1# 2# (C) Copyright 2000 - 2004 3# Wolfgang Denk, DENX Software Engineering, wd@denx.de. 4# 5# See file CREDITS for list of people who contributed to this 6# project. 7# 8# This program is free software; you can redistribute it and/or 9# modify it under the terms of the GNU General Public License as 10# published by the Free Software Foundation; either version 2 of 11# the License, or (at your option) any later version. 12# 13# This program is distributed in the hope that it will be useful, 14# but WITHOUT ANY WARRANTY; without even the implied warranty of 15# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 16# GNU General Public License for more details. 17# 18# You should have received a copy of the GNU General Public License 19# along with this program; if not, write to the Free Software 20# Foundation, Inc., 59 Temple Place, Suite 330, Boston, 21# MA 02111-1307 USA 22# 23 24Summary: 25======== 26 27This directory contains the source code for U-Boot, a boot loader for 28Embedded boards based on PowerPC and ARM processors, which can be 29installed in a boot ROM and used to initialize and test the hardware 30or to download and run application code. 31 32The development of U-Boot is closely related to Linux: some parts of 33the source code originate in the Linux source tree, we have some 34header files in common, and special provision has been made to 35support booting of Linux images. 36 37Some attention has been paid to make this software easily 38configurable and extendable. For instance, all monitor commands are 39implemented with the same call interface, so that it's very easy to 40add new commands. Also, instead of permanently adding rarely used 41code (for instance hardware test utilities) to the monitor, you can 42load and run it dynamically. 43 44 45Status: 46======= 47 48In general, all boards for which a configuration option exists in the 49Makefile have been tested to some extent and can be considered 50"working". In fact, many of them are used in production systems. 51 52In case of problems see the CHANGELOG and CREDITS files to find out 53who contributed the specific port. 54 55 56Where to get help: 57================== 58 59In case you have questions about, problems with or contributions for 60U-Boot you should send a message to the U-Boot mailing list at 61<u-boot-users@lists.sourceforge.net>. There is also an archive of 62previous traffic on the mailing list - please search the archive 63before asking FAQ's. Please see 64http://lists.sourceforge.net/lists/listinfo/u-boot-users/ 65 66 67Where we come from: 68=================== 69 70- start from 8xxrom sources 71- create PPCBoot project (http://sourceforge.net/projects/ppcboot) 72- clean up code 73- make it easier to add custom boards 74- make it possible to add other [PowerPC] CPUs 75- extend functions, especially: 76 * Provide extended interface to Linux boot loader 77 * S-Record download 78 * network boot 79 * PCMCIA / CompactFLash / ATA disk / SCSI ... boot 80- create ARMBoot project (http://sourceforge.net/projects/armboot) 81- add other CPU families (starting with ARM) 82- create U-Boot project (http://sourceforge.net/projects/u-boot) 83 84 85Names and Spelling: 86=================== 87 88The "official" name of this project is "Das U-Boot". The spelling 89"U-Boot" shall be used in all written text (documentation, comments 90in source files etc.). Example: 91 92 This is the README file for the U-Boot project. 93 94File names etc. shall be based on the string "u-boot". Examples: 95 96 include/asm-ppc/u-boot.h 97 98 #include <asm/u-boot.h> 99 100Variable names, preprocessor constants etc. shall be either based on 101the string "u_boot" or on "U_BOOT". Example: 102 103 U_BOOT_VERSION u_boot_logo 104 IH_OS_U_BOOT u_boot_hush_start 105 106 107Versioning: 108=========== 109 110U-Boot uses a 3 level version number containing a version, a 111sub-version, and a patchlevel: "U-Boot-2.34.5" means version "2", 112sub-version "34", and patchlevel "4". 113 114The patchlevel is used to indicate certain stages of development 115between released versions, i. e. officially released versions of 116U-Boot will always have a patchlevel of "0". 117 118 119Directory Hierarchy: 120==================== 121 122- board Board dependent files 123- common Misc architecture independent functions 124- cpu CPU specific files 125- disk Code for disk drive partition handling 126- doc Documentation (don't expect too much) 127- drivers Commonly used device drivers 128- dtt Digital Thermometer and Thermostat drivers 129- examples Example code for standalone applications, etc. 130- include Header Files 131- disk Harddisk interface code 132- net Networking code 133- ppc Files generic to PowerPC architecture 134- post Power On Self Test 135- post/arch Symlink to architecture specific Power On Self Test 136- post/arch-ppc PowerPC architecture specific Power On Self Test 137- post/cpu/mpc8260 MPC8260 CPU specific Power On Self Test 138- post/cpu/mpc8xx MPC8xx CPU specific Power On Self Test 139- rtc Real Time Clock drivers 140- tools Tools to build S-Record or U-Boot images, etc. 141 142- cpu/74xx_7xx Files specific to Motorola MPC74xx and 7xx CPUs 143- cpu/arm925t Files specific to ARM 925 CPUs 144- cpu/arm926ejs Files specific to ARM 926 CPUs 145- cpu/mpc5xx Files specific to Motorola MPC5xx CPUs 146- cpu/mpc8xx Files specific to Motorola MPC8xx CPUs 147- cpu/mpc824x Files specific to Motorola MPC824x CPUs 148- cpu/mpc8260 Files specific to Motorola MPC8260 CPU 149- cpu/mpc85xx Files specific to Motorola MPC85xx CPUs 150- cpu/ppc4xx Files specific to IBM 4xx CPUs 151 152 153- board/LEOX/ Files specific to boards manufactured by The LEOX team 154- board/LEOX/elpt860 Files specific to ELPT860 boards 155- board/RPXClassic 156 Files specific to RPXClassic boards 157- board/RPXlite Files specific to RPXlite boards 158- board/at91rm9200dk Files specific to AT91RM9200DK boards 159- board/c2mon Files specific to c2mon boards 160- board/cmi Files specific to cmi boards 161- board/cogent Files specific to Cogent boards 162 (need further configuration) 163 Files specific to CPCIISER4 boards 164- board/cpu86 Files specific to CPU86 boards 165- board/cray/ Files specific to boards manufactured by Cray 166- board/cray/L1 Files specific to L1 boards 167- board/cu824 Files specific to CU824 boards 168- board/ebony Files specific to IBM Ebony board 169- board/eric Files specific to ERIC boards 170- board/esd/ Files specific to boards manufactured by ESD 171- board/esd/adciop Files specific to ADCIOP boards 172- board/esd/ar405 Files specific to AR405 boards 173- board/esd/canbt Files specific to CANBT boards 174- board/esd/cpci405 Files specific to CPCI405 boards 175- board/esd/cpciiser4 Files specific to CPCIISER4 boards 176- board/esd/common Common files for ESD boards 177- board/esd/dasa_sim Files specific to DASA_SIM boards 178- board/esd/du405 Files specific to DU405 boards 179- board/esd/ocrtc Files specific to OCRTC boards 180- board/esd/pci405 Files specific to PCI405 boards 181- board/esteem192e 182 Files specific to ESTEEM192E boards 183- board/etx094 Files specific to ETX_094 boards 184- board/evb64260 185 Files specific to EVB64260 boards 186- board/fads Files specific to FADS boards 187- board/flagadm Files specific to FLAGADM boards 188- board/gen860t Files specific to GEN860T and GEN860T_SC boards 189- board/genietv Files specific to GENIETV boards 190- board/gth Files specific to GTH boards 191- board/hermes Files specific to HERMES boards 192- board/hymod Files specific to HYMOD boards 193- board/icu862 Files specific to ICU862 boards 194- board/ip860 Files specific to IP860 boards 195- board/iphase4539 196 Files specific to Interphase4539 boards 197- board/ivm Files specific to IVMS8/IVML24 boards 198- board/lantec Files specific to LANTEC boards 199- board/lwmon Files specific to LWMON boards 200- board/Marvell Files specific to Marvell development boards 201- board/Marvell/db64360 Files specific to db64360 board 202- board/Marvell/db64460 Files specific to db64460 board 203- board/mbx8xx Files specific to MBX boards 204- board/mpc8260ads 205 Files specific to MPC826xADS and PQ2FADS-ZU/VR boards 206- board/mpc8540ads 207 Files specific to MPC8540ADS boards 208- board/mpc8560ads 209 Files specific to MPC8560ADS boards 210- board/mpl/ Files specific to boards manufactured by MPL 211- board/mpl/common Common files for MPL boards 212- board/mpl/pip405 Files specific to PIP405 boards 213- board/mpl/mip405 Files specific to MIP405 boards 214- board/mpl/vcma9 Files specific to VCMA9 boards 215- board/musenki Files specific to MUSEKNI boards 216- board/mvs1 Files specific to MVS1 boards 217- board/nx823 Files specific to NX823 boards 218- board/oxc Files specific to OXC boards 219- board/omap1510inn 220 Files specific to OMAP 1510 Innovator boards 221- board/omap1610inn 222 Files specific to OMAP 1610 Innovator boards 223- board/pcippc2 Files specific to PCIPPC2/PCIPPC6 boards 224- board/pm826 Files specific to PM826 boards 225- board/ppmc8260 226 Files specific to PPMC8260 boards 227- board/snmc/qs850 Files specific to QS850/823 boards 228- board/snmc/qs860t Files specific to QS860T boards 229- board/rpxsuper 230 Files specific to RPXsuper boards 231- board/rsdproto 232 Files specific to RSDproto boards 233- board/sandpoint 234 Files specific to Sandpoint boards 235- board/sbc8260 Files specific to SBC8260 boards 236- board/sacsng Files specific to SACSng boards 237- board/siemens Files specific to boards manufactured by Siemens AG 238- board/siemens/CCM Files specific to CCM boards 239- board/siemens/IAD210 Files specific to IAD210 boards 240- board/siemens/SCM Files specific to SCM boards 241- board/siemens/pcu_e Files specific to PCU_E boards 242- board/sixnet Files specific to SIXNET boards 243- board/spd8xx Files specific to SPD8xxTS boards 244- board/tqm8260 Files specific to TQM8260 boards 245- board/tqm8xx Files specific to TQM8xxL boards 246- board/w7o Files specific to W7O boards 247- board/walnut405 248 Files specific to Walnut405 boards 249- board/westel/ Files specific to boards manufactured by Westel Wireless 250- board/westel/amx860 Files specific to AMX860 boards 251- board/utx8245 Files specific to UTX8245 boards 252- board/zpc1900 Files specific to Zephyr Engineering ZPC.1900 board 253 254Software Configuration: 255======================= 256 257Configuration is usually done using C preprocessor defines; the 258rationale behind that is to avoid dead code whenever possible. 259 260There are two classes of configuration variables: 261 262* Configuration _OPTIONS_: 263 These are selectable by the user and have names beginning with 264 "CONFIG_". 265 266* Configuration _SETTINGS_: 267 These depend on the hardware etc. and should not be meddled with if 268 you don't know what you're doing; they have names beginning with 269 "CFG_". 270 271Later we will add a configuration tool - probably similar to or even 272identical to what's used for the Linux kernel. Right now, we have to 273do the configuration by hand, which means creating some symbolic 274links and editing some configuration files. We use the TQM8xxL boards 275as an example here. 276 277 278Selection of Processor Architecture and Board Type: 279--------------------------------------------------- 280 281For all supported boards there are ready-to-use default 282configurations available; just type "make <board_name>_config". 283 284Example: For a TQM823L module type: 285 286 cd u-boot 287 make TQM823L_config 288 289For the Cogent platform, you need to specify the cpu type as well; 290e.g. "make cogent_mpc8xx_config". And also configure the cogent 291directory according to the instructions in cogent/README. 292 293 294Configuration Options: 295---------------------- 296 297Configuration depends on the combination of board and CPU type; all 298such information is kept in a configuration file 299"include/configs/<board_name>.h". 300 301Example: For a TQM823L module, all configuration settings are in 302"include/configs/TQM823L.h". 303 304 305Many of the options are named exactly as the corresponding Linux 306kernel configuration options. The intention is to make it easier to 307build a config tool - later. 308 309 310The following options need to be configured: 311 312- CPU Type: Define exactly one of 313 314 PowerPC based CPUs: 315 ------------------- 316 CONFIG_MPC823, CONFIG_MPC850, CONFIG_MPC855, CONFIG_MPC860 317 or CONFIG_MPC5xx 318 or CONFIG_MPC824X, CONFIG_MPC8260 319 or CONFIG_MPC85xx 320 or CONFIG_IOP480 321 or CONFIG_405GP 322 or CONFIG_405EP 323 or CONFIG_440 324 or CONFIG_MPC74xx 325 or CONFIG_750FX 326 327 ARM based CPUs: 328 --------------- 329 CONFIG_SA1110 330 CONFIG_ARM7 331 CONFIG_PXA250 332 333 334- Board Type: Define exactly one of 335 336 PowerPC based boards: 337 --------------------- 338 339 CONFIG_ADCIOP, CONFIG_ICU862 CONFIG_RPXsuper, 340 CONFIG_ADS860, CONFIG_IP860, CONFIG_SM850, 341 CONFIG_AMX860, CONFIG_IPHASE4539, CONFIG_SPD823TS, 342 CONFIG_AR405, CONFIG_IVML24, CONFIG_SXNI855T, 343 CONFIG_BAB7xx, CONFIG_IVML24_128, CONFIG_Sandpoint8240, 344 CONFIG_CANBT, CONFIG_IVML24_256, CONFIG_Sandpoint8245, 345 CONFIG_CCM, CONFIG_IVMS8, CONFIG_TQM823L, 346 CONFIG_CPCI405, CONFIG_IVMS8_128, CONFIG_TQM850L, 347 CONFIG_CPCI4052, CONFIG_IVMS8_256, CONFIG_TQM855L, 348 CONFIG_CPCIISER4, CONFIG_LANTEC, CONFIG_TQM860L, 349 CONFIG_CPU86, CONFIG_MBX, CONFIG_TQM8260, 350 CONFIG_CRAYL1, CONFIG_MBX860T, CONFIG_TTTech, 351 CONFIG_CU824, CONFIG_MHPC, CONFIG_UTX8245, 352 CONFIG_DASA_SIM, CONFIG_MIP405, CONFIG_W7OLMC, 353 CONFIG_DU405, CONFIG_MOUSSE, CONFIG_W7OLMG, 354 CONFIG_ELPPC, CONFIG_MPC8260ADS, CONFIG_WALNUT405, 355 CONFIG_ERIC, CONFIG_MUSENKI, CONFIG_ZUMA, 356 CONFIG_ESTEEM192E, CONFIG_MVS1, CONFIG_c2mon, 357 CONFIG_ETX094, CONFIG_NX823, CONFIG_cogent_mpc8260, 358 CONFIG_EVB64260, CONFIG_OCRTC, CONFIG_cogent_mpc8xx, 359 CONFIG_FADS823, CONFIG_ORSG, CONFIG_ep8260, 360 CONFIG_FADS850SAR, CONFIG_OXC, CONFIG_gw8260, 361 CONFIG_FADS860T, CONFIG_PCI405, CONFIG_hermes, 362 CONFIG_FLAGADM, CONFIG_PCIPPC2, CONFIG_hymod, 363 CONFIG_FPS850L, CONFIG_PCIPPC6, CONFIG_lwmon, 364 CONFIG_GEN860T, CONFIG_PIP405, CONFIG_pcu_e, 365 CONFIG_GENIETV, CONFIG_PM826, CONFIG_ppmc8260, 366 CONFIG_GTH, CONFIG_RPXClassic, CONFIG_rsdproto, 367 CONFIG_IAD210, CONFIG_RPXlite, CONFIG_sbc8260, 368 CONFIG_EBONY, CONFIG_sacsng, CONFIG_FPS860L, 369 CONFIG_V37, CONFIG_ELPT860, CONFIG_CMI, 370 CONFIG_NETVIA, CONFIG_RBC823, CONFIG_ZPC1900, 371 CONFIG_MPC8540ADS, CONFIG_MPC8560ADS, CONFIG_QS850, 372 CONFIG_QS823, CONFIG_QS860T, CONFIG_DB64360, 373 CONFIG_DB64460, CONFIG_DUET_ADS 374 375 ARM based boards: 376 ----------------- 377 378 CONFIG_HHP_CRADLE, CONFIG_DNP1110, CONFIG_EP7312, 379 CONFIG_IMPA7, CONFIG_LART, CONFIG_LUBBOCK, 380 CONFIG_INNOVATOROMAP1510, CONFIG_INNOVATOROMAP1610 381 CONFIG_SHANNON, CONFIG_SMDK2400, CONFIG_SMDK2410, 382 CONFIG_TRAB, CONFIG_VCMA9, CONFIG_AT91RM9200DK 383 384 385- CPU Module Type: (if CONFIG_COGENT is defined) 386 Define exactly one of 387 CONFIG_CMA286_60_OLD 388--- FIXME --- not tested yet: 389 CONFIG_CMA286_60, CONFIG_CMA286_21, CONFIG_CMA286_60P, 390 CONFIG_CMA287_23, CONFIG_CMA287_50 391 392- Motherboard Type: (if CONFIG_COGENT is defined) 393 Define exactly one of 394 CONFIG_CMA101, CONFIG_CMA102 395 396- Motherboard I/O Modules: (if CONFIG_COGENT is defined) 397 Define one or more of 398 CONFIG_CMA302 399 400- Motherboard Options: (if CONFIG_CMA101 or CONFIG_CMA102 are defined) 401 Define one or more of 402 CONFIG_LCD_HEARTBEAT - update a character position on 403 the lcd display every second with 404 a "rotator" |\-/|\-/ 405 406- Board flavour: (if CONFIG_MPC8260ADS is defined) 407 CONFIG_ADSTYPE 408 Possible values are: 409 CFG_8260ADS - original MPC8260ADS 410 CFG_8266ADS - MPC8266ADS 411 CFG_PQ2FADS - PQ2FADS-ZU or PQ2FADS-VR 412 413 414- MPC824X Family Member (if CONFIG_MPC824X is defined) 415 Define exactly one of 416 CONFIG_MPC8240, CONFIG_MPC8245 417 418- 8xx CPU Options: (if using an MPC8xx cpu) 419 Define one or more of 420 CONFIG_8xx_GCLK_FREQ - if get_gclk_freq() cannot work 421 e.g. if there is no 32KHz 422 reference PIT/RTC clock 423 424- 859/866 CPU options: (if using a MPC859 or MPC866 CPU): 425 CFG_866_OSCCLK 426 CFG_866_CPUCLK_MIN 427 CFG_866_CPUCLK_MAX 428 CFG_866_CPUCLK_DEFAULT 429 See doc/README.MPC866 430 431 CFG_MEASURE_CPUCLK 432 433 Define this to measure the actual CPU clock instead 434 of relying on the correctness of the configured 435 values. Mostly useful for board bringup to make sure 436 the PLL is locked at the intended frequency. Note 437 that this requires a (stable) reference clock (32 kHz 438 RTC clock), 439 440- Linux Kernel Interface: 441 CONFIG_CLOCKS_IN_MHZ 442 443 U-Boot stores all clock information in Hz 444 internally. For binary compatibility with older Linux 445 kernels (which expect the clocks passed in the 446 bd_info data to be in MHz) the environment variable 447 "clocks_in_mhz" can be defined so that U-Boot 448 converts clock data to MHZ before passing it to the 449 Linux kernel. 