982 support for the SoC. There must be support in the SoC 983 specific code for a watchdog. For the 8xx and 8260 984 CPUs, the SIU Watchdog feature is enabled in the SYPCR 985 register. When supported for a specific SoC is 986 available, then no further board specific code should 987 be needed to use it. 988 989 CONFIG_HW_WATCHDOG 990 When using a watchdog circuitry external to the used 991 SoC, then define this variable and provide board 992 specific code for the "hw_watchdog_reset" function. 993 994 CONFIG_AT91_HW_WDT_TIMEOUT 995 specify the timeout in seconds. default 2 seconds. 996 997- U-Boot Version: 998 CONFIG_VERSION_VARIABLE 999 If this variable is defined, an environment variable 1000 named "ver" is created by U-Boot showing the U-Boot 1001 version as printed by the "version" command. 1002 Any change to this variable will be reverted at the 1003 next reset. 1004 1005- Real-Time Clock: 1006 1007 When CONFIG_CMD_DATE is selected, the type of the RTC 1008 has to be selected, too. Define exactly one of the 1009 following options: 1010 1011 CONFIG_RTC_MPC8xx - use internal RTC of MPC8xx 1012 CONFIG_RTC_PCF8563 - use Philips PCF8563 RTC 1013 CONFIG_RTC_MC13XXX - use MC13783 or MC13892 RTC 1014 CONFIG_RTC_MC146818 - use MC146818 RTC 1015 CONFIG_RTC_DS1307 - use Maxim, Inc. DS1307 RTC 1016 CONFIG_RTC_DS1337 - use Maxim, Inc. DS1337 RTC 1017 CONFIG_RTC_DS1338 - use Maxim, Inc. DS1338 RTC 1018 CONFIG_RTC_DS1339 - use Maxim, Inc. DS1339 RTC 1019 CONFIG_RTC_DS164x - use Dallas DS164x RTC 1020 CONFIG_RTC_ISL1208 - use Intersil ISL1208 RTC 1021 CONFIG_RTC_MAX6900 - use Maxim, Inc. MAX6900 RTC 1022 CONFIG_SYS_RTC_DS1337_NOOSC - Turn off the OSC output for DS1337 1023 CONFIG_SYS_RV3029_TCR - enable trickle charger on 1024 RV3029 RTC. 1025 1026 Note that if the RTC uses I2C, then the I2C interface 1027 must also be configured. See I2C Support, below. 1028 1029- GPIO Support: 1030 CONFIG_PCA953X - use NXP's PCA953X series I2C GPIO 1031 1032 The CONFIG_SYS_I2C_PCA953X_WIDTH option specifies a list of 1033 chip-ngpio pairs that tell the PCA953X driver the number of 1034 pins supported by a particular chip. 1035 1036 Note that if the GPIO device uses I2C, then the I2C interface 1037 must also be configured. See I2C Support, below. 1038 1039- I/O tracing: 1040 When CONFIG_IO_TRACE is selected, U-Boot intercepts all I/O 1041 accesses and can checksum them or write a list of them out 1042 to memory. See the 'iotrace' command for details. This is 1043 useful for testing device drivers since it can confirm that 1044 the driver behaves the same way before and after a code 1045 change. Currently this is supported on sandbox and arm. To 1046 add support for your architecture, add '#include <iotrace.h>' 1047 to the bottom of arch/<arch>/include/asm/io.h and test. 1048 1049 Example output from the 'iotrace stats' command is below. 1050 Note that if the trace buffer is exhausted, the checksum will 1051 still continue to operate. 1052 1053 iotrace is enabled 1054 Start: 10000000 (buffer start address) 1055 Size: 00010000 (buffer size) 1056 Offset: 00000120 (current buffer offset) 1057 Output: 10000120 (start + offset) 1058 Count: 00000018 (number of trace records) 1059 CRC32: 9526fb66 (CRC32 of all trace records) 1060 1061- Timestamp Support: 1062 1063 When CONFIG_TIMESTAMP is selected, the timestamp 1064 (date and time) of an image is printed by image 1065 commands like bootm or iminfo. This option is 1066 automatically enabled when you select CONFIG_CMD_DATE . 1067 1068- Partition Labels (disklabels) Supported: 1069 Zero or more of the following: 1070 CONFIG_MAC_PARTITION Apple's MacOS partition table. 1071 CONFIG_DOS_PARTITION MS Dos partition table, traditional on the 1072 Intel architecture, USB sticks, etc. 1073 CONFIG_ISO_PARTITION ISO partition table, used on CDROM etc. 1074 CONFIG_EFI_PARTITION GPT partition table, common when EFI is the 1075 bootloader. Note 2TB partition limit; see 1076 disk/part_efi.c 1077 CONFIG_MTD_PARTITIONS Memory Technology Device partition table. 1078 1079 If IDE or SCSI support is enabled (CONFIG_IDE or 1080 CONFIG_SCSI) you must configure support for at 1081 least one non-MTD partition type as well. 1082 1083- IDE Reset method: 1084 CONFIG_IDE_RESET_ROUTINE - this is defined in several 1085 board configurations files but used nowhere! 1086 1087 CONFIG_IDE_RESET - is this is defined, IDE Reset will 1088 be performed by calling the function 1089 ide_set_reset(int reset) 1090 which has to be defined in a board specific file 1091 1092- ATAPI Support: 1093 CONFIG_ATAPI 1094 1095 Set this to enable ATAPI support. 1096 1097- LBA48 Support 1098 CONFIG_LBA48 1099 1100 Set this to enable support for disks larger than 137GB 1101 Also look at CONFIG_SYS_64BIT_LBA. 1102 Whithout these , LBA48 support uses 32bit variables and will 'only' 1103 support disks up to 2.1TB. 1104 1105 CONFIG_SYS_64BIT_LBA: 1106 When enabled, makes the IDE subsystem use 64bit sector addresses. 1107 Default is 32bit. 1108 1109- SCSI Support: 1110 At the moment only there is only support for the 1111 SYM53C8XX SCSI controller; define 1112 CONFIG_SCSI_SYM53C8XX to enable it. 1113 1114 CONFIG_SYS_SCSI_MAX_LUN [8], CONFIG_SYS_SCSI_MAX_SCSI_ID [7] and 1115 CONFIG_SYS_SCSI_MAX_DEVICE [CONFIG_SYS_SCSI_MAX_SCSI_ID * 1116 CONFIG_SYS_SCSI_MAX_LUN] can be adjusted to define the 1117 maximum numbers of LUNs, SCSI ID's and target 1118 devices. 1119 CONFIG_SYS_SCSI_SYM53C8XX_CCF to fix clock timing (80Mhz) 1120 1121 The environment variable 'scsidevs' is set to the number of 1122 SCSI devices found during the last scan. 1123 1124- NETWORK Support (PCI): 1125 CONFIG_E1000 1126 Support for Intel 8254x/8257x gigabit chips. 1127 1128 CONFIG_E1000_SPI 1129 Utility code for direct access to the SPI bus on Intel 8257x. 1130 This does not do anything useful unless you set at least one 1131 of CONFIG_CMD_E1000 or CONFIG_E1000_SPI_GENERIC. 1132 1133 CONFIG_E1000_SPI_GENERIC 1134 Allow generic access to the SPI bus on the Intel 8257x, for 1135 example with the "sspi" command. 1136 1137 CONFIG_CMD_E1000 1138 Management command for E1000 devices. When used on devices 1139 with SPI support you can reprogram the EEPROM from U-Boot. 1140 1141 CONFIG_EEPRO100 1142 Support for Intel 82557/82559/82559ER chips. 1143 Optional CONFIG_EEPRO100_SROM_WRITE enables EEPROM 1144 write routine for first time initialisation. 1145 1146 CONFIG_TULIP 1147 Support for Digital 2114x chips. 1148 Optional CONFIG_TULIP_SELECT_MEDIA for board specific 1149 modem chip initialisation (KS8761/QS6611). 1150 1151 CONFIG_NATSEMI 1152 Support for National dp83815 chips. 1153 1154 CONFIG_NS8382X 1155 Support for National dp8382[01] gigabit chips. 1156 1157- NETWORK Support (other): 1158 1159 CONFIG_DRIVER_AT91EMAC 1160 Support for AT91RM9200 EMAC. 1161 1162 CONFIG_RMII 1163 Define this to use reduced MII inteface 1164 1165 CONFIG_DRIVER_AT91EMAC_QUIET 1166 If this defined, the driver is quiet. 1167 The driver doen't show link status messages. 1168 1169 CONFIG_CALXEDA_XGMAC 1170 Support for the Calxeda XGMAC device 1171 1172 CONFIG_LAN91C96 1173 Support for SMSC's LAN91C96 chips. 1174 1175 CONFIG_LAN91C96_USE_32_BIT 1176 Define this to enable 32 bit addressing 1177 1178 CONFIG_SMC91111 1179 Support for SMSC's LAN91C111 chip 1180 1181 CONFIG_SMC91111_BASE 1182 Define this to hold the physical address 1183 of the device (I/O space) 1184 1185 CONFIG_SMC_USE_32_BIT 1186 Define this if data bus is 32 bits 1187 1188 CONFIG_SMC_USE_IOFUNCS 1189 Define this to use i/o functions instead of macros 1190 (some hardware wont work with macros) 1191 1192 CONFIG_DRIVER_TI_EMAC 1193 Support for davinci emac 1194 1195 CONFIG_SYS_DAVINCI_EMAC_PHY_COUNT 1196 Define this if you have more then 3 PHYs. 1197 1198 CONFIG_FTGMAC100 1199 Support for Faraday's FTGMAC100 Gigabit SoC Ethernet 1200 1201 CONFIG_FTGMAC100_EGIGA 1202 Define this to use GE link update with gigabit PHY. 1203 Define this if FTGMAC100 is connected to gigabit PHY. 1204 If your system has 10/100 PHY only, it might not occur 1205 wrong behavior. Because PHY usually return timeout or 1206 useless data when polling gigabit status and gigabit 1207 control registers. This behavior won't affect the 1208 correctnessof 10/100 link speed update. 1209 1210 CONFIG_SMC911X 1211 Support for SMSC's LAN911x and LAN921x chips 1212 1213 CONFIG_SMC911X_BASE 1214 Define this to hold the physical address 1215 of the device (I/O space) 1216 1217 CONFIG_SMC911X_32_BIT 1218 Define this if data bus is 32 bits 1219 1220 CONFIG_SMC911X_16_BIT 1221 Define this if data bus is 16 bits. If your processor 1222 automatically converts one 32 bit word to two 16 bit 1223 words you may also try CONFIG_SMC911X_32_BIT. 1224 1225 CONFIG_SH_ETHER 1226 Support for Renesas on-chip Ethernet controller 1227 1228 CONFIG_SH_ETHER_USE_PORT 1229 Define the number of ports to be used 1230 1231 CONFIG_SH_ETHER_PHY_ADDR 1232 Define the ETH PHY's address 1233 1234 CONFIG_SH_ETHER_CACHE_WRITEBACK 1235 If this option is set, the driver enables cache flush. 1236 1237- PWM Support: 1238 CONFIG_PWM_IMX 1239 Support for PWM module on the imx6. 1240 1241- TPM Support: 1242 CONFIG_TPM 1243 Support TPM devices. 1244 1245 CONFIG_TPM_TIS_INFINEON 1246 Support for Infineon i2c bus TPM devices. Only one device 1247 per system is supported at this time. 1248 1249 CONFIG_TPM_TIS_I2C_BURST_LIMITATION 1250 Define the burst count bytes upper limit 1251 1252 CONFIG_TPM_ST33ZP24 1253 Support for STMicroelectronics TPM devices. Requires DM_TPM support. 1254 1255 CONFIG_TPM_ST33ZP24_I2C 1256 Support for STMicroelectronics ST33ZP24 I2C devices. 1257 Requires TPM_ST33ZP24 and I2C. 1258 1259 CONFIG_TPM_ST33ZP24_SPI 1260 Support for STMicroelectronics ST33ZP24 SPI devices. 1261 Requires TPM_ST33ZP24 and SPI. 1262 1263 CONFIG_TPM_ATMEL_TWI 1264 Support for Atmel TWI TPM device. Requires I2C support. 1265 1266 CONFIG_TPM_TIS_LPC 1267 Support for generic parallel port TPM devices. Only one device 1268 per system is supported at this time. 1269 1270 CONFIG_TPM_TIS_BASE_ADDRESS 1271 Base address where the generic TPM device is mapped 1272 to. Contemporary x86 systems usually map it at 1273 0xfed40000. 1274 1275 CONFIG_CMD_TPM 1276 Add tpm monitor functions. 1277 Requires CONFIG_TPM. If CONFIG_TPM_AUTH_SESSIONS is set, also 1278 provides monitor access to authorized functions. 1279 1280 CONFIG_TPM 1281 Define this to enable the TPM support library which provides 1282 functional interfaces to some TPM commands. 1283 Requires support for a TPM device. 1284 1285 CONFIG_TPM_AUTH_SESSIONS 1286 Define this to enable authorized functions in the TPM library. 1287 Requires CONFIG_TPM and CONFIG_SHA1. 1288 1289- USB Support: 1290 At the moment only the UHCI host controller is 1291 supported (PIP405, MIP405, MPC5200); define 1292 CONFIG_USB_UHCI to enable it. 1293 define CONFIG_USB_KEYBOARD to enable the USB Keyboard 1294 and define CONFIG_USB_STORAGE to enable the USB 1295 storage devices. 1296 Note: 1297 Supported are USB Keyboards and USB Floppy drives 1298 (TEAC FD-05PUB). 1299 MPC5200 USB requires additional defines: 1300 CONFIG_USB_CLOCK 1301 for 528 MHz Clock: 0x0001bbbb 1302 CONFIG_PSC3_USB 1303 for USB on PSC3 1304 CONFIG_USB_CONFIG 1305 for differential drivers: 0x00001000 1306 for single ended drivers: 0x00005000 1307 for differential drivers on PSC3: 0x00000100 1308 for single ended drivers on PSC3: 0x00004100 1309 CONFIG_SYS_USB_EVENT_POLL 1310 May be defined to allow interrupt polling 1311 instead of using asynchronous interrupts 1312 1313 CONFIG_USB_EHCI_TXFIFO_THRESH enables setting of the 1314 txfilltuning field in the EHCI controller on reset. 1315 1316 CONFIG_USB_DWC2_REG_ADDR the physical CPU address of the DWC2 1317 HW module registers. 1318 1319- USB Device: 1320 Define the below if you wish to use the USB console. 1321 Once firmware is rebuilt from a serial console issue the 1322 command "setenv stdin usbtty; setenv stdout usbtty" and 1323 attach your USB cable. The Unix command "dmesg" should print 1324 it has found a new device. The environment variable usbtty 1325 can be set to gserial or cdc_acm to enable your device to 1326 appear to a USB host as a Linux gserial device or a 1327 Common Device Class Abstract Control Model serial device. 1328 If you select usbtty = gserial you should be able to enumerate 1329 a Linux host by 1330 # modprobe usbserial vendor=0xVendorID product=0xProductID 1331 else if using cdc_acm, simply setting the environment 1332 variable usbtty to be cdc_acm should suffice. The following 1333 might be defined in YourBoardName.h 1334 1335 CONFIG_USB_DEVICE 1336 Define this to build a UDC device 1337 1338 CONFIG_USB_TTY 1339 Define this to have a tty type of device available to 1340 talk to the UDC device 1341 1342 CONFIG_USBD_HS 1343 Define this to enable the high speed support for usb 1344 device and usbtty. If this feature is enabled, a routine 1345 int is_usbd_high_speed(void) 1346 also needs to be defined by the driver to dynamically poll 1347 whether the enumeration has succeded at high speed or full 1348 speed. 1349 1350 CONFIG_SYS_CONSOLE_IS_IN_ENV 1351 Define this if you want stdin, stdout &/or stderr to 1352 be set to usbtty. 1353 1354 mpc8xx: 1355 CONFIG_SYS_USB_EXTC_CLK 0xBLAH 1356 Derive USB clock from external clock "blah" 1357 - CONFIG_SYS_USB_EXTC_CLK 0x02 1358 1359 If you have a USB-IF assigned VendorID then you may wish to 1360 define your own vendor specific values either in BoardName.h 1361 or directly in usbd_vendor_info.h. If you don't define 1362 CONFIG_USBD_MANUFACTURER, CONFIG_USBD_PRODUCT_NAME, 1363 CONFIG_USBD_VENDORID and CONFIG_USBD_PRODUCTID, then U-Boot 1364 should pretend to be a Linux device to it's target host. 1365 1366 CONFIG_USBD_MANUFACTURER 1367 Define this string as the name of your company for 1368 - CONFIG_USBD_MANUFACTURER "my company" 1369 1370 CONFIG_USBD_PRODUCT_NAME 1371 Define this string as the name of your product 1372 - CONFIG_USBD_PRODUCT_NAME "acme usb device" 1373 1374 CONFIG_USBD_VENDORID 1375 Define this as your assigned Vendor ID from the USB 1376 Implementors Forum. This *must* be a genuine Vendor ID 1377 to avoid polluting the USB namespace. 1378 - CONFIG_USBD_VENDORID 0xFFFF 1379 1380 CONFIG_USBD_PRODUCTID 1381 Define this as the unique Product ID 1382 for your device 1383 - CONFIG_USBD_PRODUCTID 0xFFFF 1384 1385- ULPI Layer Support: 1386 The ULPI (UTMI Low Pin (count) Interface) PHYs are supported via 1387 the generic ULPI layer. The generic layer accesses the ULPI PHY 1388 via the platform viewport, so you need both the genric layer and 1389 the viewport enabled. Currently only Chipidea/ARC based 1390 viewport is supported. 1391 To enable the ULPI layer support, define CONFIG_USB_ULPI and 1392 CONFIG_USB_ULPI_VIEWPORT in your board configuration file. 1393 If your ULPI phy needs a different reference clock than the 1394 standard 24 MHz then you have to define CONFIG_ULPI_REF_CLK to 1395 the appropriate value in Hz. 1396 1397- MMC Support: 1398 The MMC controller on the Intel PXA is supported. To 1399 enable this define CONFIG_MMC. The MMC can be 1400 accessed from the boot prompt by mapping the device 1401 to physical memory similar to flash. Command line is 1402 enabled with CONFIG_CMD_MMC. The MMC driver also works with 1403 the FAT fs. This is enabled with CONFIG_CMD_FAT. 1404 1405 CONFIG_SH_MMCIF 1406 Support for Renesas on-chip MMCIF controller 1407 1408 CONFIG_SH_MMCIF_ADDR 1409 Define the base address of MMCIF registers 1410 1411 CONFIG_SH_MMCIF_CLK 1412 Define the clock frequency for MMCIF 1413 1414 CONFIG_SUPPORT_EMMC_BOOT 1415 Enable some additional features of the eMMC boot partitions. 1416 1417 CONFIG_SUPPORT_EMMC_RPMB 1418 Enable the commands for reading, writing and programming the 1419 key for the Replay Protection Memory Block partition in eMMC. 1420 1421- USB Device Firmware Update (DFU) class support: 1422 CONFIG_USB_FUNCTION_DFU 1423 This enables the USB portion of the DFU USB class 1424 1425 CONFIG_CMD_DFU 1426 This enables the command "dfu" which is used to have 1427 U-Boot create a DFU class device via USB. This command 1428 requires that the "dfu_alt_info" environment variable be 1429 set and define the alt settings to expose to the host. 1430 1431 CONFIG_DFU_MMC 1432 This enables support for exposing (e)MMC devices via DFU. 1433 1434 CONFIG_DFU_NAND 1435 This enables support for exposing NAND devices via DFU. 1436 1437 CONFIG_DFU_RAM 1438 This enables support for exposing RAM via DFU. 1439 Note: DFU spec refer to non-volatile memory usage, but 1440 allow usages beyond the scope of spec - here RAM usage, 1441 one that would help mostly the developer. 1442 1443 CONFIG_SYS_DFU_DATA_BUF_SIZE 1444 Dfu transfer uses a buffer before writing data to the 1445 raw storage device. Make the size (in bytes) of this buffer 1446 configurable. The size of this buffer is also configurable 1447 through the "dfu_bufsiz" environment variable. 1448 1449 CONFIG_SYS_DFU_MAX_FILE_SIZE 1450 When updating files rather than the raw storage device, 1451 we use a static buffer to copy the file into and then write 1452 the buffer once we've been given the whole file. Define 1453 this to the maximum filesize (in bytes) for the buffer. 1454 Default is 4 MiB if undefined. 1455 1456 DFU_DEFAULT_POLL_TIMEOUT 1457 Poll timeout [ms], is the timeout a device can send to the 1458 host. The host must wait for this timeout before sending 1459 a subsequent DFU_GET_STATUS request to the device. 1460 1461 DFU_MANIFEST_POLL_TIMEOUT 1462 Poll timeout [ms], which the device sends to the host when 1463 entering dfuMANIFEST state. Host waits this timeout, before 1464 sending again an USB request to the device. 1465 1466- USB Device Android Fastboot support: 1467 CONFIG_USB_FUNCTION_FASTBOOT 1468 This enables the USB part of the fastboot gadget 1469 1470 CONFIG_CMD_FASTBOOT 1471 This enables the command "fastboot" which enables the Android 1472 fastboot mode for the platform's USB device. Fastboot is a USB 1473 protocol for downloading images, flashing and device control 1474 used on Android devices. 1475 See doc/README.android-fastboot for more information. 1476 1477 CONFIG_ANDROID_BOOT_IMAGE 1478 This enables support for booting images which use the Android 1479 image format header. 1480 1481 CONFIG_FASTBOOT_BUF_ADDR 1482 The fastboot protocol requires a large memory buffer for 1483 downloads. Define this to the starting RAM address to use for 1484 downloaded images. 1485 1486 CONFIG_FASTBOOT_BUF_SIZE 1487 The fastboot protocol requires a large memory buffer for 1488 downloads. This buffer should be as large as possible for a 1489 platform. Define this to the size available RAM for fastboot. 1490 1491 CONFIG_FASTBOOT_FLASH 1492 The fastboot protocol includes a "flash" command for writing 1493 the downloaded image to a non-volatile storage device. Define 1494 this to enable the "fastboot flash" command. 1495 1496 CONFIG_FASTBOOT_FLASH_MMC_DEV 1497 The fastboot "flash" command requires additional information 1498 regarding the non-volatile storage device. Define this to 1499 the eMMC device that fastboot should use to store the image. 1500 1501 CONFIG_FASTBOOT_GPT_NAME 1502 The fastboot "flash" command supports writing the downloaded 1503 image to the Protective MBR and the Primary GUID Partition 1504 Table. (Additionally, this downloaded image is post-processed 1505 to generate and write the Backup GUID Partition Table.) 1506 This occurs when the specified "partition name" on the 1507 "fastboot flash" command line matches this value. 1508 The default is "gpt" if undefined. 1509 1510 CONFIG_FASTBOOT_MBR_NAME 1511 The fastboot "flash" command supports writing the downloaded 1512 image to DOS MBR. 1513 This occurs when the "partition name" specified on the 1514 "fastboot flash" command line matches this value. 1515 If not defined the default value "mbr" is used. 1516 1517- Journaling Flash filesystem support: 1518 CONFIG_JFFS2_NAND 1519 Define these for a default partition on a NAND device 1520 1521 CONFIG_SYS_JFFS2_FIRST_SECTOR, 1522 CONFIG_SYS_JFFS2_FIRST_BANK, CONFIG_SYS_JFFS2_NUM_BANKS 1523 Define these for a default partition on a NOR device 1524 1525- FAT(File Allocation Table) filesystem write function support: 1526 CONFIG_FAT_WRITE 1527 1528 Define this to enable support for saving memory data as a 1529 file in FAT formatted partition. 1530 1531 This will also enable the command "fatwrite" enabling the 1532 user to write files to FAT. 1533 1534- FAT(File Allocation Table) filesystem cluster size: 1535 CONFIG_FS_FAT_MAX_CLUSTSIZE 1536 1537 Define the max cluster size for fat operations else 1538 a default value of 65536 will be defined. 1539 1540- Keyboard Support: 1541 See Kconfig help for available keyboard drivers. 1542 1543 CONFIG_KEYBOARD 1544 1545 Define this to enable a custom keyboard support. 1546 This simply calls drv_keyboard_init() which must be 1547 defined in your board-specific files. This option is deprecated 1548 and is only used by novena. For new boards, use driver model 1549 instead. 1550 1551- Video support: 1552 CONFIG_FSL_DIU_FB 1553 Enable the Freescale DIU video driver. Reference boards for 1554 SOCs that have a DIU should define this macro to enable DIU 1555 support, and should also define these other macros: 1556 1557 CONFIG_SYS_DIU_ADDR 1558 CONFIG_VIDEO 1559 CONFIG_CFB_CONSOLE 1560 CONFIG_VIDEO_SW_CURSOR 1561 CONFIG_VGA_AS_SINGLE_DEVICE 1562 CONFIG_VIDEO_LOGO 1563 CONFIG_VIDEO_BMP_LOGO 1564 1565 The DIU driver will look for the 'video-mode' environment 1566 variable, and if defined, enable the DIU as a console during 1567 boot. See the documentation file doc/README.video for a 1568 description of this variable. 1569 1570- LCD Support: CONFIG_LCD 1571 1572 Define this to enable LCD support (for output to LCD 1573 display); also select one of the supported displays 1574 by defining one of these: 1575 1576 CONFIG_ATMEL_LCD: 1577 1578 HITACHI TX09D70VM1CCA, 3.5", 240x320. 1579 1580 CONFIG_NEC_NL6448AC33: 1581 1582 NEC NL6448AC33-18. Active, color, single scan. 1583 1584 CONFIG_NEC_NL6448BC20 1585 1586 NEC NL6448BC20-08. 6.5", 640x480. 1587 Active, color, single scan. 1588 1589 CONFIG_NEC_NL6448BC33_54 1590 1591 NEC NL6448BC33-54. 10.4", 640x480. 1592 Active, color, single scan. 1593 1594 CONFIG_SHARP_16x9 1595 1596 Sharp 320x240. Active, color, single scan. 1597 It isn't 16x9, and I am not sure what it is. 1598 1599 CONFIG_SHARP_LQ64D341 1600 1601 Sharp LQ64D341 display, 640x480. 1602 Active, color, single scan. 1603 1604 CONFIG_HLD1045 1605 1606 HLD1045 display, 640x480. 1607 Active, color, single scan. 1608 1609 CONFIG_OPTREX_BW 1610 1611 Optrex CBL50840-2 NF-FW 99 22 M5 1612 or 1613 Hitachi LMG6912RPFC-00T 1614 or 1615 Hitachi SP14Q002 1616 1617 320x240. Black & white. 1618 1619 CONFIG_LCD_ALIGNMENT 1620 1621 Normally the LCD is page-aligned (typically 4KB). If this is 1622 defined then the LCD will be aligned to this value instead. 1623 For ARM it is sometimes useful to use MMU_SECTION_SIZE 1624 here, since it is cheaper to change data cache settings on 1625 a per-section basis. 1626 1627 1628 CONFIG_LCD_ROTATION 1629 1630 Sometimes, for example if the display is mounted in portrait 1631 mode or even if it's mounted landscape but rotated by 180degree, 1632 we need to rotate our content of the display relative to the 1633 framebuffer, so that user can read the messages which are 1634 printed out. 1635 Once CONFIG_LCD_ROTATION is defined, the lcd_console will be 1636 initialized with a given rotation from "vl_rot" out of 1637 "vidinfo_t" which is provided by the board specific code. 1638 The value for vl_rot is coded as following (matching to 1639 fbcon=rotate:<n> linux-kernel commandline): 1640 0 = no rotation respectively 0 degree 1641 1 = 90 degree rotation 1642 2 = 180 degree rotation 1643 3 = 270 degree rotation 1644 1645 If CONFIG_LCD_ROTATION is not defined, the console will be 1646 initialized with 0degree rotation. 1647 1648 CONFIG_LCD_BMP_RLE8 1649 1650 Support drawing of RLE8-compressed bitmaps on the LCD. 1651 1652 CONFIG_I2C_EDID 1653 1654 Enables an 'i2c edid' command which can read EDID 1655 information over I2C from an attached LCD display. 