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 MPC8260ADS and PQ2FADS-ZU 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 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 (untested) 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 8xx 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- Linux Kernel Interface: 425 CONFIG_CLOCKS_IN_MHZ 426 427 U-Boot stores all clock information in Hz 428 internally. For binary compatibility with older Linux 429 kernels (which expect the clocks passed in the 430 bd_info data to be in MHz) the environment variable 431 "clocks_in_mhz" can be defined so that U-Boot 432 converts clock data to MHZ before passing it to the 433 Linux kernel. 434 When CONFIG_CLOCKS_IN_MHZ is defined, a definition of 435 "clocks_in_mhz=1" is automatically included in the 436 default environment. 437 438 CONFIG_MEMSIZE_IN_BYTES [relevant for MIPS only] 439 440 When transfering memsize parameter to linux, some versions 441 expect it to be in bytes, others in MB. 442 Define CONFIG_MEMSIZE_IN_BYTES to make it in bytes. 443 444- Console Interface: 445 Depending on board, define exactly one serial port 446 (like CONFIG_8xx_CONS_SMC1, CONFIG_8xx_CONS_SMC2, 447 CONFIG_8xx_CONS_SCC1, ...), or switch off the serial 448 console by defining CONFIG_8xx_CONS_NONE 449 450 Note: if CONFIG_8xx_CONS_NONE is defined, the serial 451 port routines must be defined elsewhere 452 (i.e. serial_init(), serial_getc(), ...) 453 454 CONFIG_CFB_CONSOLE 455 Enables console device for a color framebuffer. Needs following 456 defines (cf. smiLynxEM, i8042, board/eltec/bab7xx) 457 VIDEO_FB_LITTLE_ENDIAN graphic memory organisation 458 (default big endian) 459 VIDEO_HW_RECTFILL graphic chip supports 460 rectangle fill 461 (cf. smiLynxEM) 462 VIDEO_HW_BITBLT graphic chip supports 463 bit-blit (cf. smiLynxEM) 464 VIDEO_VISIBLE_COLS visible pixel columns 465 (cols=pitch) 466 VIDEO_VISIBLE_ROWS visible pixel rows 467 VIDEO_PIXEL_SIZE bytes per pixel 468 VIDEO_DATA_FORMAT graphic data format 469 (0-5, cf. cfb_console.c) 470 VIDEO_FB_ADRS framebuffer address 471 VIDEO_KBD_INIT_FCT keyboard int fct 472 (i.e. i8042_kbd_init()) 473 VIDEO_TSTC_FCT test char fct 474 (i.e. i8042_tstc) 475 VIDEO_GETC_FCT get char fct 476 (i.e. i8042_getc) 477 CONFIG_CONSOLE_CURSOR cursor drawing on/off 478 (requires blink timer 479 cf. i8042.c) 480 CFG_CONSOLE_BLINK_COUNT blink interval (cf. i8042.c) 481 CONFIG_CONSOLE_TIME display time/date info in 482 upper right corner 483 (requires CFG_CMD_DATE) 484 CONFIG_VIDEO_LOGO display Linux logo in 485 upper left corner 486 CONFIG_VIDEO_BMP_LOGO use bmp_logo.h instead of 487 linux_logo.h for logo. 488 Requires CONFIG_VIDEO_LOGO 489 CONFIG_CONSOLE_EXTRA_INFO 490 addional board info beside 491 the logo 492 493 When CONFIG_CFB_CONSOLE is defined, video console is 494 default i/o. Serial console can be forced with 495 environment 'console=serial'. 496 497 When CONFIG_SILENT_CONSOLE is defined, all console 498 messages (by U-Boot and Linux!) can be silenced with 499 the "silent" environment variable. See 500 doc/README.silent for more information. 501 502- Console Baudrate: 503 CONFIG_BAUDRATE - in bps 504 Select one of the baudrates listed in 505 CFG_BAUDRATE_TABLE, see below. 506 CFG_BRGCLK_PRESCALE, baudrate prescale 507 508- Interrupt driven serial port input: 509 CONFIG_SERIAL_SOFTWARE_FIFO 510 511 PPC405GP only. 512 Use an interrupt handler for receiving data on the 513 serial port. It also enables using hardware handshake 514 (RTS/CTS) and UART's built-in FIFO. Set the number of 515 bytes the interrupt driven input buffer should have. 516 517 Set to 0 to disable this feature (this is the default). 518 This will also disable hardware handshake. 519 520- Console UART Number: 521 CONFIG_UART1_CONSOLE 522 523 IBM PPC4xx only. 524 If defined internal UART1 (and not UART0) is used 525 as default U-Boot console. 526 527- Boot Delay: CONFIG_BOOTDELAY - in seconds 528 Delay before automatically booting the default image; 529 set to -1 to disable autoboot. 530 531 See doc/README.autoboot for these options that 532 work with CONFIG_BOOTDELAY. None are required. 533 CONFIG_BOOT_RETRY_TIME 534 CONFIG_BOOT_RETRY_MIN 535 CONFIG_AUTOBOOT_KEYED 536 CONFIG_AUTOBOOT_PROMPT 537 CONFIG_AUTOBOOT_DELAY_STR 538 CONFIG_AUTOBOOT_STOP_STR 539 CONFIG_AUTOBOOT_DELAY_STR2 540 CONFIG_AUTOBOOT_STOP_STR2 541 CONFIG_ZERO_BOOTDELAY_CHECK 542 CONFIG_RESET_TO_RETRY 543 544- Autoboot Command: 545 CONFIG_BOOTCOMMAND 546 Only needed when CONFIG_BOOTDELAY is enabled; 547 define a command string that is automatically executed 548 when no character is read on the console interface 549 within "Boot Delay" after reset. 550 551 CONFIG_BOOTARGS 552 This can be used to pass arguments to the bootm 553 command. The value of CONFIG_BOOTARGS goes into the 554 environment value "bootargs". 555 556 CONFIG_RAMBOOT and CONFIG_NFSBOOT 557 The value of these goes into the environment as 558 "ramboot" and "nfsboot" respectively, and can be used 559 as a convenience, when switching between booting from 560 ram and nfs. 561 562- Pre-Boot Commands: 563 CONFIG_PREBOOT 564 565 When this option is #defined, the existence of the 566 environment variable "preboot" will be checked 567 immediately before starting the CONFIG_BOOTDELAY 568 countdown and/or running the auto-boot command resp. 569 entering interactive mode. 570 571 This feature is especially useful when "preboot" is 572 automatically generated or modified. For an example 573 see the LWMON board specific code: here "preboot" is 574 modified when the user holds down a certain 575 combination of keys on the (special) keyboard when 576 booting the systems 577 578- Serial Download Echo Mode: 579 CONFIG_LOADS_ECHO 580 If defined to 1, all characters received during a 581 serial download (using the "loads" command) are 582 echoed back. This might be needed by some terminal 583 emulations (like "cu"), but may as well just take 584 time on others. This setting #define's the initial 585 value of the "loads_echo" environment variable. 586 587- Kgdb Serial Baudrate: (if CFG_CMD_KGDB is defined) 588 CONFIG_KGDB_BAUDRATE 589 Select one of the baudrates listed in 590 CFG_BAUDRATE_TABLE, see below. 591 592- Monitor Functions: 593 CONFIG_COMMANDS 594 Most monitor functions can be selected (or 595 de-selected) by adjusting the definition of 596 CONFIG_COMMANDS; to select individual functions, 597 #define CONFIG_COMMANDS by "OR"ing any of the 598 following values: 599 600 #define enables commands: 601 ------------------------- 602 CFG_CMD_ASKENV * ask for env variable 603 CFG_CMD_AUTOSCRIPT Autoscript Support 604 CFG_CMD_BDI bdinfo 605 CFG_CMD_BEDBUG Include BedBug Debugger 606 CFG_CMD_BMP * BMP support 607 CFG_CMD_BOOTD bootd 608 CFG_CMD_CACHE icache, dcache 609 CFG_CMD_CONSOLE coninfo 610 CFG_CMD_DATE * support for RTC, date/time... 611 CFG_CMD_DHCP DHCP support 612 CFG_CMD_DIAG * Diagnostics 613 CFG_CMD_DOC * Disk-On-Chip Support 614 CFG_CMD_DTT Digital Therm and Thermostat 615 CFG_CMD_ECHO * echo arguments 616 CFG_CMD_EEPROM * EEPROM read/write support 617 CFG_CMD_ELF bootelf, bootvx 618 CFG_CMD_ENV saveenv 619 CFG_CMD_FDC * Floppy Disk Support 620 CFG_CMD_FAT FAT partition support 621 CFG_CMD_FDOS * Dos diskette Support 622 CFG_CMD_FLASH flinfo, erase, protect 623 CFG_CMD_FPGA FPGA device initialization support 624 CFG_CMD_HWFLOW * RTS/CTS hw flow control 625 CFG_CMD_I2C * I2C serial bus support 626 CFG_CMD_IDE * IDE harddisk support 627 CFG_CMD_IMI iminfo 628 CFG_CMD_IMLS List all found images 629 CFG_CMD_IMMAP * IMMR dump support 630 CFG_CMD_IRQ * irqinfo 631 CFG_CMD_JFFS2 * JFFS2 Support 632 CFG_CMD_KGDB * kgdb 633 CFG_CMD_LOADB loadb 634 CFG_CMD_LOADS loads 635 CFG_CMD_MEMORY md, mm, nm, mw, cp, cmp, crc, base, 636 loop, mtest 637 CFG_CMD_MISC Misc functions like sleep etc 638 CFG_CMD_MMC MMC memory mapped support 639 CFG_CMD_MII MII utility commands 640 CFG_CMD_NAND * NAND support 641 CFG_CMD_NET bootp, tftpboot, rarpboot 642 CFG_CMD_PCI * pciinfo 643 CFG_CMD_PCMCIA * PCMCIA support 644 CFG_CMD_PING * send ICMP ECHO_REQUEST to network host 645 CFG_CMD_PORTIO * Port I/O 646 CFG_CMD_REGINFO * Register dump 647 CFG_CMD_RUN run command in env variable 648 CFG_CMD_SAVES save S record dump 649 CFG_CMD_SCSI * SCSI Support 650 CFG_CMD_SDRAM * print SDRAM configuration information 651 CFG_CMD_SETGETDCR Support for DCR Register access (4xx only) 652 CFG_CMD_SPI * SPI serial bus support 653 CFG_CMD_USB * USB support 654 CFG_CMD_VFD * VFD support (TRAB) 655 CFG_CMD_BSP * Board SPecific functions 656 ----------------------------------------------- 657 CFG_CMD_ALL all 658 659 CFG_CMD_DFL Default configuration; at the moment 660 this is includes all commands, except 661 the ones marked with "*" in the list 662 above. 663 664 If you don't define CONFIG_COMMANDS it defaults to 665 CFG_CMD_DFL in include/cmd_confdefs.h. A board can 666 override the default settings in the respective 667 include file. 668 669 EXAMPLE: If you want all functions except of network 670 support you can write: 671 672 #define CONFIG_COMMANDS (CFG_CMD_ALL & ~CFG_CMD_NET) 673 674 675 Note: Don't enable the "icache" and "dcache" commands 676 (configuration option CFG_CMD_CACHE) unless you know 677 what you (and your U-Boot users) are doing. Data 678 cache cannot be enabled on systems like the 8xx or 679 8260 (where accesses to the IMMR region must be 680 uncached), and it cannot be disabled on all other 681 systems where we (mis-) use the data cache to hold an 682 initial stack and some data. 683 684 685 XXX - this list needs to get updated! 686 687- Watchdog: 688 CONFIG_WATCHDOG 689 If this variable is defined, it enables watchdog 690 support. There must be support in the platform specific 691 code for a watchdog. For the 8xx and 8260 CPUs, the 692 SIU Watchdog feature is enabled in the SYPCR 693 register. 694 695- U-Boot Version: 696 CONFIG_VERSION_VARIABLE 697 If this variable is defined, an environment variable 698 named "ver" is created by U-Boot showing the U-Boot 699 version as printed by the "version" command. 700 This variable is readonly. 701 702- Real-Time Clock: 703 704 When CFG_CMD_DATE is selected, the type of the RTC 705 has to be selected, too. Define exactly one of the 706 following options: 707 708 CONFIG_RTC_MPC8xx - use internal RTC of MPC8xx 709 CONFIG_RTC_PCF8563 - use Philips PCF8563 RTC 710 CONFIG_RTC_MC146818 - use MC146818 RTC 711 CONFIG_RTC_DS1307 - use Maxim, Inc. DS1307 RTC 712 CONFIG_RTC_DS1337 - use Maxim, Inc. DS1337 RTC 713 CONFIG_RTC_DS1338 - use Maxim, Inc. DS1338 RTC 714 CONFIG_RTC_DS164x - use Dallas DS164x RTC 715 716 Note that if the RTC uses I2C, then the I2C interface 717 must also be configured. See I2C Support, below. 718 719- Timestamp Support: 720 721 When CONFIG_TIMESTAMP is selected, the timestamp 722 (date and time) of an image is printed by image 723 commands like bootm or iminfo. This option is 724 automatically enabled when you select CFG_CMD_DATE . 725 726- Partition Support: 727 CONFIG_MAC_PARTITION and/or CONFIG_DOS_PARTITION 728 and/or CONFIG_ISO_PARTITION 729 730 If IDE or SCSI support is enabled (CFG_CMD_IDE or 731 CFG_CMD_SCSI) you must configure support for at least 732 one partition type as well. 733 734- IDE Reset method: 735 CONFIG_IDE_RESET_ROUTINE 736 737 Set this to define that instead of a reset Pin, the 738 routine ide_set_reset(int idereset) will be used. 739 740- ATAPI Support: 741 CONFIG_ATAPI 742 743 Set this to enable ATAPI support. 744 745- SCSI Support: 746 At the moment only there is only support for the 747 SYM53C8XX SCSI controller; define 748 CONFIG_SCSI_SYM53C8XX to enable it. 749 750 CFG_SCSI_MAX_LUN [8], CFG_SCSI_MAX_SCSI_ID [7] and 751 CFG_SCSI_MAX_DEVICE [CFG_SCSI_MAX_SCSI_ID * 752 CFG_SCSI_MAX_LUN] can be adjusted to define the 753 maximum numbers of LUNs, SCSI ID's and target 754 devices. 755 CFG_SCSI_SYM53C8XX_CCF to fix clock timing (80Mhz) 756 757- NETWORK Support (PCI): 758 CONFIG_E1000 759 Support for Intel 8254x gigabit chips. 760 761 CONFIG_EEPRO100 762 Support for Intel 82557/82559/82559ER chips. 763 Optional CONFIG_EEPRO100_SROM_WRITE enables eeprom 764 write routine for first time initialisation. 765 766 CONFIG_TULIP 767 Support for Digital 2114x chips. 768 Optional CONFIG_TULIP_SELECT_MEDIA for board specific 769 modem chip initialisation (KS8761/QS6611). 770 771 CONFIG_NATSEMI 772 Support for National dp83815 chips. 773 774 CONFIG_NS8382X 775 Support for National dp8382[01] gigabit chips. 776 777- NETWORK Support (other): 778 779 CONFIG_DRIVER_LAN91C96 780 Support for SMSC's LAN91C96 chips. 781 782 CONFIG_LAN91C96_BASE 783 Define this to hold the physical address 784 of the LAN91C96's I/O space 785 786 CONFIG_LAN91C96_USE_32_BIT 787 Define this to enable 32 bit addressing 788 789- USB Support: 790 At the moment only the UHCI host controller is 791 supported (PIP405, MIP405); define 792 CONFIG_USB_UHCI to enable it. 793 define CONFIG_USB_KEYBOARD to enable the USB Keyboard 794 end define CONFIG_USB_STORAGE to enable the USB 795 storage devices. 