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 defining 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_BMP * BMP support 827 CONFIG_CMD_BSP * Board specific commands 828 CONFIG_CMD_BOOTD bootd 829 CONFIG_CMD_BOOTI * ARM64 Linux kernel Image support 830 CONFIG_CMD_CACHE * icache, dcache 831 CONFIG_CMD_CLK * clock command support 832 CONFIG_CMD_CONSOLE coninfo 833 CONFIG_CMD_CRC32 * crc32 834 CONFIG_CMD_DATE * support for RTC, date/time... 835 CONFIG_CMD_DHCP * DHCP support 836 CONFIG_CMD_DIAG * Diagnostics 837 CONFIG_CMD_DS4510 * ds4510 I2C gpio commands 838 CONFIG_CMD_DS4510_INFO * ds4510 I2C info command 839 CONFIG_CMD_DS4510_MEM * ds4510 I2C eeprom/sram commansd 840 CONFIG_CMD_DS4510_RST * ds4510 I2C rst command 841 CONFIG_CMD_DTT * Digital Therm and Thermostat 842 CONFIG_CMD_ECHO echo arguments 843 CONFIG_CMD_EDITENV edit env variable 844 CONFIG_CMD_EEPROM * EEPROM read/write support 845 CONFIG_CMD_EEPROM_LAYOUT* EEPROM layout aware commands 846 CONFIG_CMD_ELF * bootelf, bootvx 847 CONFIG_CMD_ENV_CALLBACK * display details about env callbacks 848 CONFIG_CMD_ENV_FLAGS * display details about env flags 849 CONFIG_CMD_ENV_EXISTS * check existence of env variable 850 CONFIG_CMD_EXPORTENV * export the environment 851 CONFIG_CMD_EXT2 * ext2 command support 852 CONFIG_CMD_EXT4 * ext4 command support 853 CONFIG_CMD_FS_GENERIC * filesystem commands (e.g. load, ls) 854 that work for multiple fs types 855 CONFIG_CMD_FS_UUID * Look up a filesystem UUID 856 CONFIG_CMD_SAVEENV saveenv 857 CONFIG_CMD_FDC * Floppy Disk Support 858 CONFIG_CMD_FAT * FAT command support 859 CONFIG_CMD_FLASH flinfo, erase, protect 860 CONFIG_CMD_FPGA FPGA device initialization support 861 CONFIG_CMD_FUSE * Device fuse support 862 CONFIG_CMD_GETTIME * Get time since boot 863 CONFIG_CMD_GO * the 'go' command (exec code) 864 CONFIG_CMD_GREPENV * search environment 865 CONFIG_CMD_HASH * calculate hash / digest 866 CONFIG_CMD_I2C * I2C serial bus support 867 CONFIG_CMD_IDE * IDE harddisk support 868 CONFIG_CMD_IMI iminfo 869 CONFIG_CMD_IMLS List all images found in NOR flash 870 CONFIG_CMD_IMLS_NAND * List all images found in NAND flash 871 CONFIG_CMD_IMMAP * IMMR dump support 872 CONFIG_CMD_IOTRACE * I/O tracing for debugging 873 CONFIG_CMD_IMPORTENV * import an environment 874 CONFIG_CMD_INI * import data from an ini file into the env 875 CONFIG_CMD_IRQ * irqinfo 876 CONFIG_CMD_ITEST Integer/string test of 2 values 877 CONFIG_CMD_JFFS2 * JFFS2 Support 878 CONFIG_CMD_KGDB * kgdb 879 CONFIG_CMD_LDRINFO * ldrinfo (display Blackfin loader) 880 CONFIG_CMD_LINK_LOCAL * link-local IP address auto-configuration 881 (169.254.*.*) 882 CONFIG_CMD_LOADB loadb 883 CONFIG_CMD_LOADS loads 884 CONFIG_CMD_MD5SUM * print md5 message digest 885 (requires CONFIG_CMD_MEMORY and CONFIG_MD5) 886 CONFIG_CMD_MEMINFO * Display detailed memory information 887 CONFIG_CMD_MEMORY md, mm, nm, mw, cp, cmp, crc, base, 888 loop, loopw 889 CONFIG_CMD_MEMTEST * mtest 890 CONFIG_CMD_MISC Misc functions like sleep etc 891 CONFIG_CMD_MMC * MMC memory mapped support 892 CONFIG_CMD_MII * MII utility commands 893 CONFIG_CMD_MTDPARTS * MTD partition support 894 CONFIG_CMD_NAND * NAND support 895 CONFIG_CMD_NET bootp, tftpboot, rarpboot 896 CONFIG_CMD_NFS NFS support 897 CONFIG_CMD_PCA953X * PCA953x I2C gpio commands 898 CONFIG_CMD_PCA953X_INFO * PCA953x I2C gpio info command 899 CONFIG_CMD_PCI * pciinfo 900 CONFIG_CMD_PCMCIA * PCMCIA support 901 CONFIG_CMD_PING * send ICMP ECHO_REQUEST to network 902 host 903 CONFIG_CMD_PORTIO * Port I/O 904 CONFIG_CMD_READ * Read raw data from partition 905 CONFIG_CMD_REGINFO * Register dump 906 CONFIG_CMD_RUN run command in env variable 907 CONFIG_CMD_SANDBOX * sb command to access sandbox features 908 CONFIG_CMD_SAVES * save S record dump 909 CONFIG_SCSI * SCSI Support 910 CONFIG_CMD_SDRAM * print SDRAM configuration information 911 (requires CONFIG_CMD_I2C) 912 CONFIG_CMD_SETGETDCR Support for DCR Register access 913 (4xx only) 914 CONFIG_CMD_SF * Read/write/erase SPI NOR flash 915 CONFIG_CMD_SHA1SUM * print sha1 memory digest 916 (requires CONFIG_CMD_MEMORY) 917 CONFIG_CMD_SOFTSWITCH * Soft switch setting command for BF60x 918 CONFIG_CMD_SOURCE "source" command Support 919 CONFIG_CMD_SPI * SPI serial bus support 920 CONFIG_CMD_TFTPSRV * TFTP transfer in server mode 921 CONFIG_CMD_TFTPPUT * TFTP put command (upload) 922 CONFIG_CMD_TIME * run command and report execution time (ARM specific) 923 CONFIG_CMD_TIMER * access to the system tick timer 924 CONFIG_CMD_USB * USB support 925 CONFIG_CMD_CDP * Cisco Discover Protocol support 926 CONFIG_CMD_MFSL * Microblaze FSL support 927 CONFIG_CMD_XIMG Load part of Multi Image 928 CONFIG_CMD_UUID * Generate random UUID or GUID string 929 930 EXAMPLE: If you want all functions except of network 931 support you can write: 932 933 #include "config_cmd_all.h" 934 #undef CONFIG_CMD_NET 935 936 Other Commands: 937 fdt (flattened device tree) command: CONFIG_OF_LIBFDT 938 939 Note: Don't enable the "icache" and "dcache" commands 940 (configuration option CONFIG_CMD_CACHE) unless you know 941 what you (and your U-Boot users) are doing. Data 942 cache cannot be enabled on systems like the 8xx or 943 8260 (where accesses to the IMMR region must be 944 uncached), and it cannot be disabled on all other 945 systems where we (mis-) use the data cache to hold an 946 initial stack and some data. 947 948 949 XXX - this list needs to get updated! 950 951- Removal of commands 952 If no commands are needed to boot, you can disable 953 CONFIG_CMDLINE to remove them. In this case, the command line 954 will not be available, and when U-Boot wants to execute the 955 boot command (on start-up) it will call board_run_command() 956 instead. This can reduce image size significantly for very 957 simple boot procedures. 958 959- Regular expression support: 960 CONFIG_REGEX 961 If this variable is defined, U-Boot is linked against 962 the SLRE (Super Light Regular Expression) library, 963 which adds regex support to some commands, as for 964 example "env grep" and "setexpr". 965 966- Device tree: 967 CONFIG_OF_CONTROL 968 If this variable is defined, U-Boot will use a device tree 969 to configure its devices, instead of relying on statically 970 compiled #defines in the board file. This option is 971 experimental and only available on a few boards. The device 972 tree is available in the global data as gd->fdt_blob. 973 974 U-Boot needs to get its device tree from somewhere. This can 975 be done using one of the two options below: 976 977 CONFIG_OF_EMBED 978 If this variable is defined, U-Boot will embed a device tree 979 binary in its image. This device tree file should be in the 980 board directory and called <soc>-<board>.dts. The binary file 981 is then picked up in board_init_f() and made available through 982 the global data structure as gd->blob. 983 984 CONFIG_OF_SEPARATE 985 If this variable is defined, U-Boot will build a device tree 986 binary. It will be called u-boot.dtb. Architecture-specific 987 code will locate it at run-time. Generally this works by: 988 989 cat u-boot.bin u-boot.dtb >image.bin 990 991 and in fact, U-Boot does this for you, creating a file called 992 u-boot-dtb.bin which is useful in the common case. You can 993 still use the individual files if you need something more 994 exotic. 995 996- Watchdog: 997 CONFIG_WATCHDOG 998 If this variable is defined, it enables watchdog 999 support for the SoC. There must be support in the SoC 1000 specific code for a watchdog. For the 8xx and 8260 1001 CPUs, the SIU Watchdog feature is enabled in the SYPCR 1002 register. When supported for a specific SoC is 1003 available, then no further board specific code should 1004 be needed to use it. 1005 1006 CONFIG_HW_WATCHDOG 1007 When using a watchdog circuitry external to the used 1008 SoC, then define this variable and provide board 1009 specific code for the "hw_watchdog_reset" function. 1010 1011 CONFIG_AT91_HW_WDT_TIMEOUT 1012 specify the timeout in seconds. default 2 seconds. 1013 1014- U-Boot Version: 1015 CONFIG_VERSION_VARIABLE 1016 If this variable is defined, an environment variable 1017 named "ver" is created by U-Boot showing the U-Boot 1018 version as printed by the "version" command. 1019 Any change to this variable will be reverted at the 1020 next reset. 1021 1022- Real-Time Clock: 1023 1024 When CONFIG_CMD_DATE is selected, the type of the RTC 1025 has to be selected, too. Define exactly one of the 1026 following options: 1027 1028 CONFIG_RTC_MPC8xx - use internal RTC of MPC8xx 1029 CONFIG_RTC_PCF8563 - use Philips PCF8563 RTC 1030 CONFIG_RTC_MC13XXX - use MC13783 or MC13892 RTC 1031 CONFIG_RTC_MC146818 - use MC146818 RTC 1032 CONFIG_RTC_DS1307 - use Maxim, Inc. DS1307 RTC 1033 CONFIG_RTC_DS1337 - use Maxim, Inc. DS1337 RTC 1034 CONFIG_RTC_DS1338 - use Maxim, Inc. DS1338 RTC 1035 CONFIG_RTC_DS1339 - use Maxim, Inc. DS1339 RTC 1036 CONFIG_RTC_DS164x - use Dallas DS164x RTC 1037 CONFIG_RTC_ISL1208 - use Intersil ISL1208 RTC 1038 CONFIG_RTC_MAX6900 - use Maxim, Inc. MAX6900 RTC 1039 CONFIG_SYS_RTC_DS1337_NOOSC - Turn off the OSC output for DS1337 1040 CONFIG_SYS_RV3029_TCR - enable trickle charger on 1041 RV3029 RTC. 1042 1043 Note that if the RTC uses I2C, then the I2C interface 1044 must also be configured. See I2C Support, below. 1045 1046- GPIO Support: 1047 CONFIG_PCA953X - use NXP's PCA953X series I2C GPIO 1048 1049 The CONFIG_SYS_I2C_PCA953X_WIDTH option specifies a list of 1050 chip-ngpio pairs that tell the PCA953X driver the number of 1051 pins supported by a particular chip. 1052 1053 Note that if the GPIO device uses I2C, then the I2C interface 1054 must also be configured. See I2C Support, below. 1055 1056- I/O tracing: 1057 When CONFIG_IO_TRACE is selected, U-Boot intercepts all I/O 1058 accesses and can checksum them or write a list of them out 1059 to memory. See the 'iotrace' command for details. This is 1060 useful for testing device drivers since it can confirm that 1061 the driver behaves the same way before and after a code 1062 change. Currently this is supported on sandbox and arm. To 1063 add support for your architecture, add '#include <iotrace.h>' 1064 to the bottom of arch/<arch>/include/asm/io.h and test. 1065 1066 Example output from the 'iotrace stats' command is below. 1067 Note that if the trace buffer is exhausted, the checksum will 1068 still continue to operate. 1069 1070 iotrace is enabled 1071 Start: 10000000 (buffer start address) 1072 Size: 00010000 (buffer size) 1073 Offset: 00000120 (current buffer offset) 1074 Output: 10000120 (start + offset) 1075 Count: 00000018 (number of trace records) 1076 CRC32: 9526fb66 (CRC32 of all trace records) 1077 1078- Timestamp Support: 1079 1080 When CONFIG_TIMESTAMP is selected, the timestamp 1081 (date and time) of an image is printed by image 1082 commands like bootm or iminfo. This option is 1083 automatically enabled when you select CONFIG_CMD_DATE . 1084 1085- Partition Labels (disklabels) Supported: 1086 Zero or more of the following: 1087 CONFIG_MAC_PARTITION Apple's MacOS partition table. 1088 CONFIG_DOS_PARTITION MS Dos partition table, traditional on the 1089 Intel architecture, USB sticks, etc. 1090 CONFIG_ISO_PARTITION ISO partition table, used on CDROM etc. 1091 CONFIG_EFI_PARTITION GPT partition table, common when EFI is the 1092 bootloader. Note 2TB partition limit; see 1093 disk/part_efi.c 1094 CONFIG_MTD_PARTITIONS Memory Technology Device partition table. 1095 1096 If IDE or SCSI support is enabled (CONFIG_CMD_IDE or 1097 CONFIG_SCSI) you must configure support for at 1098 least one non-MTD partition type as well. 1099 1100- IDE Reset method: 1101 CONFIG_IDE_RESET_ROUTINE - this is defined in several 1102 board configurations files but used nowhere! 1103 1104 CONFIG_IDE_RESET - is this is defined, IDE Reset will 1105 be performed by calling the function 1106 ide_set_reset(int reset) 1107 which has to be defined in a board specific file 1108 1109- ATAPI Support: 1110 CONFIG_ATAPI 1111 1112 Set this to enable ATAPI support. 1113 1114- LBA48 Support 1115 CONFIG_LBA48 1116 1117 Set this to enable support for disks larger than 137GB 1118 Also look at CONFIG_SYS_64BIT_LBA. 1119 Whithout these , LBA48 support uses 32bit variables and will 'only' 1120 support disks up to 2.1TB. 1121 1122 CONFIG_SYS_64BIT_LBA: 1123 When enabled, makes the IDE subsystem use 64bit sector addresses. 1124 Default is 32bit. 1125 1126- SCSI Support: 1127 At the moment only there is only support for the 1128 SYM53C8XX SCSI controller; define 1129 CONFIG_SCSI_SYM53C8XX to enable it. 1130 1131 CONFIG_SYS_SCSI_MAX_LUN [8], CONFIG_SYS_SCSI_MAX_SCSI_ID [7] and 1132 CONFIG_SYS_SCSI_MAX_DEVICE [CONFIG_SYS_SCSI_MAX_SCSI_ID * 1133 CONFIG_SYS_SCSI_MAX_LUN] can be adjusted to define the 1134 maximum numbers of LUNs, SCSI ID's and target 1135 devices. 1136 CONFIG_SYS_SCSI_SYM53C8XX_CCF to fix clock timing (80Mhz) 1137 1138 The environment variable 'scsidevs' is set to the number of 1139 SCSI devices found during the last scan. 1140 1141- NETWORK Support (PCI): 1142 CONFIG_E1000 1143 Support for Intel 8254x/8257x gigabit chips. 1144 1145 CONFIG_E1000_SPI 1146 Utility code for direct access to the SPI bus on Intel 8257x. 1147 This does not do anything useful unless you set at least one 1148 of CONFIG_CMD_E1000 or CONFIG_E1000_SPI_GENERIC. 1149 1150 CONFIG_E1000_SPI_GENERIC 1151 Allow generic access to the SPI bus on the Intel 8257x, for 1152 example with the "sspi" command. 1153 1154 CONFIG_CMD_E1000 1155 Management command for E1000 devices. When used on devices 1156 with SPI support you can reprogram the EEPROM from U-Boot. 1157 1158 CONFIG_EEPRO100 1159 Support for Intel 82557/82559/82559ER chips. 1160 Optional CONFIG_EEPRO100_SROM_WRITE enables EEPROM 1161 write routine for first time initialisation. 1162 1163 CONFIG_TULIP 1164 Support for Digital 2114x chips. 1165 Optional CONFIG_TULIP_SELECT_MEDIA for board specific 1166 modem chip initialisation (KS8761/QS6611). 1167 1168 CONFIG_NATSEMI 1169 Support for National dp83815 chips. 1170 1171 CONFIG_NS8382X 1172 Support for National dp8382[01] gigabit chips. 1173 1174- NETWORK Support (other): 1175 1176 CONFIG_DRIVER_AT91EMAC 1177 Support for AT91RM9200 EMAC. 1178 1179 CONFIG_RMII 1180 Define this to use reduced MII inteface 1181 1182 CONFIG_DRIVER_AT91EMAC_QUIET 1183 If this defined, the driver is quiet. 1184 The driver doen't show link status messages. 1185 1186 CONFIG_CALXEDA_XGMAC 1187 Support for the Calxeda XGMAC device 1188 1189 CONFIG_LAN91C96 1190 Support for SMSC's LAN91C96 chips. 1191 1192 CONFIG_LAN91C96_USE_32_BIT 1193 Define this to enable 32 bit addressing 1194 1195 CONFIG_SMC91111 1196 Support for SMSC's LAN91C111 chip 1197 1198 CONFIG_SMC91111_BASE 1199 Define this to hold the physical address 1200 of the device (I/O space) 1201 1202 CONFIG_SMC_USE_32_BIT 1203 Define this if data bus is 32 bits 1204 1205 CONFIG_SMC_USE_IOFUNCS 1206 Define this to use i/o functions instead of macros 1207 (some hardware wont work with macros) 1208 1209 CONFIG_DRIVER_TI_EMAC 1210 Support for davinci emac 1211 1212 CONFIG_SYS_DAVINCI_EMAC_PHY_COUNT 1213 Define this if you have more then 3 PHYs. 1214 1215 CONFIG_FTGMAC100 1216 Support for Faraday's FTGMAC100 Gigabit SoC Ethernet 1217 1218 CONFIG_FTGMAC100_EGIGA 1219 Define this to use GE link update with gigabit PHY. 1220 Define this if FTGMAC100 is connected to gigabit PHY. 1221 If your system has 10/100 PHY only, it might not occur 1222 wrong behavior. Because PHY usually return timeout or 1223 useless data when polling gigabit status and gigabit 1224 control registers. This behavior won't affect the 1225 correctnessof 10/100 link speed update. 1226 1227 CONFIG_SMC911X 1228 Support for SMSC's LAN911x and LAN921x chips 1229 1230 CONFIG_SMC911X_BASE 1231 Define this to hold the physical address 1232 of the device (I/O space) 1233 1234 CONFIG_SMC911X_32_BIT 1235 Define this if data bus is 32 bits 1236 1237 CONFIG_SMC911X_16_BIT 1238 Define this if data bus is 16 bits. If your processor 1239 automatically converts one 32 bit word to two 16 bit 1240 words you may also try CONFIG_SMC911X_32_BIT. 1241 1242 CONFIG_SH_ETHER 1243 Support for Renesas on-chip Ethernet controller 1244 1245 CONFIG_SH_ETHER_USE_PORT 1246 Define the number of ports to be used 1247 1248 CONFIG_SH_ETHER_PHY_ADDR 1249 Define the ETH PHY's address 1250 1251 CONFIG_SH_ETHER_CACHE_WRITEBACK 1252 If this option is set, the driver enables cache flush. 1253 1254- PWM Support: 1255 CONFIG_PWM_IMX 1256 Support for PWM module on the imx6. 1257 1258- TPM Support: 1259 CONFIG_TPM 1260 Support TPM devices. 1261 1262 CONFIG_TPM_TIS_INFINEON 1263 Support for Infineon i2c bus TPM devices. Only one device 1264 per system is supported at this time. 1265 1266 CONFIG_TPM_TIS_I2C_BURST_LIMITATION 1267 Define the burst count bytes upper limit 1268 1269 CONFIG_TPM_ST33ZP24 1270 Support for STMicroelectronics TPM devices. Requires DM_TPM support. 1271 1272 CONFIG_TPM_ST33ZP24_I2C 1273 Support for STMicroelectronics ST33ZP24 I2C devices. 1274 Requires TPM_ST33ZP24 and I2C. 1275 1276 CONFIG_TPM_ST33ZP24_SPI 1277 Support for STMicroelectronics ST33ZP24 SPI devices. 1278 Requires TPM_ST33ZP24 and SPI. 1279 1280 CONFIG_TPM_ATMEL_TWI 1281 Support for Atmel TWI TPM device. Requires I2C support. 1282 1283 CONFIG_TPM_TIS_LPC 1284 Support for generic parallel port TPM devices. Only one device 1285 per system is supported at this time. 1286 1287 CONFIG_TPM_TIS_BASE_ADDRESS 1288 Base address where the generic TPM device is mapped 1289 to. Contemporary x86 systems usually map it at 1290 0xfed40000. 1291 1292 CONFIG_CMD_TPM 1293 Add tpm monitor functions. 1294 Requires CONFIG_TPM. If CONFIG_TPM_AUTH_SESSIONS is set, also 1295 provides monitor access to authorized functions. 1296 1297 CONFIG_TPM 1298 Define this to enable the TPM support library which provides 1299 functional interfaces to some TPM commands. 1300 Requires support for a TPM device. 1301 1302 CONFIG_TPM_AUTH_SESSIONS 1303 Define this to enable authorized functions in the TPM library. 1304 Requires CONFIG_TPM and CONFIG_SHA1. 1305 1306- USB Support: 1307 At the moment only the UHCI host controller is 1308 supported (PIP405, MIP405, MPC5200); define 1309 CONFIG_USB_UHCI to enable it. 1310 define CONFIG_USB_KEYBOARD to enable the USB Keyboard 1311 and define CONFIG_USB_STORAGE to enable the USB 1312 storage devices. 1313 Note: 1314 Supported are USB Keyboards and USB Floppy drives 1315 (TEAC FD-05PUB). 1316 MPC5200 USB requires additional defines: 1317 CONFIG_USB_CLOCK 1318 for 528 MHz Clock: 0x0001bbbb 1319 CONFIG_PSC3_USB 1320 for USB on PSC3 1321 CONFIG_USB_CONFIG 1322 for differential drivers: 0x00001000 1323 for single ended drivers: 0x00005000 1324 for differential drivers on PSC3: 0x00000100 1325 for single ended drivers on PSC3: 0x00004100 1326 CONFIG_SYS_USB_EVENT_POLL 1327 May be defined to allow interrupt polling 1328 instead of using asynchronous interrupts 1329 1330 CONFIG_USB_EHCI_TXFIFO_THRESH enables setting of the 1331 txfilltuning field in the EHCI controller on reset. 1332 1333 CONFIG_USB_DWC2_REG_ADDR the physical CPU address of the DWC2 1334 HW module registers. 1335 1336- USB Device: 1337 Define the below if you wish to use the USB console. 1338 Once firmware is rebuilt from a serial console issue the 1339 command "setenv stdin usbtty; setenv stdout usbtty" and 1340 attach your USB cable. The Unix command "dmesg" should print 1341 it has found a new device. The environment variable usbtty 1342 can be set to gserial or cdc_acm to enable your device to 1343 appear to a USB host as a Linux gserial device or a 1344 Common Device Class Abstract Control Model serial device. 1345 If you select usbtty = gserial you should be able to enumerate 1346 a Linux host by 1347 # modprobe usbserial vendor=0xVendorID product=0xProductID 1348 else if using cdc_acm, simply setting the environment 1349 variable usbtty to be cdc_acm should suffice. The following 1350 might be defined in YourBoardName.h 1351 1352 CONFIG_USB_DEVICE 1353 Define this to build a UDC device 1354 1355 CONFIG_USB_TTY 1356 Define this to have a tty type of device available to 1357 talk to the UDC device 1358 1359 CONFIG_USBD_HS 1360 Define this to enable the high speed support for usb 1361 device and usbtty. If this feature is enabled, a routine 1362 int is_usbd_high_speed(void) 1363 also needs to be defined by the driver to dynamically poll 1364 whether the enumeration has succeded at high speed or full 1365 speed. 1366 1367 CONFIG_SYS_CONSOLE_IS_IN_ENV 1368 Define this if you want stdin, stdout &/or stderr to 1369 be set to usbtty. 1370 1371 mpc8xx: 1372 CONFIG_SYS_USB_EXTC_CLK 0xBLAH 1373 Derive USB clock from external clock "blah" 1374 - CONFIG_SYS_USB_EXTC_CLK 0x02 1375 1376 If you have a USB-IF assigned VendorID then you may wish to 1377 define your own vendor specific values either in BoardName.h 1378 or directly in usbd_vendor_info.h. If you don't define 1379 CONFIG_USBD_MANUFACTURER, CONFIG_USBD_PRODUCT_NAME, 1380 CONFIG_USBD_VENDORID and CONFIG_USBD_PRODUCTID, then U-Boot 1381 should pretend to be a Linux device to it's target host. 1382 1383 CONFIG_USBD_MANUFACTURER 1384 Define this string as the name of your company for 1385 - CONFIG_USBD_MANUFACTURER "my company" 1386 1387 CONFIG_USBD_PRODUCT_NAME 1388 Define this string as the name of your product 1389 - CONFIG_USBD_PRODUCT_NAME "acme usb device" 1390 1391 CONFIG_USBD_VENDORID 1392 Define this as your assigned Vendor ID from the USB 1393 Implementors Forum. This *must* be a genuine Vendor ID 1394 to avoid polluting the USB namespace. 1395 - CONFIG_USBD_VENDORID 0xFFFF 1396 1397 CONFIG_USBD_PRODUCTID 1398 Define this as the unique Product ID 1399 for your device 1400 - CONFIG_USBD_PRODUCTID 0xFFFF 1401 1402- ULPI Layer Support: 1403 The ULPI (UTMI Low Pin (count) Interface) PHYs are supported via 1404 the generic ULPI layer. The generic layer accesses the ULPI PHY 1405 via the platform viewport, so you need both the genric layer and 1406 the viewport enabled. Currently only Chipidea/ARC based 1407 viewport is supported. 1408 To enable the ULPI layer support, define CONFIG_USB_ULPI and 1409 CONFIG_USB_ULPI_VIEWPORT in your board configuration file. 1410 If your ULPI phy needs a different reference clock than the 1411 standard 24 MHz then you have to define CONFIG_ULPI_REF_CLK to 1412 the appropriate value in Hz. 1413 1414- MMC Support: 1415 The MMC controller on the Intel PXA is supported. To 1416 enable this define CONFIG_MMC. The MMC can be 1417 accessed from the boot prompt by mapping the device 1418 to physical memory similar to flash. Command line is 1419 enabled with CONFIG_CMD_MMC. The MMC driver also works with 1420 the FAT fs. This is enabled with CONFIG_CMD_FAT. 1421 1422 CONFIG_SH_MMCIF 1423 Support for Renesas on-chip MMCIF controller 1424 1425 CONFIG_SH_MMCIF_ADDR 1426 Define the base address of MMCIF registers 1427 1428 CONFIG_SH_MMCIF_CLK 1429 Define the clock frequency for MMCIF 1430 1431 CONFIG_SUPPORT_EMMC_BOOT 1432 Enable some additional features of the eMMC boot partitions. 1433 1434 CONFIG_SUPPORT_EMMC_RPMB 1435 Enable the commands for reading, writing and programming the 1436 key for the Replay Protection Memory Block partition in eMMC. 1437 1438- USB Device Firmware Update (DFU) class support: 1439 CONFIG_USB_FUNCTION_DFU 1440 This enables the USB portion of the DFU USB class 1441 1442 CONFIG_CMD_DFU 1443 This enables the command "dfu" which is used to have 1444 U-Boot create a DFU class device via USB. This command 1445 requires that the "dfu_alt_info" environment variable be 1446 set and define the alt settings to expose to the host. 1447 1448 CONFIG_DFU_MMC 1449 This enables support for exposing (e)MMC devices via DFU. 1450 1451 CONFIG_DFU_NAND 1452 This enables support for exposing NAND devices via DFU. 1453 1454 CONFIG_DFU_RAM 1455 This enables support for exposing RAM via DFU. 1456 Note: DFU spec refer to non-volatile memory usage, but 1457 allow usages beyond the scope of spec - here RAM usage, 1458 one that would help mostly the developer. 1459 1460 CONFIG_SYS_DFU_DATA_BUF_SIZE 1461 Dfu transfer uses a buffer before writing data to the 1462 raw storage device. Make the size (in bytes) of this buffer 1463 configurable. The size of this buffer is also configurable 1464 through the "dfu_bufsiz" environment variable. 1465 1466 CONFIG_SYS_DFU_MAX_FILE_SIZE 1467 When updating files rather than the raw storage device, 1468 we use a static buffer to copy the file into and then write 1469 the buffer once we've been given the whole file. Define 1470 this to the maximum filesize (in bytes) for the buffer. 1471 Default is 4 MiB if undefined. 1472 1473 DFU_DEFAULT_POLL_TIMEOUT 1474 Poll timeout [ms], is the timeout a device can send to the 1475 host. The host must wait for this timeout before sending 1476 a subsequent DFU_GET_STATUS request to the device. 1477 1478 DFU_MANIFEST_POLL_TIMEOUT 1479 Poll timeout [ms], which the device sends to the host when 1480 entering dfuMANIFEST state. Host waits this timeout, before 1481 sending again an USB request to the device. 1482 1483- USB Device Android Fastboot support: 1484 CONFIG_USB_FUNCTION_FASTBOOT 1485 This enables the USB part of the fastboot gadget 1486 1487 CONFIG_CMD_FASTBOOT 1488 This enables the command "fastboot" which enables the Android 1489 fastboot mode for the platform's USB device. Fastboot is a USB 1490 protocol for downloading images, flashing and device control 1491 used on Android devices. 1492 See doc/README.android-fastboot for more information. 1493 1494 CONFIG_ANDROID_BOOT_IMAGE 1495 This enables support for booting images which use the Android 1496 image format header. 1497 1498 CONFIG_FASTBOOT_BUF_ADDR 1499 The fastboot protocol requires a large memory buffer for 1500 downloads. Define this to the starting RAM address to use for 1501 downloaded images. 1502 1503 CONFIG_FASTBOOT_BUF_SIZE 1504 The fastboot protocol requires a large memory buffer for 1505 downloads. This buffer should be as large as possible for a 1506 platform. Define this to the size available RAM for fastboot. 