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- Show boot progress: 1414 CONFIG_SHOW_BOOT_PROGRESS 1415 1416 Defining this option allows to add some board- 1417 specific code (calling a user-provided function 1418 "show_boot_progress(int)") that enables you to show 1419 the system's boot progress on some display (for 1420 example, some LED's) on your board. At the moment, 1421 the following checkpoints are implemented: 1422 1423 Arg Where When 1424 1 common/cmd_bootm.c before attempting to boot an image 1425 -1 common/cmd_bootm.c Image header has bad magic number 1426 2 common/cmd_bootm.c Image header has correct magic number 1427 -2 common/cmd_bootm.c Image header has bad checksum 1428 3 common/cmd_bootm.c Image header has correct checksum 1429 -3 common/cmd_bootm.c Image data has bad checksum 1430 4 common/cmd_bootm.c Image data has correct checksum 1431 -4 common/cmd_bootm.c Image is for unsupported architecture 1432 5 common/cmd_bootm.c Architecture check OK 1433 -5 common/cmd_bootm.c Wrong Image Type (not kernel, multi, standalone) 1434 6 common/cmd_bootm.c Image Type check OK 1435 -6 common/cmd_bootm.c gunzip uncompression error 1436 -7 common/cmd_bootm.c Unimplemented compression type 1437 7 common/cmd_bootm.c Uncompression OK 1438 -8 common/cmd_bootm.c Wrong Image Type (not kernel, multi, standalone) 1439 8 common/cmd_bootm.c Image Type check OK 1440 -9 common/cmd_bootm.c Unsupported OS (not Linux, BSD, VxWorks, QNX) 1441 9 common/cmd_bootm.c Start initial ramdisk verification 1442 -10 common/cmd_bootm.c Ramdisk header has bad magic number 1443 -11 common/cmd_bootm.c Ramdisk header has bad checksum 1444 10 common/cmd_bootm.c Ramdisk header is OK 1445 -12 common/cmd_bootm.c Ramdisk data has bad checksum 1446 11 common/cmd_bootm.c Ramdisk data has correct checksum 1447 12 common/cmd_bootm.c Ramdisk verification complete, start loading 1448 -13 common/cmd_bootm.c Wrong Image Type (not PPC Linux Ramdisk) 1449 13 common/cmd_bootm.c Start multifile image verification 1450 14 common/cmd_bootm.c No initial ramdisk, no multifile, continue. 1451 15 common/cmd_bootm.c All preparation done, transferring control to OS 1452 1453 -1 common/cmd_doc.c Bad usage of "doc" command 1454 -1 common/cmd_doc.c No boot device 1455 -1 common/cmd_doc.c Unknown Chip ID on boot device 1456 -1 common/cmd_doc.c Read Error on boot device 1457 -1 common/cmd_doc.c Image header has bad magic number 1458 1459 -1 common/cmd_ide.c Bad usage of "ide" command 1460 -1 common/cmd_ide.c No boot device 1461 -1 common/cmd_ide.c Unknown boot device 1462 -1 common/cmd_ide.c Unknown partition table 1463 -1 common/cmd_ide.c Invalid partition type 1464 -1 common/cmd_ide.c Read Error on boot device 1465 -1 common/cmd_ide.c Image header has bad magic number 1466 1467 -1 common/cmd_nand.c Bad usage of "nand" command 1468 -1 common/cmd_nand.c No boot device 1469 -1 common/cmd_nand.c Unknown Chip ID on boot device 1470 -1 common/cmd_nand.c Read Error on boot device 1471 -1 common/cmd_nand.c Image header has bad magic number 1472 1473 -1 common/env_common.c Environment has a bad CRC, using default 1474 1475 1476Modem Support: 1477-------------- 1478 1479[so far only for SMDK2400 and TRAB boards] 1480 1481- Modem support endable: 1482 CONFIG_MODEM_SUPPORT 1483 1484- RTS/CTS Flow control enable: 1485 CONFIG_HWFLOW 1486 1487- Modem debug support: 1488 CONFIG_MODEM_SUPPORT_DEBUG 1489 1490 Enables debugging stuff (char screen[1024], dbg()) 1491 for modem support. Useful only with BDI2000. 1492 1493- Interrupt support (PPC): 1494 1495 There are common interrupt_init() and timer_interrupt() 1496 for all PPC archs. interrupt_init() calls interrupt_init_cpu() 1497 for cpu specific initialization. interrupt_init_cpu() 1498 should set decrementer_count to appropriate value. If 1499 cpu resets decrementer automatically after interrupt 1500 (ppc4xx) it should set decrementer_count to zero. 1501 timer_interrupt() calls timer_interrupt_cpu() for cpu 1502 specific handling. If board has watchdog / status_led 1503 / other_activity_monitor it works automatically from 1504 general timer_interrupt(). 1505 1506- General: 1507 1508 In the target system modem support is enabled when a 1509 specific key (key combination) is pressed during 1510 power-on. Otherwise U-Boot will boot normally 1511 (autoboot). The key_pressed() fuction is called from 1512 board_init(). Currently key_pressed() is a dummy 1513 function, returning 1 and thus enabling modem 1514 initialization. 1515 1516 If there are no modem init strings in the 1517 environment, U-Boot proceed to autoboot; the 1518 previous output (banner, info printfs) will be 1519 supressed, though. 1520 1521 See also: doc/README.Modem 1522 1523 1524Configuration Settings: 1525----------------------- 1526 1527- CFG_LONGHELP: Defined when you want long help messages included; 1528 undefine this when you're short of memory. 1529 1530- CFG_PROMPT: This is what U-Boot prints on the console to 1531 prompt for user input. 1532 1533- CFG_CBSIZE: Buffer size for input from the Console 1534 1535- CFG_PBSIZE: Buffer size for Console output 1536 1537- CFG_MAXARGS: max. Number of arguments accepted for monitor commands 1538 1539- CFG_BARGSIZE: Buffer size for Boot Arguments which are passed to 1540 the application (usually a Linux kernel) when it is 1541 booted 1542 1543- CFG_BAUDRATE_TABLE: 1544 List of legal baudrate settings for this board. 1545 1546- CFG_CONSOLE_INFO_QUIET 1547 Suppress display of console information at boot. 1548 1549- CFG_CONSOLE_IS_IN_ENV 1550 If the board specific function 1551 extern int overwrite_console (void); 1552 returns 1, the stdin, stderr and stdout are switched to the 1553 serial port, else the settings in the environment are used. 1554 1555- CFG_CONSOLE_OVERWRITE_ROUTINE 1556 Enable the call to overwrite_console(). 1557 1558- CFG_CONSOLE_ENV_OVERWRITE 1559 Enable overwrite of previous console environment settings. 1560 1561- CFG_MEMTEST_START, CFG_MEMTEST_END: 1562 Begin and End addresses of the area used by the 1563 simple memory test. 1564 1565- CFG_ALT_MEMTEST: 1566 Enable an alternate, more extensive memory test. 1567 1568- CFG_MEMTEST_SCRATCH: 1569 Scratch address used by the alternate memory test 1570 You only need to set this if address zero isn't writeable 1571 1572- CFG_TFTP_LOADADDR: 1573 Default load address for network file downloads 1574 1575- CFG_LOADS_BAUD_CHANGE: 1576 Enable temporary baudrate change while serial download 1577 1578- CFG_SDRAM_BASE: 1579 Physical start address of SDRAM. _Must_ be 0 here. 1580 1581- CFG_MBIO_BASE: 1582 Physical start address of Motherboard I/O (if using a 1583 Cogent motherboard) 1584 1585- CFG_FLASH_BASE: 1586 Physical start address of Flash memory. 1587 1588- CFG_MONITOR_BASE: 1589 Physical start address of boot monitor code (set by 1590 make config files to be same as the text base address 1591 (TEXT_BASE) used when linking) - same as 1592 CFG_FLASH_BASE when booting from flash. 1593 1594- CFG_MONITOR_LEN: 1595 Size of memory reserved for monitor code, used to 1596 determine _at_compile_time_ (!) if the environment is 1597 embedded within the U-Boot image, or in a separate 1598 flash sector. 1599 1600- CFG_MALLOC_LEN: 1601 Size of DRAM reserved for malloc() use. 1602 1603- CFG_BOOTMAPSZ: 1604 Maximum size of memory mapped by the startup code of 1605 the Linux kernel; all data that must be processed by 1606 the Linux kernel (bd_info, boot arguments, eventually 1607 initrd image) must be put below this limit. 1608 1609- CFG_MAX_FLASH_BANKS: 1610 Max number of Flash memory banks 1611 1612- CFG_MAX_FLASH_SECT: 1613 Max number of sectors on a Flash chip 1614 1615- CFG_FLASH_ERASE_TOUT: 1616 Timeout for Flash erase operations (in ms) 1617 1618- CFG_FLASH_WRITE_TOUT: 1619 Timeout for Flash write operations (in ms) 1620 1621- CFG_FLASH_LOCK_TOUT 1622 Timeout for Flash set sector lock bit operation (in ms) 1623 1624- CFG_FLASH_UNLOCK_TOUT 1625 Timeout for Flash clear lock bits operation (in ms) 1626 1627- CFG_FLASH_PROTECTION 1628 If defined, hardware flash sectors protection is used 1629 instead of U-Boot software protection. 1630 1631- CFG_DIRECT_FLASH_TFTP: 1632 1633 Enable TFTP transfers directly to flash memory; 1634 without this option such a download has to be 1635 performed in two steps: (1) download to RAM, and (2) 1636 copy from RAM to flash. 1637 1638 The two-step approach is usually more reliable, since 1639 you can check if the download worked before you erase 1640 the flash, but in some situations (when sytem RAM is 1641 too limited to allow for a tempory copy of the 1642 downloaded image) this option may be very useful. 1643 1644- CFG_FLASH_CFI: 1645 Define if the flash driver uses extra elements in the 1646 common flash structure for storing flash geometry 1647 1648- CFG_RX_ETH_BUFFER: 1649 Defines the number of ethernet receive buffers. On some 1650 ethernet controllers it is recommended to set this value 1651 to 8 or even higher (EEPRO100 or 405 EMAC), since all 1652 buffers can be full shortly after enabling the interface 1653 on high ethernet traffic. 