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_HASH * calculate hash / digest 850 CONFIG_CMD_I2C * I2C serial bus support 851 CONFIG_CMD_IDE * IDE harddisk support 852 CONFIG_CMD_IMI iminfo 853 CONFIG_CMD_IMLS List all images found in NOR flash 854 CONFIG_CMD_IMLS_NAND * List all images found in NAND flash 855 CONFIG_CMD_IMMAP * IMMR dump support 856 CONFIG_CMD_IOTRACE * I/O tracing for debugging 857 CONFIG_CMD_IMPORTENV * import an environment 858 CONFIG_CMD_INI * import data from an ini file into the env 859 CONFIG_CMD_IRQ * irqinfo 860 CONFIG_CMD_ITEST Integer/string test of 2 values 861 CONFIG_CMD_JFFS2 * JFFS2 Support 862 CONFIG_CMD_KGDB * kgdb 863 CONFIG_CMD_LDRINFO * ldrinfo (display Blackfin loader) 864 CONFIG_CMD_LINK_LOCAL * link-local IP address auto-configuration 865 (169.254.*.*) 866 CONFIG_CMD_LOADB loadb 867 CONFIG_CMD_LOADS loads 868 CONFIG_CMD_MD5SUM * print md5 message digest 869 (requires CONFIG_CMD_MEMORY and CONFIG_MD5) 870 CONFIG_CMD_MEMINFO * Display detailed memory information 871 CONFIG_CMD_MEMORY md, mm, nm, mw, cp, cmp, crc, base, 872 loop, loopw 873 CONFIG_CMD_MEMTEST * mtest 874 CONFIG_CMD_MISC Misc functions like sleep etc 875 CONFIG_CMD_MMC * MMC memory mapped support 876 CONFIG_CMD_MII * MII utility commands 877 CONFIG_CMD_MTDPARTS * MTD partition support 878 CONFIG_CMD_NAND * NAND support 879 CONFIG_CMD_NET bootp, tftpboot, rarpboot 880 CONFIG_CMD_NFS NFS support 881 CONFIG_CMD_PCA953X * PCA953x I2C gpio commands 882 CONFIG_CMD_PCA953X_INFO * PCA953x I2C gpio info command 883 CONFIG_CMD_PCI * pciinfo 884 CONFIG_CMD_PCMCIA * PCMCIA support 885 CONFIG_CMD_PING * send ICMP ECHO_REQUEST to network 886 host 887 CONFIG_CMD_PORTIO * Port I/O 888 CONFIG_CMD_READ * Read raw data from partition 889 CONFIG_CMD_REGINFO * Register dump 890 CONFIG_CMD_RUN run command in env variable 891 CONFIG_CMD_SANDBOX * sb command to access sandbox features 892 CONFIG_CMD_SAVES * save S record dump 893 CONFIG_SCSI * SCSI Support 894 CONFIG_CMD_SDRAM * print SDRAM configuration information 895 (requires CONFIG_CMD_I2C) 896 CONFIG_CMD_SETGETDCR Support for DCR Register access 897 (4xx only) 898 CONFIG_CMD_SF * Read/write/erase SPI NOR flash 899 CONFIG_CMD_SHA1SUM * print sha1 memory digest 900 (requires CONFIG_CMD_MEMORY) 901 CONFIG_CMD_SOFTSWITCH * Soft switch setting command for BF60x 902 CONFIG_CMD_SOURCE "source" command Support 903 CONFIG_CMD_SPI * SPI serial bus support 904 CONFIG_CMD_TFTPSRV * TFTP transfer in server mode 905 CONFIG_CMD_TFTPPUT * TFTP put command (upload) 906 CONFIG_CMD_TIME * run command and report execution time (ARM specific) 907 CONFIG_CMD_TIMER * access to the system tick timer 908 CONFIG_CMD_USB * USB support 909 CONFIG_CMD_CDP * Cisco Discover Protocol support 910 CONFIG_CMD_MFSL * Microblaze FSL support 911 CONFIG_CMD_XIMG Load part of Multi Image 912 CONFIG_CMD_UUID * Generate random UUID or GUID string 913 914 EXAMPLE: If you want all functions except of network 915 support you can write: 916 917 #include "config_cmd_all.h" 918 #undef CONFIG_CMD_NET 919 920 Other Commands: 921 fdt (flattened device tree) command: CONFIG_OF_LIBFDT 922 923 Note: Don't enable the "icache" and "dcache" commands 924 (configuration option CONFIG_CMD_CACHE) unless you know 925 what you (and your U-Boot users) are doing. Data 926 cache cannot be enabled on systems like the 8xx or 927 8260 (where accesses to the IMMR region must be 928 uncached), and it cannot be disabled on all other 929 systems where we (mis-) use the data cache to hold an 930 initial stack and some data. 931 932 933 XXX - this list needs to get updated! 934 935- Removal of commands 936 If no commands are needed to boot, you can disable 937 CONFIG_CMDLINE to remove them. In this case, the command line 938 will not be available, and when U-Boot wants to execute the 939 boot command (on start-up) it will call board_run_command() 940 instead. This can reduce image size significantly for very 941 simple boot procedures. 942 943- Regular expression support: 944 CONFIG_REGEX 945 If this variable is defined, U-Boot is linked against 946 the SLRE (Super Light Regular Expression) library, 947 which adds regex support to some commands, as for 948 example "env grep" and "setexpr". 949 950- Device tree: 951 CONFIG_OF_CONTROL 952 If this variable is defined, U-Boot will use a device tree 953 to configure its devices, instead of relying on statically 954 compiled #defines in the board file. This option is 955 experimental and only available on a few boards. The device 956 tree is available in the global data as gd->fdt_blob. 957 958 U-Boot needs to get its device tree from somewhere. This can 959 be done using one of the three options below: 960 961 CONFIG_OF_EMBED 962 If this variable is defined, U-Boot will embed a device tree 963 binary in its image. This device tree file should be in the 964 board directory and called <soc>-<board>.dts. The binary file 965 is then picked up in board_init_f() and made available through 966 the global data structure as gd->blob. 967 968 CONFIG_OF_SEPARATE 969 If this variable is defined, U-Boot will build a device tree 970 binary. It will be called u-boot.dtb. Architecture-specific 971 code will locate it at run-time. Generally this works by: 972 973 cat u-boot.bin u-boot.dtb >image.bin 974 975 and in fact, U-Boot does this for you, creating a file called 976 u-boot-dtb.bin which is useful in the common case. You can 977 still use the individual files if you need something more 978 exotic. 979 980 CONFIG_OF_BOARD 981 If this variable is defined, U-Boot will use the device tree 982 provided by the board at runtime instead of embedding one with 983 the image. Only boards defining board_fdt_blob_setup() support 984 this option (see include/fdtdec.h file). 985 986- Watchdog: 987 CONFIG_WATCHDOG 988 If this variable is defined, it enables watchdog 989 support for the SoC. There must be support in the SoC 990 specific code for a watchdog. For the 8xx and 8260 991 CPUs, the SIU Watchdog feature is enabled in the SYPCR 992 register. When supported for a specific SoC is 993 available, then no further board specific code should 994 be needed to use it. 995 996 CONFIG_HW_WATCHDOG 997 When using a watchdog circuitry external to the used 998 SoC, then define this variable and provide board 999 specific code for the "hw_watchdog_reset" function. 1000 1001 CONFIG_AT91_HW_WDT_TIMEOUT 1002 specify the timeout in seconds. default 2 seconds. 1003 1004- U-Boot Version: 1005 CONFIG_VERSION_VARIABLE 1006 If this variable is defined, an environment variable 1007 named "ver" is created by U-Boot showing the U-Boot 1008 version as printed by the "version" command. 1009 Any change to this variable will be reverted at the 1010 next reset. 1011 1012- Real-Time Clock: 1013 1014 When CONFIG_CMD_DATE is selected, the type of the RTC 1015 has to be selected, too. Define exactly one of the 1016 following options: 1017 1018 CONFIG_RTC_MPC8xx - use internal RTC of MPC8xx 1019 CONFIG_RTC_PCF8563 - use Philips PCF8563 RTC 1020 CONFIG_RTC_MC13XXX - use MC13783 or MC13892 RTC 1021 CONFIG_RTC_MC146818 - use MC146818 RTC 1022 CONFIG_RTC_DS1307 - use Maxim, Inc. DS1307 RTC 1023 CONFIG_RTC_DS1337 - use Maxim, Inc. DS1337 RTC 1024 CONFIG_RTC_DS1338 - use Maxim, Inc. DS1338 RTC 1025 CONFIG_RTC_DS1339 - use Maxim, Inc. DS1339 RTC 1026 CONFIG_RTC_DS164x - use Dallas DS164x RTC 1027 CONFIG_RTC_ISL1208 - use Intersil ISL1208 RTC 1028 CONFIG_RTC_MAX6900 - use Maxim, Inc. MAX6900 RTC 1029 CONFIG_SYS_RTC_DS1337_NOOSC - Turn off the OSC output for DS1337 1030 CONFIG_SYS_RV3029_TCR - enable trickle charger on 1031 RV3029 RTC. 1032 1033 Note that if the RTC uses I2C, then the I2C interface 1034 must also be configured. See I2C Support, below. 1035 1036- GPIO Support: 1037 CONFIG_PCA953X - use NXP's PCA953X series I2C GPIO 1038 1039 The CONFIG_SYS_I2C_PCA953X_WIDTH option specifies a list of 1040 chip-ngpio pairs that tell the PCA953X driver the number of 1041 pins supported by a particular chip. 1042 1043 Note that if the GPIO device uses I2C, then the I2C interface 1044 must also be configured. See I2C Support, below. 1045 1046- I/O tracing: 1047 When CONFIG_IO_TRACE is selected, U-Boot intercepts all I/O 1048 accesses and can checksum them or write a list of them out 1049 to memory. See the 'iotrace' command for details. This is 1050 useful for testing device drivers since it can confirm that 1051 the driver behaves the same way before and after a code 1052 change. Currently this is supported on sandbox and arm. To 1053 add support for your architecture, add '#include <iotrace.h>' 1054 to the bottom of arch/<arch>/include/asm/io.h and test. 1055 1056 Example output from the 'iotrace stats' command is below. 1057 Note that if the trace buffer is exhausted, the checksum will 1058 still continue to operate. 1059 1060 iotrace is enabled 1061 Start: 10000000 (buffer start address) 1062 Size: 00010000 (buffer size) 1063 Offset: 00000120 (current buffer offset) 1064 Output: 10000120 (start + offset) 1065 Count: 00000018 (number of trace records) 1066 CRC32: 9526fb66 (CRC32 of all trace records) 1067 1068- Timestamp Support: 1069 1070 When CONFIG_TIMESTAMP is selected, the timestamp 1071 (date and time) of an image is printed by image 1072 commands like bootm or iminfo. This option is 1073 automatically enabled when you select CONFIG_CMD_DATE . 1074 1075- Partition Labels (disklabels) Supported: 1076 Zero or more of the following: 1077 CONFIG_MAC_PARTITION Apple's MacOS partition table. 1078 CONFIG_DOS_PARTITION MS Dos partition table, traditional on the 1079 Intel architecture, USB sticks, etc. 1080 CONFIG_ISO_PARTITION ISO partition table, used on CDROM etc. 1081 CONFIG_EFI_PARTITION GPT partition table, common when EFI is the 1082 bootloader. Note 2TB partition limit; see 1083 disk/part_efi.c 1084 CONFIG_MTD_PARTITIONS Memory Technology Device partition table. 1085 1086 If IDE or SCSI support is enabled (CONFIG_CMD_IDE or 1087 CONFIG_SCSI) you must configure support for at 1088 least one non-MTD partition type as well. 1089 1090- IDE Reset method: 1091 CONFIG_IDE_RESET_ROUTINE - this is defined in several 1092 board configurations files but used nowhere! 1093 1094 CONFIG_IDE_RESET - is this is defined, IDE Reset will 1095 be performed by calling the function 1096 ide_set_reset(int reset) 1097 which has to be defined in a board specific file 1098 1099- ATAPI Support: 1100 CONFIG_ATAPI 1101 1102 Set this to enable ATAPI support. 1103 1104- LBA48 Support 1105 CONFIG_LBA48 1106 1107 Set this to enable support for disks larger than 137GB 1108 Also look at CONFIG_SYS_64BIT_LBA. 1109 Whithout these , LBA48 support uses 32bit variables and will 'only' 1110 support disks up to 2.1TB. 1111 1112 CONFIG_SYS_64BIT_LBA: 1113 When enabled, makes the IDE subsystem use 64bit sector addresses. 1114 Default is 32bit. 1115 1116- SCSI Support: 1117 At the moment only there is only support for the 1118 SYM53C8XX SCSI controller; define 1119 CONFIG_SCSI_SYM53C8XX to enable it. 1120 1121 CONFIG_SYS_SCSI_MAX_LUN [8], CONFIG_SYS_SCSI_MAX_SCSI_ID [7] and 1122 CONFIG_SYS_SCSI_MAX_DEVICE [CONFIG_SYS_SCSI_MAX_SCSI_ID * 1123 CONFIG_SYS_SCSI_MAX_LUN] can be adjusted to define the 1124 maximum numbers of LUNs, SCSI ID's and target 1125 devices. 1126 CONFIG_SYS_SCSI_SYM53C8XX_CCF to fix clock timing (80Mhz) 1127 1128 The environment variable 'scsidevs' is set to the number of 1129 SCSI devices found during the last scan. 1130 1131- NETWORK Support (PCI): 1132 CONFIG_E1000 1133 Support for Intel 8254x/8257x gigabit chips. 1134 1135 CONFIG_E1000_SPI 1136 Utility code for direct access to the SPI bus on Intel 8257x. 1137 This does not do anything useful unless you set at least one 1138 of CONFIG_CMD_E1000 or CONFIG_E1000_SPI_GENERIC. 1139 1140 CONFIG_E1000_SPI_GENERIC 1141 Allow generic access to the SPI bus on the Intel 8257x, for 1142 example with the "sspi" command. 1143 1144 CONFIG_CMD_E1000 1145 Management command for E1000 devices. When used on devices 1146 with SPI support you can reprogram the EEPROM from U-Boot. 1147 1148 CONFIG_EEPRO100 1149 Support for Intel 82557/82559/82559ER chips. 1150 Optional CONFIG_EEPRO100_SROM_WRITE enables EEPROM 1151 write routine for first time initialisation. 1152 1153 CONFIG_TULIP 1154 Support for Digital 2114x chips. 1155 Optional CONFIG_TULIP_SELECT_MEDIA for board specific 1156 modem chip initialisation (KS8761/QS6611). 1157 1158 CONFIG_NATSEMI 1159 Support for National dp83815 chips. 1160 1161 CONFIG_NS8382X 1162 Support for National dp8382[01] gigabit chips. 1163 1164- NETWORK Support (other): 1165 1166 CONFIG_DRIVER_AT91EMAC 1167 Support for AT91RM9200 EMAC. 1168 1169 CONFIG_RMII 1170 Define this to use reduced MII inteface 1171 1172 CONFIG_DRIVER_AT91EMAC_QUIET 1173 If this defined, the driver is quiet. 1174 The driver doen't show link status messages. 1175 1176 CONFIG_CALXEDA_XGMAC 1177 Support for the Calxeda XGMAC device 1178 1179 CONFIG_LAN91C96 1180 Support for SMSC's LAN91C96 chips. 1181 1182 CONFIG_LAN91C96_USE_32_BIT 1183 Define this to enable 32 bit addressing 1184 1185 CONFIG_SMC91111 1186 Support for SMSC's LAN91C111 chip 1187 1188 CONFIG_SMC91111_BASE 1189 Define this to hold the physical address 1190 of the device (I/O space) 1191 1192 CONFIG_SMC_USE_32_BIT 1193 Define this if data bus is 32 bits 1194 1195 CONFIG_SMC_USE_IOFUNCS 1196 Define this to use i/o functions instead of macros 1197 (some hardware wont work with macros) 1198 1199 CONFIG_DRIVER_TI_EMAC 1200 Support for davinci emac 1201 1202 CONFIG_SYS_DAVINCI_EMAC_PHY_COUNT 1203 Define this if you have more then 3 PHYs. 1204 1205 CONFIG_FTGMAC100 1206 Support for Faraday's FTGMAC100 Gigabit SoC Ethernet 1207 1208 CONFIG_FTGMAC100_EGIGA 1209 Define this to use GE link update with gigabit PHY. 1210 Define this if FTGMAC100 is connected to gigabit PHY. 1211 If your system has 10/100 PHY only, it might not occur 1212 wrong behavior. Because PHY usually return timeout or 1213 useless data when polling gigabit status and gigabit 1214 control registers. This behavior won't affect the 1215 correctnessof 10/100 link speed update. 1216 1217 CONFIG_SMC911X 1218 Support for SMSC's LAN911x and LAN921x chips 1219 1220 CONFIG_SMC911X_BASE 1221 Define this to hold the physical address 1222 of the device (I/O space) 1223 1224 CONFIG_SMC911X_32_BIT 1225 Define this if data bus is 32 bits 1226 1227 CONFIG_SMC911X_16_BIT 1228 Define this if data bus is 16 bits. If your processor 1229 automatically converts one 32 bit word to two 16 bit 1230 words you may also try CONFIG_SMC911X_32_BIT. 1231 1232 CONFIG_SH_ETHER 1233 Support for Renesas on-chip Ethernet controller 1234 1235 CONFIG_SH_ETHER_USE_PORT 1236 Define the number of ports to be used 1237 1238 CONFIG_SH_ETHER_PHY_ADDR 1239 Define the ETH PHY's address 1240 1241 CONFIG_SH_ETHER_CACHE_WRITEBACK 1242 If this option is set, the driver enables cache flush. 1243 1244- PWM Support: 1245 CONFIG_PWM_IMX 1246 Support for PWM module on the imx6. 1247 1248- TPM Support: 1249 CONFIG_TPM 1250 Support TPM devices. 1251 1252 CONFIG_TPM_TIS_INFINEON 1253 Support for Infineon i2c bus TPM devices. Only one device 1254 per system is supported at this time. 1255 1256 CONFIG_TPM_TIS_I2C_BURST_LIMITATION 1257 Define the burst count bytes upper limit 1258 1259 CONFIG_TPM_ST33ZP24 1260 Support for STMicroelectronics TPM devices. Requires DM_TPM support. 1261 1262 CONFIG_TPM_ST33ZP24_I2C 1263 Support for STMicroelectronics ST33ZP24 I2C devices. 1264 Requires TPM_ST33ZP24 and I2C. 1265 1266 CONFIG_TPM_ST33ZP24_SPI 1267 Support for STMicroelectronics ST33ZP24 SPI devices. 1268 Requires TPM_ST33ZP24 and SPI. 1269 1270 CONFIG_TPM_ATMEL_TWI 1271 Support for Atmel TWI TPM device. Requires I2C support. 1272 1273 CONFIG_TPM_TIS_LPC 1274 Support for generic parallel port TPM devices. Only one device 1275 per system is supported at this time. 1276 1277 CONFIG_TPM_TIS_BASE_ADDRESS 1278 Base address where the generic TPM device is mapped 1279 to. Contemporary x86 systems usually map it at 1280 0xfed40000. 1281 1282 CONFIG_CMD_TPM 1283 Add tpm monitor functions. 1284 Requires CONFIG_TPM. If CONFIG_TPM_AUTH_SESSIONS is set, also 1285 provides monitor access to authorized functions. 1286 1287 CONFIG_TPM 1288 Define this to enable the TPM support library which provides 1289 functional interfaces to some TPM commands. 1290 Requires support for a TPM device. 1291 1292 CONFIG_TPM_AUTH_SESSIONS 1293 Define this to enable authorized functions in the TPM library. 1294 Requires CONFIG_TPM and CONFIG_SHA1. 1295 1296- USB Support: 1297 At the moment only the UHCI host controller is 1298 supported (PIP405, MIP405, MPC5200); define 1299 CONFIG_USB_UHCI to enable it. 1300 define CONFIG_USB_KEYBOARD to enable the USB Keyboard 1301 and define CONFIG_USB_STORAGE to enable the USB 1302 storage devices. 1303 Note: 1304 Supported are USB Keyboards and USB Floppy drives 1305 (TEAC FD-05PUB). 1306 MPC5200 USB requires additional defines: 1307 CONFIG_USB_CLOCK 1308 for 528 MHz Clock: 0x0001bbbb 1309 CONFIG_PSC3_USB 1310 for USB on PSC3 1311 CONFIG_USB_CONFIG 1312 for differential drivers: 0x00001000 1313 for single ended drivers: 0x00005000 1314 for differential drivers on PSC3: 0x00000100 1315 for single ended drivers on PSC3: 0x00004100 1316 CONFIG_SYS_USB_EVENT_POLL 1317 May be defined to allow interrupt polling 1318 instead of using asynchronous interrupts 1319 1320 CONFIG_USB_EHCI_TXFIFO_THRESH enables setting of the 1321 txfilltuning field in the EHCI controller on reset. 1322 1323 CONFIG_USB_DWC2_REG_ADDR the physical CPU address of the DWC2 1324 HW module registers. 1325 1326- USB Device: 1327 Define the below if you wish to use the USB console. 1328 Once firmware is rebuilt from a serial console issue the 1329 command "setenv stdin usbtty; setenv stdout usbtty" and 1330 attach your USB cable. The Unix command "dmesg" should print 1331 it has found a new device. The environment variable usbtty 1332 can be set to gserial or cdc_acm to enable your device to 1333 appear to a USB host as a Linux gserial device or a 1334 Common Device Class Abstract Control Model serial device. 1335 If you select usbtty = gserial you should be able to enumerate 1336 a Linux host by 1337 # modprobe usbserial vendor=0xVendorID product=0xProductID 1338 else if using cdc_acm, simply setting the environment 1339 variable usbtty to be cdc_acm should suffice. The following 1340 might be defined in YourBoardName.h 1341 1342 CONFIG_USB_DEVICE 1343 Define this to build a UDC device 1344 1345 CONFIG_USB_TTY 1346 Define this to have a tty type of device available to 1347 talk to the UDC device 1348 1349 CONFIG_USBD_HS 1350 Define this to enable the high speed support for usb 1351 device and usbtty. If this feature is enabled, a routine 1352 int is_usbd_high_speed(void) 1353 also needs to be defined by the driver to dynamically poll 1354 whether the enumeration has succeded at high speed or full 1355 speed. 1356 1357 CONFIG_SYS_CONSOLE_IS_IN_ENV 1358 Define this if you want stdin, stdout &/or stderr to 1359 be set to usbtty. 1360 1361 mpc8xx: 1362 CONFIG_SYS_USB_EXTC_CLK 0xBLAH 1363 Derive USB clock from external clock "blah" 1364 - CONFIG_SYS_USB_EXTC_CLK 0x02 1365 1366 If you have a USB-IF assigned VendorID then you may wish to 1367 define your own vendor specific values either in BoardName.h 1368 or directly in usbd_vendor_info.h. If you don't define 1369 CONFIG_USBD_MANUFACTURER, CONFIG_USBD_PRODUCT_NAME, 1370 CONFIG_USBD_VENDORID and CONFIG_USBD_PRODUCTID, then U-Boot 1371 should pretend to be a Linux device to it's target host. 1372 1373 CONFIG_USBD_MANUFACTURER 1374 Define this string as the name of your company for 1375 - CONFIG_USBD_MANUFACTURER "my company" 1376 1377 CONFIG_USBD_PRODUCT_NAME 1378 Define this string as the name of your product 1379 - CONFIG_USBD_PRODUCT_NAME "acme usb device" 1380 1381 CONFIG_USBD_VENDORID 1382 Define this as your assigned Vendor ID from the USB 1383 Implementors Forum. This *must* be a genuine Vendor ID 1384 to avoid polluting the USB namespace. 1385 - CONFIG_USBD_VENDORID 0xFFFF 1386 1387 CONFIG_USBD_PRODUCTID 1388 Define this as the unique Product ID 1389 for your device 1390 - CONFIG_USBD_PRODUCTID 0xFFFF 1391 1392- ULPI Layer Support: 1393 The ULPI (UTMI Low Pin (count) Interface) PHYs are supported via 1394 the generic ULPI layer. The generic layer accesses the ULPI PHY 1395 via the platform viewport, so you need both the genric layer and 1396 the viewport enabled. Currently only Chipidea/ARC based 1397 viewport is supported. 1398 To enable the ULPI layer support, define CONFIG_USB_ULPI and 1399 CONFIG_USB_ULPI_VIEWPORT in your board configuration file. 1400 If your ULPI phy needs a different reference clock than the 1401 standard 24 MHz then you have to define CONFIG_ULPI_REF_CLK to 1402 the appropriate value in Hz. 1403 1404- MMC Support: 1405 The MMC controller on the Intel PXA is supported. To 1406 enable this define CONFIG_MMC. The MMC can be 1407 accessed from the boot prompt by mapping the device 1408 to physical memory similar to flash. Command line is 1409 enabled with CONFIG_CMD_MMC. The MMC driver also works with 1410 the FAT fs. This is enabled with CONFIG_CMD_FAT. 1411 1412 CONFIG_SH_MMCIF 1413 Support for Renesas on-chip MMCIF controller 1414 1415 CONFIG_SH_MMCIF_ADDR 1416 Define the base address of MMCIF registers 1417 1418 CONFIG_SH_MMCIF_CLK 1419 Define the clock frequency for MMCIF 1420 1421 CONFIG_SUPPORT_EMMC_BOOT 1422 Enable some additional features of the eMMC boot partitions. 1423 1424 CONFIG_SUPPORT_EMMC_RPMB 1425 Enable the commands for reading, writing and programming the 1426 key for the Replay Protection Memory Block partition in eMMC. 1427 1428- USB Device Firmware Update (DFU) class support: 1429 CONFIG_USB_FUNCTION_DFU 1430 This enables the USB portion of the DFU USB class 1431 1432 CONFIG_CMD_DFU 1433 This enables the command "dfu" which is used to have 1434 U-Boot create a DFU class device via USB. This command 1435 requires that the "dfu_alt_info" environment variable be 1436 set and define the alt settings to expose to the host. 1437 1438 CONFIG_DFU_MMC 1439 This enables support for exposing (e)MMC devices via DFU. 1440 1441 CONFIG_DFU_NAND 1442 This enables support for exposing NAND devices via DFU. 1443 1444 CONFIG_DFU_RAM 1445 This enables support for exposing RAM via DFU. 1446 Note: DFU spec refer to non-volatile memory usage, but 1447 allow usages beyond the scope of spec - here RAM usage, 1448 one that would help mostly the developer. 1449 1450 CONFIG_SYS_DFU_DATA_BUF_SIZE 1451 Dfu transfer uses a buffer before writing data to the 1452 raw storage device. Make the size (in bytes) of this buffer 1453 configurable. The size of this buffer is also configurable 1454 through the "dfu_bufsiz" environment variable. 1455 1456 CONFIG_SYS_DFU_MAX_FILE_SIZE 1457 When updating files rather than the raw storage device, 1458 we use a static buffer to copy the file into and then write 1459 the buffer once we've been given the whole file. Define 1460 this to the maximum filesize (in bytes) for the buffer. 1461 Default is 4 MiB if undefined. 1462 1463 DFU_DEFAULT_POLL_TIMEOUT 1464 Poll timeout [ms], is the timeout a device can send to the 1465 host. The host must wait for this timeout before sending 1466 a subsequent DFU_GET_STATUS request to the device. 1467 1468 DFU_MANIFEST_POLL_TIMEOUT 1469 Poll timeout [ms], which the device sends to the host when 1470 entering dfuMANIFEST state. Host waits this timeout, before 1471 sending again an USB request to the device. 1472 1473- USB Device Android Fastboot support: 1474 CONFIG_USB_FUNCTION_FASTBOOT 1475 This enables the USB part of the fastboot gadget 1476 1477 CONFIG_CMD_FASTBOOT 1478 This enables the command "fastboot" which enables the Android 1479 fastboot mode for the platform's USB device. Fastboot is a USB 1480 protocol for downloading images, flashing and device control 1481 used on Android devices. 1482 See doc/README.android-fastboot for more information. 1483 1484 CONFIG_ANDROID_BOOT_IMAGE 1485 This enables support for booting images which use the Android 1486 image format header. 1487 1488 CONFIG_FASTBOOT_BUF_ADDR 1489 The fastboot protocol requires a large memory buffer for 1490 downloads. Define this to the starting RAM address to use for 1491 downloaded images. 1492 1493 CONFIG_FASTBOOT_BUF_SIZE 1494 The fastboot protocol requires a large memory buffer for 1495 downloads. This buffer should be as large as possible for a 1496 platform. Define this to the size available RAM for fastboot. 1497 1498 CONFIG_FASTBOOT_FLASH 1499 The fastboot protocol includes a "flash" command for writing 1500 the downloaded image to a non-volatile storage device. Define 1501 this to enable the "fastboot flash" command. 1502 1503 CONFIG_FASTBOOT_FLASH_MMC_DEV 1504 The fastboot "flash" command requires additional information 1505 regarding the non-volatile storage device. Define this to 1506 the eMMC device that fastboot should use to store the image. 1507 1508 CONFIG_FASTBOOT_GPT_NAME 1509 The fastboot "flash" command supports writing the downloaded 1510 image to the Protective MBR and the Primary GUID Partition 1511 Table. (Additionally, this downloaded image is post-processed 1512 to generate and write the Backup GUID Partition Table.) 