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 and CREDITS files to find out 38who contributed the specific port. The boards.cfg file lists board 39maintainers. 40 41Note: There is no CHANGELOG file in the actual U-Boot source tree; 42it can be created dynamically from the Git log using: 43 44 make CHANGELOG 45 46 47Where to get help: 48================== 49 50In case you have questions about, problems with or contributions for 51U-Boot you should send a message to the U-Boot mailing list at 52<u-boot@lists.denx.de>. There is also an archive of previous traffic 53on the mailing list - please search the archive before asking FAQ's. 54Please see http://lists.denx.de/pipermail/u-boot and 55http://dir.gmane.org/gmane.comp.boot-loaders.u-boot 56 57 58Where to get source code: 59========================= 60 61The U-Boot source code is maintained in the git repository at 62git://www.denx.de/git/u-boot.git ; you can browse it online at 63http://www.denx.de/cgi-bin/gitweb.cgi?p=u-boot.git;a=summary 64 65The "snapshot" links on this page allow you to download tarballs of 66any version you might be interested in. Official releases are also 67available for FTP download from the ftp://ftp.denx.de/pub/u-boot/ 68directory. 69 70Pre-built (and tested) images are available from 71ftp://ftp.denx.de/pub/u-boot/images/ 72 73 74Where we come from: 75=================== 76 77- start from 8xxrom sources 78- create PPCBoot project (http://sourceforge.net/projects/ppcboot) 79- clean up code 80- make it easier to add custom boards 81- make it possible to add other [PowerPC] CPUs 82- extend functions, especially: 83 * Provide extended interface to Linux boot loader 84 * S-Record download 85 * network boot 86 * PCMCIA / CompactFlash / ATA disk / SCSI ... boot 87- create ARMBoot project (http://sourceforge.net/projects/armboot) 88- add other CPU families (starting with ARM) 89- create U-Boot project (http://sourceforge.net/projects/u-boot) 90- current project page: see http://www.denx.de/wiki/U-Boot 91 92 93Names and Spelling: 94=================== 95 96The "official" name of this project is "Das U-Boot". The spelling 97"U-Boot" shall be used in all written text (documentation, comments 98in source files etc.). Example: 99 100 This is the README file for the U-Boot project. 101 102File names etc. shall be based on the string "u-boot". Examples: 103 104 include/asm-ppc/u-boot.h 105 106 #include <asm/u-boot.h> 107 108Variable names, preprocessor constants etc. shall be either based on 109the string "u_boot" or on "U_BOOT". Example: 110 111 U_BOOT_VERSION u_boot_logo 112 IH_OS_U_BOOT u_boot_hush_start 113 114 115Versioning: 116=========== 117 118Starting with the release in October 2008, the names of the releases 119were changed from numerical release numbers without deeper meaning 120into a time stamp based numbering. Regular releases are identified by 121names consisting of the calendar year and month of the release date. 122Additional fields (if present) indicate release candidates or bug fix 123releases in "stable" maintenance trees. 124 125Examples: 126 U-Boot v2009.11 - Release November 2009 127 U-Boot v2009.11.1 - Release 1 in version November 2009 stable tree 128 U-Boot v2010.09-rc1 - Release candiate 1 for September 2010 release 129 130 131Directory Hierarchy: 132==================== 133 134/arch Architecture specific files 135 /arm Files generic to ARM architecture 136 /cpu CPU specific files 137 /arm720t Files specific to ARM 720 CPUs 138 /arm920t Files specific to ARM 920 CPUs 139 /at91 Files specific to Atmel AT91RM9200 CPU 140 /imx Files specific to Freescale MC9328 i.MX CPUs 141 /s3c24x0 Files specific to Samsung S3C24X0 CPUs 142 /arm925t Files specific to ARM 925 CPUs 143 /arm926ejs Files specific to ARM 926 CPUs 144 /arm1136 Files specific to ARM 1136 CPUs 145 /ixp Files specific to Intel XScale IXP CPUs 146 /pxa Files specific to Intel XScale PXA CPUs 147 /s3c44b0 Files specific to Samsung S3C44B0 CPUs 148 /sa1100 Files specific to Intel StrongARM SA1100 CPUs 149 /lib Architecture specific library files 150 /avr32 Files generic to AVR32 architecture 151 /cpu CPU specific files 152 /lib Architecture specific library files 153 /blackfin Files generic to Analog Devices Blackfin architecture 154 /cpu CPU specific files 155 /lib Architecture specific library files 156 /x86 Files generic to x86 architecture 157 /cpu CPU specific files 158 /lib Architecture specific library files 159 /m68k Files generic to m68k architecture 160 /cpu CPU specific files 161 /mcf52x2 Files specific to Freescale ColdFire MCF52x2 CPUs 162 /mcf5227x Files specific to Freescale ColdFire MCF5227x CPUs 163 /mcf532x Files specific to Freescale ColdFire MCF5329 CPUs 164 /mcf5445x Files specific to Freescale ColdFire MCF5445x CPUs 165 /mcf547x_8x Files specific to Freescale ColdFire MCF547x_8x CPUs 166 /lib Architecture specific library files 167 /microblaze Files generic to microblaze architecture 168 /cpu CPU specific files 169 /lib Architecture specific library files 170 /mips Files generic to MIPS architecture 171 /cpu CPU specific files 172 /mips32 Files specific to MIPS32 CPUs 173 /xburst Files specific to Ingenic XBurst CPUs 174 /lib Architecture specific library files 175 /nds32 Files generic to NDS32 architecture 176 /cpu CPU specific files 177 /n1213 Files specific to Andes Technology N1213 CPUs 178 /lib Architecture specific library files 179 /nios2 Files generic to Altera NIOS2 architecture 180 /cpu CPU specific files 181 /lib Architecture specific library files 182 /powerpc Files generic to PowerPC architecture 183 /cpu CPU specific files 184 /74xx_7xx Files specific to Freescale MPC74xx and 7xx CPUs 185 /mpc5xx Files specific to Freescale MPC5xx CPUs 186 /mpc5xxx Files specific to Freescale MPC5xxx CPUs 187 /mpc8xx Files specific to Freescale MPC8xx CPUs 188 /mpc824x Files specific to Freescale MPC824x CPUs 189 /mpc8260 Files specific to Freescale MPC8260 CPUs 190 /mpc85xx Files specific to Freescale MPC85xx CPUs 191 /ppc4xx Files specific to AMCC PowerPC 4xx CPUs 192 /lib Architecture specific library files 193 /sh Files generic to SH architecture 194 /cpu CPU specific files 195 /sh2 Files specific to sh2 CPUs 196 /sh3 Files specific to sh3 CPUs 197 /sh4 Files specific to sh4 CPUs 198 /lib Architecture specific library files 199 /sparc Files generic to SPARC architecture 200 /cpu CPU specific files 201 /leon2 Files specific to Gaisler LEON2 SPARC CPU 202 /leon3 Files specific to Gaisler LEON3 SPARC CPU 203 /lib Architecture specific library files 204/api Machine/arch independent API for external apps 205/board Board dependent files 206/common Misc architecture independent functions 207/disk Code for disk drive partition handling 208/doc Documentation (don't expect too much) 209/drivers Commonly used device drivers 210/examples Example code for standalone applications, etc. 211/fs Filesystem code (cramfs, ext2, jffs2, etc.) 212/include Header Files 213/lib Files generic to all architectures 214 /libfdt Library files to support flattened device trees 215 /lzma Library files to support LZMA decompression 216 /lzo Library files to support LZO decompression 217/net Networking code 218/post Power On Self Test 219/rtc Real Time Clock drivers 220/tools Tools to build S-Record or U-Boot images, etc. 221 222Software Configuration: 223======================= 224 225Configuration is usually done using C preprocessor defines; the 226rationale behind that is to avoid dead code whenever possible. 227 228There are two classes of configuration variables: 229 230* Configuration _OPTIONS_: 231 These are selectable by the user and have names beginning with 232 "CONFIG_". 233 234* Configuration _SETTINGS_: 235 These depend on the hardware etc. and should not be meddled with if 236 you don't know what you're doing; they have names beginning with 237 "CONFIG_SYS_". 238 239Later we will add a configuration tool - probably similar to or even 240identical to what's used for the Linux kernel. Right now, we have to 241do the configuration by hand, which means creating some symbolic 242links and editing some configuration files. We use the TQM8xxL boards 243as an example here. 244 245 246Selection of Processor Architecture and Board Type: 247--------------------------------------------------- 248 249For all supported boards there are ready-to-use default 250configurations available; just type "make <board_name>_config". 251 252Example: For a TQM823L module type: 253 254 cd u-boot 255 make TQM823L_config 256 257For the Cogent platform, you need to specify the CPU type as well; 258e.g. "make cogent_mpc8xx_config". And also configure the cogent 259directory according to the instructions in cogent/README. 260 261 262Configuration Options: 263---------------------- 264 265Configuration depends on the combination of board and CPU type; all 266such information is kept in a configuration file 267"include/configs/<board_name>.h". 268 269Example: For a TQM823L module, all configuration settings are in 270"include/configs/TQM823L.h". 271 272 273Many of the options are named exactly as the corresponding Linux 274kernel configuration options. The intention is to make it easier to 275build a config tool - later. 276 277 278The following options need to be configured: 279 280- CPU Type: Define exactly one, e.g. CONFIG_MPC85XX. 281 282- Board Type: Define exactly one, e.g. CONFIG_MPC8540ADS. 283 284- CPU Daughterboard Type: (if CONFIG_ATSTK1000 is defined) 285 Define exactly one, e.g. CONFIG_ATSTK1002 286 287- CPU Module Type: (if CONFIG_COGENT is defined) 288 Define exactly one of 289 CONFIG_CMA286_60_OLD 290--- FIXME --- not tested yet: 291 CONFIG_CMA286_60, CONFIG_CMA286_21, CONFIG_CMA286_60P, 292 CONFIG_CMA287_23, CONFIG_CMA287_50 293 294- Motherboard Type: (if CONFIG_COGENT is defined) 295 Define exactly one of 296 CONFIG_CMA101, CONFIG_CMA102 297 298- Motherboard I/O Modules: (if CONFIG_COGENT is defined) 299 Define one or more of 300 CONFIG_CMA302 301 302- Motherboard Options: (if CONFIG_CMA101 or CONFIG_CMA102 are defined) 303 Define one or more of 304 CONFIG_LCD_HEARTBEAT - update a character position on 305 the LCD display every second with 306 a "rotator" |\-/|\-/ 307 308- Board flavour: (if CONFIG_MPC8260ADS is defined) 309 CONFIG_ADSTYPE 310 Possible values are: 311 CONFIG_SYS_8260ADS - original MPC8260ADS 312 CONFIG_SYS_8266ADS - MPC8266ADS 313 CONFIG_SYS_PQ2FADS - PQ2FADS-ZU or PQ2FADS-VR 314 CONFIG_SYS_8272ADS - MPC8272ADS 315 316- Marvell Family Member 317 CONFIG_SYS_MVFS - define it if you want to enable 318 multiple fs option at one time 319 for marvell soc family 320 321- MPC824X Family Member (if CONFIG_MPC824X is defined) 322 Define exactly one of 323 CONFIG_MPC8240, CONFIG_MPC8245 324 325- 8xx CPU Options: (if using an MPC8xx CPU) 326 CONFIG_8xx_GCLK_FREQ - deprecated: CPU clock if 327 get_gclk_freq() cannot work 328 e.g. if there is no 32KHz 329 reference PIT/RTC clock 330 CONFIG_8xx_OSCLK - PLL input clock (either EXTCLK 331 or XTAL/EXTAL) 332 333- 859/866/885 CPU options: (if using a MPC859 or MPC866 or MPC885 CPU): 334 CONFIG_SYS_8xx_CPUCLK_MIN 335 CONFIG_SYS_8xx_CPUCLK_MAX 336 CONFIG_8xx_CPUCLK_DEFAULT 337 See doc/README.MPC866 338 339 CONFIG_SYS_MEASURE_CPUCLK 340 341 Define this to measure the actual CPU clock instead 342 of relying on the correctness of the configured 343 values. Mostly useful for board bringup to make sure 344 the PLL is locked at the intended frequency. Note 345 that this requires a (stable) reference clock (32 kHz 346 RTC clock or CONFIG_SYS_8XX_XIN) 347 348 CONFIG_SYS_DELAYED_ICACHE 349 350 Define this option if you want to enable the 351 ICache only when Code runs from RAM. 352 353- 85xx CPU Options: 354 CONFIG_SYS_PPC64 355 356 Specifies that the core is a 64-bit PowerPC implementation (implements 357 the "64" category of the Power ISA). This is necessary for ePAPR 358 compliance, among other possible reasons. 359 360 CONFIG_SYS_FSL_TBCLK_DIV 361 362 Defines the core time base clock divider ratio compared to the 363 system clock. On most PQ3 devices this is 8, on newer QorIQ 364 devices it can be 16 or 32. The ratio varies from SoC to Soc. 365 366 CONFIG_SYS_FSL_PCIE_COMPAT 367 368 Defines the string to utilize when trying to match PCIe device 369 tree nodes for the given platform. 370 371 CONFIG_SYS_PPC_E500_DEBUG_TLB 372 373 Enables a temporary TLB entry to be used during boot to work 374 around limitations in e500v1 and e500v2 external debugger 375 support. This reduces the portions of the boot code where 376 breakpoints and single stepping do not work. The value of this 377 symbol should be set to the TLB1 entry to be used for this 378 purpose. 379 380 CONFIG_SYS_FSL_ERRATUM_A004510 381 382 Enables a workaround for erratum A004510. If set, 383 then CONFIG_SYS_FSL_ERRATUM_A004510_SVR_REV and 384 CONFIG_SYS_FSL_CORENET_SNOOPVEC_COREONLY must be set. 385 386 CONFIG_SYS_FSL_ERRATUM_A004510_SVR_REV 387 CONFIG_SYS_FSL_ERRATUM_A004510_SVR_REV2 (optional) 388 389 Defines one or two SoC revisions (low 8 bits of SVR) 390 for which the A004510 workaround should be applied. 391 392 The rest of SVR is either not relevant to the decision 393 of whether the erratum is present (e.g. p2040 versus 394 p2041) or is implied by the build target, which controls 395 whether CONFIG_SYS_FSL_ERRATUM_A004510 is set. 396 397 See Freescale App Note 4493 for more information about 398 this erratum. 399 400 CONFIG_A003399_NOR_WORKAROUND 401 Enables a workaround for IFC erratum A003399. It is only 402 requred during NOR boot. 403 404 CONFIG_SYS_FSL_CORENET_SNOOPVEC_COREONLY 405 406 This is the value to write into CCSR offset 0x18600 407 according to the A004510 workaround. 408 409 CONFIG_SYS_FSL_DSP_DDR_ADDR 410 This value denotes start offset of DDR memory which is 411 connected exclusively to the DSP cores. 412 413 CONFIG_SYS_FSL_DSP_M2_RAM_ADDR 414 This value denotes start offset of M2 memory 415 which is directly connected to the DSP core. 416 417 CONFIG_SYS_FSL_DSP_M3_RAM_ADDR 418 This value denotes start offset of M3 memory which is directly 419 connected to the DSP core. 420 421 CONFIG_SYS_FSL_DSP_CCSRBAR_DEFAULT 422 This value denotes start offset of DSP CCSR space. 423 424 CONFIG_SYS_FSL_DDR_EMU 425 Specify emulator support for DDR. Some DDR features such as 426 deskew training are not available. 427 428- Generic CPU options: 429 CONFIG_SYS_BIG_ENDIAN, CONFIG_SYS_LITTLE_ENDIAN 430 431 Defines the endianess of the CPU. Implementation of those 432 values is arch specific. 433 434- Intel Monahans options: 435 CONFIG_SYS_MONAHANS_RUN_MODE_OSC_RATIO 436 437 Defines the Monahans run mode to oscillator 438 ratio. Valid values are 8, 16, 24, 31. The core 439 frequency is this value multiplied by 13 MHz. 440 441 CONFIG_SYS_MONAHANS_TURBO_RUN_MODE_RATIO 442 443 Defines the Monahans turbo mode to oscillator 444 ratio. Valid values are 1 (default if undefined) and 445 2. The core frequency as calculated above is multiplied 446 by this value. 447 448- MIPS CPU options: 449 CONFIG_SYS_INIT_SP_OFFSET 450 451 Offset relative to CONFIG_SYS_SDRAM_BASE for initial stack 452 pointer. This is needed for the temporary stack before 453 relocation. 454 455 CONFIG_SYS_MIPS_CACHE_MODE 456 457 Cache operation mode for the MIPS CPU. 458 See also arch/mips/include/asm/mipsregs.h. 459 Possible values are: 460 CONF_CM_CACHABLE_NO_WA 461 CONF_CM_CACHABLE_WA 462 CONF_CM_UNCACHED 463 CONF_CM_CACHABLE_NONCOHERENT 464 CONF_CM_CACHABLE_CE 465 CONF_CM_CACHABLE_COW 466 CONF_CM_CACHABLE_CUW 467 CONF_CM_CACHABLE_ACCELERATED 468 469 CONFIG_SYS_XWAY_EBU_BOOTCFG 470 471 Special option for Lantiq XWAY SoCs for booting from NOR flash. 472 See also arch/mips/cpu/mips32/start.S. 473 474 CONFIG_XWAY_SWAP_BYTES 475 476 Enable compilation of tools/xway-swap-bytes needed for Lantiq 477 XWAY SoCs for booting from NOR flash. The U-Boot image needs to 478 be swapped if a flash programmer is used. 479 480- ARM options: 481 CONFIG_SYS_EXCEPTION_VECTORS_HIGH 482 483 Select high exception vectors of the ARM core, e.g., do not 484 clear the V bit of the c1 register of CP15. 485 486 CONFIG_SYS_THUMB_BUILD 487 488 Use this flag to build U-Boot using the Thumb instruction 489 set for ARM architectures. Thumb instruction set provides 490 better code density. For ARM architectures that support 491 Thumb2 this flag will result in Thumb2 code generated by 492 GCC. 493 494 CONFIG_ARM_ERRATA_716044 495 CONFIG_ARM_ERRATA_742230 496 CONFIG_ARM_ERRATA_743622 497 CONFIG_ARM_ERRATA_751472 498 499 If set, the workarounds for these ARM errata are applied early 500 during U-Boot startup. Note that these options force the 501 workarounds to be applied; no CPU-type/version detection 502 exists, unlike the similar options in the Linux kernel. Do not 503 set these options unless they apply! 504 505- CPU timer options: 506 CONFIG_SYS_HZ 507 508 The frequency of the timer returned by get_timer(). 509 get_timer() must operate in milliseconds and this CONFIG 510 option must be set to 1000. 511 512- Linux Kernel Interface: 513 CONFIG_CLOCKS_IN_MHZ 514 515 U-Boot stores all clock information in Hz 516 internally. For binary compatibility with older Linux 517 kernels (which expect the clocks passed in the 518 bd_info data to be in MHz) the environment variable 519 "clocks_in_mhz" can be defined so that U-Boot 520 converts clock data to MHZ before passing it to the 521 Linux kernel. 522 When CONFIG_CLOCKS_IN_MHZ is defined, a definition of 523 "clocks_in_mhz=1" is automatically included in the 524 default environment. 525 526 CONFIG_MEMSIZE_IN_BYTES [relevant for MIPS only] 527 528 When transferring memsize parameter to linux, some versions 529 expect it to be in bytes, others in MB. 530 Define CONFIG_MEMSIZE_IN_BYTES to make it in bytes. 531 532 CONFIG_OF_LIBFDT 533 534 New kernel versions are expecting firmware settings to be 535 passed using flattened device trees (based on open firmware 536 concepts). 537 538 CONFIG_OF_LIBFDT 539 * New libfdt-based support 540 * Adds the "fdt" command 541 * The bootm command automatically updates the fdt 542 543 OF_CPU - The proper name of the cpus node (only required for 544 MPC512X and MPC5xxx based boards). 545 OF_SOC - The proper name of the soc node (only required for 546 MPC512X and MPC5xxx based boards). 547 OF_TBCLK - The timebase frequency. 548 OF_STDOUT_PATH - The path to the console device 549 550 boards with QUICC Engines require OF_QE to set UCC MAC 551 addresses 552 553 CONFIG_OF_BOARD_SETUP 554 555 Board code has addition modification that it wants to make 556 to the flat device tree before handing it off to the kernel 557 558 CONFIG_OF_BOOT_CPU 559 560 This define fills in the correct boot CPU in the boot 561 param header, the default value is zero if undefined. 562 563 CONFIG_OF_IDE_FIXUP 564 565 U-Boot can detect if an IDE device is present or not. 566 If not, and this new config option is activated, U-Boot 567 removes the ATA node from the DTS before booting Linux, 568 so the Linux IDE driver does not probe the device and 569 crash. This is needed for buggy hardware (uc101) where 570 no pull down resistor is connected to the signal IDE5V_DD7. 571 572 CONFIG_MACH_TYPE [relevant for ARM only][mandatory] 573 574 This setting is mandatory for all boards that have only one 575 machine type and must be used to specify the machine type 576 number as it appears in the ARM machine registry 577 (see http://www.arm.linux.org.uk/developer/machines/). 578 Only boards that have multiple machine types supported 579 in a single configuration file and the machine type is 580 runtime discoverable, do not have to use this setting. 581 582- vxWorks boot parameters: 583 584 bootvx constructs a valid bootline using the following 585 environments variables: bootfile, ipaddr, serverip, hostname. 586 It loads the vxWorks image pointed bootfile. 587 588 CONFIG_SYS_VXWORKS_BOOT_DEVICE - The vxworks device name 589 CONFIG_SYS_VXWORKS_MAC_PTR - Ethernet 6 byte MA -address 590 CONFIG_SYS_VXWORKS_SERVERNAME - Name of the server 591 CONFIG_SYS_VXWORKS_BOOT_ADDR - Address of boot parameters 592 593 CONFIG_SYS_VXWORKS_ADD_PARAMS 594 595 Add it at the end of the bootline. E.g "u=username pw=secret" 596 597 Note: If a "bootargs" environment is defined, it will overwride 598 the defaults discussed just above. 599 600- Cache Configuration: 601 CONFIG_SYS_ICACHE_OFF - Do not enable instruction cache in U-Boot 602 CONFIG_SYS_DCACHE_OFF - Do not enable data cache in U-Boot 603 CONFIG_SYS_L2CACHE_OFF- Do not enable L2 cache in U-Boot 604 605- Cache Configuration for ARM: 606 CONFIG_SYS_L2_PL310 - Enable support for ARM PL310 L2 cache 607 controller 608 CONFIG_SYS_PL310_BASE - Physical base address of PL310 609 controller register space 610 611- Serial Ports: 612 CONFIG_PL010_SERIAL 613 614 Define this if you want support for Amba PrimeCell PL010 UARTs. 615 616 CONFIG_PL011_SERIAL 617 618 Define this if you want support for Amba PrimeCell PL011 UARTs. 619 620 CONFIG_PL011_CLOCK 621 622 If you have Amba PrimeCell PL011 UARTs, set this variable to 623 the clock speed of the UARTs. 624 625 CONFIG_PL01x_PORTS 626 627 If you have Amba PrimeCell PL010 or PL011 UARTs on your board, 628 define this to a list of base addresses for each (supported) 629 port. See e.g. include/configs/versatile.h 630 631 CONFIG_PL011_SERIAL_RLCR 632 633 Some vendor versions of PL011 serial ports (e.g. ST-Ericsson U8500) 634 have separate receive and transmit line control registers. Set 635 this variable to initialize the extra register. 636 637 CONFIG_PL011_SERIAL_FLUSH_ON_INIT 638 639 On some platforms (e.g. U8500) U-Boot is loaded by a second stage 640 boot loader that has already initialized the UART. Define this 641 variable to flush the UART at init time. 642 643 644- Console Interface: 645 Depending on board, define exactly one serial port 646 (like CONFIG_8xx_CONS_SMC1, CONFIG_8xx_CONS_SMC2, 647 CONFIG_8xx_CONS_SCC1, ...), or switch off the serial 648 console by defining CONFIG_8xx_CONS_NONE 649 650 Note: if CONFIG_8xx_CONS_NONE is defined, the serial 651 port routines must be defined elsewhere 652 (i.e. serial_init(), serial_getc(), ...) 653 654 CONFIG_CFB_CONSOLE 655 Enables console device for a color framebuffer. Needs following 656 defines (cf. smiLynxEM, i8042) 657 VIDEO_FB_LITTLE_ENDIAN graphic memory organisation 658 (default big endian) 659 VIDEO_HW_RECTFILL graphic chip supports 660 rectangle fill 661 (cf. smiLynxEM) 662 VIDEO_HW_BITBLT graphic chip supports 663 bit-blit (cf. smiLynxEM) 664 VIDEO_VISIBLE_COLS visible pixel columns 665 (cols=pitch) 666 VIDEO_VISIBLE_ROWS visible pixel rows 667 VIDEO_PIXEL_SIZE bytes per pixel 668 VIDEO_DATA_FORMAT graphic data format 669 (0-5, cf. cfb_console.c) 670 VIDEO_FB_ADRS framebuffer address 671 VIDEO_KBD_INIT_FCT keyboard int fct 672 (i.e. i8042_kbd_init()) 673 VIDEO_TSTC_FCT test char fct 674 (i.e. i8042_tstc) 675 VIDEO_GETC_FCT get char fct 676 (i.e. i8042_getc) 677 CONFIG_CONSOLE_CURSOR cursor drawing on/off 678 (requires blink timer 679 cf. i8042.c) 680 CONFIG_SYS_CONSOLE_BLINK_COUNT blink interval (cf. i8042.c) 681 CONFIG_CONSOLE_TIME display time/date info in 682 upper right corner 683 (requires CONFIG_CMD_DATE) 684 CONFIG_VIDEO_LOGO display Linux logo in 685 upper left corner 686 CONFIG_VIDEO_BMP_LOGO use bmp_logo.h instead of 687 linux_logo.h for logo. 688 Requires CONFIG_VIDEO_LOGO 689 CONFIG_CONSOLE_EXTRA_INFO 690 additional board info beside 691 the logo 692 693 When CONFIG_CFB_CONSOLE_ANSI is defined, console will support 694 a limited number of ANSI escape sequences (cursor control, 695 erase functions and limited graphics rendition control). 696 697 When CONFIG_CFB_CONSOLE is defined, video console is 698 default i/o. Serial console can be forced with 699 environment 'console=serial'. 700 701 When CONFIG_SILENT_CONSOLE is defined, all console 702 messages (by U-Boot and Linux!) can be silenced with 703 the "silent" environment variable. See 704 doc/README.silent for more information. 705 706- Console Baudrate: 707 CONFIG_BAUDRATE - in bps 708 Select one of the baudrates listed in 709 CONFIG_SYS_BAUDRATE_TABLE, see below. 710 CONFIG_SYS_BRGCLK_PRESCALE, baudrate prescale 711 712- Console Rx buffer length 713 With CONFIG_SYS_SMC_RXBUFLEN it is possible to define 714 the maximum receive buffer length for the SMC. 715 This option is actual only for 82xx and 8xx possible. 716 If using CONFIG_SYS_SMC_RXBUFLEN also CONFIG_SYS_MAXIDLE 717 must be defined, to setup the maximum idle timeout for 718 the SMC. 719 720- Pre-Console Buffer: 721 Prior to the console being initialised (i.e. serial UART 722 initialised etc) all console output is silently discarded. 723 Defining CONFIG_PRE_CONSOLE_BUFFER will cause U-Boot to 724 buffer any console messages prior to the console being 725 initialised to a buffer of size CONFIG_PRE_CON_BUF_SZ 726 bytes located at CONFIG_PRE_CON_BUF_ADDR. The buffer is 727 a circular buffer, so if more than CONFIG_PRE_CON_BUF_SZ 728 bytes are output before the console is initialised, the 729 earlier bytes are discarded. 730 731 'Sane' compilers will generate smaller code if 732 CONFIG_PRE_CON_BUF_SZ is a power of 2 733 734- Safe printf() functions 735 Define CONFIG_SYS_VSNPRINTF to compile in safe versions of 736 the printf() functions. These are defined in 737 include/vsprintf.h and include snprintf(), vsnprintf() and 738 so on. Code size increase is approximately 300-500 bytes. 739 If this option is not given then these functions will 740 silently discard their buffer size argument - this means 741 you are not getting any overflow checking in this case. 742 743- Boot Delay: CONFIG_BOOTDELAY - in seconds 744 Delay before automatically booting the default image; 745 set to -1 to disable autoboot. 746 set to -2 to autoboot with no delay and not check for abort 747 (even when CONFIG_ZERO_BOOTDELAY_CHECK is defined). 748 749 See doc/README.autoboot for these options that 750 work with CONFIG_BOOTDELAY. None are required. 751 CONFIG_BOOT_RETRY_TIME 752 CONFIG_BOOT_RETRY_MIN 753 CONFIG_AUTOBOOT_KEYED 754 CONFIG_AUTOBOOT_PROMPT 755 CONFIG_AUTOBOOT_DELAY_STR 756 CONFIG_AUTOBOOT_STOP_STR 757 CONFIG_AUTOBOOT_DELAY_STR2 758 CONFIG_AUTOBOOT_STOP_STR2 759 CONFIG_ZERO_BOOTDELAY_CHECK 760 CONFIG_RESET_TO_RETRY 761 762- Autoboot Command: 763 CONFIG_BOOTCOMMAND 764 Only needed when CONFIG_BOOTDELAY is enabled; 765 define a command string that is automatically executed 766 when no character is read on the console interface 767 within "Boot Delay" after reset. 768 769 CONFIG_BOOTARGS 770 This can be used to pass arguments to the bootm 771 command. The value of CONFIG_BOOTARGS goes into the 772 environment value "bootargs". 773 774 CONFIG_RAMBOOT and CONFIG_NFSBOOT 775 The value of these goes into the environment as 776 "ramboot" and "nfsboot" respectively, and can be used 777 as a convenience, when switching between booting from 778 RAM and NFS. 779 780- Pre-Boot Commands: 781 CONFIG_PREBOOT 782 783 When this option is #defined, the existence of the 784 environment variable "preboot" will be checked 785 immediately before starting the CONFIG_BOOTDELAY 786 countdown and/or running the auto-boot command resp. 787 entering interactive mode. 788 789 This feature is especially useful when "preboot" is 790 automatically generated or modified. For an example 791 see the LWMON board specific code: here "preboot" is 792 modified when the user holds down a certain 793 combination of keys on the (special) keyboard when 794 booting the systems 795 796- Serial Download Echo Mode: 797 CONFIG_LOADS_ECHO 798 If defined to 1, all characters received during a 799 serial download (using the "loads" command) are 800 echoed back. This might be needed by some terminal 801 emulations (like "cu"), but may as well just take 802 time on others. This setting #define's the initial 803 value of the "loads_echo" environment variable. 