1654 Defaults to 4 if not defined. 1655 1656The following definitions that deal with the placement and management 1657of environment data (variable area); in general, we support the 1658following configurations: 1659 1660- CFG_ENV_IS_IN_FLASH: 1661 1662 Define this if the environment is in flash memory. 1663 1664 a) The environment occupies one whole flash sector, which is 1665 "embedded" in the text segment with the U-Boot code. This 1666 happens usually with "bottom boot sector" or "top boot 1667 sector" type flash chips, which have several smaller 1668 sectors at the start or the end. For instance, such a 1669 layout can have sector sizes of 8, 2x4, 16, Nx32 kB. In 1670 such a case you would place the environment in one of the 1671 4 kB sectors - with U-Boot code before and after it. With 1672 "top boot sector" type flash chips, you would put the 1673 environment in one of the last sectors, leaving a gap 1674 between U-Boot and the environment. 1675 1676 - CFG_ENV_OFFSET: 1677 1678 Offset of environment data (variable area) to the 1679 beginning of flash memory; for instance, with bottom boot 1680 type flash chips the second sector can be used: the offset 1681 for this sector is given here. 1682 1683 CFG_ENV_OFFSET is used relative to CFG_FLASH_BASE. 1684 1685 - CFG_ENV_ADDR: 1686 1687 This is just another way to specify the start address of 1688 the flash sector containing the environment (instead of 1689 CFG_ENV_OFFSET). 1690 1691 - CFG_ENV_SECT_SIZE: 1692 1693 Size of the sector containing the environment. 1694 1695 1696 b) Sometimes flash chips have few, equal sized, BIG sectors. 1697 In such a case you don't want to spend a whole sector for 1698 the environment. 1699 1700 - CFG_ENV_SIZE: 1701 1702 If you use this in combination with CFG_ENV_IS_IN_FLASH 1703 and CFG_ENV_SECT_SIZE, you can specify to use only a part 1704 of this flash sector for the environment. This saves 1705 memory for the RAM copy of the environment. 1706 1707 It may also save flash memory if you decide to use this 1708 when your environment is "embedded" within U-Boot code, 1709 since then the remainder of the flash sector could be used 1710 for U-Boot code. It should be pointed out that this is 1711 STRONGLY DISCOURAGED from a robustness point of view: 1712 updating the environment in flash makes it always 1713 necessary to erase the WHOLE sector. If something goes 1714 wrong before the contents has been restored from a copy in 1715 RAM, your target system will be dead. 1716 1717 - CFG_ENV_ADDR_REDUND 1718 CFG_ENV_SIZE_REDUND 1719 1720 These settings describe a second storage area used to hold 1721 a redundand copy of the environment data, so that there is 1722 a valid backup copy in case there is a power failure during 1723 a "saveenv" operation. 1724 1725BE CAREFUL! Any changes to the flash layout, and some changes to the 1726source code will make it necessary to adapt <board>/u-boot.lds* 1727accordingly! 1728 1729 1730- CFG_ENV_IS_IN_NVRAM: 1731 1732 Define this if you have some non-volatile memory device 1733 (NVRAM, battery buffered SRAM) which you want to use for the 1734 environment. 1735 1736 - CFG_ENV_ADDR: 1737 - CFG_ENV_SIZE: 1738 1739 These two #defines are used to determin the memory area you 1740 want to use for environment. It is assumed that this memory 1741 can just be read and written to, without any special 1742 provision. 1743 1744BE CAREFUL! The first access to the environment happens quite early 1745in U-Boot initalization (when we try to get the setting of for the 1746console baudrate). You *MUST* have mappend your NVRAM area then, or 1747U-Boot will hang. 1748 1749Please note that even with NVRAM we still use a copy of the 1750environment in RAM: we could work on NVRAM directly, but we want to 1751keep settings there always unmodified except somebody uses "saveenv" 1752to save the current settings. 1753 1754 1755- CFG_ENV_IS_IN_EEPROM: 1756 1757 Use this if you have an EEPROM or similar serial access 1758 device and a driver for it. 1759 1760 - CFG_ENV_OFFSET: 1761 - CFG_ENV_SIZE: 1762 1763 These two #defines specify the offset and size of the 1764 environment area within the total memory of your EEPROM. 1765 1766 - CFG_I2C_EEPROM_ADDR: 1767 If defined, specified the chip address of the EEPROM device. 1768 The default address is zero. 1769 1770 - CFG_EEPROM_PAGE_WRITE_BITS: 1771 If defined, the number of bits used to address bytes in a 1772 single page in the EEPROM device. A 64 byte page, for example 1773 would require six bits. 1774 1775 - CFG_EEPROM_PAGE_WRITE_DELAY_MS: 1776 If defined, the number of milliseconds to delay between 1777 page writes. The default is zero milliseconds. 1778 1779 - CFG_I2C_EEPROM_ADDR_LEN: 1780 The length in bytes of the EEPROM memory array address. Note 1781 that this is NOT the chip address length! 1782 1783 - CFG_EEPROM_SIZE: 1784 The size in bytes of the EEPROM device. 1785 1786 1787- CFG_ENV_IS_IN_DATAFLASH: 1788 1789 Define this if you have a DataFlash memory device which you 1790 want to use for the environment. 1791 1792 - CFG_ENV_OFFSET: 1793 - CFG_ENV_ADDR: 1794 - CFG_ENV_SIZE: 1795 1796 These three #defines specify the offset and size of the 1797 environment area within the total memory of your DataFlash placed 1798 at the specified address. 1799 1800 1801- CFG_SPI_INIT_OFFSET 1802 1803 Defines offset to the initial SPI buffer area in DPRAM. The 1804 area is used at an early stage (ROM part) if the environment 1805 is configured to reside in the SPI EEPROM: We need a 520 byte 1806 scratch DPRAM area. It is used between the two initialization 1807 calls (spi_init_f() and spi_init_r()). A value of 0xB00 seems 1808 to be a good choice since it makes it far enough from the 1809 start of the data area as well as from the stack pointer. 1810 1811Please note that the environment is read-only as long as the monitor 1812has been relocated to RAM and a RAM copy of the environment has been 1813created; also, when using EEPROM you will have to use getenv_r() 1814until then to read environment variables. 1815 1816The environment is protected by a CRC32 checksum. Before the monitor 1817is relocated into RAM, as a result of a bad CRC you will be working 1818with the compiled-in default environment - *silently*!!! [This is 1819necessary, because the first environment variable we need is the 1820"baudrate" setting for the console - if we have a bad CRC, we don't 1821have any device yet where we could complain.] 1822 1823Note: once the monitor has been relocated, then it will complain if 1824the default environment is used; a new CRC is computed as soon as you 1825use the "saveenv" command to store a valid environment. 1826 1827- CFG_FAULT_ECHO_LINK_DOWN: 1828 Echo the inverted Ethernet link state to the fault LED. 1829 1830 Note: If this option is active, then CFG_FAULT_MII_ADDR 1831 also needs to be defined. 1832 1833- CFG_FAULT_MII_ADDR: 1834 MII address of the PHY to check for the Ethernet link state. 1835 1836Low Level (hardware related) configuration options: 1837--------------------------------------------------- 1838 1839- CFG_CACHELINE_SIZE: 1840 Cache Line Size of the CPU. 1841 1842- CFG_DEFAULT_IMMR: 1843 Default address of the IMMR after system reset. 1844 1845 Needed on some 8260 systems (MPC8260ADS, PQ2FADS-ZU, 1846 and RPXsuper) to be able to adjust the position of 1847 the IMMR register after a reset. 1848 1849- Floppy Disk Support: 1850 CFG_FDC_DRIVE_NUMBER 1851 1852 the default drive number (default value 0) 1853 1854 CFG_ISA_IO_STRIDE 1855 1856 defines the spacing between fdc chipset registers 1857 (default value 1) 1858 1859 CFG_ISA_IO_OFFSET 1860 1861 defines the offset of register from address. It 1862 depends on which part of the data bus is connected to 1863 the fdc chipset. (default value 0) 1864 1865 If CFG_ISA_IO_STRIDE CFG_ISA_IO_OFFSET and 1866 CFG_FDC_DRIVE_NUMBER are undefined, they take their 1867 default value. 1868 1869 if CFG_FDC_HW_INIT is defined, then the function 1870 fdc_hw_init() is called at the beginning of the FDC 1871 setup. fdc_hw_init() must be provided by the board 1872 source code. It is used to make hardware dependant 1873 initializations. 1874 1875- CFG_IMMR: Physical address of the Internal Memory Mapped 1876 Register; DO NOT CHANGE! (11-4) 1877 [MPC8xx systems only] 1878 1879- CFG_INIT_RAM_ADDR: 1880 1881 Start address of memory area that can be used for 1882 initial data and stack; please note that this must be 1883 writable memory that is working WITHOUT special 1884 initialization, i. e. you CANNOT use normal RAM which 1885 will become available only after programming the 1886 memory controller and running certain initialization 1887 sequences. 