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_FUSE * Device fuse support 848 CONFIG_CMD_GETTIME * Get time since boot 849 CONFIG_CMD_GO * the 'go' command (exec code) 850 CONFIG_CMD_GREPENV * search environment 851 CONFIG_CMD_HASH * calculate hash / digest 852 CONFIG_CMD_I2C * I2C serial bus support 853 CONFIG_CMD_IDE * IDE harddisk support 854 CONFIG_CMD_IMI iminfo 855 CONFIG_CMD_IMLS List all images found in NOR flash 856 CONFIG_CMD_IMLS_NAND * List all images found in NAND flash 857 CONFIG_CMD_IMMAP * IMMR dump support 858 CONFIG_CMD_IOTRACE * I/O tracing for debugging 859 CONFIG_CMD_IMPORTENV * import an environment 860 CONFIG_CMD_INI * import data from an ini file into the env 861 CONFIG_CMD_IRQ * irqinfo 862 CONFIG_CMD_ITEST Integer/string test of 2 values 863 CONFIG_CMD_JFFS2 * JFFS2 Support 864 CONFIG_CMD_KGDB * kgdb 865 CONFIG_CMD_LDRINFO * ldrinfo (display Blackfin loader) 866 CONFIG_CMD_LINK_LOCAL * link-local IP address auto-configuration 867 (169.254.*.*) 868 CONFIG_CMD_LOADB loadb 869 CONFIG_CMD_LOADS loads 870 CONFIG_CMD_MD5SUM * print md5 message digest 871 (requires CONFIG_CMD_MEMORY and CONFIG_MD5) 872 CONFIG_CMD_MEMINFO * Display detailed memory information 873 CONFIG_CMD_MEMORY md, mm, nm, mw, cp, cmp, crc, base, 874 loop, loopw 875 CONFIG_CMD_MEMTEST * mtest 876 CONFIG_CMD_MISC Misc functions like sleep etc 877 CONFIG_CMD_MMC * MMC memory mapped support 878 CONFIG_CMD_MII * MII utility commands 879 CONFIG_CMD_MTDPARTS * MTD partition support 880 CONFIG_CMD_NAND * NAND support 881 CONFIG_CMD_NET bootp, tftpboot, rarpboot 882 CONFIG_CMD_NFS NFS support 883 CONFIG_CMD_PCA953X * PCA953x I2C gpio commands 884 CONFIG_CMD_PCA953X_INFO * PCA953x I2C gpio info command 885 CONFIG_CMD_PCI * pciinfo 886 CONFIG_CMD_PCMCIA * PCMCIA support 887 CONFIG_CMD_PING * send ICMP ECHO_REQUEST to network 888 host 889 CONFIG_CMD_PORTIO * Port I/O 890 CONFIG_CMD_READ * Read raw data from partition 891 CONFIG_CMD_REGINFO * Register dump 892 CONFIG_CMD_RUN run command in env variable 893 CONFIG_CMD_SANDBOX * sb command to access sandbox features 894 CONFIG_CMD_SAVES * save S record dump 895 CONFIG_SCSI * SCSI Support 896 CONFIG_CMD_SDRAM * print SDRAM configuration information 897 (requires CONFIG_CMD_I2C) 898 CONFIG_CMD_SETGETDCR Support for DCR Register access 899 (4xx only) 900 CONFIG_CMD_SF * Read/write/erase SPI NOR flash 901 CONFIG_CMD_SHA1SUM * print sha1 memory digest 902 (requires CONFIG_CMD_MEMORY) 903 CONFIG_CMD_SOFTSWITCH * Soft switch setting command for BF60x 904 CONFIG_CMD_SOURCE "source" command Support 905 CONFIG_CMD_SPI * SPI serial bus support 906 CONFIG_CMD_TFTPSRV * TFTP transfer in server mode 907 CONFIG_CMD_TFTPPUT * TFTP put command (upload) 908 CONFIG_CMD_TIME * run command and report execution time (ARM specific) 909 CONFIG_CMD_TIMER * access to the system tick timer 910 CONFIG_CMD_USB * USB support 911 CONFIG_CMD_CDP * Cisco Discover Protocol support 912 CONFIG_CMD_MFSL * Microblaze FSL support 913 CONFIG_CMD_XIMG Load part of Multi Image 914 CONFIG_CMD_UUID * Generate random UUID or GUID string 915 916 EXAMPLE: If you want all functions except of network 917 support you can write: 918 919 #include "config_cmd_all.h" 920 #undef CONFIG_CMD_NET 921 922 Other Commands: 923 fdt (flattened device tree) command: CONFIG_OF_LIBFDT 924 925 Note: Don't enable the "icache" and "dcache" commands 926 (configuration option CONFIG_CMD_CACHE) unless you know 927 what you (and your U-Boot users) are doing. Data 928 cache cannot be enabled on systems like the 8xx or 929 8260 (where accesses to the IMMR region must be 930 uncached), and it cannot be disabled on all other 931 systems where we (mis-) use the data cache to hold an 932 initial stack and some data. 933 934 935 XXX - this list needs to get updated! 936 937- Removal of commands 938 If no commands are needed to boot, you can disable 939 CONFIG_CMDLINE to remove them. In this case, the command line 940 will not be available, and when U-Boot wants to execute the 941 boot command (on start-up) it will call board_run_command() 942 instead. This can reduce image size significantly for very 943 simple boot procedures. 944 945- Regular expression support: 946 CONFIG_REGEX 947 If this variable is defined, U-Boot is linked against 948 the SLRE (Super Light Regular Expression) library, 949 which adds regex support to some commands, as for 950 example "env grep" and "setexpr". 951 952- Device tree: 953 CONFIG_OF_CONTROL 954 If this variable is defined, U-Boot will use a device tree 955 to configure its devices, instead of relying on statically 956 compiled #defines in the board file. This option is 957 experimental and only available on a few boards. The device 958 tree is available in the global data as gd->fdt_blob. 959 960 U-Boot needs to get its device tree from somewhere. This can 961 be done using one of the three options below: 962 963 CONFIG_OF_EMBED 964 If this variable is defined, U-Boot will embed a device tree 965 binary in its image. This device tree file should be in the 966 board directory and called <soc>-<board>.dts. The binary file 967 is then picked up in board_init_f() and made available through 968 the global data structure as gd->blob. 969 970 CONFIG_OF_SEPARATE 971 If this variable is defined, U-Boot will build a device tree 972 binary. It will be called u-boot.dtb. Architecture-specific 973 code will locate it at run-time. Generally this works by: 974 975 cat u-boot.bin u-boot.dtb >image.bin 976 977 and in fact, U-Boot does this for you, creating a file called 978 u-boot-dtb.bin which is useful in the common case. You can 979 still use the individual files if you need something more 980 exotic. 981 982 CONFIG_OF_BOARD 983 If this variable is defined, U-Boot will use the device tree 984 provided by the board at runtime instead of embedding one with 985 the image. Only boards defining board_fdt_blob_setup() support 986 this option (see include/fdtdec.h file). 987 988- Watchdog: 989 CONFIG_WATCHDOG 990 If this variable is defined, it enables watchdog 991 support for the SoC. There must be support in the SoC 992 specific code for a watchdog. For the 8xx and 8260 993 CPUs, the SIU Watchdog feature is enabled in the SYPCR 994 register. When supported for a specific SoC is 995 available, then no further board specific code should 996 be needed to use it. 997 998 CONFIG_HW_WATCHDOG 999 When using a watchdog circuitry external to the used 1000 SoC, then define this variable and provide board 1001 specific code for the "hw_watchdog_reset" function. 1002 1003 CONFIG_AT91_HW_WDT_TIMEOUT 1004 specify the timeout in seconds. default 2 seconds. 1005 1006- U-Boot Version: 1007 CONFIG_VERSION_VARIABLE 1008 If this variable is defined, an environment variable 1009 named "ver" is created by U-Boot showing the U-Boot 1010 version as printed by the "version" command. 1011 Any change to this variable will be reverted at the 1012 next reset. 1013 1014- Real-Time Clock: 1015 1016 When CONFIG_CMD_DATE is selected, the type of the RTC 1017 has to be selected, too. Define exactly one of the 1018 following options: 1019 1020 CONFIG_RTC_MPC8xx - use internal RTC of MPC8xx 1021 CONFIG_RTC_PCF8563 - use Philips PCF8563 RTC 1022 CONFIG_RTC_MC13XXX - use MC13783 or MC13892 RTC 1023 CONFIG_RTC_MC146818 - use MC146818 RTC 1024 CONFIG_RTC_DS1307 - use Maxim, Inc. DS1307 RTC 1025 CONFIG_RTC_DS1337 - use Maxim, Inc. DS1337 RTC 1026 CONFIG_RTC_DS1338 - use Maxim, Inc. DS1338 RTC 1027 CONFIG_RTC_DS1339 - use Maxim, Inc. DS1339 RTC 1028 CONFIG_RTC_DS164x - use Dallas DS164x RTC 1029 CONFIG_RTC_ISL1208 - use Intersil ISL1208 RTC 1030 CONFIG_RTC_MAX6900 - use Maxim, Inc. MAX6900 RTC 1031 CONFIG_SYS_RTC_DS1337_NOOSC - Turn off the OSC output for DS1337 1032 CONFIG_SYS_RV3029_TCR - enable trickle charger on 1033 RV3029 RTC. 1034 1035 Note that if the RTC uses I2C, then the I2C interface 1036 must also be configured. See I2C Support, below. 1037 1038- GPIO Support: 1039 CONFIG_PCA953X - use NXP's PCA953X series I2C GPIO 1040 1041 The CONFIG_SYS_I2C_PCA953X_WIDTH option specifies a list of 1042 chip-ngpio pairs that tell the PCA953X driver the number of 1043 pins supported by a particular chip. 1044 1045 Note that if the GPIO device uses I2C, then the I2C interface 1046 must also be configured. See I2C Support, below. 1047 1048- I/O tracing: 1049 When CONFIG_IO_TRACE is selected, U-Boot intercepts all I/O 1050 accesses and can checksum them or write a list of them out 1051 to memory. See the 'iotrace' command for details. This is 1052 useful for testing device drivers since it can confirm that 1053 the driver behaves the same way before and after a code 1054 change. Currently this is supported on sandbox and arm. To 1055 add support for your architecture, add '#include <iotrace.h>' 1056 to the bottom of arch/<arch>/include/asm/io.h and test. 1057 1058 Example output from the 'iotrace stats' command is below. 1059 Note that if the trace buffer is exhausted, the checksum will 1060 still continue to operate. 1061 1062 iotrace is enabled 1063 Start: 10000000 (buffer start address) 1064 Size: 00010000 (buffer size) 1065 Offset: 00000120 (current buffer offset) 1066 Output: 10000120 (start + offset) 1067 Count: 00000018 (number of trace records) 1068 CRC32: 9526fb66 (CRC32 of all trace records) 1069 1070- Timestamp Support: 1071 1072 When CONFIG_TIMESTAMP is selected, the timestamp 1073 (date and time) of an image is printed by image 1074 commands like bootm or iminfo. This option is 1075 automatically enabled when you select CONFIG_CMD_DATE . 1076 1077- Partition Labels (disklabels) Supported: 1078 Zero or more of the following: 1079 CONFIG_MAC_PARTITION Apple's MacOS partition table. 1080 CONFIG_DOS_PARTITION MS Dos partition table, traditional on the 1081 Intel architecture, USB sticks, etc. 1082 CONFIG_ISO_PARTITION ISO partition table, used on CDROM etc. 1083 CONFIG_EFI_PARTITION GPT partition table, common when EFI is the 1084 bootloader. Note 2TB partition limit; see 1085 disk/part_efi.c 1086 CONFIG_MTD_PARTITIONS Memory Technology Device partition table. 1087 1088 If IDE or SCSI support is enabled (CONFIG_CMD_IDE or 1089 CONFIG_SCSI) you must configure support for at 1090 least one non-MTD partition type as well. 1091 1092- IDE Reset method: 1093 CONFIG_IDE_RESET_ROUTINE - this is defined in several 1094 board configurations files but used nowhere! 1095 1096 CONFIG_IDE_RESET - is this is defined, IDE Reset will 1097 be performed by calling the function 1098 ide_set_reset(int reset) 1099 which has to be defined in a board specific file 1100 1101- ATAPI Support: 1102 CONFIG_ATAPI 1103 1104 Set this to enable ATAPI support. 1105 1106- LBA48 Support 1107 CONFIG_LBA48 1108 1109 Set this to enable support for disks larger than 137GB 1110 Also look at CONFIG_SYS_64BIT_LBA. 1111 Whithout these , LBA48 support uses 32bit variables and will 'only' 1112 support disks up to 2.1TB. 1113 1114 CONFIG_SYS_64BIT_LBA: 1115 When enabled, makes the IDE subsystem use 64bit sector addresses. 1116 Default is 32bit. 1117 1118- SCSI Support: 1119 At the moment only there is only support for the 1120 SYM53C8XX SCSI controller; define 1121 CONFIG_SCSI_SYM53C8XX to enable it. 1122 1123 CONFIG_SYS_SCSI_MAX_LUN [8], CONFIG_SYS_SCSI_MAX_SCSI_ID [7] and 1124 CONFIG_SYS_SCSI_MAX_DEVICE [CONFIG_SYS_SCSI_MAX_SCSI_ID * 1125 CONFIG_SYS_SCSI_MAX_LUN] can be adjusted to define the 1126 maximum numbers of LUNs, SCSI ID's and target 1127 devices. 1128 CONFIG_SYS_SCSI_SYM53C8XX_CCF to fix clock timing (80Mhz) 1129 1130 The environment variable 'scsidevs' is set to the number of 1131 SCSI devices found during the last scan. 1132 1133- NETWORK Support (PCI): 1134 CONFIG_E1000 1135 Support for Intel 8254x/8257x gigabit chips. 1136 1137 CONFIG_E1000_SPI 1138 Utility code for direct access to the SPI bus on Intel 8257x. 1139 This does not do anything useful unless you set at least one 1140 of CONFIG_CMD_E1000 or CONFIG_E1000_SPI_GENERIC. 1141 1142 CONFIG_E1000_SPI_GENERIC 1143 Allow generic access to the SPI bus on the Intel 8257x, for 1144 example with the "sspi" command. 1145 1146 CONFIG_CMD_E1000 1147 Management command for E1000 devices. When used on devices 1148 with SPI support you can reprogram the EEPROM from U-Boot. 1149 1150 CONFIG_EEPRO100 1151 Support for Intel 82557/82559/82559ER chips. 1152 Optional CONFIG_EEPRO100_SROM_WRITE enables EEPROM 1153 write routine for first time initialisation. 1154 1155 CONFIG_TULIP 1156 Support for Digital 2114x chips. 1157 Optional CONFIG_TULIP_SELECT_MEDIA for board specific 1158 modem chip initialisation (KS8761/QS6611). 1159 1160 CONFIG_NATSEMI 1161 Support for National dp83815 chips. 1162 1163 CONFIG_NS8382X 1164 Support for National dp8382[01] gigabit chips. 1165 1166- NETWORK Support (other): 1167 1168 CONFIG_DRIVER_AT91EMAC 1169 Support for AT91RM9200 EMAC. 1170 1171 CONFIG_RMII 1172 Define this to use reduced MII inteface 1173 1174 CONFIG_DRIVER_AT91EMAC_QUIET 1175 If this defined, the driver is quiet. 1176 The driver doen't show link status messages. 1177 1178 CONFIG_CALXEDA_XGMAC 1179 Support for the Calxeda XGMAC device 1180 1181 CONFIG_LAN91C96 1182 Support for SMSC's LAN91C96 chips. 1183 1184 CONFIG_LAN91C96_USE_32_BIT 1185 Define this to enable 32 bit addressing 1186 1187 CONFIG_SMC91111 1188 Support for SMSC's LAN91C111 chip 1189 1190 CONFIG_SMC91111_BASE 1191 Define this to hold the physical address 1192 of the device (I/O space) 1193 1194 CONFIG_SMC_USE_32_BIT 1195 Define this if data bus is 32 bits 1196 1197 CONFIG_SMC_USE_IOFUNCS 1198 Define this to use i/o functions instead of macros 1199 (some hardware wont work with macros) 1200 1201 CONFIG_DRIVER_TI_EMAC 1202 Support for davinci emac 1203 1204 CONFIG_SYS_DAVINCI_EMAC_PHY_COUNT 1205 Define this if you have more then 3 PHYs. 1206 1207 CONFIG_FTGMAC100 1208 Support for Faraday's FTGMAC100 Gigabit SoC Ethernet 1209 1210 CONFIG_FTGMAC100_EGIGA 1211 Define this to use GE link update with gigabit PHY. 1212 Define this if FTGMAC100 is connected to gigabit PHY. 1213 If your system has 10/100 PHY only, it might not occur 1214 wrong behavior. Because PHY usually return timeout or 1215 useless data when polling gigabit status and gigabit 1216 control registers. This behavior won't affect the 1217 correctnessof 10/100 link speed update. 1218 1219 CONFIG_SMC911X 1220 Support for SMSC's LAN911x and LAN921x chips 1221 1222 CONFIG_SMC911X_BASE 1223 Define this to hold the physical address 1224 of the device (I/O space) 1225 1226 CONFIG_SMC911X_32_BIT 1227 Define this if data bus is 32 bits 1228 1229 CONFIG_SMC911X_16_BIT 1230 Define this if data bus is 16 bits. If your processor 1231 automatically converts one 32 bit word to two 16 bit 1232 words you may also try CONFIG_SMC911X_32_BIT. 1233 1234 CONFIG_SH_ETHER 1235 Support for Renesas on-chip Ethernet controller 1236 1237 CONFIG_SH_ETHER_USE_PORT 1238 Define the number of ports to be used 1239 1240 CONFIG_SH_ETHER_PHY_ADDR 1241 Define the ETH PHY's address 1242 1243 CONFIG_SH_ETHER_CACHE_WRITEBACK 1244 If this option is set, the driver enables cache flush. 1245 1246- PWM Support: 1247 CONFIG_PWM_IMX 1248 Support for PWM module on the imx6. 1249 1250- TPM Support: 1251 CONFIG_TPM 1252 Support TPM devices. 1253 1254 CONFIG_TPM_TIS_INFINEON 1255 Support for Infineon i2c bus TPM devices. Only one device 1256 per system is supported at this time. 1257 1258 CONFIG_TPM_TIS_I2C_BURST_LIMITATION 1259 Define the burst count bytes upper limit 1260 1261 CONFIG_TPM_ST33ZP24 1262 Support for STMicroelectronics TPM devices. Requires DM_TPM support. 1263 1264 CONFIG_TPM_ST33ZP24_I2C 1265 Support for STMicroelectronics ST33ZP24 I2C devices. 1266 Requires TPM_ST33ZP24 and I2C. 1267 1268 CONFIG_TPM_ST33ZP24_SPI 1269 Support for STMicroelectronics ST33ZP24 SPI devices. 1270 Requires TPM_ST33ZP24 and SPI. 1271 1272 CONFIG_TPM_ATMEL_TWI 1273 Support for Atmel TWI TPM device. Requires I2C support. 1274 1275 CONFIG_TPM_TIS_LPC 1276 Support for generic parallel port TPM devices. Only one device 1277 per system is supported at this time. 1278 1279 CONFIG_TPM_TIS_BASE_ADDRESS 1280 Base address where the generic TPM device is mapped 1281 to. Contemporary x86 systems usually map it at 1282 0xfed40000. 1283 1284 CONFIG_CMD_TPM 1285 Add tpm monitor functions. 1286 Requires CONFIG_TPM. If CONFIG_TPM_AUTH_SESSIONS is set, also 1287 provides monitor access to authorized functions. 1288 1289 CONFIG_TPM 1290 Define this to enable the TPM support library which provides 1291 functional interfaces to some TPM commands. 1292 Requires support for a TPM device. 1293 1294 CONFIG_TPM_AUTH_SESSIONS 1295 Define this to enable authorized functions in the TPM library. 1296 Requires CONFIG_TPM and CONFIG_SHA1. 1297 1298- USB Support: 1299 At the moment only the UHCI host controller is 1300 supported (PIP405, MIP405, MPC5200); define 1301 CONFIG_USB_UHCI to enable it. 1302 define CONFIG_USB_KEYBOARD to enable the USB Keyboard 1303 and define CONFIG_USB_STORAGE to enable the USB 1304 storage devices. 1305 Note: 1306 Supported are USB Keyboards and USB Floppy drives 1307 (TEAC FD-05PUB). 1308 MPC5200 USB requires additional defines: 1309 CONFIG_USB_CLOCK 1310 for 528 MHz Clock: 0x0001bbbb 1311 CONFIG_PSC3_USB 1312 for USB on PSC3 1313 CONFIG_USB_CONFIG 1314 for differential drivers: 0x00001000 1315 for single ended drivers: 0x00005000 1316 for differential drivers on PSC3: 0x00000100 1317 for single ended drivers on PSC3: 0x00004100 1318 CONFIG_SYS_USB_EVENT_POLL 1319 May be defined to allow interrupt polling 1320 instead of using asynchronous interrupts 1321 1322 CONFIG_USB_EHCI_TXFIFO_THRESH enables setting of the 1323 txfilltuning field in the EHCI controller on reset. 1324 1325 CONFIG_USB_DWC2_REG_ADDR the physical CPU address of the DWC2 1326 HW module registers. 1327 1328- USB Device: 1329 Define the below if you wish to use the USB console. 1330 Once firmware is rebuilt from a serial console issue the 1331 command "setenv stdin usbtty; setenv stdout usbtty" and 1332 attach your USB cable. The Unix command "dmesg" should print 1333 it has found a new device. The environment variable usbtty 1334 can be set to gserial or cdc_acm to enable your device to 1335 appear to a USB host as a Linux gserial device or a 1336 Common Device Class Abstract Control Model serial device. 1337 If you select usbtty = gserial you should be able to enumerate 1338 a Linux host by 1339 # modprobe usbserial vendor=0xVendorID product=0xProductID 1340 else if using cdc_acm, simply setting the environment 1341 variable usbtty to be cdc_acm should suffice. The following 1342 might be defined in YourBoardName.h 1343 1344 CONFIG_USB_DEVICE 1345 Define this to build a UDC device 1346 1347 CONFIG_USB_TTY 1348 Define this to have a tty type of device available to 1349 talk to the UDC device 1350 1351 CONFIG_USBD_HS 1352 Define this to enable the high speed support for usb 1353 device and usbtty. If this feature is enabled, a routine 1354 int is_usbd_high_speed(void) 1355 also needs to be defined by the driver to dynamically poll 1356 whether the enumeration has succeded at high speed or full 1357 speed. 1358 1359 CONFIG_SYS_CONSOLE_IS_IN_ENV 1360 Define this if you want stdin, stdout &/or stderr to 1361 be set to usbtty. 1362 1363 mpc8xx: 1364 CONFIG_SYS_USB_EXTC_CLK 0xBLAH 1365 Derive USB clock from external clock "blah" 1366 - CONFIG_SYS_USB_EXTC_CLK 0x02 1367 1368 If you have a USB-IF assigned VendorID then you may wish to 1369 define your own vendor specific values either in BoardName.h 1370 or directly in usbd_vendor_info.h. If you don't define 1371 CONFIG_USBD_MANUFACTURER, CONFIG_USBD_PRODUCT_NAME, 1372 CONFIG_USBD_VENDORID and CONFIG_USBD_PRODUCTID, then U-Boot 1373 should pretend to be a Linux device to it's target host. 1374 1375 CONFIG_USBD_MANUFACTURER 1376 Define this string as the name of your company for 1377 - CONFIG_USBD_MANUFACTURER "my company" 1378 1379 CONFIG_USBD_PRODUCT_NAME 1380 Define this string as the name of your product 1381 - CONFIG_USBD_PRODUCT_NAME "acme usb device" 1382 1383 CONFIG_USBD_VENDORID 1384 Define this as your assigned Vendor ID from the USB 1385 Implementors Forum. This *must* be a genuine Vendor ID 1386 to avoid polluting the USB namespace. 1387 - CONFIG_USBD_VENDORID 0xFFFF 1388 1389 CONFIG_USBD_PRODUCTID 1390 Define this as the unique Product ID 1391 for your device 1392 - CONFIG_USBD_PRODUCTID 0xFFFF 1393 1394- ULPI Layer Support: 1395 The ULPI (UTMI Low Pin (count) Interface) PHYs are supported via 1396 the generic ULPI layer. The generic layer accesses the ULPI PHY 1397 via the platform viewport, so you need both the genric layer and 1398 the viewport enabled. Currently only Chipidea/ARC based 1399 viewport is supported. 1400 To enable the ULPI layer support, define CONFIG_USB_ULPI and 1401 CONFIG_USB_ULPI_VIEWPORT in your board configuration file. 1402 If your ULPI phy needs a different reference clock than the 1403 standard 24 MHz then you have to define CONFIG_ULPI_REF_CLK to 1404 the appropriate value in Hz. 1405 1406- MMC Support: 1407 The MMC controller on the Intel PXA is supported. To 1408 enable this define CONFIG_MMC. The MMC can be 1409 accessed from the boot prompt by mapping the device 1410 to physical memory similar to flash. Command line is 1411 enabled with CONFIG_CMD_MMC. The MMC driver also works with 1412 the FAT fs. This is enabled with CONFIG_CMD_FAT. 1413 1414 CONFIG_SH_MMCIF 1415 Support for Renesas on-chip MMCIF controller 1416 1417 CONFIG_SH_MMCIF_ADDR 1418 Define the base address of MMCIF registers 1419 1420 CONFIG_SH_MMCIF_CLK 1421 Define the clock frequency for MMCIF 1422 1423 CONFIG_SUPPORT_EMMC_BOOT 1424 Enable some additional features of the eMMC boot partitions. 1425 1426 CONFIG_SUPPORT_EMMC_RPMB 1427 Enable the commands for reading, writing and programming the 1428 key for the Replay Protection Memory Block partition in eMMC. 1429 1430- USB Device Firmware Update (DFU) class support: 1431 CONFIG_USB_FUNCTION_DFU 1432 This enables the USB portion of the DFU USB class 1433 1434 CONFIG_CMD_DFU 1435 This enables the command "dfu" which is used to have 1436 U-Boot create a DFU class device via USB. This command 1437 requires that the "dfu_alt_info" environment variable be 1438 set and define the alt settings to expose to the host. 1439 1440 CONFIG_DFU_MMC 1441 This enables support for exposing (e)MMC devices via DFU. 1442 1443 CONFIG_DFU_NAND 1444 This enables support for exposing NAND devices via DFU. 1445 1446 CONFIG_DFU_RAM 1447 This enables support for exposing RAM via DFU. 1448 Note: DFU spec refer to non-volatile memory usage, but 1449 allow usages beyond the scope of spec - here RAM usage, 1450 one that would help mostly the developer. 1451 1452 CONFIG_SYS_DFU_DATA_BUF_SIZE 1453 Dfu transfer uses a buffer before writing data to the 1454 raw storage device. Make the size (in bytes) of this buffer 1455 configurable. The size of this buffer is also configurable 1456 through the "dfu_bufsiz" environment variable. 1457 1458 CONFIG_SYS_DFU_MAX_FILE_SIZE 1459 When updating files rather than the raw storage device, 1460 we use a static buffer to copy the file into and then write 1461 the buffer once we've been given the whole file. Define 1462 this to the maximum filesize (in bytes) for the buffer. 1463 Default is 4 MiB if undefined. 1464 1465 DFU_DEFAULT_POLL_TIMEOUT 1466 Poll timeout [ms], is the timeout a device can send to the 1467 host. The host must wait for this timeout before sending 1468 a subsequent DFU_GET_STATUS request to the device. 1469 1470 DFU_MANIFEST_POLL_TIMEOUT 1471 Poll timeout [ms], which the device sends to the host when 1472 entering dfuMANIFEST state. Host waits this timeout, before 1473 sending again an USB request to the device. 1474 1475- USB Device Android Fastboot support: 1476 CONFIG_USB_FUNCTION_FASTBOOT 1477 This enables the USB part of the fastboot gadget 1478 1479 CONFIG_CMD_FASTBOOT 1480 This enables the command "fastboot" which enables the Android 1481 fastboot mode for the platform's USB device. Fastboot is a USB 1482 protocol for downloading images, flashing and device control 1483 used on Android devices. 1484 See doc/README.android-fastboot for more information. 1485 1486 CONFIG_ANDROID_BOOT_IMAGE 1487 This enables support for booting images which use the Android 1488 image format header. 1489 1490 CONFIG_FASTBOOT_BUF_ADDR 1491 The fastboot protocol requires a large memory buffer for 1492 downloads. Define this to the starting RAM address to use for 1493 downloaded images. 1494 1495 CONFIG_FASTBOOT_BUF_SIZE 1496 The fastboot protocol requires a large memory buffer for 1497 downloads. This buffer should be as large as possible for a 1498 platform. Define this to the size available RAM for fastboot. 1499 1500 CONFIG_FASTBOOT_FLASH 1501 The fastboot protocol includes a "flash" command for writing 1502 the downloaded image to a non-volatile storage device. Define 1503 this to enable the "fastboot flash" command. 1504 1505 CONFIG_FASTBOOT_FLASH_MMC_DEV 1506 The fastboot "flash" command requires additional information 1507 regarding the non-volatile storage device. Define this to 1508 the eMMC device that fastboot should use to store the image. 1509 1510 CONFIG_FASTBOOT_GPT_NAME 1511 The fastboot "flash" command supports writing the downloaded 1512 image to the Protective MBR and the Primary GUID Partition 1513 Table. (Additionally, this downloaded image is post-processed 1514 to generate and write the Backup GUID Partition Table.) 