1507 1508 CONFIG_FASTBOOT_FLASH 1509 The fastboot protocol includes a "flash" command for writing 1510 the downloaded image to a non-volatile storage device. Define 1511 this to enable the "fastboot flash" command. 1512 1513 CONFIG_FASTBOOT_FLASH_MMC_DEV 1514 The fastboot "flash" command requires additional information 1515 regarding the non-volatile storage device. Define this to 1516 the eMMC device that fastboot should use to store the image. 1517 1518 CONFIG_FASTBOOT_GPT_NAME 1519 The fastboot "flash" command supports writing the downloaded 1520 image to the Protective MBR and the Primary GUID Partition 1521 Table. (Additionally, this downloaded image is post-processed 1522 to generate and write the Backup GUID Partition Table.) 1523 This occurs when the specified "partition name" on the 1524 "fastboot flash" command line matches this value. 1525 The default is "gpt" if undefined. 1526 1527 CONFIG_FASTBOOT_MBR_NAME 1528 The fastboot "flash" command supports writing the downloaded 1529 image to DOS MBR. 1530 This occurs when the "partition name" specified on the 1531 "fastboot flash" command line matches this value. 1532 If not defined the default value "mbr" is used. 1533 1534- Journaling Flash filesystem support: 1535 CONFIG_JFFS2_NAND 1536 Define these for a default partition on a NAND device 1537 1538 CONFIG_SYS_JFFS2_FIRST_SECTOR, 1539 CONFIG_SYS_JFFS2_FIRST_BANK, CONFIG_SYS_JFFS2_NUM_BANKS 1540 Define these for a default partition on a NOR device 1541 1542- FAT(File Allocation Table) filesystem write function support: 1543 CONFIG_FAT_WRITE 1544 1545 Define this to enable support for saving memory data as a 1546 file in FAT formatted partition. 1547 1548 This will also enable the command "fatwrite" enabling the 1549 user to write files to FAT. 1550 1551- CBFS (Coreboot Filesystem) support: 1552 CONFIG_CMD_CBFS 1553 1554 Define this to enable support for reading from a Coreboot 1555 filesystem. Available commands are cbfsinit, cbfsinfo, cbfsls 1556 and cbfsload. 1557 1558- FAT(File Allocation Table) filesystem cluster size: 1559 CONFIG_FS_FAT_MAX_CLUSTSIZE 1560 1561 Define the max cluster size for fat operations else 1562 a default value of 65536 will be defined. 1563 1564- Keyboard Support: 1565 See Kconfig help for available keyboard drivers. 1566 1567 CONFIG_KEYBOARD 1568 1569 Define this to enable a custom keyboard support. 1570 This simply calls drv_keyboard_init() which must be 1571 defined in your board-specific files. This option is deprecated 1572 and is only used by novena. For new boards, use driver model 1573 instead. 1574 1575- Video support: 1576 CONFIG_FSL_DIU_FB 1577 Enable the Freescale DIU video driver. Reference boards for 1578 SOCs that have a DIU should define this macro to enable DIU 1579 support, and should also define these other macros: 1580 1581 CONFIG_SYS_DIU_ADDR 1582 CONFIG_VIDEO 1583 CONFIG_CMD_BMP 1584 CONFIG_CFB_CONSOLE 1585 CONFIG_VIDEO_SW_CURSOR 1586 CONFIG_VGA_AS_SINGLE_DEVICE 1587 CONFIG_VIDEO_LOGO 1588 CONFIG_VIDEO_BMP_LOGO 1589 1590 The DIU driver will look for the 'video-mode' environment 1591 variable, and if defined, enable the DIU as a console during 1592 boot. See the documentation file doc/README.video for a 1593 description of this variable. 1594 1595- LCD Support: CONFIG_LCD 1596 1597 Define this to enable LCD support (for output to LCD 1598 display); also select one of the supported displays 1599 by defining one of these: 1600 1601 CONFIG_ATMEL_LCD: 1602 1603 HITACHI TX09D70VM1CCA, 3.5", 240x320. 1604 1605 CONFIG_NEC_NL6448AC33: 1606 1607 NEC NL6448AC33-18. Active, color, single scan. 1608 1609 CONFIG_NEC_NL6448BC20 1610 1611 NEC NL6448BC20-08. 6.5", 640x480. 1612 Active, color, single scan. 1613 1614 CONFIG_NEC_NL6448BC33_54 1615 1616 NEC NL6448BC33-54. 10.4", 640x480. 1617 Active, color, single scan. 1618 1619 CONFIG_SHARP_16x9 1620 1621 Sharp 320x240. Active, color, single scan. 1622 It isn't 16x9, and I am not sure what it is. 1623 1624 CONFIG_SHARP_LQ64D341 1625 1626 Sharp LQ64D341 display, 640x480. 1627 Active, color, single scan. 1628 1629 CONFIG_HLD1045 1630 1631 HLD1045 display, 640x480. 1632 Active, color, single scan. 1633 1634 CONFIG_OPTREX_BW 1635 1636 Optrex CBL50840-2 NF-FW 99 22 M5 1637 or 1638 Hitachi LMG6912RPFC-00T 1639 or 1640 Hitachi SP14Q002 1641 1642 320x240. Black & white. 1643 1644 Normally display is black on white background; define 1645 CONFIG_SYS_WHITE_ON_BLACK to get it inverted. 1646 1647 CONFIG_LCD_ALIGNMENT 1648 1649 Normally the LCD is page-aligned (typically 4KB). If this is 1650 defined then the LCD will be aligned to this value instead. 1651 For ARM it is sometimes useful to use MMU_SECTION_SIZE 1652 here, since it is cheaper to change data cache settings on 1653 a per-section basis. 1654 1655 1656 CONFIG_LCD_ROTATION 1657 1658 Sometimes, for example if the display is mounted in portrait 1659 mode or even if it's mounted landscape but rotated by 180degree, 1660 we need to rotate our content of the display relative to the 1661 framebuffer, so that user can read the messages which are 1662 printed out. 1663 Once CONFIG_LCD_ROTATION is defined, the lcd_console will be 1664 initialized with a given rotation from "vl_rot" out of 1665 "vidinfo_t" which is provided by the board specific code. 1666 The value for vl_rot is coded as following (matching to 1667 fbcon=rotate:<n> linux-kernel commandline): 1668 0 = no rotation respectively 0 degree 1669 1 = 90 degree rotation 1670 2 = 180 degree rotation 1671 3 = 270 degree rotation 1672 1673 If CONFIG_LCD_ROTATION is not defined, the console will be 1674 initialized with 0degree rotation. 1675 1676 CONFIG_LCD_BMP_RLE8 1677 1678 Support drawing of RLE8-compressed bitmaps on the LCD. 1679 1680 CONFIG_I2C_EDID 1681 1682 Enables an 'i2c edid' command which can read EDID 1683 information over I2C from an attached LCD display. 1684 1685- Splash Screen Support: CONFIG_SPLASH_SCREEN 1686 1687 If this option is set, the environment is checked for 1688 a variable "splashimage". If found, the usual display 1689 of logo, copyright and system information on the LCD 1690 is suppressed and the BMP image at the address 1691 specified in "splashimage" is loaded instead. The 1692 console is redirected to the "nulldev", too. This 1693 allows for a "silent" boot where a splash screen is 1694 loaded very quickly after power-on. 1695 1696 CONFIG_SPLASHIMAGE_GUARD 1697 1698 If this option is set, then U-Boot will prevent the environment 1699 variable "splashimage" from being set to a problematic address 1700 (see doc/README.displaying-bmps). 1701 This option is useful for targets where, due to alignment 1702 restrictions, an improperly aligned BMP image will cause a data 1703 abort. If you think you will not have problems with unaligned 1704 accesses (for example because your toolchain prevents them) 1705 there is no need to set this option. 1706 1707 CONFIG_SPLASH_SCREEN_ALIGN 1708 1709 If this option is set the splash image can be freely positioned 1710 on the screen. Environment variable "splashpos" specifies the 1711 position as "x,y". If a positive number is given it is used as 1712 number of pixel from left/top. If a negative number is given it 1713 is used as number of pixel from right/bottom. You can also 1714 specify 'm' for centering the image. 1715 1716 Example: 1717 setenv splashpos m,m 1718 => image at center of screen 1719 1720 setenv splashpos 30,20 1721 => image at x = 30 and y = 20 1722 1723 setenv splashpos -10,m 1724 => vertically centered image 1725 at x = dspWidth - bmpWidth - 9 1726 1727- Gzip compressed BMP image support: CONFIG_VIDEO_BMP_GZIP 1728 1729 If this option is set, additionally to standard BMP 1730 images, gzipped BMP images can be displayed via the 1731 splashscreen support or the bmp command. 1732 1733- Run length encoded BMP image (RLE8) support: CONFIG_VIDEO_BMP_RLE8 1734 1735 If this option is set, 8-bit RLE compressed BMP images 1736 can be displayed via the splashscreen support or the 1737 bmp command. 1738 1739- Compression support: 1740 CONFIG_GZIP 1741 1742 Enabled by default to support gzip compressed images. 1743 1744 CONFIG_BZIP2 1745 1746 If this option is set, support for bzip2 compressed 1747 images is included. If not, only uncompressed and gzip 1748 compressed images are supported. 1749 1750 NOTE: the bzip2 algorithm requires a lot of RAM, so 1751 the malloc area (as defined by CONFIG_SYS_MALLOC_LEN) should 1752 be at least 4MB. 1753 1754 CONFIG_LZMA 1755 1756 If this option is set, support for lzma compressed 1757 images is included. 1758 1759 Note: The LZMA algorithm adds between 2 and 4KB of code and it 1760 requires an amount of dynamic memory that is given by the 1761 formula: 1762 1763 (1846 + 768 << (lc + lp)) * sizeof(uint16) 1764 1765 Where lc and lp stand for, respectively, Literal context bits 1766 and Literal pos bits. 1767 1768 This value is upper-bounded by 14MB in the worst case. Anyway, 1769 for a ~4MB large kernel image, we have lc=3 and lp=0 for a 1770 total amount of (1846 + 768 << (3 + 0)) * 2 = ~41KB... that is 1771 a very small buffer. 1772 1773 Use the lzmainfo tool to determinate the lc and lp values and 1774 then calculate the amount of needed dynamic memory (ensuring 1775 the appropriate CONFIG_SYS_MALLOC_LEN value). 1776 1777 CONFIG_LZO 1778 1779 If this option is set, support for LZO compressed images 1780 is included. 1781 1782- MII/PHY support: 1783 CONFIG_PHY_ADDR 1784 1785 The address of PHY on MII bus. 1786 1787 CONFIG_PHY_CLOCK_FREQ (ppc4xx) 1788 1789 The clock frequency of the MII bus 1790 1791 CONFIG_PHY_GIGE 1792 1793 If this option is set, support for speed/duplex 1794 detection of gigabit PHY is included. 1795 1796 CONFIG_PHY_RESET_DELAY 1797 1798 Some PHY like Intel LXT971A need extra delay after 1799 reset before any MII register access is possible. 1800 For such PHY, set this option to the usec delay 1801 required. (minimum 300usec for LXT971A) 1802 1803 CONFIG_PHY_CMD_DELAY (ppc4xx) 1804 1805 Some PHY like Intel LXT971A need extra delay after 1806 command issued before MII status register can be read 1807 1808- IP address: 1809 CONFIG_IPADDR 1810 1811 Define a default value for the IP address to use for 1812 the default Ethernet interface, in case this is not 1813 determined through e.g. bootp. 1814 (Environment variable "ipaddr") 1815 1816- Server IP address: 1817 CONFIG_SERVERIP 1818 1819 Defines a default value for the IP address of a TFTP 1820 server to contact when using the "tftboot" command. 1821 (Environment variable "serverip") 1822 1823 CONFIG_KEEP_SERVERADDR 1824 1825 Keeps the server's MAC address, in the env 'serveraddr' 1826 for passing to bootargs (like Linux's netconsole option) 1827 1828- Gateway IP address: 1829 CONFIG_GATEWAYIP 1830 1831 Defines a default value for the IP address of the 1832 default router where packets to other networks are 1833 sent to. 1834 (Environment variable "gatewayip") 1835 1836- Subnet mask: 1837 CONFIG_NETMASK 1838 1839 Defines a default value for the subnet mask (or 1840 routing prefix) which is used to determine if an IP 1841 address belongs to the local subnet or needs to be 1842 forwarded through a router. 1843 (Environment variable "netmask") 1844 1845- Multicast TFTP Mode: 1846 CONFIG_MCAST_TFTP 1847 1848 Defines whether you want to support multicast TFTP as per 1849 rfc-2090; for example to work with atftp. Lets lots of targets 1850 tftp down the same boot image concurrently. Note: the Ethernet 1851 driver in use must provide a function: mcast() to join/leave a 1852 multicast group. 1853 1854- BOOTP Recovery Mode: 1855 CONFIG_BOOTP_RANDOM_DELAY 1856 1857 If you have many targets in a network that try to 1858 boot using BOOTP, you may want to avoid that all 1859 systems send out BOOTP requests at precisely the same 1860 moment (which would happen for instance at recovery 1861 from a power failure, when all systems will try to 1862 boot, thus flooding the BOOTP server. Defining 1863 CONFIG_BOOTP_RANDOM_DELAY causes a random delay to be 1864 inserted before sending out BOOTP requests. The 1865 following delays are inserted then: 1866 1867 1st BOOTP request: delay 0 ... 1 sec 1868 2nd BOOTP request: delay 0 ... 2 sec 1869 3rd BOOTP request: delay 0 ... 4 sec 1870 4th and following 1871 BOOTP requests: delay 0 ... 8 sec 1872 1873 CONFIG_BOOTP_ID_CACHE_SIZE 1874 1875 BOOTP packets are uniquely identified using a 32-bit ID. The 1876 server will copy the ID from client requests to responses and 1877 U-Boot will use this to determine if it is the destination of 1878 an incoming response. Some servers will check that addresses 1879 aren't in use before handing them out (usually using an ARP 1880 ping) and therefore take up to a few hundred milliseconds to 1881 respond. Network congestion may also influence the time it 1882 takes for a response to make it back to the client. If that 1883 time is too long, U-Boot will retransmit requests. In order 1884 to allow earlier responses to still be accepted after these 1885 retransmissions, U-Boot's BOOTP client keeps a small cache of 1886 IDs. The CONFIG_BOOTP_ID_CACHE_SIZE controls the size of this 1887 cache. The default is to keep IDs for up to four outstanding 1888 requests. Increasing this will allow U-Boot to accept offers 1889 from a BOOTP client in networks with unusually high latency. 1890 1891- DHCP Advanced Options: 1892 You can fine tune the DHCP functionality by defining 1893 CONFIG_BOOTP_* symbols: 1894 1895 CONFIG_BOOTP_SUBNETMASK 1896 CONFIG_BOOTP_GATEWAY 1897 CONFIG_BOOTP_HOSTNAME 1898 CONFIG_BOOTP_NISDOMAIN 1899 CONFIG_BOOTP_BOOTPATH 1900 CONFIG_BOOTP_BOOTFILESIZE 1901 CONFIG_BOOTP_DNS 1902 CONFIG_BOOTP_DNS2 1903 CONFIG_BOOTP_SEND_HOSTNAME 1904 CONFIG_BOOTP_NTPSERVER 1905 CONFIG_BOOTP_TIMEOFFSET 1906 CONFIG_BOOTP_VENDOREX 1907 CONFIG_BOOTP_MAY_FAIL 1908 1909 CONFIG_BOOTP_SERVERIP - TFTP server will be the serverip 1910 environment variable, not the BOOTP server. 1911 1912 CONFIG_BOOTP_MAY_FAIL - If the DHCP server is not found 1913 after the configured retry count, the call will fail 1914 instead of starting over. This can be used to fail over 1915 to Link-local IP address configuration if the DHCP server 1916 is not available. 1917 1918 CONFIG_BOOTP_DNS2 - If a DHCP client requests the DNS 1919 serverip from a DHCP server, it is possible that more 1920 than one DNS serverip is offered to the client. 1921 If CONFIG_BOOTP_DNS2 is enabled, the secondary DNS 1922 serverip will be stored in the additional environment 1923 variable "dnsip2". The first DNS serverip is always 1924 stored in the variable "dnsip", when CONFIG_BOOTP_DNS 1925 is defined. 1926 1927 CONFIG_BOOTP_SEND_HOSTNAME - Some DHCP servers are capable 1928 to do a dynamic update of a DNS server. To do this, they 1929 need the hostname of the DHCP requester. 1930 If CONFIG_BOOTP_SEND_HOSTNAME is defined, the content 1931 of the "hostname" environment variable is passed as 1932 option 12 to the DHCP server. 1933 1934 CONFIG_BOOTP_DHCP_REQUEST_DELAY 1935 1936 A 32bit value in microseconds for a delay between 1937 receiving a "DHCP Offer" and sending the "DHCP Request". 1938 This fixes a problem with certain DHCP servers that don't 1939 respond 100% of the time to a "DHCP request". E.g. On an 1940 AT91RM9200 processor running at 180MHz, this delay needed 1941 to be *at least* 15,000 usec before a Windows Server 2003 1942 DHCP server would reply 100% of the time. I recommend at 1943 least 50,000 usec to be safe. The alternative is to hope 1944 that one of the retries will be successful but note that 1945 the DHCP timeout and retry process takes a longer than 1946 this delay. 1947 1948 - Link-local IP address negotiation: 1949 Negotiate with other link-local clients on the local network 1950 for an address that doesn't require explicit configuration. 1951 This is especially useful if a DHCP server cannot be guaranteed 1952 to exist in all environments that the device must operate. 1953 1954 See doc/README.link-local for more information. 1955 1956 - CDP Options: 1957 CONFIG_CDP_DEVICE_ID 1958 1959 The device id used in CDP trigger frames. 1960 1961 CONFIG_CDP_DEVICE_ID_PREFIX 1962 1963 A two character string which is prefixed to the MAC address 1964 of the device. 1965 1966 CONFIG_CDP_PORT_ID 1967 1968 A printf format string which contains the ascii name of 1969 the port. Normally is set to "eth%d" which sets 1970 eth0 for the first Ethernet, eth1 for the second etc. 1971 1972 CONFIG_CDP_CAPABILITIES 1973 1974 A 32bit integer which indicates the device capabilities; 1975 0x00000010 for a normal host which does not forwards. 1976 1977 CONFIG_CDP_VERSION 1978 1979 An ascii string containing the version of the software. 1980 1981 CONFIG_CDP_PLATFORM 1982 1983 An ascii string containing the name of the platform. 1984 1985 CONFIG_CDP_TRIGGER 1986 1987 A 32bit integer sent on the trigger. 1988 1989 CONFIG_CDP_POWER_CONSUMPTION 1990 1991 A 16bit integer containing the power consumption of the 1992 device in .1 of milliwatts. 1993 1994 CONFIG_CDP_APPLIANCE_VLAN_TYPE 1995 1996 A byte containing the id of the VLAN. 1997 1998- Status LED: CONFIG_LED_STATUS 1999 2000 Several configurations allow to display the current 2001 status using a LED. For instance, the LED will blink 2002 fast while running U-Boot code, stop blinking as 2003 soon as a reply to a BOOTP request was received, and 2004 start blinking slow once the Linux kernel is running 2005 (supported by a status LED driver in the Linux 2006 kernel). Defining CONFIG_LED_STATUS enables this 2007 feature in U-Boot. 2008 2009 Additional options: 2010 2011 CONFIG_LED_STATUS_GPIO 2012 The status LED can be connected to a GPIO pin. 2013 In such cases, the gpio_led driver can be used as a 2014 status LED backend implementation. Define CONFIG_LED_STATUS_GPIO 2015 to include the gpio_led driver in the U-Boot binary. 2016 2017 CONFIG_GPIO_LED_INVERTED_TABLE 2018 Some GPIO connected LEDs may have inverted polarity in which 2019 case the GPIO high value corresponds to LED off state and 2020 GPIO low value corresponds to LED on state. 2021 In such cases CONFIG_GPIO_LED_INVERTED_TABLE may be defined 2022 with a list of GPIO LEDs that have inverted polarity. 2023 2024- CAN Support: CONFIG_CAN_DRIVER 2025 2026 Defining CONFIG_CAN_DRIVER enables CAN driver support 2027 on those systems that support this (optional) 2028 feature, like the TQM8xxL modules. 2029 2030- I2C Support: CONFIG_SYS_I2C 2031 2032 This enable the NEW i2c subsystem, and will allow you to use 2033 i2c commands at the u-boot command line (as long as you set 2034 CONFIG_CMD_I2C in CONFIG_COMMANDS) and communicate with i2c 2035 based realtime clock chips or other i2c devices. See 2036 common/cmd_i2c.c for a description of the command line 2037 interface. 2038 2039 ported i2c driver to the new framework: 2040 - drivers/i2c/soft_i2c.c: 2041 - activate first bus with CONFIG_SYS_I2C_SOFT define 2042 CONFIG_SYS_I2C_SOFT_SPEED and CONFIG_SYS_I2C_SOFT_SLAVE 2043 for defining speed and slave address 2044 - activate second bus with I2C_SOFT_DECLARATIONS2 define 2045 CONFIG_SYS_I2C_SOFT_SPEED_2 and CONFIG_SYS_I2C_SOFT_SLAVE_2 2046 for defining speed and slave address 2047 - activate third bus with I2C_SOFT_DECLARATIONS3 define 2048 CONFIG_SYS_I2C_SOFT_SPEED_3 and CONFIG_SYS_I2C_SOFT_SLAVE_3 2049 for defining speed and slave address 2050 - activate fourth bus with I2C_SOFT_DECLARATIONS4 define 2051 CONFIG_SYS_I2C_SOFT_SPEED_4 and CONFIG_SYS_I2C_SOFT_SLAVE_4 2052 for defining speed and slave address 2053 2054 - drivers/i2c/fsl_i2c.c: 2055 - activate i2c driver with CONFIG_SYS_I2C_FSL 2056 define CONFIG_SYS_FSL_I2C_OFFSET for setting the register 2057 offset CONFIG_SYS_FSL_I2C_SPEED for the i2c speed and 2058 CONFIG_SYS_FSL_I2C_SLAVE for the slave addr of the first 2059 bus. 2060 - If your board supports a second fsl i2c bus, define 2061 CONFIG_SYS_FSL_I2C2_OFFSET for the register offset 2062 CONFIG_SYS_FSL_I2C2_SPEED for the speed and 2063 CONFIG_SYS_FSL_I2C2_SLAVE for the slave address of the 2064 second bus. 2065 2066 - drivers/i2c/tegra_i2c.c: 2067 - activate this driver with CONFIG_SYS_I2C_TEGRA 2068 - This driver adds 4 i2c buses with a fix speed from 2069 100000 and the slave addr 0! 2070 2071 - drivers/i2c/ppc4xx_i2c.c 2072 - activate this driver with CONFIG_SYS_I2C_PPC4XX 2073 - CONFIG_SYS_I2C_PPC4XX_CH0 activate hardware channel 0 2074 - CONFIG_SYS_I2C_PPC4XX_CH1 activate hardware channel 1 2075 2076 - drivers/i2c/i2c_mxc.c 2077 - activate this driver with CONFIG_SYS_I2C_MXC 2078 - enable bus 1 with CONFIG_SYS_I2C_MXC_I2C1 2079 - enable bus 2 with CONFIG_SYS_I2C_MXC_I2C2 2080 - enable bus 3 with CONFIG_SYS_I2C_MXC_I2C3 2081 - enable bus 4 with CONFIG_SYS_I2C_MXC_I2C4 2082 - define speed for bus 1 with CONFIG_SYS_MXC_I2C1_SPEED 2083 - define slave for bus 1 with CONFIG_SYS_MXC_I2C1_SLAVE 2084 - define speed for bus 2 with CONFIG_SYS_MXC_I2C2_SPEED 2085 - define slave for bus 2 with CONFIG_SYS_MXC_I2C2_SLAVE 2086 - define speed for bus 3 with CONFIG_SYS_MXC_I2C3_SPEED 2087 - define slave for bus 3 with CONFIG_SYS_MXC_I2C3_SLAVE 2088 - define speed for bus 4 with CONFIG_SYS_MXC_I2C4_SPEED 2089 - define slave for bus 4 with CONFIG_SYS_MXC_I2C4_SLAVE 2090 If those defines are not set, default value is 100000 2091 for speed, and 0 for slave. 2092 2093 - drivers/i2c/rcar_i2c.c: 2094 - activate this driver with CONFIG_SYS_I2C_RCAR 2095 - This driver adds 4 i2c buses 2096 2097 - CONFIG_SYS_RCAR_I2C0_BASE for setting the register channel 0 2098 - CONFIG_SYS_RCAR_I2C0_SPEED for for the speed channel 0 2099 - CONFIG_SYS_RCAR_I2C1_BASE for setting the register channel 1 2100 - CONFIG_SYS_RCAR_I2C1_SPEED for for the speed channel 1 2101 - CONFIG_SYS_RCAR_I2C2_BASE for setting the register channel 2 2102 - CONFIG_SYS_RCAR_I2C2_SPEED for for the speed channel 2 2103 - CONFIG_SYS_RCAR_I2C3_BASE for setting the register channel 3 2104 - CONFIG_SYS_RCAR_I2C3_SPEED for for the speed channel 3 2105 - CONFIF_SYS_RCAR_I2C_NUM_CONTROLLERS for number of i2c buses 2106 2107 - drivers/i2c/sh_i2c.c: 2108 - activate this driver with CONFIG_SYS_I2C_SH 2109 - This driver adds from 2 to 5 i2c buses 2110 2111 - CONFIG_SYS_I2C_SH_BASE0 for setting the register channel 0 2112 - CONFIG_SYS_I2C_SH_SPEED0 for for the speed channel 0 2113 - CONFIG_SYS_I2C_SH_BASE1 for setting the register channel 1 2114 - CONFIG_SYS_I2C_SH_SPEED1 for for the speed channel 1 2115 - CONFIG_SYS_I2C_SH_BASE2 for setting the register channel 2 2116 - CONFIG_SYS_I2C_SH_SPEED2 for for the speed channel 2 2117 - CONFIG_SYS_I2C_SH_BASE3 for setting the register channel 3 2118 - CONFIG_SYS_I2C_SH_SPEED3 for for the speed channel 3 2119 - CONFIG_SYS_I2C_SH_BASE4 for setting the register channel 4 2120 - CONFIG_SYS_I2C_SH_SPEED4 for for the speed channel 4 2121 - CONFIG_SYS_I2C_SH_NUM_CONTROLLERS for number of i2c buses 2122 2123 - drivers/i2c/omap24xx_i2c.c 2124 - activate this driver with CONFIG_SYS_I2C_OMAP24XX 2125 - CONFIG_SYS_OMAP24_I2C_SPEED speed channel 0 2126 - CONFIG_SYS_OMAP24_I2C_SLAVE slave addr channel 0 2127 - CONFIG_SYS_OMAP24_I2C_SPEED1 speed channel 1 2128 - CONFIG_SYS_OMAP24_I2C_SLAVE1 slave addr channel 1 2129 - CONFIG_SYS_OMAP24_I2C_SPEED2 speed channel 2 2130 - CONFIG_SYS_OMAP24_I2C_SLAVE2 slave addr channel 2 2131 - CONFIG_SYS_OMAP24_I2C_SPEED3 speed channel 3 2132 - CONFIG_SYS_OMAP24_I2C_SLAVE3 slave addr channel 3 2133 - CONFIG_SYS_OMAP24_I2C_SPEED4 speed channel 4 2134 - CONFIG_SYS_OMAP24_I2C_SLAVE4 slave addr channel 4 2135 2136 - drivers/i2c/zynq_i2c.c 2137 - activate this driver with CONFIG_SYS_I2C_ZYNQ 2138 - set CONFIG_SYS_I2C_ZYNQ_SPEED for speed setting 2139 - set CONFIG_SYS_I2C_ZYNQ_SLAVE for slave addr 2140 2141 - drivers/i2c/s3c24x0_i2c.c: 2142 - activate this driver with CONFIG_SYS_I2C_S3C24X0 2143 - This driver adds i2c buses (11 for Exynos5250, Exynos5420 2144 9 i2c buses for Exynos4 and 1 for S3C24X0 SoCs from Samsung) 2145 with a fix speed from 100000 and the slave addr 0! 2146 2147 - drivers/i2c/ihs_i2c.c 2148 - activate this driver with CONFIG_SYS_I2C_IHS 2149 - CONFIG_SYS_I2C_IHS_CH0 activate hardware channel 0 2150 - CONFIG_SYS_I2C_IHS_SPEED_0 speed channel 0 2151 - CONFIG_SYS_I2C_IHS_SLAVE_0 slave addr channel 0 2152 - CONFIG_SYS_I2C_IHS_CH1 activate hardware channel 1 2153 - CONFIG_SYS_I2C_IHS_SPEED_1 speed channel 1 2154 - CONFIG_SYS_I2C_IHS_SLAVE_1 slave addr channel 1 2155 - CONFIG_SYS_I2C_IHS_CH2 activate hardware channel 2 2156 - CONFIG_SYS_I2C_IHS_SPEED_2 speed channel 2 2157 - CONFIG_SYS_I2C_IHS_SLAVE_2 slave addr channel 2 2158 - CONFIG_SYS_I2C_IHS_CH3 activate hardware channel 3 2159 - CONFIG_SYS_I2C_IHS_SPEED_3 speed channel 3 2160 - CONFIG_SYS_I2C_IHS_SLAVE_3 slave addr channel 3 2161 - activate dual channel with CONFIG_SYS_I2C_IHS_DUAL 2162 - CONFIG_SYS_I2C_IHS_SPEED_0_1 speed channel 0_1 2163 - CONFIG_SYS_I2C_IHS_SLAVE_0_1 slave addr channel 0_1 2164 - CONFIG_SYS_I2C_IHS_SPEED_1_1 speed channel 1_1 2165 - CONFIG_SYS_I2C_IHS_SLAVE_1_1 slave addr channel 1_1 2166 - CONFIG_SYS_I2C_IHS_SPEED_2_1 speed channel 2_1 2167 - CONFIG_SYS_I2C_IHS_SLAVE_2_1 slave addr channel 2_1 2168 - CONFIG_SYS_I2C_IHS_SPEED_3_1 speed channel 3_1 2169 - CONFIG_SYS_I2C_IHS_SLAVE_3_1 slave addr channel 3_1 2170 2171 additional defines: 2172 2173 CONFIG_SYS_NUM_I2C_BUSES 2174 Hold the number of i2c buses you want to use. 2175 2176 CONFIG_SYS_I2C_DIRECT_BUS 2177 define this, if you don't use i2c muxes on your hardware. 2178 if CONFIG_SYS_I2C_MAX_HOPS is not defined or == 0 you can 2179 omit this define. 2180 2181 CONFIG_SYS_I2C_MAX_HOPS 2182 define how many muxes are maximal consecutively connected 2183 on one i2c bus. If you not use i2c muxes, omit this 2184 define. 2185 2186 CONFIG_SYS_I2C_BUSES 2187 hold a list of buses you want to use, only used if 2188 CONFIG_SYS_I2C_DIRECT_BUS is not defined, for example 2189 a board with CONFIG_SYS_I2C_MAX_HOPS = 1 and 2190 CONFIG_SYS_NUM_I2C_BUSES = 9: 2191 2192 CONFIG_SYS_I2C_BUSES {{0, {I2C_NULL_HOP}}, \ 2193 {0, {{I2C_MUX_PCA9547, 0x70, 1}}}, \ 2194 {0, {{I2C_MUX_PCA9547, 0x70, 2}}}, \ 2195 {0, {{I2C_MUX_PCA9547, 0x70, 3}}}, \ 2196 {0, {{I2C_MUX_PCA9547, 0x70, 4}}}, \ 2197 {0, {{I2C_MUX_PCA9547, 0x70, 5}}}, \ 2198 {1, {I2C_NULL_HOP}}, \ 2199 {1, {{I2C_MUX_PCA9544, 0x72, 1}}}, \ 2200 {1, {{I2C_MUX_PCA9544, 0x72, 2}}}, \ 2201 } 2202 2203 which defines 2204 bus 0 on adapter 0 without a mux 2205 bus 1 on adapter 0 with a PCA9547 on address 0x70 port 1 2206 bus 2 on adapter 0 with a PCA9547 on address 0x70 port 2 2207 bus 3 on adapter 0 with a PCA9547 on address 0x70 port 3 2208 bus 4 on adapter 0 with a PCA9547 on address 0x70 port 4 2209 bus 5 on adapter 0 with a PCA9547 on address 0x70 port 5 2210 bus 6 on adapter 1 without a mux 2211 bus 7 on adapter 1 with a PCA9544 on address 0x72 port 1 2212 bus 8 on adapter 1 with a PCA9544 on address 0x72 port 2 2213 2214 If you do not have i2c muxes on your board, omit this define. 