1# 2# (C) Copyright 2000 - 2009 3# Wolfgang Denk, DENX Software Engineering, wd@denx.de. 4# 5# See file CREDITS for list of people who contributed to this 6# project. 7# 8# This program is free software; you can redistribute it and/or 9# modify it under the terms of the GNU General Public License as 10# published by the Free Software Foundation; either version 2 of 11# the License, or (at your option) any later version. 12# 13# This program is distributed in the hope that it will be useful, 14# but WITHOUT ANY WARRANTY; without even the implied warranty of 15# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 16# GNU General Public License for more details. 17# 18# You should have received a copy of the GNU General Public License 19# along with this program; if not, write to the Free Software 20# Foundation, Inc., 59 Temple Place, Suite 330, Boston, 21# MA 02111-1307 USA 22# 23 24Summary: 25======== 26 27This directory contains the source code for U-Boot, a boot loader for 28Embedded boards based on PowerPC, ARM, MIPS and several other 29processors, which can be installed in a boot ROM and used to 30initialize and test the hardware or to download and run application 31code. 32 33The development of U-Boot is closely related to Linux: some parts of 34the source code originate in the Linux source tree, we have some 35header files in common, and special provision has been made to 36support booting of Linux images. 37 38Some attention has been paid to make this software easily 39configurable and extendable. For instance, all monitor commands are 40implemented with the same call interface, so that it's very easy to 41add new commands. Also, instead of permanently adding rarely used 42code (for instance hardware test utilities) to the monitor, you can 43load and run it dynamically. 44 45 46Status: 47======= 48 49In general, all boards for which a configuration option exists in the 50Makefile have been tested to some extent and can be considered 51"working". In fact, many of them are used in production systems. 52 53In case of problems see the CHANGELOG and CREDITS files to find out 54who contributed the specific port. The MAINTAINERS file lists board 55maintainers. 56 57 58Where to get help: 59================== 60 61In case you have questions about, problems with or contributions for 62U-Boot you should send a message to the U-Boot mailing list at 63<u-boot@lists.denx.de>. There is also an archive of previous traffic 64on the mailing list - please search the archive before asking FAQ's. 65Please see http://lists.denx.de/pipermail/u-boot and 66http://dir.gmane.org/gmane.comp.boot-loaders.u-boot 67 68 69Where to get source code: 70========================= 71 72The U-Boot source code is maintained in the git repository at 73git://www.denx.de/git/u-boot.git ; you can browse it online at 74http://www.denx.de/cgi-bin/gitweb.cgi?p=u-boot.git;a=summary 75 76The "snapshot" links on this page allow you to download tarballs of 77any version you might be interested in. Official releases are also 78available for FTP download from the ftp://ftp.denx.de/pub/u-boot/ 79directory. 80 81Pre-built (and tested) images are available from 82ftp://ftp.denx.de/pub/u-boot/images/ 83 84 85Where we come from: 86=================== 87 88- start from 8xxrom sources 89- create PPCBoot project (http://sourceforge.net/projects/ppcboot) 90- clean up code 91- make it easier to add custom boards 92- make it possible to add other [PowerPC] CPUs 93- extend functions, especially: 94 * Provide extended interface to Linux boot loader 95 * S-Record download 96 * network boot 97 * PCMCIA / CompactFlash / ATA disk / SCSI ... boot 98- create ARMBoot project (http://sourceforge.net/projects/armboot) 99- add other CPU families (starting with ARM) 100- create U-Boot project (http://sourceforge.net/projects/u-boot) 101- current project page: see http://www.denx.de/wiki/U-Boot 102 103 104Names and Spelling: 105=================== 106 107The "official" name of this project is "Das U-Boot". The spelling 108"U-Boot" shall be used in all written text (documentation, comments 109in source files etc.). Example: 110 111 This is the README file for the U-Boot project. 112 113File names etc. shall be based on the string "u-boot". Examples: 114 115 include/asm-ppc/u-boot.h 116 117 #include <asm/u-boot.h> 118 119Variable names, preprocessor constants etc. shall be either based on 120the string "u_boot" or on "U_BOOT". Example: 121 122 U_BOOT_VERSION u_boot_logo 123 IH_OS_U_BOOT u_boot_hush_start 124 125 126Versioning: 127=========== 128 129Starting with the release in October 2008, the names of the releases 130were changed from numerical release numbers without deeper meaning 131into a time stamp based numbering. Regular releases are identified by 132names consisting of the calendar year and month of the release date. 133Additional fields (if present) indicate release candidates or bug fix 134releases in "stable" maintenance trees. 135 136Examples: 137 U-Boot v2009.11 - Release November 2009 138 U-Boot v2009.11.1 - Release 1 in version November 2009 stable tree 139 U-Boot v2010.09-rc1 - Release candiate 1 for September 2010 release 140 141 142Directory Hierarchy: 143==================== 144 145/arch Architecture specific files 146 /arm Files generic to ARM architecture 147 /cpu CPU specific files 148 /arm720t Files specific to ARM 720 CPUs 149 /arm920t Files specific to ARM 920 CPUs 150 /at91rm9200 Files specific to Atmel AT91RM9200 CPU 151 /imx Files specific to Freescale MC9328 i.MX CPUs 152 /s3c24x0 Files specific to Samsung S3C24X0 CPUs 153 /arm925t Files specific to ARM 925 CPUs 154 /arm926ejs Files specific to ARM 926 CPUs 155 /arm1136 Files specific to ARM 1136 CPUs 156 /ixp Files specific to Intel XScale IXP CPUs 157 /pxa Files specific to Intel XScale PXA CPUs 158 /s3c44b0 Files specific to Samsung S3C44B0 CPUs 159 /sa1100 Files specific to Intel StrongARM SA1100 CPUs 160 /lib Architecture specific library files 161 /avr32 Files generic to AVR32 architecture 162 /cpu CPU specific files 163 /lib Architecture specific library files 164 /blackfin Files generic to Analog Devices Blackfin architecture 165 /cpu CPU specific files 166 /lib Architecture specific library files 167 /i386 Files generic to i386 architecture 168 /cpu CPU specific files 169 /lib Architecture specific library files 170 /m68k Files generic to m68k architecture 171 /cpu CPU specific files 172 /mcf52x2 Files specific to Freescale ColdFire MCF52x2 CPUs 173 /mcf5227x Files specific to Freescale ColdFire MCF5227x CPUs 174 /mcf532x Files specific to Freescale ColdFire MCF5329 CPUs 175 /mcf5445x Files specific to Freescale ColdFire MCF5445x CPUs 176 /mcf547x_8x Files specific to Freescale ColdFire MCF547x_8x CPUs 177 /lib Architecture specific library files 178 /microblaze Files generic to microblaze architecture 179 /cpu CPU specific files 180 /lib Architecture specific library files 181 /mips Files generic to MIPS architecture 182 /cpu CPU specific files 183 /lib Architecture specific library files 184 /nios2 Files generic to Altera NIOS2 architecture 185 /cpu CPU specific files 186 /lib Architecture specific library files 187 /powerpc Files generic to PowerPC architecture 188 /cpu CPU specific files 189 /74xx_7xx Files specific to Freescale MPC74xx and 7xx CPUs 190 /mpc5xx Files specific to Freescale MPC5xx CPUs 191 /mpc5xxx Files specific to Freescale MPC5xxx CPUs 192 /mpc8xx Files specific to Freescale MPC8xx CPUs 193 /mpc8220 Files specific to Freescale MPC8220 CPUs 194 /mpc824x Files specific to Freescale MPC824x CPUs 195 /mpc8260 Files specific to Freescale MPC8260 CPUs 196 /mpc85xx Files specific to Freescale MPC85xx CPUs 197 /ppc4xx Files specific to AMCC PowerPC 4xx CPUs 198 /lib Architecture specific library files 199 /sh Files generic to SH architecture 200 /cpu CPU specific files 201 /sh2 Files specific to sh2 CPUs 202 /sh3 Files specific to sh3 CPUs 203 /sh4 Files specific to sh4 CPUs 204 /lib Architecture specific library files 205 /sparc Files generic to SPARC architecture 206 /cpu CPU specific files 207 /leon2 Files specific to Gaisler LEON2 SPARC CPU 208 /leon3 Files specific to Gaisler LEON3 SPARC CPU 209 /lib Architecture specific library files 210/api Machine/arch independent API for external apps 211/board Board dependent files 212/common Misc architecture independent functions 213/disk Code for disk drive partition handling 214/doc Documentation (don't expect too much) 215/drivers Commonly used device drivers 216/examples Example code for standalone applications, etc. 217/fs Filesystem code (cramfs, ext2, jffs2, etc.) 218/include Header Files 219/lib Files generic to all architectures 220 /libfdt Library files to support flattened device trees 221 /lzma Library files to support LZMA decompression 222 /lzo Library files to support LZO decompression 223/net Networking code 224/post Power On Self Test 225/rtc Real Time Clock drivers 226/tools Tools to build S-Record or U-Boot images, etc. 227 228Software Configuration: 229======================= 230 231Configuration is usually done using C preprocessor defines; the 232rationale behind that is to avoid dead code whenever possible. 233 234There are two classes of configuration variables: 235 236* Configuration _OPTIONS_: 237 These are selectable by the user and have names beginning with 238 "CONFIG_". 239 240* Configuration _SETTINGS_: 241 These depend on the hardware etc. and should not be meddled with if 242 you don't know what you're doing; they have names beginning with 243 "CONFIG_SYS_". 244 245Later we will add a configuration tool - probably similar to or even 246identical to what's used for the Linux kernel. Right now, we have to 247do the configuration by hand, which means creating some symbolic 248links and editing some configuration files. We use the TQM8xxL boards 249as an example here. 250 251 252Selection of Processor Architecture and Board Type: 253--------------------------------------------------- 254 255For all supported boards there are ready-to-use default 256configurations available; just type "make <board_name>_config". 257 258Example: For a TQM823L module type: 259 260 cd u-boot 261 make TQM823L_config 262 263For the Cogent platform, you need to specify the CPU type as well; 264e.g. "make cogent_mpc8xx_config". And also configure the cogent 265directory according to the instructions in cogent/README. 266 267 268Configuration Options: 269---------------------- 270 271Configuration depends on the combination of board and CPU type; all 272such information is kept in a configuration file 273"include/configs/<board_name>.h". 274 275Example: For a TQM823L module, all configuration settings are in 276"include/configs/TQM823L.h". 277 278 279Many of the options are named exactly as the corresponding Linux 280kernel configuration options. The intention is to make it easier to 281build a config tool - later. 282 283 284The following options need to be configured: 285 286- CPU Type: Define exactly one, e.g. CONFIG_MPC85XX. 287 288- Board Type: Define exactly one, e.g. CONFIG_MPC8540ADS. 289 290- CPU Daughterboard Type: (if CONFIG_ATSTK1000 is defined) 291 Define exactly one, e.g. CONFIG_ATSTK1002 292 293- CPU Module Type: (if CONFIG_COGENT is defined) 294 Define exactly one of 295 CONFIG_CMA286_60_OLD 296--- FIXME --- not tested yet: 297 CONFIG_CMA286_60, CONFIG_CMA286_21, CONFIG_CMA286_60P, 298 CONFIG_CMA287_23, CONFIG_CMA287_50 299 300- Motherboard Type: (if CONFIG_COGENT is defined) 301 Define exactly one of 302 CONFIG_CMA101, CONFIG_CMA102 303 304- Motherboard I/O Modules: (if CONFIG_COGENT is defined) 305 Define one or more of 306 CONFIG_CMA302 307 308- Motherboard Options: (if CONFIG_CMA101 or CONFIG_CMA102 are defined) 309 Define one or more of 310 CONFIG_LCD_HEARTBEAT - update a character position on 311 the LCD display every second with 312 a "rotator" |\-/|\-/ 313 314- Board flavour: (if CONFIG_MPC8260ADS is defined) 315 CONFIG_ADSTYPE 316 Possible values are: 317 CONFIG_SYS_8260ADS - original MPC8260ADS 318 CONFIG_SYS_8266ADS - MPC8266ADS 319 CONFIG_SYS_PQ2FADS - PQ2FADS-ZU or PQ2FADS-VR 320 CONFIG_SYS_8272ADS - MPC8272ADS 321 322- MPC824X Family Member (if CONFIG_MPC824X is defined) 323 Define exactly one of 324 CONFIG_MPC8240, CONFIG_MPC8245 325 326- 8xx CPU Options: (if using an MPC8xx CPU) 327 CONFIG_8xx_GCLK_FREQ - deprecated: CPU clock if 328 get_gclk_freq() cannot work 329 e.g. if there is no 32KHz 330 reference PIT/RTC clock 331 CONFIG_8xx_OSCLK - PLL input clock (either EXTCLK 332 or XTAL/EXTAL) 333 334- 859/866/885 CPU options: (if using a MPC859 or MPC866 or MPC885 CPU): 335 CONFIG_SYS_8xx_CPUCLK_MIN 336 CONFIG_SYS_8xx_CPUCLK_MAX 337 CONFIG_8xx_CPUCLK_DEFAULT 338 See doc/README.MPC866 339 340 CONFIG_SYS_MEASURE_CPUCLK 341 342 Define this to measure the actual CPU clock instead 343 of relying on the correctness of the configured 344 values. Mostly useful for board bringup to make sure 345 the PLL is locked at the intended frequency. Note 346 that this requires a (stable) reference clock (32 kHz 347 RTC clock or CONFIG_SYS_8XX_XIN) 348 349 CONFIG_SYS_DELAYED_ICACHE 350 351 Define this option if you want to enable the 352 ICache only when Code runs from RAM. 353 354- Intel Monahans options: 355 CONFIG_SYS_MONAHANS_RUN_MODE_OSC_RATIO 356 357 Defines the Monahans run mode to oscillator 358 ratio. Valid values are 8, 16, 24, 31. The core 359 frequency is this value multiplied by 13 MHz. 360 361 CONFIG_SYS_MONAHANS_TURBO_RUN_MODE_RATIO 362 363 Defines the Monahans turbo mode to oscillator 364 ratio. Valid values are 1 (default if undefined) and 365 2. The core frequency as calculated above is multiplied 366 by this value. 367 368- Linux Kernel Interface: 369 CONFIG_CLOCKS_IN_MHZ 370 371 U-Boot stores all clock information in Hz 372 internally. For binary compatibility with older Linux 373 kernels (which expect the clocks passed in the 374 bd_info data to be in MHz) the environment variable 375 "clocks_in_mhz" can be defined so that U-Boot 376 converts clock data to MHZ before passing it to the 377 Linux kernel. 378 When CONFIG_CLOCKS_IN_MHZ is defined, a definition of 379 "clocks_in_mhz=1" is automatically included in the 380 default environment. 381 382 CONFIG_MEMSIZE_IN_BYTES [relevant for MIPS only] 383 384 When transferring memsize parameter to linux, some versions 385 expect it to be in bytes, others in MB. 386 Define CONFIG_MEMSIZE_IN_BYTES to make it in bytes. 387 388 CONFIG_OF_LIBFDT 389 390 New kernel versions are expecting firmware settings to be 391 passed using flattened device trees (based on open firmware 392 concepts). 393 394 CONFIG_OF_LIBFDT 395 * New libfdt-based support 396 * Adds the "fdt" command 397 * The bootm command automatically updates the fdt 398 399 OF_CPU - The proper name of the cpus node (only required for 400 MPC512X and MPC5xxx based boards). 401 OF_SOC - The proper name of the soc node (only required for 402 MPC512X and MPC5xxx based boards). 403 OF_TBCLK - The timebase frequency. 404 OF_STDOUT_PATH - The path to the console device 405 406 boards with QUICC Engines require OF_QE to set UCC MAC 407 addresses 408 409 CONFIG_OF_BOARD_SETUP 410 411 Board code has addition modification that it wants to make 412 to the flat device tree before handing it off to the kernel 413 414 CONFIG_OF_BOOT_CPU 415 416 This define fills in the correct boot CPU in the boot 417 param header, the default value is zero if undefined. 418 419 CONFIG_OF_IDE_FIXUP 420 421 U-Boot can detect if an IDE device is present or not. 422 If not, and this new config option is activated, U-Boot 423 removes the ATA node from the DTS before booting Linux, 424 so the Linux IDE driver does not probe the device and 425 crash. This is needed for buggy hardware (uc101) where 426 no pull down resistor is connected to the signal IDE5V_DD7. 427 428- vxWorks boot parameters: 429 430 bootvx constructs a valid bootline using the following 431 environments variables: bootfile, ipaddr, serverip, hostname. 432 It loads the vxWorks image pointed bootfile. 433 434 CONFIG_SYS_VXWORKS_BOOT_DEVICE - The vxworks device name 435 CONFIG_SYS_VXWORKS_MAC_PTR - Ethernet 6 byte MA -address 436 CONFIG_SYS_VXWORKS_SERVERNAME - Name of the server 437 CONFIG_SYS_VXWORKS_BOOT_ADDR - Address of boot parameters 438 439 CONFIG_SYS_VXWORKS_ADD_PARAMS 440 441 Add it at the end of the bootline. E.g "u=username pw=secret" 442 443 Note: If a "bootargs" environment is defined, it will overwride 444 the defaults discussed just above. 445 446- Serial Ports: 447 CONFIG_PL010_SERIAL 448 449 Define this if you want support for Amba PrimeCell PL010 UARTs. 450 451 CONFIG_PL011_SERIAL 452 453 Define this if you want support for Amba PrimeCell PL011 UARTs. 454 455 CONFIG_PL011_CLOCK 456 457 If you have Amba PrimeCell PL011 UARTs, set this variable to 458 the clock speed of the UARTs. 459 460 CONFIG_PL01x_PORTS 461 462 If you have Amba PrimeCell PL010 or PL011 UARTs on your board, 463 define this to a list of base addresses for each (supported) 464 port. See e.g. include/configs/versatile.h 465 466 467- Console Interface: 468 Depending on board, define exactly one serial port 469 (like CONFIG_8xx_CONS_SMC1, CONFIG_8xx_CONS_SMC2, 470 CONFIG_8xx_CONS_SCC1, ...), or switch off the serial 471 console by defining CONFIG_8xx_CONS_NONE 472 473 Note: if CONFIG_8xx_CONS_NONE is defined, the serial 474 port routines must be defined elsewhere 475 (i.e. serial_init(), serial_getc(), ...) 476 477 CONFIG_CFB_CONSOLE 478 Enables console device for a color framebuffer. Needs following 479 defines (cf. smiLynxEM, i8042, board/eltec/bab7xx) 480 VIDEO_FB_LITTLE_ENDIAN graphic memory organisation 481 (default big endian) 482 VIDEO_HW_RECTFILL graphic chip supports 483 rectangle fill 484 (cf. smiLynxEM) 485 VIDEO_HW_BITBLT graphic chip supports 486 bit-blit (cf. smiLynxEM) 487 VIDEO_VISIBLE_COLS visible pixel columns 488 (cols=pitch) 489 VIDEO_VISIBLE_ROWS visible pixel rows 490 VIDEO_PIXEL_SIZE bytes per pixel 491 VIDEO_DATA_FORMAT graphic data format 492 (0-5, cf. cfb_console.c) 493 VIDEO_FB_ADRS framebuffer address 494 VIDEO_KBD_INIT_FCT keyboard int fct 495 (i.e. i8042_kbd_init()) 496 VIDEO_TSTC_FCT test char fct 497 (i.e. i8042_tstc) 498 VIDEO_GETC_FCT get char fct 499 (i.e. i8042_getc) 500 CONFIG_CONSOLE_CURSOR cursor drawing on/off 501 (requires blink timer 502 cf. i8042.c) 503 CONFIG_SYS_CONSOLE_BLINK_COUNT blink interval (cf. i8042.c) 504 CONFIG_CONSOLE_TIME display time/date info in 505 upper right corner 506 (requires CONFIG_CMD_DATE) 507 CONFIG_VIDEO_LOGO display Linux logo in 508 upper left corner 509 CONFIG_VIDEO_BMP_LOGO use bmp_logo.h instead of 510 linux_logo.h for logo. 511 Requires CONFIG_VIDEO_LOGO 512 CONFIG_CONSOLE_EXTRA_INFO 513 additional board info beside 514 the logo 515 516 When CONFIG_CFB_CONSOLE is defined, video console is 517 default i/o. Serial console can be forced with 518 environment 'console=serial'. 519 520 When CONFIG_SILENT_CONSOLE is defined, all console 521 messages (by U-Boot and Linux!) can be silenced with 522 the "silent" environment variable. See 523 doc/README.silent for more information. 524 525- Console Baudrate: 526 CONFIG_BAUDRATE - in bps 527 Select one of the baudrates listed in 528 CONFIG_SYS_BAUDRATE_TABLE, see below. 529 CONFIG_SYS_BRGCLK_PRESCALE, baudrate prescale 530 531- Console Rx buffer length 532 With CONFIG_SYS_SMC_RXBUFLEN it is possible to define 533 the maximum receive buffer length for the SMC. 534 This option is actual only for 82xx and 8xx possible. 535 If using CONFIG_SYS_SMC_RXBUFLEN also CONFIG_SYS_MAXIDLE 536 must be defined, to setup the maximum idle timeout for 537 the SMC. 538 539- Boot Delay: CONFIG_BOOTDELAY - in seconds 540 Delay before automatically booting the default image; 541 set to -1 to disable autoboot. 542 543 See doc/README.autoboot for these options that 544 work with CONFIG_BOOTDELAY. None are required. 545 CONFIG_BOOT_RETRY_TIME 546 CONFIG_BOOT_RETRY_MIN 547 CONFIG_AUTOBOOT_KEYED 548 CONFIG_AUTOBOOT_PROMPT 549 CONFIG_AUTOBOOT_DELAY_STR 550 CONFIG_AUTOBOOT_STOP_STR 551 CONFIG_AUTOBOOT_DELAY_STR2 552 CONFIG_AUTOBOOT_STOP_STR2 553 CONFIG_ZERO_BOOTDELAY_CHECK 554 CONFIG_RESET_TO_RETRY 555 556- Autoboot Command: 557 CONFIG_BOOTCOMMAND 558 Only needed when CONFIG_BOOTDELAY is enabled; 559 define a command string that is automatically executed 560 when no character is read on the console interface 561 within "Boot Delay" after reset. 