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 CONFIG_8xx_GCLK_FREQ - deprecated: CPU clock if 343 get_gclk_freq() cannot work 344 e.g. if there is no 32KHz 345 reference PIT/RTC clock 346 CONFIG_8xx_OSCLK - PLL input clock (either EXTCLK 347 or XTAL/EXTAL) 348 349- 859/866/885 CPU options: (if using a MPC859 or MPC866 or MPC885 CPU): 350 CFG_8xx_CPUCLK_MIN 351 CFG_8xx_CPUCLK_MAX 352 CONFIG_8xx_CPUCLK_DEFAULT 353 See doc/README.MPC866 354 355 CFG_MEASURE_CPUCLK 356 357 Define this to measure the actual CPU clock instead 358 of relying on the correctness of the configured 359 values. Mostly useful for board bringup to make sure 360 the PLL is locked at the intended frequency. Note 361 that this requires a (stable) reference clock (32 kHz 362 RTC clock or CFG_8XX_XIN) 363 364- Linux Kernel Interface: 365 CONFIG_CLOCKS_IN_MHZ 366 367 U-Boot stores all clock information in Hz 368 internally. For binary compatibility with older Linux 369 kernels (which expect the clocks passed in the 370 bd_info data to be in MHz) the environment variable 371 "clocks_in_mhz" can be defined so that U-Boot 372 converts clock data to MHZ before passing it to the 373 Linux kernel. 374 When CONFIG_CLOCKS_IN_MHZ is defined, a definition of 375 "clocks_in_mhz=1" is automatically included in the 376 default environment. 377 378 CONFIG_MEMSIZE_IN_BYTES [relevant for MIPS only] 379 380 When transfering memsize parameter to linux, some versions 381 expect it to be in bytes, others in MB. 382 Define CONFIG_MEMSIZE_IN_BYTES to make it in bytes. 383 384- Serial Ports: 385 CFG_PL010_SERIAL 386 387 Define this if you want support for Amba PrimeCell PL010 UARTs. 388 389 CFG_PL011_SERIAL 390 391 Define this if you want support for Amba PrimeCell PL011 UARTs. 392 393 CONFIG_PL011_CLOCK 394 395 If you have Amba PrimeCell PL011 UARTs, set this variable to 396 the clock speed of the UARTs. 397 398 CONFIG_PL01x_PORTS 399 400 If you have Amba PrimeCell PL010 or PL011 UARTs on your board, 401 define this to a list of base addresses for each (supported) 402 port. See e.g. include/configs/versatile.h 403 404 405- Console Interface: 406 Depending on board, define exactly one serial port 407 (like CONFIG_8xx_CONS_SMC1, CONFIG_8xx_CONS_SMC2, 408 CONFIG_8xx_CONS_SCC1, ...), or switch off the serial 409 console by defining CONFIG_8xx_CONS_NONE 410 411 Note: if CONFIG_8xx_CONS_NONE is defined, the serial 412 port routines must be defined elsewhere 413 (i.e. serial_init(), serial_getc(), ...) 414 415 CONFIG_CFB_CONSOLE 416 Enables console device for a color framebuffer. Needs following 417 defines (cf. smiLynxEM, i8042, board/eltec/bab7xx) 418 VIDEO_FB_LITTLE_ENDIAN graphic memory organisation 419 (default big endian) 420 VIDEO_HW_RECTFILL graphic chip supports 421 rectangle fill 422 (cf. smiLynxEM) 423 VIDEO_HW_BITBLT graphic chip supports 424 bit-blit (cf. smiLynxEM) 425 VIDEO_VISIBLE_COLS visible pixel columns 426 (cols=pitch) 427 VIDEO_VISIBLE_ROWS visible pixel rows 428 VIDEO_PIXEL_SIZE bytes per pixel 429 VIDEO_DATA_FORMAT graphic data format 430 (0-5, cf. cfb_console.c) 431 VIDEO_FB_ADRS framebuffer address 432 VIDEO_KBD_INIT_FCT keyboard int fct 433 (i.e. i8042_kbd_init()) 434 VIDEO_TSTC_FCT test char fct 435 (i.e. i8042_tstc) 436 VIDEO_GETC_FCT get char fct 437 (i.e. i8042_getc) 438 CONFIG_CONSOLE_CURSOR cursor drawing on/off 439 (requires blink timer 440 cf. i8042.c) 441 CFG_CONSOLE_BLINK_COUNT blink interval (cf. i8042.c) 442 CONFIG_CONSOLE_TIME display time/date info in 443 upper right corner 444 (requires CFG_CMD_DATE) 445 CONFIG_VIDEO_LOGO display Linux logo in 446 upper left corner 447 CONFIG_VIDEO_BMP_LOGO use bmp_logo.h instead of 448 linux_logo.h for logo. 449 Requires CONFIG_VIDEO_LOGO 450 CONFIG_CONSOLE_EXTRA_INFO 451 addional board info beside 452 the logo 453 454 When CONFIG_CFB_CONSOLE is defined, video console is 455 default i/o. Serial console can be forced with 456 environment 'console=serial'. 457 458 When CONFIG_SILENT_CONSOLE is defined, all console 459 messages (by U-Boot and Linux!) can be silenced with 460 the "silent" environment variable. See 461 doc/README.silent for more information. 462 463- Console Baudrate: 464 CONFIG_BAUDRATE - in bps 465 Select one of the baudrates listed in 466 CFG_BAUDRATE_TABLE, see below. 467 CFG_BRGCLK_PRESCALE, baudrate prescale 468 469- Interrupt driven serial port input: 470 CONFIG_SERIAL_SOFTWARE_FIFO 471 472 PPC405GP only. 473 Use an interrupt handler for receiving data on the 474 serial port. It also enables using hardware handshake 475 (RTS/CTS) and UART's built-in FIFO. Set the number of 476 bytes the interrupt driven input buffer should have. 477 478 Leave undefined to disable this feature, including 479 disable the buffer and hardware handshake. 480 481- Console UART Number: 482 CONFIG_UART1_CONSOLE 483 484 IBM PPC4xx only. 485 If defined internal UART1 (and not UART0) is used 486 as default U-Boot console. 487 488- Boot Delay: CONFIG_BOOTDELAY - in seconds 489 Delay before automatically booting the default image; 490 set to -1 to disable autoboot. 491 492 See doc/README.autoboot for these options that 493 work with CONFIG_BOOTDELAY. None are required. 494 CONFIG_BOOT_RETRY_TIME 495 CONFIG_BOOT_RETRY_MIN 496 CONFIG_AUTOBOOT_KEYED 497 CONFIG_AUTOBOOT_PROMPT 498 CONFIG_AUTOBOOT_DELAY_STR 499 CONFIG_AUTOBOOT_STOP_STR 500 CONFIG_AUTOBOOT_DELAY_STR2 501 CONFIG_AUTOBOOT_STOP_STR2 502 CONFIG_ZERO_BOOTDELAY_CHECK 503 CONFIG_RESET_TO_RETRY 504 505- Autoboot Command: 506 CONFIG_BOOTCOMMAND 507 Only needed when CONFIG_BOOTDELAY is enabled; 508 define a command string that is automatically executed 509 when no character is read on the console interface 510 within "Boot Delay" after reset. 511 512 CONFIG_BOOTARGS 513 This can be used to pass arguments to the bootm 514 command. The value of CONFIG_BOOTARGS goes into the 515 environment value "bootargs". 516 517 CONFIG_RAMBOOT and CONFIG_NFSBOOT 518 The value of these goes into the environment as 519 "ramboot" and "nfsboot" respectively, and can be used 520 as a convenience, when switching between booting from 521 ram and nfs. 522 523- Pre-Boot Commands: 524 CONFIG_PREBOOT 525 526 When this option is #defined, the existence of the 527 environment variable "preboot" will be checked 528 immediately before starting the CONFIG_BOOTDELAY 529 countdown and/or running the auto-boot command resp. 530 entering interactive mode. 531 532 This feature is especially useful when "preboot" is 533 automatically generated or modified. For an example 534 see the LWMON board specific code: here "preboot" is 535 modified when the user holds down a certain 536 combination of keys on the (special) keyboard when 537 booting the systems 538 539- Serial Download Echo Mode: 540 CONFIG_LOADS_ECHO 541 If defined to 1, all characters received during a 542 serial download (using the "loads" command) are 543 echoed back. This might be needed by some terminal 544 emulations (like "cu"), but may as well just take 545 time on others. This setting #define's the initial 546 value of the "loads_echo" environment variable. 547 548- Kgdb Serial Baudrate: (if CFG_CMD_KGDB is defined) 549 CONFIG_KGDB_BAUDRATE 550 Select one of the baudrates listed in 551 CFG_BAUDRATE_TABLE, see below. 552 553- Monitor Functions: 554 CONFIG_COMMANDS 555 Most monitor functions can be selected (or 556 de-selected) by adjusting the definition of 557 CONFIG_COMMANDS; to select individual functions, 558 #define CONFIG_COMMANDS by "OR"ing any of the 559 following values: 560 561 #define enables commands: 562 ------------------------- 563 CFG_CMD_ASKENV * ask for env variable 564 CFG_CMD_AUTOSCRIPT Autoscript Support 565 CFG_CMD_BDI bdinfo 566 CFG_CMD_BEDBUG * Include BedBug Debugger 567 CFG_CMD_BMP * BMP support 568 CFG_CMD_BSP * Board specific commands 569 CFG_CMD_BOOTD bootd 570 CFG_CMD_CACHE * icache, dcache 571 CFG_CMD_CONSOLE coninfo 572 CFG_CMD_DATE * support for RTC, date/time... 573 CFG_CMD_DHCP * DHCP support 574 CFG_CMD_DIAG * Diagnostics 575 CFG_CMD_DOC * Disk-On-Chip Support 576 CFG_CMD_DTT * Digital Therm and Thermostat 577 CFG_CMD_ECHO * echo arguments 578 CFG_CMD_EEPROM * EEPROM read/write support 579 CFG_CMD_ELF * bootelf, bootvx 580 CFG_CMD_ENV saveenv 581 CFG_CMD_FDC * Floppy Disk Support 582 CFG_CMD_FAT * FAT partition support 583 CFG_CMD_FDOS * Dos diskette Support 584 CFG_CMD_FLASH flinfo, erase, protect 585 CFG_CMD_FPGA FPGA device initialization support 586 CFG_CMD_HWFLOW * RTS/CTS hw flow control 587 CFG_CMD_I2C * I2C serial bus support 588 CFG_CMD_IDE * IDE harddisk support 589 CFG_CMD_IMI iminfo 590 CFG_CMD_IMLS List all found images 591 CFG_CMD_IMMAP * IMMR dump support 592 CFG_CMD_IRQ * irqinfo 593 CFG_CMD_ITEST Integer/string test of 2 values 594 CFG_CMD_JFFS2 * JFFS2 Support 595 CFG_CMD_KGDB * kgdb 596 CFG_CMD_LOADB loadb 597 CFG_CMD_LOADS loads 598 CFG_CMD_MEMORY md, mm, nm, mw, cp, cmp, crc, base, 599 loop, loopw, mtest 600 CFG_CMD_MISC Misc functions like sleep etc 601 CFG_CMD_MMC * MMC memory mapped support 602 CFG_CMD_MII * MII utility commands 603 CFG_CMD_NAND * NAND support 604 CFG_CMD_NET bootp, tftpboot, rarpboot 605 CFG_CMD_PCI * pciinfo 606 CFG_CMD_PCMCIA * PCMCIA support 607 CFG_CMD_PING * send ICMP ECHO_REQUEST to network host 608 CFG_CMD_PORTIO * Port I/O 609 CFG_CMD_REGINFO * Register dump 610 CFG_CMD_RUN run command in env variable 611 CFG_CMD_SAVES * save S record dump 612 CFG_CMD_SCSI * SCSI Support 613 CFG_CMD_SDRAM * print SDRAM configuration information 614 CFG_CMD_SETGETDCR Support for DCR Register access (4xx only) 615 CFG_CMD_SPI * SPI serial bus support 616 CFG_CMD_USB * USB support 617 CFG_CMD_VFD * VFD support (TRAB) 618 CFG_CMD_BSP * Board SPecific functions 619 CFG_CMD_CDP * Cisco Discover Protocol support 620 ----------------------------------------------- 621 CFG_CMD_ALL all 622 623 CONFIG_CMD_DFL Default configuration; at the moment 624 this is includes all commands, except 625 the ones marked with "*" in the list 626 above. 627 628 If you don't define CONFIG_COMMANDS it defaults to 629 CONFIG_CMD_DFL in include/cmd_confdefs.h. A board can 630 override the default settings in the respective 631 include file. 632 633 EXAMPLE: If you want all functions except of network 634 support you can write: 635 636 #define CONFIG_COMMANDS (CFG_CMD_ALL & ~CFG_CMD_NET) 637 638 639 Note: Don't enable the "icache" and "dcache" commands 640 (configuration option CFG_CMD_CACHE) unless you know 641 what you (and your U-Boot users) are doing. Data 642 cache cannot be enabled on systems like the 8xx or 643 8260 (where accesses to the IMMR region must be 644 uncached), and it cannot be disabled on all other 645 systems where we (mis-) use the data cache to hold an 646 initial stack and some data. 647 648 649 XXX - this list needs to get updated! 650 651- Watchdog: 652 CONFIG_WATCHDOG 653 If this variable is defined, it enables watchdog 654 support. There must be support in the platform specific 655 code for a watchdog. For the 8xx and 8260 CPUs, the 656 SIU Watchdog feature is enabled in the SYPCR 657 register. 658 659- U-Boot Version: 660 CONFIG_VERSION_VARIABLE 661 If this variable is defined, an environment variable 662 named "ver" is created by U-Boot showing the U-Boot 663 version as printed by the "version" command. 664 This variable is readonly. 665 666- Real-Time Clock: 667 668 When CFG_CMD_DATE is selected, the type of the RTC 669 has to be selected, too. Define exactly one of the 670 following options: 671 672 CONFIG_RTC_MPC8xx - use internal RTC of MPC8xx 673 CONFIG_RTC_PCF8563 - use Philips PCF8563 RTC 674 CONFIG_RTC_MC146818 - use MC146818 RTC 675 CONFIG_RTC_DS1307 - use Maxim, Inc. DS1307 RTC 676 CONFIG_RTC_DS1337 - use Maxim, Inc. DS1337 RTC 677 CONFIG_RTC_DS1338 - use Maxim, Inc. DS1338 RTC 678 CONFIG_RTC_DS164x - use Dallas DS164x RTC 679 CONFIG_RTC_MAX6900 - use Maxim, Inc. MAX6900 RTC 680 681 Note that if the RTC uses I2C, then the I2C interface 682 must also be configured. See I2C Support, below. 683 684- Timestamp Support: 685 686 When CONFIG_TIMESTAMP is selected, the timestamp 687 (date and time) of an image is printed by image 688 commands like bootm or iminfo. This option is 689 automatically enabled when you select CFG_CMD_DATE . 690 691- Partition Support: 692 CONFIG_MAC_PARTITION and/or CONFIG_DOS_PARTITION 693 and/or CONFIG_ISO_PARTITION 694 695 If IDE or SCSI support is enabled (CFG_CMD_IDE or 696 CFG_CMD_SCSI) you must configure support for at least 697 one partition type as well. 698 699- IDE Reset method: 700 CONFIG_IDE_RESET_ROUTINE - this is defined in several 701 board configurations files but used nowhere! 