450 When CONFIG_CLOCKS_IN_MHZ is defined, a definition of 451 "clocks_in_mhz=1" is automatically included in the 452 default environment. 453 454 CONFIG_MEMSIZE_IN_BYTES [relevant for MIPS only] 455 456 When transfering memsize parameter to linux, some versions 457 expect it to be in bytes, others in MB. 458 Define CONFIG_MEMSIZE_IN_BYTES to make it in bytes. 459 460- Console Interface: 461 Depending on board, define exactly one serial port 462 (like CONFIG_8xx_CONS_SMC1, CONFIG_8xx_CONS_SMC2, 463 CONFIG_8xx_CONS_SCC1, ...), or switch off the serial 464 console by defining CONFIG_8xx_CONS_NONE 465 466 Note: if CONFIG_8xx_CONS_NONE is defined, the serial 467 port routines must be defined elsewhere 468 (i.e. serial_init(), serial_getc(), ...) 469 470 CONFIG_CFB_CONSOLE 471 Enables console device for a color framebuffer. Needs following 472 defines (cf. smiLynxEM, i8042, board/eltec/bab7xx) 473 VIDEO_FB_LITTLE_ENDIAN graphic memory organisation 474 (default big endian) 475 VIDEO_HW_RECTFILL graphic chip supports 476 rectangle fill 477 (cf. smiLynxEM) 478 VIDEO_HW_BITBLT graphic chip supports 479 bit-blit (cf. smiLynxEM) 480 VIDEO_VISIBLE_COLS visible pixel columns 481 (cols=pitch) 482 VIDEO_VISIBLE_ROWS visible pixel rows 483 VIDEO_PIXEL_SIZE bytes per pixel 484 VIDEO_DATA_FORMAT graphic data format 485 (0-5, cf. cfb_console.c) 486 VIDEO_FB_ADRS framebuffer address 487 VIDEO_KBD_INIT_FCT keyboard int fct 488 (i.e. i8042_kbd_init()) 489 VIDEO_TSTC_FCT test char fct 490 (i.e. i8042_tstc) 491 VIDEO_GETC_FCT get char fct 492 (i.e. i8042_getc) 493 CONFIG_CONSOLE_CURSOR cursor drawing on/off 494 (requires blink timer 495 cf. i8042.c) 496 CFG_CONSOLE_BLINK_COUNT blink interval (cf. i8042.c) 497 CONFIG_CONSOLE_TIME display time/date info in 498 upper right corner 499 (requires CFG_CMD_DATE) 500 CONFIG_VIDEO_LOGO display Linux logo in 501 upper left corner 502 CONFIG_VIDEO_BMP_LOGO use bmp_logo.h instead of 503 linux_logo.h for logo. 504 Requires CONFIG_VIDEO_LOGO 505 CONFIG_CONSOLE_EXTRA_INFO 506 addional board info beside 507 the logo 508 509 When CONFIG_CFB_CONSOLE is defined, video console is 510 default i/o. Serial console can be forced with 511 environment 'console=serial'. 512 513 When CONFIG_SILENT_CONSOLE is defined, all console 514 messages (by U-Boot and Linux!) can be silenced with 515 the "silent" environment variable. See 516 doc/README.silent for more information. 517 518- Console Baudrate: 519 CONFIG_BAUDRATE - in bps 520 Select one of the baudrates listed in 521 CFG_BAUDRATE_TABLE, see below. 522 CFG_BRGCLK_PRESCALE, baudrate prescale 523 524- Interrupt driven serial port input: 525 CONFIG_SERIAL_SOFTWARE_FIFO 526 527 PPC405GP only. 528 Use an interrupt handler for receiving data on the 529 serial port. It also enables using hardware handshake 530 (RTS/CTS) and UART's built-in FIFO. Set the number of 531 bytes the interrupt driven input buffer should have. 532 533 Set to 0 to disable this feature (this is the default). 534 This will also disable hardware handshake. 535 536- Console UART Number: 537 CONFIG_UART1_CONSOLE 538 539 IBM PPC4xx only. 540 If defined internal UART1 (and not UART0) is used 541 as default U-Boot console. 542 543- Boot Delay: CONFIG_BOOTDELAY - in seconds 544 Delay before automatically booting the default image; 545 set to -1 to disable autoboot. 546 547 See doc/README.autoboot for these options that 548 work with CONFIG_BOOTDELAY. None are required. 549 CONFIG_BOOT_RETRY_TIME 550 CONFIG_BOOT_RETRY_MIN 551 CONFIG_AUTOBOOT_KEYED 552 CONFIG_AUTOBOOT_PROMPT 553 CONFIG_AUTOBOOT_DELAY_STR 554 CONFIG_AUTOBOOT_STOP_STR 555 CONFIG_AUTOBOOT_DELAY_STR2 556 CONFIG_AUTOBOOT_STOP_STR2 557 CONFIG_ZERO_BOOTDELAY_CHECK 558 CONFIG_RESET_TO_RETRY 559 560- Autoboot Command: 561 CONFIG_BOOTCOMMAND 562 Only needed when CONFIG_BOOTDELAY is enabled; 563 define a command string that is automatically executed 564 when no character is read on the console interface 565 within "Boot Delay" after reset. 566 567 CONFIG_BOOTARGS 568 This can be used to pass arguments to the bootm 569 command. The value of CONFIG_BOOTARGS goes into the 570 environment value "bootargs". 571 572 CONFIG_RAMBOOT and CONFIG_NFSBOOT 573 The value of these goes into the environment as 574 "ramboot" and "nfsboot" respectively, and can be used 575 as a convenience, when switching between booting from 576 ram and nfs. 577 578- Pre-Boot Commands: 579 CONFIG_PREBOOT 580 581 When this option is #defined, the existence of the 582 environment variable "preboot" will be checked 583 immediately before starting the CONFIG_BOOTDELAY 584 countdown and/or running the auto-boot command resp. 585 entering interactive mode. 586 587 This feature is especially useful when "preboot" is 588 automatically generated or modified. For an example 589 see the LWMON board specific code: here "preboot" is 590 modified when the user holds down a certain 591 combination of keys on the (special) keyboard when 592 booting the systems 593 594- Serial Download Echo Mode: 595 CONFIG_LOADS_ECHO 596 If defined to 1, all characters received during a 597 serial download (using the "loads" command) are 598 echoed back. This might be needed by some terminal 599 emulations (like "cu"), but may as well just take 600 time on others. This setting #define's the initial 601 value of the "loads_echo" environment variable. 602 603- Kgdb Serial Baudrate: (if CFG_CMD_KGDB is defined) 604 CONFIG_KGDB_BAUDRATE 605 Select one of the baudrates listed in 606 CFG_BAUDRATE_TABLE, see below. 607 608- Monitor Functions: 609 CONFIG_COMMANDS 610 Most monitor functions can be selected (or 611 de-selected) by adjusting the definition of 612 CONFIG_COMMANDS; to select individual functions, 613 #define CONFIG_COMMANDS by "OR"ing any of the 614 following values: 615 616 #define enables commands: 617 ------------------------- 618 CFG_CMD_ASKENV * ask for env variable 619 CFG_CMD_AUTOSCRIPT Autoscript Support 620 CFG_CMD_BDI bdinfo 621 CFG_CMD_BEDBUG Include BedBug Debugger 622 CFG_CMD_BMP * BMP support 623 CFG_CMD_BOOTD bootd 624 CFG_CMD_CACHE icache, dcache 625 CFG_CMD_CONSOLE coninfo 626 CFG_CMD_DATE * support for RTC, date/time... 627 CFG_CMD_DHCP DHCP support 628 CFG_CMD_DIAG * Diagnostics 629 CFG_CMD_DOC * Disk-On-Chip Support 630 CFG_CMD_DTT Digital Therm and Thermostat 631 CFG_CMD_ECHO * echo arguments 632 CFG_CMD_EEPROM * EEPROM read/write support 633 CFG_CMD_ELF bootelf, bootvx 634 CFG_CMD_ENV saveenv 635 CFG_CMD_FDC * Floppy Disk Support 636 CFG_CMD_FAT FAT partition support 637 CFG_CMD_FDOS * Dos diskette Support 638 CFG_CMD_FLASH flinfo, erase, protect 639 CFG_CMD_FPGA FPGA device initialization support 640 CFG_CMD_HWFLOW * RTS/CTS hw flow control 641 CFG_CMD_I2C * I2C serial bus support 642 CFG_CMD_IDE * IDE harddisk support 643 CFG_CMD_IMI iminfo 644 CFG_CMD_IMLS List all found images 645 CFG_CMD_IMMAP * IMMR dump support 646 CFG_CMD_IRQ * irqinfo 647 CFG_CMD_JFFS2 * JFFS2 Support 648 CFG_CMD_KGDB * kgdb 649 CFG_CMD_LOADB loadb 650 CFG_CMD_LOADS loads 651 CFG_CMD_MEMORY md, mm, nm, mw, cp, cmp, crc, base, 652 loop, mtest 653 CFG_CMD_MISC Misc functions like sleep etc 654 CFG_CMD_MMC MMC memory mapped support 655 CFG_CMD_MII MII utility commands 656 CFG_CMD_NAND * NAND support 657 CFG_CMD_NET bootp, tftpboot, rarpboot 658 CFG_CMD_PCI * pciinfo 659 CFG_CMD_PCMCIA * PCMCIA support 660 CFG_CMD_PING * send ICMP ECHO_REQUEST to network host 661 CFG_CMD_PORTIO * Port I/O 662 CFG_CMD_REGINFO * Register dump 663 CFG_CMD_RUN run command in env variable 664 CFG_CMD_SAVES save S record dump 665 CFG_CMD_SCSI * SCSI Support 666 CFG_CMD_SDRAM * print SDRAM configuration information 667 CFG_CMD_SETGETDCR Support for DCR Register access (4xx only) 668 CFG_CMD_SPI * SPI serial bus support 669 CFG_CMD_USB * USB support 670 CFG_CMD_VFD * VFD support (TRAB) 671 CFG_CMD_BSP * Board SPecific functions 672 ----------------------------------------------- 673 CFG_CMD_ALL all 674 675 CFG_CMD_DFL Default configuration; at the moment 676 this is includes all commands, except 677 the ones marked with "*" in the list 678 above. 679 680 If you don't define CONFIG_COMMANDS it defaults to 681 CFG_CMD_DFL in include/cmd_confdefs.h. A board can 682 override the default settings in the respective 683 include file. 684 685 EXAMPLE: If you want all functions except of network 686 support you can write: 687 688 #define CONFIG_COMMANDS (CFG_CMD_ALL & ~CFG_CMD_NET) 689 690 691 Note: Don't enable the "icache" and "dcache" commands 692 (configuration option CFG_CMD_CACHE) unless you know 693 what you (and your U-Boot users) are doing. Data 694 cache cannot be enabled on systems like the 8xx or 695 8260 (where accesses to the IMMR region must be 696 uncached), and it cannot be disabled on all other 697 systems where we (mis-) use the data cache to hold an 698 initial stack and some data. 699 700 701 XXX - this list needs to get updated! 702 703- Watchdog: 704 CONFIG_WATCHDOG 705 If this variable is defined, it enables watchdog 706 support. There must be support in the platform specific 707 code for a watchdog. For the 8xx and 8260 CPUs, the 708 SIU Watchdog feature is enabled in the SYPCR 709 register. 710 711- U-Boot Version: 712 CONFIG_VERSION_VARIABLE 713 If this variable is defined, an environment variable 714 named "ver" is created by U-Boot showing the U-Boot 715 version as printed by the "version" command. 716 This variable is readonly. 717 718- Real-Time Clock: 719 720 When CFG_CMD_DATE is selected, the type of the RTC 721 has to be selected, too. Define exactly one of the 722 following options: 723 724 CONFIG_RTC_MPC8xx - use internal RTC of MPC8xx 725 CONFIG_RTC_PCF8563 - use Philips PCF8563 RTC 726 CONFIG_RTC_MC146818 - use MC146818 RTC 727 CONFIG_RTC_DS1307 - use Maxim, Inc. DS1307 RTC 728 CONFIG_RTC_DS1337 - use Maxim, Inc. DS1337 RTC 729 CONFIG_RTC_DS1338 - use Maxim, Inc. DS1338 RTC 730 CONFIG_RTC_DS164x - use Dallas DS164x RTC 731 732 Note that if the RTC uses I2C, then the I2C interface 733 must also be configured. See I2C Support, below. 734 735- Timestamp Support: 736 737 When CONFIG_TIMESTAMP is selected, the timestamp 738 (date and time) of an image is printed by image 739 commands like bootm or iminfo. This option is 740 automatically enabled when you select CFG_CMD_DATE . 741 742- Partition Support: 743 CONFIG_MAC_PARTITION and/or CONFIG_DOS_PARTITION 744 and/or CONFIG_ISO_PARTITION 745 746 If IDE or SCSI support is enabled (CFG_CMD_IDE or 747 CFG_CMD_SCSI) you must configure support for at least 748 one partition type as well. 749 750- IDE Reset method: 751 CONFIG_IDE_RESET_ROUTINE 752 753 Set this to define that instead of a reset Pin, the 754 routine ide_set_reset(int idereset) will be used. 755 756- ATAPI Support: 757 CONFIG_ATAPI 758 759 Set this to enable ATAPI support. 760 761- SCSI Support: 762 At the moment only there is only support for the 763 SYM53C8XX SCSI controller; define 764 CONFIG_SCSI_SYM53C8XX to enable it. 765 766 CFG_SCSI_MAX_LUN [8], CFG_SCSI_MAX_SCSI_ID [7] and 767 CFG_SCSI_MAX_DEVICE [CFG_SCSI_MAX_SCSI_ID * 768 CFG_SCSI_MAX_LUN] can be adjusted to define the 769 maximum numbers of LUNs, SCSI ID's and target 770 devices. 771 CFG_SCSI_SYM53C8XX_CCF to fix clock timing (80Mhz) 772 773- NETWORK Support (PCI): 774 CONFIG_E1000 775 Support for Intel 8254x gigabit chips. 776 777 CONFIG_EEPRO100 778 Support for Intel 82557/82559/82559ER chips. 779 Optional CONFIG_EEPRO100_SROM_WRITE enables eeprom 780 write routine for first time initialisation. 781 782 CONFIG_TULIP 783 Support for Digital 2114x chips. 784 Optional CONFIG_TULIP_SELECT_MEDIA for board specific 785 modem chip initialisation (KS8761/QS6611). 786 787 CONFIG_NATSEMI 788 Support for National dp83815 chips. 789 790 CONFIG_NS8382X 791 Support for National dp8382[01] gigabit chips. 792 793- NETWORK Support (other): 794 795 CONFIG_DRIVER_LAN91C96 796 Support for SMSC's LAN91C96 chips. 797 798 CONFIG_LAN91C96_BASE 799 Define this to hold the physical address 800 of the LAN91C96's I/O space 801 802 CONFIG_LAN91C96_USE_32_BIT 803 Define this to enable 32 bit addressing 804 805- USB Support: 806 At the moment only the UHCI host controller is 807 supported (PIP405, MIP405); define 808 CONFIG_USB_UHCI to enable it. 809 define CONFIG_USB_KEYBOARD to enable the USB Keyboard 810 end define CONFIG_USB_STORAGE to enable the USB 811 storage devices. 812 Note: 813 Supported are USB Keyboards and USB Floppy drives 814 (TEAC FD-05PUB). 815 816- MMC Support: 817 The MMC controller on the Intel PXA is supported. To 818 enable this define CONFIG_MMC. The MMC can be 819 accessed from the boot prompt by mapping the device 820 to physical memory similar to flash. Command line is 821 enabled with CFG_CMD_MMC. The MMC driver also works with 822 the FAT fs. This is enabled with CFG_CMD_FAT. 823 824- Keyboard Support: 825 CONFIG_ISA_KEYBOARD 826 827 Define this to enable standard (PC-Style) keyboard 828 support 829 830 CONFIG_I8042_KBD 831 Standard PC keyboard driver with US (is default) and 832 GERMAN key layout (switch via environment 'keymap=de') support. 833 Export function i8042_kbd_init, i8042_tstc and i8042_getc 834 for cfb_console. Supports cursor blinking. 