1# 2# (C) Copyright 2000 - 2002 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 and ARM processors, which can be 29installed in a boot ROM and used to initialize and test the hardware 30or to download and run application code. 31 32The development of U-Boot is closely related to Linux: some parts of 33the source code originate in the Linux source tree, we have some 34header files in common, and special provision has been made to 35support booting of Linux images. 36 37Some attention has been paid to make this software easily 38configurable and extendable. For instance, all monitor commands are 39implemented with the same call interface, so that it's very easy to 40add new commands. Also, instead of permanently adding rarely used 41code (for instance hardware test utilities) to the monitor, you can 42load and run it dynamically. 43 44 45Status: 46======= 47 48In general, all boards for which a configuration option exists in the 49Makefile have been tested to some extent and can be considered 50"working". In fact, many of them are used in production systems. 51 52In case of problems see the CHANGELOG and CREDITS files to find out 53who contributed the specific port. 54 55 56Where to get help: 57================== 58 59In case you have questions about, problems with or contributions for 60U-Boot you should send a message to the U-Boot mailing list at 61<u-boot-users@lists.sourceforge.net>. There is also an archive of 62previous traffic on the mailing list - please search the archive 63before asking FAQ's. Please see 64http://lists.sourceforge.net/lists/listinfo/u-boot-users/ 65 66 67Where we come from: 68=================== 69 70- start from 8xxrom sources 71- create PPCBoot project (http://sourceforge.net/projects/ppcboot) 72- clean up code 73- make it easier to add custom boards 74- make it possible to add other [PowerPC] CPUs 75- extend functions, especially: 76 * Provide extended interface to Linux boot loader 77 * S-Record download 78 * network boot 79 * PCMCIA / CompactFLash / ATA disk / SCSI ... boot 80- create ARMBoot project (http://sourceforge.net/projects/armboot) 81- add other CPU families (starting with ARM) 82- create U-Boot project (http://sourceforge.net/projects/u-boot) 83 84 85Names and Spelling: 86=================== 87 88The "official" name of this project is "Das U-Boot". The spelling 89"U-Boot" shall be used in all written text (documentation, comments 90in source files etc.). Example: 91 92 This is the README file for the U-Boot project. 93 94File names etc. shall be based on the string "u-boot". Examples: 95 96 include/asm-ppc/u-boot.h 97 98 #include <asm/u-boot.h> 99 100Variable names, preprocessor constants etc. shall be either based on 101the string "u_boot" or on "U_BOOT". Example: 102 103 U_BOOT_VERSION u_boot_logo 104 IH_OS_U_BOOT u_boot_hush_start 105 106 107Versioning: 108=========== 109 110U-Boot uses a 3 level version number containing a version, a 111sub-version, and a patchlevel: "U-Boot-2.34.5" means version "2", 112sub-version "34", and patchlevel "4". 113 114The patchlevel is used to indicate certain stages of development 115between released versions, i. e. officially released versions of 116U-Boot will always have a patchlevel of "0". 117 118 119Directory Hierarchy: 120==================== 121 122- board Board dependent files 123- common Misc architecture independent functions 124- cpu CPU specific files 125- disk Code for disk drive partition handling 126- doc Documentation (don't expect too much) 127- drivers Commonly used device drivers 128- dtt Digital Thermometer and Thermostat drivers 129- examples Example code for standalone applications, etc. 130- include Header Files 131- disk Harddisk interface code 132- net Networking code 133- ppc Files generic to PowerPC architecture 134- post Power On Self Test 135- post/arch Symlink to architecture specific Power On Self Test 136- post/arch-ppc PowerPC architecture specific Power On Self Test 137- post/cpu/mpc8260 MPC8260 CPU specific Power On Self Test 138- post/cpu/mpc8xx MPC8xx CPU specific Power On Self Test 139- rtc Real Time Clock drivers 140- tools Tools to build S-Record or U-Boot images, etc. 141 142- cpu/74xx_7xx Files specific to Motorola MPC74xx and 7xx CPUs 143- cpu/arm925t Files specific to ARM 925 CPUs 144- cpu/arm926ejs Files specific to ARM 926 CPUs 145- cpu/mpc5xx Files specific to Motorola MPC5xx CPUs 146- cpu/mpc8xx Files specific to Motorola MPC8xx CPUs 147- cpu/mpc824x Files specific to Motorola MPC824x CPUs 148- cpu/mpc8260 Files specific to Motorola MPC8260 CPU 149- cpu/mpc85xx Files specific to Motorola MPC85xx CPUs 150- cpu/ppc4xx Files specific to IBM 4xx CPUs 151 152 153- board/LEOX/ Files specific to boards manufactured by The LEOX team 154- board/LEOX/elpt860 Files specific to ELPT860 boards 155- board/RPXClassic 156 Files specific to RPXClassic boards 157- board/RPXlite Files specific to RPXlite boards 158- board/at91rm9200dk Files specific to AT91RM9200DK boards 159- board/c2mon Files specific to c2mon boards 160- board/cmi Files specific to cmi boards 161- board/cogent Files specific to Cogent boards 162 (need further configuration) 163 Files specific to CPCIISER4 boards 164- board/cpu86 Files specific to CPU86 boards 165- board/cray/ Files specific to boards manufactured by Cray 166- board/cray/L1 Files specific to L1 boards 167- board/cu824 Files specific to CU824 boards 168- board/ebony Files specific to IBM Ebony board 169- board/eric Files specific to ERIC boards 170- board/esd/ Files specific to boards manufactured by ESD 171- board/esd/adciop Files specific to ADCIOP boards 172- board/esd/ar405 Files specific to AR405 boards 173- board/esd/canbt Files specific to CANBT boards 174- board/esd/cpci405 Files specific to CPCI405 boards 175- board/esd/cpciiser4 Files specific to CPCIISER4 boards 176- board/esd/common Common files for ESD boards 177- board/esd/dasa_sim Files specific to DASA_SIM boards 178- board/esd/du405 Files specific to DU405 boards 179- board/esd/ocrtc Files specific to OCRTC boards 180- board/esd/pci405 Files specific to PCI405 boards 181- board/esteem192e 182 Files specific to ESTEEM192E boards 183- board/etx094 Files specific to ETX_094 boards 184- board/evb64260 185 Files specific to EVB64260 boards 186- board/fads Files specific to FADS boards 187- board/flagadm Files specific to FLAGADM boards 188- board/gen860t Files specific to GEN860T and GEN860T_SC boards 189- board/genietv Files specific to GENIETV boards 190- board/gth Files specific to GTH boards 191- board/hermes Files specific to HERMES boards 192- board/hymod Files specific to HYMOD boards 193- board/icu862 Files specific to ICU862 boards 194- board/ip860 Files specific to IP860 boards 195- board/iphase4539 196 Files specific to Interphase4539 boards 197- board/ivm Files specific to IVMS8/IVML24 boards 198- board/lantec Files specific to LANTEC boards 199- board/lwmon Files specific to LWMON boards 200- board/mbx8xx Files specific to MBX boards 201- board/mpc8260ads 202 Files specific to MPC8260ADS and PQ2FADS-ZU boards 203- board/mpc8540ads 204 Files specific to MPC8540ADS boards 205- board/mpc8560ads 206 Files specific to MPC8560ADS boards 207- board/mpl/ Files specific to boards manufactured by MPL 208- board/mpl/common Common files for MPL boards 209- board/mpl/pip405 Files specific to PIP405 boards 210- board/mpl/mip405 Files specific to MIP405 boards 211- board/mpl/vcma9 Files specific to VCMA9 boards 212- board/musenki Files specific to MUSEKNI boards 213- board/mvs1 Files specific to MVS1 boards 214- board/nx823 Files specific to NX823 boards 215- board/oxc Files specific to OXC boards 216- board/omap1510inn 217 Files specific to OMAP 1510 Innovator boards 218- board/omap1610inn 219 Files specific to OMAP 1610 Innovator boards 220- board/pcippc2 Files specific to PCIPPC2/PCIPPC6 boards 221- board/pm826 Files specific to PM826 boards 222- board/ppmc8260 223 Files specific to PPMC8260 boards 224- board/rpxsuper 225 Files specific to RPXsuper boards 226- board/rsdproto 227 Files specific to RSDproto boards 228- board/sandpoint 229 Files specific to Sandpoint boards 230- board/sbc8260 Files specific to SBC8260 boards 231- board/sacsng Files specific to SACSng boards 232- board/siemens Files specific to boards manufactured by Siemens AG 233- board/siemens/CCM Files specific to CCM boards 234- board/siemens/IAD210 Files specific to IAD210 boards 235- board/siemens/SCM Files specific to SCM boards 236- board/siemens/pcu_e Files specific to PCU_E boards 237- board/sixnet Files specific to SIXNET boards 238- board/spd8xx Files specific to SPD8xxTS boards 239- board/tqm8260 Files specific to TQM8260 boards 240- board/tqm8xx Files specific to TQM8xxL boards 241- board/w7o Files specific to W7O boards 242- board/walnut405 243 Files specific to Walnut405 boards 244- board/westel/ Files specific to boards manufactured by Westel Wireless 245- board/westel/amx860 Files specific to AMX860 boards 246- board/utx8245 Files specific to UTX8245 boards 247- board/zpc1900 Files specific to Zephyr Engineering ZPC.1900 board 248 249Software Configuration: 250======================= 251 252Configuration is usually done using C preprocessor defines; the 253rationale behind that is to avoid dead code whenever possible. 254 255There are two classes of configuration variables: 256 257* Configuration _OPTIONS_: 258 These are selectable by the user and have names beginning with 259 "CONFIG_". 260 261* Configuration _SETTINGS_: 262 These depend on the hardware etc. and should not be meddled with if 263 you don't know what you're doing; they have names beginning with 264 "CFG_". 265 266Later we will add a configuration tool - probably similar to or even 267identical to what's used for the Linux kernel. Right now, we have to 268do the configuration by hand, which means creating some symbolic 269links and editing some configuration files. We use the TQM8xxL boards 270as an example here. 271 272 273Selection of Processor Architecture and Board Type: 274--------------------------------------------------- 275 276For all supported boards there are ready-to-use default 277configurations available; just type "make <board_name>_config". 278 279Example: For a TQM823L module type: 280 281 cd u-boot 282 make TQM823L_config 283 284For the Cogent platform, you need to specify the cpu type as well; 285e.g. "make cogent_mpc8xx_config". And also configure the cogent 286directory according to the instructions in cogent/README. 287 288 289Configuration Options: 290---------------------- 291 292Configuration depends on the combination of board and CPU type; all 293such information is kept in a configuration file 294"include/configs/<board_name>.h". 295 296Example: For a TQM823L module, all configuration settings are in 297"include/configs/TQM823L.h". 298 299 300Many of the options are named exactly as the corresponding Linux 301kernel configuration options. The intention is to make it easier to 302build a config tool - later. 303 304 305The following options need to be configured: 306 307- CPU Type: Define exactly one of 308 309 PowerPC based CPUs: 310 ------------------- 311 CONFIG_MPC823, CONFIG_MPC850, CONFIG_MPC855, CONFIG_MPC860 312 or CONFIG_MPC5xx 313 or CONFIG_MPC824X, CONFIG_MPC8260 314 or CONFIG_MPC85xx 315 or CONFIG_IOP480 316 or CONFIG_405GP 317 or CONFIG_405EP 318 or CONFIG_440 319 or CONFIG_MPC74xx 320 or CONFIG_750FX 321 322 ARM based CPUs: 323 --------------- 324 CONFIG_SA1110 325 CONFIG_ARM7 326 CONFIG_PXA250 327 328 329- Board Type: Define exactly one of 330 331 PowerPC based boards: 332 --------------------- 333 334 CONFIG_ADCIOP, CONFIG_ICU862 CONFIG_RPXsuper, 335 CONFIG_ADS860, CONFIG_IP860, CONFIG_SM850, 336 CONFIG_AMX860, CONFIG_IPHASE4539, CONFIG_SPD823TS, 337 CONFIG_AR405, CONFIG_IVML24, CONFIG_SXNI855T, 338 CONFIG_BAB7xx, CONFIG_IVML24_128, CONFIG_Sandpoint8240, 339 CONFIG_CANBT, CONFIG_IVML24_256, CONFIG_Sandpoint8245, 340 CONFIG_CCM, CONFIG_IVMS8, CONFIG_TQM823L, 341 CONFIG_CPCI405, CONFIG_IVMS8_128, CONFIG_TQM850L, 342 CONFIG_CPCI4052, CONFIG_IVMS8_256, CONFIG_TQM855L, 343 CONFIG_CPCIISER4, CONFIG_LANTEC, CONFIG_TQM860L, 344 CONFIG_CPU86, CONFIG_MBX, CONFIG_TQM8260, 345 CONFIG_CRAYL1, CONFIG_MBX860T, CONFIG_TTTech, 346 CONFIG_CU824, CONFIG_MHPC, CONFIG_UTX8245, 347 CONFIG_DASA_SIM, CONFIG_MIP405, CONFIG_W7OLMC, 348 CONFIG_DU405, CONFIG_MOUSSE, CONFIG_W7OLMG, 349 CONFIG_ELPPC, CONFIG_MPC8260ADS, CONFIG_WALNUT405, 350 CONFIG_ERIC, CONFIG_MUSENKI, CONFIG_ZUMA, 351 CONFIG_ESTEEM192E, CONFIG_MVS1, CONFIG_c2mon, 352 CONFIG_ETX094, CONFIG_NX823, CONFIG_cogent_mpc8260, 353 CONFIG_EVB64260, CONFIG_OCRTC, CONFIG_cogent_mpc8xx, 354 CONFIG_FADS823, CONFIG_ORSG, CONFIG_ep8260, 355 CONFIG_FADS850SAR, CONFIG_OXC, CONFIG_gw8260, 356 CONFIG_FADS860T, CONFIG_PCI405, CONFIG_hermes, 357 CONFIG_FLAGADM, CONFIG_PCIPPC2, CONFIG_hymod, 358 CONFIG_FPS850L, CONFIG_PCIPPC6, CONFIG_lwmon, 359 CONFIG_GEN860T, CONFIG_PIP405, CONFIG_pcu_e, 360 CONFIG_GENIETV, CONFIG_PM826, CONFIG_ppmc8260, 361 CONFIG_GTH, CONFIG_RPXClassic, CONFIG_rsdproto, 362 CONFIG_IAD210, CONFIG_RPXlite, CONFIG_sbc8260, 363 CONFIG_EBONY, CONFIG_sacsng, CONFIG_FPS860L, 364 CONFIG_V37, CONFIG_ELPT860, CONFIG_CMI, 365 CONFIG_NETVIA, CONFIG_RBC823, CONFIG_ZPC1900, 366 CONFIG_MPC8540ADS, CONFIG_MPC8560ADS 367 368 ARM based boards: 369 ----------------- 370 371 CONFIG_HHP_CRADLE, CONFIG_DNP1110, CONFIG_EP7312, 372 CONFIG_IMPA7, CONFIG_LART, CONFIG_LUBBOCK, 373 CONFIG_INNOVATOROMAP1510, CONFIG_INNOVATOROMAP1610 374 CONFIG_SHANNON, CONFIG_SMDK2400, CONFIG_SMDK2410, 375 CONFIG_TRAB, CONFIG_VCMA9, CONFIG_AT91RM9200DK 376 377 378- CPU Module Type: (if CONFIG_COGENT is defined) 379 Define exactly one of 380 CONFIG_CMA286_60_OLD 381--- FIXME --- not tested yet: 382 CONFIG_CMA286_60, CONFIG_CMA286_21, CONFIG_CMA286_60P, 383 CONFIG_CMA287_23, CONFIG_CMA287_50 384 385- Motherboard Type: (if CONFIG_COGENT is defined) 386 Define exactly one of 387 CONFIG_CMA101, CONFIG_CMA102 388 389- Motherboard I/O Modules: (if CONFIG_COGENT is defined) 390 Define one or more of 391 CONFIG_CMA302 392 393- Motherboard Options: (if CONFIG_CMA101 or CONFIG_CMA102 are defined) 394 Define one or more of 395 CONFIG_LCD_HEARTBEAT - update a character position on 396 the lcd display every second with 397 a "rotator" |\-/|\-/ 398 399- Board flavour: (if CONFIG_MPC8260ADS is defined) 400 CONFIG_ADSTYPE 401 Possible values are: 402 CFG_8260ADS - original MPC8260ADS 403 CFG_8266ADS - MPC8266ADS (untested) 404 CFG_PQ2FADS - PQ2FADS-ZU or PQ2FADS-VR 405 406 407- MPC824X Family Member (if CONFIG_MPC824X is defined) 408 Define exactly one of 409 CONFIG_MPC8240, CONFIG_MPC8245 410 411- 8xx CPU Options: (if using an 8xx cpu) 412 Define one or more of 413 CONFIG_8xx_GCLK_FREQ - if get_gclk_freq() cannot work 414 e.g. if there is no 32KHz 415 reference PIT/RTC clock 416 417- Linux Kernel Interface: 418 CONFIG_CLOCKS_IN_MHZ 419 420 U-Boot stores all clock information in Hz 421 internally. For binary compatibility with older Linux 422 kernels (which expect the clocks passed in the 423 bd_info data to be in MHz) the environment variable 424 "clocks_in_mhz" can be defined so that U-Boot 425 converts clock data to MHZ before passing it to the 426 Linux kernel. 