702 703 CONFIG_IDE_RESET - is this is defined, IDE Reset will 704 be performed by calling the function 705 ide_set_reset(int reset) 706 which has to be defined in a board specific file 707 708- ATAPI Support: 709 CONFIG_ATAPI 710 711 Set this to enable ATAPI support. 712 713- LBA48 Support 714 CONFIG_LBA48 715 716 Set this to enable support for disks larger than 137GB 717 Also look at CFG_64BIT_LBA ,CFG_64BIT_VSPRINTF and CFG_64BIT_STRTOUL 718 Whithout these , LBA48 support uses 32bit variables and will 'only' 719 support disks up to 2.1TB. 720 721 CFG_64BIT_LBA: 722 When enabled, makes the IDE subsystem use 64bit sector addresses. 723 Default is 32bit. 724 725- SCSI Support: 726 At the moment only there is only support for the 727 SYM53C8XX SCSI controller; define 728 CONFIG_SCSI_SYM53C8XX to enable it. 729 730 CFG_SCSI_MAX_LUN [8], CFG_SCSI_MAX_SCSI_ID [7] and 731 CFG_SCSI_MAX_DEVICE [CFG_SCSI_MAX_SCSI_ID * 732 CFG_SCSI_MAX_LUN] can be adjusted to define the 733 maximum numbers of LUNs, SCSI ID's and target 734 devices. 735 CFG_SCSI_SYM53C8XX_CCF to fix clock timing (80Mhz) 736 737- NETWORK Support (PCI): 738 CONFIG_E1000 739 Support for Intel 8254x gigabit chips. 740 741 CONFIG_EEPRO100 742 Support for Intel 82557/82559/82559ER chips. 743 Optional CONFIG_EEPRO100_SROM_WRITE enables eeprom 744 write routine for first time initialisation. 745 746 CONFIG_TULIP 747 Support for Digital 2114x chips. 748 Optional CONFIG_TULIP_SELECT_MEDIA for board specific 749 modem chip initialisation (KS8761/QS6611). 750 751 CONFIG_NATSEMI 752 Support for National dp83815 chips. 753 754 CONFIG_NS8382X 755 Support for National dp8382[01] gigabit chips. 756 757- NETWORK Support (other): 758 759 CONFIG_DRIVER_LAN91C96 760 Support for SMSC's LAN91C96 chips. 761 762 CONFIG_LAN91C96_BASE 763 Define this to hold the physical address 764 of the LAN91C96's I/O space 765 766 CONFIG_LAN91C96_USE_32_BIT 767 Define this to enable 32 bit addressing 768 769 CONFIG_DRIVER_SMC91111 770 Support for SMSC's LAN91C111 chip 771 772 CONFIG_SMC91111_BASE 773 Define this to hold the physical address 774 of the device (I/O space) 775 776 CONFIG_SMC_USE_32_BIT 777 Define this if data bus is 32 bits 778 779 CONFIG_SMC_USE_IOFUNCS 780 Define this to use i/o functions instead of macros 781 (some hardware wont work with macros) 782 783- USB Support: 784 At the moment only the UHCI host controller is 785 supported (PIP405, MIP405, MPC5200); define 786 CONFIG_USB_UHCI to enable it. 787 define CONFIG_USB_KEYBOARD to enable the USB Keyboard 788 end define CONFIG_USB_STORAGE to enable the USB 789 storage devices. 790 Note: 791 Supported are USB Keyboards and USB Floppy drives 792 (TEAC FD-05PUB). 793 MPC5200 USB requires additional defines: 794 CONFIG_USB_CLOCK 795 for 528 MHz Clock: 0x0001bbbb 796 CONFIG_USB_CONFIG 797 for differential drivers: 0x00001000 798 for single ended drivers: 0x00005000 799 800 801- MMC Support: 802 The MMC controller on the Intel PXA is supported. To 803 enable this define CONFIG_MMC. The MMC can be 804 accessed from the boot prompt by mapping the device 805 to physical memory similar to flash. Command line is 806 enabled with CFG_CMD_MMC. The MMC driver also works with 807 the FAT fs. This is enabled with CFG_CMD_FAT. 808 809- Journaling Flash filesystem support: 810 CONFIG_JFFS2_NAND, CONFIG_JFFS2_NAND_OFF, CONFIG_JFFS2_NAND_SIZE, 811 CONFIG_JFFS2_NAND_DEV 812 Define these for a default partition on a NAND device 813 814 CFG_JFFS2_FIRST_SECTOR, 815 CFG_JFFS2_FIRST_BANK, CFG_JFFS2_NUM_BANKS 816 Define these for a default partition on a NOR device 817 818 CFG_JFFS_CUSTOM_PART 819 Define this to create an own partition. You have to provide a 820 function struct part_info* jffs2_part_info(int part_num) 821 822 If you define only one JFFS2 partition you may also want to 823 #define CFG_JFFS_SINGLE_PART 1 824 to disable the command chpart. This is the default when you 825 have not defined a custom partition 826 827- Keyboard Support: 828 CONFIG_ISA_KEYBOARD 829 830 Define this to enable standard (PC-Style) keyboard 831 support 832 833 CONFIG_I8042_KBD 834 Standard PC keyboard driver with US (is default) and 835 GERMAN key layout (switch via environment 'keymap=de') support. 836 Export function i8042_kbd_init, i8042_tstc and i8042_getc 837 for cfb_console. Supports cursor blinking. 838 839- Video support: 840 CONFIG_VIDEO 841 842 Define this to enable video support (for output to 843 video). 844 845 CONFIG_VIDEO_CT69000 846 847 Enable Chips & Technologies 69000 Video chip 848 849 CONFIG_VIDEO_SMI_LYNXEM 850 Enable Silicon Motion SMI 712/710/810 Video chip. The 851 video output is selected via environment 'videoout' 852 (1 = LCD and 2 = CRT). If videoout is undefined, CRT is 853 assumed. 854 855 For the CT69000 and SMI_LYNXEM drivers, videomode is 856 selected via environment 'videomode'. Two diferent ways 857 are possible: 858 - "videomode=num" 'num' is a standard LiLo mode numbers. 859 Following standard modes are supported (* is default): 860 861 Colors 640x480 800x600 1024x768 1152x864 1280x1024 862 -------------+--------------------------------------------- 863 8 bits | 0x301* 0x303 0x305 0x161 0x307 864 15 bits | 0x310 0x313 0x316 0x162 0x319 865 16 bits | 0x311 0x314 0x317 0x163 0x31A 866 24 bits | 0x312 0x315 0x318 ? 0x31B 867 -------------+--------------------------------------------- 868 (i.e. setenv videomode 317; saveenv; reset;) 869 870 - "videomode=bootargs" all the video parameters are parsed 871 from the bootargs. (See drivers/videomodes.c) 872 873 874 CONFIG_VIDEO_SED13806 875 Enable Epson SED13806 driver. This driver supports 8bpp 876 and 16bpp modes defined by CONFIG_VIDEO_SED13806_8BPP 877 or CONFIG_VIDEO_SED13806_16BPP 878 879- Keyboard Support: 880 CONFIG_KEYBOARD 881 882 Define this to enable a custom keyboard support. 883 This simply calls drv_keyboard_init() which must be 884 defined in your board-specific files. 885 The only board using this so far is RBC823. 886 887- LCD Support: CONFIG_LCD 888 889 Define this to enable LCD support (for output to LCD 890 display); also select one of the supported displays 891 by defining one of these: 892 893 CONFIG_NEC_NL6448AC33: 894 895 NEC NL6448AC33-18. Active, color, single scan. 896 897 CONFIG_NEC_NL6448BC20 898 899 NEC NL6448BC20-08. 6.5", 640x480. 900 Active, color, single scan. 901 902 CONFIG_NEC_NL6448BC33_54 903 904 NEC NL6448BC33-54. 10.4", 640x480. 905 Active, color, single scan. 906 907 CONFIG_SHARP_16x9 908 909 Sharp 320x240. Active, color, single scan. 910 It isn't 16x9, and I am not sure what it is. 911 912 CONFIG_SHARP_LQ64D341 913 914 Sharp LQ64D341 display, 640x480. 915 Active, color, single scan. 916 917 CONFIG_HLD1045 918 919 HLD1045 display, 640x480. 920 Active, color, single scan. 921 922 CONFIG_OPTREX_BW 923 924 Optrex CBL50840-2 NF-FW 99 22 M5 925 or 926 Hitachi LMG6912RPFC-00T 927 or 928 Hitachi SP14Q002 929 930 320x240. Black & white. 931 932 Normally display is black on white background; define 933 CFG_WHITE_ON_BLACK to get it inverted. 934 935- Splash Screen Support: CONFIG_SPLASH_SCREEN 936 937 If this option is set, the environment is checked for 938 a variable "splashimage". If found, the usual display 939 of logo, copyright and system information on the LCD 940 is suppressed and the BMP image at the address 941 specified in "splashimage" is loaded instead. The 942 console is redirected to the "nulldev", too. This 943 allows for a "silent" boot where a splash screen is 944 loaded very quickly after power-on. 945 946- Compression support: 947 CONFIG_BZIP2 948 949 If this option is set, support for bzip2 compressed 950 images is included. If not, only uncompressed and gzip 951 compressed images are supported. 952 953 NOTE: the bzip2 algorithm requires a lot of RAM, so 954 the malloc area (as defined by CFG_MALLOC_LEN) should 955 be at least 4MB. 956 957- MII/PHY support: 958 CONFIG_PHY_ADDR 959 960 The address of PHY on MII bus. 961 962 CONFIG_PHY_CLOCK_FREQ (ppc4xx) 963 964 The clock frequency of the MII bus 965 966 CONFIG_PHY_GIGE 967 968 If this option is set, support for speed/duplex 969 detection of Gigabit PHY is included. 970 971 CONFIG_PHY_RESET_DELAY 972 973 Some PHY like Intel LXT971A need extra delay after 974 reset before any MII register access is possible. 975 For such PHY, set this option to the usec delay 976 required. (minimum 300usec for LXT971A) 977 978 CONFIG_PHY_CMD_DELAY (ppc4xx) 979 980 Some PHY like Intel LXT971A need extra delay after 981 command issued before MII status register can be read 982 983- Ethernet address: 984 CONFIG_ETHADDR 985 CONFIG_ETH2ADDR 986 CONFIG_ETH3ADDR 987 988 Define a default value for ethernet address to use 989 for the respective ethernet interface, in case this 990 is not determined automatically. 991 992- IP address: 993 CONFIG_IPADDR 994 995 Define a default value for the IP address to use for 996 the default ethernet interface, in case this is not 997 determined through e.g. bootp. 998 999- Server IP address: 1000 CONFIG_SERVERIP 1001 1002 Defines a default value for theIP address of a TFTP 1003 server to contact when using the "tftboot" command. 1004 1005- BOOTP Recovery Mode: 1006 CONFIG_BOOTP_RANDOM_DELAY 1007 1008 If you have many targets in a network that try to 1009 boot using BOOTP, you may want to avoid that all 1010 systems send out BOOTP requests at precisely the same 1011 moment (which would happen for instance at recovery 1012 from a power failure, when all systems will try to 1013 boot, thus flooding the BOOTP server. Defining 1014 CONFIG_BOOTP_RANDOM_DELAY causes a random delay to be 1015 inserted before sending out BOOTP requests. The 1016 following delays are insterted then: 1017 1018 1st BOOTP request: delay 0 ... 1 sec 1019 2nd BOOTP request: delay 0 ... 2 sec 1020 3rd BOOTP request: delay 0 ... 4 sec 1021 4th and following 1022 BOOTP requests: delay 0 ... 8 sec 1023 1024- DHCP Advanced Options: 1025 CONFIG_BOOTP_MASK 1026 1027 You can fine tune the DHCP functionality by adding 1028 these flags to the CONFIG_BOOTP_MASK define: 1029 1030 CONFIG_BOOTP_DNS2 - If a DHCP client requests the DNS 1031 serverip from a DHCP server, it is possible that more 1032 than one DNS serverip is offered to the client. 1033 If CONFIG_BOOTP_DNS2 is enabled, the secondary DNS 1034 serverip will be stored in the additional environment 1035 variable "dnsip2". The first DNS serverip is always 1036 stored in the variable "dnsip", when CONFIG_BOOTP_DNS 1037 is added to the CONFIG_BOOTP_MASK. 1038 1039 CONFIG_BOOTP_SEND_HOSTNAME - Some DHCP servers are capable 1040 to do a dynamic update of a DNS server. To do this, they 1041 need the hostname of the DHCP requester. 1042 If CONFIG_BOOP_SEND_HOSTNAME is added to the 1043 CONFIG_BOOTP_MASK, the content of the "hostname" 1044 environment variable is passed as option 12 to 1045 the DHCP server. 1046 1047 - CDP Options: 1048 CONFIG_CDP_DEVICE_ID 1049 1050 The device id used in CDP trigger frames. 1051 1052 CONFIG_CDP_DEVICE_ID_PREFIX 1053 1054 A two character string which is prefixed to the MAC address 1055 of the device. 1056 1057 CONFIG_CDP_PORT_ID 1058 1059 A printf format string which contains the ascii name of 1060 the port. Normally is set to "eth%d" which sets 1061 eth0 for the first ethernet, eth1 for the second etc. 1062 1063 CONFIG_CDP_CAPABILITIES 1064 1065 A 32bit integer which indicates the device capabilities; 1066 0x00000010 for a normal host which does not forwards. 1067 1068 CONFIG_CDP_VERSION 1069 1070 An ascii string containing the version of the software. 1071 1072 CONFIG_CDP_PLATFORM 1073 1074 An ascii string containing the name of the platform. 1075 1076 CONFIG_CDP_TRIGGER 1077 1078 A 32bit integer sent on the trigger. 1079 1080 CONFIG_CDP_POWER_CONSUMPTION 1081 1082 A 16bit integer containing the power consumption of the 1083 device in .1 of milliwatts. 1084 1085 CONFIG_CDP_APPLIANCE_VLAN_TYPE 1086 1087 A byte containing the id of the VLAN. 1088 1089- Status LED: CONFIG_STATUS_LED 1090 1091 Several configurations allow to display the current 1092 status using a LED. For instance, the LED will blink 1093 fast while running U-Boot code, stop blinking as 1094 soon as a reply to a BOOTP request was received, and 1095 start blinking slow once the Linux kernel is running 1096 (supported by a status LED driver in the Linux 1097 kernel). Defining CONFIG_STATUS_LED enables this 1098 feature in U-Boot. 1099 1100- CAN Support: CONFIG_CAN_DRIVER 1101 1102 Defining CONFIG_CAN_DRIVER enables CAN driver support 1103 on those systems that support this (optional) 1104 feature, like the TQM8xxL modules. 