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_ADS860, CONFIG_AMX860, 250 CONFIG_AR405, CONFIG_BAB7xx, CONFIG_c2mon, 251 CONFIG_CANBT, CONFIG_CCM, CONFIG_CMI, 252 CONFIG_cogent_mpc8260, CONFIG_cogent_mpc8xx, CONFIG_CPCI405, 253 CONFIG_CPCI4052, CONFIG_CPCIISER4, CONFIG_CPU86, 254 CONFIG_CRAYL1, CONFIG_CU824, CONFIG_DASA_SIM, 255 CONFIG_DB64360, CONFIG_DB64460, CONFIG_DU405, 256 CONFIG_DUET_ADS, CONFIG_EBONY, CONFIG_ELPPC, 257 CONFIG_ELPT860, CONFIG_ep8260, CONFIG_ERIC, 258 CONFIG_ESTEEM192E, CONFIG_ETX094, CONFIG_EVB64260, 259 CONFIG_FADS823, CONFIG_FADS850SAR, CONFIG_FADS860T, 260 CONFIG_FLAGADM, CONFIG_FPS850L, CONFIG_FPS860L, 261 CONFIG_GEN860T, CONFIG_GENIETV, CONFIG_GTH, 262 CONFIG_gw8260, CONFIG_hermes, CONFIG_hymod, 263 CONFIG_IAD210, CONFIG_ICU862, CONFIG_IP860, 264 CONFIG_IPHASE4539, CONFIG_IVML24, CONFIG_IVML24_128, 265 CONFIG_IVML24_256, CONFIG_IVMS8, CONFIG_IVMS8_128, 266 CONFIG_IVMS8_256, CONFIG_JSE, CONFIG_LANTEC, 267 CONFIG_lwmon, CONFIG_MBX, CONFIG_MBX860T, 268 CONFIG_MHPC, CONFIG_MIP405, CONFIG_MOUSSE, 269 CONFIG_MPC8260ADS, CONFIG_MPC8540ADS, CONFIG_MPC8560ADS, 270 CONFIG_MUSENKI, CONFIG_MVS1, CONFIG_NETPHONE, 271 CONFIG_NETTA, CONFIG_NETVIA, CONFIG_NX823, 272 CONFIG_OCRTC, CONFIG_ORSG, CONFIG_OXC, 273 CONFIG_PCI405, CONFIG_PCIPPC2, CONFIG_PCIPPC6, 274 CONFIG_pcu_e, CONFIG_PIP405, CONFIG_PM826, 275 CONFIG_ppmc8260, CONFIG_QS823, CONFIG_QS850, 276 CONFIG_QS860T, CONFIG_RBC823, CONFIG_RPXClassic, 277 CONFIG_RPXlite, CONFIG_RPXsuper, CONFIG_rsdproto, 278 CONFIG_sacsng, CONFIG_Sandpoint8240, CONFIG_Sandpoint8245, 279 CONFIG_sbc8260, CONFIG_SM850, CONFIG_SPD823TS, 280 CONFIG_SXNI855T, CONFIG_TQM823L, CONFIG_TQM8260, 281 CONFIG_TQM850L, CONFIG_TQM855L, CONFIG_TQM860L, 282 CONFIG_TTTech, CONFIG_UTX8245, CONFIG_V37, 283 CONFIG_W7OLMC, CONFIG_W7OLMG, CONFIG_WALNUT405, 284 CONFIG_ZPC1900, CONFIG_ZUMA, 285 286 ARM based boards: 287 ----------------- 288 289 CONFIG_AT91RM9200DK, CONFIG_DNP1110, CONFIG_EP7312, 290 CONFIG_H2_OMAP1610, CONFIG_HHP_CRADLE, CONFIG_IMPA7, 291 CONFIG_INNOVATOROMAP1510, CONFIG_INNOVATOROMAP1610, CONFIG_LART, 292 CONFIG_LUBBOCK, CONFIG_SHANNON, CONFIG_SMDK2400, 293 CONFIG_SMDK2410, CONFIG_TRAB, CONFIG_VCMA9, 294 295 296- CPU Module Type: (if CONFIG_COGENT is defined) 297 Define exactly one of 298 CONFIG_CMA286_60_OLD 299--- FIXME --- not tested yet: 300 CONFIG_CMA286_60, CONFIG_CMA286_21, CONFIG_CMA286_60P, 301 CONFIG_CMA287_23, CONFIG_CMA287_50 302 303- Motherboard Type: (if CONFIG_COGENT is defined) 304 Define exactly one of 305 CONFIG_CMA101, CONFIG_CMA102 306 307- Motherboard I/O Modules: (if CONFIG_COGENT is defined) 308 Define one or more of 309 CONFIG_CMA302 310 311- Motherboard Options: (if CONFIG_CMA101 or CONFIG_CMA102 are defined) 312 Define one or more of 313 CONFIG_LCD_HEARTBEAT - update a character position on 314 the lcd display every second with 315 a "rotator" |\-/|\-/ 316 317- Board flavour: (if CONFIG_MPC8260ADS is defined) 318 CONFIG_ADSTYPE 319 Possible values are: 320 CFG_8260ADS - original MPC8260ADS 321 CFG_8266ADS - MPC8266ADS 322 CFG_PQ2FADS - PQ2FADS-ZU or PQ2FADS-VR 323 CFG_8272ADS - MPC8272ADS 324 325- MPC824X Family Member (if CONFIG_MPC824X is defined) 326 Define exactly one of 327 CONFIG_MPC8240, CONFIG_MPC8245 328 329- 8xx CPU Options: (if using an MPC8xx cpu) 330 Define one or more of 331 CONFIG_8xx_GCLK_FREQ - if get_gclk_freq() cannot work 332 e.g. if there is no 32KHz 333 reference PIT/RTC clock 334 335- 859/866 CPU options: (if using a MPC859 or MPC866 CPU): 336 CFG_866_OSCCLK 337 CFG_866_CPUCLK_MIN 338 CFG_866_CPUCLK_MAX 339 CFG_866_CPUCLK_DEFAULT 340 See doc/README.MPC866 341 342 CFG_MEASURE_CPUCLK 343 344 Define this to measure the actual CPU clock instead 345 of relying on the correctness of the configured 346 values. Mostly useful for board bringup to make sure 347 the PLL is locked at the intended frequency. Note 348 that this requires a (stable) reference clock (32 kHz 349 RTC clock), 350 351- Linux Kernel Interface: 352 CONFIG_CLOCKS_IN_MHZ 353 354 U-Boot stores all clock information in Hz 355 internally. For binary compatibility with older Linux 356 kernels (which expect the clocks passed in the 357 bd_info data to be in MHz) the environment variable 358 "clocks_in_mhz" can be defined so that U-Boot 359 converts clock data to MHZ before passing it to the 360 Linux kernel. 361 When CONFIG_CLOCKS_IN_MHZ is defined, a definition of 362 "clocks_in_mhz=1" is automatically included in the 363 default environment. 364 365 CONFIG_MEMSIZE_IN_BYTES [relevant for MIPS only] 366 367 When transfering memsize parameter to linux, some versions 368 expect it to be in bytes, others in MB. 369 Define CONFIG_MEMSIZE_IN_BYTES to make it in bytes. 370 371- Console Interface: 372 Depending on board, define exactly one serial port 373 (like CONFIG_8xx_CONS_SMC1, CONFIG_8xx_CONS_SMC2, 374 CONFIG_8xx_CONS_SCC1, ...), or switch off the serial 375 console by defining CONFIG_8xx_CONS_NONE 376 377 Note: if CONFIG_8xx_CONS_NONE is defined, the serial 378 port routines must be defined elsewhere 379 (i.e. serial_init(), serial_getc(), ...) 380 381 CONFIG_CFB_CONSOLE 382 Enables console device for a color framebuffer. Needs following 383 defines (cf. smiLynxEM, i8042, board/eltec/bab7xx) 384 VIDEO_FB_LITTLE_ENDIAN graphic memory organisation 385 (default big endian) 386 VIDEO_HW_RECTFILL graphic chip supports 387 rectangle fill 388 (cf. smiLynxEM) 389 VIDEO_HW_BITBLT graphic chip supports 390 bit-blit (cf. smiLynxEM) 391 VIDEO_VISIBLE_COLS visible pixel columns 392 (cols=pitch) 393 VIDEO_VISIBLE_ROWS visible pixel rows 394 VIDEO_PIXEL_SIZE bytes per pixel 395 VIDEO_DATA_FORMAT graphic data format 396 (0-5, cf. cfb_console.c) 397 VIDEO_FB_ADRS framebuffer address 398 VIDEO_KBD_INIT_FCT keyboard int fct 399 (i.e. i8042_kbd_init()) 400 VIDEO_TSTC_FCT test char fct 401 (i.e. i8042_tstc) 402 VIDEO_GETC_FCT get char fct 403 (i.e. i8042_getc) 404 CONFIG_CONSOLE_CURSOR cursor drawing on/off 405 (requires blink timer 406 cf. i8042.c) 407 CFG_CONSOLE_BLINK_COUNT blink interval (cf. i8042.c) 408 CONFIG_CONSOLE_TIME display time/date info in 409 upper right corner 410 (requires CFG_CMD_DATE) 411 CONFIG_VIDEO_LOGO display Linux logo in 412 upper left corner 413 CONFIG_VIDEO_BMP_LOGO use bmp_logo.h instead of 414 linux_logo.h for logo. 415 Requires CONFIG_VIDEO_LOGO 416 CONFIG_CONSOLE_EXTRA_INFO 417 addional board info beside 418 the logo 419 420 When CONFIG_CFB_CONSOLE is defined, video console is 421 default i/o. Serial console can be forced with 422 environment 'console=serial'. 423 424 When CONFIG_SILENT_CONSOLE is defined, all console 425 messages (by U-Boot and Linux!) can be silenced with 426 the "silent" environment variable. See 427 doc/README.silent for more information. 428 429- Console Baudrate: 430 CONFIG_BAUDRATE - in bps 431 Select one of the baudrates listed in 432 CFG_BAUDRATE_TABLE, see below. 433 CFG_BRGCLK_PRESCALE, baudrate prescale 434 435- Interrupt driven serial port input: 436 CONFIG_SERIAL_SOFTWARE_FIFO 437 438 PPC405GP only. 439 Use an interrupt handler for receiving data on the 440 serial port. It also enables using hardware handshake 441 (RTS/CTS) and UART's built-in FIFO. Set the number of 442 bytes the interrupt driven input buffer should have. 443 444 Leave undefined to disable this feature, including 445 disable the buffer and hardware handshake. 446 447- Console UART Number: 448 CONFIG_UART1_CONSOLE 449 450 IBM PPC4xx only. 451 If defined internal UART1 (and not UART0) is used 452 as default U-Boot console. 453 454- Boot Delay: CONFIG_BOOTDELAY - in seconds 455 Delay before automatically booting the default image; 456 set to -1 to disable autoboot. 457 458 See doc/README.autoboot for these options that 459 work with CONFIG_BOOTDELAY. None are required. 460 CONFIG_BOOT_RETRY_TIME 461 CONFIG_BOOT_RETRY_MIN 462 CONFIG_AUTOBOOT_KEYED 463 CONFIG_AUTOBOOT_PROMPT 464 CONFIG_AUTOBOOT_DELAY_STR 465 CONFIG_AUTOBOOT_STOP_STR 466 CONFIG_AUTOBOOT_DELAY_STR2 467 CONFIG_AUTOBOOT_STOP_STR2 468 CONFIG_ZERO_BOOTDELAY_CHECK 469 CONFIG_RESET_TO_RETRY 470 471- Autoboot Command: 472 CONFIG_BOOTCOMMAND 473 Only needed when CONFIG_BOOTDELAY is enabled; 474 define a command string that is automatically executed 475 when no character is read on the console interface 476 within "Boot Delay" after reset. 477 478 CONFIG_BOOTARGS 479 This can be used to pass arguments to the bootm 480 command. The value of CONFIG_BOOTARGS goes into the 481 environment value "bootargs". 482 483 CONFIG_RAMBOOT and CONFIG_NFSBOOT 484 The value of these goes into the environment as 485 "ramboot" and "nfsboot" respectively, and can be used 486 as a convenience, when switching between booting from 487 ram and nfs. 488 489- Pre-Boot Commands: 490 CONFIG_PREBOOT 491 492 When this option is #defined, the existence of the 493 environment variable "preboot" will be checked 494 immediately before starting the CONFIG_BOOTDELAY 495 countdown and/or running the auto-boot command resp. 496 entering interactive mode. 497 498 This feature is especially useful when "preboot" is 499 automatically generated or modified. For an example 500 see the LWMON board specific code: here "preboot" is 501 modified when the user holds down a certain 502 combination of keys on the (special) keyboard when 503 booting the systems 504 505- Serial Download Echo Mode: 506 CONFIG_LOADS_ECHO 507 If defined to 1, all characters received during a 508 serial download (using the "loads" command) are 509 echoed back. This might be needed by some terminal 510 emulations (like "cu"), but may as well just take 511 time on others. This setting #define's the initial 512 value of the "loads_echo" environment variable. 513 514- Kgdb Serial Baudrate: (if CFG_CMD_KGDB is defined) 515 CONFIG_KGDB_BAUDRATE 516 Select one of the baudrates listed in 517 CFG_BAUDRATE_TABLE, see below. 