1656 1657- Splash Screen Support: CONFIG_SPLASH_SCREEN 1658 1659 If this option is set, the environment is checked for 1660 a variable "splashimage". If found, the usual display 1661 of logo, copyright and system information on the LCD 1662 is suppressed and the BMP image at the address 1663 specified in "splashimage" is loaded instead. The 1664 console is redirected to the "nulldev", too. This 1665 allows for a "silent" boot where a splash screen is 1666 loaded very quickly after power-on. 1667 1668 CONFIG_SPLASHIMAGE_GUARD 1669 1670 If this option is set, then U-Boot will prevent the environment 1671 variable "splashimage" from being set to a problematic address 1672 (see doc/README.displaying-bmps). 1673 This option is useful for targets where, due to alignment 1674 restrictions, an improperly aligned BMP image will cause a data 1675 abort. If you think you will not have problems with unaligned 1676 accesses (for example because your toolchain prevents them) 1677 there is no need to set this option. 1678 1679 CONFIG_SPLASH_SCREEN_ALIGN 1680 1681 If this option is set the splash image can be freely positioned 1682 on the screen. Environment variable "splashpos" specifies the 1683 position as "x,y". If a positive number is given it is used as 1684 number of pixel from left/top. If a negative number is given it 1685 is used as number of pixel from right/bottom. You can also 1686 specify 'm' for centering the image. 1687 1688 Example: 1689 setenv splashpos m,m 1690 => image at center of screen 1691 1692 setenv splashpos 30,20 1693 => image at x = 30 and y = 20 1694 1695 setenv splashpos -10,m 1696 => vertically centered image 1697 at x = dspWidth - bmpWidth - 9 1698 1699- Gzip compressed BMP image support: CONFIG_VIDEO_BMP_GZIP 1700 1701 If this option is set, additionally to standard BMP 1702 images, gzipped BMP images can be displayed via the 1703 splashscreen support or the bmp command. 1704 1705- Run length encoded BMP image (RLE8) support: CONFIG_VIDEO_BMP_RLE8 1706 1707 If this option is set, 8-bit RLE compressed BMP images 1708 can be displayed via the splashscreen support or the 1709 bmp command. 1710 1711- Compression support: 1712 CONFIG_GZIP 1713 1714 Enabled by default to support gzip compressed images. 1715 1716 CONFIG_BZIP2 1717 1718 If this option is set, support for bzip2 compressed 1719 images is included. If not, only uncompressed and gzip 1720 compressed images are supported. 1721 1722 NOTE: the bzip2 algorithm requires a lot of RAM, so 1723 the malloc area (as defined by CONFIG_SYS_MALLOC_LEN) should 1724 be at least 4MB. 1725 1726 CONFIG_LZO 1727 1728 If this option is set, support for LZO compressed images 1729 is included. 1730 1731- MII/PHY support: 1732 CONFIG_PHY_ADDR 1733 1734 The address of PHY on MII bus. 1735 1736 CONFIG_PHY_CLOCK_FREQ (ppc4xx) 1737 1738 The clock frequency of the MII bus 1739 1740 CONFIG_PHY_GIGE 1741 1742 If this option is set, support for speed/duplex 1743 detection of gigabit PHY is included. 1744 1745 CONFIG_PHY_RESET_DELAY 1746 1747 Some PHY like Intel LXT971A need extra delay after 1748 reset before any MII register access is possible. 1749 For such PHY, set this option to the usec delay 1750 required. (minimum 300usec for LXT971A) 1751 1752 CONFIG_PHY_CMD_DELAY (ppc4xx) 1753 1754 Some PHY like Intel LXT971A need extra delay after 1755 command issued before MII status register can be read 1756 1757- IP address: 1758 CONFIG_IPADDR 1759 1760 Define a default value for the IP address to use for 1761 the default Ethernet interface, in case this is not 1762 determined through e.g. bootp. 1763 (Environment variable "ipaddr") 1764 1765- Server IP address: 1766 CONFIG_SERVERIP 1767 1768 Defines a default value for the IP address of a TFTP 1769 server to contact when using the "tftboot" command. 1770 (Environment variable "serverip") 1771 1772 CONFIG_KEEP_SERVERADDR 1773 1774 Keeps the server's MAC address, in the env 'serveraddr' 1775 for passing to bootargs (like Linux's netconsole option) 1776 1777- Gateway IP address: 1778 CONFIG_GATEWAYIP 1779 1780 Defines a default value for the IP address of the 1781 default router where packets to other networks are 1782 sent to. 1783 (Environment variable "gatewayip") 1784 1785- Subnet mask: 1786 CONFIG_NETMASK 1787 1788 Defines a default value for the subnet mask (or 1789 routing prefix) which is used to determine if an IP 1790 address belongs to the local subnet or needs to be 1791 forwarded through a router. 1792 (Environment variable "netmask") 1793 1794- Multicast TFTP Mode: 1795 CONFIG_MCAST_TFTP 1796 1797 Defines whether you want to support multicast TFTP as per 1798 rfc-2090; for example to work with atftp. Lets lots of targets 1799 tftp down the same boot image concurrently. Note: the Ethernet 1800 driver in use must provide a function: mcast() to join/leave a 1801 multicast group. 1802 1803- BOOTP Recovery Mode: 1804 CONFIG_BOOTP_RANDOM_DELAY 1805 1806 If you have many targets in a network that try to 1807 boot using BOOTP, you may want to avoid that all 1808 systems send out BOOTP requests at precisely the same 1809 moment (which would happen for instance at recovery 1810 from a power failure, when all systems will try to 1811 boot, thus flooding the BOOTP server. Defining 1812 CONFIG_BOOTP_RANDOM_DELAY causes a random delay to be 1813 inserted before sending out BOOTP requests. The 1814 following delays are inserted then: 1815 1816 1st BOOTP request: delay 0 ... 1 sec 1817 2nd BOOTP request: delay 0 ... 2 sec 1818 3rd BOOTP request: delay 0 ... 4 sec 1819 4th and following 1820 BOOTP requests: delay 0 ... 8 sec 1821 1822 CONFIG_BOOTP_ID_CACHE_SIZE 1823 1824 BOOTP packets are uniquely identified using a 32-bit ID. The 1825 server will copy the ID from client requests to responses and 1826 U-Boot will use this to determine if it is the destination of 1827 an incoming response. Some servers will check that addresses 1828 aren't in use before handing them out (usually using an ARP 1829 ping) and therefore take up to a few hundred milliseconds to 1830 respond. Network congestion may also influence the time it 1831 takes for a response to make it back to the client. If that 1832 time is too long, U-Boot will retransmit requests. In order 1833 to allow earlier responses to still be accepted after these 1834 retransmissions, U-Boot's BOOTP client keeps a small cache of 1835 IDs. The CONFIG_BOOTP_ID_CACHE_SIZE controls the size of this 1836 cache. The default is to keep IDs for up to four outstanding 1837 requests. Increasing this will allow U-Boot to accept offers 1838 from a BOOTP client in networks with unusually high latency. 1839 1840- DHCP Advanced Options: 1841 You can fine tune the DHCP functionality by defining 1842 CONFIG_BOOTP_* symbols: 1843 1844 CONFIG_BOOTP_SUBNETMASK 1845 CONFIG_BOOTP_GATEWAY 1846 CONFIG_BOOTP_HOSTNAME 1847 CONFIG_BOOTP_NISDOMAIN 1848 CONFIG_BOOTP_BOOTPATH 1849 CONFIG_BOOTP_BOOTFILESIZE 1850 CONFIG_BOOTP_DNS 1851 CONFIG_BOOTP_DNS2 1852 CONFIG_BOOTP_SEND_HOSTNAME 1853 CONFIG_BOOTP_NTPSERVER 1854 CONFIG_BOOTP_TIMEOFFSET 1855 CONFIG_BOOTP_VENDOREX 1856 CONFIG_BOOTP_MAY_FAIL 1857 1858 CONFIG_BOOTP_SERVERIP - TFTP server will be the serverip 1859 environment variable, not the BOOTP server. 1860 1861 CONFIG_BOOTP_MAY_FAIL - If the DHCP server is not found 1862 after the configured retry count, the call will fail 1863 instead of starting over. This can be used to fail over 1864 to Link-local IP address configuration if the DHCP server 1865 is not available. 1866 1867 CONFIG_BOOTP_DNS2 - If a DHCP client requests the DNS 1868 serverip from a DHCP server, it is possible that more 1869 than one DNS serverip is offered to the client. 1870 If CONFIG_BOOTP_DNS2 is enabled, the secondary DNS 1871 serverip will be stored in the additional environment 1872 variable "dnsip2". The first DNS serverip is always 1873 stored in the variable "dnsip", when CONFIG_BOOTP_DNS 1874 is defined. 1875 1876 CONFIG_BOOTP_SEND_HOSTNAME - Some DHCP servers are capable 1877 to do a dynamic update of a DNS server. To do this, they 1878 need the hostname of the DHCP requester. 1879 If CONFIG_BOOTP_SEND_HOSTNAME is defined, the content 1880 of the "hostname" environment variable is passed as 1881 option 12 to the DHCP server. 1882 1883 CONFIG_BOOTP_DHCP_REQUEST_DELAY 1884 1885 A 32bit value in microseconds for a delay between 1886 receiving a "DHCP Offer" and sending the "DHCP Request". 1887 This fixes a problem with certain DHCP servers that don't 1888 respond 100% of the time to a "DHCP request". E.g. On an 1889 AT91RM9200 processor running at 180MHz, this delay needed 1890 to be *at least* 15,000 usec before a Windows Server 2003 1891 DHCP server would reply 100% of the time. I recommend at 1892 least 50,000 usec to be safe. The alternative is to hope 1893 that one of the retries will be successful but note that 1894 the DHCP timeout and retry process takes a longer than 1895 this delay. 1896 1897 - Link-local IP address negotiation: 1898 Negotiate with other link-local clients on the local network 1899 for an address that doesn't require explicit configuration. 1900 This is especially useful if a DHCP server cannot be guaranteed 1901 to exist in all environments that the device must operate. 1902 1903 See doc/README.link-local for more information. 1904 1905 - CDP Options: 1906 CONFIG_CDP_DEVICE_ID 1907 1908 The device id used in CDP trigger frames. 1909 1910 CONFIG_CDP_DEVICE_ID_PREFIX 1911 1912 A two character string which is prefixed to the MAC address 1913 of the device. 1914 1915 CONFIG_CDP_PORT_ID 1916 1917 A printf format string which contains the ascii name of 1918 the port. Normally is set to "eth%d" which sets 1919 eth0 for the first Ethernet, eth1 for the second etc. 1920 1921 CONFIG_CDP_CAPABILITIES 1922 1923 A 32bit integer which indicates the device capabilities; 1924 0x00000010 for a normal host which does not forwards. 1925 1926 CONFIG_CDP_VERSION 1927 1928 An ascii string containing the version of the software. 1929 1930 CONFIG_CDP_PLATFORM 1931 1932 An ascii string containing the name of the platform. 1933 1934 CONFIG_CDP_TRIGGER 1935 1936 A 32bit integer sent on the trigger. 1937 1938 CONFIG_CDP_POWER_CONSUMPTION 1939 1940 A 16bit integer containing the power consumption of the 1941 device in .1 of milliwatts. 1942 1943 CONFIG_CDP_APPLIANCE_VLAN_TYPE 1944 1945 A byte containing the id of the VLAN. 1946 1947- Status LED: CONFIG_LED_STATUS 1948 1949 Several configurations allow to display the current 1950 status using a LED. For instance, the LED will blink 1951 fast while running U-Boot code, stop blinking as 1952 soon as a reply to a BOOTP request was received, and 1953 start blinking slow once the Linux kernel is running 1954 (supported by a status LED driver in the Linux 1955 kernel). Defining CONFIG_LED_STATUS enables this 1956 feature in U-Boot. 1957 1958 Additional options: 1959 1960 CONFIG_LED_STATUS_GPIO 1961 The status LED can be connected to a GPIO pin. 1962 In such cases, the gpio_led driver can be used as a 1963 status LED backend implementation. Define CONFIG_LED_STATUS_GPIO 1964 to include the gpio_led driver in the U-Boot binary. 1965 1966 CONFIG_GPIO_LED_INVERTED_TABLE 1967 Some GPIO connected LEDs may have inverted polarity in which 1968 case the GPIO high value corresponds to LED off state and 1969 GPIO low value corresponds to LED on state. 1970 In such cases CONFIG_GPIO_LED_INVERTED_TABLE may be defined 1971 with a list of GPIO LEDs that have inverted polarity. 1972 1973- CAN Support: CONFIG_CAN_DRIVER 1974 1975 Defining CONFIG_CAN_DRIVER enables CAN driver support 1976 on those systems that support this (optional) 1977 feature, like the TQM8xxL modules. 1978 1979- I2C Support: CONFIG_SYS_I2C 1980 1981 This enable the NEW i2c subsystem, and will allow you to use 1982 i2c commands at the u-boot command line (as long as you set 1983 CONFIG_CMD_I2C in CONFIG_COMMANDS) and communicate with i2c 1984 based realtime clock chips or other i2c devices. See 1985 common/cmd_i2c.c for a description of the command line 1986 interface. 1987 1988 ported i2c driver to the new framework: 1989 - drivers/i2c/soft_i2c.c: 1990 - activate first bus with CONFIG_SYS_I2C_SOFT define 1991 CONFIG_SYS_I2C_SOFT_SPEED and CONFIG_SYS_I2C_SOFT_SLAVE 1992 for defining speed and slave address 1993 - activate second bus with I2C_SOFT_DECLARATIONS2 define 1994 CONFIG_SYS_I2C_SOFT_SPEED_2 and CONFIG_SYS_I2C_SOFT_SLAVE_2 1995 for defining speed and slave address 1996 - activate third bus with I2C_SOFT_DECLARATIONS3 define 1997 CONFIG_SYS_I2C_SOFT_SPEED_3 and CONFIG_SYS_I2C_SOFT_SLAVE_3 1998 for defining speed and slave address 1999 - activate fourth bus with I2C_SOFT_DECLARATIONS4 define 2000 CONFIG_SYS_I2C_SOFT_SPEED_4 and CONFIG_SYS_I2C_SOFT_SLAVE_4 2001 for defining speed and slave address 2002 2003 - drivers/i2c/fsl_i2c.c: 2004 - activate i2c driver with CONFIG_SYS_I2C_FSL 2005 define CONFIG_SYS_FSL_I2C_OFFSET for setting the register 2006 offset CONFIG_SYS_FSL_I2C_SPEED for the i2c speed and 2007 CONFIG_SYS_FSL_I2C_SLAVE for the slave addr of the first 2008 bus. 2009 - If your board supports a second fsl i2c bus, define 2010 CONFIG_SYS_FSL_I2C2_OFFSET for the register offset 2011 CONFIG_SYS_FSL_I2C2_SPEED for the speed and 2012 CONFIG_SYS_FSL_I2C2_SLAVE for the slave address of the 2013 second bus. 2014 2015 - drivers/i2c/tegra_i2c.c: 2016 - activate this driver with CONFIG_SYS_I2C_TEGRA 2017 - This driver adds 4 i2c buses with a fix speed from 2018 100000 and the slave addr 0! 2019 2020 - drivers/i2c/ppc4xx_i2c.c 2021 - activate this driver with CONFIG_SYS_I2C_PPC4XX 2022 - CONFIG_SYS_I2C_PPC4XX_CH0 activate hardware channel 0 2023 - CONFIG_SYS_I2C_PPC4XX_CH1 activate hardware channel 1 2024 2025 - drivers/i2c/i2c_mxc.c 2026 - activate this driver with CONFIG_SYS_I2C_MXC 2027 - enable bus 1 with CONFIG_SYS_I2C_MXC_I2C1 2028 - enable bus 2 with CONFIG_SYS_I2C_MXC_I2C2 2029 - enable bus 3 with CONFIG_SYS_I2C_MXC_I2C3 2030 - enable bus 4 with CONFIG_SYS_I2C_MXC_I2C4 2031 - define speed for bus 1 with CONFIG_SYS_MXC_I2C1_SPEED 2032 - define slave for bus 1 with CONFIG_SYS_MXC_I2C1_SLAVE 2033 - define speed for bus 2 with CONFIG_SYS_MXC_I2C2_SPEED 2034 - define slave for bus 2 with CONFIG_SYS_MXC_I2C2_SLAVE 2035 - define speed for bus 3 with CONFIG_SYS_MXC_I2C3_SPEED 2036 - define slave for bus 3 with CONFIG_SYS_MXC_I2C3_SLAVE 2037 - define speed for bus 4 with CONFIG_SYS_MXC_I2C4_SPEED 2038 - define slave for bus 4 with CONFIG_SYS_MXC_I2C4_SLAVE 2039 If those defines are not set, default value is 100000 2040 for speed, and 0 for slave. 2041 2042 - drivers/i2c/rcar_i2c.c: 2043 - activate this driver with CONFIG_SYS_I2C_RCAR 2044 - This driver adds 4 i2c buses 2045 2046 - CONFIG_SYS_RCAR_I2C0_BASE for setting the register channel 0 2047 - CONFIG_SYS_RCAR_I2C0_SPEED for for the speed channel 0 2048 - CONFIG_SYS_RCAR_I2C1_BASE for setting the register channel 1 2049 - CONFIG_SYS_RCAR_I2C1_SPEED for for the speed channel 1 2050 - CONFIG_SYS_RCAR_I2C2_BASE for setting the register channel 2 2051 - CONFIG_SYS_RCAR_I2C2_SPEED for for the speed channel 2 2052 - CONFIG_SYS_RCAR_I2C3_BASE for setting the register channel 3 2053 - CONFIG_SYS_RCAR_I2C3_SPEED for for the speed channel 3 2054 - CONFIF_SYS_RCAR_I2C_NUM_CONTROLLERS for number of i2c buses 2055 2056 - drivers/i2c/sh_i2c.c: 2057 - activate this driver with CONFIG_SYS_I2C_SH 2058 - This driver adds from 2 to 5 i2c buses 2059 2060 - CONFIG_SYS_I2C_SH_BASE0 for setting the register channel 0 2061 - CONFIG_SYS_I2C_SH_SPEED0 for for the speed channel 0 2062 - CONFIG_SYS_I2C_SH_BASE1 for setting the register channel 1 2063 - CONFIG_SYS_I2C_SH_SPEED1 for for the speed channel 1 2064 - CONFIG_SYS_I2C_SH_BASE2 for setting the register channel 2 2065 - CONFIG_SYS_I2C_SH_SPEED2 for for the speed channel 2 2066 - CONFIG_SYS_I2C_SH_BASE3 for setting the register channel 3 2067 - CONFIG_SYS_I2C_SH_SPEED3 for for the speed channel 3 2068 - CONFIG_SYS_I2C_SH_BASE4 for setting the register channel 4 2069 - CONFIG_SYS_I2C_SH_SPEED4 for for the speed channel 4 2070 - CONFIG_SYS_I2C_SH_NUM_CONTROLLERS for number of i2c buses 2071 2072 - drivers/i2c/omap24xx_i2c.c 2073 - activate this driver with CONFIG_SYS_I2C_OMAP24XX 2074 - CONFIG_SYS_OMAP24_I2C_SPEED speed channel 0 2075 - CONFIG_SYS_OMAP24_I2C_SLAVE slave addr channel 0 2076 - CONFIG_SYS_OMAP24_I2C_SPEED1 speed channel 1 2077 - CONFIG_SYS_OMAP24_I2C_SLAVE1 slave addr channel 1 2078 - CONFIG_SYS_OMAP24_I2C_SPEED2 speed channel 2 2079 - CONFIG_SYS_OMAP24_I2C_SLAVE2 slave addr channel 2 2080 - CONFIG_SYS_OMAP24_I2C_SPEED3 speed channel 3 2081 - CONFIG_SYS_OMAP24_I2C_SLAVE3 slave addr channel 3 2082 - CONFIG_SYS_OMAP24_I2C_SPEED4 speed channel 4 2083 - CONFIG_SYS_OMAP24_I2C_SLAVE4 slave addr channel 4 2084 2085 - drivers/i2c/zynq_i2c.c 2086 - activate this driver with CONFIG_SYS_I2C_ZYNQ 2087 - set CONFIG_SYS_I2C_ZYNQ_SPEED for speed setting 2088 - set CONFIG_SYS_I2C_ZYNQ_SLAVE for slave addr 2089 2090 - drivers/i2c/s3c24x0_i2c.c: 2091 - activate this driver with CONFIG_SYS_I2C_S3C24X0 2092 - This driver adds i2c buses (11 for Exynos5250, Exynos5420 2093 9 i2c buses for Exynos4 and 1 for S3C24X0 SoCs from Samsung) 2094 with a fix speed from 100000 and the slave addr 0! 2095 2096 - drivers/i2c/ihs_i2c.c 2097 - activate this driver with CONFIG_SYS_I2C_IHS 2098 - CONFIG_SYS_I2C_IHS_CH0 activate hardware channel 0 2099 - CONFIG_SYS_I2C_IHS_SPEED_0 speed channel 0 2100 - CONFIG_SYS_I2C_IHS_SLAVE_0 slave addr channel 0 2101 - CONFIG_SYS_I2C_IHS_CH1 activate hardware channel 1 2102 - CONFIG_SYS_I2C_IHS_SPEED_1 speed channel 1 2103 - CONFIG_SYS_I2C_IHS_SLAVE_1 slave addr channel 1 2104 - CONFIG_SYS_I2C_IHS_CH2 activate hardware channel 2 2105 - CONFIG_SYS_I2C_IHS_SPEED_2 speed channel 2 2106 - CONFIG_SYS_I2C_IHS_SLAVE_2 slave addr channel 2 2107 - CONFIG_SYS_I2C_IHS_CH3 activate hardware channel 3 2108 - CONFIG_SYS_I2C_IHS_SPEED_3 speed channel 3 2109 - CONFIG_SYS_I2C_IHS_SLAVE_3 slave addr channel 3 2110 - activate dual channel with CONFIG_SYS_I2C_IHS_DUAL 2111 - CONFIG_SYS_I2C_IHS_SPEED_0_1 speed channel 0_1 2112 - CONFIG_SYS_I2C_IHS_SLAVE_0_1 slave addr channel 0_1 2113 - CONFIG_SYS_I2C_IHS_SPEED_1_1 speed channel 1_1 2114 - CONFIG_SYS_I2C_IHS_SLAVE_1_1 slave addr channel 1_1 2115 - CONFIG_SYS_I2C_IHS_SPEED_2_1 speed channel 2_1 2116 - CONFIG_SYS_I2C_IHS_SLAVE_2_1 slave addr channel 2_1 2117 - CONFIG_SYS_I2C_IHS_SPEED_3_1 speed channel 3_1 2118 - CONFIG_SYS_I2C_IHS_SLAVE_3_1 slave addr channel 3_1 2119 2120 additional defines: 2121 2122 CONFIG_SYS_NUM_I2C_BUSES 2123 Hold the number of i2c buses you want to use. 2124 2125 CONFIG_SYS_I2C_DIRECT_BUS 2126 define this, if you don't use i2c muxes on your hardware. 2127 if CONFIG_SYS_I2C_MAX_HOPS is not defined or == 0 you can 2128 omit this define. 2129 2130 CONFIG_SYS_I2C_MAX_HOPS 2131 define how many muxes are maximal consecutively connected 2132 on one i2c bus. If you not use i2c muxes, omit this 2133 define. 2134 2135 CONFIG_SYS_I2C_BUSES 2136 hold a list of buses you want to use, only used if 2137 CONFIG_SYS_I2C_DIRECT_BUS is not defined, for example 2138 a board with CONFIG_SYS_I2C_MAX_HOPS = 1 and 2139 CONFIG_SYS_NUM_I2C_BUSES = 9: 2140 2141 CONFIG_SYS_I2C_BUSES {{0, {I2C_NULL_HOP}}, \ 2142 {0, {{I2C_MUX_PCA9547, 0x70, 1}}}, \ 2143 {0, {{I2C_MUX_PCA9547, 0x70, 2}}}, \ 2144 {0, {{I2C_MUX_PCA9547, 0x70, 3}}}, \ 2145 {0, {{I2C_MUX_PCA9547, 0x70, 4}}}, \ 2146 {0, {{I2C_MUX_PCA9547, 0x70, 5}}}, \ 2147 {1, {I2C_NULL_HOP}}, \ 2148 {1, {{I2C_MUX_PCA9544, 0x72, 1}}}, \ 2149 {1, {{I2C_MUX_PCA9544, 0x72, 2}}}, \ 2150 } 2151 2152 which defines 2153 bus 0 on adapter 0 without a mux 2154 bus 1 on adapter 0 with a PCA9547 on address 0x70 port 1 2155 bus 2 on adapter 0 with a PCA9547 on address 0x70 port 2 2156 bus 3 on adapter 0 with a PCA9547 on address 0x70 port 3 2157 bus 4 on adapter 0 with a PCA9547 on address 0x70 port 4 2158 bus 5 on adapter 0 with a PCA9547 on address 0x70 port 5 2159 bus 6 on adapter 1 without a mux 2160 bus 7 on adapter 1 with a PCA9544 on address 0x72 port 1 2161 bus 8 on adapter 1 with a PCA9544 on address 0x72 port 2 2162 2163 If you do not have i2c muxes on your board, omit this define. 2164 2165- Legacy I2C Support: 2166 If you use the software i2c interface (CONFIG_SYS_I2C_SOFT) 2167 then the following macros need to be defined (examples are 2168 from include/configs/lwmon.h): 2169 2170 I2C_INIT 2171 2172 (Optional). Any commands necessary to enable the I2C 2173 controller or configure ports. 2174 2175 eg: #define I2C_INIT (immr->im_cpm.cp_pbdir |= PB_SCL) 2176 2177 I2C_PORT 2178 2179 (Only for MPC8260 CPU). The I/O port to use (the code 2180 assumes both bits are on the same port). Valid values 2181 are 0..3 for ports A..D. 2182 2183 I2C_ACTIVE 2184 2185 The code necessary to make the I2C data line active 2186 (driven). If the data line is open collector, this 2187 define can be null. 2188 2189 eg: #define I2C_ACTIVE (immr->im_cpm.cp_pbdir |= PB_SDA) 2190 2191 I2C_TRISTATE 2192 2193 The code necessary to make the I2C data line tri-stated 2194 (inactive). If the data line is open collector, this 2195 define can be null. 2196 2197 eg: #define I2C_TRISTATE (immr->im_cpm.cp_pbdir &= ~PB_SDA) 2198 2199 I2C_READ 2200 2201 Code that returns true if the I2C data line is high, 2202 false if it is low. 2203 2204 eg: #define I2C_READ ((immr->im_cpm.cp_pbdat & PB_SDA) != 0) 2205 2206 I2C_SDA(bit) 2207 2208 If <bit> is true, sets the I2C data line high. If it 2209 is false, it clears it (low). 2210 2211 eg: #define I2C_SDA(bit) \ 2212 if(bit) immr->im_cpm.cp_pbdat |= PB_SDA; \ 2213 else immr->im_cpm.cp_pbdat &= ~PB_SDA 2214 2215 I2C_SCL(bit) 2216 2217 If <bit> is true, sets the I2C clock line high. If it 2218 is false, it clears it (low). 2219 2220 eg: #define I2C_SCL(bit) \ 2221 if(bit) immr->im_cpm.cp_pbdat |= PB_SCL; \ 2222 else immr->im_cpm.cp_pbdat &= ~PB_SCL 2223 2224 I2C_DELAY 2225 2226 This delay is invoked four times per clock cycle so this 2227 controls the rate of data transfer. The data rate thus 2228 is 1 / (I2C_DELAY * 4). Often defined to be something 2229 like: 2230 2231 #define I2C_DELAY udelay(2) 2232 2233 CONFIG_SOFT_I2C_GPIO_SCL / CONFIG_SOFT_I2C_GPIO_SDA 2234 2235 If your arch supports the generic GPIO framework (asm/gpio.h), 2236 then you may alternatively define the two GPIOs that are to be 2237 used as SCL / SDA. Any of the previous I2C_xxx macros will 2238 have GPIO-based defaults assigned to them as appropriate. 2239 2240 You should define these to the GPIO value as given directly to 2241 the generic GPIO functions. 2242 2243 CONFIG_SYS_I2C_INIT_BOARD 2244 2245 When a board is reset during an i2c bus transfer 2246 chips might think that the current transfer is still 2247 in progress. On some boards it is possible to access 2248 the i2c SCLK line directly, either by using the 2249 processor pin as a GPIO or by having a second pin 2250 connected to the bus. If this option is defined a 2251 custom i2c_init_board() routine in boards/xxx/board.c 2252 is run early in the boot sequence. 2253 2254 CONFIG_I2C_MULTI_BUS 2255 2256 This option allows the use of multiple I2C buses, each of which 2257 must have a controller. At any point in time, only one bus is 2258 active. To switch to a different bus, use the 'i2c dev' command. 2259 Note that bus numbering is zero-based. 2260 2261 CONFIG_SYS_I2C_NOPROBES 2262 2263 This option specifies a list of I2C devices that will be skipped 2264 when the 'i2c probe' command is issued. If CONFIG_I2C_MULTI_BUS 2265 is set, specify a list of bus-device pairs. Otherwise, specify 2266 a 1D array of device addresses 2267 2268 e.g. 2269 #undef CONFIG_I2C_MULTI_BUS 2270 #define CONFIG_SYS_I2C_NOPROBES {0x50,0x68} 2271 2272 will skip addresses 0x50 and 0x68 on a board with one I2C bus 2273 2274 #define CONFIG_I2C_MULTI_BUS 2275 #define CONFIG_SYS_I2C_NOPROBES {{0,0x50},{0,0x68},{1,0x54}} 2276 2277 will skip addresses 0x50 and 0x68 on bus 0 and address 0x54 on bus 1 2278 2279 CONFIG_SYS_SPD_BUS_NUM 2280 2281 If defined, then this indicates the I2C bus number for DDR SPD. 2282 If not defined, then U-Boot assumes that SPD is on I2C bus 0. 2283 2284 CONFIG_SYS_RTC_BUS_NUM 2285 2286 If defined, then this indicates the I2C bus number for the RTC. 2287 If not defined, then U-Boot assumes that RTC is on I2C bus 0. 2288 2289 CONFIG_SOFT_I2C_READ_REPEATED_START 2290 2291 defining this will force the i2c_read() function in 2292 the soft_i2c driver to perform an I2C repeated start 2293 between writing the address pointer and reading the 2294 data. If this define is omitted the default behaviour 2295 of doing a stop-start sequence will be used. Most I2C 2296 devices can use either method, but some require one or 2297 the other. 