427 When CONFIG_CLOCKS_IN_MHZ is defined, a definition of 428 "clocks_in_mhz=1" is automatically included in the 429 default environment. 430 431 CONFIG_MEMSIZE_IN_BYTES [relevant for MIPS only] 432 433 When transfering memsize parameter to linux, some versions 434 expect it to be in bytes, others in MB. 435 Define CONFIG_MEMSIZE_IN_BYTES to make it in bytes. 436 437- Console Interface: 438 Depending on board, define exactly one serial port 439 (like CONFIG_8xx_CONS_SMC1, CONFIG_8xx_CONS_SMC2, 440 CONFIG_8xx_CONS_SCC1, ...), or switch off the serial 441 console by defining CONFIG_8xx_CONS_NONE 442 443 Note: if CONFIG_8xx_CONS_NONE is defined, the serial 444 port routines must be defined elsewhere 445 (i.e. serial_init(), serial_getc(), ...) 446 447 CONFIG_CFB_CONSOLE 448 Enables console device for a color framebuffer. Needs following 449 defines (cf. smiLynxEM, i8042, board/eltec/bab7xx) 450 VIDEO_FB_LITTLE_ENDIAN graphic memory organisation 451 (default big endian) 452 VIDEO_HW_RECTFILL graphic chip supports 453 rectangle fill 454 (cf. smiLynxEM) 455 VIDEO_HW_BITBLT graphic chip supports 456 bit-blit (cf. smiLynxEM) 457 VIDEO_VISIBLE_COLS visible pixel columns 458 (cols=pitch) 459 VIDEO_VISIBLE_ROWS visible pixel rows 460 VIDEO_PIXEL_SIZE bytes per pixel 461 VIDEO_DATA_FORMAT graphic data format 462 (0-5, cf. cfb_console.c) 463 VIDEO_FB_ADRS framebuffer address 464 VIDEO_KBD_INIT_FCT keyboard int fct 465 (i.e. i8042_kbd_init()) 466 VIDEO_TSTC_FCT test char fct 467 (i.e. i8042_tstc) 468 VIDEO_GETC_FCT get char fct 469 (i.e. i8042_getc) 470 CONFIG_CONSOLE_CURSOR cursor drawing on/off 471 (requires blink timer 472 cf. i8042.c) 473 CFG_CONSOLE_BLINK_COUNT blink interval (cf. i8042.c) 474 CONFIG_CONSOLE_TIME display time/date info in 475 upper right corner 476 (requires CFG_CMD_DATE) 477 CONFIG_VIDEO_LOGO display Linux logo in 478 upper left corner 479 CONFIG_VIDEO_BMP_LOGO use bmp_logo.h instead of 480 linux_logo.h for logo. 481 Requires CONFIG_VIDEO_LOGO 482 CONFIG_CONSOLE_EXTRA_INFO 483 addional board info beside 484 the logo 485 486 When CONFIG_CFB_CONSOLE is defined, video console is 487 default i/o. Serial console can be forced with 488 environment 'console=serial'. 489 490 When CONFIG_SILENT_CONSOLE is defined, all console 491 messages (by U-Boot and Linux!) can be silenced with 492 the "silent" environment variable. See 493 doc/README.silent for more information. 494 495- Console Baudrate: 496 CONFIG_BAUDRATE - in bps 497 Select one of the baudrates listed in 498 CFG_BAUDRATE_TABLE, see below. 499 500- Interrupt driven serial port input: 501 CONFIG_SERIAL_SOFTWARE_FIFO 502 503 PPC405GP only. 504 Use an interrupt handler for receiving data on the 505 serial port. It also enables using hardware handshake 506 (RTS/CTS) and UART's built-in FIFO. Set the number of 507 bytes the interrupt driven input buffer should have. 508 509 Set to 0 to disable this feature (this is the default). 510 This will also disable hardware handshake. 511 512- Console UART Number: 513 CONFIG_UART1_CONSOLE 514 515 IBM PPC4xx only. 516 If defined internal UART1 (and not UART0) is used 517 as default U-Boot console. 518 519- Boot Delay: CONFIG_BOOTDELAY - in seconds 520 Delay before automatically booting the default image; 521 set to -1 to disable autoboot. 522 523 See doc/README.autoboot for these options that 524 work with CONFIG_BOOTDELAY. None are required. 525 CONFIG_BOOT_RETRY_TIME 526 CONFIG_BOOT_RETRY_MIN 527 CONFIG_AUTOBOOT_KEYED 528 CONFIG_AUTOBOOT_PROMPT 529 CONFIG_AUTOBOOT_DELAY_STR 530 CONFIG_AUTOBOOT_STOP_STR 531 CONFIG_AUTOBOOT_DELAY_STR2 532 CONFIG_AUTOBOOT_STOP_STR2 533 CONFIG_ZERO_BOOTDELAY_CHECK 534 CONFIG_RESET_TO_RETRY 535 536- Autoboot Command: 537 CONFIG_BOOTCOMMAND 538 Only needed when CONFIG_BOOTDELAY is enabled; 539 define a command string that is automatically executed 540 when no character is read on the console interface 541 within "Boot Delay" after reset. 542 543 CONFIG_BOOTARGS 544 This can be used to pass arguments to the bootm 545 command. The value of CONFIG_BOOTARGS goes into the 546 environment value "bootargs". 547 548 CONFIG_RAMBOOT and CONFIG_NFSBOOT 549 The value of these goes into the environment as 550 "ramboot" and "nfsboot" respectively, and can be used 551 as a convenience, when switching between booting from 552 ram and nfs. 553 554- Pre-Boot Commands: 555 CONFIG_PREBOOT 556 557 When this option is #defined, the existence of the 558 environment variable "preboot" will be checked 559 immediately before starting the CONFIG_BOOTDELAY 560 countdown and/or running the auto-boot command resp. 561 entering interactive mode. 562 563 This feature is especially useful when "preboot" is 564 automatically generated or modified. For an example 565 see the LWMON board specific code: here "preboot" is 566 modified when the user holds down a certain 567 combination of keys on the (special) keyboard when 568 booting the systems 569 570- Serial Download Echo Mode: 571 CONFIG_LOADS_ECHO 572 If defined to 1, all characters received during a 573 serial download (using the "loads" command) are 574 echoed back. This might be needed by some terminal 575 emulations (like "cu"), but may as well just take 576 time on others. This setting #define's the initial 577 value of the "loads_echo" environment variable. 578 579- Kgdb Serial Baudrate: (if CFG_CMD_KGDB is defined) 580 CONFIG_KGDB_BAUDRATE 581 Select one of the baudrates listed in 582 CFG_BAUDRATE_TABLE, see below. 583 584- Monitor Functions: 585 CONFIG_COMMANDS 586 Most monitor functions can be selected (or 587 de-selected) by adjusting the definition of 588 CONFIG_COMMANDS; to select individual functions, 589 #define CONFIG_COMMANDS by "OR"ing any of the 590 following values: 591 592 #define enables commands: 593 ------------------------- 594 CFG_CMD_ASKENV * ask for env variable 595 CFG_CMD_AUTOSCRIPT Autoscript Support 596 CFG_CMD_BDI bdinfo 597 CFG_CMD_BEDBUG Include BedBug Debugger 598 CFG_CMD_BMP * BMP support 599 CFG_CMD_BOOTD bootd 600 CFG_CMD_CACHE icache, dcache 601 CFG_CMD_CONSOLE coninfo 602 CFG_CMD_DATE * support for RTC, date/time... 603 CFG_CMD_DHCP DHCP support 604 CFG_CMD_DIAG * Diagnostics 605 CFG_CMD_DOC * Disk-On-Chip Support 606 CFG_CMD_DTT Digital Therm and Thermostat 607 CFG_CMD_ECHO * echo arguments 608 CFG_CMD_EEPROM * EEPROM read/write support 609 CFG_CMD_ELF bootelf, bootvx 610 CFG_CMD_ENV saveenv 611 CFG_CMD_FDC * Floppy Disk Support 612 CFG_CMD_FAT FAT partition support 613 CFG_CMD_FDOS * Dos diskette Support 614 CFG_CMD_FLASH flinfo, erase, protect 615 CFG_CMD_FPGA FPGA device initialization support 616 CFG_CMD_HWFLOW * RTS/CTS hw flow control 617 CFG_CMD_I2C * I2C serial bus support 618 CFG_CMD_IDE * IDE harddisk support 619 CFG_CMD_IMI iminfo 620 CFG_CMD_IMLS List all found images 621 CFG_CMD_IMMAP * IMMR dump support 622 CFG_CMD_IRQ * irqinfo 623 CFG_CMD_JFFS2 * JFFS2 Support 624 CFG_CMD_KGDB * kgdb 625 CFG_CMD_LOADB loadb 626 CFG_CMD_LOADS loads 627 CFG_CMD_MEMORY md, mm, nm, mw, cp, cmp, crc, base, 628 loop, mtest 629 CFG_CMD_MISC Misc functions like sleep etc 630 CFG_CMD_MMC MMC memory mapped support 631 CFG_CMD_MII MII utility commands 632 CFG_CMD_NAND * NAND support 633 CFG_CMD_NET bootp, tftpboot, rarpboot 634 CFG_CMD_PCI * pciinfo 635 CFG_CMD_PCMCIA * PCMCIA support 636 CFG_CMD_PING * send ICMP ECHO_REQUEST to network host 637 CFG_CMD_PORTIO * Port I/O 638 CFG_CMD_REGINFO * Register dump 639 CFG_CMD_RUN run command in env variable 640 CFG_CMD_SAVES save S record dump 641 CFG_CMD_SCSI * SCSI Support 642 CFG_CMD_SDRAM * print SDRAM configuration information 643 CFG_CMD_SETGETDCR Support for DCR Register access (4xx only) 644 CFG_CMD_SPI * SPI serial bus support 645 CFG_CMD_USB * USB support 646 CFG_CMD_VFD * VFD support (TRAB) 647 CFG_CMD_BSP * Board SPecific functions 648 ----------------------------------------------- 649 CFG_CMD_ALL all 650 651 CFG_CMD_DFL Default configuration; at the moment 652 this is includes all commands, except 653 the ones marked with "*" in the list 654 above. 655 656 If you don't define CONFIG_COMMANDS it defaults to 657 CFG_CMD_DFL in include/cmd_confdefs.h. A board can 658 override the default settings in the respective 659 include file. 660 661 EXAMPLE: If you want all functions except of network 662 support you can write: 663 664 #define CONFIG_COMMANDS (CFG_CMD_ALL & ~CFG_CMD_NET) 665 666 667 Note: Don't enable the "icache" and "dcache" commands 668 (configuration option CFG_CMD_CACHE) unless you know 669 what you (and your U-Boot users) are doing. Data 670 cache cannot be enabled on systems like the 8xx or 671 8260 (where accesses to the IMMR region must be 672 uncached), and it cannot be disabled on all other 673 systems where we (mis-) use the data cache to hold an 674 initial stack and some data. 675 676 677 XXX - this list needs to get updated! 678 679- Watchdog: 680 CONFIG_WATCHDOG 681 If this variable is defined, it enables watchdog 682 support. There must be support in the platform specific 683 code for a watchdog. For the 8xx and 8260 CPUs, the 684 SIU Watchdog feature is enabled in the SYPCR 685 register. 686 687- U-Boot Version: 688 CONFIG_VERSION_VARIABLE 689 If this variable is defined, an environment variable 690 named "ver" is created by U-Boot showing the U-Boot 691 version as printed by the "version" command. 692 This variable is readonly. 693 694- Real-Time Clock: 695 696 When CFG_CMD_DATE is selected, the type of the RTC 697 has to be selected, too. Define exactly one of the 698 following options: 699 700 CONFIG_RTC_MPC8xx - use internal RTC of MPC8xx 701 CONFIG_RTC_PCF8563 - use Philips PCF8563 RTC 702 CONFIG_RTC_MC146818 - use MC146818 RTC 703 CONFIG_RTC_DS1307 - use Maxim, Inc. DS1307 RTC 704 CONFIG_RTC_DS1337 - use Maxim, Inc. DS1337 RTC 705 CONFIG_RTC_DS1338 - use Maxim, Inc. DS1338 RTC 706 CONFIG_RTC_DS164x - use Dallas DS164x RTC 707 708 Note that if the RTC uses I2C, then the I2C interface 709 must also be configured. See I2C Support, below. 710 711- Timestamp Support: 712 713 When CONFIG_TIMESTAMP is selected, the timestamp 714 (date and time) of an image is printed by image 715 commands like bootm or iminfo. This option is 716 automatically enabled when you select CFG_CMD_DATE . 717 718- Partition Support: 719 CONFIG_MAC_PARTITION and/or CONFIG_DOS_PARTITION 720 and/or CONFIG_ISO_PARTITION 721 722 If IDE or SCSI support is enabled (CFG_CMD_IDE or 723 CFG_CMD_SCSI) you must configure support for at least 724 one partition type as well. 725 726- IDE Reset method: 727 CONFIG_IDE_RESET_ROUTINE 728 729 Set this to define that instead of a reset Pin, the 730 routine ide_set_reset(int idereset) will be used. 731 732- ATAPI Support: 733 CONFIG_ATAPI 734 735 Set this to enable ATAPI support. 736 737- SCSI Support: 738 At the moment only there is only support for the 739 SYM53C8XX SCSI controller; define 740 CONFIG_SCSI_SYM53C8XX to enable it. 741 742 CFG_SCSI_MAX_LUN [8], CFG_SCSI_MAX_SCSI_ID [7] and 743 CFG_SCSI_MAX_DEVICE [CFG_SCSI_MAX_SCSI_ID * 744 CFG_SCSI_MAX_LUN] can be adjusted to define the 745 maximum numbers of LUNs, SCSI ID's and target 746 devices. 747 CFG_SCSI_SYM53C8XX_CCF to fix clock timing (80Mhz) 748 749- NETWORK Support (PCI): 750 CONFIG_E1000 751 Support for Intel 8254x gigabit chips. 752 753 CONFIG_EEPRO100 754 Support for Intel 82557/82559/82559ER chips. 755 Optional CONFIG_EEPRO100_SROM_WRITE enables eeprom 756 write routine for first time initialisation. 757 758 CONFIG_TULIP 759 Support for Digital 2114x chips. 760 Optional CONFIG_TULIP_SELECT_MEDIA for board specific 761 modem chip initialisation (KS8761/QS6611). 762 763 CONFIG_NATSEMI 764 Support for National dp83815 chips. 765 766 CONFIG_NS8382X 767 Support for National dp8382[01] gigabit chips. 768 769- NETWORK Support (other): 770 771 CONFIG_DRIVER_LAN91C96 772 Support for SMSC's LAN91C96 chips. 773 774 CONFIG_LAN91C96_BASE 775 Define this to hold the physical address 776 of the LAN91C96's I/O space 777 778 CONFIG_LAN91C96_USE_32_BIT 779 Define this to enable 32 bit addressing 780 781- USB Support: 782 At the moment only the UHCI host controller is 783 supported (PIP405, MIP405); define 784 CONFIG_USB_UHCI to enable it. 785 define CONFIG_USB_KEYBOARD to enable the USB Keyboard 786 end define CONFIG_USB_STORAGE to enable the USB 787 storage devices. 788 Note: 789 Supported are USB Keyboards and USB Floppy drives 790 (TEAC FD-05PUB). 791 792- MMC Support: 793 The MMC controller on the Intel PXA is supported. To 794 enable this define CONFIG_MMC. The MMC can be 795 accessed from the boot prompt by mapping the device 796 to physical memory similar to flash. Command line is 797 enabled with CFG_CMD_MMC. The MMC driver also works with 798 the FAT fs. This is enabled with CFG_CMD_FAT. 799 800- Keyboard Support: 801 CONFIG_ISA_KEYBOARD 802 803 Define this to enable standard (PC-Style) keyboard 804 support 805 806 CONFIG_I8042_KBD 807 Standard PC keyboard driver with US (is default) and 808 GERMAN key layout (switch via environment 'keymap=de') support. 809 Export function i8042_kbd_init, i8042_tstc and i8042_getc 810 for cfb_console. Supports cursor blinking. 811 812- Video support: 813 CONFIG_VIDEO 814 815 Define this to enable video support (for output to 816 video). 817 818 CONFIG_VIDEO_CT69000 819 820 Enable Chips & Technologies 69000 Video chip 821 822 CONFIG_VIDEO_SMI_LYNXEM 823 Enable Silicon Motion SMI 712/710/810 Video chip 824 Videomode are selected via environment 'videomode' with 825 standard LiLo mode numbers. 826 Following modes are supported (* is default): 827 828 800x600 1024x768 1280x1024 829 256 (8bit) 303* 305 307 830 65536 (16bit) 314 317 31a 831 16,7 Mill (24bit) 315 318 31b 832 (i.e. setenv videomode 317; saveenv; reset;) 833 834 CONFIG_VIDEO_SED13806 835 Enable Epson SED13806 driver. This driver supports 8bpp 836 and 16bpp modes defined by CONFIG_VIDEO_SED13806_8BPP 837 or CONFIG_VIDEO_SED13806_16BPP 838 839- Keyboard Support: 840 CONFIG_KEYBOARD 841 842 Define this to enable a custom keyboard support. 843 This simply calls drv_keyboard_init() which must be 844 defined in your board-specific files. 845 The only board using this so far is RBC823. 