562 563 CONFIG_BOOTARGS 564 This can be used to pass arguments to the bootm 565 command. The value of CONFIG_BOOTARGS goes into the 566 environment value "bootargs". 567 568 CONFIG_RAMBOOT and CONFIG_NFSBOOT 569 The value of these goes into the environment as 570 "ramboot" and "nfsboot" respectively, and can be used 571 as a convenience, when switching between booting from 572 RAM and NFS. 573 574- Pre-Boot Commands: 575 CONFIG_PREBOOT 576 577 When this option is #defined, the existence of the 578 environment variable "preboot" will be checked 579 immediately before starting the CONFIG_BOOTDELAY 580 countdown and/or running the auto-boot command resp. 581 entering interactive mode. 582 583 This feature is especially useful when "preboot" is 584 automatically generated or modified. For an example 585 see the LWMON board specific code: here "preboot" is 586 modified when the user holds down a certain 587 combination of keys on the (special) keyboard when 588 booting the systems 589 590- Serial Download Echo Mode: 591 CONFIG_LOADS_ECHO 592 If defined to 1, all characters received during a 593 serial download (using the "loads" command) are 594 echoed back. This might be needed by some terminal 595 emulations (like "cu"), but may as well just take 596 time on others. This setting #define's the initial 597 value of the "loads_echo" environment variable. 598 599- Kgdb Serial Baudrate: (if CONFIG_CMD_KGDB is defined) 600 CONFIG_KGDB_BAUDRATE 601 Select one of the baudrates listed in 602 CONFIG_SYS_BAUDRATE_TABLE, see below. 603 604- Monitor Functions: 605 Monitor commands can be included or excluded 606 from the build by using the #include files 607 "config_cmd_all.h" and #undef'ing unwanted 608 commands, or using "config_cmd_default.h" 609 and augmenting with additional #define's 610 for wanted commands. 611 612 The default command configuration includes all commands 613 except those marked below with a "*". 614 615 CONFIG_CMD_ASKENV * ask for env variable 616 CONFIG_CMD_BDI bdinfo 617 CONFIG_CMD_BEDBUG * Include BedBug Debugger 618 CONFIG_CMD_BMP * BMP support 619 CONFIG_CMD_BSP * Board specific commands 620 CONFIG_CMD_BOOTD bootd 621 CONFIG_CMD_CACHE * icache, dcache 622 CONFIG_CMD_CONSOLE coninfo 623 CONFIG_CMD_DATE * support for RTC, date/time... 624 CONFIG_CMD_DHCP * DHCP support 625 CONFIG_CMD_DIAG * Diagnostics 626 CONFIG_CMD_DS4510 * ds4510 I2C gpio commands 627 CONFIG_CMD_DS4510_INFO * ds4510 I2C info command 628 CONFIG_CMD_DS4510_MEM * ds4510 I2C eeprom/sram commansd 629 CONFIG_CMD_DS4510_RST * ds4510 I2C rst command 630 CONFIG_CMD_DTT * Digital Therm and Thermostat 631 CONFIG_CMD_ECHO echo arguments 632 CONFIG_CMD_EDITENV edit env variable 633 CONFIG_CMD_EEPROM * EEPROM read/write support 634 CONFIG_CMD_ELF * bootelf, bootvx 635 CONFIG_CMD_SAVEENV saveenv 636 CONFIG_CMD_FDC * Floppy Disk Support 637 CONFIG_CMD_FAT * FAT partition support 638 CONFIG_CMD_FDOS * Dos diskette Support 639 CONFIG_CMD_FLASH flinfo, erase, protect 640 CONFIG_CMD_FPGA FPGA device initialization support 641 CONFIG_CMD_HWFLOW * RTS/CTS hw flow control 642 CONFIG_CMD_I2C * I2C serial bus support 643 CONFIG_CMD_IDE * IDE harddisk support 644 CONFIG_CMD_IMI iminfo 645 CONFIG_CMD_IMLS List all found images 646 CONFIG_CMD_IMMAP * IMMR dump support 647 CONFIG_CMD_IRQ * irqinfo 648 CONFIG_CMD_ITEST Integer/string test of 2 values 649 CONFIG_CMD_JFFS2 * JFFS2 Support 650 CONFIG_CMD_KGDB * kgdb 651 CONFIG_CMD_LOADB loadb 652 CONFIG_CMD_LOADS loads 653 CONFIG_CMD_MD5SUM print md5 message digest 654 (requires CONFIG_CMD_MEMORY and CONFIG_MD5) 655 CONFIG_CMD_MEMORY md, mm, nm, mw, cp, cmp, crc, base, 656 loop, loopw, mtest 657 CONFIG_CMD_MISC Misc functions like sleep etc 658 CONFIG_CMD_MMC * MMC memory mapped support 659 CONFIG_CMD_MII * MII utility commands 660 CONFIG_CMD_MTDPARTS * MTD partition support 661 CONFIG_CMD_NAND * NAND support 662 CONFIG_CMD_NET bootp, tftpboot, rarpboot 663 CONFIG_CMD_PCA953X * PCA953x I2C gpio commands 664 CONFIG_CMD_PCA953X_INFO * PCA953x I2C gpio info command 665 CONFIG_CMD_PCI * pciinfo 666 CONFIG_CMD_PCMCIA * PCMCIA support 667 CONFIG_CMD_PING * send ICMP ECHO_REQUEST to network 668 host 669 CONFIG_CMD_PORTIO * Port I/O 670 CONFIG_CMD_REGINFO * Register dump 671 CONFIG_CMD_RUN run command in env variable 672 CONFIG_CMD_SAVES * save S record dump 673 CONFIG_CMD_SCSI * SCSI Support 674 CONFIG_CMD_SDRAM * print SDRAM configuration information 675 (requires CONFIG_CMD_I2C) 676 CONFIG_CMD_SETGETDCR Support for DCR Register access 677 (4xx only) 678 CONFIG_CMD_SHA1 print sha1 memory digest 679 (requires CONFIG_CMD_MEMORY) 680 CONFIG_CMD_SOURCE "source" command Support 681 CONFIG_CMD_SPI * SPI serial bus support 682 CONFIG_CMD_USB * USB support 683 CONFIG_CMD_VFD * VFD support (TRAB) 684 CONFIG_CMD_CDP * Cisco Discover Protocol support 685 CONFIG_CMD_FSL * Microblaze FSL support 686 687 688 EXAMPLE: If you want all functions except of network 689 support you can write: 690 691 #include "config_cmd_all.h" 692 #undef CONFIG_CMD_NET 693 694 Other Commands: 695 fdt (flattened device tree) command: CONFIG_OF_LIBFDT 696 697 Note: Don't enable the "icache" and "dcache" commands 698 (configuration option CONFIG_CMD_CACHE) unless you know 699 what you (and your U-Boot users) are doing. Data 700 cache cannot be enabled on systems like the 8xx or 701 8260 (where accesses to the IMMR region must be 702 uncached), and it cannot be disabled on all other 703 systems where we (mis-) use the data cache to hold an 704 initial stack and some data. 705 706 707 XXX - this list needs to get updated! 708 709- Watchdog: 710 CONFIG_WATCHDOG 711 If this variable is defined, it enables watchdog 712 support. There must be support in the platform specific 713 code for a watchdog. For the 8xx and 8260 CPUs, the 714 SIU Watchdog feature is enabled in the SYPCR 715 register. 716 717- U-Boot Version: 718 CONFIG_VERSION_VARIABLE 719 If this variable is defined, an environment variable 720 named "ver" is created by U-Boot showing the U-Boot 721 version as printed by the "version" command. 722 This variable is readonly. 723 724- Real-Time Clock: 725 726 When CONFIG_CMD_DATE is selected, the type of the RTC 727 has to be selected, too. Define exactly one of the 728 following options: 729 730 CONFIG_RTC_MPC8xx - use internal RTC of MPC8xx 731 CONFIG_RTC_PCF8563 - use Philips PCF8563 RTC 732 CONFIG_RTC_MC13783 - use MC13783 RTC 733 CONFIG_RTC_MC146818 - use MC146818 RTC 734 CONFIG_RTC_DS1307 - use Maxim, Inc. DS1307 RTC 735 CONFIG_RTC_DS1337 - use Maxim, Inc. DS1337 RTC 736 CONFIG_RTC_DS1338 - use Maxim, Inc. DS1338 RTC 737 CONFIG_RTC_DS164x - use Dallas DS164x RTC 738 CONFIG_RTC_ISL1208 - use Intersil ISL1208 RTC 739 CONFIG_RTC_MAX6900 - use Maxim, Inc. MAX6900 RTC 740 CONFIG_SYS_RTC_DS1337_NOOSC - Turn off the OSC output for DS1337 741 742 Note that if the RTC uses I2C, then the I2C interface 743 must also be configured. See I2C Support, below. 744 745- GPIO Support: 746 CONFIG_PCA953X - use NXP's PCA953X series I2C GPIO 747 CONFIG_PCA953X_INFO - enable pca953x info command 748 749 Note that if the GPIO device uses I2C, then the I2C interface 750 must also be configured. See I2C Support, below. 751 752- Timestamp Support: 753 754 When CONFIG_TIMESTAMP is selected, the timestamp 755 (date and time) of an image is printed by image 756 commands like bootm or iminfo. This option is 757 automatically enabled when you select CONFIG_CMD_DATE . 758 759- Partition Support: 760 CONFIG_MAC_PARTITION and/or CONFIG_DOS_PARTITION 761 and/or CONFIG_ISO_PARTITION and/or CONFIG_EFI_PARTITION 762 763 If IDE or SCSI support is enabled (CONFIG_CMD_IDE or 764 CONFIG_CMD_SCSI) you must configure support for at 765 least one partition type as well. 766 767- IDE Reset method: 768 CONFIG_IDE_RESET_ROUTINE - this is defined in several 769 board configurations files but used nowhere! 770 771 CONFIG_IDE_RESET - is this is defined, IDE Reset will 772 be performed by calling the function 773 ide_set_reset(int reset) 774 which has to be defined in a board specific file 775 776- ATAPI Support: 777 CONFIG_ATAPI 778 779 Set this to enable ATAPI support. 780 781- LBA48 Support 782 CONFIG_LBA48 783 784 Set this to enable support for disks larger than 137GB 785 Also look at CONFIG_SYS_64BIT_LBA. 786 Whithout these , LBA48 support uses 32bit variables and will 'only' 787 support disks up to 2.1TB. 788 789 CONFIG_SYS_64BIT_LBA: 790 When enabled, makes the IDE subsystem use 64bit sector addresses. 791 Default is 32bit. 792 793- SCSI Support: 794 At the moment only there is only support for the 795 SYM53C8XX SCSI controller; define 796 CONFIG_SCSI_SYM53C8XX to enable it. 797 798 CONFIG_SYS_SCSI_MAX_LUN [8], CONFIG_SYS_SCSI_MAX_SCSI_ID [7] and 799 CONFIG_SYS_SCSI_MAX_DEVICE [CONFIG_SYS_SCSI_MAX_SCSI_ID * 800 CONFIG_SYS_SCSI_MAX_LUN] can be adjusted to define the 801 maximum numbers of LUNs, SCSI ID's and target 802 devices. 803 CONFIG_SYS_SCSI_SYM53C8XX_CCF to fix clock timing (80Mhz) 804 805- NETWORK Support (PCI): 806 CONFIG_E1000 807 Support for Intel 8254x gigabit chips. 808 809 CONFIG_E1000_FALLBACK_MAC 810 default MAC for empty EEPROM after production. 811 812 CONFIG_EEPRO100 813 Support for Intel 82557/82559/82559ER chips. 814 Optional CONFIG_EEPRO100_SROM_WRITE enables EEPROM 815 write routine for first time initialisation. 816 817 CONFIG_TULIP 818 Support for Digital 2114x chips. 819 Optional CONFIG_TULIP_SELECT_MEDIA for board specific 820 modem chip initialisation (KS8761/QS6611). 821 822 CONFIG_NATSEMI 823 Support for National dp83815 chips. 824 825 CONFIG_NS8382X 826 Support for National dp8382[01] gigabit chips. 827 828- NETWORK Support (other): 829 830 CONFIG_DRIVER_AT91EMAC 831 Support for AT91RM9200 EMAC. 832 833 CONFIG_RMII 834 Define this to use reduced MII inteface 835 836 CONFIG_DRIVER_AT91EMAC_QUIET 837 If this defined, the driver is quiet. 838 The driver doen't show link status messages. 839 840 CONFIG_DRIVER_LAN91C96 841 Support for SMSC's LAN91C96 chips. 842 843 CONFIG_LAN91C96_BASE 844 Define this to hold the physical address 845 of the LAN91C96's I/O space 846 847 CONFIG_LAN91C96_USE_32_BIT 848 Define this to enable 32 bit addressing 849 850 CONFIG_DRIVER_SMC91111 851 Support for SMSC's LAN91C111 chip 852 853 CONFIG_SMC91111_BASE 854 Define this to hold the physical address 855 of the device (I/O space) 856 857 CONFIG_SMC_USE_32_BIT 858 Define this if data bus is 32 bits 859 860 CONFIG_SMC_USE_IOFUNCS 861 Define this to use i/o functions instead of macros 862 (some hardware wont work with macros) 863 864 CONFIG_SMC911X 865 Support for SMSC's LAN911x and LAN921x chips 866 867 CONFIG_SMC911X_BASE 868 Define this to hold the physical address 869 of the device (I/O space) 870 871 CONFIG_SMC911X_32_BIT 872 Define this if data bus is 32 bits 873 874 CONFIG_SMC911X_16_BIT 875 Define this if data bus is 16 bits. If your processor 876 automatically converts one 32 bit word to two 16 bit 877 words you may also try CONFIG_SMC911X_32_BIT. 878 879- USB Support: 880 At the moment only the UHCI host controller is 881 supported (PIP405, MIP405, MPC5200); define 882 CONFIG_USB_UHCI to enable it. 883 define CONFIG_USB_KEYBOARD to enable the USB Keyboard 884 and define CONFIG_USB_STORAGE to enable the USB 885 storage devices. 886 Note: 887 Supported are USB Keyboards and USB Floppy drives 888 (TEAC FD-05PUB). 889 MPC5200 USB requires additional defines: 890 CONFIG_USB_CLOCK 891 for 528 MHz Clock: 0x0001bbbb 892 CONFIG_PSC3_USB 893 for USB on PSC3 894 CONFIG_USB_CONFIG 895 for differential drivers: 0x00001000 896 for single ended drivers: 0x00005000 897 for differential drivers on PSC3: 0x00000100 898 for single ended drivers on PSC3: 0x00004100 899 CONFIG_SYS_USB_EVENT_POLL 900 May be defined to allow interrupt polling 901 instead of using asynchronous interrupts 902 903- USB Device: 904 Define the below if you wish to use the USB console. 905 Once firmware is rebuilt from a serial console issue the 906 command "setenv stdin usbtty; setenv stdout usbtty" and 907 attach your USB cable. The Unix command "dmesg" should print 908 it has found a new device. The environment variable usbtty 909 can be set to gserial or cdc_acm to enable your device to 910 appear to a USB host as a Linux gserial device or a 911 Common Device Class Abstract Control Model serial device. 912 If you select usbtty = gserial you should be able to enumerate 913 a Linux host by 914 # modprobe usbserial vendor=0xVendorID product=0xProductID 915 else if using cdc_acm, simply setting the environment 916 variable usbtty to be cdc_acm should suffice. The following 917 might be defined in YourBoardName.h 918 919 CONFIG_USB_DEVICE 920 Define this to build a UDC device 921 922 CONFIG_USB_TTY 923 Define this to have a tty type of device available to 924 talk to the UDC device 925 926 CONFIG_SYS_CONSOLE_IS_IN_ENV 927 Define this if you want stdin, stdout &/or stderr to 928 be set to usbtty. 929 930 mpc8xx: 931 CONFIG_SYS_USB_EXTC_CLK 0xBLAH 932 Derive USB clock from external clock "blah" 933 - CONFIG_SYS_USB_EXTC_CLK 0x02 934 935 CONFIG_SYS_USB_BRG_CLK 0xBLAH 936 Derive USB clock from brgclk 937 - CONFIG_SYS_USB_BRG_CLK 0x04 938 939 If you have a USB-IF assigned VendorID then you may wish to 940 define your own vendor specific values either in BoardName.h 941 or directly in usbd_vendor_info.h. If you don't define 942 CONFIG_USBD_MANUFACTURER, CONFIG_USBD_PRODUCT_NAME, 943 CONFIG_USBD_VENDORID and CONFIG_USBD_PRODUCTID, then U-Boot 944 should pretend to be a Linux device to it's target host. 945 946 CONFIG_USBD_MANUFACTURER 947 Define this string as the name of your company for 948 - CONFIG_USBD_MANUFACTURER "my company" 949 950 CONFIG_USBD_PRODUCT_NAME 951 Define this string as the name of your product 952 - CONFIG_USBD_PRODUCT_NAME "acme usb device" 953 954 CONFIG_USBD_VENDORID 955 Define this as your assigned Vendor ID from the USB 956 Implementors Forum. This *must* be a genuine Vendor ID 957 to avoid polluting the USB namespace. 958 - CONFIG_USBD_VENDORID 0xFFFF 959 960 CONFIG_USBD_PRODUCTID 961 Define this as the unique Product ID 962 for your device 963 - CONFIG_USBD_PRODUCTID 0xFFFF 964 965 966- MMC Support: 967 The MMC controller on the Intel PXA is supported. To 968 enable this define CONFIG_MMC. The MMC can be 969 accessed from the boot prompt by mapping the device 970 to physical memory similar to flash. Command line is 971 enabled with CONFIG_CMD_MMC. The MMC driver also works with 972 the FAT fs. This is enabled with CONFIG_CMD_FAT. 973 974- Journaling Flash filesystem support: 975 CONFIG_JFFS2_NAND, CONFIG_JFFS2_NAND_OFF, CONFIG_JFFS2_NAND_SIZE, 976 CONFIG_JFFS2_NAND_DEV 977 Define these for a default partition on a NAND device 978 979 CONFIG_SYS_JFFS2_FIRST_SECTOR, 980 CONFIG_SYS_JFFS2_FIRST_BANK, CONFIG_SYS_JFFS2_NUM_BANKS 981 Define these for a default partition on a NOR device 982 983 CONFIG_SYS_JFFS_CUSTOM_PART 984 Define this to create an own partition. You have to provide a 985 function struct part_info* jffs2_part_info(int part_num) 986 987 If you define only one JFFS2 partition you may also want to 988 #define CONFIG_SYS_JFFS_SINGLE_PART 1 989 to disable the command chpart. This is the default when you 990 have not defined a custom partition 991 992- Keyboard Support: 993 CONFIG_ISA_KEYBOARD 994 995 Define this to enable standard (PC-Style) keyboard 996 support 997 998 CONFIG_I8042_KBD 999 Standard PC keyboard driver with US (is default) and 1000 GERMAN key layout (switch via environment 'keymap=de') support. 1001 Export function i8042_kbd_init, i8042_tstc and i8042_getc 1002 for cfb_console. Supports cursor blinking. 1003 1004- Video support: 1005 CONFIG_VIDEO 1006 1007 Define this to enable video support (for output to 1008 video). 1009 1010 CONFIG_VIDEO_CT69000 1011 1012 Enable Chips & Technologies 69000 Video chip 1013 1014 CONFIG_VIDEO_SMI_LYNXEM 1015 Enable Silicon Motion SMI 712/710/810 Video chip. The 1016 video output is selected via environment 'videoout' 1017 (1 = LCD and 2 = CRT). If videoout is undefined, CRT is 1018 assumed. 1019 1020 For the CT69000 and SMI_LYNXEM drivers, videomode is 1021 selected via environment 'videomode'. Two different ways 1022 are possible: 1023 - "videomode=num" 'num' is a standard LiLo mode numbers. 1024 Following standard modes are supported (* is default): 1025 1026 Colors 640x480 800x600 1024x768 1152x864 1280x1024 1027 -------------+--------------------------------------------- 1028 8 bits | 0x301* 0x303 0x305 0x161 0x307 1029 15 bits | 0x310 0x313 0x316 0x162 0x319 1030 16 bits | 0x311 0x314 0x317 0x163 0x31A 1031 24 bits | 0x312 0x315 0x318 ? 0x31B 1032 -------------+--------------------------------------------- 1033 (i.e. setenv videomode 317; saveenv; reset;) 1034 1035 - "videomode=bootargs" all the video parameters are parsed 1036 from the bootargs. (See drivers/video/videomodes.c) 1037 1038 1039 CONFIG_VIDEO_SED13806 1040 Enable Epson SED13806 driver. This driver supports 8bpp 1041 and 16bpp modes defined by CONFIG_VIDEO_SED13806_8BPP 1042 or CONFIG_VIDEO_SED13806_16BPP 1043 1044- Keyboard Support: 1045 CONFIG_KEYBOARD 1046 1047 Define this to enable a custom keyboard support. 1048 This simply calls drv_keyboard_init() which must be 1049 defined in your board-specific files. 1050 The only board using this so far is RBC823. 1051 1052- LCD Support: CONFIG_LCD 1053 1054 Define this to enable LCD support (for output to LCD 1055 display); also select one of the supported displays 1056 by defining one of these: 1057 1058 CONFIG_ATMEL_LCD: 1059 1060 HITACHI TX09D70VM1CCA, 3.5", 240x320. 1061 1062 CONFIG_NEC_NL6448AC33: 1063 1064 NEC NL6448AC33-18. Active, color, single scan. 1065 1066 CONFIG_NEC_NL6448BC20 1067 1068 NEC NL6448BC20-08. 6.5", 640x480. 1069 Active, color, single scan. 1070 1071 CONFIG_NEC_NL6448BC33_54 1072 1073 NEC NL6448BC33-54. 10.4", 640x480. 1074 Active, color, single scan. 1075 1076 CONFIG_SHARP_16x9 1077 1078 Sharp 320x240. Active, color, single scan. 1079 It isn't 16x9, and I am not sure what it is. 1080 1081 CONFIG_SHARP_LQ64D341 1082 1083 Sharp LQ64D341 display, 640x480. 1084 Active, color, single scan. 1085 1086 CONFIG_HLD1045 1087 1088 HLD1045 display, 640x480. 1089 Active, color, single scan. 1090 1091 CONFIG_OPTREX_BW 1092 1093 Optrex CBL50840-2 NF-FW 99 22 M5 1094 or 1095 Hitachi LMG6912RPFC-00T 1096 or 1097 Hitachi SP14Q002 1098 1099 320x240. Black & white. 1100 1101 Normally display is black on white background; define 1102 CONFIG_SYS_WHITE_ON_BLACK to get it inverted. 1103 1104- Splash Screen Support: CONFIG_SPLASH_SCREEN 1105 1106 If this option is set, the environment is checked for 1107 a variable "splashimage". If found, the usual display 1108 of logo, copyright and system information on the LCD 1109 is suppressed and the BMP image at the address 1110 specified in "splashimage" is loaded instead. The 1111 console is redirected to the "nulldev", too. This 1112 allows for a "silent" boot where a splash screen is 1113 loaded very quickly after power-on. 1114 1115 CONFIG_SPLASH_SCREEN_ALIGN 1116 1117 If this option is set the splash image can be freely positioned 1118 on the screen. Environment variable "splashpos" specifies the 1119 position as "x,y". If a positive number is given it is used as 1120 number of pixel from left/top. If a negative number is given it 1121 is used as number of pixel from right/bottom. You can also 1122 specify 'm' for centering the image. 1123 1124 Example: 1125 setenv splashpos m,m 1126 => image at center of screen 1127 1128 setenv splashpos 30,20 1129 => image at x = 30 and y = 20 1130 1131 setenv splashpos -10,m 1132 => vertically centered image 1133 at x = dspWidth - bmpWidth - 9 1134 1135- Gzip compressed BMP image support: CONFIG_VIDEO_BMP_GZIP 1136 1137 If this option is set, additionally to standard BMP 1138 images, gzipped BMP images can be displayed via the 1139 splashscreen support or the bmp command. 1140 1141- Run length encoded BMP image (RLE8) support: CONFIG_VIDEO_BMP_RLE8 1142 1143 If this option is set, 8-bit RLE compressed BMP images 1144 can be displayed via the splashscreen support or the 1145 bmp command. 1146 1147- Compression support: 1148 CONFIG_BZIP2 1149 1150 If this option is set, support for bzip2 compressed 1151 images is included. If not, only uncompressed and gzip 1152 compressed images are supported. 