1888 1889 U-Boot uses the following memory types: 1890 - MPC8xx and MPC8260: IMMR (internal memory of the CPU) 1891 - MPC824X: data cache 1892 - PPC4xx: data cache 1893 1894- CFG_GBL_DATA_OFFSET: 1895 1896 Offset of the initial data structure in the memory 1897 area defined by CFG_INIT_RAM_ADDR. Usually 1898 CFG_GBL_DATA_OFFSET is chosen such that the initial 1899 data is located at the end of the available space 1900 (sometimes written as (CFG_INIT_RAM_END - 1901 CFG_INIT_DATA_SIZE), and the initial stack is just 1902 below that area (growing from (CFG_INIT_RAM_ADDR + 1903 CFG_GBL_DATA_OFFSET) downward. 1904 1905 Note: 1906 On the MPC824X (or other systems that use the data 1907 cache for initial memory) the address chosen for 1908 CFG_INIT_RAM_ADDR is basically arbitrary - it must 1909 point to an otherwise UNUSED address space between 1910 the top of RAM and the start of the PCI space. 1911 1912- CFG_SIUMCR: SIU Module Configuration (11-6) 1913 1914- CFG_SYPCR: System Protection Control (11-9) 1915 1916- CFG_TBSCR: Time Base Status and Control (11-26) 1917 1918- CFG_PISCR: Periodic Interrupt Status and Control (11-31) 1919 1920- CFG_PLPRCR: PLL, Low-Power, and Reset Control Register (15-30) 1921 1922- CFG_SCCR: System Clock and reset Control Register (15-27) 1923 1924- CFG_OR_TIMING_SDRAM: 1925 SDRAM timing 1926 1927- CFG_MAMR_PTA: 1928 periodic timer for refresh 1929 1930- CFG_DER: Debug Event Register (37-47) 1931 1932- FLASH_BASE0_PRELIM, FLASH_BASE1_PRELIM, CFG_REMAP_OR_AM, 1933 CFG_PRELIM_OR_AM, CFG_OR_TIMING_FLASH, CFG_OR0_REMAP, 1934 CFG_OR0_PRELIM, CFG_BR0_PRELIM, CFG_OR1_REMAP, CFG_OR1_PRELIM, 1935 CFG_BR1_PRELIM: 1936 Memory Controller Definitions: BR0/1 and OR0/1 (FLASH) 1937 1938- SDRAM_BASE2_PRELIM, SDRAM_BASE3_PRELIM, SDRAM_MAX_SIZE, 1939 CFG_OR_TIMING_SDRAM, CFG_OR2_PRELIM, CFG_BR2_PRELIM, 1940 CFG_OR3_PRELIM, CFG_BR3_PRELIM: 1941 Memory Controller Definitions: BR2/3 and OR2/3 (SDRAM) 1942 1943- CFG_MAMR_PTA, CFG_MPTPR_2BK_4K, CFG_MPTPR_1BK_4K, CFG_MPTPR_2BK_8K, 1944 CFG_MPTPR_1BK_8K, CFG_MAMR_8COL, CFG_MAMR_9COL: 1945 Machine Mode Register and Memory Periodic Timer 1946 Prescaler definitions (SDRAM timing) 1947 1948- CFG_I2C_UCODE_PATCH, CFG_I2C_DPMEM_OFFSET [0x1FC0]: 1949 enable I2C microcode relocation patch (MPC8xx); 1950 define relocation offset in DPRAM [DSP2] 1951 1952- CFG_SPI_UCODE_PATCH, CFG_SPI_DPMEM_OFFSET [0x1FC0]: 1953 enable SPI microcode relocation patch (MPC8xx); 1954 define relocation offset in DPRAM [SCC4] 1955 1956- CFG_USE_OSCCLK: 1957 Use OSCM clock mode on MBX8xx board. Be careful, 1958 wrong setting might damage your board. Read 1959 doc/README.MBX before setting this variable! 1960 1961- CFG_CPM_POST_WORD_ADDR: (MPC8xx, MPC8260 only) 1962 Offset of the bootmode word in DPRAM used by post 1963 (Power On Self Tests). This definition overrides 1964 #define'd default value in commproc.h resp. 1965 cpm_8260.h. 1966 1967- CFG_PCI_SLV_MEM_LOCAL, CFG_PCI_SLV_MEM_BUS, CFG_PICMR0_MASK_ATTRIB, 1968 CFG_PCI_MSTR0_LOCAL, CFG_PCIMSK0_MASK, CFG_PCI_MSTR1_LOCAL, 1969 CFG_PCIMSK1_MASK, CFG_PCI_MSTR_MEM_LOCAL, CFG_PCI_MSTR_MEM_BUS, 1970 CFG_CPU_PCI_MEM_START, CFG_PCI_MSTR_MEM_SIZE, CFG_POCMR0_MASK_ATTRIB, 1971 CFG_PCI_MSTR_MEMIO_LOCAL, CFG_PCI_MSTR_MEMIO_BUS, CPU_PCI_MEMIO_START, 1972 CFG_PCI_MSTR_MEMIO_SIZE, CFG_POCMR1_MASK_ATTRIB, CFG_PCI_MSTR_IO_LOCAL, 1973 CFG_PCI_MSTR_IO_BUS, CFG_CPU_PCI_IO_START, CFG_PCI_MSTR_IO_SIZE, 1974 CFG_POCMR2_MASK_ATTRIB: (MPC826x only) 1975 Overrides the default PCI memory map in cpu/mpc8260/pci.c if set. 1976 1977Building the Software: 1978====================== 1979 1980Building U-Boot has been tested in native PPC environments (on a 1981PowerBook G3 running LinuxPPC 2000) and in cross environments 1982(running RedHat 6.x and 7.x Linux on x86, Solaris 2.6 on a SPARC, and 1983NetBSD 1.5 on x86). 1984 1985If you are not using a native PPC environment, it is assumed that you 1986have the GNU cross compiling tools available in your path and named 1987with a prefix of "powerpc-linux-". If this is not the case, (e.g. if 1988you are using Monta Vista's Hard Hat Linux CDK 1.2) you must change 1989the definition of CROSS_COMPILE in Makefile. For HHL on a 4xx CPU, 1990change it to: 1991 1992 CROSS_COMPILE = ppc_4xx- 1993 1994 1995U-Boot is intended to be simple to build. After installing the 1996sources you must configure U-Boot for one specific board type. This 1997is done by typing: 1998 1999 make NAME_config 2000 2001where "NAME_config" is the name of one of the existing 2002configurations; the following names are supported: 2003 2004 ADCIOP_config GTH_config TQM850L_config 2005 ADS860_config IP860_config TQM855L_config 2006 AR405_config IVML24_config TQM860L_config 2007 CANBT_config IVMS8_config WALNUT405_config 2008 CPCI405_config LANTEC_config cogent_common_config 2009 CPCIISER4_config MBX_config cogent_mpc8260_config 2010 CU824_config MBX860T_config cogent_mpc8xx_config 2011 ESTEEM192E_config RPXlite_config hermes_config 2012 ETX094_config RPXsuper_config hymod_config 2013 FADS823_config SM850_config lwmon_config 2014 FADS850SAR_config SPD823TS_config pcu_e_config 2015 FADS860T_config SXNI855T_config rsdproto_config 2016 FPS850L_config Sandpoint8240_config sbc8260_config 2017 GENIETV_config TQM823L_config PIP405_config 2018 GEN860T_config EBONY_config FPS860L_config 2019 ELPT860_config cmi_mpc5xx_config NETVIA_config 2020 at91rm9200dk_config omap1510inn_config MPC8260ADS_config 2021 omap1610inn_config ZPC1900_config MPC8540ADS_config 2022 MPC8560ADS_config QS850_config QS823_config 2023 QS860T_config DUET_ADS_config 2024 2025Note: for some board special configuration names may exist; check if 2026 additional information is available from the board vendor; for 2027 instance, the TQM8xxL systems run normally at 50 MHz and use a 2028 SCC for 10baseT ethernet; there are also systems with 80 MHz 2029 CPU clock, and an optional Fast Ethernet module is available 2030 for CPU's with FEC. You can select such additional "features" 2031 when chosing the configuration, i. e. 2032 2033 make TQM860L_config 2034 - will configure for a plain TQM860L, i. e. 50MHz, no FEC 2035 2036 make TQM860L_FEC_config 2037 - will configure for a TQM860L at 50MHz with FEC for ethernet 2038 2039 make TQM860L_80MHz_config 2040 - will configure for a TQM860L at 80 MHz, with normal 10baseT 2041 interface 2042 2043 make TQM860L_FEC_80MHz_config 2044 - will configure for a TQM860L at 80 MHz with FEC for ethernet 2045 2046 make TQM823L_LCD_config 2047 - will configure for a TQM823L with U-Boot console on LCD 2048 2049 make TQM823L_LCD_80MHz_config 2050 - will configure for a TQM823L at 80 MHz with U-Boot console on LCD 2051 2052 etc. 2053 2054 2055Finally, type "make all", and you should get some working U-Boot 2056images ready for download to / installation on your system: 2057 2058- "u-boot.bin" is a raw binary image 2059- "u-boot" is an image in ELF binary format 2060- "u-boot.srec" is in Motorola S-Record format 2061 2062 2063Please be aware that the Makefiles assume you are using GNU make, so 2064for instance on NetBSD you might need to use "gmake" instead of 2065native "make". 2066 2067 2068If the system board that you have is not listed, then you will need 2069to port U-Boot to your hardware platform. To do this, follow these 2070steps: 2071 20721. Add a new configuration option for your board to the toplevel 2073 "Makefile" and to the "MAKEALL" script, using the existing 2074 entries as examples. Note that here and at many other places 2075 boards and other names are listed in alphabetical sort order. Please 2076 keep this order. 20772. Create a new directory to hold your board specific code. Add any 2078 files you need. In your board directory, you will need at least 2079 the "Makefile", a "<board>.c", "flash.c" and "u-boot.lds". 20803. Create a new configuration file "include/configs/<board>.h" for 2081 your board 20823. If you're porting U-Boot to a new CPU, then also create a new 2083 directory to hold your CPU specific code. Add any files you need. 20844. Run "make <board>_config" with your new name. 20855. Type "make", and you should get a working "u-boot.srec" file 2086 to be installed on your target system. 20876. Debug and solve any problems that might arise. 2088 [Of course, this last step is much harder than it sounds.] 2089 2090 2091Testing of U-Boot Modifications, Ports to New Hardware, etc.: 2092============================================================== 2093 2094If you have modified U-Boot sources (for instance added a new board 2095or support for new devices, a new CPU, etc.) you are expected to 2096provide feedback to the other developers. The feedback normally takes 2097the form of a "patch", i. e. a context diff against a certain (latest 2098official or latest in CVS) version of U-Boot sources. 