835 836- Video support: 837 CONFIG_VIDEO 838 839 Define this to enable video support (for output to 840 video). 841 842 CONFIG_VIDEO_CT69000 843 844 Enable Chips & Technologies 69000 Video chip 845 846 CONFIG_VIDEO_SMI_LYNXEM 847 Enable Silicon Motion SMI 712/710/810 Video chip 848 Videomode are selected via environment 'videomode' with 849 standard LiLo mode numbers. 850 Following modes are supported (* is default): 851 852 800x600 1024x768 1280x1024 853 256 (8bit) 303* 305 307 854 65536 (16bit) 314 317 31a 855 16,7 Mill (24bit) 315 318 31b 856 (i.e. setenv videomode 317; saveenv; reset;) 857 858 CONFIG_VIDEO_SED13806 859 Enable Epson SED13806 driver. This driver supports 8bpp 860 and 16bpp modes defined by CONFIG_VIDEO_SED13806_8BPP 861 or CONFIG_VIDEO_SED13806_16BPP 862 863- Keyboard Support: 864 CONFIG_KEYBOARD 865 866 Define this to enable a custom keyboard support. 867 This simply calls drv_keyboard_init() which must be 868 defined in your board-specific files. 869 The only board using this so far is RBC823. 870 871- LCD Support: CONFIG_LCD 872 873 Define this to enable LCD support (for output to LCD 874 display); also select one of the supported displays 875 by defining one of these: 876 877 CONFIG_NEC_NL6448AC33: 878 879 NEC NL6448AC33-18. Active, color, single scan. 880 881 CONFIG_NEC_NL6448BC20 882 883 NEC NL6448BC20-08. 6.5", 640x480. 884 Active, color, single scan. 885 886 CONFIG_NEC_NL6448BC33_54 887 888 NEC NL6448BC33-54. 10.4", 640x480. 889 Active, color, single scan. 890 891 CONFIG_SHARP_16x9 892 893 Sharp 320x240. Active, color, single scan. 894 It isn't 16x9, and I am not sure what it is. 895 896 CONFIG_SHARP_LQ64D341 897 898 Sharp LQ64D341 display, 640x480. 899 Active, color, single scan. 900 901 CONFIG_HLD1045 902 903 HLD1045 display, 640x480. 904 Active, color, single scan. 905 906 CONFIG_OPTREX_BW 907 908 Optrex CBL50840-2 NF-FW 99 22 M5 909 or 910 Hitachi LMG6912RPFC-00T 911 or 912 Hitachi SP14Q002 913 914 320x240. Black & white. 915 916 Normally display is black on white background; define 917 CFG_WHITE_ON_BLACK to get it inverted. 918 919- Splash Screen Support: CONFIG_SPLASH_SCREEN 920 921 If this option is set, the environment is checked for 922 a variable "splashimage". If found, the usual display 923 of logo, copyright and system information on the LCD 924 is supressed and the BMP image at the address 925 specified in "splashimage" is loaded instead. The 926 console is redirected to the "nulldev", too. This 927 allows for a "silent" boot where a splash screen is 928 loaded very quickly after power-on. 929 930- Compression support: 931 CONFIG_BZIP2 932 933 If this option is set, support for bzip2 compressed 934 images is included. If not, only uncompressed and gzip 935 compressed images are supported. 936 937 NOTE: the bzip2 algorithm requires a lot of RAM, so 938 the malloc area (as defined by CFG_MALLOC_LEN) should 939 be at least 4MB. 940 941- Ethernet address: 942 CONFIG_ETHADDR 943 CONFIG_ETH2ADDR 944 CONFIG_ETH3ADDR 945 946 Define a default value for ethernet address to use 947 for the respective ethernet interface, in case this 948 is not determined automatically. 949 950- IP address: 951 CONFIG_IPADDR 952 953 Define a default value for the IP address to use for 954 the default ethernet interface, in case this is not 955 determined through e.g. bootp. 956 957- Server IP address: 958 CONFIG_SERVERIP 959 960 Defines a default value for theIP address of a TFTP 961 server to contact when using the "tftboot" command. 962 963- BOOTP Recovery Mode: 964 CONFIG_BOOTP_RANDOM_DELAY 965 966 If you have many targets in a network that try to 967 boot using BOOTP, you may want to avoid that all 968 systems send out BOOTP requests at precisely the same 969 moment (which would happen for instance at recovery 970 from a power failure, when all systems will try to 971 boot, thus flooding the BOOTP server. Defining 972 CONFIG_BOOTP_RANDOM_DELAY causes a random delay to be 973 inserted before sending out BOOTP requests. The 974 following delays are insterted then: 975 976 1st BOOTP request: delay 0 ... 1 sec 977 2nd BOOTP request: delay 0 ... 2 sec 978 3rd BOOTP request: delay 0 ... 4 sec 979 4th and following 980 BOOTP requests: delay 0 ... 8 sec 981 982- DHCP Advanced Options: 983 CONFIG_BOOTP_MASK 984 985 You can fine tune the DHCP functionality by adding 986 these flags to the CONFIG_BOOTP_MASK define: 987 988 CONFIG_BOOTP_DNS2 - If a DHCP client requests the DNS 989 serverip from a DHCP server, it is possible that more 990 than one DNS serverip is offered to the client. 991 If CONFIG_BOOTP_DNS2 is enabled, the secondary DNS 992 serverip will be stored in the additional environment 993 variable "dnsip2". The first DNS serverip is always 994 stored in the variable "dnsip", when CONFIG_BOOTP_DNS 995 is added to the CONFIG_BOOTP_MASK. 996 997 CONFIG_BOOTP_SEND_HOSTNAME - Some DHCP servers are capable 998 to do a dynamic update of a DNS server. To do this, they 999 need the hostname of the DHCP requester. 1000 If CONFIG_BOOP_SEND_HOSTNAME is added to the 1001 CONFIG_BOOTP_MASK, the content of the "hostname" 1002 environment variable is passed as option 12 to 1003 the DHCP server. 1004 1005- Status LED: CONFIG_STATUS_LED 1006 1007 Several configurations allow to display the current 1008 status using a LED. For instance, the LED will blink 1009 fast while running U-Boot code, stop blinking as 1010 soon as a reply to a BOOTP request was received, and 1011 start blinking slow once the Linux kernel is running 1012 (supported by a status LED driver in the Linux 1013 kernel). Defining CONFIG_STATUS_LED enables this 1014 feature in U-Boot. 1015 1016- CAN Support: CONFIG_CAN_DRIVER 1017 1018 Defining CONFIG_CAN_DRIVER enables CAN driver support 1019 on those systems that support this (optional) 1020 feature, like the TQM8xxL modules. 1021 1022- I2C Support: CONFIG_HARD_I2C | CONFIG_SOFT_I2C 1023 1024 These enable I2C serial bus commands. Defining either of 1025 (but not both of) CONFIG_HARD_I2C or CONFIG_SOFT_I2C will 1026 include the appropriate I2C driver for the selected cpu. 1027 1028 This will allow you to use i2c commands at the u-boot 1029 command line (as long as you set CFG_CMD_I2C in 1030 CONFIG_COMMANDS) and communicate with i2c based realtime 1031 clock chips. See common/cmd_i2c.c for a description of the 1032 command line interface. 1033 1034 CONFIG_HARD_I2C selects the CPM hardware driver for I2C. 1035 1036 CONFIG_SOFT_I2C configures u-boot to use a software (aka 1037 bit-banging) driver instead of CPM or similar hardware 1038 support for I2C. 1039 1040 There are several other quantities that must also be 1041 defined when you define CONFIG_HARD_I2C or CONFIG_SOFT_I2C. 1042 1043 In both cases you will need to define CFG_I2C_SPEED 1044 to be the frequency (in Hz) at which you wish your i2c bus 1045 to run and CFG_I2C_SLAVE to be the address of this node (ie 1046 the cpu's i2c node address). 1047 1048 Now, the u-boot i2c code for the mpc8xx (cpu/mpc8xx/i2c.c) 1049 sets the cpu up as a master node and so its address should 1050 therefore be cleared to 0 (See, eg, MPC823e User's Manual 1051 p.16-473). So, set CFG_I2C_SLAVE to 0. 1052 1053 That's all that's required for CONFIG_HARD_I2C. 1054 1055 If you use the software i2c interface (CONFIG_SOFT_I2C) 1056 then the following macros need to be defined (examples are 1057 from include/configs/lwmon.h): 1058 1059 I2C_INIT 1060 1061 (Optional). Any commands necessary to enable the I2C 1062 controller or configure ports. 1063 1064 eg: #define I2C_INIT (immr->im_cpm.cp_pbdir |= PB_SCL) 1065 1066 I2C_PORT 1067 1068 (Only for MPC8260 CPU). The I/O port to use (the code 1069 assumes both bits are on the same port). Valid values 1070 are 0..3 for ports A..D. 1071 1072 I2C_ACTIVE 1073 1074 The code necessary to make the I2C data line active 1075 (driven). If the data line is open collector, this 1076 define can be null. 1077 1078 eg: #define I2C_ACTIVE (immr->im_cpm.cp_pbdir |= PB_SDA) 1079 1080 I2C_TRISTATE 1081 1082 The code necessary to make the I2C data line tri-stated 1083 (inactive). If the data line is open collector, this 1084 define can be null. 1085 1086 eg: #define I2C_TRISTATE (immr->im_cpm.cp_pbdir &= ~PB_SDA) 1087 1088 I2C_READ 1089 1090 Code that returns TRUE if the I2C data line is high, 1091 FALSE if it is low. 1092 1093 eg: #define I2C_READ ((immr->im_cpm.cp_pbdat & PB_SDA) != 0) 1094 1095 I2C_SDA(bit) 1096 1097 If <bit> is TRUE, sets the I2C data line high. If it 1098 is FALSE, it clears it (low). 1099 1100 eg: #define I2C_SDA(bit) \ 1101 if(bit) immr->im_cpm.cp_pbdat |= PB_SDA; \ 1102 else immr->im_cpm.cp_pbdat &= ~PB_SDA 1103 1104 I2C_SCL(bit) 1105 1106 If <bit> is TRUE, sets the I2C clock line high. If it 1107 is FALSE, it clears it (low). 1108 1109 eg: #define I2C_SCL(bit) \ 1110 if(bit) immr->im_cpm.cp_pbdat |= PB_SCL; \ 1111 else immr->im_cpm.cp_pbdat &= ~PB_SCL 1112 1113 I2C_DELAY 1114 1115 This delay is invoked four times per clock cycle so this 1116 controls the rate of data transfer. The data rate thus 1117 is 1 / (I2C_DELAY * 4). Often defined to be something 1118 like: 1119 1120 #define I2C_DELAY udelay(2) 1121 1122 CFG_I2C_INIT_BOARD 1123 1124 When a board is reset during an i2c bus transfer 1125 chips might think that the current transfer is still 1126 in progress. On some boards it is possible to access 1127 the i2c SCLK line directly, either by using the 1128 processor pin as a GPIO or by having a second pin 1129 connected to the bus. If this option is defined a 1130 custom i2c_init_board() routine in boards/xxx/board.c 1131 is run early in the boot sequence. 1132 1133- SPI Support: CONFIG_SPI 1134 1135 Enables SPI driver (so far only tested with 1136 SPI EEPROM, also an instance works with Crystal A/D and 1137 D/As on the SACSng board) 1138 1139 CONFIG_SPI_X 1140 1141 Enables extended (16-bit) SPI EEPROM addressing. 1142 (symmetrical to CONFIG_I2C_X) 1143 1144 CONFIG_SOFT_SPI 1145 1146 Enables a software (bit-bang) SPI driver rather than 1147 using hardware support. This is a general purpose 1148 driver that only requires three general I/O port pins 1149 (two outputs, one input) to function. If this is 1150 defined, the board configuration must define several 1151 SPI configuration items (port pins to use, etc). For 1152 an example, see include/configs/sacsng.h. 1153 1154- FPGA Support: CONFIG_FPGA_COUNT 1155 1156 Specify the number of FPGA devices to support. 1157 1158 CONFIG_FPGA 1159 1160 Used to specify the types of FPGA devices. For 1161 example, 1162 #define CONFIG_FPGA CFG_XILINX_VIRTEX2 1163 1164 CFG_FPGA_PROG_FEEDBACK 1165 1166 Enable printing of hash marks during FPGA 1167 configuration. 1168 1169 CFG_FPGA_CHECK_BUSY 1170 1171 Enable checks on FPGA configuration interface busy 1172 status by the configuration function. This option 1173 will require a board or device specific function to 1174 be written. 1175 1176 CONFIG_FPGA_DELAY 1177 1178 If defined, a function that provides delays in the 1179 FPGA configuration driver. 1180 1181 CFG_FPGA_CHECK_CTRLC 1182 1183 Allow Control-C to interrupt FPGA configuration 1184 1185 CFG_FPGA_CHECK_ERROR 1186 1187 Check for configuration errors during FPGA bitfile 1188 loading. For example, abort during Virtex II 1189 configuration if the INIT_B line goes low (which 1190 indicated a CRC error). 1191 1192 CFG_FPGA_WAIT_INIT 1193 1194 Maximum time to wait for the INIT_B line to deassert 1195 after PROB_B has been deasserted during a Virtex II 1196 FPGA configuration sequence. The default time is 500 mS. 1197 1198 CFG_FPGA_WAIT_BUSY 1199 1200 Maximum time to wait for BUSY to deassert during 1201 Virtex II FPGA configuration. The default is 5 mS. 1202 1203 CFG_FPGA_WAIT_CONFIG 1204 1205 Time to wait after FPGA configuration. The default is 1206 200 mS. 1207 1208- FPGA Support: CONFIG_FPGA_COUNT 1209 1210 Specify the number of FPGA devices to support. 1211 1212 CONFIG_FPGA 1213 1214 Used to specify the types of FPGA devices. For example, 1215 #define CONFIG_FPGA CFG_XILINX_VIRTEX2 1216 1217 CFG_FPGA_PROG_FEEDBACK 1218 1219 Enable printing of hash marks during FPGA configuration. 1220 1221 CFG_FPGA_CHECK_BUSY 1222 1223 Enable checks on FPGA configuration interface busy 1224 status by the configuration function. This option 1225 will require a board or device specific function to 1226 be written. 1227 1228 CONFIG_FPGA_DELAY 1229 1230 If defined, a function that provides delays in the FPGA 1231 configuration driver. 1232 1233 CFG_FPGA_CHECK_CTRLC 1234 Allow Control-C to interrupt FPGA configuration 1235 1236 CFG_FPGA_CHECK_ERROR 1237 1238 Check for configuration errors during FPGA bitfile 1239 loading. For example, abort during Virtex II 1240 configuration if the INIT_B line goes low (which 1241 indicated a CRC error). 1242 1243 CFG_FPGA_WAIT_INIT 1244 1245 Maximum time to wait for the INIT_B line to deassert 1246 after PROB_B has been deasserted during a Virtex II 1247 FPGA configuration sequence. The default time is 500 1248 mS. 1249 1250 CFG_FPGA_WAIT_BUSY 1251 1252 Maximum time to wait for BUSY to deassert during 1253 Virtex II FPGA configuration. The default is 5 mS. 1254 1255 CFG_FPGA_WAIT_CONFIG 1256 1257 Time to wait after FPGA configuration. The default is 1258 200 mS. 1259 1260- Configuration Management: 1261 CONFIG_IDENT_STRING 1262 1263 If defined, this string will be added to the U-Boot 1264 version information (U_BOOT_VERSION) 1265 1266- Vendor Parameter Protection: 1267 1268 U-Boot considers the values of the environment 1269 variables "serial#" (Board Serial Number) and 1270 "ethaddr" (Ethernet Address) to be parameters that 1271 are set once by the board vendor / manufacturer, and 1272 protects these variables from casual modification by 1273 the user. Once set, these variables are read-only, 1274 and write or delete attempts are rejected. You can 1275 change this behviour: 1276 1277 If CONFIG_ENV_OVERWRITE is #defined in your config 1278 file, the write protection for vendor parameters is 1279 completely disabled. Anybody can change or delete 1280 these parameters. 1281 1282 Alternatively, if you #define _both_ CONFIG_ETHADDR 1283 _and_ CONFIG_OVERWRITE_ETHADDR_ONCE, a default 1284 ethernet address is installed in the environment, 1285 which can be changed exactly ONCE by the user. [The 1286 serial# is unaffected by this, i. e. it remains 1287 read-only.] 1288 1289- Protected RAM: 1290 CONFIG_PRAM 1291 1292 Define this variable to enable the reservation of 1293 "protected RAM", i. e. RAM which is not overwritten 1294 by U-Boot. Define CONFIG_PRAM to hold the number of 1295 kB you want to reserve for pRAM. You can overwrite 1296 this default value by defining an environment 1297 variable "pram" to the number of kB you want to 1298 reserve. Note that the board info structure will 1299 still show the full amount of RAM. If pRAM is 1300 reserved, a new environment variable "mem" will 1301 automatically be defined to hold the amount of 1302 remaining RAM in a form that can be passed as boot 1303 argument to Linux, for instance like that: 1304 1305 setenv bootargs ... mem=\$(mem) 1306 saveenv 1307 1308 This way you can tell Linux not to use this memory, 1309 either, which results in a memory region that will 1310 not be affected by reboots. 