846 847- LCD Support: CONFIG_LCD 848 849 Define this to enable LCD support (for output to LCD 850 display); also select one of the supported displays 851 by defining one of these: 852 853 CONFIG_NEC_NL6448AC33: 854 855 NEC NL6448AC33-18. Active, color, single scan. 856 857 CONFIG_NEC_NL6448BC20 858 859 NEC NL6448BC20-08. 6.5", 640x480. 860 Active, color, single scan. 861 862 CONFIG_NEC_NL6448BC33_54 863 864 NEC NL6448BC33-54. 10.4", 640x480. 865 Active, color, single scan. 866 867 CONFIG_SHARP_16x9 868 869 Sharp 320x240. Active, color, single scan. 870 It isn't 16x9, and I am not sure what it is. 871 872 CONFIG_SHARP_LQ64D341 873 874 Sharp LQ64D341 display, 640x480. 875 Active, color, single scan. 876 877 CONFIG_HLD1045 878 879 HLD1045 display, 640x480. 880 Active, color, single scan. 881 882 CONFIG_OPTREX_BW 883 884 Optrex CBL50840-2 NF-FW 99 22 M5 885 or 886 Hitachi LMG6912RPFC-00T 887 or 888 Hitachi SP14Q002 889 890 320x240. Black & white. 891 892 Normally display is black on white background; define 893 CFG_WHITE_ON_BLACK to get it inverted. 894 895- Splash Screen Support: CONFIG_SPLASH_SCREEN 896 897 If this option is set, the environment is checked for 898 a variable "splashimage". If found, the usual display 899 of logo, copyright and system information on the LCD 900 is supressed and the BMP image at the address 901 specified in "splashimage" is loaded instead. The 902 console is redirected to the "nulldev", too. This 903 allows for a "silent" boot where a splash screen is 904 loaded very quickly after power-on. 905 906- Compression support: 907 CONFIG_BZIP2 908 909 If this option is set, support for bzip2 compressed 910 images is included. If not, only uncompressed and gzip 911 compressed images are supported. 912 913 NOTE: the bzip2 algorithm requires a lot of RAM, so 914 the malloc area (as defined by CFG_MALLOC_LEN) should 915 be at least 4MB. 916 917- Ethernet address: 918 CONFIG_ETHADDR 919 CONFIG_ETH2ADDR 920 CONFIG_ETH3ADDR 921 922 Define a default value for ethernet address to use 923 for the respective ethernet interface, in case this 924 is not determined automatically. 925 926- IP address: 927 CONFIG_IPADDR 928 929 Define a default value for the IP address to use for 930 the default ethernet interface, in case this is not 931 determined through e.g. bootp. 932 933- Server IP address: 934 CONFIG_SERVERIP 935 936 Defines a default value for theIP address of a TFTP 937 server to contact when using the "tftboot" command. 938 939- BOOTP Recovery Mode: 940 CONFIG_BOOTP_RANDOM_DELAY 941 942 If you have many targets in a network that try to 943 boot using BOOTP, you may want to avoid that all 944 systems send out BOOTP requests at precisely the same 945 moment (which would happen for instance at recovery 946 from a power failure, when all systems will try to 947 boot, thus flooding the BOOTP server. Defining 948 CONFIG_BOOTP_RANDOM_DELAY causes a random delay to be 949 inserted before sending out BOOTP requests. The 950 following delays are insterted then: 951 952 1st BOOTP request: delay 0 ... 1 sec 953 2nd BOOTP request: delay 0 ... 2 sec 954 3rd BOOTP request: delay 0 ... 4 sec 955 4th and following 956 BOOTP requests: delay 0 ... 8 sec 957 958- DHCP Advanced Options: 959 CONFIG_BOOTP_MASK 960 961 You can fine tune the DHCP functionality by adding 962 these flags to the CONFIG_BOOTP_MASK define: 963 964 CONFIG_BOOTP_DNS2 - If a DHCP client requests the DNS 965 serverip from a DHCP server, it is possible that more 966 than one DNS serverip is offered to the client. 967 If CONFIG_BOOTP_DNS2 is enabled, the secondary DNS 968 serverip will be stored in the additional environment 969 variable "dnsip2". The first DNS serverip is always 970 stored in the variable "dnsip", when CONFIG_BOOTP_DNS 971 is added to the CONFIG_BOOTP_MASK. 972 973 CONFIG_BOOTP_SEND_HOSTNAME - Some DHCP servers are capable 974 to do a dynamic update of a DNS server. To do this, they 975 need the hostname of the DHCP requester. 976 If CONFIG_BOOP_SEND_HOSTNAME is added to the 977 CONFIG_BOOTP_MASK, the content of the "hostname" 978 environment variable is passed as option 12 to 979 the DHCP server. 980 981- Status LED: CONFIG_STATUS_LED 982 983 Several configurations allow to display the current 984 status using a LED. For instance, the LED will blink 985 fast while running U-Boot code, stop blinking as 986 soon as a reply to a BOOTP request was received, and 987 start blinking slow once the Linux kernel is running 988 (supported by a status LED driver in the Linux 989 kernel). Defining CONFIG_STATUS_LED enables this 990 feature in U-Boot. 991 992- CAN Support: CONFIG_CAN_DRIVER 993 994 Defining CONFIG_CAN_DRIVER enables CAN driver support 995 on those systems that support this (optional) 996 feature, like the TQM8xxL modules. 997 998- I2C Support: CONFIG_HARD_I2C | CONFIG_SOFT_I2C 999 1000 These enable I2C serial bus commands. Defining either of 1001 (but not both of) CONFIG_HARD_I2C or CONFIG_SOFT_I2C will 1002 include the appropriate I2C driver for the selected cpu. 1003 1004 This will allow you to use i2c commands at the u-boot 1005 command line (as long as you set CFG_CMD_I2C in 1006 CONFIG_COMMANDS) and communicate with i2c based realtime 1007 clock chips. See common/cmd_i2c.c for a description of the 1008 command line interface. 1009 1010 CONFIG_HARD_I2C selects the CPM hardware driver for I2C. 1011 1012 CONFIG_SOFT_I2C configures u-boot to use a software (aka 1013 bit-banging) driver instead of CPM or similar hardware 1014 support for I2C. 1015 1016 There are several other quantities that must also be 1017 defined when you define CONFIG_HARD_I2C or CONFIG_SOFT_I2C. 1018 1019 In both cases you will need to define CFG_I2C_SPEED 1020 to be the frequency (in Hz) at which you wish your i2c bus 1021 to run and CFG_I2C_SLAVE to be the address of this node (ie 1022 the cpu's i2c node address). 1023 1024 Now, the u-boot i2c code for the mpc8xx (cpu/mpc8xx/i2c.c) 1025 sets the cpu up as a master node and so its address should 1026 therefore be cleared to 0 (See, eg, MPC823e User's Manual 1027 p.16-473). So, set CFG_I2C_SLAVE to 0. 1028 1029 That's all that's required for CONFIG_HARD_I2C. 1030 1031 If you use the software i2c interface (CONFIG_SOFT_I2C) 1032 then the following macros need to be defined (examples are 1033 from include/configs/lwmon.h): 1034 1035 I2C_INIT 1036 1037 (Optional). Any commands necessary to enable the I2C 1038 controller or configure ports. 1039 1040 eg: #define I2C_INIT (immr->im_cpm.cp_pbdir |= PB_SCL) 1041 1042 I2C_PORT 1043 1044 (Only for MPC8260 CPU). The I/O port to use (the code 1045 assumes both bits are on the same port). Valid values 1046 are 0..3 for ports A..D. 1047 1048 I2C_ACTIVE 1049 1050 The code necessary to make the I2C data line active 1051 (driven). If the data line is open collector, this 1052 define can be null. 1053 1054 eg: #define I2C_ACTIVE (immr->im_cpm.cp_pbdir |= PB_SDA) 1055 1056 I2C_TRISTATE 1057 1058 The code necessary to make the I2C data line tri-stated 1059 (inactive). If the data line is open collector, this 1060 define can be null. 1061 1062 eg: #define I2C_TRISTATE (immr->im_cpm.cp_pbdir &= ~PB_SDA) 1063 1064 I2C_READ 1065 1066 Code that returns TRUE if the I2C data line is high, 1067 FALSE if it is low. 1068 1069 eg: #define I2C_READ ((immr->im_cpm.cp_pbdat & PB_SDA) != 0) 1070 1071 I2C_SDA(bit) 1072 1073 If <bit> is TRUE, sets the I2C data line high. If it 1074 is FALSE, it clears it (low). 1075 1076 eg: #define I2C_SDA(bit) \ 1077 if(bit) immr->im_cpm.cp_pbdat |= PB_SDA; \ 1078 else immr->im_cpm.cp_pbdat &= ~PB_SDA 1079 1080 I2C_SCL(bit) 1081 1082 If <bit> is TRUE, sets the I2C clock line high. If it 1083 is FALSE, it clears it (low). 1084 1085 eg: #define I2C_SCL(bit) \ 1086 if(bit) immr->im_cpm.cp_pbdat |= PB_SCL; \ 1087 else immr->im_cpm.cp_pbdat &= ~PB_SCL 1088 1089 I2C_DELAY 1090 1091 This delay is invoked four times per clock cycle so this 1092 controls the rate of data transfer. The data rate thus 1093 is 1 / (I2C_DELAY * 4). Often defined to be something 1094 like: 1095 1096 #define I2C_DELAY udelay(2) 1097 1098 CFG_I2C_INIT_BOARD 1099 1100 When a board is reset during an i2c bus transfer 1101 chips might think that the current transfer is still 1102 in progress. On some boards it is possible to access 1103 the i2c SCLK line directly, either by using the 1104 processor pin as a GPIO or by having a second pin 1105 connected to the bus. If this option is defined a 1106 custom i2c_init_board() routine in boards/xxx/board.c 1107 is run early in the boot sequence. 1108 1109- SPI Support: CONFIG_SPI 1110 1111 Enables SPI driver (so far only tested with 1112 SPI EEPROM, also an instance works with Crystal A/D and 1113 D/As on the SACSng board) 1114 1115 CONFIG_SPI_X 1116 1117 Enables extended (16-bit) SPI EEPROM addressing. 1118 (symmetrical to CONFIG_I2C_X) 1119 1120 CONFIG_SOFT_SPI 1121 1122 Enables a software (bit-bang) SPI driver rather than 1123 using hardware support. This is a general purpose 1124 driver that only requires three general I/O port pins 1125 (two outputs, one input) to function. If this is 1126 defined, the board configuration must define several 1127 SPI configuration items (port pins to use, etc). For 1128 an example, see include/configs/sacsng.h. 1129 1130- FPGA Support: CONFIG_FPGA_COUNT 1131 1132 Specify the number of FPGA devices to support. 1133 1134 CONFIG_FPGA 1135 1136 Used to specify the types of FPGA devices. For 1137 example, 1138 #define CONFIG_FPGA CFG_XILINX_VIRTEX2 1139 1140 CFG_FPGA_PROG_FEEDBACK 1141 1142 Enable printing of hash marks during FPGA 1143 configuration. 1144 1145 CFG_FPGA_CHECK_BUSY 1146 1147 Enable checks on FPGA configuration interface busy 1148 status by the configuration function. This option 1149 will require a board or device specific function to 1150 be written. 1151 1152 CONFIG_FPGA_DELAY 1153 1154 If defined, a function that provides delays in the 1155 FPGA configuration driver. 1156 1157 CFG_FPGA_CHECK_CTRLC 1158 1159 Allow Control-C to interrupt FPGA configuration 1160 1161 CFG_FPGA_CHECK_ERROR 1162 1163 Check for configuration errors during FPGA bitfile 1164 loading. For example, abort during Virtex II 1165 configuration if the INIT_B line goes low (which 1166 indicated a CRC error). 1167 1168 CFG_FPGA_WAIT_INIT 1169 1170 Maximum time to wait for the INIT_B line to deassert 1171 after PROB_B has been deasserted during a Virtex II 1172 FPGA configuration sequence. The default time is 500 mS. 1173 1174 CFG_FPGA_WAIT_BUSY 1175 1176 Maximum time to wait for BUSY to deassert during 1177 Virtex II FPGA configuration. The default is 5 mS. 1178 1179 CFG_FPGA_WAIT_CONFIG 1180 1181 Time to wait after FPGA configuration. The default is 1182 200 mS. 1183 1184- FPGA Support: CONFIG_FPGA_COUNT 1185 1186 Specify the number of FPGA devices to support. 1187 1188 CONFIG_FPGA 1189 1190 Used to specify the types of FPGA devices. For example, 1191 #define CONFIG_FPGA CFG_XILINX_VIRTEX2 1192 1193 CFG_FPGA_PROG_FEEDBACK 1194 1195 Enable printing of hash marks during FPGA configuration. 1196 1197 CFG_FPGA_CHECK_BUSY 1198 1199 Enable checks on FPGA configuration interface busy 1200 status by the configuration function. This option 1201 will require a board or device specific function to 1202 be written. 1203 1204 CONFIG_FPGA_DELAY 1205 1206 If defined, a function that provides delays in the FPGA 1207 configuration driver. 1208 1209 CFG_FPGA_CHECK_CTRLC 1210 Allow Control-C to interrupt FPGA configuration 1211 1212 CFG_FPGA_CHECK_ERROR 1213 1214 Check for configuration errors during FPGA bitfile 1215 loading. For example, abort during Virtex II 1216 configuration if the INIT_B line goes low (which 1217 indicated a CRC error). 1218 1219 CFG_FPGA_WAIT_INIT 1220 1221 Maximum time to wait for the INIT_B line to deassert 1222 after PROB_B has been deasserted during a Virtex II 1223 FPGA configuration sequence. The default time is 500 1224 mS. 1225 1226 CFG_FPGA_WAIT_BUSY 1227 1228 Maximum time to wait for BUSY to deassert during 1229 Virtex II FPGA configuration. The default is 5 mS. 1230 1231 CFG_FPGA_WAIT_CONFIG 1232 1233 Time to wait after FPGA configuration. The default is 1234 200 mS. 1235 1236- Configuration Management: 1237 CONFIG_IDENT_STRING 1238 1239 If defined, this string will be added to the U-Boot 1240 version information (U_BOOT_VERSION) 1241 1242- Vendor Parameter Protection: 1243 1244 U-Boot considers the values of the environment 1245 variables "serial#" (Board Serial Number) and 1246 "ethaddr" (Ethernet Address) to be parameters that 1247 are set once by the board vendor / manufacturer, and 1248 protects these variables from casual modification by 1249 the user. Once set, these variables are read-only, 1250 and write or delete attempts are rejected. You can 1251 change this behviour: 1252 1253 If CONFIG_ENV_OVERWRITE is #defined in your config 1254 file, the write protection for vendor parameters is 1255 completely disabled. Anybody can change or delete 1256 these parameters. 1257 1258 Alternatively, if you #define _both_ CONFIG_ETHADDR 1259 _and_ CONFIG_OVERWRITE_ETHADDR_ONCE, a default 1260 ethernet address is installed in the environment, 1261 which can be changed exactly ONCE by the user. [The 1262 serial# is unaffected by this, i. e. it remains 1263 read-only.] 1264 1265- Protected RAM: 1266 CONFIG_PRAM 1267 1268 Define this variable to enable the reservation of 1269 "protected RAM", i. e. RAM which is not overwritten 1270 by U-Boot. Define CONFIG_PRAM to hold the number of 1271 kB you want to reserve for pRAM. You can overwrite 1272 this default value by defining an environment 1273 variable "pram" to the number of kB you want to 1274 reserve. Note that the board info structure will 1275 still show the full amount of RAM. If pRAM is 1276 reserved, a new environment variable "mem" will 1277 automatically be defined to hold the amount of 1278 remaining RAM in a form that can be passed as boot 1279 argument to Linux, for instance like that: 1280 1281 setenv bootargs ... mem=\$(mem) 1282 saveenv 1283 1284 This way you can tell Linux not to use this memory, 1285 either, which results in a memory region that will 1286 not be affected by reboots. 1287 1288 *WARNING* If your board configuration uses automatic 1289 detection of the RAM size, you must make sure that 1290 this memory test is non-destructive. So far, the 1291 following board configurations are known to be 1292 "pRAM-clean": 1293 1294 ETX094, IVMS8, IVML24, SPD8xx, TQM8xxL, 1295 HERMES, IP860, RPXlite, LWMON, LANTEC, 1296 PCU_E, FLAGADM, TQM8260 1297 1298- Error Recovery: 1299 CONFIG_PANIC_HANG 1300 1301 Define this variable to stop the system in case of a 1302 fatal error, so that you have to reset it manually. 