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 dependend files 123- common Misc architecture independend functions 124- cpu CPU specific files 125- disk Code for disk drive partition handling 126- doc Documentation (don't expect too much) 127- drivers Common 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/mpc5xx Files specific to Motorola MPC5xx CPUs 144- cpu/mpc8xx Files specific to Motorola MPC8xx CPUs 145- cpu/mpc824x Files specific to Motorola MPC824x CPUs 146- cpu/mpc8260 Files specific to Motorola MPC8260 CPU 147- cpu/ppc4xx Files specific to IBM 4xx CPUs 148 149- board/LEOX/ Files specific to boards manufactured by The LEOX team 150- board/LEOX/elpt860 Files specific to ELPT860 boards 151- board/RPXClassic 152 Files specific to RPXClassic boards 153- board/RPXlite Files specific to RPXlite boards 154- board/c2mon Files specific to c2mon boards 155- board/cmi Files specific to cmi boards 156- board/cogent Files specific to Cogent boards 157 (need further configuration) 158 Files specific to CPCIISER4 boards 159- board/cpu86 Files specific to CPU86 boards 160- board/cray/ Files specific to boards manufactured by Cray 161- board/cray/L1 Files specific to L1 boards 162- board/cu824 Files specific to CU824 boards 163- board/ebony Files specific to IBM Ebony board 164- board/eric Files specific to ERIC boards 165- board/esd/ Files specific to boards manufactured by ESD 166- board/esd/adciop Files specific to ADCIOP boards 167- board/esd/ar405 Files specific to AR405 boards 168- board/esd/canbt Files specific to CANBT boards 169- board/esd/cpci405 Files specific to CPCI405 boards 170- board/esd/cpciiser4 Files specific to CPCIISER4 boards 171- board/esd/common Common files for ESD boards 172- board/esd/dasa_sim Files specific to DASA_SIM boards 173- board/esd/du405 Files specific to DU405 boards 174- board/esd/ocrtc Files specific to OCRTC boards 175- board/esd/pci405 Files specific to PCI405 boards 176- board/esteem192e 177 Files specific to ESTEEM192E boards 178- board/etx094 Files specific to ETX_094 boards 179- board/evb64260 180 Files specific to EVB64260 boards 181- board/fads Files specific to FADS boards 182- board/flagadm Files specific to FLAGADM boards 183- board/gen860t Files specific to GEN860T boards 184- board/genietv Files specific to GENIETV boards 185- board/gth Files specific to GTH boards 186- board/hermes Files specific to HERMES boards 187- board/hymod Files specific to HYMOD boards 188- board/icu862 Files specific to ICU862 boards 189- board/ip860 Files specific to IP860 boards 190- board/iphase4539 191 Files specific to Interphase4539 boards 192- board/ivm Files specific to IVMS8/IVML24 boards 193- board/lantec Files specific to LANTEC boards 194- board/lwmon Files specific to LWMON boards 195- board/mbx8xx Files specific to MBX boards 196- board/mpc8260ads 197 Files specific to MMPC8260ADS boards 198- board/mpl/ Files specific to boards manufactured by MPL 199- board/mpl/common Common files for MPL boards 200- board/mpl/pip405 Files specific to PIP405 boards 201- board/mpl/mip405 Files specific to MIP405 boards 202- board/musenki Files specific to MUSEKNI boards 203- board/mvs1 Files specific to MVS1 boards 204- board/nx823 Files specific to NX823 boards 205- board/oxc Files specific to OXC boards 206- board/pcippc2 Files specific to PCIPPC2/PCIPPC6 boards 207- board/pm826 Files specific to PM826 boards 208- board/ppmc8260 209 Files specific to PPMC8260 boards 210- board/rpxsuper 211 Files specific to RPXsuper boards 212- board/rsdproto 213 Files specific to RSDproto boards 214- board/sandpoint 215 Files specific to Sandpoint boards 216- board/sbc8260 Files specific to SBC8260 boards 217- board/sacsng Files specific to SACSng boards 218- board/siemens Files specific to boards manufactured by Siemens AG 219- board/siemens/CCM Files specific to CCM boards 220- board/siemens/IAD210 Files specific to IAD210 boards 221- board/siemens/SCM Files specific to SCM boards 222- board/siemens/pcu_e Files specific to PCU_E boards 223- board/sixnet Files specific to SIXNET boards 224- board/spd8xx Files specific to SPD8xxTS boards 225- board/tqm8260 Files specific to TQM8260 boards 226- board/tqm8xx Files specific to TQM8xxL boards 227- board/w7o Files specific to W7O boards 228- board/walnut405 229 Files specific to Walnut405 boards 230- board/westel/ Files specific to boards manufactured by Westel Wireless 231- board/westel/amx860 Files specific to AMX860 boards 232- board/utx8245 Files specific to UTX8245 boards 233 234Software Configuration: 235======================= 236 237Configuration is usually done using C preprocessor defines; the 238rationale behind that is to avoid dead code whenever possible. 239 240There are two classes of configuration variables: 241 242* Configuration _OPTIONS_: 243 These are selectable by the user and have names beginning with 244 "CONFIG_". 245 246* Configuration _SETTINGS_: 247 These depend on the hardware etc. and should not be meddled with if 248 you don't know what you're doing; they have names beginning with 249 "CFG_". 250 251Later we will add a configuration tool - probably similar to or even 252identical to what's used for the Linux kernel. Right now, we have to 253do the configuration by hand, which means creating some symbolic 254links and editing some configuration files. We use the TQM8xxL boards 255as an example here. 256 257 258Selection of Processor Architecture and Board Type: 259--------------------------------------------------- 260 261For all supported boards there are ready-to-use default 262configurations available; just type "make <board_name>_config". 263 264Example: For a TQM823L module type: 265 266 cd u-boot 267 make TQM823L_config 268 269For the Cogent platform, you need to specify the cpu type as well; 270e.g. "make cogent_mpc8xx_config". And also configure the cogent 271directory according to the instructions in cogent/README. 272 273 274Configuration Options: 275---------------------- 276 277Configuration depends on the combination of board and CPU type; all 278such information is kept in a configuration file 279"include/configs/<board_name>.h". 280 281Example: For a TQM823L module, all configuration settings are in 282"include/configs/TQM823L.h". 283 284 285Many of the options are named exactly as the corresponding Linux 286kernel configuration options. The intention is to make it easier to 287build a config tool - later. 288 289 290The following options need to be configured: 291 292- CPU Type: Define exactly one of 293 294 PowerPC based CPUs: 295 ------------------- 296 CONFIG_MPC823, CONFIG_MPC850, CONFIG_MPC855, CONFIG_MPC860 297 or CONFIG_MPC5xx 298 or CONFIG_MPC824X, CONFIG_MPC8260 299 or CONFIG_IOP480 300 or CONFIG_405GP 301 or CONFIG_440 302 or CONFIG_MPC74xx 303 304 ARM based CPUs: 305 --------------- 306 CONFIG_SA1110 307 CONFIG_ARM7 308 CONFIG_PXA250 309 310 311- Board Type: Define exactly one of 312 313 PowerPC based boards: 314 --------------------- 315 316 CONFIG_ADCIOP, CONFIG_ICU862 CONFIG_RPXsuper, 317 CONFIG_ADS860, CONFIG_IP860, CONFIG_SM850, 318 CONFIG_AMX860, CONFIG_IPHASE4539, CONFIG_SPD823TS, 319 CONFIG_AR405, CONFIG_IVML24, CONFIG_SXNI855T, 320 CONFIG_BAB7xx, CONFIG_IVML24_128, CONFIG_Sandpoint8240, 321 CONFIG_CANBT, CONFIG_IVML24_256, CONFIG_Sandpoint8245, 322 CONFIG_CCM, CONFIG_IVMS8, CONFIG_TQM823L, 323 CONFIG_CPCI405, CONFIG_IVMS8_128, CONFIG_TQM850L, 324 CONFIG_CPCI4052, CONFIG_IVMS8_256, CONFIG_TQM855L, 325 CONFIG_CPCIISER4, CONFIG_LANTEC, CONFIG_TQM860L, 326 CONFIG_CPU86, CONFIG_MBX, CONFIG_TQM8260, 327 CONFIG_CRAYL1, CONFIG_MBX860T, CONFIG_TTTech, 328 CONFIG_CU824, CONFIG_MHPC, CONFIG_UTX8245, 329 CONFIG_DASA_SIM, CONFIG_MIP405, CONFIG_W7OLMC, 330 CONFIG_DU405, CONFIG_MOUSSE, CONFIG_W7OLMG, 331 CONFIG_ELPPC, CONFIG_MPC8260ADS, CONFIG_WALNUT405, 332 CONFIG_ERIC, CONFIG_MUSENKI, CONFIG_ZUMA, 333 CONFIG_ESTEEM192E, CONFIG_MVS1, CONFIG_c2mon, 334 CONFIG_ETX094, CONFIG_NX823, CONFIG_cogent_mpc8260, 335 CONFIG_EVB64260, CONFIG_OCRTC, CONFIG_cogent_mpc8xx, 336 CONFIG_FADS823, CONFIG_ORSG, CONFIG_ep8260, 337 CONFIG_FADS850SAR, CONFIG_OXC, CONFIG_gw8260, 338 CONFIG_FADS860T, CONFIG_PCI405, CONFIG_hermes, 339 CONFIG_FLAGADM, CONFIG_PCIPPC2, CONFIG_hymod, 340 CONFIG_FPS850L, CONFIG_PCIPPC6, CONFIG_lwmon, 341 CONFIG_GEN860T, CONFIG_PIP405, CONFIG_pcu_e, 342 CONFIG_GENIETV, CONFIG_PM826, CONFIG_ppmc8260, 343 CONFIG_GTH, CONFIG_RPXClassic, CONFIG_rsdproto, 344 CONFIG_IAD210, CONFIG_RPXlite, CONFIG_sbc8260, 345 CONFIG_EBONY, CONFIG_sacsng, CONFIG_FPS860L, 346 CONFIG_V37, CONFIG_ELPT860, CONFIG_CMI 347 348 ARM based boards: 349 ----------------- 350 351 CONFIG_HHP_CRADLE, CONFIG_DNP1110, CONFIG_EP7312, 352 CONFIG_IMPA7, CONFIG_LART, CONFIG_LUBBOCK, 353 CONFIG_SHANNON, CONFIG_SMDK2400, CONFIG_SMDK2410, 354 CONFIG_TRAB 355 356 357- CPU Module Type: (if CONFIG_COGENT is defined) 358 Define exactly one of 359 CONFIG_CMA286_60_OLD 360--- FIXME --- not tested yet: 361 CONFIG_CMA286_60, CONFIG_CMA286_21, CONFIG_CMA286_60P, 362 CONFIG_CMA287_23, CONFIG_CMA287_50 363 364- Motherboard Type: (if CONFIG_COGENT is defined) 365 Define exactly one of 366 CONFIG_CMA101, CONFIG_CMA102 367 368- Motherboard I/O Modules: (if CONFIG_COGENT is defined) 369 Define one or more of 370 CONFIG_CMA302 371 372- Motherboard Options: (if CONFIG_CMA101 or CONFIG_CMA102 are defined) 373 Define one or more of 374 CONFIG_LCD_HEARTBEAT - update a character position on 375 the lcd display every second with 376 a "rotator" |\-/|\-/ 377 378- MPC824X Family Member (if CONFIG_MPC824X is defined) 379 Define exactly one of 380 CONFIG_MPC8240, CONFIG_MPC8245 381 382- 8xx CPU Options: (if using an 8xx cpu) 383 Define one or more of 384 CONFIG_8xx_GCLK_FREQ - if get_gclk_freq() can not work e.g. 385 no 32KHz reference PIT/RTC clock 386 387- Clock Interface: 388 CONFIG_CLOCKS_IN_MHZ 389 390 U-Boot stores all clock information in Hz 391 internally. For binary compatibility with older Linux 392 kernels (which expect the clocks passed in the 393 bd_info data to be in MHz) the environment variable 394 "clocks_in_mhz" can be defined so that U-Boot 395 converts clock data to MHZ before passing it to the 396 Linux kernel. 397 398 When CONFIG_CLOCKS_IN_MHZ is defined, a definition of 399 "clocks_in_mhz=1" is automatically included in the 400 default environment. 401 402- Console Interface: 403 Depending on board, define exactly one serial port 404 (like CONFIG_8xx_CONS_SMC1, CONFIG_8xx_CONS_SMC2, 405 CONFIG_8xx_CONS_SCC1, ...), or switch off the serial 406 console by defining CONFIG_8xx_CONS_NONE 407 408 Note: if CONFIG_8xx_CONS_NONE is defined, the serial 409 port routines must be defined elsewhere 410 (i.e. serial_init(), serial_getc(), ...) 411 412 CONFIG_CFB_CONSOLE 413 Enables console device for a color framebuffer. Needs following 414 defines (cf. smiLynxEM, i8042, board/eltec/bab7xx) 415 VIDEO_FB_LITTLE_ENDIAN graphic memory organisation 416 (default big endian) 417 VIDEO_HW_RECTFILL graphic chip supports 418 rectangle fill 419 (cf. smiLynxEM) 420 VIDEO_HW_BITBLT graphic chip supports 421 bit-blit (cf. smiLynxEM) 422 VIDEO_VISIBLE_COLS visible pixel columns 423 (cols=pitch) 424 VIDEO_VISIBLE_ROWS visible pixel rows 425 VIDEO_PIXEL_SIZE bytes per pixel 426 VIDEO_DATA_FORMAT graphic data format 427 (0-5, cf. cfb_console.c) 428 VIDEO_FB_ADRS framebuffer address 429 VIDEO_KBD_INIT_FCT keyboard int fct 430 (i.e. i8042_kbd_init()) 431 VIDEO_TSTC_FCT test char fct 432 (i.e. i8042_tstc) 433 VIDEO_GETC_FCT get char fct 434 (i.e. i8042_getc) 435 CONFIG_CONSOLE_CURSOR cursor drawing on/off 436 (requires blink timer 437 cf. i8042.c) 438 CFG_CONSOLE_BLINK_COUNT blink interval (cf. i8042.c) 439 CONFIG_CONSOLE_TIME display time/date info in 440 upper right corner 441 (requires CFG_CMD_DATE) 442 CONFIG_VIDEO_LOGO display Linux logo in 443 upper left corner 444 CONFIG_VIDEO_BMP_LOGO use bmp_logo.h instead of 445 linux_logo.h for logo. 446 Requires CONFIG_VIDEO_LOGO 447 CONFIG_CONSOLE_EXTRA_INFO 448 addional board info beside 449 the logo 450 451 When CONFIG_CFB_CONSOLE is defined, video console is 452 default i/o. Serial console can be forced with 453 environment 'console=serial'. 454 455- Console Baudrate: 456 CONFIG_BAUDRATE - in bps 457 Select one of the baudrates listed in 458 CFG_BAUDRATE_TABLE, see below. 459 460- Interrupt driven serial port input: 461 CONFIG_SERIAL_SOFTWARE_FIFO 462 463 PPC405GP only. 464 Use an interrupt handler for receiving data on the 465 serial port. It also enables using hardware handshake 466 (RTS/CTS) and UART's built-in FIFO. Set the number of 467 bytes the interrupt driven input buffer should have. 468 469 Set to 0 to disable this feature (this is the default). 