804 805- Kgdb Serial Baudrate: (if CONFIG_CMD_KGDB is defined) 806 CONFIG_KGDB_BAUDRATE 807 Select one of the baudrates listed in 808 CONFIG_SYS_BAUDRATE_TABLE, see below. 809 810- Monitor Functions: 811 Monitor commands can be included or excluded 812 from the build by using the #include files 813 <config_cmd_all.h> and #undef'ing unwanted 814 commands, or using <config_cmd_default.h> 815 and augmenting with additional #define's 816 for wanted commands. 817 818 The default command configuration includes all commands 819 except those marked below with a "*". 820 821 CONFIG_CMD_ASKENV * ask for env variable 822 CONFIG_CMD_BDI bdinfo 823 CONFIG_CMD_BEDBUG * Include BedBug Debugger 824 CONFIG_CMD_BMP * BMP support 825 CONFIG_CMD_BSP * Board specific commands 826 CONFIG_CMD_BOOTD bootd 827 CONFIG_CMD_CACHE * icache, dcache 828 CONFIG_CMD_CONSOLE coninfo 829 CONFIG_CMD_CRC32 * crc32 830 CONFIG_CMD_DATE * support for RTC, date/time... 831 CONFIG_CMD_DHCP * DHCP support 832 CONFIG_CMD_DIAG * Diagnostics 833 CONFIG_CMD_DS4510 * ds4510 I2C gpio commands 834 CONFIG_CMD_DS4510_INFO * ds4510 I2C info command 835 CONFIG_CMD_DS4510_MEM * ds4510 I2C eeprom/sram commansd 836 CONFIG_CMD_DS4510_RST * ds4510 I2C rst command 837 CONFIG_CMD_DTT * Digital Therm and Thermostat 838 CONFIG_CMD_ECHO echo arguments 839 CONFIG_CMD_EDITENV edit env variable 840 CONFIG_CMD_EEPROM * EEPROM read/write support 841 CONFIG_CMD_ELF * bootelf, bootvx 842 CONFIG_CMD_ENV_CALLBACK * display details about env callbacks 843 CONFIG_CMD_ENV_FLAGS * display details about env flags 844 CONFIG_CMD_EXPORTENV * export the environment 845 CONFIG_CMD_EXT2 * ext2 command support 846 CONFIG_CMD_EXT4 * ext4 command support 847 CONFIG_CMD_SAVEENV saveenv 848 CONFIG_CMD_FDC * Floppy Disk Support 849 CONFIG_CMD_FAT * FAT command support 850 CONFIG_CMD_FDOS * Dos diskette Support 851 CONFIG_CMD_FLASH flinfo, erase, protect 852 CONFIG_CMD_FPGA FPGA device initialization support 853 CONFIG_CMD_FUSE * Device fuse support 854 CONFIG_CMD_GETTIME * Get time since boot 855 CONFIG_CMD_GO * the 'go' command (exec code) 856 CONFIG_CMD_GREPENV * search environment 857 CONFIG_CMD_HASH * calculate hash / digest 858 CONFIG_CMD_HWFLOW * RTS/CTS hw flow control 859 CONFIG_CMD_I2C * I2C serial bus support 860 CONFIG_CMD_IDE * IDE harddisk support 861 CONFIG_CMD_IMI iminfo 862 CONFIG_CMD_IMLS List all images found in NOR flash 863 CONFIG_CMD_IMLS_NAND * List all images found in NAND flash 864 CONFIG_CMD_IMMAP * IMMR dump support 865 CONFIG_CMD_IMPORTENV * import an environment 866 CONFIG_CMD_INI * import data from an ini file into the env 867 CONFIG_CMD_IRQ * irqinfo 868 CONFIG_CMD_ITEST Integer/string test of 2 values 869 CONFIG_CMD_JFFS2 * JFFS2 Support 870 CONFIG_CMD_KGDB * kgdb 871 CONFIG_CMD_LDRINFO * ldrinfo (display Blackfin loader) 872 CONFIG_CMD_LINK_LOCAL * link-local IP address auto-configuration 873 (169.254.*.*) 874 CONFIG_CMD_LOADB loadb 875 CONFIG_CMD_LOADS loads 876 CONFIG_CMD_MD5SUM * print md5 message digest 877 (requires CONFIG_CMD_MEMORY and CONFIG_MD5) 878 CONFIG_CMD_MEMINFO * Display detailed memory information 879 CONFIG_CMD_MEMORY md, mm, nm, mw, cp, cmp, crc, base, 880 loop, loopw 881 CONFIG_CMD_MEMTEST * mtest 882 CONFIG_CMD_MISC Misc functions like sleep etc 883 CONFIG_CMD_MMC * MMC memory mapped support 884 CONFIG_CMD_MII * MII utility commands 885 CONFIG_CMD_MTDPARTS * MTD partition support 886 CONFIG_CMD_NAND * NAND support 887 CONFIG_CMD_NET bootp, tftpboot, rarpboot 888 CONFIG_CMD_NFS NFS support 889 CONFIG_CMD_PCA953X * PCA953x I2C gpio commands 890 CONFIG_CMD_PCA953X_INFO * PCA953x I2C gpio info command 891 CONFIG_CMD_PCI * pciinfo 892 CONFIG_CMD_PCMCIA * PCMCIA support 893 CONFIG_CMD_PING * send ICMP ECHO_REQUEST to network 894 host 895 CONFIG_CMD_PORTIO * Port I/O 896 CONFIG_CMD_READ * Read raw data from partition 897 CONFIG_CMD_REGINFO * Register dump 898 CONFIG_CMD_RUN run command in env variable 899 CONFIG_CMD_SANDBOX * sb command to access sandbox features 900 CONFIG_CMD_SAVES * save S record dump 901 CONFIG_CMD_SCSI * SCSI Support 902 CONFIG_CMD_SDRAM * print SDRAM configuration information 903 (requires CONFIG_CMD_I2C) 904 CONFIG_CMD_SETGETDCR Support for DCR Register access 905 (4xx only) 906 CONFIG_CMD_SF * Read/write/erase SPI NOR flash 907 CONFIG_CMD_SHA1SUM * print sha1 memory digest 908 (requires CONFIG_CMD_MEMORY) 909 CONFIG_CMD_SOFTSWITCH * Soft switch setting command for BF60x 910 CONFIG_CMD_SOURCE "source" command Support 911 CONFIG_CMD_SPI * SPI serial bus support 912 CONFIG_CMD_TFTPSRV * TFTP transfer in server mode 913 CONFIG_CMD_TFTPPUT * TFTP put command (upload) 914 CONFIG_CMD_TIME * run command and report execution time (ARM specific) 915 CONFIG_CMD_TIMER * access to the system tick timer 916 CONFIG_CMD_USB * USB support 917 CONFIG_CMD_CDP * Cisco Discover Protocol support 918 CONFIG_CMD_MFSL * Microblaze FSL support 919 CONFIG_CMD_XIMG Load part of Multi Image 920 921 922 EXAMPLE: If you want all functions except of network 923 support you can write: 924 925 #include "config_cmd_all.h" 926 #undef CONFIG_CMD_NET 927 928 Other Commands: 929 fdt (flattened device tree) command: CONFIG_OF_LIBFDT 930 931 Note: Don't enable the "icache" and "dcache" commands 932 (configuration option CONFIG_CMD_CACHE) unless you know 933 what you (and your U-Boot users) are doing. Data 934 cache cannot be enabled on systems like the 8xx or 935 8260 (where accesses to the IMMR region must be 936 uncached), and it cannot be disabled on all other 937 systems where we (mis-) use the data cache to hold an 938 initial stack and some data. 939 940 941 XXX - this list needs to get updated! 942 943- Regular expression support: 944 CONFIG_REGEX 945 If this variable is defined, U-Boot is linked against 946 the SLRE (Super Light Regular Expression) library, 947 which adds regex support to some commands, as for 948 example "env grep" and "setexpr". 949 950- Device tree: 951 CONFIG_OF_CONTROL 952 If this variable is defined, U-Boot will use a device tree 953 to configure its devices, instead of relying on statically 954 compiled #defines in the board file. This option is 955 experimental and only available on a few boards. The device 956 tree is available in the global data as gd->fdt_blob. 957 958 U-Boot needs to get its device tree from somewhere. This can 959 be done using one of the two options below: 960 961 CONFIG_OF_EMBED 962 If this variable is defined, U-Boot will embed a device tree 963 binary in its image. This device tree file should be in the 964 board directory and called <soc>-<board>.dts. The binary file 965 is then picked up in board_init_f() and made available through 966 the global data structure as gd->blob. 967 968 CONFIG_OF_SEPARATE 969 If this variable is defined, U-Boot will build a device tree 970 binary. It will be called u-boot.dtb. Architecture-specific 971 code will locate it at run-time. Generally this works by: 972 973 cat u-boot.bin u-boot.dtb >image.bin 974 975 and in fact, U-Boot does this for you, creating a file called 976 u-boot-dtb.bin which is useful in the common case. You can 977 still use the individual files if you need something more 978 exotic. 979 980- Watchdog: 981 CONFIG_WATCHDOG 982 If this variable is defined, it enables watchdog 983 support for the SoC. There must be support in the SoC 984 specific code for a watchdog. For the 8xx and 8260 985 CPUs, the SIU Watchdog feature is enabled in the SYPCR 986 register. When supported for a specific SoC is 987 available, then no further board specific code should 988 be needed to use it. 989 990 CONFIG_HW_WATCHDOG 991 When using a watchdog circuitry external to the used 992 SoC, then define this variable and provide board 993 specific code for the "hw_watchdog_reset" function. 994 995- U-Boot Version: 996 CONFIG_VERSION_VARIABLE 997 If this variable is defined, an environment variable 998 named "ver" is created by U-Boot showing the U-Boot 999 version as printed by the "version" command. 1000 Any change to this variable will be reverted at the 1001 next reset. 1002 1003- Real-Time Clock: 1004 1005 When CONFIG_CMD_DATE is selected, the type of the RTC 1006 has to be selected, too. Define exactly one of the 1007 following options: 1008 1009 CONFIG_RTC_MPC8xx - use internal RTC of MPC8xx 1010 CONFIG_RTC_PCF8563 - use Philips PCF8563 RTC 1011 CONFIG_RTC_MC13XXX - use MC13783 or MC13892 RTC 1012 CONFIG_RTC_MC146818 - use MC146818 RTC 1013 CONFIG_RTC_DS1307 - use Maxim, Inc. DS1307 RTC 1014 CONFIG_RTC_DS1337 - use Maxim, Inc. DS1337 RTC 1015 CONFIG_RTC_DS1338 - use Maxim, Inc. DS1338 RTC 1016 CONFIG_RTC_DS164x - use Dallas DS164x RTC 1017 CONFIG_RTC_ISL1208 - use Intersil ISL1208 RTC 1018 CONFIG_RTC_MAX6900 - use Maxim, Inc. MAX6900 RTC 1019 CONFIG_SYS_RTC_DS1337_NOOSC - Turn off the OSC output for DS1337 1020 CONFIG_SYS_RV3029_TCR - enable trickle charger on 1021 RV3029 RTC. 1022 1023 Note that if the RTC uses I2C, then the I2C interface 1024 must also be configured. See I2C Support, below. 1025 1026- GPIO Support: 1027 CONFIG_PCA953X - use NXP's PCA953X series I2C GPIO 1028 CONFIG_PCA953X_INFO - enable pca953x info command 1029 1030 The CONFIG_SYS_I2C_PCA953X_WIDTH option specifies a list of 1031 chip-ngpio pairs that tell the PCA953X driver the number of 1032 pins supported by a particular chip. 1033 1034 Note that if the GPIO device uses I2C, then the I2C interface 1035 must also be configured. See I2C Support, below. 1036 1037- Timestamp Support: 1038 1039 When CONFIG_TIMESTAMP is selected, the timestamp 1040 (date and time) of an image is printed by image 1041 commands like bootm or iminfo. This option is 1042 automatically enabled when you select CONFIG_CMD_DATE . 1043 1044- Partition Labels (disklabels) Supported: 1045 Zero or more of the following: 1046 CONFIG_MAC_PARTITION Apple's MacOS partition table. 1047 CONFIG_DOS_PARTITION MS Dos partition table, traditional on the 1048 Intel architecture, USB sticks, etc. 1049 CONFIG_ISO_PARTITION ISO partition table, used on CDROM etc. 1050 CONFIG_EFI_PARTITION GPT partition table, common when EFI is the 1051 bootloader. Note 2TB partition limit; see 1052 disk/part_efi.c 1053 CONFIG_MTD_PARTITIONS Memory Technology Device partition table. 1054 1055 If IDE or SCSI support is enabled (CONFIG_CMD_IDE or 1056 CONFIG_CMD_SCSI) you must configure support for at 1057 least one non-MTD partition type as well. 1058 1059- IDE Reset method: 1060 CONFIG_IDE_RESET_ROUTINE - this is defined in several 1061 board configurations files but used nowhere! 1062 1063 CONFIG_IDE_RESET - is this is defined, IDE Reset will 1064 be performed by calling the function 1065 ide_set_reset(int reset) 1066 which has to be defined in a board specific file 1067 1068- ATAPI Support: 1069 CONFIG_ATAPI 1070 1071 Set this to enable ATAPI support. 1072 1073- LBA48 Support 1074 CONFIG_LBA48 1075 1076 Set this to enable support for disks larger than 137GB 1077 Also look at CONFIG_SYS_64BIT_LBA. 1078 Whithout these , LBA48 support uses 32bit variables and will 'only' 1079 support disks up to 2.1TB. 1080 1081 CONFIG_SYS_64BIT_LBA: 1082 When enabled, makes the IDE subsystem use 64bit sector addresses. 1083 Default is 32bit. 1084 1085- SCSI Support: 1086 At the moment only there is only support for the 1087 SYM53C8XX SCSI controller; define 1088 CONFIG_SCSI_SYM53C8XX to enable it. 1089 1090 CONFIG_SYS_SCSI_MAX_LUN [8], CONFIG_SYS_SCSI_MAX_SCSI_ID [7] and 1091 CONFIG_SYS_SCSI_MAX_DEVICE [CONFIG_SYS_SCSI_MAX_SCSI_ID * 1092 CONFIG_SYS_SCSI_MAX_LUN] can be adjusted to define the 1093 maximum numbers of LUNs, SCSI ID's and target 1094 devices. 1095 CONFIG_SYS_SCSI_SYM53C8XX_CCF to fix clock timing (80Mhz) 1096 1097 The environment variable 'scsidevs' is set to the number of 1098 SCSI devices found during the last scan. 1099 1100- NETWORK Support (PCI): 1101 CONFIG_E1000 1102 Support for Intel 8254x/8257x gigabit chips. 1103 1104 CONFIG_E1000_SPI 1105 Utility code for direct access to the SPI bus on Intel 8257x. 1106 This does not do anything useful unless you set at least one 1107 of CONFIG_CMD_E1000 or CONFIG_E1000_SPI_GENERIC. 1108 1109 CONFIG_E1000_SPI_GENERIC 1110 Allow generic access to the SPI bus on the Intel 8257x, for 1111 example with the "sspi" command. 1112 1113 CONFIG_CMD_E1000 1114 Management command for E1000 devices. When used on devices 1115 with SPI support you can reprogram the EEPROM from U-Boot. 1116 1117 CONFIG_E1000_FALLBACK_MAC 1118 default MAC for empty EEPROM after production. 1119 1120 CONFIG_EEPRO100 1121 Support for Intel 82557/82559/82559ER chips. 1122 Optional CONFIG_EEPRO100_SROM_WRITE enables EEPROM 1123 write routine for first time initialisation. 1124 1125 CONFIG_TULIP 1126 Support for Digital 2114x chips. 1127 Optional CONFIG_TULIP_SELECT_MEDIA for board specific 1128 modem chip initialisation (KS8761/QS6611). 1129 1130 CONFIG_NATSEMI 1131 Support for National dp83815 chips. 1132 1133 CONFIG_NS8382X 1134 Support for National dp8382[01] gigabit chips. 1135 1136- NETWORK Support (other): 1137 1138 CONFIG_DRIVER_AT91EMAC 1139 Support for AT91RM9200 EMAC. 1140 1141 CONFIG_RMII 1142 Define this to use reduced MII inteface 1143 1144 CONFIG_DRIVER_AT91EMAC_QUIET 1145 If this defined, the driver is quiet. 1146 The driver doen't show link status messages. 1147 1148 CONFIG_CALXEDA_XGMAC 1149 Support for the Calxeda XGMAC device 1150 1151 CONFIG_LAN91C96 1152 Support for SMSC's LAN91C96 chips. 1153 1154 CONFIG_LAN91C96_BASE 1155 Define this to hold the physical address 1156 of the LAN91C96's I/O space 1157 1158 CONFIG_LAN91C96_USE_32_BIT 1159 Define this to enable 32 bit addressing 1160 1161 CONFIG_SMC91111 1162 Support for SMSC's LAN91C111 chip 1163 1164 CONFIG_SMC91111_BASE 1165 Define this to hold the physical address 1166 of the device (I/O space) 1167 1168 CONFIG_SMC_USE_32_BIT 1169 Define this if data bus is 32 bits 1170 1171 CONFIG_SMC_USE_IOFUNCS 1172 Define this to use i/o functions instead of macros 1173 (some hardware wont work with macros) 1174 1175 CONFIG_DRIVER_TI_EMAC 1176 Support for davinci emac 1177 1178 CONFIG_SYS_DAVINCI_EMAC_PHY_COUNT 1179 Define this if you have more then 3 PHYs. 1180 1181 CONFIG_FTGMAC100 1182 Support for Faraday's FTGMAC100 Gigabit SoC Ethernet 1183 1184 CONFIG_FTGMAC100_EGIGA 1185 Define this to use GE link update with gigabit PHY. 1186 Define this if FTGMAC100 is connected to gigabit PHY. 1187 If your system has 10/100 PHY only, it might not occur 1188 wrong behavior. Because PHY usually return timeout or 1189 useless data when polling gigabit status and gigabit 1190 control registers. This behavior won't affect the 1191 correctnessof 10/100 link speed update. 1192 1193 CONFIG_SMC911X 1194 Support for SMSC's LAN911x and LAN921x chips 1195 1196 CONFIG_SMC911X_BASE 1197 Define this to hold the physical address 1198 of the device (I/O space) 1199 1200 CONFIG_SMC911X_32_BIT 1201 Define this if data bus is 32 bits 1202 1203 CONFIG_SMC911X_16_BIT 1204 Define this if data bus is 16 bits. If your processor 1205 automatically converts one 32 bit word to two 16 bit 1206 words you may also try CONFIG_SMC911X_32_BIT. 1207 1208 CONFIG_SH_ETHER 1209 Support for Renesas on-chip Ethernet controller 1210 1211 CONFIG_SH_ETHER_USE_PORT 1212 Define the number of ports to be used 1213 1214 CONFIG_SH_ETHER_PHY_ADDR 1215 Define the ETH PHY's address 1216 1217 CONFIG_SH_ETHER_CACHE_WRITEBACK 1218 If this option is set, the driver enables cache flush. 1219 1220- TPM Support: 1221 CONFIG_TPM 1222 Support TPM devices. 1223 1224 CONFIG_TPM_TIS_I2C 1225 Support for i2c bus TPM devices. Only one device 1226 per system is supported at this time. 1227 1228 CONFIG_TPM_TIS_I2C_BUS_NUMBER 1229 Define the the i2c bus number for the TPM device 1230 1231 CONFIG_TPM_TIS_I2C_SLAVE_ADDRESS 1232 Define the TPM's address on the i2c bus 1233 1234 CONFIG_TPM_TIS_I2C_BURST_LIMITATION 1235 Define the burst count bytes upper limit 1236 1237 CONFIG_TPM_ATMEL_TWI 1238 Support for Atmel TWI TPM device. Requires I2C support. 1239 1240 CONFIG_TPM_TIS_LPC 1241 Support for generic parallel port TPM devices. Only one device 1242 per system is supported at this time. 1243 1244 CONFIG_TPM_TIS_BASE_ADDRESS 1245 Base address where the generic TPM device is mapped 1246 to. Contemporary x86 systems usually map it at 1247 0xfed40000. 1248 1249 CONFIG_CMD_TPM 1250 Add tpm monitor functions. 1251 Requires CONFIG_TPM. If CONFIG_TPM_AUTH_SESSIONS is set, also 1252 provides monitor access to authorized functions. 1253 1254 CONFIG_TPM 1255 Define this to enable the TPM support library which provides 1256 functional interfaces to some TPM commands. 1257 Requires support for a TPM device. 1258 1259 CONFIG_TPM_AUTH_SESSIONS 1260 Define this to enable authorized functions in the TPM library. 1261 Requires CONFIG_TPM and CONFIG_SHA1. 1262 1263- USB Support: 1264 At the moment only the UHCI host controller is 1265 supported (PIP405, MIP405, MPC5200); define 1266 CONFIG_USB_UHCI to enable it. 1267 define CONFIG_USB_KEYBOARD to enable the USB Keyboard 1268 and define CONFIG_USB_STORAGE to enable the USB 1269 storage devices. 1270 Note: 1271 Supported are USB Keyboards and USB Floppy drives 1272 (TEAC FD-05PUB). 1273 MPC5200 USB requires additional defines: 1274 CONFIG_USB_CLOCK 1275 for 528 MHz Clock: 0x0001bbbb 1276 CONFIG_PSC3_USB 1277 for USB on PSC3 1278 CONFIG_USB_CONFIG 1279 for differential drivers: 0x00001000 1280 for single ended drivers: 0x00005000 1281 for differential drivers on PSC3: 0x00000100 1282 for single ended drivers on PSC3: 0x00004100 1283 CONFIG_SYS_USB_EVENT_POLL 1284 May be defined to allow interrupt polling 1285 instead of using asynchronous interrupts 1286 1287 CONFIG_USB_EHCI_TXFIFO_THRESH enables setting of the 1288 txfilltuning field in the EHCI controller on reset. 1289 1290 CONFIG_USB_HUB_MIN_POWER_ON_DELAY defines the minimum 1291 interval for usb hub power-on delay.(minimum 100msec) 1292 1293- USB Device: 1294 Define the below if you wish to use the USB console. 1295 Once firmware is rebuilt from a serial console issue the 1296 command "setenv stdin usbtty; setenv stdout usbtty" and 1297 attach your USB cable. The Unix command "dmesg" should print 1298 it has found a new device. The environment variable usbtty 1299 can be set to gserial or cdc_acm to enable your device to 1300 appear to a USB host as a Linux gserial device or a 1301 Common Device Class Abstract Control Model serial device. 1302 If you select usbtty = gserial you should be able to enumerate 1303 a Linux host by 1304 # modprobe usbserial vendor=0xVendorID product=0xProductID 1305 else if using cdc_acm, simply setting the environment 1306 variable usbtty to be cdc_acm should suffice. The following 1307 might be defined in YourBoardName.h 1308 1309 CONFIG_USB_DEVICE 1310 Define this to build a UDC device 1311 1312 CONFIG_USB_TTY 1313 Define this to have a tty type of device available to 1314 talk to the UDC device 1315 1316 CONFIG_USBD_HS 1317 Define this to enable the high speed support for usb 1318 device and usbtty. If this feature is enabled, a routine 1319 int is_usbd_high_speed(void) 1320 also needs to be defined by the driver to dynamically poll 1321 whether the enumeration has succeded at high speed or full 1322 speed. 1323 1324 CONFIG_SYS_CONSOLE_IS_IN_ENV 1325 Define this if you want stdin, stdout &/or stderr to 1326 be set to usbtty. 1327 1328 mpc8xx: 1329 CONFIG_SYS_USB_EXTC_CLK 0xBLAH 1330 Derive USB clock from external clock "blah" 1331 - CONFIG_SYS_USB_EXTC_CLK 0x02 1332 1333 CONFIG_SYS_USB_BRG_CLK 0xBLAH 1334 Derive USB clock from brgclk 1335 - CONFIG_SYS_USB_BRG_CLK 0x04 1336 1337 If you have a USB-IF assigned VendorID then you may wish to 1338 define your own vendor specific values either in BoardName.h 1339 or directly in usbd_vendor_info.h. If you don't define 1340 CONFIG_USBD_MANUFACTURER, CONFIG_USBD_PRODUCT_NAME, 1341 CONFIG_USBD_VENDORID and CONFIG_USBD_PRODUCTID, then U-Boot 1342 should pretend to be a Linux device to it's target host. 1343 1344 CONFIG_USBD_MANUFACTURER 1345 Define this string as the name of your company for 1346 - CONFIG_USBD_MANUFACTURER "my company" 1347 1348 CONFIG_USBD_PRODUCT_NAME 1349 Define this string as the name of your product 1350 - CONFIG_USBD_PRODUCT_NAME "acme usb device" 1351 1352 CONFIG_USBD_VENDORID 1353 Define this as your assigned Vendor ID from the USB 1354 Implementors Forum. This *must* be a genuine Vendor ID 1355 to avoid polluting the USB namespace. 1356 - CONFIG_USBD_VENDORID 0xFFFF 1357 1358 CONFIG_USBD_PRODUCTID 1359 Define this as the unique Product ID 1360 for your device 1361 - CONFIG_USBD_PRODUCTID 0xFFFF 1362 1363- ULPI Layer Support: 1364 The ULPI (UTMI Low Pin (count) Interface) PHYs are supported via 1365 the generic ULPI layer. The generic layer accesses the ULPI PHY 1366 via the platform viewport, so you need both the genric layer and 1367 the viewport enabled. Currently only Chipidea/ARC based 1368 viewport is supported. 1369 To enable the ULPI layer support, define CONFIG_USB_ULPI and 1370 CONFIG_USB_ULPI_VIEWPORT in your board configuration file. 1371 If your ULPI phy needs a different reference clock than the 1372 standard 24 MHz then you have to define CONFIG_ULPI_REF_CLK to 1373 the appropriate value in Hz. 1374 1375- MMC Support: 1376 The MMC controller on the Intel PXA is supported. To 1377 enable this define CONFIG_MMC. The MMC can be 1378 accessed from the boot prompt by mapping the device 1379 to physical memory similar to flash. Command line is 1380 enabled with CONFIG_CMD_MMC. The MMC driver also works with 1381 the FAT fs. This is enabled with CONFIG_CMD_FAT. 1382 1383 CONFIG_SH_MMCIF 1384 Support for Renesas on-chip MMCIF controller 1385 1386 CONFIG_SH_MMCIF_ADDR 1387 Define the base address of MMCIF registers 1388 1389 CONFIG_SH_MMCIF_CLK 1390 Define the clock frequency for MMCIF 1391 1392- USB Device Firmware Update (DFU) class support: 1393 CONFIG_DFU_FUNCTION 1394 This enables the USB portion of the DFU USB class 1395 1396 CONFIG_CMD_DFU 1397 This enables the command "dfu" which is used to have 1398 U-Boot create a DFU class device via USB. This command 1399 requires that the "dfu_alt_info" environment variable be 1400 set and define the alt settings to expose to the host. 1401 1402 CONFIG_DFU_MMC 1403 This enables support for exposing (e)MMC devices via DFU. 1404 1405 CONFIG_DFU_NAND 1406 This enables support for exposing NAND devices via DFU. 1407 1408 CONFIG_SYS_DFU_DATA_BUF_SIZE 1409 Dfu transfer uses a buffer before writing data to the 1410 raw storage device. Make the size (in bytes) of this buffer 1411 configurable. The size of this buffer is also configurable 1412 through the "dfu_bufsiz" environment variable. 1413 1414 CONFIG_SYS_DFU_MAX_FILE_SIZE 1415 When updating files rather than the raw storage device, 1416 we use a static buffer to copy the file into and then write 1417 the buffer once we've been given the whole file. Define 1418 this to the maximum filesize (in bytes) for the buffer. 1419 Default is 4 MiB if undefined. 1420 1421- Journaling Flash filesystem support: 1422 CONFIG_JFFS2_NAND, CONFIG_JFFS2_NAND_OFF, CONFIG_JFFS2_NAND_SIZE, 1423 CONFIG_JFFS2_NAND_DEV 1424 Define these for a default partition on a NAND device 1425 1426 CONFIG_SYS_JFFS2_FIRST_SECTOR, 1427 CONFIG_SYS_JFFS2_FIRST_BANK, CONFIG_SYS_JFFS2_NUM_BANKS 1428 Define these for a default partition on a NOR device 1429 1430 CONFIG_SYS_JFFS_CUSTOM_PART 1431 Define this to create an own partition. You have to provide a 1432 function struct part_info* jffs2_part_info(int part_num) 1433 1434 If you define only one JFFS2 partition you may also want to 1435 #define CONFIG_SYS_JFFS_SINGLE_PART 1 1436 to disable the command chpart. This is the default when you 1437 have not defined a custom partition 1438 1439- FAT(File Allocation Table) filesystem write function support: 1440 CONFIG_FAT_WRITE 1441 1442 Define this to enable support for saving memory data as a 1443 file in FAT formatted partition. 1444 1445 This will also enable the command "fatwrite" enabling the 1446 user to write files to FAT. 1447 1448CBFS (Coreboot Filesystem) support 1449 CONFIG_CMD_CBFS 1450 1451 Define this to enable support for reading from a Coreboot 1452 filesystem. Available commands are cbfsinit, cbfsinfo, cbfsls 1453 and cbfsload. 1454 1455- Keyboard Support: 1456 CONFIG_ISA_KEYBOARD 1457 1458 Define this to enable standard (PC-Style) keyboard 1459 support 1460 1461 CONFIG_I8042_KBD 1462 Standard PC keyboard driver with US (is default) and 1463 GERMAN key layout (switch via environment 'keymap=de') support. 1464 Export function i8042_kbd_init, i8042_tstc and i8042_getc 1465 for cfb_console. Supports cursor blinking. 1466 1467 CONFIG_CROS_EC_KEYB 1468 Enables a Chrome OS keyboard using the CROS_EC interface. 1469 This uses CROS_EC to communicate with a second microcontroller 1470 which provides key scans on request. 1471 1472- Video support: 1473 CONFIG_VIDEO 1474 1475 Define this to enable video support (for output to 1476 video). 1477 1478 CONFIG_VIDEO_CT69000 1479 1480 Enable Chips & Technologies 69000 Video chip 1481 1482 CONFIG_VIDEO_SMI_LYNXEM 1483 Enable Silicon Motion SMI 712/710/810 Video chip. The 1484 video output is selected via environment 'videoout' 1485 (1 = LCD and 2 = CRT). If videoout is undefined, CRT is 1486 assumed. 1487 1488 For the CT69000 and SMI_LYNXEM drivers, videomode is 1489 selected via environment 'videomode'. Two different ways 1490 are possible: 1491 - "videomode=num" 'num' is a standard LiLo mode numbers. 1492 Following standard modes are supported (* is default): 1493 1494 Colors 640x480 800x600 1024x768 1152x864 1280x1024 1495 -------------+--------------------------------------------- 1496 8 bits | 0x301* 0x303 0x305 0x161 0x307 1497 15 bits | 0x310 0x313 0x316 0x162 0x319 1498 16 bits | 0x311 0x314 0x317 0x163 0x31A 1499 24 bits | 0x312 0x315 0x318 ? 0x31B 1500 -------------+--------------------------------------------- 1501 (i.e. setenv videomode 317; saveenv; reset;) 1502 1503 - "videomode=bootargs" all the video parameters are parsed 1504 from the bootargs. (See drivers/video/videomodes.c) 1505 1506 1507 CONFIG_VIDEO_SED13806 1508 Enable Epson SED13806 driver. This driver supports 8bpp 1509 and 16bpp modes defined by CONFIG_VIDEO_SED13806_8BPP 1510 or CONFIG_VIDEO_SED13806_16BPP 1511 1512 CONFIG_FSL_DIU_FB 1513 Enable the Freescale DIU video driver. Reference boards for 1514 SOCs that have a DIU should define this macro to enable DIU 1515 support, and should also define these other macros: 1516 1517 CONFIG_SYS_DIU_ADDR 1518 CONFIG_VIDEO 1519 CONFIG_CMD_BMP 1520 CONFIG_CFB_CONSOLE 1521 CONFIG_VIDEO_SW_CURSOR 1522 CONFIG_VGA_AS_SINGLE_DEVICE 1523 CONFIG_VIDEO_LOGO 1524 CONFIG_VIDEO_BMP_LOGO 1525 1526 The DIU driver will look for the 'video-mode' environment 1527 variable, and if defined, enable the DIU as a console during 1528 boot. See the documentation file README.video for a 1529 description of this variable. 1530 1531 CONFIG_VIDEO_VGA 1532 1533 Enable the VGA video / BIOS for x86. The alternative if you 1534 are using coreboot is to use the coreboot frame buffer 1535 driver. 1536 1537 1538- Keyboard Support: 1539 CONFIG_KEYBOARD 1540 1541 Define this to enable a custom keyboard support. 1542 This simply calls drv_keyboard_init() which must be 1543 defined in your board-specific files. 1544 The only board using this so far is RBC823. 1545 1546- LCD Support: CONFIG_LCD 1547 1548 Define this to enable LCD support (for output to LCD 1549 display); also select one of the supported displays 1550 by defining one of these: 1551 1552 CONFIG_ATMEL_LCD: 1553 1554 HITACHI TX09D70VM1CCA, 3.5", 240x320. 