1303 This is probably NOT a good idea for an embedded 1304 system where you want to system to reboot 1305 automatically as fast as possible, but it may be 1306 useful during development since you can try to debug 1307 the conditions that lead to the situation. 1308 1309 CONFIG_NET_RETRY_COUNT 1310 1311 This variable defines the number of retries for 1312 network operations like ARP, RARP, TFTP, or BOOTP 1313 before giving up the operation. If not defined, a 1314 default value of 5 is used. 1315 1316- Command Interpreter: 1317 CFG_HUSH_PARSER 1318 1319 Define this variable to enable the "hush" shell (from 1320 Busybox) as command line interpreter, thus enabling 1321 powerful command line syntax like 1322 if...then...else...fi conditionals or `&&' and '||' 1323 constructs ("shell scripts"). 1324 1325 If undefined, you get the old, much simpler behaviour 1326 with a somewhat smaller memory footprint. 1327 1328 1329 CFG_PROMPT_HUSH_PS2 1330 1331 This defines the secondary prompt string, which is 1332 printed when the command interpreter needs more input 1333 to complete a command. Usually "> ". 1334 1335 Note: 1336 1337 In the current implementation, the local variables 1338 space and global environment variables space are 1339 separated. Local variables are those you define by 1340 simply typing `name=value'. To access a local 1341 variable later on, you have write `$name' or 1342 `${name}'; to execute the contents of a variable 1343 directly type `$name' at the command prompt. 1344 1345 Global environment variables are those you use 1346 setenv/printenv to work with. To run a command stored 1347 in such a variable, you need to use the run command, 1348 and you must not use the '$' sign to access them. 1349 1350 To store commands and special characters in a 1351 variable, please use double quotation marks 1352 surrounding the whole text of the variable, instead 1353 of the backslashes before semicolons and special 1354 symbols. 1355 1356- Default Environment: 1357 CONFIG_EXTRA_ENV_SETTINGS 1358 1359 Define this to contain any number of null terminated 1360 strings (variable = value pairs) that will be part of 1361 the default environment compiled into the boot image. 1362 1363 For example, place something like this in your 1364 board's config file: 1365 1366 #define CONFIG_EXTRA_ENV_SETTINGS \ 1367 "myvar1=value1\0" \ 1368 "myvar2=value2\0" 1369 1370 Warning: This method is based on knowledge about the 1371 internal format how the environment is stored by the 1372 U-Boot code. This is NOT an official, exported 1373 interface! Although it is unlikely that this format 1374 will change soon, there is no guarantee either. 1375 You better know what you are doing here. 1376 1377 Note: overly (ab)use of the default environment is 1378 discouraged. Make sure to check other ways to preset 1379 the environment like the autoscript function or the 1380 boot command first. 1381 1382- DataFlash Support: 1383 CONFIG_HAS_DATAFLASH 1384 1385 Defining this option enables DataFlash features and 1386 allows to read/write in Dataflash via the standard 1387 commands cp, md... 1388 1389- Show boot progress: 1390 CONFIG_SHOW_BOOT_PROGRESS 1391 1392 Defining this option allows to add some board- 1393 specific code (calling a user-provided function 1394 "show_boot_progress(int)") that enables you to show 1395 the system's boot progress on some display (for 1396 example, some LED's) on your board. At the moment, 1397 the following checkpoints are implemented: 1398 1399 Arg Where When 1400 1 common/cmd_bootm.c before attempting to boot an image 1401 -1 common/cmd_bootm.c Image header has bad magic number 1402 2 common/cmd_bootm.c Image header has correct magic number 1403 -2 common/cmd_bootm.c Image header has bad checksum 1404 3 common/cmd_bootm.c Image header has correct checksum 1405 -3 common/cmd_bootm.c Image data has bad checksum 1406 4 common/cmd_bootm.c Image data has correct checksum 1407 -4 common/cmd_bootm.c Image is for unsupported architecture 1408 5 common/cmd_bootm.c Architecture check OK 1409 -5 common/cmd_bootm.c Wrong Image Type (not kernel, multi, standalone) 1410 6 common/cmd_bootm.c Image Type check OK 1411 -6 common/cmd_bootm.c gunzip uncompression error 1412 -7 common/cmd_bootm.c Unimplemented compression type 1413 7 common/cmd_bootm.c Uncompression OK 1414 -8 common/cmd_bootm.c Wrong Image Type (not kernel, multi, standalone) 1415 8 common/cmd_bootm.c Image Type check OK 1416 -9 common/cmd_bootm.c Unsupported OS (not Linux, BSD, VxWorks, QNX) 1417 9 common/cmd_bootm.c Start initial ramdisk verification 1418 -10 common/cmd_bootm.c Ramdisk header has bad magic number 1419 -11 common/cmd_bootm.c Ramdisk header has bad checksum 1420 10 common/cmd_bootm.c Ramdisk header is OK 1421 -12 common/cmd_bootm.c Ramdisk data has bad checksum 1422 11 common/cmd_bootm.c Ramdisk data has correct checksum 1423 12 common/cmd_bootm.c Ramdisk verification complete, start loading 1424 -13 common/cmd_bootm.c Wrong Image Type (not PPC Linux Ramdisk) 1425 13 common/cmd_bootm.c Start multifile image verification 1426 14 common/cmd_bootm.c No initial ramdisk, no multifile, continue. 1427 15 common/cmd_bootm.c All preparation done, transferring control to OS 1428 1429 -1 common/cmd_doc.c Bad usage of "doc" command 1430 -1 common/cmd_doc.c No boot device 1431 -1 common/cmd_doc.c Unknown Chip ID on boot device 1432 -1 common/cmd_doc.c Read Error on boot device 1433 -1 common/cmd_doc.c Image header has bad magic number 1434 1435 -1 common/cmd_ide.c Bad usage of "ide" command 1436 -1 common/cmd_ide.c No boot device 1437 -1 common/cmd_ide.c Unknown boot device 1438 -1 common/cmd_ide.c Unknown partition table 1439 -1 common/cmd_ide.c Invalid partition type 1440 -1 common/cmd_ide.c Read Error on boot device 1441 -1 common/cmd_ide.c Image header has bad magic number 1442 1443 -1 common/cmd_nand.c Bad usage of "nand" command 1444 -1 common/cmd_nand.c No boot device 1445 -1 common/cmd_nand.c Unknown Chip ID on boot device 1446 -1 common/cmd_nand.c Read Error on boot device 1447 -1 common/cmd_nand.c Image header has bad magic number 1448 1449 -1 common/env_common.c Environment has a bad CRC, using default 1450 1451 1452Modem Support: 1453-------------- 1454 1455[so far only for SMDK2400 and TRAB boards] 1456 1457- Modem support endable: 1458 CONFIG_MODEM_SUPPORT 1459 1460- RTS/CTS Flow control enable: 1461 CONFIG_HWFLOW 1462 1463- Modem debug support: 1464 CONFIG_MODEM_SUPPORT_DEBUG 1465 1466 Enables debugging stuff (char screen[1024], dbg()) 1467 for modem support. Useful only with BDI2000. 1468 1469- Interrupt support (PPC): 1470 1471 There are common interrupt_init() and timer_interrupt() 1472 for all PPC archs. interrupt_init() calls interrupt_init_cpu() 1473 for cpu specific initialization. interrupt_init_cpu() 1474 should set decrementer_count to appropriate value. If 1475 cpu resets decrementer automatically after interrupt 1476 (ppc4xx) it should set decrementer_count to zero. 1477 timer_interrupt() calls timer_interrupt_cpu() for cpu 1478 specific handling. If board has watchdog / status_led 1479 / other_activity_monitor it works automatically from 1480 general timer_interrupt(). 1481 1482- General: 1483 1484 In the target system modem support is enabled when a 1485 specific key (key combination) is pressed during 1486 power-on. Otherwise U-Boot will boot normally 1487 (autoboot). The key_pressed() fuction is called from 1488 board_init(). Currently key_pressed() is a dummy 1489 function, returning 1 and thus enabling modem 1490 initialization. 1491 1492 If there are no modem init strings in the 1493 environment, U-Boot proceed to autoboot; the 1494 previous output (banner, info printfs) will be 1495 supressed, though. 1496 1497 See also: doc/README.Modem 1498 1499 1500Configuration Settings: 1501----------------------- 1502 1503- CFG_LONGHELP: Defined when you want long help messages included; 1504 undefine this when you're short of memory. 1505 1506- CFG_PROMPT: This is what U-Boot prints on the console to 1507 prompt for user input. 1508 1509- CFG_CBSIZE: Buffer size for input from the Console 1510 1511- CFG_PBSIZE: Buffer size for Console output 1512 1513- CFG_MAXARGS: max. Number of arguments accepted for monitor commands 1514 1515- CFG_BARGSIZE: Buffer size for Boot Arguments which are passed to 1516 the application (usually a Linux kernel) when it is 1517 booted 1518 1519- CFG_BAUDRATE_TABLE: 1520 List of legal baudrate settings for this board. 1521 1522- CFG_CONSOLE_INFO_QUIET 1523 Suppress display of console information at boot. 1524 1525- CFG_CONSOLE_IS_IN_ENV 1526 If the board specific function 1527 extern int overwrite_console (void); 1528 returns 1, the stdin, stderr and stdout are switched to the 1529 serial port, else the settings in the environment are used. 1530 1531- CFG_CONSOLE_OVERWRITE_ROUTINE 1532 Enable the call to overwrite_console(). 1533 1534- CFG_CONSOLE_ENV_OVERWRITE 1535 Enable overwrite of previous console environment settings. 1536 1537- CFG_MEMTEST_START, CFG_MEMTEST_END: 1538 Begin and End addresses of the area used by the 1539 simple memory test. 1540 1541- CFG_ALT_MEMTEST: 1542 Enable an alternate, more extensive memory test. 1543 1544- CFG_MEMTEST_SCRATCH: 1545 Scratch address used by the alternate memory test 1546 You only need to set this if address zero isn't writeable 1547 1548- CFG_TFTP_LOADADDR: 1549 Default load address for network file downloads 1550 1551- CFG_LOADS_BAUD_CHANGE: 1552 Enable temporary baudrate change while serial download 1553 1554- CFG_SDRAM_BASE: 1555 Physical start address of SDRAM. _Must_ be 0 here. 1556 1557- CFG_MBIO_BASE: 1558 Physical start address of Motherboard I/O (if using a 1559 Cogent motherboard) 1560 1561- CFG_FLASH_BASE: 1562 Physical start address of Flash memory. 1563 1564- CFG_MONITOR_BASE: 1565 Physical start address of boot monitor code (set by 1566 make config files to be same as the text base address 1567 (TEXT_BASE) used when linking) - same as 1568 CFG_FLASH_BASE when booting from flash. 1569 1570- CFG_MONITOR_LEN: 1571 Size of memory reserved for monitor code, used to 1572 determine _at_compile_time_ (!) if the environment is 1573 embedded within the U-Boot image, or in a separate 1574 flash sector. 1575 1576- CFG_MALLOC_LEN: 1577 Size of DRAM reserved for malloc() use. 1578 1579- CFG_BOOTMAPSZ: 1580 Maximum size of memory mapped by the startup code of 1581 the Linux kernel; all data that must be processed by 1582 the Linux kernel (bd_info, boot arguments, eventually 1583 initrd image) must be put below this limit. 1584 1585- CFG_MAX_FLASH_BANKS: 1586 Max number of Flash memory banks 1587 1588- CFG_MAX_FLASH_SECT: 1589 Max number of sectors on a Flash chip 1590 1591- CFG_FLASH_ERASE_TOUT: 1592 Timeout for Flash erase operations (in ms) 1593 1594- CFG_FLASH_WRITE_TOUT: 1595 Timeout for Flash write operations (in ms) 1596 1597- CFG_FLASH_LOCK_TOUT 1598 Timeout for Flash set sector lock bit operation (in ms) 1599 1600- CFG_FLASH_UNLOCK_TOUT 1601 Timeout for Flash clear lock bits operation (in ms) 1602 1603- CFG_FLASH_PROTECTION 1604 If defined, hardware flash sectors protection is used 1605 instead of U-Boot software protection. 1606 1607- CFG_DIRECT_FLASH_TFTP: 1608 1609 Enable TFTP transfers directly to flash memory; 1610 without this option such a download has to be 1611 performed in two steps: (1) download to RAM, and (2) 1612 copy from RAM to flash. 1613 1614 The two-step approach is usually more reliable, since 1615 you can check if the download worked before you erase 1616 the flash, but in some situations (when sytem RAM is 1617 too limited to allow for a tempory copy of the 1618 downloaded image) this option may be very useful. 1619 1620- CFG_FLASH_CFI: 1621 Define if the flash driver uses extra elements in the 1622 common flash structure for storing flash geometry 1623 1624- CFG_RX_ETH_BUFFER: 1625 Defines the number of ethernet receive buffers. On some 1626 ethernet controllers it is recommended to set this value 1627 to 8 or even higher (EEPRO100 or 405 EMAC), since all 1628 buffers can be full shortly after enabling the interface 1629 on high ethernet traffic. 1630 Defaults to 4 if not defined. 1631 1632The following definitions that deal with the placement and management 1633of environment data (variable area); in general, we support the 1634following configurations: 1635 1636- CFG_ENV_IS_IN_FLASH: 1637 1638 Define this if the environment is in flash memory. 1639 1640 a) The environment occupies one whole flash sector, which is 1641 "embedded" in the text segment with the U-Boot code. This 1642 happens usually with "bottom boot sector" or "top boot 1643 sector" type flash chips, which have several smaller 1644 sectors at the start or the end. For instance, such a 1645 layout can have sector sizes of 8, 2x4, 16, Nx32 kB. In 1646 such a case you would place the environment in one of the 1647 4 kB sectors - with U-Boot code before and after it. With 1648 "top boot sector" type flash chips, you would put the 1649 environment in one of the last sectors, leaving a gap 1650 between U-Boot and the environment. 1651 1652 - CFG_ENV_OFFSET: 1653 1654 Offset of environment data (variable area) to the 1655 beginning of flash memory; for instance, with bottom boot 1656 type flash chips the second sector can be used: the offset 1657 for this sector is given here. 1658 1659 CFG_ENV_OFFSET is used relative to CFG_FLASH_BASE. 1660 1661 - CFG_ENV_ADDR: 1662 1663 This is just another way to specify the start address of 1664 the flash sector containing the environment (instead of 1665 CFG_ENV_OFFSET). 1666 1667 - CFG_ENV_SECT_SIZE: 1668 1669 Size of the sector containing the environment. 1670 1671 1672 b) Sometimes flash chips have few, equal sized, BIG sectors. 1673 In such a case you don't want to spend a whole sector for 1674 the environment. 1675 1676 - CFG_ENV_SIZE: 1677 1678 If you use this in combination with CFG_ENV_IS_IN_FLASH 1679 and CFG_ENV_SECT_SIZE, you can specify to use only a part 1680 of this flash sector for the environment. This saves 1681 memory for the RAM copy of the environment. 1682 1683 It may also save flash memory if you decide to use this 1684 when your environment is "embedded" within U-Boot code, 1685 since then the remainder of the flash sector could be used 1686 for U-Boot code. It should be pointed out that this is 1687 STRONGLY DISCOURAGED from a robustness point of view: 1688 updating the environment in flash makes it always 1689 necessary to erase the WHOLE sector. If something goes 1690 wrong before the contents has been restored from a copy in 1691 RAM, your target system will be dead. 1692 1693 - CFG_ENV_ADDR_REDUND 1694 CFG_ENV_SIZE_REDUND 1695 1696 These settings describe a second storage area used to hold 1697 a redundand copy of the environment data, so that there is 1698 a valid backup copy in case there is a power failure during 1699 a "saveenv" operation. 