1515 This occurs when the specified "partition name" on the 1516 "fastboot flash" command line matches this value. 1517 The default is "gpt" if undefined. 1518 1519 CONFIG_FASTBOOT_MBR_NAME 1520 The fastboot "flash" command supports writing the downloaded 1521 image to DOS MBR. 1522 This occurs when the "partition name" specified on the 1523 "fastboot flash" command line matches this value. 1524 If not defined the default value "mbr" is used. 1525 1526- Journaling Flash filesystem support: 1527 CONFIG_JFFS2_NAND 1528 Define these for a default partition on a NAND device 1529 1530 CONFIG_SYS_JFFS2_FIRST_SECTOR, 1531 CONFIG_SYS_JFFS2_FIRST_BANK, CONFIG_SYS_JFFS2_NUM_BANKS 1532 Define these for a default partition on a NOR device 1533 1534- FAT(File Allocation Table) filesystem write function support: 1535 CONFIG_FAT_WRITE 1536 1537 Define this to enable support for saving memory data as a 1538 file in FAT formatted partition. 1539 1540 This will also enable the command "fatwrite" enabling the 1541 user to write files to FAT. 1542 1543- FAT(File Allocation Table) filesystem cluster size: 1544 CONFIG_FS_FAT_MAX_CLUSTSIZE 1545 1546 Define the max cluster size for fat operations else 1547 a default value of 65536 will be defined. 1548 1549- Keyboard Support: 1550 See Kconfig help for available keyboard drivers. 1551 1552 CONFIG_KEYBOARD 1553 1554 Define this to enable a custom keyboard support. 1555 This simply calls drv_keyboard_init() which must be 1556 defined in your board-specific files. This option is deprecated 1557 and is only used by novena. For new boards, use driver model 1558 instead. 1559 1560- Video support: 1561 CONFIG_FSL_DIU_FB 1562 Enable the Freescale DIU video driver. Reference boards for 1563 SOCs that have a DIU should define this macro to enable DIU 1564 support, and should also define these other macros: 1565 1566 CONFIG_SYS_DIU_ADDR 1567 CONFIG_VIDEO 1568 CONFIG_CFB_CONSOLE 1569 CONFIG_VIDEO_SW_CURSOR 1570 CONFIG_VGA_AS_SINGLE_DEVICE 1571 CONFIG_VIDEO_LOGO 1572 CONFIG_VIDEO_BMP_LOGO 1573 1574 The DIU driver will look for the 'video-mode' environment 1575 variable, and if defined, enable the DIU as a console during 1576 boot. See the documentation file doc/README.video for a 1577 description of this variable. 1578 1579- LCD Support: CONFIG_LCD 1580 1581 Define this to enable LCD support (for output to LCD 1582 display); also select one of the supported displays 1583 by defining one of these: 1584 1585 CONFIG_ATMEL_LCD: 1586 1587 HITACHI TX09D70VM1CCA, 3.5", 240x320. 1588 1589 CONFIG_NEC_NL6448AC33: 1590 1591 NEC NL6448AC33-18. Active, color, single scan. 1592 1593 CONFIG_NEC_NL6448BC20 1594 1595 NEC NL6448BC20-08. 6.5", 640x480. 1596 Active, color, single scan. 1597 1598 CONFIG_NEC_NL6448BC33_54 1599 1600 NEC NL6448BC33-54. 10.4", 640x480. 1601 Active, color, single scan. 1602 1603 CONFIG_SHARP_16x9 1604 1605 Sharp 320x240. Active, color, single scan. 1606 It isn't 16x9, and I am not sure what it is. 1607 1608 CONFIG_SHARP_LQ64D341 1609 1610 Sharp LQ64D341 display, 640x480. 1611 Active, color, single scan. 1612 1613 CONFIG_HLD1045 1614 1615 HLD1045 display, 640x480. 1616 Active, color, single scan. 1617 1618 CONFIG_OPTREX_BW 1619 1620 Optrex CBL50840-2 NF-FW 99 22 M5 1621 or 1622 Hitachi LMG6912RPFC-00T 1623 or 1624 Hitachi SP14Q002 1625 1626 320x240. Black & white. 1627 1628 CONFIG_LCD_ALIGNMENT 1629 1630 Normally the LCD is page-aligned (typically 4KB). If this is 1631 defined then the LCD will be aligned to this value instead. 1632 For ARM it is sometimes useful to use MMU_SECTION_SIZE 1633 here, since it is cheaper to change data cache settings on 1634 a per-section basis. 1635 1636 1637 CONFIG_LCD_ROTATION 1638 1639 Sometimes, for example if the display is mounted in portrait 1640 mode or even if it's mounted landscape but rotated by 180degree, 1641 we need to rotate our content of the display relative to the 1642 framebuffer, so that user can read the messages which are 1643 printed out. 1644 Once CONFIG_LCD_ROTATION is defined, the lcd_console will be 1645 initialized with a given rotation from "vl_rot" out of 1646 "vidinfo_t" which is provided by the board specific code. 1647 The value for vl_rot is coded as following (matching to 1648 fbcon=rotate:<n> linux-kernel commandline): 1649 0 = no rotation respectively 0 degree 1650 1 = 90 degree rotation 1651 2 = 180 degree rotation 1652 3 = 270 degree rotation 1653 1654 If CONFIG_LCD_ROTATION is not defined, the console will be 1655 initialized with 0degree rotation. 1656 1657 CONFIG_LCD_BMP_RLE8 1658 1659 Support drawing of RLE8-compressed bitmaps on the LCD. 1660 1661 CONFIG_I2C_EDID 1662 1663 Enables an 'i2c edid' command which can read EDID 1664 information over I2C from an attached LCD display. 1665 1666- Splash Screen Support: CONFIG_SPLASH_SCREEN 1667 1668 If this option is set, the environment is checked for 1669 a variable "splashimage". If found, the usual display 1670 of logo, copyright and system information on the LCD 1671 is suppressed and the BMP image at the address 1672 specified in "splashimage" is loaded instead. The 1673 console is redirected to the "nulldev", too. This 1674 allows for a "silent" boot where a splash screen is 1675 loaded very quickly after power-on. 1676 1677 CONFIG_SPLASHIMAGE_GUARD 1678 1679 If this option is set, then U-Boot will prevent the environment 1680 variable "splashimage" from being set to a problematic address 1681 (see doc/README.displaying-bmps). 1682 This option is useful for targets where, due to alignment 1683 restrictions, an improperly aligned BMP image will cause a data 1684 abort. If you think you will not have problems with unaligned 1685 accesses (for example because your toolchain prevents them) 1686 there is no need to set this option. 1687 1688 CONFIG_SPLASH_SCREEN_ALIGN 1689 1690 If this option is set the splash image can be freely positioned 1691 on the screen. Environment variable "splashpos" specifies the 1692 position as "x,y". If a positive number is given it is used as 1693 number of pixel from left/top. If a negative number is given it 1694 is used as number of pixel from right/bottom. You can also 1695 specify 'm' for centering the image. 1696 1697 Example: 1698 setenv splashpos m,m 1699 => image at center of screen 1700 1701 setenv splashpos 30,20 1702 => image at x = 30 and y = 20 1703 1704 setenv splashpos -10,m 1705 => vertically centered image 1706 at x = dspWidth - bmpWidth - 9 1707 1708- Gzip compressed BMP image support: CONFIG_VIDEO_BMP_GZIP 1709 1710 If this option is set, additionally to standard BMP 1711 images, gzipped BMP images can be displayed via the 1712 splashscreen support or the bmp command. 1713 1714- Run length encoded BMP image (RLE8) support: CONFIG_VIDEO_BMP_RLE8 1715 1716 If this option is set, 8-bit RLE compressed BMP images 1717 can be displayed via the splashscreen support or the 1718 bmp command. 1719 1720- Compression support: 1721 CONFIG_GZIP 1722 1723 Enabled by default to support gzip compressed images. 1724 1725 CONFIG_BZIP2 1726 1727 If this option is set, support for bzip2 compressed 1728 images is included. If not, only uncompressed and gzip 1729 compressed images are supported. 1730 1731 NOTE: the bzip2 algorithm requires a lot of RAM, so 1732 the malloc area (as defined by CONFIG_SYS_MALLOC_LEN) should 1733 be at least 4MB. 1734 1735 CONFIG_LZMA 1736 1737 If this option is set, support for lzma compressed 1738 images is included. 1739 1740 Note: The LZMA algorithm adds between 2 and 4KB of code and it 1741 requires an amount of dynamic memory that is given by the 1742 formula: 1743 1744 (1846 + 768 << (lc + lp)) * sizeof(uint16) 1745 1746 Where lc and lp stand for, respectively, Literal context bits 1747 and Literal pos bits. 1748 1749 This value is upper-bounded by 14MB in the worst case. Anyway, 1750 for a ~4MB large kernel image, we have lc=3 and lp=0 for a 1751 total amount of (1846 + 768 << (3 + 0)) * 2 = ~41KB... that is 1752 a very small buffer. 1753 1754 Use the lzmainfo tool to determinate the lc and lp values and 1755 then calculate the amount of needed dynamic memory (ensuring 1756 the appropriate CONFIG_SYS_MALLOC_LEN value). 1757 1758 CONFIG_LZO 1759 1760 If this option is set, support for LZO compressed images 1761 is included. 1762 1763- MII/PHY support: 1764 CONFIG_PHY_ADDR 1765 1766 The address of PHY on MII bus. 1767 1768 CONFIG_PHY_CLOCK_FREQ (ppc4xx) 1769 1770 The clock frequency of the MII bus 1771 1772 CONFIG_PHY_GIGE 1773 1774 If this option is set, support for speed/duplex 1775 detection of gigabit PHY is included. 1776 1777 CONFIG_PHY_RESET_DELAY 1778 1779 Some PHY like Intel LXT971A need extra delay after 1780 reset before any MII register access is possible. 1781 For such PHY, set this option to the usec delay 1782 required. (minimum 300usec for LXT971A) 1783 1784 CONFIG_PHY_CMD_DELAY (ppc4xx) 1785 1786 Some PHY like Intel LXT971A need extra delay after 1787 command issued before MII status register can be read 1788 1789- IP address: 1790 CONFIG_IPADDR 1791 1792 Define a default value for the IP address to use for 1793 the default Ethernet interface, in case this is not 1794 determined through e.g. bootp. 1795 (Environment variable "ipaddr") 1796 1797- Server IP address: 1798 CONFIG_SERVERIP 1799 1800 Defines a default value for the IP address of a TFTP 1801 server to contact when using the "tftboot" command. 1802 (Environment variable "serverip") 1803 1804 CONFIG_KEEP_SERVERADDR 1805 1806 Keeps the server's MAC address, in the env 'serveraddr' 1807 for passing to bootargs (like Linux's netconsole option) 1808 1809- Gateway IP address: 1810 CONFIG_GATEWAYIP 1811 1812 Defines a default value for the IP address of the 1813 default router where packets to other networks are 1814 sent to. 1815 (Environment variable "gatewayip") 1816 1817- Subnet mask: 1818 CONFIG_NETMASK 1819 1820 Defines a default value for the subnet mask (or 1821 routing prefix) which is used to determine if an IP 1822 address belongs to the local subnet or needs to be 1823 forwarded through a router. 1824 (Environment variable "netmask") 1825 1826- Multicast TFTP Mode: 1827 CONFIG_MCAST_TFTP 1828 1829 Defines whether you want to support multicast TFTP as per 1830 rfc-2090; for example to work with atftp. Lets lots of targets 1831 tftp down the same boot image concurrently. Note: the Ethernet 1832 driver in use must provide a function: mcast() to join/leave a 1833 multicast group. 1834 1835- BOOTP Recovery Mode: 1836 CONFIG_BOOTP_RANDOM_DELAY 1837 1838 If you have many targets in a network that try to 1839 boot using BOOTP, you may want to avoid that all 1840 systems send out BOOTP requests at precisely the same 1841 moment (which would happen for instance at recovery 1842 from a power failure, when all systems will try to 1843 boot, thus flooding the BOOTP server. Defining 1844 CONFIG_BOOTP_RANDOM_DELAY causes a random delay to be 1845 inserted before sending out BOOTP requests. The 1846 following delays are inserted then: 1847 1848 1st BOOTP request: delay 0 ... 1 sec 1849 2nd BOOTP request: delay 0 ... 2 sec 1850 3rd BOOTP request: delay 0 ... 4 sec 1851 4th and following 1852 BOOTP requests: delay 0 ... 8 sec 1853 1854 CONFIG_BOOTP_ID_CACHE_SIZE 1855 1856 BOOTP packets are uniquely identified using a 32-bit ID. The 1857 server will copy the ID from client requests to responses and 1858 U-Boot will use this to determine if it is the destination of 1859 an incoming response. Some servers will check that addresses 1860 aren't in use before handing them out (usually using an ARP 1861 ping) and therefore take up to a few hundred milliseconds to 1862 respond. Network congestion may also influence the time it 1863 takes for a response to make it back to the client. If that 1864 time is too long, U-Boot will retransmit requests. In order 1865 to allow earlier responses to still be accepted after these 1866 retransmissions, U-Boot's BOOTP client keeps a small cache of 1867 IDs. The CONFIG_BOOTP_ID_CACHE_SIZE controls the size of this 1868 cache. The default is to keep IDs for up to four outstanding 1869 requests. Increasing this will allow U-Boot to accept offers 1870 from a BOOTP client in networks with unusually high latency. 1871 1872- DHCP Advanced Options: 1873 You can fine tune the DHCP functionality by defining 1874 CONFIG_BOOTP_* symbols: 1875 1876 CONFIG_BOOTP_SUBNETMASK 1877 CONFIG_BOOTP_GATEWAY 1878 CONFIG_BOOTP_HOSTNAME 1879 CONFIG_BOOTP_NISDOMAIN 1880 CONFIG_BOOTP_BOOTPATH 1881 CONFIG_BOOTP_BOOTFILESIZE 1882 CONFIG_BOOTP_DNS 1883 CONFIG_BOOTP_DNS2 1884 CONFIG_BOOTP_SEND_HOSTNAME 1885 CONFIG_BOOTP_NTPSERVER 1886 CONFIG_BOOTP_TIMEOFFSET 1887 CONFIG_BOOTP_VENDOREX 1888 CONFIG_BOOTP_MAY_FAIL 1889 1890 CONFIG_BOOTP_SERVERIP - TFTP server will be the serverip 1891 environment variable, not the BOOTP server. 1892 1893 CONFIG_BOOTP_MAY_FAIL - If the DHCP server is not found 1894 after the configured retry count, the call will fail 1895 instead of starting over. This can be used to fail over 1896 to Link-local IP address configuration if the DHCP server 1897 is not available. 1898 1899 CONFIG_BOOTP_DNS2 - If a DHCP client requests the DNS 1900 serverip from a DHCP server, it is possible that more 1901 than one DNS serverip is offered to the client. 1902 If CONFIG_BOOTP_DNS2 is enabled, the secondary DNS 1903 serverip will be stored in the additional environment 1904 variable "dnsip2". The first DNS serverip is always 1905 stored in the variable "dnsip", when CONFIG_BOOTP_DNS 1906 is defined. 1907 1908 CONFIG_BOOTP_SEND_HOSTNAME - Some DHCP servers are capable 1909 to do a dynamic update of a DNS server. To do this, they 1910 need the hostname of the DHCP requester. 1911 If CONFIG_BOOTP_SEND_HOSTNAME is defined, the content 1912 of the "hostname" environment variable is passed as 1913 option 12 to the DHCP server. 1914 1915 CONFIG_BOOTP_DHCP_REQUEST_DELAY 1916 1917 A 32bit value in microseconds for a delay between 1918 receiving a "DHCP Offer" and sending the "DHCP Request". 1919 This fixes a problem with certain DHCP servers that don't 1920 respond 100% of the time to a "DHCP request". E.g. On an 1921 AT91RM9200 processor running at 180MHz, this delay needed 1922 to be *at least* 15,000 usec before a Windows Server 2003 1923 DHCP server would reply 100% of the time. I recommend at 1924 least 50,000 usec to be safe. The alternative is to hope 1925 that one of the retries will be successful but note that 1926 the DHCP timeout and retry process takes a longer than 1927 this delay. 1928 1929 - Link-local IP address negotiation: 1930 Negotiate with other link-local clients on the local network 1931 for an address that doesn't require explicit configuration. 1932 This is especially useful if a DHCP server cannot be guaranteed 1933 to exist in all environments that the device must operate. 1934 1935 See doc/README.link-local for more information. 1936 1937 - CDP Options: 1938 CONFIG_CDP_DEVICE_ID 1939 1940 The device id used in CDP trigger frames. 1941 1942 CONFIG_CDP_DEVICE_ID_PREFIX 1943 1944 A two character string which is prefixed to the MAC address 1945 of the device. 1946 1947 CONFIG_CDP_PORT_ID 1948 1949 A printf format string which contains the ascii name of 1950 the port. Normally is set to "eth%d" which sets 1951 eth0 for the first Ethernet, eth1 for the second etc. 1952 1953 CONFIG_CDP_CAPABILITIES 1954 1955 A 32bit integer which indicates the device capabilities; 1956 0x00000010 for a normal host which does not forwards. 1957 1958 CONFIG_CDP_VERSION 1959 1960 An ascii string containing the version of the software. 1961 1962 CONFIG_CDP_PLATFORM 1963 1964 An ascii string containing the name of the platform. 1965 1966 CONFIG_CDP_TRIGGER 1967 1968 A 32bit integer sent on the trigger. 1969 1970 CONFIG_CDP_POWER_CONSUMPTION 1971 1972 A 16bit integer containing the power consumption of the 1973 device in .1 of milliwatts. 1974 1975 CONFIG_CDP_APPLIANCE_VLAN_TYPE 1976 1977 A byte containing the id of the VLAN. 1978 1979- Status LED: CONFIG_LED_STATUS 1980 1981 Several configurations allow to display the current 1982 status using a LED. For instance, the LED will blink 1983 fast while running U-Boot code, stop blinking as 1984 soon as a reply to a BOOTP request was received, and 1985 start blinking slow once the Linux kernel is running 1986 (supported by a status LED driver in the Linux 1987 kernel). Defining CONFIG_LED_STATUS enables this 1988 feature in U-Boot. 1989 1990 Additional options: 1991 1992 CONFIG_LED_STATUS_GPIO 1993 The status LED can be connected to a GPIO pin. 1994 In such cases, the gpio_led driver can be used as a 1995 status LED backend implementation. Define CONFIG_LED_STATUS_GPIO 1996 to include the gpio_led driver in the U-Boot binary. 1997 1998 CONFIG_GPIO_LED_INVERTED_TABLE 1999 Some GPIO connected LEDs may have inverted polarity in which 2000 case the GPIO high value corresponds to LED off state and 2001 GPIO low value corresponds to LED on state. 2002 In such cases CONFIG_GPIO_LED_INVERTED_TABLE may be defined 2003 with a list of GPIO LEDs that have inverted polarity. 2004 2005- CAN Support: CONFIG_CAN_DRIVER 2006 2007 Defining CONFIG_CAN_DRIVER enables CAN driver support 2008 on those systems that support this (optional) 2009 feature, like the TQM8xxL modules. 2010 2011- I2C Support: CONFIG_SYS_I2C 2012 2013 This enable the NEW i2c subsystem, and will allow you to use 2014 i2c commands at the u-boot command line (as long as you set 2015 CONFIG_CMD_I2C in CONFIG_COMMANDS) and communicate with i2c 2016 based realtime clock chips or other i2c devices. See 2017 common/cmd_i2c.c for a description of the command line 2018 interface. 2019 2020 ported i2c driver to the new framework: 2021 - drivers/i2c/soft_i2c.c: 2022 - activate first bus with CONFIG_SYS_I2C_SOFT define 2023 CONFIG_SYS_I2C_SOFT_SPEED and CONFIG_SYS_I2C_SOFT_SLAVE 2024 for defining speed and slave address 2025 - activate second bus with I2C_SOFT_DECLARATIONS2 define 2026 CONFIG_SYS_I2C_SOFT_SPEED_2 and CONFIG_SYS_I2C_SOFT_SLAVE_2 2027 for defining speed and slave address 2028 - activate third bus with I2C_SOFT_DECLARATIONS3 define 2029 CONFIG_SYS_I2C_SOFT_SPEED_3 and CONFIG_SYS_I2C_SOFT_SLAVE_3 2030 for defining speed and slave address 2031 - activate fourth bus with I2C_SOFT_DECLARATIONS4 define 2032 CONFIG_SYS_I2C_SOFT_SPEED_4 and CONFIG_SYS_I2C_SOFT_SLAVE_4 2033 for defining speed and slave address 2034 2035 - drivers/i2c/fsl_i2c.c: 2036 - activate i2c driver with CONFIG_SYS_I2C_FSL 2037 define CONFIG_SYS_FSL_I2C_OFFSET for setting the register 2038 offset CONFIG_SYS_FSL_I2C_SPEED for the i2c speed and 2039 CONFIG_SYS_FSL_I2C_SLAVE for the slave addr of the first 2040 bus. 2041 - If your board supports a second fsl i2c bus, define 2042 CONFIG_SYS_FSL_I2C2_OFFSET for the register offset 2043 CONFIG_SYS_FSL_I2C2_SPEED for the speed and 2044 CONFIG_SYS_FSL_I2C2_SLAVE for the slave address of the 2045 second bus. 2046 2047 - drivers/i2c/tegra_i2c.c: 2048 - activate this driver with CONFIG_SYS_I2C_TEGRA 2049 - This driver adds 4 i2c buses with a fix speed from 2050 100000 and the slave addr 0! 2051 2052 - drivers/i2c/ppc4xx_i2c.c 2053 - activate this driver with CONFIG_SYS_I2C_PPC4XX 2054 - CONFIG_SYS_I2C_PPC4XX_CH0 activate hardware channel 0 2055 - CONFIG_SYS_I2C_PPC4XX_CH1 activate hardware channel 1 2056 2057 - drivers/i2c/i2c_mxc.c 2058 - activate this driver with CONFIG_SYS_I2C_MXC 2059 - enable bus 1 with CONFIG_SYS_I2C_MXC_I2C1 2060 - enable bus 2 with CONFIG_SYS_I2C_MXC_I2C2 2061 - enable bus 3 with CONFIG_SYS_I2C_MXC_I2C3 2062 - enable bus 4 with CONFIG_SYS_I2C_MXC_I2C4 2063 - define speed for bus 1 with CONFIG_SYS_MXC_I2C1_SPEED 2064 - define slave for bus 1 with CONFIG_SYS_MXC_I2C1_SLAVE 2065 - define speed for bus 2 with CONFIG_SYS_MXC_I2C2_SPEED 2066 - define slave for bus 2 with CONFIG_SYS_MXC_I2C2_SLAVE 2067 - define speed for bus 3 with CONFIG_SYS_MXC_I2C3_SPEED 2068 - define slave for bus 3 with CONFIG_SYS_MXC_I2C3_SLAVE 2069 - define speed for bus 4 with CONFIG_SYS_MXC_I2C4_SPEED 2070 - define slave for bus 4 with CONFIG_SYS_MXC_I2C4_SLAVE 2071 If those defines are not set, default value is 100000 2072 for speed, and 0 for slave. 2073 2074 - drivers/i2c/rcar_i2c.c: 2075 - activate this driver with CONFIG_SYS_I2C_RCAR 2076 - This driver adds 4 i2c buses 2077 2078 - CONFIG_SYS_RCAR_I2C0_BASE for setting the register channel 0 2079 - CONFIG_SYS_RCAR_I2C0_SPEED for for the speed channel 0 2080 - CONFIG_SYS_RCAR_I2C1_BASE for setting the register channel 1 2081 - CONFIG_SYS_RCAR_I2C1_SPEED for for the speed channel 1 2082 - CONFIG_SYS_RCAR_I2C2_BASE for setting the register channel 2 2083 - CONFIG_SYS_RCAR_I2C2_SPEED for for the speed channel 2 2084 - CONFIG_SYS_RCAR_I2C3_BASE for setting the register channel 3 2085 - CONFIG_SYS_RCAR_I2C3_SPEED for for the speed channel 3 2086 - CONFIF_SYS_RCAR_I2C_NUM_CONTROLLERS for number of i2c buses 2087 2088 - drivers/i2c/sh_i2c.c: 2089 - activate this driver with CONFIG_SYS_I2C_SH 2090 - This driver adds from 2 to 5 i2c buses 2091 2092 - CONFIG_SYS_I2C_SH_BASE0 for setting the register channel 0 2093 - CONFIG_SYS_I2C_SH_SPEED0 for for the speed channel 0 2094 - CONFIG_SYS_I2C_SH_BASE1 for setting the register channel 1 2095 - CONFIG_SYS_I2C_SH_SPEED1 for for the speed channel 1 2096 - CONFIG_SYS_I2C_SH_BASE2 for setting the register channel 2 2097 - CONFIG_SYS_I2C_SH_SPEED2 for for the speed channel 2 2098 - CONFIG_SYS_I2C_SH_BASE3 for setting the register channel 3 2099 - CONFIG_SYS_I2C_SH_SPEED3 for for the speed channel 3 2100 - CONFIG_SYS_I2C_SH_BASE4 for setting the register channel 4 2101 - CONFIG_SYS_I2C_SH_SPEED4 for for the speed channel 4 2102 - CONFIG_SYS_I2C_SH_NUM_CONTROLLERS for number of i2c buses 2103 2104 - drivers/i2c/omap24xx_i2c.c 2105 - activate this driver with CONFIG_SYS_I2C_OMAP24XX 2106 - CONFIG_SYS_OMAP24_I2C_SPEED speed channel 0 2107 - CONFIG_SYS_OMAP24_I2C_SLAVE slave addr channel 0 2108 - CONFIG_SYS_OMAP24_I2C_SPEED1 speed channel 1 2109 - CONFIG_SYS_OMAP24_I2C_SLAVE1 slave addr channel 1 2110 - CONFIG_SYS_OMAP24_I2C_SPEED2 speed channel 2 2111 - CONFIG_SYS_OMAP24_I2C_SLAVE2 slave addr channel 2 2112 - CONFIG_SYS_OMAP24_I2C_SPEED3 speed channel 3 2113 - CONFIG_SYS_OMAP24_I2C_SLAVE3 slave addr channel 3 2114 - CONFIG_SYS_OMAP24_I2C_SPEED4 speed channel 4 2115 - CONFIG_SYS_OMAP24_I2C_SLAVE4 slave addr channel 4 2116 2117 - drivers/i2c/zynq_i2c.c 2118 - activate this driver with CONFIG_SYS_I2C_ZYNQ 2119 - set CONFIG_SYS_I2C_ZYNQ_SPEED for speed setting 2120 - set CONFIG_SYS_I2C_ZYNQ_SLAVE for slave addr 2121 2122 - drivers/i2c/s3c24x0_i2c.c: 2123 - activate this driver with CONFIG_SYS_I2C_S3C24X0 2124 - This driver adds i2c buses (11 for Exynos5250, Exynos5420 2125 9 i2c buses for Exynos4 and 1 for S3C24X0 SoCs from Samsung) 2126 with a fix speed from 100000 and the slave addr 0! 2127 2128 - drivers/i2c/ihs_i2c.c 2129 - activate this driver with CONFIG_SYS_I2C_IHS 2130 - CONFIG_SYS_I2C_IHS_CH0 activate hardware channel 0 2131 - CONFIG_SYS_I2C_IHS_SPEED_0 speed channel 0 2132 - CONFIG_SYS_I2C_IHS_SLAVE_0 slave addr channel 0 2133 - CONFIG_SYS_I2C_IHS_CH1 activate hardware channel 1 2134 - CONFIG_SYS_I2C_IHS_SPEED_1 speed channel 1 2135 - CONFIG_SYS_I2C_IHS_SLAVE_1 slave addr channel 1 2136 - CONFIG_SYS_I2C_IHS_CH2 activate hardware channel 2 2137 - CONFIG_SYS_I2C_IHS_SPEED_2 speed channel 2 2138 - CONFIG_SYS_I2C_IHS_SLAVE_2 slave addr channel 2 2139 - CONFIG_SYS_I2C_IHS_CH3 activate hardware channel 3 2140 - CONFIG_SYS_I2C_IHS_SPEED_3 speed channel 3 2141 - CONFIG_SYS_I2C_IHS_SLAVE_3 slave addr channel 3 2142 - activate dual channel with CONFIG_SYS_I2C_IHS_DUAL 2143 - CONFIG_SYS_I2C_IHS_SPEED_0_1 speed channel 0_1 2144 - CONFIG_SYS_I2C_IHS_SLAVE_0_1 slave addr channel 0_1 2145 - CONFIG_SYS_I2C_IHS_SPEED_1_1 speed channel 1_1 2146 - CONFIG_SYS_I2C_IHS_SLAVE_1_1 slave addr channel 1_1 2147 - CONFIG_SYS_I2C_IHS_SPEED_2_1 speed channel 2_1 2148 - CONFIG_SYS_I2C_IHS_SLAVE_2_1 slave addr channel 2_1 2149 - CONFIG_SYS_I2C_IHS_SPEED_3_1 speed channel 3_1 2150 - CONFIG_SYS_I2C_IHS_SLAVE_3_1 slave addr channel 3_1 2151 2152 additional defines: 2153 2154 CONFIG_SYS_NUM_I2C_BUSES 2155 Hold the number of i2c buses you want to use. 2156 2157 CONFIG_SYS_I2C_DIRECT_BUS 2158 define this, if you don't use i2c muxes on your hardware. 2159 if CONFIG_SYS_I2C_MAX_HOPS is not defined or == 0 you can 2160 omit this define. 2161 2162 CONFIG_SYS_I2C_MAX_HOPS 2163 define how many muxes are maximal consecutively connected 2164 on one i2c bus. If you not use i2c muxes, omit this 2165 define. 2166 2167 CONFIG_SYS_I2C_BUSES 2168 hold a list of buses you want to use, only used if 2169 CONFIG_SYS_I2C_DIRECT_BUS is not defined, for example 2170 a board with CONFIG_SYS_I2C_MAX_HOPS = 1 and 2171 CONFIG_SYS_NUM_I2C_BUSES = 9: 2172 2173 CONFIG_SYS_I2C_BUSES {{0, {I2C_NULL_HOP}}, \ 2174 {0, {{I2C_MUX_PCA9547, 0x70, 1}}}, \ 2175 {0, {{I2C_MUX_PCA9547, 0x70, 2}}}, \ 2176 {0, {{I2C_MUX_PCA9547, 0x70, 3}}}, \ 2177 {0, {{I2C_MUX_PCA9547, 0x70, 4}}}, \ 2178 {0, {{I2C_MUX_PCA9547, 0x70, 5}}}, \ 2179 {1, {I2C_NULL_HOP}}, \ 2180 {1, {{I2C_MUX_PCA9544, 0x72, 1}}}, \ 2181 {1, {{I2C_MUX_PCA9544, 0x72, 2}}}, \ 2182 } 2183 2184 which defines 2185 bus 0 on adapter 0 without a mux 2186 bus 1 on adapter 0 with a PCA9547 on address 0x70 port 1 2187 bus 2 on adapter 0 with a PCA9547 on address 0x70 port 2 2188 bus 3 on adapter 0 with a PCA9547 on address 0x70 port 3 2189 bus 4 on adapter 0 with a PCA9547 on address 0x70 port 4 2190 bus 5 on adapter 0 with a PCA9547 on address 0x70 port 5 2191 bus 6 on adapter 1 without a mux 2192 bus 7 on adapter 1 with a PCA9544 on address 0x72 port 1 2193 bus 8 on adapter 1 with a PCA9544 on address 0x72 port 2 2194 2195 If you do not have i2c muxes on your board, omit this define. 