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_MICROBLAZE 246 247 248- Board Type: Define exactly one of 249 250 PowerPC based boards: 251 --------------------- 252 253 CONFIG_ADCIOP CONFIG_GEN860T CONFIG_PCI405 254 CONFIG_ADS860 CONFIG_GENIETV CONFIG_PCIPPC2 255 CONFIG_AMX860 CONFIG_GTH CONFIG_PCIPPC6 256 CONFIG_AR405 CONFIG_gw8260 CONFIG_pcu_e 257 CONFIG_BAB7xx CONFIG_hermes CONFIG_PIP405 258 CONFIG_c2mon CONFIG_hymod CONFIG_PM826 259 CONFIG_CANBT CONFIG_IAD210 CONFIG_ppmc8260 260 CONFIG_CCM CONFIG_ICU862 CONFIG_QS823 261 CONFIG_CMI CONFIG_IP860 CONFIG_QS850 262 CONFIG_cogent_mpc8260 CONFIG_IPHASE4539 CONFIG_QS860T 263 CONFIG_cogent_mpc8xx CONFIG_IVML24 CONFIG_RBC823 264 CONFIG_CPCI405 CONFIG_IVML24_128 CONFIG_RPXClassic 265 CONFIG_CPCI4052 CONFIG_IVML24_256 CONFIG_RPXlite 266 CONFIG_CPCIISER4 CONFIG_IVMS8 CONFIG_RPXsuper 267 CONFIG_CPU86 CONFIG_IVMS8_128 CONFIG_rsdproto 268 CONFIG_CRAYL1 CONFIG_IVMS8_256 CONFIG_sacsng 269 CONFIG_CSB272 CONFIG_JSE CONFIG_Sandpoint8240 270 CONFIG_CU824 CONFIG_LANTEC CONFIG_Sandpoint8245 271 CONFIG_DASA_SIM CONFIG_lwmon CONFIG_sbc8260 272 CONFIG_DB64360 CONFIG_MBX CONFIG_sbc8560 273 CONFIG_DB64460 CONFIG_MBX860T CONFIG_SM850 274 CONFIG_DU405 CONFIG_MHPC CONFIG_SPD823TS 275 CONFIG_DUET_ADS CONFIG_MIP405 CONFIG_STXGP3 276 CONFIG_EBONY CONFIG_MOUSSE CONFIG_SXNI855T 277 CONFIG_ELPPC CONFIG_MPC8260ADS CONFIG_TQM823L 278 CONFIG_ELPT860 CONFIG_MPC8540ADS CONFIG_TQM8260 279 CONFIG_ep8260 CONFIG_MPC8560ADS CONFIG_TQM850L 280 CONFIG_ERIC CONFIG_MUSENKI CONFIG_TQM855L 281 CONFIG_ESTEEM192E CONFIG_MVS1 CONFIG_TQM860L 282 CONFIG_ETX094 CONFIG_NETPHONE CONFIG_TTTech 283 CONFIG_EVB64260 CONFIG_NETTA CONFIG_UTX8245 284 CONFIG_FADS823 CONFIG_NETVIA CONFIG_V37 285 CONFIG_FADS850SAR CONFIG_NX823 CONFIG_W7OLMC 286 CONFIG_FADS860T CONFIG_OCRTC CONFIG_W7OLMG 287 CONFIG_FLAGADM CONFIG_ORSG CONFIG_WALNUT405 288 CONFIG_FPS850L CONFIG_OXC CONFIG_ZPC1900 289 CONFIG_FPS860L CONFIG_ZUMA 290 291 ARM based boards: 292 ----------------- 293 294 CONFIG_AT91RM9200DK, CONFIG_CERF250, CONFIG_DNP1110, 295 CONFIG_EP7312, CONFIG_H2_OMAP1610, CONFIG_HHP_CRADLE, 296 CONFIG_IMPA7, CONFIG_INNOVATOROMAP1510, CONFIG_INNOVATOROMAP1610, 297 CONFIG_LART, CONFIG_LPD7A400 CONFIG_LUBBOCK, 298 CONFIG_OSK_OMAP5912, CONFIG_SHANNON, CONFIG_P2_OMAP730, 299 CONFIG_SMDK2400, CONFIG_SMDK2410, CONFIG_TRAB, 300 CONFIG_VCMA9 301 302 MicroBlaze based boards: 303 ------------------------ 304 305 CONFIG_SUZAKU 306 307 308- CPU Module Type: (if CONFIG_COGENT is defined) 309 Define exactly one of 310 CONFIG_CMA286_60_OLD 311--- FIXME --- not tested yet: 312 CONFIG_CMA286_60, CONFIG_CMA286_21, CONFIG_CMA286_60P, 313 CONFIG_CMA287_23, CONFIG_CMA287_50 314 315- Motherboard Type: (if CONFIG_COGENT is defined) 316 Define exactly one of 317 CONFIG_CMA101, CONFIG_CMA102 318 319- Motherboard I/O Modules: (if CONFIG_COGENT is defined) 320 Define one or more of 321 CONFIG_CMA302 322 323- Motherboard Options: (if CONFIG_CMA101 or CONFIG_CMA102 are defined) 324 Define one or more of 325 CONFIG_LCD_HEARTBEAT - update a character position on 326 the lcd display every second with 327 a "rotator" |\-/|\-/ 328 329- Board flavour: (if CONFIG_MPC8260ADS is defined) 330 CONFIG_ADSTYPE 331 Possible values are: 332 CFG_8260ADS - original MPC8260ADS 333 CFG_8266ADS - MPC8266ADS 334 CFG_PQ2FADS - PQ2FADS-ZU or PQ2FADS-VR 335 CFG_8272ADS - MPC8272ADS 336 337- MPC824X Family Member (if CONFIG_MPC824X is defined) 338 Define exactly one of 339 CONFIG_MPC8240, CONFIG_MPC8245 340 341- 8xx CPU Options: (if using an MPC8xx cpu) 342 Define one or more of 343 CONFIG_8xx_GCLK_FREQ - if get_gclk_freq() cannot work 344 e.g. if there is no 32KHz 345 reference PIT/RTC clock 346 347- 859/866 CPU options: (if using a MPC859 or MPC866 CPU): 348 CFG_866_OSCCLK 349 CFG_866_CPUCLK_MIN 350 CFG_866_CPUCLK_MAX 351 CFG_866_CPUCLK_DEFAULT 352 See doc/README.MPC866 353 354 CFG_MEASURE_CPUCLK 355 356 Define this to measure the actual CPU clock instead 357 of relying on the correctness of the configured 358 values. Mostly useful for board bringup to make sure 359 the PLL is locked at the intended frequency. Note 360 that this requires a (stable) reference clock (32 kHz 361 RTC clock), 362 363- Linux Kernel Interface: 364 CONFIG_CLOCKS_IN_MHZ 365 366 U-Boot stores all clock information in Hz 367 internally. For binary compatibility with older Linux 368 kernels (which expect the clocks passed in the 369 bd_info data to be in MHz) the environment variable 370 "clocks_in_mhz" can be defined so that U-Boot 371 converts clock data to MHZ before passing it to the 372 Linux kernel. 373 When CONFIG_CLOCKS_IN_MHZ is defined, a definition of 374 "clocks_in_mhz=1" is automatically included in the 375 default environment. 376 377 CONFIG_MEMSIZE_IN_BYTES [relevant for MIPS only] 378 379 When transfering memsize parameter to linux, some versions 380 expect it to be in bytes, others in MB. 381 Define CONFIG_MEMSIZE_IN_BYTES to make it in bytes. 382 383- Serial Ports: 384 CFG_PL010_SERIAL 385 386 Define this if you want support for Amba PrimeCell PL010 UARTs. 387 388 CFG_PL011_SERIAL 389 390 Define this if you want support for Amba PrimeCell PL011 UARTs. 391 392 CONFIG_PL011_CLOCK 393 394 If you have Amba PrimeCell PL011 UARTs, set this variable to 395 the clock speed of the UARTs. 396 397 CONFIG_PL01x_PORTS 398 399 If you have Amba PrimeCell PL010 or PL011 UARTs on your board, 400 define this to a list of base addresses for each (supported) 401 port. See e.g. include/configs/versatile.h 402 403 404- Console Interface: 405 Depending on board, define exactly one serial port 406 (like CONFIG_8xx_CONS_SMC1, CONFIG_8xx_CONS_SMC2, 407 CONFIG_8xx_CONS_SCC1, ...), or switch off the serial 408 console by defining CONFIG_8xx_CONS_NONE 409 410 Note: if CONFIG_8xx_CONS_NONE is defined, the serial 411 port routines must be defined elsewhere 412 (i.e. serial_init(), serial_getc(), ...) 413 414 CONFIG_CFB_CONSOLE 415 Enables console device for a color framebuffer. Needs following 416 defines (cf. smiLynxEM, i8042, board/eltec/bab7xx) 417 VIDEO_FB_LITTLE_ENDIAN graphic memory organisation 418 (default big endian) 419 VIDEO_HW_RECTFILL graphic chip supports 420 rectangle fill 421 (cf. smiLynxEM) 422 VIDEO_HW_BITBLT graphic chip supports 423 bit-blit (cf. smiLynxEM) 424 VIDEO_VISIBLE_COLS visible pixel columns 425 (cols=pitch) 426 VIDEO_VISIBLE_ROWS visible pixel rows 427 VIDEO_PIXEL_SIZE bytes per pixel 428 VIDEO_DATA_FORMAT graphic data format 429 (0-5, cf. cfb_console.c) 430 VIDEO_FB_ADRS framebuffer address 431 VIDEO_KBD_INIT_FCT keyboard int fct 432 (i.e. i8042_kbd_init()) 433 VIDEO_TSTC_FCT test char fct 434 (i.e. i8042_tstc) 435 VIDEO_GETC_FCT get char fct 436 (i.e. i8042_getc) 437 CONFIG_CONSOLE_CURSOR cursor drawing on/off 438 (requires blink timer 439 cf. i8042.c) 440 CFG_CONSOLE_BLINK_COUNT blink interval (cf. i8042.c) 441 CONFIG_CONSOLE_TIME display time/date info in 442 upper right corner 443 (requires CFG_CMD_DATE) 444 CONFIG_VIDEO_LOGO display Linux logo in 445 upper left corner 446 CONFIG_VIDEO_BMP_LOGO use bmp_logo.h instead of 447 linux_logo.h for logo. 448 Requires CONFIG_VIDEO_LOGO 449 CONFIG_CONSOLE_EXTRA_INFO 450 addional board info beside 451 the logo 452 453 When CONFIG_CFB_CONSOLE is defined, video console is 454 default i/o. Serial console can be forced with 455 environment 'console=serial'. 456 457 When CONFIG_SILENT_CONSOLE is defined, all console 458 messages (by U-Boot and Linux!) can be silenced with 459 the "silent" environment variable. See 460 doc/README.silent for more information. 461 462- Console Baudrate: 463 CONFIG_BAUDRATE - in bps 464 Select one of the baudrates listed in 465 CFG_BAUDRATE_TABLE, see below. 466 CFG_BRGCLK_PRESCALE, baudrate prescale 467 468- Interrupt driven serial port input: 469 CONFIG_SERIAL_SOFTWARE_FIFO 470 471 PPC405GP only. 472 Use an interrupt handler for receiving data on the 473 serial port. It also enables using hardware handshake 474 (RTS/CTS) and UART's built-in FIFO. Set the number of 475 bytes the interrupt driven input buffer should have. 476 477 Leave undefined to disable this feature, including 478 disable the buffer and hardware handshake. 479 480- Console UART Number: 481 CONFIG_UART1_CONSOLE 482 483 IBM PPC4xx only. 484 If defined internal UART1 (and not UART0) is used 485 as default U-Boot console. 486 487- Boot Delay: CONFIG_BOOTDELAY - in seconds 488 Delay before automatically booting the default image; 489 set to -1 to disable autoboot. 490 491 See doc/README.autoboot for these options that 492 work with CONFIG_BOOTDELAY. None are required. 493 CONFIG_BOOT_RETRY_TIME 494 CONFIG_BOOT_RETRY_MIN 495 CONFIG_AUTOBOOT_KEYED 496 CONFIG_AUTOBOOT_PROMPT 497 CONFIG_AUTOBOOT_DELAY_STR 498 CONFIG_AUTOBOOT_STOP_STR 499 CONFIG_AUTOBOOT_DELAY_STR2 500 CONFIG_AUTOBOOT_STOP_STR2 501 CONFIG_ZERO_BOOTDELAY_CHECK 502 CONFIG_RESET_TO_RETRY 503 504- Autoboot Command: 505 CONFIG_BOOTCOMMAND 506 Only needed when CONFIG_BOOTDELAY is enabled; 507 define a command string that is automatically executed 508 when no character is read on the console interface 509 within "Boot Delay" after reset. 510 511 CONFIG_BOOTARGS 512 This can be used to pass arguments to the bootm 513 command. The value of CONFIG_BOOTARGS goes into the 514 environment value "bootargs". 515 516 CONFIG_RAMBOOT and CONFIG_NFSBOOT 517 The value of these goes into the environment as 518 "ramboot" and "nfsboot" respectively, and can be used 519 as a convenience, when switching between booting from 520 ram and nfs. 521 522- Pre-Boot Commands: 523 CONFIG_PREBOOT 524 525 When this option is #defined, the existence of the 526 environment variable "preboot" will be checked 527 immediately before starting the CONFIG_BOOTDELAY 528 countdown and/or running the auto-boot command resp. 529 entering interactive mode. 530 531 This feature is especially useful when "preboot" is 532 automatically generated or modified. For an example 533 see the LWMON board specific code: here "preboot" is 534 modified when the user holds down a certain 535 combination of keys on the (special) keyboard when 536 booting the systems 537 538- Serial Download Echo Mode: 539 CONFIG_LOADS_ECHO 540 If defined to 1, all characters received during a 541 serial download (using the "loads" command) are 542 echoed back. This might be needed by some terminal 543 emulations (like "cu"), but may as well just take 544 time on others. This setting #define's the initial 545 value of the "loads_echo" environment variable. 546 547- Kgdb Serial Baudrate: (if CFG_CMD_KGDB is defined) 548 CONFIG_KGDB_BAUDRATE 549 Select one of the baudrates listed in 550 CFG_BAUDRATE_TABLE, see below. 551 552- Monitor Functions: 553 CONFIG_COMMANDS 554 Most monitor functions can be selected (or 555 de-selected) by adjusting the definition of 556 CONFIG_COMMANDS; to select individual functions, 557 #define CONFIG_COMMANDS by "OR"ing any of the 558 following values: 559 560 #define enables commands: 561 ------------------------- 562 CFG_CMD_ASKENV * ask for env variable 563 CFG_CMD_AUTOSCRIPT Autoscript Support 564 CFG_CMD_BDI bdinfo 565 CFG_CMD_BEDBUG * Include BedBug Debugger 566 CFG_CMD_BMP * BMP support 567 CFG_CMD_BSP * Board specific commands 568 CFG_CMD_BOOTD bootd 569 CFG_CMD_CACHE * icache, dcache 570 CFG_CMD_CONSOLE coninfo 571 CFG_CMD_DATE * support for RTC, date/time... 572 CFG_CMD_DHCP * DHCP support 573 CFG_CMD_DIAG * Diagnostics 574 CFG_CMD_DOC * Disk-On-Chip Support 575 CFG_CMD_DTT * Digital Therm and Thermostat 576 CFG_CMD_ECHO * echo arguments 577 CFG_CMD_EEPROM * EEPROM read/write support 578 CFG_CMD_ELF * bootelf, bootvx 579 CFG_CMD_ENV saveenv 580 CFG_CMD_FDC * Floppy Disk Support 581 CFG_CMD_FAT * FAT partition support 582 CFG_CMD_FDOS * Dos diskette Support 583 CFG_CMD_FLASH flinfo, erase, protect 584 CFG_CMD_FPGA FPGA device initialization support 585 CFG_CMD_HWFLOW * RTS/CTS hw flow control 586 CFG_CMD_I2C * I2C serial bus support 587 CFG_CMD_IDE * IDE harddisk support 588 CFG_CMD_IMI iminfo 589 CFG_CMD_IMLS List all found images 590 CFG_CMD_IMMAP * IMMR dump support 591 CFG_CMD_IRQ * irqinfo 592 CFG_CMD_ITEST Integer/string test of 2 values 593 CFG_CMD_JFFS2 * JFFS2 Support 594 CFG_CMD_KGDB * kgdb 595 CFG_CMD_LOADB loadb 596 CFG_CMD_LOADS loads 597 CFG_CMD_MEMORY md, mm, nm, mw, cp, cmp, crc, base, 598 loop, loopw, mtest 599 CFG_CMD_MISC Misc functions like sleep etc 600 CFG_CMD_MMC * MMC memory mapped support 601 CFG_CMD_MII * MII utility commands 602 CFG_CMD_NAND * NAND support 603 CFG_CMD_NET bootp, tftpboot, rarpboot 604 CFG_CMD_PCI * pciinfo 605 CFG_CMD_PCMCIA * PCMCIA support 606 CFG_CMD_PING * send ICMP ECHO_REQUEST to network host 607 CFG_CMD_PORTIO * Port I/O 608 CFG_CMD_REGINFO * Register dump 609 CFG_CMD_RUN run command in env variable 610 CFG_CMD_SAVES * save S record dump 611 CFG_CMD_SCSI * SCSI Support 612 CFG_CMD_SDRAM * print SDRAM configuration information 613 CFG_CMD_SETGETDCR Support for DCR Register access (4xx only) 614 CFG_CMD_SPI * SPI serial bus support 615 CFG_CMD_USB * USB support 616 CFG_CMD_VFD * VFD support (TRAB) 617 CFG_CMD_BSP * Board SPecific functions 618 CFG_CMD_CDP * Cisco Discover Protocol support 619 ----------------------------------------------- 620 CFG_CMD_ALL all 621 622 CONFIG_CMD_DFL Default configuration; at the moment 623 this is includes all commands, except 624 the ones marked with "*" in the list 625 above. 626 627 If you don't define CONFIG_COMMANDS it defaults to 628 CONFIG_CMD_DFL in include/cmd_confdefs.h. A board can 629 override the default settings in the respective 630 include file. 631 632 EXAMPLE: If you want all functions except of network 633 support you can write: 634 635 #define CONFIG_COMMANDS (CFG_CMD_ALL & ~CFG_CMD_NET) 636 637 638 Note: Don't enable the "icache" and "dcache" commands 639 (configuration option CFG_CMD_CACHE) unless you know 640 what you (and your U-Boot users) are doing. Data 641 cache cannot be enabled on systems like the 8xx or 642 8260 (where accesses to the IMMR region must be 643 uncached), and it cannot be disabled on all other 644 systems where we (mis-) use the data cache to hold an 645 initial stack and some data. 646 647 648 XXX - this list needs to get updated! 649 650- Watchdog: 651 CONFIG_WATCHDOG 652 If this variable is defined, it enables watchdog 653 support. There must be support in the platform specific 654 code for a watchdog. For the 8xx and 8260 CPUs, the 655 SIU Watchdog feature is enabled in the SYPCR 656 register. 