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- NETWORK Support (other): 699 700 CONFIG_DRIVER_LAN91C96 701 Support for SMSC's LAN91C96 chips. 702 703 CONFIG_LAN91C96_BASE 704 Define this to hold the physical address 705 of the LAN91C96's I/O space 706 707 CONFIG_LAN91C96_USE_32_BIT 708 Define this to enable 32 bit addressing 709 710- USB Support: 711 At the moment only the UHCI host controller is 712 supported (PIP405, MIP405); define 713 CONFIG_USB_UHCI to enable it. 714 define CONFIG_USB_KEYBOARD to enable the USB Keyboard 715 end define CONFIG_USB_STORAGE to enable the USB 716 storage devices. 717 Note: 718 Supported are USB Keyboards and USB Floppy drives 719 (TEAC FD-05PUB). 720 721- Keyboard Support: 722 CONFIG_ISA_KEYBOARD 723 724 Define this to enable standard (PC-Style) keyboard 725 support 726 727 CONFIG_I8042_KBD 728 Standard PC keyboard driver with US (is default) and 729 GERMAN key layout (switch via environment 'keymap=de') support. 730 Export function i8042_kbd_init, i8042_tstc and i8042_getc 731 for cfb_console. Supports cursor blinking. 732 733- Video support: 734 CONFIG_VIDEO 735 736 Define this to enable video support (for output to 737 video). 738 739 CONFIG_VIDEO_CT69000 740 741 Enable Chips & Technologies 69000 Video chip 742 743 CONFIG_VIDEO_SMI_LYNXEM 744 Enable Silicon Motion SMI 712/710/810 Video chip 745 Videomode are selected via environment 'videomode' with 746 standard LiLo mode numbers. 747 Following modes are supported (* is default): 748 749 800x600 1024x768 1280x1024 750 256 (8bit) 303* 305 307 751 65536 (16bit) 314 317 31a 752 16,7 Mill (24bit) 315 318 31b 753 (i.e. setenv videomode 317; saveenv; reset;) 754 755 CONFIG_VIDEO_SED13806 756 Enable Epson SED13806 driver. This driver supports 8bpp 757 and 16bpp modes defined by CONFIG_VIDEO_SED13806_8BPP 758 or CONFIG_VIDEO_SED13806_16BPP 759 760 761- LCD Support: CONFIG_LCD 762 763 Define this to enable LCD support (for output to LCD 764 display); also select one of the supported displays 765 by defining one of these: 766 767 CONFIG_NEC_NL6648AC33: 768 769 NEC NL6648AC33-18. Active, color, single scan. 770 771 CONFIG_NEC_NL6648BC20 772 773 NEC NL6648BC20-08. 6.5", 640x480. 774 Active, color, single scan. 775 776 CONFIG_SHARP_16x9 777 778 Sharp 320x240. Active, color, single scan. 779 It isn't 16x9, and I am not sure what it is. 780 781 CONFIG_SHARP_LQ64D341 782 783 Sharp LQ64D341 display, 640x480. 784 Active, color, single scan. 785 786 CONFIG_HLD1045 787 788 HLD1045 display, 640x480. 789 Active, color, single scan. 790 791 CONFIG_OPTREX_BW 792 793 Optrex CBL50840-2 NF-FW 99 22 M5 794 or 795 Hitachi LMG6912RPFC-00T 796 or 797 Hitachi SP14Q002 798 799 320x240. Black & white. 800 801 Normally display is black on white background; define 802 CFG_WHITE_ON_BLACK to get it inverted. 803 804- Spash Screen Support: CONFIG_SPLASH_SCREEN 805 806 If this option is set, the environment is checked for 807 a variable "splashimage". If found, the usual display 808 of logo, copyright and system information on the LCD 809 is supressed and the BMP image at the address 810 specified in "splashimage" is loaded instead. The 811 console is redirected to the "nulldev", too. This 812 allows for a "silent" boot where a splash screen is 813 loaded very quickly after power-on. 814 815 816- Ethernet address: 817 CONFIG_ETHADDR 818 CONFIG_ETH2ADDR 819 CONFIG_ETH3ADDR 820 821 Define a default value for ethernet address to use 822 for the respective ethernet interface, in case this 823 is not determined automatically. 824 825- IP address: 826 CONFIG_IPADDR 827 828 Define a default value for the IP address to use for 829 the default ethernet interface, in case this is not 830 determined through e.g. bootp. 831 832- Server IP address: 833 CONFIG_SERVERIP 834 835 Defines a default value for theIP address of a TFTP 836 server to contact when using the "tftboot" command. 837 838- BOOTP Recovery Mode: 839 CONFIG_BOOTP_RANDOM_DELAY 840 841 If you have many targets in a network that try to 842 boot using BOOTP, you may want to avoid that all 843 systems send out BOOTP requests at precisely the same 844 moment (which would happen for instance at recovery 845 from a power failure, when all systems will try to 846 boot, thus flooding the BOOTP server. Defining 847 CONFIG_BOOTP_RANDOM_DELAY causes a random delay to be 848 inserted before sending out BOOTP requests. The 849 following delays are insterted then: 850 851 1st BOOTP request: delay 0 ... 1 sec 852 2nd BOOTP request: delay 0 ... 2 sec 853 3rd BOOTP request: delay 0 ... 4 sec 854 4th and following 855 BOOTP requests: delay 0 ... 8 sec 856 857- Status LED: CONFIG_STATUS_LED 858 859 Several configurations allow to display the current 860 status using a LED. For instance, the LED will blink 861 fast while running U-Boot code, stop blinking as 862 soon as a reply to a BOOTP request was received, and 863 start blinking slow once the Linux kernel is running 864 (supported by a status LED driver in the Linux 865 kernel). Defining CONFIG_STATUS_LED enables this 866 feature in U-Boot. 867 868- CAN Support: CONFIG_CAN_DRIVER 869 870 Defining CONFIG_CAN_DRIVER enables CAN driver support 871 on those systems that support this (optional) 872 feature, like the TQM8xxL modules. 873 874- I2C Support: CONFIG_HARD_I2C | CONFIG_SOFT_I2C 875 876 Enables I2C serial bus commands. If this is selected, 877 either CONFIG_HARD_I2C or CONFIG_SOFT_I2C must be defined 878 to include the appropriate I2C driver. 879 880 See also: common/cmd_i2c.c for a description of the 881 command line interface. 882 883 884 CONFIG_HARD_I2C 885 886 Selects the CPM hardware driver for I2C. 887 888 CONFIG_SOFT_I2C 889 890 Use software (aka bit-banging) driver instead of CPM 891 or similar hardware support for I2C. This is configured 892 via the following defines. 893 894 I2C_INIT 895 896 (Optional). Any commands necessary to enable I2C 897 controller or configure ports. 898 899 I2C_PORT 900 901 (Only for MPC8260 CPU). The I/O port to use (the code 902 assumes both bits are on the same port). Valid values 903 are 0..3 for ports A..D. 904 905 I2C_ACTIVE 906 907 The code necessary to make the I2C data line active 908 (driven). If the data line is open collector, this 909 define can be null. 910 911 I2C_TRISTATE 912 913 The code necessary to make the I2C data line tri-stated 914 (inactive). If the data line is open collector, this 915 define can be null. 916 917 I2C_READ 918 919 Code that returns TRUE if the I2C data line is high, 920 FALSE if it is low. 921 922 I2C_SDA(bit) 923 924 If <bit> is TRUE, sets the I2C data line high. If it 925 is FALSE, it clears it (low). 926 927 I2C_SCL(bit) 928 929 If <bit> is TRUE, sets the I2C clock line high. If it 930 is FALSE, it clears it (low). 931 932 I2C_DELAY 933 934 This delay is invoked four times per clock cycle so this 935 controls the rate of data transfer. The data rate thus 936 is 1 / (I2C_DELAY * 4). 937 938 CFG_I2C_INIT_BOARD 939 940 When a board is reset during an i2c bus transfer 941 chips might think that the current transfer is still 942 in progress. On some boards it is possible to access 943 the i2c SCLK line directly, either by using the 944 processor pin as a GPIO or by having a second pin 945 connected to the bus. If this option is defined a 946 custom i2c_init_board() routine in boards/xxx/board.c 947 is run early in the boot sequence. 948 949- SPI Support: CONFIG_SPI 950 951 Enables SPI driver (so far only tested with 952 SPI EEPROM, also an instance works with Crystal A/D and 953 D/As on the SACSng board) 954 955 CONFIG_SPI_X 956 957 Enables extended (16-bit) SPI EEPROM addressing. 958 (symmetrical to CONFIG_I2C_X) 959 960 CONFIG_SOFT_SPI 961 962 Enables a software (bit-bang) SPI driver rather than 963 using hardware support. This is a general purpose 964 driver that only requires three general I/O port pins 965 (two outputs, one input) to function. If this is 966 defined, the board configuration must define several 967 SPI configuration items (port pins to use, etc). For 968 an example, see include/configs/sacsng.h. 969 970- FPGA Support: CONFIG_FPGA_COUNT 971 972 Specify the number of FPGA devices to support. 973 974 CONFIG_FPGA 975 976 Used to specify the types of FPGA devices. For 977 example, 978 #define CONFIG_FPGA CFG_XILINX_VIRTEX2 979 980 CFG_FPGA_PROG_FEEDBACK 981 982 Enable printing of hash marks during FPGA 983 configuration. 984 985 CFG_FPGA_CHECK_BUSY 986 987 Enable checks on FPGA configuration interface busy 988 status by the configuration function. This option 989 will require a board or device specific function to 990 be written. 991 992 CONFIG_FPGA_DELAY 993 994 If defined, a function that provides delays in the 995 FPGA configuration driver. 996 997 CFG_FPGA_CHECK_CTRLC 998 999 Allow Control-C to interrupt FPGA configuration 1000 1001 CFG_FPGA_CHECK_ERROR 1002 1003 Check for configuration errors during FPGA bitfile 1004 loading. For example, abort during Virtex II 1005 configuration if the INIT_B line goes low (which 1006 indicated a CRC error). 1007 1008 CFG_FPGA_WAIT_INIT 1009 1010 Maximum time to wait for the INIT_B line to deassert 1011 after PROB_B has been deasserted during a Virtex II 1012 FPGA configuration sequence. The default time is 500 mS. 1013 1014 CFG_FPGA_WAIT_BUSY 1015 1016 Maximum time to wait for BUSY to deassert during 1017 Virtex II FPGA configuration. The default is 5 mS. 1018 1019 CFG_FPGA_WAIT_CONFIG 1020 1021 Time to wait after FPGA configuration. The default is 1022 200 mS. 1023 1024- FPGA Support: CONFIG_FPGA_COUNT 1025 1026 Specify the number of FPGA devices to support. 1027 1028 CONFIG_FPGA 1029 1030 Used to specify the types of FPGA devices. For example, 1031 #define CONFIG_FPGA CFG_XILINX_VIRTEX2 1032 1033 CFG_FPGA_PROG_FEEDBACK 1034 1035 Enable printing of hash marks during FPGA configuration. 1036 1037 CFG_FPGA_CHECK_BUSY 1038 1039 Enable checks on FPGA configuration interface busy 1040 status by the configuration function. This option 1041 will require a board or device specific function to 1042 be written. 