1# 2# (C) Copyright 2000 - 2013 3# Wolfgang Denk, DENX Software Engineering, wd@denx.de. 4# 5# SPDX-License-Identifier: GPL-2.0+ 6# 7 8Summary: 9======== 10 11This directory contains the source code for U-Boot, a boot loader for 12Embedded boards based on PowerPC, ARM, MIPS and several other 13processors, which can be installed in a boot ROM and used to 14initialize and test the hardware or to download and run application 15code. 16 17The development of U-Boot is closely related to Linux: some parts of 18the source code originate in the Linux source tree, we have some 19header files in common, and special provision has been made to 20support booting of Linux images. 21 22Some attention has been paid to make this software easily 23configurable and extendable. For instance, all monitor commands are 24implemented with the same call interface, so that it's very easy to 25add new commands. Also, instead of permanently adding rarely used 26code (for instance hardware test utilities) to the monitor, you can 27load and run it dynamically. 28 29 30Status: 31======= 32 33In general, all boards for which a configuration option exists in the 34Makefile have been tested to some extent and can be considered 35"working". In fact, many of them are used in production systems. 36 37In case of problems see the CHANGELOG file to find out who contributed 38the specific port. In addition, there are various MAINTAINERS files 39scattered throughout the U-Boot source identifying the people or 40companies responsible for various boards and subsystems. 41 42Note: As of August, 2010, there is no longer a CHANGELOG file in the 43actual U-Boot source tree; however, it can be created dynamically 44from the Git log using: 45 46 make CHANGELOG 47 48 49Where to get help: 50================== 51 52In case you have questions about, problems with or contributions for 53U-Boot, you should send a message to the U-Boot mailing list at 54<u-boot@lists.denx.de>. There is also an archive of previous traffic 55on the mailing list - please search the archive before asking FAQ's. 56Please see http://lists.denx.de/pipermail/u-boot and 57http://dir.gmane.org/gmane.comp.boot-loaders.u-boot 58 59 60Where to get source code: 61========================= 62 63The U-Boot source code is maintained in the Git repository at 64git://www.denx.de/git/u-boot.git ; you can browse it online at 65http://www.denx.de/cgi-bin/gitweb.cgi?p=u-boot.git;a=summary 66 67The "snapshot" links on this page allow you to download tarballs of 68any version you might be interested in. Official releases are also 69available for FTP download from the ftp://ftp.denx.de/pub/u-boot/ 70directory. 71 72Pre-built (and tested) images are available from 73ftp://ftp.denx.de/pub/u-boot/images/ 74 75 76Where we come from: 77=================== 78 79- start from 8xxrom sources 80- create PPCBoot project (http://sourceforge.net/projects/ppcboot) 81- clean up code 82- make it easier to add custom boards 83- make it possible to add other [PowerPC] CPUs 84- extend functions, especially: 85 * Provide extended interface to Linux boot loader 86 * S-Record download 87 * network boot 88 * PCMCIA / CompactFlash / ATA disk / SCSI ... boot 89- create ARMBoot project (http://sourceforge.net/projects/armboot) 90- add other CPU families (starting with ARM) 91- create U-Boot project (http://sourceforge.net/projects/u-boot) 92- current project page: see http://www.denx.de/wiki/U-Boot 93 94 95Names and Spelling: 96=================== 97 98The "official" name of this project is "Das U-Boot". The spelling 99"U-Boot" shall be used in all written text (documentation, comments 100in source files etc.). Example: 101 102 This is the README file for the U-Boot project. 103 104File names etc. shall be based on the string "u-boot". Examples: 105 106 include/asm-ppc/u-boot.h 107 108 #include <asm/u-boot.h> 109 110Variable names, preprocessor constants etc. shall be either based on 111the string "u_boot" or on "U_BOOT". Example: 112 113 U_BOOT_VERSION u_boot_logo 114 IH_OS_U_BOOT u_boot_hush_start 115 116 117Versioning: 118=========== 119 120Starting with the release in October 2008, the names of the releases 121were changed from numerical release numbers without deeper meaning 122into a time stamp based numbering. Regular releases are identified by 123names consisting of the calendar year and month of the release date. 124Additional fields (if present) indicate release candidates or bug fix 125releases in "stable" maintenance trees. 126 127Examples: 128 U-Boot v2009.11 - Release November 2009 129 U-Boot v2009.11.1 - Release 1 in version November 2009 stable tree 130 U-Boot v2010.09-rc1 - Release candidate 1 for September 2010 release 131 132 133Directory Hierarchy: 134==================== 135 136/arch Architecture specific files 137 /arc Files generic to ARC architecture 138 /arm Files generic to ARM architecture 139 /avr32 Files generic to AVR32 architecture 140 /m68k Files generic to m68k architecture 141 /microblaze Files generic to microblaze architecture 142 /mips Files generic to MIPS architecture 143 /nds32 Files generic to NDS32 architecture 144 /nios2 Files generic to Altera NIOS2 architecture 145 /openrisc Files generic to OpenRISC architecture 146 /powerpc Files generic to PowerPC architecture 147 /sandbox Files generic to HW-independent "sandbox" 148 /sh Files generic to SH architecture 149 /x86 Files generic to x86 architecture 150/api Machine/arch independent API for external apps 151/board Board dependent files 152/cmd U-Boot commands functions 153/common Misc architecture independent functions 154/configs Board default configuration files 155/disk Code for disk drive partition handling 156/doc Documentation (don't expect too much) 157/drivers Commonly used device drivers 158/dts Contains Makefile for building internal U-Boot fdt. 159/examples Example code for standalone applications, etc. 160/fs Filesystem code (cramfs, ext2, jffs2, etc.) 161/include Header Files 162/lib Library routines generic to all architectures 163/Licenses Various license files 164/net Networking code 165/post Power On Self Test 166/scripts Various build scripts and Makefiles 167/test Various unit test files 168/tools Tools to build S-Record or U-Boot images, etc. 169 170Software Configuration: 171======================= 172 173Configuration is usually done using C preprocessor defines; the 174rationale behind that is to avoid dead code whenever possible. 175 176There are two classes of configuration variables: 177 178* Configuration _OPTIONS_: 179 These are selectable by the user and have names beginning with 180 "CONFIG_". 181 182* Configuration _SETTINGS_: 183 These depend on the hardware etc. and should not be meddled with if 184 you don't know what you're doing; they have names beginning with 185 "CONFIG_SYS_". 186 187Previously, all configuration was done by hand, which involved creating 188symbolic links and editing configuration files manually. More recently, 189U-Boot has added the Kbuild infrastructure used by the Linux kernel, 190allowing you to use the "make menuconfig" command to configure your 191build. 192 193 194Selection of Processor Architecture and Board Type: 195--------------------------------------------------- 196 197For all supported boards there are ready-to-use default 198configurations available; just type "make <board_name>_defconfig". 199 200Example: For a TQM823L module type: 201 202 cd u-boot 203 make TQM823L_defconfig 204 205Note: If you're looking for the default configuration file for a board 206you're sure used to be there but is now missing, check the file 207doc/README.scrapyard for a list of no longer supported boards. 208 209Sandbox Environment: 210-------------------- 211 212U-Boot can be built natively to run on a Linux host using the 'sandbox' 213board. This allows feature development which is not board- or architecture- 214specific to be undertaken on a native platform. The sandbox is also used to 215run some of U-Boot's tests. 216 217See board/sandbox/README.sandbox for more details. 218 219 220Board Initialisation Flow: 221-------------------------- 222 223This is the intended start-up flow for boards. This should apply for both 224SPL and U-Boot proper (i.e. they both follow the same rules). 225 226Note: "SPL" stands for "Secondary Program Loader," which is explained in 227more detail later in this file. 228 229At present, SPL mostly uses a separate code path, but the function names 230and roles of each function are the same. Some boards or architectures 231may not conform to this. At least most ARM boards which use 232CONFIG_SPL_FRAMEWORK conform to this. 233 234Execution typically starts with an architecture-specific (and possibly 235CPU-specific) start.S file, such as: 236 237 - arch/arm/cpu/armv7/start.S 238 - arch/powerpc/cpu/mpc83xx/start.S 239 - arch/mips/cpu/start.S 240 241and so on. From there, three functions are called; the purpose and 242limitations of each of these functions are described below. 243 244lowlevel_init(): 245 - purpose: essential init to permit execution to reach board_init_f() 246 - no global_data or BSS 247 - there is no stack (ARMv7 may have one but it will soon be removed) 248 - must not set up SDRAM or use console 249 - must only do the bare minimum to allow execution to continue to 250 board_init_f() 251 - this is almost never needed 252 - return normally from this function 253 254board_init_f(): 255 - purpose: set up the machine ready for running board_init_r(): 256 i.e. SDRAM and serial UART 257 - global_data is available 258 - stack is in SRAM 259 - BSS is not available, so you cannot use global/static variables, 260 only stack variables and global_data 261 262 Non-SPL-specific notes: 263 - dram_init() is called to set up DRAM. If already done in SPL this 264 can do nothing 265 266 SPL-specific notes: 267 - you can override the entire board_init_f() function with your own 268 version as needed. 269 - preloader_console_init() can be called here in extremis 270 - should set up SDRAM, and anything needed to make the UART work 271 - these is no need to clear BSS, it will be done by crt0.S 272 - must return normally from this function (don't call board_init_r() 273 directly) 274 275Here the BSS is cleared. For SPL, if CONFIG_SPL_STACK_R is defined, then at 276this point the stack and global_data are relocated to below 277CONFIG_SPL_STACK_R_ADDR. For non-SPL, U-Boot is relocated to run at the top of 278memory. 279 280board_init_r(): 281 - purpose: main execution, common code 282 - global_data is available 283 - SDRAM is available 284 - BSS is available, all static/global variables can be used 285 - execution eventually continues to main_loop() 286 287 Non-SPL-specific notes: 288 - U-Boot is relocated to the top of memory and is now running from 289 there. 290 291 SPL-specific notes: 292 - stack is optionally in SDRAM, if CONFIG_SPL_STACK_R is defined and 293 CONFIG_SPL_STACK_R_ADDR points into SDRAM 294 - preloader_console_init() can be called here - typically this is 295 done by selecting CONFIG_SPL_BOARD_INIT and then supplying a 296 spl_board_init() function containing this call 297 - loads U-Boot or (in falcon mode) Linux 298 299 300 301Configuration Options: 302---------------------- 303 304Configuration depends on the combination of board and CPU type; all 305such information is kept in a configuration file 306"include/configs/<board_name>.h". 307 308Example: For a TQM823L module, all configuration settings are in 309"include/configs/TQM823L.h". 310 311 312Many of the options are named exactly as the corresponding Linux 313kernel configuration options. The intention is to make it easier to 314build a config tool - later. 315 316 317The following options need to be configured: 318 319- CPU Type: Define exactly one, e.g. CONFIG_MPC85XX. 320 321- Board Type: Define exactly one, e.g. CONFIG_MPC8540ADS. 322 323- CPU Daughterboard Type: (if CONFIG_ATSTK1000 is defined) 324 Define exactly one, e.g. CONFIG_ATSTK1002 325 326- Marvell Family Member 327 CONFIG_SYS_MVFS - define it if you want to enable 328 multiple fs option at one time 329 for marvell soc family 330 331- 8xx CPU Options: (if using an MPC8xx CPU) 332 CONFIG_8xx_GCLK_FREQ - deprecated: CPU clock if 333 get_gclk_freq() cannot work 334 e.g. if there is no 32KHz 335 reference PIT/RTC clock 336 CONFIG_8xx_OSCLK - PLL input clock (either EXTCLK 337 or XTAL/EXTAL) 338 339- 859/866/885 CPU options: (if using a MPC859 or MPC866 or MPC885 CPU): 340 CONFIG_SYS_8xx_CPUCLK_MIN 341 CONFIG_SYS_8xx_CPUCLK_MAX 342 CONFIG_8xx_CPUCLK_DEFAULT 343 See doc/README.MPC866 344 345 CONFIG_SYS_MEASURE_CPUCLK 346 347 Define this to measure the actual CPU clock instead 348 of relying on the correctness of the configured 349 values. Mostly useful for board bringup to make sure 350 the PLL is locked at the intended frequency. Note 351 that this requires a (stable) reference clock (32 kHz 352 RTC clock or CONFIG_SYS_8XX_XIN) 353 354 CONFIG_SYS_DELAYED_ICACHE 355 356 Define this option if you want to enable the 357 ICache only when Code runs from RAM. 358 359- 85xx CPU Options: 360 CONFIG_SYS_PPC64 361 362 Specifies that the core is a 64-bit PowerPC implementation (implements 363 the "64" category of the Power ISA). This is necessary for ePAPR 364 compliance, among other possible reasons. 365 366 CONFIG_SYS_FSL_TBCLK_DIV 367 368 Defines the core time base clock divider ratio compared to the 369 system clock. On most PQ3 devices this is 8, on newer QorIQ 370 devices it can be 16 or 32. The ratio varies from SoC to Soc. 371 372 CONFIG_SYS_FSL_PCIE_COMPAT 373 374 Defines the string to utilize when trying to match PCIe device 375 tree nodes for the given platform. 376 377 CONFIG_SYS_FSL_ERRATUM_A004510 378 379 Enables a workaround for erratum A004510. If set, 380 then CONFIG_SYS_FSL_ERRATUM_A004510_SVR_REV and 381 CONFIG_SYS_FSL_CORENET_SNOOPVEC_COREONLY must be set. 382 383 CONFIG_SYS_FSL_ERRATUM_A004510_SVR_REV 384 CONFIG_SYS_FSL_ERRATUM_A004510_SVR_REV2 (optional) 385 386 Defines one or two SoC revisions (low 8 bits of SVR) 387 for which the A004510 workaround should be applied. 388 389 The rest of SVR is either not relevant to the decision 390 of whether the erratum is present (e.g. p2040 versus 391 p2041) or is implied by the build target, which controls 392 whether CONFIG_SYS_FSL_ERRATUM_A004510 is set. 393 394 See Freescale App Note 4493 for more information about 395 this erratum. 396 397 CONFIG_A003399_NOR_WORKAROUND 398 Enables a workaround for IFC erratum A003399. It is only 399 required during NOR boot. 400 401 CONFIG_A008044_WORKAROUND 402 Enables a workaround for T1040/T1042 erratum A008044. It is only 403 required during NAND boot and valid for Rev 1.0 SoC revision 404 405 CONFIG_SYS_FSL_CORENET_SNOOPVEC_COREONLY 406 407 This is the value to write into CCSR offset 0x18600 408 according to the A004510 workaround. 409 410 CONFIG_SYS_FSL_DSP_DDR_ADDR 411 This value denotes start offset of DDR memory which is 412 connected exclusively to the DSP cores. 413 414 CONFIG_SYS_FSL_DSP_M2_RAM_ADDR 415 This value denotes start offset of M2 memory 416 which is directly connected to the DSP core. 417 418 CONFIG_SYS_FSL_DSP_M3_RAM_ADDR 419 This value denotes start offset of M3 memory which is directly 420 connected to the DSP core. 421 422 CONFIG_SYS_FSL_DSP_CCSRBAR_DEFAULT 423 This value denotes start offset of DSP CCSR space. 424 425 CONFIG_SYS_FSL_SINGLE_SOURCE_CLK 426 Single Source Clock is clocking mode present in some of FSL SoC's. 427 In this mode, a single differential clock is used to supply 428 clocks to the sysclock, ddrclock and usbclock. 429 430 CONFIG_SYS_CPC_REINIT_F 431 This CONFIG is defined when the CPC is configured as SRAM at the 432 time of U-Boot entry and is required to be re-initialized. 433 434 CONFIG_DEEP_SLEEP 435 Indicates this SoC supports deep sleep feature. If deep sleep is 436 supported, core will start to execute uboot when wakes up. 437 438- Generic CPU options: 439 CONFIG_SYS_GENERIC_GLOBAL_DATA 440 Defines global data is initialized in generic board board_init_f(). 441 If this macro is defined, global data is created and cleared in 442 generic board board_init_f(). Without this macro, architecture/board 443 should initialize global data before calling board_init_f(). 444 445 CONFIG_SYS_BIG_ENDIAN, CONFIG_SYS_LITTLE_ENDIAN 446 447 Defines the endianess of the CPU. Implementation of those 448 values is arch specific. 449 450 CONFIG_SYS_FSL_DDR 451 Freescale DDR driver in use. This type of DDR controller is 452 found in mpc83xx, mpc85xx, mpc86xx as well as some ARM core 453 SoCs. 454 455 CONFIG_SYS_FSL_DDR_ADDR 456 Freescale DDR memory-mapped register base. 457 458 CONFIG_SYS_FSL_DDR_EMU 459 Specify emulator support for DDR. Some DDR features such as 460 deskew training are not available. 461 462 CONFIG_SYS_FSL_DDRC_GEN1 463 Freescale DDR1 controller. 464 465 CONFIG_SYS_FSL_DDRC_GEN2 466 Freescale DDR2 controller. 467 468 CONFIG_SYS_FSL_DDRC_GEN3 469 Freescale DDR3 controller. 470 471 CONFIG_SYS_FSL_DDRC_GEN4 472 Freescale DDR4 controller. 473 474 CONFIG_SYS_FSL_DDRC_ARM_GEN3 475 Freescale DDR3 controller for ARM-based SoCs. 476 477 CONFIG_SYS_FSL_DDR1 478 Board config to use DDR1. It can be enabled for SoCs with 479 Freescale DDR1 or DDR2 controllers, depending on the board 480 implemetation. 481 482 CONFIG_SYS_FSL_DDR2 483 Board config to use DDR2. It can be enabled for SoCs with 484 Freescale DDR2 or DDR3 controllers, depending on the board 485 implementation. 486 487 CONFIG_SYS_FSL_DDR3 488 Board config to use DDR3. It can be enabled for SoCs with 489 Freescale DDR3 or DDR3L controllers. 490 491 CONFIG_SYS_FSL_DDR3L 492 Board config to use DDR3L. It can be enabled for SoCs with 493 DDR3L controllers. 494 495 CONFIG_SYS_FSL_DDR4 496 Board config to use DDR4. It can be enabled for SoCs with 497 DDR4 controllers. 498 499 CONFIG_SYS_FSL_IFC_BE 500 Defines the IFC controller register space as Big Endian 501 502 CONFIG_SYS_FSL_IFC_LE 503 Defines the IFC controller register space as Little Endian 504 505 CONFIG_SYS_FSL_IFC_CLK_DIV 506 Defines divider of platform clock(clock input to IFC controller). 507 508 CONFIG_SYS_FSL_LBC_CLK_DIV 509 Defines divider of platform clock(clock input to eLBC controller). 510 511 CONFIG_SYS_FSL_PBL_PBI 512 It enables addition of RCW (Power on reset configuration) in built image. 513 Please refer doc/README.pblimage for more details 514 515 CONFIG_SYS_FSL_PBL_RCW 516 It adds PBI(pre-boot instructions) commands in u-boot build image. 517 PBI commands can be used to configure SoC before it starts the execution. 518 Please refer doc/README.pblimage for more details 519 520 CONFIG_SPL_FSL_PBL 521 It adds a target to create boot binary having SPL binary in PBI format 522 concatenated with u-boot binary. 523 524 CONFIG_SYS_FSL_DDR_BE 525 Defines the DDR controller register space as Big Endian 526 527 CONFIG_SYS_FSL_DDR_LE 528 Defines the DDR controller register space as Little Endian 529 530 CONFIG_SYS_FSL_DDR_SDRAM_BASE_PHY 531 Physical address from the view of DDR controllers. It is the 532 same as CONFIG_SYS_DDR_SDRAM_BASE for all Power SoCs. But 533 it could be different for ARM SoCs. 534 535 CONFIG_SYS_FSL_DDR_INTLV_256B 536 DDR controller interleaving on 256-byte. This is a special 537 interleaving mode, handled by Dickens for Freescale layerscape 538 SoCs with ARM core. 539 540 CONFIG_SYS_FSL_DDR_MAIN_NUM_CTRLS 541 Number of controllers used as main memory. 542 543 CONFIG_SYS_FSL_OTHER_DDR_NUM_CTRLS 544 Number of controllers used for other than main memory. 545 546 CONFIG_SYS_FSL_HAS_DP_DDR 547 Defines the SoC has DP-DDR used for DPAA. 548 549 CONFIG_SYS_FSL_SEC_BE 550 Defines the SEC controller register space as Big Endian 551 552 CONFIG_SYS_FSL_SEC_LE 553 Defines the SEC controller register space as Little Endian 554 555- MIPS CPU options: 556 CONFIG_SYS_INIT_SP_OFFSET 557 558 Offset relative to CONFIG_SYS_SDRAM_BASE for initial stack 559 pointer. This is needed for the temporary stack before 560 relocation. 561 562 CONFIG_SYS_MIPS_CACHE_MODE 563 564 Cache operation mode for the MIPS CPU. 565 See also arch/mips/include/asm/mipsregs.h. 566 Possible values are: 567 CONF_CM_CACHABLE_NO_WA 568 CONF_CM_CACHABLE_WA 569 CONF_CM_UNCACHED 570 CONF_CM_CACHABLE_NONCOHERENT 571 CONF_CM_CACHABLE_CE 572 CONF_CM_CACHABLE_COW 573 CONF_CM_CACHABLE_CUW 574 CONF_CM_CACHABLE_ACCELERATED 575 576 CONFIG_SYS_XWAY_EBU_BOOTCFG 577 578 Special option for Lantiq XWAY SoCs for booting from NOR flash. 579 See also arch/mips/cpu/mips32/start.S. 580 581 CONFIG_XWAY_SWAP_BYTES 582 583 Enable compilation of tools/xway-swap-bytes needed for Lantiq 584 XWAY SoCs for booting from NOR flash. The U-Boot image needs to 585 be swapped if a flash programmer is used. 586 587- ARM options: 588 CONFIG_SYS_EXCEPTION_VECTORS_HIGH 589 590 Select high exception vectors of the ARM core, e.g., do not 591 clear the V bit of the c1 register of CP15. 592 593 COUNTER_FREQUENCY 594 Generic timer clock source frequency. 595 596 COUNTER_FREQUENCY_REAL 597 Generic timer clock source frequency if the real clock is 598 different from COUNTER_FREQUENCY, and can only be determined 599 at run time. 600 601- Tegra SoC options: 602 CONFIG_TEGRA_SUPPORT_NON_SECURE 603 604 Support executing U-Boot in non-secure (NS) mode. Certain 605 impossible actions will be skipped if the CPU is in NS mode, 606 such as ARM architectural timer initialization. 607 608- Linux Kernel Interface: 609 CONFIG_CLOCKS_IN_MHZ 610 611 U-Boot stores all clock information in Hz 612 internally. For binary compatibility with older Linux 613 kernels (which expect the clocks passed in the 614 bd_info data to be in MHz) the environment variable 615 "clocks_in_mhz" can be defined so that U-Boot 616 converts clock data to MHZ before passing it to the 617 Linux kernel. 618 When CONFIG_CLOCKS_IN_MHZ is defined, a definition of 619 "clocks_in_mhz=1" is automatically included in the 620 default environment. 621 622 CONFIG_MEMSIZE_IN_BYTES [relevant for MIPS only] 623 624 When transferring memsize parameter to Linux, some versions 625 expect it to be in bytes, others in MB. 626 Define CONFIG_MEMSIZE_IN_BYTES to make it in bytes. 627 628 CONFIG_OF_LIBFDT 629 630 New kernel versions are expecting firmware settings to be 631 passed using flattened device trees (based on open firmware 632 concepts). 633 634 CONFIG_OF_LIBFDT 635 * New libfdt-based support 636 * Adds the "fdt" command 637 * The bootm command automatically updates the fdt 638 639 OF_CPU - The proper name of the cpus node (only required for 640 MPC512X and MPC5xxx based boards). 641 OF_SOC - The proper name of the soc node (only required for 642 MPC512X and MPC5xxx based boards). 643 OF_TBCLK - The timebase frequency. 644 OF_STDOUT_PATH - The path to the console device 645 646 boards with QUICC Engines require OF_QE to set UCC MAC 647 addresses 648 649 CONFIG_OF_BOARD_SETUP 650 651 Board code has addition modification that it wants to make 652 to the flat device tree before handing it off to the kernel 653 654 CONFIG_OF_SYSTEM_SETUP 655 656 Other code has addition modification that it wants to make 657 to the flat device tree before handing it off to the kernel. 658 This causes ft_system_setup() to be called before booting 659 the kernel. 660 661 CONFIG_OF_IDE_FIXUP 662 663 U-Boot can detect if an IDE device is present or not. 664 If not, and this new config option is activated, U-Boot 665 removes the ATA node from the DTS before booting Linux, 666 so the Linux IDE driver does not probe the device and 667 crash. This is needed for buggy hardware (uc101) where 668 no pull down resistor is connected to the signal IDE5V_DD7. 669 670 CONFIG_MACH_TYPE [relevant for ARM only][mandatory] 671 672 This setting is mandatory for all boards that have only one 673 machine type and must be used to specify the machine type 674 number as it appears in the ARM machine registry 675 (see http://www.arm.linux.org.uk/developer/machines/). 676 Only boards that have multiple machine types supported 677 in a single configuration file and the machine type is 678 runtime discoverable, do not have to use this setting. 679 680- vxWorks boot parameters: 681 682 bootvx constructs a valid bootline using the following 683 environments variables: bootdev, bootfile, ipaddr, netmask, 684 serverip, gatewayip, hostname, othbootargs. 685 It loads the vxWorks image pointed bootfile. 686 687 Note: If a "bootargs" environment is defined, it will overwride 688 the defaults discussed just above. 689 690- Cache Configuration: 691 CONFIG_SYS_ICACHE_OFF - Do not enable instruction cache in U-Boot 692 CONFIG_SYS_DCACHE_OFF - Do not enable data cache in U-Boot 693 CONFIG_SYS_L2CACHE_OFF- Do not enable L2 cache in U-Boot 694 695- Cache Configuration for ARM: 696 CONFIG_SYS_L2_PL310 - Enable support for ARM PL310 L2 cache 697 controller 698 CONFIG_SYS_PL310_BASE - Physical base address of PL310 699 controller register space 700 701- Serial Ports: 702 CONFIG_PL010_SERIAL 703 704 Define this if you want support for Amba PrimeCell PL010 UARTs. 705 706 CONFIG_PL011_SERIAL 707 708 Define this if you want support for Amba PrimeCell PL011 UARTs. 709 710 CONFIG_PL011_CLOCK 711 712 If you have Amba PrimeCell PL011 UARTs, set this variable to 713 the clock speed of the UARTs. 714 715 CONFIG_PL01x_PORTS 716 717 If you have Amba PrimeCell PL010 or PL011 UARTs on your board, 718 define this to a list of base addresses for each (supported) 719 port. See e.g. include/configs/versatile.h 720 721 CONFIG_SERIAL_HW_FLOW_CONTROL 722 723 Define this variable to enable hw flow control in serial driver. 724 Current user of this option is drivers/serial/nsl16550.c driver 725 726- Console Interface: 727 Depending on board, define exactly one serial port 728 (like CONFIG_8xx_CONS_SMC1, CONFIG_8xx_CONS_SMC2, 729 CONFIG_8xx_CONS_SCC1, ...), or switch off the serial 730 console by defining CONFIG_8xx_CONS_NONE 731 732 Note: if CONFIG_8xx_CONS_NONE is defined, the serial 733 port routines must be defined elsewhere 734 (i.e. serial_init(), serial_getc(), ...) 735 736- Console Baudrate: 737 CONFIG_BAUDRATE - in bps 738 Select one of the baudrates listed in 739 CONFIG_SYS_BAUDRATE_TABLE, see below. 740 CONFIG_SYS_BRGCLK_PRESCALE, baudrate prescale 741 742- Console Rx buffer length 743 With CONFIG_SYS_SMC_RXBUFLEN it is possible to define 744 the maximum receive buffer length for the SMC. 745 This option is actual only for 82xx and 8xx possible. 746 If using CONFIG_SYS_SMC_RXBUFLEN also CONFIG_SYS_MAXIDLE 747 must be defined, to setup the maximum idle timeout for 748 the SMC. 749 750- Autoboot Command: 751 CONFIG_BOOTCOMMAND 752 Only needed when CONFIG_BOOTDELAY is enabled; 753 define a command string that is automatically executed 754 when no character is read on the console interface 755 within "Boot Delay" after reset. 756 757 CONFIG_BOOTARGS 758 This can be used to pass arguments to the bootm 759 command. The value of CONFIG_BOOTARGS goes into the 760 environment value "bootargs". 761 762 CONFIG_RAMBOOT and CONFIG_NFSBOOT 763 The value of these goes into the environment as 764 "ramboot" and "nfsboot" respectively, and can be used 765 as a convenience, when switching between booting from 766 RAM and NFS. 767 768- Bootcount: 769 CONFIG_BOOTCOUNT_LIMIT 770 Implements a mechanism for detecting a repeating reboot 771 cycle, see: 772 http://www.denx.de/wiki/view/DULG/UBootBootCountLimit 773 774 CONFIG_BOOTCOUNT_ENV 775 If no softreset save registers are found on the hardware 776 "bootcount" is stored in the environment. To prevent a 777 saveenv on all reboots, the environment variable 778 "upgrade_available" is used. If "upgrade_available" is 779 0, "bootcount" is always 0, if "upgrade_available" is 780 1 "bootcount" is incremented in the environment. 781 So the Userspace Applikation must set the "upgrade_available" 782 and "bootcount" variable to 0, if a boot was successfully. 783 784- Pre-Boot Commands: 785 CONFIG_PREBOOT 786 787 When this option is #defined, the existence of the 788 environment variable "preboot" will be checked 789 immediately before starting the CONFIG_BOOTDELAY 790 countdown and/or running the auto-boot command resp. 791 entering interactive mode. 792 793 This feature is especially useful when "preboot" is 794 automatically generated or modified. For an example 795 see the LWMON board specific code: here "preboot" is 796 modified when the user holds down a certain 797 combination of keys on the (special) keyboard when 798 booting the systems 799 800- Serial Download Echo Mode: 801 CONFIG_LOADS_ECHO 802 If defined to 1, all characters received during a 803 serial download (using the "loads" command) are 804 echoed back. This might be needed by some terminal 805 emulations (like "cu"), but may as well just take 806 time on others. This setting #define's the initial 807 value of the "loads_echo" environment variable. 808 809- Kgdb Serial Baudrate: (if CONFIG_CMD_KGDB is defined) 810 CONFIG_KGDB_BAUDRATE 811 Select one of the baudrates listed in 812 CONFIG_SYS_BAUDRATE_TABLE, see below. 