518 519- Monitor Functions: 520 CONFIG_COMMANDS 521 Most monitor functions can be selected (or 522 de-selected) by adjusting the definition of 523 CONFIG_COMMANDS; to select individual functions, 524 #define CONFIG_COMMANDS by "OR"ing any of the 525 following values: 526 527 #define enables commands: 528 ------------------------- 529 CFG_CMD_ASKENV * ask for env variable 530 CFG_CMD_AUTOSCRIPT Autoscript Support 531 CFG_CMD_BDI bdinfo 532 CFG_CMD_BEDBUG Include BedBug Debugger 533 CFG_CMD_BMP * BMP support 534 CFG_CMD_BOOTD bootd 535 CFG_CMD_CACHE icache, dcache 536 CFG_CMD_CONSOLE coninfo 537 CFG_CMD_DATE * support for RTC, date/time... 538 CFG_CMD_DHCP DHCP support 539 CFG_CMD_DIAG * Diagnostics 540 CFG_CMD_DOC * Disk-On-Chip Support 541 CFG_CMD_DTT Digital Therm and Thermostat 542 CFG_CMD_ECHO * echo arguments 543 CFG_CMD_EEPROM * EEPROM read/write support 544 CFG_CMD_ELF bootelf, bootvx 545 CFG_CMD_ENV saveenv 546 CFG_CMD_FDC * Floppy Disk Support 547 CFG_CMD_FAT FAT partition support 548 CFG_CMD_FDOS * Dos diskette Support 549 CFG_CMD_FLASH flinfo, erase, protect 550 CFG_CMD_FPGA FPGA device initialization support 551 CFG_CMD_HWFLOW * RTS/CTS hw flow control 552 CFG_CMD_I2C * I2C serial bus support 553 CFG_CMD_IDE * IDE harddisk support 554 CFG_CMD_IMI iminfo 555 CFG_CMD_IMLS List all found images 556 CFG_CMD_IMMAP * IMMR dump support 557 CFG_CMD_IRQ * irqinfo 558 CFG_CMD_ITEST * Integer/string test of 2 values 559 CFG_CMD_JFFS2 * JFFS2 Support 560 CFG_CMD_KGDB * kgdb 561 CFG_CMD_LOADB loadb 562 CFG_CMD_LOADS loads 563 CFG_CMD_MEMORY md, mm, nm, mw, cp, cmp, crc, base, 564 loop, mtest 565 CFG_CMD_MISC Misc functions like sleep etc 566 CFG_CMD_MMC MMC memory mapped support 567 CFG_CMD_MII MII utility commands 568 CFG_CMD_NAND * NAND support 569 CFG_CMD_NET bootp, tftpboot, rarpboot 570 CFG_CMD_PCI * pciinfo 571 CFG_CMD_PCMCIA * PCMCIA support 572 CFG_CMD_PING * send ICMP ECHO_REQUEST to network host 573 CFG_CMD_PORTIO * Port I/O 574 CFG_CMD_REGINFO * Register dump 575 CFG_CMD_RUN run command in env variable 576 CFG_CMD_SAVES save S record dump 577 CFG_CMD_SCSI * SCSI Support 578 CFG_CMD_SDRAM * print SDRAM configuration information 579 CFG_CMD_SETGETDCR Support for DCR Register access (4xx only) 580 CFG_CMD_SPI * SPI serial bus support 581 CFG_CMD_USB * USB support 582 CFG_CMD_VFD * VFD support (TRAB) 583 CFG_CMD_BSP * Board SPecific functions 584 CFG_CMD_CDP * Cisco Discover Protocol support 585 ----------------------------------------------- 586 CFG_CMD_ALL all 587 588 CFG_CMD_DFL Default configuration; at the moment 589 this is includes all commands, except 590 the ones marked with "*" in the list 591 above. 592 593 If you don't define CONFIG_COMMANDS it defaults to 594 CFG_CMD_DFL in include/cmd_confdefs.h. A board can 595 override the default settings in the respective 596 include file. 597 598 EXAMPLE: If you want all functions except of network 599 support you can write: 600 601 #define CONFIG_COMMANDS (CFG_CMD_ALL & ~CFG_CMD_NET) 602 603 604 Note: Don't enable the "icache" and "dcache" commands 605 (configuration option CFG_CMD_CACHE) unless you know 606 what you (and your U-Boot users) are doing. Data 607 cache cannot be enabled on systems like the 8xx or 608 8260 (where accesses to the IMMR region must be 609 uncached), and it cannot be disabled on all other 610 systems where we (mis-) use the data cache to hold an 611 initial stack and some data. 612 613 614 XXX - this list needs to get updated! 615 616- Watchdog: 617 CONFIG_WATCHDOG 618 If this variable is defined, it enables watchdog 619 support. There must be support in the platform specific 620 code for a watchdog. For the 8xx and 8260 CPUs, the 621 SIU Watchdog feature is enabled in the SYPCR 622 register. 623 624- U-Boot Version: 625 CONFIG_VERSION_VARIABLE 626 If this variable is defined, an environment variable 627 named "ver" is created by U-Boot showing the U-Boot 628 version as printed by the "version" command. 629 This variable is readonly. 630 631- Real-Time Clock: 632 633 When CFG_CMD_DATE is selected, the type of the RTC 634 has to be selected, too. Define exactly one of the 635 following options: 636 637 CONFIG_RTC_MPC8xx - use internal RTC of MPC8xx 638 CONFIG_RTC_PCF8563 - use Philips PCF8563 RTC 639 CONFIG_RTC_MC146818 - use MC146818 RTC 640 CONFIG_RTC_DS1307 - use Maxim, Inc. DS1307 RTC 641 CONFIG_RTC_DS1337 - use Maxim, Inc. DS1337 RTC 642 CONFIG_RTC_DS1338 - use Maxim, Inc. DS1338 RTC 643 CONFIG_RTC_DS164x - use Dallas DS164x RTC 644 645 Note that if the RTC uses I2C, then the I2C interface 646 must also be configured. See I2C Support, below. 647 648- Timestamp Support: 649 650 When CONFIG_TIMESTAMP is selected, the timestamp 651 (date and time) of an image is printed by image 652 commands like bootm or iminfo. This option is 653 automatically enabled when you select CFG_CMD_DATE . 654 655- Partition Support: 656 CONFIG_MAC_PARTITION and/or CONFIG_DOS_PARTITION 657 and/or CONFIG_ISO_PARTITION 658 659 If IDE or SCSI support is enabled (CFG_CMD_IDE or 660 CFG_CMD_SCSI) you must configure support for at least 661 one partition type as well. 662 663- IDE Reset method: 664 CONFIG_IDE_RESET_ROUTINE - this is defined in several 665 board configurations files but used nowhere! 666 667 CONFIG_IDE_RESET - is this is defined, IDE Reset will 668 be performed by calling the function 669 ide_set_reset(int reset) 670 which has to be defined in a board specific file 671 672- ATAPI Support: 673 CONFIG_ATAPI 674 675 Set this to enable ATAPI support. 676 677- LBA48 Support 678 CONFIG_LBA48 679 680 Set this to enable support for disks larger than 137GB 681 Also look at CFG_64BIT_LBA ,CFG_64BIT_VSPRINTF and CFG_64BIT_STRTOUL 682 Whithout these , LBA48 support uses 32bit variables and will 'only' 683 support disks up to 2.1TB. 684 685 CFG_64BIT_LBA: 686 When enabled, makes the IDE subsystem use 64bit sector addresses. 687 Default is 32bit. 688 689- SCSI Support: 690 At the moment only there is only support for the 691 SYM53C8XX SCSI controller; define 692 CONFIG_SCSI_SYM53C8XX to enable it. 693 694 CFG_SCSI_MAX_LUN [8], CFG_SCSI_MAX_SCSI_ID [7] and 695 CFG_SCSI_MAX_DEVICE [CFG_SCSI_MAX_SCSI_ID * 696 CFG_SCSI_MAX_LUN] can be adjusted to define the 697 maximum numbers of LUNs, SCSI ID's and target 698 devices. 699 CFG_SCSI_SYM53C8XX_CCF to fix clock timing (80Mhz) 700 701- NETWORK Support (PCI): 702 CONFIG_E1000 703 Support for Intel 8254x gigabit chips. 704 705 CONFIG_EEPRO100 706 Support for Intel 82557/82559/82559ER chips. 707 Optional CONFIG_EEPRO100_SROM_WRITE enables eeprom 708 write routine for first time initialisation. 709 710 CONFIG_TULIP 711 Support for Digital 2114x chips. 712 Optional CONFIG_TULIP_SELECT_MEDIA for board specific 713 modem chip initialisation (KS8761/QS6611). 714 715 CONFIG_NATSEMI 716 Support for National dp83815 chips. 717 718 CONFIG_NS8382X 719 Support for National dp8382[01] gigabit chips. 720 721- NETWORK Support (other): 722 723 CONFIG_DRIVER_LAN91C96 724 Support for SMSC's LAN91C96 chips. 725 726 CONFIG_LAN91C96_BASE 727 Define this to hold the physical address 728 of the LAN91C96's I/O space 729 730 CONFIG_LAN91C96_USE_32_BIT 731 Define this to enable 32 bit addressing 732 733- USB Support: 734 At the moment only the UHCI host controller is 735 supported (PIP405, MIP405, MPC5200); define 736 CONFIG_USB_UHCI to enable it. 737 define CONFIG_USB_KEYBOARD to enable the USB Keyboard 738 end define CONFIG_USB_STORAGE to enable the USB 739 storage devices. 740 Note: 741 Supported are USB Keyboards and USB Floppy drives 742 (TEAC FD-05PUB). 743 MPC5200 USB requires additional defines: 744 CONFIG_USB_CLOCK 745 for 528 MHz Clock: 0x0001bbbb 746 CONFIG_USB_CONFIG 747 for differential drivers: 0x00001000 748 for single ended drivers: 0x00005000 749 750 751- MMC Support: 752 The MMC controller on the Intel PXA is supported. To 753 enable this define CONFIG_MMC. The MMC can be 754 accessed from the boot prompt by mapping the device 755 to physical memory similar to flash. Command line is 756 enabled with CFG_CMD_MMC. The MMC driver also works with 757 the FAT fs. This is enabled with CFG_CMD_FAT. 758 759- Keyboard Support: 760 CONFIG_ISA_KEYBOARD 761 762 Define this to enable standard (PC-Style) keyboard 763 support 764 765 CONFIG_I8042_KBD 766 Standard PC keyboard driver with US (is default) and 767 GERMAN key layout (switch via environment 'keymap=de') support. 768 Export function i8042_kbd_init, i8042_tstc and i8042_getc 769 for cfb_console. Supports cursor blinking. 770 771- Video support: 772 CONFIG_VIDEO 773 774 Define this to enable video support (for output to 775 video). 776 777 CONFIG_VIDEO_CT69000 778 779 Enable Chips & Technologies 69000 Video chip 780 781 CONFIG_VIDEO_SMI_LYNXEM 782 Enable Silicon Motion SMI 712/710/810 Video chip. The 783 video output is selected via environment 'videoout' 784 (1 = LCD and 2 = CRT). If videoout is undefined, CRT is 785 assumed. 786 787 For the CT69000 and SMI_LYNXEM drivers, videomode is 788 selected via environment 'videomode'. Two diferent ways 789 are possible: 790 - "videomode=num" 'num' is a standard LiLo mode numbers. 791 Following standard modes are supported (* is default): 792 793 Colors 640x480 800x600 1024x768 1152x864 1280x1024 794 -------------+--------------------------------------------- 795 8 bits | 0x301* 0x303 0x305 0x161 0x307 796 15 bits | 0x310 0x313 0x316 0x162 0x319 797 16 bits | 0x311 0x314 0x317 0x163 0x31A 798 24 bits | 0x312 0x315 0x318 ? 0x31B 799 -------------+--------------------------------------------- 800 (i.e. setenv videomode 317; saveenv; reset;) 801 802 - "videomode=bootargs" all the video parameters are parsed 803 from the bootargs. (See drivers/videomodes.c) 804 805 806 CONFIG_VIDEO_SED13806 807 Enable Epson SED13806 driver. This driver supports 8bpp 808 and 16bpp modes defined by CONFIG_VIDEO_SED13806_8BPP 809 or CONFIG_VIDEO_SED13806_16BPP 810 811- Keyboard Support: 812 CONFIG_KEYBOARD 813 814 Define this to enable a custom keyboard support. 815 This simply calls drv_keyboard_init() which must be 816 defined in your board-specific files. 817 The only board using this so far is RBC823. 818 819- LCD Support: CONFIG_LCD 820 821 Define this to enable LCD support (for output to LCD 822 display); also select one of the supported displays 823 by defining one of these: 824 825 CONFIG_NEC_NL6448AC33: 826 827 NEC NL6448AC33-18. Active, color, single scan. 828 829 CONFIG_NEC_NL6448BC20 830 831 NEC NL6448BC20-08. 6.5", 640x480. 832 Active, color, single scan. 833 834 CONFIG_NEC_NL6448BC33_54 835 836 NEC NL6448BC33-54. 10.4", 640x480. 837 Active, color, single scan. 838 839 CONFIG_SHARP_16x9 840 841 Sharp 320x240. Active, color, single scan. 842 It isn't 16x9, and I am not sure what it is. 843 844 CONFIG_SHARP_LQ64D341 845 846 Sharp LQ64D341 display, 640x480. 847 Active, color, single scan. 848 849 CONFIG_HLD1045 850 851 HLD1045 display, 640x480. 852 Active, color, single scan. 853 854 CONFIG_OPTREX_BW 855 856 Optrex CBL50840-2 NF-FW 99 22 M5 857 or 858 Hitachi LMG6912RPFC-00T 859 or 860 Hitachi SP14Q002 861 862 320x240. Black & white. 863 864 Normally display is black on white background; define 865 CFG_WHITE_ON_BLACK to get it inverted. 866 867- Splash Screen Support: CONFIG_SPLASH_SCREEN 868 869 If this option is set, the environment is checked for 870 a variable "splashimage". If found, the usual display 871 of logo, copyright and system information on the LCD 872 is supressed and the BMP image at the address 873 specified in "splashimage" is loaded instead. The 874 console is redirected to the "nulldev", too. This 875 allows for a "silent" boot where a splash screen is 876 loaded very quickly after power-on. 877 878- Compression support: 879 CONFIG_BZIP2 880 881 If this option is set, support for bzip2 compressed 882 images is included. If not, only uncompressed and gzip 883 compressed images are supported. 