1043 1044 CONFIG_FPGA_DELAY 1045 1046 If defined, a function that provides delays in the FPGA 1047 configuration driver. 1048 1049 CFG_FPGA_CHECK_CTRLC 1050 Allow Control-C to interrupt FPGA configuration 1051 1052 CFG_FPGA_CHECK_ERROR 1053 1054 Check for configuration errors during FPGA bitfile 1055 loading. For example, abort during Virtex II 1056 configuration if the INIT_B line goes low (which 1057 indicated a CRC error). 1058 1059 CFG_FPGA_WAIT_INIT 1060 1061 Maximum time to wait for the INIT_B line to deassert 1062 after PROB_B has been deasserted during a Virtex II 1063 FPGA configuration sequence. The default time is 500 1064 mS. 1065 1066 CFG_FPGA_WAIT_BUSY 1067 1068 Maximum time to wait for BUSY to deassert during 1069 Virtex II FPGA configuration. The default is 5 mS. 1070 1071 CFG_FPGA_WAIT_CONFIG 1072 1073 Time to wait after FPGA configuration. The default is 1074 200 mS. 1075 1076- Configuration Management: 1077 CONFIG_IDENT_STRING 1078 1079 If defined, this string will be added to the U-Boot 1080 version information (U_BOOT_VERSION) 1081 1082- Vendor Parameter Protection: 1083 1084 U-Boot considers the values of the environment 1085 variables "serial#" (Board Serial Number) and 1086 "ethaddr" (Ethernet Address) to bb parameters that 1087 are set once by the board vendor / manufacturer, and 1088 protects these variables from casual modification by 1089 the user. Once set, these variables are read-only, 1090 and write or delete attempts are rejected. You can 1091 change this behviour: 1092 1093 If CONFIG_ENV_OVERWRITE is #defined in your config 1094 file, the write protection for vendor parameters is 1095 completely disabled. Anybody can change or delete 1096 these parameters. 1097 1098 Alternatively, if you #define _both_ CONFIG_ETHADDR 1099 _and_ CONFIG_OVERWRITE_ETHADDR_ONCE, a default 1100 ethernet address is installed in the environment, 1101 which can be changed exactly ONCE by the user. [The 1102 serial# is unaffected by this, i. e. it remains 1103 read-only.] 1104 1105- Protected RAM: 1106 CONFIG_PRAM 1107 1108 Define this variable to enable the reservation of 1109 "protected RAM", i. e. RAM which is not overwritten 1110 by U-Boot. Define CONFIG_PRAM to hold the number of 1111 kB you want to reserve for pRAM. You can overwrite 1112 this default value by defining an environment 1113 variable "pram" to the number of kB you want to 1114 reserve. Note that the board info structure will 1115 still show the full amount of RAM. If pRAM is 1116 reserved, a new environment variable "mem" will 1117 automatically be defined to hold the amount of 1118 remaining RAM in a form that can be passed as boot 1119 argument to Linux, for instance like that: 1120 1121 setenv bootargs ... mem=\$(mem) 1122 saveenv 1123 1124 This way you can tell Linux not to use this memory, 1125 either, which results in a memory region that will 1126 not be affected by reboots. 1127 1128 *WARNING* If your board configuration uses automatic 1129 detection of the RAM size, you must make sure that 1130 this memory test is non-destructive. So far, the 1131 following board configurations are known to be 1132 "pRAM-clean": 1133 1134 ETX094, IVMS8, IVML24, SPD8xx, TQM8xxL, 1135 HERMES, IP860, RPXlite, LWMON, LANTEC, 1136 PCU_E, FLAGADM, TQM8260 1137 1138- Error Recovery: 1139 CONFIG_PANIC_HANG 1140 1141 Define this variable to stop the system in case of a 1142 fatal error, so that you have to reset it manually. 1143 This is probably NOT a good idea for an embedded 1144 system where you want to system to reboot 1145 automatically as fast as possible, but it may be 1146 useful during development since you can try to debug 1147 the conditions that lead to the situation. 1148 1149 CONFIG_NET_RETRY_COUNT 1150 1151 This variable defines the number of retries for 1152 network operations like ARP, RARP, TFTP, or BOOTP 1153 before giving up the operation. If not defined, a 1154 default value of 5 is used. 1155 1156- Command Interpreter: 1157 CFG_HUSH_PARSER 1158 1159 Define this variable to enable the "hush" shell (from 1160 Busybox) as command line interpreter, thus enabling 1161 powerful command line syntax like 1162 if...then...else...fi conditionals or `&&' and '||' 1163 constructs ("shell scripts"). 1164 1165 If undefined, you get the old, much simpler behaviour 1166 with a somewhat smaller memory footprint. 1167 1168 1169 CFG_PROMPT_HUSH_PS2 1170 1171 This defines the secondary prompt string, which is 1172 printed when the command interpreter needs more input 1173 to complete a command. Usually "> ". 1174 1175 Note: 1176 1177 In the current implementation, the local variables 1178 space and global environment variables space are 1179 separated. Local variables are those you define by 1180 simply typing like `name=value'. To access a local 1181 variable later on, you have write `$name' or 1182 `${name}'; variable directly by typing say `$name' at 1183 the command prompt. 1184 1185 Global environment variables are those you use 1186 setenv/printenv to work with. To run a command stored 1187 in such a variable, you need to use the run command, 1188 and you must not use the '$' sign to access them. 1189 1190 To store commands and special characters in a 1191 variable, please use double quotation marks 1192 surrounding the whole text of the variable, instead 1193 of the backslashes before semicolons and special 1194 symbols. 1195 1196- Default Environment 1197 CONFIG_EXTRA_ENV_SETTINGS 1198 1199 Define this to contain any number of null terminated 1200 strings (variable = value pairs) that will be part of 1201 the default enviroment compiled into the boot image. 1202 1203 For example, place something like this in your 1204 board's config file: 1205 1206 #define CONFIG_EXTRA_ENV_SETTINGS \ 1207 "myvar1=value1\0" \ 1208 "myvar2=value2\0" 1209 1210 Warning: This method is based on knowledge about the 1211 internal format how the environment is stored by the 1212 U-Boot code. This is NOT an official, exported 1213 interface! Although it is unlikely that this format 1214 will change soon, but there is no guarantee either. 1215 You better know what you are doing here. 1216 1217 Note: overly (ab)use of the default environment is 1218 discouraged. Make sure to check other ways to preset 1219 the environment like the autoscript function or the 1220 boot command first. 1221 1222- Show boot progress 1223 CONFIG_SHOW_BOOT_PROGRESS 1224 1225 Defining this option allows to add some board- 1226 specific code (calling a user-provided function 1227 "show_boot_progress(int)") that enables you to show 1228 the system's boot progress on some display (for 1229 example, some LED's) on your board. At the moment, 1230 the following checkpoints are implemented: 1231 1232 Arg Where When 1233 1 common/cmd_bootm.c before attempting to boot an image 1234 -1 common/cmd_bootm.c Image header has bad magic number 1235 2 common/cmd_bootm.c Image header has correct magic number 1236 -2 common/cmd_bootm.c Image header has bad checksum 1237 3 common/cmd_bootm.c Image header has correct checksum 1238 -3 common/cmd_bootm.c Image data has bad checksum 1239 4 common/cmd_bootm.c Image data has correct checksum 1240 -4 common/cmd_bootm.c Image is for unsupported architecture 1241 5 common/cmd_bootm.c Architecture check OK 1242 -5 common/cmd_bootm.c Wrong Image Type (not kernel, multi, standalone) 1243 6 common/cmd_bootm.c Image Type check OK 1244 -6 common/cmd_bootm.c gunzip uncompression error 1245 -7 common/cmd_bootm.c Unimplemented compression type 1246 7 common/cmd_bootm.c Uncompression OK 1247 -8 common/cmd_bootm.c Wrong Image Type (not kernel, multi, standalone) 1248 8 common/cmd_bootm.c Image Type check OK 1249 -9 common/cmd_bootm.c Unsupported OS (not Linux, BSD, VxWorks, QNX) 1250 9 common/cmd_bootm.c Start initial ramdisk verification 1251 -10 common/cmd_bootm.c Ramdisk header has bad magic number 1252 -11 common/cmd_bootm.c Ramdisk header has bad checksum 1253 10 common/cmd_bootm.c Ramdisk header is OK 1254 -12 common/cmd_bootm.c Ramdisk data has bad checksum 1255 11 common/cmd_bootm.c Ramdisk data has correct checksum 1256 12 common/cmd_bootm.c Ramdisk verification complete, start loading 1257 -13 common/cmd_bootm.c Wrong Image Type (not PPC Linux Ramdisk) 1258 13 common/cmd_bootm.c Start multifile image verification 1259 14 common/cmd_bootm.c No initial ramdisk, no multifile, continue. 1260 15 common/cmd_bootm.c All preparation done, transferring control to OS 1261 1262 -1 common/cmd_doc.c Bad usage of "doc" command 1263 -1 common/cmd_doc.c No boot device 1264 -1 common/cmd_doc.c Unknown Chip ID on boot device 1265 -1 common/cmd_doc.c Read Error on boot device 1266 -1 common/cmd_doc.c Image header has bad magic number 1267 1268 -1 common/cmd_ide.c Bad usage of "ide" command 1269 -1 common/cmd_ide.c No boot device 1270 -1 common/cmd_ide.c Unknown boot device 1271 -1 common/cmd_ide.c Unknown partition table 1272 -1 common/cmd_ide.c Invalid partition type 1273 -1 common/cmd_ide.c Read Error on boot device 1274 -1 common/cmd_ide.c Image header has bad magic number 1275 1276 -1 common/cmd_nvedit.c Environment not changable, but has bad CRC 1277 1278 1279Modem Support: 1280-------------- 1281 1282[so far only for SMDK2400 and TRAB boards] 1283 1284- Modem support endable: 1285 CONFIG_MODEM_SUPPORT 1286 1287- RTS/CTS Flow control enable: 1288 CONFIG_HWFLOW 1289 1290- Modem debug support: 1291 CONFIG_MODEM_SUPPORT_DEBUG 1292 1293 Enables debugging stuff (char screen[1024], dbg()) 1294 for modem support. Useful only with BDI2000. 1295 1296- General: 1297 1298 In the target system modem support is enabled when a 1299 specific key (key combination) is pressed during 1300 power-on. Otherwise U-Boot will boot normally 1301 (autoboot). The key_pressed() fuction is called from 1302 board_init(). Currently key_pressed() is a dummy 1303 function, returning 1 and thus enabling modem 1304 initialization. 1305 1306 If there are no modem init strings in the 1307 environment, U-Boot proceed to autoboot; the 1308 previous output (banner, info printfs) will be 1309 supressed, though. 