657 658- U-Boot Version: 659 CONFIG_VERSION_VARIABLE 660 If this variable is defined, an environment variable 661 named "ver" is created by U-Boot showing the U-Boot 662 version as printed by the "version" command. 663 This variable is readonly. 664 665- Real-Time Clock: 666 667 When CFG_CMD_DATE is selected, the type of the RTC 668 has to be selected, too. Define exactly one of the 669 following options: 670 671 CONFIG_RTC_MPC8xx - use internal RTC of MPC8xx 672 CONFIG_RTC_PCF8563 - use Philips PCF8563 RTC 673 CONFIG_RTC_MC146818 - use MC146818 RTC 674 CONFIG_RTC_DS1307 - use Maxim, Inc. DS1307 RTC 675 CONFIG_RTC_DS1337 - use Maxim, Inc. DS1337 RTC 676 CONFIG_RTC_DS1338 - use Maxim, Inc. DS1338 RTC 677 CONFIG_RTC_DS164x - use Dallas DS164x RTC 678 CONFIG_RTC_MAX6900 - use Maxim, Inc. MAX6900 RTC 679 680 Note that if the RTC uses I2C, then the I2C interface 681 must also be configured. See I2C Support, below. 682 683- Timestamp Support: 684 685 When CONFIG_TIMESTAMP is selected, the timestamp 686 (date and time) of an image is printed by image 687 commands like bootm or iminfo. This option is 688 automatically enabled when you select CFG_CMD_DATE . 689 690- Partition Support: 691 CONFIG_MAC_PARTITION and/or CONFIG_DOS_PARTITION 692 and/or CONFIG_ISO_PARTITION 693 694 If IDE or SCSI support is enabled (CFG_CMD_IDE or 695 CFG_CMD_SCSI) you must configure support for at least 696 one partition type as well. 697 698- IDE Reset method: 699 CONFIG_IDE_RESET_ROUTINE - this is defined in several 700 board configurations files but used nowhere! 701 702 CONFIG_IDE_RESET - is this is defined, IDE Reset will 703 be performed by calling the function 704 ide_set_reset(int reset) 705 which has to be defined in a board specific file 706 707- ATAPI Support: 708 CONFIG_ATAPI 709 710 Set this to enable ATAPI support. 711 712- LBA48 Support 713 CONFIG_LBA48 714 715 Set this to enable support for disks larger than 137GB 716 Also look at CFG_64BIT_LBA ,CFG_64BIT_VSPRINTF and CFG_64BIT_STRTOUL 717 Whithout these , LBA48 support uses 32bit variables and will 'only' 718 support disks up to 2.1TB. 719 720 CFG_64BIT_LBA: 721 When enabled, makes the IDE subsystem use 64bit sector addresses. 722 Default is 32bit. 723 724- SCSI Support: 725 At the moment only there is only support for the 726 SYM53C8XX SCSI controller; define 727 CONFIG_SCSI_SYM53C8XX to enable it. 728 729 CFG_SCSI_MAX_LUN [8], CFG_SCSI_MAX_SCSI_ID [7] and 730 CFG_SCSI_MAX_DEVICE [CFG_SCSI_MAX_SCSI_ID * 731 CFG_SCSI_MAX_LUN] can be adjusted to define the 732 maximum numbers of LUNs, SCSI ID's and target 733 devices. 734 CFG_SCSI_SYM53C8XX_CCF to fix clock timing (80Mhz) 735 736- NETWORK Support (PCI): 737 CONFIG_E1000 738 Support for Intel 8254x gigabit chips. 739 740 CONFIG_EEPRO100 741 Support for Intel 82557/82559/82559ER chips. 742 Optional CONFIG_EEPRO100_SROM_WRITE enables eeprom 743 write routine for first time initialisation. 744 745 CONFIG_TULIP 746 Support for Digital 2114x chips. 747 Optional CONFIG_TULIP_SELECT_MEDIA for board specific 748 modem chip initialisation (KS8761/QS6611). 749 750 CONFIG_NATSEMI 751 Support for National dp83815 chips. 752 753 CONFIG_NS8382X 754 Support for National dp8382[01] gigabit chips. 755 756- NETWORK Support (other): 757 758 CONFIG_DRIVER_LAN91C96 759 Support for SMSC's LAN91C96 chips. 760 761 CONFIG_LAN91C96_BASE 762 Define this to hold the physical address 763 of the LAN91C96's I/O space 764 765 CONFIG_LAN91C96_USE_32_BIT 766 Define this to enable 32 bit addressing 767 768 CONFIG_DRIVER_SMC91111 769 Support for SMSC's LAN91C111 chip 770 771 CONFIG_SMC91111_BASE 772 Define this to hold the physical address 773 of the device (I/O space) 774 775 CONFIG_SMC_USE_32_BIT 776 Define this if data bus is 32 bits 777 778 CONFIG_SMC_USE_IOFUNCS 779 Define this to use i/o functions instead of macros 780 (some hardware wont work with macros) 781 782- USB Support: 783 At the moment only the UHCI host controller is 784 supported (PIP405, MIP405, MPC5200); define 785 CONFIG_USB_UHCI to enable it. 786 define CONFIG_USB_KEYBOARD to enable the USB Keyboard 787 end define CONFIG_USB_STORAGE to enable the USB 788 storage devices. 789 Note: 790 Supported are USB Keyboards and USB Floppy drives 791 (TEAC FD-05PUB). 792 MPC5200 USB requires additional defines: 793 CONFIG_USB_CLOCK 794 for 528 MHz Clock: 0x0001bbbb 795 CONFIG_USB_CONFIG 796 for differential drivers: 0x00001000 797 for single ended drivers: 0x00005000 798 799 800- MMC Support: 801 The MMC controller on the Intel PXA is supported. To 802 enable this define CONFIG_MMC. The MMC can be 803 accessed from the boot prompt by mapping the device 804 to physical memory similar to flash. Command line is 805 enabled with CFG_CMD_MMC. The MMC driver also works with 806 the FAT fs. This is enabled with CFG_CMD_FAT. 807 808- Journaling Flash filesystem support: 809 CONFIG_JFFS2_NAND, CONFIG_JFFS2_NAND_OFF, CONFIG_JFFS2_NAND_SIZE, 810 CONFIG_JFFS2_NAND_DEV 811 Define these for a default partition on a NAND device 812 813 CFG_JFFS2_FIRST_SECTOR, 814 CFG_JFFS2_FIRST_BANK, CFG_JFFS2_NUM_BANKS 815 Define these for a default partition on a NOR device 816 817 CFG_JFFS_CUSTOM_PART 818 Define this to create an own partition. You have to provide a 819 function struct part_info* jffs2_part_info(int part_num) 820 821 If you define only one JFFS2 partition you may also want to 822 #define CFG_JFFS_SINGLE_PART 1 823 to disable the command chpart. This is the default when you 824 have not defined a custom partition 825 826- Keyboard Support: 827 CONFIG_ISA_KEYBOARD 828 829 Define this to enable standard (PC-Style) keyboard 830 support 831 832 CONFIG_I8042_KBD 833 Standard PC keyboard driver with US (is default) and 834 GERMAN key layout (switch via environment 'keymap=de') support. 835 Export function i8042_kbd_init, i8042_tstc and i8042_getc 836 for cfb_console. Supports cursor blinking. 837 838- Video support: 839 CONFIG_VIDEO 840 841 Define this to enable video support (for output to 842 video). 843 844 CONFIG_VIDEO_CT69000 845 846 Enable Chips & Technologies 69000 Video chip 847 848 CONFIG_VIDEO_SMI_LYNXEM 849 Enable Silicon Motion SMI 712/710/810 Video chip. The 850 video output is selected via environment 'videoout' 851 (1 = LCD and 2 = CRT). If videoout is undefined, CRT is 852 assumed. 853 854 For the CT69000 and SMI_LYNXEM drivers, videomode is 855 selected via environment 'videomode'. Two diferent ways 856 are possible: 857 - "videomode=num" 'num' is a standard LiLo mode numbers. 858 Following standard modes are supported (* is default): 859 860 Colors 640x480 800x600 1024x768 1152x864 1280x1024 861 -------------+--------------------------------------------- 862 8 bits | 0x301* 0x303 0x305 0x161 0x307 863 15 bits | 0x310 0x313 0x316 0x162 0x319 864 16 bits | 0x311 0x314 0x317 0x163 0x31A 865 24 bits | 0x312 0x315 0x318 ? 0x31B 866 -------------+--------------------------------------------- 867 (i.e. setenv videomode 317; saveenv; reset;) 868 869 - "videomode=bootargs" all the video parameters are parsed 870 from the bootargs. (See drivers/videomodes.c) 871 872 873 CONFIG_VIDEO_SED13806 874 Enable Epson SED13806 driver. This driver supports 8bpp 875 and 16bpp modes defined by CONFIG_VIDEO_SED13806_8BPP 876 or CONFIG_VIDEO_SED13806_16BPP 877 878- Keyboard Support: 879 CONFIG_KEYBOARD 880 881 Define this to enable a custom keyboard support. 882 This simply calls drv_keyboard_init() which must be 883 defined in your board-specific files. 884 The only board using this so far is RBC823. 885 886- LCD Support: CONFIG_LCD 887 888 Define this to enable LCD support (for output to LCD 889 display); also select one of the supported displays 890 by defining one of these: 891 892 CONFIG_NEC_NL6448AC33: 893 894 NEC NL6448AC33-18. Active, color, single scan. 895 896 CONFIG_NEC_NL6448BC20 897 898 NEC NL6448BC20-08. 6.5", 640x480. 899 Active, color, single scan. 900 901 CONFIG_NEC_NL6448BC33_54 902 903 NEC NL6448BC33-54. 10.4", 640x480. 904 Active, color, single scan. 905 906 CONFIG_SHARP_16x9 907 908 Sharp 320x240. Active, color, single scan. 909 It isn't 16x9, and I am not sure what it is. 910 911 CONFIG_SHARP_LQ64D341 912 913 Sharp LQ64D341 display, 640x480. 914 Active, color, single scan. 915 916 CONFIG_HLD1045 917 918 HLD1045 display, 640x480. 919 Active, color, single scan. 920 921 CONFIG_OPTREX_BW 922 923 Optrex CBL50840-2 NF-FW 99 22 M5 924 or 925 Hitachi LMG6912RPFC-00T 926 or 927 Hitachi SP14Q002 928 929 320x240. Black & white. 930 931 Normally display is black on white background; define 932 CFG_WHITE_ON_BLACK to get it inverted. 933 934- Splash Screen Support: CONFIG_SPLASH_SCREEN 935 936 If this option is set, the environment is checked for 937 a variable "splashimage". If found, the usual display 938 of logo, copyright and system information on the LCD 939 is suppressed and the BMP image at the address 940 specified in "splashimage" is loaded instead. The 941 console is redirected to the "nulldev", too. This 942 allows for a "silent" boot where a splash screen is 943 loaded very quickly after power-on. 944 945- Compression support: 946 CONFIG_BZIP2 947 948 If this option is set, support for bzip2 compressed 949 images is included. If not, only uncompressed and gzip 950 compressed images are supported. 951 952 NOTE: the bzip2 algorithm requires a lot of RAM, so 953 the malloc area (as defined by CFG_MALLOC_LEN) should 954 be at least 4MB. 955 956- MII/PHY support: 957 CONFIG_PHY_ADDR 958 959 The address of PHY on MII bus. 960 961 CONFIG_PHY_CLOCK_FREQ (ppc4xx) 962 963 The clock frequency of the MII bus 964 965 CONFIG_PHY_GIGE 966 967 If this option is set, support for speed/duplex 968 detection of Gigabit PHY is included. 969 970 CONFIG_PHY_RESET_DELAY 971 972 Some PHY like Intel LXT971A need extra delay after 973 reset before any MII register access is possible. 974 For such PHY, set this option to the usec delay 975 required. (minimum 300usec for LXT971A) 976 977 CONFIG_PHY_CMD_DELAY (ppc4xx) 978 979 Some PHY like Intel LXT971A need extra delay after 980 command issued before MII status register can be read 981 982- Ethernet address: 983 CONFIG_ETHADDR 984 CONFIG_ETH2ADDR 985 CONFIG_ETH3ADDR 986 987 Define a default value for ethernet address to use 988 for the respective ethernet interface, in case this 989 is not determined automatically. 990 991- IP address: 992 CONFIG_IPADDR 993 994 Define a default value for the IP address to use for 995 the default ethernet interface, in case this is not 996 determined through e.g. bootp. 997 998- Server IP address: 999 CONFIG_SERVERIP 1000 1001 Defines a default value for theIP address of a TFTP 1002 server to contact when using the "tftboot" command. 1003 1004- BOOTP Recovery Mode: 1005 CONFIG_BOOTP_RANDOM_DELAY 1006 1007 If you have many targets in a network that try to 1008 boot using BOOTP, you may want to avoid that all 1009 systems send out BOOTP requests at precisely the same 1010 moment (which would happen for instance at recovery 1011 from a power failure, when all systems will try to 1012 boot, thus flooding the BOOTP server. Defining 1013 CONFIG_BOOTP_RANDOM_DELAY causes a random delay to be 1014 inserted before sending out BOOTP requests. The 1015 following delays are insterted then: 1016 1017 1st BOOTP request: delay 0 ... 1 sec 1018 2nd BOOTP request: delay 0 ... 2 sec 1019 3rd BOOTP request: delay 0 ... 4 sec 1020 4th and following 1021 BOOTP requests: delay 0 ... 8 sec 1022 1023- DHCP Advanced Options: 1024 CONFIG_BOOTP_MASK 1025 1026 You can fine tune the DHCP functionality by adding 1027 these flags to the CONFIG_BOOTP_MASK define: 1028 1029 CONFIG_BOOTP_DNS2 - If a DHCP client requests the DNS 1030 serverip from a DHCP server, it is possible that more 1031 than one DNS serverip is offered to the client. 1032 If CONFIG_BOOTP_DNS2 is enabled, the secondary DNS 1033 serverip will be stored in the additional environment 1034 variable "dnsip2". The first DNS serverip is always 1035 stored in the variable "dnsip", when CONFIG_BOOTP_DNS 1036 is added to the CONFIG_BOOTP_MASK. 1037 1038 CONFIG_BOOTP_SEND_HOSTNAME - Some DHCP servers are capable 1039 to do a dynamic update of a DNS server. To do this, they 1040 need the hostname of the DHCP requester. 1041 If CONFIG_BOOP_SEND_HOSTNAME is added to the 1042 CONFIG_BOOTP_MASK, the content of the "hostname" 1043 environment variable is passed as option 12 to 1044 the DHCP server. 1045 1046 - CDP Options: 1047 CONFIG_CDP_DEVICE_ID 1048 1049 The device id used in CDP trigger frames. 1050 1051 CONFIG_CDP_DEVICE_ID_PREFIX 1052 1053 A two character string which is prefixed to the MAC address 1054 of the device. 1055 1056 CONFIG_CDP_PORT_ID 1057 1058 A printf format string which contains the ascii name of 1059 the port. Normally is set to "eth%d" which sets 1060 eth0 for the first ethernet, eth1 for the second etc. 1061 1062 CONFIG_CDP_CAPABILITIES 1063 1064 A 32bit integer which indicates the device capabilities; 1065 0x00000010 for a normal host which does not forwards. 1066 1067 CONFIG_CDP_VERSION 1068 1069 An ascii string containing the version of the software. 1070 1071 CONFIG_CDP_PLATFORM 1072 1073 An ascii string containing the name of the platform. 1074 1075 CONFIG_CDP_TRIGGER 1076 1077 A 32bit integer sent on the trigger. 1078 1079 CONFIG_CDP_POWER_CONSUMPTION 1080 1081 A 16bit integer containing the power consumption of the 1082 device in .1 of milliwatts. 1083 1084 CONFIG_CDP_APPLIANCE_VLAN_TYPE 1085 1086 A byte containing the id of the VLAN. 1087 1088- Status LED: CONFIG_STATUS_LED 1089 1090 Several configurations allow to display the current 1091 status using a LED. For instance, the LED will blink 1092 fast while running U-Boot code, stop blinking as 1093 soon as a reply to a BOOTP request was received, and 1094 start blinking slow once the Linux kernel is running 1095 (supported by a status LED driver in the Linux 1096 kernel). Defining CONFIG_STATUS_LED enables this 1097 feature in U-Boot. 1098 1099- CAN Support: CONFIG_CAN_DRIVER 1100 1101 Defining CONFIG_CAN_DRIVER enables CAN driver support 1102 on those systems that support this (optional) 1103 feature, like the TQM8xxL modules. 