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- board/zpc1900 Files specific to Zephyr Engineering ZPC.1900 board 243 244Software Configuration: 245======================= 246 247Configuration is usually done using C preprocessor defines; the 248rationale behind that is to avoid dead code whenever possible. 249 250There are two classes of configuration variables: 251 252* Configuration _OPTIONS_: 253 These are selectable by the user and have names beginning with 254 "CONFIG_". 255 256* Configuration _SETTINGS_: 257 These depend on the hardware etc. and should not be meddled with if 258 you don't know what you're doing; they have names beginning with 259 "CFG_". 260 261Later we will add a configuration tool - probably similar to or even 262identical to what's used for the Linux kernel. Right now, we have to 263do the configuration by hand, which means creating some symbolic 264links and editing some configuration files. We use the TQM8xxL boards 265as an example here. 266 267 268Selection of Processor Architecture and Board Type: 269--------------------------------------------------- 270 271For all supported boards there are ready-to-use default 272configurations available; just type "make <board_name>_config". 273 274Example: For a TQM823L module type: 275 276 cd u-boot 277 make TQM823L_config 278 279For the Cogent platform, you need to specify the cpu type as well; 280e.g. "make cogent_mpc8xx_config". And also configure the cogent 281directory according to the instructions in cogent/README. 282 283 284Configuration Options: 285---------------------- 286 287Configuration depends on the combination of board and CPU type; all 288such information is kept in a configuration file 289"include/configs/<board_name>.h". 290 291Example: For a TQM823L module, all configuration settings are in 292"include/configs/TQM823L.h". 293 294 295Many of the options are named exactly as the corresponding Linux 296kernel configuration options. The intention is to make it easier to 297build a config tool - later. 298 299 300The following options need to be configured: 301 302- CPU Type: Define exactly one of 303 304 PowerPC based CPUs: 305 ------------------- 306 CONFIG_MPC823, CONFIG_MPC850, CONFIG_MPC855, CONFIG_MPC860 307 or CONFIG_MPC5xx 308 or CONFIG_MPC824X, CONFIG_MPC8260 309 or CONFIG_IOP480 310 or CONFIG_405GP 311 or CONFIG_405EP 312 or CONFIG_440 313 or CONFIG_MPC74xx 314 or CONFIG_750FX 315 316 ARM based CPUs: 317 --------------- 318 CONFIG_SA1110 319 CONFIG_ARM7 320 CONFIG_PXA250 321 322 323- Board Type: Define exactly one of 324 325 PowerPC based boards: 326 --------------------- 327 328 CONFIG_ADCIOP, CONFIG_ICU862 CONFIG_RPXsuper, 329 CONFIG_ADS860, CONFIG_IP860, CONFIG_SM850, 330 CONFIG_AMX860, CONFIG_IPHASE4539, CONFIG_SPD823TS, 331 CONFIG_AR405, CONFIG_IVML24, CONFIG_SXNI855T, 332 CONFIG_BAB7xx, CONFIG_IVML24_128, CONFIG_Sandpoint8240, 333 CONFIG_CANBT, CONFIG_IVML24_256, CONFIG_Sandpoint8245, 334 CONFIG_CCM, CONFIG_IVMS8, CONFIG_TQM823L, 335 CONFIG_CPCI405, CONFIG_IVMS8_128, CONFIG_TQM850L, 336 CONFIG_CPCI4052, CONFIG_IVMS8_256, CONFIG_TQM855L, 337 CONFIG_CPCIISER4, CONFIG_LANTEC, CONFIG_TQM860L, 338 CONFIG_CPU86, CONFIG_MBX, CONFIG_TQM8260, 339 CONFIG_CRAYL1, CONFIG_MBX860T, CONFIG_TTTech, 340 CONFIG_CU824, CONFIG_MHPC, CONFIG_UTX8245, 341 CONFIG_DASA_SIM, CONFIG_MIP405, CONFIG_W7OLMC, 342 CONFIG_DU405, CONFIG_MOUSSE, CONFIG_W7OLMG, 343 CONFIG_ELPPC, CONFIG_MPC8260ADS, CONFIG_WALNUT405, 344 CONFIG_ERIC, CONFIG_MUSENKI, CONFIG_ZUMA, 345 CONFIG_ESTEEM192E, CONFIG_MVS1, CONFIG_c2mon, 346 CONFIG_ETX094, CONFIG_NX823, CONFIG_cogent_mpc8260, 347 CONFIG_EVB64260, CONFIG_OCRTC, CONFIG_cogent_mpc8xx, 348 CONFIG_FADS823, CONFIG_ORSG, CONFIG_ep8260, 349 CONFIG_FADS850SAR, CONFIG_OXC, CONFIG_gw8260, 350 CONFIG_FADS860T, CONFIG_PCI405, CONFIG_hermes, 351 CONFIG_FLAGADM, CONFIG_PCIPPC2, CONFIG_hymod, 352 CONFIG_FPS850L, CONFIG_PCIPPC6, CONFIG_lwmon, 353 CONFIG_GEN860T, CONFIG_PIP405, CONFIG_pcu_e, 354 CONFIG_GENIETV, CONFIG_PM826, CONFIG_ppmc8260, 355 CONFIG_GTH, CONFIG_RPXClassic, CONFIG_rsdproto, 356 CONFIG_IAD210, CONFIG_RPXlite, CONFIG_sbc8260, 357 CONFIG_EBONY, CONFIG_sacsng, CONFIG_FPS860L, 358 CONFIG_V37, CONFIG_ELPT860, CONFIG_CMI, 359 CONFIG_NETVIA, CONFIG_RBC823, CONFIG_ZPC1900 360 361 ARM based boards: 362 ----------------- 363 364 CONFIG_HHP_CRADLE, CONFIG_DNP1110, CONFIG_EP7312, 365 CONFIG_IMPA7, CONFIG_LART, CONFIG_LUBBOCK, 366 CONFIG_INNOVATOROMAP1510, CONFIG_INNOVATOROMAP1610 367 CONFIG_SHANNON, CONFIG_SMDK2400, CONFIG_SMDK2410, 368 CONFIG_TRAB, CONFIG_VCMA9, CONFIG_AT91RM9200DK 369 370 371- CPU Module Type: (if CONFIG_COGENT is defined) 372 Define exactly one of 373 CONFIG_CMA286_60_OLD 374--- FIXME --- not tested yet: 375 CONFIG_CMA286_60, CONFIG_CMA286_21, CONFIG_CMA286_60P, 376 CONFIG_CMA287_23, CONFIG_CMA287_50 377 378- Motherboard Type: (if CONFIG_COGENT is defined) 379 Define exactly one of 380 CONFIG_CMA101, CONFIG_CMA102 381 382- Motherboard I/O Modules: (if CONFIG_COGENT is defined) 383 Define one or more of 384 CONFIG_CMA302 385 386- Motherboard Options: (if CONFIG_CMA101 or CONFIG_CMA102 are defined) 387 Define one or more of 388 CONFIG_LCD_HEARTBEAT - update a character position on 389 the lcd display every second with 390 a "rotator" |\-/|\-/ 391 392- Board flavour: (if CONFIG_MPC8260ADS is defined) 393 CONFIG_ADSTYPE 394 Possible values are: 395 CFG_8260ADS - original MPC8260ADS 396 CFG_8266ADS - MPC8266ADS (untested) 397 CFG_PQ2FADS - PQ2FADS-ZU or PQ2FADS-VR 398 399 400- MPC824X Family Member (if CONFIG_MPC824X is defined) 401 Define exactly one of 402 CONFIG_MPC8240, CONFIG_MPC8245 403 404- 8xx CPU Options: (if using an 8xx cpu) 405 Define one or more of 406 CONFIG_8xx_GCLK_FREQ - if get_gclk_freq() can not work e.g. 407 no 32KHz reference PIT/RTC clock 408 409- Clock Interface: 410 CONFIG_CLOCKS_IN_MHZ 411 412 U-Boot stores all clock information in Hz 413 internally. For binary compatibility with older Linux 414 kernels (which expect the clocks passed in the 415 bd_info data to be in MHz) the environment variable 416 "clocks_in_mhz" can be defined so that U-Boot 417 converts clock data to MHZ before passing it to the 418 Linux kernel. 419 420 When CONFIG_CLOCKS_IN_MHZ is defined, a definition of 421 "clocks_in_mhz=1" is automatically included in the 422 default environment. 423 424- Console Interface: 425 Depending on board, define exactly one serial port 426 (like CONFIG_8xx_CONS_SMC1, CONFIG_8xx_CONS_SMC2, 427 CONFIG_8xx_CONS_SCC1, ...), or switch off the serial 428 console by defining CONFIG_8xx_CONS_NONE 429 430 Note: if CONFIG_8xx_CONS_NONE is defined, the serial 431 port routines must be defined elsewhere 432 (i.e. serial_init(), serial_getc(), ...) 433 434 CONFIG_CFB_CONSOLE 435 Enables console device for a color framebuffer. Needs following 436 defines (cf. smiLynxEM, i8042, board/eltec/bab7xx) 437 VIDEO_FB_LITTLE_ENDIAN graphic memory organisation 438 (default big endian) 439 VIDEO_HW_RECTFILL graphic chip supports 440 rectangle fill 441 (cf. smiLynxEM) 442 VIDEO_HW_BITBLT graphic chip supports 443 bit-blit (cf. smiLynxEM) 444 VIDEO_VISIBLE_COLS visible pixel columns 445 (cols=pitch) 446 VIDEO_VISIBLE_ROWS visible pixel rows 447 VIDEO_PIXEL_SIZE bytes per pixel 448 VIDEO_DATA_FORMAT graphic data format 449 (0-5, cf. cfb_console.c) 450 VIDEO_FB_ADRS framebuffer address 451 VIDEO_KBD_INIT_FCT keyboard int fct 452 (i.e. i8042_kbd_init()) 453 VIDEO_TSTC_FCT test char fct 454 (i.e. i8042_tstc) 455 VIDEO_GETC_FCT get char fct 456 (i.e. i8042_getc) 457 CONFIG_CONSOLE_CURSOR cursor drawing on/off 458 (requires blink timer 459 cf. i8042.c) 460 CFG_CONSOLE_BLINK_COUNT blink interval (cf. i8042.c) 461 CONFIG_CONSOLE_TIME display time/date info in 462 upper right corner 463 (requires CFG_CMD_DATE) 464 CONFIG_VIDEO_LOGO display Linux logo in 465 upper left corner 466 CONFIG_VIDEO_BMP_LOGO use bmp_logo.h instead of 467 linux_logo.h for logo. 468 Requires CONFIG_VIDEO_LOGO 469 CONFIG_CONSOLE_EXTRA_INFO 470 addional board info beside 471 the logo 472 473 When CONFIG_CFB_CONSOLE is defined, video console is 474 default i/o. Serial console can be forced with 475 environment 'console=serial'. 476 477- Console Baudrate: 478 CONFIG_BAUDRATE - in bps 479 Select one of the baudrates listed in 480 CFG_BAUDRATE_TABLE, see below. 481 482- Interrupt driven serial port input: 483 CONFIG_SERIAL_SOFTWARE_FIFO 484 485 PPC405GP only. 486 Use an interrupt handler for receiving data on the 487 serial port. It also enables using hardware handshake 488 (RTS/CTS) and UART's built-in FIFO. Set the number of 489 bytes the interrupt driven input buffer should have. 490 491 Set to 0 to disable this feature (this is the default). 492 This will also disable hardware handshake. 493 494- Console UART Number: 495 CONFIG_UART1_CONSOLE 496 497 IBM PPC4xx only. 498 If defined internal UART1 (and not UART0) is used 499 as default U-Boot console. 500 501- Boot Delay: CONFIG_BOOTDELAY - in seconds 502 Delay before automatically booting the default image; 503 set to -1 to disable autoboot. 504 505 See doc/README.autoboot for these options that 506 work with CONFIG_BOOTDELAY. None are required. 507 CONFIG_BOOT_RETRY_TIME 508 CONFIG_BOOT_RETRY_MIN 509 CONFIG_AUTOBOOT_KEYED 510 CONFIG_AUTOBOOT_PROMPT 511 CONFIG_AUTOBOOT_DELAY_STR 512 CONFIG_AUTOBOOT_STOP_STR 513 CONFIG_AUTOBOOT_DELAY_STR2 514 CONFIG_AUTOBOOT_STOP_STR2 515 CONFIG_ZERO_BOOTDELAY_CHECK 516 CONFIG_RESET_TO_RETRY 517 518- Autoboot Command: 519 CONFIG_BOOTCOMMAND 520 Only needed when CONFIG_BOOTDELAY is enabled; 521 define a command string that is automatically executed 522 when no character is read on the console interface 523 within "Boot Delay" after reset. 524 525 CONFIG_BOOTARGS 526 This can be used to pass arguments to the bootm 527 command. The value of CONFIG_BOOTARGS goes into the 528 environment value "bootargs". 529 530 CONFIG_RAMBOOT and CONFIG_NFSBOOT 531 The value of these goes into the environment as 532 "ramboot" and "nfsboot" respectively, and can be used 533 as a convenience, when switching between booting from 534 ram and nfs. 535 536- Pre-Boot Commands: 537 CONFIG_PREBOOT 538 539 When this option is #defined, the existence of the 540 environment variable "preboot" will be checked 541 immediately before starting the CONFIG_BOOTDELAY 542 countdown and/or running the auto-boot command resp. 543 entering interactive mode. 544 545 This feature is especially useful when "preboot" is 546 automatically generated or modified. For an example 547 see the LWMON board specific code: here "preboot" is 548 modified when the user holds down a certain 549 combination of keys on the (special) keyboard when 550 booting the systems 551 552- Serial Download Echo Mode: 553 CONFIG_LOADS_ECHO 554 If defined to 1, all characters received during a 555 serial download (using the "loads" command) are 556 echoed back. This might be needed by some terminal 557 emulations (like "cu"), but may as well just take 558 time on others. This setting #define's the initial 559 value of the "loads_echo" environment variable. 560 561- Kgdb Serial Baudrate: (if CFG_CMD_KGDB is defined) 562 CONFIG_KGDB_BAUDRATE 563 Select one of the baudrates listed in 564 CFG_BAUDRATE_TABLE, see below. 565 566- Monitor Functions: 567 CONFIG_COMMANDS 568 Most monitor functions can be selected (or 569 de-selected) by adjusting the definition of 570 CONFIG_COMMANDS; to select individual functions, 571 #define CONFIG_COMMANDS by "OR"ing any of the 572 following values: 573 574 #define enables commands: 575 ------------------------- 576 CFG_CMD_ASKENV * ask for env variable 577 CFG_CMD_AUTOSCRIPT Autoscript Support 578 CFG_CMD_BDI bdinfo 579 CFG_CMD_BEDBUG Include BedBug Debugger 580 CFG_CMD_BMP * BMP support 581 CFG_CMD_BOOTD bootd 582 CFG_CMD_CACHE icache, dcache 583 CFG_CMD_CONSOLE coninfo 584 CFG_CMD_DATE * support for RTC, date/time... 585 CFG_CMD_DHCP DHCP support 586 CFG_CMD_DIAG * Diagnostics 587 CFG_CMD_DOC * Disk-On-Chip Support 588 CFG_CMD_DTT Digital Therm and Thermostat 589 CFG_CMD_ECHO * echo arguments 590 CFG_CMD_EEPROM * EEPROM read/write support 591 CFG_CMD_ELF bootelf, bootvx 592 CFG_CMD_ENV saveenv 593 CFG_CMD_FDC * Floppy Disk Support 594 CFG_CMD_FAT FAT partition support 595 CFG_CMD_FDOS * Dos diskette Support 596 CFG_CMD_FLASH flinfo, erase, protect 597 CFG_CMD_FPGA FPGA device initialization support 598 CFG_CMD_HWFLOW * RTS/CTS hw flow control 599 CFG_CMD_I2C * I2C serial bus support 600 CFG_CMD_IDE * IDE harddisk support 601 CFG_CMD_IMI iminfo 602 CFG_CMD_IMLS List all found images 603 CFG_CMD_IMMAP * IMMR dump support 604 CFG_CMD_IRQ * irqinfo 605 CFG_CMD_JFFS2 * JFFS2 Support 606 CFG_CMD_KGDB * kgdb 607 CFG_CMD_LOADB loadb 608 CFG_CMD_LOADS loads 609 CFG_CMD_MEMORY md, mm, nm, mw, cp, cmp, crc, base, 610 loop, mtest 611 CFG_CMD_MISC Misc functions like sleep etc 612 CFG_CMD_MMC MMC memory mapped support 613 CFG_CMD_MII MII utility commands 614 CFG_CMD_NAND * NAND support 615 CFG_CMD_NET bootp, tftpboot, rarpboot 616 CFG_CMD_PCI * pciinfo 617 CFG_CMD_PCMCIA * PCMCIA support 618 CFG_CMD_PING * send ICMP ECHO_REQUEST to network host 619 CFG_CMD_PORTIO Port I/O 620 CFG_CMD_REGINFO * Register dump 621 CFG_CMD_RUN run command in env variable 622 CFG_CMD_SAVES save S record dump 623 CFG_CMD_SCSI * SCSI Support 624 CFG_CMD_SDRAM * print SDRAM configuration information 625 CFG_CMD_SETGETDCR Support for DCR Register access (4xx only) 626 CFG_CMD_SPI * SPI serial bus support 627 CFG_CMD_USB * USB support 628 CFG_CMD_VFD * VFD support (TRAB) 629 CFG_CMD_BSP * Board SPecific functions 630 ----------------------------------------------- 631 CFG_CMD_ALL all 632 633 CFG_CMD_DFL Default configuration; at the moment 634 this is includes all commands, except 635 the ones marked with "*" in the list 636 above. 