1513 This occurs when the specified "partition name" on the 1514 "fastboot flash" command line matches this value. 1515 The default is "gpt" if undefined. 1516 1517 CONFIG_FASTBOOT_MBR_NAME 1518 The fastboot "flash" command supports writing the downloaded 1519 image to DOS MBR. 1520 This occurs when the "partition name" specified on the 1521 "fastboot flash" command line matches this value. 1522 If not defined the default value "mbr" is used. 1523 1524- Journaling Flash filesystem support: 1525 CONFIG_JFFS2_NAND 1526 Define these for a default partition on a NAND device 1527 1528 CONFIG_SYS_JFFS2_FIRST_SECTOR, 1529 CONFIG_SYS_JFFS2_FIRST_BANK, CONFIG_SYS_JFFS2_NUM_BANKS 1530 Define these for a default partition on a NOR device 1531 1532- FAT(File Allocation Table) filesystem write function support: 1533 CONFIG_FAT_WRITE 1534 1535 Define this to enable support for saving memory data as a 1536 file in FAT formatted partition. 1537 1538 This will also enable the command "fatwrite" enabling the 1539 user to write files to FAT. 1540 1541- FAT(File Allocation Table) filesystem cluster size: 1542 CONFIG_FS_FAT_MAX_CLUSTSIZE 1543 1544 Define the max cluster size for fat operations else 1545 a default value of 65536 will be defined. 1546 1547- Keyboard Support: 1548 See Kconfig help for available keyboard drivers. 1549 1550 CONFIG_KEYBOARD 1551 1552 Define this to enable a custom keyboard support. 1553 This simply calls drv_keyboard_init() which must be 1554 defined in your board-specific files. This option is deprecated 1555 and is only used by novena. For new boards, use driver model 1556 instead. 1557 1558- Video support: 1559 CONFIG_FSL_DIU_FB 1560 Enable the Freescale DIU video driver. Reference boards for 1561 SOCs that have a DIU should define this macro to enable DIU 1562 support, and should also define these other macros: 1563 1564 CONFIG_SYS_DIU_ADDR 1565 CONFIG_VIDEO 1566 CONFIG_CFB_CONSOLE 1567 CONFIG_VIDEO_SW_CURSOR 1568 CONFIG_VGA_AS_SINGLE_DEVICE 1569 CONFIG_VIDEO_LOGO 1570 CONFIG_VIDEO_BMP_LOGO 1571 1572 The DIU driver will look for the 'video-mode' environment 1573 variable, and if defined, enable the DIU as a console during 1574 boot. See the documentation file doc/README.video for a 1575 description of this variable. 1576 1577- LCD Support: CONFIG_LCD 1578 1579 Define this to enable LCD support (for output to LCD 1580 display); also select one of the supported displays 1581 by defining one of these: 1582 1583 CONFIG_ATMEL_LCD: 1584 1585 HITACHI TX09D70VM1CCA, 3.5", 240x320. 1586 1587 CONFIG_NEC_NL6448AC33: 1588 1589 NEC NL6448AC33-18. Active, color, single scan. 1590 1591 CONFIG_NEC_NL6448BC20 1592 1593 NEC NL6448BC20-08. 6.5", 640x480. 1594 Active, color, single scan. 1595 1596 CONFIG_NEC_NL6448BC33_54 1597 1598 NEC NL6448BC33-54. 10.4", 640x480. 1599 Active, color, single scan. 1600 1601 CONFIG_SHARP_16x9 1602 1603 Sharp 320x240. Active, color, single scan. 1604 It isn't 16x9, and I am not sure what it is. 1605 1606 CONFIG_SHARP_LQ64D341 1607 1608 Sharp LQ64D341 display, 640x480. 1609 Active, color, single scan. 1610 1611 CONFIG_HLD1045 1612 1613 HLD1045 display, 640x480. 1614 Active, color, single scan. 1615 1616 CONFIG_OPTREX_BW 1617 1618 Optrex CBL50840-2 NF-FW 99 22 M5 1619 or 1620 Hitachi LMG6912RPFC-00T 1621 or 1622 Hitachi SP14Q002 1623 1624 320x240. Black & white. 1625 1626 CONFIG_LCD_ALIGNMENT 1627 1628 Normally the LCD is page-aligned (typically 4KB). If this is 1629 defined then the LCD will be aligned to this value instead. 1630 For ARM it is sometimes useful to use MMU_SECTION_SIZE 1631 here, since it is cheaper to change data cache settings on 1632 a per-section basis. 1633 1634 1635 CONFIG_LCD_ROTATION 1636 1637 Sometimes, for example if the display is mounted in portrait 1638 mode or even if it's mounted landscape but rotated by 180degree, 1639 we need to rotate our content of the display relative to the 1640 framebuffer, so that user can read the messages which are 1641 printed out. 1642 Once CONFIG_LCD_ROTATION is defined, the lcd_console will be 1643 initialized with a given rotation from "vl_rot" out of 1644 "vidinfo_t" which is provided by the board specific code. 1645 The value for vl_rot is coded as following (matching to 1646 fbcon=rotate:<n> linux-kernel commandline): 1647 0 = no rotation respectively 0 degree 1648 1 = 90 degree rotation 1649 2 = 180 degree rotation 1650 3 = 270 degree rotation 1651 1652 If CONFIG_LCD_ROTATION is not defined, the console will be 1653 initialized with 0degree rotation. 1654 1655 CONFIG_LCD_BMP_RLE8 1656 1657 Support drawing of RLE8-compressed bitmaps on the LCD. 1658 1659 CONFIG_I2C_EDID 1660 1661 Enables an 'i2c edid' command which can read EDID 1662 information over I2C from an attached LCD display. 1663 1664- Splash Screen Support: CONFIG_SPLASH_SCREEN 1665 1666 If this option is set, the environment is checked for 1667 a variable "splashimage". If found, the usual display 1668 of logo, copyright and system information on the LCD 1669 is suppressed and the BMP image at the address 1670 specified in "splashimage" is loaded instead. The 1671 console is redirected to the "nulldev", too. This 1672 allows for a "silent" boot where a splash screen is 1673 loaded very quickly after power-on. 1674 1675 CONFIG_SPLASHIMAGE_GUARD 1676 1677 If this option is set, then U-Boot will prevent the environment 1678 variable "splashimage" from being set to a problematic address 1679 (see doc/README.displaying-bmps). 1680 This option is useful for targets where, due to alignment 1681 restrictions, an improperly aligned BMP image will cause a data 1682 abort. If you think you will not have problems with unaligned 1683 accesses (for example because your toolchain prevents them) 1684 there is no need to set this option. 1685 1686 CONFIG_SPLASH_SCREEN_ALIGN 1687 1688 If this option is set the splash image can be freely positioned 1689 on the screen. Environment variable "splashpos" specifies the 1690 position as "x,y". If a positive number is given it is used as 1691 number of pixel from left/top. If a negative number is given it 1692 is used as number of pixel from right/bottom. You can also 1693 specify 'm' for centering the image. 1694 1695 Example: 1696 setenv splashpos m,m 1697 => image at center of screen 1698 1699 setenv splashpos 30,20 1700 => image at x = 30 and y = 20 1701 1702 setenv splashpos -10,m 1703 => vertically centered image 1704 at x = dspWidth - bmpWidth - 9 1705 1706- Gzip compressed BMP image support: CONFIG_VIDEO_BMP_GZIP 1707 1708 If this option is set, additionally to standard BMP 1709 images, gzipped BMP images can be displayed via the 1710 splashscreen support or the bmp command. 1711 1712- Run length encoded BMP image (RLE8) support: CONFIG_VIDEO_BMP_RLE8 1713 1714 If this option is set, 8-bit RLE compressed BMP images 1715 can be displayed via the splashscreen support or the 1716 bmp command. 1717 1718- Compression support: 1719 CONFIG_GZIP 1720 1721 Enabled by default to support gzip compressed images. 1722 1723 CONFIG_BZIP2 1724 1725 If this option is set, support for bzip2 compressed 1726 images is included. If not, only uncompressed and gzip 1727 compressed images are supported. 1728 1729 NOTE: the bzip2 algorithm requires a lot of RAM, so 1730 the malloc area (as defined by CONFIG_SYS_MALLOC_LEN) should 1731 be at least 4MB. 1732 1733 CONFIG_LZMA 1734 1735 If this option is set, support for lzma compressed 1736 images is included. 1737 1738 Note: The LZMA algorithm adds between 2 and 4KB of code and it 1739 requires an amount of dynamic memory that is given by the 1740 formula: 1741 1742 (1846 + 768 << (lc + lp)) * sizeof(uint16) 1743 1744 Where lc and lp stand for, respectively, Literal context bits 1745 and Literal pos bits. 1746 1747 This value is upper-bounded by 14MB in the worst case. Anyway, 1748 for a ~4MB large kernel image, we have lc=3 and lp=0 for a 1749 total amount of (1846 + 768 << (3 + 0)) * 2 = ~41KB... that is 1750 a very small buffer. 1751 1752 Use the lzmainfo tool to determinate the lc and lp values and 1753 then calculate the amount of needed dynamic memory (ensuring 1754 the appropriate CONFIG_SYS_MALLOC_LEN value). 1755 1756 CONFIG_LZO 1757 1758 If this option is set, support for LZO compressed images 1759 is included. 1760 1761- MII/PHY support: 1762 CONFIG_PHY_ADDR 1763 1764 The address of PHY on MII bus. 1765 1766 CONFIG_PHY_CLOCK_FREQ (ppc4xx) 1767 1768 The clock frequency of the MII bus 1769 1770 CONFIG_PHY_GIGE 1771 1772 If this option is set, support for speed/duplex 1773 detection of gigabit PHY is included. 1774 1775 CONFIG_PHY_RESET_DELAY 1776 1777 Some PHY like Intel LXT971A need extra delay after 1778 reset before any MII register access is possible. 1779 For such PHY, set this option to the usec delay 1780 required. (minimum 300usec for LXT971A) 1781 1782 CONFIG_PHY_CMD_DELAY (ppc4xx) 1783 1784 Some PHY like Intel LXT971A need extra delay after 1785 command issued before MII status register can be read 1786 1787- IP address: 1788 CONFIG_IPADDR 1789 1790 Define a default value for the IP address to use for 1791 the default Ethernet interface, in case this is not 1792 determined through e.g. bootp. 1793 (Environment variable "ipaddr") 1794 1795- Server IP address: 1796 CONFIG_SERVERIP 1797 1798 Defines a default value for the IP address of a TFTP 1799 server to contact when using the "tftboot" command. 1800 (Environment variable "serverip") 1801 1802 CONFIG_KEEP_SERVERADDR 1803 1804 Keeps the server's MAC address, in the env 'serveraddr' 1805 for passing to bootargs (like Linux's netconsole option) 1806 1807- Gateway IP address: 1808 CONFIG_GATEWAYIP 1809 1810 Defines a default value for the IP address of the 1811 default router where packets to other networks are 1812 sent to. 1813 (Environment variable "gatewayip") 1814 1815- Subnet mask: 1816 CONFIG_NETMASK 1817 1818 Defines a default value for the subnet mask (or 1819 routing prefix) which is used to determine if an IP 1820 address belongs to the local subnet or needs to be 1821 forwarded through a router. 1822 (Environment variable "netmask") 1823 1824- Multicast TFTP Mode: 1825 CONFIG_MCAST_TFTP 1826 1827 Defines whether you want to support multicast TFTP as per 1828 rfc-2090; for example to work with atftp. Lets lots of targets 1829 tftp down the same boot image concurrently. Note: the Ethernet 1830 driver in use must provide a function: mcast() to join/leave a 1831 multicast group. 1832 1833- BOOTP Recovery Mode: 1834 CONFIG_BOOTP_RANDOM_DELAY 1835 1836 If you have many targets in a network that try to 1837 boot using BOOTP, you may want to avoid that all 1838 systems send out BOOTP requests at precisely the same 1839 moment (which would happen for instance at recovery 1840 from a power failure, when all systems will try to 1841 boot, thus flooding the BOOTP server. Defining 1842 CONFIG_BOOTP_RANDOM_DELAY causes a random delay to be 1843 inserted before sending out BOOTP requests. The 1844 following delays are inserted then: 1845 1846 1st BOOTP request: delay 0 ... 1 sec 1847 2nd BOOTP request: delay 0 ... 2 sec 1848 3rd BOOTP request: delay 0 ... 4 sec 1849 4th and following 1850 BOOTP requests: delay 0 ... 8 sec 1851 1852 CONFIG_BOOTP_ID_CACHE_SIZE 1853 1854 BOOTP packets are uniquely identified using a 32-bit ID. The 1855 server will copy the ID from client requests to responses and 1856 U-Boot will use this to determine if it is the destination of 1857 an incoming response. Some servers will check that addresses 1858 aren't in use before handing them out (usually using an ARP 1859 ping) and therefore take up to a few hundred milliseconds to 1860 respond. Network congestion may also influence the time it 1861 takes for a response to make it back to the client. If that 1862 time is too long, U-Boot will retransmit requests. In order 1863 to allow earlier responses to still be accepted after these 1864 retransmissions, U-Boot's BOOTP client keeps a small cache of 1865 IDs. The CONFIG_BOOTP_ID_CACHE_SIZE controls the size of this 1866 cache. The default is to keep IDs for up to four outstanding 1867 requests. Increasing this will allow U-Boot to accept offers 1868 from a BOOTP client in networks with unusually high latency. 1869 1870- DHCP Advanced Options: 1871 You can fine tune the DHCP functionality by defining 1872 CONFIG_BOOTP_* symbols: 1873 1874 CONFIG_BOOTP_SUBNETMASK 1875 CONFIG_BOOTP_GATEWAY 1876 CONFIG_BOOTP_HOSTNAME 1877 CONFIG_BOOTP_NISDOMAIN 1878 CONFIG_BOOTP_BOOTPATH 1879 CONFIG_BOOTP_BOOTFILESIZE 1880 CONFIG_BOOTP_DNS 1881 CONFIG_BOOTP_DNS2 1882 CONFIG_BOOTP_SEND_HOSTNAME 1883 CONFIG_BOOTP_NTPSERVER 1884 CONFIG_BOOTP_TIMEOFFSET 1885 CONFIG_BOOTP_VENDOREX 1886 CONFIG_BOOTP_MAY_FAIL 1887 1888 CONFIG_BOOTP_SERVERIP - TFTP server will be the serverip 1889 environment variable, not the BOOTP server. 1890 1891 CONFIG_BOOTP_MAY_FAIL - If the DHCP server is not found 1892 after the configured retry count, the call will fail 1893 instead of starting over. This can be used to fail over 1894 to Link-local IP address configuration if the DHCP server 1895 is not available. 1896 1897 CONFIG_BOOTP_DNS2 - If a DHCP client requests the DNS 1898 serverip from a DHCP server, it is possible that more 1899 than one DNS serverip is offered to the client. 1900 If CONFIG_BOOTP_DNS2 is enabled, the secondary DNS 1901 serverip will be stored in the additional environment 1902 variable "dnsip2". The first DNS serverip is always 1903 stored in the variable "dnsip", when CONFIG_BOOTP_DNS 1904 is defined. 1905 1906 CONFIG_BOOTP_SEND_HOSTNAME - Some DHCP servers are capable 1907 to do a dynamic update of a DNS server. To do this, they 1908 need the hostname of the DHCP requester. 1909 If CONFIG_BOOTP_SEND_HOSTNAME is defined, the content 1910 of the "hostname" environment variable is passed as 1911 option 12 to the DHCP server. 1912 1913 CONFIG_BOOTP_DHCP_REQUEST_DELAY 1914 1915 A 32bit value in microseconds for a delay between 1916 receiving a "DHCP Offer" and sending the "DHCP Request". 1917 This fixes a problem with certain DHCP servers that don't 1918 respond 100% of the time to a "DHCP request". E.g. On an 1919 AT91RM9200 processor running at 180MHz, this delay needed 1920 to be *at least* 15,000 usec before a Windows Server 2003 1921 DHCP server would reply 100% of the time. I recommend at 1922 least 50,000 usec to be safe. The alternative is to hope 1923 that one of the retries will be successful but note that 1924 the DHCP timeout and retry process takes a longer than 1925 this delay. 1926 1927 - Link-local IP address negotiation: 1928 Negotiate with other link-local clients on the local network 1929 for an address that doesn't require explicit configuration. 1930 This is especially useful if a DHCP server cannot be guaranteed 1931 to exist in all environments that the device must operate. 1932 1933 See doc/README.link-local for more information. 1934 1935 - CDP Options: 1936 CONFIG_CDP_DEVICE_ID 1937 1938 The device id used in CDP trigger frames. 1939 1940 CONFIG_CDP_DEVICE_ID_PREFIX 1941 1942 A two character string which is prefixed to the MAC address 1943 of the device. 1944 1945 CONFIG_CDP_PORT_ID 1946 1947 A printf format string which contains the ascii name of 1948 the port. Normally is set to "eth%d" which sets 1949 eth0 for the first Ethernet, eth1 for the second etc. 1950 1951 CONFIG_CDP_CAPABILITIES 1952 1953 A 32bit integer which indicates the device capabilities; 1954 0x00000010 for a normal host which does not forwards. 1955 1956 CONFIG_CDP_VERSION 1957 1958 An ascii string containing the version of the software. 1959 1960 CONFIG_CDP_PLATFORM 1961 1962 An ascii string containing the name of the platform. 1963 1964 CONFIG_CDP_TRIGGER 1965 1966 A 32bit integer sent on the trigger. 1967 1968 CONFIG_CDP_POWER_CONSUMPTION 1969 1970 A 16bit integer containing the power consumption of the 1971 device in .1 of milliwatts. 1972 1973 CONFIG_CDP_APPLIANCE_VLAN_TYPE 1974 1975 A byte containing the id of the VLAN. 1976 1977- Status LED: CONFIG_LED_STATUS 1978 1979 Several configurations allow to display the current 1980 status using a LED. For instance, the LED will blink 1981 fast while running U-Boot code, stop blinking as 1982 soon as a reply to a BOOTP request was received, and 1983 start blinking slow once the Linux kernel is running 1984 (supported by a status LED driver in the Linux 1985 kernel). Defining CONFIG_LED_STATUS enables this 1986 feature in U-Boot. 1987 1988 Additional options: 1989 1990 CONFIG_LED_STATUS_GPIO 1991 The status LED can be connected to a GPIO pin. 1992 In such cases, the gpio_led driver can be used as a 1993 status LED backend implementation. Define CONFIG_LED_STATUS_GPIO 1994 to include the gpio_led driver in the U-Boot binary. 1995 1996 CONFIG_GPIO_LED_INVERTED_TABLE 1997 Some GPIO connected LEDs may have inverted polarity in which 1998 case the GPIO high value corresponds to LED off state and 1999 GPIO low value corresponds to LED on state. 2000 In such cases CONFIG_GPIO_LED_INVERTED_TABLE may be defined 2001 with a list of GPIO LEDs that have inverted polarity. 2002 2003- CAN Support: CONFIG_CAN_DRIVER 2004 2005 Defining CONFIG_CAN_DRIVER enables CAN driver support 2006 on those systems that support this (optional) 2007 feature, like the TQM8xxL modules. 2008 2009- I2C Support: CONFIG_SYS_I2C 2010 2011 This enable the NEW i2c subsystem, and will allow you to use 2012 i2c commands at the u-boot command line (as long as you set 2013 CONFIG_CMD_I2C in CONFIG_COMMANDS) and communicate with i2c 2014 based realtime clock chips or other i2c devices. See 2015 common/cmd_i2c.c for a description of the command line 2016 interface. 2017 2018 ported i2c driver to the new framework: 2019 - drivers/i2c/soft_i2c.c: 2020 - activate first bus with CONFIG_SYS_I2C_SOFT define 2021 CONFIG_SYS_I2C_SOFT_SPEED and CONFIG_SYS_I2C_SOFT_SLAVE 2022 for defining speed and slave address 2023 - activate second bus with I2C_SOFT_DECLARATIONS2 define 2024 CONFIG_SYS_I2C_SOFT_SPEED_2 and CONFIG_SYS_I2C_SOFT_SLAVE_2 2025 for defining speed and slave address 2026 - activate third bus with I2C_SOFT_DECLARATIONS3 define 2027 CONFIG_SYS_I2C_SOFT_SPEED_3 and CONFIG_SYS_I2C_SOFT_SLAVE_3 2028 for defining speed and slave address 2029 - activate fourth bus with I2C_SOFT_DECLARATIONS4 define 2030 CONFIG_SYS_I2C_SOFT_SPEED_4 and CONFIG_SYS_I2C_SOFT_SLAVE_4 2031 for defining speed and slave address 2032 2033 - drivers/i2c/fsl_i2c.c: 2034 - activate i2c driver with CONFIG_SYS_I2C_FSL 2035 define CONFIG_SYS_FSL_I2C_OFFSET for setting the register 2036 offset CONFIG_SYS_FSL_I2C_SPEED for the i2c speed and 2037 CONFIG_SYS_FSL_I2C_SLAVE for the slave addr of the first 2038 bus. 2039 - If your board supports a second fsl i2c bus, define 2040 CONFIG_SYS_FSL_I2C2_OFFSET for the register offset 2041 CONFIG_SYS_FSL_I2C2_SPEED for the speed and 2042 CONFIG_SYS_FSL_I2C2_SLAVE for the slave address of the 2043 second bus. 2044 2045 - drivers/i2c/tegra_i2c.c: 2046 - activate this driver with CONFIG_SYS_I2C_TEGRA 2047 - This driver adds 4 i2c buses with a fix speed from 2048 100000 and the slave addr 0! 2049 2050 - drivers/i2c/ppc4xx_i2c.c 2051 - activate this driver with CONFIG_SYS_I2C_PPC4XX 2052 - CONFIG_SYS_I2C_PPC4XX_CH0 activate hardware channel 0 2053 - CONFIG_SYS_I2C_PPC4XX_CH1 activate hardware channel 1 2054 2055 - drivers/i2c/i2c_mxc.c 2056 - activate this driver with CONFIG_SYS_I2C_MXC 2057 - enable bus 1 with CONFIG_SYS_I2C_MXC_I2C1 2058 - enable bus 2 with CONFIG_SYS_I2C_MXC_I2C2 2059 - enable bus 3 with CONFIG_SYS_I2C_MXC_I2C3 2060 - enable bus 4 with CONFIG_SYS_I2C_MXC_I2C4 2061 - define speed for bus 1 with CONFIG_SYS_MXC_I2C1_SPEED 2062 - define slave for bus 1 with CONFIG_SYS_MXC_I2C1_SLAVE 2063 - define speed for bus 2 with CONFIG_SYS_MXC_I2C2_SPEED 2064 - define slave for bus 2 with CONFIG_SYS_MXC_I2C2_SLAVE 2065 - define speed for bus 3 with CONFIG_SYS_MXC_I2C3_SPEED 2066 - define slave for bus 3 with CONFIG_SYS_MXC_I2C3_SLAVE 2067 - define speed for bus 4 with CONFIG_SYS_MXC_I2C4_SPEED 2068 - define slave for bus 4 with CONFIG_SYS_MXC_I2C4_SLAVE 2069 If those defines are not set, default value is 100000 2070 for speed, and 0 for slave. 2071 2072 - drivers/i2c/rcar_i2c.c: 2073 - activate this driver with CONFIG_SYS_I2C_RCAR 2074 - This driver adds 4 i2c buses 2075 2076 - CONFIG_SYS_RCAR_I2C0_BASE for setting the register channel 0 2077 - CONFIG_SYS_RCAR_I2C0_SPEED for for the speed channel 0 2078 - CONFIG_SYS_RCAR_I2C1_BASE for setting the register channel 1 2079 - CONFIG_SYS_RCAR_I2C1_SPEED for for the speed channel 1 2080 - CONFIG_SYS_RCAR_I2C2_BASE for setting the register channel 2 2081 - CONFIG_SYS_RCAR_I2C2_SPEED for for the speed channel 2 2082 - CONFIG_SYS_RCAR_I2C3_BASE for setting the register channel 3 2083 - CONFIG_SYS_RCAR_I2C3_SPEED for for the speed channel 3 2084 - CONFIF_SYS_RCAR_I2C_NUM_CONTROLLERS for number of i2c buses 2085 2086 - drivers/i2c/sh_i2c.c: 2087 - activate this driver with CONFIG_SYS_I2C_SH 2088 - This driver adds from 2 to 5 i2c buses 2089 2090 - CONFIG_SYS_I2C_SH_BASE0 for setting the register channel 0 2091 - CONFIG_SYS_I2C_SH_SPEED0 for for the speed channel 0 2092 - CONFIG_SYS_I2C_SH_BASE1 for setting the register channel 1 2093 - CONFIG_SYS_I2C_SH_SPEED1 for for the speed channel 1 2094 - CONFIG_SYS_I2C_SH_BASE2 for setting the register channel 2 2095 - CONFIG_SYS_I2C_SH_SPEED2 for for the speed channel 2 2096 - CONFIG_SYS_I2C_SH_BASE3 for setting the register channel 3 2097 - CONFIG_SYS_I2C_SH_SPEED3 for for the speed channel 3 2098 - CONFIG_SYS_I2C_SH_BASE4 for setting the register channel 4 2099 - CONFIG_SYS_I2C_SH_SPEED4 for for the speed channel 4 2100 - CONFIG_SYS_I2C_SH_NUM_CONTROLLERS for number of i2c buses 2101 2102 - drivers/i2c/omap24xx_i2c.c 2103 - activate this driver with CONFIG_SYS_I2C_OMAP24XX 2104 - CONFIG_SYS_OMAP24_I2C_SPEED speed channel 0 2105 - CONFIG_SYS_OMAP24_I2C_SLAVE slave addr channel 0 2106 - CONFIG_SYS_OMAP24_I2C_SPEED1 speed channel 1 2107 - CONFIG_SYS_OMAP24_I2C_SLAVE1 slave addr channel 1 2108 - CONFIG_SYS_OMAP24_I2C_SPEED2 speed channel 2 2109 - CONFIG_SYS_OMAP24_I2C_SLAVE2 slave addr channel 2 2110 - CONFIG_SYS_OMAP24_I2C_SPEED3 speed channel 3 2111 - CONFIG_SYS_OMAP24_I2C_SLAVE3 slave addr channel 3 2112 - CONFIG_SYS_OMAP24_I2C_SPEED4 speed channel 4 2113 - CONFIG_SYS_OMAP24_I2C_SLAVE4 slave addr channel 4 2114 2115 - drivers/i2c/zynq_i2c.c 2116 - activate this driver with CONFIG_SYS_I2C_ZYNQ 2117 - set CONFIG_SYS_I2C_ZYNQ_SPEED for speed setting 2118 - set CONFIG_SYS_I2C_ZYNQ_SLAVE for slave addr 2119 2120 - drivers/i2c/s3c24x0_i2c.c: 2121 - activate this driver with CONFIG_SYS_I2C_S3C24X0 2122 - This driver adds i2c buses (11 for Exynos5250, Exynos5420 2123 9 i2c buses for Exynos4 and 1 for S3C24X0 SoCs from Samsung) 2124 with a fix speed from 100000 and the slave addr 0! 2125 2126 - drivers/i2c/ihs_i2c.c 2127 - activate this driver with CONFIG_SYS_I2C_IHS 2128 - CONFIG_SYS_I2C_IHS_CH0 activate hardware channel 0 2129 - CONFIG_SYS_I2C_IHS_SPEED_0 speed channel 0 2130 - CONFIG_SYS_I2C_IHS_SLAVE_0 slave addr channel 0 2131 - CONFIG_SYS_I2C_IHS_CH1 activate hardware channel 1 2132 - CONFIG_SYS_I2C_IHS_SPEED_1 speed channel 1 2133 - CONFIG_SYS_I2C_IHS_SLAVE_1 slave addr channel 1 2134 - CONFIG_SYS_I2C_IHS_CH2 activate hardware channel 2 2135 - CONFIG_SYS_I2C_IHS_SPEED_2 speed channel 2 2136 - CONFIG_SYS_I2C_IHS_SLAVE_2 slave addr channel 2 2137 - CONFIG_SYS_I2C_IHS_CH3 activate hardware channel 3 2138 - CONFIG_SYS_I2C_IHS_SPEED_3 speed channel 3 2139 - CONFIG_SYS_I2C_IHS_SLAVE_3 slave addr channel 3 2140 - activate dual channel with CONFIG_SYS_I2C_IHS_DUAL 2141 - CONFIG_SYS_I2C_IHS_SPEED_0_1 speed channel 0_1 2142 - CONFIG_SYS_I2C_IHS_SLAVE_0_1 slave addr channel 0_1 2143 - CONFIG_SYS_I2C_IHS_SPEED_1_1 speed channel 1_1 2144 - CONFIG_SYS_I2C_IHS_SLAVE_1_1 slave addr channel 1_1 2145 - CONFIG_SYS_I2C_IHS_SPEED_2_1 speed channel 2_1 2146 - CONFIG_SYS_I2C_IHS_SLAVE_2_1 slave addr channel 2_1 2147 - CONFIG_SYS_I2C_IHS_SPEED_3_1 speed channel 3_1 2148 - CONFIG_SYS_I2C_IHS_SLAVE_3_1 slave addr channel 3_1 2149 2150 additional defines: 2151 2152 CONFIG_SYS_NUM_I2C_BUSES 2153 Hold the number of i2c buses you want to use. 2154 2155 CONFIG_SYS_I2C_DIRECT_BUS 2156 define this, if you don't use i2c muxes on your hardware. 2157 if CONFIG_SYS_I2C_MAX_HOPS is not defined or == 0 you can 2158 omit this define. 2159 2160 CONFIG_SYS_I2C_MAX_HOPS 2161 define how many muxes are maximal consecutively connected 2162 on one i2c bus. If you not use i2c muxes, omit this 2163 define. 2164 2165 CONFIG_SYS_I2C_BUSES 2166 hold a list of buses you want to use, only used if 2167 CONFIG_SYS_I2C_DIRECT_BUS is not defined, for example 2168 a board with CONFIG_SYS_I2C_MAX_HOPS = 1 and 2169 CONFIG_SYS_NUM_I2C_BUSES = 9: 2170 2171 CONFIG_SYS_I2C_BUSES {{0, {I2C_NULL_HOP}}, \ 2172 {0, {{I2C_MUX_PCA9547, 0x70, 1}}}, \ 2173 {0, {{I2C_MUX_PCA9547, 0x70, 2}}}, \ 2174 {0, {{I2C_MUX_PCA9547, 0x70, 3}}}, \ 2175 {0, {{I2C_MUX_PCA9547, 0x70, 4}}}, \ 2176 {0, {{I2C_MUX_PCA9547, 0x70, 5}}}, \ 2177 {1, {I2C_NULL_HOP}}, \ 2178 {1, {{I2C_MUX_PCA9544, 0x72, 1}}}, \ 2179 {1, {{I2C_MUX_PCA9544, 0x72, 2}}}, \ 2180 } 2181 2182 which defines 2183 bus 0 on adapter 0 without a mux 2184 bus 1 on adapter 0 with a PCA9547 on address 0x70 port 1 2185 bus 2 on adapter 0 with a PCA9547 on address 0x70 port 2 2186 bus 3 on adapter 0 with a PCA9547 on address 0x70 port 3 2187 bus 4 on adapter 0 with a PCA9547 on address 0x70 port 4 2188 bus 5 on adapter 0 with a PCA9547 on address 0x70 port 5 2189 bus 6 on adapter 1 without a mux 2190 bus 7 on adapter 1 with a PCA9544 on address 0x72 port 1 2191 bus 8 on adapter 1 with a PCA9544 on address 0x72 port 2 2192 2193 If you do not have i2c muxes on your board, omit this define. 