1104 1105- I2C Support: CONFIG_HARD_I2C | CONFIG_SOFT_I2C 1106 1107 These enable I2C serial bus commands. Defining either of 1108 (but not both of) CONFIG_HARD_I2C or CONFIG_SOFT_I2C will 1109 include the appropriate I2C driver for the selected cpu. 1110 1111 This will allow you to use i2c commands at the u-boot 1112 command line (as long as you set CFG_CMD_I2C in 1113 CONFIG_COMMANDS) and communicate with i2c based realtime 1114 clock chips. See common/cmd_i2c.c for a description of the 1115 command line interface. 1116 1117 CONFIG_HARD_I2C selects the CPM hardware driver for I2C. 1118 1119 CONFIG_SOFT_I2C configures u-boot to use a software (aka 1120 bit-banging) driver instead of CPM or similar hardware 1121 support for I2C. 1122 1123 There are several other quantities that must also be 1124 defined when you define CONFIG_HARD_I2C or CONFIG_SOFT_I2C. 1125 1126 In both cases you will need to define CFG_I2C_SPEED 1127 to be the frequency (in Hz) at which you wish your i2c bus 1128 to run and CFG_I2C_SLAVE to be the address of this node (ie 1129 the cpu's i2c node address). 1130 1131 Now, the u-boot i2c code for the mpc8xx (cpu/mpc8xx/i2c.c) 1132 sets the cpu up as a master node and so its address should 1133 therefore be cleared to 0 (See, eg, MPC823e User's Manual 1134 p.16-473). So, set CFG_I2C_SLAVE to 0. 1135 1136 That's all that's required for CONFIG_HARD_I2C. 1137 1138 If you use the software i2c interface (CONFIG_SOFT_I2C) 1139 then the following macros need to be defined (examples are 1140 from include/configs/lwmon.h): 1141 1142 I2C_INIT 1143 1144 (Optional). Any commands necessary to enable the I2C 1145 controller or configure ports. 1146 1147 eg: #define I2C_INIT (immr->im_cpm.cp_pbdir |= PB_SCL) 1148 1149 I2C_PORT 1150 1151 (Only for MPC8260 CPU). The I/O port to use (the code 1152 assumes both bits are on the same port). Valid values 1153 are 0..3 for ports A..D. 1154 1155 I2C_ACTIVE 1156 1157 The code necessary to make the I2C data line active 1158 (driven). If the data line is open collector, this 1159 define can be null. 1160 1161 eg: #define I2C_ACTIVE (immr->im_cpm.cp_pbdir |= PB_SDA) 1162 1163 I2C_TRISTATE 1164 1165 The code necessary to make the I2C data line tri-stated 1166 (inactive). If the data line is open collector, this 1167 define can be null. 1168 1169 eg: #define I2C_TRISTATE (immr->im_cpm.cp_pbdir &= ~PB_SDA) 1170 1171 I2C_READ 1172 1173 Code that returns TRUE if the I2C data line is high, 1174 FALSE if it is low. 1175 1176 eg: #define I2C_READ ((immr->im_cpm.cp_pbdat & PB_SDA) != 0) 1177 1178 I2C_SDA(bit) 1179 1180 If <bit> is TRUE, sets the I2C data line high. If it 1181 is FALSE, it clears it (low). 1182 1183 eg: #define I2C_SDA(bit) \ 1184 if(bit) immr->im_cpm.cp_pbdat |= PB_SDA; \ 1185 else immr->im_cpm.cp_pbdat &= ~PB_SDA 1186 1187 I2C_SCL(bit) 1188 1189 If <bit> is TRUE, sets the I2C clock line high. If it 1190 is FALSE, it clears it (low). 1191 1192 eg: #define I2C_SCL(bit) \ 1193 if(bit) immr->im_cpm.cp_pbdat |= PB_SCL; \ 1194 else immr->im_cpm.cp_pbdat &= ~PB_SCL 1195 1196 I2C_DELAY 1197 1198 This delay is invoked four times per clock cycle so this 1199 controls the rate of data transfer. The data rate thus 1200 is 1 / (I2C_DELAY * 4). Often defined to be something 1201 like: 1202 1203 #define I2C_DELAY udelay(2) 1204 1205 CFG_I2C_INIT_BOARD 1206 1207 When a board is reset during an i2c bus transfer 1208 chips might think that the current transfer is still 1209 in progress. On some boards it is possible to access 1210 the i2c SCLK line directly, either by using the 1211 processor pin as a GPIO or by having a second pin 1212 connected to the bus. If this option is defined a 1213 custom i2c_init_board() routine in boards/xxx/board.c 1214 is run early in the boot sequence. 1215 1216 CONFIG_I2CFAST (PPC405GP|PPC405EP only) 1217 1218 This option enables configuration of bi_iic_fast[] flags 1219 in u-boot bd_info structure based on u-boot environment 1220 variable "i2cfast". (see also i2cfast) 1221 1222- SPI Support: CONFIG_SPI 1223 1224 Enables SPI driver (so far only tested with 1225 SPI EEPROM, also an instance works with Crystal A/D and 1226 D/As on the SACSng board) 1227 1228 CONFIG_SPI_X 1229 1230 Enables extended (16-bit) SPI EEPROM addressing. 1231 (symmetrical to CONFIG_I2C_X) 1232 1233 CONFIG_SOFT_SPI 1234 1235 Enables a software (bit-bang) SPI driver rather than 1236 using hardware support. This is a general purpose 1237 driver that only requires three general I/O port pins 1238 (two outputs, one input) to function. If this is 1239 defined, the board configuration must define several 1240 SPI configuration items (port pins to use, etc). For 1241 an example, see include/configs/sacsng.h. 1242 1243- FPGA Support: CONFIG_FPGA_COUNT 1244 1245 Specify the number of FPGA devices to support. 1246 1247 CONFIG_FPGA 1248 1249 Used to specify the types of FPGA devices. For example, 1250 #define CONFIG_FPGA CFG_XILINX_VIRTEX2 1251 1252 CFG_FPGA_PROG_FEEDBACK 1253 1254 Enable printing of hash marks during FPGA configuration. 1255 1256 CFG_FPGA_CHECK_BUSY 1257 1258 Enable checks on FPGA configuration interface busy 1259 status by the configuration function. This option 1260 will require a board or device specific function to 1261 be written. 1262 1263 CONFIG_FPGA_DELAY 1264 1265 If defined, a function that provides delays in the FPGA 1266 configuration driver. 1267 1268 CFG_FPGA_CHECK_CTRLC 1269 Allow Control-C to interrupt FPGA configuration 1270 1271 CFG_FPGA_CHECK_ERROR 1272 1273 Check for configuration errors during FPGA bitfile 1274 loading. For example, abort during Virtex II 1275 configuration if the INIT_B line goes low (which 1276 indicated a CRC error). 1277 1278 CFG_FPGA_WAIT_INIT 1279 1280 Maximum time to wait for the INIT_B line to deassert 1281 after PROB_B has been deasserted during a Virtex II 1282 FPGA configuration sequence. The default time is 500 1283 mS. 1284 1285 CFG_FPGA_WAIT_BUSY 1286 1287 Maximum time to wait for BUSY to deassert during 1288 Virtex II FPGA configuration. The default is 5 mS. 1289 1290 CFG_FPGA_WAIT_CONFIG 1291 1292 Time to wait after FPGA configuration. The default is 1293 200 mS. 1294 1295- Configuration Management: 1296 CONFIG_IDENT_STRING 1297 1298 If defined, this string will be added to the U-Boot 1299 version information (U_BOOT_VERSION) 1300 1301- Vendor Parameter Protection: 1302 1303 U-Boot considers the values of the environment 1304 variables "serial#" (Board Serial Number) and 1305 "ethaddr" (Ethernet Address) to be parameters that 1306 are set once by the board vendor / manufacturer, and 1307 protects these variables from casual modification by 1308 the user. Once set, these variables are read-only, 1309 and write or delete attempts are rejected. You can 1310 change this behviour: 1311 1312 If CONFIG_ENV_OVERWRITE is #defined in your config 1313 file, the write protection for vendor parameters is 1314 completely disabled. Anybody can change or delete 1315 these parameters. 1316 1317 Alternatively, if you #define _both_ CONFIG_ETHADDR 1318 _and_ CONFIG_OVERWRITE_ETHADDR_ONCE, a default 1319 ethernet address is installed in the environment, 1320 which can be changed exactly ONCE by the user. [The 1321 serial# is unaffected by this, i. e. it remains 1322 read-only.] 1323 1324- Protected RAM: 1325 CONFIG_PRAM 1326 1327 Define this variable to enable the reservation of 1328 "protected RAM", i. e. RAM which is not overwritten 1329 by U-Boot. Define CONFIG_PRAM to hold the number of 1330 kB you want to reserve for pRAM. You can overwrite 1331 this default value by defining an environment 1332 variable "pram" to the number of kB you want to 1333 reserve. Note that the board info structure will 1334 still show the full amount of RAM. If pRAM is 1335 reserved, a new environment variable "mem" will 1336 automatically be defined to hold the amount of 1337 remaining RAM in a form that can be passed as boot 1338 argument to Linux, for instance like that: 1339 1340 setenv bootargs ... mem=\$(mem) 1341 saveenv 1342 1343 This way you can tell Linux not to use this memory, 1344 either, which results in a memory region that will 1345 not be affected by reboots. 1346 1347 *WARNING* If your board configuration uses automatic 1348 detection of the RAM size, you must make sure that 1349 this memory test is non-destructive. So far, the 1350 following board configurations are known to be 1351 "pRAM-clean": 1352 1353 ETX094, IVMS8, IVML24, SPD8xx, TQM8xxL, 1354 HERMES, IP860, RPXlite, LWMON, LANTEC, 1355 PCU_E, FLAGADM, TQM8260 1356 1357- Error Recovery: 1358 CONFIG_PANIC_HANG 1359 1360 Define this variable to stop the system in case of a 1361 fatal error, so that you have to reset it manually. 1362 This is probably NOT a good idea for an embedded 1363 system where you want to system to reboot 1364 automatically as fast as possible, but it may be 1365 useful during development since you can try to debug 1366 the conditions that lead to the situation. 1367 1368 CONFIG_NET_RETRY_COUNT 1369 1370 This variable defines the number of retries for 1371 network operations like ARP, RARP, TFTP, or BOOTP 1372 before giving up the operation. If not defined, a 1373 default value of 5 is used. 1374 1375- Command Interpreter: 1376 CFG_AUTO_COMPLETE 1377 1378 Enable auto completion of commands using TAB. 1379 1380 CFG_HUSH_PARSER 1381 1382 Define this variable to enable the "hush" shell (from 1383 Busybox) as command line interpreter, thus enabling 1384 powerful command line syntax like 1385 if...then...else...fi conditionals or `&&' and '||' 1386 constructs ("shell scripts"). 1387 1388 If undefined, you get the old, much simpler behaviour 1389 with a somewhat smaller memory footprint. 1390 1391 1392 CFG_PROMPT_HUSH_PS2 1393 1394 This defines the secondary prompt string, which is 1395 printed when the command interpreter needs more input 1396 to complete a command. Usually "> ". 1397 1398 Note: 1399 1400 In the current implementation, the local variables 1401 space and global environment variables space are 1402 separated. Local variables are those you define by 1403 simply typing `name=value'. To access a local 1404 variable later on, you have write `$name' or 1405 `${name}'; to execute the contents of a variable 1406 directly type `$name' at the command prompt. 1407 1408 Global environment variables are those you use 1409 setenv/printenv to work with. To run a command stored 1410 in such a variable, you need to use the run command, 1411 and you must not use the '$' sign to access them. 1412 1413 To store commands and special characters in a 1414 variable, please use double quotation marks 1415 surrounding the whole text of the variable, instead 1416 of the backslashes before semicolons and special 1417 symbols. 1418 1419- Default Environment: 1420 CONFIG_EXTRA_ENV_SETTINGS 1421 1422 Define this to contain any number of null terminated 1423 strings (variable = value pairs) that will be part of 1424 the default environment compiled into the boot image. 1425 1426 For example, place something like this in your 1427 board's config file: 1428 1429 #define CONFIG_EXTRA_ENV_SETTINGS \ 1430 "myvar1=value1\0" \ 1431 "myvar2=value2\0" 1432 1433 Warning: This method is based on knowledge about the 1434 internal format how the environment is stored by the 1435 U-Boot code. This is NOT an official, exported 1436 interface! Although it is unlikely that this format 1437 will change soon, there is no guarantee either. 1438 You better know what you are doing here. 1439 1440 Note: overly (ab)use of the default environment is 1441 discouraged. Make sure to check other ways to preset 1442 the environment like the autoscript function or the 1443 boot command first. 1444 1445- DataFlash Support: 1446 CONFIG_HAS_DATAFLASH 1447 1448 Defining this option enables DataFlash features and 1449 allows to read/write in Dataflash via the standard 1450 commands cp, md... 1451 1452- SystemACE Support: 1453 CONFIG_SYSTEMACE 1454 1455 Adding this option adds support for Xilinx SystemACE 1456 chips attached via some sort of local bus. The address 1457 of the chip must alsh be defined in the 1458 CFG_SYSTEMACE_BASE macro. For example: 1459 1460 #define CONFIG_SYSTEMACE 1461 #define CFG_SYSTEMACE_BASE 0xf0000000 1462 1463 When SystemACE support is added, the "ace" device type 1464 becomes available to the fat commands, i.e. fatls. 1465 1466- Show boot progress: 1467 CONFIG_SHOW_BOOT_PROGRESS 1468 1469 Defining this option allows to add some board- 1470 specific code (calling a user-provided function 1471 "show_boot_progress(int)") that enables you to show 1472 the system's boot progress on some display (for 1473 example, some LED's) on your board. At the moment, 1474 the following checkpoints are implemented: 1475 1476 Arg Where When 1477 1 common/cmd_bootm.c before attempting to boot an image 1478 -1 common/cmd_bootm.c Image header has bad magic number 1479 2 common/cmd_bootm.c Image header has correct magic number 1480 -2 common/cmd_bootm.c Image header has bad checksum 1481 3 common/cmd_bootm.c Image header has correct checksum 1482 -3 common/cmd_bootm.c Image data has bad checksum 1483 4 common/cmd_bootm.c Image data has correct checksum 1484 -4 common/cmd_bootm.c Image is for unsupported architecture 1485 5 common/cmd_bootm.c Architecture check OK 1486 -5 common/cmd_bootm.c Wrong Image Type (not kernel, multi, standalone) 1487 6 common/cmd_bootm.c Image Type check OK 1488 -6 common/cmd_bootm.c gunzip uncompression error 1489 -7 common/cmd_bootm.c Unimplemented compression type 1490 7 common/cmd_bootm.c Uncompression OK 1491 -8 common/cmd_bootm.c Wrong Image Type (not kernel, multi, standalone) 1492 8 common/cmd_bootm.c Image Type check OK 1493 -9 common/cmd_bootm.c Unsupported OS (not Linux, BSD, VxWorks, QNX) 1494 9 common/cmd_bootm.c Start initial ramdisk verification 1495 -10 common/cmd_bootm.c Ramdisk header has bad magic number 1496 -11 common/cmd_bootm.c Ramdisk header has bad checksum 1497 10 common/cmd_bootm.c Ramdisk header is OK 1498 -12 common/cmd_bootm.c Ramdisk data has bad checksum 1499 11 common/cmd_bootm.c Ramdisk data has correct checksum 1500 12 common/cmd_bootm.c Ramdisk verification complete, start loading 1501 -13 common/cmd_bootm.c Wrong Image Type (not PPC Linux Ramdisk) 1502 13 common/cmd_bootm.c Start multifile image verification 1503 14 common/cmd_bootm.c No initial ramdisk, no multifile, continue. 