637 638 If you don't define CONFIG_COMMANDS it defaults to 639 CFG_CMD_DFL in include/cmd_confdefs.h. A board can 640 override the default settings in the respective 641 include file. 642 643 EXAMPLE: If you want all functions except of network 644 support you can write: 645 646 #define CONFIG_COMMANDS (CFG_CMD_ALL & ~CFG_CMD_NET) 647 648 649 Note: Don't enable the "icache" and "dcache" commands 650 (configuration option CFG_CMD_CACHE) unless you know 651 what you (and your U-Boot users) are doing. Data 652 cache cannot be enabled on systems like the 8xx or 653 8260 (where accesses to the IMMR region must be 654 uncached), and it cannot be disabled on all other 655 systems where we (mis-) use the data cache to hold an 656 initial stack and some data. 657 658 659 XXX - this list needs to get updated! 660 661- Watchdog: 662 CONFIG_WATCHDOG 663 If this variable is defined, it enables watchdog 664 support. There must be support in the platform specific 665 code for a watchdog. For the 8xx and 8260 CPUs, the 666 SIU Watchdog feature is enabled in the SYPCR 667 register. 668 669- U-Boot Version: 670 CONFIG_VERSION_VARIABLE 671 If this variable is defined, an environment variable 672 named "ver" is created by U-Boot showing the U-Boot 673 version as printed by the "version" command. 674 This variable is readonly. 675 676- Real-Time Clock: 677 678 When CFG_CMD_DATE is selected, the type of the RTC 679 has to be selected, too. Define exactly one of the 680 following options: 681 682 CONFIG_RTC_MPC8xx - use internal RTC of MPC8xx 683 CONFIG_RTC_PCF8563 - use Philips PCF8563 RTC 684 CONFIG_RTC_MC146818 - use MC146818 RTC 685 CONFIG_RTC_DS1307 - use Maxim, Inc. DS1307 RTC 686 CONFIG_RTC_DS1337 - use Maxim, Inc. DS1337 RTC 687 CONFIG_RTC_DS1338 - use Maxim, Inc. DS1338 RTC 688 CONFIG_RTC_DS164x - use Dallas DS164x RTC 689 690 Note that if the RTC uses I2C, then the I2C interface 691 must also be configured. See I2C Support, below. 692 693- Timestamp Support: 694 695 When CONFIG_TIMESTAMP is selected, the timestamp 696 (date and time) of an image is printed by image 697 commands like bootm or iminfo. This option is 698 automatically enabled when you select CFG_CMD_DATE . 699 700- Partition Support: 701 CONFIG_MAC_PARTITION and/or CONFIG_DOS_PARTITION 702 and/or CONFIG_ISO_PARTITION 703 704 If IDE or SCSI support is enabled (CFG_CMD_IDE or 705 CFG_CMD_SCSI) you must configure support for at least 706 one partition type as well. 707 708- IDE Reset method: 709 CONFIG_IDE_RESET_ROUTINE 710 711 Set this to define that instead of a reset Pin, the 712 routine ide_set_reset(int idereset) will be used. 713 714- ATAPI Support: 715 CONFIG_ATAPI 716 717 Set this to enable ATAPI support. 718 719- SCSI Support: 720 At the moment only there is only support for the 721 SYM53C8XX SCSI controller; define 722 CONFIG_SCSI_SYM53C8XX to enable it. 723 724 CFG_SCSI_MAX_LUN [8], CFG_SCSI_MAX_SCSI_ID [7] and 725 CFG_SCSI_MAX_DEVICE [CFG_SCSI_MAX_SCSI_ID * 726 CFG_SCSI_MAX_LUN] can be adjusted to define the 727 maximum numbers of LUNs, SCSI ID's and target 728 devices. 729 CFG_SCSI_SYM53C8XX_CCF to fix clock timing (80Mhz) 730 731- NETWORK Support (PCI): 732 CONFIG_E1000 733 Support for Intel 8254x gigabit chips. 734 735 CONFIG_EEPRO100 736 Support for Intel 82557/82559/82559ER chips. 737 Optional CONFIG_EEPRO100_SROM_WRITE enables eeprom 738 write routine for first time initialisation. 739 740 CONFIG_TULIP 741 Support for Digital 2114x chips. 742 Optional CONFIG_TULIP_SELECT_MEDIA for board specific 743 modem chip initialisation (KS8761/QS6611). 744 745 CONFIG_NATSEMI 746 Support for National dp83815 chips. 747 748 CONFIG_NS8382X 749 Support for National dp8382[01] gigabit chips. 750 751- NETWORK Support (other): 752 753 CONFIG_DRIVER_LAN91C96 754 Support for SMSC's LAN91C96 chips. 755 756 CONFIG_LAN91C96_BASE 757 Define this to hold the physical address 758 of the LAN91C96's I/O space 759 760 CONFIG_LAN91C96_USE_32_BIT 761 Define this to enable 32 bit addressing 762 763- USB Support: 764 At the moment only the UHCI host controller is 765 supported (PIP405, MIP405); define 766 CONFIG_USB_UHCI to enable it. 767 define CONFIG_USB_KEYBOARD to enable the USB Keyboard 768 end define CONFIG_USB_STORAGE to enable the USB 769 storage devices. 770 Note: 771 Supported are USB Keyboards and USB Floppy drives 772 (TEAC FD-05PUB). 773 774- MMC Support: 775 The MMC controller on the Intel PXA is supported. To 776 enable this define CONFIG_MMC. The MMC can be 777 accessed from the boot prompt by mapping the device 778 to physical memory similar to flash. Command line is 779 enabled with CFG_CMD_MMC. The MMC driver also works with 780 the FAT fs. This is enabled with CFG_CMD_FAT. 781 782- Keyboard Support: 783 CONFIG_ISA_KEYBOARD 784 785 Define this to enable standard (PC-Style) keyboard 786 support 787 788 CONFIG_I8042_KBD 789 Standard PC keyboard driver with US (is default) and 790 GERMAN key layout (switch via environment 'keymap=de') support. 791 Export function i8042_kbd_init, i8042_tstc and i8042_getc 792 for cfb_console. Supports cursor blinking. 793 794- Video support: 795 CONFIG_VIDEO 796 797 Define this to enable video support (for output to 798 video). 799 800 CONFIG_VIDEO_CT69000 801 802 Enable Chips & Technologies 69000 Video chip 803 804 CONFIG_VIDEO_SMI_LYNXEM 805 Enable Silicon Motion SMI 712/710/810 Video chip 806 Videomode are selected via environment 'videomode' with 807 standard LiLo mode numbers. 808 Following modes are supported (* is default): 809 810 800x600 1024x768 1280x1024 811 256 (8bit) 303* 305 307 812 65536 (16bit) 314 317 31a 813 16,7 Mill (24bit) 315 318 31b 814 (i.e. setenv videomode 317; saveenv; reset;) 815 816 CONFIG_VIDEO_SED13806 817 Enable Epson SED13806 driver. This driver supports 8bpp 818 and 16bpp modes defined by CONFIG_VIDEO_SED13806_8BPP 819 or CONFIG_VIDEO_SED13806_16BPP 820 821- Keyboard Support: 822 CONFIG_KEYBOARD 823 824 Define this to enable a custom keyboard support. 825 This simply calls drv_keyboard_init() which must be 826 defined in your board-specific files. 827 The only board using this so far is RBC823. 828 829- LCD Support: CONFIG_LCD 830 831 Define this to enable LCD support (for output to LCD 832 display); also select one of the supported displays 833 by defining one of these: 834 835 CONFIG_NEC_NL6648AC33: 836 837 NEC NL6648AC33-18. Active, color, single scan. 838 839 CONFIG_NEC_NL6648BC20 840 841 NEC NL6648BC20-08. 6.5", 640x480. 842 Active, color, single scan. 843 844 CONFIG_SHARP_16x9 845 846 Sharp 320x240. Active, color, single scan. 847 It isn't 16x9, and I am not sure what it is. 848 849 CONFIG_SHARP_LQ64D341 850 851 Sharp LQ64D341 display, 640x480. 852 Active, color, single scan. 853 854 CONFIG_HLD1045 855 856 HLD1045 display, 640x480. 857 Active, color, single scan. 858 859 CONFIG_OPTREX_BW 860 861 Optrex CBL50840-2 NF-FW 99 22 M5 862 or 863 Hitachi LMG6912RPFC-00T 864 or 865 Hitachi SP14Q002 866 867 320x240. Black & white. 868 869 Normally display is black on white background; define 870 CFG_WHITE_ON_BLACK to get it inverted. 871 872- Splash Screen Support: CONFIG_SPLASH_SCREEN 873 874 If this option is set, the environment is checked for 875 a variable "splashimage". If found, the usual display 876 of logo, copyright and system information on the LCD 877 is supressed and the BMP image at the address 878 specified in "splashimage" is loaded instead. The 879 console is redirected to the "nulldev", too. This 880 allows for a "silent" boot where a splash screen is 881 loaded very quickly after power-on. 882 883- Compression support: 884 CONFIG_BZIP2 885 886 If this option is set, support for bzip2 compressed 887 images is included. If not, only uncompressed and gzip 888 compressed images are supported. 889 890 NOTE: the bzip2 algorithm requires a lot of RAM, so 891 the malloc area (as defined by CFG_MALLOC_LEN) should 892 be at least 4MB. 893 894- Ethernet address: 895 CONFIG_ETHADDR 896 CONFIG_ETH2ADDR 897 CONFIG_ETH3ADDR 898 899 Define a default value for ethernet address to use 900 for the respective ethernet interface, in case this 901 is not determined automatically. 902 903- IP address: 904 CONFIG_IPADDR 905 906 Define a default value for the IP address to use for 907 the default ethernet interface, in case this is not 908 determined through e.g. bootp. 909 910- Server IP address: 911 CONFIG_SERVERIP 912 913 Defines a default value for theIP address of a TFTP 914 server to contact when using the "tftboot" command. 915 916- BOOTP Recovery Mode: 917 CONFIG_BOOTP_RANDOM_DELAY 918 919 If you have many targets in a network that try to 920 boot using BOOTP, you may want to avoid that all 921 systems send out BOOTP requests at precisely the same 922 moment (which would happen for instance at recovery 923 from a power failure, when all systems will try to 924 boot, thus flooding the BOOTP server. Defining 925 CONFIG_BOOTP_RANDOM_DELAY causes a random delay to be 926 inserted before sending out BOOTP requests. The 927 following delays are insterted then: 928 929 1st BOOTP request: delay 0 ... 1 sec 930 2nd BOOTP request: delay 0 ... 2 sec 931 3rd BOOTP request: delay 0 ... 4 sec 932 4th and following 933 BOOTP requests: delay 0 ... 8 sec 934 935- DHCP Advanced Options: 936 CONFIG_BOOTP_MASK 937 938 You can fine tune the DHCP functionality by adding 939 these flags to the CONFIG_BOOTP_MASK define: 940 941 CONFIG_BOOTP_DNS2 - If a DHCP client requests the DNS 942 serverip from a DHCP server, it is possible that more 943 than one DNS serverip is offered to the client. 944 If CONFIG_BOOTP_DNS2 is enabled, the secondary DNS 945 serverip will be stored in the additional environment 946 variable "dnsip2". The first DNS serverip is always 947 stored in the variable "dnsip", when CONFIG_BOOTP_DNS 948 is added to the CONFIG_BOOTP_MASK. 949 950 CONFIG_BOOTP_SEND_HOSTNAME - Some DHCP servers are capable 951 to do a dynamic update of a DNS server. To do this, they 952 need the hostname of the DHCP requester. 953 If CONFIG_BOOP_SEND_HOSTNAME is added to the 954 CONFIG_BOOTP_MASK, the content of the "hostname" 955 environment variable is passed as option 12 to 956 the DHCP server. 957 958- Status LED: CONFIG_STATUS_LED 959 960 Several configurations allow to display the current 961 status using a LED. For instance, the LED will blink 962 fast while running U-Boot code, stop blinking as 963 soon as a reply to a BOOTP request was received, and 964 start blinking slow once the Linux kernel is running 965 (supported by a status LED driver in the Linux 966 kernel). Defining CONFIG_STATUS_LED enables this 967 feature in U-Boot. 968 969- CAN Support: CONFIG_CAN_DRIVER 970 971 Defining CONFIG_CAN_DRIVER enables CAN driver support 972 on those systems that support this (optional) 973 feature, like the TQM8xxL modules. 974 975- I2C Support: CONFIG_HARD_I2C | CONFIG_SOFT_I2C 976 977 These enable I2C serial bus commands. Defining either of 978 (but not both of) CONFIG_HARD_I2C or CONFIG_SOFT_I2C will 979 include the appropriate I2C driver for the selected cpu. 980 981 This will allow you to use i2c commands at the u-boot 982 command line (as long as you set CFG_CMD_I2C in 983 CONFIG_COMMANDS) and communicate with i2c based realtime 984 clock chips. See common/cmd_i2c.c for a description of the 985 command line interface. 986 987 CONFIG_HARD_I2C selects the CPM hardware driver for I2C. 988 989 CONFIG_SOFT_I2C configures u-boot to use a software (aka 990 bit-banging) driver instead of CPM or similar hardware 991 support for I2C. 992 993 There are several other quantities that must also be 994 defined when you define CONFIG_HARD_I2C or CONFIG_SOFT_I2C. 995 996 In both cases you will need to define CFG_I2C_SPEED 997 to be the frequency (in Hz) at which you wish your i2c bus 998 to run and CFG_I2C_SLAVE to be the address of this node (ie 999 the cpu's i2c node address). 1000 1001 Now, the u-boot i2c code for the mpc8xx (cpu/mpc8xx/i2c.c) 1002 sets the cpu up as a master node and so its address should 1003 therefore be cleared to 0 (See, eg, MPC823e User's Manual 1004 p.16-473). So, set CFG_I2C_SLAVE to 0. 1005 1006 That's all that's required for CONFIG_HARD_I2C. 1007 1008 If you use the software i2c interface (CONFIG_SOFT_I2C) 1009 then the following macros need to be defined (examples are 1010 from include/configs/lwmon.h): 1011 1012 I2C_INIT 1013 1014 (Optional). Any commands necessary to enable the I2C 1015 controller or configure ports. 1016 1017 eg: #define I2C_INIT (immr->im_cpm.cp_pbdir |= PB_SCL) 1018 1019 I2C_PORT 1020 1021 (Only for MPC8260 CPU). The I/O port to use (the code 1022 assumes both bits are on the same port). Valid values 1023 are 0..3 for ports A..D. 1024 1025 I2C_ACTIVE 1026 1027 The code necessary to make the I2C data line active 1028 (driven). If the data line is open collector, this 1029 define can be null. 1030 1031 eg: #define I2C_ACTIVE (immr->im_cpm.cp_pbdir |= PB_SDA) 1032 1033 I2C_TRISTATE 1034 1035 The code necessary to make the I2C data line tri-stated 1036 (inactive). If the data line is open collector, this 1037 define can be null. 1038 1039 eg: #define I2C_TRISTATE (immr->im_cpm.cp_pbdir &= ~PB_SDA) 1040 1041 I2C_READ 1042 1043 Code that returns TRUE if the I2C data line is high, 1044 FALSE if it is low. 1045 1046 eg: #define I2C_READ ((immr->im_cpm.cp_pbdat & PB_SDA) != 0) 1047 1048 I2C_SDA(bit) 1049 1050 If <bit> is TRUE, sets the I2C data line high. If it 1051 is FALSE, it clears it (low). 