2194 2195- Legacy I2C Support: 2196 If you use the software i2c interface (CONFIG_SYS_I2C_SOFT) 2197 then the following macros need to be defined (examples are 2198 from include/configs/lwmon.h): 2199 2200 I2C_INIT 2201 2202 (Optional). Any commands necessary to enable the I2C 2203 controller or configure ports. 2204 2205 eg: #define I2C_INIT (immr->im_cpm.cp_pbdir |= PB_SCL) 2206 2207 I2C_PORT 2208 2209 (Only for MPC8260 CPU). The I/O port to use (the code 2210 assumes both bits are on the same port). Valid values 2211 are 0..3 for ports A..D. 2212 2213 I2C_ACTIVE 2214 2215 The code necessary to make the I2C data line active 2216 (driven). If the data line is open collector, this 2217 define can be null. 2218 2219 eg: #define I2C_ACTIVE (immr->im_cpm.cp_pbdir |= PB_SDA) 2220 2221 I2C_TRISTATE 2222 2223 The code necessary to make the I2C data line tri-stated 2224 (inactive). If the data line is open collector, this 2225 define can be null. 2226 2227 eg: #define I2C_TRISTATE (immr->im_cpm.cp_pbdir &= ~PB_SDA) 2228 2229 I2C_READ 2230 2231 Code that returns true if the I2C data line is high, 2232 false if it is low. 2233 2234 eg: #define I2C_READ ((immr->im_cpm.cp_pbdat & PB_SDA) != 0) 2235 2236 I2C_SDA(bit) 2237 2238 If <bit> is true, sets the I2C data line high. If it 2239 is false, it clears it (low). 2240 2241 eg: #define I2C_SDA(bit) \ 2242 if(bit) immr->im_cpm.cp_pbdat |= PB_SDA; \ 2243 else immr->im_cpm.cp_pbdat &= ~PB_SDA 2244 2245 I2C_SCL(bit) 2246 2247 If <bit> is true, sets the I2C clock line high. If it 2248 is false, it clears it (low). 2249 2250 eg: #define I2C_SCL(bit) \ 2251 if(bit) immr->im_cpm.cp_pbdat |= PB_SCL; \ 2252 else immr->im_cpm.cp_pbdat &= ~PB_SCL 2253 2254 I2C_DELAY 2255 2256 This delay is invoked four times per clock cycle so this 2257 controls the rate of data transfer. The data rate thus 2258 is 1 / (I2C_DELAY * 4). Often defined to be something 2259 like: 2260 2261 #define I2C_DELAY udelay(2) 2262 2263 CONFIG_SOFT_I2C_GPIO_SCL / CONFIG_SOFT_I2C_GPIO_SDA 2264 2265 If your arch supports the generic GPIO framework (asm/gpio.h), 2266 then you may alternatively define the two GPIOs that are to be 2267 used as SCL / SDA. Any of the previous I2C_xxx macros will 2268 have GPIO-based defaults assigned to them as appropriate. 2269 2270 You should define these to the GPIO value as given directly to 2271 the generic GPIO functions. 2272 2273 CONFIG_SYS_I2C_INIT_BOARD 2274 2275 When a board is reset during an i2c bus transfer 2276 chips might think that the current transfer is still 2277 in progress. On some boards it is possible to access 2278 the i2c SCLK line directly, either by using the 2279 processor pin as a GPIO or by having a second pin 2280 connected to the bus. If this option is defined a 2281 custom i2c_init_board() routine in boards/xxx/board.c 2282 is run early in the boot sequence. 2283 2284 CONFIG_I2C_MULTI_BUS 2285 2286 This option allows the use of multiple I2C buses, each of which 2287 must have a controller. At any point in time, only one bus is 2288 active. To switch to a different bus, use the 'i2c dev' command. 2289 Note that bus numbering is zero-based. 2290 2291 CONFIG_SYS_I2C_NOPROBES 2292 2293 This option specifies a list of I2C devices that will be skipped 2294 when the 'i2c probe' command is issued. If CONFIG_I2C_MULTI_BUS 2295 is set, specify a list of bus-device pairs. Otherwise, specify 2296 a 1D array of device addresses 2297 2298 e.g. 2299 #undef CONFIG_I2C_MULTI_BUS 2300 #define CONFIG_SYS_I2C_NOPROBES {0x50,0x68} 2301 2302 will skip addresses 0x50 and 0x68 on a board with one I2C bus 2303 2304 #define CONFIG_I2C_MULTI_BUS 2305 #define CONFIG_SYS_I2C_NOPROBES {{0,0x50},{0,0x68},{1,0x54}} 2306 2307 will skip addresses 0x50 and 0x68 on bus 0 and address 0x54 on bus 1 2308 2309 CONFIG_SYS_SPD_BUS_NUM 2310 2311 If defined, then this indicates the I2C bus number for DDR SPD. 2312 If not defined, then U-Boot assumes that SPD is on I2C bus 0. 2313 2314 CONFIG_SYS_RTC_BUS_NUM 2315 2316 If defined, then this indicates the I2C bus number for the RTC. 2317 If not defined, then U-Boot assumes that RTC is on I2C bus 0. 2318 2319 CONFIG_SOFT_I2C_READ_REPEATED_START 2320 2321 defining this will force the i2c_read() function in 2322 the soft_i2c driver to perform an I2C repeated start 2323 between writing the address pointer and reading the 2324 data. If this define is omitted the default behaviour 2325 of doing a stop-start sequence will be used. Most I2C 2326 devices can use either method, but some require one or 2327 the other. 2328 2329- SPI Support: CONFIG_SPI 2330 2331 Enables SPI driver (so far only tested with 2332 SPI EEPROM, also an instance works with Crystal A/D and 2333 D/As on the SACSng board) 2334 2335 CONFIG_SH_SPI 2336 2337 Enables the driver for SPI controller on SuperH. Currently 2338 only SH7757 is supported. 2339 2340 CONFIG_SOFT_SPI 2341 2342 Enables a software (bit-bang) SPI driver rather than 2343 using hardware support. This is a general purpose 2344 driver that only requires three general I/O port pins 2345 (two outputs, one input) to function. If this is 2346 defined, the board configuration must define several 2347 SPI configuration items (port pins to use, etc). For 2348 an example, see include/configs/sacsng.h. 2349 2350 CONFIG_HARD_SPI 2351 2352 Enables a hardware SPI driver for general-purpose reads 2353 and writes. As with CONFIG_SOFT_SPI, the board configuration 2354 must define a list of chip-select function pointers. 2355 Currently supported on some MPC8xxx processors. For an 2356 example, see include/configs/mpc8349emds.h. 2357 2358 CONFIG_MXC_SPI 2359 2360 Enables the driver for the SPI controllers on i.MX and MXC 2361 SoCs. Currently i.MX31/35/51 are supported. 2362 2363 CONFIG_SYS_SPI_MXC_WAIT 2364 Timeout for waiting until spi transfer completed. 2365 default: (CONFIG_SYS_HZ/100) /* 10 ms */ 2366 2367- FPGA Support: CONFIG_FPGA 2368 2369 Enables FPGA subsystem. 2370 2371 CONFIG_FPGA_<vendor> 2372 2373 Enables support for specific chip vendors. 2374 (ALTERA, XILINX) 2375 2376 CONFIG_FPGA_<family> 2377 2378 Enables support for FPGA family. 2379 (SPARTAN2, SPARTAN3, VIRTEX2, CYCLONE2, ACEX1K, ACEX) 2380 2381 CONFIG_FPGA_COUNT 2382 2383 Specify the number of FPGA devices to support. 2384 2385 CONFIG_SYS_FPGA_PROG_FEEDBACK 2386 2387 Enable printing of hash marks during FPGA configuration. 2388 2389 CONFIG_SYS_FPGA_CHECK_BUSY 2390 2391 Enable checks on FPGA configuration interface busy 2392 status by the configuration function. This option 2393 will require a board or device specific function to 2394 be written. 2395 2396 CONFIG_FPGA_DELAY 2397 2398 If defined, a function that provides delays in the FPGA 2399 configuration driver. 2400 2401 CONFIG_SYS_FPGA_CHECK_CTRLC 2402 Allow Control-C to interrupt FPGA configuration 2403 2404 CONFIG_SYS_FPGA_CHECK_ERROR 2405 2406 Check for configuration errors during FPGA bitfile 2407 loading. For example, abort during Virtex II 2408 configuration if the INIT_B line goes low (which 2409 indicated a CRC error). 2410 2411 CONFIG_SYS_FPGA_WAIT_INIT 2412 2413 Maximum time to wait for the INIT_B line to de-assert 2414 after PROB_B has been de-asserted during a Virtex II 2415 FPGA configuration sequence. The default time is 500 2416 ms. 2417 2418 CONFIG_SYS_FPGA_WAIT_BUSY 2419 2420 Maximum time to wait for BUSY to de-assert during 2421 Virtex II FPGA configuration. The default is 5 ms. 2422 2423 CONFIG_SYS_FPGA_WAIT_CONFIG 2424 2425 Time to wait after FPGA configuration. The default is 2426 200 ms. 2427 2428- Configuration Management: 2429 CONFIG_BUILD_TARGET 2430 2431 Some SoCs need special image types (e.g. U-Boot binary 2432 with a special header) as build targets. By defining 2433 CONFIG_BUILD_TARGET in the SoC / board header, this 2434 special image will be automatically built upon calling 2435 make / buildman. 2436 2437 CONFIG_IDENT_STRING 2438 2439 If defined, this string will be added to the U-Boot 2440 version information (U_BOOT_VERSION) 2441 2442- Vendor Parameter Protection: 2443 2444 U-Boot considers the values of the environment 2445 variables "serial#" (Board Serial Number) and 2446 "ethaddr" (Ethernet Address) to be parameters that 2447 are set once by the board vendor / manufacturer, and 2448 protects these variables from casual modification by 2449 the user. Once set, these variables are read-only, 2450 and write or delete attempts are rejected. You can 2451 change this behaviour: 2452 2453 If CONFIG_ENV_OVERWRITE is #defined in your config 2454 file, the write protection for vendor parameters is 2455 completely disabled. Anybody can change or delete 2456 these parameters. 2457 2458 Alternatively, if you define _both_ an ethaddr in the 2459 default env _and_ CONFIG_OVERWRITE_ETHADDR_ONCE, a default 2460 Ethernet address is installed in the environment, 2461 which can be changed exactly ONCE by the user. [The 2462 serial# is unaffected by this, i. e. it remains 2463 read-only.] 2464 2465 The same can be accomplished in a more flexible way 2466 for any variable by configuring the type of access 2467 to allow for those variables in the ".flags" variable 2468 or define CONFIG_ENV_FLAGS_LIST_STATIC. 2469 2470- Protected RAM: 2471 CONFIG_PRAM 2472 2473 Define this variable to enable the reservation of 2474 "protected RAM", i. e. RAM which is not overwritten 2475 by U-Boot. Define CONFIG_PRAM to hold the number of 2476 kB you want to reserve for pRAM. You can overwrite 2477 this default value by defining an environment 2478 variable "pram" to the number of kB you want to 2479 reserve. Note that the board info structure will 2480 still show the full amount of RAM. If pRAM is 2481 reserved, a new environment variable "mem" will 2482 automatically be defined to hold the amount of 2483 remaining RAM in a form that can be passed as boot 2484 argument to Linux, for instance like that: 2485 2486 setenv bootargs ... mem=\${mem} 2487 saveenv 2488 2489 This way you can tell Linux not to use this memory, 2490 either, which results in a memory region that will 2491 not be affected by reboots. 2492 2493 *WARNING* If your board configuration uses automatic 2494 detection of the RAM size, you must make sure that 2495 this memory test is non-destructive. So far, the 2496 following board configurations are known to be 2497 "pRAM-clean": 2498 2499 IVMS8, IVML24, SPD8xx, TQM8xxL, 2500 HERMES, IP860, RPXlite, LWMON, 2501 FLAGADM, TQM8260 2502 2503- Access to physical memory region (> 4GB) 2504 Some basic support is provided for operations on memory not 2505 normally accessible to U-Boot - e.g. some architectures 2506 support access to more than 4GB of memory on 32-bit 2507 machines using physical address extension or similar. 2508 Define CONFIG_PHYSMEM to access this basic support, which 2509 currently only supports clearing the memory. 2510 2511- Error Recovery: 2512 CONFIG_PANIC_HANG 2513 2514 Define this variable to stop the system in case of a 2515 fatal error, so that you have to reset it manually. 2516 This is probably NOT a good idea for an embedded 2517 system where you want the system to reboot 2518 automatically as fast as possible, but it may be 2519 useful during development since you can try to debug 2520 the conditions that lead to the situation. 2521 2522 CONFIG_NET_RETRY_COUNT 2523 2524 This variable defines the number of retries for 2525 network operations like ARP, RARP, TFTP, or BOOTP 2526 before giving up the operation. If not defined, a 2527 default value of 5 is used. 2528 2529 CONFIG_ARP_TIMEOUT 2530 2531 Timeout waiting for an ARP reply in milliseconds. 2532 2533 CONFIG_NFS_TIMEOUT 2534 2535 Timeout in milliseconds used in NFS protocol. 2536 If you encounter "ERROR: Cannot umount" in nfs command, 2537 try longer timeout such as 2538 #define CONFIG_NFS_TIMEOUT 10000UL 2539 2540- Command Interpreter: 2541 CONFIG_AUTO_COMPLETE 2542 2543 Enable auto completion of commands using TAB. 2544 2545 CONFIG_SYS_PROMPT_HUSH_PS2 2546 2547 This defines the secondary prompt string, which is 2548 printed when the command interpreter needs more input 2549 to complete a command. Usually "> ". 2550 2551 Note: 2552 2553 In the current implementation, the local variables 2554 space and global environment variables space are 2555 separated. Local variables are those you define by 2556 simply typing `name=value'. To access a local 2557 variable later on, you have write `$name' or 2558 `${name}'; to execute the contents of a variable 2559 directly type `$name' at the command prompt. 2560 2561 Global environment variables are those you use 2562 setenv/printenv to work with. To run a command stored 2563 in such a variable, you need to use the run command, 2564 and you must not use the '$' sign to access them. 2565 2566 To store commands and special characters in a 2567 variable, please use double quotation marks 2568 surrounding the whole text of the variable, instead 2569 of the backslashes before semicolons and special 2570 symbols. 2571 2572- Command Line Editing and History: 2573 CONFIG_CMDLINE_EDITING 2574 2575 Enable editing and History functions for interactive 2576 command line input operations 2577 2578- Command Line PS1/PS2 support: 2579 CONFIG_CMDLINE_PS_SUPPORT 2580 2581 Enable support for changing the command prompt string 2582 at run-time. Only static string is supported so far. 2583 The string is obtained from environment variables PS1 2584 and PS2. 2585 2586- Default Environment: 2587 CONFIG_EXTRA_ENV_SETTINGS 2588 2589 Define this to contain any number of null terminated 2590 strings (variable = value pairs) that will be part of 2591 the default environment compiled into the boot image. 2592 2593 For example, place something like this in your 2594 board's config file: 2595 2596 #define CONFIG_EXTRA_ENV_SETTINGS \ 2597 "myvar1=value1\0" \ 2598 "myvar2=value2\0" 2599 2600 Warning: This method is based on knowledge about the 2601 internal format how the environment is stored by the 2602 U-Boot code. This is NOT an official, exported 2603 interface! Although it is unlikely that this format 2604 will change soon, there is no guarantee either. 2605 You better know what you are doing here. 2606 2607 Note: overly (ab)use of the default environment is 2608 discouraged. Make sure to check other ways to preset 2609 the environment like the "source" command or the 2610 boot command first. 2611 2612 CONFIG_ENV_VARS_UBOOT_CONFIG 2613 2614 Define this in order to add variables describing the 2615 U-Boot build configuration to the default environment. 2616 These will be named arch, cpu, board, vendor, and soc. 2617 2618 Enabling this option will cause the following to be defined: 2619 2620 - CONFIG_SYS_ARCH 2621 - CONFIG_SYS_CPU 2622 - CONFIG_SYS_BOARD 2623 - CONFIG_SYS_VENDOR 2624 - CONFIG_SYS_SOC 2625 2626 CONFIG_ENV_VARS_UBOOT_RUNTIME_CONFIG 2627 2628 Define this in order to add variables describing certain 2629 run-time determined information about the hardware to the 2630 environment. These will be named board_name, board_rev. 2631 2632 CONFIG_DELAY_ENVIRONMENT 2633 2634 Normally the environment is loaded when the board is 2635 initialised so that it is available to U-Boot. This inhibits 2636 that so that the environment is not available until 2637 explicitly loaded later by U-Boot code. With CONFIG_OF_CONTROL 2638 this is instead controlled by the value of 2639 /config/load-environment. 2640 2641- DataFlash Support: 2642 CONFIG_HAS_DATAFLASH 2643 2644 Defining this option enables DataFlash features and 2645 allows to read/write in Dataflash via the standard 2646 commands cp, md... 2647 2648- Serial Flash support 2649 CONFIG_CMD_SF 2650 2651 Defining this option enables SPI flash commands 2652 'sf probe/read/write/erase/update'. 2653 2654 Usage requires an initial 'probe' to define the serial 2655 flash parameters, followed by read/write/erase/update 2656 commands. 2657 2658 The following defaults may be provided by the platform 2659 to handle the common case when only a single serial 2660 flash is present on the system. 2661 2662 CONFIG_SF_DEFAULT_BUS Bus identifier 2663 CONFIG_SF_DEFAULT_CS Chip-select 2664 CONFIG_SF_DEFAULT_MODE (see include/spi.h) 2665 CONFIG_SF_DEFAULT_SPEED in Hz 2666 2667 CONFIG_CMD_SF_TEST 2668 2669 Define this option to include a destructive SPI flash 2670 test ('sf test'). 2671 2672 CONFIG_SF_DUAL_FLASH Dual flash memories 2673 2674 Define this option to use dual flash support where two flash 2675 memories can be connected with a given cs line. 2676 Currently Xilinx Zynq qspi supports these type of connections. 2677 2678- SystemACE Support: 2679 CONFIG_SYSTEMACE 2680 2681 Adding this option adds support for Xilinx SystemACE 2682 chips attached via some sort of local bus. The address 2683 of the chip must also be defined in the 2684 CONFIG_SYS_SYSTEMACE_BASE macro. For example: 2685 2686 #define CONFIG_SYSTEMACE 2687 #define CONFIG_SYS_SYSTEMACE_BASE 0xf0000000 2688 2689 When SystemACE support is added, the "ace" device type 2690 becomes available to the fat commands, i.e. fatls. 2691 2692- TFTP Fixed UDP Port: 2693 CONFIG_TFTP_PORT 2694 2695 If this is defined, the environment variable tftpsrcp 2696 is used to supply the TFTP UDP source port value. 2697 If tftpsrcp isn't defined, the normal pseudo-random port 2698 number generator is used. 2699 2700 Also, the environment variable tftpdstp is used to supply 2701 the TFTP UDP destination port value. If tftpdstp isn't 2702 defined, the normal port 69 is used. 2703 2704 The purpose for tftpsrcp is to allow a TFTP server to 2705 blindly start the TFTP transfer using the pre-configured 2706 target IP address and UDP port. This has the effect of 2707 "punching through" the (Windows XP) firewall, allowing 2708 the remainder of the TFTP transfer to proceed normally. 2709 A better solution is to properly configure the firewall, 2710 but sometimes that is not allowed. 2711 2712- Hashing support: 2713 CONFIG_CMD_HASH 2714 2715 This enables a generic 'hash' command which can produce 2716 hashes / digests from a few algorithms (e.g. SHA1, SHA256). 2717 2718 CONFIG_HASH_VERIFY 2719 2720 Enable the hash verify command (hash -v). This adds to code 2721 size a little. 2722 2723 Note: There is also a sha1sum command, which should perhaps 2724 be deprecated in favour of 'hash sha1'. 2725 2726- Freescale i.MX specific commands: 2727 CONFIG_CMD_HDMIDETECT 2728 This enables 'hdmidet' command which returns true if an 2729 HDMI monitor is detected. This command is i.MX 6 specific. 2730 2731- bootcount support: 2732 CONFIG_BOOTCOUNT_LIMIT 2733 2734 This enables the bootcounter support, see: 2735 http://www.denx.de/wiki/DULG/UBootBootCountLimit 2736 2737 CONFIG_AT91SAM9XE 2738 enable special bootcounter support on at91sam9xe based boards. 2739 CONFIG_SOC_DA8XX 2740 enable special bootcounter support on da850 based boards. 2741 CONFIG_BOOTCOUNT_RAM 2742 enable support for the bootcounter in RAM 2743 CONFIG_BOOTCOUNT_I2C 2744 enable support for the bootcounter on an i2c (like RTC) device. 2745 CONFIG_SYS_I2C_RTC_ADDR = i2c chip address 2746 CONFIG_SYS_BOOTCOUNT_ADDR = i2c addr which is used for 2747 the bootcounter. 2748 CONFIG_BOOTCOUNT_ALEN = address len 2749 2750- Show boot progress: 2751 CONFIG_SHOW_BOOT_PROGRESS 2752 2753 Defining this option allows to add some board- 2754 specific code (calling a user-provided function 2755 "show_boot_progress(int)") that enables you to show 2756 the system's boot progress on some display (for 2757 example, some LED's) on your board. At the moment, 2758 the following checkpoints are implemented: 2759 2760 2761Legacy uImage format: 2762 2763 Arg Where When 2764 1 common/cmd_bootm.c before attempting to boot an image 2765 -1 common/cmd_bootm.c Image header has bad magic number 2766 2 common/cmd_bootm.c Image header has correct magic number 2767 -2 common/cmd_bootm.c Image header has bad checksum 2768 3 common/cmd_bootm.c Image header has correct checksum 2769 -3 common/cmd_bootm.c Image data has bad checksum 2770 4 common/cmd_bootm.c Image data has correct checksum 2771 -4 common/cmd_bootm.c Image is for unsupported architecture 2772 5 common/cmd_bootm.c Architecture check OK 2773 -5 common/cmd_bootm.c Wrong Image Type (not kernel, multi) 2774 6 common/cmd_bootm.c Image Type check OK 2775 -6 common/cmd_bootm.c gunzip uncompression error 2776 -7 common/cmd_bootm.c Unimplemented compression type 2777 7 common/cmd_bootm.c Uncompression OK 2778 8 common/cmd_bootm.c No uncompress/copy overwrite error 2779 -9 common/cmd_bootm.c Unsupported OS (not Linux, BSD, VxWorks, QNX) 2780 2781 9 common/image.c Start initial ramdisk verification 2782 -10 common/image.c Ramdisk header has bad magic number 2783 -11 common/image.c Ramdisk header has bad checksum 2784 10 common/image.c Ramdisk header is OK 2785 -12 common/image.c Ramdisk data has bad checksum 2786 11 common/image.c Ramdisk data has correct checksum 2787 12 common/image.c Ramdisk verification complete, start loading 2788 -13 common/image.c Wrong Image Type (not PPC Linux ramdisk) 2789 13 common/image.c Start multifile image verification 2790 14 common/image.c No initial ramdisk, no multifile, continue. 2791 2792 15 arch/<arch>/lib/bootm.c All preparation done, transferring control to OS 2793 2794 -30 arch/powerpc/lib/board.c Fatal error, hang the system 2795 -31 post/post.c POST test failed, detected by post_output_backlog() 2796 -32 post/post.c POST test failed, detected by post_run_single() 2797 2798 34 common/cmd_doc.c before loading a Image from a DOC device 2799 -35 common/cmd_doc.c Bad usage of "doc" command 2800 35 common/cmd_doc.c correct usage of "doc" command 2801 -36 common/cmd_doc.c No boot device 2802 36 common/cmd_doc.c correct boot device 2803 -37 common/cmd_doc.c Unknown Chip ID on boot device 2804 37 common/cmd_doc.c correct chip ID found, device available 2805 -38 common/cmd_doc.c Read Error on boot device 2806 38 common/cmd_doc.c reading Image header from DOC device OK 2807 -39 common/cmd_doc.c Image header has bad magic number 2808 39 common/cmd_doc.c Image header has correct magic number 2809 -40 common/cmd_doc.c Error reading Image from DOC device 2810 40 common/cmd_doc.c Image header has correct magic number 2811 41 common/cmd_ide.c before loading a Image from a IDE device 2812 -42 common/cmd_ide.c Bad usage of "ide" command 2813 42 common/cmd_ide.c correct usage of "ide" command 2814 -43 common/cmd_ide.c No boot device 2815 43 common/cmd_ide.c boot device found 2816 -44 common/cmd_ide.c Device not available 2817 44 common/cmd_ide.c Device available 2818 -45 common/cmd_ide.c wrong partition selected 2819 45 common/cmd_ide.c partition selected 2820 -46 common/cmd_ide.c Unknown partition table 2821 46 common/cmd_ide.c valid partition table found 2822 -47 common/cmd_ide.c Invalid partition type 2823 47 common/cmd_ide.c correct partition type 2824 -48 common/cmd_ide.c Error reading Image Header on boot device 2825 48 common/cmd_ide.c reading Image Header from IDE device OK 2826 -49 common/cmd_ide.c Image header has bad magic number 2827 49 common/cmd_ide.c Image header has correct magic number 2828 -50 common/cmd_ide.c Image header has bad checksum 2829 50 common/cmd_ide.c Image header has correct checksum 2830 -51 common/cmd_ide.c Error reading Image from IDE device 2831 51 common/cmd_ide.c reading Image from IDE device OK 2832 52 common/cmd_nand.c before loading a Image from a NAND device 2833 -53 common/cmd_nand.c Bad usage of "nand" command 2834 53 common/cmd_nand.c correct usage of "nand" command 2835 -54 common/cmd_nand.c No boot device 2836 54 common/cmd_nand.c boot device found 2837 -55 common/cmd_nand.c Unknown Chip ID on boot device 2838 55 common/cmd_nand.c correct chip ID found, device available 2839 -56 common/cmd_nand.c Error reading Image Header on boot device 2840 56 common/cmd_nand.c reading Image Header from NAND device OK 2841 -57 common/cmd_nand.c Image header has bad magic number 2842 57 common/cmd_nand.c Image header has correct magic number 2843 -58 common/cmd_nand.c Error reading Image from NAND device 2844 58 common/cmd_nand.c reading Image from NAND device OK 2845 2846 -60 common/env_common.c Environment has a bad CRC, using default 2847 2848 64 net/eth.c starting with Ethernet configuration. 2849 -64 net/eth.c no Ethernet found. 2850 65 net/eth.c Ethernet found. 