1# 2# (C) Copyright 2000 - 2002 3# Wolfgang Denk, DENX Software Engineering, wd@denx.de. 4# 5# See file CREDITS for list of people who contributed to this 6# project. 7# 8# This program is free software; you can redistribute it and/or 9# modify it under the terms of the GNU General Public License as 10# published by the Free Software Foundation; either version 2 of 11# the License, or (at your option) any later version. 12# 13# This program is distributed in the hope that it will be useful, 14# but WITHOUT ANY WARRANTY; without even the implied warranty of 15# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 16# GNU General Public License for more details. 17# 18# You should have received a copy of the GNU General Public License 19# along with this program; if not, write to the Free Software 20# Foundation, Inc., 59 Temple Place, Suite 330, Boston, 21# MA 02111-1307 USA 22# 23 24Summary: 25======== 26 27This directory contains the source code for U-Boot, a boot loader for 28Embedded boards based on PowerPC and ARM processors, which can be 29installed in a boot ROM and used to initialize and test the hardware 30or to download and run application code. 31 32The development of U-Boot is closely related to Linux: some parts of 33the source code originate in the Linux source tree, we have some 34header files in common, and special provision has been made to 35support booting of Linux images. 36 37Some attention has been paid to make this software easily 38configurable and extendable. For instance, all monitor commands are 39implemented with the same call interface, so that it's very easy to 40add new commands. Also, instead of permanently adding rarely used 41code (for instance hardware test utilities) to the monitor, you can 42load and run it dynamically. 43 44 45Status: 46======= 47 48In general, all boards for which a configuration option exists in the 49Makefile have been tested to some extent and can be considered 50"working". In fact, many of them are used in production systems. 51 52In case of problems see the CHANGELOG and CREDITS files to find out 53who contributed the specific port. 54 55 56Where to get help: 57================== 58 59In case you have questions about, problems with or contributions for 60U-Boot you should send a message to the U-Boot mailing list at 61<u-boot-users@lists.sourceforge.net>. There is also an archive of 62previous traffic on the mailing list - please search the archive 63before asking FAQ's. Please see 64http://lists.sourceforge.net/lists/listinfo/u-boot-users/ 65 66 67Where we come from: 68=================== 69 70- start from 8xxrom sources 71- create PPCBoot project (http://sourceforge.net/projects/ppcboot) 72- clean up code 73- make it easier to add custom boards 74- make it possible to add other [PowerPC] CPUs 75- extend functions, especially: 76 * Provide extended interface to Linux boot loader 77 * S-Record download 78 * network boot 79 * PCMCIA / CompactFLash / ATA disk / SCSI ... boot 80- create ARMBoot project (http://sourceforge.net/projects/armboot) 81- add other CPU families (starting with ARM) 82- create U-Boot project (http://sourceforge.net/projects/u-boot) 83 84 85Names and Spelling: 86=================== 87 88The "official" name of this project is "Das U-Boot". The spelling 89"U-Boot" shall be used in all written text (documentation, comments 90in source files etc.). Example: 91 92 This is the README file for the U-Boot project. 93 94File names etc. shall be based on the string "u-boot". Examples: 95 96 include/asm-ppc/u-boot.h 97 98 #include <asm/u-boot.h> 99 100Variable names, preprocessor constants etc. shall be either based on 101the string "u_boot" or on "U_BOOT". Example: 102 103 U_BOOT_VERSION u_boot_logo 104 IH_OS_U_BOOT u_boot_hush_start 105 106 107Versioning: 108=========== 109 110U-Boot uses a 3 level version number containing a version, a 111sub-version, and a patchlevel: "U-Boot-2.34.5" means version "2", 112sub-version "34", and patchlevel "4". 113 114The patchlevel is used to indicate certain stages of development 115between released versions, i. e. officially released versions of 116U-Boot will always have a patchlevel of "0". 117 118 119Directory Hierarchy: 120==================== 121 122- board Board 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/ppc4xx Files specific to IBM 4xx CPUs 150 151 152- board/LEOX/ Files specific to boards manufactured by The LEOX team 153- board/LEOX/elpt860 Files specific to ELPT860 boards 154- board/RPXClassic 155 Files specific to RPXClassic boards 156- board/RPXlite Files specific to RPXlite boards 157- board/at91rm9200dk Files specific to AT91RM9200DK boards 158- board/c2mon Files specific to c2mon boards 159- board/cmi Files specific to cmi boards 160- board/cogent Files specific to Cogent boards 161 (need further configuration) 162 Files specific to CPCIISER4 boards 163- board/cpu86 Files specific to CPU86 boards 164- board/cray/ Files specific to boards manufactured by Cray 165- board/cray/L1 Files specific to L1 boards 166- board/cu824 Files specific to CU824 boards 167- board/ebony Files specific to IBM Ebony board 168- board/eric Files specific to ERIC boards 169- board/esd/ Files specific to boards manufactured by ESD 170- board/esd/adciop Files specific to ADCIOP boards 171- board/esd/ar405 Files specific to AR405 boards 172- board/esd/canbt Files specific to CANBT boards 173- board/esd/cpci405 Files specific to CPCI405 boards 174- board/esd/cpciiser4 Files specific to CPCIISER4 boards 175- board/esd/common Common files for ESD boards 176- board/esd/dasa_sim Files specific to DASA_SIM boards 177- board/esd/du405 Files specific to DU405 boards 178- board/esd/ocrtc Files specific to OCRTC boards 179- board/esd/pci405 Files specific to PCI405 boards 180- board/esteem192e 181 Files specific to ESTEEM192E boards 182- board/etx094 Files specific to ETX_094 boards 183- board/evb64260 184 Files specific to EVB64260 boards 185- board/fads Files specific to FADS boards 186- board/flagadm Files specific to FLAGADM boards 187- board/gen860t Files specific to GEN860T and GEN860T_SC boards 188- board/genietv Files specific to GENIETV boards 189- board/gth Files specific to GTH boards 190- board/hermes Files specific to HERMES boards 191- board/hymod Files specific to HYMOD boards 192- board/icu862 Files specific to ICU862 boards 193- board/ip860 Files specific to IP860 boards 194- board/iphase4539 195 Files specific to Interphase4539 boards 196- board/ivm Files specific to IVMS8/IVML24 boards 197- board/lantec Files specific to LANTEC boards 198- board/lwmon Files specific to LWMON boards 199- board/mbx8xx Files specific to MBX boards 200- board/mpc8260ads 201 Files specific to MPC8260ADS and PQ2FADS-ZU boards 202- board/mpl/ Files specific to boards manufactured by MPL 203- board/mpl/common Common files for MPL boards 204- board/mpl/pip405 Files specific to PIP405 boards 205- board/mpl/mip405 Files specific to MIP405 boards 206- board/mpl/vcma9 Files specific to VCMA9 boards 207- board/musenki Files specific to MUSEKNI boards 208- board/mvs1 Files specific to MVS1 boards 209- board/nx823 Files specific to NX823 boards 210- board/oxc Files specific to OXC boards 211- board/omap1510inn 212 Files specific to OMAP 1510 Innovator boards 213- board/omap1610inn 214 Files specific to OMAP 1610 Innovator boards 215- board/pcippc2 Files specific to PCIPPC2/PCIPPC6 boards 216- board/pm826 Files specific to PM826 boards 217- board/ppmc8260 218 Files specific to PPMC8260 boards 219- board/rpxsuper 220 Files specific to RPXsuper boards 221- board/rsdproto 222 Files specific to RSDproto boards 223- board/sandpoint 224 Files specific to Sandpoint boards 225- board/sbc8260 Files specific to SBC8260 boards 226- board/sacsng Files specific to SACSng boards 227- board/siemens Files specific to boards manufactured by Siemens AG 228- board/siemens/CCM Files specific to CCM boards 229- board/siemens/IAD210 Files specific to IAD210 boards 230- board/siemens/SCM Files specific to SCM boards 231- board/siemens/pcu_e Files specific to PCU_E boards 232- board/sixnet Files specific to SIXNET boards 233- board/spd8xx Files specific to SPD8xxTS boards 234- board/tqm8260 Files specific to TQM8260 boards 235- board/tqm8xx Files specific to TQM8xxL boards 236- board/w7o Files specific to W7O boards 237- board/walnut405 238 Files specific to Walnut405 boards 239- board/westel/ Files specific to boards manufactured by Westel Wireless 240- board/westel/amx860 Files specific to AMX860 boards 241- board/utx8245 Files specific to UTX8245 boards 242 243Software Configuration: 244======================= 245 246Configuration is usually done using C preprocessor defines; the 247rationale behind that is to avoid dead code whenever possible. 248 249There are two classes of configuration variables: 250 251* Configuration _OPTIONS_: 252 These are selectable by the user and have names beginning with 253 "CONFIG_". 254 255* Configuration _SETTINGS_: 256 These depend on the hardware etc. and should not be meddled with if 257 you don't know what you're doing; they have names beginning with 258 "CFG_". 259 260Later we will add a configuration tool - probably similar to or even 261identical to what's used for the Linux kernel. Right now, we have to 262do the configuration by hand, which means creating some symbolic 263links and editing some configuration files. We use the TQM8xxL boards 264as an example here. 265 266 267Selection of Processor Architecture and Board Type: 268--------------------------------------------------- 269 270For all supported boards there are ready-to-use default 271configurations available; just type "make <board_name>_config". 272 273Example: For a TQM823L module type: 274 275 cd u-boot 276 make TQM823L_config 277 278For the Cogent platform, you need to specify the cpu type as well; 279e.g. "make cogent_mpc8xx_config". And also configure the cogent 280directory according to the instructions in cogent/README. 281 282 283Configuration Options: 284---------------------- 285 286Configuration depends on the combination of board and CPU type; all 287such information is kept in a configuration file 288"include/configs/<board_name>.h". 289 290Example: For a TQM823L module, all configuration settings are in 291"include/configs/TQM823L.h". 292 293 294Many of the options are named exactly as the corresponding Linux 295kernel configuration options. The intention is to make it easier to 296build a config tool - later. 297 298 299The following options need to be configured: 300 301- CPU Type: Define exactly one of 302 303 PowerPC based CPUs: 304 ------------------- 305 CONFIG_MPC823, CONFIG_MPC850, CONFIG_MPC855, CONFIG_MPC860 306 or CONFIG_MPC5xx 307 or CONFIG_MPC824X, CONFIG_MPC8260 308 or CONFIG_IOP480 309 or CONFIG_405GP 310 or CONFIG_405EP 311 or CONFIG_440 312 or CONFIG_MPC74xx 313 or CONFIG_750FX 314 315 ARM based CPUs: 316 --------------- 317 CONFIG_SA1110 318 CONFIG_ARM7 319 CONFIG_PXA250 320 321 322- Board Type: Define exactly one of 323 324 PowerPC based boards: 325 --------------------- 326 327 CONFIG_ADCIOP, CONFIG_ICU862 CONFIG_RPXsuper, 328 CONFIG_ADS860, CONFIG_IP860, CONFIG_SM850, 329 CONFIG_AMX860, CONFIG_IPHASE4539, CONFIG_SPD823TS, 330 CONFIG_AR405, CONFIG_IVML24, CONFIG_SXNI855T, 331 CONFIG_BAB7xx, CONFIG_IVML24_128, CONFIG_Sandpoint8240, 332 CONFIG_CANBT, CONFIG_IVML24_256, CONFIG_Sandpoint8245, 333 CONFIG_CCM, CONFIG_IVMS8, CONFIG_TQM823L, 334 CONFIG_CPCI405, CONFIG_IVMS8_128, CONFIG_TQM850L, 335 CONFIG_CPCI4052, CONFIG_IVMS8_256, CONFIG_TQM855L, 336 CONFIG_CPCIISER4, CONFIG_LANTEC, CONFIG_TQM860L, 337 CONFIG_CPU86, CONFIG_MBX, CONFIG_TQM8260, 338 CONFIG_CRAYL1, CONFIG_MBX860T, CONFIG_TTTech, 339 CONFIG_CU824, CONFIG_MHPC, CONFIG_UTX8245, 340 CONFIG_DASA_SIM, CONFIG_MIP405, CONFIG_W7OLMC, 341 CONFIG_DU405, CONFIG_MOUSSE, CONFIG_W7OLMG, 342 CONFIG_ELPPC, CONFIG_MPC8260ADS, CONFIG_WALNUT405, 343 CONFIG_ERIC, CONFIG_MUSENKI, CONFIG_ZUMA, 344 CONFIG_ESTEEM192E, CONFIG_MVS1, CONFIG_c2mon, 345 CONFIG_ETX094, CONFIG_NX823, CONFIG_cogent_mpc8260, 346 CONFIG_EVB64260, CONFIG_OCRTC, CONFIG_cogent_mpc8xx, 347 CONFIG_FADS823, CONFIG_ORSG, CONFIG_ep8260, 348 CONFIG_FADS850SAR, CONFIG_OXC, CONFIG_gw8260, 349 CONFIG_FADS860T, CONFIG_PCI405, CONFIG_hermes, 350 CONFIG_FLAGADM, CONFIG_PCIPPC2, CONFIG_hymod, 351 CONFIG_FPS850L, CONFIG_PCIPPC6, CONFIG_lwmon, 352 CONFIG_GEN860T, CONFIG_PIP405, CONFIG_pcu_e, 353 CONFIG_GENIETV, CONFIG_PM826, CONFIG_ppmc8260, 354 CONFIG_GTH, CONFIG_RPXClassic, CONFIG_rsdproto, 355 CONFIG_IAD210, CONFIG_RPXlite, CONFIG_sbc8260, 356 CONFIG_EBONY, CONFIG_sacsng, CONFIG_FPS860L, 357 CONFIG_V37, CONFIG_ELPT860, CONFIG_CMI, 358 CONFIG_NETVIA, CONFIG_RBC823 359 360 ARM based boards: 361 ----------------- 362 363 CONFIG_HHP_CRADLE, CONFIG_DNP1110, CONFIG_EP7312, 364 CONFIG_IMPA7, CONFIG_LART, CONFIG_LUBBOCK, 365 CONFIG_INNOVATOROMAP1510, CONFIG_INNOVATOROMAP1610 366 CONFIG_SHANNON, CONFIG_SMDK2400, CONFIG_SMDK2410, 367 CONFIG_TRAB, CONFIG_VCMA9, CONFIG_AT91RM9200DK 368 369 370- CPU Module Type: (if CONFIG_COGENT is defined) 371 Define exactly one of 372 CONFIG_CMA286_60_OLD 373--- FIXME --- not tested yet: 374 CONFIG_CMA286_60, CONFIG_CMA286_21, CONFIG_CMA286_60P, 375 CONFIG_CMA287_23, CONFIG_CMA287_50 376 377- Motherboard Type: (if CONFIG_COGENT is defined) 378 Define exactly one of 379 CONFIG_CMA101, CONFIG_CMA102 380 381- Motherboard I/O Modules: (if CONFIG_COGENT is defined) 382 Define one or more of 383 CONFIG_CMA302 384 385- Motherboard Options: (if CONFIG_CMA101 or CONFIG_CMA102 are defined) 386 Define one or more of 387 CONFIG_LCD_HEARTBEAT - update a character position on 388 the lcd display every second with 389 a "rotator" |\-/|\-/ 390 391- Board flavour: (if CONFIG_MPC8260ADS is defined) 392 CONFIG_ADSTYPE 393 Possible values are: 394 CFG_8260ADS - original MPC8260ADS 395 CFG_8266ADS - MPC8266ADS (untested) 396 CFG_PQ2FADS - PQ2FADS-ZU 397 398 399- MPC824X Family Member (if CONFIG_MPC824X is defined) 400 Define exactly one of 401 CONFIG_MPC8240, CONFIG_MPC8245 402 403- 8xx CPU Options: (if using an 8xx cpu) 404 Define one or more of 405 CONFIG_8xx_GCLK_FREQ - if get_gclk_freq() can not work e.g. 406 no 32KHz reference PIT/RTC clock 407 408- Clock Interface: 409 CONFIG_CLOCKS_IN_MHZ 410 411 U-Boot stores all clock information in Hz 412 internally. For binary compatibility with older Linux 413 kernels (which expect the clocks passed in the 414 bd_info data to be in MHz) the environment variable 415 "clocks_in_mhz" can be defined so that U-Boot 416 converts clock data to MHZ before passing it to the 417 Linux kernel. 