470 This will also disable hardware handshake. 471 472- Boot Delay: CONFIG_BOOTDELAY - in seconds 473 Delay before automatically booting the default image; 474 set to -1 to disable autoboot. 475 476 See doc/README.autoboot for these options that 477 work with CONFIG_BOOTDELAY. None are required. 478 CONFIG_BOOT_RETRY_TIME 479 CONFIG_BOOT_RETRY_MIN 480 CONFIG_AUTOBOOT_KEYED 481 CONFIG_AUTOBOOT_PROMPT 482 CONFIG_AUTOBOOT_DELAY_STR 483 CONFIG_AUTOBOOT_STOP_STR 484 CONFIG_AUTOBOOT_DELAY_STR2 485 CONFIG_AUTOBOOT_STOP_STR2 486 CONFIG_ZERO_BOOTDELAY_CHECK 487 CONFIG_RESET_TO_RETRY 488 489- Autoboot Command: 490 CONFIG_BOOTCOMMAND 491 Only needed when CONFIG_BOOTDELAY is enabled; 492 define a command string that is automatically executed 493 when no character is read on the console interface 494 within "Boot Delay" after reset. 495 496 CONFIG_BOOTARGS 497 This can be used to pass arguments to the bootm 498 command. The value of CONFIG_BOOTARGS goes into the 499 environment value "bootargs". 500 501 CONFIG_RAMBOOT and CONFIG_NFSBOOT 502 The value of these goes into the environment as 503 "ramboot" and "nfsboot" respectively, and can be used 504 as a convenience, when switching between booting from 505 ram and nfs. 506 507- Pre-Boot Commands: 508 CONFIG_PREBOOT 509 510 When this option is #defined, the existence of the 511 environment variable "preboot" will be checked 512 immediately before starting the CONFIG_BOOTDELAY 513 countdown and/or running the auto-boot command resp. 514 entering interactive mode. 515 516 This feature is especially useful when "preboot" is 517 automatically generated or modified. For an example 518 see the LWMON board specific code: here "preboot" is 519 modified when the user holds down a certain 520 combination of keys on the (special) keyboard when 521 booting the systems 522 523- Serial Download Echo Mode: 524 CONFIG_LOADS_ECHO 525 If defined to 1, all characters received during a 526 serial download (using the "loads" command) are 527 echoed back. This might be needed by some terminal 528 emulations (like "cu"), but may as well just take 529 time on others. This setting #define's the initial 530 value of the "loads_echo" environment variable. 531 532- Kgdb Serial Baudrate: (if CFG_CMD_KGDB is defined) 533 CONFIG_KGDB_BAUDRATE 534 Select one of the baudrates listed in 535 CFG_BAUDRATE_TABLE, see below. 536 537- Monitor Functions: 538 CONFIG_COMMANDS 539 Most monitor functions can be selected (or 540 de-selected) by adjusting the definition of 541 CONFIG_COMMANDS; to select individual functions, 542 #define CONFIG_COMMANDS by "OR"ing any of the 543 following values: 544 545 #define enables commands: 546 ------------------------- 547 CFG_CMD_ASKENV * ask for env variable 548 CFG_CMD_BDI bdinfo 549 CFG_CMD_BEDBUG Include BedBug Debugger 550 CFG_CMD_BOOTD bootd 551 CFG_CMD_CACHE icache, dcache 552 CFG_CMD_CONSOLE coninfo 553 CFG_CMD_DATE * support for RTC, date/time... 554 CFG_CMD_DHCP DHCP support 555 CFG_CMD_ECHO * echo arguments 556 CFG_CMD_EEPROM * EEPROM read/write support 557 CFG_CMD_ELF bootelf, bootvx 558 CFG_CMD_ENV saveenv 559 CFG_CMD_FDC * Floppy Disk Support 560 CFG_CMD_FDOS * Dos diskette Support 561 CFG_CMD_FLASH flinfo, erase, protect 562 CFG_CMD_FPGA FPGA device initialization support 563 CFG_CMD_I2C * I2C serial bus support 564 CFG_CMD_IDE * IDE harddisk support 565 CFG_CMD_IMI iminfo 566 CFG_CMD_IMMAP * IMMR dump support 567 CFG_CMD_IRQ * irqinfo 568 CFG_CMD_KGDB * kgdb 569 CFG_CMD_LOADB loadb 570 CFG_CMD_LOADS loads 571 CFG_CMD_MEMORY md, mm, nm, mw, cp, cmp, crc, base, 572 loop, mtest 573 CFG_CMD_MII MII utility commands 574 CFG_CMD_NET bootp, tftpboot, rarpboot 575 CFG_CMD_PCI * pciinfo 576 CFG_CMD_PCMCIA * PCMCIA support 577 CFG_CMD_REGINFO * Register dump 578 CFG_CMD_RUN run command in env variable 579 CFG_CMD_SCSI * SCSI Support 580 CFG_CMD_SETGETDCR Support for DCR Register access (4xx only) 581 CFG_CMD_SPI * SPI serial bus support 582 CFG_CMD_USB * USB support 583 CFG_CMD_BSP * Board SPecific functions 584 ----------------------------------------------- 585 CFG_CMD_ALL all 586 587 CFG_CMD_DFL Default configuration; at the moment 588 this is includes all commands, except 589 the ones marked with "*" in the list 590 above. 591 592 If you don't define CONFIG_COMMANDS it defaults to 593 CFG_CMD_DFL in include/cmd_confdefs.h. A board can 594 override the default settings in the respective 595 include file. 596 597 EXAMPLE: If you want all functions except of network 598 support you can write: 599 600 #define CONFIG_COMMANDS (CFG_CMD_ALL & ~CFG_CMD_NET) 601 602 603 Note: Don't enable the "icache" and "dcache" commands 604 (configuration option CFG_CMD_CACHE) unless you know 605 what you (and your U-Boot users) are doing. Data 606 cache cannot be enabled on systems like the 8xx or 607 8260 (where accesses to the IMMR region must be 608 uncached), and it cannot be disabled on all other 609 systems where we (mis-) use the data cache to hold an 610 initial stack and some data. 611 612 613 XXX - this list needs to get updated! 614 615- Watchdog: 616 CONFIG_WATCHDOG 617 If this variable is defined, it enables watchdog 618 support. There must support in the platform specific 619 code for a watchdog. For the 8xx and 8260 CPUs, the 620 SIU Watchdog feature is enabled in the SYPCR 621 register. 622 623- U-Boot Version: 624 CONFIG_VERSION_VARIABLE 625 If this variable is defined, an environment variable 626 named "ver" is created by U-Boot showing the U-Boot 627 version as printed by the "version" command. 628 This variable is readonly. 629 630- Real-Time Clock: 631 632 When CFG_CMD_DATE is selected, the type of the RTC 633 has to be selected, too. Define exactly one of the 634 following options: 635 636 CONFIG_RTC_MPC8xx - use internal RTC of MPC8xx 637 CONFIG_RTC_PCF8563 - use Philips PCF8563 RTC 638 CONFIG_RTC_MC146818 - use MC146818 RTC 639 CONFIG_RTC_DS1307 - use Maxim, Inc. DS1307 RTC 640 CONFIG_RTC_DS1337 - use Maxim, Inc. DS1337 RTC 641 CONFIG_RTC_DS164x - use Dallas DS164x RTC 642 643- Timestamp Support: 644 645 When CONFIG_TIMESTAMP is selected, the timestamp 646 (date and time) of an image is printed by image 647 commands like bootm or iminfo. This option is 648 automatically enabled when you select CFG_CMD_DATE . 649 650- Partition Support: 651 CONFIG_MAC_PARTITION and/or CONFIG_DOS_PARTITION 652 and/or CONFIG_ISO_PARTITION 653 654 If IDE or SCSI support is enabled (CFG_CMD_IDE or 655 CFG_CMD_SCSI) you must configure support for at least 656 one partition type as well. 657 658- IDE Reset method: 659 CONFIG_IDE_RESET_ROUTINE 660 661 Set this to define that instead of a reset Pin, the 662 routine ide_set_reset(int idereset) will be used. 663 664- ATAPI Support: 665 CONFIG_ATAPI 666 667 Set this to enable ATAPI support. 668 669- SCSI Support: 670 At the moment only there is only support for the 671 SYM53C8XX SCSI controller; define 672 CONFIG_SCSI_SYM53C8XX to enable it. 673 674 CFG_SCSI_MAX_LUN [8], CFG_SCSI_MAX_SCSI_ID [7] and 675 CFG_SCSI_MAX_DEVICE [CFG_SCSI_MAX_SCSI_ID * 676 CFG_SCSI_MAX_LUN] can be adjusted to define the 677 maximum numbers of LUNs, SCSI ID's and target 678 devices. 679 CFG_SCSI_SYM53C8XX_CCF to fix clock timing (80Mhz) 680 681- NETWORK Support (PCI): 682 CONFIG_EEPRO100 683 Support for Intel 82557/82559/82559ER chips. 684 Optional CONFIG_EEPRO100_SROM_WRITE enables eeprom 685 write routine for first time initialisation. 686 687 CONFIG_TULIP 688 Support for Digital 2114x chips. 689 Optional CONFIG_TULIP_SELECT_MEDIA for board specific 690 modem chip initialisation (KS8761/QS6611). 691 692 CONFIG_NATSEMI 693 Support for National dp83815 chips. 694 695 CONFIG_NS8382X 696 Support for National dp8382[01] gigabit chips. 697 698- USB Support: 699 At the moment only the UHCI host controller is 700 supported (PIP405, MIP405); define 701 CONFIG_USB_UHCI to enable it. 702 define CONFIG_USB_KEYBOARD to enable the USB Keyboard 703 end define CONFIG_USB_STORAGE to enable the USB 704 storage devices. 705 Note: 706 Supported are USB Keyboards and USB Floppy drives 707 (TEAC FD-05PUB). 708 709- Keyboard Support: 710 CONFIG_ISA_KEYBOARD 711 712 Define this to enable standard (PC-Style) keyboard 713 support 714 715 CONFIG_I8042_KBD 716 Standard PC keyboard driver with US (is default) and 717 GERMAN key layout (switch via environment 'keymap=de') support. 718 Export function i8042_kbd_init, i8042_tstc and i8042_getc 719 for cfb_console. Supports cursor blinking. 720 721- Video support: 722 CONFIG_VIDEO 723 724 Define this to enable video support (for output to 725 video). 726 727 CONFIG_VIDEO_CT69000 728 729 Enable Chips & Technologies 69000 Video chip 730 731 CONFIG_VIDEO_SMI_LYNXEM 732 Enable Silicon Motion SMI 712/710/810 Video chip 733 Videomode are selected via environment 'videomode' with 734 standard LiLo mode numbers. 735 Following modes are supported (* is default): 736 737 800x600 1024x768 1280x1024 738 256 (8bit) 303* 305 307 739 65536 (16bit) 314 317 31a 740 16,7 Mill (24bit) 315 318 31b 741 (i.e. setenv videomode 317; saveenv; reset;) 742 743 CONFIG_VIDEO_SED13806 744 Enable Epson SED13806 driver. This driver supports 8bpp 745 and 16bpp modes defined by CONFIG_VIDEO_SED13806_8BPP 746 or CONFIG_VIDEO_SED13806_16BPP 747 748 749- LCD Support: CONFIG_LCD 750 751 Define this to enable LCD support (for output to LCD 752 display); also select one of the supported displays 753 by defining one of these: 754 755 CONFIG_NEC_NL6648AC33: 756 757 NEC NL6648AC33-18. Active, color, single scan. 758 759 CONFIG_NEC_NL6648BC20 760 761 NEC NL6648BC20-08. 6.5", 640x480. 762 Active, color, single scan. 763 764 CONFIG_SHARP_16x9 765 766 Sharp 320x240. Active, color, single scan. 767 It isn't 16x9, and I am not sure what it is. 768 769 CONFIG_SHARP_LQ64D341 770 771 Sharp LQ64D341 display, 640x480. 772 Active, color, single scan. 773 774 CONFIG_HLD1045 775 776 HLD1045 display, 640x480. 777 Active, color, single scan. 778 779 CONFIG_OPTREX_BW 780 781 Optrex CBL50840-2 NF-FW 99 22 M5 782 or 783 Hitachi LMG6912RPFC-00T 784 or 785 Hitachi SP14Q002 786 787 320x240. Black & white. 788 789 Normally display is black on white background; define 790 CFG_WHITE_ON_BLACK to get it inverted. 791 792- Ethernet address: 793 CONFIG_ETHADDR 794 CONFIG_ETH2ADDR 795 CONFIG_ETH3ADDR 796 797 Define a default value for ethernet address to use 798 for the respective ethernet interface, in case this 799 is not determined automatically. 800 801- IP address: 802 CONFIG_IPADDR 803 804 Define a default value for the IP address to use for 805 the default ethernet interface, in case this is not 806 determined through e.g. bootp. 807 808- Server IP address: 809 CONFIG_SERVERIP 810 811 Defines a default value for theIP address of a TFTP 812 server to contact when using the "tftboot" command. 813 814- BOOTP Recovery Mode: 815 CONFIG_BOOTP_RANDOM_DELAY 816 817 If you have many targets in a network that try to 818 boot using BOOTP, you may want to avoid that all 819 systems send out BOOTP requests at precisely the same 820 moment (which would happen for instance at recovery 821 from a power failure, when all systems will try to 822 boot, thus flooding the BOOTP server. Defining 823 CONFIG_BOOTP_RANDOM_DELAY causes a random delay to be 824 inserted before sending out BOOTP requests. The 825 following delays are insterted then: 826 827 1st BOOTP request: delay 0 ... 1 sec 828 2nd BOOTP request: delay 0 ... 2 sec 829 3rd BOOTP request: delay 0 ... 4 sec 830 4th and following 831 BOOTP requests: delay 0 ... 8 sec 832 833- Status LED: CONFIG_STATUS_LED 834 835 Several configurations allow to display the current 836 status using a LED. For instance, the LED will blink 837 fast while running U-Boot code, stop blinking as 838 soon as a reply to a BOOTP request was received, and 839 start blinking slow once the Linux kernel is running 840 (supported by a status LED driver in the Linux 841 kernel). Defining CONFIG_STATUS_LED enables this 842 feature in U-Boot. 843 844- CAN Support: CONFIG_CAN_DRIVER 845 846 Defining CONFIG_CAN_DRIVER enables CAN driver support 847 on those systems that support this (optional) 848 feature, like the TQM8xxL modules. 849 850- I2C Support: CONFIG_HARD_I2C | CONFIG_SOFT_I2C 851 852 Enables I2C serial bus commands. If this is selected, 853 either CONFIG_HARD_I2C or CONFIG_SOFT_I2C must be defined 854 to include the appropriate I2C driver. 