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 MicroBlaze based CPUs: 244 ---------------------- 245 CONFIG_MICROBLZE 246 247 248- Board Type: Define exactly one of 249 250 PowerPC based boards: 251 --------------------- 252 253 CONFIG_ADCIOP, CONFIG_ADS860, CONFIG_AMX860, 254 CONFIG_AR405, CONFIG_BAB7xx, CONFIG_c2mon, 255 CONFIG_CANBT, CONFIG_CCM, CONFIG_CMI, 256 CONFIG_cogent_mpc8260, CONFIG_cogent_mpc8xx, CONFIG_CPCI405, 257 CONFIG_CPCI4052, CONFIG_CPCIISER4, CONFIG_CPU86, 258 CONFIG_CRAYL1, CONFIG_CU824, CONFIG_DASA_SIM, 259 CONFIG_DB64360, CONFIG_DB64460, CONFIG_DU405, 260 CONFIG_DUET_ADS, CONFIG_EBONY, CONFIG_ELPPC, 261 CONFIG_ELPT860, CONFIG_ep8260, CONFIG_ERIC, 262 CONFIG_ESTEEM192E, CONFIG_ETX094, CONFIG_EVB64260, 263 CONFIG_FADS823, CONFIG_FADS850SAR, CONFIG_FADS860T, 264 CONFIG_FLAGADM, CONFIG_FPS850L, CONFIG_FPS860L, 265 CONFIG_GEN860T, CONFIG_GENIETV, CONFIG_GTH, 266 CONFIG_gw8260, CONFIG_hermes, CONFIG_hymod, 267 CONFIG_IAD210, CONFIG_ICU862, CONFIG_IP860, 268 CONFIG_IPHASE4539, CONFIG_IVML24, CONFIG_IVML24_128, 269 CONFIG_IVML24_256, CONFIG_IVMS8, CONFIG_IVMS8_128, 270 CONFIG_IVMS8_256, CONFIG_JSE, CONFIG_LANTEC, 271 CONFIG_lwmon, CONFIG_MBX, CONFIG_MBX860T, 272 CONFIG_MHPC, CONFIG_MIP405, CONFIG_MOUSSE, 273 CONFIG_MPC8260ADS, CONFIG_MPC8540ADS, CONFIG_MPC8560ADS, 274 CONFIG_MUSENKI, CONFIG_MVS1, CONFIG_NETPHONE, 275 CONFIG_NETTA, CONFIG_NETVIA, CONFIG_NX823, 276 CONFIG_OCRTC, CONFIG_ORSG, CONFIG_OXC, 277 CONFIG_PCI405, CONFIG_PCIPPC2, CONFIG_PCIPPC6, 278 CONFIG_pcu_e, CONFIG_PIP405, CONFIG_PM826, 279 CONFIG_ppmc8260, CONFIG_QS823, CONFIG_QS850, 280 CONFIG_QS860T, CONFIG_RBC823, CONFIG_RPXClassic, 281 CONFIG_RPXlite, CONFIG_RPXsuper, CONFIG_rsdproto, 282 CONFIG_sacsng, CONFIG_Sandpoint8240, CONFIG_Sandpoint8245, 283 CONFIG_sbc8260, CONFIG_SM850, CONFIG_SPD823TS, 284 CONFIG_STXGP3, CONFIG_SXNI855T, CONFIG_TQM823L, 285 CONFIG_TQM8260, CONFIG_TQM850L, CONFIG_TQM855L, 286 CONFIG_TQM860L, CONFIG_TTTech, CONFIG_UTX8245, 287 CONFIG_V37, CONFIG_W7OLMC, CONFIG_W7OLMG, 288 CONFIG_WALNUT405, CONFIG_ZPC1900, CONFIG_ZUMA, 289 290 ARM based boards: 291 ----------------- 292 293 CONFIG_AT91RM9200DK, CONFIG_DNP1110, CONFIG_EP7312, 294 CONFIG_H2_OMAP1610, CONFIG_HHP_CRADLE, CONFIG_IMPA7, 295 CONFIG_INNOVATOROMAP1510, CONFIG_INNOVATOROMAP1610, CONFIG_LART, 296 CONFIG_LUBBOCK, CONFIG_SHANNON, CONFIG_SMDK2400, 297 CONFIG_SMDK2410, CONFIG_TRAB, CONFIG_VCMA9, 298 299 MicroBlaze based boards: 300 ------------------------ 301 302 CONFIG_SUZAKU 303 304 305- CPU Module Type: (if CONFIG_COGENT is defined) 306 Define exactly one of 307 CONFIG_CMA286_60_OLD 308--- FIXME --- not tested yet: 309 CONFIG_CMA286_60, CONFIG_CMA286_21, CONFIG_CMA286_60P, 310 CONFIG_CMA287_23, CONFIG_CMA287_50 311 312- Motherboard Type: (if CONFIG_COGENT is defined) 313 Define exactly one of 314 CONFIG_CMA101, CONFIG_CMA102 315 316- Motherboard I/O Modules: (if CONFIG_COGENT is defined) 317 Define one or more of 318 CONFIG_CMA302 319 320- Motherboard Options: (if CONFIG_CMA101 or CONFIG_CMA102 are defined) 321 Define one or more of 322 CONFIG_LCD_HEARTBEAT - update a character position on 323 the lcd display every second with 324 a "rotator" |\-/|\-/ 325 326- Board flavour: (if CONFIG_MPC8260ADS is defined) 327 CONFIG_ADSTYPE 328 Possible values are: 329 CFG_8260ADS - original MPC8260ADS 330 CFG_8266ADS - MPC8266ADS 331 CFG_PQ2FADS - PQ2FADS-ZU or PQ2FADS-VR 332 CFG_8272ADS - MPC8272ADS 333 334- MPC824X Family Member (if CONFIG_MPC824X is defined) 335 Define exactly one of 336 CONFIG_MPC8240, CONFIG_MPC8245 337 338- 8xx CPU Options: (if using an MPC8xx cpu) 339 Define one or more of 340 CONFIG_8xx_GCLK_FREQ - if get_gclk_freq() cannot work 341 e.g. if there is no 32KHz 342 reference PIT/RTC clock 343 344- 859/866 CPU options: (if using a MPC859 or MPC866 CPU): 345 CFG_866_OSCCLK 346 CFG_866_CPUCLK_MIN 347 CFG_866_CPUCLK_MAX 348 CFG_866_CPUCLK_DEFAULT 349 See doc/README.MPC866 350 351 CFG_MEASURE_CPUCLK 352 353 Define this to measure the actual CPU clock instead 354 of relying on the correctness of the configured 355 values. Mostly useful for board bringup to make sure 356 the PLL is locked at the intended frequency. Note 357 that this requires a (stable) reference clock (32 kHz 358 RTC clock), 359 360- Linux Kernel Interface: 361 CONFIG_CLOCKS_IN_MHZ 362 363 U-Boot stores all clock information in Hz 364 internally. For binary compatibility with older Linux 365 kernels (which expect the clocks passed in the 366 bd_info data to be in MHz) the environment variable 367 "clocks_in_mhz" can be defined so that U-Boot 368 converts clock data to MHZ before passing it to the 369 Linux kernel. 370 When CONFIG_CLOCKS_IN_MHZ is defined, a definition of 371 "clocks_in_mhz=1" is automatically included in the 372 default environment. 373 374 CONFIG_MEMSIZE_IN_BYTES [relevant for MIPS only] 375 376 When transfering memsize parameter to linux, some versions 377 expect it to be in bytes, others in MB. 378 Define CONFIG_MEMSIZE_IN_BYTES to make it in bytes. 379 380- Console Interface: 381 Depending on board, define exactly one serial port 382 (like CONFIG_8xx_CONS_SMC1, CONFIG_8xx_CONS_SMC2, 383 CONFIG_8xx_CONS_SCC1, ...), or switch off the serial 384 console by defining CONFIG_8xx_CONS_NONE 385 386 Note: if CONFIG_8xx_CONS_NONE is defined, the serial 387 port routines must be defined elsewhere 388 (i.e. serial_init(), serial_getc(), ...) 389 390 CONFIG_CFB_CONSOLE 391 Enables console device for a color framebuffer. Needs following 392 defines (cf. smiLynxEM, i8042, board/eltec/bab7xx) 393 VIDEO_FB_LITTLE_ENDIAN graphic memory organisation 394 (default big endian) 395 VIDEO_HW_RECTFILL graphic chip supports 396 rectangle fill 397 (cf. smiLynxEM) 398 VIDEO_HW_BITBLT graphic chip supports 399 bit-blit (cf. smiLynxEM) 400 VIDEO_VISIBLE_COLS visible pixel columns 401 (cols=pitch) 402 VIDEO_VISIBLE_ROWS visible pixel rows 403 VIDEO_PIXEL_SIZE bytes per pixel 404 VIDEO_DATA_FORMAT graphic data format 405 (0-5, cf. cfb_console.c) 406 VIDEO_FB_ADRS framebuffer address 407 VIDEO_KBD_INIT_FCT keyboard int fct 408 (i.e. i8042_kbd_init()) 409 VIDEO_TSTC_FCT test char fct 410 (i.e. i8042_tstc) 411 VIDEO_GETC_FCT get char fct 412 (i.e. i8042_getc) 413 CONFIG_CONSOLE_CURSOR cursor drawing on/off 414 (requires blink timer 415 cf. i8042.c) 416 CFG_CONSOLE_BLINK_COUNT blink interval (cf. i8042.c) 417 CONFIG_CONSOLE_TIME display time/date info in 418 upper right corner 419 (requires CFG_CMD_DATE) 420 CONFIG_VIDEO_LOGO display Linux logo in 421 upper left corner 422 CONFIG_VIDEO_BMP_LOGO use bmp_logo.h instead of 423 linux_logo.h for logo. 424 Requires CONFIG_VIDEO_LOGO 425 CONFIG_CONSOLE_EXTRA_INFO 426 addional board info beside 427 the logo 428 429 When CONFIG_CFB_CONSOLE is defined, video console is 430 default i/o. Serial console can be forced with 431 environment 'console=serial'. 432 433 When CONFIG_SILENT_CONSOLE is defined, all console 434 messages (by U-Boot and Linux!) can be silenced with 435 the "silent" environment variable. See 436 doc/README.silent for more information. 437 438- Console Baudrate: 439 CONFIG_BAUDRATE - in bps 440 Select one of the baudrates listed in 441 CFG_BAUDRATE_TABLE, see below. 442 CFG_BRGCLK_PRESCALE, baudrate prescale 443 444- Interrupt driven serial port input: 445 CONFIG_SERIAL_SOFTWARE_FIFO 446 447 PPC405GP only. 448 Use an interrupt handler for receiving data on the 449 serial port. It also enables using hardware handshake 450 (RTS/CTS) and UART's built-in FIFO. Set the number of 451 bytes the interrupt driven input buffer should have. 452 453 Leave undefined to disable this feature, including 454 disable the buffer and hardware handshake. 455 456- Console UART Number: 457 CONFIG_UART1_CONSOLE 458 459 IBM PPC4xx only. 460 If defined internal UART1 (and not UART0) is used 461 as default U-Boot console. 462 463- Boot Delay: CONFIG_BOOTDELAY - in seconds 464 Delay before automatically booting the default image; 465 set to -1 to disable autoboot. 466 467 See doc/README.autoboot for these options that 468 work with CONFIG_BOOTDELAY. None are required. 469 CONFIG_BOOT_RETRY_TIME 470 CONFIG_BOOT_RETRY_MIN 471 CONFIG_AUTOBOOT_KEYED 472 CONFIG_AUTOBOOT_PROMPT 473 CONFIG_AUTOBOOT_DELAY_STR 474 CONFIG_AUTOBOOT_STOP_STR 475 CONFIG_AUTOBOOT_DELAY_STR2 476 CONFIG_AUTOBOOT_STOP_STR2 477 CONFIG_ZERO_BOOTDELAY_CHECK 478 CONFIG_RESET_TO_RETRY 479 480- Autoboot Command: 481 CONFIG_BOOTCOMMAND 482 Only needed when CONFIG_BOOTDELAY is enabled; 483 define a command string that is automatically executed 484 when no character is read on the console interface 485 within "Boot Delay" after reset. 486 487 CONFIG_BOOTARGS 488 This can be used to pass arguments to the bootm 489 command. The value of CONFIG_BOOTARGS goes into the 490 environment value "bootargs". 491 492 CONFIG_RAMBOOT and CONFIG_NFSBOOT 493 The value of these goes into the environment as 494 "ramboot" and "nfsboot" respectively, and can be used 495 as a convenience, when switching between booting from 496 ram and nfs. 497 498- Pre-Boot Commands: 499 CONFIG_PREBOOT 500 501 When this option is #defined, the existence of the 502 environment variable "preboot" will be checked 503 immediately before starting the CONFIG_BOOTDELAY 504 countdown and/or running the auto-boot command resp. 505 entering interactive mode. 506 507 This feature is especially useful when "preboot" is 508 automatically generated or modified. For an example 509 see the LWMON board specific code: here "preboot" is 510 modified when the user holds down a certain 511 combination of keys on the (special) keyboard when 512 booting the systems 513 514- Serial Download Echo Mode: 515 CONFIG_LOADS_ECHO 516 If defined to 1, all characters received during a 517 serial download (using the "loads" command) are 518 echoed back. This might be needed by some terminal 519 emulations (like "cu"), but may as well just take 520 time on others. This setting #define's the initial 521 value of the "loads_echo" environment variable. 522 523- Kgdb Serial Baudrate: (if CFG_CMD_KGDB is defined) 524 CONFIG_KGDB_BAUDRATE 525 Select one of the baudrates listed in 526 CFG_BAUDRATE_TABLE, see below. 527 528- Monitor Functions: 529 CONFIG_COMMANDS 530 Most monitor functions can be selected (or 531 de-selected) by adjusting the definition of 532 CONFIG_COMMANDS; to select individual functions, 533 #define CONFIG_COMMANDS by "OR"ing any of the 534 following values: 535 536 #define enables commands: 537 ------------------------- 538 CFG_CMD_ASKENV * ask for env variable 539 CFG_CMD_AUTOSCRIPT Autoscript Support 540 CFG_CMD_BDI bdinfo 541 CFG_CMD_BEDBUG Include BedBug Debugger 542 CFG_CMD_BMP * BMP support 543 CFG_CMD_BOOTD bootd 544 CFG_CMD_CACHE icache, dcache 545 CFG_CMD_CONSOLE coninfo 546 CFG_CMD_DATE * support for RTC, date/time... 547 CFG_CMD_DHCP DHCP support 548 CFG_CMD_DIAG * Diagnostics 549 CFG_CMD_DOC * Disk-On-Chip Support 550 CFG_CMD_DTT Digital Therm and Thermostat 551 CFG_CMD_ECHO * echo arguments 552 CFG_CMD_EEPROM * EEPROM read/write support 553 CFG_CMD_ELF bootelf, bootvx 554 CFG_CMD_ENV saveenv 555 CFG_CMD_FDC * Floppy Disk Support 556 CFG_CMD_FAT FAT partition support 557 CFG_CMD_FDOS * Dos diskette Support 558 CFG_CMD_FLASH flinfo, erase, protect 559 CFG_CMD_FPGA FPGA device initialization support 560 CFG_CMD_HWFLOW * RTS/CTS hw flow control 561 CFG_CMD_I2C * I2C serial bus support 562 CFG_CMD_IDE * IDE harddisk support 563 CFG_CMD_IMI iminfo 564 CFG_CMD_IMLS List all found images 565 CFG_CMD_IMMAP * IMMR dump support 566 CFG_CMD_IRQ * irqinfo 567 CFG_CMD_ITEST * Integer/string test of 2 values 568 CFG_CMD_JFFS2 * JFFS2 Support 569 CFG_CMD_KGDB * kgdb 570 CFG_CMD_LOADB loadb 571 CFG_CMD_LOADS loads 572 CFG_CMD_MEMORY md, mm, nm, mw, cp, cmp, crc, base, 573 loop, mtest 574 CFG_CMD_MISC Misc functions like sleep etc 575 CFG_CMD_MMC MMC memory mapped support 576 CFG_CMD_MII MII utility commands 577 CFG_CMD_NAND * NAND support 578 CFG_CMD_NET bootp, tftpboot, rarpboot 579 CFG_CMD_PCI * pciinfo 580 CFG_CMD_PCMCIA * PCMCIA support 581 CFG_CMD_PING * send ICMP ECHO_REQUEST to network host 582 CFG_CMD_PORTIO * Port I/O 583 CFG_CMD_REGINFO * Register dump 584 CFG_CMD_RUN run command in env variable 585 CFG_CMD_SAVES save S record dump 586 CFG_CMD_SCSI * SCSI Support 587 CFG_CMD_SDRAM * print SDRAM configuration information 588 CFG_CMD_SETGETDCR Support for DCR Register access (4xx only) 589 CFG_CMD_SPI * SPI serial bus support 590 CFG_CMD_USB * USB support 591 CFG_CMD_VFD * VFD support (TRAB) 592 CFG_CMD_BSP * Board SPecific functions 593 CFG_CMD_CDP * Cisco Discover Protocol support 594 ----------------------------------------------- 595 CFG_CMD_ALL all 596 597 CFG_CMD_DFL Default configuration; at the moment 598 this is includes all commands, except 599 the ones marked with "*" in the list 600 above. 601 602 If you don't define CONFIG_COMMANDS it defaults to 603 CFG_CMD_DFL in include/cmd_confdefs.h. A board can 604 override the default settings in the respective 605 include file. 606 607 EXAMPLE: If you want all functions except of network 608 support you can write: 609 610 #define CONFIG_COMMANDS (CFG_CMD_ALL & ~CFG_CMD_NET) 611 612 613 Note: Don't enable the "icache" and "dcache" commands 614 (configuration option CFG_CMD_CACHE) unless you know 615 what you (and your U-Boot users) are doing. Data 616 cache cannot be enabled on systems like the 8xx or 617 8260 (where accesses to the IMMR region must be 618 uncached), and it cannot be disabled on all other 619 systems where we (mis-) use the data cache to hold an 620 initial stack and some data. 621 622 623 XXX - this list needs to get updated! 624 625- Watchdog: 626 CONFIG_WATCHDOG 627 If this variable is defined, it enables watchdog 628 support. There must be support in the platform specific 629 code for a watchdog. For the 8xx and 8260 CPUs, the 630 SIU Watchdog feature is enabled in the SYPCR 631 register. 632 633- U-Boot Version: 634 CONFIG_VERSION_VARIABLE 635 If this variable is defined, an environment variable 636 named "ver" is created by U-Boot showing the U-Boot 637 version as printed by the "version" command. 