1310 1311 See also: doc/README.Modem 1312 1313 1314 1315 1316Configuration Settings: 1317----------------------- 1318 1319- CFG_LONGHELP: Defined when you want long help messages included; 1320 undefine this when you're short of memory. 1321 1322- CFG_PROMPT: This is what U-Boot prints on the console to 1323 prompt for user input. 1324 1325- CFG_CBSIZE: Buffer size for input from the Console 1326 1327- CFG_PBSIZE: Buffer size for Console output 1328 1329- CFG_MAXARGS: max. Number of arguments accepted for monitor commands 1330 1331- CFG_BARGSIZE: Buffer size for Boot Arguments which are passed to 1332 the application (usually a Linux kernel) when it is 1333 booted 1334 1335- CFG_BAUDRATE_TABLE: 1336 List of legal baudrate settings for this board. 1337 1338- CFG_CONSOLE_INFO_QUIET 1339 Suppress display of console information at boot. 1340 1341- CFG_CONSOLE_IS_IN_ENV 1342 If the board specific function 1343 extern int overwrite_console (void); 1344 returns 1, the stdin, stderr and stdout are switched to the 1345 serial port, else the settings in the environment are used. 1346 1347- CFG_CONSOLE_OVERWRITE_ROUTINE 1348 Enable the call to overwrite_console(). 1349 1350- CFG_CONSOLE_ENV_OVERWRITE 1351 Enable overwrite of previous console environment settings. 1352 1353- CFG_MEMTEST_START, CFG_MEMTEST_END: 1354 Begin and End addresses of the area used by the 1355 simple memory test. 1356 1357- CFG_ALT_MEMTEST: 1358 Enable an alternate, more extensive memory test. 1359 1360- CFG_TFTP_LOADADDR: 1361 Default load address for network file downloads 1362 1363- CFG_LOADS_BAUD_CHANGE: 1364 Enable temporary baudrate change while serial download 1365 1366- CFG_SDRAM_BASE: 1367 Physical start address of SDRAM. _Must_ be 0 here. 1368 1369- CFG_MBIO_BASE: 1370 Physical start address of Motherboard I/O (if using a 1371 Cogent motherboard) 1372 1373- CFG_FLASH_BASE: 1374 Physical start address of Flash memory. 1375 1376- CFG_MONITOR_BASE: 1377 Physical start address of boot monitor code (set by 1378 make config files to be same as the text base address 1379 (TEXT_BASE) used when linking) - same as 1380 CFG_FLASH_BASE when booting from flash. 1381 1382- CFG_MONITOR_LEN: 1383 Size of memory reserved for monitor code 1384 1385- CFG_MALLOC_LEN: 1386 Size of DRAM reserved for malloc() use. 1387 1388- CFG_BOOTMAPSZ: 1389 Maximum size of memory mapped by the startup code of 1390 the Linux kernel; all data that must be processed by 1391 the Linux kernel (bd_info, boot arguments, eventually 1392 initrd image) must be put below this limit. 1393 1394- CFG_MAX_FLASH_BANKS: 1395 Max number of Flash memory banks 1396 1397- CFG_MAX_FLASH_SECT: 1398 Max number of sectors on a Flash chip 1399 1400- CFG_FLASH_ERASE_TOUT: 1401 Timeout for Flash erase operations (in ms) 1402 1403- CFG_FLASH_WRITE_TOUT: 1404 Timeout for Flash write operations (in ms) 1405 1406- CFG_DIRECT_FLASH_TFTP: 1407 1408 Enable TFTP transfers directly to flash memory; 1409 without this option such a download has to be 1410 performed in two steps: (1) download to RAM, and (2) 1411 copy from RAM to flash. 1412 1413 The two-step approach is usually more reliable, since 1414 you can check if the download worked before you erase 1415 the flash, but in some situations (when sytem RAM is 1416 too limited to allow for a tempory copy of the 1417 downloaded image) this option may be very useful. 1418 1419- CFG_FLASH_CFI: 1420 Define if the flash driver uses extra elements in the 1421 common flash structure for storing flash geometry 1422 1423The following definitions that deal with the placement and management 1424of environment data (variable area); in general, we support the 1425following configurations: 1426 1427- CFG_ENV_IS_IN_FLASH: 1428 1429 Define this if the environment is in flash memory. 1430 1431 a) The environment occupies one whole flash sector, which is 1432 "embedded" in the text segment with the U-Boot code. This 1433 happens usually with "bottom boot sector" or "top boot 1434 sector" type flash chips, which have several smaller 1435 sectors at the start or the end. For instance, such a 1436 layout can have sector sizes of 8, 2x4, 16, Nx32 kB. In 1437 such a case you would place the environment in one of the 1438 4 kB sectors - with U-Boot code before and after it. With 1439 "top boot sector" type flash chips, you would put the 1440 environment in one of the last sectors, leaving a gap 1441 between U-Boot and the environment. 1442 1443 - CFG_ENV_OFFSET: 1444 1445 Offset of environment data (variable area) to the 1446 beginning of flash memory; for instance, with bottom boot 1447 type flash chips the second sector can be used: the offset 1448 for this sector is given here. 1449 1450 CFG_ENV_OFFSET is used relative to CFG_FLASH_BASE. 1451 1452 - CFG_ENV_ADDR: 1453 1454 This is just another way to specify the start address of 1455 the flash sector containing the environment (instead of 1456 CFG_ENV_OFFSET). 1457 1458 - CFG_ENV_SECT_SIZE: 1459 1460 Size of the sector containing the environment. 1461 1462 1463 b) Sometimes flash chips have few, equal sized, BIG sectors. 1464 In such a case you don't want to spend a whole sector for 1465 the environment. 1466 1467 - CFG_ENV_SIZE: 1468 1469 If you use this in combination with CFG_ENV_IS_IN_FLASH 1470 and CFG_ENV_SECT_SIZE, you can specify to use only a part 1471 of this flash sector for the environment. This saves 1472 memory for the RAM copy of the environment. 1473 1474 It may also save flash memory if you decide to use this 1475 when your environment is "embedded" within U-Boot code, 1476 since then the remainder of the flash sector could be used 1477 for U-Boot code. It should be pointed out that this is 1478 STRONGLY DISCOURAGED from a robustness point of view: 1479 updating the environment in flash makes it always 1480 necessary to erase the WHOLE sector. If something goes 1481 wrong before the contents has been restored from a copy in 1482 RAM, your target system will be dead. 1483 1484 - CFG_ENV_ADDR_REDUND 1485 CFG_ENV_SIZE_REDUND 1486 1487 These settings describe a second storage area used to hold 1488 a redundand copy of the environment data, so that there is 1489 a valid backup copy in case there is a power failure during 1490 a "saveenv" operation. 1491 1492BE CAREFUL! Any changes to the flash layout, and some changes to the 1493source code will make it necessary to adapt <board>/u-boot.lds* 1494accordingly! 1495 1496 1497- CFG_ENV_IS_IN_NVRAM: 1498 1499 Define this if you have some non-volatile memory device 1500 (NVRAM, battery buffered SRAM) which you want to use for the 1501 environment. 1502 1503 - CFG_ENV_ADDR: 1504 - CFG_ENV_SIZE: 1505 1506 These two #defines are used to determin the memory area you 1507 want to use for environment. It is assumed that this memory 1508 can just be read and written to, without any special 1509 provision. 1510 1511BE CAREFUL! The first access to the environment happens quite early 1512in U-Boot initalization (when we try to get the setting of for the 1513console baudrate). You *MUST* have mappend your NVRAM area then, or 1514U-Boot will hang. 1515 1516Please note that even with NVRAM we still use a copy of the 1517environment in RAM: we could work on NVRAM directly, but we want to 1518keep settings there always unmodified except somebody uses "saveenv" 1519to save the current settings. 1520 1521 1522- CFG_ENV_IS_IN_EEPROM: 1523 1524 Use this if you have an EEPROM or similar serial access 1525 device and a driver for it. 1526 1527 - CFG_ENV_OFFSET: 1528 - CFG_ENV_SIZE: 1529 1530 These two #defines specify the offset and size of the 1531 environment area within the total memory of your EEPROM. 1532 1533 - CFG_I2C_EEPROM_ADDR: 1534 If defined, specified the chip address of the EEPROM device. 1535 The default address is zero. 1536 1537 - CFG_EEPROM_PAGE_WRITE_BITS: 1538 If defined, the number of bits used to address bytes in a 1539 single page in the EEPROM device. A 64 byte page, for example 1540 would require six bits. 1541 1542 - CFG_EEPROM_PAGE_WRITE_DELAY_MS: 1543 If defined, the number of milliseconds to delay between 1544 page writes. The default is zero milliseconds. 1545 1546 - CFG_I2C_EEPROM_ADDR_LEN: 1547 The length in bytes of the EEPROM memory array address. Note 1548 that this is NOT the chip address length! 1549 1550 - CFG_EEPROM_SIZE: 1551 The size in bytes of the EEPROM device. 1552 1553 1554- CFG_SPI_INIT_OFFSET 1555 1556 Defines offset to the initial SPI buffer area in DPRAM. The 1557 area is used at an early stage (ROM part) if the environment 1558 is configured to reside in the SPI EEPROM: We need a 520 byte 1559 scratch DPRAM area. It is used between the two initialization 1560 calls (spi_init_f() and spi_init_r()). A value of 0xB00 seems 1561 to be a good choice since it makes it far enough from the 1562 start of the data area as well as from the stack pointer. 1563 1564Please note that the environment is read-only as long as the monitor 1565has been relocated to RAM and a RAM copy of the environment has been 1566created; also, when using EEPROM you will have to use getenv_r() 1567until then to read environment variables. 1568 1569The environment is protected by a CRC32 checksum. Before the monitor 1570is relocated into RAM, as a result of a bad CRC you will be working 1571with the compiled-in default environment - *silently*!!! [This is 1572necessary, because the first environment variable we need is the 1573"baudrate" setting for the console - if we have a bad CRC, we don't 1574have any device yet where we could complain.] 1575 1576Note: once the monitor has been relocated, then it will complain if 1577the default environment is used; a new CRC is computed as soon as you 1578use the "saveenv" command to store a valid environment. 1579 1580 1581Low Level (hardware related) configuration options: 1582--------------------------------------------------- 1583 1584- CFG_CACHELINE_SIZE: 1585 Cache Line Size of the CPU. 1586 1587- CFG_DEFAULT_IMMR: 1588 Default address of the IMMR after system reset. 1589 Needed on some 8260 systems (MPC8260ADS and RPXsuper) 1590 to be able to adjust the position of the IMMR 1591 register after a reset. 