1# 2# (C) Copyright 2000 - 2004 3# Wolfgang Denk, DENX Software Engineering, wd@denx.de. 4# 5# See file CREDITS for list of people who contributed to this 6# project. 7# 8# This program is free software; you can redistribute it and/or 9# modify it under the terms of the GNU General Public License as 10# published by the Free Software Foundation; either version 2 of 11# the License, or (at your option) any later version. 12# 13# This program is distributed in the hope that it will be useful, 14# but WITHOUT ANY WARRANTY; without even the implied warranty of 15# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 16# GNU General Public License for more details. 17# 18# You should have received a copy of the GNU General Public License 19# along with this program; if not, write to the Free Software 20# Foundation, Inc., 59 Temple Place, Suite 330, Boston, 21# MA 02111-1307 USA 22# 23 24Summary: 25======== 26 27This directory contains the source code for U-Boot, a boot loader for 28Embedded boards based on PowerPC and ARM processors, which can be 29installed in a boot ROM and used to initialize and test the hardware 30or to download and run application code. 31 32The development of U-Boot is closely related to Linux: some parts of 33the source code originate in the Linux source tree, we have some 34header files in common, and special provision has been made to 35support booting of Linux images. 36 37Some attention has been paid to make this software easily 38configurable and extendable. For instance, all monitor commands are 39implemented with the same call interface, so that it's very easy to 40add new commands. Also, instead of permanently adding rarely used 41code (for instance hardware test utilities) to the monitor, you can 42load and run it dynamically. 43 44 45Status: 46======= 47 48In general, all boards for which a configuration option exists in the 49Makefile have been tested to some extent and can be considered 50"working". In fact, many of them are used in production systems. 51 52In case of problems see the CHANGELOG and CREDITS files to find out 53who contributed the specific port. 54 55 56Where to get help: 57================== 58 59In case you have questions about, problems with or contributions for 60U-Boot you should send a message to the U-Boot mailing list at 61<u-boot-users@lists.sourceforge.net>. There is also an archive of 62previous traffic on the mailing list - please search the archive 63before asking FAQ's. Please see 64http://lists.sourceforge.net/lists/listinfo/u-boot-users/ 65 66 67Where we come from: 68=================== 69 70- start from 8xxrom sources 71- create PPCBoot project (http://sourceforge.net/projects/ppcboot) 72- clean up code 73- make it easier to add custom boards 74- make it possible to add other [PowerPC] CPUs 75- extend functions, especially: 76 * Provide extended interface to Linux boot loader 77 * S-Record download 78 * network boot 79 * PCMCIA / CompactFLash / ATA disk / SCSI ... boot 80- create ARMBoot project (http://sourceforge.net/projects/armboot) 81- add other CPU families (starting with ARM) 82- create U-Boot project (http://sourceforge.net/projects/u-boot) 83 84 85Names and Spelling: 86=================== 87 88The "official" name of this project is "Das U-Boot". The spelling 89"U-Boot" shall be used in all written text (documentation, comments 90in source files etc.). Example: 91 92 This is the README file for the U-Boot project. 93 94File names etc. shall be based on the string "u-boot". Examples: 95 96 include/asm-ppc/u-boot.h 97 98 #include <asm/u-boot.h> 99 100Variable names, preprocessor constants etc. shall be either based on 101the string "u_boot" or on "U_BOOT". Example: 102 103 U_BOOT_VERSION u_boot_logo 104 IH_OS_U_BOOT u_boot_hush_start 105 106 107Versioning: 108=========== 109 110U-Boot uses a 3 level version number containing a version, a 111sub-version, and a patchlevel: "U-Boot-2.34.5" means version "2", 112sub-version "34", and patchlevel "4". 113 114The patchlevel is used to indicate certain stages of development 115between released versions, i. e. officially released versions of 116U-Boot will always have a patchlevel of "0". 117 118 119Directory Hierarchy: 120==================== 121 122- board Board dependent files 123- common Misc architecture independent functions 124- cpu CPU specific files 125 - 74xx_7xx Files specific to Motorola MPC74xx and 7xx CPUs 126 - arm720t Files specific to ARM 720 CPUs 127 - arm920t Files specific to ARM 920 CPUs 128 - arm925t Files specific to ARM 925 CPUs 129 - arm926ejs Files specific to ARM 926 CPUs 130 - at91rm9200 Files specific to Atmel AT91RM9200 CPUs 131 - i386 Files specific to i386 CPUs 132 - ixp Files specific to Intel XScale IXP CPUs 133 - mcf52x2 Files specific to Motorola ColdFire MCF52x2 CPUs 134 - mips Files specific to MIPS CPUs 135 - mpc5xx Files specific to Motorola MPC5xx CPUs 136 - mpc5xxx Files specific to Motorola MPC5xxx CPUs 137 - mpc8xx Files specific to Motorola MPC8xx CPUs 138 - mpc824x Files specific to Motorola MPC824x CPUs 139 - mpc8260 Files specific to Motorola MPC8260 CPUs 140 - mpc85xx Files specific to Motorola MPC85xx CPUs 141 - nios Files specific to Altera NIOS CPUs 142 - ppc4xx Files specific to IBM PowerPC 4xx CPUs 143 - pxa Files specific to Intel XScale PXA CPUs 144 - s3c44b0 Files specific to Samsung S3C44B0 CPUs 145 - sa1100 Files specific to Intel StrongARM SA1100 CPUs 146- disk Code for disk drive partition handling 147- doc Documentation (don't expect too much) 148- drivers Commonly used device drivers 149- dtt Digital Thermometer and Thermostat drivers 150- examples Example code for standalone applications, etc. 151- include Header Files 152- lib_arm Files generic to ARM architecture 153- lib_generic Files generic to all architectures 154- lib_i386 Files generic to i386 architecture 155- lib_m68k Files generic to m68k architecture 156- lib_mips Files generic to MIPS architecture 157- lib_nios Files generic to NIOS architecture 158- lib_ppc Files generic to PowerPC architecture 159- net Networking code 160- post Power On Self Test 161- rtc Real Time Clock drivers 162- tools Tools to build S-Record or U-Boot images, etc. 163 164Software Configuration: 165======================= 166 167Configuration is usually done using C preprocessor defines; the 168rationale behind that is to avoid dead code whenever possible. 169 170There are two classes of configuration variables: 171 172* Configuration _OPTIONS_: 173 These are selectable by the user and have names beginning with 174 "CONFIG_". 175 176* Configuration _SETTINGS_: 177 These depend on the hardware etc. and should not be meddled with if 178 you don't know what you're doing; they have names beginning with 179 "CFG_". 180 181Later we will add a configuration tool - probably similar to or even 182identical to what's used for the Linux kernel. Right now, we have to 183do the configuration by hand, which means creating some symbolic 184links and editing some configuration files. We use the TQM8xxL boards 185as an example here. 186 187 188Selection of Processor Architecture and Board Type: 189--------------------------------------------------- 190 191For all supported boards there are ready-to-use default 192configurations available; just type "make <board_name>_config". 193 194Example: For a TQM823L module type: 195 196 cd u-boot 197 make TQM823L_config 198 199For the Cogent platform, you need to specify the cpu type as well; 200e.g. "make cogent_mpc8xx_config". And also configure the cogent 201directory according to the instructions in cogent/README. 202 203 204Configuration Options: 205---------------------- 206 207Configuration depends on the combination of board and CPU type; all 208such information is kept in a configuration file 209"include/configs/<board_name>.h". 210 211Example: For a TQM823L module, all configuration settings are in 212"include/configs/TQM823L.h". 213 214 215Many of the options are named exactly as the corresponding Linux 216kernel configuration options. The intention is to make it easier to 217build a config tool - later. 218 219 220The following options need to be configured: 221 222- CPU Type: Define exactly one of 223 224 PowerPC based CPUs: 225 ------------------- 226 CONFIG_MPC823, CONFIG_MPC850, CONFIG_MPC855, CONFIG_MPC860 227 or CONFIG_MPC5xx 228 or CONFIG_MPC824X, CONFIG_MPC8260 229 or CONFIG_MPC85xx 230 or CONFIG_IOP480 231 or CONFIG_405GP 232 or CONFIG_405EP 233 or CONFIG_440 234 or CONFIG_MPC74xx 235 or CONFIG_750FX 236 237 ARM based CPUs: 238 --------------- 239 CONFIG_SA1110 240 CONFIG_ARM7 241 CONFIG_PXA250 242 243 244- Board Type: Define exactly one of 245 246 PowerPC based boards: 247 --------------------- 248 249 CONFIG_ADCIOP, CONFIG_ICU862 CONFIG_RPXsuper, 250 CONFIG_ADS860, CONFIG_IP860, CONFIG_SM850, 251 CONFIG_AMX860, CONFIG_IPHASE4539, CONFIG_SPD823TS, 252 CONFIG_AR405, CONFIG_IVML24, CONFIG_SXNI855T, 253 CONFIG_BAB7xx, CONFIG_IVML24_128, CONFIG_Sandpoint8240, 254 CONFIG_CANBT, CONFIG_IVML24_256, CONFIG_Sandpoint8245, 255 CONFIG_CCM, CONFIG_IVMS8, CONFIG_TQM823L, 256 CONFIG_CPCI405, CONFIG_IVMS8_128, CONFIG_TQM850L, 257 CONFIG_CPCI4052, CONFIG_IVMS8_256, CONFIG_TQM855L, 258 CONFIG_CPCIISER4, CONFIG_LANTEC, CONFIG_TQM860L, 259 CONFIG_CPU86, CONFIG_MBX, CONFIG_TQM8260, 260 CONFIG_CRAYL1, CONFIG_MBX860T, CONFIG_TTTech, 261 CONFIG_CU824, CONFIG_MHPC, CONFIG_UTX8245, 262 CONFIG_DASA_SIM, CONFIG_MIP405, CONFIG_W7OLMC, 263 CONFIG_DU405, CONFIG_MOUSSE, CONFIG_W7OLMG, 264 CONFIG_ELPPC, CONFIG_MPC8260ADS, CONFIG_WALNUT405, 265 CONFIG_ERIC, CONFIG_MUSENKI, CONFIG_ZUMA, 266 CONFIG_ESTEEM192E, CONFIG_MVS1, CONFIG_c2mon, 267 CONFIG_ETX094, CONFIG_NX823, CONFIG_cogent_mpc8260, 268 CONFIG_EVB64260, CONFIG_OCRTC, CONFIG_cogent_mpc8xx, 269 CONFIG_FADS823, CONFIG_ORSG, CONFIG_ep8260, 270 CONFIG_FADS850SAR, CONFIG_OXC, CONFIG_gw8260, 271 CONFIG_FADS860T, CONFIG_PCI405, CONFIG_hermes, 272 CONFIG_FLAGADM, CONFIG_PCIPPC2, CONFIG_hymod, 273 CONFIG_FPS850L, CONFIG_PCIPPC6, CONFIG_lwmon, 274 CONFIG_GEN860T, CONFIG_PIP405, CONFIG_pcu_e, 275 CONFIG_GENIETV, CONFIG_PM826, CONFIG_ppmc8260, 276 CONFIG_GTH, CONFIG_RPXClassic, CONFIG_rsdproto, 277 CONFIG_IAD210, CONFIG_RPXlite, CONFIG_sbc8260, 278 CONFIG_EBONY, CONFIG_sacsng, CONFIG_FPS860L, 279 CONFIG_V37, CONFIG_ELPT860, CONFIG_CMI, 280 CONFIG_NETVIA, CONFIG_RBC823, CONFIG_ZPC1900, 281 CONFIG_MPC8540ADS, CONFIG_MPC8560ADS, CONFIG_QS850, 282 CONFIG_QS823, CONFIG_QS860T, CONFIG_DB64360, 283 CONFIG_DB64460, CONFIG_DUET_ADS CONFIG_NETTA 284 CONFIG_NETPHONE 285 286 ARM based boards: 287 ----------------- 288 289 CONFIG_HHP_CRADLE, CONFIG_DNP1110, CONFIG_EP7312, 290 CONFIG_IMPA7, CONFIG_LART, CONFIG_LUBBOCK, 291 CONFIG_INNOVATOROMAP1510, CONFIG_INNOVATOROMAP1610, 292 CONFIG_H2_OMAP1610, CONFIG_SHANNON, CONFIG_SMDK2400, 293 CONFIG_SMDK2410, CONFIG_TRAB, CONFIG_VCMA9, 294 CONFIG_AT91RM9200DK 295 296 297- CPU Module Type: (if CONFIG_COGENT is defined) 298 Define exactly one of 299 CONFIG_CMA286_60_OLD 300--- FIXME --- not tested yet: 301 CONFIG_CMA286_60, CONFIG_CMA286_21, CONFIG_CMA286_60P, 302 CONFIG_CMA287_23, CONFIG_CMA287_50 303 304- Motherboard Type: (if CONFIG_COGENT is defined) 305 Define exactly one of 306 CONFIG_CMA101, CONFIG_CMA102 307 308- Motherboard I/O Modules: (if CONFIG_COGENT is defined) 309 Define one or more of 310 CONFIG_CMA302 311 312- Motherboard Options: (if CONFIG_CMA101 or CONFIG_CMA102 are defined) 313 Define one or more of 314 CONFIG_LCD_HEARTBEAT - update a character position on 315 the lcd display every second with 316 a "rotator" |\-/|\-/ 317 318- Board flavour: (if CONFIG_MPC8260ADS is defined) 319 CONFIG_ADSTYPE 320 Possible values are: 321 CFG_8260ADS - original MPC8260ADS 322 CFG_8266ADS - MPC8266ADS 323 CFG_PQ2FADS - PQ2FADS-ZU or PQ2FADS-VR 324 CFG_8272ADS - MPC8272ADS 325 326- MPC824X Family Member (if CONFIG_MPC824X is defined) 327 Define exactly one of 328 CONFIG_MPC8240, CONFIG_MPC8245 329 330- 8xx CPU Options: (if using an MPC8xx cpu) 331 Define one or more of 332 CONFIG_8xx_GCLK_FREQ - if get_gclk_freq() cannot work 333 e.g. if there is no 32KHz 334 reference PIT/RTC clock 335 336- 859/866 CPU options: (if using a MPC859 or MPC866 CPU): 337 CFG_866_OSCCLK 338 CFG_866_CPUCLK_MIN 339 CFG_866_CPUCLK_MAX 340 CFG_866_CPUCLK_DEFAULT 341 See doc/README.MPC866 342 343 CFG_MEASURE_CPUCLK 344 345 Define this to measure the actual CPU clock instead 346 of relying on the correctness of the configured 347 values. Mostly useful for board bringup to make sure 348 the PLL is locked at the intended frequency. Note 349 that this requires a (stable) reference clock (32 kHz 350 RTC clock), 351 352- Linux Kernel Interface: 353 CONFIG_CLOCKS_IN_MHZ 354 355 U-Boot stores all clock information in Hz 356 internally. For binary compatibility with older Linux 357 kernels (which expect the clocks passed in the 358 bd_info data to be in MHz) the environment variable 359 "clocks_in_mhz" can be defined so that U-Boot 360 converts clock data to MHZ before passing it to the 361 Linux kernel. 362 When CONFIG_CLOCKS_IN_MHZ is defined, a definition of 363 "clocks_in_mhz=1" is automatically included in the 364 default environment. 365 366 CONFIG_MEMSIZE_IN_BYTES [relevant for MIPS only] 367 368 When transfering memsize parameter to linux, some versions 369 expect it to be in bytes, others in MB. 370 Define CONFIG_MEMSIZE_IN_BYTES to make it in bytes. 371 372- Console Interface: 373 Depending on board, define exactly one serial port 374 (like CONFIG_8xx_CONS_SMC1, CONFIG_8xx_CONS_SMC2, 375 CONFIG_8xx_CONS_SCC1, ...), or switch off the serial 376 console by defining CONFIG_8xx_CONS_NONE 377 378 Note: if CONFIG_8xx_CONS_NONE is defined, the serial 379 port routines must be defined elsewhere 380 (i.e. serial_init(), serial_getc(), ...) 381 382 CONFIG_CFB_CONSOLE 383 Enables console device for a color framebuffer. Needs following 384 defines (cf. smiLynxEM, i8042, board/eltec/bab7xx) 385 VIDEO_FB_LITTLE_ENDIAN graphic memory organisation 386 (default big endian) 387 VIDEO_HW_RECTFILL graphic chip supports 388 rectangle fill 389 (cf. smiLynxEM) 390 VIDEO_HW_BITBLT graphic chip supports 391 bit-blit (cf. smiLynxEM) 392 VIDEO_VISIBLE_COLS visible pixel columns 393 (cols=pitch) 394 VIDEO_VISIBLE_ROWS visible pixel rows 395 VIDEO_PIXEL_SIZE bytes per pixel 396 VIDEO_DATA_FORMAT graphic data format 397 (0-5, cf. cfb_console.c) 398 VIDEO_FB_ADRS framebuffer address 399 VIDEO_KBD_INIT_FCT keyboard int fct 400 (i.e. i8042_kbd_init()) 401 VIDEO_TSTC_FCT test char fct 402 (i.e. i8042_tstc) 403 VIDEO_GETC_FCT get char fct 404 (i.e. i8042_getc) 405 CONFIG_CONSOLE_CURSOR cursor drawing on/off 406 (requires blink timer 407 cf. i8042.c) 408 CFG_CONSOLE_BLINK_COUNT blink interval (cf. i8042.c) 409 CONFIG_CONSOLE_TIME display time/date info in 410 upper right corner 411 (requires CFG_CMD_DATE) 412 CONFIG_VIDEO_LOGO display Linux logo in 413 upper left corner 414 CONFIG_VIDEO_BMP_LOGO use bmp_logo.h instead of 415 linux_logo.h for logo. 416 Requires CONFIG_VIDEO_LOGO 417 CONFIG_CONSOLE_EXTRA_INFO 418 addional board info beside 419 the logo 420 421 When CONFIG_CFB_CONSOLE is defined, video console is 422 default i/o. Serial console can be forced with 423 environment 'console=serial'. 