1700 1701BE CAREFUL! Any changes to the flash layout, and some changes to the 1702source code will make it necessary to adapt <board>/u-boot.lds* 1703accordingly! 1704 1705 1706- CFG_ENV_IS_IN_NVRAM: 1707 1708 Define this if you have some non-volatile memory device 1709 (NVRAM, battery buffered SRAM) which you want to use for the 1710 environment. 1711 1712 - CFG_ENV_ADDR: 1713 - CFG_ENV_SIZE: 1714 1715 These two #defines are used to determin the memory area you 1716 want to use for environment. It is assumed that this memory 1717 can just be read and written to, without any special 1718 provision. 1719 1720BE CAREFUL! The first access to the environment happens quite early 1721in U-Boot initalization (when we try to get the setting of for the 1722console baudrate). You *MUST* have mappend your NVRAM area then, or 1723U-Boot will hang. 1724 1725Please note that even with NVRAM we still use a copy of the 1726environment in RAM: we could work on NVRAM directly, but we want to 1727keep settings there always unmodified except somebody uses "saveenv" 1728to save the current settings. 1729 1730 1731- CFG_ENV_IS_IN_EEPROM: 1732 1733 Use this if you have an EEPROM or similar serial access 1734 device and a driver for it. 1735 1736 - CFG_ENV_OFFSET: 1737 - CFG_ENV_SIZE: 1738 1739 These two #defines specify the offset and size of the 1740 environment area within the total memory of your EEPROM. 1741 1742 - CFG_I2C_EEPROM_ADDR: 1743 If defined, specified the chip address of the EEPROM device. 1744 The default address is zero. 1745 1746 - CFG_EEPROM_PAGE_WRITE_BITS: 1747 If defined, the number of bits used to address bytes in a 1748 single page in the EEPROM device. A 64 byte page, for example 1749 would require six bits. 1750 1751 - CFG_EEPROM_PAGE_WRITE_DELAY_MS: 1752 If defined, the number of milliseconds to delay between 1753 page writes. The default is zero milliseconds. 1754 1755 - CFG_I2C_EEPROM_ADDR_LEN: 1756 The length in bytes of the EEPROM memory array address. Note 1757 that this is NOT the chip address length! 1758 1759 - CFG_EEPROM_SIZE: 1760 The size in bytes of the EEPROM device. 1761 1762 1763- CFG_ENV_IS_IN_DATAFLASH: 1764 1765 Define this if you have a DataFlash memory device which you 1766 want to use for the environment. 1767 1768 - CFG_ENV_OFFSET: 1769 - CFG_ENV_ADDR: 1770 - CFG_ENV_SIZE: 1771 1772 These three #defines specify the offset and size of the 1773 environment area within the total memory of your DataFlash placed 1774 at the specified address. 1775 1776 1777- CFG_SPI_INIT_OFFSET 1778 1779 Defines offset to the initial SPI buffer area in DPRAM. The 1780 area is used at an early stage (ROM part) if the environment 1781 is configured to reside in the SPI EEPROM: We need a 520 byte 1782 scratch DPRAM area. It is used between the two initialization 1783 calls (spi_init_f() and spi_init_r()). A value of 0xB00 seems 1784 to be a good choice since it makes it far enough from the 1785 start of the data area as well as from the stack pointer. 1786 1787Please note that the environment is read-only as long as the monitor 1788has been relocated to RAM and a RAM copy of the environment has been 1789created; also, when using EEPROM you will have to use getenv_r() 1790until then to read environment variables. 1791 1792The environment is protected by a CRC32 checksum. Before the monitor 1793is relocated into RAM, as a result of a bad CRC you will be working 1794with the compiled-in default environment - *silently*!!! [This is 1795necessary, because the first environment variable we need is the 1796"baudrate" setting for the console - if we have a bad CRC, we don't 1797have any device yet where we could complain.] 1798 1799Note: once the monitor has been relocated, then it will complain if 1800the default environment is used; a new CRC is computed as soon as you 1801use the "saveenv" command to store a valid environment. 1802 1803- CFG_FAULT_ECHO_LINK_DOWN: 1804 Echo the inverted Ethernet link state to the fault LED. 1805 1806 Note: If this option is active, then CFG_FAULT_MII_ADDR 1807 also needs to be defined. 1808 1809- CFG_FAULT_MII_ADDR: 1810 MII address of the PHY to check for the Ethernet link state. 1811 1812Low Level (hardware related) configuration options: 1813--------------------------------------------------- 1814 1815- CFG_CACHELINE_SIZE: 1816 Cache Line Size of the CPU. 1817 1818- CFG_DEFAULT_IMMR: 1819 Default address of the IMMR after system reset. 1820 1821 Needed on some 8260 systems (MPC8260ADS, PQ2FADS-ZU, 1822 and RPXsuper) to be able to adjust the position of 1823 the IMMR register after a reset. 1824 1825- Floppy Disk Support: 1826 CFG_FDC_DRIVE_NUMBER 1827 1828 the default drive number (default value 0) 1829 1830 CFG_ISA_IO_STRIDE 1831 1832 defines the spacing between fdc chipset registers 1833 (default value 1) 1834 1835 CFG_ISA_IO_OFFSET 1836 1837 defines the offset of register from address. It 1838 depends on which part of the data bus is connected to 1839 the fdc chipset. (default value 0) 1840 1841 If CFG_ISA_IO_STRIDE CFG_ISA_IO_OFFSET and 1842 CFG_FDC_DRIVE_NUMBER are undefined, they take their 1843 default value. 1844 1845 if CFG_FDC_HW_INIT is defined, then the function 1846 fdc_hw_init() is called at the beginning of the FDC 1847 setup. fdc_hw_init() must be provided by the board 1848 source code. It is used to make hardware dependant 1849 initializations. 1850 1851- CFG_IMMR: Physical address of the Internal Memory Mapped 1852 Register; DO NOT CHANGE! (11-4) 1853 [MPC8xx systems only] 1854 1855- CFG_INIT_RAM_ADDR: 1856 1857 Start address of memory area that can be used for 1858 initial data and stack; please note that this must be 1859 writable memory that is working WITHOUT special 1860 initialization, i. e. you CANNOT use normal RAM which 1861 will become available only after programming the 1862 memory controller and running certain initialization 1863 sequences. 1864 1865 U-Boot uses the following memory types: 1866 - MPC8xx and MPC8260: IMMR (internal memory of the CPU) 1867 - MPC824X: data cache 1868 - PPC4xx: data cache 1869 1870- CFG_GBL_DATA_OFFSET: 1871 1872 Offset of the initial data structure in the memory 1873 area defined by CFG_INIT_RAM_ADDR. Usually 1874 CFG_GBL_DATA_OFFSET is chosen such that the initial 1875 data is located at the end of the available space 1876 (sometimes written as (CFG_INIT_RAM_END - 1877 CFG_INIT_DATA_SIZE), and the initial stack is just 1878 below that area (growing from (CFG_INIT_RAM_ADDR + 1879 CFG_GBL_DATA_OFFSET) downward. 1880 1881 Note: 1882 On the MPC824X (or other systems that use the data 1883 cache for initial memory) the address chosen for 1884 CFG_INIT_RAM_ADDR is basically arbitrary - it must 1885 point to an otherwise UNUSED address space between 1886 the top of RAM and the start of the PCI space. 1887 1888- CFG_SIUMCR: SIU Module Configuration (11-6) 1889 1890- CFG_SYPCR: System Protection Control (11-9) 1891 1892- CFG_TBSCR: Time Base Status and Control (11-26) 1893 1894- CFG_PISCR: Periodic Interrupt Status and Control (11-31) 1895 1896- CFG_PLPRCR: PLL, Low-Power, and Reset Control Register (15-30) 1897 1898- CFG_SCCR: System Clock and reset Control Register (15-27) 1899 1900- CFG_OR_TIMING_SDRAM: 1901 SDRAM timing 1902 1903- CFG_MAMR_PTA: 1904 periodic timer for refresh 1905 1906- CFG_DER: Debug Event Register (37-47) 1907 1908- FLASH_BASE0_PRELIM, FLASH_BASE1_PRELIM, CFG_REMAP_OR_AM, 1909 CFG_PRELIM_OR_AM, CFG_OR_TIMING_FLASH, CFG_OR0_REMAP, 1910 CFG_OR0_PRELIM, CFG_BR0_PRELIM, CFG_OR1_REMAP, CFG_OR1_PRELIM, 1911 CFG_BR1_PRELIM: 1912 Memory Controller Definitions: BR0/1 and OR0/1 (FLASH) 1913 1914- SDRAM_BASE2_PRELIM, SDRAM_BASE3_PRELIM, SDRAM_MAX_SIZE, 1915 CFG_OR_TIMING_SDRAM, CFG_OR2_PRELIM, CFG_BR2_PRELIM, 1916 CFG_OR3_PRELIM, CFG_BR3_PRELIM: 1917 Memory Controller Definitions: BR2/3 and OR2/3 (SDRAM) 1918 1919- CFG_MAMR_PTA, CFG_MPTPR_2BK_4K, CFG_MPTPR_1BK_4K, CFG_MPTPR_2BK_8K, 1920 CFG_MPTPR_1BK_8K, CFG_MAMR_8COL, CFG_MAMR_9COL: 1921 Machine Mode Register and Memory Periodic Timer 1922 Prescaler definitions (SDRAM timing) 1923 1924- CFG_I2C_UCODE_PATCH, CFG_I2C_DPMEM_OFFSET [0x1FC0]: 1925 enable I2C microcode relocation patch (MPC8xx); 1926 define relocation offset in DPRAM [DSP2] 1927 1928- CFG_SPI_UCODE_PATCH, CFG_SPI_DPMEM_OFFSET [0x1FC0]: 1929 enable SPI microcode relocation patch (MPC8xx); 1930 define relocation offset in DPRAM [SCC4] 1931 1932- CFG_USE_OSCCLK: 1933 Use OSCM clock mode on MBX8xx board. Be careful, 1934 wrong setting might damage your board. Read 1935 doc/README.MBX before setting this variable! 1936 1937- CFG_CPM_POST_WORD_ADDR: (MPC8xx, MPC8260 only) 1938 Offset of the bootmode word in DPRAM used by post 1939 (Power On Self Tests). This definition overrides 1940 #define'd default value in commproc.h resp. 1941 cpm_8260.h. 1942 1943- CFG_PCI_SLV_MEM_LOCAL, CFG_PCI_SLV_MEM_BUS, CFG_PICMR0_MASK_ATTRIB, 1944 CFG_PCI_MSTR0_LOCAL, CFG_PCIMSK0_MASK, CFG_PCI_MSTR1_LOCAL, 1945 CFG_PCIMSK1_MASK, CFG_PCI_MSTR_MEM_LOCAL, CFG_PCI_MSTR_MEM_BUS, 1946 CFG_CPU_PCI_MEM_START, CFG_PCI_MSTR_MEM_SIZE, CFG_POCMR0_MASK_ATTRIB, 1947 CFG_PCI_MSTR_MEMIO_LOCAL, CFG_PCI_MSTR_MEMIO_BUS, CPU_PCI_MEMIO_START, 1948 CFG_PCI_MSTR_MEMIO_SIZE, CFG_POCMR1_MASK_ATTRIB, CFG_PCI_MSTR_IO_LOCAL, 1949 CFG_PCI_MSTR_IO_BUS, CFG_CPU_PCI_IO_START, CFG_PCI_MSTR_IO_SIZE, 1950 CFG_POCMR2_MASK_ATTRIB: (MPC826x only) 1951 Overrides the default PCI memory map in cpu/mpc8260/pci.c if set. 1952 1953Building the Software: 1954====================== 1955 1956Building U-Boot has been tested in native PPC environments (on a 1957PowerBook G3 running LinuxPPC 2000) and in cross environments 1958(running RedHat 6.x and 7.x Linux on x86, Solaris 2.6 on a SPARC, and 1959NetBSD 1.5 on x86). 1960 1961If you are not using a native PPC environment, it is assumed that you 1962have the GNU cross compiling tools available in your path and named 1963with a prefix of "powerpc-linux-". If this is not the case, (e.g. if 1964you are using Monta Vista's Hard Hat Linux CDK 1.2) you must change 1965the definition of CROSS_COMPILE in Makefile. For HHL on a 4xx CPU, 1966change it to: 1967 1968 CROSS_COMPILE = ppc_4xx- 1969 1970 1971U-Boot is intended to be simple to build. After installing the 1972sources you must configure U-Boot for one specific board type. This 1973is done by typing: 1974 1975 make NAME_config 1976 1977where "NAME_config" is the name of one of the existing 1978configurations; the following names are supported: 1979 1980 ADCIOP_config GTH_config TQM850L_config 1981 ADS860_config IP860_config TQM855L_config 1982 AR405_config IVML24_config TQM860L_config 1983 CANBT_config IVMS8_config WALNUT405_config 1984 CPCI405_config LANTEC_config cogent_common_config 1985 CPCIISER4_config MBX_config cogent_mpc8260_config 1986 CU824_config MBX860T_config cogent_mpc8xx_config 1987 ESTEEM192E_config RPXlite_config hermes_config 1988 ETX094_config RPXsuper_config hymod_config 1989 FADS823_config SM850_config lwmon_config 1990 FADS850SAR_config SPD823TS_config pcu_e_config 1991 FADS860T_config SXNI855T_config rsdproto_config 1992 FPS850L_config Sandpoint8240_config sbc8260_config 1993 GENIETV_config TQM823L_config PIP405_config 1994 GEN860T_config EBONY_config FPS860L_config 1995 ELPT860_config cmi_mpc5xx_config NETVIA_config 1996 at91rm9200dk_config omap1510inn_config MPC8260ADS_config 1997 omap1610inn_config ZPC1900_config MPC8540ADS_config 1998 MPC8560ADS_config 1999 2000Note: for some board special configuration names may exist; check if 2001 additional information is available from the board vendor; for 2002 instance, the TQM8xxL systems run normally at 50 MHz and use a 2003 SCC for 10baseT ethernet; there are also systems with 80 MHz 2004 CPU clock, and an optional Fast Ethernet module is available 2005 for CPU's with FEC. You can select such additional "features" 2006 when chosing the configuration, i. e. 2007 2008 make TQM860L_config 2009 - will configure for a plain TQM860L, i. e. 50MHz, no FEC 2010 2011 make TQM860L_FEC_config 2012 - will configure for a TQM860L at 50MHz with FEC for ethernet 2013 2014 make TQM860L_80MHz_config 2015 - will configure for a TQM860L at 80 MHz, with normal 10baseT 2016 interface 2017 2018 make TQM860L_FEC_80MHz_config 2019 - will configure for a TQM860L at 80 MHz with FEC for ethernet 2020 2021 make TQM823L_LCD_config 2022 - will configure for a TQM823L with U-Boot console on LCD 2023 2024 make TQM823L_LCD_80MHz_config 2025 - will configure for a TQM823L at 80 MHz with U-Boot console on LCD 2026 2027 etc. 2028 2029 2030Finally, type "make all", and you should get some working U-Boot 2031images ready for download to / installation on your system: 2032 2033- "u-boot.bin" is a raw binary image 2034- "u-boot" is an image in ELF binary format 2035- "u-boot.srec" is in Motorola S-Record format 2036 2037 2038Please be aware that the Makefiles assume you are using GNU make, so 2039for instance on NetBSD you might need to use "gmake" instead of 2040native "make". 2041 2042 2043If the system board that you have is not listed, then you will need 2044to port U-Boot to your hardware platform. To do this, follow these 2045steps: 2046 20471. Add a new configuration option for your board to the toplevel 2048 "Makefile" and to the "MAKEALL" script, using the existing 2049 entries as examples. Note that here and at many other places 2050 boards and other names are listed in alphabetical sort order. Please 2051 keep this order. 20522. Create a new directory to hold your board specific code. Add any 2053 files you need. In your board directory, you will need at least 2054 the "Makefile", a "<board>.c", "flash.c" and "u-boot.lds". 20553. Create a new configuration file "include/configs/<board>.h" for 2056 your board 20573. If you're porting U-Boot to a new CPU, then also create a new 2058 directory to hold your CPU specific code. Add any files you need. 20594. Run "make <board>_config" with your new name. 20605. Type "make", and you should get a working "u-boot.srec" file 2061 to be installed on your target system. 20626. Debug and solve any problems that might arise. 2063 [Of course, this last step is much harder than it sounds.] 2064 2065 2066Testing of U-Boot Modifications, Ports to New Hardware, etc.: 2067============================================================== 2068 2069If you have modified U-Boot sources (for instance added a new board 2070or support for new devices, a new CPU, etc.) you are expected to 2071provide feedback to the other developers. The feedback normally takes 2072the form of a "patch", i. e. a context diff against a certain (latest 2073official or latest in CVS) version of U-Boot sources. 