1592 1593- Floppy Disk Support: 1594 CFG_FDC_DRIVE_NUMBER 1595 1596 the default drive number (default value 0) 1597 1598 CFG_ISA_IO_STRIDE 1599 1600 defines the spacing between fdc chipset registers 1601 (default value 1) 1602 1603 CFG_ISA_IO_OFFSET 1604 1605 defines the offset of register from address. It 1606 depends on which part of the data bus is connected to 1607 the fdc chipset. (default value 0) 1608 1609 If CFG_ISA_IO_STRIDE CFG_ISA_IO_OFFSET and 1610 CFG_FDC_DRIVE_NUMBER are undefined, they take their 1611 default value. 1612 1613 if CFG_FDC_HW_INIT is defined, then the function 1614 fdc_hw_init() is called at the beginning of the FDC 1615 setup. fdc_hw_init() must be provided by the board 1616 source code. It is used to make hardware dependant 1617 initializations. 1618 1619- CFG_IMMR: Physical address of the Internal Memory Mapped 1620 Register; DO NOT CHANGE! (11-4) 1621 [MPC8xx systems only] 1622 1623- CFG_INIT_RAM_ADDR: 1624 1625 Start address of memory area tha can be used for 1626 initial data and stack; please note that this must be 1627 writable memory that is working WITHOUT special 1628 initialization, i. e. you CANNOT use normal RAM which 1629 will become available only after programming the 1630 memory controller and running certain initialization 1631 sequences. 1632 1633 U-Boot uses the following memory types: 1634 - MPC8xx and MPC8260: IMMR (internal memory of the CPU) 1635 - MPC824X: data cache 1636 - PPC4xx: data cache 1637 1638- CFG_GBL_DATA_OFFSET: 1639 1640 Offset of the initial data structure in the memory 1641 area defined by CFG_INIT_RAM_ADDR. Usually 1642 CFG_GBL_DATA_OFFSET is chosen such that the initial 1643 data is located at the end of the available space 1644 (sometimes written as (CFG_INIT_RAM_END - 1645 CFG_INIT_DATA_SIZE), and the initial stack is just 1646 below that area (growing from (CFG_INIT_RAM_ADDR + 1647 CFG_GBL_DATA_OFFSET) downward. 1648 1649 Note: 1650 On the MPC824X (or other systems that use the data 1651 cache for initial memory) the address chosen for 1652 CFG_INIT_RAM_ADDR is basically arbitrary - it must 1653 point to an otherwise UNUSED address space between 1654 the top of RAM and the start of the PCI space. 1655 1656- CFG_SIUMCR: SIU Module Configuration (11-6) 1657 1658- CFG_SYPCR: System Protection Control (11-9) 1659 1660- CFG_TBSCR: Time Base Status and Control (11-26) 1661 1662- CFG_PISCR: Periodic Interrupt Status and Control (11-31) 1663 1664- CFG_PLPRCR: PLL, Low-Power, and Reset Control Register (15-30) 1665 1666- CFG_SCCR: System Clock and reset Control Register (15-27) 1667 1668- CFG_OR_TIMING_SDRAM: 1669 SDRAM timing 1670 1671- CFG_MAMR_PTA: 1672 periodic timer for refresh 1673 1674- CFG_DER: Debug Event Register (37-47) 1675 1676- FLASH_BASE0_PRELIM, FLASH_BASE1_PRELIM, CFG_REMAP_OR_AM, 1677 CFG_PRELIM_OR_AM, CFG_OR_TIMING_FLASH, CFG_OR0_REMAP, 1678 CFG_OR0_PRELIM, CFG_BR0_PRELIM, CFG_OR1_REMAP, CFG_OR1_PRELIM, 1679 CFG_BR1_PRELIM: 1680 Memory Controller Definitions: BR0/1 and OR0/1 (FLASH) 1681 1682- SDRAM_BASE2_PRELIM, SDRAM_BASE3_PRELIM, SDRAM_MAX_SIZE, 1683 CFG_OR_TIMING_SDRAM, CFG_OR2_PRELIM, CFG_BR2_PRELIM, 1684 CFG_OR3_PRELIM, CFG_BR3_PRELIM: 1685 Memory Controller Definitions: BR2/3 and OR2/3 (SDRAM) 1686 1687- CFG_MAMR_PTA, CFG_MPTPR_2BK_4K, CFG_MPTPR_1BK_4K, CFG_MPTPR_2BK_8K, 1688 CFG_MPTPR_1BK_8K, CFG_MAMR_8COL, CFG_MAMR_9COL: 1689 Machine Mode Register and Memory Periodic Timer 1690 Prescaler definitions (SDRAM timing) 1691 1692- CFG_I2C_UCODE_PATCH, CFG_I2C_DPMEM_OFFSET [0x1FC0]: 1693 enable I2C microcode relocation patch (MPC8xx); 1694 define relocation offset in DPRAM [DSP2] 1695 1696- CFG_SPI_UCODE_PATCH, CFG_SPI_DPMEM_OFFSET [0x1FC0]: 1697 enable SPI microcode relocation patch (MPC8xx); 1698 define relocation offset in DPRAM [SCC4] 1699 1700- CFG_USE_OSCCLK: 1701 Use OSCM clock mode on MBX8xx board. Be careful, 1702 wrong setting might damage your board. Read 1703 doc/README.MBX before setting this variable! 1704 1705- CFG_CPM_POST_WORD_ADDR: (MPC8xx, MPC8260 only) 1706 Offset of the bootmode word in DPRAM used by post 1707 (Power On Self Tests). This definition overrides 1708 #define'd default value in commproc.h resp. 1709 cpm_8260.h. 1710 1711Building the Software: 1712====================== 1713 1714Building U-Boot has been tested in native PPC environments (on a 1715PowerBook G3 running LinuxPPC 2000) and in cross environments 1716(running RedHat 6.x and 7.x Linux on x86, Solaris 2.6 on a SPARC, and 1717NetBSD 1.5 on x86). 1718 1719If you are not using a native PPC environment, it is assumed that you 1720have the GNU cross compiling tools available in your path and named 1721with a prefix of "powerpc-linux-". If this is not the case, (e.g. if 1722you are using Monta Vista's Hard Hat Linux CDK 1.2) you must change 1723the definition of CROSS_COMPILE in Makefile. For HHL on a 4xx CPU, 1724change it to: 1725 1726 CROSS_COMPILE = ppc_4xx- 1727 1728 1729U-Boot is intended to be simple to build. After installing the 1730sources you must configure U-Boot for one specific board type. This 1731is done by typing: 1732 1733 make NAME_config 1734 1735where "NAME_config" is the name of one of the existing 1736configurations; the following names are supported: 1737 1738 ADCIOP_config GTH_config TQM850L_config 1739 ADS860_config IP860_config TQM855L_config 1740 AR405_config IVML24_config TQM860L_config 1741 CANBT_config IVMS8_config WALNUT405_config 1742 CPCI405_config LANTEC_config cogent_common_config 1743 CPCIISER4_config MBX_config cogent_mpc8260_config 1744 CU824_config MBX860T_config cogent_mpc8xx_config 1745 ESTEEM192E_config RPXlite_config hermes_config 1746 ETX094_config RPXsuper_config hymod_config 1747 FADS823_config SM850_config lwmon_config 1748 FADS850SAR_config SPD823TS_config pcu_e_config 1749 FADS860T_config SXNI855T_config rsdproto_config 1750 FPS850L_config Sandpoint8240_config sbc8260_config 1751 GENIETV_config TQM823L_config PIP405_config 1752 GEN860T_config EBONY_config FPS860L_config 1753 ELPT860_config cmi_mpc5xx_config 1754 1755Note: for some board special configuration names may exist; check if 1756 additional information is available from the board vendor; for 1757 instance, the TQM8xxL systems run normally at 50 MHz and use a 1758 SCC for 10baseT ethernet; there are also systems with 80 MHz 1759 CPU clock, and an optional Fast Ethernet module is available 1760 for CPU's with FEC. You can select such additional "features" 1761 when chosing the configuration, i. e. 1762 1763 make TQM860L_config 1764 - will configure for a plain TQM860L, i. e. 50MHz, no FEC 1765 1766 make TQM860L_FEC_config 1767 - will configure for a TQM860L at 50MHz with FEC for ethernet 1768 1769 make TQM860L_80MHz_config 1770 - will configure for a TQM860L at 80 MHz, with normal 10baseT 1771 interface 1772 1773 make TQM860L_FEC_80MHz_config 1774 - will configure for a TQM860L at 80 MHz with FEC for ethernet 1775 1776 make TQM823L_LCD_config 1777 - will configure for a TQM823L with U-Boot console on LCD 1778 1779 make TQM823L_LCD_80MHz_config 1780 - will configure for a TQM823L at 80 MHz with U-Boot console on LCD 1781 1782 etc. 1783 1784 1785 1786Finally, type "make all", and you should get some working U-Boot 1787images ready for downlod to / installation on your system: 1788 1789- "u-boot.bin" is a raw binary image 1790- "u-boot" is an image in ELF binary format 1791- "u-boot.srec" is in Motorola S-Record format 1792 1793 1794Please be aware that the Makefiles assume you are using GNU make, so 1795for instance on NetBSD you might need to use "gmake" instead of 1796native "make". 1797 1798 1799If the system board that you have is not listed, then you will need 1800to port U-Boot to your hardware platform. To do this, follow these 1801steps: 1802 18031. Add a new configuration option for your board to the toplevel 1804 "Makefile" and to the "MAKEALL" script, using the existing 1805 entries as examples. Note that here and at many other places 1806 boards and other names are listed alphabetically sorted. Please 1807 keep this order. 18082. Create a new directory to hold your board specific code. Add any 1809 files you need. In your board directory, you will need at least 1810 the "Makefile", a "<board>.c", "flash.c" and "u-boot.lds". 18113. Create a new configuration file "include/configs/<board>.h" for 1812 your board 18133. If you're porting U-Boot to a new CPU, then also create a new 1814 directory to hold your CPU specific code. Add any files you need. 18154. Run "make <board>_config" with your new name. 18165. Type "make", and you should get a working "u-boot.srec" file 1817 to be installed on your target system. 18186. Debug and solve any problems that might arise. 1819 [Of course, this last step is much harder than it sounds.] 1820 1821 1822Testing of U-Boot Modifications, Ports to New Hardware, etc.: 1823============================================================== 1824 1825If you have modified U-Boot sources (for instance added a new board 1826or support for new devices, a new CPU, etc.) you are expected to 1827provide feedback to the other developers. The feedback normally takes 1828the form of a "patch", i. e. a context diff against a certain (latest 1829official or latest in CVS) version of U-Boot sources. 1830 1831But before you submit such a patch, please verify that your modifi- 1832cation did not break existing code. At least make sure that *ALL* of 1833the supported boards compile WITHOUT ANY compiler warnings. To do so, 1834just run the "MAKEALL" script, which will configure and build U-Boot 1835for ALL supported system. Be warned, this will take a while. You can 1836select which (cross) compiler to use py passing a `CROSS_COMPILE' 1837environment variable to the script, i. e. to use the cross tools from 1838MontaVista's Hard Hat Linux you can type 1839 1840 CROSS_COMPILE=ppc_8xx- MAKEALL 1841 1842or to build on a native PowerPC system you can type 1843 1844 CROSS_COMPILE=' ' MAKEALL 1845 1846See also "U-Boot Porting Guide" below. 