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 and GEN860T_SC 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- Spash Screen Support: CONFIG_SPLASH_SCREEN 793 794 If this option is set, the environment is checked for 795 a variable "splashimage". If found, the usual display 796 of logo, copyright and system information on the LCD 797 is supressed and the BMP image at the address 798 specified in "splashimage" is loaded instead. The 799 console is redirected to the "nulldev", too. This 800 allows for a "silent" boot where a splash screen is 801 loaded very quickly after power-on. 802 803 804- Ethernet address: 805 CONFIG_ETHADDR 806 CONFIG_ETH2ADDR 807 CONFIG_ETH3ADDR 808 809 Define a default value for ethernet address to use 810 for the respective ethernet interface, in case this 811 is not determined automatically. 812 813- IP address: 814 CONFIG_IPADDR 815 816 Define a default value for the IP address to use for 817 the default ethernet interface, in case this is not 818 determined through e.g. bootp. 819 820- Server IP address: 821 CONFIG_SERVERIP 822 823 Defines a default value for theIP address of a TFTP 824 server to contact when using the "tftboot" command. 825 826- BOOTP Recovery Mode: 827 CONFIG_BOOTP_RANDOM_DELAY 828 829 If you have many targets in a network that try to 830 boot using BOOTP, you may want to avoid that all 831 systems send out BOOTP requests at precisely the same 832 moment (which would happen for instance at recovery 833 from a power failure, when all systems will try to 834 boot, thus flooding the BOOTP server. Defining 835 CONFIG_BOOTP_RANDOM_DELAY causes a random delay to be 836 inserted before sending out BOOTP requests. The 837 following delays are insterted then: 838 839 1st BOOTP request: delay 0 ... 1 sec 840 2nd BOOTP request: delay 0 ... 2 sec 841 3rd BOOTP request: delay 0 ... 4 sec 842 4th and following 843 BOOTP requests: delay 0 ... 8 sec 844 845- Status LED: CONFIG_STATUS_LED 846 847 Several configurations allow to display the current 848 status using a LED. For instance, the LED will blink 849 fast while running U-Boot code, stop blinking as 850 soon as a reply to a BOOTP request was received, and 851 start blinking slow once the Linux kernel is running 852 (supported by a status LED driver in the Linux 853 kernel). Defining CONFIG_STATUS_LED enables this 854 feature in U-Boot. 855 856- CAN Support: CONFIG_CAN_DRIVER 857 858 Defining CONFIG_CAN_DRIVER enables CAN driver support 859 on those systems that support this (optional) 860 feature, like the TQM8xxL modules. 861 862- I2C Support: CONFIG_HARD_I2C | CONFIG_SOFT_I2C 863 864 Enables I2C serial bus commands. If this is selected, 865 either CONFIG_HARD_I2C or CONFIG_SOFT_I2C must be defined 866 to include the appropriate I2C driver. 867 868 See also: common/cmd_i2c.c for a description of the 869 command line interface. 870 871 872 CONFIG_HARD_I2C 873 874 Selects the CPM hardware driver for I2C. 875 876 CONFIG_SOFT_I2C 877 878 Use software (aka bit-banging) driver instead of CPM 879 or similar hardware support for I2C. This is configured 880 via the following defines. 881 882 I2C_INIT 883 884 (Optional). Any commands necessary to enable I2C 885 controller or configure ports. 886 887 I2C_PORT 888 889 (Only for MPC8260 CPU). The I/O port to use (the code 890 assumes both bits are on the same port). Valid values 891 are 0..3 for ports A..D. 892 893 I2C_ACTIVE 894 895 The code necessary to make the I2C data line active 896 (driven). If the data line is open collector, this 897 define can be null. 898 899 I2C_TRISTATE 900 901 The code necessary to make the I2C data line tri-stated 902 (inactive). If the data line is open collector, this 903 define can be null. 904 905 I2C_READ 906 907 Code that returns TRUE if the I2C data line is high, 908 FALSE if it is low. 909 910 I2C_SDA(bit) 911 912 If <bit> is TRUE, sets the I2C data line high. If it 913 is FALSE, it clears it (low). 914 915 I2C_SCL(bit) 916 917 If <bit> is TRUE, sets the I2C clock line high. If it 918 is FALSE, it clears it (low). 919 920 I2C_DELAY 921 922 This delay is invoked four times per clock cycle so this 923 controls the rate of data transfer. The data rate thus 924 is 1 / (I2C_DELAY * 4). 925 926 CFG_I2C_INIT_BOARD 927 928 When a board is reset during an i2c bus transfer 929 chips might think that the current transfer is still 930 in progress. On some boards it is possible to access 931 the i2c SCLK line directly, either by using the 932 processor pin as a GPIO or by having a second pin 933 connected to the bus. If this option is defined a 934 custom i2c_init_board() routine in boards/xxx/board.c 935 is run early in the boot sequence. 936 937- SPI Support: CONFIG_SPI 938 939 Enables SPI driver (so far only tested with 940 SPI EEPROM, also an instance works with Crystal A/D and 941 D/As on the SACSng board) 942 943 CONFIG_SPI_X 944 945 Enables extended (16-bit) SPI EEPROM addressing. 946 (symmetrical to CONFIG_I2C_X) 947 948 CONFIG_SOFT_SPI 949 950 Enables a software (bit-bang) SPI driver rather than 951 using hardware support. This is a general purpose 952 driver that only requires three general I/O port pins 953 (two outputs, one input) to function. If this is 954 defined, the board configuration must define several 955 SPI configuration items (port pins to use, etc). For 956 an example, see include/configs/sacsng.h. 957 958- FPGA Support: CONFIG_FPGA_COUNT 959 960 Specify the number of FPGA devices to support. 961 962 CONFIG_FPGA 963 964 Used to specify the types of FPGA devices. For 965 example, 966 #define CONFIG_FPGA CFG_XILINX_VIRTEX2 967 968 CFG_FPGA_PROG_FEEDBACK 969 970 Enable printing of hash marks during FPGA 971 configuration. 972 973 CFG_FPGA_CHECK_BUSY 974 975 Enable checks on FPGA configuration interface busy 976 status by the configuration function. This option 977 will require a board or device specific function to 978 be written. 979 980 CONFIG_FPGA_DELAY 981 982 If defined, a function that provides delays in the 983 FPGA configuration driver. 984 985 CFG_FPGA_CHECK_CTRLC 986 987 Allow Control-C to interrupt FPGA configuration 988 989 CFG_FPGA_CHECK_ERROR 990 991 Check for configuration errors during FPGA bitfile 992 loading. For example, abort during Virtex II 993 configuration if the INIT_B line goes low (which 994 indicated a CRC error). 995 996 CFG_FPGA_WAIT_INIT 997 998 Maximum time to wait for the INIT_B line to deassert 999 after PROB_B has been deasserted during a Virtex II 1000 FPGA configuration sequence. The default time is 500 mS. 1001 1002 CFG_FPGA_WAIT_BUSY 1003 1004 Maximum time to wait for BUSY to deassert during 1005 Virtex II FPGA configuration. The default is 5 mS. 1006 1007 CFG_FPGA_WAIT_CONFIG 1008 1009 Time to wait after FPGA configuration. The default is 1010 200 mS. 1011 1012- FPGA Support: CONFIG_FPGA_COUNT 1013 1014 Specify the number of FPGA devices to support. 1015 1016 CONFIG_FPGA 1017 1018 Used to specify the types of FPGA devices. For example, 1019 #define CONFIG_FPGA CFG_XILINX_VIRTEX2 1020 1021 CFG_FPGA_PROG_FEEDBACK 1022 1023 Enable printing of hash marks during FPGA configuration. 1024 1025 CFG_FPGA_CHECK_BUSY 1026 1027 Enable checks on FPGA configuration interface busy 1028 status by the configuration function. This option 1029 will require a board or device specific function to 1030 be written. 1031 1032 CONFIG_FPGA_DELAY 1033 1034 If defined, a function that provides delays in the FPGA 1035 configuration driver. 1036 1037 CFG_FPGA_CHECK_CTRLC 1038 Allow Control-C to interrupt FPGA configuration 1039 1040 CFG_FPGA_CHECK_ERROR 1041 1042 Check for configuration errors during FPGA bitfile 1043 loading. For example, abort during Virtex II 1044 configuration if the INIT_B line goes low (which 1045 indicated a CRC error). 1046 1047 CFG_FPGA_WAIT_INIT 1048 1049 Maximum time to wait for the INIT_B line to deassert 1050 after PROB_B has been deasserted during a Virtex II 1051 FPGA configuration sequence. The default time is 500 1052 mS. 1053 1054 CFG_FPGA_WAIT_BUSY 1055 1056 Maximum time to wait for BUSY to deassert during 1057 Virtex II FPGA configuration. The default is 5 mS. 1058 1059 CFG_FPGA_WAIT_CONFIG 1060 1061 Time to wait after FPGA configuration. The default is 1062 200 mS. 1063 1064- Configuration Management: 1065 CONFIG_IDENT_STRING 1066 1067 If defined, this string will be added to the U-Boot 1068 version information (U_BOOT_VERSION) 1069 1070- Vendor Parameter Protection: 1071 1072 U-Boot considers the values of the environment 1073 variables "serial#" (Board Serial Number) and 1074 "ethaddr" (Ethernet Address) to bb parameters that 1075 are set once by the board vendor / manufacturer, and 1076 protects these variables from casual modification by 1077 the user. Once set, these variables are read-only, 1078 and write or delete attempts are rejected. You can 1079 change this behviour: 1080 1081 If CONFIG_ENV_OVERWRITE is #defined in your config 1082 file, the write protection for vendor parameters is 1083 completely disabled. Anybody can change or delete 1084 these parameters. 1085 1086 Alternatively, if you #define _both_ CONFIG_ETHADDR 1087 _and_ CONFIG_OVERWRITE_ETHADDR_ONCE, a default 1088 ethernet address is installed in the environment, 1089 which can be changed exactly ONCE by the user. [The 1090 serial# is unaffected by this, i. e. it remains 1091 read-only.] 1092 1093- Protected RAM: 1094 CONFIG_PRAM 1095 1096 Define this variable to enable the reservation of 1097 "protected RAM", i. e. RAM which is not overwritten 1098 by U-Boot. Define CONFIG_PRAM to hold the number of 1099 kB you want to reserve for pRAM. You can overwrite 1100 this default value by defining an environment 1101 variable "pram" to the number of kB you want to 1102 reserve. Note that the board info structure will 1103 still show the full amount of RAM. If pRAM is 1104 reserved, a new environment variable "mem" will 1105 automatically be defined to hold the amount of 1106 remaining RAM in a form that can be passed as boot 1107 argument to Linux, for instance like that: 1108 1109 setenv bootargs ... mem=\$(mem) 1110 saveenv 1111 1112 This way you can tell Linux not to use this memory, 1113 either, which results in a memory region that will 1114 not be affected by reboots. 