418 419 When CONFIG_CLOCKS_IN_MHZ is defined, a definition of 420 "clocks_in_mhz=1" is automatically included in the 421 default environment. 422 423- Console Interface: 424 Depending on board, define exactly one serial port 425 (like CONFIG_8xx_CONS_SMC1, CONFIG_8xx_CONS_SMC2, 426 CONFIG_8xx_CONS_SCC1, ...), or switch off the serial 427 console by defining CONFIG_8xx_CONS_NONE 428 429 Note: if CONFIG_8xx_CONS_NONE is defined, the serial 430 port routines must be defined elsewhere 431 (i.e. serial_init(), serial_getc(), ...) 432 433 CONFIG_CFB_CONSOLE 434 Enables console device for a color framebuffer. Needs following 435 defines (cf. smiLynxEM, i8042, board/eltec/bab7xx) 436 VIDEO_FB_LITTLE_ENDIAN graphic memory organisation 437 (default big endian) 438 VIDEO_HW_RECTFILL graphic chip supports 439 rectangle fill 440 (cf. smiLynxEM) 441 VIDEO_HW_BITBLT graphic chip supports 442 bit-blit (cf. smiLynxEM) 443 VIDEO_VISIBLE_COLS visible pixel columns 444 (cols=pitch) 445 VIDEO_VISIBLE_ROWS visible pixel rows 446 VIDEO_PIXEL_SIZE bytes per pixel 447 VIDEO_DATA_FORMAT graphic data format 448 (0-5, cf. cfb_console.c) 449 VIDEO_FB_ADRS framebuffer address 450 VIDEO_KBD_INIT_FCT keyboard int fct 451 (i.e. i8042_kbd_init()) 452 VIDEO_TSTC_FCT test char fct 453 (i.e. i8042_tstc) 454 VIDEO_GETC_FCT get char fct 455 (i.e. i8042_getc) 456 CONFIG_CONSOLE_CURSOR cursor drawing on/off 457 (requires blink timer 458 cf. i8042.c) 459 CFG_CONSOLE_BLINK_COUNT blink interval (cf. i8042.c) 460 CONFIG_CONSOLE_TIME display time/date info in 461 upper right corner 462 (requires CFG_CMD_DATE) 463 CONFIG_VIDEO_LOGO display Linux logo in 464 upper left corner 465 CONFIG_VIDEO_BMP_LOGO use bmp_logo.h instead of 466 linux_logo.h for logo. 467 Requires CONFIG_VIDEO_LOGO 468 CONFIG_CONSOLE_EXTRA_INFO 469 addional board info beside 470 the logo 471 472 When CONFIG_CFB_CONSOLE is defined, video console is 473 default i/o. Serial console can be forced with 474 environment 'console=serial'. 475 476- Console Baudrate: 477 CONFIG_BAUDRATE - in bps 478 Select one of the baudrates listed in 479 CFG_BAUDRATE_TABLE, see below. 480 481- Interrupt driven serial port input: 482 CONFIG_SERIAL_SOFTWARE_FIFO 483 484 PPC405GP only. 485 Use an interrupt handler for receiving data on the 486 serial port. It also enables using hardware handshake 487 (RTS/CTS) and UART's built-in FIFO. Set the number of 488 bytes the interrupt driven input buffer should have. 489 490 Set to 0 to disable this feature (this is the default). 491 This will also disable hardware handshake. 492 493- Console UART Number: 494 CONFIG_UART1_CONSOLE 495 496 IBM PPC4xx only. 497 If defined internal UART1 (and not UART0) is used 498 as default U-Boot console. 499 500- Boot Delay: CONFIG_BOOTDELAY - in seconds 501 Delay before automatically booting the default image; 502 set to -1 to disable autoboot. 503 504 See doc/README.autoboot for these options that 505 work with CONFIG_BOOTDELAY. None are required. 506 CONFIG_BOOT_RETRY_TIME 507 CONFIG_BOOT_RETRY_MIN 508 CONFIG_AUTOBOOT_KEYED 509 CONFIG_AUTOBOOT_PROMPT 510 CONFIG_AUTOBOOT_DELAY_STR 511 CONFIG_AUTOBOOT_STOP_STR 512 CONFIG_AUTOBOOT_DELAY_STR2 513 CONFIG_AUTOBOOT_STOP_STR2 514 CONFIG_ZERO_BOOTDELAY_CHECK 515 CONFIG_RESET_TO_RETRY 516 517- Autoboot Command: 518 CONFIG_BOOTCOMMAND 519 Only needed when CONFIG_BOOTDELAY is enabled; 520 define a command string that is automatically executed 521 when no character is read on the console interface 522 within "Boot Delay" after reset. 523 524 CONFIG_BOOTARGS 525 This can be used to pass arguments to the bootm 526 command. The value of CONFIG_BOOTARGS goes into the 527 environment value "bootargs". 528 529 CONFIG_RAMBOOT and CONFIG_NFSBOOT 530 The value of these goes into the environment as 531 "ramboot" and "nfsboot" respectively, and can be used 532 as a convenience, when switching between booting from 533 ram and nfs. 534 535- Pre-Boot Commands: 536 CONFIG_PREBOOT 537 538 When this option is #defined, the existence of the 539 environment variable "preboot" will be checked 540 immediately before starting the CONFIG_BOOTDELAY 541 countdown and/or running the auto-boot command resp. 542 entering interactive mode. 543 544 This feature is especially useful when "preboot" is 545 automatically generated or modified. For an example 546 see the LWMON board specific code: here "preboot" is 547 modified when the user holds down a certain 548 combination of keys on the (special) keyboard when 549 booting the systems 550 551- Serial Download Echo Mode: 552 CONFIG_LOADS_ECHO 553 If defined to 1, all characters received during a 554 serial download (using the "loads" command) are 555 echoed back. This might be needed by some terminal 556 emulations (like "cu"), but may as well just take 557 time on others. This setting #define's the initial 558 value of the "loads_echo" environment variable. 559 560- Kgdb Serial Baudrate: (if CFG_CMD_KGDB is defined) 561 CONFIG_KGDB_BAUDRATE 562 Select one of the baudrates listed in 563 CFG_BAUDRATE_TABLE, see below. 564 565- Monitor Functions: 566 CONFIG_COMMANDS 567 Most monitor functions can be selected (or 568 de-selected) by adjusting the definition of 569 CONFIG_COMMANDS; to select individual functions, 570 #define CONFIG_COMMANDS by "OR"ing any of the 571 following values: 572 573 #define enables commands: 574 ------------------------- 575 CFG_CMD_ASKENV * ask for env variable 576 CFG_CMD_AUTOSCRIPT Autoscript Support 577 CFG_CMD_BDI bdinfo 578 CFG_CMD_BEDBUG Include BedBug Debugger 579 CFG_CMD_BMP * BMP support 580 CFG_CMD_BOOTD bootd 581 CFG_CMD_CACHE icache, dcache 582 CFG_CMD_CONSOLE coninfo 583 CFG_CMD_DATE * support for RTC, date/time... 584 CFG_CMD_DHCP DHCP support 585 CFG_CMD_DIAG * Diagnostics 586 CFG_CMD_DOC * Disk-On-Chip Support 587 CFG_CMD_DTT Digital Therm and Thermostat 588 CFG_CMD_ECHO * echo arguments 589 CFG_CMD_EEPROM * EEPROM read/write support 590 CFG_CMD_ELF bootelf, bootvx 591 CFG_CMD_ENV saveenv 592 CFG_CMD_FDC * Floppy Disk Support 593 CFG_CMD_FAT FAT partition support 594 CFG_CMD_FDOS * Dos diskette Support 595 CFG_CMD_FLASH flinfo, erase, protect 596 CFG_CMD_FPGA FPGA device initialization support 597 CFG_CMD_HWFLOW * RTS/CTS hw flow control 598 CFG_CMD_I2C * I2C serial bus support 599 CFG_CMD_IDE * IDE harddisk support 600 CFG_CMD_IMI iminfo 601 CFG_CMD_IMLS List all found images 602 CFG_CMD_IMMAP * IMMR dump support 603 CFG_CMD_IRQ * irqinfo 604 CFG_CMD_JFFS2 * JFFS2 Support 605 CFG_CMD_KGDB * kgdb 606 CFG_CMD_LOADB loadb 607 CFG_CMD_LOADS loads 608 CFG_CMD_MEMORY md, mm, nm, mw, cp, cmp, crc, base, 609 loop, mtest 610 CFG_CMD_MISC Misc functions like sleep etc 611 CFG_CMD_MMC MMC memory mapped support 612 CFG_CMD_MII MII utility commands 613 CFG_CMD_NAND * NAND support 614 CFG_CMD_NET bootp, tftpboot, rarpboot 615 CFG_CMD_PCI * pciinfo 616 CFG_CMD_PCMCIA * PCMCIA support 617 CFG_CMD_PING * send ICMP ECHO_REQUEST to network host 618 CFG_CMD_PORTIO Port I/O 619 CFG_CMD_REGINFO * Register dump 620 CFG_CMD_RUN run command in env variable 621 CFG_CMD_SAVES save S record dump 622 CFG_CMD_SCSI * SCSI Support 623 CFG_CMD_SDRAM * print SDRAM configuration information 624 CFG_CMD_SETGETDCR Support for DCR Register access (4xx only) 625 CFG_CMD_SPI * SPI serial bus support 626 CFG_CMD_USB * USB support 627 CFG_CMD_VFD * VFD support (TRAB) 628 CFG_CMD_BSP * Board SPecific functions 629 ----------------------------------------------- 630 CFG_CMD_ALL all 631 632 CFG_CMD_DFL Default configuration; at the moment 633 this is includes all commands, except 634 the ones marked with "*" in the list 635 above. 636 637 If you don't define CONFIG_COMMANDS it defaults to 638 CFG_CMD_DFL in include/cmd_confdefs.h. A board can 639 override the default settings in the respective 640 include file. 641 642 EXAMPLE: If you want all functions except of network 643 support you can write: 644 645 #define CONFIG_COMMANDS (CFG_CMD_ALL & ~CFG_CMD_NET) 646 647 648 Note: Don't enable the "icache" and "dcache" commands 649 (configuration option CFG_CMD_CACHE) unless you know 650 what you (and your U-Boot users) are doing. Data 651 cache cannot be enabled on systems like the 8xx or 652 8260 (where accesses to the IMMR region must be 653 uncached), and it cannot be disabled on all other 654 systems where we (mis-) use the data cache to hold an 655 initial stack and some data. 656 657 658 XXX - this list needs to get updated! 659 660- Watchdog: 661 CONFIG_WATCHDOG 662 If this variable is defined, it enables watchdog 663 support. There must be support in the platform specific 664 code for a watchdog. For the 8xx and 8260 CPUs, the 665 SIU Watchdog feature is enabled in the SYPCR 666 register. 667 668- U-Boot Version: 669 CONFIG_VERSION_VARIABLE 670 If this variable is defined, an environment variable 671 named "ver" is created by U-Boot showing the U-Boot 672 version as printed by the "version" command. 673 This variable is readonly. 674 675- Real-Time Clock: 676 677 When CFG_CMD_DATE is selected, the type of the RTC 678 has to be selected, too. Define exactly one of the 679 following options: 680 681 CONFIG_RTC_MPC8xx - use internal RTC of MPC8xx 682 CONFIG_RTC_PCF8563 - use Philips PCF8563 RTC 683 CONFIG_RTC_MC146818 - use MC146818 RTC 684 CONFIG_RTC_DS1307 - use Maxim, Inc. DS1307 RTC 685 CONFIG_RTC_DS1337 - use Maxim, Inc. DS1337 RTC 686 CONFIG_RTC_DS1338 - use Maxim, Inc. DS1338 RTC 687 CONFIG_RTC_DS164x - use Dallas DS164x RTC 688 689 Note that if the RTC uses I2C, then the I2C interface 690 must also be configured. See I2C Support, below. 691 692- Timestamp Support: 693 694 When CONFIG_TIMESTAMP is selected, the timestamp 695 (date and time) of an image is printed by image 696 commands like bootm or iminfo. This option is 697 automatically enabled when you select CFG_CMD_DATE . 698 699- Partition Support: 700 CONFIG_MAC_PARTITION and/or CONFIG_DOS_PARTITION 701 and/or CONFIG_ISO_PARTITION 702 703 If IDE or SCSI support is enabled (CFG_CMD_IDE or 704 CFG_CMD_SCSI) you must configure support for at least 705 one partition type as well. 706 707- IDE Reset method: 708 CONFIG_IDE_RESET_ROUTINE 709 710 Set this to define that instead of a reset Pin, the 711 routine ide_set_reset(int idereset) will be used. 712 713- ATAPI Support: 714 CONFIG_ATAPI 715 716 Set this to enable ATAPI support. 717 718- SCSI Support: 719 At the moment only there is only support for the 720 SYM53C8XX SCSI controller; define 721 CONFIG_SCSI_SYM53C8XX to enable it. 722 723 CFG_SCSI_MAX_LUN [8], CFG_SCSI_MAX_SCSI_ID [7] and 724 CFG_SCSI_MAX_DEVICE [CFG_SCSI_MAX_SCSI_ID * 725 CFG_SCSI_MAX_LUN] can be adjusted to define the 726 maximum numbers of LUNs, SCSI ID's and target 727 devices. 728 CFG_SCSI_SYM53C8XX_CCF to fix clock timing (80Mhz) 729 730- NETWORK Support (PCI): 731 CONFIG_E1000 732 Support for Intel 8254x gigabit chips. 733 734 CONFIG_EEPRO100 735 Support for Intel 82557/82559/82559ER chips. 736 Optional CONFIG_EEPRO100_SROM_WRITE enables eeprom 737 write routine for first time initialisation. 738 739 CONFIG_TULIP 740 Support for Digital 2114x chips. 741 Optional CONFIG_TULIP_SELECT_MEDIA for board specific 742 modem chip initialisation (KS8761/QS6611). 743 744 CONFIG_NATSEMI 745 Support for National dp83815 chips. 746 747 CONFIG_NS8382X 748 Support for National dp8382[01] gigabit chips. 749 750- NETWORK Support (other): 751 752 CONFIG_DRIVER_LAN91C96 753 Support for SMSC's LAN91C96 chips. 754 755 CONFIG_LAN91C96_BASE 756 Define this to hold the physical address 757 of the LAN91C96's I/O space 758 759 CONFIG_LAN91C96_USE_32_BIT 760 Define this to enable 32 bit addressing 761 762- USB Support: 763 At the moment only the UHCI host controller is 764 supported (PIP405, MIP405); define 765 CONFIG_USB_UHCI to enable it. 766 define CONFIG_USB_KEYBOARD to enable the USB Keyboard 767 end define CONFIG_USB_STORAGE to enable the USB 768 storage devices. 769 Note: 770 Supported are USB Keyboards and USB Floppy drives 771 (TEAC FD-05PUB). 772 773- MMC Support: 774 The MMC controller on the Intel PXA is supported. To 775 enable this define CONFIG_MMC. The MMC can be 776 accessed from the boot prompt by mapping the device 777 to physical memory similar to flash. Command line is 778 enabled with CFG_CMD_MMC. The MMC driver also works with 779 the FAT fs. This is enabled with CFG_CMD_FAT. 780 781- Keyboard Support: 782 CONFIG_ISA_KEYBOARD 783 784 Define this to enable standard (PC-Style) keyboard 785 support 786 787 CONFIG_I8042_KBD 788 Standard PC keyboard driver with US (is default) and 789 GERMAN key layout (switch via environment 'keymap=de') support. 790 Export function i8042_kbd_init, i8042_tstc and i8042_getc 791 for cfb_console. Supports cursor blinking. 792 793- Video support: 794 CONFIG_VIDEO 795 796 Define this to enable video support (for output to 797 video). 798 799 CONFIG_VIDEO_CT69000 800 801 Enable Chips & Technologies 69000 Video chip 802 803 CONFIG_VIDEO_SMI_LYNXEM 804 Enable Silicon Motion SMI 712/710/810 Video chip 805 Videomode are selected via environment 'videomode' with 806 standard LiLo mode numbers. 807 Following modes are supported (* is default): 808 809 800x600 1024x768 1280x1024 810 256 (8bit) 303* 305 307 811 65536 (16bit) 314 317 31a 812 16,7 Mill (24bit) 315 318 31b 813 (i.e. setenv videomode 317; saveenv; reset;) 814 815 CONFIG_VIDEO_SED13806 816 Enable Epson SED13806 driver. This driver supports 8bpp 817 and 16bpp modes defined by CONFIG_VIDEO_SED13806_8BPP 818 or CONFIG_VIDEO_SED13806_16BPP 819 820- Keyboard Support: 821 CONFIG_KEYBOARD 822 823 Define this to enable a custom keyboard support. 824 This simply calls drv_keyboard_init() which must be 825 defined in your board-specific files. 826 The only board using this so far is RBC823. 827 828- LCD Support: CONFIG_LCD 829 830 Define this to enable LCD support (for output to LCD 831 display); also select one of the supported displays 832 by defining one of these: 833 834 CONFIG_NEC_NL6648AC33: 835 836 NEC NL6648AC33-18. Active, color, single scan. 837 838 CONFIG_NEC_NL6648BC20 839 840 NEC NL6648BC20-08. 6.5", 640x480. 841 Active, color, single scan. 842 843 CONFIG_SHARP_16x9 844 845 Sharp 320x240. Active, color, single scan. 846 It isn't 16x9, and I am not sure what it is. 847 848 CONFIG_SHARP_LQ64D341 849 850 Sharp LQ64D341 display, 640x480. 