424 425 When CONFIG_SILENT_CONSOLE is defined, all console 426 messages (by U-Boot and Linux!) can be silenced with 427 the "silent" environment variable. See 428 doc/README.silent for more information. 429 430- Console Baudrate: 431 CONFIG_BAUDRATE - in bps 432 Select one of the baudrates listed in 433 CFG_BAUDRATE_TABLE, see below. 434 CFG_BRGCLK_PRESCALE, baudrate prescale 435 436- Interrupt driven serial port input: 437 CONFIG_SERIAL_SOFTWARE_FIFO 438 439 PPC405GP only. 440 Use an interrupt handler for receiving data on the 441 serial port. It also enables using hardware handshake 442 (RTS/CTS) and UART's built-in FIFO. Set the number of 443 bytes the interrupt driven input buffer should have. 444 445 Leave undefined to disable this feature, including 446 disable the buffer and hardware handshake. 447 448- Console UART Number: 449 CONFIG_UART1_CONSOLE 450 451 IBM PPC4xx only. 452 If defined internal UART1 (and not UART0) is used 453 as default U-Boot console. 454 455- Boot Delay: CONFIG_BOOTDELAY - in seconds 456 Delay before automatically booting the default image; 457 set to -1 to disable autoboot. 458 459 See doc/README.autoboot for these options that 460 work with CONFIG_BOOTDELAY. None are required. 461 CONFIG_BOOT_RETRY_TIME 462 CONFIG_BOOT_RETRY_MIN 463 CONFIG_AUTOBOOT_KEYED 464 CONFIG_AUTOBOOT_PROMPT 465 CONFIG_AUTOBOOT_DELAY_STR 466 CONFIG_AUTOBOOT_STOP_STR 467 CONFIG_AUTOBOOT_DELAY_STR2 468 CONFIG_AUTOBOOT_STOP_STR2 469 CONFIG_ZERO_BOOTDELAY_CHECK 470 CONFIG_RESET_TO_RETRY 471 472- Autoboot Command: 473 CONFIG_BOOTCOMMAND 474 Only needed when CONFIG_BOOTDELAY is enabled; 475 define a command string that is automatically executed 476 when no character is read on the console interface 477 within "Boot Delay" after reset. 478 479 CONFIG_BOOTARGS 480 This can be used to pass arguments to the bootm 481 command. The value of CONFIG_BOOTARGS goes into the 482 environment value "bootargs". 483 484 CONFIG_RAMBOOT and CONFIG_NFSBOOT 485 The value of these goes into the environment as 486 "ramboot" and "nfsboot" respectively, and can be used 487 as a convenience, when switching between booting from 488 ram and nfs. 489 490- Pre-Boot Commands: 491 CONFIG_PREBOOT 492 493 When this option is #defined, the existence of the 494 environment variable "preboot" will be checked 495 immediately before starting the CONFIG_BOOTDELAY 496 countdown and/or running the auto-boot command resp. 497 entering interactive mode. 498 499 This feature is especially useful when "preboot" is 500 automatically generated or modified. For an example 501 see the LWMON board specific code: here "preboot" is 502 modified when the user holds down a certain 503 combination of keys on the (special) keyboard when 504 booting the systems 505 506- Serial Download Echo Mode: 507 CONFIG_LOADS_ECHO 508 If defined to 1, all characters received during a 509 serial download (using the "loads" command) are 510 echoed back. This might be needed by some terminal 511 emulations (like "cu"), but may as well just take 512 time on others. This setting #define's the initial 513 value of the "loads_echo" environment variable. 514 515- Kgdb Serial Baudrate: (if CFG_CMD_KGDB is defined) 516 CONFIG_KGDB_BAUDRATE 517 Select one of the baudrates listed in 518 CFG_BAUDRATE_TABLE, see below. 519 520- Monitor Functions: 521 CONFIG_COMMANDS 522 Most monitor functions can be selected (or 523 de-selected) by adjusting the definition of 524 CONFIG_COMMANDS; to select individual functions, 525 #define CONFIG_COMMANDS by "OR"ing any of the 526 following values: 527 528 #define enables commands: 529 ------------------------- 530 CFG_CMD_ASKENV * ask for env variable 531 CFG_CMD_AUTOSCRIPT Autoscript Support 532 CFG_CMD_BDI bdinfo 533 CFG_CMD_BEDBUG Include BedBug Debugger 534 CFG_CMD_BMP * BMP support 535 CFG_CMD_BOOTD bootd 536 CFG_CMD_CACHE icache, dcache 537 CFG_CMD_CONSOLE coninfo 538 CFG_CMD_DATE * support for RTC, date/time... 539 CFG_CMD_DHCP DHCP support 540 CFG_CMD_DIAG * Diagnostics 541 CFG_CMD_DOC * Disk-On-Chip Support 542 CFG_CMD_DTT Digital Therm and Thermostat 543 CFG_CMD_ECHO * echo arguments 544 CFG_CMD_EEPROM * EEPROM read/write support 545 CFG_CMD_ELF bootelf, bootvx 546 CFG_CMD_ENV saveenv 547 CFG_CMD_FDC * Floppy Disk Support 548 CFG_CMD_FAT FAT partition support 549 CFG_CMD_FDOS * Dos diskette Support 550 CFG_CMD_FLASH flinfo, erase, protect 551 CFG_CMD_FPGA FPGA device initialization support 552 CFG_CMD_HWFLOW * RTS/CTS hw flow control 553 CFG_CMD_I2C * I2C serial bus support 554 CFG_CMD_IDE * IDE harddisk support 555 CFG_CMD_IMI iminfo 556 CFG_CMD_IMLS List all found images 557 CFG_CMD_IMMAP * IMMR dump support 558 CFG_CMD_IRQ * irqinfo 559 CFG_CMD_ITEST * Integer/string test of 2 values 560 CFG_CMD_JFFS2 * JFFS2 Support 561 CFG_CMD_KGDB * kgdb 562 CFG_CMD_LOADB loadb 563 CFG_CMD_LOADS loads 564 CFG_CMD_MEMORY md, mm, nm, mw, cp, cmp, crc, base, 565 loop, mtest 566 CFG_CMD_MISC Misc functions like sleep etc 567 CFG_CMD_MMC MMC memory mapped support 568 CFG_CMD_MII MII utility commands 569 CFG_CMD_NAND * NAND support 570 CFG_CMD_NET bootp, tftpboot, rarpboot 571 CFG_CMD_PCI * pciinfo 572 CFG_CMD_PCMCIA * PCMCIA support 573 CFG_CMD_PING * send ICMP ECHO_REQUEST to network host 574 CFG_CMD_PORTIO * Port I/O 575 CFG_CMD_REGINFO * Register dump 576 CFG_CMD_RUN run command in env variable 577 CFG_CMD_SAVES save S record dump 578 CFG_CMD_SCSI * SCSI Support 579 CFG_CMD_SDRAM * print SDRAM configuration information 580 CFG_CMD_SETGETDCR Support for DCR Register access (4xx only) 581 CFG_CMD_SPI * SPI serial bus support 582 CFG_CMD_USB * USB support 583 CFG_CMD_VFD * VFD support (TRAB) 584 CFG_CMD_BSP * Board SPecific functions 585 CFG_CMD_CDP * Cisco Discover Protocol support 586 ----------------------------------------------- 587 CFG_CMD_ALL all 588 589 CFG_CMD_DFL Default configuration; at the moment 590 this is includes all commands, except 591 the ones marked with "*" in the list 592 above. 593 594 If you don't define CONFIG_COMMANDS it defaults to 595 CFG_CMD_DFL in include/cmd_confdefs.h. A board can 596 override the default settings in the respective 597 include file. 598 599 EXAMPLE: If you want all functions except of network 600 support you can write: 601 602 #define CONFIG_COMMANDS (CFG_CMD_ALL & ~CFG_CMD_NET) 603 604 605 Note: Don't enable the "icache" and "dcache" commands 606 (configuration option CFG_CMD_CACHE) unless you know 607 what you (and your U-Boot users) are doing. Data 608 cache cannot be enabled on systems like the 8xx or 609 8260 (where accesses to the IMMR region must be 610 uncached), and it cannot be disabled on all other 611 systems where we (mis-) use the data cache to hold an 612 initial stack and some data. 613 614 615 XXX - this list needs to get updated! 616 617- Watchdog: 618 CONFIG_WATCHDOG 619 If this variable is defined, it enables watchdog 620 support. There must be support in the platform specific 621 code for a watchdog. For the 8xx and 8260 CPUs, the 622 SIU Watchdog feature is enabled in the SYPCR 623 register. 624 625- U-Boot Version: 626 CONFIG_VERSION_VARIABLE 627 If this variable is defined, an environment variable 628 named "ver" is created by U-Boot showing the U-Boot 629 version as printed by the "version" command. 630 This variable is readonly. 631 632- Real-Time Clock: 633 634 When CFG_CMD_DATE is selected, the type of the RTC 635 has to be selected, too. Define exactly one of the 636 following options: 637 638 CONFIG_RTC_MPC8xx - use internal RTC of MPC8xx 639 CONFIG_RTC_PCF8563 - use Philips PCF8563 RTC 640 CONFIG_RTC_MC146818 - use MC146818 RTC 641 CONFIG_RTC_DS1307 - use Maxim, Inc. DS1307 RTC 642 CONFIG_RTC_DS1337 - use Maxim, Inc. DS1337 RTC 643 CONFIG_RTC_DS1338 - use Maxim, Inc. DS1338 RTC 644 CONFIG_RTC_DS164x - use Dallas DS164x RTC 645 646 Note that if the RTC uses I2C, then the I2C interface 647 must also be configured. See I2C Support, below. 648 649- Timestamp Support: 650 651 When CONFIG_TIMESTAMP is selected, the timestamp 652 (date and time) of an image is printed by image 653 commands like bootm or iminfo. This option is 654 automatically enabled when you select CFG_CMD_DATE . 655 656- Partition Support: 657 CONFIG_MAC_PARTITION and/or CONFIG_DOS_PARTITION 658 and/or CONFIG_ISO_PARTITION 659 660 If IDE or SCSI support is enabled (CFG_CMD_IDE or 661 CFG_CMD_SCSI) you must configure support for at least 662 one partition type as well. 663 664- IDE Reset method: 665 CONFIG_IDE_RESET_ROUTINE - this is defined in several 666 board configurations files but used nowhere! 667 668 CONFIG_IDE_RESET - is this is defined, IDE Reset will 669 be performed by calling the function 670 ide_set_reset(int reset) 671 which has to be defined in a board specific file 672 673- ATAPI Support: 674 CONFIG_ATAPI 675 676 Set this to enable ATAPI support. 677 678- LBA48 Support 679 CONFIG_LBA48 680 681 Set this to enable support for disks larger than 137GB 682 Also look at CFG_64BIT_LBA ,CFG_64BIT_VSPRINTF and CFG_64BIT_STRTOUL 683 Whithout these , LBA48 support uses 32bit variables and will 'only' 684 support disks up to 2.1TB. 685 686 CFG_64BIT_LBA: 687 When enabled, makes the IDE subsystem use 64bit sector addresses. 688 Default is 32bit. 689 690- SCSI Support: 691 At the moment only there is only support for the 692 SYM53C8XX SCSI controller; define 693 CONFIG_SCSI_SYM53C8XX to enable it. 694 695 CFG_SCSI_MAX_LUN [8], CFG_SCSI_MAX_SCSI_ID [7] and 696 CFG_SCSI_MAX_DEVICE [CFG_SCSI_MAX_SCSI_ID * 697 CFG_SCSI_MAX_LUN] can be adjusted to define the 698 maximum numbers of LUNs, SCSI ID's and target 699 devices. 700 CFG_SCSI_SYM53C8XX_CCF to fix clock timing (80Mhz) 701 702- NETWORK Support (PCI): 703 CONFIG_E1000 704 Support for Intel 8254x gigabit chips. 705 706 CONFIG_EEPRO100 707 Support for Intel 82557/82559/82559ER chips. 708 Optional CONFIG_EEPRO100_SROM_WRITE enables eeprom 709 write routine for first time initialisation. 710 711 CONFIG_TULIP 712 Support for Digital 2114x chips. 713 Optional CONFIG_TULIP_SELECT_MEDIA for board specific 714 modem chip initialisation (KS8761/QS6611). 715 716 CONFIG_NATSEMI 717 Support for National dp83815 chips. 718 719 CONFIG_NS8382X 720 Support for National dp8382[01] gigabit chips. 721 722- NETWORK Support (other): 723 724 CONFIG_DRIVER_LAN91C96 725 Support for SMSC's LAN91C96 chips. 726 727 CONFIG_LAN91C96_BASE 728 Define this to hold the physical address 729 of the LAN91C96's I/O space 730 731 CONFIG_LAN91C96_USE_32_BIT 732 Define this to enable 32 bit addressing 733 734- USB Support: 735 At the moment only the UHCI host controller is 736 supported (PIP405, MIP405, MPC5200); define 737 CONFIG_USB_UHCI to enable it. 738 define CONFIG_USB_KEYBOARD to enable the USB Keyboard 739 end define CONFIG_USB_STORAGE to enable the USB 740 storage devices. 741 Note: 742 Supported are USB Keyboards and USB Floppy drives 743 (TEAC FD-05PUB). 744 MPC5200 USB requires additional defines: 745 CONFIG_USB_CLOCK 746 for 528 MHz Clock: 0x0001bbbb 747 CONFIG_USB_CONFIG 748 for differential drivers: 0x00001000 749 for single ended drivers: 0x00005000 750 751 752- MMC Support: 753 The MMC controller on the Intel PXA is supported. To 754 enable this define CONFIG_MMC. The MMC can be 755 accessed from the boot prompt by mapping the device 756 to physical memory similar to flash. Command line is 757 enabled with CFG_CMD_MMC. The MMC driver also works with 758 the FAT fs. This is enabled with CFG_CMD_FAT. 759 760- Keyboard Support: 761 CONFIG_ISA_KEYBOARD 762 763 Define this to enable standard (PC-Style) keyboard 764 support 765 766 CONFIG_I8042_KBD 767 Standard PC keyboard driver with US (is default) and 768 GERMAN key layout (switch via environment 'keymap=de') support. 769 Export function i8042_kbd_init, i8042_tstc and i8042_getc 770 for cfb_console. Supports cursor blinking. 771 772- Video support: 773 CONFIG_VIDEO 774 775 Define this to enable video support (for output to 776 video). 777 778 CONFIG_VIDEO_CT69000 779 780 Enable Chips & Technologies 69000 Video chip 781 782 CONFIG_VIDEO_SMI_LYNXEM 783 Enable Silicon Motion SMI 712/710/810 Video chip. The 784 video output is selected via environment 'videoout' 785 (1 = LCD and 2 = CRT). If videoout is undefined, CRT is 786 assumed. 787 788 For the CT69000 and SMI_LYNXEM drivers, videomode is 789 selected via environment 'videomode'. Two diferent ways 790 are possible: 791 - "videomode=num" 'num' is a standard LiLo mode numbers. 792 Following standard modes are supported (* is default): 793 794 Colors 640x480 800x600 1024x768 1152x864 1280x1024 795 -------------+--------------------------------------------- 796 8 bits | 0x301* 0x303 0x305 0x161 0x307 797 15 bits | 0x310 0x313 0x316 0x162 0x319 798 16 bits | 0x311 0x314 0x317 0x163 0x31A 799 24 bits | 0x312 0x315 0x318 ? 0x31B 800 -------------+--------------------------------------------- 801 (i.e. setenv videomode 317; saveenv; reset;) 802 803 - "videomode=bootargs" all the video parameters are parsed 804 from the bootargs. (See drivers/videomodes.c) 805 806 807 CONFIG_VIDEO_SED13806 808 Enable Epson SED13806 driver. This driver supports 8bpp 809 and 16bpp modes defined by CONFIG_VIDEO_SED13806_8BPP 810 or CONFIG_VIDEO_SED13806_16BPP 811 812- Keyboard Support: 813 CONFIG_KEYBOARD 814 815 Define this to enable a custom keyboard support. 816 This simply calls drv_keyboard_init() which must be 817 defined in your board-specific files. 818 The only board using this so far is RBC823. 819 820- LCD Support: CONFIG_LCD 821 822 Define this to enable LCD support (for output to LCD 823 display); also select one of the supported displays 824 by defining one of these: 825 826 CONFIG_NEC_NL6448AC33: 827 828 NEC NL6448AC33-18. Active, color, single scan. 829 830 CONFIG_NEC_NL6448BC20 831 832 NEC NL6448BC20-08. 6.5", 640x480. 833 Active, color, single scan. 834 835 CONFIG_NEC_NL6448BC33_54 836 837 NEC NL6448BC33-54. 10.4", 640x480. 838 Active, color, single scan. 839 840 CONFIG_SHARP_16x9 841 842 Sharp 320x240. Active, color, single scan. 843 It isn't 16x9, and I am not sure what it is. 844 845 CONFIG_SHARP_LQ64D341 846 847 Sharp LQ64D341 display, 640x480. 848 Active, color, single scan. 849 850 CONFIG_HLD1045 851 852 HLD1045 display, 640x480. 853 Active, color, single scan. 854 855 CONFIG_OPTREX_BW 856 857 Optrex CBL50840-2 NF-FW 99 22 M5 858 or 859 Hitachi LMG6912RPFC-00T 860 or 861 Hitachi SP14Q002 862 863 320x240. Black & white. 864 865 Normally display is black on white background; define 866 CFG_WHITE_ON_BLACK to get it inverted. 