2196 2197- Legacy I2C Support: 2198 If you use the software i2c interface (CONFIG_SYS_I2C_SOFT) 2199 then the following macros need to be defined (examples are 2200 from include/configs/lwmon.h): 2201 2202 I2C_INIT 2203 2204 (Optional). Any commands necessary to enable the I2C 2205 controller or configure ports. 2206 2207 eg: #define I2C_INIT (immr->im_cpm.cp_pbdir |= PB_SCL) 2208 2209 I2C_PORT 2210 2211 (Only for MPC8260 CPU). The I/O port to use (the code 2212 assumes both bits are on the same port). Valid values 2213 are 0..3 for ports A..D. 2214 2215 I2C_ACTIVE 2216 2217 The code necessary to make the I2C data line active 2218 (driven). If the data line is open collector, this 2219 define can be null. 2220 2221 eg: #define I2C_ACTIVE (immr->im_cpm.cp_pbdir |= PB_SDA) 2222 2223 I2C_TRISTATE 2224 2225 The code necessary to make the I2C data line tri-stated 2226 (inactive). If the data line is open collector, this 2227 define can be null. 2228 2229 eg: #define I2C_TRISTATE (immr->im_cpm.cp_pbdir &= ~PB_SDA) 2230 2231 I2C_READ 2232 2233 Code that returns true if the I2C data line is high, 2234 false if it is low. 2235 2236 eg: #define I2C_READ ((immr->im_cpm.cp_pbdat & PB_SDA) != 0) 2237 2238 I2C_SDA(bit) 2239 2240 If <bit> is true, sets the I2C data line high. If it 2241 is false, it clears it (low). 2242 2243 eg: #define I2C_SDA(bit) \ 2244 if(bit) immr->im_cpm.cp_pbdat |= PB_SDA; \ 2245 else immr->im_cpm.cp_pbdat &= ~PB_SDA 2246 2247 I2C_SCL(bit) 2248 2249 If <bit> is true, sets the I2C clock line high. If it 2250 is false, it clears it (low). 2251 2252 eg: #define I2C_SCL(bit) \ 2253 if(bit) immr->im_cpm.cp_pbdat |= PB_SCL; \ 2254 else immr->im_cpm.cp_pbdat &= ~PB_SCL 2255 2256 I2C_DELAY 2257 2258 This delay is invoked four times per clock cycle so this 2259 controls the rate of data transfer. The data rate thus 2260 is 1 / (I2C_DELAY * 4). Often defined to be something 2261 like: 2262 2263 #define I2C_DELAY udelay(2) 2264 2265 CONFIG_SOFT_I2C_GPIO_SCL / CONFIG_SOFT_I2C_GPIO_SDA 2266 2267 If your arch supports the generic GPIO framework (asm/gpio.h), 2268 then you may alternatively define the two GPIOs that are to be 2269 used as SCL / SDA. Any of the previous I2C_xxx macros will 2270 have GPIO-based defaults assigned to them as appropriate. 2271 2272 You should define these to the GPIO value as given directly to 2273 the generic GPIO functions. 2274 2275 CONFIG_SYS_I2C_INIT_BOARD 2276 2277 When a board is reset during an i2c bus transfer 2278 chips might think that the current transfer is still 2279 in progress. On some boards it is possible to access 2280 the i2c SCLK line directly, either by using the 2281 processor pin as a GPIO or by having a second pin 2282 connected to the bus. If this option is defined a 2283 custom i2c_init_board() routine in boards/xxx/board.c 2284 is run early in the boot sequence. 2285 2286 CONFIG_I2C_MULTI_BUS 2287 2288 This option allows the use of multiple I2C buses, each of which 2289 must have a controller. At any point in time, only one bus is 2290 active. To switch to a different bus, use the 'i2c dev' command. 2291 Note that bus numbering is zero-based. 2292 2293 CONFIG_SYS_I2C_NOPROBES 2294 2295 This option specifies a list of I2C devices that will be skipped 2296 when the 'i2c probe' command is issued. If CONFIG_I2C_MULTI_BUS 2297 is set, specify a list of bus-device pairs. Otherwise, specify 2298 a 1D array of device addresses 2299 2300 e.g. 2301 #undef CONFIG_I2C_MULTI_BUS 2302 #define CONFIG_SYS_I2C_NOPROBES {0x50,0x68} 2303 2304 will skip addresses 0x50 and 0x68 on a board with one I2C bus 2305 2306 #define CONFIG_I2C_MULTI_BUS 2307 #define CONFIG_SYS_I2C_NOPROBES {{0,0x50},{0,0x68},{1,0x54}} 2308 2309 will skip addresses 0x50 and 0x68 on bus 0 and address 0x54 on bus 1 2310 2311 CONFIG_SYS_SPD_BUS_NUM 2312 2313 If defined, then this indicates the I2C bus number for DDR SPD. 2314 If not defined, then U-Boot assumes that SPD is on I2C bus 0. 2315 2316 CONFIG_SYS_RTC_BUS_NUM 2317 2318 If defined, then this indicates the I2C bus number for the RTC. 2319 If not defined, then U-Boot assumes that RTC is on I2C bus 0. 2320 2321 CONFIG_SOFT_I2C_READ_REPEATED_START 2322 2323 defining this will force the i2c_read() function in 2324 the soft_i2c driver to perform an I2C repeated start 2325 between writing the address pointer and reading the 2326 data. If this define is omitted the default behaviour 2327 of doing a stop-start sequence will be used. Most I2C 2328 devices can use either method, but some require one or 2329 the other. 2330 2331- SPI Support: CONFIG_SPI 2332 2333 Enables SPI driver (so far only tested with 2334 SPI EEPROM, also an instance works with Crystal A/D and 2335 D/As on the SACSng board) 2336 2337 CONFIG_SH_SPI 2338 2339 Enables the driver for SPI controller on SuperH. Currently 2340 only SH7757 is supported. 2341 2342 CONFIG_SOFT_SPI 2343 2344 Enables a software (bit-bang) SPI driver rather than 2345 using hardware support. This is a general purpose 2346 driver that only requires three general I/O port pins 2347 (two outputs, one input) to function. If this is 2348 defined, the board configuration must define several 2349 SPI configuration items (port pins to use, etc). For 2350 an example, see include/configs/sacsng.h. 2351 2352 CONFIG_HARD_SPI 2353 2354 Enables a hardware SPI driver for general-purpose reads 2355 and writes. As with CONFIG_SOFT_SPI, the board configuration 2356 must define a list of chip-select function pointers. 2357 Currently supported on some MPC8xxx processors. For an 2358 example, see include/configs/mpc8349emds.h. 2359 2360 CONFIG_MXC_SPI 2361 2362 Enables the driver for the SPI controllers on i.MX and MXC 2363 SoCs. Currently i.MX31/35/51 are supported. 2364 2365 CONFIG_SYS_SPI_MXC_WAIT 2366 Timeout for waiting until spi transfer completed. 2367 default: (CONFIG_SYS_HZ/100) /* 10 ms */ 2368 2369- FPGA Support: CONFIG_FPGA 2370 2371 Enables FPGA subsystem. 2372 2373 CONFIG_FPGA_<vendor> 2374 2375 Enables support for specific chip vendors. 2376 (ALTERA, XILINX) 2377 2378 CONFIG_FPGA_<family> 2379 2380 Enables support for FPGA family. 2381 (SPARTAN2, SPARTAN3, VIRTEX2, CYCLONE2, ACEX1K, ACEX) 2382 2383 CONFIG_FPGA_COUNT 2384 2385 Specify the number of FPGA devices to support. 2386 2387 CONFIG_SYS_FPGA_PROG_FEEDBACK 2388 2389 Enable printing of hash marks during FPGA configuration. 2390 2391 CONFIG_SYS_FPGA_CHECK_BUSY 2392 2393 Enable checks on FPGA configuration interface busy 2394 status by the configuration function. This option 2395 will require a board or device specific function to 2396 be written. 2397 2398 CONFIG_FPGA_DELAY 2399 2400 If defined, a function that provides delays in the FPGA 2401 configuration driver. 2402 2403 CONFIG_SYS_FPGA_CHECK_CTRLC 2404 Allow Control-C to interrupt FPGA configuration 2405 2406 CONFIG_SYS_FPGA_CHECK_ERROR 2407 2408 Check for configuration errors during FPGA bitfile 2409 loading. For example, abort during Virtex II 2410 configuration if the INIT_B line goes low (which 2411 indicated a CRC error). 2412 2413 CONFIG_SYS_FPGA_WAIT_INIT 2414 2415 Maximum time to wait for the INIT_B line to de-assert 2416 after PROB_B has been de-asserted during a Virtex II 2417 FPGA configuration sequence. The default time is 500 2418 ms. 2419 2420 CONFIG_SYS_FPGA_WAIT_BUSY 2421 2422 Maximum time to wait for BUSY to de-assert during 2423 Virtex II FPGA configuration. The default is 5 ms. 2424 2425 CONFIG_SYS_FPGA_WAIT_CONFIG 2426 2427 Time to wait after FPGA configuration. The default is 2428 200 ms. 2429 2430- Configuration Management: 2431 CONFIG_BUILD_TARGET 2432 2433 Some SoCs need special image types (e.g. U-Boot binary 2434 with a special header) as build targets. By defining 2435 CONFIG_BUILD_TARGET in the SoC / board header, this 2436 special image will be automatically built upon calling 2437 make / buildman. 2438 2439 CONFIG_IDENT_STRING 2440 2441 If defined, this string will be added to the U-Boot 2442 version information (U_BOOT_VERSION) 2443 2444- Vendor Parameter Protection: 2445 2446 U-Boot considers the values of the environment 2447 variables "serial#" (Board Serial Number) and 2448 "ethaddr" (Ethernet Address) to be parameters that 2449 are set once by the board vendor / manufacturer, and 2450 protects these variables from casual modification by 2451 the user. Once set, these variables are read-only, 2452 and write or delete attempts are rejected. You can 2453 change this behaviour: 2454 2455 If CONFIG_ENV_OVERWRITE is #defined in your config 2456 file, the write protection for vendor parameters is 2457 completely disabled. Anybody can change or delete 2458 these parameters. 2459 2460 Alternatively, if you define _both_ an ethaddr in the 2461 default env _and_ CONFIG_OVERWRITE_ETHADDR_ONCE, a default 2462 Ethernet address is installed in the environment, 2463 which can be changed exactly ONCE by the user. [The 2464 serial# is unaffected by this, i. e. it remains 2465 read-only.] 2466 2467 The same can be accomplished in a more flexible way 2468 for any variable by configuring the type of access 2469 to allow for those variables in the ".flags" variable 2470 or define CONFIG_ENV_FLAGS_LIST_STATIC. 2471 2472- Protected RAM: 2473 CONFIG_PRAM 2474 2475 Define this variable to enable the reservation of 2476 "protected RAM", i. e. RAM which is not overwritten 2477 by U-Boot. Define CONFIG_PRAM to hold the number of 2478 kB you want to reserve for pRAM. You can overwrite 2479 this default value by defining an environment 2480 variable "pram" to the number of kB you want to 2481 reserve. Note that the board info structure will 2482 still show the full amount of RAM. If pRAM is 2483 reserved, a new environment variable "mem" will 2484 automatically be defined to hold the amount of 2485 remaining RAM in a form that can be passed as boot 2486 argument to Linux, for instance like that: 2487 2488 setenv bootargs ... mem=\${mem} 2489 saveenv 2490 2491 This way you can tell Linux not to use this memory, 2492 either, which results in a memory region that will 2493 not be affected by reboots. 2494 2495 *WARNING* If your board configuration uses automatic 2496 detection of the RAM size, you must make sure that 2497 this memory test is non-destructive. So far, the 2498 following board configurations are known to be 2499 "pRAM-clean": 2500 2501 IVMS8, IVML24, SPD8xx, TQM8xxL, 2502 HERMES, IP860, RPXlite, LWMON, 2503 FLAGADM, TQM8260 2504 2505- Access to physical memory region (> 4GB) 2506 Some basic support is provided for operations on memory not 2507 normally accessible to U-Boot - e.g. some architectures 2508 support access to more than 4GB of memory on 32-bit 2509 machines using physical address extension or similar. 2510 Define CONFIG_PHYSMEM to access this basic support, which 2511 currently only supports clearing the memory. 2512 2513- Error Recovery: 2514 CONFIG_PANIC_HANG 2515 2516 Define this variable to stop the system in case of a 2517 fatal error, so that you have to reset it manually. 2518 This is probably NOT a good idea for an embedded 2519 system where you want the system to reboot 2520 automatically as fast as possible, but it may be 2521 useful during development since you can try to debug 2522 the conditions that lead to the situation. 2523 2524 CONFIG_NET_RETRY_COUNT 2525 2526 This variable defines the number of retries for 2527 network operations like ARP, RARP, TFTP, or BOOTP 2528 before giving up the operation. If not defined, a 2529 default value of 5 is used. 2530 2531 CONFIG_ARP_TIMEOUT 2532 2533 Timeout waiting for an ARP reply in milliseconds. 2534 2535 CONFIG_NFS_TIMEOUT 2536 2537 Timeout in milliseconds used in NFS protocol. 2538 If you encounter "ERROR: Cannot umount" in nfs command, 2539 try longer timeout such as 2540 #define CONFIG_NFS_TIMEOUT 10000UL 2541 2542- Command Interpreter: 2543 CONFIG_AUTO_COMPLETE 2544 2545 Enable auto completion of commands using TAB. 2546 2547 CONFIG_SYS_PROMPT_HUSH_PS2 2548 2549 This defines the secondary prompt string, which is 2550 printed when the command interpreter needs more input 2551 to complete a command. Usually "> ". 2552 2553 Note: 2554 2555 In the current implementation, the local variables 2556 space and global environment variables space are 2557 separated. Local variables are those you define by 2558 simply typing `name=value'. To access a local 2559 variable later on, you have write `$name' or 2560 `${name}'; to execute the contents of a variable 2561 directly type `$name' at the command prompt. 2562 2563 Global environment variables are those you use 2564 setenv/printenv to work with. To run a command stored 2565 in such a variable, you need to use the run command, 2566 and you must not use the '$' sign to access them. 2567 2568 To store commands and special characters in a 2569 variable, please use double quotation marks 2570 surrounding the whole text of the variable, instead 2571 of the backslashes before semicolons and special 2572 symbols. 2573 2574- Command Line Editing and History: 2575 CONFIG_CMDLINE_EDITING 2576 2577 Enable editing and History functions for interactive 2578 command line input operations 2579 2580- Command Line PS1/PS2 support: 2581 CONFIG_CMDLINE_PS_SUPPORT 2582 2583 Enable support for changing the command prompt string 2584 at run-time. Only static string is supported so far. 2585 The string is obtained from environment variables PS1 2586 and PS2. 2587 2588- Default Environment: 2589 CONFIG_EXTRA_ENV_SETTINGS 2590 2591 Define this to contain any number of null terminated 2592 strings (variable = value pairs) that will be part of 2593 the default environment compiled into the boot image. 2594 2595 For example, place something like this in your 2596 board's config file: 2597 2598 #define CONFIG_EXTRA_ENV_SETTINGS \ 2599 "myvar1=value1\0" \ 2600 "myvar2=value2\0" 2601 2602 Warning: This method is based on knowledge about the 2603 internal format how the environment is stored by the 2604 U-Boot code. This is NOT an official, exported 2605 interface! Although it is unlikely that this format 2606 will change soon, there is no guarantee either. 2607 You better know what you are doing here. 2608 2609 Note: overly (ab)use of the default environment is 2610 discouraged. Make sure to check other ways to preset 2611 the environment like the "source" command or the 2612 boot command first. 2613 2614 CONFIG_ENV_VARS_UBOOT_CONFIG 2615 2616 Define this in order to add variables describing the 2617 U-Boot build configuration to the default environment. 2618 These will be named arch, cpu, board, vendor, and soc. 2619 2620 Enabling this option will cause the following to be defined: 2621 2622 - CONFIG_SYS_ARCH 2623 - CONFIG_SYS_CPU 2624 - CONFIG_SYS_BOARD 2625 - CONFIG_SYS_VENDOR 2626 - CONFIG_SYS_SOC 2627 2628 CONFIG_ENV_VARS_UBOOT_RUNTIME_CONFIG 2629 2630 Define this in order to add variables describing certain 2631 run-time determined information about the hardware to the 2632 environment. These will be named board_name, board_rev. 2633 2634 CONFIG_DELAY_ENVIRONMENT 2635 2636 Normally the environment is loaded when the board is 2637 initialised so that it is available to U-Boot. This inhibits 2638 that so that the environment is not available until 2639 explicitly loaded later by U-Boot code. With CONFIG_OF_CONTROL 2640 this is instead controlled by the value of 2641 /config/load-environment. 2642 2643- DataFlash Support: 2644 CONFIG_HAS_DATAFLASH 2645 2646 Defining this option enables DataFlash features and 2647 allows to read/write in Dataflash via the standard 2648 commands cp, md... 2649 2650- Serial Flash support 2651 CONFIG_CMD_SF 2652 2653 Defining this option enables SPI flash commands 2654 'sf probe/read/write/erase/update'. 2655 2656 Usage requires an initial 'probe' to define the serial 2657 flash parameters, followed by read/write/erase/update 2658 commands. 2659 2660 The following defaults may be provided by the platform 2661 to handle the common case when only a single serial 2662 flash is present on the system. 2663 2664 CONFIG_SF_DEFAULT_BUS Bus identifier 2665 CONFIG_SF_DEFAULT_CS Chip-select 2666 CONFIG_SF_DEFAULT_MODE (see include/spi.h) 2667 CONFIG_SF_DEFAULT_SPEED in Hz 2668 2669 CONFIG_CMD_SF_TEST 2670 2671 Define this option to include a destructive SPI flash 2672 test ('sf test'). 2673 2674 CONFIG_SF_DUAL_FLASH Dual flash memories 2675 2676 Define this option to use dual flash support where two flash 2677 memories can be connected with a given cs line. 2678 Currently Xilinx Zynq qspi supports these type of connections. 2679 2680- SystemACE Support: 2681 CONFIG_SYSTEMACE 2682 2683 Adding this option adds support for Xilinx SystemACE 2684 chips attached via some sort of local bus. The address 2685 of the chip must also be defined in the 2686 CONFIG_SYS_SYSTEMACE_BASE macro. For example: 2687 2688 #define CONFIG_SYSTEMACE 2689 #define CONFIG_SYS_SYSTEMACE_BASE 0xf0000000 2690 2691 When SystemACE support is added, the "ace" device type 2692 becomes available to the fat commands, i.e. fatls. 2693 2694- TFTP Fixed UDP Port: 2695 CONFIG_TFTP_PORT 2696 2697 If this is defined, the environment variable tftpsrcp 2698 is used to supply the TFTP UDP source port value. 2699 If tftpsrcp isn't defined, the normal pseudo-random port 2700 number generator is used. 2701 2702 Also, the environment variable tftpdstp is used to supply 2703 the TFTP UDP destination port value. If tftpdstp isn't 2704 defined, the normal port 69 is used. 2705 2706 The purpose for tftpsrcp is to allow a TFTP server to 2707 blindly start the TFTP transfer using the pre-configured 2708 target IP address and UDP port. This has the effect of 2709 "punching through" the (Windows XP) firewall, allowing 2710 the remainder of the TFTP transfer to proceed normally. 2711 A better solution is to properly configure the firewall, 2712 but sometimes that is not allowed. 2713 2714- Hashing support: 2715 CONFIG_CMD_HASH 2716 2717 This enables a generic 'hash' command which can produce 2718 hashes / digests from a few algorithms (e.g. SHA1, SHA256). 2719 2720 CONFIG_HASH_VERIFY 2721 2722 Enable the hash verify command (hash -v). This adds to code 2723 size a little. 2724 2725 Note: There is also a sha1sum command, which should perhaps 2726 be deprecated in favour of 'hash sha1'. 2727 2728- Freescale i.MX specific commands: 2729 CONFIG_CMD_HDMIDETECT 2730 This enables 'hdmidet' command which returns true if an 2731 HDMI monitor is detected. This command is i.MX 6 specific. 2732 2733- bootcount support: 2734 CONFIG_BOOTCOUNT_LIMIT 2735 2736 This enables the bootcounter support, see: 2737 http://www.denx.de/wiki/DULG/UBootBootCountLimit 2738 2739 CONFIG_AT91SAM9XE 2740 enable special bootcounter support on at91sam9xe based boards. 2741 CONFIG_SOC_DA8XX 2742 enable special bootcounter support on da850 based boards. 2743 CONFIG_BOOTCOUNT_RAM 2744 enable support for the bootcounter in RAM 2745 CONFIG_BOOTCOUNT_I2C 2746 enable support for the bootcounter on an i2c (like RTC) device. 2747 CONFIG_SYS_I2C_RTC_ADDR = i2c chip address 2748 CONFIG_SYS_BOOTCOUNT_ADDR = i2c addr which is used for 2749 the bootcounter. 2750 CONFIG_BOOTCOUNT_ALEN = address len 2751 2752- Show boot progress: 2753 CONFIG_SHOW_BOOT_PROGRESS 2754 2755 Defining this option allows to add some board- 2756 specific code (calling a user-provided function 2757 "show_boot_progress(int)") that enables you to show 2758 the system's boot progress on some display (for 2759 example, some LED's) on your board. At the moment, 2760 the following checkpoints are implemented: 2761 2762 2763Legacy uImage format: 2764 2765 Arg Where When 2766 1 common/cmd_bootm.c before attempting to boot an image 2767 -1 common/cmd_bootm.c Image header has bad magic number 2768 2 common/cmd_bootm.c Image header has correct magic number 2769 -2 common/cmd_bootm.c Image header has bad checksum 2770 3 common/cmd_bootm.c Image header has correct checksum 2771 -3 common/cmd_bootm.c Image data has bad checksum 2772 4 common/cmd_bootm.c Image data has correct checksum 2773 -4 common/cmd_bootm.c Image is for unsupported architecture 2774 5 common/cmd_bootm.c Architecture check OK 2775 -5 common/cmd_bootm.c Wrong Image Type (not kernel, multi) 2776 6 common/cmd_bootm.c Image Type check OK 2777 -6 common/cmd_bootm.c gunzip uncompression error 2778 -7 common/cmd_bootm.c Unimplemented compression type 2779 7 common/cmd_bootm.c Uncompression OK 2780 8 common/cmd_bootm.c No uncompress/copy overwrite error 2781 -9 common/cmd_bootm.c Unsupported OS (not Linux, BSD, VxWorks, QNX) 2782 2783 9 common/image.c Start initial ramdisk verification 2784 -10 common/image.c Ramdisk header has bad magic number 2785 -11 common/image.c Ramdisk header has bad checksum 2786 10 common/image.c Ramdisk header is OK 2787 -12 common/image.c Ramdisk data has bad checksum 2788 11 common/image.c Ramdisk data has correct checksum 2789 12 common/image.c Ramdisk verification complete, start loading 2790 -13 common/image.c Wrong Image Type (not PPC Linux ramdisk) 2791 13 common/image.c Start multifile image verification 2792 14 common/image.c No initial ramdisk, no multifile, continue. 2793 2794 15 arch/<arch>/lib/bootm.c All preparation done, transferring control to OS 2795 2796 -30 arch/powerpc/lib/board.c Fatal error, hang the system 2797 -31 post/post.c POST test failed, detected by post_output_backlog() 2798 -32 post/post.c POST test failed, detected by post_run_single() 2799 2800 34 common/cmd_doc.c before loading a Image from a DOC device 2801 -35 common/cmd_doc.c Bad usage of "doc" command 2802 35 common/cmd_doc.c correct usage of "doc" command 2803 -36 common/cmd_doc.c No boot device 2804 36 common/cmd_doc.c correct boot device 2805 -37 common/cmd_doc.c Unknown Chip ID on boot device 2806 37 common/cmd_doc.c correct chip ID found, device available 2807 -38 common/cmd_doc.c Read Error on boot device 2808 38 common/cmd_doc.c reading Image header from DOC device OK 2809 -39 common/cmd_doc.c Image header has bad magic number 2810 39 common/cmd_doc.c Image header has correct magic number 2811 -40 common/cmd_doc.c Error reading Image from DOC device 2812 40 common/cmd_doc.c Image header has correct magic number 2813 41 common/cmd_ide.c before loading a Image from a IDE device 2814 -42 common/cmd_ide.c Bad usage of "ide" command 2815 42 common/cmd_ide.c correct usage of "ide" command 2816 -43 common/cmd_ide.c No boot device 2817 43 common/cmd_ide.c boot device found 2818 -44 common/cmd_ide.c Device not available 2819 44 common/cmd_ide.c Device available 2820 -45 common/cmd_ide.c wrong partition selected 2821 45 common/cmd_ide.c partition selected 2822 -46 common/cmd_ide.c Unknown partition table 2823 46 common/cmd_ide.c valid partition table found 2824 -47 common/cmd_ide.c Invalid partition type 2825 47 common/cmd_ide.c correct partition type 2826 -48 common/cmd_ide.c Error reading Image Header on boot device 2827 48 common/cmd_ide.c reading Image Header from IDE device OK 2828 -49 common/cmd_ide.c Image header has bad magic number 2829 49 common/cmd_ide.c Image header has correct magic number 2830 -50 common/cmd_ide.c Image header has bad checksum 2831 50 common/cmd_ide.c Image header has correct checksum 2832 -51 common/cmd_ide.c Error reading Image from IDE device 2833 51 common/cmd_ide.c reading Image from IDE device OK 2834 52 common/cmd_nand.c before loading a Image from a NAND device 2835 -53 common/cmd_nand.c Bad usage of "nand" command 2836 53 common/cmd_nand.c correct usage of "nand" command 2837 -54 common/cmd_nand.c No boot device 2838 54 common/cmd_nand.c boot device found 2839 -55 common/cmd_nand.c Unknown Chip ID on boot device 2840 55 common/cmd_nand.c correct chip ID found, device available 2841 -56 common/cmd_nand.c Error reading Image Header on boot device 2842 56 common/cmd_nand.c reading Image Header from NAND device OK 2843 -57 common/cmd_nand.c Image header has bad magic number 2844 57 common/cmd_nand.c Image header has correct magic number 2845 -58 common/cmd_nand.c Error reading Image from NAND device 2846 58 common/cmd_nand.c reading Image from NAND device OK 2847 2848 -60 common/env_common.c Environment has a bad CRC, using default 2849 2850 64 net/eth.c starting with Ethernet configuration. 2851 -64 net/eth.c no Ethernet found. 2852 65 net/eth.c Ethernet found. 