1052 1053 eg: #define I2C_SDA(bit) \ 1054 if(bit) immr->im_cpm.cp_pbdat |= PB_SDA; \ 1055 else immr->im_cpm.cp_pbdat &= ~PB_SDA 1056 1057 I2C_SCL(bit) 1058 1059 If <bit> is TRUE, sets the I2C clock line high. If it 1060 is FALSE, it clears it (low). 1061 1062 eg: #define I2C_SCL(bit) \ 1063 if(bit) immr->im_cpm.cp_pbdat |= PB_SCL; \ 1064 else immr->im_cpm.cp_pbdat &= ~PB_SCL 1065 1066 I2C_DELAY 1067 1068 This delay is invoked four times per clock cycle so this 1069 controls the rate of data transfer. The data rate thus 1070 is 1 / (I2C_DELAY * 4). Often defined to be something 1071 like: 1072 1073 #define I2C_DELAY udelay(2) 1074 1075 CFG_I2C_INIT_BOARD 1076 1077 When a board is reset during an i2c bus transfer 1078 chips might think that the current transfer is still 1079 in progress. On some boards it is possible to access 1080 the i2c SCLK line directly, either by using the 1081 processor pin as a GPIO or by having a second pin 1082 connected to the bus. If this option is defined a 1083 custom i2c_init_board() routine in boards/xxx/board.c 1084 is run early in the boot sequence. 1085 1086- SPI Support: CONFIG_SPI 1087 1088 Enables SPI driver (so far only tested with 1089 SPI EEPROM, also an instance works with Crystal A/D and 1090 D/As on the SACSng board) 1091 1092 CONFIG_SPI_X 1093 1094 Enables extended (16-bit) SPI EEPROM addressing. 1095 (symmetrical to CONFIG_I2C_X) 1096 1097 CONFIG_SOFT_SPI 1098 1099 Enables a software (bit-bang) SPI driver rather than 1100 using hardware support. This is a general purpose 1101 driver that only requires three general I/O port pins 1102 (two outputs, one input) to function. If this is 1103 defined, the board configuration must define several 1104 SPI configuration items (port pins to use, etc). For 1105 an example, see include/configs/sacsng.h. 1106 1107- FPGA Support: CONFIG_FPGA_COUNT 1108 1109 Specify the number of FPGA devices to support. 1110 1111 CONFIG_FPGA 1112 1113 Used to specify the types of FPGA devices. For 1114 example, 1115 #define CONFIG_FPGA CFG_XILINX_VIRTEX2 1116 1117 CFG_FPGA_PROG_FEEDBACK 1118 1119 Enable printing of hash marks during FPGA 1120 configuration. 1121 1122 CFG_FPGA_CHECK_BUSY 1123 1124 Enable checks on FPGA configuration interface busy 1125 status by the configuration function. This option 1126 will require a board or device specific function to 1127 be written. 1128 1129 CONFIG_FPGA_DELAY 1130 1131 If defined, a function that provides delays in the 1132 FPGA configuration driver. 1133 1134 CFG_FPGA_CHECK_CTRLC 1135 1136 Allow Control-C to interrupt FPGA configuration 1137 1138 CFG_FPGA_CHECK_ERROR 1139 1140 Check for configuration errors during FPGA bitfile 1141 loading. For example, abort during Virtex II 1142 configuration if the INIT_B line goes low (which 1143 indicated a CRC error). 1144 1145 CFG_FPGA_WAIT_INIT 1146 1147 Maximum time to wait for the INIT_B line to deassert 1148 after PROB_B has been deasserted during a Virtex II 1149 FPGA configuration sequence. The default time is 500 mS. 1150 1151 CFG_FPGA_WAIT_BUSY 1152 1153 Maximum time to wait for BUSY to deassert during 1154 Virtex II FPGA configuration. The default is 5 mS. 1155 1156 CFG_FPGA_WAIT_CONFIG 1157 1158 Time to wait after FPGA configuration. The default is 1159 200 mS. 1160 1161- FPGA Support: CONFIG_FPGA_COUNT 1162 1163 Specify the number of FPGA devices to support. 1164 1165 CONFIG_FPGA 1166 1167 Used to specify the types of FPGA devices. For example, 1168 #define CONFIG_FPGA CFG_XILINX_VIRTEX2 1169 1170 CFG_FPGA_PROG_FEEDBACK 1171 1172 Enable printing of hash marks during FPGA configuration. 1173 1174 CFG_FPGA_CHECK_BUSY 1175 1176 Enable checks on FPGA configuration interface busy 1177 status by the configuration function. This option 1178 will require a board or device specific function to 1179 be written. 1180 1181 CONFIG_FPGA_DELAY 1182 1183 If defined, a function that provides delays in the FPGA 1184 configuration driver. 1185 1186 CFG_FPGA_CHECK_CTRLC 1187 Allow Control-C to interrupt FPGA configuration 1188 1189 CFG_FPGA_CHECK_ERROR 1190 1191 Check for configuration errors during FPGA bitfile 1192 loading. For example, abort during Virtex II 1193 configuration if the INIT_B line goes low (which 1194 indicated a CRC error). 1195 1196 CFG_FPGA_WAIT_INIT 1197 1198 Maximum time to wait for the INIT_B line to deassert 1199 after PROB_B has been deasserted during a Virtex II 1200 FPGA configuration sequence. The default time is 500 1201 mS. 1202 1203 CFG_FPGA_WAIT_BUSY 1204 1205 Maximum time to wait for BUSY to deassert during 1206 Virtex II FPGA configuration. The default is 5 mS. 1207 1208 CFG_FPGA_WAIT_CONFIG 1209 1210 Time to wait after FPGA configuration. The default is 1211 200 mS. 1212 1213- Configuration Management: 1214 CONFIG_IDENT_STRING 1215 1216 If defined, this string will be added to the U-Boot 1217 version information (U_BOOT_VERSION) 1218 1219- Vendor Parameter Protection: 1220 1221 U-Boot considers the values of the environment 1222 variables "serial#" (Board Serial Number) and 1223 "ethaddr" (Ethernet Address) to be parameters that 1224 are set once by the board vendor / manufacturer, and 1225 protects these variables from casual modification by 1226 the user. Once set, these variables are read-only, 1227 and write or delete attempts are rejected. You can 1228 change this behviour: 1229 1230 If CONFIG_ENV_OVERWRITE is #defined in your config 1231 file, the write protection for vendor parameters is 1232 completely disabled. Anybody can change or delete 1233 these parameters. 1234 1235 Alternatively, if you #define _both_ CONFIG_ETHADDR 1236 _and_ CONFIG_OVERWRITE_ETHADDR_ONCE, a default 1237 ethernet address is installed in the environment, 1238 which can be changed exactly ONCE by the user. [The 1239 serial# is unaffected by this, i. e. it remains 1240 read-only.] 1241 1242- Protected RAM: 1243 CONFIG_PRAM 1244 1245 Define this variable to enable the reservation of 1246 "protected RAM", i. e. RAM which is not overwritten 1247 by U-Boot. Define CONFIG_PRAM to hold the number of 1248 kB you want to reserve for pRAM. You can overwrite 1249 this default value by defining an environment 1250 variable "pram" to the number of kB you want to 1251 reserve. Note that the board info structure will 1252 still show the full amount of RAM. If pRAM is 1253 reserved, a new environment variable "mem" will 1254 automatically be defined to hold the amount of 1255 remaining RAM in a form that can be passed as boot 1256 argument to Linux, for instance like that: 1257 1258 setenv bootargs ... mem=\$(mem) 1259 saveenv 1260 1261 This way you can tell Linux not to use this memory, 1262 either, which results in a memory region that will 1263 not be affected by reboots. 1264 1265 *WARNING* If your board configuration uses automatic 1266 detection of the RAM size, you must make sure that 1267 this memory test is non-destructive. So far, the 1268 following board configurations are known to be 1269 "pRAM-clean": 1270 1271 ETX094, IVMS8, IVML24, SPD8xx, TQM8xxL, 1272 HERMES, IP860, RPXlite, LWMON, LANTEC, 1273 PCU_E, FLAGADM, TQM8260 1274 1275- Error Recovery: 1276 CONFIG_PANIC_HANG 1277 1278 Define this variable to stop the system in case of a 1279 fatal error, so that you have to reset it manually. 1280 This is probably NOT a good idea for an embedded 1281 system where you want to system to reboot 1282 automatically as fast as possible, but it may be 1283 useful during development since you can try to debug 1284 the conditions that lead to the situation. 1285 1286 CONFIG_NET_RETRY_COUNT 1287 1288 This variable defines the number of retries for 1289 network operations like ARP, RARP, TFTP, or BOOTP 1290 before giving up the operation. If not defined, a 1291 default value of 5 is used. 1292 1293- Command Interpreter: 1294 CFG_HUSH_PARSER 1295 1296 Define this variable to enable the "hush" shell (from 1297 Busybox) as command line interpreter, thus enabling 1298 powerful command line syntax like 1299 if...then...else...fi conditionals or `&&' and '||' 1300 constructs ("shell scripts"). 1301 1302 If undefined, you get the old, much simpler behaviour 1303 with a somewhat smaller memory footprint. 1304 1305 1306 CFG_PROMPT_HUSH_PS2 1307 1308 This defines the secondary prompt string, which is 1309 printed when the command interpreter needs more input 1310 to complete a command. Usually "> ". 1311 1312 Note: 1313 1314 In the current implementation, the local variables 1315 space and global environment variables space are 1316 separated. Local variables are those you define by 1317 simply typing `name=value'. To access a local 1318 variable later on, you have write `$name' or 1319 `${name}'; to execute the contents of a variable 1320 directly type `$name' at the command prompt. 1321 1322 Global environment variables are those you use 1323 setenv/printenv to work with. To run a command stored 1324 in such a variable, you need to use the run command, 1325 and you must not use the '$' sign to access them. 1326 1327 To store commands and special characters in a 1328 variable, please use double quotation marks 1329 surrounding the whole text of the variable, instead 1330 of the backslashes before semicolons and special 1331 symbols. 1332 1333- Default Environment 1334 CONFIG_EXTRA_ENV_SETTINGS 1335 1336 Define this to contain any number of null terminated 1337 strings (variable = value pairs) that will be part of 1338 the default environment compiled into the boot image. 1339 1340 For example, place something like this in your 1341 board's config file: 1342 1343 #define CONFIG_EXTRA_ENV_SETTINGS \ 1344 "myvar1=value1\0" \ 1345 "myvar2=value2\0" 1346 1347 Warning: This method is based on knowledge about the 1348 internal format how the environment is stored by the 1349 U-Boot code. This is NOT an official, exported 1350 interface! Although it is unlikely that this format 1351 will change soon, there is no guarantee either. 1352 You better know what you are doing here. 1353 1354 Note: overly (ab)use of the default environment is 1355 discouraged. Make sure to check other ways to preset 1356 the environment like the autoscript function or the 1357 boot command first. 1358 1359- DataFlash Support 1360 CONFIG_HAS_DATAFLASH 1361 1362 Defining this option enables DataFlash features and 1363 allows to read/write in Dataflash via the standard 1364 commands cp, md... 1365 1366- Show boot progress 1367 CONFIG_SHOW_BOOT_PROGRESS 1368 1369 Defining this option allows to add some board- 1370 specific code (calling a user-provided function 1371 "show_boot_progress(int)") that enables you to show 1372 the system's boot progress on some display (for 1373 example, some LED's) on your board. At the moment, 1374 the following checkpoints are implemented: 1375 1376 Arg Where When 1377 1 common/cmd_bootm.c before attempting to boot an image 1378 -1 common/cmd_bootm.c Image header has bad magic number 1379 2 common/cmd_bootm.c Image header has correct magic number 1380 -2 common/cmd_bootm.c Image header has bad checksum 1381 3 common/cmd_bootm.c Image header has correct checksum 1382 -3 common/cmd_bootm.c Image data has bad checksum 1383 4 common/cmd_bootm.c Image data has correct checksum 1384 -4 common/cmd_bootm.c Image is for unsupported architecture 1385 5 common/cmd_bootm.c Architecture check OK 1386 -5 common/cmd_bootm.c Wrong Image Type (not kernel, multi, standalone) 1387 6 common/cmd_bootm.c Image Type check OK 1388 -6 common/cmd_bootm.c gunzip uncompression error 1389 -7 common/cmd_bootm.c Unimplemented compression type 1390 7 common/cmd_bootm.c Uncompression OK 1391 -8 common/cmd_bootm.c Wrong Image Type (not kernel, multi, standalone) 1392 8 common/cmd_bootm.c Image Type check OK 1393 -9 common/cmd_bootm.c Unsupported OS (not Linux, BSD, VxWorks, QNX) 1394 9 common/cmd_bootm.c Start initial ramdisk verification 1395 -10 common/cmd_bootm.c Ramdisk header has bad magic number 1396 -11 common/cmd_bootm.c Ramdisk header has bad checksum 1397 10 common/cmd_bootm.c Ramdisk header is OK 1398 -12 common/cmd_bootm.c Ramdisk data has bad checksum 1399 11 common/cmd_bootm.c Ramdisk data has correct checksum 1400 12 common/cmd_bootm.c Ramdisk verification complete, start loading 1401 -13 common/cmd_bootm.c Wrong Image Type (not PPC Linux Ramdisk) 1402 13 common/cmd_bootm.c Start multifile image verification 1403 14 common/cmd_bootm.c No initial ramdisk, no multifile, continue. 