1115 1116 *WARNING* If your board configuration uses automatic 1117 detection of the RAM size, you must make sure that 1118 this memory test is non-destructive. So far, the 1119 following board configurations are known to be 1120 "pRAM-clean": 1121 1122 ETX094, IVMS8, IVML24, SPD8xx, TQM8xxL, 1123 HERMES, IP860, RPXlite, LWMON, LANTEC, 1124 PCU_E, FLAGADM, TQM8260 1125 1126- Error Recovery: 1127 CONFIG_PANIC_HANG 1128 1129 Define this variable to stop the system in case of a 1130 fatal error, so that you have to reset it manually. 1131 This is probably NOT a good idea for an embedded 1132 system where you want to system to reboot 1133 automatically as fast as possible, but it may be 1134 useful during development since you can try to debug 1135 the conditions that lead to the situation. 1136 1137 CONFIG_NET_RETRY_COUNT 1138 1139 This variable defines the number of retries for 1140 network operations like ARP, RARP, TFTP, or BOOTP 1141 before giving up the operation. If not defined, a 1142 default value of 5 is used. 1143 1144- Command Interpreter: 1145 CFG_HUSH_PARSER 1146 1147 Define this variable to enable the "hush" shell (from 1148 Busybox) as command line interpreter, thus enabling 1149 powerful command line syntax like 1150 if...then...else...fi conditionals or `&&' and '||' 1151 constructs ("shell scripts"). 1152 1153 If undefined, you get the old, much simpler behaviour 1154 with a somewhat smaller memory footprint. 1155 1156 1157 CFG_PROMPT_HUSH_PS2 1158 1159 This defines the secondary prompt string, which is 1160 printed when the command interpreter needs more input 1161 to complete a command. Usually "> ". 1162 1163 Note: 1164 1165 In the current implementation, the local variables 1166 space and global environment variables space are 1167 separated. Local variables are those you define by 1168 simply typing like `name=value'. To access a local 1169 variable later on, you have write `$name' or 1170 `${name}'; variable directly by typing say `$name' at 1171 the command prompt. 1172 1173 Global environment variables are those you use 1174 setenv/printenv to work with. To run a command stored 1175 in such a variable, you need to use the run command, 1176 and you must not use the '$' sign to access them. 1177 1178 To store commands and special characters in a 1179 variable, please use double quotation marks 1180 surrounding the whole text of the variable, instead 1181 of the backslashes before semicolons and special 1182 symbols. 1183 1184- Default Environment 1185 CONFIG_EXTRA_ENV_SETTINGS 1186 1187 Define this to contain any number of null terminated 1188 strings (variable = value pairs) that will be part of 1189 the default enviroment compiled into the boot image. 1190 1191 For example, place something like this in your 1192 board's config file: 1193 1194 #define CONFIG_EXTRA_ENV_SETTINGS \ 1195 "myvar1=value1\0" \ 1196 "myvar2=value2\0" 1197 1198 Warning: This method is based on knowledge about the 1199 internal format how the environment is stored by the 1200 U-Boot code. This is NOT an official, exported 1201 interface! Although it is unlikely that this format 1202 will change soon, but there is no guarantee either. 1203 You better know what you are doing here. 1204 1205 Note: overly (ab)use of the default environment is 1206 discouraged. Make sure to check other ways to preset 1207 the environment like the autoscript function or the 1208 boot command first. 1209 1210- Show boot progress 1211 CONFIG_SHOW_BOOT_PROGRESS 1212 1213 Defining this option allows to add some board- 1214 specific code (calling a user-provided function 1215 "show_boot_progress(int)") that enables you to show 1216 the system's boot progress on some display (for 1217 example, some LED's) on your board. At the moment, 1218 the following checkpoints are implemented: 1219 1220 Arg Where When 1221 1 common/cmd_bootm.c before attempting to boot an image 1222 -1 common/cmd_bootm.c Image header has bad magic number 1223 2 common/cmd_bootm.c Image header has correct magic number 1224 -2 common/cmd_bootm.c Image header has bad checksum 1225 3 common/cmd_bootm.c Image header has correct checksum 1226 -3 common/cmd_bootm.c Image data has bad checksum 1227 4 common/cmd_bootm.c Image data has correct checksum 1228 -4 common/cmd_bootm.c Image is for unsupported architecture 1229 5 common/cmd_bootm.c Architecture check OK 1230 -5 common/cmd_bootm.c Wrong Image Type (not kernel, multi, standalone) 1231 6 common/cmd_bootm.c Image Type check OK 1232 -6 common/cmd_bootm.c gunzip uncompression error 1233 -7 common/cmd_bootm.c Unimplemented compression type 1234 7 common/cmd_bootm.c Uncompression OK 1235 -8 common/cmd_bootm.c Wrong Image Type (not kernel, multi, standalone) 1236 8 common/cmd_bootm.c Image Type check OK 1237 -9 common/cmd_bootm.c Unsupported OS (not Linux, BSD, VxWorks, QNX) 1238 9 common/cmd_bootm.c Start initial ramdisk verification 1239 -10 common/cmd_bootm.c Ramdisk header has bad magic number 1240 -11 common/cmd_bootm.c Ramdisk header has bad checksum 1241 10 common/cmd_bootm.c Ramdisk header is OK 1242 -12 common/cmd_bootm.c Ramdisk data has bad checksum 1243 11 common/cmd_bootm.c Ramdisk data has correct checksum 1244 12 common/cmd_bootm.c Ramdisk verification complete, start loading 1245 -13 common/cmd_bootm.c Wrong Image Type (not PPC Linux Ramdisk) 1246 13 common/cmd_bootm.c Start multifile image verification 1247 14 common/cmd_bootm.c No initial ramdisk, no multifile, continue. 1248 15 common/cmd_bootm.c All preparation done, transferring control to OS 1249 1250 -1 common/cmd_doc.c Bad usage of "doc" command 1251 -1 common/cmd_doc.c No boot device 1252 -1 common/cmd_doc.c Unknown Chip ID on boot device 1253 -1 common/cmd_doc.c Read Error on boot device 1254 -1 common/cmd_doc.c Image header has bad magic number 1255 1256 -1 common/cmd_ide.c Bad usage of "ide" command 1257 -1 common/cmd_ide.c No boot device 1258 -1 common/cmd_ide.c Unknown boot device 1259 -1 common/cmd_ide.c Unknown partition table 1260 -1 common/cmd_ide.c Invalid partition type 1261 -1 common/cmd_ide.c Read Error on boot device 1262 -1 common/cmd_ide.c Image header has bad magic number 1263 1264 -1 common/cmd_nvedit.c Environment not changable, but has bad CRC 1265 1266 1267Modem Support: 1268-------------- 1269 1270[so far only for SMDK2400 and TRAB boards] 1271 1272- Modem support endable: 1273 CONFIG_MODEM_SUPPORT 1274 1275- RTS/CTS Flow control enable: 1276 CONFIG_HWFLOW 1277 1278- Modem debug support: 1279 CONFIG_MODEM_SUPPORT_DEBUG 1280 1281 Enables debugging stuff (char screen[1024], dbg()) 1282 for modem support. Useful only with BDI2000. 1283 1284- General: 1285 1286 In the target system modem support is enabled when a 1287 specific key (key combination) is pressed during 1288 power-on. Otherwise U-Boot will boot normally 1289 (autoboot). The key_pressed() fuction is called from 1290 board_init(). Currently key_pressed() is a dummy 1291 function, returning 1 and thus enabling modem 1292 initialization. 1293 1294 If there are no modem init strings in the 1295 environment, U-Boot proceed to autoboot; the 1296 previous output (banner, info printfs) will be 1297 supressed, though. 1298 1299 See also: doc/README.Modem 1300 1301 1302 1303 1304Configuration Settings: 1305----------------------- 1306 1307- CFG_LONGHELP: Defined when you want long help messages included; 1308 undefine this when you're short of memory. 1309 1310- CFG_PROMPT: This is what U-Boot prints on the console to 1311 prompt for user input. 1312 1313- CFG_CBSIZE: Buffer size for input from the Console 1314 1315- CFG_PBSIZE: Buffer size for Console output 1316 1317- CFG_MAXARGS: max. Number of arguments accepted for monitor commands 1318 1319- CFG_BARGSIZE: Buffer size for Boot Arguments which are passed to 1320 the application (usually a Linux kernel) when it is 1321 booted 1322 1323- CFG_BAUDRATE_TABLE: 1324 List of legal baudrate settings for this board. 1325 1326- CFG_CONSOLE_INFO_QUIET 1327 Suppress display of console information at boot. 1328 1329- CFG_CONSOLE_IS_IN_ENV 1330 If the board specific function 1331 extern int overwrite_console (void); 1332 returns 1, the stdin, stderr and stdout are switched to the 1333 serial port, else the settings in the environment are used. 1334 1335- CFG_CONSOLE_OVERWRITE_ROUTINE 1336 Enable the call to overwrite_console(). 1337 1338- CFG_CONSOLE_ENV_OVERWRITE 1339 Enable overwrite of previous console environment settings. 1340 1341- CFG_MEMTEST_START, CFG_MEMTEST_END: 1342 Begin and End addresses of the area used by the 1343 simple memory test. 1344 1345- CFG_ALT_MEMTEST: 1346 Enable an alternate, more extensive memory test. 1347 1348- CFG_TFTP_LOADADDR: 1349 Default load address for network file downloads 1350 1351- CFG_LOADS_BAUD_CHANGE: 1352 Enable temporary baudrate change while serial download 1353 1354- CFG_SDRAM_BASE: 1355 Physical start address of SDRAM. _Must_ be 0 here. 1356 1357- CFG_MBIO_BASE: 1358 Physical start address of Motherboard I/O (if using a 1359 Cogent motherboard) 1360 1361- CFG_FLASH_BASE: 1362 Physical start address of Flash memory. 1363 1364- CFG_MONITOR_BASE: 1365 Physical start address of boot monitor code (set by 1366 make config files to be same as the text base address 1367 (TEXT_BASE) used when linking) - same as 1368 CFG_FLASH_BASE when booting from flash. 