2853 2854 -80 common/cmd_net.c usage wrong 2855 80 common/cmd_net.c before calling net_loop() 2856 -81 common/cmd_net.c some error in net_loop() occurred 2857 81 common/cmd_net.c net_loop() back without error 2858 -82 common/cmd_net.c size == 0 (File with size 0 loaded) 2859 82 common/cmd_net.c trying automatic boot 2860 83 common/cmd_net.c running "source" command 2861 -83 common/cmd_net.c some error in automatic boot or "source" command 2862 84 common/cmd_net.c end without errors 2863 2864FIT uImage format: 2865 2866 Arg Where When 2867 100 common/cmd_bootm.c Kernel FIT Image has correct format 2868 -100 common/cmd_bootm.c Kernel FIT Image has incorrect format 2869 101 common/cmd_bootm.c No Kernel subimage unit name, using configuration 2870 -101 common/cmd_bootm.c Can't get configuration for kernel subimage 2871 102 common/cmd_bootm.c Kernel unit name specified 2872 -103 common/cmd_bootm.c Can't get kernel subimage node offset 2873 103 common/cmd_bootm.c Found configuration node 2874 104 common/cmd_bootm.c Got kernel subimage node offset 2875 -104 common/cmd_bootm.c Kernel subimage hash verification failed 2876 105 common/cmd_bootm.c Kernel subimage hash verification OK 2877 -105 common/cmd_bootm.c Kernel subimage is for unsupported architecture 2878 106 common/cmd_bootm.c Architecture check OK 2879 -106 common/cmd_bootm.c Kernel subimage has wrong type 2880 107 common/cmd_bootm.c Kernel subimage type OK 2881 -107 common/cmd_bootm.c Can't get kernel subimage data/size 2882 108 common/cmd_bootm.c Got kernel subimage data/size 2883 -108 common/cmd_bootm.c Wrong image type (not legacy, FIT) 2884 -109 common/cmd_bootm.c Can't get kernel subimage type 2885 -110 common/cmd_bootm.c Can't get kernel subimage comp 2886 -111 common/cmd_bootm.c Can't get kernel subimage os 2887 -112 common/cmd_bootm.c Can't get kernel subimage load address 2888 -113 common/cmd_bootm.c Image uncompress/copy overwrite error 2889 2890 120 common/image.c Start initial ramdisk verification 2891 -120 common/image.c Ramdisk FIT image has incorrect format 2892 121 common/image.c Ramdisk FIT image has correct format 2893 122 common/image.c No ramdisk subimage unit name, using configuration 2894 -122 common/image.c Can't get configuration for ramdisk subimage 2895 123 common/image.c Ramdisk unit name specified 2896 -124 common/image.c Can't get ramdisk subimage node offset 2897 125 common/image.c Got ramdisk subimage node offset 2898 -125 common/image.c Ramdisk subimage hash verification failed 2899 126 common/image.c Ramdisk subimage hash verification OK 2900 -126 common/image.c Ramdisk subimage for unsupported architecture 2901 127 common/image.c Architecture check OK 2902 -127 common/image.c Can't get ramdisk subimage data/size 2903 128 common/image.c Got ramdisk subimage data/size 2904 129 common/image.c Can't get ramdisk load address 2905 -129 common/image.c Got ramdisk load address 2906 2907 -130 common/cmd_doc.c Incorrect FIT image format 2908 131 common/cmd_doc.c FIT image format OK 2909 2910 -140 common/cmd_ide.c Incorrect FIT image format 2911 141 common/cmd_ide.c FIT image format OK 2912 2913 -150 common/cmd_nand.c Incorrect FIT image format 2914 151 common/cmd_nand.c FIT image format OK 2915 2916- legacy image format: 2917 CONFIG_IMAGE_FORMAT_LEGACY 2918 enables the legacy image format support in U-Boot. 2919 2920 Default: 2921 enabled if CONFIG_FIT_SIGNATURE is not defined. 2922 2923 CONFIG_DISABLE_IMAGE_LEGACY 2924 disable the legacy image format 2925 2926 This define is introduced, as the legacy image format is 2927 enabled per default for backward compatibility. 2928 2929- Standalone program support: 2930 CONFIG_STANDALONE_LOAD_ADDR 2931 2932 This option defines a board specific value for the 2933 address where standalone program gets loaded, thus 2934 overwriting the architecture dependent default 2935 settings. 2936 2937- Frame Buffer Address: 2938 CONFIG_FB_ADDR 2939 2940 Define CONFIG_FB_ADDR if you want to use specific 2941 address for frame buffer. This is typically the case 2942 when using a graphics controller has separate video 2943 memory. U-Boot will then place the frame buffer at 2944 the given address instead of dynamically reserving it 2945 in system RAM by calling lcd_setmem(), which grabs 2946 the memory for the frame buffer depending on the 2947 configured panel size. 2948 2949 Please see board_init_f function. 2950 2951- Automatic software updates via TFTP server 2952 CONFIG_UPDATE_TFTP 2953 CONFIG_UPDATE_TFTP_CNT_MAX 2954 CONFIG_UPDATE_TFTP_MSEC_MAX 2955 2956 These options enable and control the auto-update feature; 2957 for a more detailed description refer to doc/README.update. 2958 2959- MTD Support (mtdparts command, UBI support) 2960 CONFIG_MTD_DEVICE 2961 2962 Adds the MTD device infrastructure from the Linux kernel. 2963 Needed for mtdparts command support. 2964 2965 CONFIG_MTD_PARTITIONS 2966 2967 Adds the MTD partitioning infrastructure from the Linux 2968 kernel. Needed for UBI support. 2969 2970- UBI support 2971 CONFIG_CMD_UBI 2972 2973 Adds commands for interacting with MTD partitions formatted 2974 with the UBI flash translation layer 2975 2976 Requires also defining CONFIG_RBTREE 2977 2978 CONFIG_UBI_SILENCE_MSG 2979 2980 Make the verbose messages from UBI stop printing. This leaves 2981 warnings and errors enabled. 2982 2983 2984 CONFIG_MTD_UBI_WL_THRESHOLD 2985 This parameter defines the maximum difference between the highest 2986 erase counter value and the lowest erase counter value of eraseblocks 2987 of UBI devices. When this threshold is exceeded, UBI starts performing 2988 wear leveling by means of moving data from eraseblock with low erase 2989 counter to eraseblocks with high erase counter. 2990 2991 The default value should be OK for SLC NAND flashes, NOR flashes and 2992 other flashes which have eraseblock life-cycle 100000 or more. 2993 However, in case of MLC NAND flashes which typically have eraseblock 2994 life-cycle less than 10000, the threshold should be lessened (e.g., 2995 to 128 or 256, although it does not have to be power of 2). 2996 2997 default: 4096 2998 2999 CONFIG_MTD_UBI_BEB_LIMIT 3000 This option specifies the maximum bad physical eraseblocks UBI 3001 expects on the MTD device (per 1024 eraseblocks). If the 3002 underlying flash does not admit of bad eraseblocks (e.g. NOR 3003 flash), this value is ignored. 3004 3005 NAND datasheets often specify the minimum and maximum NVM 3006 (Number of Valid Blocks) for the flashes' endurance lifetime. 3007 The maximum expected bad eraseblocks per 1024 eraseblocks 3008 then can be calculated as "1024 * (1 - MinNVB / MaxNVB)", 3009 which gives 20 for most NANDs (MaxNVB is basically the total 3010 count of eraseblocks on the chip). 3011 3012 To put it differently, if this value is 20, UBI will try to 3013 reserve about 1.9% of physical eraseblocks for bad blocks 3014 handling. And that will be 1.9% of eraseblocks on the entire 3015 NAND chip, not just the MTD partition UBI attaches. This means 3016 that if you have, say, a NAND flash chip admits maximum 40 bad 3017 eraseblocks, and it is split on two MTD partitions of the same 3018 size, UBI will reserve 40 eraseblocks when attaching a 3019 partition. 3020 3021 default: 20 3022 3023 CONFIG_MTD_UBI_FASTMAP 3024 Fastmap is a mechanism which allows attaching an UBI device 3025 in nearly constant time. Instead of scanning the whole MTD device it 3026 only has to locate a checkpoint (called fastmap) on the device. 3027 The on-flash fastmap contains all information needed to attach 3028 the device. Using fastmap makes only sense on large devices where 3029 attaching by scanning takes long. UBI will not automatically install 3030 a fastmap on old images, but you can set the UBI parameter 3031 CONFIG_MTD_UBI_FASTMAP_AUTOCONVERT to 1 if you want so. Please note 3032 that fastmap-enabled images are still usable with UBI implementations 3033 without fastmap support. On typical flash devices the whole fastmap 3034 fits into one PEB. UBI will reserve PEBs to hold two fastmaps. 3035 3036 CONFIG_MTD_UBI_FASTMAP_AUTOCONVERT 3037 Set this parameter to enable fastmap automatically on images 3038 without a fastmap. 3039 default: 0 3040 3041 CONFIG_MTD_UBI_FM_DEBUG 3042 Enable UBI fastmap debug 3043 default: 0 3044 3045- UBIFS support 3046 CONFIG_CMD_UBIFS 3047 3048 Adds commands for interacting with UBI volumes formatted as 3049 UBIFS. UBIFS is read-only in u-boot. 3050 3051 Requires UBI support as well as CONFIG_LZO 3052 3053 CONFIG_UBIFS_SILENCE_MSG 3054 3055 Make the verbose messages from UBIFS stop printing. This leaves 3056 warnings and errors enabled. 3057 3058- SPL framework 3059 CONFIG_SPL 3060 Enable building of SPL globally. 3061 3062 CONFIG_SPL_LDSCRIPT 3063 LDSCRIPT for linking the SPL binary. 3064 3065 CONFIG_SPL_MAX_FOOTPRINT 3066 Maximum size in memory allocated to the SPL, BSS included. 3067 When defined, the linker checks that the actual memory 3068 used by SPL from _start to __bss_end does not exceed it. 3069 CONFIG_SPL_MAX_FOOTPRINT and CONFIG_SPL_BSS_MAX_SIZE 3070 must not be both defined at the same time. 3071 3072 CONFIG_SPL_MAX_SIZE 3073 Maximum size of the SPL image (text, data, rodata, and 3074 linker lists sections), BSS excluded. 3075 When defined, the linker checks that the actual size does 3076 not exceed it. 3077 3078 CONFIG_SPL_TEXT_BASE 3079 TEXT_BASE for linking the SPL binary. 3080 3081 CONFIG_SPL_RELOC_TEXT_BASE 3082 Address to relocate to. If unspecified, this is equal to 3083 CONFIG_SPL_TEXT_BASE (i.e. no relocation is done). 3084 3085 CONFIG_SPL_BSS_START_ADDR 3086 Link address for the BSS within the SPL binary. 3087 3088 CONFIG_SPL_BSS_MAX_SIZE 3089 Maximum size in memory allocated to the SPL BSS. 3090 When defined, the linker checks that the actual memory used 3091 by SPL from __bss_start to __bss_end does not exceed it. 3092 CONFIG_SPL_MAX_FOOTPRINT and CONFIG_SPL_BSS_MAX_SIZE 3093 must not be both defined at the same time. 3094 3095 CONFIG_SPL_STACK 3096 Adress of the start of the stack SPL will use 3097 3098 CONFIG_SPL_PANIC_ON_RAW_IMAGE 3099 When defined, SPL will panic() if the image it has 3100 loaded does not have a signature. 3101 Defining this is useful when code which loads images 3102 in SPL cannot guarantee that absolutely all read errors 3103 will be caught. 3104 An example is the LPC32XX MLC NAND driver, which will 3105 consider that a completely unreadable NAND block is bad, 3106 and thus should be skipped silently. 3107 3108 CONFIG_SPL_RELOC_STACK 3109 Adress of the start of the stack SPL will use after 3110 relocation. If unspecified, this is equal to 3111 CONFIG_SPL_STACK. 3112 3113 CONFIG_SYS_SPL_MALLOC_START 3114 Starting address of the malloc pool used in SPL. 3115 When this option is set the full malloc is used in SPL and 3116 it is set up by spl_init() and before that, the simple malloc() 3117 can be used if CONFIG_SYS_MALLOC_F is defined. 3118 3119 CONFIG_SYS_SPL_MALLOC_SIZE 3120 The size of the malloc pool used in SPL. 3121 3122 CONFIG_SPL_FRAMEWORK 3123 Enable the SPL framework under common/. This framework 3124 supports MMC, NAND and YMODEM loading of U-Boot and NAND 3125 NAND loading of the Linux Kernel. 3126 3127 CONFIG_SPL_OS_BOOT 3128 Enable booting directly to an OS from SPL. 3129 See also: doc/README.falcon 3130 3131 CONFIG_SPL_DISPLAY_PRINT 3132 For ARM, enable an optional function to print more information 3133 about the running system. 3134 3135 CONFIG_SPL_INIT_MINIMAL 3136 Arch init code should be built for a very small image 3137 3138 CONFIG_SYS_MMCSD_RAW_MODE_U_BOOT_PARTITION 3139 Partition on the MMC to load U-Boot from when the MMC is being 3140 used in raw mode 3141 3142 CONFIG_SYS_MMCSD_RAW_MODE_KERNEL_SECTOR 3143 Sector to load kernel uImage from when MMC is being 3144 used in raw mode (for Falcon mode) 3145 3146 CONFIG_SYS_MMCSD_RAW_MODE_ARGS_SECTOR, 3147 CONFIG_SYS_MMCSD_RAW_MODE_ARGS_SECTORS 3148 Sector and number of sectors to load kernel argument 3149 parameters from when MMC is being used in raw mode 3150 (for falcon mode) 3151 3152 CONFIG_SYS_MMCSD_FS_BOOT_PARTITION 3153 Partition on the MMC to load U-Boot from when the MMC is being 3154 used in fs mode 3155 3156 CONFIG_SPL_FS_LOAD_PAYLOAD_NAME 3157 Filename to read to load U-Boot when reading from filesystem 3158 3159 CONFIG_SPL_FS_LOAD_KERNEL_NAME 3160 Filename to read to load kernel uImage when reading 3161 from filesystem (for Falcon mode) 3162 3163 CONFIG_SPL_FS_LOAD_ARGS_NAME 3164 Filename to read to load kernel argument parameters 3165 when reading from filesystem (for Falcon mode) 3166 3167 CONFIG_SPL_MPC83XX_WAIT_FOR_NAND 3168 Set this for NAND SPL on PPC mpc83xx targets, so that 3169 start.S waits for the rest of the SPL to load before 3170 continuing (the hardware starts execution after just 3171 loading the first page rather than the full 4K). 3172 3173 CONFIG_SPL_SKIP_RELOCATE 3174 Avoid SPL relocation 3175 3176 CONFIG_SPL_NAND_BASE 3177 Include nand_base.c in the SPL. Requires 3178 CONFIG_SPL_NAND_DRIVERS. 3179 3180 CONFIG_SPL_NAND_DRIVERS 3181 SPL uses normal NAND drivers, not minimal drivers. 3182 3183 CONFIG_SPL_NAND_ECC 3184 Include standard software ECC in the SPL 3185 3186 CONFIG_SPL_NAND_SIMPLE 3187 Support for NAND boot using simple NAND drivers that 3188 expose the cmd_ctrl() interface. 3189 3190 CONFIG_SPL_UBI 3191 Support for a lightweight UBI (fastmap) scanner and 3192 loader 3193 3194 CONFIG_SPL_NAND_RAW_ONLY 3195 Support to boot only raw u-boot.bin images. Use this only 3196 if you need to save space. 3197 3198 CONFIG_SPL_COMMON_INIT_DDR 3199 Set for common ddr init with serial presence detect in 3200 SPL binary. 3201 3202 CONFIG_SYS_NAND_5_ADDR_CYCLE, CONFIG_SYS_NAND_PAGE_COUNT, 3203 CONFIG_SYS_NAND_PAGE_SIZE, CONFIG_SYS_NAND_OOBSIZE, 3204 CONFIG_SYS_NAND_BLOCK_SIZE, CONFIG_SYS_NAND_BAD_BLOCK_POS, 3205 CONFIG_SYS_NAND_ECCPOS, CONFIG_SYS_NAND_ECCSIZE, 3206 CONFIG_SYS_NAND_ECCBYTES 3207 Defines the size and behavior of the NAND that SPL uses 3208 to read U-Boot 3209 3210 CONFIG_SPL_NAND_BOOT 3211 Add support NAND boot 3212 3213 CONFIG_SYS_NAND_U_BOOT_OFFS 3214 Location in NAND to read U-Boot from 3215 3216 CONFIG_SYS_NAND_U_BOOT_DST 3217 Location in memory to load U-Boot to 3218 3219 CONFIG_SYS_NAND_U_BOOT_SIZE 3220 Size of image to load 3221 3222 CONFIG_SYS_NAND_U_BOOT_START 3223 Entry point in loaded image to jump to 3224 3225 CONFIG_SYS_NAND_HW_ECC_OOBFIRST 3226 Define this if you need to first read the OOB and then the 3227 data. This is used, for example, on davinci platforms. 3228 3229 CONFIG_SPL_OMAP3_ID_NAND 3230 Support for an OMAP3-specific set of functions to return the 3231 ID and MFR of the first attached NAND chip, if present. 3232 3233 CONFIG_SPL_RAM_DEVICE 3234 Support for running image already present in ram, in SPL binary 3235 3236 CONFIG_SPL_PAD_TO 3237 Image offset to which the SPL should be padded before appending 3238 the SPL payload. By default, this is defined as 3239 CONFIG_SPL_MAX_SIZE, or 0 if CONFIG_SPL_MAX_SIZE is undefined. 3240 CONFIG_SPL_PAD_TO must be either 0, meaning to append the SPL 3241 payload without any padding, or >= CONFIG_SPL_MAX_SIZE. 3242 3243 CONFIG_SPL_TARGET 3244 Final target image containing SPL and payload. Some SPLs 3245 use an arch-specific makefile fragment instead, for 3246 example if more than one image needs to be produced. 3247 3248 CONFIG_FIT_SPL_PRINT 3249 Printing information about a FIT image adds quite a bit of 3250 code to SPL. So this is normally disabled in SPL. Use this 3251 option to re-enable it. This will affect the output of the 3252 bootm command when booting a FIT image. 3253 3254- TPL framework 3255 CONFIG_TPL 3256 Enable building of TPL globally. 3257 3258 CONFIG_TPL_PAD_TO 3259 Image offset to which the TPL should be padded before appending 3260 the TPL payload. By default, this is defined as 3261 CONFIG_SPL_MAX_SIZE, or 0 if CONFIG_SPL_MAX_SIZE is undefined. 3262 CONFIG_SPL_PAD_TO must be either 0, meaning to append the SPL 3263 payload without any padding, or >= CONFIG_SPL_MAX_SIZE. 3264 3265- Interrupt support (PPC): 3266 3267 There are common interrupt_init() and timer_interrupt() 3268 for all PPC archs. interrupt_init() calls interrupt_init_cpu() 3269 for CPU specific initialization. interrupt_init_cpu() 3270 should set decrementer_count to appropriate value. If 3271 CPU resets decrementer automatically after interrupt 3272 (ppc4xx) it should set decrementer_count to zero. 3273 timer_interrupt() calls timer_interrupt_cpu() for CPU 3274 specific handling. If board has watchdog / status_led 3275 / other_activity_monitor it works automatically from 3276 general timer_interrupt(). 3277 3278 3279Board initialization settings: 3280------------------------------ 3281 3282During Initialization u-boot calls a number of board specific functions 3283to allow the preparation of board specific prerequisites, e.g. pin setup 3284before drivers are initialized. To enable these callbacks the 3285following configuration macros have to be defined. Currently this is 3286architecture specific, so please check arch/your_architecture/lib/board.c 3287typically in board_init_f() and board_init_r(). 3288 3289- CONFIG_BOARD_EARLY_INIT_F: Call board_early_init_f() 3290- CONFIG_BOARD_EARLY_INIT_R: Call board_early_init_r() 3291- CONFIG_BOARD_LATE_INIT: Call board_late_init() 3292- CONFIG_BOARD_POSTCLK_INIT: Call board_postclk_init() 3293 3294Configuration Settings: 3295----------------------- 3296 3297- CONFIG_SYS_SUPPORT_64BIT_DATA: Defined automatically if compiled as 64-bit. 3298 Optionally it can be defined to support 64-bit memory commands. 3299 3300- CONFIG_SYS_LONGHELP: Defined when you want long help messages included; 3301 undefine this when you're short of memory. 3302 3303- CONFIG_SYS_HELP_CMD_WIDTH: Defined when you want to override the default 3304 width of the commands listed in the 'help' command output. 3305 3306- CONFIG_SYS_PROMPT: This is what U-Boot prints on the console to 3307 prompt for user input. 3308 3309- CONFIG_SYS_CBSIZE: Buffer size for input from the Console 3310 3311- CONFIG_SYS_PBSIZE: Buffer size for Console output 3312 3313- CONFIG_SYS_MAXARGS: max. Number of arguments accepted for monitor commands 3314 3315- CONFIG_SYS_BARGSIZE: Buffer size for Boot Arguments which are passed to 3316 the application (usually a Linux kernel) when it is 3317 booted 3318 3319- CONFIG_SYS_BAUDRATE_TABLE: 3320 List of legal baudrate settings for this board. 3321 3322- CONFIG_SYS_MEMTEST_START, CONFIG_SYS_MEMTEST_END: 3323 Begin and End addresses of the area used by the 3324 simple memory test. 3325 3326- CONFIG_SYS_ALT_MEMTEST: 3327 Enable an alternate, more extensive memory test. 3328 3329- CONFIG_SYS_MEMTEST_SCRATCH: 3330 Scratch address used by the alternate memory test 3331 You only need to set this if address zero isn't writeable 3332 3333- CONFIG_SYS_MEM_RESERVE_SECURE 3334 Only implemented for ARMv8 for now. 3335 If defined, the size of CONFIG_SYS_MEM_RESERVE_SECURE memory 3336 is substracted from total RAM and won't be reported to OS. 3337 This memory can be used as secure memory. A variable 3338 gd->arch.secure_ram is used to track the location. In systems 3339 the RAM base is not zero, or RAM is divided into banks, 3340 this variable needs to be recalcuated to get the address. 3341 3342- CONFIG_SYS_MEM_TOP_HIDE: 3343 If CONFIG_SYS_MEM_TOP_HIDE is defined in the board config header, 3344 this specified memory area will get subtracted from the top 3345 (end) of RAM and won't get "touched" at all by U-Boot. By 3346 fixing up gd->ram_size the Linux kernel should gets passed 3347 the now "corrected" memory size and won't touch it either. 3348 This should work for arch/ppc and arch/powerpc. Only Linux 3349 board ports in arch/powerpc with bootwrapper support that 3350 recalculate the memory size from the SDRAM controller setup 3351 will have to get fixed in Linux additionally. 3352 3353 This option can be used as a workaround for the 440EPx/GRx 3354 CHIP 11 errata where the last 256 bytes in SDRAM shouldn't 3355 be touched. 3356 3357 WARNING: Please make sure that this value is a multiple of 3358 the Linux page size (normally 4k). If this is not the case, 3359 then the end address of the Linux memory will be located at a 3360 non page size aligned address and this could cause major 3361 problems. 3362 3363- CONFIG_SYS_LOADS_BAUD_CHANGE: 3364 Enable temporary baudrate change while serial download 3365 3366- CONFIG_SYS_SDRAM_BASE: 3367 Physical start address of SDRAM. _Must_ be 0 here. 3368 3369- CONFIG_SYS_FLASH_BASE: 3370 Physical start address of Flash memory. 3371 3372- CONFIG_SYS_MONITOR_BASE: 3373 Physical start address of boot monitor code (set by 3374 make config files to be same as the text base address 3375 (CONFIG_SYS_TEXT_BASE) used when linking) - same as 3376 CONFIG_SYS_FLASH_BASE when booting from flash. 3377 3378- CONFIG_SYS_MONITOR_LEN: 3379 Size of memory reserved for monitor code, used to 3380 determine _at_compile_time_ (!) if the environment is 3381 embedded within the U-Boot image, or in a separate 3382 flash sector. 3383 3384- CONFIG_SYS_MALLOC_LEN: 3385 Size of DRAM reserved for malloc() use. 3386 3387- CONFIG_SYS_MALLOC_F_LEN 3388 Size of the malloc() pool for use before relocation. If 3389 this is defined, then a very simple malloc() implementation 3390 will become available before relocation. The address is just 3391 below the global data, and the stack is moved down to make 3392 space. 3393 3394 This feature allocates regions with increasing addresses 3395 within the region. calloc() is supported, but realloc() 3396 is not available. free() is supported but does nothing. 3397 The memory will be freed (or in fact just forgotten) when 3398 U-Boot relocates itself. 3399 3400- CONFIG_SYS_MALLOC_SIMPLE 3401 Provides a simple and small malloc() and calloc() for those 3402 boards which do not use the full malloc in SPL (which is 3403 enabled with CONFIG_SYS_SPL_MALLOC_START). 3404 3405- CONFIG_SYS_NONCACHED_MEMORY: 3406 Size of non-cached memory area. This area of memory will be 3407 typically located right below the malloc() area and mapped 3408 uncached in the MMU. This is useful for drivers that would 3409 otherwise require a lot of explicit cache maintenance. For 3410 some drivers it's also impossible to properly maintain the 3411 cache. For example if the regions that need to be flushed 3412 are not a multiple of the cache-line size, *and* padding 3413 cannot be allocated between the regions to align them (i.e. 3414 if the HW requires a contiguous array of regions, and the 3415 size of each region is not cache-aligned), then a flush of 3416 one region may result in overwriting data that hardware has 3417 written to another region in the same cache-line. This can 3418 happen for example in network drivers where descriptors for 3419 buffers are typically smaller than the CPU cache-line (e.g. 3420 16 bytes vs. 32 or 64 bytes). 3421 3422 Non-cached memory is only supported on 32-bit ARM at present. 3423 3424- CONFIG_SYS_BOOTM_LEN: 3425 Normally compressed uImages are limited to an 3426 uncompressed size of 8 MBytes. If this is not enough, 3427 you can define CONFIG_SYS_BOOTM_LEN in your board config file 3428 to adjust this setting to your needs. 3429 3430- CONFIG_SYS_BOOTMAPSZ: 3431 Maximum size of memory mapped by the startup code of 3432 the Linux kernel; all data that must be processed by 3433 the Linux kernel (bd_info, boot arguments, FDT blob if 3434 used) must be put below this limit, unless "bootm_low" 3435 environment variable is defined and non-zero. In such case 3436 all data for the Linux kernel must be between "bootm_low" 3437 and "bootm_low" + CONFIG_SYS_BOOTMAPSZ. The environment 3438 variable "bootm_mapsize" will override the value of 3439 CONFIG_SYS_BOOTMAPSZ. If CONFIG_SYS_BOOTMAPSZ is undefined, 3440 then the value in "bootm_size" will be used instead. 3441 3442- CONFIG_SYS_BOOT_RAMDISK_HIGH: 3443 Enable initrd_high functionality. If defined then the 3444 initrd_high feature is enabled and the bootm ramdisk subcommand 3445 is enabled. 3446 3447- CONFIG_SYS_BOOT_GET_CMDLINE: 3448 Enables allocating and saving kernel cmdline in space between 3449 "bootm_low" and "bootm_low" + BOOTMAPSZ. 3450 3451- CONFIG_SYS_BOOT_GET_KBD: 3452 Enables allocating and saving a kernel copy of the bd_info in 3453 space between "bootm_low" and "bootm_low" + BOOTMAPSZ. 3454 3455- CONFIG_SYS_MAX_FLASH_BANKS: 3456 Max number of Flash memory banks 3457 3458- CONFIG_SYS_MAX_FLASH_SECT: 3459 Max number of sectors on a Flash chip 3460 3461- CONFIG_SYS_FLASH_ERASE_TOUT: 3462 Timeout for Flash erase operations (in ms) 3463 3464- CONFIG_SYS_FLASH_WRITE_TOUT: 3465 Timeout for Flash write operations (in ms) 3466 3467- CONFIG_SYS_FLASH_LOCK_TOUT 3468 Timeout for Flash set sector lock bit operation (in ms) 3469 3470- CONFIG_SYS_FLASH_UNLOCK_TOUT 3471 Timeout for Flash clear lock bits operation (in ms) 3472 3473- CONFIG_SYS_FLASH_PROTECTION 3474 If defined, hardware flash sectors protection is used 3475 instead of U-Boot software protection. 3476 3477- CONFIG_SYS_DIRECT_FLASH_TFTP: 3478 3479 Enable TFTP transfers directly to flash memory; 3480 without this option such a download has to be 3481 performed in two steps: (1) download to RAM, and (2) 3482 copy from RAM to flash. 3483 3484 The two-step approach is usually more reliable, since 3485 you can check if the download worked before you erase 3486 the flash, but in some situations (when system RAM is 3487 too limited to allow for a temporary copy of the 3488 downloaded image) this option may be very useful. 3489 3490- CONFIG_SYS_FLASH_CFI: 3491 Define if the flash driver uses extra elements in the 3492 common flash structure for storing flash geometry. 3493 3494- CONFIG_FLASH_CFI_DRIVER 3495 This option also enables the building of the cfi_flash driver 3496 in the drivers directory 3497 3498- CONFIG_FLASH_CFI_MTD 3499 This option enables the building of the cfi_mtd driver 3500 in the drivers directory. The driver exports CFI flash 3501 to the MTD layer. 