2215 2216- Legacy I2C Support: CONFIG_HARD_I2C 2217 2218 NOTE: It is intended to move drivers to CONFIG_SYS_I2C which 2219 provides the following compelling advantages: 2220 2221 - more than one i2c adapter is usable 2222 - approved multibus support 2223 - better i2c mux support 2224 2225 ** Please consider updating your I2C driver now. ** 2226 2227 These enable legacy I2C serial bus commands. Defining 2228 CONFIG_HARD_I2C will include the appropriate I2C driver 2229 for the selected CPU. 2230 2231 This will allow you to use i2c commands at the u-boot 2232 command line (as long as you set CONFIG_CMD_I2C in 2233 CONFIG_COMMANDS) and communicate with i2c based realtime 2234 clock chips. See common/cmd_i2c.c for a description of the 2235 command line interface. 2236 2237 CONFIG_HARD_I2C selects a hardware I2C controller. 2238 2239 There are several other quantities that must also be 2240 defined when you define CONFIG_HARD_I2C. 2241 2242 In both cases you will need to define CONFIG_SYS_I2C_SPEED 2243 to be the frequency (in Hz) at which you wish your i2c bus 2244 to run and CONFIG_SYS_I2C_SLAVE to be the address of this node (ie 2245 the CPU's i2c node address). 2246 2247 Now, the u-boot i2c code for the mpc8xx 2248 (arch/powerpc/cpu/mpc8xx/i2c.c) sets the CPU up as a master node 2249 and so its address should therefore be cleared to 0 (See, 2250 eg, MPC823e User's Manual p.16-473). So, set 2251 CONFIG_SYS_I2C_SLAVE to 0. 2252 2253 CONFIG_SYS_I2C_INIT_MPC5XXX 2254 2255 When a board is reset during an i2c bus transfer 2256 chips might think that the current transfer is still 2257 in progress. Reset the slave devices by sending start 2258 commands until the slave device responds. 2259 2260 That's all that's required for CONFIG_HARD_I2C. 2261 2262 If you use the software i2c interface (CONFIG_SYS_I2C_SOFT) 2263 then the following macros need to be defined (examples are 2264 from include/configs/lwmon.h): 2265 2266 I2C_INIT 2267 2268 (Optional). Any commands necessary to enable the I2C 2269 controller or configure ports. 2270 2271 eg: #define I2C_INIT (immr->im_cpm.cp_pbdir |= PB_SCL) 2272 2273 I2C_PORT 2274 2275 (Only for MPC8260 CPU). The I/O port to use (the code 2276 assumes both bits are on the same port). Valid values 2277 are 0..3 for ports A..D. 2278 2279 I2C_ACTIVE 2280 2281 The code necessary to make the I2C data line active 2282 (driven). If the data line is open collector, this 2283 define can be null. 2284 2285 eg: #define I2C_ACTIVE (immr->im_cpm.cp_pbdir |= PB_SDA) 2286 2287 I2C_TRISTATE 2288 2289 The code necessary to make the I2C data line tri-stated 2290 (inactive). If the data line is open collector, this 2291 define can be null. 2292 2293 eg: #define I2C_TRISTATE (immr->im_cpm.cp_pbdir &= ~PB_SDA) 2294 2295 I2C_READ 2296 2297 Code that returns true if the I2C data line is high, 2298 false if it is low. 2299 2300 eg: #define I2C_READ ((immr->im_cpm.cp_pbdat & PB_SDA) != 0) 2301 2302 I2C_SDA(bit) 2303 2304 If <bit> is true, sets the I2C data line high. If it 2305 is false, it clears it (low). 2306 2307 eg: #define I2C_SDA(bit) \ 2308 if(bit) immr->im_cpm.cp_pbdat |= PB_SDA; \ 2309 else immr->im_cpm.cp_pbdat &= ~PB_SDA 2310 2311 I2C_SCL(bit) 2312 2313 If <bit> is true, sets the I2C clock line high. If it 2314 is false, it clears it (low). 2315 2316 eg: #define I2C_SCL(bit) \ 2317 if(bit) immr->im_cpm.cp_pbdat |= PB_SCL; \ 2318 else immr->im_cpm.cp_pbdat &= ~PB_SCL 2319 2320 I2C_DELAY 2321 2322 This delay is invoked four times per clock cycle so this 2323 controls the rate of data transfer. The data rate thus 2324 is 1 / (I2C_DELAY * 4). Often defined to be something 2325 like: 2326 2327 #define I2C_DELAY udelay(2) 2328 2329 CONFIG_SOFT_I2C_GPIO_SCL / CONFIG_SOFT_I2C_GPIO_SDA 2330 2331 If your arch supports the generic GPIO framework (asm/gpio.h), 2332 then you may alternatively define the two GPIOs that are to be 2333 used as SCL / SDA. Any of the previous I2C_xxx macros will 2334 have GPIO-based defaults assigned to them as appropriate. 2335 2336 You should define these to the GPIO value as given directly to 2337 the generic GPIO functions. 2338 2339 CONFIG_SYS_I2C_INIT_BOARD 2340 2341 When a board is reset during an i2c bus transfer 2342 chips might think that the current transfer is still 2343 in progress. On some boards it is possible to access 2344 the i2c SCLK line directly, either by using the 2345 processor pin as a GPIO or by having a second pin 2346 connected to the bus. If this option is defined a 2347 custom i2c_init_board() routine in boards/xxx/board.c 2348 is run early in the boot sequence. 2349 2350 CONFIG_SYS_I2C_BOARD_LATE_INIT 2351 2352 An alternative to CONFIG_SYS_I2C_INIT_BOARD. If this option is 2353 defined a custom i2c_board_late_init() routine in 2354 boards/xxx/board.c is run AFTER the operations in i2c_init() 2355 is completed. This callpoint can be used to unreset i2c bus 2356 using CPU i2c controller register accesses for CPUs whose i2c 2357 controller provide such a method. It is called at the end of 2358 i2c_init() to allow i2c_init operations to setup the i2c bus 2359 controller on the CPU (e.g. setting bus speed & slave address). 2360 2361 CONFIG_I2CFAST (PPC405GP|PPC405EP only) 2362 2363 This option enables configuration of bi_iic_fast[] flags 2364 in u-boot bd_info structure based on u-boot environment 2365 variable "i2cfast". (see also i2cfast) 2366 2367 CONFIG_I2C_MULTI_BUS 2368 2369 This option allows the use of multiple I2C buses, each of which 2370 must have a controller. At any point in time, only one bus is 2371 active. To switch to a different bus, use the 'i2c dev' command. 2372 Note that bus numbering is zero-based. 2373 2374 CONFIG_SYS_I2C_NOPROBES 2375 2376 This option specifies a list of I2C devices that will be skipped 2377 when the 'i2c probe' command is issued. If CONFIG_I2C_MULTI_BUS 2378 is set, specify a list of bus-device pairs. Otherwise, specify 2379 a 1D array of device addresses 2380 2381 e.g. 2382 #undef CONFIG_I2C_MULTI_BUS 2383 #define CONFIG_SYS_I2C_NOPROBES {0x50,0x68} 2384 2385 will skip addresses 0x50 and 0x68 on a board with one I2C bus 2386 2387 #define CONFIG_I2C_MULTI_BUS 2388 #define CONFIG_SYS_I2C_NOPROBES {{0,0x50},{0,0x68},{1,0x54}} 2389 2390 will skip addresses 0x50 and 0x68 on bus 0 and address 0x54 on bus 1 2391 2392 CONFIG_SYS_SPD_BUS_NUM 2393 2394 If defined, then this indicates the I2C bus number for DDR SPD. 2395 If not defined, then U-Boot assumes that SPD is on I2C bus 0. 2396 2397 CONFIG_SYS_RTC_BUS_NUM 2398 2399 If defined, then this indicates the I2C bus number for the RTC. 2400 If not defined, then U-Boot assumes that RTC is on I2C bus 0. 2401 2402 CONFIG_SYS_DTT_BUS_NUM 2403 2404 If defined, then this indicates the I2C bus number for the DTT. 2405 If not defined, then U-Boot assumes that DTT is on I2C bus 0. 2406 2407 CONFIG_SYS_I2C_DTT_ADDR: 2408 2409 If defined, specifies the I2C address of the DTT device. 2410 If not defined, then U-Boot uses predefined value for 2411 specified DTT device. 2412 2413 CONFIG_SOFT_I2C_READ_REPEATED_START 2414 2415 defining this will force the i2c_read() function in 2416 the soft_i2c driver to perform an I2C repeated start 2417 between writing the address pointer and reading the 2418 data. If this define is omitted the default behaviour 2419 of doing a stop-start sequence will be used. Most I2C 2420 devices can use either method, but some require one or 2421 the other. 2422 2423- SPI Support: CONFIG_SPI 2424 2425 Enables SPI driver (so far only tested with 2426 SPI EEPROM, also an instance works with Crystal A/D and 2427 D/As on the SACSng board) 2428 2429 CONFIG_SH_SPI 2430 2431 Enables the driver for SPI controller on SuperH. Currently 2432 only SH7757 is supported. 2433 2434 CONFIG_SOFT_SPI 2435 2436 Enables a software (bit-bang) SPI driver rather than 2437 using hardware support. This is a general purpose 2438 driver that only requires three general I/O port pins 2439 (two outputs, one input) to function. If this is 2440 defined, the board configuration must define several 2441 SPI configuration items (port pins to use, etc). For 2442 an example, see include/configs/sacsng.h. 2443 2444 CONFIG_HARD_SPI 2445 2446 Enables a hardware SPI driver for general-purpose reads 2447 and writes. As with CONFIG_SOFT_SPI, the board configuration 2448 must define a list of chip-select function pointers. 2449 Currently supported on some MPC8xxx processors. For an 2450 example, see include/configs/mpc8349emds.h. 2451 2452 CONFIG_MXC_SPI 2453 2454 Enables the driver for the SPI controllers on i.MX and MXC 2455 SoCs. Currently i.MX31/35/51 are supported. 2456 2457 CONFIG_SYS_SPI_MXC_WAIT 2458 Timeout for waiting until spi transfer completed. 2459 default: (CONFIG_SYS_HZ/100) /* 10 ms */ 2460 2461- FPGA Support: CONFIG_FPGA 2462 2463 Enables FPGA subsystem. 2464 2465 CONFIG_FPGA_<vendor> 2466 2467 Enables support for specific chip vendors. 2468 (ALTERA, XILINX) 2469 2470 CONFIG_FPGA_<family> 2471 2472 Enables support for FPGA family. 2473 (SPARTAN2, SPARTAN3, VIRTEX2, CYCLONE2, ACEX1K, ACEX) 2474 2475 CONFIG_FPGA_COUNT 2476 2477 Specify the number of FPGA devices to support. 2478 2479 CONFIG_CMD_FPGA_LOADMK 2480 2481 Enable support for fpga loadmk command 2482 2483 CONFIG_CMD_FPGA_LOADP 2484 2485 Enable support for fpga loadp command - load partial bitstream 2486 2487 CONFIG_CMD_FPGA_LOADBP 2488 2489 Enable support for fpga loadbp command - load partial bitstream 2490 (Xilinx only) 2491 2492 CONFIG_SYS_FPGA_PROG_FEEDBACK 2493 2494 Enable printing of hash marks during FPGA configuration. 2495 2496 CONFIG_SYS_FPGA_CHECK_BUSY 2497 2498 Enable checks on FPGA configuration interface busy 2499 status by the configuration function. This option 2500 will require a board or device specific function to 2501 be written. 2502 2503 CONFIG_FPGA_DELAY 2504 2505 If defined, a function that provides delays in the FPGA 2506 configuration driver. 2507 2508 CONFIG_SYS_FPGA_CHECK_CTRLC 2509 Allow Control-C to interrupt FPGA configuration 2510 2511 CONFIG_SYS_FPGA_CHECK_ERROR 2512 2513 Check for configuration errors during FPGA bitfile 2514 loading. For example, abort during Virtex II 2515 configuration if the INIT_B line goes low (which 2516 indicated a CRC error). 2517 2518 CONFIG_SYS_FPGA_WAIT_INIT 2519 2520 Maximum time to wait for the INIT_B line to de-assert 2521 after PROB_B has been de-asserted during a Virtex II 2522 FPGA configuration sequence. The default time is 500 2523 ms. 2524 2525 CONFIG_SYS_FPGA_WAIT_BUSY 2526 2527 Maximum time to wait for BUSY to de-assert during 2528 Virtex II FPGA configuration. The default is 5 ms. 2529 2530 CONFIG_SYS_FPGA_WAIT_CONFIG 2531 2532 Time to wait after FPGA configuration. The default is 2533 200 ms. 2534 2535- Configuration Management: 2536 CONFIG_BUILD_TARGET 2537 2538 Some SoCs need special image types (e.g. U-Boot binary 2539 with a special header) as build targets. By defining 2540 CONFIG_BUILD_TARGET in the SoC / board header, this 2541 special image will be automatically built upon calling 2542 make / buildman. 2543 2544 CONFIG_IDENT_STRING 2545 2546 If defined, this string will be added to the U-Boot 2547 version information (U_BOOT_VERSION) 2548 2549- Vendor Parameter Protection: 2550 2551 U-Boot considers the values of the environment 2552 variables "serial#" (Board Serial Number) and 2553 "ethaddr" (Ethernet Address) to be parameters that 2554 are set once by the board vendor / manufacturer, and 2555 protects these variables from casual modification by 2556 the user. Once set, these variables are read-only, 2557 and write or delete attempts are rejected. You can 2558 change this behaviour: 2559 2560 If CONFIG_ENV_OVERWRITE is #defined in your config 2561 file, the write protection for vendor parameters is 2562 completely disabled. Anybody can change or delete 2563 these parameters. 2564 2565 Alternatively, if you define _both_ an ethaddr in the 2566 default env _and_ CONFIG_OVERWRITE_ETHADDR_ONCE, a default 2567 Ethernet address is installed in the environment, 2568 which can be changed exactly ONCE by the user. [The 2569 serial# is unaffected by this, i. e. it remains 2570 read-only.] 2571 2572 The same can be accomplished in a more flexible way 2573 for any variable by configuring the type of access 2574 to allow for those variables in the ".flags" variable 2575 or define CONFIG_ENV_FLAGS_LIST_STATIC. 2576 2577- Protected RAM: 2578 CONFIG_PRAM 2579 2580 Define this variable to enable the reservation of 2581 "protected RAM", i. e. RAM which is not overwritten 2582 by U-Boot. Define CONFIG_PRAM to hold the number of 2583 kB you want to reserve for pRAM. You can overwrite 2584 this default value by defining an environment 2585 variable "pram" to the number of kB you want to 2586 reserve. Note that the board info structure will 2587 still show the full amount of RAM. If pRAM is 2588 reserved, a new environment variable "mem" will 2589 automatically be defined to hold the amount of 2590 remaining RAM in a form that can be passed as boot 2591 argument to Linux, for instance like that: 2592 2593 setenv bootargs ... mem=\${mem} 2594 saveenv 2595 2596 This way you can tell Linux not to use this memory, 2597 either, which results in a memory region that will 2598 not be affected by reboots. 2599 2600 *WARNING* If your board configuration uses automatic 2601 detection of the RAM size, you must make sure that 2602 this memory test is non-destructive. So far, the 2603 following board configurations are known to be 2604 "pRAM-clean": 2605 2606 IVMS8, IVML24, SPD8xx, TQM8xxL, 2607 HERMES, IP860, RPXlite, LWMON, 2608 FLAGADM, TQM8260 2609 2610- Access to physical memory region (> 4GB) 2611 Some basic support is provided for operations on memory not 2612 normally accessible to U-Boot - e.g. some architectures 2613 support access to more than 4GB of memory on 32-bit 2614 machines using physical address extension or similar. 2615 Define CONFIG_PHYSMEM to access this basic support, which 2616 currently only supports clearing the memory. 2617 2618- Error Recovery: 2619 CONFIG_PANIC_HANG 2620 2621 Define this variable to stop the system in case of a 2622 fatal error, so that you have to reset it manually. 2623 This is probably NOT a good idea for an embedded 2624 system where you want the system to reboot 2625 automatically as fast as possible, but it may be 2626 useful during development since you can try to debug 2627 the conditions that lead to the situation. 2628 2629 CONFIG_NET_RETRY_COUNT 2630 2631 This variable defines the number of retries for 2632 network operations like ARP, RARP, TFTP, or BOOTP 2633 before giving up the operation. If not defined, a 2634 default value of 5 is used. 2635 2636 CONFIG_ARP_TIMEOUT 2637 2638 Timeout waiting for an ARP reply in milliseconds. 2639 2640 CONFIG_NFS_TIMEOUT 2641 2642 Timeout in milliseconds used in NFS protocol. 2643 If you encounter "ERROR: Cannot umount" in nfs command, 2644 try longer timeout such as 2645 #define CONFIG_NFS_TIMEOUT 10000UL 2646 2647- Command Interpreter: 2648 CONFIG_AUTO_COMPLETE 2649 2650 Enable auto completion of commands using TAB. 2651 2652 CONFIG_SYS_PROMPT_HUSH_PS2 2653 2654 This defines the secondary prompt string, which is 2655 printed when the command interpreter needs more input 2656 to complete a command. Usually "> ". 2657 2658 Note: 2659 2660 In the current implementation, the local variables 2661 space and global environment variables space are 2662 separated. Local variables are those you define by 2663 simply typing `name=value'. To access a local 2664 variable later on, you have write `$name' or 2665 `${name}'; to execute the contents of a variable 2666 directly type `$name' at the command prompt. 2667 2668 Global environment variables are those you use 2669 setenv/printenv to work with. To run a command stored 2670 in such a variable, you need to use the run command, 2671 and you must not use the '$' sign to access them. 2672 2673 To store commands and special characters in a 2674 variable, please use double quotation marks 2675 surrounding the whole text of the variable, instead 2676 of the backslashes before semicolons and special 2677 symbols. 2678 2679- Command Line Editing and History: 2680 CONFIG_CMDLINE_EDITING 2681 2682 Enable editing and History functions for interactive 2683 command line input operations 2684 2685- Command Line PS1/PS2 support: 2686 CONFIG_CMDLINE_PS_SUPPORT 2687 2688 Enable support for changing the command prompt string 2689 at run-time. Only static string is supported so far. 2690 The string is obtained from environment variables PS1 2691 and PS2. 2692 2693- Default Environment: 2694 CONFIG_EXTRA_ENV_SETTINGS 2695 2696 Define this to contain any number of null terminated 2697 strings (variable = value pairs) that will be part of 2698 the default environment compiled into the boot image. 2699 2700 For example, place something like this in your 2701 board's config file: 2702 2703 #define CONFIG_EXTRA_ENV_SETTINGS \ 2704 "myvar1=value1\0" \ 2705 "myvar2=value2\0" 2706 2707 Warning: This method is based on knowledge about the 2708 internal format how the environment is stored by the 2709 U-Boot code. This is NOT an official, exported 2710 interface! Although it is unlikely that this format 2711 will change soon, there is no guarantee either. 2712 You better know what you are doing here. 2713 2714 Note: overly (ab)use of the default environment is 2715 discouraged. Make sure to check other ways to preset 2716 the environment like the "source" command or the 2717 boot command first. 2718 2719 CONFIG_ENV_VARS_UBOOT_CONFIG 2720 2721 Define this in order to add variables describing the 2722 U-Boot build configuration to the default environment. 2723 These will be named arch, cpu, board, vendor, and soc. 2724 2725 Enabling this option will cause the following to be defined: 2726 2727 - CONFIG_SYS_ARCH 2728 - CONFIG_SYS_CPU 2729 - CONFIG_SYS_BOARD 2730 - CONFIG_SYS_VENDOR 2731 - CONFIG_SYS_SOC 2732 2733 CONFIG_ENV_VARS_UBOOT_RUNTIME_CONFIG 2734 2735 Define this in order to add variables describing certain 2736 run-time determined information about the hardware to the 2737 environment. These will be named board_name, board_rev. 2738 2739 CONFIG_DELAY_ENVIRONMENT 2740 2741 Normally the environment is loaded when the board is 2742 initialised so that it is available to U-Boot. This inhibits 2743 that so that the environment is not available until 2744 explicitly loaded later by U-Boot code. With CONFIG_OF_CONTROL 2745 this is instead controlled by the value of 2746 /config/load-environment. 2747 2748- DataFlash Support: 2749 CONFIG_HAS_DATAFLASH 2750 2751 Defining this option enables DataFlash features and 2752 allows to read/write in Dataflash via the standard 2753 commands cp, md... 2754 2755- Serial Flash support 2756 CONFIG_CMD_SF 2757 2758 Defining this option enables SPI flash commands 2759 'sf probe/read/write/erase/update'. 2760 2761 Usage requires an initial 'probe' to define the serial 2762 flash parameters, followed by read/write/erase/update 2763 commands. 2764 2765 The following defaults may be provided by the platform 2766 to handle the common case when only a single serial 2767 flash is present on the system. 2768 2769 CONFIG_SF_DEFAULT_BUS Bus identifier 2770 CONFIG_SF_DEFAULT_CS Chip-select 2771 CONFIG_SF_DEFAULT_MODE (see include/spi.h) 2772 CONFIG_SF_DEFAULT_SPEED in Hz 2773 2774 CONFIG_CMD_SF_TEST 2775 2776 Define this option to include a destructive SPI flash 2777 test ('sf test'). 2778 2779 CONFIG_SF_DUAL_FLASH Dual flash memories 2780 2781 Define this option to use dual flash support where two flash 2782 memories can be connected with a given cs line. 2783 Currently Xilinx Zynq qspi supports these type of connections. 2784 2785- SystemACE Support: 2786 CONFIG_SYSTEMACE 2787 2788 Adding this option adds support for Xilinx SystemACE 2789 chips attached via some sort of local bus. The address 2790 of the chip must also be defined in the 2791 CONFIG_SYS_SYSTEMACE_BASE macro. For example: 2792 2793 #define CONFIG_SYSTEMACE 2794 #define CONFIG_SYS_SYSTEMACE_BASE 0xf0000000 2795 2796 When SystemACE support is added, the "ace" device type 2797 becomes available to the fat commands, i.e. fatls. 2798 2799- TFTP Fixed UDP Port: 2800 CONFIG_TFTP_PORT 2801 2802 If this is defined, the environment variable tftpsrcp 2803 is used to supply the TFTP UDP source port value. 2804 If tftpsrcp isn't defined, the normal pseudo-random port 2805 number generator is used. 2806 2807 Also, the environment variable tftpdstp is used to supply 2808 the TFTP UDP destination port value. If tftpdstp isn't 2809 defined, the normal port 69 is used. 2810 2811 The purpose for tftpsrcp is to allow a TFTP server to 2812 blindly start the TFTP transfer using the pre-configured 2813 target IP address and UDP port. This has the effect of 2814 "punching through" the (Windows XP) firewall, allowing 2815 the remainder of the TFTP transfer to proceed normally. 2816 A better solution is to properly configure the firewall, 2817 but sometimes that is not allowed. 2818 2819- Hashing support: 2820 CONFIG_CMD_HASH 2821 2822 This enables a generic 'hash' command which can produce 2823 hashes / digests from a few algorithms (e.g. SHA1, SHA256). 2824 2825 CONFIG_HASH_VERIFY 2826 2827 Enable the hash verify command (hash -v). This adds to code 2828 size a little. 2829 2830 CONFIG_SHA1 - This option enables support of hashing using SHA1 2831 algorithm. The hash is calculated in software. 2832 CONFIG_SHA256 - This option enables support of hashing using 2833 SHA256 algorithm. The hash is calculated in software. 2834 CONFIG_SHA_HW_ACCEL - This option enables hardware acceleration 2835 for SHA1/SHA256 hashing. 2836 This affects the 'hash' command and also the 2837 hash_lookup_algo() function. 2838 CONFIG_SHA_PROG_HW_ACCEL - This option enables 2839 hardware-acceleration for SHA1/SHA256 progressive hashing. 2840 Data can be streamed in a block at a time and the hashing 2841 is performed in hardware. 2842 2843 Note: There is also a sha1sum command, which should perhaps 2844 be deprecated in favour of 'hash sha1'. 2845 2846- Freescale i.MX specific commands: 2847 CONFIG_CMD_HDMIDETECT 2848 This enables 'hdmidet' command which returns true if an 2849 HDMI monitor is detected. This command is i.MX 6 specific. 2850 2851 CONFIG_CMD_BMODE 2852 This enables the 'bmode' (bootmode) command for forcing 2853 a boot from specific media. 2854 2855 This is useful for forcing the ROM's usb downloader to 2856 activate upon a watchdog reset which is nice when iterating 2857 on U-Boot. Using the reset button or running bmode normal 2858 will set it back to normal. This command currently 2859 supports i.MX53 and i.MX6. 2860 2861- bootcount support: 2862 CONFIG_BOOTCOUNT_LIMIT 2863 2864 This enables the bootcounter support, see: 2865 http://www.denx.de/wiki/DULG/UBootBootCountLimit 2866 2867 CONFIG_AT91SAM9XE 2868 enable special bootcounter support on at91sam9xe based boards. 2869 CONFIG_SOC_DA8XX 2870 enable special bootcounter support on da850 based boards. 2871 CONFIG_BOOTCOUNT_RAM 2872 enable support for the bootcounter in RAM 2873 CONFIG_BOOTCOUNT_I2C 2874 enable support for the bootcounter on an i2c (like RTC) device. 2875 CONFIG_SYS_I2C_RTC_ADDR = i2c chip address 2876 CONFIG_SYS_BOOTCOUNT_ADDR = i2c addr which is used for 2877 the bootcounter. 2878 CONFIG_BOOTCOUNT_ALEN = address len 2879 2880- Show boot progress: 2881 CONFIG_SHOW_BOOT_PROGRESS 2882 2883 Defining this option allows to add some board- 2884 specific code (calling a user-provided function 2885 "show_boot_progress(int)") that enables you to show 2886 the system's boot progress on some display (for 2887 example, some LED's) on your board. At the moment, 2888 the following checkpoints are implemented: 2889 2890 2891Legacy uImage format: 2892 2893 Arg Where When 2894 1 common/cmd_bootm.c before attempting to boot an image 2895 -1 common/cmd_bootm.c Image header has bad magic number 2896 2 common/cmd_bootm.c Image header has correct magic number 2897 -2 common/cmd_bootm.c Image header has bad checksum 2898 3 common/cmd_bootm.c Image header has correct checksum 2899 -3 common/cmd_bootm.c Image data has bad checksum 2900 4 common/cmd_bootm.c Image data has correct checksum 2901 -4 common/cmd_bootm.c Image is for unsupported architecture 2902 5 common/cmd_bootm.c Architecture check OK 2903 -5 common/cmd_bootm.c Wrong Image Type (not kernel, multi) 2904 6 common/cmd_bootm.c Image Type check OK 2905 -6 common/cmd_bootm.c gunzip uncompression error 2906 -7 common/cmd_bootm.c Unimplemented compression type 2907 7 common/cmd_bootm.c Uncompression OK 2908 8 common/cmd_bootm.c No uncompress/copy overwrite error 2909 -9 common/cmd_bootm.c Unsupported OS (not Linux, BSD, VxWorks, QNX) 2910 2911 9 common/image.c Start initial ramdisk verification 2912 -10 common/image.c Ramdisk header has bad magic number 2913 -11 common/image.c Ramdisk header has bad checksum 2914 10 common/image.c Ramdisk header is OK 2915 -12 common/image.c Ramdisk data has bad checksum 2916 11 common/image.c Ramdisk data has correct checksum 2917 12 common/image.c Ramdisk verification complete, start loading 2918 -13 common/image.c Wrong Image Type (not PPC Linux ramdisk) 2919 13 common/image.c Start multifile image verification 2920 14 common/image.c No initial ramdisk, no multifile, continue. 