1369 1370- CFG_MONITOR_LEN: 1371 Size of memory reserved for monitor code 1372 1373- CFG_MALLOC_LEN: 1374 Size of DRAM reserved for malloc() use. 1375 1376- CFG_BOOTMAPSZ: 1377 Maximum size of memory mapped by the startup code of 1378 the Linux kernel; all data that must be processed by 1379 the Linux kernel (bd_info, boot arguments, eventually 1380 initrd image) must be put below this limit. 1381 1382- CFG_MAX_FLASH_BANKS: 1383 Max number of Flash memory banks 1384 1385- CFG_MAX_FLASH_SECT: 1386 Max number of sectors on a Flash chip 1387 1388- CFG_FLASH_ERASE_TOUT: 1389 Timeout for Flash erase operations (in ms) 1390 1391- CFG_FLASH_WRITE_TOUT: 1392 Timeout for Flash write operations (in ms) 1393 1394- CFG_DIRECT_FLASH_TFTP: 1395 1396 Enable TFTP transfers directly to flash memory; 1397 without this option such a download has to be 1398 performed in two steps: (1) download to RAM, and (2) 1399 copy from RAM to flash. 1400 1401 The two-step approach is usually more reliable, since 1402 you can check if the download worked before you erase 1403 the flash, but in some situations (when sytem RAM is 1404 too limited to allow for a tempory copy of the 1405 downloaded image) this option may be very useful. 1406 1407- CFG_FLASH_CFI: 1408 Define if the flash driver uses extra elements in the 1409 common flash structure for storing flash geometry 1410 1411The following definitions that deal with the placement and management 1412of environment data (variable area); in general, we support the 1413following configurations: 1414 1415- CFG_ENV_IS_IN_FLASH: 1416 1417 Define this if the environment is in flash memory. 1418 1419 a) The environment occupies one whole flash sector, which is 1420 "embedded" in the text segment with the U-Boot code. This 1421 happens usually with "bottom boot sector" or "top boot 1422 sector" type flash chips, which have several smaller 1423 sectors at the start or the end. For instance, such a 1424 layout can have sector sizes of 8, 2x4, 16, Nx32 kB. In 1425 such a case you would place the environment in one of the 1426 4 kB sectors - with U-Boot code before and after it. With 1427 "top boot sector" type flash chips, you would put the 1428 environment in one of the last sectors, leaving a gap 1429 between U-Boot and the environment. 1430 1431 - CFG_ENV_OFFSET: 1432 1433 Offset of environment data (variable area) to the 1434 beginning of flash memory; for instance, with bottom boot 1435 type flash chips the second sector can be used: the offset 1436 for this sector is given here. 1437 1438 CFG_ENV_OFFSET is used relative to CFG_FLASH_BASE. 1439 1440 - CFG_ENV_ADDR: 1441 1442 This is just another way to specify the start address of 1443 the flash sector containing the environment (instead of 1444 CFG_ENV_OFFSET). 1445 1446 - CFG_ENV_SECT_SIZE: 1447 1448 Size of the sector containing the environment. 1449 1450 1451 b) Sometimes flash chips have few, equal sized, BIG sectors. 1452 In such a case you don't want to spend a whole sector for 1453 the environment. 1454 1455 - CFG_ENV_SIZE: 1456 1457 If you use this in combination with CFG_ENV_IS_IN_FLASH 1458 and CFG_ENV_SECT_SIZE, you can specify to use only a part 1459 of this flash sector for the environment. This saves 1460 memory for the RAM copy of the environment. 1461 1462 It may also save flash memory if you decide to use this 1463 when your environment is "embedded" within U-Boot code, 1464 since then the remainder of the flash sector could be used 1465 for U-Boot code. It should be pointed out that this is 1466 STRONGLY DISCOURAGED from a robustness point of view: 1467 updating the environment in flash makes it always 1468 necessary to erase the WHOLE sector. If something goes 1469 wrong before the contents has been restored from a copy in 1470 RAM, your target system will be dead. 1471 1472 - CFG_ENV_ADDR_REDUND 1473 CFG_ENV_SIZE_REDUND 1474 1475 These settings describe a second storage area used to hold 1476 a redundand copy of the environment data, so that there is 1477 a valid backup copy in case there is a power failure during 1478 a "saveenv" operation. 1479 1480BE CAREFUL! Any changes to the flash layout, and some changes to the 1481source code will make it necessary to adapt <board>/u-boot.lds* 1482accordingly! 1483 1484 1485- CFG_ENV_IS_IN_NVRAM: 1486 1487 Define this if you have some non-volatile memory device 1488 (NVRAM, battery buffered SRAM) which you want to use for the 1489 environment. 1490 1491 - CFG_ENV_ADDR: 1492 - CFG_ENV_SIZE: 1493 1494 These two #defines are used to determin the memory area you 1495 want to use for environment. It is assumed that this memory 1496 can just be read and written to, without any special 1497 provision. 1498 1499BE CAREFUL! The first access to the environment happens quite early 1500in U-Boot initalization (when we try to get the setting of for the 1501console baudrate). You *MUST* have mappend your NVRAM area then, or 1502U-Boot will hang. 1503 1504Please note that even with NVRAM we still use a copy of the 1505environment in RAM: we could work on NVRAM directly, but we want to 1506keep settings there always unmodified except somebody uses "saveenv" 1507to save the current settings. 1508 1509 1510- CFG_ENV_IS_IN_EEPROM: 1511 1512 Use this if you have an EEPROM or similar serial access 1513 device and a driver for it. 1514 1515 - CFG_ENV_OFFSET: 1516 - CFG_ENV_SIZE: 1517 1518 These two #defines specify the offset and size of the 1519 environment area within the total memory of your EEPROM. 1520 1521 - CFG_I2C_EEPROM_ADDR: 1522 If defined, specified the chip address of the EEPROM device. 1523 The default address is zero. 1524 1525 - CFG_EEPROM_PAGE_WRITE_BITS: 1526 If defined, the number of bits used to address bytes in a 1527 single page in the EEPROM device. A 64 byte page, for example 1528 would require six bits. 1529 1530 - CFG_EEPROM_PAGE_WRITE_DELAY_MS: 1531 If defined, the number of milliseconds to delay between 1532 page writes. The default is zero milliseconds. 1533 1534 - CFG_I2C_EEPROM_ADDR_LEN: 1535 The length in bytes of the EEPROM memory array address. Note 1536 that this is NOT the chip address length! 1537 1538 - CFG_EEPROM_SIZE: 1539 The size in bytes of the EEPROM device. 1540 1541 1542- CFG_SPI_INIT_OFFSET 1543 1544 Defines offset to the initial SPI buffer area in DPRAM. The 1545 area is used at an early stage (ROM part) if the environment 1546 is configured to reside in the SPI EEPROM: We need a 520 byte 1547 scratch DPRAM area. It is used between the two initialization 1548 calls (spi_init_f() and spi_init_r()). A value of 0xB00 seems 1549 to be a good choice since it makes it far enough from the 1550 start of the data area as well as from the stack pointer. 1551 1552Please note that the environment is read-only as long as the monitor 1553has been relocated to RAM and a RAM copy of the environment has been 1554created; also, when using EEPROM you will have to use getenv_r() 1555until then to read environment variables. 1556 1557The environment is protected by a CRC32 checksum. Before the monitor 1558is relocated into RAM, as a result of a bad CRC you will be working 1559with the compiled-in default environment - *silently*!!! [This is 1560necessary, because the first environment variable we need is the 1561"baudrate" setting for the console - if we have a bad CRC, we don't 1562have any device yet where we could complain.] 1563 1564Note: once the monitor has been relocated, then it will complain if 1565the default environment is used; a new CRC is computed as soon as you 1566use the "saveenv" command to store a valid environment. 1567 1568 1569Low Level (hardware related) configuration options: 1570--------------------------------------------------- 1571 1572- CFG_CACHELINE_SIZE: 1573 Cache Line Size of the CPU. 1574 1575- CFG_DEFAULT_IMMR: 1576 Default address of the IMMR after system reset. 1577 Needed on some 8260 systems (MPC8260ADS and RPXsuper) 1578 to be able to adjust the position of the IMMR 1579 register after a reset. 1580 1581- Floppy Disk Support: 1582 CFG_FDC_DRIVE_NUMBER 1583 1584 the default drive number (default value 0) 1585 1586 CFG_ISA_IO_STRIDE 1587 1588 defines the spacing between fdc chipset registers 1589 (default value 1) 1590 1591 CFG_ISA_IO_OFFSET 1592 1593 defines the offset of register from address. It 1594 depends on which part of the data bus is connected to 1595 the fdc chipset. (default value 0) 1596 1597 If CFG_ISA_IO_STRIDE CFG_ISA_IO_OFFSET and 1598 CFG_FDC_DRIVE_NUMBER are undefined, they take their 1599 default value. 1600 1601 if CFG_FDC_HW_INIT is defined, then the function 1602 fdc_hw_init() is called at the beginning of the FDC 1603 setup. fdc_hw_init() must be provided by the board 1604 source code. It is used to make hardware dependant 1605 initializations. 1606 1607- CFG_IMMR: Physical address of the Internal Memory Mapped 1608 Register; DO NOT CHANGE! (11-4) 1609 [MPC8xx systems only] 1610 1611- CFG_INIT_RAM_ADDR: 1612 1613 Start address of memory area tha can be used for 1614 initial data and stack; please note that this must be 1615 writable memory that is working WITHOUT special 1616 initialization, i. e. you CANNOT use normal RAM which 1617 will become available only after programming the 1618 memory controller and running certain initialization 1619 sequences. 1620 1621 U-Boot uses the following memory types: 1622 - MPC8xx and MPC8260: IMMR (internal memory of the CPU) 1623 - MPC824X: data cache 1624 - PPC4xx: data cache 1625 1626- CFG_GBL_DATA_OFFSET: 1627 1628 Offset of the initial data structure in the memory 1629 area defined by CFG_INIT_RAM_ADDR. Usually 1630 CFG_GBL_DATA_OFFSET is chosen such that the initial 1631 data is located at the end of the available space 1632 (sometimes written as (CFG_INIT_RAM_END - 1633 CFG_INIT_DATA_SIZE), and the initial stack is just 1634 below that area (growing from (CFG_INIT_RAM_ADDR + 1635 CFG_GBL_DATA_OFFSET) downward. 