1504 15 common/cmd_bootm.c All preparation done, transferring control to OS 1505 1506 -30 lib_ppc/board.c Fatal error, hang the system 1507 -31 post/post.c POST test failed, detected by post_output_backlog() 1508 -32 post/post.c POST test failed, detected by post_run_single() 1509 1510 -1 common/cmd_doc.c Bad usage of "doc" command 1511 -1 common/cmd_doc.c No boot device 1512 -1 common/cmd_doc.c Unknown Chip ID on boot device 1513 -1 common/cmd_doc.c Read Error on boot device 1514 -1 common/cmd_doc.c Image header has bad magic number 1515 1516 -1 common/cmd_ide.c Bad usage of "ide" command 1517 -1 common/cmd_ide.c No boot device 1518 -1 common/cmd_ide.c Unknown boot device 1519 -1 common/cmd_ide.c Unknown partition table 1520 -1 common/cmd_ide.c Invalid partition type 1521 -1 common/cmd_ide.c Read Error on boot device 1522 -1 common/cmd_ide.c Image header has bad magic number 1523 1524 -1 common/cmd_nand.c Bad usage of "nand" command 1525 -1 common/cmd_nand.c No boot device 1526 -1 common/cmd_nand.c Unknown Chip ID on boot device 1527 -1 common/cmd_nand.c Read Error on boot device 1528 -1 common/cmd_nand.c Image header has bad magic number 1529 1530 -1 common/env_common.c Environment has a bad CRC, using default 1531 1532 1533Modem Support: 1534-------------- 1535 1536[so far only for SMDK2400 and TRAB boards] 1537 1538- Modem support endable: 1539 CONFIG_MODEM_SUPPORT 1540 1541- RTS/CTS Flow control enable: 1542 CONFIG_HWFLOW 1543 1544- Modem debug support: 1545 CONFIG_MODEM_SUPPORT_DEBUG 1546 1547 Enables debugging stuff (char screen[1024], dbg()) 1548 for modem support. Useful only with BDI2000. 1549 1550- Interrupt support (PPC): 1551 1552 There are common interrupt_init() and timer_interrupt() 1553 for all PPC archs. interrupt_init() calls interrupt_init_cpu() 1554 for cpu specific initialization. interrupt_init_cpu() 1555 should set decrementer_count to appropriate value. If 1556 cpu resets decrementer automatically after interrupt 1557 (ppc4xx) it should set decrementer_count to zero. 1558 timer_interrupt() calls timer_interrupt_cpu() for cpu 1559 specific handling. If board has watchdog / status_led 1560 / other_activity_monitor it works automatically from 1561 general timer_interrupt(). 1562 1563- General: 1564 1565 In the target system modem support is enabled when a 1566 specific key (key combination) is pressed during 1567 power-on. Otherwise U-Boot will boot normally 1568 (autoboot). The key_pressed() fuction is called from 1569 board_init(). Currently key_pressed() is a dummy 1570 function, returning 1 and thus enabling modem 1571 initialization. 1572 1573 If there are no modem init strings in the 1574 environment, U-Boot proceed to autoboot; the 1575 previous output (banner, info printfs) will be 1576 supressed, though. 1577 1578 See also: doc/README.Modem 1579 1580 1581Configuration Settings: 1582----------------------- 1583 1584- CFG_LONGHELP: Defined when you want long help messages included; 1585 undefine this when you're short of memory. 1586 1587- CFG_PROMPT: This is what U-Boot prints on the console to 1588 prompt for user input. 1589 1590- CFG_CBSIZE: Buffer size for input from the Console 1591 1592- CFG_PBSIZE: Buffer size for Console output 1593 1594- CFG_MAXARGS: max. Number of arguments accepted for monitor commands 1595 1596- CFG_BARGSIZE: Buffer size for Boot Arguments which are passed to 1597 the application (usually a Linux kernel) when it is 1598 booted 1599 1600- CFG_BAUDRATE_TABLE: 1601 List of legal baudrate settings for this board. 1602 1603- CFG_CONSOLE_INFO_QUIET 1604 Suppress display of console information at boot. 1605 1606- CFG_CONSOLE_IS_IN_ENV 1607 If the board specific function 1608 extern int overwrite_console (void); 1609 returns 1, the stdin, stderr and stdout are switched to the 1610 serial port, else the settings in the environment are used. 1611 1612- CFG_CONSOLE_OVERWRITE_ROUTINE 1613 Enable the call to overwrite_console(). 1614 1615- CFG_CONSOLE_ENV_OVERWRITE 1616 Enable overwrite of previous console environment settings. 1617 1618- CFG_MEMTEST_START, CFG_MEMTEST_END: 1619 Begin and End addresses of the area used by the 1620 simple memory test. 1621 1622- CFG_ALT_MEMTEST: 1623 Enable an alternate, more extensive memory test. 1624 1625- CFG_MEMTEST_SCRATCH: 1626 Scratch address used by the alternate memory test 1627 You only need to set this if address zero isn't writeable 1628 1629- CFG_TFTP_LOADADDR: 1630 Default load address for network file downloads 1631 1632- CFG_LOADS_BAUD_CHANGE: 1633 Enable temporary baudrate change while serial download 1634 1635- CFG_SDRAM_BASE: 1636 Physical start address of SDRAM. _Must_ be 0 here. 1637 1638- CFG_MBIO_BASE: 1639 Physical start address of Motherboard I/O (if using a 1640 Cogent motherboard) 1641 1642- CFG_FLASH_BASE: 1643 Physical start address of Flash memory. 1644 1645- CFG_MONITOR_BASE: 1646 Physical start address of boot monitor code (set by 1647 make config files to be same as the text base address 1648 (TEXT_BASE) used when linking) - same as 1649 CFG_FLASH_BASE when booting from flash. 1650 1651- CFG_MONITOR_LEN: 1652 Size of memory reserved for monitor code, used to 1653 determine _at_compile_time_ (!) if the environment is 1654 embedded within the U-Boot image, or in a separate 1655 flash sector. 1656 1657- CFG_MALLOC_LEN: 1658 Size of DRAM reserved for malloc() use. 1659 1660- CFG_BOOTMAPSZ: 1661 Maximum size of memory mapped by the startup code of 1662 the Linux kernel; all data that must be processed by 1663 the Linux kernel (bd_info, boot arguments, eventually 1664 initrd image) must be put below this limit. 1665 1666- CFG_MAX_FLASH_BANKS: 1667 Max number of Flash memory banks 1668 1669- CFG_MAX_FLASH_SECT: 1670 Max number of sectors on a Flash chip 1671 1672- CFG_FLASH_ERASE_TOUT: 1673 Timeout for Flash erase operations (in ms) 1674 1675- CFG_FLASH_WRITE_TOUT: 1676 Timeout for Flash write operations (in ms) 1677 1678- CFG_FLASH_LOCK_TOUT 1679 Timeout for Flash set sector lock bit operation (in ms) 1680 1681- CFG_FLASH_UNLOCK_TOUT 1682 Timeout for Flash clear lock bits operation (in ms) 1683 1684- CFG_FLASH_PROTECTION 1685 If defined, hardware flash sectors protection is used 1686 instead of U-Boot software protection. 1687 1688- CFG_DIRECT_FLASH_TFTP: 1689 1690 Enable TFTP transfers directly to flash memory; 1691 without this option such a download has to be 1692 performed in two steps: (1) download to RAM, and (2) 1693 copy from RAM to flash. 1694 1695 The two-step approach is usually more reliable, since 1696 you can check if the download worked before you erase 1697 the flash, but in some situations (when sytem RAM is 1698 too limited to allow for a tempory copy of the 1699 downloaded image) this option may be very useful. 1700 1701- CFG_FLASH_CFI: 1702 Define if the flash driver uses extra elements in the 1703 common flash structure for storing flash geometry. 1704 1705- CFG_FLASH_CFI_DRIVER 1706 This option also enables the building of the cfi_flash driver 1707 in the drivers directory 1708 1709- CFG_RX_ETH_BUFFER: 1710 Defines the number of ethernet receive buffers. On some 1711 ethernet controllers it is recommended to set this value 1712 to 8 or even higher (EEPRO100 or 405 EMAC), since all 1713 buffers can be full shortly after enabling the interface 1714 on high ethernet traffic. 1715 Defaults to 4 if not defined. 1716 1717The following definitions that deal with the placement and management 1718of environment data (variable area); in general, we support the 1719following configurations: 1720 1721- CFG_ENV_IS_IN_FLASH: 1722 1723 Define this if the environment is in flash memory. 1724 1725 a) The environment occupies one whole flash sector, which is 1726 "embedded" in the text segment with the U-Boot code. This 1727 happens usually with "bottom boot sector" or "top boot 1728 sector" type flash chips, which have several smaller 1729 sectors at the start or the end. For instance, such a 1730 layout can have sector sizes of 8, 2x4, 16, Nx32 kB. In 1731 such a case you would place the environment in one of the 1732 4 kB sectors - with U-Boot code before and after it. With 1733 "top boot sector" type flash chips, you would put the 1734 environment in one of the last sectors, leaving a gap 1735 between U-Boot and the environment. 1736 1737 - CFG_ENV_OFFSET: 1738 1739 Offset of environment data (variable area) to the 1740 beginning of flash memory; for instance, with bottom boot 1741 type flash chips the second sector can be used: the offset 1742 for this sector is given here. 1743 1744 CFG_ENV_OFFSET is used relative to CFG_FLASH_BASE. 1745 1746 - CFG_ENV_ADDR: 1747 1748 This is just another way to specify the start address of 1749 the flash sector containing the environment (instead of 1750 CFG_ENV_OFFSET). 1751 1752 - CFG_ENV_SECT_SIZE: 1753 1754 Size of the sector containing the environment. 1755 1756 1757 b) Sometimes flash chips have few, equal sized, BIG sectors. 1758 In such a case you don't want to spend a whole sector for 1759 the environment. 1760 1761 - CFG_ENV_SIZE: 1762 1763 If you use this in combination with CFG_ENV_IS_IN_FLASH 1764 and CFG_ENV_SECT_SIZE, you can specify to use only a part 1765 of this flash sector for the environment. This saves 1766 memory for the RAM copy of the environment. 1767 1768 It may also save flash memory if you decide to use this 1769 when your environment is "embedded" within U-Boot code, 1770 since then the remainder of the flash sector could be used 1771 for U-Boot code. It should be pointed out that this is 1772 STRONGLY DISCOURAGED from a robustness point of view: 1773 updating the environment in flash makes it always 1774 necessary to erase the WHOLE sector. If something goes 1775 wrong before the contents has been restored from a copy in 1776 RAM, your target system will be dead. 1777 1778 - CFG_ENV_ADDR_REDUND 1779 CFG_ENV_SIZE_REDUND 1780 1781 These settings describe a second storage area used to hold 1782 a redundand copy of the environment data, so that there is 1783 a valid backup copy in case there is a power failure during 1784 a "saveenv" operation. 1785 1786BE CAREFUL! Any changes to the flash layout, and some changes to the 1787source code will make it necessary to adapt <board>/u-boot.lds* 1788accordingly! 1789 1790 1791- CFG_ENV_IS_IN_NVRAM: 1792 1793 Define this if you have some non-volatile memory device 1794 (NVRAM, battery buffered SRAM) which you want to use for the 1795 environment. 1796 1797 - CFG_ENV_ADDR: 1798 - CFG_ENV_SIZE: 1799 1800 These two #defines are used to determin the memory area you 1801 want to use for environment. It is assumed that this memory 1802 can just be read and written to, without any special 1803 provision. 1804 1805BE CAREFUL! The first access to the environment happens quite early 1806in U-Boot initalization (when we try to get the setting of for the 1807console baudrate). You *MUST* have mappend your NVRAM area then, or 1808U-Boot will hang. 1809 1810Please note that even with NVRAM we still use a copy of the 1811environment in RAM: we could work on NVRAM directly, but we want to 1812keep settings there always unmodified except somebody uses "saveenv" 1813to save the current settings. 1814 1815 1816- CFG_ENV_IS_IN_EEPROM: 1817 1818 Use this if you have an EEPROM or similar serial access 1819 device and a driver for it. 1820 1821 - CFG_ENV_OFFSET: 1822 - CFG_ENV_SIZE: 1823 1824 These two #defines specify the offset and size of the 1825 environment area within the total memory of your EEPROM. 1826 1827 - CFG_I2C_EEPROM_ADDR: 1828 If defined, specified the chip address of the EEPROM device. 1829 The default address is zero. 1830 1831 - CFG_EEPROM_PAGE_WRITE_BITS: 1832 If defined, the number of bits used to address bytes in a 1833 single page in the EEPROM device. A 64 byte page, for example 1834 would require six bits. 1835 1836 - CFG_EEPROM_PAGE_WRITE_DELAY_MS: 1837 If defined, the number of milliseconds to delay between 1838 page writes. The default is zero milliseconds. 1839 1840 - CFG_I2C_EEPROM_ADDR_LEN: 1841 The length in bytes of the EEPROM memory array address. Note 1842 that this is NOT the chip address length! 1843 1844 - CFG_I2C_EEPROM_ADDR_OVERFLOW: 1845 EEPROM chips that implement "address overflow" are ones 1846 like Catalyst 24WC04/08/16 which has 9/10/11 bits of 1847 address and the extra bits end up in the "chip address" bit 1848 slots. This makes a 24WC08 (1Kbyte) chip look like four 256 1849 byte chips. 1850 1851 Note that we consider the length of the address field to 1852 still be one byte because the extra address bits are hidden 1853 in the chip address. 1854 1855 - CFG_EEPROM_SIZE: 1856 The size in bytes of the EEPROM device. 1857 1858 1859- CFG_ENV_IS_IN_DATAFLASH: 1860 1861 Define this if you have a DataFlash memory device which you 1862 want to use for the environment. 1863 1864 - CFG_ENV_OFFSET: 1865 - CFG_ENV_ADDR: 1866 - CFG_ENV_SIZE: 1867 1868 These three #defines specify the offset and size of the 1869 environment area within the total memory of your DataFlash placed 1870 at the specified address. 1871 1872- CFG_ENV_IS_IN_NAND: 1873 1874 Define this if you have a NAND device which you want to use 1875 for the environment. 1876 1877 - CFG_ENV_OFFSET: 1878 - CFG_ENV_SIZE: 1879 1880 These two #defines specify the offset and size of the environment 1881 area within the first NAND device. 1882 1883- CFG_SPI_INIT_OFFSET 1884 1885 Defines offset to the initial SPI buffer area in DPRAM. The 1886 area is used at an early stage (ROM part) if the environment 1887 is configured to reside in the SPI EEPROM: We need a 520 byte 1888 scratch DPRAM area. It is used between the two initialization 1889 calls (spi_init_f() and spi_init_r()). A value of 0xB00 seems 1890 to be a good choice since it makes it far enough from the 1891 start of the data area as well as from the stack pointer. 1892 1893Please note that the environment is read-only as long as the monitor 1894has been relocated to RAM and a RAM copy of the environment has been 1895created; also, when using EEPROM you will have to use getenv_r() 1896until then to read environment variables. 1897 1898The environment is protected by a CRC32 checksum. Before the monitor 1899is relocated into RAM, as a result of a bad CRC you will be working 1900with the compiled-in default environment - *silently*!!! [This is 1901necessary, because the first environment variable we need is the 1902"baudrate" setting for the console - if we have a bad CRC, we don't 1903have any device yet where we could complain.] 