855 856 See also: common/cmd_i2c.c for a description of the 857 command line interface. 858 859 860 CONFIG_HARD_I2C 861 862 Selects the CPM hardware driver for I2C. 863 864 CONFIG_SOFT_I2C 865 866 Use software (aka bit-banging) driver instead of CPM 867 or similar hardware support for I2C. This is configured 868 via the following defines. 869 870 I2C_INIT 871 872 (Optional). Any commands necessary to enable I2C 873 controller or configure ports. 874 875 I2C_PORT 876 877 (Only for MPC8260 CPU). The I/O port to use (the code 878 assumes both bits are on the same port). Valid values 879 are 0..3 for ports A..D. 880 881 I2C_ACTIVE 882 883 The code necessary to make the I2C data line active 884 (driven). If the data line is open collector, this 885 define can be null. 886 887 I2C_TRISTATE 888 889 The code necessary to make the I2C data line tri-stated 890 (inactive). If the data line is open collector, this 891 define can be null. 892 893 I2C_READ 894 895 Code that returns TRUE if the I2C data line is high, 896 FALSE if it is low. 897 898 I2C_SDA(bit) 899 900 If <bit> is TRUE, sets the I2C data line high. If it 901 is FALSE, it clears it (low). 902 903 I2C_SCL(bit) 904 905 If <bit> is TRUE, sets the I2C clock line high. If it 906 is FALSE, it clears it (low). 907 908 I2C_DELAY 909 910 This delay is invoked four times per clock cycle so this 911 controls the rate of data transfer. The data rate thus 912 is 1 / (I2C_DELAY * 4). 913 914 CFG_I2C_INIT_BOARD 915 916 When a board is reset during an i2c bus transfer 917 chips might think that the current transfer is still 918 in progress. On some boards it is possible to access 919 the i2c SCLK line directly, either by using the 920 processor pin as a GPIO or by having a second pin 921 connected to the bus. If this option is defined a 922 custom i2c_init_board() routine in boards/xxx/board.c 923 is run early in the boot sequence. 924 925- SPI Support: CONFIG_SPI 926 927 Enables SPI driver (so far only tested with 928 SPI EEPROM, also an instance works with Crystal A/D and 929 D/As on the SACSng board) 930 931 CONFIG_SPI_X 932 933 Enables extended (16-bit) SPI EEPROM addressing. 934 (symmetrical to CONFIG_I2C_X) 935 936 CONFIG_SOFT_SPI 937 938 Enables a software (bit-bang) SPI driver rather than 939 using hardware support. This is a general purpose 940 driver that only requires three general I/O port pins 941 (two outputs, one input) to function. If this is 942 defined, the board configuration must define several 943 SPI configuration items (port pins to use, etc). For 944 an example, see include/configs/sacsng.h. 945 946- FPGA Support: CONFIG_FPGA_COUNT 947 948 Specify the number of FPGA devices to support. 949 950 CONFIG_FPGA 951 952 Used to specify the types of FPGA devices. For 953 example, 954 #define CONFIG_FPGA CFG_XILINX_VIRTEX2 955 956 CFG_FPGA_PROG_FEEDBACK 957 958 Enable printing of hash marks during FPGA 959 configuration. 960 961 CFG_FPGA_CHECK_BUSY 962 963 Enable checks on FPGA configuration interface busy 964 status by the configuration function. This option 965 will require a board or device specific function to 966 be written. 967 968 CONFIG_FPGA_DELAY 969 970 If defined, a function that provides delays in the 971 FPGA configuration driver. 972 973 CFG_FPGA_CHECK_CTRLC 974 975 Allow Control-C to interrupt FPGA configuration 976 977 CFG_FPGA_CHECK_ERROR 978 979 Check for configuration errors during FPGA bitfile 980 loading. For example, abort during Virtex II 981 configuration if the INIT_B line goes low (which 982 indicated a CRC error). 983 984 CFG_FPGA_WAIT_INIT 985 986 Maximum time to wait for the INIT_B line to deassert 987 after PROB_B has been deasserted during a Virtex II 988 FPGA configuration sequence. The default time is 500 mS. 989 990 CFG_FPGA_WAIT_BUSY 991 992 Maximum time to wait for BUSY to deassert during 993 Virtex II FPGA configuration. The default is 5 mS. 994 995 CFG_FPGA_WAIT_CONFIG 996 997 Time to wait after FPGA configuration. The default is 998 200 mS. 999 1000- FPGA Support: CONFIG_FPGA_COUNT 1001 1002 Specify the number of FPGA devices to support. 1003 1004 CONFIG_FPGA 1005 1006 Used to specify the types of FPGA devices. For example, 1007 #define CONFIG_FPGA CFG_XILINX_VIRTEX2 1008 1009 CFG_FPGA_PROG_FEEDBACK 1010 1011 Enable printing of hash marks during FPGA configuration. 1012 1013 CFG_FPGA_CHECK_BUSY 1014 1015 Enable checks on FPGA configuration interface busy 1016 status by the configuration function. This option 1017 will require a board or device specific function to 1018 be written. 1019 1020 CONFIG_FPGA_DELAY 1021 1022 If defined, a function that provides delays in the FPGA 1023 configuration driver. 1024 1025 CFG_FPGA_CHECK_CTRLC 1026 Allow Control-C to interrupt FPGA configuration 1027 1028 CFG_FPGA_CHECK_ERROR 1029 1030 Check for configuration errors during FPGA bitfile 1031 loading. For example, abort during Virtex II 1032 configuration if the INIT_B line goes low (which 1033 indicated a CRC error). 1034 1035 CFG_FPGA_WAIT_INIT 1036 1037 Maximum time to wait for the INIT_B line to deassert 1038 after PROB_B has been deasserted during a Virtex II 1039 FPGA configuration sequence. The default time is 500 1040 mS. 1041 1042 CFG_FPGA_WAIT_BUSY 1043 1044 Maximum time to wait for BUSY to deassert during 1045 Virtex II FPGA configuration. The default is 5 mS. 1046 1047 CFG_FPGA_WAIT_CONFIG 1048 1049 Time to wait after FPGA configuration. The default is 1050 200 mS. 1051 1052- Configuration Management: 1053 CONFIG_IDENT_STRING 1054 1055 If defined, this string will be added to the U-Boot 1056 version information (U_BOOT_VERSION) 1057 1058- Vendor Parameter Protection: 1059 1060 U-Boot considers the values of the environment 1061 variables "serial#" (Board Serial Number) and 1062 "ethaddr" (Ethernet Address) to bb parameters that 1063 are set once by the board vendor / manufacturer, and 1064 protects these variables from casual modification by 1065 the user. Once set, these variables are read-only, 1066 and write or delete attempts are rejected. You can 1067 change this behviour: 1068 1069 If CONFIG_ENV_OVERWRITE is #defined in your config 1070 file, the write protection for vendor parameters is 1071 completely disabled. Anybody can change or delete 1072 these parameters. 1073 1074 Alternatively, if you #define _both_ CONFIG_ETHADDR 1075 _and_ CONFIG_OVERWRITE_ETHADDR_ONCE, a default 1076 ethernet address is installed in the environment, 1077 which can be changed exactly ONCE by the user. [The 1078 serial# is unaffected by this, i. e. it remains 1079 read-only.] 1080 1081- Protected RAM: 1082 CONFIG_PRAM 1083 1084 Define this variable to enable the reservation of 1085 "protected RAM", i. e. RAM which is not overwritten 1086 by U-Boot. Define CONFIG_PRAM to hold the number of 1087 kB you want to reserve for pRAM. You can overwrite 1088 this default value by defining an environment 1089 variable "pram" to the number of kB you want to 1090 reserve. Note that the board info structure will 1091 still show the full amount of RAM. If pRAM is 1092 reserved, a new environment variable "mem" will 1093 automatically be defined to hold the amount of 1094 remaining RAM in a form that can be passed as boot 1095 argument to Linux, for instance like that: 1096 1097 setenv bootargs ... mem=\$(mem) 1098 saveenv 1099 1100 This way you can tell Linux not to use this memory, 1101 either, which results in a memory region that will 1102 not be affected by reboots. 1103 1104 *WARNING* If your board configuration uses automatic 1105 detection of the RAM size, you must make sure that 1106 this memory test is non-destructive. So far, the 1107 following board configurations are known to be 1108 "pRAM-clean": 1109 1110 ETX094, IVMS8, IVML24, SPD8xx, TQM8xxL, 1111 HERMES, IP860, RPXlite, LWMON, LANTEC, 1112 PCU_E, FLAGADM, TQM8260 1113 1114- Error Recovery: 1115 CONFIG_PANIC_HANG 1116 1117 Define this variable to stop the system in case of a 1118 fatal error, so that you have to reset it manually. 1119 This is probably NOT a good idea for an embedded 1120 system where you want to system to reboot 1121 automatically as fast as possible, but it may be 1122 useful during development since you can try to debug 1123 the conditions that lead to the situation. 1124 1125 CONFIG_NET_RETRY_COUNT 1126 1127 This variable defines the number of retries for 1128 network operations like ARP, RARP, TFTP, or BOOTP 1129 before giving up the operation. If not defined, a 1130 default value of 5 is used. 1131 1132- Command Interpreter: 1133 CFG_HUSH_PARSER 1134 1135 Define this variable to enable the "hush" shell (from 1136 Busybox) as command line interpreter, thus enabling 1137 powerful command line syntax like 1138 if...then...else...fi conditionals or `&&' and '||' 1139 constructs ("shell scripts"). 1140 1141 If undefined, you get the old, much simpler behaviour 1142 with a somewhat smaller memory footprint. 1143 1144 1145 CFG_PROMPT_HUSH_PS2 1146 1147 This defines the secondary prompt string, which is 1148 printed when the command interpreter needs more input 1149 to complete a command. Usually "> ". 1150 1151 Note: 1152 1153 In the current implementation, the local variables 1154 space and global environment variables space are 1155 separated. Local variables are those you define by 1156 simply typing like `name=value'. To access a local 1157 variable later on, you have write `$name' or 1158 `${name}'; variable directly by typing say `$name' at 1159 the command prompt. 1160 1161 Global environment variables are those you use 1162 setenv/printenv to work with. To run a command stored 1163 in such a variable, you need to use the run command, 1164 and you must not use the '$' sign to access them. 1165 1166 To store commands and special characters in a 1167 variable, please use double quotation marks 1168 surrounding the whole text of the variable, instead 1169 of the backslashes before semicolons and special 1170 symbols. 1171 1172- Default Environment 1173 CONFIG_EXTRA_ENV_SETTINGS 1174 1175 Define this to contain any number of null terminated 1176 strings (variable = value pairs) that will be part of 1177 the default enviroment compiled into the boot image. 1178 1179 For example, place something like this in your 1180 board's config file: 1181 1182 #define CONFIG_EXTRA_ENV_SETTINGS \ 1183 "myvar1=value1\0" \ 1184 "myvar2=value2\0" 1185 1186 Warning: This method is based on knowledge about the 1187 internal format how the environment is stored by the 1188 U-Boot code. This is NOT an official, exported 1189 interface! Although it is unlikely that this format 1190 will change soon, but there is no guarantee either. 1191 You better know what you are doing here. 1192 1193 Note: overly (ab)use of the default environment is 1194 discouraged. Make sure to check other ways to preset 1195 the environment like the autoscript function or the 1196 boot command first. 1197 1198- Show boot progress 1199 CONFIG_SHOW_BOOT_PROGRESS 1200 1201 Defining this option allows to add some board- 1202 specific code (calling a user-provided function 1203 "show_boot_progress(int)") that enables you to show 1204 the system's boot progress on some display (for 1205 example, some LED's) on your board. At the moment, 1206 the following checkpoints are implemented: 1207 1208 Arg Where When 1209 1 common/cmd_bootm.c before attempting to boot an image 1210 -1 common/cmd_bootm.c Image header has bad magic number 1211 2 common/cmd_bootm.c Image header has correct magic number 1212 -2 common/cmd_bootm.c Image header has bad checksum 1213 3 common/cmd_bootm.c Image header has correct checksum 1214 -3 common/cmd_bootm.c Image data has bad checksum 1215 4 common/cmd_bootm.c Image data has correct checksum 1216 -4 common/cmd_bootm.c Image is for unsupported architecture 1217 5 common/cmd_bootm.c Architecture check OK 1218 -5 common/cmd_bootm.c Wrong Image Type (not kernel, multi, standalone) 1219 6 common/cmd_bootm.c Image Type check OK 1220 -6 common/cmd_bootm.c gunzip uncompression error 1221 -7 common/cmd_bootm.c Unimplemented compression type 1222 7 common/cmd_bootm.c Uncompression OK 1223 -8 common/cmd_bootm.c Wrong Image Type (not kernel, multi, standalone) 1224 8 common/cmd_bootm.c Image Type check OK 1225 -9 common/cmd_bootm.c Unsupported OS (not Linux, BSD, VxWorks, QNX) 1226 9 common/cmd_bootm.c Start initial ramdisk verification 1227 -10 common/cmd_bootm.c Ramdisk header has bad magic number 1228 -11 common/cmd_bootm.c Ramdisk header has bad checksum 1229 10 common/cmd_bootm.c Ramdisk header is OK 1230 -12 common/cmd_bootm.c Ramdisk data has bad checksum 1231 11 common/cmd_bootm.c Ramdisk data has correct checksum 1232 12 common/cmd_bootm.c Ramdisk verification complete, start loading 1233 -13 common/cmd_bootm.c Wrong Image Type (not PPC Linux Ramdisk) 1234 13 common/cmd_bootm.c Start multifile image verification 1235 14 common/cmd_bootm.c No initial ramdisk, no multifile, continue. 