796 Note: 797 Supported are USB Keyboards and USB Floppy drives 798 (TEAC FD-05PUB). 799 800- MMC Support: 801 The MMC controller on the Intel PXA is supported. To 802 enable this define CONFIG_MMC. The MMC can be 803 accessed from the boot prompt by mapping the device 804 to physical memory similar to flash. Command line is 805 enabled with CFG_CMD_MMC. The MMC driver also works with 806 the FAT fs. This is enabled with CFG_CMD_FAT. 807 808- Keyboard Support: 809 CONFIG_ISA_KEYBOARD 810 811 Define this to enable standard (PC-Style) keyboard 812 support 813 814 CONFIG_I8042_KBD 815 Standard PC keyboard driver with US (is default) and 816 GERMAN key layout (switch via environment 'keymap=de') support. 817 Export function i8042_kbd_init, i8042_tstc and i8042_getc 818 for cfb_console. Supports cursor blinking. 819 820- Video support: 821 CONFIG_VIDEO 822 823 Define this to enable video support (for output to 824 video). 825 826 CONFIG_VIDEO_CT69000 827 828 Enable Chips & Technologies 69000 Video chip 829 830 CONFIG_VIDEO_SMI_LYNXEM 831 Enable Silicon Motion SMI 712/710/810 Video chip 832 Videomode are selected via environment 'videomode' with 833 standard LiLo mode numbers. 834 Following modes are supported (* is default): 835 836 800x600 1024x768 1280x1024 837 256 (8bit) 303* 305 307 838 65536 (16bit) 314 317 31a 839 16,7 Mill (24bit) 315 318 31b 840 (i.e. setenv videomode 317; saveenv; reset;) 841 842 CONFIG_VIDEO_SED13806 843 Enable Epson SED13806 driver. This driver supports 8bpp 844 and 16bpp modes defined by CONFIG_VIDEO_SED13806_8BPP 845 or CONFIG_VIDEO_SED13806_16BPP 846 847- Keyboard Support: 848 CONFIG_KEYBOARD 849 850 Define this to enable a custom keyboard support. 851 This simply calls drv_keyboard_init() which must be 852 defined in your board-specific files. 853 The only board using this so far is RBC823. 854 855- LCD Support: CONFIG_LCD 856 857 Define this to enable LCD support (for output to LCD 858 display); also select one of the supported displays 859 by defining one of these: 860 861 CONFIG_NEC_NL6448AC33: 862 863 NEC NL6448AC33-18. Active, color, single scan. 864 865 CONFIG_NEC_NL6448BC20 866 867 NEC NL6448BC20-08. 6.5", 640x480. 868 Active, color, single scan. 869 870 CONFIG_NEC_NL6448BC33_54 871 872 NEC NL6448BC33-54. 10.4", 640x480. 873 Active, color, single scan. 874 875 CONFIG_SHARP_16x9 876 877 Sharp 320x240. Active, color, single scan. 878 It isn't 16x9, and I am not sure what it is. 879 880 CONFIG_SHARP_LQ64D341 881 882 Sharp LQ64D341 display, 640x480. 883 Active, color, single scan. 884 885 CONFIG_HLD1045 886 887 HLD1045 display, 640x480. 888 Active, color, single scan. 889 890 CONFIG_OPTREX_BW 891 892 Optrex CBL50840-2 NF-FW 99 22 M5 893 or 894 Hitachi LMG6912RPFC-00T 895 or 896 Hitachi SP14Q002 897 898 320x240. Black & white. 899 900 Normally display is black on white background; define 901 CFG_WHITE_ON_BLACK to get it inverted. 902 903- Splash Screen Support: CONFIG_SPLASH_SCREEN 904 905 If this option is set, the environment is checked for 906 a variable "splashimage". If found, the usual display 907 of logo, copyright and system information on the LCD 908 is supressed and the BMP image at the address 909 specified in "splashimage" is loaded instead. The 910 console is redirected to the "nulldev", too. This 911 allows for a "silent" boot where a splash screen is 912 loaded very quickly after power-on. 913 914- Compression support: 915 CONFIG_BZIP2 916 917 If this option is set, support for bzip2 compressed 918 images is included. If not, only uncompressed and gzip 919 compressed images are supported. 920 921 NOTE: the bzip2 algorithm requires a lot of RAM, so 922 the malloc area (as defined by CFG_MALLOC_LEN) should 923 be at least 4MB. 924 925- Ethernet address: 926 CONFIG_ETHADDR 927 CONFIG_ETH2ADDR 928 CONFIG_ETH3ADDR 929 930 Define a default value for ethernet address to use 931 for the respective ethernet interface, in case this 932 is not determined automatically. 933 934- IP address: 935 CONFIG_IPADDR 936 937 Define a default value for the IP address to use for 938 the default ethernet interface, in case this is not 939 determined through e.g. bootp. 940 941- Server IP address: 942 CONFIG_SERVERIP 943 944 Defines a default value for theIP address of a TFTP 945 server to contact when using the "tftboot" command. 946 947- BOOTP Recovery Mode: 948 CONFIG_BOOTP_RANDOM_DELAY 949 950 If you have many targets in a network that try to 951 boot using BOOTP, you may want to avoid that all 952 systems send out BOOTP requests at precisely the same 953 moment (which would happen for instance at recovery 954 from a power failure, when all systems will try to 955 boot, thus flooding the BOOTP server. Defining 956 CONFIG_BOOTP_RANDOM_DELAY causes a random delay to be 957 inserted before sending out BOOTP requests. The 958 following delays are insterted then: 959 960 1st BOOTP request: delay 0 ... 1 sec 961 2nd BOOTP request: delay 0 ... 2 sec 962 3rd BOOTP request: delay 0 ... 4 sec 963 4th and following 964 BOOTP requests: delay 0 ... 8 sec 965 966- DHCP Advanced Options: 967 CONFIG_BOOTP_MASK 968 969 You can fine tune the DHCP functionality by adding 970 these flags to the CONFIG_BOOTP_MASK define: 971 972 CONFIG_BOOTP_DNS2 - If a DHCP client requests the DNS 973 serverip from a DHCP server, it is possible that more 974 than one DNS serverip is offered to the client. 975 If CONFIG_BOOTP_DNS2 is enabled, the secondary DNS 976 serverip will be stored in the additional environment 977 variable "dnsip2". The first DNS serverip is always 978 stored in the variable "dnsip", when CONFIG_BOOTP_DNS 979 is added to the CONFIG_BOOTP_MASK. 980 981 CONFIG_BOOTP_SEND_HOSTNAME - Some DHCP servers are capable 982 to do a dynamic update of a DNS server. To do this, they 983 need the hostname of the DHCP requester. 984 If CONFIG_BOOP_SEND_HOSTNAME is added to the 985 CONFIG_BOOTP_MASK, the content of the "hostname" 986 environment variable is passed as option 12 to 987 the DHCP server. 988 989- Status LED: CONFIG_STATUS_LED 990 991 Several configurations allow to display the current 992 status using a LED. For instance, the LED will blink 993 fast while running U-Boot code, stop blinking as 994 soon as a reply to a BOOTP request was received, and 995 start blinking slow once the Linux kernel is running 996 (supported by a status LED driver in the Linux 997 kernel). Defining CONFIG_STATUS_LED enables this 998 feature in U-Boot. 999 1000- CAN Support: CONFIG_CAN_DRIVER 1001 1002 Defining CONFIG_CAN_DRIVER enables CAN driver support 1003 on those systems that support this (optional) 1004 feature, like the TQM8xxL modules. 1005 1006- I2C Support: CONFIG_HARD_I2C | CONFIG_SOFT_I2C 1007 1008 These enable I2C serial bus commands. Defining either of 1009 (but not both of) CONFIG_HARD_I2C or CONFIG_SOFT_I2C will 1010 include the appropriate I2C driver for the selected cpu. 1011 1012 This will allow you to use i2c commands at the u-boot 1013 command line (as long as you set CFG_CMD_I2C in 1014 CONFIG_COMMANDS) and communicate with i2c based realtime 1015 clock chips. See common/cmd_i2c.c for a description of the 1016 command line interface. 1017 1018 CONFIG_HARD_I2C selects the CPM hardware driver for I2C. 1019 1020 CONFIG_SOFT_I2C configures u-boot to use a software (aka 1021 bit-banging) driver instead of CPM or similar hardware 1022 support for I2C. 1023 1024 There are several other quantities that must also be 1025 defined when you define CONFIG_HARD_I2C or CONFIG_SOFT_I2C. 1026 1027 In both cases you will need to define CFG_I2C_SPEED 1028 to be the frequency (in Hz) at which you wish your i2c bus 1029 to run and CFG_I2C_SLAVE to be the address of this node (ie 1030 the cpu's i2c node address). 1031 1032 Now, the u-boot i2c code for the mpc8xx (cpu/mpc8xx/i2c.c) 1033 sets the cpu up as a master node and so its address should 1034 therefore be cleared to 0 (See, eg, MPC823e User's Manual 1035 p.16-473). So, set CFG_I2C_SLAVE to 0. 1036 1037 That's all that's required for CONFIG_HARD_I2C. 1038 1039 If you use the software i2c interface (CONFIG_SOFT_I2C) 1040 then the following macros need to be defined (examples are 1041 from include/configs/lwmon.h): 1042 1043 I2C_INIT 1044 1045 (Optional). Any commands necessary to enable the I2C 1046 controller or configure ports. 1047 1048 eg: #define I2C_INIT (immr->im_cpm.cp_pbdir |= PB_SCL) 1049 1050 I2C_PORT 1051 1052 (Only for MPC8260 CPU). The I/O port to use (the code 1053 assumes both bits are on the same port). Valid values 1054 are 0..3 for ports A..D. 1055 1056 I2C_ACTIVE 1057 1058 The code necessary to make the I2C data line active 1059 (driven). If the data line is open collector, this 1060 define can be null. 1061 1062 eg: #define I2C_ACTIVE (immr->im_cpm.cp_pbdir |= PB_SDA) 1063 1064 I2C_TRISTATE 1065 1066 The code necessary to make the I2C data line tri-stated 1067 (inactive). If the data line is open collector, this 1068 define can be null. 1069 1070 eg: #define I2C_TRISTATE (immr->im_cpm.cp_pbdir &= ~PB_SDA) 1071 1072 I2C_READ 1073 1074 Code that returns TRUE if the I2C data line is high, 1075 FALSE if it is low. 1076 1077 eg: #define I2C_READ ((immr->im_cpm.cp_pbdat & PB_SDA) != 0) 1078 1079 I2C_SDA(bit) 1080 1081 If <bit> is TRUE, sets the I2C data line high. If it 1082 is FALSE, it clears it (low). 1083 1084 eg: #define I2C_SDA(bit) \ 1085 if(bit) immr->im_cpm.cp_pbdat |= PB_SDA; \ 1086 else immr->im_cpm.cp_pbdat &= ~PB_SDA 1087 1088 I2C_SCL(bit) 1089 1090 If <bit> is TRUE, sets the I2C clock line high. If it 1091 is FALSE, it clears it (low). 1092 1093 eg: #define I2C_SCL(bit) \ 1094 if(bit) immr->im_cpm.cp_pbdat |= PB_SCL; \ 1095 else immr->im_cpm.cp_pbdat &= ~PB_SCL 1096 1097 I2C_DELAY 1098 1099 This delay is invoked four times per clock cycle so this 1100 controls the rate of data transfer. The data rate thus 1101 is 1 / (I2C_DELAY * 4). Often defined to be something 1102 like: 1103 1104 #define I2C_DELAY udelay(2) 1105 1106 CFG_I2C_INIT_BOARD 1107 1108 When a board is reset during an i2c bus transfer 1109 chips might think that the current transfer is still 1110 in progress. On some boards it is possible to access 1111 the i2c SCLK line directly, either by using the 1112 processor pin as a GPIO or by having a second pin 1113 connected to the bus. If this option is defined a 1114 custom i2c_init_board() routine in boards/xxx/board.c 1115 is run early in the boot sequence. 1116 1117- SPI Support: CONFIG_SPI 1118 1119 Enables SPI driver (so far only tested with 1120 SPI EEPROM, also an instance works with Crystal A/D and 1121 D/As on the SACSng board) 1122 1123 CONFIG_SPI_X 1124 1125 Enables extended (16-bit) SPI EEPROM addressing. 1126 (symmetrical to CONFIG_I2C_X) 1127 1128 CONFIG_SOFT_SPI 1129 1130 Enables a software (bit-bang) SPI driver rather than 1131 using hardware support. This is a general purpose 1132 driver that only requires three general I/O port pins 1133 (two outputs, one input) to function. If this is 1134 defined, the board configuration must define several 1135 SPI configuration items (port pins to use, etc). For 1136 an example, see include/configs/sacsng.h. 1137 1138- FPGA Support: CONFIG_FPGA_COUNT 1139 1140 Specify the number of FPGA devices to support. 1141 1142 CONFIG_FPGA 1143 1144 Used to specify the types of FPGA devices. For 1145 example, 1146 #define CONFIG_FPGA CFG_XILINX_VIRTEX2 1147 1148 CFG_FPGA_PROG_FEEDBACK 1149 1150 Enable printing of hash marks during FPGA 1151 configuration. 1152 1153 CFG_FPGA_CHECK_BUSY 1154 1155 Enable checks on FPGA configuration interface busy 1156 status by the configuration function. This option 1157 will require a board or device specific function to 1158 be written. 1159 1160 CONFIG_FPGA_DELAY 1161 1162 If defined, a function that provides delays in the 1163 FPGA configuration driver. 1164 1165 CFG_FPGA_CHECK_CTRLC 1166 1167 Allow Control-C to interrupt FPGA configuration 1168 1169 CFG_FPGA_CHECK_ERROR 1170 1171 Check for configuration errors during FPGA bitfile 1172 loading. For example, abort during Virtex II 1173 configuration if the INIT_B line goes low (which 1174 indicated a CRC error). 1175 1176 CFG_FPGA_WAIT_INIT 1177 1178 Maximum time to wait for the INIT_B line to deassert 1179 after PROB_B has been deasserted during a Virtex II 1180 FPGA configuration sequence. The default time is 500 mS. 1181 1182 CFG_FPGA_WAIT_BUSY 1183 1184 Maximum time to wait for BUSY to deassert during 1185 Virtex II FPGA configuration. The default is 5 mS. 1186 1187 CFG_FPGA_WAIT_CONFIG 1188 1189 Time to wait after FPGA configuration. The default is 1190 200 mS. 1191 1192- FPGA Support: CONFIG_FPGA_COUNT 1193 1194 Specify the number of FPGA devices to support. 1195 1196 CONFIG_FPGA 1197 1198 Used to specify the types of FPGA devices. For example, 1199 #define CONFIG_FPGA CFG_XILINX_VIRTEX2 1200 1201 CFG_FPGA_PROG_FEEDBACK 1202 1203 Enable printing of hash marks during FPGA configuration. 