3502 3503- CONFIG_SYS_FLASH_USE_BUFFER_WRITE 3504 Use buffered writes to flash. 3505 3506- CONFIG_FLASH_SPANSION_S29WS_N 3507 s29ws-n MirrorBit flash has non-standard addresses for buffered 3508 write commands. 3509 3510- CONFIG_SYS_FLASH_QUIET_TEST 3511 If this option is defined, the common CFI flash doesn't 3512 print it's warning upon not recognized FLASH banks. This 3513 is useful, if some of the configured banks are only 3514 optionally available. 3515 3516- CONFIG_FLASH_SHOW_PROGRESS 3517 If defined (must be an integer), print out countdown 3518 digits and dots. Recommended value: 45 (9..1) for 80 3519 column displays, 15 (3..1) for 40 column displays. 3520 3521- CONFIG_FLASH_VERIFY 3522 If defined, the content of the flash (destination) is compared 3523 against the source after the write operation. An error message 3524 will be printed when the contents are not identical. 3525 Please note that this option is useless in nearly all cases, 3526 since such flash programming errors usually are detected earlier 3527 while unprotecting/erasing/programming. Please only enable 3528 this option if you really know what you are doing. 3529 3530- CONFIG_SYS_RX_ETH_BUFFER: 3531 Defines the number of Ethernet receive buffers. On some 3532 Ethernet controllers it is recommended to set this value 3533 to 8 or even higher (EEPRO100 or 405 EMAC), since all 3534 buffers can be full shortly after enabling the interface 3535 on high Ethernet traffic. 3536 Defaults to 4 if not defined. 3537 3538- CONFIG_ENV_MAX_ENTRIES 3539 3540 Maximum number of entries in the hash table that is used 3541 internally to store the environment settings. The default 3542 setting is supposed to be generous and should work in most 3543 cases. This setting can be used to tune behaviour; see 3544 lib/hashtable.c for details. 3545 3546- CONFIG_ENV_FLAGS_LIST_DEFAULT 3547- CONFIG_ENV_FLAGS_LIST_STATIC 3548 Enable validation of the values given to environment variables when 3549 calling env set. Variables can be restricted to only decimal, 3550 hexadecimal, or boolean. If CONFIG_CMD_NET is also defined, 3551 the variables can also be restricted to IP address or MAC address. 3552 3553 The format of the list is: 3554 type_attribute = [s|d|x|b|i|m] 3555 access_attribute = [a|r|o|c] 3556 attributes = type_attribute[access_attribute] 3557 entry = variable_name[:attributes] 3558 list = entry[,list] 3559 3560 The type attributes are: 3561 s - String (default) 3562 d - Decimal 3563 x - Hexadecimal 3564 b - Boolean ([1yYtT|0nNfF]) 3565 i - IP address 3566 m - MAC address 3567 3568 The access attributes are: 3569 a - Any (default) 3570 r - Read-only 3571 o - Write-once 3572 c - Change-default 3573 3574 - CONFIG_ENV_FLAGS_LIST_DEFAULT 3575 Define this to a list (string) to define the ".flags" 3576 environment variable in the default or embedded environment. 3577 3578 - CONFIG_ENV_FLAGS_LIST_STATIC 3579 Define this to a list (string) to define validation that 3580 should be done if an entry is not found in the ".flags" 3581 environment variable. To override a setting in the static 3582 list, simply add an entry for the same variable name to the 3583 ".flags" variable. 3584 3585 If CONFIG_REGEX is defined, the variable_name above is evaluated as a 3586 regular expression. This allows multiple variables to define the same 3587 flags without explicitly listing them for each variable. 3588 3589- CONFIG_ENV_ACCESS_IGNORE_FORCE 3590 If defined, don't allow the -f switch to env set override variable 3591 access flags. 3592 3593- CONFIG_USE_STDINT 3594 If stdint.h is available with your toolchain you can define this 3595 option to enable it. You can provide option 'USE_STDINT=1' when 3596 building U-Boot to enable this. 3597 3598The following definitions that deal with the placement and management 3599of environment data (variable area); in general, we support the 3600following configurations: 3601 3602- CONFIG_BUILD_ENVCRC: 3603 3604 Builds up envcrc with the target environment so that external utils 3605 may easily extract it and embed it in final U-Boot images. 3606 3607- CONFIG_ENV_IS_IN_FLASH: 3608 3609 Define this if the environment is in flash memory. 3610 3611 a) The environment occupies one whole flash sector, which is 3612 "embedded" in the text segment with the U-Boot code. This 3613 happens usually with "bottom boot sector" or "top boot 3614 sector" type flash chips, which have several smaller 3615 sectors at the start or the end. For instance, such a 3616 layout can have sector sizes of 8, 2x4, 16, Nx32 kB. In 3617 such a case you would place the environment in one of the 3618 4 kB sectors - with U-Boot code before and after it. With 3619 "top boot sector" type flash chips, you would put the 3620 environment in one of the last sectors, leaving a gap 3621 between U-Boot and the environment. 3622 3623 - CONFIG_ENV_OFFSET: 3624 3625 Offset of environment data (variable area) to the 3626 beginning of flash memory; for instance, with bottom boot 3627 type flash chips the second sector can be used: the offset 3628 for this sector is given here. 3629 3630 CONFIG_ENV_OFFSET is used relative to CONFIG_SYS_FLASH_BASE. 3631 3632 - CONFIG_ENV_ADDR: 3633 3634 This is just another way to specify the start address of 3635 the flash sector containing the environment (instead of 3636 CONFIG_ENV_OFFSET). 3637 3638 - CONFIG_ENV_SECT_SIZE: 3639 3640 Size of the sector containing the environment. 3641 3642 3643 b) Sometimes flash chips have few, equal sized, BIG sectors. 3644 In such a case you don't want to spend a whole sector for 3645 the environment. 3646 3647 - CONFIG_ENV_SIZE: 3648 3649 If you use this in combination with CONFIG_ENV_IS_IN_FLASH 3650 and CONFIG_ENV_SECT_SIZE, you can specify to use only a part 3651 of this flash sector for the environment. This saves 3652 memory for the RAM copy of the environment. 3653 3654 It may also save flash memory if you decide to use this 3655 when your environment is "embedded" within U-Boot code, 3656 since then the remainder of the flash sector could be used 3657 for U-Boot code. It should be pointed out that this is 3658 STRONGLY DISCOURAGED from a robustness point of view: 3659 updating the environment in flash makes it always 3660 necessary to erase the WHOLE sector. If something goes 3661 wrong before the contents has been restored from a copy in 3662 RAM, your target system will be dead. 3663 3664 - CONFIG_ENV_ADDR_REDUND 3665 CONFIG_ENV_SIZE_REDUND 3666 3667 These settings describe a second storage area used to hold 3668 a redundant copy of the environment data, so that there is 3669 a valid backup copy in case there is a power failure during 3670 a "saveenv" operation. 3671 3672BE CAREFUL! Any changes to the flash layout, and some changes to the 3673source code will make it necessary to adapt <board>/u-boot.lds* 3674accordingly! 3675 3676 3677- CONFIG_ENV_IS_IN_NVRAM: 3678 3679 Define this if you have some non-volatile memory device 3680 (NVRAM, battery buffered SRAM) which you want to use for the 3681 environment. 3682 3683 - CONFIG_ENV_ADDR: 3684 - CONFIG_ENV_SIZE: 3685 3686 These two #defines are used to determine the memory area you 3687 want to use for environment. It is assumed that this memory 3688 can just be read and written to, without any special 3689 provision. 3690 3691BE CAREFUL! The first access to the environment happens quite early 3692in U-Boot initialization (when we try to get the setting of for the 3693console baudrate). You *MUST* have mapped your NVRAM area then, or 3694U-Boot will hang. 3695 3696Please note that even with NVRAM we still use a copy of the 3697environment in RAM: we could work on NVRAM directly, but we want to 3698keep settings there always unmodified except somebody uses "saveenv" 3699to save the current settings. 3700 3701 3702- CONFIG_ENV_IS_IN_EEPROM: 3703 3704 Use this if you have an EEPROM or similar serial access 3705 device and a driver for it. 3706 3707 - CONFIG_ENV_OFFSET: 3708 - CONFIG_ENV_SIZE: 3709 3710 These two #defines specify the offset and size of the 3711 environment area within the total memory of your EEPROM. 3712 3713 - CONFIG_SYS_I2C_EEPROM_ADDR: 3714 If defined, specified the chip address of the EEPROM device. 3715 The default address is zero. 3716 3717 - CONFIG_SYS_I2C_EEPROM_BUS: 3718 If defined, specified the i2c bus of the EEPROM device. 3719 3720 - CONFIG_SYS_EEPROM_PAGE_WRITE_BITS: 3721 If defined, the number of bits used to address bytes in a 3722 single page in the EEPROM device. A 64 byte page, for example 3723 would require six bits. 3724 3725 - CONFIG_SYS_EEPROM_PAGE_WRITE_DELAY_MS: 3726 If defined, the number of milliseconds to delay between 3727 page writes. The default is zero milliseconds. 3728 3729 - CONFIG_SYS_I2C_EEPROM_ADDR_LEN: 3730 The length in bytes of the EEPROM memory array address. Note 3731 that this is NOT the chip address length! 3732 3733 - CONFIG_SYS_I2C_EEPROM_ADDR_OVERFLOW: 3734 EEPROM chips that implement "address overflow" are ones 3735 like Catalyst 24WC04/08/16 which has 9/10/11 bits of 3736 address and the extra bits end up in the "chip address" bit 3737 slots. This makes a 24WC08 (1Kbyte) chip look like four 256 3738 byte chips. 3739 3740 Note that we consider the length of the address field to 3741 still be one byte because the extra address bits are hidden 3742 in the chip address. 3743 3744 - CONFIG_SYS_EEPROM_SIZE: 3745 The size in bytes of the EEPROM device. 3746 3747 - CONFIG_ENV_EEPROM_IS_ON_I2C 3748 define this, if you have I2C and SPI activated, and your 3749 EEPROM, which holds the environment, is on the I2C bus. 3750 3751 - CONFIG_I2C_ENV_EEPROM_BUS 3752 if you have an Environment on an EEPROM reached over 3753 I2C muxes, you can define here, how to reach this 3754 EEPROM. For example: 3755 3756 #define CONFIG_I2C_ENV_EEPROM_BUS 1 3757 3758 EEPROM which holds the environment, is reached over 3759 a pca9547 i2c mux with address 0x70, channel 3. 3760 3761- CONFIG_ENV_IS_IN_DATAFLASH: 3762 3763 Define this if you have a DataFlash memory device which you 3764 want to use for the environment. 3765 3766 - CONFIG_ENV_OFFSET: 3767 - CONFIG_ENV_ADDR: 3768 - CONFIG_ENV_SIZE: 3769 3770 These three #defines specify the offset and size of the 3771 environment area within the total memory of your DataFlash placed 3772 at the specified address. 3773 3774- CONFIG_ENV_IS_IN_SPI_FLASH: 3775 3776 Define this if you have a SPI Flash memory device which you 3777 want to use for the environment. 3778 3779 - CONFIG_ENV_OFFSET: 3780 - CONFIG_ENV_SIZE: 3781 3782 These two #defines specify the offset and size of the 3783 environment area within the SPI Flash. CONFIG_ENV_OFFSET must be 3784 aligned to an erase sector boundary. 3785 3786 - CONFIG_ENV_SECT_SIZE: 3787 3788 Define the SPI flash's sector size. 3789 3790 - CONFIG_ENV_OFFSET_REDUND (optional): 3791 3792 This setting describes a second storage area of CONFIG_ENV_SIZE 3793 size used to hold a redundant copy of the environment data, so 3794 that there is a valid backup copy in case there is a power failure 3795 during a "saveenv" operation. CONFIG_ENV_OFFSET_REDUND must be 3796 aligned to an erase sector boundary. 3797 3798 - CONFIG_ENV_SPI_BUS (optional): 3799 - CONFIG_ENV_SPI_CS (optional): 3800 3801 Define the SPI bus and chip select. If not defined they will be 0. 3802 3803 - CONFIG_ENV_SPI_MAX_HZ (optional): 3804 3805 Define the SPI max work clock. If not defined then use 1MHz. 3806 3807 - CONFIG_ENV_SPI_MODE (optional): 3808 3809 Define the SPI work mode. If not defined then use SPI_MODE_3. 3810 3811- CONFIG_ENV_IS_IN_REMOTE: 3812 3813 Define this if you have a remote memory space which you 3814 want to use for the local device's environment. 3815 3816 - CONFIG_ENV_ADDR: 3817 - CONFIG_ENV_SIZE: 3818 3819 These two #defines specify the address and size of the 3820 environment area within the remote memory space. The 3821 local device can get the environment from remote memory 3822 space by SRIO or PCIE links. 3823 3824BE CAREFUL! For some special cases, the local device can not use 3825"saveenv" command. For example, the local device will get the 3826environment stored in a remote NOR flash by SRIO or PCIE link, 3827but it can not erase, write this NOR flash by SRIO or PCIE interface. 3828 3829- CONFIG_ENV_IS_IN_NAND: 3830 3831 Define this if you have a NAND device which you want to use 3832 for the environment. 3833 3834 - CONFIG_ENV_OFFSET: 3835 - CONFIG_ENV_SIZE: 3836 3837 These two #defines specify the offset and size of the environment 3838 area within the first NAND device. CONFIG_ENV_OFFSET must be 3839 aligned to an erase block boundary. 3840 3841 - CONFIG_ENV_OFFSET_REDUND (optional): 3842 3843 This setting describes a second storage area of CONFIG_ENV_SIZE 3844 size used to hold a redundant copy of the environment data, so 3845 that there is a valid backup copy in case there is a power failure 3846 during a "saveenv" operation. CONFIG_ENV_OFFSET_REDUND must be 3847 aligned to an erase block boundary. 3848 3849 - CONFIG_ENV_RANGE (optional): 3850 3851 Specifies the length of the region in which the environment 3852 can be written. This should be a multiple of the NAND device's 3853 block size. Specifying a range with more erase blocks than 3854 are needed to hold CONFIG_ENV_SIZE allows bad blocks within 3855 the range to be avoided. 3856 3857 - CONFIG_ENV_OFFSET_OOB (optional): 3858 3859 Enables support for dynamically retrieving the offset of the 3860 environment from block zero's out-of-band data. The 3861 "nand env.oob" command can be used to record this offset. 3862 Currently, CONFIG_ENV_OFFSET_REDUND is not supported when 3863 using CONFIG_ENV_OFFSET_OOB. 3864 3865- CONFIG_NAND_ENV_DST 3866 3867 Defines address in RAM to which the nand_spl code should copy the 3868 environment. If redundant environment is used, it will be copied to 3869 CONFIG_NAND_ENV_DST + CONFIG_ENV_SIZE. 3870 3871- CONFIG_ENV_IS_IN_UBI: 3872 3873 Define this if you have an UBI volume that you want to use for the 3874 environment. This has the benefit of wear-leveling the environment 3875 accesses, which is important on NAND. 3876 3877 - CONFIG_ENV_UBI_PART: 3878 3879 Define this to a string that is the mtd partition containing the UBI. 3880 3881 - CONFIG_ENV_UBI_VOLUME: 3882 3883 Define this to the name of the volume that you want to store the 3884 environment in. 3885 3886 - CONFIG_ENV_UBI_VOLUME_REDUND: 3887 3888 Define this to the name of another volume to store a second copy of 3889 the environment in. This will enable redundant environments in UBI. 3890 It is assumed that both volumes are in the same MTD partition. 3891 3892 - CONFIG_UBI_SILENCE_MSG 3893 - CONFIG_UBIFS_SILENCE_MSG 3894 3895 You will probably want to define these to avoid a really noisy system 3896 when storing the env in UBI. 3897 3898- CONFIG_ENV_IS_IN_FAT: 3899 Define this if you want to use the FAT file system for the environment. 3900 3901 - FAT_ENV_INTERFACE: 3902 3903 Define this to a string that is the name of the block device. 3904 3905 - FAT_ENV_DEVICE_AND_PART: 3906 3907 Define this to a string to specify the partition of the device. It can 3908 be as following: 3909 3910 "D:P", "D:0", "D", "D:" or "D:auto" (D, P are integers. And P >= 1) 3911 - "D:P": device D partition P. Error occurs if device D has no 3912 partition table. 3913 - "D:0": device D. 3914 - "D" or "D:": device D partition 1 if device D has partition 3915 table, or the whole device D if has no partition 3916 table. 3917 - "D:auto": first partition in device D with bootable flag set. 3918 If none, first valid partition in device D. If no 3919 partition table then means device D. 3920 3921 - FAT_ENV_FILE: 3922 3923 It's a string of the FAT file name. This file use to store the 3924 environment. 3925 3926 - CONFIG_FAT_WRITE: 3927 This should be defined. Otherwise it cannot save the environment file. 3928 3929- CONFIG_ENV_IS_IN_MMC: 3930 3931 Define this if you have an MMC device which you want to use for the 3932 environment. 3933 3934 - CONFIG_SYS_MMC_ENV_DEV: 3935 3936 Specifies which MMC device the environment is stored in. 3937 3938 - CONFIG_SYS_MMC_ENV_PART (optional): 3939 3940 Specifies which MMC partition the environment is stored in. If not 3941 set, defaults to partition 0, the user area. Common values might be 3942 1 (first MMC boot partition), 2 (second MMC boot partition). 3943 3944 - CONFIG_ENV_OFFSET: 3945 - CONFIG_ENV_SIZE: 3946 3947 These two #defines specify the offset and size of the environment 3948 area within the specified MMC device. 3949 3950 If offset is positive (the usual case), it is treated as relative to 3951 the start of the MMC partition. If offset is negative, it is treated 3952 as relative to the end of the MMC partition. This can be useful if 3953 your board may be fitted with different MMC devices, which have 3954 different sizes for the MMC partitions, and you always want the 3955 environment placed at the very end of the partition, to leave the 3956 maximum possible space before it, to store other data. 3957 3958 These two values are in units of bytes, but must be aligned to an 3959 MMC sector boundary. 3960 3961 - CONFIG_ENV_OFFSET_REDUND (optional): 3962 3963 Specifies a second storage area, of CONFIG_ENV_SIZE size, used to 3964 hold a redundant copy of the environment data. This provides a 3965 valid backup copy in case the other copy is corrupted, e.g. due 3966 to a power failure during a "saveenv" operation. 3967 3968 This value may also be positive or negative; this is handled in the 3969 same way as CONFIG_ENV_OFFSET. 3970 3971 This value is also in units of bytes, but must also be aligned to 3972 an MMC sector boundary. 3973 3974 - CONFIG_ENV_SIZE_REDUND (optional): 3975 3976 This value need not be set, even when CONFIG_ENV_OFFSET_REDUND is 3977 set. If this value is set, it must be set to the same value as 3978 CONFIG_ENV_SIZE. 3979 3980- CONFIG_SYS_SPI_INIT_OFFSET 3981 3982 Defines offset to the initial SPI buffer area in DPRAM. The 3983 area is used at an early stage (ROM part) if the environment 3984 is configured to reside in the SPI EEPROM: We need a 520 byte 3985 scratch DPRAM area. It is used between the two initialization 3986 calls (spi_init_f() and spi_init_r()). A value of 0xB00 seems 3987 to be a good choice since it makes it far enough from the 3988 start of the data area as well as from the stack pointer. 3989 3990Please note that the environment is read-only until the monitor 3991has been relocated to RAM and a RAM copy of the environment has been 3992created; also, when using EEPROM you will have to use getenv_f() 3993until then to read environment variables. 3994 3995The environment is protected by a CRC32 checksum. Before the monitor 3996is relocated into RAM, as a result of a bad CRC you will be working 3997with the compiled-in default environment - *silently*!!! [This is 3998necessary, because the first environment variable we need is the 3999"baudrate" setting for the console - if we have a bad CRC, we don't 4000have any device yet where we could complain.] 4001 4002Note: once the monitor has been relocated, then it will complain if 4003the default environment is used; a new CRC is computed as soon as you 4004use the "saveenv" command to store a valid environment. 4005 4006- CONFIG_SYS_FAULT_ECHO_LINK_DOWN: 4007 Echo the inverted Ethernet link state to the fault LED. 4008 4009 Note: If this option is active, then CONFIG_SYS_FAULT_MII_ADDR 4010 also needs to be defined. 4011 4012- CONFIG_SYS_FAULT_MII_ADDR: 4013 MII address of the PHY to check for the Ethernet link state. 4014 4015- CONFIG_NS16550_MIN_FUNCTIONS: 4016 Define this if you desire to only have use of the NS16550_init 4017 and NS16550_putc functions for the serial driver located at 4018 drivers/serial/ns16550.c. This option is useful for saving 4019 space for already greatly restricted images, including but not 4020 limited to NAND_SPL configurations. 4021 4022- CONFIG_DISPLAY_BOARDINFO 4023 Display information about the board that U-Boot is running on 4024 when U-Boot starts up. The board function checkboard() is called 4025 to do this. 4026 4027- CONFIG_DISPLAY_BOARDINFO_LATE 4028 Similar to the previous option, but display this information 4029 later, once stdio is running and output goes to the LCD, if 4030 present. 4031 4032- CONFIG_BOARD_SIZE_LIMIT: 4033 Maximum size of the U-Boot image. When defined, the 4034 build system checks that the actual size does not 4035 exceed it. 4036 4037Low Level (hardware related) configuration options: 4038--------------------------------------------------- 4039 4040- CONFIG_SYS_CACHELINE_SIZE: 4041 Cache Line Size of the CPU. 4042 4043- CONFIG_SYS_DEFAULT_IMMR: 4044 Default address of the IMMR after system reset. 4045 4046 Needed on some 8260 systems (MPC8260ADS, PQ2FADS-ZU, 4047 and RPXsuper) to be able to adjust the position of 4048 the IMMR register after a reset. 4049 4050- CONFIG_SYS_CCSRBAR_DEFAULT: 4051 Default (power-on reset) physical address of CCSR on Freescale 4052 PowerPC SOCs. 4053 4054- CONFIG_SYS_CCSRBAR: 4055 Virtual address of CCSR. On a 32-bit build, this is typically 4056 the same value as CONFIG_SYS_CCSRBAR_DEFAULT. 4057 4058 CONFIG_SYS_DEFAULT_IMMR must also be set to this value, 4059 for cross-platform code that uses that macro instead. 4060 4061- CONFIG_SYS_CCSRBAR_PHYS: 4062 Physical address of CCSR. CCSR can be relocated to a new 4063 physical address, if desired. In this case, this macro should 4064 be set to that address. Otherwise, it should be set to the 4065 same value as CONFIG_SYS_CCSRBAR_DEFAULT. For example, CCSR 4066 is typically relocated on 36-bit builds. It is recommended 4067 that this macro be defined via the _HIGH and _LOW macros: 4068 4069 #define CONFIG_SYS_CCSRBAR_PHYS ((CONFIG_SYS_CCSRBAR_PHYS_HIGH 4070 * 1ull) << 32 | CONFIG_SYS_CCSRBAR_PHYS_LOW) 4071 4072- CONFIG_SYS_CCSRBAR_PHYS_HIGH: 4073 Bits 33-36 of CONFIG_SYS_CCSRBAR_PHYS. This value is typically 4074 either 0 (32-bit build) or 0xF (36-bit build). This macro is 4075 used in assembly code, so it must not contain typecasts or 4076 integer size suffixes (e.g. "ULL"). 4077 4078- CONFIG_SYS_CCSRBAR_PHYS_LOW: 4079 Lower 32-bits of CONFIG_SYS_CCSRBAR_PHYS. This macro is 4080 used in assembly code, so it must not contain typecasts or 4081 integer size suffixes (e.g. "ULL"). 4082 4083- CONFIG_SYS_CCSR_DO_NOT_RELOCATE: 4084 If this macro is defined, then CONFIG_SYS_CCSRBAR_PHYS will be 4085 forced to a value that ensures that CCSR is not relocated. 4086 4087- Floppy Disk Support: 4088 CONFIG_SYS_FDC_DRIVE_NUMBER 4089 4090 the default drive number (default value 0) 4091 4092 CONFIG_SYS_ISA_IO_STRIDE 4093 4094 defines the spacing between FDC chipset registers 4095 (default value 1) 4096 4097 CONFIG_SYS_ISA_IO_OFFSET 4098 4099 defines the offset of register from address. It 4100 depends on which part of the data bus is connected to 4101 the FDC chipset. (default value 0) 4102 4103 If CONFIG_SYS_ISA_IO_STRIDE CONFIG_SYS_ISA_IO_OFFSET and 4104 CONFIG_SYS_FDC_DRIVE_NUMBER are undefined, they take their 4105 default value. 4106 4107 if CONFIG_SYS_FDC_HW_INIT is defined, then the function 4108 fdc_hw_init() is called at the beginning of the FDC 4109 setup. fdc_hw_init() must be provided by the board 4110 source code. It is used to make hardware-dependent 4111 initializations. 4112 4113- CONFIG_IDE_AHB: 4114 Most IDE controllers were designed to be connected with PCI 4115 interface. Only few of them were designed for AHB interface. 4116 When software is doing ATA command and data transfer to 4117 IDE devices through IDE-AHB controller, some additional 4118 registers accessing to these kind of IDE-AHB controller 4119 is required. 4120 4121- CONFIG_SYS_IMMR: Physical address of the Internal Memory. 4122 DO NOT CHANGE unless you know exactly what you're 4123 doing! (11-4) [MPC8xx/82xx systems only] 4124 4125- CONFIG_SYS_INIT_RAM_ADDR: 4126 4127 Start address of memory area that can be used for 4128 initial data and stack; please note that this must be 4129 writable memory that is working WITHOUT special 4130 initialization, i. e. you CANNOT use normal RAM which 4131 will become available only after programming the 4132 memory controller and running certain initialization 4133 sequences. 4134 4135 U-Boot uses the following memory types: 4136 - MPC8xx and MPC8260: IMMR (internal memory of the CPU) 4137 - MPC824X: data cache 4138 - PPC4xx: data cache 4139 4140- CONFIG_SYS_GBL_DATA_OFFSET: 4141 4142 Offset of the initial data structure in the memory 4143 area defined by CONFIG_SYS_INIT_RAM_ADDR. Usually 4144 CONFIG_SYS_GBL_DATA_OFFSET is chosen such that the initial 4145 data is located at the end of the available space 4146 (sometimes written as (CONFIG_SYS_INIT_RAM_SIZE - 4147 GENERATED_GBL_DATA_SIZE), and the initial stack is just 4148 below that area (growing from (CONFIG_SYS_INIT_RAM_ADDR + 4149 CONFIG_SYS_GBL_DATA_OFFSET) downward. 4150 4151 Note: 4152 On the MPC824X (or other systems that use the data 4153 cache for initial memory) the address chosen for 4154 CONFIG_SYS_INIT_RAM_ADDR is basically arbitrary - it must 4155 point to an otherwise UNUSED address space between 4156 the top of RAM and the start of the PCI space. 