867 868- Splash Screen Support: CONFIG_SPLASH_SCREEN 869 870 If this option is set, the environment is checked for 871 a variable "splashimage". If found, the usual display 872 of logo, copyright and system information on the LCD 873 is supressed and the BMP image at the address 874 specified in "splashimage" is loaded instead. The 875 console is redirected to the "nulldev", too. This 876 allows for a "silent" boot where a splash screen is 877 loaded very quickly after power-on. 878 879- Compression support: 880 CONFIG_BZIP2 881 882 If this option is set, support for bzip2 compressed 883 images is included. If not, only uncompressed and gzip 884 compressed images are supported. 885 886 NOTE: the bzip2 algorithm requires a lot of RAM, so 887 the malloc area (as defined by CFG_MALLOC_LEN) should 888 be at least 4MB. 889 890- Ethernet address: 891 CONFIG_ETHADDR 892 CONFIG_ETH2ADDR 893 CONFIG_ETH3ADDR 894 895 Define a default value for ethernet address to use 896 for the respective ethernet interface, in case this 897 is not determined automatically. 898 899- IP address: 900 CONFIG_IPADDR 901 902 Define a default value for the IP address to use for 903 the default ethernet interface, in case this is not 904 determined through e.g. bootp. 905 906- Server IP address: 907 CONFIG_SERVERIP 908 909 Defines a default value for theIP address of a TFTP 910 server to contact when using the "tftboot" command. 911 912- BOOTP Recovery Mode: 913 CONFIG_BOOTP_RANDOM_DELAY 914 915 If you have many targets in a network that try to 916 boot using BOOTP, you may want to avoid that all 917 systems send out BOOTP requests at precisely the same 918 moment (which would happen for instance at recovery 919 from a power failure, when all systems will try to 920 boot, thus flooding the BOOTP server. Defining 921 CONFIG_BOOTP_RANDOM_DELAY causes a random delay to be 922 inserted before sending out BOOTP requests. The 923 following delays are insterted then: 924 925 1st BOOTP request: delay 0 ... 1 sec 926 2nd BOOTP request: delay 0 ... 2 sec 927 3rd BOOTP request: delay 0 ... 4 sec 928 4th and following 929 BOOTP requests: delay 0 ... 8 sec 930 931- DHCP Advanced Options: 932 CONFIG_BOOTP_MASK 933 934 You can fine tune the DHCP functionality by adding 935 these flags to the CONFIG_BOOTP_MASK define: 936 937 CONFIG_BOOTP_DNS2 - If a DHCP client requests the DNS 938 serverip from a DHCP server, it is possible that more 939 than one DNS serverip is offered to the client. 940 If CONFIG_BOOTP_DNS2 is enabled, the secondary DNS 941 serverip will be stored in the additional environment 942 variable "dnsip2". The first DNS serverip is always 943 stored in the variable "dnsip", when CONFIG_BOOTP_DNS 944 is added to the CONFIG_BOOTP_MASK. 945 946 CONFIG_BOOTP_SEND_HOSTNAME - Some DHCP servers are capable 947 to do a dynamic update of a DNS server. To do this, they 948 need the hostname of the DHCP requester. 949 If CONFIG_BOOP_SEND_HOSTNAME is added to the 950 CONFIG_BOOTP_MASK, the content of the "hostname" 951 environment variable is passed as option 12 to 952 the DHCP server. 953 954 - CDP Options: 955 CONFIG_CDP_DEVICE_ID 956 957 The device id used in CDP trigger frames. 958 959 CONFIG_CDP_DEVICE_ID_PREFIX 960 961 A two character string which is prefixed to the MAC address 962 of the device. 963 964 CONFIG_CDP_PORT_ID 965 966 A printf format string which contains the ascii name of 967 the port. Normally is set to "eth%d" which sets 968 eth0 for the first ethernet, eth1 for the second etc. 969 970 CONFIG_CDP_CAPABILITIES 971 972 A 32bit integer which indicates the device capabilities; 973 0x00000010 for a normal host which does not forwards. 974 975 CONFIG_CDP_VERSION 976 977 An ascii string containing the version of the software. 978 979 CONFIG_CDP_PLATFORM 980 981 An ascii string containing the name of the platform. 982 983 CONFIG_CDP_TRIGGER 984 985 A 32bit integer sent on the trigger. 986 987 CONFIG_CDP_POWER_CONSUMPTION 988 989 A 16bit integer containing the power consumption of the 990 device in .1 of milliwatts. 991 992 CONFIG_CDP_APPLIANCE_VLAN_TYPE 993 994 A byte containing the id of the VLAN. 995 996- Status LED: CONFIG_STATUS_LED 997 998 Several configurations allow to display the current 999 status using a LED. For instance, the LED will blink 1000 fast while running U-Boot code, stop blinking as 1001 soon as a reply to a BOOTP request was received, and 1002 start blinking slow once the Linux kernel is running 1003 (supported by a status LED driver in the Linux 1004 kernel). Defining CONFIG_STATUS_LED enables this 1005 feature in U-Boot. 1006 1007- CAN Support: CONFIG_CAN_DRIVER 1008 1009 Defining CONFIG_CAN_DRIVER enables CAN driver support 1010 on those systems that support this (optional) 1011 feature, like the TQM8xxL modules. 1012 1013- I2C Support: CONFIG_HARD_I2C | CONFIG_SOFT_I2C 1014 1015 These enable I2C serial bus commands. Defining either of 1016 (but not both of) CONFIG_HARD_I2C or CONFIG_SOFT_I2C will 1017 include the appropriate I2C driver for the selected cpu. 1018 1019 This will allow you to use i2c commands at the u-boot 1020 command line (as long as you set CFG_CMD_I2C in 1021 CONFIG_COMMANDS) and communicate with i2c based realtime 1022 clock chips. See common/cmd_i2c.c for a description of the 1023 command line interface. 1024 1025 CONFIG_HARD_I2C selects the CPM hardware driver for I2C. 1026 1027 CONFIG_SOFT_I2C configures u-boot to use a software (aka 1028 bit-banging) driver instead of CPM or similar hardware 1029 support for I2C. 1030 1031 There are several other quantities that must also be 1032 defined when you define CONFIG_HARD_I2C or CONFIG_SOFT_I2C. 1033 1034 In both cases you will need to define CFG_I2C_SPEED 1035 to be the frequency (in Hz) at which you wish your i2c bus 1036 to run and CFG_I2C_SLAVE to be the address of this node (ie 1037 the cpu's i2c node address). 1038 1039 Now, the u-boot i2c code for the mpc8xx (cpu/mpc8xx/i2c.c) 1040 sets the cpu up as a master node and so its address should 1041 therefore be cleared to 0 (See, eg, MPC823e User's Manual 1042 p.16-473). So, set CFG_I2C_SLAVE to 0. 1043 1044 That's all that's required for CONFIG_HARD_I2C. 1045 1046 If you use the software i2c interface (CONFIG_SOFT_I2C) 1047 then the following macros need to be defined (examples are 1048 from include/configs/lwmon.h): 1049 1050 I2C_INIT 1051 1052 (Optional). Any commands necessary to enable the I2C 1053 controller or configure ports. 1054 1055 eg: #define I2C_INIT (immr->im_cpm.cp_pbdir |= PB_SCL) 1056 1057 I2C_PORT 1058 1059 (Only for MPC8260 CPU). The I/O port to use (the code 1060 assumes both bits are on the same port). Valid values 1061 are 0..3 for ports A..D. 1062 1063 I2C_ACTIVE 1064 1065 The code necessary to make the I2C data line active 1066 (driven). If the data line is open collector, this 1067 define can be null. 1068 1069 eg: #define I2C_ACTIVE (immr->im_cpm.cp_pbdir |= PB_SDA) 1070 1071 I2C_TRISTATE 1072 1073 The code necessary to make the I2C data line tri-stated 1074 (inactive). If the data line is open collector, this 1075 define can be null. 1076 1077 eg: #define I2C_TRISTATE (immr->im_cpm.cp_pbdir &= ~PB_SDA) 1078 1079 I2C_READ 1080 1081 Code that returns TRUE if the I2C data line is high, 1082 FALSE if it is low. 1083 1084 eg: #define I2C_READ ((immr->im_cpm.cp_pbdat & PB_SDA) != 0) 1085 1086 I2C_SDA(bit) 1087 1088 If <bit> is TRUE, sets the I2C data line high. If it 1089 is FALSE, it clears it (low). 1090 1091 eg: #define I2C_SDA(bit) \ 1092 if(bit) immr->im_cpm.cp_pbdat |= PB_SDA; \ 1093 else immr->im_cpm.cp_pbdat &= ~PB_SDA 1094 1095 I2C_SCL(bit) 1096 1097 If <bit> is TRUE, sets the I2C clock line high. If it 1098 is FALSE, it clears it (low). 1099 1100 eg: #define I2C_SCL(bit) \ 1101 if(bit) immr->im_cpm.cp_pbdat |= PB_SCL; \ 1102 else immr->im_cpm.cp_pbdat &= ~PB_SCL 1103 1104 I2C_DELAY 1105 1106 This delay is invoked four times per clock cycle so this 1107 controls the rate of data transfer. The data rate thus 1108 is 1 / (I2C_DELAY * 4). Often defined to be something 1109 like: 1110 1111 #define I2C_DELAY udelay(2) 1112 1113 CFG_I2C_INIT_BOARD 1114 1115 When a board is reset during an i2c bus transfer 1116 chips might think that the current transfer is still 1117 in progress. On some boards it is possible to access 1118 the i2c SCLK line directly, either by using the 1119 processor pin as a GPIO or by having a second pin 1120 connected to the bus. If this option is defined a 1121 custom i2c_init_board() routine in boards/xxx/board.c 1122 is run early in the boot sequence. 1123 1124- SPI Support: CONFIG_SPI 1125 1126 Enables SPI driver (so far only tested with 1127 SPI EEPROM, also an instance works with Crystal A/D and 1128 D/As on the SACSng board) 1129 1130 CONFIG_SPI_X 1131 1132 Enables extended (16-bit) SPI EEPROM addressing. 1133 (symmetrical to CONFIG_I2C_X) 1134 1135 CONFIG_SOFT_SPI 1136 1137 Enables a software (bit-bang) SPI driver rather than 1138 using hardware support. This is a general purpose 1139 driver that only requires three general I/O port pins 1140 (two outputs, one input) to function. If this is 1141 defined, the board configuration must define several 1142 SPI configuration items (port pins to use, etc). For 1143 an example, see include/configs/sacsng.h. 1144 1145- FPGA Support: CONFIG_FPGA_COUNT 1146 1147 Specify the number of FPGA devices to support. 1148 1149 CONFIG_FPGA 1150 1151 Used to specify the types of FPGA devices. For example, 1152 #define CONFIG_FPGA CFG_XILINX_VIRTEX2 1153 1154 CFG_FPGA_PROG_FEEDBACK 1155 1156 Enable printing of hash marks during FPGA configuration. 1157 1158 CFG_FPGA_CHECK_BUSY 1159 1160 Enable checks on FPGA configuration interface busy 1161 status by the configuration function. This option 1162 will require a board or device specific function to 1163 be written. 1164 1165 CONFIG_FPGA_DELAY 1166 1167 If defined, a function that provides delays in the FPGA 1168 configuration driver. 1169 1170 CFG_FPGA_CHECK_CTRLC 1171 Allow Control-C to interrupt FPGA configuration 1172 1173 CFG_FPGA_CHECK_ERROR 1174 1175 Check for configuration errors during FPGA bitfile 1176 loading. For example, abort during Virtex II 1177 configuration if the INIT_B line goes low (which 1178 indicated a CRC error). 1179 1180 CFG_FPGA_WAIT_INIT 1181 1182 Maximum time to wait for the INIT_B line to deassert 1183 after PROB_B has been deasserted during a Virtex II 1184 FPGA configuration sequence. The default time is 500 1185 mS. 1186 1187 CFG_FPGA_WAIT_BUSY 1188 1189 Maximum time to wait for BUSY to deassert during 1190 Virtex II FPGA configuration. The default is 5 mS. 1191 1192 CFG_FPGA_WAIT_CONFIG 1193 1194 Time to wait after FPGA configuration. The default is 1195 200 mS. 1196 1197- Configuration Management: 1198 CONFIG_IDENT_STRING 1199 1200 If defined, this string will be added to the U-Boot 1201 version information (U_BOOT_VERSION) 1202 1203- Vendor Parameter Protection: 1204 1205 U-Boot considers the values of the environment 1206 variables "serial#" (Board Serial Number) and 1207 "ethaddr" (Ethernet Address) to be parameters that 1208 are set once by the board vendor / manufacturer, and 1209 protects these variables from casual modification by 1210 the user. Once set, these variables are read-only, 1211 and write or delete attempts are rejected. You can 1212 change this behviour: 1213 1214 If CONFIG_ENV_OVERWRITE is #defined in your config 1215 file, the write protection for vendor parameters is 1216 completely disabled. Anybody can change or delete 1217 these parameters. 1218 1219 Alternatively, if you #define _both_ CONFIG_ETHADDR 1220 _and_ CONFIG_OVERWRITE_ETHADDR_ONCE, a default 1221 ethernet address is installed in the environment, 1222 which can be changed exactly ONCE by the user. [The 1223 serial# is unaffected by this, i. e. it remains 1224 read-only.] 1225 1226- Protected RAM: 1227 CONFIG_PRAM 1228 1229 Define this variable to enable the reservation of 1230 "protected RAM", i. e. RAM which is not overwritten 1231 by U-Boot. Define CONFIG_PRAM to hold the number of 1232 kB you want to reserve for pRAM. You can overwrite 1233 this default value by defining an environment 1234 variable "pram" to the number of kB you want to 1235 reserve. Note that the board info structure will 1236 still show the full amount of RAM. If pRAM is 1237 reserved, a new environment variable "mem" will 1238 automatically be defined to hold the amount of 1239 remaining RAM in a form that can be passed as boot 1240 argument to Linux, for instance like that: 1241 1242 setenv bootargs ... mem=\$(mem) 1243 saveenv 1244 1245 This way you can tell Linux not to use this memory, 1246 either, which results in a memory region that will 1247 not be affected by reboots. 1248 1249 *WARNING* If your board configuration uses automatic 1250 detection of the RAM size, you must make sure that 1251 this memory test is non-destructive. So far, the 1252 following board configurations are known to be 1253 "pRAM-clean": 1254 1255 ETX094, IVMS8, IVML24, SPD8xx, TQM8xxL, 1256 HERMES, IP860, RPXlite, LWMON, LANTEC, 1257 PCU_E, FLAGADM, TQM8260 1258 1259- Error Recovery: 1260 CONFIG_PANIC_HANG 1261 1262 Define this variable to stop the system in case of a 1263 fatal error, so that you have to reset it manually. 1264 This is probably NOT a good idea for an embedded 1265 system where you want to system to reboot 1266 automatically as fast as possible, but it may be 1267 useful during development since you can try to debug 1268 the conditions that lead to the situation. 1269 1270 CONFIG_NET_RETRY_COUNT 1271 1272 This variable defines the number of retries for 1273 network operations like ARP, RARP, TFTP, or BOOTP 1274 before giving up the operation. If not defined, a 1275 default value of 5 is used. 1276 1277- Command Interpreter: 1278 CFG_AUTO_COMPLETE 1279 1280 Enable auto completion of commands using TAB. 1281 1282 CFG_HUSH_PARSER 1283 1284 Define this variable to enable the "hush" shell (from 1285 Busybox) as command line interpreter, thus enabling 1286 powerful command line syntax like 1287 if...then...else...fi conditionals or `&&' and '||' 1288 constructs ("shell scripts"). 1289 1290 If undefined, you get the old, much simpler behaviour 1291 with a somewhat smaller memory footprint. 1292 1293 1294 CFG_PROMPT_HUSH_PS2 1295 1296 This defines the secondary prompt string, which is 1297 printed when the command interpreter needs more input 1298 to complete a command. Usually "> ". 1299 1300 Note: 1301 1302 In the current implementation, the local variables 1303 space and global environment variables space are 1304 separated. Local variables are those you define by 1305 simply typing `name=value'. To access a local 1306 variable later on, you have write `$name' or 1307 `${name}'; to execute the contents of a variable 1308 directly type `$name' at the command prompt. 