1555 1556 CONFIG_NEC_NL6448AC33: 1557 1558 NEC NL6448AC33-18. Active, color, single scan. 1559 1560 CONFIG_NEC_NL6448BC20 1561 1562 NEC NL6448BC20-08. 6.5", 640x480. 1563 Active, color, single scan. 1564 1565 CONFIG_NEC_NL6448BC33_54 1566 1567 NEC NL6448BC33-54. 10.4", 640x480. 1568 Active, color, single scan. 1569 1570 CONFIG_SHARP_16x9 1571 1572 Sharp 320x240. Active, color, single scan. 1573 It isn't 16x9, and I am not sure what it is. 1574 1575 CONFIG_SHARP_LQ64D341 1576 1577 Sharp LQ64D341 display, 640x480. 1578 Active, color, single scan. 1579 1580 CONFIG_HLD1045 1581 1582 HLD1045 display, 640x480. 1583 Active, color, single scan. 1584 1585 CONFIG_OPTREX_BW 1586 1587 Optrex CBL50840-2 NF-FW 99 22 M5 1588 or 1589 Hitachi LMG6912RPFC-00T 1590 or 1591 Hitachi SP14Q002 1592 1593 320x240. Black & white. 1594 1595 Normally display is black on white background; define 1596 CONFIG_SYS_WHITE_ON_BLACK to get it inverted. 1597 1598 CONFIG_LCD_ALIGNMENT 1599 1600 Normally the LCD is page-aligned (tyically 4KB). If this is 1601 defined then the LCD will be aligned to this value instead. 1602 For ARM it is sometimes useful to use MMU_SECTION_SIZE 1603 here, since it is cheaper to change data cache settings on 1604 a per-section basis. 1605 1606 CONFIG_CONSOLE_SCROLL_LINES 1607 1608 When the console need to be scrolled, this is the number of 1609 lines to scroll by. It defaults to 1. Increasing this makes 1610 the console jump but can help speed up operation when scrolling 1611 is slow. 1612 1613 CONFIG_LCD_BMP_RLE8 1614 1615 Support drawing of RLE8-compressed bitmaps on the LCD. 1616 1617 CONFIG_I2C_EDID 1618 1619 Enables an 'i2c edid' command which can read EDID 1620 information over I2C from an attached LCD display. 1621 1622- Splash Screen Support: CONFIG_SPLASH_SCREEN 1623 1624 If this option is set, the environment is checked for 1625 a variable "splashimage". If found, the usual display 1626 of logo, copyright and system information on the LCD 1627 is suppressed and the BMP image at the address 1628 specified in "splashimage" is loaded instead. The 1629 console is redirected to the "nulldev", too. This 1630 allows for a "silent" boot where a splash screen is 1631 loaded very quickly after power-on. 1632 1633 CONFIG_SPLASHIMAGE_GUARD 1634 1635 If this option is set, then U-Boot will prevent the environment 1636 variable "splashimage" from being set to a problematic address 1637 (see README.displaying-bmps and README.arm-unaligned-accesses). 1638 This option is useful for targets where, due to alignment 1639 restrictions, an improperly aligned BMP image will cause a data 1640 abort. If you think you will not have problems with unaligned 1641 accesses (for example because your toolchain prevents them) 1642 there is no need to set this option. 1643 1644 CONFIG_SPLASH_SCREEN_ALIGN 1645 1646 If this option is set the splash image can be freely positioned 1647 on the screen. Environment variable "splashpos" specifies the 1648 position as "x,y". If a positive number is given it is used as 1649 number of pixel from left/top. If a negative number is given it 1650 is used as number of pixel from right/bottom. You can also 1651 specify 'm' for centering the image. 1652 1653 Example: 1654 setenv splashpos m,m 1655 => image at center of screen 1656 1657 setenv splashpos 30,20 1658 => image at x = 30 and y = 20 1659 1660 setenv splashpos -10,m 1661 => vertically centered image 1662 at x = dspWidth - bmpWidth - 9 1663 1664- Gzip compressed BMP image support: CONFIG_VIDEO_BMP_GZIP 1665 1666 If this option is set, additionally to standard BMP 1667 images, gzipped BMP images can be displayed via the 1668 splashscreen support or the bmp command. 1669 1670- Run length encoded BMP image (RLE8) support: CONFIG_VIDEO_BMP_RLE8 1671 1672 If this option is set, 8-bit RLE compressed BMP images 1673 can be displayed via the splashscreen support or the 1674 bmp command. 1675 1676- Do compresssing for memory range: 1677 CONFIG_CMD_ZIP 1678 1679 If this option is set, it would use zlib deflate method 1680 to compress the specified memory at its best effort. 1681 1682- Compression support: 1683 CONFIG_GZIP 1684 1685 Enabled by default to support gzip compressed images. 1686 1687 CONFIG_BZIP2 1688 1689 If this option is set, support for bzip2 compressed 1690 images is included. If not, only uncompressed and gzip 1691 compressed images are supported. 1692 1693 NOTE: the bzip2 algorithm requires a lot of RAM, so 1694 the malloc area (as defined by CONFIG_SYS_MALLOC_LEN) should 1695 be at least 4MB. 1696 1697 CONFIG_LZMA 1698 1699 If this option is set, support for lzma compressed 1700 images is included. 1701 1702 Note: The LZMA algorithm adds between 2 and 4KB of code and it 1703 requires an amount of dynamic memory that is given by the 1704 formula: 1705 1706 (1846 + 768 << (lc + lp)) * sizeof(uint16) 1707 1708 Where lc and lp stand for, respectively, Literal context bits 1709 and Literal pos bits. 1710 1711 This value is upper-bounded by 14MB in the worst case. Anyway, 1712 for a ~4MB large kernel image, we have lc=3 and lp=0 for a 1713 total amount of (1846 + 768 << (3 + 0)) * 2 = ~41KB... that is 1714 a very small buffer. 1715 1716 Use the lzmainfo tool to determinate the lc and lp values and 1717 then calculate the amount of needed dynamic memory (ensuring 1718 the appropriate CONFIG_SYS_MALLOC_LEN value). 1719 1720 CONFIG_LZO 1721 1722 If this option is set, support for LZO compressed images 1723 is included. 1724 1725- MII/PHY support: 1726 CONFIG_PHY_ADDR 1727 1728 The address of PHY on MII bus. 1729 1730 CONFIG_PHY_CLOCK_FREQ (ppc4xx) 1731 1732 The clock frequency of the MII bus 1733 1734 CONFIG_PHY_GIGE 1735 1736 If this option is set, support for speed/duplex 1737 detection of gigabit PHY is included. 1738 1739 CONFIG_PHY_RESET_DELAY 1740 1741 Some PHY like Intel LXT971A need extra delay after 1742 reset before any MII register access is possible. 1743 For such PHY, set this option to the usec delay 1744 required. (minimum 300usec for LXT971A) 1745 1746 CONFIG_PHY_CMD_DELAY (ppc4xx) 1747 1748 Some PHY like Intel LXT971A need extra delay after 1749 command issued before MII status register can be read 1750 1751- Ethernet address: 1752 CONFIG_ETHADDR 1753 CONFIG_ETH1ADDR 1754 CONFIG_ETH2ADDR 1755 CONFIG_ETH3ADDR 1756 CONFIG_ETH4ADDR 1757 CONFIG_ETH5ADDR 1758 1759 Define a default value for Ethernet address to use 1760 for the respective Ethernet interface, in case this 1761 is not determined automatically. 1762 1763- IP address: 1764 CONFIG_IPADDR 1765 1766 Define a default value for the IP address to use for 1767 the default Ethernet interface, in case this is not 1768 determined through e.g. bootp. 1769 (Environment variable "ipaddr") 1770 1771- Server IP address: 1772 CONFIG_SERVERIP 1773 1774 Defines a default value for the IP address of a TFTP 1775 server to contact when using the "tftboot" command. 1776 (Environment variable "serverip") 1777 1778 CONFIG_KEEP_SERVERADDR 1779 1780 Keeps the server's MAC address, in the env 'serveraddr' 1781 for passing to bootargs (like Linux's netconsole option) 1782 1783- Gateway IP address: 1784 CONFIG_GATEWAYIP 1785 1786 Defines a default value for the IP address of the 1787 default router where packets to other networks are 1788 sent to. 1789 (Environment variable "gatewayip") 1790 1791- Subnet mask: 1792 CONFIG_NETMASK 1793 1794 Defines a default value for the subnet mask (or 1795 routing prefix) which is used to determine if an IP 1796 address belongs to the local subnet or needs to be 1797 forwarded through a router. 1798 (Environment variable "netmask") 1799 1800- Multicast TFTP Mode: 1801 CONFIG_MCAST_TFTP 1802 1803 Defines whether you want to support multicast TFTP as per 1804 rfc-2090; for example to work with atftp. Lets lots of targets 1805 tftp down the same boot image concurrently. Note: the Ethernet 1806 driver in use must provide a function: mcast() to join/leave a 1807 multicast group. 1808 1809- BOOTP Recovery Mode: 1810 CONFIG_BOOTP_RANDOM_DELAY 1811 1812 If you have many targets in a network that try to 1813 boot using BOOTP, you may want to avoid that all 1814 systems send out BOOTP requests at precisely the same 1815 moment (which would happen for instance at recovery 1816 from a power failure, when all systems will try to 1817 boot, thus flooding the BOOTP server. Defining 1818 CONFIG_BOOTP_RANDOM_DELAY causes a random delay to be 1819 inserted before sending out BOOTP requests. The 1820 following delays are inserted then: 1821 1822 1st BOOTP request: delay 0 ... 1 sec 1823 2nd BOOTP request: delay 0 ... 2 sec 1824 3rd BOOTP request: delay 0 ... 4 sec 1825 4th and following 1826 BOOTP requests: delay 0 ... 8 sec 1827 1828- DHCP Advanced Options: 1829 You can fine tune the DHCP functionality by defining 1830 CONFIG_BOOTP_* symbols: 1831 1832 CONFIG_BOOTP_SUBNETMASK 1833 CONFIG_BOOTP_GATEWAY 1834 CONFIG_BOOTP_HOSTNAME 1835 CONFIG_BOOTP_NISDOMAIN 1836 CONFIG_BOOTP_BOOTPATH 1837 CONFIG_BOOTP_BOOTFILESIZE 1838 CONFIG_BOOTP_DNS 1839 CONFIG_BOOTP_DNS2 1840 CONFIG_BOOTP_SEND_HOSTNAME 1841 CONFIG_BOOTP_NTPSERVER 1842 CONFIG_BOOTP_TIMEOFFSET 1843 CONFIG_BOOTP_VENDOREX 1844 CONFIG_BOOTP_MAY_FAIL 1845 1846 CONFIG_BOOTP_SERVERIP - TFTP server will be the serverip 1847 environment variable, not the BOOTP server. 1848 1849 CONFIG_BOOTP_MAY_FAIL - If the DHCP server is not found 1850 after the configured retry count, the call will fail 1851 instead of starting over. This can be used to fail over 1852 to Link-local IP address configuration if the DHCP server 1853 is not available. 1854 1855 CONFIG_BOOTP_DNS2 - If a DHCP client requests the DNS 1856 serverip from a DHCP server, it is possible that more 1857 than one DNS serverip is offered to the client. 1858 If CONFIG_BOOTP_DNS2 is enabled, the secondary DNS 1859 serverip will be stored in the additional environment 1860 variable "dnsip2". The first DNS serverip is always 1861 stored in the variable "dnsip", when CONFIG_BOOTP_DNS 1862 is defined. 1863 1864 CONFIG_BOOTP_SEND_HOSTNAME - Some DHCP servers are capable 1865 to do a dynamic update of a DNS server. To do this, they 1866 need the hostname of the DHCP requester. 1867 If CONFIG_BOOTP_SEND_HOSTNAME is defined, the content 1868 of the "hostname" environment variable is passed as 1869 option 12 to the DHCP server. 1870 1871 CONFIG_BOOTP_DHCP_REQUEST_DELAY 1872 1873 A 32bit value in microseconds for a delay between 1874 receiving a "DHCP Offer" and sending the "DHCP Request". 1875 This fixes a problem with certain DHCP servers that don't 1876 respond 100% of the time to a "DHCP request". E.g. On an 1877 AT91RM9200 processor running at 180MHz, this delay needed 1878 to be *at least* 15,000 usec before a Windows Server 2003 1879 DHCP server would reply 100% of the time. I recommend at 1880 least 50,000 usec to be safe. The alternative is to hope 1881 that one of the retries will be successful but note that 1882 the DHCP timeout and retry process takes a longer than 1883 this delay. 1884 1885 - Link-local IP address negotiation: 1886 Negotiate with other link-local clients on the local network 1887 for an address that doesn't require explicit configuration. 1888 This is especially useful if a DHCP server cannot be guaranteed 1889 to exist in all environments that the device must operate. 1890 1891 See doc/README.link-local for more information. 1892 1893 - CDP Options: 1894 CONFIG_CDP_DEVICE_ID 1895 1896 The device id used in CDP trigger frames. 1897 1898 CONFIG_CDP_DEVICE_ID_PREFIX 1899 1900 A two character string which is prefixed to the MAC address 1901 of the device. 1902 1903 CONFIG_CDP_PORT_ID 1904 1905 A printf format string which contains the ascii name of 1906 the port. Normally is set to "eth%d" which sets 1907 eth0 for the first Ethernet, eth1 for the second etc. 1908 1909 CONFIG_CDP_CAPABILITIES 1910 1911 A 32bit integer which indicates the device capabilities; 1912 0x00000010 for a normal host which does not forwards. 1913 1914 CONFIG_CDP_VERSION 1915 1916 An ascii string containing the version of the software. 1917 1918 CONFIG_CDP_PLATFORM 1919 1920 An ascii string containing the name of the platform. 1921 1922 CONFIG_CDP_TRIGGER 1923 1924 A 32bit integer sent on the trigger. 1925 1926 CONFIG_CDP_POWER_CONSUMPTION 1927 1928 A 16bit integer containing the power consumption of the 1929 device in .1 of milliwatts. 1930 1931 CONFIG_CDP_APPLIANCE_VLAN_TYPE 1932 1933 A byte containing the id of the VLAN. 1934 1935- Status LED: CONFIG_STATUS_LED 1936 1937 Several configurations allow to display the current 1938 status using a LED. For instance, the LED will blink 1939 fast while running U-Boot code, stop blinking as 1940 soon as a reply to a BOOTP request was received, and 1941 start blinking slow once the Linux kernel is running 1942 (supported by a status LED driver in the Linux 1943 kernel). Defining CONFIG_STATUS_LED enables this 1944 feature in U-Boot. 1945 1946- CAN Support: CONFIG_CAN_DRIVER 1947 1948 Defining CONFIG_CAN_DRIVER enables CAN driver support 1949 on those systems that support this (optional) 1950 feature, like the TQM8xxL modules. 1951 1952- I2C Support: CONFIG_SYS_I2C 1953 1954 This enable the NEW i2c subsystem, and will allow you to use 1955 i2c commands at the u-boot command line (as long as you set 1956 CONFIG_CMD_I2C in CONFIG_COMMANDS) and communicate with i2c 1957 based realtime clock chips or other i2c devices. See 1958 common/cmd_i2c.c for a description of the command line 1959 interface. 1960 1961 ported i2c driver to the new framework: 1962 - drivers/i2c/soft_i2c.c: 1963 - activate first bus with CONFIG_SYS_I2C_SOFT define 1964 CONFIG_SYS_I2C_SOFT_SPEED and CONFIG_SYS_I2C_SOFT_SLAVE 1965 for defining speed and slave address 1966 - activate second bus with I2C_SOFT_DECLARATIONS2 define 1967 CONFIG_SYS_I2C_SOFT_SPEED_2 and CONFIG_SYS_I2C_SOFT_SLAVE_2 1968 for defining speed and slave address 1969 - activate third bus with I2C_SOFT_DECLARATIONS3 define 1970 CONFIG_SYS_I2C_SOFT_SPEED_3 and CONFIG_SYS_I2C_SOFT_SLAVE_3 1971 for defining speed and slave address 1972 - activate fourth bus with I2C_SOFT_DECLARATIONS4 define 1973 CONFIG_SYS_I2C_SOFT_SPEED_4 and CONFIG_SYS_I2C_SOFT_SLAVE_4 1974 for defining speed and slave address 1975 1976 - drivers/i2c/fsl_i2c.c: 1977 - activate i2c driver with CONFIG_SYS_I2C_FSL 1978 define CONFIG_SYS_FSL_I2C_OFFSET for setting the register 1979 offset CONFIG_SYS_FSL_I2C_SPEED for the i2c speed and 1980 CONFIG_SYS_FSL_I2C_SLAVE for the slave addr of the first 1981 bus. 1982 - If your board supports a second fsl i2c bus, define 1983 CONFIG_SYS_FSL_I2C2_OFFSET for the register offset 1984 CONFIG_SYS_FSL_I2C2_SPEED for the speed and 1985 CONFIG_SYS_FSL_I2C2_SLAVE for the slave address of the 1986 second bus. 1987 1988 - drivers/i2c/tegra_i2c.c: 1989 - activate this driver with CONFIG_SYS_I2C_TEGRA 1990 - This driver adds 4 i2c buses with a fix speed from 1991 100000 and the slave addr 0! 1992 1993 - drivers/i2c/ppc4xx_i2c.c 1994 - activate this driver with CONFIG_SYS_I2C_PPC4XX 1995 - CONFIG_SYS_I2C_PPC4XX_CH0 activate hardware channel 0 1996 - CONFIG_SYS_I2C_PPC4XX_CH1 activate hardware channel 1 1997 1998 additional defines: 1999 2000 CONFIG_SYS_NUM_I2C_BUSES 2001 Hold the number of i2c busses you want to use. If you 2002 don't use/have i2c muxes on your i2c bus, this 2003 is equal to CONFIG_SYS_NUM_I2C_ADAPTERS, and you can 2004 omit this define. 2005 2006 CONFIG_SYS_I2C_DIRECT_BUS 2007 define this, if you don't use i2c muxes on your hardware. 2008 if CONFIG_SYS_I2C_MAX_HOPS is not defined or == 0 you can 2009 omit this define. 2010 2011 CONFIG_SYS_I2C_MAX_HOPS 2012 define how many muxes are maximal consecutively connected 2013 on one i2c bus. If you not use i2c muxes, omit this 2014 define. 2015 2016 CONFIG_SYS_I2C_BUSES 2017 hold a list of busses you want to use, only used if 2018 CONFIG_SYS_I2C_DIRECT_BUS is not defined, for example 2019 a board with CONFIG_SYS_I2C_MAX_HOPS = 1 and 2020 CONFIG_SYS_NUM_I2C_BUSES = 9: 2021 2022 CONFIG_SYS_I2C_BUSES {{0, {I2C_NULL_HOP}}, \ 2023 {0, {{I2C_MUX_PCA9547, 0x70, 1}}}, \ 2024 {0, {{I2C_MUX_PCA9547, 0x70, 2}}}, \ 2025 {0, {{I2C_MUX_PCA9547, 0x70, 3}}}, \ 2026 {0, {{I2C_MUX_PCA9547, 0x70, 4}}}, \ 2027 {0, {{I2C_MUX_PCA9547, 0x70, 5}}}, \ 2028 {1, {I2C_NULL_HOP}}, \ 2029 {1, {{I2C_MUX_PCA9544, 0x72, 1}}}, \ 2030 {1, {{I2C_MUX_PCA9544, 0x72, 2}}}, \ 2031 } 2032 2033 which defines 2034 bus 0 on adapter 0 without a mux 2035 bus 1 on adapter 0 with a PCA9547 on address 0x70 port 1 2036 bus 2 on adapter 0 with a PCA9547 on address 0x70 port 2 2037 bus 3 on adapter 0 with a PCA9547 on address 0x70 port 3 2038 bus 4 on adapter 0 with a PCA9547 on address 0x70 port 4 2039 bus 5 on adapter 0 with a PCA9547 on address 0x70 port 5 2040 bus 6 on adapter 1 without a mux 2041 bus 7 on adapter 1 with a PCA9544 on address 0x72 port 1 2042 bus 8 on adapter 1 with a PCA9544 on address 0x72 port 2 2043 2044 If you do not have i2c muxes on your board, omit this define. 2045 2046- Legacy I2C Support: CONFIG_HARD_I2C 2047 2048 NOTE: It is intended to move drivers to CONFIG_SYS_I2C which 2049 provides the following compelling advantages: 2050 2051 - more than one i2c adapter is usable 2052 - approved multibus support 2053 - better i2c mux support 2054 2055 ** Please consider updating your I2C driver now. ** 2056 2057 These enable legacy I2C serial bus commands. Defining 2058 CONFIG_HARD_I2C will include the appropriate I2C driver 2059 for the selected CPU. 2060 2061 This will allow you to use i2c commands at the u-boot 2062 command line (as long as you set CONFIG_CMD_I2C in 2063 CONFIG_COMMANDS) and communicate with i2c based realtime 2064 clock chips. See common/cmd_i2c.c for a description of the 2065 command line interface. 2066 2067 CONFIG_HARD_I2C selects a hardware I2C controller. 2068 2069 There are several other quantities that must also be 2070 defined when you define CONFIG_HARD_I2C. 2071 2072 In both cases you will need to define CONFIG_SYS_I2C_SPEED 2073 to be the frequency (in Hz) at which you wish your i2c bus 2074 to run and CONFIG_SYS_I2C_SLAVE to be the address of this node (ie 2075 the CPU's i2c node address). 2076 2077 Now, the u-boot i2c code for the mpc8xx 2078 (arch/powerpc/cpu/mpc8xx/i2c.c) sets the CPU up as a master node 2079 and so its address should therefore be cleared to 0 (See, 2080 eg, MPC823e User's Manual p.16-473). So, set 2081 CONFIG_SYS_I2C_SLAVE to 0. 2082 2083 CONFIG_SYS_I2C_INIT_MPC5XXX 2084 2085 When a board is reset during an i2c bus transfer 2086 chips might think that the current transfer is still 2087 in progress. Reset the slave devices by sending start 2088 commands until the slave device responds. 2089 2090 That's all that's required for CONFIG_HARD_I2C. 2091 2092 If you use the software i2c interface (CONFIG_SYS_I2C_SOFT) 2093 then the following macros need to be defined (examples are 2094 from include/configs/lwmon.h): 2095 2096 I2C_INIT 2097 2098 (Optional). Any commands necessary to enable the I2C 2099 controller or configure ports. 2100 2101 eg: #define I2C_INIT (immr->im_cpm.cp_pbdir |= PB_SCL) 2102 2103 I2C_PORT 2104 2105 (Only for MPC8260 CPU). The I/O port to use (the code 2106 assumes both bits are on the same port). Valid values 2107 are 0..3 for ports A..D. 2108 2109 I2C_ACTIVE 2110 2111 The code necessary to make the I2C data line active 2112 (driven). If the data line is open collector, this 2113 define can be null. 2114 2115 eg: #define I2C_ACTIVE (immr->im_cpm.cp_pbdir |= PB_SDA) 2116 2117 I2C_TRISTATE 2118 2119 The code necessary to make the I2C data line tri-stated 2120 (inactive). If the data line is open collector, this 2121 define can be null. 2122 2123 eg: #define I2C_TRISTATE (immr->im_cpm.cp_pbdir &= ~PB_SDA) 2124 2125 I2C_READ 2126 2127 Code that returns true if the I2C data line is high, 2128 false if it is low. 2129 2130 eg: #define I2C_READ ((immr->im_cpm.cp_pbdat & PB_SDA) != 0) 2131 2132 I2C_SDA(bit) 2133 2134 If <bit> is true, sets the I2C data line high. If it 2135 is false, it clears it (low). 2136 2137 eg: #define I2C_SDA(bit) \ 2138 if(bit) immr->im_cpm.cp_pbdat |= PB_SDA; \ 2139 else immr->im_cpm.cp_pbdat &= ~PB_SDA 2140 2141 I2C_SCL(bit) 2142 2143 If <bit> is true, sets the I2C clock line high. If it 2144 is false, it clears it (low). 2145 2146 eg: #define I2C_SCL(bit) \ 2147 if(bit) immr->im_cpm.cp_pbdat |= PB_SCL; \ 2148 else immr->im_cpm.cp_pbdat &= ~PB_SCL 2149 2150 I2C_DELAY 2151 2152 This delay is invoked four times per clock cycle so this 2153 controls the rate of data transfer. The data rate thus 2154 is 1 / (I2C_DELAY * 4). Often defined to be something 2155 like: 2156 2157 #define I2C_DELAY udelay(2) 2158 2159 CONFIG_SOFT_I2C_GPIO_SCL / CONFIG_SOFT_I2C_GPIO_SDA 2160 2161 If your arch supports the generic GPIO framework (asm/gpio.h), 2162 then you may alternatively define the two GPIOs that are to be 2163 used as SCL / SDA. Any of the previous I2C_xxx macros will 2164 have GPIO-based defaults assigned to them as appropriate. 2165 2166 You should define these to the GPIO value as given directly to 2167 the generic GPIO functions. 2168 2169 CONFIG_SYS_I2C_INIT_BOARD 2170 2171 When a board is reset during an i2c bus transfer 2172 chips might think that the current transfer is still 2173 in progress. On some boards it is possible to access 2174 the i2c SCLK line directly, either by using the 2175 processor pin as a GPIO or by having a second pin 2176 connected to the bus. If this option is defined a 2177 custom i2c_init_board() routine in boards/xxx/board.c 2178 is run early in the boot sequence. 2179 2180 CONFIG_SYS_I2C_BOARD_LATE_INIT 2181 2182 An alternative to CONFIG_SYS_I2C_INIT_BOARD. If this option is 2183 defined a custom i2c_board_late_init() routine in 2184 boards/xxx/board.c is run AFTER the operations in i2c_init() 2185 is completed. This callpoint can be used to unreset i2c bus 2186 using CPU i2c controller register accesses for CPUs whose i2c 2187 controller provide such a method. It is called at the end of 2188 i2c_init() to allow i2c_init operations to setup the i2c bus 2189 controller on the CPU (e.g. setting bus speed & slave address). 2190 2191 CONFIG_I2CFAST (PPC405GP|PPC405EP only) 2192 2193 This option enables configuration of bi_iic_fast[] flags 2194 in u-boot bd_info structure based on u-boot environment 2195 variable "i2cfast". (see also i2cfast) 2196 2197 CONFIG_I2C_MULTI_BUS 2198 2199 This option allows the use of multiple I2C buses, each of which 2200 must have a controller. At any point in time, only one bus is 2201 active. To switch to a different bus, use the 'i2c dev' command. 2202 Note that bus numbering is zero-based. 2203 2204 CONFIG_SYS_I2C_NOPROBES 2205 2206 This option specifies a list of I2C devices that will be skipped 2207 when the 'i2c probe' command is issued. If CONFIG_I2C_MULTI_BUS 2208 is set, specify a list of bus-device pairs. Otherwise, specify 2209 a 1D array of device addresses 2210 2211 e.g. 2212 #undef CONFIG_I2C_MULTI_BUS 2213 #define CONFIG_SYS_I2C_NOPROBES {0x50,0x68} 2214 2215 will skip addresses 0x50 and 0x68 on a board with one I2C bus 2216 2217 #define CONFIG_I2C_MULTI_BUS 2218 #define CONFIG_SYS_I2C_MULTI_NOPROBES {{0,0x50},{0,0x68},{1,0x54}} 2219 2220 will skip addresses 0x50 and 0x68 on bus 0 and address 0x54 on bus 1 2221 2222 CONFIG_SYS_SPD_BUS_NUM 2223 2224 If defined, then this indicates the I2C bus number for DDR SPD. 2225 If not defined, then U-Boot assumes that SPD is on I2C bus 0. 2226 2227 CONFIG_SYS_RTC_BUS_NUM 2228 2229 If defined, then this indicates the I2C bus number for the RTC. 2230 If not defined, then U-Boot assumes that RTC is on I2C bus 0. 2231 2232 CONFIG_SYS_DTT_BUS_NUM 2233 2234 If defined, then this indicates the I2C bus number for the DTT. 2235 If not defined, then U-Boot assumes that DTT is on I2C bus 0. 2236 2237 CONFIG_SYS_I2C_DTT_ADDR: 2238 2239 If defined, specifies the I2C address of the DTT device. 2240 If not defined, then U-Boot uses predefined value for 2241 specified DTT device. 2242 2243 CONFIG_SOFT_I2C_READ_REPEATED_START 2244 2245 defining this will force the i2c_read() function in 2246 the soft_i2c driver to perform an I2C repeated start 2247 between writing the address pointer and reading the 2248 data. If this define is omitted the default behaviour 2249 of doing a stop-start sequence will be used. Most I2C 2250 devices can use either method, but some require one or 2251 the other. 2252 2253- SPI Support: CONFIG_SPI 2254 2255 Enables SPI driver (so far only tested with 2256 SPI EEPROM, also an instance works with Crystal A/D and 2257 D/As on the SACSng board) 2258 2259 CONFIG_SH_SPI 2260 2261 Enables the driver for SPI controller on SuperH. Currently 2262 only SH7757 is supported. 2263 2264 CONFIG_SPI_X 2265 2266 Enables extended (16-bit) SPI EEPROM addressing. 2267 (symmetrical to CONFIG_I2C_X) 2268 2269 CONFIG_SOFT_SPI 2270 2271 Enables a software (bit-bang) SPI driver rather than 2272 using hardware support. This is a general purpose 2273 driver that only requires three general I/O port pins 2274 (two outputs, one input) to function. If this is 2275 defined, the board configuration must define several 2276 SPI configuration items (port pins to use, etc). For 2277 an example, see include/configs/sacsng.h. 2278 2279 CONFIG_HARD_SPI 2280 2281 Enables a hardware SPI driver for general-purpose reads 2282 and writes. As with CONFIG_SOFT_SPI, the board configuration 2283 must define a list of chip-select function pointers. 2284 Currently supported on some MPC8xxx processors. For an 2285 example, see include/configs/mpc8349emds.h. 2286 2287 CONFIG_MXC_SPI 2288 2289 Enables the driver for the SPI controllers on i.MX and MXC 2290 SoCs. Currently i.MX31/35/51 are supported. 2291 2292- FPGA Support: CONFIG_FPGA 2293 2294 Enables FPGA subsystem. 2295 2296 CONFIG_FPGA_<vendor> 2297 2298 Enables support for specific chip vendors. 2299 (ALTERA, XILINX) 2300 2301 CONFIG_FPGA_<family> 2302 2303 Enables support for FPGA family. 2304 (SPARTAN2, SPARTAN3, VIRTEX2, CYCLONE2, ACEX1K, ACEX) 2305 2306 CONFIG_FPGA_COUNT 2307 2308 Specify the number of FPGA devices to support. 2309 2310 CONFIG_SYS_FPGA_PROG_FEEDBACK 2311 2312 Enable printing of hash marks during FPGA configuration. 2313 2314 CONFIG_SYS_FPGA_CHECK_BUSY 2315 2316 Enable checks on FPGA configuration interface busy 2317 status by the configuration function. This option 2318 will require a board or device specific function to 2319 be written. 2320 2321 CONFIG_FPGA_DELAY 2322 2323 If defined, a function that provides delays in the FPGA 2324 configuration driver. 2325 2326 CONFIG_SYS_FPGA_CHECK_CTRLC 2327 Allow Control-C to interrupt FPGA configuration 2328 2329 CONFIG_SYS_FPGA_CHECK_ERROR 2330 2331 Check for configuration errors during FPGA bitfile 2332 loading. For example, abort during Virtex II 2333 configuration if the INIT_B line goes low (which 2334 indicated a CRC error). 