851 Active, color, single scan. 852 853 CONFIG_HLD1045 854 855 HLD1045 display, 640x480. 856 Active, color, single scan. 857 858 CONFIG_OPTREX_BW 859 860 Optrex CBL50840-2 NF-FW 99 22 M5 861 or 862 Hitachi LMG6912RPFC-00T 863 or 864 Hitachi SP14Q002 865 866 320x240. Black & white. 867 868 Normally display is black on white background; define 869 CFG_WHITE_ON_BLACK to get it inverted. 870 871- Splash Screen Support: CONFIG_SPLASH_SCREEN 872 873 If this option is set, the environment is checked for 874 a variable "splashimage". If found, the usual display 875 of logo, copyright and system information on the LCD 876 is supressed and the BMP image at the address 877 specified in "splashimage" is loaded instead. The 878 console is redirected to the "nulldev", too. This 879 allows for a "silent" boot where a splash screen is 880 loaded very quickly after power-on. 881 882- Compression support: 883 CONFIG_BZIP2 884 885 If this option is set, support for bzip2 compressed 886 images is included. If not, only uncompressed and gzip 887 compressed images are supported. 888 889 NOTE: the bzip2 algorithm requires a lot of RAM, so 890 the malloc area (as defined by CFG_MALLOC_LEN) should 891 be at least 4MB. 892 893- Ethernet address: 894 CONFIG_ETHADDR 895 CONFIG_ETH2ADDR 896 CONFIG_ETH3ADDR 897 898 Define a default value for ethernet address to use 899 for the respective ethernet interface, in case this 900 is not determined automatically. 901 902- IP address: 903 CONFIG_IPADDR 904 905 Define a default value for the IP address to use for 906 the default ethernet interface, in case this is not 907 determined through e.g. bootp. 908 909- Server IP address: 910 CONFIG_SERVERIP 911 912 Defines a default value for theIP address of a TFTP 913 server to contact when using the "tftboot" command. 914 915- BOOTP Recovery Mode: 916 CONFIG_BOOTP_RANDOM_DELAY 917 918 If you have many targets in a network that try to 919 boot using BOOTP, you may want to avoid that all 920 systems send out BOOTP requests at precisely the same 921 moment (which would happen for instance at recovery 922 from a power failure, when all systems will try to 923 boot, thus flooding the BOOTP server. Defining 924 CONFIG_BOOTP_RANDOM_DELAY causes a random delay to be 925 inserted before sending out BOOTP requests. The 926 following delays are insterted then: 927 928 1st BOOTP request: delay 0 ... 1 sec 929 2nd BOOTP request: delay 0 ... 2 sec 930 3rd BOOTP request: delay 0 ... 4 sec 931 4th and following 932 BOOTP requests: delay 0 ... 8 sec 933 934- DHCP Advanced Options: 935 CONFIG_BOOTP_MASK 936 937 You can fine tune the DHCP functionality by adding 938 these flags to the CONFIG_BOOTP_MASK define: 939 940 CONFIG_BOOTP_DNS2 - If a DHCP client requests the DNS 941 serverip from a DHCP server, it is possible that more 942 than one DNS serverip is offered to the client. 943 If CONFIG_BOOTP_DNS2 is enabled, the secondary DNS 944 serverip will be stored in the additional environment 945 variable "dnsip2". The first DNS serverip is always 946 stored in the variable "dnsip", when CONFIG_BOOTP_DNS 947 is added to the CONFIG_BOOTP_MASK. 948 949 CONFIG_BOOTP_SEND_HOSTNAME - Some DHCP servers are capable 950 to do a dynamic update of a DNS server. To do this, they 951 need the hostname of the DHCP requester. 952 If CONFIG_BOOP_SEND_HOSTNAME is added to the 953 CONFIG_BOOTP_MASK, the content of the "hostname" 954 environment variable is passed as option 12 to 955 the DHCP server. 956 957- Status LED: CONFIG_STATUS_LED 958 959 Several configurations allow to display the current 960 status using a LED. For instance, the LED will blink 961 fast while running U-Boot code, stop blinking as 962 soon as a reply to a BOOTP request was received, and 963 start blinking slow once the Linux kernel is running 964 (supported by a status LED driver in the Linux 965 kernel). Defining CONFIG_STATUS_LED enables this 966 feature in U-Boot. 967 968- CAN Support: CONFIG_CAN_DRIVER 969 970 Defining CONFIG_CAN_DRIVER enables CAN driver support 971 on those systems that support this (optional) 972 feature, like the TQM8xxL modules. 973 974- I2C Support: CONFIG_HARD_I2C | CONFIG_SOFT_I2C 975 976 These enable I2C serial bus commands. Defining either of 977 (but not both of) CONFIG_HARD_I2C or CONFIG_SOFT_I2C will 978 include the appropriate I2C driver for the selected cpu. 979 980 This will allow you to use i2c commands at the u-boot 981 command line (as long as you set CFG_CMD_I2C in 982 CONFIG_COMMANDS) and communicate with i2c based realtime 983 clock chips. See common/cmd_i2c.c for a description of the 984 command line interface. 985 986 CONFIG_HARD_I2C selects the CPM hardware driver for I2C. 987 988 CONFIG_SOFT_I2C configures u-boot to use a software (aka 989 bit-banging) driver instead of CPM or similar hardware 990 support for I2C. 991 992 There are several other quantities that must also be 993 defined when you define CONFIG_HARD_I2C or CONFIG_SOFT_I2C. 994 995 In both cases you will need to define CFG_I2C_SPEED 996 to be the frequency (in Hz) at which you wish your i2c bus 997 to run and CFG_I2C_SLAVE to be the address of this node (ie 998 the cpu's i2c node address). 999 1000 Now, the u-boot i2c code for the mpc8xx (cpu/mpc8xx/i2c.c) 1001 sets the cpu up as a master node and so its address should 1002 therefore be cleared to 0 (See, eg, MPC823e User's Manual 1003 p.16-473). So, set CFG_I2C_SLAVE to 0. 1004 1005 That's all that's required for CONFIG_HARD_I2C. 1006 1007 If you use the software i2c interface (CONFIG_SOFT_I2C) 1008 then the following macros need to be defined (examples are 1009 from include/configs/lwmon.h): 1010 1011 I2C_INIT 1012 1013 (Optional). Any commands necessary to enable the I2C 1014 controller or configure ports. 1015 1016 eg: #define I2C_INIT (immr->im_cpm.cp_pbdir |= PB_SCL) 1017 1018 I2C_PORT 1019 1020 (Only for MPC8260 CPU). The I/O port to use (the code 1021 assumes both bits are on the same port). Valid values 1022 are 0..3 for ports A..D. 1023 1024 I2C_ACTIVE 1025 1026 The code necessary to make the I2C data line active 1027 (driven). If the data line is open collector, this 1028 define can be null. 1029 1030 eg: #define I2C_ACTIVE (immr->im_cpm.cp_pbdir |= PB_SDA) 1031 1032 I2C_TRISTATE 1033 1034 The code necessary to make the I2C data line tri-stated 1035 (inactive). If the data line is open collector, this 1036 define can be null. 1037 1038 eg: #define I2C_TRISTATE (immr->im_cpm.cp_pbdir &= ~PB_SDA) 1039 1040 I2C_READ 1041 1042 Code that returns TRUE if the I2C data line is high, 1043 FALSE if it is low. 1044 1045 eg: #define I2C_READ ((immr->im_cpm.cp_pbdat & PB_SDA) != 0) 1046 1047 I2C_SDA(bit) 1048 1049 If <bit> is TRUE, sets the I2C data line high. If it 1050 is FALSE, it clears it (low). 1051 1052 eg: #define I2C_SDA(bit) \ 1053 if(bit) immr->im_cpm.cp_pbdat |= PB_SDA; \ 1054 else immr->im_cpm.cp_pbdat &= ~PB_SDA 1055 1056 I2C_SCL(bit) 1057 1058 If <bit> is TRUE, sets the I2C clock line high. If it 1059 is FALSE, it clears it (low). 1060 1061 eg: #define I2C_SCL(bit) \ 1062 if(bit) immr->im_cpm.cp_pbdat |= PB_SCL; \ 1063 else immr->im_cpm.cp_pbdat &= ~PB_SCL 1064 1065 I2C_DELAY 1066 1067 This delay is invoked four times per clock cycle so this 1068 controls the rate of data transfer. The data rate thus 1069 is 1 / (I2C_DELAY * 4). Often defined to be something 1070 like: 1071 1072 #define I2C_DELAY udelay(2) 1073 1074 CFG_I2C_INIT_BOARD 1075 1076 When a board is reset during an i2c bus transfer 1077 chips might think that the current transfer is still 1078 in progress. On some boards it is possible to access 1079 the i2c SCLK line directly, either by using the 1080 processor pin as a GPIO or by having a second pin 1081 connected to the bus. If this option is defined a 1082 custom i2c_init_board() routine in boards/xxx/board.c 1083 is run early in the boot sequence. 1084 1085- SPI Support: CONFIG_SPI 1086 1087 Enables SPI driver (so far only tested with 1088 SPI EEPROM, also an instance works with Crystal A/D and 1089 D/As on the SACSng board) 1090 1091 CONFIG_SPI_X 1092 1093 Enables extended (16-bit) SPI EEPROM addressing. 1094 (symmetrical to CONFIG_I2C_X) 1095 1096 CONFIG_SOFT_SPI 1097 1098 Enables a software (bit-bang) SPI driver rather than 1099 using hardware support. This is a general purpose 1100 driver that only requires three general I/O port pins 1101 (two outputs, one input) to function. If this is 1102 defined, the board configuration must define several 1103 SPI configuration items (port pins to use, etc). For 1104 an example, see include/configs/sacsng.h. 1105 1106- FPGA Support: CONFIG_FPGA_COUNT 1107 1108 Specify the number of FPGA devices to support. 1109 1110 CONFIG_FPGA 1111 1112 Used to specify the types of FPGA devices. For 1113 example, 1114 #define CONFIG_FPGA CFG_XILINX_VIRTEX2 1115 1116 CFG_FPGA_PROG_FEEDBACK 1117 1118 Enable printing of hash marks during FPGA 1119 configuration. 1120 1121 CFG_FPGA_CHECK_BUSY 1122 1123 Enable checks on FPGA configuration interface busy 1124 status by the configuration function. This option 1125 will require a board or device specific function to 1126 be written. 1127 1128 CONFIG_FPGA_DELAY 1129 1130 If defined, a function that provides delays in the 1131 FPGA configuration driver. 1132 1133 CFG_FPGA_CHECK_CTRLC 1134 1135 Allow Control-C to interrupt FPGA configuration 1136 1137 CFG_FPGA_CHECK_ERROR 1138 1139 Check for configuration errors during FPGA bitfile 1140 loading. For example, abort during Virtex II 1141 configuration if the INIT_B line goes low (which 1142 indicated a CRC error). 1143 1144 CFG_FPGA_WAIT_INIT 1145 1146 Maximum time to wait for the INIT_B line to deassert 1147 after PROB_B has been deasserted during a Virtex II 1148 FPGA configuration sequence. The default time is 500 mS. 1149 1150 CFG_FPGA_WAIT_BUSY 1151 1152 Maximum time to wait for BUSY to deassert during 1153 Virtex II FPGA configuration. The default is 5 mS. 1154 1155 CFG_FPGA_WAIT_CONFIG 1156 1157 Time to wait after FPGA configuration. The default is 1158 200 mS. 1159 1160- FPGA Support: CONFIG_FPGA_COUNT 1161 1162 Specify the number of FPGA devices to support. 1163 1164 CONFIG_FPGA 1165 1166 Used to specify the types of FPGA devices. For example, 1167 #define CONFIG_FPGA CFG_XILINX_VIRTEX2 1168 1169 CFG_FPGA_PROG_FEEDBACK 1170 1171 Enable printing of hash marks during FPGA configuration. 1172 1173 CFG_FPGA_CHECK_BUSY 1174 1175 Enable checks on FPGA configuration interface busy 1176 status by the configuration function. This option 1177 will require a board or device specific function to 1178 be written. 1179 1180 CONFIG_FPGA_DELAY 1181 1182 If defined, a function that provides delays in the FPGA 1183 configuration driver. 1184 1185 CFG_FPGA_CHECK_CTRLC 1186 Allow Control-C to interrupt FPGA configuration 1187 1188 CFG_FPGA_CHECK_ERROR 1189 1190 Check for configuration errors during FPGA bitfile 1191 loading. For example, abort during Virtex II 1192 configuration if the INIT_B line goes low (which 1193 indicated a CRC error). 1194 1195 CFG_FPGA_WAIT_INIT 1196 1197 Maximum time to wait for the INIT_B line to deassert 1198 after PROB_B has been deasserted during a Virtex II 1199 FPGA configuration sequence. The default time is 500 1200 mS. 1201 1202 CFG_FPGA_WAIT_BUSY 1203 1204 Maximum time to wait for BUSY to deassert during 1205 Virtex II FPGA configuration. The default is 5 mS. 1206 1207 CFG_FPGA_WAIT_CONFIG 1208 1209 Time to wait after FPGA configuration. The default is 1210 200 mS. 1211 1212- Configuration Management: 1213 CONFIG_IDENT_STRING 1214 1215 If defined, this string will be added to the U-Boot 1216 version information (U_BOOT_VERSION) 1217 1218- Vendor Parameter Protection: 1219 1220 U-Boot considers the values of the environment 1221 variables "serial#" (Board Serial Number) and 1222 "ethaddr" (Ethernet Address) to be parameters that 1223 are set once by the board vendor / manufacturer, and 1224 protects these variables from casual modification by 1225 the user. Once set, these variables are read-only, 1226 and write or delete attempts are rejected. You can 1227 change this behviour: 1228 1229 If CONFIG_ENV_OVERWRITE is #defined in your config 1230 file, the write protection for vendor parameters is 1231 completely disabled. Anybody can change or delete 1232 these parameters. 1233 1234 Alternatively, if you #define _both_ CONFIG_ETHADDR 1235 _and_ CONFIG_OVERWRITE_ETHADDR_ONCE, a default 1236 ethernet address is installed in the environment, 1237 which can be changed exactly ONCE by the user. [The 1238 serial# is unaffected by this, i. e. it remains 1239 read-only.] 1240 1241- Protected RAM: 1242 CONFIG_PRAM 1243 1244 Define this variable to enable the reservation of 1245 "protected RAM", i. e. RAM which is not overwritten 1246 by U-Boot. Define CONFIG_PRAM to hold the number of 1247 kB you want to reserve for pRAM. You can overwrite 1248 this default value by defining an environment 1249 variable "pram" to the number of kB you want to 1250 reserve. Note that the board info structure will 1251 still show the full amount of RAM. If pRAM is 1252 reserved, a new environment variable "mem" will 1253 automatically be defined to hold the amount of 1254 remaining RAM in a form that can be passed as boot 1255 argument to Linux, for instance like that: 1256 1257 setenv bootargs ... mem=\$(mem) 1258 saveenv 1259 1260 This way you can tell Linux not to use this memory, 1261 either, which results in a memory region that will 1262 not be affected by reboots. 1263 1264 *WARNING* If your board configuration uses automatic 1265 detection of the RAM size, you must make sure that 1266 this memory test is non-destructive. So far, the 1267 following board configurations are known to be 1268 "pRAM-clean": 1269 1270 ETX094, IVMS8, IVML24, SPD8xx, TQM8xxL, 1271 HERMES, IP860, RPXlite, LWMON, LANTEC, 1272 PCU_E, FLAGADM, TQM8260 1273 1274- Error Recovery: 1275 CONFIG_PANIC_HANG 1276 1277 Define this variable to stop the system in case of a 1278 fatal error, so that you have to reset it manually. 1279 This is probably NOT a good idea for an embedded 1280 system where you want to system to reboot 1281 automatically as fast as possible, but it may be 1282 useful during development since you can try to debug 1283 the conditions that lead to the situation. 