813 814- Monitor Functions: 815 Monitor commands can be included or excluded 816 from the build by using the #include files 817 <config_cmd_all.h> and #undef'ing unwanted 818 commands, or adding #define's for wanted commands. 819 820 The default command configuration includes all commands 821 except those marked below with a "*". 822 823 CONFIG_CMD_AES AES 128 CBC encrypt/decrypt 824 CONFIG_CMD_ASKENV * ask for env variable 825 CONFIG_CMD_BDI bdinfo 826 CONFIG_CMD_BOOTD bootd 827 CONFIG_CMD_BOOTI * ARM64 Linux kernel Image support 828 CONFIG_CMD_CACHE * icache, dcache 829 CONFIG_CMD_CONSOLE coninfo 830 CONFIG_CMD_CRC32 * crc32 831 CONFIG_CMD_DHCP * DHCP support 832 CONFIG_CMD_DIAG * Diagnostics 833 CONFIG_CMD_ECHO echo arguments 834 CONFIG_CMD_EDITENV edit env variable 835 CONFIG_CMD_ELF * bootelf, bootvx 836 CONFIG_CMD_ENV_EXISTS * check existence of env variable 837 CONFIG_CMD_EXPORTENV * export the environment 838 CONFIG_CMD_EXT2 * ext2 command support 839 CONFIG_CMD_EXT4 * ext4 command support 840 CONFIG_CMD_FS_GENERIC * filesystem commands (e.g. load, ls) 841 that work for multiple fs types 842 CONFIG_CMD_FS_UUID * Look up a filesystem UUID 843 CONFIG_CMD_SAVEENV saveenv 844 CONFIG_CMD_FAT * FAT command support 845 CONFIG_CMD_FLASH flinfo, erase, protect 846 CONFIG_CMD_FPGA FPGA device initialization support 847 CONFIG_CMD_GO * the 'go' command (exec code) 848 CONFIG_CMD_GREPENV * search environment 849 CONFIG_CMD_I2C * I2C serial bus support 850 CONFIG_CMD_IDE * IDE harddisk support 851 CONFIG_CMD_IMI iminfo 852 CONFIG_CMD_IMLS List all images found in NOR flash 853 CONFIG_CMD_IMLS_NAND * List all images found in NAND flash 854 CONFIG_CMD_IMMAP * IMMR dump support 855 CONFIG_CMD_IOTRACE * I/O tracing for debugging 856 CONFIG_CMD_IMPORTENV * import an environment 857 CONFIG_CMD_INI * import data from an ini file into the env 858 CONFIG_CMD_IRQ * irqinfo 859 CONFIG_CMD_ITEST Integer/string test of 2 values 860 CONFIG_CMD_JFFS2 * JFFS2 Support 861 CONFIG_CMD_KGDB * kgdb 862 CONFIG_CMD_LDRINFO * ldrinfo (display Blackfin loader) 863 CONFIG_CMD_LINK_LOCAL * link-local IP address auto-configuration 864 (169.254.*.*) 865 CONFIG_CMD_LOADB loadb 866 CONFIG_CMD_LOADS loads 867 CONFIG_CMD_MD5SUM * print md5 message digest 868 (requires CONFIG_CMD_MEMORY and CONFIG_MD5) 869 CONFIG_CMD_MEMINFO * Display detailed memory information 870 CONFIG_CMD_MEMORY md, mm, nm, mw, cp, cmp, crc, base, 871 loop, loopw 872 CONFIG_CMD_MEMTEST * mtest 873 CONFIG_CMD_MISC Misc functions like sleep etc 874 CONFIG_CMD_MMC * MMC memory mapped support 875 CONFIG_CMD_MII * MII utility commands 876 CONFIG_CMD_MTDPARTS * MTD partition support 877 CONFIG_CMD_NAND * NAND support 878 CONFIG_CMD_NET bootp, tftpboot, rarpboot 879 CONFIG_CMD_NFS NFS support 880 CONFIG_CMD_PCA953X * PCA953x I2C gpio commands 881 CONFIG_CMD_PCA953X_INFO * PCA953x I2C gpio info command 882 CONFIG_CMD_PCI * pciinfo 883 CONFIG_CMD_PCMCIA * PCMCIA support 884 CONFIG_CMD_PING * send ICMP ECHO_REQUEST to network 885 host 886 CONFIG_CMD_PORTIO * Port I/O 887 CONFIG_CMD_READ * Read raw data from partition 888 CONFIG_CMD_REGINFO * Register dump 889 CONFIG_CMD_RUN run command in env variable 890 CONFIG_CMD_SANDBOX * sb command to access sandbox features 891 CONFIG_CMD_SAVES * save S record dump 892 CONFIG_SCSI * SCSI Support 893 CONFIG_CMD_SDRAM * print SDRAM configuration information 894 (requires CONFIG_CMD_I2C) 895 CONFIG_CMD_SETGETDCR Support for DCR Register access 896 (4xx only) 897 CONFIG_CMD_SF * Read/write/erase SPI NOR flash 898 CONFIG_CMD_SHA1SUM * print sha1 memory digest 899 (requires CONFIG_CMD_MEMORY) 900 CONFIG_CMD_SOFTSWITCH * Soft switch setting command for BF60x 901 CONFIG_CMD_SOURCE "source" command Support 902 CONFIG_CMD_SPI * SPI serial bus support 903 CONFIG_CMD_TFTPSRV * TFTP transfer in server mode 904 CONFIG_CMD_TFTPPUT * TFTP put command (upload) 905 CONFIG_CMD_TIME * run command and report execution time (ARM specific) 906 CONFIG_CMD_TIMER * access to the system tick timer 907 CONFIG_CMD_USB * USB support 908 CONFIG_CMD_CDP * Cisco Discover Protocol support 909 CONFIG_CMD_MFSL * Microblaze FSL support 910 CONFIG_CMD_XIMG Load part of Multi Image 911 CONFIG_CMD_UUID * Generate random UUID or GUID string 912 913 EXAMPLE: If you want all functions except of network 914 support you can write: 915 916 #include "config_cmd_all.h" 917 #undef CONFIG_CMD_NET 918 919 Other Commands: 920 fdt (flattened device tree) command: CONFIG_OF_LIBFDT 921 922 Note: Don't enable the "icache" and "dcache" commands 923 (configuration option CONFIG_CMD_CACHE) unless you know 924 what you (and your U-Boot users) are doing. Data 925 cache cannot be enabled on systems like the 8xx or 926 8260 (where accesses to the IMMR region must be 927 uncached), and it cannot be disabled on all other 928 systems where we (mis-) use the data cache to hold an 929 initial stack and some data. 930 931 932 XXX - this list needs to get updated! 933 934- Removal of commands 935 If no commands are needed to boot, you can disable 936 CONFIG_CMDLINE to remove them. In this case, the command line 937 will not be available, and when U-Boot wants to execute the 938 boot command (on start-up) it will call board_run_command() 939 instead. This can reduce image size significantly for very 940 simple boot procedures. 941 942- Regular expression support: 943 CONFIG_REGEX 944 If this variable is defined, U-Boot is linked against 945 the SLRE (Super Light Regular Expression) library, 946 which adds regex support to some commands, as for 947 example "env grep" and "setexpr". 948 949- Device tree: 950 CONFIG_OF_CONTROL 951 If this variable is defined, U-Boot will use a device tree 952 to configure its devices, instead of relying on statically 953 compiled #defines in the board file. This option is 954 experimental and only available on a few boards. The device 955 tree is available in the global data as gd->fdt_blob. 956 957 U-Boot needs to get its device tree from somewhere. This can 958 be done using one of the three options below: 959 960 CONFIG_OF_EMBED 961 If this variable is defined, U-Boot will embed a device tree 962 binary in its image. This device tree file should be in the 963 board directory and called <soc>-<board>.dts. The binary file 964 is then picked up in board_init_f() and made available through 965 the global data structure as gd->blob. 966 967 CONFIG_OF_SEPARATE 968 If this variable is defined, U-Boot will build a device tree 969 binary. It will be called u-boot.dtb. Architecture-specific 970 code will locate it at run-time. Generally this works by: 971 972 cat u-boot.bin u-boot.dtb >image.bin 973 974 and in fact, U-Boot does this for you, creating a file called 975 u-boot-dtb.bin which is useful in the common case. You can 976 still use the individual files if you need something more 977 exotic. 978 979 CONFIG_OF_BOARD 980 If this variable is defined, U-Boot will use the device tree 981 provided by the board at runtime instead of embedding one with 982 the image. Only boards defining board_fdt_blob_setup() support 983 this option (see include/fdtdec.h file). 984 985- Watchdog: 986 CONFIG_WATCHDOG 987 If this variable is defined, it enables watchdog 988 support for the SoC. There must be support in the SoC 989 specific code for a watchdog. For the 8xx and 8260 990 CPUs, the SIU Watchdog feature is enabled in the SYPCR 991 register. When supported for a specific SoC is 992 available, then no further board specific code should 993 be needed to use it. 994 995 CONFIG_HW_WATCHDOG 996 When using a watchdog circuitry external to the used 997 SoC, then define this variable and provide board 998 specific code for the "hw_watchdog_reset" function. 999 1000 CONFIG_AT91_HW_WDT_TIMEOUT 1001 specify the timeout in seconds. default 2 seconds. 1002 1003- U-Boot Version: 1004 CONFIG_VERSION_VARIABLE 1005 If this variable is defined, an environment variable 1006 named "ver" is created by U-Boot showing the U-Boot 1007 version as printed by the "version" command. 1008 Any change to this variable will be reverted at the 1009 next reset. 1010 1011- Real-Time Clock: 1012 1013 When CONFIG_CMD_DATE is selected, the type of the RTC 1014 has to be selected, too. Define exactly one of the 1015 following options: 1016 1017 CONFIG_RTC_MPC8xx - use internal RTC of MPC8xx 1018 CONFIG_RTC_PCF8563 - use Philips PCF8563 RTC 1019 CONFIG_RTC_MC13XXX - use MC13783 or MC13892 RTC 1020 CONFIG_RTC_MC146818 - use MC146818 RTC 1021 CONFIG_RTC_DS1307 - use Maxim, Inc. DS1307 RTC 1022 CONFIG_RTC_DS1337 - use Maxim, Inc. DS1337 RTC 1023 CONFIG_RTC_DS1338 - use Maxim, Inc. DS1338 RTC 1024 CONFIG_RTC_DS1339 - use Maxim, Inc. DS1339 RTC 1025 CONFIG_RTC_DS164x - use Dallas DS164x RTC 1026 CONFIG_RTC_ISL1208 - use Intersil ISL1208 RTC 1027 CONFIG_RTC_MAX6900 - use Maxim, Inc. MAX6900 RTC 1028 CONFIG_SYS_RTC_DS1337_NOOSC - Turn off the OSC output for DS1337 1029 CONFIG_SYS_RV3029_TCR - enable trickle charger on 1030 RV3029 RTC. 1031 1032 Note that if the RTC uses I2C, then the I2C interface 1033 must also be configured. See I2C Support, below. 1034 1035- GPIO Support: 1036 CONFIG_PCA953X - use NXP's PCA953X series I2C GPIO 1037 1038 The CONFIG_SYS_I2C_PCA953X_WIDTH option specifies a list of 1039 chip-ngpio pairs that tell the PCA953X driver the number of 1040 pins supported by a particular chip. 1041 1042 Note that if the GPIO device uses I2C, then the I2C interface 1043 must also be configured. See I2C Support, below. 1044 1045- I/O tracing: 1046 When CONFIG_IO_TRACE is selected, U-Boot intercepts all I/O 1047 accesses and can checksum them or write a list of them out 1048 to memory. See the 'iotrace' command for details. This is 1049 useful for testing device drivers since it can confirm that 1050 the driver behaves the same way before and after a code 1051 change. Currently this is supported on sandbox and arm. To 1052 add support for your architecture, add '#include <iotrace.h>' 1053 to the bottom of arch/<arch>/include/asm/io.h and test. 1054 1055 Example output from the 'iotrace stats' command is below. 1056 Note that if the trace buffer is exhausted, the checksum will 1057 still continue to operate. 1058 1059 iotrace is enabled 1060 Start: 10000000 (buffer start address) 1061 Size: 00010000 (buffer size) 1062 Offset: 00000120 (current buffer offset) 1063 Output: 10000120 (start + offset) 1064 Count: 00000018 (number of trace records) 1065 CRC32: 9526fb66 (CRC32 of all trace records) 1066 1067- Timestamp Support: 1068 1069 When CONFIG_TIMESTAMP is selected, the timestamp 1070 (date and time) of an image is printed by image 1071 commands like bootm or iminfo. This option is 1072 automatically enabled when you select CONFIG_CMD_DATE . 1073 1074- Partition Labels (disklabels) Supported: 1075 Zero or more of the following: 1076 CONFIG_MAC_PARTITION Apple's MacOS partition table. 1077 CONFIG_DOS_PARTITION MS Dos partition table, traditional on the 1078 Intel architecture, USB sticks, etc. 1079 CONFIG_ISO_PARTITION ISO partition table, used on CDROM etc. 1080 CONFIG_EFI_PARTITION GPT partition table, common when EFI is the 1081 bootloader. Note 2TB partition limit; see 1082 disk/part_efi.c 1083 CONFIG_MTD_PARTITIONS Memory Technology Device partition table. 1084 1085 If IDE or SCSI support is enabled (CONFIG_CMD_IDE or 1086 CONFIG_SCSI) you must configure support for at 1087 least one non-MTD partition type as well. 1088 1089- IDE Reset method: 1090 CONFIG_IDE_RESET_ROUTINE - this is defined in several 1091 board configurations files but used nowhere! 1092 1093 CONFIG_IDE_RESET - is this is defined, IDE Reset will 1094 be performed by calling the function 1095 ide_set_reset(int reset) 1096 which has to be defined in a board specific file 1097 1098- ATAPI Support: 1099 CONFIG_ATAPI 1100 1101 Set this to enable ATAPI support. 1102 1103- LBA48 Support 1104 CONFIG_LBA48 1105 1106 Set this to enable support for disks larger than 137GB 1107 Also look at CONFIG_SYS_64BIT_LBA. 1108 Whithout these , LBA48 support uses 32bit variables and will 'only' 1109 support disks up to 2.1TB. 1110 1111 CONFIG_SYS_64BIT_LBA: 1112 When enabled, makes the IDE subsystem use 64bit sector addresses. 1113 Default is 32bit. 1114 1115- SCSI Support: 1116 At the moment only there is only support for the 1117 SYM53C8XX SCSI controller; define 1118 CONFIG_SCSI_SYM53C8XX to enable it. 1119 1120 CONFIG_SYS_SCSI_MAX_LUN [8], CONFIG_SYS_SCSI_MAX_SCSI_ID [7] and 1121 CONFIG_SYS_SCSI_MAX_DEVICE [CONFIG_SYS_SCSI_MAX_SCSI_ID * 1122 CONFIG_SYS_SCSI_MAX_LUN] can be adjusted to define the 1123 maximum numbers of LUNs, SCSI ID's and target 1124 devices. 1125 CONFIG_SYS_SCSI_SYM53C8XX_CCF to fix clock timing (80Mhz) 1126 1127 The environment variable 'scsidevs' is set to the number of 1128 SCSI devices found during the last scan. 1129 1130- NETWORK Support (PCI): 1131 CONFIG_E1000 1132 Support for Intel 8254x/8257x gigabit chips. 1133 1134 CONFIG_E1000_SPI 1135 Utility code for direct access to the SPI bus on Intel 8257x. 1136 This does not do anything useful unless you set at least one 1137 of CONFIG_CMD_E1000 or CONFIG_E1000_SPI_GENERIC. 1138 1139 CONFIG_E1000_SPI_GENERIC 1140 Allow generic access to the SPI bus on the Intel 8257x, for 1141 example with the "sspi" command. 1142 1143 CONFIG_CMD_E1000 1144 Management command for E1000 devices. When used on devices 1145 with SPI support you can reprogram the EEPROM from U-Boot. 1146 1147 CONFIG_EEPRO100 1148 Support for Intel 82557/82559/82559ER chips. 1149 Optional CONFIG_EEPRO100_SROM_WRITE enables EEPROM 1150 write routine for first time initialisation. 1151 1152 CONFIG_TULIP 1153 Support for Digital 2114x chips. 1154 Optional CONFIG_TULIP_SELECT_MEDIA for board specific 1155 modem chip initialisation (KS8761/QS6611). 1156 1157 CONFIG_NATSEMI 1158 Support for National dp83815 chips. 1159 1160 CONFIG_NS8382X 1161 Support for National dp8382[01] gigabit chips. 1162 1163- NETWORK Support (other): 1164 1165 CONFIG_DRIVER_AT91EMAC 1166 Support for AT91RM9200 EMAC. 1167 1168 CONFIG_RMII 1169 Define this to use reduced MII inteface 1170 1171 CONFIG_DRIVER_AT91EMAC_QUIET 1172 If this defined, the driver is quiet. 1173 The driver doen't show link status messages. 1174 1175 CONFIG_CALXEDA_XGMAC 1176 Support for the Calxeda XGMAC device 1177 1178 CONFIG_LAN91C96 1179 Support for SMSC's LAN91C96 chips. 1180 1181 CONFIG_LAN91C96_USE_32_BIT 1182 Define this to enable 32 bit addressing 1183 1184 CONFIG_SMC91111 1185 Support for SMSC's LAN91C111 chip 1186 1187 CONFIG_SMC91111_BASE 1188 Define this to hold the physical address 1189 of the device (I/O space) 1190 1191 CONFIG_SMC_USE_32_BIT 1192 Define this if data bus is 32 bits 1193 1194 CONFIG_SMC_USE_IOFUNCS 1195 Define this to use i/o functions instead of macros 1196 (some hardware wont work with macros) 1197 1198 CONFIG_DRIVER_TI_EMAC 1199 Support for davinci emac 1200 1201 CONFIG_SYS_DAVINCI_EMAC_PHY_COUNT 1202 Define this if you have more then 3 PHYs. 1203 1204 CONFIG_FTGMAC100 1205 Support for Faraday's FTGMAC100 Gigabit SoC Ethernet 1206 1207 CONFIG_FTGMAC100_EGIGA 1208 Define this to use GE link update with gigabit PHY. 1209 Define this if FTGMAC100 is connected to gigabit PHY. 1210 If your system has 10/100 PHY only, it might not occur 1211 wrong behavior. Because PHY usually return timeout or 1212 useless data when polling gigabit status and gigabit 1213 control registers. This behavior won't affect the 1214 correctnessof 10/100 link speed update. 1215 1216 CONFIG_SMC911X 1217 Support for SMSC's LAN911x and LAN921x chips 1218 1219 CONFIG_SMC911X_BASE 1220 Define this to hold the physical address 1221 of the device (I/O space) 1222 1223 CONFIG_SMC911X_32_BIT 1224 Define this if data bus is 32 bits 1225 1226 CONFIG_SMC911X_16_BIT 1227 Define this if data bus is 16 bits. If your processor 1228 automatically converts one 32 bit word to two 16 bit 1229 words you may also try CONFIG_SMC911X_32_BIT. 1230 1231 CONFIG_SH_ETHER 1232 Support for Renesas on-chip Ethernet controller 1233 1234 CONFIG_SH_ETHER_USE_PORT 1235 Define the number of ports to be used 1236 1237 CONFIG_SH_ETHER_PHY_ADDR 1238 Define the ETH PHY's address 1239 1240 CONFIG_SH_ETHER_CACHE_WRITEBACK 1241 If this option is set, the driver enables cache flush. 1242 1243- PWM Support: 1244 CONFIG_PWM_IMX 1245 Support for PWM module on the imx6. 1246 1247- TPM Support: 1248 CONFIG_TPM 1249 Support TPM devices. 1250 1251 CONFIG_TPM_TIS_INFINEON 1252 Support for Infineon i2c bus TPM devices. Only one device 1253 per system is supported at this time. 1254 1255 CONFIG_TPM_TIS_I2C_BURST_LIMITATION 1256 Define the burst count bytes upper limit 1257 1258 CONFIG_TPM_ST33ZP24 1259 Support for STMicroelectronics TPM devices. Requires DM_TPM support. 1260 1261 CONFIG_TPM_ST33ZP24_I2C 1262 Support for STMicroelectronics ST33ZP24 I2C devices. 1263 Requires TPM_ST33ZP24 and I2C. 1264 1265 CONFIG_TPM_ST33ZP24_SPI 1266 Support for STMicroelectronics ST33ZP24 SPI devices. 1267 Requires TPM_ST33ZP24 and SPI. 1268 1269 CONFIG_TPM_ATMEL_TWI 1270 Support for Atmel TWI TPM device. Requires I2C support. 1271 1272 CONFIG_TPM_TIS_LPC 1273 Support for generic parallel port TPM devices. Only one device 1274 per system is supported at this time. 1275 1276 CONFIG_TPM_TIS_BASE_ADDRESS 1277 Base address where the generic TPM device is mapped 1278 to. Contemporary x86 systems usually map it at 1279 0xfed40000. 1280 1281 CONFIG_CMD_TPM 1282 Add tpm monitor functions. 1283 Requires CONFIG_TPM. If CONFIG_TPM_AUTH_SESSIONS is set, also 1284 provides monitor access to authorized functions. 1285 1286 CONFIG_TPM 1287 Define this to enable the TPM support library which provides 1288 functional interfaces to some TPM commands. 1289 Requires support for a TPM device. 1290 1291 CONFIG_TPM_AUTH_SESSIONS 1292 Define this to enable authorized functions in the TPM library. 1293 Requires CONFIG_TPM and CONFIG_SHA1. 1294 1295- USB Support: 1296 At the moment only the UHCI host controller is 1297 supported (PIP405, MIP405, MPC5200); define 1298 CONFIG_USB_UHCI to enable it. 1299 define CONFIG_USB_KEYBOARD to enable the USB Keyboard 1300 and define CONFIG_USB_STORAGE to enable the USB 1301 storage devices. 1302 Note: 1303 Supported are USB Keyboards and USB Floppy drives 1304 (TEAC FD-05PUB). 1305 MPC5200 USB requires additional defines: 1306 CONFIG_USB_CLOCK 1307 for 528 MHz Clock: 0x0001bbbb 1308 CONFIG_PSC3_USB 1309 for USB on PSC3 1310 CONFIG_USB_CONFIG 1311 for differential drivers: 0x00001000 1312 for single ended drivers: 0x00005000 1313 for differential drivers on PSC3: 0x00000100 1314 for single ended drivers on PSC3: 0x00004100 1315 CONFIG_SYS_USB_EVENT_POLL 1316 May be defined to allow interrupt polling 1317 instead of using asynchronous interrupts 1318 1319 CONFIG_USB_EHCI_TXFIFO_THRESH enables setting of the 1320 txfilltuning field in the EHCI controller on reset. 1321 1322 CONFIG_USB_DWC2_REG_ADDR the physical CPU address of the DWC2 1323 HW module registers. 1324 1325- USB Device: 1326 Define the below if you wish to use the USB console. 1327 Once firmware is rebuilt from a serial console issue the 1328 command "setenv stdin usbtty; setenv stdout usbtty" and 1329 attach your USB cable. The Unix command "dmesg" should print 1330 it has found a new device. The environment variable usbtty 1331 can be set to gserial or cdc_acm to enable your device to 1332 appear to a USB host as a Linux gserial device or a 1333 Common Device Class Abstract Control Model serial device. 1334 If you select usbtty = gserial you should be able to enumerate 1335 a Linux host by 1336 # modprobe usbserial vendor=0xVendorID product=0xProductID 1337 else if using cdc_acm, simply setting the environment 1338 variable usbtty to be cdc_acm should suffice. The following 1339 might be defined in YourBoardName.h 1340 1341 CONFIG_USB_DEVICE 1342 Define this to build a UDC device 1343 1344 CONFIG_USB_TTY 1345 Define this to have a tty type of device available to 1346 talk to the UDC device 1347 1348 CONFIG_USBD_HS 1349 Define this to enable the high speed support for usb 1350 device and usbtty. If this feature is enabled, a routine 1351 int is_usbd_high_speed(void) 1352 also needs to be defined by the driver to dynamically poll 1353 whether the enumeration has succeded at high speed or full 1354 speed. 1355 1356 CONFIG_SYS_CONSOLE_IS_IN_ENV 1357 Define this if you want stdin, stdout &/or stderr to 1358 be set to usbtty. 1359 1360 mpc8xx: 1361 CONFIG_SYS_USB_EXTC_CLK 0xBLAH 1362 Derive USB clock from external clock "blah" 1363 - CONFIG_SYS_USB_EXTC_CLK 0x02 1364 1365 If you have a USB-IF assigned VendorID then you may wish to 1366 define your own vendor specific values either in BoardName.h 1367 or directly in usbd_vendor_info.h. If you don't define 1368 CONFIG_USBD_MANUFACTURER, CONFIG_USBD_PRODUCT_NAME, 1369 CONFIG_USBD_VENDORID and CONFIG_USBD_PRODUCTID, then U-Boot 1370 should pretend to be a Linux device to it's target host. 1371 1372 CONFIG_USBD_MANUFACTURER 1373 Define this string as the name of your company for 1374 - CONFIG_USBD_MANUFACTURER "my company" 1375 1376 CONFIG_USBD_PRODUCT_NAME 1377 Define this string as the name of your product 1378 - CONFIG_USBD_PRODUCT_NAME "acme usb device" 1379 1380 CONFIG_USBD_VENDORID 1381 Define this as your assigned Vendor ID from the USB 1382 Implementors Forum. This *must* be a genuine Vendor ID 1383 to avoid polluting the USB namespace. 1384 - CONFIG_USBD_VENDORID 0xFFFF 1385 1386 CONFIG_USBD_PRODUCTID 1387 Define this as the unique Product ID 1388 for your device 1389 - CONFIG_USBD_PRODUCTID 0xFFFF 1390 1391- ULPI Layer Support: 1392 The ULPI (UTMI Low Pin (count) Interface) PHYs are supported via 1393 the generic ULPI layer. The generic layer accesses the ULPI PHY 1394 via the platform viewport, so you need both the genric layer and 1395 the viewport enabled. Currently only Chipidea/ARC based 1396 viewport is supported. 1397 To enable the ULPI layer support, define CONFIG_USB_ULPI and 1398 CONFIG_USB_ULPI_VIEWPORT in your board configuration file. 1399 If your ULPI phy needs a different reference clock than the 1400 standard 24 MHz then you have to define CONFIG_ULPI_REF_CLK to 1401 the appropriate value in Hz. 1402 1403- MMC Support: 1404 The MMC controller on the Intel PXA is supported. To 1405 enable this define CONFIG_MMC. The MMC can be 1406 accessed from the boot prompt by mapping the device 1407 to physical memory similar to flash. Command line is 1408 enabled with CONFIG_CMD_MMC. The MMC driver also works with 1409 the FAT fs. This is enabled with CONFIG_CMD_FAT. 1410 1411 CONFIG_SH_MMCIF 1412 Support for Renesas on-chip MMCIF controller 1413 1414 CONFIG_SH_MMCIF_ADDR 1415 Define the base address of MMCIF registers 1416 1417 CONFIG_SH_MMCIF_CLK 1418 Define the clock frequency for MMCIF 1419 1420 CONFIG_SUPPORT_EMMC_BOOT 1421 Enable some additional features of the eMMC boot partitions. 1422 1423 CONFIG_SUPPORT_EMMC_RPMB 1424 Enable the commands for reading, writing and programming the 1425 key for the Replay Protection Memory Block partition in eMMC. 1426 1427- USB Device Firmware Update (DFU) class support: 1428 CONFIG_USB_FUNCTION_DFU 1429 This enables the USB portion of the DFU USB class 1430 1431 CONFIG_CMD_DFU 1432 This enables the command "dfu" which is used to have 1433 U-Boot create a DFU class device via USB. This command 1434 requires that the "dfu_alt_info" environment variable be 1435 set and define the alt settings to expose to the host. 1436 1437 CONFIG_DFU_MMC 1438 This enables support for exposing (e)MMC devices via DFU. 1439 1440 CONFIG_DFU_NAND 1441 This enables support for exposing NAND devices via DFU. 1442 1443 CONFIG_DFU_RAM 1444 This enables support for exposing RAM via DFU. 1445 Note: DFU spec refer to non-volatile memory usage, but 1446 allow usages beyond the scope of spec - here RAM usage, 1447 one that would help mostly the developer. 1448 1449 CONFIG_SYS_DFU_DATA_BUF_SIZE 1450 Dfu transfer uses a buffer before writing data to the 1451 raw storage device. Make the size (in bytes) of this buffer 1452 configurable. The size of this buffer is also configurable 1453 through the "dfu_bufsiz" environment variable. 1454 1455 CONFIG_SYS_DFU_MAX_FILE_SIZE 1456 When updating files rather than the raw storage device, 1457 we use a static buffer to copy the file into and then write 1458 the buffer once we've been given the whole file. Define 1459 this to the maximum filesize (in bytes) for the buffer. 1460 Default is 4 MiB if undefined. 1461 1462 DFU_DEFAULT_POLL_TIMEOUT 1463 Poll timeout [ms], is the timeout a device can send to the 1464 host. The host must wait for this timeout before sending 1465 a subsequent DFU_GET_STATUS request to the device. 1466 1467 DFU_MANIFEST_POLL_TIMEOUT 1468 Poll timeout [ms], which the device sends to the host when 1469 entering dfuMANIFEST state. Host waits this timeout, before 1470 sending again an USB request to the device. 1471 1472- USB Device Android Fastboot support: 1473 CONFIG_USB_FUNCTION_FASTBOOT 1474 This enables the USB part of the fastboot gadget 1475 1476 CONFIG_CMD_FASTBOOT 1477 This enables the command "fastboot" which enables the Android 1478 fastboot mode for the platform's USB device. Fastboot is a USB 1479 protocol for downloading images, flashing and device control 1480 used on Android devices. 1481 See doc/README.android-fastboot for more information. 1482 1483 CONFIG_ANDROID_BOOT_IMAGE 1484 This enables support for booting images which use the Android 1485 image format header. 1486 1487 CONFIG_FASTBOOT_BUF_ADDR 1488 The fastboot protocol requires a large memory buffer for 1489 downloads. Define this to the starting RAM address to use for 1490 downloaded images. 1491 1492 CONFIG_FASTBOOT_BUF_SIZE 1493 The fastboot protocol requires a large memory buffer for 1494 downloads. This buffer should be as large as possible for a 1495 platform. Define this to the size available RAM for fastboot. 1496 1497 CONFIG_FASTBOOT_FLASH 1498 The fastboot protocol includes a "flash" command for writing 1499 the downloaded image to a non-volatile storage device. Define 1500 this to enable the "fastboot flash" command. 1501 1502 CONFIG_FASTBOOT_FLASH_MMC_DEV 1503 The fastboot "flash" command requires additional information 1504 regarding the non-volatile storage device. Define this to 1505 the eMMC device that fastboot should use to store the image. 1506 1507 CONFIG_FASTBOOT_GPT_NAME 1508 The fastboot "flash" command supports writing the downloaded 1509 image to the Protective MBR and the Primary GUID Partition 1510 Table. (Additionally, this downloaded image is post-processed 1511 to generate and write the Backup GUID Partition Table.) 1512 This occurs when the specified "partition name" on the 1513 "fastboot flash" command line matches this value. 1514 The default is "gpt" if undefined. 1515 1516 CONFIG_FASTBOOT_MBR_NAME 1517 The fastboot "flash" command supports writing the downloaded 1518 image to DOS MBR. 1519 This occurs when the "partition name" specified on the 1520 "fastboot flash" command line matches this value. 1521 If not defined the default value "mbr" is used. 1522 1523- Journaling Flash filesystem support: 1524 CONFIG_JFFS2_NAND 1525 Define these for a default partition on a NAND device 1526 1527 CONFIG_SYS_JFFS2_FIRST_SECTOR, 1528 CONFIG_SYS_JFFS2_FIRST_BANK, CONFIG_SYS_JFFS2_NUM_BANKS 1529 Define these for a default partition on a NOR device 1530 1531- FAT(File Allocation Table) filesystem write function support: 1532 CONFIG_FAT_WRITE 1533 1534 Define this to enable support for saving memory data as a 1535 file in FAT formatted partition. 1536 1537 This will also enable the command "fatwrite" enabling the 1538 user to write files to FAT. 1539 1540- FAT(File Allocation Table) filesystem cluster size: 1541 CONFIG_FS_FAT_MAX_CLUSTSIZE 1542 1543 Define the max cluster size for fat operations else 1544 a default value of 65536 will be defined. 1545 1546- Keyboard Support: 1547 See Kconfig help for available keyboard drivers. 1548 1549 CONFIG_KEYBOARD 1550 1551 Define this to enable a custom keyboard support. 1552 This simply calls drv_keyboard_init() which must be 1553 defined in your board-specific files. This option is deprecated 1554 and is only used by novena. For new boards, use driver model 1555 instead. 1556 1557- Video support: 1558 CONFIG_FSL_DIU_FB 1559 Enable the Freescale DIU video driver. Reference boards for 1560 SOCs that have a DIU should define this macro to enable DIU 1561 support, and should also define these other macros: 1562 1563 CONFIG_SYS_DIU_ADDR 1564 CONFIG_VIDEO 1565 CONFIG_CFB_CONSOLE 1566 CONFIG_VIDEO_SW_CURSOR 1567 CONFIG_VGA_AS_SINGLE_DEVICE 1568 CONFIG_VIDEO_LOGO 1569 CONFIG_VIDEO_BMP_LOGO 1570 1571 The DIU driver will look for the 'video-mode' environment 1572 variable, and if defined, enable the DIU as a console during 1573 boot. See the documentation file doc/README.video for a 1574 description of this variable. 1575 1576- LCD Support: CONFIG_LCD 1577 1578 Define this to enable LCD support (for output to LCD 1579 display); also select one of the supported displays 1580 by defining one of these: 1581 1582 CONFIG_ATMEL_LCD: 1583 1584 HITACHI TX09D70VM1CCA, 3.5", 240x320. 