4157 4158- CONFIG_SYS_SIUMCR: SIU Module Configuration (11-6) 4159 4160- CONFIG_SYS_SYPCR: System Protection Control (11-9) 4161 4162- CONFIG_SYS_TBSCR: Time Base Status and Control (11-26) 4163 4164- CONFIG_SYS_PISCR: Periodic Interrupt Status and Control (11-31) 4165 4166- CONFIG_SYS_PLPRCR: PLL, Low-Power, and Reset Control Register (15-30) 4167 4168- CONFIG_SYS_SCCR: System Clock and reset Control Register (15-27) 4169 4170- CONFIG_SYS_OR_TIMING_SDRAM: 4171 SDRAM timing 4172 4173- CONFIG_SYS_MAMR_PTA: 4174 periodic timer for refresh 4175 4176- CONFIG_SYS_DER: Debug Event Register (37-47) 4177 4178- FLASH_BASE0_PRELIM, FLASH_BASE1_PRELIM, CONFIG_SYS_REMAP_OR_AM, 4179 CONFIG_SYS_PRELIM_OR_AM, CONFIG_SYS_OR_TIMING_FLASH, CONFIG_SYS_OR0_REMAP, 4180 CONFIG_SYS_OR0_PRELIM, CONFIG_SYS_BR0_PRELIM, CONFIG_SYS_OR1_REMAP, CONFIG_SYS_OR1_PRELIM, 4181 CONFIG_SYS_BR1_PRELIM: 4182 Memory Controller Definitions: BR0/1 and OR0/1 (FLASH) 4183 4184- SDRAM_BASE2_PRELIM, SDRAM_BASE3_PRELIM, SDRAM_MAX_SIZE, 4185 CONFIG_SYS_OR_TIMING_SDRAM, CONFIG_SYS_OR2_PRELIM, CONFIG_SYS_BR2_PRELIM, 4186 CONFIG_SYS_OR3_PRELIM, CONFIG_SYS_BR3_PRELIM: 4187 Memory Controller Definitions: BR2/3 and OR2/3 (SDRAM) 4188 4189- CONFIG_SYS_MAMR_PTA, CONFIG_SYS_MPTPR_2BK_4K, CONFIG_SYS_MPTPR_1BK_4K, CONFIG_SYS_MPTPR_2BK_8K, 4190 CONFIG_SYS_MPTPR_1BK_8K, CONFIG_SYS_MAMR_8COL, CONFIG_SYS_MAMR_9COL: 4191 Machine Mode Register and Memory Periodic Timer 4192 Prescaler definitions (SDRAM timing) 4193 4194- CONFIG_SYS_I2C_UCODE_PATCH, CONFIG_SYS_I2C_DPMEM_OFFSET [0x1FC0]: 4195 enable I2C microcode relocation patch (MPC8xx); 4196 define relocation offset in DPRAM [DSP2] 4197 4198- CONFIG_SYS_SMC_UCODE_PATCH, CONFIG_SYS_SMC_DPMEM_OFFSET [0x1FC0]: 4199 enable SMC microcode relocation patch (MPC8xx); 4200 define relocation offset in DPRAM [SMC1] 4201 4202- CONFIG_SYS_SPI_UCODE_PATCH, CONFIG_SYS_SPI_DPMEM_OFFSET [0x1FC0]: 4203 enable SPI microcode relocation patch (MPC8xx); 4204 define relocation offset in DPRAM [SCC4] 4205 4206- CONFIG_SYS_CPM_POST_WORD_ADDR: (MPC8xx, MPC8260 only) 4207 Offset of the bootmode word in DPRAM used by post 4208 (Power On Self Tests). This definition overrides 4209 #define'd default value in commproc.h resp. 4210 cpm_8260.h. 4211 4212- CONFIG_SYS_PCI_SLV_MEM_LOCAL, CONFIG_SYS_PCI_SLV_MEM_BUS, CONFIG_SYS_PICMR0_MASK_ATTRIB, 4213 CONFIG_SYS_PCI_MSTR0_LOCAL, CONFIG_SYS_PCIMSK0_MASK, CONFIG_SYS_PCI_MSTR1_LOCAL, 4214 CONFIG_SYS_PCIMSK1_MASK, CONFIG_SYS_PCI_MSTR_MEM_LOCAL, CONFIG_SYS_PCI_MSTR_MEM_BUS, 4215 CONFIG_SYS_CPU_PCI_MEM_START, CONFIG_SYS_PCI_MSTR_MEM_SIZE, CONFIG_SYS_POCMR0_MASK_ATTRIB, 4216 CONFIG_SYS_PCI_MSTR_MEMIO_LOCAL, CONFIG_SYS_PCI_MSTR_MEMIO_BUS, CPU_PCI_MEMIO_START, 4217 CONFIG_SYS_PCI_MSTR_MEMIO_SIZE, CONFIG_SYS_POCMR1_MASK_ATTRIB, CONFIG_SYS_PCI_MSTR_IO_LOCAL, 4218 CONFIG_SYS_PCI_MSTR_IO_BUS, CONFIG_SYS_CPU_PCI_IO_START, CONFIG_SYS_PCI_MSTR_IO_SIZE, 4219 CONFIG_SYS_POCMR2_MASK_ATTRIB: (MPC826x only) 4220 Overrides the default PCI memory map in arch/powerpc/cpu/mpc8260/pci.c if set. 4221 4222- CONFIG_PCI_DISABLE_PCIE: 4223 Disable PCI-Express on systems where it is supported but not 4224 required. 4225 4226- CONFIG_PCI_ENUM_ONLY 4227 Only scan through and get the devices on the buses. 4228 Don't do any setup work, presumably because someone or 4229 something has already done it, and we don't need to do it 4230 a second time. Useful for platforms that are pre-booted 4231 by coreboot or similar. 4232 4233- CONFIG_PCI_INDIRECT_BRIDGE: 4234 Enable support for indirect PCI bridges. 4235 4236- CONFIG_SYS_SRIO: 4237 Chip has SRIO or not 4238 4239- CONFIG_SRIO1: 4240 Board has SRIO 1 port available 4241 4242- CONFIG_SRIO2: 4243 Board has SRIO 2 port available 4244 4245- CONFIG_SRIO_PCIE_BOOT_MASTER 4246 Board can support master function for Boot from SRIO and PCIE 4247 4248- CONFIG_SYS_SRIOn_MEM_VIRT: 4249 Virtual Address of SRIO port 'n' memory region 4250 4251- CONFIG_SYS_SRIOn_MEM_PHYS: 4252 Physical Address of SRIO port 'n' memory region 4253 4254- CONFIG_SYS_SRIOn_MEM_SIZE: 4255 Size of SRIO port 'n' memory region 4256 4257- CONFIG_SYS_NAND_BUSWIDTH_16BIT 4258 Defined to tell the NAND controller that the NAND chip is using 4259 a 16 bit bus. 4260 Not all NAND drivers use this symbol. 4261 Example of drivers that use it: 4262 - drivers/mtd/nand/ndfc.c 4263 - drivers/mtd/nand/mxc_nand.c 4264 4265- CONFIG_SYS_NDFC_EBC0_CFG 4266 Sets the EBC0_CFG register for the NDFC. If not defined 4267 a default value will be used. 4268 4269- CONFIG_SPD_EEPROM 4270 Get DDR timing information from an I2C EEPROM. Common 4271 with pluggable memory modules such as SODIMMs 4272 4273 SPD_EEPROM_ADDRESS 4274 I2C address of the SPD EEPROM 4275 4276- CONFIG_SYS_SPD_BUS_NUM 4277 If SPD EEPROM is on an I2C bus other than the first 4278 one, specify here. Note that the value must resolve 4279 to something your driver can deal with. 4280 4281- CONFIG_SYS_DDR_RAW_TIMING 4282 Get DDR timing information from other than SPD. Common with 4283 soldered DDR chips onboard without SPD. DDR raw timing 4284 parameters are extracted from datasheet and hard-coded into 4285 header files or board specific files. 4286 4287- CONFIG_FSL_DDR_INTERACTIVE 4288 Enable interactive DDR debugging. See doc/README.fsl-ddr. 4289 4290- CONFIG_FSL_DDR_SYNC_REFRESH 4291 Enable sync of refresh for multiple controllers. 4292 4293- CONFIG_FSL_DDR_BIST 4294 Enable built-in memory test for Freescale DDR controllers. 4295 4296- CONFIG_SYS_83XX_DDR_USES_CS0 4297 Only for 83xx systems. If specified, then DDR should 4298 be configured using CS0 and CS1 instead of CS2 and CS3. 4299 4300- CONFIG_ETHER_ON_FEC[12] 4301 Define to enable FEC[12] on a 8xx series processor. 4302 4303- CONFIG_FEC[12]_PHY 4304 Define to the hardcoded PHY address which corresponds 4305 to the given FEC; i. e. 4306 #define CONFIG_FEC1_PHY 4 4307 means that the PHY with address 4 is connected to FEC1 4308 4309 When set to -1, means to probe for first available. 4310 4311- CONFIG_FEC[12]_PHY_NORXERR 4312 The PHY does not have a RXERR line (RMII only). 4313 (so program the FEC to ignore it). 4314 4315- CONFIG_RMII 4316 Enable RMII mode for all FECs. 4317 Note that this is a global option, we can't 4318 have one FEC in standard MII mode and another in RMII mode. 4319 4320- CONFIG_CRC32_VERIFY 4321 Add a verify option to the crc32 command. 4322 The syntax is: 4323 4324 => crc32 -v <address> <count> <crc32> 4325 4326 Where address/count indicate a memory area 4327 and crc32 is the correct crc32 which the 4328 area should have. 4329 4330- CONFIG_LOOPW 4331 Add the "loopw" memory command. This only takes effect if 4332 the memory commands are activated globally (CONFIG_CMD_MEM). 4333 4334- CONFIG_MX_CYCLIC 4335 Add the "mdc" and "mwc" memory commands. These are cyclic 4336 "md/mw" commands. 4337 Examples: 4338 4339 => mdc.b 10 4 500 4340 This command will print 4 bytes (10,11,12,13) each 500 ms. 4341 4342 => mwc.l 100 12345678 10 4343 This command will write 12345678 to address 100 all 10 ms. 4344 4345 This only takes effect if the memory commands are activated 4346 globally (CONFIG_CMD_MEM). 4347 4348- CONFIG_SKIP_LOWLEVEL_INIT 4349 [ARM, NDS32, MIPS only] If this variable is defined, then certain 4350 low level initializations (like setting up the memory 4351 controller) are omitted and/or U-Boot does not 4352 relocate itself into RAM. 4353 4354 Normally this variable MUST NOT be defined. The only 4355 exception is when U-Boot is loaded (to RAM) by some 4356 other boot loader or by a debugger which performs 4357 these initializations itself. 4358 4359- CONFIG_SKIP_LOWLEVEL_INIT_ONLY 4360 [ARM926EJ-S only] This allows just the call to lowlevel_init() 4361 to be skipped. The normal CP15 init (such as enabling the 4362 instruction cache) is still performed. 4363 4364- CONFIG_SPL_BUILD 4365 Modifies the behaviour of start.S when compiling a loader 4366 that is executed before the actual U-Boot. E.g. when 4367 compiling a NAND SPL. 4368 4369- CONFIG_TPL_BUILD 4370 Modifies the behaviour of start.S when compiling a loader 4371 that is executed after the SPL and before the actual U-Boot. 4372 It is loaded by the SPL. 4373 4374- CONFIG_SYS_MPC85XX_NO_RESETVEC 4375 Only for 85xx systems. If this variable is specified, the section 4376 .resetvec is not kept and the section .bootpg is placed in the 4377 previous 4k of the .text section. 4378 4379- CONFIG_ARCH_MAP_SYSMEM 4380 Generally U-Boot (and in particular the md command) uses 4381 effective address. It is therefore not necessary to regard 4382 U-Boot address as virtual addresses that need to be translated 4383 to physical addresses. However, sandbox requires this, since 4384 it maintains its own little RAM buffer which contains all 4385 addressable memory. This option causes some memory accesses 4386 to be mapped through map_sysmem() / unmap_sysmem(). 4387 4388- CONFIG_X86_RESET_VECTOR 4389 If defined, the x86 reset vector code is included. This is not 4390 needed when U-Boot is running from Coreboot. 4391 4392- CONFIG_SPL_AM33XX_ENABLE_RTC32K_OSC: 4393 Enables the RTC32K OSC on AM33xx based plattforms 4394 4395- CONFIG_SYS_NAND_NO_SUBPAGE_WRITE 4396 Option to disable subpage write in NAND driver 4397 driver that uses this: 4398 drivers/mtd/nand/davinci_nand.c 4399 4400Freescale QE/FMAN Firmware Support: 4401----------------------------------- 4402 4403The Freescale QUICCEngine (QE) and Frame Manager (FMAN) both support the 4404loading of "firmware", which is encoded in the QE firmware binary format. 4405This firmware often needs to be loaded during U-Boot booting, so macros 4406are used to identify the storage device (NOR flash, SPI, etc) and the address 4407within that device. 4408 4409- CONFIG_SYS_FMAN_FW_ADDR 4410 The address in the storage device where the FMAN microcode is located. The 4411 meaning of this address depends on which CONFIG_SYS_QE_FW_IN_xxx macro 4412 is also specified. 4413 4414- CONFIG_SYS_QE_FW_ADDR 4415 The address in the storage device where the QE microcode is located. The 4416 meaning of this address depends on which CONFIG_SYS_QE_FW_IN_xxx macro 4417 is also specified. 4418 4419- CONFIG_SYS_QE_FMAN_FW_LENGTH 4420 The maximum possible size of the firmware. The firmware binary format 4421 has a field that specifies the actual size of the firmware, but it 4422 might not be possible to read any part of the firmware unless some 4423 local storage is allocated to hold the entire firmware first. 4424 4425- CONFIG_SYS_QE_FMAN_FW_IN_NOR 4426 Specifies that QE/FMAN firmware is located in NOR flash, mapped as 4427 normal addressable memory via the LBC. CONFIG_SYS_FMAN_FW_ADDR is the 4428 virtual address in NOR flash. 4429 4430- CONFIG_SYS_QE_FMAN_FW_IN_NAND 4431 Specifies that QE/FMAN firmware is located in NAND flash. 4432 CONFIG_SYS_FMAN_FW_ADDR is the offset within NAND flash. 4433 4434- CONFIG_SYS_QE_FMAN_FW_IN_MMC 4435 Specifies that QE/FMAN firmware is located on the primary SD/MMC 4436 device. CONFIG_SYS_FMAN_FW_ADDR is the byte offset on that device. 4437 4438- CONFIG_SYS_QE_FMAN_FW_IN_REMOTE 4439 Specifies that QE/FMAN firmware is located in the remote (master) 4440 memory space. CONFIG_SYS_FMAN_FW_ADDR is a virtual address which 4441 can be mapped from slave TLB->slave LAW->slave SRIO or PCIE outbound 4442 window->master inbound window->master LAW->the ucode address in 4443 master's memory space. 4444 4445Freescale Layerscape Management Complex Firmware Support: 4446--------------------------------------------------------- 4447The Freescale Layerscape Management Complex (MC) supports the loading of 4448"firmware". 4449This firmware often needs to be loaded during U-Boot booting, so macros 4450are used to identify the storage device (NOR flash, SPI, etc) and the address 4451within that device. 4452 4453- CONFIG_FSL_MC_ENET 4454 Enable the MC driver for Layerscape SoCs. 4455 4456Freescale Layerscape Debug Server Support: 4457------------------------------------------- 4458The Freescale Layerscape Debug Server Support supports the loading of 4459"Debug Server firmware" and triggering SP boot-rom. 4460This firmware often needs to be loaded during U-Boot booting. 4461 4462- CONFIG_SYS_MC_RSV_MEM_ALIGN 4463 Define alignment of reserved memory MC requires 4464 4465Reproducible builds 4466------------------- 4467 4468In order to achieve reproducible builds, timestamps used in the U-Boot build 4469process have to be set to a fixed value. 4470 4471This is done using the SOURCE_DATE_EPOCH environment variable. 4472SOURCE_DATE_EPOCH is to be set on the build host's shell, not as a configuration 4473option for U-Boot or an environment variable in U-Boot. 4474 4475SOURCE_DATE_EPOCH should be set to a number of seconds since the epoch, in UTC. 4476 4477Building the Software: 4478====================== 4479 4480Building U-Boot has been tested in several native build environments 4481and in many different cross environments. Of course we cannot support 4482all possibly existing versions of cross development tools in all 4483(potentially obsolete) versions. In case of tool chain problems we 4484recommend to use the ELDK (see http://www.denx.de/wiki/DULG/ELDK) 4485which is extensively used to build and test U-Boot. 4486 4487If you are not using a native environment, it is assumed that you 4488have GNU cross compiling tools available in your path. In this case, 4489you must set the environment variable CROSS_COMPILE in your shell. 4490Note that no changes to the Makefile or any other source files are 4491necessary. For example using the ELDK on a 4xx CPU, please enter: 4492 4493 $ CROSS_COMPILE=ppc_4xx- 4494 $ export CROSS_COMPILE 4495 4496Note: If you wish to generate Windows versions of the utilities in 4497 the tools directory you can use the MinGW toolchain 4498 (http://www.mingw.org). Set your HOST tools to the MinGW 4499 toolchain and execute 'make tools'. For example: 4500 4501 $ make HOSTCC=i586-mingw32msvc-gcc HOSTSTRIP=i586-mingw32msvc-strip tools 4502 4503 Binaries such as tools/mkimage.exe will be created which can 4504 be executed on computers running Windows. 4505 4506U-Boot is intended to be simple to build. After installing the 4507sources you must configure U-Boot for one specific board type. This 4508is done by typing: 4509 4510 make NAME_defconfig 4511 4512where "NAME_defconfig" is the name of one of the existing configu- 4513rations; see boards.cfg for supported names. 4514 4515Note: for some board special configuration names may exist; check if 4516 additional information is available from the board vendor; for 4517 instance, the TQM823L systems are available without (standard) 4518 or with LCD support. You can select such additional "features" 4519 when choosing the configuration, i. e. 4520 4521 make TQM823L_defconfig 4522 - will configure for a plain TQM823L, i. e. no LCD support 4523 4524 make TQM823L_LCD_defconfig 4525 - will configure for a TQM823L with U-Boot console on LCD 4526 4527 etc. 4528 4529 4530Finally, type "make all", and you should get some working U-Boot 4531images ready for download to / installation on your system: 4532 4533- "u-boot.bin" is a raw binary image 4534- "u-boot" is an image in ELF binary format 4535- "u-boot.srec" is in Motorola S-Record format 4536 4537By default the build is performed locally and the objects are saved 4538in the source directory. One of the two methods can be used to change 4539this behavior and build U-Boot to some external directory: 4540 45411. Add O= to the make command line invocations: 4542 4543 make O=/tmp/build distclean 4544 make O=/tmp/build NAME_defconfig 4545 make O=/tmp/build all 4546 45472. Set environment variable KBUILD_OUTPUT to point to the desired location: 4548 4549 export KBUILD_OUTPUT=/tmp/build 4550 make distclean 4551 make NAME_defconfig 4552 make all 4553 4554Note that the command line "O=" setting overrides the KBUILD_OUTPUT environment 4555variable. 4556 4557 4558Please be aware that the Makefiles assume you are using GNU make, so 4559for instance on NetBSD you might need to use "gmake" instead of 4560native "make". 4561 4562 4563If the system board that you have is not listed, then you will need 4564to port U-Boot to your hardware platform. To do this, follow these 4565steps: 4566 45671. Create a new directory to hold your board specific code. Add any 4568 files you need. In your board directory, you will need at least 4569 the "Makefile" and a "<board>.c". 45702. Create a new configuration file "include/configs/<board>.h" for 4571 your board. 45723. If you're porting U-Boot to a new CPU, then also create a new 4573 directory to hold your CPU specific code. Add any files you need. 45744. Run "make <board>_defconfig" with your new name. 45755. Type "make", and you should get a working "u-boot.srec" file 4576 to be installed on your target system. 45776. Debug and solve any problems that might arise. 4578 [Of course, this last step is much harder than it sounds.] 4579 4580 4581Testing of U-Boot Modifications, Ports to New Hardware, etc.: 4582============================================================== 4583 4584If you have modified U-Boot sources (for instance added a new board 4585or support for new devices, a new CPU, etc.) you are expected to 4586provide feedback to the other developers. The feedback normally takes 4587the form of a "patch", i. e. a context diff against a certain (latest 4588official or latest in the git repository) version of U-Boot sources. 4589 4590But before you submit such a patch, please verify that your modifi- 4591cation did not break existing code. At least make sure that *ALL* of 4592the supported boards compile WITHOUT ANY compiler warnings. To do so, 4593just run the buildman script (tools/buildman/buildman), which will 4594configure and build U-Boot for ALL supported system. Be warned, this 4595will take a while. Please see the buildman README, or run 'buildman -H' 4596for documentation. 4597 4598 4599See also "U-Boot Porting Guide" below. 4600 4601 4602Monitor Commands - Overview: 4603============================ 4604 4605go - start application at address 'addr' 4606run - run commands in an environment variable 4607bootm - boot application image from memory 4608bootp - boot image via network using BootP/TFTP protocol 4609bootz - boot zImage from memory 4610tftpboot- boot image via network using TFTP protocol 4611 and env variables "ipaddr" and "serverip" 4612 (and eventually "gatewayip") 4613tftpput - upload a file via network using TFTP protocol 4614rarpboot- boot image via network using RARP/TFTP protocol 4615diskboot- boot from IDE devicebootd - boot default, i.e., run 'bootcmd' 4616loads - load S-Record file over serial line 4617loadb - load binary file over serial line (kermit mode) 4618md - memory display 4619mm - memory modify (auto-incrementing) 4620nm - memory modify (constant address) 4621mw - memory write (fill) 4622cp - memory copy 4623cmp - memory compare 4624crc32 - checksum calculation 4625i2c - I2C sub-system 4626sspi - SPI utility commands 4627base - print or set address offset 4628printenv- print environment variables 4629setenv - set environment variables 4630saveenv - save environment variables to persistent storage 4631protect - enable or disable FLASH write protection 4632erase - erase FLASH memory 4633flinfo - print FLASH memory information 4634nand - NAND memory operations (see doc/README.nand) 4635bdinfo - print Board Info structure 4636iminfo - print header information for application image 4637coninfo - print console devices and informations 4638ide - IDE sub-system 4639loop - infinite loop on address range 4640loopw - infinite write loop on address range 4641mtest - simple RAM test 4642icache - enable or disable instruction cache 4643dcache - enable or disable data cache 4644reset - Perform RESET of the CPU 4645echo - echo args to console 4646version - print monitor version 4647help - print online help 4648? - alias for 'help' 4649 4650 4651Monitor Commands - Detailed Description: 4652======================================== 4653 4654TODO. 4655 4656For now: just type "help <command>". 4657 4658 4659Environment Variables: 4660====================== 4661 4662U-Boot supports user configuration using Environment Variables which 4663can be made persistent by saving to Flash memory. 4664 4665Environment Variables are set using "setenv", printed using 4666"printenv", and saved to Flash using "saveenv". Using "setenv" 4667without a value can be used to delete a variable from the 4668environment. As long as you don't save the environment you are 4669working with an in-memory copy. In case the Flash area containing the 4670environment is erased by accident, a default environment is provided. 4671 4672Some configuration options can be set using Environment Variables. 4673 4674List of environment variables (most likely not complete): 4675 4676 baudrate - see CONFIG_BAUDRATE 4677 4678 bootdelay - see CONFIG_BOOTDELAY 4679 4680 bootcmd - see CONFIG_BOOTCOMMAND 4681 4682 bootargs - Boot arguments when booting an RTOS image 4683 4684 bootfile - Name of the image to load with TFTP 4685 4686 bootm_low - Memory range available for image processing in the bootm 4687 command can be restricted. This variable is given as 4688 a hexadecimal number and defines lowest address allowed 4689 for use by the bootm command. See also "bootm_size" 4690 environment variable. Address defined by "bootm_low" is 4691 also the base of the initial memory mapping for the Linux 4692 kernel -- see the description of CONFIG_SYS_BOOTMAPSZ and 4693 bootm_mapsize. 4694 4695 bootm_mapsize - Size of the initial memory mapping for the Linux kernel. 4696 This variable is given as a hexadecimal number and it 4697 defines the size of the memory region starting at base 4698 address bootm_low that is accessible by the Linux kernel 4699 during early boot. If unset, CONFIG_SYS_BOOTMAPSZ is used 4700 as the default value if it is defined, and bootm_size is 4701 used otherwise. 4702 4703 bootm_size - Memory range available for image processing in the bootm 4704 command can be restricted. This variable is given as 4705 a hexadecimal number and defines the size of the region 4706 allowed for use by the bootm command. See also "bootm_low" 4707 environment variable. 4708 4709 updatefile - Location of the software update file on a TFTP server, used 4710 by the automatic software update feature. Please refer to 4711 documentation in doc/README.update for more details. 4712 4713 autoload - if set to "no" (any string beginning with 'n'), 4714 "bootp" will just load perform a lookup of the 4715 configuration from the BOOTP server, but not try to 4716 load any image using TFTP 4717 4718 autostart - if set to "yes", an image loaded using the "bootp", 4719 "rarpboot", "tftpboot" or "diskboot" commands will 4720 be automatically started (by internally calling 4721 "bootm") 4722 4723 If set to "no", a standalone image passed to the 4724 "bootm" command will be copied to the load address 4725 (and eventually uncompressed), but NOT be started. 4726 This can be used to load and uncompress arbitrary 4727 data. 4728 4729 fdt_high - if set this restricts the maximum address that the 4730 flattened device tree will be copied into upon boot. 4731 For example, if you have a system with 1 GB memory 4732 at physical address 0x10000000, while Linux kernel 4733 only recognizes the first 704 MB as low memory, you 4734 may need to set fdt_high as 0x3C000000 to have the 4735 device tree blob be copied to the maximum address 4736 of the 704 MB low memory, so that Linux kernel can 4737 access it during the boot procedure. 4738 4739 If this is set to the special value 0xFFFFFFFF then 4740 the fdt will not be copied at all on boot. For this 4741 to work it must reside in writable memory, have 4742 sufficient padding on the end of it for u-boot to 4743 add the information it needs into it, and the memory 4744 must be accessible by the kernel. 4745 4746 fdtcontroladdr- if set this is the address of the control flattened 4747 device tree used by U-Boot when CONFIG_OF_CONTROL is 4748 defined. 4749 4750 i2cfast - (PPC405GP|PPC405EP only) 4751 if set to 'y' configures Linux I2C driver for fast 4752 mode (400kHZ). This environment variable is used in 4753 initialization code. So, for changes to be effective 4754 it must be saved and board must be reset. 4755 4756 initrd_high - restrict positioning of initrd images: 4757 If this variable is not set, initrd images will be 4758 copied to the highest possible address in RAM; this 4759 is usually what you want since it allows for 4760 maximum initrd size. If for some reason you want to 4761 make sure that the initrd image is loaded below the 4762 CONFIG_SYS_BOOTMAPSZ limit, you can set this environment 4763 variable to a value of "no" or "off" or "0". 4764 Alternatively, you can set it to a maximum upper 4765 address to use (U-Boot will still check that it 4766 does not overwrite the U-Boot stack and data). 4767 4768 For instance, when you have a system with 16 MB 4769 RAM, and want to reserve 4 MB from use by Linux, 4770 you can do this by adding "mem=12M" to the value of 4771 the "bootargs" variable. However, now you must make 4772 sure that the initrd image is placed in the first 4773 12 MB as well - this can be done with 4774 4775 setenv initrd_high 00c00000 4776 4777 If you set initrd_high to 0xFFFFFFFF, this is an 4778 indication to U-Boot that all addresses are legal 4779 for the Linux kernel, including addresses in flash 4780 memory. In this case U-Boot will NOT COPY the 4781 ramdisk at all. This may be useful to reduce the 4782 boot time on your system, but requires that this 4783 feature is supported by your Linux kernel. 