2851 2852 -80 common/cmd_net.c usage wrong 2853 80 common/cmd_net.c before calling net_loop() 2854 -81 common/cmd_net.c some error in net_loop() occurred 2855 81 common/cmd_net.c net_loop() back without error 2856 -82 common/cmd_net.c size == 0 (File with size 0 loaded) 2857 82 common/cmd_net.c trying automatic boot 2858 83 common/cmd_net.c running "source" command 2859 -83 common/cmd_net.c some error in automatic boot or "source" command 2860 84 common/cmd_net.c end without errors 2861 2862FIT uImage format: 2863 2864 Arg Where When 2865 100 common/cmd_bootm.c Kernel FIT Image has correct format 2866 -100 common/cmd_bootm.c Kernel FIT Image has incorrect format 2867 101 common/cmd_bootm.c No Kernel subimage unit name, using configuration 2868 -101 common/cmd_bootm.c Can't get configuration for kernel subimage 2869 102 common/cmd_bootm.c Kernel unit name specified 2870 -103 common/cmd_bootm.c Can't get kernel subimage node offset 2871 103 common/cmd_bootm.c Found configuration node 2872 104 common/cmd_bootm.c Got kernel subimage node offset 2873 -104 common/cmd_bootm.c Kernel subimage hash verification failed 2874 105 common/cmd_bootm.c Kernel subimage hash verification OK 2875 -105 common/cmd_bootm.c Kernel subimage is for unsupported architecture 2876 106 common/cmd_bootm.c Architecture check OK 2877 -106 common/cmd_bootm.c Kernel subimage has wrong type 2878 107 common/cmd_bootm.c Kernel subimage type OK 2879 -107 common/cmd_bootm.c Can't get kernel subimage data/size 2880 108 common/cmd_bootm.c Got kernel subimage data/size 2881 -108 common/cmd_bootm.c Wrong image type (not legacy, FIT) 2882 -109 common/cmd_bootm.c Can't get kernel subimage type 2883 -110 common/cmd_bootm.c Can't get kernel subimage comp 2884 -111 common/cmd_bootm.c Can't get kernel subimage os 2885 -112 common/cmd_bootm.c Can't get kernel subimage load address 2886 -113 common/cmd_bootm.c Image uncompress/copy overwrite error 2887 2888 120 common/image.c Start initial ramdisk verification 2889 -120 common/image.c Ramdisk FIT image has incorrect format 2890 121 common/image.c Ramdisk FIT image has correct format 2891 122 common/image.c No ramdisk subimage unit name, using configuration 2892 -122 common/image.c Can't get configuration for ramdisk subimage 2893 123 common/image.c Ramdisk unit name specified 2894 -124 common/image.c Can't get ramdisk subimage node offset 2895 125 common/image.c Got ramdisk subimage node offset 2896 -125 common/image.c Ramdisk subimage hash verification failed 2897 126 common/image.c Ramdisk subimage hash verification OK 2898 -126 common/image.c Ramdisk subimage for unsupported architecture 2899 127 common/image.c Architecture check OK 2900 -127 common/image.c Can't get ramdisk subimage data/size 2901 128 common/image.c Got ramdisk subimage data/size 2902 129 common/image.c Can't get ramdisk load address 2903 -129 common/image.c Got ramdisk load address 2904 2905 -130 common/cmd_doc.c Incorrect FIT image format 2906 131 common/cmd_doc.c FIT image format OK 2907 2908 -140 common/cmd_ide.c Incorrect FIT image format 2909 141 common/cmd_ide.c FIT image format OK 2910 2911 -150 common/cmd_nand.c Incorrect FIT image format 2912 151 common/cmd_nand.c FIT image format OK 2913 2914- legacy image format: 2915 CONFIG_IMAGE_FORMAT_LEGACY 2916 enables the legacy image format support in U-Boot. 2917 2918 Default: 2919 enabled if CONFIG_FIT_SIGNATURE is not defined. 2920 2921 CONFIG_DISABLE_IMAGE_LEGACY 2922 disable the legacy image format 2923 2924 This define is introduced, as the legacy image format is 2925 enabled per default for backward compatibility. 2926 2927- Standalone program support: 2928 CONFIG_STANDALONE_LOAD_ADDR 2929 2930 This option defines a board specific value for the 2931 address where standalone program gets loaded, thus 2932 overwriting the architecture dependent default 2933 settings. 2934 2935- Frame Buffer Address: 2936 CONFIG_FB_ADDR 2937 2938 Define CONFIG_FB_ADDR if you want to use specific 2939 address for frame buffer. This is typically the case 2940 when using a graphics controller has separate video 2941 memory. U-Boot will then place the frame buffer at 2942 the given address instead of dynamically reserving it 2943 in system RAM by calling lcd_setmem(), which grabs 2944 the memory for the frame buffer depending on the 2945 configured panel size. 2946 2947 Please see board_init_f function. 2948 2949- Automatic software updates via TFTP server 2950 CONFIG_UPDATE_TFTP 2951 CONFIG_UPDATE_TFTP_CNT_MAX 2952 CONFIG_UPDATE_TFTP_MSEC_MAX 2953 2954 These options enable and control the auto-update feature; 2955 for a more detailed description refer to doc/README.update. 2956 2957- MTD Support (mtdparts command, UBI support) 2958 CONFIG_MTD_DEVICE 2959 2960 Adds the MTD device infrastructure from the Linux kernel. 2961 Needed for mtdparts command support. 2962 2963 CONFIG_MTD_PARTITIONS 2964 2965 Adds the MTD partitioning infrastructure from the Linux 2966 kernel. Needed for UBI support. 2967 2968- UBI support 2969 CONFIG_CMD_UBI 2970 2971 Adds commands for interacting with MTD partitions formatted 2972 with the UBI flash translation layer 2973 2974 Requires also defining CONFIG_RBTREE 2975 2976 CONFIG_UBI_SILENCE_MSG 2977 2978 Make the verbose messages from UBI stop printing. This leaves 2979 warnings and errors enabled. 2980 2981 2982 CONFIG_MTD_UBI_WL_THRESHOLD 2983 This parameter defines the maximum difference between the highest 2984 erase counter value and the lowest erase counter value of eraseblocks 2985 of UBI devices. When this threshold is exceeded, UBI starts performing 2986 wear leveling by means of moving data from eraseblock with low erase 2987 counter to eraseblocks with high erase counter. 2988 2989 The default value should be OK for SLC NAND flashes, NOR flashes and 2990 other flashes which have eraseblock life-cycle 100000 or more. 2991 However, in case of MLC NAND flashes which typically have eraseblock 2992 life-cycle less than 10000, the threshold should be lessened (e.g., 2993 to 128 or 256, although it does not have to be power of 2). 2994 2995 default: 4096 2996 2997 CONFIG_MTD_UBI_BEB_LIMIT 2998 This option specifies the maximum bad physical eraseblocks UBI 2999 expects on the MTD device (per 1024 eraseblocks). If the 3000 underlying flash does not admit of bad eraseblocks (e.g. NOR 3001 flash), this value is ignored. 3002 3003 NAND datasheets often specify the minimum and maximum NVM 3004 (Number of Valid Blocks) for the flashes' endurance lifetime. 3005 The maximum expected bad eraseblocks per 1024 eraseblocks 3006 then can be calculated as "1024 * (1 - MinNVB / MaxNVB)", 3007 which gives 20 for most NANDs (MaxNVB is basically the total 3008 count of eraseblocks on the chip). 3009 3010 To put it differently, if this value is 20, UBI will try to 3011 reserve about 1.9% of physical eraseblocks for bad blocks 3012 handling. And that will be 1.9% of eraseblocks on the entire 3013 NAND chip, not just the MTD partition UBI attaches. This means 3014 that if you have, say, a NAND flash chip admits maximum 40 bad 3015 eraseblocks, and it is split on two MTD partitions of the same 3016 size, UBI will reserve 40 eraseblocks when attaching a 3017 partition. 3018 3019 default: 20 3020 3021 CONFIG_MTD_UBI_FASTMAP 3022 Fastmap is a mechanism which allows attaching an UBI device 3023 in nearly constant time. Instead of scanning the whole MTD device it 3024 only has to locate a checkpoint (called fastmap) on the device. 3025 The on-flash fastmap contains all information needed to attach 3026 the device. Using fastmap makes only sense on large devices where 3027 attaching by scanning takes long. UBI will not automatically install 3028 a fastmap on old images, but you can set the UBI parameter 3029 CONFIG_MTD_UBI_FASTMAP_AUTOCONVERT to 1 if you want so. Please note 3030 that fastmap-enabled images are still usable with UBI implementations 3031 without fastmap support. On typical flash devices the whole fastmap 3032 fits into one PEB. UBI will reserve PEBs to hold two fastmaps. 3033 3034 CONFIG_MTD_UBI_FASTMAP_AUTOCONVERT 3035 Set this parameter to enable fastmap automatically on images 3036 without a fastmap. 3037 default: 0 3038 3039 CONFIG_MTD_UBI_FM_DEBUG 3040 Enable UBI fastmap debug 3041 default: 0 3042 3043- UBIFS support 3044 CONFIG_CMD_UBIFS 3045 3046 Adds commands for interacting with UBI volumes formatted as 3047 UBIFS. UBIFS is read-only in u-boot. 3048 3049 Requires UBI support as well as CONFIG_LZO 3050 3051 CONFIG_UBIFS_SILENCE_MSG 3052 3053 Make the verbose messages from UBIFS stop printing. This leaves 3054 warnings and errors enabled. 3055 3056- SPL framework 3057 CONFIG_SPL 3058 Enable building of SPL globally. 3059 3060 CONFIG_SPL_LDSCRIPT 3061 LDSCRIPT for linking the SPL binary. 3062 3063 CONFIG_SPL_MAX_FOOTPRINT 3064 Maximum size in memory allocated to the SPL, BSS included. 3065 When defined, the linker checks that the actual memory 3066 used by SPL from _start to __bss_end does not exceed it. 3067 CONFIG_SPL_MAX_FOOTPRINT and CONFIG_SPL_BSS_MAX_SIZE 3068 must not be both defined at the same time. 3069 3070 CONFIG_SPL_MAX_SIZE 3071 Maximum size of the SPL image (text, data, rodata, and 3072 linker lists sections), BSS excluded. 3073 When defined, the linker checks that the actual size does 3074 not exceed it. 3075 3076 CONFIG_SPL_TEXT_BASE 3077 TEXT_BASE for linking the SPL binary. 3078 3079 CONFIG_SPL_RELOC_TEXT_BASE 3080 Address to relocate to. If unspecified, this is equal to 3081 CONFIG_SPL_TEXT_BASE (i.e. no relocation is done). 3082 3083 CONFIG_SPL_BSS_START_ADDR 3084 Link address for the BSS within the SPL binary. 3085 3086 CONFIG_SPL_BSS_MAX_SIZE 3087 Maximum size in memory allocated to the SPL BSS. 3088 When defined, the linker checks that the actual memory used 3089 by SPL from __bss_start to __bss_end does not exceed it. 3090 CONFIG_SPL_MAX_FOOTPRINT and CONFIG_SPL_BSS_MAX_SIZE 3091 must not be both defined at the same time. 3092 3093 CONFIG_SPL_STACK 3094 Adress of the start of the stack SPL will use 3095 3096 CONFIG_SPL_PANIC_ON_RAW_IMAGE 3097 When defined, SPL will panic() if the image it has 3098 loaded does not have a signature. 3099 Defining this is useful when code which loads images 3100 in SPL cannot guarantee that absolutely all read errors 3101 will be caught. 3102 An example is the LPC32XX MLC NAND driver, which will 3103 consider that a completely unreadable NAND block is bad, 3104 and thus should be skipped silently. 3105 3106 CONFIG_SPL_RELOC_STACK 3107 Adress of the start of the stack SPL will use after 3108 relocation. If unspecified, this is equal to 3109 CONFIG_SPL_STACK. 3110 3111 CONFIG_SYS_SPL_MALLOC_START 3112 Starting address of the malloc pool used in SPL. 3113 When this option is set the full malloc is used in SPL and 3114 it is set up by spl_init() and before that, the simple malloc() 3115 can be used if CONFIG_SYS_MALLOC_F is defined. 3116 3117 CONFIG_SYS_SPL_MALLOC_SIZE 3118 The size of the malloc pool used in SPL. 3119 3120 CONFIG_SPL_FRAMEWORK 3121 Enable the SPL framework under common/. This framework 3122 supports MMC, NAND and YMODEM loading of U-Boot and NAND 3123 NAND loading of the Linux Kernel. 3124 3125 CONFIG_SPL_OS_BOOT 3126 Enable booting directly to an OS from SPL. 3127 See also: doc/README.falcon 3128 3129 CONFIG_SPL_DISPLAY_PRINT 3130 For ARM, enable an optional function to print more information 3131 about the running system. 3132 3133 CONFIG_SPL_INIT_MINIMAL 3134 Arch init code should be built for a very small image 3135 3136 CONFIG_SYS_MMCSD_RAW_MODE_U_BOOT_PARTITION 3137 Partition on the MMC to load U-Boot from when the MMC is being 3138 used in raw mode 3139 3140 CONFIG_SYS_MMCSD_RAW_MODE_KERNEL_SECTOR 3141 Sector to load kernel uImage from when MMC is being 3142 used in raw mode (for Falcon mode) 3143 3144 CONFIG_SYS_MMCSD_RAW_MODE_ARGS_SECTOR, 3145 CONFIG_SYS_MMCSD_RAW_MODE_ARGS_SECTORS 3146 Sector and number of sectors to load kernel argument 3147 parameters from when MMC is being used in raw mode 3148 (for falcon mode) 3149 3150 CONFIG_SYS_MMCSD_FS_BOOT_PARTITION 3151 Partition on the MMC to load U-Boot from when the MMC is being 3152 used in fs mode 3153 3154 CONFIG_SPL_FS_LOAD_PAYLOAD_NAME 3155 Filename to read to load U-Boot when reading from filesystem 3156 3157 CONFIG_SPL_FS_LOAD_KERNEL_NAME 3158 Filename to read to load kernel uImage when reading 3159 from filesystem (for Falcon mode) 3160 3161 CONFIG_SPL_FS_LOAD_ARGS_NAME 3162 Filename to read to load kernel argument parameters 3163 when reading from filesystem (for Falcon mode) 3164 3165 CONFIG_SPL_MPC83XX_WAIT_FOR_NAND 3166 Set this for NAND SPL on PPC mpc83xx targets, so that 3167 start.S waits for the rest of the SPL to load before 3168 continuing (the hardware starts execution after just 3169 loading the first page rather than the full 4K). 3170 3171 CONFIG_SPL_SKIP_RELOCATE 3172 Avoid SPL relocation 3173 3174 CONFIG_SPL_NAND_BASE 3175 Include nand_base.c in the SPL. Requires 3176 CONFIG_SPL_NAND_DRIVERS. 3177 3178 CONFIG_SPL_NAND_DRIVERS 3179 SPL uses normal NAND drivers, not minimal drivers. 3180 3181 CONFIG_SPL_NAND_ECC 3182 Include standard software ECC in the SPL 3183 3184 CONFIG_SPL_NAND_SIMPLE 3185 Support for NAND boot using simple NAND drivers that 3186 expose the cmd_ctrl() interface. 3187 3188 CONFIG_SPL_UBI 3189 Support for a lightweight UBI (fastmap) scanner and 3190 loader 3191 3192 CONFIG_SPL_NAND_RAW_ONLY 3193 Support to boot only raw u-boot.bin images. Use this only 3194 if you need to save space. 3195 3196 CONFIG_SPL_COMMON_INIT_DDR 3197 Set for common ddr init with serial presence detect in 3198 SPL binary. 3199 3200 CONFIG_SYS_NAND_5_ADDR_CYCLE, CONFIG_SYS_NAND_PAGE_COUNT, 3201 CONFIG_SYS_NAND_PAGE_SIZE, CONFIG_SYS_NAND_OOBSIZE, 3202 CONFIG_SYS_NAND_BLOCK_SIZE, CONFIG_SYS_NAND_BAD_BLOCK_POS, 3203 CONFIG_SYS_NAND_ECCPOS, CONFIG_SYS_NAND_ECCSIZE, 3204 CONFIG_SYS_NAND_ECCBYTES 3205 Defines the size and behavior of the NAND that SPL uses 3206 to read U-Boot 3207 3208 CONFIG_SPL_NAND_BOOT 3209 Add support NAND boot 3210 3211 CONFIG_SYS_NAND_U_BOOT_OFFS 3212 Location in NAND to read U-Boot from 3213 3214 CONFIG_SYS_NAND_U_BOOT_DST 3215 Location in memory to load U-Boot to 3216 3217 CONFIG_SYS_NAND_U_BOOT_SIZE 3218 Size of image to load 3219 3220 CONFIG_SYS_NAND_U_BOOT_START 3221 Entry point in loaded image to jump to 3222 3223 CONFIG_SYS_NAND_HW_ECC_OOBFIRST 3224 Define this if you need to first read the OOB and then the 3225 data. This is used, for example, on davinci platforms. 3226 3227 CONFIG_SPL_OMAP3_ID_NAND 3228 Support for an OMAP3-specific set of functions to return the 3229 ID and MFR of the first attached NAND chip, if present. 3230 3231 CONFIG_SPL_RAM_DEVICE 3232 Support for running image already present in ram, in SPL binary 3233 3234 CONFIG_SPL_PAD_TO 3235 Image offset to which the SPL should be padded before appending 3236 the SPL payload. By default, this is defined as 3237 CONFIG_SPL_MAX_SIZE, or 0 if CONFIG_SPL_MAX_SIZE is undefined. 3238 CONFIG_SPL_PAD_TO must be either 0, meaning to append the SPL 3239 payload without any padding, or >= CONFIG_SPL_MAX_SIZE. 3240 3241 CONFIG_SPL_TARGET 3242 Final target image containing SPL and payload. Some SPLs 3243 use an arch-specific makefile fragment instead, for 3244 example if more than one image needs to be produced. 3245 3246 CONFIG_FIT_SPL_PRINT 3247 Printing information about a FIT image adds quite a bit of 3248 code to SPL. So this is normally disabled in SPL. Use this 3249 option to re-enable it. This will affect the output of the 3250 bootm command when booting a FIT image. 3251 3252- TPL framework 3253 CONFIG_TPL 3254 Enable building of TPL globally. 3255 3256 CONFIG_TPL_PAD_TO 3257 Image offset to which the TPL should be padded before appending 3258 the TPL payload. By default, this is defined as 3259 CONFIG_SPL_MAX_SIZE, or 0 if CONFIG_SPL_MAX_SIZE is undefined. 3260 CONFIG_SPL_PAD_TO must be either 0, meaning to append the SPL 3261 payload without any padding, or >= CONFIG_SPL_MAX_SIZE. 3262 3263- Interrupt support (PPC): 3264 3265 There are common interrupt_init() and timer_interrupt() 3266 for all PPC archs. interrupt_init() calls interrupt_init_cpu() 3267 for CPU specific initialization. interrupt_init_cpu() 3268 should set decrementer_count to appropriate value. If 3269 CPU resets decrementer automatically after interrupt 3270 (ppc4xx) it should set decrementer_count to zero. 3271 timer_interrupt() calls timer_interrupt_cpu() for CPU 3272 specific handling. If board has watchdog / status_led 3273 / other_activity_monitor it works automatically from 3274 general timer_interrupt(). 3275 3276 3277Board initialization settings: 3278------------------------------ 3279 3280During Initialization u-boot calls a number of board specific functions 3281to allow the preparation of board specific prerequisites, e.g. pin setup 3282before drivers are initialized. To enable these callbacks the 3283following configuration macros have to be defined. Currently this is 3284architecture specific, so please check arch/your_architecture/lib/board.c 3285typically in board_init_f() and board_init_r(). 3286 3287- CONFIG_BOARD_EARLY_INIT_F: Call board_early_init_f() 3288- CONFIG_BOARD_EARLY_INIT_R: Call board_early_init_r() 3289- CONFIG_BOARD_LATE_INIT: Call board_late_init() 3290- CONFIG_BOARD_POSTCLK_INIT: Call board_postclk_init() 3291 3292Configuration Settings: 3293----------------------- 3294 3295- CONFIG_SYS_SUPPORT_64BIT_DATA: Defined automatically if compiled as 64-bit. 3296 Optionally it can be defined to support 64-bit memory commands. 3297 3298- CONFIG_SYS_LONGHELP: Defined when you want long help messages included; 3299 undefine this when you're short of memory. 3300 3301- CONFIG_SYS_HELP_CMD_WIDTH: Defined when you want to override the default 3302 width of the commands listed in the 'help' command output. 3303 3304- CONFIG_SYS_PROMPT: This is what U-Boot prints on the console to 3305 prompt for user input. 3306 3307- CONFIG_SYS_CBSIZE: Buffer size for input from the Console 3308 3309- CONFIG_SYS_PBSIZE: Buffer size for Console output 3310 3311- CONFIG_SYS_MAXARGS: max. Number of arguments accepted for monitor commands 3312 3313- CONFIG_SYS_BARGSIZE: Buffer size for Boot Arguments which are passed to 3314 the application (usually a Linux kernel) when it is 3315 booted 3316 3317- CONFIG_SYS_BAUDRATE_TABLE: 3318 List of legal baudrate settings for this board. 3319 3320- CONFIG_SYS_MEMTEST_START, CONFIG_SYS_MEMTEST_END: 3321 Begin and End addresses of the area used by the 3322 simple memory test. 3323 3324- CONFIG_SYS_ALT_MEMTEST: 3325 Enable an alternate, more extensive memory test. 3326 3327- CONFIG_SYS_MEMTEST_SCRATCH: 3328 Scratch address used by the alternate memory test 3329 You only need to set this if address zero isn't writeable 3330 3331- CONFIG_SYS_MEM_RESERVE_SECURE 3332 Only implemented for ARMv8 for now. 3333 If defined, the size of CONFIG_SYS_MEM_RESERVE_SECURE memory 3334 is substracted from total RAM and won't be reported to OS. 3335 This memory can be used as secure memory. A variable 3336 gd->arch.secure_ram is used to track the location. In systems 3337 the RAM base is not zero, or RAM is divided into banks, 3338 this variable needs to be recalcuated to get the address. 3339 3340- CONFIG_SYS_MEM_TOP_HIDE: 3341 If CONFIG_SYS_MEM_TOP_HIDE is defined in the board config header, 3342 this specified memory area will get subtracted from the top 3343 (end) of RAM and won't get "touched" at all by U-Boot. By 3344 fixing up gd->ram_size the Linux kernel should gets passed 3345 the now "corrected" memory size and won't touch it either. 3346 This should work for arch/ppc and arch/powerpc. Only Linux 3347 board ports in arch/powerpc with bootwrapper support that 3348 recalculate the memory size from the SDRAM controller setup 3349 will have to get fixed in Linux additionally. 3350 3351 This option can be used as a workaround for the 440EPx/GRx 3352 CHIP 11 errata where the last 256 bytes in SDRAM shouldn't 3353 be touched. 3354 3355 WARNING: Please make sure that this value is a multiple of 3356 the Linux page size (normally 4k). If this is not the case, 3357 then the end address of the Linux memory will be located at a 3358 non page size aligned address and this could cause major 3359 problems. 3360 3361- CONFIG_SYS_LOADS_BAUD_CHANGE: 3362 Enable temporary baudrate change while serial download 3363 3364- CONFIG_SYS_SDRAM_BASE: 3365 Physical start address of SDRAM. _Must_ be 0 here. 3366 3367- CONFIG_SYS_FLASH_BASE: 3368 Physical start address of Flash memory. 3369 3370- CONFIG_SYS_MONITOR_BASE: 3371 Physical start address of boot monitor code (set by 3372 make config files to be same as the text base address 3373 (CONFIG_SYS_TEXT_BASE) used when linking) - same as 3374 CONFIG_SYS_FLASH_BASE when booting from flash. 3375 3376- CONFIG_SYS_MONITOR_LEN: 3377 Size of memory reserved for monitor code, used to 3378 determine _at_compile_time_ (!) if the environment is 3379 embedded within the U-Boot image, or in a separate 3380 flash sector. 3381 3382- CONFIG_SYS_MALLOC_LEN: 3383 Size of DRAM reserved for malloc() use. 3384 3385- CONFIG_SYS_MALLOC_F_LEN 3386 Size of the malloc() pool for use before relocation. If 3387 this is defined, then a very simple malloc() implementation 3388 will become available before relocation. The address is just 3389 below the global data, and the stack is moved down to make 3390 space. 3391 3392 This feature allocates regions with increasing addresses 3393 within the region. calloc() is supported, but realloc() 3394 is not available. free() is supported but does nothing. 3395 The memory will be freed (or in fact just forgotten) when 3396 U-Boot relocates itself. 3397 3398- CONFIG_SYS_MALLOC_SIMPLE 3399 Provides a simple and small malloc() and calloc() for those 3400 boards which do not use the full malloc in SPL (which is 3401 enabled with CONFIG_SYS_SPL_MALLOC_START). 3402 3403- CONFIG_SYS_NONCACHED_MEMORY: 3404 Size of non-cached memory area. This area of memory will be 3405 typically located right below the malloc() area and mapped 3406 uncached in the MMU. This is useful for drivers that would 3407 otherwise require a lot of explicit cache maintenance. For 3408 some drivers it's also impossible to properly maintain the 3409 cache. For example if the regions that need to be flushed 3410 are not a multiple of the cache-line size, *and* padding 3411 cannot be allocated between the regions to align them (i.e. 3412 if the HW requires a contiguous array of regions, and the 3413 size of each region is not cache-aligned), then a flush of 3414 one region may result in overwriting data that hardware has 3415 written to another region in the same cache-line. This can 3416 happen for example in network drivers where descriptors for 3417 buffers are typically smaller than the CPU cache-line (e.g. 3418 16 bytes vs. 32 or 64 bytes). 3419 3420 Non-cached memory is only supported on 32-bit ARM at present. 3421 3422- CONFIG_SYS_BOOTM_LEN: 3423 Normally compressed uImages are limited to an 3424 uncompressed size of 8 MBytes. If this is not enough, 3425 you can define CONFIG_SYS_BOOTM_LEN in your board config file 3426 to adjust this setting to your needs. 3427 3428- CONFIG_SYS_BOOTMAPSZ: 3429 Maximum size of memory mapped by the startup code of 3430 the Linux kernel; all data that must be processed by 3431 the Linux kernel (bd_info, boot arguments, FDT blob if 3432 used) must be put below this limit, unless "bootm_low" 3433 environment variable is defined and non-zero. In such case 3434 all data for the Linux kernel must be between "bootm_low" 3435 and "bootm_low" + CONFIG_SYS_BOOTMAPSZ. The environment 3436 variable "bootm_mapsize" will override the value of 3437 CONFIG_SYS_BOOTMAPSZ. If CONFIG_SYS_BOOTMAPSZ is undefined, 3438 then the value in "bootm_size" will be used instead. 3439 3440- CONFIG_SYS_BOOT_RAMDISK_HIGH: 3441 Enable initrd_high functionality. If defined then the 3442 initrd_high feature is enabled and the bootm ramdisk subcommand 3443 is enabled. 3444 3445- CONFIG_SYS_BOOT_GET_CMDLINE: 3446 Enables allocating and saving kernel cmdline in space between 3447 "bootm_low" and "bootm_low" + BOOTMAPSZ. 3448 3449- CONFIG_SYS_BOOT_GET_KBD: 3450 Enables allocating and saving a kernel copy of the bd_info in 3451 space between "bootm_low" and "bootm_low" + BOOTMAPSZ. 3452 3453- CONFIG_SYS_MAX_FLASH_BANKS: 3454 Max number of Flash memory banks 3455 3456- CONFIG_SYS_MAX_FLASH_SECT: 3457 Max number of sectors on a Flash chip 3458 3459- CONFIG_SYS_FLASH_ERASE_TOUT: 3460 Timeout for Flash erase operations (in ms) 3461 3462- CONFIG_SYS_FLASH_WRITE_TOUT: 3463 Timeout for Flash write operations (in ms) 3464 3465- CONFIG_SYS_FLASH_LOCK_TOUT 3466 Timeout for Flash set sector lock bit operation (in ms) 3467 3468- CONFIG_SYS_FLASH_UNLOCK_TOUT 3469 Timeout for Flash clear lock bits operation (in ms) 3470 3471- CONFIG_SYS_FLASH_PROTECTION 3472 If defined, hardware flash sectors protection is used 3473 instead of U-Boot software protection. 3474 3475- CONFIG_SYS_DIRECT_FLASH_TFTP: 3476 3477 Enable TFTP transfers directly to flash memory; 3478 without this option such a download has to be 3479 performed in two steps: (1) download to RAM, and (2) 3480 copy from RAM to flash. 3481 3482 The two-step approach is usually more reliable, since 3483 you can check if the download worked before you erase 3484 the flash, but in some situations (when system RAM is 3485 too limited to allow for a temporary copy of the 3486 downloaded image) this option may be very useful. 3487 3488- CONFIG_SYS_FLASH_CFI: 3489 Define if the flash driver uses extra elements in the 3490 common flash structure for storing flash geometry. 3491 3492- CONFIG_FLASH_CFI_DRIVER 3493 This option also enables the building of the cfi_flash driver 3494 in the drivers directory 3495 3496- CONFIG_FLASH_CFI_MTD 3497 This option enables the building of the cfi_mtd driver 3498 in the drivers directory. The driver exports CFI flash 3499 to the MTD layer. 