1309 1310 Global environment variables are those you use 1311 setenv/printenv to work with. To run a command stored 1312 in such a variable, you need to use the run command, 1313 and you must not use the '$' sign to access them. 1314 1315 To store commands and special characters in a 1316 variable, please use double quotation marks 1317 surrounding the whole text of the variable, instead 1318 of the backslashes before semicolons and special 1319 symbols. 1320 1321- Default Environment: 1322 CONFIG_EXTRA_ENV_SETTINGS 1323 1324 Define this to contain any number of null terminated 1325 strings (variable = value pairs) that will be part of 1326 the default environment compiled into the boot image. 1327 1328 For example, place something like this in your 1329 board's config file: 1330 1331 #define CONFIG_EXTRA_ENV_SETTINGS \ 1332 "myvar1=value1\0" \ 1333 "myvar2=value2\0" 1334 1335 Warning: This method is based on knowledge about the 1336 internal format how the environment is stored by the 1337 U-Boot code. This is NOT an official, exported 1338 interface! Although it is unlikely that this format 1339 will change soon, there is no guarantee either. 1340 You better know what you are doing here. 1341 1342 Note: overly (ab)use of the default environment is 1343 discouraged. Make sure to check other ways to preset 1344 the environment like the autoscript function or the 1345 boot command first. 1346 1347- DataFlash Support: 1348 CONFIG_HAS_DATAFLASH 1349 1350 Defining this option enables DataFlash features and 1351 allows to read/write in Dataflash via the standard 1352 commands cp, md... 1353 1354- SystemACE Support: 1355 CONFIG_SYSTEMACE 1356 1357 Adding this option adds support for Xilinx SystemACE 1358 chips attached via some sort of local bus. The address 1359 of the chip must alsh be defined in the 1360 CFG_SYSTEMACE_BASE macro. For example: 1361 1362 #define CONFIG_SYSTEMACE 1363 #define CFG_SYSTEMACE_BASE 0xf0000000 1364 1365 When SystemACE support is added, the "ace" device type 1366 becomes available to the fat commands, i.e. fatls. 1367 1368- Show boot progress: 1369 CONFIG_SHOW_BOOT_PROGRESS 1370 1371 Defining this option allows to add some board- 1372 specific code (calling a user-provided function 1373 "show_boot_progress(int)") that enables you to show 1374 the system's boot progress on some display (for 1375 example, some LED's) on your board. At the moment, 1376 the following checkpoints are implemented: 1377 1378 Arg Where When 1379 1 common/cmd_bootm.c before attempting to boot an image 1380 -1 common/cmd_bootm.c Image header has bad magic number 1381 2 common/cmd_bootm.c Image header has correct magic number 1382 -2 common/cmd_bootm.c Image header has bad checksum 1383 3 common/cmd_bootm.c Image header has correct checksum 1384 -3 common/cmd_bootm.c Image data has bad checksum 1385 4 common/cmd_bootm.c Image data has correct checksum 1386 -4 common/cmd_bootm.c Image is for unsupported architecture 1387 5 common/cmd_bootm.c Architecture check OK 1388 -5 common/cmd_bootm.c Wrong Image Type (not kernel, multi, standalone) 1389 6 common/cmd_bootm.c Image Type check OK 1390 -6 common/cmd_bootm.c gunzip uncompression error 1391 -7 common/cmd_bootm.c Unimplemented compression type 1392 7 common/cmd_bootm.c Uncompression OK 1393 -8 common/cmd_bootm.c Wrong Image Type (not kernel, multi, standalone) 1394 8 common/cmd_bootm.c Image Type check OK 1395 -9 common/cmd_bootm.c Unsupported OS (not Linux, BSD, VxWorks, QNX) 1396 9 common/cmd_bootm.c Start initial ramdisk verification 1397 -10 common/cmd_bootm.c Ramdisk header has bad magic number 1398 -11 common/cmd_bootm.c Ramdisk header has bad checksum 1399 10 common/cmd_bootm.c Ramdisk header is OK 1400 -12 common/cmd_bootm.c Ramdisk data has bad checksum 1401 11 common/cmd_bootm.c Ramdisk data has correct checksum 1402 12 common/cmd_bootm.c Ramdisk verification complete, start loading 1403 -13 common/cmd_bootm.c Wrong Image Type (not PPC Linux Ramdisk) 1404 13 common/cmd_bootm.c Start multifile image verification 1405 14 common/cmd_bootm.c No initial ramdisk, no multifile, continue. 1406 15 common/cmd_bootm.c All preparation done, transferring control to OS 1407 1408 -30 lib_ppc/board.c Fatal error, hang the system 1409 -31 post/post.c POST test failed, detected by post_output_backlog() 1410 -32 post/post.c POST test failed, detected by post_run_single() 1411 1412 -1 common/cmd_doc.c Bad usage of "doc" command 1413 -1 common/cmd_doc.c No boot device 1414 -1 common/cmd_doc.c Unknown Chip ID on boot device 1415 -1 common/cmd_doc.c Read Error on boot device 1416 -1 common/cmd_doc.c Image header has bad magic number 1417 1418 -1 common/cmd_ide.c Bad usage of "ide" command 1419 -1 common/cmd_ide.c No boot device 1420 -1 common/cmd_ide.c Unknown boot device 1421 -1 common/cmd_ide.c Unknown partition table 1422 -1 common/cmd_ide.c Invalid partition type 1423 -1 common/cmd_ide.c Read Error on boot device 1424 -1 common/cmd_ide.c Image header has bad magic number 1425 1426 -1 common/cmd_nand.c Bad usage of "nand" command 1427 -1 common/cmd_nand.c No boot device 1428 -1 common/cmd_nand.c Unknown Chip ID on boot device 1429 -1 common/cmd_nand.c Read Error on boot device 1430 -1 common/cmd_nand.c Image header has bad magic number 1431 1432 -1 common/env_common.c Environment has a bad CRC, using default 1433 1434 1435Modem Support: 1436-------------- 1437 1438[so far only for SMDK2400 and TRAB boards] 1439 1440- Modem support endable: 1441 CONFIG_MODEM_SUPPORT 1442 1443- RTS/CTS Flow control enable: 1444 CONFIG_HWFLOW 1445 1446- Modem debug support: 1447 CONFIG_MODEM_SUPPORT_DEBUG 1448 1449 Enables debugging stuff (char screen[1024], dbg()) 1450 for modem support. Useful only with BDI2000. 1451 1452- Interrupt support (PPC): 1453 1454 There are common interrupt_init() and timer_interrupt() 1455 for all PPC archs. interrupt_init() calls interrupt_init_cpu() 1456 for cpu specific initialization. interrupt_init_cpu() 1457 should set decrementer_count to appropriate value. If 1458 cpu resets decrementer automatically after interrupt 1459 (ppc4xx) it should set decrementer_count to zero. 1460 timer_interrupt() calls timer_interrupt_cpu() for cpu 1461 specific handling. If board has watchdog / status_led 1462 / other_activity_monitor it works automatically from 1463 general timer_interrupt(). 1464 1465- General: 1466 1467 In the target system modem support is enabled when a 1468 specific key (key combination) is pressed during 1469 power-on. Otherwise U-Boot will boot normally 1470 (autoboot). The key_pressed() fuction is called from 1471 board_init(). Currently key_pressed() is a dummy 1472 function, returning 1 and thus enabling modem 1473 initialization. 1474 1475 If there are no modem init strings in the 1476 environment, U-Boot proceed to autoboot; the 1477 previous output (banner, info printfs) will be 1478 supressed, though. 1479 1480 See also: doc/README.Modem 1481 1482 1483Configuration Settings: 1484----------------------- 1485 1486- CFG_LONGHELP: Defined when you want long help messages included; 1487 undefine this when you're short of memory. 1488 1489- CFG_PROMPT: This is what U-Boot prints on the console to 1490 prompt for user input. 1491 1492- CFG_CBSIZE: Buffer size for input from the Console 1493 1494- CFG_PBSIZE: Buffer size for Console output 1495 1496- CFG_MAXARGS: max. Number of arguments accepted for monitor commands 1497 1498- CFG_BARGSIZE: Buffer size for Boot Arguments which are passed to 1499 the application (usually a Linux kernel) when it is 1500 booted 1501 1502- CFG_BAUDRATE_TABLE: 1503 List of legal baudrate settings for this board. 1504 1505- CFG_CONSOLE_INFO_QUIET 1506 Suppress display of console information at boot. 1507 1508- CFG_CONSOLE_IS_IN_ENV 1509 If the board specific function 1510 extern int overwrite_console (void); 1511 returns 1, the stdin, stderr and stdout are switched to the 1512 serial port, else the settings in the environment are used. 1513 1514- CFG_CONSOLE_OVERWRITE_ROUTINE 1515 Enable the call to overwrite_console(). 1516 1517- CFG_CONSOLE_ENV_OVERWRITE 1518 Enable overwrite of previous console environment settings. 1519 1520- CFG_MEMTEST_START, CFG_MEMTEST_END: 1521 Begin and End addresses of the area used by the 1522 simple memory test. 1523 1524- CFG_ALT_MEMTEST: 1525 Enable an alternate, more extensive memory test. 1526 1527- CFG_MEMTEST_SCRATCH: 1528 Scratch address used by the alternate memory test 1529 You only need to set this if address zero isn't writeable 1530 1531- CFG_TFTP_LOADADDR: 1532 Default load address for network file downloads 1533 1534- CFG_LOADS_BAUD_CHANGE: 1535 Enable temporary baudrate change while serial download 1536 1537- CFG_SDRAM_BASE: 1538 Physical start address of SDRAM. _Must_ be 0 here. 1539 1540- CFG_MBIO_BASE: 1541 Physical start address of Motherboard I/O (if using a 1542 Cogent motherboard) 1543 1544- CFG_FLASH_BASE: 1545 Physical start address of Flash memory. 1546 1547- CFG_MONITOR_BASE: 1548 Physical start address of boot monitor code (set by 1549 make config files to be same as the text base address 1550 (TEXT_BASE) used when linking) - same as 1551 CFG_FLASH_BASE when booting from flash. 1552 1553- CFG_MONITOR_LEN: 1554 Size of memory reserved for monitor code, used to 1555 determine _at_compile_time_ (!) if the environment is 1556 embedded within the U-Boot image, or in a separate 1557 flash sector. 1558 1559- CFG_MALLOC_LEN: 1560 Size of DRAM reserved for malloc() use. 1561 1562- CFG_BOOTMAPSZ: 1563 Maximum size of memory mapped by the startup code of 1564 the Linux kernel; all data that must be processed by 1565 the Linux kernel (bd_info, boot arguments, eventually 1566 initrd image) must be put below this limit. 1567 1568- CFG_MAX_FLASH_BANKS: 1569 Max number of Flash memory banks 1570 1571- CFG_MAX_FLASH_SECT: 1572 Max number of sectors on a Flash chip 1573 1574- CFG_FLASH_ERASE_TOUT: 1575 Timeout for Flash erase operations (in ms) 1576 1577- CFG_FLASH_WRITE_TOUT: 1578 Timeout for Flash write operations (in ms) 1579 1580- CFG_FLASH_LOCK_TOUT 1581 Timeout for Flash set sector lock bit operation (in ms) 1582 1583- CFG_FLASH_UNLOCK_TOUT 1584 Timeout for Flash clear lock bits operation (in ms) 1585 1586- CFG_FLASH_PROTECTION 1587 If defined, hardware flash sectors protection is used 1588 instead of U-Boot software protection. 1589 1590- CFG_DIRECT_FLASH_TFTP: 1591 1592 Enable TFTP transfers directly to flash memory; 1593 without this option such a download has to be 1594 performed in two steps: (1) download to RAM, and (2) 1595 copy from RAM to flash. 1596 1597 The two-step approach is usually more reliable, since 1598 you can check if the download worked before you erase 1599 the flash, but in some situations (when sytem RAM is 1600 too limited to allow for a tempory copy of the 1601 downloaded image) this option may be very useful. 1602 1603- CFG_FLASH_CFI: 1604 Define if the flash driver uses extra elements in the 1605 common flash structure for storing flash geometry. 1606 1607- CFG_FLASH_CFI_DRIVER 1608 This option also enables the building of the cfi_flash driver 1609 in the drivers directory 1610 1611- CFG_RX_ETH_BUFFER: 1612 Defines the number of ethernet receive buffers. On some 1613 ethernet controllers it is recommended to set this value 1614 to 8 or even higher (EEPRO100 or 405 EMAC), since all 1615 buffers can be full shortly after enabling the interface 1616 on high ethernet traffic. 1617 Defaults to 4 if not defined. 1618 1619The following definitions that deal with the placement and management 1620of environment data (variable area); in general, we support the 1621following configurations: 1622 1623- CFG_ENV_IS_IN_FLASH: 1624 1625 Define this if the environment is in flash memory. 1626 1627 a) The environment occupies one whole flash sector, which is 1628 "embedded" in the text segment with the U-Boot code. This 1629 happens usually with "bottom boot sector" or "top boot 1630 sector" type flash chips, which have several smaller 1631 sectors at the start or the end. For instance, such a 1632 layout can have sector sizes of 8, 2x4, 16, Nx32 kB. In 1633 such a case you would place the environment in one of the 1634 4 kB sectors - with U-Boot code before and after it. With 1635 "top boot sector" type flash chips, you would put the 1636 environment in one of the last sectors, leaving a gap 1637 between U-Boot and the environment. 1638 1639 - CFG_ENV_OFFSET: 1640 1641 Offset of environment data (variable area) to the 1642 beginning of flash memory; for instance, with bottom boot 1643 type flash chips the second sector can be used: the offset 1644 for this sector is given here. 1645 1646 CFG_ENV_OFFSET is used relative to CFG_FLASH_BASE. 1647 1648 - CFG_ENV_ADDR: 1649 1650 This is just another way to specify the start address of 1651 the flash sector containing the environment (instead of 1652 CFG_ENV_OFFSET). 1653 1654 - CFG_ENV_SECT_SIZE: 1655 1656 Size of the sector containing the environment. 1657 1658 1659 b) Sometimes flash chips have few, equal sized, BIG sectors. 1660 In such a case you don't want to spend a whole sector for 1661 the environment. 1662 1663 - CFG_ENV_SIZE: 1664 1665 If you use this in combination with CFG_ENV_IS_IN_FLASH 1666 and CFG_ENV_SECT_SIZE, you can specify to use only a part 1667 of this flash sector for the environment. This saves 1668 memory for the RAM copy of the environment. 1669 1670 It may also save flash memory if you decide to use this 1671 when your environment is "embedded" within U-Boot code, 1672 since then the remainder of the flash sector could be used 1673 for U-Boot code. It should be pointed out that this is 1674 STRONGLY DISCOURAGED from a robustness point of view: 1675 updating the environment in flash makes it always 1676 necessary to erase the WHOLE sector. If something goes 1677 wrong before the contents has been restored from a copy in 1678 RAM, your target system will be dead. 1679 1680 - CFG_ENV_ADDR_REDUND 1681 CFG_ENV_SIZE_REDUND 1682 1683 These settings describe a second storage area used to hold 1684 a redundand copy of the environment data, so that there is 1685 a valid backup copy in case there is a power failure during 1686 a "saveenv" operation. 1687 1688BE CAREFUL! Any changes to the flash layout, and some changes to the 1689source code will make it necessary to adapt <board>/u-boot.lds* 1690accordingly! 1691 1692 1693- CFG_ENV_IS_IN_NVRAM: 1694 1695 Define this if you have some non-volatile memory device 1696 (NVRAM, battery buffered SRAM) which you want to use for the 1697 environment. 1698 1699 - CFG_ENV_ADDR: 1700 - CFG_ENV_SIZE: 1701 1702 These two #defines are used to determin the memory area you 1703 want to use for environment. It is assumed that this memory 1704 can just be read and written to, without any special 1705 provision. 