1204 1205 CFG_FPGA_CHECK_BUSY 1206 1207 Enable checks on FPGA configuration interface busy 1208 status by the configuration function. This option 1209 will require a board or device specific function to 1210 be written. 1211 1212 CONFIG_FPGA_DELAY 1213 1214 If defined, a function that provides delays in the FPGA 1215 configuration driver. 1216 1217 CFG_FPGA_CHECK_CTRLC 1218 Allow Control-C to interrupt FPGA configuration 1219 1220 CFG_FPGA_CHECK_ERROR 1221 1222 Check for configuration errors during FPGA bitfile 1223 loading. For example, abort during Virtex II 1224 configuration if the INIT_B line goes low (which 1225 indicated a CRC error). 1226 1227 CFG_FPGA_WAIT_INIT 1228 1229 Maximum time to wait for the INIT_B line to deassert 1230 after PROB_B has been deasserted during a Virtex II 1231 FPGA configuration sequence. The default time is 500 1232 mS. 1233 1234 CFG_FPGA_WAIT_BUSY 1235 1236 Maximum time to wait for BUSY to deassert during 1237 Virtex II FPGA configuration. The default is 5 mS. 1238 1239 CFG_FPGA_WAIT_CONFIG 1240 1241 Time to wait after FPGA configuration. The default is 1242 200 mS. 1243 1244- Configuration Management: 1245 CONFIG_IDENT_STRING 1246 1247 If defined, this string will be added to the U-Boot 1248 version information (U_BOOT_VERSION) 1249 1250- Vendor Parameter Protection: 1251 1252 U-Boot considers the values of the environment 1253 variables "serial#" (Board Serial Number) and 1254 "ethaddr" (Ethernet Address) to be parameters that 1255 are set once by the board vendor / manufacturer, and 1256 protects these variables from casual modification by 1257 the user. Once set, these variables are read-only, 1258 and write or delete attempts are rejected. You can 1259 change this behviour: 1260 1261 If CONFIG_ENV_OVERWRITE is #defined in your config 1262 file, the write protection for vendor parameters is 1263 completely disabled. Anybody can change or delete 1264 these parameters. 1265 1266 Alternatively, if you #define _both_ CONFIG_ETHADDR 1267 _and_ CONFIG_OVERWRITE_ETHADDR_ONCE, a default 1268 ethernet address is installed in the environment, 1269 which can be changed exactly ONCE by the user. [The 1270 serial# is unaffected by this, i. e. it remains 1271 read-only.] 1272 1273- Protected RAM: 1274 CONFIG_PRAM 1275 1276 Define this variable to enable the reservation of 1277 "protected RAM", i. e. RAM which is not overwritten 1278 by U-Boot. Define CONFIG_PRAM to hold the number of 1279 kB you want to reserve for pRAM. You can overwrite 1280 this default value by defining an environment 1281 variable "pram" to the number of kB you want to 1282 reserve. Note that the board info structure will 1283 still show the full amount of RAM. If pRAM is 1284 reserved, a new environment variable "mem" will 1285 automatically be defined to hold the amount of 1286 remaining RAM in a form that can be passed as boot 1287 argument to Linux, for instance like that: 1288 1289 setenv bootargs ... mem=\$(mem) 1290 saveenv 1291 1292 This way you can tell Linux not to use this memory, 1293 either, which results in a memory region that will 1294 not be affected by reboots. 1295 1296 *WARNING* If your board configuration uses automatic 1297 detection of the RAM size, you must make sure that 1298 this memory test is non-destructive. So far, the 1299 following board configurations are known to be 1300 "pRAM-clean": 1301 1302 ETX094, IVMS8, IVML24, SPD8xx, TQM8xxL, 1303 HERMES, IP860, RPXlite, LWMON, LANTEC, 1304 PCU_E, FLAGADM, TQM8260 1305 1306- Error Recovery: 1307 CONFIG_PANIC_HANG 1308 1309 Define this variable to stop the system in case of a 1310 fatal error, so that you have to reset it manually. 1311 This is probably NOT a good idea for an embedded 1312 system where you want to system to reboot 1313 automatically as fast as possible, but it may be 1314 useful during development since you can try to debug 1315 the conditions that lead to the situation. 1316 1317 CONFIG_NET_RETRY_COUNT 1318 1319 This variable defines the number of retries for 1320 network operations like ARP, RARP, TFTP, or BOOTP 1321 before giving up the operation. If not defined, a 1322 default value of 5 is used. 1323 1324- Command Interpreter: 1325 CFG_HUSH_PARSER 1326 1327 Define this variable to enable the "hush" shell (from 1328 Busybox) as command line interpreter, thus enabling 1329 powerful command line syntax like 1330 if...then...else...fi conditionals or `&&' and '||' 1331 constructs ("shell scripts"). 1332 1333 If undefined, you get the old, much simpler behaviour 1334 with a somewhat smaller memory footprint. 1335 1336 1337 CFG_PROMPT_HUSH_PS2 1338 1339 This defines the secondary prompt string, which is 1340 printed when the command interpreter needs more input 1341 to complete a command. Usually "> ". 1342 1343 Note: 1344 1345 In the current implementation, the local variables 1346 space and global environment variables space are 1347 separated. Local variables are those you define by 1348 simply typing `name=value'. To access a local 1349 variable later on, you have write `$name' or 1350 `${name}'; to execute the contents of a variable 1351 directly type `$name' at the command prompt. 1352 1353 Global environment variables are those you use 1354 setenv/printenv to work with. To run a command stored 1355 in such a variable, you need to use the run command, 1356 and you must not use the '$' sign to access them. 1357 1358 To store commands and special characters in a 1359 variable, please use double quotation marks 1360 surrounding the whole text of the variable, instead 1361 of the backslashes before semicolons and special 1362 symbols. 1363 1364- Default Environment: 1365 CONFIG_EXTRA_ENV_SETTINGS 1366 1367 Define this to contain any number of null terminated 1368 strings (variable = value pairs) that will be part of 1369 the default environment compiled into the boot image. 1370 1371 For example, place something like this in your 1372 board's config file: 1373 1374 #define CONFIG_EXTRA_ENV_SETTINGS \ 1375 "myvar1=value1\0" \ 1376 "myvar2=value2\0" 1377 1378 Warning: This method is based on knowledge about the 1379 internal format how the environment is stored by the 1380 U-Boot code. This is NOT an official, exported 1381 interface! Although it is unlikely that this format 1382 will change soon, there is no guarantee either. 1383 You better know what you are doing here. 1384 1385 Note: overly (ab)use of the default environment is 1386 discouraged. Make sure to check other ways to preset 1387 the environment like the autoscript function or the 1388 boot command first. 1389 1390- DataFlash Support: 1391 CONFIG_HAS_DATAFLASH 1392 1393 Defining this option enables DataFlash features and 1394 allows to read/write in Dataflash via the standard 1395 commands cp, md... 1396 1397- Show boot progress: 1398 CONFIG_SHOW_BOOT_PROGRESS 1399 1400 Defining this option allows to add some board- 1401 specific code (calling a user-provided function 1402 "show_boot_progress(int)") that enables you to show 1403 the system's boot progress on some display (for 1404 example, some LED's) on your board. At the moment, 1405 the following checkpoints are implemented: 1406 1407 Arg Where When 1408 1 common/cmd_bootm.c before attempting to boot an image 1409 -1 common/cmd_bootm.c Image header has bad magic number 1410 2 common/cmd_bootm.c Image header has correct magic number 1411 -2 common/cmd_bootm.c Image header has bad checksum 1412 3 common/cmd_bootm.c Image header has correct checksum 1413 -3 common/cmd_bootm.c Image data has bad checksum 1414 4 common/cmd_bootm.c Image data has correct checksum 1415 -4 common/cmd_bootm.c Image is for unsupported architecture 1416 5 common/cmd_bootm.c Architecture check OK 1417 -5 common/cmd_bootm.c Wrong Image Type (not kernel, multi, standalone) 1418 6 common/cmd_bootm.c Image Type check OK 1419 -6 common/cmd_bootm.c gunzip uncompression error 1420 -7 common/cmd_bootm.c Unimplemented compression type 1421 7 common/cmd_bootm.c Uncompression OK 1422 -8 common/cmd_bootm.c Wrong Image Type (not kernel, multi, standalone) 1423 8 common/cmd_bootm.c Image Type check OK 1424 -9 common/cmd_bootm.c Unsupported OS (not Linux, BSD, VxWorks, QNX) 1425 9 common/cmd_bootm.c Start initial ramdisk verification 1426 -10 common/cmd_bootm.c Ramdisk header has bad magic number 1427 -11 common/cmd_bootm.c Ramdisk header has bad checksum 1428 10 common/cmd_bootm.c Ramdisk header is OK 1429 -12 common/cmd_bootm.c Ramdisk data has bad checksum 1430 11 common/cmd_bootm.c Ramdisk data has correct checksum 1431 12 common/cmd_bootm.c Ramdisk verification complete, start loading 1432 -13 common/cmd_bootm.c Wrong Image Type (not PPC Linux Ramdisk) 1433 13 common/cmd_bootm.c Start multifile image verification 1434 14 common/cmd_bootm.c No initial ramdisk, no multifile, continue. 1435 15 common/cmd_bootm.c All preparation done, transferring control to OS 1436 1437 -1 common/cmd_doc.c Bad usage of "doc" command 1438 -1 common/cmd_doc.c No boot device 1439 -1 common/cmd_doc.c Unknown Chip ID on boot device 1440 -1 common/cmd_doc.c Read Error on boot device 1441 -1 common/cmd_doc.c Image header has bad magic number 1442 1443 -1 common/cmd_ide.c Bad usage of "ide" command 1444 -1 common/cmd_ide.c No boot device 1445 -1 common/cmd_ide.c Unknown boot device 1446 -1 common/cmd_ide.c Unknown partition table 1447 -1 common/cmd_ide.c Invalid partition type 1448 -1 common/cmd_ide.c Read Error on boot device 1449 -1 common/cmd_ide.c Image header has bad magic number 1450 1451 -1 common/cmd_nand.c Bad usage of "nand" command 1452 -1 common/cmd_nand.c No boot device 1453 -1 common/cmd_nand.c Unknown Chip ID on boot device 1454 -1 common/cmd_nand.c Read Error on boot device 1455 -1 common/cmd_nand.c Image header has bad magic number 1456 1457 -1 common/env_common.c Environment has a bad CRC, using default 1458 1459 1460Modem Support: 1461-------------- 1462 1463[so far only for SMDK2400 and TRAB boards] 1464 1465- Modem support endable: 1466 CONFIG_MODEM_SUPPORT 1467 1468- RTS/CTS Flow control enable: 1469 CONFIG_HWFLOW 1470 1471- Modem debug support: 1472 CONFIG_MODEM_SUPPORT_DEBUG 1473 1474 Enables debugging stuff (char screen[1024], dbg()) 1475 for modem support. Useful only with BDI2000. 1476 1477- Interrupt support (PPC): 1478 1479 There are common interrupt_init() and timer_interrupt() 1480 for all PPC archs. interrupt_init() calls interrupt_init_cpu() 1481 for cpu specific initialization. interrupt_init_cpu() 1482 should set decrementer_count to appropriate value. If 1483 cpu resets decrementer automatically after interrupt 1484 (ppc4xx) it should set decrementer_count to zero. 1485 timer_interrupt() calls timer_interrupt_cpu() for cpu 1486 specific handling. If board has watchdog / status_led 1487 / other_activity_monitor it works automatically from 1488 general timer_interrupt(). 1489 1490- General: 1491 1492 In the target system modem support is enabled when a 1493 specific key (key combination) is pressed during 1494 power-on. Otherwise U-Boot will boot normally 1495 (autoboot). The key_pressed() fuction is called from 1496 board_init(). Currently key_pressed() is a dummy 1497 function, returning 1 and thus enabling modem 1498 initialization. 1499 1500 If there are no modem init strings in the 1501 environment, U-Boot proceed to autoboot; the 1502 previous output (banner, info printfs) will be 1503 supressed, though. 1504 1505 See also: doc/README.Modem 1506 1507 1508Configuration Settings: 1509----------------------- 1510 1511- CFG_LONGHELP: Defined when you want long help messages included; 1512 undefine this when you're short of memory. 1513 1514- CFG_PROMPT: This is what U-Boot prints on the console to 1515 prompt for user input. 1516 1517- CFG_CBSIZE: Buffer size for input from the Console 1518 1519- CFG_PBSIZE: Buffer size for Console output 1520 1521- CFG_MAXARGS: max. Number of arguments accepted for monitor commands 1522 1523- CFG_BARGSIZE: Buffer size for Boot Arguments which are passed to 1524 the application (usually a Linux kernel) when it is 1525 booted 1526 1527- CFG_BAUDRATE_TABLE: 1528 List of legal baudrate settings for this board. 1529 1530- CFG_CONSOLE_INFO_QUIET 1531 Suppress display of console information at boot. 1532 1533- CFG_CONSOLE_IS_IN_ENV 1534 If the board specific function 1535 extern int overwrite_console (void); 1536 returns 1, the stdin, stderr and stdout are switched to the 1537 serial port, else the settings in the environment are used. 1538 1539- CFG_CONSOLE_OVERWRITE_ROUTINE 1540 Enable the call to overwrite_console(). 1541 1542- CFG_CONSOLE_ENV_OVERWRITE 1543 Enable overwrite of previous console environment settings. 