638 This variable is readonly. 639 640- Real-Time Clock: 641 642 When CFG_CMD_DATE is selected, the type of the RTC 643 has to be selected, too. Define exactly one of the 644 following options: 645 646 CONFIG_RTC_MPC8xx - use internal RTC of MPC8xx 647 CONFIG_RTC_PCF8563 - use Philips PCF8563 RTC 648 CONFIG_RTC_MC146818 - use MC146818 RTC 649 CONFIG_RTC_DS1307 - use Maxim, Inc. DS1307 RTC 650 CONFIG_RTC_DS1337 - use Maxim, Inc. DS1337 RTC 651 CONFIG_RTC_DS1338 - use Maxim, Inc. DS1338 RTC 652 CONFIG_RTC_DS164x - use Dallas DS164x RTC 653 654 Note that if the RTC uses I2C, then the I2C interface 655 must also be configured. See I2C Support, below. 656 657- Timestamp Support: 658 659 When CONFIG_TIMESTAMP is selected, the timestamp 660 (date and time) of an image is printed by image 661 commands like bootm or iminfo. This option is 662 automatically enabled when you select CFG_CMD_DATE . 663 664- Partition Support: 665 CONFIG_MAC_PARTITION and/or CONFIG_DOS_PARTITION 666 and/or CONFIG_ISO_PARTITION 667 668 If IDE or SCSI support is enabled (CFG_CMD_IDE or 669 CFG_CMD_SCSI) you must configure support for at least 670 one partition type as well. 671 672- IDE Reset method: 673 CONFIG_IDE_RESET_ROUTINE - this is defined in several 674 board configurations files but used nowhere! 675 676 CONFIG_IDE_RESET - is this is defined, IDE Reset will 677 be performed by calling the function 678 ide_set_reset(int reset) 679 which has to be defined in a board specific file 680 681- ATAPI Support: 682 CONFIG_ATAPI 683 684 Set this to enable ATAPI support. 685 686- LBA48 Support 687 CONFIG_LBA48 688 689 Set this to enable support for disks larger than 137GB 690 Also look at CFG_64BIT_LBA ,CFG_64BIT_VSPRINTF and CFG_64BIT_STRTOUL 691 Whithout these , LBA48 support uses 32bit variables and will 'only' 692 support disks up to 2.1TB. 693 694 CFG_64BIT_LBA: 695 When enabled, makes the IDE subsystem use 64bit sector addresses. 696 Default is 32bit. 697 698- SCSI Support: 699 At the moment only there is only support for the 700 SYM53C8XX SCSI controller; define 701 CONFIG_SCSI_SYM53C8XX to enable it. 702 703 CFG_SCSI_MAX_LUN [8], CFG_SCSI_MAX_SCSI_ID [7] and 704 CFG_SCSI_MAX_DEVICE [CFG_SCSI_MAX_SCSI_ID * 705 CFG_SCSI_MAX_LUN] can be adjusted to define the 706 maximum numbers of LUNs, SCSI ID's and target 707 devices. 708 CFG_SCSI_SYM53C8XX_CCF to fix clock timing (80Mhz) 709 710- NETWORK Support (PCI): 711 CONFIG_E1000 712 Support for Intel 8254x gigabit chips. 713 714 CONFIG_EEPRO100 715 Support for Intel 82557/82559/82559ER chips. 716 Optional CONFIG_EEPRO100_SROM_WRITE enables eeprom 717 write routine for first time initialisation. 718 719 CONFIG_TULIP 720 Support for Digital 2114x chips. 721 Optional CONFIG_TULIP_SELECT_MEDIA for board specific 722 modem chip initialisation (KS8761/QS6611). 723 724 CONFIG_NATSEMI 725 Support for National dp83815 chips. 726 727 CONFIG_NS8382X 728 Support for National dp8382[01] gigabit chips. 729 730- NETWORK Support (other): 731 732 CONFIG_DRIVER_LAN91C96 733 Support for SMSC's LAN91C96 chips. 734 735 CONFIG_LAN91C96_BASE 736 Define this to hold the physical address 737 of the LAN91C96's I/O space 738 739 CONFIG_LAN91C96_USE_32_BIT 740 Define this to enable 32 bit addressing 741 742- USB Support: 743 At the moment only the UHCI host controller is 744 supported (PIP405, MIP405, MPC5200); define 745 CONFIG_USB_UHCI to enable it. 746 define CONFIG_USB_KEYBOARD to enable the USB Keyboard 747 end define CONFIG_USB_STORAGE to enable the USB 748 storage devices. 749 Note: 750 Supported are USB Keyboards and USB Floppy drives 751 (TEAC FD-05PUB). 752 MPC5200 USB requires additional defines: 753 CONFIG_USB_CLOCK 754 for 528 MHz Clock: 0x0001bbbb 755 CONFIG_USB_CONFIG 756 for differential drivers: 0x00001000 757 for single ended drivers: 0x00005000 758 759 760- MMC Support: 761 The MMC controller on the Intel PXA is supported. To 762 enable this define CONFIG_MMC. The MMC can be 763 accessed from the boot prompt by mapping the device 764 to physical memory similar to flash. Command line is 765 enabled with CFG_CMD_MMC. The MMC driver also works with 766 the FAT fs. This is enabled with CFG_CMD_FAT. 767 768- Keyboard Support: 769 CONFIG_ISA_KEYBOARD 770 771 Define this to enable standard (PC-Style) keyboard 772 support 773 774 CONFIG_I8042_KBD 775 Standard PC keyboard driver with US (is default) and 776 GERMAN key layout (switch via environment 'keymap=de') support. 777 Export function i8042_kbd_init, i8042_tstc and i8042_getc 778 for cfb_console. Supports cursor blinking. 779 780- Video support: 781 CONFIG_VIDEO 782 783 Define this to enable video support (for output to 784 video). 785 786 CONFIG_VIDEO_CT69000 787 788 Enable Chips & Technologies 69000 Video chip 789 790 CONFIG_VIDEO_SMI_LYNXEM 791 Enable Silicon Motion SMI 712/710/810 Video chip. The 792 video output is selected via environment 'videoout' 793 (1 = LCD and 2 = CRT). If videoout is undefined, CRT is 794 assumed. 795 796 For the CT69000 and SMI_LYNXEM drivers, videomode is 797 selected via environment 'videomode'. Two diferent ways 798 are possible: 799 - "videomode=num" 'num' is a standard LiLo mode numbers. 800 Following standard modes are supported (* is default): 801 802 Colors 640x480 800x600 1024x768 1152x864 1280x1024 803 -------------+--------------------------------------------- 804 8 bits | 0x301* 0x303 0x305 0x161 0x307 805 15 bits | 0x310 0x313 0x316 0x162 0x319 806 16 bits | 0x311 0x314 0x317 0x163 0x31A 807 24 bits | 0x312 0x315 0x318 ? 0x31B 808 -------------+--------------------------------------------- 809 (i.e. setenv videomode 317; saveenv; reset;) 810 811 - "videomode=bootargs" all the video parameters are parsed 812 from the bootargs. (See drivers/videomodes.c) 813 814 815 CONFIG_VIDEO_SED13806 816 Enable Epson SED13806 driver. This driver supports 8bpp 817 and 16bpp modes defined by CONFIG_VIDEO_SED13806_8BPP 818 or CONFIG_VIDEO_SED13806_16BPP 819 820- Keyboard Support: 821 CONFIG_KEYBOARD 822 823 Define this to enable a custom keyboard support. 824 This simply calls drv_keyboard_init() which must be 825 defined in your board-specific files. 826 The only board using this so far is RBC823. 827 828- LCD Support: CONFIG_LCD 829 830 Define this to enable LCD support (for output to LCD 831 display); also select one of the supported displays 832 by defining one of these: 833 834 CONFIG_NEC_NL6448AC33: 835 836 NEC NL6448AC33-18. Active, color, single scan. 837 838 CONFIG_NEC_NL6448BC20 839 840 NEC NL6448BC20-08. 6.5", 640x480. 841 Active, color, single scan. 842 843 CONFIG_NEC_NL6448BC33_54 844 845 NEC NL6448BC33-54. 10.4", 640x480. 846 Active, color, single scan. 847 848 CONFIG_SHARP_16x9 849 850 Sharp 320x240. Active, color, single scan. 851 It isn't 16x9, and I am not sure what it is. 852 853 CONFIG_SHARP_LQ64D341 854 855 Sharp LQ64D341 display, 640x480. 856 Active, color, single scan. 857 858 CONFIG_HLD1045 859 860 HLD1045 display, 640x480. 861 Active, color, single scan. 862 863 CONFIG_OPTREX_BW 864 865 Optrex CBL50840-2 NF-FW 99 22 M5 866 or 867 Hitachi LMG6912RPFC-00T 868 or 869 Hitachi SP14Q002 870 871 320x240. Black & white. 872 873 Normally display is black on white background; define 874 CFG_WHITE_ON_BLACK to get it inverted. 875 876- Splash Screen Support: CONFIG_SPLASH_SCREEN 877 878 If this option is set, the environment is checked for 879 a variable "splashimage". If found, the usual display 880 of logo, copyright and system information on the LCD 881 is supressed and the BMP image at the address 882 specified in "splashimage" is loaded instead. The 883 console is redirected to the "nulldev", too. This 884 allows for a "silent" boot where a splash screen is 885 loaded very quickly after power-on. 886 887- Compression support: 888 CONFIG_BZIP2 889 890 If this option is set, support for bzip2 compressed 891 images is included. If not, only uncompressed and gzip 892 compressed images are supported. 893 894 NOTE: the bzip2 algorithm requires a lot of RAM, so 895 the malloc area (as defined by CFG_MALLOC_LEN) should 896 be at least 4MB. 897 898- Ethernet address: 899 CONFIG_ETHADDR 900 CONFIG_ETH2ADDR 901 CONFIG_ETH3ADDR 902 903 Define a default value for ethernet address to use 904 for the respective ethernet interface, in case this 905 is not determined automatically. 906 907- IP address: 908 CONFIG_IPADDR 909 910 Define a default value for the IP address to use for 911 the default ethernet interface, in case this is not 912 determined through e.g. bootp. 913 914- Server IP address: 915 CONFIG_SERVERIP 916 917 Defines a default value for theIP address of a TFTP 918 server to contact when using the "tftboot" command. 919 920- BOOTP Recovery Mode: 921 CONFIG_BOOTP_RANDOM_DELAY 922 923 If you have many targets in a network that try to 924 boot using BOOTP, you may want to avoid that all 925 systems send out BOOTP requests at precisely the same 926 moment (which would happen for instance at recovery 927 from a power failure, when all systems will try to 928 boot, thus flooding the BOOTP server. Defining 929 CONFIG_BOOTP_RANDOM_DELAY causes a random delay to be 930 inserted before sending out BOOTP requests. The 931 following delays are insterted then: 932 933 1st BOOTP request: delay 0 ... 1 sec 934 2nd BOOTP request: delay 0 ... 2 sec 935 3rd BOOTP request: delay 0 ... 4 sec 936 4th and following 937 BOOTP requests: delay 0 ... 8 sec 938 939- DHCP Advanced Options: 940 CONFIG_BOOTP_MASK 941 942 You can fine tune the DHCP functionality by adding 943 these flags to the CONFIG_BOOTP_MASK define: 944 945 CONFIG_BOOTP_DNS2 - If a DHCP client requests the DNS 946 serverip from a DHCP server, it is possible that more 947 than one DNS serverip is offered to the client. 948 If CONFIG_BOOTP_DNS2 is enabled, the secondary DNS 949 serverip will be stored in the additional environment 950 variable "dnsip2". The first DNS serverip is always 951 stored in the variable "dnsip", when CONFIG_BOOTP_DNS 952 is added to the CONFIG_BOOTP_MASK. 953 954 CONFIG_BOOTP_SEND_HOSTNAME - Some DHCP servers are capable 955 to do a dynamic update of a DNS server. To do this, they 956 need the hostname of the DHCP requester. 957 If CONFIG_BOOP_SEND_HOSTNAME is added to the 958 CONFIG_BOOTP_MASK, the content of the "hostname" 959 environment variable is passed as option 12 to 960 the DHCP server. 961 962 - CDP Options: 963 CONFIG_CDP_DEVICE_ID 964 965 The device id used in CDP trigger frames. 966 967 CONFIG_CDP_DEVICE_ID_PREFIX 968 969 A two character string which is prefixed to the MAC address 970 of the device. 971 972 CONFIG_CDP_PORT_ID 973 974 A printf format string which contains the ascii name of 975 the port. Normally is set to "eth%d" which sets 976 eth0 for the first ethernet, eth1 for the second etc. 977 978 CONFIG_CDP_CAPABILITIES 979 980 A 32bit integer which indicates the device capabilities; 981 0x00000010 for a normal host which does not forwards. 982 983 CONFIG_CDP_VERSION 984 985 An ascii string containing the version of the software. 986 987 CONFIG_CDP_PLATFORM 988 989 An ascii string containing the name of the platform. 990 991 CONFIG_CDP_TRIGGER 992 993 A 32bit integer sent on the trigger. 994 995 CONFIG_CDP_POWER_CONSUMPTION 996 997 A 16bit integer containing the power consumption of the 998 device in .1 of milliwatts. 999 1000 CONFIG_CDP_APPLIANCE_VLAN_TYPE 1001 1002 A byte containing the id of the VLAN. 1003 1004- Status LED: CONFIG_STATUS_LED 1005 1006 Several configurations allow to display the current 1007 status using a LED. For instance, the LED will blink 1008 fast while running U-Boot code, stop blinking as 1009 soon as a reply to a BOOTP request was received, and 1010 start blinking slow once the Linux kernel is running 1011 (supported by a status LED driver in the Linux 1012 kernel). Defining CONFIG_STATUS_LED enables this 1013 feature in U-Boot. 1014 1015- CAN Support: CONFIG_CAN_DRIVER 1016 1017 Defining CONFIG_CAN_DRIVER enables CAN driver support 1018 on those systems that support this (optional) 1019 feature, like the TQM8xxL modules. 1020 1021- I2C Support: CONFIG_HARD_I2C | CONFIG_SOFT_I2C 1022 1023 These enable I2C serial bus commands. Defining either of 1024 (but not both of) CONFIG_HARD_I2C or CONFIG_SOFT_I2C will 1025 include the appropriate I2C driver for the selected cpu. 1026 1027 This will allow you to use i2c commands at the u-boot 1028 command line (as long as you set CFG_CMD_I2C in 1029 CONFIG_COMMANDS) and communicate with i2c based realtime 1030 clock chips. See common/cmd_i2c.c for a description of the 1031 command line interface. 1032 1033 CONFIG_HARD_I2C selects the CPM hardware driver for I2C. 1034 1035 CONFIG_SOFT_I2C configures u-boot to use a software (aka 1036 bit-banging) driver instead of CPM or similar hardware 1037 support for I2C. 1038 1039 There are several other quantities that must also be 1040 defined when you define CONFIG_HARD_I2C or CONFIG_SOFT_I2C. 1041 1042 In both cases you will need to define CFG_I2C_SPEED 1043 to be the frequency (in Hz) at which you wish your i2c bus 1044 to run and CFG_I2C_SLAVE to be the address of this node (ie 1045 the cpu's i2c node address). 1046 1047 Now, the u-boot i2c code for the mpc8xx (cpu/mpc8xx/i2c.c) 1048 sets the cpu up as a master node and so its address should 1049 therefore be cleared to 0 (See, eg, MPC823e User's Manual 1050 p.16-473). So, set CFG_I2C_SLAVE to 0. 1051 1052 That's all that's required for CONFIG_HARD_I2C. 1053 1054 If you use the software i2c interface (CONFIG_SOFT_I2C) 1055 then the following macros need to be defined (examples are 1056 from include/configs/lwmon.h): 1057 1058 I2C_INIT 1059 1060 (Optional). Any commands necessary to enable the I2C 1061 controller or configure ports. 