1105 1106- I2C Support: CONFIG_HARD_I2C | CONFIG_SOFT_I2C 1107 1108 These enable I2C serial bus commands. Defining either of 1109 (but not both of) CONFIG_HARD_I2C or CONFIG_SOFT_I2C will 1110 include the appropriate I2C driver for the selected cpu. 1111 1112 This will allow you to use i2c commands at the u-boot 1113 command line (as long as you set CFG_CMD_I2C in 1114 CONFIG_COMMANDS) and communicate with i2c based realtime 1115 clock chips. See common/cmd_i2c.c for a description of the 1116 command line interface. 1117 1118 CONFIG_HARD_I2C selects the CPM hardware driver for I2C. 1119 1120 CONFIG_SOFT_I2C configures u-boot to use a software (aka 1121 bit-banging) driver instead of CPM or similar hardware 1122 support for I2C. 1123 1124 There are several other quantities that must also be 1125 defined when you define CONFIG_HARD_I2C or CONFIG_SOFT_I2C. 1126 1127 In both cases you will need to define CFG_I2C_SPEED 1128 to be the frequency (in Hz) at which you wish your i2c bus 1129 to run and CFG_I2C_SLAVE to be the address of this node (ie 1130 the cpu's i2c node address). 1131 1132 Now, the u-boot i2c code for the mpc8xx (cpu/mpc8xx/i2c.c) 1133 sets the cpu up as a master node and so its address should 1134 therefore be cleared to 0 (See, eg, MPC823e User's Manual 1135 p.16-473). So, set CFG_I2C_SLAVE to 0. 1136 1137 That's all that's required for CONFIG_HARD_I2C. 1138 1139 If you use the software i2c interface (CONFIG_SOFT_I2C) 1140 then the following macros need to be defined (examples are 1141 from include/configs/lwmon.h): 1142 1143 I2C_INIT 1144 1145 (Optional). Any commands necessary to enable the I2C 1146 controller or configure ports. 1147 1148 eg: #define I2C_INIT (immr->im_cpm.cp_pbdir |= PB_SCL) 1149 1150 I2C_PORT 1151 1152 (Only for MPC8260 CPU). The I/O port to use (the code 1153 assumes both bits are on the same port). Valid values 1154 are 0..3 for ports A..D. 1155 1156 I2C_ACTIVE 1157 1158 The code necessary to make the I2C data line active 1159 (driven). If the data line is open collector, this 1160 define can be null. 1161 1162 eg: #define I2C_ACTIVE (immr->im_cpm.cp_pbdir |= PB_SDA) 1163 1164 I2C_TRISTATE 1165 1166 The code necessary to make the I2C data line tri-stated 1167 (inactive). If the data line is open collector, this 1168 define can be null. 1169 1170 eg: #define I2C_TRISTATE (immr->im_cpm.cp_pbdir &= ~PB_SDA) 1171 1172 I2C_READ 1173 1174 Code that returns TRUE if the I2C data line is high, 1175 FALSE if it is low. 1176 1177 eg: #define I2C_READ ((immr->im_cpm.cp_pbdat & PB_SDA) != 0) 1178 1179 I2C_SDA(bit) 1180 1181 If <bit> is TRUE, sets the I2C data line high. If it 1182 is FALSE, it clears it (low). 1183 1184 eg: #define I2C_SDA(bit) \ 1185 if(bit) immr->im_cpm.cp_pbdat |= PB_SDA; \ 1186 else immr->im_cpm.cp_pbdat &= ~PB_SDA 1187 1188 I2C_SCL(bit) 1189 1190 If <bit> is TRUE, sets the I2C clock line high. If it 1191 is FALSE, it clears it (low). 1192 1193 eg: #define I2C_SCL(bit) \ 1194 if(bit) immr->im_cpm.cp_pbdat |= PB_SCL; \ 1195 else immr->im_cpm.cp_pbdat &= ~PB_SCL 1196 1197 I2C_DELAY 1198 1199 This delay is invoked four times per clock cycle so this 1200 controls the rate of data transfer. The data rate thus 1201 is 1 / (I2C_DELAY * 4). Often defined to be something 1202 like: 1203 1204 #define I2C_DELAY udelay(2) 1205 1206 CFG_I2C_INIT_BOARD 1207 1208 When a board is reset during an i2c bus transfer 1209 chips might think that the current transfer is still 1210 in progress. On some boards it is possible to access 1211 the i2c SCLK line directly, either by using the 1212 processor pin as a GPIO or by having a second pin 1213 connected to the bus. If this option is defined a 1214 custom i2c_init_board() routine in boards/xxx/board.c 1215 is run early in the boot sequence. 1216 1217 CONFIG_I2CFAST (PPC405GP|PPC405EP only) 1218 1219 This option enables configuration of bi_iic_fast[] flags 1220 in u-boot bd_info structure based on u-boot environment 1221 variable "i2cfast". (see also i2cfast) 1222 1223- SPI Support: CONFIG_SPI 1224 1225 Enables SPI driver (so far only tested with 1226 SPI EEPROM, also an instance works with Crystal A/D and 1227 D/As on the SACSng board) 1228 1229 CONFIG_SPI_X 1230 1231 Enables extended (16-bit) SPI EEPROM addressing. 1232 (symmetrical to CONFIG_I2C_X) 1233 1234 CONFIG_SOFT_SPI 1235 1236 Enables a software (bit-bang) SPI driver rather than 1237 using hardware support. This is a general purpose 1238 driver that only requires three general I/O port pins 1239 (two outputs, one input) to function. If this is 1240 defined, the board configuration must define several 1241 SPI configuration items (port pins to use, etc). For 1242 an example, see include/configs/sacsng.h. 1243 1244- FPGA Support: CONFIG_FPGA_COUNT 1245 1246 Specify the number of FPGA devices to support. 1247 1248 CONFIG_FPGA 1249 1250 Used to specify the types of FPGA devices. For example, 1251 #define CONFIG_FPGA CFG_XILINX_VIRTEX2 1252 1253 CFG_FPGA_PROG_FEEDBACK 1254 1255 Enable printing of hash marks during FPGA configuration. 1256 1257 CFG_FPGA_CHECK_BUSY 1258 1259 Enable checks on FPGA configuration interface busy 1260 status by the configuration function. This option 1261 will require a board or device specific function to 1262 be written. 1263 1264 CONFIG_FPGA_DELAY 1265 1266 If defined, a function that provides delays in the FPGA 1267 configuration driver. 1268 1269 CFG_FPGA_CHECK_CTRLC 1270 Allow Control-C to interrupt FPGA configuration 1271 1272 CFG_FPGA_CHECK_ERROR 1273 1274 Check for configuration errors during FPGA bitfile 1275 loading. For example, abort during Virtex II 1276 configuration if the INIT_B line goes low (which 1277 indicated a CRC error). 1278 1279 CFG_FPGA_WAIT_INIT 1280 1281 Maximum time to wait for the INIT_B line to deassert 1282 after PROB_B has been deasserted during a Virtex II 1283 FPGA configuration sequence. The default time is 500 1284 mS. 1285 1286 CFG_FPGA_WAIT_BUSY 1287 1288 Maximum time to wait for BUSY to deassert during 1289 Virtex II FPGA configuration. The default is 5 mS. 1290 1291 CFG_FPGA_WAIT_CONFIG 1292 1293 Time to wait after FPGA configuration. The default is 1294 200 mS. 1295 1296- Configuration Management: 1297 CONFIG_IDENT_STRING 1298 1299 If defined, this string will be added to the U-Boot 1300 version information (U_BOOT_VERSION) 1301 1302- Vendor Parameter Protection: 1303 1304 U-Boot considers the values of the environment 1305 variables "serial#" (Board Serial Number) and 1306 "ethaddr" (Ethernet Address) to be parameters that 1307 are set once by the board vendor / manufacturer, and 1308 protects these variables from casual modification by 1309 the user. Once set, these variables are read-only, 1310 and write or delete attempts are rejected. You can 1311 change this behviour: 1312 1313 If CONFIG_ENV_OVERWRITE is #defined in your config 1314 file, the write protection for vendor parameters is 1315 completely disabled. Anybody can change or delete 1316 these parameters. 1317 1318 Alternatively, if you #define _both_ CONFIG_ETHADDR 1319 _and_ CONFIG_OVERWRITE_ETHADDR_ONCE, a default 1320 ethernet address is installed in the environment, 1321 which can be changed exactly ONCE by the user. [The 1322 serial# is unaffected by this, i. e. it remains 1323 read-only.] 1324 1325- Protected RAM: 1326 CONFIG_PRAM 1327 1328 Define this variable to enable the reservation of 1329 "protected RAM", i. e. RAM which is not overwritten 1330 by U-Boot. Define CONFIG_PRAM to hold the number of 1331 kB you want to reserve for pRAM. You can overwrite 1332 this default value by defining an environment 1333 variable "pram" to the number of kB you want to 1334 reserve. Note that the board info structure will 1335 still show the full amount of RAM. If pRAM is 1336 reserved, a new environment variable "mem" will 1337 automatically be defined to hold the amount of 1338 remaining RAM in a form that can be passed as boot 1339 argument to Linux, for instance like that: 1340 1341 setenv bootargs ... mem=\$(mem) 1342 saveenv 1343 1344 This way you can tell Linux not to use this memory, 1345 either, which results in a memory region that will 1346 not be affected by reboots. 1347 1348 *WARNING* If your board configuration uses automatic 1349 detection of the RAM size, you must make sure that 1350 this memory test is non-destructive. So far, the 1351 following board configurations are known to be 1352 "pRAM-clean": 1353 1354 ETX094, IVMS8, IVML24, SPD8xx, TQM8xxL, 1355 HERMES, IP860, RPXlite, LWMON, LANTEC, 1356 PCU_E, FLAGADM, TQM8260 1357 1358- Error Recovery: 1359 CONFIG_PANIC_HANG 1360 1361 Define this variable to stop the system in case of a 1362 fatal error, so that you have to reset it manually. 1363 This is probably NOT a good idea for an embedded 1364 system where you want to system to reboot 1365 automatically as fast as possible, but it may be 1366 useful during development since you can try to debug 1367 the conditions that lead to the situation. 1368 1369 CONFIG_NET_RETRY_COUNT 1370 1371 This variable defines the number of retries for 1372 network operations like ARP, RARP, TFTP, or BOOTP 1373 before giving up the operation. If not defined, a 1374 default value of 5 is used. 1375 1376- Command Interpreter: 1377 CFG_AUTO_COMPLETE 1378 1379 Enable auto completion of commands using TAB. 1380 1381 CFG_HUSH_PARSER 1382 1383 Define this variable to enable the "hush" shell (from 1384 Busybox) as command line interpreter, thus enabling 1385 powerful command line syntax like 1386 if...then...else...fi conditionals or `&&' and '||' 1387 constructs ("shell scripts"). 1388 1389 If undefined, you get the old, much simpler behaviour 1390 with a somewhat smaller memory footprint. 1391 1392 1393 CFG_PROMPT_HUSH_PS2 1394 1395 This defines the secondary prompt string, which is 1396 printed when the command interpreter needs more input 1397 to complete a command. Usually "> ". 1398 1399 Note: 1400 1401 In the current implementation, the local variables 1402 space and global environment variables space are 1403 separated. Local variables are those you define by 1404 simply typing `name=value'. To access a local 1405 variable later on, you have write `$name' or 1406 `${name}'; to execute the contents of a variable 1407 directly type `$name' at the command prompt. 1408 1409 Global environment variables are those you use 1410 setenv/printenv to work with. To run a command stored 1411 in such a variable, you need to use the run command, 1412 and you must not use the '$' sign to access them. 1413 1414 To store commands and special characters in a 1415 variable, please use double quotation marks 1416 surrounding the whole text of the variable, instead 1417 of the backslashes before semicolons and special 1418 symbols. 1419 1420- Default Environment: 1421 CONFIG_EXTRA_ENV_SETTINGS 1422 1423 Define this to contain any number of null terminated 1424 strings (variable = value pairs) that will be part of 1425 the default environment compiled into the boot image. 1426 1427 For example, place something like this in your 1428 board's config file: 1429 1430 #define CONFIG_EXTRA_ENV_SETTINGS \ 1431 "myvar1=value1\0" \ 1432 "myvar2=value2\0" 1433 1434 Warning: This method is based on knowledge about the 1435 internal format how the environment is stored by the 1436 U-Boot code. This is NOT an official, exported 1437 interface! Although it is unlikely that this format 1438 will change soon, there is no guarantee either. 1439 You better know what you are doing here. 1440 1441 Note: overly (ab)use of the default environment is 1442 discouraged. Make sure to check other ways to preset 1443 the environment like the autoscript function or the 1444 boot command first. 1445 1446- DataFlash Support: 1447 CONFIG_HAS_DATAFLASH 1448 1449 Defining this option enables DataFlash features and 1450 allows to read/write in Dataflash via the standard 1451 commands cp, md... 1452 1453- SystemACE Support: 1454 CONFIG_SYSTEMACE 1455 1456 Adding this option adds support for Xilinx SystemACE 1457 chips attached via some sort of local bus. The address 1458 of the chip must alsh be defined in the 1459 CFG_SYSTEMACE_BASE macro. For example: 1460 1461 #define CONFIG_SYSTEMACE 1462 #define CFG_SYSTEMACE_BASE 0xf0000000 1463 1464 When SystemACE support is added, the "ace" device type 1465 becomes available to the fat commands, i.e. fatls. 