1311 1312 *WARNING* If your board configuration uses automatic 1313 detection of the RAM size, you must make sure that 1314 this memory test is non-destructive. So far, the 1315 following board configurations are known to be 1316 "pRAM-clean": 1317 1318 ETX094, IVMS8, IVML24, SPD8xx, TQM8xxL, 1319 HERMES, IP860, RPXlite, LWMON, LANTEC, 1320 PCU_E, FLAGADM, TQM8260 1321 1322- Error Recovery: 1323 CONFIG_PANIC_HANG 1324 1325 Define this variable to stop the system in case of a 1326 fatal error, so that you have to reset it manually. 1327 This is probably NOT a good idea for an embedded 1328 system where you want to system to reboot 1329 automatically as fast as possible, but it may be 1330 useful during development since you can try to debug 1331 the conditions that lead to the situation. 1332 1333 CONFIG_NET_RETRY_COUNT 1334 1335 This variable defines the number of retries for 1336 network operations like ARP, RARP, TFTP, or BOOTP 1337 before giving up the operation. If not defined, a 1338 default value of 5 is used. 1339 1340- Command Interpreter: 1341 CFG_HUSH_PARSER 1342 1343 Define this variable to enable the "hush" shell (from 1344 Busybox) as command line interpreter, thus enabling 1345 powerful command line syntax like 1346 if...then...else...fi conditionals or `&&' and '||' 1347 constructs ("shell scripts"). 1348 1349 If undefined, you get the old, much simpler behaviour 1350 with a somewhat smaller memory footprint. 1351 1352 1353 CFG_PROMPT_HUSH_PS2 1354 1355 This defines the secondary prompt string, which is 1356 printed when the command interpreter needs more input 1357 to complete a command. Usually "> ". 1358 1359 Note: 1360 1361 In the current implementation, the local variables 1362 space and global environment variables space are 1363 separated. Local variables are those you define by 1364 simply typing `name=value'. To access a local 1365 variable later on, you have write `$name' or 1366 `${name}'; to execute the contents of a variable 1367 directly type `$name' at the command prompt. 1368 1369 Global environment variables are those you use 1370 setenv/printenv to work with. To run a command stored 1371 in such a variable, you need to use the run command, 1372 and you must not use the '$' sign to access them. 1373 1374 To store commands and special characters in a 1375 variable, please use double quotation marks 1376 surrounding the whole text of the variable, instead 1377 of the backslashes before semicolons and special 1378 symbols. 1379 1380- Default Environment: 1381 CONFIG_EXTRA_ENV_SETTINGS 1382 1383 Define this to contain any number of null terminated 1384 strings (variable = value pairs) that will be part of 1385 the default environment compiled into the boot image. 1386 1387 For example, place something like this in your 1388 board's config file: 1389 1390 #define CONFIG_EXTRA_ENV_SETTINGS \ 1391 "myvar1=value1\0" \ 1392 "myvar2=value2\0" 1393 1394 Warning: This method is based on knowledge about the 1395 internal format how the environment is stored by the 1396 U-Boot code. This is NOT an official, exported 1397 interface! Although it is unlikely that this format 1398 will change soon, there is no guarantee either. 1399 You better know what you are doing here. 1400 1401 Note: overly (ab)use of the default environment is 1402 discouraged. Make sure to check other ways to preset 1403 the environment like the autoscript function or the 1404 boot command first. 1405 1406- DataFlash Support: 1407 CONFIG_HAS_DATAFLASH 1408 1409 Defining this option enables DataFlash features and 1410 allows to read/write in Dataflash via the standard 1411 commands cp, md... 1412 1413- SystemACE Support: 1414 CONFIG_SYSTEMACE 1415 1416 Adding this option adds support for Xilinx SystemACE 1417 chips attached via some sort of local bus. The address 1418 of the chip must alsh be defined in the 1419 CFG_SYSTEMACE_BASE macro. For example: 1420 1421 #define CONFIG_SYSTEMACE 1422 #define CFG_SYSTEMACE_BASE 0xf0000000 1423 1424 When SystemACE support is added, the "ace" device type 1425 becomes available to the fat commands, i.e. fatls. 1426 1427- Show boot progress: 1428 CONFIG_SHOW_BOOT_PROGRESS 1429 1430 Defining this option allows to add some board- 1431 specific code (calling a user-provided function 1432 "show_boot_progress(int)") that enables you to show 1433 the system's boot progress on some display (for 1434 example, some LED's) on your board. At the moment, 1435 the following checkpoints are implemented: 1436 1437 Arg Where When 1438 1 common/cmd_bootm.c before attempting to boot an image 1439 -1 common/cmd_bootm.c Image header has bad magic number 1440 2 common/cmd_bootm.c Image header has correct magic number 1441 -2 common/cmd_bootm.c Image header has bad checksum 1442 3 common/cmd_bootm.c Image header has correct checksum 1443 -3 common/cmd_bootm.c Image data has bad checksum 1444 4 common/cmd_bootm.c Image data has correct checksum 1445 -4 common/cmd_bootm.c Image is for unsupported architecture 1446 5 common/cmd_bootm.c Architecture check OK 1447 -5 common/cmd_bootm.c Wrong Image Type (not kernel, multi, standalone) 1448 6 common/cmd_bootm.c Image Type check OK 1449 -6 common/cmd_bootm.c gunzip uncompression error 1450 -7 common/cmd_bootm.c Unimplemented compression type 1451 7 common/cmd_bootm.c Uncompression OK 1452 -8 common/cmd_bootm.c Wrong Image Type (not kernel, multi, standalone) 1453 8 common/cmd_bootm.c Image Type check OK 1454 -9 common/cmd_bootm.c Unsupported OS (not Linux, BSD, VxWorks, QNX) 1455 9 common/cmd_bootm.c Start initial ramdisk verification 1456 -10 common/cmd_bootm.c Ramdisk header has bad magic number 1457 -11 common/cmd_bootm.c Ramdisk header has bad checksum 1458 10 common/cmd_bootm.c Ramdisk header is OK 1459 -12 common/cmd_bootm.c Ramdisk data has bad checksum 1460 11 common/cmd_bootm.c Ramdisk data has correct checksum 1461 12 common/cmd_bootm.c Ramdisk verification complete, start loading 1462 -13 common/cmd_bootm.c Wrong Image Type (not PPC Linux Ramdisk) 1463 13 common/cmd_bootm.c Start multifile image verification 1464 14 common/cmd_bootm.c No initial ramdisk, no multifile, continue. 1465 15 common/cmd_bootm.c All preparation done, transferring control to OS 1466 1467 -1 common/cmd_doc.c Bad usage of "doc" command 1468 -1 common/cmd_doc.c No boot device 1469 -1 common/cmd_doc.c Unknown Chip ID on boot device 1470 -1 common/cmd_doc.c Read Error on boot device 1471 -1 common/cmd_doc.c Image header has bad magic number 1472 1473 -1 common/cmd_ide.c Bad usage of "ide" command 1474 -1 common/cmd_ide.c No boot device 1475 -1 common/cmd_ide.c Unknown boot device 1476 -1 common/cmd_ide.c Unknown partition table 1477 -1 common/cmd_ide.c Invalid partition type 1478 -1 common/cmd_ide.c Read Error on boot device 1479 -1 common/cmd_ide.c Image header has bad magic number 1480 1481 -1 common/cmd_nand.c Bad usage of "nand" command 1482 -1 common/cmd_nand.c No boot device 1483 -1 common/cmd_nand.c Unknown Chip ID on boot device 1484 -1 common/cmd_nand.c Read Error on boot device 1485 -1 common/cmd_nand.c Image header has bad magic number 1486 1487 -1 common/env_common.c Environment has a bad CRC, using default 1488 1489 1490Modem Support: 1491-------------- 1492 1493[so far only for SMDK2400 and TRAB boards] 1494 1495- Modem support endable: 1496 CONFIG_MODEM_SUPPORT 1497 1498- RTS/CTS Flow control enable: 1499 CONFIG_HWFLOW 1500 1501- Modem debug support: 1502 CONFIG_MODEM_SUPPORT_DEBUG 1503 1504 Enables debugging stuff (char screen[1024], dbg()) 1505 for modem support. Useful only with BDI2000. 1506 1507- Interrupt support (PPC): 1508 1509 There are common interrupt_init() and timer_interrupt() 1510 for all PPC archs. interrupt_init() calls interrupt_init_cpu() 1511 for cpu specific initialization. interrupt_init_cpu() 1512 should set decrementer_count to appropriate value. If 1513 cpu resets decrementer automatically after interrupt 1514 (ppc4xx) it should set decrementer_count to zero. 1515 timer_interrupt() calls timer_interrupt_cpu() for cpu 1516 specific handling. If board has watchdog / status_led 1517 / other_activity_monitor it works automatically from 1518 general timer_interrupt(). 1519 1520- General: 1521 1522 In the target system modem support is enabled when a 1523 specific key (key combination) is pressed during 1524 power-on. Otherwise U-Boot will boot normally 1525 (autoboot). The key_pressed() fuction is called from 1526 board_init(). Currently key_pressed() is a dummy 1527 function, returning 1 and thus enabling modem 1528 initialization. 1529 1530 If there are no modem init strings in the 1531 environment, U-Boot proceed to autoboot; the 1532 previous output (banner, info printfs) will be 1533 supressed, though. 1534 1535 See also: doc/README.Modem 1536 1537 1538Configuration Settings: 1539----------------------- 1540 1541- CFG_LONGHELP: Defined when you want long help messages included; 1542 undefine this when you're short of memory. 1543 1544- CFG_PROMPT: This is what U-Boot prints on the console to 1545 prompt for user input. 1546 1547- CFG_CBSIZE: Buffer size for input from the Console 1548 1549- CFG_PBSIZE: Buffer size for Console output 1550 1551- CFG_MAXARGS: max. Number of arguments accepted for monitor commands 1552 1553- CFG_BARGSIZE: Buffer size for Boot Arguments which are passed to 1554 the application (usually a Linux kernel) when it is 1555 booted 1556 1557- CFG_BAUDRATE_TABLE: 1558 List of legal baudrate settings for this board. 1559 1560- CFG_CONSOLE_INFO_QUIET 1561 Suppress display of console information at boot. 1562 1563- CFG_CONSOLE_IS_IN_ENV 1564 If the board specific function 1565 extern int overwrite_console (void); 1566 returns 1, the stdin, stderr and stdout are switched to the 1567 serial port, else the settings in the environment are used. 1568 1569- CFG_CONSOLE_OVERWRITE_ROUTINE 1570 Enable the call to overwrite_console(). 1571 1572- CFG_CONSOLE_ENV_OVERWRITE 1573 Enable overwrite of previous console environment settings. 1574 1575- CFG_MEMTEST_START, CFG_MEMTEST_END: 1576 Begin and End addresses of the area used by the 1577 simple memory test. 1578 1579- CFG_ALT_MEMTEST: 1580 Enable an alternate, more extensive memory test. 1581 1582- CFG_MEMTEST_SCRATCH: 1583 Scratch address used by the alternate memory test 1584 You only need to set this if address zero isn't writeable 1585 1586- CFG_TFTP_LOADADDR: 1587 Default load address for network file downloads 1588 1589- CFG_LOADS_BAUD_CHANGE: 1590 Enable temporary baudrate change while serial download 1591 1592- CFG_SDRAM_BASE: 1593 Physical start address of SDRAM. _Must_ be 0 here. 1594 1595- CFG_MBIO_BASE: 1596 Physical start address of Motherboard I/O (if using a 1597 Cogent motherboard) 1598 1599- CFG_FLASH_BASE: 1600 Physical start address of Flash memory. 1601 1602- CFG_MONITOR_BASE: 1603 Physical start address of boot monitor code (set by 1604 make config files to be same as the text base address 1605 (TEXT_BASE) used when linking) - same as 1606 CFG_FLASH_BASE when booting from flash. 1607 1608- CFG_MONITOR_LEN: 1609 Size of memory reserved for monitor code, used to 1610 determine _at_compile_time_ (!) if the environment is 1611 embedded within the U-Boot image, or in a separate 1612 flash sector. 1613 1614- CFG_MALLOC_LEN: 1615 Size of DRAM reserved for malloc() use. 1616 1617- CFG_BOOTMAPSZ: 1618 Maximum size of memory mapped by the startup code of 1619 the Linux kernel; all data that must be processed by 1620 the Linux kernel (bd_info, boot arguments, eventually 1621 initrd image) must be put below this limit. 1622 1623- CFG_MAX_FLASH_BANKS: 1624 Max number of Flash memory banks 1625 1626- CFG_MAX_FLASH_SECT: 1627 Max number of sectors on a Flash chip 1628 1629- CFG_FLASH_ERASE_TOUT: 1630 Timeout for Flash erase operations (in ms) 1631 1632- CFG_FLASH_WRITE_TOUT: 1633 Timeout for Flash write operations (in ms) 1634 1635- CFG_FLASH_LOCK_TOUT 1636 Timeout for Flash set sector lock bit operation (in ms) 1637 1638- CFG_FLASH_UNLOCK_TOUT 1639 Timeout for Flash clear lock bits operation (in ms) 1640 1641- CFG_FLASH_PROTECTION 1642 If defined, hardware flash sectors protection is used 1643 instead of U-Boot software protection. 1644 1645- CFG_DIRECT_FLASH_TFTP: 1646 1647 Enable TFTP transfers directly to flash memory; 1648 without this option such a download has to be 1649 performed in two steps: (1) download to RAM, and (2) 1650 copy from RAM to flash. 1651 1652 The two-step approach is usually more reliable, since 1653 you can check if the download worked before you erase 1654 the flash, but in some situations (when sytem RAM is 1655 too limited to allow for a tempory copy of the 1656 downloaded image) this option may be very useful. 1657 1658- CFG_FLASH_CFI: 1659 Define if the flash driver uses extra elements in the 1660 common flash structure for storing flash geometry. 1661 1662- CFG_FLASH_CFI_DRIVER 1663 This option also enables the building of the cfi_flash driver 1664 in the drivers directory 1665 1666- CFG_RX_ETH_BUFFER: 1667 Defines the number of ethernet receive buffers. On some 1668 ethernet controllers it is recommended to set this value 1669 to 8 or even higher (EEPRO100 or 405 EMAC), since all 1670 buffers can be full shortly after enabling the interface 1671 on high ethernet traffic. 1672 Defaults to 4 if not defined. 1673 1674The following definitions that deal with the placement and management 1675of environment data (variable area); in general, we support the 1676following configurations: 1677 1678- CFG_ENV_IS_IN_FLASH: 1679 1680 Define this if the environment is in flash memory. 1681 1682 a) The environment occupies one whole flash sector, which is 1683 "embedded" in the text segment with the U-Boot code. This 1684 happens usually with "bottom boot sector" or "top boot 1685 sector" type flash chips, which have several smaller 1686 sectors at the start or the end. For instance, such a 1687 layout can have sector sizes of 8, 2x4, 16, Nx32 kB. In 1688 such a case you would place the environment in one of the 1689 4 kB sectors - with U-Boot code before and after it. With 1690 "top boot sector" type flash chips, you would put the 1691 environment in one of the last sectors, leaving a gap 1692 between U-Boot and the environment. 1693 1694 - CFG_ENV_OFFSET: 1695 1696 Offset of environment data (variable area) to the 1697 beginning of flash memory; for instance, with bottom boot 1698 type flash chips the second sector can be used: the offset 1699 for this sector is given here. 1700 1701 CFG_ENV_OFFSET is used relative to CFG_FLASH_BASE. 1702 1703 - CFG_ENV_ADDR: 1704 1705 This is just another way to specify the start address of 1706 the flash sector containing the environment (instead of 1707 CFG_ENV_OFFSET). 1708 1709 - CFG_ENV_SECT_SIZE: 1710 1711 Size of the sector containing the environment. 1712 1713 1714 b) Sometimes flash chips have few, equal sized, BIG sectors. 