1062 1063 eg: #define I2C_INIT (immr->im_cpm.cp_pbdir |= PB_SCL) 1064 1065 I2C_PORT 1066 1067 (Only for MPC8260 CPU). The I/O port to use (the code 1068 assumes both bits are on the same port). Valid values 1069 are 0..3 for ports A..D. 1070 1071 I2C_ACTIVE 1072 1073 The code necessary to make the I2C data line active 1074 (driven). If the data line is open collector, this 1075 define can be null. 1076 1077 eg: #define I2C_ACTIVE (immr->im_cpm.cp_pbdir |= PB_SDA) 1078 1079 I2C_TRISTATE 1080 1081 The code necessary to make the I2C data line tri-stated 1082 (inactive). If the data line is open collector, this 1083 define can be null. 1084 1085 eg: #define I2C_TRISTATE (immr->im_cpm.cp_pbdir &= ~PB_SDA) 1086 1087 I2C_READ 1088 1089 Code that returns TRUE if the I2C data line is high, 1090 FALSE if it is low. 1091 1092 eg: #define I2C_READ ((immr->im_cpm.cp_pbdat & PB_SDA) != 0) 1093 1094 I2C_SDA(bit) 1095 1096 If <bit> is TRUE, sets the I2C data line high. If it 1097 is FALSE, it clears it (low). 1098 1099 eg: #define I2C_SDA(bit) \ 1100 if(bit) immr->im_cpm.cp_pbdat |= PB_SDA; \ 1101 else immr->im_cpm.cp_pbdat &= ~PB_SDA 1102 1103 I2C_SCL(bit) 1104 1105 If <bit> is TRUE, sets the I2C clock line high. If it 1106 is FALSE, it clears it (low). 1107 1108 eg: #define I2C_SCL(bit) \ 1109 if(bit) immr->im_cpm.cp_pbdat |= PB_SCL; \ 1110 else immr->im_cpm.cp_pbdat &= ~PB_SCL 1111 1112 I2C_DELAY 1113 1114 This delay is invoked four times per clock cycle so this 1115 controls the rate of data transfer. The data rate thus 1116 is 1 / (I2C_DELAY * 4). Often defined to be something 1117 like: 1118 1119 #define I2C_DELAY udelay(2) 1120 1121 CFG_I2C_INIT_BOARD 1122 1123 When a board is reset during an i2c bus transfer 1124 chips might think that the current transfer is still 1125 in progress. On some boards it is possible to access 1126 the i2c SCLK line directly, either by using the 1127 processor pin as a GPIO or by having a second pin 1128 connected to the bus. If this option is defined a 1129 custom i2c_init_board() routine in boards/xxx/board.c 1130 is run early in the boot sequence. 1131 1132- SPI Support: CONFIG_SPI 1133 1134 Enables SPI driver (so far only tested with 1135 SPI EEPROM, also an instance works with Crystal A/D and 1136 D/As on the SACSng board) 1137 1138 CONFIG_SPI_X 1139 1140 Enables extended (16-bit) SPI EEPROM addressing. 1141 (symmetrical to CONFIG_I2C_X) 1142 1143 CONFIG_SOFT_SPI 1144 1145 Enables a software (bit-bang) SPI driver rather than 1146 using hardware support. This is a general purpose 1147 driver that only requires three general I/O port pins 1148 (two outputs, one input) to function. If this is 1149 defined, the board configuration must define several 1150 SPI configuration items (port pins to use, etc). For 1151 an example, see include/configs/sacsng.h. 1152 1153- FPGA Support: CONFIG_FPGA_COUNT 1154 1155 Specify the number of FPGA devices to support. 1156 1157 CONFIG_FPGA 1158 1159 Used to specify the types of FPGA devices. For example, 1160 #define CONFIG_FPGA CFG_XILINX_VIRTEX2 1161 1162 CFG_FPGA_PROG_FEEDBACK 1163 1164 Enable printing of hash marks during FPGA configuration. 1165 1166 CFG_FPGA_CHECK_BUSY 1167 1168 Enable checks on FPGA configuration interface busy 1169 status by the configuration function. This option 1170 will require a board or device specific function to 1171 be written. 1172 1173 CONFIG_FPGA_DELAY 1174 1175 If defined, a function that provides delays in the FPGA 1176 configuration driver. 1177 1178 CFG_FPGA_CHECK_CTRLC 1179 Allow Control-C to interrupt FPGA configuration 1180 1181 CFG_FPGA_CHECK_ERROR 1182 1183 Check for configuration errors during FPGA bitfile 1184 loading. For example, abort during Virtex II 1185 configuration if the INIT_B line goes low (which 1186 indicated a CRC error). 1187 1188 CFG_FPGA_WAIT_INIT 1189 1190 Maximum time to wait for the INIT_B line to deassert 1191 after PROB_B has been deasserted during a Virtex II 1192 FPGA configuration sequence. The default time is 500 1193 mS. 1194 1195 CFG_FPGA_WAIT_BUSY 1196 1197 Maximum time to wait for BUSY to deassert during 1198 Virtex II FPGA configuration. The default is 5 mS. 1199 1200 CFG_FPGA_WAIT_CONFIG 1201 1202 Time to wait after FPGA configuration. The default is 1203 200 mS. 1204 1205- Configuration Management: 1206 CONFIG_IDENT_STRING 1207 1208 If defined, this string will be added to the U-Boot 1209 version information (U_BOOT_VERSION) 1210 1211- Vendor Parameter Protection: 1212 1213 U-Boot considers the values of the environment 1214 variables "serial#" (Board Serial Number) and 1215 "ethaddr" (Ethernet Address) to be parameters that 1216 are set once by the board vendor / manufacturer, and 1217 protects these variables from casual modification by 1218 the user. Once set, these variables are read-only, 1219 and write or delete attempts are rejected. You can 1220 change this behviour: 1221 1222 If CONFIG_ENV_OVERWRITE is #defined in your config 1223 file, the write protection for vendor parameters is 1224 completely disabled. Anybody can change or delete 1225 these parameters. 1226 1227 Alternatively, if you #define _both_ CONFIG_ETHADDR 1228 _and_ CONFIG_OVERWRITE_ETHADDR_ONCE, a default 1229 ethernet address is installed in the environment, 1230 which can be changed exactly ONCE by the user. [The 1231 serial# is unaffected by this, i. e. it remains 1232 read-only.] 1233 1234- Protected RAM: 1235 CONFIG_PRAM 1236 1237 Define this variable to enable the reservation of 1238 "protected RAM", i. e. RAM which is not overwritten 1239 by U-Boot. Define CONFIG_PRAM to hold the number of 1240 kB you want to reserve for pRAM. You can overwrite 1241 this default value by defining an environment 1242 variable "pram" to the number of kB you want to 1243 reserve. Note that the board info structure will 1244 still show the full amount of RAM. If pRAM is 1245 reserved, a new environment variable "mem" will 1246 automatically be defined to hold the amount of 1247 remaining RAM in a form that can be passed as boot 1248 argument to Linux, for instance like that: 1249 1250 setenv bootargs ... mem=\$(mem) 1251 saveenv 1252 1253 This way you can tell Linux not to use this memory, 1254 either, which results in a memory region that will 1255 not be affected by reboots. 1256 1257 *WARNING* If your board configuration uses automatic 1258 detection of the RAM size, you must make sure that 1259 this memory test is non-destructive. So far, the 1260 following board configurations are known to be 1261 "pRAM-clean": 1262 1263 ETX094, IVMS8, IVML24, SPD8xx, TQM8xxL, 1264 HERMES, IP860, RPXlite, LWMON, LANTEC, 1265 PCU_E, FLAGADM, TQM8260 1266 1267- Error Recovery: 1268 CONFIG_PANIC_HANG 1269 1270 Define this variable to stop the system in case of a 1271 fatal error, so that you have to reset it manually. 1272 This is probably NOT a good idea for an embedded 1273 system where you want to system to reboot 1274 automatically as fast as possible, but it may be 1275 useful during development since you can try to debug 1276 the conditions that lead to the situation. 1277 1278 CONFIG_NET_RETRY_COUNT 1279 1280 This variable defines the number of retries for 1281 network operations like ARP, RARP, TFTP, or BOOTP 1282 before giving up the operation. If not defined, a 1283 default value of 5 is used. 1284 1285- Command Interpreter: 1286 CFG_AUTO_COMPLETE 1287 1288 Enable auto completion of commands using TAB. 1289 1290 CFG_HUSH_PARSER 1291 1292 Define this variable to enable the "hush" shell (from 1293 Busybox) as command line interpreter, thus enabling 1294 powerful command line syntax like 1295 if...then...else...fi conditionals or `&&' and '||' 1296 constructs ("shell scripts"). 1297 1298 If undefined, you get the old, much simpler behaviour 1299 with a somewhat smaller memory footprint. 1300 1301 1302 CFG_PROMPT_HUSH_PS2 1303 1304 This defines the secondary prompt string, which is 1305 printed when the command interpreter needs more input 1306 to complete a command. Usually "> ". 1307 1308 Note: 1309 1310 In the current implementation, the local variables 1311 space and global environment variables space are 1312 separated. Local variables are those you define by 1313 simply typing `name=value'. To access a local 1314 variable later on, you have write `$name' or 1315 `${name}'; to execute the contents of a variable 1316 directly type `$name' at the command prompt. 1317 1318 Global environment variables are those you use 1319 setenv/printenv to work with. To run a command stored 1320 in such a variable, you need to use the run command, 1321 and you must not use the '$' sign to access them. 1322 1323 To store commands and special characters in a 1324 variable, please use double quotation marks 1325 surrounding the whole text of the variable, instead 1326 of the backslashes before semicolons and special 1327 symbols. 1328 1329- Default Environment: 1330 CONFIG_EXTRA_ENV_SETTINGS 1331 1332 Define this to contain any number of null terminated 1333 strings (variable = value pairs) that will be part of 1334 the default environment compiled into the boot image. 1335 1336 For example, place something like this in your 1337 board's config file: 1338 1339 #define CONFIG_EXTRA_ENV_SETTINGS \ 1340 "myvar1=value1\0" \ 1341 "myvar2=value2\0" 1342 1343 Warning: This method is based on knowledge about the 1344 internal format how the environment is stored by the 1345 U-Boot code. This is NOT an official, exported 1346 interface! Although it is unlikely that this format 1347 will change soon, there is no guarantee either. 1348 You better know what you are doing here. 1349 1350 Note: overly (ab)use of the default environment is 1351 discouraged. Make sure to check other ways to preset 1352 the environment like the autoscript function or the 1353 boot command first. 1354 1355- DataFlash Support: 1356 CONFIG_HAS_DATAFLASH 1357 1358 Defining this option enables DataFlash features and 1359 allows to read/write in Dataflash via the standard 1360 commands cp, md... 1361 1362- SystemACE Support: 1363 CONFIG_SYSTEMACE 1364 1365 Adding this option adds support for Xilinx SystemACE 1366 chips attached via some sort of local bus. The address 1367 of the chip must alsh be defined in the 1368 CFG_SYSTEMACE_BASE macro. For example: 1369 1370 #define CONFIG_SYSTEMACE 1371 #define CFG_SYSTEMACE_BASE 0xf0000000 1372 1373 When SystemACE support is added, the "ace" device type 1374 becomes available to the fat commands, i.e. fatls. 1375 1376- Show boot progress: 1377 CONFIG_SHOW_BOOT_PROGRESS 1378 1379 Defining this option allows to add some board- 1380 specific code (calling a user-provided function 1381 "show_boot_progress(int)") that enables you to show 1382 the system's boot progress on some display (for 1383 example, some LED's) on your board. At the moment, 1384 the following checkpoints are implemented: 1385 1386 Arg Where When 1387 1 common/cmd_bootm.c before attempting to boot an image 1388 -1 common/cmd_bootm.c Image header has bad magic number 1389 2 common/cmd_bootm.c Image header has correct magic number 1390 -2 common/cmd_bootm.c Image header has bad checksum 1391 3 common/cmd_bootm.c Image header has correct checksum 1392 -3 common/cmd_bootm.c Image data has bad checksum 1393 4 common/cmd_bootm.c Image data has correct checksum 1394 -4 common/cmd_bootm.c Image is for unsupported architecture 1395 5 common/cmd_bootm.c Architecture check OK 1396 -5 common/cmd_bootm.c Wrong Image Type (not kernel, multi, standalone) 1397 6 common/cmd_bootm.c Image Type check OK 1398 -6 common/cmd_bootm.c gunzip uncompression error 1399 -7 common/cmd_bootm.c Unimplemented compression type 1400 7 common/cmd_bootm.c Uncompression OK 1401 -8 common/cmd_bootm.c Wrong Image Type (not kernel, multi, standalone) 1402 8 common/cmd_bootm.c Image Type check OK 1403 -9 common/cmd_bootm.c Unsupported OS (not Linux, BSD, VxWorks, QNX) 1404 9 common/cmd_bootm.c Start initial ramdisk verification 1405 -10 common/cmd_bootm.c Ramdisk header has bad magic number 1406 -11 common/cmd_bootm.c Ramdisk header has bad checksum 1407 10 common/cmd_bootm.c Ramdisk header is OK 1408 -12 common/cmd_bootm.c Ramdisk data has bad checksum 1409 11 common/cmd_bootm.c Ramdisk data has correct checksum 1410 12 common/cmd_bootm.c Ramdisk verification complete, start loading 1411 -13 common/cmd_bootm.c Wrong Image Type (not PPC Linux Ramdisk) 1412 13 common/cmd_bootm.c Start multifile image verification 1413 14 common/cmd_bootm.c No initial ramdisk, no multifile, continue. 1414 15 common/cmd_bootm.c All preparation done, transferring control to OS 1415 1416 -30 lib_ppc/board.c Fatal error, hang the system 1417 -31 post/post.c POST test failed, detected by post_output_backlog() 1418 -32 post/post.c POST test failed, detected by post_run_single() 1419 1420 -1 common/cmd_doc.c Bad usage of "doc" command 1421 -1 common/cmd_doc.c No boot device 1422 -1 common/cmd_doc.c Unknown Chip ID on boot device 1423 -1 common/cmd_doc.c Read Error on boot device 1424 -1 common/cmd_doc.c Image header has bad magic number 1425 1426 -1 common/cmd_ide.c Bad usage of "ide" command 1427 -1 common/cmd_ide.c No boot device 1428 -1 common/cmd_ide.c Unknown boot device 1429 -1 common/cmd_ide.c Unknown partition table 1430 -1 common/cmd_ide.c Invalid partition type 1431 -1 common/cmd_ide.c Read Error on boot device 1432 -1 common/cmd_ide.c Image header has bad magic number 1433 1434 -1 common/cmd_nand.c Bad usage of "nand" command 1435 -1 common/cmd_nand.c No boot device 1436 -1 common/cmd_nand.c Unknown Chip ID on boot device 1437 -1 common/cmd_nand.c Read Error on boot device 1438 -1 common/cmd_nand.c Image header has bad magic number 1439 1440 -1 common/env_common.c Environment has a bad CRC, using default 1441 1442 1443Modem Support: 1444-------------- 1445 1446[so far only for SMDK2400 and TRAB boards] 1447 1448- Modem support endable: 1449 CONFIG_MODEM_SUPPORT 1450 1451- RTS/CTS Flow control enable: 1452 CONFIG_HWFLOW 1453 1454- Modem debug support: 1455 CONFIG_MODEM_SUPPORT_DEBUG 1456 1457 Enables debugging stuff (char screen[1024], dbg()) 1458 for modem support. Useful only with BDI2000. 