2099 2100But before you submit such a patch, please verify that your modifi- 2101cation did not break existing code. At least make sure that *ALL* of 2102the supported boards compile WITHOUT ANY compiler warnings. To do so, 2103just run the "MAKEALL" script, which will configure and build U-Boot 2104for ALL supported system. Be warned, this will take a while. You can 2105select which (cross) compiler to use by passing a `CROSS_COMPILE' 2106environment variable to the script, i. e. to use the cross tools from 2107MontaVista's Hard Hat Linux you can type 2108 2109 CROSS_COMPILE=ppc_8xx- MAKEALL 2110 2111or to build on a native PowerPC system you can type 2112 2113 CROSS_COMPILE=' ' MAKEALL 2114 2115See also "U-Boot Porting Guide" below. 2116 2117 2118Monitor Commands - Overview: 2119============================ 2120 2121go - start application at address 'addr' 2122run - run commands in an environment variable 2123bootm - boot application image from memory 2124bootp - boot image via network using BootP/TFTP protocol 2125tftpboot- boot image via network using TFTP protocol 2126 and env variables "ipaddr" and "serverip" 2127 (and eventually "gatewayip") 2128rarpboot- boot image via network using RARP/TFTP protocol 2129diskboot- boot from IDE devicebootd - boot default, i.e., run 'bootcmd' 2130loads - load S-Record file over serial line 2131loadb - load binary file over serial line (kermit mode) 2132md - memory display 2133mm - memory modify (auto-incrementing) 2134nm - memory modify (constant address) 2135mw - memory write (fill) 2136cp - memory copy 2137cmp - memory compare 2138crc32 - checksum calculation 2139imd - i2c memory display 2140imm - i2c memory modify (auto-incrementing) 2141inm - i2c memory modify (constant address) 2142imw - i2c memory write (fill) 2143icrc32 - i2c checksum calculation 2144iprobe - probe to discover valid I2C chip addresses 2145iloop - infinite loop on address range 2146isdram - print SDRAM configuration information 2147sspi - SPI utility commands 2148base - print or set address offset 2149printenv- print environment variables 2150setenv - set environment variables 2151saveenv - save environment variables to persistent storage 2152protect - enable or disable FLASH write protection 2153erase - erase FLASH memory 2154flinfo - print FLASH memory information 2155bdinfo - print Board Info structure 2156iminfo - print header information for application image 2157coninfo - print console devices and informations 2158ide - IDE sub-system 2159loop - infinite loop on address range 2160mtest - simple RAM test 2161icache - enable or disable instruction cache 2162dcache - enable or disable data cache 2163reset - Perform RESET of the CPU 2164echo - echo args to console 2165version - print monitor version 2166help - print online help 2167? - alias for 'help' 2168 2169 2170Monitor Commands - Detailed Description: 2171======================================== 2172 2173TODO. 2174 2175For now: just type "help <command>". 2176 2177 2178Environment Variables: 2179====================== 2180 2181U-Boot supports user configuration using Environment Variables which 2182can be made persistent by saving to Flash memory. 2183 2184Environment Variables are set using "setenv", printed using 2185"printenv", and saved to Flash using "saveenv". Using "setenv" 2186without a value can be used to delete a variable from the 2187environment. As long as you don't save the environment you are 2188working with an in-memory copy. In case the Flash area containing the 2189environment is erased by accident, a default environment is provided. 2190 2191Some configuration options can be set using Environment Variables: 2192 2193 baudrate - see CONFIG_BAUDRATE 2194 2195 bootdelay - see CONFIG_BOOTDELAY 2196 2197 bootcmd - see CONFIG_BOOTCOMMAND 2198 2199 bootargs - Boot arguments when booting an RTOS image 2200 2201 bootfile - Name of the image to load with TFTP 2202 2203 autoload - if set to "no" (any string beginning with 'n'), 2204 "bootp" will just load perform a lookup of the 2205 configuration from the BOOTP server, but not try to 2206 load any image using TFTP 2207 2208 autostart - if set to "yes", an image loaded using the "bootp", 2209 "rarpboot", "tftpboot" or "diskboot" commands will 2210 be automatically started (by internally calling 2211 "bootm") 2212 2213 If set to "no", a standalone image passed to the 2214 "bootm" command will be copied to the load address 2215 (and eventually uncompressed), but NOT be started. 2216 This can be used to load and uncompress arbitrary 2217 data. 2218 2219 initrd_high - restrict positioning of initrd images: 2220 If this variable is not set, initrd images will be 2221 copied to the highest possible address in RAM; this 2222 is usually what you want since it allows for 2223 maximum initrd size. If for some reason you want to 2224 make sure that the initrd image is loaded below the 2225 CFG_BOOTMAPSZ limit, you can set this environment 2226 variable to a value of "no" or "off" or "0". 2227 Alternatively, you can set it to a maximum upper 2228 address to use (U-Boot will still check that it 2229 does not overwrite the U-Boot stack and data). 2230 2231 For instance, when you have a system with 16 MB 2232 RAM, and want to reserve 4 MB from use by Linux, 2233 you can do this by adding "mem=12M" to the value of 2234 the "bootargs" variable. However, now you must make 2235 sure that the initrd image is placed in the first 2236 12 MB as well - this can be done with 2237 2238 setenv initrd_high 00c00000 2239 2240 If you set initrd_high to 0xFFFFFFFF, this is an 2241 indication to U-Boot that all addresses are legal 2242 for the Linux kernel, including addresses in flash 2243 memory. In this case U-Boot will NOT COPY the 2244 ramdisk at all. This may be useful to reduce the 2245 boot time on your system, but requires that this 2246 feature is supported by your Linux kernel. 2247 2248 ipaddr - IP address; needed for tftpboot command 2249 2250 loadaddr - Default load address for commands like "bootp", 2251 "rarpboot", "tftpboot", "loadb" or "diskboot" 2252 2253 loads_echo - see CONFIG_LOADS_ECHO 2254 2255 serverip - TFTP server IP address; needed for tftpboot command 2256 2257 bootretry - see CONFIG_BOOT_RETRY_TIME 2258 2259 bootdelaykey - see CONFIG_AUTOBOOT_DELAY_STR 2260 2261 bootstopkey - see CONFIG_AUTOBOOT_STOP_STR 2262 2263 2264The following environment variables may be used and automatically 2265updated by the network boot commands ("bootp" and "rarpboot"), 2266depending the information provided by your boot server: 2267 2268 bootfile - see above 2269 dnsip - IP address of your Domain Name Server 2270 dnsip2 - IP address of your secondary Domain Name Server 2271 gatewayip - IP address of the Gateway (Router) to use 2272 hostname - Target hostname 2273 ipaddr - see above 2274 netmask - Subnet Mask 2275 rootpath - Pathname of the root filesystem on the NFS server 2276 serverip - see above 2277 2278 2279There are two special Environment Variables: 2280 2281 serial# - contains hardware identification information such 2282 as type string and/or serial number 2283 ethaddr - Ethernet address 2284 2285These variables can be set only once (usually during manufacturing of 2286the board). U-Boot refuses to delete or overwrite these variables 2287once they have been set once. 2288 2289 2290Further special Environment Variables: 2291 2292 ver - Contains the U-Boot version string as printed 2293 with the "version" command. This variable is 2294 readonly (see CONFIG_VERSION_VARIABLE). 2295 2296 2297Please note that changes to some configuration parameters may take 2298only effect after the next boot (yes, that's just like Windoze :-). 2299 2300 2301Command Line Parsing: 2302===================== 2303 2304There are two different command line parsers available with U-Boot: 2305the old "simple" one, and the much more powerful "hush" shell: 2306 2307Old, simple command line parser: 2308-------------------------------- 2309 2310- supports environment variables (through setenv / saveenv commands) 2311- several commands on one line, separated by ';' 2312- variable substitution using "... $(name) ..." syntax 2313- special characters ('$', ';') can be escaped by prefixing with '\', 2314 for example: 2315 setenv bootcmd bootm \$(address) 2316- You can also escape text by enclosing in single apostrophes, for example: 2317 setenv addip 'setenv bootargs $bootargs ip=$ipaddr:$serverip:$gatewayip:$netmask:$hostname::off' 2318 2319Hush shell: 2320----------- 2321 2322- similar to Bourne shell, with control structures like 2323 if...then...else...fi, for...do...done; while...do...done, 2324 until...do...done, ... 2325- supports environment ("global") variables (through setenv / saveenv 2326 commands) and local shell variables (through standard shell syntax 2327 "name=value"); only environment variables can be used with "run" 2328 command 2329 2330General rules: 2331-------------- 2332 2333(1) If a command line (or an environment variable executed by a "run" 2334 command) contains several commands separated by semicolon, and 2335 one of these commands fails, then the remaining commands will be 2336 executed anyway. 