884 885 NOTE: the bzip2 algorithm requires a lot of RAM, so 886 the malloc area (as defined by CFG_MALLOC_LEN) should 887 be at least 4MB. 888 889- Ethernet address: 890 CONFIG_ETHADDR 891 CONFIG_ETH2ADDR 892 CONFIG_ETH3ADDR 893 894 Define a default value for ethernet address to use 895 for the respective ethernet interface, in case this 896 is not determined automatically. 897 898- IP address: 899 CONFIG_IPADDR 900 901 Define a default value for the IP address to use for 902 the default ethernet interface, in case this is not 903 determined through e.g. bootp. 904 905- Server IP address: 906 CONFIG_SERVERIP 907 908 Defines a default value for theIP address of a TFTP 909 server to contact when using the "tftboot" command. 910 911- BOOTP Recovery Mode: 912 CONFIG_BOOTP_RANDOM_DELAY 913 914 If you have many targets in a network that try to 915 boot using BOOTP, you may want to avoid that all 916 systems send out BOOTP requests at precisely the same 917 moment (which would happen for instance at recovery 918 from a power failure, when all systems will try to 919 boot, thus flooding the BOOTP server. Defining 920 CONFIG_BOOTP_RANDOM_DELAY causes a random delay to be 921 inserted before sending out BOOTP requests. The 922 following delays are insterted then: 923 924 1st BOOTP request: delay 0 ... 1 sec 925 2nd BOOTP request: delay 0 ... 2 sec 926 3rd BOOTP request: delay 0 ... 4 sec 927 4th and following 928 BOOTP requests: delay 0 ... 8 sec 929 930- DHCP Advanced Options: 931 CONFIG_BOOTP_MASK 932 933 You can fine tune the DHCP functionality by adding 934 these flags to the CONFIG_BOOTP_MASK define: 935 936 CONFIG_BOOTP_DNS2 - If a DHCP client requests the DNS 937 serverip from a DHCP server, it is possible that more 938 than one DNS serverip is offered to the client. 939 If CONFIG_BOOTP_DNS2 is enabled, the secondary DNS 940 serverip will be stored in the additional environment 941 variable "dnsip2". The first DNS serverip is always 942 stored in the variable "dnsip", when CONFIG_BOOTP_DNS 943 is added to the CONFIG_BOOTP_MASK. 944 945 CONFIG_BOOTP_SEND_HOSTNAME - Some DHCP servers are capable 946 to do a dynamic update of a DNS server. To do this, they 947 need the hostname of the DHCP requester. 948 If CONFIG_BOOP_SEND_HOSTNAME is added to the 949 CONFIG_BOOTP_MASK, the content of the "hostname" 950 environment variable is passed as option 12 to 951 the DHCP server. 952 953 - CDP Options: 954 CONFIG_CDP_DEVICE_ID 955 956 The device id used in CDP trigger frames. 957 958 CONFIG_CDP_DEVICE_ID_PREFIX 959 960 A two character string which is prefixed to the MAC address 961 of the device. 962 963 CONFIG_CDP_PORT_ID 964 965 A printf format string which contains the ascii name of 966 the port. Normally is set to "eth%d" which sets 967 eth0 for the first ethernet, eth1 for the second etc. 968 969 CONFIG_CDP_CAPABILITIES 970 971 A 32bit integer which indicates the device capabilities; 972 0x00000010 for a normal host which does not forwards. 973 974 CONFIG_CDP_VERSION 975 976 An ascii string containing the version of the software. 977 978 CONFIG_CDP_PLATFORM 979 980 An ascii string containing the name of the platform. 981 982 CONFIG_CDP_TRIGGER 983 984 A 32bit integer sent on the trigger. 985 986 CONFIG_CDP_POWER_CONSUMPTION 987 988 A 16bit integer containing the power consumption of the 989 device in .1 of milliwatts. 990 991 CONFIG_CDP_APPLIANCE_VLAN_TYPE 992 993 A byte containing the id of the VLAN. 994 995- Status LED: CONFIG_STATUS_LED 996 997 Several configurations allow to display the current 998 status using a LED. For instance, the LED will blink 999 fast while running U-Boot code, stop blinking as 1000 soon as a reply to a BOOTP request was received, and 1001 start blinking slow once the Linux kernel is running 1002 (supported by a status LED driver in the Linux 1003 kernel). Defining CONFIG_STATUS_LED enables this 1004 feature in U-Boot. 1005 1006- CAN Support: CONFIG_CAN_DRIVER 1007 1008 Defining CONFIG_CAN_DRIVER enables CAN driver support 1009 on those systems that support this (optional) 1010 feature, like the TQM8xxL modules. 1011 1012- I2C Support: CONFIG_HARD_I2C | CONFIG_SOFT_I2C 1013 1014 These enable I2C serial bus commands. Defining either of 1015 (but not both of) CONFIG_HARD_I2C or CONFIG_SOFT_I2C will 1016 include the appropriate I2C driver for the selected cpu. 1017 1018 This will allow you to use i2c commands at the u-boot 1019 command line (as long as you set CFG_CMD_I2C in 1020 CONFIG_COMMANDS) and communicate with i2c based realtime 1021 clock chips. See common/cmd_i2c.c for a description of the 1022 command line interface. 1023 1024 CONFIG_HARD_I2C selects the CPM hardware driver for I2C. 1025 1026 CONFIG_SOFT_I2C configures u-boot to use a software (aka 1027 bit-banging) driver instead of CPM or similar hardware 1028 support for I2C. 1029 1030 There are several other quantities that must also be 1031 defined when you define CONFIG_HARD_I2C or CONFIG_SOFT_I2C. 1032 1033 In both cases you will need to define CFG_I2C_SPEED 1034 to be the frequency (in Hz) at which you wish your i2c bus 1035 to run and CFG_I2C_SLAVE to be the address of this node (ie 1036 the cpu's i2c node address). 1037 1038 Now, the u-boot i2c code for the mpc8xx (cpu/mpc8xx/i2c.c) 1039 sets the cpu up as a master node and so its address should 1040 therefore be cleared to 0 (See, eg, MPC823e User's Manual 1041 p.16-473). So, set CFG_I2C_SLAVE to 0. 1042 1043 That's all that's required for CONFIG_HARD_I2C. 1044 1045 If you use the software i2c interface (CONFIG_SOFT_I2C) 1046 then the following macros need to be defined (examples are 1047 from include/configs/lwmon.h): 1048 1049 I2C_INIT 1050 1051 (Optional). Any commands necessary to enable the I2C 1052 controller or configure ports. 1053 1054 eg: #define I2C_INIT (immr->im_cpm.cp_pbdir |= PB_SCL) 1055 1056 I2C_PORT 1057 1058 (Only for MPC8260 CPU). The I/O port to use (the code 1059 assumes both bits are on the same port). Valid values 1060 are 0..3 for ports A..D. 1061 1062 I2C_ACTIVE 1063 1064 The code necessary to make the I2C data line active 1065 (driven). If the data line is open collector, this 1066 define can be null. 1067 1068 eg: #define I2C_ACTIVE (immr->im_cpm.cp_pbdir |= PB_SDA) 1069 1070 I2C_TRISTATE 1071 1072 The code necessary to make the I2C data line tri-stated 1073 (inactive). If the data line is open collector, this 1074 define can be null. 1075 1076 eg: #define I2C_TRISTATE (immr->im_cpm.cp_pbdir &= ~PB_SDA) 1077 1078 I2C_READ 1079 1080 Code that returns TRUE if the I2C data line is high, 1081 FALSE if it is low. 1082 1083 eg: #define I2C_READ ((immr->im_cpm.cp_pbdat & PB_SDA) != 0) 1084 1085 I2C_SDA(bit) 1086 1087 If <bit> is TRUE, sets the I2C data line high. If it 1088 is FALSE, it clears it (low). 1089 1090 eg: #define I2C_SDA(bit) \ 1091 if(bit) immr->im_cpm.cp_pbdat |= PB_SDA; \ 1092 else immr->im_cpm.cp_pbdat &= ~PB_SDA 1093 1094 I2C_SCL(bit) 1095 1096 If <bit> is TRUE, sets the I2C clock line high. If it 1097 is FALSE, it clears it (low). 1098 1099 eg: #define I2C_SCL(bit) \ 1100 if(bit) immr->im_cpm.cp_pbdat |= PB_SCL; \ 1101 else immr->im_cpm.cp_pbdat &= ~PB_SCL 1102 1103 I2C_DELAY 1104 1105 This delay is invoked four times per clock cycle so this 1106 controls the rate of data transfer. The data rate thus 1107 is 1 / (I2C_DELAY * 4). Often defined to be something 1108 like: 1109 1110 #define I2C_DELAY udelay(2) 1111 1112 CFG_I2C_INIT_BOARD 1113 1114 When a board is reset during an i2c bus transfer 1115 chips might think that the current transfer is still 1116 in progress. On some boards it is possible to access 1117 the i2c SCLK line directly, either by using the 1118 processor pin as a GPIO or by having a second pin 1119 connected to the bus. If this option is defined a 1120 custom i2c_init_board() routine in boards/xxx/board.c 1121 is run early in the boot sequence. 1122 1123- SPI Support: CONFIG_SPI 1124 1125 Enables SPI driver (so far only tested with 1126 SPI EEPROM, also an instance works with Crystal A/D and 1127 D/As on the SACSng board) 1128 1129 CONFIG_SPI_X 1130 1131 Enables extended (16-bit) SPI EEPROM addressing. 1132 (symmetrical to CONFIG_I2C_X) 1133 1134 CONFIG_SOFT_SPI 1135 1136 Enables a software (bit-bang) SPI driver rather than 1137 using hardware support. This is a general purpose 1138 driver that only requires three general I/O port pins 1139 (two outputs, one input) to function. If this is 1140 defined, the board configuration must define several 1141 SPI configuration items (port pins to use, etc). For 1142 an example, see include/configs/sacsng.h. 1143 1144- FPGA Support: CONFIG_FPGA_COUNT 1145 1146 Specify the number of FPGA devices to support. 1147 1148 CONFIG_FPGA 1149 1150 Used to specify the types of FPGA devices. For example, 1151 #define CONFIG_FPGA CFG_XILINX_VIRTEX2 1152 1153 CFG_FPGA_PROG_FEEDBACK 1154 1155 Enable printing of hash marks during FPGA configuration. 1156 1157 CFG_FPGA_CHECK_BUSY 1158 1159 Enable checks on FPGA configuration interface busy 1160 status by the configuration function. This option 1161 will require a board or device specific function to 1162 be written. 1163 1164 CONFIG_FPGA_DELAY 1165 1166 If defined, a function that provides delays in the FPGA 1167 configuration driver. 1168 1169 CFG_FPGA_CHECK_CTRLC 1170 Allow Control-C to interrupt FPGA configuration 1171 1172 CFG_FPGA_CHECK_ERROR 1173 1174 Check for configuration errors during FPGA bitfile 1175 loading. For example, abort during Virtex II 1176 configuration if the INIT_B line goes low (which 1177 indicated a CRC error). 1178 1179 CFG_FPGA_WAIT_INIT 1180 1181 Maximum time to wait for the INIT_B line to deassert 1182 after PROB_B has been deasserted during a Virtex II 1183 FPGA configuration sequence. The default time is 500 1184 mS. 1185 1186 CFG_FPGA_WAIT_BUSY 1187 1188 Maximum time to wait for BUSY to deassert during 1189 Virtex II FPGA configuration. The default is 5 mS. 1190 1191 CFG_FPGA_WAIT_CONFIG 1192 1193 Time to wait after FPGA configuration. The default is 1194 200 mS. 1195 1196- Configuration Management: 1197 CONFIG_IDENT_STRING 1198 1199 If defined, this string will be added to the U-Boot 1200 version information (U_BOOT_VERSION) 1201 1202- Vendor Parameter Protection: 1203 1204 U-Boot considers the values of the environment 1205 variables "serial#" (Board Serial Number) and 1206 "ethaddr" (Ethernet Address) to be parameters that 1207 are set once by the board vendor / manufacturer, and 1208 protects these variables from casual modification by 1209 the user. Once set, these variables are read-only, 1210 and write or delete attempts are rejected. You can 1211 change this behviour: 1212 1213 If CONFIG_ENV_OVERWRITE is #defined in your config 1214 file, the write protection for vendor parameters is 1215 completely disabled. Anybody can change or delete 1216 these parameters. 