1459 1460- Interrupt support (PPC): 1461 1462 There are common interrupt_init() and timer_interrupt() 1463 for all PPC archs. interrupt_init() calls interrupt_init_cpu() 1464 for cpu specific initialization. interrupt_init_cpu() 1465 should set decrementer_count to appropriate value. If 1466 cpu resets decrementer automatically after interrupt 1467 (ppc4xx) it should set decrementer_count to zero. 1468 timer_interrupt() calls timer_interrupt_cpu() for cpu 1469 specific handling. If board has watchdog / status_led 1470 / other_activity_monitor it works automatically from 1471 general timer_interrupt(). 1472 1473- General: 1474 1475 In the target system modem support is enabled when a 1476 specific key (key combination) is pressed during 1477 power-on. Otherwise U-Boot will boot normally 1478 (autoboot). The key_pressed() fuction is called from 1479 board_init(). Currently key_pressed() is a dummy 1480 function, returning 1 and thus enabling modem 1481 initialization. 1482 1483 If there are no modem init strings in the 1484 environment, U-Boot proceed to autoboot; the 1485 previous output (banner, info printfs) will be 1486 supressed, though. 1487 1488 See also: doc/README.Modem 1489 1490 1491Configuration Settings: 1492----------------------- 1493 1494- CFG_LONGHELP: Defined when you want long help messages included; 1495 undefine this when you're short of memory. 1496 1497- CFG_PROMPT: This is what U-Boot prints on the console to 1498 prompt for user input. 1499 1500- CFG_CBSIZE: Buffer size for input from the Console 1501 1502- CFG_PBSIZE: Buffer size for Console output 1503 1504- CFG_MAXARGS: max. Number of arguments accepted for monitor commands 1505 1506- CFG_BARGSIZE: Buffer size for Boot Arguments which are passed to 1507 the application (usually a Linux kernel) when it is 1508 booted 1509 1510- CFG_BAUDRATE_TABLE: 1511 List of legal baudrate settings for this board. 1512 1513- CFG_CONSOLE_INFO_QUIET 1514 Suppress display of console information at boot. 1515 1516- CFG_CONSOLE_IS_IN_ENV 1517 If the board specific function 1518 extern int overwrite_console (void); 1519 returns 1, the stdin, stderr and stdout are switched to the 1520 serial port, else the settings in the environment are used. 1521 1522- CFG_CONSOLE_OVERWRITE_ROUTINE 1523 Enable the call to overwrite_console(). 1524 1525- CFG_CONSOLE_ENV_OVERWRITE 1526 Enable overwrite of previous console environment settings. 1527 1528- CFG_MEMTEST_START, CFG_MEMTEST_END: 1529 Begin and End addresses of the area used by the 1530 simple memory test. 1531 1532- CFG_ALT_MEMTEST: 1533 Enable an alternate, more extensive memory test. 1534 1535- CFG_MEMTEST_SCRATCH: 1536 Scratch address used by the alternate memory test 1537 You only need to set this if address zero isn't writeable 1538 1539- CFG_TFTP_LOADADDR: 1540 Default load address for network file downloads 1541 1542- CFG_LOADS_BAUD_CHANGE: 1543 Enable temporary baudrate change while serial download 1544 1545- CFG_SDRAM_BASE: 1546 Physical start address of SDRAM. _Must_ be 0 here. 1547 1548- CFG_MBIO_BASE: 1549 Physical start address of Motherboard I/O (if using a 1550 Cogent motherboard) 1551 1552- CFG_FLASH_BASE: 1553 Physical start address of Flash memory. 1554 1555- CFG_MONITOR_BASE: 1556 Physical start address of boot monitor code (set by 1557 make config files to be same as the text base address 1558 (TEXT_BASE) used when linking) - same as 1559 CFG_FLASH_BASE when booting from flash. 1560 1561- CFG_MONITOR_LEN: 1562 Size of memory reserved for monitor code, used to 1563 determine _at_compile_time_ (!) if the environment is 1564 embedded within the U-Boot image, or in a separate 1565 flash sector. 1566 1567- CFG_MALLOC_LEN: 1568 Size of DRAM reserved for malloc() use. 1569 1570- CFG_BOOTMAPSZ: 1571 Maximum size of memory mapped by the startup code of 1572 the Linux kernel; all data that must be processed by 1573 the Linux kernel (bd_info, boot arguments, eventually 1574 initrd image) must be put below this limit. 1575 1576- CFG_MAX_FLASH_BANKS: 1577 Max number of Flash memory banks 1578 1579- CFG_MAX_FLASH_SECT: 1580 Max number of sectors on a Flash chip 1581 1582- CFG_FLASH_ERASE_TOUT: 1583 Timeout for Flash erase operations (in ms) 1584 1585- CFG_FLASH_WRITE_TOUT: 1586 Timeout for Flash write operations (in ms) 1587 1588- CFG_FLASH_LOCK_TOUT 1589 Timeout for Flash set sector lock bit operation (in ms) 1590 1591- CFG_FLASH_UNLOCK_TOUT 1592 Timeout for Flash clear lock bits operation (in ms) 1593 1594- CFG_FLASH_PROTECTION 1595 If defined, hardware flash sectors protection is used 1596 instead of U-Boot software protection. 1597 1598- CFG_DIRECT_FLASH_TFTP: 1599 1600 Enable TFTP transfers directly to flash memory; 1601 without this option such a download has to be 1602 performed in two steps: (1) download to RAM, and (2) 1603 copy from RAM to flash. 1604 1605 The two-step approach is usually more reliable, since 1606 you can check if the download worked before you erase 1607 the flash, but in some situations (when sytem RAM is 1608 too limited to allow for a tempory copy of the 1609 downloaded image) this option may be very useful. 1610 1611- CFG_FLASH_CFI: 1612 Define if the flash driver uses extra elements in the 1613 common flash structure for storing flash geometry. 1614 1615- CFG_FLASH_CFI_DRIVER 1616 This option also enables the building of the cfi_flash driver 1617 in the drivers directory 1618 1619- CFG_RX_ETH_BUFFER: 1620 Defines the number of ethernet receive buffers. On some 1621 ethernet controllers it is recommended to set this value 1622 to 8 or even higher (EEPRO100 or 405 EMAC), since all 1623 buffers can be full shortly after enabling the interface 1624 on high ethernet traffic. 1625 Defaults to 4 if not defined. 1626 1627The following definitions that deal with the placement and management 1628of environment data (variable area); in general, we support the 1629following configurations: 1630 1631- CFG_ENV_IS_IN_FLASH: 1632 1633 Define this if the environment is in flash memory. 1634 1635 a) The environment occupies one whole flash sector, which is 1636 "embedded" in the text segment with the U-Boot code. This 1637 happens usually with "bottom boot sector" or "top boot 1638 sector" type flash chips, which have several smaller 1639 sectors at the start or the end. For instance, such a 1640 layout can have sector sizes of 8, 2x4, 16, Nx32 kB. In 1641 such a case you would place the environment in one of the 1642 4 kB sectors - with U-Boot code before and after it. With 1643 "top boot sector" type flash chips, you would put the 1644 environment in one of the last sectors, leaving a gap 1645 between U-Boot and the environment. 1646 1647 - CFG_ENV_OFFSET: 1648 1649 Offset of environment data (variable area) to the 1650 beginning of flash memory; for instance, with bottom boot 1651 type flash chips the second sector can be used: the offset 1652 for this sector is given here. 1653 1654 CFG_ENV_OFFSET is used relative to CFG_FLASH_BASE. 1655 1656 - CFG_ENV_ADDR: 1657 1658 This is just another way to specify the start address of 1659 the flash sector containing the environment (instead of 1660 CFG_ENV_OFFSET). 1661 1662 - CFG_ENV_SECT_SIZE: 1663 1664 Size of the sector containing the environment. 1665 1666 1667 b) Sometimes flash chips have few, equal sized, BIG sectors. 1668 In such a case you don't want to spend a whole sector for 1669 the environment. 1670 1671 - CFG_ENV_SIZE: 1672 1673 If you use this in combination with CFG_ENV_IS_IN_FLASH 1674 and CFG_ENV_SECT_SIZE, you can specify to use only a part 1675 of this flash sector for the environment. This saves 1676 memory for the RAM copy of the environment. 1677 1678 It may also save flash memory if you decide to use this 1679 when your environment is "embedded" within U-Boot code, 1680 since then the remainder of the flash sector could be used 1681 for U-Boot code. It should be pointed out that this is 1682 STRONGLY DISCOURAGED from a robustness point of view: 1683 updating the environment in flash makes it always 1684 necessary to erase the WHOLE sector. If something goes 1685 wrong before the contents has been restored from a copy in 1686 RAM, your target system will be dead. 1687 1688 - CFG_ENV_ADDR_REDUND 1689 CFG_ENV_SIZE_REDUND 1690 1691 These settings describe a second storage area used to hold 1692 a redundand copy of the environment data, so that there is 1693 a valid backup copy in case there is a power failure during 1694 a "saveenv" operation. 1695 1696BE CAREFUL! Any changes to the flash layout, and some changes to the 1697source code will make it necessary to adapt <board>/u-boot.lds* 1698accordingly! 1699 1700 1701- CFG_ENV_IS_IN_NVRAM: 1702 1703 Define this if you have some non-volatile memory device 1704 (NVRAM, battery buffered SRAM) which you want to use for the 1705 environment. 1706 1707 - CFG_ENV_ADDR: 1708 - CFG_ENV_SIZE: 1709 1710 These two #defines are used to determin the memory area you 1711 want to use for environment. It is assumed that this memory 1712 can just be read and written to, without any special 1713 provision. 1714 1715BE CAREFUL! The first access to the environment happens quite early 1716in U-Boot initalization (when we try to get the setting of for the 1717console baudrate). You *MUST* have mappend your NVRAM area then, or 1718U-Boot will hang. 1719 1720Please note that even with NVRAM we still use a copy of the 1721environment in RAM: we could work on NVRAM directly, but we want to 1722keep settings there always unmodified except somebody uses "saveenv" 1723to save the current settings. 1724 1725 1726- CFG_ENV_IS_IN_EEPROM: 1727 1728 Use this if you have an EEPROM or similar serial access 1729 device and a driver for it. 1730 1731 - CFG_ENV_OFFSET: 1732 - CFG_ENV_SIZE: 1733 1734 These two #defines specify the offset and size of the 1735 environment area within the total memory of your EEPROM. 1736 1737 - CFG_I2C_EEPROM_ADDR: 1738 If defined, specified the chip address of the EEPROM device. 1739 The default address is zero. 1740 1741 - CFG_EEPROM_PAGE_WRITE_BITS: 1742 If defined, the number of bits used to address bytes in a 1743 single page in the EEPROM device. A 64 byte page, for example 1744 would require six bits. 1745 1746 - CFG_EEPROM_PAGE_WRITE_DELAY_MS: 1747 If defined, the number of milliseconds to delay between 1748 page writes. The default is zero milliseconds. 1749 1750 - CFG_I2C_EEPROM_ADDR_LEN: 1751 The length in bytes of the EEPROM memory array address. Note 1752 that this is NOT the chip address length! 1753 1754 - CFG_I2C_EEPROM_ADDR_OVERFLOW: 1755 EEPROM chips that implement "address overflow" are ones 1756 like Catalyst 24WC04/08/16 which has 9/10/11 bits of 1757 address and the extra bits end up in the "chip address" bit 1758 slots. This makes a 24WC08 (1Kbyte) chip look like four 256 1759 byte chips. 1760 1761 Note that we consider the length of the address field to 1762 still be one byte because the extra address bits are hidden 1763 in the chip address. 1764 1765 - CFG_EEPROM_SIZE: 1766 The size in bytes of the EEPROM device. 1767 1768 1769- CFG_ENV_IS_IN_DATAFLASH: 1770 1771 Define this if you have a DataFlash memory device which you 1772 want to use for the environment. 1773 1774 - CFG_ENV_OFFSET: 1775 - CFG_ENV_ADDR: 1776 - CFG_ENV_SIZE: 1777 1778 These three #defines specify the offset and size of the 1779 environment area within the total memory of your DataFlash placed 1780 at the specified address. 1781 1782 1783- CFG_SPI_INIT_OFFSET 1784 1785 Defines offset to the initial SPI buffer area in DPRAM. The 1786 area is used at an early stage (ROM part) if the environment 1787 is configured to reside in the SPI EEPROM: We need a 520 byte 1788 scratch DPRAM area. It is used between the two initialization 1789 calls (spi_init_f() and spi_init_r()). A value of 0xB00 seems 1790 to be a good choice since it makes it far enough from the 1791 start of the data area as well as from the stack pointer. 1792 1793Please note that the environment is read-only as long as the monitor 1794has been relocated to RAM and a RAM copy of the environment has been 1795created; also, when using EEPROM you will have to use getenv_r() 1796until then to read environment variables. 1797 1798The environment is protected by a CRC32 checksum. Before the monitor 1799is relocated into RAM, as a result of a bad CRC you will be working 1800with the compiled-in default environment - *silently*!!! [This is 1801necessary, because the first environment variable we need is the 1802"baudrate" setting for the console - if we have a bad CRC, we don't 1803have any device yet where we could complain.] 1804 1805Note: once the monitor has been relocated, then it will complain if 1806the default environment is used; a new CRC is computed as soon as you 1807use the "saveenv" command to store a valid environment. 1808 1809- CFG_FAULT_ECHO_LINK_DOWN: 1810 Echo the inverted Ethernet link state to the fault LED. 1811 1812 Note: If this option is active, then CFG_FAULT_MII_ADDR 1813 also needs to be defined. 1814 1815- CFG_FAULT_MII_ADDR: 1816 MII address of the PHY to check for the Ethernet link state. 1817 1818- CFG_64BIT_VSPRINTF: 1819 Makes vsprintf (and all *printf functions) support printing 1820 of 64bit values by using the L quantifier 1821 1822- CFG_64BIT_STRTOUL: 1823 Adds simple_strtoull that returns a 64bit value 1824 1825Low Level (hardware related) configuration options: 1826--------------------------------------------------- 1827 1828- CFG_CACHELINE_SIZE: 1829 Cache Line Size of the CPU. 1830 1831- CFG_DEFAULT_IMMR: 1832 Default address of the IMMR after system reset. 1833 1834 Needed on some 8260 systems (MPC8260ADS, PQ2FADS-ZU, 1835 and RPXsuper) to be able to adjust the position of 1836 the IMMR register after a reset. 1837 1838- Floppy Disk Support: 1839 CFG_FDC_DRIVE_NUMBER 1840 1841 the default drive number (default value 0) 1842 1843 CFG_ISA_IO_STRIDE 1844 1845 defines the spacing between fdc chipset registers 1846 (default value 1) 1847 1848 CFG_ISA_IO_OFFSET 1849 1850 defines the offset of register from address. It 1851 depends on which part of the data bus is connected to 1852 the fdc chipset. (default value 0) 1853 1854 If CFG_ISA_IO_STRIDE CFG_ISA_IO_OFFSET and 1855 CFG_FDC_DRIVE_NUMBER are undefined, they take their 1856 default value. 