2335 2336 CONFIG_SYS_FPGA_WAIT_INIT 2337 2338 Maximum time to wait for the INIT_B line to deassert 2339 after PROB_B has been deasserted during a Virtex II 2340 FPGA configuration sequence. The default time is 500 2341 ms. 2342 2343 CONFIG_SYS_FPGA_WAIT_BUSY 2344 2345 Maximum time to wait for BUSY to deassert during 2346 Virtex II FPGA configuration. The default is 5 ms. 2347 2348 CONFIG_SYS_FPGA_WAIT_CONFIG 2349 2350 Time to wait after FPGA configuration. The default is 2351 200 ms. 2352 2353- Configuration Management: 2354 CONFIG_IDENT_STRING 2355 2356 If defined, this string will be added to the U-Boot 2357 version information (U_BOOT_VERSION) 2358 2359- Vendor Parameter Protection: 2360 2361 U-Boot considers the values of the environment 2362 variables "serial#" (Board Serial Number) and 2363 "ethaddr" (Ethernet Address) to be parameters that 2364 are set once by the board vendor / manufacturer, and 2365 protects these variables from casual modification by 2366 the user. Once set, these variables are read-only, 2367 and write or delete attempts are rejected. You can 2368 change this behaviour: 2369 2370 If CONFIG_ENV_OVERWRITE is #defined in your config 2371 file, the write protection for vendor parameters is 2372 completely disabled. Anybody can change or delete 2373 these parameters. 2374 2375 Alternatively, if you #define _both_ CONFIG_ETHADDR 2376 _and_ CONFIG_OVERWRITE_ETHADDR_ONCE, a default 2377 Ethernet address is installed in the environment, 2378 which can be changed exactly ONCE by the user. [The 2379 serial# is unaffected by this, i. e. it remains 2380 read-only.] 2381 2382 The same can be accomplished in a more flexible way 2383 for any variable by configuring the type of access 2384 to allow for those variables in the ".flags" variable 2385 or define CONFIG_ENV_FLAGS_LIST_STATIC. 2386 2387- Protected RAM: 2388 CONFIG_PRAM 2389 2390 Define this variable to enable the reservation of 2391 "protected RAM", i. e. RAM which is not overwritten 2392 by U-Boot. Define CONFIG_PRAM to hold the number of 2393 kB you want to reserve for pRAM. You can overwrite 2394 this default value by defining an environment 2395 variable "pram" to the number of kB you want to 2396 reserve. Note that the board info structure will 2397 still show the full amount of RAM. If pRAM is 2398 reserved, a new environment variable "mem" will 2399 automatically be defined to hold the amount of 2400 remaining RAM in a form that can be passed as boot 2401 argument to Linux, for instance like that: 2402 2403 setenv bootargs ... mem=\${mem} 2404 saveenv 2405 2406 This way you can tell Linux not to use this memory, 2407 either, which results in a memory region that will 2408 not be affected by reboots. 2409 2410 *WARNING* If your board configuration uses automatic 2411 detection of the RAM size, you must make sure that 2412 this memory test is non-destructive. So far, the 2413 following board configurations are known to be 2414 "pRAM-clean": 2415 2416 IVMS8, IVML24, SPD8xx, TQM8xxL, 2417 HERMES, IP860, RPXlite, LWMON, 2418 FLAGADM, TQM8260 2419 2420- Access to physical memory region (> 4GB) 2421 Some basic support is provided for operations on memory not 2422 normally accessible to U-Boot - e.g. some architectures 2423 support access to more than 4GB of memory on 32-bit 2424 machines using physical address extension or similar. 2425 Define CONFIG_PHYSMEM to access this basic support, which 2426 currently only supports clearing the memory. 2427 2428- Error Recovery: 2429 CONFIG_PANIC_HANG 2430 2431 Define this variable to stop the system in case of a 2432 fatal error, so that you have to reset it manually. 2433 This is probably NOT a good idea for an embedded 2434 system where you want the system to reboot 2435 automatically as fast as possible, but it may be 2436 useful during development since you can try to debug 2437 the conditions that lead to the situation. 2438 2439 CONFIG_NET_RETRY_COUNT 2440 2441 This variable defines the number of retries for 2442 network operations like ARP, RARP, TFTP, or BOOTP 2443 before giving up the operation. If not defined, a 2444 default value of 5 is used. 2445 2446 CONFIG_ARP_TIMEOUT 2447 2448 Timeout waiting for an ARP reply in milliseconds. 2449 2450 CONFIG_NFS_TIMEOUT 2451 2452 Timeout in milliseconds used in NFS protocol. 2453 If you encounter "ERROR: Cannot umount" in nfs command, 2454 try longer timeout such as 2455 #define CONFIG_NFS_TIMEOUT 10000UL 2456 2457- Command Interpreter: 2458 CONFIG_AUTO_COMPLETE 2459 2460 Enable auto completion of commands using TAB. 2461 2462 Note that this feature has NOT been implemented yet 2463 for the "hush" shell. 2464 2465 2466 CONFIG_SYS_HUSH_PARSER 2467 2468 Define this variable to enable the "hush" shell (from 2469 Busybox) as command line interpreter, thus enabling 2470 powerful command line syntax like 2471 if...then...else...fi conditionals or `&&' and '||' 2472 constructs ("shell scripts"). 2473 2474 If undefined, you get the old, much simpler behaviour 2475 with a somewhat smaller memory footprint. 2476 2477 2478 CONFIG_SYS_PROMPT_HUSH_PS2 2479 2480 This defines the secondary prompt string, which is 2481 printed when the command interpreter needs more input 2482 to complete a command. Usually "> ". 2483 2484 Note: 2485 2486 In the current implementation, the local variables 2487 space and global environment variables space are 2488 separated. Local variables are those you define by 2489 simply typing `name=value'. To access a local 2490 variable later on, you have write `$name' or 2491 `${name}'; to execute the contents of a variable 2492 directly type `$name' at the command prompt. 2493 2494 Global environment variables are those you use 2495 setenv/printenv to work with. To run a command stored 2496 in such a variable, you need to use the run command, 2497 and you must not use the '$' sign to access them. 2498 2499 To store commands and special characters in a 2500 variable, please use double quotation marks 2501 surrounding the whole text of the variable, instead 2502 of the backslashes before semicolons and special 2503 symbols. 2504 2505- Commandline Editing and History: 2506 CONFIG_CMDLINE_EDITING 2507 2508 Enable editing and History functions for interactive 2509 commandline input operations 2510 2511- Default Environment: 2512 CONFIG_EXTRA_ENV_SETTINGS 2513 2514 Define this to contain any number of null terminated 2515 strings (variable = value pairs) that will be part of 2516 the default environment compiled into the boot image. 2517 2518 For example, place something like this in your 2519 board's config file: 2520 2521 #define CONFIG_EXTRA_ENV_SETTINGS \ 2522 "myvar1=value1\0" \ 2523 "myvar2=value2\0" 2524 2525 Warning: This method is based on knowledge about the 2526 internal format how the environment is stored by the 2527 U-Boot code. This is NOT an official, exported 2528 interface! Although it is unlikely that this format 2529 will change soon, there is no guarantee either. 2530 You better know what you are doing here. 2531 2532 Note: overly (ab)use of the default environment is 2533 discouraged. Make sure to check other ways to preset 2534 the environment like the "source" command or the 2535 boot command first. 2536 2537 CONFIG_ENV_VARS_UBOOT_CONFIG 2538 2539 Define this in order to add variables describing the 2540 U-Boot build configuration to the default environment. 2541 These will be named arch, cpu, board, vendor, and soc. 2542 2543 Enabling this option will cause the following to be defined: 2544 2545 - CONFIG_SYS_ARCH 2546 - CONFIG_SYS_CPU 2547 - CONFIG_SYS_BOARD 2548 - CONFIG_SYS_VENDOR 2549 - CONFIG_SYS_SOC 2550 2551 CONFIG_ENV_VARS_UBOOT_RUNTIME_CONFIG 2552 2553 Define this in order to add variables describing certain 2554 run-time determined information about the hardware to the 2555 environment. These will be named board_name, board_rev. 2556 2557 CONFIG_DELAY_ENVIRONMENT 2558 2559 Normally the environment is loaded when the board is 2560 intialised so that it is available to U-Boot. This inhibits 2561 that so that the environment is not available until 2562 explicitly loaded later by U-Boot code. With CONFIG_OF_CONTROL 2563 this is instead controlled by the value of 2564 /config/load-environment. 2565 2566- DataFlash Support: 2567 CONFIG_HAS_DATAFLASH 2568 2569 Defining this option enables DataFlash features and 2570 allows to read/write in Dataflash via the standard 2571 commands cp, md... 2572 2573- Serial Flash support 2574 CONFIG_CMD_SF 2575 2576 Defining this option enables SPI flash commands 2577 'sf probe/read/write/erase/update'. 2578 2579 Usage requires an initial 'probe' to define the serial 2580 flash parameters, followed by read/write/erase/update 2581 commands. 2582 2583 The following defaults may be provided by the platform 2584 to handle the common case when only a single serial 2585 flash is present on the system. 2586 2587 CONFIG_SF_DEFAULT_BUS Bus identifier 2588 CONFIG_SF_DEFAULT_CS Chip-select 2589 CONFIG_SF_DEFAULT_MODE (see include/spi.h) 2590 CONFIG_SF_DEFAULT_SPEED in Hz 2591 2592 CONFIG_CMD_SF_TEST 2593 2594 Define this option to include a destructive SPI flash 2595 test ('sf test'). 2596 2597 CONFIG_SPI_FLASH_BAR Ban/Extended Addr Reg 2598 2599 Define this option to use the Bank addr/Extended addr 2600 support on SPI flashes which has size > 16Mbytes. 2601 2602- SystemACE Support: 2603 CONFIG_SYSTEMACE 2604 2605 Adding this option adds support for Xilinx SystemACE 2606 chips attached via some sort of local bus. The address 2607 of the chip must also be defined in the 2608 CONFIG_SYS_SYSTEMACE_BASE macro. For example: 2609 2610 #define CONFIG_SYSTEMACE 2611 #define CONFIG_SYS_SYSTEMACE_BASE 0xf0000000 2612 2613 When SystemACE support is added, the "ace" device type 2614 becomes available to the fat commands, i.e. fatls. 2615 2616- TFTP Fixed UDP Port: 2617 CONFIG_TFTP_PORT 2618 2619 If this is defined, the environment variable tftpsrcp 2620 is used to supply the TFTP UDP source port value. 2621 If tftpsrcp isn't defined, the normal pseudo-random port 2622 number generator is used. 2623 2624 Also, the environment variable tftpdstp is used to supply 2625 the TFTP UDP destination port value. If tftpdstp isn't 2626 defined, the normal port 69 is used. 2627 2628 The purpose for tftpsrcp is to allow a TFTP server to 2629 blindly start the TFTP transfer using the pre-configured 2630 target IP address and UDP port. This has the effect of 2631 "punching through" the (Windows XP) firewall, allowing 2632 the remainder of the TFTP transfer to proceed normally. 2633 A better solution is to properly configure the firewall, 2634 but sometimes that is not allowed. 2635 2636- Hashing support: 2637 CONFIG_CMD_HASH 2638 2639 This enables a generic 'hash' command which can produce 2640 hashes / digests from a few algorithms (e.g. SHA1, SHA256). 2641 2642 CONFIG_HASH_VERIFY 2643 2644 Enable the hash verify command (hash -v). This adds to code 2645 size a little. 2646 2647 CONFIG_SHA1 - support SHA1 hashing 2648 CONFIG_SHA256 - support SHA256 hashing 2649 2650 Note: There is also a sha1sum command, which should perhaps 2651 be deprecated in favour of 'hash sha1'. 2652 2653- Freescale i.MX specific commands: 2654 CONFIG_CMD_HDMIDETECT 2655 This enables 'hdmidet' command which returns true if an 2656 HDMI monitor is detected. This command is i.MX 6 specific. 2657 2658 CONFIG_CMD_BMODE 2659 This enables the 'bmode' (bootmode) command for forcing 2660 a boot from specific media. 2661 2662 This is useful for forcing the ROM's usb downloader to 2663 activate upon a watchdog reset which is nice when iterating 2664 on U-Boot. Using the reset button or running bmode normal 2665 will set it back to normal. This command currently 2666 supports i.MX53 and i.MX6. 2667 2668- Signing support: 2669 CONFIG_RSA 2670 2671 This enables the RSA algorithm used for FIT image verification 2672 in U-Boot. See doc/uImage/signature for more information. 2673 2674 The signing part is build into mkimage regardless of this 2675 option. 2676 2677 2678- Show boot progress: 2679 CONFIG_SHOW_BOOT_PROGRESS 2680 2681 Defining this option allows to add some board- 2682 specific code (calling a user-provided function 2683 "show_boot_progress(int)") that enables you to show 2684 the system's boot progress on some display (for 2685 example, some LED's) on your board. At the moment, 2686 the following checkpoints are implemented: 2687 2688- Detailed boot stage timing 2689 CONFIG_BOOTSTAGE 2690 Define this option to get detailed timing of each stage 2691 of the boot process. 2692 2693 CONFIG_BOOTSTAGE_USER_COUNT 2694 This is the number of available user bootstage records. 2695 Each time you call bootstage_mark(BOOTSTAGE_ID_ALLOC, ...) 2696 a new ID will be allocated from this stash. If you exceed 2697 the limit, recording will stop. 2698 2699 CONFIG_BOOTSTAGE_REPORT 2700 Define this to print a report before boot, similar to this: 2701 2702 Timer summary in microseconds: 2703 Mark Elapsed Stage 2704 0 0 reset 2705 3,575,678 3,575,678 board_init_f start 2706 3,575,695 17 arch_cpu_init A9 2707 3,575,777 82 arch_cpu_init done 2708 3,659,598 83,821 board_init_r start 2709 3,910,375 250,777 main_loop 2710 29,916,167 26,005,792 bootm_start 2711 30,361,327 445,160 start_kernel 2712 2713 CONFIG_CMD_BOOTSTAGE 2714 Add a 'bootstage' command which supports printing a report 2715 and un/stashing of bootstage data. 2716 2717 CONFIG_BOOTSTAGE_FDT 2718 Stash the bootstage information in the FDT. A root 'bootstage' 2719 node is created with each bootstage id as a child. Each child 2720 has a 'name' property and either 'mark' containing the 2721 mark time in microsecond, or 'accum' containing the 2722 accumulated time for that bootstage id in microseconds. 2723 For example: 2724 2725 bootstage { 2726 154 { 2727 name = "board_init_f"; 2728 mark = <3575678>; 2729 }; 2730 170 { 2731 name = "lcd"; 2732 accum = <33482>; 2733 }; 2734 }; 2735 2736 Code in the Linux kernel can find this in /proc/devicetree. 2737 2738Legacy uImage format: 2739 2740 Arg Where When 2741 1 common/cmd_bootm.c before attempting to boot an image 2742 -1 common/cmd_bootm.c Image header has bad magic number 2743 2 common/cmd_bootm.c Image header has correct magic number 2744 -2 common/cmd_bootm.c Image header has bad checksum 2745 3 common/cmd_bootm.c Image header has correct checksum 2746 -3 common/cmd_bootm.c Image data has bad checksum 2747 4 common/cmd_bootm.c Image data has correct checksum 2748 -4 common/cmd_bootm.c Image is for unsupported architecture 2749 5 common/cmd_bootm.c Architecture check OK 2750 -5 common/cmd_bootm.c Wrong Image Type (not kernel, multi) 2751 6 common/cmd_bootm.c Image Type check OK 2752 -6 common/cmd_bootm.c gunzip uncompression error 2753 -7 common/cmd_bootm.c Unimplemented compression type 2754 7 common/cmd_bootm.c Uncompression OK 2755 8 common/cmd_bootm.c No uncompress/copy overwrite error 2756 -9 common/cmd_bootm.c Unsupported OS (not Linux, BSD, VxWorks, QNX) 2757 2758 9 common/image.c Start initial ramdisk verification 2759 -10 common/image.c Ramdisk header has bad magic number 2760 -11 common/image.c Ramdisk header has bad checksum 2761 10 common/image.c Ramdisk header is OK 2762 -12 common/image.c Ramdisk data has bad checksum 2763 11 common/image.c Ramdisk data has correct checksum 2764 12 common/image.c Ramdisk verification complete, start loading 2765 -13 common/image.c Wrong Image Type (not PPC Linux ramdisk) 2766 13 common/image.c Start multifile image verification 2767 14 common/image.c No initial ramdisk, no multifile, continue. 2768 2769 15 arch/<arch>/lib/bootm.c All preparation done, transferring control to OS 2770 2771 -30 arch/powerpc/lib/board.c Fatal error, hang the system 2772 -31 post/post.c POST test failed, detected by post_output_backlog() 2773 -32 post/post.c POST test failed, detected by post_run_single() 2774 2775 34 common/cmd_doc.c before loading a Image from a DOC device 2776 -35 common/cmd_doc.c Bad usage of "doc" command 2777 35 common/cmd_doc.c correct usage of "doc" command 2778 -36 common/cmd_doc.c No boot device 2779 36 common/cmd_doc.c correct boot device 2780 -37 common/cmd_doc.c Unknown Chip ID on boot device 2781 37 common/cmd_doc.c correct chip ID found, device available 2782 -38 common/cmd_doc.c Read Error on boot device 2783 38 common/cmd_doc.c reading Image header from DOC device OK 2784 -39 common/cmd_doc.c Image header has bad magic number 2785 39 common/cmd_doc.c Image header has correct magic number 2786 -40 common/cmd_doc.c Error reading Image from DOC device 2787 40 common/cmd_doc.c Image header has correct magic number 2788 41 common/cmd_ide.c before loading a Image from a IDE device 2789 -42 common/cmd_ide.c Bad usage of "ide" command 2790 42 common/cmd_ide.c correct usage of "ide" command 2791 -43 common/cmd_ide.c No boot device 2792 43 common/cmd_ide.c boot device found 2793 -44 common/cmd_ide.c Device not available 2794 44 common/cmd_ide.c Device available 2795 -45 common/cmd_ide.c wrong partition selected 2796 45 common/cmd_ide.c partition selected 2797 -46 common/cmd_ide.c Unknown partition table 2798 46 common/cmd_ide.c valid partition table found 2799 -47 common/cmd_ide.c Invalid partition type 2800 47 common/cmd_ide.c correct partition type 2801 -48 common/cmd_ide.c Error reading Image Header on boot device 2802 48 common/cmd_ide.c reading Image Header from IDE device OK 2803 -49 common/cmd_ide.c Image header has bad magic number 2804 49 common/cmd_ide.c Image header has correct magic number 2805 -50 common/cmd_ide.c Image header has bad checksum 2806 50 common/cmd_ide.c Image header has correct checksum 2807 -51 common/cmd_ide.c Error reading Image from IDE device 2808 51 common/cmd_ide.c reading Image from IDE device OK 2809 52 common/cmd_nand.c before loading a Image from a NAND device 2810 -53 common/cmd_nand.c Bad usage of "nand" command 2811 53 common/cmd_nand.c correct usage of "nand" command 2812 -54 common/cmd_nand.c No boot device 2813 54 common/cmd_nand.c boot device found 2814 -55 common/cmd_nand.c Unknown Chip ID on boot device 2815 55 common/cmd_nand.c correct chip ID found, device available 2816 -56 common/cmd_nand.c Error reading Image Header on boot device 2817 56 common/cmd_nand.c reading Image Header from NAND device OK 2818 -57 common/cmd_nand.c Image header has bad magic number 2819 57 common/cmd_nand.c Image header has correct magic number 2820 -58 common/cmd_nand.c Error reading Image from NAND device 2821 58 common/cmd_nand.c reading Image from NAND device OK 2822 2823 -60 common/env_common.c Environment has a bad CRC, using default 2824 2825 64 net/eth.c starting with Ethernet configuration. 2826 -64 net/eth.c no Ethernet found. 2827 65 net/eth.c Ethernet found. 2828 2829 -80 common/cmd_net.c usage wrong 2830 80 common/cmd_net.c before calling NetLoop() 2831 -81 common/cmd_net.c some error in NetLoop() occurred 2832 81 common/cmd_net.c NetLoop() back without error 2833 -82 common/cmd_net.c size == 0 (File with size 0 loaded) 2834 82 common/cmd_net.c trying automatic boot 2835 83 common/cmd_net.c running "source" command 2836 -83 common/cmd_net.c some error in automatic boot or "source" command 2837 84 common/cmd_net.c end without errors 2838 2839FIT uImage format: 2840 2841 Arg Where When 2842 100 common/cmd_bootm.c Kernel FIT Image has correct format 2843 -100 common/cmd_bootm.c Kernel FIT Image has incorrect format 2844 101 common/cmd_bootm.c No Kernel subimage unit name, using configuration 2845 -101 common/cmd_bootm.c Can't get configuration for kernel subimage 2846 102 common/cmd_bootm.c Kernel unit name specified 2847 -103 common/cmd_bootm.c Can't get kernel subimage node offset 2848 103 common/cmd_bootm.c Found configuration node 2849 104 common/cmd_bootm.c Got kernel subimage node offset 2850 -104 common/cmd_bootm.c Kernel subimage hash verification failed 2851 105 common/cmd_bootm.c Kernel subimage hash verification OK 2852 -105 common/cmd_bootm.c Kernel subimage is for unsupported architecture 2853 106 common/cmd_bootm.c Architecture check OK 2854 -106 common/cmd_bootm.c Kernel subimage has wrong type 2855 107 common/cmd_bootm.c Kernel subimage type OK 2856 -107 common/cmd_bootm.c Can't get kernel subimage data/size 2857 108 common/cmd_bootm.c Got kernel subimage data/size 2858 -108 common/cmd_bootm.c Wrong image type (not legacy, FIT) 2859 -109 common/cmd_bootm.c Can't get kernel subimage type 2860 -110 common/cmd_bootm.c Can't get kernel subimage comp 2861 -111 common/cmd_bootm.c Can't get kernel subimage os 2862 -112 common/cmd_bootm.c Can't get kernel subimage load address 2863 -113 common/cmd_bootm.c Image uncompress/copy overwrite error 2864 2865 120 common/image.c Start initial ramdisk verification 2866 -120 common/image.c Ramdisk FIT image has incorrect format 2867 121 common/image.c Ramdisk FIT image has correct format 2868 122 common/image.c No ramdisk subimage unit name, using configuration 2869 -122 common/image.c Can't get configuration for ramdisk subimage 2870 123 common/image.c Ramdisk unit name specified 2871 -124 common/image.c Can't get ramdisk subimage node offset 2872 125 common/image.c Got ramdisk subimage node offset 2873 -125 common/image.c Ramdisk subimage hash verification failed 2874 126 common/image.c Ramdisk subimage hash verification OK 2875 -126 common/image.c Ramdisk subimage for unsupported architecture 2876 127 common/image.c Architecture check OK 2877 -127 common/image.c Can't get ramdisk subimage data/size 2878 128 common/image.c Got ramdisk subimage data/size 2879 129 common/image.c Can't get ramdisk load address 2880 -129 common/image.c Got ramdisk load address 2881 2882 -130 common/cmd_doc.c Incorrect FIT image format 2883 131 common/cmd_doc.c FIT image format OK 2884 2885 -140 common/cmd_ide.c Incorrect FIT image format 2886 141 common/cmd_ide.c FIT image format OK 2887 2888 -150 common/cmd_nand.c Incorrect FIT image format 2889 151 common/cmd_nand.c FIT image format OK 2890 2891- FIT image support: 2892 CONFIG_FIT 2893 Enable support for the FIT uImage format. 2894 2895 CONFIG_FIT_BEST_MATCH 2896 When no configuration is explicitly selected, default to the 2897 one whose fdt's compatibility field best matches that of 2898 U-Boot itself. A match is considered "best" if it matches the 2899 most specific compatibility entry of U-Boot's fdt's root node. 2900 The order of entries in the configuration's fdt is ignored. 2901 2902 CONFIG_FIT_SIGNATURE 2903 This option enables signature verification of FIT uImages, 2904 using a hash signed and verified using RSA. See 2905 doc/uImage.FIT/signature.txt for more details. 2906 2907- Standalone program support: 2908 CONFIG_STANDALONE_LOAD_ADDR 2909 2910 This option defines a board specific value for the 2911 address where standalone program gets loaded, thus 2912 overwriting the architecture dependent default 2913 settings. 2914 2915- Frame Buffer Address: 2916 CONFIG_FB_ADDR 2917 2918 Define CONFIG_FB_ADDR if you want to use specific 2919 address for frame buffer. This is typically the case 2920 when using a graphics controller has separate video 2921 memory. U-Boot will then place the frame buffer at 2922 the given address instead of dynamically reserving it 2923 in system RAM by calling lcd_setmem(), which grabs 2924 the memory for the frame buffer depending on the 2925 configured panel size. 2926 2927 Please see board_init_f function. 2928 2929- Automatic software updates via TFTP server 2930 CONFIG_UPDATE_TFTP 2931 CONFIG_UPDATE_TFTP_CNT_MAX 2932 CONFIG_UPDATE_TFTP_MSEC_MAX 2933 2934 These options enable and control the auto-update feature; 2935 for a more detailed description refer to doc/README.update. 2936 2937- MTD Support (mtdparts command, UBI support) 2938 CONFIG_MTD_DEVICE 2939 2940 Adds the MTD device infrastructure from the Linux kernel. 2941 Needed for mtdparts command support. 2942 2943 CONFIG_MTD_PARTITIONS 2944 2945 Adds the MTD partitioning infrastructure from the Linux 2946 kernel. Needed for UBI support. 2947 2948- UBI support 2949 CONFIG_CMD_UBI 2950 2951 Adds commands for interacting with MTD partitions formatted 2952 with the UBI flash translation layer 2953 2954 Requires also defining CONFIG_RBTREE 2955 2956 CONFIG_UBI_SILENCE_MSG 2957 2958 Make the verbose messages from UBI stop printing. This leaves 2959 warnings and errors enabled. 2960 2961- UBIFS support 2962 CONFIG_CMD_UBIFS 2963 2964 Adds commands for interacting with UBI volumes formatted as 2965 UBIFS. UBIFS is read-only in u-boot. 2966 2967 Requires UBI support as well as CONFIG_LZO 2968 2969 CONFIG_UBIFS_SILENCE_MSG 2970 2971 Make the verbose messages from UBIFS stop printing. This leaves 2972 warnings and errors enabled. 2973 2974- SPL framework 2975 CONFIG_SPL 2976 Enable building of SPL globally. 2977 2978 CONFIG_SPL_LDSCRIPT 2979 LDSCRIPT for linking the SPL binary. 2980 2981 CONFIG_SPL_MAX_FOOTPRINT 2982 Maximum size in memory allocated to the SPL, BSS included. 2983 When defined, the linker checks that the actual memory 2984 used by SPL from _start to __bss_end does not exceed it. 2985 CONFIG_SPL_MAX_FOOTPRINT and CONFIG_SPL_BSS_MAX_SIZE 2986 must not be both defined at the same time. 2987 2988 CONFIG_SPL_MAX_SIZE 2989 Maximum size of the SPL image (text, data, rodata, and 2990 linker lists sections), BSS excluded. 2991 When defined, the linker checks that the actual size does 2992 not exceed it. 2993 2994 CONFIG_SPL_TEXT_BASE 2995 TEXT_BASE for linking the SPL binary. 2996 2997 CONFIG_SPL_RELOC_TEXT_BASE 2998 Address to relocate to. If unspecified, this is equal to 2999 CONFIG_SPL_TEXT_BASE (i.e. no relocation is done). 3000 3001 CONFIG_SPL_BSS_START_ADDR 3002 Link address for the BSS within the SPL binary. 3003 3004 CONFIG_SPL_BSS_MAX_SIZE 3005 Maximum size in memory allocated to the SPL BSS. 3006 When defined, the linker checks that the actual memory used 3007 by SPL from __bss_start to __bss_end does not exceed it. 3008 CONFIG_SPL_MAX_FOOTPRINT and CONFIG_SPL_BSS_MAX_SIZE 3009 must not be both defined at the same time. 3010 3011 CONFIG_SPL_STACK 3012 Adress of the start of the stack SPL will use 3013 3014 CONFIG_SPL_RELOC_STACK 3015 Adress of the start of the stack SPL will use after 3016 relocation. If unspecified, this is equal to 3017 CONFIG_SPL_STACK. 3018 3019 CONFIG_SYS_SPL_MALLOC_START 3020 Starting address of the malloc pool used in SPL. 3021 3022 CONFIG_SYS_SPL_MALLOC_SIZE 3023 The size of the malloc pool used in SPL. 3024 3025 CONFIG_SPL_FRAMEWORK 3026 Enable the SPL framework under common/. This framework 3027 supports MMC, NAND and YMODEM loading of U-Boot and NAND 3028 NAND loading of the Linux Kernel. 3029 3030 CONFIG_SPL_DISPLAY_PRINT 3031 For ARM, enable an optional function to print more information 3032 about the running system. 3033 3034 CONFIG_SPL_INIT_MINIMAL 3035 Arch init code should be built for a very small image 3036 3037 CONFIG_SPL_LIBCOMMON_SUPPORT 3038 Support for common/libcommon.o in SPL binary 3039 3040 CONFIG_SPL_LIBDISK_SUPPORT 3041 Support for disk/libdisk.o in SPL binary 3042 3043 CONFIG_SPL_I2C_SUPPORT 3044 Support for drivers/i2c/libi2c.o in SPL binary 3045 3046 CONFIG_SPL_GPIO_SUPPORT 3047 Support for drivers/gpio/libgpio.o in SPL binary 3048 3049 CONFIG_SPL_MMC_SUPPORT 3050 Support for drivers/mmc/libmmc.o in SPL binary 3051 3052 CONFIG_SYS_MMCSD_RAW_MODE_U_BOOT_SECTOR, 3053 CONFIG_SYS_U_BOOT_MAX_SIZE_SECTORS, 3054 CONFIG_SYS_MMC_SD_FAT_BOOT_PARTITION 3055 Address, size and partition on the MMC to load U-Boot from 3056 when the MMC is being used in raw mode. 3057 3058 CONFIG_SYS_MMCSD_RAW_MODE_KERNEL_SECTOR 3059 Sector to load kernel uImage from when MMC is being 3060 used in raw mode (for Falcon mode) 3061 3062 CONFIG_SYS_MMCSD_RAW_MODE_ARGS_SECTOR, 3063 CONFIG_SYS_MMCSD_RAW_MODE_ARGS_SECTORS 3064 Sector and number of sectors to load kernel argument 3065 parameters from when MMC is being used in raw mode 3066 (for falcon mode) 3067 3068 CONFIG_SPL_FAT_SUPPORT 3069 Support for fs/fat/libfat.o in SPL binary 3070 3071 CONFIG_SPL_FAT_LOAD_PAYLOAD_NAME 3072 Filename to read to load U-Boot when reading from FAT 3073 3074 CONFIG_SPL_FAT_LOAD_KERNEL_NAME 3075 Filename to read to load kernel uImage when reading 3076 from FAT (for Falcon mode) 3077 3078 CONFIG_SPL_FAT_LOAD_ARGS_NAME 3079 Filename to read to load kernel argument parameters 3080 when reading from FAT (for Falcon mode) 3081 3082 CONFIG_SPL_MPC83XX_WAIT_FOR_NAND 3083 Set this for NAND SPL on PPC mpc83xx targets, so that 3084 start.S waits for the rest of the SPL to load before 3085 continuing (the hardware starts execution after just 3086 loading the first page rather than the full 4K). 