1284 1285 CONFIG_NET_RETRY_COUNT 1286 1287 This variable defines the number of retries for 1288 network operations like ARP, RARP, TFTP, or BOOTP 1289 before giving up the operation. If not defined, a 1290 default value of 5 is used. 1291 1292- Command Interpreter: 1293 CFG_HUSH_PARSER 1294 1295 Define this variable to enable the "hush" shell (from 1296 Busybox) as command line interpreter, thus enabling 1297 powerful command line syntax like 1298 if...then...else...fi conditionals or `&&' and '||' 1299 constructs ("shell scripts"). 1300 1301 If undefined, you get the old, much simpler behaviour 1302 with a somewhat smaller memory footprint. 1303 1304 1305 CFG_PROMPT_HUSH_PS2 1306 1307 This defines the secondary prompt string, which is 1308 printed when the command interpreter needs more input 1309 to complete a command. Usually "> ". 1310 1311 Note: 1312 1313 In the current implementation, the local variables 1314 space and global environment variables space are 1315 separated. Local variables are those you define by 1316 simply typing `name=value'. To access a local 1317 variable later on, you have write `$name' or 1318 `${name}'; to execute the contents of a variable 1319 directly type `$name' at the command prompt. 1320 1321 Global environment variables are those you use 1322 setenv/printenv to work with. To run a command stored 1323 in such a variable, you need to use the run command, 1324 and you must not use the '$' sign to access them. 1325 1326 To store commands and special characters in a 1327 variable, please use double quotation marks 1328 surrounding the whole text of the variable, instead 1329 of the backslashes before semicolons and special 1330 symbols. 1331 1332- Default Environment 1333 CONFIG_EXTRA_ENV_SETTINGS 1334 1335 Define this to contain any number of null terminated 1336 strings (variable = value pairs) that will be part of 1337 the default environment compiled into the boot image. 1338 1339 For example, place something like this in your 1340 board's config file: 1341 1342 #define CONFIG_EXTRA_ENV_SETTINGS \ 1343 "myvar1=value1\0" \ 1344 "myvar2=value2\0" 1345 1346 Warning: This method is based on knowledge about the 1347 internal format how the environment is stored by the 1348 U-Boot code. This is NOT an official, exported 1349 interface! Although it is unlikely that this format 1350 will change soon, there is no guarantee either. 1351 You better know what you are doing here. 1352 1353 Note: overly (ab)use of the default environment is 1354 discouraged. Make sure to check other ways to preset 1355 the environment like the autoscript function or the 1356 boot command first. 1357 1358- DataFlash Support 1359 CONFIG_HAS_DATAFLASH 1360 1361 Defining this option enables DataFlash features and 1362 allows to read/write in Dataflash via the standard 1363 commands cp, md... 1364 1365- Show boot progress 1366 CONFIG_SHOW_BOOT_PROGRESS 1367 1368 Defining this option allows to add some board- 1369 specific code (calling a user-provided function 1370 "show_boot_progress(int)") that enables you to show 1371 the system's boot progress on some display (for 1372 example, some LED's) on your board. At the moment, 1373 the following checkpoints are implemented: 1374 1375 Arg Where When 1376 1 common/cmd_bootm.c before attempting to boot an image 1377 -1 common/cmd_bootm.c Image header has bad magic number 1378 2 common/cmd_bootm.c Image header has correct magic number 1379 -2 common/cmd_bootm.c Image header has bad checksum 1380 3 common/cmd_bootm.c Image header has correct checksum 1381 -3 common/cmd_bootm.c Image data has bad checksum 1382 4 common/cmd_bootm.c Image data has correct checksum 1383 -4 common/cmd_bootm.c Image is for unsupported architecture 1384 5 common/cmd_bootm.c Architecture check OK 1385 -5 common/cmd_bootm.c Wrong Image Type (not kernel, multi, standalone) 1386 6 common/cmd_bootm.c Image Type check OK 1387 -6 common/cmd_bootm.c gunzip uncompression error 1388 -7 common/cmd_bootm.c Unimplemented compression type 1389 7 common/cmd_bootm.c Uncompression OK 1390 -8 common/cmd_bootm.c Wrong Image Type (not kernel, multi, standalone) 1391 8 common/cmd_bootm.c Image Type check OK 1392 -9 common/cmd_bootm.c Unsupported OS (not Linux, BSD, VxWorks, QNX) 1393 9 common/cmd_bootm.c Start initial ramdisk verification 1394 -10 common/cmd_bootm.c Ramdisk header has bad magic number 1395 -11 common/cmd_bootm.c Ramdisk header has bad checksum 1396 10 common/cmd_bootm.c Ramdisk header is OK 1397 -12 common/cmd_bootm.c Ramdisk data has bad checksum 1398 11 common/cmd_bootm.c Ramdisk data has correct checksum 1399 12 common/cmd_bootm.c Ramdisk verification complete, start loading 1400 -13 common/cmd_bootm.c Wrong Image Type (not PPC Linux Ramdisk) 1401 13 common/cmd_bootm.c Start multifile image verification 1402 14 common/cmd_bootm.c No initial ramdisk, no multifile, continue. 1403 15 common/cmd_bootm.c All preparation done, transferring control to OS 1404 1405 -1 common/cmd_doc.c Bad usage of "doc" command 1406 -1 common/cmd_doc.c No boot device 1407 -1 common/cmd_doc.c Unknown Chip ID on boot device 1408 -1 common/cmd_doc.c Read Error on boot device 1409 -1 common/cmd_doc.c Image header has bad magic number 1410 1411 -1 common/cmd_ide.c Bad usage of "ide" command 1412 -1 common/cmd_ide.c No boot device 1413 -1 common/cmd_ide.c Unknown boot device 1414 -1 common/cmd_ide.c Unknown partition table 1415 -1 common/cmd_ide.c Invalid partition type 1416 -1 common/cmd_ide.c Read Error on boot device 1417 -1 common/cmd_ide.c Image header has bad magic number 1418 1419 -1 common/cmd_nand.c Bad usage of "nand" command 1420 -1 common/cmd_nand.c No boot device 1421 -1 common/cmd_nand.c Unknown Chip ID on boot device 1422 -1 common/cmd_nand.c Read Error on boot device 1423 -1 common/cmd_nand.c Image header has bad magic number 1424 1425 -1 common/env_common.c Environment has a bad CRC, using default 1426 1427 1428Modem Support: 1429-------------- 1430 1431[so far only for SMDK2400 and TRAB boards] 1432 1433- Modem support endable: 1434 CONFIG_MODEM_SUPPORT 1435 1436- RTS/CTS Flow control enable: 1437 CONFIG_HWFLOW 1438 1439- Modem debug support: 1440 CONFIG_MODEM_SUPPORT_DEBUG 1441 1442 Enables debugging stuff (char screen[1024], dbg()) 1443 for modem support. Useful only with BDI2000. 1444 1445- General: 1446 1447 In the target system modem support is enabled when a 1448 specific key (key combination) is pressed during 1449 power-on. Otherwise U-Boot will boot normally 1450 (autoboot). The key_pressed() fuction is called from 1451 board_init(). Currently key_pressed() is a dummy 1452 function, returning 1 and thus enabling modem 1453 initialization. 1454 1455 If there are no modem init strings in the 1456 environment, U-Boot proceed to autoboot; the 1457 previous output (banner, info printfs) will be 1458 supressed, though. 1459 1460 See also: doc/README.Modem 1461 1462 1463Configuration Settings: 1464----------------------- 1465 1466- CFG_LONGHELP: Defined when you want long help messages included; 1467 undefine this when you're short of memory. 1468 1469- CFG_PROMPT: This is what U-Boot prints on the console to 1470 prompt for user input. 1471 1472- CFG_CBSIZE: Buffer size for input from the Console 1473 1474- CFG_PBSIZE: Buffer size for Console output 1475 1476- CFG_MAXARGS: max. Number of arguments accepted for monitor commands 1477 1478- CFG_BARGSIZE: Buffer size for Boot Arguments which are passed to 1479 the application (usually a Linux kernel) when it is 1480 booted 1481 1482- CFG_BAUDRATE_TABLE: 1483 List of legal baudrate settings for this board. 1484 1485- CFG_CONSOLE_INFO_QUIET 1486 Suppress display of console information at boot. 1487 1488- CFG_CONSOLE_IS_IN_ENV 1489 If the board specific function 1490 extern int overwrite_console (void); 1491 returns 1, the stdin, stderr and stdout are switched to the 1492 serial port, else the settings in the environment are used. 1493 1494- CFG_CONSOLE_OVERWRITE_ROUTINE 1495 Enable the call to overwrite_console(). 1496 1497- CFG_CONSOLE_ENV_OVERWRITE 1498 Enable overwrite of previous console environment settings. 1499 1500- CFG_MEMTEST_START, CFG_MEMTEST_END: 1501 Begin and End addresses of the area used by the 1502 simple memory test. 1503 1504- CFG_ALT_MEMTEST: 1505 Enable an alternate, more extensive memory test. 1506 1507- CFG_MEMTEST_SCRATCH: 1508 Scratch address used by the alternate memory test 1509 You only need to set this if address zero isn't writeable 1510 1511- CFG_TFTP_LOADADDR: 1512 Default load address for network file downloads 1513 1514- CFG_LOADS_BAUD_CHANGE: 1515 Enable temporary baudrate change while serial download 1516 1517- CFG_SDRAM_BASE: 1518 Physical start address of SDRAM. _Must_ be 0 here. 1519 1520- CFG_MBIO_BASE: 1521 Physical start address of Motherboard I/O (if using a 1522 Cogent motherboard) 1523 1524- CFG_FLASH_BASE: 1525 Physical start address of Flash memory. 1526 1527- CFG_MONITOR_BASE: 1528 Physical start address of boot monitor code (set by 1529 make config files to be same as the text base address 1530 (TEXT_BASE) used when linking) - same as 1531 CFG_FLASH_BASE when booting from flash. 1532 1533- CFG_MONITOR_LEN: 1534 Size of memory reserved for monitor code, used to 1535 determine _at_compile_time_ (!) if the environment is 1536 embedded within the U-Boot image, or in a separate 1537 flash sector. 1538 1539- CFG_MALLOC_LEN: 1540 Size of DRAM reserved for malloc() use. 1541 1542- CFG_BOOTMAPSZ: 1543 Maximum size of memory mapped by the startup code of 1544 the Linux kernel; all data that must be processed by 1545 the Linux kernel (bd_info, boot arguments, eventually 1546 initrd image) must be put below this limit. 1547 1548- CFG_MAX_FLASH_BANKS: 1549 Max number of Flash memory banks 1550 1551- CFG_MAX_FLASH_SECT: 1552 Max number of sectors on a Flash chip 1553 1554- CFG_FLASH_ERASE_TOUT: 1555 Timeout for Flash erase operations (in ms) 1556 1557- CFG_FLASH_WRITE_TOUT: 1558 Timeout for Flash write operations (in ms) 1559 1560- CFG_FLASH_LOCK_TOUT 1561 Timeout for Flash set sector lock bit operation (in ms) 1562 1563- CFG_FLASH_UNLOCK_TOUT 1564 Timeout for Flash clear lock bits operation (in ms) 1565 1566- CFG_FLASH_PROTECTION 1567 If defined, hardware flash sectors protection is used 1568 instead of U-Boot software protection. 1569 1570- CFG_DIRECT_FLASH_TFTP: 1571 1572 Enable TFTP transfers directly to flash memory; 1573 without this option such a download has to be 1574 performed in two steps: (1) download to RAM, and (2) 1575 copy from RAM to flash. 1576 1577 The two-step approach is usually more reliable, since 1578 you can check if the download worked before you erase 1579 the flash, but in some situations (when sytem RAM is 1580 too limited to allow for a tempory copy of the 1581 downloaded image) this option may be very useful. 1582 1583- CFG_FLASH_CFI: 1584 Define if the flash driver uses extra elements in the 1585 common flash structure for storing flash geometry 1586 1587- CFG_RX_ETH_BUFFER: 1588 Defines the number of ethernet receive buffers. On some 1589 ethernet controllers it is recommended to set this value 1590 to 8 or even higher (EEPRO100 or 405 EMAC), since all 1591 buffers can be full shortly after enabling the interface 1592 on high ethernet traffic. 1593 Defaults to 4 if not defined. 1594 1595The following definitions that deal with the placement and management 1596of environment data (variable area); in general, we support the 1597following configurations: 1598 1599- CFG_ENV_IS_IN_FLASH: 1600 1601 Define this if the environment is in flash memory. 1602 1603 a) The environment occupies one whole flash sector, which is 1604 "embedded" in the text segment with the U-Boot code. This 1605 happens usually with "bottom boot sector" or "top boot 1606 sector" type flash chips, which have several smaller 1607 sectors at the start or the end. For instance, such a 1608 layout can have sector sizes of 8, 2x4, 16, Nx32 kB. In 1609 such a case you would place the environment in one of the 1610 4 kB sectors - with U-Boot code before and after it. With 1611 "top boot sector" type flash chips, you would put the 1612 environment in one of the last sectors, leaving a gap 1613 between U-Boot and the environment. 1614 1615 - CFG_ENV_OFFSET: 1616 1617 Offset of environment data (variable area) to the 1618 beginning of flash memory; for instance, with bottom boot 1619 type flash chips the second sector can be used: the offset 1620 for this sector is given here. 1621 1622 CFG_ENV_OFFSET is used relative to CFG_FLASH_BASE. 1623 1624 - CFG_ENV_ADDR: 1625 1626 This is just another way to specify the start address of 1627 the flash sector containing the environment (instead of 1628 CFG_ENV_OFFSET). 1629 1630 - CFG_ENV_SECT_SIZE: 1631 1632 Size of the sector containing the environment. 1633 1634 1635 b) Sometimes flash chips have few, equal sized, BIG sectors. 1636 In such a case you don't want to spend a whole sector for 1637 the environment. 1638 1639 - CFG_ENV_SIZE: 1640 1641 If you use this in combination with CFG_ENV_IS_IN_FLASH 1642 and CFG_ENV_SECT_SIZE, you can specify to use only a part 1643 of this flash sector for the environment. This saves 1644 memory for the RAM copy of the environment. 1645 1646 It may also save flash memory if you decide to use this 1647 when your environment is "embedded" within U-Boot code, 1648 since then the remainder of the flash sector could be used 1649 for U-Boot code. It should be pointed out that this is 1650 STRONGLY DISCOURAGED from a robustness point of view: 1651 updating the environment in flash makes it always 1652 necessary to erase the WHOLE sector. If something goes 1653 wrong before the contents has been restored from a copy in 1654 RAM, your target system will be dead. 1655 1656 - CFG_ENV_ADDR_REDUND 1657 CFG_ENV_SIZE_REDUND 1658 1659 These settings describe a second storage area used to hold 1660 a redundand copy of the environment data, so that there is 1661 a valid backup copy in case there is a power failure during 1662 a "saveenv" operation. 1663 1664BE CAREFUL! Any changes to the flash layout, and some changes to the 1665source code will make it necessary to adapt <board>/u-boot.lds* 1666accordingly! 1667 1668 1669- CFG_ENV_IS_IN_NVRAM: 1670 1671 Define this if you have some non-volatile memory device 1672 (NVRAM, battery buffered SRAM) which you want to use for the 1673 environment. 