1585 1586 CONFIG_NEC_NL6448AC33: 1587 1588 NEC NL6448AC33-18. Active, color, single scan. 1589 1590 CONFIG_NEC_NL6448BC20 1591 1592 NEC NL6448BC20-08. 6.5", 640x480. 1593 Active, color, single scan. 1594 1595 CONFIG_NEC_NL6448BC33_54 1596 1597 NEC NL6448BC33-54. 10.4", 640x480. 1598 Active, color, single scan. 1599 1600 CONFIG_SHARP_16x9 1601 1602 Sharp 320x240. Active, color, single scan. 1603 It isn't 16x9, and I am not sure what it is. 1604 1605 CONFIG_SHARP_LQ64D341 1606 1607 Sharp LQ64D341 display, 640x480. 1608 Active, color, single scan. 1609 1610 CONFIG_HLD1045 1611 1612 HLD1045 display, 640x480. 1613 Active, color, single scan. 1614 1615 CONFIG_OPTREX_BW 1616 1617 Optrex CBL50840-2 NF-FW 99 22 M5 1618 or 1619 Hitachi LMG6912RPFC-00T 1620 or 1621 Hitachi SP14Q002 1622 1623 320x240. Black & white. 1624 1625 CONFIG_LCD_ALIGNMENT 1626 1627 Normally the LCD is page-aligned (typically 4KB). If this is 1628 defined then the LCD will be aligned to this value instead. 1629 For ARM it is sometimes useful to use MMU_SECTION_SIZE 1630 here, since it is cheaper to change data cache settings on 1631 a per-section basis. 1632 1633 1634 CONFIG_LCD_ROTATION 1635 1636 Sometimes, for example if the display is mounted in portrait 1637 mode or even if it's mounted landscape but rotated by 180degree, 1638 we need to rotate our content of the display relative to the 1639 framebuffer, so that user can read the messages which are 1640 printed out. 1641 Once CONFIG_LCD_ROTATION is defined, the lcd_console will be 1642 initialized with a given rotation from "vl_rot" out of 1643 "vidinfo_t" which is provided by the board specific code. 1644 The value for vl_rot is coded as following (matching to 1645 fbcon=rotate:<n> linux-kernel commandline): 1646 0 = no rotation respectively 0 degree 1647 1 = 90 degree rotation 1648 2 = 180 degree rotation 1649 3 = 270 degree rotation 1650 1651 If CONFIG_LCD_ROTATION is not defined, the console will be 1652 initialized with 0degree rotation. 1653 1654 CONFIG_LCD_BMP_RLE8 1655 1656 Support drawing of RLE8-compressed bitmaps on the LCD. 1657 1658 CONFIG_I2C_EDID 1659 1660 Enables an 'i2c edid' command which can read EDID 1661 information over I2C from an attached LCD display. 1662 1663- Splash Screen Support: CONFIG_SPLASH_SCREEN 1664 1665 If this option is set, the environment is checked for 1666 a variable "splashimage". If found, the usual display 1667 of logo, copyright and system information on the LCD 1668 is suppressed and the BMP image at the address 1669 specified in "splashimage" is loaded instead. The 1670 console is redirected to the "nulldev", too. This 1671 allows for a "silent" boot where a splash screen is 1672 loaded very quickly after power-on. 1673 1674 CONFIG_SPLASHIMAGE_GUARD 1675 1676 If this option is set, then U-Boot will prevent the environment 1677 variable "splashimage" from being set to a problematic address 1678 (see doc/README.displaying-bmps). 1679 This option is useful for targets where, due to alignment 1680 restrictions, an improperly aligned BMP image will cause a data 1681 abort. If you think you will not have problems with unaligned 1682 accesses (for example because your toolchain prevents them) 1683 there is no need to set this option. 1684 1685 CONFIG_SPLASH_SCREEN_ALIGN 1686 1687 If this option is set the splash image can be freely positioned 1688 on the screen. Environment variable "splashpos" specifies the 1689 position as "x,y". If a positive number is given it is used as 1690 number of pixel from left/top. If a negative number is given it 1691 is used as number of pixel from right/bottom. You can also 1692 specify 'm' for centering the image. 1693 1694 Example: 1695 setenv splashpos m,m 1696 => image at center of screen 1697 1698 setenv splashpos 30,20 1699 => image at x = 30 and y = 20 1700 1701 setenv splashpos -10,m 1702 => vertically centered image 1703 at x = dspWidth - bmpWidth - 9 1704 1705- Gzip compressed BMP image support: CONFIG_VIDEO_BMP_GZIP 1706 1707 If this option is set, additionally to standard BMP 1708 images, gzipped BMP images can be displayed via the 1709 splashscreen support or the bmp command. 1710 1711- Run length encoded BMP image (RLE8) support: CONFIG_VIDEO_BMP_RLE8 1712 1713 If this option is set, 8-bit RLE compressed BMP images 1714 can be displayed via the splashscreen support or the 1715 bmp command. 1716 1717- Compression support: 1718 CONFIG_GZIP 1719 1720 Enabled by default to support gzip compressed images. 1721 1722 CONFIG_BZIP2 1723 1724 If this option is set, support for bzip2 compressed 1725 images is included. If not, only uncompressed and gzip 1726 compressed images are supported. 1727 1728 NOTE: the bzip2 algorithm requires a lot of RAM, so 1729 the malloc area (as defined by CONFIG_SYS_MALLOC_LEN) should 1730 be at least 4MB. 1731 1732 CONFIG_LZMA 1733 1734 If this option is set, support for lzma compressed 1735 images is included. 1736 1737 Note: The LZMA algorithm adds between 2 and 4KB of code and it 1738 requires an amount of dynamic memory that is given by the 1739 formula: 1740 1741 (1846 + 768 << (lc + lp)) * sizeof(uint16) 1742 1743 Where lc and lp stand for, respectively, Literal context bits 1744 and Literal pos bits. 1745 1746 This value is upper-bounded by 14MB in the worst case. Anyway, 1747 for a ~4MB large kernel image, we have lc=3 and lp=0 for a 1748 total amount of (1846 + 768 << (3 + 0)) * 2 = ~41KB... that is 1749 a very small buffer. 1750 1751 Use the lzmainfo tool to determinate the lc and lp values and 1752 then calculate the amount of needed dynamic memory (ensuring 1753 the appropriate CONFIG_SYS_MALLOC_LEN value). 1754 1755 CONFIG_LZO 1756 1757 If this option is set, support for LZO compressed images 1758 is included. 1759 1760- MII/PHY support: 1761 CONFIG_PHY_ADDR 1762 1763 The address of PHY on MII bus. 1764 1765 CONFIG_PHY_CLOCK_FREQ (ppc4xx) 1766 1767 The clock frequency of the MII bus 1768 1769 CONFIG_PHY_GIGE 1770 1771 If this option is set, support for speed/duplex 1772 detection of gigabit PHY is included. 1773 1774 CONFIG_PHY_RESET_DELAY 1775 1776 Some PHY like Intel LXT971A need extra delay after 1777 reset before any MII register access is possible. 1778 For such PHY, set this option to the usec delay 1779 required. (minimum 300usec for LXT971A) 1780 1781 CONFIG_PHY_CMD_DELAY (ppc4xx) 1782 1783 Some PHY like Intel LXT971A need extra delay after 1784 command issued before MII status register can be read 1785 1786- IP address: 1787 CONFIG_IPADDR 1788 1789 Define a default value for the IP address to use for 1790 the default Ethernet interface, in case this is not 1791 determined through e.g. bootp. 1792 (Environment variable "ipaddr") 1793 1794- Server IP address: 1795 CONFIG_SERVERIP 1796 1797 Defines a default value for the IP address of a TFTP 1798 server to contact when using the "tftboot" command. 1799 (Environment variable "serverip") 1800 1801 CONFIG_KEEP_SERVERADDR 1802 1803 Keeps the server's MAC address, in the env 'serveraddr' 1804 for passing to bootargs (like Linux's netconsole option) 1805 1806- Gateway IP address: 1807 CONFIG_GATEWAYIP 1808 1809 Defines a default value for the IP address of the 1810 default router where packets to other networks are 1811 sent to. 1812 (Environment variable "gatewayip") 1813 1814- Subnet mask: 1815 CONFIG_NETMASK 1816 1817 Defines a default value for the subnet mask (or 1818 routing prefix) which is used to determine if an IP 1819 address belongs to the local subnet or needs to be 1820 forwarded through a router. 1821 (Environment variable "netmask") 1822 1823- Multicast TFTP Mode: 1824 CONFIG_MCAST_TFTP 1825 1826 Defines whether you want to support multicast TFTP as per 1827 rfc-2090; for example to work with atftp. Lets lots of targets 1828 tftp down the same boot image concurrently. Note: the Ethernet 1829 driver in use must provide a function: mcast() to join/leave a 1830 multicast group. 1831 1832- BOOTP Recovery Mode: 1833 CONFIG_BOOTP_RANDOM_DELAY 1834 1835 If you have many targets in a network that try to 1836 boot using BOOTP, you may want to avoid that all 1837 systems send out BOOTP requests at precisely the same 1838 moment (which would happen for instance at recovery 1839 from a power failure, when all systems will try to 1840 boot, thus flooding the BOOTP server. Defining 1841 CONFIG_BOOTP_RANDOM_DELAY causes a random delay to be 1842 inserted before sending out BOOTP requests. The 1843 following delays are inserted then: 1844 1845 1st BOOTP request: delay 0 ... 1 sec 1846 2nd BOOTP request: delay 0 ... 2 sec 1847 3rd BOOTP request: delay 0 ... 4 sec 1848 4th and following 1849 BOOTP requests: delay 0 ... 8 sec 1850 1851 CONFIG_BOOTP_ID_CACHE_SIZE 1852 1853 BOOTP packets are uniquely identified using a 32-bit ID. The 1854 server will copy the ID from client requests to responses and 1855 U-Boot will use this to determine if it is the destination of 1856 an incoming response. Some servers will check that addresses 1857 aren't in use before handing them out (usually using an ARP 1858 ping) and therefore take up to a few hundred milliseconds to 1859 respond. Network congestion may also influence the time it 1860 takes for a response to make it back to the client. If that 1861 time is too long, U-Boot will retransmit requests. In order 1862 to allow earlier responses to still be accepted after these 1863 retransmissions, U-Boot's BOOTP client keeps a small cache of 1864 IDs. The CONFIG_BOOTP_ID_CACHE_SIZE controls the size of this 1865 cache. The default is to keep IDs for up to four outstanding 1866 requests. Increasing this will allow U-Boot to accept offers 1867 from a BOOTP client in networks with unusually high latency. 1868 1869- DHCP Advanced Options: 1870 You can fine tune the DHCP functionality by defining 1871 CONFIG_BOOTP_* symbols: 1872 1873 CONFIG_BOOTP_SUBNETMASK 1874 CONFIG_BOOTP_GATEWAY 1875 CONFIG_BOOTP_HOSTNAME 1876 CONFIG_BOOTP_NISDOMAIN 1877 CONFIG_BOOTP_BOOTPATH 1878 CONFIG_BOOTP_BOOTFILESIZE 1879 CONFIG_BOOTP_DNS 1880 CONFIG_BOOTP_DNS2 1881 CONFIG_BOOTP_SEND_HOSTNAME 1882 CONFIG_BOOTP_NTPSERVER 1883 CONFIG_BOOTP_TIMEOFFSET 1884 CONFIG_BOOTP_VENDOREX 1885 CONFIG_BOOTP_MAY_FAIL 1886 1887 CONFIG_BOOTP_SERVERIP - TFTP server will be the serverip 1888 environment variable, not the BOOTP server. 1889 1890 CONFIG_BOOTP_MAY_FAIL - If the DHCP server is not found 1891 after the configured retry count, the call will fail 1892 instead of starting over. This can be used to fail over 1893 to Link-local IP address configuration if the DHCP server 1894 is not available. 1895 1896 CONFIG_BOOTP_DNS2 - If a DHCP client requests the DNS 1897 serverip from a DHCP server, it is possible that more 1898 than one DNS serverip is offered to the client. 1899 If CONFIG_BOOTP_DNS2 is enabled, the secondary DNS 1900 serverip will be stored in the additional environment 1901 variable "dnsip2". The first DNS serverip is always 1902 stored in the variable "dnsip", when CONFIG_BOOTP_DNS 1903 is defined. 1904 1905 CONFIG_BOOTP_SEND_HOSTNAME - Some DHCP servers are capable 1906 to do a dynamic update of a DNS server. To do this, they 1907 need the hostname of the DHCP requester. 1908 If CONFIG_BOOTP_SEND_HOSTNAME is defined, the content 1909 of the "hostname" environment variable is passed as 1910 option 12 to the DHCP server. 1911 1912 CONFIG_BOOTP_DHCP_REQUEST_DELAY 1913 1914 A 32bit value in microseconds for a delay between 1915 receiving a "DHCP Offer" and sending the "DHCP Request". 1916 This fixes a problem with certain DHCP servers that don't 1917 respond 100% of the time to a "DHCP request". E.g. On an 1918 AT91RM9200 processor running at 180MHz, this delay needed 1919 to be *at least* 15,000 usec before a Windows Server 2003 1920 DHCP server would reply 100% of the time. I recommend at 1921 least 50,000 usec to be safe. The alternative is to hope 1922 that one of the retries will be successful but note that 1923 the DHCP timeout and retry process takes a longer than 1924 this delay. 1925 1926 - Link-local IP address negotiation: 1927 Negotiate with other link-local clients on the local network 1928 for an address that doesn't require explicit configuration. 1929 This is especially useful if a DHCP server cannot be guaranteed 1930 to exist in all environments that the device must operate. 1931 1932 See doc/README.link-local for more information. 1933 1934 - CDP Options: 1935 CONFIG_CDP_DEVICE_ID 1936 1937 The device id used in CDP trigger frames. 1938 1939 CONFIG_CDP_DEVICE_ID_PREFIX 1940 1941 A two character string which is prefixed to the MAC address 1942 of the device. 1943 1944 CONFIG_CDP_PORT_ID 1945 1946 A printf format string which contains the ascii name of 1947 the port. Normally is set to "eth%d" which sets 1948 eth0 for the first Ethernet, eth1 for the second etc. 1949 1950 CONFIG_CDP_CAPABILITIES 1951 1952 A 32bit integer which indicates the device capabilities; 1953 0x00000010 for a normal host which does not forwards. 1954 1955 CONFIG_CDP_VERSION 1956 1957 An ascii string containing the version of the software. 1958 1959 CONFIG_CDP_PLATFORM 1960 1961 An ascii string containing the name of the platform. 1962 1963 CONFIG_CDP_TRIGGER 1964 1965 A 32bit integer sent on the trigger. 1966 1967 CONFIG_CDP_POWER_CONSUMPTION 1968 1969 A 16bit integer containing the power consumption of the 1970 device in .1 of milliwatts. 1971 1972 CONFIG_CDP_APPLIANCE_VLAN_TYPE 1973 1974 A byte containing the id of the VLAN. 1975 1976- Status LED: CONFIG_LED_STATUS 1977 1978 Several configurations allow to display the current 1979 status using a LED. For instance, the LED will blink 1980 fast while running U-Boot code, stop blinking as 1981 soon as a reply to a BOOTP request was received, and 1982 start blinking slow once the Linux kernel is running 1983 (supported by a status LED driver in the Linux 1984 kernel). Defining CONFIG_LED_STATUS enables this 1985 feature in U-Boot. 1986 1987 Additional options: 1988 1989 CONFIG_LED_STATUS_GPIO 1990 The status LED can be connected to a GPIO pin. 1991 In such cases, the gpio_led driver can be used as a 1992 status LED backend implementation. Define CONFIG_LED_STATUS_GPIO 1993 to include the gpio_led driver in the U-Boot binary. 1994 1995 CONFIG_GPIO_LED_INVERTED_TABLE 1996 Some GPIO connected LEDs may have inverted polarity in which 1997 case the GPIO high value corresponds to LED off state and 1998 GPIO low value corresponds to LED on state. 1999 In such cases CONFIG_GPIO_LED_INVERTED_TABLE may be defined 2000 with a list of GPIO LEDs that have inverted polarity. 2001 2002- CAN Support: CONFIG_CAN_DRIVER 2003 2004 Defining CONFIG_CAN_DRIVER enables CAN driver support 2005 on those systems that support this (optional) 2006 feature, like the TQM8xxL modules. 2007 2008- I2C Support: CONFIG_SYS_I2C 2009 2010 This enable the NEW i2c subsystem, and will allow you to use 2011 i2c commands at the u-boot command line (as long as you set 2012 CONFIG_CMD_I2C in CONFIG_COMMANDS) and communicate with i2c 2013 based realtime clock chips or other i2c devices. See 2014 common/cmd_i2c.c for a description of the command line 2015 interface. 2016 2017 ported i2c driver to the new framework: 2018 - drivers/i2c/soft_i2c.c: 2019 - activate first bus with CONFIG_SYS_I2C_SOFT define 2020 CONFIG_SYS_I2C_SOFT_SPEED and CONFIG_SYS_I2C_SOFT_SLAVE 2021 for defining speed and slave address 2022 - activate second bus with I2C_SOFT_DECLARATIONS2 define 2023 CONFIG_SYS_I2C_SOFT_SPEED_2 and CONFIG_SYS_I2C_SOFT_SLAVE_2 2024 for defining speed and slave address 2025 - activate third bus with I2C_SOFT_DECLARATIONS3 define 2026 CONFIG_SYS_I2C_SOFT_SPEED_3 and CONFIG_SYS_I2C_SOFT_SLAVE_3 2027 for defining speed and slave address 2028 - activate fourth bus with I2C_SOFT_DECLARATIONS4 define 2029 CONFIG_SYS_I2C_SOFT_SPEED_4 and CONFIG_SYS_I2C_SOFT_SLAVE_4 2030 for defining speed and slave address 2031 2032 - drivers/i2c/fsl_i2c.c: 2033 - activate i2c driver with CONFIG_SYS_I2C_FSL 2034 define CONFIG_SYS_FSL_I2C_OFFSET for setting the register 2035 offset CONFIG_SYS_FSL_I2C_SPEED for the i2c speed and 2036 CONFIG_SYS_FSL_I2C_SLAVE for the slave addr of the first 2037 bus. 2038 - If your board supports a second fsl i2c bus, define 2039 CONFIG_SYS_FSL_I2C2_OFFSET for the register offset 2040 CONFIG_SYS_FSL_I2C2_SPEED for the speed and 2041 CONFIG_SYS_FSL_I2C2_SLAVE for the slave address of the 2042 second bus. 2043 2044 - drivers/i2c/tegra_i2c.c: 2045 - activate this driver with CONFIG_SYS_I2C_TEGRA 2046 - This driver adds 4 i2c buses with a fix speed from 2047 100000 and the slave addr 0! 2048 2049 - drivers/i2c/ppc4xx_i2c.c 2050 - activate this driver with CONFIG_SYS_I2C_PPC4XX 2051 - CONFIG_SYS_I2C_PPC4XX_CH0 activate hardware channel 0 2052 - CONFIG_SYS_I2C_PPC4XX_CH1 activate hardware channel 1 2053 2054 - drivers/i2c/i2c_mxc.c 2055 - activate this driver with CONFIG_SYS_I2C_MXC 2056 - enable bus 1 with CONFIG_SYS_I2C_MXC_I2C1 2057 - enable bus 2 with CONFIG_SYS_I2C_MXC_I2C2 2058 - enable bus 3 with CONFIG_SYS_I2C_MXC_I2C3 2059 - enable bus 4 with CONFIG_SYS_I2C_MXC_I2C4 2060 - define speed for bus 1 with CONFIG_SYS_MXC_I2C1_SPEED 2061 - define slave for bus 1 with CONFIG_SYS_MXC_I2C1_SLAVE 2062 - define speed for bus 2 with CONFIG_SYS_MXC_I2C2_SPEED 2063 - define slave for bus 2 with CONFIG_SYS_MXC_I2C2_SLAVE 2064 - define speed for bus 3 with CONFIG_SYS_MXC_I2C3_SPEED 2065 - define slave for bus 3 with CONFIG_SYS_MXC_I2C3_SLAVE 2066 - define speed for bus 4 with CONFIG_SYS_MXC_I2C4_SPEED 2067 - define slave for bus 4 with CONFIG_SYS_MXC_I2C4_SLAVE 2068 If those defines are not set, default value is 100000 2069 for speed, and 0 for slave. 2070 2071 - drivers/i2c/rcar_i2c.c: 2072 - activate this driver with CONFIG_SYS_I2C_RCAR 2073 - This driver adds 4 i2c buses 2074 2075 - CONFIG_SYS_RCAR_I2C0_BASE for setting the register channel 0 2076 - CONFIG_SYS_RCAR_I2C0_SPEED for for the speed channel 0 2077 - CONFIG_SYS_RCAR_I2C1_BASE for setting the register channel 1 2078 - CONFIG_SYS_RCAR_I2C1_SPEED for for the speed channel 1 2079 - CONFIG_SYS_RCAR_I2C2_BASE for setting the register channel 2 2080 - CONFIG_SYS_RCAR_I2C2_SPEED for for the speed channel 2 2081 - CONFIG_SYS_RCAR_I2C3_BASE for setting the register channel 3 2082 - CONFIG_SYS_RCAR_I2C3_SPEED for for the speed channel 3 2083 - CONFIF_SYS_RCAR_I2C_NUM_CONTROLLERS for number of i2c buses 2084 2085 - drivers/i2c/sh_i2c.c: 2086 - activate this driver with CONFIG_SYS_I2C_SH 2087 - This driver adds from 2 to 5 i2c buses 2088 2089 - CONFIG_SYS_I2C_SH_BASE0 for setting the register channel 0 2090 - CONFIG_SYS_I2C_SH_SPEED0 for for the speed channel 0 2091 - CONFIG_SYS_I2C_SH_BASE1 for setting the register channel 1 2092 - CONFIG_SYS_I2C_SH_SPEED1 for for the speed channel 1 2093 - CONFIG_SYS_I2C_SH_BASE2 for setting the register channel 2 2094 - CONFIG_SYS_I2C_SH_SPEED2 for for the speed channel 2 2095 - CONFIG_SYS_I2C_SH_BASE3 for setting the register channel 3 2096 - CONFIG_SYS_I2C_SH_SPEED3 for for the speed channel 3 2097 - CONFIG_SYS_I2C_SH_BASE4 for setting the register channel 4 2098 - CONFIG_SYS_I2C_SH_SPEED4 for for the speed channel 4 2099 - CONFIG_SYS_I2C_SH_NUM_CONTROLLERS for number of i2c buses 2100 2101 - drivers/i2c/omap24xx_i2c.c 2102 - activate this driver with CONFIG_SYS_I2C_OMAP24XX 2103 - CONFIG_SYS_OMAP24_I2C_SPEED speed channel 0 2104 - CONFIG_SYS_OMAP24_I2C_SLAVE slave addr channel 0 2105 - CONFIG_SYS_OMAP24_I2C_SPEED1 speed channel 1 2106 - CONFIG_SYS_OMAP24_I2C_SLAVE1 slave addr channel 1 2107 - CONFIG_SYS_OMAP24_I2C_SPEED2 speed channel 2 2108 - CONFIG_SYS_OMAP24_I2C_SLAVE2 slave addr channel 2 2109 - CONFIG_SYS_OMAP24_I2C_SPEED3 speed channel 3 2110 - CONFIG_SYS_OMAP24_I2C_SLAVE3 slave addr channel 3 2111 - CONFIG_SYS_OMAP24_I2C_SPEED4 speed channel 4 2112 - CONFIG_SYS_OMAP24_I2C_SLAVE4 slave addr channel 4 2113 2114 - drivers/i2c/zynq_i2c.c 2115 - activate this driver with CONFIG_SYS_I2C_ZYNQ 2116 - set CONFIG_SYS_I2C_ZYNQ_SPEED for speed setting 2117 - set CONFIG_SYS_I2C_ZYNQ_SLAVE for slave addr 2118 2119 - drivers/i2c/s3c24x0_i2c.c: 2120 - activate this driver with CONFIG_SYS_I2C_S3C24X0 2121 - This driver adds i2c buses (11 for Exynos5250, Exynos5420 2122 9 i2c buses for Exynos4 and 1 for S3C24X0 SoCs from Samsung) 2123 with a fix speed from 100000 and the slave addr 0! 2124 2125 - drivers/i2c/ihs_i2c.c 2126 - activate this driver with CONFIG_SYS_I2C_IHS 2127 - CONFIG_SYS_I2C_IHS_CH0 activate hardware channel 0 2128 - CONFIG_SYS_I2C_IHS_SPEED_0 speed channel 0 2129 - CONFIG_SYS_I2C_IHS_SLAVE_0 slave addr channel 0 2130 - CONFIG_SYS_I2C_IHS_CH1 activate hardware channel 1 2131 - CONFIG_SYS_I2C_IHS_SPEED_1 speed channel 1 2132 - CONFIG_SYS_I2C_IHS_SLAVE_1 slave addr channel 1 2133 - CONFIG_SYS_I2C_IHS_CH2 activate hardware channel 2 2134 - CONFIG_SYS_I2C_IHS_SPEED_2 speed channel 2 2135 - CONFIG_SYS_I2C_IHS_SLAVE_2 slave addr channel 2 2136 - CONFIG_SYS_I2C_IHS_CH3 activate hardware channel 3 2137 - CONFIG_SYS_I2C_IHS_SPEED_3 speed channel 3 2138 - CONFIG_SYS_I2C_IHS_SLAVE_3 slave addr channel 3 2139 - activate dual channel with CONFIG_SYS_I2C_IHS_DUAL 2140 - CONFIG_SYS_I2C_IHS_SPEED_0_1 speed channel 0_1 2141 - CONFIG_SYS_I2C_IHS_SLAVE_0_1 slave addr channel 0_1 2142 - CONFIG_SYS_I2C_IHS_SPEED_1_1 speed channel 1_1 2143 - CONFIG_SYS_I2C_IHS_SLAVE_1_1 slave addr channel 1_1 2144 - CONFIG_SYS_I2C_IHS_SPEED_2_1 speed channel 2_1 2145 - CONFIG_SYS_I2C_IHS_SLAVE_2_1 slave addr channel 2_1 2146 - CONFIG_SYS_I2C_IHS_SPEED_3_1 speed channel 3_1 2147 - CONFIG_SYS_I2C_IHS_SLAVE_3_1 slave addr channel 3_1 2148 2149 additional defines: 2150 2151 CONFIG_SYS_NUM_I2C_BUSES 2152 Hold the number of i2c buses you want to use. 2153 2154 CONFIG_SYS_I2C_DIRECT_BUS 2155 define this, if you don't use i2c muxes on your hardware. 2156 if CONFIG_SYS_I2C_MAX_HOPS is not defined or == 0 you can 2157 omit this define. 2158 2159 CONFIG_SYS_I2C_MAX_HOPS 2160 define how many muxes are maximal consecutively connected 2161 on one i2c bus. If you not use i2c muxes, omit this 2162 define. 2163 2164 CONFIG_SYS_I2C_BUSES 2165 hold a list of buses you want to use, only used if 2166 CONFIG_SYS_I2C_DIRECT_BUS is not defined, for example 2167 a board with CONFIG_SYS_I2C_MAX_HOPS = 1 and 2168 CONFIG_SYS_NUM_I2C_BUSES = 9: 2169 2170 CONFIG_SYS_I2C_BUSES {{0, {I2C_NULL_HOP}}, \ 2171 {0, {{I2C_MUX_PCA9547, 0x70, 1}}}, \ 2172 {0, {{I2C_MUX_PCA9547, 0x70, 2}}}, \ 2173 {0, {{I2C_MUX_PCA9547, 0x70, 3}}}, \ 2174 {0, {{I2C_MUX_PCA9547, 0x70, 4}}}, \ 2175 {0, {{I2C_MUX_PCA9547, 0x70, 5}}}, \ 2176 {1, {I2C_NULL_HOP}}, \ 2177 {1, {{I2C_MUX_PCA9544, 0x72, 1}}}, \ 2178 {1, {{I2C_MUX_PCA9544, 0x72, 2}}}, \ 2179 } 2180 2181 which defines 2182 bus 0 on adapter 0 without a mux 2183 bus 1 on adapter 0 with a PCA9547 on address 0x70 port 1 2184 bus 2 on adapter 0 with a PCA9547 on address 0x70 port 2 2185 bus 3 on adapter 0 with a PCA9547 on address 0x70 port 3 2186 bus 4 on adapter 0 with a PCA9547 on address 0x70 port 4 2187 bus 5 on adapter 0 with a PCA9547 on address 0x70 port 5 2188 bus 6 on adapter 1 without a mux 2189 bus 7 on adapter 1 with a PCA9544 on address 0x72 port 1 2190 bus 8 on adapter 1 with a PCA9544 on address 0x72 port 2 2191 2192 If you do not have i2c muxes on your board, omit this define. 2193 2194- Legacy I2C Support: 2195 If you use the software i2c interface (CONFIG_SYS_I2C_SOFT) 2196 then the following macros need to be defined (examples are 2197 from include/configs/lwmon.h): 2198 2199 I2C_INIT 2200 2201 (Optional). Any commands necessary to enable the I2C 2202 controller or configure ports. 2203 2204 eg: #define I2C_INIT (immr->im_cpm.cp_pbdir |= PB_SCL) 2205 2206 I2C_PORT 2207 2208 (Only for MPC8260 CPU). The I/O port to use (the code 2209 assumes both bits are on the same port). Valid values 2210 are 0..3 for ports A..D. 2211 2212 I2C_ACTIVE 2213 2214 The code necessary to make the I2C data line active 2215 (driven). If the data line is open collector, this 2216 define can be null. 2217 2218 eg: #define I2C_ACTIVE (immr->im_cpm.cp_pbdir |= PB_SDA) 2219 2220 I2C_TRISTATE 2221 2222 The code necessary to make the I2C data line tri-stated 2223 (inactive). If the data line is open collector, this 2224 define can be null. 2225 2226 eg: #define I2C_TRISTATE (immr->im_cpm.cp_pbdir &= ~PB_SDA) 2227 2228 I2C_READ 2229 2230 Code that returns true if the I2C data line is high, 2231 false if it is low. 2232 2233 eg: #define I2C_READ ((immr->im_cpm.cp_pbdat & PB_SDA) != 0) 2234 2235 I2C_SDA(bit) 2236 2237 If <bit> is true, sets the I2C data line high. If it 2238 is false, it clears it (low). 2239 2240 eg: #define I2C_SDA(bit) \ 2241 if(bit) immr->im_cpm.cp_pbdat |= PB_SDA; \ 2242 else immr->im_cpm.cp_pbdat &= ~PB_SDA 2243 2244 I2C_SCL(bit) 2245 2246 If <bit> is true, sets the I2C clock line high. If it 2247 is false, it clears it (low). 2248 2249 eg: #define I2C_SCL(bit) \ 2250 if(bit) immr->im_cpm.cp_pbdat |= PB_SCL; \ 2251 else immr->im_cpm.cp_pbdat &= ~PB_SCL 2252 2253 I2C_DELAY 2254 2255 This delay is invoked four times per clock cycle so this 2256 controls the rate of data transfer. The data rate thus 2257 is 1 / (I2C_DELAY * 4). Often defined to be something 2258 like: 2259 2260 #define I2C_DELAY udelay(2) 2261 2262 CONFIG_SOFT_I2C_GPIO_SCL / CONFIG_SOFT_I2C_GPIO_SDA 2263 2264 If your arch supports the generic GPIO framework (asm/gpio.h), 2265 then you may alternatively define the two GPIOs that are to be 2266 used as SCL / SDA. Any of the previous I2C_xxx macros will 2267 have GPIO-based defaults assigned to them as appropriate. 2268 2269 You should define these to the GPIO value as given directly to 2270 the generic GPIO functions. 2271 2272 CONFIG_SYS_I2C_INIT_BOARD 2273 2274 When a board is reset during an i2c bus transfer 2275 chips might think that the current transfer is still 2276 in progress. On some boards it is possible to access 2277 the i2c SCLK line directly, either by using the 2278 processor pin as a GPIO or by having a second pin 2279 connected to the bus. If this option is defined a 2280 custom i2c_init_board() routine in boards/xxx/board.c 2281 is run early in the boot sequence. 2282 2283 CONFIG_I2C_MULTI_BUS 2284 2285 This option allows the use of multiple I2C buses, each of which 2286 must have a controller. At any point in time, only one bus is 2287 active. To switch to a different bus, use the 'i2c dev' command. 2288 Note that bus numbering is zero-based. 2289 2290 CONFIG_SYS_I2C_NOPROBES 2291 2292 This option specifies a list of I2C devices that will be skipped 2293 when the 'i2c probe' command is issued. If CONFIG_I2C_MULTI_BUS 2294 is set, specify a list of bus-device pairs. Otherwise, specify 2295 a 1D array of device addresses 2296 2297 e.g. 2298 #undef CONFIG_I2C_MULTI_BUS 2299 #define CONFIG_SYS_I2C_NOPROBES {0x50,0x68} 2300 2301 will skip addresses 0x50 and 0x68 on a board with one I2C bus 2302 2303 #define CONFIG_I2C_MULTI_BUS 2304 #define CONFIG_SYS_I2C_NOPROBES {{0,0x50},{0,0x68},{1,0x54}} 2305 2306 will skip addresses 0x50 and 0x68 on bus 0 and address 0x54 on bus 1 2307 2308 CONFIG_SYS_SPD_BUS_NUM 2309 2310 If defined, then this indicates the I2C bus number for DDR SPD. 2311 If not defined, then U-Boot assumes that SPD is on I2C bus 0. 2312 2313 CONFIG_SYS_RTC_BUS_NUM 2314 2315 If defined, then this indicates the I2C bus number for the RTC. 2316 If not defined, then U-Boot assumes that RTC is on I2C bus 0. 2317 2318 CONFIG_SOFT_I2C_READ_REPEATED_START 2319 2320 defining this will force the i2c_read() function in 2321 the soft_i2c driver to perform an I2C repeated start 2322 between writing the address pointer and reading the 2323 data. If this define is omitted the default behaviour 2324 of doing a stop-start sequence will be used. Most I2C 2325 devices can use either method, but some require one or 2326 the other. 2327 2328- SPI Support: CONFIG_SPI 2329 2330 Enables SPI driver (so far only tested with 2331 SPI EEPROM, also an instance works with Crystal A/D and 2332 D/As on the SACSng board) 2333 2334 CONFIG_SH_SPI 2335 2336 Enables the driver for SPI controller on SuperH. Currently 2337 only SH7757 is supported. 2338 2339 CONFIG_SOFT_SPI 2340 2341 Enables a software (bit-bang) SPI driver rather than 2342 using hardware support. This is a general purpose 2343 driver that only requires three general I/O port pins 2344 (two outputs, one input) to function. If this is 2345 defined, the board configuration must define several 2346 SPI configuration items (port pins to use, etc). For 2347 an example, see include/configs/sacsng.h. 2348 2349 CONFIG_HARD_SPI 2350 2351 Enables a hardware SPI driver for general-purpose reads 2352 and writes. As with CONFIG_SOFT_SPI, the board configuration 2353 must define a list of chip-select function pointers. 2354 Currently supported on some MPC8xxx processors. For an 2355 example, see include/configs/mpc8349emds.h. 2356 2357 CONFIG_MXC_SPI 2358 2359 Enables the driver for the SPI controllers on i.MX and MXC 2360 SoCs. Currently i.MX31/35/51 are supported. 2361 2362 CONFIG_SYS_SPI_MXC_WAIT 2363 Timeout for waiting until spi transfer completed. 2364 default: (CONFIG_SYS_HZ/100) /* 10 ms */ 2365 2366- FPGA Support: CONFIG_FPGA 2367 2368 Enables FPGA subsystem. 