1715 In such a case you don't want to spend a whole sector for 1716 the environment. 1717 1718 - CFG_ENV_SIZE: 1719 1720 If you use this in combination with CFG_ENV_IS_IN_FLASH 1721 and CFG_ENV_SECT_SIZE, you can specify to use only a part 1722 of this flash sector for the environment. This saves 1723 memory for the RAM copy of the environment. 1724 1725 It may also save flash memory if you decide to use this 1726 when your environment is "embedded" within U-Boot code, 1727 since then the remainder of the flash sector could be used 1728 for U-Boot code. It should be pointed out that this is 1729 STRONGLY DISCOURAGED from a robustness point of view: 1730 updating the environment in flash makes it always 1731 necessary to erase the WHOLE sector. If something goes 1732 wrong before the contents has been restored from a copy in 1733 RAM, your target system will be dead. 1734 1735 - CFG_ENV_ADDR_REDUND 1736 CFG_ENV_SIZE_REDUND 1737 1738 These settings describe a second storage area used to hold 1739 a redundand copy of the environment data, so that there is 1740 a valid backup copy in case there is a power failure during 1741 a "saveenv" operation. 1742 1743BE CAREFUL! Any changes to the flash layout, and some changes to the 1744source code will make it necessary to adapt <board>/u-boot.lds* 1745accordingly! 1746 1747 1748- CFG_ENV_IS_IN_NVRAM: 1749 1750 Define this if you have some non-volatile memory device 1751 (NVRAM, battery buffered SRAM) which you want to use for the 1752 environment. 1753 1754 - CFG_ENV_ADDR: 1755 - CFG_ENV_SIZE: 1756 1757 These two #defines are used to determin the memory area you 1758 want to use for environment. It is assumed that this memory 1759 can just be read and written to, without any special 1760 provision. 1761 1762BE CAREFUL! The first access to the environment happens quite early 1763in U-Boot initalization (when we try to get the setting of for the 1764console baudrate). You *MUST* have mappend your NVRAM area then, or 1765U-Boot will hang. 1766 1767Please note that even with NVRAM we still use a copy of the 1768environment in RAM: we could work on NVRAM directly, but we want to 1769keep settings there always unmodified except somebody uses "saveenv" 1770to save the current settings. 1771 1772 1773- CFG_ENV_IS_IN_EEPROM: 1774 1775 Use this if you have an EEPROM or similar serial access 1776 device and a driver for it. 1777 1778 - CFG_ENV_OFFSET: 1779 - CFG_ENV_SIZE: 1780 1781 These two #defines specify the offset and size of the 1782 environment area within the total memory of your EEPROM. 1783 1784 - CFG_I2C_EEPROM_ADDR: 1785 If defined, specified the chip address of the EEPROM device. 1786 The default address is zero. 1787 1788 - CFG_EEPROM_PAGE_WRITE_BITS: 1789 If defined, the number of bits used to address bytes in a 1790 single page in the EEPROM device. A 64 byte page, for example 1791 would require six bits. 1792 1793 - CFG_EEPROM_PAGE_WRITE_DELAY_MS: 1794 If defined, the number of milliseconds to delay between 1795 page writes. The default is zero milliseconds. 1796 1797 - CFG_I2C_EEPROM_ADDR_LEN: 1798 The length in bytes of the EEPROM memory array address. Note 1799 that this is NOT the chip address length! 1800 1801 - CFG_EEPROM_SIZE: 1802 The size in bytes of the EEPROM device. 1803 1804 1805- CFG_ENV_IS_IN_DATAFLASH: 1806 1807 Define this if you have a DataFlash memory device which you 1808 want to use for the environment. 1809 1810 - CFG_ENV_OFFSET: 1811 - CFG_ENV_ADDR: 1812 - CFG_ENV_SIZE: 1813 1814 These three #defines specify the offset and size of the 1815 environment area within the total memory of your DataFlash placed 1816 at the specified address. 1817 1818 1819- CFG_SPI_INIT_OFFSET 1820 1821 Defines offset to the initial SPI buffer area in DPRAM. The 1822 area is used at an early stage (ROM part) if the environment 1823 is configured to reside in the SPI EEPROM: We need a 520 byte 1824 scratch DPRAM area. It is used between the two initialization 1825 calls (spi_init_f() and spi_init_r()). A value of 0xB00 seems 1826 to be a good choice since it makes it far enough from the 1827 start of the data area as well as from the stack pointer. 1828 1829Please note that the environment is read-only as long as the monitor 1830has been relocated to RAM and a RAM copy of the environment has been 1831created; also, when using EEPROM you will have to use getenv_r() 1832until then to read environment variables. 1833 1834The environment is protected by a CRC32 checksum. Before the monitor 1835is relocated into RAM, as a result of a bad CRC you will be working 1836with the compiled-in default environment - *silently*!!! [This is 1837necessary, because the first environment variable we need is the 1838"baudrate" setting for the console - if we have a bad CRC, we don't 1839have any device yet where we could complain.] 1840 1841Note: once the monitor has been relocated, then it will complain if 1842the default environment is used; a new CRC is computed as soon as you 1843use the "saveenv" command to store a valid environment. 1844 1845- CFG_FAULT_ECHO_LINK_DOWN: 1846 Echo the inverted Ethernet link state to the fault LED. 1847 1848 Note: If this option is active, then CFG_FAULT_MII_ADDR 1849 also needs to be defined. 1850 1851- CFG_FAULT_MII_ADDR: 1852 MII address of the PHY to check for the Ethernet link state. 1853 1854Low Level (hardware related) configuration options: 1855--------------------------------------------------- 1856 1857- CFG_CACHELINE_SIZE: 1858 Cache Line Size of the CPU. 1859 1860- CFG_DEFAULT_IMMR: 1861 Default address of the IMMR after system reset. 1862 1863 Needed on some 8260 systems (MPC8260ADS, PQ2FADS-ZU, 1864 and RPXsuper) to be able to adjust the position of 1865 the IMMR register after a reset. 1866 1867- Floppy Disk Support: 1868 CFG_FDC_DRIVE_NUMBER 1869 1870 the default drive number (default value 0) 1871 1872 CFG_ISA_IO_STRIDE 1873 1874 defines the spacing between fdc chipset registers 1875 (default value 1) 1876 1877 CFG_ISA_IO_OFFSET 1878 1879 defines the offset of register from address. It 1880 depends on which part of the data bus is connected to 1881 the fdc chipset. (default value 0) 1882 1883 If CFG_ISA_IO_STRIDE CFG_ISA_IO_OFFSET and 1884 CFG_FDC_DRIVE_NUMBER are undefined, they take their 1885 default value. 1886 1887 if CFG_FDC_HW_INIT is defined, then the function 1888 fdc_hw_init() is called at the beginning of the FDC 1889 setup. fdc_hw_init() must be provided by the board 1890 source code. It is used to make hardware dependant 1891 initializations. 1892 1893- CFG_IMMR: Physical address of the Internal Memory Mapped 1894 Register; DO NOT CHANGE! (11-4) 1895 [MPC8xx systems only] 1896 1897- CFG_INIT_RAM_ADDR: 1898 1899 Start address of memory area that can be used for 1900 initial data and stack; please note that this must be 1901 writable memory that is working WITHOUT special 1902 initialization, i. e. you CANNOT use normal RAM which 1903 will become available only after programming the 1904 memory controller and running certain initialization 1905 sequences. 1906 1907 U-Boot uses the following memory types: 1908 - MPC8xx and MPC8260: IMMR (internal memory of the CPU) 1909 - MPC824X: data cache 1910 - PPC4xx: data cache 1911 1912- CFG_GBL_DATA_OFFSET: 1913 1914 Offset of the initial data structure in the memory 1915 area defined by CFG_INIT_RAM_ADDR. Usually 1916 CFG_GBL_DATA_OFFSET is chosen such that the initial 1917 data is located at the end of the available space 1918 (sometimes written as (CFG_INIT_RAM_END - 1919 CFG_INIT_DATA_SIZE), and the initial stack is just 1920 below that area (growing from (CFG_INIT_RAM_ADDR + 1921 CFG_GBL_DATA_OFFSET) downward. 1922 1923 Note: 1924 On the MPC824X (or other systems that use the data 1925 cache for initial memory) the address chosen for 1926 CFG_INIT_RAM_ADDR is basically arbitrary - it must 1927 point to an otherwise UNUSED address space between 1928 the top of RAM and the start of the PCI space. 1929 1930- CFG_SIUMCR: SIU Module Configuration (11-6) 1931 1932- CFG_SYPCR: System Protection Control (11-9) 1933 1934- CFG_TBSCR: Time Base Status and Control (11-26) 1935 1936- CFG_PISCR: Periodic Interrupt Status and Control (11-31) 1937 1938- CFG_PLPRCR: PLL, Low-Power, and Reset Control Register (15-30) 1939 1940- CFG_SCCR: System Clock and reset Control Register (15-27) 1941 1942- CFG_OR_TIMING_SDRAM: 1943 SDRAM timing 1944 1945- CFG_MAMR_PTA: 1946 periodic timer for refresh 1947 1948- CFG_DER: Debug Event Register (37-47) 1949 1950- FLASH_BASE0_PRELIM, FLASH_BASE1_PRELIM, CFG_REMAP_OR_AM, 1951 CFG_PRELIM_OR_AM, CFG_OR_TIMING_FLASH, CFG_OR0_REMAP, 1952 CFG_OR0_PRELIM, CFG_BR0_PRELIM, CFG_OR1_REMAP, CFG_OR1_PRELIM, 1953 CFG_BR1_PRELIM: 1954 Memory Controller Definitions: BR0/1 and OR0/1 (FLASH) 1955 1956- SDRAM_BASE2_PRELIM, SDRAM_BASE3_PRELIM, SDRAM_MAX_SIZE, 1957 CFG_OR_TIMING_SDRAM, CFG_OR2_PRELIM, CFG_BR2_PRELIM, 1958 CFG_OR3_PRELIM, CFG_BR3_PRELIM: 1959 Memory Controller Definitions: BR2/3 and OR2/3 (SDRAM) 1960 1961- CFG_MAMR_PTA, CFG_MPTPR_2BK_4K, CFG_MPTPR_1BK_4K, CFG_MPTPR_2BK_8K, 1962 CFG_MPTPR_1BK_8K, CFG_MAMR_8COL, CFG_MAMR_9COL: 1963 Machine Mode Register and Memory Periodic Timer 1964 Prescaler definitions (SDRAM timing) 1965 1966- CFG_I2C_UCODE_PATCH, CFG_I2C_DPMEM_OFFSET [0x1FC0]: 1967 enable I2C microcode relocation patch (MPC8xx); 1968 define relocation offset in DPRAM [DSP2] 1969 1970- CFG_SPI_UCODE_PATCH, CFG_SPI_DPMEM_OFFSET [0x1FC0]: 1971 enable SPI microcode relocation patch (MPC8xx); 1972 define relocation offset in DPRAM [SCC4] 1973 1974- CFG_USE_OSCCLK: 1975 Use OSCM clock mode on MBX8xx board. Be careful, 1976 wrong setting might damage your board. Read 1977 doc/README.MBX before setting this variable! 1978 1979- CFG_CPM_POST_WORD_ADDR: (MPC8xx, MPC8260 only) 1980 Offset of the bootmode word in DPRAM used by post 1981 (Power On Self Tests). This definition overrides 1982 #define'd default value in commproc.h resp. 1983 cpm_8260.h. 1984 1985- CFG_PCI_SLV_MEM_LOCAL, CFG_PCI_SLV_MEM_BUS, CFG_PICMR0_MASK_ATTRIB, 1986 CFG_PCI_MSTR0_LOCAL, CFG_PCIMSK0_MASK, CFG_PCI_MSTR1_LOCAL, 1987 CFG_PCIMSK1_MASK, CFG_PCI_MSTR_MEM_LOCAL, CFG_PCI_MSTR_MEM_BUS, 1988 CFG_CPU_PCI_MEM_START, CFG_PCI_MSTR_MEM_SIZE, CFG_POCMR0_MASK_ATTRIB, 1989 CFG_PCI_MSTR_MEMIO_LOCAL, CFG_PCI_MSTR_MEMIO_BUS, CPU_PCI_MEMIO_START, 1990 CFG_PCI_MSTR_MEMIO_SIZE, CFG_POCMR1_MASK_ATTRIB, CFG_PCI_MSTR_IO_LOCAL, 1991 CFG_PCI_MSTR_IO_BUS, CFG_CPU_PCI_IO_START, CFG_PCI_MSTR_IO_SIZE, 1992 CFG_POCMR2_MASK_ATTRIB: (MPC826x only) 1993 Overrides the default PCI memory map in cpu/mpc8260/pci.c if set. 1994 1995Building the Software: 1996====================== 1997 1998Building U-Boot has been tested in native PPC environments (on a 1999PowerBook G3 running LinuxPPC 2000) and in cross environments 2000(running RedHat 6.x and 7.x Linux on x86, Solaris 2.6 on a SPARC, and 2001NetBSD 1.5 on x86). 2002 2003If you are not using a native PPC environment, it is assumed that you 2004have the GNU cross compiling tools available in your path and named 2005with a prefix of "powerpc-linux-". If this is not the case, (e.g. if 2006you are using Monta Vista's Hard Hat Linux CDK 1.2) you must change 2007the definition of CROSS_COMPILE in Makefile. For HHL on a 4xx CPU, 2008change it to: 2009 2010 CROSS_COMPILE = ppc_4xx- 2011 2012 2013U-Boot is intended to be simple to build. After installing the 2014sources you must configure U-Boot for one specific board type. This 2015is done by typing: 2016 2017 make NAME_config 2018 2019where "NAME_config" is the name of one of the existing 2020configurations; the following names are supported: 2021 2022 ADCIOP_config GTH_config TQM850L_config 2023 ADS860_config IP860_config TQM855L_config 2024 AR405_config IVML24_config TQM860L_config 2025 CANBT_config IVMS8_config WALNUT405_config 2026 CPCI405_config LANTEC_config cogent_common_config 2027 CPCIISER4_config MBX_config cogent_mpc8260_config 2028 CU824_config MBX860T_config cogent_mpc8xx_config 2029 ESTEEM192E_config RPXlite_config hermes_config 2030 ETX094_config RPXsuper_config hymod_config 2031 FADS823_config SM850_config lwmon_config 2032 FADS850SAR_config SPD823TS_config pcu_e_config 2033 FADS860T_config SXNI855T_config rsdproto_config 2034 FPS850L_config Sandpoint8240_config sbc8260_config 2035 GENIETV_config TQM823L_config PIP405_config 2036 GEN860T_config EBONY_config FPS860L_config 2037 ELPT860_config cmi_mpc5xx_config NETVIA_config 2038 at91rm9200dk_config omap1510inn_config MPC8260ADS_config 2039 omap1610inn_config ZPC1900_config MPC8540ADS_config 2040 MPC8560ADS_config QS850_config QS823_config 2041 QS860T_config DUET_ADS_config 2042 2043Note: for some board special configuration names may exist; check if 2044 additional information is available from the board vendor; for 2045 instance, the TQM8xxL systems run normally at 50 MHz and use a 2046 SCC for 10baseT ethernet; there are also systems with 80 MHz 2047 CPU clock, and an optional Fast Ethernet module is available 2048 for CPU's with FEC. You can select such additional "features" 2049 when chosing the configuration, i. e. 2050 2051 make TQM860L_config 2052 - will configure for a plain TQM860L, i. e. 50MHz, no FEC 2053 2054 make TQM860L_FEC_config 2055 - will configure for a TQM860L at 50MHz with FEC for ethernet 2056 2057 make TQM860L_80MHz_config 2058 - will configure for a TQM860L at 80 MHz, with normal 10baseT 2059 interface 2060 2061 make TQM860L_FEC_80MHz_config 2062 - will configure for a TQM860L at 80 MHz with FEC for ethernet 2063 2064 make TQM823L_LCD_config 2065 - will configure for a TQM823L with U-Boot console on LCD 2066 2067 make TQM823L_LCD_80MHz_config 2068 - will configure for a TQM823L at 80 MHz with U-Boot console on LCD 2069 2070 etc. 2071 2072 2073Finally, type "make all", and you should get some working U-Boot 2074images ready for download to / installation on your system: 2075 2076- "u-boot.bin" is a raw binary image 2077- "u-boot" is an image in ELF binary format 2078- "u-boot.srec" is in Motorola S-Record format 2079 2080 2081Please be aware that the Makefiles assume you are using GNU make, so 2082for instance on NetBSD you might need to use "gmake" instead of 2083native "make". 2084 2085 2086If the system board that you have is not listed, then you will need 2087to port U-Boot to your hardware platform. To do this, follow these 2088steps: 2089 20901. Add a new configuration option for your board to the toplevel 2091 "Makefile" and to the "MAKEALL" script, using the existing 2092 entries as examples. Note that here and at many other places 2093 boards and other names are listed in alphabetical sort order. Please 2094 keep this order. 20952. Create a new directory to hold your board specific code. Add any 2096 files you need. In your board directory, you will need at least 2097 the "Makefile", a "<board>.c", "flash.c" and "u-boot.lds". 20983. Create a new configuration file "include/configs/<board>.h" for 2099 your board 21003. If you're porting U-Boot to a new CPU, then also create a new 2101 directory to hold your CPU specific code. Add any files you need. 21024. Run "make <board>_config" with your new name. 21035. Type "make", and you should get a working "u-boot.srec" file 2104 to be installed on your target system. 