1236 15 common/cmd_bootm.c All preparation done, transferring control to OS 1237 1238 -1 common/cmd_doc.c Bad usage of "doc" command 1239 -1 common/cmd_doc.c No boot device 1240 -1 common/cmd_doc.c Unknown Chip ID on boot device 1241 -1 common/cmd_doc.c Read Error on boot device 1242 -1 common/cmd_doc.c Image header has bad magic number 1243 1244 -1 common/cmd_ide.c Bad usage of "ide" command 1245 -1 common/cmd_ide.c No boot device 1246 -1 common/cmd_ide.c Unknown boot device 1247 -1 common/cmd_ide.c Unknown partition table 1248 -1 common/cmd_ide.c Invalid partition type 1249 -1 common/cmd_ide.c Read Error on boot device 1250 -1 common/cmd_ide.c Image header has bad magic number 1251 1252 -1 common/cmd_nvedit.c Environment not changable, but has bad CRC 1253 1254 1255Modem Support: 1256-------------- 1257 1258[so far only for SMDK2400 and TRAB boards] 1259 1260- Modem support endable: 1261 CONFIG_MODEM_SUPPORT 1262 1263- RTS/CTS Flow control enable: 1264 CONFIG_HWFLOW 1265 1266- Modem debug support: 1267 CONFIG_MODEM_SUPPORT_DEBUG 1268 1269 Enables debugging stuff (char screen[1024], dbg()) 1270 for modem support. Useful only with BDI2000. 1271 1272- General: 1273 1274 In the target system modem support is enabled when a 1275 specific key (key combination) is pressed during 1276 power-on. Otherwise U-Boot will boot normally 1277 (autoboot). The key_pressed() fuction is called from 1278 board_init(). Currently key_pressed() is a dummy 1279 function, returning 1 and thus enabling modem 1280 initialization. 1281 1282 If there are no modem init strings in the 1283 environment, U-Boot proceed to autoboot; the 1284 previous output (banner, info printfs) will be 1285 supressed, though. 1286 1287 See also: doc/README.Modem 1288 1289 1290 1291 1292Configuration Settings: 1293----------------------- 1294 1295- CFG_LONGHELP: Defined when you want long help messages included; 1296 undefine this when you're short of memory. 1297 1298- CFG_PROMPT: This is what U-Boot prints on the console to 1299 prompt for user input. 1300 1301- CFG_CBSIZE: Buffer size for input from the Console 1302 1303- CFG_PBSIZE: Buffer size for Console output 1304 1305- CFG_MAXARGS: max. Number of arguments accepted for monitor commands 1306 1307- CFG_BARGSIZE: Buffer size for Boot Arguments which are passed to 1308 the application (usually a Linux kernel) when it is 1309 booted 1310 1311- CFG_BAUDRATE_TABLE: 1312 List of legal baudrate settings for this board. 1313 1314- CFG_CONSOLE_INFO_QUIET 1315 Suppress display of console information at boot. 1316 1317- CFG_CONSOLE_IS_IN_ENV 1318 If the board specific function 1319 extern int overwrite_console (void); 1320 returns 1, the stdin, stderr and stdout are switched to the 1321 serial port, else the settings in the environment are used. 1322 1323- CFG_CONSOLE_OVERWRITE_ROUTINE 1324 Enable the call to overwrite_console(). 1325 1326- CFG_CONSOLE_ENV_OVERWRITE 1327 Enable overwrite of previous console environment settings. 1328 1329- CFG_MEMTEST_START, CFG_MEMTEST_END: 1330 Begin and End addresses of the area used by the 1331 simple memory test. 1332 1333- CFG_ALT_MEMTEST: 1334 Enable an alternate, more extensive memory test. 1335 1336- CFG_TFTP_LOADADDR: 1337 Default load address for network file downloads 1338 1339- CFG_LOADS_BAUD_CHANGE: 1340 Enable temporary baudrate change while serial download 1341 1342- CFG_SDRAM_BASE: 1343 Physical start address of SDRAM. _Must_ be 0 here. 1344 1345- CFG_MBIO_BASE: 1346 Physical start address of Motherboard I/O (if using a 1347 Cogent motherboard) 1348 1349- CFG_FLASH_BASE: 1350 Physical start address of Flash memory. 1351 1352- CFG_MONITOR_BASE: 1353 Physical start address of boot monitor code (set by 1354 make config files to be same as the text base address 1355 (TEXT_BASE) used when linking) - same as 1356 CFG_FLASH_BASE when booting from flash. 1357 1358- CFG_MONITOR_LEN: 1359 Size of memory reserved for monitor code 1360 1361- CFG_MALLOC_LEN: 1362 Size of DRAM reserved for malloc() use. 1363 1364- CFG_BOOTMAPSZ: 1365 Maximum size of memory mapped by the startup code of 1366 the Linux kernel; all data that must be processed by 1367 the Linux kernel (bd_info, boot arguments, eventually 1368 initrd image) must be put below this limit. 1369 1370- CFG_MAX_FLASH_BANKS: 1371 Max number of Flash memory banks 1372 1373- CFG_MAX_FLASH_SECT: 1374 Max number of sectors on a Flash chip 1375 1376- CFG_FLASH_ERASE_TOUT: 1377 Timeout for Flash erase operations (in ms) 1378 1379- CFG_FLASH_WRITE_TOUT: 1380 Timeout for Flash write operations (in ms) 1381 1382- CFG_DIRECT_FLASH_TFTP: 1383 1384 Enable TFTP transfers directly to flash memory; 1385 without this option such a download has to be 1386 performed in two steps: (1) download to RAM, and (2) 1387 copy from RAM to flash. 1388 1389 The two-step approach is usually more reliable, since 1390 you can check if the download worked before you erase 1391 the flash, but in some situations (when sytem RAM is 1392 too limited to allow for a tempory copy of the 1393 downloaded image) this option may be very useful. 1394 1395- CFG_FLASH_CFI: 1396 Define if the flash driver uses extra elements in the 1397 common flash structure for storing flash geometry 1398 1399The following definitions that deal with the placement and management 1400of environment data (variable area); in general, we support the 1401following configurations: 1402 1403- CFG_ENV_IS_IN_FLASH: 1404 1405 Define this if the environment is in flash memory. 1406 1407 a) The environment occupies one whole flash sector, which is 1408 "embedded" in the text segment with the U-Boot code. This 1409 happens usually with "bottom boot sector" or "top boot 1410 sector" type flash chips, which have several smaller 1411 sectors at the start or the end. For instance, such a 1412 layout can have sector sizes of 8, 2x4, 16, Nx32 kB. In 1413 such a case you would place the environment in one of the 1414 4 kB sectors - with U-Boot code before and after it. With 1415 "top boot sector" type flash chips, you would put the 1416 environment in one of the last sectors, leaving a gap 1417 between U-Boot and the environment. 1418 1419 - CFG_ENV_OFFSET: 1420 1421 Offset of environment data (variable area) to the 1422 beginning of flash memory; for instance, with bottom boot 1423 type flash chips the second sector can be used: the offset 1424 for this sector is given here. 1425 1426 CFG_ENV_OFFSET is used relative to CFG_FLASH_BASE. 1427 1428 - CFG_ENV_ADDR: 1429 1430 This is just another way to specify the start address of 1431 the flash sector containing the environment (instead of 1432 CFG_ENV_OFFSET). 1433 1434 - CFG_ENV_SECT_SIZE: 1435 1436 Size of the sector containing the environment. 1437 1438 1439 b) Sometimes flash chips have few, equal sized, BIG sectors. 1440 In such a case you don't want to spend a whole sector for 1441 the environment. 1442 1443 - CFG_ENV_SIZE: 1444 1445 If you use this in combination with CFG_ENV_IS_IN_FLASH 1446 and CFG_ENV_SECT_SIZE, you can specify to use only a part 1447 of this flash sector for the environment. This saves 1448 memory for the RAM copy of the environment. 1449 1450 It may also save flash memory if you decide to use this 1451 when your environment is "embedded" within U-Boot code, 1452 since then the remainder of the flash sector could be used 1453 for U-Boot code. It should be pointed out that this is 1454 STRONGLY DISCOURAGED from a robustness point of view: 1455 updating the environment in flash makes it always 1456 necessary to erase the WHOLE sector. If something goes 1457 wrong before the contents has been restored from a copy in 1458 RAM, your target system will be dead. 1459 1460 - CFG_ENV_ADDR_REDUND 1461 CFG_ENV_SIZE_REDUND 1462 1463 These settings describe a second storage area used to hold 1464 a redundand copy of the environment data, so that there is 1465 a valid backup copy in case there is a power failure during 1466 a "saveenv" operation. 1467 1468BE CAREFUL! Any changes to the flash layout, and some changes to the 1469source code will make it necessary to adapt <board>/u-boot.lds* 1470accordingly! 1471 1472 1473- CFG_ENV_IS_IN_NVRAM: 1474 1475 Define this if you have some non-volatile memory device 1476 (NVRAM, battery buffered SRAM) which you want to use for the 1477 environment. 1478 1479 - CFG_ENV_ADDR: 1480 - CFG_ENV_SIZE: 1481 1482 These two #defines are used to determin the memory area you 1483 want to use for environment. It is assumed that this memory 1484 can just be read and written to, without any special 1485 provision. 1486 1487BE CAREFUL! The first access to the environment happens quite early 1488in U-Boot initalization (when we try to get the setting of for the 1489console baudrate). You *MUST* have mappend your NVRAM area then, or 1490U-Boot will hang. 1491 1492Please note that even with NVRAM we still use a copy of the 1493environment in RAM: we could work on NVRAM directly, but we want to 1494keep settings there always unmodified except somebody uses "saveenv" 1495to save the current settings. 1496 1497 1498- CFG_ENV_IS_IN_EEPROM: 1499 1500 Use this if you have an EEPROM or similar serial access 1501 device and a driver for it. 1502 1503 - CFG_ENV_OFFSET: 1504 - CFG_ENV_SIZE: 1505 1506 These two #defines specify the offset and size of the 1507 environment area within the total memory of your EEPROM. 1508 1509 - CFG_I2C_EEPROM_ADDR: 1510 If defined, specified the chip address of the EEPROM device. 1511 The default address is zero. 1512 1513 - CFG_EEPROM_PAGE_WRITE_BITS: 1514 If defined, the number of bits used to address bytes in a 1515 single page in the EEPROM device. A 64 byte page, for example 1516 would require six bits. 1517 1518 - CFG_EEPROM_PAGE_WRITE_DELAY_MS: 1519 If defined, the number of milliseconds to delay between 1520 page writes. The default is zero milliseconds. 1521 1522 - CFG_I2C_EEPROM_ADDR_LEN: 1523 The length in bytes of the EEPROM memory array address. Note 1524 that this is NOT the chip address length! 1525 1526 - CFG_EEPROM_SIZE: 1527 The size in bytes of the EEPROM device. 1528 1529 1530- CFG_SPI_INIT_OFFSET 1531 1532 Defines offset to the initial SPI buffer area in DPRAM. The 1533 area is used at an early stage (ROM part) if the environment 1534 is configured to reside in the SPI EEPROM: We need a 520 byte 1535 scratch DPRAM area. It is used between the two initialization 1536 calls (spi_init_f() and spi_init_r()). A value of 0xB00 seems 1537 to be a good choice since it makes it far enough from the 1538 start of the data area as well as from the stack pointer. 1539 1540Please note that the environment is read-only as long as the monitor 1541has been relocated to RAM and a RAM copy of the environment has been 1542created; also, when using EEPROM you will have to use getenv_r() 1543until then to read environment variables. 1544 1545The environment is protected by a CRC32 checksum. Before the monitor 1546is relocated into RAM, as a result of a bad CRC you will be working 1547with the compiled-in default environment - *silently*!!! [This is 1548necessary, because the first environment variable we need is the 1549"baudrate" setting for the console - if we have a bad CRC, we don't 1550have any device yet where we could complain.] 1551 1552Note: once the monitor has been relocated, then it will complain if 1553the default environment is used; a new CRC is computed as soon as you 1554use the "saveenv" command to store a valid environment. 1555 1556 1557Low Level (hardware related) configuration options: 1558--------------------------------------------------- 1559 1560- CFG_CACHELINE_SIZE: 1561 Cache Line Size of the CPU. 1562 1563- CFG_DEFAULT_IMMR: 1564 Default address of the IMMR after system reset. 1565 Needed on some 8260 systems (MPC8260ADS and RPXsuper) 1566 to be able to adjust the position of the IMMR 1567 register after a reset. 