1217 1218 Alternatively, if you #define _both_ CONFIG_ETHADDR 1219 _and_ CONFIG_OVERWRITE_ETHADDR_ONCE, a default 1220 ethernet address is installed in the environment, 1221 which can be changed exactly ONCE by the user. [The 1222 serial# is unaffected by this, i. e. it remains 1223 read-only.] 1224 1225- Protected RAM: 1226 CONFIG_PRAM 1227 1228 Define this variable to enable the reservation of 1229 "protected RAM", i. e. RAM which is not overwritten 1230 by U-Boot. Define CONFIG_PRAM to hold the number of 1231 kB you want to reserve for pRAM. You can overwrite 1232 this default value by defining an environment 1233 variable "pram" to the number of kB you want to 1234 reserve. Note that the board info structure will 1235 still show the full amount of RAM. If pRAM is 1236 reserved, a new environment variable "mem" will 1237 automatically be defined to hold the amount of 1238 remaining RAM in a form that can be passed as boot 1239 argument to Linux, for instance like that: 1240 1241 setenv bootargs ... mem=\$(mem) 1242 saveenv 1243 1244 This way you can tell Linux not to use this memory, 1245 either, which results in a memory region that will 1246 not be affected by reboots. 1247 1248 *WARNING* If your board configuration uses automatic 1249 detection of the RAM size, you must make sure that 1250 this memory test is non-destructive. So far, the 1251 following board configurations are known to be 1252 "pRAM-clean": 1253 1254 ETX094, IVMS8, IVML24, SPD8xx, TQM8xxL, 1255 HERMES, IP860, RPXlite, LWMON, LANTEC, 1256 PCU_E, FLAGADM, TQM8260 1257 1258- Error Recovery: 1259 CONFIG_PANIC_HANG 1260 1261 Define this variable to stop the system in case of a 1262 fatal error, so that you have to reset it manually. 1263 This is probably NOT a good idea for an embedded 1264 system where you want to system to reboot 1265 automatically as fast as possible, but it may be 1266 useful during development since you can try to debug 1267 the conditions that lead to the situation. 1268 1269 CONFIG_NET_RETRY_COUNT 1270 1271 This variable defines the number of retries for 1272 network operations like ARP, RARP, TFTP, or BOOTP 1273 before giving up the operation. If not defined, a 1274 default value of 5 is used. 1275 1276- Command Interpreter: 1277 CFG_AUTO_COMPLETE 1278 1279 Enable auto completion of commands using TAB. 1280 1281 CFG_HUSH_PARSER 1282 1283 Define this variable to enable the "hush" shell (from 1284 Busybox) as command line interpreter, thus enabling 1285 powerful command line syntax like 1286 if...then...else...fi conditionals or `&&' and '||' 1287 constructs ("shell scripts"). 1288 1289 If undefined, you get the old, much simpler behaviour 1290 with a somewhat smaller memory footprint. 1291 1292 1293 CFG_PROMPT_HUSH_PS2 1294 1295 This defines the secondary prompt string, which is 1296 printed when the command interpreter needs more input 1297 to complete a command. Usually "> ". 1298 1299 Note: 1300 1301 In the current implementation, the local variables 1302 space and global environment variables space are 1303 separated. Local variables are those you define by 1304 simply typing `name=value'. To access a local 1305 variable later on, you have write `$name' or 1306 `${name}'; to execute the contents of a variable 1307 directly type `$name' at the command prompt. 1308 1309 Global environment variables are those you use 1310 setenv/printenv to work with. To run a command stored 1311 in such a variable, you need to use the run command, 1312 and you must not use the '$' sign to access them. 1313 1314 To store commands and special characters in a 1315 variable, please use double quotation marks 1316 surrounding the whole text of the variable, instead 1317 of the backslashes before semicolons and special 1318 symbols. 1319 1320- Default Environment: 1321 CONFIG_EXTRA_ENV_SETTINGS 1322 1323 Define this to contain any number of null terminated 1324 strings (variable = value pairs) that will be part of 1325 the default environment compiled into the boot image. 1326 1327 For example, place something like this in your 1328 board's config file: 1329 1330 #define CONFIG_EXTRA_ENV_SETTINGS \ 1331 "myvar1=value1\0" \ 1332 "myvar2=value2\0" 1333 1334 Warning: This method is based on knowledge about the 1335 internal format how the environment is stored by the 1336 U-Boot code. This is NOT an official, exported 1337 interface! Although it is unlikely that this format 1338 will change soon, there is no guarantee either. 1339 You better know what you are doing here. 1340 1341 Note: overly (ab)use of the default environment is 1342 discouraged. Make sure to check other ways to preset 1343 the environment like the autoscript function or the 1344 boot command first. 1345 1346- DataFlash Support: 1347 CONFIG_HAS_DATAFLASH 1348 1349 Defining this option enables DataFlash features and 1350 allows to read/write in Dataflash via the standard 1351 commands cp, md... 1352 1353- SystemACE Support: 1354 CONFIG_SYSTEMACE 1355 1356 Adding this option adds support for Xilinx SystemACE 1357 chips attached via some sort of local bus. The address 1358 of the chip must alsh be defined in the 1359 CFG_SYSTEMACE_BASE macro. For example: 1360 1361 #define CONFIG_SYSTEMACE 1362 #define CFG_SYSTEMACE_BASE 0xf0000000 1363 1364 When SystemACE support is added, the "ace" device type 1365 becomes available to the fat commands, i.e. fatls. 1366 1367- Show boot progress: 1368 CONFIG_SHOW_BOOT_PROGRESS 1369 1370 Defining this option allows to add some board- 1371 specific code (calling a user-provided function 1372 "show_boot_progress(int)") that enables you to show 1373 the system's boot progress on some display (for 1374 example, some LED's) on your board. At the moment, 1375 the following checkpoints are implemented: 1376 1377 Arg Where When 1378 1 common/cmd_bootm.c before attempting to boot an image 1379 -1 common/cmd_bootm.c Image header has bad magic number 1380 2 common/cmd_bootm.c Image header has correct magic number 1381 -2 common/cmd_bootm.c Image header has bad checksum 1382 3 common/cmd_bootm.c Image header has correct checksum 1383 -3 common/cmd_bootm.c Image data has bad checksum 1384 4 common/cmd_bootm.c Image data has correct checksum 1385 -4 common/cmd_bootm.c Image is for unsupported architecture 1386 5 common/cmd_bootm.c Architecture check OK 1387 -5 common/cmd_bootm.c Wrong Image Type (not kernel, multi, standalone) 1388 6 common/cmd_bootm.c Image Type check OK 1389 -6 common/cmd_bootm.c gunzip uncompression error 1390 -7 common/cmd_bootm.c Unimplemented compression type 1391 7 common/cmd_bootm.c Uncompression OK 1392 -8 common/cmd_bootm.c Wrong Image Type (not kernel, multi, standalone) 1393 8 common/cmd_bootm.c Image Type check OK 1394 -9 common/cmd_bootm.c Unsupported OS (not Linux, BSD, VxWorks, QNX) 1395 9 common/cmd_bootm.c Start initial ramdisk verification 1396 -10 common/cmd_bootm.c Ramdisk header has bad magic number 1397 -11 common/cmd_bootm.c Ramdisk header has bad checksum 1398 10 common/cmd_bootm.c Ramdisk header is OK 1399 -12 common/cmd_bootm.c Ramdisk data has bad checksum 1400 11 common/cmd_bootm.c Ramdisk data has correct checksum 1401 12 common/cmd_bootm.c Ramdisk verification complete, start loading 1402 -13 common/cmd_bootm.c Wrong Image Type (not PPC Linux Ramdisk) 1403 13 common/cmd_bootm.c Start multifile image verification 1404 14 common/cmd_bootm.c No initial ramdisk, no multifile, continue. 1405 15 common/cmd_bootm.c All preparation done, transferring control to OS 1406 1407 -30 lib_ppc/board.c Fatal error, hang the system 1408 -31 post/post.c POST test failed, detected by post_output_backlog() 1409 -32 post/post.c POST test failed, detected by post_run_single() 1410 1411 -1 common/cmd_doc.c Bad usage of "doc" command 1412 -1 common/cmd_doc.c No boot device 1413 -1 common/cmd_doc.c Unknown Chip ID on boot device 1414 -1 common/cmd_doc.c Read Error on boot device 1415 -1 common/cmd_doc.c Image header has bad magic number 1416 1417 -1 common/cmd_ide.c Bad usage of "ide" command 1418 -1 common/cmd_ide.c No boot device 1419 -1 common/cmd_ide.c Unknown boot device 1420 -1 common/cmd_ide.c Unknown partition table 1421 -1 common/cmd_ide.c Invalid partition type 1422 -1 common/cmd_ide.c Read Error on boot device 1423 -1 common/cmd_ide.c Image header has bad magic number 1424 1425 -1 common/cmd_nand.c Bad usage of "nand" command 1426 -1 common/cmd_nand.c No boot device 1427 -1 common/cmd_nand.c Unknown Chip ID on boot device 1428 -1 common/cmd_nand.c Read Error on boot device 1429 -1 common/cmd_nand.c Image header has bad magic number 1430 1431 -1 common/env_common.c Environment has a bad CRC, using default 1432 1433 1434Modem Support: 1435-------------- 1436 1437[so far only for SMDK2400 and TRAB boards] 1438 1439- Modem support endable: 1440 CONFIG_MODEM_SUPPORT 1441 1442- RTS/CTS Flow control enable: 1443 CONFIG_HWFLOW 1444 1445- Modem debug support: 1446 CONFIG_MODEM_SUPPORT_DEBUG 1447 1448 Enables debugging stuff (char screen[1024], dbg()) 1449 for modem support. Useful only with BDI2000. 1450 1451- Interrupt support (PPC): 1452 1453 There are common interrupt_init() and timer_interrupt() 1454 for all PPC archs. interrupt_init() calls interrupt_init_cpu() 1455 for cpu specific initialization. interrupt_init_cpu() 1456 should set decrementer_count to appropriate value. If 1457 cpu resets decrementer automatically after interrupt 1458 (ppc4xx) it should set decrementer_count to zero. 1459 timer_interrupt() calls timer_interrupt_cpu() for cpu 1460 specific handling. If board has watchdog / status_led 1461 / other_activity_monitor it works automatically from 1462 general timer_interrupt(). 1463 1464- General: 1465 1466 In the target system modem support is enabled when a 1467 specific key (key combination) is pressed during 1468 power-on. Otherwise U-Boot will boot normally 1469 (autoboot). The key_pressed() fuction is called from 1470 board_init(). Currently key_pressed() is a dummy 1471 function, returning 1 and thus enabling modem 1472 initialization. 1473 1474 If there are no modem init strings in the 1475 environment, U-Boot proceed to autoboot; the 1476 previous output (banner, info printfs) will be 1477 supressed, though. 