21056. Debug and solve any problems that might arise. 2106 [Of course, this last step is much harder than it sounds.] 2107 2108 2109Testing of U-Boot Modifications, Ports to New Hardware, etc.: 2110============================================================== 2111 2112If you have modified U-Boot sources (for instance added a new board 2113or support for new devices, a new CPU, etc.) you are expected to 2114provide feedback to the other developers. The feedback normally takes 2115the form of a "patch", i. e. a context diff against a certain (latest 2116official or latest in CVS) version of U-Boot sources. 2117 2118But before you submit such a patch, please verify that your modifi- 2119cation did not break existing code. At least make sure that *ALL* of 2120the supported boards compile WITHOUT ANY compiler warnings. To do so, 2121just run the "MAKEALL" script, which will configure and build U-Boot 2122for ALL supported system. Be warned, this will take a while. You can 2123select which (cross) compiler to use by passing a `CROSS_COMPILE' 2124environment variable to the script, i. e. to use the cross tools from 2125MontaVista's Hard Hat Linux you can type 2126 2127 CROSS_COMPILE=ppc_8xx- MAKEALL 2128 2129or to build on a native PowerPC system you can type 2130 2131 CROSS_COMPILE=' ' MAKEALL 2132 2133See also "U-Boot Porting Guide" below. 2134 2135 2136Monitor Commands - Overview: 2137============================ 2138 2139go - start application at address 'addr' 2140run - run commands in an environment variable 2141bootm - boot application image from memory 2142bootp - boot image via network using BootP/TFTP protocol 2143tftpboot- boot image via network using TFTP protocol 2144 and env variables "ipaddr" and "serverip" 2145 (and eventually "gatewayip") 2146rarpboot- boot image via network using RARP/TFTP protocol 2147diskboot- boot from IDE devicebootd - boot default, i.e., run 'bootcmd' 2148loads - load S-Record file over serial line 2149loadb - load binary file over serial line (kermit mode) 2150md - memory display 2151mm - memory modify (auto-incrementing) 2152nm - memory modify (constant address) 2153mw - memory write (fill) 2154cp - memory copy 2155cmp - memory compare 2156crc32 - checksum calculation 2157imd - i2c memory display 2158imm - i2c memory modify (auto-incrementing) 2159inm - i2c memory modify (constant address) 2160imw - i2c memory write (fill) 2161icrc32 - i2c checksum calculation 2162iprobe - probe to discover valid I2C chip addresses 2163iloop - infinite loop on address range 2164isdram - print SDRAM configuration information 2165sspi - SPI utility commands 2166base - print or set address offset 2167printenv- print environment variables 2168setenv - set environment variables 2169saveenv - save environment variables to persistent storage 2170protect - enable or disable FLASH write protection 2171erase - erase FLASH memory 2172flinfo - print FLASH memory information 2173bdinfo - print Board Info structure 2174iminfo - print header information for application image 2175coninfo - print console devices and informations 2176ide - IDE sub-system 2177loop - infinite loop on address range 2178mtest - simple RAM test 2179icache - enable or disable instruction cache 2180dcache - enable or disable data cache 2181reset - Perform RESET of the CPU 2182echo - echo args to console 2183version - print monitor version 2184help - print online help 2185? - alias for 'help' 2186 2187 2188Monitor Commands - Detailed Description: 2189======================================== 2190 2191TODO. 2192 2193For now: just type "help <command>". 2194 2195 2196Environment Variables: 2197====================== 2198 2199U-Boot supports user configuration using Environment Variables which 2200can be made persistent by saving to Flash memory. 2201 2202Environment Variables are set using "setenv", printed using 2203"printenv", and saved to Flash using "saveenv". Using "setenv" 2204without a value can be used to delete a variable from the 2205environment. As long as you don't save the environment you are 2206working with an in-memory copy. In case the Flash area containing the 2207environment is erased by accident, a default environment is provided. 2208 2209Some configuration options can be set using Environment Variables: 2210 2211 baudrate - see CONFIG_BAUDRATE 2212 2213 bootdelay - see CONFIG_BOOTDELAY 2214 2215 bootcmd - see CONFIG_BOOTCOMMAND 2216 2217 bootargs - Boot arguments when booting an RTOS image 2218 2219 bootfile - Name of the image to load with TFTP 2220 2221 autoload - if set to "no" (any string beginning with 'n'), 2222 "bootp" will just load perform a lookup of the 2223 configuration from the BOOTP server, but not try to 2224 load any image using TFTP 2225 2226 autostart - if set to "yes", an image loaded using the "bootp", 2227 "rarpboot", "tftpboot" or "diskboot" commands will 2228 be automatically started (by internally calling 2229 "bootm") 2230 2231 If set to "no", a standalone image passed to the 2232 "bootm" command will be copied to the load address 2233 (and eventually uncompressed), but NOT be started. 2234 This can be used to load and uncompress arbitrary 2235 data. 2236 2237 initrd_high - restrict positioning of initrd images: 2238 If this variable is not set, initrd images will be 2239 copied to the highest possible address in RAM; this 2240 is usually what you want since it allows for 2241 maximum initrd size. If for some reason you want to 2242 make sure that the initrd image is loaded below the 2243 CFG_BOOTMAPSZ limit, you can set this environment 2244 variable to a value of "no" or "off" or "0". 2245 Alternatively, you can set it to a maximum upper 2246 address to use (U-Boot will still check that it 2247 does not overwrite the U-Boot stack and data). 2248 2249 For instance, when you have a system with 16 MB 2250 RAM, and want to reserve 4 MB from use by Linux, 2251 you can do this by adding "mem=12M" to the value of 2252 the "bootargs" variable. However, now you must make 2253 sure that the initrd image is placed in the first 2254 12 MB as well - this can be done with 2255 2256 setenv initrd_high 00c00000 2257 2258 If you set initrd_high to 0xFFFFFFFF, this is an 2259 indication to U-Boot that all addresses are legal 2260 for the Linux kernel, including addresses in flash 2261 memory. In this case U-Boot will NOT COPY the 2262 ramdisk at all. This may be useful to reduce the 2263 boot time on your system, but requires that this 2264 feature is supported by your Linux kernel. 2265 2266 ipaddr - IP address; needed for tftpboot command 2267 2268 loadaddr - Default load address for commands like "bootp", 2269 "rarpboot", "tftpboot", "loadb" or "diskboot" 2270 2271 loads_echo - see CONFIG_LOADS_ECHO 2272 2273 serverip - TFTP server IP address; needed for tftpboot command 2274 2275 bootretry - see CONFIG_BOOT_RETRY_TIME 2276 2277 bootdelaykey - see CONFIG_AUTOBOOT_DELAY_STR 2278 2279 bootstopkey - see CONFIG_AUTOBOOT_STOP_STR 2280 2281 2282The following environment variables may be used and automatically 2283updated by the network boot commands ("bootp" and "rarpboot"), 2284depending the information provided by your boot server: 2285 2286 bootfile - see above 2287 dnsip - IP address of your Domain Name Server 2288 dnsip2 - IP address of your secondary Domain Name Server 2289 gatewayip - IP address of the Gateway (Router) to use 2290 hostname - Target hostname 2291 ipaddr - see above 2292 netmask - Subnet Mask 2293 rootpath - Pathname of the root filesystem on the NFS server 2294 serverip - see above 2295 2296 2297There are two special Environment Variables: 2298 2299 serial# - contains hardware identification information such 2300 as type string and/or serial number 2301 ethaddr - Ethernet address 2302 2303These variables can be set only once (usually during manufacturing of 2304the board). U-Boot refuses to delete or overwrite these variables 2305once they have been set once. 2306 2307 2308Further special Environment Variables: 2309 2310 ver - Contains the U-Boot version string as printed 2311 with the "version" command. This variable is 2312 readonly (see CONFIG_VERSION_VARIABLE). 2313 2314 2315Please note that changes to some configuration parameters may take 2316only effect after the next boot (yes, that's just like Windoze :-). 2317 2318 2319Command Line Parsing: 2320===================== 2321 2322There are two different command line parsers available with U-Boot: 2323the old "simple" one, and the much more powerful "hush" shell: 2324 2325Old, simple command line parser: 2326-------------------------------- 2327 2328- supports environment variables (through setenv / saveenv commands) 2329- several commands on one line, separated by ';' 2330- variable substitution using "... $(name) ..." syntax 2331- special characters ('$', ';') can be escaped by prefixing with '\', 2332 for example: 2333 setenv bootcmd bootm \$(address) 2334- You can also escape text by enclosing in single apostrophes, for example: 2335 setenv addip 'setenv bootargs $bootargs ip=$ipaddr:$serverip:$gatewayip:$netmask:$hostname::off' 2336 2337Hush shell: 2338----------- 2339 2340- similar to Bourne shell, with control structures like 2341 if...then...else...fi, for...do...done; while...do...done, 2342 until...do...done, ... 2343- supports environment ("global") variables (through setenv / saveenv 2344 commands) and local shell variables (through standard shell syntax 2345 "name=value"); only environment variables can be used with "run" 2346 command 2347 2348General rules: 2349-------------- 2350 2351(1) If a command line (or an environment variable executed by a "run" 2352 command) contains several commands separated by semicolon, and 2353 one of these commands fails, then the remaining commands will be 2354 executed anyway. 2355 2356(2) If you execute several variables with one call to run (i. e. 2357 calling run with a list af variables as arguments), any failing 2358 command will cause "run" to terminate, i. e. the remaining 2359 variables are not executed. 2360 2361Note for Redundant Ethernet Interfaces: 2362======================================= 2363 2364Some boards come with redundant ethernet interfaces; U-Boot supports 2365such configurations and is capable of automatic selection of a 2366"working" interface when needed. MAC assignment works as follows: 2367 2368Network interfaces are numbered eth0, eth1, eth2, ... Corresponding 2369MAC addresses can be stored in the environment as "ethaddr" (=>eth0), 2370"eth1addr" (=>eth1), "eth2addr", ... 2371 2372If the network interface stores some valid MAC address (for instance 2373in SROM), this is used as default address if there is NO correspon- 2374ding setting in the environment; if the corresponding environment 2375variable is set, this overrides the settings in the card; that means: 2376 2377o If the SROM has a valid MAC address, and there is no address in the 2378 environment, the SROM's address is used. 2379 2380o If there is no valid address in the SROM, and a definition in the 2381 environment exists, then the value from the environment variable is 2382 used. 2383 2384o If both the SROM and the environment contain a MAC address, and 2385 both addresses are the same, this MAC address is used. 2386 2387o If both the SROM and the environment contain a MAC address, and the 2388 addresses differ, the value from the environment is used and a 2389 warning is printed. 2390 2391o If neither SROM nor the environment contain a MAC address, an error 2392 is raised. 2393 2394 2395Image Formats: 2396============== 2397 2398The "boot" commands of this monitor operate on "image" files which 2399can be basicly anything, preceeded by a special header; see the 2400definitions in include/image.h for details; basicly, the header 2401defines the following image properties: 2402 2403* Target Operating System (Provisions for OpenBSD, NetBSD, FreeBSD, 2404 4.4BSD, Linux, SVR4, Esix, Solaris, Irix, SCO, Dell, NCR, VxWorks, 2405 LynxOS, pSOS, QNX, RTEMS, ARTOS; 2406 Currently supported: Linux, NetBSD, VxWorks, QNX, RTEMS, ARTOS, LynxOS). 2407* Target CPU Architecture (Provisions for Alpha, ARM, Intel x86, 2408 IA64, MIPS, NIOS, PowerPC, IBM S390, SuperH, Sparc, Sparc 64 Bit; 2409 Currently supported: ARM, Intel x86, MIPS, NIOS, PowerPC). 2410* Compression Type (uncompressed, gzip, bzip2) 2411* Load Address 2412* Entry Point 2413* Image Name 2414* Image Timestamp 2415 2416The header is marked by a special Magic Number, and both the header 2417and the data portions of the image are secured against corruption by 2418CRC32 checksums. 2419 2420 2421Linux Support: 2422============== 2423 2424Although U-Boot should support any OS or standalone application 2425easily, the main focus has always been on Linux during the design of 2426U-Boot. 2427 2428U-Boot includes many features that so far have been part of some 2429special "boot loader" code within the Linux kernel. Also, any 2430"initrd" images to be used are no longer part of one big Linux image; 2431instead, kernel and "initrd" are separate images. This implementation 2432serves several purposes: 2433 2434- the same features can be used for other OS or standalone 2435 applications (for instance: using compressed images to reduce the 2436 Flash memory footprint) 2437 2438- it becomes much easier to port new Linux kernel versions because 2439 lots of low-level, hardware dependent stuff are done by U-Boot 2440 2441- the same Linux kernel image can now be used with different "initrd" 2442 images; of course this also means that different kernel images can 2443 be run with the same "initrd". This makes testing easier (you don't 2444 have to build a new "zImage.initrd" Linux image when you just 2445 change a file in your "initrd"). Also, a field-upgrade of the 2446 software is easier now. 2447 2448 2449Linux HOWTO: 2450============ 2451 2452Porting Linux to U-Boot based systems: 2453--------------------------------------- 2454 2455U-Boot cannot save you from doing all the necessary modifications to 2456configure the Linux device drivers for use with your target hardware 2457(no, we don't intend to provide a full virtual machine interface to 2458Linux :-). 2459 2460But now you can ignore ALL boot loader code (in arch/ppc/mbxboot). 2461 2462Just make sure your machine specific header file (for instance 2463include/asm-ppc/tqm8xx.h) includes the same definition of the Board 2464Information structure as we define in include/u-boot.h, and make 2465sure that your definition of IMAP_ADDR uses the same value as your 2466U-Boot configuration in CFG_IMMR. 2467 2468 2469Configuring the Linux kernel: 2470----------------------------- 2471 2472No specific requirements for U-Boot. Make sure you have some root 2473device (initial ramdisk, NFS) for your target system. 