1904 1905Note: once the monitor has been relocated, then it will complain if 1906the default environment is used; a new CRC is computed as soon as you 1907use the "saveenv" command to store a valid environment. 1908 1909- CFG_FAULT_ECHO_LINK_DOWN: 1910 Echo the inverted Ethernet link state to the fault LED. 1911 1912 Note: If this option is active, then CFG_FAULT_MII_ADDR 1913 also needs to be defined. 1914 1915- CFG_FAULT_MII_ADDR: 1916 MII address of the PHY to check for the Ethernet link state. 1917 1918- CFG_64BIT_VSPRINTF: 1919 Makes vsprintf (and all *printf functions) support printing 1920 of 64bit values by using the L quantifier 1921 1922- CFG_64BIT_STRTOUL: 1923 Adds simple_strtoull that returns a 64bit value 1924 1925Low Level (hardware related) configuration options: 1926--------------------------------------------------- 1927 1928- CFG_CACHELINE_SIZE: 1929 Cache Line Size of the CPU. 1930 1931- CFG_DEFAULT_IMMR: 1932 Default address of the IMMR after system reset. 1933 1934 Needed on some 8260 systems (MPC8260ADS, PQ2FADS-ZU, 1935 and RPXsuper) to be able to adjust the position of 1936 the IMMR register after a reset. 1937 1938- Floppy Disk Support: 1939 CFG_FDC_DRIVE_NUMBER 1940 1941 the default drive number (default value 0) 1942 1943 CFG_ISA_IO_STRIDE 1944 1945 defines the spacing between fdc chipset registers 1946 (default value 1) 1947 1948 CFG_ISA_IO_OFFSET 1949 1950 defines the offset of register from address. It 1951 depends on which part of the data bus is connected to 1952 the fdc chipset. (default value 0) 1953 1954 If CFG_ISA_IO_STRIDE CFG_ISA_IO_OFFSET and 1955 CFG_FDC_DRIVE_NUMBER are undefined, they take their 1956 default value. 1957 1958 if CFG_FDC_HW_INIT is defined, then the function 1959 fdc_hw_init() is called at the beginning of the FDC 1960 setup. fdc_hw_init() must be provided by the board 1961 source code. It is used to make hardware dependant 1962 initializations. 1963 1964- CFG_IMMR: Physical address of the Internal Memory Mapped 1965 Register; DO NOT CHANGE! (11-4) 1966 [MPC8xx systems only] 1967 1968- CFG_INIT_RAM_ADDR: 1969 1970 Start address of memory area that can be used for 1971 initial data and stack; please note that this must be 1972 writable memory that is working WITHOUT special 1973 initialization, i. e. you CANNOT use normal RAM which 1974 will become available only after programming the 1975 memory controller and running certain initialization 1976 sequences. 1977 1978 U-Boot uses the following memory types: 1979 - MPC8xx and MPC8260: IMMR (internal memory of the CPU) 1980 - MPC824X: data cache 1981 - PPC4xx: data cache 1982 1983- CFG_GBL_DATA_OFFSET: 1984 1985 Offset of the initial data structure in the memory 1986 area defined by CFG_INIT_RAM_ADDR. Usually 1987 CFG_GBL_DATA_OFFSET is chosen such that the initial 1988 data is located at the end of the available space 1989 (sometimes written as (CFG_INIT_RAM_END - 1990 CFG_INIT_DATA_SIZE), and the initial stack is just 1991 below that area (growing from (CFG_INIT_RAM_ADDR + 1992 CFG_GBL_DATA_OFFSET) downward. 1993 1994 Note: 1995 On the MPC824X (or other systems that use the data 1996 cache for initial memory) the address chosen for 1997 CFG_INIT_RAM_ADDR is basically arbitrary - it must 1998 point to an otherwise UNUSED address space between 1999 the top of RAM and the start of the PCI space. 2000 2001- CFG_SIUMCR: SIU Module Configuration (11-6) 2002 2003- CFG_SYPCR: System Protection Control (11-9) 2004 2005- CFG_TBSCR: Time Base Status and Control (11-26) 2006 2007- CFG_PISCR: Periodic Interrupt Status and Control (11-31) 2008 2009- CFG_PLPRCR: PLL, Low-Power, and Reset Control Register (15-30) 2010 2011- CFG_SCCR: System Clock and reset Control Register (15-27) 2012 2013- CFG_OR_TIMING_SDRAM: 2014 SDRAM timing 2015 2016- CFG_MAMR_PTA: 2017 periodic timer for refresh 2018 2019- CFG_DER: Debug Event Register (37-47) 2020 2021- FLASH_BASE0_PRELIM, FLASH_BASE1_PRELIM, CFG_REMAP_OR_AM, 2022 CFG_PRELIM_OR_AM, CFG_OR_TIMING_FLASH, CFG_OR0_REMAP, 2023 CFG_OR0_PRELIM, CFG_BR0_PRELIM, CFG_OR1_REMAP, CFG_OR1_PRELIM, 2024 CFG_BR1_PRELIM: 2025 Memory Controller Definitions: BR0/1 and OR0/1 (FLASH) 2026 2027- SDRAM_BASE2_PRELIM, SDRAM_BASE3_PRELIM, SDRAM_MAX_SIZE, 2028 CFG_OR_TIMING_SDRAM, CFG_OR2_PRELIM, CFG_BR2_PRELIM, 2029 CFG_OR3_PRELIM, CFG_BR3_PRELIM: 2030 Memory Controller Definitions: BR2/3 and OR2/3 (SDRAM) 2031 2032- CFG_MAMR_PTA, CFG_MPTPR_2BK_4K, CFG_MPTPR_1BK_4K, CFG_MPTPR_2BK_8K, 2033 CFG_MPTPR_1BK_8K, CFG_MAMR_8COL, CFG_MAMR_9COL: 2034 Machine Mode Register and Memory Periodic Timer 2035 Prescaler definitions (SDRAM timing) 2036 2037- CFG_I2C_UCODE_PATCH, CFG_I2C_DPMEM_OFFSET [0x1FC0]: 2038 enable I2C microcode relocation patch (MPC8xx); 2039 define relocation offset in DPRAM [DSP2] 2040 2041- CFG_SPI_UCODE_PATCH, CFG_SPI_DPMEM_OFFSET [0x1FC0]: 2042 enable SPI microcode relocation patch (MPC8xx); 2043 define relocation offset in DPRAM [SCC4] 2044 2045- CFG_USE_OSCCLK: 2046 Use OSCM clock mode on MBX8xx board. Be careful, 2047 wrong setting might damage your board. Read 2048 doc/README.MBX before setting this variable! 2049 2050- CFG_CPM_POST_WORD_ADDR: (MPC8xx, MPC8260 only) 2051 Offset of the bootmode word in DPRAM used by post 2052 (Power On Self Tests). This definition overrides 2053 #define'd default value in commproc.h resp. 2054 cpm_8260.h. 2055 2056- CFG_PCI_SLV_MEM_LOCAL, CFG_PCI_SLV_MEM_BUS, CFG_PICMR0_MASK_ATTRIB, 2057 CFG_PCI_MSTR0_LOCAL, CFG_PCIMSK0_MASK, CFG_PCI_MSTR1_LOCAL, 2058 CFG_PCIMSK1_MASK, CFG_PCI_MSTR_MEM_LOCAL, CFG_PCI_MSTR_MEM_BUS, 2059 CFG_CPU_PCI_MEM_START, CFG_PCI_MSTR_MEM_SIZE, CFG_POCMR0_MASK_ATTRIB, 2060 CFG_PCI_MSTR_MEMIO_LOCAL, CFG_PCI_MSTR_MEMIO_BUS, CPU_PCI_MEMIO_START, 2061 CFG_PCI_MSTR_MEMIO_SIZE, CFG_POCMR1_MASK_ATTRIB, CFG_PCI_MSTR_IO_LOCAL, 2062 CFG_PCI_MSTR_IO_BUS, CFG_CPU_PCI_IO_START, CFG_PCI_MSTR_IO_SIZE, 2063 CFG_POCMR2_MASK_ATTRIB: (MPC826x only) 2064 Overrides the default PCI memory map in cpu/mpc8260/pci.c if set. 2065 2066- CONFIG_ETHER_ON_FEC[12] 2067 Define to enable FEC[12] on a 8xx series processor. 2068 2069- CONFIG_FEC[12]_PHY 2070 Define to the hardcoded PHY address which corresponds 2071 to the given FEC; i. e. 2072 #define CONFIG_FEC1_PHY 4 2073 means that the PHY with address 4 is connected to FEC1 2074 2075 When set to -1, means to probe for first available. 2076 2077- CONFIG_FEC[12]_PHY_NORXERR 2078 The PHY does not have a RXERR line (RMII only). 2079 (so program the FEC to ignore it). 2080 2081- CONFIG_RMII 2082 Enable RMII mode for all FECs. 2083 Note that this is a global option, we can't 2084 have one FEC in standard MII mode and another in RMII mode. 2085 2086- CONFIG_CRC32_VERIFY 2087 Add a verify option to the crc32 command. 2088 The syntax is: 2089 2090 => crc32 -v <address> <count> <crc32> 2091 2092 Where address/count indicate a memory area 2093 and crc32 is the correct crc32 which the 2094 area should have. 2095 2096- CONFIG_LOOPW 2097 Add the "loopw" memory command. This only takes effect if 2098 the memory commands are activated globally (CFG_CMD_MEM). 2099 2100Building the Software: 2101====================== 2102 2103Building U-Boot has been tested in native PPC environments (on a 2104PowerBook G3 running LinuxPPC 2000) and in cross environments 2105(running RedHat 6.x and 7.x Linux on x86, Solaris 2.6 on a SPARC, and 2106NetBSD 1.5 on x86). 2107 2108If you are not using a native PPC environment, it is assumed that you 2109have the GNU cross compiling tools available in your path and named 2110with a prefix of "powerpc-linux-". If this is not the case, (e.g. if 2111you are using Monta Vista's Hard Hat Linux CDK 1.2) you must change 2112the definition of CROSS_COMPILE in Makefile. For HHL on a 4xx CPU, 2113change it to: 2114 2115 CROSS_COMPILE = ppc_4xx- 2116 2117 2118U-Boot is intended to be simple to build. After installing the 2119sources you must configure U-Boot for one specific board type. This 2120is done by typing: 2121 2122 make NAME_config 2123 2124where "NAME_config" is the name of one of the existing 2125configurations; the following names are supported: 2126 2127 ADCIOP_config FPS860L_config omap730p2_config 2128 ADS860_config GEN860T_config pcu_e_config 2129 AR405_config GENIETV_config PIP405_config 2130 at91rm9200dk_config GTH_config QS823_config 2131 CANBT_config hermes_config QS850_config 2132 cmi_mpc5xx_config hymod_config QS860T_config 2133 cogent_common_config IP860_config RPXlite_config 2134 cogent_mpc8260_config IVML24_config RPXlite_DW_config 2135 cogent_mpc8xx_config IVMS8_config RPXsuper_config 2136 CPCI405_config JSE_config rsdproto_config 2137 CPCIISER4_config LANTEC_config Sandpoint8240_config 2138 csb272_config lwmon_config sbc8260_config 2139 CU824_config MBX860T_config sbc8560_33_config 2140 DUET_ADS_config MBX_config sbc8560_66_config 2141 EBONY_config MPC8260ADS_config SM850_config 2142 ELPT860_config MPC8540ADS_config SPD823TS_config 2143 ESTEEM192E_config MPC8560ADS_config stxgp3_config 2144 ETX094_config NETVIA_config SXNI855T_config 2145 FADS823_config omap1510inn_config TQM823L_config 2146 FADS850SAR_config omap1610h2_config TQM850L_config 2147 FADS860T_config omap1610inn_config TQM855L_config 2148 FPS850L_config omap5912osk_config TQM860L_config 2149 WALNUT405_config 2150 ZPC1900_config 2151 2152Note: for some board special configuration names may exist; check if 2153 additional information is available from the board vendor; for 2154 instance, the TQM823L systems are available without (standard) 2155 or with LCD support. You can select such additional "features" 2156 when chosing the configuration, i. e. 2157 2158 make TQM823L_config 2159 - will configure for a plain TQM823L, i. e. no LCD support 2160 2161 make TQM823L_LCD_config 2162 - will configure for a TQM823L with U-Boot console on LCD 2163 2164 etc. 2165 2166 2167Finally, type "make all", and you should get some working U-Boot 2168images ready for download to / installation on your system: 2169 2170- "u-boot.bin" is a raw binary image 2171- "u-boot" is an image in ELF binary format 2172- "u-boot.srec" is in Motorola S-Record format 2173 2174 2175Please be aware that the Makefiles assume you are using GNU make, so 2176for instance on NetBSD you might need to use "gmake" instead of 2177native "make". 2178 2179 2180If the system board that you have is not listed, then you will need 2181to port U-Boot to your hardware platform. To do this, follow these 2182steps: 2183 21841. Add a new configuration option for your board to the toplevel 2185 "Makefile" and to the "MAKEALL" script, using the existing 2186 entries as examples. Note that here and at many other places 2187 boards and other names are listed in alphabetical sort order. Please 2188 keep this order. 21892. Create a new directory to hold your board specific code. Add any 2190 files you need. In your board directory, you will need at least 2191 the "Makefile", a "<board>.c", "flash.c" and "u-boot.lds". 21923. Create a new configuration file "include/configs/<board>.h" for 2193 your board 21943. If you're porting U-Boot to a new CPU, then also create a new 2195 directory to hold your CPU specific code. Add any files you need. 21964. Run "make <board>_config" with your new name. 21975. Type "make", and you should get a working "u-boot.srec" file 2198 to be installed on your target system. 21996. Debug and solve any problems that might arise. 2200 [Of course, this last step is much harder than it sounds.] 2201 2202 2203Testing of U-Boot Modifications, Ports to New Hardware, etc.: 2204============================================================== 2205 2206If you have modified U-Boot sources (for instance added a new board 2207or support for new devices, a new CPU, etc.) you are expected to 2208provide feedback to the other developers. The feedback normally takes 2209the form of a "patch", i. e. a context diff against a certain (latest 2210official or latest in CVS) version of U-Boot sources. 2211 2212But before you submit such a patch, please verify that your modifi- 2213cation did not break existing code. At least make sure that *ALL* of 2214the supported boards compile WITHOUT ANY compiler warnings. To do so, 2215just run the "MAKEALL" script, which will configure and build U-Boot 2216for ALL supported system. Be warned, this will take a while. You can 2217select which (cross) compiler to use by passing a `CROSS_COMPILE' 2218environment variable to the script, i. e. to use the cross tools from 2219MontaVista's Hard Hat Linux you can type 2220 2221 CROSS_COMPILE=ppc_8xx- MAKEALL 2222 2223or to build on a native PowerPC system you can type 2224 2225 CROSS_COMPILE=' ' MAKEALL 2226 2227See also "U-Boot Porting Guide" below. 2228 2229 2230Monitor Commands - Overview: 2231============================ 2232 2233go - start application at address 'addr' 2234run - run commands in an environment variable 2235bootm - boot application image from memory 2236bootp - boot image via network using BootP/TFTP protocol 2237tftpboot- boot image via network using TFTP protocol 2238 and env variables "ipaddr" and "serverip" 2239 (and eventually "gatewayip") 2240rarpboot- boot image via network using RARP/TFTP protocol 2241diskboot- boot from IDE devicebootd - boot default, i.e., run 'bootcmd' 2242loads - load S-Record file over serial line 2243loadb - load binary file over serial line (kermit mode) 2244md - memory display 2245mm - memory modify (auto-incrementing) 2246nm - memory modify (constant address) 2247mw - memory write (fill) 2248cp - memory copy 2249cmp - memory compare 2250crc32 - checksum calculation 2251imd - i2c memory display 2252imm - i2c memory modify (auto-incrementing) 2253inm - i2c memory modify (constant address) 2254imw - i2c memory write (fill) 2255icrc32 - i2c checksum calculation 2256iprobe - probe to discover valid I2C chip addresses 2257iloop - infinite loop on address range 2258isdram - print SDRAM configuration information 2259sspi - SPI utility commands 2260base - print or set address offset 2261printenv- print environment variables 2262setenv - set environment variables 2263saveenv - save environment variables to persistent storage 2264protect - enable or disable FLASH write protection 2265erase - erase FLASH memory 2266flinfo - print FLASH memory information 2267bdinfo - print Board Info structure 2268iminfo - print header information for application image 2269coninfo - print console devices and informations 2270ide - IDE sub-system 2271loop - infinite loop on address range 2272loopw - infinite write loop on address range 2273mtest - simple RAM test 2274icache - enable or disable instruction cache 2275dcache - enable or disable data cache 2276reset - Perform RESET of the CPU 2277echo - echo args to console 2278version - print monitor version 2279help - print online help 2280? - alias for 'help' 2281 2282 2283Monitor Commands - Detailed Description: 2284======================================== 2285 2286TODO. 2287 2288For now: just type "help <command>". 