1847 1848 1849 1850Monitor Commands - Overview: 1851============================ 1852 1853go - start application at address 'addr' 1854run - run commands in an environment variable 1855bootm - boot application image from memory 1856bootp - boot image via network using BootP/TFTP protocol 1857tftpboot- boot image via network using TFTP protocol 1858 and env variables "ipaddr" and "serverip" 1859 (and eventually "gatewayip") 1860rarpboot- boot image via network using RARP/TFTP protocol 1861diskboot- boot from IDE devicebootd - boot default, i.e., run 'bootcmd' 1862loads - load S-Record file over serial line 1863loadb - load binary file over serial line (kermit mode) 1864md - memory display 1865mm - memory modify (auto-incrementing) 1866nm - memory modify (constant address) 1867mw - memory write (fill) 1868cp - memory copy 1869cmp - memory compare 1870crc32 - checksum calculation 1871imd - i2c memory display 1872imm - i2c memory modify (auto-incrementing) 1873inm - i2c memory modify (constant address) 1874imw - i2c memory write (fill) 1875icrc32 - i2c checksum calculation 1876iprobe - probe to discover valid I2C chip addresses 1877iloop - infinite loop on address range 1878isdram - print SDRAM configuration information 1879sspi - SPI utility commands 1880base - print or set address offset 1881printenv- print environment variables 1882setenv - set environment variables 1883saveenv - save environment variables to persistent storage 1884protect - enable or disable FLASH write protection 1885erase - erase FLASH memory 1886flinfo - print FLASH memory information 1887bdinfo - print Board Info structure 1888iminfo - print header information for application image 1889coninfo - print console devices and informations 1890ide - IDE sub-system 1891loop - infinite loop on address range 1892mtest - simple RAM test 1893icache - enable or disable instruction cache 1894dcache - enable or disable data cache 1895reset - Perform RESET of the CPU 1896echo - echo args to console 1897version - print monitor version 1898help - print online help 1899? - alias for 'help' 1900 1901 1902Monitor Commands - Detailed Description: 1903======================================== 1904 1905TODO. 1906 1907For now: just type "help <command>". 1908 1909 1910Environment Variables: 1911====================== 1912 1913U-Boot supports user configuration using Environment Variables which 1914can be made persistent by saving to Flash memory. 1915 1916Environment Variables are set using "setenv", printed using 1917"printenv", and saved to Flash using "saveenv". Using "setenv" 1918without a value can be used to delete a variable from the 1919environment. As long as you don't save the environment you are 1920working with an in-memory copy. In case the Flash area containing the 1921environment is erased by accident, a default environment is provided. 1922 1923Some configuration options can be set using Environment Variables: 1924 1925 baudrate - see CONFIG_BAUDRATE 1926 1927 bootdelay - see CONFIG_BOOTDELAY 1928 1929 bootcmd - see CONFIG_BOOTCOMMAND 1930 1931 bootargs - Boot arguments when booting an RTOS image 1932 1933 bootfile - Name of the image to load with TFTP 1934 1935 autoload - if set to "no" (any string beginning with 'n'), 1936 "bootp" will just load perform a lookup of the 1937 configuration from the BOOTP server, but not try to 1938 load any image using TFTP 1939 1940 autostart - if set to "yes", an image loaded using the "bootp", 1941 "rarpboot", "tftpboot" or "diskboot" commands will 1942 be automatically started (by internally calling 1943 "bootm") 1944 1945 If set to "no", a standalone image passed to the 1946 "bootm" command will be copied to the load address 1947 (and eventually uncompressed), but NOT be started. 1948 This can be used to load and uncompress arbitrary 1949 data. 1950 1951 initrd_high - restrict positioning of initrd images: 1952 If this variable is not set, initrd images will be 1953 copied to the highest possible address in RAM; this 1954 is usually what you want since it allows for 1955 maximum initrd size. If for some reason you want to 1956 make sure that the initrd image is loaded below the 1957 CFG_BOOTMAPSZ limit, you can set this environment 1958 variable to a value of "no" or "off" or "0". 1959 Alternatively, you can set it to a maximum upper 1960 address to use (U-Boot will still check that it 1961 does not overwrite the U-Boot stack and data). 1962 1963 For instance, when you have a system with 16 MB 1964 RAM, and want to reseve 4 MB from use by Linux, 1965 you can do this by adding "mem=12M" to the value of 1966 the "bootargs" variable. However, now you must make 1967 sure, that the initrd image is placed in the first 1968 12 MB as well - this can be done with 1969 1970 setenv initrd_high 00c00000 1971 1972 ipaddr - IP address; needed for tftpboot command 1973 1974 loadaddr - Default load address for commands like "bootp", 1975 "rarpboot", "tftpboot", "loadb" or "diskboot" 1976 1977 loads_echo - see CONFIG_LOADS_ECHO 1978 1979 serverip - TFTP server IP address; needed for tftpboot command 1980 1981 bootretry - see CONFIG_BOOT_RETRY_TIME 1982 1983 bootdelaykey - see CONFIG_AUTOBOOT_DELAY_STR 1984 1985 bootstopkey - see CONFIG_AUTOBOOT_STOP_STR 1986 1987 1988The following environment variables may be used and automatically 1989updated by the network boot commands ("bootp" and "rarpboot"), 1990depending the information provided by your boot server: 1991 1992 bootfile - see above 1993 dnsip - IP address of your Domain Name Server 1994 gatewayip - IP address of the Gateway (Router) to use 1995 hostname - Target hostname 1996 ipaddr - see above 1997 netmask - Subnet Mask 1998 rootpath - Pathname of the root filesystem on the NFS server 1999 serverip - see above 2000 2001 2002There are two special Environment Variables: 2003 2004 serial# - contains hardware identification information such 2005 as type string and/or serial number 2006 ethaddr - Ethernet address 2007 2008These variables can be set only once (usually during manufacturing of 2009the board). U-Boot refuses to delete or overwrite these variables 2010once they have been set once. 2011 2012 2013Further special Environment Variables: 2014 2015 ver - Contains the U-Boot version string as printed 2016 with the "version" command. This variable is 2017 readonly (see CONFIG_VERSION_VARIABLE). 2018 2019 2020Please note that changes to some configuration parameters may take 2021only effect after the next boot (yes, that's just like Windoze :-). 2022 2023 2024Note for Redundant Ethernet Interfaces: 2025======================================= 2026 2027Some boards come with redundand ethernet interfaces; U-Boot supports 2028such configurations and is capable of automatic selection of a 2029"working" interface when needed. MAC assignemnt works as follows: 2030 2031Network interfaces are numbered eth0, eth1, eth2, ... Corresponding 2032MAC addresses can be stored in the environment as "ethaddr" (=>eth0), 2033"eth1addr" (=>eth1), "eth2addr", ... 2034 2035If the network interface stores some valid MAC address (for instance 2036in SROM), this is used as default address if there is NO correspon- 2037ding setting in the environment; if the corresponding environment 2038variable is set, this overrides the settings in the card; that means: 2039 2040o If the SROM has a valid MAC address, and there is no address in the 2041 environment, the SROM's address is used. 2042 2043o If there is no valid address in the SROM, and a definition in the 2044 environment exists, then the value from the environment variable is 2045 used. 2046 2047o If both the SROM and the environment contain a MAC address, and 2048 both addresses are the same, this MAC address is used. 2049 2050o If both the SROM and the environment contain a MAC address, and the 2051 addresses differ, the value from the environment is used and a 2052 warning is printed. 2053 2054o If neither SROM nor the environment contain a MAC address, an error 2055 is raised. 2056 2057 2058 2059Image Formats: 2060============== 2061 2062The "boot" commands of this monitor operate on "image" files which 2063can be basicly anything, preceeded by a special header; see the 2064definitions in include/image.h for details; basicly, the header 2065defines the following image properties: 2066 2067* Target Operating System (Provisions for OpenBSD, NetBSD, FreeBSD, 2068 4.4BSD, Linux, SVR4, Esix, Solaris, Irix, SCO, Dell, NCR, VxWorks, 2069 LynxOS, pSOS, QNX; 2070 Currently supported: Linux, NetBSD, VxWorks, QNX). 2071* Target CPU Architecture (Provisions for Alpha, ARM, Intel x86, 2072 IA64, MIPS, MIPS, PowerPC, IBM S390, SuperH, Sparc, Sparc 64 Bit; 2073 Currently supported: PowerPC). 2074* Compression Type (Provisions for uncompressed, gzip, bzip2; 2075 Currently supported: uncompressed, gzip). 2076* Load Address 2077* Entry Point 2078* Image Name 2079* Image Timestamp 2080 2081The header is marked by a special Magic Number, and both the header 2082and the data portions of the image are secured against corruption by 2083CRC32 checksums. 2084 2085 2086Linux Support: 2087============== 2088 2089Although U-Boot should support any OS or standalone application 2090easily, Linux has always been in the focus during the design of 2091U-Boot. 2092 2093U-Boot includes many features that so far have been part of some 2094special "boot loader" code within the Linux kernel. Also, any 2095"initrd" images to be used are no longer part of one big Linux image; 2096instead, kernel and "initrd" are separate images. This implementation 2097serves serveral purposes: 2098 2099- the same features can be used for other OS or standalone 2100 applications (for instance: using compressed images to reduce the 2101 Flash memory footprint) 2102 2103- it becomes much easier to port new Linux kernel versions because 2104 lots of low-level, hardware dependend stuff are done by U-Boot 2105 2106- the same Linux kernel image can now be used with different "initrd" 2107 images; of course this also means that different kernel images can 2108 be run with the same "initrd". This makes testing easier (you don't 2109 have to build a new "zImage.initrd" Linux image when you just 2110 change a file in your "initrd"). Also, a field-upgrade of the 2111 software is easier now. 2112 2113 2114Linux HOWTO: 2115============ 2116 2117Porting Linux to U-Boot based systems: 2118--------------------------------------- 2119 2120U-Boot cannot save you from doing all the necessary modifications to 2121configure the Linux device drivers for use with your target hardware 2122(no, we don't intend to provide a full virtual machine interface to 2123Linux :-). 