2474 2475 2476Building a Linux Image: 2477----------------------- 2478 2479With U-Boot, "normal" build targets like "zImage" or "bzImage" are 2480not used. If you use recent kernel source, a new build target 2481"uImage" will exist which automatically builds an image usable by 2482U-Boot. Most older kernels also have support for a "pImage" target, 2483which was introduced for our predecessor project PPCBoot and uses a 2484100% compatible format. 2485 2486Example: 2487 2488 make TQM850L_config 2489 make oldconfig 2490 make dep 2491 make uImage 2492 2493The "uImage" build target uses a special tool (in 'tools/mkimage') to 2494encapsulate a compressed Linux kernel image with header information, 2495CRC32 checksum etc. for use with U-Boot. This is what we are doing: 2496 2497* build a standard "vmlinux" kernel image (in ELF binary format): 2498 2499* convert the kernel into a raw binary image: 2500 2501 ${CROSS_COMPILE}-objcopy -O binary \ 2502 -R .note -R .comment \ 2503 -S vmlinux linux.bin 2504 2505* compress the binary image: 2506 2507 gzip -9 linux.bin 2508 2509* package compressed binary image for U-Boot: 2510 2511 mkimage -A ppc -O linux -T kernel -C gzip \ 2512 -a 0 -e 0 -n "Linux Kernel Image" \ 2513 -d linux.bin.gz uImage 2514 2515 2516The "mkimage" tool can also be used to create ramdisk images for use 2517with U-Boot, either separated from the Linux kernel image, or 2518combined into one file. "mkimage" encapsulates the images with a 64 2519byte header containing information about target architecture, 2520operating system, image type, compression method, entry points, time 2521stamp, CRC32 checksums, etc. 2522 2523"mkimage" can be called in two ways: to verify existing images and 2524print the header information, or to build new images. 2525 2526In the first form (with "-l" option) mkimage lists the information 2527contained in the header of an existing U-Boot image; this includes 2528checksum verification: 2529 2530 tools/mkimage -l image 2531 -l ==> list image header information 2532 2533The second form (with "-d" option) is used to build a U-Boot image 2534from a "data file" which is used as image payload: 2535 2536 tools/mkimage -A arch -O os -T type -C comp -a addr -e ep \ 2537 -n name -d data_file image 2538 -A ==> set architecture to 'arch' 2539 -O ==> set operating system to 'os' 2540 -T ==> set image type to 'type' 2541 -C ==> set compression type 'comp' 2542 -a ==> set load address to 'addr' (hex) 2543 -e ==> set entry point to 'ep' (hex) 2544 -n ==> set image name to 'name' 2545 -d ==> use image data from 'datafile' 2546 2547Right now, all Linux kernels use the same load address (0x00000000), 2548but the entry point address depends on the kernel version: 2549 2550- 2.2.x kernels have the entry point at 0x0000000C, 2551- 2.3.x and later kernels have the entry point at 0x00000000. 2552 2553So a typical call to build a U-Boot image would read: 2554 2555 -> tools/mkimage -n '2.4.4 kernel for TQM850L' \ 2556 > -A ppc -O linux -T kernel -C gzip -a 0 -e 0 \ 2557 > -d /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/ppc/coffboot/vmlinux.gz \ 2558 > examples/uImage.TQM850L 2559 Image Name: 2.4.4 kernel for TQM850L 2560 Created: Wed Jul 19 02:34:59 2000 2561 Image Type: PowerPC Linux Kernel Image (gzip compressed) 2562 Data Size: 335725 Bytes = 327.86 kB = 0.32 MB 2563 Load Address: 0x00000000 2564 Entry Point: 0x00000000 2565 2566To verify the contents of the image (or check for corruption): 2567 2568 -> tools/mkimage -l examples/uImage.TQM850L 2569 Image Name: 2.4.4 kernel for TQM850L 2570 Created: Wed Jul 19 02:34:59 2000 2571 Image Type: PowerPC Linux Kernel Image (gzip compressed) 2572 Data Size: 335725 Bytes = 327.86 kB = 0.32 MB 2573 Load Address: 0x00000000 2574 Entry Point: 0x00000000 2575 2576NOTE: for embedded systems where boot time is critical you can trade 2577speed for memory and install an UNCOMPRESSED image instead: this 2578needs more space in Flash, but boots much faster since it does not 2579need to be uncompressed: 2580 2581 -> gunzip /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/ppc/coffboot/vmlinux.gz 2582 -> tools/mkimage -n '2.4.4 kernel for TQM850L' \ 2583 > -A ppc -O linux -T kernel -C none -a 0 -e 0 \ 2584 > -d /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/ppc/coffboot/vmlinux \ 2585 > examples/uImage.TQM850L-uncompressed 2586 Image Name: 2.4.4 kernel for TQM850L 2587 Created: Wed Jul 19 02:34:59 2000 2588 Image Type: PowerPC Linux Kernel Image (uncompressed) 2589 Data Size: 792160 Bytes = 773.59 kB = 0.76 MB 2590 Load Address: 0x00000000 2591 Entry Point: 0x00000000 2592 2593 2594Similar you can build U-Boot images from a 'ramdisk.image.gz' file 2595when your kernel is intended to use an initial ramdisk: 2596 2597 -> tools/mkimage -n 'Simple Ramdisk Image' \ 2598 > -A ppc -O linux -T ramdisk -C gzip \ 2599 > -d /LinuxPPC/images/SIMPLE-ramdisk.image.gz examples/simple-initrd 2600 Image Name: Simple Ramdisk Image 2601 Created: Wed Jan 12 14:01:50 2000 2602 Image Type: PowerPC Linux RAMDisk Image (gzip compressed) 2603 Data Size: 566530 Bytes = 553.25 kB = 0.54 MB 2604 Load Address: 0x00000000 2605 Entry Point: 0x00000000 2606 2607 2608Installing a Linux Image: 2609------------------------- 2610 2611To downloading a U-Boot image over the serial (console) interface, 2612you must convert the image to S-Record format: 2613 2614 objcopy -I binary -O srec examples/image examples/image.srec 2615 2616The 'objcopy' does not understand the information in the U-Boot 2617image header, so the resulting S-Record file will be relative to 2618address 0x00000000. To load it to a given address, you need to 2619specify the target address as 'offset' parameter with the 'loads' 2620command. 2621 2622Example: install the image to address 0x40100000 (which on the 2623TQM8xxL is in the first Flash bank): 2624 2625 => erase 40100000 401FFFFF 2626 2627 .......... done 2628 Erased 8 sectors 2629 2630 => loads 40100000 2631 ## Ready for S-Record download ... 2632 ~>examples/image.srec 2633 1 2 3 4 5 6 7 8 9 10 11 12 13 ... 2634 ... 2635 15989 15990 15991 15992 2636 [file transfer complete] 2637 [connected] 2638 ## Start Addr = 0x00000000 2639 2640 2641You can check the success of the download using the 'iminfo' command; 2642this includes a checksum verification so you can be sure no data 2643corruption happened: 2644 2645 => imi 40100000 2646 2647 ## Checking Image at 40100000 ... 2648 Image Name: 2.2.13 for initrd on TQM850L 2649 Image Type: PowerPC Linux Kernel Image (gzip compressed) 2650 Data Size: 335725 Bytes = 327 kB = 0 MB 2651 Load Address: 00000000 2652 Entry Point: 0000000c 2653 Verifying Checksum ... OK 2654 2655 2656Boot Linux: 2657----------- 2658 2659The "bootm" command is used to boot an application that is stored in 2660memory (RAM or Flash). In case of a Linux kernel image, the contents 2661of the "bootargs" environment variable is passed to the kernel as 2662parameters. You can check and modify this variable using the 2663"printenv" and "setenv" commands: 2664 2665 2666 => printenv bootargs 2667 bootargs=root=/dev/ram 2668 2669 => setenv bootargs root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2 2670 2671 => printenv bootargs 2672 bootargs=root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2 2673 2674 => bootm 40020000 2675 ## Booting Linux kernel at 40020000 ... 2676 Image Name: 2.2.13 for NFS on TQM850L 2677 Image Type: PowerPC Linux Kernel Image (gzip compressed) 2678 Data Size: 381681 Bytes = 372 kB = 0 MB 2679 Load Address: 00000000 2680 Entry Point: 0000000c 2681 Verifying Checksum ... OK 2682 Uncompressing Kernel Image ... OK 2683 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 2684 Boot arguments: root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2 2685 time_init: decrementer frequency = 187500000/60 2686 Calibrating delay loop... 49.77 BogoMIPS 2687 Memory: 15208k available (700k kernel code, 444k data, 32k init) [c0000000,c1000000] 2688 ... 2689 2690If you want to boot a Linux kernel with initial ram disk, you pass 2691the memory addresses of both the kernel and the initrd image (PPBCOOT 2692format!) to the "bootm" command: 2693 2694 => imi 40100000 40200000 2695 2696 ## Checking Image at 40100000 ... 2697 Image Name: 2.2.13 for initrd on TQM850L 2698 Image Type: PowerPC Linux Kernel Image (gzip compressed) 2699 Data Size: 335725 Bytes = 327 kB = 0 MB 2700 Load Address: 00000000 2701 Entry Point: 0000000c 2702 Verifying Checksum ... OK 2703 2704 ## Checking Image at 40200000 ... 2705 Image Name: Simple Ramdisk Image 2706 Image Type: PowerPC Linux RAMDisk Image (gzip compressed) 2707 Data Size: 566530 Bytes = 553 kB = 0 MB 2708 Load Address: 00000000 2709 Entry Point: 00000000 2710 Verifying Checksum ... OK 2711 2712 => bootm 40100000 40200000 2713 ## Booting Linux kernel at 40100000 ... 2714 Image Name: 2.2.13 for initrd on TQM850L 2715 Image Type: PowerPC Linux Kernel Image (gzip compressed) 2716 Data Size: 335725 Bytes = 327 kB = 0 MB 2717 Load Address: 00000000 2718 Entry Point: 0000000c 2719 Verifying Checksum ... OK 2720 Uncompressing Kernel Image ... OK 2721 ## Loading RAMDisk Image at 40200000 ... 2722 Image Name: Simple Ramdisk Image 2723 Image Type: PowerPC Linux RAMDisk Image (gzip compressed) 2724 Data Size: 566530 Bytes = 553 kB = 0 MB 2725 Load Address: 00000000 2726 Entry Point: 00000000 2727 Verifying Checksum ... OK 2728 Loading Ramdisk ... OK 2729 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 2730 Boot arguments: root=/dev/ram 2731 time_init: decrementer frequency = 187500000/60 2732 Calibrating delay loop... 49.77 BogoMIPS 2733 ... 2734 RAMDISK: Compressed image found at block 0 2735 VFS: Mounted root (ext2 filesystem). 2736 2737 bash# 2738 2739More About U-Boot Image Types: 2740------------------------------ 2741 2742U-Boot supports the following image types: 2743 2744 "Standalone Programs" are directly runnable in the environment 2745 provided by U-Boot; it is expected that (if they behave 2746 well) you can continue to work in U-Boot after return from 2747 the Standalone Program. 2748 "OS Kernel Images" are usually images of some Embedded OS which 2749 will take over control completely. Usually these programs 2750 will install their own set of exception handlers, device 2751 drivers, set up the MMU, etc. - this means, that you cannot 2752 expect to re-enter U-Boot except by resetting the CPU. 2753 "RAMDisk Images" are more or less just data blocks, and their 2754 parameters (address, size) are passed to an OS kernel that is 2755 being started. 2756 "Multi-File Images" contain several images, typically an OS 2757 (Linux) kernel image and one or more data images like 2758 RAMDisks. This construct is useful for instance when you want 2759 to boot over the network using BOOTP etc., where the boot 2760 server provides just a single image file, but you want to get 2761 for instance an OS kernel and a RAMDisk image. 2762 2763 "Multi-File Images" start with a list of image sizes, each 2764 image size (in bytes) specified by an "uint32_t" in network 2765 byte order. This list is terminated by an "(uint32_t)0". 2766 Immediately after the terminating 0 follow the images, one by 2767 one, all aligned on "uint32_t" boundaries (size rounded up to 2768 a multiple of 4 bytes). 2769 2770 "Firmware Images" are binary images containing firmware (like 2771 U-Boot or FPGA images) which usually will be programmed to 2772 flash memory. 2773 2774 "Script files" are command sequences that will be executed by 2775 U-Boot's command interpreter; this feature is especially 2776 useful when you configure U-Boot to use a real shell (hush) 2777 as command interpreter. 2778 2779 2780Standalone HOWTO: 2781================= 2782 2783One of the features of U-Boot is that you can dynamically load and 2784run "standalone" applications, which can use some resources of 2785U-Boot like console I/O functions or interrupt services. 2786 2787Two simple examples are included with the sources: 2788 2789"Hello World" Demo: 2790------------------- 2791 2792'examples/hello_world.c' contains a small "Hello World" Demo 2793application; it is automatically compiled when you build U-Boot. 2794It's configured to run at address 0x00040004, so you can play with it 2795like that: 2796 2797 => loads 2798 ## Ready for S-Record download ... 2799 ~>examples/hello_world.srec 2800 1 2 3 4 5 6 7 8 9 10 11 ... 2801 [file transfer complete] 2802 [connected] 2803 ## Start Addr = 0x00040004 2804 2805 => go 40004 Hello World! This is a test. 2806 ## Starting application at 0x00040004 ... 2807 Hello World 2808 argc = 7 2809 argv[0] = "40004" 2810 argv[1] = "Hello" 2811 argv[2] = "World!" 2812 argv[3] = "This" 2813 argv[4] = "is" 2814 argv[5] = "a" 2815 argv[6] = "test." 2816 argv[7] = "<NULL>" 2817 Hit any key to exit ... 2818 2819 ## Application terminated, rc = 0x0 2820 2821Another example, which demonstrates how to register a CPM interrupt 2822handler with the U-Boot code, can be found in 'examples/timer.c'. 2823Here, a CPM timer is set up to generate an interrupt every second. 2824The interrupt service routine is trivial, just printing a '.' 2825character, but this is just a demo program. The application can be 2826controlled by the following keys: 2827 2828 ? - print current values og the CPM Timer registers 2829 b - enable interrupts and start timer 2830 e - stop timer and disable interrupts 2831 q - quit application 2832 2833 => loads 2834 ## Ready for S-Record download ... 2835 ~>examples/timer.srec 2836 1 2 3 4 5 6 7 8 9 10 11 ... 2837 [file transfer complete] 2838 [connected] 2839 ## Start Addr = 0x00040004 2840 2841 => go 40004 2842 ## Starting application at 0x00040004 ... 2843 TIMERS=0xfff00980 2844 Using timer 1 2845 tgcr @ 0xfff00980, tmr @ 0xfff00990, trr @ 0xfff00994, tcr @ 0xfff00998, tcn @ 0xfff0099c, ter @ 0xfff009b0 2846 2847Hit 'b': 2848 [q, b, e, ?] Set interval 1000000 us 2849 Enabling timer 2850Hit '?': 2851 [q, b, e, ?] ........ 2852 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0xef6, ter=0x0 2853Hit '?': 2854 [q, b, e, ?] . 2855 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x2ad4, ter=0x0 2856Hit '?': 2857 [q, b, e, ?] . 2858 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x1efc, ter=0x0 2859Hit '?': 2860 [q, b, e, ?] . 2861 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x169d, ter=0x0 2862Hit 'e': 2863 [q, b, e, ?] ...Stopping timer 2864Hit 'q': 2865 [q, b, e, ?] ## Application terminated, rc = 0x0 2866 2867 2868Minicom warning: 2869================ 2870 2871Over time, many people have reported problems when trying to use the 2872"minicom" terminal emulation program for serial download. I (wd) 2873consider minicom to be broken, and recommend not to use it. Under 2874Unix, I recommend to use C-Kermit for general purpose use (and 2875especially for kermit binary protocol download ("loadb" command), and 2876use "cu" for S-Record download ("loads" command). 2877 2878Nevertheless, if you absolutely want to use it try adding this 2879configuration to your "File transfer protocols" section: 2880 2881 Name Program Name U/D FullScr IO-Red. Multi 2882 X kermit /usr/bin/kermit -i -l %l -s Y U Y N N 2883 Y kermit /usr/bin/kermit -i -l %l -r N D Y N N 2884 2885 2886NetBSD Notes: 2887============= 2888 2889Starting at version 0.9.2, U-Boot supports NetBSD both as host 2890(build U-Boot) and target system (boots NetBSD/mpc8xx). 