1153 1154 NOTE: the bzip2 algorithm requires a lot of RAM, so 1155 the malloc area (as defined by CONFIG_SYS_MALLOC_LEN) should 1156 be at least 4MB. 1157 1158 CONFIG_LZMA 1159 1160 If this option is set, support for lzma compressed 1161 images is included. 1162 1163 Note: The LZMA algorithm adds between 2 and 4KB of code and it 1164 requires an amount of dynamic memory that is given by the 1165 formula: 1166 1167 (1846 + 768 << (lc + lp)) * sizeof(uint16) 1168 1169 Where lc and lp stand for, respectively, Literal context bits 1170 and Literal pos bits. 1171 1172 This value is upper-bounded by 14MB in the worst case. Anyway, 1173 for a ~4MB large kernel image, we have lc=3 and lp=0 for a 1174 total amount of (1846 + 768 << (3 + 0)) * 2 = ~41KB... that is 1175 a very small buffer. 1176 1177 Use the lzmainfo tool to determinate the lc and lp values and 1178 then calculate the amount of needed dynamic memory (ensuring 1179 the appropriate CONFIG_SYS_MALLOC_LEN value). 1180 1181- MII/PHY support: 1182 CONFIG_PHY_ADDR 1183 1184 The address of PHY on MII bus. 1185 1186 CONFIG_PHY_CLOCK_FREQ (ppc4xx) 1187 1188 The clock frequency of the MII bus 1189 1190 CONFIG_PHY_GIGE 1191 1192 If this option is set, support for speed/duplex 1193 detection of gigabit PHY is included. 1194 1195 CONFIG_PHY_RESET_DELAY 1196 1197 Some PHY like Intel LXT971A need extra delay after 1198 reset before any MII register access is possible. 1199 For such PHY, set this option to the usec delay 1200 required. (minimum 300usec for LXT971A) 1201 1202 CONFIG_PHY_CMD_DELAY (ppc4xx) 1203 1204 Some PHY like Intel LXT971A need extra delay after 1205 command issued before MII status register can be read 1206 1207- Ethernet address: 1208 CONFIG_ETHADDR 1209 CONFIG_ETH1ADDR 1210 CONFIG_ETH2ADDR 1211 CONFIG_ETH3ADDR 1212 CONFIG_ETH4ADDR 1213 CONFIG_ETH5ADDR 1214 1215 Define a default value for Ethernet address to use 1216 for the respective Ethernet interface, in case this 1217 is not determined automatically. 1218 1219- IP address: 1220 CONFIG_IPADDR 1221 1222 Define a default value for the IP address to use for 1223 the default Ethernet interface, in case this is not 1224 determined through e.g. bootp. 1225 1226- Server IP address: 1227 CONFIG_SERVERIP 1228 1229 Defines a default value for the IP address of a TFTP 1230 server to contact when using the "tftboot" command. 1231 1232 CONFIG_KEEP_SERVERADDR 1233 1234 Keeps the server's MAC address, in the env 'serveraddr' 1235 for passing to bootargs (like Linux's netconsole option) 1236 1237- Multicast TFTP Mode: 1238 CONFIG_MCAST_TFTP 1239 1240 Defines whether you want to support multicast TFTP as per 1241 rfc-2090; for example to work with atftp. Lets lots of targets 1242 tftp down the same boot image concurrently. Note: the Ethernet 1243 driver in use must provide a function: mcast() to join/leave a 1244 multicast group. 1245 1246 CONFIG_BOOTP_RANDOM_DELAY 1247- BOOTP Recovery Mode: 1248 CONFIG_BOOTP_RANDOM_DELAY 1249 1250 If you have many targets in a network that try to 1251 boot using BOOTP, you may want to avoid that all 1252 systems send out BOOTP requests at precisely the same 1253 moment (which would happen for instance at recovery 1254 from a power failure, when all systems will try to 1255 boot, thus flooding the BOOTP server. Defining 1256 CONFIG_BOOTP_RANDOM_DELAY causes a random delay to be 1257 inserted before sending out BOOTP requests. The 1258 following delays are inserted then: 1259 1260 1st BOOTP request: delay 0 ... 1 sec 1261 2nd BOOTP request: delay 0 ... 2 sec 1262 3rd BOOTP request: delay 0 ... 4 sec 1263 4th and following 1264 BOOTP requests: delay 0 ... 8 sec 1265 1266- DHCP Advanced Options: 1267 You can fine tune the DHCP functionality by defining 1268 CONFIG_BOOTP_* symbols: 1269 1270 CONFIG_BOOTP_SUBNETMASK 1271 CONFIG_BOOTP_GATEWAY 1272 CONFIG_BOOTP_HOSTNAME 1273 CONFIG_BOOTP_NISDOMAIN 1274 CONFIG_BOOTP_BOOTPATH 1275 CONFIG_BOOTP_BOOTFILESIZE 1276 CONFIG_BOOTP_DNS 1277 CONFIG_BOOTP_DNS2 1278 CONFIG_BOOTP_SEND_HOSTNAME 1279 CONFIG_BOOTP_NTPSERVER 1280 CONFIG_BOOTP_TIMEOFFSET 1281 CONFIG_BOOTP_VENDOREX 1282 1283 CONFIG_BOOTP_SERVERIP - TFTP server will be the serverip 1284 environment variable, not the BOOTP server. 1285 1286 CONFIG_BOOTP_DNS2 - If a DHCP client requests the DNS 1287 serverip from a DHCP server, it is possible that more 1288 than one DNS serverip is offered to the client. 1289 If CONFIG_BOOTP_DNS2 is enabled, the secondary DNS 1290 serverip will be stored in the additional environment 1291 variable "dnsip2". The first DNS serverip is always 1292 stored in the variable "dnsip", when CONFIG_BOOTP_DNS 1293 is defined. 1294 1295 CONFIG_BOOTP_SEND_HOSTNAME - Some DHCP servers are capable 1296 to do a dynamic update of a DNS server. To do this, they 1297 need the hostname of the DHCP requester. 1298 If CONFIG_BOOTP_SEND_HOSTNAME is defined, the content 1299 of the "hostname" environment variable is passed as 1300 option 12 to the DHCP server. 1301 1302 CONFIG_BOOTP_DHCP_REQUEST_DELAY 1303 1304 A 32bit value in microseconds for a delay between 1305 receiving a "DHCP Offer" and sending the "DHCP Request". 1306 This fixes a problem with certain DHCP servers that don't 1307 respond 100% of the time to a "DHCP request". E.g. On an 1308 AT91RM9200 processor running at 180MHz, this delay needed 1309 to be *at least* 15,000 usec before a Windows Server 2003 1310 DHCP server would reply 100% of the time. I recommend at 1311 least 50,000 usec to be safe. The alternative is to hope 1312 that one of the retries will be successful but note that 1313 the DHCP timeout and retry process takes a longer than 1314 this delay. 1315 1316 - CDP Options: 1317 CONFIG_CDP_DEVICE_ID 1318 1319 The device id used in CDP trigger frames. 1320 1321 CONFIG_CDP_DEVICE_ID_PREFIX 1322 1323 A two character string which is prefixed to the MAC address 1324 of the device. 1325 1326 CONFIG_CDP_PORT_ID 1327 1328 A printf format string which contains the ascii name of 1329 the port. Normally is set to "eth%d" which sets 1330 eth0 for the first Ethernet, eth1 for the second etc. 1331 1332 CONFIG_CDP_CAPABILITIES 1333 1334 A 32bit integer which indicates the device capabilities; 1335 0x00000010 for a normal host which does not forwards. 1336 1337 CONFIG_CDP_VERSION 1338 1339 An ascii string containing the version of the software. 1340 1341 CONFIG_CDP_PLATFORM 1342 1343 An ascii string containing the name of the platform. 1344 1345 CONFIG_CDP_TRIGGER 1346 1347 A 32bit integer sent on the trigger. 1348 1349 CONFIG_CDP_POWER_CONSUMPTION 1350 1351 A 16bit integer containing the power consumption of the 1352 device in .1 of milliwatts. 1353 1354 CONFIG_CDP_APPLIANCE_VLAN_TYPE 1355 1356 A byte containing the id of the VLAN. 1357 1358- Status LED: CONFIG_STATUS_LED 1359 1360 Several configurations allow to display the current 1361 status using a LED. For instance, the LED will blink 1362 fast while running U-Boot code, stop blinking as 1363 soon as a reply to a BOOTP request was received, and 1364 start blinking slow once the Linux kernel is running 1365 (supported by a status LED driver in the Linux 1366 kernel). Defining CONFIG_STATUS_LED enables this 1367 feature in U-Boot. 1368 1369- CAN Support: CONFIG_CAN_DRIVER 1370 1371 Defining CONFIG_CAN_DRIVER enables CAN driver support 1372 on those systems that support this (optional) 1373 feature, like the TQM8xxL modules. 1374 1375- I2C Support: CONFIG_HARD_I2C | CONFIG_SOFT_I2C 1376 1377 These enable I2C serial bus commands. Defining either of 1378 (but not both of) CONFIG_HARD_I2C or CONFIG_SOFT_I2C will 1379 include the appropriate I2C driver for the selected CPU. 1380 1381 This will allow you to use i2c commands at the u-boot 1382 command line (as long as you set CONFIG_CMD_I2C in 1383 CONFIG_COMMANDS) and communicate with i2c based realtime 1384 clock chips. See common/cmd_i2c.c for a description of the 1385 command line interface. 1386 1387 CONFIG_HARD_I2C selects a hardware I2C controller. 1388 1389 CONFIG_SOFT_I2C configures u-boot to use a software (aka 1390 bit-banging) driver instead of CPM or similar hardware 1391 support for I2C. 1392 1393 There are several other quantities that must also be 1394 defined when you define CONFIG_HARD_I2C or CONFIG_SOFT_I2C. 1395 1396 In both cases you will need to define CONFIG_SYS_I2C_SPEED 1397 to be the frequency (in Hz) at which you wish your i2c bus 1398 to run and CONFIG_SYS_I2C_SLAVE to be the address of this node (ie 1399 the CPU's i2c node address). 1400 1401 Now, the u-boot i2c code for the mpc8xx 1402 (arch/powerpc/cpu/mpc8xx/i2c.c) sets the CPU up as a master node 1403 and so its address should therefore be cleared to 0 (See, 1404 eg, MPC823e User's Manual p.16-473). So, set 1405 CONFIG_SYS_I2C_SLAVE to 0. 1406 1407 CONFIG_SYS_I2C_INIT_MPC5XXX 1408 1409 When a board is reset during an i2c bus transfer 1410 chips might think that the current transfer is still 1411 in progress. Reset the slave devices by sending start 1412 commands until the slave device responds. 1413 1414 That's all that's required for CONFIG_HARD_I2C. 1415 1416 If you use the software i2c interface (CONFIG_SOFT_I2C) 1417 then the following macros need to be defined (examples are 1418 from include/configs/lwmon.h): 1419 1420 I2C_INIT 1421 1422 (Optional). Any commands necessary to enable the I2C 1423 controller or configure ports. 1424 1425 eg: #define I2C_INIT (immr->im_cpm.cp_pbdir |= PB_SCL) 1426 1427 I2C_PORT 1428 1429 (Only for MPC8260 CPU). The I/O port to use (the code 1430 assumes both bits are on the same port). Valid values 1431 are 0..3 for ports A..D. 1432 1433 I2C_ACTIVE 1434 1435 The code necessary to make the I2C data line active 1436 (driven). If the data line is open collector, this 1437 define can be null. 1438 1439 eg: #define I2C_ACTIVE (immr->im_cpm.cp_pbdir |= PB_SDA) 1440 1441 I2C_TRISTATE 1442 1443 The code necessary to make the I2C data line tri-stated 1444 (inactive). If the data line is open collector, this 1445 define can be null. 1446 1447 eg: #define I2C_TRISTATE (immr->im_cpm.cp_pbdir &= ~PB_SDA) 1448 1449 I2C_READ 1450 1451 Code that returns TRUE if the I2C data line is high, 1452 FALSE if it is low. 1453 1454 eg: #define I2C_READ ((immr->im_cpm.cp_pbdat & PB_SDA) != 0) 1455 1456 I2C_SDA(bit) 1457 1458 If <bit> is TRUE, sets the I2C data line high. If it 1459 is FALSE, it clears it (low). 1460 1461 eg: #define I2C_SDA(bit) \ 1462 if(bit) immr->im_cpm.cp_pbdat |= PB_SDA; \ 1463 else immr->im_cpm.cp_pbdat &= ~PB_SDA 1464 1465 I2C_SCL(bit) 1466 1467 If <bit> is TRUE, sets the I2C clock line high. If it 1468 is FALSE, it clears it (low). 1469 1470 eg: #define I2C_SCL(bit) \ 1471 if(bit) immr->im_cpm.cp_pbdat |= PB_SCL; \ 1472 else immr->im_cpm.cp_pbdat &= ~PB_SCL 1473 1474 I2C_DELAY 1475 1476 This delay is invoked four times per clock cycle so this 1477 controls the rate of data transfer. The data rate thus 1478 is 1 / (I2C_DELAY * 4). Often defined to be something 1479 like: 1480 1481 #define I2C_DELAY udelay(2) 1482 1483 CONFIG_SOFT_I2C_GPIO_SCL / CONFIG_SOFT_I2C_GPIO_SDA 1484 1485 If your arch supports the generic GPIO framework (asm/gpio.h), 1486 then you may alternatively define the two GPIOs that are to be 1487 used as SCL / SDA. Any of the previous I2C_xxx macros will 1488 have GPIO-based defaults assigned to them as appropriate. 1489 1490 You should define these to the GPIO value as given directly to 1491 the generic GPIO functions. 1492 1493 CONFIG_SYS_I2C_INIT_BOARD 1494 1495 When a board is reset during an i2c bus transfer 1496 chips might think that the current transfer is still 1497 in progress. On some boards it is possible to access 1498 the i2c SCLK line directly, either by using the 1499 processor pin as a GPIO or by having a second pin 1500 connected to the bus. If this option is defined a 1501 custom i2c_init_board() routine in boards/xxx/board.c 1502 is run early in the boot sequence. 1503 1504 CONFIG_SYS_I2C_BOARD_LATE_INIT 1505 1506 An alternative to CONFIG_SYS_I2C_INIT_BOARD. If this option is 1507 defined a custom i2c_board_late_init() routine in 1508 boards/xxx/board.c is run AFTER the operations in i2c_init() 1509 is completed. This callpoint can be used to unreset i2c bus 1510 using CPU i2c controller register accesses for CPUs whose i2c 1511 controller provide such a method. It is called at the end of 1512 i2c_init() to allow i2c_init operations to setup the i2c bus 1513 controller on the CPU (e.g. setting bus speed & slave address). 1514 1515 CONFIG_I2CFAST (PPC405GP|PPC405EP only) 1516 1517 This option enables configuration of bi_iic_fast[] flags 1518 in u-boot bd_info structure based on u-boot environment 1519 variable "i2cfast". (see also i2cfast) 1520 1521 CONFIG_I2C_MULTI_BUS 1522 1523 This option allows the use of multiple I2C buses, each of which 1524 must have a controller. At any point in time, only one bus is 1525 active. To switch to a different bus, use the 'i2c dev' command. 1526 Note that bus numbering is zero-based. 1527 1528 CONFIG_SYS_I2C_NOPROBES 1529 1530 This option specifies a list of I2C devices that will be skipped 1531 when the 'i2c probe' command is issued. If CONFIG_I2C_MULTI_BUS 1532 is set, specify a list of bus-device pairs. Otherwise, specify 1533 a 1D array of device addresses 1534 1535 e.g. 1536 #undef CONFIG_I2C_MULTI_BUS 1537 #define CONFIG_SYS_I2C_NOPROBES {0x50,0x68} 1538 1539 will skip addresses 0x50 and 0x68 on a board with one I2C bus 1540 1541 #define CONFIG_I2C_MULTI_BUS 1542 #define CONFIG_SYS_I2C_MULTI_NOPROBES {{0,0x50},{0,0x68},{1,0x54}} 1543 1544 will skip addresses 0x50 and 0x68 on bus 0 and address 0x54 on bus 1 1545 1546 CONFIG_SYS_SPD_BUS_NUM 1547 1548 If defined, then this indicates the I2C bus number for DDR SPD. 1549 If not defined, then U-Boot assumes that SPD is on I2C bus 0. 1550 1551 CONFIG_SYS_RTC_BUS_NUM 1552 1553 If defined, then this indicates the I2C bus number for the RTC. 1554 If not defined, then U-Boot assumes that RTC is on I2C bus 0. 1555 1556 CONFIG_SYS_DTT_BUS_NUM 1557 1558 If defined, then this indicates the I2C bus number for the DTT. 1559 If not defined, then U-Boot assumes that DTT is on I2C bus 0. 1560 1561 CONFIG_SYS_I2C_DTT_ADDR: 1562 1563 If defined, specifies the I2C address of the DTT device. 1564 If not defined, then U-Boot uses predefined value for 1565 specified DTT device. 1566 1567 CONFIG_FSL_I2C 1568 1569 Define this option if you want to use Freescale's I2C driver in 1570 drivers/i2c/fsl_i2c.c. 1571 1572 CONFIG_I2C_MUX 1573 1574 Define this option if you have I2C devices reached over 1 .. n 1575 I2C Muxes like the pca9544a. This option addes a new I2C 1576 Command "i2c bus [muxtype:muxaddr:muxchannel]" which adds a 1577 new I2C Bus to the existing I2C Busses. If you select the 1578 new Bus with "i2c dev", u-bbot sends first the commandos for 1579 the muxes to activate this new "bus". 1580 1581 CONFIG_I2C_MULTI_BUS must be also defined, to use this 1582 feature! 1583 1584 Example: 1585 Adding a new I2C Bus reached over 2 pca9544a muxes 1586 The First mux with address 70 and channel 6 1587 The Second mux with address 71 and channel 4 1588 1589 => i2c bus pca9544a:70:6:pca9544a:71:4 1590 1591 Use the "i2c bus" command without parameter, to get a list 1592 of I2C Busses with muxes: 1593 1594 => i2c bus 1595 Busses reached over muxes: 1596 Bus ID: 2 1597 reached over Mux(es): 1598 pca9544a@70 ch: 4 1599 Bus ID: 3 1600 reached over Mux(es): 1601 pca9544a@70 ch: 6 1602 pca9544a@71 ch: 4 1603 => 1604 1605 If you now switch to the new I2C Bus 3 with "i2c dev 3" 1606 u-boot sends First the Commando to the mux@70 to enable 1607 channel 6, and then the Commando to the mux@71 to enable 1608 the channel 4. 1609 1610 After that, you can use the "normal" i2c commands as 1611 usual, to communicate with your I2C devices behind 1612 the 2 muxes. 1613 1614 This option is actually implemented for the bitbanging 1615 algorithm in common/soft_i2c.c and for the Hardware I2C 1616 Bus on the MPC8260. But it should be not so difficult 1617 to add this option to other architectures. 1618 1619 CONFIG_SOFT_I2C_READ_REPEATED_START 1620 1621 defining this will force the i2c_read() function in 1622 the soft_i2c driver to perform an I2C repeated start 1623 between writing the address pointer and reading the 1624 data. If this define is omitted the default behaviour 1625 of doing a stop-start sequence will be used. Most I2C 1626 devices can use either method, but some require one or 1627 the other. 1628 1629- SPI Support: CONFIG_SPI 1630 1631 Enables SPI driver (so far only tested with 1632 SPI EEPROM, also an instance works with Crystal A/D and 1633 D/As on the SACSng board) 1634 1635 CONFIG_SPI_X 1636 1637 Enables extended (16-bit) SPI EEPROM addressing. 1638 (symmetrical to CONFIG_I2C_X) 1639 1640 CONFIG_SOFT_SPI 1641 1642 Enables a software (bit-bang) SPI driver rather than 1643 using hardware support. This is a general purpose 1644 driver that only requires three general I/O port pins 1645 (two outputs, one input) to function. If this is 1646 defined, the board configuration must define several 1647 SPI configuration items (port pins to use, etc). For 1648 an example, see include/configs/sacsng.h. 1649 1650 CONFIG_HARD_SPI 1651 1652 Enables a hardware SPI driver for general-purpose reads 1653 and writes. As with CONFIG_SOFT_SPI, the board configuration 1654 must define a list of chip-select function pointers. 1655 Currently supported on some MPC8xxx processors. For an 1656 example, see include/configs/mpc8349emds.h. 1657 1658 CONFIG_MXC_SPI 1659 1660 Enables the driver for the SPI controllers on i.MX and MXC 1661 SoCs. Currently only i.MX31 is supported. 1662 1663- FPGA Support: CONFIG_FPGA 1664 1665 Enables FPGA subsystem. 1666 1667 CONFIG_FPGA_<vendor> 1668 1669 Enables support for specific chip vendors. 1670 (ALTERA, XILINX) 1671 1672 CONFIG_FPGA_<family> 1673 1674 Enables support for FPGA family. 1675 (SPARTAN2, SPARTAN3, VIRTEX2, CYCLONE2, ACEX1K, ACEX) 1676 1677 CONFIG_FPGA_COUNT 1678 1679 Specify the number of FPGA devices to support. 1680 1681 CONFIG_SYS_FPGA_PROG_FEEDBACK 1682 1683 Enable printing of hash marks during FPGA configuration. 1684 1685 CONFIG_SYS_FPGA_CHECK_BUSY 1686 1687 Enable checks on FPGA configuration interface busy 1688 status by the configuration function. This option 1689 will require a board or device specific function to 1690 be written. 1691 1692 CONFIG_FPGA_DELAY 1693 1694 If defined, a function that provides delays in the FPGA 1695 configuration driver. 1696 1697 CONFIG_SYS_FPGA_CHECK_CTRLC 1698 Allow Control-C to interrupt FPGA configuration 1699 1700 CONFIG_SYS_FPGA_CHECK_ERROR 1701 1702 Check for configuration errors during FPGA bitfile 1703 loading. For example, abort during Virtex II 1704 configuration if the INIT_B line goes low (which 1705 indicated a CRC error). 1706 1707 CONFIG_SYS_FPGA_WAIT_INIT 1708 1709 Maximum time to wait for the INIT_B line to deassert 1710 after PROB_B has been deasserted during a Virtex II 1711 FPGA configuration sequence. The default time is 500 1712 ms. 1713 1714 CONFIG_SYS_FPGA_WAIT_BUSY 1715 1716 Maximum time to wait for BUSY to deassert during 1717 Virtex II FPGA configuration. The default is 5 ms. 1718 1719 CONFIG_SYS_FPGA_WAIT_CONFIG 1720 1721 Time to wait after FPGA configuration. The default is 1722 200 ms. 1723 1724- Configuration Management: 1725 CONFIG_IDENT_STRING 1726 1727 If defined, this string will be added to the U-Boot 1728 version information (U_BOOT_VERSION) 1729 1730- Vendor Parameter Protection: 1731 1732 U-Boot considers the values of the environment 1733 variables "serial#" (Board Serial Number) and 1734 "ethaddr" (Ethernet Address) to be parameters that 1735 are set once by the board vendor / manufacturer, and 1736 protects these variables from casual modification by 1737 the user. Once set, these variables are read-only, 1738 and write or delete attempts are rejected. You can 1739 change this behaviour: 1740 1741 If CONFIG_ENV_OVERWRITE is #defined in your config 1742 file, the write protection for vendor parameters is 1743 completely disabled. Anybody can change or delete 1744 these parameters. 