1478 1479 See also: doc/README.Modem 1480 1481 1482Configuration Settings: 1483----------------------- 1484 1485- CFG_LONGHELP: Defined when you want long help messages included; 1486 undefine this when you're short of memory. 1487 1488- CFG_PROMPT: This is what U-Boot prints on the console to 1489 prompt for user input. 1490 1491- CFG_CBSIZE: Buffer size for input from the Console 1492 1493- CFG_PBSIZE: Buffer size for Console output 1494 1495- CFG_MAXARGS: max. Number of arguments accepted for monitor commands 1496 1497- CFG_BARGSIZE: Buffer size for Boot Arguments which are passed to 1498 the application (usually a Linux kernel) when it is 1499 booted 1500 1501- CFG_BAUDRATE_TABLE: 1502 List of legal baudrate settings for this board. 1503 1504- CFG_CONSOLE_INFO_QUIET 1505 Suppress display of console information at boot. 1506 1507- CFG_CONSOLE_IS_IN_ENV 1508 If the board specific function 1509 extern int overwrite_console (void); 1510 returns 1, the stdin, stderr and stdout are switched to the 1511 serial port, else the settings in the environment are used. 1512 1513- CFG_CONSOLE_OVERWRITE_ROUTINE 1514 Enable the call to overwrite_console(). 1515 1516- CFG_CONSOLE_ENV_OVERWRITE 1517 Enable overwrite of previous console environment settings. 1518 1519- CFG_MEMTEST_START, CFG_MEMTEST_END: 1520 Begin and End addresses of the area used by the 1521 simple memory test. 1522 1523- CFG_ALT_MEMTEST: 1524 Enable an alternate, more extensive memory test. 1525 1526- CFG_MEMTEST_SCRATCH: 1527 Scratch address used by the alternate memory test 1528 You only need to set this if address zero isn't writeable 1529 1530- CFG_TFTP_LOADADDR: 1531 Default load address for network file downloads 1532 1533- CFG_LOADS_BAUD_CHANGE: 1534 Enable temporary baudrate change while serial download 1535 1536- CFG_SDRAM_BASE: 1537 Physical start address of SDRAM. _Must_ be 0 here. 1538 1539- CFG_MBIO_BASE: 1540 Physical start address of Motherboard I/O (if using a 1541 Cogent motherboard) 1542 1543- CFG_FLASH_BASE: 1544 Physical start address of Flash memory. 1545 1546- CFG_MONITOR_BASE: 1547 Physical start address of boot monitor code (set by 1548 make config files to be same as the text base address 1549 (TEXT_BASE) used when linking) - same as 1550 CFG_FLASH_BASE when booting from flash. 1551 1552- CFG_MONITOR_LEN: 1553 Size of memory reserved for monitor code, used to 1554 determine _at_compile_time_ (!) if the environment is 1555 embedded within the U-Boot image, or in a separate 1556 flash sector. 1557 1558- CFG_MALLOC_LEN: 1559 Size of DRAM reserved for malloc() use. 1560 1561- CFG_BOOTMAPSZ: 1562 Maximum size of memory mapped by the startup code of 1563 the Linux kernel; all data that must be processed by 1564 the Linux kernel (bd_info, boot arguments, eventually 1565 initrd image) must be put below this limit. 1566 1567- CFG_MAX_FLASH_BANKS: 1568 Max number of Flash memory banks 1569 1570- CFG_MAX_FLASH_SECT: 1571 Max number of sectors on a Flash chip 1572 1573- CFG_FLASH_ERASE_TOUT: 1574 Timeout for Flash erase operations (in ms) 1575 1576- CFG_FLASH_WRITE_TOUT: 1577 Timeout for Flash write operations (in ms) 1578 1579- CFG_FLASH_LOCK_TOUT 1580 Timeout for Flash set sector lock bit operation (in ms) 1581 1582- CFG_FLASH_UNLOCK_TOUT 1583 Timeout for Flash clear lock bits operation (in ms) 1584 1585- CFG_FLASH_PROTECTION 1586 If defined, hardware flash sectors protection is used 1587 instead of U-Boot software protection. 1588 1589- CFG_DIRECT_FLASH_TFTP: 1590 1591 Enable TFTP transfers directly to flash memory; 1592 without this option such a download has to be 1593 performed in two steps: (1) download to RAM, and (2) 1594 copy from RAM to flash. 1595 1596 The two-step approach is usually more reliable, since 1597 you can check if the download worked before you erase 1598 the flash, but in some situations (when sytem RAM is 1599 too limited to allow for a tempory copy of the 1600 downloaded image) this option may be very useful. 1601 1602- CFG_FLASH_CFI: 1603 Define if the flash driver uses extra elements in the 1604 common flash structure for storing flash geometry. 1605 1606- CFG_FLASH_CFI_DRIVER 1607 This option also enables the building of the cfi_flash driver 1608 in the drivers directory 1609 1610- CFG_RX_ETH_BUFFER: 1611 Defines the number of ethernet receive buffers. On some 1612 ethernet controllers it is recommended to set this value 1613 to 8 or even higher (EEPRO100 or 405 EMAC), since all 1614 buffers can be full shortly after enabling the interface 1615 on high ethernet traffic. 1616 Defaults to 4 if not defined. 1617 1618The following definitions that deal with the placement and management 1619of environment data (variable area); in general, we support the 1620following configurations: 1621 1622- CFG_ENV_IS_IN_FLASH: 1623 1624 Define this if the environment is in flash memory. 1625 1626 a) The environment occupies one whole flash sector, which is 1627 "embedded" in the text segment with the U-Boot code. This 1628 happens usually with "bottom boot sector" or "top boot 1629 sector" type flash chips, which have several smaller 1630 sectors at the start or the end. For instance, such a 1631 layout can have sector sizes of 8, 2x4, 16, Nx32 kB. In 1632 such a case you would place the environment in one of the 1633 4 kB sectors - with U-Boot code before and after it. With 1634 "top boot sector" type flash chips, you would put the 1635 environment in one of the last sectors, leaving a gap 1636 between U-Boot and the environment. 1637 1638 - CFG_ENV_OFFSET: 1639 1640 Offset of environment data (variable area) to the 1641 beginning of flash memory; for instance, with bottom boot 1642 type flash chips the second sector can be used: the offset 1643 for this sector is given here. 1644 1645 CFG_ENV_OFFSET is used relative to CFG_FLASH_BASE. 1646 1647 - CFG_ENV_ADDR: 1648 1649 This is just another way to specify the start address of 1650 the flash sector containing the environment (instead of 1651 CFG_ENV_OFFSET). 1652 1653 - CFG_ENV_SECT_SIZE: 1654 1655 Size of the sector containing the environment. 1656 1657 1658 b) Sometimes flash chips have few, equal sized, BIG sectors. 1659 In such a case you don't want to spend a whole sector for 1660 the environment. 1661 1662 - CFG_ENV_SIZE: 1663 1664 If you use this in combination with CFG_ENV_IS_IN_FLASH 1665 and CFG_ENV_SECT_SIZE, you can specify to use only a part 1666 of this flash sector for the environment. This saves 1667 memory for the RAM copy of the environment. 1668 1669 It may also save flash memory if you decide to use this 1670 when your environment is "embedded" within U-Boot code, 1671 since then the remainder of the flash sector could be used 1672 for U-Boot code. It should be pointed out that this is 1673 STRONGLY DISCOURAGED from a robustness point of view: 1674 updating the environment in flash makes it always 1675 necessary to erase the WHOLE sector. If something goes 1676 wrong before the contents has been restored from a copy in 1677 RAM, your target system will be dead. 1678 1679 - CFG_ENV_ADDR_REDUND 1680 CFG_ENV_SIZE_REDUND 1681 1682 These settings describe a second storage area used to hold 1683 a redundand copy of the environment data, so that there is 1684 a valid backup copy in case there is a power failure during 1685 a "saveenv" operation. 1686 1687BE CAREFUL! Any changes to the flash layout, and some changes to the 1688source code will make it necessary to adapt <board>/u-boot.lds* 1689accordingly! 1690 1691 1692- CFG_ENV_IS_IN_NVRAM: 1693 1694 Define this if you have some non-volatile memory device 1695 (NVRAM, battery buffered SRAM) which you want to use for the 1696 environment. 1697 1698 - CFG_ENV_ADDR: 1699 - CFG_ENV_SIZE: 1700 1701 These two #defines are used to determin the memory area you 1702 want to use for environment. It is assumed that this memory 1703 can just be read and written to, without any special 1704 provision. 1705 1706BE CAREFUL! The first access to the environment happens quite early 1707in U-Boot initalization (when we try to get the setting of for the 1708console baudrate). You *MUST* have mappend your NVRAM area then, or 1709U-Boot will hang. 1710 1711Please note that even with NVRAM we still use a copy of the 1712environment in RAM: we could work on NVRAM directly, but we want to 1713keep settings there always unmodified except somebody uses "saveenv" 1714to save the current settings. 1715 1716 1717- CFG_ENV_IS_IN_EEPROM: 1718 1719 Use this if you have an EEPROM or similar serial access 1720 device and a driver for it. 1721 1722 - CFG_ENV_OFFSET: 1723 - CFG_ENV_SIZE: 1724 1725 These two #defines specify the offset and size of the 1726 environment area within the total memory of your EEPROM. 1727 1728 - CFG_I2C_EEPROM_ADDR: 1729 If defined, specified the chip address of the EEPROM device. 1730 The default address is zero. 1731 1732 - CFG_EEPROM_PAGE_WRITE_BITS: 1733 If defined, the number of bits used to address bytes in a 1734 single page in the EEPROM device. A 64 byte page, for example 1735 would require six bits. 1736 1737 - CFG_EEPROM_PAGE_WRITE_DELAY_MS: 1738 If defined, the number of milliseconds to delay between 1739 page writes. The default is zero milliseconds. 1740 1741 - CFG_I2C_EEPROM_ADDR_LEN: 1742 The length in bytes of the EEPROM memory array address. Note 1743 that this is NOT the chip address length! 1744 1745 - CFG_EEPROM_SIZE: 1746 The size in bytes of the EEPROM device. 1747 1748 1749- CFG_ENV_IS_IN_DATAFLASH: 1750 1751 Define this if you have a DataFlash memory device which you 1752 want to use for the environment. 1753 1754 - CFG_ENV_OFFSET: 1755 - CFG_ENV_ADDR: 1756 - CFG_ENV_SIZE: 1757 1758 These three #defines specify the offset and size of the 1759 environment area within the total memory of your DataFlash placed 1760 at the specified address. 1761 1762 1763- CFG_SPI_INIT_OFFSET 1764 1765 Defines offset to the initial SPI buffer area in DPRAM. The 1766 area is used at an early stage (ROM part) if the environment 1767 is configured to reside in the SPI EEPROM: We need a 520 byte 1768 scratch DPRAM area. It is used between the two initialization 1769 calls (spi_init_f() and spi_init_r()). A value of 0xB00 seems 1770 to be a good choice since it makes it far enough from the 1771 start of the data area as well as from the stack pointer. 1772 1773Please note that the environment is read-only as long as the monitor 1774has been relocated to RAM and a RAM copy of the environment has been 1775created; also, when using EEPROM you will have to use getenv_r() 1776until then to read environment variables. 