2298 2299- SPI Support: CONFIG_SPI 2300 2301 Enables SPI driver (so far only tested with 2302 SPI EEPROM, also an instance works with Crystal A/D and 2303 D/As on the SACSng board) 2304 2305 CONFIG_SH_SPI 2306 2307 Enables the driver for SPI controller on SuperH. Currently 2308 only SH7757 is supported. 2309 2310 CONFIG_SOFT_SPI 2311 2312 Enables a software (bit-bang) SPI driver rather than 2313 using hardware support. This is a general purpose 2314 driver that only requires three general I/O port pins 2315 (two outputs, one input) to function. If this is 2316 defined, the board configuration must define several 2317 SPI configuration items (port pins to use, etc). For 2318 an example, see include/configs/sacsng.h. 2319 2320 CONFIG_HARD_SPI 2321 2322 Enables a hardware SPI driver for general-purpose reads 2323 and writes. As with CONFIG_SOFT_SPI, the board configuration 2324 must define a list of chip-select function pointers. 2325 Currently supported on some MPC8xxx processors. For an 2326 example, see include/configs/mpc8349emds.h. 2327 2328 CONFIG_MXC_SPI 2329 2330 Enables the driver for the SPI controllers on i.MX and MXC 2331 SoCs. Currently i.MX31/35/51 are supported. 2332 2333 CONFIG_SYS_SPI_MXC_WAIT 2334 Timeout for waiting until spi transfer completed. 2335 default: (CONFIG_SYS_HZ/100) /* 10 ms */ 2336 2337- FPGA Support: CONFIG_FPGA 2338 2339 Enables FPGA subsystem. 2340 2341 CONFIG_FPGA_<vendor> 2342 2343 Enables support for specific chip vendors. 2344 (ALTERA, XILINX) 2345 2346 CONFIG_FPGA_<family> 2347 2348 Enables support for FPGA family. 2349 (SPARTAN2, SPARTAN3, VIRTEX2, CYCLONE2, ACEX1K, ACEX) 2350 2351 CONFIG_FPGA_COUNT 2352 2353 Specify the number of FPGA devices to support. 2354 2355 CONFIG_SYS_FPGA_PROG_FEEDBACK 2356 2357 Enable printing of hash marks during FPGA configuration. 2358 2359 CONFIG_SYS_FPGA_CHECK_BUSY 2360 2361 Enable checks on FPGA configuration interface busy 2362 status by the configuration function. This option 2363 will require a board or device specific function to 2364 be written. 2365 2366 CONFIG_FPGA_DELAY 2367 2368 If defined, a function that provides delays in the FPGA 2369 configuration driver. 2370 2371 CONFIG_SYS_FPGA_CHECK_CTRLC 2372 Allow Control-C to interrupt FPGA configuration 2373 2374 CONFIG_SYS_FPGA_CHECK_ERROR 2375 2376 Check for configuration errors during FPGA bitfile 2377 loading. For example, abort during Virtex II 2378 configuration if the INIT_B line goes low (which 2379 indicated a CRC error). 2380 2381 CONFIG_SYS_FPGA_WAIT_INIT 2382 2383 Maximum time to wait for the INIT_B line to de-assert 2384 after PROB_B has been de-asserted during a Virtex II 2385 FPGA configuration sequence. The default time is 500 2386 ms. 2387 2388 CONFIG_SYS_FPGA_WAIT_BUSY 2389 2390 Maximum time to wait for BUSY to de-assert during 2391 Virtex II FPGA configuration. The default is 5 ms. 2392 2393 CONFIG_SYS_FPGA_WAIT_CONFIG 2394 2395 Time to wait after FPGA configuration. The default is 2396 200 ms. 2397 2398- Configuration Management: 2399 CONFIG_BUILD_TARGET 2400 2401 Some SoCs need special image types (e.g. U-Boot binary 2402 with a special header) as build targets. By defining 2403 CONFIG_BUILD_TARGET in the SoC / board header, this 2404 special image will be automatically built upon calling 2405 make / buildman. 2406 2407 CONFIG_IDENT_STRING 2408 2409 If defined, this string will be added to the U-Boot 2410 version information (U_BOOT_VERSION) 2411 2412- Vendor Parameter Protection: 2413 2414 U-Boot considers the values of the environment 2415 variables "serial#" (Board Serial Number) and 2416 "ethaddr" (Ethernet Address) to be parameters that 2417 are set once by the board vendor / manufacturer, and 2418 protects these variables from casual modification by 2419 the user. Once set, these variables are read-only, 2420 and write or delete attempts are rejected. You can 2421 change this behaviour: 2422 2423 If CONFIG_ENV_OVERWRITE is #defined in your config 2424 file, the write protection for vendor parameters is 2425 completely disabled. Anybody can change or delete 2426 these parameters. 2427 2428 Alternatively, if you define _both_ an ethaddr in the 2429 default env _and_ CONFIG_OVERWRITE_ETHADDR_ONCE, a default 2430 Ethernet address is installed in the environment, 2431 which can be changed exactly ONCE by the user. [The 2432 serial# is unaffected by this, i. e. it remains 2433 read-only.] 2434 2435 The same can be accomplished in a more flexible way 2436 for any variable by configuring the type of access 2437 to allow for those variables in the ".flags" variable 2438 or define CONFIG_ENV_FLAGS_LIST_STATIC. 2439 2440- Protected RAM: 2441 CONFIG_PRAM 2442 2443 Define this variable to enable the reservation of 2444 "protected RAM", i. e. RAM which is not overwritten 2445 by U-Boot. Define CONFIG_PRAM to hold the number of 2446 kB you want to reserve for pRAM. You can overwrite 2447 this default value by defining an environment 2448 variable "pram" to the number of kB you want to 2449 reserve. Note that the board info structure will 2450 still show the full amount of RAM. If pRAM is 2451 reserved, a new environment variable "mem" will 2452 automatically be defined to hold the amount of 2453 remaining RAM in a form that can be passed as boot 2454 argument to Linux, for instance like that: 2455 2456 setenv bootargs ... mem=\${mem} 2457 saveenv 2458 2459 This way you can tell Linux not to use this memory, 2460 either, which results in a memory region that will 2461 not be affected by reboots. 2462 2463 *WARNING* If your board configuration uses automatic 2464 detection of the RAM size, you must make sure that 2465 this memory test is non-destructive. So far, the 2466 following board configurations are known to be 2467 "pRAM-clean": 2468 2469 IVMS8, IVML24, SPD8xx, TQM8xxL, 2470 HERMES, IP860, RPXlite, LWMON, 2471 FLAGADM, TQM8260 2472 2473- Access to physical memory region (> 4GB) 2474 Some basic support is provided for operations on memory not 2475 normally accessible to U-Boot - e.g. some architectures 2476 support access to more than 4GB of memory on 32-bit 2477 machines using physical address extension or similar. 2478 Define CONFIG_PHYSMEM to access this basic support, which 2479 currently only supports clearing the memory. 2480 2481- Error Recovery: 2482 CONFIG_PANIC_HANG 2483 2484 Define this variable to stop the system in case of a 2485 fatal error, so that you have to reset it manually. 2486 This is probably NOT a good idea for an embedded 2487 system where you want the system to reboot 2488 automatically as fast as possible, but it may be 2489 useful during development since you can try to debug 2490 the conditions that lead to the situation. 2491 2492 CONFIG_NET_RETRY_COUNT 2493 2494 This variable defines the number of retries for 2495 network operations like ARP, RARP, TFTP, or BOOTP 2496 before giving up the operation. If not defined, a 2497 default value of 5 is used. 2498 2499 CONFIG_ARP_TIMEOUT 2500 2501 Timeout waiting for an ARP reply in milliseconds. 2502 2503 CONFIG_NFS_TIMEOUT 2504 2505 Timeout in milliseconds used in NFS protocol. 2506 If you encounter "ERROR: Cannot umount" in nfs command, 2507 try longer timeout such as 2508 #define CONFIG_NFS_TIMEOUT 10000UL 2509 2510- Command Interpreter: 2511 CONFIG_AUTO_COMPLETE 2512 2513 Enable auto completion of commands using TAB. 2514 2515 CONFIG_SYS_PROMPT_HUSH_PS2 2516 2517 This defines the secondary prompt string, which is 2518 printed when the command interpreter needs more input 2519 to complete a command. Usually "> ". 2520 2521 Note: 2522 2523 In the current implementation, the local variables 2524 space and global environment variables space are 2525 separated. Local variables are those you define by 2526 simply typing `name=value'. To access a local 2527 variable later on, you have write `$name' or 2528 `${name}'; to execute the contents of a variable 2529 directly type `$name' at the command prompt. 2530 2531 Global environment variables are those you use 2532 setenv/printenv to work with. To run a command stored 2533 in such a variable, you need to use the run command, 2534 and you must not use the '$' sign to access them. 2535 2536 To store commands and special characters in a 2537 variable, please use double quotation marks 2538 surrounding the whole text of the variable, instead 2539 of the backslashes before semicolons and special 2540 symbols. 2541 2542- Command Line Editing and History: 2543 CONFIG_CMDLINE_EDITING 2544 2545 Enable editing and History functions for interactive 2546 command line input operations 2547 2548- Command Line PS1/PS2 support: 2549 CONFIG_CMDLINE_PS_SUPPORT 2550 2551 Enable support for changing the command prompt string 2552 at run-time. Only static string is supported so far. 2553 The string is obtained from environment variables PS1 2554 and PS2. 2555 2556- Default Environment: 2557 CONFIG_EXTRA_ENV_SETTINGS 2558 2559 Define this to contain any number of null terminated 2560 strings (variable = value pairs) that will be part of 2561 the default environment compiled into the boot image. 2562 2563 For example, place something like this in your 2564 board's config file: 2565 2566 #define CONFIG_EXTRA_ENV_SETTINGS \ 2567 "myvar1=value1\0" \ 2568 "myvar2=value2\0" 2569 2570 Warning: This method is based on knowledge about the 2571 internal format how the environment is stored by the 2572 U-Boot code. This is NOT an official, exported 2573 interface! Although it is unlikely that this format 2574 will change soon, there is no guarantee either. 2575 You better know what you are doing here. 2576 2577 Note: overly (ab)use of the default environment is 2578 discouraged. Make sure to check other ways to preset 2579 the environment like the "source" command or the 2580 boot command first. 2581 2582 CONFIG_ENV_VARS_UBOOT_CONFIG 2583 2584 Define this in order to add variables describing the 2585 U-Boot build configuration to the default environment. 2586 These will be named arch, cpu, board, vendor, and soc. 2587 2588 Enabling this option will cause the following to be defined: 2589 2590 - CONFIG_SYS_ARCH 2591 - CONFIG_SYS_CPU 2592 - CONFIG_SYS_BOARD 2593 - CONFIG_SYS_VENDOR 2594 - CONFIG_SYS_SOC 2595 2596 CONFIG_ENV_VARS_UBOOT_RUNTIME_CONFIG 2597 2598 Define this in order to add variables describing certain 2599 run-time determined information about the hardware to the 2600 environment. These will be named board_name, board_rev. 2601 2602 CONFIG_DELAY_ENVIRONMENT 2603 2604 Normally the environment is loaded when the board is 2605 initialised so that it is available to U-Boot. This inhibits 2606 that so that the environment is not available until 2607 explicitly loaded later by U-Boot code. With CONFIG_OF_CONTROL 2608 this is instead controlled by the value of 2609 /config/load-environment. 2610 2611- DataFlash Support: 2612 CONFIG_HAS_DATAFLASH 2613 2614 Defining this option enables DataFlash features and 2615 allows to read/write in Dataflash via the standard 2616 commands cp, md... 2617 2618- Serial Flash support 2619 CONFIG_CMD_SF 2620 2621 Defining this option enables SPI flash commands 2622 'sf probe/read/write/erase/update'. 2623 2624 Usage requires an initial 'probe' to define the serial 2625 flash parameters, followed by read/write/erase/update 2626 commands. 2627 2628 The following defaults may be provided by the platform 2629 to handle the common case when only a single serial 2630 flash is present on the system. 2631 2632 CONFIG_SF_DEFAULT_BUS Bus identifier 2633 CONFIG_SF_DEFAULT_CS Chip-select 2634 CONFIG_SF_DEFAULT_MODE (see include/spi.h) 2635 CONFIG_SF_DEFAULT_SPEED in Hz 2636 2637 CONFIG_CMD_SF_TEST 2638 2639 Define this option to include a destructive SPI flash 2640 test ('sf test'). 2641 2642 CONFIG_SF_DUAL_FLASH Dual flash memories 2643 2644 Define this option to use dual flash support where two flash 2645 memories can be connected with a given cs line. 2646 Currently Xilinx Zynq qspi supports these type of connections. 2647 2648- SystemACE Support: 2649 CONFIG_SYSTEMACE 2650 2651 Adding this option adds support for Xilinx SystemACE 2652 chips attached via some sort of local bus. The address 2653 of the chip must also be defined in the 2654 CONFIG_SYS_SYSTEMACE_BASE macro. For example: 2655 2656 #define CONFIG_SYSTEMACE 2657 #define CONFIG_SYS_SYSTEMACE_BASE 0xf0000000 2658 2659 When SystemACE support is added, the "ace" device type 2660 becomes available to the fat commands, i.e. fatls. 2661 2662- TFTP Fixed UDP Port: 2663 CONFIG_TFTP_PORT 2664 2665 If this is defined, the environment variable tftpsrcp 2666 is used to supply the TFTP UDP source port value. 2667 If tftpsrcp isn't defined, the normal pseudo-random port 2668 number generator is used. 2669 2670 Also, the environment variable tftpdstp is used to supply 2671 the TFTP UDP destination port value. If tftpdstp isn't 2672 defined, the normal port 69 is used. 2673 2674 The purpose for tftpsrcp is to allow a TFTP server to 2675 blindly start the TFTP transfer using the pre-configured 2676 target IP address and UDP port. This has the effect of 2677 "punching through" the (Windows XP) firewall, allowing 2678 the remainder of the TFTP transfer to proceed normally. 2679 A better solution is to properly configure the firewall, 2680 but sometimes that is not allowed. 2681 2682- Hashing support: 2683 CONFIG_HASH_VERIFY 2684 2685 Enable the hash verify command (hash -v). This adds to code 2686 size a little. 2687 2688 Note: There is also a sha1sum command, which should perhaps 2689 be deprecated in favour of 'hash sha1'. 2690 2691- bootcount support: 2692 CONFIG_BOOTCOUNT_LIMIT 2693 2694 This enables the bootcounter support, see: 2695 http://www.denx.de/wiki/DULG/UBootBootCountLimit 2696 2697 CONFIG_AT91SAM9XE 2698 enable special bootcounter support on at91sam9xe based boards. 2699 CONFIG_SOC_DA8XX 2700 enable special bootcounter support on da850 based boards. 2701 CONFIG_BOOTCOUNT_RAM 2702 enable support for the bootcounter in RAM 2703 CONFIG_BOOTCOUNT_I2C 2704 enable support for the bootcounter on an i2c (like RTC) device. 2705 CONFIG_SYS_I2C_RTC_ADDR = i2c chip address 2706 CONFIG_SYS_BOOTCOUNT_ADDR = i2c addr which is used for 2707 the bootcounter. 2708 CONFIG_BOOTCOUNT_ALEN = address len 2709 2710- Show boot progress: 2711 CONFIG_SHOW_BOOT_PROGRESS 2712 2713 Defining this option allows to add some board- 2714 specific code (calling a user-provided function 2715 "show_boot_progress(int)") that enables you to show 2716 the system's boot progress on some display (for 2717 example, some LED's) on your board. At the moment, 2718 the following checkpoints are implemented: 2719 2720 2721Legacy uImage format: 2722 2723 Arg Where When 2724 1 common/cmd_bootm.c before attempting to boot an image 2725 -1 common/cmd_bootm.c Image header has bad magic number 2726 2 common/cmd_bootm.c Image header has correct magic number 2727 -2 common/cmd_bootm.c Image header has bad checksum 2728 3 common/cmd_bootm.c Image header has correct checksum 2729 -3 common/cmd_bootm.c Image data has bad checksum 2730 4 common/cmd_bootm.c Image data has correct checksum 2731 -4 common/cmd_bootm.c Image is for unsupported architecture 2732 5 common/cmd_bootm.c Architecture check OK 2733 -5 common/cmd_bootm.c Wrong Image Type (not kernel, multi) 2734 6 common/cmd_bootm.c Image Type check OK 2735 -6 common/cmd_bootm.c gunzip uncompression error 2736 -7 common/cmd_bootm.c Unimplemented compression type 2737 7 common/cmd_bootm.c Uncompression OK 2738 8 common/cmd_bootm.c No uncompress/copy overwrite error 2739 -9 common/cmd_bootm.c Unsupported OS (not Linux, BSD, VxWorks, QNX) 2740 2741 9 common/image.c Start initial ramdisk verification 2742 -10 common/image.c Ramdisk header has bad magic number 2743 -11 common/image.c Ramdisk header has bad checksum 2744 10 common/image.c Ramdisk header is OK 2745 -12 common/image.c Ramdisk data has bad checksum 2746 11 common/image.c Ramdisk data has correct checksum 2747 12 common/image.c Ramdisk verification complete, start loading 2748 -13 common/image.c Wrong Image Type (not PPC Linux ramdisk) 2749 13 common/image.c Start multifile image verification 2750 14 common/image.c No initial ramdisk, no multifile, continue. 2751 2752 15 arch/<arch>/lib/bootm.c All preparation done, transferring control to OS 2753 2754 -30 arch/powerpc/lib/board.c Fatal error, hang the system 2755 -31 post/post.c POST test failed, detected by post_output_backlog() 2756 -32 post/post.c POST test failed, detected by post_run_single() 2757 2758 34 common/cmd_doc.c before loading a Image from a DOC device 2759 -35 common/cmd_doc.c Bad usage of "doc" command 2760 35 common/cmd_doc.c correct usage of "doc" command 2761 -36 common/cmd_doc.c No boot device 2762 36 common/cmd_doc.c correct boot device 2763 -37 common/cmd_doc.c Unknown Chip ID on boot device 2764 37 common/cmd_doc.c correct chip ID found, device available 2765 -38 common/cmd_doc.c Read Error on boot device 2766 38 common/cmd_doc.c reading Image header from DOC device OK 2767 -39 common/cmd_doc.c Image header has bad magic number 2768 39 common/cmd_doc.c Image header has correct magic number 2769 -40 common/cmd_doc.c Error reading Image from DOC device 2770 40 common/cmd_doc.c Image header has correct magic number 2771 41 common/cmd_ide.c before loading a Image from a IDE device 2772 -42 common/cmd_ide.c Bad usage of "ide" command 2773 42 common/cmd_ide.c correct usage of "ide" command 2774 -43 common/cmd_ide.c No boot device 2775 43 common/cmd_ide.c boot device found 2776 -44 common/cmd_ide.c Device not available 2777 44 common/cmd_ide.c Device available 2778 -45 common/cmd_ide.c wrong partition selected 2779 45 common/cmd_ide.c partition selected 2780 -46 common/cmd_ide.c Unknown partition table 2781 46 common/cmd_ide.c valid partition table found 2782 -47 common/cmd_ide.c Invalid partition type 2783 47 common/cmd_ide.c correct partition type 2784 -48 common/cmd_ide.c Error reading Image Header on boot device 2785 48 common/cmd_ide.c reading Image Header from IDE device OK 2786 -49 common/cmd_ide.c Image header has bad magic number 2787 49 common/cmd_ide.c Image header has correct magic number 2788 -50 common/cmd_ide.c Image header has bad checksum 2789 50 common/cmd_ide.c Image header has correct checksum 2790 -51 common/cmd_ide.c Error reading Image from IDE device 2791 51 common/cmd_ide.c reading Image from IDE device OK 2792 52 common/cmd_nand.c before loading a Image from a NAND device 2793 -53 common/cmd_nand.c Bad usage of "nand" command 2794 53 common/cmd_nand.c correct usage of "nand" command 2795 -54 common/cmd_nand.c No boot device 2796 54 common/cmd_nand.c boot device found 2797 -55 common/cmd_nand.c Unknown Chip ID on boot device 2798 55 common/cmd_nand.c correct chip ID found, device available 2799 -56 common/cmd_nand.c Error reading Image Header on boot device 2800 56 common/cmd_nand.c reading Image Header from NAND device OK 2801 -57 common/cmd_nand.c Image header has bad magic number 2802 57 common/cmd_nand.c Image header has correct magic number 2803 -58 common/cmd_nand.c Error reading Image from NAND device 2804 58 common/cmd_nand.c reading Image from NAND device OK 2805 2806 -60 common/env_common.c Environment has a bad CRC, using default 2807 2808 64 net/eth.c starting with Ethernet configuration. 2809 -64 net/eth.c no Ethernet found. 2810 65 net/eth.c Ethernet found. 2811 2812 -80 common/cmd_net.c usage wrong 2813 80 common/cmd_net.c before calling net_loop() 2814 -81 common/cmd_net.c some error in net_loop() occurred 2815 81 common/cmd_net.c net_loop() back without error 2816 -82 common/cmd_net.c size == 0 (File with size 0 loaded) 2817 82 common/cmd_net.c trying automatic boot 2818 83 common/cmd_net.c running "source" command 2819 -83 common/cmd_net.c some error in automatic boot or "source" command 2820 84 common/cmd_net.c end without errors 2821 2822FIT uImage format: 2823 2824 Arg Where When 2825 100 common/cmd_bootm.c Kernel FIT Image has correct format 2826 -100 common/cmd_bootm.c Kernel FIT Image has incorrect format 2827 101 common/cmd_bootm.c No Kernel subimage unit name, using configuration 2828 -101 common/cmd_bootm.c Can't get configuration for kernel subimage 2829 102 common/cmd_bootm.c Kernel unit name specified 2830 -103 common/cmd_bootm.c Can't get kernel subimage node offset 2831 103 common/cmd_bootm.c Found configuration node 2832 104 common/cmd_bootm.c Got kernel subimage node offset 2833 -104 common/cmd_bootm.c Kernel subimage hash verification failed 2834 105 common/cmd_bootm.c Kernel subimage hash verification OK 2835 -105 common/cmd_bootm.c Kernel subimage is for unsupported architecture 2836 106 common/cmd_bootm.c Architecture check OK 2837 -106 common/cmd_bootm.c Kernel subimage has wrong type 2838 107 common/cmd_bootm.c Kernel subimage type OK 2839 -107 common/cmd_bootm.c Can't get kernel subimage data/size 2840 108 common/cmd_bootm.c Got kernel subimage data/size 2841 -108 common/cmd_bootm.c Wrong image type (not legacy, FIT) 2842 -109 common/cmd_bootm.c Can't get kernel subimage type 2843 -110 common/cmd_bootm.c Can't get kernel subimage comp 2844 -111 common/cmd_bootm.c Can't get kernel subimage os 2845 -112 common/cmd_bootm.c Can't get kernel subimage load address 2846 -113 common/cmd_bootm.c Image uncompress/copy overwrite error 2847 2848 120 common/image.c Start initial ramdisk verification 2849 -120 common/image.c Ramdisk FIT image has incorrect format 2850 121 common/image.c Ramdisk FIT image has correct format 2851 122 common/image.c No ramdisk subimage unit name, using configuration 2852 -122 common/image.c Can't get configuration for ramdisk subimage 2853 123 common/image.c Ramdisk unit name specified 2854 -124 common/image.c Can't get ramdisk subimage node offset 2855 125 common/image.c Got ramdisk subimage node offset 2856 -125 common/image.c Ramdisk subimage hash verification failed 2857 126 common/image.c Ramdisk subimage hash verification OK 2858 -126 common/image.c Ramdisk subimage for unsupported architecture 2859 127 common/image.c Architecture check OK 2860 -127 common/image.c Can't get ramdisk subimage data/size 2861 128 common/image.c Got ramdisk subimage data/size 2862 129 common/image.c Can't get ramdisk load address 2863 -129 common/image.c Got ramdisk load address 2864 2865 -130 common/cmd_doc.c Incorrect FIT image format 2866 131 common/cmd_doc.c FIT image format OK 2867 2868 -140 common/cmd_ide.c Incorrect FIT image format 2869 141 common/cmd_ide.c FIT image format OK 2870 2871 -150 common/cmd_nand.c Incorrect FIT image format 2872 151 common/cmd_nand.c FIT image format OK 2873 2874- legacy image format: 2875 CONFIG_IMAGE_FORMAT_LEGACY 2876 enables the legacy image format support in U-Boot. 2877 2878 Default: 2879 enabled if CONFIG_FIT_SIGNATURE is not defined. 2880 2881 CONFIG_DISABLE_IMAGE_LEGACY 2882 disable the legacy image format 2883 2884 This define is introduced, as the legacy image format is 2885 enabled per default for backward compatibility. 2886 2887- Standalone program support: 2888 CONFIG_STANDALONE_LOAD_ADDR 2889 2890 This option defines a board specific value for the 2891 address where standalone program gets loaded, thus 2892 overwriting the architecture dependent default 2893 settings. 2894 2895- Frame Buffer Address: 2896 CONFIG_FB_ADDR 2897 2898 Define CONFIG_FB_ADDR if you want to use specific 2899 address for frame buffer. This is typically the case 2900 when using a graphics controller has separate video 2901 memory. U-Boot will then place the frame buffer at 2902 the given address instead of dynamically reserving it 2903 in system RAM by calling lcd_setmem(), which grabs 2904 the memory for the frame buffer depending on the 2905 configured panel size. 2906 2907 Please see board_init_f function. 2908 2909- Automatic software updates via TFTP server 2910 CONFIG_UPDATE_TFTP 2911 CONFIG_UPDATE_TFTP_CNT_MAX 2912 CONFIG_UPDATE_TFTP_MSEC_MAX 2913 2914 These options enable and control the auto-update feature; 2915 for a more detailed description refer to doc/README.update. 2916 2917- MTD Support (mtdparts command, UBI support) 2918 CONFIG_MTD_DEVICE 2919 2920 Adds the MTD device infrastructure from the Linux kernel. 2921 Needed for mtdparts command support. 2922 2923 CONFIG_MTD_PARTITIONS 2924 2925 Adds the MTD partitioning infrastructure from the Linux 2926 kernel. Needed for UBI support. 