2921 2922 15 arch/<arch>/lib/bootm.c All preparation done, transferring control to OS 2923 2924 -30 arch/powerpc/lib/board.c Fatal error, hang the system 2925 -31 post/post.c POST test failed, detected by post_output_backlog() 2926 -32 post/post.c POST test failed, detected by post_run_single() 2927 2928 34 common/cmd_doc.c before loading a Image from a DOC device 2929 -35 common/cmd_doc.c Bad usage of "doc" command 2930 35 common/cmd_doc.c correct usage of "doc" command 2931 -36 common/cmd_doc.c No boot device 2932 36 common/cmd_doc.c correct boot device 2933 -37 common/cmd_doc.c Unknown Chip ID on boot device 2934 37 common/cmd_doc.c correct chip ID found, device available 2935 -38 common/cmd_doc.c Read Error on boot device 2936 38 common/cmd_doc.c reading Image header from DOC device OK 2937 -39 common/cmd_doc.c Image header has bad magic number 2938 39 common/cmd_doc.c Image header has correct magic number 2939 -40 common/cmd_doc.c Error reading Image from DOC device 2940 40 common/cmd_doc.c Image header has correct magic number 2941 41 common/cmd_ide.c before loading a Image from a IDE device 2942 -42 common/cmd_ide.c Bad usage of "ide" command 2943 42 common/cmd_ide.c correct usage of "ide" command 2944 -43 common/cmd_ide.c No boot device 2945 43 common/cmd_ide.c boot device found 2946 -44 common/cmd_ide.c Device not available 2947 44 common/cmd_ide.c Device available 2948 -45 common/cmd_ide.c wrong partition selected 2949 45 common/cmd_ide.c partition selected 2950 -46 common/cmd_ide.c Unknown partition table 2951 46 common/cmd_ide.c valid partition table found 2952 -47 common/cmd_ide.c Invalid partition type 2953 47 common/cmd_ide.c correct partition type 2954 -48 common/cmd_ide.c Error reading Image Header on boot device 2955 48 common/cmd_ide.c reading Image Header from IDE device OK 2956 -49 common/cmd_ide.c Image header has bad magic number 2957 49 common/cmd_ide.c Image header has correct magic number 2958 -50 common/cmd_ide.c Image header has bad checksum 2959 50 common/cmd_ide.c Image header has correct checksum 2960 -51 common/cmd_ide.c Error reading Image from IDE device 2961 51 common/cmd_ide.c reading Image from IDE device OK 2962 52 common/cmd_nand.c before loading a Image from a NAND device 2963 -53 common/cmd_nand.c Bad usage of "nand" command 2964 53 common/cmd_nand.c correct usage of "nand" command 2965 -54 common/cmd_nand.c No boot device 2966 54 common/cmd_nand.c boot device found 2967 -55 common/cmd_nand.c Unknown Chip ID on boot device 2968 55 common/cmd_nand.c correct chip ID found, device available 2969 -56 common/cmd_nand.c Error reading Image Header on boot device 2970 56 common/cmd_nand.c reading Image Header from NAND device OK 2971 -57 common/cmd_nand.c Image header has bad magic number 2972 57 common/cmd_nand.c Image header has correct magic number 2973 -58 common/cmd_nand.c Error reading Image from NAND device 2974 58 common/cmd_nand.c reading Image from NAND device OK 2975 2976 -60 common/env_common.c Environment has a bad CRC, using default 2977 2978 64 net/eth.c starting with Ethernet configuration. 2979 -64 net/eth.c no Ethernet found. 2980 65 net/eth.c Ethernet found. 2981 2982 -80 common/cmd_net.c usage wrong 2983 80 common/cmd_net.c before calling net_loop() 2984 -81 common/cmd_net.c some error in net_loop() occurred 2985 81 common/cmd_net.c net_loop() back without error 2986 -82 common/cmd_net.c size == 0 (File with size 0 loaded) 2987 82 common/cmd_net.c trying automatic boot 2988 83 common/cmd_net.c running "source" command 2989 -83 common/cmd_net.c some error in automatic boot or "source" command 2990 84 common/cmd_net.c end without errors 2991 2992FIT uImage format: 2993 2994 Arg Where When 2995 100 common/cmd_bootm.c Kernel FIT Image has correct format 2996 -100 common/cmd_bootm.c Kernel FIT Image has incorrect format 2997 101 common/cmd_bootm.c No Kernel subimage unit name, using configuration 2998 -101 common/cmd_bootm.c Can't get configuration for kernel subimage 2999 102 common/cmd_bootm.c Kernel unit name specified 3000 -103 common/cmd_bootm.c Can't get kernel subimage node offset 3001 103 common/cmd_bootm.c Found configuration node 3002 104 common/cmd_bootm.c Got kernel subimage node offset 3003 -104 common/cmd_bootm.c Kernel subimage hash verification failed 3004 105 common/cmd_bootm.c Kernel subimage hash verification OK 3005 -105 common/cmd_bootm.c Kernel subimage is for unsupported architecture 3006 106 common/cmd_bootm.c Architecture check OK 3007 -106 common/cmd_bootm.c Kernel subimage has wrong type 3008 107 common/cmd_bootm.c Kernel subimage type OK 3009 -107 common/cmd_bootm.c Can't get kernel subimage data/size 3010 108 common/cmd_bootm.c Got kernel subimage data/size 3011 -108 common/cmd_bootm.c Wrong image type (not legacy, FIT) 3012 -109 common/cmd_bootm.c Can't get kernel subimage type 3013 -110 common/cmd_bootm.c Can't get kernel subimage comp 3014 -111 common/cmd_bootm.c Can't get kernel subimage os 3015 -112 common/cmd_bootm.c Can't get kernel subimage load address 3016 -113 common/cmd_bootm.c Image uncompress/copy overwrite error 3017 3018 120 common/image.c Start initial ramdisk verification 3019 -120 common/image.c Ramdisk FIT image has incorrect format 3020 121 common/image.c Ramdisk FIT image has correct format 3021 122 common/image.c No ramdisk subimage unit name, using configuration 3022 -122 common/image.c Can't get configuration for ramdisk subimage 3023 123 common/image.c Ramdisk unit name specified 3024 -124 common/image.c Can't get ramdisk subimage node offset 3025 125 common/image.c Got ramdisk subimage node offset 3026 -125 common/image.c Ramdisk subimage hash verification failed 3027 126 common/image.c Ramdisk subimage hash verification OK 3028 -126 common/image.c Ramdisk subimage for unsupported architecture 3029 127 common/image.c Architecture check OK 3030 -127 common/image.c Can't get ramdisk subimage data/size 3031 128 common/image.c Got ramdisk subimage data/size 3032 129 common/image.c Can't get ramdisk load address 3033 -129 common/image.c Got ramdisk load address 3034 3035 -130 common/cmd_doc.c Incorrect FIT image format 3036 131 common/cmd_doc.c FIT image format OK 3037 3038 -140 common/cmd_ide.c Incorrect FIT image format 3039 141 common/cmd_ide.c FIT image format OK 3040 3041 -150 common/cmd_nand.c Incorrect FIT image format 3042 151 common/cmd_nand.c FIT image format OK 3043 3044- legacy image format: 3045 CONFIG_IMAGE_FORMAT_LEGACY 3046 enables the legacy image format support in U-Boot. 3047 3048 Default: 3049 enabled if CONFIG_FIT_SIGNATURE is not defined. 3050 3051 CONFIG_DISABLE_IMAGE_LEGACY 3052 disable the legacy image format 3053 3054 This define is introduced, as the legacy image format is 3055 enabled per default for backward compatibility. 3056 3057- FIT image support: 3058 CONFIG_FIT_DISABLE_SHA256 3059 Supporting SHA256 hashes has quite an impact on binary size. 3060 For constrained systems sha256 hash support can be disabled 3061 with this option. 3062 3063 TODO(sjg@chromium.org): Adjust this option to be positive, 3064 and move it to Kconfig 3065 3066- Standalone program support: 3067 CONFIG_STANDALONE_LOAD_ADDR 3068 3069 This option defines a board specific value for the 3070 address where standalone program gets loaded, thus 3071 overwriting the architecture dependent default 3072 settings. 3073 3074- Frame Buffer Address: 3075 CONFIG_FB_ADDR 3076 3077 Define CONFIG_FB_ADDR if you want to use specific 3078 address for frame buffer. This is typically the case 3079 when using a graphics controller has separate video 3080 memory. U-Boot will then place the frame buffer at 3081 the given address instead of dynamically reserving it 3082 in system RAM by calling lcd_setmem(), which grabs 3083 the memory for the frame buffer depending on the 3084 configured panel size. 3085 3086 Please see board_init_f function. 3087 3088- Automatic software updates via TFTP server 3089 CONFIG_UPDATE_TFTP 3090 CONFIG_UPDATE_TFTP_CNT_MAX 3091 CONFIG_UPDATE_TFTP_MSEC_MAX 3092 3093 These options enable and control the auto-update feature; 3094 for a more detailed description refer to doc/README.update. 3095 3096- MTD Support (mtdparts command, UBI support) 3097 CONFIG_MTD_DEVICE 3098 3099 Adds the MTD device infrastructure from the Linux kernel. 3100 Needed for mtdparts command support. 3101 3102 CONFIG_MTD_PARTITIONS 3103 3104 Adds the MTD partitioning infrastructure from the Linux 3105 kernel. Needed for UBI support. 3106 3107- UBI support 3108 CONFIG_CMD_UBI 3109 3110 Adds commands for interacting with MTD partitions formatted 3111 with the UBI flash translation layer 3112 3113 Requires also defining CONFIG_RBTREE 3114 3115 CONFIG_UBI_SILENCE_MSG 3116 3117 Make the verbose messages from UBI stop printing. This leaves 3118 warnings and errors enabled. 3119 3120 3121 CONFIG_MTD_UBI_WL_THRESHOLD 3122 This parameter defines the maximum difference between the highest 3123 erase counter value and the lowest erase counter value of eraseblocks 3124 of UBI devices. When this threshold is exceeded, UBI starts performing 3125 wear leveling by means of moving data from eraseblock with low erase 3126 counter to eraseblocks with high erase counter. 3127 3128 The default value should be OK for SLC NAND flashes, NOR flashes and 3129 other flashes which have eraseblock life-cycle 100000 or more. 3130 However, in case of MLC NAND flashes which typically have eraseblock 3131 life-cycle less than 10000, the threshold should be lessened (e.g., 3132 to 128 or 256, although it does not have to be power of 2). 3133 3134 default: 4096 3135 3136 CONFIG_MTD_UBI_BEB_LIMIT 3137 This option specifies the maximum bad physical eraseblocks UBI 3138 expects on the MTD device (per 1024 eraseblocks). If the 3139 underlying flash does not admit of bad eraseblocks (e.g. NOR 3140 flash), this value is ignored. 3141 3142 NAND datasheets often specify the minimum and maximum NVM 3143 (Number of Valid Blocks) for the flashes' endurance lifetime. 3144 The maximum expected bad eraseblocks per 1024 eraseblocks 3145 then can be calculated as "1024 * (1 - MinNVB / MaxNVB)", 3146 which gives 20 for most NANDs (MaxNVB is basically the total 3147 count of eraseblocks on the chip). 3148 3149 To put it differently, if this value is 20, UBI will try to 3150 reserve about 1.9% of physical eraseblocks for bad blocks 3151 handling. And that will be 1.9% of eraseblocks on the entire 3152 NAND chip, not just the MTD partition UBI attaches. This means 3153 that if you have, say, a NAND flash chip admits maximum 40 bad 3154 eraseblocks, and it is split on two MTD partitions of the same 3155 size, UBI will reserve 40 eraseblocks when attaching a 3156 partition. 3157 3158 default: 20 3159 3160 CONFIG_MTD_UBI_FASTMAP 3161 Fastmap is a mechanism which allows attaching an UBI device 3162 in nearly constant time. Instead of scanning the whole MTD device it 3163 only has to locate a checkpoint (called fastmap) on the device. 3164 The on-flash fastmap contains all information needed to attach 3165 the device. Using fastmap makes only sense on large devices where 3166 attaching by scanning takes long. UBI will not automatically install 3167 a fastmap on old images, but you can set the UBI parameter 3168 CONFIG_MTD_UBI_FASTMAP_AUTOCONVERT to 1 if you want so. Please note 3169 that fastmap-enabled images are still usable with UBI implementations 3170 without fastmap support. On typical flash devices the whole fastmap 3171 fits into one PEB. UBI will reserve PEBs to hold two fastmaps. 3172 3173 CONFIG_MTD_UBI_FASTMAP_AUTOCONVERT 3174 Set this parameter to enable fastmap automatically on images 3175 without a fastmap. 3176 default: 0 3177 3178 CONFIG_MTD_UBI_FM_DEBUG 3179 Enable UBI fastmap debug 3180 default: 0 3181 3182- UBIFS support 3183 CONFIG_CMD_UBIFS 3184 3185 Adds commands for interacting with UBI volumes formatted as 3186 UBIFS. UBIFS is read-only in u-boot. 3187 3188 Requires UBI support as well as CONFIG_LZO 3189 3190 CONFIG_UBIFS_SILENCE_MSG 3191 3192 Make the verbose messages from UBIFS stop printing. This leaves 3193 warnings and errors enabled. 3194 3195- SPL framework 3196 CONFIG_SPL 3197 Enable building of SPL globally. 3198 3199 CONFIG_SPL_LDSCRIPT 3200 LDSCRIPT for linking the SPL binary. 3201 3202 CONFIG_SPL_MAX_FOOTPRINT 3203 Maximum size in memory allocated to the SPL, BSS included. 3204 When defined, the linker checks that the actual memory 3205 used by SPL from _start to __bss_end does not exceed it. 3206 CONFIG_SPL_MAX_FOOTPRINT and CONFIG_SPL_BSS_MAX_SIZE 3207 must not be both defined at the same time. 3208 3209 CONFIG_SPL_MAX_SIZE 3210 Maximum size of the SPL image (text, data, rodata, and 3211 linker lists sections), BSS excluded. 3212 When defined, the linker checks that the actual size does 3213 not exceed it. 3214 3215 CONFIG_SPL_TEXT_BASE 3216 TEXT_BASE for linking the SPL binary. 3217 3218 CONFIG_SPL_RELOC_TEXT_BASE 3219 Address to relocate to. If unspecified, this is equal to 3220 CONFIG_SPL_TEXT_BASE (i.e. no relocation is done). 3221 3222 CONFIG_SPL_BSS_START_ADDR 3223 Link address for the BSS within the SPL binary. 3224 3225 CONFIG_SPL_BSS_MAX_SIZE 3226 Maximum size in memory allocated to the SPL BSS. 3227 When defined, the linker checks that the actual memory used 3228 by SPL from __bss_start to __bss_end does not exceed it. 3229 CONFIG_SPL_MAX_FOOTPRINT and CONFIG_SPL_BSS_MAX_SIZE 3230 must not be both defined at the same time. 3231 3232 CONFIG_SPL_STACK 3233 Adress of the start of the stack SPL will use 3234 3235 CONFIG_SPL_PANIC_ON_RAW_IMAGE 3236 When defined, SPL will panic() if the image it has 3237 loaded does not have a signature. 3238 Defining this is useful when code which loads images 3239 in SPL cannot guarantee that absolutely all read errors 3240 will be caught. 3241 An example is the LPC32XX MLC NAND driver, which will 3242 consider that a completely unreadable NAND block is bad, 3243 and thus should be skipped silently. 3244 3245 CONFIG_SPL_RELOC_STACK 3246 Adress of the start of the stack SPL will use after 3247 relocation. If unspecified, this is equal to 3248 CONFIG_SPL_STACK. 3249 3250 CONFIG_SYS_SPL_MALLOC_START 3251 Starting address of the malloc pool used in SPL. 3252 When this option is set the full malloc is used in SPL and 3253 it is set up by spl_init() and before that, the simple malloc() 3254 can be used if CONFIG_SYS_MALLOC_F is defined. 3255 3256 CONFIG_SYS_SPL_MALLOC_SIZE 3257 The size of the malloc pool used in SPL. 3258 3259 CONFIG_SPL_FRAMEWORK 3260 Enable the SPL framework under common/. This framework 3261 supports MMC, NAND and YMODEM loading of U-Boot and NAND 3262 NAND loading of the Linux Kernel. 3263 3264 CONFIG_SPL_OS_BOOT 3265 Enable booting directly to an OS from SPL. 3266 See also: doc/README.falcon 3267 3268 CONFIG_SPL_DISPLAY_PRINT 3269 For ARM, enable an optional function to print more information 3270 about the running system. 3271 3272 CONFIG_SPL_INIT_MINIMAL 3273 Arch init code should be built for a very small image 3274 3275 CONFIG_SYS_MMCSD_RAW_MODE_U_BOOT_PARTITION 3276 Partition on the MMC to load U-Boot from when the MMC is being 3277 used in raw mode 3278 3279 CONFIG_SYS_MMCSD_RAW_MODE_KERNEL_SECTOR 3280 Sector to load kernel uImage from when MMC is being 3281 used in raw mode (for Falcon mode) 3282 3283 CONFIG_SYS_MMCSD_RAW_MODE_ARGS_SECTOR, 3284 CONFIG_SYS_MMCSD_RAW_MODE_ARGS_SECTORS 3285 Sector and number of sectors to load kernel argument 3286 parameters from when MMC is being used in raw mode 3287 (for falcon mode) 3288 3289 CONFIG_SYS_MMCSD_FS_BOOT_PARTITION 3290 Partition on the MMC to load U-Boot from when the MMC is being 3291 used in fs mode 3292 3293 CONFIG_SPL_FS_LOAD_PAYLOAD_NAME 3294 Filename to read to load U-Boot when reading from filesystem 3295 3296 CONFIG_SPL_FS_LOAD_KERNEL_NAME 3297 Filename to read to load kernel uImage when reading 3298 from filesystem (for Falcon mode) 3299 3300 CONFIG_SPL_FS_LOAD_ARGS_NAME 3301 Filename to read to load kernel argument parameters 3302 when reading from filesystem (for Falcon mode) 3303 3304 CONFIG_SPL_MPC83XX_WAIT_FOR_NAND 3305 Set this for NAND SPL on PPC mpc83xx targets, so that 3306 start.S waits for the rest of the SPL to load before 3307 continuing (the hardware starts execution after just 3308 loading the first page rather than the full 4K). 3309 3310 CONFIG_SPL_SKIP_RELOCATE 3311 Avoid SPL relocation 3312 3313 CONFIG_SPL_NAND_BASE 3314 Include nand_base.c in the SPL. Requires 3315 CONFIG_SPL_NAND_DRIVERS. 3316 3317 CONFIG_SPL_NAND_DRIVERS 3318 SPL uses normal NAND drivers, not minimal drivers. 3319 3320 CONFIG_SPL_NAND_ECC 3321 Include standard software ECC in the SPL 3322 3323 CONFIG_SPL_NAND_SIMPLE 3324 Support for NAND boot using simple NAND drivers that 3325 expose the cmd_ctrl() interface. 3326 3327 CONFIG_SPL_UBI 3328 Support for a lightweight UBI (fastmap) scanner and 3329 loader 3330 3331 CONFIG_SPL_NAND_RAW_ONLY 3332 Support to boot only raw u-boot.bin images. Use this only 3333 if you need to save space. 3334 3335 CONFIG_SPL_COMMON_INIT_DDR 3336 Set for common ddr init with serial presence detect in 3337 SPL binary. 3338 3339 CONFIG_SYS_NAND_5_ADDR_CYCLE, CONFIG_SYS_NAND_PAGE_COUNT, 3340 CONFIG_SYS_NAND_PAGE_SIZE, CONFIG_SYS_NAND_OOBSIZE, 3341 CONFIG_SYS_NAND_BLOCK_SIZE, CONFIG_SYS_NAND_BAD_BLOCK_POS, 3342 CONFIG_SYS_NAND_ECCPOS, CONFIG_SYS_NAND_ECCSIZE, 3343 CONFIG_SYS_NAND_ECCBYTES 3344 Defines the size and behavior of the NAND that SPL uses 3345 to read U-Boot 3346 3347 CONFIG_SPL_NAND_BOOT 3348 Add support NAND boot 3349 3350 CONFIG_SYS_NAND_U_BOOT_OFFS 3351 Location in NAND to read U-Boot from 3352 3353 CONFIG_SYS_NAND_U_BOOT_DST 3354 Location in memory to load U-Boot to 3355 3356 CONFIG_SYS_NAND_U_BOOT_SIZE 3357 Size of image to load 3358 3359 CONFIG_SYS_NAND_U_BOOT_START 3360 Entry point in loaded image to jump to 3361 3362 CONFIG_SYS_NAND_HW_ECC_OOBFIRST 3363 Define this if you need to first read the OOB and then the 3364 data. This is used, for example, on davinci platforms. 3365 3366 CONFIG_SPL_OMAP3_ID_NAND 3367 Support for an OMAP3-specific set of functions to return the 3368 ID and MFR of the first attached NAND chip, if present. 3369 3370 CONFIG_SPL_RAM_DEVICE 3371 Support for running image already present in ram, in SPL binary 3372 3373 CONFIG_SPL_PAD_TO 3374 Image offset to which the SPL should be padded before appending 3375 the SPL payload. By default, this is defined as 3376 CONFIG_SPL_MAX_SIZE, or 0 if CONFIG_SPL_MAX_SIZE is undefined. 3377 CONFIG_SPL_PAD_TO must be either 0, meaning to append the SPL 3378 payload without any padding, or >= CONFIG_SPL_MAX_SIZE. 3379 3380 CONFIG_SPL_TARGET 3381 Final target image containing SPL and payload. Some SPLs 3382 use an arch-specific makefile fragment instead, for 3383 example if more than one image needs to be produced. 3384 3385 CONFIG_FIT_SPL_PRINT 3386 Printing information about a FIT image adds quite a bit of 3387 code to SPL. So this is normally disabled in SPL. Use this 3388 option to re-enable it. This will affect the output of the 3389 bootm command when booting a FIT image. 3390 3391- TPL framework 3392 CONFIG_TPL 3393 Enable building of TPL globally. 3394 3395 CONFIG_TPL_PAD_TO 3396 Image offset to which the TPL should be padded before appending 3397 the TPL payload. By default, this is defined as 3398 CONFIG_SPL_MAX_SIZE, or 0 if CONFIG_SPL_MAX_SIZE is undefined. 3399 CONFIG_SPL_PAD_TO must be either 0, meaning to append the SPL 3400 payload without any padding, or >= CONFIG_SPL_MAX_SIZE. 3401 3402- Interrupt support (PPC): 3403 3404 There are common interrupt_init() and timer_interrupt() 3405 for all PPC archs. interrupt_init() calls interrupt_init_cpu() 3406 for CPU specific initialization. interrupt_init_cpu() 3407 should set decrementer_count to appropriate value. If 3408 CPU resets decrementer automatically after interrupt 3409 (ppc4xx) it should set decrementer_count to zero. 3410 timer_interrupt() calls timer_interrupt_cpu() for CPU 3411 specific handling. If board has watchdog / status_led 3412 / other_activity_monitor it works automatically from 3413 general timer_interrupt(). 3414 3415 3416Board initialization settings: 3417------------------------------ 3418 3419During Initialization u-boot calls a number of board specific functions 3420to allow the preparation of board specific prerequisites, e.g. pin setup 3421before drivers are initialized. To enable these callbacks the 3422following configuration macros have to be defined. Currently this is 3423architecture specific, so please check arch/your_architecture/lib/board.c 3424typically in board_init_f() and board_init_r(). 3425 3426- CONFIG_BOARD_EARLY_INIT_F: Call board_early_init_f() 3427- CONFIG_BOARD_EARLY_INIT_R: Call board_early_init_r() 3428- CONFIG_BOARD_LATE_INIT: Call board_late_init() 3429- CONFIG_BOARD_POSTCLK_INIT: Call board_postclk_init() 3430 3431Configuration Settings: 3432----------------------- 3433 3434- CONFIG_SYS_SUPPORT_64BIT_DATA: Defined automatically if compiled as 64-bit. 3435 Optionally it can be defined to support 64-bit memory commands. 3436 3437- CONFIG_SYS_LONGHELP: Defined when you want long help messages included; 3438 undefine this when you're short of memory. 3439 3440- CONFIG_SYS_HELP_CMD_WIDTH: Defined when you want to override the default 3441 width of the commands listed in the 'help' command output. 3442 3443- CONFIG_SYS_PROMPT: This is what U-Boot prints on the console to 3444 prompt for user input. 3445 3446- CONFIG_SYS_CBSIZE: Buffer size for input from the Console 3447 3448- CONFIG_SYS_PBSIZE: Buffer size for Console output 3449 3450- CONFIG_SYS_MAXARGS: max. Number of arguments accepted for monitor commands 3451 3452- CONFIG_SYS_BARGSIZE: Buffer size for Boot Arguments which are passed to 3453 the application (usually a Linux kernel) when it is 3454 booted 3455 3456- CONFIG_SYS_BAUDRATE_TABLE: 3457 List of legal baudrate settings for this board. 3458 3459- CONFIG_SYS_MEMTEST_START, CONFIG_SYS_MEMTEST_END: 3460 Begin and End addresses of the area used by the 3461 simple memory test. 3462 3463- CONFIG_SYS_ALT_MEMTEST: 3464 Enable an alternate, more extensive memory test. 3465 3466- CONFIG_SYS_MEMTEST_SCRATCH: 3467 Scratch address used by the alternate memory test 3468 You only need to set this if address zero isn't writeable 3469 3470- CONFIG_SYS_MEM_RESERVE_SECURE 3471 Only implemented for ARMv8 for now. 3472 If defined, the size of CONFIG_SYS_MEM_RESERVE_SECURE memory 3473 is substracted from total RAM and won't be reported to OS. 3474 This memory can be used as secure memory. A variable 3475 gd->arch.secure_ram is used to track the location. In systems 3476 the RAM base is not zero, or RAM is divided into banks, 3477 this variable needs to be recalcuated to get the address. 3478 3479- CONFIG_SYS_MEM_TOP_HIDE: 3480 If CONFIG_SYS_MEM_TOP_HIDE is defined in the board config header, 3481 this specified memory area will get subtracted from the top 3482 (end) of RAM and won't get "touched" at all by U-Boot. By 3483 fixing up gd->ram_size the Linux kernel should gets passed 3484 the now "corrected" memory size and won't touch it either. 3485 This should work for arch/ppc and arch/powerpc. Only Linux 3486 board ports in arch/powerpc with bootwrapper support that 3487 recalculate the memory size from the SDRAM controller setup 3488 will have to get fixed in Linux additionally. 3489 3490 This option can be used as a workaround for the 440EPx/GRx 3491 CHIP 11 errata where the last 256 bytes in SDRAM shouldn't 3492 be touched. 3493 3494 WARNING: Please make sure that this value is a multiple of 3495 the Linux page size (normally 4k). If this is not the case, 3496 then the end address of the Linux memory will be located at a 3497 non page size aligned address and this could cause major 3498 problems. 3499 3500- CONFIG_SYS_LOADS_BAUD_CHANGE: 3501 Enable temporary baudrate change while serial download 3502 3503- CONFIG_SYS_SDRAM_BASE: 3504 Physical start address of SDRAM. _Must_ be 0 here. 3505 3506- CONFIG_SYS_FLASH_BASE: 3507 Physical start address of Flash memory. 3508 3509- CONFIG_SYS_MONITOR_BASE: 3510 Physical start address of boot monitor code (set by 3511 make config files to be same as the text base address 3512 (CONFIG_SYS_TEXT_BASE) used when linking) - same as 3513 CONFIG_SYS_FLASH_BASE when booting from flash. 3514 3515- CONFIG_SYS_MONITOR_LEN: 3516 Size of memory reserved for monitor code, used to 3517 determine _at_compile_time_ (!) if the environment is 3518 embedded within the U-Boot image, or in a separate 3519 flash sector. 3520 3521- CONFIG_SYS_MALLOC_LEN: 3522 Size of DRAM reserved for malloc() use. 3523 3524- CONFIG_SYS_MALLOC_F_LEN 3525 Size of the malloc() pool for use before relocation. If 3526 this is defined, then a very simple malloc() implementation 3527 will become available before relocation. The address is just 3528 below the global data, and the stack is moved down to make 3529 space. 3530 3531 This feature allocates regions with increasing addresses 3532 within the region. calloc() is supported, but realloc() 3533 is not available. free() is supported but does nothing. 3534 The memory will be freed (or in fact just forgotten) when 3535 U-Boot relocates itself. 3536 3537- CONFIG_SYS_MALLOC_SIMPLE 3538 Provides a simple and small malloc() and calloc() for those 3539 boards which do not use the full malloc in SPL (which is 3540 enabled with CONFIG_SYS_SPL_MALLOC_START). 3541 3542- CONFIG_SYS_NONCACHED_MEMORY: 3543 Size of non-cached memory area. This area of memory will be 3544 typically located right below the malloc() area and mapped 3545 uncached in the MMU. This is useful for drivers that would 3546 otherwise require a lot of explicit cache maintenance. For 3547 some drivers it's also impossible to properly maintain the 3548 cache. For example if the regions that need to be flushed 3549 are not a multiple of the cache-line size, *and* padding 3550 cannot be allocated between the regions to align them (i.e. 3551 if the HW requires a contiguous array of regions, and the 3552 size of each region is not cache-aligned), then a flush of 3553 one region may result in overwriting data that hardware has 3554 written to another region in the same cache-line. This can 3555 happen for example in network drivers where descriptors for 3556 buffers are typically smaller than the CPU cache-line (e.g. 3557 16 bytes vs. 32 or 64 bytes). 3558 3559 Non-cached memory is only supported on 32-bit ARM at present. 