2289 2290 2291Environment Variables: 2292====================== 2293 2294U-Boot supports user configuration using Environment Variables which 2295can be made persistent by saving to Flash memory. 2296 2297Environment Variables are set using "setenv", printed using 2298"printenv", and saved to Flash using "saveenv". Using "setenv" 2299without a value can be used to delete a variable from the 2300environment. As long as you don't save the environment you are 2301working with an in-memory copy. In case the Flash area containing the 2302environment is erased by accident, a default environment is provided. 2303 2304Some configuration options can be set using Environment Variables: 2305 2306 baudrate - see CONFIG_BAUDRATE 2307 2308 bootdelay - see CONFIG_BOOTDELAY 2309 2310 bootcmd - see CONFIG_BOOTCOMMAND 2311 2312 bootargs - Boot arguments when booting an RTOS image 2313 2314 bootfile - Name of the image to load with TFTP 2315 2316 autoload - if set to "no" (any string beginning with 'n'), 2317 "bootp" will just load perform a lookup of the 2318 configuration from the BOOTP server, but not try to 2319 load any image using TFTP 2320 2321 autostart - if set to "yes", an image loaded using the "bootp", 2322 "rarpboot", "tftpboot" or "diskboot" commands will 2323 be automatically started (by internally calling 2324 "bootm") 2325 2326 If set to "no", a standalone image passed to the 2327 "bootm" command will be copied to the load address 2328 (and eventually uncompressed), but NOT be started. 2329 This can be used to load and uncompress arbitrary 2330 data. 2331 2332 i2cfast - (PPC405GP|PPC405EP only) 2333 if set to 'y' configures Linux I2C driver for fast 2334 mode (400kHZ). This environment variable is used in 2335 initialization code. So, for changes to be effective 2336 it must be saved and board must be reset. 2337 2338 initrd_high - restrict positioning of initrd images: 2339 If this variable is not set, initrd images will be 2340 copied to the highest possible address in RAM; this 2341 is usually what you want since it allows for 2342 maximum initrd size. If for some reason you want to 2343 make sure that the initrd image is loaded below the 2344 CFG_BOOTMAPSZ limit, you can set this environment 2345 variable to a value of "no" or "off" or "0". 2346 Alternatively, you can set it to a maximum upper 2347 address to use (U-Boot will still check that it 2348 does not overwrite the U-Boot stack and data). 2349 2350 For instance, when you have a system with 16 MB 2351 RAM, and want to reserve 4 MB from use by Linux, 2352 you can do this by adding "mem=12M" to the value of 2353 the "bootargs" variable. However, now you must make 2354 sure that the initrd image is placed in the first 2355 12 MB as well - this can be done with 2356 2357 setenv initrd_high 00c00000 2358 2359 If you set initrd_high to 0xFFFFFFFF, this is an 2360 indication to U-Boot that all addresses are legal 2361 for the Linux kernel, including addresses in flash 2362 memory. In this case U-Boot will NOT COPY the 2363 ramdisk at all. This may be useful to reduce the 2364 boot time on your system, but requires that this 2365 feature is supported by your Linux kernel. 2366 2367 ipaddr - IP address; needed for tftpboot command 2368 2369 loadaddr - Default load address for commands like "bootp", 2370 "rarpboot", "tftpboot", "loadb" or "diskboot" 2371 2372 loads_echo - see CONFIG_LOADS_ECHO 2373 2374 serverip - TFTP server IP address; needed for tftpboot command 2375 2376 bootretry - see CONFIG_BOOT_RETRY_TIME 2377 2378 bootdelaykey - see CONFIG_AUTOBOOT_DELAY_STR 2379 2380 bootstopkey - see CONFIG_AUTOBOOT_STOP_STR 2381 2382 ethprime - When CONFIG_NET_MULTI is enabled controls which 2383 interface is used first. 2384 2385 ethact - When CONFIG_NET_MULTI is enabled controls which 2386 interface is currently active. For example you 2387 can do the following 2388 2389 => setenv ethact FEC ETHERNET 2390 => ping 192.168.0.1 # traffic sent on FEC ETHERNET 2391 => setenv ethact SCC ETHERNET 2392 => ping 10.0.0.1 # traffic sent on SCC ETHERNET 2393 2394 netretry - When set to "no" each network operation will 2395 either succeed or fail without retrying. 2396 When set to "once" the network operation will 2397 fail when all the available network interfaces 2398 are tried once without success. 2399 Useful on scripts which control the retry operation 2400 themselves. 2401 2402 vlan - When set to a value < 4095 the traffic over 2403 ethernet is encapsulated/received over 802.1q 2404 VLAN tagged frames. 2405 2406The following environment variables may be used and automatically 2407updated by the network boot commands ("bootp" and "rarpboot"), 2408depending the information provided by your boot server: 2409 2410 bootfile - see above 2411 dnsip - IP address of your Domain Name Server 2412 dnsip2 - IP address of your secondary Domain Name Server 2413 gatewayip - IP address of the Gateway (Router) to use 2414 hostname - Target hostname 2415 ipaddr - see above 2416 netmask - Subnet Mask 2417 rootpath - Pathname of the root filesystem on the NFS server 2418 serverip - see above 2419 2420 2421There are two special Environment Variables: 2422 2423 serial# - contains hardware identification information such 2424 as type string and/or serial number 2425 ethaddr - Ethernet address 2426 2427These variables can be set only once (usually during manufacturing of 2428the board). U-Boot refuses to delete or overwrite these variables 2429once they have been set once. 2430 2431 2432Further special Environment Variables: 2433 2434 ver - Contains the U-Boot version string as printed 2435 with the "version" command. This variable is 2436 readonly (see CONFIG_VERSION_VARIABLE). 2437 2438 2439Please note that changes to some configuration parameters may take 2440only effect after the next boot (yes, that's just like Windoze :-). 2441 2442 2443Command Line Parsing: 2444===================== 2445 2446There are two different command line parsers available with U-Boot: 2447the old "simple" one, and the much more powerful "hush" shell: 2448 2449Old, simple command line parser: 2450-------------------------------- 2451 2452- supports environment variables (through setenv / saveenv commands) 2453- several commands on one line, separated by ';' 2454- variable substitution using "... $(name) ..." syntax 2455- special characters ('$', ';') can be escaped by prefixing with '\', 2456 for example: 2457 setenv bootcmd bootm \$(address) 2458- You can also escape text by enclosing in single apostrophes, for example: 2459 setenv addip 'setenv bootargs $bootargs ip=$ipaddr:$serverip:$gatewayip:$netmask:$hostname::off' 2460 2461Hush shell: 2462----------- 2463 2464- similar to Bourne shell, with control structures like 2465 if...then...else...fi, for...do...done; while...do...done, 2466 until...do...done, ... 2467- supports environment ("global") variables (through setenv / saveenv 2468 commands) and local shell variables (through standard shell syntax 2469 "name=value"); only environment variables can be used with "run" 2470 command 2471 2472General rules: 2473-------------- 2474 2475(1) If a command line (or an environment variable executed by a "run" 2476 command) contains several commands separated by semicolon, and 2477 one of these commands fails, then the remaining commands will be 2478 executed anyway. 2479 2480(2) If you execute several variables with one call to run (i. e. 2481 calling run with a list af variables as arguments), any failing 2482 command will cause "run" to terminate, i. e. the remaining 2483 variables are not executed. 2484 2485Note for Redundant Ethernet Interfaces: 2486======================================= 2487 2488Some boards come with redundant ethernet interfaces; U-Boot supports 2489such configurations and is capable of automatic selection of a 2490"working" interface when needed. MAC assignment works as follows: 2491 2492Network interfaces are numbered eth0, eth1, eth2, ... Corresponding 2493MAC addresses can be stored in the environment as "ethaddr" (=>eth0), 2494"eth1addr" (=>eth1), "eth2addr", ... 2495 2496If the network interface stores some valid MAC address (for instance 2497in SROM), this is used as default address if there is NO correspon- 2498ding setting in the environment; if the corresponding environment 2499variable is set, this overrides the settings in the card; that means: 2500 2501o If the SROM has a valid MAC address, and there is no address in the 2502 environment, the SROM's address is used. 2503 2504o If there is no valid address in the SROM, and a definition in the 2505 environment exists, then the value from the environment variable is 2506 used. 2507 2508o If both the SROM and the environment contain a MAC address, and 2509 both addresses are the same, this MAC address is used. 2510 2511o If both the SROM and the environment contain a MAC address, and the 2512 addresses differ, the value from the environment is used and a 2513 warning is printed. 2514 2515o If neither SROM nor the environment contain a MAC address, an error 2516 is raised. 2517 2518 2519Image Formats: 2520============== 2521 2522The "boot" commands of this monitor operate on "image" files which 2523can be basicly anything, preceeded by a special header; see the 2524definitions in include/image.h for details; basicly, the header 2525defines the following image properties: 2526 2527* Target Operating System (Provisions for OpenBSD, NetBSD, FreeBSD, 2528 4.4BSD, Linux, SVR4, Esix, Solaris, Irix, SCO, Dell, NCR, VxWorks, 2529 LynxOS, pSOS, QNX, RTEMS, ARTOS; 2530 Currently supported: Linux, NetBSD, VxWorks, QNX, RTEMS, ARTOS, LynxOS). 2531* Target CPU Architecture (Provisions for Alpha, ARM, Intel x86, 2532 IA64, MIPS, NIOS, PowerPC, IBM S390, SuperH, Sparc, Sparc 64 Bit; 2533 Currently supported: ARM, Intel x86, MIPS, NIOS, PowerPC). 2534* Compression Type (uncompressed, gzip, bzip2) 2535* Load Address 2536* Entry Point 2537* Image Name 2538* Image Timestamp 2539 2540The header is marked by a special Magic Number, and both the header 2541and the data portions of the image are secured against corruption by 2542CRC32 checksums. 2543 2544 2545Linux Support: 2546============== 2547 2548Although U-Boot should support any OS or standalone application 2549easily, the main focus has always been on Linux during the design of 2550U-Boot. 2551 2552U-Boot includes many features that so far have been part of some 2553special "boot loader" code within the Linux kernel. Also, any 2554"initrd" images to be used are no longer part of one big Linux image; 2555instead, kernel and "initrd" are separate images. This implementation 2556serves several purposes: 2557 2558- the same features can be used for other OS or standalone 2559 applications (for instance: using compressed images to reduce the 2560 Flash memory footprint) 2561 2562- it becomes much easier to port new Linux kernel versions because 2563 lots of low-level, hardware dependent stuff are done by U-Boot 2564 2565- the same Linux kernel image can now be used with different "initrd" 2566 images; of course this also means that different kernel images can 2567 be run with the same "initrd". This makes testing easier (you don't 2568 have to build a new "zImage.initrd" Linux image when you just 2569 change a file in your "initrd"). Also, a field-upgrade of the 2570 software is easier now. 2571 2572 2573Linux HOWTO: 2574============ 2575 2576Porting Linux to U-Boot based systems: 2577--------------------------------------- 2578 2579U-Boot cannot save you from doing all the necessary modifications to 2580configure the Linux device drivers for use with your target hardware 2581(no, we don't intend to provide a full virtual machine interface to 2582Linux :-). 2583 2584But now you can ignore ALL boot loader code (in arch/ppc/mbxboot). 2585 2586Just make sure your machine specific header file (for instance 2587include/asm-ppc/tqm8xx.h) includes the same definition of the Board 2588Information structure as we define in include/u-boot.h, and make 2589sure that your definition of IMAP_ADDR uses the same value as your 2590U-Boot configuration in CFG_IMMR. 2591 2592 2593Configuring the Linux kernel: 2594----------------------------- 2595 2596No specific requirements for U-Boot. Make sure you have some root 2597device (initial ramdisk, NFS) for your target system. 2598 2599 2600Building a Linux Image: 2601----------------------- 2602 2603With U-Boot, "normal" build targets like "zImage" or "bzImage" are 2604not used. If you use recent kernel source, a new build target 2605"uImage" will exist which automatically builds an image usable by 2606U-Boot. Most older kernels also have support for a "pImage" target, 2607which was introduced for our predecessor project PPCBoot and uses a 2608100% compatible format. 2609 2610Example: 2611 2612 make TQM850L_config 2613 make oldconfig 2614 make dep 2615 make uImage 2616 2617The "uImage" build target uses a special tool (in 'tools/mkimage') to 2618encapsulate a compressed Linux kernel image with header information, 2619CRC32 checksum etc. for use with U-Boot. This is what we are doing: 2620 2621* build a standard "vmlinux" kernel image (in ELF binary format): 2622 2623* convert the kernel into a raw binary image: 2624 2625 ${CROSS_COMPILE}-objcopy -O binary \ 2626 -R .note -R .comment \ 2627 -S vmlinux linux.bin 2628 2629* compress the binary image: 2630 2631 gzip -9 linux.bin 2632 2633* package compressed binary image for U-Boot: 2634 2635 mkimage -A ppc -O linux -T kernel -C gzip \ 2636 -a 0 -e 0 -n "Linux Kernel Image" \ 2637 -d linux.bin.gz uImage 2638 2639 2640The "mkimage" tool can also be used to create ramdisk images for use 2641with U-Boot, either separated from the Linux kernel image, or 2642combined into one file. "mkimage" encapsulates the images with a 64 2643byte header containing information about target architecture, 2644operating system, image type, compression method, entry points, time 2645stamp, CRC32 checksums, etc. 2646 2647"mkimage" can be called in two ways: to verify existing images and 2648print the header information, or to build new images. 