2369 2370 CONFIG_FPGA_<vendor> 2371 2372 Enables support for specific chip vendors. 2373 (ALTERA, XILINX) 2374 2375 CONFIG_FPGA_<family> 2376 2377 Enables support for FPGA family. 2378 (SPARTAN2, SPARTAN3, VIRTEX2, CYCLONE2, ACEX1K, ACEX) 2379 2380 CONFIG_FPGA_COUNT 2381 2382 Specify the number of FPGA devices to support. 2383 2384 CONFIG_SYS_FPGA_PROG_FEEDBACK 2385 2386 Enable printing of hash marks during FPGA configuration. 2387 2388 CONFIG_SYS_FPGA_CHECK_BUSY 2389 2390 Enable checks on FPGA configuration interface busy 2391 status by the configuration function. This option 2392 will require a board or device specific function to 2393 be written. 2394 2395 CONFIG_FPGA_DELAY 2396 2397 If defined, a function that provides delays in the FPGA 2398 configuration driver. 2399 2400 CONFIG_SYS_FPGA_CHECK_CTRLC 2401 Allow Control-C to interrupt FPGA configuration 2402 2403 CONFIG_SYS_FPGA_CHECK_ERROR 2404 2405 Check for configuration errors during FPGA bitfile 2406 loading. For example, abort during Virtex II 2407 configuration if the INIT_B line goes low (which 2408 indicated a CRC error). 2409 2410 CONFIG_SYS_FPGA_WAIT_INIT 2411 2412 Maximum time to wait for the INIT_B line to de-assert 2413 after PROB_B has been de-asserted during a Virtex II 2414 FPGA configuration sequence. The default time is 500 2415 ms. 2416 2417 CONFIG_SYS_FPGA_WAIT_BUSY 2418 2419 Maximum time to wait for BUSY to de-assert during 2420 Virtex II FPGA configuration. The default is 5 ms. 2421 2422 CONFIG_SYS_FPGA_WAIT_CONFIG 2423 2424 Time to wait after FPGA configuration. The default is 2425 200 ms. 2426 2427- Configuration Management: 2428 CONFIG_BUILD_TARGET 2429 2430 Some SoCs need special image types (e.g. U-Boot binary 2431 with a special header) as build targets. By defining 2432 CONFIG_BUILD_TARGET in the SoC / board header, this 2433 special image will be automatically built upon calling 2434 make / buildman. 2435 2436 CONFIG_IDENT_STRING 2437 2438 If defined, this string will be added to the U-Boot 2439 version information (U_BOOT_VERSION) 2440 2441- Vendor Parameter Protection: 2442 2443 U-Boot considers the values of the environment 2444 variables "serial#" (Board Serial Number) and 2445 "ethaddr" (Ethernet Address) to be parameters that 2446 are set once by the board vendor / manufacturer, and 2447 protects these variables from casual modification by 2448 the user. Once set, these variables are read-only, 2449 and write or delete attempts are rejected. You can 2450 change this behaviour: 2451 2452 If CONFIG_ENV_OVERWRITE is #defined in your config 2453 file, the write protection for vendor parameters is 2454 completely disabled. Anybody can change or delete 2455 these parameters. 2456 2457 Alternatively, if you define _both_ an ethaddr in the 2458 default env _and_ CONFIG_OVERWRITE_ETHADDR_ONCE, a default 2459 Ethernet address is installed in the environment, 2460 which can be changed exactly ONCE by the user. [The 2461 serial# is unaffected by this, i. e. it remains 2462 read-only.] 2463 2464 The same can be accomplished in a more flexible way 2465 for any variable by configuring the type of access 2466 to allow for those variables in the ".flags" variable 2467 or define CONFIG_ENV_FLAGS_LIST_STATIC. 2468 2469- Protected RAM: 2470 CONFIG_PRAM 2471 2472 Define this variable to enable the reservation of 2473 "protected RAM", i. e. RAM which is not overwritten 2474 by U-Boot. Define CONFIG_PRAM to hold the number of 2475 kB you want to reserve for pRAM. You can overwrite 2476 this default value by defining an environment 2477 variable "pram" to the number of kB you want to 2478 reserve. Note that the board info structure will 2479 still show the full amount of RAM. If pRAM is 2480 reserved, a new environment variable "mem" will 2481 automatically be defined to hold the amount of 2482 remaining RAM in a form that can be passed as boot 2483 argument to Linux, for instance like that: 2484 2485 setenv bootargs ... mem=\${mem} 2486 saveenv 2487 2488 This way you can tell Linux not to use this memory, 2489 either, which results in a memory region that will 2490 not be affected by reboots. 2491 2492 *WARNING* If your board configuration uses automatic 2493 detection of the RAM size, you must make sure that 2494 this memory test is non-destructive. So far, the 2495 following board configurations are known to be 2496 "pRAM-clean": 2497 2498 IVMS8, IVML24, SPD8xx, TQM8xxL, 2499 HERMES, IP860, RPXlite, LWMON, 2500 FLAGADM, TQM8260 2501 2502- Access to physical memory region (> 4GB) 2503 Some basic support is provided for operations on memory not 2504 normally accessible to U-Boot - e.g. some architectures 2505 support access to more than 4GB of memory on 32-bit 2506 machines using physical address extension or similar. 2507 Define CONFIG_PHYSMEM to access this basic support, which 2508 currently only supports clearing the memory. 2509 2510- Error Recovery: 2511 CONFIG_PANIC_HANG 2512 2513 Define this variable to stop the system in case of a 2514 fatal error, so that you have to reset it manually. 2515 This is probably NOT a good idea for an embedded 2516 system where you want the system to reboot 2517 automatically as fast as possible, but it may be 2518 useful during development since you can try to debug 2519 the conditions that lead to the situation. 2520 2521 CONFIG_NET_RETRY_COUNT 2522 2523 This variable defines the number of retries for 2524 network operations like ARP, RARP, TFTP, or BOOTP 2525 before giving up the operation. If not defined, a 2526 default value of 5 is used. 2527 2528 CONFIG_ARP_TIMEOUT 2529 2530 Timeout waiting for an ARP reply in milliseconds. 2531 2532 CONFIG_NFS_TIMEOUT 2533 2534 Timeout in milliseconds used in NFS protocol. 2535 If you encounter "ERROR: Cannot umount" in nfs command, 2536 try longer timeout such as 2537 #define CONFIG_NFS_TIMEOUT 10000UL 2538 2539- Command Interpreter: 2540 CONFIG_AUTO_COMPLETE 2541 2542 Enable auto completion of commands using TAB. 2543 2544 CONFIG_SYS_PROMPT_HUSH_PS2 2545 2546 This defines the secondary prompt string, which is 2547 printed when the command interpreter needs more input 2548 to complete a command. Usually "> ". 2549 2550 Note: 2551 2552 In the current implementation, the local variables 2553 space and global environment variables space are 2554 separated. Local variables are those you define by 2555 simply typing `name=value'. To access a local 2556 variable later on, you have write `$name' or 2557 `${name}'; to execute the contents of a variable 2558 directly type `$name' at the command prompt. 2559 2560 Global environment variables are those you use 2561 setenv/printenv to work with. To run a command stored 2562 in such a variable, you need to use the run command, 2563 and you must not use the '$' sign to access them. 2564 2565 To store commands and special characters in a 2566 variable, please use double quotation marks 2567 surrounding the whole text of the variable, instead 2568 of the backslashes before semicolons and special 2569 symbols. 2570 2571- Command Line Editing and History: 2572 CONFIG_CMDLINE_EDITING 2573 2574 Enable editing and History functions for interactive 2575 command line input operations 2576 2577- Command Line PS1/PS2 support: 2578 CONFIG_CMDLINE_PS_SUPPORT 2579 2580 Enable support for changing the command prompt string 2581 at run-time. Only static string is supported so far. 2582 The string is obtained from environment variables PS1 2583 and PS2. 2584 2585- Default Environment: 2586 CONFIG_EXTRA_ENV_SETTINGS 2587 2588 Define this to contain any number of null terminated 2589 strings (variable = value pairs) that will be part of 2590 the default environment compiled into the boot image. 2591 2592 For example, place something like this in your 2593 board's config file: 2594 2595 #define CONFIG_EXTRA_ENV_SETTINGS \ 2596 "myvar1=value1\0" \ 2597 "myvar2=value2\0" 2598 2599 Warning: This method is based on knowledge about the 2600 internal format how the environment is stored by the 2601 U-Boot code. This is NOT an official, exported 2602 interface! Although it is unlikely that this format 2603 will change soon, there is no guarantee either. 2604 You better know what you are doing here. 2605 2606 Note: overly (ab)use of the default environment is 2607 discouraged. Make sure to check other ways to preset 2608 the environment like the "source" command or the 2609 boot command first. 2610 2611 CONFIG_ENV_VARS_UBOOT_CONFIG 2612 2613 Define this in order to add variables describing the 2614 U-Boot build configuration to the default environment. 2615 These will be named arch, cpu, board, vendor, and soc. 2616 2617 Enabling this option will cause the following to be defined: 2618 2619 - CONFIG_SYS_ARCH 2620 - CONFIG_SYS_CPU 2621 - CONFIG_SYS_BOARD 2622 - CONFIG_SYS_VENDOR 2623 - CONFIG_SYS_SOC 2624 2625 CONFIG_ENV_VARS_UBOOT_RUNTIME_CONFIG 2626 2627 Define this in order to add variables describing certain 2628 run-time determined information about the hardware to the 2629 environment. These will be named board_name, board_rev. 2630 2631 CONFIG_DELAY_ENVIRONMENT 2632 2633 Normally the environment is loaded when the board is 2634 initialised so that it is available to U-Boot. This inhibits 2635 that so that the environment is not available until 2636 explicitly loaded later by U-Boot code. With CONFIG_OF_CONTROL 2637 this is instead controlled by the value of 2638 /config/load-environment. 2639 2640- DataFlash Support: 2641 CONFIG_HAS_DATAFLASH 2642 2643 Defining this option enables DataFlash features and 2644 allows to read/write in Dataflash via the standard 2645 commands cp, md... 2646 2647- Serial Flash support 2648 CONFIG_CMD_SF 2649 2650 Defining this option enables SPI flash commands 2651 'sf probe/read/write/erase/update'. 2652 2653 Usage requires an initial 'probe' to define the serial 2654 flash parameters, followed by read/write/erase/update 2655 commands. 2656 2657 The following defaults may be provided by the platform 2658 to handle the common case when only a single serial 2659 flash is present on the system. 2660 2661 CONFIG_SF_DEFAULT_BUS Bus identifier 2662 CONFIG_SF_DEFAULT_CS Chip-select 2663 CONFIG_SF_DEFAULT_MODE (see include/spi.h) 2664 CONFIG_SF_DEFAULT_SPEED in Hz 2665 2666 CONFIG_CMD_SF_TEST 2667 2668 Define this option to include a destructive SPI flash 2669 test ('sf test'). 2670 2671 CONFIG_SF_DUAL_FLASH Dual flash memories 2672 2673 Define this option to use dual flash support where two flash 2674 memories can be connected with a given cs line. 2675 Currently Xilinx Zynq qspi supports these type of connections. 2676 2677- SystemACE Support: 2678 CONFIG_SYSTEMACE 2679 2680 Adding this option adds support for Xilinx SystemACE 2681 chips attached via some sort of local bus. The address 2682 of the chip must also be defined in the 2683 CONFIG_SYS_SYSTEMACE_BASE macro. For example: 2684 2685 #define CONFIG_SYSTEMACE 2686 #define CONFIG_SYS_SYSTEMACE_BASE 0xf0000000 2687 2688 When SystemACE support is added, the "ace" device type 2689 becomes available to the fat commands, i.e. fatls. 2690 2691- TFTP Fixed UDP Port: 2692 CONFIG_TFTP_PORT 2693 2694 If this is defined, the environment variable tftpsrcp 2695 is used to supply the TFTP UDP source port value. 2696 If tftpsrcp isn't defined, the normal pseudo-random port 2697 number generator is used. 2698 2699 Also, the environment variable tftpdstp is used to supply 2700 the TFTP UDP destination port value. If tftpdstp isn't 2701 defined, the normal port 69 is used. 2702 2703 The purpose for tftpsrcp is to allow a TFTP server to 2704 blindly start the TFTP transfer using the pre-configured 2705 target IP address and UDP port. This has the effect of 2706 "punching through" the (Windows XP) firewall, allowing 2707 the remainder of the TFTP transfer to proceed normally. 2708 A better solution is to properly configure the firewall, 2709 but sometimes that is not allowed. 2710 2711- Hashing support: 2712 CONFIG_HASH_VERIFY 2713 2714 Enable the hash verify command (hash -v). This adds to code 2715 size a little. 2716 2717 Note: There is also a sha1sum command, which should perhaps 2718 be deprecated in favour of 'hash sha1'. 2719 2720- Freescale i.MX specific commands: 2721 CONFIG_CMD_HDMIDETECT 2722 This enables 'hdmidet' command which returns true if an 2723 HDMI monitor is detected. This command is i.MX 6 specific. 2724 2725- bootcount support: 2726 CONFIG_BOOTCOUNT_LIMIT 2727 2728 This enables the bootcounter support, see: 2729 http://www.denx.de/wiki/DULG/UBootBootCountLimit 2730 2731 CONFIG_AT91SAM9XE 2732 enable special bootcounter support on at91sam9xe based boards. 2733 CONFIG_SOC_DA8XX 2734 enable special bootcounter support on da850 based boards. 2735 CONFIG_BOOTCOUNT_RAM 2736 enable support for the bootcounter in RAM 2737 CONFIG_BOOTCOUNT_I2C 2738 enable support for the bootcounter on an i2c (like RTC) device. 2739 CONFIG_SYS_I2C_RTC_ADDR = i2c chip address 2740 CONFIG_SYS_BOOTCOUNT_ADDR = i2c addr which is used for 2741 the bootcounter. 2742 CONFIG_BOOTCOUNT_ALEN = address len 2743 2744- Show boot progress: 2745 CONFIG_SHOW_BOOT_PROGRESS 2746 2747 Defining this option allows to add some board- 2748 specific code (calling a user-provided function 2749 "show_boot_progress(int)") that enables you to show 2750 the system's boot progress on some display (for 2751 example, some LED's) on your board. At the moment, 2752 the following checkpoints are implemented: 2753 2754 2755Legacy uImage format: 2756 2757 Arg Where When 2758 1 common/cmd_bootm.c before attempting to boot an image 2759 -1 common/cmd_bootm.c Image header has bad magic number 2760 2 common/cmd_bootm.c Image header has correct magic number 2761 -2 common/cmd_bootm.c Image header has bad checksum 2762 3 common/cmd_bootm.c Image header has correct checksum 2763 -3 common/cmd_bootm.c Image data has bad checksum 2764 4 common/cmd_bootm.c Image data has correct checksum 2765 -4 common/cmd_bootm.c Image is for unsupported architecture 2766 5 common/cmd_bootm.c Architecture check OK 2767 -5 common/cmd_bootm.c Wrong Image Type (not kernel, multi) 2768 6 common/cmd_bootm.c Image Type check OK 2769 -6 common/cmd_bootm.c gunzip uncompression error 2770 -7 common/cmd_bootm.c Unimplemented compression type 2771 7 common/cmd_bootm.c Uncompression OK 2772 8 common/cmd_bootm.c No uncompress/copy overwrite error 2773 -9 common/cmd_bootm.c Unsupported OS (not Linux, BSD, VxWorks, QNX) 2774 2775 9 common/image.c Start initial ramdisk verification 2776 -10 common/image.c Ramdisk header has bad magic number 2777 -11 common/image.c Ramdisk header has bad checksum 2778 10 common/image.c Ramdisk header is OK 2779 -12 common/image.c Ramdisk data has bad checksum 2780 11 common/image.c Ramdisk data has correct checksum 2781 12 common/image.c Ramdisk verification complete, start loading 2782 -13 common/image.c Wrong Image Type (not PPC Linux ramdisk) 2783 13 common/image.c Start multifile image verification 2784 14 common/image.c No initial ramdisk, no multifile, continue. 2785 2786 15 arch/<arch>/lib/bootm.c All preparation done, transferring control to OS 2787 2788 -30 arch/powerpc/lib/board.c Fatal error, hang the system 2789 -31 post/post.c POST test failed, detected by post_output_backlog() 2790 -32 post/post.c POST test failed, detected by post_run_single() 2791 2792 34 common/cmd_doc.c before loading a Image from a DOC device 2793 -35 common/cmd_doc.c Bad usage of "doc" command 2794 35 common/cmd_doc.c correct usage of "doc" command 2795 -36 common/cmd_doc.c No boot device 2796 36 common/cmd_doc.c correct boot device 2797 -37 common/cmd_doc.c Unknown Chip ID on boot device 2798 37 common/cmd_doc.c correct chip ID found, device available 2799 -38 common/cmd_doc.c Read Error on boot device 2800 38 common/cmd_doc.c reading Image header from DOC device OK 2801 -39 common/cmd_doc.c Image header has bad magic number 2802 39 common/cmd_doc.c Image header has correct magic number 2803 -40 common/cmd_doc.c Error reading Image from DOC device 2804 40 common/cmd_doc.c Image header has correct magic number 2805 41 common/cmd_ide.c before loading a Image from a IDE device 2806 -42 common/cmd_ide.c Bad usage of "ide" command 2807 42 common/cmd_ide.c correct usage of "ide" command 2808 -43 common/cmd_ide.c No boot device 2809 43 common/cmd_ide.c boot device found 2810 -44 common/cmd_ide.c Device not available 2811 44 common/cmd_ide.c Device available 2812 -45 common/cmd_ide.c wrong partition selected 2813 45 common/cmd_ide.c partition selected 2814 -46 common/cmd_ide.c Unknown partition table 2815 46 common/cmd_ide.c valid partition table found 2816 -47 common/cmd_ide.c Invalid partition type 2817 47 common/cmd_ide.c correct partition type 2818 -48 common/cmd_ide.c Error reading Image Header on boot device 2819 48 common/cmd_ide.c reading Image Header from IDE device OK 2820 -49 common/cmd_ide.c Image header has bad magic number 2821 49 common/cmd_ide.c Image header has correct magic number 2822 -50 common/cmd_ide.c Image header has bad checksum 2823 50 common/cmd_ide.c Image header has correct checksum 2824 -51 common/cmd_ide.c Error reading Image from IDE device 2825 51 common/cmd_ide.c reading Image from IDE device OK 2826 52 common/cmd_nand.c before loading a Image from a NAND device 2827 -53 common/cmd_nand.c Bad usage of "nand" command 2828 53 common/cmd_nand.c correct usage of "nand" command 2829 -54 common/cmd_nand.c No boot device 2830 54 common/cmd_nand.c boot device found 2831 -55 common/cmd_nand.c Unknown Chip ID on boot device 2832 55 common/cmd_nand.c correct chip ID found, device available 2833 -56 common/cmd_nand.c Error reading Image Header on boot device 2834 56 common/cmd_nand.c reading Image Header from NAND device OK 2835 -57 common/cmd_nand.c Image header has bad magic number 2836 57 common/cmd_nand.c Image header has correct magic number 2837 -58 common/cmd_nand.c Error reading Image from NAND device 2838 58 common/cmd_nand.c reading Image from NAND device OK 2839 2840 -60 common/env_common.c Environment has a bad CRC, using default 2841 2842 64 net/eth.c starting with Ethernet configuration. 2843 -64 net/eth.c no Ethernet found. 2844 65 net/eth.c Ethernet found. 2845 2846 -80 common/cmd_net.c usage wrong 2847 80 common/cmd_net.c before calling net_loop() 2848 -81 common/cmd_net.c some error in net_loop() occurred 2849 81 common/cmd_net.c net_loop() back without error 2850 -82 common/cmd_net.c size == 0 (File with size 0 loaded) 2851 82 common/cmd_net.c trying automatic boot 2852 83 common/cmd_net.c running "source" command 2853 -83 common/cmd_net.c some error in automatic boot or "source" command 2854 84 common/cmd_net.c end without errors 2855 2856FIT uImage format: 2857 2858 Arg Where When 2859 100 common/cmd_bootm.c Kernel FIT Image has correct format 2860 -100 common/cmd_bootm.c Kernel FIT Image has incorrect format 2861 101 common/cmd_bootm.c No Kernel subimage unit name, using configuration 2862 -101 common/cmd_bootm.c Can't get configuration for kernel subimage 2863 102 common/cmd_bootm.c Kernel unit name specified 2864 -103 common/cmd_bootm.c Can't get kernel subimage node offset 2865 103 common/cmd_bootm.c Found configuration node 2866 104 common/cmd_bootm.c Got kernel subimage node offset 2867 -104 common/cmd_bootm.c Kernel subimage hash verification failed 2868 105 common/cmd_bootm.c Kernel subimage hash verification OK 2869 -105 common/cmd_bootm.c Kernel subimage is for unsupported architecture 2870 106 common/cmd_bootm.c Architecture check OK 2871 -106 common/cmd_bootm.c Kernel subimage has wrong type 2872 107 common/cmd_bootm.c Kernel subimage type OK 2873 -107 common/cmd_bootm.c Can't get kernel subimage data/size 2874 108 common/cmd_bootm.c Got kernel subimage data/size 2875 -108 common/cmd_bootm.c Wrong image type (not legacy, FIT) 2876 -109 common/cmd_bootm.c Can't get kernel subimage type 2877 -110 common/cmd_bootm.c Can't get kernel subimage comp 2878 -111 common/cmd_bootm.c Can't get kernel subimage os 2879 -112 common/cmd_bootm.c Can't get kernel subimage load address 2880 -113 common/cmd_bootm.c Image uncompress/copy overwrite error 2881 2882 120 common/image.c Start initial ramdisk verification 2883 -120 common/image.c Ramdisk FIT image has incorrect format 2884 121 common/image.c Ramdisk FIT image has correct format 2885 122 common/image.c No ramdisk subimage unit name, using configuration 2886 -122 common/image.c Can't get configuration for ramdisk subimage 2887 123 common/image.c Ramdisk unit name specified 2888 -124 common/image.c Can't get ramdisk subimage node offset 2889 125 common/image.c Got ramdisk subimage node offset 2890 -125 common/image.c Ramdisk subimage hash verification failed 2891 126 common/image.c Ramdisk subimage hash verification OK 2892 -126 common/image.c Ramdisk subimage for unsupported architecture 2893 127 common/image.c Architecture check OK 2894 -127 common/image.c Can't get ramdisk subimage data/size 2895 128 common/image.c Got ramdisk subimage data/size 2896 129 common/image.c Can't get ramdisk load address 2897 -129 common/image.c Got ramdisk load address 2898 2899 -130 common/cmd_doc.c Incorrect FIT image format 2900 131 common/cmd_doc.c FIT image format OK 2901 2902 -140 common/cmd_ide.c Incorrect FIT image format 2903 141 common/cmd_ide.c FIT image format OK 2904 2905 -150 common/cmd_nand.c Incorrect FIT image format 2906 151 common/cmd_nand.c FIT image format OK 2907 2908- legacy image format: 2909 CONFIG_IMAGE_FORMAT_LEGACY 2910 enables the legacy image format support in U-Boot. 2911 2912 Default: 2913 enabled if CONFIG_FIT_SIGNATURE is not defined. 2914 2915 CONFIG_DISABLE_IMAGE_LEGACY 2916 disable the legacy image format 2917 2918 This define is introduced, as the legacy image format is 2919 enabled per default for backward compatibility. 2920 2921- Standalone program support: 2922 CONFIG_STANDALONE_LOAD_ADDR 2923 2924 This option defines a board specific value for the 2925 address where standalone program gets loaded, thus 2926 overwriting the architecture dependent default 2927 settings. 2928 2929- Frame Buffer Address: 2930 CONFIG_FB_ADDR 2931 2932 Define CONFIG_FB_ADDR if you want to use specific 2933 address for frame buffer. This is typically the case 2934 when using a graphics controller has separate video 2935 memory. U-Boot will then place the frame buffer at 2936 the given address instead of dynamically reserving it 2937 in system RAM by calling lcd_setmem(), which grabs 2938 the memory for the frame buffer depending on the 2939 configured panel size. 2940 2941 Please see board_init_f function. 2942 2943- Automatic software updates via TFTP server 2944 CONFIG_UPDATE_TFTP 2945 CONFIG_UPDATE_TFTP_CNT_MAX 2946 CONFIG_UPDATE_TFTP_MSEC_MAX 2947 2948 These options enable and control the auto-update feature; 2949 for a more detailed description refer to doc/README.update. 2950 2951- MTD Support (mtdparts command, UBI support) 2952 CONFIG_MTD_DEVICE 2953 2954 Adds the MTD device infrastructure from the Linux kernel. 2955 Needed for mtdparts command support. 2956 2957 CONFIG_MTD_PARTITIONS 2958 2959 Adds the MTD partitioning infrastructure from the Linux 2960 kernel. Needed for UBI support. 2961 2962- UBI support 2963 CONFIG_CMD_UBI 2964 2965 Adds commands for interacting with MTD partitions formatted 2966 with the UBI flash translation layer 2967 2968 Requires also defining CONFIG_RBTREE 2969 2970 CONFIG_UBI_SILENCE_MSG 2971 2972 Make the verbose messages from UBI stop printing. This leaves 2973 warnings and errors enabled. 2974 2975 2976 CONFIG_MTD_UBI_WL_THRESHOLD 2977 This parameter defines the maximum difference between the highest 2978 erase counter value and the lowest erase counter value of eraseblocks 2979 of UBI devices. When this threshold is exceeded, UBI starts performing 2980 wear leveling by means of moving data from eraseblock with low erase 2981 counter to eraseblocks with high erase counter. 2982 2983 The default value should be OK for SLC NAND flashes, NOR flashes and 2984 other flashes which have eraseblock life-cycle 100000 or more. 2985 However, in case of MLC NAND flashes which typically have eraseblock 2986 life-cycle less than 10000, the threshold should be lessened (e.g., 2987 to 128 or 256, although it does not have to be power of 2). 2988 2989 default: 4096 2990 2991 CONFIG_MTD_UBI_BEB_LIMIT 2992 This option specifies the maximum bad physical eraseblocks UBI 2993 expects on the MTD device (per 1024 eraseblocks). If the 2994 underlying flash does not admit of bad eraseblocks (e.g. NOR 2995 flash), this value is ignored. 2996 2997 NAND datasheets often specify the minimum and maximum NVM 2998 (Number of Valid Blocks) for the flashes' endurance lifetime. 2999 The maximum expected bad eraseblocks per 1024 eraseblocks 3000 then can be calculated as "1024 * (1 - MinNVB / MaxNVB)", 3001 which gives 20 for most NANDs (MaxNVB is basically the total 3002 count of eraseblocks on the chip). 3003 3004 To put it differently, if this value is 20, UBI will try to 3005 reserve about 1.9% of physical eraseblocks for bad blocks 3006 handling. And that will be 1.9% of eraseblocks on the entire 3007 NAND chip, not just the MTD partition UBI attaches. This means 3008 that if you have, say, a NAND flash chip admits maximum 40 bad 3009 eraseblocks, and it is split on two MTD partitions of the same 3010 size, UBI will reserve 40 eraseblocks when attaching a 3011 partition. 3012 3013 default: 20 3014 3015 CONFIG_MTD_UBI_FASTMAP 3016 Fastmap is a mechanism which allows attaching an UBI device 3017 in nearly constant time. Instead of scanning the whole MTD device it 3018 only has to locate a checkpoint (called fastmap) on the device. 3019 The on-flash fastmap contains all information needed to attach 3020 the device. Using fastmap makes only sense on large devices where 3021 attaching by scanning takes long. UBI will not automatically install 3022 a fastmap on old images, but you can set the UBI parameter 3023 CONFIG_MTD_UBI_FASTMAP_AUTOCONVERT to 1 if you want so. Please note 3024 that fastmap-enabled images are still usable with UBI implementations 3025 without fastmap support. On typical flash devices the whole fastmap 3026 fits into one PEB. UBI will reserve PEBs to hold two fastmaps. 3027 3028 CONFIG_MTD_UBI_FASTMAP_AUTOCONVERT 3029 Set this parameter to enable fastmap automatically on images 3030 without a fastmap. 3031 default: 0 3032 3033 CONFIG_MTD_UBI_FM_DEBUG 3034 Enable UBI fastmap debug 3035 default: 0 3036 3037- UBIFS support 3038 CONFIG_CMD_UBIFS 3039 3040 Adds commands for interacting with UBI volumes formatted as 3041 UBIFS. UBIFS is read-only in u-boot. 3042 3043 Requires UBI support as well as CONFIG_LZO 3044 3045 CONFIG_UBIFS_SILENCE_MSG 3046 3047 Make the verbose messages from UBIFS stop printing. This leaves 3048 warnings and errors enabled. 3049 3050- SPL framework 3051 CONFIG_SPL 3052 Enable building of SPL globally. 3053 3054 CONFIG_SPL_LDSCRIPT 3055 LDSCRIPT for linking the SPL binary. 3056 3057 CONFIG_SPL_MAX_FOOTPRINT 3058 Maximum size in memory allocated to the SPL, BSS included. 3059 When defined, the linker checks that the actual memory 3060 used by SPL from _start to __bss_end does not exceed it. 3061 CONFIG_SPL_MAX_FOOTPRINT and CONFIG_SPL_BSS_MAX_SIZE 3062 must not be both defined at the same time. 3063 3064 CONFIG_SPL_MAX_SIZE 3065 Maximum size of the SPL image (text, data, rodata, and 3066 linker lists sections), BSS excluded. 3067 When defined, the linker checks that the actual size does 3068 not exceed it. 3069 3070 CONFIG_SPL_TEXT_BASE 3071 TEXT_BASE for linking the SPL binary. 3072 3073 CONFIG_SPL_RELOC_TEXT_BASE 3074 Address to relocate to. If unspecified, this is equal to 3075 CONFIG_SPL_TEXT_BASE (i.e. no relocation is done). 3076 3077 CONFIG_SPL_BSS_START_ADDR 3078 Link address for the BSS within the SPL binary. 3079 3080 CONFIG_SPL_BSS_MAX_SIZE 3081 Maximum size in memory allocated to the SPL BSS. 3082 When defined, the linker checks that the actual memory used 3083 by SPL from __bss_start to __bss_end does not exceed it. 3084 CONFIG_SPL_MAX_FOOTPRINT and CONFIG_SPL_BSS_MAX_SIZE 3085 must not be both defined at the same time. 3086 3087 CONFIG_SPL_STACK 3088 Adress of the start of the stack SPL will use 3089 3090 CONFIG_SPL_PANIC_ON_RAW_IMAGE 3091 When defined, SPL will panic() if the image it has 3092 loaded does not have a signature. 3093 Defining this is useful when code which loads images 3094 in SPL cannot guarantee that absolutely all read errors 3095 will be caught. 3096 An example is the LPC32XX MLC NAND driver, which will 3097 consider that a completely unreadable NAND block is bad, 3098 and thus should be skipped silently. 3099 3100 CONFIG_SPL_RELOC_STACK 3101 Adress of the start of the stack SPL will use after 3102 relocation. If unspecified, this is equal to 3103 CONFIG_SPL_STACK. 3104 3105 CONFIG_SYS_SPL_MALLOC_START 3106 Starting address of the malloc pool used in SPL. 3107 When this option is set the full malloc is used in SPL and 3108 it is set up by spl_init() and before that, the simple malloc() 3109 can be used if CONFIG_SYS_MALLOC_F is defined. 