4784 4785 ipaddr - IP address; needed for tftpboot command 4786 4787 loadaddr - Default load address for commands like "bootp", 4788 "rarpboot", "tftpboot", "loadb" or "diskboot" 4789 4790 loads_echo - see CONFIG_LOADS_ECHO 4791 4792 serverip - TFTP server IP address; needed for tftpboot command 4793 4794 bootretry - see CONFIG_BOOT_RETRY_TIME 4795 4796 bootdelaykey - see CONFIG_AUTOBOOT_DELAY_STR 4797 4798 bootstopkey - see CONFIG_AUTOBOOT_STOP_STR 4799 4800 ethprime - controls which interface is used first. 4801 4802 ethact - controls which interface is currently active. 4803 For example you can do the following 4804 4805 => setenv ethact FEC 4806 => ping 192.168.0.1 # traffic sent on FEC 4807 => setenv ethact SCC 4808 => ping 10.0.0.1 # traffic sent on SCC 4809 4810 ethrotate - When set to "no" U-Boot does not go through all 4811 available network interfaces. 4812 It just stays at the currently selected interface. 4813 4814 netretry - When set to "no" each network operation will 4815 either succeed or fail without retrying. 4816 When set to "once" the network operation will 4817 fail when all the available network interfaces 4818 are tried once without success. 4819 Useful on scripts which control the retry operation 4820 themselves. 4821 4822 npe_ucode - set load address for the NPE microcode 4823 4824 silent_linux - If set then Linux will be told to boot silently, by 4825 changing the console to be empty. If "yes" it will be 4826 made silent. If "no" it will not be made silent. If 4827 unset, then it will be made silent if the U-Boot console 4828 is silent. 4829 4830 tftpsrcp - If this is set, the value is used for TFTP's 4831 UDP source port. 4832 4833 tftpdstp - If this is set, the value is used for TFTP's UDP 4834 destination port instead of the Well Know Port 69. 4835 4836 tftpblocksize - Block size to use for TFTP transfers; if not set, 4837 we use the TFTP server's default block size 4838 4839 tftptimeout - Retransmission timeout for TFTP packets (in milli- 4840 seconds, minimum value is 1000 = 1 second). Defines 4841 when a packet is considered to be lost so it has to 4842 be retransmitted. The default is 5000 = 5 seconds. 4843 Lowering this value may make downloads succeed 4844 faster in networks with high packet loss rates or 4845 with unreliable TFTP servers. 4846 4847 tftptimeoutcountmax - maximum count of TFTP timeouts (no 4848 unit, minimum value = 0). Defines how many timeouts 4849 can happen during a single file transfer before that 4850 transfer is aborted. The default is 10, and 0 means 4851 'no timeouts allowed'. Increasing this value may help 4852 downloads succeed with high packet loss rates, or with 4853 unreliable TFTP servers or client hardware. 4854 4855 vlan - When set to a value < 4095 the traffic over 4856 Ethernet is encapsulated/received over 802.1q 4857 VLAN tagged frames. 4858 4859 bootpretryperiod - Period during which BOOTP/DHCP sends retries. 4860 Unsigned value, in milliseconds. If not set, the period will 4861 be either the default (28000), or a value based on 4862 CONFIG_NET_RETRY_COUNT, if defined. This value has 4863 precedence over the valu based on CONFIG_NET_RETRY_COUNT. 4864 4865The following image location variables contain the location of images 4866used in booting. The "Image" column gives the role of the image and is 4867not an environment variable name. The other columns are environment 4868variable names. "File Name" gives the name of the file on a TFTP 4869server, "RAM Address" gives the location in RAM the image will be 4870loaded to, and "Flash Location" gives the image's address in NOR 4871flash or offset in NAND flash. 4872 4873*Note* - these variables don't have to be defined for all boards, some 4874boards currently use other variables for these purposes, and some 4875boards use these variables for other purposes. 4876 4877Image File Name RAM Address Flash Location 4878----- --------- ----------- -------------- 4879u-boot u-boot u-boot_addr_r u-boot_addr 4880Linux kernel bootfile kernel_addr_r kernel_addr 4881device tree blob fdtfile fdt_addr_r fdt_addr 4882ramdisk ramdiskfile ramdisk_addr_r ramdisk_addr 4883 4884The following environment variables may be used and automatically 4885updated by the network boot commands ("bootp" and "rarpboot"), 4886depending the information provided by your boot server: 4887 4888 bootfile - see above 4889 dnsip - IP address of your Domain Name Server 4890 dnsip2 - IP address of your secondary Domain Name Server 4891 gatewayip - IP address of the Gateway (Router) to use 4892 hostname - Target hostname 4893 ipaddr - see above 4894 netmask - Subnet Mask 4895 rootpath - Pathname of the root filesystem on the NFS server 4896 serverip - see above 4897 4898 4899There are two special Environment Variables: 4900 4901 serial# - contains hardware identification information such 4902 as type string and/or serial number 4903 ethaddr - Ethernet address 4904 4905These variables can be set only once (usually during manufacturing of 4906the board). U-Boot refuses to delete or overwrite these variables 4907once they have been set once. 4908 4909 4910Further special Environment Variables: 4911 4912 ver - Contains the U-Boot version string as printed 4913 with the "version" command. This variable is 4914 readonly (see CONFIG_VERSION_VARIABLE). 4915 4916 4917Please note that changes to some configuration parameters may take 4918only effect after the next boot (yes, that's just like Windoze :-). 4919 4920 4921Callback functions for environment variables: 4922--------------------------------------------- 4923 4924For some environment variables, the behavior of u-boot needs to change 4925when their values are changed. This functionality allows functions to 4926be associated with arbitrary variables. On creation, overwrite, or 4927deletion, the callback will provide the opportunity for some side 4928effect to happen or for the change to be rejected. 4929 4930The callbacks are named and associated with a function using the 4931U_BOOT_ENV_CALLBACK macro in your board or driver code. 4932 4933These callbacks are associated with variables in one of two ways. The 4934static list can be added to by defining CONFIG_ENV_CALLBACK_LIST_STATIC 4935in the board configuration to a string that defines a list of 4936associations. The list must be in the following format: 4937 4938 entry = variable_name[:callback_name] 4939 list = entry[,list] 4940 4941If the callback name is not specified, then the callback is deleted. 4942Spaces are also allowed anywhere in the list. 4943 4944Callbacks can also be associated by defining the ".callbacks" variable 4945with the same list format above. Any association in ".callbacks" will 4946override any association in the static list. You can define 4947CONFIG_ENV_CALLBACK_LIST_DEFAULT to a list (string) to define the 4948".callbacks" environment variable in the default or embedded environment. 4949 4950If CONFIG_REGEX is defined, the variable_name above is evaluated as a 4951regular expression. This allows multiple variables to be connected to 4952the same callback without explicitly listing them all out. 4953 4954 4955Command Line Parsing: 4956===================== 4957 4958There are two different command line parsers available with U-Boot: 4959the old "simple" one, and the much more powerful "hush" shell: 4960 4961Old, simple command line parser: 4962-------------------------------- 4963 4964- supports environment variables (through setenv / saveenv commands) 4965- several commands on one line, separated by ';' 4966- variable substitution using "... ${name} ..." syntax 4967- special characters ('$', ';') can be escaped by prefixing with '\', 4968 for example: 4969 setenv bootcmd bootm \${address} 4970- You can also escape text by enclosing in single apostrophes, for example: 4971 setenv addip 'setenv bootargs $bootargs ip=$ipaddr:$serverip:$gatewayip:$netmask:$hostname::off' 4972 4973Hush shell: 4974----------- 4975 4976- similar to Bourne shell, with control structures like 4977 if...then...else...fi, for...do...done; while...do...done, 4978 until...do...done, ... 4979- supports environment ("global") variables (through setenv / saveenv 4980 commands) and local shell variables (through standard shell syntax 4981 "name=value"); only environment variables can be used with "run" 4982 command 4983 4984General rules: 4985-------------- 4986 4987(1) If a command line (or an environment variable executed by a "run" 4988 command) contains several commands separated by semicolon, and 4989 one of these commands fails, then the remaining commands will be 4990 executed anyway. 4991 4992(2) If you execute several variables with one call to run (i. e. 4993 calling run with a list of variables as arguments), any failing 4994 command will cause "run" to terminate, i. e. the remaining 4995 variables are not executed. 4996 4997Note for Redundant Ethernet Interfaces: 4998======================================= 4999 5000Some boards come with redundant Ethernet interfaces; U-Boot supports 5001such configurations and is capable of automatic selection of a 5002"working" interface when needed. MAC assignment works as follows: 5003 5004Network interfaces are numbered eth0, eth1, eth2, ... Corresponding 5005MAC addresses can be stored in the environment as "ethaddr" (=>eth0), 5006"eth1addr" (=>eth1), "eth2addr", ... 5007 5008If the network interface stores some valid MAC address (for instance 5009in SROM), this is used as default address if there is NO correspon- 5010ding setting in the environment; if the corresponding environment 5011variable is set, this overrides the settings in the card; that means: 5012 5013o If the SROM has a valid MAC address, and there is no address in the 5014 environment, the SROM's address is used. 5015 5016o If there is no valid address in the SROM, and a definition in the 5017 environment exists, then the value from the environment variable is 5018 used. 5019 5020o If both the SROM and the environment contain a MAC address, and 5021 both addresses are the same, this MAC address is used. 5022 5023o If both the SROM and the environment contain a MAC address, and the 5024 addresses differ, the value from the environment is used and a 5025 warning is printed. 5026 5027o If neither SROM nor the environment contain a MAC address, an error 5028 is raised. If CONFIG_NET_RANDOM_ETHADDR is defined, then in this case 5029 a random, locally-assigned MAC is used. 5030 5031If Ethernet drivers implement the 'write_hwaddr' function, valid MAC addresses 5032will be programmed into hardware as part of the initialization process. This 5033may be skipped by setting the appropriate 'ethmacskip' environment variable. 5034The naming convention is as follows: 5035"ethmacskip" (=>eth0), "eth1macskip" (=>eth1) etc. 5036 5037Image Formats: 5038============== 5039 5040U-Boot is capable of booting (and performing other auxiliary operations on) 5041images in two formats: 5042 5043New uImage format (FIT) 5044----------------------- 5045 5046Flexible and powerful format based on Flattened Image Tree -- FIT (similar 5047to Flattened Device Tree). It allows the use of images with multiple 5048components (several kernels, ramdisks, etc.), with contents protected by 5049SHA1, MD5 or CRC32. More details are found in the doc/uImage.FIT directory. 5050 5051 5052Old uImage format 5053----------------- 5054 5055Old image format is based on binary files which can be basically anything, 5056preceded by a special header; see the definitions in include/image.h for 5057details; basically, the header defines the following image properties: 5058 5059* Target Operating System (Provisions for OpenBSD, NetBSD, FreeBSD, 5060 4.4BSD, Linux, SVR4, Esix, Solaris, Irix, SCO, Dell, NCR, VxWorks, 5061 LynxOS, pSOS, QNX, RTEMS, INTEGRITY; 5062 Currently supported: Linux, NetBSD, VxWorks, QNX, RTEMS, LynxOS, 5063 INTEGRITY). 5064* Target CPU Architecture (Provisions for Alpha, ARM, AVR32, Intel x86, 5065 IA64, MIPS, NDS32, Nios II, PowerPC, IBM S390, SuperH, Sparc, Sparc 64 Bit; 5066 Currently supported: ARM, AVR32, Intel x86, MIPS, NDS32, Nios II, PowerPC). 5067* Compression Type (uncompressed, gzip, bzip2) 5068* Load Address 5069* Entry Point 5070* Image Name 5071* Image Timestamp 5072 5073The header is marked by a special Magic Number, and both the header 5074and the data portions of the image are secured against corruption by 5075CRC32 checksums. 5076 5077 5078Linux Support: 5079============== 5080 5081Although U-Boot should support any OS or standalone application 5082easily, the main focus has always been on Linux during the design of 5083U-Boot. 5084 5085U-Boot includes many features that so far have been part of some 5086special "boot loader" code within the Linux kernel. Also, any 5087"initrd" images to be used are no longer part of one big Linux image; 5088instead, kernel and "initrd" are separate images. This implementation 5089serves several purposes: 5090 5091- the same features can be used for other OS or standalone 5092 applications (for instance: using compressed images to reduce the 5093 Flash memory footprint) 5094 5095- it becomes much easier to port new Linux kernel versions because 5096 lots of low-level, hardware dependent stuff are done by U-Boot 5097 5098- the same Linux kernel image can now be used with different "initrd" 5099 images; of course this also means that different kernel images can 5100 be run with the same "initrd". This makes testing easier (you don't 5101 have to build a new "zImage.initrd" Linux image when you just 5102 change a file in your "initrd"). Also, a field-upgrade of the 5103 software is easier now. 5104 5105 5106Linux HOWTO: 5107============ 5108 5109Porting Linux to U-Boot based systems: 5110--------------------------------------- 5111 5112U-Boot cannot save you from doing all the necessary modifications to 5113configure the Linux device drivers for use with your target hardware 5114(no, we don't intend to provide a full virtual machine interface to 5115Linux :-). 5116 5117But now you can ignore ALL boot loader code (in arch/powerpc/mbxboot). 5118 5119Just make sure your machine specific header file (for instance 5120include/asm-ppc/tqm8xx.h) includes the same definition of the Board 5121Information structure as we define in include/asm-<arch>/u-boot.h, 5122and make sure that your definition of IMAP_ADDR uses the same value 5123as your U-Boot configuration in CONFIG_SYS_IMMR. 5124 5125Note that U-Boot now has a driver model, a unified model for drivers. 5126If you are adding a new driver, plumb it into driver model. If there 5127is no uclass available, you are encouraged to create one. See 5128doc/driver-model. 5129 5130 5131Configuring the Linux kernel: 5132----------------------------- 5133 5134No specific requirements for U-Boot. Make sure you have some root 5135device (initial ramdisk, NFS) for your target system. 5136 5137 5138Building a Linux Image: 5139----------------------- 5140 5141With U-Boot, "normal" build targets like "zImage" or "bzImage" are 5142not used. If you use recent kernel source, a new build target 5143"uImage" will exist which automatically builds an image usable by 5144U-Boot. Most older kernels also have support for a "pImage" target, 5145which was introduced for our predecessor project PPCBoot and uses a 5146100% compatible format. 5147 5148Example: 5149 5150 make TQM850L_defconfig 5151 make oldconfig 5152 make dep 5153 make uImage 5154 5155The "uImage" build target uses a special tool (in 'tools/mkimage') to 5156encapsulate a compressed Linux kernel image with header information, 5157CRC32 checksum etc. for use with U-Boot. This is what we are doing: 5158 5159* build a standard "vmlinux" kernel image (in ELF binary format): 5160 5161* convert the kernel into a raw binary image: 5162 5163 ${CROSS_COMPILE}-objcopy -O binary \ 5164 -R .note -R .comment \ 5165 -S vmlinux linux.bin 5166 5167* compress the binary image: 5168 5169 gzip -9 linux.bin 5170 5171* package compressed binary image for U-Boot: 5172 5173 mkimage -A ppc -O linux -T kernel -C gzip \ 5174 -a 0 -e 0 -n "Linux Kernel Image" \ 5175 -d linux.bin.gz uImage 5176 5177 5178The "mkimage" tool can also be used to create ramdisk images for use 5179with U-Boot, either separated from the Linux kernel image, or 5180combined into one file. "mkimage" encapsulates the images with a 64 5181byte header containing information about target architecture, 5182operating system, image type, compression method, entry points, time 5183stamp, CRC32 checksums, etc. 5184 5185"mkimage" can be called in two ways: to verify existing images and 5186print the header information, or to build new images. 5187 5188In the first form (with "-l" option) mkimage lists the information 5189contained in the header of an existing U-Boot image; this includes 5190checksum verification: 5191 5192 tools/mkimage -l image 5193 -l ==> list image header information 5194 5195The second form (with "-d" option) is used to build a U-Boot image 5196from a "data file" which is used as image payload: 5197 5198 tools/mkimage -A arch -O os -T type -C comp -a addr -e ep \ 5199 -n name -d data_file image 5200 -A ==> set architecture to 'arch' 5201 -O ==> set operating system to 'os' 5202 -T ==> set image type to 'type' 5203 -C ==> set compression type 'comp' 5204 -a ==> set load address to 'addr' (hex) 5205 -e ==> set entry point to 'ep' (hex) 5206 -n ==> set image name to 'name' 5207 -d ==> use image data from 'datafile' 5208 5209Right now, all Linux kernels for PowerPC systems use the same load 5210address (0x00000000), but the entry point address depends on the 5211kernel version: 5212 5213- 2.2.x kernels have the entry point at 0x0000000C, 5214- 2.3.x and later kernels have the entry point at 0x00000000. 5215 5216So a typical call to build a U-Boot image would read: 5217 5218 -> tools/mkimage -n '2.4.4 kernel for TQM850L' \ 5219 > -A ppc -O linux -T kernel -C gzip -a 0 -e 0 \ 5220 > -d /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/powerpc/coffboot/vmlinux.gz \ 5221 > examples/uImage.TQM850L 5222 Image Name: 2.4.4 kernel for TQM850L 5223 Created: Wed Jul 19 02:34:59 2000 5224 Image Type: PowerPC Linux Kernel Image (gzip compressed) 5225 Data Size: 335725 Bytes = 327.86 kB = 0.32 MB 5226 Load Address: 0x00000000 5227 Entry Point: 0x00000000 5228 5229To verify the contents of the image (or check for corruption): 5230 5231 -> tools/mkimage -l examples/uImage.TQM850L 5232 Image Name: 2.4.4 kernel for TQM850L 5233 Created: Wed Jul 19 02:34:59 2000 5234 Image Type: PowerPC Linux Kernel Image (gzip compressed) 5235 Data Size: 335725 Bytes = 327.86 kB = 0.32 MB 5236 Load Address: 0x00000000 5237 Entry Point: 0x00000000 5238 5239NOTE: for embedded systems where boot time is critical you can trade 5240speed for memory and install an UNCOMPRESSED image instead: this 5241needs more space in Flash, but boots much faster since it does not 5242need to be uncompressed: 5243 5244 -> gunzip /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/powerpc/coffboot/vmlinux.gz 5245 -> tools/mkimage -n '2.4.4 kernel for TQM850L' \ 5246 > -A ppc -O linux -T kernel -C none -a 0 -e 0 \ 5247 > -d /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/powerpc/coffboot/vmlinux \ 5248 > examples/uImage.TQM850L-uncompressed 5249 Image Name: 2.4.4 kernel for TQM850L 5250 Created: Wed Jul 19 02:34:59 2000 5251 Image Type: PowerPC Linux Kernel Image (uncompressed) 5252 Data Size: 792160 Bytes = 773.59 kB = 0.76 MB 5253 Load Address: 0x00000000 5254 Entry Point: 0x00000000 5255 5256 5257Similar you can build U-Boot images from a 'ramdisk.image.gz' file 5258when your kernel is intended to use an initial ramdisk: 5259 5260 -> tools/mkimage -n 'Simple Ramdisk Image' \ 5261 > -A ppc -O linux -T ramdisk -C gzip \ 5262 > -d /LinuxPPC/images/SIMPLE-ramdisk.image.gz examples/simple-initrd 5263 Image Name: Simple Ramdisk Image 5264 Created: Wed Jan 12 14:01:50 2000 5265 Image Type: PowerPC Linux RAMDisk Image (gzip compressed) 5266 Data Size: 566530 Bytes = 553.25 kB = 0.54 MB 5267 Load Address: 0x00000000 5268 Entry Point: 0x00000000 5269 5270The "dumpimage" is a tool to disassemble images built by mkimage. Its "-i" 5271option performs the converse operation of the mkimage's second form (the "-d" 5272option). Given an image built by mkimage, the dumpimage extracts a "data file" 5273from the image: 5274 5275 tools/dumpimage -i image -T type -p position data_file 5276 -i ==> extract from the 'image' a specific 'data_file' 5277 -T ==> set image type to 'type' 5278 -p ==> 'position' (starting at 0) of the 'data_file' inside the 'image' 5279 5280 5281Installing a Linux Image: 5282------------------------- 5283 5284To downloading a U-Boot image over the serial (console) interface, 5285you must convert the image to S-Record format: 5286 5287 objcopy -I binary -O srec examples/image examples/image.srec 5288 5289The 'objcopy' does not understand the information in the U-Boot 5290image header, so the resulting S-Record file will be relative to 5291address 0x00000000. To load it to a given address, you need to 5292specify the target address as 'offset' parameter with the 'loads' 5293command. 5294 5295Example: install the image to address 0x40100000 (which on the 5296TQM8xxL is in the first Flash bank): 5297 5298 => erase 40100000 401FFFFF 5299 5300 .......... done 5301 Erased 8 sectors 5302 5303 => loads 40100000 5304 ## Ready for S-Record download ... 5305 ~>examples/image.srec 5306 1 2 3 4 5 6 7 8 9 10 11 12 13 ... 5307 ... 5308 15989 15990 15991 15992 5309 [file transfer complete] 5310 [connected] 5311 ## Start Addr = 0x00000000 5312 5313 5314You can check the success of the download using the 'iminfo' command; 5315this includes a checksum verification so you can be sure no data 5316corruption happened: 5317 5318 => imi 40100000 5319 5320 ## Checking Image at 40100000 ... 5321 Image Name: 2.2.13 for initrd on TQM850L 5322 Image Type: PowerPC Linux Kernel Image (gzip compressed) 5323 Data Size: 335725 Bytes = 327 kB = 0 MB 5324 Load Address: 00000000 5325 Entry Point: 0000000c 5326 Verifying Checksum ... OK 5327 5328 5329Boot Linux: 5330----------- 5331 5332The "bootm" command is used to boot an application that is stored in 5333memory (RAM or Flash). In case of a Linux kernel image, the contents 5334of the "bootargs" environment variable is passed to the kernel as 5335parameters. You can check and modify this variable using the 5336"printenv" and "setenv" commands: 5337 5338 5339 => printenv bootargs 5340 bootargs=root=/dev/ram 5341 5342 => setenv bootargs root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2 5343 5344 => printenv bootargs 5345 bootargs=root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2 5346 5347 => bootm 40020000 5348 ## Booting Linux kernel at 40020000 ... 5349 Image Name: 2.2.13 for NFS on TQM850L 5350 Image Type: PowerPC Linux Kernel Image (gzip compressed) 5351 Data Size: 381681 Bytes = 372 kB = 0 MB 5352 Load Address: 00000000 5353 Entry Point: 0000000c 5354 Verifying Checksum ... OK 5355 Uncompressing Kernel Image ... OK 5356 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 5357 Boot arguments: root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2 5358 time_init: decrementer frequency = 187500000/60 5359 Calibrating delay loop... 49.77 BogoMIPS 5360 Memory: 15208k available (700k kernel code, 444k data, 32k init) [c0000000,c1000000] 5361 ... 5362 5363If you want to boot a Linux kernel with initial RAM disk, you pass 5364the memory addresses of both the kernel and the initrd image (PPBCOOT 5365format!) to the "bootm" command: 5366 5367 => imi 40100000 40200000 5368 5369 ## Checking Image at 40100000 ... 5370 Image Name: 2.2.13 for initrd on TQM850L 5371 Image Type: PowerPC Linux Kernel Image (gzip compressed) 5372 Data Size: 335725 Bytes = 327 kB = 0 MB 5373 Load Address: 00000000 5374 Entry Point: 0000000c 5375 Verifying Checksum ... OK 5376 5377 ## Checking Image at 40200000 ... 5378 Image Name: Simple Ramdisk Image 5379 Image Type: PowerPC Linux RAMDisk Image (gzip compressed) 5380 Data Size: 566530 Bytes = 553 kB = 0 MB 5381 Load Address: 00000000 5382 Entry Point: 00000000 5383 Verifying Checksum ... OK 5384 5385 => bootm 40100000 40200000 5386 ## Booting Linux kernel at 40100000 ... 5387 Image Name: 2.2.13 for initrd on TQM850L 5388 Image Type: PowerPC Linux Kernel Image (gzip compressed) 5389 Data Size: 335725 Bytes = 327 kB = 0 MB 5390 Load Address: 00000000 5391 Entry Point: 0000000c 5392 Verifying Checksum ... OK 5393 Uncompressing Kernel Image ... OK 5394 ## Loading RAMDisk Image at 40200000 ... 5395 Image Name: Simple Ramdisk Image 5396 Image Type: PowerPC Linux RAMDisk Image (gzip compressed) 5397 Data Size: 566530 Bytes = 553 kB = 0 MB 5398 Load Address: 00000000 5399 Entry Point: 00000000 5400 Verifying Checksum ... OK 5401 Loading Ramdisk ... OK 5402 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 5403 Boot arguments: root=/dev/ram 5404 time_init: decrementer frequency = 187500000/60 5405 Calibrating delay loop... 49.77 BogoMIPS 5406 ... 5407 RAMDISK: Compressed image found at block 0 5408 VFS: Mounted root (ext2 filesystem). 