2649 2650In the first form (with "-l" option) mkimage lists the information 2651contained in the header of an existing U-Boot image; this includes 2652checksum verification: 2653 2654 tools/mkimage -l image 2655 -l ==> list image header information 2656 2657The second form (with "-d" option) is used to build a U-Boot image 2658from a "data file" which is used as image payload: 2659 2660 tools/mkimage -A arch -O os -T type -C comp -a addr -e ep \ 2661 -n name -d data_file image 2662 -A ==> set architecture to 'arch' 2663 -O ==> set operating system to 'os' 2664 -T ==> set image type to 'type' 2665 -C ==> set compression type 'comp' 2666 -a ==> set load address to 'addr' (hex) 2667 -e ==> set entry point to 'ep' (hex) 2668 -n ==> set image name to 'name' 2669 -d ==> use image data from 'datafile' 2670 2671Right now, all Linux kernels for PowerPC systems use the same load 2672address (0x00000000), but the entry point address depends on the 2673kernel version: 2674 2675- 2.2.x kernels have the entry point at 0x0000000C, 2676- 2.3.x and later kernels have the entry point at 0x00000000. 2677 2678So a typical call to build a U-Boot image would read: 2679 2680 -> tools/mkimage -n '2.4.4 kernel for TQM850L' \ 2681 > -A ppc -O linux -T kernel -C gzip -a 0 -e 0 \ 2682 > -d /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/ppc/coffboot/vmlinux.gz \ 2683 > examples/uImage.TQM850L 2684 Image Name: 2.4.4 kernel for TQM850L 2685 Created: Wed Jul 19 02:34:59 2000 2686 Image Type: PowerPC Linux Kernel Image (gzip compressed) 2687 Data Size: 335725 Bytes = 327.86 kB = 0.32 MB 2688 Load Address: 0x00000000 2689 Entry Point: 0x00000000 2690 2691To verify the contents of the image (or check for corruption): 2692 2693 -> tools/mkimage -l examples/uImage.TQM850L 2694 Image Name: 2.4.4 kernel for TQM850L 2695 Created: Wed Jul 19 02:34:59 2000 2696 Image Type: PowerPC Linux Kernel Image (gzip compressed) 2697 Data Size: 335725 Bytes = 327.86 kB = 0.32 MB 2698 Load Address: 0x00000000 2699 Entry Point: 0x00000000 2700 2701NOTE: for embedded systems where boot time is critical you can trade 2702speed for memory and install an UNCOMPRESSED image instead: this 2703needs more space in Flash, but boots much faster since it does not 2704need to be uncompressed: 2705 2706 -> gunzip /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/ppc/coffboot/vmlinux.gz 2707 -> tools/mkimage -n '2.4.4 kernel for TQM850L' \ 2708 > -A ppc -O linux -T kernel -C none -a 0 -e 0 \ 2709 > -d /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/ppc/coffboot/vmlinux \ 2710 > examples/uImage.TQM850L-uncompressed 2711 Image Name: 2.4.4 kernel for TQM850L 2712 Created: Wed Jul 19 02:34:59 2000 2713 Image Type: PowerPC Linux Kernel Image (uncompressed) 2714 Data Size: 792160 Bytes = 773.59 kB = 0.76 MB 2715 Load Address: 0x00000000 2716 Entry Point: 0x00000000 2717 2718 2719Similar you can build U-Boot images from a 'ramdisk.image.gz' file 2720when your kernel is intended to use an initial ramdisk: 2721 2722 -> tools/mkimage -n 'Simple Ramdisk Image' \ 2723 > -A ppc -O linux -T ramdisk -C gzip \ 2724 > -d /LinuxPPC/images/SIMPLE-ramdisk.image.gz examples/simple-initrd 2725 Image Name: Simple Ramdisk Image 2726 Created: Wed Jan 12 14:01:50 2000 2727 Image Type: PowerPC Linux RAMDisk Image (gzip compressed) 2728 Data Size: 566530 Bytes = 553.25 kB = 0.54 MB 2729 Load Address: 0x00000000 2730 Entry Point: 0x00000000 2731 2732 2733Installing a Linux Image: 2734------------------------- 2735 2736To downloading a U-Boot image over the serial (console) interface, 2737you must convert the image to S-Record format: 2738 2739 objcopy -I binary -O srec examples/image examples/image.srec 2740 2741The 'objcopy' does not understand the information in the U-Boot 2742image header, so the resulting S-Record file will be relative to 2743address 0x00000000. To load it to a given address, you need to 2744specify the target address as 'offset' parameter with the 'loads' 2745command. 2746 2747Example: install the image to address 0x40100000 (which on the 2748TQM8xxL is in the first Flash bank): 2749 2750 => erase 40100000 401FFFFF 2751 2752 .......... done 2753 Erased 8 sectors 2754 2755 => loads 40100000 2756 ## Ready for S-Record download ... 2757 ~>examples/image.srec 2758 1 2 3 4 5 6 7 8 9 10 11 12 13 ... 2759 ... 2760 15989 15990 15991 15992 2761 [file transfer complete] 2762 [connected] 2763 ## Start Addr = 0x00000000 2764 2765 2766You can check the success of the download using the 'iminfo' command; 2767this includes a checksum verification so you can be sure no data 2768corruption happened: 2769 2770 => imi 40100000 2771 2772 ## Checking Image at 40100000 ... 2773 Image Name: 2.2.13 for initrd on TQM850L 2774 Image Type: PowerPC Linux Kernel Image (gzip compressed) 2775 Data Size: 335725 Bytes = 327 kB = 0 MB 2776 Load Address: 00000000 2777 Entry Point: 0000000c 2778 Verifying Checksum ... OK 2779 2780 2781Boot Linux: 2782----------- 2783 2784The "bootm" command is used to boot an application that is stored in 2785memory (RAM or Flash). In case of a Linux kernel image, the contents 2786of the "bootargs" environment variable is passed to the kernel as 2787parameters. You can check and modify this variable using the 2788"printenv" and "setenv" commands: 2789 2790 2791 => printenv bootargs 2792 bootargs=root=/dev/ram 2793 2794 => setenv bootargs root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2 2795 2796 => printenv bootargs 2797 bootargs=root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2 2798 2799 => bootm 40020000 2800 ## Booting Linux kernel at 40020000 ... 2801 Image Name: 2.2.13 for NFS on TQM850L 2802 Image Type: PowerPC Linux Kernel Image (gzip compressed) 2803 Data Size: 381681 Bytes = 372 kB = 0 MB 2804 Load Address: 00000000 2805 Entry Point: 0000000c 2806 Verifying Checksum ... OK 2807 Uncompressing Kernel Image ... OK 2808 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 2809 Boot arguments: root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2 2810 time_init: decrementer frequency = 187500000/60 2811 Calibrating delay loop... 49.77 BogoMIPS 2812 Memory: 15208k available (700k kernel code, 444k data, 32k init) [c0000000,c1000000] 2813 ... 2814 2815If you want to boot a Linux kernel with initial ram disk, you pass 2816the memory addresses of both the kernel and the initrd image (PPBCOOT 2817format!) to the "bootm" command: 2818 2819 => imi 40100000 40200000 2820 2821 ## Checking Image at 40100000 ... 2822 Image Name: 2.2.13 for initrd on TQM850L 2823 Image Type: PowerPC Linux Kernel Image (gzip compressed) 2824 Data Size: 335725 Bytes = 327 kB = 0 MB 2825 Load Address: 00000000 2826 Entry Point: 0000000c 2827 Verifying Checksum ... OK 2828 2829 ## Checking Image at 40200000 ... 2830 Image Name: Simple Ramdisk Image 2831 Image Type: PowerPC Linux RAMDisk Image (gzip compressed) 2832 Data Size: 566530 Bytes = 553 kB = 0 MB 2833 Load Address: 00000000 2834 Entry Point: 00000000 2835 Verifying Checksum ... OK 2836 2837 => bootm 40100000 40200000 2838 ## Booting Linux kernel at 40100000 ... 2839 Image Name: 2.2.13 for initrd on TQM850L 2840 Image Type: PowerPC Linux Kernel Image (gzip compressed) 2841 Data Size: 335725 Bytes = 327 kB = 0 MB 2842 Load Address: 00000000 2843 Entry Point: 0000000c 2844 Verifying Checksum ... OK 2845 Uncompressing Kernel Image ... OK 2846 ## Loading RAMDisk Image at 40200000 ... 2847 Image Name: Simple Ramdisk Image 2848 Image Type: PowerPC Linux RAMDisk Image (gzip compressed) 2849 Data Size: 566530 Bytes = 553 kB = 0 MB 2850 Load Address: 00000000 2851 Entry Point: 00000000 2852 Verifying Checksum ... OK 2853 Loading Ramdisk ... OK 2854 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 2855 Boot arguments: root=/dev/ram 2856 time_init: decrementer frequency = 187500000/60 2857 Calibrating delay loop... 49.77 BogoMIPS 2858 ... 2859 RAMDISK: Compressed image found at block 0 2860 VFS: Mounted root (ext2 filesystem). 2861 2862 bash# 2863 2864More About U-Boot Image Types: 2865------------------------------ 2866 2867U-Boot supports the following image types: 2868 2869 "Standalone Programs" are directly runnable in the environment 2870 provided by U-Boot; it is expected that (if they behave 2871 well) you can continue to work in U-Boot after return from 2872 the Standalone Program. 2873 "OS Kernel Images" are usually images of some Embedded OS which 2874 will take over control completely. Usually these programs 2875 will install their own set of exception handlers, device 2876 drivers, set up the MMU, etc. - this means, that you cannot 2877 expect to re-enter U-Boot except by resetting the CPU. 2878 "RAMDisk Images" are more or less just data blocks, and their 2879 parameters (address, size) are passed to an OS kernel that is 2880 being started. 2881 "Multi-File Images" contain several images, typically an OS 2882 (Linux) kernel image and one or more data images like 2883 RAMDisks. This construct is useful for instance when you want 2884 to boot over the network using BOOTP etc., where the boot 2885 server provides just a single image file, but you want to get 2886 for instance an OS kernel and a RAMDisk image. 2887 2888 "Multi-File Images" start with a list of image sizes, each 2889 image size (in bytes) specified by an "uint32_t" in network 2890 byte order. This list is terminated by an "(uint32_t)0". 2891 Immediately after the terminating 0 follow the images, one by 2892 one, all aligned on "uint32_t" boundaries (size rounded up to 2893 a multiple of 4 bytes). 2894 2895 "Firmware Images" are binary images containing firmware (like 2896 U-Boot or FPGA images) which usually will be programmed to 2897 flash memory. 2898 2899 "Script files" are command sequences that will be executed by 2900 U-Boot's command interpreter; this feature is especially 2901 useful when you configure U-Boot to use a real shell (hush) 2902 as command interpreter. 2903 2904 2905Standalone HOWTO: 2906================= 2907 2908One of the features of U-Boot is that you can dynamically load and 2909run "standalone" applications, which can use some resources of 2910U-Boot like console I/O functions or interrupt services. 2911 2912Two simple examples are included with the sources: 2913 2914"Hello World" Demo: 2915------------------- 2916 2917'examples/hello_world.c' contains a small "Hello World" Demo 2918application; it is automatically compiled when you build U-Boot. 2919It's configured to run at address 0x00040004, so you can play with it 2920like that: 2921 2922 => loads 2923 ## Ready for S-Record download ... 2924 ~>examples/hello_world.srec 2925 1 2 3 4 5 6 7 8 9 10 11 ... 2926 [file transfer complete] 2927 [connected] 2928 ## Start Addr = 0x00040004 2929 2930 => go 40004 Hello World! This is a test. 2931 ## Starting application at 0x00040004 ... 2932 Hello World 2933 argc = 7 2934 argv[0] = "40004" 2935 argv[1] = "Hello" 2936 argv[2] = "World!" 2937 argv[3] = "This" 2938 argv[4] = "is" 2939 argv[5] = "a" 2940 argv[6] = "test." 2941 argv[7] = "<NULL>" 2942 Hit any key to exit ... 2943 2944 ## Application terminated, rc = 0x0 2945 2946Another example, which demonstrates how to register a CPM interrupt 2947handler with the U-Boot code, can be found in 'examples/timer.c'. 2948Here, a CPM timer is set up to generate an interrupt every second. 2949The interrupt service routine is trivial, just printing a '.' 2950character, but this is just a demo program. The application can be 2951controlled by the following keys: 2952 2953 ? - print current values og the CPM Timer registers 2954 b - enable interrupts and start timer 2955 e - stop timer and disable interrupts 2956 q - quit application 2957 2958 => loads 2959 ## Ready for S-Record download ... 2960 ~>examples/timer.srec 2961 1 2 3 4 5 6 7 8 9 10 11 ... 2962 [file transfer complete] 2963 [connected] 2964 ## Start Addr = 0x00040004 2965 2966 => go 40004 2967 ## Starting application at 0x00040004 ... 2968 TIMERS=0xfff00980 2969 Using timer 1 2970 tgcr @ 0xfff00980, tmr @ 0xfff00990, trr @ 0xfff00994, tcr @ 0xfff00998, tcn @ 0xfff0099c, ter @ 0xfff009b0 2971 2972Hit 'b': 2973 [q, b, e, ?] Set interval 1000000 us 2974 Enabling timer 2975Hit '?': 2976 [q, b, e, ?] ........ 2977 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0xef6, ter=0x0 2978Hit '?': 2979 [q, b, e, ?] . 2980 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x2ad4, ter=0x0 2981Hit '?': 2982 [q, b, e, ?] . 2983 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x1efc, ter=0x0 2984Hit '?': 2985 [q, b, e, ?] . 2986 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x169d, ter=0x0 2987Hit 'e': 2988 [q, b, e, ?] ...Stopping timer 2989Hit 'q': 2990 [q, b, e, ?] ## Application terminated, rc = 0x0 2991 2992 2993Minicom warning: 2994================ 2995 2996Over time, many people have reported problems when trying to use the 2997"minicom" terminal emulation program for serial download. I (wd) 2998consider minicom to be broken, and recommend not to use it. Under 2999Unix, I recommend to use C-Kermit for general purpose use (and 3000especially for kermit binary protocol download ("loadb" command), and 3001use "cu" for S-Record download ("loads" command). 3002 3003Nevertheless, if you absolutely want to use it try adding this 3004configuration to your "File transfer protocols" section: 3005 3006 Name Program Name U/D FullScr IO-Red. Multi 3007 X kermit /usr/bin/kermit -i -l %l -s Y U Y N N 3008 Y kermit /usr/bin/kermit -i -l %l -r N D Y N N 3009 3010 3011NetBSD Notes: 3012============= 3013 3014Starting at version 0.9.2, U-Boot supports NetBSD both as host 3015(build U-Boot) and target system (boots NetBSD/mpc8xx). 3016 3017Building requires a cross environment; it is known to work on 3018NetBSD/i386 with the cross-powerpc-netbsd-1.3 package (you will also 3019need gmake since the Makefiles are not compatible with BSD make). 3020Note that the cross-powerpc package does not install include files; 3021attempting to build U-Boot will fail because <machine/ansi.h> is 3022missing. This file has to be installed and patched manually: 3023 3024 # cd /usr/pkg/cross/powerpc-netbsd/include 3025 # mkdir powerpc 3026 # ln -s powerpc machine 3027 # cp /usr/src/sys/arch/powerpc/include/ansi.h powerpc/ansi.h 3028 # ${EDIT} powerpc/ansi.h ## must remove __va_list, _BSD_VA_LIST 3029 3030Native builds *don't* work due to incompatibilities between native 3031and U-Boot include files. 