2927 2928- UBI support 2929 CONFIG_CMD_UBI 2930 2931 Adds commands for interacting with MTD partitions formatted 2932 with the UBI flash translation layer 2933 2934 Requires also defining CONFIG_RBTREE 2935 2936 CONFIG_UBI_SILENCE_MSG 2937 2938 Make the verbose messages from UBI stop printing. This leaves 2939 warnings and errors enabled. 2940 2941 2942 CONFIG_MTD_UBI_WL_THRESHOLD 2943 This parameter defines the maximum difference between the highest 2944 erase counter value and the lowest erase counter value of eraseblocks 2945 of UBI devices. When this threshold is exceeded, UBI starts performing 2946 wear leveling by means of moving data from eraseblock with low erase 2947 counter to eraseblocks with high erase counter. 2948 2949 The default value should be OK for SLC NAND flashes, NOR flashes and 2950 other flashes which have eraseblock life-cycle 100000 or more. 2951 However, in case of MLC NAND flashes which typically have eraseblock 2952 life-cycle less than 10000, the threshold should be lessened (e.g., 2953 to 128 or 256, although it does not have to be power of 2). 2954 2955 default: 4096 2956 2957 CONFIG_MTD_UBI_BEB_LIMIT 2958 This option specifies the maximum bad physical eraseblocks UBI 2959 expects on the MTD device (per 1024 eraseblocks). If the 2960 underlying flash does not admit of bad eraseblocks (e.g. NOR 2961 flash), this value is ignored. 2962 2963 NAND datasheets often specify the minimum and maximum NVM 2964 (Number of Valid Blocks) for the flashes' endurance lifetime. 2965 The maximum expected bad eraseblocks per 1024 eraseblocks 2966 then can be calculated as "1024 * (1 - MinNVB / MaxNVB)", 2967 which gives 20 for most NANDs (MaxNVB is basically the total 2968 count of eraseblocks on the chip). 2969 2970 To put it differently, if this value is 20, UBI will try to 2971 reserve about 1.9% of physical eraseblocks for bad blocks 2972 handling. And that will be 1.9% of eraseblocks on the entire 2973 NAND chip, not just the MTD partition UBI attaches. This means 2974 that if you have, say, a NAND flash chip admits maximum 40 bad 2975 eraseblocks, and it is split on two MTD partitions of the same 2976 size, UBI will reserve 40 eraseblocks when attaching a 2977 partition. 2978 2979 default: 20 2980 2981 CONFIG_MTD_UBI_FASTMAP 2982 Fastmap is a mechanism which allows attaching an UBI device 2983 in nearly constant time. Instead of scanning the whole MTD device it 2984 only has to locate a checkpoint (called fastmap) on the device. 2985 The on-flash fastmap contains all information needed to attach 2986 the device. Using fastmap makes only sense on large devices where 2987 attaching by scanning takes long. UBI will not automatically install 2988 a fastmap on old images, but you can set the UBI parameter 2989 CONFIG_MTD_UBI_FASTMAP_AUTOCONVERT to 1 if you want so. Please note 2990 that fastmap-enabled images are still usable with UBI implementations 2991 without fastmap support. On typical flash devices the whole fastmap 2992 fits into one PEB. UBI will reserve PEBs to hold two fastmaps. 2993 2994 CONFIG_MTD_UBI_FASTMAP_AUTOCONVERT 2995 Set this parameter to enable fastmap automatically on images 2996 without a fastmap. 2997 default: 0 2998 2999 CONFIG_MTD_UBI_FM_DEBUG 3000 Enable UBI fastmap debug 3001 default: 0 3002 3003- UBIFS support 3004 CONFIG_CMD_UBIFS 3005 3006 Adds commands for interacting with UBI volumes formatted as 3007 UBIFS. UBIFS is read-only in u-boot. 3008 3009 Requires UBI support as well as CONFIG_LZO 3010 3011 CONFIG_UBIFS_SILENCE_MSG 3012 3013 Make the verbose messages from UBIFS stop printing. This leaves 3014 warnings and errors enabled. 3015 3016- SPL framework 3017 CONFIG_SPL 3018 Enable building of SPL globally. 3019 3020 CONFIG_SPL_LDSCRIPT 3021 LDSCRIPT for linking the SPL binary. 3022 3023 CONFIG_SPL_MAX_FOOTPRINT 3024 Maximum size in memory allocated to the SPL, BSS included. 3025 When defined, the linker checks that the actual memory 3026 used by SPL from _start to __bss_end does not exceed it. 3027 CONFIG_SPL_MAX_FOOTPRINT and CONFIG_SPL_BSS_MAX_SIZE 3028 must not be both defined at the same time. 3029 3030 CONFIG_SPL_MAX_SIZE 3031 Maximum size of the SPL image (text, data, rodata, and 3032 linker lists sections), BSS excluded. 3033 When defined, the linker checks that the actual size does 3034 not exceed it. 3035 3036 CONFIG_SPL_TEXT_BASE 3037 TEXT_BASE for linking the SPL binary. 3038 3039 CONFIG_SPL_RELOC_TEXT_BASE 3040 Address to relocate to. If unspecified, this is equal to 3041 CONFIG_SPL_TEXT_BASE (i.e. no relocation is done). 3042 3043 CONFIG_SPL_BSS_START_ADDR 3044 Link address for the BSS within the SPL binary. 3045 3046 CONFIG_SPL_BSS_MAX_SIZE 3047 Maximum size in memory allocated to the SPL BSS. 3048 When defined, the linker checks that the actual memory used 3049 by SPL from __bss_start to __bss_end does not exceed it. 3050 CONFIG_SPL_MAX_FOOTPRINT and CONFIG_SPL_BSS_MAX_SIZE 3051 must not be both defined at the same time. 3052 3053 CONFIG_SPL_STACK 3054 Adress of the start of the stack SPL will use 3055 3056 CONFIG_SPL_PANIC_ON_RAW_IMAGE 3057 When defined, SPL will panic() if the image it has 3058 loaded does not have a signature. 3059 Defining this is useful when code which loads images 3060 in SPL cannot guarantee that absolutely all read errors 3061 will be caught. 3062 An example is the LPC32XX MLC NAND driver, which will 3063 consider that a completely unreadable NAND block is bad, 3064 and thus should be skipped silently. 3065 3066 CONFIG_SPL_RELOC_STACK 3067 Adress of the start of the stack SPL will use after 3068 relocation. If unspecified, this is equal to 3069 CONFIG_SPL_STACK. 3070 3071 CONFIG_SYS_SPL_MALLOC_START 3072 Starting address of the malloc pool used in SPL. 3073 When this option is set the full malloc is used in SPL and 3074 it is set up by spl_init() and before that, the simple malloc() 3075 can be used if CONFIG_SYS_MALLOC_F is defined. 3076 3077 CONFIG_SYS_SPL_MALLOC_SIZE 3078 The size of the malloc pool used in SPL. 3079 3080 CONFIG_SPL_FRAMEWORK 3081 Enable the SPL framework under common/. This framework 3082 supports MMC, NAND and YMODEM loading of U-Boot and NAND 3083 NAND loading of the Linux Kernel. 3084 3085 CONFIG_SPL_OS_BOOT 3086 Enable booting directly to an OS from SPL. 3087 See also: doc/README.falcon 3088 3089 CONFIG_SPL_DISPLAY_PRINT 3090 For ARM, enable an optional function to print more information 3091 about the running system. 3092 3093 CONFIG_SPL_INIT_MINIMAL 3094 Arch init code should be built for a very small image 3095 3096 CONFIG_SYS_MMCSD_RAW_MODE_U_BOOT_PARTITION 3097 Partition on the MMC to load U-Boot from when the MMC is being 3098 used in raw mode 3099 3100 CONFIG_SYS_MMCSD_RAW_MODE_KERNEL_SECTOR 3101 Sector to load kernel uImage from when MMC is being 3102 used in raw mode (for Falcon mode) 3103 3104 CONFIG_SYS_MMCSD_RAW_MODE_ARGS_SECTOR, 3105 CONFIG_SYS_MMCSD_RAW_MODE_ARGS_SECTORS 3106 Sector and number of sectors to load kernel argument 3107 parameters from when MMC is being used in raw mode 3108 (for falcon mode) 3109 3110 CONFIG_SYS_MMCSD_FS_BOOT_PARTITION 3111 Partition on the MMC to load U-Boot from when the MMC is being 3112 used in fs mode 3113 3114 CONFIG_SPL_FS_LOAD_PAYLOAD_NAME 3115 Filename to read to load U-Boot when reading from filesystem 3116 3117 CONFIG_SPL_FS_LOAD_KERNEL_NAME 3118 Filename to read to load kernel uImage when reading 3119 from filesystem (for Falcon mode) 3120 3121 CONFIG_SPL_FS_LOAD_ARGS_NAME 3122 Filename to read to load kernel argument parameters 3123 when reading from filesystem (for Falcon mode) 3124 3125 CONFIG_SPL_MPC83XX_WAIT_FOR_NAND 3126 Set this for NAND SPL on PPC mpc83xx targets, so that 3127 start.S waits for the rest of the SPL to load before 3128 continuing (the hardware starts execution after just 3129 loading the first page rather than the full 4K). 3130 3131 CONFIG_SPL_SKIP_RELOCATE 3132 Avoid SPL relocation 3133 3134 CONFIG_SPL_NAND_BASE 3135 Include nand_base.c in the SPL. Requires 3136 CONFIG_SPL_NAND_DRIVERS. 3137 3138 CONFIG_SPL_NAND_DRIVERS 3139 SPL uses normal NAND drivers, not minimal drivers. 3140 3141 CONFIG_SPL_NAND_ECC 3142 Include standard software ECC in the SPL 3143 3144 CONFIG_SPL_NAND_SIMPLE 3145 Support for NAND boot using simple NAND drivers that 3146 expose the cmd_ctrl() interface. 3147 3148 CONFIG_SPL_UBI 3149 Support for a lightweight UBI (fastmap) scanner and 3150 loader 3151 3152 CONFIG_SPL_NAND_RAW_ONLY 3153 Support to boot only raw u-boot.bin images. Use this only 3154 if you need to save space. 3155 3156 CONFIG_SPL_COMMON_INIT_DDR 3157 Set for common ddr init with serial presence detect in 3158 SPL binary. 3159 3160 CONFIG_SYS_NAND_5_ADDR_CYCLE, CONFIG_SYS_NAND_PAGE_COUNT, 3161 CONFIG_SYS_NAND_PAGE_SIZE, CONFIG_SYS_NAND_OOBSIZE, 3162 CONFIG_SYS_NAND_BLOCK_SIZE, CONFIG_SYS_NAND_BAD_BLOCK_POS, 3163 CONFIG_SYS_NAND_ECCPOS, CONFIG_SYS_NAND_ECCSIZE, 3164 CONFIG_SYS_NAND_ECCBYTES 3165 Defines the size and behavior of the NAND that SPL uses 3166 to read U-Boot 3167 3168 CONFIG_SPL_NAND_BOOT 3169 Add support NAND boot 3170 3171 CONFIG_SYS_NAND_U_BOOT_OFFS 3172 Location in NAND to read U-Boot from 3173 3174 CONFIG_SYS_NAND_U_BOOT_DST 3175 Location in memory to load U-Boot to 3176 3177 CONFIG_SYS_NAND_U_BOOT_SIZE 3178 Size of image to load 3179 3180 CONFIG_SYS_NAND_U_BOOT_START 3181 Entry point in loaded image to jump to 3182 3183 CONFIG_SYS_NAND_HW_ECC_OOBFIRST 3184 Define this if you need to first read the OOB and then the 3185 data. This is used, for example, on davinci platforms. 3186 3187 CONFIG_SPL_OMAP3_ID_NAND 3188 Support for an OMAP3-specific set of functions to return the 3189 ID and MFR of the first attached NAND chip, if present. 3190 3191 CONFIG_SPL_RAM_DEVICE 3192 Support for running image already present in ram, in SPL binary 3193 3194 CONFIG_SPL_PAD_TO 3195 Image offset to which the SPL should be padded before appending 3196 the SPL payload. By default, this is defined as 3197 CONFIG_SPL_MAX_SIZE, or 0 if CONFIG_SPL_MAX_SIZE is undefined. 3198 CONFIG_SPL_PAD_TO must be either 0, meaning to append the SPL 3199 payload without any padding, or >= CONFIG_SPL_MAX_SIZE. 3200 3201 CONFIG_SPL_TARGET 3202 Final target image containing SPL and payload. Some SPLs 3203 use an arch-specific makefile fragment instead, for 3204 example if more than one image needs to be produced. 3205 3206 CONFIG_FIT_SPL_PRINT 3207 Printing information about a FIT image adds quite a bit of 3208 code to SPL. So this is normally disabled in SPL. Use this 3209 option to re-enable it. This will affect the output of the 3210 bootm command when booting a FIT image. 3211 3212- TPL framework 3213 CONFIG_TPL 3214 Enable building of TPL globally. 3215 3216 CONFIG_TPL_PAD_TO 3217 Image offset to which the TPL should be padded before appending 3218 the TPL payload. By default, this is defined as 3219 CONFIG_SPL_MAX_SIZE, or 0 if CONFIG_SPL_MAX_SIZE is undefined. 3220 CONFIG_SPL_PAD_TO must be either 0, meaning to append the SPL 3221 payload without any padding, or >= CONFIG_SPL_MAX_SIZE. 3222 3223- Interrupt support (PPC): 3224 3225 There are common interrupt_init() and timer_interrupt() 3226 for all PPC archs. interrupt_init() calls interrupt_init_cpu() 3227 for CPU specific initialization. interrupt_init_cpu() 3228 should set decrementer_count to appropriate value. If 3229 CPU resets decrementer automatically after interrupt 3230 (ppc4xx) it should set decrementer_count to zero. 3231 timer_interrupt() calls timer_interrupt_cpu() for CPU 3232 specific handling. If board has watchdog / status_led 3233 / other_activity_monitor it works automatically from 3234 general timer_interrupt(). 3235 3236 3237Board initialization settings: 3238------------------------------ 3239 3240During Initialization u-boot calls a number of board specific functions 3241to allow the preparation of board specific prerequisites, e.g. pin setup 3242before drivers are initialized. To enable these callbacks the 3243following configuration macros have to be defined. Currently this is 3244architecture specific, so please check arch/your_architecture/lib/board.c 3245typically in board_init_f() and board_init_r(). 3246 3247- CONFIG_BOARD_EARLY_INIT_F: Call board_early_init_f() 3248- CONFIG_BOARD_EARLY_INIT_R: Call board_early_init_r() 3249- CONFIG_BOARD_LATE_INIT: Call board_late_init() 3250- CONFIG_BOARD_POSTCLK_INIT: Call board_postclk_init() 3251 3252Configuration Settings: 3253----------------------- 3254 3255- CONFIG_SYS_SUPPORT_64BIT_DATA: Defined automatically if compiled as 64-bit. 3256 Optionally it can be defined to support 64-bit memory commands. 3257 3258- CONFIG_SYS_LONGHELP: Defined when you want long help messages included; 3259 undefine this when you're short of memory. 3260 3261- CONFIG_SYS_HELP_CMD_WIDTH: Defined when you want to override the default 3262 width of the commands listed in the 'help' command output. 3263 3264- CONFIG_SYS_PROMPT: This is what U-Boot prints on the console to 3265 prompt for user input. 3266 3267- CONFIG_SYS_CBSIZE: Buffer size for input from the Console 3268 3269- CONFIG_SYS_PBSIZE: Buffer size for Console output 3270 3271- CONFIG_SYS_MAXARGS: max. Number of arguments accepted for monitor commands 3272 3273- CONFIG_SYS_BARGSIZE: Buffer size for Boot Arguments which are passed to 3274 the application (usually a Linux kernel) when it is 3275 booted 3276 3277- CONFIG_SYS_BAUDRATE_TABLE: 3278 List of legal baudrate settings for this board. 3279 3280- CONFIG_SYS_MEMTEST_START, CONFIG_SYS_MEMTEST_END: 3281 Begin and End addresses of the area used by the 3282 simple memory test. 3283 3284- CONFIG_SYS_ALT_MEMTEST: 3285 Enable an alternate, more extensive memory test. 3286 3287- CONFIG_SYS_MEMTEST_SCRATCH: 3288 Scratch address used by the alternate memory test 3289 You only need to set this if address zero isn't writeable 3290 3291- CONFIG_SYS_MEM_RESERVE_SECURE 3292 Only implemented for ARMv8 for now. 3293 If defined, the size of CONFIG_SYS_MEM_RESERVE_SECURE memory 3294 is substracted from total RAM and won't be reported to OS. 3295 This memory can be used as secure memory. A variable 3296 gd->arch.secure_ram is used to track the location. In systems 3297 the RAM base is not zero, or RAM is divided into banks, 3298 this variable needs to be recalcuated to get the address. 3299 3300- CONFIG_SYS_MEM_TOP_HIDE: 3301 If CONFIG_SYS_MEM_TOP_HIDE is defined in the board config header, 3302 this specified memory area will get subtracted from the top 3303 (end) of RAM and won't get "touched" at all by U-Boot. By 3304 fixing up gd->ram_size the Linux kernel should gets passed 3305 the now "corrected" memory size and won't touch it either. 3306 This should work for arch/ppc and arch/powerpc. Only Linux 3307 board ports in arch/powerpc with bootwrapper support that 3308 recalculate the memory size from the SDRAM controller setup 3309 will have to get fixed in Linux additionally. 3310 3311 This option can be used as a workaround for the 440EPx/GRx 3312 CHIP 11 errata where the last 256 bytes in SDRAM shouldn't 3313 be touched. 3314 3315 WARNING: Please make sure that this value is a multiple of 3316 the Linux page size (normally 4k). If this is not the case, 3317 then the end address of the Linux memory will be located at a 3318 non page size aligned address and this could cause major 3319 problems. 3320 3321- CONFIG_SYS_LOADS_BAUD_CHANGE: 3322 Enable temporary baudrate change while serial download 3323 3324- CONFIG_SYS_SDRAM_BASE: 3325 Physical start address of SDRAM. _Must_ be 0 here. 3326 3327- CONFIG_SYS_FLASH_BASE: 3328 Physical start address of Flash memory. 3329 3330- CONFIG_SYS_MONITOR_BASE: 3331 Physical start address of boot monitor code (set by 3332 make config files to be same as the text base address 3333 (CONFIG_SYS_TEXT_BASE) used when linking) - same as 3334 CONFIG_SYS_FLASH_BASE when booting from flash. 3335 3336- CONFIG_SYS_MONITOR_LEN: 3337 Size of memory reserved for monitor code, used to 3338 determine _at_compile_time_ (!) if the environment is 3339 embedded within the U-Boot image, or in a separate 3340 flash sector. 3341 3342- CONFIG_SYS_MALLOC_LEN: 3343 Size of DRAM reserved for malloc() use. 3344 3345- CONFIG_SYS_MALLOC_F_LEN 3346 Size of the malloc() pool for use before relocation. If 3347 this is defined, then a very simple malloc() implementation 3348 will become available before relocation. The address is just 3349 below the global data, and the stack is moved down to make 3350 space. 3351 3352 This feature allocates regions with increasing addresses 3353 within the region. calloc() is supported, but realloc() 3354 is not available. free() is supported but does nothing. 3355 The memory will be freed (or in fact just forgotten) when 3356 U-Boot relocates itself. 3357 3358- CONFIG_SYS_MALLOC_SIMPLE 3359 Provides a simple and small malloc() and calloc() for those 3360 boards which do not use the full malloc in SPL (which is 3361 enabled with CONFIG_SYS_SPL_MALLOC_START). 3362 3363- CONFIG_SYS_NONCACHED_MEMORY: 3364 Size of non-cached memory area. This area of memory will be 3365 typically located right below the malloc() area and mapped 3366 uncached in the MMU. This is useful for drivers that would 3367 otherwise require a lot of explicit cache maintenance. For 3368 some drivers it's also impossible to properly maintain the 3369 cache. For example if the regions that need to be flushed 3370 are not a multiple of the cache-line size, *and* padding 3371 cannot be allocated between the regions to align them (i.e. 3372 if the HW requires a contiguous array of regions, and the 3373 size of each region is not cache-aligned), then a flush of 3374 one region may result in overwriting data that hardware has 3375 written to another region in the same cache-line. This can 3376 happen for example in network drivers where descriptors for 3377 buffers are typically smaller than the CPU cache-line (e.g. 3378 16 bytes vs. 32 or 64 bytes). 3379 3380 Non-cached memory is only supported on 32-bit ARM at present. 3381 3382- CONFIG_SYS_BOOTM_LEN: 3383 Normally compressed uImages are limited to an 3384 uncompressed size of 8 MBytes. If this is not enough, 3385 you can define CONFIG_SYS_BOOTM_LEN in your board config file 3386 to adjust this setting to your needs. 3387 3388- CONFIG_SYS_BOOTMAPSZ: 3389 Maximum size of memory mapped by the startup code of 3390 the Linux kernel; all data that must be processed by 3391 the Linux kernel (bd_info, boot arguments, FDT blob if 3392 used) must be put below this limit, unless "bootm_low" 3393 environment variable is defined and non-zero. In such case 3394 all data for the Linux kernel must be between "bootm_low" 3395 and "bootm_low" + CONFIG_SYS_BOOTMAPSZ. The environment 3396 variable "bootm_mapsize" will override the value of 3397 CONFIG_SYS_BOOTMAPSZ. If CONFIG_SYS_BOOTMAPSZ is undefined, 3398 then the value in "bootm_size" will be used instead. 3399 3400- CONFIG_SYS_BOOT_RAMDISK_HIGH: 3401 Enable initrd_high functionality. If defined then the 3402 initrd_high feature is enabled and the bootm ramdisk subcommand 3403 is enabled. 3404 3405- CONFIG_SYS_BOOT_GET_CMDLINE: 3406 Enables allocating and saving kernel cmdline in space between 3407 "bootm_low" and "bootm_low" + BOOTMAPSZ. 3408 3409- CONFIG_SYS_BOOT_GET_KBD: 3410 Enables allocating and saving a kernel copy of the bd_info in 3411 space between "bootm_low" and "bootm_low" + BOOTMAPSZ. 3412 3413- CONFIG_SYS_MAX_FLASH_BANKS: 3414 Max number of Flash memory banks 3415 3416- CONFIG_SYS_MAX_FLASH_SECT: 3417 Max number of sectors on a Flash chip 3418 3419- CONFIG_SYS_FLASH_ERASE_TOUT: 3420 Timeout for Flash erase operations (in ms) 3421 3422- CONFIG_SYS_FLASH_WRITE_TOUT: 3423 Timeout for Flash write operations (in ms) 3424 3425- CONFIG_SYS_FLASH_LOCK_TOUT 3426 Timeout for Flash set sector lock bit operation (in ms) 3427 3428- CONFIG_SYS_FLASH_UNLOCK_TOUT 3429 Timeout for Flash clear lock bits operation (in ms) 3430 3431- CONFIG_SYS_FLASH_PROTECTION 3432 If defined, hardware flash sectors protection is used 3433 instead of U-Boot software protection. 3434 3435- CONFIG_SYS_DIRECT_FLASH_TFTP: 3436 3437 Enable TFTP transfers directly to flash memory; 3438 without this option such a download has to be 3439 performed in two steps: (1) download to RAM, and (2) 3440 copy from RAM to flash. 3441 3442 The two-step approach is usually more reliable, since 3443 you can check if the download worked before you erase 3444 the flash, but in some situations (when system RAM is 3445 too limited to allow for a temporary copy of the 3446 downloaded image) this option may be very useful. 3447 3448- CONFIG_SYS_FLASH_CFI: 3449 Define if the flash driver uses extra elements in the 3450 common flash structure for storing flash geometry. 3451 3452- CONFIG_FLASH_CFI_DRIVER 3453 This option also enables the building of the cfi_flash driver 3454 in the drivers directory 3455 3456- CONFIG_FLASH_CFI_MTD 3457 This option enables the building of the cfi_mtd driver 3458 in the drivers directory. The driver exports CFI flash 3459 to the MTD layer. 3460 3461- CONFIG_SYS_FLASH_USE_BUFFER_WRITE 3462 Use buffered writes to flash. 3463 3464- CONFIG_FLASH_SPANSION_S29WS_N 3465 s29ws-n MirrorBit flash has non-standard addresses for buffered 3466 write commands. 3467 3468- CONFIG_SYS_FLASH_QUIET_TEST 3469 If this option is defined, the common CFI flash doesn't 3470 print it's warning upon not recognized FLASH banks. This 3471 is useful, if some of the configured banks are only 3472 optionally available. 3473 3474- CONFIG_FLASH_SHOW_PROGRESS 3475 If defined (must be an integer), print out countdown 3476 digits and dots. Recommended value: 45 (9..1) for 80 3477 column displays, 15 (3..1) for 40 column displays. 3478 3479- CONFIG_FLASH_VERIFY 3480 If defined, the content of the flash (destination) is compared 3481 against the source after the write operation. An error message 3482 will be printed when the contents are not identical. 3483 Please note that this option is useless in nearly all cases, 3484 since such flash programming errors usually are detected earlier 3485 while unprotecting/erasing/programming. Please only enable 3486 this option if you really know what you are doing. 3487 3488- CONFIG_SYS_RX_ETH_BUFFER: 3489 Defines the number of Ethernet receive buffers. On some 3490 Ethernet controllers it is recommended to set this value 3491 to 8 or even higher (EEPRO100 or 405 EMAC), since all 3492 buffers can be full shortly after enabling the interface 3493 on high Ethernet traffic. 3494 Defaults to 4 if not defined. 3495 3496- CONFIG_ENV_MAX_ENTRIES 3497 3498 Maximum number of entries in the hash table that is used 3499 internally to store the environment settings. The default 3500 setting is supposed to be generous and should work in most 3501 cases. This setting can be used to tune behaviour; see 3502 lib/hashtable.c for details. 3503 3504- CONFIG_ENV_FLAGS_LIST_DEFAULT 3505- CONFIG_ENV_FLAGS_LIST_STATIC 3506 Enable validation of the values given to environment variables when 3507 calling env set. Variables can be restricted to only decimal, 3508 hexadecimal, or boolean. If CONFIG_CMD_NET is also defined, 3509 the variables can also be restricted to IP address or MAC address. 3510 3511 The format of the list is: 3512 type_attribute = [s|d|x|b|i|m] 3513 access_attribute = [a|r|o|c] 3514 attributes = type_attribute[access_attribute] 3515 entry = variable_name[:attributes] 3516 list = entry[,list] 3517 3518 The type attributes are: 3519 s - String (default) 3520 d - Decimal 3521 x - Hexadecimal 3522 b - Boolean ([1yYtT|0nNfF]) 3523 i - IP address 3524 m - MAC address 3525 3526 The access attributes are: 3527 a - Any (default) 3528 r - Read-only 3529 o - Write-once 3530 c - Change-default 3531 3532 - CONFIG_ENV_FLAGS_LIST_DEFAULT 3533 Define this to a list (string) to define the ".flags" 3534 environment variable in the default or embedded environment. 3535 3536 - CONFIG_ENV_FLAGS_LIST_STATIC 3537 Define this to a list (string) to define validation that 3538 should be done if an entry is not found in the ".flags" 3539 environment variable. To override a setting in the static 3540 list, simply add an entry for the same variable name to the 3541 ".flags" variable. 3542 3543 If CONFIG_REGEX is defined, the variable_name above is evaluated as a 3544 regular expression. This allows multiple variables to define the same 3545 flags without explicitly listing them for each variable. 3546 3547- CONFIG_ENV_ACCESS_IGNORE_FORCE 3548 If defined, don't allow the -f switch to env set override variable 3549 access flags. 