1636 1637 Note: 1638 On the MPC824X (or other systems that use the data 1639 cache for initial memory) the address chosen for 1640 CFG_INIT_RAM_ADDR is basically arbitrary - it must 1641 point to an otherwise UNUSED address space between 1642 the top of RAM and the start of the PCI space. 1643 1644- CFG_SIUMCR: SIU Module Configuration (11-6) 1645 1646- CFG_SYPCR: System Protection Control (11-9) 1647 1648- CFG_TBSCR: Time Base Status and Control (11-26) 1649 1650- CFG_PISCR: Periodic Interrupt Status and Control (11-31) 1651 1652- CFG_PLPRCR: PLL, Low-Power, and Reset Control Register (15-30) 1653 1654- CFG_SCCR: System Clock and reset Control Register (15-27) 1655 1656- CFG_OR_TIMING_SDRAM: 1657 SDRAM timing 1658 1659- CFG_MAMR_PTA: 1660 periodic timer for refresh 1661 1662- CFG_DER: Debug Event Register (37-47) 1663 1664- FLASH_BASE0_PRELIM, FLASH_BASE1_PRELIM, CFG_REMAP_OR_AM, 1665 CFG_PRELIM_OR_AM, CFG_OR_TIMING_FLASH, CFG_OR0_REMAP, 1666 CFG_OR0_PRELIM, CFG_BR0_PRELIM, CFG_OR1_REMAP, CFG_OR1_PRELIM, 1667 CFG_BR1_PRELIM: 1668 Memory Controller Definitions: BR0/1 and OR0/1 (FLASH) 1669 1670- SDRAM_BASE2_PRELIM, SDRAM_BASE3_PRELIM, SDRAM_MAX_SIZE, 1671 CFG_OR_TIMING_SDRAM, CFG_OR2_PRELIM, CFG_BR2_PRELIM, 1672 CFG_OR3_PRELIM, CFG_BR3_PRELIM: 1673 Memory Controller Definitions: BR2/3 and OR2/3 (SDRAM) 1674 1675- CFG_MAMR_PTA, CFG_MPTPR_2BK_4K, CFG_MPTPR_1BK_4K, CFG_MPTPR_2BK_8K, 1676 CFG_MPTPR_1BK_8K, CFG_MAMR_8COL, CFG_MAMR_9COL: 1677 Machine Mode Register and Memory Periodic Timer 1678 Prescaler definitions (SDRAM timing) 1679 1680- CFG_I2C_UCODE_PATCH, CFG_I2C_DPMEM_OFFSET [0x1FC0]: 1681 enable I2C microcode relocation patch (MPC8xx); 1682 define relocation offset in DPRAM [DSP2] 1683 1684- CFG_SPI_UCODE_PATCH, CFG_SPI_DPMEM_OFFSET [0x1FC0]: 1685 enable SPI microcode relocation patch (MPC8xx); 1686 define relocation offset in DPRAM [SCC4] 1687 1688- CFG_USE_OSCCLK: 1689 Use OSCM clock mode on MBX8xx board. Be careful, 1690 wrong setting might damage your board. Read 1691 doc/README.MBX before setting this variable! 1692 1693- CFG_CPM_POST_WORD_ADDR: (MPC8xx, MPC8260 only) 1694 Offset of the bootmode word in DPRAM used by post 1695 (Power On Self Tests). This definition overrides 1696 #define'd default value in commproc.h resp. 1697 cpm_8260.h. 1698 1699Building the Software: 1700====================== 1701 1702Building U-Boot has been tested in native PPC environments (on a 1703PowerBook G3 running LinuxPPC 2000) and in cross environments 1704(running RedHat 6.x and 7.x Linux on x86, Solaris 2.6 on a SPARC, and 1705NetBSD 1.5 on x86). 1706 1707If you are not using a native PPC environment, it is assumed that you 1708have the GNU cross compiling tools available in your path and named 1709with a prefix of "powerpc-linux-". If this is not the case, (e.g. if 1710you are using Monta Vista's Hard Hat Linux CDK 1.2) you must change 1711the definition of CROSS_COMPILE in Makefile. For HHL on a 4xx CPU, 1712change it to: 1713 1714 CROSS_COMPILE = ppc_4xx- 1715 1716 1717U-Boot is intended to be simple to build. After installing the 1718sources you must configure U-Boot for one specific board type. This 1719is done by typing: 1720 1721 make NAME_config 1722 1723where "NAME_config" is the name of one of the existing 1724configurations; the following names are supported: 1725 1726 ADCIOP_config GTH_config TQM850L_config 1727 ADS860_config IP860_config TQM855L_config 1728 AR405_config IVML24_config TQM860L_config 1729 CANBT_config IVMS8_config WALNUT405_config 1730 CPCI405_config LANTEC_config cogent_common_config 1731 CPCIISER4_config MBX_config cogent_mpc8260_config 1732 CU824_config MBX860T_config cogent_mpc8xx_config 1733 ESTEEM192E_config RPXlite_config hermes_config 1734 ETX094_config RPXsuper_config hymod_config 1735 FADS823_config SM850_config lwmon_config 1736 FADS850SAR_config SPD823TS_config pcu_e_config 1737 FADS860T_config SXNI855T_config rsdproto_config 1738 FPS850L_config Sandpoint8240_config sbc8260_config 1739 GENIETV_config TQM823L_config PIP405_config 1740 GEN860T_config EBONY_config FPS860L_config 1741 ELPT860_config cmi_mpc5xx_config 1742 1743Note: for some board special configuration names may exist; check if 1744 additional information is available from the board vendor; for 1745 instance, the TQM8xxL systems run normally at 50 MHz and use a 1746 SCC for 10baseT ethernet; there are also systems with 80 MHz 1747 CPU clock, and an optional Fast Ethernet module is available 1748 for CPU's with FEC. You can select such additional "features" 1749 when chosing the configuration, i. e. 1750 1751 make TQM860L_config 1752 - will configure for a plain TQM860L, i. e. 50MHz, no FEC 1753 1754 make TQM860L_FEC_config 1755 - will configure for a TQM860L at 50MHz with FEC for ethernet 1756 1757 make TQM860L_80MHz_config 1758 - will configure for a TQM860L at 80 MHz, with normal 10baseT 1759 interface 1760 1761 make TQM860L_FEC_80MHz_config 1762 - will configure for a TQM860L at 80 MHz with FEC for ethernet 1763 1764 make TQM823L_LCD_config 1765 - will configure for a TQM823L with U-Boot console on LCD 1766 1767 make TQM823L_LCD_80MHz_config 1768 - will configure for a TQM823L at 80 MHz with U-Boot console on LCD 1769 1770 etc. 1771 1772 1773 1774Finally, type "make all", and you should get some working U-Boot 1775images ready for downlod to / installation on your system: 1776 1777- "u-boot.bin" is a raw binary image 1778- "u-boot" is an image in ELF binary format 1779- "u-boot.srec" is in Motorola S-Record format 1780 1781 1782Please be aware that the Makefiles assume you are using GNU make, so 1783for instance on NetBSD you might need to use "gmake" instead of 1784native "make". 1785 1786 1787If the system board that you have is not listed, then you will need 1788to port U-Boot to your hardware platform. To do this, follow these 1789steps: 1790 17911. Add a new configuration option for your board to the toplevel 1792 "Makefile" and to the "MAKEALL" script, using the existing 1793 entries as examples. Note that here and at many other places 1794 boards and other names are listed alphabetically sorted. Please 1795 keep this order. 17962. Create a new directory to hold your board specific code. Add any 1797 files you need. In your board directory, you will need at least 1798 the "Makefile", a "<board>.c", "flash.c" and "u-boot.lds". 17993. Create a new configuration file "include/configs/<board>.h" for 1800 your board 18013. If you're porting U-Boot to a new CPU, then also create a new 1802 directory to hold your CPU specific code. Add any files you need. 18034. Run "make <board>_config" with your new name. 18045. Type "make", and you should get a working "u-boot.srec" file 1805 to be installed on your target system. 18066. Debug and solve any problems that might arise. 1807 [Of course, this last step is much harder than it sounds.] 1808 1809 1810Testing of U-Boot Modifications, Ports to New Hardware, etc.: 1811============================================================== 1812 1813If you have modified U-Boot sources (for instance added a new board 1814or support for new devices, a new CPU, etc.) you are expected to 1815provide feedback to the other developers. The feedback normally takes 1816the form of a "patch", i. e. a context diff against a certain (latest 1817official or latest in CVS) version of U-Boot sources. 1818 1819But before you submit such a patch, please verify that your modifi- 1820cation did not break existing code. At least make sure that *ALL* of 1821the supported boards compile WITHOUT ANY compiler warnings. To do so, 1822just run the "MAKEALL" script, which will configure and build U-Boot 1823for ALL supported system. Be warned, this will take a while. You can 1824select which (cross) compiler to use py passing a `CROSS_COMPILE' 1825environment variable to the script, i. e. to use the cross tools from 1826MontaVista's Hard Hat Linux you can type 1827 1828 CROSS_COMPILE=ppc_8xx- MAKEALL 1829 1830or to build on a native PowerPC system you can type 1831 1832 CROSS_COMPILE=' ' MAKEALL 1833 1834See also "U-Boot Porting Guide" below. 1835 1836 1837 1838Monitor Commands - Overview: 1839============================ 1840 1841go - start application at address 'addr' 1842run - run commands in an environment variable 1843bootm - boot application image from memory 1844bootp - boot image via network using BootP/TFTP protocol 1845tftpboot- boot image via network using TFTP protocol 1846 and env variables "ipaddr" and "serverip" 1847 (and eventually "gatewayip") 1848rarpboot- boot image via network using RARP/TFTP protocol 1849diskboot- boot from IDE devicebootd - boot default, i.e., run 'bootcmd' 1850loads - load S-Record file over serial line 1851loadb - load binary file over serial line (kermit mode) 1852md - memory display 1853mm - memory modify (auto-incrementing) 1854nm - memory modify (constant address) 1855mw - memory write (fill) 1856cp - memory copy 1857cmp - memory compare 1858crc32 - checksum calculation 1859imd - i2c memory display 1860imm - i2c memory modify (auto-incrementing) 1861inm - i2c memory modify (constant address) 1862imw - i2c memory write (fill) 1863icrc32 - i2c checksum calculation 1864iprobe - probe to discover valid I2C chip addresses 1865iloop - infinite loop on address range 1866isdram - print SDRAM configuration information 1867sspi - SPI utility commands 1868base - print or set address offset 1869printenv- print environment variables 1870setenv - set environment variables 1871saveenv - save environment variables to persistent storage 1872protect - enable or disable FLASH write protection 1873erase - erase FLASH memory 1874flinfo - print FLASH memory information 1875bdinfo - print Board Info structure 1876iminfo - print header information for application image 1877coninfo - print console devices and informations 1878ide - IDE sub-system 1879loop - infinite loop on address range 1880mtest - simple RAM test 1881icache - enable or disable instruction cache 1882dcache - enable or disable data cache 1883reset - Perform RESET of the CPU 1884echo - echo args to console 1885version - print monitor version 1886help - print online help 1887? - alias for 'help' 1888 1889 1890Monitor Commands - Detailed Description: 1891======================================== 1892 1893TODO. 1894 1895For now: just type "help <command>". 