2074 2075But before you submit such a patch, please verify that your modifi- 2076cation did not break existing code. At least make sure that *ALL* of 2077the supported boards compile WITHOUT ANY compiler warnings. To do so, 2078just run the "MAKEALL" script, which will configure and build U-Boot 2079for ALL supported system. Be warned, this will take a while. You can 2080select which (cross) compiler to use by passing a `CROSS_COMPILE' 2081environment variable to the script, i. e. to use the cross tools from 2082MontaVista's Hard Hat Linux you can type 2083 2084 CROSS_COMPILE=ppc_8xx- MAKEALL 2085 2086or to build on a native PowerPC system you can type 2087 2088 CROSS_COMPILE=' ' MAKEALL 2089 2090See also "U-Boot Porting Guide" below. 2091 2092 2093Monitor Commands - Overview: 2094============================ 2095 2096go - start application at address 'addr' 2097run - run commands in an environment variable 2098bootm - boot application image from memory 2099bootp - boot image via network using BootP/TFTP protocol 2100tftpboot- boot image via network using TFTP protocol 2101 and env variables "ipaddr" and "serverip" 2102 (and eventually "gatewayip") 2103rarpboot- boot image via network using RARP/TFTP protocol 2104diskboot- boot from IDE devicebootd - boot default, i.e., run 'bootcmd' 2105loads - load S-Record file over serial line 2106loadb - load binary file over serial line (kermit mode) 2107md - memory display 2108mm - memory modify (auto-incrementing) 2109nm - memory modify (constant address) 2110mw - memory write (fill) 2111cp - memory copy 2112cmp - memory compare 2113crc32 - checksum calculation 2114imd - i2c memory display 2115imm - i2c memory modify (auto-incrementing) 2116inm - i2c memory modify (constant address) 2117imw - i2c memory write (fill) 2118icrc32 - i2c checksum calculation 2119iprobe - probe to discover valid I2C chip addresses 2120iloop - infinite loop on address range 2121isdram - print SDRAM configuration information 2122sspi - SPI utility commands 2123base - print or set address offset 2124printenv- print environment variables 2125setenv - set environment variables 2126saveenv - save environment variables to persistent storage 2127protect - enable or disable FLASH write protection 2128erase - erase FLASH memory 2129flinfo - print FLASH memory information 2130bdinfo - print Board Info structure 2131iminfo - print header information for application image 2132coninfo - print console devices and informations 2133ide - IDE sub-system 2134loop - infinite loop on address range 2135mtest - simple RAM test 2136icache - enable or disable instruction cache 2137dcache - enable or disable data cache 2138reset - Perform RESET of the CPU 2139echo - echo args to console 2140version - print monitor version 2141help - print online help 2142? - alias for 'help' 2143 2144 2145Monitor Commands - Detailed Description: 2146======================================== 2147 2148TODO. 2149 2150For now: just type "help <command>". 2151 2152 2153Environment Variables: 2154====================== 2155 2156U-Boot supports user configuration using Environment Variables which 2157can be made persistent by saving to Flash memory. 2158 2159Environment Variables are set using "setenv", printed using 2160"printenv", and saved to Flash using "saveenv". Using "setenv" 2161without a value can be used to delete a variable from the 2162environment. As long as you don't save the environment you are 2163working with an in-memory copy. In case the Flash area containing the 2164environment is erased by accident, a default environment is provided. 2165 2166Some configuration options can be set using Environment Variables: 2167 2168 baudrate - see CONFIG_BAUDRATE 2169 2170 bootdelay - see CONFIG_BOOTDELAY 2171 2172 bootcmd - see CONFIG_BOOTCOMMAND 2173 2174 bootargs - Boot arguments when booting an RTOS image 2175 2176 bootfile - Name of the image to load with TFTP 2177 2178 autoload - if set to "no" (any string beginning with 'n'), 2179 "bootp" will just load perform a lookup of the 2180 configuration from the BOOTP server, but not try to 2181 load any image using TFTP 2182 2183 autostart - if set to "yes", an image loaded using the "bootp", 2184 "rarpboot", "tftpboot" or "diskboot" commands will 2185 be automatically started (by internally calling 2186 "bootm") 2187 2188 If set to "no", a standalone image passed to the 2189 "bootm" command will be copied to the load address 2190 (and eventually uncompressed), but NOT be started. 2191 This can be used to load and uncompress arbitrary 2192 data. 2193 2194 initrd_high - restrict positioning of initrd images: 2195 If this variable is not set, initrd images will be 2196 copied to the highest possible address in RAM; this 2197 is usually what you want since it allows for 2198 maximum initrd size. If for some reason you want to 2199 make sure that the initrd image is loaded below the 2200 CFG_BOOTMAPSZ limit, you can set this environment 2201 variable to a value of "no" or "off" or "0". 2202 Alternatively, you can set it to a maximum upper 2203 address to use (U-Boot will still check that it 2204 does not overwrite the U-Boot stack and data). 2205 2206 For instance, when you have a system with 16 MB 2207 RAM, and want to reserve 4 MB from use by Linux, 2208 you can do this by adding "mem=12M" to the value of 2209 the "bootargs" variable. However, now you must make 2210 sure that the initrd image is placed in the first 2211 12 MB as well - this can be done with 2212 2213 setenv initrd_high 00c00000 2214 2215 If you set initrd_high to 0xFFFFFFFF, this is an 2216 indication to U-Boot that all addresses are legal 2217 for the Linux kernel, including addresses in flash 2218 memory. In this case U-Boot will NOT COPY the 2219 ramdisk at all. This may be useful to reduce the 2220 boot time on your system, but requires that this 2221 feature is supported by your Linux kernel. 2222 2223 ipaddr - IP address; needed for tftpboot command 2224 2225 loadaddr - Default load address for commands like "bootp", 2226 "rarpboot", "tftpboot", "loadb" or "diskboot" 2227 2228 loads_echo - see CONFIG_LOADS_ECHO 2229 2230 serverip - TFTP server IP address; needed for tftpboot command 2231 2232 bootretry - see CONFIG_BOOT_RETRY_TIME 2233 2234 bootdelaykey - see CONFIG_AUTOBOOT_DELAY_STR 2235 2236 bootstopkey - see CONFIG_AUTOBOOT_STOP_STR 2237 2238 2239The following environment variables may be used and automatically 2240updated by the network boot commands ("bootp" and "rarpboot"), 2241depending the information provided by your boot server: 2242 2243 bootfile - see above 2244 dnsip - IP address of your Domain Name Server 2245 dnsip2 - IP address of your secondary Domain Name Server 2246 gatewayip - IP address of the Gateway (Router) to use 2247 hostname - Target hostname 2248 ipaddr - see above 2249 netmask - Subnet Mask 2250 rootpath - Pathname of the root filesystem on the NFS server 2251 serverip - see above 2252 2253 2254There are two special Environment Variables: 2255 2256 serial# - contains hardware identification information such 2257 as type string and/or serial number 2258 ethaddr - Ethernet address 2259 2260These variables can be set only once (usually during manufacturing of 2261the board). U-Boot refuses to delete or overwrite these variables 2262once they have been set once. 2263 2264 2265Further special Environment Variables: 2266 2267 ver - Contains the U-Boot version string as printed 2268 with the "version" command. This variable is 2269 readonly (see CONFIG_VERSION_VARIABLE). 2270 2271 2272Please note that changes to some configuration parameters may take 2273only effect after the next boot (yes, that's just like Windoze :-). 2274 2275 2276Command Line Parsing: 2277===================== 2278 2279There are two different command line parsers available with U-Boot: 2280the old "simple" one, and the much more powerful "hush" shell: 2281 2282Old, simple command line parser: 2283-------------------------------- 2284 2285- supports environment variables (through setenv / saveenv commands) 2286- several commands on one line, separated by ';' 2287- variable substitution using "... $(name) ..." syntax 2288- special characters ('$', ';') can be escaped by prefixing with '\', 2289 for example: 2290 setenv bootcmd bootm \$(address) 2291- You can also escape text by enclosing in single apostrophes, for example: 2292 setenv addip 'setenv bootargs $bootargs ip=$ipaddr:$serverip:$gatewayip:$netmask:$hostname::off' 2293 2294Hush shell: 2295----------- 2296 2297- similar to Bourne shell, with control structures like 2298 if...then...else...fi, for...do...done; while...do...done, 2299 until...do...done, ... 2300- supports environment ("global") variables (through setenv / saveenv 2301 commands) and local shell variables (through standard shell syntax 2302 "name=value"); only environment variables can be used with "run" 2303 command 2304 2305General rules: 2306-------------- 2307 2308(1) If a command line (or an environment variable executed by a "run" 2309 command) contains several commands separated by semicolon, and 2310 one of these commands fails, then the remaining commands will be 2311 executed anyway. 2312 2313(2) If you execute several variables with one call to run (i. e. 2314 calling run with a list af variables as arguments), any failing 2315 command will cause "run" to terminate, i. e. the remaining 2316 variables are not executed. 2317 2318Note for Redundant Ethernet Interfaces: 2319======================================= 2320 2321Some boards come with redundant ethernet interfaces; U-Boot supports 2322such configurations and is capable of automatic selection of a 2323"working" interface when needed. MAC assignment works as follows: 2324 2325Network interfaces are numbered eth0, eth1, eth2, ... Corresponding 2326MAC addresses can be stored in the environment as "ethaddr" (=>eth0), 2327"eth1addr" (=>eth1), "eth2addr", ... 2328 2329If the network interface stores some valid MAC address (for instance 2330in SROM), this is used as default address if there is NO correspon- 2331ding setting in the environment; if the corresponding environment 2332variable is set, this overrides the settings in the card; that means: 2333 2334o If the SROM has a valid MAC address, and there is no address in the 2335 environment, the SROM's address is used. 2336 2337o If there is no valid address in the SROM, and a definition in the 2338 environment exists, then the value from the environment variable is 2339 used. 2340 2341o If both the SROM and the environment contain a MAC address, and 2342 both addresses are the same, this MAC address is used. 2343 2344o If both the SROM and the environment contain a MAC address, and the 2345 addresses differ, the value from the environment is used and a 2346 warning is printed. 2347 2348o If neither SROM nor the environment contain a MAC address, an error 2349 is raised. 2350 2351 2352Image Formats: 2353============== 2354 2355The "boot" commands of this monitor operate on "image" files which 2356can be basicly anything, preceeded by a special header; see the 2357definitions in include/image.h for details; basicly, the header 2358defines the following image properties: 2359 2360* Target Operating System (Provisions for OpenBSD, NetBSD, FreeBSD, 2361 4.4BSD, Linux, SVR4, Esix, Solaris, Irix, SCO, Dell, NCR, VxWorks, 2362 LynxOS, pSOS, QNX, RTEMS, ARTOS; 2363 Currently supported: Linux, NetBSD, VxWorks, QNX, RTEMS, ARTOS, LynxOS). 2364* Target CPU Architecture (Provisions for Alpha, ARM, Intel x86, 2365 IA64, MIPS, NIOS, PowerPC, IBM S390, SuperH, Sparc, Sparc 64 Bit; 2366 Currently supported: ARM, Intel x86, MIPS, NIOS, PowerPC). 2367* Compression Type (uncompressed, gzip, bzip2) 2368* Load Address 2369* Entry Point 2370* Image Name 2371* Image Timestamp 2372 2373The header is marked by a special Magic Number, and both the header 2374and the data portions of the image are secured against corruption by 2375CRC32 checksums. 2376 2377 2378Linux Support: 2379============== 2380 2381Although U-Boot should support any OS or standalone application 2382easily, the main focus has always been on Linux during the design of 2383U-Boot. 2384 2385U-Boot includes many features that so far have been part of some 2386special "boot loader" code within the Linux kernel. Also, any 2387"initrd" images to be used are no longer part of one big Linux image; 2388instead, kernel and "initrd" are separate images. This implementation 2389serves several purposes: 2390 2391- the same features can be used for other OS or standalone 2392 applications (for instance: using compressed images to reduce the 2393 Flash memory footprint) 2394 2395- it becomes much easier to port new Linux kernel versions because 2396 lots of low-level, hardware dependent stuff are done by U-Boot 2397 2398- the same Linux kernel image can now be used with different "initrd" 2399 images; of course this also means that different kernel images can 2400 be run with the same "initrd". This makes testing easier (you don't 2401 have to build a new "zImage.initrd" Linux image when you just 2402 change a file in your "initrd"). Also, a field-upgrade of the 2403 software is easier now. 2404 2405 2406Linux HOWTO: 2407============ 2408 2409Porting Linux to U-Boot based systems: 2410--------------------------------------- 2411 2412U-Boot cannot save you from doing all the necessary modifications to 2413configure the Linux device drivers for use with your target hardware 2414(no, we don't intend to provide a full virtual machine interface to 2415Linux :-). 2416 2417But now you can ignore ALL boot loader code (in arch/ppc/mbxboot). 2418 2419Just make sure your machine specific header file (for instance 2420include/asm-ppc/tqm8xx.h) includes the same definition of the Board 2421Information structure as we define in include/u-boot.h, and make 2422sure that your definition of IMAP_ADDR uses the same value as your 2423U-Boot configuration in CFG_IMMR. 2424 2425 2426Configuring the Linux kernel: 2427----------------------------- 2428 2429No specific requirements for U-Boot. Make sure you have some root 2430device (initial ramdisk, NFS) for your target system. 2431 2432 2433Building a Linux Image: 2434----------------------- 2435 2436With U-Boot, "normal" build targets like "zImage" or "bzImage" are 2437not used. If you use recent kernel source, a new build target 2438"uImage" will exist which automatically builds an image usable by 2439U-Boot. Most older kernels also have support for a "pImage" target, 2440which was introduced for our predecessor project PPCBoot and uses a 2441100% compatible format. 