3110 3111 CONFIG_SYS_SPL_MALLOC_SIZE 3112 The size of the malloc pool used in SPL. 3113 3114 CONFIG_SPL_FRAMEWORK 3115 Enable the SPL framework under common/. This framework 3116 supports MMC, NAND and YMODEM loading of U-Boot and NAND 3117 NAND loading of the Linux Kernel. 3118 3119 CONFIG_SPL_OS_BOOT 3120 Enable booting directly to an OS from SPL. 3121 See also: doc/README.falcon 3122 3123 CONFIG_SPL_DISPLAY_PRINT 3124 For ARM, enable an optional function to print more information 3125 about the running system. 3126 3127 CONFIG_SPL_INIT_MINIMAL 3128 Arch init code should be built for a very small image 3129 3130 CONFIG_SYS_MMCSD_RAW_MODE_U_BOOT_PARTITION 3131 Partition on the MMC to load U-Boot from when the MMC is being 3132 used in raw mode 3133 3134 CONFIG_SYS_MMCSD_RAW_MODE_KERNEL_SECTOR 3135 Sector to load kernel uImage from when MMC is being 3136 used in raw mode (for Falcon mode) 3137 3138 CONFIG_SYS_MMCSD_RAW_MODE_ARGS_SECTOR, 3139 CONFIG_SYS_MMCSD_RAW_MODE_ARGS_SECTORS 3140 Sector and number of sectors to load kernel argument 3141 parameters from when MMC is being used in raw mode 3142 (for falcon mode) 3143 3144 CONFIG_SYS_MMCSD_FS_BOOT_PARTITION 3145 Partition on the MMC to load U-Boot from when the MMC is being 3146 used in fs mode 3147 3148 CONFIG_SPL_FS_LOAD_PAYLOAD_NAME 3149 Filename to read to load U-Boot when reading from filesystem 3150 3151 CONFIG_SPL_FS_LOAD_KERNEL_NAME 3152 Filename to read to load kernel uImage when reading 3153 from filesystem (for Falcon mode) 3154 3155 CONFIG_SPL_FS_LOAD_ARGS_NAME 3156 Filename to read to load kernel argument parameters 3157 when reading from filesystem (for Falcon mode) 3158 3159 CONFIG_SPL_MPC83XX_WAIT_FOR_NAND 3160 Set this for NAND SPL on PPC mpc83xx targets, so that 3161 start.S waits for the rest of the SPL to load before 3162 continuing (the hardware starts execution after just 3163 loading the first page rather than the full 4K). 3164 3165 CONFIG_SPL_SKIP_RELOCATE 3166 Avoid SPL relocation 3167 3168 CONFIG_SPL_NAND_BASE 3169 Include nand_base.c in the SPL. Requires 3170 CONFIG_SPL_NAND_DRIVERS. 3171 3172 CONFIG_SPL_NAND_DRIVERS 3173 SPL uses normal NAND drivers, not minimal drivers. 3174 3175 CONFIG_SPL_NAND_ECC 3176 Include standard software ECC in the SPL 3177 3178 CONFIG_SPL_NAND_SIMPLE 3179 Support for NAND boot using simple NAND drivers that 3180 expose the cmd_ctrl() interface. 3181 3182 CONFIG_SPL_UBI 3183 Support for a lightweight UBI (fastmap) scanner and 3184 loader 3185 3186 CONFIG_SPL_NAND_RAW_ONLY 3187 Support to boot only raw u-boot.bin images. Use this only 3188 if you need to save space. 3189 3190 CONFIG_SPL_COMMON_INIT_DDR 3191 Set for common ddr init with serial presence detect in 3192 SPL binary. 3193 3194 CONFIG_SYS_NAND_5_ADDR_CYCLE, CONFIG_SYS_NAND_PAGE_COUNT, 3195 CONFIG_SYS_NAND_PAGE_SIZE, CONFIG_SYS_NAND_OOBSIZE, 3196 CONFIG_SYS_NAND_BLOCK_SIZE, CONFIG_SYS_NAND_BAD_BLOCK_POS, 3197 CONFIG_SYS_NAND_ECCPOS, CONFIG_SYS_NAND_ECCSIZE, 3198 CONFIG_SYS_NAND_ECCBYTES 3199 Defines the size and behavior of the NAND that SPL uses 3200 to read U-Boot 3201 3202 CONFIG_SPL_NAND_BOOT 3203 Add support NAND boot 3204 3205 CONFIG_SYS_NAND_U_BOOT_OFFS 3206 Location in NAND to read U-Boot from 3207 3208 CONFIG_SYS_NAND_U_BOOT_DST 3209 Location in memory to load U-Boot to 3210 3211 CONFIG_SYS_NAND_U_BOOT_SIZE 3212 Size of image to load 3213 3214 CONFIG_SYS_NAND_U_BOOT_START 3215 Entry point in loaded image to jump to 3216 3217 CONFIG_SYS_NAND_HW_ECC_OOBFIRST 3218 Define this if you need to first read the OOB and then the 3219 data. This is used, for example, on davinci platforms. 3220 3221 CONFIG_SPL_OMAP3_ID_NAND 3222 Support for an OMAP3-specific set of functions to return the 3223 ID and MFR of the first attached NAND chip, if present. 3224 3225 CONFIG_SPL_RAM_DEVICE 3226 Support for running image already present in ram, in SPL binary 3227 3228 CONFIG_SPL_PAD_TO 3229 Image offset to which the SPL should be padded before appending 3230 the SPL payload. By default, this is defined as 3231 CONFIG_SPL_MAX_SIZE, or 0 if CONFIG_SPL_MAX_SIZE is undefined. 3232 CONFIG_SPL_PAD_TO must be either 0, meaning to append the SPL 3233 payload without any padding, or >= CONFIG_SPL_MAX_SIZE. 3234 3235 CONFIG_SPL_TARGET 3236 Final target image containing SPL and payload. Some SPLs 3237 use an arch-specific makefile fragment instead, for 3238 example if more than one image needs to be produced. 3239 3240 CONFIG_FIT_SPL_PRINT 3241 Printing information about a FIT image adds quite a bit of 3242 code to SPL. So this is normally disabled in SPL. Use this 3243 option to re-enable it. This will affect the output of the 3244 bootm command when booting a FIT image. 3245 3246- TPL framework 3247 CONFIG_TPL 3248 Enable building of TPL globally. 3249 3250 CONFIG_TPL_PAD_TO 3251 Image offset to which the TPL should be padded before appending 3252 the TPL payload. By default, this is defined as 3253 CONFIG_SPL_MAX_SIZE, or 0 if CONFIG_SPL_MAX_SIZE is undefined. 3254 CONFIG_SPL_PAD_TO must be either 0, meaning to append the SPL 3255 payload without any padding, or >= CONFIG_SPL_MAX_SIZE. 3256 3257- Interrupt support (PPC): 3258 3259 There are common interrupt_init() and timer_interrupt() 3260 for all PPC archs. interrupt_init() calls interrupt_init_cpu() 3261 for CPU specific initialization. interrupt_init_cpu() 3262 should set decrementer_count to appropriate value. If 3263 CPU resets decrementer automatically after interrupt 3264 (ppc4xx) it should set decrementer_count to zero. 3265 timer_interrupt() calls timer_interrupt_cpu() for CPU 3266 specific handling. If board has watchdog / status_led 3267 / other_activity_monitor it works automatically from 3268 general timer_interrupt(). 3269 3270 3271Board initialization settings: 3272------------------------------ 3273 3274During Initialization u-boot calls a number of board specific functions 3275to allow the preparation of board specific prerequisites, e.g. pin setup 3276before drivers are initialized. To enable these callbacks the 3277following configuration macros have to be defined. Currently this is 3278architecture specific, so please check arch/your_architecture/lib/board.c 3279typically in board_init_f() and board_init_r(). 3280 3281- CONFIG_BOARD_EARLY_INIT_F: Call board_early_init_f() 3282- CONFIG_BOARD_EARLY_INIT_R: Call board_early_init_r() 3283- CONFIG_BOARD_LATE_INIT: Call board_late_init() 3284- CONFIG_BOARD_POSTCLK_INIT: Call board_postclk_init() 3285 3286Configuration Settings: 3287----------------------- 3288 3289- CONFIG_SYS_SUPPORT_64BIT_DATA: Defined automatically if compiled as 64-bit. 3290 Optionally it can be defined to support 64-bit memory commands. 3291 3292- CONFIG_SYS_LONGHELP: Defined when you want long help messages included; 3293 undefine this when you're short of memory. 3294 3295- CONFIG_SYS_HELP_CMD_WIDTH: Defined when you want to override the default 3296 width of the commands listed in the 'help' command output. 3297 3298- CONFIG_SYS_PROMPT: This is what U-Boot prints on the console to 3299 prompt for user input. 3300 3301- CONFIG_SYS_CBSIZE: Buffer size for input from the Console 3302 3303- CONFIG_SYS_PBSIZE: Buffer size for Console output 3304 3305- CONFIG_SYS_MAXARGS: max. Number of arguments accepted for monitor commands 3306 3307- CONFIG_SYS_BARGSIZE: Buffer size for Boot Arguments which are passed to 3308 the application (usually a Linux kernel) when it is 3309 booted 3310 3311- CONFIG_SYS_BAUDRATE_TABLE: 3312 List of legal baudrate settings for this board. 3313 3314- CONFIG_SYS_MEMTEST_START, CONFIG_SYS_MEMTEST_END: 3315 Begin and End addresses of the area used by the 3316 simple memory test. 3317 3318- CONFIG_SYS_ALT_MEMTEST: 3319 Enable an alternate, more extensive memory test. 3320 3321- CONFIG_SYS_MEMTEST_SCRATCH: 3322 Scratch address used by the alternate memory test 3323 You only need to set this if address zero isn't writeable 3324 3325- CONFIG_SYS_MEM_RESERVE_SECURE 3326 Only implemented for ARMv8 for now. 3327 If defined, the size of CONFIG_SYS_MEM_RESERVE_SECURE memory 3328 is substracted from total RAM and won't be reported to OS. 3329 This memory can be used as secure memory. A variable 3330 gd->arch.secure_ram is used to track the location. In systems 3331 the RAM base is not zero, or RAM is divided into banks, 3332 this variable needs to be recalcuated to get the address. 3333 3334- CONFIG_SYS_MEM_TOP_HIDE: 3335 If CONFIG_SYS_MEM_TOP_HIDE is defined in the board config header, 3336 this specified memory area will get subtracted from the top 3337 (end) of RAM and won't get "touched" at all by U-Boot. By 3338 fixing up gd->ram_size the Linux kernel should gets passed 3339 the now "corrected" memory size and won't touch it either. 3340 This should work for arch/ppc and arch/powerpc. Only Linux 3341 board ports in arch/powerpc with bootwrapper support that 3342 recalculate the memory size from the SDRAM controller setup 3343 will have to get fixed in Linux additionally. 3344 3345 This option can be used as a workaround for the 440EPx/GRx 3346 CHIP 11 errata where the last 256 bytes in SDRAM shouldn't 3347 be touched. 3348 3349 WARNING: Please make sure that this value is a multiple of 3350 the Linux page size (normally 4k). If this is not the case, 3351 then the end address of the Linux memory will be located at a 3352 non page size aligned address and this could cause major 3353 problems. 3354 3355- CONFIG_SYS_LOADS_BAUD_CHANGE: 3356 Enable temporary baudrate change while serial download 3357 3358- CONFIG_SYS_SDRAM_BASE: 3359 Physical start address of SDRAM. _Must_ be 0 here. 3360 3361- CONFIG_SYS_FLASH_BASE: 3362 Physical start address of Flash memory. 3363 3364- CONFIG_SYS_MONITOR_BASE: 3365 Physical start address of boot monitor code (set by 3366 make config files to be same as the text base address 3367 (CONFIG_SYS_TEXT_BASE) used when linking) - same as 3368 CONFIG_SYS_FLASH_BASE when booting from flash. 3369 3370- CONFIG_SYS_MONITOR_LEN: 3371 Size of memory reserved for monitor code, used to 3372 determine _at_compile_time_ (!) if the environment is 3373 embedded within the U-Boot image, or in a separate 3374 flash sector. 3375 3376- CONFIG_SYS_MALLOC_LEN: 3377 Size of DRAM reserved for malloc() use. 3378 3379- CONFIG_SYS_MALLOC_F_LEN 3380 Size of the malloc() pool for use before relocation. If 3381 this is defined, then a very simple malloc() implementation 3382 will become available before relocation. The address is just 3383 below the global data, and the stack is moved down to make 3384 space. 3385 3386 This feature allocates regions with increasing addresses 3387 within the region. calloc() is supported, but realloc() 3388 is not available. free() is supported but does nothing. 3389 The memory will be freed (or in fact just forgotten) when 3390 U-Boot relocates itself. 3391 3392- CONFIG_SYS_MALLOC_SIMPLE 3393 Provides a simple and small malloc() and calloc() for those 3394 boards which do not use the full malloc in SPL (which is 3395 enabled with CONFIG_SYS_SPL_MALLOC_START). 3396 3397- CONFIG_SYS_NONCACHED_MEMORY: 3398 Size of non-cached memory area. This area of memory will be 3399 typically located right below the malloc() area and mapped 3400 uncached in the MMU. This is useful for drivers that would 3401 otherwise require a lot of explicit cache maintenance. For 3402 some drivers it's also impossible to properly maintain the 3403 cache. For example if the regions that need to be flushed 3404 are not a multiple of the cache-line size, *and* padding 3405 cannot be allocated between the regions to align them (i.e. 3406 if the HW requires a contiguous array of regions, and the 3407 size of each region is not cache-aligned), then a flush of 3408 one region may result in overwriting data that hardware has 3409 written to another region in the same cache-line. This can 3410 happen for example in network drivers where descriptors for 3411 buffers are typically smaller than the CPU cache-line (e.g. 3412 16 bytes vs. 32 or 64 bytes). 3413 3414 Non-cached memory is only supported on 32-bit ARM at present. 3415 3416- CONFIG_SYS_BOOTM_LEN: 3417 Normally compressed uImages are limited to an 3418 uncompressed size of 8 MBytes. If this is not enough, 3419 you can define CONFIG_SYS_BOOTM_LEN in your board config file 3420 to adjust this setting to your needs. 3421 3422- CONFIG_SYS_BOOTMAPSZ: 3423 Maximum size of memory mapped by the startup code of 3424 the Linux kernel; all data that must be processed by 3425 the Linux kernel (bd_info, boot arguments, FDT blob if 3426 used) must be put below this limit, unless "bootm_low" 3427 environment variable is defined and non-zero. In such case 3428 all data for the Linux kernel must be between "bootm_low" 3429 and "bootm_low" + CONFIG_SYS_BOOTMAPSZ. The environment 3430 variable "bootm_mapsize" will override the value of 3431 CONFIG_SYS_BOOTMAPSZ. If CONFIG_SYS_BOOTMAPSZ is undefined, 3432 then the value in "bootm_size" will be used instead. 3433 3434- CONFIG_SYS_BOOT_RAMDISK_HIGH: 3435 Enable initrd_high functionality. If defined then the 3436 initrd_high feature is enabled and the bootm ramdisk subcommand 3437 is enabled. 3438 3439- CONFIG_SYS_BOOT_GET_CMDLINE: 3440 Enables allocating and saving kernel cmdline in space between 3441 "bootm_low" and "bootm_low" + BOOTMAPSZ. 3442 3443- CONFIG_SYS_BOOT_GET_KBD: 3444 Enables allocating and saving a kernel copy of the bd_info in 3445 space between "bootm_low" and "bootm_low" + BOOTMAPSZ. 3446 3447- CONFIG_SYS_MAX_FLASH_BANKS: 3448 Max number of Flash memory banks 3449 3450- CONFIG_SYS_MAX_FLASH_SECT: 3451 Max number of sectors on a Flash chip 3452 3453- CONFIG_SYS_FLASH_ERASE_TOUT: 3454 Timeout for Flash erase operations (in ms) 3455 3456- CONFIG_SYS_FLASH_WRITE_TOUT: 3457 Timeout for Flash write operations (in ms) 3458 3459- CONFIG_SYS_FLASH_LOCK_TOUT 3460 Timeout for Flash set sector lock bit operation (in ms) 3461 3462- CONFIG_SYS_FLASH_UNLOCK_TOUT 3463 Timeout for Flash clear lock bits operation (in ms) 3464 3465- CONFIG_SYS_FLASH_PROTECTION 3466 If defined, hardware flash sectors protection is used 3467 instead of U-Boot software protection. 3468 3469- CONFIG_SYS_DIRECT_FLASH_TFTP: 3470 3471 Enable TFTP transfers directly to flash memory; 3472 without this option such a download has to be 3473 performed in two steps: (1) download to RAM, and (2) 3474 copy from RAM to flash. 3475 3476 The two-step approach is usually more reliable, since 3477 you can check if the download worked before you erase 3478 the flash, but in some situations (when system RAM is 3479 too limited to allow for a temporary copy of the 3480 downloaded image) this option may be very useful. 3481 3482- CONFIG_SYS_FLASH_CFI: 3483 Define if the flash driver uses extra elements in the 3484 common flash structure for storing flash geometry. 3485 3486- CONFIG_FLASH_CFI_DRIVER 3487 This option also enables the building of the cfi_flash driver 3488 in the drivers directory 3489 3490- CONFIG_FLASH_CFI_MTD 3491 This option enables the building of the cfi_mtd driver 3492 in the drivers directory. The driver exports CFI flash 3493 to the MTD layer. 3494 3495- CONFIG_SYS_FLASH_USE_BUFFER_WRITE 3496 Use buffered writes to flash. 3497 3498- CONFIG_FLASH_SPANSION_S29WS_N 3499 s29ws-n MirrorBit flash has non-standard addresses for buffered 3500 write commands. 3501 3502- CONFIG_SYS_FLASH_QUIET_TEST 3503 If this option is defined, the common CFI flash doesn't 3504 print it's warning upon not recognized FLASH banks. This 3505 is useful, if some of the configured banks are only 3506 optionally available. 3507 3508- CONFIG_FLASH_SHOW_PROGRESS 3509 If defined (must be an integer), print out countdown 3510 digits and dots. Recommended value: 45 (9..1) for 80 3511 column displays, 15 (3..1) for 40 column displays. 3512 3513- CONFIG_FLASH_VERIFY 3514 If defined, the content of the flash (destination) is compared 3515 against the source after the write operation. An error message 3516 will be printed when the contents are not identical. 3517 Please note that this option is useless in nearly all cases, 3518 since such flash programming errors usually are detected earlier 3519 while unprotecting/erasing/programming. Please only enable 3520 this option if you really know what you are doing. 3521 3522- CONFIG_SYS_RX_ETH_BUFFER: 3523 Defines the number of Ethernet receive buffers. On some 3524 Ethernet controllers it is recommended to set this value 3525 to 8 or even higher (EEPRO100 or 405 EMAC), since all 3526 buffers can be full shortly after enabling the interface 3527 on high Ethernet traffic. 3528 Defaults to 4 if not defined. 3529 3530- CONFIG_ENV_MAX_ENTRIES 3531 3532 Maximum number of entries in the hash table that is used 3533 internally to store the environment settings. The default 3534 setting is supposed to be generous and should work in most 3535 cases. This setting can be used to tune behaviour; see 3536 lib/hashtable.c for details. 3537 3538- CONFIG_ENV_FLAGS_LIST_DEFAULT 3539- CONFIG_ENV_FLAGS_LIST_STATIC 3540 Enable validation of the values given to environment variables when 3541 calling env set. Variables can be restricted to only decimal, 3542 hexadecimal, or boolean. If CONFIG_CMD_NET is also defined, 3543 the variables can also be restricted to IP address or MAC address. 3544 3545 The format of the list is: 3546 type_attribute = [s|d|x|b|i|m] 3547 access_attribute = [a|r|o|c] 3548 attributes = type_attribute[access_attribute] 3549 entry = variable_name[:attributes] 3550 list = entry[,list] 3551 3552 The type attributes are: 3553 s - String (default) 3554 d - Decimal 3555 x - Hexadecimal 3556 b - Boolean ([1yYtT|0nNfF]) 3557 i - IP address 3558 m - MAC address 3559 3560 The access attributes are: 3561 a - Any (default) 3562 r - Read-only 3563 o - Write-once 3564 c - Change-default 3565 3566 - CONFIG_ENV_FLAGS_LIST_DEFAULT 3567 Define this to a list (string) to define the ".flags" 3568 environment variable in the default or embedded environment. 3569 3570 - CONFIG_ENV_FLAGS_LIST_STATIC 3571 Define this to a list (string) to define validation that 3572 should be done if an entry is not found in the ".flags" 3573 environment variable. To override a setting in the static 3574 list, simply add an entry for the same variable name to the 3575 ".flags" variable. 3576 3577 If CONFIG_REGEX is defined, the variable_name above is evaluated as a 3578 regular expression. This allows multiple variables to define the same 3579 flags without explicitly listing them for each variable. 3580 3581- CONFIG_ENV_ACCESS_IGNORE_FORCE 3582 If defined, don't allow the -f switch to env set override variable 3583 access flags. 3584 3585- CONFIG_USE_STDINT 3586 If stdint.h is available with your toolchain you can define this 3587 option to enable it. You can provide option 'USE_STDINT=1' when 3588 building U-Boot to enable this. 3589 3590The following definitions that deal with the placement and management 3591of environment data (variable area); in general, we support the 3592following configurations: 3593 3594- CONFIG_BUILD_ENVCRC: 3595 3596 Builds up envcrc with the target environment so that external utils 3597 may easily extract it and embed it in final U-Boot images. 3598 3599- CONFIG_ENV_IS_IN_FLASH: 3600 3601 Define this if the environment is in flash memory. 3602 3603 a) The environment occupies one whole flash sector, which is 3604 "embedded" in the text segment with the U-Boot code. This 3605 happens usually with "bottom boot sector" or "top boot 3606 sector" type flash chips, which have several smaller 3607 sectors at the start or the end. For instance, such a 3608 layout can have sector sizes of 8, 2x4, 16, Nx32 kB. In 3609 such a case you would place the environment in one of the 3610 4 kB sectors - with U-Boot code before and after it. With 3611 "top boot sector" type flash chips, you would put the 3612 environment in one of the last sectors, leaving a gap 3613 between U-Boot and the environment. 3614 3615 - CONFIG_ENV_OFFSET: 3616 3617 Offset of environment data (variable area) to the 3618 beginning of flash memory; for instance, with bottom boot 3619 type flash chips the second sector can be used: the offset 3620 for this sector is given here. 3621 3622 CONFIG_ENV_OFFSET is used relative to CONFIG_SYS_FLASH_BASE. 3623 3624 - CONFIG_ENV_ADDR: 3625 3626 This is just another way to specify the start address of 3627 the flash sector containing the environment (instead of 3628 CONFIG_ENV_OFFSET). 3629 3630 - CONFIG_ENV_SECT_SIZE: 3631 3632 Size of the sector containing the environment. 3633 3634 3635 b) Sometimes flash chips have few, equal sized, BIG sectors. 3636 In such a case you don't want to spend a whole sector for 3637 the environment. 3638 3639 - CONFIG_ENV_SIZE: 3640 3641 If you use this in combination with CONFIG_ENV_IS_IN_FLASH 3642 and CONFIG_ENV_SECT_SIZE, you can specify to use only a part 3643 of this flash sector for the environment. This saves 3644 memory for the RAM copy of the environment. 3645 3646 It may also save flash memory if you decide to use this 3647 when your environment is "embedded" within U-Boot code, 3648 since then the remainder of the flash sector could be used 3649 for U-Boot code. It should be pointed out that this is 3650 STRONGLY DISCOURAGED from a robustness point of view: 3651 updating the environment in flash makes it always 3652 necessary to erase the WHOLE sector. If something goes 3653 wrong before the contents has been restored from a copy in 3654 RAM, your target system will be dead. 3655 3656 - CONFIG_ENV_ADDR_REDUND 3657 CONFIG_ENV_SIZE_REDUND 3658 3659 These settings describe a second storage area used to hold 3660 a redundant copy of the environment data, so that there is 3661 a valid backup copy in case there is a power failure during 3662 a "saveenv" operation. 3663 3664BE CAREFUL! Any changes to the flash layout, and some changes to the 3665source code will make it necessary to adapt <board>/u-boot.lds* 3666accordingly! 3667 3668 3669- CONFIG_ENV_IS_IN_NVRAM: 3670 3671 Define this if you have some non-volatile memory device 3672 (NVRAM, battery buffered SRAM) which you want to use for the 3673 environment. 3674 3675 - CONFIG_ENV_ADDR: 3676 - CONFIG_ENV_SIZE: 3677 3678 These two #defines are used to determine the memory area you 3679 want to use for environment. It is assumed that this memory 3680 can just be read and written to, without any special 3681 provision. 3682 3683BE CAREFUL! The first access to the environment happens quite early 3684in U-Boot initialization (when we try to get the setting of for the 3685console baudrate). You *MUST* have mapped your NVRAM area then, or 3686U-Boot will hang. 3687 3688Please note that even with NVRAM we still use a copy of the 3689environment in RAM: we could work on NVRAM directly, but we want to 3690keep settings there always unmodified except somebody uses "saveenv" 3691to save the current settings. 3692 3693 3694- CONFIG_ENV_IS_IN_EEPROM: 3695 3696 Use this if you have an EEPROM or similar serial access 3697 device and a driver for it. 3698 3699 - CONFIG_ENV_OFFSET: 3700 - CONFIG_ENV_SIZE: 3701 3702 These two #defines specify the offset and size of the 3703 environment area within the total memory of your EEPROM. 3704 3705 - CONFIG_SYS_I2C_EEPROM_ADDR: 3706 If defined, specified the chip address of the EEPROM device. 3707 The default address is zero. 3708 3709 - CONFIG_SYS_I2C_EEPROM_BUS: 3710 If defined, specified the i2c bus of the EEPROM device. 3711 3712 - CONFIG_SYS_EEPROM_PAGE_WRITE_BITS: 3713 If defined, the number of bits used to address bytes in a 3714 single page in the EEPROM device. A 64 byte page, for example 3715 would require six bits. 3716 3717 - CONFIG_SYS_EEPROM_PAGE_WRITE_DELAY_MS: 3718 If defined, the number of milliseconds to delay between 3719 page writes. The default is zero milliseconds. 3720 3721 - CONFIG_SYS_I2C_EEPROM_ADDR_LEN: 3722 The length in bytes of the EEPROM memory array address. Note 3723 that this is NOT the chip address length! 3724 3725 - CONFIG_SYS_I2C_EEPROM_ADDR_OVERFLOW: 3726 EEPROM chips that implement "address overflow" are ones 3727 like Catalyst 24WC04/08/16 which has 9/10/11 bits of 3728 address and the extra bits end up in the "chip address" bit 3729 slots. This makes a 24WC08 (1Kbyte) chip look like four 256 3730 byte chips. 3731 3732 Note that we consider the length of the address field to 3733 still be one byte because the extra address bits are hidden 3734 in the chip address. 3735 3736 - CONFIG_SYS_EEPROM_SIZE: 3737 The size in bytes of the EEPROM device. 3738 3739 - CONFIG_ENV_EEPROM_IS_ON_I2C 3740 define this, if you have I2C and SPI activated, and your 3741 EEPROM, which holds the environment, is on the I2C bus. 3742 3743 - CONFIG_I2C_ENV_EEPROM_BUS 3744 if you have an Environment on an EEPROM reached over 3745 I2C muxes, you can define here, how to reach this 3746 EEPROM. For example: 3747 3748 #define CONFIG_I2C_ENV_EEPROM_BUS 1 3749 3750 EEPROM which holds the environment, is reached over 3751 a pca9547 i2c mux with address 0x70, channel 3. 3752 3753- CONFIG_ENV_IS_IN_DATAFLASH: 3754 3755 Define this if you have a DataFlash memory device which you 3756 want to use for the environment. 3757 3758 - CONFIG_ENV_OFFSET: 3759 - CONFIG_ENV_ADDR: 3760 - CONFIG_ENV_SIZE: 3761 3762 These three #defines specify the offset and size of the 3763 environment area within the total memory of your DataFlash placed 3764 at the specified address. 3765 3766- CONFIG_ENV_IS_IN_SPI_FLASH: 3767 3768 Define this if you have a SPI Flash memory device which you 3769 want to use for the environment. 3770 3771 - CONFIG_ENV_OFFSET: 3772 - CONFIG_ENV_SIZE: 3773 3774 These two #defines specify the offset and size of the 3775 environment area within the SPI Flash. CONFIG_ENV_OFFSET must be 3776 aligned to an erase sector boundary. 3777 3778 - CONFIG_ENV_SECT_SIZE: 3779 3780 Define the SPI flash's sector size. 3781 3782 - CONFIG_ENV_OFFSET_REDUND (optional): 3783 3784 This setting describes a second storage area of CONFIG_ENV_SIZE 3785 size used to hold a redundant copy of the environment data, so 3786 that there is a valid backup copy in case there is a power failure 3787 during a "saveenv" operation. CONFIG_ENV_OFFSET_REDUND must be 3788 aligned to an erase sector boundary. 3789 3790 - CONFIG_ENV_SPI_BUS (optional): 3791 - CONFIG_ENV_SPI_CS (optional): 3792 3793 Define the SPI bus and chip select. If not defined they will be 0. 3794 3795 - CONFIG_ENV_SPI_MAX_HZ (optional): 3796 3797 Define the SPI max work clock. If not defined then use 1MHz. 3798 3799 - CONFIG_ENV_SPI_MODE (optional): 3800 3801 Define the SPI work mode. If not defined then use SPI_MODE_3. 3802 3803- CONFIG_ENV_IS_IN_REMOTE: 3804 3805 Define this if you have a remote memory space which you 3806 want to use for the local device's environment. 3807 3808 - CONFIG_ENV_ADDR: 3809 - CONFIG_ENV_SIZE: 3810 3811 These two #defines specify the address and size of the 3812 environment area within the remote memory space. The 3813 local device can get the environment from remote memory 3814 space by SRIO or PCIE links. 3815 3816BE CAREFUL! For some special cases, the local device can not use 3817"saveenv" command. For example, the local device will get the 3818environment stored in a remote NOR flash by SRIO or PCIE link, 3819but it can not erase, write this NOR flash by SRIO or PCIE interface. 3820 3821- CONFIG_ENV_IS_IN_NAND: 3822 3823 Define this if you have a NAND device which you want to use 3824 for the environment. 3825 3826 - CONFIG_ENV_OFFSET: 3827 - CONFIG_ENV_SIZE: 3828 3829 These two #defines specify the offset and size of the environment 3830 area within the first NAND device. CONFIG_ENV_OFFSET must be 3831 aligned to an erase block boundary. 3832 3833 - CONFIG_ENV_OFFSET_REDUND (optional): 3834 3835 This setting describes a second storage area of CONFIG_ENV_SIZE 3836 size used to hold a redundant copy of the environment data, so 3837 that there is a valid backup copy in case there is a power failure 3838 during a "saveenv" operation. CONFIG_ENV_OFFSET_REDUND must be 3839 aligned to an erase block boundary. 3840 3841 - CONFIG_ENV_RANGE (optional): 3842 3843 Specifies the length of the region in which the environment 3844 can be written. This should be a multiple of the NAND device's 3845 block size. Specifying a range with more erase blocks than 3846 are needed to hold CONFIG_ENV_SIZE allows bad blocks within 3847 the range to be avoided. 3848 3849 - CONFIG_ENV_OFFSET_OOB (optional): 3850 3851 Enables support for dynamically retrieving the offset of the 3852 environment from block zero's out-of-band data. The 3853 "nand env.oob" command can be used to record this offset. 