1896 1897 1898Environment Variables: 1899====================== 1900 1901U-Boot supports user configuration using Environment Variables which 1902can be made persistent by saving to Flash memory. 1903 1904Environment Variables are set using "setenv", printed using 1905"printenv", and saved to Flash using "saveenv". Using "setenv" 1906without a value can be used to delete a variable from the 1907environment. As long as you don't save the environment you are 1908working with an in-memory copy. In case the Flash area containing the 1909environment is erased by accident, a default environment is provided. 1910 1911Some configuration options can be set using Environment Variables: 1912 1913 baudrate - see CONFIG_BAUDRATE 1914 1915 bootdelay - see CONFIG_BOOTDELAY 1916 1917 bootcmd - see CONFIG_BOOTCOMMAND 1918 1919 bootargs - Boot arguments when booting an RTOS image 1920 1921 bootfile - Name of the image to load with TFTP 1922 1923 autoload - if set to "no" (any string beginning with 'n'), 1924 "bootp" will just load perform a lookup of the 1925 configuration from the BOOTP server, but not try to 1926 load any image using TFTP 1927 1928 autostart - if set to "yes", an image loaded using the "bootp", 1929 "rarpboot", "tftpboot" or "diskboot" commands will 1930 be automatically started (by internally calling 1931 "bootm") 1932 1933 If set to "no", a standalone image passed to the 1934 "bootm" command will be copied to the load address 1935 (and eventually uncompressed), but NOT be started. 1936 This can be used to load and uncompress arbitrary 1937 data. 1938 1939 initrd_high - restrict positioning of initrd images: 1940 If this variable is not set, initrd images will be 1941 copied to the highest possible address in RAM; this 1942 is usually what you want since it allows for 1943 maximum initrd size. If for some reason you want to 1944 make sure that the initrd image is loaded below the 1945 CFG_BOOTMAPSZ limit, you can set this environment 1946 variable to a value of "no" or "off" or "0". 1947 Alternatively, you can set it to a maximum upper 1948 address to use (U-Boot will still check that it 1949 does not overwrite the U-Boot stack and data). 1950 1951 For instance, when you have a system with 16 MB 1952 RAM, and want to reseve 4 MB from use by Linux, 1953 you can do this by adding "mem=12M" to the value of 1954 the "bootargs" variable. However, now you must make 1955 sure, that the initrd image is placed in the first 1956 12 MB as well - this can be done with 1957 1958 setenv initrd_high 00c00000 1959 1960 ipaddr - IP address; needed for tftpboot command 1961 1962 loadaddr - Default load address for commands like "bootp", 1963 "rarpboot", "tftpboot", "loadb" or "diskboot" 1964 1965 loads_echo - see CONFIG_LOADS_ECHO 1966 1967 serverip - TFTP server IP address; needed for tftpboot command 1968 1969 bootretry - see CONFIG_BOOT_RETRY_TIME 1970 1971 bootdelaykey - see CONFIG_AUTOBOOT_DELAY_STR 1972 1973 bootstopkey - see CONFIG_AUTOBOOT_STOP_STR 1974 1975 1976The following environment variables may be used and automatically 1977updated by the network boot commands ("bootp" and "rarpboot"), 1978depending the information provided by your boot server: 1979 1980 bootfile - see above 1981 dnsip - IP address of your Domain Name Server 1982 gatewayip - IP address of the Gateway (Router) to use 1983 hostname - Target hostname 1984 ipaddr - see above 1985 netmask - Subnet Mask 1986 rootpath - Pathname of the root filesystem on the NFS server 1987 serverip - see above 1988 1989 1990There are two special Environment Variables: 1991 1992 serial# - contains hardware identification information such 1993 as type string and/or serial number 1994 ethaddr - Ethernet address 1995 1996These variables can be set only once (usually during manufacturing of 1997the board). U-Boot refuses to delete or overwrite these variables 1998once they have been set once. 1999 2000 2001Further special Environment Variables: 2002 2003 ver - Contains the U-Boot version string as printed 2004 with the "version" command. This variable is 2005 readonly (see CONFIG_VERSION_VARIABLE). 2006 2007 2008Please note that changes to some configuration parameters may take 2009only effect after the next boot (yes, that's just like Windoze :-). 2010 2011 2012Note for Redundant Ethernet Interfaces: 2013======================================= 2014 2015Some boards come with redundand ethernet interfaces; U-Boot supports 2016such configurations and is capable of automatic selection of a 2017"working" interface when needed. MAC assignemnt works as follows: 2018 2019Network interfaces are numbered eth0, eth1, eth2, ... Corresponding 2020MAC addresses can be stored in the environment as "ethaddr" (=>eth0), 2021"eth1addr" (=>eth1), "eth2addr", ... 2022 2023If the network interface stores some valid MAC address (for instance 2024in SROM), this is used as default address if there is NO correspon- 2025ding setting in the environment; if the corresponding environment 2026variable is set, this overrides the settings in the card; that means: 2027 2028o If the SROM has a valid MAC address, and there is no address in the 2029 environment, the SROM's address is used. 2030 2031o If there is no valid address in the SROM, and a definition in the 2032 environment exists, then the value from the environment variable is 2033 used. 2034 2035o If both the SROM and the environment contain a MAC address, and 2036 both addresses are the same, this MAC address is used. 2037 2038o If both the SROM and the environment contain a MAC address, and the 2039 addresses differ, the value from the environment is used and a 2040 warning is printed. 2041 2042o If neither SROM nor the environment contain a MAC address, an error 2043 is raised. 2044 2045 2046 2047Image Formats: 2048============== 2049 2050The "boot" commands of this monitor operate on "image" files which 2051can be basicly anything, preceeded by a special header; see the 2052definitions in include/image.h for details; basicly, the header 2053defines the following image properties: 2054 2055* Target Operating System (Provisions for OpenBSD, NetBSD, FreeBSD, 2056 4.4BSD, Linux, SVR4, Esix, Solaris, Irix, SCO, Dell, NCR, VxWorks, 2057 LynxOS, pSOS, QNX; 2058 Currently supported: Linux, NetBSD, VxWorks, QNX). 2059* Target CPU Architecture (Provisions for Alpha, ARM, Intel x86, 2060 IA64, MIPS, MIPS, PowerPC, IBM S390, SuperH, Sparc, Sparc 64 Bit; 2061 Currently supported: PowerPC). 2062* Compression Type (Provisions for uncompressed, gzip, bzip2; 2063 Currently supported: uncompressed, gzip). 2064* Load Address 2065* Entry Point 2066* Image Name 2067* Image Timestamp 2068 2069The header is marked by a special Magic Number, and both the header 2070and the data portions of the image are secured against corruption by 2071CRC32 checksums. 2072 2073 2074Linux Support: 2075============== 2076 2077Although U-Boot should support any OS or standalone application 2078easily, Linux has always been in the focus during the design of 2079U-Boot. 2080 2081U-Boot includes many features that so far have been part of some 2082special "boot loader" code within the Linux kernel. Also, any 2083"initrd" images to be used are no longer part of one big Linux image; 2084instead, kernel and "initrd" are separate images. This implementation 2085serves serveral purposes: 2086 2087- the same features can be used for other OS or standalone 2088 applications (for instance: using compressed images to reduce the 2089 Flash memory footprint) 2090 2091- it becomes much easier to port new Linux kernel versions because 2092 lots of low-level, hardware dependend stuff are done by U-Boot 2093 2094- the same Linux kernel image can now be used with different "initrd" 2095 images; of course this also means that different kernel images can 2096 be run with the same "initrd". This makes testing easier (you don't 2097 have to build a new "zImage.initrd" Linux image when you just 2098 change a file in your "initrd"). Also, a field-upgrade of the 2099 software is easier now. 2100 2101 2102Linux HOWTO: 2103============ 2104 2105Porting Linux to U-Boot based systems: 2106--------------------------------------- 2107 2108U-Boot cannot save you from doing all the necessary modifications to 2109configure the Linux device drivers for use with your target hardware 2110(no, we don't intend to provide a full virtual machine interface to 2111Linux :-). 2112 2113But now you can ignore ALL boot loader code (in arch/ppc/mbxboot). 2114 2115Just make sure your machine specific header file (for instance 2116include/asm-ppc/tqm8xx.h) includes the same definition of the Board 2117Information structure as we define in include/u-boot.h, and make 2118sure that your definition of IMAP_ADDR uses the same value as your 2119U-Boot configuration in CFG_IMMR. 2120 2121 2122Configuring the Linux kernel: 2123----------------------------- 2124 2125No specific requirements for U-Boot. Make sure you have some root 2126device (initial ramdisk, NFS) for your target system. 