3087 3088 CONFIG_SPL_NAND_BASE 3089 Include nand_base.c in the SPL. Requires 3090 CONFIG_SPL_NAND_DRIVERS. 3091 3092 CONFIG_SPL_NAND_DRIVERS 3093 SPL uses normal NAND drivers, not minimal drivers. 3094 3095 CONFIG_SPL_NAND_ECC 3096 Include standard software ECC in the SPL 3097 3098 CONFIG_SPL_NAND_SIMPLE 3099 Support for NAND boot using simple NAND drivers that 3100 expose the cmd_ctrl() interface. 3101 3102 CONFIG_SPL_MPC8XXX_INIT_DDR_SUPPORT 3103 Set for the SPL on PPC mpc8xxx targets, support for 3104 arch/powerpc/cpu/mpc8xxx/ddr/libddr.o in SPL binary. 3105 3106 CONFIG_SPL_COMMON_INIT_DDR 3107 Set for common ddr init with serial presence detect in 3108 SPL binary. 3109 3110 CONFIG_SYS_NAND_5_ADDR_CYCLE, CONFIG_SYS_NAND_PAGE_COUNT, 3111 CONFIG_SYS_NAND_PAGE_SIZE, CONFIG_SYS_NAND_OOBSIZE, 3112 CONFIG_SYS_NAND_BLOCK_SIZE, CONFIG_SYS_NAND_BAD_BLOCK_POS, 3113 CONFIG_SYS_NAND_ECCPOS, CONFIG_SYS_NAND_ECCSIZE, 3114 CONFIG_SYS_NAND_ECCBYTES 3115 Defines the size and behavior of the NAND that SPL uses 3116 to read U-Boot 3117 3118 CONFIG_SYS_NAND_U_BOOT_OFFS 3119 Location in NAND to read U-Boot from 3120 3121 CONFIG_SYS_NAND_U_BOOT_DST 3122 Location in memory to load U-Boot to 3123 3124 CONFIG_SYS_NAND_U_BOOT_SIZE 3125 Size of image to load 3126 3127 CONFIG_SYS_NAND_U_BOOT_START 3128 Entry point in loaded image to jump to 3129 3130 CONFIG_SYS_NAND_HW_ECC_OOBFIRST 3131 Define this if you need to first read the OOB and then the 3132 data. This is used for example on davinci plattforms. 3133 3134 CONFIG_SPL_OMAP3_ID_NAND 3135 Support for an OMAP3-specific set of functions to return the 3136 ID and MFR of the first attached NAND chip, if present. 3137 3138 CONFIG_SPL_SERIAL_SUPPORT 3139 Support for drivers/serial/libserial.o in SPL binary 3140 3141 CONFIG_SPL_SPI_FLASH_SUPPORT 3142 Support for drivers/mtd/spi/libspi_flash.o in SPL binary 3143 3144 CONFIG_SPL_SPI_SUPPORT 3145 Support for drivers/spi/libspi.o in SPL binary 3146 3147 CONFIG_SPL_RAM_DEVICE 3148 Support for running image already present in ram, in SPL binary 3149 3150 CONFIG_SPL_LIBGENERIC_SUPPORT 3151 Support for lib/libgeneric.o in SPL binary 3152 3153 CONFIG_SPL_ENV_SUPPORT 3154 Support for the environment operating in SPL binary 3155 3156 CONFIG_SPL_NET_SUPPORT 3157 Support for the net/libnet.o in SPL binary. 3158 It conflicts with SPL env from storage medium specified by 3159 CONFIG_ENV_IS_xxx but CONFIG_ENV_IS_NOWHERE 3160 3161 CONFIG_SPL_PAD_TO 3162 Image offset to which the SPL should be padded before appending 3163 the SPL payload. By default, this is defined as 3164 CONFIG_SPL_MAX_SIZE, or 0 if CONFIG_SPL_MAX_SIZE is undefined. 3165 CONFIG_SPL_PAD_TO must be either 0, meaning to append the SPL 3166 payload without any padding, or >= CONFIG_SPL_MAX_SIZE. 3167 3168 CONFIG_SPL_TARGET 3169 Final target image containing SPL and payload. Some SPLs 3170 use an arch-specific makefile fragment instead, for 3171 example if more than one image needs to be produced. 3172 3173 CONFIG_FIT_SPL_PRINT 3174 Printing information about a FIT image adds quite a bit of 3175 code to SPL. So this is normally disabled in SPL. Use this 3176 option to re-enable it. This will affect the output of the 3177 bootm command when booting a FIT image. 3178 3179- TPL framework 3180 CONFIG_TPL 3181 Enable building of TPL globally. 3182 3183 CONFIG_TPL_PAD_TO 3184 Image offset to which the TPL should be padded before appending 3185 the TPL payload. By default, this is defined as 3186 CONFIG_SPL_MAX_SIZE, or 0 if CONFIG_SPL_MAX_SIZE is undefined. 3187 CONFIG_SPL_PAD_TO must be either 0, meaning to append the SPL 3188 payload without any padding, or >= CONFIG_SPL_MAX_SIZE. 3189 3190Modem Support: 3191-------------- 3192 3193[so far only for SMDK2400 boards] 3194 3195- Modem support enable: 3196 CONFIG_MODEM_SUPPORT 3197 3198- RTS/CTS Flow control enable: 3199 CONFIG_HWFLOW 3200 3201- Modem debug support: 3202 CONFIG_MODEM_SUPPORT_DEBUG 3203 3204 Enables debugging stuff (char screen[1024], dbg()) 3205 for modem support. Useful only with BDI2000. 3206 3207- Interrupt support (PPC): 3208 3209 There are common interrupt_init() and timer_interrupt() 3210 for all PPC archs. interrupt_init() calls interrupt_init_cpu() 3211 for CPU specific initialization. interrupt_init_cpu() 3212 should set decrementer_count to appropriate value. If 3213 CPU resets decrementer automatically after interrupt 3214 (ppc4xx) it should set decrementer_count to zero. 3215 timer_interrupt() calls timer_interrupt_cpu() for CPU 3216 specific handling. If board has watchdog / status_led 3217 / other_activity_monitor it works automatically from 3218 general timer_interrupt(). 3219 3220- General: 3221 3222 In the target system modem support is enabled when a 3223 specific key (key combination) is pressed during 3224 power-on. Otherwise U-Boot will boot normally 3225 (autoboot). The key_pressed() function is called from 3226 board_init(). Currently key_pressed() is a dummy 3227 function, returning 1 and thus enabling modem 3228 initialization. 3229 3230 If there are no modem init strings in the 3231 environment, U-Boot proceed to autoboot; the 3232 previous output (banner, info printfs) will be 3233 suppressed, though. 3234 3235 See also: doc/README.Modem 3236 3237Board initialization settings: 3238------------------------------ 3239 3240During Initialization u-boot calls a number of board specific functions 3241to allow the preparation of board specific prerequisites, e.g. pin setup 3242before drivers are initialized. To enable these callbacks the 3243following configuration macros have to be defined. Currently this is 3244architecture specific, so please check arch/your_architecture/lib/board.c 3245typically in board_init_f() and board_init_r(). 3246 3247- CONFIG_BOARD_EARLY_INIT_F: Call board_early_init_f() 3248- CONFIG_BOARD_EARLY_INIT_R: Call board_early_init_r() 3249- CONFIG_BOARD_LATE_INIT: Call board_late_init() 3250- CONFIG_BOARD_POSTCLK_INIT: Call board_postclk_init() 3251 3252Configuration Settings: 3253----------------------- 3254 3255- CONFIG_SYS_LONGHELP: Defined when you want long help messages included; 3256 undefine this when you're short of memory. 3257 3258- CONFIG_SYS_HELP_CMD_WIDTH: Defined when you want to override the default 3259 width of the commands listed in the 'help' command output. 3260 3261- CONFIG_SYS_PROMPT: This is what U-Boot prints on the console to 3262 prompt for user input. 3263 3264- CONFIG_SYS_CBSIZE: Buffer size for input from the Console 3265 3266- CONFIG_SYS_PBSIZE: Buffer size for Console output 3267 3268- CONFIG_SYS_MAXARGS: max. Number of arguments accepted for monitor commands 3269 3270- CONFIG_SYS_BARGSIZE: Buffer size for Boot Arguments which are passed to 3271 the application (usually a Linux kernel) when it is 3272 booted 3273 3274- CONFIG_SYS_BAUDRATE_TABLE: 3275 List of legal baudrate settings for this board. 3276 3277- CONFIG_SYS_CONSOLE_INFO_QUIET 3278 Suppress display of console information at boot. 3279 3280- CONFIG_SYS_CONSOLE_IS_IN_ENV 3281 If the board specific function 3282 extern int overwrite_console (void); 3283 returns 1, the stdin, stderr and stdout are switched to the 3284 serial port, else the settings in the environment are used. 3285 3286- CONFIG_SYS_CONSOLE_OVERWRITE_ROUTINE 3287 Enable the call to overwrite_console(). 3288 3289- CONFIG_SYS_CONSOLE_ENV_OVERWRITE 3290 Enable overwrite of previous console environment settings. 3291 3292- CONFIG_SYS_MEMTEST_START, CONFIG_SYS_MEMTEST_END: 3293 Begin and End addresses of the area used by the 3294 simple memory test. 3295 3296- CONFIG_SYS_ALT_MEMTEST: 3297 Enable an alternate, more extensive memory test. 3298 3299- CONFIG_SYS_MEMTEST_SCRATCH: 3300 Scratch address used by the alternate memory test 3301 You only need to set this if address zero isn't writeable 3302 3303- CONFIG_SYS_MEM_TOP_HIDE (PPC only): 3304 If CONFIG_SYS_MEM_TOP_HIDE is defined in the board config header, 3305 this specified memory area will get subtracted from the top 3306 (end) of RAM and won't get "touched" at all by U-Boot. By 3307 fixing up gd->ram_size the Linux kernel should gets passed 3308 the now "corrected" memory size and won't touch it either. 3309 This should work for arch/ppc and arch/powerpc. Only Linux 3310 board ports in arch/powerpc with bootwrapper support that 3311 recalculate the memory size from the SDRAM controller setup 3312 will have to get fixed in Linux additionally. 3313 3314 This option can be used as a workaround for the 440EPx/GRx 3315 CHIP 11 errata where the last 256 bytes in SDRAM shouldn't 3316 be touched. 3317 3318 WARNING: Please make sure that this value is a multiple of 3319 the Linux page size (normally 4k). If this is not the case, 3320 then the end address of the Linux memory will be located at a 3321 non page size aligned address and this could cause major 3322 problems. 3323 3324- CONFIG_SYS_LOADS_BAUD_CHANGE: 3325 Enable temporary baudrate change while serial download 3326 3327- CONFIG_SYS_SDRAM_BASE: 3328 Physical start address of SDRAM. _Must_ be 0 here. 3329 3330- CONFIG_SYS_MBIO_BASE: 3331 Physical start address of Motherboard I/O (if using a 3332 Cogent motherboard) 3333 3334- CONFIG_SYS_FLASH_BASE: 3335 Physical start address of Flash memory. 3336 3337- CONFIG_SYS_MONITOR_BASE: 3338 Physical start address of boot monitor code (set by 3339 make config files to be same as the text base address 3340 (CONFIG_SYS_TEXT_BASE) used when linking) - same as 3341 CONFIG_SYS_FLASH_BASE when booting from flash. 3342 3343- CONFIG_SYS_MONITOR_LEN: 3344 Size of memory reserved for monitor code, used to 3345 determine _at_compile_time_ (!) if the environment is 3346 embedded within the U-Boot image, or in a separate 3347 flash sector. 3348 3349- CONFIG_SYS_MALLOC_LEN: 3350 Size of DRAM reserved for malloc() use. 3351 3352- CONFIG_SYS_BOOTM_LEN: 3353 Normally compressed uImages are limited to an 3354 uncompressed size of 8 MBytes. If this is not enough, 3355 you can define CONFIG_SYS_BOOTM_LEN in your board config file 3356 to adjust this setting to your needs. 3357 3358- CONFIG_SYS_BOOTMAPSZ: 3359 Maximum size of memory mapped by the startup code of 3360 the Linux kernel; all data that must be processed by 3361 the Linux kernel (bd_info, boot arguments, FDT blob if 3362 used) must be put below this limit, unless "bootm_low" 3363 enviroment variable is defined and non-zero. In such case 3364 all data for the Linux kernel must be between "bootm_low" 3365 and "bootm_low" + CONFIG_SYS_BOOTMAPSZ. The environment 3366 variable "bootm_mapsize" will override the value of 3367 CONFIG_SYS_BOOTMAPSZ. If CONFIG_SYS_BOOTMAPSZ is undefined, 3368 then the value in "bootm_size" will be used instead. 3369 3370- CONFIG_SYS_BOOT_RAMDISK_HIGH: 3371 Enable initrd_high functionality. If defined then the 3372 initrd_high feature is enabled and the bootm ramdisk subcommand 3373 is enabled. 3374 3375- CONFIG_SYS_BOOT_GET_CMDLINE: 3376 Enables allocating and saving kernel cmdline in space between 3377 "bootm_low" and "bootm_low" + BOOTMAPSZ. 3378 3379- CONFIG_SYS_BOOT_GET_KBD: 3380 Enables allocating and saving a kernel copy of the bd_info in 3381 space between "bootm_low" and "bootm_low" + BOOTMAPSZ. 3382 3383- CONFIG_SYS_MAX_FLASH_BANKS: 3384 Max number of Flash memory banks 3385 3386- CONFIG_SYS_MAX_FLASH_SECT: 3387 Max number of sectors on a Flash chip 3388 3389- CONFIG_SYS_FLASH_ERASE_TOUT: 3390 Timeout for Flash erase operations (in ms) 3391 3392- CONFIG_SYS_FLASH_WRITE_TOUT: 3393 Timeout for Flash write operations (in ms) 3394 3395- CONFIG_SYS_FLASH_LOCK_TOUT 3396 Timeout for Flash set sector lock bit operation (in ms) 3397 3398- CONFIG_SYS_FLASH_UNLOCK_TOUT 3399 Timeout for Flash clear lock bits operation (in ms) 3400 3401- CONFIG_SYS_FLASH_PROTECTION 3402 If defined, hardware flash sectors protection is used 3403 instead of U-Boot software protection. 3404 3405- CONFIG_SYS_DIRECT_FLASH_TFTP: 3406 3407 Enable TFTP transfers directly to flash memory; 3408 without this option such a download has to be 3409 performed in two steps: (1) download to RAM, and (2) 3410 copy from RAM to flash. 3411 3412 The two-step approach is usually more reliable, since 3413 you can check if the download worked before you erase 3414 the flash, but in some situations (when system RAM is 3415 too limited to allow for a temporary copy of the 3416 downloaded image) this option may be very useful. 3417 3418- CONFIG_SYS_FLASH_CFI: 3419 Define if the flash driver uses extra elements in the 3420 common flash structure for storing flash geometry. 3421 3422- CONFIG_FLASH_CFI_DRIVER 3423 This option also enables the building of the cfi_flash driver 3424 in the drivers directory 3425 3426- CONFIG_FLASH_CFI_MTD 3427 This option enables the building of the cfi_mtd driver 3428 in the drivers directory. The driver exports CFI flash 3429 to the MTD layer. 3430 3431- CONFIG_SYS_FLASH_USE_BUFFER_WRITE 3432 Use buffered writes to flash. 3433 3434- CONFIG_FLASH_SPANSION_S29WS_N 3435 s29ws-n MirrorBit flash has non-standard addresses for buffered 3436 write commands. 3437 3438- CONFIG_SYS_FLASH_QUIET_TEST 3439 If this option is defined, the common CFI flash doesn't 3440 print it's warning upon not recognized FLASH banks. This 3441 is useful, if some of the configured banks are only 3442 optionally available. 3443 3444- CONFIG_FLASH_SHOW_PROGRESS 3445 If defined (must be an integer), print out countdown 3446 digits and dots. Recommended value: 45 (9..1) for 80 3447 column displays, 15 (3..1) for 40 column displays. 3448 3449- CONFIG_FLASH_VERIFY 3450 If defined, the content of the flash (destination) is compared 3451 against the source after the write operation. An error message 3452 will be printed when the contents are not identical. 3453 Please note that this option is useless in nearly all cases, 3454 since such flash programming errors usually are detected earlier 3455 while unprotecting/erasing/programming. Please only enable 3456 this option if you really know what you are doing. 3457 3458- CONFIG_SYS_RX_ETH_BUFFER: 3459 Defines the number of Ethernet receive buffers. On some 3460 Ethernet controllers it is recommended to set this value 3461 to 8 or even higher (EEPRO100 or 405 EMAC), since all 3462 buffers can be full shortly after enabling the interface 3463 on high Ethernet traffic. 3464 Defaults to 4 if not defined. 3465 3466- CONFIG_ENV_MAX_ENTRIES 3467 3468 Maximum number of entries in the hash table that is used 3469 internally to store the environment settings. The default 3470 setting is supposed to be generous and should work in most 3471 cases. This setting can be used to tune behaviour; see 3472 lib/hashtable.c for details. 3473 3474- CONFIG_ENV_FLAGS_LIST_DEFAULT 3475- CONFIG_ENV_FLAGS_LIST_STATIC 3476 Enable validation of the values given to enviroment variables when 3477 calling env set. Variables can be restricted to only decimal, 3478 hexadecimal, or boolean. If CONFIG_CMD_NET is also defined, 3479 the variables can also be restricted to IP address or MAC address. 3480 3481 The format of the list is: 3482 type_attribute = [s|d|x|b|i|m] 3483 access_atribute = [a|r|o|c] 3484 attributes = type_attribute[access_atribute] 3485 entry = variable_name[:attributes] 3486 list = entry[,list] 3487 3488 The type attributes are: 3489 s - String (default) 3490 d - Decimal 3491 x - Hexadecimal 3492 b - Boolean ([1yYtT|0nNfF]) 3493 i - IP address 3494 m - MAC address 3495 3496 The access attributes are: 3497 a - Any (default) 3498 r - Read-only 3499 o - Write-once 3500 c - Change-default 3501 3502 - CONFIG_ENV_FLAGS_LIST_DEFAULT 3503 Define this to a list (string) to define the ".flags" 3504 envirnoment variable in the default or embedded environment. 3505 3506 - CONFIG_ENV_FLAGS_LIST_STATIC 3507 Define this to a list (string) to define validation that 3508 should be done if an entry is not found in the ".flags" 3509 environment variable. To override a setting in the static 3510 list, simply add an entry for the same variable name to the 3511 ".flags" variable. 3512 3513- CONFIG_ENV_ACCESS_IGNORE_FORCE 3514 If defined, don't allow the -f switch to env set override variable 3515 access flags. 3516 3517- CONFIG_SYS_GENERIC_BOARD 3518 This selects the architecture-generic board system instead of the 3519 architecture-specific board files. It is intended to move boards 3520 to this new framework over time. Defining this will disable the 3521 arch/foo/lib/board.c file and use common/board_f.c and 3522 common/board_r.c instead. To use this option your architecture 3523 must support it (i.e. must define __HAVE_ARCH_GENERIC_BOARD in 3524 its config.mk file). If you find problems enabling this option on 3525 your board please report the problem and send patches! 3526 3527- CONFIG_SYS_SYM_OFFSETS 3528 This is set by architectures that use offsets for link symbols 3529 instead of absolute values. So bss_start is obtained using an 3530 offset _bss_start_ofs from CONFIG_SYS_TEXT_BASE, rather than 3531 directly. You should not need to touch this setting. 3532 3533- CONFIG_OMAP_PLATFORM_RESET_TIME_MAX_USEC (OMAP only) 3534 This is set by OMAP boards for the max time that reset should 3535 be asserted. See doc/README.omap-reset-time for details on how 3536 the value can be calulated on a given board. 3537 3538The following definitions that deal with the placement and management 3539of environment data (variable area); in general, we support the 3540following configurations: 3541 3542- CONFIG_BUILD_ENVCRC: 3543 3544 Builds up envcrc with the target environment so that external utils 3545 may easily extract it and embed it in final U-Boot images. 3546 3547- CONFIG_ENV_IS_IN_FLASH: 3548 3549 Define this if the environment is in flash memory. 3550 3551 a) The environment occupies one whole flash sector, which is 3552 "embedded" in the text segment with the U-Boot code. This 3553 happens usually with "bottom boot sector" or "top boot 3554 sector" type flash chips, which have several smaller 3555 sectors at the start or the end. For instance, such a 3556 layout can have sector sizes of 8, 2x4, 16, Nx32 kB. In 3557 such a case you would place the environment in one of the 3558 4 kB sectors - with U-Boot code before and after it. With 3559 "top boot sector" type flash chips, you would put the 3560 environment in one of the last sectors, leaving a gap 3561 between U-Boot and the environment. 3562 3563 - CONFIG_ENV_OFFSET: 3564 3565 Offset of environment data (variable area) to the 3566 beginning of flash memory; for instance, with bottom boot 3567 type flash chips the second sector can be used: the offset 3568 for this sector is given here. 3569 3570 CONFIG_ENV_OFFSET is used relative to CONFIG_SYS_FLASH_BASE. 3571 3572 - CONFIG_ENV_ADDR: 3573 3574 This is just another way to specify the start address of 3575 the flash sector containing the environment (instead of 3576 CONFIG_ENV_OFFSET). 3577 3578 - CONFIG_ENV_SECT_SIZE: 3579 3580 Size of the sector containing the environment. 3581 3582 3583 b) Sometimes flash chips have few, equal sized, BIG sectors. 3584 In such a case you don't want to spend a whole sector for 3585 the environment. 3586 3587 - CONFIG_ENV_SIZE: 3588 3589 If you use this in combination with CONFIG_ENV_IS_IN_FLASH 3590 and CONFIG_ENV_SECT_SIZE, you can specify to use only a part 3591 of this flash sector for the environment. This saves 3592 memory for the RAM copy of the environment. 3593 3594 It may also save flash memory if you decide to use this 3595 when your environment is "embedded" within U-Boot code, 3596 since then the remainder of the flash sector could be used 3597 for U-Boot code. It should be pointed out that this is 3598 STRONGLY DISCOURAGED from a robustness point of view: 3599 updating the environment in flash makes it always 3600 necessary to erase the WHOLE sector. If something goes 3601 wrong before the contents has been restored from a copy in 3602 RAM, your target system will be dead. 3603 3604 - CONFIG_ENV_ADDR_REDUND 3605 CONFIG_ENV_SIZE_REDUND 3606 3607 These settings describe a second storage area used to hold 3608 a redundant copy of the environment data, so that there is 3609 a valid backup copy in case there is a power failure during 3610 a "saveenv" operation. 3611 3612BE CAREFUL! Any changes to the flash layout, and some changes to the 3613source code will make it necessary to adapt <board>/u-boot.lds* 3614accordingly! 3615 3616 3617- CONFIG_ENV_IS_IN_NVRAM: 3618 3619 Define this if you have some non-volatile memory device 3620 (NVRAM, battery buffered SRAM) which you want to use for the 3621 environment. 3622 3623 - CONFIG_ENV_ADDR: 3624 - CONFIG_ENV_SIZE: 3625 3626 These two #defines are used to determine the memory area you 3627 want to use for environment. It is assumed that this memory 3628 can just be read and written to, without any special 3629 provision. 3630 3631BE CAREFUL! The first access to the environment happens quite early 3632in U-Boot initalization (when we try to get the setting of for the 3633console baudrate). You *MUST* have mapped your NVRAM area then, or 3634U-Boot will hang. 3635 3636Please note that even with NVRAM we still use a copy of the 3637environment in RAM: we could work on NVRAM directly, but we want to 3638keep settings there always unmodified except somebody uses "saveenv" 3639to save the current settings. 3640 3641 3642- CONFIG_ENV_IS_IN_EEPROM: 3643 3644 Use this if you have an EEPROM or similar serial access 3645 device and a driver for it. 3646 3647 - CONFIG_ENV_OFFSET: 3648 - CONFIG_ENV_SIZE: 3649 3650 These two #defines specify the offset and size of the 3651 environment area within the total memory of your EEPROM. 3652 3653 - CONFIG_SYS_I2C_EEPROM_ADDR: 3654 If defined, specified the chip address of the EEPROM device. 3655 The default address is zero. 3656 3657 - CONFIG_SYS_EEPROM_PAGE_WRITE_BITS: 3658 If defined, the number of bits used to address bytes in a 3659 single page in the EEPROM device. A 64 byte page, for example 3660 would require six bits. 3661 3662 - CONFIG_SYS_EEPROM_PAGE_WRITE_DELAY_MS: 3663 If defined, the number of milliseconds to delay between 3664 page writes. The default is zero milliseconds. 3665 3666 - CONFIG_SYS_I2C_EEPROM_ADDR_LEN: 3667 The length in bytes of the EEPROM memory array address. Note 3668 that this is NOT the chip address length! 3669 3670 - CONFIG_SYS_I2C_EEPROM_ADDR_OVERFLOW: 3671 EEPROM chips that implement "address overflow" are ones 3672 like Catalyst 24WC04/08/16 which has 9/10/11 bits of 3673 address and the extra bits end up in the "chip address" bit 3674 slots. This makes a 24WC08 (1Kbyte) chip look like four 256 3675 byte chips. 3676 3677 Note that we consider the length of the address field to 3678 still be one byte because the extra address bits are hidden 3679 in the chip address. 3680 3681 - CONFIG_SYS_EEPROM_SIZE: 3682 The size in bytes of the EEPROM device. 3683 3684 - CONFIG_ENV_EEPROM_IS_ON_I2C 3685 define this, if you have I2C and SPI activated, and your 3686 EEPROM, which holds the environment, is on the I2C bus. 3687 3688 - CONFIG_I2C_ENV_EEPROM_BUS 3689 if you have an Environment on an EEPROM reached over 3690 I2C muxes, you can define here, how to reach this 3691 EEPROM. For example: 3692 3693 #define CONFIG_I2C_ENV_EEPROM_BUS 1 3694 3695 EEPROM which holds the environment, is reached over 3696 a pca9547 i2c mux with address 0x70, channel 3. 3697 3698- CONFIG_ENV_IS_IN_DATAFLASH: 3699 3700 Define this if you have a DataFlash memory device which you 3701 want to use for the environment. 3702 3703 - CONFIG_ENV_OFFSET: 3704 - CONFIG_ENV_ADDR: 3705 - CONFIG_ENV_SIZE: 3706 3707 These three #defines specify the offset and size of the 3708 environment area within the total memory of your DataFlash placed 3709 at the specified address. 3710 3711- CONFIG_ENV_IS_IN_REMOTE: 3712 3713 Define this if you have a remote memory space which you 3714 want to use for the local device's environment. 3715 3716 - CONFIG_ENV_ADDR: 3717 - CONFIG_ENV_SIZE: 3718 3719 These two #defines specify the address and size of the 3720 environment area within the remote memory space. The 3721 local device can get the environment from remote memory 3722 space by SRIO or PCIE links. 3723 3724BE CAREFUL! For some special cases, the local device can not use 3725"saveenv" command. For example, the local device will get the 3726environment stored in a remote NOR flash by SRIO or PCIE link, 3727but it can not erase, write this NOR flash by SRIO or PCIE interface. 3728 3729- CONFIG_ENV_IS_IN_NAND: 3730 3731 Define this if you have a NAND device which you want to use 3732 for the environment. 3733 3734 - CONFIG_ENV_OFFSET: 3735 - CONFIG_ENV_SIZE: 3736 3737 These two #defines specify the offset and size of the environment 3738 area within the first NAND device. CONFIG_ENV_OFFSET must be 3739 aligned to an erase block boundary. 3740 3741 - CONFIG_ENV_OFFSET_REDUND (optional): 3742 3743 This setting describes a second storage area of CONFIG_ENV_SIZE 3744 size used to hold a redundant copy of the environment data, so 3745 that there is a valid backup copy in case there is a power failure 3746 during a "saveenv" operation. CONFIG_ENV_OFFSET_RENDUND must be 3747 aligned to an erase block boundary. 3748 3749 - CONFIG_ENV_RANGE (optional): 3750 3751 Specifies the length of the region in which the environment 3752 can be written. This should be a multiple of the NAND device's 3753 block size. Specifying a range with more erase blocks than 3754 are needed to hold CONFIG_ENV_SIZE allows bad blocks within 3755 the range to be avoided. 3756 3757 - CONFIG_ENV_OFFSET_OOB (optional): 3758 3759 Enables support for dynamically retrieving the offset of the 3760 environment from block zero's out-of-band data. The 3761 "nand env.oob" command can be used to record this offset. 3762 Currently, CONFIG_ENV_OFFSET_REDUND is not supported when 3763 using CONFIG_ENV_OFFSET_OOB. 3764 3765- CONFIG_NAND_ENV_DST 3766 3767 Defines address in RAM to which the nand_spl code should copy the 3768 environment. If redundant environment is used, it will be copied to 3769 CONFIG_NAND_ENV_DST + CONFIG_ENV_SIZE. 3770 3771- CONFIG_ENV_IS_IN_UBI: 3772 3773 Define this if you have an UBI volume that you want to use for the 3774 environment. This has the benefit of wear-leveling the environment 3775 accesses, which is important on NAND. 3776 3777 - CONFIG_ENV_UBI_PART: 3778 3779 Define this to a string that is the mtd partition containing the UBI. 3780 3781 - CONFIG_ENV_UBI_VOLUME: 3782 3783 Define this to the name of the volume that you want to store the 3784 environment in. 3785 3786 - CONFIG_ENV_UBI_VOLUME_REDUND: 3787 3788 Define this to the name of another volume to store a second copy of 3789 the environment in. This will enable redundant environments in UBI. 3790 It is assumed that both volumes are in the same MTD partition. 3791 3792 - CONFIG_UBI_SILENCE_MSG 3793 - CONFIG_UBIFS_SILENCE_MSG 3794 3795 You will probably want to define these to avoid a really noisy system 3796 when storing the env in UBI. 3797 3798- CONFIG_ENV_IS_IN_MMC: 3799 3800 Define this if you have an MMC device which you want to use for the 3801 environment. 3802 3803 - CONFIG_SYS_MMC_ENV_DEV: 3804 3805 Specifies which MMC device the environment is stored in. 3806 3807 - CONFIG_SYS_MMC_ENV_PART (optional): 3808 3809 Specifies which MMC partition the environment is stored in. If not 3810 set, defaults to partition 0, the user area. Common values might be 3811 1 (first MMC boot partition), 2 (second MMC boot partition). 