1857 1858 if CFG_FDC_HW_INIT is defined, then the function 1859 fdc_hw_init() is called at the beginning of the FDC 1860 setup. fdc_hw_init() must be provided by the board 1861 source code. It is used to make hardware dependant 1862 initializations. 1863 1864- CFG_IMMR: Physical address of the Internal Memory Mapped 1865 Register; DO NOT CHANGE! (11-4) 1866 [MPC8xx systems only] 1867 1868- CFG_INIT_RAM_ADDR: 1869 1870 Start address of memory area that can be used for 1871 initial data and stack; please note that this must be 1872 writable memory that is working WITHOUT special 1873 initialization, i. e. you CANNOT use normal RAM which 1874 will become available only after programming the 1875 memory controller and running certain initialization 1876 sequences. 1877 1878 U-Boot uses the following memory types: 1879 - MPC8xx and MPC8260: IMMR (internal memory of the CPU) 1880 - MPC824X: data cache 1881 - PPC4xx: data cache 1882 1883- CFG_GBL_DATA_OFFSET: 1884 1885 Offset of the initial data structure in the memory 1886 area defined by CFG_INIT_RAM_ADDR. Usually 1887 CFG_GBL_DATA_OFFSET is chosen such that the initial 1888 data is located at the end of the available space 1889 (sometimes written as (CFG_INIT_RAM_END - 1890 CFG_INIT_DATA_SIZE), and the initial stack is just 1891 below that area (growing from (CFG_INIT_RAM_ADDR + 1892 CFG_GBL_DATA_OFFSET) downward. 1893 1894 Note: 1895 On the MPC824X (or other systems that use the data 1896 cache for initial memory) the address chosen for 1897 CFG_INIT_RAM_ADDR is basically arbitrary - it must 1898 point to an otherwise UNUSED address space between 1899 the top of RAM and the start of the PCI space. 1900 1901- CFG_SIUMCR: SIU Module Configuration (11-6) 1902 1903- CFG_SYPCR: System Protection Control (11-9) 1904 1905- CFG_TBSCR: Time Base Status and Control (11-26) 1906 1907- CFG_PISCR: Periodic Interrupt Status and Control (11-31) 1908 1909- CFG_PLPRCR: PLL, Low-Power, and Reset Control Register (15-30) 1910 1911- CFG_SCCR: System Clock and reset Control Register (15-27) 1912 1913- CFG_OR_TIMING_SDRAM: 1914 SDRAM timing 1915 1916- CFG_MAMR_PTA: 1917 periodic timer for refresh 1918 1919- CFG_DER: Debug Event Register (37-47) 1920 1921- FLASH_BASE0_PRELIM, FLASH_BASE1_PRELIM, CFG_REMAP_OR_AM, 1922 CFG_PRELIM_OR_AM, CFG_OR_TIMING_FLASH, CFG_OR0_REMAP, 1923 CFG_OR0_PRELIM, CFG_BR0_PRELIM, CFG_OR1_REMAP, CFG_OR1_PRELIM, 1924 CFG_BR1_PRELIM: 1925 Memory Controller Definitions: BR0/1 and OR0/1 (FLASH) 1926 1927- SDRAM_BASE2_PRELIM, SDRAM_BASE3_PRELIM, SDRAM_MAX_SIZE, 1928 CFG_OR_TIMING_SDRAM, CFG_OR2_PRELIM, CFG_BR2_PRELIM, 1929 CFG_OR3_PRELIM, CFG_BR3_PRELIM: 1930 Memory Controller Definitions: BR2/3 and OR2/3 (SDRAM) 1931 1932- CFG_MAMR_PTA, CFG_MPTPR_2BK_4K, CFG_MPTPR_1BK_4K, CFG_MPTPR_2BK_8K, 1933 CFG_MPTPR_1BK_8K, CFG_MAMR_8COL, CFG_MAMR_9COL: 1934 Machine Mode Register and Memory Periodic Timer 1935 Prescaler definitions (SDRAM timing) 1936 1937- CFG_I2C_UCODE_PATCH, CFG_I2C_DPMEM_OFFSET [0x1FC0]: 1938 enable I2C microcode relocation patch (MPC8xx); 1939 define relocation offset in DPRAM [DSP2] 1940 1941- CFG_SPI_UCODE_PATCH, CFG_SPI_DPMEM_OFFSET [0x1FC0]: 1942 enable SPI microcode relocation patch (MPC8xx); 1943 define relocation offset in DPRAM [SCC4] 1944 1945- CFG_USE_OSCCLK: 1946 Use OSCM clock mode on MBX8xx board. Be careful, 1947 wrong setting might damage your board. Read 1948 doc/README.MBX before setting this variable! 1949 1950- CFG_CPM_POST_WORD_ADDR: (MPC8xx, MPC8260 only) 1951 Offset of the bootmode word in DPRAM used by post 1952 (Power On Self Tests). This definition overrides 1953 #define'd default value in commproc.h resp. 1954 cpm_8260.h. 1955 1956- CFG_PCI_SLV_MEM_LOCAL, CFG_PCI_SLV_MEM_BUS, CFG_PICMR0_MASK_ATTRIB, 1957 CFG_PCI_MSTR0_LOCAL, CFG_PCIMSK0_MASK, CFG_PCI_MSTR1_LOCAL, 1958 CFG_PCIMSK1_MASK, CFG_PCI_MSTR_MEM_LOCAL, CFG_PCI_MSTR_MEM_BUS, 1959 CFG_CPU_PCI_MEM_START, CFG_PCI_MSTR_MEM_SIZE, CFG_POCMR0_MASK_ATTRIB, 1960 CFG_PCI_MSTR_MEMIO_LOCAL, CFG_PCI_MSTR_MEMIO_BUS, CPU_PCI_MEMIO_START, 1961 CFG_PCI_MSTR_MEMIO_SIZE, CFG_POCMR1_MASK_ATTRIB, CFG_PCI_MSTR_IO_LOCAL, 1962 CFG_PCI_MSTR_IO_BUS, CFG_CPU_PCI_IO_START, CFG_PCI_MSTR_IO_SIZE, 1963 CFG_POCMR2_MASK_ATTRIB: (MPC826x only) 1964 Overrides the default PCI memory map in cpu/mpc8260/pci.c if set. 1965 1966- CONFIG_ETHER_ON_FEC[12] 1967 Define to enable FEC[12] on a 8xx series processor. 1968 1969- CONFIG_FEC[12]_PHY 1970 Define to the hardcoded PHY address which corresponds 1971 to the given FEC; i. e. 1972 #define CONFIG_FEC1_PHY 4 1973 means that the PHY with address 4 is connected to FEC1 1974 1975 When set to -1, means to probe for first available. 1976 1977- CONFIG_FEC[12]_PHY_NORXERR 1978 The PHY does not have a RXERR line (RMII only). 1979 (so program the FEC to ignore it). 1980 1981- CONFIG_RMII 1982 Enable RMII mode for all FECs. 1983 Note that this is a global option, we can't 1984 have one FEC in standard MII mode and another in RMII mode. 1985 1986- CONFIG_CRC32_VERIFY 1987 Add a verify option to the crc32 command. 1988 The syntax is: 1989 1990 => crc32 -v <address> <count> <crc32> 1991 1992 Where address/count indicate a memory area 1993 and crc32 is the correct crc32 which the 1994 area should have. 1995 1996Building the Software: 1997====================== 1998 1999Building U-Boot has been tested in native PPC environments (on a 2000PowerBook G3 running LinuxPPC 2000) and in cross environments 2001(running RedHat 6.x and 7.x Linux on x86, Solaris 2.6 on a SPARC, and 2002NetBSD 1.5 on x86). 2003 2004If you are not using a native PPC environment, it is assumed that you 2005have the GNU cross compiling tools available in your path and named 2006with a prefix of "powerpc-linux-". If this is not the case, (e.g. if 2007you are using Monta Vista's Hard Hat Linux CDK 1.2) you must change 2008the definition of CROSS_COMPILE in Makefile. For HHL on a 4xx CPU, 2009change it to: 2010 2011 CROSS_COMPILE = ppc_4xx- 2012 2013 2014U-Boot is intended to be simple to build. After installing the 2015sources you must configure U-Boot for one specific board type. This 2016is done by typing: 2017 2018 make NAME_config 2019 2020where "NAME_config" is the name of one of the existing 2021configurations; the following names are supported: 2022 2023 ADCIOP_config ADS860_config AR405_config 2024 at91rm9200dk_config CANBT_config cmi_mpc5xx_config 2025 cogent_common_config cogent_mpc8260_config cogent_mpc8xx_config 2026 CPCI405_config CPCIISER4_config CU824_config 2027 DUET_ADS_config EBONY_config ELPT860_config 2028 ESTEEM192E_config ETX094_config FADS823_config 2029 FADS850SAR_config FADS860T_config FPS850L_config 2030 FPS860L_config GEN860T_config GENIETV_config 2031 GTH_config hermes_config hymod_config 2032 IP860_config IVML24_config IVMS8_config 2033 JSE_config LANTEC_config lwmon_config 2034 MBX860T_config MBX_config MPC8260ADS_config 2035 MPC8540ADS_config MPC8560ADS_config NETVIA_config 2036 omap1510inn_config omap1610h2_config omap1610inn_config 2037 pcu_e_config PIP405_config QS823_config 2038 QS850_config QS860T_config RPXlite_config 2039 RPXsuper_config rsdproto_config Sandpoint8240_config 2040 sbc8260_config SM850_config SPD823TS_config 2041 stxgp3_config SXNI855T_config TQM823L_config 2042 TQM850L_config TQM855L_config TQM860L_config 2043 WALNUT405_config ZPC1900_config 2044 2045 Note: for some board special configuration names may exist; check if 2046 additional information is available from the board vendor; for 2047 instance, the TQM8xxL systems run normally at 50 MHz and use a 2048 SCC for 10baseT ethernet; there are also systems with 80 MHz 2049 CPU clock, and an optional Fast Ethernet module is available 2050 for CPU's with FEC. You can select such additional "features" 2051 when chosing the configuration, i. e. 2052 2053 make TQM860L_config 2054 - will configure for a plain TQM860L, i. e. 50MHz, no FEC 2055 2056 make TQM860L_FEC_config 2057 - will configure for a TQM860L at 50MHz with FEC for ethernet 2058 2059 make TQM860L_80MHz_config 2060 - will configure for a TQM860L at 80 MHz, with normal 10baseT 2061 interface 2062 2063 make TQM860L_FEC_80MHz_config 2064 - will configure for a TQM860L at 80 MHz with FEC for ethernet 2065 2066 make TQM823L_LCD_config 2067 - will configure for a TQM823L with U-Boot console on LCD 2068 2069 make TQM823L_LCD_80MHz_config 2070 - will configure for a TQM823L at 80 MHz with U-Boot console on LCD 2071 2072 etc. 2073 2074 2075 Finally, type "make all", and you should get some working U-Boot 2076 images ready for download to / installation on your system: 2077 2078 - "u-boot.bin" is a raw binary image 2079 - "u-boot" is an image in ELF binary format 2080 - "u-boot.srec" is in Motorola S-Record format 2081 2082 2083 Please be aware that the Makefiles assume you are using GNU make, so 2084 for instance on NetBSD you might need to use "gmake" instead of 2085 native "make". 2086 2087 2088 If the system board that you have is not listed, then you will need 2089 to port U-Boot to your hardware platform. To do this, follow these 2090 steps: 2091 2092 1. Add a new configuration option for your board to the toplevel 2093 "Makefile" and to the "MAKEALL" script, using the existing 2094 entries as examples. Note that here and at many other places 2095 boards and other names are listed in alphabetical sort order. Please 2096 keep this order. 2097 2. Create a new directory to hold your board specific code. Add any 2098 files you need. In your board directory, you will need at least 2099 the "Makefile", a "<board>.c", "flash.c" and "u-boot.lds". 2100 3. Create a new configuration file "include/configs/<board>.h" for 2101 your board 2102 3. If you're porting U-Boot to a new CPU, then also create a new 2103 directory to hold your CPU specific code. Add any files you need. 2104 4. Run "make <board>_config" with your new name. 2105 5. Type "make", and you should get a working "u-boot.srec" file 2106 to be installed on your target system. 2107 6. Debug and solve any problems that might arise. 2108 [Of course, this last step is much harder than it sounds.] 2109 2110 2111 Testing of U-Boot Modifications, Ports to New Hardware, etc.: 2112 ============================================================== 2113 2114 If you have modified U-Boot sources (for instance added a new board 2115 or support for new devices, a new CPU, etc.) you are expected to 2116 provide feedback to the other developers. The feedback normally takes 2117 the form of a "patch", i. e. a context diff against a certain (latest 2118 official or latest in CVS) version of U-Boot sources. 2119 2120 But before you submit such a patch, please verify that your modifi- 2121 cation did not break existing code. At least make sure that *ALL* of 2122 the supported boards compile WITHOUT ANY compiler warnings. To do so, 2123 just run the "MAKEALL" script, which will configure and build U-Boot 2124 for ALL supported system. Be warned, this will take a while. You can 2125 select which (cross) compiler to use by passing a `CROSS_COMPILE' 2126 environment variable to the script, i. e. to use the cross tools from 2127 MontaVista's Hard Hat Linux you can type 2128 2129 CROSS_COMPILE=ppc_8xx- MAKEALL 2130 2131 or to build on a native PowerPC system you can type 2132 2133 CROSS_COMPILE=' ' MAKEALL 2134 2135 See also "U-Boot Porting Guide" below. 2136 2137 2138 Monitor Commands - Overview: 2139 ============================ 2140 2141 go - start application at address 'addr' 2142 run - run commands in an environment variable 2143 bootm - boot application image from memory 2144 bootp - boot image via network using BootP/TFTP protocol 2145 tftpboot- boot image via network using TFTP protocol 2146 and env variables "ipaddr" and "serverip" 2147 (and eventually "gatewayip") 2148 rarpboot- boot image via network using RARP/TFTP protocol 2149 diskboot- boot from IDE devicebootd - boot default, i.e., run 'bootcmd' 2150 loads - load S-Record file over serial line 2151 loadb - load binary file over serial line (kermit mode) 2152 md - memory display 2153 mm - memory modify (auto-incrementing) 2154 nm - memory modify (constant address) 2155 mw - memory write (fill) 2156 cp - memory copy 2157 cmp - memory compare 2158 crc32 - checksum calculation 2159 imd - i2c memory display 2160 imm - i2c memory modify (auto-incrementing) 2161 inm - i2c memory modify (constant address) 2162 imw - i2c memory write (fill) 2163 icrc32 - i2c checksum calculation 2164 iprobe - probe to discover valid I2C chip addresses 2165 iloop - infinite loop on address range 2166 isdram - print SDRAM configuration information 2167 sspi - SPI utility commands 2168 base - print or set address offset 2169 printenv- print environment variables 2170 setenv - set environment variables 2171 saveenv - save environment variables to persistent storage 2172 protect - enable or disable FLASH write protection 2173 erase - erase FLASH memory 2174 flinfo - print FLASH memory information 2175 bdinfo - print Board Info structure 2176 iminfo - print header information for application image 2177 coninfo - print console devices and informations 2178 ide - IDE sub-system 2179 loop - infinite loop on address range 2180 mtest - simple RAM test 2181 icache - enable or disable instruction cache 2182 dcache - enable or disable data cache 2183 reset - Perform RESET of the CPU 2184 echo - echo args to console 2185 version - print monitor version 2186 help - print online help 2187 ? - alias for 'help' 2188 2189 2190 Monitor Commands - Detailed Description: 2191 ======================================== 2192 2193 TODO. 2194 2195 For now: just type "help <command>". 2196 2197 2198 Environment Variables: 2199 ====================== 2200 2201 U-Boot supports user configuration using Environment Variables which 2202 can be made persistent by saving to Flash memory. 2203 2204 Environment Variables are set using "setenv", printed using 2205 "printenv", and saved to Flash using "saveenv". Using "setenv" 2206 without a value can be used to delete a variable from the 2207 environment. As long as you don't save the environment you are 2208 working with an in-memory copy. In case the Flash area containing the 2209 environment is erased by accident, a default environment is provided. 