3560 3561- CONFIG_SYS_BOOTM_LEN: 3562 Normally compressed uImages are limited to an 3563 uncompressed size of 8 MBytes. If this is not enough, 3564 you can define CONFIG_SYS_BOOTM_LEN in your board config file 3565 to adjust this setting to your needs. 3566 3567- CONFIG_SYS_BOOTMAPSZ: 3568 Maximum size of memory mapped by the startup code of 3569 the Linux kernel; all data that must be processed by 3570 the Linux kernel (bd_info, boot arguments, FDT blob if 3571 used) must be put below this limit, unless "bootm_low" 3572 environment variable is defined and non-zero. In such case 3573 all data for the Linux kernel must be between "bootm_low" 3574 and "bootm_low" + CONFIG_SYS_BOOTMAPSZ. The environment 3575 variable "bootm_mapsize" will override the value of 3576 CONFIG_SYS_BOOTMAPSZ. If CONFIG_SYS_BOOTMAPSZ is undefined, 3577 then the value in "bootm_size" will be used instead. 3578 3579- CONFIG_SYS_BOOT_RAMDISK_HIGH: 3580 Enable initrd_high functionality. If defined then the 3581 initrd_high feature is enabled and the bootm ramdisk subcommand 3582 is enabled. 3583 3584- CONFIG_SYS_BOOT_GET_CMDLINE: 3585 Enables allocating and saving kernel cmdline in space between 3586 "bootm_low" and "bootm_low" + BOOTMAPSZ. 3587 3588- CONFIG_SYS_BOOT_GET_KBD: 3589 Enables allocating and saving a kernel copy of the bd_info in 3590 space between "bootm_low" and "bootm_low" + BOOTMAPSZ. 3591 3592- CONFIG_SYS_MAX_FLASH_BANKS: 3593 Max number of Flash memory banks 3594 3595- CONFIG_SYS_MAX_FLASH_SECT: 3596 Max number of sectors on a Flash chip 3597 3598- CONFIG_SYS_FLASH_ERASE_TOUT: 3599 Timeout for Flash erase operations (in ms) 3600 3601- CONFIG_SYS_FLASH_WRITE_TOUT: 3602 Timeout for Flash write operations (in ms) 3603 3604- CONFIG_SYS_FLASH_LOCK_TOUT 3605 Timeout for Flash set sector lock bit operation (in ms) 3606 3607- CONFIG_SYS_FLASH_UNLOCK_TOUT 3608 Timeout for Flash clear lock bits operation (in ms) 3609 3610- CONFIG_SYS_FLASH_PROTECTION 3611 If defined, hardware flash sectors protection is used 3612 instead of U-Boot software protection. 3613 3614- CONFIG_SYS_DIRECT_FLASH_TFTP: 3615 3616 Enable TFTP transfers directly to flash memory; 3617 without this option such a download has to be 3618 performed in two steps: (1) download to RAM, and (2) 3619 copy from RAM to flash. 3620 3621 The two-step approach is usually more reliable, since 3622 you can check if the download worked before you erase 3623 the flash, but in some situations (when system RAM is 3624 too limited to allow for a temporary copy of the 3625 downloaded image) this option may be very useful. 3626 3627- CONFIG_SYS_FLASH_CFI: 3628 Define if the flash driver uses extra elements in the 3629 common flash structure for storing flash geometry. 3630 3631- CONFIG_FLASH_CFI_DRIVER 3632 This option also enables the building of the cfi_flash driver 3633 in the drivers directory 3634 3635- CONFIG_FLASH_CFI_MTD 3636 This option enables the building of the cfi_mtd driver 3637 in the drivers directory. The driver exports CFI flash 3638 to the MTD layer. 3639 3640- CONFIG_SYS_FLASH_USE_BUFFER_WRITE 3641 Use buffered writes to flash. 3642 3643- CONFIG_FLASH_SPANSION_S29WS_N 3644 s29ws-n MirrorBit flash has non-standard addresses for buffered 3645 write commands. 3646 3647- CONFIG_SYS_FLASH_QUIET_TEST 3648 If this option is defined, the common CFI flash doesn't 3649 print it's warning upon not recognized FLASH banks. This 3650 is useful, if some of the configured banks are only 3651 optionally available. 3652 3653- CONFIG_FLASH_SHOW_PROGRESS 3654 If defined (must be an integer), print out countdown 3655 digits and dots. Recommended value: 45 (9..1) for 80 3656 column displays, 15 (3..1) for 40 column displays. 3657 3658- CONFIG_FLASH_VERIFY 3659 If defined, the content of the flash (destination) is compared 3660 against the source after the write operation. An error message 3661 will be printed when the contents are not identical. 3662 Please note that this option is useless in nearly all cases, 3663 since such flash programming errors usually are detected earlier 3664 while unprotecting/erasing/programming. Please only enable 3665 this option if you really know what you are doing. 3666 3667- CONFIG_SYS_RX_ETH_BUFFER: 3668 Defines the number of Ethernet receive buffers. On some 3669 Ethernet controllers it is recommended to set this value 3670 to 8 or even higher (EEPRO100 or 405 EMAC), since all 3671 buffers can be full shortly after enabling the interface 3672 on high Ethernet traffic. 3673 Defaults to 4 if not defined. 3674 3675- CONFIG_ENV_MAX_ENTRIES 3676 3677 Maximum number of entries in the hash table that is used 3678 internally to store the environment settings. The default 3679 setting is supposed to be generous and should work in most 3680 cases. This setting can be used to tune behaviour; see 3681 lib/hashtable.c for details. 3682 3683- CONFIG_ENV_FLAGS_LIST_DEFAULT 3684- CONFIG_ENV_FLAGS_LIST_STATIC 3685 Enable validation of the values given to environment variables when 3686 calling env set. Variables can be restricted to only decimal, 3687 hexadecimal, or boolean. If CONFIG_CMD_NET is also defined, 3688 the variables can also be restricted to IP address or MAC address. 3689 3690 The format of the list is: 3691 type_attribute = [s|d|x|b|i|m] 3692 access_attribute = [a|r|o|c] 3693 attributes = type_attribute[access_attribute] 3694 entry = variable_name[:attributes] 3695 list = entry[,list] 3696 3697 The type attributes are: 3698 s - String (default) 3699 d - Decimal 3700 x - Hexadecimal 3701 b - Boolean ([1yYtT|0nNfF]) 3702 i - IP address 3703 m - MAC address 3704 3705 The access attributes are: 3706 a - Any (default) 3707 r - Read-only 3708 o - Write-once 3709 c - Change-default 3710 3711 - CONFIG_ENV_FLAGS_LIST_DEFAULT 3712 Define this to a list (string) to define the ".flags" 3713 environment variable in the default or embedded environment. 3714 3715 - CONFIG_ENV_FLAGS_LIST_STATIC 3716 Define this to a list (string) to define validation that 3717 should be done if an entry is not found in the ".flags" 3718 environment variable. To override a setting in the static 3719 list, simply add an entry for the same variable name to the 3720 ".flags" variable. 3721 3722 If CONFIG_REGEX is defined, the variable_name above is evaluated as a 3723 regular expression. This allows multiple variables to define the same 3724 flags without explicitly listing them for each variable. 3725 3726- CONFIG_ENV_ACCESS_IGNORE_FORCE 3727 If defined, don't allow the -f switch to env set override variable 3728 access flags. 3729 3730- CONFIG_OMAP_PLATFORM_RESET_TIME_MAX_USEC (OMAP only) 3731 This is set by OMAP boards for the max time that reset should 3732 be asserted. See doc/README.omap-reset-time for details on how 3733 the value can be calculated on a given board. 3734 3735- CONFIG_USE_STDINT 3736 If stdint.h is available with your toolchain you can define this 3737 option to enable it. You can provide option 'USE_STDINT=1' when 3738 building U-Boot to enable this. 3739 3740The following definitions that deal with the placement and management 3741of environment data (variable area); in general, we support the 3742following configurations: 3743 3744- CONFIG_BUILD_ENVCRC: 3745 3746 Builds up envcrc with the target environment so that external utils 3747 may easily extract it and embed it in final U-Boot images. 3748 3749- CONFIG_ENV_IS_IN_FLASH: 3750 3751 Define this if the environment is in flash memory. 3752 3753 a) The environment occupies one whole flash sector, which is 3754 "embedded" in the text segment with the U-Boot code. This 3755 happens usually with "bottom boot sector" or "top boot 3756 sector" type flash chips, which have several smaller 3757 sectors at the start or the end. For instance, such a 3758 layout can have sector sizes of 8, 2x4, 16, Nx32 kB. In 3759 such a case you would place the environment in one of the 3760 4 kB sectors - with U-Boot code before and after it. With 3761 "top boot sector" type flash chips, you would put the 3762 environment in one of the last sectors, leaving a gap 3763 between U-Boot and the environment. 3764 3765 - CONFIG_ENV_OFFSET: 3766 3767 Offset of environment data (variable area) to the 3768 beginning of flash memory; for instance, with bottom boot 3769 type flash chips the second sector can be used: the offset 3770 for this sector is given here. 3771 3772 CONFIG_ENV_OFFSET is used relative to CONFIG_SYS_FLASH_BASE. 3773 3774 - CONFIG_ENV_ADDR: 3775 3776 This is just another way to specify the start address of 3777 the flash sector containing the environment (instead of 3778 CONFIG_ENV_OFFSET). 3779 3780 - CONFIG_ENV_SECT_SIZE: 3781 3782 Size of the sector containing the environment. 3783 3784 3785 b) Sometimes flash chips have few, equal sized, BIG sectors. 3786 In such a case you don't want to spend a whole sector for 3787 the environment. 3788 3789 - CONFIG_ENV_SIZE: 3790 3791 If you use this in combination with CONFIG_ENV_IS_IN_FLASH 3792 and CONFIG_ENV_SECT_SIZE, you can specify to use only a part 3793 of this flash sector for the environment. This saves 3794 memory for the RAM copy of the environment. 3795 3796 It may also save flash memory if you decide to use this 3797 when your environment is "embedded" within U-Boot code, 3798 since then the remainder of the flash sector could be used 3799 for U-Boot code. It should be pointed out that this is 3800 STRONGLY DISCOURAGED from a robustness point of view: 3801 updating the environment in flash makes it always 3802 necessary to erase the WHOLE sector. If something goes 3803 wrong before the contents has been restored from a copy in 3804 RAM, your target system will be dead. 3805 3806 - CONFIG_ENV_ADDR_REDUND 3807 CONFIG_ENV_SIZE_REDUND 3808 3809 These settings describe a second storage area used to hold 3810 a redundant copy of the environment data, so that there is 3811 a valid backup copy in case there is a power failure during 3812 a "saveenv" operation. 3813 3814BE CAREFUL! Any changes to the flash layout, and some changes to the 3815source code will make it necessary to adapt <board>/u-boot.lds* 3816accordingly! 3817 3818 3819- CONFIG_ENV_IS_IN_NVRAM: 3820 3821 Define this if you have some non-volatile memory device 3822 (NVRAM, battery buffered SRAM) which you want to use for the 3823 environment. 3824 3825 - CONFIG_ENV_ADDR: 3826 - CONFIG_ENV_SIZE: 3827 3828 These two #defines are used to determine the memory area you 3829 want to use for environment. It is assumed that this memory 3830 can just be read and written to, without any special 3831 provision. 3832 3833BE CAREFUL! The first access to the environment happens quite early 3834in U-Boot initialization (when we try to get the setting of for the 3835console baudrate). You *MUST* have mapped your NVRAM area then, or 3836U-Boot will hang. 3837 3838Please note that even with NVRAM we still use a copy of the 3839environment in RAM: we could work on NVRAM directly, but we want to 3840keep settings there always unmodified except somebody uses "saveenv" 3841to save the current settings. 3842 3843 3844- CONFIG_ENV_IS_IN_EEPROM: 3845 3846 Use this if you have an EEPROM or similar serial access 3847 device and a driver for it. 3848 3849 - CONFIG_ENV_OFFSET: 3850 - CONFIG_ENV_SIZE: 3851 3852 These two #defines specify the offset and size of the 3853 environment area within the total memory of your EEPROM. 3854 3855 - CONFIG_SYS_I2C_EEPROM_ADDR: 3856 If defined, specified the chip address of the EEPROM device. 3857 The default address is zero. 3858 3859 - CONFIG_SYS_I2C_EEPROM_BUS: 3860 If defined, specified the i2c bus of the EEPROM device. 3861 3862 - CONFIG_SYS_EEPROM_PAGE_WRITE_BITS: 3863 If defined, the number of bits used to address bytes in a 3864 single page in the EEPROM device. A 64 byte page, for example 3865 would require six bits. 3866 3867 - CONFIG_SYS_EEPROM_PAGE_WRITE_DELAY_MS: 3868 If defined, the number of milliseconds to delay between 3869 page writes. The default is zero milliseconds. 3870 3871 - CONFIG_SYS_I2C_EEPROM_ADDR_LEN: 3872 The length in bytes of the EEPROM memory array address. Note 3873 that this is NOT the chip address length! 3874 3875 - CONFIG_SYS_I2C_EEPROM_ADDR_OVERFLOW: 3876 EEPROM chips that implement "address overflow" are ones 3877 like Catalyst 24WC04/08/16 which has 9/10/11 bits of 3878 address and the extra bits end up in the "chip address" bit 3879 slots. This makes a 24WC08 (1Kbyte) chip look like four 256 3880 byte chips. 3881 3882 Note that we consider the length of the address field to 3883 still be one byte because the extra address bits are hidden 3884 in the chip address. 3885 3886 - CONFIG_SYS_EEPROM_SIZE: 3887 The size in bytes of the EEPROM device. 3888 3889 - CONFIG_ENV_EEPROM_IS_ON_I2C 3890 define this, if you have I2C and SPI activated, and your 3891 EEPROM, which holds the environment, is on the I2C bus. 3892 3893 - CONFIG_I2C_ENV_EEPROM_BUS 3894 if you have an Environment on an EEPROM reached over 3895 I2C muxes, you can define here, how to reach this 3896 EEPROM. For example: 3897 3898 #define CONFIG_I2C_ENV_EEPROM_BUS 1 3899 3900 EEPROM which holds the environment, is reached over 3901 a pca9547 i2c mux with address 0x70, channel 3. 3902 3903- CONFIG_ENV_IS_IN_DATAFLASH: 3904 3905 Define this if you have a DataFlash memory device which you 3906 want to use for the environment. 3907 3908 - CONFIG_ENV_OFFSET: 3909 - CONFIG_ENV_ADDR: 3910 - CONFIG_ENV_SIZE: 3911 3912 These three #defines specify the offset and size of the 3913 environment area within the total memory of your DataFlash placed 3914 at the specified address. 3915 3916- CONFIG_ENV_IS_IN_SPI_FLASH: 3917 3918 Define this if you have a SPI Flash memory device which you 3919 want to use for the environment. 3920 3921 - CONFIG_ENV_OFFSET: 3922 - CONFIG_ENV_SIZE: 3923 3924 These two #defines specify the offset and size of the 3925 environment area within the SPI Flash. CONFIG_ENV_OFFSET must be 3926 aligned to an erase sector boundary. 3927 3928 - CONFIG_ENV_SECT_SIZE: 3929 3930 Define the SPI flash's sector size. 3931 3932 - CONFIG_ENV_OFFSET_REDUND (optional): 3933 3934 This setting describes a second storage area of CONFIG_ENV_SIZE 3935 size used to hold a redundant copy of the environment data, so 3936 that there is a valid backup copy in case there is a power failure 3937 during a "saveenv" operation. CONFIG_ENV_OFFSET_REDUND must be 3938 aligned to an erase sector boundary. 3939 3940 - CONFIG_ENV_SPI_BUS (optional): 3941 - CONFIG_ENV_SPI_CS (optional): 3942 3943 Define the SPI bus and chip select. If not defined they will be 0. 3944 3945 - CONFIG_ENV_SPI_MAX_HZ (optional): 3946 3947 Define the SPI max work clock. If not defined then use 1MHz. 3948 3949 - CONFIG_ENV_SPI_MODE (optional): 3950 3951 Define the SPI work mode. If not defined then use SPI_MODE_3. 3952 3953- CONFIG_ENV_IS_IN_REMOTE: 3954 3955 Define this if you have a remote memory space which you 3956 want to use for the local device's environment. 3957 3958 - CONFIG_ENV_ADDR: 3959 - CONFIG_ENV_SIZE: 3960 3961 These two #defines specify the address and size of the 3962 environment area within the remote memory space. The 3963 local device can get the environment from remote memory 3964 space by SRIO or PCIE links. 3965 3966BE CAREFUL! For some special cases, the local device can not use 3967"saveenv" command. For example, the local device will get the 3968environment stored in a remote NOR flash by SRIO or PCIE link, 3969but it can not erase, write this NOR flash by SRIO or PCIE interface. 3970 3971- CONFIG_ENV_IS_IN_NAND: 3972 3973 Define this if you have a NAND device which you want to use 3974 for the environment. 3975 3976 - CONFIG_ENV_OFFSET: 3977 - CONFIG_ENV_SIZE: 3978 3979 These two #defines specify the offset and size of the environment 3980 area within the first NAND device. CONFIG_ENV_OFFSET must be 3981 aligned to an erase block boundary. 3982 3983 - CONFIG_ENV_OFFSET_REDUND (optional): 3984 3985 This setting describes a second storage area of CONFIG_ENV_SIZE 3986 size used to hold a redundant copy of the environment data, so 3987 that there is a valid backup copy in case there is a power failure 3988 during a "saveenv" operation. CONFIG_ENV_OFFSET_REDUND must be 3989 aligned to an erase block boundary. 3990 3991 - CONFIG_ENV_RANGE (optional): 3992 3993 Specifies the length of the region in which the environment 3994 can be written. This should be a multiple of the NAND device's 3995 block size. Specifying a range with more erase blocks than 3996 are needed to hold CONFIG_ENV_SIZE allows bad blocks within 3997 the range to be avoided. 3998 3999 - CONFIG_ENV_OFFSET_OOB (optional): 4000 4001 Enables support for dynamically retrieving the offset of the 4002 environment from block zero's out-of-band data. The 4003 "nand env.oob" command can be used to record this offset. 4004 Currently, CONFIG_ENV_OFFSET_REDUND is not supported when 4005 using CONFIG_ENV_OFFSET_OOB. 4006 4007- CONFIG_NAND_ENV_DST 4008 4009 Defines address in RAM to which the nand_spl code should copy the 4010 environment. If redundant environment is used, it will be copied to 4011 CONFIG_NAND_ENV_DST + CONFIG_ENV_SIZE. 4012 4013- CONFIG_ENV_IS_IN_UBI: 4014 4015 Define this if you have an UBI volume that you want to use for the 4016 environment. This has the benefit of wear-leveling the environment 4017 accesses, which is important on NAND. 4018 4019 - CONFIG_ENV_UBI_PART: 4020 4021 Define this to a string that is the mtd partition containing the UBI. 4022 4023 - CONFIG_ENV_UBI_VOLUME: 4024 4025 Define this to the name of the volume that you want to store the 4026 environment in. 4027 4028 - CONFIG_ENV_UBI_VOLUME_REDUND: 4029 4030 Define this to the name of another volume to store a second copy of 4031 the environment in. This will enable redundant environments in UBI. 4032 It is assumed that both volumes are in the same MTD partition. 4033 4034 - CONFIG_UBI_SILENCE_MSG 4035 - CONFIG_UBIFS_SILENCE_MSG 4036 4037 You will probably want to define these to avoid a really noisy system 4038 when storing the env in UBI. 4039 4040- CONFIG_ENV_IS_IN_FAT: 4041 Define this if you want to use the FAT file system for the environment. 4042 4043 - FAT_ENV_INTERFACE: 4044 4045 Define this to a string that is the name of the block device. 4046 4047 - FAT_ENV_DEVICE_AND_PART: 4048 4049 Define this to a string to specify the partition of the device. It can 4050 be as following: 4051 4052 "D:P", "D:0", "D", "D:" or "D:auto" (D, P are integers. And P >= 1) 4053 - "D:P": device D partition P. Error occurs if device D has no 4054 partition table. 4055 - "D:0": device D. 4056 - "D" or "D:": device D partition 1 if device D has partition 4057 table, or the whole device D if has no partition 4058 table. 4059 - "D:auto": first partition in device D with bootable flag set. 4060 If none, first valid partition in device D. If no 4061 partition table then means device D. 4062 4063 - FAT_ENV_FILE: 4064 4065 It's a string of the FAT file name. This file use to store the 4066 environment. 4067 4068 - CONFIG_FAT_WRITE: 4069 This should be defined. Otherwise it cannot save the environment file. 4070 4071- CONFIG_ENV_IS_IN_MMC: 4072 4073 Define this if you have an MMC device which you want to use for the 4074 environment. 4075 4076 - CONFIG_SYS_MMC_ENV_DEV: 4077 4078 Specifies which MMC device the environment is stored in. 4079 4080 - CONFIG_SYS_MMC_ENV_PART (optional): 4081 4082 Specifies which MMC partition the environment is stored in. If not 4083 set, defaults to partition 0, the user area. Common values might be 4084 1 (first MMC boot partition), 2 (second MMC boot partition). 4085 4086 - CONFIG_ENV_OFFSET: 4087 - CONFIG_ENV_SIZE: 4088 4089 These two #defines specify the offset and size of the environment 4090 area within the specified MMC device. 4091 4092 If offset is positive (the usual case), it is treated as relative to 4093 the start of the MMC partition. If offset is negative, it is treated 4094 as relative to the end of the MMC partition. This can be useful if 4095 your board may be fitted with different MMC devices, which have 4096 different sizes for the MMC partitions, and you always want the 4097 environment placed at the very end of the partition, to leave the 4098 maximum possible space before it, to store other data. 4099 4100 These two values are in units of bytes, but must be aligned to an 4101 MMC sector boundary. 4102 4103 - CONFIG_ENV_OFFSET_REDUND (optional): 4104 4105 Specifies a second storage area, of CONFIG_ENV_SIZE size, used to 4106 hold a redundant copy of the environment data. This provides a 4107 valid backup copy in case the other copy is corrupted, e.g. due 4108 to a power failure during a "saveenv" operation. 4109 4110 This value may also be positive or negative; this is handled in the 4111 same way as CONFIG_ENV_OFFSET. 4112 4113 This value is also in units of bytes, but must also be aligned to 4114 an MMC sector boundary. 4115 4116 - CONFIG_ENV_SIZE_REDUND (optional): 4117 4118 This value need not be set, even when CONFIG_ENV_OFFSET_REDUND is 4119 set. If this value is set, it must be set to the same value as 4120 CONFIG_ENV_SIZE. 4121 4122- CONFIG_SYS_SPI_INIT_OFFSET 4123 4124 Defines offset to the initial SPI buffer area in DPRAM. The 4125 area is used at an early stage (ROM part) if the environment 4126 is configured to reside in the SPI EEPROM: We need a 520 byte 4127 scratch DPRAM area. It is used between the two initialization 4128 calls (spi_init_f() and spi_init_r()). A value of 0xB00 seems 4129 to be a good choice since it makes it far enough from the 4130 start of the data area as well as from the stack pointer. 4131 4132Please note that the environment is read-only until the monitor 4133has been relocated to RAM and a RAM copy of the environment has been 4134created; also, when using EEPROM you will have to use getenv_f() 4135until then to read environment variables. 4136 4137The environment is protected by a CRC32 checksum. Before the monitor 4138is relocated into RAM, as a result of a bad CRC you will be working 4139with the compiled-in default environment - *silently*!!! [This is 4140necessary, because the first environment variable we need is the 4141"baudrate" setting for the console - if we have a bad CRC, we don't 4142have any device yet where we could complain.] 4143 4144Note: once the monitor has been relocated, then it will complain if 4145the default environment is used; a new CRC is computed as soon as you 4146use the "saveenv" command to store a valid environment. 4147 4148- CONFIG_SYS_FAULT_ECHO_LINK_DOWN: 4149 Echo the inverted Ethernet link state to the fault LED. 4150 4151 Note: If this option is active, then CONFIG_SYS_FAULT_MII_ADDR 4152 also needs to be defined. 4153 4154- CONFIG_SYS_FAULT_MII_ADDR: 4155 MII address of the PHY to check for the Ethernet link state. 4156 4157- CONFIG_NS16550_MIN_FUNCTIONS: 4158 Define this if you desire to only have use of the NS16550_init 4159 and NS16550_putc functions for the serial driver located at 4160 drivers/serial/ns16550.c. This option is useful for saving 4161 space for already greatly restricted images, including but not 4162 limited to NAND_SPL configurations. 4163 4164- CONFIG_DISPLAY_BOARDINFO 4165 Display information about the board that U-Boot is running on 4166 when U-Boot starts up. The board function checkboard() is called 4167 to do this. 4168 4169- CONFIG_DISPLAY_BOARDINFO_LATE 4170 Similar to the previous option, but display this information 4171 later, once stdio is running and output goes to the LCD, if 4172 present. 4173 4174- CONFIG_BOARD_SIZE_LIMIT: 4175 Maximum size of the U-Boot image. When defined, the 4176 build system checks that the actual size does not 4177 exceed it. 4178 4179Low Level (hardware related) configuration options: 4180--------------------------------------------------- 4181 4182- CONFIG_SYS_CACHELINE_SIZE: 4183 Cache Line Size of the CPU. 4184 4185- CONFIG_SYS_DEFAULT_IMMR: 4186 Default address of the IMMR after system reset. 4187 4188 Needed on some 8260 systems (MPC8260ADS, PQ2FADS-ZU, 4189 and RPXsuper) to be able to adjust the position of 4190 the IMMR register after a reset. 4191 4192- CONFIG_SYS_CCSRBAR_DEFAULT: 4193 Default (power-on reset) physical address of CCSR on Freescale 4194 PowerPC SOCs. 4195 4196- CONFIG_SYS_CCSRBAR: 4197 Virtual address of CCSR. On a 32-bit build, this is typically 4198 the same value as CONFIG_SYS_CCSRBAR_DEFAULT. 4199 4200 CONFIG_SYS_DEFAULT_IMMR must also be set to this value, 4201 for cross-platform code that uses that macro instead. 4202 4203- CONFIG_SYS_CCSRBAR_PHYS: 4204 Physical address of CCSR. CCSR can be relocated to a new 4205 physical address, if desired. In this case, this macro should 4206 be set to that address. Otherwise, it should be set to the 4207 same value as CONFIG_SYS_CCSRBAR_DEFAULT. For example, CCSR 4208 is typically relocated on 36-bit builds. It is recommended 4209 that this macro be defined via the _HIGH and _LOW macros: 4210 4211 #define CONFIG_SYS_CCSRBAR_PHYS ((CONFIG_SYS_CCSRBAR_PHYS_HIGH 4212 * 1ull) << 32 | CONFIG_SYS_CCSRBAR_PHYS_LOW) 4213 4214- CONFIG_SYS_CCSRBAR_PHYS_HIGH: 4215 Bits 33-36 of CONFIG_SYS_CCSRBAR_PHYS. This value is typically 4216 either 0 (32-bit build) or 0xF (36-bit build). This macro is 4217 used in assembly code, so it must not contain typecasts or 4218 integer size suffixes (e.g. "ULL"). 4219 4220- CONFIG_SYS_CCSRBAR_PHYS_LOW: 4221 Lower 32-bits of CONFIG_SYS_CCSRBAR_PHYS. This macro is 4222 used in assembly code, so it must not contain typecasts or 4223 integer size suffixes (e.g. "ULL"). 4224 4225- CONFIG_SYS_CCSR_DO_NOT_RELOCATE: 4226 If this macro is defined, then CONFIG_SYS_CCSRBAR_PHYS will be 4227 forced to a value that ensures that CCSR is not relocated. 4228 4229- Floppy Disk Support: 4230 CONFIG_SYS_FDC_DRIVE_NUMBER 4231 4232 the default drive number (default value 0) 4233 4234 CONFIG_SYS_ISA_IO_STRIDE 4235 4236 defines the spacing between FDC chipset registers 4237 (default value 1) 4238 4239 CONFIG_SYS_ISA_IO_OFFSET 4240 4241 defines the offset of register from address. It 4242 depends on which part of the data bus is connected to 4243 the FDC chipset. (default value 0) 4244 4245 If CONFIG_SYS_ISA_IO_STRIDE CONFIG_SYS_ISA_IO_OFFSET and 4246 CONFIG_SYS_FDC_DRIVE_NUMBER are undefined, they take their 4247 default value. 