1466 1467- Show boot progress: 1468 CONFIG_SHOW_BOOT_PROGRESS 1469 1470 Defining this option allows to add some board- 1471 specific code (calling a user-provided function 1472 "show_boot_progress(int)") that enables you to show 1473 the system's boot progress on some display (for 1474 example, some LED's) on your board. At the moment, 1475 the following checkpoints are implemented: 1476 1477 Arg Where When 1478 1 common/cmd_bootm.c before attempting to boot an image 1479 -1 common/cmd_bootm.c Image header has bad magic number 1480 2 common/cmd_bootm.c Image header has correct magic number 1481 -2 common/cmd_bootm.c Image header has bad checksum 1482 3 common/cmd_bootm.c Image header has correct checksum 1483 -3 common/cmd_bootm.c Image data has bad checksum 1484 4 common/cmd_bootm.c Image data has correct checksum 1485 -4 common/cmd_bootm.c Image is for unsupported architecture 1486 5 common/cmd_bootm.c Architecture check OK 1487 -5 common/cmd_bootm.c Wrong Image Type (not kernel, multi, standalone) 1488 6 common/cmd_bootm.c Image Type check OK 1489 -6 common/cmd_bootm.c gunzip uncompression error 1490 -7 common/cmd_bootm.c Unimplemented compression type 1491 7 common/cmd_bootm.c Uncompression OK 1492 -8 common/cmd_bootm.c Wrong Image Type (not kernel, multi, standalone) 1493 8 common/cmd_bootm.c Image Type check OK 1494 -9 common/cmd_bootm.c Unsupported OS (not Linux, BSD, VxWorks, QNX) 1495 9 common/cmd_bootm.c Start initial ramdisk verification 1496 -10 common/cmd_bootm.c Ramdisk header has bad magic number 1497 -11 common/cmd_bootm.c Ramdisk header has bad checksum 1498 10 common/cmd_bootm.c Ramdisk header is OK 1499 -12 common/cmd_bootm.c Ramdisk data has bad checksum 1500 11 common/cmd_bootm.c Ramdisk data has correct checksum 1501 12 common/cmd_bootm.c Ramdisk verification complete, start loading 1502 -13 common/cmd_bootm.c Wrong Image Type (not PPC Linux Ramdisk) 1503 13 common/cmd_bootm.c Start multifile image verification 1504 14 common/cmd_bootm.c No initial ramdisk, no multifile, continue. 1505 15 common/cmd_bootm.c All preparation done, transferring control to OS 1506 1507 -30 lib_ppc/board.c Fatal error, hang the system 1508 -31 post/post.c POST test failed, detected by post_output_backlog() 1509 -32 post/post.c POST test failed, detected by post_run_single() 1510 1511 -1 common/cmd_doc.c Bad usage of "doc" command 1512 -1 common/cmd_doc.c No boot device 1513 -1 common/cmd_doc.c Unknown Chip ID on boot device 1514 -1 common/cmd_doc.c Read Error on boot device 1515 -1 common/cmd_doc.c Image header has bad magic number 1516 1517 -1 common/cmd_ide.c Bad usage of "ide" command 1518 -1 common/cmd_ide.c No boot device 1519 -1 common/cmd_ide.c Unknown boot device 1520 -1 common/cmd_ide.c Unknown partition table 1521 -1 common/cmd_ide.c Invalid partition type 1522 -1 common/cmd_ide.c Read Error on boot device 1523 -1 common/cmd_ide.c Image header has bad magic number 1524 1525 -1 common/cmd_nand.c Bad usage of "nand" command 1526 -1 common/cmd_nand.c No boot device 1527 -1 common/cmd_nand.c Unknown Chip ID on boot device 1528 -1 common/cmd_nand.c Read Error on boot device 1529 -1 common/cmd_nand.c Image header has bad magic number 1530 1531 -1 common/env_common.c Environment has a bad CRC, using default 1532 1533 1534Modem Support: 1535-------------- 1536 1537[so far only for SMDK2400 and TRAB boards] 1538 1539- Modem support endable: 1540 CONFIG_MODEM_SUPPORT 1541 1542- RTS/CTS Flow control enable: 1543 CONFIG_HWFLOW 1544 1545- Modem debug support: 1546 CONFIG_MODEM_SUPPORT_DEBUG 1547 1548 Enables debugging stuff (char screen[1024], dbg()) 1549 for modem support. Useful only with BDI2000. 1550 1551- Interrupt support (PPC): 1552 1553 There are common interrupt_init() and timer_interrupt() 1554 for all PPC archs. interrupt_init() calls interrupt_init_cpu() 1555 for cpu specific initialization. interrupt_init_cpu() 1556 should set decrementer_count to appropriate value. If 1557 cpu resets decrementer automatically after interrupt 1558 (ppc4xx) it should set decrementer_count to zero. 1559 timer_interrupt() calls timer_interrupt_cpu() for cpu 1560 specific handling. If board has watchdog / status_led 1561 / other_activity_monitor it works automatically from 1562 general timer_interrupt(). 1563 1564- General: 1565 1566 In the target system modem support is enabled when a 1567 specific key (key combination) is pressed during 1568 power-on. Otherwise U-Boot will boot normally 1569 (autoboot). The key_pressed() fuction is called from 1570 board_init(). Currently key_pressed() is a dummy 1571 function, returning 1 and thus enabling modem 1572 initialization. 1573 1574 If there are no modem init strings in the 1575 environment, U-Boot proceed to autoboot; the 1576 previous output (banner, info printfs) will be 1577 supressed, though. 1578 1579 See also: doc/README.Modem 1580 1581 1582Configuration Settings: 1583----------------------- 1584 1585- CFG_LONGHELP: Defined when you want long help messages included; 1586 undefine this when you're short of memory. 1587 1588- CFG_PROMPT: This is what U-Boot prints on the console to 1589 prompt for user input. 1590 1591- CFG_CBSIZE: Buffer size for input from the Console 1592 1593- CFG_PBSIZE: Buffer size for Console output 1594 1595- CFG_MAXARGS: max. Number of arguments accepted for monitor commands 1596 1597- CFG_BARGSIZE: Buffer size for Boot Arguments which are passed to 1598 the application (usually a Linux kernel) when it is 1599 booted 1600 1601- CFG_BAUDRATE_TABLE: 1602 List of legal baudrate settings for this board. 1603 1604- CFG_CONSOLE_INFO_QUIET 1605 Suppress display of console information at boot. 1606 1607- CFG_CONSOLE_IS_IN_ENV 1608 If the board specific function 1609 extern int overwrite_console (void); 1610 returns 1, the stdin, stderr and stdout are switched to the 1611 serial port, else the settings in the environment are used. 1612 1613- CFG_CONSOLE_OVERWRITE_ROUTINE 1614 Enable the call to overwrite_console(). 1615 1616- CFG_CONSOLE_ENV_OVERWRITE 1617 Enable overwrite of previous console environment settings. 1618 1619- CFG_MEMTEST_START, CFG_MEMTEST_END: 1620 Begin and End addresses of the area used by the 1621 simple memory test. 1622 1623- CFG_ALT_MEMTEST: 1624 Enable an alternate, more extensive memory test. 1625 1626- CFG_MEMTEST_SCRATCH: 1627 Scratch address used by the alternate memory test 1628 You only need to set this if address zero isn't writeable 1629 1630- CFG_TFTP_LOADADDR: 1631 Default load address for network file downloads 1632 1633- CFG_LOADS_BAUD_CHANGE: 1634 Enable temporary baudrate change while serial download 1635 1636- CFG_SDRAM_BASE: 1637 Physical start address of SDRAM. _Must_ be 0 here. 1638 1639- CFG_MBIO_BASE: 1640 Physical start address of Motherboard I/O (if using a 1641 Cogent motherboard) 1642 1643- CFG_FLASH_BASE: 1644 Physical start address of Flash memory. 1645 1646- CFG_MONITOR_BASE: 1647 Physical start address of boot monitor code (set by 1648 make config files to be same as the text base address 1649 (TEXT_BASE) used when linking) - same as 1650 CFG_FLASH_BASE when booting from flash. 1651 1652- CFG_MONITOR_LEN: 1653 Size of memory reserved for monitor code, used to 1654 determine _at_compile_time_ (!) if the environment is 1655 embedded within the U-Boot image, or in a separate 1656 flash sector. 1657 1658- CFG_MALLOC_LEN: 1659 Size of DRAM reserved for malloc() use. 1660 1661- CFG_BOOTMAPSZ: 1662 Maximum size of memory mapped by the startup code of 1663 the Linux kernel; all data that must be processed by 1664 the Linux kernel (bd_info, boot arguments, eventually 1665 initrd image) must be put below this limit. 1666 1667- CFG_MAX_FLASH_BANKS: 1668 Max number of Flash memory banks 1669 1670- CFG_MAX_FLASH_SECT: 1671 Max number of sectors on a Flash chip 1672 1673- CFG_FLASH_ERASE_TOUT: 1674 Timeout for Flash erase operations (in ms) 1675 1676- CFG_FLASH_WRITE_TOUT: 1677 Timeout for Flash write operations (in ms) 1678 1679- CFG_FLASH_LOCK_TOUT 1680 Timeout for Flash set sector lock bit operation (in ms) 1681 1682- CFG_FLASH_UNLOCK_TOUT 1683 Timeout for Flash clear lock bits operation (in ms) 1684 1685- CFG_FLASH_PROTECTION 1686 If defined, hardware flash sectors protection is used 1687 instead of U-Boot software protection. 1688 1689- CFG_DIRECT_FLASH_TFTP: 1690 1691 Enable TFTP transfers directly to flash memory; 1692 without this option such a download has to be 1693 performed in two steps: (1) download to RAM, and (2) 1694 copy from RAM to flash. 1695 1696 The two-step approach is usually more reliable, since 1697 you can check if the download worked before you erase 1698 the flash, but in some situations (when sytem RAM is 1699 too limited to allow for a tempory copy of the 1700 downloaded image) this option may be very useful. 1701 1702- CFG_FLASH_CFI: 1703 Define if the flash driver uses extra elements in the 1704 common flash structure for storing flash geometry. 1705 1706- CFG_FLASH_CFI_DRIVER 1707 This option also enables the building of the cfi_flash driver 1708 in the drivers directory 1709 1710- CFG_RX_ETH_BUFFER: 1711 Defines the number of ethernet receive buffers. On some 1712 ethernet controllers it is recommended to set this value 1713 to 8 or even higher (EEPRO100 or 405 EMAC), since all 1714 buffers can be full shortly after enabling the interface 1715 on high ethernet traffic. 1716 Defaults to 4 if not defined. 1717 1718The following definitions that deal with the placement and management 1719of environment data (variable area); in general, we support the 1720following configurations: 1721 1722- CFG_ENV_IS_IN_FLASH: 1723 1724 Define this if the environment is in flash memory. 1725 1726 a) The environment occupies one whole flash sector, which is 1727 "embedded" in the text segment with the U-Boot code. This 1728 happens usually with "bottom boot sector" or "top boot 1729 sector" type flash chips, which have several smaller 1730 sectors at the start or the end. For instance, such a 1731 layout can have sector sizes of 8, 2x4, 16, Nx32 kB. In 1732 such a case you would place the environment in one of the 1733 4 kB sectors - with U-Boot code before and after it. With 1734 "top boot sector" type flash chips, you would put the 1735 environment in one of the last sectors, leaving a gap 1736 between U-Boot and the environment. 1737 1738 - CFG_ENV_OFFSET: 1739 1740 Offset of environment data (variable area) to the 1741 beginning of flash memory; for instance, with bottom boot 1742 type flash chips the second sector can be used: the offset 1743 for this sector is given here. 1744 1745 CFG_ENV_OFFSET is used relative to CFG_FLASH_BASE. 1746 1747 - CFG_ENV_ADDR: 1748 1749 This is just another way to specify the start address of 1750 the flash sector containing the environment (instead of 1751 CFG_ENV_OFFSET). 1752 1753 - CFG_ENV_SECT_SIZE: 1754 1755 Size of the sector containing the environment. 1756 1757 1758 b) Sometimes flash chips have few, equal sized, BIG sectors. 1759 In such a case you don't want to spend a whole sector for 1760 the environment. 1761 1762 - CFG_ENV_SIZE: 1763 1764 If you use this in combination with CFG_ENV_IS_IN_FLASH 1765 and CFG_ENV_SECT_SIZE, you can specify to use only a part 1766 of this flash sector for the environment. This saves 1767 memory for the RAM copy of the environment. 1768 1769 It may also save flash memory if you decide to use this 1770 when your environment is "embedded" within U-Boot code, 1771 since then the remainder of the flash sector could be used 1772 for U-Boot code. It should be pointed out that this is 1773 STRONGLY DISCOURAGED from a robustness point of view: 1774 updating the environment in flash makes it always 1775 necessary to erase the WHOLE sector. If something goes 1776 wrong before the contents has been restored from a copy in 1777 RAM, your target system will be dead. 1778 1779 - CFG_ENV_ADDR_REDUND 1780 CFG_ENV_SIZE_REDUND 1781 1782 These settings describe a second storage area used to hold 1783 a redundand copy of the environment data, so that there is 1784 a valid backup copy in case there is a power failure during 1785 a "saveenv" operation. 1786 1787BE CAREFUL! Any changes to the flash layout, and some changes to the 1788source code will make it necessary to adapt <board>/u-boot.lds* 1789accordingly! 1790 1791 1792- CFG_ENV_IS_IN_NVRAM: 1793 1794 Define this if you have some non-volatile memory device 1795 (NVRAM, battery buffered SRAM) which you want to use for the 1796 environment. 