3854 Currently, CONFIG_ENV_OFFSET_REDUND is not supported when 3855 using CONFIG_ENV_OFFSET_OOB. 3856 3857- CONFIG_NAND_ENV_DST 3858 3859 Defines address in RAM to which the nand_spl code should copy the 3860 environment. If redundant environment is used, it will be copied to 3861 CONFIG_NAND_ENV_DST + CONFIG_ENV_SIZE. 3862 3863- CONFIG_ENV_IS_IN_UBI: 3864 3865 Define this if you have an UBI volume that you want to use for the 3866 environment. This has the benefit of wear-leveling the environment 3867 accesses, which is important on NAND. 3868 3869 - CONFIG_ENV_UBI_PART: 3870 3871 Define this to a string that is the mtd partition containing the UBI. 3872 3873 - CONFIG_ENV_UBI_VOLUME: 3874 3875 Define this to the name of the volume that you want to store the 3876 environment in. 3877 3878 - CONFIG_ENV_UBI_VOLUME_REDUND: 3879 3880 Define this to the name of another volume to store a second copy of 3881 the environment in. This will enable redundant environments in UBI. 3882 It is assumed that both volumes are in the same MTD partition. 3883 3884 - CONFIG_UBI_SILENCE_MSG 3885 - CONFIG_UBIFS_SILENCE_MSG 3886 3887 You will probably want to define these to avoid a really noisy system 3888 when storing the env in UBI. 3889 3890- CONFIG_ENV_IS_IN_FAT: 3891 Define this if you want to use the FAT file system for the environment. 3892 3893 - FAT_ENV_INTERFACE: 3894 3895 Define this to a string that is the name of the block device. 3896 3897 - FAT_ENV_DEVICE_AND_PART: 3898 3899 Define this to a string to specify the partition of the device. It can 3900 be as following: 3901 3902 "D:P", "D:0", "D", "D:" or "D:auto" (D, P are integers. And P >= 1) 3903 - "D:P": device D partition P. Error occurs if device D has no 3904 partition table. 3905 - "D:0": device D. 3906 - "D" or "D:": device D partition 1 if device D has partition 3907 table, or the whole device D if has no partition 3908 table. 3909 - "D:auto": first partition in device D with bootable flag set. 3910 If none, first valid partition in device D. If no 3911 partition table then means device D. 3912 3913 - FAT_ENV_FILE: 3914 3915 It's a string of the FAT file name. This file use to store the 3916 environment. 3917 3918 - CONFIG_FAT_WRITE: 3919 This should be defined. Otherwise it cannot save the environment file. 3920 3921- CONFIG_ENV_IS_IN_MMC: 3922 3923 Define this if you have an MMC device which you want to use for the 3924 environment. 3925 3926 - CONFIG_SYS_MMC_ENV_DEV: 3927 3928 Specifies which MMC device the environment is stored in. 3929 3930 - CONFIG_SYS_MMC_ENV_PART (optional): 3931 3932 Specifies which MMC partition the environment is stored in. If not 3933 set, defaults to partition 0, the user area. Common values might be 3934 1 (first MMC boot partition), 2 (second MMC boot partition). 3935 3936 - CONFIG_ENV_OFFSET: 3937 - CONFIG_ENV_SIZE: 3938 3939 These two #defines specify the offset and size of the environment 3940 area within the specified MMC device. 3941 3942 If offset is positive (the usual case), it is treated as relative to 3943 the start of the MMC partition. If offset is negative, it is treated 3944 as relative to the end of the MMC partition. This can be useful if 3945 your board may be fitted with different MMC devices, which have 3946 different sizes for the MMC partitions, and you always want the 3947 environment placed at the very end of the partition, to leave the 3948 maximum possible space before it, to store other data. 3949 3950 These two values are in units of bytes, but must be aligned to an 3951 MMC sector boundary. 3952 3953 - CONFIG_ENV_OFFSET_REDUND (optional): 3954 3955 Specifies a second storage area, of CONFIG_ENV_SIZE size, used to 3956 hold a redundant copy of the environment data. This provides a 3957 valid backup copy in case the other copy is corrupted, e.g. due 3958 to a power failure during a "saveenv" operation. 3959 3960 This value may also be positive or negative; this is handled in the 3961 same way as CONFIG_ENV_OFFSET. 3962 3963 This value is also in units of bytes, but must also be aligned to 3964 an MMC sector boundary. 3965 3966 - CONFIG_ENV_SIZE_REDUND (optional): 3967 3968 This value need not be set, even when CONFIG_ENV_OFFSET_REDUND is 3969 set. If this value is set, it must be set to the same value as 3970 CONFIG_ENV_SIZE. 3971 3972- CONFIG_SYS_SPI_INIT_OFFSET 3973 3974 Defines offset to the initial SPI buffer area in DPRAM. The 3975 area is used at an early stage (ROM part) if the environment 3976 is configured to reside in the SPI EEPROM: We need a 520 byte 3977 scratch DPRAM area. It is used between the two initialization 3978 calls (spi_init_f() and spi_init_r()). A value of 0xB00 seems 3979 to be a good choice since it makes it far enough from the 3980 start of the data area as well as from the stack pointer. 3981 3982Please note that the environment is read-only until the monitor 3983has been relocated to RAM and a RAM copy of the environment has been 3984created; also, when using EEPROM you will have to use getenv_f() 3985until then to read environment variables. 3986 3987The environment is protected by a CRC32 checksum. Before the monitor 3988is relocated into RAM, as a result of a bad CRC you will be working 3989with the compiled-in default environment - *silently*!!! [This is 3990necessary, because the first environment variable we need is the 3991"baudrate" setting for the console - if we have a bad CRC, we don't 3992have any device yet where we could complain.] 3993 3994Note: once the monitor has been relocated, then it will complain if 3995the default environment is used; a new CRC is computed as soon as you 3996use the "saveenv" command to store a valid environment. 3997 3998- CONFIG_SYS_FAULT_ECHO_LINK_DOWN: 3999 Echo the inverted Ethernet link state to the fault LED. 4000 4001 Note: If this option is active, then CONFIG_SYS_FAULT_MII_ADDR 4002 also needs to be defined. 4003 4004- CONFIG_SYS_FAULT_MII_ADDR: 4005 MII address of the PHY to check for the Ethernet link state. 4006 4007- CONFIG_NS16550_MIN_FUNCTIONS: 4008 Define this if you desire to only have use of the NS16550_init 4009 and NS16550_putc functions for the serial driver located at 4010 drivers/serial/ns16550.c. This option is useful for saving 4011 space for already greatly restricted images, including but not 4012 limited to NAND_SPL configurations. 4013 4014- CONFIG_DISPLAY_BOARDINFO 4015 Display information about the board that U-Boot is running on 4016 when U-Boot starts up. The board function checkboard() is called 4017 to do this. 4018 4019- CONFIG_DISPLAY_BOARDINFO_LATE 4020 Similar to the previous option, but display this information 4021 later, once stdio is running and output goes to the LCD, if 4022 present. 4023 4024- CONFIG_BOARD_SIZE_LIMIT: 4025 Maximum size of the U-Boot image. When defined, the 4026 build system checks that the actual size does not 4027 exceed it. 4028 4029Low Level (hardware related) configuration options: 4030--------------------------------------------------- 4031 4032- CONFIG_SYS_CACHELINE_SIZE: 4033 Cache Line Size of the CPU. 4034 4035- CONFIG_SYS_DEFAULT_IMMR: 4036 Default address of the IMMR after system reset. 4037 4038 Needed on some 8260 systems (MPC8260ADS, PQ2FADS-ZU, 4039 and RPXsuper) to be able to adjust the position of 4040 the IMMR register after a reset. 4041 4042- CONFIG_SYS_CCSRBAR_DEFAULT: 4043 Default (power-on reset) physical address of CCSR on Freescale 4044 PowerPC SOCs. 4045 4046- CONFIG_SYS_CCSRBAR: 4047 Virtual address of CCSR. On a 32-bit build, this is typically 4048 the same value as CONFIG_SYS_CCSRBAR_DEFAULT. 4049 4050 CONFIG_SYS_DEFAULT_IMMR must also be set to this value, 4051 for cross-platform code that uses that macro instead. 4052 4053- CONFIG_SYS_CCSRBAR_PHYS: 4054 Physical address of CCSR. CCSR can be relocated to a new 4055 physical address, if desired. In this case, this macro should 4056 be set to that address. Otherwise, it should be set to the 4057 same value as CONFIG_SYS_CCSRBAR_DEFAULT. For example, CCSR 4058 is typically relocated on 36-bit builds. It is recommended 4059 that this macro be defined via the _HIGH and _LOW macros: 4060 4061 #define CONFIG_SYS_CCSRBAR_PHYS ((CONFIG_SYS_CCSRBAR_PHYS_HIGH 4062 * 1ull) << 32 | CONFIG_SYS_CCSRBAR_PHYS_LOW) 4063 4064- CONFIG_SYS_CCSRBAR_PHYS_HIGH: 4065 Bits 33-36 of CONFIG_SYS_CCSRBAR_PHYS. This value is typically 4066 either 0 (32-bit build) or 0xF (36-bit build). This macro is 4067 used in assembly code, so it must not contain typecasts or 4068 integer size suffixes (e.g. "ULL"). 4069 4070- CONFIG_SYS_CCSRBAR_PHYS_LOW: 4071 Lower 32-bits of CONFIG_SYS_CCSRBAR_PHYS. This macro is 4072 used in assembly code, so it must not contain typecasts or 4073 integer size suffixes (e.g. "ULL"). 4074 4075- CONFIG_SYS_CCSR_DO_NOT_RELOCATE: 4076 If this macro is defined, then CONFIG_SYS_CCSRBAR_PHYS will be 4077 forced to a value that ensures that CCSR is not relocated. 4078 4079- Floppy Disk Support: 4080 CONFIG_SYS_FDC_DRIVE_NUMBER 4081 4082 the default drive number (default value 0) 4083 4084 CONFIG_SYS_ISA_IO_STRIDE 4085 4086 defines the spacing between FDC chipset registers 4087 (default value 1) 4088 4089 CONFIG_SYS_ISA_IO_OFFSET 4090 4091 defines the offset of register from address. It 4092 depends on which part of the data bus is connected to 4093 the FDC chipset. (default value 0) 4094 4095 If CONFIG_SYS_ISA_IO_STRIDE CONFIG_SYS_ISA_IO_OFFSET and 4096 CONFIG_SYS_FDC_DRIVE_NUMBER are undefined, they take their 4097 default value. 4098 4099 if CONFIG_SYS_FDC_HW_INIT is defined, then the function 4100 fdc_hw_init() is called at the beginning of the FDC 4101 setup. fdc_hw_init() must be provided by the board 4102 source code. It is used to make hardware-dependent 4103 initializations. 4104 4105- CONFIG_IDE_AHB: 4106 Most IDE controllers were designed to be connected with PCI 4107 interface. Only few of them were designed for AHB interface. 4108 When software is doing ATA command and data transfer to 4109 IDE devices through IDE-AHB controller, some additional 4110 registers accessing to these kind of IDE-AHB controller 4111 is required. 4112 4113- CONFIG_SYS_IMMR: Physical address of the Internal Memory. 4114 DO NOT CHANGE unless you know exactly what you're 4115 doing! (11-4) [MPC8xx/82xx systems only] 4116 4117- CONFIG_SYS_INIT_RAM_ADDR: 4118 4119 Start address of memory area that can be used for 4120 initial data and stack; please note that this must be 4121 writable memory that is working WITHOUT special 4122 initialization, i. e. you CANNOT use normal RAM which 4123 will become available only after programming the 4124 memory controller and running certain initialization 4125 sequences. 4126 4127 U-Boot uses the following memory types: 4128 - MPC8xx and MPC8260: IMMR (internal memory of the CPU) 4129 - MPC824X: data cache 4130 - PPC4xx: data cache 4131 4132- CONFIG_SYS_GBL_DATA_OFFSET: 4133 4134 Offset of the initial data structure in the memory 4135 area defined by CONFIG_SYS_INIT_RAM_ADDR. Usually 4136 CONFIG_SYS_GBL_DATA_OFFSET is chosen such that the initial 4137 data is located at the end of the available space 4138 (sometimes written as (CONFIG_SYS_INIT_RAM_SIZE - 4139 GENERATED_GBL_DATA_SIZE), and the initial stack is just 4140 below that area (growing from (CONFIG_SYS_INIT_RAM_ADDR + 4141 CONFIG_SYS_GBL_DATA_OFFSET) downward. 4142 4143 Note: 4144 On the MPC824X (or other systems that use the data 4145 cache for initial memory) the address chosen for 4146 CONFIG_SYS_INIT_RAM_ADDR is basically arbitrary - it must 4147 point to an otherwise UNUSED address space between 4148 the top of RAM and the start of the PCI space. 4149 4150- CONFIG_SYS_SIUMCR: SIU Module Configuration (11-6) 4151 4152- CONFIG_SYS_SYPCR: System Protection Control (11-9) 4153 4154- CONFIG_SYS_TBSCR: Time Base Status and Control (11-26) 4155 4156- CONFIG_SYS_PISCR: Periodic Interrupt Status and Control (11-31) 4157 4158- CONFIG_SYS_PLPRCR: PLL, Low-Power, and Reset Control Register (15-30) 4159 4160- CONFIG_SYS_SCCR: System Clock and reset Control Register (15-27) 4161 4162- CONFIG_SYS_OR_TIMING_SDRAM: 4163 SDRAM timing 4164 4165- CONFIG_SYS_MAMR_PTA: 4166 periodic timer for refresh 4167 4168- CONFIG_SYS_DER: Debug Event Register (37-47) 4169 4170- FLASH_BASE0_PRELIM, FLASH_BASE1_PRELIM, CONFIG_SYS_REMAP_OR_AM, 4171 CONFIG_SYS_PRELIM_OR_AM, CONFIG_SYS_OR_TIMING_FLASH, CONFIG_SYS_OR0_REMAP, 4172 CONFIG_SYS_OR0_PRELIM, CONFIG_SYS_BR0_PRELIM, CONFIG_SYS_OR1_REMAP, CONFIG_SYS_OR1_PRELIM, 4173 CONFIG_SYS_BR1_PRELIM: 4174 Memory Controller Definitions: BR0/1 and OR0/1 (FLASH) 4175 4176- SDRAM_BASE2_PRELIM, SDRAM_BASE3_PRELIM, SDRAM_MAX_SIZE, 4177 CONFIG_SYS_OR_TIMING_SDRAM, CONFIG_SYS_OR2_PRELIM, CONFIG_SYS_BR2_PRELIM, 4178 CONFIG_SYS_OR3_PRELIM, CONFIG_SYS_BR3_PRELIM: 4179 Memory Controller Definitions: BR2/3 and OR2/3 (SDRAM) 4180 4181- CONFIG_SYS_MAMR_PTA, CONFIG_SYS_MPTPR_2BK_4K, CONFIG_SYS_MPTPR_1BK_4K, CONFIG_SYS_MPTPR_2BK_8K, 4182 CONFIG_SYS_MPTPR_1BK_8K, CONFIG_SYS_MAMR_8COL, CONFIG_SYS_MAMR_9COL: 4183 Machine Mode Register and Memory Periodic Timer 4184 Prescaler definitions (SDRAM timing) 4185 4186- CONFIG_SYS_I2C_UCODE_PATCH, CONFIG_SYS_I2C_DPMEM_OFFSET [0x1FC0]: 4187 enable I2C microcode relocation patch (MPC8xx); 4188 define relocation offset in DPRAM [DSP2] 4189 4190- CONFIG_SYS_SMC_UCODE_PATCH, CONFIG_SYS_SMC_DPMEM_OFFSET [0x1FC0]: 4191 enable SMC microcode relocation patch (MPC8xx); 4192 define relocation offset in DPRAM [SMC1] 4193 4194- CONFIG_SYS_SPI_UCODE_PATCH, CONFIG_SYS_SPI_DPMEM_OFFSET [0x1FC0]: 4195 enable SPI microcode relocation patch (MPC8xx); 4196 define relocation offset in DPRAM [SCC4] 4197 4198- CONFIG_SYS_CPM_POST_WORD_ADDR: (MPC8xx, MPC8260 only) 4199 Offset of the bootmode word in DPRAM used by post 4200 (Power On Self Tests). This definition overrides 4201 #define'd default value in commproc.h resp. 4202 cpm_8260.h. 4203 4204- CONFIG_SYS_PCI_SLV_MEM_LOCAL, CONFIG_SYS_PCI_SLV_MEM_BUS, CONFIG_SYS_PICMR0_MASK_ATTRIB, 4205 CONFIG_SYS_PCI_MSTR0_LOCAL, CONFIG_SYS_PCIMSK0_MASK, CONFIG_SYS_PCI_MSTR1_LOCAL, 4206 CONFIG_SYS_PCIMSK1_MASK, CONFIG_SYS_PCI_MSTR_MEM_LOCAL, CONFIG_SYS_PCI_MSTR_MEM_BUS, 4207 CONFIG_SYS_CPU_PCI_MEM_START, CONFIG_SYS_PCI_MSTR_MEM_SIZE, CONFIG_SYS_POCMR0_MASK_ATTRIB, 4208 CONFIG_SYS_PCI_MSTR_MEMIO_LOCAL, CONFIG_SYS_PCI_MSTR_MEMIO_BUS, CPU_PCI_MEMIO_START, 4209 CONFIG_SYS_PCI_MSTR_MEMIO_SIZE, CONFIG_SYS_POCMR1_MASK_ATTRIB, CONFIG_SYS_PCI_MSTR_IO_LOCAL, 4210 CONFIG_SYS_PCI_MSTR_IO_BUS, CONFIG_SYS_CPU_PCI_IO_START, CONFIG_SYS_PCI_MSTR_IO_SIZE, 4211 CONFIG_SYS_POCMR2_MASK_ATTRIB: (MPC826x only) 4212 Overrides the default PCI memory map in arch/powerpc/cpu/mpc8260/pci.c if set. 4213 4214- CONFIG_PCI_DISABLE_PCIE: 4215 Disable PCI-Express on systems where it is supported but not 4216 required. 4217 4218- CONFIG_PCI_ENUM_ONLY 4219 Only scan through and get the devices on the buses. 4220 Don't do any setup work, presumably because someone or 4221 something has already done it, and we don't need to do it 4222 a second time. Useful for platforms that are pre-booted 4223 by coreboot or similar. 4224 4225- CONFIG_PCI_INDIRECT_BRIDGE: 4226 Enable support for indirect PCI bridges. 4227 4228- CONFIG_SYS_SRIO: 4229 Chip has SRIO or not 4230 4231- CONFIG_SRIO1: 4232 Board has SRIO 1 port available 4233 4234- CONFIG_SRIO2: 4235 Board has SRIO 2 port available 4236 4237- CONFIG_SRIO_PCIE_BOOT_MASTER 4238 Board can support master function for Boot from SRIO and PCIE 4239 4240- CONFIG_SYS_SRIOn_MEM_VIRT: 4241 Virtual Address of SRIO port 'n' memory region 4242 4243- CONFIG_SYS_SRIOn_MEM_PHYS: 4244 Physical Address of SRIO port 'n' memory region 4245 4246- CONFIG_SYS_SRIOn_MEM_SIZE: 4247 Size of SRIO port 'n' memory region 4248 4249- CONFIG_SYS_NAND_BUSWIDTH_16BIT 4250 Defined to tell the NAND controller that the NAND chip is using 4251 a 16 bit bus. 4252 Not all NAND drivers use this symbol. 4253 Example of drivers that use it: 4254 - drivers/mtd/nand/ndfc.c 4255 - drivers/mtd/nand/mxc_nand.c 4256 4257- CONFIG_SYS_NDFC_EBC0_CFG 4258 Sets the EBC0_CFG register for the NDFC. If not defined 4259 a default value will be used. 4260 4261- CONFIG_SPD_EEPROM 4262 Get DDR timing information from an I2C EEPROM. Common 4263 with pluggable memory modules such as SODIMMs 4264 4265 SPD_EEPROM_ADDRESS 4266 I2C address of the SPD EEPROM 4267 4268- CONFIG_SYS_SPD_BUS_NUM 4269 If SPD EEPROM is on an I2C bus other than the first 4270 one, specify here. Note that the value must resolve 4271 to something your driver can deal with. 4272 4273- CONFIG_SYS_DDR_RAW_TIMING 4274 Get DDR timing information from other than SPD. Common with 4275 soldered DDR chips onboard without SPD. DDR raw timing 4276 parameters are extracted from datasheet and hard-coded into 4277 header files or board specific files. 4278 4279- CONFIG_FSL_DDR_INTERACTIVE 4280 Enable interactive DDR debugging. See doc/README.fsl-ddr. 4281 4282- CONFIG_FSL_DDR_SYNC_REFRESH 4283 Enable sync of refresh for multiple controllers. 4284 4285- CONFIG_FSL_DDR_BIST 4286 Enable built-in memory test for Freescale DDR controllers. 4287 4288- CONFIG_SYS_83XX_DDR_USES_CS0 4289 Only for 83xx systems. If specified, then DDR should 4290 be configured using CS0 and CS1 instead of CS2 and CS3. 4291 4292- CONFIG_ETHER_ON_FEC[12] 4293 Define to enable FEC[12] on a 8xx series processor. 4294 4295- CONFIG_FEC[12]_PHY 4296 Define to the hardcoded PHY address which corresponds 4297 to the given FEC; i. e. 4298 #define CONFIG_FEC1_PHY 4 4299 means that the PHY with address 4 is connected to FEC1 4300 4301 When set to -1, means to probe for first available. 4302 4303- CONFIG_FEC[12]_PHY_NORXERR 4304 The PHY does not have a RXERR line (RMII only). 4305 (so program the FEC to ignore it). 4306 4307- CONFIG_RMII 4308 Enable RMII mode for all FECs. 4309 Note that this is a global option, we can't 4310 have one FEC in standard MII mode and another in RMII mode. 4311 4312- CONFIG_CRC32_VERIFY 4313 Add a verify option to the crc32 command. 4314 The syntax is: 4315 4316 => crc32 -v <address> <count> <crc32> 4317 4318 Where address/count indicate a memory area 4319 and crc32 is the correct crc32 which the 4320 area should have. 4321 4322- CONFIG_LOOPW 4323 Add the "loopw" memory command. This only takes effect if 4324 the memory commands are activated globally (CONFIG_CMD_MEM). 4325 4326- CONFIG_MX_CYCLIC 4327 Add the "mdc" and "mwc" memory commands. These are cyclic 4328 "md/mw" commands. 4329 Examples: 4330 4331 => mdc.b 10 4 500 4332 This command will print 4 bytes (10,11,12,13) each 500 ms. 4333 4334 => mwc.l 100 12345678 10 4335 This command will write 12345678 to address 100 all 10 ms. 4336 4337 This only takes effect if the memory commands are activated 4338 globally (CONFIG_CMD_MEM). 4339 4340- CONFIG_SKIP_LOWLEVEL_INIT 4341 [ARM, NDS32, MIPS only] If this variable is defined, then certain 4342 low level initializations (like setting up the memory 4343 controller) are omitted and/or U-Boot does not 4344 relocate itself into RAM. 4345 4346 Normally this variable MUST NOT be defined. The only 4347 exception is when U-Boot is loaded (to RAM) by some 4348 other boot loader or by a debugger which performs 4349 these initializations itself. 4350 4351- CONFIG_SKIP_LOWLEVEL_INIT_ONLY 4352 [ARM926EJ-S only] This allows just the call to lowlevel_init() 4353 to be skipped. The normal CP15 init (such as enabling the 4354 instruction cache) is still performed. 4355 4356- CONFIG_SPL_BUILD 4357 Modifies the behaviour of start.S when compiling a loader 4358 that is executed before the actual U-Boot. E.g. when 4359 compiling a NAND SPL. 4360 4361- CONFIG_TPL_BUILD 4362 Modifies the behaviour of start.S when compiling a loader 4363 that is executed after the SPL and before the actual U-Boot. 4364 It is loaded by the SPL. 4365 4366- CONFIG_SYS_MPC85XX_NO_RESETVEC 4367 Only for 85xx systems. If this variable is specified, the section 4368 .resetvec is not kept and the section .bootpg is placed in the 4369 previous 4k of the .text section. 4370 4371- CONFIG_ARCH_MAP_SYSMEM 4372 Generally U-Boot (and in particular the md command) uses 4373 effective address. It is therefore not necessary to regard 4374 U-Boot address as virtual addresses that need to be translated 4375 to physical addresses. However, sandbox requires this, since 4376 it maintains its own little RAM buffer which contains all 4377 addressable memory. This option causes some memory accesses 4378 to be mapped through map_sysmem() / unmap_sysmem(). 4379 4380- CONFIG_X86_RESET_VECTOR 4381 If defined, the x86 reset vector code is included. This is not 4382 needed when U-Boot is running from Coreboot. 4383 4384- CONFIG_SPL_AM33XX_ENABLE_RTC32K_OSC: 4385 Enables the RTC32K OSC on AM33xx based plattforms 4386 4387- CONFIG_SYS_NAND_NO_SUBPAGE_WRITE 4388 Option to disable subpage write in NAND driver 4389 driver that uses this: 4390 drivers/mtd/nand/davinci_nand.c 4391 4392Freescale QE/FMAN Firmware Support: 4393----------------------------------- 4394 4395The Freescale QUICCEngine (QE) and Frame Manager (FMAN) both support the 4396loading of "firmware", which is encoded in the QE firmware binary format. 4397This firmware often needs to be loaded during U-Boot booting, so macros 4398are used to identify the storage device (NOR flash, SPI, etc) and the address 4399within that device. 4400 4401- CONFIG_SYS_FMAN_FW_ADDR 4402 The address in the storage device where the FMAN microcode is located. The 4403 meaning of this address depends on which CONFIG_SYS_QE_FW_IN_xxx macro 4404 is also specified. 4405 4406- CONFIG_SYS_QE_FW_ADDR 4407 The address in the storage device where the QE microcode is located. The 4408 meaning of this address depends on which CONFIG_SYS_QE_FW_IN_xxx macro 4409 is also specified. 4410 4411- CONFIG_SYS_QE_FMAN_FW_LENGTH 4412 The maximum possible size of the firmware. The firmware binary format 4413 has a field that specifies the actual size of the firmware, but it 4414 might not be possible to read any part of the firmware unless some 4415 local storage is allocated to hold the entire firmware first. 4416 4417- CONFIG_SYS_QE_FMAN_FW_IN_NOR 4418 Specifies that QE/FMAN firmware is located in NOR flash, mapped as 4419 normal addressable memory via the LBC. CONFIG_SYS_FMAN_FW_ADDR is the 4420 virtual address in NOR flash. 4421 4422- CONFIG_SYS_QE_FMAN_FW_IN_NAND 4423 Specifies that QE/FMAN firmware is located in NAND flash. 4424 CONFIG_SYS_FMAN_FW_ADDR is the offset within NAND flash. 4425 4426- CONFIG_SYS_QE_FMAN_FW_IN_MMC 4427 Specifies that QE/FMAN firmware is located on the primary SD/MMC 4428 device. CONFIG_SYS_FMAN_FW_ADDR is the byte offset on that device. 4429 4430- CONFIG_SYS_QE_FMAN_FW_IN_REMOTE 4431 Specifies that QE/FMAN firmware is located in the remote (master) 4432 memory space. CONFIG_SYS_FMAN_FW_ADDR is a virtual address which 4433 can be mapped from slave TLB->slave LAW->slave SRIO or PCIE outbound 4434 window->master inbound window->master LAW->the ucode address in 4435 master's memory space. 4436 4437Freescale Layerscape Management Complex Firmware Support: 4438--------------------------------------------------------- 4439The Freescale Layerscape Management Complex (MC) supports the loading of 4440"firmware". 4441This firmware often needs to be loaded during U-Boot booting, so macros 4442are used to identify the storage device (NOR flash, SPI, etc) and the address 4443within that device. 4444 4445- CONFIG_FSL_MC_ENET 4446 Enable the MC driver for Layerscape SoCs. 4447 4448Freescale Layerscape Debug Server Support: 4449------------------------------------------- 4450The Freescale Layerscape Debug Server Support supports the loading of 4451"Debug Server firmware" and triggering SP boot-rom. 4452This firmware often needs to be loaded during U-Boot booting. 4453 4454- CONFIG_SYS_MC_RSV_MEM_ALIGN 4455 Define alignment of reserved memory MC requires 4456 4457Reproducible builds 4458------------------- 4459 4460In order to achieve reproducible builds, timestamps used in the U-Boot build 4461process have to be set to a fixed value. 4462 4463This is done using the SOURCE_DATE_EPOCH environment variable. 4464SOURCE_DATE_EPOCH is to be set on the build host's shell, not as a configuration 4465option for U-Boot or an environment variable in U-Boot. 4466 4467SOURCE_DATE_EPOCH should be set to a number of seconds since the epoch, in UTC. 4468 4469Building the Software: 4470====================== 4471 4472Building U-Boot has been tested in several native build environments 4473and in many different cross environments. Of course we cannot support 4474all possibly existing versions of cross development tools in all 4475(potentially obsolete) versions. In case of tool chain problems we 4476recommend to use the ELDK (see http://www.denx.de/wiki/DULG/ELDK) 4477which is extensively used to build and test U-Boot. 4478 4479If you are not using a native environment, it is assumed that you 4480have GNU cross compiling tools available in your path. In this case, 4481you must set the environment variable CROSS_COMPILE in your shell. 4482Note that no changes to the Makefile or any other source files are 4483necessary. For example using the ELDK on a 4xx CPU, please enter: 4484 4485 $ CROSS_COMPILE=ppc_4xx- 4486 $ export CROSS_COMPILE 4487 4488Note: If you wish to generate Windows versions of the utilities in 4489 the tools directory you can use the MinGW toolchain 4490 (http://www.mingw.org). Set your HOST tools to the MinGW 4491 toolchain and execute 'make tools'. For example: 4492 4493 $ make HOSTCC=i586-mingw32msvc-gcc HOSTSTRIP=i586-mingw32msvc-strip tools 4494 4495 Binaries such as tools/mkimage.exe will be created which can 4496 be executed on computers running Windows. 4497 4498U-Boot is intended to be simple to build. After installing the 4499sources you must configure U-Boot for one specific board type. This 4500is done by typing: 4501 4502 make NAME_defconfig 4503 4504where "NAME_defconfig" is the name of one of the existing configu- 4505rations; see boards.cfg for supported names. 4506 4507Note: for some board special configuration names may exist; check if 4508 additional information is available from the board vendor; for 4509 instance, the TQM823L systems are available without (standard) 4510 or with LCD support. You can select such additional "features" 4511 when choosing the configuration, i. e. 4512 4513 make TQM823L_defconfig 4514 - will configure for a plain TQM823L, i. e. no LCD support 4515 4516 make TQM823L_LCD_defconfig 4517 - will configure for a TQM823L with U-Boot console on LCD 4518 4519 etc. 4520 4521 4522Finally, type "make all", and you should get some working U-Boot 4523images ready for download to / installation on your system: 4524 4525- "u-boot.bin" is a raw binary image 4526- "u-boot" is an image in ELF binary format 4527- "u-boot.srec" is in Motorola S-Record format 4528 4529By default the build is performed locally and the objects are saved 4530in the source directory. One of the two methods can be used to change 4531this behavior and build U-Boot to some external directory: 4532 45331. Add O= to the make command line invocations: 4534 4535 make O=/tmp/build distclean 4536 make O=/tmp/build NAME_defconfig 4537 make O=/tmp/build all 4538 45392. Set environment variable KBUILD_OUTPUT to point to the desired location: 4540 4541 export KBUILD_OUTPUT=/tmp/build 4542 make distclean 4543 make NAME_defconfig 4544 make all 4545 4546Note that the command line "O=" setting overrides the KBUILD_OUTPUT environment 4547variable. 4548 4549 4550Please be aware that the Makefiles assume you are using GNU make, so 4551for instance on NetBSD you might need to use "gmake" instead of 4552native "make". 4553 4554 4555If the system board that you have is not listed, then you will need 4556to port U-Boot to your hardware platform. To do this, follow these 4557steps: 4558 45591. Create a new directory to hold your board specific code. Add any 4560 files you need. In your board directory, you will need at least 4561 the "Makefile" and a "<board>.c". 45622. Create a new configuration file "include/configs/<board>.h" for 4563 your board. 45643. If you're porting U-Boot to a new CPU, then also create a new 4565 directory to hold your CPU specific code. Add any files you need. 45664. Run "make <board>_defconfig" with your new name. 45675. Type "make", and you should get a working "u-boot.srec" file 4568 to be installed on your target system. 45696. Debug and solve any problems that might arise. 4570 [Of course, this last step is much harder than it sounds.] 4571 4572 4573Testing of U-Boot Modifications, Ports to New Hardware, etc.: 4574============================================================== 4575 4576If you have modified U-Boot sources (for instance added a new board 4577or support for new devices, a new CPU, etc.) you are expected to 4578provide feedback to the other developers. The feedback normally takes 4579the form of a "patch", i. e. a context diff against a certain (latest 4580official or latest in the git repository) version of U-Boot sources. 4581 4582But before you submit such a patch, please verify that your modifi- 4583cation did not break existing code. At least make sure that *ALL* of 4584the supported boards compile WITHOUT ANY compiler warnings. To do so, 4585just run the buildman script (tools/buildman/buildman), which will 4586configure and build U-Boot for ALL supported system. Be warned, this 4587will take a while. Please see the buildman README, or run 'buildman -H' 4588for documentation. 4589 4590 4591See also "U-Boot Porting Guide" below. 