1745 1746 Alternatively, if you #define _both_ CONFIG_ETHADDR 1747 _and_ CONFIG_OVERWRITE_ETHADDR_ONCE, a default 1748 Ethernet address is installed in the environment, 1749 which can be changed exactly ONCE by the user. [The 1750 serial# is unaffected by this, i. e. it remains 1751 read-only.] 1752 1753- Protected RAM: 1754 CONFIG_PRAM 1755 1756 Define this variable to enable the reservation of 1757 "protected RAM", i. e. RAM which is not overwritten 1758 by U-Boot. Define CONFIG_PRAM to hold the number of 1759 kB you want to reserve for pRAM. You can overwrite 1760 this default value by defining an environment 1761 variable "pram" to the number of kB you want to 1762 reserve. Note that the board info structure will 1763 still show the full amount of RAM. If pRAM is 1764 reserved, a new environment variable "mem" will 1765 automatically be defined to hold the amount of 1766 remaining RAM in a form that can be passed as boot 1767 argument to Linux, for instance like that: 1768 1769 setenv bootargs ... mem=\${mem} 1770 saveenv 1771 1772 This way you can tell Linux not to use this memory, 1773 either, which results in a memory region that will 1774 not be affected by reboots. 1775 1776 *WARNING* If your board configuration uses automatic 1777 detection of the RAM size, you must make sure that 1778 this memory test is non-destructive. So far, the 1779 following board configurations are known to be 1780 "pRAM-clean": 1781 1782 ETX094, IVMS8, IVML24, SPD8xx, TQM8xxL, 1783 HERMES, IP860, RPXlite, LWMON, LANTEC, 1784 FLAGADM, TQM8260 1785 1786- Error Recovery: 1787 CONFIG_PANIC_HANG 1788 1789 Define this variable to stop the system in case of a 1790 fatal error, so that you have to reset it manually. 1791 This is probably NOT a good idea for an embedded 1792 system where you want the system to reboot 1793 automatically as fast as possible, but it may be 1794 useful during development since you can try to debug 1795 the conditions that lead to the situation. 1796 1797 CONFIG_NET_RETRY_COUNT 1798 1799 This variable defines the number of retries for 1800 network operations like ARP, RARP, TFTP, or BOOTP 1801 before giving up the operation. If not defined, a 1802 default value of 5 is used. 1803 1804 CONFIG_ARP_TIMEOUT 1805 1806 Timeout waiting for an ARP reply in milliseconds. 1807 1808- Command Interpreter: 1809 CONFIG_AUTO_COMPLETE 1810 1811 Enable auto completion of commands using TAB. 1812 1813 Note that this feature has NOT been implemented yet 1814 for the "hush" shell. 1815 1816 1817 CONFIG_SYS_HUSH_PARSER 1818 1819 Define this variable to enable the "hush" shell (from 1820 Busybox) as command line interpreter, thus enabling 1821 powerful command line syntax like 1822 if...then...else...fi conditionals or `&&' and '||' 1823 constructs ("shell scripts"). 1824 1825 If undefined, you get the old, much simpler behaviour 1826 with a somewhat smaller memory footprint. 1827 1828 1829 CONFIG_SYS_PROMPT_HUSH_PS2 1830 1831 This defines the secondary prompt string, which is 1832 printed when the command interpreter needs more input 1833 to complete a command. Usually "> ". 1834 1835 Note: 1836 1837 In the current implementation, the local variables 1838 space and global environment variables space are 1839 separated. Local variables are those you define by 1840 simply typing `name=value'. To access a local 1841 variable later on, you have write `$name' or 1842 `${name}'; to execute the contents of a variable 1843 directly type `$name' at the command prompt. 1844 1845 Global environment variables are those you use 1846 setenv/printenv to work with. To run a command stored 1847 in such a variable, you need to use the run command, 1848 and you must not use the '$' sign to access them. 1849 1850 To store commands and special characters in a 1851 variable, please use double quotation marks 1852 surrounding the whole text of the variable, instead 1853 of the backslashes before semicolons and special 1854 symbols. 1855 1856- Commandline Editing and History: 1857 CONFIG_CMDLINE_EDITING 1858 1859 Enable editing and History functions for interactive 1860 commandline input operations 1861 1862- Default Environment: 1863 CONFIG_EXTRA_ENV_SETTINGS 1864 1865 Define this to contain any number of null terminated 1866 strings (variable = value pairs) that will be part of 1867 the default environment compiled into the boot image. 1868 1869 For example, place something like this in your 1870 board's config file: 1871 1872 #define CONFIG_EXTRA_ENV_SETTINGS \ 1873 "myvar1=value1\0" \ 1874 "myvar2=value2\0" 1875 1876 Warning: This method is based on knowledge about the 1877 internal format how the environment is stored by the 1878 U-Boot code. This is NOT an official, exported 1879 interface! Although it is unlikely that this format 1880 will change soon, there is no guarantee either. 1881 You better know what you are doing here. 1882 1883 Note: overly (ab)use of the default environment is 1884 discouraged. Make sure to check other ways to preset 1885 the environment like the "source" command or the 1886 boot command first. 1887 1888- DataFlash Support: 1889 CONFIG_HAS_DATAFLASH 1890 1891 Defining this option enables DataFlash features and 1892 allows to read/write in Dataflash via the standard 1893 commands cp, md... 1894 1895- SystemACE Support: 1896 CONFIG_SYSTEMACE 1897 1898 Adding this option adds support for Xilinx SystemACE 1899 chips attached via some sort of local bus. The address 1900 of the chip must also be defined in the 1901 CONFIG_SYS_SYSTEMACE_BASE macro. For example: 1902 1903 #define CONFIG_SYSTEMACE 1904 #define CONFIG_SYS_SYSTEMACE_BASE 0xf0000000 1905 1906 When SystemACE support is added, the "ace" device type 1907 becomes available to the fat commands, i.e. fatls. 1908 1909- TFTP Fixed UDP Port: 1910 CONFIG_TFTP_PORT 1911 1912 If this is defined, the environment variable tftpsrcp 1913 is used to supply the TFTP UDP source port value. 1914 If tftpsrcp isn't defined, the normal pseudo-random port 1915 number generator is used. 1916 1917 Also, the environment variable tftpdstp is used to supply 1918 the TFTP UDP destination port value. If tftpdstp isn't 1919 defined, the normal port 69 is used. 1920 1921 The purpose for tftpsrcp is to allow a TFTP server to 1922 blindly start the TFTP transfer using the pre-configured 1923 target IP address and UDP port. This has the effect of 1924 "punching through" the (Windows XP) firewall, allowing 1925 the remainder of the TFTP transfer to proceed normally. 1926 A better solution is to properly configure the firewall, 1927 but sometimes that is not allowed. 1928 1929- Show boot progress: 1930 CONFIG_SHOW_BOOT_PROGRESS 1931 1932 Defining this option allows to add some board- 1933 specific code (calling a user-provided function 1934 "show_boot_progress(int)") that enables you to show 1935 the system's boot progress on some display (for 1936 example, some LED's) on your board. At the moment, 1937 the following checkpoints are implemented: 1938 1939Legacy uImage format: 1940 1941 Arg Where When 1942 1 common/cmd_bootm.c before attempting to boot an image 1943 -1 common/cmd_bootm.c Image header has bad magic number 1944 2 common/cmd_bootm.c Image header has correct magic number 1945 -2 common/cmd_bootm.c Image header has bad checksum 1946 3 common/cmd_bootm.c Image header has correct checksum 1947 -3 common/cmd_bootm.c Image data has bad checksum 1948 4 common/cmd_bootm.c Image data has correct checksum 1949 -4 common/cmd_bootm.c Image is for unsupported architecture 1950 5 common/cmd_bootm.c Architecture check OK 1951 -5 common/cmd_bootm.c Wrong Image Type (not kernel, multi) 1952 6 common/cmd_bootm.c Image Type check OK 1953 -6 common/cmd_bootm.c gunzip uncompression error 1954 -7 common/cmd_bootm.c Unimplemented compression type 1955 7 common/cmd_bootm.c Uncompression OK 1956 8 common/cmd_bootm.c No uncompress/copy overwrite error 1957 -9 common/cmd_bootm.c Unsupported OS (not Linux, BSD, VxWorks, QNX) 1958 1959 9 common/image.c Start initial ramdisk verification 1960 -10 common/image.c Ramdisk header has bad magic number 1961 -11 common/image.c Ramdisk header has bad checksum 1962 10 common/image.c Ramdisk header is OK 1963 -12 common/image.c Ramdisk data has bad checksum 1964 11 common/image.c Ramdisk data has correct checksum 1965 12 common/image.c Ramdisk verification complete, start loading 1966 -13 common/image.c Wrong Image Type (not PPC Linux ramdisk) 1967 13 common/image.c Start multifile image verification 1968 14 common/image.c No initial ramdisk, no multifile, continue. 1969 1970 15 arch/<arch>/lib/bootm.c All preparation done, transferring control to OS 1971 1972 -30 arch/powerpc/lib/board.c Fatal error, hang the system 1973 -31 post/post.c POST test failed, detected by post_output_backlog() 1974 -32 post/post.c POST test failed, detected by post_run_single() 1975 1976 34 common/cmd_doc.c before loading a Image from a DOC device 1977 -35 common/cmd_doc.c Bad usage of "doc" command 1978 35 common/cmd_doc.c correct usage of "doc" command 1979 -36 common/cmd_doc.c No boot device 1980 36 common/cmd_doc.c correct boot device 1981 -37 common/cmd_doc.c Unknown Chip ID on boot device 1982 37 common/cmd_doc.c correct chip ID found, device available 1983 -38 common/cmd_doc.c Read Error on boot device 1984 38 common/cmd_doc.c reading Image header from DOC device OK 1985 -39 common/cmd_doc.c Image header has bad magic number 1986 39 common/cmd_doc.c Image header has correct magic number 1987 -40 common/cmd_doc.c Error reading Image from DOC device 1988 40 common/cmd_doc.c Image header has correct magic number 1989 41 common/cmd_ide.c before loading a Image from a IDE device 1990 -42 common/cmd_ide.c Bad usage of "ide" command 1991 42 common/cmd_ide.c correct usage of "ide" command 1992 -43 common/cmd_ide.c No boot device 1993 43 common/cmd_ide.c boot device found 1994 -44 common/cmd_ide.c Device not available 1995 44 common/cmd_ide.c Device available 1996 -45 common/cmd_ide.c wrong partition selected 1997 45 common/cmd_ide.c partition selected 1998 -46 common/cmd_ide.c Unknown partition table 1999 46 common/cmd_ide.c valid partition table found 2000 -47 common/cmd_ide.c Invalid partition type 2001 47 common/cmd_ide.c correct partition type 2002 -48 common/cmd_ide.c Error reading Image Header on boot device 2003 48 common/cmd_ide.c reading Image Header from IDE device OK 2004 -49 common/cmd_ide.c Image header has bad magic number 2005 49 common/cmd_ide.c Image header has correct magic number 2006 -50 common/cmd_ide.c Image header has bad checksum 2007 50 common/cmd_ide.c Image header has correct checksum 2008 -51 common/cmd_ide.c Error reading Image from IDE device 2009 51 common/cmd_ide.c reading Image from IDE device OK 2010 52 common/cmd_nand.c before loading a Image from a NAND device 2011 -53 common/cmd_nand.c Bad usage of "nand" command 2012 53 common/cmd_nand.c correct usage of "nand" command 2013 -54 common/cmd_nand.c No boot device 2014 54 common/cmd_nand.c boot device found 2015 -55 common/cmd_nand.c Unknown Chip ID on boot device 2016 55 common/cmd_nand.c correct chip ID found, device available 2017 -56 common/cmd_nand.c Error reading Image Header on boot device 2018 56 common/cmd_nand.c reading Image Header from NAND device OK 2019 -57 common/cmd_nand.c Image header has bad magic number 2020 57 common/cmd_nand.c Image header has correct magic number 2021 -58 common/cmd_nand.c Error reading Image from NAND device 2022 58 common/cmd_nand.c reading Image from NAND device OK 2023 2024 -60 common/env_common.c Environment has a bad CRC, using default 2025 2026 64 net/eth.c starting with Ethernet configuration. 2027 -64 net/eth.c no Ethernet found. 2028 65 net/eth.c Ethernet found. 2029 2030 -80 common/cmd_net.c usage wrong 2031 80 common/cmd_net.c before calling NetLoop() 2032 -81 common/cmd_net.c some error in NetLoop() occurred 2033 81 common/cmd_net.c NetLoop() back without error 2034 -82 common/cmd_net.c size == 0 (File with size 0 loaded) 2035 82 common/cmd_net.c trying automatic boot 2036 83 common/cmd_net.c running "source" command 2037 -83 common/cmd_net.c some error in automatic boot or "source" command 2038 84 common/cmd_net.c end without errors 2039 2040FIT uImage format: 2041 2042 Arg Where When 2043 100 common/cmd_bootm.c Kernel FIT Image has correct format 2044 -100 common/cmd_bootm.c Kernel FIT Image has incorrect format 2045 101 common/cmd_bootm.c No Kernel subimage unit name, using configuration 2046 -101 common/cmd_bootm.c Can't get configuration for kernel subimage 2047 102 common/cmd_bootm.c Kernel unit name specified 2048 -103 common/cmd_bootm.c Can't get kernel subimage node offset 2049 103 common/cmd_bootm.c Found configuration node 2050 104 common/cmd_bootm.c Got kernel subimage node offset 2051 -104 common/cmd_bootm.c Kernel subimage hash verification failed 2052 105 common/cmd_bootm.c Kernel subimage hash verification OK 2053 -105 common/cmd_bootm.c Kernel subimage is for unsupported architecture 2054 106 common/cmd_bootm.c Architecture check OK 2055 -106 common/cmd_bootm.c Kernel subimage has wrong type 2056 107 common/cmd_bootm.c Kernel subimage type OK 2057 -107 common/cmd_bootm.c Can't get kernel subimage data/size 2058 108 common/cmd_bootm.c Got kernel subimage data/size 2059 -108 common/cmd_bootm.c Wrong image type (not legacy, FIT) 2060 -109 common/cmd_bootm.c Can't get kernel subimage type 2061 -110 common/cmd_bootm.c Can't get kernel subimage comp 2062 -111 common/cmd_bootm.c Can't get kernel subimage os 2063 -112 common/cmd_bootm.c Can't get kernel subimage load address 2064 -113 common/cmd_bootm.c Image uncompress/copy overwrite error 2065 2066 120 common/image.c Start initial ramdisk verification 2067 -120 common/image.c Ramdisk FIT image has incorrect format 2068 121 common/image.c Ramdisk FIT image has correct format 2069 122 common/image.c No ramdisk subimage unit name, using configuration 2070 -122 common/image.c Can't get configuration for ramdisk subimage 2071 123 common/image.c Ramdisk unit name specified 2072 -124 common/image.c Can't get ramdisk subimage node offset 2073 125 common/image.c Got ramdisk subimage node offset 2074 -125 common/image.c Ramdisk subimage hash verification failed 2075 126 common/image.c Ramdisk subimage hash verification OK 2076 -126 common/image.c Ramdisk subimage for unsupported architecture 2077 127 common/image.c Architecture check OK 2078 -127 common/image.c Can't get ramdisk subimage data/size 2079 128 common/image.c Got ramdisk subimage data/size 2080 129 common/image.c Can't get ramdisk load address 2081 -129 common/image.c Got ramdisk load address 2082 2083 -130 common/cmd_doc.c Incorrect FIT image format 2084 131 common/cmd_doc.c FIT image format OK 2085 2086 -140 common/cmd_ide.c Incorrect FIT image format 2087 141 common/cmd_ide.c FIT image format OK 2088 2089 -150 common/cmd_nand.c Incorrect FIT image format 2090 151 common/cmd_nand.c FIT image format OK 2091 2092- Automatic software updates via TFTP server 2093 CONFIG_UPDATE_TFTP 2094 CONFIG_UPDATE_TFTP_CNT_MAX 2095 CONFIG_UPDATE_TFTP_MSEC_MAX 2096 2097 These options enable and control the auto-update feature; 2098 for a more detailed description refer to doc/README.update. 2099 2100- MTD Support (mtdparts command, UBI support) 2101 CONFIG_MTD_DEVICE 2102 2103 Adds the MTD device infrastructure from the Linux kernel. 2104 Needed for mtdparts command support. 2105 2106 CONFIG_MTD_PARTITIONS 2107 2108 Adds the MTD partitioning infrastructure from the Linux 2109 kernel. Needed for UBI support. 2110 2111 2112Modem Support: 2113-------------- 2114 2115[so far only for SMDK2400 and TRAB boards] 2116 2117- Modem support enable: 2118 CONFIG_MODEM_SUPPORT 2119 2120- RTS/CTS Flow control enable: 2121 CONFIG_HWFLOW 2122 2123- Modem debug support: 2124 CONFIG_MODEM_SUPPORT_DEBUG 2125 2126 Enables debugging stuff (char screen[1024], dbg()) 2127 for modem support. Useful only with BDI2000. 2128 2129- Interrupt support (PPC): 2130 2131 There are common interrupt_init() and timer_interrupt() 2132 for all PPC archs. interrupt_init() calls interrupt_init_cpu() 2133 for CPU specific initialization. interrupt_init_cpu() 2134 should set decrementer_count to appropriate value. If 2135 CPU resets decrementer automatically after interrupt 2136 (ppc4xx) it should set decrementer_count to zero. 2137 timer_interrupt() calls timer_interrupt_cpu() for CPU 2138 specific handling. If board has watchdog / status_led 2139 / other_activity_monitor it works automatically from 2140 general timer_interrupt(). 2141 2142- General: 2143 2144 In the target system modem support is enabled when a 2145 specific key (key combination) is pressed during 2146 power-on. Otherwise U-Boot will boot normally 2147 (autoboot). The key_pressed() function is called from 2148 board_init(). Currently key_pressed() is a dummy 2149 function, returning 1 and thus enabling modem 2150 initialization. 2151 2152 If there are no modem init strings in the 2153 environment, U-Boot proceed to autoboot; the 2154 previous output (banner, info printfs) will be 2155 suppressed, though. 2156 2157 See also: doc/README.Modem 2158 2159 2160Configuration Settings: 2161----------------------- 2162 2163- CONFIG_SYS_LONGHELP: Defined when you want long help messages included; 2164 undefine this when you're short of memory. 2165 2166- CONFIG_SYS_HELP_CMD_WIDTH: Defined when you want to override the default 2167 width of the commands listed in the 'help' command output. 2168 2169- CONFIG_SYS_PROMPT: This is what U-Boot prints on the console to 2170 prompt for user input. 2171 2172- CONFIG_SYS_CBSIZE: Buffer size for input from the Console 2173 2174- CONFIG_SYS_PBSIZE: Buffer size for Console output 2175 2176- CONFIG_SYS_MAXARGS: max. Number of arguments accepted for monitor commands 2177 2178- CONFIG_SYS_BARGSIZE: Buffer size for Boot Arguments which are passed to 2179 the application (usually a Linux kernel) when it is 2180 booted 2181 2182- CONFIG_SYS_BAUDRATE_TABLE: 2183 List of legal baudrate settings for this board. 2184 2185- CONFIG_SYS_CONSOLE_INFO_QUIET 2186 Suppress display of console information at boot. 2187 2188- CONFIG_SYS_CONSOLE_IS_IN_ENV 2189 If the board specific function 2190 extern int overwrite_console (void); 2191 returns 1, the stdin, stderr and stdout are switched to the 2192 serial port, else the settings in the environment are used. 2193 2194- CONFIG_SYS_CONSOLE_OVERWRITE_ROUTINE 2195 Enable the call to overwrite_console(). 2196 2197- CONFIG_SYS_CONSOLE_ENV_OVERWRITE 2198 Enable overwrite of previous console environment settings. 2199 2200- CONFIG_SYS_MEMTEST_START, CONFIG_SYS_MEMTEST_END: 2201 Begin and End addresses of the area used by the 2202 simple memory test. 2203 2204- CONFIG_SYS_ALT_MEMTEST: 2205 Enable an alternate, more extensive memory test. 2206 2207- CONFIG_SYS_MEMTEST_SCRATCH: 2208 Scratch address used by the alternate memory test 2209 You only need to set this if address zero isn't writeable 2210 2211- CONFIG_SYS_MEM_TOP_HIDE (PPC only): 2212 If CONFIG_SYS_MEM_TOP_HIDE is defined in the board config header, 2213 this specified memory area will get subtracted from the top 2214 (end) of RAM and won't get "touched" at all by U-Boot. By 2215 fixing up gd->ram_size the Linux kernel should gets passed 2216 the now "corrected" memory size and won't touch it either. 2217 This should work for arch/ppc and arch/powerpc. Only Linux 2218 board ports in arch/powerpc with bootwrapper support that 2219 recalculate the memory size from the SDRAM controller setup 2220 will have to get fixed in Linux additionally. 2221 2222 This option can be used as a workaround for the 440EPx/GRx 2223 CHIP 11 errata where the last 256 bytes in SDRAM shouldn't 2224 be touched. 2225 2226 WARNING: Please make sure that this value is a multiple of 2227 the Linux page size (normally 4k). If this is not the case, 2228 then the end address of the Linux memory will be located at a 2229 non page size aligned address and this could cause major 2230 problems. 2231 2232- CONFIG_SYS_TFTP_LOADADDR: 2233 Default load address for network file downloads 2234 2235- CONFIG_SYS_LOADS_BAUD_CHANGE: 2236 Enable temporary baudrate change while serial download 2237 2238- CONFIG_SYS_SDRAM_BASE: 2239 Physical start address of SDRAM. _Must_ be 0 here. 2240 2241- CONFIG_SYS_MBIO_BASE: 2242 Physical start address of Motherboard I/O (if using a 2243 Cogent motherboard) 2244 2245- CONFIG_SYS_FLASH_BASE: 2246 Physical start address of Flash memory. 