3500 3501- CONFIG_SYS_FLASH_USE_BUFFER_WRITE 3502 Use buffered writes to flash. 3503 3504- CONFIG_FLASH_SPANSION_S29WS_N 3505 s29ws-n MirrorBit flash has non-standard addresses for buffered 3506 write commands. 3507 3508- CONFIG_SYS_FLASH_QUIET_TEST 3509 If this option is defined, the common CFI flash doesn't 3510 print it's warning upon not recognized FLASH banks. This 3511 is useful, if some of the configured banks are only 3512 optionally available. 3513 3514- CONFIG_FLASH_SHOW_PROGRESS 3515 If defined (must be an integer), print out countdown 3516 digits and dots. Recommended value: 45 (9..1) for 80 3517 column displays, 15 (3..1) for 40 column displays. 3518 3519- CONFIG_FLASH_VERIFY 3520 If defined, the content of the flash (destination) is compared 3521 against the source after the write operation. An error message 3522 will be printed when the contents are not identical. 3523 Please note that this option is useless in nearly all cases, 3524 since such flash programming errors usually are detected earlier 3525 while unprotecting/erasing/programming. Please only enable 3526 this option if you really know what you are doing. 3527 3528- CONFIG_SYS_RX_ETH_BUFFER: 3529 Defines the number of Ethernet receive buffers. On some 3530 Ethernet controllers it is recommended to set this value 3531 to 8 or even higher (EEPRO100 or 405 EMAC), since all 3532 buffers can be full shortly after enabling the interface 3533 on high Ethernet traffic. 3534 Defaults to 4 if not defined. 3535 3536- CONFIG_ENV_MAX_ENTRIES 3537 3538 Maximum number of entries in the hash table that is used 3539 internally to store the environment settings. The default 3540 setting is supposed to be generous and should work in most 3541 cases. This setting can be used to tune behaviour; see 3542 lib/hashtable.c for details. 3543 3544- CONFIG_ENV_FLAGS_LIST_DEFAULT 3545- CONFIG_ENV_FLAGS_LIST_STATIC 3546 Enable validation of the values given to environment variables when 3547 calling env set. Variables can be restricted to only decimal, 3548 hexadecimal, or boolean. If CONFIG_CMD_NET is also defined, 3549 the variables can also be restricted to IP address or MAC address. 3550 3551 The format of the list is: 3552 type_attribute = [s|d|x|b|i|m] 3553 access_attribute = [a|r|o|c] 3554 attributes = type_attribute[access_attribute] 3555 entry = variable_name[:attributes] 3556 list = entry[,list] 3557 3558 The type attributes are: 3559 s - String (default) 3560 d - Decimal 3561 x - Hexadecimal 3562 b - Boolean ([1yYtT|0nNfF]) 3563 i - IP address 3564 m - MAC address 3565 3566 The access attributes are: 3567 a - Any (default) 3568 r - Read-only 3569 o - Write-once 3570 c - Change-default 3571 3572 - CONFIG_ENV_FLAGS_LIST_DEFAULT 3573 Define this to a list (string) to define the ".flags" 3574 environment variable in the default or embedded environment. 3575 3576 - CONFIG_ENV_FLAGS_LIST_STATIC 3577 Define this to a list (string) to define validation that 3578 should be done if an entry is not found in the ".flags" 3579 environment variable. To override a setting in the static 3580 list, simply add an entry for the same variable name to the 3581 ".flags" variable. 3582 3583 If CONFIG_REGEX is defined, the variable_name above is evaluated as a 3584 regular expression. This allows multiple variables to define the same 3585 flags without explicitly listing them for each variable. 3586 3587- CONFIG_ENV_ACCESS_IGNORE_FORCE 3588 If defined, don't allow the -f switch to env set override variable 3589 access flags. 3590 3591- CONFIG_USE_STDINT 3592 If stdint.h is available with your toolchain you can define this 3593 option to enable it. You can provide option 'USE_STDINT=1' when 3594 building U-Boot to enable this. 3595 3596The following definitions that deal with the placement and management 3597of environment data (variable area); in general, we support the 3598following configurations: 3599 3600- CONFIG_BUILD_ENVCRC: 3601 3602 Builds up envcrc with the target environment so that external utils 3603 may easily extract it and embed it in final U-Boot images. 3604 3605- CONFIG_ENV_IS_IN_FLASH: 3606 3607 Define this if the environment is in flash memory. 3608 3609 a) The environment occupies one whole flash sector, which is 3610 "embedded" in the text segment with the U-Boot code. This 3611 happens usually with "bottom boot sector" or "top boot 3612 sector" type flash chips, which have several smaller 3613 sectors at the start or the end. For instance, such a 3614 layout can have sector sizes of 8, 2x4, 16, Nx32 kB. In 3615 such a case you would place the environment in one of the 3616 4 kB sectors - with U-Boot code before and after it. With 3617 "top boot sector" type flash chips, you would put the 3618 environment in one of the last sectors, leaving a gap 3619 between U-Boot and the environment. 3620 3621 - CONFIG_ENV_OFFSET: 3622 3623 Offset of environment data (variable area) to the 3624 beginning of flash memory; for instance, with bottom boot 3625 type flash chips the second sector can be used: the offset 3626 for this sector is given here. 3627 3628 CONFIG_ENV_OFFSET is used relative to CONFIG_SYS_FLASH_BASE. 3629 3630 - CONFIG_ENV_ADDR: 3631 3632 This is just another way to specify the start address of 3633 the flash sector containing the environment (instead of 3634 CONFIG_ENV_OFFSET). 3635 3636 - CONFIG_ENV_SECT_SIZE: 3637 3638 Size of the sector containing the environment. 3639 3640 3641 b) Sometimes flash chips have few, equal sized, BIG sectors. 3642 In such a case you don't want to spend a whole sector for 3643 the environment. 3644 3645 - CONFIG_ENV_SIZE: 3646 3647 If you use this in combination with CONFIG_ENV_IS_IN_FLASH 3648 and CONFIG_ENV_SECT_SIZE, you can specify to use only a part 3649 of this flash sector for the environment. This saves 3650 memory for the RAM copy of the environment. 3651 3652 It may also save flash memory if you decide to use this 3653 when your environment is "embedded" within U-Boot code, 3654 since then the remainder of the flash sector could be used 3655 for U-Boot code. It should be pointed out that this is 3656 STRONGLY DISCOURAGED from a robustness point of view: 3657 updating the environment in flash makes it always 3658 necessary to erase the WHOLE sector. If something goes 3659 wrong before the contents has been restored from a copy in 3660 RAM, your target system will be dead. 3661 3662 - CONFIG_ENV_ADDR_REDUND 3663 CONFIG_ENV_SIZE_REDUND 3664 3665 These settings describe a second storage area used to hold 3666 a redundant copy of the environment data, so that there is 3667 a valid backup copy in case there is a power failure during 3668 a "saveenv" operation. 3669 3670BE CAREFUL! Any changes to the flash layout, and some changes to the 3671source code will make it necessary to adapt <board>/u-boot.lds* 3672accordingly! 3673 3674 3675- CONFIG_ENV_IS_IN_NVRAM: 3676 3677 Define this if you have some non-volatile memory device 3678 (NVRAM, battery buffered SRAM) which you want to use for the 3679 environment. 3680 3681 - CONFIG_ENV_ADDR: 3682 - CONFIG_ENV_SIZE: 3683 3684 These two #defines are used to determine the memory area you 3685 want to use for environment. It is assumed that this memory 3686 can just be read and written to, without any special 3687 provision. 3688 3689BE CAREFUL! The first access to the environment happens quite early 3690in U-Boot initialization (when we try to get the setting of for the 3691console baudrate). You *MUST* have mapped your NVRAM area then, or 3692U-Boot will hang. 3693 3694Please note that even with NVRAM we still use a copy of the 3695environment in RAM: we could work on NVRAM directly, but we want to 3696keep settings there always unmodified except somebody uses "saveenv" 3697to save the current settings. 3698 3699 3700- CONFIG_ENV_IS_IN_EEPROM: 3701 3702 Use this if you have an EEPROM or similar serial access 3703 device and a driver for it. 3704 3705 - CONFIG_ENV_OFFSET: 3706 - CONFIG_ENV_SIZE: 3707 3708 These two #defines specify the offset and size of the 3709 environment area within the total memory of your EEPROM. 3710 3711 - CONFIG_SYS_I2C_EEPROM_ADDR: 3712 If defined, specified the chip address of the EEPROM device. 3713 The default address is zero. 3714 3715 - CONFIG_SYS_I2C_EEPROM_BUS: 3716 If defined, specified the i2c bus of the EEPROM device. 3717 3718 - CONFIG_SYS_EEPROM_PAGE_WRITE_BITS: 3719 If defined, the number of bits used to address bytes in a 3720 single page in the EEPROM device. A 64 byte page, for example 3721 would require six bits. 3722 3723 - CONFIG_SYS_EEPROM_PAGE_WRITE_DELAY_MS: 3724 If defined, the number of milliseconds to delay between 3725 page writes. The default is zero milliseconds. 3726 3727 - CONFIG_SYS_I2C_EEPROM_ADDR_LEN: 3728 The length in bytes of the EEPROM memory array address. Note 3729 that this is NOT the chip address length! 3730 3731 - CONFIG_SYS_I2C_EEPROM_ADDR_OVERFLOW: 3732 EEPROM chips that implement "address overflow" are ones 3733 like Catalyst 24WC04/08/16 which has 9/10/11 bits of 3734 address and the extra bits end up in the "chip address" bit 3735 slots. This makes a 24WC08 (1Kbyte) chip look like four 256 3736 byte chips. 3737 3738 Note that we consider the length of the address field to 3739 still be one byte because the extra address bits are hidden 3740 in the chip address. 3741 3742 - CONFIG_SYS_EEPROM_SIZE: 3743 The size in bytes of the EEPROM device. 3744 3745 - CONFIG_ENV_EEPROM_IS_ON_I2C 3746 define this, if you have I2C and SPI activated, and your 3747 EEPROM, which holds the environment, is on the I2C bus. 3748 3749 - CONFIG_I2C_ENV_EEPROM_BUS 3750 if you have an Environment on an EEPROM reached over 3751 I2C muxes, you can define here, how to reach this 3752 EEPROM. For example: 3753 3754 #define CONFIG_I2C_ENV_EEPROM_BUS 1 3755 3756 EEPROM which holds the environment, is reached over 3757 a pca9547 i2c mux with address 0x70, channel 3. 3758 3759- CONFIG_ENV_IS_IN_DATAFLASH: 3760 3761 Define this if you have a DataFlash memory device which you 3762 want to use for the environment. 3763 3764 - CONFIG_ENV_OFFSET: 3765 - CONFIG_ENV_ADDR: 3766 - CONFIG_ENV_SIZE: 3767 3768 These three #defines specify the offset and size of the 3769 environment area within the total memory of your DataFlash placed 3770 at the specified address. 3771 3772- CONFIG_ENV_IS_IN_SPI_FLASH: 3773 3774 Define this if you have a SPI Flash memory device which you 3775 want to use for the environment. 3776 3777 - CONFIG_ENV_OFFSET: 3778 - CONFIG_ENV_SIZE: 3779 3780 These two #defines specify the offset and size of the 3781 environment area within the SPI Flash. CONFIG_ENV_OFFSET must be 3782 aligned to an erase sector boundary. 3783 3784 - CONFIG_ENV_SECT_SIZE: 3785 3786 Define the SPI flash's sector size. 3787 3788 - CONFIG_ENV_OFFSET_REDUND (optional): 3789 3790 This setting describes a second storage area of CONFIG_ENV_SIZE 3791 size used to hold a redundant copy of the environment data, so 3792 that there is a valid backup copy in case there is a power failure 3793 during a "saveenv" operation. CONFIG_ENV_OFFSET_REDUND must be 3794 aligned to an erase sector boundary. 3795 3796 - CONFIG_ENV_SPI_BUS (optional): 3797 - CONFIG_ENV_SPI_CS (optional): 3798 3799 Define the SPI bus and chip select. If not defined they will be 0. 3800 3801 - CONFIG_ENV_SPI_MAX_HZ (optional): 3802 3803 Define the SPI max work clock. If not defined then use 1MHz. 3804 3805 - CONFIG_ENV_SPI_MODE (optional): 3806 3807 Define the SPI work mode. If not defined then use SPI_MODE_3. 3808 3809- CONFIG_ENV_IS_IN_REMOTE: 3810 3811 Define this if you have a remote memory space which you 3812 want to use for the local device's environment. 3813 3814 - CONFIG_ENV_ADDR: 3815 - CONFIG_ENV_SIZE: 3816 3817 These two #defines specify the address and size of the 3818 environment area within the remote memory space. The 3819 local device can get the environment from remote memory 3820 space by SRIO or PCIE links. 3821 3822BE CAREFUL! For some special cases, the local device can not use 3823"saveenv" command. For example, the local device will get the 3824environment stored in a remote NOR flash by SRIO or PCIE link, 3825but it can not erase, write this NOR flash by SRIO or PCIE interface. 3826 3827- CONFIG_ENV_IS_IN_NAND: 3828 3829 Define this if you have a NAND device which you want to use 3830 for the environment. 3831 3832 - CONFIG_ENV_OFFSET: 3833 - CONFIG_ENV_SIZE: 3834 3835 These two #defines specify the offset and size of the environment 3836 area within the first NAND device. CONFIG_ENV_OFFSET must be 3837 aligned to an erase block boundary. 3838 3839 - CONFIG_ENV_OFFSET_REDUND (optional): 3840 3841 This setting describes a second storage area of CONFIG_ENV_SIZE 3842 size used to hold a redundant copy of the environment data, so 3843 that there is a valid backup copy in case there is a power failure 3844 during a "saveenv" operation. CONFIG_ENV_OFFSET_REDUND must be 3845 aligned to an erase block boundary. 3846 3847 - CONFIG_ENV_RANGE (optional): 3848 3849 Specifies the length of the region in which the environment 3850 can be written. This should be a multiple of the NAND device's 3851 block size. Specifying a range with more erase blocks than 3852 are needed to hold CONFIG_ENV_SIZE allows bad blocks within 3853 the range to be avoided. 3854 3855 - CONFIG_ENV_OFFSET_OOB (optional): 3856 3857 Enables support for dynamically retrieving the offset of the 3858 environment from block zero's out-of-band data. The 3859 "nand env.oob" command can be used to record this offset. 3860 Currently, CONFIG_ENV_OFFSET_REDUND is not supported when 3861 using CONFIG_ENV_OFFSET_OOB. 3862 3863- CONFIG_NAND_ENV_DST 3864 3865 Defines address in RAM to which the nand_spl code should copy the 3866 environment. If redundant environment is used, it will be copied to 3867 CONFIG_NAND_ENV_DST + CONFIG_ENV_SIZE. 3868 3869- CONFIG_ENV_IS_IN_UBI: 3870 3871 Define this if you have an UBI volume that you want to use for the 3872 environment. This has the benefit of wear-leveling the environment 3873 accesses, which is important on NAND. 3874 3875 - CONFIG_ENV_UBI_PART: 3876 3877 Define this to a string that is the mtd partition containing the UBI. 3878 3879 - CONFIG_ENV_UBI_VOLUME: 3880 3881 Define this to the name of the volume that you want to store the 3882 environment in. 3883 3884 - CONFIG_ENV_UBI_VOLUME_REDUND: 3885 3886 Define this to the name of another volume to store a second copy of 3887 the environment in. This will enable redundant environments in UBI. 3888 It is assumed that both volumes are in the same MTD partition. 3889 3890 - CONFIG_UBI_SILENCE_MSG 3891 - CONFIG_UBIFS_SILENCE_MSG 3892 3893 You will probably want to define these to avoid a really noisy system 3894 when storing the env in UBI. 3895 3896- CONFIG_ENV_IS_IN_FAT: 3897 Define this if you want to use the FAT file system for the environment. 3898 3899 - FAT_ENV_INTERFACE: 3900 3901 Define this to a string that is the name of the block device. 3902 3903 - FAT_ENV_DEVICE_AND_PART: 3904 3905 Define this to a string to specify the partition of the device. It can 3906 be as following: 3907 3908 "D:P", "D:0", "D", "D:" or "D:auto" (D, P are integers. And P >= 1) 3909 - "D:P": device D partition P. Error occurs if device D has no 3910 partition table. 3911 - "D:0": device D. 3912 - "D" or "D:": device D partition 1 if device D has partition 3913 table, or the whole device D if has no partition 3914 table. 3915 - "D:auto": first partition in device D with bootable flag set. 3916 If none, first valid partition in device D. If no 3917 partition table then means device D. 3918 3919 - FAT_ENV_FILE: 3920 3921 It's a string of the FAT file name. This file use to store the 3922 environment. 3923 3924 - CONFIG_FAT_WRITE: 3925 This should be defined. Otherwise it cannot save the environment file. 3926 3927- CONFIG_ENV_IS_IN_MMC: 3928 3929 Define this if you have an MMC device which you want to use for the 3930 environment. 3931 3932 - CONFIG_SYS_MMC_ENV_DEV: 3933 3934 Specifies which MMC device the environment is stored in. 3935 3936 - CONFIG_SYS_MMC_ENV_PART (optional): 3937 3938 Specifies which MMC partition the environment is stored in. If not 3939 set, defaults to partition 0, the user area. Common values might be 3940 1 (first MMC boot partition), 2 (second MMC boot partition). 3941 3942 - CONFIG_ENV_OFFSET: 3943 - CONFIG_ENV_SIZE: 3944 3945 These two #defines specify the offset and size of the environment 3946 area within the specified MMC device. 3947 3948 If offset is positive (the usual case), it is treated as relative to 3949 the start of the MMC partition. If offset is negative, it is treated 3950 as relative to the end of the MMC partition. This can be useful if 3951 your board may be fitted with different MMC devices, which have 3952 different sizes for the MMC partitions, and you always want the 3953 environment placed at the very end of the partition, to leave the 3954 maximum possible space before it, to store other data. 3955 3956 These two values are in units of bytes, but must be aligned to an 3957 MMC sector boundary. 3958 3959 - CONFIG_ENV_OFFSET_REDUND (optional): 3960 3961 Specifies a second storage area, of CONFIG_ENV_SIZE size, used to 3962 hold a redundant copy of the environment data. This provides a 3963 valid backup copy in case the other copy is corrupted, e.g. due 3964 to a power failure during a "saveenv" operation. 3965 3966 This value may also be positive or negative; this is handled in the 3967 same way as CONFIG_ENV_OFFSET. 3968 3969 This value is also in units of bytes, but must also be aligned to 3970 an MMC sector boundary. 3971 3972 - CONFIG_ENV_SIZE_REDUND (optional): 3973 3974 This value need not be set, even when CONFIG_ENV_OFFSET_REDUND is 3975 set. If this value is set, it must be set to the same value as 3976 CONFIG_ENV_SIZE. 3977 3978- CONFIG_SYS_SPI_INIT_OFFSET 3979 3980 Defines offset to the initial SPI buffer area in DPRAM. The 3981 area is used at an early stage (ROM part) if the environment 3982 is configured to reside in the SPI EEPROM: We need a 520 byte 3983 scratch DPRAM area. It is used between the two initialization 3984 calls (spi_init_f() and spi_init_r()). A value of 0xB00 seems 3985 to be a good choice since it makes it far enough from the 3986 start of the data area as well as from the stack pointer. 3987 3988Please note that the environment is read-only until the monitor 3989has been relocated to RAM and a RAM copy of the environment has been 3990created; also, when using EEPROM you will have to use getenv_f() 3991until then to read environment variables. 3992 3993The environment is protected by a CRC32 checksum. Before the monitor 3994is relocated into RAM, as a result of a bad CRC you will be working 3995with the compiled-in default environment - *silently*!!! [This is 3996necessary, because the first environment variable we need is the 3997"baudrate" setting for the console - if we have a bad CRC, we don't 3998have any device yet where we could complain.] 3999 4000Note: once the monitor has been relocated, then it will complain if 4001the default environment is used; a new CRC is computed as soon as you 4002use the "saveenv" command to store a valid environment. 4003 4004- CONFIG_SYS_FAULT_ECHO_LINK_DOWN: 4005 Echo the inverted Ethernet link state to the fault LED. 4006 4007 Note: If this option is active, then CONFIG_SYS_FAULT_MII_ADDR 4008 also needs to be defined. 4009 4010- CONFIG_SYS_FAULT_MII_ADDR: 4011 MII address of the PHY to check for the Ethernet link state. 4012 4013- CONFIG_NS16550_MIN_FUNCTIONS: 4014 Define this if you desire to only have use of the NS16550_init 4015 and NS16550_putc functions for the serial driver located at 4016 drivers/serial/ns16550.c. This option is useful for saving 4017 space for already greatly restricted images, including but not 4018 limited to NAND_SPL configurations. 4019 4020- CONFIG_DISPLAY_BOARDINFO 4021 Display information about the board that U-Boot is running on 4022 when U-Boot starts up. The board function checkboard() is called 4023 to do this. 4024 4025- CONFIG_DISPLAY_BOARDINFO_LATE 4026 Similar to the previous option, but display this information 4027 later, once stdio is running and output goes to the LCD, if 4028 present. 4029 4030- CONFIG_BOARD_SIZE_LIMIT: 4031 Maximum size of the U-Boot image. When defined, the 4032 build system checks that the actual size does not 4033 exceed it. 4034 4035Low Level (hardware related) configuration options: 4036--------------------------------------------------- 4037 4038- CONFIG_SYS_CACHELINE_SIZE: 4039 Cache Line Size of the CPU. 4040 4041- CONFIG_SYS_DEFAULT_IMMR: 4042 Default address of the IMMR after system reset. 4043 4044 Needed on some 8260 systems (MPC8260ADS, PQ2FADS-ZU, 4045 and RPXsuper) to be able to adjust the position of 4046 the IMMR register after a reset. 4047 4048- CONFIG_SYS_CCSRBAR_DEFAULT: 4049 Default (power-on reset) physical address of CCSR on Freescale 4050 PowerPC SOCs. 4051 4052- CONFIG_SYS_CCSRBAR: 4053 Virtual address of CCSR. On a 32-bit build, this is typically 4054 the same value as CONFIG_SYS_CCSRBAR_DEFAULT. 4055 4056 CONFIG_SYS_DEFAULT_IMMR must also be set to this value, 4057 for cross-platform code that uses that macro instead. 4058 4059- CONFIG_SYS_CCSRBAR_PHYS: 4060 Physical address of CCSR. CCSR can be relocated to a new 4061 physical address, if desired. In this case, this macro should 4062 be set to that address. Otherwise, it should be set to the 4063 same value as CONFIG_SYS_CCSRBAR_DEFAULT. For example, CCSR 4064 is typically relocated on 36-bit builds. It is recommended 4065 that this macro be defined via the _HIGH and _LOW macros: 4066 4067 #define CONFIG_SYS_CCSRBAR_PHYS ((CONFIG_SYS_CCSRBAR_PHYS_HIGH 4068 * 1ull) << 32 | CONFIG_SYS_CCSRBAR_PHYS_LOW) 4069 4070- CONFIG_SYS_CCSRBAR_PHYS_HIGH: 4071 Bits 33-36 of CONFIG_SYS_CCSRBAR_PHYS. This value is typically 4072 either 0 (32-bit build) or 0xF (36-bit build). This macro is 4073 used in assembly code, so it must not contain typecasts or 4074 integer size suffixes (e.g. "ULL"). 4075 4076- CONFIG_SYS_CCSRBAR_PHYS_LOW: 4077 Lower 32-bits of CONFIG_SYS_CCSRBAR_PHYS. This macro is 4078 used in assembly code, so it must not contain typecasts or 4079 integer size suffixes (e.g. "ULL"). 4080 4081- CONFIG_SYS_CCSR_DO_NOT_RELOCATE: 4082 If this macro is defined, then CONFIG_SYS_CCSRBAR_PHYS will be 4083 forced to a value that ensures that CCSR is not relocated. 4084 4085- Floppy Disk Support: 4086 CONFIG_SYS_FDC_DRIVE_NUMBER 4087 4088 the default drive number (default value 0) 4089 4090 CONFIG_SYS_ISA_IO_STRIDE 4091 4092 defines the spacing between FDC chipset registers 4093 (default value 1) 4094 4095 CONFIG_SYS_ISA_IO_OFFSET 4096 4097 defines the offset of register from address. It 4098 depends on which part of the data bus is connected to 4099 the FDC chipset. (default value 0) 4100 4101 If CONFIG_SYS_ISA_IO_STRIDE CONFIG_SYS_ISA_IO_OFFSET and 4102 CONFIG_SYS_FDC_DRIVE_NUMBER are undefined, they take their 4103 default value. 4104 4105 if CONFIG_SYS_FDC_HW_INIT is defined, then the function 4106 fdc_hw_init() is called at the beginning of the FDC 4107 setup. fdc_hw_init() must be provided by the board 4108 source code. It is used to make hardware-dependent 4109 initializations. 4110 4111- CONFIG_IDE_AHB: 4112 Most IDE controllers were designed to be connected with PCI 4113 interface. Only few of them were designed for AHB interface. 4114 When software is doing ATA command and data transfer to 4115 IDE devices through IDE-AHB controller, some additional 4116 registers accessing to these kind of IDE-AHB controller 4117 is required. 4118 4119- CONFIG_SYS_IMMR: Physical address of the Internal Memory. 4120 DO NOT CHANGE unless you know exactly what you're 4121 doing! (11-4) [MPC8xx/82xx systems only] 4122 4123- CONFIG_SYS_INIT_RAM_ADDR: 4124 4125 Start address of memory area that can be used for 4126 initial data and stack; please note that this must be 4127 writable memory that is working WITHOUT special 4128 initialization, i. e. you CANNOT use normal RAM which 4129 will become available only after programming the 4130 memory controller and running certain initialization 4131 sequences. 4132 4133 U-Boot uses the following memory types: 4134 - MPC8xx and MPC8260: IMMR (internal memory of the CPU) 4135 - MPC824X: data cache 4136 - PPC4xx: data cache 4137 4138- CONFIG_SYS_GBL_DATA_OFFSET: 4139 4140 Offset of the initial data structure in the memory 4141 area defined by CONFIG_SYS_INIT_RAM_ADDR. Usually 4142 CONFIG_SYS_GBL_DATA_OFFSET is chosen such that the initial 4143 data is located at the end of the available space 4144 (sometimes written as (CONFIG_SYS_INIT_RAM_SIZE - 4145 GENERATED_GBL_DATA_SIZE), and the initial stack is just 4146 below that area (growing from (CONFIG_SYS_INIT_RAM_ADDR + 4147 CONFIG_SYS_GBL_DATA_OFFSET) downward. 4148 4149 Note: 4150 On the MPC824X (or other systems that use the data 4151 cache for initial memory) the address chosen for 4152 CONFIG_SYS_INIT_RAM_ADDR is basically arbitrary - it must 4153 point to an otherwise UNUSED address space between 4154 the top of RAM and the start of the PCI space. 