1674 1675 - CFG_ENV_ADDR: 1676 - CFG_ENV_SIZE: 1677 1678 These two #defines are used to determin the memory area you 1679 want to use for environment. It is assumed that this memory 1680 can just be read and written to, without any special 1681 provision. 1682 1683BE CAREFUL! The first access to the environment happens quite early 1684in U-Boot initalization (when we try to get the setting of for the 1685console baudrate). You *MUST* have mappend your NVRAM area then, or 1686U-Boot will hang. 1687 1688Please note that even with NVRAM we still use a copy of the 1689environment in RAM: we could work on NVRAM directly, but we want to 1690keep settings there always unmodified except somebody uses "saveenv" 1691to save the current settings. 1692 1693 1694- CFG_ENV_IS_IN_EEPROM: 1695 1696 Use this if you have an EEPROM or similar serial access 1697 device and a driver for it. 1698 1699 - CFG_ENV_OFFSET: 1700 - CFG_ENV_SIZE: 1701 1702 These two #defines specify the offset and size of the 1703 environment area within the total memory of your EEPROM. 1704 1705 - CFG_I2C_EEPROM_ADDR: 1706 If defined, specified the chip address of the EEPROM device. 1707 The default address is zero. 1708 1709 - CFG_EEPROM_PAGE_WRITE_BITS: 1710 If defined, the number of bits used to address bytes in a 1711 single page in the EEPROM device. A 64 byte page, for example 1712 would require six bits. 1713 1714 - CFG_EEPROM_PAGE_WRITE_DELAY_MS: 1715 If defined, the number of milliseconds to delay between 1716 page writes. The default is zero milliseconds. 1717 1718 - CFG_I2C_EEPROM_ADDR_LEN: 1719 The length in bytes of the EEPROM memory array address. Note 1720 that this is NOT the chip address length! 1721 1722 - CFG_EEPROM_SIZE: 1723 The size in bytes of the EEPROM device. 1724 1725 1726- CFG_SPI_INIT_OFFSET 1727 1728 Defines offset to the initial SPI buffer area in DPRAM. The 1729 area is used at an early stage (ROM part) if the environment 1730 is configured to reside in the SPI EEPROM: We need a 520 byte 1731 scratch DPRAM area. It is used between the two initialization 1732 calls (spi_init_f() and spi_init_r()). A value of 0xB00 seems 1733 to be a good choice since it makes it far enough from the 1734 start of the data area as well as from the stack pointer. 1735 1736Please note that the environment is read-only as long as the monitor 1737has been relocated to RAM and a RAM copy of the environment has been 1738created; also, when using EEPROM you will have to use getenv_r() 1739until then to read environment variables. 1740 1741The environment is protected by a CRC32 checksum. Before the monitor 1742is relocated into RAM, as a result of a bad CRC you will be working 1743with the compiled-in default environment - *silently*!!! [This is 1744necessary, because the first environment variable we need is the 1745"baudrate" setting for the console - if we have a bad CRC, we don't 1746have any device yet where we could complain.] 1747 1748Note: once the monitor has been relocated, then it will complain if 1749the default environment is used; a new CRC is computed as soon as you 1750use the "saveenv" command to store a valid environment. 1751 1752 1753Low Level (hardware related) configuration options: 1754--------------------------------------------------- 1755 1756- CFG_CACHELINE_SIZE: 1757 Cache Line Size of the CPU. 1758 1759- CFG_DEFAULT_IMMR: 1760 Default address of the IMMR after system reset. 1761 1762 Needed on some 8260 systems (MPC8260ADS, PQ2FADS-ZU, 1763 and RPXsuper) to be able to adjust the position of 1764 the IMMR register after a reset. 1765 1766- Floppy Disk Support: 1767 CFG_FDC_DRIVE_NUMBER 1768 1769 the default drive number (default value 0) 1770 1771 CFG_ISA_IO_STRIDE 1772 1773 defines the spacing between fdc chipset registers 1774 (default value 1) 1775 1776 CFG_ISA_IO_OFFSET 1777 1778 defines the offset of register from address. It 1779 depends on which part of the data bus is connected to 1780 the fdc chipset. (default value 0) 1781 1782 If CFG_ISA_IO_STRIDE CFG_ISA_IO_OFFSET and 1783 CFG_FDC_DRIVE_NUMBER are undefined, they take their 1784 default value. 1785 1786 if CFG_FDC_HW_INIT is defined, then the function 1787 fdc_hw_init() is called at the beginning of the FDC 1788 setup. fdc_hw_init() must be provided by the board 1789 source code. It is used to make hardware dependant 1790 initializations. 1791 1792- CFG_IMMR: Physical address of the Internal Memory Mapped 1793 Register; DO NOT CHANGE! (11-4) 1794 [MPC8xx systems only] 1795 1796- CFG_INIT_RAM_ADDR: 1797 1798 Start address of memory area that can be used for 1799 initial data and stack; please note that this must be 1800 writable memory that is working WITHOUT special 1801 initialization, i. e. you CANNOT use normal RAM which 1802 will become available only after programming the 1803 memory controller and running certain initialization 1804 sequences. 1805 1806 U-Boot uses the following memory types: 1807 - MPC8xx and MPC8260: IMMR (internal memory of the CPU) 1808 - MPC824X: data cache 1809 - PPC4xx: data cache 1810 1811- CFG_GBL_DATA_OFFSET: 1812 1813 Offset of the initial data structure in the memory 1814 area defined by CFG_INIT_RAM_ADDR. Usually 1815 CFG_GBL_DATA_OFFSET is chosen such that the initial 1816 data is located at the end of the available space 1817 (sometimes written as (CFG_INIT_RAM_END - 1818 CFG_INIT_DATA_SIZE), and the initial stack is just 1819 below that area (growing from (CFG_INIT_RAM_ADDR + 1820 CFG_GBL_DATA_OFFSET) downward. 1821 1822 Note: 1823 On the MPC824X (or other systems that use the data 1824 cache for initial memory) the address chosen for 1825 CFG_INIT_RAM_ADDR is basically arbitrary - it must 1826 point to an otherwise UNUSED address space between 1827 the top of RAM and the start of the PCI space. 1828 1829- CFG_SIUMCR: SIU Module Configuration (11-6) 1830 1831- CFG_SYPCR: System Protection Control (11-9) 1832 1833- CFG_TBSCR: Time Base Status and Control (11-26) 1834 1835- CFG_PISCR: Periodic Interrupt Status and Control (11-31) 1836 1837- CFG_PLPRCR: PLL, Low-Power, and Reset Control Register (15-30) 1838 1839- CFG_SCCR: System Clock and reset Control Register (15-27) 1840 1841- CFG_OR_TIMING_SDRAM: 1842 SDRAM timing 1843 1844- CFG_MAMR_PTA: 1845 periodic timer for refresh 1846 1847- CFG_DER: Debug Event Register (37-47) 1848 1849- FLASH_BASE0_PRELIM, FLASH_BASE1_PRELIM, CFG_REMAP_OR_AM, 1850 CFG_PRELIM_OR_AM, CFG_OR_TIMING_FLASH, CFG_OR0_REMAP, 1851 CFG_OR0_PRELIM, CFG_BR0_PRELIM, CFG_OR1_REMAP, CFG_OR1_PRELIM, 1852 CFG_BR1_PRELIM: 1853 Memory Controller Definitions: BR0/1 and OR0/1 (FLASH) 1854 1855- SDRAM_BASE2_PRELIM, SDRAM_BASE3_PRELIM, SDRAM_MAX_SIZE, 1856 CFG_OR_TIMING_SDRAM, CFG_OR2_PRELIM, CFG_BR2_PRELIM, 1857 CFG_OR3_PRELIM, CFG_BR3_PRELIM: 1858 Memory Controller Definitions: BR2/3 and OR2/3 (SDRAM) 1859 1860- CFG_MAMR_PTA, CFG_MPTPR_2BK_4K, CFG_MPTPR_1BK_4K, CFG_MPTPR_2BK_8K, 1861 CFG_MPTPR_1BK_8K, CFG_MAMR_8COL, CFG_MAMR_9COL: 1862 Machine Mode Register and Memory Periodic Timer 1863 Prescaler definitions (SDRAM timing) 1864 1865- CFG_I2C_UCODE_PATCH, CFG_I2C_DPMEM_OFFSET [0x1FC0]: 1866 enable I2C microcode relocation patch (MPC8xx); 1867 define relocation offset in DPRAM [DSP2] 1868 1869- CFG_SPI_UCODE_PATCH, CFG_SPI_DPMEM_OFFSET [0x1FC0]: 1870 enable SPI microcode relocation patch (MPC8xx); 1871 define relocation offset in DPRAM [SCC4] 1872 1873- CFG_USE_OSCCLK: 1874 Use OSCM clock mode on MBX8xx board. Be careful, 1875 wrong setting might damage your board. Read 1876 doc/README.MBX before setting this variable! 1877 1878- CFG_CPM_POST_WORD_ADDR: (MPC8xx, MPC8260 only) 1879 Offset of the bootmode word in DPRAM used by post 1880 (Power On Self Tests). This definition overrides 1881 #define'd default value in commproc.h resp. 1882 cpm_8260.h. 1883 1884- CFG_PCI_SLV_MEM_LOCAL, CFG_PCI_SLV_MEM_BUS, CFG_PICMR0_MASK_ATTRIB, 1885 CFG_PCI_MSTR0_LOCAL, CFG_PCIMSK0_MASK, CFG_PCI_MSTR1_LOCAL, 1886 CFG_PCIMSK1_MASK, CFG_PCI_MSTR_MEM_LOCAL, CFG_PCI_MSTR_MEM_BUS, 1887 CFG_CPU_PCI_MEM_START, CFG_PCI_MSTR_MEM_SIZE, CFG_POCMR0_MASK_ATTRIB, 1888 CFG_PCI_MSTR_MEMIO_LOCAL, CFG_PCI_MSTR_MEMIO_BUS, CPU_PCI_MEMIO_START, 1889 CFG_PCI_MSTR_MEMIO_SIZE, CFG_POCMR1_MASK_ATTRIB, CFG_PCI_MSTR_IO_LOCAL, 1890 CFG_PCI_MSTR_IO_BUS, CFG_CPU_PCI_IO_START, CFG_PCI_MSTR_IO_SIZE, 1891 CFG_POCMR2_MASK_ATTRIB: (MPC826x only) 1892 Overrides the default PCI memory map in cpu/mpc8260/pci.c if set. 1893 1894Building the Software: 1895====================== 1896 1897Building U-Boot has been tested in native PPC environments (on a 1898PowerBook G3 running LinuxPPC 2000) and in cross environments 1899(running RedHat 6.x and 7.x Linux on x86, Solaris 2.6 on a SPARC, and 1900NetBSD 1.5 on x86). 1901 1902If you are not using a native PPC environment, it is assumed that you 1903have the GNU cross compiling tools available in your path and named 1904with a prefix of "powerpc-linux-". If this is not the case, (e.g. if 1905you are using Monta Vista's Hard Hat Linux CDK 1.2) you must change 1906the definition of CROSS_COMPILE in Makefile. For HHL on a 4xx CPU, 1907change it to: 1908 1909 CROSS_COMPILE = ppc_4xx- 1910 1911 1912U-Boot is intended to be simple to build. After installing the 1913sources you must configure U-Boot for one specific board type. This 1914is done by typing: 1915 1916 make NAME_config 1917 1918where "NAME_config" is the name of one of the existing 1919configurations; the following names are supported: 1920 1921 ADCIOP_config GTH_config TQM850L_config 1922 ADS860_config IP860_config TQM855L_config 1923 AR405_config IVML24_config TQM860L_config 1924 CANBT_config IVMS8_config WALNUT405_config 1925 CPCI405_config LANTEC_config cogent_common_config 1926 CPCIISER4_config MBX_config cogent_mpc8260_config 1927 CU824_config MBX860T_config cogent_mpc8xx_config 1928 ESTEEM192E_config RPXlite_config hermes_config 1929 ETX094_config RPXsuper_config hymod_config 1930 FADS823_config SM850_config lwmon_config 1931 FADS850SAR_config SPD823TS_config pcu_e_config 1932 FADS860T_config SXNI855T_config rsdproto_config 1933 FPS850L_config Sandpoint8240_config sbc8260_config 1934 GENIETV_config TQM823L_config PIP405_config 1935 GEN860T_config EBONY_config FPS860L_config 1936 ELPT860_config cmi_mpc5xx_config NETVIA_config 1937 at91rm9200dk_config omap1510inn_config MPC8260ADS_config 1938 omap1610inn_config 1939Note: for some board special configuration names may exist; check if 1940 additional information is available from the board vendor; for 1941 instance, the TQM8xxL systems run normally at 50 MHz and use a 1942 SCC for 10baseT ethernet; there are also systems with 80 MHz 1943 CPU clock, and an optional Fast Ethernet module is available 1944 for CPU's with FEC. You can select such additional "features" 1945 when chosing the configuration, i. e. 1946 1947 make TQM860L_config 1948 - will configure for a plain TQM860L, i. e. 50MHz, no FEC 1949 1950 make TQM860L_FEC_config 1951 - will configure for a TQM860L at 50MHz with FEC for ethernet 1952 1953 make TQM860L_80MHz_config 1954 - will configure for a TQM860L at 80 MHz, with normal 10baseT 1955 interface 1956 1957 make TQM860L_FEC_80MHz_config 1958 - will configure for a TQM860L at 80 MHz with FEC for ethernet 1959 1960 make TQM823L_LCD_config 1961 - will configure for a TQM823L with U-Boot console on LCD 1962 1963 make TQM823L_LCD_80MHz_config 1964 - will configure for a TQM823L at 80 MHz with U-Boot console on LCD 1965 1966 etc. 1967 1968 1969Finally, type "make all", and you should get some working U-Boot 1970images ready for download to / installation on your system: 1971 1972- "u-boot.bin" is a raw binary image 1973- "u-boot" is an image in ELF binary format 1974- "u-boot.srec" is in Motorola S-Record format 1975 1976 1977Please be aware that the Makefiles assume you are using GNU make, so 1978for instance on NetBSD you might need to use "gmake" instead of 1979native "make". 1980 1981 1982If the system board that you have is not listed, then you will need 1983to port U-Boot to your hardware platform. To do this, follow these 1984steps: 1985 19861. Add a new configuration option for your board to the toplevel 1987 "Makefile" and to the "MAKEALL" script, using the existing 1988 entries as examples. Note that here and at many other places 1989 boards and other names are listed in alphabetical sort order. Please 1990 keep this order. 19912. Create a new directory to hold your board specific code. Add any 1992 files you need. In your board directory, you will need at least 1993 the "Makefile", a "<board>.c", "flash.c" and "u-boot.lds". 19943. Create a new configuration file "include/configs/<board>.h" for 1995 your board 19963. If you're porting U-Boot to a new CPU, then also create a new 1997 directory to hold your CPU specific code. Add any files you need. 19984. Run "make <board>_config" with your new name. 19995. Type "make", and you should get a working "u-boot.srec" file 2000 to be installed on your target system. 20016. Debug and solve any problems that might arise. 2002 [Of course, this last step is much harder than it sounds.] 2003 2004 2005Testing of U-Boot Modifications, Ports to New Hardware, etc.: 2006============================================================== 2007 2008If you have modified U-Boot sources (for instance added a new board 2009or support for new devices, a new CPU, etc.) you are expected to 2010provide feedback to the other developers. The feedback normally takes 2011the form of a "patch", i. e. a context diff against a certain (latest 2012official or latest in CVS) version of U-Boot sources. 2013 2014But before you submit such a patch, please verify that your modifi- 2015cation did not break existing code. At least make sure that *ALL* of 2016the supported boards compile WITHOUT ANY compiler warnings. To do so, 2017just run the "MAKEALL" script, which will configure and build U-Boot 2018for ALL supported system. Be warned, this will take a while. You can 2019select which (cross) compiler to use by passing a `CROSS_COMPILE' 2020environment variable to the script, i. e. to use the cross tools from 2021MontaVista's Hard Hat Linux you can type 2022 2023 CROSS_COMPILE=ppc_8xx- MAKEALL 2024 2025or to build on a native PowerPC system you can type 2026 2027 CROSS_COMPILE=' ' MAKEALL 2028 2029See also "U-Boot Porting Guide" below. 