2247 2248- CONFIG_SYS_MONITOR_BASE: 2249 Physical start address of boot monitor code (set by 2250 make config files to be same as the text base address 2251 (CONFIG_SYS_TEXT_BASE) used when linking) - same as 2252 CONFIG_SYS_FLASH_BASE when booting from flash. 2253 2254- CONFIG_SYS_MONITOR_LEN: 2255 Size of memory reserved for monitor code, used to 2256 determine _at_compile_time_ (!) if the environment is 2257 embedded within the U-Boot image, or in a separate 2258 flash sector. 2259 2260- CONFIG_SYS_MALLOC_LEN: 2261 Size of DRAM reserved for malloc() use. 2262 2263- CONFIG_SYS_BOOTM_LEN: 2264 Normally compressed uImages are limited to an 2265 uncompressed size of 8 MBytes. If this is not enough, 2266 you can define CONFIG_SYS_BOOTM_LEN in your board config file 2267 to adjust this setting to your needs. 2268 2269- CONFIG_SYS_BOOTMAPSZ: 2270 Maximum size of memory mapped by the startup code of 2271 the Linux kernel; all data that must be processed by 2272 the Linux kernel (bd_info, boot arguments, FDT blob if 2273 used) must be put below this limit, unless "bootm_low" 2274 enviroment variable is defined and non-zero. In such case 2275 all data for the Linux kernel must be between "bootm_low" 2276 and "bootm_low" + CONFIG_SYS_BOOTMAPSZ. 2277 2278- CONFIG_SYS_BOOT_RAMDISK_HIGH: 2279 Enable initrd_high functionality. If defined then the 2280 initrd_high feature is enabled and the bootm ramdisk subcommand 2281 is enabled. 2282 2283- CONFIG_SYS_BOOT_GET_CMDLINE: 2284 Enables allocating and saving kernel cmdline in space between 2285 "bootm_low" and "bootm_low" + BOOTMAPSZ. 2286 2287- CONFIG_SYS_BOOT_GET_KBD: 2288 Enables allocating and saving a kernel copy of the bd_info in 2289 space between "bootm_low" and "bootm_low" + BOOTMAPSZ. 2290 2291- CONFIG_SYS_MAX_FLASH_BANKS: 2292 Max number of Flash memory banks 2293 2294- CONFIG_SYS_MAX_FLASH_SECT: 2295 Max number of sectors on a Flash chip 2296 2297- CONFIG_SYS_FLASH_ERASE_TOUT: 2298 Timeout for Flash erase operations (in ms) 2299 2300- CONFIG_SYS_FLASH_WRITE_TOUT: 2301 Timeout for Flash write operations (in ms) 2302 2303- CONFIG_SYS_FLASH_LOCK_TOUT 2304 Timeout for Flash set sector lock bit operation (in ms) 2305 2306- CONFIG_SYS_FLASH_UNLOCK_TOUT 2307 Timeout for Flash clear lock bits operation (in ms) 2308 2309- CONFIG_SYS_FLASH_PROTECTION 2310 If defined, hardware flash sectors protection is used 2311 instead of U-Boot software protection. 2312 2313- CONFIG_SYS_DIRECT_FLASH_TFTP: 2314 2315 Enable TFTP transfers directly to flash memory; 2316 without this option such a download has to be 2317 performed in two steps: (1) download to RAM, and (2) 2318 copy from RAM to flash. 2319 2320 The two-step approach is usually more reliable, since 2321 you can check if the download worked before you erase 2322 the flash, but in some situations (when system RAM is 2323 too limited to allow for a temporary copy of the 2324 downloaded image) this option may be very useful. 2325 2326- CONFIG_SYS_FLASH_CFI: 2327 Define if the flash driver uses extra elements in the 2328 common flash structure for storing flash geometry. 2329 2330- CONFIG_FLASH_CFI_DRIVER 2331 This option also enables the building of the cfi_flash driver 2332 in the drivers directory 2333 2334- CONFIG_FLASH_CFI_MTD 2335 This option enables the building of the cfi_mtd driver 2336 in the drivers directory. The driver exports CFI flash 2337 to the MTD layer. 2338 2339- CONFIG_SYS_FLASH_USE_BUFFER_WRITE 2340 Use buffered writes to flash. 2341 2342- CONFIG_FLASH_SPANSION_S29WS_N 2343 s29ws-n MirrorBit flash has non-standard addresses for buffered 2344 write commands. 2345 2346- CONFIG_SYS_FLASH_QUIET_TEST 2347 If this option is defined, the common CFI flash doesn't 2348 print it's warning upon not recognized FLASH banks. This 2349 is useful, if some of the configured banks are only 2350 optionally available. 2351 2352- CONFIG_FLASH_SHOW_PROGRESS 2353 If defined (must be an integer), print out countdown 2354 digits and dots. Recommended value: 45 (9..1) for 80 2355 column displays, 15 (3..1) for 40 column displays. 2356 2357- CONFIG_SYS_RX_ETH_BUFFER: 2358 Defines the number of Ethernet receive buffers. On some 2359 Ethernet controllers it is recommended to set this value 2360 to 8 or even higher (EEPRO100 or 405 EMAC), since all 2361 buffers can be full shortly after enabling the interface 2362 on high Ethernet traffic. 2363 Defaults to 4 if not defined. 2364 2365- CONFIG_ENV_MAX_ENTRIES 2366 2367 Maximum number of entries in the hash table that is used 2368 internally to store the environment settings. The default 2369 setting is supposed to be generous and should work in most 2370 cases. This setting can be used to tune behaviour; see 2371 lib/hashtable.c for details. 2372 2373The following definitions that deal with the placement and management 2374of environment data (variable area); in general, we support the 2375following configurations: 2376 2377- CONFIG_ENV_IS_IN_FLASH: 2378 2379 Define this if the environment is in flash memory. 2380 2381 a) The environment occupies one whole flash sector, which is 2382 "embedded" in the text segment with the U-Boot code. This 2383 happens usually with "bottom boot sector" or "top boot 2384 sector" type flash chips, which have several smaller 2385 sectors at the start or the end. For instance, such a 2386 layout can have sector sizes of 8, 2x4, 16, Nx32 kB. In 2387 such a case you would place the environment in one of the 2388 4 kB sectors - with U-Boot code before and after it. With 2389 "top boot sector" type flash chips, you would put the 2390 environment in one of the last sectors, leaving a gap 2391 between U-Boot and the environment. 2392 2393 - CONFIG_ENV_OFFSET: 2394 2395 Offset of environment data (variable area) to the 2396 beginning of flash memory; for instance, with bottom boot 2397 type flash chips the second sector can be used: the offset 2398 for this sector is given here. 2399 2400 CONFIG_ENV_OFFSET is used relative to CONFIG_SYS_FLASH_BASE. 2401 2402 - CONFIG_ENV_ADDR: 2403 2404 This is just another way to specify the start address of 2405 the flash sector containing the environment (instead of 2406 CONFIG_ENV_OFFSET). 2407 2408 - CONFIG_ENV_SECT_SIZE: 2409 2410 Size of the sector containing the environment. 2411 2412 2413 b) Sometimes flash chips have few, equal sized, BIG sectors. 2414 In such a case you don't want to spend a whole sector for 2415 the environment. 2416 2417 - CONFIG_ENV_SIZE: 2418 2419 If you use this in combination with CONFIG_ENV_IS_IN_FLASH 2420 and CONFIG_ENV_SECT_SIZE, you can specify to use only a part 2421 of this flash sector for the environment. This saves 2422 memory for the RAM copy of the environment. 2423 2424 It may also save flash memory if you decide to use this 2425 when your environment is "embedded" within U-Boot code, 2426 since then the remainder of the flash sector could be used 2427 for U-Boot code. It should be pointed out that this is 2428 STRONGLY DISCOURAGED from a robustness point of view: 2429 updating the environment in flash makes it always 2430 necessary to erase the WHOLE sector. If something goes 2431 wrong before the contents has been restored from a copy in 2432 RAM, your target system will be dead. 2433 2434 - CONFIG_ENV_ADDR_REDUND 2435 CONFIG_ENV_SIZE_REDUND 2436 2437 These settings describe a second storage area used to hold 2438 a redundant copy of the environment data, so that there is 2439 a valid backup copy in case there is a power failure during 2440 a "saveenv" operation. 2441 2442BE CAREFUL! Any changes to the flash layout, and some changes to the 2443source code will make it necessary to adapt <board>/u-boot.lds* 2444accordingly! 2445 2446 2447- CONFIG_ENV_IS_IN_NVRAM: 2448 2449 Define this if you have some non-volatile memory device 2450 (NVRAM, battery buffered SRAM) which you want to use for the 2451 environment. 2452 2453 - CONFIG_ENV_ADDR: 2454 - CONFIG_ENV_SIZE: 2455 2456 These two #defines are used to determine the memory area you 2457 want to use for environment. It is assumed that this memory 2458 can just be read and written to, without any special 2459 provision. 2460 2461BE CAREFUL! The first access to the environment happens quite early 2462in U-Boot initalization (when we try to get the setting of for the 2463console baudrate). You *MUST* have mapped your NVRAM area then, or 2464U-Boot will hang. 2465 2466Please note that even with NVRAM we still use a copy of the 2467environment in RAM: we could work on NVRAM directly, but we want to 2468keep settings there always unmodified except somebody uses "saveenv" 2469to save the current settings. 2470 2471 2472- CONFIG_ENV_IS_IN_EEPROM: 2473 2474 Use this if you have an EEPROM or similar serial access 2475 device and a driver for it. 2476 2477 - CONFIG_ENV_OFFSET: 2478 - CONFIG_ENV_SIZE: 2479 2480 These two #defines specify the offset and size of the 2481 environment area within the total memory of your EEPROM. 2482 2483 - CONFIG_SYS_I2C_EEPROM_ADDR: 2484 If defined, specified the chip address of the EEPROM device. 2485 The default address is zero. 2486 2487 - CONFIG_SYS_EEPROM_PAGE_WRITE_BITS: 2488 If defined, the number of bits used to address bytes in a 2489 single page in the EEPROM device. A 64 byte page, for example 2490 would require six bits. 2491 2492 - CONFIG_SYS_EEPROM_PAGE_WRITE_DELAY_MS: 2493 If defined, the number of milliseconds to delay between 2494 page writes. The default is zero milliseconds. 2495 2496 - CONFIG_SYS_I2C_EEPROM_ADDR_LEN: 2497 The length in bytes of the EEPROM memory array address. Note 2498 that this is NOT the chip address length! 2499 2500 - CONFIG_SYS_I2C_EEPROM_ADDR_OVERFLOW: 2501 EEPROM chips that implement "address overflow" are ones 2502 like Catalyst 24WC04/08/16 which has 9/10/11 bits of 2503 address and the extra bits end up in the "chip address" bit 2504 slots. This makes a 24WC08 (1Kbyte) chip look like four 256 2505 byte chips. 2506 2507 Note that we consider the length of the address field to 2508 still be one byte because the extra address bits are hidden 2509 in the chip address. 2510 2511 - CONFIG_SYS_EEPROM_SIZE: 2512 The size in bytes of the EEPROM device. 2513 2514 - CONFIG_ENV_EEPROM_IS_ON_I2C 2515 define this, if you have I2C and SPI activated, and your 2516 EEPROM, which holds the environment, is on the I2C bus. 2517 2518 - CONFIG_I2C_ENV_EEPROM_BUS 2519 if you have an Environment on an EEPROM reached over 2520 I2C muxes, you can define here, how to reach this 2521 EEPROM. For example: 2522 2523 #define CONFIG_I2C_ENV_EEPROM_BUS "pca9547:70:d\0" 2524 2525 EEPROM which holds the environment, is reached over 2526 a pca9547 i2c mux with address 0x70, channel 3. 2527 2528- CONFIG_ENV_IS_IN_DATAFLASH: 2529 2530 Define this if you have a DataFlash memory device which you 2531 want to use for the environment. 2532 2533 - CONFIG_ENV_OFFSET: 2534 - CONFIG_ENV_ADDR: 2535 - CONFIG_ENV_SIZE: 2536 2537 These three #defines specify the offset and size of the 2538 environment area within the total memory of your DataFlash placed 2539 at the specified address. 2540 2541- CONFIG_ENV_IS_IN_NAND: 2542 2543 Define this if you have a NAND device which you want to use 2544 for the environment. 2545 2546 - CONFIG_ENV_OFFSET: 2547 - CONFIG_ENV_SIZE: 2548 2549 These two #defines specify the offset and size of the environment 2550 area within the first NAND device. CONFIG_ENV_OFFSET must be 2551 aligned to an erase block boundary. 2552 2553 - CONFIG_ENV_OFFSET_REDUND (optional): 2554 2555 This setting describes a second storage area of CONFIG_ENV_SIZE 2556 size used to hold a redundant copy of the environment data, so 2557 that there is a valid backup copy in case there is a power failure 2558 during a "saveenv" operation. CONFIG_ENV_OFFSET_RENDUND must be 2559 aligned to an erase block boundary. 2560 2561 - CONFIG_ENV_RANGE (optional): 2562 2563 Specifies the length of the region in which the environment 2564 can be written. This should be a multiple of the NAND device's 2565 block size. Specifying a range with more erase blocks than 2566 are needed to hold CONFIG_ENV_SIZE allows bad blocks within 2567 the range to be avoided. 2568 2569 - CONFIG_ENV_OFFSET_OOB (optional): 2570 2571 Enables support for dynamically retrieving the offset of the 2572 environment from block zero's out-of-band data. The 2573 "nand env.oob" command can be used to record this offset. 2574 Currently, CONFIG_ENV_OFFSET_REDUND is not supported when 2575 using CONFIG_ENV_OFFSET_OOB. 2576 2577- CONFIG_NAND_ENV_DST 2578 2579 Defines address in RAM to which the nand_spl code should copy the 2580 environment. If redundant environment is used, it will be copied to 2581 CONFIG_NAND_ENV_DST + CONFIG_ENV_SIZE. 2582 2583- CONFIG_SYS_SPI_INIT_OFFSET 2584 2585 Defines offset to the initial SPI buffer area in DPRAM. The 2586 area is used at an early stage (ROM part) if the environment 2587 is configured to reside in the SPI EEPROM: We need a 520 byte 2588 scratch DPRAM area. It is used between the two initialization 2589 calls (spi_init_f() and spi_init_r()). A value of 0xB00 seems 2590 to be a good choice since it makes it far enough from the 2591 start of the data area as well as from the stack pointer. 2592 2593Please note that the environment is read-only until the monitor 2594has been relocated to RAM and a RAM copy of the environment has been 2595created; also, when using EEPROM you will have to use getenv_f() 2596until then to read environment variables. 2597 2598The environment is protected by a CRC32 checksum. Before the monitor 2599is relocated into RAM, as a result of a bad CRC you will be working 2600with the compiled-in default environment - *silently*!!! [This is 2601necessary, because the first environment variable we need is the 2602"baudrate" setting for the console - if we have a bad CRC, we don't 2603have any device yet where we could complain.] 2604 2605Note: once the monitor has been relocated, then it will complain if 2606the default environment is used; a new CRC is computed as soon as you 2607use the "saveenv" command to store a valid environment. 2608 2609- CONFIG_SYS_FAULT_ECHO_LINK_DOWN: 2610 Echo the inverted Ethernet link state to the fault LED. 2611 2612 Note: If this option is active, then CONFIG_SYS_FAULT_MII_ADDR 2613 also needs to be defined. 2614 2615- CONFIG_SYS_FAULT_MII_ADDR: 2616 MII address of the PHY to check for the Ethernet link state. 2617 2618- CONFIG_NS16550_MIN_FUNCTIONS: 2619 Define this if you desire to only have use of the NS16550_init 2620 and NS16550_putc functions for the serial driver located at 2621 drivers/serial/ns16550.c. This option is useful for saving 2622 space for already greatly restricted images, including but not 2623 limited to NAND_SPL configurations. 2624 2625Low Level (hardware related) configuration options: 2626--------------------------------------------------- 2627 2628- CONFIG_SYS_CACHELINE_SIZE: 2629 Cache Line Size of the CPU. 2630 2631- CONFIG_SYS_DEFAULT_IMMR: 2632 Default address of the IMMR after system reset. 2633 2634 Needed on some 8260 systems (MPC8260ADS, PQ2FADS-ZU, 2635 and RPXsuper) to be able to adjust the position of 2636 the IMMR register after a reset. 2637 2638- Floppy Disk Support: 2639 CONFIG_SYS_FDC_DRIVE_NUMBER 2640 2641 the default drive number (default value 0) 2642 2643 CONFIG_SYS_ISA_IO_STRIDE 2644 2645 defines the spacing between FDC chipset registers 2646 (default value 1) 2647 2648 CONFIG_SYS_ISA_IO_OFFSET 2649 2650 defines the offset of register from address. It 2651 depends on which part of the data bus is connected to 2652 the FDC chipset. (default value 0) 2653 2654 If CONFIG_SYS_ISA_IO_STRIDE CONFIG_SYS_ISA_IO_OFFSET and 2655 CONFIG_SYS_FDC_DRIVE_NUMBER are undefined, they take their 2656 default value. 2657 2658 if CONFIG_SYS_FDC_HW_INIT is defined, then the function 2659 fdc_hw_init() is called at the beginning of the FDC 2660 setup. fdc_hw_init() must be provided by the board 2661 source code. It is used to make hardware dependant 2662 initializations. 2663 2664- CONFIG_SYS_IMMR: Physical address of the Internal Memory. 2665 DO NOT CHANGE unless you know exactly what you're 2666 doing! (11-4) [MPC8xx/82xx systems only] 2667 2668- CONFIG_SYS_INIT_RAM_ADDR: 2669 2670 Start address of memory area that can be used for 2671 initial data and stack; please note that this must be 2672 writable memory that is working WITHOUT special 2673 initialization, i. e. you CANNOT use normal RAM which 2674 will become available only after programming the 2675 memory controller and running certain initialization 2676 sequences. 2677 2678 U-Boot uses the following memory types: 2679 - MPC8xx and MPC8260: IMMR (internal memory of the CPU) 2680 - MPC824X: data cache 2681 - PPC4xx: data cache 2682 2683- CONFIG_SYS_GBL_DATA_OFFSET: 2684 2685 Offset of the initial data structure in the memory 2686 area defined by CONFIG_SYS_INIT_RAM_ADDR. Usually 2687 CONFIG_SYS_GBL_DATA_OFFSET is chosen such that the initial 2688 data is located at the end of the available space 2689 (sometimes written as (CONFIG_SYS_INIT_RAM_SIZE - 2690 CONFIG_SYS_INIT_DATA_SIZE), and the initial stack is just 2691 below that area (growing from (CONFIG_SYS_INIT_RAM_ADDR + 2692 CONFIG_SYS_GBL_DATA_OFFSET) downward. 2693 2694 Note: 2695 On the MPC824X (or other systems that use the data 2696 cache for initial memory) the address chosen for 2697 CONFIG_SYS_INIT_RAM_ADDR is basically arbitrary - it must 2698 point to an otherwise UNUSED address space between 2699 the top of RAM and the start of the PCI space. 2700 2701- CONFIG_SYS_SIUMCR: SIU Module Configuration (11-6) 2702 2703- CONFIG_SYS_SYPCR: System Protection Control (11-9) 2704 2705- CONFIG_SYS_TBSCR: Time Base Status and Control (11-26) 2706 2707- CONFIG_SYS_PISCR: Periodic Interrupt Status and Control (11-31) 2708 2709- CONFIG_SYS_PLPRCR: PLL, Low-Power, and Reset Control Register (15-30) 2710 2711- CONFIG_SYS_SCCR: System Clock and reset Control Register (15-27) 2712 2713- CONFIG_SYS_OR_TIMING_SDRAM: 2714 SDRAM timing 2715 2716- CONFIG_SYS_MAMR_PTA: 2717 periodic timer for refresh 2718 2719- CONFIG_SYS_DER: Debug Event Register (37-47) 2720 2721- FLASH_BASE0_PRELIM, FLASH_BASE1_PRELIM, CONFIG_SYS_REMAP_OR_AM, 2722 CONFIG_SYS_PRELIM_OR_AM, CONFIG_SYS_OR_TIMING_FLASH, CONFIG_SYS_OR0_REMAP, 2723 CONFIG_SYS_OR0_PRELIM, CONFIG_SYS_BR0_PRELIM, CONFIG_SYS_OR1_REMAP, CONFIG_SYS_OR1_PRELIM, 2724 CONFIG_SYS_BR1_PRELIM: 2725 Memory Controller Definitions: BR0/1 and OR0/1 (FLASH) 2726 2727- SDRAM_BASE2_PRELIM, SDRAM_BASE3_PRELIM, SDRAM_MAX_SIZE, 2728 CONFIG_SYS_OR_TIMING_SDRAM, CONFIG_SYS_OR2_PRELIM, CONFIG_SYS_BR2_PRELIM, 2729 CONFIG_SYS_OR3_PRELIM, CONFIG_SYS_BR3_PRELIM: 2730 Memory Controller Definitions: BR2/3 and OR2/3 (SDRAM) 2731 2732- CONFIG_SYS_MAMR_PTA, CONFIG_SYS_MPTPR_2BK_4K, CONFIG_SYS_MPTPR_1BK_4K, CONFIG_SYS_MPTPR_2BK_8K, 2733 CONFIG_SYS_MPTPR_1BK_8K, CONFIG_SYS_MAMR_8COL, CONFIG_SYS_MAMR_9COL: 2734 Machine Mode Register and Memory Periodic Timer 2735 Prescaler definitions (SDRAM timing) 2736 2737- CONFIG_SYS_I2C_UCODE_PATCH, CONFIG_SYS_I2C_DPMEM_OFFSET [0x1FC0]: 2738 enable I2C microcode relocation patch (MPC8xx); 2739 define relocation offset in DPRAM [DSP2] 2740 2741- CONFIG_SYS_SMC_UCODE_PATCH, CONFIG_SYS_SMC_DPMEM_OFFSET [0x1FC0]: 2742 enable SMC microcode relocation patch (MPC8xx); 2743 define relocation offset in DPRAM [SMC1] 2744 2745- CONFIG_SYS_SPI_UCODE_PATCH, CONFIG_SYS_SPI_DPMEM_OFFSET [0x1FC0]: 2746 enable SPI microcode relocation patch (MPC8xx); 2747 define relocation offset in DPRAM [SCC4] 2748 2749- CONFIG_SYS_USE_OSCCLK: 2750 Use OSCM clock mode on MBX8xx board. Be careful, 2751 wrong setting might damage your board. Read 2752 doc/README.MBX before setting this variable! 2753 2754- CONFIG_SYS_CPM_POST_WORD_ADDR: (MPC8xx, MPC8260 only) 2755 Offset of the bootmode word in DPRAM used by post 2756 (Power On Self Tests). This definition overrides 2757 #define'd default value in commproc.h resp. 2758 cpm_8260.h. 2759 2760- CONFIG_SYS_PCI_SLV_MEM_LOCAL, CONFIG_SYS_PCI_SLV_MEM_BUS, CONFIG_SYS_PICMR0_MASK_ATTRIB, 2761 CONFIG_SYS_PCI_MSTR0_LOCAL, CONFIG_SYS_PCIMSK0_MASK, CONFIG_SYS_PCI_MSTR1_LOCAL, 2762 CONFIG_SYS_PCIMSK1_MASK, CONFIG_SYS_PCI_MSTR_MEM_LOCAL, CONFIG_SYS_PCI_MSTR_MEM_BUS, 2763 CONFIG_SYS_CPU_PCI_MEM_START, CONFIG_SYS_PCI_MSTR_MEM_SIZE, CONFIG_SYS_POCMR0_MASK_ATTRIB, 2764 CONFIG_SYS_PCI_MSTR_MEMIO_LOCAL, CONFIG_SYS_PCI_MSTR_MEMIO_BUS, CPU_PCI_MEMIO_START, 2765 CONFIG_SYS_PCI_MSTR_MEMIO_SIZE, CONFIG_SYS_POCMR1_MASK_ATTRIB, CONFIG_SYS_PCI_MSTR_IO_LOCAL, 2766 CONFIG_SYS_PCI_MSTR_IO_BUS, CONFIG_SYS_CPU_PCI_IO_START, CONFIG_SYS_PCI_MSTR_IO_SIZE, 2767 CONFIG_SYS_POCMR2_MASK_ATTRIB: (MPC826x only) 2768 Overrides the default PCI memory map in arch/powerpc/cpu/mpc8260/pci.c if set. 2769 2770- CONFIG_PCI_DISABLE_PCIE: 2771 Disable PCI-Express on systems where it is supported but not 2772 required. 