1568 1569- Floppy Disk Support: 1570 CFG_FDC_DRIVE_NUMBER 1571 1572 the default drive number (default value 0) 1573 1574 CFG_ISA_IO_STRIDE 1575 1576 defines the spacing between fdc chipset registers 1577 (default value 1) 1578 1579 CFG_ISA_IO_OFFSET 1580 1581 defines the offset of register from address. It 1582 depends on which part of the data bus is connected to 1583 the fdc chipset. (default value 0) 1584 1585 If CFG_ISA_IO_STRIDE CFG_ISA_IO_OFFSET and 1586 CFG_FDC_DRIVE_NUMBER are undefined, they take their 1587 default value. 1588 1589 if CFG_FDC_HW_INIT is defined, then the function 1590 fdc_hw_init() is called at the beginning of the FDC 1591 setup. fdc_hw_init() must be provided by the board 1592 source code. It is used to make hardware dependant 1593 initializations. 1594 1595- CFG_IMMR: Physical address of the Internal Memory Mapped 1596 Register; DO NOT CHANGE! (11-4) 1597 [MPC8xx systems only] 1598 1599- CFG_INIT_RAM_ADDR: 1600 1601 Start address of memory area tha can be used for 1602 initial data and stack; please note that this must be 1603 writable memory that is working WITHOUT special 1604 initialization, i. e. you CANNOT use normal RAM which 1605 will become available only after programming the 1606 memory controller and running certain initialization 1607 sequences. 1608 1609 U-Boot uses the following memory types: 1610 - MPC8xx and MPC8260: IMMR (internal memory of the CPU) 1611 - MPC824X: data cache 1612 - PPC4xx: data cache 1613 1614- CFG_GBL_DATA_OFFSET: 1615 1616 Offset of the initial data structure in the memory 1617 area defined by CFG_INIT_RAM_ADDR. Usually 1618 CFG_GBL_DATA_OFFSET is chosen such that the initial 1619 data is located at the end of the available space 1620 (sometimes written as (CFG_INIT_RAM_END - 1621 CFG_INIT_DATA_SIZE), and the initial stack is just 1622 below that area (growing from (CFG_INIT_RAM_ADDR + 1623 CFG_GBL_DATA_OFFSET) downward. 1624 1625 Note: 1626 On the MPC824X (or other systems that use the data 1627 cache for initial memory) the address chosen for 1628 CFG_INIT_RAM_ADDR is basically arbitrary - it must 1629 point to an otherwise UNUSED address space between 1630 the top of RAM and the start of the PCI space. 1631 1632- CFG_SIUMCR: SIU Module Configuration (11-6) 1633 1634- CFG_SYPCR: System Protection Control (11-9) 1635 1636- CFG_TBSCR: Time Base Status and Control (11-26) 1637 1638- CFG_PISCR: Periodic Interrupt Status and Control (11-31) 1639 1640- CFG_PLPRCR: PLL, Low-Power, and Reset Control Register (15-30) 1641 1642- CFG_SCCR: System Clock and reset Control Register (15-27) 1643 1644- CFG_OR_TIMING_SDRAM: 1645 SDRAM timing 1646 1647- CFG_MAMR_PTA: 1648 periodic timer for refresh 1649 1650- CFG_DER: Debug Event Register (37-47) 1651 1652- FLASH_BASE0_PRELIM, FLASH_BASE1_PRELIM, CFG_REMAP_OR_AM, 1653 CFG_PRELIM_OR_AM, CFG_OR_TIMING_FLASH, CFG_OR0_REMAP, 1654 CFG_OR0_PRELIM, CFG_BR0_PRELIM, CFG_OR1_REMAP, CFG_OR1_PRELIM, 1655 CFG_BR1_PRELIM: 1656 Memory Controller Definitions: BR0/1 and OR0/1 (FLASH) 1657 1658- SDRAM_BASE2_PRELIM, SDRAM_BASE3_PRELIM, SDRAM_MAX_SIZE, 1659 CFG_OR_TIMING_SDRAM, CFG_OR2_PRELIM, CFG_BR2_PRELIM, 1660 CFG_OR3_PRELIM, CFG_BR3_PRELIM: 1661 Memory Controller Definitions: BR2/3 and OR2/3 (SDRAM) 1662 1663- CFG_MAMR_PTA, CFG_MPTPR_2BK_4K, CFG_MPTPR_1BK_4K, CFG_MPTPR_2BK_8K, 1664 CFG_MPTPR_1BK_8K, CFG_MAMR_8COL, CFG_MAMR_9COL: 1665 Machine Mode Register and Memory Periodic Timer 1666 Prescaler definitions (SDRAM timing) 1667 1668- CFG_I2C_UCODE_PATCH, CFG_I2C_DPMEM_OFFSET [0x1FC0]: 1669 enable I2C microcode relocation patch (MPC8xx); 1670 define relocation offset in DPRAM [DSP2] 1671 1672- CFG_SPI_UCODE_PATCH, CFG_SPI_DPMEM_OFFSET [0x1FC0]: 1673 enable SPI microcode relocation patch (MPC8xx); 1674 define relocation offset in DPRAM [SCC4] 1675 1676- CFG_USE_OSCCLK: 1677 Use OSCM clock mode on MBX8xx board. Be careful, 1678 wrong setting might damage your board. Read 1679 doc/README.MBX before setting this variable! 1680 1681- CFG_CPM_POST_WORD_ADDR: (MPC8xx, MPC8260 only) 1682 Offset of the bootmode word in DPRAM used by post 1683 (Power On Self Tests). This definition overrides 1684 #define'd default value in commproc.h resp. 1685 cpm_8260.h. 1686 1687Building the Software: 1688====================== 1689 1690Building U-Boot has been tested in native PPC environments (on a 1691PowerBook G3 running LinuxPPC 2000) and in cross environments 1692(running RedHat 6.x and 7.x Linux on x86, Solaris 2.6 on a SPARC, and 1693NetBSD 1.5 on x86). 1694 1695If you are not using a native PPC environment, it is assumed that you 1696have the GNU cross compiling tools available in your path and named 1697with a prefix of "powerpc-linux-". If this is not the case, (e.g. if 1698you are using Monta Vista's Hard Hat Linux CDK 1.2) you must change 1699the definition of CROSS_COMPILE in Makefile. For HHL on a 4xx CPU, 1700change it to: 1701 1702 CROSS_COMPILE = ppc_4xx- 1703 1704 1705U-Boot is intended to be simple to build. After installing the 1706sources you must configure U-Boot for one specific board type. This 1707is done by typing: 1708 1709 make NAME_config 1710 1711where "NAME_config" is the name of one of the existing 1712configurations; the following names are supported: 1713 1714 ADCIOP_config GTH_config TQM850L_config 1715 ADS860_config IP860_config TQM855L_config 1716 AR405_config IVML24_config TQM860L_config 1717 CANBT_config IVMS8_config WALNUT405_config 1718 CPCI405_config LANTEC_config cogent_common_config 1719 CPCIISER4_config MBX_config cogent_mpc8260_config 1720 CU824_config MBX860T_config cogent_mpc8xx_config 1721 ESTEEM192E_config RPXlite_config hermes_config 1722 ETX094_config RPXsuper_config hymod_config 1723 FADS823_config SM850_config lwmon_config 1724 FADS850SAR_config SPD823TS_config pcu_e_config 1725 FADS860T_config SXNI855T_config rsdproto_config 1726 FPS850L_config Sandpoint8240_config sbc8260_config 1727 GENIETV_config TQM823L_config PIP405_config 1728 GEN860T_config EBONY_config FPS860L_config 1729 ELPT860_config cmi_mpc5xx_config 1730 1731Note: for some board special configuration names may exist; check if 1732 additional information is available from the board vendor; for 1733 instance, the TQM8xxL systems run normally at 50 MHz and use a 1734 SCC for 10baseT ethernet; there are also systems with 80 MHz 1735 CPU clock, and an optional Fast Ethernet module is available 1736 for CPU's with FEC. You can select such additional "features" 1737 when chosing the configuration, i. e. 1738 1739 make TQM860L_config 1740 - will configure for a plain TQM860L, i. e. 50MHz, no FEC 1741 1742 make TQM860L_FEC_config 1743 - will configure for a TQM860L at 50MHz with FEC for ethernet 1744 1745 make TQM860L_80MHz_config 1746 - will configure for a TQM860L at 80 MHz, with normal 10baseT 1747 interface 1748 1749 make TQM860L_FEC_80MHz_config 1750 - will configure for a TQM860L at 80 MHz with FEC for ethernet 1751 1752 make TQM823L_LCD_config 1753 - will configure for a TQM823L with U-Boot console on LCD 1754 1755 make TQM823L_LCD_80MHz_config 1756 - will configure for a TQM823L at 80 MHz with U-Boot console on LCD 1757 1758 etc. 1759 1760 1761 1762Finally, type "make all", and you should get some working U-Boot 1763images ready for downlod to / installation on your system: 1764 1765- "u-boot.bin" is a raw binary image 1766- "u-boot" is an image in ELF binary format 1767- "u-boot.srec" is in Motorola S-Record format 1768 1769 1770Please be aware that the Makefiles assume you are using GNU make, so 1771for instance on NetBSD you might need to use "gmake" instead of 1772native "make". 1773 1774 1775If the system board that you have is not listed, then you will need 1776to port U-Boot to your hardware platform. To do this, follow these 1777steps: 1778 17791. Add a new configuration option for your board to the toplevel 1780 "Makefile" and to the "MAKEALL" script, using the existing 1781 entries as examples. Note that here and at many other places 1782 boards and other names are listed alphabetically sorted. Please 1783 keep this order. 17842. Create a new directory to hold your board specific code. Add any 1785 files you need. In your board directory, you will need at least 1786 the "Makefile", a "<board>.c", "flash.c" and "u-boot.lds". 17873. Create a new configuration file "include/configs/<board>.h" for 1788 your board 17893. If you're porting U-Boot to a new CPU, then also create a new 1790 directory to hold your CPU specific code. Add any files you need. 17914. Run "make <board>_config" with your new name. 17925. Type "make", and you should get a working "u-boot.srec" file 1793 to be installed on your target system. 17946. Debug and solve any problems that might arise. 1795 [Of course, this last step is much harder than it sounds.] 1796 1797 1798Testing of U-Boot Modifications, Ports to New Hardware, etc.: 1799============================================================== 1800 1801If you have modified U-Boot sources (for instance added a new board 1802or support for new devices, a new CPU, etc.) you are expected to 1803provide feedback to the other developers. The feedback normally takes 1804the form of a "patch", i. e. a context diff against a certain (latest 1805official or latest in CVS) version of U-Boot sources. 1806 1807But before you submit such a patch, please verify that your modifi- 1808cation did not break existing code. At least make sure that *ALL* of 1809the supported boards compile WITHOUT ANY compiler warnings. To do so, 1810just run the "MAKEALL" script, which will configure and build U-Boot 1811for ALL supported system. Be warned, this will take a while. You can 1812select which (cross) compiler to use py passing a `CROSS_COMPILE' 1813environment variable to the script, i. e. to use the cross tools from 1814MontaVista's Hard Hat Linux you can type 1815 1816 CROSS_COMPILE=ppc_8xx- MAKEALL 1817 1818or to build on a native PowerPC system you can type 1819 1820 CROSS_COMPILE=' ' MAKEALL 1821 1822See also "U-Boot Porting Guide" below. 1823 1824 1825 1826Monitor Commands - Overview: 1827============================ 1828 1829go - start application at address 'addr' 1830run - run commands in an environment variable 1831bootm - boot application image from memory 1832bootp - boot image via network using BootP/TFTP protocol 1833tftpboot- boot image via network using TFTP protocol 1834 and env variables "ipaddr" and "serverip" 1835 (and eventually "gatewayip") 1836rarpboot- boot image via network using RARP/TFTP protocol 1837diskboot- boot from IDE devicebootd - boot default, i.e., run 'bootcmd' 1838loads - load S-Record file over serial line 1839loadb - load binary file over serial line (kermit mode) 1840md - memory display 1841mm - memory modify (auto-incrementing) 1842nm - memory modify (constant address) 1843mw - memory write (fill) 1844cp - memory copy 1845cmp - memory compare 1846crc32 - checksum calculation 1847imd - i2c memory display 1848imm - i2c memory modify (auto-incrementing) 1849inm - i2c memory modify (constant address) 1850imw - i2c memory write (fill) 1851icrc32 - i2c checksum calculation 1852iprobe - probe to discover valid I2C chip addresses 1853iloop - infinite loop on address range 1854isdram - print SDRAM configuration information 1855sspi - SPI utility commands 1856base - print or set address offset 1857printenv- print environment variables 1858setenv - set environment variables 1859saveenv - save environment variables to persistent storage 1860protect - enable or disable FLASH write protection 1861erase - erase FLASH memory 1862flinfo - print FLASH memory information 1863bdinfo - print Board Info structure 1864iminfo - print header information for application image 1865coninfo - print console devices and informations 1866ide - IDE sub-system 1867loop - infinite loop on address range 1868mtest - simple RAM test 1869icache - enable or disable instruction cache 1870dcache - enable or disable data cache 1871reset - Perform RESET of the CPU 1872echo - echo args to console 1873version - print monitor version 1874help - print online help 1875? - alias for 'help' 1876 1877 1878Monitor Commands - Detailed Description: 1879======================================== 1880 1881TODO. 1882 1883For now: just type "help <command>". 1884 1885 1886Environment Variables: 1887====================== 1888 1889U-Boot supports user configuration using Environment Variables which 1890can be made persistent by saving to Flash memory. 1891 1892Environment Variables are set using "setenv", printed using 1893"printenv", and saved to Flash using "saveenv". Using "setenv" 1894without a value can be used to delete a variable from the 1895environment. As long as you don't save the environment you are 1896working with an in-memory copy. In case the Flash area containing the 1897environment is erased by accident, a default environment is provided. 