2030 2031 2032Monitor Commands - Overview: 2033============================ 2034 2035go - start application at address 'addr' 2036run - run commands in an environment variable 2037bootm - boot application image from memory 2038bootp - boot image via network using BootP/TFTP protocol 2039tftpboot- boot image via network using TFTP protocol 2040 and env variables "ipaddr" and "serverip" 2041 (and eventually "gatewayip") 2042rarpboot- boot image via network using RARP/TFTP protocol 2043diskboot- boot from IDE devicebootd - boot default, i.e., run 'bootcmd' 2044loads - load S-Record file over serial line 2045loadb - load binary file over serial line (kermit mode) 2046md - memory display 2047mm - memory modify (auto-incrementing) 2048nm - memory modify (constant address) 2049mw - memory write (fill) 2050cp - memory copy 2051cmp - memory compare 2052crc32 - checksum calculation 2053imd - i2c memory display 2054imm - i2c memory modify (auto-incrementing) 2055inm - i2c memory modify (constant address) 2056imw - i2c memory write (fill) 2057icrc32 - i2c checksum calculation 2058iprobe - probe to discover valid I2C chip addresses 2059iloop - infinite loop on address range 2060isdram - print SDRAM configuration information 2061sspi - SPI utility commands 2062base - print or set address offset 2063printenv- print environment variables 2064setenv - set environment variables 2065saveenv - save environment variables to persistent storage 2066protect - enable or disable FLASH write protection 2067erase - erase FLASH memory 2068flinfo - print FLASH memory information 2069bdinfo - print Board Info structure 2070iminfo - print header information for application image 2071coninfo - print console devices and informations 2072ide - IDE sub-system 2073loop - infinite loop on address range 2074mtest - simple RAM test 2075icache - enable or disable instruction cache 2076dcache - enable or disable data cache 2077reset - Perform RESET of the CPU 2078echo - echo args to console 2079version - print monitor version 2080help - print online help 2081? - alias for 'help' 2082 2083 2084Monitor Commands - Detailed Description: 2085======================================== 2086 2087TODO. 2088 2089For now: just type "help <command>". 2090 2091 2092Environment Variables: 2093====================== 2094 2095U-Boot supports user configuration using Environment Variables which 2096can be made persistent by saving to Flash memory. 2097 2098Environment Variables are set using "setenv", printed using 2099"printenv", and saved to Flash using "saveenv". Using "setenv" 2100without a value can be used to delete a variable from the 2101environment. As long as you don't save the environment you are 2102working with an in-memory copy. In case the Flash area containing the 2103environment is erased by accident, a default environment is provided. 2104 2105Some configuration options can be set using Environment Variables: 2106 2107 baudrate - see CONFIG_BAUDRATE 2108 2109 bootdelay - see CONFIG_BOOTDELAY 2110 2111 bootcmd - see CONFIG_BOOTCOMMAND 2112 2113 bootargs - Boot arguments when booting an RTOS image 2114 2115 bootfile - Name of the image to load with TFTP 2116 2117 autoload - if set to "no" (any string beginning with 'n'), 2118 "bootp" will just load perform a lookup of the 2119 configuration from the BOOTP server, but not try to 2120 load any image using TFTP 2121 2122 autostart - if set to "yes", an image loaded using the "bootp", 2123 "rarpboot", "tftpboot" or "diskboot" commands will 2124 be automatically started (by internally calling 2125 "bootm") 2126 2127 If set to "no", a standalone image passed to the 2128 "bootm" command will be copied to the load address 2129 (and eventually uncompressed), but NOT be started. 2130 This can be used to load and uncompress arbitrary 2131 data. 2132 2133 initrd_high - restrict positioning of initrd images: 2134 If this variable is not set, initrd images will be 2135 copied to the highest possible address in RAM; this 2136 is usually what you want since it allows for 2137 maximum initrd size. If for some reason you want to 2138 make sure that the initrd image is loaded below the 2139 CFG_BOOTMAPSZ limit, you can set this environment 2140 variable to a value of "no" or "off" or "0". 2141 Alternatively, you can set it to a maximum upper 2142 address to use (U-Boot will still check that it 2143 does not overwrite the U-Boot stack and data). 2144 2145 For instance, when you have a system with 16 MB 2146 RAM, and want to reserve 4 MB from use by Linux, 2147 you can do this by adding "mem=12M" to the value of 2148 the "bootargs" variable. However, now you must make 2149 sure that the initrd image is placed in the first 2150 12 MB as well - this can be done with 2151 2152 setenv initrd_high 00c00000 2153 2154 If you set initrd_high to 0xFFFFFFFF, this is an 2155 indication to U-Boot that all addresses are legal 2156 for the Linux kernel, including addresses in flash 2157 memory. In this case U-Boot will NOT COPY the 2158 ramdisk at all. This may be useful to reduce the 2159 boot time on your system, but requires that this 2160 feature is supported by your Linux kernel. 2161 2162 ipaddr - IP address; needed for tftpboot command 2163 2164 loadaddr - Default load address for commands like "bootp", 2165 "rarpboot", "tftpboot", "loadb" or "diskboot" 2166 2167 loads_echo - see CONFIG_LOADS_ECHO 2168 2169 serverip - TFTP server IP address; needed for tftpboot command 2170 2171 bootretry - see CONFIG_BOOT_RETRY_TIME 2172 2173 bootdelaykey - see CONFIG_AUTOBOOT_DELAY_STR 2174 2175 bootstopkey - see CONFIG_AUTOBOOT_STOP_STR 2176 2177 2178The following environment variables may be used and automatically 2179updated by the network boot commands ("bootp" and "rarpboot"), 2180depending the information provided by your boot server: 2181 2182 bootfile - see above 2183 dnsip - IP address of your Domain Name Server 2184 dnsip2 - IP address of your secondary Domain Name Server 2185 gatewayip - IP address of the Gateway (Router) to use 2186 hostname - Target hostname 2187 ipaddr - see above 2188 netmask - Subnet Mask 2189 rootpath - Pathname of the root filesystem on the NFS server 2190 serverip - see above 2191 2192 2193There are two special Environment Variables: 2194 2195 serial# - contains hardware identification information such 2196 as type string and/or serial number 2197 ethaddr - Ethernet address 2198 2199These variables can be set only once (usually during manufacturing of 2200the board). U-Boot refuses to delete or overwrite these variables 2201once they have been set once. 2202 2203 2204Further special Environment Variables: 2205 2206 ver - Contains the U-Boot version string as printed 2207 with the "version" command. This variable is 2208 readonly (see CONFIG_VERSION_VARIABLE). 2209 2210 2211Please note that changes to some configuration parameters may take 2212only effect after the next boot (yes, that's just like Windoze :-). 2213 2214 2215Command Line Parsing: 2216===================== 2217 2218There are two different command line parsers available with U-Boot: 2219the old "simple" one, and the much more powerful "hush" shell: 2220 2221Old, simple command line parser: 2222-------------------------------- 2223 2224- supports environment variables (through setenv / saveenv commands) 2225- several commands on one line, separated by ';' 2226- variable substitution using "... $(name) ..." syntax 2227- special characters ('$', ';') can be escaped by prefixing with '\', 2228 for example: 2229 setenv bootcmd bootm \$(address) 2230- You can also escape text by enclosing in single apostrophes, for example: 2231 setenv addip 'setenv bootargs $bootargs ip=$ipaddr:$serverip:$gatewayip:$netmask:$hostname::off' 2232 2233Hush shell: 2234----------- 2235 2236- similar to Bourne shell, with control structures like 2237 if...then...else...fi, for...do...done; while...do...done, 2238 until...do...done, ... 2239- supports environment ("global") variables (through setenv / saveenv 2240 commands) and local shell variables (through standard shell syntax 2241 "name=value"); only environment variables can be used with "run" 2242 command 2243 2244General rules: 2245-------------- 2246 2247(1) If a command line (or an environment variable executed by a "run" 2248 command) contains several commands separated by semicolon, and 2249 one of these commands fails, then the remaining commands will be 2250 executed anyway. 2251 2252(2) If you execute several variables with one call to run (i. e. 2253 calling run with a list af variables as arguments), any failing 2254 command will cause "run" to terminate, i. e. the remaining 2255 variables are not executed. 2256 2257Note for Redundant Ethernet Interfaces: 2258======================================= 2259 2260Some boards come with redundant ethernet interfaces; U-Boot supports 2261such configurations and is capable of automatic selection of a 2262"working" interface when needed. MAC assignment works as follows: 2263 2264Network interfaces are numbered eth0, eth1, eth2, ... Corresponding 2265MAC addresses can be stored in the environment as "ethaddr" (=>eth0), 2266"eth1addr" (=>eth1), "eth2addr", ... 2267 2268If the network interface stores some valid MAC address (for instance 2269in SROM), this is used as default address if there is NO correspon- 2270ding setting in the environment; if the corresponding environment 2271variable is set, this overrides the settings in the card; that means: 2272 2273o If the SROM has a valid MAC address, and there is no address in the 2274 environment, the SROM's address is used. 2275 2276o If there is no valid address in the SROM, and a definition in the 2277 environment exists, then the value from the environment variable is 2278 used. 2279 2280o If both the SROM and the environment contain a MAC address, and 2281 both addresses are the same, this MAC address is used. 2282 2283o If both the SROM and the environment contain a MAC address, and the 2284 addresses differ, the value from the environment is used and a 2285 warning is printed. 2286 2287o If neither SROM nor the environment contain a MAC address, an error 2288 is raised. 2289 2290 2291Image Formats: 2292============== 2293 2294The "boot" commands of this monitor operate on "image" files which 2295can be basicly anything, preceeded by a special header; see the 2296definitions in include/image.h for details; basicly, the header 2297defines the following image properties: 2298 2299* Target Operating System (Provisions for OpenBSD, NetBSD, FreeBSD, 2300 4.4BSD, Linux, SVR4, Esix, Solaris, Irix, SCO, Dell, NCR, VxWorks, 2301 LynxOS, pSOS, QNX, RTEMS, ARTOS; 2302 Currently supported: Linux, NetBSD, VxWorks, QNX, RTEMS, ARTOS, LynxOS). 2303* Target CPU Architecture (Provisions for Alpha, ARM, Intel x86, 2304 IA64, MIPS, MIPS, PowerPC, IBM S390, SuperH, Sparc, Sparc 64 Bit; 2305 Currently supported: PowerPC). 2306* Compression Type (uncompressed, gzip, bzip2) 2307* Load Address 2308* Entry Point 2309* Image Name 2310* Image Timestamp 2311 2312The header is marked by a special Magic Number, and both the header 2313and the data portions of the image are secured against corruption by 2314CRC32 checksums. 2315 2316 2317Linux Support: 2318============== 2319 2320Although U-Boot should support any OS or standalone application 2321easily, the main focus has always been on Linux during the design of 2322U-Boot. 2323 2324U-Boot includes many features that so far have been part of some 2325special "boot loader" code within the Linux kernel. Also, any 2326"initrd" images to be used are no longer part of one big Linux image; 2327instead, kernel and "initrd" are separate images. This implementation 2328serves several purposes: 2329 2330- the same features can be used for other OS or standalone 2331 applications (for instance: using compressed images to reduce the 2332 Flash memory footprint) 2333 2334- it becomes much easier to port new Linux kernel versions because 2335 lots of low-level, hardware dependent stuff are done by U-Boot 2336 2337- the same Linux kernel image can now be used with different "initrd" 2338 images; of course this also means that different kernel images can 2339 be run with the same "initrd". This makes testing easier (you don't 2340 have to build a new "zImage.initrd" Linux image when you just 2341 change a file in your "initrd"). Also, a field-upgrade of the 2342 software is easier now. 2343 2344 2345Linux HOWTO: 2346============ 2347 2348Porting Linux to U-Boot based systems: 2349--------------------------------------- 2350 2351U-Boot cannot save you from doing all the necessary modifications to 2352configure the Linux device drivers for use with your target hardware 2353(no, we don't intend to provide a full virtual machine interface to 2354Linux :-). 2355 2356But now you can ignore ALL boot loader code (in arch/ppc/mbxboot). 2357 2358Just make sure your machine specific header file (for instance 2359include/asm-ppc/tqm8xx.h) includes the same definition of the Board 2360Information structure as we define in include/u-boot.h, and make 2361sure that your definition of IMAP_ADDR uses the same value as your 2362U-Boot configuration in CFG_IMMR. 2363 2364 2365Configuring the Linux kernel: 2366----------------------------- 2367 2368No specific requirements for U-Boot. Make sure you have some root 2369device (initial ramdisk, NFS) for your target system. 2370 2371 2372Building a Linux Image: 2373----------------------- 2374 2375With U-Boot, "normal" build targets like "zImage" or "bzImage" are 2376not used. If you use recent kernel source, a new build target 2377"uImage" will exist which automatically builds an image usable by 2378U-Boot. Most older kernels also have support for a "pImage" target, 2379which was introduced for our predecessor project PPCBoot and uses a 2380100% compatible format. 2381 2382Example: 2383 2384 make TQM850L_config 2385 make oldconfig 2386 make dep 2387 make uImage 2388 2389The "uImage" build target uses a special tool (in 'tools/mkimage') to 2390encapsulate a compressed Linux kernel image with header information, 2391CRC32 checksum etc. for use with U-Boot. This is what we are doing: 2392 2393* build a standard "vmlinux" kernel image (in ELF binary format): 2394 2395* convert the kernel into a raw binary image: 2396 2397 ${CROSS_COMPILE}-objcopy -O binary \ 2398 -R .note -R .comment \ 2399 -S vmlinux linux.bin 2400 2401* compress the binary image: 2402 2403 gzip -9 linux.bin 2404 2405* package compressed binary image for U-Boot: 2406 2407 mkimage -A ppc -O linux -T kernel -C gzip \ 2408 -a 0 -e 0 -n "Linux Kernel Image" \ 2409 -d linux.bin.gz uImage 2410 2411 2412The "mkimage" tool can also be used to create ramdisk images for use 2413with U-Boot, either separated from the Linux kernel image, or 2414combined into one file. "mkimage" encapsulates the images with a 64 2415byte header containing information about target architecture, 2416operating system, image type, compression method, entry points, time 2417stamp, CRC32 checksums, etc. 2418 2419"mkimage" can be called in two ways: to verify existing images and 2420print the header information, or to build new images. 