4592 4593 4594Monitor Commands - Overview: 4595============================ 4596 4597go - start application at address 'addr' 4598run - run commands in an environment variable 4599bootm - boot application image from memory 4600bootp - boot image via network using BootP/TFTP protocol 4601bootz - boot zImage from memory 4602tftpboot- boot image via network using TFTP protocol 4603 and env variables "ipaddr" and "serverip" 4604 (and eventually "gatewayip") 4605tftpput - upload a file via network using TFTP protocol 4606rarpboot- boot image via network using RARP/TFTP protocol 4607diskboot- boot from IDE devicebootd - boot default, i.e., run 'bootcmd' 4608loads - load S-Record file over serial line 4609loadb - load binary file over serial line (kermit mode) 4610md - memory display 4611mm - memory modify (auto-incrementing) 4612nm - memory modify (constant address) 4613mw - memory write (fill) 4614cp - memory copy 4615cmp - memory compare 4616crc32 - checksum calculation 4617i2c - I2C sub-system 4618sspi - SPI utility commands 4619base - print or set address offset 4620printenv- print environment variables 4621setenv - set environment variables 4622saveenv - save environment variables to persistent storage 4623protect - enable or disable FLASH write protection 4624erase - erase FLASH memory 4625flinfo - print FLASH memory information 4626nand - NAND memory operations (see doc/README.nand) 4627bdinfo - print Board Info structure 4628iminfo - print header information for application image 4629coninfo - print console devices and informations 4630ide - IDE sub-system 4631loop - infinite loop on address range 4632loopw - infinite write loop on address range 4633mtest - simple RAM test 4634icache - enable or disable instruction cache 4635dcache - enable or disable data cache 4636reset - Perform RESET of the CPU 4637echo - echo args to console 4638version - print monitor version 4639help - print online help 4640? - alias for 'help' 4641 4642 4643Monitor Commands - Detailed Description: 4644======================================== 4645 4646TODO. 4647 4648For now: just type "help <command>". 4649 4650 4651Environment Variables: 4652====================== 4653 4654U-Boot supports user configuration using Environment Variables which 4655can be made persistent by saving to Flash memory. 4656 4657Environment Variables are set using "setenv", printed using 4658"printenv", and saved to Flash using "saveenv". Using "setenv" 4659without a value can be used to delete a variable from the 4660environment. As long as you don't save the environment you are 4661working with an in-memory copy. In case the Flash area containing the 4662environment is erased by accident, a default environment is provided. 4663 4664Some configuration options can be set using Environment Variables. 4665 4666List of environment variables (most likely not complete): 4667 4668 baudrate - see CONFIG_BAUDRATE 4669 4670 bootdelay - see CONFIG_BOOTDELAY 4671 4672 bootcmd - see CONFIG_BOOTCOMMAND 4673 4674 bootargs - Boot arguments when booting an RTOS image 4675 4676 bootfile - Name of the image to load with TFTP 4677 4678 bootm_low - Memory range available for image processing in the bootm 4679 command can be restricted. This variable is given as 4680 a hexadecimal number and defines lowest address allowed 4681 for use by the bootm command. See also "bootm_size" 4682 environment variable. Address defined by "bootm_low" is 4683 also the base of the initial memory mapping for the Linux 4684 kernel -- see the description of CONFIG_SYS_BOOTMAPSZ and 4685 bootm_mapsize. 4686 4687 bootm_mapsize - Size of the initial memory mapping for the Linux kernel. 4688 This variable is given as a hexadecimal number and it 4689 defines the size of the memory region starting at base 4690 address bootm_low that is accessible by the Linux kernel 4691 during early boot. If unset, CONFIG_SYS_BOOTMAPSZ is used 4692 as the default value if it is defined, and bootm_size is 4693 used otherwise. 4694 4695 bootm_size - Memory range available for image processing in the bootm 4696 command can be restricted. This variable is given as 4697 a hexadecimal number and defines the size of the region 4698 allowed for use by the bootm command. See also "bootm_low" 4699 environment variable. 4700 4701 updatefile - Location of the software update file on a TFTP server, used 4702 by the automatic software update feature. Please refer to 4703 documentation in doc/README.update for more details. 4704 4705 autoload - if set to "no" (any string beginning with 'n'), 4706 "bootp" will just load perform a lookup of the 4707 configuration from the BOOTP server, but not try to 4708 load any image using TFTP 4709 4710 autostart - if set to "yes", an image loaded using the "bootp", 4711 "rarpboot", "tftpboot" or "diskboot" commands will 4712 be automatically started (by internally calling 4713 "bootm") 4714 4715 If set to "no", a standalone image passed to the 4716 "bootm" command will be copied to the load address 4717 (and eventually uncompressed), but NOT be started. 4718 This can be used to load and uncompress arbitrary 4719 data. 4720 4721 fdt_high - if set this restricts the maximum address that the 4722 flattened device tree will be copied into upon boot. 4723 For example, if you have a system with 1 GB memory 4724 at physical address 0x10000000, while Linux kernel 4725 only recognizes the first 704 MB as low memory, you 4726 may need to set fdt_high as 0x3C000000 to have the 4727 device tree blob be copied to the maximum address 4728 of the 704 MB low memory, so that Linux kernel can 4729 access it during the boot procedure. 4730 4731 If this is set to the special value 0xFFFFFFFF then 4732 the fdt will not be copied at all on boot. For this 4733 to work it must reside in writable memory, have 4734 sufficient padding on the end of it for u-boot to 4735 add the information it needs into it, and the memory 4736 must be accessible by the kernel. 4737 4738 fdtcontroladdr- if set this is the address of the control flattened 4739 device tree used by U-Boot when CONFIG_OF_CONTROL is 4740 defined. 4741 4742 i2cfast - (PPC405GP|PPC405EP only) 4743 if set to 'y' configures Linux I2C driver for fast 4744 mode (400kHZ). This environment variable is used in 4745 initialization code. So, for changes to be effective 4746 it must be saved and board must be reset. 4747 4748 initrd_high - restrict positioning of initrd images: 4749 If this variable is not set, initrd images will be 4750 copied to the highest possible address in RAM; this 4751 is usually what you want since it allows for 4752 maximum initrd size. If for some reason you want to 4753 make sure that the initrd image is loaded below the 4754 CONFIG_SYS_BOOTMAPSZ limit, you can set this environment 4755 variable to a value of "no" or "off" or "0". 4756 Alternatively, you can set it to a maximum upper 4757 address to use (U-Boot will still check that it 4758 does not overwrite the U-Boot stack and data). 4759 4760 For instance, when you have a system with 16 MB 4761 RAM, and want to reserve 4 MB from use by Linux, 4762 you can do this by adding "mem=12M" to the value of 4763 the "bootargs" variable. However, now you must make 4764 sure that the initrd image is placed in the first 4765 12 MB as well - this can be done with 4766 4767 setenv initrd_high 00c00000 4768 4769 If you set initrd_high to 0xFFFFFFFF, this is an 4770 indication to U-Boot that all addresses are legal 4771 for the Linux kernel, including addresses in flash 4772 memory. In this case U-Boot will NOT COPY the 4773 ramdisk at all. This may be useful to reduce the 4774 boot time on your system, but requires that this 4775 feature is supported by your Linux kernel. 4776 4777 ipaddr - IP address; needed for tftpboot command 4778 4779 loadaddr - Default load address for commands like "bootp", 4780 "rarpboot", "tftpboot", "loadb" or "diskboot" 4781 4782 loads_echo - see CONFIG_LOADS_ECHO 4783 4784 serverip - TFTP server IP address; needed for tftpboot command 4785 4786 bootretry - see CONFIG_BOOT_RETRY_TIME 4787 4788 bootdelaykey - see CONFIG_AUTOBOOT_DELAY_STR 4789 4790 bootstopkey - see CONFIG_AUTOBOOT_STOP_STR 4791 4792 ethprime - controls which interface is used first. 4793 4794 ethact - controls which interface is currently active. 4795 For example you can do the following 4796 4797 => setenv ethact FEC 4798 => ping 192.168.0.1 # traffic sent on FEC 4799 => setenv ethact SCC 4800 => ping 10.0.0.1 # traffic sent on SCC 4801 4802 ethrotate - When set to "no" U-Boot does not go through all 4803 available network interfaces. 4804 It just stays at the currently selected interface. 4805 4806 netretry - When set to "no" each network operation will 4807 either succeed or fail without retrying. 4808 When set to "once" the network operation will 4809 fail when all the available network interfaces 4810 are tried once without success. 4811 Useful on scripts which control the retry operation 4812 themselves. 4813 4814 npe_ucode - set load address for the NPE microcode 4815 4816 silent_linux - If set then Linux will be told to boot silently, by 4817 changing the console to be empty. If "yes" it will be 4818 made silent. If "no" it will not be made silent. If 4819 unset, then it will be made silent if the U-Boot console 4820 is silent. 4821 4822 tftpsrcp - If this is set, the value is used for TFTP's 4823 UDP source port. 4824 4825 tftpdstp - If this is set, the value is used for TFTP's UDP 4826 destination port instead of the Well Know Port 69. 4827 4828 tftpblocksize - Block size to use for TFTP transfers; if not set, 4829 we use the TFTP server's default block size 4830 4831 tftptimeout - Retransmission timeout for TFTP packets (in milli- 4832 seconds, minimum value is 1000 = 1 second). Defines 4833 when a packet is considered to be lost so it has to 4834 be retransmitted. The default is 5000 = 5 seconds. 4835 Lowering this value may make downloads succeed 4836 faster in networks with high packet loss rates or 4837 with unreliable TFTP servers. 4838 4839 tftptimeoutcountmax - maximum count of TFTP timeouts (no 4840 unit, minimum value = 0). Defines how many timeouts 4841 can happen during a single file transfer before that 4842 transfer is aborted. The default is 10, and 0 means 4843 'no timeouts allowed'. Increasing this value may help 4844 downloads succeed with high packet loss rates, or with 4845 unreliable TFTP servers or client hardware. 4846 4847 vlan - When set to a value < 4095 the traffic over 4848 Ethernet is encapsulated/received over 802.1q 4849 VLAN tagged frames. 4850 4851 bootpretryperiod - Period during which BOOTP/DHCP sends retries. 4852 Unsigned value, in milliseconds. If not set, the period will 4853 be either the default (28000), or a value based on 4854 CONFIG_NET_RETRY_COUNT, if defined. This value has 4855 precedence over the valu based on CONFIG_NET_RETRY_COUNT. 4856 4857The following image location variables contain the location of images 4858used in booting. The "Image" column gives the role of the image and is 4859not an environment variable name. The other columns are environment 4860variable names. "File Name" gives the name of the file on a TFTP 4861server, "RAM Address" gives the location in RAM the image will be 4862loaded to, and "Flash Location" gives the image's address in NOR 4863flash or offset in NAND flash. 4864 4865*Note* - these variables don't have to be defined for all boards, some 4866boards currently use other variables for these purposes, and some 4867boards use these variables for other purposes. 4868 4869Image File Name RAM Address Flash Location 4870----- --------- ----------- -------------- 4871u-boot u-boot u-boot_addr_r u-boot_addr 4872Linux kernel bootfile kernel_addr_r kernel_addr 4873device tree blob fdtfile fdt_addr_r fdt_addr 4874ramdisk ramdiskfile ramdisk_addr_r ramdisk_addr 4875 4876The following environment variables may be used and automatically 4877updated by the network boot commands ("bootp" and "rarpboot"), 4878depending the information provided by your boot server: 4879 4880 bootfile - see above 4881 dnsip - IP address of your Domain Name Server 4882 dnsip2 - IP address of your secondary Domain Name Server 4883 gatewayip - IP address of the Gateway (Router) to use 4884 hostname - Target hostname 4885 ipaddr - see above 4886 netmask - Subnet Mask 4887 rootpath - Pathname of the root filesystem on the NFS server 4888 serverip - see above 4889 4890 4891There are two special Environment Variables: 4892 4893 serial# - contains hardware identification information such 4894 as type string and/or serial number 4895 ethaddr - Ethernet address 4896 4897These variables can be set only once (usually during manufacturing of 4898the board). U-Boot refuses to delete or overwrite these variables 4899once they have been set once. 4900 4901 4902Further special Environment Variables: 4903 4904 ver - Contains the U-Boot version string as printed 4905 with the "version" command. This variable is 4906 readonly (see CONFIG_VERSION_VARIABLE). 4907 4908 4909Please note that changes to some configuration parameters may take 4910only effect after the next boot (yes, that's just like Windoze :-). 4911 4912 4913Callback functions for environment variables: 4914--------------------------------------------- 4915 4916For some environment variables, the behavior of u-boot needs to change 4917when their values are changed. This functionality allows functions to 4918be associated with arbitrary variables. On creation, overwrite, or 4919deletion, the callback will provide the opportunity for some side 4920effect to happen or for the change to be rejected. 4921 4922The callbacks are named and associated with a function using the 4923U_BOOT_ENV_CALLBACK macro in your board or driver code. 4924 4925These callbacks are associated with variables in one of two ways. The 4926static list can be added to by defining CONFIG_ENV_CALLBACK_LIST_STATIC 4927in the board configuration to a string that defines a list of 4928associations. The list must be in the following format: 4929 4930 entry = variable_name[:callback_name] 4931 list = entry[,list] 4932 4933If the callback name is not specified, then the callback is deleted. 4934Spaces are also allowed anywhere in the list. 4935 4936Callbacks can also be associated by defining the ".callbacks" variable 4937with the same list format above. Any association in ".callbacks" will 4938override any association in the static list. You can define 4939CONFIG_ENV_CALLBACK_LIST_DEFAULT to a list (string) to define the 4940".callbacks" environment variable in the default or embedded environment. 4941 4942If CONFIG_REGEX is defined, the variable_name above is evaluated as a 4943regular expression. This allows multiple variables to be connected to 4944the same callback without explicitly listing them all out. 4945 4946 4947Command Line Parsing: 4948===================== 4949 4950There are two different command line parsers available with U-Boot: 4951the old "simple" one, and the much more powerful "hush" shell: 4952 4953Old, simple command line parser: 4954-------------------------------- 4955 4956- supports environment variables (through setenv / saveenv commands) 4957- several commands on one line, separated by ';' 4958- variable substitution using "... ${name} ..." syntax 4959- special characters ('$', ';') can be escaped by prefixing with '\', 4960 for example: 4961 setenv bootcmd bootm \${address} 4962- You can also escape text by enclosing in single apostrophes, for example: 4963 setenv addip 'setenv bootargs $bootargs ip=$ipaddr:$serverip:$gatewayip:$netmask:$hostname::off' 4964 4965Hush shell: 4966----------- 4967 4968- similar to Bourne shell, with control structures like 4969 if...then...else...fi, for...do...done; while...do...done, 4970 until...do...done, ... 4971- supports environment ("global") variables (through setenv / saveenv 4972 commands) and local shell variables (through standard shell syntax 4973 "name=value"); only environment variables can be used with "run" 4974 command 4975 4976General rules: 4977-------------- 4978 4979(1) If a command line (or an environment variable executed by a "run" 4980 command) contains several commands separated by semicolon, and 4981 one of these commands fails, then the remaining commands will be 4982 executed anyway. 4983 4984(2) If you execute several variables with one call to run (i. e. 4985 calling run with a list of variables as arguments), any failing 4986 command will cause "run" to terminate, i. e. the remaining 4987 variables are not executed. 4988 4989Note for Redundant Ethernet Interfaces: 4990======================================= 4991 4992Some boards come with redundant Ethernet interfaces; U-Boot supports 4993such configurations and is capable of automatic selection of a 4994"working" interface when needed. MAC assignment works as follows: 4995 4996Network interfaces are numbered eth0, eth1, eth2, ... Corresponding 4997MAC addresses can be stored in the environment as "ethaddr" (=>eth0), 4998"eth1addr" (=>eth1), "eth2addr", ... 4999 5000If the network interface stores some valid MAC address (for instance 5001in SROM), this is used as default address if there is NO correspon- 5002ding setting in the environment; if the corresponding environment 5003variable is set, this overrides the settings in the card; that means: 5004 5005o If the SROM has a valid MAC address, and there is no address in the 5006 environment, the SROM's address is used. 5007 5008o If there is no valid address in the SROM, and a definition in the 5009 environment exists, then the value from the environment variable is 5010 used. 5011 5012o If both the SROM and the environment contain a MAC address, and 5013 both addresses are the same, this MAC address is used. 5014 5015o If both the SROM and the environment contain a MAC address, and the 5016 addresses differ, the value from the environment is used and a 5017 warning is printed. 5018 5019o If neither SROM nor the environment contain a MAC address, an error 5020 is raised. If CONFIG_NET_RANDOM_ETHADDR is defined, then in this case 5021 a random, locally-assigned MAC is used. 5022 5023If Ethernet drivers implement the 'write_hwaddr' function, valid MAC addresses 5024will be programmed into hardware as part of the initialization process. This 5025may be skipped by setting the appropriate 'ethmacskip' environment variable. 5026The naming convention is as follows: 5027"ethmacskip" (=>eth0), "eth1macskip" (=>eth1) etc. 5028 5029Image Formats: 5030============== 5031 5032U-Boot is capable of booting (and performing other auxiliary operations on) 5033images in two formats: 5034 5035New uImage format (FIT) 5036----------------------- 5037 5038Flexible and powerful format based on Flattened Image Tree -- FIT (similar 5039to Flattened Device Tree). It allows the use of images with multiple 5040components (several kernels, ramdisks, etc.), with contents protected by 5041SHA1, MD5 or CRC32. More details are found in the doc/uImage.FIT directory. 5042 5043 5044Old uImage format 5045----------------- 5046 5047Old image format is based on binary files which can be basically anything, 5048preceded by a special header; see the definitions in include/image.h for 5049details; basically, the header defines the following image properties: 5050 5051* Target Operating System (Provisions for OpenBSD, NetBSD, FreeBSD, 5052 4.4BSD, Linux, SVR4, Esix, Solaris, Irix, SCO, Dell, NCR, VxWorks, 5053 LynxOS, pSOS, QNX, RTEMS, INTEGRITY; 5054 Currently supported: Linux, NetBSD, VxWorks, QNX, RTEMS, LynxOS, 5055 INTEGRITY). 5056* Target CPU Architecture (Provisions for Alpha, ARM, AVR32, Intel x86, 5057 IA64, MIPS, NDS32, Nios II, PowerPC, IBM S390, SuperH, Sparc, Sparc 64 Bit; 5058 Currently supported: ARM, AVR32, Intel x86, MIPS, NDS32, Nios II, PowerPC). 5059* Compression Type (uncompressed, gzip, bzip2) 5060* Load Address 5061* Entry Point 5062* Image Name 5063* Image Timestamp 5064 5065The header is marked by a special Magic Number, and both the header 5066and the data portions of the image are secured against corruption by 5067CRC32 checksums. 5068 5069 5070Linux Support: 5071============== 5072 5073Although U-Boot should support any OS or standalone application 5074easily, the main focus has always been on Linux during the design of 5075U-Boot. 5076 5077U-Boot includes many features that so far have been part of some 5078special "boot loader" code within the Linux kernel. Also, any 5079"initrd" images to be used are no longer part of one big Linux image; 5080instead, kernel and "initrd" are separate images. This implementation 5081serves several purposes: 5082 5083- the same features can be used for other OS or standalone 5084 applications (for instance: using compressed images to reduce the 5085 Flash memory footprint) 5086 5087- it becomes much easier to port new Linux kernel versions because 5088 lots of low-level, hardware dependent stuff are done by U-Boot 5089 5090- the same Linux kernel image can now be used with different "initrd" 5091 images; of course this also means that different kernel images can 5092 be run with the same "initrd". This makes testing easier (you don't 5093 have to build a new "zImage.initrd" Linux image when you just 5094 change a file in your "initrd"). Also, a field-upgrade of the 5095 software is easier now. 5096 5097 5098Linux HOWTO: 5099============ 5100 5101Porting Linux to U-Boot based systems: 5102--------------------------------------- 5103 5104U-Boot cannot save you from doing all the necessary modifications to 5105configure the Linux device drivers for use with your target hardware 5106(no, we don't intend to provide a full virtual machine interface to 5107Linux :-). 5108 5109But now you can ignore ALL boot loader code (in arch/powerpc/mbxboot). 5110 5111Just make sure your machine specific header file (for instance 5112include/asm-ppc/tqm8xx.h) includes the same definition of the Board 5113Information structure as we define in include/asm-<arch>/u-boot.h, 5114and make sure that your definition of IMAP_ADDR uses the same value 5115as your U-Boot configuration in CONFIG_SYS_IMMR. 5116 5117Note that U-Boot now has a driver model, a unified model for drivers. 5118If you are adding a new driver, plumb it into driver model. If there 5119is no uclass available, you are encouraged to create one. See 5120doc/driver-model. 5121 5122 5123Configuring the Linux kernel: 5124----------------------------- 5125 5126No specific requirements for U-Boot. Make sure you have some root 5127device (initial ramdisk, NFS) for your target system. 5128 5129 5130Building a Linux Image: 5131----------------------- 5132 5133With U-Boot, "normal" build targets like "zImage" or "bzImage" are 5134not used. If you use recent kernel source, a new build target 5135"uImage" will exist which automatically builds an image usable by 5136U-Boot. Most older kernels also have support for a "pImage" target, 5137which was introduced for our predecessor project PPCBoot and uses a 5138100% compatible format. 5139 5140Example: 5141 5142 make TQM850L_defconfig 5143 make oldconfig 5144 make dep 5145 make uImage 5146 5147The "uImage" build target uses a special tool (in 'tools/mkimage') to 5148encapsulate a compressed Linux kernel image with header information, 5149CRC32 checksum etc. for use with U-Boot. This is what we are doing: 5150 5151* build a standard "vmlinux" kernel image (in ELF binary format): 5152 5153* convert the kernel into a raw binary image: 5154 5155 ${CROSS_COMPILE}-objcopy -O binary \ 5156 -R .note -R .comment \ 5157 -S vmlinux linux.bin 5158 5159* compress the binary image: 5160 5161 gzip -9 linux.bin 5162 5163* package compressed binary image for U-Boot: 5164 5165 mkimage -A ppc -O linux -T kernel -C gzip \ 5166 -a 0 -e 0 -n "Linux Kernel Image" \ 5167 -d linux.bin.gz uImage 5168 5169 5170The "mkimage" tool can also be used to create ramdisk images for use 5171with U-Boot, either separated from the Linux kernel image, or 5172combined into one file. "mkimage" encapsulates the images with a 64 5173byte header containing information about target architecture, 5174operating system, image type, compression method, entry points, time 5175stamp, CRC32 checksums, etc. 5176 5177"mkimage" can be called in two ways: to verify existing images and 5178print the header information, or to build new images. 5179 5180In the first form (with "-l" option) mkimage lists the information 5181contained in the header of an existing U-Boot image; this includes 5182checksum verification: 5183 5184 tools/mkimage -l image 5185 -l ==> list image header information 5186 5187The second form (with "-d" option) is used to build a U-Boot image 5188from a "data file" which is used as image payload: 5189 5190 tools/mkimage -A arch -O os -T type -C comp -a addr -e ep \ 5191 -n name -d data_file image 5192 -A ==> set architecture to 'arch' 5193 -O ==> set operating system to 'os' 5194 -T ==> set image type to 'type' 5195 -C ==> set compression type 'comp' 5196 -a ==> set load address to 'addr' (hex) 5197 -e ==> set entry point to 'ep' (hex) 5198 -n ==> set image name to 'name' 5199 -d ==> use image data from 'datafile' 5200 5201Right now, all Linux kernels for PowerPC systems use the same load 5202address (0x00000000), but the entry point address depends on the 5203kernel version: 5204 5205- 2.2.x kernels have the entry point at 0x0000000C, 5206- 2.3.x and later kernels have the entry point at 0x00000000. 5207 5208So a typical call to build a U-Boot image would read: 5209 5210 -> tools/mkimage -n '2.4.4 kernel for TQM850L' \ 5211 > -A ppc -O linux -T kernel -C gzip -a 0 -e 0 \ 5212 > -d /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/powerpc/coffboot/vmlinux.gz \ 5213 > examples/uImage.TQM850L 5214 Image Name: 2.4.4 kernel for TQM850L 5215 Created: Wed Jul 19 02:34:59 2000 5216 Image Type: PowerPC Linux Kernel Image (gzip compressed) 5217 Data Size: 335725 Bytes = 327.86 kB = 0.32 MB 5218 Load Address: 0x00000000 5219 Entry Point: 0x00000000 5220 5221To verify the contents of the image (or check for corruption): 5222 5223 -> tools/mkimage -l examples/uImage.TQM850L 5224 Image Name: 2.4.4 kernel for TQM850L 5225 Created: Wed Jul 19 02:34:59 2000 5226 Image Type: PowerPC Linux Kernel Image (gzip compressed) 5227 Data Size: 335725 Bytes = 327.86 kB = 0.32 MB 5228 Load Address: 0x00000000 5229 Entry Point: 0x00000000 5230 5231NOTE: for embedded systems where boot time is critical you can trade 5232speed for memory and install an UNCOMPRESSED image instead: this 5233needs more space in Flash, but boots much faster since it does not 5234need to be uncompressed: 5235 5236 -> gunzip /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/powerpc/coffboot/vmlinux.gz 5237 -> tools/mkimage -n '2.4.4 kernel for TQM850L' \ 5238 > -A ppc -O linux -T kernel -C none -a 0 -e 0 \ 5239 > -d /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/powerpc/coffboot/vmlinux \ 5240 > examples/uImage.TQM850L-uncompressed 5241 Image Name: 2.4.4 kernel for TQM850L 5242 Created: Wed Jul 19 02:34:59 2000 5243 Image Type: PowerPC Linux Kernel Image (uncompressed) 5244 Data Size: 792160 Bytes = 773.59 kB = 0.76 MB 5245 Load Address: 0x00000000 5246 Entry Point: 0x00000000 5247 5248 5249Similar you can build U-Boot images from a 'ramdisk.image.gz' file 5250when your kernel is intended to use an initial ramdisk: 5251 5252 -> tools/mkimage -n 'Simple Ramdisk Image' \ 5253 > -A ppc -O linux -T ramdisk -C gzip \ 5254 > -d /LinuxPPC/images/SIMPLE-ramdisk.image.gz examples/simple-initrd 5255 Image Name: Simple Ramdisk Image 5256 Created: Wed Jan 12 14:01:50 2000 5257 Image Type: PowerPC Linux RAMDisk Image (gzip compressed) 5258 Data Size: 566530 Bytes = 553.25 kB = 0.54 MB 5259 Load Address: 0x00000000 5260 Entry Point: 0x00000000 5261 5262The "dumpimage" is a tool to disassemble images built by mkimage. Its "-i" 5263option performs the converse operation of the mkimage's second form (the "-d" 5264option). Given an image built by mkimage, the dumpimage extracts a "data file" 5265from the image: 5266 5267 tools/dumpimage -i image -T type -p position data_file 5268 -i ==> extract from the 'image' a specific 'data_file' 5269 -T ==> set image type to 'type' 5270 -p ==> 'position' (starting at 0) of the 'data_file' inside the 'image' 5271 5272 5273Installing a Linux Image: 5274------------------------- 5275 5276To downloading a U-Boot image over the serial (console) interface, 5277you must convert the image to S-Record format: 5278 5279 objcopy -I binary -O srec examples/image examples/image.srec 5280 5281The 'objcopy' does not understand the information in the U-Boot 5282image header, so the resulting S-Record file will be relative to 5283address 0x00000000. To load it to a given address, you need to 5284specify the target address as 'offset' parameter with the 'loads' 5285command. 5286 5287Example: install the image to address 0x40100000 (which on the 5288TQM8xxL is in the first Flash bank): 5289 5290 => erase 40100000 401FFFFF 5291 5292 .......... done 5293 Erased 8 sectors 5294 5295 => loads 40100000 5296 ## Ready for S-Record download ... 