2124 2125But now you can ignore ALL boot loader code (in arch/ppc/mbxboot). 2126 2127Just make sure your machine specific header file (for instance 2128include/asm-ppc/tqm8xx.h) includes the same definition of the Board 2129Information structure as we define in include/u-boot.h, and make 2130sure that your definition of IMAP_ADDR uses the same value as your 2131U-Boot configuration in CFG_IMMR. 2132 2133 2134Configuring the Linux kernel: 2135----------------------------- 2136 2137No specific requirements for U-Boot. Make sure you have some root 2138device (initial ramdisk, NFS) for your target system. 2139 2140 2141Building a Linux Image: 2142----------------------- 2143 2144With U-Boot, "normal" build targets like "zImage" or "bzImage" are 2145not used. If you use recent kernel source, a new build target 2146"uImage" will exist which automatically builds an image usable by 2147U-Boot. Most older kernels also have support for a "pImage" target, 2148which was introduced for our predecessor project PPCBoot and uses a 2149100% compatible format. 2150 2151Example: 2152 2153 make TQM850L_config 2154 make oldconfig 2155 make dep 2156 make uImage 2157 2158The "uImage" build target uses a special tool (in 'tools/mkimage') to 2159encapsulate a compressed Linux kernel image with header information, 2160CRC32 checksum etc. for use with U-Boot. This is what we are doing: 2161 2162* build a standard "vmlinux" kernel image (in ELF binary format): 2163 2164* convert the kernel into a raw binary image: 2165 2166 ${CROSS_COMPILE}-objcopy -O binary \ 2167 -R .note -R .comment \ 2168 -S vmlinux linux.bin 2169 2170* compress the binary image: 2171 2172 gzip -9 linux.bin 2173 2174* package compressed binary image for U-Boot: 2175 2176 mkimage -A ppc -O linux -T kernel -C gzip \ 2177 -a 0 -e 0 -n "Linux Kernel Image" \ 2178 -d linux.bin.gz uImage 2179 2180 2181The "mkimage" tool can also be used to create ramdisk images for use 2182with U-Boot, either separated from the Linux kernel image, or 2183combined into one file. "mkimage" encapsulates the images with a 64 2184byte header containing information about target architecture, 2185operating system, image type, compression method, entry points, time 2186stamp, CRC32 checksums, etc. 2187 2188"mkimage" can be called in two ways: to verify existing images and 2189print the header information, or to build new images. 2190 2191In the first form (with "-l" option) mkimage lists the information 2192contained in the header of an existing U-Boot image; this includes 2193checksum verification: 2194 2195 tools/mkimage -l image 2196 -l ==> list image header information 2197 2198The second form (with "-d" option) is used to build a U-Boot image 2199from a "data file" which is used as image payload: 2200 2201 tools/mkimage -A arch -O os -T type -C comp -a addr -e ep \ 2202 -n name -d data_file image 2203 -A ==> set architecture to 'arch' 2204 -O ==> set operating system to 'os' 2205 -T ==> set image type to 'type' 2206 -C ==> set compression type 'comp' 2207 -a ==> set load address to 'addr' (hex) 2208 -e ==> set entry point to 'ep' (hex) 2209 -n ==> set image name to 'name' 2210 -d ==> use image data from 'datafile' 2211 2212Right now, all Linux kernels use the same load address (0x00000000), 2213but the entry point address depends on the kernel version: 2214 2215- 2.2.x kernels have the entry point at 0x0000000C, 2216- 2.3.x and later kernels have the entry point at 0x00000000. 2217 2218So a typical call to build a U-Boot image would read: 2219 2220 -> tools/mkimage -n '2.4.4 kernel for TQM850L' \ 2221 > -A ppc -O linux -T kernel -C gzip -a 0 -e 0 \ 2222 > -d /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/ppc/coffboot/vmlinux.gz \ 2223 > examples/uImage.TQM850L 2224 Image Name: 2.4.4 kernel for TQM850L 2225 Created: Wed Jul 19 02:34:59 2000 2226 Image Type: PowerPC Linux Kernel Image (gzip compressed) 2227 Data Size: 335725 Bytes = 327.86 kB = 0.32 MB 2228 Load Address: 0x00000000 2229 Entry Point: 0x00000000 2230 2231To verify the contents of the image (or check for corruption): 2232 2233 -> tools/mkimage -l examples/uImage.TQM850L 2234 Image Name: 2.4.4 kernel for TQM850L 2235 Created: Wed Jul 19 02:34:59 2000 2236 Image Type: PowerPC Linux Kernel Image (gzip compressed) 2237 Data Size: 335725 Bytes = 327.86 kB = 0.32 MB 2238 Load Address: 0x00000000 2239 Entry Point: 0x00000000 2240 2241NOTE: for embedded systems where boot time is critical you can trade 2242speed for memory and install an UNCOMPRESSED image instead: this 2243needs more space in Flash, but boots much faster since it does not 2244need to be uncompressed: 2245 2246 -> gunzip /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/ppc/coffboot/vmlinux.gz 2247 -> tools/mkimage -n '2.4.4 kernel for TQM850L' \ 2248 > -A ppc -O linux -T kernel -C none -a 0 -e 0 \ 2249 > -d /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/ppc/coffboot/vmlinux \ 2250 > examples/uImage.TQM850L-uncompressed 2251 Image Name: 2.4.4 kernel for TQM850L 2252 Created: Wed Jul 19 02:34:59 2000 2253 Image Type: PowerPC Linux Kernel Image (uncompressed) 2254 Data Size: 792160 Bytes = 773.59 kB = 0.76 MB 2255 Load Address: 0x00000000 2256 Entry Point: 0x00000000 2257 2258 2259Similar you can build U-Boot images from a 'ramdisk.image.gz' file 2260when your kernel is intended to use an initial ramdisk: 2261 2262 -> tools/mkimage -n 'Simple Ramdisk Image' \ 2263 > -A ppc -O linux -T ramdisk -C gzip \ 2264 > -d /LinuxPPC/images/SIMPLE-ramdisk.image.gz examples/simple-initrd 2265 Image Name: Simple Ramdisk Image 2266 Created: Wed Jan 12 14:01:50 2000 2267 Image Type: PowerPC Linux RAMDisk Image (gzip compressed) 2268 Data Size: 566530 Bytes = 553.25 kB = 0.54 MB 2269 Load Address: 0x00000000 2270 Entry Point: 0x00000000 2271 2272 2273Installing a Linux Image: 2274------------------------- 2275 2276To downloading a U-Boot image over the serial (console) interface, 2277you must convert the image to S-Record format: 2278 2279 objcopy -I binary -O srec examples/image examples/image.srec 2280 2281The 'objcopy' does not understand the information in the U-Boot 2282image header, so the resulting S-Record file will be relative to 2283address 0x00000000. To load it to a given address, you need to 2284specify the target address as 'offset' parameter with the 'loads' 2285command. 2286 2287Example: install the image to address 0x40100000 (which on the 2288TQM8xxL is in the first Flash bank): 2289 2290 => erase 40100000 401FFFFF 2291 2292 .......... done 2293 Erased 8 sectors 2294 2295 => loads 40100000 2296 ## Ready for S-Record download ... 2297 ~>examples/image.srec 2298 1 2 3 4 5 6 7 8 9 10 11 12 13 ... 2299 ... 2300 15989 15990 15991 15992 2301 [file transfer complete] 2302 [connected] 2303 ## Start Addr = 0x00000000 2304 2305 2306You can check the success of the download using the 'iminfo' command; 2307this includes a checksum verification so you can be sure no data 2308corruption happened: 2309 2310 => imi 40100000 2311 2312 ## Checking Image at 40100000 ... 2313 Image Name: 2.2.13 for initrd on TQM850L 2314 Image Type: PowerPC Linux Kernel Image (gzip compressed) 2315 Data Size: 335725 Bytes = 327 kB = 0 MB 2316 Load Address: 00000000 2317 Entry Point: 0000000c 2318 Verifying Checksum ... OK 2319 2320 2321 2322Boot Linux: 2323----------- 2324 2325The "bootm" command is used to boot an application that is stored in 2326memory (RAM or Flash). In case of a Linux kernel image, the contents 2327of the "bootargs" environment variable is passed to the kernel as 2328parameters. You can check and modify this variable using the 2329"printenv" and "setenv" commands: 2330 2331 2332 => printenv bootargs 2333 bootargs=root=/dev/ram 2334 2335 => setenv bootargs root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2 2336 2337 => printenv bootargs 2338 bootargs=root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2 2339 2340 => bootm 40020000 2341 ## Booting Linux kernel at 40020000 ... 2342 Image Name: 2.2.13 for NFS on TQM850L 2343 Image Type: PowerPC Linux Kernel Image (gzip compressed) 2344 Data Size: 381681 Bytes = 372 kB = 0 MB 2345 Load Address: 00000000 2346 Entry Point: 0000000c 2347 Verifying Checksum ... OK 2348 Uncompressing Kernel Image ... OK 2349 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 2350 Boot arguments: root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2 2351 time_init: decrementer frequency = 187500000/60 2352 Calibrating delay loop... 49.77 BogoMIPS 2353 Memory: 15208k available (700k kernel code, 444k data, 32k init) [c0000000,c1000000] 2354 ... 2355 2356If you want to boot a Linux kernel with initial ram disk, you pass 2357the memory addreses of both the kernel and the initrd image (PPBCOOT 2358format!) to the "bootm" command: 2359 2360 => imi 40100000 40200000 2361 2362 ## Checking Image at 40100000 ... 2363 Image Name: 2.2.13 for initrd on TQM850L 2364 Image Type: PowerPC Linux Kernel Image (gzip compressed) 2365 Data Size: 335725 Bytes = 327 kB = 0 MB 2366 Load Address: 00000000 2367 Entry Point: 0000000c 2368 Verifying Checksum ... OK 2369 2370 ## Checking Image at 40200000 ... 2371 Image Name: Simple Ramdisk Image 2372 Image Type: PowerPC Linux RAMDisk Image (gzip compressed) 2373 Data Size: 566530 Bytes = 553 kB = 0 MB 2374 Load Address: 00000000 2375 Entry Point: 00000000 2376 Verifying Checksum ... OK 2377 2378 => bootm 40100000 40200000 2379 ## Booting Linux kernel at 40100000 ... 