4155 4156- CONFIG_SYS_SIUMCR: SIU Module Configuration (11-6) 4157 4158- CONFIG_SYS_SYPCR: System Protection Control (11-9) 4159 4160- CONFIG_SYS_TBSCR: Time Base Status and Control (11-26) 4161 4162- CONFIG_SYS_PISCR: Periodic Interrupt Status and Control (11-31) 4163 4164- CONFIG_SYS_PLPRCR: PLL, Low-Power, and Reset Control Register (15-30) 4165 4166- CONFIG_SYS_SCCR: System Clock and reset Control Register (15-27) 4167 4168- CONFIG_SYS_OR_TIMING_SDRAM: 4169 SDRAM timing 4170 4171- CONFIG_SYS_MAMR_PTA: 4172 periodic timer for refresh 4173 4174- CONFIG_SYS_DER: Debug Event Register (37-47) 4175 4176- FLASH_BASE0_PRELIM, FLASH_BASE1_PRELIM, CONFIG_SYS_REMAP_OR_AM, 4177 CONFIG_SYS_PRELIM_OR_AM, CONFIG_SYS_OR_TIMING_FLASH, CONFIG_SYS_OR0_REMAP, 4178 CONFIG_SYS_OR0_PRELIM, CONFIG_SYS_BR0_PRELIM, CONFIG_SYS_OR1_REMAP, CONFIG_SYS_OR1_PRELIM, 4179 CONFIG_SYS_BR1_PRELIM: 4180 Memory Controller Definitions: BR0/1 and OR0/1 (FLASH) 4181 4182- SDRAM_BASE2_PRELIM, SDRAM_BASE3_PRELIM, SDRAM_MAX_SIZE, 4183 CONFIG_SYS_OR_TIMING_SDRAM, CONFIG_SYS_OR2_PRELIM, CONFIG_SYS_BR2_PRELIM, 4184 CONFIG_SYS_OR3_PRELIM, CONFIG_SYS_BR3_PRELIM: 4185 Memory Controller Definitions: BR2/3 and OR2/3 (SDRAM) 4186 4187- CONFIG_SYS_MAMR_PTA, CONFIG_SYS_MPTPR_2BK_4K, CONFIG_SYS_MPTPR_1BK_4K, CONFIG_SYS_MPTPR_2BK_8K, 4188 CONFIG_SYS_MPTPR_1BK_8K, CONFIG_SYS_MAMR_8COL, CONFIG_SYS_MAMR_9COL: 4189 Machine Mode Register and Memory Periodic Timer 4190 Prescaler definitions (SDRAM timing) 4191 4192- CONFIG_SYS_I2C_UCODE_PATCH, CONFIG_SYS_I2C_DPMEM_OFFSET [0x1FC0]: 4193 enable I2C microcode relocation patch (MPC8xx); 4194 define relocation offset in DPRAM [DSP2] 4195 4196- CONFIG_SYS_SMC_UCODE_PATCH, CONFIG_SYS_SMC_DPMEM_OFFSET [0x1FC0]: 4197 enable SMC microcode relocation patch (MPC8xx); 4198 define relocation offset in DPRAM [SMC1] 4199 4200- CONFIG_SYS_SPI_UCODE_PATCH, CONFIG_SYS_SPI_DPMEM_OFFSET [0x1FC0]: 4201 enable SPI microcode relocation patch (MPC8xx); 4202 define relocation offset in DPRAM [SCC4] 4203 4204- CONFIG_SYS_CPM_POST_WORD_ADDR: (MPC8xx, MPC8260 only) 4205 Offset of the bootmode word in DPRAM used by post 4206 (Power On Self Tests). This definition overrides 4207 #define'd default value in commproc.h resp. 4208 cpm_8260.h. 4209 4210- CONFIG_SYS_PCI_SLV_MEM_LOCAL, CONFIG_SYS_PCI_SLV_MEM_BUS, CONFIG_SYS_PICMR0_MASK_ATTRIB, 4211 CONFIG_SYS_PCI_MSTR0_LOCAL, CONFIG_SYS_PCIMSK0_MASK, CONFIG_SYS_PCI_MSTR1_LOCAL, 4212 CONFIG_SYS_PCIMSK1_MASK, CONFIG_SYS_PCI_MSTR_MEM_LOCAL, CONFIG_SYS_PCI_MSTR_MEM_BUS, 4213 CONFIG_SYS_CPU_PCI_MEM_START, CONFIG_SYS_PCI_MSTR_MEM_SIZE, CONFIG_SYS_POCMR0_MASK_ATTRIB, 4214 CONFIG_SYS_PCI_MSTR_MEMIO_LOCAL, CONFIG_SYS_PCI_MSTR_MEMIO_BUS, CPU_PCI_MEMIO_START, 4215 CONFIG_SYS_PCI_MSTR_MEMIO_SIZE, CONFIG_SYS_POCMR1_MASK_ATTRIB, CONFIG_SYS_PCI_MSTR_IO_LOCAL, 4216 CONFIG_SYS_PCI_MSTR_IO_BUS, CONFIG_SYS_CPU_PCI_IO_START, CONFIG_SYS_PCI_MSTR_IO_SIZE, 4217 CONFIG_SYS_POCMR2_MASK_ATTRIB: (MPC826x only) 4218 Overrides the default PCI memory map in arch/powerpc/cpu/mpc8260/pci.c if set. 4219 4220- CONFIG_PCI_DISABLE_PCIE: 4221 Disable PCI-Express on systems where it is supported but not 4222 required. 4223 4224- CONFIG_PCI_ENUM_ONLY 4225 Only scan through and get the devices on the buses. 4226 Don't do any setup work, presumably because someone or 4227 something has already done it, and we don't need to do it 4228 a second time. Useful for platforms that are pre-booted 4229 by coreboot or similar. 4230 4231- CONFIG_PCI_INDIRECT_BRIDGE: 4232 Enable support for indirect PCI bridges. 4233 4234- CONFIG_SYS_SRIO: 4235 Chip has SRIO or not 4236 4237- CONFIG_SRIO1: 4238 Board has SRIO 1 port available 4239 4240- CONFIG_SRIO2: 4241 Board has SRIO 2 port available 4242 4243- CONFIG_SRIO_PCIE_BOOT_MASTER 4244 Board can support master function for Boot from SRIO and PCIE 4245 4246- CONFIG_SYS_SRIOn_MEM_VIRT: 4247 Virtual Address of SRIO port 'n' memory region 4248 4249- CONFIG_SYS_SRIOn_MEM_PHYS: 4250 Physical Address of SRIO port 'n' memory region 4251 4252- CONFIG_SYS_SRIOn_MEM_SIZE: 4253 Size of SRIO port 'n' memory region 4254 4255- CONFIG_SYS_NAND_BUSWIDTH_16BIT 4256 Defined to tell the NAND controller that the NAND chip is using 4257 a 16 bit bus. 4258 Not all NAND drivers use this symbol. 4259 Example of drivers that use it: 4260 - drivers/mtd/nand/ndfc.c 4261 - drivers/mtd/nand/mxc_nand.c 4262 4263- CONFIG_SYS_NDFC_EBC0_CFG 4264 Sets the EBC0_CFG register for the NDFC. If not defined 4265 a default value will be used. 4266 4267- CONFIG_SPD_EEPROM 4268 Get DDR timing information from an I2C EEPROM. Common 4269 with pluggable memory modules such as SODIMMs 4270 4271 SPD_EEPROM_ADDRESS 4272 I2C address of the SPD EEPROM 4273 4274- CONFIG_SYS_SPD_BUS_NUM 4275 If SPD EEPROM is on an I2C bus other than the first 4276 one, specify here. Note that the value must resolve 4277 to something your driver can deal with. 4278 4279- CONFIG_SYS_DDR_RAW_TIMING 4280 Get DDR timing information from other than SPD. Common with 4281 soldered DDR chips onboard without SPD. DDR raw timing 4282 parameters are extracted from datasheet and hard-coded into 4283 header files or board specific files. 4284 4285- CONFIG_FSL_DDR_INTERACTIVE 4286 Enable interactive DDR debugging. See doc/README.fsl-ddr. 4287 4288- CONFIG_FSL_DDR_SYNC_REFRESH 4289 Enable sync of refresh for multiple controllers. 4290 4291- CONFIG_FSL_DDR_BIST 4292 Enable built-in memory test for Freescale DDR controllers. 4293 4294- CONFIG_SYS_83XX_DDR_USES_CS0 4295 Only for 83xx systems. If specified, then DDR should 4296 be configured using CS0 and CS1 instead of CS2 and CS3. 4297 4298- CONFIG_ETHER_ON_FEC[12] 4299 Define to enable FEC[12] on a 8xx series processor. 4300 4301- CONFIG_FEC[12]_PHY 4302 Define to the hardcoded PHY address which corresponds 4303 to the given FEC; i. e. 4304 #define CONFIG_FEC1_PHY 4 4305 means that the PHY with address 4 is connected to FEC1 4306 4307 When set to -1, means to probe for first available. 4308 4309- CONFIG_FEC[12]_PHY_NORXERR 4310 The PHY does not have a RXERR line (RMII only). 4311 (so program the FEC to ignore it). 4312 4313- CONFIG_RMII 4314 Enable RMII mode for all FECs. 4315 Note that this is a global option, we can't 4316 have one FEC in standard MII mode and another in RMII mode. 4317 4318- CONFIG_CRC32_VERIFY 4319 Add a verify option to the crc32 command. 4320 The syntax is: 4321 4322 => crc32 -v <address> <count> <crc32> 4323 4324 Where address/count indicate a memory area 4325 and crc32 is the correct crc32 which the 4326 area should have. 4327 4328- CONFIG_LOOPW 4329 Add the "loopw" memory command. This only takes effect if 4330 the memory commands are activated globally (CONFIG_CMD_MEM). 4331 4332- CONFIG_MX_CYCLIC 4333 Add the "mdc" and "mwc" memory commands. These are cyclic 4334 "md/mw" commands. 4335 Examples: 4336 4337 => mdc.b 10 4 500 4338 This command will print 4 bytes (10,11,12,13) each 500 ms. 4339 4340 => mwc.l 100 12345678 10 4341 This command will write 12345678 to address 100 all 10 ms. 4342 4343 This only takes effect if the memory commands are activated 4344 globally (CONFIG_CMD_MEM). 4345 4346- CONFIG_SKIP_LOWLEVEL_INIT 4347 [ARM, NDS32, MIPS only] If this variable is defined, then certain 4348 low level initializations (like setting up the memory 4349 controller) are omitted and/or U-Boot does not 4350 relocate itself into RAM. 4351 4352 Normally this variable MUST NOT be defined. The only 4353 exception is when U-Boot is loaded (to RAM) by some 4354 other boot loader or by a debugger which performs 4355 these initializations itself. 4356 4357- CONFIG_SKIP_LOWLEVEL_INIT_ONLY 4358 [ARM926EJ-S only] This allows just the call to lowlevel_init() 4359 to be skipped. The normal CP15 init (such as enabling the 4360 instruction cache) is still performed. 4361 4362- CONFIG_SPL_BUILD 4363 Modifies the behaviour of start.S when compiling a loader 4364 that is executed before the actual U-Boot. E.g. when 4365 compiling a NAND SPL. 4366 4367- CONFIG_TPL_BUILD 4368 Modifies the behaviour of start.S when compiling a loader 4369 that is executed after the SPL and before the actual U-Boot. 4370 It is loaded by the SPL. 4371 4372- CONFIG_SYS_MPC85XX_NO_RESETVEC 4373 Only for 85xx systems. If this variable is specified, the section 4374 .resetvec is not kept and the section .bootpg is placed in the 4375 previous 4k of the .text section. 4376 4377- CONFIG_ARCH_MAP_SYSMEM 4378 Generally U-Boot (and in particular the md command) uses 4379 effective address. It is therefore not necessary to regard 4380 U-Boot address as virtual addresses that need to be translated 4381 to physical addresses. However, sandbox requires this, since 4382 it maintains its own little RAM buffer which contains all 4383 addressable memory. This option causes some memory accesses 4384 to be mapped through map_sysmem() / unmap_sysmem(). 4385 4386- CONFIG_X86_RESET_VECTOR 4387 If defined, the x86 reset vector code is included. This is not 4388 needed when U-Boot is running from Coreboot. 4389 4390- CONFIG_SPL_AM33XX_ENABLE_RTC32K_OSC: 4391 Enables the RTC32K OSC on AM33xx based plattforms 4392 4393- CONFIG_SYS_NAND_NO_SUBPAGE_WRITE 4394 Option to disable subpage write in NAND driver 4395 driver that uses this: 4396 drivers/mtd/nand/davinci_nand.c 4397 4398Freescale QE/FMAN Firmware Support: 4399----------------------------------- 4400 4401The Freescale QUICCEngine (QE) and Frame Manager (FMAN) both support the 4402loading of "firmware", which is encoded in the QE firmware binary format. 4403This firmware often needs to be loaded during U-Boot booting, so macros 4404are used to identify the storage device (NOR flash, SPI, etc) and the address 4405within that device. 4406 4407- CONFIG_SYS_FMAN_FW_ADDR 4408 The address in the storage device where the FMAN microcode is located. The 4409 meaning of this address depends on which CONFIG_SYS_QE_FW_IN_xxx macro 4410 is also specified. 4411 4412- CONFIG_SYS_QE_FW_ADDR 4413 The address in the storage device where the QE microcode is located. The 4414 meaning of this address depends on which CONFIG_SYS_QE_FW_IN_xxx macro 4415 is also specified. 4416 4417- CONFIG_SYS_QE_FMAN_FW_LENGTH 4418 The maximum possible size of the firmware. The firmware binary format 4419 has a field that specifies the actual size of the firmware, but it 4420 might not be possible to read any part of the firmware unless some 4421 local storage is allocated to hold the entire firmware first. 4422 4423- CONFIG_SYS_QE_FMAN_FW_IN_NOR 4424 Specifies that QE/FMAN firmware is located in NOR flash, mapped as 4425 normal addressable memory via the LBC. CONFIG_SYS_FMAN_FW_ADDR is the 4426 virtual address in NOR flash. 4427 4428- CONFIG_SYS_QE_FMAN_FW_IN_NAND 4429 Specifies that QE/FMAN firmware is located in NAND flash. 4430 CONFIG_SYS_FMAN_FW_ADDR is the offset within NAND flash. 4431 4432- CONFIG_SYS_QE_FMAN_FW_IN_MMC 4433 Specifies that QE/FMAN firmware is located on the primary SD/MMC 4434 device. CONFIG_SYS_FMAN_FW_ADDR is the byte offset on that device. 4435 4436- CONFIG_SYS_QE_FMAN_FW_IN_REMOTE 4437 Specifies that QE/FMAN firmware is located in the remote (master) 4438 memory space. CONFIG_SYS_FMAN_FW_ADDR is a virtual address which 4439 can be mapped from slave TLB->slave LAW->slave SRIO or PCIE outbound 4440 window->master inbound window->master LAW->the ucode address in 4441 master's memory space. 4442 4443Freescale Layerscape Management Complex Firmware Support: 4444--------------------------------------------------------- 4445The Freescale Layerscape Management Complex (MC) supports the loading of 4446"firmware". 4447This firmware often needs to be loaded during U-Boot booting, so macros 4448are used to identify the storage device (NOR flash, SPI, etc) and the address 4449within that device. 4450 4451- CONFIG_FSL_MC_ENET 4452 Enable the MC driver for Layerscape SoCs. 4453 4454Freescale Layerscape Debug Server Support: 4455------------------------------------------- 4456The Freescale Layerscape Debug Server Support supports the loading of 4457"Debug Server firmware" and triggering SP boot-rom. 4458This firmware often needs to be loaded during U-Boot booting. 4459 4460- CONFIG_SYS_MC_RSV_MEM_ALIGN 4461 Define alignment of reserved memory MC requires 4462 4463Reproducible builds 4464------------------- 4465 4466In order to achieve reproducible builds, timestamps used in the U-Boot build 4467process have to be set to a fixed value. 4468 4469This is done using the SOURCE_DATE_EPOCH environment variable. 4470SOURCE_DATE_EPOCH is to be set on the build host's shell, not as a configuration 4471option for U-Boot or an environment variable in U-Boot. 4472 4473SOURCE_DATE_EPOCH should be set to a number of seconds since the epoch, in UTC. 4474 4475Building the Software: 4476====================== 4477 4478Building U-Boot has been tested in several native build environments 4479and in many different cross environments. Of course we cannot support 4480all possibly existing versions of cross development tools in all 4481(potentially obsolete) versions. In case of tool chain problems we 4482recommend to use the ELDK (see http://www.denx.de/wiki/DULG/ELDK) 4483which is extensively used to build and test U-Boot. 4484 4485If you are not using a native environment, it is assumed that you 4486have GNU cross compiling tools available in your path. In this case, 4487you must set the environment variable CROSS_COMPILE in your shell. 4488Note that no changes to the Makefile or any other source files are 4489necessary. For example using the ELDK on a 4xx CPU, please enter: 4490 4491 $ CROSS_COMPILE=ppc_4xx- 4492 $ export CROSS_COMPILE 4493 4494Note: If you wish to generate Windows versions of the utilities in 4495 the tools directory you can use the MinGW toolchain 4496 (http://www.mingw.org). Set your HOST tools to the MinGW 4497 toolchain and execute 'make tools'. For example: 4498 4499 $ make HOSTCC=i586-mingw32msvc-gcc HOSTSTRIP=i586-mingw32msvc-strip tools 4500 4501 Binaries such as tools/mkimage.exe will be created which can 4502 be executed on computers running Windows. 4503 4504U-Boot is intended to be simple to build. After installing the 4505sources you must configure U-Boot for one specific board type. This 4506is done by typing: 4507 4508 make NAME_defconfig 4509 4510where "NAME_defconfig" is the name of one of the existing configu- 4511rations; see boards.cfg for supported names. 4512 4513Note: for some board special configuration names may exist; check if 4514 additional information is available from the board vendor; for 4515 instance, the TQM823L systems are available without (standard) 4516 or with LCD support. You can select such additional "features" 4517 when choosing the configuration, i. e. 4518 4519 make TQM823L_defconfig 4520 - will configure for a plain TQM823L, i. e. no LCD support 4521 4522 make TQM823L_LCD_defconfig 4523 - will configure for a TQM823L with U-Boot console on LCD 4524 4525 etc. 4526 4527 4528Finally, type "make all", and you should get some working U-Boot 4529images ready for download to / installation on your system: 4530 4531- "u-boot.bin" is a raw binary image 4532- "u-boot" is an image in ELF binary format 4533- "u-boot.srec" is in Motorola S-Record format 4534 4535By default the build is performed locally and the objects are saved 4536in the source directory. One of the two methods can be used to change 4537this behavior and build U-Boot to some external directory: 4538 45391. Add O= to the make command line invocations: 4540 4541 make O=/tmp/build distclean 4542 make O=/tmp/build NAME_defconfig 4543 make O=/tmp/build all 4544 45452. Set environment variable KBUILD_OUTPUT to point to the desired location: 4546 4547 export KBUILD_OUTPUT=/tmp/build 4548 make distclean 4549 make NAME_defconfig 4550 make all 4551 4552Note that the command line "O=" setting overrides the KBUILD_OUTPUT environment 4553variable. 4554 4555 4556Please be aware that the Makefiles assume you are using GNU make, so 4557for instance on NetBSD you might need to use "gmake" instead of 4558native "make". 4559 4560 4561If the system board that you have is not listed, then you will need 4562to port U-Boot to your hardware platform. To do this, follow these 4563steps: 4564 45651. Create a new directory to hold your board specific code. Add any 4566 files you need. In your board directory, you will need at least 4567 the "Makefile" and a "<board>.c". 45682. Create a new configuration file "include/configs/<board>.h" for 4569 your board. 45703. If you're porting U-Boot to a new CPU, then also create a new 4571 directory to hold your CPU specific code. Add any files you need. 45724. Run "make <board>_defconfig" with your new name. 45735. Type "make", and you should get a working "u-boot.srec" file 4574 to be installed on your target system. 45756. Debug and solve any problems that might arise. 4576 [Of course, this last step is much harder than it sounds.] 4577 4578 4579Testing of U-Boot Modifications, Ports to New Hardware, etc.: 4580============================================================== 4581 4582If you have modified U-Boot sources (for instance added a new board 4583or support for new devices, a new CPU, etc.) you are expected to 4584provide feedback to the other developers. The feedback normally takes 4585the form of a "patch", i. e. a context diff against a certain (latest 4586official or latest in the git repository) version of U-Boot sources. 4587 4588But before you submit such a patch, please verify that your modifi- 4589cation did not break existing code. At least make sure that *ALL* of 4590the supported boards compile WITHOUT ANY compiler warnings. To do so, 4591just run the buildman script (tools/buildman/buildman), which will 4592configure and build U-Boot for ALL supported system. Be warned, this 4593will take a while. Please see the buildman README, or run 'buildman -H' 4594for documentation. 4595 4596 4597See also "U-Boot Porting Guide" below. 4598 4599 4600Monitor Commands - Overview: 4601============================ 4602 4603go - start application at address 'addr' 4604run - run commands in an environment variable 4605bootm - boot application image from memory 4606bootp - boot image via network using BootP/TFTP protocol 4607bootz - boot zImage from memory 4608tftpboot- boot image via network using TFTP protocol 4609 and env variables "ipaddr" and "serverip" 4610 (and eventually "gatewayip") 4611tftpput - upload a file via network using TFTP protocol 4612rarpboot- boot image via network using RARP/TFTP protocol 4613diskboot- boot from IDE devicebootd - boot default, i.e., run 'bootcmd' 4614loads - load S-Record file over serial line 4615loadb - load binary file over serial line (kermit mode) 4616md - memory display 4617mm - memory modify (auto-incrementing) 4618nm - memory modify (constant address) 4619mw - memory write (fill) 4620cp - memory copy 4621cmp - memory compare 4622crc32 - checksum calculation 4623i2c - I2C sub-system 4624sspi - SPI utility commands 4625base - print or set address offset 4626printenv- print environment variables 4627setenv - set environment variables 4628saveenv - save environment variables to persistent storage 4629protect - enable or disable FLASH write protection 4630erase - erase FLASH memory 4631flinfo - print FLASH memory information 4632nand - NAND memory operations (see doc/README.nand) 4633bdinfo - print Board Info structure 4634iminfo - print header information for application image 4635coninfo - print console devices and informations 4636ide - IDE sub-system 4637loop - infinite loop on address range 4638loopw - infinite write loop on address range 4639mtest - simple RAM test 4640icache - enable or disable instruction cache 4641dcache - enable or disable data cache 4642reset - Perform RESET of the CPU 4643echo - echo args to console 4644version - print monitor version 4645help - print online help 4646? - alias for 'help' 4647 4648 4649Monitor Commands - Detailed Description: 4650======================================== 4651 4652TODO. 4653 4654For now: just type "help <command>". 4655 4656 4657Environment Variables: 4658====================== 4659 4660U-Boot supports user configuration using Environment Variables which 4661can be made persistent by saving to Flash memory. 4662 4663Environment Variables are set using "setenv", printed using 4664"printenv", and saved to Flash using "saveenv". Using "setenv" 4665without a value can be used to delete a variable from the 4666environment. As long as you don't save the environment you are 4667working with an in-memory copy. In case the Flash area containing the 4668environment is erased by accident, a default environment is provided. 4669 4670Some configuration options can be set using Environment Variables. 4671 4672List of environment variables (most likely not complete): 4673 4674 baudrate - see CONFIG_BAUDRATE 4675 4676 bootdelay - see CONFIG_BOOTDELAY 4677 4678 bootcmd - see CONFIG_BOOTCOMMAND 4679 4680 bootargs - Boot arguments when booting an RTOS image 4681 4682 bootfile - Name of the image to load with TFTP 4683 4684 bootm_low - Memory range available for image processing in the bootm 4685 command can be restricted. This variable is given as 4686 a hexadecimal number and defines lowest address allowed 4687 for use by the bootm command. See also "bootm_size" 4688 environment variable. Address defined by "bootm_low" is 4689 also the base of the initial memory mapping for the Linux 4690 kernel -- see the description of CONFIG_SYS_BOOTMAPSZ and 4691 bootm_mapsize. 4692 4693 bootm_mapsize - Size of the initial memory mapping for the Linux kernel. 4694 This variable is given as a hexadecimal number and it 4695 defines the size of the memory region starting at base 4696 address bootm_low that is accessible by the Linux kernel 4697 during early boot. If unset, CONFIG_SYS_BOOTMAPSZ is used 4698 as the default value if it is defined, and bootm_size is 4699 used otherwise. 4700 4701 bootm_size - Memory range available for image processing in the bootm 4702 command can be restricted. This variable is given as 4703 a hexadecimal number and defines the size of the region 4704 allowed for use by the bootm command. See also "bootm_low" 4705 environment variable. 4706 4707 updatefile - Location of the software update file on a TFTP server, used 4708 by the automatic software update feature. Please refer to 4709 documentation in doc/README.update for more details. 4710 4711 autoload - if set to "no" (any string beginning with 'n'), 4712 "bootp" will just load perform a lookup of the 4713 configuration from the BOOTP server, but not try to 4714 load any image using TFTP 4715 4716 autostart - if set to "yes", an image loaded using the "bootp", 4717 "rarpboot", "tftpboot" or "diskboot" commands will 4718 be automatically started (by internally calling 4719 "bootm") 4720 4721 If set to "no", a standalone image passed to the 4722 "bootm" command will be copied to the load address 4723 (and eventually uncompressed), but NOT be started. 4724 This can be used to load and uncompress arbitrary 4725 data. 4726 4727 fdt_high - if set this restricts the maximum address that the 4728 flattened device tree will be copied into upon boot. 4729 For example, if you have a system with 1 GB memory 4730 at physical address 0x10000000, while Linux kernel 4731 only recognizes the first 704 MB as low memory, you 4732 may need to set fdt_high as 0x3C000000 to have the 4733 device tree blob be copied to the maximum address 4734 of the 704 MB low memory, so that Linux kernel can 4735 access it during the boot procedure. 4736 4737 If this is set to the special value 0xFFFFFFFF then 4738 the fdt will not be copied at all on boot. For this 4739 to work it must reside in writable memory, have 4740 sufficient padding on the end of it for u-boot to 4741 add the information it needs into it, and the memory 4742 must be accessible by the kernel. 4743 4744 fdtcontroladdr- if set this is the address of the control flattened 4745 device tree used by U-Boot when CONFIG_OF_CONTROL is 4746 defined. 4747 4748 i2cfast - (PPC405GP|PPC405EP only) 4749 if set to 'y' configures Linux I2C driver for fast 4750 mode (400kHZ). This environment variable is used in 4751 initialization code. So, for changes to be effective 4752 it must be saved and board must be reset. 4753 4754 initrd_high - restrict positioning of initrd images: 4755 If this variable is not set, initrd images will be 4756 copied to the highest possible address in RAM; this 4757 is usually what you want since it allows for 4758 maximum initrd size. If for some reason you want to 4759 make sure that the initrd image is loaded below the 4760 CONFIG_SYS_BOOTMAPSZ limit, you can set this environment 4761 variable to a value of "no" or "off" or "0". 4762 Alternatively, you can set it to a maximum upper 4763 address to use (U-Boot will still check that it 4764 does not overwrite the U-Boot stack and data). 4765 4766 For instance, when you have a system with 16 MB 4767 RAM, and want to reserve 4 MB from use by Linux, 4768 you can do this by adding "mem=12M" to the value of 4769 the "bootargs" variable. However, now you must make 4770 sure that the initrd image is placed in the first 4771 12 MB as well - this can be done with 4772 4773 setenv initrd_high 00c00000 4774 4775 If you set initrd_high to 0xFFFFFFFF, this is an 4776 indication to U-Boot that all addresses are legal 4777 for the Linux kernel, including addresses in flash 4778 memory. In this case U-Boot will NOT COPY the 4779 ramdisk at all. This may be useful to reduce the 4780 boot time on your system, but requires that this 4781 feature is supported by your Linux kernel. 