1777 1778The environment is protected by a CRC32 checksum. Before the monitor 1779is relocated into RAM, as a result of a bad CRC you will be working 1780with the compiled-in default environment - *silently*!!! [This is 1781necessary, because the first environment variable we need is the 1782"baudrate" setting for the console - if we have a bad CRC, we don't 1783have any device yet where we could complain.] 1784 1785Note: once the monitor has been relocated, then it will complain if 1786the default environment is used; a new CRC is computed as soon as you 1787use the "saveenv" command to store a valid environment. 1788 1789- CFG_FAULT_ECHO_LINK_DOWN: 1790 Echo the inverted Ethernet link state to the fault LED. 1791 1792 Note: If this option is active, then CFG_FAULT_MII_ADDR 1793 also needs to be defined. 1794 1795- CFG_FAULT_MII_ADDR: 1796 MII address of the PHY to check for the Ethernet link state. 1797 1798- CFG_64BIT_VSPRINTF: 1799 Makes vsprintf (and all *printf functions) support printing 1800 of 64bit values by using the L quantifier 1801 1802- CFG_64BIT_STRTOUL: 1803 Adds simple_strtoull that returns a 64bit value 1804 1805Low Level (hardware related) configuration options: 1806--------------------------------------------------- 1807 1808- CFG_CACHELINE_SIZE: 1809 Cache Line Size of the CPU. 1810 1811- CFG_DEFAULT_IMMR: 1812 Default address of the IMMR after system reset. 1813 1814 Needed on some 8260 systems (MPC8260ADS, PQ2FADS-ZU, 1815 and RPXsuper) to be able to adjust the position of 1816 the IMMR register after a reset. 1817 1818- Floppy Disk Support: 1819 CFG_FDC_DRIVE_NUMBER 1820 1821 the default drive number (default value 0) 1822 1823 CFG_ISA_IO_STRIDE 1824 1825 defines the spacing between fdc chipset registers 1826 (default value 1) 1827 1828 CFG_ISA_IO_OFFSET 1829 1830 defines the offset of register from address. It 1831 depends on which part of the data bus is connected to 1832 the fdc chipset. (default value 0) 1833 1834 If CFG_ISA_IO_STRIDE CFG_ISA_IO_OFFSET and 1835 CFG_FDC_DRIVE_NUMBER are undefined, they take their 1836 default value. 1837 1838 if CFG_FDC_HW_INIT is defined, then the function 1839 fdc_hw_init() is called at the beginning of the FDC 1840 setup. fdc_hw_init() must be provided by the board 1841 source code. It is used to make hardware dependant 1842 initializations. 1843 1844- CFG_IMMR: Physical address of the Internal Memory Mapped 1845 Register; DO NOT CHANGE! (11-4) 1846 [MPC8xx systems only] 1847 1848- CFG_INIT_RAM_ADDR: 1849 1850 Start address of memory area that can be used for 1851 initial data and stack; please note that this must be 1852 writable memory that is working WITHOUT special 1853 initialization, i. e. you CANNOT use normal RAM which 1854 will become available only after programming the 1855 memory controller and running certain initialization 1856 sequences. 1857 1858 U-Boot uses the following memory types: 1859 - MPC8xx and MPC8260: IMMR (internal memory of the CPU) 1860 - MPC824X: data cache 1861 - PPC4xx: data cache 1862 1863- CFG_GBL_DATA_OFFSET: 1864 1865 Offset of the initial data structure in the memory 1866 area defined by CFG_INIT_RAM_ADDR. Usually 1867 CFG_GBL_DATA_OFFSET is chosen such that the initial 1868 data is located at the end of the available space 1869 (sometimes written as (CFG_INIT_RAM_END - 1870 CFG_INIT_DATA_SIZE), and the initial stack is just 1871 below that area (growing from (CFG_INIT_RAM_ADDR + 1872 CFG_GBL_DATA_OFFSET) downward. 1873 1874 Note: 1875 On the MPC824X (or other systems that use the data 1876 cache for initial memory) the address chosen for 1877 CFG_INIT_RAM_ADDR is basically arbitrary - it must 1878 point to an otherwise UNUSED address space between 1879 the top of RAM and the start of the PCI space. 1880 1881- CFG_SIUMCR: SIU Module Configuration (11-6) 1882 1883- CFG_SYPCR: System Protection Control (11-9) 1884 1885- CFG_TBSCR: Time Base Status and Control (11-26) 1886 1887- CFG_PISCR: Periodic Interrupt Status and Control (11-31) 1888 1889- CFG_PLPRCR: PLL, Low-Power, and Reset Control Register (15-30) 1890 1891- CFG_SCCR: System Clock and reset Control Register (15-27) 1892 1893- CFG_OR_TIMING_SDRAM: 1894 SDRAM timing 1895 1896- CFG_MAMR_PTA: 1897 periodic timer for refresh 1898 1899- CFG_DER: Debug Event Register (37-47) 1900 1901- FLASH_BASE0_PRELIM, FLASH_BASE1_PRELIM, CFG_REMAP_OR_AM, 1902 CFG_PRELIM_OR_AM, CFG_OR_TIMING_FLASH, CFG_OR0_REMAP, 1903 CFG_OR0_PRELIM, CFG_BR0_PRELIM, CFG_OR1_REMAP, CFG_OR1_PRELIM, 1904 CFG_BR1_PRELIM: 1905 Memory Controller Definitions: BR0/1 and OR0/1 (FLASH) 1906 1907- SDRAM_BASE2_PRELIM, SDRAM_BASE3_PRELIM, SDRAM_MAX_SIZE, 1908 CFG_OR_TIMING_SDRAM, CFG_OR2_PRELIM, CFG_BR2_PRELIM, 1909 CFG_OR3_PRELIM, CFG_BR3_PRELIM: 1910 Memory Controller Definitions: BR2/3 and OR2/3 (SDRAM) 1911 1912- CFG_MAMR_PTA, CFG_MPTPR_2BK_4K, CFG_MPTPR_1BK_4K, CFG_MPTPR_2BK_8K, 1913 CFG_MPTPR_1BK_8K, CFG_MAMR_8COL, CFG_MAMR_9COL: 1914 Machine Mode Register and Memory Periodic Timer 1915 Prescaler definitions (SDRAM timing) 1916 1917- CFG_I2C_UCODE_PATCH, CFG_I2C_DPMEM_OFFSET [0x1FC0]: 1918 enable I2C microcode relocation patch (MPC8xx); 1919 define relocation offset in DPRAM [DSP2] 1920 1921- CFG_SPI_UCODE_PATCH, CFG_SPI_DPMEM_OFFSET [0x1FC0]: 1922 enable SPI microcode relocation patch (MPC8xx); 1923 define relocation offset in DPRAM [SCC4] 1924 1925- CFG_USE_OSCCLK: 1926 Use OSCM clock mode on MBX8xx board. Be careful, 1927 wrong setting might damage your board. Read 1928 doc/README.MBX before setting this variable! 1929 1930- CFG_CPM_POST_WORD_ADDR: (MPC8xx, MPC8260 only) 1931 Offset of the bootmode word in DPRAM used by post 1932 (Power On Self Tests). This definition overrides 1933 #define'd default value in commproc.h resp. 1934 cpm_8260.h. 1935 1936- CFG_PCI_SLV_MEM_LOCAL, CFG_PCI_SLV_MEM_BUS, CFG_PICMR0_MASK_ATTRIB, 1937 CFG_PCI_MSTR0_LOCAL, CFG_PCIMSK0_MASK, CFG_PCI_MSTR1_LOCAL, 1938 CFG_PCIMSK1_MASK, CFG_PCI_MSTR_MEM_LOCAL, CFG_PCI_MSTR_MEM_BUS, 1939 CFG_CPU_PCI_MEM_START, CFG_PCI_MSTR_MEM_SIZE, CFG_POCMR0_MASK_ATTRIB, 1940 CFG_PCI_MSTR_MEMIO_LOCAL, CFG_PCI_MSTR_MEMIO_BUS, CPU_PCI_MEMIO_START, 1941 CFG_PCI_MSTR_MEMIO_SIZE, CFG_POCMR1_MASK_ATTRIB, CFG_PCI_MSTR_IO_LOCAL, 1942 CFG_PCI_MSTR_IO_BUS, CFG_CPU_PCI_IO_START, CFG_PCI_MSTR_IO_SIZE, 1943 CFG_POCMR2_MASK_ATTRIB: (MPC826x only) 1944 Overrides the default PCI memory map in cpu/mpc8260/pci.c if set. 1945 1946Building the Software: 1947====================== 1948 1949Building U-Boot has been tested in native PPC environments (on a 1950PowerBook G3 running LinuxPPC 2000) and in cross environments 1951(running RedHat 6.x and 7.x Linux on x86, Solaris 2.6 on a SPARC, and 1952NetBSD 1.5 on x86). 1953 1954If you are not using a native PPC environment, it is assumed that you 1955have the GNU cross compiling tools available in your path and named 1956with a prefix of "powerpc-linux-". If this is not the case, (e.g. if 1957you are using Monta Vista's Hard Hat Linux CDK 1.2) you must change 1958the definition of CROSS_COMPILE in Makefile. For HHL on a 4xx CPU, 1959change it to: 1960 1961 CROSS_COMPILE = ppc_4xx- 1962 1963 1964U-Boot is intended to be simple to build. After installing the 1965sources you must configure U-Boot for one specific board type. This 1966is done by typing: 1967 1968 make NAME_config 1969 1970where "NAME_config" is the name of one of the existing 1971configurations; the following names are supported: 1972 1973 ADCIOP_config ADS860_config AR405_config 1974 at91rm9200dk_config CANBT_config cmi_mpc5xx_config 1975 cogent_common_config cogent_mpc8260_config cogent_mpc8xx_config 1976 CPCI405_config CPCIISER4_config CU824_config 1977 DUET_ADS_config EBONY_config ELPT860_config 1978 ESTEEM192E_config ETX094_config FADS823_config 1979 FADS850SAR_config FADS860T_config FPS850L_config 1980 FPS860L_config GEN860T_config GENIETV_config 1981 GTH_config hermes_config hymod_config 1982 IP860_config IVML24_config IVMS8_config 1983 JSE_config LANTEC_config lwmon_config 1984 MBX860T_config MBX_config MPC8260ADS_config 1985 MPC8540ADS_config MPC8560ADS_config NETVIA_config 1986 omap1510inn_config omap1610h2_config omap1610inn_config 1987 pcu_e_config PIP405_config QS823_config 1988 QS850_config QS860T_config RPXlite_config 1989 RPXsuper_config rsdproto_config Sandpoint8240_config 1990 sbc8260_config SM850_config SPD823TS_config 1991 SXNI855T_config TQM823L_config TQM850L_config 1992 TQM855L_config TQM860L_config WALNUT405_config 1993 ZPC1900_config 1994 1995 Note: 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 2025 Finally, type "make all", and you should get some working U-Boot 2026 images 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 2033 Please be aware that the Makefiles assume you are using GNU make, so 2034 for instance on NetBSD you might need to use "gmake" instead of 2035 native "make". 2036 2037 2038 If the system board that you have is not listed, then you will need 2039 to port U-Boot to your hardware platform. To do this, follow these 2040 steps: 2041 2042 1. 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. 2047 2. 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". 2050 3. Create a new configuration file "include/configs/<board>.h" for 2051 your board 2052 3. 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. 2054 4. Run "make <board>_config" with your new name. 2055 5. Type "make", and you should get a working "u-boot.srec" file 2056 to be installed on your target system. 2057 6. Debug and solve any problems that might arise. 2058 [Of course, this last step is much harder than it sounds.] 2059 2060 2061 Testing of U-Boot Modifications, Ports to New Hardware, etc.: 2062 ============================================================== 2063 2064 If you have modified U-Boot sources (for instance added a new board 2065 or support for new devices, a new CPU, etc.) you are expected to 2066 provide feedback to the other developers. The feedback normally takes 2067 the form of a "patch", i. e. a context diff against a certain (latest 2068 official or latest in CVS) version of U-Boot sources. 2069 2070 But before you submit such a patch, please verify that your modifi- 2071 cation did not break existing code. At least make sure that *ALL* of 2072 the supported boards compile WITHOUT ANY compiler warnings. To do so, 2073 just run the "MAKEALL" script, which will configure and build U-Boot 2074 for ALL supported system. Be warned, this will take a while. You can 2075 select which (cross) compiler to use by passing a `CROSS_COMPILE' 2076 environment variable to the script, i. e. to use the cross tools from 2077 MontaVista's Hard Hat Linux you can type 2078 2079 CROSS_COMPILE=ppc_8xx- MAKEALL 2080 2081 or to build on a native PowerPC system you can type 2082 2083 CROSS_COMPILE=' ' MAKEALL 2084 2085 See also "U-Boot Porting Guide" below. 