1404 15 common/cmd_bootm.c All preparation done, transferring control to OS 1405 1406 -1 common/cmd_doc.c Bad usage of "doc" command 1407 -1 common/cmd_doc.c No boot device 1408 -1 common/cmd_doc.c Unknown Chip ID on boot device 1409 -1 common/cmd_doc.c Read Error on boot device 1410 -1 common/cmd_doc.c Image header has bad magic number 1411 1412 -1 common/cmd_ide.c Bad usage of "ide" command 1413 -1 common/cmd_ide.c No boot device 1414 -1 common/cmd_ide.c Unknown boot device 1415 -1 common/cmd_ide.c Unknown partition table 1416 -1 common/cmd_ide.c Invalid partition type 1417 -1 common/cmd_ide.c Read Error on boot device 1418 -1 common/cmd_ide.c Image header has bad magic number 1419 1420 -1 common/cmd_nand.c Bad usage of "nand" command 1421 -1 common/cmd_nand.c No boot device 1422 -1 common/cmd_nand.c Unknown Chip ID on boot device 1423 -1 common/cmd_nand.c Read Error on boot device 1424 -1 common/cmd_nand.c Image header has bad magic number 1425 1426 -1 common/env_common.c Environment has a bad CRC, using default 1427 1428 1429Modem Support: 1430-------------- 1431 1432[so far only for SMDK2400 and TRAB boards] 1433 1434- Modem support endable: 1435 CONFIG_MODEM_SUPPORT 1436 1437- RTS/CTS Flow control enable: 1438 CONFIG_HWFLOW 1439 1440- Modem debug support: 1441 CONFIG_MODEM_SUPPORT_DEBUG 1442 1443 Enables debugging stuff (char screen[1024], dbg()) 1444 for modem support. Useful only with BDI2000. 1445 1446- General: 1447 1448 In the target system modem support is enabled when a 1449 specific key (key combination) is pressed during 1450 power-on. Otherwise U-Boot will boot normally 1451 (autoboot). The key_pressed() fuction is called from 1452 board_init(). Currently key_pressed() is a dummy 1453 function, returning 1 and thus enabling modem 1454 initialization. 1455 1456 If there are no modem init strings in the 1457 environment, U-Boot proceed to autoboot; the 1458 previous output (banner, info printfs) will be 1459 supressed, though. 1460 1461 See also: doc/README.Modem 1462 1463 1464Configuration Settings: 1465----------------------- 1466 1467- CFG_LONGHELP: Defined when you want long help messages included; 1468 undefine this when you're short of memory. 1469 1470- CFG_PROMPT: This is what U-Boot prints on the console to 1471 prompt for user input. 1472 1473- CFG_CBSIZE: Buffer size for input from the Console 1474 1475- CFG_PBSIZE: Buffer size for Console output 1476 1477- CFG_MAXARGS: max. Number of arguments accepted for monitor commands 1478 1479- CFG_BARGSIZE: Buffer size for Boot Arguments which are passed to 1480 the application (usually a Linux kernel) when it is 1481 booted 1482 1483- CFG_BAUDRATE_TABLE: 1484 List of legal baudrate settings for this board. 1485 1486- CFG_CONSOLE_INFO_QUIET 1487 Suppress display of console information at boot. 1488 1489- CFG_CONSOLE_IS_IN_ENV 1490 If the board specific function 1491 extern int overwrite_console (void); 1492 returns 1, the stdin, stderr and stdout are switched to the 1493 serial port, else the settings in the environment are used. 1494 1495- CFG_CONSOLE_OVERWRITE_ROUTINE 1496 Enable the call to overwrite_console(). 1497 1498- CFG_CONSOLE_ENV_OVERWRITE 1499 Enable overwrite of previous console environment settings. 1500 1501- CFG_MEMTEST_START, CFG_MEMTEST_END: 1502 Begin and End addresses of the area used by the 1503 simple memory test. 1504 1505- CFG_ALT_MEMTEST: 1506 Enable an alternate, more extensive memory test. 1507 1508- CFG_MEMTEST_SCRATCH: 1509 Scratch address used by the alternate memory test 1510 You only need to set this if address zero isn't writeable 1511 1512- CFG_TFTP_LOADADDR: 1513 Default load address for network file downloads 1514 1515- CFG_LOADS_BAUD_CHANGE: 1516 Enable temporary baudrate change while serial download 1517 1518- CFG_SDRAM_BASE: 1519 Physical start address of SDRAM. _Must_ be 0 here. 1520 1521- CFG_MBIO_BASE: 1522 Physical start address of Motherboard I/O (if using a 1523 Cogent motherboard) 1524 1525- CFG_FLASH_BASE: 1526 Physical start address of Flash memory. 1527 1528- CFG_MONITOR_BASE: 1529 Physical start address of boot monitor code (set by 1530 make config files to be same as the text base address 1531 (TEXT_BASE) used when linking) - same as 1532 CFG_FLASH_BASE when booting from flash. 1533 1534- CFG_MONITOR_LEN: 1535 Size of memory reserved for monitor code, used to 1536 determine _at_compile_time_ (!) if the environment is 1537 embedded within the U-Boot image, or in a separate 1538 flash sector. 1539 1540- CFG_MALLOC_LEN: 1541 Size of DRAM reserved for malloc() use. 1542 1543- CFG_BOOTMAPSZ: 1544 Maximum size of memory mapped by the startup code of 1545 the Linux kernel; all data that must be processed by 1546 the Linux kernel (bd_info, boot arguments, eventually 1547 initrd image) must be put below this limit. 1548 1549- CFG_MAX_FLASH_BANKS: 1550 Max number of Flash memory banks 1551 1552- CFG_MAX_FLASH_SECT: 1553 Max number of sectors on a Flash chip 1554 1555- CFG_FLASH_ERASE_TOUT: 1556 Timeout for Flash erase operations (in ms) 1557 1558- CFG_FLASH_WRITE_TOUT: 1559 Timeout for Flash write operations (in ms) 1560 1561- CFG_FLASH_LOCK_TOUT 1562 Timeout for Flash set sector lock bit operation (in ms) 1563 1564- CFG_FLASH_UNLOCK_TOUT 1565 Timeout for Flash clear lock bits operation (in ms) 1566 1567- CFG_FLASH_PROTECTION 1568 If defined, hardware flash sectors protection is used 1569 instead of U-Boot software protection. 1570 1571- CFG_DIRECT_FLASH_TFTP: 1572 1573 Enable TFTP transfers directly to flash memory; 1574 without this option such a download has to be 1575 performed in two steps: (1) download to RAM, and (2) 1576 copy from RAM to flash. 1577 1578 The two-step approach is usually more reliable, since 1579 you can check if the download worked before you erase 1580 the flash, but in some situations (when sytem RAM is 1581 too limited to allow for a tempory copy of the 1582 downloaded image) this option may be very useful. 1583 1584- CFG_FLASH_CFI: 1585 Define if the flash driver uses extra elements in the 1586 common flash structure for storing flash geometry 1587 1588- CFG_RX_ETH_BUFFER: 1589 Defines the number of ethernet receive buffers. On some 1590 ethernet controllers it is recommended to set this value 1591 to 8 or even higher (EEPRO100 or 405 EMAC), since all 1592 buffers can be full shortly after enabling the interface 1593 on high ethernet traffic. 1594 Defaults to 4 if not defined. 1595 1596The following definitions that deal with the placement and management 1597of environment data (variable area); in general, we support the 1598following configurations: 1599 1600- CFG_ENV_IS_IN_FLASH: 1601 1602 Define this if the environment is in flash memory. 1603 1604 a) The environment occupies one whole flash sector, which is 1605 "embedded" in the text segment with the U-Boot code. This 1606 happens usually with "bottom boot sector" or "top boot 1607 sector" type flash chips, which have several smaller 1608 sectors at the start or the end. For instance, such a 1609 layout can have sector sizes of 8, 2x4, 16, Nx32 kB. In 1610 such a case you would place the environment in one of the 1611 4 kB sectors - with U-Boot code before and after it. With 1612 "top boot sector" type flash chips, you would put the 1613 environment in one of the last sectors, leaving a gap 1614 between U-Boot and the environment. 1615 1616 - CFG_ENV_OFFSET: 1617 1618 Offset of environment data (variable area) to the 1619 beginning of flash memory; for instance, with bottom boot 1620 type flash chips the second sector can be used: the offset 1621 for this sector is given here. 1622 1623 CFG_ENV_OFFSET is used relative to CFG_FLASH_BASE. 1624 1625 - CFG_ENV_ADDR: 1626 1627 This is just another way to specify the start address of 1628 the flash sector containing the environment (instead of 1629 CFG_ENV_OFFSET). 1630 1631 - CFG_ENV_SECT_SIZE: 1632 1633 Size of the sector containing the environment. 1634 1635 1636 b) Sometimes flash chips have few, equal sized, BIG sectors. 1637 In such a case you don't want to spend a whole sector for 1638 the environment. 1639 1640 - CFG_ENV_SIZE: 1641 1642 If you use this in combination with CFG_ENV_IS_IN_FLASH 1643 and CFG_ENV_SECT_SIZE, you can specify to use only a part 1644 of this flash sector for the environment. This saves 1645 memory for the RAM copy of the environment. 1646 1647 It may also save flash memory if you decide to use this 1648 when your environment is "embedded" within U-Boot code, 1649 since then the remainder of the flash sector could be used 1650 for U-Boot code. It should be pointed out that this is 1651 STRONGLY DISCOURAGED from a robustness point of view: 1652 updating the environment in flash makes it always 1653 necessary to erase the WHOLE sector. If something goes 1654 wrong before the contents has been restored from a copy in 1655 RAM, your target system will be dead. 1656 1657 - CFG_ENV_ADDR_REDUND 1658 CFG_ENV_SIZE_REDUND 1659 1660 These settings describe a second storage area used to hold 1661 a redundand copy of the environment data, so that there is 1662 a valid backup copy in case there is a power failure during 1663 a "saveenv" operation. 1664 1665BE CAREFUL! Any changes to the flash layout, and some changes to the 1666source code will make it necessary to adapt <board>/u-boot.lds* 1667accordingly! 1668 1669 1670- CFG_ENV_IS_IN_NVRAM: 1671 1672 Define this if you have some non-volatile memory device 1673 (NVRAM, battery buffered SRAM) which you want to use for the 1674 environment. 1675 1676 - CFG_ENV_ADDR: 1677 - CFG_ENV_SIZE: 1678 1679 These two #defines are used to determin the memory area you 1680 want to use for environment. It is assumed that this memory 1681 can just be read and written to, without any special 1682 provision. 1683 1684BE CAREFUL! The first access to the environment happens quite early 1685in U-Boot initalization (when we try to get the setting of for the 1686console baudrate). You *MUST* have mappend your NVRAM area then, or 1687U-Boot will hang. 1688 1689Please note that even with NVRAM we still use a copy of the 1690environment in RAM: we could work on NVRAM directly, but we want to 1691keep settings there always unmodified except somebody uses "saveenv" 1692to save the current settings. 1693 1694 1695- CFG_ENV_IS_IN_EEPROM: 1696 1697 Use this if you have an EEPROM or similar serial access 1698 device and a driver for it. 1699 1700 - CFG_ENV_OFFSET: 1701 - CFG_ENV_SIZE: 1702 1703 These two #defines specify the offset and size of the 1704 environment area within the total memory of your EEPROM. 1705 1706 - CFG_I2C_EEPROM_ADDR: 1707 If defined, specified the chip address of the EEPROM device. 1708 The default address is zero. 1709 1710 - CFG_EEPROM_PAGE_WRITE_BITS: 1711 If defined, the number of bits used to address bytes in a 1712 single page in the EEPROM device. A 64 byte page, for example 1713 would require six bits. 1714 1715 - CFG_EEPROM_PAGE_WRITE_DELAY_MS: 1716 If defined, the number of milliseconds to delay between 1717 page writes. The default is zero milliseconds. 1718 1719 - CFG_I2C_EEPROM_ADDR_LEN: 1720 The length in bytes of the EEPROM memory array address. Note 1721 that this is NOT the chip address length! 1722 1723 - CFG_EEPROM_SIZE: 1724 The size in bytes of the EEPROM device. 1725 1726 1727- CFG_SPI_INIT_OFFSET 1728 1729 Defines offset to the initial SPI buffer area in DPRAM. The 1730 area is used at an early stage (ROM part) if the environment 1731 is configured to reside in the SPI EEPROM: We need a 520 byte 1732 scratch DPRAM area. It is used between the two initialization 1733 calls (spi_init_f() and spi_init_r()). A value of 0xB00 seems 1734 to be a good choice since it makes it far enough from the 1735 start of the data area as well as from the stack pointer. 1736 1737Please note that the environment is read-only as long as the monitor 1738has been relocated to RAM and a RAM copy of the environment has been 1739created; also, when using EEPROM you will have to use getenv_r() 1740until then to read environment variables. 1741 1742The environment is protected by a CRC32 checksum. Before the monitor 1743is relocated into RAM, as a result of a bad CRC you will be working 1744with the compiled-in default environment - *silently*!!! [This is 1745necessary, because the first environment variable we need is the 1746"baudrate" setting for the console - if we have a bad CRC, we don't 1747have any device yet where we could complain.] 1748 1749Note: once the monitor has been relocated, then it will complain if 1750the default environment is used; a new CRC is computed as soon as you 1751use the "saveenv" command to store a valid environment. 1752 1753- CFG_FAULT_ECHO_LINK_DOWN: 1754 Echo the inverted Ethernet link state to the fault LED. 1755 1756 Note: If this option is active, then CFG_FAULT_MII_ADDR 1757 also needs to be defined. 1758 1759- CFG_FAULT_MII_ADDR: 1760 MII address of the PHY to check for the Ethernet link state. 1761 1762Low Level (hardware related) configuration options: 1763--------------------------------------------------- 1764 1765- CFG_CACHELINE_SIZE: 1766 Cache Line Size of the CPU. 1767 1768- CFG_DEFAULT_IMMR: 1769 Default address of the IMMR after system reset. 1770 1771 Needed on some 8260 systems (MPC8260ADS, PQ2FADS-ZU, 1772 and RPXsuper) to be able to adjust the position of 1773 the IMMR register after a reset. 1774 1775- Floppy Disk Support: 1776 CFG_FDC_DRIVE_NUMBER 1777 1778 the default drive number (default value 0) 1779 1780 CFG_ISA_IO_STRIDE 1781 1782 defines the spacing between fdc chipset registers 1783 (default value 1) 1784 1785 CFG_ISA_IO_OFFSET 1786 1787 defines the offset of register from address. It 1788 depends on which part of the data bus is connected to 1789 the fdc chipset. (default value 0) 1790 1791 If CFG_ISA_IO_STRIDE CFG_ISA_IO_OFFSET and 1792 CFG_FDC_DRIVE_NUMBER are undefined, they take their 1793 default value. 