2337 2338(2) If you execute several variables with one call to run (i. e. 2339 calling run with a list af variables as arguments), any failing 2340 command will cause "run" to terminate, i. e. the remaining 2341 variables are not executed. 2342 2343Note for Redundant Ethernet Interfaces: 2344======================================= 2345 2346Some boards come with redundant ethernet interfaces; U-Boot supports 2347such configurations and is capable of automatic selection of a 2348"working" interface when needed. MAC assignment works as follows: 2349 2350Network interfaces are numbered eth0, eth1, eth2, ... Corresponding 2351MAC addresses can be stored in the environment as "ethaddr" (=>eth0), 2352"eth1addr" (=>eth1), "eth2addr", ... 2353 2354If the network interface stores some valid MAC address (for instance 2355in SROM), this is used as default address if there is NO correspon- 2356ding setting in the environment; if the corresponding environment 2357variable is set, this overrides the settings in the card; that means: 2358 2359o If the SROM has a valid MAC address, and there is no address in the 2360 environment, the SROM's address is used. 2361 2362o If there is no valid address in the SROM, and a definition in the 2363 environment exists, then the value from the environment variable is 2364 used. 2365 2366o If both the SROM and the environment contain a MAC address, and 2367 both addresses are the same, this MAC address is used. 2368 2369o If both the SROM and the environment contain a MAC address, and the 2370 addresses differ, the value from the environment is used and a 2371 warning is printed. 2372 2373o If neither SROM nor the environment contain a MAC address, an error 2374 is raised. 2375 2376 2377Image Formats: 2378============== 2379 2380The "boot" commands of this monitor operate on "image" files which 2381can be basicly anything, preceeded by a special header; see the 2382definitions in include/image.h for details; basicly, the header 2383defines the following image properties: 2384 2385* Target Operating System (Provisions for OpenBSD, NetBSD, FreeBSD, 2386 4.4BSD, Linux, SVR4, Esix, Solaris, Irix, SCO, Dell, NCR, VxWorks, 2387 LynxOS, pSOS, QNX, RTEMS, ARTOS; 2388 Currently supported: Linux, NetBSD, VxWorks, QNX, RTEMS, ARTOS, LynxOS). 2389* Target CPU Architecture (Provisions for Alpha, ARM, Intel x86, 2390 IA64, MIPS, NIOS, PowerPC, IBM S390, SuperH, Sparc, Sparc 64 Bit; 2391 Currently supported: ARM, Intel x86, MIPS, NIOS, PowerPC). 2392* Compression Type (uncompressed, gzip, bzip2) 2393* Load Address 2394* Entry Point 2395* Image Name 2396* Image Timestamp 2397 2398The header is marked by a special Magic Number, and both the header 2399and the data portions of the image are secured against corruption by 2400CRC32 checksums. 2401 2402 2403Linux Support: 2404============== 2405 2406Although U-Boot should support any OS or standalone application 2407easily, the main focus has always been on Linux during the design of 2408U-Boot. 2409 2410U-Boot includes many features that so far have been part of some 2411special "boot loader" code within the Linux kernel. Also, any 2412"initrd" images to be used are no longer part of one big Linux image; 2413instead, kernel and "initrd" are separate images. This implementation 2414serves several purposes: 2415 2416- the same features can be used for other OS or standalone 2417 applications (for instance: using compressed images to reduce the 2418 Flash memory footprint) 2419 2420- it becomes much easier to port new Linux kernel versions because 2421 lots of low-level, hardware dependent stuff are done by U-Boot 2422 2423- the same Linux kernel image can now be used with different "initrd" 2424 images; of course this also means that different kernel images can 2425 be run with the same "initrd". This makes testing easier (you don't 2426 have to build a new "zImage.initrd" Linux image when you just 2427 change a file in your "initrd"). Also, a field-upgrade of the 2428 software is easier now. 2429 2430 2431Linux HOWTO: 2432============ 2433 2434Porting Linux to U-Boot based systems: 2435--------------------------------------- 2436 2437U-Boot cannot save you from doing all the necessary modifications to 2438configure the Linux device drivers for use with your target hardware 2439(no, we don't intend to provide a full virtual machine interface to 2440Linux :-). 2441 2442But now you can ignore ALL boot loader code (in arch/ppc/mbxboot). 2443 2444Just make sure your machine specific header file (for instance 2445include/asm-ppc/tqm8xx.h) includes the same definition of the Board 2446Information structure as we define in include/u-boot.h, and make 2447sure that your definition of IMAP_ADDR uses the same value as your 2448U-Boot configuration in CFG_IMMR. 2449 2450 2451Configuring the Linux kernel: 2452----------------------------- 2453 2454No specific requirements for U-Boot. Make sure you have some root 2455device (initial ramdisk, NFS) for your target system. 2456 2457 2458Building a Linux Image: 2459----------------------- 2460 2461With U-Boot, "normal" build targets like "zImage" or "bzImage" are 2462not used. If you use recent kernel source, a new build target 2463"uImage" will exist which automatically builds an image usable by 2464U-Boot. Most older kernels also have support for a "pImage" target, 2465which was introduced for our predecessor project PPCBoot and uses a 2466100% compatible format. 2467 2468Example: 2469 2470 make TQM850L_config 2471 make oldconfig 2472 make dep 2473 make uImage 2474 2475The "uImage" build target uses a special tool (in 'tools/mkimage') to 2476encapsulate a compressed Linux kernel image with header information, 2477CRC32 checksum etc. for use with U-Boot. This is what we are doing: 2478 2479* build a standard "vmlinux" kernel image (in ELF binary format): 2480 2481* convert the kernel into a raw binary image: 2482 2483 ${CROSS_COMPILE}-objcopy -O binary \ 2484 -R .note -R .comment \ 2485 -S vmlinux linux.bin 2486 2487* compress the binary image: 2488 2489 gzip -9 linux.bin 2490 2491* package compressed binary image for U-Boot: 2492 2493 mkimage -A ppc -O linux -T kernel -C gzip \ 2494 -a 0 -e 0 -n "Linux Kernel Image" \ 2495 -d linux.bin.gz uImage 2496 2497 2498The "mkimage" tool can also be used to create ramdisk images for use 2499with U-Boot, either separated from the Linux kernel image, or 2500combined into one file. "mkimage" encapsulates the images with a 64 2501byte header containing information about target architecture, 2502operating system, image type, compression method, entry points, time 2503stamp, CRC32 checksums, etc. 2504 2505"mkimage" can be called in two ways: to verify existing images and 2506print the header information, or to build new images. 2507 2508In the first form (with "-l" option) mkimage lists the information 2509contained in the header of an existing U-Boot image; this includes 2510checksum verification: 2511 2512 tools/mkimage -l image 2513 -l ==> list image header information 2514 2515The second form (with "-d" option) is used to build a U-Boot image 2516from a "data file" which is used as image payload: 2517 2518 tools/mkimage -A arch -O os -T type -C comp -a addr -e ep \ 2519 -n name -d data_file image 2520 -A ==> set architecture to 'arch' 2521 -O ==> set operating system to 'os' 2522 -T ==> set image type to 'type' 2523 -C ==> set compression type 'comp' 2524 -a ==> set load address to 'addr' (hex) 2525 -e ==> set entry point to 'ep' (hex) 2526 -n ==> set image name to 'name' 2527 -d ==> use image data from 'datafile' 2528 2529Right now, all Linux kernels use the same load address (0x00000000), 2530but the entry point address depends on the kernel version: 2531 2532- 2.2.x kernels have the entry point at 0x0000000C, 2533- 2.3.x and later kernels have the entry point at 0x00000000. 