2127 2128 2129Building a Linux Image: 2130----------------------- 2131 2132With U-Boot, "normal" build targets like "zImage" or "bzImage" are 2133not used. If you use recent kernel source, a new build target 2134"uImage" will exist which automatically builds an image usable by 2135U-Boot. Most older kernels also have support for a "pImage" target, 2136which was introduced for our predecessor project PPCBoot and uses a 2137100% compatible format. 2138 2139Example: 2140 2141 make TQM850L_config 2142 make oldconfig 2143 make dep 2144 make uImage 2145 2146The "uImage" build target uses a special tool (in 'tools/mkimage') to 2147encapsulate a compressed Linux kernel image with header information, 2148CRC32 checksum etc. for use with U-Boot. This is what we are doing: 2149 2150* build a standard "vmlinux" kernel image (in ELF binary format): 2151 2152* convert the kernel into a raw binary image: 2153 2154 ${CROSS_COMPILE}-objcopy -O binary \ 2155 -R .note -R .comment \ 2156 -S vmlinux linux.bin 2157 2158* compress the binary image: 2159 2160 gzip -9 linux.bin 2161 2162* package compressed binary image for U-Boot: 2163 2164 mkimage -A ppc -O linux -T kernel -C gzip \ 2165 -a 0 -e 0 -n "Linux Kernel Image" \ 2166 -d linux.bin.gz uImage 2167 2168 2169The "mkimage" tool can also be used to create ramdisk images for use 2170with U-Boot, either separated from the Linux kernel image, or 2171combined into one file. "mkimage" encapsulates the images with a 64 2172byte header containing information about target architecture, 2173operating system, image type, compression method, entry points, time 2174stamp, CRC32 checksums, etc. 2175 2176"mkimage" can be called in two ways: to verify existing images and 2177print the header information, or to build new images. 2178 2179In the first form (with "-l" option) mkimage lists the information 2180contained in the header of an existing U-Boot image; this includes 2181checksum verification: 2182 2183 tools/mkimage -l image 2184 -l ==> list image header information 2185 2186The second form (with "-d" option) is used to build a U-Boot image 2187from a "data file" which is used as image payload: 2188 2189 tools/mkimage -A arch -O os -T type -C comp -a addr -e ep \ 2190 -n name -d data_file image 2191 -A ==> set architecture to 'arch' 2192 -O ==> set operating system to 'os' 2193 -T ==> set image type to 'type' 2194 -C ==> set compression type 'comp' 2195 -a ==> set load address to 'addr' (hex) 2196 -e ==> set entry point to 'ep' (hex) 2197 -n ==> set image name to 'name' 2198 -d ==> use image data from 'datafile' 2199 2200Right now, all Linux kernels use the same load address (0x00000000), 2201but the entry point address depends on the kernel version: 2202 2203- 2.2.x kernels have the entry point at 0x0000000C, 2204- 2.3.x and later kernels have the entry point at 0x00000000. 2205 2206So a typical call to build a U-Boot image would read: 2207 2208 -> tools/mkimage -n '2.4.4 kernel for TQM850L' \ 2209 > -A ppc -O linux -T kernel -C gzip -a 0 -e 0 \ 2210 > -d /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/ppc/coffboot/vmlinux.gz \ 2211 > examples/uImage.TQM850L 2212 Image Name: 2.4.4 kernel for TQM850L 2213 Created: Wed Jul 19 02:34:59 2000 2214 Image Type: PowerPC Linux Kernel Image (gzip compressed) 2215 Data Size: 335725 Bytes = 327.86 kB = 0.32 MB 2216 Load Address: 0x00000000 2217 Entry Point: 0x00000000 2218 2219To verify the contents of the image (or check for corruption): 2220 2221 -> tools/mkimage -l examples/uImage.TQM850L 2222 Image Name: 2.4.4 kernel for TQM850L 2223 Created: Wed Jul 19 02:34:59 2000 2224 Image Type: PowerPC Linux Kernel Image (gzip compressed) 2225 Data Size: 335725 Bytes = 327.86 kB = 0.32 MB 2226 Load Address: 0x00000000 2227 Entry Point: 0x00000000 2228 2229NOTE: for embedded systems where boot time is critical you can trade 2230speed for memory and install an UNCOMPRESSED image instead: this 2231needs more space in Flash, but boots much faster since it does not 2232need to be uncompressed: 2233 2234 -> gunzip /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/ppc/coffboot/vmlinux.gz 2235 -> tools/mkimage -n '2.4.4 kernel for TQM850L' \ 2236 > -A ppc -O linux -T kernel -C none -a 0 -e 0 \ 2237 > -d /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/ppc/coffboot/vmlinux \ 2238 > examples/uImage.TQM850L-uncompressed 2239 Image Name: 2.4.4 kernel for TQM850L 2240 Created: Wed Jul 19 02:34:59 2000 2241 Image Type: PowerPC Linux Kernel Image (uncompressed) 2242 Data Size: 792160 Bytes = 773.59 kB = 0.76 MB 2243 Load Address: 0x00000000 2244 Entry Point: 0x00000000 2245 2246 2247Similar you can build U-Boot images from a 'ramdisk.image.gz' file 2248when your kernel is intended to use an initial ramdisk: 2249 2250 -> tools/mkimage -n 'Simple Ramdisk Image' \ 2251 > -A ppc -O linux -T ramdisk -C gzip \ 2252 > -d /LinuxPPC/images/SIMPLE-ramdisk.image.gz examples/simple-initrd 2253 Image Name: Simple Ramdisk Image 2254 Created: Wed Jan 12 14:01:50 2000 2255 Image Type: PowerPC Linux RAMDisk Image (gzip compressed) 2256 Data Size: 566530 Bytes = 553.25 kB = 0.54 MB 2257 Load Address: 0x00000000 2258 Entry Point: 0x00000000 2259 2260 2261Installing a Linux Image: 2262------------------------- 2263 2264To downloading a U-Boot image over the serial (console) interface, 2265you must convert the image to S-Record format: 2266 2267 objcopy -I binary -O srec examples/image examples/image.srec 2268 2269The 'objcopy' does not understand the information in the U-Boot 2270image header, so the resulting S-Record file will be relative to 2271address 0x00000000. To load it to a given address, you need to 2272specify the target address as 'offset' parameter with the 'loads' 2273command. 2274 2275Example: install the image to address 0x40100000 (which on the 2276TQM8xxL is in the first Flash bank): 2277 2278 => erase 40100000 401FFFFF 2279 2280 .......... done 2281 Erased 8 sectors 2282 2283 => loads 40100000 2284 ## Ready for S-Record download ... 2285 ~>examples/image.srec 2286 1 2 3 4 5 6 7 8 9 10 11 12 13 ... 2287 ... 2288 15989 15990 15991 15992 2289 [file transfer complete] 2290 [connected] 2291 ## Start Addr = 0x00000000 2292 2293 2294You can check the success of the download using the 'iminfo' command; 2295this includes a checksum verification so you can be sure no data 2296corruption happened: 2297 2298 => imi 40100000 2299 2300 ## Checking Image at 40100000 ... 2301 Image Name: 2.2.13 for initrd on TQM850L 2302 Image Type: PowerPC Linux Kernel Image (gzip compressed) 2303 Data Size: 335725 Bytes = 327 kB = 0 MB 2304 Load Address: 00000000 2305 Entry Point: 0000000c 2306 Verifying Checksum ... OK 2307 2308 2309 2310Boot Linux: 2311----------- 2312 2313The "bootm" command is used to boot an application that is stored in 2314memory (RAM or Flash). In case of a Linux kernel image, the contents 2315of the "bootargs" environment variable is passed to the kernel as 2316parameters. You can check and modify this variable using the 2317"printenv" and "setenv" commands: 2318 2319 2320 => printenv bootargs 2321 bootargs=root=/dev/ram 2322 2323 => setenv bootargs root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2 2324 2325 => printenv bootargs 2326 bootargs=root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2 2327 2328 => bootm 40020000 2329 ## Booting Linux kernel at 40020000 ... 2330 Image Name: 2.2.13 for NFS on TQM850L 2331 Image Type: PowerPC Linux Kernel Image (gzip compressed) 2332 Data Size: 381681 Bytes = 372 kB = 0 MB 2333 Load Address: 00000000 2334 Entry Point: 0000000c 2335 Verifying Checksum ... OK 2336 Uncompressing Kernel Image ... OK 2337 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 2338 Boot arguments: root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2 2339 time_init: decrementer frequency = 187500000/60 2340 Calibrating delay loop... 49.77 BogoMIPS 2341 Memory: 15208k available (700k kernel code, 444k data, 32k init) [c0000000,c1000000] 2342 ... 2343 2344If you want to boot a Linux kernel with initial ram disk, you pass 2345the memory addreses of both the kernel and the initrd image (PPBCOOT 2346format!) to the "bootm" command: 2347 2348 => imi 40100000 40200000 2349 2350 ## Checking Image at 40100000 ... 2351 Image Name: 2.2.13 for initrd on TQM850L 2352 Image Type: PowerPC Linux Kernel Image (gzip compressed) 2353 Data Size: 335725 Bytes = 327 kB = 0 MB 2354 Load Address: 00000000 2355 Entry Point: 0000000c 2356 Verifying Checksum ... OK 2357 2358 ## Checking Image at 40200000 ... 2359 Image Name: Simple Ramdisk Image 2360 Image Type: PowerPC Linux RAMDisk Image (gzip compressed) 2361 Data Size: 566530 Bytes = 553 kB = 0 MB 2362 Load Address: 00000000 2363 Entry Point: 00000000 2364 Verifying Checksum ... OK 2365 2366 => bootm 40100000 40200000 2367 ## Booting Linux kernel at 40100000 ... 2368 Image Name: 2.2.13 for initrd on TQM850L 2369 Image Type: PowerPC Linux Kernel Image (gzip compressed) 2370 Data Size: 335725 Bytes = 327 kB = 0 MB 2371 Load Address: 00000000 2372 Entry Point: 0000000c 2373 Verifying Checksum ... OK 2374 Uncompressing Kernel Image ... OK 2375 ## Loading RAMDisk Image at 40200000 ... 2376 Image Name: Simple Ramdisk Image 2377 Image Type: PowerPC Linux RAMDisk Image (gzip compressed) 2378 Data Size: 566530 Bytes = 553 kB = 0 MB 2379 Load Address: 00000000 2380 Entry Point: 00000000 2381 Verifying Checksum ... OK 2382 Loading Ramdisk ... OK 2383 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 2384 Boot arguments: root=/dev/ram 2385 time_init: decrementer frequency = 187500000/60 2386 Calibrating delay loop... 49.77 BogoMIPS 2387 ... 