2773 2774- CONFIG_SPD_EEPROM 2775 Get DDR timing information from an I2C EEPROM. Common 2776 with pluggable memory modules such as SODIMMs 2777 2778 SPD_EEPROM_ADDRESS 2779 I2C address of the SPD EEPROM 2780 2781- CONFIG_SYS_SPD_BUS_NUM 2782 If SPD EEPROM is on an I2C bus other than the first 2783 one, specify here. Note that the value must resolve 2784 to something your driver can deal with. 2785 2786- CONFIG_SYS_83XX_DDR_USES_CS0 2787 Only for 83xx systems. If specified, then DDR should 2788 be configured using CS0 and CS1 instead of CS2 and CS3. 2789 2790- CONFIG_ETHER_ON_FEC[12] 2791 Define to enable FEC[12] on a 8xx series processor. 2792 2793- CONFIG_FEC[12]_PHY 2794 Define to the hardcoded PHY address which corresponds 2795 to the given FEC; i. e. 2796 #define CONFIG_FEC1_PHY 4 2797 means that the PHY with address 4 is connected to FEC1 2798 2799 When set to -1, means to probe for first available. 2800 2801- CONFIG_FEC[12]_PHY_NORXERR 2802 The PHY does not have a RXERR line (RMII only). 2803 (so program the FEC to ignore it). 2804 2805- CONFIG_RMII 2806 Enable RMII mode for all FECs. 2807 Note that this is a global option, we can't 2808 have one FEC in standard MII mode and another in RMII mode. 2809 2810- CONFIG_CRC32_VERIFY 2811 Add a verify option to the crc32 command. 2812 The syntax is: 2813 2814 => crc32 -v <address> <count> <crc32> 2815 2816 Where address/count indicate a memory area 2817 and crc32 is the correct crc32 which the 2818 area should have. 2819 2820- CONFIG_LOOPW 2821 Add the "loopw" memory command. This only takes effect if 2822 the memory commands are activated globally (CONFIG_CMD_MEM). 2823 2824- CONFIG_MX_CYCLIC 2825 Add the "mdc" and "mwc" memory commands. These are cyclic 2826 "md/mw" commands. 2827 Examples: 2828 2829 => mdc.b 10 4 500 2830 This command will print 4 bytes (10,11,12,13) each 500 ms. 2831 2832 => mwc.l 100 12345678 10 2833 This command will write 12345678 to address 100 all 10 ms. 2834 2835 This only takes effect if the memory commands are activated 2836 globally (CONFIG_CMD_MEM). 2837 2838- CONFIG_SKIP_LOWLEVEL_INIT 2839 [ARM only] If this variable is defined, then certain 2840 low level initializations (like setting up the memory 2841 controller) are omitted and/or U-Boot does not 2842 relocate itself into RAM. 2843 2844 Normally this variable MUST NOT be defined. The only 2845 exception is when U-Boot is loaded (to RAM) by some 2846 other boot loader or by a debugger which performs 2847 these initializations itself. 2848 2849- CONFIG_PRELOADER 2850 Modifies the behaviour of start.S when compiling a loader 2851 that is executed before the actual U-Boot. E.g. when 2852 compiling a NAND SPL. 2853 2854Building the Software: 2855====================== 2856 2857Building U-Boot has been tested in several native build environments 2858and in many different cross environments. Of course we cannot support 2859all possibly existing versions of cross development tools in all 2860(potentially obsolete) versions. In case of tool chain problems we 2861recommend to use the ELDK (see http://www.denx.de/wiki/DULG/ELDK) 2862which is extensively used to build and test U-Boot. 2863 2864If you are not using a native environment, it is assumed that you 2865have GNU cross compiling tools available in your path. In this case, 2866you must set the environment variable CROSS_COMPILE in your shell. 2867Note that no changes to the Makefile or any other source files are 2868necessary. For example using the ELDK on a 4xx CPU, please enter: 2869 2870 $ CROSS_COMPILE=ppc_4xx- 2871 $ export CROSS_COMPILE 2872 2873Note: If you wish to generate Windows versions of the utilities in 2874 the tools directory you can use the MinGW toolchain 2875 (http://www.mingw.org). Set your HOST tools to the MinGW 2876 toolchain and execute 'make tools'. For example: 2877 2878 $ make HOSTCC=i586-mingw32msvc-gcc HOSTSTRIP=i586-mingw32msvc-strip tools 2879 2880 Binaries such as tools/mkimage.exe will be created which can 2881 be executed on computers running Windows. 2882 2883U-Boot is intended to be simple to build. After installing the 2884sources you must configure U-Boot for one specific board type. This 2885is done by typing: 2886 2887 make NAME_config 2888 2889where "NAME_config" is the name of one of the existing configu- 2890rations; see the main Makefile for supported names. 2891 2892Note: for some board special configuration names may exist; check if 2893 additional information is available from the board vendor; for 2894 instance, the TQM823L systems are available without (standard) 2895 or with LCD support. You can select such additional "features" 2896 when choosing the configuration, i. e. 2897 2898 make TQM823L_config 2899 - will configure for a plain TQM823L, i. e. no LCD support 2900 2901 make TQM823L_LCD_config 2902 - will configure for a TQM823L with U-Boot console on LCD 2903 2904 etc. 2905 2906 2907Finally, type "make all", and you should get some working U-Boot 2908images ready for download to / installation on your system: 2909 2910- "u-boot.bin" is a raw binary image 2911- "u-boot" is an image in ELF binary format 2912- "u-boot.srec" is in Motorola S-Record format 2913 2914By default the build is performed locally and the objects are saved 2915in the source directory. One of the two methods can be used to change 2916this behavior and build U-Boot to some external directory: 2917 29181. Add O= to the make command line invocations: 2919 2920 make O=/tmp/build distclean 2921 make O=/tmp/build NAME_config 2922 make O=/tmp/build all 2923 29242. Set environment variable BUILD_DIR to point to the desired location: 2925 2926 export BUILD_DIR=/tmp/build 2927 make distclean 2928 make NAME_config 2929 make all 2930 2931Note that the command line "O=" setting overrides the BUILD_DIR environment 2932variable. 2933 2934 2935Please be aware that the Makefiles assume you are using GNU make, so 2936for instance on NetBSD you might need to use "gmake" instead of 2937native "make". 2938 2939 2940If the system board that you have is not listed, then you will need 2941to port U-Boot to your hardware platform. To do this, follow these 2942steps: 2943 29441. Add a new configuration option for your board to the toplevel 2945 "Makefile" and to the "MAKEALL" script, using the existing 2946 entries as examples. Note that here and at many other places 2947 boards and other names are listed in alphabetical sort order. Please 2948 keep this order. 29492. Create a new directory to hold your board specific code. Add any 2950 files you need. In your board directory, you will need at least 2951 the "Makefile", a "<board>.c", "flash.c" and "u-boot.lds". 29523. Create a new configuration file "include/configs/<board>.h" for 2953 your board 29543. If you're porting U-Boot to a new CPU, then also create a new 2955 directory to hold your CPU specific code. Add any files you need. 29564. Run "make <board>_config" with your new name. 29575. Type "make", and you should get a working "u-boot.srec" file 2958 to be installed on your target system. 29596. Debug and solve any problems that might arise. 2960 [Of course, this last step is much harder than it sounds.] 2961 2962 2963Testing of U-Boot Modifications, Ports to New Hardware, etc.: 2964============================================================== 2965 2966If you have modified U-Boot sources (for instance added a new board 2967or support for new devices, a new CPU, etc.) you are expected to 2968provide feedback to the other developers. The feedback normally takes 2969the form of a "patch", i. e. a context diff against a certain (latest 2970official or latest in the git repository) version of U-Boot sources. 2971 2972But before you submit such a patch, please verify that your modifi- 2973cation did not break existing code. At least make sure that *ALL* of 2974the supported boards compile WITHOUT ANY compiler warnings. To do so, 2975just run the "MAKEALL" script, which will configure and build U-Boot 2976for ALL supported system. Be warned, this will take a while. You can 2977select which (cross) compiler to use by passing a `CROSS_COMPILE' 2978environment variable to the script, i. e. to use the ELDK cross tools 2979you can type 2980 2981 CROSS_COMPILE=ppc_8xx- MAKEALL 2982 2983or to build on a native PowerPC system you can type 2984 2985 CROSS_COMPILE=' ' MAKEALL 2986 2987When using the MAKEALL script, the default behaviour is to build 2988U-Boot in the source directory. This location can be changed by 2989setting the BUILD_DIR environment variable. Also, for each target 2990built, the MAKEALL script saves two log files (<target>.ERR and 2991<target>.MAKEALL) in the <source dir>/LOG directory. This default 2992location can be changed by setting the MAKEALL_LOGDIR environment 2993variable. For example: 2994 2995 export BUILD_DIR=/tmp/build 2996 export MAKEALL_LOGDIR=/tmp/log 2997 CROSS_COMPILE=ppc_8xx- MAKEALL 2998 2999With the above settings build objects are saved in the /tmp/build, 3000log files are saved in the /tmp/log and the source tree remains clean 3001during the whole build process. 3002 3003 3004See also "U-Boot Porting Guide" below. 3005 3006 3007Monitor Commands - Overview: 3008============================ 3009 3010go - start application at address 'addr' 3011run - run commands in an environment variable 3012bootm - boot application image from memory 3013bootp - boot image via network using BootP/TFTP protocol 3014tftpboot- boot image via network using TFTP protocol 3015 and env variables "ipaddr" and "serverip" 3016 (and eventually "gatewayip") 3017rarpboot- boot image via network using RARP/TFTP protocol 3018diskboot- boot from IDE devicebootd - boot default, i.e., run 'bootcmd' 3019loads - load S-Record file over serial line 3020loadb - load binary file over serial line (kermit mode) 3021md - memory display 3022mm - memory modify (auto-incrementing) 3023nm - memory modify (constant address) 3024mw - memory write (fill) 3025cp - memory copy 3026cmp - memory compare 3027crc32 - checksum calculation 3028i2c - I2C sub-system 3029sspi - SPI utility commands 3030base - print or set address offset 3031printenv- print environment variables 3032setenv - set environment variables 3033saveenv - save environment variables to persistent storage 3034protect - enable or disable FLASH write protection 3035erase - erase FLASH memory 3036flinfo - print FLASH memory information 3037bdinfo - print Board Info structure 3038iminfo - print header information for application image 3039coninfo - print console devices and informations 3040ide - IDE sub-system 3041loop - infinite loop on address range 3042loopw - infinite write loop on address range 3043mtest - simple RAM test 3044icache - enable or disable instruction cache 3045dcache - enable or disable data cache 3046reset - Perform RESET of the CPU 3047echo - echo args to console 3048version - print monitor version 3049help - print online help 3050? - alias for 'help' 3051 3052 3053Monitor Commands - Detailed Description: 3054======================================== 3055 3056TODO. 3057 3058For now: just type "help <command>". 3059 3060 3061Environment Variables: 3062====================== 3063 3064U-Boot supports user configuration using Environment Variables which 3065can be made persistent by saving to Flash memory. 3066 3067Environment Variables are set using "setenv", printed using 3068"printenv", and saved to Flash using "saveenv". Using "setenv" 3069without a value can be used to delete a variable from the 3070environment. As long as you don't save the environment you are 3071working with an in-memory copy. In case the Flash area containing the 3072environment is erased by accident, a default environment is provided. 3073 3074Some configuration options can be set using Environment Variables. 3075 3076List of environment variables (most likely not complete): 3077 3078 baudrate - see CONFIG_BAUDRATE 3079 3080 bootdelay - see CONFIG_BOOTDELAY 3081 3082 bootcmd - see CONFIG_BOOTCOMMAND 3083 3084 bootargs - Boot arguments when booting an RTOS image 3085 3086 bootfile - Name of the image to load with TFTP 3087 3088 bootm_low - Memory range available for image processing in the bootm 3089 command can be restricted. This variable is given as 3090 a hexadecimal number and defines lowest address allowed 3091 for use by the bootm command. See also "bootm_size" 3092 environment variable. Address defined by "bootm_low" is 3093 also the base of the initial memory mapping for the Linux 3094 kernel -- see the description of CONFIG_SYS_BOOTMAPSZ. 3095 3096 bootm_size - Memory range available for image processing in the bootm 3097 command can be restricted. This variable is given as 3098 a hexadecimal number and defines the size of the region 3099 allowed for use by the bootm command. See also "bootm_low" 3100 environment variable. 3101 3102 updatefile - Location of the software update file on a TFTP server, used 3103 by the automatic software update feature. Please refer to 3104 documentation in doc/README.update for more details. 3105 3106 autoload - if set to "no" (any string beginning with 'n'), 3107 "bootp" will just load perform a lookup of the 3108 configuration from the BOOTP server, but not try to 3109 load any image using TFTP 3110 3111 autostart - if set to "yes", an image loaded using the "bootp", 3112 "rarpboot", "tftpboot" or "diskboot" commands will 3113 be automatically started (by internally calling 3114 "bootm") 3115 3116 If set to "no", a standalone image passed to the 3117 "bootm" command will be copied to the load address 3118 (and eventually uncompressed), but NOT be started. 3119 This can be used to load and uncompress arbitrary 3120 data. 3121 3122 i2cfast - (PPC405GP|PPC405EP only) 3123 if set to 'y' configures Linux I2C driver for fast 3124 mode (400kHZ). This environment variable is used in 3125 initialization code. So, for changes to be effective 3126 it must be saved and board must be reset. 3127 3128 initrd_high - restrict positioning of initrd images: 3129 If this variable is not set, initrd images will be 3130 copied to the highest possible address in RAM; this 3131 is usually what you want since it allows for 3132 maximum initrd size. If for some reason you want to 3133 make sure that the initrd image is loaded below the 3134 CONFIG_SYS_BOOTMAPSZ limit, you can set this environment 3135 variable to a value of "no" or "off" or "0". 3136 Alternatively, you can set it to a maximum upper 3137 address to use (U-Boot will still check that it 3138 does not overwrite the U-Boot stack and data). 3139 3140 For instance, when you have a system with 16 MB 3141 RAM, and want to reserve 4 MB from use by Linux, 3142 you can do this by adding "mem=12M" to the value of 3143 the "bootargs" variable. However, now you must make 3144 sure that the initrd image is placed in the first 3145 12 MB as well - this can be done with 3146 3147 setenv initrd_high 00c00000 3148 3149 If you set initrd_high to 0xFFFFFFFF, this is an 3150 indication to U-Boot that all addresses are legal 3151 for the Linux kernel, including addresses in flash 3152 memory. In this case U-Boot will NOT COPY the 3153 ramdisk at all. This may be useful to reduce the 3154 boot time on your system, but requires that this 3155 feature is supported by your Linux kernel. 3156 3157 ipaddr - IP address; needed for tftpboot command 3158 3159 loadaddr - Default load address for commands like "bootp", 3160 "rarpboot", "tftpboot", "loadb" or "diskboot" 3161 3162 loads_echo - see CONFIG_LOADS_ECHO 3163 3164 serverip - TFTP server IP address; needed for tftpboot command 3165 3166 bootretry - see CONFIG_BOOT_RETRY_TIME 3167 3168 bootdelaykey - see CONFIG_AUTOBOOT_DELAY_STR 3169 3170 bootstopkey - see CONFIG_AUTOBOOT_STOP_STR 3171 3172 ethprime - When CONFIG_NET_MULTI is enabled controls which 3173 interface is used first. 3174 3175 ethact - When CONFIG_NET_MULTI is enabled controls which 3176 interface is currently active. For example you 3177 can do the following 3178 3179 => setenv ethact FEC 3180 => ping 192.168.0.1 # traffic sent on FEC 3181 => setenv ethact SCC 3182 => ping 10.0.0.1 # traffic sent on SCC 3183 3184 ethrotate - When set to "no" U-Boot does not go through all 3185 available network interfaces. 3186 It just stays at the currently selected interface. 3187 3188 netretry - When set to "no" each network operation will 3189 either succeed or fail without retrying. 3190 When set to "once" the network operation will 3191 fail when all the available network interfaces 3192 are tried once without success. 3193 Useful on scripts which control the retry operation 3194 themselves. 3195 3196 npe_ucode - set load address for the NPE microcode 3197 3198 tftpsrcport - If this is set, the value is used for TFTP's 3199 UDP source port. 3200 3201 tftpdstport - If this is set, the value is used for TFTP's UDP 3202 destination port instead of the Well Know Port 69. 3203 3204 tftpblocksize - Block size to use for TFTP transfers; if not set, 3205 we use the TFTP server's default block size 3206 3207 tftptimeout - Retransmission timeout for TFTP packets (in milli- 3208 seconds, minimum value is 1000 = 1 second). Defines 3209 when a packet is considered to be lost so it has to 3210 be retransmitted. The default is 5000 = 5 seconds. 3211 Lowering this value may make downloads succeed 3212 faster in networks with high packet loss rates or 3213 with unreliable TFTP servers. 3214 3215 vlan - When set to a value < 4095 the traffic over 3216 Ethernet is encapsulated/received over 802.1q 3217 VLAN tagged frames. 3218 3219The following environment variables may be used and automatically 3220updated by the network boot commands ("bootp" and "rarpboot"), 3221depending the information provided by your boot server: 3222 3223 bootfile - see above 3224 dnsip - IP address of your Domain Name Server 3225 dnsip2 - IP address of your secondary Domain Name Server 3226 gatewayip - IP address of the Gateway (Router) to use 3227 hostname - Target hostname 3228 ipaddr - see above 3229 netmask - Subnet Mask 3230 rootpath - Pathname of the root filesystem on the NFS server 3231 serverip - see above 3232 3233 3234There are two special Environment Variables: 3235 3236 serial# - contains hardware identification information such 3237 as type string and/or serial number 3238 ethaddr - Ethernet address 3239 3240These variables can be set only once (usually during manufacturing of 3241the board). U-Boot refuses to delete or overwrite these variables 3242once they have been set once. 3243 3244 3245Further special Environment Variables: 3246 3247 ver - Contains the U-Boot version string as printed 3248 with the "version" command. This variable is 3249 readonly (see CONFIG_VERSION_VARIABLE). 3250 3251 3252Please note that changes to some configuration parameters may take 3253only effect after the next boot (yes, that's just like Windoze :-). 3254 3255 3256Command Line Parsing: 3257===================== 3258 3259There are two different command line parsers available with U-Boot: 3260the old "simple" one, and the much more powerful "hush" shell: 3261 3262Old, simple command line parser: 3263-------------------------------- 3264 3265- supports environment variables (through setenv / saveenv commands) 3266- several commands on one line, separated by ';' 3267- variable substitution using "... ${name} ..." syntax 3268- special characters ('$', ';') can be escaped by prefixing with '\', 3269 for example: 3270 setenv bootcmd bootm \${address} 3271- You can also escape text by enclosing in single apostrophes, for example: 3272 setenv addip 'setenv bootargs $bootargs ip=$ipaddr:$serverip:$gatewayip:$netmask:$hostname::off' 3273 3274Hush shell: 3275----------- 3276 3277- similar to Bourne shell, with control structures like 3278 if...then...else...fi, for...do...done; while...do...done, 3279 until...do...done, ... 