5297 ~>examples/image.srec 5298 1 2 3 4 5 6 7 8 9 10 11 12 13 ... 5299 ... 5300 15989 15990 15991 15992 5301 [file transfer complete] 5302 [connected] 5303 ## Start Addr = 0x00000000 5304 5305 5306You can check the success of the download using the 'iminfo' command; 5307this includes a checksum verification so you can be sure no data 5308corruption happened: 5309 5310 => imi 40100000 5311 5312 ## Checking Image at 40100000 ... 5313 Image Name: 2.2.13 for initrd on TQM850L 5314 Image Type: PowerPC Linux Kernel Image (gzip compressed) 5315 Data Size: 335725 Bytes = 327 kB = 0 MB 5316 Load Address: 00000000 5317 Entry Point: 0000000c 5318 Verifying Checksum ... OK 5319 5320 5321Boot Linux: 5322----------- 5323 5324The "bootm" command is used to boot an application that is stored in 5325memory (RAM or Flash). In case of a Linux kernel image, the contents 5326of the "bootargs" environment variable is passed to the kernel as 5327parameters. You can check and modify this variable using the 5328"printenv" and "setenv" commands: 5329 5330 5331 => printenv bootargs 5332 bootargs=root=/dev/ram 5333 5334 => setenv bootargs root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2 5335 5336 => printenv bootargs 5337 bootargs=root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2 5338 5339 => bootm 40020000 5340 ## Booting Linux kernel at 40020000 ... 5341 Image Name: 2.2.13 for NFS on TQM850L 5342 Image Type: PowerPC Linux Kernel Image (gzip compressed) 5343 Data Size: 381681 Bytes = 372 kB = 0 MB 5344 Load Address: 00000000 5345 Entry Point: 0000000c 5346 Verifying Checksum ... OK 5347 Uncompressing Kernel Image ... OK 5348 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 5349 Boot arguments: root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2 5350 time_init: decrementer frequency = 187500000/60 5351 Calibrating delay loop... 49.77 BogoMIPS 5352 Memory: 15208k available (700k kernel code, 444k data, 32k init) [c0000000,c1000000] 5353 ... 5354 5355If you want to boot a Linux kernel with initial RAM disk, you pass 5356the memory addresses of both the kernel and the initrd image (PPBCOOT 5357format!) to the "bootm" command: 5358 5359 => imi 40100000 40200000 5360 5361 ## Checking Image at 40100000 ... 5362 Image Name: 2.2.13 for initrd on TQM850L 5363 Image Type: PowerPC Linux Kernel Image (gzip compressed) 5364 Data Size: 335725 Bytes = 327 kB = 0 MB 5365 Load Address: 00000000 5366 Entry Point: 0000000c 5367 Verifying Checksum ... OK 5368 5369 ## Checking Image at 40200000 ... 5370 Image Name: Simple Ramdisk Image 5371 Image Type: PowerPC Linux RAMDisk Image (gzip compressed) 5372 Data Size: 566530 Bytes = 553 kB = 0 MB 5373 Load Address: 00000000 5374 Entry Point: 00000000 5375 Verifying Checksum ... OK 5376 5377 => bootm 40100000 40200000 5378 ## Booting Linux kernel at 40100000 ... 5379 Image Name: 2.2.13 for initrd on TQM850L 5380 Image Type: PowerPC Linux Kernel Image (gzip compressed) 5381 Data Size: 335725 Bytes = 327 kB = 0 MB 5382 Load Address: 00000000 5383 Entry Point: 0000000c 5384 Verifying Checksum ... OK 5385 Uncompressing Kernel Image ... OK 5386 ## Loading RAMDisk Image at 40200000 ... 5387 Image Name: Simple Ramdisk Image 5388 Image Type: PowerPC Linux RAMDisk Image (gzip compressed) 5389 Data Size: 566530 Bytes = 553 kB = 0 MB 5390 Load Address: 00000000 5391 Entry Point: 00000000 5392 Verifying Checksum ... OK 5393 Loading Ramdisk ... OK 5394 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 5395 Boot arguments: root=/dev/ram 5396 time_init: decrementer frequency = 187500000/60 5397 Calibrating delay loop... 49.77 BogoMIPS 5398 ... 5399 RAMDISK: Compressed image found at block 0 5400 VFS: Mounted root (ext2 filesystem). 5401 5402 bash# 5403 5404Boot Linux and pass a flat device tree: 5405----------- 5406 5407First, U-Boot must be compiled with the appropriate defines. See the section 5408titled "Linux Kernel Interface" above for a more in depth explanation. The 5409following is an example of how to start a kernel and pass an updated 5410flat device tree: 5411 5412=> print oftaddr 5413oftaddr=0x300000 5414=> print oft 5415oft=oftrees/mpc8540ads.dtb 5416=> tftp $oftaddr $oft 5417Speed: 1000, full duplex 5418Using TSEC0 device 5419TFTP from server 192.168.1.1; our IP address is 192.168.1.101 5420Filename 'oftrees/mpc8540ads.dtb'. 5421Load address: 0x300000 5422Loading: # 5423done 5424Bytes transferred = 4106 (100a hex) 5425=> tftp $loadaddr $bootfile 5426Speed: 1000, full duplex 5427Using TSEC0 device 5428TFTP from server 192.168.1.1; our IP address is 192.168.1.2 5429Filename 'uImage'. 5430Load address: 0x200000 5431Loading:############ 5432done 5433Bytes transferred = 1029407 (fb51f hex) 5434=> print loadaddr 5435loadaddr=200000 5436=> print oftaddr 5437oftaddr=0x300000 5438=> bootm $loadaddr - $oftaddr 5439## Booting image at 00200000 ... 5440 Image Name: Linux-2.6.17-dirty 5441 Image Type: PowerPC Linux Kernel Image (gzip compressed) 5442 Data Size: 1029343 Bytes = 1005.2 kB 5443 Load Address: 00000000 5444 Entry Point: 00000000 5445 Verifying Checksum ... OK 5446 Uncompressing Kernel Image ... OK 5447Booting using flat device tree at 0x300000 5448Using MPC85xx ADS machine description 5449Memory CAM mapping: CAM0=256Mb, CAM1=256Mb, CAM2=0Mb residual: 0Mb 5450[snip] 5451 5452 5453More About U-Boot Image Types: 5454------------------------------ 5455 5456U-Boot supports the following image types: 5457 5458 "Standalone Programs" are directly runnable in the environment 5459 provided by U-Boot; it is expected that (if they behave 5460 well) you can continue to work in U-Boot after return from 5461 the Standalone Program. 5462 "OS Kernel Images" are usually images of some Embedded OS which 5463 will take over control completely. Usually these programs 5464 will install their own set of exception handlers, device 5465 drivers, set up the MMU, etc. - this means, that you cannot 5466 expect to re-enter U-Boot except by resetting the CPU. 5467 "RAMDisk Images" are more or less just data blocks, and their 5468 parameters (address, size) are passed to an OS kernel that is 5469 being started. 5470 "Multi-File Images" contain several images, typically an OS 5471 (Linux) kernel image and one or more data images like 5472 RAMDisks. This construct is useful for instance when you want 5473 to boot over the network using BOOTP etc., where the boot 5474 server provides just a single image file, but you want to get 5475 for instance an OS kernel and a RAMDisk image. 5476 5477 "Multi-File Images" start with a list of image sizes, each 5478 image size (in bytes) specified by an "uint32_t" in network 5479 byte order. This list is terminated by an "(uint32_t)0". 5480 Immediately after the terminating 0 follow the images, one by 5481 one, all aligned on "uint32_t" boundaries (size rounded up to 5482 a multiple of 4 bytes). 5483 5484 "Firmware Images" are binary images containing firmware (like 5485 U-Boot or FPGA images) which usually will be programmed to 5486 flash memory. 5487 5488 "Script files" are command sequences that will be executed by 5489 U-Boot's command interpreter; this feature is especially 5490 useful when you configure U-Boot to use a real shell (hush) 5491 as command interpreter. 5492 5493Booting the Linux zImage: 5494------------------------- 5495 5496On some platforms, it's possible to boot Linux zImage. This is done 5497using the "bootz" command. The syntax of "bootz" command is the same 5498as the syntax of "bootm" command. 5499 5500Note, defining the CONFIG_SUPPORT_RAW_INITRD allows user to supply 5501kernel with raw initrd images. The syntax is slightly different, the 5502address of the initrd must be augmented by it's size, in the following 5503format: "<initrd addres>:<initrd size>". 5504 5505 5506Standalone HOWTO: 5507================= 5508 5509One of the features of U-Boot is that you can dynamically load and 5510run "standalone" applications, which can use some resources of 5511U-Boot like console I/O functions or interrupt services. 5512 5513Two simple examples are included with the sources: 5514 5515"Hello World" Demo: 5516------------------- 5517 5518'examples/hello_world.c' contains a small "Hello World" Demo 5519application; it is automatically compiled when you build U-Boot. 5520It's configured to run at address 0x00040004, so you can play with it 5521like that: 5522 5523 => loads 5524 ## Ready for S-Record download ... 5525 ~>examples/hello_world.srec 5526 1 2 3 4 5 6 7 8 9 10 11 ... 5527 [file transfer complete] 5528 [connected] 5529 ## Start Addr = 0x00040004 5530 5531 => go 40004 Hello World! This is a test. 5532 ## Starting application at 0x00040004 ... 5533 Hello World 5534 argc = 7 5535 argv[0] = "40004" 5536 argv[1] = "Hello" 5537 argv[2] = "World!" 5538 argv[3] = "This" 5539 argv[4] = "is" 5540 argv[5] = "a" 5541 argv[6] = "test." 5542 argv[7] = "<NULL>" 5543 Hit any key to exit ... 5544 5545 ## Application terminated, rc = 0x0 5546 5547Another example, which demonstrates how to register a CPM interrupt 5548handler with the U-Boot code, can be found in 'examples/timer.c'. 5549Here, a CPM timer is set up to generate an interrupt every second. 5550The interrupt service routine is trivial, just printing a '.' 5551character, but this is just a demo program. The application can be 5552controlled by the following keys: 5553 5554 ? - print current values og the CPM Timer registers 5555 b - enable interrupts and start timer 5556 e - stop timer and disable interrupts 5557 q - quit application 5558 5559 => loads 5560 ## Ready for S-Record download ... 5561 ~>examples/timer.srec 5562 1 2 3 4 5 6 7 8 9 10 11 ... 5563 [file transfer complete] 5564 [connected] 5565 ## Start Addr = 0x00040004 5566 5567 => go 40004 5568 ## Starting application at 0x00040004 ... 5569 TIMERS=0xfff00980 5570 Using timer 1 5571 tgcr @ 0xfff00980, tmr @ 0xfff00990, trr @ 0xfff00994, tcr @ 0xfff00998, tcn @ 0xfff0099c, ter @ 0xfff009b0 5572 5573Hit 'b': 5574 [q, b, e, ?] Set interval 1000000 us 5575 Enabling timer 5576Hit '?': 5577 [q, b, e, ?] ........ 5578 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0xef6, ter=0x0 5579Hit '?': 5580 [q, b, e, ?] . 5581 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x2ad4, ter=0x0 5582Hit '?': 5583 [q, b, e, ?] . 5584 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x1efc, ter=0x0 5585Hit '?': 5586 [q, b, e, ?] . 5587 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x169d, ter=0x0 5588Hit 'e': 5589 [q, b, e, ?] ...Stopping timer 5590Hit 'q': 5591 [q, b, e, ?] ## Application terminated, rc = 0x0 5592 5593 5594Minicom warning: 5595================ 5596 5597Over time, many people have reported problems when trying to use the 5598"minicom" terminal emulation program for serial download. I (wd) 5599consider minicom to be broken, and recommend not to use it. Under 5600Unix, I recommend to use C-Kermit for general purpose use (and 5601especially for kermit binary protocol download ("loadb" command), and 5602use "cu" for S-Record download ("loads" command). See 5603http://www.denx.de/wiki/view/DULG/SystemSetup#Section_4.3. 5604for help with kermit. 5605 5606 5607Nevertheless, if you absolutely want to use it try adding this 5608configuration to your "File transfer protocols" section: 5609 5610 Name Program Name U/D FullScr IO-Red. Multi 5611 X kermit /usr/bin/kermit -i -l %l -s Y U Y N N 5612 Y kermit /usr/bin/kermit -i -l %l -r N D Y N N 5613 5614 5615NetBSD Notes: 5616============= 5617 5618Starting at version 0.9.2, U-Boot supports NetBSD both as host 5619(build U-Boot) and target system (boots NetBSD/mpc8xx). 5620 5621Building requires a cross environment; it is known to work on 5622NetBSD/i386 with the cross-powerpc-netbsd-1.3 package (you will also 5623need gmake since the Makefiles are not compatible with BSD make). 5624Note that the cross-powerpc package does not install include files; 5625attempting to build U-Boot will fail because <machine/ansi.h> is 5626missing. This file has to be installed and patched manually: 5627 5628 # cd /usr/pkg/cross/powerpc-netbsd/include 5629 # mkdir powerpc 5630 # ln -s powerpc machine 5631 # cp /usr/src/sys/arch/powerpc/include/ansi.h powerpc/ansi.h 5632 # ${EDIT} powerpc/ansi.h ## must remove __va_list, _BSD_VA_LIST 5633 5634Native builds *don't* work due to incompatibilities between native 5635and U-Boot include files. 5636 5637Booting assumes that (the first part of) the image booted is a 5638stage-2 loader which in turn loads and then invokes the kernel 5639proper. Loader sources will eventually appear in the NetBSD source 5640tree (probably in sys/arc/mpc8xx/stand/u-boot_stage2/); in the 5641meantime, see ftp://ftp.denx.de/pub/u-boot/ppcboot_stage2.tar.gz 5642 5643 5644Implementation Internals: 5645========================= 5646 5647The following is not intended to be a complete description of every 5648implementation detail. However, it should help to understand the 5649inner workings of U-Boot and make it easier to port it to custom 5650hardware. 5651 5652 5653Initial Stack, Global Data: 5654--------------------------- 5655 5656The implementation of U-Boot is complicated by the fact that U-Boot 5657starts running out of ROM (flash memory), usually without access to 5658system RAM (because the memory controller is not initialized yet). 5659This means that we don't have writable Data or BSS segments, and BSS 5660is not initialized as zero. To be able to get a C environment working 5661at all, we have to allocate at least a minimal stack. Implementation 5662options for this are defined and restricted by the CPU used: Some CPU 5663models provide on-chip memory (like the IMMR area on MPC8xx and 5664MPC826x processors), on others (parts of) the data cache can be 5665locked as (mis-) used as memory, etc. 5666 5667 Chris Hallinan posted a good summary of these issues to the 5668 U-Boot mailing list: 5669 5670 Subject: RE: [U-Boot-Users] RE: More On Memory Bank x (nothingness)? 5671 From: "Chris Hallinan" <clh@net1plus.com> 5672 Date: Mon, 10 Feb 2003 16:43:46 -0500 (22:43 MET) 5673 ... 5674 5675 Correct me if I'm wrong, folks, but the way I understand it 5676 is this: Using DCACHE as initial RAM for Stack, etc, does not 5677 require any physical RAM backing up the cache. The cleverness 5678 is that the cache is being used as a temporary supply of 5679 necessary storage before the SDRAM controller is setup. It's 5680 beyond the scope of this list to explain the details, but you 5681 can see how this works by studying the cache architecture and 5682 operation in the architecture and processor-specific manuals. 5683 5684 OCM is On Chip Memory, which I believe the 405GP has 4K. It 5685 is another option for the system designer to use as an 5686 initial stack/RAM area prior to SDRAM being available. Either 5687 option should work for you. Using CS 4 should be fine if your 5688 board designers haven't used it for something that would 5689 cause you grief during the initial boot! It is frequently not 5690 used. 5691 5692 CONFIG_SYS_INIT_RAM_ADDR should be somewhere that won't interfere 5693 with your processor/board/system design. The default value 5694 you will find in any recent u-boot distribution in 5695 walnut.h should work for you. I'd set it to a value larger 5696 than your SDRAM module. If you have a 64MB SDRAM module, set 5697 it above 400_0000. Just make sure your board has no resources 5698 that are supposed to respond to that address! That code in 5699 start.S has been around a while and should work as is when 5700 you get the config right. 5701 5702 -Chris Hallinan 5703 DS4.COM, Inc. 5704 5705It is essential to remember this, since it has some impact on the C 5706code for the initialization procedures: 5707 5708* Initialized global data (data segment) is read-only. Do not attempt 5709 to write it. 5710 5711* Do not use any uninitialized global data (or implicitly initialized 5712 as zero data - BSS segment) at all - this is undefined, initiali- 5713 zation is performed later (when relocating to RAM). 5714 5715* Stack space is very limited. Avoid big data buffers or things like 5716 that. 5717 5718Having only the stack as writable memory limits means we cannot use 5719normal global data to share information between the code. But it 5720turned out that the implementation of U-Boot can be greatly 5721simplified by making a global data structure (gd_t) available to all 5722functions. We could pass a pointer to this data as argument to _all_ 5723functions, but this would bloat the code. Instead we use a feature of 5724the GCC compiler (Global Register Variables) to share the data: we 5725place a pointer (gd) to the global data into a register which we 5726reserve for this purpose. 5727 5728When choosing a register for such a purpose we are restricted by the 5729relevant (E)ABI specifications for the current architecture, and by 5730GCC's implementation. 5731 5732For PowerPC, the following registers have specific use: 5733 R1: stack pointer 5734 R2: reserved for system use 5735 R3-R4: parameter passing and return values 5736 R5-R10: parameter passing 5737 R13: small data area pointer 5738 R30: GOT pointer 5739 R31: frame pointer 5740 5741 (U-Boot also uses R12 as internal GOT pointer. r12 5742 is a volatile register so r12 needs to be reset when 5743 going back and forth between asm and C) 5744 5745 ==> U-Boot will use R2 to hold a pointer to the global data 5746 5747 Note: on PPC, we could use a static initializer (since the 5748 address of the global data structure is known at compile time), 5749 but it turned out that reserving a register results in somewhat 5750 smaller code - although the code savings are not that big (on 5751 average for all boards 752 bytes for the whole U-Boot image, 5752 624 text + 127 data). 5753 5754On ARM, the following registers are used: 5755 5756 R0: function argument word/integer result 5757 R1-R3: function argument word 5758 R9: platform specific 5759 R10: stack limit (used only if stack checking is enabled) 5760 R11: argument (frame) pointer 5761 R12: temporary workspace 5762 R13: stack pointer 5763 R14: link register 5764 R15: program counter 5765 5766 ==> U-Boot will use R9 to hold a pointer to the global data 5767 5768 Note: on ARM, only R_ARM_RELATIVE relocations are supported. 5769 5770On Nios II, the ABI is documented here: 5771 http://www.altera.com/literature/hb/nios2/n2cpu_nii51016.pdf 5772 5773 ==> U-Boot will use gp to hold a pointer to the global data 5774 5775 Note: on Nios II, we give "-G0" option to gcc and don't use gp 5776 to access small data sections, so gp is free. 5777 5778On NDS32, the following registers are used: 5779 5780 R0-R1: argument/return 5781 R2-R5: argument 5782 R15: temporary register for assembler 5783 R16: trampoline register 5784 R28: frame pointer (FP) 5785 R29: global pointer (GP) 5786 R30: link register (LP) 5787 R31: stack pointer (SP) 5788 PC: program counter (PC) 5789 5790 ==> U-Boot will use R10 to hold a pointer to the global data 5791 5792NOTE: DECLARE_GLOBAL_DATA_PTR must be used with file-global scope, 5793or current versions of GCC may "optimize" the code too much. 5794 5795Memory Management: 5796------------------ 5797 5798U-Boot runs in system state and uses physical addresses, i.e. the 5799MMU is not used either for address mapping nor for memory protection. 5800 5801The available memory is mapped to fixed addresses using the memory 5802controller. In this process, a contiguous block is formed for each 5803memory type (Flash, SDRAM, SRAM), even when it consists of several 5804physical memory banks. 5805 5806U-Boot is installed in the first 128 kB of the first Flash bank (on 5807TQM8xxL modules this is the range 0x40000000 ... 0x4001FFFF). After 5808booting and sizing and initializing DRAM, the code relocates itself 5809to the upper end of DRAM. Immediately below the U-Boot code some 5810memory is reserved for use by malloc() [see CONFIG_SYS_MALLOC_LEN 5811configuration setting]. Below that, a structure with global Board 5812Info data is placed, followed by the stack (growing downward). 5813 5814Additionally, some exception handler code is copied to the low 8 kB 5815of DRAM (0x00000000 ... 0x00001FFF). 5816 5817So a typical memory configuration with 16 MB of DRAM could look like 5818this: 5819 5820 0x0000 0000 Exception Vector code 5821 : 5822 0x0000 1FFF 5823 0x0000 2000 Free for Application Use 5824 : 5825 : 5826 5827 : 5828 : 5829 0x00FB FF20 Monitor Stack (Growing downward) 5830 0x00FB FFAC Board Info Data and permanent copy of global data 5831 0x00FC 0000 Malloc Arena 5832 : 5833 0x00FD FFFF 5834 0x00FE 0000 RAM Copy of Monitor Code 5835 ... eventually: LCD or video framebuffer 5836 ... eventually: pRAM (Protected RAM - unchanged by reset) 5837 0x00FF FFFF [End of RAM] 5838 5839 5840System Initialization: 5841---------------------- 5842 5843In the reset configuration, U-Boot starts at the reset entry point 5844(on most PowerPC systems at address 0x00000100). Because of the reset 5845configuration for CS0# this is a mirror of the on board Flash memory. 5846To be able to re-map memory U-Boot then jumps to its link address. 5847To be able to implement the initialization code in C, a (small!) 5848initial stack is set up in the internal Dual Ported RAM (in case CPUs 5849which provide such a feature like MPC8xx or MPC8260), or in a locked 5850part of the data cache. After that, U-Boot initializes the CPU core, 5851the caches and the SIU. 5852 5853Next, all (potentially) available memory banks are mapped using a 5854preliminary mapping. For example, we put them on 512 MB boundaries 5855(multiples of 0x20000000: SDRAM on 0x00000000 and 0x20000000, Flash 5856on 0x40000000 and 0x60000000, SRAM on 0x80000000). Then UPM A is 5857programmed for SDRAM access. Using the temporary configuration, a 5858simple memory test is run that determines the size of the SDRAM 5859banks. 5860 5861When there is more than one SDRAM bank, and the banks are of 5862different size, the largest is mapped first. For equal size, the first 5863bank (CS2#) is mapped first. The first mapping is always for address 58640x00000000, with any additional banks following immediately to create 5865contiguous memory starting from 0. 5866 5867Then, the monitor installs itself at the upper end of the SDRAM area 5868and allocates memory for use by malloc() and for the global Board 5869Info data; also, the exception vector code is copied to the low RAM 5870pages, and the final stack is set up. 5871 5872Only after this relocation will you have a "normal" C environment; 5873until that you are restricted in several ways, mostly because you are 5874running from ROM, and because the code will have to be relocated to a 5875new address in RAM. 5876 5877 5878U-Boot Porting Guide: 5879---------------------- 5880 5881[Based on messages by Jerry Van Baren in the U-Boot-Users mailing 5882list, October 2002] 5883 5884 5885int main(int argc, char *argv[]) 5886{ 5887 sighandler_t no_more_time; 5888 5889 signal(SIGALRM, no_more_time); 5890 alarm(PROJECT_DEADLINE - toSec (3 * WEEK)); 5891 5892 if (available_money > available_manpower) { 5893 Pay consultant to port U-Boot; 5894 return 0; 5895 } 5896 5897 Download latest U-Boot source; 5898 5899 Subscribe to u-boot mailing list; 5900 5901 if (clueless) 5902 email("Hi, I am new to U-Boot, how do I get started?"); 5903 5904 while (learning) { 5905 Read the README file in the top level directory; 5906 Read http://www.denx.de/twiki/bin/view/DULG/Manual; 5907 Read applicable doc/*.README; 5908 Read the source, Luke; 5909 /* find . -name "*.[chS]" | xargs grep -i <keyword> */ 5910 } 5911 5912 if (available_money > toLocalCurrency ($2500)) 5913 Buy a BDI3000; 5914 else 5915 Add a lot of aggravation and time; 5916 5917 if (a similar board exists) { /* hopefully... */ 5918 cp -a board/<similar> board/<myboard> 5919 cp include/configs/<similar>.h include/configs/<myboard>.h 5920 } else { 5921 Create your own board support subdirectory; 5922 Create your own board include/configs/<myboard>.h file; 5923 } 5924 Edit new board/<myboard> files 5925 Edit new include/configs/<myboard>.h 5926 5927 while (!accepted) { 5928 while (!running) { 5929 do { 5930 Add / modify source code; 5931 } until (compiles); 5932 Debug; 5933 if (clueless) 5934 email("Hi, I am having problems..."); 5935 } 5936 Send patch file to the U-Boot email list; 5937 if (reasonable critiques) 5938 Incorporate improvements from email list code review; 5939 else 5940 Defend code as written; 5941 } 5942 5943 return 0; 5944} 5945 5946void no_more_time (int sig) 5947{ 5948 hire_a_guru(); 5949} 5950 5951 5952Coding Standards: 5953----------------- 5954 5955All contributions to U-Boot should conform to the Linux kernel 5956coding style; see the file "Documentation/CodingStyle" and the script 5957"scripts/Lindent" in your Linux kernel source directory. 5958 5959Source files originating from a different project (for example the 5960MTD subsystem) are generally exempt from these guidelines and are not 5961reformatted to ease subsequent migration to newer versions of those 5962sources. 5963 5964Please note that U-Boot is implemented in C (and to some small parts in 5965Assembler); no C++ is used, so please do not use C++ style comments (//) 5966in your code. 5967 5968Please also stick to the following formatting rules: 5969- remove any trailing white space 5970- use TAB characters for indentation and vertical alignment, not spaces 5971- make sure NOT to use DOS '\r\n' line feeds 5972- do not add more than 2 consecutive empty lines to source files 5973- do not add trailing empty lines to source files 5974 5975Submissions which do not conform to the standards may be returned 5976with a request to reformat the changes. 5977 5978 5979Submitting Patches: 5980------------------- 5981 5982Since the number of patches for U-Boot is growing, we need to 5983establish some rules. Submissions which do not conform to these rules 5984may be rejected, even when they contain important and valuable stuff. 5985 5986Please see http://www.denx.de/wiki/U-Boot/Patches for details. 5987 5988Patches shall be sent to the u-boot mailing list <u-boot@lists.denx.de>; 5989see http://lists.denx.de/mailman/listinfo/u-boot 5990 5991When you send a patch, please include the following information with 5992it: 5993 5994* For bug fixes: a description of the bug and how your patch fixes 5995 this bug. Please try to include a way of demonstrating that the 5996 patch actually fixes something. 5997 5998* For new features: a description of the feature and your 5999 implementation. 6000 6001* A CHANGELOG entry as plaintext (separate from the patch) 6002 6003* For major contributions, add a MAINTAINERS file with your 6004 information and associated file and directory references. 6005 6006* When you add support for a new board, don't forget to add a 6007 maintainer e-mail address to the boards.cfg file, too. 6008 6009* If your patch adds new configuration options, don't forget to 6010 document these in the README file. 6011 6012* The patch itself. If you are using git (which is *strongly* 6013 recommended) you can easily generate the patch using the 6014 "git format-patch". If you then use "git send-email" to send it to 6015 the U-Boot mailing list, you will avoid most of the common problems 6016 with some other mail clients. 6017 6018 If you cannot use git, use "diff -purN OLD NEW". If your version of 6019 diff does not support these options, then get the latest version of 6020 GNU diff. 6021 6022 The current directory when running this command shall be the parent 6023 directory of the U-Boot source tree (i. e. please make sure that 6024 your patch includes sufficient directory information for the 6025 affected files). 6026 6027 We prefer patches as plain text. MIME attachments are discouraged, 6028 and compressed attachments must not be used. 6029 6030* If one logical set of modifications affects or creates several 6031 files, all these changes shall be submitted in a SINGLE patch file. 6032 6033* Changesets that contain different, unrelated modifications shall be 6034 submitted as SEPARATE patches, one patch per changeset. 6035 6036 6037Notes: 6038 6039* Before sending the patch, run the buildman script on your patched 6040 source tree and make sure that no errors or warnings are reported 6041 for any of the boards. 6042 6043* Keep your modifications to the necessary minimum: A patch 6044 containing several unrelated changes or arbitrary reformats will be 6045 returned with a request to re-formatting / split it. 6046 6047* If you modify existing code, make sure that your new code does not 6048 add to the memory footprint of the code ;-) Small is beautiful! 6049 When adding new features, these should compile conditionally only 6050 (using #ifdef), and the resulting code with the new feature 6051 disabled must not need more memory than the old code without your 6052 modification. 6053 6054* Remember that there is a size limit of 100 kB per message on the 6055 u-boot mailing list. Bigger patches will be moderated. If they are 6056 reasonable and not too big, they will be acknowledged. But patches 6057 bigger than the size limit should be avoided. 6058