5409 5410 bash# 5411 5412Boot Linux and pass a flat device tree: 5413----------- 5414 5415First, U-Boot must be compiled with the appropriate defines. See the section 5416titled "Linux Kernel Interface" above for a more in depth explanation. The 5417following is an example of how to start a kernel and pass an updated 5418flat device tree: 5419 5420=> print oftaddr 5421oftaddr=0x300000 5422=> print oft 5423oft=oftrees/mpc8540ads.dtb 5424=> tftp $oftaddr $oft 5425Speed: 1000, full duplex 5426Using TSEC0 device 5427TFTP from server 192.168.1.1; our IP address is 192.168.1.101 5428Filename 'oftrees/mpc8540ads.dtb'. 5429Load address: 0x300000 5430Loading: # 5431done 5432Bytes transferred = 4106 (100a hex) 5433=> tftp $loadaddr $bootfile 5434Speed: 1000, full duplex 5435Using TSEC0 device 5436TFTP from server 192.168.1.1; our IP address is 192.168.1.2 5437Filename 'uImage'. 5438Load address: 0x200000 5439Loading:############ 5440done 5441Bytes transferred = 1029407 (fb51f hex) 5442=> print loadaddr 5443loadaddr=200000 5444=> print oftaddr 5445oftaddr=0x300000 5446=> bootm $loadaddr - $oftaddr 5447## Booting image at 00200000 ... 5448 Image Name: Linux-2.6.17-dirty 5449 Image Type: PowerPC Linux Kernel Image (gzip compressed) 5450 Data Size: 1029343 Bytes = 1005.2 kB 5451 Load Address: 00000000 5452 Entry Point: 00000000 5453 Verifying Checksum ... OK 5454 Uncompressing Kernel Image ... OK 5455Booting using flat device tree at 0x300000 5456Using MPC85xx ADS machine description 5457Memory CAM mapping: CAM0=256Mb, CAM1=256Mb, CAM2=0Mb residual: 0Mb 5458[snip] 5459 5460 5461More About U-Boot Image Types: 5462------------------------------ 5463 5464U-Boot supports the following image types: 5465 5466 "Standalone Programs" are directly runnable in the environment 5467 provided by U-Boot; it is expected that (if they behave 5468 well) you can continue to work in U-Boot after return from 5469 the Standalone Program. 5470 "OS Kernel Images" are usually images of some Embedded OS which 5471 will take over control completely. Usually these programs 5472 will install their own set of exception handlers, device 5473 drivers, set up the MMU, etc. - this means, that you cannot 5474 expect to re-enter U-Boot except by resetting the CPU. 5475 "RAMDisk Images" are more or less just data blocks, and their 5476 parameters (address, size) are passed to an OS kernel that is 5477 being started. 5478 "Multi-File Images" contain several images, typically an OS 5479 (Linux) kernel image and one or more data images like 5480 RAMDisks. This construct is useful for instance when you want 5481 to boot over the network using BOOTP etc., where the boot 5482 server provides just a single image file, but you want to get 5483 for instance an OS kernel and a RAMDisk image. 5484 5485 "Multi-File Images" start with a list of image sizes, each 5486 image size (in bytes) specified by an "uint32_t" in network 5487 byte order. This list is terminated by an "(uint32_t)0". 5488 Immediately after the terminating 0 follow the images, one by 5489 one, all aligned on "uint32_t" boundaries (size rounded up to 5490 a multiple of 4 bytes). 5491 5492 "Firmware Images" are binary images containing firmware (like 5493 U-Boot or FPGA images) which usually will be programmed to 5494 flash memory. 5495 5496 "Script files" are command sequences that will be executed by 5497 U-Boot's command interpreter; this feature is especially 5498 useful when you configure U-Boot to use a real shell (hush) 5499 as command interpreter. 5500 5501Booting the Linux zImage: 5502------------------------- 5503 5504On some platforms, it's possible to boot Linux zImage. This is done 5505using the "bootz" command. The syntax of "bootz" command is the same 5506as the syntax of "bootm" command. 5507 5508Note, defining the CONFIG_SUPPORT_RAW_INITRD allows user to supply 5509kernel with raw initrd images. The syntax is slightly different, the 5510address of the initrd must be augmented by it's size, in the following 5511format: "<initrd addres>:<initrd size>". 5512 5513 5514Standalone HOWTO: 5515================= 5516 5517One of the features of U-Boot is that you can dynamically load and 5518run "standalone" applications, which can use some resources of 5519U-Boot like console I/O functions or interrupt services. 5520 5521Two simple examples are included with the sources: 5522 5523"Hello World" Demo: 5524------------------- 5525 5526'examples/hello_world.c' contains a small "Hello World" Demo 5527application; it is automatically compiled when you build U-Boot. 5528It's configured to run at address 0x00040004, so you can play with it 5529like that: 5530 5531 => loads 5532 ## Ready for S-Record download ... 5533 ~>examples/hello_world.srec 5534 1 2 3 4 5 6 7 8 9 10 11 ... 5535 [file transfer complete] 5536 [connected] 5537 ## Start Addr = 0x00040004 5538 5539 => go 40004 Hello World! This is a test. 5540 ## Starting application at 0x00040004 ... 5541 Hello World 5542 argc = 7 5543 argv[0] = "40004" 5544 argv[1] = "Hello" 5545 argv[2] = "World!" 5546 argv[3] = "This" 5547 argv[4] = "is" 5548 argv[5] = "a" 5549 argv[6] = "test." 5550 argv[7] = "<NULL>" 5551 Hit any key to exit ... 5552 5553 ## Application terminated, rc = 0x0 5554 5555Another example, which demonstrates how to register a CPM interrupt 5556handler with the U-Boot code, can be found in 'examples/timer.c'. 5557Here, a CPM timer is set up to generate an interrupt every second. 5558The interrupt service routine is trivial, just printing a '.' 5559character, but this is just a demo program. The application can be 5560controlled by the following keys: 5561 5562 ? - print current values og the CPM Timer registers 5563 b - enable interrupts and start timer 5564 e - stop timer and disable interrupts 5565 q - quit application 5566 5567 => loads 5568 ## Ready for S-Record download ... 5569 ~>examples/timer.srec 5570 1 2 3 4 5 6 7 8 9 10 11 ... 5571 [file transfer complete] 5572 [connected] 5573 ## Start Addr = 0x00040004 5574 5575 => go 40004 5576 ## Starting application at 0x00040004 ... 5577 TIMERS=0xfff00980 5578 Using timer 1 5579 tgcr @ 0xfff00980, tmr @ 0xfff00990, trr @ 0xfff00994, tcr @ 0xfff00998, tcn @ 0xfff0099c, ter @ 0xfff009b0 5580 5581Hit 'b': 5582 [q, b, e, ?] Set interval 1000000 us 5583 Enabling timer 5584Hit '?': 5585 [q, b, e, ?] ........ 5586 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0xef6, ter=0x0 5587Hit '?': 5588 [q, b, e, ?] . 5589 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x2ad4, ter=0x0 5590Hit '?': 5591 [q, b, e, ?] . 5592 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x1efc, ter=0x0 5593Hit '?': 5594 [q, b, e, ?] . 5595 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x169d, ter=0x0 5596Hit 'e': 5597 [q, b, e, ?] ...Stopping timer 5598Hit 'q': 5599 [q, b, e, ?] ## Application terminated, rc = 0x0 5600 5601 5602Minicom warning: 5603================ 5604 5605Over time, many people have reported problems when trying to use the 5606"minicom" terminal emulation program for serial download. I (wd) 5607consider minicom to be broken, and recommend not to use it. Under 5608Unix, I recommend to use C-Kermit for general purpose use (and 5609especially for kermit binary protocol download ("loadb" command), and 5610use "cu" for S-Record download ("loads" command). See 5611http://www.denx.de/wiki/view/DULG/SystemSetup#Section_4.3. 5612for help with kermit. 5613 5614 5615Nevertheless, if you absolutely want to use it try adding this 5616configuration to your "File transfer protocols" section: 5617 5618 Name Program Name U/D FullScr IO-Red. Multi 5619 X kermit /usr/bin/kermit -i -l %l -s Y U Y N N 5620 Y kermit /usr/bin/kermit -i -l %l -r N D Y N N 5621 5622 5623NetBSD Notes: 5624============= 5625 5626Starting at version 0.9.2, U-Boot supports NetBSD both as host 5627(build U-Boot) and target system (boots NetBSD/mpc8xx). 5628 5629Building requires a cross environment; it is known to work on 5630NetBSD/i386 with the cross-powerpc-netbsd-1.3 package (you will also 5631need gmake since the Makefiles are not compatible with BSD make). 5632Note that the cross-powerpc package does not install include files; 5633attempting to build U-Boot will fail because <machine/ansi.h> is 5634missing. This file has to be installed and patched manually: 5635 5636 # cd /usr/pkg/cross/powerpc-netbsd/include 5637 # mkdir powerpc 5638 # ln -s powerpc machine 5639 # cp /usr/src/sys/arch/powerpc/include/ansi.h powerpc/ansi.h 5640 # ${EDIT} powerpc/ansi.h ## must remove __va_list, _BSD_VA_LIST 5641 5642Native builds *don't* work due to incompatibilities between native 5643and U-Boot include files. 5644 5645Booting assumes that (the first part of) the image booted is a 5646stage-2 loader which in turn loads and then invokes the kernel 5647proper. Loader sources will eventually appear in the NetBSD source 5648tree (probably in sys/arc/mpc8xx/stand/u-boot_stage2/); in the 5649meantime, see ftp://ftp.denx.de/pub/u-boot/ppcboot_stage2.tar.gz 5650 5651 5652Implementation Internals: 5653========================= 5654 5655The following is not intended to be a complete description of every 5656implementation detail. However, it should help to understand the 5657inner workings of U-Boot and make it easier to port it to custom 5658hardware. 5659 5660 5661Initial Stack, Global Data: 5662--------------------------- 5663 5664The implementation of U-Boot is complicated by the fact that U-Boot 5665starts running out of ROM (flash memory), usually without access to 5666system RAM (because the memory controller is not initialized yet). 5667This means that we don't have writable Data or BSS segments, and BSS 5668is not initialized as zero. To be able to get a C environment working 5669at all, we have to allocate at least a minimal stack. Implementation 5670options for this are defined and restricted by the CPU used: Some CPU 5671models provide on-chip memory (like the IMMR area on MPC8xx and 5672MPC826x processors), on others (parts of) the data cache can be 5673locked as (mis-) used as memory, etc. 5674 5675 Chris Hallinan posted a good summary of these issues to the 5676 U-Boot mailing list: 5677 5678 Subject: RE: [U-Boot-Users] RE: More On Memory Bank x (nothingness)? 5679 From: "Chris Hallinan" <clh@net1plus.com> 5680 Date: Mon, 10 Feb 2003 16:43:46 -0500 (22:43 MET) 5681 ... 5682 5683 Correct me if I'm wrong, folks, but the way I understand it 5684 is this: Using DCACHE as initial RAM for Stack, etc, does not 5685 require any physical RAM backing up the cache. The cleverness 5686 is that the cache is being used as a temporary supply of 5687 necessary storage before the SDRAM controller is setup. It's 5688 beyond the scope of this list to explain the details, but you 5689 can see how this works by studying the cache architecture and 5690 operation in the architecture and processor-specific manuals. 5691 5692 OCM is On Chip Memory, which I believe the 405GP has 4K. It 5693 is another option for the system designer to use as an 5694 initial stack/RAM area prior to SDRAM being available. Either 5695 option should work for you. Using CS 4 should be fine if your 5696 board designers haven't used it for something that would 5697 cause you grief during the initial boot! It is frequently not 5698 used. 5699 5700 CONFIG_SYS_INIT_RAM_ADDR should be somewhere that won't interfere 5701 with your processor/board/system design. The default value 5702 you will find in any recent u-boot distribution in 5703 walnut.h should work for you. I'd set it to a value larger 5704 than your SDRAM module. If you have a 64MB SDRAM module, set 5705 it above 400_0000. Just make sure your board has no resources 5706 that are supposed to respond to that address! That code in 5707 start.S has been around a while and should work as is when 5708 you get the config right. 5709 5710 -Chris Hallinan 5711 DS4.COM, Inc. 5712 5713It is essential to remember this, since it has some impact on the C 5714code for the initialization procedures: 5715 5716* Initialized global data (data segment) is read-only. Do not attempt 5717 to write it. 5718 5719* Do not use any uninitialized global data (or implicitly initialized 5720 as zero data - BSS segment) at all - this is undefined, initiali- 5721 zation is performed later (when relocating to RAM). 5722 5723* Stack space is very limited. Avoid big data buffers or things like 5724 that. 5725 5726Having only the stack as writable memory limits means we cannot use 5727normal global data to share information between the code. But it 5728turned out that the implementation of U-Boot can be greatly 5729simplified by making a global data structure (gd_t) available to all 5730functions. We could pass a pointer to this data as argument to _all_ 5731functions, but this would bloat the code. Instead we use a feature of 5732the GCC compiler (Global Register Variables) to share the data: we 5733place a pointer (gd) to the global data into a register which we 5734reserve for this purpose. 5735 5736When choosing a register for such a purpose we are restricted by the 5737relevant (E)ABI specifications for the current architecture, and by 5738GCC's implementation. 5739 5740For PowerPC, the following registers have specific use: 5741 R1: stack pointer 5742 R2: reserved for system use 5743 R3-R4: parameter passing and return values 5744 R5-R10: parameter passing 5745 R13: small data area pointer 5746 R30: GOT pointer 5747 R31: frame pointer 5748 5749 (U-Boot also uses R12 as internal GOT pointer. r12 5750 is a volatile register so r12 needs to be reset when 5751 going back and forth between asm and C) 5752 5753 ==> U-Boot will use R2 to hold a pointer to the global data 5754 5755 Note: on PPC, we could use a static initializer (since the 5756 address of the global data structure is known at compile time), 5757 but it turned out that reserving a register results in somewhat 5758 smaller code - although the code savings are not that big (on 5759 average for all boards 752 bytes for the whole U-Boot image, 5760 624 text + 127 data). 5761 5762On ARM, the following registers are used: 5763 5764 R0: function argument word/integer result 5765 R1-R3: function argument word 5766 R9: platform specific 5767 R10: stack limit (used only if stack checking is enabled) 5768 R11: argument (frame) pointer 5769 R12: temporary workspace 5770 R13: stack pointer 5771 R14: link register 5772 R15: program counter 5773 5774 ==> U-Boot will use R9 to hold a pointer to the global data 5775 5776 Note: on ARM, only R_ARM_RELATIVE relocations are supported. 5777 5778On Nios II, the ABI is documented here: 5779 http://www.altera.com/literature/hb/nios2/n2cpu_nii51016.pdf 5780 5781 ==> U-Boot will use gp to hold a pointer to the global data 5782 5783 Note: on Nios II, we give "-G0" option to gcc and don't use gp 5784 to access small data sections, so gp is free. 5785 5786On NDS32, the following registers are used: 5787 5788 R0-R1: argument/return 5789 R2-R5: argument 5790 R15: temporary register for assembler 5791 R16: trampoline register 5792 R28: frame pointer (FP) 5793 R29: global pointer (GP) 5794 R30: link register (LP) 5795 R31: stack pointer (SP) 5796 PC: program counter (PC) 5797 5798 ==> U-Boot will use R10 to hold a pointer to the global data 5799 5800NOTE: DECLARE_GLOBAL_DATA_PTR must be used with file-global scope, 5801or current versions of GCC may "optimize" the code too much. 5802 5803Memory Management: 5804------------------ 5805 5806U-Boot runs in system state and uses physical addresses, i.e. the 5807MMU is not used either for address mapping nor for memory protection. 5808 5809The available memory is mapped to fixed addresses using the memory 5810controller. In this process, a contiguous block is formed for each 5811memory type (Flash, SDRAM, SRAM), even when it consists of several 5812physical memory banks. 5813 5814U-Boot is installed in the first 128 kB of the first Flash bank (on 5815TQM8xxL modules this is the range 0x40000000 ... 0x4001FFFF). After 5816booting and sizing and initializing DRAM, the code relocates itself 5817to the upper end of DRAM. Immediately below the U-Boot code some 5818memory is reserved for use by malloc() [see CONFIG_SYS_MALLOC_LEN 5819configuration setting]. Below that, a structure with global Board 5820Info data is placed, followed by the stack (growing downward). 5821 5822Additionally, some exception handler code is copied to the low 8 kB 5823of DRAM (0x00000000 ... 0x00001FFF). 5824 5825So a typical memory configuration with 16 MB of DRAM could look like 5826this: 5827 5828 0x0000 0000 Exception Vector code 5829 : 5830 0x0000 1FFF 5831 0x0000 2000 Free for Application Use 5832 : 5833 : 5834 5835 : 5836 : 5837 0x00FB FF20 Monitor Stack (Growing downward) 5838 0x00FB FFAC Board Info Data and permanent copy of global data 5839 0x00FC 0000 Malloc Arena 5840 : 5841 0x00FD FFFF 5842 0x00FE 0000 RAM Copy of Monitor Code 5843 ... eventually: LCD or video framebuffer 5844 ... eventually: pRAM (Protected RAM - unchanged by reset) 5845 0x00FF FFFF [End of RAM] 5846 5847 5848System Initialization: 5849---------------------- 5850 5851In the reset configuration, U-Boot starts at the reset entry point 5852(on most PowerPC systems at address 0x00000100). Because of the reset 5853configuration for CS0# this is a mirror of the on board Flash memory. 5854To be able to re-map memory U-Boot then jumps to its link address. 5855To be able to implement the initialization code in C, a (small!) 5856initial stack is set up in the internal Dual Ported RAM (in case CPUs 5857which provide such a feature like MPC8xx or MPC8260), or in a locked 5858part of the data cache. After that, U-Boot initializes the CPU core, 5859the caches and the SIU. 5860 5861Next, all (potentially) available memory banks are mapped using a 5862preliminary mapping. For example, we put them on 512 MB boundaries 5863(multiples of 0x20000000: SDRAM on 0x00000000 and 0x20000000, Flash 5864on 0x40000000 and 0x60000000, SRAM on 0x80000000). Then UPM A is 5865programmed for SDRAM access. Using the temporary configuration, a 5866simple memory test is run that determines the size of the SDRAM 5867banks. 5868 5869When there is more than one SDRAM bank, and the banks are of 5870different size, the largest is mapped first. For equal size, the first 5871bank (CS2#) is mapped first. The first mapping is always for address 58720x00000000, with any additional banks following immediately to create 5873contiguous memory starting from 0. 5874 5875Then, the monitor installs itself at the upper end of the SDRAM area 5876and allocates memory for use by malloc() and for the global Board 5877Info data; also, the exception vector code is copied to the low RAM 5878pages, and the final stack is set up. 5879 5880Only after this relocation will you have a "normal" C environment; 5881until that you are restricted in several ways, mostly because you are 5882running from ROM, and because the code will have to be relocated to a 5883new address in RAM. 5884 5885 5886U-Boot Porting Guide: 5887---------------------- 5888 5889[Based on messages by Jerry Van Baren in the U-Boot-Users mailing 5890list, October 2002] 5891 5892 5893int main(int argc, char *argv[]) 5894{ 5895 sighandler_t no_more_time; 5896 5897 signal(SIGALRM, no_more_time); 5898 alarm(PROJECT_DEADLINE - toSec (3 * WEEK)); 5899 5900 if (available_money > available_manpower) { 5901 Pay consultant to port U-Boot; 5902 return 0; 5903 } 5904 5905 Download latest U-Boot source; 5906 5907 Subscribe to u-boot mailing list; 5908 5909 if (clueless) 5910 email("Hi, I am new to U-Boot, how do I get started?"); 5911 5912 while (learning) { 5913 Read the README file in the top level directory; 5914 Read http://www.denx.de/twiki/bin/view/DULG/Manual; 5915 Read applicable doc/*.README; 5916 Read the source, Luke; 5917 /* find . -name "*.[chS]" | xargs grep -i <keyword> */ 5918 } 5919 5920 if (available_money > toLocalCurrency ($2500)) 5921 Buy a BDI3000; 5922 else 5923 Add a lot of aggravation and time; 5924 5925 if (a similar board exists) { /* hopefully... */ 5926 cp -a board/<similar> board/<myboard> 5927 cp include/configs/<similar>.h include/configs/<myboard>.h 5928 } else { 5929 Create your own board support subdirectory; 5930 Create your own board include/configs/<myboard>.h file; 5931 } 5932 Edit new board/<myboard> files 5933 Edit new include/configs/<myboard>.h 5934 5935 while (!accepted) { 5936 while (!running) { 5937 do { 5938 Add / modify source code; 5939 } until (compiles); 5940 Debug; 5941 if (clueless) 5942 email("Hi, I am having problems..."); 5943 } 5944 Send patch file to the U-Boot email list; 5945 if (reasonable critiques) 5946 Incorporate improvements from email list code review; 5947 else 5948 Defend code as written; 5949 } 5950 5951 return 0; 5952} 5953 5954void no_more_time (int sig) 5955{ 5956 hire_a_guru(); 5957} 5958 5959 5960Coding Standards: 5961----------------- 5962 5963All contributions to U-Boot should conform to the Linux kernel 5964coding style; see the file "Documentation/CodingStyle" and the script 5965"scripts/Lindent" in your Linux kernel source directory. 5966 5967Source files originating from a different project (for example the 5968MTD subsystem) are generally exempt from these guidelines and are not 5969reformatted to ease subsequent migration to newer versions of those 5970sources. 5971 5972Please note that U-Boot is implemented in C (and to some small parts in 5973Assembler); no C++ is used, so please do not use C++ style comments (//) 5974in your code. 5975 5976Please also stick to the following formatting rules: 5977- remove any trailing white space 5978- use TAB characters for indentation and vertical alignment, not spaces 5979- make sure NOT to use DOS '\r\n' line feeds 5980- do not add more than 2 consecutive empty lines to source files 5981- do not add trailing empty lines to source files 5982 5983Submissions which do not conform to the standards may be returned 5984with a request to reformat the changes. 5985 5986 5987Submitting Patches: 5988------------------- 5989 5990Since the number of patches for U-Boot is growing, we need to 5991establish some rules. Submissions which do not conform to these rules 5992may be rejected, even when they contain important and valuable stuff. 5993 5994Please see http://www.denx.de/wiki/U-Boot/Patches for details. 5995 5996Patches shall be sent to the u-boot mailing list <u-boot@lists.denx.de>; 5997see http://lists.denx.de/mailman/listinfo/u-boot 5998 5999When you send a patch, please include the following information with 6000it: 6001 6002* For bug fixes: a description of the bug and how your patch fixes 6003 this bug. Please try to include a way of demonstrating that the 6004 patch actually fixes something. 6005 6006* For new features: a description of the feature and your 6007 implementation. 6008 6009* A CHANGELOG entry as plaintext (separate from the patch) 6010 6011* For major contributions, add a MAINTAINERS file with your 6012 information and associated file and directory references. 6013 6014* When you add support for a new board, don't forget to add a 6015 maintainer e-mail address to the boards.cfg file, too. 6016 6017* If your patch adds new configuration options, don't forget to 6018 document these in the README file. 6019 6020* The patch itself. If you are using git (which is *strongly* 6021 recommended) you can easily generate the patch using the 6022 "git format-patch". If you then use "git send-email" to send it to 6023 the U-Boot mailing list, you will avoid most of the common problems 6024 with some other mail clients. 6025 6026 If you cannot use git, use "diff -purN OLD NEW". If your version of 6027 diff does not support these options, then get the latest version of 6028 GNU diff. 6029 6030 The current directory when running this command shall be the parent 6031 directory of the U-Boot source tree (i. e. please make sure that 6032 your patch includes sufficient directory information for the 6033 affected files). 6034 6035 We prefer patches as plain text. MIME attachments are discouraged, 6036 and compressed attachments must not be used. 6037 6038* If one logical set of modifications affects or creates several 6039 files, all these changes shall be submitted in a SINGLE patch file. 6040 6041* Changesets that contain different, unrelated modifications shall be 6042 submitted as SEPARATE patches, one patch per changeset. 6043 6044 6045Notes: 6046 6047* Before sending the patch, run the buildman script on your patched 6048 source tree and make sure that no errors or warnings are reported 6049 for any of the boards. 6050 6051* Keep your modifications to the necessary minimum: A patch 6052 containing several unrelated changes or arbitrary reformats will be 6053 returned with a request to re-formatting / split it. 6054 6055* If you modify existing code, make sure that your new code does not 6056 add to the memory footprint of the code ;-) Small is beautiful! 6057 When adding new features, these should compile conditionally only 6058 (using #ifdef), and the resulting code with the new feature 6059 disabled must not need more memory than the old code without your 6060 modification. 6061 6062* Remember that there is a size limit of 100 kB per message on the 6063 u-boot mailing list. Bigger patches will be moderated. If they are 6064 reasonable and not too big, they will be acknowledged. But patches 6065 bigger than the size limit should be avoided. 6066