2210 2211 Some configuration options can be set using Environment Variables: 2212 2213 baudrate - see CONFIG_BAUDRATE 2214 2215 bootdelay - see CONFIG_BOOTDELAY 2216 2217 bootcmd - see CONFIG_BOOTCOMMAND 2218 2219 bootargs - Boot arguments when booting an RTOS image 2220 2221 bootfile - Name of the image to load with TFTP 2222 2223 autoload - if set to "no" (any string beginning with 'n'), 2224 "bootp" will just load perform a lookup of the 2225 configuration from the BOOTP server, but not try to 2226 load any image using TFTP 2227 2228 autostart - if set to "yes", an image loaded using the "bootp", 2229 "rarpboot", "tftpboot" or "diskboot" commands will 2230 be automatically started (by internally calling 2231 "bootm") 2232 2233 If set to "no", a standalone image passed to the 2234 "bootm" command will be copied to the load address 2235 (and eventually uncompressed), but NOT be started. 2236 This can be used to load and uncompress arbitrary 2237 data. 2238 2239 initrd_high - restrict positioning of initrd images: 2240 If this variable is not set, initrd images will be 2241 copied to the highest possible address in RAM; this 2242 is usually what you want since it allows for 2243 maximum initrd size. If for some reason you want to 2244 make sure that the initrd image is loaded below the 2245 CFG_BOOTMAPSZ limit, you can set this environment 2246 variable to a value of "no" or "off" or "0". 2247 Alternatively, you can set it to a maximum upper 2248 address to use (U-Boot will still check that it 2249 does not overwrite the U-Boot stack and data). 2250 2251 For instance, when you have a system with 16 MB 2252 RAM, and want to reserve 4 MB from use by Linux, 2253 you can do this by adding "mem=12M" to the value of 2254 the "bootargs" variable. However, now you must make 2255 sure that the initrd image is placed in the first 2256 12 MB as well - this can be done with 2257 2258 setenv initrd_high 00c00000 2259 2260 If you set initrd_high to 0xFFFFFFFF, this is an 2261 indication to U-Boot that all addresses are legal 2262 for the Linux kernel, including addresses in flash 2263 memory. In this case U-Boot will NOT COPY the 2264 ramdisk at all. This may be useful to reduce the 2265 boot time on your system, but requires that this 2266 feature is supported by your Linux kernel. 2267 2268 ipaddr - IP address; needed for tftpboot command 2269 2270 loadaddr - Default load address for commands like "bootp", 2271 "rarpboot", "tftpboot", "loadb" or "diskboot" 2272 2273 loads_echo - see CONFIG_LOADS_ECHO 2274 2275 serverip - TFTP server IP address; needed for tftpboot command 2276 2277 bootretry - see CONFIG_BOOT_RETRY_TIME 2278 2279 bootdelaykey - see CONFIG_AUTOBOOT_DELAY_STR 2280 2281 bootstopkey - see CONFIG_AUTOBOOT_STOP_STR 2282 2283 ethprime - When CONFIG_NET_MULTI is enabled controls which 2284 interface is used first. 2285 2286 ethact - When CONFIG_NET_MULTI is enabled controls which 2287 interface is currently active. For example you 2288 can do the following 2289 2290 => setenv ethact FEC ETHERNET 2291 => ping 192.168.0.1 # traffic sent on FEC ETHERNET 2292 => setenv ethact SCC ETHERNET 2293 => ping 10.0.0.1 # traffic sent on SCC ETHERNET 2294 2295 netretry - When set to "no" each network operation will 2296 either succeed or fail without retrying. 2297 When set to "once" the network operation will 2298 fail when all the available network interfaces 2299 are tried once without success. 2300 Useful on scripts which control the retry operation 2301 themselves. 2302 2303 vlan - When set to a value < 4095 the traffic over 2304 ethernet is encapsulated/received over 802.1q 2305 VLAN tagged frames. 2306 2307 The following environment variables may be used and automatically 2308 updated by the network boot commands ("bootp" and "rarpboot"), 2309 depending the information provided by your boot server: 2310 2311 bootfile - see above 2312 dnsip - IP address of your Domain Name Server 2313 dnsip2 - IP address of your secondary Domain Name Server 2314 gatewayip - IP address of the Gateway (Router) to use 2315 hostname - Target hostname 2316 ipaddr - see above 2317 netmask - Subnet Mask 2318 rootpath - Pathname of the root filesystem on the NFS server 2319 serverip - see above 2320 2321 2322 There are two special Environment Variables: 2323 2324 serial# - contains hardware identification information such 2325 as type string and/or serial number 2326 ethaddr - Ethernet address 2327 2328 These variables can be set only once (usually during manufacturing of 2329 the board). U-Boot refuses to delete or overwrite these variables 2330 once they have been set once. 2331 2332 2333 Further special Environment Variables: 2334 2335 ver - Contains the U-Boot version string as printed 2336 with the "version" command. This variable is 2337 readonly (see CONFIG_VERSION_VARIABLE). 2338 2339 2340 Please note that changes to some configuration parameters may take 2341 only effect after the next boot (yes, that's just like Windoze :-). 2342 2343 2344 Command Line Parsing: 2345 ===================== 2346 2347 There are two different command line parsers available with U-Boot: 2348 the old "simple" one, and the much more powerful "hush" shell: 2349 2350 Old, simple command line parser: 2351 -------------------------------- 2352 2353 - supports environment variables (through setenv / saveenv commands) 2354 - several commands on one line, separated by ';' 2355 - variable substitution using "... $(name) ..." syntax 2356 - special characters ('$', ';') can be escaped by prefixing with '\', 2357 for example: 2358 setenv bootcmd bootm \$(address) 2359 - You can also escape text by enclosing in single apostrophes, for example: 2360 setenv addip 'setenv bootargs $bootargs ip=$ipaddr:$serverip:$gatewayip:$netmask:$hostname::off' 2361 2362 Hush shell: 2363 ----------- 2364 2365 - similar to Bourne shell, with control structures like 2366 if...then...else...fi, for...do...done; while...do...done, 2367 until...do...done, ... 2368 - supports environment ("global") variables (through setenv / saveenv 2369 commands) and local shell variables (through standard shell syntax 2370 "name=value"); only environment variables can be used with "run" 2371 command 2372 2373 General rules: 2374 -------------- 2375 2376 (1) If a command line (or an environment variable executed by a "run" 2377 command) contains several commands separated by semicolon, and 2378 one of these commands fails, then the remaining commands will be 2379 executed anyway. 2380 2381 (2) If you execute several variables with one call to run (i. e. 2382 calling run with a list af variables as arguments), any failing 2383 command will cause "run" to terminate, i. e. the remaining 2384 variables are not executed. 2385 2386 Note for Redundant Ethernet Interfaces: 2387 ======================================= 2388 2389 Some boards come with redundant ethernet interfaces; U-Boot supports 2390 such configurations and is capable of automatic selection of a 2391 "working" interface when needed. MAC assignment works as follows: 2392 2393 Network interfaces are numbered eth0, eth1, eth2, ... Corresponding 2394 MAC addresses can be stored in the environment as "ethaddr" (=>eth0), 2395 "eth1addr" (=>eth1), "eth2addr", ... 2396 2397 If the network interface stores some valid MAC address (for instance 2398 in SROM), this is used as default address if there is NO correspon- 2399 ding setting in the environment; if the corresponding environment 2400 variable is set, this overrides the settings in the card; that means: 2401 2402 o If the SROM has a valid MAC address, and there is no address in the 2403 environment, the SROM's address is used. 2404 2405 o If there is no valid address in the SROM, and a definition in the 2406 environment exists, then the value from the environment variable is 2407 used. 2408 2409 o If both the SROM and the environment contain a MAC address, and 2410 both addresses are the same, this MAC address is used. 2411 2412 o If both the SROM and the environment contain a MAC address, and the 2413 addresses differ, the value from the environment is used and a 2414 warning is printed. 2415 2416 o If neither SROM nor the environment contain a MAC address, an error 2417 is raised. 2418 2419 2420 Image Formats: 2421 ============== 2422 2423 The "boot" commands of this monitor operate on "image" files which 2424 can be basicly anything, preceeded by a special header; see the 2425 definitions in include/image.h for details; basicly, the header 2426 defines the following image properties: 2427 2428 * Target Operating System (Provisions for OpenBSD, NetBSD, FreeBSD, 2429 4.4BSD, Linux, SVR4, Esix, Solaris, Irix, SCO, Dell, NCR, VxWorks, 2430 LynxOS, pSOS, QNX, RTEMS, ARTOS; 2431 Currently supported: Linux, NetBSD, VxWorks, QNX, RTEMS, ARTOS, LynxOS). 2432 * Target CPU Architecture (Provisions for Alpha, ARM, Intel x86, 2433 IA64, MIPS, NIOS, PowerPC, IBM S390, SuperH, Sparc, Sparc 64 Bit; 2434 Currently supported: ARM, Intel x86, MIPS, NIOS, PowerPC). 2435 * Compression Type (uncompressed, gzip, bzip2) 2436 * Load Address 2437 * Entry Point 2438 * Image Name 2439 * Image Timestamp 2440 2441 The header is marked by a special Magic Number, and both the header 2442 and the data portions of the image are secured against corruption by 2443 CRC32 checksums. 2444 2445 2446 Linux Support: 2447 ============== 2448 2449 Although U-Boot should support any OS or standalone application 2450 easily, the main focus has always been on Linux during the design of 2451 U-Boot. 2452 2453 U-Boot includes many features that so far have been part of some 2454 special "boot loader" code within the Linux kernel. Also, any 2455 "initrd" images to be used are no longer part of one big Linux image; 2456 instead, kernel and "initrd" are separate images. This implementation 2457 serves several purposes: 2458 2459 - the same features can be used for other OS or standalone 2460 applications (for instance: using compressed images to reduce the 2461 Flash memory footprint) 2462 2463 - it becomes much easier to port new Linux kernel versions because 2464 lots of low-level, hardware dependent stuff are done by U-Boot 2465 2466 - the same Linux kernel image can now be used with different "initrd" 2467 images; of course this also means that different kernel images can 2468 be run with the same "initrd". This makes testing easier (you don't 2469 have to build a new "zImage.initrd" Linux image when you just 2470 change a file in your "initrd"). Also, a field-upgrade of the 2471 software is easier now. 2472 2473 2474 Linux HOWTO: 2475 ============ 2476 2477 Porting Linux to U-Boot based systems: 2478 --------------------------------------- 2479 2480 U-Boot cannot save you from doing all the necessary modifications to 2481 configure the Linux device drivers for use with your target hardware 2482 (no, we don't intend to provide a full virtual machine interface to 2483 Linux :-). 2484 2485 But now you can ignore ALL boot loader code (in arch/ppc/mbxboot). 2486 2487 Just make sure your machine specific header file (for instance 2488 include/asm-ppc/tqm8xx.h) includes the same definition of the Board 2489 Information structure as we define in include/u-boot.h, and make 2490 sure that your definition of IMAP_ADDR uses the same value as your 2491 U-Boot configuration in CFG_IMMR. 2492 2493 2494 Configuring the Linux kernel: 2495 ----------------------------- 2496 2497 No specific requirements for U-Boot. Make sure you have some root 2498 device (initial ramdisk, NFS) for your target system. 2499 2500 2501 Building a Linux Image: 2502 ----------------------- 2503 2504 With U-Boot, "normal" build targets like "zImage" or "bzImage" are 2505 not used. If you use recent kernel source, a new build target 2506 "uImage" will exist which automatically builds an image usable by 2507 U-Boot. Most older kernels also have support for a "pImage" target, 2508 which was introduced for our predecessor project PPCBoot and uses a 2509 100% compatible format. 2510 2511 Example: 2512 2513 make TQM850L_config 2514 make oldconfig 2515 make dep 2516 make uImage 2517 2518 The "uImage" build target uses a special tool (in 'tools/mkimage') to 2519 encapsulate a compressed Linux kernel image with header information, 2520 CRC32 checksum etc. for use with U-Boot. This is what we are doing: 2521 2522 * build a standard "vmlinux" kernel image (in ELF binary format): 2523 2524 * convert the kernel into a raw binary image: 2525 2526 ${CROSS_COMPILE}-objcopy -O binary \ 2527 -R .note -R .comment \ 2528 -S vmlinux linux.bin 2529 2530 * compress the binary image: 2531 2532 gzip -9 linux.bin 2533 2534 * package compressed binary image for U-Boot: 2535 2536 mkimage -A ppc -O linux -T kernel -C gzip \ 2537 -a 0 -e 0 -n "Linux Kernel Image" \ 2538 -d linux.bin.gz uImage 2539 2540 2541 The "mkimage" tool can also be used to create ramdisk images for use 2542 with U-Boot, either separated from the Linux kernel image, or 2543 combined into one file. "mkimage" encapsulates the images with a 64 2544 byte header containing information about target architecture, 2545 operating system, image type, compression method, entry points, time 2546 stamp, CRC32 checksums, etc. 2547 2548 "mkimage" can be called in two ways: to verify existing images and 2549 print the header information, or to build new images. 2550 2551 In the first form (with "-l" option) mkimage lists the information 2552 contained in the header of an existing U-Boot image; this includes 2553 checksum verification: 2554 2555 tools/mkimage -l image 2556 -l ==> list image header information 2557 2558 The second form (with "-d" option) is used to build a U-Boot image 2559 from a "data file" which is used as image payload: 2560 2561 tools/mkimage -A arch -O os -T type -C comp -a addr -e ep \ 2562 -n name -d data_file image 2563 -A ==> set architecture to 'arch' 2564 -O ==> set operating system to 'os' 2565 -T ==> set image type to 'type' 2566 -C ==> set compression type 'comp' 2567 -a ==> set load address to 'addr' (hex) 2568 -e ==> set entry point to 'ep' (hex) 2569 -n ==> set image name to 'name' 2570 -d ==> use image data from 'datafile' 2571 2572 Right now, all Linux kernels use the same load address (0x00000000), 2573 but the entry point address depends on the kernel version: 2574 2575 - 2.2.x kernels have the entry point at 0x0000000C, 2576 - 2.3.x and later kernels have the entry point at 0x00000000. 