3280- supports environment ("global") variables (through setenv / saveenv 3281 commands) and local shell variables (through standard shell syntax 3282 "name=value"); only environment variables can be used with "run" 3283 command 3284 3285General rules: 3286-------------- 3287 3288(1) If a command line (or an environment variable executed by a "run" 3289 command) contains several commands separated by semicolon, and 3290 one of these commands fails, then the remaining commands will be 3291 executed anyway. 3292 3293(2) If you execute several variables with one call to run (i. e. 3294 calling run with a list of variables as arguments), any failing 3295 command will cause "run" to terminate, i. e. the remaining 3296 variables are not executed. 3297 3298Note for Redundant Ethernet Interfaces: 3299======================================= 3300 3301Some boards come with redundant Ethernet interfaces; U-Boot supports 3302such configurations and is capable of automatic selection of a 3303"working" interface when needed. MAC assignment works as follows: 3304 3305Network interfaces are numbered eth0, eth1, eth2, ... Corresponding 3306MAC addresses can be stored in the environment as "ethaddr" (=>eth0), 3307"eth1addr" (=>eth1), "eth2addr", ... 3308 3309If the network interface stores some valid MAC address (for instance 3310in SROM), this is used as default address if there is NO correspon- 3311ding setting in the environment; if the corresponding environment 3312variable is set, this overrides the settings in the card; that means: 3313 3314o If the SROM has a valid MAC address, and there is no address in the 3315 environment, the SROM's address is used. 3316 3317o If there is no valid address in the SROM, and a definition in the 3318 environment exists, then the value from the environment variable is 3319 used. 3320 3321o If both the SROM and the environment contain a MAC address, and 3322 both addresses are the same, this MAC address is used. 3323 3324o If both the SROM and the environment contain a MAC address, and the 3325 addresses differ, the value from the environment is used and a 3326 warning is printed. 3327 3328o If neither SROM nor the environment contain a MAC address, an error 3329 is raised. 3330 3331If Ethernet drivers implement the 'write_hwaddr' function, valid MAC addresses 3332will be programmed into hardware as part of the initialization process. This 3333may be skipped by setting the appropriate 'ethmacskip' environment variable. 3334The naming convention is as follows: 3335"ethmacskip" (=>eth0), "eth1macskip" (=>eth1) etc. 3336 3337Image Formats: 3338============== 3339 3340U-Boot is capable of booting (and performing other auxiliary operations on) 3341images in two formats: 3342 3343New uImage format (FIT) 3344----------------------- 3345 3346Flexible and powerful format based on Flattened Image Tree -- FIT (similar 3347to Flattened Device Tree). It allows the use of images with multiple 3348components (several kernels, ramdisks, etc.), with contents protected by 3349SHA1, MD5 or CRC32. More details are found in the doc/uImage.FIT directory. 3350 3351 3352Old uImage format 3353----------------- 3354 3355Old image format is based on binary files which can be basically anything, 3356preceded by a special header; see the definitions in include/image.h for 3357details; basically, the header defines the following image properties: 3358 3359* Target Operating System (Provisions for OpenBSD, NetBSD, FreeBSD, 3360 4.4BSD, Linux, SVR4, Esix, Solaris, Irix, SCO, Dell, NCR, VxWorks, 3361 LynxOS, pSOS, QNX, RTEMS, INTEGRITY; 3362 Currently supported: Linux, NetBSD, VxWorks, QNX, RTEMS, LynxOS, 3363 INTEGRITY). 3364* Target CPU Architecture (Provisions for Alpha, ARM, AVR32, Intel x86, 3365 IA64, MIPS, Nios II, PowerPC, IBM S390, SuperH, Sparc, Sparc 64 Bit; 3366 Currently supported: ARM, AVR32, Intel x86, MIPS, Nios II, PowerPC). 3367* Compression Type (uncompressed, gzip, bzip2) 3368* Load Address 3369* Entry Point 3370* Image Name 3371* Image Timestamp 3372 3373The header is marked by a special Magic Number, and both the header 3374and the data portions of the image are secured against corruption by 3375CRC32 checksums. 3376 3377 3378Linux Support: 3379============== 3380 3381Although U-Boot should support any OS or standalone application 3382easily, the main focus has always been on Linux during the design of 3383U-Boot. 3384 3385U-Boot includes many features that so far have been part of some 3386special "boot loader" code within the Linux kernel. Also, any 3387"initrd" images to be used are no longer part of one big Linux image; 3388instead, kernel and "initrd" are separate images. This implementation 3389serves several purposes: 3390 3391- the same features can be used for other OS or standalone 3392 applications (for instance: using compressed images to reduce the 3393 Flash memory footprint) 3394 3395- it becomes much easier to port new Linux kernel versions because 3396 lots of low-level, hardware dependent stuff are done by U-Boot 3397 3398- the same Linux kernel image can now be used with different "initrd" 3399 images; of course this also means that different kernel images can 3400 be run with the same "initrd". This makes testing easier (you don't 3401 have to build a new "zImage.initrd" Linux image when you just 3402 change a file in your "initrd"). Also, a field-upgrade of the 3403 software is easier now. 3404 3405 3406Linux HOWTO: 3407============ 3408 3409Porting Linux to U-Boot based systems: 3410--------------------------------------- 3411 3412U-Boot cannot save you from doing all the necessary modifications to 3413configure the Linux device drivers for use with your target hardware 3414(no, we don't intend to provide a full virtual machine interface to 3415Linux :-). 3416 3417But now you can ignore ALL boot loader code (in arch/powerpc/mbxboot). 3418 3419Just make sure your machine specific header file (for instance 3420include/asm-ppc/tqm8xx.h) includes the same definition of the Board 3421Information structure as we define in include/asm-<arch>/u-boot.h, 3422and make sure that your definition of IMAP_ADDR uses the same value 3423as your U-Boot configuration in CONFIG_SYS_IMMR. 3424 3425 3426Configuring the Linux kernel: 3427----------------------------- 3428 3429No specific requirements for U-Boot. Make sure you have some root 3430device (initial ramdisk, NFS) for your target system. 3431 3432 3433Building a Linux Image: 3434----------------------- 3435 3436With U-Boot, "normal" build targets like "zImage" or "bzImage" are 3437not used. If you use recent kernel source, a new build target 3438"uImage" will exist which automatically builds an image usable by 3439U-Boot. Most older kernels also have support for a "pImage" target, 3440which was introduced for our predecessor project PPCBoot and uses a 3441100% compatible format. 3442 3443Example: 3444 3445 make TQM850L_config 3446 make oldconfig 3447 make dep 3448 make uImage 3449 3450The "uImage" build target uses a special tool (in 'tools/mkimage') to 3451encapsulate a compressed Linux kernel image with header information, 3452CRC32 checksum etc. for use with U-Boot. This is what we are doing: 3453 3454* build a standard "vmlinux" kernel image (in ELF binary format): 3455 3456* convert the kernel into a raw binary image: 3457 3458 ${CROSS_COMPILE}-objcopy -O binary \ 3459 -R .note -R .comment \ 3460 -S vmlinux linux.bin 3461 3462* compress the binary image: 3463 3464 gzip -9 linux.bin 3465 3466* package compressed binary image for U-Boot: 3467 3468 mkimage -A ppc -O linux -T kernel -C gzip \ 3469 -a 0 -e 0 -n "Linux Kernel Image" \ 3470 -d linux.bin.gz uImage 3471 3472 3473The "mkimage" tool can also be used to create ramdisk images for use 3474with U-Boot, either separated from the Linux kernel image, or 3475combined into one file. "mkimage" encapsulates the images with a 64 3476byte header containing information about target architecture, 3477operating system, image type, compression method, entry points, time 3478stamp, CRC32 checksums, etc. 3479 3480"mkimage" can be called in two ways: to verify existing images and 3481print the header information, or to build new images. 3482 3483In the first form (with "-l" option) mkimage lists the information 3484contained in the header of an existing U-Boot image; this includes 3485checksum verification: 3486 3487 tools/mkimage -l image 3488 -l ==> list image header information 3489 3490The second form (with "-d" option) is used to build a U-Boot image 3491from a "data file" which is used as image payload: 3492 3493 tools/mkimage -A arch -O os -T type -C comp -a addr -e ep \ 3494 -n name -d data_file image 3495 -A ==> set architecture to 'arch' 3496 -O ==> set operating system to 'os' 3497 -T ==> set image type to 'type' 3498 -C ==> set compression type 'comp' 3499 -a ==> set load address to 'addr' (hex) 3500 -e ==> set entry point to 'ep' (hex) 3501 -n ==> set image name to 'name' 3502 -d ==> use image data from 'datafile' 3503 3504Right now, all Linux kernels for PowerPC systems use the same load 3505address (0x00000000), but the entry point address depends on the 3506kernel version: 3507 3508- 2.2.x kernels have the entry point at 0x0000000C, 3509- 2.3.x and later kernels have the entry point at 0x00000000. 3510 3511So a typical call to build a U-Boot image would read: 3512 3513 -> tools/mkimage -n '2.4.4 kernel for TQM850L' \ 3514 > -A ppc -O linux -T kernel -C gzip -a 0 -e 0 \ 3515 > -d /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/powerpc/coffboot/vmlinux.gz \ 3516 > examples/uImage.TQM850L 3517 Image Name: 2.4.4 kernel for TQM850L 3518 Created: Wed Jul 19 02:34:59 2000 3519 Image Type: PowerPC Linux Kernel Image (gzip compressed) 3520 Data Size: 335725 Bytes = 327.86 kB = 0.32 MB 3521 Load Address: 0x00000000 3522 Entry Point: 0x00000000 3523 3524To verify the contents of the image (or check for corruption): 3525 3526 -> tools/mkimage -l examples/uImage.TQM850L 3527 Image Name: 2.4.4 kernel for TQM850L 3528 Created: Wed Jul 19 02:34:59 2000 3529 Image Type: PowerPC Linux Kernel Image (gzip compressed) 3530 Data Size: 335725 Bytes = 327.86 kB = 0.32 MB 3531 Load Address: 0x00000000 3532 Entry Point: 0x00000000 3533 3534NOTE: for embedded systems where boot time is critical you can trade 3535speed for memory and install an UNCOMPRESSED image instead: this 3536needs more space in Flash, but boots much faster since it does not 3537need to be uncompressed: 3538 3539 -> gunzip /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/powerpc/coffboot/vmlinux.gz 3540 -> tools/mkimage -n '2.4.4 kernel for TQM850L' \ 3541 > -A ppc -O linux -T kernel -C none -a 0 -e 0 \ 3542 > -d /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/powerpc/coffboot/vmlinux \ 3543 > examples/uImage.TQM850L-uncompressed 3544 Image Name: 2.4.4 kernel for TQM850L 3545 Created: Wed Jul 19 02:34:59 2000 3546 Image Type: PowerPC Linux Kernel Image (uncompressed) 3547 Data Size: 792160 Bytes = 773.59 kB = 0.76 MB 3548 Load Address: 0x00000000 3549 Entry Point: 0x00000000 3550 3551 3552Similar you can build U-Boot images from a 'ramdisk.image.gz' file 3553when your kernel is intended to use an initial ramdisk: 3554 3555 -> tools/mkimage -n 'Simple Ramdisk Image' \ 3556 > -A ppc -O linux -T ramdisk -C gzip \ 3557 > -d /LinuxPPC/images/SIMPLE-ramdisk.image.gz examples/simple-initrd 3558 Image Name: Simple Ramdisk Image 3559 Created: Wed Jan 12 14:01:50 2000 3560 Image Type: PowerPC Linux RAMDisk Image (gzip compressed) 3561 Data Size: 566530 Bytes = 553.25 kB = 0.54 MB 3562 Load Address: 0x00000000 3563 Entry Point: 0x00000000 3564 3565 3566Installing a Linux Image: 3567------------------------- 3568 3569To downloading a U-Boot image over the serial (console) interface, 3570you must convert the image to S-Record format: 3571 3572 objcopy -I binary -O srec examples/image examples/image.srec 3573 3574The 'objcopy' does not understand the information in the U-Boot 3575image header, so the resulting S-Record file will be relative to 3576address 0x00000000. To load it to a given address, you need to 3577specify the target address as 'offset' parameter with the 'loads' 3578command. 3579 3580Example: install the image to address 0x40100000 (which on the 3581TQM8xxL is in the first Flash bank): 3582 3583 => erase 40100000 401FFFFF 3584 3585 .......... done 3586 Erased 8 sectors 3587 3588 => loads 40100000 3589 ## Ready for S-Record download ... 3590 ~>examples/image.srec 3591 1 2 3 4 5 6 7 8 9 10 11 12 13 ... 3592 ... 3593 15989 15990 15991 15992 3594 [file transfer complete] 3595 [connected] 3596 ## Start Addr = 0x00000000 3597 3598 3599You can check the success of the download using the 'iminfo' command; 3600this includes a checksum verification so you can be sure no data 3601corruption happened: 3602 3603 => imi 40100000 3604 3605 ## Checking Image at 40100000 ... 3606 Image Name: 2.2.13 for initrd on TQM850L 3607 Image Type: PowerPC Linux Kernel Image (gzip compressed) 3608 Data Size: 335725 Bytes = 327 kB = 0 MB 3609 Load Address: 00000000 3610 Entry Point: 0000000c 3611 Verifying Checksum ... OK 3612 3613 3614Boot Linux: 3615----------- 3616 3617The "bootm" command is used to boot an application that is stored in 3618memory (RAM or Flash). In case of a Linux kernel image, the contents 3619of the "bootargs" environment variable is passed to the kernel as 3620parameters. You can check and modify this variable using the 3621"printenv" and "setenv" commands: 3622 3623 3624 => printenv bootargs 3625 bootargs=root=/dev/ram 3626 3627 => setenv bootargs root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2 3628 3629 => printenv bootargs 3630 bootargs=root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2 3631 3632 => bootm 40020000 3633 ## Booting Linux kernel at 40020000 ... 3634 Image Name: 2.2.13 for NFS on TQM850L 3635 Image Type: PowerPC Linux Kernel Image (gzip compressed) 3636 Data Size: 381681 Bytes = 372 kB = 0 MB 3637 Load Address: 00000000 3638 Entry Point: 0000000c 3639 Verifying Checksum ... OK 3640 Uncompressing Kernel Image ... OK 3641 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 3642 Boot arguments: root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2 3643 time_init: decrementer frequency = 187500000/60 3644 Calibrating delay loop... 49.77 BogoMIPS 3645 Memory: 15208k available (700k kernel code, 444k data, 32k init) [c0000000,c1000000] 3646 ... 3647 3648If you want to boot a Linux kernel with initial RAM disk, you pass 3649the memory addresses of both the kernel and the initrd image (PPBCOOT 3650format!) to the "bootm" command: 3651 3652 => imi 40100000 40200000 3653 3654 ## Checking Image at 40100000 ... 3655 Image Name: 2.2.13 for initrd on TQM850L 3656 Image Type: PowerPC Linux Kernel Image (gzip compressed) 3657 Data Size: 335725 Bytes = 327 kB = 0 MB 3658 Load Address: 00000000 3659 Entry Point: 0000000c 3660 Verifying Checksum ... OK 3661 3662 ## Checking Image at 40200000 ... 3663 Image Name: Simple Ramdisk Image 3664 Image Type: PowerPC Linux RAMDisk Image (gzip compressed) 3665 Data Size: 566530 Bytes = 553 kB = 0 MB 3666 Load Address: 00000000 3667 Entry Point: 00000000 3668 Verifying Checksum ... OK 3669 3670 => bootm 40100000 40200000 3671 ## Booting Linux kernel at 40100000 ... 3672 Image Name: 2.2.13 for initrd on TQM850L 3673 Image Type: PowerPC Linux Kernel Image (gzip compressed) 3674 Data Size: 335725 Bytes = 327 kB = 0 MB 3675 Load Address: 00000000 3676 Entry Point: 0000000c 3677 Verifying Checksum ... OK 3678 Uncompressing Kernel Image ... OK 3679 ## Loading RAMDisk Image at 40200000 ... 3680 Image Name: Simple Ramdisk Image 3681 Image Type: PowerPC Linux RAMDisk Image (gzip compressed) 3682 Data Size: 566530 Bytes = 553 kB = 0 MB 3683 Load Address: 00000000 3684 Entry Point: 00000000 3685 Verifying Checksum ... OK 3686 Loading Ramdisk ... OK 3687 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 3688 Boot arguments: root=/dev/ram 3689 time_init: decrementer frequency = 187500000/60 3690 Calibrating delay loop... 49.77 BogoMIPS 3691 ... 3692 RAMDISK: Compressed image found at block 0 3693 VFS: Mounted root (ext2 filesystem). 3694 3695 bash# 3696 3697Boot Linux and pass a flat device tree: 3698----------- 3699 3700First, U-Boot must be compiled with the appropriate defines. See the section 3701titled "Linux Kernel Interface" above for a more in depth explanation. The 3702following is an example of how to start a kernel and pass an updated 3703flat device tree: 3704 3705=> print oftaddr 3706oftaddr=0x300000 3707=> print oft 3708oft=oftrees/mpc8540ads.dtb 3709=> tftp $oftaddr $oft 3710Speed: 1000, full duplex 3711Using TSEC0 device 3712TFTP from server 192.168.1.1; our IP address is 192.168.1.101 3713Filename 'oftrees/mpc8540ads.dtb'. 3714Load address: 0x300000 3715Loading: # 3716done 3717Bytes transferred = 4106 (100a hex) 3718=> tftp $loadaddr $bootfile 3719Speed: 1000, full duplex 3720Using TSEC0 device 3721TFTP from server 192.168.1.1; our IP address is 192.168.1.2 3722Filename 'uImage'. 3723Load address: 0x200000 3724Loading:############ 3725done 3726Bytes transferred = 1029407 (fb51f hex) 3727=> print loadaddr 3728loadaddr=200000 3729=> print oftaddr 3730oftaddr=0x300000 3731=> bootm $loadaddr - $oftaddr 3732## Booting image at 00200000 ... 3733 Image Name: Linux-2.6.17-dirty 3734 Image Type: PowerPC Linux Kernel Image (gzip compressed) 3735 Data Size: 1029343 Bytes = 1005.2 kB 3736 Load Address: 00000000 3737 Entry Point: 00000000 3738 Verifying Checksum ... OK 3739 Uncompressing Kernel Image ... OK 3740Booting using flat device tree at 0x300000 3741Using MPC85xx ADS machine description 3742Memory CAM mapping: CAM0=256Mb, CAM1=256Mb, CAM2=0Mb residual: 0Mb 3743[snip] 3744 3745 3746More About U-Boot Image Types: 3747------------------------------ 3748 3749U-Boot supports the following image types: 3750 3751 "Standalone Programs" are directly runnable in the environment 3752 provided by U-Boot; it is expected that (if they behave 3753 well) you can continue to work in U-Boot after return from 3754 the Standalone Program. 3755 "OS Kernel Images" are usually images of some Embedded OS which 3756 will take over control completely. Usually these programs 3757 will install their own set of exception handlers, device 3758 drivers, set up the MMU, etc. - this means, that you cannot 3759 expect to re-enter U-Boot except by resetting the CPU. 3760 "RAMDisk Images" are more or less just data blocks, and their 3761 parameters (address, size) are passed to an OS kernel that is 3762 being started. 3763 "Multi-File Images" contain several images, typically an OS 3764 (Linux) kernel image and one or more data images like 3765 RAMDisks. This construct is useful for instance when you want 3766 to boot over the network using BOOTP etc., where the boot 3767 server provides just a single image file, but you want to get 3768 for instance an OS kernel and a RAMDisk image. 3769 3770 "Multi-File Images" start with a list of image sizes, each 3771 image size (in bytes) specified by an "uint32_t" in network 3772 byte order. This list is terminated by an "(uint32_t)0". 3773 Immediately after the terminating 0 follow the images, one by 3774 one, all aligned on "uint32_t" boundaries (size rounded up to 3775 a multiple of 4 bytes). 3776 3777 "Firmware Images" are binary images containing firmware (like 3778 U-Boot or FPGA images) which usually will be programmed to 3779 flash memory. 3780 3781 "Script files" are command sequences that will be executed by 3782 U-Boot's command interpreter; this feature is especially 3783 useful when you configure U-Boot to use a real shell (hush) 3784 as command interpreter. 3785 3786 3787Standalone HOWTO: 3788================= 3789 3790One of the features of U-Boot is that you can dynamically load and 3791run "standalone" applications, which can use some resources of 3792U-Boot like console I/O functions or interrupt services. 3793 3794Two simple examples are included with the sources: 3795 3796"Hello World" Demo: 3797------------------- 3798 3799'examples/hello_world.c' contains a small "Hello World" Demo 3800application; it is automatically compiled when you build U-Boot. 3801It's configured to run at address 0x00040004, so you can play with it 3802like that: 3803 3804 => loads 3805 ## Ready for S-Record download ... 3806 ~>examples/hello_world.srec 3807 1 2 3 4 5 6 7 8 9 10 11 ... 