3550 3551- CONFIG_USE_STDINT 3552 If stdint.h is available with your toolchain you can define this 3553 option to enable it. You can provide option 'USE_STDINT=1' when 3554 building U-Boot to enable this. 3555 3556The following definitions that deal with the placement and management 3557of environment data (variable area); in general, we support the 3558following configurations: 3559 3560- CONFIG_BUILD_ENVCRC: 3561 3562 Builds up envcrc with the target environment so that external utils 3563 may easily extract it and embed it in final U-Boot images. 3564 3565- CONFIG_ENV_IS_IN_FLASH: 3566 3567 Define this if the environment is in flash memory. 3568 3569 a) The environment occupies one whole flash sector, which is 3570 "embedded" in the text segment with the U-Boot code. This 3571 happens usually with "bottom boot sector" or "top boot 3572 sector" type flash chips, which have several smaller 3573 sectors at the start or the end. For instance, such a 3574 layout can have sector sizes of 8, 2x4, 16, Nx32 kB. In 3575 such a case you would place the environment in one of the 3576 4 kB sectors - with U-Boot code before and after it. With 3577 "top boot sector" type flash chips, you would put the 3578 environment in one of the last sectors, leaving a gap 3579 between U-Boot and the environment. 3580 3581 - CONFIG_ENV_OFFSET: 3582 3583 Offset of environment data (variable area) to the 3584 beginning of flash memory; for instance, with bottom boot 3585 type flash chips the second sector can be used: the offset 3586 for this sector is given here. 3587 3588 CONFIG_ENV_OFFSET is used relative to CONFIG_SYS_FLASH_BASE. 3589 3590 - CONFIG_ENV_ADDR: 3591 3592 This is just another way to specify the start address of 3593 the flash sector containing the environment (instead of 3594 CONFIG_ENV_OFFSET). 3595 3596 - CONFIG_ENV_SECT_SIZE: 3597 3598 Size of the sector containing the environment. 3599 3600 3601 b) Sometimes flash chips have few, equal sized, BIG sectors. 3602 In such a case you don't want to spend a whole sector for 3603 the environment. 3604 3605 - CONFIG_ENV_SIZE: 3606 3607 If you use this in combination with CONFIG_ENV_IS_IN_FLASH 3608 and CONFIG_ENV_SECT_SIZE, you can specify to use only a part 3609 of this flash sector for the environment. This saves 3610 memory for the RAM copy of the environment. 3611 3612 It may also save flash memory if you decide to use this 3613 when your environment is "embedded" within U-Boot code, 3614 since then the remainder of the flash sector could be used 3615 for U-Boot code. It should be pointed out that this is 3616 STRONGLY DISCOURAGED from a robustness point of view: 3617 updating the environment in flash makes it always 3618 necessary to erase the WHOLE sector. If something goes 3619 wrong before the contents has been restored from a copy in 3620 RAM, your target system will be dead. 3621 3622 - CONFIG_ENV_ADDR_REDUND 3623 CONFIG_ENV_SIZE_REDUND 3624 3625 These settings describe a second storage area used to hold 3626 a redundant copy of the environment data, so that there is 3627 a valid backup copy in case there is a power failure during 3628 a "saveenv" operation. 3629 3630BE CAREFUL! Any changes to the flash layout, and some changes to the 3631source code will make it necessary to adapt <board>/u-boot.lds* 3632accordingly! 3633 3634 3635- CONFIG_ENV_IS_IN_NVRAM: 3636 3637 Define this if you have some non-volatile memory device 3638 (NVRAM, battery buffered SRAM) which you want to use for the 3639 environment. 3640 3641 - CONFIG_ENV_ADDR: 3642 - CONFIG_ENV_SIZE: 3643 3644 These two #defines are used to determine the memory area you 3645 want to use for environment. It is assumed that this memory 3646 can just be read and written to, without any special 3647 provision. 3648 3649BE CAREFUL! The first access to the environment happens quite early 3650in U-Boot initialization (when we try to get the setting of for the 3651console baudrate). You *MUST* have mapped your NVRAM area then, or 3652U-Boot will hang. 3653 3654Please note that even with NVRAM we still use a copy of the 3655environment in RAM: we could work on NVRAM directly, but we want to 3656keep settings there always unmodified except somebody uses "saveenv" 3657to save the current settings. 3658 3659 3660- CONFIG_ENV_IS_IN_EEPROM: 3661 3662 Use this if you have an EEPROM or similar serial access 3663 device and a driver for it. 3664 3665 - CONFIG_ENV_OFFSET: 3666 - CONFIG_ENV_SIZE: 3667 3668 These two #defines specify the offset and size of the 3669 environment area within the total memory of your EEPROM. 3670 3671 - CONFIG_SYS_I2C_EEPROM_ADDR: 3672 If defined, specified the chip address of the EEPROM device. 3673 The default address is zero. 3674 3675 - CONFIG_SYS_I2C_EEPROM_BUS: 3676 If defined, specified the i2c bus of the EEPROM device. 3677 3678 - CONFIG_SYS_EEPROM_PAGE_WRITE_BITS: 3679 If defined, the number of bits used to address bytes in a 3680 single page in the EEPROM device. A 64 byte page, for example 3681 would require six bits. 3682 3683 - CONFIG_SYS_EEPROM_PAGE_WRITE_DELAY_MS: 3684 If defined, the number of milliseconds to delay between 3685 page writes. The default is zero milliseconds. 3686 3687 - CONFIG_SYS_I2C_EEPROM_ADDR_LEN: 3688 The length in bytes of the EEPROM memory array address. Note 3689 that this is NOT the chip address length! 3690 3691 - CONFIG_SYS_I2C_EEPROM_ADDR_OVERFLOW: 3692 EEPROM chips that implement "address overflow" are ones 3693 like Catalyst 24WC04/08/16 which has 9/10/11 bits of 3694 address and the extra bits end up in the "chip address" bit 3695 slots. This makes a 24WC08 (1Kbyte) chip look like four 256 3696 byte chips. 3697 3698 Note that we consider the length of the address field to 3699 still be one byte because the extra address bits are hidden 3700 in the chip address. 3701 3702 - CONFIG_SYS_EEPROM_SIZE: 3703 The size in bytes of the EEPROM device. 3704 3705 - CONFIG_ENV_EEPROM_IS_ON_I2C 3706 define this, if you have I2C and SPI activated, and your 3707 EEPROM, which holds the environment, is on the I2C bus. 3708 3709 - CONFIG_I2C_ENV_EEPROM_BUS 3710 if you have an Environment on an EEPROM reached over 3711 I2C muxes, you can define here, how to reach this 3712 EEPROM. For example: 3713 3714 #define CONFIG_I2C_ENV_EEPROM_BUS 1 3715 3716 EEPROM which holds the environment, is reached over 3717 a pca9547 i2c mux with address 0x70, channel 3. 3718 3719- CONFIG_ENV_IS_IN_DATAFLASH: 3720 3721 Define this if you have a DataFlash memory device which you 3722 want to use for the environment. 3723 3724 - CONFIG_ENV_OFFSET: 3725 - CONFIG_ENV_ADDR: 3726 - CONFIG_ENV_SIZE: 3727 3728 These three #defines specify the offset and size of the 3729 environment area within the total memory of your DataFlash placed 3730 at the specified address. 3731 3732- CONFIG_ENV_IS_IN_SPI_FLASH: 3733 3734 Define this if you have a SPI Flash memory device which you 3735 want to use for the environment. 3736 3737 - CONFIG_ENV_OFFSET: 3738 - CONFIG_ENV_SIZE: 3739 3740 These two #defines specify the offset and size of the 3741 environment area within the SPI Flash. CONFIG_ENV_OFFSET must be 3742 aligned to an erase sector boundary. 3743 3744 - CONFIG_ENV_SECT_SIZE: 3745 3746 Define the SPI flash's sector size. 3747 3748 - CONFIG_ENV_OFFSET_REDUND (optional): 3749 3750 This setting describes a second storage area of CONFIG_ENV_SIZE 3751 size used to hold a redundant copy of the environment data, so 3752 that there is a valid backup copy in case there is a power failure 3753 during a "saveenv" operation. CONFIG_ENV_OFFSET_REDUND must be 3754 aligned to an erase sector boundary. 3755 3756 - CONFIG_ENV_SPI_BUS (optional): 3757 - CONFIG_ENV_SPI_CS (optional): 3758 3759 Define the SPI bus and chip select. If not defined they will be 0. 3760 3761 - CONFIG_ENV_SPI_MAX_HZ (optional): 3762 3763 Define the SPI max work clock. If not defined then use 1MHz. 3764 3765 - CONFIG_ENV_SPI_MODE (optional): 3766 3767 Define the SPI work mode. If not defined then use SPI_MODE_3. 3768 3769- CONFIG_ENV_IS_IN_REMOTE: 3770 3771 Define this if you have a remote memory space which you 3772 want to use for the local device's environment. 3773 3774 - CONFIG_ENV_ADDR: 3775 - CONFIG_ENV_SIZE: 3776 3777 These two #defines specify the address and size of the 3778 environment area within the remote memory space. The 3779 local device can get the environment from remote memory 3780 space by SRIO or PCIE links. 3781 3782BE CAREFUL! For some special cases, the local device can not use 3783"saveenv" command. For example, the local device will get the 3784environment stored in a remote NOR flash by SRIO or PCIE link, 3785but it can not erase, write this NOR flash by SRIO or PCIE interface. 3786 3787- CONFIG_ENV_IS_IN_NAND: 3788 3789 Define this if you have a NAND device which you want to use 3790 for the environment. 3791 3792 - CONFIG_ENV_OFFSET: 3793 - CONFIG_ENV_SIZE: 3794 3795 These two #defines specify the offset and size of the environment 3796 area within the first NAND device. CONFIG_ENV_OFFSET must be 3797 aligned to an erase block boundary. 3798 3799 - CONFIG_ENV_OFFSET_REDUND (optional): 3800 3801 This setting describes a second storage area of CONFIG_ENV_SIZE 3802 size used to hold a redundant copy of the environment data, so 3803 that there is a valid backup copy in case there is a power failure 3804 during a "saveenv" operation. CONFIG_ENV_OFFSET_REDUND must be 3805 aligned to an erase block boundary. 3806 3807 - CONFIG_ENV_RANGE (optional): 3808 3809 Specifies the length of the region in which the environment 3810 can be written. This should be a multiple of the NAND device's 3811 block size. Specifying a range with more erase blocks than 3812 are needed to hold CONFIG_ENV_SIZE allows bad blocks within 3813 the range to be avoided. 3814 3815 - CONFIG_ENV_OFFSET_OOB (optional): 3816 3817 Enables support for dynamically retrieving the offset of the 3818 environment from block zero's out-of-band data. The 3819 "nand env.oob" command can be used to record this offset. 3820 Currently, CONFIG_ENV_OFFSET_REDUND is not supported when 3821 using CONFIG_ENV_OFFSET_OOB. 3822 3823- CONFIG_NAND_ENV_DST 3824 3825 Defines address in RAM to which the nand_spl code should copy the 3826 environment. If redundant environment is used, it will be copied to 3827 CONFIG_NAND_ENV_DST + CONFIG_ENV_SIZE. 3828 3829- CONFIG_ENV_IS_IN_UBI: 3830 3831 Define this if you have an UBI volume that you want to use for the 3832 environment. This has the benefit of wear-leveling the environment 3833 accesses, which is important on NAND. 3834 3835 - CONFIG_ENV_UBI_PART: 3836 3837 Define this to a string that is the mtd partition containing the UBI. 3838 3839 - CONFIG_ENV_UBI_VOLUME: 3840 3841 Define this to the name of the volume that you want to store the 3842 environment in. 3843 3844 - CONFIG_ENV_UBI_VOLUME_REDUND: 3845 3846 Define this to the name of another volume to store a second copy of 3847 the environment in. This will enable redundant environments in UBI. 3848 It is assumed that both volumes are in the same MTD partition. 3849 3850 - CONFIG_UBI_SILENCE_MSG 3851 - CONFIG_UBIFS_SILENCE_MSG 3852 3853 You will probably want to define these to avoid a really noisy system 3854 when storing the env in UBI. 3855 3856- CONFIG_ENV_IS_IN_FAT: 3857 Define this if you want to use the FAT file system for the environment. 3858 3859 - FAT_ENV_INTERFACE: 3860 3861 Define this to a string that is the name of the block device. 3862 3863 - FAT_ENV_DEVICE_AND_PART: 3864 3865 Define this to a string to specify the partition of the device. It can 3866 be as following: 3867 3868 "D:P", "D:0", "D", "D:" or "D:auto" (D, P are integers. And P >= 1) 3869 - "D:P": device D partition P. Error occurs if device D has no 3870 partition table. 3871 - "D:0": device D. 3872 - "D" or "D:": device D partition 1 if device D has partition 3873 table, or the whole device D if has no partition 3874 table. 3875 - "D:auto": first partition in device D with bootable flag set. 3876 If none, first valid partition in device D. If no 3877 partition table then means device D. 3878 3879 - FAT_ENV_FILE: 3880 3881 It's a string of the FAT file name. This file use to store the 3882 environment. 3883 3884 - CONFIG_FAT_WRITE: 3885 This should be defined. Otherwise it cannot save the environment file. 3886 3887- CONFIG_ENV_IS_IN_MMC: 3888 3889 Define this if you have an MMC device which you want to use for the 3890 environment. 3891 3892 - CONFIG_SYS_MMC_ENV_DEV: 3893 3894 Specifies which MMC device the environment is stored in. 3895 3896 - CONFIG_SYS_MMC_ENV_PART (optional): 3897 3898 Specifies which MMC partition the environment is stored in. If not 3899 set, defaults to partition 0, the user area. Common values might be 3900 1 (first MMC boot partition), 2 (second MMC boot partition). 3901 3902 - CONFIG_ENV_OFFSET: 3903 - CONFIG_ENV_SIZE: 3904 3905 These two #defines specify the offset and size of the environment 3906 area within the specified MMC device. 3907 3908 If offset is positive (the usual case), it is treated as relative to 3909 the start of the MMC partition. If offset is negative, it is treated 3910 as relative to the end of the MMC partition. This can be useful if 3911 your board may be fitted with different MMC devices, which have 3912 different sizes for the MMC partitions, and you always want the 3913 environment placed at the very end of the partition, to leave the 3914 maximum possible space before it, to store other data. 3915 3916 These two values are in units of bytes, but must be aligned to an 3917 MMC sector boundary. 3918 3919 - CONFIG_ENV_OFFSET_REDUND (optional): 3920 3921 Specifies a second storage area, of CONFIG_ENV_SIZE size, used to 3922 hold a redundant copy of the environment data. This provides a 3923 valid backup copy in case the other copy is corrupted, e.g. due 3924 to a power failure during a "saveenv" operation. 3925 3926 This value may also be positive or negative; this is handled in the 3927 same way as CONFIG_ENV_OFFSET. 3928 3929 This value is also in units of bytes, but must also be aligned to 3930 an MMC sector boundary. 3931 3932 - CONFIG_ENV_SIZE_REDUND (optional): 3933 3934 This value need not be set, even when CONFIG_ENV_OFFSET_REDUND is 3935 set. If this value is set, it must be set to the same value as 3936 CONFIG_ENV_SIZE. 3937 3938- CONFIG_SYS_SPI_INIT_OFFSET 3939 3940 Defines offset to the initial SPI buffer area in DPRAM. The 3941 area is used at an early stage (ROM part) if the environment 3942 is configured to reside in the SPI EEPROM: We need a 520 byte 3943 scratch DPRAM area. It is used between the two initialization 3944 calls (spi_init_f() and spi_init_r()). A value of 0xB00 seems 3945 to be a good choice since it makes it far enough from the 3946 start of the data area as well as from the stack pointer. 3947 3948Please note that the environment is read-only until the monitor 3949has been relocated to RAM and a RAM copy of the environment has been 3950created; also, when using EEPROM you will have to use getenv_f() 3951until then to read environment variables. 3952 3953The environment is protected by a CRC32 checksum. Before the monitor 3954is relocated into RAM, as a result of a bad CRC you will be working 3955with the compiled-in default environment - *silently*!!! [This is 3956necessary, because the first environment variable we need is the 3957"baudrate" setting for the console - if we have a bad CRC, we don't 3958have any device yet where we could complain.] 3959 3960Note: once the monitor has been relocated, then it will complain if 3961the default environment is used; a new CRC is computed as soon as you 3962use the "saveenv" command to store a valid environment. 3963 3964- CONFIG_SYS_FAULT_ECHO_LINK_DOWN: 3965 Echo the inverted Ethernet link state to the fault LED. 3966 3967 Note: If this option is active, then CONFIG_SYS_FAULT_MII_ADDR 3968 also needs to be defined. 3969 3970- CONFIG_SYS_FAULT_MII_ADDR: 3971 MII address of the PHY to check for the Ethernet link state. 3972 3973- CONFIG_NS16550_MIN_FUNCTIONS: 3974 Define this if you desire to only have use of the NS16550_init 3975 and NS16550_putc functions for the serial driver located at 3976 drivers/serial/ns16550.c. This option is useful for saving 3977 space for already greatly restricted images, including but not 3978 limited to NAND_SPL configurations. 3979 3980- CONFIG_DISPLAY_BOARDINFO 3981 Display information about the board that U-Boot is running on 3982 when U-Boot starts up. The board function checkboard() is called 3983 to do this. 3984 3985- CONFIG_DISPLAY_BOARDINFO_LATE 3986 Similar to the previous option, but display this information 3987 later, once stdio is running and output goes to the LCD, if 3988 present. 3989 3990- CONFIG_BOARD_SIZE_LIMIT: 3991 Maximum size of the U-Boot image. When defined, the 3992 build system checks that the actual size does not 3993 exceed it. 3994 3995Low Level (hardware related) configuration options: 3996--------------------------------------------------- 3997 3998- CONFIG_SYS_CACHELINE_SIZE: 3999 Cache Line Size of the CPU. 4000 4001- CONFIG_SYS_DEFAULT_IMMR: 4002 Default address of the IMMR after system reset. 4003 4004 Needed on some 8260 systems (MPC8260ADS, PQ2FADS-ZU, 4005 and RPXsuper) to be able to adjust the position of 4006 the IMMR register after a reset. 4007 4008- CONFIG_SYS_CCSRBAR_DEFAULT: 4009 Default (power-on reset) physical address of CCSR on Freescale 4010 PowerPC SOCs. 4011 4012- CONFIG_SYS_CCSRBAR: 4013 Virtual address of CCSR. On a 32-bit build, this is typically 4014 the same value as CONFIG_SYS_CCSRBAR_DEFAULT. 4015 4016 CONFIG_SYS_DEFAULT_IMMR must also be set to this value, 4017 for cross-platform code that uses that macro instead. 4018 4019- CONFIG_SYS_CCSRBAR_PHYS: 4020 Physical address of CCSR. CCSR can be relocated to a new 4021 physical address, if desired. In this case, this macro should 4022 be set to that address. Otherwise, it should be set to the 4023 same value as CONFIG_SYS_CCSRBAR_DEFAULT. For example, CCSR 4024 is typically relocated on 36-bit builds. It is recommended 4025 that this macro be defined via the _HIGH and _LOW macros: 4026 4027 #define CONFIG_SYS_CCSRBAR_PHYS ((CONFIG_SYS_CCSRBAR_PHYS_HIGH 4028 * 1ull) << 32 | CONFIG_SYS_CCSRBAR_PHYS_LOW) 4029 4030- CONFIG_SYS_CCSRBAR_PHYS_HIGH: 4031 Bits 33-36 of CONFIG_SYS_CCSRBAR_PHYS. This value is typically 4032 either 0 (32-bit build) or 0xF (36-bit build). This macro is 4033 used in assembly code, so it must not contain typecasts or 4034 integer size suffixes (e.g. "ULL"). 4035 4036- CONFIG_SYS_CCSRBAR_PHYS_LOW: 4037 Lower 32-bits of CONFIG_SYS_CCSRBAR_PHYS. This macro is 4038 used in assembly code, so it must not contain typecasts or 4039 integer size suffixes (e.g. "ULL"). 4040 4041- CONFIG_SYS_CCSR_DO_NOT_RELOCATE: 4042 If this macro is defined, then CONFIG_SYS_CCSRBAR_PHYS will be 4043 forced to a value that ensures that CCSR is not relocated. 4044 4045- Floppy Disk Support: 4046 CONFIG_SYS_FDC_DRIVE_NUMBER 4047 4048 the default drive number (default value 0) 4049 4050 CONFIG_SYS_ISA_IO_STRIDE 4051 4052 defines the spacing between FDC chipset registers 4053 (default value 1) 4054 4055 CONFIG_SYS_ISA_IO_OFFSET 4056 4057 defines the offset of register from address. It 4058 depends on which part of the data bus is connected to 4059 the FDC chipset. (default value 0) 4060 4061 If CONFIG_SYS_ISA_IO_STRIDE CONFIG_SYS_ISA_IO_OFFSET and 4062 CONFIG_SYS_FDC_DRIVE_NUMBER are undefined, they take their 4063 default value. 4064 4065 if CONFIG_SYS_FDC_HW_INIT is defined, then the function 4066 fdc_hw_init() is called at the beginning of the FDC 4067 setup. fdc_hw_init() must be provided by the board 4068 source code. It is used to make hardware-dependent 4069 initializations. 4070 4071- CONFIG_IDE_AHB: 4072 Most IDE controllers were designed to be connected with PCI 4073 interface. Only few of them were designed for AHB interface. 4074 When software is doing ATA command and data transfer to 4075 IDE devices through IDE-AHB controller, some additional 4076 registers accessing to these kind of IDE-AHB controller 4077 is required. 4078 4079- CONFIG_SYS_IMMR: Physical address of the Internal Memory. 4080 DO NOT CHANGE unless you know exactly what you're 4081 doing! (11-4) [MPC8xx/82xx systems only] 4082 4083- CONFIG_SYS_INIT_RAM_ADDR: 4084 4085 Start address of memory area that can be used for 4086 initial data and stack; please note that this must be 4087 writable memory that is working WITHOUT special 4088 initialization, i. e. you CANNOT use normal RAM which 4089 will become available only after programming the 4090 memory controller and running certain initialization 4091 sequences. 4092 4093 U-Boot uses the following memory types: 4094 - MPC8xx and MPC8260: IMMR (internal memory of the CPU) 4095 - MPC824X: data cache 4096 - PPC4xx: data cache 4097 4098- CONFIG_SYS_GBL_DATA_OFFSET: 4099 4100 Offset of the initial data structure in the memory 4101 area defined by CONFIG_SYS_INIT_RAM_ADDR. Usually 4102 CONFIG_SYS_GBL_DATA_OFFSET is chosen such that the initial 4103 data is located at the end of the available space 4104 (sometimes written as (CONFIG_SYS_INIT_RAM_SIZE - 4105 GENERATED_GBL_DATA_SIZE), and the initial stack is just 4106 below that area (growing from (CONFIG_SYS_INIT_RAM_ADDR + 4107 CONFIG_SYS_GBL_DATA_OFFSET) downward. 4108 4109 Note: 4110 On the MPC824X (or other systems that use the data 4111 cache for initial memory) the address chosen for 4112 CONFIG_SYS_INIT_RAM_ADDR is basically arbitrary - it must 4113 point to an otherwise UNUSED address space between 4114 the top of RAM and the start of the PCI space. 4115 4116- CONFIG_SYS_SIUMCR: SIU Module Configuration (11-6) 4117 4118- CONFIG_SYS_SYPCR: System Protection Control (11-9) 4119 4120- CONFIG_SYS_TBSCR: Time Base Status and Control (11-26) 4121 4122- CONFIG_SYS_PISCR: Periodic Interrupt Status and Control (11-31) 4123 4124- CONFIG_SYS_PLPRCR: PLL, Low-Power, and Reset Control Register (15-30) 4125 4126- CONFIG_SYS_SCCR: System Clock and reset Control Register (15-27) 4127 4128- CONFIG_SYS_OR_TIMING_SDRAM: 4129 SDRAM timing 4130 4131- CONFIG_SYS_MAMR_PTA: 4132 periodic timer for refresh 4133 4134- CONFIG_SYS_DER: Debug Event Register (37-47) 4135 4136- FLASH_BASE0_PRELIM, FLASH_BASE1_PRELIM, CONFIG_SYS_REMAP_OR_AM, 4137 CONFIG_SYS_PRELIM_OR_AM, CONFIG_SYS_OR_TIMING_FLASH, CONFIG_SYS_OR0_REMAP, 4138 CONFIG_SYS_OR0_PRELIM, CONFIG_SYS_BR0_PRELIM, CONFIG_SYS_OR1_REMAP, CONFIG_SYS_OR1_PRELIM, 4139 CONFIG_SYS_BR1_PRELIM: 4140 Memory Controller Definitions: BR0/1 and OR0/1 (FLASH) 4141 4142- SDRAM_BASE2_PRELIM, SDRAM_BASE3_PRELIM, SDRAM_MAX_SIZE, 4143 CONFIG_SYS_OR_TIMING_SDRAM, CONFIG_SYS_OR2_PRELIM, CONFIG_SYS_BR2_PRELIM, 4144 CONFIG_SYS_OR3_PRELIM, CONFIG_SYS_BR3_PRELIM: 4145 Memory Controller Definitions: BR2/3 and OR2/3 (SDRAM) 4146 4147- CONFIG_SYS_MAMR_PTA, CONFIG_SYS_MPTPR_2BK_4K, CONFIG_SYS_MPTPR_1BK_4K, CONFIG_SYS_MPTPR_2BK_8K, 4148 CONFIG_SYS_MPTPR_1BK_8K, CONFIG_SYS_MAMR_8COL, CONFIG_SYS_MAMR_9COL: 4149 Machine Mode Register and Memory Periodic Timer 4150 Prescaler definitions (SDRAM timing) 4151 4152- CONFIG_SYS_I2C_UCODE_PATCH, CONFIG_SYS_I2C_DPMEM_OFFSET [0x1FC0]: 4153 enable I2C microcode relocation patch (MPC8xx); 4154 define relocation offset in DPRAM [DSP2] 4155 4156- CONFIG_SYS_SMC_UCODE_PATCH, CONFIG_SYS_SMC_DPMEM_OFFSET [0x1FC0]: 4157 enable SMC microcode relocation patch (MPC8xx); 4158 define relocation offset in DPRAM [SMC1] 4159 4160- CONFIG_SYS_SPI_UCODE_PATCH, CONFIG_SYS_SPI_DPMEM_OFFSET [0x1FC0]: 4161 enable SPI microcode relocation patch (MPC8xx); 4162 define relocation offset in DPRAM [SCC4] 4163 4164- CONFIG_SYS_CPM_POST_WORD_ADDR: (MPC8xx, MPC8260 only) 4165 Offset of the bootmode word in DPRAM used by post 4166 (Power On Self Tests). This definition overrides 4167 #define'd default value in commproc.h resp. 4168 cpm_8260.h. 4169 4170- CONFIG_SYS_PCI_SLV_MEM_LOCAL, CONFIG_SYS_PCI_SLV_MEM_BUS, CONFIG_SYS_PICMR0_MASK_ATTRIB, 4171 CONFIG_SYS_PCI_MSTR0_LOCAL, CONFIG_SYS_PCIMSK0_MASK, CONFIG_SYS_PCI_MSTR1_LOCAL, 4172 CONFIG_SYS_PCIMSK1_MASK, CONFIG_SYS_PCI_MSTR_MEM_LOCAL, CONFIG_SYS_PCI_MSTR_MEM_BUS, 4173 CONFIG_SYS_CPU_PCI_MEM_START, CONFIG_SYS_PCI_MSTR_MEM_SIZE, CONFIG_SYS_POCMR0_MASK_ATTRIB, 4174 CONFIG_SYS_PCI_MSTR_MEMIO_LOCAL, CONFIG_SYS_PCI_MSTR_MEMIO_BUS, CPU_PCI_MEMIO_START, 4175 CONFIG_SYS_PCI_MSTR_MEMIO_SIZE, CONFIG_SYS_POCMR1_MASK_ATTRIB, CONFIG_SYS_PCI_MSTR_IO_LOCAL, 4176 CONFIG_SYS_PCI_MSTR_IO_BUS, CONFIG_SYS_CPU_PCI_IO_START, CONFIG_SYS_PCI_MSTR_IO_SIZE, 4177 CONFIG_SYS_POCMR2_MASK_ATTRIB: (MPC826x only) 4178 Overrides the default PCI memory map in arch/powerpc/cpu/mpc8260/pci.c if set. 4179 4180- CONFIG_PCI_DISABLE_PCIE: 4181 Disable PCI-Express on systems where it is supported but not 4182 required. 