2388 RAMDISK: Compressed image found at block 0 2389 VFS: Mounted root (ext2 filesystem). 2390 2391 bash# 2392 2393More About U-Boot Image Types: 2394------------------------------ 2395 2396U-Boot supports the following image types: 2397 2398 "Standalone Programs" are directly runnable in the environment 2399 provided by U-Boot; it is expected that (if they behave 2400 well) you can continue to work in U-Boot after return from 2401 the Standalone Program. 2402 "OS Kernel Images" are usually images of some Embedded OS which 2403 will take over control completely. Usually these programs 2404 will install their own set of exception handlers, device 2405 drivers, set up the MMU, etc. - this means, that you cannot 2406 expect to re-enter U-Boot except by resetting the CPU. 2407 "RAMDisk Images" are more or less just data blocks, and their 2408 parameters (address, size) are passed to an OS kernel that is 2409 being started. 2410 "Multi-File Images" contain several images, typically an OS 2411 (Linux) kernel image and one or more data images like 2412 RAMDisks. This construct is useful for instance when you want 2413 to boot over the network using BOOTP etc., where the boot 2414 server provides just a single image file, but you want to get 2415 for instance an OS kernel and a RAMDisk image. 2416 2417 "Multi-File Images" start with a list of image sizes, each 2418 image size (in bytes) specified by an "uint32_t" in network 2419 byte order. This list is terminated by an "(uint32_t)0". 2420 Immediately after the terminating 0 follow the images, one by 2421 one, all aligned on "uint32_t" boundaries (size rounded up to 2422 a multiple of 4 bytes). 2423 2424 "Firmware Images" are binary images containing firmware (like 2425 U-Boot or FPGA images) which usually will be programmed to 2426 flash memory. 2427 2428 "Script files" are command sequences that will be executed by 2429 U-Boot's command interpreter; this feature is especially 2430 useful when you configure U-Boot to use a real shell (hush) 2431 as command interpreter. 2432 2433 2434Standalone HOWTO: 2435================= 2436 2437One of the features of U-Boot is that you can dynamically load and 2438run "standalone" applications, which can use some resources of 2439U-Boot like console I/O functions or interrupt services. 2440 2441Two simple examples are included with the sources: 2442 2443"Hello World" Demo: 2444------------------- 2445 2446'examples/hello_world.c' contains a small "Hello World" Demo 2447application; it is automatically compiled when you build U-Boot. 2448It's configured to run at address 0x00040004, so you can play with it 2449like that: 2450 2451 => loads 2452 ## Ready for S-Record download ... 2453 ~>examples/hello_world.srec 2454 1 2 3 4 5 6 7 8 9 10 11 ... 2455 [file transfer complete] 2456 [connected] 2457 ## Start Addr = 0x00040004 2458 2459 => go 40004 Hello World! This is a test. 2460 ## Starting application at 0x00040004 ... 2461 Hello World 2462 argc = 7 2463 argv[0] = "40004" 2464 argv[1] = "Hello" 2465 argv[2] = "World!" 2466 argv[3] = "This" 2467 argv[4] = "is" 2468 argv[5] = "a" 2469 argv[6] = "test." 2470 argv[7] = "<NULL>" 2471 Hit any key to exit ... 2472 2473 ## Application terminated, rc = 0x0 2474 2475Another example, which demonstrates how to register a CPM interrupt 2476handler with the U-Boot code, can be found in 'examples/timer.c'. 2477Here, a CPM timer is set up to generate an interrupt every second. 2478The interrupt service routine is trivial, just printing a '.' 2479character, but this is just a demo program. The application can be 2480controlled by the following keys: 2481 2482 ? - print current values og the CPM Timer registers 2483 b - enable interrupts and start timer 2484 e - stop timer and disable interrupts 2485 q - quit application 2486 2487 => loads 2488 ## Ready for S-Record download ... 2489 ~>examples/timer.srec 2490 1 2 3 4 5 6 7 8 9 10 11 ... 2491 [file transfer complete] 2492 [connected] 2493 ## Start Addr = 0x00040004 2494 2495 => go 40004 2496 ## Starting application at 0x00040004 ... 2497 TIMERS=0xfff00980 2498 Using timer 1 2499 tgcr @ 0xfff00980, tmr @ 0xfff00990, trr @ 0xfff00994, tcr @ 0xfff00998, tcn @ 0xfff0099c, ter @ 0xfff009b0 2500 2501Hit 'b': 2502 [q, b, e, ?] Set interval 1000000 us 2503 Enabling timer 2504Hit '?': 2505 [q, b, e, ?] ........ 2506 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0xef6, ter=0x0 2507Hit '?': 2508 [q, b, e, ?] . 2509 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x2ad4, ter=0x0 2510Hit '?': 2511 [q, b, e, ?] . 2512 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x1efc, ter=0x0 2513Hit '?': 2514 [q, b, e, ?] . 2515 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x169d, ter=0x0 2516Hit 'e': 2517 [q, b, e, ?] ...Stopping timer 2518Hit 'q': 2519 [q, b, e, ?] ## Application terminated, rc = 0x0 2520 2521 2522 2523Minicom warning: 2524================ 2525 2526Over time, many people have reported problems when trying to used the 2527"minicom" terminal emulation program for serial download. I (wd) 2528consider minicom to be broken, and recommend not to use it. Under 2529Unix, I recommend to use CKermit for general purpose use (and 2530especially for kermit binary protocol download ("loadb" command), and 2531use "cu" for S-Record download ("loads" command). 2532 2533NetBSD Notes: 2534============= 2535 2536Starting at version 0.9.2, U-Boot supports NetBSD both as host 2537(build U-Boot) and target system (boots NetBSD/mpc8xx). 2538 2539Building requires a cross environment; it is known to work on 2540NetBSD/i386 with the cross-powerpc-netbsd-1.3 package (you will also 2541need gmake since the Makefiles are not compatible with BSD make). 2542Note that the cross-powerpc package does not install include files; 2543attempting to build U-Boot will fail because <machine/ansi.h> is 2544missing. This file has to be installed and patched manually: 2545 2546 # cd /usr/pkg/cross/powerpc-netbsd/include 2547 # mkdir powerpc 2548 # ln -s powerpc machine 2549 # cp /usr/src/sys/arch/powerpc/include/ansi.h powerpc/ansi.h 2550 # ${EDIT} powerpc/ansi.h ## must remove __va_list, _BSD_VA_LIST 2551 2552Native builds *don't* work due to incompatibilities between native 2553and U-Boot include files. 2554 2555Booting assumes that (the first part of) the image booted is a 2556stage-2 loader which in turn loads and then invokes the kernel 2557proper. Loader sources will eventually appear in the NetBSD source 2558tree (probably in sys/arc/mpc8xx/stand/u-boot_stage2/); in the 2559meantime, send mail to bruno@exet-ag.de and/or wd@denx.de for 2560details. 2561 2562 2563Implementation Internals: 2564========================= 2565 2566The following is not intended to be a complete description of every 2567implementation detail. However, it should help to understand the 2568inner workings of U-Boot and make it easier to port it to custom 2569hardware. 2570 2571 2572Initial Stack, Global Data: 2573--------------------------- 2574 2575The implementation of U-Boot is complicated by the fact that U-Boot 2576starts running out of ROM (flash memory), usually without access to 2577system RAM (because the memory controller is not initialized yet). 2578This means that we don't have writable Data or BSS segments, and BSS 2579is not initialized as zero. To be able to get a C environment working 2580at all, we have to allocate at least a minimal stack. Implementation 2581options for this are defined and restricted by the CPU used: Some CPU 2582models provide on-chip memory (like the IMMR area on MPC8xx and 2583MPC826x processors), on others (parts of) the data cache can be 2584locked as (mis-) used as memory, etc. 2585 2586 Chris Hallinan posted a good summy of these issues to the 2587 u-boot-users mailing list: 2588 2589 Subject: RE: [U-Boot-Users] RE: More On Memory Bank x (nothingness)? 2590 From: "Chris Hallinan" <clh@net1plus.com> 2591 Date: Mon, 10 Feb 2003 16:43:46 -0500 (22:43 MET) 2592 ... 2593 2594 Correct me if I'm wrong, folks, but the way I understand it 2595 is this: Using DCACHE as initial RAM for Stack, etc, does not 2596 require any physical RAM backing up the cache. The cleverness 2597 is that the cache is being used as a temporary supply of 2598 necessary storage before the SDRAM controller is setup. It's 2599 beyond the scope of this list to expain the details, but you 2600 can see how this works by studying the cache architecture and 2601 operation in the architecture and processor-specific manuals. 2602 2603 OCM is On Chip Memory, which I believe the 405GP has 4K. It 2604 is another option for the system designer to use as an 2605 initial stack/ram area prior to SDRAM being available. Either 2606 option should work for you. Using CS 4 should be fine if your 2607 board designers haven't used it for something that would 2608 cause you grief during the initial boot! It is frequently not 2609 used. 2610 2611 CFG_INIT_RAM_ADDR should be somewhere that won't interfere 2612 with your processor/board/system design. The default value 2613 you will find in any recent u-boot distribution in 2614 Walnut405.h should work for you. I'd set it to a value larger 2615 than your SDRAM module. If you have a 64MB SDRAM module, set 2616 it above 400_0000. Just make sure your board has no resources 2617 that are supposed to respond to that address! That code in 2618 start.S has been around a while and should work as is when 2619 you get the config right. 2620 2621 -Chris Hallinan 2622 DS4.COM, Inc. 2623 2624It is essential to remember this, since it has some impact on the C 2625code for the initialization procedures: 2626 2627* Initialized global data (data segment) is read-only. Do not attempt 2628 to write it. 2629 2630* Do not use any unitialized global data (or implicitely initialized 2631 as zero data - BSS segment) at all - this is undefined, initiali- 2632 zation is performed later (when relocationg to RAM). 