3808 [file transfer complete] 3809 [connected] 3810 ## Start Addr = 0x00040004 3811 3812 => go 40004 Hello World! This is a test. 3813 ## Starting application at 0x00040004 ... 3814 Hello World 3815 argc = 7 3816 argv[0] = "40004" 3817 argv[1] = "Hello" 3818 argv[2] = "World!" 3819 argv[3] = "This" 3820 argv[4] = "is" 3821 argv[5] = "a" 3822 argv[6] = "test." 3823 argv[7] = "<NULL>" 3824 Hit any key to exit ... 3825 3826 ## Application terminated, rc = 0x0 3827 3828Another example, which demonstrates how to register a CPM interrupt 3829handler with the U-Boot code, can be found in 'examples/timer.c'. 3830Here, a CPM timer is set up to generate an interrupt every second. 3831The interrupt service routine is trivial, just printing a '.' 3832character, but this is just a demo program. The application can be 3833controlled by the following keys: 3834 3835 ? - print current values og the CPM Timer registers 3836 b - enable interrupts and start timer 3837 e - stop timer and disable interrupts 3838 q - quit application 3839 3840 => loads 3841 ## Ready for S-Record download ... 3842 ~>examples/timer.srec 3843 1 2 3 4 5 6 7 8 9 10 11 ... 3844 [file transfer complete] 3845 [connected] 3846 ## Start Addr = 0x00040004 3847 3848 => go 40004 3849 ## Starting application at 0x00040004 ... 3850 TIMERS=0xfff00980 3851 Using timer 1 3852 tgcr @ 0xfff00980, tmr @ 0xfff00990, trr @ 0xfff00994, tcr @ 0xfff00998, tcn @ 0xfff0099c, ter @ 0xfff009b0 3853 3854Hit 'b': 3855 [q, b, e, ?] Set interval 1000000 us 3856 Enabling timer 3857Hit '?': 3858 [q, b, e, ?] ........ 3859 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0xef6, ter=0x0 3860Hit '?': 3861 [q, b, e, ?] . 3862 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x2ad4, ter=0x0 3863Hit '?': 3864 [q, b, e, ?] . 3865 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x1efc, ter=0x0 3866Hit '?': 3867 [q, b, e, ?] . 3868 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x169d, ter=0x0 3869Hit 'e': 3870 [q, b, e, ?] ...Stopping timer 3871Hit 'q': 3872 [q, b, e, ?] ## Application terminated, rc = 0x0 3873 3874 3875Minicom warning: 3876================ 3877 3878Over time, many people have reported problems when trying to use the 3879"minicom" terminal emulation program for serial download. I (wd) 3880consider minicom to be broken, and recommend not to use it. Under 3881Unix, I recommend to use C-Kermit for general purpose use (and 3882especially for kermit binary protocol download ("loadb" command), and 3883use "cu" for S-Record download ("loads" command). 3884 3885Nevertheless, if you absolutely want to use it try adding this 3886configuration to your "File transfer protocols" section: 3887 3888 Name Program Name U/D FullScr IO-Red. Multi 3889 X kermit /usr/bin/kermit -i -l %l -s Y U Y N N 3890 Y kermit /usr/bin/kermit -i -l %l -r N D Y N N 3891 3892 3893NetBSD Notes: 3894============= 3895 3896Starting at version 0.9.2, U-Boot supports NetBSD both as host 3897(build U-Boot) and target system (boots NetBSD/mpc8xx). 3898 3899Building requires a cross environment; it is known to work on 3900NetBSD/i386 with the cross-powerpc-netbsd-1.3 package (you will also 3901need gmake since the Makefiles are not compatible with BSD make). 3902Note that the cross-powerpc package does not install include files; 3903attempting to build U-Boot will fail because <machine/ansi.h> is 3904missing. This file has to be installed and patched manually: 3905 3906 # cd /usr/pkg/cross/powerpc-netbsd/include 3907 # mkdir powerpc 3908 # ln -s powerpc machine 3909 # cp /usr/src/sys/arch/powerpc/include/ansi.h powerpc/ansi.h 3910 # ${EDIT} powerpc/ansi.h ## must remove __va_list, _BSD_VA_LIST 3911 3912Native builds *don't* work due to incompatibilities between native 3913and U-Boot include files. 3914 3915Booting assumes that (the first part of) the image booted is a 3916stage-2 loader which in turn loads and then invokes the kernel 3917proper. Loader sources will eventually appear in the NetBSD source 3918tree (probably in sys/arc/mpc8xx/stand/u-boot_stage2/); in the 3919meantime, see ftp://ftp.denx.de/pub/u-boot/ppcboot_stage2.tar.gz 3920 3921 3922Implementation Internals: 3923========================= 3924 3925The following is not intended to be a complete description of every 3926implementation detail. However, it should help to understand the 3927inner workings of U-Boot and make it easier to port it to custom 3928hardware. 3929 3930 3931Initial Stack, Global Data: 3932--------------------------- 3933 3934The implementation of U-Boot is complicated by the fact that U-Boot 3935starts running out of ROM (flash memory), usually without access to 3936system RAM (because the memory controller is not initialized yet). 3937This means that we don't have writable Data or BSS segments, and BSS 3938is not initialized as zero. To be able to get a C environment working 3939at all, we have to allocate at least a minimal stack. Implementation 3940options for this are defined and restricted by the CPU used: Some CPU 3941models provide on-chip memory (like the IMMR area on MPC8xx and 3942MPC826x processors), on others (parts of) the data cache can be 3943locked as (mis-) used as memory, etc. 3944 3945 Chris Hallinan posted a good summary of these issues to the 3946 U-Boot mailing list: 3947 3948 Subject: RE: [U-Boot-Users] RE: More On Memory Bank x (nothingness)? 3949 From: "Chris Hallinan" <clh@net1plus.com> 3950 Date: Mon, 10 Feb 2003 16:43:46 -0500 (22:43 MET) 3951 ... 3952 3953 Correct me if I'm wrong, folks, but the way I understand it 3954 is this: Using DCACHE as initial RAM for Stack, etc, does not 3955 require any physical RAM backing up the cache. The cleverness 3956 is that the cache is being used as a temporary supply of 3957 necessary storage before the SDRAM controller is setup. It's 3958 beyond the scope of this list to explain the details, but you 3959 can see how this works by studying the cache architecture and 3960 operation in the architecture and processor-specific manuals. 3961 3962 OCM is On Chip Memory, which I believe the 405GP has 4K. It 3963 is another option for the system designer to use as an 3964 initial stack/RAM area prior to SDRAM being available. Either 3965 option should work for you. Using CS 4 should be fine if your 3966 board designers haven't used it for something that would 3967 cause you grief during the initial boot! It is frequently not 3968 used. 3969 3970 CONFIG_SYS_INIT_RAM_ADDR should be somewhere that won't interfere 3971 with your processor/board/system design. The default value 3972 you will find in any recent u-boot distribution in 3973 walnut.h should work for you. I'd set it to a value larger 3974 than your SDRAM module. If you have a 64MB SDRAM module, set 3975 it above 400_0000. Just make sure your board has no resources 3976 that are supposed to respond to that address! That code in 3977 start.S has been around a while and should work as is when 3978 you get the config right. 3979 3980 -Chris Hallinan 3981 DS4.COM, Inc. 3982 3983It is essential to remember this, since it has some impact on the C 3984code for the initialization procedures: 3985 3986* Initialized global data (data segment) is read-only. Do not attempt 3987 to write it. 3988 3989* Do not use any uninitialized global data (or implicitely initialized 3990 as zero data - BSS segment) at all - this is undefined, initiali- 3991 zation is performed later (when relocating to RAM). 3992 3993* Stack space is very limited. Avoid big data buffers or things like 3994 that. 3995 3996Having only the stack as writable memory limits means we cannot use 3997normal global data to share information beween the code. But it 3998turned out that the implementation of U-Boot can be greatly 3999simplified by making a global data structure (gd_t) available to all 4000functions. We could pass a pointer to this data as argument to _all_ 4001functions, but this would bloat the code. Instead we use a feature of 4002the GCC compiler (Global Register Variables) to share the data: we 4003place a pointer (gd) to the global data into a register which we 4004reserve for this purpose. 4005 4006When choosing a register for such a purpose we are restricted by the 4007relevant (E)ABI specifications for the current architecture, and by 4008GCC's implementation. 4009 4010For PowerPC, the following registers have specific use: 4011 R1: stack pointer 4012 R2: reserved for system use 4013 R3-R4: parameter passing and return values 4014 R5-R10: parameter passing 4015 R13: small data area pointer 4016 R30: GOT pointer 4017 R31: frame pointer 4018 4019 (U-Boot also uses R12 as internal GOT pointer. r12 4020 is a volatile register so r12 needs to be reset when 4021 going back and forth between asm and C) 4022 4023 ==> U-Boot will use R2 to hold a pointer to the global data 4024 4025 Note: on PPC, we could use a static initializer (since the 4026 address of the global data structure is known at compile time), 4027 but it turned out that reserving a register results in somewhat 4028 smaller code - although the code savings are not that big (on 4029 average for all boards 752 bytes for the whole U-Boot image, 4030 624 text + 127 data). 4031 4032On Blackfin, the normal C ABI (except for P3) is followed as documented here: 4033 http://docs.blackfin.uclinux.org/doku.php?id=application_binary_interface 4034 4035 ==> U-Boot will use P3 to hold a pointer to the global data 4036 4037On ARM, the following registers are used: 4038 4039 R0: function argument word/integer result 4040 R1-R3: function argument word 4041 R9: GOT pointer 4042 R10: stack limit (used only if stack checking if enabled) 4043 R11: argument (frame) pointer 4044 R12: temporary workspace 4045 R13: stack pointer 4046 R14: link register 4047 R15: program counter 4048 4049 ==> U-Boot will use R8 to hold a pointer to the global data 4050 4051On Nios II, the ABI is documented here: 4052 http://www.altera.com/literature/hb/nios2/n2cpu_nii51016.pdf 4053 4054 ==> U-Boot will use gp to hold a pointer to the global data 4055 4056 Note: on Nios II, we give "-G0" option to gcc and don't use gp 4057 to access small data sections, so gp is free. 4058 4059NOTE: DECLARE_GLOBAL_DATA_PTR must be used with file-global scope, 4060or current versions of GCC may "optimize" the code too much. 4061 4062Memory Management: 4063------------------ 4064 4065U-Boot runs in system state and uses physical addresses, i.e. the 4066MMU is not used either for address mapping nor for memory protection. 4067 4068The available memory is mapped to fixed addresses using the memory 4069controller. In this process, a contiguous block is formed for each 4070memory type (Flash, SDRAM, SRAM), even when it consists of several 4071physical memory banks. 4072 4073U-Boot is installed in the first 128 kB of the first Flash bank (on 4074TQM8xxL modules this is the range 0x40000000 ... 0x4001FFFF). After 4075booting and sizing and initializing DRAM, the code relocates itself 4076to the upper end of DRAM. Immediately below the U-Boot code some 4077memory is reserved for use by malloc() [see CONFIG_SYS_MALLOC_LEN 4078configuration setting]. Below that, a structure with global Board 4079Info data is placed, followed by the stack (growing downward). 4080 4081Additionally, some exception handler code is copied to the low 8 kB 4082of DRAM (0x00000000 ... 0x00001FFF). 4083 4084So a typical memory configuration with 16 MB of DRAM could look like 4085this: 4086 4087 0x0000 0000 Exception Vector code 4088 : 4089 0x0000 1FFF 4090 0x0000 2000 Free for Application Use 4091 : 4092 : 4093 4094 : 4095 : 4096 0x00FB FF20 Monitor Stack (Growing downward) 4097 0x00FB FFAC Board Info Data and permanent copy of global data 4098 0x00FC 0000 Malloc Arena 4099 : 4100 0x00FD FFFF 4101 0x00FE 0000 RAM Copy of Monitor Code 4102 ... eventually: LCD or video framebuffer 4103 ... eventually: pRAM (Protected RAM - unchanged by reset) 4104 0x00FF FFFF [End of RAM] 4105 4106 4107System Initialization: 4108---------------------- 4109 4110In the reset configuration, U-Boot starts at the reset entry point 4111(on most PowerPC systems at address 0x00000100). Because of the reset 4112configuration for CS0# this is a mirror of the onboard Flash memory. 4113To be able to re-map memory U-Boot then jumps to its link address. 4114To be able to implement the initialization code in C, a (small!) 4115initial stack is set up in the internal Dual Ported RAM (in case CPUs 4116which provide such a feature like MPC8xx or MPC8260), or in a locked 4117part of the data cache. After that, U-Boot initializes the CPU core, 4118the caches and the SIU. 4119 4120Next, all (potentially) available memory banks are mapped using a 4121preliminary mapping. For example, we put them on 512 MB boundaries 4122(multiples of 0x20000000: SDRAM on 0x00000000 and 0x20000000, Flash 4123on 0x40000000 and 0x60000000, SRAM on 0x80000000). Then UPM A is 4124programmed for SDRAM access. Using the temporary configuration, a 4125simple memory test is run that determines the size of the SDRAM 4126banks. 4127 4128When there is more than one SDRAM bank, and the banks are of 4129different size, the largest is mapped first. For equal size, the first 4130bank (CS2#) is mapped first. The first mapping is always for address 41310x00000000, with any additional banks following immediately to create 4132contiguous memory starting from 0. 4133 4134Then, the monitor installs itself at the upper end of the SDRAM area 4135and allocates memory for use by malloc() and for the global Board 4136Info data; also, the exception vector code is copied to the low RAM 4137pages, and the final stack is set up. 4138 4139Only after this relocation will you have a "normal" C environment; 4140until that you are restricted in several ways, mostly because you are 4141running from ROM, and because the code will have to be relocated to a 4142new address in RAM. 4143 4144 4145U-Boot Porting Guide: 4146---------------------- 4147 4148[Based on messages by Jerry Van Baren in the U-Boot-Users mailing 4149list, October 2002] 4150 4151 4152int main(int argc, char *argv[]) 4153{ 4154 sighandler_t no_more_time; 4155 4156 signal(SIGALRM, no_more_time); 4157 alarm(PROJECT_DEADLINE - toSec (3 * WEEK)); 4158 4159 if (available_money > available_manpower) { 4160 Pay consultant to port U-Boot; 4161 return 0; 4162 } 4163 4164 Download latest U-Boot source; 4165 4166 Subscribe to u-boot mailing list; 4167 4168 if (clueless) 4169 email("Hi, I am new to U-Boot, how do I get started?"); 4170 4171 while (learning) { 4172 Read the README file in the top level directory; 4173 Read http://www.denx.de/twiki/bin/view/DULG/Manual; 4174 Read applicable doc/*.README; 4175 Read the source, Luke; 4176 /* find . -name "*.[chS]" | xargs grep -i <keyword> */ 4177 } 4178 4179 if (available_money > toLocalCurrency ($2500)) 4180 Buy a BDI3000; 4181 else 4182 Add a lot of aggravation and time; 4183 4184 if (a similar board exists) { /* hopefully... */ 4185 cp -a board/<similar> board/<myboard> 4186 cp include/configs/<similar>.h include/configs/<myboard>.h 4187 } else { 4188 Create your own board support subdirectory; 4189 Create your own board include/configs/<myboard>.h file; 4190 } 4191 Edit new board/<myboard> files 4192 Edit new include/configs/<myboard>.h 4193 4194 while (!accepted) { 4195 while (!running) { 4196 do { 4197 Add / modify source code; 4198 } until (compiles); 4199 Debug; 4200 if (clueless) 4201 email("Hi, I am having problems..."); 4202 } 4203 Send patch file to the U-Boot email list; 4204 if (reasonable critiques) 4205 Incorporate improvements from email list code review; 4206 else 4207 Defend code as written; 4208 } 4209 4210 return 0; 4211} 4212 4213void no_more_time (int sig) 4214{ 4215 hire_a_guru(); 4216} 4217 4218 4219Coding Standards: 4220----------------- 4221 4222All contributions to U-Boot should conform to the Linux kernel 4223coding style; see the file "Documentation/CodingStyle" and the script 4224"scripts/Lindent" in your Linux kernel source directory. In sources 4225originating from U-Boot a style corresponding to "Lindent -pcs" (adding 4226spaces before parameters to function calls) is actually used. 4227 4228Source files originating from a different project (for example the 4229MTD subsystem) are generally exempt from these guidelines and are not 4230reformated to ease subsequent migration to newer versions of those 4231sources. 4232 4233Please note that U-Boot is implemented in C (and to some small parts in 4234Assembler); no C++ is used, so please do not use C++ style comments (//) 4235in your code. 4236 4237Please also stick to the following formatting rules: 4238- remove any trailing white space 4239- use TAB characters for indentation, not spaces 4240- make sure NOT to use DOS '\r\n' line feeds 4241- do not add more than 2 empty lines to source files 4242- do not add trailing empty lines to source files 4243 4244Submissions which do not conform to the standards may be returned 4245with a request to reformat the changes. 4246 4247 4248Submitting Patches: 4249------------------- 4250 4251Since the number of patches for U-Boot is growing, we need to 4252establish some rules. Submissions which do not conform to these rules 4253may be rejected, even when they contain important and valuable stuff. 4254 4255Please see http://www.denx.de/wiki/U-Boot/Patches for details. 4256 4257Patches shall be sent to the u-boot mailing list <u-boot@lists.denx.de>; 4258see http://lists.denx.de/mailman/listinfo/u-boot 4259 4260When you send a patch, please include the following information with 4261it: 4262 4263* For bug fixes: a description of the bug and how your patch fixes 4264 this bug. Please try to include a way of demonstrating that the 4265 patch actually fixes something. 4266 4267* For new features: a description of the feature and your 4268 implementation. 4269 4270* A CHANGELOG entry as plaintext (separate from the patch) 4271 4272* For major contributions, your entry to the CREDITS file 4273 4274* When you add support for a new board, don't forget to add this 4275 board to the MAKEALL script, too. 4276 4277* If your patch adds new configuration options, don't forget to 4278 document these in the README file. 4279 4280* The patch itself. If you are using git (which is *strongly* 4281 recommended) you can easily generate the patch using the 4282 "git-format-patch". If you then use "git-send-email" to send it to 4283 the U-Boot mailing list, you will avoid most of the common problems 4284 with some other mail clients. 4285 4286 If you cannot use git, use "diff -purN OLD NEW". If your version of 4287 diff does not support these options, then get the latest version of 4288 GNU diff. 4289 4290 The current directory when running this command shall be the parent 4291 directory of the U-Boot source tree (i. e. please make sure that 4292 your patch includes sufficient directory information for the 4293 affected files). 4294 4295 We prefer patches as plain text. MIME attachments are discouraged, 4296 and compressed attachments must not be used. 4297 4298* If one logical set of modifications affects or creates several 4299 files, all these changes shall be submitted in a SINGLE patch file. 4300 4301* Changesets that contain different, unrelated modifications shall be 4302 submitted as SEPARATE patches, one patch per changeset. 4303 4304 4305Notes: 4306 4307* Before sending the patch, run the MAKEALL script on your patched 4308 source tree and make sure that no errors or warnings are reported 4309 for any of the boards. 4310 4311* Keep your modifications to the necessary minimum: A patch 4312 containing several unrelated changes or arbitrary reformats will be 4313 returned with a request to re-formatting / split it. 4314 4315* If you modify existing code, make sure that your new code does not 4316 add to the memory footprint of the code ;-) Small is beautiful! 4317 When adding new features, these should compile conditionally only 4318 (using #ifdef), and the resulting code with the new feature 4319 disabled must not need more memory than the old code without your 4320 modification. 4321 4322* Remember that there is a size limit of 100 kB per message on the 4323 u-boot mailing list. Bigger patches will be moderated. If they are 4324 reasonable and not too big, they will be acknowledged. But patches 4325 bigger than the size limit should be avoided. 4326