1794 1795 if CFG_FDC_HW_INIT is defined, then the function 1796 fdc_hw_init() is called at the beginning of the FDC 1797 setup. fdc_hw_init() must be provided by the board 1798 source code. It is used to make hardware dependant 1799 initializations. 1800 1801- CFG_IMMR: Physical address of the Internal Memory Mapped 1802 Register; DO NOT CHANGE! (11-4) 1803 [MPC8xx systems only] 1804 1805- CFG_INIT_RAM_ADDR: 1806 1807 Start address of memory area that can be used for 1808 initial data and stack; please note that this must be 1809 writable memory that is working WITHOUT special 1810 initialization, i. e. you CANNOT use normal RAM which 1811 will become available only after programming the 1812 memory controller and running certain initialization 1813 sequences. 1814 1815 U-Boot uses the following memory types: 1816 - MPC8xx and MPC8260: IMMR (internal memory of the CPU) 1817 - MPC824X: data cache 1818 - PPC4xx: data cache 1819 1820- CFG_GBL_DATA_OFFSET: 1821 1822 Offset of the initial data structure in the memory 1823 area defined by CFG_INIT_RAM_ADDR. Usually 1824 CFG_GBL_DATA_OFFSET is chosen such that the initial 1825 data is located at the end of the available space 1826 (sometimes written as (CFG_INIT_RAM_END - 1827 CFG_INIT_DATA_SIZE), and the initial stack is just 1828 below that area (growing from (CFG_INIT_RAM_ADDR + 1829 CFG_GBL_DATA_OFFSET) downward. 1830 1831 Note: 1832 On the MPC824X (or other systems that use the data 1833 cache for initial memory) the address chosen for 1834 CFG_INIT_RAM_ADDR is basically arbitrary - it must 1835 point to an otherwise UNUSED address space between 1836 the top of RAM and the start of the PCI space. 1837 1838- CFG_SIUMCR: SIU Module Configuration (11-6) 1839 1840- CFG_SYPCR: System Protection Control (11-9) 1841 1842- CFG_TBSCR: Time Base Status and Control (11-26) 1843 1844- CFG_PISCR: Periodic Interrupt Status and Control (11-31) 1845 1846- CFG_PLPRCR: PLL, Low-Power, and Reset Control Register (15-30) 1847 1848- CFG_SCCR: System Clock and reset Control Register (15-27) 1849 1850- CFG_OR_TIMING_SDRAM: 1851 SDRAM timing 1852 1853- CFG_MAMR_PTA: 1854 periodic timer for refresh 1855 1856- CFG_DER: Debug Event Register (37-47) 1857 1858- FLASH_BASE0_PRELIM, FLASH_BASE1_PRELIM, CFG_REMAP_OR_AM, 1859 CFG_PRELIM_OR_AM, CFG_OR_TIMING_FLASH, CFG_OR0_REMAP, 1860 CFG_OR0_PRELIM, CFG_BR0_PRELIM, CFG_OR1_REMAP, CFG_OR1_PRELIM, 1861 CFG_BR1_PRELIM: 1862 Memory Controller Definitions: BR0/1 and OR0/1 (FLASH) 1863 1864- SDRAM_BASE2_PRELIM, SDRAM_BASE3_PRELIM, SDRAM_MAX_SIZE, 1865 CFG_OR_TIMING_SDRAM, CFG_OR2_PRELIM, CFG_BR2_PRELIM, 1866 CFG_OR3_PRELIM, CFG_BR3_PRELIM: 1867 Memory Controller Definitions: BR2/3 and OR2/3 (SDRAM) 1868 1869- CFG_MAMR_PTA, CFG_MPTPR_2BK_4K, CFG_MPTPR_1BK_4K, CFG_MPTPR_2BK_8K, 1870 CFG_MPTPR_1BK_8K, CFG_MAMR_8COL, CFG_MAMR_9COL: 1871 Machine Mode Register and Memory Periodic Timer 1872 Prescaler definitions (SDRAM timing) 1873 1874- CFG_I2C_UCODE_PATCH, CFG_I2C_DPMEM_OFFSET [0x1FC0]: 1875 enable I2C microcode relocation patch (MPC8xx); 1876 define relocation offset in DPRAM [DSP2] 1877 1878- CFG_SPI_UCODE_PATCH, CFG_SPI_DPMEM_OFFSET [0x1FC0]: 1879 enable SPI microcode relocation patch (MPC8xx); 1880 define relocation offset in DPRAM [SCC4] 1881 1882- CFG_USE_OSCCLK: 1883 Use OSCM clock mode on MBX8xx board. Be careful, 1884 wrong setting might damage your board. Read 1885 doc/README.MBX before setting this variable! 1886 1887- CFG_CPM_POST_WORD_ADDR: (MPC8xx, MPC8260 only) 1888 Offset of the bootmode word in DPRAM used by post 1889 (Power On Self Tests). This definition overrides 1890 #define'd default value in commproc.h resp. 1891 cpm_8260.h. 1892 1893- CFG_PCI_SLV_MEM_LOCAL, CFG_PCI_SLV_MEM_BUS, CFG_PICMR0_MASK_ATTRIB, 1894 CFG_PCI_MSTR0_LOCAL, CFG_PCIMSK0_MASK, CFG_PCI_MSTR1_LOCAL, 1895 CFG_PCIMSK1_MASK, CFG_PCI_MSTR_MEM_LOCAL, CFG_PCI_MSTR_MEM_BUS, 1896 CFG_CPU_PCI_MEM_START, CFG_PCI_MSTR_MEM_SIZE, CFG_POCMR0_MASK_ATTRIB, 1897 CFG_PCI_MSTR_MEMIO_LOCAL, CFG_PCI_MSTR_MEMIO_BUS, CPU_PCI_MEMIO_START, 1898 CFG_PCI_MSTR_MEMIO_SIZE, CFG_POCMR1_MASK_ATTRIB, CFG_PCI_MSTR_IO_LOCAL, 1899 CFG_PCI_MSTR_IO_BUS, CFG_CPU_PCI_IO_START, CFG_PCI_MSTR_IO_SIZE, 1900 CFG_POCMR2_MASK_ATTRIB: (MPC826x only) 1901 Overrides the default PCI memory map in cpu/mpc8260/pci.c if set. 1902 1903Building the Software: 1904====================== 1905 1906Building U-Boot has been tested in native PPC environments (on a 1907PowerBook G3 running LinuxPPC 2000) and in cross environments 1908(running RedHat 6.x and 7.x Linux on x86, Solaris 2.6 on a SPARC, and 1909NetBSD 1.5 on x86). 1910 1911If you are not using a native PPC environment, it is assumed that you 1912have the GNU cross compiling tools available in your path and named 1913with a prefix of "powerpc-linux-". If this is not the case, (e.g. if 1914you are using Monta Vista's Hard Hat Linux CDK 1.2) you must change 1915the definition of CROSS_COMPILE in Makefile. For HHL on a 4xx CPU, 1916change it to: 1917 1918 CROSS_COMPILE = ppc_4xx- 1919 1920 1921U-Boot is intended to be simple to build. After installing the 1922sources you must configure U-Boot for one specific board type. This 1923is done by typing: 1924 1925 make NAME_config 1926 1927where "NAME_config" is the name of one of the existing 1928configurations; the following names are supported: 1929 1930 ADCIOP_config GTH_config TQM850L_config 1931 ADS860_config IP860_config TQM855L_config 1932 AR405_config IVML24_config TQM860L_config 1933 CANBT_config IVMS8_config WALNUT405_config 1934 CPCI405_config LANTEC_config cogent_common_config 1935 CPCIISER4_config MBX_config cogent_mpc8260_config 1936 CU824_config MBX860T_config cogent_mpc8xx_config 1937 ESTEEM192E_config RPXlite_config hermes_config 1938 ETX094_config RPXsuper_config hymod_config 1939 FADS823_config SM850_config lwmon_config 1940 FADS850SAR_config SPD823TS_config pcu_e_config 1941 FADS860T_config SXNI855T_config rsdproto_config 1942 FPS850L_config Sandpoint8240_config sbc8260_config 1943 GENIETV_config TQM823L_config PIP405_config 1944 GEN860T_config EBONY_config FPS860L_config 1945 ELPT860_config cmi_mpc5xx_config NETVIA_config 1946 at91rm9200dk_config omap1510inn_config MPC8260ADS_config 1947 omap1610inn_config ZPC1900_config 1948 1949Note: for some board special configuration names may exist; check if 1950 additional information is available from the board vendor; for 1951 instance, the TQM8xxL systems run normally at 50 MHz and use a 1952 SCC for 10baseT ethernet; there are also systems with 80 MHz 1953 CPU clock, and an optional Fast Ethernet module is available 1954 for CPU's with FEC. You can select such additional "features" 1955 when chosing the configuration, i. e. 1956 1957 make TQM860L_config 1958 - will configure for a plain TQM860L, i. e. 50MHz, no FEC 1959 1960 make TQM860L_FEC_config 1961 - will configure for a TQM860L at 50MHz with FEC for ethernet 1962 1963 make TQM860L_80MHz_config 1964 - will configure for a TQM860L at 80 MHz, with normal 10baseT 1965 interface 1966 1967 make TQM860L_FEC_80MHz_config 1968 - will configure for a TQM860L at 80 MHz with FEC for ethernet 1969 1970 make TQM823L_LCD_config 1971 - will configure for a TQM823L with U-Boot console on LCD 1972 1973 make TQM823L_LCD_80MHz_config 1974 - will configure for a TQM823L at 80 MHz with U-Boot console on LCD 1975 1976 etc. 1977 1978 1979Finally, type "make all", and you should get some working U-Boot 1980images ready for download to / installation on your system: 1981 1982- "u-boot.bin" is a raw binary image 1983- "u-boot" is an image in ELF binary format 1984- "u-boot.srec" is in Motorola S-Record format 1985 1986 1987Please be aware that the Makefiles assume you are using GNU make, so 1988for instance on NetBSD you might need to use "gmake" instead of 1989native "make". 1990 1991 1992If the system board that you have is not listed, then you will need 1993to port U-Boot to your hardware platform. To do this, follow these 1994steps: 1995 19961. Add a new configuration option for your board to the toplevel 1997 "Makefile" and to the "MAKEALL" script, using the existing 1998 entries as examples. Note that here and at many other places 1999 boards and other names are listed in alphabetical sort order. Please 2000 keep this order. 20012. Create a new directory to hold your board specific code. Add any 2002 files you need. In your board directory, you will need at least 2003 the "Makefile", a "<board>.c", "flash.c" and "u-boot.lds". 20043. Create a new configuration file "include/configs/<board>.h" for 2005 your board 20063. If you're porting U-Boot to a new CPU, then also create a new 2007 directory to hold your CPU specific code. Add any files you need. 20084. Run "make <board>_config" with your new name. 20095. Type "make", and you should get a working "u-boot.srec" file 2010 to be installed on your target system. 20116. Debug and solve any problems that might arise. 2012 [Of course, this last step is much harder than it sounds.] 2013 2014 2015Testing of U-Boot Modifications, Ports to New Hardware, etc.: 2016============================================================== 2017 2018If you have modified U-Boot sources (for instance added a new board 2019or support for new devices, a new CPU, etc.) you are expected to 2020provide feedback to the other developers. The feedback normally takes 2021the form of a "patch", i. e. a context diff against a certain (latest 2022official or latest in CVS) version of U-Boot sources. 2023 2024But before you submit such a patch, please verify that your modifi- 2025cation did not break existing code. At least make sure that *ALL* of 2026the supported boards compile WITHOUT ANY compiler warnings. To do so, 2027just run the "MAKEALL" script, which will configure and build U-Boot 2028for ALL supported system. Be warned, this will take a while. You can 2029select which (cross) compiler to use by passing a `CROSS_COMPILE' 2030environment variable to the script, i. e. to use the cross tools from 2031MontaVista's Hard Hat Linux you can type 2032 2033 CROSS_COMPILE=ppc_8xx- MAKEALL 2034 2035or to build on a native PowerPC system you can type 2036 2037 CROSS_COMPILE=' ' MAKEALL 2038 2039See also "U-Boot Porting Guide" below. 2040 2041 2042Monitor Commands - Overview: 2043============================ 2044 2045go - start application at address 'addr' 2046run - run commands in an environment variable 2047bootm - boot application image from memory 2048bootp - boot image via network using BootP/TFTP protocol 2049tftpboot- boot image via network using TFTP protocol 2050 and env variables "ipaddr" and "serverip" 2051 (and eventually "gatewayip") 2052rarpboot- boot image via network using RARP/TFTP protocol 2053diskboot- boot from IDE devicebootd - boot default, i.e., run 'bootcmd' 2054loads - load S-Record file over serial line 2055loadb - load binary file over serial line (kermit mode) 2056md - memory display 2057mm - memory modify (auto-incrementing) 2058nm - memory modify (constant address) 2059mw - memory write (fill) 2060cp - memory copy 2061cmp - memory compare 2062crc32 - checksum calculation 2063imd - i2c memory display 2064imm - i2c memory modify (auto-incrementing) 2065inm - i2c memory modify (constant address) 2066imw - i2c memory write (fill) 2067icrc32 - i2c checksum calculation 2068iprobe - probe to discover valid I2C chip addresses 2069iloop - infinite loop on address range 2070isdram - print SDRAM configuration information 2071sspi - SPI utility commands 2072base - print or set address offset 2073printenv- print environment variables 2074setenv - set environment variables 2075saveenv - save environment variables to persistent storage 2076protect - enable or disable FLASH write protection 2077erase - erase FLASH memory 2078flinfo - print FLASH memory information 2079bdinfo - print Board Info structure 2080iminfo - print header information for application image 2081coninfo - print console devices and informations 2082ide - IDE sub-system 2083loop - infinite loop on address range 2084mtest - simple RAM test 2085icache - enable or disable instruction cache 2086dcache - enable or disable data cache 2087reset - Perform RESET of the CPU 2088echo - echo args to console 2089version - print monitor version 2090help - print online help 2091? - alias for 'help' 2092 2093 2094Monitor Commands - Detailed Description: 2095======================================== 2096 2097TODO. 2098 2099For now: just type "help <command>". 2100 2101 2102Environment Variables: 2103====================== 2104 2105U-Boot supports user configuration using Environment Variables which 2106can be made persistent by saving to Flash memory. 2107 2108Environment Variables are set using "setenv", printed using 2109"printenv", and saved to Flash using "saveenv". Using "setenv" 2110without a value can be used to delete a variable from the 2111environment. As long as you don't save the environment you are 2112working with an in-memory copy. In case the Flash area containing the 2113environment is erased by accident, a default environment is provided. 