1544 1545- CFG_MEMTEST_START, CFG_MEMTEST_END: 1546 Begin and End addresses of the area used by the 1547 simple memory test. 1548 1549- CFG_ALT_MEMTEST: 1550 Enable an alternate, more extensive memory test. 1551 1552- CFG_MEMTEST_SCRATCH: 1553 Scratch address used by the alternate memory test 1554 You only need to set this if address zero isn't writeable 1555 1556- CFG_TFTP_LOADADDR: 1557 Default load address for network file downloads 1558 1559- CFG_LOADS_BAUD_CHANGE: 1560 Enable temporary baudrate change while serial download 1561 1562- CFG_SDRAM_BASE: 1563 Physical start address of SDRAM. _Must_ be 0 here. 1564 1565- CFG_MBIO_BASE: 1566 Physical start address of Motherboard I/O (if using a 1567 Cogent motherboard) 1568 1569- CFG_FLASH_BASE: 1570 Physical start address of Flash memory. 1571 1572- CFG_MONITOR_BASE: 1573 Physical start address of boot monitor code (set by 1574 make config files to be same as the text base address 1575 (TEXT_BASE) used when linking) - same as 1576 CFG_FLASH_BASE when booting from flash. 1577 1578- CFG_MONITOR_LEN: 1579 Size of memory reserved for monitor code, used to 1580 determine _at_compile_time_ (!) if the environment is 1581 embedded within the U-Boot image, or in a separate 1582 flash sector. 1583 1584- CFG_MALLOC_LEN: 1585 Size of DRAM reserved for malloc() use. 1586 1587- CFG_BOOTMAPSZ: 1588 Maximum size of memory mapped by the startup code of 1589 the Linux kernel; all data that must be processed by 1590 the Linux kernel (bd_info, boot arguments, eventually 1591 initrd image) must be put below this limit. 1592 1593- CFG_MAX_FLASH_BANKS: 1594 Max number of Flash memory banks 1595 1596- CFG_MAX_FLASH_SECT: 1597 Max number of sectors on a Flash chip 1598 1599- CFG_FLASH_ERASE_TOUT: 1600 Timeout for Flash erase operations (in ms) 1601 1602- CFG_FLASH_WRITE_TOUT: 1603 Timeout for Flash write operations (in ms) 1604 1605- CFG_FLASH_LOCK_TOUT 1606 Timeout for Flash set sector lock bit operation (in ms) 1607 1608- CFG_FLASH_UNLOCK_TOUT 1609 Timeout for Flash clear lock bits operation (in ms) 1610 1611- CFG_FLASH_PROTECTION 1612 If defined, hardware flash sectors protection is used 1613 instead of U-Boot software protection. 1614 1615- CFG_DIRECT_FLASH_TFTP: 1616 1617 Enable TFTP transfers directly to flash memory; 1618 without this option such a download has to be 1619 performed in two steps: (1) download to RAM, and (2) 1620 copy from RAM to flash. 1621 1622 The two-step approach is usually more reliable, since 1623 you can check if the download worked before you erase 1624 the flash, but in some situations (when sytem RAM is 1625 too limited to allow for a tempory copy of the 1626 downloaded image) this option may be very useful. 1627 1628- CFG_FLASH_CFI: 1629 Define if the flash driver uses extra elements in the 1630 common flash structure for storing flash geometry 1631 1632- CFG_RX_ETH_BUFFER: 1633 Defines the number of ethernet receive buffers. On some 1634 ethernet controllers it is recommended to set this value 1635 to 8 or even higher (EEPRO100 or 405 EMAC), since all 1636 buffers can be full shortly after enabling the interface 1637 on high ethernet traffic. 1638 Defaults to 4 if not defined. 1639 1640The following definitions that deal with the placement and management 1641of environment data (variable area); in general, we support the 1642following configurations: 1643 1644- CFG_ENV_IS_IN_FLASH: 1645 1646 Define this if the environment is in flash memory. 1647 1648 a) The environment occupies one whole flash sector, which is 1649 "embedded" in the text segment with the U-Boot code. This 1650 happens usually with "bottom boot sector" or "top boot 1651 sector" type flash chips, which have several smaller 1652 sectors at the start or the end. For instance, such a 1653 layout can have sector sizes of 8, 2x4, 16, Nx32 kB. In 1654 such a case you would place the environment in one of the 1655 4 kB sectors - with U-Boot code before and after it. With 1656 "top boot sector" type flash chips, you would put the 1657 environment in one of the last sectors, leaving a gap 1658 between U-Boot and the environment. 1659 1660 - CFG_ENV_OFFSET: 1661 1662 Offset of environment data (variable area) to the 1663 beginning of flash memory; for instance, with bottom boot 1664 type flash chips the second sector can be used: the offset 1665 for this sector is given here. 1666 1667 CFG_ENV_OFFSET is used relative to CFG_FLASH_BASE. 1668 1669 - CFG_ENV_ADDR: 1670 1671 This is just another way to specify the start address of 1672 the flash sector containing the environment (instead of 1673 CFG_ENV_OFFSET). 1674 1675 - CFG_ENV_SECT_SIZE: 1676 1677 Size of the sector containing the environment. 1678 1679 1680 b) Sometimes flash chips have few, equal sized, BIG sectors. 1681 In such a case you don't want to spend a whole sector for 1682 the environment. 1683 1684 - CFG_ENV_SIZE: 1685 1686 If you use this in combination with CFG_ENV_IS_IN_FLASH 1687 and CFG_ENV_SECT_SIZE, you can specify to use only a part 1688 of this flash sector for the environment. This saves 1689 memory for the RAM copy of the environment. 1690 1691 It may also save flash memory if you decide to use this 1692 when your environment is "embedded" within U-Boot code, 1693 since then the remainder of the flash sector could be used 1694 for U-Boot code. It should be pointed out that this is 1695 STRONGLY DISCOURAGED from a robustness point of view: 1696 updating the environment in flash makes it always 1697 necessary to erase the WHOLE sector. If something goes 1698 wrong before the contents has been restored from a copy in 1699 RAM, your target system will be dead. 1700 1701 - CFG_ENV_ADDR_REDUND 1702 CFG_ENV_SIZE_REDUND 1703 1704 These settings describe a second storage area used to hold 1705 a redundand copy of the environment data, so that there is 1706 a valid backup copy in case there is a power failure during 1707 a "saveenv" operation. 1708 1709BE CAREFUL! Any changes to the flash layout, and some changes to the 1710source code will make it necessary to adapt <board>/u-boot.lds* 1711accordingly! 1712 1713 1714- CFG_ENV_IS_IN_NVRAM: 1715 1716 Define this if you have some non-volatile memory device 1717 (NVRAM, battery buffered SRAM) which you want to use for the 1718 environment. 1719 1720 - CFG_ENV_ADDR: 1721 - CFG_ENV_SIZE: 1722 1723 These two #defines are used to determin the memory area you 1724 want to use for environment. It is assumed that this memory 1725 can just be read and written to, without any special 1726 provision. 1727 1728BE CAREFUL! The first access to the environment happens quite early 1729in U-Boot initalization (when we try to get the setting of for the 1730console baudrate). You *MUST* have mappend your NVRAM area then, or 1731U-Boot will hang. 1732 1733Please note that even with NVRAM we still use a copy of the 1734environment in RAM: we could work on NVRAM directly, but we want to 1735keep settings there always unmodified except somebody uses "saveenv" 1736to save the current settings. 1737 1738 1739- CFG_ENV_IS_IN_EEPROM: 1740 1741 Use this if you have an EEPROM or similar serial access 1742 device and a driver for it. 1743 1744 - CFG_ENV_OFFSET: 1745 - CFG_ENV_SIZE: 1746 1747 These two #defines specify the offset and size of the 1748 environment area within the total memory of your EEPROM. 1749 1750 - CFG_I2C_EEPROM_ADDR: 1751 If defined, specified the chip address of the EEPROM device. 1752 The default address is zero. 1753 1754 - CFG_EEPROM_PAGE_WRITE_BITS: 1755 If defined, the number of bits used to address bytes in a 1756 single page in the EEPROM device. A 64 byte page, for example 1757 would require six bits. 1758 1759 - CFG_EEPROM_PAGE_WRITE_DELAY_MS: 1760 If defined, the number of milliseconds to delay between 1761 page writes. The default is zero milliseconds. 1762 1763 - CFG_I2C_EEPROM_ADDR_LEN: 1764 The length in bytes of the EEPROM memory array address. Note 1765 that this is NOT the chip address length! 1766 1767 - CFG_EEPROM_SIZE: 1768 The size in bytes of the EEPROM device. 1769 1770 1771- CFG_ENV_IS_IN_DATAFLASH: 1772 1773 Define this if you have a DataFlash memory device which you 1774 want to use for the environment. 1775 1776 - CFG_ENV_OFFSET: 1777 - CFG_ENV_ADDR: 1778 - CFG_ENV_SIZE: 1779 1780 These three #defines specify the offset and size of the 1781 environment area within the total memory of your DataFlash placed 1782 at the specified address. 1783 1784 1785- CFG_SPI_INIT_OFFSET 1786 1787 Defines offset to the initial SPI buffer area in DPRAM. The 1788 area is used at an early stage (ROM part) if the environment 1789 is configured to reside in the SPI EEPROM: We need a 520 byte 1790 scratch DPRAM area. It is used between the two initialization 1791 calls (spi_init_f() and spi_init_r()). A value of 0xB00 seems 1792 to be a good choice since it makes it far enough from the 1793 start of the data area as well as from the stack pointer. 1794 1795Please note that the environment is read-only as long as the monitor 1796has been relocated to RAM and a RAM copy of the environment has been 1797created; also, when using EEPROM you will have to use getenv_r() 1798until then to read environment variables. 1799 1800The environment is protected by a CRC32 checksum. Before the monitor 1801is relocated into RAM, as a result of a bad CRC you will be working 1802with the compiled-in default environment - *silently*!!! [This is 1803necessary, because the first environment variable we need is the 1804"baudrate" setting for the console - if we have a bad CRC, we don't 1805have any device yet where we could complain.] 1806 1807Note: once the monitor has been relocated, then it will complain if 1808the default environment is used; a new CRC is computed as soon as you 1809use the "saveenv" command to store a valid environment. 1810 1811- CFG_FAULT_ECHO_LINK_DOWN: 1812 Echo the inverted Ethernet link state to the fault LED. 1813 1814 Note: If this option is active, then CFG_FAULT_MII_ADDR 1815 also needs to be defined. 1816 1817- CFG_FAULT_MII_ADDR: 1818 MII address of the PHY to check for the Ethernet link state. 1819 1820Low Level (hardware related) configuration options: 1821--------------------------------------------------- 1822 1823- CFG_CACHELINE_SIZE: 1824 Cache Line Size of the CPU. 1825 1826- CFG_DEFAULT_IMMR: 1827 Default address of the IMMR after system reset. 1828 1829 Needed on some 8260 systems (MPC8260ADS, PQ2FADS-ZU, 1830 and RPXsuper) to be able to adjust the position of 1831 the IMMR register after a reset. 1832 1833- Floppy Disk Support: 1834 CFG_FDC_DRIVE_NUMBER 1835 1836 the default drive number (default value 0) 1837 1838 CFG_ISA_IO_STRIDE 1839 1840 defines the spacing between fdc chipset registers 1841 (default value 1) 1842 1843 CFG_ISA_IO_OFFSET 1844 1845 defines the offset of register from address. It 1846 depends on which part of the data bus is connected to 1847 the fdc chipset. (default value 0) 1848 1849 If CFG_ISA_IO_STRIDE CFG_ISA_IO_OFFSET and 1850 CFG_FDC_DRIVE_NUMBER are undefined, they take their 1851 default value. 1852 1853 if CFG_FDC_HW_INIT is defined, then the function 1854 fdc_hw_init() is called at the beginning of the FDC 1855 setup. fdc_hw_init() must be provided by the board 1856 source code. It is used to make hardware dependant 1857 initializations. 1858 1859- CFG_IMMR: Physical address of the Internal Memory Mapped 1860 Register; DO NOT CHANGE! (11-4) 1861 [MPC8xx systems only] 1862 1863- CFG_INIT_RAM_ADDR: 1864 1865 Start address of memory area that can be used for 1866 initial data and stack; please note that this must be 1867 writable memory that is working WITHOUT special 1868 initialization, i. e. you CANNOT use normal RAM which 1869 will become available only after programming the 1870 memory controller and running certain initialization 1871 sequences. 1872 1873 U-Boot uses the following memory types: 1874 - MPC8xx and MPC8260: IMMR (internal memory of the CPU) 1875 - MPC824X: data cache 1876 - PPC4xx: data cache 1877 1878- CFG_GBL_DATA_OFFSET: 1879 1880 Offset of the initial data structure in the memory 1881 area defined by CFG_INIT_RAM_ADDR. Usually 1882 CFG_GBL_DATA_OFFSET is chosen such that the initial 1883 data is located at the end of the available space 1884 (sometimes written as (CFG_INIT_RAM_END - 1885 CFG_INIT_DATA_SIZE), and the initial stack is just 1886 below that area (growing from (CFG_INIT_RAM_ADDR + 1887 CFG_GBL_DATA_OFFSET) downward. 1888 1889 Note: 1890 On the MPC824X (or other systems that use the data 1891 cache for initial memory) the address chosen for 1892 CFG_INIT_RAM_ADDR is basically arbitrary - it must 1893 point to an otherwise UNUSED address space between 1894 the top of RAM and the start of the PCI space. 