4248 4249 if CONFIG_SYS_FDC_HW_INIT is defined, then the function 4250 fdc_hw_init() is called at the beginning of the FDC 4251 setup. fdc_hw_init() must be provided by the board 4252 source code. It is used to make hardware-dependent 4253 initializations. 4254 4255- CONFIG_IDE_AHB: 4256 Most IDE controllers were designed to be connected with PCI 4257 interface. Only few of them were designed for AHB interface. 4258 When software is doing ATA command and data transfer to 4259 IDE devices through IDE-AHB controller, some additional 4260 registers accessing to these kind of IDE-AHB controller 4261 is required. 4262 4263- CONFIG_SYS_IMMR: Physical address of the Internal Memory. 4264 DO NOT CHANGE unless you know exactly what you're 4265 doing! (11-4) [MPC8xx/82xx systems only] 4266 4267- CONFIG_SYS_INIT_RAM_ADDR: 4268 4269 Start address of memory area that can be used for 4270 initial data and stack; please note that this must be 4271 writable memory that is working WITHOUT special 4272 initialization, i. e. you CANNOT use normal RAM which 4273 will become available only after programming the 4274 memory controller and running certain initialization 4275 sequences. 4276 4277 U-Boot uses the following memory types: 4278 - MPC8xx and MPC8260: IMMR (internal memory of the CPU) 4279 - MPC824X: data cache 4280 - PPC4xx: data cache 4281 4282- CONFIG_SYS_GBL_DATA_OFFSET: 4283 4284 Offset of the initial data structure in the memory 4285 area defined by CONFIG_SYS_INIT_RAM_ADDR. Usually 4286 CONFIG_SYS_GBL_DATA_OFFSET is chosen such that the initial 4287 data is located at the end of the available space 4288 (sometimes written as (CONFIG_SYS_INIT_RAM_SIZE - 4289 GENERATED_GBL_DATA_SIZE), and the initial stack is just 4290 below that area (growing from (CONFIG_SYS_INIT_RAM_ADDR + 4291 CONFIG_SYS_GBL_DATA_OFFSET) downward. 4292 4293 Note: 4294 On the MPC824X (or other systems that use the data 4295 cache for initial memory) the address chosen for 4296 CONFIG_SYS_INIT_RAM_ADDR is basically arbitrary - it must 4297 point to an otherwise UNUSED address space between 4298 the top of RAM and the start of the PCI space. 4299 4300- CONFIG_SYS_SIUMCR: SIU Module Configuration (11-6) 4301 4302- CONFIG_SYS_SYPCR: System Protection Control (11-9) 4303 4304- CONFIG_SYS_TBSCR: Time Base Status and Control (11-26) 4305 4306- CONFIG_SYS_PISCR: Periodic Interrupt Status and Control (11-31) 4307 4308- CONFIG_SYS_PLPRCR: PLL, Low-Power, and Reset Control Register (15-30) 4309 4310- CONFIG_SYS_SCCR: System Clock and reset Control Register (15-27) 4311 4312- CONFIG_SYS_OR_TIMING_SDRAM: 4313 SDRAM timing 4314 4315- CONFIG_SYS_MAMR_PTA: 4316 periodic timer for refresh 4317 4318- CONFIG_SYS_DER: Debug Event Register (37-47) 4319 4320- FLASH_BASE0_PRELIM, FLASH_BASE1_PRELIM, CONFIG_SYS_REMAP_OR_AM, 4321 CONFIG_SYS_PRELIM_OR_AM, CONFIG_SYS_OR_TIMING_FLASH, CONFIG_SYS_OR0_REMAP, 4322 CONFIG_SYS_OR0_PRELIM, CONFIG_SYS_BR0_PRELIM, CONFIG_SYS_OR1_REMAP, CONFIG_SYS_OR1_PRELIM, 4323 CONFIG_SYS_BR1_PRELIM: 4324 Memory Controller Definitions: BR0/1 and OR0/1 (FLASH) 4325 4326- SDRAM_BASE2_PRELIM, SDRAM_BASE3_PRELIM, SDRAM_MAX_SIZE, 4327 CONFIG_SYS_OR_TIMING_SDRAM, CONFIG_SYS_OR2_PRELIM, CONFIG_SYS_BR2_PRELIM, 4328 CONFIG_SYS_OR3_PRELIM, CONFIG_SYS_BR3_PRELIM: 4329 Memory Controller Definitions: BR2/3 and OR2/3 (SDRAM) 4330 4331- CONFIG_SYS_MAMR_PTA, CONFIG_SYS_MPTPR_2BK_4K, CONFIG_SYS_MPTPR_1BK_4K, CONFIG_SYS_MPTPR_2BK_8K, 4332 CONFIG_SYS_MPTPR_1BK_8K, CONFIG_SYS_MAMR_8COL, CONFIG_SYS_MAMR_9COL: 4333 Machine Mode Register and Memory Periodic Timer 4334 Prescaler definitions (SDRAM timing) 4335 4336- CONFIG_SYS_I2C_UCODE_PATCH, CONFIG_SYS_I2C_DPMEM_OFFSET [0x1FC0]: 4337 enable I2C microcode relocation patch (MPC8xx); 4338 define relocation offset in DPRAM [DSP2] 4339 4340- CONFIG_SYS_SMC_UCODE_PATCH, CONFIG_SYS_SMC_DPMEM_OFFSET [0x1FC0]: 4341 enable SMC microcode relocation patch (MPC8xx); 4342 define relocation offset in DPRAM [SMC1] 4343 4344- CONFIG_SYS_SPI_UCODE_PATCH, CONFIG_SYS_SPI_DPMEM_OFFSET [0x1FC0]: 4345 enable SPI microcode relocation patch (MPC8xx); 4346 define relocation offset in DPRAM [SCC4] 4347 4348- CONFIG_SYS_CPM_POST_WORD_ADDR: (MPC8xx, MPC8260 only) 4349 Offset of the bootmode word in DPRAM used by post 4350 (Power On Self Tests). This definition overrides 4351 #define'd default value in commproc.h resp. 4352 cpm_8260.h. 4353 4354- CONFIG_SYS_PCI_SLV_MEM_LOCAL, CONFIG_SYS_PCI_SLV_MEM_BUS, CONFIG_SYS_PICMR0_MASK_ATTRIB, 4355 CONFIG_SYS_PCI_MSTR0_LOCAL, CONFIG_SYS_PCIMSK0_MASK, CONFIG_SYS_PCI_MSTR1_LOCAL, 4356 CONFIG_SYS_PCIMSK1_MASK, CONFIG_SYS_PCI_MSTR_MEM_LOCAL, CONFIG_SYS_PCI_MSTR_MEM_BUS, 4357 CONFIG_SYS_CPU_PCI_MEM_START, CONFIG_SYS_PCI_MSTR_MEM_SIZE, CONFIG_SYS_POCMR0_MASK_ATTRIB, 4358 CONFIG_SYS_PCI_MSTR_MEMIO_LOCAL, CONFIG_SYS_PCI_MSTR_MEMIO_BUS, CPU_PCI_MEMIO_START, 4359 CONFIG_SYS_PCI_MSTR_MEMIO_SIZE, CONFIG_SYS_POCMR1_MASK_ATTRIB, CONFIG_SYS_PCI_MSTR_IO_LOCAL, 4360 CONFIG_SYS_PCI_MSTR_IO_BUS, CONFIG_SYS_CPU_PCI_IO_START, CONFIG_SYS_PCI_MSTR_IO_SIZE, 4361 CONFIG_SYS_POCMR2_MASK_ATTRIB: (MPC826x only) 4362 Overrides the default PCI memory map in arch/powerpc/cpu/mpc8260/pci.c if set. 4363 4364- CONFIG_PCI_DISABLE_PCIE: 4365 Disable PCI-Express on systems where it is supported but not 4366 required. 4367 4368- CONFIG_PCI_ENUM_ONLY 4369 Only scan through and get the devices on the buses. 4370 Don't do any setup work, presumably because someone or 4371 something has already done it, and we don't need to do it 4372 a second time. Useful for platforms that are pre-booted 4373 by coreboot or similar. 4374 4375- CONFIG_PCI_INDIRECT_BRIDGE: 4376 Enable support for indirect PCI bridges. 4377 4378- CONFIG_SYS_SRIO: 4379 Chip has SRIO or not 4380 4381- CONFIG_SRIO1: 4382 Board has SRIO 1 port available 4383 4384- CONFIG_SRIO2: 4385 Board has SRIO 2 port available 4386 4387- CONFIG_SRIO_PCIE_BOOT_MASTER 4388 Board can support master function for Boot from SRIO and PCIE 4389 4390- CONFIG_SYS_SRIOn_MEM_VIRT: 4391 Virtual Address of SRIO port 'n' memory region 4392 4393- CONFIG_SYS_SRIOn_MEM_PHYS: 4394 Physical Address of SRIO port 'n' memory region 4395 4396- CONFIG_SYS_SRIOn_MEM_SIZE: 4397 Size of SRIO port 'n' memory region 4398 4399- CONFIG_SYS_NAND_BUSWIDTH_16BIT 4400 Defined to tell the NAND controller that the NAND chip is using 4401 a 16 bit bus. 4402 Not all NAND drivers use this symbol. 4403 Example of drivers that use it: 4404 - drivers/mtd/nand/ndfc.c 4405 - drivers/mtd/nand/mxc_nand.c 4406 4407- CONFIG_SYS_NDFC_EBC0_CFG 4408 Sets the EBC0_CFG register for the NDFC. If not defined 4409 a default value will be used. 4410 4411- CONFIG_SPD_EEPROM 4412 Get DDR timing information from an I2C EEPROM. Common 4413 with pluggable memory modules such as SODIMMs 4414 4415 SPD_EEPROM_ADDRESS 4416 I2C address of the SPD EEPROM 4417 4418- CONFIG_SYS_SPD_BUS_NUM 4419 If SPD EEPROM is on an I2C bus other than the first 4420 one, specify here. Note that the value must resolve 4421 to something your driver can deal with. 4422 4423- CONFIG_SYS_DDR_RAW_TIMING 4424 Get DDR timing information from other than SPD. Common with 4425 soldered DDR chips onboard without SPD. DDR raw timing 4426 parameters are extracted from datasheet and hard-coded into 4427 header files or board specific files. 4428 4429- CONFIG_FSL_DDR_INTERACTIVE 4430 Enable interactive DDR debugging. See doc/README.fsl-ddr. 4431 4432- CONFIG_FSL_DDR_SYNC_REFRESH 4433 Enable sync of refresh for multiple controllers. 4434 4435- CONFIG_FSL_DDR_BIST 4436 Enable built-in memory test for Freescale DDR controllers. 4437 4438- CONFIG_SYS_83XX_DDR_USES_CS0 4439 Only for 83xx systems. If specified, then DDR should 4440 be configured using CS0 and CS1 instead of CS2 and CS3. 4441 4442- CONFIG_ETHER_ON_FEC[12] 4443 Define to enable FEC[12] on a 8xx series processor. 4444 4445- CONFIG_FEC[12]_PHY 4446 Define to the hardcoded PHY address which corresponds 4447 to the given FEC; i. e. 4448 #define CONFIG_FEC1_PHY 4 4449 means that the PHY with address 4 is connected to FEC1 4450 4451 When set to -1, means to probe for first available. 4452 4453- CONFIG_FEC[12]_PHY_NORXERR 4454 The PHY does not have a RXERR line (RMII only). 4455 (so program the FEC to ignore it). 4456 4457- CONFIG_RMII 4458 Enable RMII mode for all FECs. 4459 Note that this is a global option, we can't 4460 have one FEC in standard MII mode and another in RMII mode. 4461 4462- CONFIG_CRC32_VERIFY 4463 Add a verify option to the crc32 command. 4464 The syntax is: 4465 4466 => crc32 -v <address> <count> <crc32> 4467 4468 Where address/count indicate a memory area 4469 and crc32 is the correct crc32 which the 4470 area should have. 4471 4472- CONFIG_LOOPW 4473 Add the "loopw" memory command. This only takes effect if 4474 the memory commands are activated globally (CONFIG_CMD_MEM). 4475 4476- CONFIG_MX_CYCLIC 4477 Add the "mdc" and "mwc" memory commands. These are cyclic 4478 "md/mw" commands. 4479 Examples: 4480 4481 => mdc.b 10 4 500 4482 This command will print 4 bytes (10,11,12,13) each 500 ms. 4483 4484 => mwc.l 100 12345678 10 4485 This command will write 12345678 to address 100 all 10 ms. 4486 4487 This only takes effect if the memory commands are activated 4488 globally (CONFIG_CMD_MEM). 4489 4490- CONFIG_SKIP_LOWLEVEL_INIT 4491 [ARM, NDS32, MIPS only] If this variable is defined, then certain 4492 low level initializations (like setting up the memory 4493 controller) are omitted and/or U-Boot does not 4494 relocate itself into RAM. 4495 4496 Normally this variable MUST NOT be defined. The only 4497 exception is when U-Boot is loaded (to RAM) by some 4498 other boot loader or by a debugger which performs 4499 these initializations itself. 4500 4501- CONFIG_SKIP_LOWLEVEL_INIT_ONLY 4502 [ARM926EJ-S only] This allows just the call to lowlevel_init() 4503 to be skipped. The normal CP15 init (such as enabling the 4504 instruction cache) is still performed. 4505 4506- CONFIG_SPL_BUILD 4507 Modifies the behaviour of start.S when compiling a loader 4508 that is executed before the actual U-Boot. E.g. when 4509 compiling a NAND SPL. 4510 4511- CONFIG_TPL_BUILD 4512 Modifies the behaviour of start.S when compiling a loader 4513 that is executed after the SPL and before the actual U-Boot. 4514 It is loaded by the SPL. 4515 4516- CONFIG_SYS_MPC85XX_NO_RESETVEC 4517 Only for 85xx systems. If this variable is specified, the section 4518 .resetvec is not kept and the section .bootpg is placed in the 4519 previous 4k of the .text section. 4520 4521- CONFIG_ARCH_MAP_SYSMEM 4522 Generally U-Boot (and in particular the md command) uses 4523 effective address. It is therefore not necessary to regard 4524 U-Boot address as virtual addresses that need to be translated 4525 to physical addresses. However, sandbox requires this, since 4526 it maintains its own little RAM buffer which contains all 4527 addressable memory. This option causes some memory accesses 4528 to be mapped through map_sysmem() / unmap_sysmem(). 4529 4530- CONFIG_X86_RESET_VECTOR 4531 If defined, the x86 reset vector code is included. This is not 4532 needed when U-Boot is running from Coreboot. 4533 4534- CONFIG_SYS_MPUCLK 4535 Defines the MPU clock speed (in MHz). 4536 4537 NOTE : currently only supported on AM335x platforms. 4538 4539- CONFIG_SPL_AM33XX_ENABLE_RTC32K_OSC: 4540 Enables the RTC32K OSC on AM33xx based plattforms 4541 4542- CONFIG_SYS_NAND_NO_SUBPAGE_WRITE 4543 Option to disable subpage write in NAND driver 4544 driver that uses this: 4545 drivers/mtd/nand/davinci_nand.c 4546 4547Freescale QE/FMAN Firmware Support: 4548----------------------------------- 4549 4550The Freescale QUICCEngine (QE) and Frame Manager (FMAN) both support the 4551loading of "firmware", which is encoded in the QE firmware binary format. 4552This firmware often needs to be loaded during U-Boot booting, so macros 4553are used to identify the storage device (NOR flash, SPI, etc) and the address 4554within that device. 4555 4556- CONFIG_SYS_FMAN_FW_ADDR 4557 The address in the storage device where the FMAN microcode is located. The 4558 meaning of this address depends on which CONFIG_SYS_QE_FW_IN_xxx macro 4559 is also specified. 4560 4561- CONFIG_SYS_QE_FW_ADDR 4562 The address in the storage device where the QE microcode is located. The 4563 meaning of this address depends on which CONFIG_SYS_QE_FW_IN_xxx macro 4564 is also specified. 4565 4566- CONFIG_SYS_QE_FMAN_FW_LENGTH 4567 The maximum possible size of the firmware. The firmware binary format 4568 has a field that specifies the actual size of the firmware, but it 4569 might not be possible to read any part of the firmware unless some 4570 local storage is allocated to hold the entire firmware first. 4571 4572- CONFIG_SYS_QE_FMAN_FW_IN_NOR 4573 Specifies that QE/FMAN firmware is located in NOR flash, mapped as 4574 normal addressable memory via the LBC. CONFIG_SYS_FMAN_FW_ADDR is the 4575 virtual address in NOR flash. 4576 4577- CONFIG_SYS_QE_FMAN_FW_IN_NAND 4578 Specifies that QE/FMAN firmware is located in NAND flash. 4579 CONFIG_SYS_FMAN_FW_ADDR is the offset within NAND flash. 4580 4581- CONFIG_SYS_QE_FMAN_FW_IN_MMC 4582 Specifies that QE/FMAN firmware is located on the primary SD/MMC 4583 device. CONFIG_SYS_FMAN_FW_ADDR is the byte offset on that device. 4584 4585- CONFIG_SYS_QE_FMAN_FW_IN_REMOTE 4586 Specifies that QE/FMAN firmware is located in the remote (master) 4587 memory space. CONFIG_SYS_FMAN_FW_ADDR is a virtual address which 4588 can be mapped from slave TLB->slave LAW->slave SRIO or PCIE outbound 4589 window->master inbound window->master LAW->the ucode address in 4590 master's memory space. 4591 4592Freescale Layerscape Management Complex Firmware Support: 4593--------------------------------------------------------- 4594The Freescale Layerscape Management Complex (MC) supports the loading of 4595"firmware". 4596This firmware often needs to be loaded during U-Boot booting, so macros 4597are used to identify the storage device (NOR flash, SPI, etc) and the address 4598within that device. 4599 4600- CONFIG_FSL_MC_ENET 4601 Enable the MC driver for Layerscape SoCs. 4602 4603Freescale Layerscape Debug Server Support: 4604------------------------------------------- 4605The Freescale Layerscape Debug Server Support supports the loading of 4606"Debug Server firmware" and triggering SP boot-rom. 4607This firmware often needs to be loaded during U-Boot booting. 4608 4609- CONFIG_SYS_MC_RSV_MEM_ALIGN 4610 Define alignment of reserved memory MC requires 4611 4612Reproducible builds 4613------------------- 4614 4615In order to achieve reproducible builds, timestamps used in the U-Boot build 4616process have to be set to a fixed value. 4617 4618This is done using the SOURCE_DATE_EPOCH environment variable. 4619SOURCE_DATE_EPOCH is to be set on the build host's shell, not as a configuration 4620option for U-Boot or an environment variable in U-Boot. 4621 4622SOURCE_DATE_EPOCH should be set to a number of seconds since the epoch, in UTC. 4623 4624Building the Software: 4625====================== 4626 4627Building U-Boot has been tested in several native build environments 4628and in many different cross environments. Of course we cannot support 4629all possibly existing versions of cross development tools in all 4630(potentially obsolete) versions. In case of tool chain problems we 4631recommend to use the ELDK (see http://www.denx.de/wiki/DULG/ELDK) 4632which is extensively used to build and test U-Boot. 4633 4634If you are not using a native environment, it is assumed that you 4635have GNU cross compiling tools available in your path. In this case, 4636you must set the environment variable CROSS_COMPILE in your shell. 4637Note that no changes to the Makefile or any other source files are 4638necessary. For example using the ELDK on a 4xx CPU, please enter: 4639 4640 $ CROSS_COMPILE=ppc_4xx- 4641 $ export CROSS_COMPILE 4642 4643Note: If you wish to generate Windows versions of the utilities in 4644 the tools directory you can use the MinGW toolchain 4645 (http://www.mingw.org). Set your HOST tools to the MinGW 4646 toolchain and execute 'make tools'. For example: 4647 4648 $ make HOSTCC=i586-mingw32msvc-gcc HOSTSTRIP=i586-mingw32msvc-strip tools 4649 4650 Binaries such as tools/mkimage.exe will be created which can 4651 be executed on computers running Windows. 4652 4653U-Boot is intended to be simple to build. After installing the 4654sources you must configure U-Boot for one specific board type. This 4655is done by typing: 4656 4657 make NAME_defconfig 4658 4659where "NAME_defconfig" is the name of one of the existing configu- 4660rations; see boards.cfg for supported names. 4661 4662Note: for some board special configuration names may exist; check if 4663 additional information is available from the board vendor; for 4664 instance, the TQM823L systems are available without (standard) 4665 or with LCD support. You can select such additional "features" 4666 when choosing the configuration, i. e. 4667 4668 make TQM823L_defconfig 4669 - will configure for a plain TQM823L, i. e. no LCD support 4670 4671 make TQM823L_LCD_defconfig 4672 - will configure for a TQM823L with U-Boot console on LCD 4673 4674 etc. 4675 4676 4677Finally, type "make all", and you should get some working U-Boot 4678images ready for download to / installation on your system: 4679 4680- "u-boot.bin" is a raw binary image 4681- "u-boot" is an image in ELF binary format 4682- "u-boot.srec" is in Motorola S-Record format 4683 4684By default the build is performed locally and the objects are saved 4685in the source directory. One of the two methods can be used to change 4686this behavior and build U-Boot to some external directory: 4687 46881. Add O= to the make command line invocations: 4689 4690 make O=/tmp/build distclean 4691 make O=/tmp/build NAME_defconfig 4692 make O=/tmp/build all 4693 46942. Set environment variable KBUILD_OUTPUT to point to the desired location: 4695 4696 export KBUILD_OUTPUT=/tmp/build 4697 make distclean 4698 make NAME_defconfig 4699 make all 4700 4701Note that the command line "O=" setting overrides the KBUILD_OUTPUT environment 4702variable. 4703 4704 4705Please be aware that the Makefiles assume you are using GNU make, so 4706for instance on NetBSD you might need to use "gmake" instead of 4707native "make". 4708 4709 4710If the system board that you have is not listed, then you will need 4711to port U-Boot to your hardware platform. To do this, follow these 4712steps: 4713 47141. Create a new directory to hold your board specific code. Add any 4715 files you need. In your board directory, you will need at least 4716 the "Makefile" and a "<board>.c". 47172. Create a new configuration file "include/configs/<board>.h" for 4718 your board. 47193. If you're porting U-Boot to a new CPU, then also create a new 4720 directory to hold your CPU specific code. Add any files you need. 47214. Run "make <board>_defconfig" with your new name. 47225. Type "make", and you should get a working "u-boot.srec" file 4723 to be installed on your target system. 47246. Debug and solve any problems that might arise. 4725 [Of course, this last step is much harder than it sounds.] 4726 4727 4728Testing of U-Boot Modifications, Ports to New Hardware, etc.: 4729============================================================== 4730 4731If you have modified U-Boot sources (for instance added a new board 4732or support for new devices, a new CPU, etc.) you are expected to 4733provide feedback to the other developers. The feedback normally takes 4734the form of a "patch", i. e. a context diff against a certain (latest 4735official or latest in the git repository) version of U-Boot sources. 4736 4737But before you submit such a patch, please verify that your modifi- 4738cation did not break existing code. At least make sure that *ALL* of 4739the supported boards compile WITHOUT ANY compiler warnings. To do so, 4740just run the buildman script (tools/buildman/buildman), which will 4741configure and build U-Boot for ALL supported system. Be warned, this 4742will take a while. Please see the buildman README, or run 'buildman -H' 4743for documentation. 4744 4745 4746See also "U-Boot Porting Guide" below. 4747 4748 4749Monitor Commands - Overview: 4750============================ 4751 4752go - start application at address 'addr' 4753run - run commands in an environment variable 4754bootm - boot application image from memory 4755bootp - boot image via network using BootP/TFTP protocol 4756bootz - boot zImage from memory 4757tftpboot- boot image via network using TFTP protocol 4758 and env variables "ipaddr" and "serverip" 4759 (and eventually "gatewayip") 4760tftpput - upload a file via network using TFTP protocol 4761rarpboot- boot image via network using RARP/TFTP protocol 4762diskboot- boot from IDE devicebootd - boot default, i.e., run 'bootcmd' 4763loads - load S-Record file over serial line 4764loadb - load binary file over serial line (kermit mode) 4765md - memory display 4766mm - memory modify (auto-incrementing) 4767nm - memory modify (constant address) 4768mw - memory write (fill) 4769cp - memory copy 4770cmp - memory compare 4771crc32 - checksum calculation 4772i2c - I2C sub-system 4773sspi - SPI utility commands 4774base - print or set address offset 4775printenv- print environment variables 4776setenv - set environment variables 4777saveenv - save environment variables to persistent storage 4778protect - enable or disable FLASH write protection 4779erase - erase FLASH memory 4780flinfo - print FLASH memory information 4781nand - NAND memory operations (see doc/README.nand) 4782bdinfo - print Board Info structure 4783iminfo - print header information for application image 4784coninfo - print console devices and informations 4785ide - IDE sub-system 4786loop - infinite loop on address range 4787loopw - infinite write loop on address range 4788mtest - simple RAM test 4789icache - enable or disable instruction cache 4790dcache - enable or disable data cache 4791reset - Perform RESET of the CPU 4792echo - echo args to console 4793version - print monitor version 4794help - print online help 4795? - alias for 'help' 4796 4797 4798Monitor Commands - Detailed Description: 4799======================================== 4800 4801TODO. 4802 4803For now: just type "help <command>". 4804 4805 4806Environment Variables: 4807====================== 4808 4809U-Boot supports user configuration using Environment Variables which 4810can be made persistent by saving to Flash memory. 4811 4812Environment Variables are set using "setenv", printed using 4813"printenv", and saved to Flash using "saveenv". Using "setenv" 4814without a value can be used to delete a variable from the 4815environment. As long as you don't save the environment you are 4816working with an in-memory copy. In case the Flash area containing the 4817environment is erased by accident, a default environment is provided. 4818 4819Some configuration options can be set using Environment Variables. 4820 4821List of environment variables (most likely not complete): 4822 4823 baudrate - see CONFIG_BAUDRATE 4824 4825 bootdelay - see CONFIG_BOOTDELAY 4826 4827 bootcmd - see CONFIG_BOOTCOMMAND 4828 4829 bootargs - Boot arguments when booting an RTOS image 4830 4831 bootfile - Name of the image to load with TFTP 4832 4833 bootm_low - Memory range available for image processing in the bootm 4834 command can be restricted. This variable is given as 4835 a hexadecimal number and defines lowest address allowed 4836 for use by the bootm command. See also "bootm_size" 4837 environment variable. Address defined by "bootm_low" is 4838 also the base of the initial memory mapping for the Linux 4839 kernel -- see the description of CONFIG_SYS_BOOTMAPSZ and 4840 bootm_mapsize. 4841 4842 bootm_mapsize - Size of the initial memory mapping for the Linux kernel. 4843 This variable is given as a hexadecimal number and it 4844 defines the size of the memory region starting at base 4845 address bootm_low that is accessible by the Linux kernel 4846 during early boot. If unset, CONFIG_SYS_BOOTMAPSZ is used 4847 as the default value if it is defined, and bootm_size is 4848 used otherwise. 4849 4850 bootm_size - Memory range available for image processing in the bootm 4851 command can be restricted. This variable is given as 4852 a hexadecimal number and defines the size of the region 4853 allowed for use by the bootm command. See also "bootm_low" 4854 environment variable. 4855 4856 updatefile - Location of the software update file on a TFTP server, used 4857 by the automatic software update feature. Please refer to 4858 documentation in doc/README.update for more details. 4859 4860 autoload - if set to "no" (any string beginning with 'n'), 4861 "bootp" will just load perform a lookup of the 4862 configuration from the BOOTP server, but not try to 4863 load any image using TFTP 4864 4865 autostart - if set to "yes", an image loaded using the "bootp", 4866 "rarpboot", "tftpboot" or "diskboot" commands will 4867 be automatically started (by internally calling 4868 "bootm") 4869 4870 If set to "no", a standalone image passed to the 4871 "bootm" command will be copied to the load address 4872 (and eventually uncompressed), but NOT be started. 4873 This can be used to load and uncompress arbitrary 4874 data. 4875 4876 fdt_high - if set this restricts the maximum address that the 4877 flattened device tree will be copied into upon boot. 4878 For example, if you have a system with 1 GB memory 4879 at physical address 0x10000000, while Linux kernel 4880 only recognizes the first 704 MB as low memory, you 4881 may need to set fdt_high as 0x3C000000 to have the 4882 device tree blob be copied to the maximum address 4883 of the 704 MB low memory, so that Linux kernel can 4884 access it during the boot procedure. 4885 4886 If this is set to the special value 0xFFFFFFFF then 4887 the fdt will not be copied at all on boot. For this 4888 to work it must reside in writable memory, have 4889 sufficient padding on the end of it for u-boot to 4890 add the information it needs into it, and the memory 4891 must be accessible by the kernel. 