3032 3033Booting assumes that (the first part of) the image booted is a 3034stage-2 loader which in turn loads and then invokes the kernel 3035proper. Loader sources will eventually appear in the NetBSD source 3036tree (probably in sys/arc/mpc8xx/stand/u-boot_stage2/); in the 3037meantime, send mail to bruno@exet-ag.de and/or wd@denx.de for 3038details. 3039 3040 3041Implementation Internals: 3042========================= 3043 3044The following is not intended to be a complete description of every 3045implementation detail. However, it should help to understand the 3046inner workings of U-Boot and make it easier to port it to custom 3047hardware. 3048 3049 3050Initial Stack, Global Data: 3051--------------------------- 3052 3053The implementation of U-Boot is complicated by the fact that U-Boot 3054starts running out of ROM (flash memory), usually without access to 3055system RAM (because the memory controller is not initialized yet). 3056This means that we don't have writable Data or BSS segments, and BSS 3057is not initialized as zero. To be able to get a C environment working 3058at all, we have to allocate at least a minimal stack. Implementation 3059options for this are defined and restricted by the CPU used: Some CPU 3060models provide on-chip memory (like the IMMR area on MPC8xx and 3061MPC826x processors), on others (parts of) the data cache can be 3062locked as (mis-) used as memory, etc. 3063 3064 Chris Hallinan posted a good summary of these issues to the 3065 u-boot-users mailing list: 3066 3067 Subject: RE: [U-Boot-Users] RE: More On Memory Bank x (nothingness)? 3068 From: "Chris Hallinan" <clh@net1plus.com> 3069 Date: Mon, 10 Feb 2003 16:43:46 -0500 (22:43 MET) 3070 ... 3071 3072 Correct me if I'm wrong, folks, but the way I understand it 3073 is this: Using DCACHE as initial RAM for Stack, etc, does not 3074 require any physical RAM backing up the cache. The cleverness 3075 is that the cache is being used as a temporary supply of 3076 necessary storage before the SDRAM controller is setup. It's 3077 beyond the scope of this list to expain the details, but you 3078 can see how this works by studying the cache architecture and 3079 operation in the architecture and processor-specific manuals. 3080 3081 OCM is On Chip Memory, which I believe the 405GP has 4K. It 3082 is another option for the system designer to use as an 3083 initial stack/ram area prior to SDRAM being available. Either 3084 option should work for you. Using CS 4 should be fine if your 3085 board designers haven't used it for something that would 3086 cause you grief during the initial boot! It is frequently not 3087 used. 3088 3089 CFG_INIT_RAM_ADDR should be somewhere that won't interfere 3090 with your processor/board/system design. The default value 3091 you will find in any recent u-boot distribution in 3092 Walnut405.h should work for you. I'd set it to a value larger 3093 than your SDRAM module. If you have a 64MB SDRAM module, set 3094 it above 400_0000. Just make sure your board has no resources 3095 that are supposed to respond to that address! That code in 3096 start.S has been around a while and should work as is when 3097 you get the config right. 3098 3099 -Chris Hallinan 3100 DS4.COM, Inc. 3101 3102It is essential to remember this, since it has some impact on the C 3103code for the initialization procedures: 3104 3105* Initialized global data (data segment) is read-only. Do not attempt 3106 to write it. 3107 3108* Do not use any unitialized global data (or implicitely initialized 3109 as zero data - BSS segment) at all - this is undefined, initiali- 3110 zation is performed later (when relocating to RAM). 3111 3112* Stack space is very limited. Avoid big data buffers or things like 3113 that. 3114 3115Having only the stack as writable memory limits means we cannot use 3116normal global data to share information beween the code. But it 3117turned out that the implementation of U-Boot can be greatly 3118simplified by making a global data structure (gd_t) available to all 3119functions. We could pass a pointer to this data as argument to _all_ 3120functions, but this would bloat the code. Instead we use a feature of 3121the GCC compiler (Global Register Variables) to share the data: we 3122place a pointer (gd) to the global data into a register which we 3123reserve for this purpose. 3124 3125When choosing a register for such a purpose we are restricted by the 3126relevant (E)ABI specifications for the current architecture, and by 3127GCC's implementation. 3128 3129For PowerPC, the following registers have specific use: 3130 R1: stack pointer 3131 R2: TOC pointer 3132 R3-R4: parameter passing and return values 3133 R5-R10: parameter passing 3134 R13: small data area pointer 3135 R30: GOT pointer 3136 R31: frame pointer 3137 3138 (U-Boot also uses R14 as internal GOT pointer.) 3139 3140 ==> U-Boot will use R29 to hold a pointer to the global data 3141 3142 Note: on PPC, we could use a static initializer (since the 3143 address of the global data structure is known at compile time), 3144 but it turned out that reserving a register results in somewhat 3145 smaller code - although the code savings are not that big (on 3146 average for all boards 752 bytes for the whole U-Boot image, 3147 624 text + 127 data). 3148 3149On ARM, the following registers are used: 3150 3151 R0: function argument word/integer result 3152 R1-R3: function argument word 3153 R9: GOT pointer 3154 R10: stack limit (used only if stack checking if enabled) 3155 R11: argument (frame) pointer 3156 R12: temporary workspace 3157 R13: stack pointer 3158 R14: link register 3159 R15: program counter 3160 3161 ==> U-Boot will use R8 to hold a pointer to the global data 3162 3163 3164Memory Management: 3165------------------ 3166 3167U-Boot runs in system state and uses physical addresses, i.e. the 3168MMU is not used either for address mapping nor for memory protection. 3169 3170The available memory is mapped to fixed addresses using the memory 3171controller. In this process, a contiguous block is formed for each 3172memory type (Flash, SDRAM, SRAM), even when it consists of several 3173physical memory banks. 3174 3175U-Boot is installed in the first 128 kB of the first Flash bank (on 3176TQM8xxL modules this is the range 0x40000000 ... 0x4001FFFF). After 3177booting and sizing and initializing DRAM, the code relocates itself 3178to the upper end of DRAM. Immediately below the U-Boot code some 3179memory is reserved for use by malloc() [see CFG_MALLOC_LEN 3180configuration setting]. Below that, a structure with global Board 3181Info data is placed, followed by the stack (growing downward). 3182 3183Additionally, some exception handler code is copied to the low 8 kB 3184of DRAM (0x00000000 ... 0x00001FFF). 3185 3186So a typical memory configuration with 16 MB of DRAM could look like 3187this: 3188 3189 0x0000 0000 Exception Vector code 3190 : 3191 0x0000 1FFF 3192 0x0000 2000 Free for Application Use 3193 : 3194 : 3195 3196 : 3197 : 3198 0x00FB FF20 Monitor Stack (Growing downward) 3199 0x00FB FFAC Board Info Data and permanent copy of global data 3200 0x00FC 0000 Malloc Arena 3201 : 3202 0x00FD FFFF 3203 0x00FE 0000 RAM Copy of Monitor Code 3204 ... eventually: LCD or video framebuffer 3205 ... eventually: pRAM (Protected RAM - unchanged by reset) 3206 0x00FF FFFF [End of RAM] 3207 3208 3209System Initialization: 3210---------------------- 3211 3212In the reset configuration, U-Boot starts at the reset entry point 3213(on most PowerPC systens at address 0x00000100). Because of the reset 3214configuration for CS0# this is a mirror of the onboard Flash memory. 3215To be able to re-map memory U-Boot then jumps to its link address. 3216To be able to implement the initialization code in C, a (small!) 3217initial stack is set up in the internal Dual Ported RAM (in case CPUs 3218which provide such a feature like MPC8xx or MPC8260), or in a locked 3219part of the data cache. After that, U-Boot initializes the CPU core, 3220the caches and the SIU. 3221 3222Next, all (potentially) available memory banks are mapped using a 3223preliminary mapping. For example, we put them on 512 MB boundaries 3224(multiples of 0x20000000: SDRAM on 0x00000000 and 0x20000000, Flash 3225on 0x40000000 and 0x60000000, SRAM on 0x80000000). Then UPM A is 3226programmed for SDRAM access. Using the temporary configuration, a 3227simple memory test is run that determines the size of the SDRAM 3228banks. 3229 3230When there is more than one SDRAM bank, and the banks are of 3231different size, the largest is mapped first. For equal size, the first 3232bank (CS2#) is mapped first. The first mapping is always for address 32330x00000000, with any additional banks following immediately to create 3234contiguous memory starting from 0. 3235 3236Then, the monitor installs itself at the upper end of the SDRAM area 3237and allocates memory for use by malloc() and for the global Board 3238Info data; also, the exception vector code is copied to the low RAM 3239pages, and the final stack is set up. 3240 3241Only after this relocation will you have a "normal" C environment; 3242until that you are restricted in several ways, mostly because you are 3243running from ROM, and because the code will have to be relocated to a 3244new address in RAM. 3245 3246 3247U-Boot Porting Guide: 3248---------------------- 3249 3250[Based on messages by Jerry Van Baren in the U-Boot-Users mailing 3251list, October 2002] 3252 3253 3254int main (int argc, char *argv[]) 3255{ 3256 sighandler_t no_more_time; 3257 3258 signal (SIGALRM, no_more_time); 3259 alarm (PROJECT_DEADLINE - toSec (3 * WEEK)); 3260 3261 if (available_money > available_manpower) { 3262 pay consultant to port U-Boot; 3263 return 0; 3264 } 3265 3266 Download latest U-Boot source; 3267 3268 Subscribe to u-boot-users mailing list; 3269 3270 if (clueless) { 3271 email ("Hi, I am new to U-Boot, how do I get started?"); 3272 } 3273 3274 while (learning) { 3275 Read the README file in the top level directory; 3276 Read http://www.denx.de/twiki/bin/view/DULG/Manual ; 3277 Read the source, Luke; 3278 } 3279 3280 if (available_money > toLocalCurrency ($2500)) { 3281 Buy a BDI2000; 3282 } else { 3283 Add a lot of aggravation and time; 3284 } 3285 3286 Create your own board support subdirectory; 3287 3288 Create your own board config file; 3289 3290 while (!running) { 3291 do { 3292 Add / modify source code; 3293 } until (compiles); 3294 Debug; 3295 if (clueless) 3296 email ("Hi, I am having problems..."); 3297 } 3298 Send patch file to Wolfgang; 3299 3300 return 0; 3301} 3302 3303void no_more_time (int sig) 3304{ 3305 hire_a_guru(); 3306} 3307 3308 3309Coding Standards: 3310----------------- 3311 3312All contributions to U-Boot should conform to the Linux kernel 3313coding style; see the file "Documentation/CodingStyle" in your Linux 3314kernel source directory. 3315 3316Please note that U-Boot is implemented in C (and to some small parts 3317in Assembler); no C++ is used, so please do not use C++ style 3318comments (//) in your code. 3319 3320Please also stick to the following formatting rules: 3321- remove any trailing white space 3322- use TAB characters for indentation, not spaces 3323- make sure NOT to use DOS '\r\n' line feeds 3324- do not add more than 2 empty lines to source files 3325- do not add trailing empty lines to source files 3326 3327Submissions which do not conform to the standards may be returned 3328with a request to reformat the changes. 3329 3330 3331Submitting Patches: 3332------------------- 3333 3334Since the number of patches for U-Boot is growing, we need to 3335establish some rules. Submissions which do not conform to these rules 3336may be rejected, even when they contain important and valuable stuff. 3337 3338 3339When you send a patch, please include the following information with 3340it: 3341 3342* For bug fixes: a description of the bug and how your patch fixes 3343 this bug. Please try to include a way of demonstrating that the 3344 patch actually fixes something. 3345 3346* For new features: a description of the feature and your 3347 implementation. 3348 3349* A CHANGELOG entry as plaintext (separate from the patch) 3350 3351* For major contributions, your entry to the CREDITS file 3352 3353* When you add support for a new board, don't forget to add this 3354 board to the MAKEALL script, too. 3355 3356* If your patch adds new configuration options, don't forget to 3357 document these in the README file. 3358 3359* The patch itself. If you are accessing the CVS repository use "cvs 3360 update; cvs diff -puRN"; else, use "diff -purN OLD NEW". If your 3361 version of diff does not support these options, then get the latest 3362 version of GNU diff. 3363 3364 The current directory when running this command shall be the top 3365 level directory of the U-Boot source tree, or it's parent directory 3366 (i. e. please make sure that your patch includes sufficient 3367 directory information for the affected files). 3368 3369 We accept patches as plain text, MIME attachments or as uuencoded 3370 gzipped text. 3371 3372* If one logical set of modifications affects or creates several 3373 files, all these changes shall be submitted in a SINGLE patch file. 3374 3375* Changesets that contain different, unrelated modifications shall be 3376 submitted as SEPARATE patches, one patch per changeset. 3377 3378 3379Notes: 3380 3381* Before sending the patch, run the MAKEALL script on your patched 3382 source tree and make sure that no errors or warnings are reported 3383 for any of the boards. 3384 3385* Keep your modifications to the necessary minimum: A patch 3386 containing several unrelated changes or arbitrary reformats will be 3387 returned with a request to re-formatting / split it. 3388 3389* If you modify existing code, make sure that your new code does not 3390 add to the memory footprint of the code ;-) Small is beautiful! 3391 When adding new features, these should compile conditionally only 3392 (using #ifdef), and the resulting code with the new feature 3393 disabled must not need more memory than the old code without your 3394 modification. 3395