2114 2115Some configuration options can be set using Environment Variables: 2116 2117 baudrate - see CONFIG_BAUDRATE 2118 2119 bootdelay - see CONFIG_BOOTDELAY 2120 2121 bootcmd - see CONFIG_BOOTCOMMAND 2122 2123 bootargs - Boot arguments when booting an RTOS image 2124 2125 bootfile - Name of the image to load with TFTP 2126 2127 autoload - if set to "no" (any string beginning with 'n'), 2128 "bootp" will just load perform a lookup of the 2129 configuration from the BOOTP server, but not try to 2130 load any image using TFTP 2131 2132 autostart - if set to "yes", an image loaded using the "bootp", 2133 "rarpboot", "tftpboot" or "diskboot" commands will 2134 be automatically started (by internally calling 2135 "bootm") 2136 2137 If set to "no", a standalone image passed to the 2138 "bootm" command will be copied to the load address 2139 (and eventually uncompressed), but NOT be started. 2140 This can be used to load and uncompress arbitrary 2141 data. 2142 2143 initrd_high - restrict positioning of initrd images: 2144 If this variable is not set, initrd images will be 2145 copied to the highest possible address in RAM; this 2146 is usually what you want since it allows for 2147 maximum initrd size. If for some reason you want to 2148 make sure that the initrd image is loaded below the 2149 CFG_BOOTMAPSZ limit, you can set this environment 2150 variable to a value of "no" or "off" or "0". 2151 Alternatively, you can set it to a maximum upper 2152 address to use (U-Boot will still check that it 2153 does not overwrite the U-Boot stack and data). 2154 2155 For instance, when you have a system with 16 MB 2156 RAM, and want to reserve 4 MB from use by Linux, 2157 you can do this by adding "mem=12M" to the value of 2158 the "bootargs" variable. However, now you must make 2159 sure that the initrd image is placed in the first 2160 12 MB as well - this can be done with 2161 2162 setenv initrd_high 00c00000 2163 2164 If you set initrd_high to 0xFFFFFFFF, this is an 2165 indication to U-Boot that all addresses are legal 2166 for the Linux kernel, including addresses in flash 2167 memory. In this case U-Boot will NOT COPY the 2168 ramdisk at all. This may be useful to reduce the 2169 boot time on your system, but requires that this 2170 feature is supported by your Linux kernel. 2171 2172 ipaddr - IP address; needed for tftpboot command 2173 2174 loadaddr - Default load address for commands like "bootp", 2175 "rarpboot", "tftpboot", "loadb" or "diskboot" 2176 2177 loads_echo - see CONFIG_LOADS_ECHO 2178 2179 serverip - TFTP server IP address; needed for tftpboot command 2180 2181 bootretry - see CONFIG_BOOT_RETRY_TIME 2182 2183 bootdelaykey - see CONFIG_AUTOBOOT_DELAY_STR 2184 2185 bootstopkey - see CONFIG_AUTOBOOT_STOP_STR 2186 2187 2188The following environment variables may be used and automatically 2189updated by the network boot commands ("bootp" and "rarpboot"), 2190depending the information provided by your boot server: 2191 2192 bootfile - see above 2193 dnsip - IP address of your Domain Name Server 2194 dnsip2 - IP address of your secondary Domain Name Server 2195 gatewayip - IP address of the Gateway (Router) to use 2196 hostname - Target hostname 2197 ipaddr - see above 2198 netmask - Subnet Mask 2199 rootpath - Pathname of the root filesystem on the NFS server 2200 serverip - see above 2201 2202 2203There are two special Environment Variables: 2204 2205 serial# - contains hardware identification information such 2206 as type string and/or serial number 2207 ethaddr - Ethernet address 2208 2209These variables can be set only once (usually during manufacturing of 2210the board). U-Boot refuses to delete or overwrite these variables 2211once they have been set once. 2212 2213 2214Further special Environment Variables: 2215 2216 ver - Contains the U-Boot version string as printed 2217 with the "version" command. This variable is 2218 readonly (see CONFIG_VERSION_VARIABLE). 2219 2220 2221Please note that changes to some configuration parameters may take 2222only effect after the next boot (yes, that's just like Windoze :-). 2223 2224 2225Command Line Parsing: 2226===================== 2227 2228There are two different command line parsers available with U-Boot: 2229the old "simple" one, and the much more powerful "hush" shell: 2230 2231Old, simple command line parser: 2232-------------------------------- 2233 2234- supports environment variables (through setenv / saveenv commands) 2235- several commands on one line, separated by ';' 2236- variable substitution using "... $(name) ..." syntax 2237- special characters ('$', ';') can be escaped by prefixing with '\', 2238 for example: 2239 setenv bootcmd bootm \$(address) 2240- You can also escape text by enclosing in single apostrophes, for example: 2241 setenv addip 'setenv bootargs $bootargs ip=$ipaddr:$serverip:$gatewayip:$netmask:$hostname::off' 2242 2243Hush shell: 2244----------- 2245 2246- similar to Bourne shell, with control structures like 2247 if...then...else...fi, for...do...done; while...do...done, 2248 until...do...done, ... 2249- supports environment ("global") variables (through setenv / saveenv 2250 commands) and local shell variables (through standard shell syntax 2251 "name=value"); only environment variables can be used with "run" 2252 command 2253 2254General rules: 2255-------------- 2256 2257(1) If a command line (or an environment variable executed by a "run" 2258 command) contains several commands separated by semicolon, and 2259 one of these commands fails, then the remaining commands will be 2260 executed anyway. 2261 2262(2) If you execute several variables with one call to run (i. e. 2263 calling run with a list af variables as arguments), any failing 2264 command will cause "run" to terminate, i. e. the remaining 2265 variables are not executed. 2266 2267Note for Redundant Ethernet Interfaces: 2268======================================= 2269 2270Some boards come with redundant ethernet interfaces; U-Boot supports 2271such configurations and is capable of automatic selection of a 2272"working" interface when needed. MAC assignment works as follows: 2273 2274Network interfaces are numbered eth0, eth1, eth2, ... Corresponding 2275MAC addresses can be stored in the environment as "ethaddr" (=>eth0), 2276"eth1addr" (=>eth1), "eth2addr", ... 2277 2278If the network interface stores some valid MAC address (for instance 2279in SROM), this is used as default address if there is NO correspon- 2280ding setting in the environment; if the corresponding environment 2281variable is set, this overrides the settings in the card; that means: 2282 2283o If the SROM has a valid MAC address, and there is no address in the 2284 environment, the SROM's address is used. 2285 2286o If there is no valid address in the SROM, and a definition in the 2287 environment exists, then the value from the environment variable is 2288 used. 2289 2290o If both the SROM and the environment contain a MAC address, and 2291 both addresses are the same, this MAC address is used. 2292 2293o If both the SROM and the environment contain a MAC address, and the 2294 addresses differ, the value from the environment is used and a 2295 warning is printed. 2296 2297o If neither SROM nor the environment contain a MAC address, an error 2298 is raised. 2299 2300 2301Image Formats: 2302============== 2303 2304The "boot" commands of this monitor operate on "image" files which 2305can be basicly anything, preceeded by a special header; see the 2306definitions in include/image.h for details; basicly, the header 2307defines the following image properties: 2308 2309* Target Operating System (Provisions for OpenBSD, NetBSD, FreeBSD, 2310 4.4BSD, Linux, SVR4, Esix, Solaris, Irix, SCO, Dell, NCR, VxWorks, 2311 LynxOS, pSOS, QNX, RTEMS, ARTOS; 2312 Currently supported: Linux, NetBSD, VxWorks, QNX, RTEMS, ARTOS, LynxOS). 2313* Target CPU Architecture (Provisions for Alpha, ARM, Intel x86, 2314 IA64, MIPS, MIPS, PowerPC, IBM S390, SuperH, Sparc, Sparc 64 Bit; 2315 Currently supported: PowerPC). 2316* Compression Type (uncompressed, gzip, bzip2) 2317* Load Address 2318* Entry Point 2319* Image Name 2320* Image Timestamp 2321 2322The header is marked by a special Magic Number, and both the header 2323and the data portions of the image are secured against corruption by 2324CRC32 checksums. 2325 2326 2327Linux Support: 2328============== 2329 2330Although U-Boot should support any OS or standalone application 2331easily, the main focus has always been on Linux during the design of 2332U-Boot. 2333 2334U-Boot includes many features that so far have been part of some 2335special "boot loader" code within the Linux kernel. Also, any 2336"initrd" images to be used are no longer part of one big Linux image; 2337instead, kernel and "initrd" are separate images. This implementation 2338serves several purposes: 2339 2340- the same features can be used for other OS or standalone 2341 applications (for instance: using compressed images to reduce the 2342 Flash memory footprint) 2343 2344- it becomes much easier to port new Linux kernel versions because 2345 lots of low-level, hardware dependent stuff are done by U-Boot 2346 2347- the same Linux kernel image can now be used with different "initrd" 2348 images; of course this also means that different kernel images can 2349 be run with the same "initrd". This makes testing easier (you don't 2350 have to build a new "zImage.initrd" Linux image when you just 2351 change a file in your "initrd"). Also, a field-upgrade of the 2352 software is easier now. 2353 2354 2355Linux HOWTO: 2356============ 2357 2358Porting Linux to U-Boot based systems: 2359--------------------------------------- 2360 2361U-Boot cannot save you from doing all the necessary modifications to 2362configure the Linux device drivers for use with your target hardware 2363(no, we don't intend to provide a full virtual machine interface to 2364Linux :-). 2365 2366But now you can ignore ALL boot loader code (in arch/ppc/mbxboot). 2367 2368Just make sure your machine specific header file (for instance 2369include/asm-ppc/tqm8xx.h) includes the same definition of the Board 2370Information structure as we define in include/u-boot.h, and make 2371sure that your definition of IMAP_ADDR uses the same value as your 2372U-Boot configuration in CFG_IMMR. 2373 2374 2375Configuring the Linux kernel: 2376----------------------------- 2377 2378No specific requirements for U-Boot. Make sure you have some root 2379device (initial ramdisk, NFS) for your target system. 2380 2381 2382Building a Linux Image: 2383----------------------- 2384 2385With U-Boot, "normal" build targets like "zImage" or "bzImage" are 2386not used. If you use recent kernel source, a new build target 2387"uImage" will exist which automatically builds an image usable by 2388U-Boot. Most older kernels also have support for a "pImage" target, 2389which was introduced for our predecessor project PPCBoot and uses a 2390100% compatible format. 2391 2392Example: 2393 2394 make TQM850L_config 2395 make oldconfig 2396 make dep 2397 make uImage 2398 2399The "uImage" build target uses a special tool (in 'tools/mkimage') to 2400encapsulate a compressed Linux kernel image with header information, 2401CRC32 checksum etc. for use with U-Boot. This is what we are doing: 2402 2403* build a standard "vmlinux" kernel image (in ELF binary format): 2404 2405* convert the kernel into a raw binary image: 2406 2407 ${CROSS_COMPILE}-objcopy -O binary \ 2408 -R .note -R .comment \ 2409 -S vmlinux linux.bin 2410 2411* compress the binary image: 2412 2413 gzip -9 linux.bin 2414 2415* package compressed binary image for U-Boot: 2416 2417 mkimage -A ppc -O linux -T kernel -C gzip \ 2418 -a 0 -e 0 -n "Linux Kernel Image" \ 2419 -d linux.bin.gz uImage 2420 2421 2422The "mkimage" tool can also be used to create ramdisk images for use 2423with U-Boot, either separated from the Linux kernel image, or 2424combined into one file. "mkimage" encapsulates the images with a 64 2425byte header containing information about target architecture, 2426operating system, image type, compression method, entry points, time 2427stamp, CRC32 checksums, etc. 2428 2429"mkimage" can be called in two ways: to verify existing images and 2430print the header information, or to build new images. 2431 2432In the first form (with "-l" option) mkimage lists the information 2433contained in the header of an existing U-Boot image; this includes 2434checksum verification: 2435 2436 tools/mkimage -l image 2437 -l ==> list image header information 2438 2439The second form (with "-d" option) is used to build a U-Boot image 2440from a "data file" which is used as image payload: 2441 2442 tools/mkimage -A arch -O os -T type -C comp -a addr -e ep \ 2443 -n name -d data_file image 2444 -A ==> set architecture to 'arch' 2445 -O ==> set operating system to 'os' 2446 -T ==> set image type to 'type' 2447 -C ==> set compression type 'comp' 2448 -a ==> set load address to 'addr' (hex) 2449 -e ==> set entry point to 'ep' (hex) 2450 -n ==> set image name to 'name' 2451 -d ==> use image data from 'datafile' 2452 2453Right now, all Linux kernels use the same load address (0x00000000), 2454but the entry point address depends on the kernel version: 2455 2456- 2.2.x kernels have the entry point at 0x0000000C, 2457- 2.3.x and later kernels have the entry point at 0x00000000. 