2534 2535So a typical call to build a U-Boot image would read: 2536 2537 -> tools/mkimage -n '2.4.4 kernel for TQM850L' \ 2538 > -A ppc -O linux -T kernel -C gzip -a 0 -e 0 \ 2539 > -d /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/ppc/coffboot/vmlinux.gz \ 2540 > examples/uImage.TQM850L 2541 Image Name: 2.4.4 kernel for TQM850L 2542 Created: Wed Jul 19 02:34:59 2000 2543 Image Type: PowerPC Linux Kernel Image (gzip compressed) 2544 Data Size: 335725 Bytes = 327.86 kB = 0.32 MB 2545 Load Address: 0x00000000 2546 Entry Point: 0x00000000 2547 2548To verify the contents of the image (or check for corruption): 2549 2550 -> tools/mkimage -l examples/uImage.TQM850L 2551 Image Name: 2.4.4 kernel for TQM850L 2552 Created: Wed Jul 19 02:34:59 2000 2553 Image Type: PowerPC Linux Kernel Image (gzip compressed) 2554 Data Size: 335725 Bytes = 327.86 kB = 0.32 MB 2555 Load Address: 0x00000000 2556 Entry Point: 0x00000000 2557 2558NOTE: for embedded systems where boot time is critical you can trade 2559speed for memory and install an UNCOMPRESSED image instead: this 2560needs more space in Flash, but boots much faster since it does not 2561need to be uncompressed: 2562 2563 -> gunzip /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/ppc/coffboot/vmlinux.gz 2564 -> tools/mkimage -n '2.4.4 kernel for TQM850L' \ 2565 > -A ppc -O linux -T kernel -C none -a 0 -e 0 \ 2566 > -d /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/ppc/coffboot/vmlinux \ 2567 > examples/uImage.TQM850L-uncompressed 2568 Image Name: 2.4.4 kernel for TQM850L 2569 Created: Wed Jul 19 02:34:59 2000 2570 Image Type: PowerPC Linux Kernel Image (uncompressed) 2571 Data Size: 792160 Bytes = 773.59 kB = 0.76 MB 2572 Load Address: 0x00000000 2573 Entry Point: 0x00000000 2574 2575 2576Similar you can build U-Boot images from a 'ramdisk.image.gz' file 2577when your kernel is intended to use an initial ramdisk: 2578 2579 -> tools/mkimage -n 'Simple Ramdisk Image' \ 2580 > -A ppc -O linux -T ramdisk -C gzip \ 2581 > -d /LinuxPPC/images/SIMPLE-ramdisk.image.gz examples/simple-initrd 2582 Image Name: Simple Ramdisk Image 2583 Created: Wed Jan 12 14:01:50 2000 2584 Image Type: PowerPC Linux RAMDisk Image (gzip compressed) 2585 Data Size: 566530 Bytes = 553.25 kB = 0.54 MB 2586 Load Address: 0x00000000 2587 Entry Point: 0x00000000 2588 2589 2590Installing a Linux Image: 2591------------------------- 2592 2593To downloading a U-Boot image over the serial (console) interface, 2594you must convert the image to S-Record format: 2595 2596 objcopy -I binary -O srec examples/image examples/image.srec 2597 2598The 'objcopy' does not understand the information in the U-Boot 2599image header, so the resulting S-Record file will be relative to 2600address 0x00000000. To load it to a given address, you need to 2601specify the target address as 'offset' parameter with the 'loads' 2602command. 2603 2604Example: install the image to address 0x40100000 (which on the 2605TQM8xxL is in the first Flash bank): 2606 2607 => erase 40100000 401FFFFF 2608 2609 .......... done 2610 Erased 8 sectors 2611 2612 => loads 40100000 2613 ## Ready for S-Record download ... 2614 ~>examples/image.srec 2615 1 2 3 4 5 6 7 8 9 10 11 12 13 ... 2616 ... 2617 15989 15990 15991 15992 2618 [file transfer complete] 2619 [connected] 2620 ## Start Addr = 0x00000000 2621 2622 2623You can check the success of the download using the 'iminfo' command; 2624this includes a checksum verification so you can be sure no data 2625corruption happened: 2626 2627 => imi 40100000 2628 2629 ## Checking Image at 40100000 ... 2630 Image Name: 2.2.13 for initrd on TQM850L 2631 Image Type: PowerPC Linux Kernel Image (gzip compressed) 2632 Data Size: 335725 Bytes = 327 kB = 0 MB 2633 Load Address: 00000000 2634 Entry Point: 0000000c 2635 Verifying Checksum ... OK 2636 2637 2638Boot Linux: 2639----------- 2640 2641The "bootm" command is used to boot an application that is stored in 2642memory (RAM or Flash). In case of a Linux kernel image, the contents 2643of the "bootargs" environment variable is passed to the kernel as 2644parameters. You can check and modify this variable using the 2645"printenv" and "setenv" commands: 2646 2647 2648 => printenv bootargs 2649 bootargs=root=/dev/ram 2650 2651 => setenv bootargs root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2 2652 2653 => printenv bootargs 2654 bootargs=root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2 2655 2656 => bootm 40020000 2657 ## Booting Linux kernel at 40020000 ... 2658 Image Name: 2.2.13 for NFS on TQM850L 2659 Image Type: PowerPC Linux Kernel Image (gzip compressed) 2660 Data Size: 381681 Bytes = 372 kB = 0 MB 2661 Load Address: 00000000 2662 Entry Point: 0000000c 2663 Verifying Checksum ... OK 2664 Uncompressing Kernel Image ... OK 2665 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 2666 Boot arguments: root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2 2667 time_init: decrementer frequency = 187500000/60 2668 Calibrating delay loop... 49.77 BogoMIPS 2669 Memory: 15208k available (700k kernel code, 444k data, 32k init) [c0000000,c1000000] 2670 ... 2671 2672If you want to boot a Linux kernel with initial ram disk, you pass 2673the memory addresses of both the kernel and the initrd image (PPBCOOT 2674format!) to the "bootm" command: 2675 2676 => imi 40100000 40200000 2677 2678 ## Checking Image at 40100000 ... 2679 Image Name: 2.2.13 for initrd on TQM850L 2680 Image Type: PowerPC Linux Kernel Image (gzip compressed) 2681 Data Size: 335725 Bytes = 327 kB = 0 MB 2682 Load Address: 00000000 2683 Entry Point: 0000000c 2684 Verifying Checksum ... OK 2685 2686 ## Checking Image at 40200000 ... 2687 Image Name: Simple Ramdisk Image 2688 Image Type: PowerPC Linux RAMDisk Image (gzip compressed) 2689 Data Size: 566530 Bytes = 553 kB = 0 MB 2690 Load Address: 00000000 2691 Entry Point: 00000000 2692 Verifying Checksum ... OK 2693 2694 => bootm 40100000 40200000 2695 ## Booting Linux kernel at 40100000 ... 2696 Image Name: 2.2.13 for initrd on TQM850L 2697 Image Type: PowerPC Linux Kernel Image (gzip compressed) 2698 Data Size: 335725 Bytes = 327 kB = 0 MB 2699 Load Address: 00000000 2700 Entry Point: 0000000c 2701 Verifying Checksum ... OK 2702 Uncompressing Kernel Image ... OK 2703 ## Loading RAMDisk Image at 40200000 ... 2704 Image Name: Simple Ramdisk Image 2705 Image Type: PowerPC Linux RAMDisk Image (gzip compressed) 2706 Data Size: 566530 Bytes = 553 kB = 0 MB 2707 Load Address: 00000000 2708 Entry Point: 00000000 2709 Verifying Checksum ... OK 2710 Loading Ramdisk ... OK 2711 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 2712 Boot arguments: root=/dev/ram 2713 time_init: decrementer frequency = 187500000/60 2714 Calibrating delay loop... 49.77 BogoMIPS 2715 ... 2716 RAMDISK: Compressed image found at block 0 2717 VFS: Mounted root (ext2 filesystem). 2718 2719 bash# 2720 2721More About U-Boot Image Types: 2722------------------------------ 2723 2724U-Boot supports the following image types: 2725 2726 "Standalone Programs" are directly runnable in the environment 2727 provided by U-Boot; it is expected that (if they behave 2728 well) you can continue to work in U-Boot after return from 2729 the Standalone Program. 2730 "OS Kernel Images" are usually images of some Embedded OS which 2731 will take over control completely. Usually these programs 2732 will install their own set of exception handlers, device 2733 drivers, set up the MMU, etc. - this means, that you cannot 2734 expect to re-enter U-Boot except by resetting the CPU. 2735 "RAMDisk Images" are more or less just data blocks, and their 2736 parameters (address, size) are passed to an OS kernel that is 2737 being started. 2738 "Multi-File Images" contain several images, typically an OS 2739 (Linux) kernel image and one or more data images like 2740 RAMDisks. This construct is useful for instance when you want 2741 to boot over the network using BOOTP etc., where the boot 2742 server provides just a single image file, but you want to get 2743 for instance an OS kernel and a RAMDisk image. 2744 2745 "Multi-File Images" start with a list of image sizes, each 2746 image size (in bytes) specified by an "uint32_t" in network 2747 byte order. This list is terminated by an "(uint32_t)0". 2748 Immediately after the terminating 0 follow the images, one by 2749 one, all aligned on "uint32_t" boundaries (size rounded up to 2750 a multiple of 4 bytes). 2751 2752 "Firmware Images" are binary images containing firmware (like 2753 U-Boot or FPGA images) which usually will be programmed to 2754 flash memory. 2755 2756 "Script files" are command sequences that will be executed by 2757 U-Boot's command interpreter; this feature is especially 2758 useful when you configure U-Boot to use a real shell (hush) 2759 as command interpreter. 2760 2761 2762Standalone HOWTO: 2763================= 2764 2765One of the features of U-Boot is that you can dynamically load and 2766run "standalone" applications, which can use some resources of 2767U-Boot like console I/O functions or interrupt services. 2768 2769Two simple examples are included with the sources: 2770 2771"Hello World" Demo: 2772------------------- 2773 2774'examples/hello_world.c' contains a small "Hello World" Demo 2775application; it is automatically compiled when you build U-Boot. 2776It's configured to run at address 0x00040004, so you can play with it 2777like that: 2778 2779 => loads 2780 ## Ready for S-Record download ... 2781 ~>examples/hello_world.srec 2782 1 2 3 4 5 6 7 8 9 10 11 ... 2783 [file transfer complete] 2784 [connected] 2785 ## Start Addr = 0x00040004 2786 2787 => go 40004 Hello World! This is a test. 2788 ## Starting application at 0x00040004 ... 