4183 4184- CONFIG_PCI_ENUM_ONLY 4185 Only scan through and get the devices on the buses. 4186 Don't do any setup work, presumably because someone or 4187 something has already done it, and we don't need to do it 4188 a second time. Useful for platforms that are pre-booted 4189 by coreboot or similar. 4190 4191- CONFIG_PCI_INDIRECT_BRIDGE: 4192 Enable support for indirect PCI bridges. 4193 4194- CONFIG_SYS_SRIO: 4195 Chip has SRIO or not 4196 4197- CONFIG_SRIO1: 4198 Board has SRIO 1 port available 4199 4200- CONFIG_SRIO2: 4201 Board has SRIO 2 port available 4202 4203- CONFIG_SRIO_PCIE_BOOT_MASTER 4204 Board can support master function for Boot from SRIO and PCIE 4205 4206- CONFIG_SYS_SRIOn_MEM_VIRT: 4207 Virtual Address of SRIO port 'n' memory region 4208 4209- CONFIG_SYS_SRIOn_MEM_PHYS: 4210 Physical Address of SRIO port 'n' memory region 4211 4212- CONFIG_SYS_SRIOn_MEM_SIZE: 4213 Size of SRIO port 'n' memory region 4214 4215- CONFIG_SYS_NAND_BUSWIDTH_16BIT 4216 Defined to tell the NAND controller that the NAND chip is using 4217 a 16 bit bus. 4218 Not all NAND drivers use this symbol. 4219 Example of drivers that use it: 4220 - drivers/mtd/nand/ndfc.c 4221 - drivers/mtd/nand/mxc_nand.c 4222 4223- CONFIG_SYS_NDFC_EBC0_CFG 4224 Sets the EBC0_CFG register for the NDFC. If not defined 4225 a default value will be used. 4226 4227- CONFIG_SPD_EEPROM 4228 Get DDR timing information from an I2C EEPROM. Common 4229 with pluggable memory modules such as SODIMMs 4230 4231 SPD_EEPROM_ADDRESS 4232 I2C address of the SPD EEPROM 4233 4234- CONFIG_SYS_SPD_BUS_NUM 4235 If SPD EEPROM is on an I2C bus other than the first 4236 one, specify here. Note that the value must resolve 4237 to something your driver can deal with. 4238 4239- CONFIG_SYS_DDR_RAW_TIMING 4240 Get DDR timing information from other than SPD. Common with 4241 soldered DDR chips onboard without SPD. DDR raw timing 4242 parameters are extracted from datasheet and hard-coded into 4243 header files or board specific files. 4244 4245- CONFIG_FSL_DDR_INTERACTIVE 4246 Enable interactive DDR debugging. See doc/README.fsl-ddr. 4247 4248- CONFIG_FSL_DDR_SYNC_REFRESH 4249 Enable sync of refresh for multiple controllers. 4250 4251- CONFIG_FSL_DDR_BIST 4252 Enable built-in memory test for Freescale DDR controllers. 4253 4254- CONFIG_SYS_83XX_DDR_USES_CS0 4255 Only for 83xx systems. If specified, then DDR should 4256 be configured using CS0 and CS1 instead of CS2 and CS3. 4257 4258- CONFIG_ETHER_ON_FEC[12] 4259 Define to enable FEC[12] on a 8xx series processor. 4260 4261- CONFIG_FEC[12]_PHY 4262 Define to the hardcoded PHY address which corresponds 4263 to the given FEC; i. e. 4264 #define CONFIG_FEC1_PHY 4 4265 means that the PHY with address 4 is connected to FEC1 4266 4267 When set to -1, means to probe for first available. 4268 4269- CONFIG_FEC[12]_PHY_NORXERR 4270 The PHY does not have a RXERR line (RMII only). 4271 (so program the FEC to ignore it). 4272 4273- CONFIG_RMII 4274 Enable RMII mode for all FECs. 4275 Note that this is a global option, we can't 4276 have one FEC in standard MII mode and another in RMII mode. 4277 4278- CONFIG_CRC32_VERIFY 4279 Add a verify option to the crc32 command. 4280 The syntax is: 4281 4282 => crc32 -v <address> <count> <crc32> 4283 4284 Where address/count indicate a memory area 4285 and crc32 is the correct crc32 which the 4286 area should have. 4287 4288- CONFIG_LOOPW 4289 Add the "loopw" memory command. This only takes effect if 4290 the memory commands are activated globally (CONFIG_CMD_MEM). 4291 4292- CONFIG_MX_CYCLIC 4293 Add the "mdc" and "mwc" memory commands. These are cyclic 4294 "md/mw" commands. 4295 Examples: 4296 4297 => mdc.b 10 4 500 4298 This command will print 4 bytes (10,11,12,13) each 500 ms. 4299 4300 => mwc.l 100 12345678 10 4301 This command will write 12345678 to address 100 all 10 ms. 4302 4303 This only takes effect if the memory commands are activated 4304 globally (CONFIG_CMD_MEM). 4305 4306- CONFIG_SKIP_LOWLEVEL_INIT 4307 [ARM, NDS32, MIPS only] If this variable is defined, then certain 4308 low level initializations (like setting up the memory 4309 controller) are omitted and/or U-Boot does not 4310 relocate itself into RAM. 4311 4312 Normally this variable MUST NOT be defined. The only 4313 exception is when U-Boot is loaded (to RAM) by some 4314 other boot loader or by a debugger which performs 4315 these initializations itself. 4316 4317- CONFIG_SKIP_LOWLEVEL_INIT_ONLY 4318 [ARM926EJ-S only] This allows just the call to lowlevel_init() 4319 to be skipped. The normal CP15 init (such as enabling the 4320 instruction cache) is still performed. 4321 4322- CONFIG_SPL_BUILD 4323 Modifies the behaviour of start.S when compiling a loader 4324 that is executed before the actual U-Boot. E.g. when 4325 compiling a NAND SPL. 4326 4327- CONFIG_TPL_BUILD 4328 Modifies the behaviour of start.S when compiling a loader 4329 that is executed after the SPL and before the actual U-Boot. 4330 It is loaded by the SPL. 4331 4332- CONFIG_SYS_MPC85XX_NO_RESETVEC 4333 Only for 85xx systems. If this variable is specified, the section 4334 .resetvec is not kept and the section .bootpg is placed in the 4335 previous 4k of the .text section. 4336 4337- CONFIG_ARCH_MAP_SYSMEM 4338 Generally U-Boot (and in particular the md command) uses 4339 effective address. It is therefore not necessary to regard 4340 U-Boot address as virtual addresses that need to be translated 4341 to physical addresses. However, sandbox requires this, since 4342 it maintains its own little RAM buffer which contains all 4343 addressable memory. This option causes some memory accesses 4344 to be mapped through map_sysmem() / unmap_sysmem(). 4345 4346- CONFIG_X86_RESET_VECTOR 4347 If defined, the x86 reset vector code is included. This is not 4348 needed when U-Boot is running from Coreboot. 4349 4350- CONFIG_SPL_AM33XX_ENABLE_RTC32K_OSC: 4351 Enables the RTC32K OSC on AM33xx based plattforms 4352 4353- CONFIG_SYS_NAND_NO_SUBPAGE_WRITE 4354 Option to disable subpage write in NAND driver 4355 driver that uses this: 4356 drivers/mtd/nand/davinci_nand.c 4357 4358Freescale QE/FMAN Firmware Support: 4359----------------------------------- 4360 4361The Freescale QUICCEngine (QE) and Frame Manager (FMAN) both support the 4362loading of "firmware", which is encoded in the QE firmware binary format. 4363This firmware often needs to be loaded during U-Boot booting, so macros 4364are used to identify the storage device (NOR flash, SPI, etc) and the address 4365within that device. 4366 4367- CONFIG_SYS_FMAN_FW_ADDR 4368 The address in the storage device where the FMAN microcode is located. The 4369 meaning of this address depends on which CONFIG_SYS_QE_FW_IN_xxx macro 4370 is also specified. 4371 4372- CONFIG_SYS_QE_FW_ADDR 4373 The address in the storage device where the QE microcode is located. The 4374 meaning of this address depends on which CONFIG_SYS_QE_FW_IN_xxx macro 4375 is also specified. 4376 4377- CONFIG_SYS_QE_FMAN_FW_LENGTH 4378 The maximum possible size of the firmware. The firmware binary format 4379 has a field that specifies the actual size of the firmware, but it 4380 might not be possible to read any part of the firmware unless some 4381 local storage is allocated to hold the entire firmware first. 4382 4383- CONFIG_SYS_QE_FMAN_FW_IN_NOR 4384 Specifies that QE/FMAN firmware is located in NOR flash, mapped as 4385 normal addressable memory via the LBC. CONFIG_SYS_FMAN_FW_ADDR is the 4386 virtual address in NOR flash. 4387 4388- CONFIG_SYS_QE_FMAN_FW_IN_NAND 4389 Specifies that QE/FMAN firmware is located in NAND flash. 4390 CONFIG_SYS_FMAN_FW_ADDR is the offset within NAND flash. 4391 4392- CONFIG_SYS_QE_FMAN_FW_IN_MMC 4393 Specifies that QE/FMAN firmware is located on the primary SD/MMC 4394 device. CONFIG_SYS_FMAN_FW_ADDR is the byte offset on that device. 4395 4396- CONFIG_SYS_QE_FMAN_FW_IN_REMOTE 4397 Specifies that QE/FMAN firmware is located in the remote (master) 4398 memory space. CONFIG_SYS_FMAN_FW_ADDR is a virtual address which 4399 can be mapped from slave TLB->slave LAW->slave SRIO or PCIE outbound 4400 window->master inbound window->master LAW->the ucode address in 4401 master's memory space. 4402 4403Freescale Layerscape Management Complex Firmware Support: 4404--------------------------------------------------------- 4405The Freescale Layerscape Management Complex (MC) supports the loading of 4406"firmware". 4407This firmware often needs to be loaded during U-Boot booting, so macros 4408are used to identify the storage device (NOR flash, SPI, etc) and the address 4409within that device. 4410 4411- CONFIG_FSL_MC_ENET 4412 Enable the MC driver for Layerscape SoCs. 4413 4414Freescale Layerscape Debug Server Support: 4415------------------------------------------- 4416The Freescale Layerscape Debug Server Support supports the loading of 4417"Debug Server firmware" and triggering SP boot-rom. 4418This firmware often needs to be loaded during U-Boot booting. 4419 4420- CONFIG_SYS_MC_RSV_MEM_ALIGN 4421 Define alignment of reserved memory MC requires 4422 4423Reproducible builds 4424------------------- 4425 4426In order to achieve reproducible builds, timestamps used in the U-Boot build 4427process have to be set to a fixed value. 4428 4429This is done using the SOURCE_DATE_EPOCH environment variable. 4430SOURCE_DATE_EPOCH is to be set on the build host's shell, not as a configuration 4431option for U-Boot or an environment variable in U-Boot. 4432 4433SOURCE_DATE_EPOCH should be set to a number of seconds since the epoch, in UTC. 4434 4435Building the Software: 4436====================== 4437 4438Building U-Boot has been tested in several native build environments 4439and in many different cross environments. Of course we cannot support 4440all possibly existing versions of cross development tools in all 4441(potentially obsolete) versions. In case of tool chain problems we 4442recommend to use the ELDK (see http://www.denx.de/wiki/DULG/ELDK) 4443which is extensively used to build and test U-Boot. 4444 4445If you are not using a native environment, it is assumed that you 4446have GNU cross compiling tools available in your path. In this case, 4447you must set the environment variable CROSS_COMPILE in your shell. 4448Note that no changes to the Makefile or any other source files are 4449necessary. For example using the ELDK on a 4xx CPU, please enter: 4450 4451 $ CROSS_COMPILE=ppc_4xx- 4452 $ export CROSS_COMPILE 4453 4454Note: If you wish to generate Windows versions of the utilities in 4455 the tools directory you can use the MinGW toolchain 4456 (http://www.mingw.org). Set your HOST tools to the MinGW 4457 toolchain and execute 'make tools'. For example: 4458 4459 $ make HOSTCC=i586-mingw32msvc-gcc HOSTSTRIP=i586-mingw32msvc-strip tools 4460 4461 Binaries such as tools/mkimage.exe will be created which can 4462 be executed on computers running Windows. 4463 4464U-Boot is intended to be simple to build. After installing the 4465sources you must configure U-Boot for one specific board type. This 4466is done by typing: 4467 4468 make NAME_defconfig 4469 4470where "NAME_defconfig" is the name of one of the existing configu- 4471rations; see boards.cfg for supported names. 4472 4473Note: for some board special configuration names may exist; check if 4474 additional information is available from the board vendor; for 4475 instance, the TQM823L systems are available without (standard) 4476 or with LCD support. You can select such additional "features" 4477 when choosing the configuration, i. e. 4478 4479 make TQM823L_defconfig 4480 - will configure for a plain TQM823L, i. e. no LCD support 4481 4482 make TQM823L_LCD_defconfig 4483 - will configure for a TQM823L with U-Boot console on LCD 4484 4485 etc. 4486 4487 4488Finally, type "make all", and you should get some working U-Boot 4489images ready for download to / installation on your system: 4490 4491- "u-boot.bin" is a raw binary image 4492- "u-boot" is an image in ELF binary format 4493- "u-boot.srec" is in Motorola S-Record format 4494 4495By default the build is performed locally and the objects are saved 4496in the source directory. One of the two methods can be used to change 4497this behavior and build U-Boot to some external directory: 4498 44991. Add O= to the make command line invocations: 4500 4501 make O=/tmp/build distclean 4502 make O=/tmp/build NAME_defconfig 4503 make O=/tmp/build all 4504 45052. Set environment variable KBUILD_OUTPUT to point to the desired location: 4506 4507 export KBUILD_OUTPUT=/tmp/build 4508 make distclean 4509 make NAME_defconfig 4510 make all 4511 4512Note that the command line "O=" setting overrides the KBUILD_OUTPUT environment 4513variable. 4514 4515 4516Please be aware that the Makefiles assume you are using GNU make, so 4517for instance on NetBSD you might need to use "gmake" instead of 4518native "make". 4519 4520 4521If the system board that you have is not listed, then you will need 4522to port U-Boot to your hardware platform. To do this, follow these 4523steps: 4524 45251. Create a new directory to hold your board specific code. Add any 4526 files you need. In your board directory, you will need at least 4527 the "Makefile" and a "<board>.c". 45282. Create a new configuration file "include/configs/<board>.h" for 4529 your board. 45303. If you're porting U-Boot to a new CPU, then also create a new 4531 directory to hold your CPU specific code. Add any files you need. 45324. Run "make <board>_defconfig" with your new name. 45335. Type "make", and you should get a working "u-boot.srec" file 4534 to be installed on your target system. 45356. Debug and solve any problems that might arise. 4536 [Of course, this last step is much harder than it sounds.] 4537 4538 4539Testing of U-Boot Modifications, Ports to New Hardware, etc.: 4540============================================================== 4541 4542If you have modified U-Boot sources (for instance added a new board 4543or support for new devices, a new CPU, etc.) you are expected to 4544provide feedback to the other developers. The feedback normally takes 4545the form of a "patch", i. e. a context diff against a certain (latest 4546official or latest in the git repository) version of U-Boot sources. 4547 4548But before you submit such a patch, please verify that your modifi- 4549cation did not break existing code. At least make sure that *ALL* of 4550the supported boards compile WITHOUT ANY compiler warnings. To do so, 4551just run the buildman script (tools/buildman/buildman), which will 4552configure and build U-Boot for ALL supported system. Be warned, this 4553will take a while. Please see the buildman README, or run 'buildman -H' 4554for documentation. 4555 4556 4557See also "U-Boot Porting Guide" below. 4558 4559 4560Monitor Commands - Overview: 4561============================ 4562 4563go - start application at address 'addr' 4564run - run commands in an environment variable 4565bootm - boot application image from memory 4566bootp - boot image via network using BootP/TFTP protocol 4567bootz - boot zImage from memory 4568tftpboot- boot image via network using TFTP protocol 4569 and env variables "ipaddr" and "serverip" 4570 (and eventually "gatewayip") 4571tftpput - upload a file via network using TFTP protocol 4572rarpboot- boot image via network using RARP/TFTP protocol 4573diskboot- boot from IDE devicebootd - boot default, i.e., run 'bootcmd' 4574loads - load S-Record file over serial line 4575loadb - load binary file over serial line (kermit mode) 4576md - memory display 4577mm - memory modify (auto-incrementing) 4578nm - memory modify (constant address) 4579mw - memory write (fill) 4580cp - memory copy 4581cmp - memory compare 4582crc32 - checksum calculation 4583i2c - I2C sub-system 4584sspi - SPI utility commands 4585base - print or set address offset 4586printenv- print environment variables 4587setenv - set environment variables 4588saveenv - save environment variables to persistent storage 4589protect - enable or disable FLASH write protection 4590erase - erase FLASH memory 4591flinfo - print FLASH memory information 4592nand - NAND memory operations (see doc/README.nand) 4593bdinfo - print Board Info structure 4594iminfo - print header information for application image 4595coninfo - print console devices and informations 4596ide - IDE sub-system 4597loop - infinite loop on address range 4598loopw - infinite write loop on address range 4599mtest - simple RAM test 4600icache - enable or disable instruction cache 4601dcache - enable or disable data cache 4602reset - Perform RESET of the CPU 4603echo - echo args to console 4604version - print monitor version 4605help - print online help 4606? - alias for 'help' 4607 4608 4609Monitor Commands - Detailed Description: 4610======================================== 4611 4612TODO. 4613 4614For now: just type "help <command>". 4615 4616 4617Environment Variables: 4618====================== 4619 4620U-Boot supports user configuration using Environment Variables which 4621can be made persistent by saving to Flash memory. 4622 4623Environment Variables are set using "setenv", printed using 4624"printenv", and saved to Flash using "saveenv". Using "setenv" 4625without a value can be used to delete a variable from the 4626environment. As long as you don't save the environment you are 4627working with an in-memory copy. In case the Flash area containing the 4628environment is erased by accident, a default environment is provided. 4629 4630Some configuration options can be set using Environment Variables. 4631 4632List of environment variables (most likely not complete): 4633 4634 baudrate - see CONFIG_BAUDRATE 4635 4636 bootdelay - see CONFIG_BOOTDELAY 4637 4638 bootcmd - see CONFIG_BOOTCOMMAND 4639 4640 bootargs - Boot arguments when booting an RTOS image 4641 4642 bootfile - Name of the image to load with TFTP 4643 4644 bootm_low - Memory range available for image processing in the bootm 4645 command can be restricted. This variable is given as 4646 a hexadecimal number and defines lowest address allowed 4647 for use by the bootm command. See also "bootm_size" 4648 environment variable. Address defined by "bootm_low" is 4649 also the base of the initial memory mapping for the Linux 4650 kernel -- see the description of CONFIG_SYS_BOOTMAPSZ and 4651 bootm_mapsize. 4652 4653 bootm_mapsize - Size of the initial memory mapping for the Linux kernel. 4654 This variable is given as a hexadecimal number and it 4655 defines the size of the memory region starting at base 4656 address bootm_low that is accessible by the Linux kernel 4657 during early boot. If unset, CONFIG_SYS_BOOTMAPSZ is used 4658 as the default value if it is defined, and bootm_size is 4659 used otherwise. 4660 4661 bootm_size - Memory range available for image processing in the bootm 4662 command can be restricted. This variable is given as 4663 a hexadecimal number and defines the size of the region 4664 allowed for use by the bootm command. See also "bootm_low" 4665 environment variable. 4666 4667 updatefile - Location of the software update file on a TFTP server, used 4668 by the automatic software update feature. Please refer to 4669 documentation in doc/README.update for more details. 4670 4671 autoload - if set to "no" (any string beginning with 'n'), 4672 "bootp" will just load perform a lookup of the 4673 configuration from the BOOTP server, but not try to 4674 load any image using TFTP 4675 4676 autostart - if set to "yes", an image loaded using the "bootp", 4677 "rarpboot", "tftpboot" or "diskboot" commands will 4678 be automatically started (by internally calling 4679 "bootm") 4680 4681 If set to "no", a standalone image passed to the 4682 "bootm" command will be copied to the load address 4683 (and eventually uncompressed), but NOT be started. 4684 This can be used to load and uncompress arbitrary 4685 data. 4686 4687 fdt_high - if set this restricts the maximum address that the 4688 flattened device tree will be copied into upon boot. 4689 For example, if you have a system with 1 GB memory 4690 at physical address 0x10000000, while Linux kernel 4691 only recognizes the first 704 MB as low memory, you 4692 may need to set fdt_high as 0x3C000000 to have the 4693 device tree blob be copied to the maximum address 4694 of the 704 MB low memory, so that Linux kernel can 4695 access it during the boot procedure. 4696 4697 If this is set to the special value 0xFFFFFFFF then 4698 the fdt will not be copied at all on boot. For this 4699 to work it must reside in writable memory, have 4700 sufficient padding on the end of it for u-boot to 4701 add the information it needs into it, and the memory 4702 must be accessible by the kernel. 4703 4704 fdtcontroladdr- if set this is the address of the control flattened 4705 device tree used by U-Boot when CONFIG_OF_CONTROL is 4706 defined. 4707 4708 i2cfast - (PPC405GP|PPC405EP only) 4709 if set to 'y' configures Linux I2C driver for fast 4710 mode (400kHZ). This environment variable is used in 4711 initialization code. So, for changes to be effective 4712 it must be saved and board must be reset. 4713 4714 initrd_high - restrict positioning of initrd images: 4715 If this variable is not set, initrd images will be 4716 copied to the highest possible address in RAM; this 4717 is usually what you want since it allows for 4718 maximum initrd size. If for some reason you want to 4719 make sure that the initrd image is loaded below the 4720 CONFIG_SYS_BOOTMAPSZ limit, you can set this environment 4721 variable to a value of "no" or "off" or "0". 4722 Alternatively, you can set it to a maximum upper 4723 address to use (U-Boot will still check that it 4724 does not overwrite the U-Boot stack and data). 4725 4726 For instance, when you have a system with 16 MB 4727 RAM, and want to reserve 4 MB from use by Linux, 4728 you can do this by adding "mem=12M" to the value of 4729 the "bootargs" variable. However, now you must make 4730 sure that the initrd image is placed in the first 4731 12 MB as well - this can be done with 4732 4733 setenv initrd_high 00c00000 4734 4735 If you set initrd_high to 0xFFFFFFFF, this is an 4736 indication to U-Boot that all addresses are legal 4737 for the Linux kernel, including addresses in flash 4738 memory. In this case U-Boot will NOT COPY the 4739 ramdisk at all. This may be useful to reduce the 4740 boot time on your system, but requires that this 4741 feature is supported by your Linux kernel. 4742 4743 ipaddr - IP address; needed for tftpboot command 4744 4745 loadaddr - Default load address for commands like "bootp", 4746 "rarpboot", "tftpboot", "loadb" or "diskboot" 4747 4748 loads_echo - see CONFIG_LOADS_ECHO 4749 4750 serverip - TFTP server IP address; needed for tftpboot command 4751 4752 bootretry - see CONFIG_BOOT_RETRY_TIME 4753 4754 bootdelaykey - see CONFIG_AUTOBOOT_DELAY_STR 4755 4756 bootstopkey - see CONFIG_AUTOBOOT_STOP_STR 4757 4758 ethprime - controls which interface is used first. 4759 4760 ethact - controls which interface is currently active. 4761 For example you can do the following 4762 4763 => setenv ethact FEC 4764 => ping 192.168.0.1 # traffic sent on FEC 4765 => setenv ethact SCC 4766 => ping 10.0.0.1 # traffic sent on SCC 4767 4768 ethrotate - When set to "no" U-Boot does not go through all 4769 available network interfaces. 4770 It just stays at the currently selected interface. 4771 4772 netretry - When set to "no" each network operation will 4773 either succeed or fail without retrying. 4774 When set to "once" the network operation will 4775 fail when all the available network interfaces 4776 are tried once without success. 4777 Useful on scripts which control the retry operation 4778 themselves. 4779 4780 npe_ucode - set load address for the NPE microcode 4781 4782 silent_linux - If set then Linux will be told to boot silently, by 4783 changing the console to be empty. If "yes" it will be 4784 made silent. If "no" it will not be made silent. If 4785 unset, then it will be made silent if the U-Boot console 4786 is silent. 