2891 2892Building requires a cross environment; it is known to work on 2893NetBSD/i386 with the cross-powerpc-netbsd-1.3 package (you will also 2894need gmake since the Makefiles are not compatible with BSD make). 2895Note that the cross-powerpc package does not install include files; 2896attempting to build U-Boot will fail because <machine/ansi.h> is 2897missing. This file has to be installed and patched manually: 2898 2899 # cd /usr/pkg/cross/powerpc-netbsd/include 2900 # mkdir powerpc 2901 # ln -s powerpc machine 2902 # cp /usr/src/sys/arch/powerpc/include/ansi.h powerpc/ansi.h 2903 # ${EDIT} powerpc/ansi.h ## must remove __va_list, _BSD_VA_LIST 2904 2905Native builds *don't* work due to incompatibilities between native 2906and U-Boot include files. 2907 2908Booting assumes that (the first part of) the image booted is a 2909stage-2 loader which in turn loads and then invokes the kernel 2910proper. Loader sources will eventually appear in the NetBSD source 2911tree (probably in sys/arc/mpc8xx/stand/u-boot_stage2/); in the 2912meantime, send mail to bruno@exet-ag.de and/or wd@denx.de for 2913details. 2914 2915 2916Implementation Internals: 2917========================= 2918 2919The following is not intended to be a complete description of every 2920implementation detail. However, it should help to understand the 2921inner workings of U-Boot and make it easier to port it to custom 2922hardware. 2923 2924 2925Initial Stack, Global Data: 2926--------------------------- 2927 2928The implementation of U-Boot is complicated by the fact that U-Boot 2929starts running out of ROM (flash memory), usually without access to 2930system RAM (because the memory controller is not initialized yet). 2931This means that we don't have writable Data or BSS segments, and BSS 2932is not initialized as zero. To be able to get a C environment working 2933at all, we have to allocate at least a minimal stack. Implementation 2934options for this are defined and restricted by the CPU used: Some CPU 2935models provide on-chip memory (like the IMMR area on MPC8xx and 2936MPC826x processors), on others (parts of) the data cache can be 2937locked as (mis-) used as memory, etc. 2938 2939 Chris Hallinan posted a good summary of these issues to the 2940 u-boot-users mailing list: 2941 2942 Subject: RE: [U-Boot-Users] RE: More On Memory Bank x (nothingness)? 2943 From: "Chris Hallinan" <clh@net1plus.com> 2944 Date: Mon, 10 Feb 2003 16:43:46 -0500 (22:43 MET) 2945 ... 2946 2947 Correct me if I'm wrong, folks, but the way I understand it 2948 is this: Using DCACHE as initial RAM for Stack, etc, does not 2949 require any physical RAM backing up the cache. The cleverness 2950 is that the cache is being used as a temporary supply of 2951 necessary storage before the SDRAM controller is setup. It's 2952 beyond the scope of this list to expain the details, but you 2953 can see how this works by studying the cache architecture and 2954 operation in the architecture and processor-specific manuals. 2955 2956 OCM is On Chip Memory, which I believe the 405GP has 4K. It 2957 is another option for the system designer to use as an 2958 initial stack/ram area prior to SDRAM being available. Either 2959 option should work for you. Using CS 4 should be fine if your 2960 board designers haven't used it for something that would 2961 cause you grief during the initial boot! It is frequently not 2962 used. 2963 2964 CFG_INIT_RAM_ADDR should be somewhere that won't interfere 2965 with your processor/board/system design. The default value 2966 you will find in any recent u-boot distribution in 2967 Walnut405.h should work for you. I'd set it to a value larger 2968 than your SDRAM module. If you have a 64MB SDRAM module, set 2969 it above 400_0000. Just make sure your board has no resources 2970 that are supposed to respond to that address! That code in 2971 start.S has been around a while and should work as is when 2972 you get the config right. 2973 2974 -Chris Hallinan 2975 DS4.COM, Inc. 2976 2977It is essential to remember this, since it has some impact on the C 2978code for the initialization procedures: 2979 2980* Initialized global data (data segment) is read-only. Do not attempt 2981 to write it. 2982 2983* Do not use any unitialized global data (or implicitely initialized 2984 as zero data - BSS segment) at all - this is undefined, initiali- 2985 zation is performed later (when relocating to RAM). 2986 2987* Stack space is very limited. Avoid big data buffers or things like 2988 that. 2989 2990Having only the stack as writable memory limits means we cannot use 2991normal global data to share information beween the code. But it 2992turned out that the implementation of U-Boot can be greatly 2993simplified by making a global data structure (gd_t) available to all 2994functions. We could pass a pointer to this data as argument to _all_ 2995functions, but this would bloat the code. Instead we use a feature of 2996the GCC compiler (Global Register Variables) to share the data: we 2997place a pointer (gd) to the global data into a register which we 2998reserve for this purpose. 2999 3000When choosing a register for such a purpose we are restricted by the 3001relevant (E)ABI specifications for the current architecture, and by 3002GCC's implementation. 3003 3004For PowerPC, the following registers have specific use: 3005 R1: stack pointer 3006 R2: TOC pointer 3007 R3-R4: parameter passing and return values 3008 R5-R10: parameter passing 3009 R13: small data area pointer 3010 R30: GOT pointer 3011 R31: frame pointer 3012 3013 (U-Boot also uses R14 as internal GOT pointer.) 3014 3015 ==> U-Boot will use R29 to hold a pointer to the global data 3016 3017 Note: on PPC, we could use a static initializer (since the 3018 address of the global data structure is known at compile time), 3019 but it turned out that reserving a register results in somewhat 3020 smaller code - although the code savings are not that big (on 3021 average for all boards 752 bytes for the whole U-Boot image, 3022 624 text + 127 data). 3023 3024On ARM, the following registers are used: 3025 3026 R0: function argument word/integer result 3027 R1-R3: function argument word 3028 R9: GOT pointer 3029 R10: stack limit (used only if stack checking if enabled) 3030 R11: argument (frame) pointer 3031 R12: temporary workspace 3032 R13: stack pointer 3033 R14: link register 3034 R15: program counter 3035 3036 ==> U-Boot will use R8 to hold a pointer to the global data 3037 3038 3039Memory Management: 3040------------------ 3041 3042U-Boot runs in system state and uses physical addresses, i.e. the 3043MMU is not used either for address mapping nor for memory protection. 3044 3045The available memory is mapped to fixed addresses using the memory 3046controller. In this process, a contiguous block is formed for each 3047memory type (Flash, SDRAM, SRAM), even when it consists of several 3048physical memory banks. 3049 3050U-Boot is installed in the first 128 kB of the first Flash bank (on 3051TQM8xxL modules this is the range 0x40000000 ... 0x4001FFFF). After 3052booting and sizing and initializing DRAM, the code relocates itself 3053to the upper end of DRAM. Immediately below the U-Boot code some 3054memory is reserved for use by malloc() [see CFG_MALLOC_LEN 3055configuration setting]. Below that, a structure with global Board 3056Info data is placed, followed by the stack (growing downward). 3057 3058Additionally, some exception handler code is copied to the low 8 kB 3059of DRAM (0x00000000 ... 0x00001FFF). 3060 3061So a typical memory configuration with 16 MB of DRAM could look like 3062this: 3063 3064 0x0000 0000 Exception Vector code 3065 : 3066 0x0000 1FFF 3067 0x0000 2000 Free for Application Use 3068 : 3069 : 3070 3071 : 3072 : 3073 0x00FB FF20 Monitor Stack (Growing downward) 3074 0x00FB FFAC Board Info Data and permanent copy of global data 3075 0x00FC 0000 Malloc Arena 3076 : 3077 0x00FD FFFF 3078 0x00FE 0000 RAM Copy of Monitor Code 3079 ... eventually: LCD or video framebuffer 3080 ... eventually: pRAM (Protected RAM - unchanged by reset) 3081 0x00FF FFFF [End of RAM] 3082 3083 3084System Initialization: 3085---------------------- 3086 3087In the reset configuration, U-Boot starts at the reset entry point 3088(on most PowerPC systens at address 0x00000100). Because of the reset 3089configuration for CS0# this is a mirror of the onboard Flash memory. 3090To be able to re-map memory U-Boot then jumps to its link address. 3091To be able to implement the initialization code in C, a (small!) 3092initial stack is set up in the internal Dual Ported RAM (in case CPUs 3093which provide such a feature like MPC8xx or MPC8260), or in a locked 3094part of the data cache. After that, U-Boot initializes the CPU core, 3095the caches and the SIU. 3096 3097Next, all (potentially) available memory banks are mapped using a 3098preliminary mapping. For example, we put them on 512 MB boundaries 3099(multiples of 0x20000000: SDRAM on 0x00000000 and 0x20000000, Flash 3100on 0x40000000 and 0x60000000, SRAM on 0x80000000). Then UPM A is 3101programmed for SDRAM access. Using the temporary configuration, a 3102simple memory test is run that determines the size of the SDRAM 3103banks. 3104 3105When there is more than one SDRAM bank, and the banks are of 3106different size, the largest is mapped first. For equal size, the first 3107bank (CS2#) is mapped first. The first mapping is always for address 31080x00000000, with any additional banks following immediately to create 3109contiguous memory starting from 0. 3110 3111Then, the monitor installs itself at the upper end of the SDRAM area 3112and allocates memory for use by malloc() and for the global Board 3113Info data; also, the exception vector code is copied to the low RAM 3114pages, and the final stack is set up. 3115 3116Only after this relocation will you have a "normal" C environment; 3117until that you are restricted in several ways, mostly because you are 3118running from ROM, and because the code will have to be relocated to a 3119new address in RAM. 3120 3121 3122U-Boot Porting Guide: 3123---------------------- 3124 3125[Based on messages by Jerry Van Baren in the U-Boot-Users mailing 3126list, October 2002] 3127 3128 3129int main (int argc, char *argv[]) 3130{ 3131 sighandler_t no_more_time; 3132 3133 signal (SIGALRM, no_more_time); 3134 alarm (PROJECT_DEADLINE - toSec (3 * WEEK)); 3135 3136 if (available_money > available_manpower) { 3137 pay consultant to port U-Boot; 3138 return 0; 3139 } 3140 3141 Download latest U-Boot source; 3142 3143 Subscribe to u-boot-users mailing list; 3144 3145 if (clueless) { 3146 email ("Hi, I am new to U-Boot, how do I get started?"); 3147 } 3148 3149 while (learning) { 3150 Read the README file in the top level directory; 3151 Read http://www.denx.de/twiki/bin/view/DULG/Manual ; 3152 Read the source, Luke; 3153 } 3154 3155 if (available_money > toLocalCurrency ($2500)) { 3156 Buy a BDI2000; 3157 } else { 3158 Add a lot of aggravation and time; 3159 } 3160 3161 Create your own board support subdirectory; 3162 3163 Create your own board config file; 3164 3165 while (!running) { 3166 do { 3167 Add / modify source code; 3168 } until (compiles); 3169 Debug; 3170 if (clueless) 3171 email ("Hi, I am having problems..."); 3172 } 3173 Send patch file to Wolfgang; 3174 3175 return 0; 3176} 3177 3178void no_more_time (int sig) 3179{ 3180 hire_a_guru(); 3181} 3182 3183 3184Coding Standards: 3185----------------- 3186 3187All contributions to U-Boot should conform to the Linux kernel 3188coding style; see the file "Documentation/CodingStyle" in your Linux 3189kernel source directory. 3190 3191Please note that U-Boot is implemented in C (and to some small parts 3192in Assembler); no C++ is used, so please do not use C++ style 3193comments (//) in your code. 3194 3195Please also stick to the following formatting rules: 3196- remove any trailing white space 3197- use TAB characters for indentation, not spaces 3198- make sure NOT to use DOS '\r\n' line feeds 3199- do not add more than 2 empty lines to source files 3200- do not add trailing empty lines to source files 3201 3202Submissions which do not conform to the standards may be returned 3203with a request to reformat the changes. 3204 3205 3206Submitting Patches: 3207------------------- 3208 3209Since the number of patches for U-Boot is growing, we need to 3210establish some rules. Submissions which do not conform to these rules 3211may be rejected, even when they contain important and valuable stuff. 3212 3213 3214When you send a patch, please include the following information with 3215it: 3216 3217* For bug fixes: a description of the bug and how your patch fixes 3218 this bug. Please try to include a way of demonstrating that the 3219 patch actually fixes something. 3220 3221* For new features: a description of the feature and your 3222 implementation. 3223 3224* A CHANGELOG entry as plaintext (separate from the patch) 3225 3226* For major contributions, your entry to the CREDITS file 3227 3228* When you add support for a new board, don't forget to add this 3229 board to the MAKEALL script, too. 3230 3231* If your patch adds new configuration options, don't forget to 3232 document these in the README file. 3233 3234* The patch itself. If you are accessing the CVS repository use "cvs 3235 update; cvs diff -puRN"; else, use "diff -purN OLD NEW". If your 3236 version of diff does not support these options, then get the latest 3237 version of GNU diff. 3238 3239 The current directory when running this command shall be the top 3240 level directory of the U-Boot source tree, or it's parent directory 3241 (i. e. please make sure that your patch includes sufficient 3242 directory information for the affected files). 3243 3244 We accept patches as plain text, MIME attachments or as uuencoded 3245 gzipped text. 3246 3247* If one logical set of modifications affects or creates several 3248 files, all these changes shall be submitted in a SINGLE patch file. 3249 3250* Changesets that contain different, unrelated modifications shall be 3251 submitted as SEPARATE patches, one patch per changeset. 3252 3253 3254Notes: 3255 3256* Before sending the patch, run the MAKEALL script on your patched 3257 source tree and make sure that no errors or warnings are reported 3258 for any of the boards. 3259 3260* Keep your modifications to the necessary minimum: A patch 3261 containing several unrelated changes or arbitrary reformats will be 3262 returned with a request to re-formatting / split it. 3263 3264* If you modify existing code, make sure that your new code does not 3265 add to the memory footprint of the code ;-) Small is beautiful! 3266 When adding new features, these should compile conditionally only 3267 (using #ifdef), and the resulting code with the new feature 3268 disabled must not need more memory than the old code without your 3269 modification. 3270