2086 2087 2088 Monitor Commands - Overview: 2089 ============================ 2090 2091 go - start application at address 'addr' 2092 run - run commands in an environment variable 2093 bootm - boot application image from memory 2094 bootp - boot image via network using BootP/TFTP protocol 2095 tftpboot- boot image via network using TFTP protocol 2096 and env variables "ipaddr" and "serverip" 2097 (and eventually "gatewayip") 2098 rarpboot- boot image via network using RARP/TFTP protocol 2099 diskboot- boot from IDE devicebootd - boot default, i.e., run 'bootcmd' 2100 loads - load S-Record file over serial line 2101 loadb - load binary file over serial line (kermit mode) 2102 md - memory display 2103 mm - memory modify (auto-incrementing) 2104 nm - memory modify (constant address) 2105 mw - memory write (fill) 2106 cp - memory copy 2107 cmp - memory compare 2108 crc32 - checksum calculation 2109 imd - i2c memory display 2110 imm - i2c memory modify (auto-incrementing) 2111 inm - i2c memory modify (constant address) 2112 imw - i2c memory write (fill) 2113 icrc32 - i2c checksum calculation 2114 iprobe - probe to discover valid I2C chip addresses 2115 iloop - infinite loop on address range 2116 isdram - print SDRAM configuration information 2117 sspi - SPI utility commands 2118 base - print or set address offset 2119 printenv- print environment variables 2120 setenv - set environment variables 2121 saveenv - save environment variables to persistent storage 2122 protect - enable or disable FLASH write protection 2123 erase - erase FLASH memory 2124 flinfo - print FLASH memory information 2125 bdinfo - print Board Info structure 2126 iminfo - print header information for application image 2127 coninfo - print console devices and informations 2128 ide - IDE sub-system 2129 loop - infinite loop on address range 2130 mtest - simple RAM test 2131 icache - enable or disable instruction cache 2132 dcache - enable or disable data cache 2133 reset - Perform RESET of the CPU 2134 echo - echo args to console 2135 version - print monitor version 2136 help - print online help 2137 ? - alias for 'help' 2138 2139 2140 Monitor Commands - Detailed Description: 2141 ======================================== 2142 2143 TODO. 2144 2145 For now: just type "help <command>". 2146 2147 2148 Environment Variables: 2149 ====================== 2150 2151 U-Boot supports user configuration using Environment Variables which 2152 can be made persistent by saving to Flash memory. 2153 2154 Environment Variables are set using "setenv", printed using 2155 "printenv", and saved to Flash using "saveenv". Using "setenv" 2156 without a value can be used to delete a variable from the 2157 environment. As long as you don't save the environment you are 2158 working with an in-memory copy. In case the Flash area containing the 2159 environment is erased by accident, a default environment is provided. 2160 2161 Some 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 2254 The following environment variables may be used and automatically 2255 updated by the network boot commands ("bootp" and "rarpboot"), 2256 depending 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 2269 There 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 2275 These variables can be set only once (usually during manufacturing of 2276 the board). U-Boot refuses to delete or overwrite these variables 2277 once they have been set once. 2278 2279 2280 Further 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 2287 Please note that changes to some configuration parameters may take 2288 only effect after the next boot (yes, that's just like Windoze :-). 2289 2290 2291 Command Line Parsing: 2292 ===================== 2293 2294 There are two different command line parsers available with U-Boot: 2295 the old "simple" one, and the much more powerful "hush" shell: 2296 2297 Old, 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 2309 Hush 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 2320 General 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 2333 Note for Redundant Ethernet Interfaces: 2334 ======================================= 2335 2336 Some boards come with redundant ethernet interfaces; U-Boot supports 2337 such configurations and is capable of automatic selection of a 2338 "working" interface when needed. MAC assignment works as follows: 2339 2340 Network interfaces are numbered eth0, eth1, eth2, ... Corresponding 2341 MAC addresses can be stored in the environment as "ethaddr" (=>eth0), 2342 "eth1addr" (=>eth1), "eth2addr", ... 2343 2344 If the network interface stores some valid MAC address (for instance 2345 in SROM), this is used as default address if there is NO correspon- 2346 ding setting in the environment; if the corresponding environment 2347 variable is set, this overrides the settings in the card; that means: 2348 2349 o If the SROM has a valid MAC address, and there is no address in the 2350 environment, the SROM's address is used. 2351 2352 o 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 2356 o If both the SROM and the environment contain a MAC address, and 2357 both addresses are the same, this MAC address is used. 2358 2359 o 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 2363 o If neither SROM nor the environment contain a MAC address, an error 2364 is raised. 2365 2366 2367 Image Formats: 2368 ============== 2369 2370 The "boot" commands of this monitor operate on "image" files which 2371 can be basicly anything, preceeded by a special header; see the 2372 definitions in include/image.h for details; basicly, the header 2373 defines 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 2388 The header is marked by a special Magic Number, and both the header 2389 and the data portions of the image are secured against corruption by 2390 CRC32 checksums. 2391 2392 2393 Linux Support: 2394 ============== 2395 2396 Although U-Boot should support any OS or standalone application 2397 easily, the main focus has always been on Linux during the design of 2398 U-Boot. 2399 2400 U-Boot includes many features that so far have been part of some 2401 special "boot loader" code within the Linux kernel. Also, any 2402 "initrd" images to be used are no longer part of one big Linux image; 2403 instead, kernel and "initrd" are separate images. This implementation 2404 serves 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 2421 Linux HOWTO: 2422 ============ 2423 2424 Porting Linux to U-Boot based systems: 2425 --------------------------------------- 2426 2427 U-Boot cannot save you from doing all the necessary modifications to 2428 configure the Linux device drivers for use with your target hardware 2429 (no, we don't intend to provide a full virtual machine interface to 2430 Linux :-). 2431 2432 But now you can ignore ALL boot loader code (in arch/ppc/mbxboot). 2433 2434 Just make sure your machine specific header file (for instance 2435 include/asm-ppc/tqm8xx.h) includes the same definition of the Board 2436 Information structure as we define in include/u-boot.h, and make 2437 sure that your definition of IMAP_ADDR uses the same value as your 2438 U-Boot configuration in CFG_IMMR. 2439 2440 2441 Configuring the Linux kernel: 2442 ----------------------------- 2443 2444 No specific requirements for U-Boot. Make sure you have some root 2445 device (initial ramdisk, NFS) for your target system. 2446 2447 2448 Building a Linux Image: 2449 ----------------------- 2450 2451 With U-Boot, "normal" build targets like "zImage" or "bzImage" are 2452 not used. If you use recent kernel source, a new build target 2453 "uImage" will exist which automatically builds an image usable by 2454 U-Boot. Most older kernels also have support for a "pImage" target, 2455 which was introduced for our predecessor project PPCBoot and uses a 2456 100% compatible format. 2457 2458 Example: 2459 2460 make TQM850L_config 2461 make oldconfig 2462 make dep 2463 make uImage 2464 2465 The "uImage" build target uses a special tool (in 'tools/mkimage') to 2466 encapsulate a compressed Linux kernel image with header information, 2467 CRC32 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 2488 The "mkimage" tool can also be used to create ramdisk images for use 2489 with U-Boot, either separated from the Linux kernel image, or 2490 combined into one file. "mkimage" encapsulates the images with a 64 2491 byte header containing information about target architecture, 2492 operating system, image type, compression method, entry points, time 2493 stamp, CRC32 checksums, etc. 2494 2495 "mkimage" can be called in two ways: to verify existing images and 2496 print the header information, or to build new images. 2497 2498 In the first form (with "-l" option) mkimage lists the information 2499 contained in the header of an existing U-Boot image; this includes 2500 checksum verification: 2501 2502 tools/mkimage -l image 2503 -l ==> list image header information 2504 2505 The second form (with "-d" option) is used to build a U-Boot image 2506 from 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 2519 Right now, all Linux kernels use the same load address (0x00000000), 2520 but 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 2525 So 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 2538 To 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 2548 NOTE: for embedded systems where boot time is critical you can trade 2549 speed for memory and install an UNCOMPRESSED image instead: this 2550 needs more space in Flash, but boots much faster since it does not 2551 need 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 2566 Similar you can build U-Boot images from a 'ramdisk.image.gz' file 2567 when 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 2580 Installing a Linux Image: 2581 ------------------------- 2582 2583 To downloading a U-Boot image over the serial (console) interface, 2584 you must convert the image to S-Record format: 2585 2586 objcopy -I binary -O srec examples/image examples/image.srec 2587 2588 The 'objcopy' does not understand the information in the U-Boot 2589 image header, so the resulting S-Record file will be relative to 2590 address 0x00000000. To load it to a given address, you need to 2591 specify the target address as 'offset' parameter with the 'loads' 2592 command. 2593 2594 Example: install the image to address 0x40100000 (which on the 2595 TQM8xxL 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 2613 You can check the success of the download using the 'iminfo' command; 2614 this includes a checksum verification so you can be sure no data 2615 corruption 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 2628 Boot Linux: 2629 ----------- 2630 2631 The "bootm" command is used to boot an application that is stored in 2632 memory (RAM or Flash). In case of a Linux kernel image, the contents 2633 of the "bootargs" environment variable is passed to the kernel as 2634 parameters. 