2380 Image Name: 2.2.13 for initrd on TQM850L 2381 Image Type: PowerPC Linux Kernel Image (gzip compressed) 2382 Data Size: 335725 Bytes = 327 kB = 0 MB 2383 Load Address: 00000000 2384 Entry Point: 0000000c 2385 Verifying Checksum ... OK 2386 Uncompressing Kernel Image ... OK 2387 ## Loading RAMDisk Image at 40200000 ... 2388 Image Name: Simple Ramdisk Image 2389 Image Type: PowerPC Linux RAMDisk Image (gzip compressed) 2390 Data Size: 566530 Bytes = 553 kB = 0 MB 2391 Load Address: 00000000 2392 Entry Point: 00000000 2393 Verifying Checksum ... OK 2394 Loading Ramdisk ... OK 2395 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 2396 Boot arguments: root=/dev/ram 2397 time_init: decrementer frequency = 187500000/60 2398 Calibrating delay loop... 49.77 BogoMIPS 2399 ... 2400 RAMDISK: Compressed image found at block 0 2401 VFS: Mounted root (ext2 filesystem). 2402 2403 bash# 2404 2405More About U-Boot Image Types: 2406------------------------------ 2407 2408U-Boot supports the following image types: 2409 2410 "Standalone Programs" are directly runnable in the environment 2411 provided by U-Boot; it is expected that (if they behave 2412 well) you can continue to work in U-Boot after return from 2413 the Standalone Program. 2414 "OS Kernel Images" are usually images of some Embedded OS which 2415 will take over control completely. Usually these programs 2416 will install their own set of exception handlers, device 2417 drivers, set up the MMU, etc. - this means, that you cannot 2418 expect to re-enter U-Boot except by resetting the CPU. 2419 "RAMDisk Images" are more or less just data blocks, and their 2420 parameters (address, size) are passed to an OS kernel that is 2421 being started. 2422 "Multi-File Images" contain several images, typically an OS 2423 (Linux) kernel image and one or more data images like 2424 RAMDisks. This construct is useful for instance when you want 2425 to boot over the network using BOOTP etc., where the boot 2426 server provides just a single image file, but you want to get 2427 for instance an OS kernel and a RAMDisk image. 2428 2429 "Multi-File Images" start with a list of image sizes, each 2430 image size (in bytes) specified by an "uint32_t" in network 2431 byte order. This list is terminated by an "(uint32_t)0". 2432 Immediately after the terminating 0 follow the images, one by 2433 one, all aligned on "uint32_t" boundaries (size rounded up to 2434 a multiple of 4 bytes). 2435 2436 "Firmware Images" are binary images containing firmware (like 2437 U-Boot or FPGA images) which usually will be programmed to 2438 flash memory. 2439 2440 "Script files" are command sequences that will be executed by 2441 U-Boot's command interpreter; this feature is especially 2442 useful when you configure U-Boot to use a real shell (hush) 2443 as command interpreter. 2444 2445 2446Standalone HOWTO: 2447================= 2448 2449One of the features of U-Boot is that you can dynamically load and 2450run "standalone" applications, which can use some resources of 2451U-Boot like console I/O functions or interrupt services. 2452 2453Two simple examples are included with the sources: 2454 2455"Hello World" Demo: 2456------------------- 2457 2458'examples/hello_world.c' contains a small "Hello World" Demo 2459application; it is automatically compiled when you build U-Boot. 2460It's configured to run at address 0x00040004, so you can play with it 2461like that: 2462 2463 => loads 2464 ## Ready for S-Record download ... 2465 ~>examples/hello_world.srec 2466 1 2 3 4 5 6 7 8 9 10 11 ... 2467 [file transfer complete] 2468 [connected] 2469 ## Start Addr = 0x00040004 2470 2471 => go 40004 Hello World! This is a test. 2472 ## Starting application at 0x00040004 ... 2473 Hello World 2474 argc = 7 2475 argv[0] = "40004" 2476 argv[1] = "Hello" 2477 argv[2] = "World!" 2478 argv[3] = "This" 2479 argv[4] = "is" 2480 argv[5] = "a" 2481 argv[6] = "test." 2482 argv[7] = "<NULL>" 2483 Hit any key to exit ... 2484 2485 ## Application terminated, rc = 0x0 2486 2487Another example, which demonstrates how to register a CPM interrupt 2488handler with the U-Boot code, can be found in 'examples/timer.c'. 2489Here, a CPM timer is set up to generate an interrupt every second. 2490The interrupt service routine is trivial, just printing a '.' 2491character, but this is just a demo program. The application can be 2492controlled by the following keys: 2493 2494 ? - print current values og the CPM Timer registers 2495 b - enable interrupts and start timer 2496 e - stop timer and disable interrupts 2497 q - quit application 2498 2499 => loads 2500 ## Ready for S-Record download ... 2501 ~>examples/timer.srec 2502 1 2 3 4 5 6 7 8 9 10 11 ... 2503 [file transfer complete] 2504 [connected] 2505 ## Start Addr = 0x00040004 2506 2507 => go 40004 2508 ## Starting application at 0x00040004 ... 2509 TIMERS=0xfff00980 2510 Using timer 1 2511 tgcr @ 0xfff00980, tmr @ 0xfff00990, trr @ 0xfff00994, tcr @ 0xfff00998, tcn @ 0xfff0099c, ter @ 0xfff009b0 2512 2513Hit 'b': 2514 [q, b, e, ?] Set interval 1000000 us 2515 Enabling timer 2516Hit '?': 2517 [q, b, e, ?] ........ 2518 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0xef6, ter=0x0 2519Hit '?': 2520 [q, b, e, ?] . 2521 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x2ad4, ter=0x0 2522Hit '?': 2523 [q, b, e, ?] . 2524 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x1efc, ter=0x0 2525Hit '?': 2526 [q, b, e, ?] . 2527 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x169d, ter=0x0 2528Hit 'e': 2529 [q, b, e, ?] ...Stopping timer 2530Hit 'q': 2531 [q, b, e, ?] ## Application terminated, rc = 0x0 2532 2533 2534 2535Minicom warning: 2536================ 2537 2538Over time, many people have reported problems when trying to used the 2539"minicom" terminal emulation program for serial download. I (wd) 2540consider minicom to be broken, and recommend not to use it. Under 2541Unix, I recommend to use CKermit for general purpose use (and 2542especially for kermit binary protocol download ("loadb" command), and 2543use "cu" for S-Record download ("loads" command). 2544 2545NetBSD Notes: 2546============= 2547 2548Starting at version 0.9.2, U-Boot supports NetBSD both as host 2549(build U-Boot) and target system (boots NetBSD/mpc8xx). 2550 2551Building requires a cross environment; it is known to work on 2552NetBSD/i386 with the cross-powerpc-netbsd-1.3 package (you will also 2553need gmake since the Makefiles are not compatible with BSD make). 2554Note that the cross-powerpc package does not install include files; 2555attempting to build U-Boot will fail because <machine/ansi.h> is 2556missing. This file has to be installed and patched manually: 2557 2558 # cd /usr/pkg/cross/powerpc-netbsd/include 2559 # mkdir powerpc 2560 # ln -s powerpc machine 2561 # cp /usr/src/sys/arch/powerpc/include/ansi.h powerpc/ansi.h 2562 # ${EDIT} powerpc/ansi.h ## must remove __va_list, _BSD_VA_LIST 2563 2564Native builds *don't* work due to incompatibilities between native 2565and U-Boot include files. 2566 2567Booting assumes that (the first part of) the image booted is a 2568stage-2 loader which in turn loads and then invokes the kernel 2569proper. Loader sources will eventually appear in the NetBSD source 2570tree (probably in sys/arc/mpc8xx/stand/u-boot_stage2/); in the 2571meantime, send mail to bruno@exet-ag.de and/or wd@denx.de for 2572details. 2573 2574 2575Implementation Internals: 2576========================= 2577 2578The following is not intended to be a complete description of every 2579implementation detail. However, it should help to understand the 2580inner workings of U-Boot and make it easier to port it to custom 2581hardware. 2582 2583 2584Initial Stack, Global Data: 2585--------------------------- 2586 2587The implementation of U-Boot is complicated by the fact that U-Boot 2588starts running out of ROM (flash memory), usually without access to 2589system RAM (because the memory controller is not initialized yet). 2590This means that we don't have writable Data or BSS segments, and BSS 2591is not initialized as zero. To be able to get a C environment working 2592at all, we have to allocate at least a minimal stack. Implementation 2593options for this are defined and restricted by the CPU used: Some CPU 2594models provide on-chip memory (like the IMMR area on MPC8xx and 2595MPC826x processors), on others (parts of) the data cache can be 2596locked as (mis-) used as memory, etc. 2597 2598 Chris Hallinan posted a good summy of these issues to the 2599 u-boot-users mailing list: 2600 2601 Subject: RE: [U-Boot-Users] RE: More On Memory Bank x (nothingness)? 2602 From: "Chris Hallinan" <clh@net1plus.com> 2603 Date: Mon, 10 Feb 2003 16:43:46 -0500 (22:43 MET) 2604 ... 2605 2606 Correct me if I'm wrong, folks, but the way I understand it 2607 is this: Using DCACHE as initial RAM for Stack, etc, does not 2608 require any physical RAM backing up the cache. The cleverness 2609 is that the cache is being used as a temporary supply of 2610 necessary storage before the SDRAM controller is setup. It's 2611 beyond the scope of this list to expain the details, but you 2612 can see how this works by studying the cache architecture and 2613 operation in the architecture and processor-specific manuals. 2614 2615 OCM is On Chip Memory, which I believe the 405GP has 4K. It 2616 is another option for the system designer to use as an 2617 initial stack/ram area prior to SDRAM being available. Either 2618 option should work for you. Using CS 4 should be fine if your 2619 board designers haven't used it for something that would 2620 cause you grief during the initial boot! It is frequently not 2621 used. 2622 2623 CFG_INIT_RAM_ADDR should be somewhere that won't interfere 2624 with your processor/board/system design. The default value 2625 you will find in any recent u-boot distribution in 2626 Walnut405.h should work for you. I'd set it to a value larger 2627 than your SDRAM module. If you have a 64MB SDRAM module, set 2628 it above 400_0000. Just make sure your board has no resources 2629 that are supposed to respond to that address! That code in 2630 start.S has been around a while and should work as is when 2631 you get the config right. 