1706 1707BE CAREFUL! The first access to the environment happens quite early 1708in U-Boot initalization (when we try to get the setting of for the 1709console baudrate). You *MUST* have mappend your NVRAM area then, or 1710U-Boot will hang. 1711 1712Please note that even with NVRAM we still use a copy of the 1713environment in RAM: we could work on NVRAM directly, but we want to 1714keep settings there always unmodified except somebody uses "saveenv" 1715to save the current settings. 1716 1717 1718- CFG_ENV_IS_IN_EEPROM: 1719 1720 Use this if you have an EEPROM or similar serial access 1721 device and a driver for it. 1722 1723 - CFG_ENV_OFFSET: 1724 - CFG_ENV_SIZE: 1725 1726 These two #defines specify the offset and size of the 1727 environment area within the total memory of your EEPROM. 1728 1729 - CFG_I2C_EEPROM_ADDR: 1730 If defined, specified the chip address of the EEPROM device. 1731 The default address is zero. 1732 1733 - CFG_EEPROM_PAGE_WRITE_BITS: 1734 If defined, the number of bits used to address bytes in a 1735 single page in the EEPROM device. A 64 byte page, for example 1736 would require six bits. 1737 1738 - CFG_EEPROM_PAGE_WRITE_DELAY_MS: 1739 If defined, the number of milliseconds to delay between 1740 page writes. The default is zero milliseconds. 1741 1742 - CFG_I2C_EEPROM_ADDR_LEN: 1743 The length in bytes of the EEPROM memory array address. Note 1744 that this is NOT the chip address length! 1745 1746 - CFG_EEPROM_SIZE: 1747 The size in bytes of the EEPROM device. 1748 1749 1750- CFG_ENV_IS_IN_DATAFLASH: 1751 1752 Define this if you have a DataFlash memory device which you 1753 want to use for the environment. 1754 1755 - CFG_ENV_OFFSET: 1756 - CFG_ENV_ADDR: 1757 - CFG_ENV_SIZE: 1758 1759 These three #defines specify the offset and size of the 1760 environment area within the total memory of your DataFlash placed 1761 at the specified address. 1762 1763 1764- CFG_SPI_INIT_OFFSET 1765 1766 Defines offset to the initial SPI buffer area in DPRAM. The 1767 area is used at an early stage (ROM part) if the environment 1768 is configured to reside in the SPI EEPROM: We need a 520 byte 1769 scratch DPRAM area. It is used between the two initialization 1770 calls (spi_init_f() and spi_init_r()). A value of 0xB00 seems 1771 to be a good choice since it makes it far enough from the 1772 start of the data area as well as from the stack pointer. 1773 1774Please note that the environment is read-only as long as the monitor 1775has been relocated to RAM and a RAM copy of the environment has been 1776created; also, when using EEPROM you will have to use getenv_r() 1777until then to read environment variables. 1778 1779The environment is protected by a CRC32 checksum. Before the monitor 1780is relocated into RAM, as a result of a bad CRC you will be working 1781with the compiled-in default environment - *silently*!!! [This is 1782necessary, because the first environment variable we need is the 1783"baudrate" setting for the console - if we have a bad CRC, we don't 1784have any device yet where we could complain.] 1785 1786Note: once the monitor has been relocated, then it will complain if 1787the default environment is used; a new CRC is computed as soon as you 1788use the "saveenv" command to store a valid environment. 1789 1790- CFG_FAULT_ECHO_LINK_DOWN: 1791 Echo the inverted Ethernet link state to the fault LED. 1792 1793 Note: If this option is active, then CFG_FAULT_MII_ADDR 1794 also needs to be defined. 1795 1796- CFG_FAULT_MII_ADDR: 1797 MII address of the PHY to check for the Ethernet link state. 1798 1799- CFG_64BIT_VSPRINTF: 1800 Makes vsprintf (and all *printf functions) support printing 1801 of 64bit values by using the L quantifier 1802 1803- CFG_64BIT_STRTOUL: 1804 Adds simple_strtoull that returns a 64bit value 1805 1806Low Level (hardware related) configuration options: 1807--------------------------------------------------- 1808 1809- CFG_CACHELINE_SIZE: 1810 Cache Line Size of the CPU. 1811 1812- CFG_DEFAULT_IMMR: 1813 Default address of the IMMR after system reset. 1814 1815 Needed on some 8260 systems (MPC8260ADS, PQ2FADS-ZU, 1816 and RPXsuper) to be able to adjust the position of 1817 the IMMR register after a reset. 1818 1819- Floppy Disk Support: 1820 CFG_FDC_DRIVE_NUMBER 1821 1822 the default drive number (default value 0) 1823 1824 CFG_ISA_IO_STRIDE 1825 1826 defines the spacing between fdc chipset registers 1827 (default value 1) 1828 1829 CFG_ISA_IO_OFFSET 1830 1831 defines the offset of register from address. It 1832 depends on which part of the data bus is connected to 1833 the fdc chipset. (default value 0) 1834 1835 If CFG_ISA_IO_STRIDE CFG_ISA_IO_OFFSET and 1836 CFG_FDC_DRIVE_NUMBER are undefined, they take their 1837 default value. 1838 1839 if CFG_FDC_HW_INIT is defined, then the function 1840 fdc_hw_init() is called at the beginning of the FDC 1841 setup. fdc_hw_init() must be provided by the board 1842 source code. It is used to make hardware dependant 1843 initializations. 1844 1845- CFG_IMMR: Physical address of the Internal Memory Mapped 1846 Register; DO NOT CHANGE! (11-4) 1847 [MPC8xx systems only] 1848 1849- CFG_INIT_RAM_ADDR: 1850 1851 Start address of memory area that can be used for 1852 initial data and stack; please note that this must be 1853 writable memory that is working WITHOUT special 1854 initialization, i. e. you CANNOT use normal RAM which 1855 will become available only after programming the 1856 memory controller and running certain initialization 1857 sequences. 1858 1859 U-Boot uses the following memory types: 1860 - MPC8xx and MPC8260: IMMR (internal memory of the CPU) 1861 - MPC824X: data cache 1862 - PPC4xx: data cache 1863 1864- CFG_GBL_DATA_OFFSET: 1865 1866 Offset of the initial data structure in the memory 1867 area defined by CFG_INIT_RAM_ADDR. Usually 1868 CFG_GBL_DATA_OFFSET is chosen such that the initial 1869 data is located at the end of the available space 1870 (sometimes written as (CFG_INIT_RAM_END - 1871 CFG_INIT_DATA_SIZE), and the initial stack is just 1872 below that area (growing from (CFG_INIT_RAM_ADDR + 1873 CFG_GBL_DATA_OFFSET) downward. 1874 1875 Note: 1876 On the MPC824X (or other systems that use the data 1877 cache for initial memory) the address chosen for 1878 CFG_INIT_RAM_ADDR is basically arbitrary - it must 1879 point to an otherwise UNUSED address space between 1880 the top of RAM and the start of the PCI space. 1881 1882- CFG_SIUMCR: SIU Module Configuration (11-6) 1883 1884- CFG_SYPCR: System Protection Control (11-9) 1885 1886- CFG_TBSCR: Time Base Status and Control (11-26) 1887 1888- CFG_PISCR: Periodic Interrupt Status and Control (11-31) 1889 1890- CFG_PLPRCR: PLL, Low-Power, and Reset Control Register (15-30) 1891 1892- CFG_SCCR: System Clock and reset Control Register (15-27) 1893 1894- CFG_OR_TIMING_SDRAM: 1895 SDRAM timing 1896 1897- CFG_MAMR_PTA: 1898 periodic timer for refresh 1899 1900- CFG_DER: Debug Event Register (37-47) 1901 1902- FLASH_BASE0_PRELIM, FLASH_BASE1_PRELIM, CFG_REMAP_OR_AM, 1903 CFG_PRELIM_OR_AM, CFG_OR_TIMING_FLASH, CFG_OR0_REMAP, 1904 CFG_OR0_PRELIM, CFG_BR0_PRELIM, CFG_OR1_REMAP, CFG_OR1_PRELIM, 1905 CFG_BR1_PRELIM: 1906 Memory Controller Definitions: BR0/1 and OR0/1 (FLASH) 1907 1908- SDRAM_BASE2_PRELIM, SDRAM_BASE3_PRELIM, SDRAM_MAX_SIZE, 1909 CFG_OR_TIMING_SDRAM, CFG_OR2_PRELIM, CFG_BR2_PRELIM, 1910 CFG_OR3_PRELIM, CFG_BR3_PRELIM: 1911 Memory Controller Definitions: BR2/3 and OR2/3 (SDRAM) 1912 1913- CFG_MAMR_PTA, CFG_MPTPR_2BK_4K, CFG_MPTPR_1BK_4K, CFG_MPTPR_2BK_8K, 1914 CFG_MPTPR_1BK_8K, CFG_MAMR_8COL, CFG_MAMR_9COL: 1915 Machine Mode Register and Memory Periodic Timer 1916 Prescaler definitions (SDRAM timing) 1917 1918- CFG_I2C_UCODE_PATCH, CFG_I2C_DPMEM_OFFSET [0x1FC0]: 1919 enable I2C microcode relocation patch (MPC8xx); 1920 define relocation offset in DPRAM [DSP2] 1921 1922- CFG_SPI_UCODE_PATCH, CFG_SPI_DPMEM_OFFSET [0x1FC0]: 1923 enable SPI microcode relocation patch (MPC8xx); 1924 define relocation offset in DPRAM [SCC4] 1925 1926- CFG_USE_OSCCLK: 1927 Use OSCM clock mode on MBX8xx board. Be careful, 1928 wrong setting might damage your board. Read 1929 doc/README.MBX before setting this variable! 1930 1931- CFG_CPM_POST_WORD_ADDR: (MPC8xx, MPC8260 only) 1932 Offset of the bootmode word in DPRAM used by post 1933 (Power On Self Tests). This definition overrides 1934 #define'd default value in commproc.h resp. 1935 cpm_8260.h. 1936 1937- CFG_PCI_SLV_MEM_LOCAL, CFG_PCI_SLV_MEM_BUS, CFG_PICMR0_MASK_ATTRIB, 1938 CFG_PCI_MSTR0_LOCAL, CFG_PCIMSK0_MASK, CFG_PCI_MSTR1_LOCAL, 1939 CFG_PCIMSK1_MASK, CFG_PCI_MSTR_MEM_LOCAL, CFG_PCI_MSTR_MEM_BUS, 1940 CFG_CPU_PCI_MEM_START, CFG_PCI_MSTR_MEM_SIZE, CFG_POCMR0_MASK_ATTRIB, 1941 CFG_PCI_MSTR_MEMIO_LOCAL, CFG_PCI_MSTR_MEMIO_BUS, CPU_PCI_MEMIO_START, 1942 CFG_PCI_MSTR_MEMIO_SIZE, CFG_POCMR1_MASK_ATTRIB, CFG_PCI_MSTR_IO_LOCAL, 1943 CFG_PCI_MSTR_IO_BUS, CFG_CPU_PCI_IO_START, CFG_PCI_MSTR_IO_SIZE, 1944 CFG_POCMR2_MASK_ATTRIB: (MPC826x only) 1945 Overrides the default PCI memory map in cpu/mpc8260/pci.c if set. 1946 1947Building the Software: 1948====================== 1949 1950Building U-Boot has been tested in native PPC environments (on a 1951PowerBook G3 running LinuxPPC 2000) and in cross environments 1952(running RedHat 6.x and 7.x Linux on x86, Solaris 2.6 on a SPARC, and 1953NetBSD 1.5 on x86). 1954 1955If you are not using a native PPC environment, it is assumed that you 1956have the GNU cross compiling tools available in your path and named 1957with a prefix of "powerpc-linux-". If this is not the case, (e.g. if 1958you are using Monta Vista's Hard Hat Linux CDK 1.2) you must change 1959the definition of CROSS_COMPILE in Makefile. For HHL on a 4xx CPU, 1960change it to: 1961 1962 CROSS_COMPILE = ppc_4xx- 1963 1964 1965U-Boot is intended to be simple to build. After installing the 1966sources you must configure U-Boot for one specific board type. This 1967is done by typing: 1968 1969 make NAME_config 1970 1971where "NAME_config" is the name of one of the existing 1972configurations; the following names are supported: 1973 1974 ADCIOP_config GTH_config TQM850L_config 1975 ADS860_config IP860_config TQM855L_config 1976 AR405_config IVML24_config TQM860L_config 1977 CANBT_config IVMS8_config WALNUT405_config 1978 CPCI405_config LANTEC_config cogent_common_config 1979 CPCIISER4_config MBX_config cogent_mpc8260_config 1980 CU824_config MBX860T_config cogent_mpc8xx_config 1981 ESTEEM192E_config RPXlite_config hermes_config 1982 ETX094_config RPXsuper_config hymod_config 1983 FADS823_config SM850_config lwmon_config 1984 FADS850SAR_config SPD823TS_config pcu_e_config 1985 FADS860T_config SXNI855T_config rsdproto_config 1986 FPS850L_config Sandpoint8240_config sbc8260_config 1987 GENIETV_config TQM823L_config PIP405_config 1988 GEN860T_config EBONY_config FPS860L_config 1989 ELPT860_config cmi_mpc5xx_config NETVIA_config 1990 at91rm9200dk_config omap1510inn_config MPC8260ADS_config 1991 omap1610inn_config ZPC1900_config MPC8540ADS_config 1992 MPC8560ADS_config QS850_config QS823_config 1993 QS860T_config DUET_ADS_config omap1610h2_config 1994 1995Note: for some board special configuration names may exist; check if 1996 additional information is available from the board vendor; for 1997 instance, the TQM8xxL systems run normally at 50 MHz and use a 1998 SCC for 10baseT ethernet; there are also systems with 80 MHz 1999 CPU clock, and an optional Fast Ethernet module is available 2000 for CPU's with FEC. You can select such additional "features" 2001 when chosing the configuration, i. e. 2002 2003 make TQM860L_config 2004 - will configure for a plain TQM860L, i. e. 50MHz, no FEC 2005 2006 make TQM860L_FEC_config 2007 - will configure for a TQM860L at 50MHz with FEC for ethernet 2008 2009 make TQM860L_80MHz_config 2010 - will configure for a TQM860L at 80 MHz, with normal 10baseT 2011 interface 2012 2013 make TQM860L_FEC_80MHz_config 2014 - will configure for a TQM860L at 80 MHz with FEC for ethernet 2015 2016 make TQM823L_LCD_config 2017 - will configure for a TQM823L with U-Boot console on LCD 2018 2019 make TQM823L_LCD_80MHz_config 2020 - will configure for a TQM823L at 80 MHz with U-Boot console on LCD 2021 2022 etc. 2023 2024 2025Finally, type "make all", and you should get some working U-Boot 2026images ready for download to / installation on your system: 2027 2028- "u-boot.bin" is a raw binary image 2029- "u-boot" is an image in ELF binary format 2030- "u-boot.srec" is in Motorola S-Record format 2031 2032 2033Please be aware that the Makefiles assume you are using GNU make, so 2034for instance on NetBSD you might need to use "gmake" instead of 2035native "make". 2036 2037 2038If the system board that you have is not listed, then you will need 2039to port U-Boot to your hardware platform. To do this, follow these 2040steps: 2041 20421. Add a new configuration option for your board to the toplevel 2043 "Makefile" and to the "MAKEALL" script, using the existing 2044 entries as examples. Note that here and at many other places 2045 boards and other names are listed in alphabetical sort order. Please 2046 keep this order. 20472. Create a new directory to hold your board specific code. Add any 2048 files you need. In your board directory, you will need at least 2049 the "Makefile", a "<board>.c", "flash.c" and "u-boot.lds". 20503. Create a new configuration file "include/configs/<board>.h" for 2051 your board 20523. If you're porting U-Boot to a new CPU, then also create a new 2053 directory to hold your CPU specific code. Add any files you need. 20544. Run "make <board>_config" with your new name. 20555. Type "make", and you should get a working "u-boot.srec" file 2056 to be installed on your target system. 20576. Debug and solve any problems that might arise. 2058 [Of course, this last step is much harder than it sounds.] 2059 2060 2061Testing of U-Boot Modifications, Ports to New Hardware, etc.: 2062============================================================== 2063 2064If you have modified U-Boot sources (for instance added a new board 2065or support for new devices, a new CPU, etc.) you are expected to 2066provide feedback to the other developers. The feedback normally takes 2067the form of a "patch", i. e. a context diff against a certain (latest 2068official or latest in CVS) version of U-Boot sources. 2069 2070But before you submit such a patch, please verify that your modifi- 2071cation did not break existing code. At least make sure that *ALL* of 2072the supported boards compile WITHOUT ANY compiler warnings. To do so, 2073just run the "MAKEALL" script, which will configure and build U-Boot 2074for ALL supported system. Be warned, this will take a while. You can 2075select which (cross) compiler to use by passing a `CROSS_COMPILE' 2076environment variable to the script, i. e. to use the cross tools from 2077MontaVista's Hard Hat Linux you can type 2078 2079 CROSS_COMPILE=ppc_8xx- MAKEALL 2080 2081or to build on a native PowerPC system you can type 2082 2083 CROSS_COMPILE=' ' MAKEALL 2084 2085See also "U-Boot Porting Guide" below. 