1895 1896- CFG_SIUMCR: SIU Module Configuration (11-6) 1897 1898- CFG_SYPCR: System Protection Control (11-9) 1899 1900- CFG_TBSCR: Time Base Status and Control (11-26) 1901 1902- CFG_PISCR: Periodic Interrupt Status and Control (11-31) 1903 1904- CFG_PLPRCR: PLL, Low-Power, and Reset Control Register (15-30) 1905 1906- CFG_SCCR: System Clock and reset Control Register (15-27) 1907 1908- CFG_OR_TIMING_SDRAM: 1909 SDRAM timing 1910 1911- CFG_MAMR_PTA: 1912 periodic timer for refresh 1913 1914- CFG_DER: Debug Event Register (37-47) 1915 1916- FLASH_BASE0_PRELIM, FLASH_BASE1_PRELIM, CFG_REMAP_OR_AM, 1917 CFG_PRELIM_OR_AM, CFG_OR_TIMING_FLASH, CFG_OR0_REMAP, 1918 CFG_OR0_PRELIM, CFG_BR0_PRELIM, CFG_OR1_REMAP, CFG_OR1_PRELIM, 1919 CFG_BR1_PRELIM: 1920 Memory Controller Definitions: BR0/1 and OR0/1 (FLASH) 1921 1922- SDRAM_BASE2_PRELIM, SDRAM_BASE3_PRELIM, SDRAM_MAX_SIZE, 1923 CFG_OR_TIMING_SDRAM, CFG_OR2_PRELIM, CFG_BR2_PRELIM, 1924 CFG_OR3_PRELIM, CFG_BR3_PRELIM: 1925 Memory Controller Definitions: BR2/3 and OR2/3 (SDRAM) 1926 1927- CFG_MAMR_PTA, CFG_MPTPR_2BK_4K, CFG_MPTPR_1BK_4K, CFG_MPTPR_2BK_8K, 1928 CFG_MPTPR_1BK_8K, CFG_MAMR_8COL, CFG_MAMR_9COL: 1929 Machine Mode Register and Memory Periodic Timer 1930 Prescaler definitions (SDRAM timing) 1931 1932- CFG_I2C_UCODE_PATCH, CFG_I2C_DPMEM_OFFSET [0x1FC0]: 1933 enable I2C microcode relocation patch (MPC8xx); 1934 define relocation offset in DPRAM [DSP2] 1935 1936- CFG_SPI_UCODE_PATCH, CFG_SPI_DPMEM_OFFSET [0x1FC0]: 1937 enable SPI microcode relocation patch (MPC8xx); 1938 define relocation offset in DPRAM [SCC4] 1939 1940- CFG_USE_OSCCLK: 1941 Use OSCM clock mode on MBX8xx board. Be careful, 1942 wrong setting might damage your board. Read 1943 doc/README.MBX before setting this variable! 1944 1945- CFG_CPM_POST_WORD_ADDR: (MPC8xx, MPC8260 only) 1946 Offset of the bootmode word in DPRAM used by post 1947 (Power On Self Tests). This definition overrides 1948 #define'd default value in commproc.h resp. 1949 cpm_8260.h. 1950 1951- CFG_PCI_SLV_MEM_LOCAL, CFG_PCI_SLV_MEM_BUS, CFG_PICMR0_MASK_ATTRIB, 1952 CFG_PCI_MSTR0_LOCAL, CFG_PCIMSK0_MASK, CFG_PCI_MSTR1_LOCAL, 1953 CFG_PCIMSK1_MASK, CFG_PCI_MSTR_MEM_LOCAL, CFG_PCI_MSTR_MEM_BUS, 1954 CFG_CPU_PCI_MEM_START, CFG_PCI_MSTR_MEM_SIZE, CFG_POCMR0_MASK_ATTRIB, 1955 CFG_PCI_MSTR_MEMIO_LOCAL, CFG_PCI_MSTR_MEMIO_BUS, CPU_PCI_MEMIO_START, 1956 CFG_PCI_MSTR_MEMIO_SIZE, CFG_POCMR1_MASK_ATTRIB, CFG_PCI_MSTR_IO_LOCAL, 1957 CFG_PCI_MSTR_IO_BUS, CFG_CPU_PCI_IO_START, CFG_PCI_MSTR_IO_SIZE, 1958 CFG_POCMR2_MASK_ATTRIB: (MPC826x only) 1959 Overrides the default PCI memory map in cpu/mpc8260/pci.c if set. 1960 1961Building the Software: 1962====================== 1963 1964Building U-Boot has been tested in native PPC environments (on a 1965PowerBook G3 running LinuxPPC 2000) and in cross environments 1966(running RedHat 6.x and 7.x Linux on x86, Solaris 2.6 on a SPARC, and 1967NetBSD 1.5 on x86). 1968 1969If you are not using a native PPC environment, it is assumed that you 1970have the GNU cross compiling tools available in your path and named 1971with a prefix of "powerpc-linux-". If this is not the case, (e.g. if 1972you are using Monta Vista's Hard Hat Linux CDK 1.2) you must change 1973the definition of CROSS_COMPILE in Makefile. For HHL on a 4xx CPU, 1974change it to: 1975 1976 CROSS_COMPILE = ppc_4xx- 1977 1978 1979U-Boot is intended to be simple to build. After installing the 1980sources you must configure U-Boot for one specific board type. This 1981is done by typing: 1982 1983 make NAME_config 1984 1985where "NAME_config" is the name of one of the existing 1986configurations; the following names are supported: 1987 1988 ADCIOP_config GTH_config TQM850L_config 1989 ADS860_config IP860_config TQM855L_config 1990 AR405_config IVML24_config TQM860L_config 1991 CANBT_config IVMS8_config WALNUT405_config 1992 CPCI405_config LANTEC_config cogent_common_config 1993 CPCIISER4_config MBX_config cogent_mpc8260_config 1994 CU824_config MBX860T_config cogent_mpc8xx_config 1995 ESTEEM192E_config RPXlite_config hermes_config 1996 ETX094_config RPXsuper_config hymod_config 1997 FADS823_config SM850_config lwmon_config 1998 FADS850SAR_config SPD823TS_config pcu_e_config 1999 FADS860T_config SXNI855T_config rsdproto_config 2000 FPS850L_config Sandpoint8240_config sbc8260_config 2001 GENIETV_config TQM823L_config PIP405_config 2002 GEN860T_config EBONY_config FPS860L_config 2003 ELPT860_config cmi_mpc5xx_config NETVIA_config 2004 at91rm9200dk_config omap1510inn_config MPC8260ADS_config 2005 omap1610inn_config ZPC1900_config MPC8540ADS_config 2006 MPC8560ADS_config QS850_config QS823_config 2007 QS860T_config 2008 2009Note: for some board special configuration names may exist; check if 2010 additional information is available from the board vendor; for 2011 instance, the TQM8xxL systems run normally at 50 MHz and use a 2012 SCC for 10baseT ethernet; there are also systems with 80 MHz 2013 CPU clock, and an optional Fast Ethernet module is available 2014 for CPU's with FEC. You can select such additional "features" 2015 when chosing the configuration, i. e. 2016 2017 make TQM860L_config 2018 - will configure for a plain TQM860L, i. e. 50MHz, no FEC 2019 2020 make TQM860L_FEC_config 2021 - will configure for a TQM860L at 50MHz with FEC for ethernet 2022 2023 make TQM860L_80MHz_config 2024 - will configure for a TQM860L at 80 MHz, with normal 10baseT 2025 interface 2026 2027 make TQM860L_FEC_80MHz_config 2028 - will configure for a TQM860L at 80 MHz with FEC for ethernet 2029 2030 make TQM823L_LCD_config 2031 - will configure for a TQM823L with U-Boot console on LCD 2032 2033 make TQM823L_LCD_80MHz_config 2034 - will configure for a TQM823L at 80 MHz with U-Boot console on LCD 2035 2036 etc. 2037 2038 2039Finally, type "make all", and you should get some working U-Boot 2040images ready for download to / installation on your system: 2041 2042- "u-boot.bin" is a raw binary image 2043- "u-boot" is an image in ELF binary format 2044- "u-boot.srec" is in Motorola S-Record format 2045 2046 2047Please be aware that the Makefiles assume you are using GNU make, so 2048for instance on NetBSD you might need to use "gmake" instead of 2049native "make". 2050 2051 2052If the system board that you have is not listed, then you will need 2053to port U-Boot to your hardware platform. To do this, follow these 2054steps: 2055 20561. Add a new configuration option for your board to the toplevel 2057 "Makefile" and to the "MAKEALL" script, using the existing 2058 entries as examples. Note that here and at many other places 2059 boards and other names are listed in alphabetical sort order. Please 2060 keep this order. 20612. Create a new directory to hold your board specific code. Add any 2062 files you need. In your board directory, you will need at least 2063 the "Makefile", a "<board>.c", "flash.c" and "u-boot.lds". 20643. Create a new configuration file "include/configs/<board>.h" for 2065 your board 20663. If you're porting U-Boot to a new CPU, then also create a new 2067 directory to hold your CPU specific code. Add any files you need. 20684. Run "make <board>_config" with your new name. 20695. Type "make", and you should get a working "u-boot.srec" file 2070 to be installed on your target system. 20716. Debug and solve any problems that might arise. 2072 [Of course, this last step is much harder than it sounds.] 2073 2074 2075Testing of U-Boot Modifications, Ports to New Hardware, etc.: 2076============================================================== 2077 2078If you have modified U-Boot sources (for instance added a new board 2079or support for new devices, a new CPU, etc.) you are expected to 2080provide feedback to the other developers. The feedback normally takes 2081the form of a "patch", i. e. a context diff against a certain (latest 2082official or latest in CVS) version of U-Boot sources. 2083 2084But before you submit such a patch, please verify that your modifi- 2085cation did not break existing code. At least make sure that *ALL* of 2086the supported boards compile WITHOUT ANY compiler warnings. To do so, 2087just run the "MAKEALL" script, which will configure and build U-Boot 2088for ALL supported system. Be warned, this will take a while. You can 2089select which (cross) compiler to use by passing a `CROSS_COMPILE' 2090environment variable to the script, i. e. to use the cross tools from 2091MontaVista's Hard Hat Linux you can type 2092 2093 CROSS_COMPILE=ppc_8xx- MAKEALL 2094 2095or to build on a native PowerPC system you can type 2096 2097 CROSS_COMPILE=' ' MAKEALL 2098 2099See also "U-Boot Porting Guide" below. 2100 2101 2102Monitor Commands - Overview: 2103============================ 2104 2105go - start application at address 'addr' 2106run - run commands in an environment variable 2107bootm - boot application image from memory 2108bootp - boot image via network using BootP/TFTP protocol 2109tftpboot- boot image via network using TFTP protocol 2110 and env variables "ipaddr" and "serverip" 2111 (and eventually "gatewayip") 2112rarpboot- boot image via network using RARP/TFTP protocol 2113diskboot- boot from IDE devicebootd - boot default, i.e., run 'bootcmd' 2114loads - load S-Record file over serial line 2115loadb - load binary file over serial line (kermit mode) 2116md - memory display 2117mm - memory modify (auto-incrementing) 2118nm - memory modify (constant address) 2119mw - memory write (fill) 2120cp - memory copy 2121cmp - memory compare 2122crc32 - checksum calculation 2123imd - i2c memory display 2124imm - i2c memory modify (auto-incrementing) 2125inm - i2c memory modify (constant address) 2126imw - i2c memory write (fill) 2127icrc32 - i2c checksum calculation 2128iprobe - probe to discover valid I2C chip addresses 2129iloop - infinite loop on address range 2130isdram - print SDRAM configuration information 2131sspi - SPI utility commands 2132base - print or set address offset 2133printenv- print environment variables 2134setenv - set environment variables 2135saveenv - save environment variables to persistent storage 2136protect - enable or disable FLASH write protection 2137erase - erase FLASH memory 2138flinfo - print FLASH memory information 2139bdinfo - print Board Info structure 2140iminfo - print header information for application image 2141coninfo - print console devices and informations 2142ide - IDE sub-system 2143loop - infinite loop on address range 2144mtest - simple RAM test 2145icache - enable or disable instruction cache 2146dcache - enable or disable data cache 2147reset - Perform RESET of the CPU 2148echo - echo args to console 2149version - print monitor version 2150help - print online help 2151? - alias for 'help' 2152 2153 2154Monitor Commands - Detailed Description: 2155======================================== 2156 2157TODO. 2158 2159For now: just type "help <command>". 2160 2161 2162Environment Variables: 2163====================== 2164 2165U-Boot supports user configuration using Environment Variables which 2166can be made persistent by saving to Flash memory. 2167 2168Environment Variables are set using "setenv", printed using 2169"printenv", and saved to Flash using "saveenv". Using "setenv" 2170without a value can be used to delete a variable from the 2171environment. As long as you don't save the environment you are 2172working with an in-memory copy. In case the Flash area containing the 2173environment is erased by accident, a default environment is provided. 2174 2175Some configuration options can be set using Environment Variables: 2176 2177 baudrate - see CONFIG_BAUDRATE 2178 2179 bootdelay - see CONFIG_BOOTDELAY 2180 2181 bootcmd - see CONFIG_BOOTCOMMAND 2182 2183 bootargs - Boot arguments when booting an RTOS image 2184 2185 bootfile - Name of the image to load with TFTP 2186 2187 autoload - if set to "no" (any string beginning with 'n'), 2188 "bootp" will just load perform a lookup of the 2189 configuration from the BOOTP server, but not try to 2190 load any image using TFTP 2191 2192 autostart - if set to "yes", an image loaded using the "bootp", 2193 "rarpboot", "tftpboot" or "diskboot" commands will 2194 be automatically started (by internally calling 2195 "bootm") 2196 2197 If set to "no", a standalone image passed to the 2198 "bootm" command will be copied to the load address 2199 (and eventually uncompressed), but NOT be started. 2200 This can be used to load and uncompress arbitrary 2201 data. 2202 2203 initrd_high - restrict positioning of initrd images: 2204 If this variable is not set, initrd images will be 2205 copied to the highest possible address in RAM; this 2206 is usually what you want since it allows for 2207 maximum initrd size. If for some reason you want to 2208 make sure that the initrd image is loaded below the 2209 CFG_BOOTMAPSZ limit, you can set this environment 2210 variable to a value of "no" or "off" or "0". 2211 Alternatively, you can set it to a maximum upper 2212 address to use (U-Boot will still check that it 2213 does not overwrite the U-Boot stack and data). 