2632 2633 -Chris Hallinan 2634 DS4.COM, Inc. 2635 2636It is essential to remember this, since it has some impact on the C 2637code for the initialization procedures: 2638 2639* Initialized global data (data segment) is read-only. Do not attempt 2640 to write it. 2641 2642* Do not use any unitialized global data (or implicitely initialized 2643 as zero data - BSS segment) at all - this is undefined, initiali- 2644 zation is performed later (when relocationg to RAM). 2645 2646* Stack space is very limited. Avoid big data buffers or things like 2647 that. 2648 2649Having only the stack as writable memory limits means we cannot use 2650normal global data to share information beween the code. But it 2651turned out that the implementation of U-Boot can be greatly 2652simplified by making a global data structure (gd_t) available to all 2653functions. We could pass a pointer to this data as argument to _all_ 2654functions, but this would bloat the code. Instead we use a feature of 2655the GCC compiler (Global Register Variables) to share the data: we 2656place a pointer (gd) to the global data into a register which we 2657reserve for this purpose. 2658 2659When chosing a register for such a purpose we are restricted by the 2660relevant (E)ABI specifications for the current architecture, and by 2661GCC's implementation. 2662 2663For PowerPC, the following registers have specific use: 2664 R1: stack pointer 2665 R2: TOC pointer 2666 R3-R4: parameter passing and return values 2667 R5-R10: parameter passing 2668 R13: small data area pointer 2669 R30: GOT pointer 2670 R31: frame pointer 2671 2672 (U-Boot also uses R14 as internal GOT pointer.) 2673 2674 ==> U-Boot will use R29 to hold a pointer to the global data 2675 2676 Note: on PPC, we could use a static initializer (since the 2677 address of the global data structure is known at compile time), 2678 but it turned out that reserving a register results in somewhat 2679 smaller code - although the code savings are not that big (on 2680 average for all boards 752 bytes for the whole U-Boot image, 2681 624 text + 127 data). 2682 2683On ARM, the following registers are used: 2684 2685 R0: function argument word/integer result 2686 R1-R3: function argument word 2687 R9: GOT pointer 2688 R10: stack limit (used only if stack checking if enabled) 2689 R11: argument (frame) pointer 2690 R12: temporary workspace 2691 R13: stack pointer 2692 R14: link register 2693 R15: program counter 2694 2695 ==> U-Boot will use R8 to hold a pointer to the global data 2696 2697 2698 2699Memory Management: 2700------------------ 2701 2702U-Boot runs in system state and uses physical addresses, i.e. the 2703MMU is not used either for address mapping nor for memory protection. 2704 2705The available memory is mapped to fixed addresses using the memory 2706controller. In this process, a contiguous block is formed for each 2707memory type (Flash, SDRAM, SRAM), even when it consists of several 2708physical memory banks. 2709 2710U-Boot is installed in the first 128 kB of the first Flash bank (on 2711TQM8xxL modules this is the range 0x40000000 ... 0x4001FFFF). After 2712booting and sizing and initializing DRAM, the code relocates itself 2713to the upper end of DRAM. Immediately below the U-Boot code some 2714memory is reserved for use by malloc() [see CFG_MALLOC_LEN 2715configuration setting]. Below that, a structure with global Board 2716Info data is placed, followed by the stack (growing downward). 2717 2718Additionally, some exception handler code is copied to the low 8 kB 2719of DRAM (0x00000000 ... 0x00001FFF). 2720 2721So a typical memory configuration with 16 MB of DRAM could look like 2722this: 2723 2724 0x0000 0000 Exception Vector code 2725 : 2726 0x0000 1FFF 2727 0x0000 2000 Free for Application Use 2728 : 2729 : 2730 2731 : 2732 : 2733 0x00FB FF20 Monitor Stack (Growing downward) 2734 0x00FB FFAC Board Info Data and permanent copy of global data 2735 0x00FC 0000 Malloc Arena 2736 : 2737 0x00FD FFFF 2738 0x00FE 0000 RAM Copy of Monitor Code 2739 ... eventually: LCD or video framebuffer 2740 ... eventually: pRAM (Protected RAM - unchanged by reset) 2741 0x00FF FFFF [End of RAM] 2742 2743 2744System Initialization: 2745---------------------- 2746 2747In the reset configuration, U-Boot starts at the reset entry point 2748(on most PowerPC systens at address 0x00000100). Because of the reset 2749configuration for CS0# this is a mirror of the onboard Flash memory. 2750To be able to re-map memory U-Boot then jumps to it's link address. 2751To be able to implement the initialization code in C, a (small!) 2752initial stack is set up in the internal Dual Ported RAM (in case CPUs 2753which provide such a feature like MPC8xx or MPC8260), or in a locked 2754part of the data cache. After that, U-Boot initializes the CPU core, 2755the caches and the SIU. 2756 2757Next, all (potentially) available memory banks are mapped using a 2758preliminary mapping. For example, we put them on 512 MB boundaries 2759(multiples of 0x20000000: SDRAM on 0x00000000 and 0x20000000, Flash 2760on 0x40000000 and 0x60000000, SRAM on 0x80000000). Then UPM A is 2761programmed for SDRAM access. Using the temporary configuration, a 2762simple memory test is run that determines the size of the SDRAM 2763banks. 2764 2765When there is more than one SDRAM bank, and the banks are of 2766different size, the larger is mapped first. For equal size, the first 2767bank (CS2#) is mapped first. The first mapping is always for address 27680x00000000, with any additional banks following immediately to create 2769contiguous memory starting from 0. 2770 2771Then, the monitor installs itself at the upper end of the SDRAM area 2772and allocates memory for use by malloc() and for the global Board 2773Info data; also, the exception vector code is copied to the low RAM 2774pages, and the final stack is set up. 2775 2776Only after this relocation will you have a "normal" C environment; 2777until that you are restricted in several ways, mostly because you are 2778running from ROM, and because the code will have to be relocated to a 2779new address in RAM. 2780 2781 2782U-Boot Porting Guide: 2783---------------------- 2784 2785[Based on messages by Jerry Van Baren in the U-Boot-Users mailing 2786list, October 2002] 2787 2788 2789int main (int argc, char *argv[]) 2790{ 2791 sighandler_t no_more_time; 2792 2793 signal (SIGALRM, no_more_time); 2794 alarm (PROJECT_DEADLINE - toSec (3 * WEEK)); 2795 2796 if (available_money > available_manpower) { 2797 pay consultant to port U-Boot; 2798 return 0; 2799 } 2800 2801 Download latest U-Boot source; 2802 2803 Subscribe to u-boot-users mailing list; 2804 2805 if (clueless) { 2806 email ("Hi, I am new to U-Boot, how do I get started?"); 2807 } 2808 2809 while (learning) { 2810 Read the README file in the top level directory; 2811 Read http://www.denx.de/re/DPLG.html 2812 Read the source, Luke; 2813 } 2814 2815 if (available_money > toLocalCurrency ($2500)) { 2816 Buy a BDI2000; 2817 } else { 2818 Add a lot of aggravation and time; 2819 } 2820 2821 Create your own board support subdirectory; 2822 2823 Create your own board config file; 2824 2825 while (!running) { 2826 do { 2827 Add / modify source code; 2828 } until (compiles); 2829 Debug; 2830 if (clueless) 2831 email ("Hi, I am having problems..."); 2832 } 2833 Send patch file to Wolfgang; 2834 2835 return 0; 2836} 2837 2838void no_more_time (int sig) 2839{ 2840 hire_a_guru(); 2841} 2842 2843 2844 2845Coding Standards: 2846----------------- 2847 2848All contributions to U-Boot should conform to the Linux kernel 2849coding style; see the file "Documentation/CodingStyle" in your Linux 2850kernel source directory. 2851 2852Please note that U-Boot is implemented in C (and to some small parts 2853in Assembler); no C++ is used, so please do not use C++ style 2854comments (//) in your code. 2855 2856Submissions which do not conform to the standards may be returned 2857with a request to reformat the changes. 2858 2859 2860Submitting Patches: 2861------------------- 2862 2863Since the number of patches for U-Boot is growing, we need to 2864establish some rules. Submissions which do not conform to these rules 2865may be rejected, even when they contain important and valuable stuff. 2866 2867 2868When you send a patch, please include the following information with 2869it: 2870 2871* For bug fixes: a description of the bug and how your patch fixes 2872 this bug. Please try to include a way of demonstrating that the 2873 patch actually fixes something. 2874 2875* For new features: a description of the feature and your 2876 implementation. 2877 2878* A CHANGELOG entry as plaintext (separate from the patch) 2879 2880* For major contributions, your entry to the CREDITS file 2881 2882* When you add support for a new board, don't forget to add this 2883 board to the MAKEALL script, too. 2884 2885* If your patch adds new configuration options, don't forget to 2886 document these in the README file. 2887 2888* The patch itself. If you are accessing the CVS repository use "cvs 2889 update; cvs diff -puRN"; else, use "diff -purN OLD NEW". If your 2890 version of diff does not support these options, then get the latest 2891 version of GNU diff. 2892 2893 We accept patches as plain text, MIME attachments or as uuencoded 2894 gzipped text. 2895 2896Notes: 2897 2898* Before sending the patch, run the MAKEALL script on your patched 2899 source tree and make sure that no errors or warnings are reported 2900 for any of the boards. 2901 2902* Keep your modifications to the necessary minimum: A patch 2903 containing several unrelated changes or arbitrary reformats will be 2904 returned with a request to re-formatting / split it. 2905 2906* If you modify existing code, make sure that your new code does not 2907 add to the memory footprint of the code ;-) Small is beautiful! 2908 When adding new features, these should compile conditionally only 2909 (using #ifdef), and the resulting code with the new feature 2910 disabled must not need more memory than the old code without your 2911 modification. 2912