4787 4788 tftpsrcp - If this is set, the value is used for TFTP's 4789 UDP source port. 4790 4791 tftpdstp - If this is set, the value is used for TFTP's UDP 4792 destination port instead of the Well Know Port 69. 4793 4794 tftpblocksize - Block size to use for TFTP transfers; if not set, 4795 we use the TFTP server's default block size 4796 4797 tftptimeout - Retransmission timeout for TFTP packets (in milli- 4798 seconds, minimum value is 1000 = 1 second). Defines 4799 when a packet is considered to be lost so it has to 4800 be retransmitted. The default is 5000 = 5 seconds. 4801 Lowering this value may make downloads succeed 4802 faster in networks with high packet loss rates or 4803 with unreliable TFTP servers. 4804 4805 tftptimeoutcountmax - maximum count of TFTP timeouts (no 4806 unit, minimum value = 0). Defines how many timeouts 4807 can happen during a single file transfer before that 4808 transfer is aborted. The default is 10, and 0 means 4809 'no timeouts allowed'. Increasing this value may help 4810 downloads succeed with high packet loss rates, or with 4811 unreliable TFTP servers or client hardware. 4812 4813 vlan - When set to a value < 4095 the traffic over 4814 Ethernet is encapsulated/received over 802.1q 4815 VLAN tagged frames. 4816 4817 bootpretryperiod - Period during which BOOTP/DHCP sends retries. 4818 Unsigned value, in milliseconds. If not set, the period will 4819 be either the default (28000), or a value based on 4820 CONFIG_NET_RETRY_COUNT, if defined. This value has 4821 precedence over the valu based on CONFIG_NET_RETRY_COUNT. 4822 4823The following image location variables contain the location of images 4824used in booting. The "Image" column gives the role of the image and is 4825not an environment variable name. The other columns are environment 4826variable names. "File Name" gives the name of the file on a TFTP 4827server, "RAM Address" gives the location in RAM the image will be 4828loaded to, and "Flash Location" gives the image's address in NOR 4829flash or offset in NAND flash. 4830 4831*Note* - these variables don't have to be defined for all boards, some 4832boards currently use other variables for these purposes, and some 4833boards use these variables for other purposes. 4834 4835Image File Name RAM Address Flash Location 4836----- --------- ----------- -------------- 4837u-boot u-boot u-boot_addr_r u-boot_addr 4838Linux kernel bootfile kernel_addr_r kernel_addr 4839device tree blob fdtfile fdt_addr_r fdt_addr 4840ramdisk ramdiskfile ramdisk_addr_r ramdisk_addr 4841 4842The following environment variables may be used and automatically 4843updated by the network boot commands ("bootp" and "rarpboot"), 4844depending the information provided by your boot server: 4845 4846 bootfile - see above 4847 dnsip - IP address of your Domain Name Server 4848 dnsip2 - IP address of your secondary Domain Name Server 4849 gatewayip - IP address of the Gateway (Router) to use 4850 hostname - Target hostname 4851 ipaddr - see above 4852 netmask - Subnet Mask 4853 rootpath - Pathname of the root filesystem on the NFS server 4854 serverip - see above 4855 4856 4857There are two special Environment Variables: 4858 4859 serial# - contains hardware identification information such 4860 as type string and/or serial number 4861 ethaddr - Ethernet address 4862 4863These variables can be set only once (usually during manufacturing of 4864the board). U-Boot refuses to delete or overwrite these variables 4865once they have been set once. 4866 4867 4868Further special Environment Variables: 4869 4870 ver - Contains the U-Boot version string as printed 4871 with the "version" command. This variable is 4872 readonly (see CONFIG_VERSION_VARIABLE). 4873 4874 4875Please note that changes to some configuration parameters may take 4876only effect after the next boot (yes, that's just like Windoze :-). 4877 4878 4879Callback functions for environment variables: 4880--------------------------------------------- 4881 4882For some environment variables, the behavior of u-boot needs to change 4883when their values are changed. This functionality allows functions to 4884be associated with arbitrary variables. On creation, overwrite, or 4885deletion, the callback will provide the opportunity for some side 4886effect to happen or for the change to be rejected. 4887 4888The callbacks are named and associated with a function using the 4889U_BOOT_ENV_CALLBACK macro in your board or driver code. 4890 4891These callbacks are associated with variables in one of two ways. The 4892static list can be added to by defining CONFIG_ENV_CALLBACK_LIST_STATIC 4893in the board configuration to a string that defines a list of 4894associations. The list must be in the following format: 4895 4896 entry = variable_name[:callback_name] 4897 list = entry[,list] 4898 4899If the callback name is not specified, then the callback is deleted. 4900Spaces are also allowed anywhere in the list. 4901 4902Callbacks can also be associated by defining the ".callbacks" variable 4903with the same list format above. Any association in ".callbacks" will 4904override any association in the static list. You can define 4905CONFIG_ENV_CALLBACK_LIST_DEFAULT to a list (string) to define the 4906".callbacks" environment variable in the default or embedded environment. 4907 4908If CONFIG_REGEX is defined, the variable_name above is evaluated as a 4909regular expression. This allows multiple variables to be connected to 4910the same callback without explicitly listing them all out. 4911 4912 4913Command Line Parsing: 4914===================== 4915 4916There are two different command line parsers available with U-Boot: 4917the old "simple" one, and the much more powerful "hush" shell: 4918 4919Old, simple command line parser: 4920-------------------------------- 4921 4922- supports environment variables (through setenv / saveenv commands) 4923- several commands on one line, separated by ';' 4924- variable substitution using "... ${name} ..." syntax 4925- special characters ('$', ';') can be escaped by prefixing with '\', 4926 for example: 4927 setenv bootcmd bootm \${address} 4928- You can also escape text by enclosing in single apostrophes, for example: 4929 setenv addip 'setenv bootargs $bootargs ip=$ipaddr:$serverip:$gatewayip:$netmask:$hostname::off' 4930 4931Hush shell: 4932----------- 4933 4934- similar to Bourne shell, with control structures like 4935 if...then...else...fi, for...do...done; while...do...done, 4936 until...do...done, ... 4937- supports environment ("global") variables (through setenv / saveenv 4938 commands) and local shell variables (through standard shell syntax 4939 "name=value"); only environment variables can be used with "run" 4940 command 4941 4942General rules: 4943-------------- 4944 4945(1) If a command line (or an environment variable executed by a "run" 4946 command) contains several commands separated by semicolon, and 4947 one of these commands fails, then the remaining commands will be 4948 executed anyway. 4949 4950(2) If you execute several variables with one call to run (i. e. 4951 calling run with a list of variables as arguments), any failing 4952 command will cause "run" to terminate, i. e. the remaining 4953 variables are not executed. 4954 4955Note for Redundant Ethernet Interfaces: 4956======================================= 4957 4958Some boards come with redundant Ethernet interfaces; U-Boot supports 4959such configurations and is capable of automatic selection of a 4960"working" interface when needed. MAC assignment works as follows: 4961 4962Network interfaces are numbered eth0, eth1, eth2, ... Corresponding 4963MAC addresses can be stored in the environment as "ethaddr" (=>eth0), 4964"eth1addr" (=>eth1), "eth2addr", ... 4965 4966If the network interface stores some valid MAC address (for instance 4967in SROM), this is used as default address if there is NO correspon- 4968ding setting in the environment; if the corresponding environment 4969variable is set, this overrides the settings in the card; that means: 4970 4971o If the SROM has a valid MAC address, and there is no address in the 4972 environment, the SROM's address is used. 4973 4974o If there is no valid address in the SROM, and a definition in the 4975 environment exists, then the value from the environment variable is 4976 used. 4977 4978o If both the SROM and the environment contain a MAC address, and 4979 both addresses are the same, this MAC address is used. 4980 4981o If both the SROM and the environment contain a MAC address, and the 4982 addresses differ, the value from the environment is used and a 4983 warning is printed. 4984 4985o If neither SROM nor the environment contain a MAC address, an error 4986 is raised. If CONFIG_NET_RANDOM_ETHADDR is defined, then in this case 4987 a random, locally-assigned MAC is used. 4988 4989If Ethernet drivers implement the 'write_hwaddr' function, valid MAC addresses 4990will be programmed into hardware as part of the initialization process. This 4991may be skipped by setting the appropriate 'ethmacskip' environment variable. 4992The naming convention is as follows: 4993"ethmacskip" (=>eth0), "eth1macskip" (=>eth1) etc. 4994 4995Image Formats: 4996============== 4997 4998U-Boot is capable of booting (and performing other auxiliary operations on) 4999images in two formats: 5000 5001New uImage format (FIT) 5002----------------------- 5003 5004Flexible and powerful format based on Flattened Image Tree -- FIT (similar 5005to Flattened Device Tree). It allows the use of images with multiple 5006components (several kernels, ramdisks, etc.), with contents protected by 5007SHA1, MD5 or CRC32. More details are found in the doc/uImage.FIT directory. 5008 5009 5010Old uImage format 5011----------------- 5012 5013Old image format is based on binary files which can be basically anything, 5014preceded by a special header; see the definitions in include/image.h for 5015details; basically, the header defines the following image properties: 5016 5017* Target Operating System (Provisions for OpenBSD, NetBSD, FreeBSD, 5018 4.4BSD, Linux, SVR4, Esix, Solaris, Irix, SCO, Dell, NCR, VxWorks, 5019 LynxOS, pSOS, QNX, RTEMS, INTEGRITY; 5020 Currently supported: Linux, NetBSD, VxWorks, QNX, RTEMS, LynxOS, 5021 INTEGRITY). 5022* Target CPU Architecture (Provisions for Alpha, ARM, AVR32, Intel x86, 5023 IA64, MIPS, NDS32, Nios II, PowerPC, IBM S390, SuperH, Sparc, Sparc 64 Bit; 5024 Currently supported: ARM, AVR32, Intel x86, MIPS, NDS32, Nios II, PowerPC). 5025* Compression Type (uncompressed, gzip, bzip2) 5026* Load Address 5027* Entry Point 5028* Image Name 5029* Image Timestamp 5030 5031The header is marked by a special Magic Number, and both the header 5032and the data portions of the image are secured against corruption by 5033CRC32 checksums. 5034 5035 5036Linux Support: 5037============== 5038 5039Although U-Boot should support any OS or standalone application 5040easily, the main focus has always been on Linux during the design of 5041U-Boot. 5042 5043U-Boot includes many features that so far have been part of some 5044special "boot loader" code within the Linux kernel. Also, any 5045"initrd" images to be used are no longer part of one big Linux image; 5046instead, kernel and "initrd" are separate images. This implementation 5047serves several purposes: 5048 5049- the same features can be used for other OS or standalone 5050 applications (for instance: using compressed images to reduce the 5051 Flash memory footprint) 5052 5053- it becomes much easier to port new Linux kernel versions because 5054 lots of low-level, hardware dependent stuff are done by U-Boot 5055 5056- the same Linux kernel image can now be used with different "initrd" 5057 images; of course this also means that different kernel images can 5058 be run with the same "initrd". This makes testing easier (you don't 5059 have to build a new "zImage.initrd" Linux image when you just 5060 change a file in your "initrd"). Also, a field-upgrade of the 5061 software is easier now. 5062 5063 5064Linux HOWTO: 5065============ 5066 5067Porting Linux to U-Boot based systems: 5068--------------------------------------- 5069 5070U-Boot cannot save you from doing all the necessary modifications to 5071configure the Linux device drivers for use with your target hardware 5072(no, we don't intend to provide a full virtual machine interface to 5073Linux :-). 5074 5075But now you can ignore ALL boot loader code (in arch/powerpc/mbxboot). 5076 5077Just make sure your machine specific header file (for instance 5078include/asm-ppc/tqm8xx.h) includes the same definition of the Board 5079Information structure as we define in include/asm-<arch>/u-boot.h, 5080and make sure that your definition of IMAP_ADDR uses the same value 5081as your U-Boot configuration in CONFIG_SYS_IMMR. 5082 5083Note that U-Boot now has a driver model, a unified model for drivers. 5084If you are adding a new driver, plumb it into driver model. If there 5085is no uclass available, you are encouraged to create one. See 5086doc/driver-model. 5087 5088 5089Configuring the Linux kernel: 5090----------------------------- 5091 5092No specific requirements for U-Boot. Make sure you have some root 5093device (initial ramdisk, NFS) for your target system. 5094 5095 5096Building a Linux Image: 5097----------------------- 5098 5099With U-Boot, "normal" build targets like "zImage" or "bzImage" are 5100not used. If you use recent kernel source, a new build target 5101"uImage" will exist which automatically builds an image usable by 5102U-Boot. Most older kernels also have support for a "pImage" target, 5103which was introduced for our predecessor project PPCBoot and uses a 5104100% compatible format. 5105 5106Example: 5107 5108 make TQM850L_defconfig 5109 make oldconfig 5110 make dep 5111 make uImage 5112 5113The "uImage" build target uses a special tool (in 'tools/mkimage') to 5114encapsulate a compressed Linux kernel image with header information, 5115CRC32 checksum etc. for use with U-Boot. This is what we are doing: 5116 5117* build a standard "vmlinux" kernel image (in ELF binary format): 5118 5119* convert the kernel into a raw binary image: 5120 5121 ${CROSS_COMPILE}-objcopy -O binary \ 5122 -R .note -R .comment \ 5123 -S vmlinux linux.bin 5124 5125* compress the binary image: 5126 5127 gzip -9 linux.bin 5128 5129* package compressed binary image for U-Boot: 5130 5131 mkimage -A ppc -O linux -T kernel -C gzip \ 5132 -a 0 -e 0 -n "Linux Kernel Image" \ 5133 -d linux.bin.gz uImage 5134 5135 5136The "mkimage" tool can also be used to create ramdisk images for use 5137with U-Boot, either separated from the Linux kernel image, or 5138combined into one file. "mkimage" encapsulates the images with a 64 5139byte header containing information about target architecture, 5140operating system, image type, compression method, entry points, time 5141stamp, CRC32 checksums, etc. 5142 5143"mkimage" can be called in two ways: to verify existing images and 5144print the header information, or to build new images. 5145 5146In the first form (with "-l" option) mkimage lists the information 5147contained in the header of an existing U-Boot image; this includes 5148checksum verification: 5149 5150 tools/mkimage -l image 5151 -l ==> list image header information 5152 5153The second form (with "-d" option) is used to build a U-Boot image 5154from a "data file" which is used as image payload: 5155 5156 tools/mkimage -A arch -O os -T type -C comp -a addr -e ep \ 5157 -n name -d data_file image 5158 -A ==> set architecture to 'arch' 5159 -O ==> set operating system to 'os' 5160 -T ==> set image type to 'type' 5161 -C ==> set compression type 'comp' 5162 -a ==> set load address to 'addr' (hex) 5163 -e ==> set entry point to 'ep' (hex) 5164 -n ==> set image name to 'name' 5165 -d ==> use image data from 'datafile' 5166 5167Right now, all Linux kernels for PowerPC systems use the same load 5168address (0x00000000), but the entry point address depends on the 5169kernel version: 5170 5171- 2.2.x kernels have the entry point at 0x0000000C, 5172- 2.3.x and later kernels have the entry point at 0x00000000. 5173 5174So a typical call to build a U-Boot image would read: 5175 5176 -> tools/mkimage -n '2.4.4 kernel for TQM850L' \ 5177 > -A ppc -O linux -T kernel -C gzip -a 0 -e 0 \ 5178 > -d /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/powerpc/coffboot/vmlinux.gz \ 5179 > examples/uImage.TQM850L 5180 Image Name: 2.4.4 kernel for TQM850L 5181 Created: Wed Jul 19 02:34:59 2000 5182 Image Type: PowerPC Linux Kernel Image (gzip compressed) 5183 Data Size: 335725 Bytes = 327.86 kB = 0.32 MB 5184 Load Address: 0x00000000 5185 Entry Point: 0x00000000 5186 5187To verify the contents of the image (or check for corruption): 5188 5189 -> tools/mkimage -l examples/uImage.TQM850L 5190 Image Name: 2.4.4 kernel for TQM850L 5191 Created: Wed Jul 19 02:34:59 2000 5192 Image Type: PowerPC Linux Kernel Image (gzip compressed) 5193 Data Size: 335725 Bytes = 327.86 kB = 0.32 MB 5194 Load Address: 0x00000000 5195 Entry Point: 0x00000000 5196 5197NOTE: for embedded systems where boot time is critical you can trade 5198speed for memory and install an UNCOMPRESSED image instead: this 5199needs more space in Flash, but boots much faster since it does not 5200need to be uncompressed: 5201 5202 -> gunzip /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/powerpc/coffboot/vmlinux.gz 5203 -> tools/mkimage -n '2.4.4 kernel for TQM850L' \ 5204 > -A ppc -O linux -T kernel -C none -a 0 -e 0 \ 5205 > -d /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/powerpc/coffboot/vmlinux \ 5206 > examples/uImage.TQM850L-uncompressed 5207 Image Name: 2.4.4 kernel for TQM850L 5208 Created: Wed Jul 19 02:34:59 2000 5209 Image Type: PowerPC Linux Kernel Image (uncompressed) 5210 Data Size: 792160 Bytes = 773.59 kB = 0.76 MB 5211 Load Address: 0x00000000 5212 Entry Point: 0x00000000 5213 5214 5215Similar you can build U-Boot images from a 'ramdisk.image.gz' file 5216when your kernel is intended to use an initial ramdisk: 5217 5218 -> tools/mkimage -n 'Simple Ramdisk Image' \ 5219 > -A ppc -O linux -T ramdisk -C gzip \ 5220 > -d /LinuxPPC/images/SIMPLE-ramdisk.image.gz examples/simple-initrd 5221 Image Name: Simple Ramdisk Image 5222 Created: Wed Jan 12 14:01:50 2000 5223 Image Type: PowerPC Linux RAMDisk Image (gzip compressed) 5224 Data Size: 566530 Bytes = 553.25 kB = 0.54 MB 5225 Load Address: 0x00000000 5226 Entry Point: 0x00000000 5227 5228The "dumpimage" is a tool to disassemble images built by mkimage. Its "-i" 5229option performs the converse operation of the mkimage's second form (the "-d" 5230option). Given an image built by mkimage, the dumpimage extracts a "data file" 5231from the image: 5232 5233 tools/dumpimage -i image -T type -p position data_file 5234 -i ==> extract from the 'image' a specific 'data_file' 5235 -T ==> set image type to 'type' 5236 -p ==> 'position' (starting at 0) of the 'data_file' inside the 'image' 5237 5238 5239Installing a Linux Image: 5240------------------------- 5241 5242To downloading a U-Boot image over the serial (console) interface, 5243you must convert the image to S-Record format: 5244 5245 objcopy -I binary -O srec examples/image examples/image.srec 5246 5247The 'objcopy' does not understand the information in the U-Boot 5248image header, so the resulting S-Record file will be relative to 5249address 0x00000000. To load it to a given address, you need to 5250specify the target address as 'offset' parameter with the 'loads' 5251command. 5252 5253Example: install the image to address 0x40100000 (which on the 5254TQM8xxL is in the first Flash bank): 5255 5256 => erase 40100000 401FFFFF 5257 5258 .......... done 5259 Erased 8 sectors 5260 5261 => loads 40100000 5262 ## Ready for S-Record download ... 5263 ~>examples/image.srec 5264 1 2 3 4 5 6 7 8 9 10 11 12 13 ... 5265 ... 5266 15989 15990 15991 15992 5267 [file transfer complete] 5268 [connected] 5269 ## Start Addr = 0x00000000 5270 5271 5272You can check the success of the download using the 'iminfo' command; 5273this includes a checksum verification so you can be sure no data 5274corruption happened: 5275 5276 => imi 40100000 5277 5278 ## Checking Image at 40100000 ... 5279 Image Name: 2.2.13 for initrd on TQM850L 5280 Image Type: PowerPC Linux Kernel Image (gzip compressed) 5281 Data Size: 335725 Bytes = 327 kB = 0 MB 5282 Load Address: 00000000 5283 Entry Point: 0000000c 5284 Verifying Checksum ... OK 5285 5286 5287Boot Linux: 5288----------- 5289 5290The "bootm" command is used to boot an application that is stored in 5291memory (RAM or Flash). In case of a Linux kernel image, the contents 5292of the "bootargs" environment variable is passed to the kernel as 5293parameters. You can check and modify this variable using the 5294"printenv" and "setenv" commands: 5295 5296 5297 => printenv bootargs 5298 bootargs=root=/dev/ram 5299 5300 => setenv bootargs root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2 5301 5302 => printenv bootargs 5303 bootargs=root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2 5304 5305 => bootm 40020000 5306 ## Booting Linux kernel at 40020000 ... 5307 Image Name: 2.2.13 for NFS on TQM850L 5308 Image Type: PowerPC Linux Kernel Image (gzip compressed) 5309 Data Size: 381681 Bytes = 372 kB = 0 MB 5310 Load Address: 00000000 5311 Entry Point: 0000000c 5312 Verifying Checksum ... OK 5313 Uncompressing Kernel Image ... OK 5314 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 5315 Boot arguments: root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2 5316 time_init: decrementer frequency = 187500000/60 5317 Calibrating delay loop... 49.77 BogoMIPS 5318 Memory: 15208k available (700k kernel code, 444k data, 32k init) [c0000000,c1000000] 5319 ... 5320 5321If you want to boot a Linux kernel with initial RAM disk, you pass 5322the memory addresses of both the kernel and the initrd image (PPBCOOT 5323format!) to the "bootm" command: 5324 5325 => imi 40100000 40200000 5326 5327 ## Checking Image at 40100000 ... 5328 Image Name: 2.2.13 for initrd on TQM850L 5329 Image Type: PowerPC Linux Kernel Image (gzip compressed) 5330 Data Size: 335725 Bytes = 327 kB = 0 MB 5331 Load Address: 00000000 5332 Entry Point: 0000000c 5333 Verifying Checksum ... OK 5334 5335 ## Checking Image at 40200000 ... 5336 Image Name: Simple Ramdisk Image 5337 Image Type: PowerPC Linux RAMDisk Image (gzip compressed) 5338 Data Size: 566530 Bytes = 553 kB = 0 MB 5339 Load Address: 00000000 5340 Entry Point: 00000000 5341 Verifying Checksum ... OK 5342 5343 => bootm 40100000 40200000 5344 ## Booting Linux kernel at 40100000 ... 5345 Image Name: 2.2.13 for initrd on TQM850L 5346 Image Type: PowerPC Linux Kernel Image (gzip compressed) 5347 Data Size: 335725 Bytes = 327 kB = 0 MB 5348 Load Address: 00000000 5349 Entry Point: 0000000c 5350 Verifying Checksum ... OK 5351 Uncompressing Kernel Image ... OK 5352 ## Loading RAMDisk Image at 40200000 ... 5353 Image Name: Simple Ramdisk Image 5354 Image Type: PowerPC Linux RAMDisk Image (gzip compressed) 5355 Data Size: 566530 Bytes = 553 kB = 0 MB 5356 Load Address: 00000000 5357 Entry Point: 00000000 5358 Verifying Checksum ... OK 5359 Loading Ramdisk ... OK 5360 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 5361 Boot arguments: root=/dev/ram 5362 time_init: decrementer frequency = 187500000/60 5363 Calibrating delay loop... 49.77 BogoMIPS 5364 ... 5365 RAMDISK: Compressed image found at block 0 5366 VFS: Mounted root (ext2 filesystem). 5367 5368 bash# 5369 5370Boot Linux and pass a flat device tree: 5371----------- 5372 5373First, U-Boot must be compiled with the appropriate defines. See the section 5374titled "Linux Kernel Interface" above for a more in depth explanation. The 5375following is an example of how to start a kernel and pass an updated 5376flat device tree: 5377 5378=> print oftaddr 5379oftaddr=0x300000 5380=> print oft 5381oft=oftrees/mpc8540ads.dtb 5382=> tftp $oftaddr $oft 5383Speed: 1000, full duplex 5384Using TSEC0 device 5385TFTP from server 192.168.1.1; our IP address is 192.168.1.101 5386Filename 'oftrees/mpc8540ads.dtb'. 5387Load address: 0x300000 5388Loading: # 5389done 5390Bytes transferred = 4106 (100a hex) 5391=> tftp $loadaddr $bootfile 5392Speed: 1000, full duplex 5393Using TSEC0 device 5394TFTP from server 192.168.1.1; our IP address is 192.168.1.2 5395Filename 'uImage'. 