2086 2087 2088Monitor Commands - Overview: 2089============================ 2090 2091go - start application at address 'addr' 2092run - run commands in an environment variable 2093bootm - boot application image from memory 2094bootp - boot image via network using BootP/TFTP protocol 2095tftpboot- boot image via network using TFTP protocol 2096 and env variables "ipaddr" and "serverip" 2097 (and eventually "gatewayip") 2098rarpboot- boot image via network using RARP/TFTP protocol 2099diskboot- boot from IDE devicebootd - boot default, i.e., run 'bootcmd' 2100loads - load S-Record file over serial line 2101loadb - load binary file over serial line (kermit mode) 2102md - memory display 2103mm - memory modify (auto-incrementing) 2104nm - memory modify (constant address) 2105mw - memory write (fill) 2106cp - memory copy 2107cmp - memory compare 2108crc32 - checksum calculation 2109imd - i2c memory display 2110imm - i2c memory modify (auto-incrementing) 2111inm - i2c memory modify (constant address) 2112imw - i2c memory write (fill) 2113icrc32 - i2c checksum calculation 2114iprobe - probe to discover valid I2C chip addresses 2115iloop - infinite loop on address range 2116isdram - print SDRAM configuration information 2117sspi - SPI utility commands 2118base - print or set address offset 2119printenv- print environment variables 2120setenv - set environment variables 2121saveenv - save environment variables to persistent storage 2122protect - enable or disable FLASH write protection 2123erase - erase FLASH memory 2124flinfo - print FLASH memory information 2125bdinfo - print Board Info structure 2126iminfo - print header information for application image 2127coninfo - print console devices and informations 2128ide - IDE sub-system 2129loop - infinite loop on address range 2130mtest - simple RAM test 2131icache - enable or disable instruction cache 2132dcache - enable or disable data cache 2133reset - Perform RESET of the CPU 2134echo - echo args to console 2135version - print monitor version 2136help - print online help 2137? - alias for 'help' 2138 2139 2140Monitor Commands - Detailed Description: 2141======================================== 2142 2143TODO. 2144 2145For now: just type "help <command>". 2146 2147 2148Environment Variables: 2149====================== 2150 2151U-Boot supports user configuration using Environment Variables which 2152can be made persistent by saving to Flash memory. 2153 2154Environment Variables are set using "setenv", printed using 2155"printenv", and saved to Flash using "saveenv". Using "setenv" 2156without a value can be used to delete a variable from the 2157environment. As long as you don't save the environment you are 2158working with an in-memory copy. In case the Flash area containing the 2159environment is erased by accident, a default environment is provided. 2160 2161Some configuration options can be set using Environment Variables: 2162 2163 baudrate - see CONFIG_BAUDRATE 2164 2165 bootdelay - see CONFIG_BOOTDELAY 2166 2167 bootcmd - see CONFIG_BOOTCOMMAND 2168 2169 bootargs - Boot arguments when booting an RTOS image 2170 2171 bootfile - Name of the image to load with TFTP 2172 2173 autoload - if set to "no" (any string beginning with 'n'), 2174 "bootp" will just load perform a lookup of the 2175 configuration from the BOOTP server, but not try to 2176 load any image using TFTP 2177 2178 autostart - if set to "yes", an image loaded using the "bootp", 2179 "rarpboot", "tftpboot" or "diskboot" commands will 2180 be automatically started (by internally calling 2181 "bootm") 2182 2183 If set to "no", a standalone image passed to the 2184 "bootm" command will be copied to the load address 2185 (and eventually uncompressed), but NOT be started. 2186 This can be used to load and uncompress arbitrary 2187 data. 2188 2189 initrd_high - restrict positioning of initrd images: 2190 If this variable is not set, initrd images will be 2191 copied to the highest possible address in RAM; this 2192 is usually what you want since it allows for 2193 maximum initrd size. If for some reason you want to 2194 make sure that the initrd image is loaded below the 2195 CFG_BOOTMAPSZ limit, you can set this environment 2196 variable to a value of "no" or "off" or "0". 2197 Alternatively, you can set it to a maximum upper 2198 address to use (U-Boot will still check that it 2199 does not overwrite the U-Boot stack and data). 2200 2201 For instance, when you have a system with 16 MB 2202 RAM, and want to reserve 4 MB from use by Linux, 2203 you can do this by adding "mem=12M" to the value of 2204 the "bootargs" variable. However, now you must make 2205 sure that the initrd image is placed in the first 2206 12 MB as well - this can be done with 2207 2208 setenv initrd_high 00c00000 2209 2210 If you set initrd_high to 0xFFFFFFFF, this is an 2211 indication to U-Boot that all addresses are legal 2212 for the Linux kernel, including addresses in flash 2213 memory. In this case U-Boot will NOT COPY the 2214 ramdisk at all. This may be useful to reduce the 2215 boot time on your system, but requires that this 2216 feature is supported by your Linux kernel. 2217 2218 ipaddr - IP address; needed for tftpboot command 2219 2220 loadaddr - Default load address for commands like "bootp", 2221 "rarpboot", "tftpboot", "loadb" or "diskboot" 2222 2223 loads_echo - see CONFIG_LOADS_ECHO 2224 2225 serverip - TFTP server IP address; needed for tftpboot command 2226 2227 bootretry - see CONFIG_BOOT_RETRY_TIME 2228 2229 bootdelaykey - see CONFIG_AUTOBOOT_DELAY_STR 2230 2231 bootstopkey - see CONFIG_AUTOBOOT_STOP_STR 2232 2233 ethprime - When CONFIG_NET_MULTI is enabled controls which 2234 interface is used first. 2235 2236 ethact - When CONFIG_NET_MULTI is enabled controls which 2237 interface is currently active. For example you 2238 can do the following 2239 2240 => setenv ethact FEC ETHERNET 2241 => ping 192.168.0.1 # traffic sent on FEC ETHERNET 2242 => setenv ethact SCC ETHERNET 2243 => ping 10.0.0.1 # traffic sent on SCC ETHERNET 2244 2245 netretry - When set to "no" each network operation will 2246 either succeed or fail without retrying. 2247 Useful on scripts which control the retry operation 2248 themselves. 2249 2250 vlan - When set to a value < 4095 the traffic over 2251 ethernet is encapsulated/received over 802.1q 2252 VLAN tagged frames. 2253 2254The following environment variables may be used and automatically 2255updated by the network boot commands ("bootp" and "rarpboot"), 2256depending the information provided by your boot server: 2257 2258 bootfile - see above 2259 dnsip - IP address of your Domain Name Server 2260 dnsip2 - IP address of your secondary Domain Name Server 2261 gatewayip - IP address of the Gateway (Router) to use 2262 hostname - Target hostname 2263 ipaddr - see above 2264 netmask - Subnet Mask 2265 rootpath - Pathname of the root filesystem on the NFS server 2266 serverip - see above 2267 2268 2269There are two special Environment Variables: 2270 2271 serial# - contains hardware identification information such 2272 as type string and/or serial number 2273 ethaddr - Ethernet address 2274 2275These variables can be set only once (usually during manufacturing of 2276the board). U-Boot refuses to delete or overwrite these variables 2277once they have been set once. 2278 2279 2280Further special Environment Variables: 2281 2282 ver - Contains the U-Boot version string as printed 2283 with the "version" command. This variable is 2284 readonly (see CONFIG_VERSION_VARIABLE). 2285 2286 2287Please note that changes to some configuration parameters may take 2288only effect after the next boot (yes, that's just like Windoze :-). 2289 2290 2291Command Line Parsing: 2292===================== 2293 2294There are two different command line parsers available with U-Boot: 2295the old "simple" one, and the much more powerful "hush" shell: 2296 2297Old, simple command line parser: 2298-------------------------------- 2299 2300- supports environment variables (through setenv / saveenv commands) 2301- several commands on one line, separated by ';' 2302- variable substitution using "... $(name) ..." syntax 2303- special characters ('$', ';') can be escaped by prefixing with '\', 2304 for example: 2305 setenv bootcmd bootm \$(address) 2306- You can also escape text by enclosing in single apostrophes, for example: 2307 setenv addip 'setenv bootargs $bootargs ip=$ipaddr:$serverip:$gatewayip:$netmask:$hostname::off' 2308 2309Hush shell: 2310----------- 2311 2312- similar to Bourne shell, with control structures like 2313 if...then...else...fi, for...do...done; while...do...done, 2314 until...do...done, ... 2315- supports environment ("global") variables (through setenv / saveenv 2316 commands) and local shell variables (through standard shell syntax 2317 "name=value"); only environment variables can be used with "run" 2318 command 2319 2320General rules: 2321-------------- 2322 2323(1) If a command line (or an environment variable executed by a "run" 2324 command) contains several commands separated by semicolon, and 2325 one of these commands fails, then the remaining commands will be 2326 executed anyway. 2327 2328(2) If you execute several variables with one call to run (i. e. 2329 calling run with a list af variables as arguments), any failing 2330 command will cause "run" to terminate, i. e. the remaining 2331 variables are not executed. 2332 2333Note for Redundant Ethernet Interfaces: 2334======================================= 2335 2336Some boards come with redundant ethernet interfaces; U-Boot supports 2337such configurations and is capable of automatic selection of a 2338"working" interface when needed. MAC assignment works as follows: 2339 2340Network interfaces are numbered eth0, eth1, eth2, ... Corresponding 2341MAC addresses can be stored in the environment as "ethaddr" (=>eth0), 2342"eth1addr" (=>eth1), "eth2addr", ... 2343 2344If the network interface stores some valid MAC address (for instance 2345in SROM), this is used as default address if there is NO correspon- 2346ding setting in the environment; if the corresponding environment 2347variable is set, this overrides the settings in the card; that means: 2348 2349o If the SROM has a valid MAC address, and there is no address in the 2350 environment, the SROM's address is used. 2351 2352o If there is no valid address in the SROM, and a definition in the 2353 environment exists, then the value from the environment variable is 2354 used. 2355 2356o If both the SROM and the environment contain a MAC address, and 2357 both addresses are the same, this MAC address is used. 2358 2359o If both the SROM and the environment contain a MAC address, and the 2360 addresses differ, the value from the environment is used and a 2361 warning is printed. 2362 2363o If neither SROM nor the environment contain a MAC address, an error 2364 is raised. 2365 2366 2367Image Formats: 2368============== 2369 2370The "boot" commands of this monitor operate on "image" files which 2371can be basicly anything, preceeded by a special header; see the 2372definitions in include/image.h for details; basicly, the header 2373defines the following image properties: 2374 2375* Target Operating System (Provisions for OpenBSD, NetBSD, FreeBSD, 2376 4.4BSD, Linux, SVR4, Esix, Solaris, Irix, SCO, Dell, NCR, VxWorks, 2377 LynxOS, pSOS, QNX, RTEMS, ARTOS; 2378 Currently supported: Linux, NetBSD, VxWorks, QNX, RTEMS, ARTOS, LynxOS). 2379* Target CPU Architecture (Provisions for Alpha, ARM, Intel x86, 2380 IA64, MIPS, NIOS, PowerPC, IBM S390, SuperH, Sparc, Sparc 64 Bit; 2381 Currently supported: ARM, Intel x86, MIPS, NIOS, PowerPC). 2382* Compression Type (uncompressed, gzip, bzip2) 2383* Load Address 2384* Entry Point 2385* Image Name 2386* Image Timestamp 2387 2388The header is marked by a special Magic Number, and both the header 2389and the data portions of the image are secured against corruption by 2390CRC32 checksums. 2391 2392 2393Linux Support: 2394============== 2395 2396Although U-Boot should support any OS or standalone application 2397easily, the main focus has always been on Linux during the design of 2398U-Boot. 2399 2400U-Boot includes many features that so far have been part of some 2401special "boot loader" code within the Linux kernel. Also, any 2402"initrd" images to be used are no longer part of one big Linux image; 2403instead, kernel and "initrd" are separate images. This implementation 2404serves several purposes: 2405 2406- the same features can be used for other OS or standalone 2407 applications (for instance: using compressed images to reduce the 2408 Flash memory footprint) 2409 2410- it becomes much easier to port new Linux kernel versions because 2411 lots of low-level, hardware dependent stuff are done by U-Boot 2412 2413- the same Linux kernel image can now be used with different "initrd" 2414 images; of course this also means that different kernel images can 2415 be run with the same "initrd". This makes testing easier (you don't 2416 have to build a new "zImage.initrd" Linux image when you just 2417 change a file in your "initrd"). Also, a field-upgrade of the 2418 software is easier now. 2419 2420 2421Linux HOWTO: 2422============ 2423 2424Porting Linux to U-Boot based systems: 2425--------------------------------------- 2426 2427U-Boot cannot save you from doing all the necessary modifications to 2428configure the Linux device drivers for use with your target hardware 2429(no, we don't intend to provide a full virtual machine interface to 2430Linux :-). 2431 2432But now you can ignore ALL boot loader code (in arch/ppc/mbxboot). 2433 2434Just make sure your machine specific header file (for instance 2435include/asm-ppc/tqm8xx.h) includes the same definition of the Board 2436Information structure as we define in include/u-boot.h, and make 2437sure that your definition of IMAP_ADDR uses the same value as your 2438U-Boot configuration in CFG_IMMR. 2439 2440 2441Configuring the Linux kernel: 2442----------------------------- 2443 2444No specific requirements for U-Boot. Make sure you have some root 2445device (initial ramdisk, NFS) for your target system. 2446 2447 2448Building a Linux Image: 2449----------------------- 2450 2451With U-Boot, "normal" build targets like "zImage" or "bzImage" are 2452not used. If you use recent kernel source, a new build target 2453"uImage" will exist which automatically builds an image usable by 2454U-Boot. Most older kernels also have support for a "pImage" target, 2455which was introduced for our predecessor project PPCBoot and uses a 2456100% compatible format. 