2458 2459So a typical call to build a U-Boot image would read: 2460 2461 -> tools/mkimage -n '2.4.4 kernel for TQM850L' \ 2462 > -A ppc -O linux -T kernel -C gzip -a 0 -e 0 \ 2463 > -d /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/ppc/coffboot/vmlinux.gz \ 2464 > 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 2472To verify the contents of the image (or check for corruption): 2473 2474 -> tools/mkimage -l examples/uImage.TQM850L 2475 Image Name: 2.4.4 kernel for TQM850L 2476 Created: Wed Jul 19 02:34:59 2000 2477 Image Type: PowerPC Linux Kernel Image (gzip compressed) 2478 Data Size: 335725 Bytes = 327.86 kB = 0.32 MB 2479 Load Address: 0x00000000 2480 Entry Point: 0x00000000 2481 2482NOTE: for embedded systems where boot time is critical you can trade 2483speed for memory and install an UNCOMPRESSED image instead: this 2484needs more space in Flash, but boots much faster since it does not 2485need to be uncompressed: 2486 2487 -> gunzip /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/ppc/coffboot/vmlinux.gz 2488 -> tools/mkimage -n '2.4.4 kernel for TQM850L' \ 2489 > -A ppc -O linux -T kernel -C none -a 0 -e 0 \ 2490 > -d /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/ppc/coffboot/vmlinux \ 2491 > examples/uImage.TQM850L-uncompressed 2492 Image Name: 2.4.4 kernel for TQM850L 2493 Created: Wed Jul 19 02:34:59 2000 2494 Image Type: PowerPC Linux Kernel Image (uncompressed) 2495 Data Size: 792160 Bytes = 773.59 kB = 0.76 MB 2496 Load Address: 0x00000000 2497 Entry Point: 0x00000000 2498 2499 2500Similar you can build U-Boot images from a 'ramdisk.image.gz' file 2501when your kernel is intended to use an initial ramdisk: 2502 2503 -> tools/mkimage -n 'Simple Ramdisk Image' \ 2504 > -A ppc -O linux -T ramdisk -C gzip \ 2505 > -d /LinuxPPC/images/SIMPLE-ramdisk.image.gz examples/simple-initrd 2506 Image Name: Simple Ramdisk Image 2507 Created: Wed Jan 12 14:01:50 2000 2508 Image Type: PowerPC Linux RAMDisk Image (gzip compressed) 2509 Data Size: 566530 Bytes = 553.25 kB = 0.54 MB 2510 Load Address: 0x00000000 2511 Entry Point: 0x00000000 2512 2513 2514Installing a Linux Image: 2515------------------------- 2516 2517To downloading a U-Boot image over the serial (console) interface, 2518you must convert the image to S-Record format: 2519 2520 objcopy -I binary -O srec examples/image examples/image.srec 2521 2522The 'objcopy' does not understand the information in the U-Boot 2523image header, so the resulting S-Record file will be relative to 2524address 0x00000000. To load it to a given address, you need to 2525specify the target address as 'offset' parameter with the 'loads' 2526command. 2527 2528Example: install the image to address 0x40100000 (which on the 2529TQM8xxL is in the first Flash bank): 2530 2531 => erase 40100000 401FFFFF 2532 2533 .......... done 2534 Erased 8 sectors 2535 2536 => loads 40100000 2537 ## Ready for S-Record download ... 2538 ~>examples/image.srec 2539 1 2 3 4 5 6 7 8 9 10 11 12 13 ... 2540 ... 2541 15989 15990 15991 15992 2542 [file transfer complete] 2543 [connected] 2544 ## Start Addr = 0x00000000 2545 2546 2547You can check the success of the download using the 'iminfo' command; 2548this includes a checksum verification so you can be sure no data 2549corruption happened: 2550 2551 => imi 40100000 2552 2553 ## Checking Image at 40100000 ... 2554 Image Name: 2.2.13 for initrd on TQM850L 2555 Image Type: PowerPC Linux Kernel Image (gzip compressed) 2556 Data Size: 335725 Bytes = 327 kB = 0 MB 2557 Load Address: 00000000 2558 Entry Point: 0000000c 2559 Verifying Checksum ... OK 2560 2561 2562Boot Linux: 2563----------- 2564 2565The "bootm" command is used to boot an application that is stored in 2566memory (RAM or Flash). In case of a Linux kernel image, the contents 2567of the "bootargs" environment variable is passed to the kernel as 2568parameters. You can check and modify this variable using the 2569"printenv" and "setenv" commands: 2570 2571 2572 => printenv bootargs 2573 bootargs=root=/dev/ram 2574 2575 => setenv bootargs root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2 2576 2577 => printenv bootargs 2578 bootargs=root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2 2579 2580 => bootm 40020000 2581 ## Booting Linux kernel at 40020000 ... 2582 Image Name: 2.2.13 for NFS on TQM850L 2583 Image Type: PowerPC Linux Kernel Image (gzip compressed) 2584 Data Size: 381681 Bytes = 372 kB = 0 MB 2585 Load Address: 00000000 2586 Entry Point: 0000000c 2587 Verifying Checksum ... OK 2588 Uncompressing Kernel Image ... OK 2589 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 2590 Boot arguments: root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2 2591 time_init: decrementer frequency = 187500000/60 2592 Calibrating delay loop... 49.77 BogoMIPS 2593 Memory: 15208k available (700k kernel code, 444k data, 32k init) [c0000000,c1000000] 2594 ... 2595 2596If you want to boot a Linux kernel with initial ram disk, you pass 2597the memory addresses of both the kernel and the initrd image (PPBCOOT 2598format!) to the "bootm" command: 2599 2600 => imi 40100000 40200000 2601 2602 ## Checking Image at 40100000 ... 2603 Image Name: 2.2.13 for initrd on TQM850L 2604 Image Type: PowerPC Linux Kernel Image (gzip compressed) 2605 Data Size: 335725 Bytes = 327 kB = 0 MB 2606 Load Address: 00000000 2607 Entry Point: 0000000c 2608 Verifying Checksum ... OK 2609 2610 ## Checking Image at 40200000 ... 2611 Image Name: Simple Ramdisk Image 2612 Image Type: PowerPC Linux RAMDisk Image (gzip compressed) 2613 Data Size: 566530 Bytes = 553 kB = 0 MB 2614 Load Address: 00000000 2615 Entry Point: 00000000 2616 Verifying Checksum ... OK 2617 2618 => bootm 40100000 40200000 2619 ## Booting Linux kernel at 40100000 ... 2620 Image Name: 2.2.13 for initrd on TQM850L 2621 Image Type: PowerPC Linux Kernel Image (gzip compressed) 2622 Data Size: 335725 Bytes = 327 kB = 0 MB 2623 Load Address: 00000000 2624 Entry Point: 0000000c 2625 Verifying Checksum ... OK 2626 Uncompressing Kernel Image ... OK 2627 ## Loading RAMDisk Image at 40200000 ... 2628 Image Name: Simple Ramdisk Image 2629 Image Type: PowerPC Linux RAMDisk Image (gzip compressed) 2630 Data Size: 566530 Bytes = 553 kB = 0 MB 2631 Load Address: 00000000 2632 Entry Point: 00000000 2633 Verifying Checksum ... OK 2634 Loading Ramdisk ... OK 2635 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 2636 Boot arguments: root=/dev/ram 2637 time_init: decrementer frequency = 187500000/60 2638 Calibrating delay loop... 49.77 BogoMIPS 2639 ... 2640 RAMDISK: Compressed image found at block 0 2641 VFS: Mounted root (ext2 filesystem). 2642 2643 bash# 2644 2645More About U-Boot Image Types: 2646------------------------------ 2647 2648U-Boot supports the following image types: 2649 2650 "Standalone Programs" are directly runnable in the environment 2651 provided by U-Boot; it is expected that (if they behave 2652 well) you can continue to work in U-Boot after return from 2653 the Standalone Program. 2654 "OS Kernel Images" are usually images of some Embedded OS which 2655 will take over control completely. Usually these programs 2656 will install their own set of exception handlers, device 2657 drivers, set up the MMU, etc. - this means, that you cannot 2658 expect to re-enter U-Boot except by resetting the CPU. 2659 "RAMDisk Images" are more or less just data blocks, and their 2660 parameters (address, size) are passed to an OS kernel that is 2661 being started. 2662 "Multi-File Images" contain several images, typically an OS 2663 (Linux) kernel image and one or more data images like 2664 RAMDisks. This construct is useful for instance when you want 2665 to boot over the network using BOOTP etc., where the boot 2666 server provides just a single image file, but you want to get 2667 for instance an OS kernel and a RAMDisk image. 2668 2669 "Multi-File Images" start with a list of image sizes, each 2670 image size (in bytes) specified by an "uint32_t" in network 2671 byte order. This list is terminated by an "(uint32_t)0". 2672 Immediately after the terminating 0 follow the images, one by 2673 one, all aligned on "uint32_t" boundaries (size rounded up to 2674 a multiple of 4 bytes). 2675 2676 "Firmware Images" are binary images containing firmware (like 2677 U-Boot or FPGA images) which usually will be programmed to 2678 flash memory. 2679 2680 "Script files" are command sequences that will be executed by 2681 U-Boot's command interpreter; this feature is especially 2682 useful when you configure U-Boot to use a real shell (hush) 2683 as command interpreter. 2684 2685 2686Standalone HOWTO: 2687================= 2688 2689One of the features of U-Boot is that you can dynamically load and 2690run "standalone" applications, which can use some resources of 2691U-Boot like console I/O functions or interrupt services. 2692 2693Two simple examples are included with the sources: 2694 2695"Hello World" Demo: 2696------------------- 2697 2698'examples/hello_world.c' contains a small "Hello World" Demo 2699application; it is automatically compiled when you build U-Boot. 2700It's configured to run at address 0x00040004, so you can play with it 2701like that: 2702 2703 => loads 2704 ## Ready for S-Record download ... 2705 ~>examples/hello_world.srec 2706 1 2 3 4 5 6 7 8 9 10 11 ... 2707 [file transfer complete] 2708 [connected] 2709 ## Start Addr = 0x00040004 2710 2711 => go 40004 Hello World! This is a test. 2712 ## Starting application at 0x00040004 ... 2713 Hello World 2714 argc = 7 2715 argv[0] = "40004" 2716 argv[1] = "Hello" 2717 argv[2] = "World!" 2718 argv[3] = "This" 2719 argv[4] = "is" 2720 argv[5] = "a" 2721 argv[6] = "test." 2722 argv[7] = "<NULL>" 2723 Hit any key to exit ... 2724 2725 ## Application terminated, rc = 0x0 2726 2727Another example, which demonstrates how to register a CPM interrupt 2728handler with the U-Boot code, can be found in 'examples/timer.c'. 2729Here, a CPM timer is set up to generate an interrupt every second. 2730The interrupt service routine is trivial, just printing a '.' 2731character, but this is just a demo program. The application can be 2732controlled by the following keys: 2733 2734 ? - print current values og the CPM Timer registers 2735 b - enable interrupts and start timer 2736 e - stop timer and disable interrupts 2737 q - quit application 2738 2739 => loads 2740 ## Ready for S-Record download ... 2741 ~>examples/timer.srec 2742 1 2 3 4 5 6 7 8 9 10 11 ... 2743 [file transfer complete] 2744 [connected] 2745 ## Start Addr = 0x00040004 2746 2747 => go 40004 2748 ## Starting application at 0x00040004 ... 2749 TIMERS=0xfff00980 2750 Using timer 1 2751 tgcr @ 0xfff00980, tmr @ 0xfff00990, trr @ 0xfff00994, tcr @ 0xfff00998, tcn @ 0xfff0099c, ter @ 0xfff009b0 2752 2753Hit 'b': 2754 [q, b, e, ?] Set interval 1000000 us 2755 Enabling timer 2756Hit '?': 2757 [q, b, e, ?] ........ 2758 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0xef6, ter=0x0 2759Hit '?': 2760 [q, b, e, ?] . 2761 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x2ad4, ter=0x0 2762Hit '?': 2763 [q, b, e, ?] . 2764 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x1efc, ter=0x0 2765Hit '?': 2766 [q, b, e, ?] . 2767 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x169d, ter=0x0 2768Hit 'e': 2769 [q, b, e, ?] ...Stopping timer 2770Hit 'q': 2771 [q, b, e, ?] ## Application terminated, rc = 0x0 2772 2773 2774Minicom warning: 2775================ 2776 2777Over time, many people have reported problems when trying to use the 2778"minicom" terminal emulation program for serial download. I (wd) 2779consider minicom to be broken, and recommend not to use it. Under 2780Unix, I recommend to use C-Kermit for general purpose use (and 2781especially for kermit binary protocol download ("loadb" command), and 2782use "cu" for S-Record download ("loads" command). 2783 2784Nevertheless, if you absolutely want to use it try adding this 2785configuration to your "File transfer protocols" section: 2786 2787 Name Program Name U/D FullScr IO-Red. Multi 2788 X kermit /usr/bin/kermit -i -l %l -s Y U Y N N 2789 Y kermit /usr/bin/kermit -i -l %l -r N D Y N N 2790 2791 2792NetBSD Notes: 2793============= 2794 2795Starting at version 0.9.2, U-Boot supports NetBSD both as host 2796(build U-Boot) and target system (boots NetBSD/mpc8xx). 2797 2798Building requires a cross environment; it is known to work on 2799NetBSD/i386 with the cross-powerpc-netbsd-1.3 package (you will also 2800need gmake since the Makefiles are not compatible with BSD make). 2801Note that the cross-powerpc package does not install include files; 2802attempting to build U-Boot will fail because <machine/ansi.h> is 2803missing. This file has to be installed and patched manually: 2804 2805 # cd /usr/pkg/cross/powerpc-netbsd/include 2806 # mkdir powerpc 2807 # ln -s powerpc machine 2808 # cp /usr/src/sys/arch/powerpc/include/ansi.h powerpc/ansi.h 2809 # ${EDIT} powerpc/ansi.h ## must remove __va_list, _BSD_VA_LIST 2810 2811Native builds *don't* work due to incompatibilities between native 2812and U-Boot include files. 2813 2814Booting assumes that (the first part of) the image booted is a 2815stage-2 loader which in turn loads and then invokes the kernel 2816proper. Loader sources will eventually appear in the NetBSD source 2817tree (probably in sys/arc/mpc8xx/stand/u-boot_stage2/); in the 2818meantime, send mail to bruno@exet-ag.de and/or wd@denx.de for 2819details. 