4892 4893 fdtcontroladdr- if set this is the address of the control flattened 4894 device tree used by U-Boot when CONFIG_OF_CONTROL is 4895 defined. 4896 4897 i2cfast - (PPC405GP|PPC405EP only) 4898 if set to 'y' configures Linux I2C driver for fast 4899 mode (400kHZ). This environment variable is used in 4900 initialization code. So, for changes to be effective 4901 it must be saved and board must be reset. 4902 4903 initrd_high - restrict positioning of initrd images: 4904 If this variable is not set, initrd images will be 4905 copied to the highest possible address in RAM; this 4906 is usually what you want since it allows for 4907 maximum initrd size. If for some reason you want to 4908 make sure that the initrd image is loaded below the 4909 CONFIG_SYS_BOOTMAPSZ limit, you can set this environment 4910 variable to a value of "no" or "off" or "0". 4911 Alternatively, you can set it to a maximum upper 4912 address to use (U-Boot will still check that it 4913 does not overwrite the U-Boot stack and data). 4914 4915 For instance, when you have a system with 16 MB 4916 RAM, and want to reserve 4 MB from use by Linux, 4917 you can do this by adding "mem=12M" to the value of 4918 the "bootargs" variable. However, now you must make 4919 sure that the initrd image is placed in the first 4920 12 MB as well - this can be done with 4921 4922 setenv initrd_high 00c00000 4923 4924 If you set initrd_high to 0xFFFFFFFF, this is an 4925 indication to U-Boot that all addresses are legal 4926 for the Linux kernel, including addresses in flash 4927 memory. In this case U-Boot will NOT COPY the 4928 ramdisk at all. This may be useful to reduce the 4929 boot time on your system, but requires that this 4930 feature is supported by your Linux kernel. 4931 4932 ipaddr - IP address; needed for tftpboot command 4933 4934 loadaddr - Default load address for commands like "bootp", 4935 "rarpboot", "tftpboot", "loadb" or "diskboot" 4936 4937 loads_echo - see CONFIG_LOADS_ECHO 4938 4939 serverip - TFTP server IP address; needed for tftpboot command 4940 4941 bootretry - see CONFIG_BOOT_RETRY_TIME 4942 4943 bootdelaykey - see CONFIG_AUTOBOOT_DELAY_STR 4944 4945 bootstopkey - see CONFIG_AUTOBOOT_STOP_STR 4946 4947 ethprime - controls which interface is used first. 4948 4949 ethact - controls which interface is currently active. 4950 For example you can do the following 4951 4952 => setenv ethact FEC 4953 => ping 192.168.0.1 # traffic sent on FEC 4954 => setenv ethact SCC 4955 => ping 10.0.0.1 # traffic sent on SCC 4956 4957 ethrotate - When set to "no" U-Boot does not go through all 4958 available network interfaces. 4959 It just stays at the currently selected interface. 4960 4961 netretry - When set to "no" each network operation will 4962 either succeed or fail without retrying. 4963 When set to "once" the network operation will 4964 fail when all the available network interfaces 4965 are tried once without success. 4966 Useful on scripts which control the retry operation 4967 themselves. 4968 4969 npe_ucode - set load address for the NPE microcode 4970 4971 silent_linux - If set then Linux will be told to boot silently, by 4972 changing the console to be empty. If "yes" it will be 4973 made silent. If "no" it will not be made silent. If 4974 unset, then it will be made silent if the U-Boot console 4975 is silent. 4976 4977 tftpsrcp - If this is set, the value is used for TFTP's 4978 UDP source port. 4979 4980 tftpdstp - If this is set, the value is used for TFTP's UDP 4981 destination port instead of the Well Know Port 69. 4982 4983 tftpblocksize - Block size to use for TFTP transfers; if not set, 4984 we use the TFTP server's default block size 4985 4986 tftptimeout - Retransmission timeout for TFTP packets (in milli- 4987 seconds, minimum value is 1000 = 1 second). Defines 4988 when a packet is considered to be lost so it has to 4989 be retransmitted. The default is 5000 = 5 seconds. 4990 Lowering this value may make downloads succeed 4991 faster in networks with high packet loss rates or 4992 with unreliable TFTP servers. 4993 4994 tftptimeoutcountmax - maximum count of TFTP timeouts (no 4995 unit, minimum value = 0). Defines how many timeouts 4996 can happen during a single file transfer before that 4997 transfer is aborted. The default is 10, and 0 means 4998 'no timeouts allowed'. Increasing this value may help 4999 downloads succeed with high packet loss rates, or with 5000 unreliable TFTP servers or client hardware. 5001 5002 vlan - When set to a value < 4095 the traffic over 5003 Ethernet is encapsulated/received over 802.1q 5004 VLAN tagged frames. 5005 5006 bootpretryperiod - Period during which BOOTP/DHCP sends retries. 5007 Unsigned value, in milliseconds. If not set, the period will 5008 be either the default (28000), or a value based on 5009 CONFIG_NET_RETRY_COUNT, if defined. This value has 5010 precedence over the valu based on CONFIG_NET_RETRY_COUNT. 5011 5012The following image location variables contain the location of images 5013used in booting. The "Image" column gives the role of the image and is 5014not an environment variable name. The other columns are environment 5015variable names. "File Name" gives the name of the file on a TFTP 5016server, "RAM Address" gives the location in RAM the image will be 5017loaded to, and "Flash Location" gives the image's address in NOR 5018flash or offset in NAND flash. 5019 5020*Note* - these variables don't have to be defined for all boards, some 5021boards currently use other variables for these purposes, and some 5022boards use these variables for other purposes. 5023 5024Image File Name RAM Address Flash Location 5025----- --------- ----------- -------------- 5026u-boot u-boot u-boot_addr_r u-boot_addr 5027Linux kernel bootfile kernel_addr_r kernel_addr 5028device tree blob fdtfile fdt_addr_r fdt_addr 5029ramdisk ramdiskfile ramdisk_addr_r ramdisk_addr 5030 5031The following environment variables may be used and automatically 5032updated by the network boot commands ("bootp" and "rarpboot"), 5033depending the information provided by your boot server: 5034 5035 bootfile - see above 5036 dnsip - IP address of your Domain Name Server 5037 dnsip2 - IP address of your secondary Domain Name Server 5038 gatewayip - IP address of the Gateway (Router) to use 5039 hostname - Target hostname 5040 ipaddr - see above 5041 netmask - Subnet Mask 5042 rootpath - Pathname of the root filesystem on the NFS server 5043 serverip - see above 5044 5045 5046There are two special Environment Variables: 5047 5048 serial# - contains hardware identification information such 5049 as type string and/or serial number 5050 ethaddr - Ethernet address 5051 5052These variables can be set only once (usually during manufacturing of 5053the board). U-Boot refuses to delete or overwrite these variables 5054once they have been set once. 5055 5056 5057Further special Environment Variables: 5058 5059 ver - Contains the U-Boot version string as printed 5060 with the "version" command. This variable is 5061 readonly (see CONFIG_VERSION_VARIABLE). 5062 5063 5064Please note that changes to some configuration parameters may take 5065only effect after the next boot (yes, that's just like Windoze :-). 5066 5067 5068Callback functions for environment variables: 5069--------------------------------------------- 5070 5071For some environment variables, the behavior of u-boot needs to change 5072when their values are changed. This functionality allows functions to 5073be associated with arbitrary variables. On creation, overwrite, or 5074deletion, the callback will provide the opportunity for some side 5075effect to happen or for the change to be rejected. 5076 5077The callbacks are named and associated with a function using the 5078U_BOOT_ENV_CALLBACK macro in your board or driver code. 5079 5080These callbacks are associated with variables in one of two ways. The 5081static list can be added to by defining CONFIG_ENV_CALLBACK_LIST_STATIC 5082in the board configuration to a string that defines a list of 5083associations. The list must be in the following format: 5084 5085 entry = variable_name[:callback_name] 5086 list = entry[,list] 5087 5088If the callback name is not specified, then the callback is deleted. 5089Spaces are also allowed anywhere in the list. 5090 5091Callbacks can also be associated by defining the ".callbacks" variable 5092with the same list format above. Any association in ".callbacks" will 5093override any association in the static list. You can define 5094CONFIG_ENV_CALLBACK_LIST_DEFAULT to a list (string) to define the 5095".callbacks" environment variable in the default or embedded environment. 5096 5097If CONFIG_REGEX is defined, the variable_name above is evaluated as a 5098regular expression. This allows multiple variables to be connected to 5099the same callback without explicitly listing them all out. 5100 5101 5102Command Line Parsing: 5103===================== 5104 5105There are two different command line parsers available with U-Boot: 5106the old "simple" one, and the much more powerful "hush" shell: 5107 5108Old, simple command line parser: 5109-------------------------------- 5110 5111- supports environment variables (through setenv / saveenv commands) 5112- several commands on one line, separated by ';' 5113- variable substitution using "... ${name} ..." syntax 5114- special characters ('$', ';') can be escaped by prefixing with '\', 5115 for example: 5116 setenv bootcmd bootm \${address} 5117- You can also escape text by enclosing in single apostrophes, for example: 5118 setenv addip 'setenv bootargs $bootargs ip=$ipaddr:$serverip:$gatewayip:$netmask:$hostname::off' 5119 5120Hush shell: 5121----------- 5122 5123- similar to Bourne shell, with control structures like 5124 if...then...else...fi, for...do...done; while...do...done, 5125 until...do...done, ... 5126- supports environment ("global") variables (through setenv / saveenv 5127 commands) and local shell variables (through standard shell syntax 5128 "name=value"); only environment variables can be used with "run" 5129 command 5130 5131General rules: 5132-------------- 5133 5134(1) If a command line (or an environment variable executed by a "run" 5135 command) contains several commands separated by semicolon, and 5136 one of these commands fails, then the remaining commands will be 5137 executed anyway. 5138 5139(2) If you execute several variables with one call to run (i. e. 5140 calling run with a list of variables as arguments), any failing 5141 command will cause "run" to terminate, i. e. the remaining 5142 variables are not executed. 5143 5144Note for Redundant Ethernet Interfaces: 5145======================================= 5146 5147Some boards come with redundant Ethernet interfaces; U-Boot supports 5148such configurations and is capable of automatic selection of a 5149"working" interface when needed. MAC assignment works as follows: 5150 5151Network interfaces are numbered eth0, eth1, eth2, ... Corresponding 5152MAC addresses can be stored in the environment as "ethaddr" (=>eth0), 5153"eth1addr" (=>eth1), "eth2addr", ... 5154 5155If the network interface stores some valid MAC address (for instance 5156in SROM), this is used as default address if there is NO correspon- 5157ding setting in the environment; if the corresponding environment 5158variable is set, this overrides the settings in the card; that means: 5159 5160o If the SROM has a valid MAC address, and there is no address in the 5161 environment, the SROM's address is used. 5162 5163o If there is no valid address in the SROM, and a definition in the 5164 environment exists, then the value from the environment variable is 5165 used. 5166 5167o If both the SROM and the environment contain a MAC address, and 5168 both addresses are the same, this MAC address is used. 5169 5170o If both the SROM and the environment contain a MAC address, and the 5171 addresses differ, the value from the environment is used and a 5172 warning is printed. 5173 5174o If neither SROM nor the environment contain a MAC address, an error 5175 is raised. If CONFIG_NET_RANDOM_ETHADDR is defined, then in this case 5176 a random, locally-assigned MAC is used. 5177 5178If Ethernet drivers implement the 'write_hwaddr' function, valid MAC addresses 5179will be programmed into hardware as part of the initialization process. This 5180may be skipped by setting the appropriate 'ethmacskip' environment variable. 5181The naming convention is as follows: 5182"ethmacskip" (=>eth0), "eth1macskip" (=>eth1) etc. 5183 5184Image Formats: 5185============== 5186 5187U-Boot is capable of booting (and performing other auxiliary operations on) 5188images in two formats: 5189 5190New uImage format (FIT) 5191----------------------- 5192 5193Flexible and powerful format based on Flattened Image Tree -- FIT (similar 5194to Flattened Device Tree). It allows the use of images with multiple 5195components (several kernels, ramdisks, etc.), with contents protected by 5196SHA1, MD5 or CRC32. More details are found in the doc/uImage.FIT directory. 5197 5198 5199Old uImage format 5200----------------- 5201 5202Old image format is based on binary files which can be basically anything, 5203preceded by a special header; see the definitions in include/image.h for 5204details; basically, the header defines the following image properties: 5205 5206* Target Operating System (Provisions for OpenBSD, NetBSD, FreeBSD, 5207 4.4BSD, Linux, SVR4, Esix, Solaris, Irix, SCO, Dell, NCR, VxWorks, 5208 LynxOS, pSOS, QNX, RTEMS, INTEGRITY; 5209 Currently supported: Linux, NetBSD, VxWorks, QNX, RTEMS, LynxOS, 5210 INTEGRITY). 5211* Target CPU Architecture (Provisions for Alpha, ARM, AVR32, Intel x86, 5212 IA64, MIPS, NDS32, Nios II, PowerPC, IBM S390, SuperH, Sparc, Sparc 64 Bit; 5213 Currently supported: ARM, AVR32, Intel x86, MIPS, NDS32, Nios II, PowerPC). 5214* Compression Type (uncompressed, gzip, bzip2) 5215* Load Address 5216* Entry Point 5217* Image Name 5218* Image Timestamp 5219 5220The header is marked by a special Magic Number, and both the header 5221and the data portions of the image are secured against corruption by 5222CRC32 checksums. 5223 5224 5225Linux Support: 5226============== 5227 5228Although U-Boot should support any OS or standalone application 5229easily, the main focus has always been on Linux during the design of 5230U-Boot. 5231 5232U-Boot includes many features that so far have been part of some 5233special "boot loader" code within the Linux kernel. Also, any 5234"initrd" images to be used are no longer part of one big Linux image; 5235instead, kernel and "initrd" are separate images. This implementation 5236serves several purposes: 5237 5238- the same features can be used for other OS or standalone 5239 applications (for instance: using compressed images to reduce the 5240 Flash memory footprint) 5241 5242- it becomes much easier to port new Linux kernel versions because 5243 lots of low-level, hardware dependent stuff are done by U-Boot 5244 5245- the same Linux kernel image can now be used with different "initrd" 5246 images; of course this also means that different kernel images can 5247 be run with the same "initrd". This makes testing easier (you don't 5248 have to build a new "zImage.initrd" Linux image when you just 5249 change a file in your "initrd"). Also, a field-upgrade of the 5250 software is easier now. 5251 5252 5253Linux HOWTO: 5254============ 5255 5256Porting Linux to U-Boot based systems: 5257--------------------------------------- 5258 5259U-Boot cannot save you from doing all the necessary modifications to 5260configure the Linux device drivers for use with your target hardware 5261(no, we don't intend to provide a full virtual machine interface to 5262Linux :-). 5263 5264But now you can ignore ALL boot loader code (in arch/powerpc/mbxboot). 5265 5266Just make sure your machine specific header file (for instance 5267include/asm-ppc/tqm8xx.h) includes the same definition of the Board 5268Information structure as we define in include/asm-<arch>/u-boot.h, 5269and make sure that your definition of IMAP_ADDR uses the same value 5270as your U-Boot configuration in CONFIG_SYS_IMMR. 5271 5272Note that U-Boot now has a driver model, a unified model for drivers. 5273If you are adding a new driver, plumb it into driver model. If there 5274is no uclass available, you are encouraged to create one. See 5275doc/driver-model. 5276 5277 5278Configuring the Linux kernel: 5279----------------------------- 5280 5281No specific requirements for U-Boot. Make sure you have some root 5282device (initial ramdisk, NFS) for your target system. 5283 5284 5285Building a Linux Image: 5286----------------------- 5287 5288With U-Boot, "normal" build targets like "zImage" or "bzImage" are 5289not used. If you use recent kernel source, a new build target 5290"uImage" will exist which automatically builds an image usable by 5291U-Boot. Most older kernels also have support for a "pImage" target, 5292which was introduced for our predecessor project PPCBoot and uses a 5293100% compatible format. 5294 5295Example: 5296 5297 make TQM850L_defconfig 5298 make oldconfig 5299 make dep 5300 make uImage 5301 5302The "uImage" build target uses a special tool (in 'tools/mkimage') to 5303encapsulate a compressed Linux kernel image with header information, 5304CRC32 checksum etc. for use with U-Boot. This is what we are doing: 5305 5306* build a standard "vmlinux" kernel image (in ELF binary format): 5307 5308* convert the kernel into a raw binary image: 5309 5310 ${CROSS_COMPILE}-objcopy -O binary \ 5311 -R .note -R .comment \ 5312 -S vmlinux linux.bin 5313 5314* compress the binary image: 5315 5316 gzip -9 linux.bin 5317 5318* package compressed binary image for U-Boot: 5319 5320 mkimage -A ppc -O linux -T kernel -C gzip \ 5321 -a 0 -e 0 -n "Linux Kernel Image" \ 5322 -d linux.bin.gz uImage 5323 5324 5325The "mkimage" tool can also be used to create ramdisk images for use 5326with U-Boot, either separated from the Linux kernel image, or 5327combined into one file. "mkimage" encapsulates the images with a 64 5328byte header containing information about target architecture, 5329operating system, image type, compression method, entry points, time 5330stamp, CRC32 checksums, etc. 5331 5332"mkimage" can be called in two ways: to verify existing images and 5333print the header information, or to build new images. 5334 5335In the first form (with "-l" option) mkimage lists the information 5336contained in the header of an existing U-Boot image; this includes 5337checksum verification: 5338 5339 tools/mkimage -l image 5340 -l ==> list image header information 5341 5342The second form (with "-d" option) is used to build a U-Boot image 5343from a "data file" which is used as image payload: 5344 5345 tools/mkimage -A arch -O os -T type -C comp -a addr -e ep \ 5346 -n name -d data_file image 5347 -A ==> set architecture to 'arch' 5348 -O ==> set operating system to 'os' 5349 -T ==> set image type to 'type' 5350 -C ==> set compression type 'comp' 5351 -a ==> set load address to 'addr' (hex) 5352 -e ==> set entry point to 'ep' (hex) 5353 -n ==> set image name to 'name' 5354 -d ==> use image data from 'datafile' 5355 5356Right now, all Linux kernels for PowerPC systems use the same load 5357address (0x00000000), but the entry point address depends on the 5358kernel version: 5359 5360- 2.2.x kernels have the entry point at 0x0000000C, 5361- 2.3.x and later kernels have the entry point at 0x00000000. 5362 5363So a typical call to build a U-Boot image would read: 5364 5365 -> tools/mkimage -n '2.4.4 kernel for TQM850L' \ 5366 > -A ppc -O linux -T kernel -C gzip -a 0 -e 0 \ 5367 > -d /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/powerpc/coffboot/vmlinux.gz \ 5368 > examples/uImage.TQM850L 5369 Image Name: 2.4.4 kernel for TQM850L 5370 Created: Wed Jul 19 02:34:59 2000 5371 Image Type: PowerPC Linux Kernel Image (gzip compressed) 5372 Data Size: 335725 Bytes = 327.86 kB = 0.32 MB 5373 Load Address: 0x00000000 5374 Entry Point: 0x00000000 5375 5376To verify the contents of the image (or check for corruption): 5377 5378 -> tools/mkimage -l examples/uImage.TQM850L 5379 Image Name: 2.4.4 kernel for TQM850L 5380 Created: Wed Jul 19 02:34:59 2000 5381 Image Type: PowerPC Linux Kernel Image (gzip compressed) 5382 Data Size: 335725 Bytes = 327.86 kB = 0.32 MB 5383 Load Address: 0x00000000 5384 Entry Point: 0x00000000 5385 5386NOTE: for embedded systems where boot time is critical you can trade 5387speed for memory and install an UNCOMPRESSED image instead: this 5388needs more space in Flash, but boots much faster since it does not 5389need to be uncompressed: 5390 5391 -> gunzip /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/powerpc/coffboot/vmlinux.gz 5392 -> tools/mkimage -n '2.4.4 kernel for TQM850L' \ 5393 > -A ppc -O linux -T kernel -C none -a 0 -e 0 \ 5394 > -d /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/powerpc/coffboot/vmlinux \ 5395 > examples/uImage.TQM850L-uncompressed 5396 Image Name: 2.4.4 kernel for TQM850L 5397 Created: Wed Jul 19 02:34:59 2000 5398 Image Type: PowerPC Linux Kernel Image (uncompressed) 5399 Data Size: 792160 Bytes = 773.59 kB = 0.76 MB 5400 Load Address: 0x00000000 5401 Entry Point: 0x00000000 5402 5403 5404Similar you can build U-Boot images from a 'ramdisk.image.gz' file 5405when your kernel is intended to use an initial ramdisk: 5406 5407 -> tools/mkimage -n 'Simple Ramdisk Image' \ 5408 > -A ppc -O linux -T ramdisk -C gzip \ 5409 > -d /LinuxPPC/images/SIMPLE-ramdisk.image.gz examples/simple-initrd 5410 Image Name: Simple Ramdisk Image 5411 Created: Wed Jan 12 14:01:50 2000 5412 Image Type: PowerPC Linux RAMDisk Image (gzip compressed) 5413 Data Size: 566530 Bytes = 553.25 kB = 0.54 MB 5414 Load Address: 0x00000000 5415 Entry Point: 0x00000000 5416 5417The "dumpimage" is a tool to disassemble images built by mkimage. Its "-i" 5418option performs the converse operation of the mkimage's second form (the "-d" 5419option). Given an image built by mkimage, the dumpimage extracts a "data file" 5420from the image: 5421 5422 tools/dumpimage -i image -T type -p position data_file 5423 -i ==> extract from the 'image' a specific 'data_file' 5424 -T ==> set image type to 'type' 5425 -p ==> 'position' (starting at 0) of the 'data_file' inside the 'image' 5426 5427 5428Installing a Linux Image: 5429------------------------- 5430 5431To downloading a U-Boot image over the serial (console) interface, 5432you must convert the image to S-Record format: 5433 5434 objcopy -I binary -O srec examples/image examples/image.srec 5435 5436The 'objcopy' does not understand the information in the U-Boot 5437image header, so the resulting S-Record file will be relative to 5438address 0x00000000. To load it to a given address, you need to 5439specify the target address as 'offset' parameter with the 'loads' 5440command. 5441 5442Example: install the image to address 0x40100000 (which on the 5443TQM8xxL is in the first Flash bank): 5444 5445 => erase 40100000 401FFFFF 5446 5447 .......... done 5448 Erased 8 sectors 5449 5450 => loads 40100000 5451 ## Ready for S-Record download ... 5452 ~>examples/image.srec 5453 1 2 3 4 5 6 7 8 9 10 11 12 13 ... 5454 ... 5455 15989 15990 15991 15992 5456 [file transfer complete] 5457 [connected] 5458 ## Start Addr = 0x00000000 5459 5460 5461You can check the success of the download using the 'iminfo' command; 5462this includes a checksum verification so you can be sure no data 5463corruption happened: 5464 5465 => imi 40100000 5466 5467 ## Checking Image at 40100000 ... 5468 Image Name: 2.2.13 for initrd on TQM850L 5469 Image Type: PowerPC Linux Kernel Image (gzip compressed) 5470 Data Size: 335725 Bytes = 327 kB = 0 MB 5471 Load Address: 00000000 5472 Entry Point: 0000000c 5473 Verifying Checksum ... OK 5474 5475 5476Boot Linux: 5477----------- 5478 5479The "bootm" command is used to boot an application that is stored in 5480memory (RAM or Flash). In case of a Linux kernel image, the contents 5481of the "bootargs" environment variable is passed to the kernel as 5482parameters. You can check and modify this variable using the 5483"printenv" and "setenv" commands: 5484 5485 5486 => printenv bootargs 5487 bootargs=root=/dev/ram 5488 5489 => setenv bootargs root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2 5490 5491 => printenv bootargs 5492 bootargs=root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2 5493 5494 => bootm 40020000 5495 ## Booting Linux kernel at 40020000 ... 5496 Image Name: 2.2.13 for NFS on TQM850L 5497 Image Type: PowerPC Linux Kernel Image (gzip compressed) 5498 Data Size: 381681 Bytes = 372 kB = 0 MB 5499 Load Address: 00000000 5500 Entry Point: 0000000c 5501 Verifying Checksum ... OK 5502 Uncompressing Kernel Image ... OK 5503 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 5504 Boot arguments: root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2 5505 time_init: decrementer frequency = 187500000/60 5506 Calibrating delay loop... 49.77 BogoMIPS 5507 Memory: 15208k available (700k kernel code, 444k data, 32k init) [c0000000,c1000000] 5508 ... 5509 5510If you want to boot a Linux kernel with initial RAM disk, you pass 5511the memory addresses of both the kernel and the initrd image (PPBCOOT 5512format!) to the "bootm" command: 5513 5514 => imi 40100000 40200000 5515 5516 ## Checking Image at 40100000 ... 5517 Image Name: 2.2.13 for initrd on TQM850L 5518 Image Type: PowerPC Linux Kernel Image (gzip compressed) 5519 Data Size: 335725 Bytes = 327 kB = 0 MB 5520 Load Address: 00000000 5521 Entry Point: 0000000c 5522 Verifying Checksum ... OK 5523 5524 ## Checking Image at 40200000 ... 5525 Image Name: Simple Ramdisk Image 5526 Image Type: PowerPC Linux RAMDisk Image (gzip compressed) 5527 Data Size: 566530 Bytes = 553 kB = 0 MB 5528 Load Address: 00000000 5529 Entry Point: 00000000 5530 Verifying Checksum ... OK 5531 5532 => bootm 40100000 40200000 5533 ## Booting Linux kernel at 40100000 ... 