2442 2443Example: 2444 2445 make TQM850L_config 2446 make oldconfig 2447 make dep 2448 make uImage 2449 2450The "uImage" build target uses a special tool (in 'tools/mkimage') to 2451encapsulate a compressed Linux kernel image with header information, 2452CRC32 checksum etc. for use with U-Boot. This is what we are doing: 2453 2454* build a standard "vmlinux" kernel image (in ELF binary format): 2455 2456* convert the kernel into a raw binary image: 2457 2458 ${CROSS_COMPILE}-objcopy -O binary \ 2459 -R .note -R .comment \ 2460 -S vmlinux linux.bin 2461 2462* compress the binary image: 2463 2464 gzip -9 linux.bin 2465 2466* package compressed binary image for U-Boot: 2467 2468 mkimage -A ppc -O linux -T kernel -C gzip \ 2469 -a 0 -e 0 -n "Linux Kernel Image" \ 2470 -d linux.bin.gz uImage 2471 2472 2473The "mkimage" tool can also be used to create ramdisk images for use 2474with U-Boot, either separated from the Linux kernel image, or 2475combined into one file. "mkimage" encapsulates the images with a 64 2476byte header containing information about target architecture, 2477operating system, image type, compression method, entry points, time 2478stamp, CRC32 checksums, etc. 2479 2480"mkimage" can be called in two ways: to verify existing images and 2481print the header information, or to build new images. 2482 2483In the first form (with "-l" option) mkimage lists the information 2484contained in the header of an existing U-Boot image; this includes 2485checksum verification: 2486 2487 tools/mkimage -l image 2488 -l ==> list image header information 2489 2490The second form (with "-d" option) is used to build a U-Boot image 2491from a "data file" which is used as image payload: 2492 2493 tools/mkimage -A arch -O os -T type -C comp -a addr -e ep \ 2494 -n name -d data_file image 2495 -A ==> set architecture to 'arch' 2496 -O ==> set operating system to 'os' 2497 -T ==> set image type to 'type' 2498 -C ==> set compression type 'comp' 2499 -a ==> set load address to 'addr' (hex) 2500 -e ==> set entry point to 'ep' (hex) 2501 -n ==> set image name to 'name' 2502 -d ==> use image data from 'datafile' 2503 2504Right now, all Linux kernels use the same load address (0x00000000), 2505but the entry point address depends on the kernel version: 2506 2507- 2.2.x kernels have the entry point at 0x0000000C, 2508- 2.3.x and later kernels have the entry point at 0x00000000. 2509 2510So a typical call to build a U-Boot image would read: 2511 2512 -> tools/mkimage -n '2.4.4 kernel for TQM850L' \ 2513 > -A ppc -O linux -T kernel -C gzip -a 0 -e 0 \ 2514 > -d /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/ppc/coffboot/vmlinux.gz \ 2515 > examples/uImage.TQM850L 2516 Image Name: 2.4.4 kernel for TQM850L 2517 Created: Wed Jul 19 02:34:59 2000 2518 Image Type: PowerPC Linux Kernel Image (gzip compressed) 2519 Data Size: 335725 Bytes = 327.86 kB = 0.32 MB 2520 Load Address: 0x00000000 2521 Entry Point: 0x00000000 2522 2523To verify the contents of the image (or check for corruption): 2524 2525 -> tools/mkimage -l examples/uImage.TQM850L 2526 Image Name: 2.4.4 kernel for TQM850L 2527 Created: Wed Jul 19 02:34:59 2000 2528 Image Type: PowerPC Linux Kernel Image (gzip compressed) 2529 Data Size: 335725 Bytes = 327.86 kB = 0.32 MB 2530 Load Address: 0x00000000 2531 Entry Point: 0x00000000 2532 2533NOTE: for embedded systems where boot time is critical you can trade 2534speed for memory and install an UNCOMPRESSED image instead: this 2535needs more space in Flash, but boots much faster since it does not 2536need to be uncompressed: 2537 2538 -> gunzip /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/ppc/coffboot/vmlinux.gz 2539 -> tools/mkimage -n '2.4.4 kernel for TQM850L' \ 2540 > -A ppc -O linux -T kernel -C none -a 0 -e 0 \ 2541 > -d /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/ppc/coffboot/vmlinux \ 2542 > examples/uImage.TQM850L-uncompressed 2543 Image Name: 2.4.4 kernel for TQM850L 2544 Created: Wed Jul 19 02:34:59 2000 2545 Image Type: PowerPC Linux Kernel Image (uncompressed) 2546 Data Size: 792160 Bytes = 773.59 kB = 0.76 MB 2547 Load Address: 0x00000000 2548 Entry Point: 0x00000000 2549 2550 2551Similar you can build U-Boot images from a 'ramdisk.image.gz' file 2552when your kernel is intended to use an initial ramdisk: 2553 2554 -> tools/mkimage -n 'Simple Ramdisk Image' \ 2555 > -A ppc -O linux -T ramdisk -C gzip \ 2556 > -d /LinuxPPC/images/SIMPLE-ramdisk.image.gz examples/simple-initrd 2557 Image Name: Simple Ramdisk Image 2558 Created: Wed Jan 12 14:01:50 2000 2559 Image Type: PowerPC Linux RAMDisk Image (gzip compressed) 2560 Data Size: 566530 Bytes = 553.25 kB = 0.54 MB 2561 Load Address: 0x00000000 2562 Entry Point: 0x00000000 2563 2564 2565Installing a Linux Image: 2566------------------------- 2567 2568To downloading a U-Boot image over the serial (console) interface, 2569you must convert the image to S-Record format: 2570 2571 objcopy -I binary -O srec examples/image examples/image.srec 2572 2573The 'objcopy' does not understand the information in the U-Boot 2574image header, so the resulting S-Record file will be relative to 2575address 0x00000000. To load it to a given address, you need to 2576specify the target address as 'offset' parameter with the 'loads' 2577command. 2578 2579Example: install the image to address 0x40100000 (which on the 2580TQM8xxL is in the first Flash bank): 2581 2582 => erase 40100000 401FFFFF 2583 2584 .......... done 2585 Erased 8 sectors 2586 2587 => loads 40100000 2588 ## Ready for S-Record download ... 2589 ~>examples/image.srec 2590 1 2 3 4 5 6 7 8 9 10 11 12 13 ... 2591 ... 2592 15989 15990 15991 15992 2593 [file transfer complete] 2594 [connected] 2595 ## Start Addr = 0x00000000 2596 2597 2598You can check the success of the download using the 'iminfo' command; 2599this includes a checksum verification so you can be sure no data 2600corruption happened: 2601 2602 => imi 40100000 2603 2604 ## Checking Image at 40100000 ... 2605 Image Name: 2.2.13 for initrd on TQM850L 2606 Image Type: PowerPC Linux Kernel Image (gzip compressed) 2607 Data Size: 335725 Bytes = 327 kB = 0 MB 2608 Load Address: 00000000 2609 Entry Point: 0000000c 2610 Verifying Checksum ... OK 2611 2612 2613Boot Linux: 2614----------- 2615 2616The "bootm" command is used to boot an application that is stored in 2617memory (RAM or Flash). In case of a Linux kernel image, the contents 2618of the "bootargs" environment variable is passed to the kernel as 2619parameters. You can check and modify this variable using the 2620"printenv" and "setenv" commands: 2621 2622 2623 => printenv bootargs 2624 bootargs=root=/dev/ram 2625 2626 => setenv bootargs root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2 2627 2628 => printenv bootargs 2629 bootargs=root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2 2630 2631 => bootm 40020000 2632 ## Booting Linux kernel at 40020000 ... 2633 Image Name: 2.2.13 for NFS on TQM850L 2634 Image Type: PowerPC Linux Kernel Image (gzip compressed) 2635 Data Size: 381681 Bytes = 372 kB = 0 MB 2636 Load Address: 00000000 2637 Entry Point: 0000000c 2638 Verifying Checksum ... OK 2639 Uncompressing Kernel Image ... OK 2640 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 2641 Boot arguments: root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2 2642 time_init: decrementer frequency = 187500000/60 2643 Calibrating delay loop... 49.77 BogoMIPS 2644 Memory: 15208k available (700k kernel code, 444k data, 32k init) [c0000000,c1000000] 2645 ... 2646 2647If you want to boot a Linux kernel with initial ram disk, you pass 2648the memory addresses of both the kernel and the initrd image (PPBCOOT 2649format!) to the "bootm" command: 2650 2651 => imi 40100000 40200000 2652 2653 ## Checking Image at 40100000 ... 2654 Image Name: 2.2.13 for initrd on TQM850L 2655 Image Type: PowerPC Linux Kernel Image (gzip compressed) 2656 Data Size: 335725 Bytes = 327 kB = 0 MB 2657 Load Address: 00000000 2658 Entry Point: 0000000c 2659 Verifying Checksum ... OK 2660 2661 ## Checking Image at 40200000 ... 2662 Image Name: Simple Ramdisk Image 2663 Image Type: PowerPC Linux RAMDisk Image (gzip compressed) 2664 Data Size: 566530 Bytes = 553 kB = 0 MB 2665 Load Address: 00000000 2666 Entry Point: 00000000 2667 Verifying Checksum ... OK 2668 2669 => bootm 40100000 40200000 2670 ## Booting Linux kernel at 40100000 ... 2671 Image Name: 2.2.13 for initrd on TQM850L 2672 Image Type: PowerPC Linux Kernel Image (gzip compressed) 2673 Data Size: 335725 Bytes = 327 kB = 0 MB 2674 Load Address: 00000000 2675 Entry Point: 0000000c 2676 Verifying Checksum ... OK 2677 Uncompressing Kernel Image ... OK 2678 ## Loading RAMDisk Image at 40200000 ... 2679 Image Name: Simple Ramdisk Image 2680 Image Type: PowerPC Linux RAMDisk Image (gzip compressed) 2681 Data Size: 566530 Bytes = 553 kB = 0 MB 2682 Load Address: 00000000 2683 Entry Point: 00000000 2684 Verifying Checksum ... OK 2685 Loading Ramdisk ... OK 2686 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 2687 Boot arguments: root=/dev/ram 2688 time_init: decrementer frequency = 187500000/60 2689 Calibrating delay loop... 49.77 BogoMIPS 2690 ... 2691 RAMDISK: Compressed image found at block 0 2692 VFS: Mounted root (ext2 filesystem). 2693 2694 bash# 2695 2696More About U-Boot Image Types: 2697------------------------------ 2698 2699U-Boot supports the following image types: 2700 2701 "Standalone Programs" are directly runnable in the environment 2702 provided by U-Boot; it is expected that (if they behave 2703 well) you can continue to work in U-Boot after return from 2704 the Standalone Program. 2705 "OS Kernel Images" are usually images of some Embedded OS which 2706 will take over control completely. Usually these programs 2707 will install their own set of exception handlers, device 2708 drivers, set up the MMU, etc. - this means, that you cannot 2709 expect to re-enter U-Boot except by resetting the CPU. 2710 "RAMDisk Images" are more or less just data blocks, and their 2711 parameters (address, size) are passed to an OS kernel that is 2712 being started. 2713 "Multi-File Images" contain several images, typically an OS 2714 (Linux) kernel image and one or more data images like 2715 RAMDisks. This construct is useful for instance when you want 2716 to boot over the network using BOOTP etc., where the boot 2717 server provides just a single image file, but you want to get 2718 for instance an OS kernel and a RAMDisk image. 2719 2720 "Multi-File Images" start with a list of image sizes, each 2721 image size (in bytes) specified by an "uint32_t" in network 2722 byte order. This list is terminated by an "(uint32_t)0". 2723 Immediately after the terminating 0 follow the images, one by 2724 one, all aligned on "uint32_t" boundaries (size rounded up to 2725 a multiple of 4 bytes). 2726 2727 "Firmware Images" are binary images containing firmware (like 2728 U-Boot or FPGA images) which usually will be programmed to 2729 flash memory. 2730 2731 "Script files" are command sequences that will be executed by 2732 U-Boot's command interpreter; this feature is especially 2733 useful when you configure U-Boot to use a real shell (hush) 2734 as command interpreter. 2735 2736 2737Standalone HOWTO: 2738================= 2739 2740One of the features of U-Boot is that you can dynamically load and 2741run "standalone" applications, which can use some resources of 2742U-Boot like console I/O functions or interrupt services. 2743 2744Two simple examples are included with the sources: 2745 2746"Hello World" Demo: 2747------------------- 2748 2749'examples/hello_world.c' contains a small "Hello World" Demo 2750application; it is automatically compiled when you build U-Boot. 2751It's configured to run at address 0x00040004, so you can play with it 2752like that: 2753 2754 => loads 2755 ## Ready for S-Record download ... 2756 ~>examples/hello_world.srec 2757 1 2 3 4 5 6 7 8 9 10 11 ... 2758 [file transfer complete] 2759 [connected] 2760 ## Start Addr = 0x00040004 2761 2762 => go 40004 Hello World! This is a test. 2763 ## Starting application at 0x00040004 ... 2764 Hello World 2765 argc = 7 2766 argv[0] = "40004" 2767 argv[1] = "Hello" 2768 argv[2] = "World!" 2769 argv[3] = "This" 2770 argv[4] = "is" 2771 argv[5] = "a" 2772 argv[6] = "test." 2773 argv[7] = "<NULL>" 2774 Hit any key to exit ... 2775 2776 ## Application terminated, rc = 0x0 2777 2778Another example, which demonstrates how to register a CPM interrupt 2779handler with the U-Boot code, can be found in 'examples/timer.c'. 2780Here, a CPM timer is set up to generate an interrupt every second. 2781The interrupt service routine is trivial, just printing a '.' 2782character, but this is just a demo program. The application can be 2783controlled by the following keys: 2784 2785 ? - print current values og the CPM Timer registers 2786 b - enable interrupts and start timer 2787 e - stop timer and disable interrupts 2788 q - quit application 2789 2790 => loads 2791 ## Ready for S-Record download ... 2792 ~>examples/timer.srec 2793 1 2 3 4 5 6 7 8 9 10 11 ... 2794 [file transfer complete] 2795 [connected] 2796 ## Start Addr = 0x00040004 2797 2798 => go 40004 2799 ## Starting application at 0x00040004 ... 2800 TIMERS=0xfff00980 2801 Using timer 1 2802 tgcr @ 0xfff00980, tmr @ 0xfff00990, trr @ 0xfff00994, tcr @ 0xfff00998, tcn @ 0xfff0099c, ter @ 0xfff009b0 2803 2804Hit 'b': 2805 [q, b, e, ?] Set interval 1000000 us 2806 Enabling timer 2807Hit '?': 2808 [q, b, e, ?] ........ 2809 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0xef6, ter=0x0 2810Hit '?': 2811 [q, b, e, ?] . 2812 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x2ad4, ter=0x0 2813Hit '?': 2814 [q, b, e, ?] . 2815 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x1efc, ter=0x0 2816Hit '?': 2817 [q, b, e, ?] . 2818 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x169d, ter=0x0 2819Hit 'e': 2820 [q, b, e, ?] ...Stopping timer 2821Hit 'q': 2822 [q, b, e, ?] ## Application terminated, rc = 0x0 2823 2824 2825Minicom warning: 2826================ 2827 2828Over time, many people have reported problems when trying to use the 2829"minicom" terminal emulation program for serial download. I (wd) 2830consider minicom to be broken, and recommend not to use it. Under 2831Unix, I recommend to use C-Kermit for general purpose use (and 2832especially for kermit binary protocol download ("loadb" command), and 2833use "cu" for S-Record download ("loads" command). 2834 2835Nevertheless, if you absolutely want to use it try adding this 2836configuration to your "File transfer protocols" section: 2837 2838 Name Program Name U/D FullScr IO-Red. Multi 2839 X kermit /usr/bin/kermit -i -l %l -s Y U Y N N 2840 Y kermit /usr/bin/kermit -i -l %l -r N D Y N N 2841 2842 2843NetBSD Notes: 2844============= 2845 2846Starting at version 0.9.2, U-Boot supports NetBSD both as host 2847(build U-Boot) and target system (boots NetBSD/mpc8xx). 