2633 2634* Stack space is very limited. Avoid big data buffers or things like 2635 that. 2636 2637Having only the stack as writable memory limits means we cannot use 2638normal global data to share information beween the code. But it 2639turned out that the implementation of U-Boot can be greatly 2640simplified by making a global data structure (gd_t) available to all 2641functions. We could pass a pointer to this data as argument to _all_ 2642functions, but this would bloat the code. Instead we use a feature of 2643the GCC compiler (Global Register Variables) to share the data: we 2644place a pointer (gd) to the global data into a register which we 2645reserve for this purpose. 2646 2647When chosing a register for such a purpose we are restricted by the 2648relevant (E)ABI specifications for the current architecture, and by 2649GCC's implementation. 2650 2651For PowerPC, the following registers have specific use: 2652 R1: stack pointer 2653 R2: TOC pointer 2654 R3-R4: parameter passing and return values 2655 R5-R10: parameter passing 2656 R13: small data area pointer 2657 R30: GOT pointer 2658 R31: frame pointer 2659 2660 (U-Boot also uses R14 as internal GOT pointer.) 2661 2662 ==> U-Boot will use R29 to hold a pointer to the global data 2663 2664 Note: on PPC, we could use a static initializer (since the 2665 address of the global data structure is known at compile time), 2666 but it turned out that reserving a register results in somewhat 2667 smaller code - although the code savings are not that big (on 2668 average for all boards 752 bytes for the whole U-Boot image, 2669 624 text + 127 data). 2670 2671On ARM, the following registers are used: 2672 2673 R0: function argument word/integer result 2674 R1-R3: function argument word 2675 R9: GOT pointer 2676 R10: stack limit (used only if stack checking if enabled) 2677 R11: argument (frame) pointer 2678 R12: temporary workspace 2679 R13: stack pointer 2680 R14: link register 2681 R15: program counter 2682 2683 ==> U-Boot will use R8 to hold a pointer to the global data 2684 2685 2686 2687Memory Management: 2688------------------ 2689 2690U-Boot runs in system state and uses physical addresses, i.e. the 2691MMU is not used either for address mapping nor for memory protection. 2692 2693The available memory is mapped to fixed addresses using the memory 2694controller. In this process, a contiguous block is formed for each 2695memory type (Flash, SDRAM, SRAM), even when it consists of several 2696physical memory banks. 2697 2698U-Boot is installed in the first 128 kB of the first Flash bank (on 2699TQM8xxL modules this is the range 0x40000000 ... 0x4001FFFF). After 2700booting and sizing and initializing DRAM, the code relocates itself 2701to the upper end of DRAM. Immediately below the U-Boot code some 2702memory is reserved for use by malloc() [see CFG_MALLOC_LEN 2703configuration setting]. Below that, a structure with global Board 2704Info data is placed, followed by the stack (growing downward). 2705 2706Additionally, some exception handler code is copied to the low 8 kB 2707of DRAM (0x00000000 ... 0x00001FFF). 2708 2709So a typical memory configuration with 16 MB of DRAM could look like 2710this: 2711 2712 0x0000 0000 Exception Vector code 2713 : 2714 0x0000 1FFF 2715 0x0000 2000 Free for Application Use 2716 : 2717 : 2718 2719 : 2720 : 2721 0x00FB FF20 Monitor Stack (Growing downward) 2722 0x00FB FFAC Board Info Data and permanent copy of global data 2723 0x00FC 0000 Malloc Arena 2724 : 2725 0x00FD FFFF 2726 0x00FE 0000 RAM Copy of Monitor Code 2727 ... eventually: LCD or video framebuffer 2728 ... eventually: pRAM (Protected RAM - unchanged by reset) 2729 0x00FF FFFF [End of RAM] 2730 2731 2732System Initialization: 2733---------------------- 2734 2735In the reset configuration, U-Boot starts at the reset entry point 2736(on most PowerPC systens at address 0x00000100). Because of the reset 2737configuration for CS0# this is a mirror of the onboard Flash memory. 2738To be able to re-map memory U-Boot then jumps to it's link address. 2739To be able to implement the initialization code in C, a (small!) 2740initial stack is set up in the internal Dual Ported RAM (in case CPUs 2741which provide such a feature like MPC8xx or MPC8260), or in a locked 2742part of the data cache. After that, U-Boot initializes the CPU core, 2743the caches and the SIU. 2744 2745Next, all (potentially) available memory banks are mapped using a 2746preliminary mapping. For example, we put them on 512 MB boundaries 2747(multiples of 0x20000000: SDRAM on 0x00000000 and 0x20000000, Flash 2748on 0x40000000 and 0x60000000, SRAM on 0x80000000). Then UPM A is 2749programmed for SDRAM access. Using the temporary configuration, a 2750simple memory test is run that determines the size of the SDRAM 2751banks. 2752 2753When there is more than one SDRAM bank, and the banks are of 2754different size, the larger is mapped first. For equal size, the first 2755bank (CS2#) is mapped first. The first mapping is always for address 27560x00000000, with any additional banks following immediately to create 2757contiguous memory starting from 0. 2758 2759Then, the monitor installs itself at the upper end of the SDRAM area 2760and allocates memory for use by malloc() and for the global Board 2761Info data; also, the exception vector code is copied to the low RAM 2762pages, and the final stack is set up. 2763 2764Only after this relocation will you have a "normal" C environment; 2765until that you are restricted in several ways, mostly because you are 2766running from ROM, and because the code will have to be relocated to a 2767new address in RAM. 2768 2769 2770U-Boot Porting Guide: 2771---------------------- 2772 2773[Based on messages by Jerry Van Baren in the U-Boot-Users mailing 2774list, October 2002] 2775 2776 2777int main (int argc, char *argv[]) 2778{ 2779 sighandler_t no_more_time; 2780 2781 signal (SIGALRM, no_more_time); 2782 alarm (PROJECT_DEADLINE - toSec (3 * WEEK)); 2783 2784 if (available_money > available_manpower) { 2785 pay consultant to port U-Boot; 2786 return 0; 2787 } 2788 2789 Download latest U-Boot source; 2790 2791 Subscribe to u-boot-users mailing list; 2792 2793 if (clueless) { 2794 email ("Hi, I am new to U-Boot, how do I get started?"); 2795 } 2796 2797 while (learning) { 2798 Read the README file in the top level directory; 2799 Read http://www.denx.de/re/DPLG.html 2800 Read the source, Luke; 2801 } 2802 2803 if (available_money > toLocalCurrency ($2500)) { 2804 Buy a BDI2000; 2805 } else { 2806 Add a lot of aggravation and time; 2807 } 2808 2809 Create your own board support subdirectory; 2810 2811 Create your own board config file; 2812 2813 while (!running) { 2814 do { 2815 Add / modify source code; 2816 } until (compiles); 2817 Debug; 2818 if (clueless) 2819 email ("Hi, I am having problems..."); 2820 } 2821 Send patch file to Wolfgang; 2822 2823 return 0; 2824} 2825 2826void no_more_time (int sig) 2827{ 2828 hire_a_guru(); 2829} 2830 2831 2832 2833Coding Standards: 2834----------------- 2835 2836All contributions to U-Boot should conform to the Linux kernel 2837coding style; see the file "Documentation/CodingStyle" in your Linux 2838kernel source directory. 2839 2840Please note that U-Boot is implemented in C (and to some small parts 2841in Assembler); no C++ is used, so please do not use C++ style 2842comments (//) in your code. 2843 2844Submissions which do not conform to the standards may be returned 2845with a request to reformat the changes. 2846 2847 2848Submitting Patches: 2849------------------- 2850 2851Since the number of patches for U-Boot is growing, we need to 2852establish some rules. Submissions which do not conform to these rules 2853may be rejected, even when they contain important and valuable stuff. 2854 2855 2856When you send a patch, please include the following information with 2857it: 2858 2859* For bug fixes: a description of the bug and how your patch fixes 2860 this bug. Please try to include a way of demonstrating that the 2861 patch actually fixes something. 2862 2863* For new features: a description of the feature and your 2864 implementation. 2865 2866* A CHANGELOG entry as plaintext (separate from the patch) 2867 2868* For major contributions, your entry to the CREDITS file 2869 2870* When you add support for a new board, don't forget to add this 2871 board to the MAKEALL script, too. 2872 2873* If your patch adds new configuration options, don't forget to 2874 document these in the README file. 2875 2876* The patch itself. If you are accessing the CVS repository use "cvs 2877 update; cvs diff -puRN"; else, use "diff -purN OLD NEW". If your 2878 version of diff does not support these options, then get the latest 2879 version of GNU diff. 2880 2881 We accept patches as plain text, MIME attachments or as uuencoded 2882 gzipped text. 2883 2884Notes: 2885 2886* Before sending the patch, run the MAKEALL script on your patched 2887 source tree and make sure that no errors or warnings are reported 2888 for any of the boards. 2889 2890* Keep your modifications to the necessary minimum: A patch 2891 containing several unrelated changes or arbitrary reformats will be 2892 returned with a request to re-formatting / split it. 2893 2894* If you modify existing code, make sure that your new code does not 2895 add to the memory footprint of the code ;-) Small is beautiful! 2896 When adding new features, these should compile conditionally only 2897 (using #ifdef), and the resulting code with the new feature 2898 disabled must not need more memory than the old code without your 2899 modification. 2900