1898 1899Some configuration options can be set using Environment Variables: 1900 1901 baudrate - see CONFIG_BAUDRATE 1902 1903 bootdelay - see CONFIG_BOOTDELAY 1904 1905 bootcmd - see CONFIG_BOOTCOMMAND 1906 1907 bootargs - Boot arguments when booting an RTOS image 1908 1909 bootfile - Name of the image to load with TFTP 1910 1911 autoload - if set to "no" (any string beginning with 'n'), 1912 "bootp" will just load perform a lookup of the 1913 configuration from the BOOTP server, but not try to 1914 load any image using TFTP 1915 1916 autostart - if set to "yes", an image loaded using the "bootp", 1917 "rarpboot", "tftpboot" or "diskboot" commands will 1918 be automatically started (by internally calling 1919 "bootm") 1920 1921 initrd_high - restrict positioning of initrd images: 1922 If this variable is not set, initrd images will be 1923 copied to the highest possible address in RAM; this 1924 is usually what you want since it allows for 1925 maximum initrd size. If for some reason you want to 1926 make sure that the initrd image is loaded below the 1927 CFG_BOOTMAPSZ limit, you can set this environment 1928 variable to a value of "no" or "off" or "0". 1929 Alternatively, you can set it to a maximum upper 1930 address to use (U-Boot will still check that it 1931 does not overwrite the U-Boot stack and data). 1932 1933 For instance, when you have a system with 16 MB 1934 RAM, and want to reseve 4 MB from use by Linux, 1935 you can do this by adding "mem=12M" to the value of 1936 the "bootargs" variable. However, now you must make 1937 sure, that the initrd image is placed in the first 1938 12 MB as well - this can be done with 1939 1940 setenv initrd_high 00c00000 1941 1942 ipaddr - IP address; needed for tftpboot command 1943 1944 loadaddr - Default load address for commands like "bootp", 1945 "rarpboot", "tftpboot", "loadb" or "diskboot" 1946 1947 loads_echo - see CONFIG_LOADS_ECHO 1948 1949 serverip - TFTP server IP address; needed for tftpboot command 1950 1951 bootretry - see CONFIG_BOOT_RETRY_TIME 1952 1953 bootdelaykey - see CONFIG_AUTOBOOT_DELAY_STR 1954 1955 bootstopkey - see CONFIG_AUTOBOOT_STOP_STR 1956 1957 1958The following environment variables may be used and automatically 1959updated by the network boot commands ("bootp" and "rarpboot"), 1960depending the information provided by your boot server: 1961 1962 bootfile - see above 1963 dnsip - IP address of your Domain Name Server 1964 gatewayip - IP address of the Gateway (Router) to use 1965 hostname - Target hostname 1966 ipaddr - see above 1967 netmask - Subnet Mask 1968 rootpath - Pathname of the root filesystem on the NFS server 1969 serverip - see above 1970 1971 1972There are two special Environment Variables: 1973 1974 serial# - contains hardware identification information such 1975 as type string and/or serial number 1976 ethaddr - Ethernet address 1977 1978These variables can be set only once (usually during manufacturing of 1979the board). U-Boot refuses to delete or overwrite these variables 1980once they have been set once. 1981 1982 1983Further special Environment Variables: 1984 1985 ver - Contains the U-Boot version string as printed 1986 with the "version" command. This variable is 1987 readonly (see CONFIG_VERSION_VARIABLE). 1988 1989 1990Please note that changes to some configuration parameters may take 1991only effect after the next boot (yes, that's just like Windoze :-). 1992 1993 1994Note for Redundant Ethernet Interfaces: 1995======================================= 1996 1997Some boards come with redundand ethernet interfaces; U-Boot supports 1998such configurations and is capable of automatic selection of a 1999"working" interface when needed. MAC assignemnt works as follows: 2000 2001Network interfaces are numbered eth0, eth1, eth2, ... Corresponding 2002MAC addresses can be stored in the environment as "ethaddr" (=>eth0), 2003"eth1addr" (=>eth1), "eth2addr", ... 2004 2005If the network interface stores some valid MAC address (for instance 2006in SROM), this is used as default address if there is NO correspon- 2007ding setting in the environment; if the corresponding environment 2008variable is set, this overrides the settings in the card; that means: 2009 2010o If the SROM has a valid MAC address, and there is no address in the 2011 environment, the SROM's address is used. 2012 2013o If there is no valid address in the SROM, and a definition in the 2014 environment exists, then the value from the environment variable is 2015 used. 2016 2017o If both the SROM and the environment contain a MAC address, and 2018 both addresses are the same, this MAC address is used. 2019 2020o If both the SROM and the environment contain a MAC address, and the 2021 addresses differ, the value from the environment is used and a 2022 warning is printed. 2023 2024o If neither SROM nor the environment contain a MAC address, an error 2025 is raised. 2026 2027 2028 2029Image Formats: 2030============== 2031 2032The "boot" commands of this monitor operate on "image" files which 2033can be basicly anything, preceeded by a special header; see the 2034definitions in include/image.h for details; basicly, the header 2035defines the following image properties: 2036 2037* Target Operating System (Provisions for OpenBSD, NetBSD, FreeBSD, 2038 4.4BSD, Linux, SVR4, Esix, Solaris, Irix, SCO, Dell, NCR, VxWorks, 2039 LynxOS, pSOS, QNX; 2040 Currently supported: Linux, NetBSD, VxWorks, QNX). 2041* Target CPU Architecture (Provisions for Alpha, ARM, Intel x86, 2042 IA64, MIPS, MIPS, PowerPC, IBM S390, SuperH, Sparc, Sparc 64 Bit; 2043 Currently supported: PowerPC). 2044* Compression Type (Provisions for uncompressed, gzip, bzip2; 2045 Currently supported: uncompressed, gzip). 2046* Load Address 2047* Entry Point 2048* Image Name 2049* Image Timestamp 2050 2051The header is marked by a special Magic Number, and both the header 2052and the data portions of the image are secured against corruption by 2053CRC32 checksums. 2054 2055 2056Linux Support: 2057============== 2058 2059Although U-Boot should support any OS or standalone application 2060easily, Linux has always been in the focus during the design of 2061U-Boot. 2062 2063U-Boot includes many features that so far have been part of some 2064special "boot loader" code within the Linux kernel. Also, any 2065"initrd" images to be used are no longer part of one big Linux image; 2066instead, kernel and "initrd" are separate images. This implementation 2067serves serveral purposes: 2068 2069- the same features can be used for other OS or standalone 2070 applications (for instance: using compressed images to reduce the 2071 Flash memory footprint) 2072 2073- it becomes much easier to port new Linux kernel versions because 2074 lots of low-level, hardware dependend stuff are done by U-Boot 2075 2076- the same Linux kernel image can now be used with different "initrd" 2077 images; of course this also means that different kernel images can 2078 be run with the same "initrd". This makes testing easier (you don't 2079 have to build a new "zImage.initrd" Linux image when you just 2080 change a file in your "initrd"). Also, a field-upgrade of the 2081 software is easier now. 2082 2083 2084Linux HOWTO: 2085============ 2086 2087Porting Linux to U-Boot based systems: 2088--------------------------------------- 2089 2090U-Boot cannot save you from doing all the necessary modifications to 2091configure the Linux device drivers for use with your target hardware 2092(no, we don't intend to provide a full virtual machine interface to 2093Linux :-). 2094 2095But now you can ignore ALL boot loader code (in arch/ppc/mbxboot). 2096 2097Just make sure your machine specific header file (for instance 2098include/asm-ppc/tqm8xx.h) includes the same definition of the Board 2099Information structure as we define in include/u-boot.h, and make 2100sure that your definition of IMAP_ADDR uses the same value as your 2101U-Boot configuration in CFG_IMMR. 2102 2103 2104Configuring the Linux kernel: 2105----------------------------- 2106 2107No specific requirements for U-Boot. Make sure you have some root 2108device (initial ramdisk, NFS) for your target system. 2109 2110 2111Building a Linux Image: 2112----------------------- 2113 2114With U-Boot, "normal" build targets like "zImage" or "bzImage" are 2115not used. If you use recent kernel source, a new build target 2116"uImage" will exist which automatically builds an image usable by 2117U-Boot. Most older kernels also have support for a "pImage" target, 2118which was introduced for our predecessor project PPCBoot and uses a 2119100% compatible format. 2120 2121Example: 2122 2123 make TQM850L_config 2124 make oldconfig 2125 make dep 2126 make uImage 2127 2128The "uImage" build target uses a special tool (in 'tools/mkimage') to 2129encapsulate a compressed Linux kernel image with header information, 2130CRC32 checksum etc. for use with U-Boot. This is what we are doing: 2131 2132* build a standard "vmlinux" kernel image (in ELF binary format): 2133 2134* convert the kernel into a raw binary image: 2135 2136 ${CROSS_COMPILE}-objcopy -O binary \ 2137 -R .note -R .comment \ 2138 -S vmlinux linux.bin 2139 2140* compress the binary image: 2141 2142 gzip -9 linux.bin 2143 2144* package compressed binary image for U-Boot: 2145 2146 mkimage -A ppc -O linux -T kernel -C gzip \ 2147 -a 0 -e 0 -n "Linux Kernel Image" \ 2148 -d linux.bin.gz uImage 2149 2150 2151The "mkimage" tool can also be used to create ramdisk images for use 2152with U-Boot, either separated from the Linux kernel image, or 2153combined into one file. "mkimage" encapsulates the images with a 64 2154byte header containing information about target architecture, 2155operating system, image type, compression method, entry points, time 2156stamp, CRC32 checksums, etc. 2157 2158"mkimage" can be called in two ways: to verify existing images and 2159print the header information, or to build new images. 2160 2161In the first form (with "-l" option) mkimage lists the information 2162contained in the header of an existing U-Boot image; this includes 2163checksum verification: 2164 2165 tools/mkimage -l image 2166 -l ==> list image header information 2167 2168The second form (with "-d" option) is used to build a U-Boot image 2169from a "data file" which is used as image payload: 2170 2171 tools/mkimage -A arch -O os -T type -C comp -a addr -e ep \ 2172 -n name -d data_file image 2173 -A ==> set architecture to 'arch' 2174 -O ==> set operating system to 'os' 2175 -T ==> set image type to 'type' 2176 -C ==> set compression type 'comp' 2177 -a ==> set load address to 'addr' (hex) 2178 -e ==> set entry point to 'ep' (hex) 2179 -n ==> set image name to 'name' 2180 -d ==> use image data from 'datafile' 2181 2182Right now, all Linux kernels use the same load address (0x00000000), 2183but the entry point address depends on the kernel version: 2184 2185- 2.2.x kernels have the entry point at 0x0000000C, 2186- 2.3.x and later kernels have the entry point at 0x00000000. 