1797 1798 - CFG_ENV_ADDR: 1799 - CFG_ENV_SIZE: 1800 1801 These two #defines are used to determin the memory area you 1802 want to use for environment. It is assumed that this memory 1803 can just be read and written to, without any special 1804 provision. 1805 1806BE CAREFUL! The first access to the environment happens quite early 1807in U-Boot initalization (when we try to get the setting of for the 1808console baudrate). You *MUST* have mappend your NVRAM area then, or 1809U-Boot will hang. 1810 1811Please note that even with NVRAM we still use a copy of the 1812environment in RAM: we could work on NVRAM directly, but we want to 1813keep settings there always unmodified except somebody uses "saveenv" 1814to save the current settings. 1815 1816 1817- CFG_ENV_IS_IN_EEPROM: 1818 1819 Use this if you have an EEPROM or similar serial access 1820 device and a driver for it. 1821 1822 - CFG_ENV_OFFSET: 1823 - CFG_ENV_SIZE: 1824 1825 These two #defines specify the offset and size of the 1826 environment area within the total memory of your EEPROM. 1827 1828 - CFG_I2C_EEPROM_ADDR: 1829 If defined, specified the chip address of the EEPROM device. 1830 The default address is zero. 1831 1832 - CFG_EEPROM_PAGE_WRITE_BITS: 1833 If defined, the number of bits used to address bytes in a 1834 single page in the EEPROM device. A 64 byte page, for example 1835 would require six bits. 1836 1837 - CFG_EEPROM_PAGE_WRITE_DELAY_MS: 1838 If defined, the number of milliseconds to delay between 1839 page writes. The default is zero milliseconds. 1840 1841 - CFG_I2C_EEPROM_ADDR_LEN: 1842 The length in bytes of the EEPROM memory array address. Note 1843 that this is NOT the chip address length! 1844 1845 - CFG_I2C_EEPROM_ADDR_OVERFLOW: 1846 EEPROM chips that implement "address overflow" are ones 1847 like Catalyst 24WC04/08/16 which has 9/10/11 bits of 1848 address and the extra bits end up in the "chip address" bit 1849 slots. This makes a 24WC08 (1Kbyte) chip look like four 256 1850 byte chips. 1851 1852 Note that we consider the length of the address field to 1853 still be one byte because the extra address bits are hidden 1854 in the chip address. 1855 1856 - CFG_EEPROM_SIZE: 1857 The size in bytes of the EEPROM device. 1858 1859 1860- CFG_ENV_IS_IN_DATAFLASH: 1861 1862 Define this if you have a DataFlash memory device which you 1863 want to use for the environment. 1864 1865 - CFG_ENV_OFFSET: 1866 - CFG_ENV_ADDR: 1867 - CFG_ENV_SIZE: 1868 1869 These three #defines specify the offset and size of the 1870 environment area within the total memory of your DataFlash placed 1871 at the specified address. 1872 1873- CFG_ENV_IS_IN_NAND: 1874 1875 Define this if you have a NAND device which you want to use 1876 for the environment. 1877 1878 - CFG_ENV_OFFSET: 1879 - CFG_ENV_SIZE: 1880 1881 These two #defines specify the offset and size of the environment 1882 area within the first NAND device. 1883 1884- CFG_SPI_INIT_OFFSET 1885 1886 Defines offset to the initial SPI buffer area in DPRAM. The 1887 area is used at an early stage (ROM part) if the environment 1888 is configured to reside in the SPI EEPROM: We need a 520 byte 1889 scratch DPRAM area. It is used between the two initialization 1890 calls (spi_init_f() and spi_init_r()). A value of 0xB00 seems 1891 to be a good choice since it makes it far enough from the 1892 start of the data area as well as from the stack pointer. 1893 1894Please note that the environment is read-only as long as the monitor 1895has been relocated to RAM and a RAM copy of the environment has been 1896created; also, when using EEPROM you will have to use getenv_r() 1897until then to read environment variables. 1898 1899The environment is protected by a CRC32 checksum. Before the monitor 1900is relocated into RAM, as a result of a bad CRC you will be working 1901with the compiled-in default environment - *silently*!!! [This is 1902necessary, because the first environment variable we need is the 1903"baudrate" setting for the console - if we have a bad CRC, we don't 1904have any device yet where we could complain.] 1905 1906Note: once the monitor has been relocated, then it will complain if 1907the default environment is used; a new CRC is computed as soon as you 1908use the "saveenv" command to store a valid environment. 1909 1910- CFG_FAULT_ECHO_LINK_DOWN: 1911 Echo the inverted Ethernet link state to the fault LED. 1912 1913 Note: If this option is active, then CFG_FAULT_MII_ADDR 1914 also needs to be defined. 1915 1916- CFG_FAULT_MII_ADDR: 1917 MII address of the PHY to check for the Ethernet link state. 1918 1919- CFG_64BIT_VSPRINTF: 1920 Makes vsprintf (and all *printf functions) support printing 1921 of 64bit values by using the L quantifier 1922 1923- CFG_64BIT_STRTOUL: 1924 Adds simple_strtoull that returns a 64bit value 1925 1926Low Level (hardware related) configuration options: 1927--------------------------------------------------- 1928 1929- CFG_CACHELINE_SIZE: 1930 Cache Line Size of the CPU. 1931 1932- CFG_DEFAULT_IMMR: 1933 Default address of the IMMR after system reset. 1934 1935 Needed on some 8260 systems (MPC8260ADS, PQ2FADS-ZU, 1936 and RPXsuper) to be able to adjust the position of 1937 the IMMR register after a reset. 1938 1939- Floppy Disk Support: 1940 CFG_FDC_DRIVE_NUMBER 1941 1942 the default drive number (default value 0) 1943 1944 CFG_ISA_IO_STRIDE 1945 1946 defines the spacing between fdc chipset registers 1947 (default value 1) 1948 1949 CFG_ISA_IO_OFFSET 1950 1951 defines the offset of register from address. It 1952 depends on which part of the data bus is connected to 1953 the fdc chipset. (default value 0) 1954 1955 If CFG_ISA_IO_STRIDE CFG_ISA_IO_OFFSET and 1956 CFG_FDC_DRIVE_NUMBER are undefined, they take their 1957 default value. 1958 1959 if CFG_FDC_HW_INIT is defined, then the function 1960 fdc_hw_init() is called at the beginning of the FDC 1961 setup. fdc_hw_init() must be provided by the board 1962 source code. It is used to make hardware dependant 1963 initializations. 1964 1965- CFG_IMMR: Physical address of the Internal Memory Mapped 1966 Register; DO NOT CHANGE! (11-4) 1967 [MPC8xx systems only] 1968 1969- CFG_INIT_RAM_ADDR: 1970 1971 Start address of memory area that can be used for 1972 initial data and stack; please note that this must be 1973 writable memory that is working WITHOUT special 1974 initialization, i. e. you CANNOT use normal RAM which 1975 will become available only after programming the 1976 memory controller and running certain initialization 1977 sequences. 1978 1979 U-Boot uses the following memory types: 1980 - MPC8xx and MPC8260: IMMR (internal memory of the CPU) 1981 - MPC824X: data cache 1982 - PPC4xx: data cache 1983 1984- CFG_GBL_DATA_OFFSET: 1985 1986 Offset of the initial data structure in the memory 1987 area defined by CFG_INIT_RAM_ADDR. Usually 1988 CFG_GBL_DATA_OFFSET is chosen such that the initial 1989 data is located at the end of the available space 1990 (sometimes written as (CFG_INIT_RAM_END - 1991 CFG_INIT_DATA_SIZE), and the initial stack is just 1992 below that area (growing from (CFG_INIT_RAM_ADDR + 1993 CFG_GBL_DATA_OFFSET) downward. 1994 1995 Note: 1996 On the MPC824X (or other systems that use the data 1997 cache for initial memory) the address chosen for 1998 CFG_INIT_RAM_ADDR is basically arbitrary - it must 1999 point to an otherwise UNUSED address space between 2000 the top of RAM and the start of the PCI space. 2001 2002- CFG_SIUMCR: SIU Module Configuration (11-6) 2003 2004- CFG_SYPCR: System Protection Control (11-9) 2005 2006- CFG_TBSCR: Time Base Status and Control (11-26) 2007 2008- CFG_PISCR: Periodic Interrupt Status and Control (11-31) 2009 2010- CFG_PLPRCR: PLL, Low-Power, and Reset Control Register (15-30) 2011 2012- CFG_SCCR: System Clock and reset Control Register (15-27) 2013 2014- CFG_OR_TIMING_SDRAM: 2015 SDRAM timing 2016 2017- CFG_MAMR_PTA: 2018 periodic timer for refresh 2019 2020- CFG_DER: Debug Event Register (37-47) 2021 2022- FLASH_BASE0_PRELIM, FLASH_BASE1_PRELIM, CFG_REMAP_OR_AM, 2023 CFG_PRELIM_OR_AM, CFG_OR_TIMING_FLASH, CFG_OR0_REMAP, 2024 CFG_OR0_PRELIM, CFG_BR0_PRELIM, CFG_OR1_REMAP, CFG_OR1_PRELIM, 2025 CFG_BR1_PRELIM: 2026 Memory Controller Definitions: BR0/1 and OR0/1 (FLASH) 2027 2028- SDRAM_BASE2_PRELIM, SDRAM_BASE3_PRELIM, SDRAM_MAX_SIZE, 2029 CFG_OR_TIMING_SDRAM, CFG_OR2_PRELIM, CFG_BR2_PRELIM, 2030 CFG_OR3_PRELIM, CFG_BR3_PRELIM: 2031 Memory Controller Definitions: BR2/3 and OR2/3 (SDRAM) 2032 2033- CFG_MAMR_PTA, CFG_MPTPR_2BK_4K, CFG_MPTPR_1BK_4K, CFG_MPTPR_2BK_8K, 2034 CFG_MPTPR_1BK_8K, CFG_MAMR_8COL, CFG_MAMR_9COL: 2035 Machine Mode Register and Memory Periodic Timer 2036 Prescaler definitions (SDRAM timing) 2037 2038- CFG_I2C_UCODE_PATCH, CFG_I2C_DPMEM_OFFSET [0x1FC0]: 2039 enable I2C microcode relocation patch (MPC8xx); 2040 define relocation offset in DPRAM [DSP2] 2041 2042- CFG_SPI_UCODE_PATCH, CFG_SPI_DPMEM_OFFSET [0x1FC0]: 2043 enable SPI microcode relocation patch (MPC8xx); 2044 define relocation offset in DPRAM [SCC4] 2045 2046- CFG_USE_OSCCLK: 2047 Use OSCM clock mode on MBX8xx board. Be careful, 2048 wrong setting might damage your board. Read 2049 doc/README.MBX before setting this variable! 2050 2051- CFG_CPM_POST_WORD_ADDR: (MPC8xx, MPC8260 only) 2052 Offset of the bootmode word in DPRAM used by post 2053 (Power On Self Tests). This definition overrides 2054 #define'd default value in commproc.h resp. 2055 cpm_8260.h. 2056 2057- CFG_PCI_SLV_MEM_LOCAL, CFG_PCI_SLV_MEM_BUS, CFG_PICMR0_MASK_ATTRIB, 2058 CFG_PCI_MSTR0_LOCAL, CFG_PCIMSK0_MASK, CFG_PCI_MSTR1_LOCAL, 2059 CFG_PCIMSK1_MASK, CFG_PCI_MSTR_MEM_LOCAL, CFG_PCI_MSTR_MEM_BUS, 2060 CFG_CPU_PCI_MEM_START, CFG_PCI_MSTR_MEM_SIZE, CFG_POCMR0_MASK_ATTRIB, 2061 CFG_PCI_MSTR_MEMIO_LOCAL, CFG_PCI_MSTR_MEMIO_BUS, CPU_PCI_MEMIO_START, 2062 CFG_PCI_MSTR_MEMIO_SIZE, CFG_POCMR1_MASK_ATTRIB, CFG_PCI_MSTR_IO_LOCAL, 2063 CFG_PCI_MSTR_IO_BUS, CFG_CPU_PCI_IO_START, CFG_PCI_MSTR_IO_SIZE, 2064 CFG_POCMR2_MASK_ATTRIB: (MPC826x only) 2065 Overrides the default PCI memory map in cpu/mpc8260/pci.c if set. 2066 2067- CONFIG_ETHER_ON_FEC[12] 2068 Define to enable FEC[12] on a 8xx series processor. 2069 2070- CONFIG_FEC[12]_PHY 2071 Define to the hardcoded PHY address which corresponds 2072 to the given FEC; i. e. 2073 #define CONFIG_FEC1_PHY 4 2074 means that the PHY with address 4 is connected to FEC1 2075 2076 When set to -1, means to probe for first available. 2077 2078- CONFIG_FEC[12]_PHY_NORXERR 2079 The PHY does not have a RXERR line (RMII only). 2080 (so program the FEC to ignore it). 2081 2082- CONFIG_RMII 2083 Enable RMII mode for all FECs. 2084 Note that this is a global option, we can't 2085 have one FEC in standard MII mode and another in RMII mode. 2086 2087- CONFIG_CRC32_VERIFY 2088 Add a verify option to the crc32 command. 2089 The syntax is: 2090 2091 => crc32 -v <address> <count> <crc32> 2092 2093 Where address/count indicate a memory area 2094 and crc32 is the correct crc32 which the 2095 area should have. 2096 2097- CONFIG_LOOPW 2098 Add the "loopw" memory command. This only takes effect if 2099 the memory commands are activated globally (CFG_CMD_MEM). 2100 2101Building the Software: 2102====================== 2103 2104Building U-Boot has been tested in native PPC environments (on a 2105PowerBook G3 running LinuxPPC 2000) and in cross environments 2106(running RedHat 6.x and 7.x Linux on x86, Solaris 2.6 on a SPARC, and 2107NetBSD 1.5 on x86). 