3812 3813 - CONFIG_ENV_OFFSET: 3814 - CONFIG_ENV_SIZE: 3815 3816 These two #defines specify the offset and size of the environment 3817 area within the specified MMC device. 3818 3819 If offset is positive (the usual case), it is treated as relative to 3820 the start of the MMC partition. If offset is negative, it is treated 3821 as relative to the end of the MMC partition. This can be useful if 3822 your board may be fitted with different MMC devices, which have 3823 different sizes for the MMC partitions, and you always want the 3824 environment placed at the very end of the partition, to leave the 3825 maximum possible space before it, to store other data. 3826 3827 These two values are in units of bytes, but must be aligned to an 3828 MMC sector boundary. 3829 3830 - CONFIG_ENV_OFFSET_REDUND (optional): 3831 3832 Specifies a second storage area, of CONFIG_ENV_SIZE size, used to 3833 hold a redundant copy of the environment data. This provides a 3834 valid backup copy in case the other copy is corrupted, e.g. due 3835 to a power failure during a "saveenv" operation. 3836 3837 This value may also be positive or negative; this is handled in the 3838 same way as CONFIG_ENV_OFFSET. 3839 3840 This value is also in units of bytes, but must also be aligned to 3841 an MMC sector boundary. 3842 3843 - CONFIG_ENV_SIZE_REDUND (optional): 3844 3845 This value need not be set, even when CONFIG_ENV_OFFSET_REDUND is 3846 set. If this value is set, it must be set to the same value as 3847 CONFIG_ENV_SIZE. 3848 3849- CONFIG_SYS_SPI_INIT_OFFSET 3850 3851 Defines offset to the initial SPI buffer area in DPRAM. The 3852 area is used at an early stage (ROM part) if the environment 3853 is configured to reside in the SPI EEPROM: We need a 520 byte 3854 scratch DPRAM area. It is used between the two initialization 3855 calls (spi_init_f() and spi_init_r()). A value of 0xB00 seems 3856 to be a good choice since it makes it far enough from the 3857 start of the data area as well as from the stack pointer. 3858 3859Please note that the environment is read-only until the monitor 3860has been relocated to RAM and a RAM copy of the environment has been 3861created; also, when using EEPROM you will have to use getenv_f() 3862until then to read environment variables. 3863 3864The environment is protected by a CRC32 checksum. Before the monitor 3865is relocated into RAM, as a result of a bad CRC you will be working 3866with the compiled-in default environment - *silently*!!! [This is 3867necessary, because the first environment variable we need is the 3868"baudrate" setting for the console - if we have a bad CRC, we don't 3869have any device yet where we could complain.] 3870 3871Note: once the monitor has been relocated, then it will complain if 3872the default environment is used; a new CRC is computed as soon as you 3873use the "saveenv" command to store a valid environment. 3874 3875- CONFIG_SYS_FAULT_ECHO_LINK_DOWN: 3876 Echo the inverted Ethernet link state to the fault LED. 3877 3878 Note: If this option is active, then CONFIG_SYS_FAULT_MII_ADDR 3879 also needs to be defined. 3880 3881- CONFIG_SYS_FAULT_MII_ADDR: 3882 MII address of the PHY to check for the Ethernet link state. 3883 3884- CONFIG_NS16550_MIN_FUNCTIONS: 3885 Define this if you desire to only have use of the NS16550_init 3886 and NS16550_putc functions for the serial driver located at 3887 drivers/serial/ns16550.c. This option is useful for saving 3888 space for already greatly restricted images, including but not 3889 limited to NAND_SPL configurations. 3890 3891- CONFIG_DISPLAY_BOARDINFO 3892 Display information about the board that U-Boot is running on 3893 when U-Boot starts up. The board function checkboard() is called 3894 to do this. 3895 3896- CONFIG_DISPLAY_BOARDINFO_LATE 3897 Similar to the previous option, but display this information 3898 later, once stdio is running and output goes to the LCD, if 3899 present. 3900 3901Low Level (hardware related) configuration options: 3902--------------------------------------------------- 3903 3904- CONFIG_SYS_CACHELINE_SIZE: 3905 Cache Line Size of the CPU. 3906 3907- CONFIG_SYS_DEFAULT_IMMR: 3908 Default address of the IMMR after system reset. 3909 3910 Needed on some 8260 systems (MPC8260ADS, PQ2FADS-ZU, 3911 and RPXsuper) to be able to adjust the position of 3912 the IMMR register after a reset. 3913 3914- CONFIG_SYS_CCSRBAR_DEFAULT: 3915 Default (power-on reset) physical address of CCSR on Freescale 3916 PowerPC SOCs. 3917 3918- CONFIG_SYS_CCSRBAR: 3919 Virtual address of CCSR. On a 32-bit build, this is typically 3920 the same value as CONFIG_SYS_CCSRBAR_DEFAULT. 3921 3922 CONFIG_SYS_DEFAULT_IMMR must also be set to this value, 3923 for cross-platform code that uses that macro instead. 3924 3925- CONFIG_SYS_CCSRBAR_PHYS: 3926 Physical address of CCSR. CCSR can be relocated to a new 3927 physical address, if desired. In this case, this macro should 3928 be set to that address. Otherwise, it should be set to the 3929 same value as CONFIG_SYS_CCSRBAR_DEFAULT. For example, CCSR 3930 is typically relocated on 36-bit builds. It is recommended 3931 that this macro be defined via the _HIGH and _LOW macros: 3932 3933 #define CONFIG_SYS_CCSRBAR_PHYS ((CONFIG_SYS_CCSRBAR_PHYS_HIGH 3934 * 1ull) << 32 | CONFIG_SYS_CCSRBAR_PHYS_LOW) 3935 3936- CONFIG_SYS_CCSRBAR_PHYS_HIGH: 3937 Bits 33-36 of CONFIG_SYS_CCSRBAR_PHYS. This value is typically 3938 either 0 (32-bit build) or 0xF (36-bit build). This macro is 3939 used in assembly code, so it must not contain typecasts or 3940 integer size suffixes (e.g. "ULL"). 3941 3942- CONFIG_SYS_CCSRBAR_PHYS_LOW: 3943 Lower 32-bits of CONFIG_SYS_CCSRBAR_PHYS. This macro is 3944 used in assembly code, so it must not contain typecasts or 3945 integer size suffixes (e.g. "ULL"). 3946 3947- CONFIG_SYS_CCSR_DO_NOT_RELOCATE: 3948 If this macro is defined, then CONFIG_SYS_CCSRBAR_PHYS will be 3949 forced to a value that ensures that CCSR is not relocated. 3950 3951- Floppy Disk Support: 3952 CONFIG_SYS_FDC_DRIVE_NUMBER 3953 3954 the default drive number (default value 0) 3955 3956 CONFIG_SYS_ISA_IO_STRIDE 3957 3958 defines the spacing between FDC chipset registers 3959 (default value 1) 3960 3961 CONFIG_SYS_ISA_IO_OFFSET 3962 3963 defines the offset of register from address. It 3964 depends on which part of the data bus is connected to 3965 the FDC chipset. (default value 0) 3966 3967 If CONFIG_SYS_ISA_IO_STRIDE CONFIG_SYS_ISA_IO_OFFSET and 3968 CONFIG_SYS_FDC_DRIVE_NUMBER are undefined, they take their 3969 default value. 3970 3971 if CONFIG_SYS_FDC_HW_INIT is defined, then the function 3972 fdc_hw_init() is called at the beginning of the FDC 3973 setup. fdc_hw_init() must be provided by the board 3974 source code. It is used to make hardware dependant 3975 initializations. 3976 3977- CONFIG_IDE_AHB: 3978 Most IDE controllers were designed to be connected with PCI 3979 interface. Only few of them were designed for AHB interface. 3980 When software is doing ATA command and data transfer to 3981 IDE devices through IDE-AHB controller, some additional 3982 registers accessing to these kind of IDE-AHB controller 3983 is requierd. 3984 3985- CONFIG_SYS_IMMR: Physical address of the Internal Memory. 3986 DO NOT CHANGE unless you know exactly what you're 3987 doing! (11-4) [MPC8xx/82xx systems only] 3988 3989- CONFIG_SYS_INIT_RAM_ADDR: 3990 3991 Start address of memory area that can be used for 3992 initial data and stack; please note that this must be 3993 writable memory that is working WITHOUT special 3994 initialization, i. e. you CANNOT use normal RAM which 3995 will become available only after programming the 3996 memory controller and running certain initialization 3997 sequences. 3998 3999 U-Boot uses the following memory types: 4000 - MPC8xx and MPC8260: IMMR (internal memory of the CPU) 4001 - MPC824X: data cache 4002 - PPC4xx: data cache 4003 4004- CONFIG_SYS_GBL_DATA_OFFSET: 4005 4006 Offset of the initial data structure in the memory 4007 area defined by CONFIG_SYS_INIT_RAM_ADDR. Usually 4008 CONFIG_SYS_GBL_DATA_OFFSET is chosen such that the initial 4009 data is located at the end of the available space 4010 (sometimes written as (CONFIG_SYS_INIT_RAM_SIZE - 4011 CONFIG_SYS_INIT_DATA_SIZE), and the initial stack is just 4012 below that area (growing from (CONFIG_SYS_INIT_RAM_ADDR + 4013 CONFIG_SYS_GBL_DATA_OFFSET) downward. 4014 4015 Note: 4016 On the MPC824X (or other systems that use the data 4017 cache for initial memory) the address chosen for 4018 CONFIG_SYS_INIT_RAM_ADDR is basically arbitrary - it must 4019 point to an otherwise UNUSED address space between 4020 the top of RAM and the start of the PCI space. 4021 4022- CONFIG_SYS_SIUMCR: SIU Module Configuration (11-6) 4023 4024- CONFIG_SYS_SYPCR: System Protection Control (11-9) 4025 4026- CONFIG_SYS_TBSCR: Time Base Status and Control (11-26) 4027 4028- CONFIG_SYS_PISCR: Periodic Interrupt Status and Control (11-31) 4029 4030- CONFIG_SYS_PLPRCR: PLL, Low-Power, and Reset Control Register (15-30) 4031 4032- CONFIG_SYS_SCCR: System Clock and reset Control Register (15-27) 4033 4034- CONFIG_SYS_OR_TIMING_SDRAM: 4035 SDRAM timing 4036 4037- CONFIG_SYS_MAMR_PTA: 4038 periodic timer for refresh 4039 4040- CONFIG_SYS_DER: Debug Event Register (37-47) 4041 4042- FLASH_BASE0_PRELIM, FLASH_BASE1_PRELIM, CONFIG_SYS_REMAP_OR_AM, 4043 CONFIG_SYS_PRELIM_OR_AM, CONFIG_SYS_OR_TIMING_FLASH, CONFIG_SYS_OR0_REMAP, 4044 CONFIG_SYS_OR0_PRELIM, CONFIG_SYS_BR0_PRELIM, CONFIG_SYS_OR1_REMAP, CONFIG_SYS_OR1_PRELIM, 4045 CONFIG_SYS_BR1_PRELIM: 4046 Memory Controller Definitions: BR0/1 and OR0/1 (FLASH) 4047 4048- SDRAM_BASE2_PRELIM, SDRAM_BASE3_PRELIM, SDRAM_MAX_SIZE, 4049 CONFIG_SYS_OR_TIMING_SDRAM, CONFIG_SYS_OR2_PRELIM, CONFIG_SYS_BR2_PRELIM, 4050 CONFIG_SYS_OR3_PRELIM, CONFIG_SYS_BR3_PRELIM: 4051 Memory Controller Definitions: BR2/3 and OR2/3 (SDRAM) 4052 4053- CONFIG_SYS_MAMR_PTA, CONFIG_SYS_MPTPR_2BK_4K, CONFIG_SYS_MPTPR_1BK_4K, CONFIG_SYS_MPTPR_2BK_8K, 4054 CONFIG_SYS_MPTPR_1BK_8K, CONFIG_SYS_MAMR_8COL, CONFIG_SYS_MAMR_9COL: 4055 Machine Mode Register and Memory Periodic Timer 4056 Prescaler definitions (SDRAM timing) 4057 4058- CONFIG_SYS_I2C_UCODE_PATCH, CONFIG_SYS_I2C_DPMEM_OFFSET [0x1FC0]: 4059 enable I2C microcode relocation patch (MPC8xx); 4060 define relocation offset in DPRAM [DSP2] 4061 4062- CONFIG_SYS_SMC_UCODE_PATCH, CONFIG_SYS_SMC_DPMEM_OFFSET [0x1FC0]: 4063 enable SMC microcode relocation patch (MPC8xx); 4064 define relocation offset in DPRAM [SMC1] 4065 4066- CONFIG_SYS_SPI_UCODE_PATCH, CONFIG_SYS_SPI_DPMEM_OFFSET [0x1FC0]: 4067 enable SPI microcode relocation patch (MPC8xx); 4068 define relocation offset in DPRAM [SCC4] 4069 4070- CONFIG_SYS_USE_OSCCLK: 4071 Use OSCM clock mode on MBX8xx board. Be careful, 4072 wrong setting might damage your board. Read 4073 doc/README.MBX before setting this variable! 4074 4075- CONFIG_SYS_CPM_POST_WORD_ADDR: (MPC8xx, MPC8260 only) 4076 Offset of the bootmode word in DPRAM used by post 4077 (Power On Self Tests). This definition overrides 4078 #define'd default value in commproc.h resp. 4079 cpm_8260.h. 4080 4081- CONFIG_SYS_PCI_SLV_MEM_LOCAL, CONFIG_SYS_PCI_SLV_MEM_BUS, CONFIG_SYS_PICMR0_MASK_ATTRIB, 4082 CONFIG_SYS_PCI_MSTR0_LOCAL, CONFIG_SYS_PCIMSK0_MASK, CONFIG_SYS_PCI_MSTR1_LOCAL, 4083 CONFIG_SYS_PCIMSK1_MASK, CONFIG_SYS_PCI_MSTR_MEM_LOCAL, CONFIG_SYS_PCI_MSTR_MEM_BUS, 4084 CONFIG_SYS_CPU_PCI_MEM_START, CONFIG_SYS_PCI_MSTR_MEM_SIZE, CONFIG_SYS_POCMR0_MASK_ATTRIB, 4085 CONFIG_SYS_PCI_MSTR_MEMIO_LOCAL, CONFIG_SYS_PCI_MSTR_MEMIO_BUS, CPU_PCI_MEMIO_START, 4086 CONFIG_SYS_PCI_MSTR_MEMIO_SIZE, CONFIG_SYS_POCMR1_MASK_ATTRIB, CONFIG_SYS_PCI_MSTR_IO_LOCAL, 4087 CONFIG_SYS_PCI_MSTR_IO_BUS, CONFIG_SYS_CPU_PCI_IO_START, CONFIG_SYS_PCI_MSTR_IO_SIZE, 4088 CONFIG_SYS_POCMR2_MASK_ATTRIB: (MPC826x only) 4089 Overrides the default PCI memory map in arch/powerpc/cpu/mpc8260/pci.c if set. 4090 4091- CONFIG_PCI_DISABLE_PCIE: 4092 Disable PCI-Express on systems where it is supported but not 4093 required. 4094 4095- CONFIG_PCI_ENUM_ONLY 4096 Only scan through and get the devices on the busses. 4097 Don't do any setup work, presumably because someone or 4098 something has already done it, and we don't need to do it 4099 a second time. Useful for platforms that are pre-booted 4100 by coreboot or similar. 4101 4102- CONFIG_PCI_INDIRECT_BRIDGE: 4103 Enable support for indirect PCI bridges. 4104 4105- CONFIG_SYS_SRIO: 4106 Chip has SRIO or not 4107 4108- CONFIG_SRIO1: 4109 Board has SRIO 1 port available 4110 4111- CONFIG_SRIO2: 4112 Board has SRIO 2 port available 4113 4114- CONFIG_SRIO_PCIE_BOOT_MASTER 4115 Board can support master function for Boot from SRIO and PCIE 4116 4117- CONFIG_SYS_SRIOn_MEM_VIRT: 4118 Virtual Address of SRIO port 'n' memory region 4119 4120- CONFIG_SYS_SRIOn_MEM_PHYS: 4121 Physical Address of SRIO port 'n' memory region 4122 4123- CONFIG_SYS_SRIOn_MEM_SIZE: 4124 Size of SRIO port 'n' memory region 4125 4126- CONFIG_SYS_NAND_BUSWIDTH_16BIT 4127 Defined to tell the NAND controller that the NAND chip is using 4128 a 16 bit bus. 4129 Not all NAND drivers use this symbol. 4130 Example of drivers that use it: 4131 - drivers/mtd/nand/ndfc.c 4132 - drivers/mtd/nand/mxc_nand.c 4133 4134- CONFIG_SYS_NDFC_EBC0_CFG 4135 Sets the EBC0_CFG register for the NDFC. If not defined 4136 a default value will be used. 4137 4138- CONFIG_SPD_EEPROM 4139 Get DDR timing information from an I2C EEPROM. Common 4140 with pluggable memory modules such as SODIMMs 4141 4142 SPD_EEPROM_ADDRESS 4143 I2C address of the SPD EEPROM 4144 4145- CONFIG_SYS_SPD_BUS_NUM 4146 If SPD EEPROM is on an I2C bus other than the first 4147 one, specify here. Note that the value must resolve 4148 to something your driver can deal with. 4149 4150- CONFIG_SYS_DDR_RAW_TIMING 4151 Get DDR timing information from other than SPD. Common with 4152 soldered DDR chips onboard without SPD. DDR raw timing 4153 parameters are extracted from datasheet and hard-coded into 4154 header files or board specific files. 4155 4156- CONFIG_FSL_DDR_INTERACTIVE 4157 Enable interactive DDR debugging. See doc/README.fsl-ddr. 4158 4159- CONFIG_SYS_83XX_DDR_USES_CS0 4160 Only for 83xx systems. If specified, then DDR should 4161 be configured using CS0 and CS1 instead of CS2 and CS3. 4162 4163- CONFIG_ETHER_ON_FEC[12] 4164 Define to enable FEC[12] on a 8xx series processor. 4165 4166- CONFIG_FEC[12]_PHY 4167 Define to the hardcoded PHY address which corresponds 4168 to the given FEC; i. e. 4169 #define CONFIG_FEC1_PHY 4 4170 means that the PHY with address 4 is connected to FEC1 4171 4172 When set to -1, means to probe for first available. 4173 4174- CONFIG_FEC[12]_PHY_NORXERR 4175 The PHY does not have a RXERR line (RMII only). 4176 (so program the FEC to ignore it). 4177 4178- CONFIG_RMII 4179 Enable RMII mode for all FECs. 4180 Note that this is a global option, we can't 4181 have one FEC in standard MII mode and another in RMII mode. 4182 4183- CONFIG_CRC32_VERIFY 4184 Add a verify option to the crc32 command. 4185 The syntax is: 4186 4187 => crc32 -v <address> <count> <crc32> 4188 4189 Where address/count indicate a memory area 4190 and crc32 is the correct crc32 which the 4191 area should have. 4192 4193- CONFIG_LOOPW 4194 Add the "loopw" memory command. This only takes effect if 4195 the memory commands are activated globally (CONFIG_CMD_MEM). 4196 4197- CONFIG_MX_CYCLIC 4198 Add the "mdc" and "mwc" memory commands. These are cyclic 4199 "md/mw" commands. 4200 Examples: 4201 4202 => mdc.b 10 4 500 4203 This command will print 4 bytes (10,11,12,13) each 500 ms. 4204 4205 => mwc.l 100 12345678 10 4206 This command will write 12345678 to address 100 all 10 ms. 4207 4208 This only takes effect if the memory commands are activated 4209 globally (CONFIG_CMD_MEM). 4210 4211- CONFIG_SKIP_LOWLEVEL_INIT 4212 [ARM, NDS32, MIPS only] If this variable is defined, then certain 4213 low level initializations (like setting up the memory 4214 controller) are omitted and/or U-Boot does not 4215 relocate itself into RAM. 4216 4217 Normally this variable MUST NOT be defined. The only 4218 exception is when U-Boot is loaded (to RAM) by some 4219 other boot loader or by a debugger which performs 4220 these initializations itself. 4221 4222- CONFIG_SPL_BUILD 4223 Modifies the behaviour of start.S when compiling a loader 4224 that is executed before the actual U-Boot. E.g. when 4225 compiling a NAND SPL. 4226 4227- CONFIG_TPL_BUILD 4228 Modifies the behaviour of start.S when compiling a loader 4229 that is executed after the SPL and before the actual U-Boot. 4230 It is loaded by the SPL. 4231 4232- CONFIG_SYS_MPC85XX_NO_RESETVEC 4233 Only for 85xx systems. If this variable is specified, the section 4234 .resetvec is not kept and the section .bootpg is placed in the 4235 previous 4k of the .text section. 4236 4237- CONFIG_ARCH_MAP_SYSMEM 4238 Generally U-Boot (and in particular the md command) uses 4239 effective address. It is therefore not necessary to regard 4240 U-Boot address as virtual addresses that need to be translated 4241 to physical addresses. However, sandbox requires this, since 4242 it maintains its own little RAM buffer which contains all 4243 addressable memory. This option causes some memory accesses 4244 to be mapped through map_sysmem() / unmap_sysmem(). 4245 4246- CONFIG_USE_ARCH_MEMCPY 4247 CONFIG_USE_ARCH_MEMSET 4248 If these options are used a optimized version of memcpy/memset will 4249 be used if available. These functions may be faster under some 4250 conditions but may increase the binary size. 4251 4252- CONFIG_X86_RESET_VECTOR 4253 If defined, the x86 reset vector code is included. This is not 4254 needed when U-Boot is running from Coreboot. 4255 4256- CONFIG_SYS_MPUCLK 4257 Defines the MPU clock speed (in MHz). 4258 4259 NOTE : currently only supported on AM335x platforms. 4260 4261Freescale QE/FMAN Firmware Support: 4262----------------------------------- 4263 4264The Freescale QUICCEngine (QE) and Frame Manager (FMAN) both support the 4265loading of "firmware", which is encoded in the QE firmware binary format. 4266This firmware often needs to be loaded during U-Boot booting, so macros 4267are used to identify the storage device (NOR flash, SPI, etc) and the address 4268within that device. 4269 4270- CONFIG_SYS_QE_FMAN_FW_ADDR 4271 The address in the storage device where the firmware is located. The 4272 meaning of this address depends on which CONFIG_SYS_QE_FW_IN_xxx macro 4273 is also specified. 4274 4275- CONFIG_SYS_QE_FMAN_FW_LENGTH 4276 The maximum possible size of the firmware. The firmware binary format 4277 has a field that specifies the actual size of the firmware, but it 4278 might not be possible to read any part of the firmware unless some 4279 local storage is allocated to hold the entire firmware first. 4280 4281- CONFIG_SYS_QE_FMAN_FW_IN_NOR 4282 Specifies that QE/FMAN firmware is located in NOR flash, mapped as 4283 normal addressable memory via the LBC. CONFIG_SYS_FMAN_FW_ADDR is the 4284 virtual address in NOR flash. 4285 4286- CONFIG_SYS_QE_FMAN_FW_IN_NAND 4287 Specifies that QE/FMAN firmware is located in NAND flash. 4288 CONFIG_SYS_FMAN_FW_ADDR is the offset within NAND flash. 4289 4290- CONFIG_SYS_QE_FMAN_FW_IN_MMC 4291 Specifies that QE/FMAN firmware is located on the primary SD/MMC 4292 device. CONFIG_SYS_FMAN_FW_ADDR is the byte offset on that device. 4293 4294- CONFIG_SYS_QE_FMAN_FW_IN_SPIFLASH 4295 Specifies that QE/FMAN firmware is located on the primary SPI 4296 device. CONFIG_SYS_FMAN_FW_ADDR is the byte offset on that device. 4297 4298- CONFIG_SYS_QE_FMAN_FW_IN_REMOTE 4299 Specifies that QE/FMAN firmware is located in the remote (master) 4300 memory space. CONFIG_SYS_FMAN_FW_ADDR is a virtual address which 4301 can be mapped from slave TLB->slave LAW->slave SRIO or PCIE outbound 4302 window->master inbound window->master LAW->the ucode address in 4303 master's memory space. 4304 4305Building the Software: 4306====================== 4307 4308Building U-Boot has been tested in several native build environments 4309and in many different cross environments. Of course we cannot support 4310all possibly existing versions of cross development tools in all 4311(potentially obsolete) versions. In case of tool chain problems we 4312recommend to use the ELDK (see http://www.denx.de/wiki/DULG/ELDK) 4313which is extensively used to build and test U-Boot. 4314 4315If you are not using a native environment, it is assumed that you 4316have GNU cross compiling tools available in your path. In this case, 4317you must set the environment variable CROSS_COMPILE in your shell. 4318Note that no changes to the Makefile or any other source files are 4319necessary. For example using the ELDK on a 4xx CPU, please enter: 4320 4321 $ CROSS_COMPILE=ppc_4xx- 4322 $ export CROSS_COMPILE 4323 4324Note: If you wish to generate Windows versions of the utilities in 4325 the tools directory you can use the MinGW toolchain 4326 (http://www.mingw.org). Set your HOST tools to the MinGW 4327 toolchain and execute 'make tools'. For example: 4328 4329 $ make HOSTCC=i586-mingw32msvc-gcc HOSTSTRIP=i586-mingw32msvc-strip tools 4330 4331 Binaries such as tools/mkimage.exe will be created which can 4332 be executed on computers running Windows. 4333 4334U-Boot is intended to be simple to build. After installing the 4335sources you must configure U-Boot for one specific board type. This 4336is done by typing: 4337 4338 make NAME_config 4339 4340where "NAME_config" is the name of one of the existing configu- 4341rations; see boards.cfg for supported names. 4342 4343Note: for some board special configuration names may exist; check if 4344 additional information is available from the board vendor; for 4345 instance, the TQM823L systems are available without (standard) 4346 or with LCD support. You can select such additional "features" 4347 when choosing the configuration, i. e. 4348 4349 make TQM823L_config 4350 - will configure for a plain TQM823L, i. e. no LCD support 4351 4352 make TQM823L_LCD_config 4353 - will configure for a TQM823L with U-Boot console on LCD 4354 4355 etc. 4356 4357 4358Finally, type "make all", and you should get some working U-Boot 4359images ready for download to / installation on your system: 4360 4361- "u-boot.bin" is a raw binary image 4362- "u-boot" is an image in ELF binary format 4363- "u-boot.srec" is in Motorola S-Record format 4364 4365By default the build is performed locally and the objects are saved 4366in the source directory. One of the two methods can be used to change 4367this behavior and build U-Boot to some external directory: 4368 43691. Add O= to the make command line invocations: 4370 4371 make O=/tmp/build distclean 4372 make O=/tmp/build NAME_config 4373 make O=/tmp/build all 4374 43752. Set environment variable BUILD_DIR to point to the desired location: 4376 4377 export BUILD_DIR=/tmp/build 4378 make distclean 4379 make NAME_config 4380 make all 4381 4382Note that the command line "O=" setting overrides the BUILD_DIR environment 4383variable. 4384 4385 4386Please be aware that the Makefiles assume you are using GNU make, so 4387for instance on NetBSD you might need to use "gmake" instead of 4388native "make". 4389 4390 4391If the system board that you have is not listed, then you will need 4392to port U-Boot to your hardware platform. To do this, follow these 4393steps: 4394 43951. Add a new configuration option for your board to the toplevel 4396 "boards.cfg" file, using the existing entries as examples. 4397 Follow the instructions there to keep the boards in order. 43982. Create a new directory to hold your board specific code. Add any 4399 files you need. In your board directory, you will need at least 4400 the "Makefile", a "<board>.c", "flash.c" and "u-boot.lds". 44013. Create a new configuration file "include/configs/<board>.h" for 4402 your board 44033. If you're porting U-Boot to a new CPU, then also create a new 4404 directory to hold your CPU specific code. Add any files you need. 44054. Run "make <board>_config" with your new name. 44065. Type "make", and you should get a working "u-boot.srec" file 4407 to be installed on your target system. 44086. Debug and solve any problems that might arise. 4409 [Of course, this last step is much harder than it sounds.] 4410 4411 4412Testing of U-Boot Modifications, Ports to New Hardware, etc.: 4413============================================================== 4414 4415If you have modified U-Boot sources (for instance added a new board 4416or support for new devices, a new CPU, etc.) you are expected to 4417provide feedback to the other developers. The feedback normally takes 4418the form of a "patch", i. e. a context diff against a certain (latest 4419official or latest in the git repository) version of U-Boot sources. 4420 4421But before you submit such a patch, please verify that your modifi- 4422cation did not break existing code. At least make sure that *ALL* of 4423the supported boards compile WITHOUT ANY compiler warnings. To do so, 4424just run the "MAKEALL" script, which will configure and build U-Boot 4425for ALL supported system. Be warned, this will take a while. You can 4426select which (cross) compiler to use by passing a `CROSS_COMPILE' 4427environment variable to the script, i. e. to use the ELDK cross tools 4428you can type 4429 4430 CROSS_COMPILE=ppc_8xx- MAKEALL 4431 4432or to build on a native PowerPC system you can type 4433 4434 CROSS_COMPILE=' ' MAKEALL 4435 4436When using the MAKEALL script, the default behaviour is to build 4437U-Boot in the source directory. This location can be changed by 4438setting the BUILD_DIR environment variable. Also, for each target 4439built, the MAKEALL script saves two log files (<target>.ERR and 4440<target>.MAKEALL) in the <source dir>/LOG directory. This default 4441location can be changed by setting the MAKEALL_LOGDIR environment 4442variable. For example: 4443 4444 export BUILD_DIR=/tmp/build 4445 export MAKEALL_LOGDIR=/tmp/log 4446 CROSS_COMPILE=ppc_8xx- MAKEALL 4447 4448With the above settings build objects are saved in the /tmp/build, 4449log files are saved in the /tmp/log and the source tree remains clean 4450during the whole build process. 4451 4452 4453See also "U-Boot Porting Guide" below. 4454 4455 4456Monitor Commands - Overview: 4457============================ 4458 4459go - start application at address 'addr' 4460run - run commands in an environment variable 4461bootm - boot application image from memory 4462bootp - boot image via network using BootP/TFTP protocol 4463bootz - boot zImage from memory 4464tftpboot- boot image via network using TFTP protocol 4465 and env variables "ipaddr" and "serverip" 4466 (and eventually "gatewayip") 4467tftpput - upload a file via network using TFTP protocol 4468rarpboot- boot image via network using RARP/TFTP protocol 4469diskboot- boot from IDE devicebootd - boot default, i.e., run 'bootcmd' 4470loads - load S-Record file over serial line 4471loadb - load binary file over serial line (kermit mode) 4472md - memory display 4473mm - memory modify (auto-incrementing) 4474nm - memory modify (constant address) 4475mw - memory write (fill) 4476cp - memory copy 4477cmp - memory compare 4478crc32 - checksum calculation 4479i2c - I2C sub-system 4480sspi - SPI utility commands 4481base - print or set address offset 4482printenv- print environment variables 4483setenv - set environment variables 4484saveenv - save environment variables to persistent storage 4485protect - enable or disable FLASH write protection 4486erase - erase FLASH memory 4487flinfo - print FLASH memory information 4488nand - NAND memory operations (see doc/README.nand) 4489bdinfo - print Board Info structure 4490iminfo - print header information for application image 4491coninfo - print console devices and informations 4492ide - IDE sub-system 4493loop - infinite loop on address range 4494loopw - infinite write loop on address range 4495mtest - simple RAM test 4496icache - enable or disable instruction cache 4497dcache - enable or disable data cache 4498reset - Perform RESET of the CPU 4499echo - echo args to console 4500version - print monitor version 4501help - print online help 4502? - alias for 'help' 4503 4504 4505Monitor Commands - Detailed Description: 4506======================================== 4507 4508TODO. 4509 4510For now: just type "help <command>". 