4782 4783 ipaddr - IP address; needed for tftpboot command 4784 4785 loadaddr - Default load address for commands like "bootp", 4786 "rarpboot", "tftpboot", "loadb" or "diskboot" 4787 4788 loads_echo - see CONFIG_LOADS_ECHO 4789 4790 serverip - TFTP server IP address; needed for tftpboot command 4791 4792 bootretry - see CONFIG_BOOT_RETRY_TIME 4793 4794 bootdelaykey - see CONFIG_AUTOBOOT_DELAY_STR 4795 4796 bootstopkey - see CONFIG_AUTOBOOT_STOP_STR 4797 4798 ethprime - controls which interface is used first. 4799 4800 ethact - controls which interface is currently active. 4801 For example you can do the following 4802 4803 => setenv ethact FEC 4804 => ping 192.168.0.1 # traffic sent on FEC 4805 => setenv ethact SCC 4806 => ping 10.0.0.1 # traffic sent on SCC 4807 4808 ethrotate - When set to "no" U-Boot does not go through all 4809 available network interfaces. 4810 It just stays at the currently selected interface. 4811 4812 netretry - When set to "no" each network operation will 4813 either succeed or fail without retrying. 4814 When set to "once" the network operation will 4815 fail when all the available network interfaces 4816 are tried once without success. 4817 Useful on scripts which control the retry operation 4818 themselves. 4819 4820 npe_ucode - set load address for the NPE microcode 4821 4822 silent_linux - If set then Linux will be told to boot silently, by 4823 changing the console to be empty. If "yes" it will be 4824 made silent. If "no" it will not be made silent. If 4825 unset, then it will be made silent if the U-Boot console 4826 is silent. 4827 4828 tftpsrcp - If this is set, the value is used for TFTP's 4829 UDP source port. 4830 4831 tftpdstp - If this is set, the value is used for TFTP's UDP 4832 destination port instead of the Well Know Port 69. 4833 4834 tftpblocksize - Block size to use for TFTP transfers; if not set, 4835 we use the TFTP server's default block size 4836 4837 tftptimeout - Retransmission timeout for TFTP packets (in milli- 4838 seconds, minimum value is 1000 = 1 second). Defines 4839 when a packet is considered to be lost so it has to 4840 be retransmitted. The default is 5000 = 5 seconds. 4841 Lowering this value may make downloads succeed 4842 faster in networks with high packet loss rates or 4843 with unreliable TFTP servers. 4844 4845 tftptimeoutcountmax - maximum count of TFTP timeouts (no 4846 unit, minimum value = 0). Defines how many timeouts 4847 can happen during a single file transfer before that 4848 transfer is aborted. The default is 10, and 0 means 4849 'no timeouts allowed'. Increasing this value may help 4850 downloads succeed with high packet loss rates, or with 4851 unreliable TFTP servers or client hardware. 4852 4853 vlan - When set to a value < 4095 the traffic over 4854 Ethernet is encapsulated/received over 802.1q 4855 VLAN tagged frames. 4856 4857 bootpretryperiod - Period during which BOOTP/DHCP sends retries. 4858 Unsigned value, in milliseconds. If not set, the period will 4859 be either the default (28000), or a value based on 4860 CONFIG_NET_RETRY_COUNT, if defined. This value has 4861 precedence over the valu based on CONFIG_NET_RETRY_COUNT. 4862 4863The following image location variables contain the location of images 4864used in booting. The "Image" column gives the role of the image and is 4865not an environment variable name. The other columns are environment 4866variable names. "File Name" gives the name of the file on a TFTP 4867server, "RAM Address" gives the location in RAM the image will be 4868loaded to, and "Flash Location" gives the image's address in NOR 4869flash or offset in NAND flash. 4870 4871*Note* - these variables don't have to be defined for all boards, some 4872boards currently use other variables for these purposes, and some 4873boards use these variables for other purposes. 4874 4875Image File Name RAM Address Flash Location 4876----- --------- ----------- -------------- 4877u-boot u-boot u-boot_addr_r u-boot_addr 4878Linux kernel bootfile kernel_addr_r kernel_addr 4879device tree blob fdtfile fdt_addr_r fdt_addr 4880ramdisk ramdiskfile ramdisk_addr_r ramdisk_addr 4881 4882The following environment variables may be used and automatically 4883updated by the network boot commands ("bootp" and "rarpboot"), 4884depending the information provided by your boot server: 4885 4886 bootfile - see above 4887 dnsip - IP address of your Domain Name Server 4888 dnsip2 - IP address of your secondary Domain Name Server 4889 gatewayip - IP address of the Gateway (Router) to use 4890 hostname - Target hostname 4891 ipaddr - see above 4892 netmask - Subnet Mask 4893 rootpath - Pathname of the root filesystem on the NFS server 4894 serverip - see above 4895 4896 4897There are two special Environment Variables: 4898 4899 serial# - contains hardware identification information such 4900 as type string and/or serial number 4901 ethaddr - Ethernet address 4902 4903These variables can be set only once (usually during manufacturing of 4904the board). U-Boot refuses to delete or overwrite these variables 4905once they have been set once. 4906 4907 4908Further special Environment Variables: 4909 4910 ver - Contains the U-Boot version string as printed 4911 with the "version" command. This variable is 4912 readonly (see CONFIG_VERSION_VARIABLE). 4913 4914 4915Please note that changes to some configuration parameters may take 4916only effect after the next boot (yes, that's just like Windoze :-). 4917 4918 4919Callback functions for environment variables: 4920--------------------------------------------- 4921 4922For some environment variables, the behavior of u-boot needs to change 4923when their values are changed. This functionality allows functions to 4924be associated with arbitrary variables. On creation, overwrite, or 4925deletion, the callback will provide the opportunity for some side 4926effect to happen or for the change to be rejected. 4927 4928The callbacks are named and associated with a function using the 4929U_BOOT_ENV_CALLBACK macro in your board or driver code. 4930 4931These callbacks are associated with variables in one of two ways. The 4932static list can be added to by defining CONFIG_ENV_CALLBACK_LIST_STATIC 4933in the board configuration to a string that defines a list of 4934associations. The list must be in the following format: 4935 4936 entry = variable_name[:callback_name] 4937 list = entry[,list] 4938 4939If the callback name is not specified, then the callback is deleted. 4940Spaces are also allowed anywhere in the list. 4941 4942Callbacks can also be associated by defining the ".callbacks" variable 4943with the same list format above. Any association in ".callbacks" will 4944override any association in the static list. You can define 4945CONFIG_ENV_CALLBACK_LIST_DEFAULT to a list (string) to define the 4946".callbacks" environment variable in the default or embedded environment. 4947 4948If CONFIG_REGEX is defined, the variable_name above is evaluated as a 4949regular expression. This allows multiple variables to be connected to 4950the same callback without explicitly listing them all out. 4951 4952 4953Command Line Parsing: 4954===================== 4955 4956There are two different command line parsers available with U-Boot: 4957the old "simple" one, and the much more powerful "hush" shell: 4958 4959Old, simple command line parser: 4960-------------------------------- 4961 4962- supports environment variables (through setenv / saveenv commands) 4963- several commands on one line, separated by ';' 4964- variable substitution using "... ${name} ..." syntax 4965- special characters ('$', ';') can be escaped by prefixing with '\', 4966 for example: 4967 setenv bootcmd bootm \${address} 4968- You can also escape text by enclosing in single apostrophes, for example: 4969 setenv addip 'setenv bootargs $bootargs ip=$ipaddr:$serverip:$gatewayip:$netmask:$hostname::off' 4970 4971Hush shell: 4972----------- 4973 4974- similar to Bourne shell, with control structures like 4975 if...then...else...fi, for...do...done; while...do...done, 4976 until...do...done, ... 4977- supports environment ("global") variables (through setenv / saveenv 4978 commands) and local shell variables (through standard shell syntax 4979 "name=value"); only environment variables can be used with "run" 4980 command 4981 4982General rules: 4983-------------- 4984 4985(1) If a command line (or an environment variable executed by a "run" 4986 command) contains several commands separated by semicolon, and 4987 one of these commands fails, then the remaining commands will be 4988 executed anyway. 4989 4990(2) If you execute several variables with one call to run (i. e. 4991 calling run with a list of variables as arguments), any failing 4992 command will cause "run" to terminate, i. e. the remaining 4993 variables are not executed. 4994 4995Note for Redundant Ethernet Interfaces: 4996======================================= 4997 4998Some boards come with redundant Ethernet interfaces; U-Boot supports 4999such configurations and is capable of automatic selection of a 5000"working" interface when needed. MAC assignment works as follows: 5001 5002Network interfaces are numbered eth0, eth1, eth2, ... Corresponding 5003MAC addresses can be stored in the environment as "ethaddr" (=>eth0), 5004"eth1addr" (=>eth1), "eth2addr", ... 5005 5006If the network interface stores some valid MAC address (for instance 5007in SROM), this is used as default address if there is NO correspon- 5008ding setting in the environment; if the corresponding environment 5009variable is set, this overrides the settings in the card; that means: 5010 5011o If the SROM has a valid MAC address, and there is no address in the 5012 environment, the SROM's address is used. 5013 5014o If there is no valid address in the SROM, and a definition in the 5015 environment exists, then the value from the environment variable is 5016 used. 5017 5018o If both the SROM and the environment contain a MAC address, and 5019 both addresses are the same, this MAC address is used. 5020 5021o If both the SROM and the environment contain a MAC address, and the 5022 addresses differ, the value from the environment is used and a 5023 warning is printed. 5024 5025o If neither SROM nor the environment contain a MAC address, an error 5026 is raised. If CONFIG_NET_RANDOM_ETHADDR is defined, then in this case 5027 a random, locally-assigned MAC is used. 5028 5029If Ethernet drivers implement the 'write_hwaddr' function, valid MAC addresses 5030will be programmed into hardware as part of the initialization process. This 5031may be skipped by setting the appropriate 'ethmacskip' environment variable. 5032The naming convention is as follows: 5033"ethmacskip" (=>eth0), "eth1macskip" (=>eth1) etc. 5034 5035Image Formats: 5036============== 5037 5038U-Boot is capable of booting (and performing other auxiliary operations on) 5039images in two formats: 5040 5041New uImage format (FIT) 5042----------------------- 5043 5044Flexible and powerful format based on Flattened Image Tree -- FIT (similar 5045to Flattened Device Tree). It allows the use of images with multiple 5046components (several kernels, ramdisks, etc.), with contents protected by 5047SHA1, MD5 or CRC32. More details are found in the doc/uImage.FIT directory. 5048 5049 5050Old uImage format 5051----------------- 5052 5053Old image format is based on binary files which can be basically anything, 5054preceded by a special header; see the definitions in include/image.h for 5055details; basically, the header defines the following image properties: 5056 5057* Target Operating System (Provisions for OpenBSD, NetBSD, FreeBSD, 5058 4.4BSD, Linux, SVR4, Esix, Solaris, Irix, SCO, Dell, NCR, VxWorks, 5059 LynxOS, pSOS, QNX, RTEMS, INTEGRITY; 5060 Currently supported: Linux, NetBSD, VxWorks, QNX, RTEMS, LynxOS, 5061 INTEGRITY). 5062* Target CPU Architecture (Provisions for Alpha, ARM, AVR32, Intel x86, 5063 IA64, MIPS, NDS32, Nios II, PowerPC, IBM S390, SuperH, Sparc, Sparc 64 Bit; 5064 Currently supported: ARM, AVR32, Intel x86, MIPS, NDS32, Nios II, PowerPC). 5065* Compression Type (uncompressed, gzip, bzip2) 5066* Load Address 5067* Entry Point 5068* Image Name 5069* Image Timestamp 5070 5071The header is marked by a special Magic Number, and both the header 5072and the data portions of the image are secured against corruption by 5073CRC32 checksums. 5074 5075 5076Linux Support: 5077============== 5078 5079Although U-Boot should support any OS or standalone application 5080easily, the main focus has always been on Linux during the design of 5081U-Boot. 5082 5083U-Boot includes many features that so far have been part of some 5084special "boot loader" code within the Linux kernel. Also, any 5085"initrd" images to be used are no longer part of one big Linux image; 5086instead, kernel and "initrd" are separate images. This implementation 5087serves several purposes: 5088 5089- the same features can be used for other OS or standalone 5090 applications (for instance: using compressed images to reduce the 5091 Flash memory footprint) 5092 5093- it becomes much easier to port new Linux kernel versions because 5094 lots of low-level, hardware dependent stuff are done by U-Boot 5095 5096- the same Linux kernel image can now be used with different "initrd" 5097 images; of course this also means that different kernel images can 5098 be run with the same "initrd". This makes testing easier (you don't 5099 have to build a new "zImage.initrd" Linux image when you just 5100 change a file in your "initrd"). Also, a field-upgrade of the 5101 software is easier now. 5102 5103 5104Linux HOWTO: 5105============ 5106 5107Porting Linux to U-Boot based systems: 5108--------------------------------------- 5109 5110U-Boot cannot save you from doing all the necessary modifications to 5111configure the Linux device drivers for use with your target hardware 5112(no, we don't intend to provide a full virtual machine interface to 5113Linux :-). 5114 5115But now you can ignore ALL boot loader code (in arch/powerpc/mbxboot). 5116 5117Just make sure your machine specific header file (for instance 5118include/asm-ppc/tqm8xx.h) includes the same definition of the Board 5119Information structure as we define in include/asm-<arch>/u-boot.h, 5120and make sure that your definition of IMAP_ADDR uses the same value 5121as your U-Boot configuration in CONFIG_SYS_IMMR. 5122 5123Note that U-Boot now has a driver model, a unified model for drivers. 5124If you are adding a new driver, plumb it into driver model. If there 5125is no uclass available, you are encouraged to create one. See 5126doc/driver-model. 5127 5128 5129Configuring the Linux kernel: 5130----------------------------- 5131 5132No specific requirements for U-Boot. Make sure you have some root 5133device (initial ramdisk, NFS) for your target system. 5134 5135 5136Building a Linux Image: 5137----------------------- 5138 5139With U-Boot, "normal" build targets like "zImage" or "bzImage" are 5140not used. If you use recent kernel source, a new build target 5141"uImage" will exist which automatically builds an image usable by 5142U-Boot. Most older kernels also have support for a "pImage" target, 5143which was introduced for our predecessor project PPCBoot and uses a 5144100% compatible format. 5145 5146Example: 5147 5148 make TQM850L_defconfig 5149 make oldconfig 5150 make dep 5151 make uImage 5152 5153The "uImage" build target uses a special tool (in 'tools/mkimage') to 5154encapsulate a compressed Linux kernel image with header information, 5155CRC32 checksum etc. for use with U-Boot. This is what we are doing: 5156 5157* build a standard "vmlinux" kernel image (in ELF binary format): 5158 5159* convert the kernel into a raw binary image: 5160 5161 ${CROSS_COMPILE}-objcopy -O binary \ 5162 -R .note -R .comment \ 5163 -S vmlinux linux.bin 5164 5165* compress the binary image: 5166 5167 gzip -9 linux.bin 5168 5169* package compressed binary image for U-Boot: 5170 5171 mkimage -A ppc -O linux -T kernel -C gzip \ 5172 -a 0 -e 0 -n "Linux Kernel Image" \ 5173 -d linux.bin.gz uImage 5174 5175 5176The "mkimage" tool can also be used to create ramdisk images for use 5177with U-Boot, either separated from the Linux kernel image, or 5178combined into one file. "mkimage" encapsulates the images with a 64 5179byte header containing information about target architecture, 5180operating system, image type, compression method, entry points, time 5181stamp, CRC32 checksums, etc. 5182 5183"mkimage" can be called in two ways: to verify existing images and 5184print the header information, or to build new images. 5185 5186In the first form (with "-l" option) mkimage lists the information 5187contained in the header of an existing U-Boot image; this includes 5188checksum verification: 5189 5190 tools/mkimage -l image 5191 -l ==> list image header information 5192 5193The second form (with "-d" option) is used to build a U-Boot image 5194from a "data file" which is used as image payload: 5195 5196 tools/mkimage -A arch -O os -T type -C comp -a addr -e ep \ 5197 -n name -d data_file image 5198 -A ==> set architecture to 'arch' 5199 -O ==> set operating system to 'os' 5200 -T ==> set image type to 'type' 5201 -C ==> set compression type 'comp' 5202 -a ==> set load address to 'addr' (hex) 5203 -e ==> set entry point to 'ep' (hex) 5204 -n ==> set image name to 'name' 5205 -d ==> use image data from 'datafile' 5206 5207Right now, all Linux kernels for PowerPC systems use the same load 5208address (0x00000000), but the entry point address depends on the 5209kernel version: 5210 5211- 2.2.x kernels have the entry point at 0x0000000C, 5212- 2.3.x and later kernels have the entry point at 0x00000000. 5213 5214So a typical call to build a U-Boot image would read: 5215 5216 -> tools/mkimage -n '2.4.4 kernel for TQM850L' \ 5217 > -A ppc -O linux -T kernel -C gzip -a 0 -e 0 \ 5218 > -d /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/powerpc/coffboot/vmlinux.gz \ 5219 > examples/uImage.TQM850L 5220 Image Name: 2.4.4 kernel for TQM850L 5221 Created: Wed Jul 19 02:34:59 2000 5222 Image Type: PowerPC Linux Kernel Image (gzip compressed) 5223 Data Size: 335725 Bytes = 327.86 kB = 0.32 MB 5224 Load Address: 0x00000000 5225 Entry Point: 0x00000000 5226 5227To verify the contents of the image (or check for corruption): 5228 5229 -> tools/mkimage -l examples/uImage.TQM850L 5230 Image Name: 2.4.4 kernel for TQM850L 5231 Created: Wed Jul 19 02:34:59 2000 5232 Image Type: PowerPC Linux Kernel Image (gzip compressed) 5233 Data Size: 335725 Bytes = 327.86 kB = 0.32 MB 5234 Load Address: 0x00000000 5235 Entry Point: 0x00000000 5236 5237NOTE: for embedded systems where boot time is critical you can trade 5238speed for memory and install an UNCOMPRESSED image instead: this 5239needs more space in Flash, but boots much faster since it does not 5240need to be uncompressed: 5241 5242 -> gunzip /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/powerpc/coffboot/vmlinux.gz 5243 -> tools/mkimage -n '2.4.4 kernel for TQM850L' \ 5244 > -A ppc -O linux -T kernel -C none -a 0 -e 0 \ 5245 > -d /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/powerpc/coffboot/vmlinux \ 5246 > examples/uImage.TQM850L-uncompressed 5247 Image Name: 2.4.4 kernel for TQM850L 5248 Created: Wed Jul 19 02:34:59 2000 5249 Image Type: PowerPC Linux Kernel Image (uncompressed) 5250 Data Size: 792160 Bytes = 773.59 kB = 0.76 MB 5251 Load Address: 0x00000000 5252 Entry Point: 0x00000000 5253 5254 5255Similar you can build U-Boot images from a 'ramdisk.image.gz' file 5256when your kernel is intended to use an initial ramdisk: 5257 5258 -> tools/mkimage -n 'Simple Ramdisk Image' \ 5259 > -A ppc -O linux -T ramdisk -C gzip \ 5260 > -d /LinuxPPC/images/SIMPLE-ramdisk.image.gz examples/simple-initrd 5261 Image Name: Simple Ramdisk Image 5262 Created: Wed Jan 12 14:01:50 2000 5263 Image Type: PowerPC Linux RAMDisk Image (gzip compressed) 5264 Data Size: 566530 Bytes = 553.25 kB = 0.54 MB 5265 Load Address: 0x00000000 5266 Entry Point: 0x00000000 5267 5268The "dumpimage" is a tool to disassemble images built by mkimage. Its "-i" 5269option performs the converse operation of the mkimage's second form (the "-d" 5270option). Given an image built by mkimage, the dumpimage extracts a "data file" 5271from the image: 5272 5273 tools/dumpimage -i image -T type -p position data_file 5274 -i ==> extract from the 'image' a specific 'data_file' 5275 -T ==> set image type to 'type' 5276 -p ==> 'position' (starting at 0) of the 'data_file' inside the 'image' 5277 5278 5279Installing a Linux Image: 5280------------------------- 5281 5282To downloading a U-Boot image over the serial (console) interface, 5283you must convert the image to S-Record format: 5284 5285 objcopy -I binary -O srec examples/image examples/image.srec 5286 5287The 'objcopy' does not understand the information in the U-Boot 5288image header, so the resulting S-Record file will be relative to 5289address 0x00000000. To load it to a given address, you need to 5290specify the target address as 'offset' parameter with the 'loads' 5291command. 5292 5293Example: install the image to address 0x40100000 (which on the 5294TQM8xxL is in the first Flash bank): 5295 5296 => erase 40100000 401FFFFF 5297 5298 .......... done 5299 Erased 8 sectors 5300 5301 => loads 40100000 5302 ## Ready for S-Record download ... 5303 ~>examples/image.srec 5304 1 2 3 4 5 6 7 8 9 10 11 12 13 ... 5305 ... 5306 15989 15990 15991 15992 5307 [file transfer complete] 5308 [connected] 5309 ## Start Addr = 0x00000000 5310 5311 5312You can check the success of the download using the 'iminfo' command; 5313this includes a checksum verification so you can be sure no data 5314corruption happened: 5315 5316 => imi 40100000 5317 5318 ## Checking Image at 40100000 ... 5319 Image Name: 2.2.13 for initrd on TQM850L 5320 Image Type: PowerPC Linux Kernel Image (gzip compressed) 5321 Data Size: 335725 Bytes = 327 kB = 0 MB 5322 Load Address: 00000000 5323 Entry Point: 0000000c 5324 Verifying Checksum ... OK 5325 5326 5327Boot Linux: 5328----------- 5329 5330The "bootm" command is used to boot an application that is stored in 5331memory (RAM or Flash). In case of a Linux kernel image, the contents 5332of the "bootargs" environment variable is passed to the kernel as 5333parameters. You can check and modify this variable using the 5334"printenv" and "setenv" commands: 5335 5336 5337 => printenv bootargs 5338 bootargs=root=/dev/ram 5339 5340 => setenv bootargs root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2 5341 5342 => printenv bootargs 5343 bootargs=root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2 5344 5345 => bootm 40020000 5346 ## Booting Linux kernel at 40020000 ... 5347 Image Name: 2.2.13 for NFS on TQM850L 5348 Image Type: PowerPC Linux Kernel Image (gzip compressed) 5349 Data Size: 381681 Bytes = 372 kB = 0 MB 5350 Load Address: 00000000 5351 Entry Point: 0000000c 5352 Verifying Checksum ... OK 5353 Uncompressing Kernel Image ... OK 5354 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 5355 Boot arguments: root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2 5356 time_init: decrementer frequency = 187500000/60 5357 Calibrating delay loop... 49.77 BogoMIPS 5358 Memory: 15208k available (700k kernel code, 444k data, 32k init) [c0000000,c1000000] 5359 ... 5360 5361If you want to boot a Linux kernel with initial RAM disk, you pass 5362the memory addresses of both the kernel and the initrd image (PPBCOOT 5363format!) to the "bootm" command: 5364 5365 => imi 40100000 40200000 5366 5367 ## Checking Image at 40100000 ... 5368 Image Name: 2.2.13 for initrd on TQM850L 5369 Image Type: PowerPC Linux Kernel Image (gzip compressed) 5370 Data Size: 335725 Bytes = 327 kB = 0 MB 5371 Load Address: 00000000 5372 Entry Point: 0000000c 5373 Verifying Checksum ... OK 5374 5375 ## Checking Image at 40200000 ... 5376 Image Name: Simple Ramdisk Image 5377 Image Type: PowerPC Linux RAMDisk Image (gzip compressed) 5378 Data Size: 566530 Bytes = 553 kB = 0 MB 5379 Load Address: 00000000 5380 Entry Point: 00000000 5381 Verifying Checksum ... OK 5382 5383 => bootm 40100000 40200000 5384 ## Booting Linux kernel at 40100000 ... 5385 Image Name: 2.2.13 for initrd on TQM850L 5386 Image Type: PowerPC Linux Kernel Image (gzip compressed) 5387 Data Size: 335725 Bytes = 327 kB = 0 MB 5388 Load Address: 00000000 5389 Entry Point: 0000000c 5390 Verifying Checksum ... OK 5391 Uncompressing Kernel Image ... OK 5392 ## Loading RAMDisk Image at 40200000 ... 5393 Image Name: Simple Ramdisk Image 5394 Image Type: PowerPC Linux RAMDisk Image (gzip compressed) 5395 Data Size: 566530 Bytes = 553 kB = 0 MB 5396 Load Address: 00000000 5397 Entry Point: 00000000 5398 Verifying Checksum ... OK 5399 Loading Ramdisk ... OK 5400 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 5401 Boot arguments: root=/dev/ram 5402 time_init: decrementer frequency = 187500000/60 5403 Calibrating delay loop... 49.77 BogoMIPS 5404 ... 5405 RAMDISK: Compressed image found at block 0 5406 VFS: Mounted root (ext2 filesystem). 