2577 2578 So a typical call to build a U-Boot image would read: 2579 2580 -> tools/mkimage -n '2.4.4 kernel for TQM850L' \ 2581 > -A ppc -O linux -T kernel -C gzip -a 0 -e 0 \ 2582 > -d /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/ppc/coffboot/vmlinux.gz \ 2583 > examples/uImage.TQM850L 2584 Image Name: 2.4.4 kernel for TQM850L 2585 Created: Wed Jul 19 02:34:59 2000 2586 Image Type: PowerPC Linux Kernel Image (gzip compressed) 2587 Data Size: 335725 Bytes = 327.86 kB = 0.32 MB 2588 Load Address: 0x00000000 2589 Entry Point: 0x00000000 2590 2591 To verify the contents of the image (or check for corruption): 2592 2593 -> tools/mkimage -l examples/uImage.TQM850L 2594 Image Name: 2.4.4 kernel for TQM850L 2595 Created: Wed Jul 19 02:34:59 2000 2596 Image Type: PowerPC Linux Kernel Image (gzip compressed) 2597 Data Size: 335725 Bytes = 327.86 kB = 0.32 MB 2598 Load Address: 0x00000000 2599 Entry Point: 0x00000000 2600 2601 NOTE: for embedded systems where boot time is critical you can trade 2602 speed for memory and install an UNCOMPRESSED image instead: this 2603 needs more space in Flash, but boots much faster since it does not 2604 need to be uncompressed: 2605 2606 -> gunzip /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/ppc/coffboot/vmlinux.gz 2607 -> tools/mkimage -n '2.4.4 kernel for TQM850L' \ 2608 > -A ppc -O linux -T kernel -C none -a 0 -e 0 \ 2609 > -d /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/ppc/coffboot/vmlinux \ 2610 > examples/uImage.TQM850L-uncompressed 2611 Image Name: 2.4.4 kernel for TQM850L 2612 Created: Wed Jul 19 02:34:59 2000 2613 Image Type: PowerPC Linux Kernel Image (uncompressed) 2614 Data Size: 792160 Bytes = 773.59 kB = 0.76 MB 2615 Load Address: 0x00000000 2616 Entry Point: 0x00000000 2617 2618 2619 Similar you can build U-Boot images from a 'ramdisk.image.gz' file 2620 when your kernel is intended to use an initial ramdisk: 2621 2622 -> tools/mkimage -n 'Simple Ramdisk Image' \ 2623 > -A ppc -O linux -T ramdisk -C gzip \ 2624 > -d /LinuxPPC/images/SIMPLE-ramdisk.image.gz examples/simple-initrd 2625 Image Name: Simple Ramdisk Image 2626 Created: Wed Jan 12 14:01:50 2000 2627 Image Type: PowerPC Linux RAMDisk Image (gzip compressed) 2628 Data Size: 566530 Bytes = 553.25 kB = 0.54 MB 2629 Load Address: 0x00000000 2630 Entry Point: 0x00000000 2631 2632 2633 Installing a Linux Image: 2634 ------------------------- 2635 2636 To downloading a U-Boot image over the serial (console) interface, 2637 you must convert the image to S-Record format: 2638 2639 objcopy -I binary -O srec examples/image examples/image.srec 2640 2641 The 'objcopy' does not understand the information in the U-Boot 2642 image header, so the resulting S-Record file will be relative to 2643 address 0x00000000. To load it to a given address, you need to 2644 specify the target address as 'offset' parameter with the 'loads' 2645 command. 2646 2647 Example: install the image to address 0x40100000 (which on the 2648 TQM8xxL is in the first Flash bank): 2649 2650 => erase 40100000 401FFFFF 2651 2652 .......... done 2653 Erased 8 sectors 2654 2655 => loads 40100000 2656 ## Ready for S-Record download ... 2657 ~>examples/image.srec 2658 1 2 3 4 5 6 7 8 9 10 11 12 13 ... 2659 ... 2660 15989 15990 15991 15992 2661 [file transfer complete] 2662 [connected] 2663 ## Start Addr = 0x00000000 2664 2665 2666 You can check the success of the download using the 'iminfo' command; 2667 this includes a checksum verification so you can be sure no data 2668 corruption happened: 2669 2670 => imi 40100000 2671 2672 ## Checking Image at 40100000 ... 2673 Image Name: 2.2.13 for initrd on TQM850L 2674 Image Type: PowerPC Linux Kernel Image (gzip compressed) 2675 Data Size: 335725 Bytes = 327 kB = 0 MB 2676 Load Address: 00000000 2677 Entry Point: 0000000c 2678 Verifying Checksum ... OK 2679 2680 2681 Boot Linux: 2682 ----------- 2683 2684 The "bootm" command is used to boot an application that is stored in 2685 memory (RAM or Flash). In case of a Linux kernel image, the contents 2686 of the "bootargs" environment variable is passed to the kernel as 2687 parameters. You can check and modify this variable using the 2688 "printenv" and "setenv" commands: 2689 2690 2691 => printenv bootargs 2692 bootargs=root=/dev/ram 2693 2694 => setenv bootargs root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2 2695 2696 => printenv bootargs 2697 bootargs=root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2 2698 2699 => bootm 40020000 2700 ## Booting Linux kernel at 40020000 ... 2701 Image Name: 2.2.13 for NFS on TQM850L 2702 Image Type: PowerPC Linux Kernel Image (gzip compressed) 2703 Data Size: 381681 Bytes = 372 kB = 0 MB 2704 Load Address: 00000000 2705 Entry Point: 0000000c 2706 Verifying Checksum ... OK 2707 Uncompressing Kernel Image ... OK 2708 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 2709 Boot arguments: root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2 2710 time_init: decrementer frequency = 187500000/60 2711 Calibrating delay loop... 49.77 BogoMIPS 2712 Memory: 15208k available (700k kernel code, 444k data, 32k init) [c0000000,c1000000] 2713 ... 2714 2715 If you want to boot a Linux kernel with initial ram disk, you pass 2716 the memory addresses of both the kernel and the initrd image (PPBCOOT 2717 format!) to the "bootm" command: 2718 2719 => imi 40100000 40200000 2720 2721 ## Checking Image at 40100000 ... 2722 Image Name: 2.2.13 for initrd on TQM850L 2723 Image Type: PowerPC Linux Kernel Image (gzip compressed) 2724 Data Size: 335725 Bytes = 327 kB = 0 MB 2725 Load Address: 00000000 2726 Entry Point: 0000000c 2727 Verifying Checksum ... OK 2728 2729 ## Checking Image at 40200000 ... 2730 Image Name: Simple Ramdisk Image 2731 Image Type: PowerPC Linux RAMDisk Image (gzip compressed) 2732 Data Size: 566530 Bytes = 553 kB = 0 MB 2733 Load Address: 00000000 2734 Entry Point: 00000000 2735 Verifying Checksum ... OK 2736 2737 => bootm 40100000 40200000 2738 ## Booting Linux kernel at 40100000 ... 2739 Image Name: 2.2.13 for initrd on TQM850L 2740 Image Type: PowerPC Linux Kernel Image (gzip compressed) 2741 Data Size: 335725 Bytes = 327 kB = 0 MB 2742 Load Address: 00000000 2743 Entry Point: 0000000c 2744 Verifying Checksum ... OK 2745 Uncompressing Kernel Image ... OK 2746 ## Loading RAMDisk Image at 40200000 ... 2747 Image Name: Simple Ramdisk Image 2748 Image Type: PowerPC Linux RAMDisk Image (gzip compressed) 2749 Data Size: 566530 Bytes = 553 kB = 0 MB 2750 Load Address: 00000000 2751 Entry Point: 00000000 2752 Verifying Checksum ... OK 2753 Loading Ramdisk ... OK 2754 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 2755 Boot arguments: root=/dev/ram 2756 time_init: decrementer frequency = 187500000/60 2757 Calibrating delay loop... 49.77 BogoMIPS 2758 ... 2759 RAMDISK: Compressed image found at block 0 2760 VFS: Mounted root (ext2 filesystem). 2761 2762 bash# 2763 2764 More About U-Boot Image Types: 2765 ------------------------------ 2766 2767 U-Boot supports the following image types: 2768 2769 "Standalone Programs" are directly runnable in the environment 2770 provided by U-Boot; it is expected that (if they behave 2771 well) you can continue to work in U-Boot after return from 2772 the Standalone Program. 2773 "OS Kernel Images" are usually images of some Embedded OS which 2774 will take over control completely. Usually these programs 2775 will install their own set of exception handlers, device 2776 drivers, set up the MMU, etc. - this means, that you cannot 2777 expect to re-enter U-Boot except by resetting the CPU. 2778 "RAMDisk Images" are more or less just data blocks, and their 2779 parameters (address, size) are passed to an OS kernel that is 2780 being started. 2781 "Multi-File Images" contain several images, typically an OS 2782 (Linux) kernel image and one or more data images like 2783 RAMDisks. This construct is useful for instance when you want 2784 to boot over the network using BOOTP etc., where the boot 2785 server provides just a single image file, but you want to get 2786 for instance an OS kernel and a RAMDisk image. 2787 2788 "Multi-File Images" start with a list of image sizes, each 2789 image size (in bytes) specified by an "uint32_t" in network 2790 byte order. This list is terminated by an "(uint32_t)0". 2791 Immediately after the terminating 0 follow the images, one by 2792 one, all aligned on "uint32_t" boundaries (size rounded up to 2793 a multiple of 4 bytes). 2794 2795 "Firmware Images" are binary images containing firmware (like 2796 U-Boot or FPGA images) which usually will be programmed to 2797 flash memory. 2798 2799 "Script files" are command sequences that will be executed by 2800 U-Boot's command interpreter; this feature is especially 2801 useful when you configure U-Boot to use a real shell (hush) 2802 as command interpreter. 2803 2804 2805 Standalone HOWTO: 2806 ================= 2807 2808 One of the features of U-Boot is that you can dynamically load and 2809 run "standalone" applications, which can use some resources of 2810 U-Boot like console I/O functions or interrupt services. 2811 2812 Two simple examples are included with the sources: 2813 2814 "Hello World" Demo: 2815 ------------------- 2816 2817 'examples/hello_world.c' contains a small "Hello World" Demo 2818 application; it is automatically compiled when you build U-Boot. 2819 It's configured to run at address 0x00040004, so you can play with it 2820 like that: 2821 2822 => loads 2823 ## Ready for S-Record download ... 2824 ~>examples/hello_world.srec 2825 1 2 3 4 5 6 7 8 9 10 11 ... 2826 [file transfer complete] 2827 [connected] 2828 ## Start Addr = 0x00040004 2829 2830 => go 40004 Hello World! This is a test. 2831 ## Starting application at 0x00040004 ... 2832 Hello World 2833 argc = 7 2834 argv[0] = "40004" 2835 argv[1] = "Hello" 2836 argv[2] = "World!" 2837 argv[3] = "This" 2838 argv[4] = "is" 2839 argv[5] = "a" 2840 argv[6] = "test." 2841 argv[7] = "<NULL>" 2842 Hit any key to exit ... 2843 2844 ## Application terminated, rc = 0x0 2845 2846 Another example, which demonstrates how to register a CPM interrupt 2847 handler with the U-Boot code, can be found in 'examples/timer.c'. 2848 Here, a CPM timer is set up to generate an interrupt every second. 2849 The interrupt service routine is trivial, just printing a '.' 2850 character, but this is just a demo program. The application can be 2851 controlled by the following keys: 2852 2853 ? - print current values og the CPM Timer registers 2854 b - enable interrupts and start timer 2855 e - stop timer and disable interrupts 2856 q - quit application 2857 2858 => loads 2859 ## Ready for S-Record download ... 2860 ~>examples/timer.srec 2861 1 2 3 4 5 6 7 8 9 10 11 ... 2862 [file transfer complete] 2863 [connected] 2864 ## Start Addr = 0x00040004 2865 2866 => go 40004 2867 ## Starting application at 0x00040004 ... 2868 TIMERS=0xfff00980 2869 Using timer 1 2870 tgcr @ 0xfff00980, tmr @ 0xfff00990, trr @ 0xfff00994, tcr @ 0xfff00998, tcn @ 0xfff0099c, ter @ 0xfff009b0 2871 2872 Hit 'b': 2873 [q, b, e, ?] Set interval 1000000 us 2874 Enabling timer 2875 Hit '?': 2876 [q, b, e, ?] ........ 2877 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0xef6, ter=0x0 2878 Hit '?': 2879 [q, b, e, ?] . 2880 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x2ad4, ter=0x0 2881 Hit '?': 2882 [q, b, e, ?] . 2883 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x1efc, ter=0x0 2884 Hit '?': 2885 [q, b, e, ?] . 2886 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x169d, ter=0x0 2887 Hit 'e': 2888 [q, b, e, ?] ...Stopping timer 2889 Hit 'q': 2890 [q, b, e, ?] ## Application terminated, rc = 0x0 2891 2892 2893 Minicom warning: 2894 ================ 2895 2896 Over time, many people have reported problems when trying to use the 2897 "minicom" terminal emulation program for serial download. I (wd) 2898 consider minicom to be broken, and recommend not to use it. Under 2899 Unix, I recommend to use C-Kermit for general purpose use (and 2900 especially for kermit binary protocol download ("loadb" command), and 2901 use "cu" for S-Record download ("loads" command). 2902 2903 Nevertheless, if you absolutely want to use it try adding this 2904 configuration to your "File transfer protocols" section: 2905 2906 Name Program Name U/D FullScr IO-Red. Multi 2907 X kermit /usr/bin/kermit -i -l %l -s Y U Y N N 2908 Y kermit /usr/bin/kermit -i -l %l -r N D Y N N 2909 2910 2911 NetBSD Notes: 2912 ============= 2913 2914 Starting at version 0.9.2, U-Boot supports NetBSD both as host 2915 (build U-Boot) and target system (boots NetBSD/mpc8xx). 2916 2917 Building requires a cross environment; it is known to work on 2918 NetBSD/i386 with the cross-powerpc-netbsd-1.3 package (you will also 2919 need gmake since the Makefiles are not compatible with BSD make). 2920 Note that the cross-powerpc package does not install include files; 2921 attempting to build U-Boot will fail because <machine/ansi.h> is 2922 missing. This file has to be installed and patched manually: 2923 2924 # cd /usr/pkg/cross/powerpc-netbsd/include 2925 # mkdir powerpc 2926 # ln -s powerpc machine 2927 # cp /usr/src/sys/arch/powerpc/include/ansi.h powerpc/ansi.h 2928 # ${EDIT} powerpc/ansi.h ## must remove __va_list, _BSD_VA_LIST 2929 2930 Native builds *don't* work due to incompatibilities between native 2931 and U-Boot include files. 2932 2933 Booting assumes that (the first part of) the image booted is a 2934 stage-2 loader which in turn loads and then invokes the kernel 2935 proper. Loader sources will eventually appear in the NetBSD source 2936 tree (probably in sys/arc/mpc8xx/stand/u-boot_stage2/); in the 2937 meantime, send mail to bruno@exet-ag.de and/or wd@denx.de for 2938 details. 