4511 4512 4513Environment Variables: 4514====================== 4515 4516U-Boot supports user configuration using Environment Variables which 4517can be made persistent by saving to Flash memory. 4518 4519Environment Variables are set using "setenv", printed using 4520"printenv", and saved to Flash using "saveenv". Using "setenv" 4521without a value can be used to delete a variable from the 4522environment. As long as you don't save the environment you are 4523working with an in-memory copy. In case the Flash area containing the 4524environment is erased by accident, a default environment is provided. 4525 4526Some configuration options can be set using Environment Variables. 4527 4528List of environment variables (most likely not complete): 4529 4530 baudrate - see CONFIG_BAUDRATE 4531 4532 bootdelay - see CONFIG_BOOTDELAY 4533 4534 bootcmd - see CONFIG_BOOTCOMMAND 4535 4536 bootargs - Boot arguments when booting an RTOS image 4537 4538 bootfile - Name of the image to load with TFTP 4539 4540 bootm_low - Memory range available for image processing in the bootm 4541 command can be restricted. This variable is given as 4542 a hexadecimal number and defines lowest address allowed 4543 for use by the bootm command. See also "bootm_size" 4544 environment variable. Address defined by "bootm_low" is 4545 also the base of the initial memory mapping for the Linux 4546 kernel -- see the description of CONFIG_SYS_BOOTMAPSZ and 4547 bootm_mapsize. 4548 4549 bootm_mapsize - Size of the initial memory mapping for the Linux kernel. 4550 This variable is given as a hexadecimal number and it 4551 defines the size of the memory region starting at base 4552 address bootm_low that is accessible by the Linux kernel 4553 during early boot. If unset, CONFIG_SYS_BOOTMAPSZ is used 4554 as the default value if it is defined, and bootm_size is 4555 used otherwise. 4556 4557 bootm_size - Memory range available for image processing in the bootm 4558 command can be restricted. This variable is given as 4559 a hexadecimal number and defines the size of the region 4560 allowed for use by the bootm command. See also "bootm_low" 4561 environment variable. 4562 4563 updatefile - Location of the software update file on a TFTP server, used 4564 by the automatic software update feature. Please refer to 4565 documentation in doc/README.update for more details. 4566 4567 autoload - if set to "no" (any string beginning with 'n'), 4568 "bootp" will just load perform a lookup of the 4569 configuration from the BOOTP server, but not try to 4570 load any image using TFTP 4571 4572 autostart - if set to "yes", an image loaded using the "bootp", 4573 "rarpboot", "tftpboot" or "diskboot" commands will 4574 be automatically started (by internally calling 4575 "bootm") 4576 4577 If set to "no", a standalone image passed to the 4578 "bootm" command will be copied to the load address 4579 (and eventually uncompressed), but NOT be started. 4580 This can be used to load and uncompress arbitrary 4581 data. 4582 4583 fdt_high - if set this restricts the maximum address that the 4584 flattened device tree will be copied into upon boot. 4585 For example, if you have a system with 1 GB memory 4586 at physical address 0x10000000, while Linux kernel 4587 only recognizes the first 704 MB as low memory, you 4588 may need to set fdt_high as 0x3C000000 to have the 4589 device tree blob be copied to the maximum address 4590 of the 704 MB low memory, so that Linux kernel can 4591 access it during the boot procedure. 4592 4593 If this is set to the special value 0xFFFFFFFF then 4594 the fdt will not be copied at all on boot. For this 4595 to work it must reside in writable memory, have 4596 sufficient padding on the end of it for u-boot to 4597 add the information it needs into it, and the memory 4598 must be accessible by the kernel. 4599 4600 fdtcontroladdr- if set this is the address of the control flattened 4601 device tree used by U-Boot when CONFIG_OF_CONTROL is 4602 defined. 4603 4604 i2cfast - (PPC405GP|PPC405EP only) 4605 if set to 'y' configures Linux I2C driver for fast 4606 mode (400kHZ). This environment variable is used in 4607 initialization code. So, for changes to be effective 4608 it must be saved and board must be reset. 4609 4610 initrd_high - restrict positioning of initrd images: 4611 If this variable is not set, initrd images will be 4612 copied to the highest possible address in RAM; this 4613 is usually what you want since it allows for 4614 maximum initrd size. If for some reason you want to 4615 make sure that the initrd image is loaded below the 4616 CONFIG_SYS_BOOTMAPSZ limit, you can set this environment 4617 variable to a value of "no" or "off" or "0". 4618 Alternatively, you can set it to a maximum upper 4619 address to use (U-Boot will still check that it 4620 does not overwrite the U-Boot stack and data). 4621 4622 For instance, when you have a system with 16 MB 4623 RAM, and want to reserve 4 MB from use by Linux, 4624 you can do this by adding "mem=12M" to the value of 4625 the "bootargs" variable. However, now you must make 4626 sure that the initrd image is placed in the first 4627 12 MB as well - this can be done with 4628 4629 setenv initrd_high 00c00000 4630 4631 If you set initrd_high to 0xFFFFFFFF, this is an 4632 indication to U-Boot that all addresses are legal 4633 for the Linux kernel, including addresses in flash 4634 memory. In this case U-Boot will NOT COPY the 4635 ramdisk at all. This may be useful to reduce the 4636 boot time on your system, but requires that this 4637 feature is supported by your Linux kernel. 4638 4639 ipaddr - IP address; needed for tftpboot command 4640 4641 loadaddr - Default load address for commands like "bootp", 4642 "rarpboot", "tftpboot", "loadb" or "diskboot" 4643 4644 loads_echo - see CONFIG_LOADS_ECHO 4645 4646 serverip - TFTP server IP address; needed for tftpboot command 4647 4648 bootretry - see CONFIG_BOOT_RETRY_TIME 4649 4650 bootdelaykey - see CONFIG_AUTOBOOT_DELAY_STR 4651 4652 bootstopkey - see CONFIG_AUTOBOOT_STOP_STR 4653 4654 ethprime - controls which interface is used first. 4655 4656 ethact - controls which interface is currently active. 4657 For example you can do the following 4658 4659 => setenv ethact FEC 4660 => ping 192.168.0.1 # traffic sent on FEC 4661 => setenv ethact SCC 4662 => ping 10.0.0.1 # traffic sent on SCC 4663 4664 ethrotate - When set to "no" U-Boot does not go through all 4665 available network interfaces. 4666 It just stays at the currently selected interface. 4667 4668 netretry - When set to "no" each network operation will 4669 either succeed or fail without retrying. 4670 When set to "once" the network operation will 4671 fail when all the available network interfaces 4672 are tried once without success. 4673 Useful on scripts which control the retry operation 4674 themselves. 4675 4676 npe_ucode - set load address for the NPE microcode 4677 4678 silent_linux - If set then linux will be told to boot silently, by 4679 changing the console to be empty. If "yes" it will be 4680 made silent. If "no" it will not be made silent. If 4681 unset, then it will be made silent if the U-Boot console 4682 is silent. 4683 4684 tftpsrcport - If this is set, the value is used for TFTP's 4685 UDP source port. 4686 4687 tftpdstport - If this is set, the value is used for TFTP's UDP 4688 destination port instead of the Well Know Port 69. 4689 4690 tftpblocksize - Block size to use for TFTP transfers; if not set, 4691 we use the TFTP server's default block size 4692 4693 tftptimeout - Retransmission timeout for TFTP packets (in milli- 4694 seconds, minimum value is 1000 = 1 second). Defines 4695 when a packet is considered to be lost so it has to 4696 be retransmitted. The default is 5000 = 5 seconds. 4697 Lowering this value may make downloads succeed 4698 faster in networks with high packet loss rates or 4699 with unreliable TFTP servers. 4700 4701 vlan - When set to a value < 4095 the traffic over 4702 Ethernet is encapsulated/received over 802.1q 4703 VLAN tagged frames. 4704 4705The following image location variables contain the location of images 4706used in booting. The "Image" column gives the role of the image and is 4707not an environment variable name. The other columns are environment 4708variable names. "File Name" gives the name of the file on a TFTP 4709server, "RAM Address" gives the location in RAM the image will be 4710loaded to, and "Flash Location" gives the image's address in NOR 4711flash or offset in NAND flash. 4712 4713*Note* - these variables don't have to be defined for all boards, some 4714boards currenlty use other variables for these purposes, and some 4715boards use these variables for other purposes. 4716 4717Image File Name RAM Address Flash Location 4718----- --------- ----------- -------------- 4719u-boot u-boot u-boot_addr_r u-boot_addr 4720Linux kernel bootfile kernel_addr_r kernel_addr 4721device tree blob fdtfile fdt_addr_r fdt_addr 4722ramdisk ramdiskfile ramdisk_addr_r ramdisk_addr 4723 4724The following environment variables may be used and automatically 4725updated by the network boot commands ("bootp" and "rarpboot"), 4726depending the information provided by your boot server: 4727 4728 bootfile - see above 4729 dnsip - IP address of your Domain Name Server 4730 dnsip2 - IP address of your secondary Domain Name Server 4731 gatewayip - IP address of the Gateway (Router) to use 4732 hostname - Target hostname 4733 ipaddr - see above 4734 netmask - Subnet Mask 4735 rootpath - Pathname of the root filesystem on the NFS server 4736 serverip - see above 4737 4738 4739There are two special Environment Variables: 4740 4741 serial# - contains hardware identification information such 4742 as type string and/or serial number 4743 ethaddr - Ethernet address 4744 4745These variables can be set only once (usually during manufacturing of 4746the board). U-Boot refuses to delete or overwrite these variables 4747once they have been set once. 4748 4749 4750Further special Environment Variables: 4751 4752 ver - Contains the U-Boot version string as printed 4753 with the "version" command. This variable is 4754 readonly (see CONFIG_VERSION_VARIABLE). 4755 4756 4757Please note that changes to some configuration parameters may take 4758only effect after the next boot (yes, that's just like Windoze :-). 4759 4760 4761Callback functions for environment variables: 4762--------------------------------------------- 4763 4764For some environment variables, the behavior of u-boot needs to change 4765when their values are changed. This functionailty allows functions to 4766be associated with arbitrary variables. On creation, overwrite, or 4767deletion, the callback will provide the opportunity for some side 4768effect to happen or for the change to be rejected. 4769 4770The callbacks are named and associated with a function using the 4771U_BOOT_ENV_CALLBACK macro in your board or driver code. 4772 4773These callbacks are associated with variables in one of two ways. The 4774static list can be added to by defining CONFIG_ENV_CALLBACK_LIST_STATIC 4775in the board configuration to a string that defines a list of 4776associations. The list must be in the following format: 4777 4778 entry = variable_name[:callback_name] 4779 list = entry[,list] 4780 4781If the callback name is not specified, then the callback is deleted. 4782Spaces are also allowed anywhere in the list. 4783 4784Callbacks can also be associated by defining the ".callbacks" variable 4785with the same list format above. Any association in ".callbacks" will 4786override any association in the static list. You can define 4787CONFIG_ENV_CALLBACK_LIST_DEFAULT to a list (string) to define the 4788".callbacks" envirnoment variable in the default or embedded environment. 4789 4790 4791Command Line Parsing: 4792===================== 4793 4794There are two different command line parsers available with U-Boot: 4795the old "simple" one, and the much more powerful "hush" shell: 4796 4797Old, simple command line parser: 4798-------------------------------- 4799 4800- supports environment variables (through setenv / saveenv commands) 4801- several commands on one line, separated by ';' 4802- variable substitution using "... ${name} ..." syntax 4803- special characters ('$', ';') can be escaped by prefixing with '\', 4804 for example: 4805 setenv bootcmd bootm \${address} 4806- You can also escape text by enclosing in single apostrophes, for example: 4807 setenv addip 'setenv bootargs $bootargs ip=$ipaddr:$serverip:$gatewayip:$netmask:$hostname::off' 4808 4809Hush shell: 4810----------- 4811 4812- similar to Bourne shell, with control structures like 4813 if...then...else...fi, for...do...done; while...do...done, 4814 until...do...done, ... 4815- supports environment ("global") variables (through setenv / saveenv 4816 commands) and local shell variables (through standard shell syntax 4817 "name=value"); only environment variables can be used with "run" 4818 command 4819 4820General rules: 4821-------------- 4822 4823(1) If a command line (or an environment variable executed by a "run" 4824 command) contains several commands separated by semicolon, and 4825 one of these commands fails, then the remaining commands will be 4826 executed anyway. 4827 4828(2) If you execute several variables with one call to run (i. e. 4829 calling run with a list of variables as arguments), any failing 4830 command will cause "run" to terminate, i. e. the remaining 4831 variables are not executed. 4832 4833Note for Redundant Ethernet Interfaces: 4834======================================= 4835 4836Some boards come with redundant Ethernet interfaces; U-Boot supports 4837such configurations and is capable of automatic selection of a 4838"working" interface when needed. MAC assignment works as follows: 4839 4840Network interfaces are numbered eth0, eth1, eth2, ... Corresponding 4841MAC addresses can be stored in the environment as "ethaddr" (=>eth0), 4842"eth1addr" (=>eth1), "eth2addr", ... 4843 4844If the network interface stores some valid MAC address (for instance 4845in SROM), this is used as default address if there is NO correspon- 4846ding setting in the environment; if the corresponding environment 4847variable is set, this overrides the settings in the card; that means: 4848 4849o If the SROM has a valid MAC address, and there is no address in the 4850 environment, the SROM's address is used. 4851 4852o If there is no valid address in the SROM, and a definition in the 4853 environment exists, then the value from the environment variable is 4854 used. 4855 4856o If both the SROM and the environment contain a MAC address, and 4857 both addresses are the same, this MAC address is used. 4858 4859o If both the SROM and the environment contain a MAC address, and the 4860 addresses differ, the value from the environment is used and a 4861 warning is printed. 4862 4863o If neither SROM nor the environment contain a MAC address, an error 4864 is raised. 4865 4866If Ethernet drivers implement the 'write_hwaddr' function, valid MAC addresses 4867will be programmed into hardware as part of the initialization process. This 4868may be skipped by setting the appropriate 'ethmacskip' environment variable. 4869The naming convention is as follows: 4870"ethmacskip" (=>eth0), "eth1macskip" (=>eth1) etc. 4871 4872Image Formats: 4873============== 4874 4875U-Boot is capable of booting (and performing other auxiliary operations on) 4876images in two formats: 4877 4878New uImage format (FIT) 4879----------------------- 4880 4881Flexible and powerful format based on Flattened Image Tree -- FIT (similar 4882to Flattened Device Tree). It allows the use of images with multiple 4883components (several kernels, ramdisks, etc.), with contents protected by 4884SHA1, MD5 or CRC32. More details are found in the doc/uImage.FIT directory. 4885 4886 4887Old uImage format 4888----------------- 4889 4890Old image format is based on binary files which can be basically anything, 4891preceded by a special header; see the definitions in include/image.h for 4892details; basically, the header defines the following image properties: 4893 4894* Target Operating System (Provisions for OpenBSD, NetBSD, FreeBSD, 4895 4.4BSD, Linux, SVR4, Esix, Solaris, Irix, SCO, Dell, NCR, VxWorks, 4896 LynxOS, pSOS, QNX, RTEMS, INTEGRITY; 4897 Currently supported: Linux, NetBSD, VxWorks, QNX, RTEMS, LynxOS, 4898 INTEGRITY). 4899* Target CPU Architecture (Provisions for Alpha, ARM, AVR32, Intel x86, 4900 IA64, MIPS, NDS32, Nios II, PowerPC, IBM S390, SuperH, Sparc, Sparc 64 Bit; 4901 Currently supported: ARM, AVR32, Intel x86, MIPS, NDS32, Nios II, PowerPC). 4902* Compression Type (uncompressed, gzip, bzip2) 4903* Load Address 4904* Entry Point 4905* Image Name 4906* Image Timestamp 4907 4908The header is marked by a special Magic Number, and both the header 4909and the data portions of the image are secured against corruption by 4910CRC32 checksums. 4911 4912 4913Linux Support: 4914============== 4915 4916Although U-Boot should support any OS or standalone application 4917easily, the main focus has always been on Linux during the design of 4918U-Boot. 4919 4920U-Boot includes many features that so far have been part of some 4921special "boot loader" code within the Linux kernel. Also, any 4922"initrd" images to be used are no longer part of one big Linux image; 4923instead, kernel and "initrd" are separate images. This implementation 4924serves several purposes: 4925 4926- the same features can be used for other OS or standalone 4927 applications (for instance: using compressed images to reduce the 4928 Flash memory footprint) 4929 4930- it becomes much easier to port new Linux kernel versions because 4931 lots of low-level, hardware dependent stuff are done by U-Boot 4932 4933- the same Linux kernel image can now be used with different "initrd" 4934 images; of course this also means that different kernel images can 4935 be run with the same "initrd". This makes testing easier (you don't 4936 have to build a new "zImage.initrd" Linux image when you just 4937 change a file in your "initrd"). Also, a field-upgrade of the 4938 software is easier now. 4939 4940 4941Linux HOWTO: 4942============ 4943 4944Porting Linux to U-Boot based systems: 4945--------------------------------------- 4946 4947U-Boot cannot save you from doing all the necessary modifications to 4948configure the Linux device drivers for use with your target hardware 4949(no, we don't intend to provide a full virtual machine interface to 4950Linux :-). 4951 4952But now you can ignore ALL boot loader code (in arch/powerpc/mbxboot). 4953 4954Just make sure your machine specific header file (for instance 4955include/asm-ppc/tqm8xx.h) includes the same definition of the Board 4956Information structure as we define in include/asm-<arch>/u-boot.h, 4957and make sure that your definition of IMAP_ADDR uses the same value 4958as your U-Boot configuration in CONFIG_SYS_IMMR. 4959 4960 4961Configuring the Linux kernel: 4962----------------------------- 4963 4964No specific requirements for U-Boot. Make sure you have some root 4965device (initial ramdisk, NFS) for your target system. 4966 4967 4968Building a Linux Image: 4969----------------------- 4970 4971With U-Boot, "normal" build targets like "zImage" or "bzImage" are 4972not used. If you use recent kernel source, a new build target 4973"uImage" will exist which automatically builds an image usable by 4974U-Boot. Most older kernels also have support for a "pImage" target, 4975which was introduced for our predecessor project PPCBoot and uses a 4976100% compatible format. 4977 4978Example: 4979 4980 make TQM850L_config 4981 make oldconfig 4982 make dep 4983 make uImage 4984 4985The "uImage" build target uses a special tool (in 'tools/mkimage') to 4986encapsulate a compressed Linux kernel image with header information, 4987CRC32 checksum etc. for use with U-Boot. This is what we are doing: 4988 4989* build a standard "vmlinux" kernel image (in ELF binary format): 4990 4991* convert the kernel into a raw binary image: 4992 4993 ${CROSS_COMPILE}-objcopy -O binary \ 4994 -R .note -R .comment \ 4995 -S vmlinux linux.bin 4996 4997* compress the binary image: 4998 4999 gzip -9 linux.bin 5000 5001* package compressed binary image for U-Boot: 5002 5003 mkimage -A ppc -O linux -T kernel -C gzip \ 5004 -a 0 -e 0 -n "Linux Kernel Image" \ 5005 -d linux.bin.gz uImage 5006 5007 5008The "mkimage" tool can also be used to create ramdisk images for use 5009with U-Boot, either separated from the Linux kernel image, or 5010combined into one file. "mkimage" encapsulates the images with a 64 5011byte header containing information about target architecture, 5012operating system, image type, compression method, entry points, time 5013stamp, CRC32 checksums, etc. 5014 5015"mkimage" can be called in two ways: to verify existing images and 5016print the header information, or to build new images. 5017 5018In the first form (with "-l" option) mkimage lists the information 5019contained in the header of an existing U-Boot image; this includes 5020checksum verification: 5021 5022 tools/mkimage -l image 5023 -l ==> list image header information 5024 5025The second form (with "-d" option) is used to build a U-Boot image 5026from a "data file" which is used as image payload: 5027 5028 tools/mkimage -A arch -O os -T type -C comp -a addr -e ep \ 5029 -n name -d data_file image 5030 -A ==> set architecture to 'arch' 5031 -O ==> set operating system to 'os' 5032 -T ==> set image type to 'type' 5033 -C ==> set compression type 'comp' 5034 -a ==> set load address to 'addr' (hex) 5035 -e ==> set entry point to 'ep' (hex) 5036 -n ==> set image name to 'name' 5037 -d ==> use image data from 'datafile' 5038 5039Right now, all Linux kernels for PowerPC systems use the same load 5040address (0x00000000), but the entry point address depends on the 5041kernel version: 5042 5043- 2.2.x kernels have the entry point at 0x0000000C, 5044- 2.3.x and later kernels have the entry point at 0x00000000. 5045 5046So a typical call to build a U-Boot image would read: 5047 5048 -> tools/mkimage -n '2.4.4 kernel for TQM850L' \ 5049 > -A ppc -O linux -T kernel -C gzip -a 0 -e 0 \ 5050 > -d /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/powerpc/coffboot/vmlinux.gz \ 5051 > examples/uImage.TQM850L 5052 Image Name: 2.4.4 kernel for TQM850L 5053 Created: Wed Jul 19 02:34:59 2000 5054 Image Type: PowerPC Linux Kernel Image (gzip compressed) 5055 Data Size: 335725 Bytes = 327.86 kB = 0.32 MB 5056 Load Address: 0x00000000 5057 Entry Point: 0x00000000 5058 5059To verify the contents of the image (or check for corruption): 5060 5061 -> tools/mkimage -l examples/uImage.TQM850L 5062 Image Name: 2.4.4 kernel for TQM850L 5063 Created: Wed Jul 19 02:34:59 2000 5064 Image Type: PowerPC Linux Kernel Image (gzip compressed) 5065 Data Size: 335725 Bytes = 327.86 kB = 0.32 MB 5066 Load Address: 0x00000000 5067 Entry Point: 0x00000000 5068 5069NOTE: for embedded systems where boot time is critical you can trade 5070speed for memory and install an UNCOMPRESSED image instead: this 5071needs more space in Flash, but boots much faster since it does not 5072need to be uncompressed: 5073 5074 -> gunzip /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/powerpc/coffboot/vmlinux.gz 5075 -> tools/mkimage -n '2.4.4 kernel for TQM850L' \ 5076 > -A ppc -O linux -T kernel -C none -a 0 -e 0 \ 5077 > -d /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/powerpc/coffboot/vmlinux \ 5078 > examples/uImage.TQM850L-uncompressed 5079 Image Name: 2.4.4 kernel for TQM850L 5080 Created: Wed Jul 19 02:34:59 2000 5081 Image Type: PowerPC Linux Kernel Image (uncompressed) 5082 Data Size: 792160 Bytes = 773.59 kB = 0.76 MB 5083 Load Address: 0x00000000 5084 Entry Point: 0x00000000 5085 5086 5087Similar you can build U-Boot images from a 'ramdisk.image.gz' file 5088when your kernel is intended to use an initial ramdisk: 5089 5090 -> tools/mkimage -n 'Simple Ramdisk Image' \ 5091 > -A ppc -O linux -T ramdisk -C gzip \ 5092 > -d /LinuxPPC/images/SIMPLE-ramdisk.image.gz examples/simple-initrd 5093 Image Name: Simple Ramdisk Image 5094 Created: Wed Jan 12 14:01:50 2000 5095 Image Type: PowerPC Linux RAMDisk Image (gzip compressed) 5096 Data Size: 566530 Bytes = 553.25 kB = 0.54 MB 5097 Load Address: 0x00000000 5098 Entry Point: 0x00000000 5099 5100 5101Installing a Linux Image: 5102------------------------- 5103 5104To downloading a U-Boot image over the serial (console) interface, 5105you must convert the image to S-Record format: 5106 5107 objcopy -I binary -O srec examples/image examples/image.srec 5108 5109The 'objcopy' does not understand the information in the U-Boot 5110image header, so the resulting S-Record file will be relative to 5111address 0x00000000. To load it to a given address, you need to 5112specify the target address as 'offset' parameter with the 'loads' 5113command. 5114 5115Example: install the image to address 0x40100000 (which on the 5116TQM8xxL is in the first Flash bank): 5117 5118 => erase 40100000 401FFFFF 5119 5120 .......... done 5121 Erased 8 sectors 5122 5123 => loads 40100000 5124 ## Ready for S-Record download ... 5125 ~>examples/image.srec 5126 1 2 3 4 5 6 7 8 9 10 11 12 13 ... 5127 ... 5128 15989 15990 15991 15992 5129 [file transfer complete] 5130 [connected] 5131 ## Start Addr = 0x00000000 5132 5133 5134You can check the success of the download using the 'iminfo' command; 5135this includes a checksum verification so you can be sure no data 5136corruption happened: 5137 5138 => imi 40100000 5139 5140 ## Checking Image at 40100000 ... 5141 Image Name: 2.2.13 for initrd on TQM850L 5142 Image Type: PowerPC Linux Kernel Image (gzip compressed) 5143 Data Size: 335725 Bytes = 327 kB = 0 MB 5144 Load Address: 00000000 5145 Entry Point: 0000000c 5146 Verifying Checksum ... OK 5147 5148 5149Boot Linux: 5150----------- 5151 5152The "bootm" command is used to boot an application that is stored in 5153memory (RAM or Flash). In case of a Linux kernel image, the contents 5154of the "bootargs" environment variable is passed to the kernel as 5155parameters. You can check and modify this variable using the 5156"printenv" and "setenv" commands: 5157 5158 5159 => printenv bootargs 5160 bootargs=root=/dev/ram 5161 5162 => setenv bootargs root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2 5163 5164 => printenv bootargs 5165 bootargs=root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2 5166 5167 => bootm 40020000 5168 ## Booting Linux kernel at 40020000 ... 