2421 2422In the first form (with "-l" option) mkimage lists the information 2423contained in the header of an existing U-Boot image; this includes 2424checksum verification: 2425 2426 tools/mkimage -l image 2427 -l ==> list image header information 2428 2429The second form (with "-d" option) is used to build a U-Boot image 2430from a "data file" which is used as image payload: 2431 2432 tools/mkimage -A arch -O os -T type -C comp -a addr -e ep \ 2433 -n name -d data_file image 2434 -A ==> set architecture to 'arch' 2435 -O ==> set operating system to 'os' 2436 -T ==> set image type to 'type' 2437 -C ==> set compression type 'comp' 2438 -a ==> set load address to 'addr' (hex) 2439 -e ==> set entry point to 'ep' (hex) 2440 -n ==> set image name to 'name' 2441 -d ==> use image data from 'datafile' 2442 2443Right now, all Linux kernels use the same load address (0x00000000), 2444but the entry point address depends on the kernel version: 2445 2446- 2.2.x kernels have the entry point at 0x0000000C, 2447- 2.3.x and later kernels have the entry point at 0x00000000. 2448 2449So a typical call to build a U-Boot image would read: 2450 2451 -> tools/mkimage -n '2.4.4 kernel for TQM850L' \ 2452 > -A ppc -O linux -T kernel -C gzip -a 0 -e 0 \ 2453 > -d /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/ppc/coffboot/vmlinux.gz \ 2454 > examples/uImage.TQM850L 2455 Image Name: 2.4.4 kernel for TQM850L 2456 Created: Wed Jul 19 02:34:59 2000 2457 Image Type: PowerPC Linux Kernel Image (gzip compressed) 2458 Data Size: 335725 Bytes = 327.86 kB = 0.32 MB 2459 Load Address: 0x00000000 2460 Entry Point: 0x00000000 2461 2462To verify the contents of the image (or check for corruption): 2463 2464 -> tools/mkimage -l examples/uImage.TQM850L 2465 Image Name: 2.4.4 kernel for TQM850L 2466 Created: Wed Jul 19 02:34:59 2000 2467 Image Type: PowerPC Linux Kernel Image (gzip compressed) 2468 Data Size: 335725 Bytes = 327.86 kB = 0.32 MB 2469 Load Address: 0x00000000 2470 Entry Point: 0x00000000 2471 2472NOTE: for embedded systems where boot time is critical you can trade 2473speed for memory and install an UNCOMPRESSED image instead: this 2474needs more space in Flash, but boots much faster since it does not 2475need to be uncompressed: 2476 2477 -> gunzip /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/ppc/coffboot/vmlinux.gz 2478 -> tools/mkimage -n '2.4.4 kernel for TQM850L' \ 2479 > -A ppc -O linux -T kernel -C none -a 0 -e 0 \ 2480 > -d /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/ppc/coffboot/vmlinux \ 2481 > examples/uImage.TQM850L-uncompressed 2482 Image Name: 2.4.4 kernel for TQM850L 2483 Created: Wed Jul 19 02:34:59 2000 2484 Image Type: PowerPC Linux Kernel Image (uncompressed) 2485 Data Size: 792160 Bytes = 773.59 kB = 0.76 MB 2486 Load Address: 0x00000000 2487 Entry Point: 0x00000000 2488 2489 2490Similar you can build U-Boot images from a 'ramdisk.image.gz' file 2491when your kernel is intended to use an initial ramdisk: 2492 2493 -> tools/mkimage -n 'Simple Ramdisk Image' \ 2494 > -A ppc -O linux -T ramdisk -C gzip \ 2495 > -d /LinuxPPC/images/SIMPLE-ramdisk.image.gz examples/simple-initrd 2496 Image Name: Simple Ramdisk Image 2497 Created: Wed Jan 12 14:01:50 2000 2498 Image Type: PowerPC Linux RAMDisk Image (gzip compressed) 2499 Data Size: 566530 Bytes = 553.25 kB = 0.54 MB 2500 Load Address: 0x00000000 2501 Entry Point: 0x00000000 2502 2503 2504Installing a Linux Image: 2505------------------------- 2506 2507To downloading a U-Boot image over the serial (console) interface, 2508you must convert the image to S-Record format: 2509 2510 objcopy -I binary -O srec examples/image examples/image.srec 2511 2512The 'objcopy' does not understand the information in the U-Boot 2513image header, so the resulting S-Record file will be relative to 2514address 0x00000000. To load it to a given address, you need to 2515specify the target address as 'offset' parameter with the 'loads' 2516command. 2517 2518Example: install the image to address 0x40100000 (which on the 2519TQM8xxL is in the first Flash bank): 2520 2521 => erase 40100000 401FFFFF 2522 2523 .......... done 2524 Erased 8 sectors 2525 2526 => loads 40100000 2527 ## Ready for S-Record download ... 2528 ~>examples/image.srec 2529 1 2 3 4 5 6 7 8 9 10 11 12 13 ... 2530 ... 2531 15989 15990 15991 15992 2532 [file transfer complete] 2533 [connected] 2534 ## Start Addr = 0x00000000 2535 2536 2537You can check the success of the download using the 'iminfo' command; 2538this includes a checksum verification so you can be sure no data 2539corruption happened: 2540 2541 => imi 40100000 2542 2543 ## Checking Image at 40100000 ... 2544 Image Name: 2.2.13 for initrd on TQM850L 2545 Image Type: PowerPC Linux Kernel Image (gzip compressed) 2546 Data Size: 335725 Bytes = 327 kB = 0 MB 2547 Load Address: 00000000 2548 Entry Point: 0000000c 2549 Verifying Checksum ... OK 2550 2551 2552Boot Linux: 2553----------- 2554 2555The "bootm" command is used to boot an application that is stored in 2556memory (RAM or Flash). In case of a Linux kernel image, the contents 2557of the "bootargs" environment variable is passed to the kernel as 2558parameters. You can check and modify this variable using the 2559"printenv" and "setenv" commands: 2560 2561 2562 => printenv bootargs 2563 bootargs=root=/dev/ram 2564 2565 => setenv bootargs root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2 2566 2567 => printenv bootargs 2568 bootargs=root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2 2569 2570 => bootm 40020000 2571 ## Booting Linux kernel at 40020000 ... 2572 Image Name: 2.2.13 for NFS on TQM850L 2573 Image Type: PowerPC Linux Kernel Image (gzip compressed) 2574 Data Size: 381681 Bytes = 372 kB = 0 MB 2575 Load Address: 00000000 2576 Entry Point: 0000000c 2577 Verifying Checksum ... OK 2578 Uncompressing Kernel Image ... OK 2579 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 2580 Boot arguments: root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2 2581 time_init: decrementer frequency = 187500000/60 2582 Calibrating delay loop... 49.77 BogoMIPS 2583 Memory: 15208k available (700k kernel code, 444k data, 32k init) [c0000000,c1000000] 2584 ... 2585 2586If you want to boot a Linux kernel with initial ram disk, you pass 2587the memory addresses of both the kernel and the initrd image (PPBCOOT 2588format!) to the "bootm" command: 2589 2590 => imi 40100000 40200000 2591 2592 ## Checking Image at 40100000 ... 2593 Image Name: 2.2.13 for initrd on TQM850L 2594 Image Type: PowerPC Linux Kernel Image (gzip compressed) 2595 Data Size: 335725 Bytes = 327 kB = 0 MB 2596 Load Address: 00000000 2597 Entry Point: 0000000c 2598 Verifying Checksum ... OK 2599 2600 ## Checking Image at 40200000 ... 2601 Image Name: Simple Ramdisk Image 2602 Image Type: PowerPC Linux RAMDisk Image (gzip compressed) 2603 Data Size: 566530 Bytes = 553 kB = 0 MB 2604 Load Address: 00000000 2605 Entry Point: 00000000 2606 Verifying Checksum ... OK 2607 2608 => bootm 40100000 40200000 2609 ## Booting Linux kernel at 40100000 ... 2610 Image Name: 2.2.13 for initrd on TQM850L 2611 Image Type: PowerPC Linux Kernel Image (gzip compressed) 2612 Data Size: 335725 Bytes = 327 kB = 0 MB 2613 Load Address: 00000000 2614 Entry Point: 0000000c 2615 Verifying Checksum ... OK 2616 Uncompressing Kernel Image ... OK 2617 ## Loading RAMDisk Image at 40200000 ... 2618 Image Name: Simple Ramdisk Image 2619 Image Type: PowerPC Linux RAMDisk Image (gzip compressed) 2620 Data Size: 566530 Bytes = 553 kB = 0 MB 2621 Load Address: 00000000 2622 Entry Point: 00000000 2623 Verifying Checksum ... OK 2624 Loading Ramdisk ... OK 2625 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 2626 Boot arguments: root=/dev/ram 2627 time_init: decrementer frequency = 187500000/60 2628 Calibrating delay loop... 49.77 BogoMIPS 2629 ... 2630 RAMDISK: Compressed image found at block 0 2631 VFS: Mounted root (ext2 filesystem). 2632 2633 bash# 2634 2635More About U-Boot Image Types: 2636------------------------------ 2637 2638U-Boot supports the following image types: 2639 2640 "Standalone Programs" are directly runnable in the environment 2641 provided by U-Boot; it is expected that (if they behave 2642 well) you can continue to work in U-Boot after return from 2643 the Standalone Program. 2644 "OS Kernel Images" are usually images of some Embedded OS which 2645 will take over control completely. Usually these programs 2646 will install their own set of exception handlers, device 2647 drivers, set up the MMU, etc. - this means, that you cannot 2648 expect to re-enter U-Boot except by resetting the CPU. 2649 "RAMDisk Images" are more or less just data blocks, and their 2650 parameters (address, size) are passed to an OS kernel that is 2651 being started. 2652 "Multi-File Images" contain several images, typically an OS 2653 (Linux) kernel image and one or more data images like 2654 RAMDisks. This construct is useful for instance when you want 2655 to boot over the network using BOOTP etc., where the boot 2656 server provides just a single image file, but you want to get 2657 for instance an OS kernel and a RAMDisk image. 2658 2659 "Multi-File Images" start with a list of image sizes, each 2660 image size (in bytes) specified by an "uint32_t" in network 2661 byte order. This list is terminated by an "(uint32_t)0". 2662 Immediately after the terminating 0 follow the images, one by 2663 one, all aligned on "uint32_t" boundaries (size rounded up to 2664 a multiple of 4 bytes). 2665 2666 "Firmware Images" are binary images containing firmware (like 2667 U-Boot or FPGA images) which usually will be programmed to 2668 flash memory. 2669 2670 "Script files" are command sequences that will be executed by 2671 U-Boot's command interpreter; this feature is especially 2672 useful when you configure U-Boot to use a real shell (hush) 2673 as command interpreter. 2674 2675 2676Standalone HOWTO: 2677================= 2678 2679One of the features of U-Boot is that you can dynamically load and 2680run "standalone" applications, which can use some resources of 2681U-Boot like console I/O functions or interrupt services. 2682 2683Two simple examples are included with the sources: 2684 2685"Hello World" Demo: 2686------------------- 2687 2688'examples/hello_world.c' contains a small "Hello World" Demo 2689application; it is automatically compiled when you build U-Boot. 2690It's configured to run at address 0x00040004, so you can play with it 2691like that: 2692 2693 => loads 2694 ## Ready for S-Record download ... 2695 ~>examples/hello_world.srec 2696 1 2 3 4 5 6 7 8 9 10 11 ... 2697 [file transfer complete] 2698 [connected] 2699 ## Start Addr = 0x00040004 2700 2701 => go 40004 Hello World! This is a test. 2702 ## Starting application at 0x00040004 ... 2703 Hello World 2704 argc = 7 2705 argv[0] = "40004" 2706 argv[1] = "Hello" 2707 argv[2] = "World!" 2708 argv[3] = "This" 2709 argv[4] = "is" 2710 argv[5] = "a" 2711 argv[6] = "test." 2712 argv[7] = "<NULL>" 2713 Hit any key to exit ... 2714 2715 ## Application terminated, rc = 0x0 2716 2717Another example, which demonstrates how to register a CPM interrupt 2718handler with the U-Boot code, can be found in 'examples/timer.c'. 2719Here, a CPM timer is set up to generate an interrupt every second. 2720The interrupt service routine is trivial, just printing a '.' 2721character, but this is just a demo program. The application can be 2722controlled by the following keys: 2723 2724 ? - print current values og the CPM Timer registers 2725 b - enable interrupts and start timer 2726 e - stop timer and disable interrupts 2727 q - quit application 2728 2729 => loads 2730 ## Ready for S-Record download ... 2731 ~>examples/timer.srec 2732 1 2 3 4 5 6 7 8 9 10 11 ... 2733 [file transfer complete] 2734 [connected] 2735 ## Start Addr = 0x00040004 2736 2737 => go 40004 2738 ## Starting application at 0x00040004 ... 2739 TIMERS=0xfff00980 2740 Using timer 1 2741 tgcr @ 0xfff00980, tmr @ 0xfff00990, trr @ 0xfff00994, tcr @ 0xfff00998, tcn @ 0xfff0099c, ter @ 0xfff009b0 2742 2743Hit 'b': 2744 [q, b, e, ?] Set interval 1000000 us 2745 Enabling timer 2746Hit '?': 2747 [q, b, e, ?] ........ 2748 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0xef6, ter=0x0 2749Hit '?': 2750 [q, b, e, ?] . 2751 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x2ad4, ter=0x0 2752Hit '?': 2753 [q, b, e, ?] . 2754 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x1efc, ter=0x0 2755Hit '?': 2756 [q, b, e, ?] . 2757 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x169d, ter=0x0 2758Hit 'e': 2759 [q, b, e, ?] ...Stopping timer 2760Hit 'q': 2761 [q, b, e, ?] ## Application terminated, rc = 0x0 2762 2763 2764Minicom warning: 2765================ 2766 2767Over time, many people have reported problems when trying to use the 2768"minicom" terminal emulation program for serial download. I (wd) 2769consider minicom to be broken, and recommend not to use it. Under 2770Unix, I recommend to use C-Kermit for general purpose use (and 2771especially for kermit binary protocol download ("loadb" command), and 2772use "cu" for S-Record download ("loads" command). 2773 2774Nevertheless, if you absolutely want to use it try adding this 2775configuration to your "File transfer protocols" section: 2776 2777 Name Program Name U/D FullScr IO-Red. Multi 2778 X kermit /usr/bin/kermit -i -l %l -s Y U Y N N 2779 Y kermit /usr/bin/kermit -i -l %l -r N D Y N N 2780 2781 2782NetBSD Notes: 2783============= 2784 2785Starting at version 0.9.2, U-Boot supports NetBSD both as host 2786(build U-Boot) and target system (boots NetBSD/mpc8xx). 2787 2788Building requires a cross environment; it is known to work on 2789NetBSD/i386 with the cross-powerpc-netbsd-1.3 package (you will also 2790need gmake since the Makefiles are not compatible with BSD make). 