2214 2215 For instance, when you have a system with 16 MB 2216 RAM, and want to reserve 4 MB from use by Linux, 2217 you can do this by adding "mem=12M" to the value of 2218 the "bootargs" variable. However, now you must make 2219 sure that the initrd image is placed in the first 2220 12 MB as well - this can be done with 2221 2222 setenv initrd_high 00c00000 2223 2224 If you set initrd_high to 0xFFFFFFFF, this is an 2225 indication to U-Boot that all addresses are legal 2226 for the Linux kernel, including addresses in flash 2227 memory. In this case U-Boot will NOT COPY the 2228 ramdisk at all. This may be useful to reduce the 2229 boot time on your system, but requires that this 2230 feature is supported by your Linux kernel. 2231 2232 ipaddr - IP address; needed for tftpboot command 2233 2234 loadaddr - Default load address for commands like "bootp", 2235 "rarpboot", "tftpboot", "loadb" or "diskboot" 2236 2237 loads_echo - see CONFIG_LOADS_ECHO 2238 2239 serverip - TFTP server IP address; needed for tftpboot command 2240 2241 bootretry - see CONFIG_BOOT_RETRY_TIME 2242 2243 bootdelaykey - see CONFIG_AUTOBOOT_DELAY_STR 2244 2245 bootstopkey - see CONFIG_AUTOBOOT_STOP_STR 2246 2247 2248The following environment variables may be used and automatically 2249updated by the network boot commands ("bootp" and "rarpboot"), 2250depending the information provided by your boot server: 2251 2252 bootfile - see above 2253 dnsip - IP address of your Domain Name Server 2254 dnsip2 - IP address of your secondary Domain Name Server 2255 gatewayip - IP address of the Gateway (Router) to use 2256 hostname - Target hostname 2257 ipaddr - see above 2258 netmask - Subnet Mask 2259 rootpath - Pathname of the root filesystem on the NFS server 2260 serverip - see above 2261 2262 2263There are two special Environment Variables: 2264 2265 serial# - contains hardware identification information such 2266 as type string and/or serial number 2267 ethaddr - Ethernet address 2268 2269These variables can be set only once (usually during manufacturing of 2270the board). U-Boot refuses to delete or overwrite these variables 2271once they have been set once. 2272 2273 2274Further special Environment Variables: 2275 2276 ver - Contains the U-Boot version string as printed 2277 with the "version" command. This variable is 2278 readonly (see CONFIG_VERSION_VARIABLE). 2279 2280 2281Please note that changes to some configuration parameters may take 2282only effect after the next boot (yes, that's just like Windoze :-). 2283 2284 2285Command Line Parsing: 2286===================== 2287 2288There are two different command line parsers available with U-Boot: 2289the old "simple" one, and the much more powerful "hush" shell: 2290 2291Old, simple command line parser: 2292-------------------------------- 2293 2294- supports environment variables (through setenv / saveenv commands) 2295- several commands on one line, separated by ';' 2296- variable substitution using "... $(name) ..." syntax 2297- special characters ('$', ';') can be escaped by prefixing with '\', 2298 for example: 2299 setenv bootcmd bootm \$(address) 2300- You can also escape text by enclosing in single apostrophes, for example: 2301 setenv addip 'setenv bootargs $bootargs ip=$ipaddr:$serverip:$gatewayip:$netmask:$hostname::off' 2302 2303Hush shell: 2304----------- 2305 2306- similar to Bourne shell, with control structures like 2307 if...then...else...fi, for...do...done; while...do...done, 2308 until...do...done, ... 2309- supports environment ("global") variables (through setenv / saveenv 2310 commands) and local shell variables (through standard shell syntax 2311 "name=value"); only environment variables can be used with "run" 2312 command 2313 2314General rules: 2315-------------- 2316 2317(1) If a command line (or an environment variable executed by a "run" 2318 command) contains several commands separated by semicolon, and 2319 one of these commands fails, then the remaining commands will be 2320 executed anyway. 2321 2322(2) If you execute several variables with one call to run (i. e. 2323 calling run with a list af variables as arguments), any failing 2324 command will cause "run" to terminate, i. e. the remaining 2325 variables are not executed. 2326 2327Note for Redundant Ethernet Interfaces: 2328======================================= 2329 2330Some boards come with redundant ethernet interfaces; U-Boot supports 2331such configurations and is capable of automatic selection of a 2332"working" interface when needed. MAC assignment works as follows: 2333 2334Network interfaces are numbered eth0, eth1, eth2, ... Corresponding 2335MAC addresses can be stored in the environment as "ethaddr" (=>eth0), 2336"eth1addr" (=>eth1), "eth2addr", ... 2337 2338If the network interface stores some valid MAC address (for instance 2339in SROM), this is used as default address if there is NO correspon- 2340ding setting in the environment; if the corresponding environment 2341variable is set, this overrides the settings in the card; that means: 2342 2343o If the SROM has a valid MAC address, and there is no address in the 2344 environment, the SROM's address is used. 2345 2346o If there is no valid address in the SROM, and a definition in the 2347 environment exists, then the value from the environment variable is 2348 used. 2349 2350o If both the SROM and the environment contain a MAC address, and 2351 both addresses are the same, this MAC address is used. 2352 2353o If both the SROM and the environment contain a MAC address, and the 2354 addresses differ, the value from the environment is used and a 2355 warning is printed. 2356 2357o If neither SROM nor the environment contain a MAC address, an error 2358 is raised. 2359 2360 2361Image Formats: 2362============== 2363 2364The "boot" commands of this monitor operate on "image" files which 2365can be basicly anything, preceeded by a special header; see the 2366definitions in include/image.h for details; basicly, the header 2367defines the following image properties: 2368 2369* Target Operating System (Provisions for OpenBSD, NetBSD, FreeBSD, 2370 4.4BSD, Linux, SVR4, Esix, Solaris, Irix, SCO, Dell, NCR, VxWorks, 2371 LynxOS, pSOS, QNX, RTEMS, ARTOS; 2372 Currently supported: Linux, NetBSD, VxWorks, QNX, RTEMS, ARTOS, LynxOS). 2373* Target CPU Architecture (Provisions for Alpha, ARM, Intel x86, 2374 IA64, MIPS, NIOS, PowerPC, IBM S390, SuperH, Sparc, Sparc 64 Bit; 2375 Currently supported: ARM, Intel x86, MIPS, NIOS, PowerPC). 2376* Compression Type (uncompressed, gzip, bzip2) 2377* Load Address 2378* Entry Point 2379* Image Name 2380* Image Timestamp 2381 2382The header is marked by a special Magic Number, and both the header 2383and the data portions of the image are secured against corruption by 2384CRC32 checksums. 2385 2386 2387Linux Support: 2388============== 2389 2390Although U-Boot should support any OS or standalone application 2391easily, the main focus has always been on Linux during the design of 2392U-Boot. 2393 2394U-Boot includes many features that so far have been part of some 2395special "boot loader" code within the Linux kernel. Also, any 2396"initrd" images to be used are no longer part of one big Linux image; 2397instead, kernel and "initrd" are separate images. This implementation 2398serves several purposes: 2399 2400- the same features can be used for other OS or standalone 2401 applications (for instance: using compressed images to reduce the 2402 Flash memory footprint) 2403 2404- it becomes much easier to port new Linux kernel versions because 2405 lots of low-level, hardware dependent stuff are done by U-Boot 2406 2407- the same Linux kernel image can now be used with different "initrd" 2408 images; of course this also means that different kernel images can 2409 be run with the same "initrd". This makes testing easier (you don't 2410 have to build a new "zImage.initrd" Linux image when you just 2411 change a file in your "initrd"). Also, a field-upgrade of the 2412 software is easier now. 2413 2414 2415Linux HOWTO: 2416============ 2417 2418Porting Linux to U-Boot based systems: 2419--------------------------------------- 2420 2421U-Boot cannot save you from doing all the necessary modifications to 2422configure the Linux device drivers for use with your target hardware 2423(no, we don't intend to provide a full virtual machine interface to 2424Linux :-). 2425 2426But now you can ignore ALL boot loader code (in arch/ppc/mbxboot). 2427 2428Just make sure your machine specific header file (for instance 2429include/asm-ppc/tqm8xx.h) includes the same definition of the Board 2430Information structure as we define in include/u-boot.h, and make 2431sure that your definition of IMAP_ADDR uses the same value as your 2432U-Boot configuration in CFG_IMMR. 2433 2434 2435Configuring the Linux kernel: 2436----------------------------- 2437 2438No specific requirements for U-Boot. Make sure you have some root 2439device (initial ramdisk, NFS) for your target system. 2440 2441 2442Building a Linux Image: 2443----------------------- 2444 2445With U-Boot, "normal" build targets like "zImage" or "bzImage" are 2446not used. If you use recent kernel source, a new build target 2447"uImage" will exist which automatically builds an image usable by 2448U-Boot. Most older kernels also have support for a "pImage" target, 2449which was introduced for our predecessor project PPCBoot and uses a 2450100% compatible format. 2451 2452Example: 2453 2454 make TQM850L_config 2455 make oldconfig 2456 make dep 2457 make uImage 2458 2459The "uImage" build target uses a special tool (in 'tools/mkimage') to 2460encapsulate a compressed Linux kernel image with header information, 2461CRC32 checksum etc. for use with U-Boot. This is what we are doing: 2462 2463* build a standard "vmlinux" kernel image (in ELF binary format): 2464 2465* convert the kernel into a raw binary image: 2466 2467 ${CROSS_COMPILE}-objcopy -O binary \ 2468 -R .note -R .comment \ 2469 -S vmlinux linux.bin 2470 2471* compress the binary image: 2472 2473 gzip -9 linux.bin 2474 2475* package compressed binary image for U-Boot: 2476 2477 mkimage -A ppc -O linux -T kernel -C gzip \ 2478 -a 0 -e 0 -n "Linux Kernel Image" \ 2479 -d linux.bin.gz uImage 2480 2481 2482The "mkimage" tool can also be used to create ramdisk images for use 2483with U-Boot, either separated from the Linux kernel image, or 2484combined into one file. "mkimage" encapsulates the images with a 64 2485byte header containing information about target architecture, 2486operating system, image type, compression method, entry points, time 2487stamp, CRC32 checksums, etc. 2488 2489"mkimage" can be called in two ways: to verify existing images and 2490print the header information, or to build new images. 2491 2492In the first form (with "-l" option) mkimage lists the information 2493contained in the header of an existing U-Boot image; this includes 2494checksum verification: 2495 2496 tools/mkimage -l image 2497 -l ==> list image header information 2498 2499The second form (with "-d" option) is used to build a U-Boot image 2500from a "data file" which is used as image payload: 2501 2502 tools/mkimage -A arch -O os -T type -C comp -a addr -e ep \ 2503 -n name -d data_file image 2504 -A ==> set architecture to 'arch' 2505 -O ==> set operating system to 'os' 2506 -T ==> set image type to 'type' 2507 -C ==> set compression type 'comp' 2508 -a ==> set load address to 'addr' (hex) 2509 -e ==> set entry point to 'ep' (hex) 2510 -n ==> set image name to 'name' 2511 -d ==> use image data from 'datafile' 2512 2513Right now, all Linux kernels use the same load address (0x00000000), 2514but the entry point address depends on the kernel version: 2515 2516- 2.2.x kernels have the entry point at 0x0000000C, 2517- 2.3.x and later kernels have the entry point at 0x00000000. 