2939 2940 2941 Implementation Internals: 2942 ========================= 2943 2944 The following is not intended to be a complete description of every 2945 implementation detail. However, it should help to understand the 2946 inner workings of U-Boot and make it easier to port it to custom 2947 hardware. 2948 2949 2950 Initial Stack, Global Data: 2951 --------------------------- 2952 2953 The implementation of U-Boot is complicated by the fact that U-Boot 2954 starts running out of ROM (flash memory), usually without access to 2955 system RAM (because the memory controller is not initialized yet). 2956 This means that we don't have writable Data or BSS segments, and BSS 2957 is not initialized as zero. To be able to get a C environment working 2958 at all, we have to allocate at least a minimal stack. Implementation 2959 options for this are defined and restricted by the CPU used: Some CPU 2960 models provide on-chip memory (like the IMMR area on MPC8xx and 2961 MPC826x processors), on others (parts of) the data cache can be 2962 locked as (mis-) used as memory, etc. 2963 2964 Chris Hallinan posted a good summary of these issues to the 2965 u-boot-users mailing list: 2966 2967 Subject: RE: [U-Boot-Users] RE: More On Memory Bank x (nothingness)? 2968 From: "Chris Hallinan" <clh@net1plus.com> 2969 Date: Mon, 10 Feb 2003 16:43:46 -0500 (22:43 MET) 2970 ... 2971 2972 Correct me if I'm wrong, folks, but the way I understand it 2973 is this: Using DCACHE as initial RAM for Stack, etc, does not 2974 require any physical RAM backing up the cache. The cleverness 2975 is that the cache is being used as a temporary supply of 2976 necessary storage before the SDRAM controller is setup. It's 2977 beyond the scope of this list to expain the details, but you 2978 can see how this works by studying the cache architecture and 2979 operation in the architecture and processor-specific manuals. 2980 2981 OCM is On Chip Memory, which I believe the 405GP has 4K. It 2982 is another option for the system designer to use as an 2983 initial stack/ram area prior to SDRAM being available. Either 2984 option should work for you. Using CS 4 should be fine if your 2985 board designers haven't used it for something that would 2986 cause you grief during the initial boot! It is frequently not 2987 used. 2988 2989 CFG_INIT_RAM_ADDR should be somewhere that won't interfere 2990 with your processor/board/system design. The default value 2991 you will find in any recent u-boot distribution in 2992 Walnut405.h should work for you. I'd set it to a value larger 2993 than your SDRAM module. If you have a 64MB SDRAM module, set 2994 it above 400_0000. Just make sure your board has no resources 2995 that are supposed to respond to that address! That code in 2996 start.S has been around a while and should work as is when 2997 you get the config right. 2998 2999 -Chris Hallinan 3000 DS4.COM, Inc. 3001 3002 It is essential to remember this, since it has some impact on the C 3003 code for the initialization procedures: 3004 3005 * Initialized global data (data segment) is read-only. Do not attempt 3006 to write it. 3007 3008 * Do not use any unitialized global data (or implicitely initialized 3009 as zero data - BSS segment) at all - this is undefined, initiali- 3010 zation is performed later (when relocating to RAM). 3011 3012 * Stack space is very limited. Avoid big data buffers or things like 3013 that. 3014 3015 Having only the stack as writable memory limits means we cannot use 3016 normal global data to share information beween the code. But it 3017 turned out that the implementation of U-Boot can be greatly 3018 simplified by making a global data structure (gd_t) available to all 3019 functions. We could pass a pointer to this data as argument to _all_ 3020 functions, but this would bloat the code. Instead we use a feature of 3021 the GCC compiler (Global Register Variables) to share the data: we 3022 place a pointer (gd) to the global data into a register which we 3023 reserve for this purpose. 3024 3025 When choosing a register for such a purpose we are restricted by the 3026 relevant (E)ABI specifications for the current architecture, and by 3027 GCC's implementation. 3028 3029 For PowerPC, the following registers have specific use: 3030 R1: stack pointer 3031 R2: TOC pointer 3032 R3-R4: parameter passing and return values 3033 R5-R10: parameter passing 3034 R13: small data area pointer 3035 R30: GOT pointer 3036 R31: frame pointer 3037 3038 (U-Boot also uses R14 as internal GOT pointer.) 3039 3040 ==> U-Boot will use R29 to hold a pointer to the global data 3041 3042 Note: on PPC, we could use a static initializer (since the 3043 address of the global data structure is known at compile time), 3044 but it turned out that reserving a register results in somewhat 3045 smaller code - although the code savings are not that big (on 3046 average for all boards 752 bytes for the whole U-Boot image, 3047 624 text + 127 data). 3048 3049 On ARM, the following registers are used: 3050 3051 R0: function argument word/integer result 3052 R1-R3: function argument word 3053 R9: GOT pointer 3054 R10: stack limit (used only if stack checking if enabled) 3055 R11: argument (frame) pointer 3056 R12: temporary workspace 3057 R13: stack pointer 3058 R14: link register 3059 R15: program counter 3060 3061 ==> U-Boot will use R8 to hold a pointer to the global data 3062 3063 3064 Memory Management: 3065 ------------------ 3066 3067 U-Boot runs in system state and uses physical addresses, i.e. the 3068 MMU is not used either for address mapping nor for memory protection. 3069 3070 The available memory is mapped to fixed addresses using the memory 3071 controller. In this process, a contiguous block is formed for each 3072 memory type (Flash, SDRAM, SRAM), even when it consists of several 3073 physical memory banks. 3074 3075 U-Boot is installed in the first 128 kB of the first Flash bank (on 3076 TQM8xxL modules this is the range 0x40000000 ... 0x4001FFFF). After 3077 booting and sizing and initializing DRAM, the code relocates itself 3078 to the upper end of DRAM. Immediately below the U-Boot code some 3079 memory is reserved for use by malloc() [see CFG_MALLOC_LEN 3080 configuration setting]. Below that, a structure with global Board 3081 Info data is placed, followed by the stack (growing downward). 3082 3083 Additionally, some exception handler code is copied to the low 8 kB 3084 of DRAM (0x00000000 ... 0x00001FFF). 3085 3086 So a typical memory configuration with 16 MB of DRAM could look like 3087 this: 3088 3089 0x0000 0000 Exception Vector code 3090 : 3091 0x0000 1FFF 3092 0x0000 2000 Free for Application Use 3093 : 3094 : 3095 3096 : 3097 : 3098 0x00FB FF20 Monitor Stack (Growing downward) 3099 0x00FB FFAC Board Info Data and permanent copy of global data 3100 0x00FC 0000 Malloc Arena 3101 : 3102 0x00FD FFFF 3103 0x00FE 0000 RAM Copy of Monitor Code 3104 ... eventually: LCD or video framebuffer 3105 ... eventually: pRAM (Protected RAM - unchanged by reset) 3106 0x00FF FFFF [End of RAM] 3107 3108 3109 System Initialization: 3110 ---------------------- 3111 3112 In the reset configuration, U-Boot starts at the reset entry point 3113 (on most PowerPC systens at address 0x00000100). Because of the reset 3114 configuration for CS0# this is a mirror of the onboard Flash memory. 3115 To be able to re-map memory U-Boot then jumps to its link address. 3116 To be able to implement the initialization code in C, a (small!) 3117 initial stack is set up in the internal Dual Ported RAM (in case CPUs 3118 which provide such a feature like MPC8xx or MPC8260), or in a locked 3119 part of the data cache. After that, U-Boot initializes the CPU core, 3120 the caches and the SIU. 3121 3122 Next, all (potentially) available memory banks are mapped using a 3123 preliminary mapping. For example, we put them on 512 MB boundaries 3124 (multiples of 0x20000000: SDRAM on 0x00000000 and 0x20000000, Flash 3125 on 0x40000000 and 0x60000000, SRAM on 0x80000000). Then UPM A is 3126 programmed for SDRAM access. Using the temporary configuration, a 3127 simple memory test is run that determines the size of the SDRAM 3128 banks. 3129 3130 When there is more than one SDRAM bank, and the banks are of 3131 different size, the largest is mapped first. For equal size, the first 3132 bank (CS2#) is mapped first. The first mapping is always for address 3133 0x00000000, with any additional banks following immediately to create 3134 contiguous memory starting from 0. 3135 3136 Then, the monitor installs itself at the upper end of the SDRAM area 3137 and allocates memory for use by malloc() and for the global Board 3138 Info data; also, the exception vector code is copied to the low RAM 3139 pages, and the final stack is set up. 3140 3141 Only after this relocation will you have a "normal" C environment; 3142 until that you are restricted in several ways, mostly because you are 3143 running from ROM, and because the code will have to be relocated to a 3144 new address in RAM. 3145 3146 3147 U-Boot Porting Guide: 3148 ---------------------- 3149 3150 [Based on messages by Jerry Van Baren in the U-Boot-Users mailing 3151 list, October 2002] 3152 3153 3154 int main (int argc, char *argv[]) 3155 { 3156 sighandler_t no_more_time; 3157 3158 signal (SIGALRM, no_more_time); 3159 alarm (PROJECT_DEADLINE - toSec (3 * WEEK)); 3160 3161 if (available_money > available_manpower) { 3162 pay consultant to port U-Boot; 3163 return 0; 3164 } 3165 3166 Download latest U-Boot source; 3167 3168 Subscribe to u-boot-users mailing list; 3169 3170 if (clueless) { 3171 email ("Hi, I am new to U-Boot, how do I get started?"); 3172 } 3173 3174 while (learning) { 3175 Read the README file in the top level directory; 3176 Read http://www.denx.de/twiki/bin/view/DULG/Manual ; 3177 Read the source, Luke; 3178 } 3179 3180 if (available_money > toLocalCurrency ($2500)) { 3181 Buy a BDI2000; 3182 } else { 3183 Add a lot of aggravation and time; 3184 } 3185 3186 Create your own board support subdirectory; 3187 3188 Create your own board config file; 3189 3190 while (!running) { 3191 do { 3192 Add / modify source code; 3193 } until (compiles); 3194 Debug; 3195 if (clueless) 3196 email ("Hi, I am having problems..."); 3197 } 3198 Send patch file to Wolfgang; 3199 3200 return 0; 3201 } 3202 3203 void no_more_time (int sig) 3204 { 3205 hire_a_guru(); 3206 } 3207 3208 3209 Coding Standards: 3210 ----------------- 3211 3212 All contributions to U-Boot should conform to the Linux kernel 3213 coding style; see the file "Documentation/CodingStyle" in your Linux 3214 kernel source directory. 3215 3216 Please note that U-Boot is implemented in C (and to some small parts 3217 in Assembler); no C++ is used, so please do not use C++ style 3218 comments (//) in your code. 3219 3220 Please also stick to the following formatting rules: 3221 - remove any trailing white space 3222 - use TAB characters for indentation, not spaces 3223 - make sure NOT to use DOS '\r\n' line feeds 3224 - do not add more than 2 empty lines to source files 3225 - do not add trailing empty lines to source files 3226 3227 Submissions which do not conform to the standards may be returned 3228 with a request to reformat the changes. 3229 3230 3231 Submitting Patches: 3232 ------------------- 3233 3234 Since the number of patches for U-Boot is growing, we need to 3235 establish some rules. Submissions which do not conform to these rules 3236 may be rejected, even when they contain important and valuable stuff. 3237 3238 3239 When you send a patch, please include the following information with 3240 it: 3241 3242 * For bug fixes: a description of the bug and how your patch fixes 3243 this bug. Please try to include a way of demonstrating that the 3244 patch actually fixes something. 3245 3246 * For new features: a description of the feature and your 3247 implementation. 3248 3249 * A CHANGELOG entry as plaintext (separate from the patch) 3250 3251 * For major contributions, your entry to the CREDITS file 3252 3253 * When you add support for a new board, don't forget to add this 3254 board to the MAKEALL script, too. 3255 3256 * If your patch adds new configuration options, don't forget to 3257 document these in the README file. 3258 3259 * The patch itself. If you are accessing the CVS repository use "cvs 3260 update; cvs diff -puRN"; else, use "diff -purN OLD NEW". If your 3261 version of diff does not support these options, then get the latest 3262 version of GNU diff. 3263 3264 The current directory when running this command shall be the top 3265 level directory of the U-Boot source tree, or it's parent directory 3266 (i. e. please make sure that your patch includes sufficient 3267 directory information for the affected files). 3268 3269 We accept patches as plain text, MIME attachments or as uuencoded 3270 gzipped text. 3271 3272 * If one logical set of modifications affects or creates several 3273 files, all these changes shall be submitted in a SINGLE patch file. 3274 3275 * Changesets that contain different, unrelated modifications shall be 3276 submitted as SEPARATE patches, one patch per changeset. 3277 3278 3279 Notes: 3280 3281 * Before sending the patch, run the MAKEALL script on your patched 3282 source tree and make sure that no errors or warnings are reported 3283 for any of the boards. 3284 3285 * Keep your modifications to the necessary minimum: A patch 3286 containing several unrelated changes or arbitrary reformats will be 3287 returned with a request to re-formatting / split it. 3288 3289 * If you modify existing code, make sure that your new code does not 3290 add to the memory footprint of the code ;-) Small is beautiful! 3291 When adding new features, these should compile conditionally only 3292 (using #ifdef), and the resulting code with the new feature 3293 disabled must not need more memory than the old code without your 3294 modification. 3295