2457 2458Example: 2459 2460 make TQM850L_config 2461 make oldconfig 2462 make dep 2463 make uImage 2464 2465The "uImage" build target uses a special tool (in 'tools/mkimage') to 2466encapsulate a compressed Linux kernel image with header information, 2467CRC32 checksum etc. for use with U-Boot. This is what we are doing: 2468 2469* build a standard "vmlinux" kernel image (in ELF binary format): 2470 2471* convert the kernel into a raw binary image: 2472 2473 ${CROSS_COMPILE}-objcopy -O binary \ 2474 -R .note -R .comment \ 2475 -S vmlinux linux.bin 2476 2477* compress the binary image: 2478 2479 gzip -9 linux.bin 2480 2481* package compressed binary image for U-Boot: 2482 2483 mkimage -A ppc -O linux -T kernel -C gzip \ 2484 -a 0 -e 0 -n "Linux Kernel Image" \ 2485 -d linux.bin.gz uImage 2486 2487 2488The "mkimage" tool can also be used to create ramdisk images for use 2489with U-Boot, either separated from the Linux kernel image, or 2490combined into one file. "mkimage" encapsulates the images with a 64 2491byte header containing information about target architecture, 2492operating system, image type, compression method, entry points, time 2493stamp, CRC32 checksums, etc. 2494 2495"mkimage" can be called in two ways: to verify existing images and 2496print the header information, or to build new images. 2497 2498In the first form (with "-l" option) mkimage lists the information 2499contained in the header of an existing U-Boot image; this includes 2500checksum verification: 2501 2502 tools/mkimage -l image 2503 -l ==> list image header information 2504 2505The second form (with "-d" option) is used to build a U-Boot image 2506from a "data file" which is used as image payload: 2507 2508 tools/mkimage -A arch -O os -T type -C comp -a addr -e ep \ 2509 -n name -d data_file image 2510 -A ==> set architecture to 'arch' 2511 -O ==> set operating system to 'os' 2512 -T ==> set image type to 'type' 2513 -C ==> set compression type 'comp' 2514 -a ==> set load address to 'addr' (hex) 2515 -e ==> set entry point to 'ep' (hex) 2516 -n ==> set image name to 'name' 2517 -d ==> use image data from 'datafile' 2518 2519Right now, all Linux kernels use the same load address (0x00000000), 2520but the entry point address depends on the kernel version: 2521 2522- 2.2.x kernels have the entry point at 0x0000000C, 2523- 2.3.x and later kernels have the entry point at 0x00000000. 2524 2525So a typical call to build a U-Boot image would read: 2526 2527 -> tools/mkimage -n '2.4.4 kernel for TQM850L' \ 2528 > -A ppc -O linux -T kernel -C gzip -a 0 -e 0 \ 2529 > -d /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/ppc/coffboot/vmlinux.gz \ 2530 > examples/uImage.TQM850L 2531 Image Name: 2.4.4 kernel for TQM850L 2532 Created: Wed Jul 19 02:34:59 2000 2533 Image Type: PowerPC Linux Kernel Image (gzip compressed) 2534 Data Size: 335725 Bytes = 327.86 kB = 0.32 MB 2535 Load Address: 0x00000000 2536 Entry Point: 0x00000000 2537 2538To verify the contents of the image (or check for corruption): 2539 2540 -> tools/mkimage -l examples/uImage.TQM850L 2541 Image Name: 2.4.4 kernel for TQM850L 2542 Created: Wed Jul 19 02:34:59 2000 2543 Image Type: PowerPC Linux Kernel Image (gzip compressed) 2544 Data Size: 335725 Bytes = 327.86 kB = 0.32 MB 2545 Load Address: 0x00000000 2546 Entry Point: 0x00000000 2547 2548NOTE: for embedded systems where boot time is critical you can trade 2549speed for memory and install an UNCOMPRESSED image instead: this 2550needs more space in Flash, but boots much faster since it does not 2551need to be uncompressed: 2552 2553 -> gunzip /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/ppc/coffboot/vmlinux.gz 2554 -> tools/mkimage -n '2.4.4 kernel for TQM850L' \ 2555 > -A ppc -O linux -T kernel -C none -a 0 -e 0 \ 2556 > -d /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/ppc/coffboot/vmlinux \ 2557 > examples/uImage.TQM850L-uncompressed 2558 Image Name: 2.4.4 kernel for TQM850L 2559 Created: Wed Jul 19 02:34:59 2000 2560 Image Type: PowerPC Linux Kernel Image (uncompressed) 2561 Data Size: 792160 Bytes = 773.59 kB = 0.76 MB 2562 Load Address: 0x00000000 2563 Entry Point: 0x00000000 2564 2565 2566Similar you can build U-Boot images from a 'ramdisk.image.gz' file 2567when your kernel is intended to use an initial ramdisk: 2568 2569 -> tools/mkimage -n 'Simple Ramdisk Image' \ 2570 > -A ppc -O linux -T ramdisk -C gzip \ 2571 > -d /LinuxPPC/images/SIMPLE-ramdisk.image.gz examples/simple-initrd 2572 Image Name: Simple Ramdisk Image 2573 Created: Wed Jan 12 14:01:50 2000 2574 Image Type: PowerPC Linux RAMDisk Image (gzip compressed) 2575 Data Size: 566530 Bytes = 553.25 kB = 0.54 MB 2576 Load Address: 0x00000000 2577 Entry Point: 0x00000000 2578 2579 2580Installing a Linux Image: 2581------------------------- 2582 2583To downloading a U-Boot image over the serial (console) interface, 2584you must convert the image to S-Record format: 2585 2586 objcopy -I binary -O srec examples/image examples/image.srec 2587 2588The 'objcopy' does not understand the information in the U-Boot 2589image header, so the resulting S-Record file will be relative to 2590address 0x00000000. To load it to a given address, you need to 2591specify the target address as 'offset' parameter with the 'loads' 2592command. 2593 2594Example: install the image to address 0x40100000 (which on the 2595TQM8xxL is in the first Flash bank): 2596 2597 => erase 40100000 401FFFFF 2598 2599 .......... done 2600 Erased 8 sectors 2601 2602 => loads 40100000 2603 ## Ready for S-Record download ... 2604 ~>examples/image.srec 2605 1 2 3 4 5 6 7 8 9 10 11 12 13 ... 2606 ... 2607 15989 15990 15991 15992 2608 [file transfer complete] 2609 [connected] 2610 ## Start Addr = 0x00000000 2611 2612 2613You can check the success of the download using the 'iminfo' command; 2614this includes a checksum verification so you can be sure no data 2615corruption happened: 2616 2617 => imi 40100000 2618 2619 ## Checking Image 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 2627 2628Boot Linux: 2629----------- 2630 2631The "bootm" command is used to boot an application that is stored in 2632memory (RAM or Flash). In case of a Linux kernel image, the contents 2633of the "bootargs" environment variable is passed to the kernel as 2634parameters. You can check and modify this variable using the 2635"printenv" and "setenv" commands: 2636 2637 2638 => printenv bootargs 2639 bootargs=root=/dev/ram 2640 2641 => setenv bootargs root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2 2642 2643 => printenv bootargs 2644 bootargs=root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2 2645 2646 => bootm 40020000 2647 ## Booting Linux kernel at 40020000 ... 2648 Image Name: 2.2.13 for NFS on TQM850L 2649 Image Type: PowerPC Linux Kernel Image (gzip compressed) 2650 Data Size: 381681 Bytes = 372 kB = 0 MB 2651 Load Address: 00000000 2652 Entry Point: 0000000c 2653 Verifying Checksum ... OK 2654 Uncompressing Kernel Image ... OK 2655 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 2656 Boot arguments: root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2 2657 time_init: decrementer frequency = 187500000/60 2658 Calibrating delay loop... 49.77 BogoMIPS 2659 Memory: 15208k available (700k kernel code, 444k data, 32k init) [c0000000,c1000000] 2660 ... 2661 2662If you want to boot a Linux kernel with initial ram disk, you pass 2663the memory addresses of both the kernel and the initrd image (PPBCOOT 2664format!) to the "bootm" command: 2665 2666 => imi 40100000 40200000 2667 2668 ## Checking Image at 40100000 ... 2669 Image Name: 2.2.13 for initrd on TQM850L 2670 Image Type: PowerPC Linux Kernel Image (gzip compressed) 2671 Data Size: 335725 Bytes = 327 kB = 0 MB 2672 Load Address: 00000000 2673 Entry Point: 0000000c 2674 Verifying Checksum ... OK 2675 2676 ## Checking Image at 40200000 ... 2677 Image Name: Simple Ramdisk Image 2678 Image Type: PowerPC Linux RAMDisk Image (gzip compressed) 2679 Data Size: 566530 Bytes = 553 kB = 0 MB 2680 Load Address: 00000000 2681 Entry Point: 00000000 2682 Verifying Checksum ... OK 2683 2684 => bootm 40100000 40200000 2685 ## Booting Linux kernel at 40100000 ... 2686 Image Name: 2.2.13 for initrd on TQM850L 2687 Image Type: PowerPC Linux Kernel Image (gzip compressed) 2688 Data Size: 335725 Bytes = 327 kB = 0 MB 2689 Load Address: 00000000 2690 Entry Point: 0000000c 2691 Verifying Checksum ... OK 2692 Uncompressing Kernel Image ... OK 2693 ## Loading RAMDisk Image at 40200000 ... 2694 Image Name: Simple Ramdisk Image 2695 Image Type: PowerPC Linux RAMDisk Image (gzip compressed) 2696 Data Size: 566530 Bytes = 553 kB = 0 MB 2697 Load Address: 00000000 2698 Entry Point: 00000000 2699 Verifying Checksum ... OK 2700 Loading Ramdisk ... OK 2701 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 2702 Boot arguments: root=/dev/ram 2703 time_init: decrementer frequency = 187500000/60 2704 Calibrating delay loop... 49.77 BogoMIPS 2705 ... 2706 RAMDISK: Compressed image found at block 0 2707 VFS: Mounted root (ext2 filesystem). 2708 2709 bash# 2710 2711More About U-Boot Image Types: 2712------------------------------ 2713 2714U-Boot supports the following image types: 2715 2716 "Standalone Programs" are directly runnable in the environment 2717 provided by U-Boot; it is expected that (if they behave 2718 well) you can continue to work in U-Boot after return from 2719 the Standalone Program. 2720 "OS Kernel Images" are usually images of some Embedded OS which 2721 will take over control completely. Usually these programs 2722 will install their own set of exception handlers, device 2723 drivers, set up the MMU, etc. - this means, that you cannot 2724 expect to re-enter U-Boot except by resetting the CPU. 2725 "RAMDisk Images" are more or less just data blocks, and their 2726 parameters (address, size) are passed to an OS kernel that is 2727 being started. 2728 "Multi-File Images" contain several images, typically an OS 2729 (Linux) kernel image and one or more data images like 2730 RAMDisks. This construct is useful for instance when you want 2731 to boot over the network using BOOTP etc., where the boot 2732 server provides just a single image file, but you want to get 2733 for instance an OS kernel and a RAMDisk image. 2734 2735 "Multi-File Images" start with a list of image sizes, each 2736 image size (in bytes) specified by an "uint32_t" in network 2737 byte order. This list is terminated by an "(uint32_t)0". 2738 Immediately after the terminating 0 follow the images, one by 2739 one, all aligned on "uint32_t" boundaries (size rounded up to 2740 a multiple of 4 bytes). 2741 2742 "Firmware Images" are binary images containing firmware (like 2743 U-Boot or FPGA images) which usually will be programmed to 2744 flash memory. 2745 2746 "Script files" are command sequences that will be executed by 2747 U-Boot's command interpreter; this feature is especially 2748 useful when you configure U-Boot to use a real shell (hush) 2749 as command interpreter. 2750 2751 2752Standalone HOWTO: 2753================= 2754 2755One of the features of U-Boot is that you can dynamically load and 2756run "standalone" applications, which can use some resources of 2757U-Boot like console I/O functions or interrupt services. 2758 2759Two simple examples are included with the sources: 2760 2761"Hello World" Demo: 2762------------------- 2763 2764'examples/hello_world.c' contains a small "Hello World" Demo 2765application; it is automatically compiled when you build U-Boot. 2766It's configured to run at address 0x00040004, so you can play with it 2767like that: 2768 2769 => loads 2770 ## Ready for S-Record download ... 2771 ~>examples/hello_world.srec 2772 1 2 3 4 5 6 7 8 9 10 11 ... 2773 [file transfer complete] 2774 [connected] 2775 ## Start Addr = 0x00040004 2776 2777 => go 40004 Hello World! This is a test. 2778 ## Starting application at 0x00040004 ... 2779 Hello World 2780 argc = 7 2781 argv[0] = "40004" 2782 argv[1] = "Hello" 2783 argv[2] = "World!" 2784 argv[3] = "This" 2785 argv[4] = "is" 2786 argv[5] = "a" 2787 argv[6] = "test." 2788 argv[7] = "<NULL>" 2789 Hit any key to exit ... 2790 2791 ## Application terminated, rc = 0x0 2792 2793Another example, which demonstrates how to register a CPM interrupt 2794handler with the U-Boot code, can be found in 'examples/timer.c'. 2795Here, a CPM timer is set up to generate an interrupt every second. 2796The interrupt service routine is trivial, just printing a '.' 2797character, but this is just a demo program. The application can be 2798controlled by the following keys: 2799 2800 ? - print current values og the CPM Timer registers 2801 b - enable interrupts and start timer 2802 e - stop timer and disable interrupts 2803 q - quit application 2804 2805 => loads 2806 ## Ready for S-Record download ... 2807 ~>examples/timer.srec 2808 1 2 3 4 5 6 7 8 9 10 11 ... 2809 [file transfer complete] 2810 [connected] 2811 ## Start Addr = 0x00040004 2812 2813 => go 40004 2814 ## Starting application at 0x00040004 ... 2815 TIMERS=0xfff00980 2816 Using timer 1 2817 tgcr @ 0xfff00980, tmr @ 0xfff00990, trr @ 0xfff00994, tcr @ 0xfff00998, tcn @ 0xfff0099c, ter @ 0xfff009b0 2818 2819Hit 'b': 2820 [q, b, e, ?] Set interval 1000000 us 2821 Enabling timer 2822Hit '?': 2823 [q, b, e, ?] ........ 2824 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0xef6, ter=0x0 2825Hit '?': 2826 [q, b, e, ?] . 2827 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x2ad4, ter=0x0 2828Hit '?': 2829 [q, b, e, ?] . 2830 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x1efc, ter=0x0 2831Hit '?': 2832 [q, b, e, ?] . 2833 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x169d, ter=0x0 2834Hit 'e': 2835 [q, b, e, ?] ...Stopping timer 2836Hit 'q': 2837 [q, b, e, ?] ## Application terminated, rc = 0x0 2838 2839 2840Minicom warning: 2841================ 2842 2843Over time, many people have reported problems when trying to use the 2844"minicom" terminal emulation program for serial download. I (wd) 2845consider minicom to be broken, and recommend not to use it. Under 2846Unix, I recommend to use C-Kermit for general purpose use (and 2847especially for kermit binary protocol download ("loadb" command), and 2848use "cu" for S-Record download ("loads" command). 2849 2850Nevertheless, if you absolutely want to use it try adding this 2851configuration to your "File transfer protocols" section: 2852 2853 Name Program Name U/D FullScr IO-Red. Multi 2854 X kermit /usr/bin/kermit -i -l %l -s Y U Y N N 2855 Y kermit /usr/bin/kermit -i -l %l -r N D Y N N 2856 2857 2858NetBSD Notes: 2859============= 2860 2861Starting at version 0.9.2, U-Boot supports NetBSD both as host 2862(build U-Boot) and target system (boots NetBSD/mpc8xx). 