2108 2109If you are not using a native PPC environment, it is assumed that you 2110have the GNU cross compiling tools available in your path and named 2111with a prefix of "powerpc-linux-". If this is not the case, (e.g. if 2112you are using Monta Vista's Hard Hat Linux CDK 1.2) you must change 2113the definition of CROSS_COMPILE in Makefile. For HHL on a 4xx CPU, 2114change it to: 2115 2116 CROSS_COMPILE = ppc_4xx- 2117 2118 2119U-Boot is intended to be simple to build. After installing the 2120sources you must configure U-Boot for one specific board type. This 2121is done by typing: 2122 2123 make NAME_config 2124 2125where "NAME_config" is the name of one of the existing 2126configurations; the following names are supported: 2127 2128 ADCIOP_config FPS860L_config omap730p2_config 2129 ADS860_config GEN860T_config pcu_e_config 2130 AR405_config GENIETV_config PIP405_config 2131 at91rm9200dk_config GTH_config QS823_config 2132 CANBT_config hermes_config QS850_config 2133 cmi_mpc5xx_config hymod_config QS860T_config 2134 cogent_common_config IP860_config RPXlite_config 2135 cogent_mpc8260_config IVML24_config RPXlite_DW_config 2136 cogent_mpc8xx_config IVMS8_config RPXsuper_config 2137 CPCI405_config JSE_config rsdproto_config 2138 CPCIISER4_config LANTEC_config Sandpoint8240_config 2139 csb272_config lwmon_config sbc8260_config 2140 CU824_config MBX860T_config sbc8560_33_config 2141 DUET_ADS_config MBX_config sbc8560_66_config 2142 EBONY_config MPC8260ADS_config SM850_config 2143 ELPT860_config MPC8540ADS_config SPD823TS_config 2144 ESTEEM192E_config MPC8560ADS_config stxgp3_config 2145 ETX094_config NETVIA_config SXNI855T_config 2146 FADS823_config omap1510inn_config TQM823L_config 2147 FADS850SAR_config omap1610h2_config TQM850L_config 2148 FADS860T_config omap1610inn_config TQM855L_config 2149 FPS850L_config omap5912osk_config TQM860L_config 2150 WALNUT405_config 2151 ZPC1900_config 2152 2153Note: for some board special configuration names may exist; check if 2154 additional information is available from the board vendor; for 2155 instance, the TQM823L systems are available without (standard) 2156 or with LCD support. You can select such additional "features" 2157 when chosing the configuration, i. e. 2158 2159 make TQM823L_config 2160 - will configure for a plain TQM823L, i. e. no LCD support 2161 2162 make TQM823L_LCD_config 2163 - will configure for a TQM823L with U-Boot console on LCD 2164 2165 etc. 2166 2167 2168Finally, type "make all", and you should get some working U-Boot 2169images ready for download to / installation on your system: 2170 2171- "u-boot.bin" is a raw binary image 2172- "u-boot" is an image in ELF binary format 2173- "u-boot.srec" is in Motorola S-Record format 2174 2175 2176Please be aware that the Makefiles assume you are using GNU make, so 2177for instance on NetBSD you might need to use "gmake" instead of 2178native "make". 2179 2180 2181If the system board that you have is not listed, then you will need 2182to port U-Boot to your hardware platform. To do this, follow these 2183steps: 2184 21851. Add a new configuration option for your board to the toplevel 2186 "Makefile" and to the "MAKEALL" script, using the existing 2187 entries as examples. Note that here and at many other places 2188 boards and other names are listed in alphabetical sort order. Please 2189 keep this order. 21902. Create a new directory to hold your board specific code. Add any 2191 files you need. In your board directory, you will need at least 2192 the "Makefile", a "<board>.c", "flash.c" and "u-boot.lds". 21933. Create a new configuration file "include/configs/<board>.h" for 2194 your board 21953. If you're porting U-Boot to a new CPU, then also create a new 2196 directory to hold your CPU specific code. Add any files you need. 21974. Run "make <board>_config" with your new name. 21985. Type "make", and you should get a working "u-boot.srec" file 2199 to be installed on your target system. 22006. Debug and solve any problems that might arise. 2201 [Of course, this last step is much harder than it sounds.] 2202 2203 2204Testing of U-Boot Modifications, Ports to New Hardware, etc.: 2205============================================================== 2206 2207If you have modified U-Boot sources (for instance added a new board 2208or support for new devices, a new CPU, etc.) you are expected to 2209provide feedback to the other developers. The feedback normally takes 2210the form of a "patch", i. e. a context diff against a certain (latest 2211official or latest in CVS) version of U-Boot sources. 2212 2213But before you submit such a patch, please verify that your modifi- 2214cation did not break existing code. At least make sure that *ALL* of 2215the supported boards compile WITHOUT ANY compiler warnings. To do so, 2216just run the "MAKEALL" script, which will configure and build U-Boot 2217for ALL supported system. Be warned, this will take a while. You can 2218select which (cross) compiler to use by passing a `CROSS_COMPILE' 2219environment variable to the script, i. e. to use the cross tools from 2220MontaVista's Hard Hat Linux you can type 2221 2222 CROSS_COMPILE=ppc_8xx- MAKEALL 2223 2224or to build on a native PowerPC system you can type 2225 2226 CROSS_COMPILE=' ' MAKEALL 2227 2228See also "U-Boot Porting Guide" below. 2229 2230 2231Monitor Commands - Overview: 2232============================ 2233 2234go - start application at address 'addr' 2235run - run commands in an environment variable 2236bootm - boot application image from memory 2237bootp - boot image via network using BootP/TFTP protocol 2238tftpboot- boot image via network using TFTP protocol 2239 and env variables "ipaddr" and "serverip" 2240 (and eventually "gatewayip") 2241rarpboot- boot image via network using RARP/TFTP protocol 2242diskboot- boot from IDE devicebootd - boot default, i.e., run 'bootcmd' 2243loads - load S-Record file over serial line 2244loadb - load binary file over serial line (kermit mode) 2245md - memory display 2246mm - memory modify (auto-incrementing) 2247nm - memory modify (constant address) 2248mw - memory write (fill) 2249cp - memory copy 2250cmp - memory compare 2251crc32 - checksum calculation 2252imd - i2c memory display 2253imm - i2c memory modify (auto-incrementing) 2254inm - i2c memory modify (constant address) 2255imw - i2c memory write (fill) 2256icrc32 - i2c checksum calculation 2257iprobe - probe to discover valid I2C chip addresses 2258iloop - infinite loop on address range 2259isdram - print SDRAM configuration information 2260sspi - SPI utility commands 2261base - print or set address offset 2262printenv- print environment variables 2263setenv - set environment variables 2264saveenv - save environment variables to persistent storage 2265protect - enable or disable FLASH write protection 2266erase - erase FLASH memory 2267flinfo - print FLASH memory information 2268bdinfo - print Board Info structure 2269iminfo - print header information for application image 2270coninfo - print console devices and informations 2271ide - IDE sub-system 2272loop - infinite loop on address range 2273loopw - infinite write loop on address range 2274mtest - simple RAM test 2275icache - enable or disable instruction cache 2276dcache - enable or disable data cache 2277reset - Perform RESET of the CPU 2278echo - echo args to console 2279version - print monitor version 2280help - print online help 2281? - alias for 'help' 2282 2283 2284Monitor Commands - Detailed Description: 2285======================================== 2286 2287TODO. 2288 2289For now: just type "help <command>". 2290 2291 2292Environment Variables: 2293====================== 2294 2295U-Boot supports user configuration using Environment Variables which 2296can be made persistent by saving to Flash memory. 2297 2298Environment Variables are set using "setenv", printed using 2299"printenv", and saved to Flash using "saveenv". Using "setenv" 2300without a value can be used to delete a variable from the 2301environment. As long as you don't save the environment you are 2302working with an in-memory copy. In case the Flash area containing the 2303environment is erased by accident, a default environment is provided. 2304 2305Some configuration options can be set using Environment Variables: 2306 2307 baudrate - see CONFIG_BAUDRATE 2308 2309 bootdelay - see CONFIG_BOOTDELAY 2310 2311 bootcmd - see CONFIG_BOOTCOMMAND 2312 2313 bootargs - Boot arguments when booting an RTOS image 2314 2315 bootfile - Name of the image to load with TFTP 2316 2317 autoload - if set to "no" (any string beginning with 'n'), 2318 "bootp" will just load perform a lookup of the 2319 configuration from the BOOTP server, but not try to 2320 load any image using TFTP 2321 2322 autostart - if set to "yes", an image loaded using the "bootp", 2323 "rarpboot", "tftpboot" or "diskboot" commands will 2324 be automatically started (by internally calling 2325 "bootm") 2326 2327 If set to "no", a standalone image passed to the 2328 "bootm" command will be copied to the load address 2329 (and eventually uncompressed), but NOT be started. 2330 This can be used to load and uncompress arbitrary 2331 data. 2332 2333 i2cfast - (PPC405GP|PPC405EP only) 2334 if set to 'y' configures Linux I2C driver for fast 2335 mode (400kHZ). This environment variable is used in 2336 initialization code. So, for changes to be effective 2337 it must be saved and board must be reset. 2338 2339 initrd_high - restrict positioning of initrd images: 2340 If this variable is not set, initrd images will be 2341 copied to the highest possible address in RAM; this 2342 is usually what you want since it allows for 2343 maximum initrd size. If for some reason you want to 2344 make sure that the initrd image is loaded below the 2345 CFG_BOOTMAPSZ limit, you can set this environment 2346 variable to a value of "no" or "off" or "0". 2347 Alternatively, you can set it to a maximum upper 2348 address to use (U-Boot will still check that it 2349 does not overwrite the U-Boot stack and data). 2350 2351 For instance, when you have a system with 16 MB 2352 RAM, and want to reserve 4 MB from use by Linux, 2353 you can do this by adding "mem=12M" to the value of 2354 the "bootargs" variable. However, now you must make 2355 sure that the initrd image is placed in the first 2356 12 MB as well - this can be done with 2357 2358 setenv initrd_high 00c00000 2359 2360 If you set initrd_high to 0xFFFFFFFF, this is an 2361 indication to U-Boot that all addresses are legal 2362 for the Linux kernel, including addresses in flash 2363 memory. In this case U-Boot will NOT COPY the 2364 ramdisk at all. This may be useful to reduce the 2365 boot time on your system, but requires that this 2366 feature is supported by your Linux kernel. 2367 2368 ipaddr - IP address; needed for tftpboot command 2369 2370 loadaddr - Default load address for commands like "bootp", 2371 "rarpboot", "tftpboot", "loadb" or "diskboot" 2372 2373 loads_echo - see CONFIG_LOADS_ECHO 2374 2375 serverip - TFTP server IP address; needed for tftpboot command 2376 2377 bootretry - see CONFIG_BOOT_RETRY_TIME 2378 2379 bootdelaykey - see CONFIG_AUTOBOOT_DELAY_STR 2380 2381 bootstopkey - see CONFIG_AUTOBOOT_STOP_STR 2382 2383 ethprime - When CONFIG_NET_MULTI is enabled controls which 2384 interface is used first. 2385 2386 ethact - When CONFIG_NET_MULTI is enabled controls which 2387 interface is currently active. For example you 2388 can do the following 2389 2390 => setenv ethact FEC ETHERNET 2391 => ping 192.168.0.1 # traffic sent on FEC ETHERNET 2392 => setenv ethact SCC ETHERNET 2393 => ping 10.0.0.1 # traffic sent on SCC ETHERNET 2394 2395 netretry - When set to "no" each network operation will 2396 either succeed or fail without retrying. 2397 When set to "once" the network operation will 2398 fail when all the available network interfaces 2399 are tried once without success. 2400 Useful on scripts which control the retry operation 2401 themselves. 2402 2403 vlan - When set to a value < 4095 the traffic over 2404 ethernet is encapsulated/received over 802.1q 2405 VLAN tagged frames. 2406 2407The following environment variables may be used and automatically 2408updated by the network boot commands ("bootp" and "rarpboot"), 2409depending the information provided by your boot server: 2410 2411 bootfile - see above 2412 dnsip - IP address of your Domain Name Server 2413 dnsip2 - IP address of your secondary Domain Name Server 2414 gatewayip - IP address of the Gateway (Router) to use 2415 hostname - Target hostname 2416 ipaddr - see above 2417 netmask - Subnet Mask 2418 rootpath - Pathname of the root filesystem on the NFS server 2419 serverip - see above 2420 2421 2422There are two special Environment Variables: 2423 2424 serial# - contains hardware identification information such 2425 as type string and/or serial number 2426 ethaddr - Ethernet address 2427 2428These variables can be set only once (usually during manufacturing of 2429the board). U-Boot refuses to delete or overwrite these variables 2430once they have been set once. 2431 2432 2433Further special Environment Variables: 2434 2435 ver - Contains the U-Boot version string as printed 2436 with the "version" command. This variable is 2437 readonly (see CONFIG_VERSION_VARIABLE). 2438 2439 2440Please note that changes to some configuration parameters may take 2441only effect after the next boot (yes, that's just like Windoze :-). 