5534 Image Name: 2.2.13 for initrd on TQM850L 5535 Image Type: PowerPC Linux Kernel Image (gzip compressed) 5536 Data Size: 335725 Bytes = 327 kB = 0 MB 5537 Load Address: 00000000 5538 Entry Point: 0000000c 5539 Verifying Checksum ... OK 5540 Uncompressing Kernel Image ... OK 5541 ## Loading RAMDisk Image at 40200000 ... 5542 Image Name: Simple Ramdisk Image 5543 Image Type: PowerPC Linux RAMDisk Image (gzip compressed) 5544 Data Size: 566530 Bytes = 553 kB = 0 MB 5545 Load Address: 00000000 5546 Entry Point: 00000000 5547 Verifying Checksum ... OK 5548 Loading Ramdisk ... OK 5549 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 5550 Boot arguments: root=/dev/ram 5551 time_init: decrementer frequency = 187500000/60 5552 Calibrating delay loop... 49.77 BogoMIPS 5553 ... 5554 RAMDISK: Compressed image found at block 0 5555 VFS: Mounted root (ext2 filesystem). 5556 5557 bash# 5558 5559Boot Linux and pass a flat device tree: 5560----------- 5561 5562First, U-Boot must be compiled with the appropriate defines. See the section 5563titled "Linux Kernel Interface" above for a more in depth explanation. The 5564following is an example of how to start a kernel and pass an updated 5565flat device tree: 5566 5567=> print oftaddr 5568oftaddr=0x300000 5569=> print oft 5570oft=oftrees/mpc8540ads.dtb 5571=> tftp $oftaddr $oft 5572Speed: 1000, full duplex 5573Using TSEC0 device 5574TFTP from server 192.168.1.1; our IP address is 192.168.1.101 5575Filename 'oftrees/mpc8540ads.dtb'. 5576Load address: 0x300000 5577Loading: # 5578done 5579Bytes transferred = 4106 (100a hex) 5580=> tftp $loadaddr $bootfile 5581Speed: 1000, full duplex 5582Using TSEC0 device 5583TFTP from server 192.168.1.1; our IP address is 192.168.1.2 5584Filename 'uImage'. 5585Load address: 0x200000 5586Loading:############ 5587done 5588Bytes transferred = 1029407 (fb51f hex) 5589=> print loadaddr 5590loadaddr=200000 5591=> print oftaddr 5592oftaddr=0x300000 5593=> bootm $loadaddr - $oftaddr 5594## Booting image at 00200000 ... 5595 Image Name: Linux-2.6.17-dirty 5596 Image Type: PowerPC Linux Kernel Image (gzip compressed) 5597 Data Size: 1029343 Bytes = 1005.2 kB 5598 Load Address: 00000000 5599 Entry Point: 00000000 5600 Verifying Checksum ... OK 5601 Uncompressing Kernel Image ... OK 5602Booting using flat device tree at 0x300000 5603Using MPC85xx ADS machine description 5604Memory CAM mapping: CAM0=256Mb, CAM1=256Mb, CAM2=0Mb residual: 0Mb 5605[snip] 5606 5607 5608More About U-Boot Image Types: 5609------------------------------ 5610 5611U-Boot supports the following image types: 5612 5613 "Standalone Programs" are directly runnable in the environment 5614 provided by U-Boot; it is expected that (if they behave 5615 well) you can continue to work in U-Boot after return from 5616 the Standalone Program. 5617 "OS Kernel Images" are usually images of some Embedded OS which 5618 will take over control completely. Usually these programs 5619 will install their own set of exception handlers, device 5620 drivers, set up the MMU, etc. - this means, that you cannot 5621 expect to re-enter U-Boot except by resetting the CPU. 5622 "RAMDisk Images" are more or less just data blocks, and their 5623 parameters (address, size) are passed to an OS kernel that is 5624 being started. 5625 "Multi-File Images" contain several images, typically an OS 5626 (Linux) kernel image and one or more data images like 5627 RAMDisks. This construct is useful for instance when you want 5628 to boot over the network using BOOTP etc., where the boot 5629 server provides just a single image file, but you want to get 5630 for instance an OS kernel and a RAMDisk image. 5631 5632 "Multi-File Images" start with a list of image sizes, each 5633 image size (in bytes) specified by an "uint32_t" in network 5634 byte order. This list is terminated by an "(uint32_t)0". 5635 Immediately after the terminating 0 follow the images, one by 5636 one, all aligned on "uint32_t" boundaries (size rounded up to 5637 a multiple of 4 bytes). 5638 5639 "Firmware Images" are binary images containing firmware (like 5640 U-Boot or FPGA images) which usually will be programmed to 5641 flash memory. 5642 5643 "Script files" are command sequences that will be executed by 5644 U-Boot's command interpreter; this feature is especially 5645 useful when you configure U-Boot to use a real shell (hush) 5646 as command interpreter. 5647 5648Booting the Linux zImage: 5649------------------------- 5650 5651On some platforms, it's possible to boot Linux zImage. This is done 5652using the "bootz" command. The syntax of "bootz" command is the same 5653as the syntax of "bootm" command. 5654 5655Note, defining the CONFIG_SUPPORT_RAW_INITRD allows user to supply 5656kernel with raw initrd images. The syntax is slightly different, the 5657address of the initrd must be augmented by it's size, in the following 5658format: "<initrd addres>:<initrd size>". 5659 5660 5661Standalone HOWTO: 5662================= 5663 5664One of the features of U-Boot is that you can dynamically load and 5665run "standalone" applications, which can use some resources of 5666U-Boot like console I/O functions or interrupt services. 5667 5668Two simple examples are included with the sources: 5669 5670"Hello World" Demo: 5671------------------- 5672 5673'examples/hello_world.c' contains a small "Hello World" Demo 5674application; it is automatically compiled when you build U-Boot. 5675It's configured to run at address 0x00040004, so you can play with it 5676like that: 5677 5678 => loads 5679 ## Ready for S-Record download ... 5680 ~>examples/hello_world.srec 5681 1 2 3 4 5 6 7 8 9 10 11 ... 5682 [file transfer complete] 5683 [connected] 5684 ## Start Addr = 0x00040004 5685 5686 => go 40004 Hello World! This is a test. 5687 ## Starting application at 0x00040004 ... 5688 Hello World 5689 argc = 7 5690 argv[0] = "40004" 5691 argv[1] = "Hello" 5692 argv[2] = "World!" 5693 argv[3] = "This" 5694 argv[4] = "is" 5695 argv[5] = "a" 5696 argv[6] = "test." 5697 argv[7] = "<NULL>" 5698 Hit any key to exit ... 5699 5700 ## Application terminated, rc = 0x0 5701 5702Another example, which demonstrates how to register a CPM interrupt 5703handler with the U-Boot code, can be found in 'examples/timer.c'. 5704Here, a CPM timer is set up to generate an interrupt every second. 5705The interrupt service routine is trivial, just printing a '.' 5706character, but this is just a demo program. The application can be 5707controlled by the following keys: 5708 5709 ? - print current values og the CPM Timer registers 5710 b - enable interrupts and start timer 5711 e - stop timer and disable interrupts 5712 q - quit application 5713 5714 => loads 5715 ## Ready for S-Record download ... 5716 ~>examples/timer.srec 5717 1 2 3 4 5 6 7 8 9 10 11 ... 5718 [file transfer complete] 5719 [connected] 5720 ## Start Addr = 0x00040004 5721 5722 => go 40004 5723 ## Starting application at 0x00040004 ... 5724 TIMERS=0xfff00980 5725 Using timer 1 5726 tgcr @ 0xfff00980, tmr @ 0xfff00990, trr @ 0xfff00994, tcr @ 0xfff00998, tcn @ 0xfff0099c, ter @ 0xfff009b0 5727 5728Hit 'b': 5729 [q, b, e, ?] Set interval 1000000 us 5730 Enabling timer 5731Hit '?': 5732 [q, b, e, ?] ........ 5733 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0xef6, ter=0x0 5734Hit '?': 5735 [q, b, e, ?] . 5736 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x2ad4, ter=0x0 5737Hit '?': 5738 [q, b, e, ?] . 5739 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x1efc, ter=0x0 5740Hit '?': 5741 [q, b, e, ?] . 5742 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x169d, ter=0x0 5743Hit 'e': 5744 [q, b, e, ?] ...Stopping timer 5745Hit 'q': 5746 [q, b, e, ?] ## Application terminated, rc = 0x0 5747 5748 5749Minicom warning: 5750================ 5751 5752Over time, many people have reported problems when trying to use the 5753"minicom" terminal emulation program for serial download. I (wd) 5754consider minicom to be broken, and recommend not to use it. Under 5755Unix, I recommend to use C-Kermit for general purpose use (and 5756especially for kermit binary protocol download ("loadb" command), and 5757use "cu" for S-Record download ("loads" command). See 5758http://www.denx.de/wiki/view/DULG/SystemSetup#Section_4.3. 5759for help with kermit. 5760 5761 5762Nevertheless, if you absolutely want to use it try adding this 5763configuration to your "File transfer protocols" section: 5764 5765 Name Program Name U/D FullScr IO-Red. Multi 5766 X kermit /usr/bin/kermit -i -l %l -s Y U Y N N 5767 Y kermit /usr/bin/kermit -i -l %l -r N D Y N N 5768 5769 5770NetBSD Notes: 5771============= 5772 5773Starting at version 0.9.2, U-Boot supports NetBSD both as host 5774(build U-Boot) and target system (boots NetBSD/mpc8xx). 5775 5776Building requires a cross environment; it is known to work on 5777NetBSD/i386 with the cross-powerpc-netbsd-1.3 package (you will also 5778need gmake since the Makefiles are not compatible with BSD make). 5779Note that the cross-powerpc package does not install include files; 5780attempting to build U-Boot will fail because <machine/ansi.h> is 5781missing. This file has to be installed and patched manually: 5782 5783 # cd /usr/pkg/cross/powerpc-netbsd/include 5784 # mkdir powerpc 5785 # ln -s powerpc machine 5786 # cp /usr/src/sys/arch/powerpc/include/ansi.h powerpc/ansi.h 5787 # ${EDIT} powerpc/ansi.h ## must remove __va_list, _BSD_VA_LIST 5788 5789Native builds *don't* work due to incompatibilities between native 5790and U-Boot include files. 5791 5792Booting assumes that (the first part of) the image booted is a 5793stage-2 loader which in turn loads and then invokes the kernel 5794proper. Loader sources will eventually appear in the NetBSD source 5795tree (probably in sys/arc/mpc8xx/stand/u-boot_stage2/); in the 5796meantime, see ftp://ftp.denx.de/pub/u-boot/ppcboot_stage2.tar.gz 5797 5798 5799Implementation Internals: 5800========================= 5801 5802The following is not intended to be a complete description of every 5803implementation detail. However, it should help to understand the 5804inner workings of U-Boot and make it easier to port it to custom 5805hardware. 5806 5807 5808Initial Stack, Global Data: 5809--------------------------- 5810 5811The implementation of U-Boot is complicated by the fact that U-Boot 5812starts running out of ROM (flash memory), usually without access to 5813system RAM (because the memory controller is not initialized yet). 5814This means that we don't have writable Data or BSS segments, and BSS 5815is not initialized as zero. To be able to get a C environment working 5816at all, we have to allocate at least a minimal stack. Implementation 5817options for this are defined and restricted by the CPU used: Some CPU 5818models provide on-chip memory (like the IMMR area on MPC8xx and 5819MPC826x processors), on others (parts of) the data cache can be 5820locked as (mis-) used as memory, etc. 5821 5822 Chris Hallinan posted a good summary of these issues to the 5823 U-Boot mailing list: 5824 5825 Subject: RE: [U-Boot-Users] RE: More On Memory Bank x (nothingness)? 5826 From: "Chris Hallinan" <clh@net1plus.com> 5827 Date: Mon, 10 Feb 2003 16:43:46 -0500 (22:43 MET) 5828 ... 5829 5830 Correct me if I'm wrong, folks, but the way I understand it 5831 is this: Using DCACHE as initial RAM for Stack, etc, does not 5832 require any physical RAM backing up the cache. The cleverness 5833 is that the cache is being used as a temporary supply of 5834 necessary storage before the SDRAM controller is setup. It's 5835 beyond the scope of this list to explain the details, but you 5836 can see how this works by studying the cache architecture and 5837 operation in the architecture and processor-specific manuals. 5838 5839 OCM is On Chip Memory, which I believe the 405GP has 4K. It 5840 is another option for the system designer to use as an 5841 initial stack/RAM area prior to SDRAM being available. Either 5842 option should work for you. Using CS 4 should be fine if your 5843 board designers haven't used it for something that would 5844 cause you grief during the initial boot! It is frequently not 5845 used. 5846 5847 CONFIG_SYS_INIT_RAM_ADDR should be somewhere that won't interfere 5848 with your processor/board/system design. The default value 5849 you will find in any recent u-boot distribution in 5850 walnut.h should work for you. I'd set it to a value larger 5851 than your SDRAM module. If you have a 64MB SDRAM module, set 5852 it above 400_0000. Just make sure your board has no resources 5853 that are supposed to respond to that address! That code in 5854 start.S has been around a while and should work as is when 5855 you get the config right. 5856 5857 -Chris Hallinan 5858 DS4.COM, Inc. 5859 5860It is essential to remember this, since it has some impact on the C 5861code for the initialization procedures: 5862 5863* Initialized global data (data segment) is read-only. Do not attempt 5864 to write it. 5865 5866* Do not use any uninitialized global data (or implicitly initialized 5867 as zero data - BSS segment) at all - this is undefined, initiali- 5868 zation is performed later (when relocating to RAM). 5869 5870* Stack space is very limited. Avoid big data buffers or things like 5871 that. 5872 5873Having only the stack as writable memory limits means we cannot use 5874normal global data to share information between the code. But it 5875turned out that the implementation of U-Boot can be greatly 5876simplified by making a global data structure (gd_t) available to all 5877functions. We could pass a pointer to this data as argument to _all_ 5878functions, but this would bloat the code. Instead we use a feature of 5879the GCC compiler (Global Register Variables) to share the data: we 5880place a pointer (gd) to the global data into a register which we 5881reserve for this purpose. 5882 5883When choosing a register for such a purpose we are restricted by the 5884relevant (E)ABI specifications for the current architecture, and by 5885GCC's implementation. 5886 5887For PowerPC, the following registers have specific use: 5888 R1: stack pointer 5889 R2: reserved for system use 5890 R3-R4: parameter passing and return values 5891 R5-R10: parameter passing 5892 R13: small data area pointer 5893 R30: GOT pointer 5894 R31: frame pointer 5895 5896 (U-Boot also uses R12 as internal GOT pointer. r12 5897 is a volatile register so r12 needs to be reset when 5898 going back and forth between asm and C) 5899 5900 ==> U-Boot will use R2 to hold a pointer to the global data 5901 5902 Note: on PPC, we could use a static initializer (since the 5903 address of the global data structure is known at compile time), 5904 but it turned out that reserving a register results in somewhat 5905 smaller code - although the code savings are not that big (on 5906 average for all boards 752 bytes for the whole U-Boot image, 5907 624 text + 127 data). 5908 5909On ARM, the following registers are used: 5910 5911 R0: function argument word/integer result 5912 R1-R3: function argument word 5913 R9: platform specific 5914 R10: stack limit (used only if stack checking is enabled) 5915 R11: argument (frame) pointer 5916 R12: temporary workspace 5917 R13: stack pointer 5918 R14: link register 5919 R15: program counter 5920 5921 ==> U-Boot will use R9 to hold a pointer to the global data 5922 5923 Note: on ARM, only R_ARM_RELATIVE relocations are supported. 5924 5925On Nios II, the ABI is documented here: 5926 http://www.altera.com/literature/hb/nios2/n2cpu_nii51016.pdf 5927 5928 ==> U-Boot will use gp to hold a pointer to the global data 5929 5930 Note: on Nios II, we give "-G0" option to gcc and don't use gp 5931 to access small data sections, so gp is free. 5932 5933On NDS32, the following registers are used: 5934 5935 R0-R1: argument/return 5936 R2-R5: argument 5937 R15: temporary register for assembler 5938 R16: trampoline register 5939 R28: frame pointer (FP) 5940 R29: global pointer (GP) 5941 R30: link register (LP) 5942 R31: stack pointer (SP) 5943 PC: program counter (PC) 5944 5945 ==> U-Boot will use R10 to hold a pointer to the global data 5946 5947NOTE: DECLARE_GLOBAL_DATA_PTR must be used with file-global scope, 5948or current versions of GCC may "optimize" the code too much. 5949 5950Memory Management: 5951------------------ 5952 5953U-Boot runs in system state and uses physical addresses, i.e. the 5954MMU is not used either for address mapping nor for memory protection. 5955 5956The available memory is mapped to fixed addresses using the memory 5957controller. In this process, a contiguous block is formed for each 5958memory type (Flash, SDRAM, SRAM), even when it consists of several 5959physical memory banks. 5960 5961U-Boot is installed in the first 128 kB of the first Flash bank (on 5962TQM8xxL modules this is the range 0x40000000 ... 0x4001FFFF). After 5963booting and sizing and initializing DRAM, the code relocates itself 5964to the upper end of DRAM. Immediately below the U-Boot code some 5965memory is reserved for use by malloc() [see CONFIG_SYS_MALLOC_LEN 5966configuration setting]. Below that, a structure with global Board 5967Info data is placed, followed by the stack (growing downward). 5968 5969Additionally, some exception handler code is copied to the low 8 kB 5970of DRAM (0x00000000 ... 0x00001FFF). 5971 5972So a typical memory configuration with 16 MB of DRAM could look like 5973this: 5974 5975 0x0000 0000 Exception Vector code 5976 : 5977 0x0000 1FFF 5978 0x0000 2000 Free for Application Use 5979 : 5980 : 5981 5982 : 5983 : 5984 0x00FB FF20 Monitor Stack (Growing downward) 5985 0x00FB FFAC Board Info Data and permanent copy of global data 5986 0x00FC 0000 Malloc Arena 5987 : 5988 0x00FD FFFF 5989 0x00FE 0000 RAM Copy of Monitor Code 5990 ... eventually: LCD or video framebuffer 5991 ... eventually: pRAM (Protected RAM - unchanged by reset) 5992 0x00FF FFFF [End of RAM] 5993 5994 5995System Initialization: 5996---------------------- 5997 5998In the reset configuration, U-Boot starts at the reset entry point 5999(on most PowerPC systems at address 0x00000100). Because of the reset 6000configuration for CS0# this is a mirror of the on board Flash memory. 6001To be able to re-map memory U-Boot then jumps to its link address. 6002To be able to implement the initialization code in C, a (small!) 6003initial stack is set up in the internal Dual Ported RAM (in case CPUs 6004which provide such a feature like MPC8xx or MPC8260), or in a locked 6005part of the data cache. After that, U-Boot initializes the CPU core, 6006the caches and the SIU. 6007 6008Next, all (potentially) available memory banks are mapped using a 6009preliminary mapping. For example, we put them on 512 MB boundaries 6010(multiples of 0x20000000: SDRAM on 0x00000000 and 0x20000000, Flash 6011on 0x40000000 and 0x60000000, SRAM on 0x80000000). Then UPM A is 6012programmed for SDRAM access. Using the temporary configuration, a 6013simple memory test is run that determines the size of the SDRAM 6014banks. 6015 6016When there is more than one SDRAM bank, and the banks are of 6017different size, the largest is mapped first. For equal size, the first 6018bank (CS2#) is mapped first. The first mapping is always for address 60190x00000000, with any additional banks following immediately to create 6020contiguous memory starting from 0. 6021 6022Then, the monitor installs itself at the upper end of the SDRAM area 6023and allocates memory for use by malloc() and for the global Board 6024Info data; also, the exception vector code is copied to the low RAM 6025pages, and the final stack is set up. 6026 6027Only after this relocation will you have a "normal" C environment; 6028until that you are restricted in several ways, mostly because you are 6029running from ROM, and because the code will have to be relocated to a 6030new address in RAM. 6031 6032 6033U-Boot Porting Guide: 6034---------------------- 6035 6036[Based on messages by Jerry Van Baren in the U-Boot-Users mailing 6037list, October 2002] 6038 6039 6040int main(int argc, char *argv[]) 6041{ 6042 sighandler_t no_more_time; 6043 6044 signal(SIGALRM, no_more_time); 6045 alarm(PROJECT_DEADLINE - toSec (3 * WEEK)); 6046 6047 if (available_money > available_manpower) { 6048 Pay consultant to port U-Boot; 6049 return 0; 6050 } 6051 6052 Download latest U-Boot source; 6053 6054 Subscribe to u-boot mailing list; 6055 6056 if (clueless) 6057 email("Hi, I am new to U-Boot, how do I get started?"); 6058 6059 while (learning) { 6060 Read the README file in the top level directory; 6061 Read http://www.denx.de/twiki/bin/view/DULG/Manual; 6062 Read applicable doc/*.README; 6063 Read the source, Luke; 6064 /* find . -name "*.[chS]" | xargs grep -i <keyword> */ 6065 } 6066 6067 if (available_money > toLocalCurrency ($2500)) 6068 Buy a BDI3000; 6069 else 6070 Add a lot of aggravation and time; 6071 6072 if (a similar board exists) { /* hopefully... */ 6073 cp -a board/<similar> board/<myboard> 6074 cp include/configs/<similar>.h include/configs/<myboard>.h 6075 } else { 6076 Create your own board support subdirectory; 6077 Create your own board include/configs/<myboard>.h file; 6078 } 6079 Edit new board/<myboard> files 6080 Edit new include/configs/<myboard>.h 6081 6082 while (!accepted) { 6083 while (!running) { 6084 do { 6085 Add / modify source code; 6086 } until (compiles); 6087 Debug; 6088 if (clueless) 6089 email("Hi, I am having problems..."); 6090 } 6091 Send patch file to the U-Boot email list; 6092 if (reasonable critiques) 6093 Incorporate improvements from email list code review; 6094 else 6095 Defend code as written; 6096 } 6097 6098 return 0; 6099} 6100 6101void no_more_time (int sig) 6102{ 6103 hire_a_guru(); 6104} 6105 6106 6107Coding Standards: 6108----------------- 6109 6110All contributions to U-Boot should conform to the Linux kernel 6111coding style; see the file "Documentation/CodingStyle" and the script 6112"scripts/Lindent" in your Linux kernel source directory. 6113 6114Source files originating from a different project (for example the 6115MTD subsystem) are generally exempt from these guidelines and are not 6116reformatted to ease subsequent migration to newer versions of those 6117sources. 6118 6119Please note that U-Boot is implemented in C (and to some small parts in 6120Assembler); no C++ is used, so please do not use C++ style comments (//) 6121in your code. 6122 6123Please also stick to the following formatting rules: 6124- remove any trailing white space 6125- use TAB characters for indentation and vertical alignment, not spaces 6126- make sure NOT to use DOS '\r\n' line feeds 6127- do not add more than 2 consecutive empty lines to source files 6128- do not add trailing empty lines to source files 6129 6130Submissions which do not conform to the standards may be returned 6131with a request to reformat the changes. 6132 6133 6134Submitting Patches: 6135------------------- 6136 6137Since the number of patches for U-Boot is growing, we need to 6138establish some rules. Submissions which do not conform to these rules 6139may be rejected, even when they contain important and valuable stuff. 6140 6141Please see http://www.denx.de/wiki/U-Boot/Patches for details. 6142 6143Patches shall be sent to the u-boot mailing list <u-boot@lists.denx.de>; 6144see http://lists.denx.de/mailman/listinfo/u-boot 6145 6146When you send a patch, please include the following information with 6147it: 6148 6149* For bug fixes: a description of the bug and how your patch fixes 6150 this bug. Please try to include a way of demonstrating that the 6151 patch actually fixes something. 6152 6153* For new features: a description of the feature and your 6154 implementation. 6155 6156* A CHANGELOG entry as plaintext (separate from the patch) 6157 6158* For major contributions, add a MAINTAINERS file with your 6159 information and associated file and directory references. 6160 6161* When you add support for a new board, don't forget to add a 6162 maintainer e-mail address to the boards.cfg file, too. 6163 6164* If your patch adds new configuration options, don't forget to 6165 document these in the README file. 6166 6167* The patch itself. If you are using git (which is *strongly* 6168 recommended) you can easily generate the patch using the 6169 "git format-patch". If you then use "git send-email" to send it to 6170 the U-Boot mailing list, you will avoid most of the common problems 6171 with some other mail clients. 6172 6173 If you cannot use git, use "diff -purN OLD NEW". If your version of 6174 diff does not support these options, then get the latest version of 6175 GNU diff. 6176 6177 The current directory when running this command shall be the parent 6178 directory of the U-Boot source tree (i. e. please make sure that 6179 your patch includes sufficient directory information for the 6180 affected files). 6181 6182 We prefer patches as plain text. MIME attachments are discouraged, 6183 and compressed attachments must not be used. 6184 6185* If one logical set of modifications affects or creates several 6186 files, all these changes shall be submitted in a SINGLE patch file. 6187 6188* Changesets that contain different, unrelated modifications shall be 6189 submitted as SEPARATE patches, one patch per changeset. 6190 6191 6192Notes: 6193 6194* Before sending the patch, run the buildman script on your patched 6195 source tree and make sure that no errors or warnings are reported 6196 for any of the boards. 6197 6198* Keep your modifications to the necessary minimum: A patch 6199 containing several unrelated changes or arbitrary reformats will be 6200 returned with a request to re-formatting / split it. 6201 6202* If you modify existing code, make sure that your new code does not 6203 add to the memory footprint of the code ;-) Small is beautiful! 6204 When adding new features, these should compile conditionally only 6205 (using #ifdef), and the resulting code with the new feature 6206 disabled must not need more memory than the old code without your 6207 modification. 6208 6209* Remember that there is a size limit of 100 kB per message on the 6210 u-boot mailing list. Bigger patches will be moderated. If they are 6211 reasonable and not too big, they will be acknowledged. But patches 6212 bigger than the size limit should be avoided. 6213