5407 5408 bash# 5409 5410Boot Linux and pass a flat device tree: 5411----------- 5412 5413First, U-Boot must be compiled with the appropriate defines. See the section 5414titled "Linux Kernel Interface" above for a more in depth explanation. The 5415following is an example of how to start a kernel and pass an updated 5416flat device tree: 5417 5418=> print oftaddr 5419oftaddr=0x300000 5420=> print oft 5421oft=oftrees/mpc8540ads.dtb 5422=> tftp $oftaddr $oft 5423Speed: 1000, full duplex 5424Using TSEC0 device 5425TFTP from server 192.168.1.1; our IP address is 192.168.1.101 5426Filename 'oftrees/mpc8540ads.dtb'. 5427Load address: 0x300000 5428Loading: # 5429done 5430Bytes transferred = 4106 (100a hex) 5431=> tftp $loadaddr $bootfile 5432Speed: 1000, full duplex 5433Using TSEC0 device 5434TFTP from server 192.168.1.1; our IP address is 192.168.1.2 5435Filename 'uImage'. 5436Load address: 0x200000 5437Loading:############ 5438done 5439Bytes transferred = 1029407 (fb51f hex) 5440=> print loadaddr 5441loadaddr=200000 5442=> print oftaddr 5443oftaddr=0x300000 5444=> bootm $loadaddr - $oftaddr 5445## Booting image at 00200000 ... 5446 Image Name: Linux-2.6.17-dirty 5447 Image Type: PowerPC Linux Kernel Image (gzip compressed) 5448 Data Size: 1029343 Bytes = 1005.2 kB 5449 Load Address: 00000000 5450 Entry Point: 00000000 5451 Verifying Checksum ... OK 5452 Uncompressing Kernel Image ... OK 5453Booting using flat device tree at 0x300000 5454Using MPC85xx ADS machine description 5455Memory CAM mapping: CAM0=256Mb, CAM1=256Mb, CAM2=0Mb residual: 0Mb 5456[snip] 5457 5458 5459More About U-Boot Image Types: 5460------------------------------ 5461 5462U-Boot supports the following image types: 5463 5464 "Standalone Programs" are directly runnable in the environment 5465 provided by U-Boot; it is expected that (if they behave 5466 well) you can continue to work in U-Boot after return from 5467 the Standalone Program. 5468 "OS Kernel Images" are usually images of some Embedded OS which 5469 will take over control completely. Usually these programs 5470 will install their own set of exception handlers, device 5471 drivers, set up the MMU, etc. - this means, that you cannot 5472 expect to re-enter U-Boot except by resetting the CPU. 5473 "RAMDisk Images" are more or less just data blocks, and their 5474 parameters (address, size) are passed to an OS kernel that is 5475 being started. 5476 "Multi-File Images" contain several images, typically an OS 5477 (Linux) kernel image and one or more data images like 5478 RAMDisks. This construct is useful for instance when you want 5479 to boot over the network using BOOTP etc., where the boot 5480 server provides just a single image file, but you want to get 5481 for instance an OS kernel and a RAMDisk image. 5482 5483 "Multi-File Images" start with a list of image sizes, each 5484 image size (in bytes) specified by an "uint32_t" in network 5485 byte order. This list is terminated by an "(uint32_t)0". 5486 Immediately after the terminating 0 follow the images, one by 5487 one, all aligned on "uint32_t" boundaries (size rounded up to 5488 a multiple of 4 bytes). 5489 5490 "Firmware Images" are binary images containing firmware (like 5491 U-Boot or FPGA images) which usually will be programmed to 5492 flash memory. 5493 5494 "Script files" are command sequences that will be executed by 5495 U-Boot's command interpreter; this feature is especially 5496 useful when you configure U-Boot to use a real shell (hush) 5497 as command interpreter. 5498 5499Booting the Linux zImage: 5500------------------------- 5501 5502On some platforms, it's possible to boot Linux zImage. This is done 5503using the "bootz" command. The syntax of "bootz" command is the same 5504as the syntax of "bootm" command. 5505 5506Note, defining the CONFIG_SUPPORT_RAW_INITRD allows user to supply 5507kernel with raw initrd images. The syntax is slightly different, the 5508address of the initrd must be augmented by it's size, in the following 5509format: "<initrd addres>:<initrd size>". 5510 5511 5512Standalone HOWTO: 5513================= 5514 5515One of the features of U-Boot is that you can dynamically load and 5516run "standalone" applications, which can use some resources of 5517U-Boot like console I/O functions or interrupt services. 5518 5519Two simple examples are included with the sources: 5520 5521"Hello World" Demo: 5522------------------- 5523 5524'examples/hello_world.c' contains a small "Hello World" Demo 5525application; it is automatically compiled when you build U-Boot. 5526It's configured to run at address 0x00040004, so you can play with it 5527like that: 5528 5529 => loads 5530 ## Ready for S-Record download ... 5531 ~>examples/hello_world.srec 5532 1 2 3 4 5 6 7 8 9 10 11 ... 5533 [file transfer complete] 5534 [connected] 5535 ## Start Addr = 0x00040004 5536 5537 => go 40004 Hello World! This is a test. 5538 ## Starting application at 0x00040004 ... 5539 Hello World 5540 argc = 7 5541 argv[0] = "40004" 5542 argv[1] = "Hello" 5543 argv[2] = "World!" 5544 argv[3] = "This" 5545 argv[4] = "is" 5546 argv[5] = "a" 5547 argv[6] = "test." 5548 argv[7] = "<NULL>" 5549 Hit any key to exit ... 5550 5551 ## Application terminated, rc = 0x0 5552 5553Another example, which demonstrates how to register a CPM interrupt 5554handler with the U-Boot code, can be found in 'examples/timer.c'. 5555Here, a CPM timer is set up to generate an interrupt every second. 5556The interrupt service routine is trivial, just printing a '.' 5557character, but this is just a demo program. The application can be 5558controlled by the following keys: 5559 5560 ? - print current values og the CPM Timer registers 5561 b - enable interrupts and start timer 5562 e - stop timer and disable interrupts 5563 q - quit application 5564 5565 => loads 5566 ## Ready for S-Record download ... 5567 ~>examples/timer.srec 5568 1 2 3 4 5 6 7 8 9 10 11 ... 5569 [file transfer complete] 5570 [connected] 5571 ## Start Addr = 0x00040004 5572 5573 => go 40004 5574 ## Starting application at 0x00040004 ... 5575 TIMERS=0xfff00980 5576 Using timer 1 5577 tgcr @ 0xfff00980, tmr @ 0xfff00990, trr @ 0xfff00994, tcr @ 0xfff00998, tcn @ 0xfff0099c, ter @ 0xfff009b0 5578 5579Hit 'b': 5580 [q, b, e, ?] Set interval 1000000 us 5581 Enabling timer 5582Hit '?': 5583 [q, b, e, ?] ........ 5584 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0xef6, ter=0x0 5585Hit '?': 5586 [q, b, e, ?] . 5587 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x2ad4, ter=0x0 5588Hit '?': 5589 [q, b, e, ?] . 5590 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x1efc, ter=0x0 5591Hit '?': 5592 [q, b, e, ?] . 5593 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x169d, ter=0x0 5594Hit 'e': 5595 [q, b, e, ?] ...Stopping timer 5596Hit 'q': 5597 [q, b, e, ?] ## Application terminated, rc = 0x0 5598 5599 5600Minicom warning: 5601================ 5602 5603Over time, many people have reported problems when trying to use the 5604"minicom" terminal emulation program for serial download. I (wd) 5605consider minicom to be broken, and recommend not to use it. Under 5606Unix, I recommend to use C-Kermit for general purpose use (and 5607especially for kermit binary protocol download ("loadb" command), and 5608use "cu" for S-Record download ("loads" command). See 5609http://www.denx.de/wiki/view/DULG/SystemSetup#Section_4.3. 5610for help with kermit. 5611 5612 5613Nevertheless, if you absolutely want to use it try adding this 5614configuration to your "File transfer protocols" section: 5615 5616 Name Program Name U/D FullScr IO-Red. Multi 5617 X kermit /usr/bin/kermit -i -l %l -s Y U Y N N 5618 Y kermit /usr/bin/kermit -i -l %l -r N D Y N N 5619 5620 5621NetBSD Notes: 5622============= 5623 5624Starting at version 0.9.2, U-Boot supports NetBSD both as host 5625(build U-Boot) and target system (boots NetBSD/mpc8xx). 5626 5627Building requires a cross environment; it is known to work on 5628NetBSD/i386 with the cross-powerpc-netbsd-1.3 package (you will also 5629need gmake since the Makefiles are not compatible with BSD make). 5630Note that the cross-powerpc package does not install include files; 5631attempting to build U-Boot will fail because <machine/ansi.h> is 5632missing. This file has to be installed and patched manually: 5633 5634 # cd /usr/pkg/cross/powerpc-netbsd/include 5635 # mkdir powerpc 5636 # ln -s powerpc machine 5637 # cp /usr/src/sys/arch/powerpc/include/ansi.h powerpc/ansi.h 5638 # ${EDIT} powerpc/ansi.h ## must remove __va_list, _BSD_VA_LIST 5639 5640Native builds *don't* work due to incompatibilities between native 5641and U-Boot include files. 5642 5643Booting assumes that (the first part of) the image booted is a 5644stage-2 loader which in turn loads and then invokes the kernel 5645proper. Loader sources will eventually appear in the NetBSD source 5646tree (probably in sys/arc/mpc8xx/stand/u-boot_stage2/); in the 5647meantime, see ftp://ftp.denx.de/pub/u-boot/ppcboot_stage2.tar.gz 5648 5649 5650Implementation Internals: 5651========================= 5652 5653The following is not intended to be a complete description of every 5654implementation detail. However, it should help to understand the 5655inner workings of U-Boot and make it easier to port it to custom 5656hardware. 5657 5658 5659Initial Stack, Global Data: 5660--------------------------- 5661 5662The implementation of U-Boot is complicated by the fact that U-Boot 5663starts running out of ROM (flash memory), usually without access to 5664system RAM (because the memory controller is not initialized yet). 5665This means that we don't have writable Data or BSS segments, and BSS 5666is not initialized as zero. To be able to get a C environment working 5667at all, we have to allocate at least a minimal stack. Implementation 5668options for this are defined and restricted by the CPU used: Some CPU 5669models provide on-chip memory (like the IMMR area on MPC8xx and 5670MPC826x processors), on others (parts of) the data cache can be 5671locked as (mis-) used as memory, etc. 5672 5673 Chris Hallinan posted a good summary of these issues to the 5674 U-Boot mailing list: 5675 5676 Subject: RE: [U-Boot-Users] RE: More On Memory Bank x (nothingness)? 5677 From: "Chris Hallinan" <clh@net1plus.com> 5678 Date: Mon, 10 Feb 2003 16:43:46 -0500 (22:43 MET) 5679 ... 5680 5681 Correct me if I'm wrong, folks, but the way I understand it 5682 is this: Using DCACHE as initial RAM for Stack, etc, does not 5683 require any physical RAM backing up the cache. The cleverness 5684 is that the cache is being used as a temporary supply of 5685 necessary storage before the SDRAM controller is setup. It's 5686 beyond the scope of this list to explain the details, but you 5687 can see how this works by studying the cache architecture and 5688 operation in the architecture and processor-specific manuals. 5689 5690 OCM is On Chip Memory, which I believe the 405GP has 4K. It 5691 is another option for the system designer to use as an 5692 initial stack/RAM area prior to SDRAM being available. Either 5693 option should work for you. Using CS 4 should be fine if your 5694 board designers haven't used it for something that would 5695 cause you grief during the initial boot! It is frequently not 5696 used. 5697 5698 CONFIG_SYS_INIT_RAM_ADDR should be somewhere that won't interfere 5699 with your processor/board/system design. The default value 5700 you will find in any recent u-boot distribution in 5701 walnut.h should work for you. I'd set it to a value larger 5702 than your SDRAM module. If you have a 64MB SDRAM module, set 5703 it above 400_0000. Just make sure your board has no resources 5704 that are supposed to respond to that address! That code in 5705 start.S has been around a while and should work as is when 5706 you get the config right. 5707 5708 -Chris Hallinan 5709 DS4.COM, Inc. 5710 5711It is essential to remember this, since it has some impact on the C 5712code for the initialization procedures: 5713 5714* Initialized global data (data segment) is read-only. Do not attempt 5715 to write it. 5716 5717* Do not use any uninitialized global data (or implicitly initialized 5718 as zero data - BSS segment) at all - this is undefined, initiali- 5719 zation is performed later (when relocating to RAM). 5720 5721* Stack space is very limited. Avoid big data buffers or things like 5722 that. 5723 5724Having only the stack as writable memory limits means we cannot use 5725normal global data to share information between the code. But it 5726turned out that the implementation of U-Boot can be greatly 5727simplified by making a global data structure (gd_t) available to all 5728functions. We could pass a pointer to this data as argument to _all_ 5729functions, but this would bloat the code. Instead we use a feature of 5730the GCC compiler (Global Register Variables) to share the data: we 5731place a pointer (gd) to the global data into a register which we 5732reserve for this purpose. 5733 5734When choosing a register for such a purpose we are restricted by the 5735relevant (E)ABI specifications for the current architecture, and by 5736GCC's implementation. 5737 5738For PowerPC, the following registers have specific use: 5739 R1: stack pointer 5740 R2: reserved for system use 5741 R3-R4: parameter passing and return values 5742 R5-R10: parameter passing 5743 R13: small data area pointer 5744 R30: GOT pointer 5745 R31: frame pointer 5746 5747 (U-Boot also uses R12 as internal GOT pointer. r12 5748 is a volatile register so r12 needs to be reset when 5749 going back and forth between asm and C) 5750 5751 ==> U-Boot will use R2 to hold a pointer to the global data 5752 5753 Note: on PPC, we could use a static initializer (since the 5754 address of the global data structure is known at compile time), 5755 but it turned out that reserving a register results in somewhat 5756 smaller code - although the code savings are not that big (on 5757 average for all boards 752 bytes for the whole U-Boot image, 5758 624 text + 127 data). 5759 5760On ARM, the following registers are used: 5761 5762 R0: function argument word/integer result 5763 R1-R3: function argument word 5764 R9: platform specific 5765 R10: stack limit (used only if stack checking is enabled) 5766 R11: argument (frame) pointer 5767 R12: temporary workspace 5768 R13: stack pointer 5769 R14: link register 5770 R15: program counter 5771 5772 ==> U-Boot will use R9 to hold a pointer to the global data 5773 5774 Note: on ARM, only R_ARM_RELATIVE relocations are supported. 5775 5776On Nios II, the ABI is documented here: 5777 http://www.altera.com/literature/hb/nios2/n2cpu_nii51016.pdf 5778 5779 ==> U-Boot will use gp to hold a pointer to the global data 5780 5781 Note: on Nios II, we give "-G0" option to gcc and don't use gp 5782 to access small data sections, so gp is free. 5783 5784On NDS32, the following registers are used: 5785 5786 R0-R1: argument/return 5787 R2-R5: argument 5788 R15: temporary register for assembler 5789 R16: trampoline register 5790 R28: frame pointer (FP) 5791 R29: global pointer (GP) 5792 R30: link register (LP) 5793 R31: stack pointer (SP) 5794 PC: program counter (PC) 5795 5796 ==> U-Boot will use R10 to hold a pointer to the global data 5797 5798NOTE: DECLARE_GLOBAL_DATA_PTR must be used with file-global scope, 5799or current versions of GCC may "optimize" the code too much. 5800 5801Memory Management: 5802------------------ 5803 5804U-Boot runs in system state and uses physical addresses, i.e. the 5805MMU is not used either for address mapping nor for memory protection. 5806 5807The available memory is mapped to fixed addresses using the memory 5808controller. In this process, a contiguous block is formed for each 5809memory type (Flash, SDRAM, SRAM), even when it consists of several 5810physical memory banks. 5811 5812U-Boot is installed in the first 128 kB of the first Flash bank (on 5813TQM8xxL modules this is the range 0x40000000 ... 0x4001FFFF). After 5814booting and sizing and initializing DRAM, the code relocates itself 5815to the upper end of DRAM. Immediately below the U-Boot code some 5816memory is reserved for use by malloc() [see CONFIG_SYS_MALLOC_LEN 5817configuration setting]. Below that, a structure with global Board 5818Info data is placed, followed by the stack (growing downward). 5819 5820Additionally, some exception handler code is copied to the low 8 kB 5821of DRAM (0x00000000 ... 0x00001FFF). 5822 5823So a typical memory configuration with 16 MB of DRAM could look like 5824this: 5825 5826 0x0000 0000 Exception Vector code 5827 : 5828 0x0000 1FFF 5829 0x0000 2000 Free for Application Use 5830 : 5831 : 5832 5833 : 5834 : 5835 0x00FB FF20 Monitor Stack (Growing downward) 5836 0x00FB FFAC Board Info Data and permanent copy of global data 5837 0x00FC 0000 Malloc Arena 5838 : 5839 0x00FD FFFF 5840 0x00FE 0000 RAM Copy of Monitor Code 5841 ... eventually: LCD or video framebuffer 5842 ... eventually: pRAM (Protected RAM - unchanged by reset) 5843 0x00FF FFFF [End of RAM] 5844 5845 5846System Initialization: 5847---------------------- 5848 5849In the reset configuration, U-Boot starts at the reset entry point 5850(on most PowerPC systems at address 0x00000100). Because of the reset 5851configuration for CS0# this is a mirror of the on board Flash memory. 5852To be able to re-map memory U-Boot then jumps to its link address. 5853To be able to implement the initialization code in C, a (small!) 5854initial stack is set up in the internal Dual Ported RAM (in case CPUs 5855which provide such a feature like MPC8xx or MPC8260), or in a locked 5856part of the data cache. After that, U-Boot initializes the CPU core, 5857the caches and the SIU. 5858 5859Next, all (potentially) available memory banks are mapped using a 5860preliminary mapping. For example, we put them on 512 MB boundaries 5861(multiples of 0x20000000: SDRAM on 0x00000000 and 0x20000000, Flash 5862on 0x40000000 and 0x60000000, SRAM on 0x80000000). Then UPM A is 5863programmed for SDRAM access. Using the temporary configuration, a 5864simple memory test is run that determines the size of the SDRAM 5865banks. 5866 5867When there is more than one SDRAM bank, and the banks are of 5868different size, the largest is mapped first. For equal size, the first 5869bank (CS2#) is mapped first. The first mapping is always for address 58700x00000000, with any additional banks following immediately to create 5871contiguous memory starting from 0. 5872 5873Then, the monitor installs itself at the upper end of the SDRAM area 5874and allocates memory for use by malloc() and for the global Board 5875Info data; also, the exception vector code is copied to the low RAM 5876pages, and the final stack is set up. 5877 5878Only after this relocation will you have a "normal" C environment; 5879until that you are restricted in several ways, mostly because you are 5880running from ROM, and because the code will have to be relocated to a 5881new address in RAM. 5882 5883 5884U-Boot Porting Guide: 5885---------------------- 5886 5887[Based on messages by Jerry Van Baren in the U-Boot-Users mailing 5888list, October 2002] 5889 5890 5891int main(int argc, char *argv[]) 5892{ 5893 sighandler_t no_more_time; 5894 5895 signal(SIGALRM, no_more_time); 5896 alarm(PROJECT_DEADLINE - toSec (3 * WEEK)); 5897 5898 if (available_money > available_manpower) { 5899 Pay consultant to port U-Boot; 5900 return 0; 5901 } 5902 5903 Download latest U-Boot source; 5904 5905 Subscribe to u-boot mailing list; 5906 5907 if (clueless) 5908 email("Hi, I am new to U-Boot, how do I get started?"); 5909 5910 while (learning) { 5911 Read the README file in the top level directory; 5912 Read http://www.denx.de/twiki/bin/view/DULG/Manual; 5913 Read applicable doc/*.README; 5914 Read the source, Luke; 5915 /* find . -name "*.[chS]" | xargs grep -i <keyword> */ 5916 } 5917 5918 if (available_money > toLocalCurrency ($2500)) 5919 Buy a BDI3000; 5920 else 5921 Add a lot of aggravation and time; 5922 5923 if (a similar board exists) { /* hopefully... */ 5924 cp -a board/<similar> board/<myboard> 5925 cp include/configs/<similar>.h include/configs/<myboard>.h 5926 } else { 5927 Create your own board support subdirectory; 5928 Create your own board include/configs/<myboard>.h file; 5929 } 5930 Edit new board/<myboard> files 5931 Edit new include/configs/<myboard>.h 5932 5933 while (!accepted) { 5934 while (!running) { 5935 do { 5936 Add / modify source code; 5937 } until (compiles); 5938 Debug; 5939 if (clueless) 5940 email("Hi, I am having problems..."); 5941 } 5942 Send patch file to the U-Boot email list; 5943 if (reasonable critiques) 5944 Incorporate improvements from email list code review; 5945 else 5946 Defend code as written; 5947 } 5948 5949 return 0; 5950} 5951 5952void no_more_time (int sig) 5953{ 5954 hire_a_guru(); 5955} 5956 5957 5958Coding Standards: 5959----------------- 5960 5961All contributions to U-Boot should conform to the Linux kernel 5962coding style; see the file "Documentation/CodingStyle" and the script 5963"scripts/Lindent" in your Linux kernel source directory. 5964 5965Source files originating from a different project (for example the 5966MTD subsystem) are generally exempt from these guidelines and are not 5967reformatted to ease subsequent migration to newer versions of those 5968sources. 5969 5970Please note that U-Boot is implemented in C (and to some small parts in 5971Assembler); no C++ is used, so please do not use C++ style comments (//) 5972in your code. 5973 5974Please also stick to the following formatting rules: 5975- remove any trailing white space 5976- use TAB characters for indentation and vertical alignment, not spaces 5977- make sure NOT to use DOS '\r\n' line feeds 5978- do not add more than 2 consecutive empty lines to source files 5979- do not add trailing empty lines to source files 5980 5981Submissions which do not conform to the standards may be returned 5982with a request to reformat the changes. 5983 5984 5985Submitting Patches: 5986------------------- 5987 5988Since the number of patches for U-Boot is growing, we need to 5989establish some rules. Submissions which do not conform to these rules 5990may be rejected, even when they contain important and valuable stuff. 5991 5992Please see http://www.denx.de/wiki/U-Boot/Patches for details. 5993 5994Patches shall be sent to the u-boot mailing list <u-boot@lists.denx.de>; 5995see http://lists.denx.de/mailman/listinfo/u-boot 5996 5997When you send a patch, please include the following information with 5998it: 5999 6000* For bug fixes: a description of the bug and how your patch fixes 6001 this bug. Please try to include a way of demonstrating that the 6002 patch actually fixes something. 6003 6004* For new features: a description of the feature and your 6005 implementation. 6006 6007* A CHANGELOG entry as plaintext (separate from the patch) 6008 6009* For major contributions, add a MAINTAINERS file with your 6010 information and associated file and directory references. 6011 6012* When you add support for a new board, don't forget to add a 6013 maintainer e-mail address to the boards.cfg file, too. 6014 6015* If your patch adds new configuration options, don't forget to 6016 document these in the README file. 6017 6018* The patch itself. If you are using git (which is *strongly* 6019 recommended) you can easily generate the patch using the 6020 "git format-patch". If you then use "git send-email" to send it to 6021 the U-Boot mailing list, you will avoid most of the common problems 6022 with some other mail clients. 6023 6024 If you cannot use git, use "diff -purN OLD NEW". If your version of 6025 diff does not support these options, then get the latest version of 6026 GNU diff. 6027 6028 The current directory when running this command shall be the parent 6029 directory of the U-Boot source tree (i. e. please make sure that 6030 your patch includes sufficient directory information for the 6031 affected files). 6032 6033 We prefer patches as plain text. MIME attachments are discouraged, 6034 and compressed attachments must not be used. 6035 6036* If one logical set of modifications affects or creates several 6037 files, all these changes shall be submitted in a SINGLE patch file. 6038 6039* Changesets that contain different, unrelated modifications shall be 6040 submitted as SEPARATE patches, one patch per changeset. 6041 6042 6043Notes: 6044 6045* Before sending the patch, run the buildman script on your patched 6046 source tree and make sure that no errors or warnings are reported 6047 for any of the boards. 6048 6049* Keep your modifications to the necessary minimum: A patch 6050 containing several unrelated changes or arbitrary reformats will be 6051 returned with a request to re-formatting / split it. 6052 6053* If you modify existing code, make sure that your new code does not 6054 add to the memory footprint of the code ;-) Small is beautiful! 6055 When adding new features, these should compile conditionally only 6056 (using #ifdef), and the resulting code with the new feature 6057 disabled must not need more memory than the old code without your 6058 modification. 6059 6060* Remember that there is a size limit of 100 kB per message on the 6061 u-boot mailing list. Bigger patches will be moderated. If they are 6062 reasonable and not too big, they will be acknowledged. But patches 6063 bigger than the size limit should be avoided. 6064