2820 2821 2822Implementation Internals: 2823========================= 2824 2825The following is not intended to be a complete description of every 2826implementation detail. However, it should help to understand the 2827inner workings of U-Boot and make it easier to port it to custom 2828hardware. 2829 2830 2831Initial Stack, Global Data: 2832--------------------------- 2833 2834The implementation of U-Boot is complicated by the fact that U-Boot 2835starts running out of ROM (flash memory), usually without access to 2836system RAM (because the memory controller is not initialized yet). 2837This means that we don't have writable Data or BSS segments, and BSS 2838is not initialized as zero. To be able to get a C environment working 2839at all, we have to allocate at least a minimal stack. Implementation 2840options for this are defined and restricted by the CPU used: Some CPU 2841models provide on-chip memory (like the IMMR area on MPC8xx and 2842MPC826x processors), on others (parts of) the data cache can be 2843locked as (mis-) used as memory, etc. 2844 2845 Chris Hallinan posted a good summary of these issues to the 2846 u-boot-users mailing list: 2847 2848 Subject: RE: [U-Boot-Users] RE: More On Memory Bank x (nothingness)? 2849 From: "Chris Hallinan" <clh@net1plus.com> 2850 Date: Mon, 10 Feb 2003 16:43:46 -0500 (22:43 MET) 2851 ... 2852 2853 Correct me if I'm wrong, folks, but the way I understand it 2854 is this: Using DCACHE as initial RAM for Stack, etc, does not 2855 require any physical RAM backing up the cache. The cleverness 2856 is that the cache is being used as a temporary supply of 2857 necessary storage before the SDRAM controller is setup. It's 2858 beyond the scope of this list to expain the details, but you 2859 can see how this works by studying the cache architecture and 2860 operation in the architecture and processor-specific manuals. 2861 2862 OCM is On Chip Memory, which I believe the 405GP has 4K. It 2863 is another option for the system designer to use as an 2864 initial stack/ram area prior to SDRAM being available. Either 2865 option should work for you. Using CS 4 should be fine if your 2866 board designers haven't used it for something that would 2867 cause you grief during the initial boot! It is frequently not 2868 used. 2869 2870 CFG_INIT_RAM_ADDR should be somewhere that won't interfere 2871 with your processor/board/system design. The default value 2872 you will find in any recent u-boot distribution in 2873 Walnut405.h should work for you. I'd set it to a value larger 2874 than your SDRAM module. If you have a 64MB SDRAM module, set 2875 it above 400_0000. Just make sure your board has no resources 2876 that are supposed to respond to that address! That code in 2877 start.S has been around a while and should work as is when 2878 you get the config right. 2879 2880 -Chris Hallinan 2881 DS4.COM, Inc. 2882 2883It is essential to remember this, since it has some impact on the C 2884code for the initialization procedures: 2885 2886* Initialized global data (data segment) is read-only. Do not attempt 2887 to write it. 2888 2889* Do not use any unitialized global data (or implicitely initialized 2890 as zero data - BSS segment) at all - this is undefined, initiali- 2891 zation is performed later (when relocating to RAM). 2892 2893* Stack space is very limited. Avoid big data buffers or things like 2894 that. 2895 2896Having only the stack as writable memory limits means we cannot use 2897normal global data to share information beween the code. But it 2898turned out that the implementation of U-Boot can be greatly 2899simplified by making a global data structure (gd_t) available to all 2900functions. We could pass a pointer to this data as argument to _all_ 2901functions, but this would bloat the code. Instead we use a feature of 2902the GCC compiler (Global Register Variables) to share the data: we 2903place a pointer (gd) to the global data into a register which we 2904reserve for this purpose. 2905 2906When choosing a register for such a purpose we are restricted by the 2907relevant (E)ABI specifications for the current architecture, and by 2908GCC's implementation. 2909 2910For PowerPC, the following registers have specific use: 2911 R1: stack pointer 2912 R2: TOC pointer 2913 R3-R4: parameter passing and return values 2914 R5-R10: parameter passing 2915 R13: small data area pointer 2916 R30: GOT pointer 2917 R31: frame pointer 2918 2919 (U-Boot also uses R14 as internal GOT pointer.) 2920 2921 ==> U-Boot will use R29 to hold a pointer to the global data 2922 2923 Note: on PPC, we could use a static initializer (since the 2924 address of the global data structure is known at compile time), 2925 but it turned out that reserving a register results in somewhat 2926 smaller code - although the code savings are not that big (on 2927 average for all boards 752 bytes for the whole U-Boot image, 2928 624 text + 127 data). 2929 2930On ARM, the following registers are used: 2931 2932 R0: function argument word/integer result 2933 R1-R3: function argument word 2934 R9: GOT pointer 2935 R10: stack limit (used only if stack checking if enabled) 2936 R11: argument (frame) pointer 2937 R12: temporary workspace 2938 R13: stack pointer 2939 R14: link register 2940 R15: program counter 2941 2942 ==> U-Boot will use R8 to hold a pointer to the global data 2943 2944 2945Memory Management: 2946------------------ 2947 2948U-Boot runs in system state and uses physical addresses, i.e. the 2949MMU is not used either for address mapping nor for memory protection. 2950 2951The available memory is mapped to fixed addresses using the memory 2952controller. In this process, a contiguous block is formed for each 2953memory type (Flash, SDRAM, SRAM), even when it consists of several 2954physical memory banks. 2955 2956U-Boot is installed in the first 128 kB of the first Flash bank (on 2957TQM8xxL modules this is the range 0x40000000 ... 0x4001FFFF). After 2958booting and sizing and initializing DRAM, the code relocates itself 2959to the upper end of DRAM. Immediately below the U-Boot code some 2960memory is reserved for use by malloc() [see CFG_MALLOC_LEN 2961configuration setting]. Below that, a structure with global Board 2962Info data is placed, followed by the stack (growing downward). 2963 2964Additionally, some exception handler code is copied to the low 8 kB 2965of DRAM (0x00000000 ... 0x00001FFF). 2966 2967So a typical memory configuration with 16 MB of DRAM could look like 2968this: 2969 2970 0x0000 0000 Exception Vector code 2971 : 2972 0x0000 1FFF 2973 0x0000 2000 Free for Application Use 2974 : 2975 : 2976 2977 : 2978 : 2979 0x00FB FF20 Monitor Stack (Growing downward) 2980 0x00FB FFAC Board Info Data and permanent copy of global data 2981 0x00FC 0000 Malloc Arena 2982 : 2983 0x00FD FFFF 2984 0x00FE 0000 RAM Copy of Monitor Code 2985 ... eventually: LCD or video framebuffer 2986 ... eventually: pRAM (Protected RAM - unchanged by reset) 2987 0x00FF FFFF [End of RAM] 2988 2989 2990System Initialization: 2991---------------------- 2992 2993In the reset configuration, U-Boot starts at the reset entry point 2994(on most PowerPC systens at address 0x00000100). Because of the reset 2995configuration for CS0# this is a mirror of the onboard Flash memory. 2996To be able to re-map memory U-Boot then jumps to its link address. 2997To be able to implement the initialization code in C, a (small!) 2998initial stack is set up in the internal Dual Ported RAM (in case CPUs 2999which provide such a feature like MPC8xx or MPC8260), or in a locked 3000part of the data cache. After that, U-Boot initializes the CPU core, 3001the caches and the SIU. 3002 3003Next, all (potentially) available memory banks are mapped using a 3004preliminary mapping. For example, we put them on 512 MB boundaries 3005(multiples of 0x20000000: SDRAM on 0x00000000 and 0x20000000, Flash 3006on 0x40000000 and 0x60000000, SRAM on 0x80000000). Then UPM A is 3007programmed for SDRAM access. Using the temporary configuration, a 3008simple memory test is run that determines the size of the SDRAM 3009banks. 3010 3011When there is more than one SDRAM bank, and the banks are of 3012different size, the largest is mapped first. For equal size, the first 3013bank (CS2#) is mapped first. The first mapping is always for address 30140x00000000, with any additional banks following immediately to create 3015contiguous memory starting from 0. 3016 3017Then, the monitor installs itself at the upper end of the SDRAM area 3018and allocates memory for use by malloc() and for the global Board 3019Info data; also, the exception vector code is copied to the low RAM 3020pages, and the final stack is set up. 3021 3022Only after this relocation will you have a "normal" C environment; 3023until that you are restricted in several ways, mostly because you are 3024running from ROM, and because the code will have to be relocated to a 3025new address in RAM. 3026 3027 3028U-Boot Porting Guide: 3029---------------------- 3030 3031[Based on messages by Jerry Van Baren in the U-Boot-Users mailing 3032list, October 2002] 3033 3034 3035int main (int argc, char *argv[]) 3036{ 3037 sighandler_t no_more_time; 3038 3039 signal (SIGALRM, no_more_time); 3040 alarm (PROJECT_DEADLINE - toSec (3 * WEEK)); 3041 3042 if (available_money > available_manpower) { 3043 pay consultant to port U-Boot; 3044 return 0; 3045 } 3046 3047 Download latest U-Boot source; 3048 3049 Subscribe to u-boot-users mailing list; 3050 3051 if (clueless) { 3052 email ("Hi, I am new to U-Boot, how do I get started?"); 3053 } 3054 3055 while (learning) { 3056 Read the README file in the top level directory; 3057 Read http://www.denx.de/re/DPLG.html 3058 Read the source, Luke; 3059 } 3060 3061 if (available_money > toLocalCurrency ($2500)) { 3062 Buy a BDI2000; 3063 } else { 3064 Add a lot of aggravation and time; 3065 } 3066 3067 Create your own board support subdirectory; 3068 3069 Create your own board config file; 3070 3071 while (!running) { 3072 do { 3073 Add / modify source code; 3074 } until (compiles); 3075 Debug; 3076 if (clueless) 3077 email ("Hi, I am having problems..."); 3078 } 3079 Send patch file to Wolfgang; 3080 3081 return 0; 3082} 3083 3084void no_more_time (int sig) 3085{ 3086 hire_a_guru(); 3087} 3088 3089 3090Coding Standards: 3091----------------- 3092 3093All contributions to U-Boot should conform to the Linux kernel 3094coding style; see the file "Documentation/CodingStyle" in your Linux 3095kernel source directory. 3096 3097Please note that U-Boot is implemented in C (and to some small parts 3098in Assembler); no C++ is used, so please do not use C++ style 3099comments (//) in your code. 3100 3101Submissions which do not conform to the standards may be returned 3102with a request to reformat the changes. 3103 3104 3105Submitting Patches: 3106------------------- 3107 3108Since the number of patches for U-Boot is growing, we need to 3109establish some rules. Submissions which do not conform to these rules 3110may be rejected, even when they contain important and valuable stuff. 3111 3112 3113When you send a patch, please include the following information with 3114it: 3115 3116* For bug fixes: a description of the bug and how your patch fixes 3117 this bug. Please try to include a way of demonstrating that the 3118 patch actually fixes something. 3119 3120* For new features: a description of the feature and your 3121 implementation. 3122 3123* A CHANGELOG entry as plaintext (separate from the patch) 3124 3125* For major contributions, your entry to the CREDITS file 3126 3127* When you add support for a new board, don't forget to add this 3128 board to the MAKEALL script, too. 3129 3130* If your patch adds new configuration options, don't forget to 3131 document these in the README file. 3132 3133* The patch itself. If you are accessing the CVS repository use "cvs 3134 update; cvs diff -puRN"; else, use "diff -purN OLD NEW". If your 3135 version of diff does not support these options, then get the latest 3136 version of GNU diff. 3137 3138 The current directory when running this command shall be the top 3139 level directory of the U-Boot source tree, or it's parent directory 3140 (i. e. please make sure that your patch includes sufficient 3141 directory information for the affected files). 3142 3143 We accept patches as plain text, MIME attachments or as uuencoded 3144 gzipped text. 3145 3146* If one logical set of modifications affects or creates several 3147 files, all these changes shall be submitted in a SINGLE patch file. 3148 3149* Changesets that contain different, unrelated modifications shall be 3150 submitted as SEPARATE patches, one patch per changeset. 3151 3152 3153Notes: 3154 3155* Before sending the patch, run the MAKEALL script on your patched 3156 source tree and make sure that no errors or warnings are reported 3157 for any of the boards. 3158 3159* Keep your modifications to the necessary minimum: A patch 3160 containing several unrelated changes or arbitrary reformats will be 3161 returned with a request to re-formatting / split it. 3162 3163* If you modify existing code, make sure that your new code does not 3164 add to the memory footprint of the code ;-) Small is beautiful! 3165 When adding new features, these should compile conditionally only 3166 (using #ifdef), and the resulting code with the new feature 3167 disabled must not need more memory than the old code without your 3168 modification. 3169