2848 2849Building requires a cross environment; it is known to work on 2850NetBSD/i386 with the cross-powerpc-netbsd-1.3 package (you will also 2851need gmake since the Makefiles are not compatible with BSD make). 2852Note that the cross-powerpc package does not install include files; 2853attempting to build U-Boot will fail because <machine/ansi.h> is 2854missing. This file has to be installed and patched manually: 2855 2856 # cd /usr/pkg/cross/powerpc-netbsd/include 2857 # mkdir powerpc 2858 # ln -s powerpc machine 2859 # cp /usr/src/sys/arch/powerpc/include/ansi.h powerpc/ansi.h 2860 # ${EDIT} powerpc/ansi.h ## must remove __va_list, _BSD_VA_LIST 2861 2862Native builds *don't* work due to incompatibilities between native 2863and U-Boot include files. 2864 2865Booting assumes that (the first part of) the image booted is a 2866stage-2 loader which in turn loads and then invokes the kernel 2867proper. Loader sources will eventually appear in the NetBSD source 2868tree (probably in sys/arc/mpc8xx/stand/u-boot_stage2/); in the 2869meantime, send mail to bruno@exet-ag.de and/or wd@denx.de for 2870details. 2871 2872 2873Implementation Internals: 2874========================= 2875 2876The following is not intended to be a complete description of every 2877implementation detail. However, it should help to understand the 2878inner workings of U-Boot and make it easier to port it to custom 2879hardware. 2880 2881 2882Initial Stack, Global Data: 2883--------------------------- 2884 2885The implementation of U-Boot is complicated by the fact that U-Boot 2886starts running out of ROM (flash memory), usually without access to 2887system RAM (because the memory controller is not initialized yet). 2888This means that we don't have writable Data or BSS segments, and BSS 2889is not initialized as zero. To be able to get a C environment working 2890at all, we have to allocate at least a minimal stack. Implementation 2891options for this are defined and restricted by the CPU used: Some CPU 2892models provide on-chip memory (like the IMMR area on MPC8xx and 2893MPC826x processors), on others (parts of) the data cache can be 2894locked as (mis-) used as memory, etc. 2895 2896 Chris Hallinan posted a good summary of these issues to the 2897 u-boot-users mailing list: 2898 2899 Subject: RE: [U-Boot-Users] RE: More On Memory Bank x (nothingness)? 2900 From: "Chris Hallinan" <clh@net1plus.com> 2901 Date: Mon, 10 Feb 2003 16:43:46 -0500 (22:43 MET) 2902 ... 2903 2904 Correct me if I'm wrong, folks, but the way I understand it 2905 is this: Using DCACHE as initial RAM for Stack, etc, does not 2906 require any physical RAM backing up the cache. The cleverness 2907 is that the cache is being used as a temporary supply of 2908 necessary storage before the SDRAM controller is setup. It's 2909 beyond the scope of this list to expain the details, but you 2910 can see how this works by studying the cache architecture and 2911 operation in the architecture and processor-specific manuals. 2912 2913 OCM is On Chip Memory, which I believe the 405GP has 4K. It 2914 is another option for the system designer to use as an 2915 initial stack/ram area prior to SDRAM being available. Either 2916 option should work for you. Using CS 4 should be fine if your 2917 board designers haven't used it for something that would 2918 cause you grief during the initial boot! It is frequently not 2919 used. 2920 2921 CFG_INIT_RAM_ADDR should be somewhere that won't interfere 2922 with your processor/board/system design. The default value 2923 you will find in any recent u-boot distribution in 2924 Walnut405.h should work for you. I'd set it to a value larger 2925 than your SDRAM module. If you have a 64MB SDRAM module, set 2926 it above 400_0000. Just make sure your board has no resources 2927 that are supposed to respond to that address! That code in 2928 start.S has been around a while and should work as is when 2929 you get the config right. 2930 2931 -Chris Hallinan 2932 DS4.COM, Inc. 2933 2934It is essential to remember this, since it has some impact on the C 2935code for the initialization procedures: 2936 2937* Initialized global data (data segment) is read-only. Do not attempt 2938 to write it. 2939 2940* Do not use any unitialized global data (or implicitely initialized 2941 as zero data - BSS segment) at all - this is undefined, initiali- 2942 zation is performed later (when relocating to RAM). 2943 2944* Stack space is very limited. Avoid big data buffers or things like 2945 that. 2946 2947Having only the stack as writable memory limits means we cannot use 2948normal global data to share information beween the code. But it 2949turned out that the implementation of U-Boot can be greatly 2950simplified by making a global data structure (gd_t) available to all 2951functions. We could pass a pointer to this data as argument to _all_ 2952functions, but this would bloat the code. Instead we use a feature of 2953the GCC compiler (Global Register Variables) to share the data: we 2954place a pointer (gd) to the global data into a register which we 2955reserve for this purpose. 2956 2957When choosing a register for such a purpose we are restricted by the 2958relevant (E)ABI specifications for the current architecture, and by 2959GCC's implementation. 2960 2961For PowerPC, the following registers have specific use: 2962 R1: stack pointer 2963 R2: TOC pointer 2964 R3-R4: parameter passing and return values 2965 R5-R10: parameter passing 2966 R13: small data area pointer 2967 R30: GOT pointer 2968 R31: frame pointer 2969 2970 (U-Boot also uses R14 as internal GOT pointer.) 2971 2972 ==> U-Boot will use R29 to hold a pointer to the global data 2973 2974 Note: on PPC, we could use a static initializer (since the 2975 address of the global data structure is known at compile time), 2976 but it turned out that reserving a register results in somewhat 2977 smaller code - although the code savings are not that big (on 2978 average for all boards 752 bytes for the whole U-Boot image, 2979 624 text + 127 data). 2980 2981On ARM, the following registers are used: 2982 2983 R0: function argument word/integer result 2984 R1-R3: function argument word 2985 R9: GOT pointer 2986 R10: stack limit (used only if stack checking if enabled) 2987 R11: argument (frame) pointer 2988 R12: temporary workspace 2989 R13: stack pointer 2990 R14: link register 2991 R15: program counter 2992 2993 ==> U-Boot will use R8 to hold a pointer to the global data 2994 2995 2996Memory Management: 2997------------------ 2998 2999U-Boot runs in system state and uses physical addresses, i.e. the 3000MMU is not used either for address mapping nor for memory protection. 3001 3002The available memory is mapped to fixed addresses using the memory 3003controller. In this process, a contiguous block is formed for each 3004memory type (Flash, SDRAM, SRAM), even when it consists of several 3005physical memory banks. 3006 3007U-Boot is installed in the first 128 kB of the first Flash bank (on 3008TQM8xxL modules this is the range 0x40000000 ... 0x4001FFFF). After 3009booting and sizing and initializing DRAM, the code relocates itself 3010to the upper end of DRAM. Immediately below the U-Boot code some 3011memory is reserved for use by malloc() [see CFG_MALLOC_LEN 3012configuration setting]. Below that, a structure with global Board 3013Info data is placed, followed by the stack (growing downward). 3014 3015Additionally, some exception handler code is copied to the low 8 kB 3016of DRAM (0x00000000 ... 0x00001FFF). 3017 3018So a typical memory configuration with 16 MB of DRAM could look like 3019this: 3020 3021 0x0000 0000 Exception Vector code 3022 : 3023 0x0000 1FFF 3024 0x0000 2000 Free for Application Use 3025 : 3026 : 3027 3028 : 3029 : 3030 0x00FB FF20 Monitor Stack (Growing downward) 3031 0x00FB FFAC Board Info Data and permanent copy of global data 3032 0x00FC 0000 Malloc Arena 3033 : 3034 0x00FD FFFF 3035 0x00FE 0000 RAM Copy of Monitor Code 3036 ... eventually: LCD or video framebuffer 3037 ... eventually: pRAM (Protected RAM - unchanged by reset) 3038 0x00FF FFFF [End of RAM] 3039 3040 3041System Initialization: 3042---------------------- 3043 3044In the reset configuration, U-Boot starts at the reset entry point 3045(on most PowerPC systens at address 0x00000100). Because of the reset 3046configuration for CS0# this is a mirror of the onboard Flash memory. 3047To be able to re-map memory U-Boot then jumps to its link address. 3048To be able to implement the initialization code in C, a (small!) 3049initial stack is set up in the internal Dual Ported RAM (in case CPUs 3050which provide such a feature like MPC8xx or MPC8260), or in a locked 3051part of the data cache. After that, U-Boot initializes the CPU core, 3052the caches and the SIU. 3053 3054Next, all (potentially) available memory banks are mapped using a 3055preliminary mapping. For example, we put them on 512 MB boundaries 3056(multiples of 0x20000000: SDRAM on 0x00000000 and 0x20000000, Flash 3057on 0x40000000 and 0x60000000, SRAM on 0x80000000). Then UPM A is 3058programmed for SDRAM access. Using the temporary configuration, a 3059simple memory test is run that determines the size of the SDRAM 3060banks. 3061 3062When there is more than one SDRAM bank, and the banks are of 3063different size, the largest is mapped first. For equal size, the first 3064bank (CS2#) is mapped first. The first mapping is always for address 30650x00000000, with any additional banks following immediately to create 3066contiguous memory starting from 0. 3067 3068Then, the monitor installs itself at the upper end of the SDRAM area 3069and allocates memory for use by malloc() and for the global Board 3070Info data; also, the exception vector code is copied to the low RAM 3071pages, and the final stack is set up. 3072 3073Only after this relocation will you have a "normal" C environment; 3074until that you are restricted in several ways, mostly because you are 3075running from ROM, and because the code will have to be relocated to a 3076new address in RAM. 3077 3078 3079U-Boot Porting Guide: 3080---------------------- 3081 3082[Based on messages by Jerry Van Baren in the U-Boot-Users mailing 3083list, October 2002] 3084 3085 3086int main (int argc, char *argv[]) 3087{ 3088 sighandler_t no_more_time; 3089 3090 signal (SIGALRM, no_more_time); 3091 alarm (PROJECT_DEADLINE - toSec (3 * WEEK)); 3092 3093 if (available_money > available_manpower) { 3094 pay consultant to port U-Boot; 3095 return 0; 3096 } 3097 3098 Download latest U-Boot source; 3099 3100 Subscribe to u-boot-users mailing list; 3101 3102 if (clueless) { 3103 email ("Hi, I am new to U-Boot, how do I get started?"); 3104 } 3105 3106 while (learning) { 3107 Read the README file in the top level directory; 3108 Read http://www.denx.de/re/DPLG.html 3109 Read the source, Luke; 3110 } 3111 3112 if (available_money > toLocalCurrency ($2500)) { 3113 Buy a BDI2000; 3114 } else { 3115 Add a lot of aggravation and time; 3116 } 3117 3118 Create your own board support subdirectory; 3119 3120 Create your own board config file; 3121 3122 while (!running) { 3123 do { 3124 Add / modify source code; 3125 } until (compiles); 3126 Debug; 3127 if (clueless) 3128 email ("Hi, I am having problems..."); 3129 } 3130 Send patch file to Wolfgang; 3131 3132 return 0; 3133} 3134 3135void no_more_time (int sig) 3136{ 3137 hire_a_guru(); 3138} 3139 3140 3141Coding Standards: 3142----------------- 3143 3144All contributions to U-Boot should conform to the Linux kernel 3145coding style; see the file "Documentation/CodingStyle" in your Linux 3146kernel source directory. 3147 3148Please note that U-Boot is implemented in C (and to some small parts 3149in Assembler); no C++ is used, so please do not use C++ style 3150comments (//) in your code. 3151 3152Submissions which do not conform to the standards may be returned 3153with a request to reformat the changes. 3154 3155 3156Submitting Patches: 3157------------------- 3158 3159Since the number of patches for U-Boot is growing, we need to 3160establish some rules. Submissions which do not conform to these rules 3161may be rejected, even when they contain important and valuable stuff. 3162 3163 3164When you send a patch, please include the following information with 3165it: 3166 3167* For bug fixes: a description of the bug and how your patch fixes 3168 this bug. Please try to include a way of demonstrating that the 3169 patch actually fixes something. 3170 3171* For new features: a description of the feature and your 3172 implementation. 3173 3174* A CHANGELOG entry as plaintext (separate from the patch) 3175 3176* For major contributions, your entry to the CREDITS file 3177 3178* When you add support for a new board, don't forget to add this 3179 board to the MAKEALL script, too. 3180 3181* If your patch adds new configuration options, don't forget to 3182 document these in the README file. 3183 3184* The patch itself. If you are accessing the CVS repository use "cvs 3185 update; cvs diff -puRN"; else, use "diff -purN OLD NEW". If your 3186 version of diff does not support these options, then get the latest 3187 version of GNU diff. 3188 3189 The current directory when running this command shall be the top 3190 level directory of the U-Boot source tree, or it's parent directory 3191 (i. e. please make sure that your patch includes sufficient 3192 directory information for the affected files). 3193 3194 We accept patches as plain text, MIME attachments or as uuencoded 3195 gzipped text. 3196 3197* If one logical set of modifications affects or creates several 3198 files, all these changes shall be submitted in a SINGLE patch file. 3199 3200* Changesets that contain different, unrelated modifications shall be 3201 submitted as SEPARATE patches, one patch per changeset. 3202 3203 3204Notes: 3205 3206* Before sending the patch, run the MAKEALL script on your patched 3207 source tree and make sure that no errors or warnings are reported 3208 for any of the boards. 3209 3210* Keep your modifications to the necessary minimum: A patch 3211 containing several unrelated changes or arbitrary reformats will be 3212 returned with a request to re-formatting / split it. 3213 3214* If you modify existing code, make sure that your new code does not 3215 add to the memory footprint of the code ;-) Small is beautiful! 3216 When adding new features, these should compile conditionally only 3217 (using #ifdef), and the resulting code with the new feature 3218 disabled must not need more memory than the old code without your 3219 modification. 3220