2789 Hello World 2790 argc = 7 2791 argv[0] = "40004" 2792 argv[1] = "Hello" 2793 argv[2] = "World!" 2794 argv[3] = "This" 2795 argv[4] = "is" 2796 argv[5] = "a" 2797 argv[6] = "test." 2798 argv[7] = "<NULL>" 2799 Hit any key to exit ... 2800 2801 ## Application terminated, rc = 0x0 2802 2803Another example, which demonstrates how to register a CPM interrupt 2804handler with the U-Boot code, can be found in 'examples/timer.c'. 2805Here, a CPM timer is set up to generate an interrupt every second. 2806The interrupt service routine is trivial, just printing a '.' 2807character, but this is just a demo program. The application can be 2808controlled by the following keys: 2809 2810 ? - print current values og the CPM Timer registers 2811 b - enable interrupts and start timer 2812 e - stop timer and disable interrupts 2813 q - quit application 2814 2815 => loads 2816 ## Ready for S-Record download ... 2817 ~>examples/timer.srec 2818 1 2 3 4 5 6 7 8 9 10 11 ... 2819 [file transfer complete] 2820 [connected] 2821 ## Start Addr = 0x00040004 2822 2823 => go 40004 2824 ## Starting application at 0x00040004 ... 2825 TIMERS=0xfff00980 2826 Using timer 1 2827 tgcr @ 0xfff00980, tmr @ 0xfff00990, trr @ 0xfff00994, tcr @ 0xfff00998, tcn @ 0xfff0099c, ter @ 0xfff009b0 2828 2829Hit 'b': 2830 [q, b, e, ?] Set interval 1000000 us 2831 Enabling timer 2832Hit '?': 2833 [q, b, e, ?] ........ 2834 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0xef6, ter=0x0 2835Hit '?': 2836 [q, b, e, ?] . 2837 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x2ad4, ter=0x0 2838Hit '?': 2839 [q, b, e, ?] . 2840 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x1efc, ter=0x0 2841Hit '?': 2842 [q, b, e, ?] . 2843 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x169d, ter=0x0 2844Hit 'e': 2845 [q, b, e, ?] ...Stopping timer 2846Hit 'q': 2847 [q, b, e, ?] ## Application terminated, rc = 0x0 2848 2849 2850Minicom warning: 2851================ 2852 2853Over time, many people have reported problems when trying to use the 2854"minicom" terminal emulation program for serial download. I (wd) 2855consider minicom to be broken, and recommend not to use it. Under 2856Unix, I recommend to use C-Kermit for general purpose use (and 2857especially for kermit binary protocol download ("loadb" command), and 2858use "cu" for S-Record download ("loads" command). 2859 2860Nevertheless, if you absolutely want to use it try adding this 2861configuration to your "File transfer protocols" section: 2862 2863 Name Program Name U/D FullScr IO-Red. Multi 2864 X kermit /usr/bin/kermit -i -l %l -s Y U Y N N 2865 Y kermit /usr/bin/kermit -i -l %l -r N D Y N N 2866 2867 2868NetBSD Notes: 2869============= 2870 2871Starting at version 0.9.2, U-Boot supports NetBSD both as host 2872(build U-Boot) and target system (boots NetBSD/mpc8xx). 2873 2874Building requires a cross environment; it is known to work on 2875NetBSD/i386 with the cross-powerpc-netbsd-1.3 package (you will also 2876need gmake since the Makefiles are not compatible with BSD make). 2877Note that the cross-powerpc package does not install include files; 2878attempting to build U-Boot will fail because <machine/ansi.h> is 2879missing. This file has to be installed and patched manually: 2880 2881 # cd /usr/pkg/cross/powerpc-netbsd/include 2882 # mkdir powerpc 2883 # ln -s powerpc machine 2884 # cp /usr/src/sys/arch/powerpc/include/ansi.h powerpc/ansi.h 2885 # ${EDIT} powerpc/ansi.h ## must remove __va_list, _BSD_VA_LIST 2886 2887Native builds *don't* work due to incompatibilities between native 2888and U-Boot include files. 2889 2890Booting assumes that (the first part of) the image booted is a 2891stage-2 loader which in turn loads and then invokes the kernel 2892proper. Loader sources will eventually appear in the NetBSD source 2893tree (probably in sys/arc/mpc8xx/stand/u-boot_stage2/); in the 2894meantime, send mail to bruno@exet-ag.de and/or wd@denx.de for 2895details. 2896 2897 2898Implementation Internals: 2899========================= 2900 2901The following is not intended to be a complete description of every 2902implementation detail. However, it should help to understand the 2903inner workings of U-Boot and make it easier to port it to custom 2904hardware. 2905 2906 2907Initial Stack, Global Data: 2908--------------------------- 2909 2910The implementation of U-Boot is complicated by the fact that U-Boot 2911starts running out of ROM (flash memory), usually without access to 2912system RAM (because the memory controller is not initialized yet). 2913This means that we don't have writable Data or BSS segments, and BSS 2914is not initialized as zero. To be able to get a C environment working 2915at all, we have to allocate at least a minimal stack. Implementation 2916options for this are defined and restricted by the CPU used: Some CPU 2917models provide on-chip memory (like the IMMR area on MPC8xx and 2918MPC826x processors), on others (parts of) the data cache can be 2919locked as (mis-) used as memory, etc. 2920 2921 Chris Hallinan posted a good summary of these issues to the 2922 u-boot-users mailing list: 2923 2924 Subject: RE: [U-Boot-Users] RE: More On Memory Bank x (nothingness)? 2925 From: "Chris Hallinan" <clh@net1plus.com> 2926 Date: Mon, 10 Feb 2003 16:43:46 -0500 (22:43 MET) 2927 ... 2928 2929 Correct me if I'm wrong, folks, but the way I understand it 2930 is this: Using DCACHE as initial RAM for Stack, etc, does not 2931 require any physical RAM backing up the cache. The cleverness 2932 is that the cache is being used as a temporary supply of 2933 necessary storage before the SDRAM controller is setup. It's 2934 beyond the scope of this list to expain the details, but you 2935 can see how this works by studying the cache architecture and 2936 operation in the architecture and processor-specific manuals. 2937 2938 OCM is On Chip Memory, which I believe the 405GP has 4K. It 2939 is another option for the system designer to use as an 2940 initial stack/ram area prior to SDRAM being available. Either 2941 option should work for you. Using CS 4 should be fine if your 2942 board designers haven't used it for something that would 2943 cause you grief during the initial boot! It is frequently not 2944 used. 2945 2946 CFG_INIT_RAM_ADDR should be somewhere that won't interfere 2947 with your processor/board/system design. The default value 2948 you will find in any recent u-boot distribution in 2949 Walnut405.h should work for you. I'd set it to a value larger 2950 than your SDRAM module. If you have a 64MB SDRAM module, set 2951 it above 400_0000. Just make sure your board has no resources 2952 that are supposed to respond to that address! That code in 2953 start.S has been around a while and should work as is when 2954 you get the config right. 2955 2956 -Chris Hallinan 2957 DS4.COM, Inc. 2958 2959It is essential to remember this, since it has some impact on the C 2960code for the initialization procedures: 2961 2962* Initialized global data (data segment) is read-only. Do not attempt 2963 to write it. 2964 2965* Do not use any unitialized global data (or implicitely initialized 2966 as zero data - BSS segment) at all - this is undefined, initiali- 2967 zation is performed later (when relocating to RAM). 2968 2969* Stack space is very limited. Avoid big data buffers or things like 2970 that. 2971 2972Having only the stack as writable memory limits means we cannot use 2973normal global data to share information beween the code. But it 2974turned out that the implementation of U-Boot can be greatly 2975simplified by making a global data structure (gd_t) available to all 2976functions. We could pass a pointer to this data as argument to _all_ 2977functions, but this would bloat the code. Instead we use a feature of 2978the GCC compiler (Global Register Variables) to share the data: we 2979place a pointer (gd) to the global data into a register which we 2980reserve for this purpose. 2981 2982When choosing a register for such a purpose we are restricted by the 2983relevant (E)ABI specifications for the current architecture, and by 2984GCC's implementation. 2985 2986For PowerPC, the following registers have specific use: 2987 R1: stack pointer 2988 R2: TOC pointer 2989 R3-R4: parameter passing and return values 2990 R5-R10: parameter passing 2991 R13: small data area pointer 2992 R30: GOT pointer 2993 R31: frame pointer 2994 2995 (U-Boot also uses R14 as internal GOT pointer.) 2996 2997 ==> U-Boot will use R29 to hold a pointer to the global data 2998 2999 Note: on PPC, we could use a static initializer (since the 3000 address of the global data structure is known at compile time), 3001 but it turned out that reserving a register results in somewhat 3002 smaller code - although the code savings are not that big (on 3003 average for all boards 752 bytes for the whole U-Boot image, 3004 624 text + 127 data). 