2791Note that the cross-powerpc package does not install include files; 2792attempting to build U-Boot will fail because <machine/ansi.h> is 2793missing. This file has to be installed and patched manually: 2794 2795 # cd /usr/pkg/cross/powerpc-netbsd/include 2796 # mkdir powerpc 2797 # ln -s powerpc machine 2798 # cp /usr/src/sys/arch/powerpc/include/ansi.h powerpc/ansi.h 2799 # ${EDIT} powerpc/ansi.h ## must remove __va_list, _BSD_VA_LIST 2800 2801Native builds *don't* work due to incompatibilities between native 2802and U-Boot include files. 2803 2804Booting assumes that (the first part of) the image booted is a 2805stage-2 loader which in turn loads and then invokes the kernel 2806proper. Loader sources will eventually appear in the NetBSD source 2807tree (probably in sys/arc/mpc8xx/stand/u-boot_stage2/); in the 2808meantime, send mail to bruno@exet-ag.de and/or wd@denx.de for 2809details. 2810 2811 2812Implementation Internals: 2813========================= 2814 2815The following is not intended to be a complete description of every 2816implementation detail. However, it should help to understand the 2817inner workings of U-Boot and make it easier to port it to custom 2818hardware. 2819 2820 2821Initial Stack, Global Data: 2822--------------------------- 2823 2824The implementation of U-Boot is complicated by the fact that U-Boot 2825starts running out of ROM (flash memory), usually without access to 2826system RAM (because the memory controller is not initialized yet). 2827This means that we don't have writable Data or BSS segments, and BSS 2828is not initialized as zero. To be able to get a C environment working 2829at all, we have to allocate at least a minimal stack. Implementation 2830options for this are defined and restricted by the CPU used: Some CPU 2831models provide on-chip memory (like the IMMR area on MPC8xx and 2832MPC826x processors), on others (parts of) the data cache can be 2833locked as (mis-) used as memory, etc. 2834 2835 Chris Hallinan posted a good summary of these issues to the 2836 u-boot-users mailing list: 2837 2838 Subject: RE: [U-Boot-Users] RE: More On Memory Bank x (nothingness)? 2839 From: "Chris Hallinan" <clh@net1plus.com> 2840 Date: Mon, 10 Feb 2003 16:43:46 -0500 (22:43 MET) 2841 ... 2842 2843 Correct me if I'm wrong, folks, but the way I understand it 2844 is this: Using DCACHE as initial RAM for Stack, etc, does not 2845 require any physical RAM backing up the cache. The cleverness 2846 is that the cache is being used as a temporary supply of 2847 necessary storage before the SDRAM controller is setup. It's 2848 beyond the scope of this list to expain the details, but you 2849 can see how this works by studying the cache architecture and 2850 operation in the architecture and processor-specific manuals. 2851 2852 OCM is On Chip Memory, which I believe the 405GP has 4K. It 2853 is another option for the system designer to use as an 2854 initial stack/ram area prior to SDRAM being available. Either 2855 option should work for you. Using CS 4 should be fine if your 2856 board designers haven't used it for something that would 2857 cause you grief during the initial boot! It is frequently not 2858 used. 2859 2860 CFG_INIT_RAM_ADDR should be somewhere that won't interfere 2861 with your processor/board/system design. The default value 2862 you will find in any recent u-boot distribution in 2863 Walnut405.h should work for you. I'd set it to a value larger 2864 than your SDRAM module. If you have a 64MB SDRAM module, set 2865 it above 400_0000. Just make sure your board has no resources 2866 that are supposed to respond to that address! That code in 2867 start.S has been around a while and should work as is when 2868 you get the config right. 2869 2870 -Chris Hallinan 2871 DS4.COM, Inc. 2872 2873It is essential to remember this, since it has some impact on the C 2874code for the initialization procedures: 2875 2876* Initialized global data (data segment) is read-only. Do not attempt 2877 to write it. 2878 2879* Do not use any unitialized global data (or implicitely initialized 2880 as zero data - BSS segment) at all - this is undefined, initiali- 2881 zation is performed later (when relocating to RAM). 2882 2883* Stack space is very limited. Avoid big data buffers or things like 2884 that. 2885 2886Having only the stack as writable memory limits means we cannot use 2887normal global data to share information beween the code. But it 2888turned out that the implementation of U-Boot can be greatly 2889simplified by making a global data structure (gd_t) available to all 2890functions. We could pass a pointer to this data as argument to _all_ 2891functions, but this would bloat the code. Instead we use a feature of 2892the GCC compiler (Global Register Variables) to share the data: we 2893place a pointer (gd) to the global data into a register which we 2894reserve for this purpose. 2895 2896When choosing a register for such a purpose we are restricted by the 2897relevant (E)ABI specifications for the current architecture, and by 2898GCC's implementation. 2899 2900For PowerPC, the following registers have specific use: 2901 R1: stack pointer 2902 R2: TOC pointer 2903 R3-R4: parameter passing and return values 2904 R5-R10: parameter passing 2905 R13: small data area pointer 2906 R30: GOT pointer 2907 R31: frame pointer 2908 2909 (U-Boot also uses R14 as internal GOT pointer.) 2910 2911 ==> U-Boot will use R29 to hold a pointer to the global data 2912 2913 Note: on PPC, we could use a static initializer (since the 2914 address of the global data structure is known at compile time), 2915 but it turned out that reserving a register results in somewhat 2916 smaller code - although the code savings are not that big (on 2917 average for all boards 752 bytes for the whole U-Boot image, 2918 624 text + 127 data). 2919 2920On ARM, the following registers are used: 2921 2922 R0: function argument word/integer result 2923 R1-R3: function argument word 2924 R9: GOT pointer 2925 R10: stack limit (used only if stack checking if enabled) 2926 R11: argument (frame) pointer 2927 R12: temporary workspace 2928 R13: stack pointer 2929 R14: link register 2930 R15: program counter 2931 2932 ==> U-Boot will use R8 to hold a pointer to the global data 2933 2934 2935Memory Management: 2936------------------ 2937 2938U-Boot runs in system state and uses physical addresses, i.e. the 2939MMU is not used either for address mapping nor for memory protection. 2940 2941The available memory is mapped to fixed addresses using the memory 2942controller. In this process, a contiguous block is formed for each 2943memory type (Flash, SDRAM, SRAM), even when it consists of several 2944physical memory banks. 2945 2946U-Boot is installed in the first 128 kB of the first Flash bank (on 2947TQM8xxL modules this is the range 0x40000000 ... 0x4001FFFF). After 2948booting and sizing and initializing DRAM, the code relocates itself 2949to the upper end of DRAM. Immediately below the U-Boot code some 2950memory is reserved for use by malloc() [see CFG_MALLOC_LEN 2951configuration setting]. Below that, a structure with global Board 2952Info data is placed, followed by the stack (growing downward). 2953 2954Additionally, some exception handler code is copied to the low 8 kB 2955of DRAM (0x00000000 ... 0x00001FFF). 2956 2957So a typical memory configuration with 16 MB of DRAM could look like 2958this: 2959 2960 0x0000 0000 Exception Vector code 2961 : 2962 0x0000 1FFF 2963 0x0000 2000 Free for Application Use 2964 : 2965 : 2966 2967 : 2968 : 2969 0x00FB FF20 Monitor Stack (Growing downward) 2970 0x00FB FFAC Board Info Data and permanent copy of global data 2971 0x00FC 0000 Malloc Arena 2972 : 2973 0x00FD FFFF 2974 0x00FE 0000 RAM Copy of Monitor Code 2975 ... eventually: LCD or video framebuffer 2976 ... eventually: pRAM (Protected RAM - unchanged by reset) 2977 0x00FF FFFF [End of RAM] 2978 2979 2980System Initialization: 2981---------------------- 2982 2983In the reset configuration, U-Boot starts at the reset entry point 2984(on most PowerPC systens at address 0x00000100). Because of the reset 2985configuration for CS0# this is a mirror of the onboard Flash memory. 2986To be able to re-map memory U-Boot then jumps to its link address. 2987To be able to implement the initialization code in C, a (small!) 2988initial stack is set up in the internal Dual Ported RAM (in case CPUs 2989which provide such a feature like MPC8xx or MPC8260), or in a locked 2990part of the data cache. After that, U-Boot initializes the CPU core, 2991the caches and the SIU. 2992 2993Next, all (potentially) available memory banks are mapped using a 2994preliminary mapping. For example, we put them on 512 MB boundaries 2995(multiples of 0x20000000: SDRAM on 0x00000000 and 0x20000000, Flash 2996on 0x40000000 and 0x60000000, SRAM on 0x80000000). Then UPM A is 2997programmed for SDRAM access. Using the temporary configuration, a 2998simple memory test is run that determines the size of the SDRAM 2999banks. 3000 3001When there is more than one SDRAM bank, and the banks are of 3002different size, the largest is mapped first. For equal size, the first 3003bank (CS2#) is mapped first. The first mapping is always for address 30040x00000000, with any additional banks following immediately to create 3005contiguous memory starting from 0. 3006 3007Then, the monitor installs itself at the upper end of the SDRAM area 3008and allocates memory for use by malloc() and for the global Board 3009Info data; also, the exception vector code is copied to the low RAM 3010pages, and the final stack is set up. 3011 3012Only after this relocation will you have a "normal" C environment; 3013until that you are restricted in several ways, mostly because you are 3014running from ROM, and because the code will have to be relocated to a 3015new address in RAM. 3016 3017 3018U-Boot Porting Guide: 3019---------------------- 3020 3021[Based on messages by Jerry Van Baren in the U-Boot-Users mailing 3022list, October 2002] 3023 3024 3025int main (int argc, char *argv[]) 3026{ 3027 sighandler_t no_more_time; 3028 3029 signal (SIGALRM, no_more_time); 3030 alarm (PROJECT_DEADLINE - toSec (3 * WEEK)); 3031 3032 if (available_money > available_manpower) { 3033 pay consultant to port U-Boot; 3034 return 0; 3035 } 3036 3037 Download latest U-Boot source; 3038 3039 Subscribe to u-boot-users mailing list; 3040 3041 if (clueless) { 3042 email ("Hi, I am new to U-Boot, how do I get started?"); 3043 } 3044 3045 while (learning) { 3046 Read the README file in the top level directory; 3047 Read http://www.denx.de/re/DPLG.html 3048 Read the source, Luke; 3049 } 3050 3051 if (available_money > toLocalCurrency ($2500)) { 3052 Buy a BDI2000; 3053 } else { 3054 Add a lot of aggravation and time; 3055 } 3056 3057 Create your own board support subdirectory; 3058 3059 Create your own board config file; 3060 3061 while (!running) { 3062 do { 3063 Add / modify source code; 3064 } until (compiles); 3065 Debug; 3066 if (clueless) 3067 email ("Hi, I am having problems..."); 3068 } 3069 Send patch file to Wolfgang; 3070 3071 return 0; 3072} 3073 3074void no_more_time (int sig) 3075{ 3076 hire_a_guru(); 3077} 3078 3079 3080Coding Standards: 3081----------------- 3082 3083All contributions to U-Boot should conform to the Linux kernel 3084coding style; see the file "Documentation/CodingStyle" in your Linux 3085kernel source directory. 3086 3087Please note that U-Boot is implemented in C (and to some small parts 3088in Assembler); no C++ is used, so please do not use C++ style 3089comments (//) in your code. 3090 3091Submissions which do not conform to the standards may be returned 3092with a request to reformat the changes. 3093 3094 3095Submitting Patches: 3096------------------- 3097 3098Since the number of patches for U-Boot is growing, we need to 3099establish some rules. Submissions which do not conform to these rules 3100may be rejected, even when they contain important and valuable stuff. 3101 3102 3103When you send a patch, please include the following information with 3104it: 3105 3106* For bug fixes: a description of the bug and how your patch fixes 3107 this bug. Please try to include a way of demonstrating that the 3108 patch actually fixes something. 3109 3110* For new features: a description of the feature and your 3111 implementation. 3112 3113* A CHANGELOG entry as plaintext (separate from the patch) 3114 3115* For major contributions, your entry to the CREDITS file 3116 3117* When you add support for a new board, don't forget to add this 3118 board to the MAKEALL script, too. 3119 3120* If your patch adds new configuration options, don't forget to 3121 document these in the README file. 3122 3123* The patch itself. If you are accessing the CVS repository use "cvs 3124 update; cvs diff -puRN"; else, use "diff -purN OLD NEW". If your 3125 version of diff does not support these options, then get the latest 3126 version of GNU diff. 3127 3128 The current directory when running this command shall be the top 3129 level directory of the U-Boot source tree, or it's parent directory 3130 (i. e. please make sure that your patch includes sufficient 3131 directory information for the affected files). 3132 3133 We accept patches as plain text, MIME attachments or as uuencoded 3134 gzipped text. 3135 3136* If one logical set of modifications affects or creates several 3137 files, all these changes shall be submitted in a SINGLE patch file. 3138 3139* Changesets that contain different, unrelated modifications shall be 3140 submitted as SEPARATE patches, one patch per changeset. 3141 3142 3143Notes: 3144 3145* Before sending the patch, run the MAKEALL script on your patched 3146 source tree and make sure that no errors or warnings are reported 3147 for any of the boards. 3148 3149* Keep your modifications to the necessary minimum: A patch 3150 containing several unrelated changes or arbitrary reformats will be 3151 returned with a request to re-formatting / split it. 3152 3153* If you modify existing code, make sure that your new code does not 3154 add to the memory footprint of the code ;-) Small is beautiful! 3155 When adding new features, these should compile conditionally only 3156 (using #ifdef), and the resulting code with the new feature 3157 disabled must not need more memory than the old code without your 3158 modification. 3159