2518 2519So a typical call to build a U-Boot image would read: 2520 2521 -> tools/mkimage -n '2.4.4 kernel for TQM850L' \ 2522 > -A ppc -O linux -T kernel -C gzip -a 0 -e 0 \ 2523 > -d /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/ppc/coffboot/vmlinux.gz \ 2524 > examples/uImage.TQM850L 2525 Image Name: 2.4.4 kernel for TQM850L 2526 Created: Wed Jul 19 02:34:59 2000 2527 Image Type: PowerPC Linux Kernel Image (gzip compressed) 2528 Data Size: 335725 Bytes = 327.86 kB = 0.32 MB 2529 Load Address: 0x00000000 2530 Entry Point: 0x00000000 2531 2532To verify the contents of the image (or check for corruption): 2533 2534 -> tools/mkimage -l examples/uImage.TQM850L 2535 Image Name: 2.4.4 kernel for TQM850L 2536 Created: Wed Jul 19 02:34:59 2000 2537 Image Type: PowerPC Linux Kernel Image (gzip compressed) 2538 Data Size: 335725 Bytes = 327.86 kB = 0.32 MB 2539 Load Address: 0x00000000 2540 Entry Point: 0x00000000 2541 2542NOTE: for embedded systems where boot time is critical you can trade 2543speed for memory and install an UNCOMPRESSED image instead: this 2544needs more space in Flash, but boots much faster since it does not 2545need to be uncompressed: 2546 2547 -> gunzip /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/ppc/coffboot/vmlinux.gz 2548 -> tools/mkimage -n '2.4.4 kernel for TQM850L' \ 2549 > -A ppc -O linux -T kernel -C none -a 0 -e 0 \ 2550 > -d /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/ppc/coffboot/vmlinux \ 2551 > examples/uImage.TQM850L-uncompressed 2552 Image Name: 2.4.4 kernel for TQM850L 2553 Created: Wed Jul 19 02:34:59 2000 2554 Image Type: PowerPC Linux Kernel Image (uncompressed) 2555 Data Size: 792160 Bytes = 773.59 kB = 0.76 MB 2556 Load Address: 0x00000000 2557 Entry Point: 0x00000000 2558 2559 2560Similar you can build U-Boot images from a 'ramdisk.image.gz' file 2561when your kernel is intended to use an initial ramdisk: 2562 2563 -> tools/mkimage -n 'Simple Ramdisk Image' \ 2564 > -A ppc -O linux -T ramdisk -C gzip \ 2565 > -d /LinuxPPC/images/SIMPLE-ramdisk.image.gz examples/simple-initrd 2566 Image Name: Simple Ramdisk Image 2567 Created: Wed Jan 12 14:01:50 2000 2568 Image Type: PowerPC Linux RAMDisk Image (gzip compressed) 2569 Data Size: 566530 Bytes = 553.25 kB = 0.54 MB 2570 Load Address: 0x00000000 2571 Entry Point: 0x00000000 2572 2573 2574Installing a Linux Image: 2575------------------------- 2576 2577To downloading a U-Boot image over the serial (console) interface, 2578you must convert the image to S-Record format: 2579 2580 objcopy -I binary -O srec examples/image examples/image.srec 2581 2582The 'objcopy' does not understand the information in the U-Boot 2583image header, so the resulting S-Record file will be relative to 2584address 0x00000000. To load it to a given address, you need to 2585specify the target address as 'offset' parameter with the 'loads' 2586command. 2587 2588Example: install the image to address 0x40100000 (which on the 2589TQM8xxL is in the first Flash bank): 2590 2591 => erase 40100000 401FFFFF 2592 2593 .......... done 2594 Erased 8 sectors 2595 2596 => loads 40100000 2597 ## Ready for S-Record download ... 2598 ~>examples/image.srec 2599 1 2 3 4 5 6 7 8 9 10 11 12 13 ... 2600 ... 2601 15989 15990 15991 15992 2602 [file transfer complete] 2603 [connected] 2604 ## Start Addr = 0x00000000 2605 2606 2607You can check the success of the download using the 'iminfo' command; 2608this includes a checksum verification so you can be sure no data 2609corruption happened: 2610 2611 => imi 40100000 2612 2613 ## Checking Image at 40100000 ... 2614 Image Name: 2.2.13 for initrd on TQM850L 2615 Image Type: PowerPC Linux Kernel Image (gzip compressed) 2616 Data Size: 335725 Bytes = 327 kB = 0 MB 2617 Load Address: 00000000 2618 Entry Point: 0000000c 2619 Verifying Checksum ... OK 2620 2621 2622Boot Linux: 2623----------- 2624 2625The "bootm" command is used to boot an application that is stored in 2626memory (RAM or Flash). In case of a Linux kernel image, the contents 2627of the "bootargs" environment variable is passed to the kernel as 2628parameters. You can check and modify this variable using the 2629"printenv" and "setenv" commands: 2630 2631 2632 => printenv bootargs 2633 bootargs=root=/dev/ram 2634 2635 => setenv bootargs root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2 2636 2637 => printenv bootargs 2638 bootargs=root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2 2639 2640 => bootm 40020000 2641 ## Booting Linux kernel at 40020000 ... 2642 Image Name: 2.2.13 for NFS on TQM850L 2643 Image Type: PowerPC Linux Kernel Image (gzip compressed) 2644 Data Size: 381681 Bytes = 372 kB = 0 MB 2645 Load Address: 00000000 2646 Entry Point: 0000000c 2647 Verifying Checksum ... OK 2648 Uncompressing Kernel Image ... OK 2649 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 2650 Boot arguments: root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2 2651 time_init: decrementer frequency = 187500000/60 2652 Calibrating delay loop... 49.77 BogoMIPS 2653 Memory: 15208k available (700k kernel code, 444k data, 32k init) [c0000000,c1000000] 2654 ... 2655 2656If you want to boot a Linux kernel with initial ram disk, you pass 2657the memory addresses of both the kernel and the initrd image (PPBCOOT 2658format!) to the "bootm" command: 2659 2660 => imi 40100000 40200000 2661 2662 ## Checking Image at 40100000 ... 2663 Image Name: 2.2.13 for initrd on TQM850L 2664 Image Type: PowerPC Linux Kernel Image (gzip compressed) 2665 Data Size: 335725 Bytes = 327 kB = 0 MB 2666 Load Address: 00000000 2667 Entry Point: 0000000c 2668 Verifying Checksum ... OK 2669 2670 ## Checking Image at 40200000 ... 2671 Image Name: Simple Ramdisk Image 2672 Image Type: PowerPC Linux RAMDisk Image (gzip compressed) 2673 Data Size: 566530 Bytes = 553 kB = 0 MB 2674 Load Address: 00000000 2675 Entry Point: 00000000 2676 Verifying Checksum ... OK 2677 2678 => bootm 40100000 40200000 2679 ## Booting Linux kernel at 40100000 ... 2680 Image Name: 2.2.13 for initrd on TQM850L 2681 Image Type: PowerPC Linux Kernel Image (gzip compressed) 2682 Data Size: 335725 Bytes = 327 kB = 0 MB 2683 Load Address: 00000000 2684 Entry Point: 0000000c 2685 Verifying Checksum ... OK 2686 Uncompressing Kernel Image ... OK 2687 ## Loading RAMDisk Image at 40200000 ... 2688 Image Name: Simple Ramdisk Image 2689 Image Type: PowerPC Linux RAMDisk Image (gzip compressed) 2690 Data Size: 566530 Bytes = 553 kB = 0 MB 2691 Load Address: 00000000 2692 Entry Point: 00000000 2693 Verifying Checksum ... OK 2694 Loading Ramdisk ... OK 2695 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 2696 Boot arguments: root=/dev/ram 2697 time_init: decrementer frequency = 187500000/60 2698 Calibrating delay loop... 49.77 BogoMIPS 2699 ... 2700 RAMDISK: Compressed image found at block 0 2701 VFS: Mounted root (ext2 filesystem). 2702 2703 bash# 2704 2705More About U-Boot Image Types: 2706------------------------------ 2707 2708U-Boot supports the following image types: 2709 2710 "Standalone Programs" are directly runnable in the environment 2711 provided by U-Boot; it is expected that (if they behave 2712 well) you can continue to work in U-Boot after return from 2713 the Standalone Program. 2714 "OS Kernel Images" are usually images of some Embedded OS which 2715 will take over control completely. Usually these programs 2716 will install their own set of exception handlers, device 2717 drivers, set up the MMU, etc. - this means, that you cannot 2718 expect to re-enter U-Boot except by resetting the CPU. 2719 "RAMDisk Images" are more or less just data blocks, and their 2720 parameters (address, size) are passed to an OS kernel that is 2721 being started. 2722 "Multi-File Images" contain several images, typically an OS 2723 (Linux) kernel image and one or more data images like 2724 RAMDisks. This construct is useful for instance when you want 2725 to boot over the network using BOOTP etc., where the boot 2726 server provides just a single image file, but you want to get 2727 for instance an OS kernel and a RAMDisk image. 2728 2729 "Multi-File Images" start with a list of image sizes, each 2730 image size (in bytes) specified by an "uint32_t" in network 2731 byte order. This list is terminated by an "(uint32_t)0". 2732 Immediately after the terminating 0 follow the images, one by 2733 one, all aligned on "uint32_t" boundaries (size rounded up to 2734 a multiple of 4 bytes). 2735 2736 "Firmware Images" are binary images containing firmware (like 2737 U-Boot or FPGA images) which usually will be programmed to 2738 flash memory. 2739 2740 "Script files" are command sequences that will be executed by 2741 U-Boot's command interpreter; this feature is especially 2742 useful when you configure U-Boot to use a real shell (hush) 2743 as command interpreter. 2744 2745 2746Standalone HOWTO: 2747================= 2748 2749One of the features of U-Boot is that you can dynamically load and 2750run "standalone" applications, which can use some resources of 2751U-Boot like console I/O functions or interrupt services. 2752 2753Two simple examples are included with the sources: 2754 2755"Hello World" Demo: 2756------------------- 2757 2758'examples/hello_world.c' contains a small "Hello World" Demo 2759application; it is automatically compiled when you build U-Boot. 2760It's configured to run at address 0x00040004, so you can play with it 2761like that: 2762 2763 => loads 2764 ## Ready for S-Record download ... 2765 ~>examples/hello_world.srec 2766 1 2 3 4 5 6 7 8 9 10 11 ... 2767 [file transfer complete] 2768 [connected] 2769 ## Start Addr = 0x00040004 2770 2771 => go 40004 Hello World! This is a test. 2772 ## Starting application at 0x00040004 ... 2773 Hello World 2774 argc = 7 2775 argv[0] = "40004" 2776 argv[1] = "Hello" 2777 argv[2] = "World!" 2778 argv[3] = "This" 2779 argv[4] = "is" 2780 argv[5] = "a" 2781 argv[6] = "test." 2782 argv[7] = "<NULL>" 2783 Hit any key to exit ... 2784 2785 ## Application terminated, rc = 0x0 2786 2787Another example, which demonstrates how to register a CPM interrupt 2788handler with the U-Boot code, can be found in 'examples/timer.c'. 2789Here, a CPM timer is set up to generate an interrupt every second. 2790The interrupt service routine is trivial, just printing a '.' 2791character, but this is just a demo program. The application can be 2792controlled by the following keys: 2793 2794 ? - print current values og the CPM Timer registers 2795 b - enable interrupts and start timer 2796 e - stop timer and disable interrupts 2797 q - quit application 2798 2799 => loads 2800 ## Ready for S-Record download ... 2801 ~>examples/timer.srec 2802 1 2 3 4 5 6 7 8 9 10 11 ... 2803 [file transfer complete] 2804 [connected] 2805 ## Start Addr = 0x00040004 2806 2807 => go 40004 2808 ## Starting application at 0x00040004 ... 2809 TIMERS=0xfff00980 2810 Using timer 1 2811 tgcr @ 0xfff00980, tmr @ 0xfff00990, trr @ 0xfff00994, tcr @ 0xfff00998, tcn @ 0xfff0099c, ter @ 0xfff009b0 2812 2813Hit 'b': 2814 [q, b, e, ?] Set interval 1000000 us 2815 Enabling timer 2816Hit '?': 2817 [q, b, e, ?] ........ 2818 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0xef6, ter=0x0 2819Hit '?': 2820 [q, b, e, ?] . 2821 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x2ad4, ter=0x0 2822Hit '?': 2823 [q, b, e, ?] . 2824 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x1efc, ter=0x0 2825Hit '?': 2826 [q, b, e, ?] . 2827 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x169d, ter=0x0 2828Hit 'e': 2829 [q, b, e, ?] ...Stopping timer 2830Hit 'q': 2831 [q, b, e, ?] ## Application terminated, rc = 0x0 2832 2833 2834Minicom warning: 2835================ 2836 2837Over time, many people have reported problems when trying to use the 2838"minicom" terminal emulation program for serial download. I (wd) 2839consider minicom to be broken, and recommend not to use it. Under 2840Unix, I recommend to use C-Kermit for general purpose use (and 2841especially for kermit binary protocol download ("loadb" command), and 2842use "cu" for S-Record download ("loads" command). 2843 2844Nevertheless, if you absolutely want to use it try adding this 2845configuration to your "File transfer protocols" section: 2846 2847 Name Program Name U/D FullScr IO-Red. Multi 2848 X kermit /usr/bin/kermit -i -l %l -s Y U Y N N 2849 Y kermit /usr/bin/kermit -i -l %l -r N D Y N N 2850 2851 2852NetBSD Notes: 2853============= 2854 2855Starting at version 0.9.2, U-Boot supports NetBSD both as host 2856(build U-Boot) and target system (boots NetBSD/mpc8xx). 2857 2858Building requires a cross environment; it is known to work on 2859NetBSD/i386 with the cross-powerpc-netbsd-1.3 package (you will also 2860need gmake since the Makefiles are not compatible with BSD make). 2861Note that the cross-powerpc package does not install include files; 2862attempting to build U-Boot will fail because <machine/ansi.h> is 2863missing. This file has to be installed and patched manually: 2864 2865 # cd /usr/pkg/cross/powerpc-netbsd/include 2866 # mkdir powerpc 2867 # ln -s powerpc machine 2868 # cp /usr/src/sys/arch/powerpc/include/ansi.h powerpc/ansi.h 2869 # ${EDIT} powerpc/ansi.h ## must remove __va_list, _BSD_VA_LIST 2870 2871Native builds *don't* work due to incompatibilities between native 2872and U-Boot include files. 2873 2874Booting assumes that (the first part of) the image booted is a 2875stage-2 loader which in turn loads and then invokes the kernel 2876proper. Loader sources will eventually appear in the NetBSD source 2877tree (probably in sys/arc/mpc8xx/stand/u-boot_stage2/); in the 2878meantime, send mail to bruno@exet-ag.de and/or wd@denx.de for 2879details. 2880 2881 2882Implementation Internals: 2883========================= 2884 2885The following is not intended to be a complete description of every 2886implementation detail. However, it should help to understand the 2887inner workings of U-Boot and make it easier to port it to custom 2888hardware. 2889 2890 2891Initial Stack, Global Data: 2892--------------------------- 2893 2894The implementation of U-Boot is complicated by the fact that U-Boot 2895starts running out of ROM (flash memory), usually without access to 2896system RAM (because the memory controller is not initialized yet). 