5396Load address: 0x200000 5397Loading:############ 5398done 5399Bytes transferred = 1029407 (fb51f hex) 5400=> print loadaddr 5401loadaddr=200000 5402=> print oftaddr 5403oftaddr=0x300000 5404=> bootm $loadaddr - $oftaddr 5405## Booting image at 00200000 ... 5406 Image Name: Linux-2.6.17-dirty 5407 Image Type: PowerPC Linux Kernel Image (gzip compressed) 5408 Data Size: 1029343 Bytes = 1005.2 kB 5409 Load Address: 00000000 5410 Entry Point: 00000000 5411 Verifying Checksum ... OK 5412 Uncompressing Kernel Image ... OK 5413Booting using flat device tree at 0x300000 5414Using MPC85xx ADS machine description 5415Memory CAM mapping: CAM0=256Mb, CAM1=256Mb, CAM2=0Mb residual: 0Mb 5416[snip] 5417 5418 5419More About U-Boot Image Types: 5420------------------------------ 5421 5422U-Boot supports the following image types: 5423 5424 "Standalone Programs" are directly runnable in the environment 5425 provided by U-Boot; it is expected that (if they behave 5426 well) you can continue to work in U-Boot after return from 5427 the Standalone Program. 5428 "OS Kernel Images" are usually images of some Embedded OS which 5429 will take over control completely. Usually these programs 5430 will install their own set of exception handlers, device 5431 drivers, set up the MMU, etc. - this means, that you cannot 5432 expect to re-enter U-Boot except by resetting the CPU. 5433 "RAMDisk Images" are more or less just data blocks, and their 5434 parameters (address, size) are passed to an OS kernel that is 5435 being started. 5436 "Multi-File Images" contain several images, typically an OS 5437 (Linux) kernel image and one or more data images like 5438 RAMDisks. This construct is useful for instance when you want 5439 to boot over the network using BOOTP etc., where the boot 5440 server provides just a single image file, but you want to get 5441 for instance an OS kernel and a RAMDisk image. 5442 5443 "Multi-File Images" start with a list of image sizes, each 5444 image size (in bytes) specified by an "uint32_t" in network 5445 byte order. This list is terminated by an "(uint32_t)0". 5446 Immediately after the terminating 0 follow the images, one by 5447 one, all aligned on "uint32_t" boundaries (size rounded up to 5448 a multiple of 4 bytes). 5449 5450 "Firmware Images" are binary images containing firmware (like 5451 U-Boot or FPGA images) which usually will be programmed to 5452 flash memory. 5453 5454 "Script files" are command sequences that will be executed by 5455 U-Boot's command interpreter; this feature is especially 5456 useful when you configure U-Boot to use a real shell (hush) 5457 as command interpreter. 5458 5459Booting the Linux zImage: 5460------------------------- 5461 5462On some platforms, it's possible to boot Linux zImage. This is done 5463using the "bootz" command. The syntax of "bootz" command is the same 5464as the syntax of "bootm" command. 5465 5466Note, defining the CONFIG_SUPPORT_RAW_INITRD allows user to supply 5467kernel with raw initrd images. The syntax is slightly different, the 5468address of the initrd must be augmented by it's size, in the following 5469format: "<initrd addres>:<initrd size>". 5470 5471 5472Standalone HOWTO: 5473================= 5474 5475One of the features of U-Boot is that you can dynamically load and 5476run "standalone" applications, which can use some resources of 5477U-Boot like console I/O functions or interrupt services. 5478 5479Two simple examples are included with the sources: 5480 5481"Hello World" Demo: 5482------------------- 5483 5484'examples/hello_world.c' contains a small "Hello World" Demo 5485application; it is automatically compiled when you build U-Boot. 5486It's configured to run at address 0x00040004, so you can play with it 5487like that: 5488 5489 => loads 5490 ## Ready for S-Record download ... 5491 ~>examples/hello_world.srec 5492 1 2 3 4 5 6 7 8 9 10 11 ... 5493 [file transfer complete] 5494 [connected] 5495 ## Start Addr = 0x00040004 5496 5497 => go 40004 Hello World! This is a test. 5498 ## Starting application at 0x00040004 ... 5499 Hello World 5500 argc = 7 5501 argv[0] = "40004" 5502 argv[1] = "Hello" 5503 argv[2] = "World!" 5504 argv[3] = "This" 5505 argv[4] = "is" 5506 argv[5] = "a" 5507 argv[6] = "test." 5508 argv[7] = "<NULL>" 5509 Hit any key to exit ... 5510 5511 ## Application terminated, rc = 0x0 5512 5513Another example, which demonstrates how to register a CPM interrupt 5514handler with the U-Boot code, can be found in 'examples/timer.c'. 5515Here, a CPM timer is set up to generate an interrupt every second. 5516The interrupt service routine is trivial, just printing a '.' 5517character, but this is just a demo program. The application can be 5518controlled by the following keys: 5519 5520 ? - print current values og the CPM Timer registers 5521 b - enable interrupts and start timer 5522 e - stop timer and disable interrupts 5523 q - quit application 5524 5525 => loads 5526 ## Ready for S-Record download ... 5527 ~>examples/timer.srec 5528 1 2 3 4 5 6 7 8 9 10 11 ... 5529 [file transfer complete] 5530 [connected] 5531 ## Start Addr = 0x00040004 5532 5533 => go 40004 5534 ## Starting application at 0x00040004 ... 5535 TIMERS=0xfff00980 5536 Using timer 1 5537 tgcr @ 0xfff00980, tmr @ 0xfff00990, trr @ 0xfff00994, tcr @ 0xfff00998, tcn @ 0xfff0099c, ter @ 0xfff009b0 5538 5539Hit 'b': 5540 [q, b, e, ?] Set interval 1000000 us 5541 Enabling timer 5542Hit '?': 5543 [q, b, e, ?] ........ 5544 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0xef6, ter=0x0 5545Hit '?': 5546 [q, b, e, ?] . 5547 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x2ad4, ter=0x0 5548Hit '?': 5549 [q, b, e, ?] . 5550 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x1efc, ter=0x0 5551Hit '?': 5552 [q, b, e, ?] . 5553 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x169d, ter=0x0 5554Hit 'e': 5555 [q, b, e, ?] ...Stopping timer 5556Hit 'q': 5557 [q, b, e, ?] ## Application terminated, rc = 0x0 5558 5559 5560Minicom warning: 5561================ 5562 5563Over time, many people have reported problems when trying to use the 5564"minicom" terminal emulation program for serial download. I (wd) 5565consider minicom to be broken, and recommend not to use it. Under 5566Unix, I recommend to use C-Kermit for general purpose use (and 5567especially for kermit binary protocol download ("loadb" command), and 5568use "cu" for S-Record download ("loads" command). See 5569http://www.denx.de/wiki/view/DULG/SystemSetup#Section_4.3. 5570for help with kermit. 5571 5572 5573Nevertheless, if you absolutely want to use it try adding this 5574configuration to your "File transfer protocols" section: 5575 5576 Name Program Name U/D FullScr IO-Red. Multi 5577 X kermit /usr/bin/kermit -i -l %l -s Y U Y N N 5578 Y kermit /usr/bin/kermit -i -l %l -r N D Y N N 5579 5580 5581NetBSD Notes: 5582============= 5583 5584Starting at version 0.9.2, U-Boot supports NetBSD both as host 5585(build U-Boot) and target system (boots NetBSD/mpc8xx). 5586 5587Building requires a cross environment; it is known to work on 5588NetBSD/i386 with the cross-powerpc-netbsd-1.3 package (you will also 5589need gmake since the Makefiles are not compatible with BSD make). 5590Note that the cross-powerpc package does not install include files; 5591attempting to build U-Boot will fail because <machine/ansi.h> is 5592missing. This file has to be installed and patched manually: 5593 5594 # cd /usr/pkg/cross/powerpc-netbsd/include 5595 # mkdir powerpc 5596 # ln -s powerpc machine 5597 # cp /usr/src/sys/arch/powerpc/include/ansi.h powerpc/ansi.h 5598 # ${EDIT} powerpc/ansi.h ## must remove __va_list, _BSD_VA_LIST 5599 5600Native builds *don't* work due to incompatibilities between native 5601and U-Boot include files. 5602 5603Booting assumes that (the first part of) the image booted is a 5604stage-2 loader which in turn loads and then invokes the kernel 5605proper. Loader sources will eventually appear in the NetBSD source 5606tree (probably in sys/arc/mpc8xx/stand/u-boot_stage2/); in the 5607meantime, see ftp://ftp.denx.de/pub/u-boot/ppcboot_stage2.tar.gz 5608 5609 5610Implementation Internals: 5611========================= 5612 5613The following is not intended to be a complete description of every 5614implementation detail. However, it should help to understand the 5615inner workings of U-Boot and make it easier to port it to custom 5616hardware. 5617 5618 5619Initial Stack, Global Data: 5620--------------------------- 5621 5622The implementation of U-Boot is complicated by the fact that U-Boot 5623starts running out of ROM (flash memory), usually without access to 5624system RAM (because the memory controller is not initialized yet). 5625This means that we don't have writable Data or BSS segments, and BSS 5626is not initialized as zero. To be able to get a C environment working 5627at all, we have to allocate at least a minimal stack. Implementation 5628options for this are defined and restricted by the CPU used: Some CPU 5629models provide on-chip memory (like the IMMR area on MPC8xx and 5630MPC826x processors), on others (parts of) the data cache can be 5631locked as (mis-) used as memory, etc. 5632 5633 Chris Hallinan posted a good summary of these issues to the 5634 U-Boot mailing list: 5635 5636 Subject: RE: [U-Boot-Users] RE: More On Memory Bank x (nothingness)? 5637 From: "Chris Hallinan" <clh@net1plus.com> 5638 Date: Mon, 10 Feb 2003 16:43:46 -0500 (22:43 MET) 5639 ... 5640 5641 Correct me if I'm wrong, folks, but the way I understand it 5642 is this: Using DCACHE as initial RAM for Stack, etc, does not 5643 require any physical RAM backing up the cache. The cleverness 5644 is that the cache is being used as a temporary supply of 5645 necessary storage before the SDRAM controller is setup. It's 5646 beyond the scope of this list to explain the details, but you 5647 can see how this works by studying the cache architecture and 5648 operation in the architecture and processor-specific manuals. 5649 5650 OCM is On Chip Memory, which I believe the 405GP has 4K. It 5651 is another option for the system designer to use as an 5652 initial stack/RAM area prior to SDRAM being available. Either 5653 option should work for you. Using CS 4 should be fine if your 5654 board designers haven't used it for something that would 5655 cause you grief during the initial boot! It is frequently not 5656 used. 5657 5658 CONFIG_SYS_INIT_RAM_ADDR should be somewhere that won't interfere 5659 with your processor/board/system design. The default value 5660 you will find in any recent u-boot distribution in 5661 walnut.h should work for you. I'd set it to a value larger 5662 than your SDRAM module. If you have a 64MB SDRAM module, set 5663 it above 400_0000. Just make sure your board has no resources 5664 that are supposed to respond to that address! That code in 5665 start.S has been around a while and should work as is when 5666 you get the config right. 5667 5668 -Chris Hallinan 5669 DS4.COM, Inc. 5670 5671It is essential to remember this, since it has some impact on the C 5672code for the initialization procedures: 5673 5674* Initialized global data (data segment) is read-only. Do not attempt 5675 to write it. 5676 5677* Do not use any uninitialized global data (or implicitly initialized 5678 as zero data - BSS segment) at all - this is undefined, initiali- 5679 zation is performed later (when relocating to RAM). 5680 5681* Stack space is very limited. Avoid big data buffers or things like 5682 that. 5683 5684Having only the stack as writable memory limits means we cannot use 5685normal global data to share information between the code. But it 5686turned out that the implementation of U-Boot can be greatly 5687simplified by making a global data structure (gd_t) available to all 5688functions. We could pass a pointer to this data as argument to _all_ 5689functions, but this would bloat the code. Instead we use a feature of 5690the GCC compiler (Global Register Variables) to share the data: we 5691place a pointer (gd) to the global data into a register which we 5692reserve for this purpose. 5693 5694When choosing a register for such a purpose we are restricted by the 5695relevant (E)ABI specifications for the current architecture, and by 5696GCC's implementation. 5697 5698For PowerPC, the following registers have specific use: 5699 R1: stack pointer 5700 R2: reserved for system use 5701 R3-R4: parameter passing and return values 5702 R5-R10: parameter passing 5703 R13: small data area pointer 5704 R30: GOT pointer 5705 R31: frame pointer 5706 5707 (U-Boot also uses R12 as internal GOT pointer. r12 5708 is a volatile register so r12 needs to be reset when 5709 going back and forth between asm and C) 5710 5711 ==> U-Boot will use R2 to hold a pointer to the global data 5712 5713 Note: on PPC, we could use a static initializer (since the 5714 address of the global data structure is known at compile time), 5715 but it turned out that reserving a register results in somewhat 5716 smaller code - although the code savings are not that big (on 5717 average for all boards 752 bytes for the whole U-Boot image, 5718 624 text + 127 data). 5719 5720On ARM, the following registers are used: 5721 5722 R0: function argument word/integer result 5723 R1-R3: function argument word 5724 R9: platform specific 5725 R10: stack limit (used only if stack checking is enabled) 5726 R11: argument (frame) pointer 5727 R12: temporary workspace 5728 R13: stack pointer 5729 R14: link register 5730 R15: program counter 5731 5732 ==> U-Boot will use R9 to hold a pointer to the global data 5733 5734 Note: on ARM, only R_ARM_RELATIVE relocations are supported. 5735 5736On Nios II, the ABI is documented here: 5737 http://www.altera.com/literature/hb/nios2/n2cpu_nii51016.pdf 5738 5739 ==> U-Boot will use gp to hold a pointer to the global data 5740 5741 Note: on Nios II, we give "-G0" option to gcc and don't use gp 5742 to access small data sections, so gp is free. 5743 5744On NDS32, the following registers are used: 5745 5746 R0-R1: argument/return 5747 R2-R5: argument 5748 R15: temporary register for assembler 5749 R16: trampoline register 5750 R28: frame pointer (FP) 5751 R29: global pointer (GP) 5752 R30: link register (LP) 5753 R31: stack pointer (SP) 5754 PC: program counter (PC) 5755 5756 ==> U-Boot will use R10 to hold a pointer to the global data 5757 5758NOTE: DECLARE_GLOBAL_DATA_PTR must be used with file-global scope, 5759or current versions of GCC may "optimize" the code too much. 5760 5761Memory Management: 5762------------------ 5763 5764U-Boot runs in system state and uses physical addresses, i.e. the 5765MMU is not used either for address mapping nor for memory protection. 5766 5767The available memory is mapped to fixed addresses using the memory 5768controller. In this process, a contiguous block is formed for each 5769memory type (Flash, SDRAM, SRAM), even when it consists of several 5770physical memory banks. 5771 5772U-Boot is installed in the first 128 kB of the first Flash bank (on 5773TQM8xxL modules this is the range 0x40000000 ... 0x4001FFFF). After 5774booting and sizing and initializing DRAM, the code relocates itself 5775to the upper end of DRAM. Immediately below the U-Boot code some 5776memory is reserved for use by malloc() [see CONFIG_SYS_MALLOC_LEN 5777configuration setting]. Below that, a structure with global Board 5778Info data is placed, followed by the stack (growing downward). 5779 5780Additionally, some exception handler code is copied to the low 8 kB 5781of DRAM (0x00000000 ... 0x00001FFF). 5782 5783So a typical memory configuration with 16 MB of DRAM could look like 5784this: 5785 5786 0x0000 0000 Exception Vector code 5787 : 5788 0x0000 1FFF 5789 0x0000 2000 Free for Application Use 5790 : 5791 : 5792 5793 : 5794 : 5795 0x00FB FF20 Monitor Stack (Growing downward) 5796 0x00FB FFAC Board Info Data and permanent copy of global data 5797 0x00FC 0000 Malloc Arena 5798 : 5799 0x00FD FFFF 5800 0x00FE 0000 RAM Copy of Monitor Code 5801 ... eventually: LCD or video framebuffer 5802 ... eventually: pRAM (Protected RAM - unchanged by reset) 5803 0x00FF FFFF [End of RAM] 5804 5805 5806System Initialization: 5807---------------------- 5808 5809In the reset configuration, U-Boot starts at the reset entry point 5810(on most PowerPC systems at address 0x00000100). Because of the reset 5811configuration for CS0# this is a mirror of the on board Flash memory. 5812To be able to re-map memory U-Boot then jumps to its link address. 5813To be able to implement the initialization code in C, a (small!) 5814initial stack is set up in the internal Dual Ported RAM (in case CPUs 5815which provide such a feature like MPC8xx or MPC8260), or in a locked 5816part of the data cache. After that, U-Boot initializes the CPU core, 5817the caches and the SIU. 5818 5819Next, all (potentially) available memory banks are mapped using a 5820preliminary mapping. For example, we put them on 512 MB boundaries 5821(multiples of 0x20000000: SDRAM on 0x00000000 and 0x20000000, Flash 5822on 0x40000000 and 0x60000000, SRAM on 0x80000000). Then UPM A is 5823programmed for SDRAM access. Using the temporary configuration, a 5824simple memory test is run that determines the size of the SDRAM 5825banks. 5826 5827When there is more than one SDRAM bank, and the banks are of 5828different size, the largest is mapped first. For equal size, the first 5829bank (CS2#) is mapped first. The first mapping is always for address 58300x00000000, with any additional banks following immediately to create 5831contiguous memory starting from 0. 5832 5833Then, the monitor installs itself at the upper end of the SDRAM area 5834and allocates memory for use by malloc() and for the global Board 5835Info data; also, the exception vector code is copied to the low RAM 5836pages, and the final stack is set up. 5837 5838Only after this relocation will you have a "normal" C environment; 5839until that you are restricted in several ways, mostly because you are 5840running from ROM, and because the code will have to be relocated to a 5841new address in RAM. 5842 5843 5844U-Boot Porting Guide: 5845---------------------- 5846 5847[Based on messages by Jerry Van Baren in the U-Boot-Users mailing 5848list, October 2002] 5849 5850 5851int main(int argc, char *argv[]) 5852{ 5853 sighandler_t no_more_time; 5854 5855 signal(SIGALRM, no_more_time); 5856 alarm(PROJECT_DEADLINE - toSec (3 * WEEK)); 5857 5858 if (available_money > available_manpower) { 5859 Pay consultant to port U-Boot; 5860 return 0; 5861 } 5862 5863 Download latest U-Boot source; 5864 5865 Subscribe to u-boot mailing list; 5866 5867 if (clueless) 5868 email("Hi, I am new to U-Boot, how do I get started?"); 5869 5870 while (learning) { 5871 Read the README file in the top level directory; 5872 Read http://www.denx.de/twiki/bin/view/DULG/Manual; 5873 Read applicable doc/*.README; 5874 Read the source, Luke; 5875 /* find . -name "*.[chS]" | xargs grep -i <keyword> */ 5876 } 5877 5878 if (available_money > toLocalCurrency ($2500)) 5879 Buy a BDI3000; 5880 else 5881 Add a lot of aggravation and time; 5882 5883 if (a similar board exists) { /* hopefully... */ 5884 cp -a board/<similar> board/<myboard> 5885 cp include/configs/<similar>.h include/configs/<myboard>.h 5886 } else { 5887 Create your own board support subdirectory; 5888 Create your own board include/configs/<myboard>.h file; 5889 } 5890 Edit new board/<myboard> files 5891 Edit new include/configs/<myboard>.h 5892 5893 while (!accepted) { 5894 while (!running) { 5895 do { 5896 Add / modify source code; 5897 } until (compiles); 5898 Debug; 5899 if (clueless) 5900 email("Hi, I am having problems..."); 5901 } 5902 Send patch file to the U-Boot email list; 5903 if (reasonable critiques) 5904 Incorporate improvements from email list code review; 5905 else 5906 Defend code as written; 5907 } 5908 5909 return 0; 5910} 5911 5912void no_more_time (int sig) 5913{ 5914 hire_a_guru(); 5915} 5916 5917 5918Coding Standards: 5919----------------- 5920 5921All contributions to U-Boot should conform to the Linux kernel 5922coding style; see the file "Documentation/CodingStyle" and the script 5923"scripts/Lindent" in your Linux kernel source directory. 5924 5925Source files originating from a different project (for example the 5926MTD subsystem) are generally exempt from these guidelines and are not 5927reformatted to ease subsequent migration to newer versions of those 5928sources. 5929 5930Please note that U-Boot is implemented in C (and to some small parts in 5931Assembler); no C++ is used, so please do not use C++ style comments (//) 5932in your code. 5933 5934Please also stick to the following formatting rules: 5935- remove any trailing white space 5936- use TAB characters for indentation and vertical alignment, not spaces 5937- make sure NOT to use DOS '\r\n' line feeds 5938- do not add more than 2 consecutive empty lines to source files 5939- do not add trailing empty lines to source files 5940 5941Submissions which do not conform to the standards may be returned 5942with a request to reformat the changes. 5943 5944 5945Submitting Patches: 5946------------------- 5947 5948Since the number of patches for U-Boot is growing, we need to 5949establish some rules. Submissions which do not conform to these rules 5950may be rejected, even when they contain important and valuable stuff. 5951 5952Please see http://www.denx.de/wiki/U-Boot/Patches for details. 5953 5954Patches shall be sent to the u-boot mailing list <u-boot@lists.denx.de>; 5955see http://lists.denx.de/mailman/listinfo/u-boot 5956 5957When you send a patch, please include the following information with 5958it: 5959 5960* For bug fixes: a description of the bug and how your patch fixes 5961 this bug. Please try to include a way of demonstrating that the 5962 patch actually fixes something. 5963 5964* For new features: a description of the feature and your 5965 implementation. 5966 5967* A CHANGELOG entry as plaintext (separate from the patch) 5968 5969* For major contributions, add a MAINTAINERS file with your 5970 information and associated file and directory references. 5971 5972* When you add support for a new board, don't forget to add a 5973 maintainer e-mail address to the boards.cfg file, too. 5974 5975* If your patch adds new configuration options, don't forget to 5976 document these in the README file. 5977 5978* The patch itself. If you are using git (which is *strongly* 5979 recommended) you can easily generate the patch using the 5980 "git format-patch". If you then use "git send-email" to send it to 5981 the U-Boot mailing list, you will avoid most of the common problems 5982 with some other mail clients. 5983 5984 If you cannot use git, use "diff -purN OLD NEW". If your version of 5985 diff does not support these options, then get the latest version of 5986 GNU diff. 5987 5988 The current directory when running this command shall be the parent 5989 directory of the U-Boot source tree (i. e. please make sure that 5990 your patch includes sufficient directory information for the 5991 affected files). 5992 5993 We prefer patches as plain text. MIME attachments are discouraged, 5994 and compressed attachments must not be used. 5995 5996* If one logical set of modifications affects or creates several 5997 files, all these changes shall be submitted in a SINGLE patch file. 5998 5999* Changesets that contain different, unrelated modifications shall be 6000 submitted as SEPARATE patches, one patch per changeset. 6001 6002 6003Notes: 6004 6005* Before sending the patch, run the buildman script on your patched 6006 source tree and make sure that no errors or warnings are reported 6007 for any of the boards. 6008 6009* Keep your modifications to the necessary minimum: A patch 6010 containing several unrelated changes or arbitrary reformats will be 6011 returned with a request to re-formatting / split it. 6012 6013* If you modify existing code, make sure that your new code does not 6014 add to the memory footprint of the code ;-) Small is beautiful! 6015 When adding new features, these should compile conditionally only 6016 (using #ifdef), and the resulting code with the new feature 6017 disabled must not need more memory than the old code without your 6018 modification. 6019 6020* Remember that there is a size limit of 100 kB per message on the 6021 u-boot mailing list. Bigger patches will be moderated. If they are 6022 reasonable and not too big, they will be acknowledged. But patches 6023 bigger than the size limit should be avoided. 6024