2863 2864Building requires a cross environment; it is known to work on 2865NetBSD/i386 with the cross-powerpc-netbsd-1.3 package (you will also 2866need gmake since the Makefiles are not compatible with BSD make). 2867Note that the cross-powerpc package does not install include files; 2868attempting to build U-Boot will fail because <machine/ansi.h> is 2869missing. This file has to be installed and patched manually: 2870 2871 # cd /usr/pkg/cross/powerpc-netbsd/include 2872 # mkdir powerpc 2873 # ln -s powerpc machine 2874 # cp /usr/src/sys/arch/powerpc/include/ansi.h powerpc/ansi.h 2875 # ${EDIT} powerpc/ansi.h ## must remove __va_list, _BSD_VA_LIST 2876 2877Native builds *don't* work due to incompatibilities between native 2878and U-Boot include files. 2879 2880Booting assumes that (the first part of) the image booted is a 2881stage-2 loader which in turn loads and then invokes the kernel 2882proper. Loader sources will eventually appear in the NetBSD source 2883tree (probably in sys/arc/mpc8xx/stand/u-boot_stage2/); in the 2884meantime, send mail to bruno@exet-ag.de and/or wd@denx.de for 2885details. 2886 2887 2888Implementation Internals: 2889========================= 2890 2891The following is not intended to be a complete description of every 2892implementation detail. However, it should help to understand the 2893inner workings of U-Boot and make it easier to port it to custom 2894hardware. 2895 2896 2897Initial Stack, Global Data: 2898--------------------------- 2899 2900The implementation of U-Boot is complicated by the fact that U-Boot 2901starts running out of ROM (flash memory), usually without access to 2902system RAM (because the memory controller is not initialized yet). 2903This means that we don't have writable Data or BSS segments, and BSS 2904is not initialized as zero. To be able to get a C environment working 2905at all, we have to allocate at least a minimal stack. Implementation 2906options for this are defined and restricted by the CPU used: Some CPU 2907models provide on-chip memory (like the IMMR area on MPC8xx and 2908MPC826x processors), on others (parts of) the data cache can be 2909locked as (mis-) used as memory, etc. 2910 2911 Chris Hallinan posted a good summary of these issues to the 2912 u-boot-users mailing list: 2913 2914 Subject: RE: [U-Boot-Users] RE: More On Memory Bank x (nothingness)? 2915 From: "Chris Hallinan" <clh@net1plus.com> 2916 Date: Mon, 10 Feb 2003 16:43:46 -0500 (22:43 MET) 2917 ... 2918 2919 Correct me if I'm wrong, folks, but the way I understand it 2920 is this: Using DCACHE as initial RAM for Stack, etc, does not 2921 require any physical RAM backing up the cache. The cleverness 2922 is that the cache is being used as a temporary supply of 2923 necessary storage before the SDRAM controller is setup. It's 2924 beyond the scope of this list to expain the details, but you 2925 can see how this works by studying the cache architecture and 2926 operation in the architecture and processor-specific manuals. 2927 2928 OCM is On Chip Memory, which I believe the 405GP has 4K. It 2929 is another option for the system designer to use as an 2930 initial stack/ram area prior to SDRAM being available. Either 2931 option should work for you. Using CS 4 should be fine if your 2932 board designers haven't used it for something that would 2933 cause you grief during the initial boot! It is frequently not 2934 used. 2935 2936 CFG_INIT_RAM_ADDR should be somewhere that won't interfere 2937 with your processor/board/system design. The default value 2938 you will find in any recent u-boot distribution in 2939 Walnut405.h should work for you. I'd set it to a value larger 2940 than your SDRAM module. If you have a 64MB SDRAM module, set 2941 it above 400_0000. Just make sure your board has no resources 2942 that are supposed to respond to that address! That code in 2943 start.S has been around a while and should work as is when 2944 you get the config right. 2945 2946 -Chris Hallinan 2947 DS4.COM, Inc. 2948 2949It is essential to remember this, since it has some impact on the C 2950code for the initialization procedures: 2951 2952* Initialized global data (data segment) is read-only. Do not attempt 2953 to write it. 2954 2955* Do not use any unitialized global data (or implicitely initialized 2956 as zero data - BSS segment) at all - this is undefined, initiali- 2957 zation is performed later (when relocating to RAM). 2958 2959* Stack space is very limited. Avoid big data buffers or things like 2960 that. 2961 2962Having only the stack as writable memory limits means we cannot use 2963normal global data to share information beween the code. But it 2964turned out that the implementation of U-Boot can be greatly 2965simplified by making a global data structure (gd_t) available to all 2966functions. We could pass a pointer to this data as argument to _all_ 2967functions, but this would bloat the code. Instead we use a feature of 2968the GCC compiler (Global Register Variables) to share the data: we 2969place a pointer (gd) to the global data into a register which we 2970reserve for this purpose. 2971 2972When choosing a register for such a purpose we are restricted by the 2973relevant (E)ABI specifications for the current architecture, and by 2974GCC's implementation. 2975 2976For PowerPC, the following registers have specific use: 2977 R1: stack pointer 2978 R2: TOC pointer 2979 R3-R4: parameter passing and return values 2980 R5-R10: parameter passing 2981 R13: small data area pointer 2982 R30: GOT pointer 2983 R31: frame pointer 2984 2985 (U-Boot also uses R14 as internal GOT pointer.) 2986 2987 ==> U-Boot will use R29 to hold a pointer to the global data 2988 2989 Note: on PPC, we could use a static initializer (since the 2990 address of the global data structure is known at compile time), 2991 but it turned out that reserving a register results in somewhat 2992 smaller code - although the code savings are not that big (on 2993 average for all boards 752 bytes for the whole U-Boot image, 2994 624 text + 127 data). 2995 2996On ARM, the following registers are used: 2997 2998 R0: function argument word/integer result 2999 R1-R3: function argument word 3000 R9: GOT pointer 3001 R10: stack limit (used only if stack checking if enabled) 3002 R11: argument (frame) pointer 3003 R12: temporary workspace 3004 R13: stack pointer 3005 R14: link register 3006 R15: program counter 3007 3008 ==> U-Boot will use R8 to hold a pointer to the global data 3009 3010 3011Memory Management: 3012------------------ 3013 3014U-Boot runs in system state and uses physical addresses, i.e. the 3015MMU is not used either for address mapping nor for memory protection. 3016 3017The available memory is mapped to fixed addresses using the memory 3018controller. In this process, a contiguous block is formed for each 3019memory type (Flash, SDRAM, SRAM), even when it consists of several 3020physical memory banks. 3021 3022U-Boot is installed in the first 128 kB of the first Flash bank (on 3023TQM8xxL modules this is the range 0x40000000 ... 0x4001FFFF). After 3024booting and sizing and initializing DRAM, the code relocates itself 3025to the upper end of DRAM. Immediately below the U-Boot code some 3026memory is reserved for use by malloc() [see CFG_MALLOC_LEN 3027configuration setting]. Below that, a structure with global Board 3028Info data is placed, followed by the stack (growing downward). 3029 3030Additionally, some exception handler code is copied to the low 8 kB 3031of DRAM (0x00000000 ... 0x00001FFF). 3032 3033So a typical memory configuration with 16 MB of DRAM could look like 3034this: 3035 3036 0x0000 0000 Exception Vector code 3037 : 3038 0x0000 1FFF 3039 0x0000 2000 Free for Application Use 3040 : 3041 : 3042 3043 : 3044 : 3045 0x00FB FF20 Monitor Stack (Growing downward) 3046 0x00FB FFAC Board Info Data and permanent copy of global data 3047 0x00FC 0000 Malloc Arena 3048 : 3049 0x00FD FFFF 3050 0x00FE 0000 RAM Copy of Monitor Code 3051 ... eventually: LCD or video framebuffer 3052 ... eventually: pRAM (Protected RAM - unchanged by reset) 3053 0x00FF FFFF [End of RAM] 3054 3055 3056System Initialization: 3057---------------------- 3058 3059In the reset configuration, U-Boot starts at the reset entry point 3060(on most PowerPC systens at address 0x00000100). Because of the reset 3061configuration for CS0# this is a mirror of the onboard Flash memory. 3062To be able to re-map memory U-Boot then jumps to its link address. 3063To be able to implement the initialization code in C, a (small!) 3064initial stack is set up in the internal Dual Ported RAM (in case CPUs 3065which provide such a feature like MPC8xx or MPC8260), or in a locked 3066part of the data cache. After that, U-Boot initializes the CPU core, 3067the caches and the SIU. 3068 3069Next, all (potentially) available memory banks are mapped using a 3070preliminary mapping. For example, we put them on 512 MB boundaries 3071(multiples of 0x20000000: SDRAM on 0x00000000 and 0x20000000, Flash 3072on 0x40000000 and 0x60000000, SRAM on 0x80000000). Then UPM A is 3073programmed for SDRAM access. Using the temporary configuration, a 3074simple memory test is run that determines the size of the SDRAM 3075banks. 3076 3077When there is more than one SDRAM bank, and the banks are of 3078different size, the largest is mapped first. For equal size, the first 3079bank (CS2#) is mapped first. The first mapping is always for address 30800x00000000, with any additional banks following immediately to create 3081contiguous memory starting from 0. 3082 3083Then, the monitor installs itself at the upper end of the SDRAM area 3084and allocates memory for use by malloc() and for the global Board 3085Info data; also, the exception vector code is copied to the low RAM 3086pages, and the final stack is set up. 3087 3088Only after this relocation will you have a "normal" C environment; 3089until that you are restricted in several ways, mostly because you are 3090running from ROM, and because the code will have to be relocated to a 3091new address in RAM. 3092 3093 3094U-Boot Porting Guide: 3095---------------------- 3096 3097[Based on messages by Jerry Van Baren in the U-Boot-Users mailing 3098list, October 2002] 3099 3100 3101int main (int argc, char *argv[]) 3102{ 3103 sighandler_t no_more_time; 3104 3105 signal (SIGALRM, no_more_time); 3106 alarm (PROJECT_DEADLINE - toSec (3 * WEEK)); 3107 3108 if (available_money > available_manpower) { 3109 pay consultant to port U-Boot; 3110 return 0; 3111 } 3112 3113 Download latest U-Boot source; 3114 3115 Subscribe to u-boot-users mailing list; 3116 3117 if (clueless) { 3118 email ("Hi, I am new to U-Boot, how do I get started?"); 3119 } 3120 3121 while (learning) { 3122 Read the README file in the top level directory; 3123 Read http://www.denx.de/twiki/bin/view/DULG/Manual ; 3124 Read the source, Luke; 3125 } 3126 3127 if (available_money > toLocalCurrency ($2500)) { 3128 Buy a BDI2000; 3129 } else { 3130 Add a lot of aggravation and time; 3131 } 3132 3133 Create your own board support subdirectory; 3134 3135 Create your own board config file; 3136 3137 while (!running) { 3138 do { 3139 Add / modify source code; 3140 } until (compiles); 3141 Debug; 3142 if (clueless) 3143 email ("Hi, I am having problems..."); 3144 } 3145 Send patch file to Wolfgang; 3146 3147 return 0; 3148} 3149 3150void no_more_time (int sig) 3151{ 3152 hire_a_guru(); 3153} 3154 3155 3156Coding Standards: 3157----------------- 3158 3159All contributions to U-Boot should conform to the Linux kernel 3160coding style; see the file "Documentation/CodingStyle" in your Linux 3161kernel source directory. 3162 3163Please note that U-Boot is implemented in C (and to some small parts 3164in Assembler); no C++ is used, so please do not use C++ style 3165comments (//) in your code. 3166 3167Please also stick to the following formatting rules: 3168- remove any trailing white space 3169- use TAB characters for indentation, not spaces 3170- make sure NOT to use DOS '\r\n' line feeds 3171- do not add more than 2 empty lines to source files 3172- do not add trailing empty lines to source files 3173 3174Submissions which do not conform to the standards may be returned 3175with a request to reformat the changes. 3176 3177 3178Submitting Patches: 3179------------------- 3180 3181Since the number of patches for U-Boot is growing, we need to 3182establish some rules. Submissions which do not conform to these rules 3183may be rejected, even when they contain important and valuable stuff. 3184 3185 3186When you send a patch, please include the following information with 3187it: 3188 3189* For bug fixes: a description of the bug and how your patch fixes 3190 this bug. Please try to include a way of demonstrating that the 3191 patch actually fixes something. 3192 3193* For new features: a description of the feature and your 3194 implementation. 3195 3196* A CHANGELOG entry as plaintext (separate from the patch) 3197 3198* For major contributions, your entry to the CREDITS file 3199 3200* When you add support for a new board, don't forget to add this 3201 board to the MAKEALL script, too. 3202 3203* If your patch adds new configuration options, don't forget to 3204 document these in the README file. 3205 3206* The patch itself. If you are accessing the CVS repository use "cvs 3207 update; cvs diff -puRN"; else, use "diff -purN OLD NEW". If your 3208 version of diff does not support these options, then get the latest 3209 version of GNU diff. 3210 3211 The current directory when running this command shall be the top 3212 level directory of the U-Boot source tree, or it's parent directory 3213 (i. e. please make sure that your patch includes sufficient 3214 directory information for the affected files). 3215 3216 We accept patches as plain text, MIME attachments or as uuencoded 3217 gzipped text. 3218 3219* If one logical set of modifications affects or creates several 3220 files, all these changes shall be submitted in a SINGLE patch file. 3221 3222* Changesets that contain different, unrelated modifications shall be 3223 submitted as SEPARATE patches, one patch per changeset. 3224 3225 3226Notes: 3227 3228* Before sending the patch, run the MAKEALL script on your patched 3229 source tree and make sure that no errors or warnings are reported 3230 for any of the boards. 3231 3232* Keep your modifications to the necessary minimum: A patch 3233 containing several unrelated changes or arbitrary reformats will be 3234 returned with a request to re-formatting / split it. 3235 3236* If you modify existing code, make sure that your new code does not 3237 add to the memory footprint of the code ;-) Small is beautiful! 3238 When adding new features, these should compile conditionally only 3239 (using #ifdef), and the resulting code with the new feature 3240 disabled must not need more memory than the old code without your 3241 modification. 3242