2187 2188So a typical call to build a U-Boot image would read: 2189 2190 -> tools/mkimage -n '2.4.4 kernel for TQM850L' \ 2191 > -A ppc -O linux -T kernel -C gzip -a 0 -e 0 \ 2192 > -d /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/ppc/coffboot/vmlinux.gz \ 2193 > examples/uImage.TQM850L 2194 Image Name: 2.4.4 kernel for TQM850L 2195 Created: Wed Jul 19 02:34:59 2000 2196 Image Type: PowerPC Linux Kernel Image (gzip compressed) 2197 Data Size: 335725 Bytes = 327.86 kB = 0.32 MB 2198 Load Address: 0x00000000 2199 Entry Point: 0x00000000 2200 2201To verify the contents of the image (or check for corruption): 2202 2203 -> tools/mkimage -l examples/uImage.TQM850L 2204 Image Name: 2.4.4 kernel for TQM850L 2205 Created: Wed Jul 19 02:34:59 2000 2206 Image Type: PowerPC Linux Kernel Image (gzip compressed) 2207 Data Size: 335725 Bytes = 327.86 kB = 0.32 MB 2208 Load Address: 0x00000000 2209 Entry Point: 0x00000000 2210 2211NOTE: for embedded systems where boot time is critical you can trade 2212speed for memory and install an UNCOMPRESSED image instead: this 2213needs more space in Flash, but boots much faster since it does not 2214need to be uncompressed: 2215 2216 -> gunzip /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/ppc/coffboot/vmlinux.gz 2217 -> tools/mkimage -n '2.4.4 kernel for TQM850L' \ 2218 > -A ppc -O linux -T kernel -C none -a 0 -e 0 \ 2219 > -d /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/ppc/coffboot/vmlinux \ 2220 > examples/uImage.TQM850L-uncompressed 2221 Image Name: 2.4.4 kernel for TQM850L 2222 Created: Wed Jul 19 02:34:59 2000 2223 Image Type: PowerPC Linux Kernel Image (uncompressed) 2224 Data Size: 792160 Bytes = 773.59 kB = 0.76 MB 2225 Load Address: 0x00000000 2226 Entry Point: 0x00000000 2227 2228 2229Similar you can build U-Boot images from a 'ramdisk.image.gz' file 2230when your kernel is intended to use an initial ramdisk: 2231 2232 -> tools/mkimage -n 'Simple Ramdisk Image' \ 2233 > -A ppc -O linux -T ramdisk -C gzip \ 2234 > -d /LinuxPPC/images/SIMPLE-ramdisk.image.gz examples/simple-initrd 2235 Image Name: Simple Ramdisk Image 2236 Created: Wed Jan 12 14:01:50 2000 2237 Image Type: PowerPC Linux RAMDisk Image (gzip compressed) 2238 Data Size: 566530 Bytes = 553.25 kB = 0.54 MB 2239 Load Address: 0x00000000 2240 Entry Point: 0x00000000 2241 2242 2243Installing a Linux Image: 2244------------------------- 2245 2246To downloading a U-Boot image over the serial (console) interface, 2247you must convert the image to S-Record format: 2248 2249 objcopy -I binary -O srec examples/image examples/image.srec 2250 2251The 'objcopy' does not understand the information in the U-Boot 2252image header, so the resulting S-Record file will be relative to 2253address 0x00000000. To load it to a given address, you need to 2254specify the target address as 'offset' parameter with the 'loads' 2255command. 2256 2257Example: install the image to address 0x40100000 (which on the 2258TQM8xxL is in the first Flash bank): 2259 2260 => erase 40100000 401FFFFF 2261 2262 .......... done 2263 Erased 8 sectors 2264 2265 => loads 40100000 2266 ## Ready for S-Record download ... 2267 ~>examples/image.srec 2268 1 2 3 4 5 6 7 8 9 10 11 12 13 ... 2269 ... 2270 15989 15990 15991 15992 2271 [file transfer complete] 2272 [connected] 2273 ## Start Addr = 0x00000000 2274 2275 2276You can check the success of the download using the 'iminfo' command; 2277this includes a checksum verification so you can be sure no data 2278corruption happened: 2279 2280 => imi 40100000 2281 2282 ## Checking Image at 40100000 ... 2283 Image Name: 2.2.13 for initrd on TQM850L 2284 Image Type: PowerPC Linux Kernel Image (gzip compressed) 2285 Data Size: 335725 Bytes = 327 kB = 0 MB 2286 Load Address: 00000000 2287 Entry Point: 0000000c 2288 Verifying Checksum ... OK 2289 2290 2291 2292Boot Linux: 2293----------- 2294 2295The "bootm" command is used to boot an application that is stored in 2296memory (RAM or Flash). In case of a Linux kernel image, the contents 2297of the "bootargs" environment variable is passed to the kernel as 2298parameters. You can check and modify this variable using the 2299"printenv" and "setenv" commands: 2300 2301 2302 => printenv bootargs 2303 bootargs=root=/dev/ram 2304 2305 => setenv bootargs root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2 2306 2307 => printenv bootargs 2308 bootargs=root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2 2309 2310 => bootm 40020000 2311 ## Booting Linux kernel at 40020000 ... 2312 Image Name: 2.2.13 for NFS on TQM850L 2313 Image Type: PowerPC Linux Kernel Image (gzip compressed) 2314 Data Size: 381681 Bytes = 372 kB = 0 MB 2315 Load Address: 00000000 2316 Entry Point: 0000000c 2317 Verifying Checksum ... OK 2318 Uncompressing Kernel Image ... OK 2319 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 2320 Boot arguments: root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2 2321 time_init: decrementer frequency = 187500000/60 2322 Calibrating delay loop... 49.77 BogoMIPS 2323 Memory: 15208k available (700k kernel code, 444k data, 32k init) [c0000000,c1000000] 2324 ... 2325 2326If you want to boot a Linux kernel with initial ram disk, you pass 2327the memory addreses of both the kernel and the initrd image (PPBCOOT 2328format!) to the "bootm" command: 2329 2330 => imi 40100000 40200000 2331 2332 ## Checking Image at 40100000 ... 2333 Image Name: 2.2.13 for initrd on TQM850L 2334 Image Type: PowerPC Linux Kernel Image (gzip compressed) 2335 Data Size: 335725 Bytes = 327 kB = 0 MB 2336 Load Address: 00000000 2337 Entry Point: 0000000c 2338 Verifying Checksum ... OK 2339 2340 ## Checking Image at 40200000 ... 2341 Image Name: Simple Ramdisk Image 2342 Image Type: PowerPC Linux RAMDisk Image (gzip compressed) 2343 Data Size: 566530 Bytes = 553 kB = 0 MB 2344 Load Address: 00000000 2345 Entry Point: 00000000 2346 Verifying Checksum ... OK 2347 2348 => bootm 40100000 40200000 2349 ## Booting Linux kernel at 40100000 ... 2350 Image Name: 2.2.13 for initrd on TQM850L 2351 Image Type: PowerPC Linux Kernel Image (gzip compressed) 2352 Data Size: 335725 Bytes = 327 kB = 0 MB 2353 Load Address: 00000000 2354 Entry Point: 0000000c 2355 Verifying Checksum ... OK 2356 Uncompressing Kernel Image ... OK 2357 ## Loading RAMDisk Image at 40200000 ... 2358 Image Name: Simple Ramdisk Image 2359 Image Type: PowerPC Linux RAMDisk Image (gzip compressed) 2360 Data Size: 566530 Bytes = 553 kB = 0 MB 2361 Load Address: 00000000 2362 Entry Point: 00000000 2363 Verifying Checksum ... OK 2364 Loading Ramdisk ... OK 2365 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 2366 Boot arguments: root=/dev/ram 2367 time_init: decrementer frequency = 187500000/60 2368 Calibrating delay loop... 49.77 BogoMIPS 2369 ... 2370 RAMDISK: Compressed image found at block 0 2371 VFS: Mounted root (ext2 filesystem). 2372 2373 bash# 2374 2375More About U-Boot Image Types: 2376------------------------------ 2377 2378U-Boot supports the following image types: 2379 2380 "Standalone Programs" are directly runnable in the environment 2381 provided by U-Boot; it is expected that (if they behave 2382 well) you can continue to work in U-Boot after return from 2383 the Standalone Program. 2384 "OS Kernel Images" are usually images of some Embedded OS which 2385 will take over control completely. Usually these programs 2386 will install their own set of exception handlers, device 2387 drivers, set up the MMU, etc. - this means, that you cannot 2388 expect to re-enter U-Boot except by resetting the CPU. 2389 "RAMDisk Images" are more or less just data blocks, and their 2390 parameters (address, size) are passed to an OS kernel that is 2391 being started. 2392 "Multi-File Images" contain several images, typically an OS 2393 (Linux) kernel image and one or more data images like 2394 RAMDisks. This construct is useful for instance when you want 2395 to boot over the network using BOOTP etc., where the boot 2396 server provides just a single image file, but you want to get 2397 for instance an OS kernel and a RAMDisk image. 2398 2399 "Multi-File Images" start with a list of image sizes, each 2400 image size (in bytes) specified by an "uint32_t" in network 2401 byte order. This list is terminated by an "(uint32_t)0". 2402 Immediately after the terminating 0 follow the images, one by 2403 one, all aligned on "uint32_t" boundaries (size rounded up to 2404 a multiple of 4 bytes). 2405 2406 "Firmware Images" are binary images containing firmware (like 2407 U-Boot or FPGA images) which usually will be programmed to 2408 flash memory. 2409 2410 "Script files" are command sequences that will be executed by 2411 U-Boot's command interpreter; this feature is especially 2412 useful when you configure U-Boot to use a real shell (hush) 2413 as command interpreter. 2414 2415 2416Standalone HOWTO: 2417================= 2418 2419One of the features of U-Boot is that you can dynamically load and 2420run "standalone" applications, which can use some resources of 2421U-Boot like console I/O functions or interrupt services. 2422 2423Two simple examples are included with the sources: 2424 2425"Hello World" Demo: 2426------------------- 2427 2428'examples/hello_world.c' contains a small "Hello World" Demo 2429application; it is automatically compiled when you build U-Boot. 2430It's configured to run at address 0x00040004, so you can play with it 2431like that: 2432 2433 => loads 2434 ## Ready for S-Record download ... 2435 ~>examples/hello_world.srec 2436 1 2 3 4 5 6 7 8 9 10 11 ... 2437 [file transfer complete] 2438 [connected] 2439 ## Start Addr = 0x00040004 2440 2441 => go 40004 Hello World! This is a test. 2442 ## Starting application at 0x00040004 ... 2443 Hello World 2444 argc = 7 2445 argv[0] = "40004" 2446 argv[1] = "Hello" 2447 argv[2] = "World!" 2448 argv[3] = "This" 2449 argv[4] = "is" 2450 argv[5] = "a" 2451 argv[6] = "test." 2452 argv[7] = "<NULL>" 2453 Hit any key to exit ... 2454 2455 ## Application terminated, rc = 0x0 2456 2457Another example, which demonstrates how to register a CPM interrupt 2458handler with the U-Boot code, can be found in 'examples/timer.c'. 2459Here, a CPM timer is set up to generate an interrupt every second. 2460The interrupt service routine is trivial, just printing a '.' 2461character, but this is just a demo program. The application can be 2462controlled by the following keys: 2463 2464 ? - print current values og the CPM Timer registers 2465 b - enable interrupts and start timer 2466 e - stop timer and disable interrupts 2467 q - quit application 2468 2469 => loads 2470 ## Ready for S-Record download ... 2471 ~>examples/timer.srec 2472 1 2 3 4 5 6 7 8 9 10 11 ... 2473 [file transfer complete] 2474 [connected] 2475 ## Start Addr = 0x00040004 2476 2477 => go 40004 2478 ## Starting application at 0x00040004 ... 2479 TIMERS=0xfff00980 2480 Using timer 1 2481 tgcr @ 0xfff00980, tmr @ 0xfff00990, trr @ 0xfff00994, tcr @ 0xfff00998, tcn @ 0xfff0099c, ter @ 0xfff009b0 2482 2483Hit 'b': 2484 [q, b, e, ?] Set interval 1000000 us 2485 Enabling timer 2486Hit '?': 2487 [q, b, e, ?] ........ 2488 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0xef6, ter=0x0 2489Hit '?': 2490 [q, b, e, ?] . 2491 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x2ad4, ter=0x0 2492Hit '?': 2493 [q, b, e, ?] . 2494 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x1efc, ter=0x0 2495Hit '?': 2496 [q, b, e, ?] . 2497 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x169d, ter=0x0 2498Hit 'e': 2499 [q, b, e, ?] ...Stopping timer 2500Hit 'q': 2501 [q, b, e, ?] ## Application terminated, rc = 0x0 2502 2503 2504 2505Minicom warning: 2506================ 2507 2508Over time, many people have reported problems when trying to used the 2509"minicom" terminal emulation program for serial download. I (wd) 2510consider minicom to be broken, and recommend not to use it. Under 2511Unix, I recommend to use CKermit for general purpose use (and 2512especially for kermit binary protocol download ("loadb" command), and 2513use "cu" for S-Record download ("loads" command). 2514 2515NetBSD Notes: 2516============= 2517 2518Starting at version 0.9.2, U-Boot supports NetBSD both as host 2519(build U-Boot) and target system (boots NetBSD/mpc8xx). 2520 2521Building requires a cross environment; it is known to work on 2522NetBSD/i386 with the cross-powerpc-netbsd-1.3 package (you will also 2523need gmake since the Makefiles are not compatible with BSD make). 2524Note that the cross-powerpc package does not install include files; 2525attempting to build U-Boot will fail because <machine/ansi.h> is 2526missing. This file has to be installed and patched manually: 2527 2528 # cd /usr/pkg/cross/powerpc-netbsd/include 2529 # mkdir powerpc 2530 # ln -s powerpc machine 2531 # cp /usr/src/sys/arch/powerpc/include/ansi.h powerpc/ansi.h 2532 # ${EDIT} powerpc/ansi.h ## must remove __va_list, _BSD_VA_LIST 2533 2534Native builds *don't* work due to incompatibilities between native 2535and U-Boot include files. 2536 2537Booting assumes that (the first part of) the image booted is a 2538stage-2 loader which in turn loads and then invokes the kernel 2539proper. Loader sources will eventually appear in the NetBSD source 2540tree (probably in sys/arc/mpc8xx/stand/u-boot_stage2/); in the 2541meantime, send mail to bruno@exet-ag.de and/or wd@denx.de for 2542details. 2543 2544 2545Implementation Internals: 2546========================= 2547 2548The following is not intended to be a complete description of every 2549implementation detail. However, it should help to understand the 2550inner workings of U-Boot and make it easier to port it to custom 2551hardware. 