2897This means that we don't have writable Data or BSS segments, and BSS 2898is not initialized as zero. To be able to get a C environment working 2899at all, we have to allocate at least a minimal stack. Implementation 2900options for this are defined and restricted by the CPU used: Some CPU 2901models provide on-chip memory (like the IMMR area on MPC8xx and 2902MPC826x processors), on others (parts of) the data cache can be 2903locked as (mis-) used as memory, etc. 2904 2905 Chris Hallinan posted a good summary of these issues to the 2906 u-boot-users mailing list: 2907 2908 Subject: RE: [U-Boot-Users] RE: More On Memory Bank x (nothingness)? 2909 From: "Chris Hallinan" <clh@net1plus.com> 2910 Date: Mon, 10 Feb 2003 16:43:46 -0500 (22:43 MET) 2911 ... 2912 2913 Correct me if I'm wrong, folks, but the way I understand it 2914 is this: Using DCACHE as initial RAM for Stack, etc, does not 2915 require any physical RAM backing up the cache. The cleverness 2916 is that the cache is being used as a temporary supply of 2917 necessary storage before the SDRAM controller is setup. It's 2918 beyond the scope of this list to expain the details, but you 2919 can see how this works by studying the cache architecture and 2920 operation in the architecture and processor-specific manuals. 2921 2922 OCM is On Chip Memory, which I believe the 405GP has 4K. It 2923 is another option for the system designer to use as an 2924 initial stack/ram area prior to SDRAM being available. Either 2925 option should work for you. Using CS 4 should be fine if your 2926 board designers haven't used it for something that would 2927 cause you grief during the initial boot! It is frequently not 2928 used. 2929 2930 CFG_INIT_RAM_ADDR should be somewhere that won't interfere 2931 with your processor/board/system design. The default value 2932 you will find in any recent u-boot distribution in 2933 Walnut405.h should work for you. I'd set it to a value larger 2934 than your SDRAM module. If you have a 64MB SDRAM module, set 2935 it above 400_0000. Just make sure your board has no resources 2936 that are supposed to respond to that address! That code in 2937 start.S has been around a while and should work as is when 2938 you get the config right. 2939 2940 -Chris Hallinan 2941 DS4.COM, Inc. 2942 2943It is essential to remember this, since it has some impact on the C 2944code for the initialization procedures: 2945 2946* Initialized global data (data segment) is read-only. Do not attempt 2947 to write it. 2948 2949* Do not use any unitialized global data (or implicitely initialized 2950 as zero data - BSS segment) at all - this is undefined, initiali- 2951 zation is performed later (when relocating to RAM). 2952 2953* Stack space is very limited. Avoid big data buffers or things like 2954 that. 2955 2956Having only the stack as writable memory limits means we cannot use 2957normal global data to share information beween the code. But it 2958turned out that the implementation of U-Boot can be greatly 2959simplified by making a global data structure (gd_t) available to all 2960functions. We could pass a pointer to this data as argument to _all_ 2961functions, but this would bloat the code. Instead we use a feature of 2962the GCC compiler (Global Register Variables) to share the data: we 2963place a pointer (gd) to the global data into a register which we 2964reserve for this purpose. 2965 2966When choosing a register for such a purpose we are restricted by the 2967relevant (E)ABI specifications for the current architecture, and by 2968GCC's implementation. 2969 2970For PowerPC, the following registers have specific use: 2971 R1: stack pointer 2972 R2: TOC pointer 2973 R3-R4: parameter passing and return values 2974 R5-R10: parameter passing 2975 R13: small data area pointer 2976 R30: GOT pointer 2977 R31: frame pointer 2978 2979 (U-Boot also uses R14 as internal GOT pointer.) 2980 2981 ==> U-Boot will use R29 to hold a pointer to the global data 2982 2983 Note: on PPC, we could use a static initializer (since the 2984 address of the global data structure is known at compile time), 2985 but it turned out that reserving a register results in somewhat 2986 smaller code - although the code savings are not that big (on 2987 average for all boards 752 bytes for the whole U-Boot image, 2988 624 text + 127 data). 2989 2990On ARM, the following registers are used: 2991 2992 R0: function argument word/integer result 2993 R1-R3: function argument word 2994 R9: GOT pointer 2995 R10: stack limit (used only if stack checking if enabled) 2996 R11: argument (frame) pointer 2997 R12: temporary workspace 2998 R13: stack pointer 2999 R14: link register 3000 R15: program counter 3001 3002 ==> U-Boot will use R8 to hold a pointer to the global data 3003 3004 3005Memory Management: 3006------------------ 3007 3008U-Boot runs in system state and uses physical addresses, i.e. the 3009MMU is not used either for address mapping nor for memory protection. 3010 3011The available memory is mapped to fixed addresses using the memory 3012controller. In this process, a contiguous block is formed for each 3013memory type (Flash, SDRAM, SRAM), even when it consists of several 3014physical memory banks. 3015 3016U-Boot is installed in the first 128 kB of the first Flash bank (on 3017TQM8xxL modules this is the range 0x40000000 ... 0x4001FFFF). After 3018booting and sizing and initializing DRAM, the code relocates itself 3019to the upper end of DRAM. Immediately below the U-Boot code some 3020memory is reserved for use by malloc() [see CFG_MALLOC_LEN 3021configuration setting]. Below that, a structure with global Board 3022Info data is placed, followed by the stack (growing downward). 3023 3024Additionally, some exception handler code is copied to the low 8 kB 3025of DRAM (0x00000000 ... 0x00001FFF). 3026 3027So a typical memory configuration with 16 MB of DRAM could look like 3028this: 3029 3030 0x0000 0000 Exception Vector code 3031 : 3032 0x0000 1FFF 3033 0x0000 2000 Free for Application Use 3034 : 3035 : 3036 3037 : 3038 : 3039 0x00FB FF20 Monitor Stack (Growing downward) 3040 0x00FB FFAC Board Info Data and permanent copy of global data 3041 0x00FC 0000 Malloc Arena 3042 : 3043 0x00FD FFFF 3044 0x00FE 0000 RAM Copy of Monitor Code 3045 ... eventually: LCD or video framebuffer 3046 ... eventually: pRAM (Protected RAM - unchanged by reset) 3047 0x00FF FFFF [End of RAM] 3048 3049 3050System Initialization: 3051---------------------- 3052 3053In the reset configuration, U-Boot starts at the reset entry point 3054(on most PowerPC systens at address 0x00000100). Because of the reset 3055configuration for CS0# this is a mirror of the onboard Flash memory. 3056To be able to re-map memory U-Boot then jumps to its link address. 3057To be able to implement the initialization code in C, a (small!) 3058initial stack is set up in the internal Dual Ported RAM (in case CPUs 3059which provide such a feature like MPC8xx or MPC8260), or in a locked 3060part of the data cache. After that, U-Boot initializes the CPU core, 3061the caches and the SIU. 3062 3063Next, all (potentially) available memory banks are mapped using a 3064preliminary mapping. For example, we put them on 512 MB boundaries 3065(multiples of 0x20000000: SDRAM on 0x00000000 and 0x20000000, Flash 3066on 0x40000000 and 0x60000000, SRAM on 0x80000000). Then UPM A is 3067programmed for SDRAM access. Using the temporary configuration, a 3068simple memory test is run that determines the size of the SDRAM 3069banks. 3070 3071When there is more than one SDRAM bank, and the banks are of 3072different size, the largest is mapped first. For equal size, the first 3073bank (CS2#) is mapped first. The first mapping is always for address 30740x00000000, with any additional banks following immediately to create 3075contiguous memory starting from 0. 3076 3077Then, the monitor installs itself at the upper end of the SDRAM area 3078and allocates memory for use by malloc() and for the global Board 3079Info data; also, the exception vector code is copied to the low RAM 3080pages, and the final stack is set up. 3081 3082Only after this relocation will you have a "normal" C environment; 3083until that you are restricted in several ways, mostly because you are 3084running from ROM, and because the code will have to be relocated to a 3085new address in RAM. 3086 3087 3088U-Boot Porting Guide: 3089---------------------- 3090 3091[Based on messages by Jerry Van Baren in the U-Boot-Users mailing 3092list, October 2002] 3093 3094 3095int main (int argc, char *argv[]) 3096{ 3097 sighandler_t no_more_time; 3098 3099 signal (SIGALRM, no_more_time); 3100 alarm (PROJECT_DEADLINE - toSec (3 * WEEK)); 3101 3102 if (available_money > available_manpower) { 3103 pay consultant to port U-Boot; 3104 return 0; 3105 } 3106 3107 Download latest U-Boot source; 3108 3109 Subscribe to u-boot-users mailing list; 3110 3111 if (clueless) { 3112 email ("Hi, I am new to U-Boot, how do I get started?"); 3113 } 3114 3115 while (learning) { 3116 Read the README file in the top level directory; 3117 Read http://www.denx.de/twiki/bin/view/DULG/Manual ; 3118 Read the source, Luke; 3119 } 3120 3121 if (available_money > toLocalCurrency ($2500)) { 3122 Buy a BDI2000; 3123 } else { 3124 Add a lot of aggravation and time; 3125 } 3126 3127 Create your own board support subdirectory; 3128 3129 Create your own board config file; 3130 3131 while (!running) { 3132 do { 3133 Add / modify source code; 3134 } until (compiles); 3135 Debug; 3136 if (clueless) 3137 email ("Hi, I am having problems..."); 3138 } 3139 Send patch file to Wolfgang; 3140 3141 return 0; 3142} 3143 3144void no_more_time (int sig) 3145{ 3146 hire_a_guru(); 3147} 3148 3149 3150Coding Standards: 3151----------------- 3152 3153All contributions to U-Boot should conform to the Linux kernel 3154coding style; see the file "Documentation/CodingStyle" in your Linux 3155kernel source directory. 3156 3157Please note that U-Boot is implemented in C (and to some small parts 3158in Assembler); no C++ is used, so please do not use C++ style 3159comments (//) in your code. 3160 3161Submissions which do not conform to the standards may be returned 3162with a request to reformat the changes. 3163 3164 3165Submitting Patches: 3166------------------- 3167 3168Since the number of patches for U-Boot is growing, we need to 3169establish some rules. Submissions which do not conform to these rules 3170may be rejected, even when they contain important and valuable stuff. 3171 3172 3173When you send a patch, please include the following information with 3174it: 3175 3176* For bug fixes: a description of the bug and how your patch fixes 3177 this bug. Please try to include a way of demonstrating that the 3178 patch actually fixes something. 3179 3180* For new features: a description of the feature and your 3181 implementation. 3182 3183* A CHANGELOG entry as plaintext (separate from the patch) 3184 3185* For major contributions, your entry to the CREDITS file 3186 3187* When you add support for a new board, don't forget to add this 3188 board to the MAKEALL script, too. 3189 3190* If your patch adds new configuration options, don't forget to 3191 document these in the README file. 3192 3193* The patch itself. If you are accessing the CVS repository use "cvs 3194 update; cvs diff -puRN"; else, use "diff -purN OLD NEW". If your 3195 version of diff does not support these options, then get the latest 3196 version of GNU diff. 3197 3198 The current directory when running this command shall be the top 3199 level directory of the U-Boot source tree, or it's parent directory 3200 (i. e. please make sure that your patch includes sufficient 3201 directory information for the affected files). 3202 3203 We accept patches as plain text, MIME attachments or as uuencoded 3204 gzipped text. 3205 3206* If one logical set of modifications affects or creates several 3207 files, all these changes shall be submitted in a SINGLE patch file. 3208 3209* Changesets that contain different, unrelated modifications shall be 3210 submitted as SEPARATE patches, one patch per changeset. 3211 3212 3213Notes: 3214 3215* Before sending the patch, run the MAKEALL script on your patched 3216 source tree and make sure that no errors or warnings are reported 3217 for any of the boards. 3218 3219* Keep your modifications to the necessary minimum: A patch 3220 containing several unrelated changes or arbitrary reformats will be 3221 returned with a request to re-formatting / split it. 3222 3223* If you modify existing code, make sure that your new code does not 3224 add to the memory footprint of the code ;-) Small is beautiful! 3225 When adding new features, these should compile conditionally only 3226 (using #ifdef), and the resulting code with the new feature 3227 disabled must not need more memory than the old code without your 3228 modification. 3229