5169 Image Name: 2.2.13 for NFS on TQM850L 5170 Image Type: PowerPC Linux Kernel Image (gzip compressed) 5171 Data Size: 381681 Bytes = 372 kB = 0 MB 5172 Load Address: 00000000 5173 Entry Point: 0000000c 5174 Verifying Checksum ... OK 5175 Uncompressing Kernel Image ... OK 5176 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 5177 Boot arguments: root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2 5178 time_init: decrementer frequency = 187500000/60 5179 Calibrating delay loop... 49.77 BogoMIPS 5180 Memory: 15208k available (700k kernel code, 444k data, 32k init) [c0000000,c1000000] 5181 ... 5182 5183If you want to boot a Linux kernel with initial RAM disk, you pass 5184the memory addresses of both the kernel and the initrd image (PPBCOOT 5185format!) to the "bootm" command: 5186 5187 => imi 40100000 40200000 5188 5189 ## Checking Image at 40100000 ... 5190 Image Name: 2.2.13 for initrd on TQM850L 5191 Image Type: PowerPC Linux Kernel Image (gzip compressed) 5192 Data Size: 335725 Bytes = 327 kB = 0 MB 5193 Load Address: 00000000 5194 Entry Point: 0000000c 5195 Verifying Checksum ... OK 5196 5197 ## Checking Image at 40200000 ... 5198 Image Name: Simple Ramdisk Image 5199 Image Type: PowerPC Linux RAMDisk Image (gzip compressed) 5200 Data Size: 566530 Bytes = 553 kB = 0 MB 5201 Load Address: 00000000 5202 Entry Point: 00000000 5203 Verifying Checksum ... OK 5204 5205 => bootm 40100000 40200000 5206 ## Booting Linux kernel at 40100000 ... 5207 Image Name: 2.2.13 for initrd on TQM850L 5208 Image Type: PowerPC Linux Kernel Image (gzip compressed) 5209 Data Size: 335725 Bytes = 327 kB = 0 MB 5210 Load Address: 00000000 5211 Entry Point: 0000000c 5212 Verifying Checksum ... OK 5213 Uncompressing Kernel Image ... OK 5214 ## Loading RAMDisk Image at 40200000 ... 5215 Image Name: Simple Ramdisk Image 5216 Image Type: PowerPC Linux RAMDisk Image (gzip compressed) 5217 Data Size: 566530 Bytes = 553 kB = 0 MB 5218 Load Address: 00000000 5219 Entry Point: 00000000 5220 Verifying Checksum ... OK 5221 Loading Ramdisk ... OK 5222 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 5223 Boot arguments: root=/dev/ram 5224 time_init: decrementer frequency = 187500000/60 5225 Calibrating delay loop... 49.77 BogoMIPS 5226 ... 5227 RAMDISK: Compressed image found at block 0 5228 VFS: Mounted root (ext2 filesystem). 5229 5230 bash# 5231 5232Boot Linux and pass a flat device tree: 5233----------- 5234 5235First, U-Boot must be compiled with the appropriate defines. See the section 5236titled "Linux Kernel Interface" above for a more in depth explanation. The 5237following is an example of how to start a kernel and pass an updated 5238flat device tree: 5239 5240=> print oftaddr 5241oftaddr=0x300000 5242=> print oft 5243oft=oftrees/mpc8540ads.dtb 5244=> tftp $oftaddr $oft 5245Speed: 1000, full duplex 5246Using TSEC0 device 5247TFTP from server 192.168.1.1; our IP address is 192.168.1.101 5248Filename 'oftrees/mpc8540ads.dtb'. 5249Load address: 0x300000 5250Loading: # 5251done 5252Bytes transferred = 4106 (100a hex) 5253=> tftp $loadaddr $bootfile 5254Speed: 1000, full duplex 5255Using TSEC0 device 5256TFTP from server 192.168.1.1; our IP address is 192.168.1.2 5257Filename 'uImage'. 5258Load address: 0x200000 5259Loading:############ 5260done 5261Bytes transferred = 1029407 (fb51f hex) 5262=> print loadaddr 5263loadaddr=200000 5264=> print oftaddr 5265oftaddr=0x300000 5266=> bootm $loadaddr - $oftaddr 5267## Booting image at 00200000 ... 5268 Image Name: Linux-2.6.17-dirty 5269 Image Type: PowerPC Linux Kernel Image (gzip compressed) 5270 Data Size: 1029343 Bytes = 1005.2 kB 5271 Load Address: 00000000 5272 Entry Point: 00000000 5273 Verifying Checksum ... OK 5274 Uncompressing Kernel Image ... OK 5275Booting using flat device tree at 0x300000 5276Using MPC85xx ADS machine description 5277Memory CAM mapping: CAM0=256Mb, CAM1=256Mb, CAM2=0Mb residual: 0Mb 5278[snip] 5279 5280 5281More About U-Boot Image Types: 5282------------------------------ 5283 5284U-Boot supports the following image types: 5285 5286 "Standalone Programs" are directly runnable in the environment 5287 provided by U-Boot; it is expected that (if they behave 5288 well) you can continue to work in U-Boot after return from 5289 the Standalone Program. 5290 "OS Kernel Images" are usually images of some Embedded OS which 5291 will take over control completely. Usually these programs 5292 will install their own set of exception handlers, device 5293 drivers, set up the MMU, etc. - this means, that you cannot 5294 expect to re-enter U-Boot except by resetting the CPU. 5295 "RAMDisk Images" are more or less just data blocks, and their 5296 parameters (address, size) are passed to an OS kernel that is 5297 being started. 5298 "Multi-File Images" contain several images, typically an OS 5299 (Linux) kernel image and one or more data images like 5300 RAMDisks. This construct is useful for instance when you want 5301 to boot over the network using BOOTP etc., where the boot 5302 server provides just a single image file, but you want to get 5303 for instance an OS kernel and a RAMDisk image. 5304 5305 "Multi-File Images" start with a list of image sizes, each 5306 image size (in bytes) specified by an "uint32_t" in network 5307 byte order. This list is terminated by an "(uint32_t)0". 5308 Immediately after the terminating 0 follow the images, one by 5309 one, all aligned on "uint32_t" boundaries (size rounded up to 5310 a multiple of 4 bytes). 5311 5312 "Firmware Images" are binary images containing firmware (like 5313 U-Boot or FPGA images) which usually will be programmed to 5314 flash memory. 5315 5316 "Script files" are command sequences that will be executed by 5317 U-Boot's command interpreter; this feature is especially 5318 useful when you configure U-Boot to use a real shell (hush) 5319 as command interpreter. 5320 5321Booting the Linux zImage: 5322------------------------- 5323 5324On some platforms, it's possible to boot Linux zImage. This is done 5325using the "bootz" command. The syntax of "bootz" command is the same 5326as the syntax of "bootm" command. 5327 5328Note, defining the CONFIG_SUPPORT_RAW_INITRD allows user to supply 5329kernel with raw initrd images. The syntax is slightly different, the 5330address of the initrd must be augmented by it's size, in the following 5331format: "<initrd addres>:<initrd size>". 5332 5333 5334Standalone HOWTO: 5335================= 5336 5337One of the features of U-Boot is that you can dynamically load and 5338run "standalone" applications, which can use some resources of 5339U-Boot like console I/O functions or interrupt services. 5340 5341Two simple examples are included with the sources: 5342 5343"Hello World" Demo: 5344------------------- 5345 5346'examples/hello_world.c' contains a small "Hello World" Demo 5347application; it is automatically compiled when you build U-Boot. 5348It's configured to run at address 0x00040004, so you can play with it 5349like that: 5350 5351 => loads 5352 ## Ready for S-Record download ... 5353 ~>examples/hello_world.srec 5354 1 2 3 4 5 6 7 8 9 10 11 ... 5355 [file transfer complete] 5356 [connected] 5357 ## Start Addr = 0x00040004 5358 5359 => go 40004 Hello World! This is a test. 5360 ## Starting application at 0x00040004 ... 5361 Hello World 5362 argc = 7 5363 argv[0] = "40004" 5364 argv[1] = "Hello" 5365 argv[2] = "World!" 5366 argv[3] = "This" 5367 argv[4] = "is" 5368 argv[5] = "a" 5369 argv[6] = "test." 5370 argv[7] = "<NULL>" 5371 Hit any key to exit ... 5372 5373 ## Application terminated, rc = 0x0 5374 5375Another example, which demonstrates how to register a CPM interrupt 5376handler with the U-Boot code, can be found in 'examples/timer.c'. 5377Here, a CPM timer is set up to generate an interrupt every second. 5378The interrupt service routine is trivial, just printing a '.' 5379character, but this is just a demo program. The application can be 5380controlled by the following keys: 5381 5382 ? - print current values og the CPM Timer registers 5383 b - enable interrupts and start timer 5384 e - stop timer and disable interrupts 5385 q - quit application 5386 5387 => loads 5388 ## Ready for S-Record download ... 5389 ~>examples/timer.srec 5390 1 2 3 4 5 6 7 8 9 10 11 ... 5391 [file transfer complete] 5392 [connected] 5393 ## Start Addr = 0x00040004 5394 5395 => go 40004 5396 ## Starting application at 0x00040004 ... 5397 TIMERS=0xfff00980 5398 Using timer 1 5399 tgcr @ 0xfff00980, tmr @ 0xfff00990, trr @ 0xfff00994, tcr @ 0xfff00998, tcn @ 0xfff0099c, ter @ 0xfff009b0 5400 5401Hit 'b': 5402 [q, b, e, ?] Set interval 1000000 us 5403 Enabling timer 5404Hit '?': 5405 [q, b, e, ?] ........ 5406 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0xef6, ter=0x0 5407Hit '?': 5408 [q, b, e, ?] . 5409 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x2ad4, ter=0x0 5410Hit '?': 5411 [q, b, e, ?] . 5412 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x1efc, ter=0x0 5413Hit '?': 5414 [q, b, e, ?] . 5415 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x169d, ter=0x0 5416Hit 'e': 5417 [q, b, e, ?] ...Stopping timer 5418Hit 'q': 5419 [q, b, e, ?] ## Application terminated, rc = 0x0 5420 5421 5422Minicom warning: 5423================ 5424 5425Over time, many people have reported problems when trying to use the 5426"minicom" terminal emulation program for serial download. I (wd) 5427consider minicom to be broken, and recommend not to use it. Under 5428Unix, I recommend to use C-Kermit for general purpose use (and 5429especially for kermit binary protocol download ("loadb" command), and 5430use "cu" for S-Record download ("loads" command). See 5431http://www.denx.de/wiki/view/DULG/SystemSetup#Section_4.3. 5432for help with kermit. 5433 5434 5435Nevertheless, if you absolutely want to use it try adding this 5436configuration to your "File transfer protocols" section: 5437 5438 Name Program Name U/D FullScr IO-Red. Multi 5439 X kermit /usr/bin/kermit -i -l %l -s Y U Y N N 5440 Y kermit /usr/bin/kermit -i -l %l -r N D Y N N 5441 5442 5443NetBSD Notes: 5444============= 5445 5446Starting at version 0.9.2, U-Boot supports NetBSD both as host 5447(build U-Boot) and target system (boots NetBSD/mpc8xx). 5448 5449Building requires a cross environment; it is known to work on 5450NetBSD/i386 with the cross-powerpc-netbsd-1.3 package (you will also 5451need gmake since the Makefiles are not compatible with BSD make). 5452Note that the cross-powerpc package does not install include files; 5453attempting to build U-Boot will fail because <machine/ansi.h> is 5454missing. This file has to be installed and patched manually: 5455 5456 # cd /usr/pkg/cross/powerpc-netbsd/include 5457 # mkdir powerpc 5458 # ln -s powerpc machine 5459 # cp /usr/src/sys/arch/powerpc/include/ansi.h powerpc/ansi.h 5460 # ${EDIT} powerpc/ansi.h ## must remove __va_list, _BSD_VA_LIST 5461 5462Native builds *don't* work due to incompatibilities between native 5463and U-Boot include files. 5464 5465Booting assumes that (the first part of) the image booted is a 5466stage-2 loader which in turn loads and then invokes the kernel 5467proper. Loader sources will eventually appear in the NetBSD source 5468tree (probably in sys/arc/mpc8xx/stand/u-boot_stage2/); in the 5469meantime, see ftp://ftp.denx.de/pub/u-boot/ppcboot_stage2.tar.gz 5470 5471 5472Implementation Internals: 5473========================= 5474 5475The following is not intended to be a complete description of every 5476implementation detail. However, it should help to understand the 5477inner workings of U-Boot and make it easier to port it to custom 5478hardware. 5479 5480 5481Initial Stack, Global Data: 5482--------------------------- 5483 5484The implementation of U-Boot is complicated by the fact that U-Boot 5485starts running out of ROM (flash memory), usually without access to 5486system RAM (because the memory controller is not initialized yet). 5487This means that we don't have writable Data or BSS segments, and BSS 5488is not initialized as zero. To be able to get a C environment working 5489at all, we have to allocate at least a minimal stack. Implementation 5490options for this are defined and restricted by the CPU used: Some CPU 5491models provide on-chip memory (like the IMMR area on MPC8xx and 5492MPC826x processors), on others (parts of) the data cache can be 5493locked as (mis-) used as memory, etc. 5494 5495 Chris Hallinan posted a good summary of these issues to the 5496 U-Boot mailing list: 5497 5498 Subject: RE: [U-Boot-Users] RE: More On Memory Bank x (nothingness)? 5499 From: "Chris Hallinan" <clh@net1plus.com> 5500 Date: Mon, 10 Feb 2003 16:43:46 -0500 (22:43 MET) 5501 ... 5502 5503 Correct me if I'm wrong, folks, but the way I understand it 5504 is this: Using DCACHE as initial RAM for Stack, etc, does not 5505 require any physical RAM backing up the cache. The cleverness 5506 is that the cache is being used as a temporary supply of 5507 necessary storage before the SDRAM controller is setup. It's 5508 beyond the scope of this list to explain the details, but you 5509 can see how this works by studying the cache architecture and 5510 operation in the architecture and processor-specific manuals. 5511 5512 OCM is On Chip Memory, which I believe the 405GP has 4K. It 5513 is another option for the system designer to use as an 5514 initial stack/RAM area prior to SDRAM being available. Either 5515 option should work for you. Using CS 4 should be fine if your 5516 board designers haven't used it for something that would 5517 cause you grief during the initial boot! It is frequently not 5518 used. 5519 5520 CONFIG_SYS_INIT_RAM_ADDR should be somewhere that won't interfere 5521 with your processor/board/system design. The default value 5522 you will find in any recent u-boot distribution in 5523 walnut.h should work for you. I'd set it to a value larger 5524 than your SDRAM module. If you have a 64MB SDRAM module, set 5525 it above 400_0000. Just make sure your board has no resources 5526 that are supposed to respond to that address! That code in 5527 start.S has been around a while and should work as is when 5528 you get the config right. 5529 5530 -Chris Hallinan 5531 DS4.COM, Inc. 5532 5533It is essential to remember this, since it has some impact on the C 5534code for the initialization procedures: 5535 5536* Initialized global data (data segment) is read-only. Do not attempt 5537 to write it. 5538 5539* Do not use any uninitialized global data (or implicitely initialized 5540 as zero data - BSS segment) at all - this is undefined, initiali- 5541 zation is performed later (when relocating to RAM). 5542 5543* Stack space is very limited. Avoid big data buffers or things like 5544 that. 5545 5546Having only the stack as writable memory limits means we cannot use 5547normal global data to share information beween the code. But it 5548turned out that the implementation of U-Boot can be greatly 5549simplified by making a global data structure (gd_t) available to all 5550functions. We could pass a pointer to this data as argument to _all_ 5551functions, but this would bloat the code. Instead we use a feature of 5552the GCC compiler (Global Register Variables) to share the data: we 5553place a pointer (gd) to the global data into a register which we 5554reserve for this purpose. 5555 5556When choosing a register for such a purpose we are restricted by the 5557relevant (E)ABI specifications for the current architecture, and by 5558GCC's implementation. 5559 5560For PowerPC, the following registers have specific use: 5561 R1: stack pointer 5562 R2: reserved for system use 5563 R3-R4: parameter passing and return values 5564 R5-R10: parameter passing 5565 R13: small data area pointer 5566 R30: GOT pointer 5567 R31: frame pointer 5568 5569 (U-Boot also uses R12 as internal GOT pointer. r12 5570 is a volatile register so r12 needs to be reset when 5571 going back and forth between asm and C) 5572 5573 ==> U-Boot will use R2 to hold a pointer to the global data 5574 5575 Note: on PPC, we could use a static initializer (since the 5576 address of the global data structure is known at compile time), 5577 but it turned out that reserving a register results in somewhat 5578 smaller code - although the code savings are not that big (on 5579 average for all boards 752 bytes for the whole U-Boot image, 5580 624 text + 127 data). 5581 5582On Blackfin, the normal C ABI (except for P3) is followed as documented here: 5583 http://docs.blackfin.uclinux.org/doku.php?id=application_binary_interface 5584 5585 ==> U-Boot will use P3 to hold a pointer to the global data 5586 5587On ARM, the following registers are used: 5588 5589 R0: function argument word/integer result 5590 R1-R3: function argument word 5591 R9: GOT pointer 5592 R10: stack limit (used only if stack checking if enabled) 5593 R11: argument (frame) pointer 5594 R12: temporary workspace 5595 R13: stack pointer 5596 R14: link register 5597 R15: program counter 5598 5599 ==> U-Boot will use R8 to hold a pointer to the global data 5600 5601On Nios II, the ABI is documented here: 5602 http://www.altera.com/literature/hb/nios2/n2cpu_nii51016.pdf 5603 5604 ==> U-Boot will use gp to hold a pointer to the global data 5605 5606 Note: on Nios II, we give "-G0" option to gcc and don't use gp 5607 to access small data sections, so gp is free. 5608 5609On NDS32, the following registers are used: 5610 5611 R0-R1: argument/return 5612 R2-R5: argument 5613 R15: temporary register for assembler 5614 R16: trampoline register 5615 R28: frame pointer (FP) 5616 R29: global pointer (GP) 5617 R30: link register (LP) 5618 R31: stack pointer (SP) 5619 PC: program counter (PC) 5620 5621 ==> U-Boot will use R10 to hold a pointer to the global data 5622 5623NOTE: DECLARE_GLOBAL_DATA_PTR must be used with file-global scope, 5624or current versions of GCC may "optimize" the code too much. 5625 5626Memory Management: 5627------------------ 5628 5629U-Boot runs in system state and uses physical addresses, i.e. the 5630MMU is not used either for address mapping nor for memory protection. 5631 5632The available memory is mapped to fixed addresses using the memory 5633controller. In this process, a contiguous block is formed for each 5634memory type (Flash, SDRAM, SRAM), even when it consists of several 5635physical memory banks. 5636 5637U-Boot is installed in the first 128 kB of the first Flash bank (on 5638TQM8xxL modules this is the range 0x40000000 ... 0x4001FFFF). After 5639booting and sizing and initializing DRAM, the code relocates itself 5640to the upper end of DRAM. Immediately below the U-Boot code some 5641memory is reserved for use by malloc() [see CONFIG_SYS_MALLOC_LEN 5642configuration setting]. Below that, a structure with global Board 5643Info data is placed, followed by the stack (growing downward). 5644 5645Additionally, some exception handler code is copied to the low 8 kB 5646of DRAM (0x00000000 ... 0x00001FFF). 5647 5648So a typical memory configuration with 16 MB of DRAM could look like 5649this: 5650 5651 0x0000 0000 Exception Vector code 5652 : 5653 0x0000 1FFF 5654 0x0000 2000 Free for Application Use 5655 : 5656 : 5657 5658 : 5659 : 5660 0x00FB FF20 Monitor Stack (Growing downward) 5661 0x00FB FFAC Board Info Data and permanent copy of global data 5662 0x00FC 0000 Malloc Arena 5663 : 5664 0x00FD FFFF 5665 0x00FE 0000 RAM Copy of Monitor Code 5666 ... eventually: LCD or video framebuffer 5667 ... eventually: pRAM (Protected RAM - unchanged by reset) 5668 0x00FF FFFF [End of RAM] 5669 5670 5671System Initialization: 5672---------------------- 5673 5674In the reset configuration, U-Boot starts at the reset entry point 5675(on most PowerPC systems at address 0x00000100). Because of the reset 5676configuration for CS0# this is a mirror of the onboard Flash memory. 5677To be able to re-map memory U-Boot then jumps to its link address. 5678To be able to implement the initialization code in C, a (small!) 5679initial stack is set up in the internal Dual Ported RAM (in case CPUs 5680which provide such a feature like MPC8xx or MPC8260), or in a locked 5681part of the data cache. After that, U-Boot initializes the CPU core, 5682the caches and the SIU. 5683 5684Next, all (potentially) available memory banks are mapped using a 5685preliminary mapping. For example, we put them on 512 MB boundaries 5686(multiples of 0x20000000: SDRAM on 0x00000000 and 0x20000000, Flash 5687on 0x40000000 and 0x60000000, SRAM on 0x80000000). Then UPM A is 5688programmed for SDRAM access. Using the temporary configuration, a 5689simple memory test is run that determines the size of the SDRAM 5690banks. 5691 5692When there is more than one SDRAM bank, and the banks are of 5693different size, the largest is mapped first. For equal size, the first 5694bank (CS2#) is mapped first. The first mapping is always for address 56950x00000000, with any additional banks following immediately to create 5696contiguous memory starting from 0. 5697 5698Then, the monitor installs itself at the upper end of the SDRAM area 5699and allocates memory for use by malloc() and for the global Board 5700Info data; also, the exception vector code is copied to the low RAM 5701pages, and the final stack is set up. 5702 5703Only after this relocation will you have a "normal" C environment; 5704until that you are restricted in several ways, mostly because you are 5705running from ROM, and because the code will have to be relocated to a 5706new address in RAM. 5707 5708 5709U-Boot Porting Guide: 5710---------------------- 5711 5712[Based on messages by Jerry Van Baren in the U-Boot-Users mailing 5713list, October 2002] 5714 5715 5716int main(int argc, char *argv[]) 5717{ 5718 sighandler_t no_more_time; 5719 5720 signal(SIGALRM, no_more_time); 5721 alarm(PROJECT_DEADLINE - toSec (3 * WEEK)); 5722 5723 if (available_money > available_manpower) { 5724 Pay consultant to port U-Boot; 5725 return 0; 5726 } 5727 5728 Download latest U-Boot source; 5729 5730 Subscribe to u-boot mailing list; 5731 5732 if (clueless) 5733 email("Hi, I am new to U-Boot, how do I get started?"); 5734 5735 while (learning) { 5736 Read the README file in the top level directory; 5737 Read http://www.denx.de/twiki/bin/view/DULG/Manual; 5738 Read applicable doc/*.README; 5739 Read the source, Luke; 5740 /* find . -name "*.[chS]" | xargs grep -i <keyword> */ 5741 } 5742 5743 if (available_money > toLocalCurrency ($2500)) 5744 Buy a BDI3000; 5745 else 5746 Add a lot of aggravation and time; 5747 5748 if (a similar board exists) { /* hopefully... */ 5749 cp -a board/<similar> board/<myboard> 5750 cp include/configs/<similar>.h include/configs/<myboard>.h 5751 } else { 5752 Create your own board support subdirectory; 5753 Create your own board include/configs/<myboard>.h file; 5754 } 5755 Edit new board/<myboard> files 5756 Edit new include/configs/<myboard>.h 5757 5758 while (!accepted) { 5759 while (!running) { 5760 do { 5761 Add / modify source code; 5762 } until (compiles); 5763 Debug; 5764 if (clueless) 5765 email("Hi, I am having problems..."); 5766 } 5767 Send patch file to the U-Boot email list; 5768 if (reasonable critiques) 5769 Incorporate improvements from email list code review; 5770 else 5771 Defend code as written; 5772 } 5773 5774 return 0; 5775} 5776 5777void no_more_time (int sig) 5778{ 5779 hire_a_guru(); 5780} 5781 5782 5783Coding Standards: 5784----------------- 5785 5786All contributions to U-Boot should conform to the Linux kernel 5787coding style; see the file "Documentation/CodingStyle" and the script 5788"scripts/Lindent" in your Linux kernel source directory. 5789 5790Source files originating from a different project (for example the 5791MTD subsystem) are generally exempt from these guidelines and are not 5792reformated to ease subsequent migration to newer versions of those 5793sources. 5794 5795Please note that U-Boot is implemented in C (and to some small parts in 5796Assembler); no C++ is used, so please do not use C++ style comments (//) 5797in your code. 5798 5799Please also stick to the following formatting rules: 5800- remove any trailing white space 5801- use TAB characters for indentation and vertical alignment, not spaces 5802- make sure NOT to use DOS '\r\n' line feeds 5803- do not add more than 2 consecutive empty lines to source files 5804- do not add trailing empty lines to source files 5805 5806Submissions which do not conform to the standards may be returned 5807with a request to reformat the changes. 5808 5809 5810Submitting Patches: 5811------------------- 5812 5813Since the number of patches for U-Boot is growing, we need to 5814establish some rules. Submissions which do not conform to these rules 5815may be rejected, even when they contain important and valuable stuff. 5816 5817Please see http://www.denx.de/wiki/U-Boot/Patches for details. 5818 5819Patches shall be sent to the u-boot mailing list <u-boot@lists.denx.de>; 5820see http://lists.denx.de/mailman/listinfo/u-boot 5821 5822When you send a patch, please include the following information with 5823it: 5824 5825* For bug fixes: a description of the bug and how your patch fixes 5826 this bug. Please try to include a way of demonstrating that the 5827 patch actually fixes something. 5828 5829* For new features: a description of the feature and your 5830 implementation. 5831 5832* A CHANGELOG entry as plaintext (separate from the patch) 5833 5834* For major contributions, your entry to the CREDITS file 5835 5836* When you add support for a new board, don't forget to add a 5837 maintainer e-mail address to the boards.cfg file, too. 5838 5839* If your patch adds new configuration options, don't forget to 5840 document these in the README file. 5841 5842* The patch itself. If you are using git (which is *strongly* 5843 recommended) you can easily generate the patch using the 5844 "git format-patch". If you then use "git send-email" to send it to 5845 the U-Boot mailing list, you will avoid most of the common problems 5846 with some other mail clients. 5847 5848 If you cannot use git, use "diff -purN OLD NEW". If your version of 5849 diff does not support these options, then get the latest version of 5850 GNU diff. 5851 5852 The current directory when running this command shall be the parent 5853 directory of the U-Boot source tree (i. e. please make sure that 5854 your patch includes sufficient directory information for the 5855 affected files). 5856 5857 We prefer patches as plain text. MIME attachments are discouraged, 5858 and compressed attachments must not be used. 5859 5860* If one logical set of modifications affects or creates several 5861 files, all these changes shall be submitted in a SINGLE patch file. 5862 5863* Changesets that contain different, unrelated modifications shall be 5864 submitted as SEPARATE patches, one patch per changeset. 5865 5866 5867Notes: 5868 5869* Before sending the patch, run the MAKEALL script on your patched 5870 source tree and make sure that no errors or warnings are reported 5871 for any of the boards. 5872 5873* Keep your modifications to the necessary minimum: A patch 5874 containing several unrelated changes or arbitrary reformats will be 5875 returned with a request to re-formatting / split it. 5876 5877* If you modify existing code, make sure that your new code does not 5878 add to the memory footprint of the code ;-) Small is beautiful! 5879 When adding new features, these should compile conditionally only 5880 (using #ifdef), and the resulting code with the new feature 5881 disabled must not need more memory than the old code without your 5882 modification. 5883 5884* Remember that there is a size limit of 100 kB per message on the 5885 u-boot mailing list. Bigger patches will be moderated. If they are 5886 reasonable and not too big, they will be acknowledged. But patches 5887 bigger than the size limit should be avoided. 5888