2442 2443 2444Command Line Parsing: 2445===================== 2446 2447There are two different command line parsers available with U-Boot: 2448the old "simple" one, and the much more powerful "hush" shell: 2449 2450Old, simple command line parser: 2451-------------------------------- 2452 2453- supports environment variables (through setenv / saveenv commands) 2454- several commands on one line, separated by ';' 2455- variable substitution using "... $(name) ..." syntax 2456- special characters ('$', ';') can be escaped by prefixing with '\', 2457 for example: 2458 setenv bootcmd bootm \$(address) 2459- You can also escape text by enclosing in single apostrophes, for example: 2460 setenv addip 'setenv bootargs $bootargs ip=$ipaddr:$serverip:$gatewayip:$netmask:$hostname::off' 2461 2462Hush shell: 2463----------- 2464 2465- similar to Bourne shell, with control structures like 2466 if...then...else...fi, for...do...done; while...do...done, 2467 until...do...done, ... 2468- supports environment ("global") variables (through setenv / saveenv 2469 commands) and local shell variables (through standard shell syntax 2470 "name=value"); only environment variables can be used with "run" 2471 command 2472 2473General rules: 2474-------------- 2475 2476(1) If a command line (or an environment variable executed by a "run" 2477 command) contains several commands separated by semicolon, and 2478 one of these commands fails, then the remaining commands will be 2479 executed anyway. 2480 2481(2) If you execute several variables with one call to run (i. e. 2482 calling run with a list af variables as arguments), any failing 2483 command will cause "run" to terminate, i. e. the remaining 2484 variables are not executed. 2485 2486Note for Redundant Ethernet Interfaces: 2487======================================= 2488 2489Some boards come with redundant ethernet interfaces; U-Boot supports 2490such configurations and is capable of automatic selection of a 2491"working" interface when needed. MAC assignment works as follows: 2492 2493Network interfaces are numbered eth0, eth1, eth2, ... Corresponding 2494MAC addresses can be stored in the environment as "ethaddr" (=>eth0), 2495"eth1addr" (=>eth1), "eth2addr", ... 2496 2497If the network interface stores some valid MAC address (for instance 2498in SROM), this is used as default address if there is NO correspon- 2499ding setting in the environment; if the corresponding environment 2500variable is set, this overrides the settings in the card; that means: 2501 2502o If the SROM has a valid MAC address, and there is no address in the 2503 environment, the SROM's address is used. 2504 2505o If there is no valid address in the SROM, and a definition in the 2506 environment exists, then the value from the environment variable is 2507 used. 2508 2509o If both the SROM and the environment contain a MAC address, and 2510 both addresses are the same, this MAC address is used. 2511 2512o If both the SROM and the environment contain a MAC address, and the 2513 addresses differ, the value from the environment is used and a 2514 warning is printed. 2515 2516o If neither SROM nor the environment contain a MAC address, an error 2517 is raised. 2518 2519 2520Image Formats: 2521============== 2522 2523The "boot" commands of this monitor operate on "image" files which 2524can be basicly anything, preceeded by a special header; see the 2525definitions in include/image.h for details; basicly, the header 2526defines the following image properties: 2527 2528* Target Operating System (Provisions for OpenBSD, NetBSD, FreeBSD, 2529 4.4BSD, Linux, SVR4, Esix, Solaris, Irix, SCO, Dell, NCR, VxWorks, 2530 LynxOS, pSOS, QNX, RTEMS, ARTOS; 2531 Currently supported: Linux, NetBSD, VxWorks, QNX, RTEMS, ARTOS, LynxOS). 2532* Target CPU Architecture (Provisions for Alpha, ARM, Intel x86, 2533 IA64, MIPS, NIOS, PowerPC, IBM S390, SuperH, Sparc, Sparc 64 Bit; 2534 Currently supported: ARM, Intel x86, MIPS, NIOS, PowerPC). 2535* Compression Type (uncompressed, gzip, bzip2) 2536* Load Address 2537* Entry Point 2538* Image Name 2539* Image Timestamp 2540 2541The header is marked by a special Magic Number, and both the header 2542and the data portions of the image are secured against corruption by 2543CRC32 checksums. 2544 2545 2546Linux Support: 2547============== 2548 2549Although U-Boot should support any OS or standalone application 2550easily, the main focus has always been on Linux during the design of 2551U-Boot. 2552 2553U-Boot includes many features that so far have been part of some 2554special "boot loader" code within the Linux kernel. Also, any 2555"initrd" images to be used are no longer part of one big Linux image; 2556instead, kernel and "initrd" are separate images. This implementation 2557serves several purposes: 2558 2559- the same features can be used for other OS or standalone 2560 applications (for instance: using compressed images to reduce the 2561 Flash memory footprint) 2562 2563- it becomes much easier to port new Linux kernel versions because 2564 lots of low-level, hardware dependent stuff are done by U-Boot 2565 2566- the same Linux kernel image can now be used with different "initrd" 2567 images; of course this also means that different kernel images can 2568 be run with the same "initrd". This makes testing easier (you don't 2569 have to build a new "zImage.initrd" Linux image when you just 2570 change a file in your "initrd"). Also, a field-upgrade of the 2571 software is easier now. 2572 2573 2574Linux HOWTO: 2575============ 2576 2577Porting Linux to U-Boot based systems: 2578--------------------------------------- 2579 2580U-Boot cannot save you from doing all the necessary modifications to 2581configure the Linux device drivers for use with your target hardware 2582(no, we don't intend to provide a full virtual machine interface to 2583Linux :-). 2584 2585But now you can ignore ALL boot loader code (in arch/ppc/mbxboot). 2586 2587Just make sure your machine specific header file (for instance 2588include/asm-ppc/tqm8xx.h) includes the same definition of the Board 2589Information structure as we define in include/u-boot.h, and make 2590sure that your definition of IMAP_ADDR uses the same value as your 2591U-Boot configuration in CFG_IMMR. 2592 2593 2594Configuring the Linux kernel: 2595----------------------------- 2596 2597No specific requirements for U-Boot. Make sure you have some root 2598device (initial ramdisk, NFS) for your target system. 2599 2600 2601Building a Linux Image: 2602----------------------- 2603 2604With U-Boot, "normal" build targets like "zImage" or "bzImage" are 2605not used. If you use recent kernel source, a new build target 2606"uImage" will exist which automatically builds an image usable by 2607U-Boot. Most older kernels also have support for a "pImage" target, 2608which was introduced for our predecessor project PPCBoot and uses a 2609100% compatible format. 2610 2611Example: 2612 2613 make TQM850L_config 2614 make oldconfig 2615 make dep 2616 make uImage 2617 2618The "uImage" build target uses a special tool (in 'tools/mkimage') to 2619encapsulate a compressed Linux kernel image with header information, 2620CRC32 checksum etc. for use with U-Boot. This is what we are doing: 2621 2622* build a standard "vmlinux" kernel image (in ELF binary format): 2623 2624* convert the kernel into a raw binary image: 2625 2626 ${CROSS_COMPILE}-objcopy -O binary \ 2627 -R .note -R .comment \ 2628 -S vmlinux linux.bin 2629 2630* compress the binary image: 2631 2632 gzip -9 linux.bin 2633 2634* package compressed binary image for U-Boot: 2635 2636 mkimage -A ppc -O linux -T kernel -C gzip \ 2637 -a 0 -e 0 -n "Linux Kernel Image" \ 2638 -d linux.bin.gz uImage 2639 2640 2641The "mkimage" tool can also be used to create ramdisk images for use 2642with U-Boot, either separated from the Linux kernel image, or 2643combined into one file. "mkimage" encapsulates the images with a 64 2644byte header containing information about target architecture, 2645operating system, image type, compression method, entry points, time 2646stamp, CRC32 checksums, etc. 2647 2648"mkimage" can be called in two ways: to verify existing images and 2649print the header information, or to build new images. 2650 2651In the first form (with "-l" option) mkimage lists the information 2652contained in the header of an existing U-Boot image; this includes 2653checksum verification: 2654 2655 tools/mkimage -l image 2656 -l ==> list image header information 2657 2658The second form (with "-d" option) is used to build a U-Boot image 2659from a "data file" which is used as image payload: 2660 2661 tools/mkimage -A arch -O os -T type -C comp -a addr -e ep \ 2662 -n name -d data_file image 2663 -A ==> set architecture to 'arch' 2664 -O ==> set operating system to 'os' 2665 -T ==> set image type to 'type' 2666 -C ==> set compression type 'comp' 2667 -a ==> set load address to 'addr' (hex) 2668 -e ==> set entry point to 'ep' (hex) 2669 -n ==> set image name to 'name' 2670 -d ==> use image data from 'datafile' 2671 2672Right now, all Linux kernels for PowerPC systems use the same load 2673address (0x00000000), but the entry point address depends on the 2674kernel version: 2675 2676- 2.2.x kernels have the entry point at 0x0000000C, 2677- 2.3.x and later kernels have the entry point at 0x00000000. 2678 2679So a typical call to build a U-Boot image would read: 2680 2681 -> tools/mkimage -n '2.4.4 kernel for TQM850L' \ 2682 > -A ppc -O linux -T kernel -C gzip -a 0 -e 0 \ 2683 > -d /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/ppc/coffboot/vmlinux.gz \ 2684 > examples/uImage.TQM850L 2685 Image Name: 2.4.4 kernel for TQM850L 2686 Created: Wed Jul 19 02:34:59 2000 2687 Image Type: PowerPC Linux Kernel Image (gzip compressed) 2688 Data Size: 335725 Bytes = 327.86 kB = 0.32 MB 2689 Load Address: 0x00000000 2690 Entry Point: 0x00000000 2691 2692To verify the contents of the image (or check for corruption): 2693 2694 -> tools/mkimage -l examples/uImage.TQM850L 2695 Image Name: 2.4.4 kernel for TQM850L 2696 Created: Wed Jul 19 02:34:59 2000 2697 Image Type: PowerPC Linux Kernel Image (gzip compressed) 2698 Data Size: 335725 Bytes = 327.86 kB = 0.32 MB 2699 Load Address: 0x00000000 2700 Entry Point: 0x00000000 2701 2702NOTE: for embedded systems where boot time is critical you can trade 2703speed for memory and install an UNCOMPRESSED image instead: this 2704needs more space in Flash, but boots much faster since it does not 2705need to be uncompressed: 2706 2707 -> gunzip /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/ppc/coffboot/vmlinux.gz 2708 -> tools/mkimage -n '2.4.4 kernel for TQM850L' \ 2709 > -A ppc -O linux -T kernel -C none -a 0 -e 0 \ 2710 > -d /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/ppc/coffboot/vmlinux \ 2711 > examples/uImage.TQM850L-uncompressed 2712 Image Name: 2.4.4 kernel for TQM850L 2713 Created: Wed Jul 19 02:34:59 2000 2714 Image Type: PowerPC Linux Kernel Image (uncompressed) 2715 Data Size: 792160 Bytes = 773.59 kB = 0.76 MB 2716 Load Address: 0x00000000 2717 Entry Point: 0x00000000 2718 2719 2720Similar you can build U-Boot images from a 'ramdisk.image.gz' file 2721when your kernel is intended to use an initial ramdisk: 2722 2723 -> tools/mkimage -n 'Simple Ramdisk Image' \ 2724 > -A ppc -O linux -T ramdisk -C gzip \ 2725 > -d /LinuxPPC/images/SIMPLE-ramdisk.image.gz examples/simple-initrd 2726 Image Name: Simple Ramdisk Image 2727 Created: Wed Jan 12 14:01:50 2000 2728 Image Type: PowerPC Linux RAMDisk Image (gzip compressed) 2729 Data Size: 566530 Bytes = 553.25 kB = 0.54 MB 2730 Load Address: 0x00000000 2731 Entry Point: 0x00000000 2732 2733 2734Installing a Linux Image: 2735------------------------- 2736 2737To downloading a U-Boot image over the serial (console) interface, 2738you must convert the image to S-Record format: 2739 2740 objcopy -I binary -O srec examples/image examples/image.srec 2741 2742The 'objcopy' does not understand the information in the U-Boot 2743image header, so the resulting S-Record file will be relative to 2744address 0x00000000. To load it to a given address, you need to 2745specify the target address as 'offset' parameter with the 'loads' 2746command. 2747 2748Example: install the image to address 0x40100000 (which on the 2749TQM8xxL is in the first Flash bank): 2750 2751 => erase 40100000 401FFFFF 2752 2753 .......... done 2754 Erased 8 sectors 2755 2756 => loads 40100000 2757 ## Ready for S-Record download ... 2758 ~>examples/image.srec 2759 1 2 3 4 5 6 7 8 9 10 11 12 13 ... 2760 ... 