2552 2553 2554Initial Stack, Global Data: 2555--------------------------- 2556 2557The implementation of U-Boot is complicated by the fact that U-Boot 2558starts running out of ROM (flash memory), usually without access to 2559system RAM (because the memory controller is not initialized yet). 2560This means that we don't have writable Data or BSS segments, and BSS 2561is not initialized as zero. To be able to get a C environment working 2562at all, we have to allocate at least a minimal stack. Implementation 2563options for this are defined and restricted by the CPU used: Some CPU 2564models provide on-chip memory (like the IMMR area on MPC8xx and 2565MPC826x processors), on others (parts of) the data cache can be 2566locked as (mis-) used as memory, etc. 2567 2568 Chris Hallinan posted a good summy of these issues to the 2569 u-boot-users mailing list: 2570 2571 Subject: RE: [U-Boot-Users] RE: More On Memory Bank x (nothingness)? 2572 From: "Chris Hallinan" <clh@net1plus.com> 2573 Date: Mon, 10 Feb 2003 16:43:46 -0500 (22:43 MET) 2574 ... 2575 2576 Correct me if I'm wrong, folks, but the way I understand it 2577 is this: Using DCACHE as initial RAM for Stack, etc, does not 2578 require any physical RAM backing up the cache. The cleverness 2579 is that the cache is being used as a temporary supply of 2580 necessary storage before the SDRAM controller is setup. It's 2581 beyond the scope of this list to expain the details, but you 2582 can see how this works by studying the cache architecture and 2583 operation in the architecture and processor-specific manuals. 2584 2585 OCM is On Chip Memory, which I believe the 405GP has 4K. It 2586 is another option for the system designer to use as an 2587 initial stack/ram area prior to SDRAM being available. Either 2588 option should work for you. Using CS 4 should be fine if your 2589 board designers haven't used it for something that would 2590 cause you grief during the initial boot! It is frequently not 2591 used. 2592 2593 CFG_INIT_RAM_ADDR should be somewhere that won't interfere 2594 with your processor/board/system design. The default value 2595 you will find in any recent u-boot distribution in 2596 Walnut405.h should work for you. I'd set it to a value larger 2597 than your SDRAM module. If you have a 64MB SDRAM module, set 2598 it above 400_0000. Just make sure your board has no resources 2599 that are supposed to respond to that address! That code in 2600 start.S has been around a while and should work as is when 2601 you get the config right. 2602 2603 -Chris Hallinan 2604 DS4.COM, Inc. 2605 2606It is essential to remember this, since it has some impact on the C 2607code for the initialization procedures: 2608 2609* Initialized global data (data segment) is read-only. Do not attempt 2610 to write it. 2611 2612* Do not use any unitialized global data (or implicitely initialized 2613 as zero data - BSS segment) at all - this is undefined, initiali- 2614 zation is performed later (when relocationg to RAM). 2615 2616* Stack space is very limited. Avoid big data buffers or things like 2617 that. 2618 2619Having only the stack as writable memory limits means we cannot use 2620normal global data to share information beween the code. But it 2621turned out that the implementation of U-Boot can be greatly 2622simplified by making a global data structure (gd_t) available to all 2623functions. We could pass a pointer to this data as argument to _all_ 2624functions, but this would bloat the code. Instead we use a feature of 2625the GCC compiler (Global Register Variables) to share the data: we 2626place a pointer (gd) to the global data into a register which we 2627reserve for this purpose. 2628 2629When chosing a register for such a purpose we are restricted by the 2630relevant (E)ABI specifications for the current architecture, and by 2631GCC's implementation. 2632 2633For PowerPC, the following registers have specific use: 2634 R1: stack pointer 2635 R2: TOC pointer 2636 R3-R4: parameter passing and return values 2637 R5-R10: parameter passing 2638 R13: small data area pointer 2639 R30: GOT pointer 2640 R31: frame pointer 2641 2642 (U-Boot also uses R14 as internal GOT pointer.) 2643 2644 ==> U-Boot will use R29 to hold a pointer to the global data 2645 2646 Note: on PPC, we could use a static initializer (since the 2647 address of the global data structure is known at compile time), 2648 but it turned out that reserving a register results in somewhat 2649 smaller code - although the code savings are not that big (on 2650 average for all boards 752 bytes for the whole U-Boot image, 2651 624 text + 127 data). 2652 2653On ARM, the following registers are used: 2654 2655 R0: function argument word/integer result 2656 R1-R3: function argument word 2657 R9: GOT pointer 2658 R10: stack limit (used only if stack checking if enabled) 2659 R11: argument (frame) pointer 2660 R12: temporary workspace 2661 R13: stack pointer 2662 R14: link register 2663 R15: program counter 2664 2665 ==> U-Boot will use R8 to hold a pointer to the global data 2666 2667 2668 2669Memory Management: 2670------------------ 2671 2672U-Boot runs in system state and uses physical addresses, i.e. the 2673MMU is not used either for address mapping nor for memory protection. 2674 2675The available memory is mapped to fixed addresses using the memory 2676controller. In this process, a contiguous block is formed for each 2677memory type (Flash, SDRAM, SRAM), even when it consists of several 2678physical memory banks. 2679 2680U-Boot is installed in the first 128 kB of the first Flash bank (on 2681TQM8xxL modules this is the range 0x40000000 ... 0x4001FFFF). After 2682booting and sizing and initializing DRAM, the code relocates itself 2683to the upper end of DRAM. Immediately below the U-Boot code some 2684memory is reserved for use by malloc() [see CFG_MALLOC_LEN 2685configuration setting]. Below that, a structure with global Board 2686Info data is placed, followed by the stack (growing downward). 2687 2688Additionally, some exception handler code is copied to the low 8 kB 2689of DRAM (0x00000000 ... 0x00001FFF). 2690 2691So a typical memory configuration with 16 MB of DRAM could look like 2692this: 2693 2694 0x0000 0000 Exception Vector code 2695 : 2696 0x0000 1FFF 2697 0x0000 2000 Free for Application Use 2698 : 2699 : 2700 2701 : 2702 : 2703 0x00FB FF20 Monitor Stack (Growing downward) 2704 0x00FB FFAC Board Info Data and permanent copy of global data 2705 0x00FC 0000 Malloc Arena 2706 : 2707 0x00FD FFFF 2708 0x00FE 0000 RAM Copy of Monitor Code 2709 ... eventually: LCD or video framebuffer 2710 ... eventually: pRAM (Protected RAM - unchanged by reset) 2711 0x00FF FFFF [End of RAM] 2712 2713 2714System Initialization: 2715---------------------- 2716 2717In the reset configuration, U-Boot starts at the reset entry point 2718(on most PowerPC systens at address 0x00000100). Because of the reset 2719configuration for CS0# this is a mirror of the onboard Flash memory. 2720To be able to re-map memory U-Boot then jumps to it's link address. 2721To be able to implement the initialization code in C, a (small!) 2722initial stack is set up in the internal Dual Ported RAM (in case CPUs 2723which provide such a feature like MPC8xx or MPC8260), or in a locked 2724part of the data cache. After that, U-Boot initializes the CPU core, 2725the caches and the SIU. 2726 2727Next, all (potentially) available memory banks are mapped using a 2728preliminary mapping. For example, we put them on 512 MB boundaries 2729(multiples of 0x20000000: SDRAM on 0x00000000 and 0x20000000, Flash 2730on 0x40000000 and 0x60000000, SRAM on 0x80000000). Then UPM A is 2731programmed for SDRAM access. Using the temporary configuration, a 2732simple memory test is run that determines the size of the SDRAM 2733banks. 2734 2735When there is more than one SDRAM bank, and the banks are of 2736different size, the larger is mapped first. For equal size, the first 2737bank (CS2#) is mapped first. The first mapping is always for address 27380x00000000, with any additional banks following immediately to create 2739contiguous memory starting from 0. 2740 2741Then, the monitor installs itself at the upper end of the SDRAM area 2742and allocates memory for use by malloc() and for the global Board 2743Info data; also, the exception vector code is copied to the low RAM 2744pages, and the final stack is set up. 2745 2746Only after this relocation will you have a "normal" C environment; 2747until that you are restricted in several ways, mostly because you are 2748running from ROM, and because the code will have to be relocated to a 2749new address in RAM. 2750 2751 2752U-Boot Porting Guide: 2753---------------------- 2754 2755[Based on messages by Jerry Van Baren in the U-Boot-Users mailing 2756list, October 2002] 2757 2758 2759int main (int argc, char *argv[]) 2760{ 2761 sighandler_t no_more_time; 2762 2763 signal (SIGALRM, no_more_time); 2764 alarm (PROJECT_DEADLINE - toSec (3 * WEEK)); 2765 2766 if (available_money > available_manpower) { 2767 pay consultant to port U-Boot; 2768 return 0; 2769 } 2770 2771 Download latest U-Boot source; 2772 2773 Subscribe to u-boot-users mailing list; 2774 2775 if (clueless) { 2776 email ("Hi, I am new to U-Boot, how do I get started?"); 2777 } 2778 2779 while (learning) { 2780 Read the README file in the top level directory; 2781 Read http://www.denx.de/re/DPLG.html 2782 Read the source, Luke; 2783 } 2784 2785 if (available_money > toLocalCurrency ($2500)) { 2786 Buy a BDI2000; 2787 } else { 2788 Add a lot of aggravation and time; 2789 } 2790 2791 Create your own board support subdirectory; 2792 2793 Create your own board config file; 2794 2795 while (!running) { 2796 do { 2797 Add / modify source code; 2798 } until (compiles); 2799 Debug; 2800 if (clueless) 2801 email ("Hi, I am having problems..."); 2802 } 2803 Send patch file to Wolfgang; 2804 2805 return 0; 2806} 2807 2808void no_more_time (int sig) 2809{ 2810 hire_a_guru(); 2811} 2812 2813 2814 2815Coding Standards: 2816----------------- 2817 2818All contributions to U-Boot should conform to the Linux kernel 2819coding style; see the file "Documentation/CodingStyle" in your Linux 2820kernel source directory. 2821 2822Please note that U-Boot is implemented in C (and to some small parts 2823in Assembler); no C++ is used, so please do not use C++ style 2824comments (//) in your code. 2825 2826Submissions which do not conform to the standards may be returned 2827with a request to reformat the changes. 2828 2829 2830Submitting Patches: 2831------------------- 2832 2833Since the number of patches for U-Boot is growing, we need to 2834establish some rules. Submissions which do not conform to these rules 2835may be rejected, even when they contain important and valuable stuff. 2836 2837 2838When you send a patch, please include the following information with 2839it: 2840 2841* For bug fixes: a description of the bug and how your patch fixes 2842 this bug. Please try to include a way of demonstrating that the 2843 patch actually fixes something. 2844 2845* For new features: a description of the feature and your 2846 implementation. 2847 2848* A CHANGELOG entry as plaintext (separate from the patch) 2849 2850* For major contributions, your entry to the CREDITS file 2851 2852* When you add support for a new board, don't forget to add this 2853 board to the MAKEALL script, too. 2854 2855* If your patch adds new configuration options, don't forget to 2856 document these in the README file. 2857 2858* The patch itself. If you are accessing the CVS repository use "cvs 2859 update; cvs diff -puRN"; else, use "diff -purN OLD NEW". If your 2860 version of diff does not support these options, then get the latest 2861 version of GNU diff. 2862 2863 We accept patches as plain text, MIME attachments or as uuencoded 2864 gzipped text. 2865 2866Notes: 2867 2868* Before sending the patch, run the MAKEALL script on your patched 2869 source tree and make sure that no errors or warnings are reported 2870 for any of the boards. 2871 2872* Keep your modifications to the necessary minimum: A patch 2873 containing several unrelated changes or arbitrary reformats will be 2874 returned with a request to re-formatting / split it. 2875 2876* If you modify existing code, make sure that your new code does not 2877 add to the memory footprint of the code ;-) Small is beautiful! 2878 When adding new features, these should compile conditionally only 2879 (using #ifdef), and the resulting code with the new feature 2880 disabled must not need more memory than the old code without your 2881 modification. 2882