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 2662 If you want to boot a Linux kernel with initial ram disk, you pass 2663 the memory addresses of both the kernel and the initrd image (PPBCOOT 2664 format!) 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 2711 More About U-Boot Image Types: 2712 ------------------------------ 2713 2714 U-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 2752 Standalone HOWTO: 2753 ================= 2754 2755 One of the features of U-Boot is that you can dynamically load and 2756 run "standalone" applications, which can use some resources of 2757 U-Boot like console I/O functions or interrupt services. 2758 2759 Two 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 2765 application; it is automatically compiled when you build U-Boot. 2766 It's configured to run at address 0x00040004, so you can play with it 2767 like 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 2793 Another example, which demonstrates how to register a CPM interrupt 2794 handler with the U-Boot code, can be found in 'examples/timer.c'. 2795 Here, a CPM timer is set up to generate an interrupt every second. 2796 The interrupt service routine is trivial, just printing a '.' 2797 character, but this is just a demo program. The application can be 2798 controlled 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 2819 Hit 'b': 2820 [q, b, e, ?] Set interval 1000000 us 2821 Enabling timer 2822 Hit '?': 2823 [q, b, e, ?] ........ 2824 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0xef6, ter=0x0 2825 Hit '?': 2826 [q, b, e, ?] . 2827 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x2ad4, ter=0x0 2828 Hit '?': 2829 [q, b, e, ?] . 2830 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x1efc, ter=0x0 2831 Hit '?': 2832 [q, b, e, ?] . 2833 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x169d, ter=0x0 2834 Hit 'e': 2835 [q, b, e, ?] ...Stopping timer 2836 Hit 'q': 2837 [q, b, e, ?] ## Application terminated, rc = 0x0 2838 2839 2840 Minicom warning: 2841 ================ 2842 2843 Over time, many people have reported problems when trying to use the 2844 "minicom" terminal emulation program for serial download. I (wd) 2845 consider minicom to be broken, and recommend not to use it. Under 2846 Unix, I recommend to use C-Kermit for general purpose use (and 2847 especially for kermit binary protocol download ("loadb" command), and 2848 use "cu" for S-Record download ("loads" command). 2849 2850 Nevertheless, if you absolutely want to use it try adding this 2851 configuration 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 2858 NetBSD Notes: 2859 ============= 2860 2861 Starting at version 0.9.2, U-Boot supports NetBSD both as host 2862 (build U-Boot) and target system (boots NetBSD/mpc8xx). 2863 2864 Building requires a cross environment; it is known to work on 2865 NetBSD/i386 with the cross-powerpc-netbsd-1.3 package (you will also 2866 need gmake since the Makefiles are not compatible with BSD make). 2867 Note that the cross-powerpc package does not install include files; 2868 attempting to build U-Boot will fail because <machine/ansi.h> is 2869 missing. 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 2877 Native builds *don't* work due to incompatibilities between native 2878 and U-Boot include files. 2879 2880 Booting assumes that (the first part of) the image booted is a 2881 stage-2 loader which in turn loads and then invokes the kernel 2882 proper. Loader sources will eventually appear in the NetBSD source 2883 tree (probably in sys/arc/mpc8xx/stand/u-boot_stage2/); in the 2884 meantime, send mail to bruno@exet-ag.de and/or wd@denx.de for 2885 details. 2886 2887 2888 Implementation Internals: 2889 ========================= 2890 2891 The following is not intended to be a complete description of every 2892 implementation detail. However, it should help to understand the 2893 inner workings of U-Boot and make it easier to port it to custom 2894 hardware. 2895 2896 2897 Initial Stack, Global Data: 2898 --------------------------- 2899 2900 The implementation of U-Boot is complicated by the fact that U-Boot 2901 starts running out of ROM (flash memory), usually without access to 2902 system RAM (because the memory controller is not initialized yet). 2903 This means that we don't have writable Data or BSS segments, and BSS 2904 is not initialized as zero. To be able to get a C environment working 2905 at all, we have to allocate at least a minimal stack. Implementation 2906 options for this are defined and restricted by the CPU used: Some CPU 2907 models provide on-chip memory (like the IMMR area on MPC8xx and 2908 MPC826x processors), on others (parts of) the data cache can be 2909 locked 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 2949 It is essential to remember this, since it has some impact on the C 2950 code 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 2962 Having only the stack as writable memory limits means we cannot use 2963 normal global data to share information beween the code. But it 2964 turned out that the implementation of U-Boot can be greatly 2965 simplified by making a global data structure (gd_t) available to all 2966 functions. We could pass a pointer to this data as argument to _all_ 2967 functions, but this would bloat the code. Instead we use a feature of 2968 the GCC compiler (Global Register Variables) to share the data: we 2969 place a pointer (gd) to the global data into a register which we 2970 reserve for this purpose. 2971 2972 When choosing a register for such a purpose we are restricted by the 2973 relevant (E)ABI specifications for the current architecture, and by 2974 GCC's implementation. 2975 2976 For 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 2996 On 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 3011 Memory Management: 3012 ------------------ 3013 3014 U-Boot runs in system state and uses physical addresses, i.e. the 3015 MMU is not used either for address mapping nor for memory protection. 3016 3017 The available memory is mapped to fixed addresses using the memory 3018 controller. In this process, a contiguous block is formed for each 3019 memory type (Flash, SDRAM, SRAM), even when it consists of several 3020 physical memory banks. 3021 3022 U-Boot is installed in the first 128 kB of the first Flash bank (on 3023 TQM8xxL modules this is the range 0x40000000 ... 0x4001FFFF). After 3024 booting and sizing and initializing DRAM, the code relocates itself 3025 to the upper end of DRAM. Immediately below the U-Boot code some 3026 memory is reserved for use by malloc() [see CFG_MALLOC_LEN 3027 configuration setting]. Below that, a structure with global Board 3028 Info data is placed, followed by the stack (growing downward). 3029 3030 Additionally, some exception handler code is copied to the low 8 kB 3031 of DRAM (0x00000000 ... 0x00001FFF). 3032 3033 So a typical memory configuration with 16 MB of DRAM could look like 3034 this: 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 3056 System Initialization: 3057 ---------------------- 3058 3059 In the reset configuration, U-Boot starts at the reset entry point 3060 (on most PowerPC systens at address 0x00000100). Because of the reset 3061 configuration for CS0# this is a mirror of the onboard Flash memory. 3062 To be able to re-map memory U-Boot then jumps to its link address. 3063 To be able to implement the initialization code in C, a (small!) 3064 initial stack is set up in the internal Dual Ported RAM (in case CPUs 3065 which provide such a feature like MPC8xx or MPC8260), or in a locked 3066 part of the data cache. After that, U-Boot initializes the CPU core, 3067 the caches and the SIU. 3068 3069 Next, all (potentially) available memory banks are mapped using a 3070 preliminary mapping. For example, we put them on 512 MB boundaries 3071 (multiples of 0x20000000: SDRAM on 0x00000000 and 0x20000000, Flash 3072 on 0x40000000 and 0x60000000, SRAM on 0x80000000). Then UPM A is 3073 programmed for SDRAM access. Using the temporary configuration, a 3074 simple memory test is run that determines the size of the SDRAM 3075 banks. 3076 3077 When there is more than one SDRAM bank, and the banks are of 3078 different size, the largest is mapped first. For equal size, the first 3079 bank (CS2#) is mapped first. The first mapping is always for address 3080 0x00000000, with any additional banks following immediately to create 3081 contiguous memory starting from 0. 3082 3083 Then, the monitor installs itself at the upper end of the SDRAM area 3084 and allocates memory for use by malloc() and for the global Board 3085 Info data; also, the exception vector code is copied to the low RAM 3086 pages, and the final stack is set up. 3087 3088 Only after this relocation will you have a "normal" C environment; 3089 until that you are restricted in several ways, mostly because you are 3090 running from ROM, and because the code will have to be relocated to a 3091 new address in RAM. 3092 3093 3094 U-Boot Porting Guide: 3095 ---------------------- 3096 3097 [Based on messages by Jerry Van Baren in the U-Boot-Users mailing 3098 list, October 2002] 3099 3100 3101 int 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 3150 void no_more_time (int sig) 3151 { 3152 hire_a_guru(); 3153 } 3154 3155 3156 Coding Standards: 3157 ----------------- 3158 3159 All contributions to U-Boot should conform to the Linux kernel 3160 coding style; see the file "Documentation/CodingStyle" in your Linux 3161 kernel source directory. 3162 3163 Please note that U-Boot is implemented in C (and to some small parts 3164 in Assembler); no C++ is used, so please do not use C++ style 3165 comments (//) in your code. 3166 3167 Please 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 3174 Submissions which do not conform to the standards may be returned 3175 with a request to reformat the changes. 3176 3177 3178 Submitting Patches: 3179 ------------------- 3180 3181 Since the number of patches for U-Boot is growing, we need to 3182 establish some rules. Submissions which do not conform to these rules 3183 may be rejected, even when they contain important and valuable stuff. 3184 3185 3186 When you send a patch, please include the following information with 3187 it: 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 3226 Notes: 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