3005 3006On ARM, the following registers are used: 3007 3008 R0: function argument word/integer result 3009 R1-R3: function argument word 3010 R9: GOT pointer 3011 R10: stack limit (used only if stack checking if enabled) 3012 R11: argument (frame) pointer 3013 R12: temporary workspace 3014 R13: stack pointer 3015 R14: link register 3016 R15: program counter 3017 3018 ==> U-Boot will use R8 to hold a pointer to the global data 3019 3020 3021Memory Management: 3022------------------ 3023 3024U-Boot runs in system state and uses physical addresses, i.e. the 3025MMU is not used either for address mapping nor for memory protection. 3026 3027The available memory is mapped to fixed addresses using the memory 3028controller. In this process, a contiguous block is formed for each 3029memory type (Flash, SDRAM, SRAM), even when it consists of several 3030physical memory banks. 3031 3032U-Boot is installed in the first 128 kB of the first Flash bank (on 3033TQM8xxL modules this is the range 0x40000000 ... 0x4001FFFF). After 3034booting and sizing and initializing DRAM, the code relocates itself 3035to the upper end of DRAM. Immediately below the U-Boot code some 3036memory is reserved for use by malloc() [see CFG_MALLOC_LEN 3037configuration setting]. Below that, a structure with global Board 3038Info data is placed, followed by the stack (growing downward). 3039 3040Additionally, some exception handler code is copied to the low 8 kB 3041of DRAM (0x00000000 ... 0x00001FFF). 3042 3043So a typical memory configuration with 16 MB of DRAM could look like 3044this: 3045 3046 0x0000 0000 Exception Vector code 3047 : 3048 0x0000 1FFF 3049 0x0000 2000 Free for Application Use 3050 : 3051 : 3052 3053 : 3054 : 3055 0x00FB FF20 Monitor Stack (Growing downward) 3056 0x00FB FFAC Board Info Data and permanent copy of global data 3057 0x00FC 0000 Malloc Arena 3058 : 3059 0x00FD FFFF 3060 0x00FE 0000 RAM Copy of Monitor Code 3061 ... eventually: LCD or video framebuffer 3062 ... eventually: pRAM (Protected RAM - unchanged by reset) 3063 0x00FF FFFF [End of RAM] 3064 3065 3066System Initialization: 3067---------------------- 3068 3069In the reset configuration, U-Boot starts at the reset entry point 3070(on most PowerPC systens at address 0x00000100). Because of the reset 3071configuration for CS0# this is a mirror of the onboard Flash memory. 3072To be able to re-map memory U-Boot then jumps to its link address. 3073To be able to implement the initialization code in C, a (small!) 3074initial stack is set up in the internal Dual Ported RAM (in case CPUs 3075which provide such a feature like MPC8xx or MPC8260), or in a locked 3076part of the data cache. After that, U-Boot initializes the CPU core, 3077the caches and the SIU. 3078 3079Next, all (potentially) available memory banks are mapped using a 3080preliminary mapping. For example, we put them on 512 MB boundaries 3081(multiples of 0x20000000: SDRAM on 0x00000000 and 0x20000000, Flash 3082on 0x40000000 and 0x60000000, SRAM on 0x80000000). Then UPM A is 3083programmed for SDRAM access. Using the temporary configuration, a 3084simple memory test is run that determines the size of the SDRAM 3085banks. 3086 3087When there is more than one SDRAM bank, and the banks are of 3088different size, the largest is mapped first. For equal size, the first 3089bank (CS2#) is mapped first. The first mapping is always for address 30900x00000000, with any additional banks following immediately to create 3091contiguous memory starting from 0. 3092 3093Then, the monitor installs itself at the upper end of the SDRAM area 3094and allocates memory for use by malloc() and for the global Board 3095Info data; also, the exception vector code is copied to the low RAM 3096pages, and the final stack is set up. 3097 3098Only after this relocation will you have a "normal" C environment; 3099until that you are restricted in several ways, mostly because you are 3100running from ROM, and because the code will have to be relocated to a 3101new address in RAM. 3102 3103 3104U-Boot Porting Guide: 3105---------------------- 3106 3107[Based on messages by Jerry Van Baren in the U-Boot-Users mailing 3108list, October 2002] 3109 3110 3111int main (int argc, char *argv[]) 3112{ 3113 sighandler_t no_more_time; 3114 3115 signal (SIGALRM, no_more_time); 3116 alarm (PROJECT_DEADLINE - toSec (3 * WEEK)); 3117 3118 if (available_money > available_manpower) { 3119 pay consultant to port U-Boot; 3120 return 0; 3121 } 3122 3123 Download latest U-Boot source; 3124 3125 Subscribe to u-boot-users mailing list; 3126 3127 if (clueless) { 3128 email ("Hi, I am new to U-Boot, how do I get started?"); 3129 } 3130 3131 while (learning) { 3132 Read the README file in the top level directory; 3133 Read http://www.denx.de/twiki/bin/view/DULG/Manual ; 3134 Read the source, Luke; 3135 } 3136 3137 if (available_money > toLocalCurrency ($2500)) { 3138 Buy a BDI2000; 3139 } else { 3140 Add a lot of aggravation and time; 3141 } 3142 3143 Create your own board support subdirectory; 3144 3145 Create your own board config file; 3146 3147 while (!running) { 3148 do { 3149 Add / modify source code; 3150 } until (compiles); 3151 Debug; 3152 if (clueless) 3153 email ("Hi, I am having problems..."); 3154 } 3155 Send patch file to Wolfgang; 3156 3157 return 0; 3158} 3159 3160void no_more_time (int sig) 3161{ 3162 hire_a_guru(); 3163} 3164 3165 3166Coding Standards: 3167----------------- 3168 3169All contributions to U-Boot should conform to the Linux kernel 3170coding style; see the file "Documentation/CodingStyle" in your Linux 3171kernel source directory. 3172 3173Please note that U-Boot is implemented in C (and to some small parts 3174in Assembler); no C++ is used, so please do not use C++ style 3175comments (//) in your code. 3176 3177Please also stick to the following formatting rules: 3178- remove any trailing white space 3179- use TAB characters for indentation, not spaces 3180- make sure NOT to use DOS '\r\n' line feeds 3181- do not add more than 2 empty lines to source files 3182- do not add trailing empty lines to source files 3183 3184Submissions which do not conform to the standards may be returned 3185with a request to reformat the changes. 3186 3187 3188Submitting Patches: 3189------------------- 3190 3191Since the number of patches for U-Boot is growing, we need to 3192establish some rules. Submissions which do not conform to these rules 3193may be rejected, even when they contain important and valuable stuff. 3194 3195 3196When you send a patch, please include the following information with 3197it: 3198 3199* For bug fixes: a description of the bug and how your patch fixes 3200 this bug. Please try to include a way of demonstrating that the 3201 patch actually fixes something. 3202 3203* For new features: a description of the feature and your 3204 implementation. 3205 3206* A CHANGELOG entry as plaintext (separate from the patch) 3207 3208* For major contributions, your entry to the CREDITS file 3209 3210* When you add support for a new board, don't forget to add this 3211 board to the MAKEALL script, too. 3212 3213* If your patch adds new configuration options, don't forget to 3214 document these in the README file. 3215 3216* The patch itself. If you are accessing the CVS repository use "cvs 3217 update; cvs diff -puRN"; else, use "diff -purN OLD NEW". If your 3218 version of diff does not support these options, then get the latest 3219 version of GNU diff. 3220 3221 The current directory when running this command shall be the top 3222 level directory of the U-Boot source tree, or it's parent directory 3223 (i. e. please make sure that your patch includes sufficient 3224 directory information for the affected files). 3225 3226 We accept patches as plain text, MIME attachments or as uuencoded 3227 gzipped text. 3228 3229* If one logical set of modifications affects or creates several 3230 files, all these changes shall be submitted in a SINGLE patch file. 3231 3232* Changesets that contain different, unrelated modifications shall be 3233 submitted as SEPARATE patches, one patch per changeset. 3234 3235 3236Notes: 3237 3238* Before sending the patch, run the MAKEALL script on your patched 3239 source tree and make sure that no errors or warnings are reported 3240 for any of the boards. 3241 3242* Keep your modifications to the necessary minimum: A patch 3243 containing several unrelated changes or arbitrary reformats will be 3244 returned with a request to re-formatting / split it. 3245 3246* If you modify existing code, make sure that your new code does not 3247 add to the memory footprint of the code ;-) Small is beautiful! 3248 When adding new features, these should compile conditionally only 3249 (using #ifdef), and the resulting code with the new feature 3250 disabled must not need more memory than the old code without your 3251 modification. 3252