2761 15989 15990 15991 15992 2762 [file transfer complete] 2763 [connected] 2764 ## Start Addr = 0x00000000 2765 2766 2767You can check the success of the download using the 'iminfo' command; 2768this includes a checksum verification so you can be sure no data 2769corruption happened: 2770 2771 => imi 40100000 2772 2773 ## Checking Image at 40100000 ... 2774 Image Name: 2.2.13 for initrd on TQM850L 2775 Image Type: PowerPC Linux Kernel Image (gzip compressed) 2776 Data Size: 335725 Bytes = 327 kB = 0 MB 2777 Load Address: 00000000 2778 Entry Point: 0000000c 2779 Verifying Checksum ... OK 2780 2781 2782Boot Linux: 2783----------- 2784 2785The "bootm" command is used to boot an application that is stored in 2786memory (RAM or Flash). In case of a Linux kernel image, the contents 2787of the "bootargs" environment variable is passed to the kernel as 2788parameters. You can check and modify this variable using the 2789"printenv" and "setenv" commands: 2790 2791 2792 => printenv bootargs 2793 bootargs=root=/dev/ram 2794 2795 => setenv bootargs root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2 2796 2797 => printenv bootargs 2798 bootargs=root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2 2799 2800 => bootm 40020000 2801 ## Booting Linux kernel at 40020000 ... 2802 Image Name: 2.2.13 for NFS on TQM850L 2803 Image Type: PowerPC Linux Kernel Image (gzip compressed) 2804 Data Size: 381681 Bytes = 372 kB = 0 MB 2805 Load Address: 00000000 2806 Entry Point: 0000000c 2807 Verifying Checksum ... OK 2808 Uncompressing Kernel Image ... OK 2809 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 2810 Boot arguments: root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2 2811 time_init: decrementer frequency = 187500000/60 2812 Calibrating delay loop... 49.77 BogoMIPS 2813 Memory: 15208k available (700k kernel code, 444k data, 32k init) [c0000000,c1000000] 2814 ... 2815 2816If you want to boot a Linux kernel with initial ram disk, you pass 2817the memory addresses of both the kernel and the initrd image (PPBCOOT 2818format!) to the "bootm" command: 2819 2820 => imi 40100000 40200000 2821 2822 ## Checking Image at 40100000 ... 2823 Image Name: 2.2.13 for initrd on TQM850L 2824 Image Type: PowerPC Linux Kernel Image (gzip compressed) 2825 Data Size: 335725 Bytes = 327 kB = 0 MB 2826 Load Address: 00000000 2827 Entry Point: 0000000c 2828 Verifying Checksum ... OK 2829 2830 ## Checking Image at 40200000 ... 2831 Image Name: Simple Ramdisk Image 2832 Image Type: PowerPC Linux RAMDisk Image (gzip compressed) 2833 Data Size: 566530 Bytes = 553 kB = 0 MB 2834 Load Address: 00000000 2835 Entry Point: 00000000 2836 Verifying Checksum ... OK 2837 2838 => bootm 40100000 40200000 2839 ## Booting Linux kernel at 40100000 ... 2840 Image Name: 2.2.13 for initrd on TQM850L 2841 Image Type: PowerPC Linux Kernel Image (gzip compressed) 2842 Data Size: 335725 Bytes = 327 kB = 0 MB 2843 Load Address: 00000000 2844 Entry Point: 0000000c 2845 Verifying Checksum ... OK 2846 Uncompressing Kernel Image ... OK 2847 ## Loading RAMDisk Image at 40200000 ... 2848 Image Name: Simple Ramdisk Image 2849 Image Type: PowerPC Linux RAMDisk Image (gzip compressed) 2850 Data Size: 566530 Bytes = 553 kB = 0 MB 2851 Load Address: 00000000 2852 Entry Point: 00000000 2853 Verifying Checksum ... OK 2854 Loading Ramdisk ... OK 2855 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 2856 Boot arguments: root=/dev/ram 2857 time_init: decrementer frequency = 187500000/60 2858 Calibrating delay loop... 49.77 BogoMIPS 2859 ... 2860 RAMDISK: Compressed image found at block 0 2861 VFS: Mounted root (ext2 filesystem). 2862 2863 bash# 2864 2865More About U-Boot Image Types: 2866------------------------------ 2867 2868U-Boot supports the following image types: 2869 2870 "Standalone Programs" are directly runnable in the environment 2871 provided by U-Boot; it is expected that (if they behave 2872 well) you can continue to work in U-Boot after return from 2873 the Standalone Program. 2874 "OS Kernel Images" are usually images of some Embedded OS which 2875 will take over control completely. Usually these programs 2876 will install their own set of exception handlers, device 2877 drivers, set up the MMU, etc. - this means, that you cannot 2878 expect to re-enter U-Boot except by resetting the CPU. 2879 "RAMDisk Images" are more or less just data blocks, and their 2880 parameters (address, size) are passed to an OS kernel that is 2881 being started. 2882 "Multi-File Images" contain several images, typically an OS 2883 (Linux) kernel image and one or more data images like 2884 RAMDisks. This construct is useful for instance when you want 2885 to boot over the network using BOOTP etc., where the boot 2886 server provides just a single image file, but you want to get 2887 for instance an OS kernel and a RAMDisk image. 2888 2889 "Multi-File Images" start with a list of image sizes, each 2890 image size (in bytes) specified by an "uint32_t" in network 2891 byte order. This list is terminated by an "(uint32_t)0". 2892 Immediately after the terminating 0 follow the images, one by 2893 one, all aligned on "uint32_t" boundaries (size rounded up to 2894 a multiple of 4 bytes). 2895 2896 "Firmware Images" are binary images containing firmware (like 2897 U-Boot or FPGA images) which usually will be programmed to 2898 flash memory. 2899 2900 "Script files" are command sequences that will be executed by 2901 U-Boot's command interpreter; this feature is especially 2902 useful when you configure U-Boot to use a real shell (hush) 2903 as command interpreter. 2904 2905 2906Standalone HOWTO: 2907================= 2908 2909One of the features of U-Boot is that you can dynamically load and 2910run "standalone" applications, which can use some resources of 2911U-Boot like console I/O functions or interrupt services. 2912 2913Two simple examples are included with the sources: 2914 2915"Hello World" Demo: 2916------------------- 2917 2918'examples/hello_world.c' contains a small "Hello World" Demo 2919application; it is automatically compiled when you build U-Boot. 2920It's configured to run at address 0x00040004, so you can play with it 2921like that: 2922 2923 => loads 2924 ## Ready for S-Record download ... 2925 ~>examples/hello_world.srec 2926 1 2 3 4 5 6 7 8 9 10 11 ... 2927 [file transfer complete] 2928 [connected] 2929 ## Start Addr = 0x00040004 2930 2931 => go 40004 Hello World! This is a test. 2932 ## Starting application at 0x00040004 ... 2933 Hello World 2934 argc = 7 2935 argv[0] = "40004" 2936 argv[1] = "Hello" 2937 argv[2] = "World!" 2938 argv[3] = "This" 2939 argv[4] = "is" 2940 argv[5] = "a" 2941 argv[6] = "test." 2942 argv[7] = "<NULL>" 2943 Hit any key to exit ... 2944 2945 ## Application terminated, rc = 0x0 2946 2947Another example, which demonstrates how to register a CPM interrupt 2948handler with the U-Boot code, can be found in 'examples/timer.c'. 2949Here, a CPM timer is set up to generate an interrupt every second. 2950The interrupt service routine is trivial, just printing a '.' 2951character, but this is just a demo program. The application can be 2952controlled by the following keys: 2953 2954 ? - print current values og the CPM Timer registers 2955 b - enable interrupts and start timer 2956 e - stop timer and disable interrupts 2957 q - quit application 2958 2959 => loads 2960 ## Ready for S-Record download ... 2961 ~>examples/timer.srec 2962 1 2 3 4 5 6 7 8 9 10 11 ... 2963 [file transfer complete] 2964 [connected] 2965 ## Start Addr = 0x00040004 2966 2967 => go 40004 2968 ## Starting application at 0x00040004 ... 2969 TIMERS=0xfff00980 2970 Using timer 1 2971 tgcr @ 0xfff00980, tmr @ 0xfff00990, trr @ 0xfff00994, tcr @ 0xfff00998, tcn @ 0xfff0099c, ter @ 0xfff009b0 2972 2973Hit 'b': 2974 [q, b, e, ?] Set interval 1000000 us 2975 Enabling timer 2976Hit '?': 2977 [q, b, e, ?] ........ 2978 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0xef6, ter=0x0 2979Hit '?': 2980 [q, b, e, ?] . 2981 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x2ad4, ter=0x0 2982Hit '?': 2983 [q, b, e, ?] . 2984 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x1efc, ter=0x0 2985Hit '?': 2986 [q, b, e, ?] . 2987 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x169d, ter=0x0 2988Hit 'e': 2989 [q, b, e, ?] ...Stopping timer 2990Hit 'q': 2991 [q, b, e, ?] ## Application terminated, rc = 0x0 2992 2993 2994Minicom warning: 2995================ 2996 2997Over time, many people have reported problems when trying to use the 2998"minicom" terminal emulation program for serial download. I (wd) 2999consider minicom to be broken, and recommend not to use it. Under 3000Unix, I recommend to use C-Kermit for general purpose use (and 3001especially for kermit binary protocol download ("loadb" command), and 3002use "cu" for S-Record download ("loads" command). 3003 3004Nevertheless, if you absolutely want to use it try adding this 3005configuration to your "File transfer protocols" section: 3006 3007 Name Program Name U/D FullScr IO-Red. Multi 3008 X kermit /usr/bin/kermit -i -l %l -s Y U Y N N 3009 Y kermit /usr/bin/kermit -i -l %l -r N D Y N N 3010 3011 3012NetBSD Notes: 3013============= 3014 3015Starting at version 0.9.2, U-Boot supports NetBSD both as host 3016(build U-Boot) and target system (boots NetBSD/mpc8xx). 3017 3018Building requires a cross environment; it is known to work on 3019NetBSD/i386 with the cross-powerpc-netbsd-1.3 package (you will also 3020need gmake since the Makefiles are not compatible with BSD make). 3021Note that the cross-powerpc package does not install include files; 3022attempting to build U-Boot will fail because <machine/ansi.h> is 3023missing. This file has to be installed and patched manually: 3024 3025 # cd /usr/pkg/cross/powerpc-netbsd/include 3026 # mkdir powerpc 3027 # ln -s powerpc machine 3028 # cp /usr/src/sys/arch/powerpc/include/ansi.h powerpc/ansi.h 3029 # ${EDIT} powerpc/ansi.h ## must remove __va_list, _BSD_VA_LIST 3030 3031Native builds *don't* work due to incompatibilities between native 3032and U-Boot include files. 3033 3034Booting assumes that (the first part of) the image booted is a 3035stage-2 loader which in turn loads and then invokes the kernel 3036proper. Loader sources will eventually appear in the NetBSD source 3037tree (probably in sys/arc/mpc8xx/stand/u-boot_stage2/); in the 3038meantime, send mail to bruno@exet-ag.de and/or wd@denx.de for 3039details. 3040 3041 3042Implementation Internals: 3043========================= 3044 3045The following is not intended to be a complete description of every 3046implementation detail. However, it should help to understand the 3047inner workings of U-Boot and make it easier to port it to custom 3048hardware. 3049 3050 3051Initial Stack, Global Data: 3052--------------------------- 3053 3054The implementation of U-Boot is complicated by the fact that U-Boot 3055starts running out of ROM (flash memory), usually without access to 3056system RAM (because the memory controller is not initialized yet). 3057This means that we don't have writable Data or BSS segments, and BSS 3058is not initialized as zero. To be able to get a C environment working 3059at all, we have to allocate at least a minimal stack. Implementation 3060options for this are defined and restricted by the CPU used: Some CPU 3061models provide on-chip memory (like the IMMR area on MPC8xx and 3062MPC826x processors), on others (parts of) the data cache can be 3063locked as (mis-) used as memory, etc. 3064 3065 Chris Hallinan posted a good summary of these issues to the 3066 u-boot-users mailing list: 3067 3068 Subject: RE: [U-Boot-Users] RE: More On Memory Bank x (nothingness)? 3069 From: "Chris Hallinan" <clh@net1plus.com> 3070 Date: Mon, 10 Feb 2003 16:43:46 -0500 (22:43 MET) 3071 ... 3072 3073 Correct me if I'm wrong, folks, but the way I understand it 3074 is this: Using DCACHE as initial RAM for Stack, etc, does not 3075 require any physical RAM backing up the cache. The cleverness 3076 is that the cache is being used as a temporary supply of 3077 necessary storage before the SDRAM controller is setup. It's 3078 beyond the scope of this list to expain the details, but you 3079 can see how this works by studying the cache architecture and 3080 operation in the architecture and processor-specific manuals. 3081 3082 OCM is On Chip Memory, which I believe the 405GP has 4K. It 3083 is another option for the system designer to use as an 3084 initial stack/ram area prior to SDRAM being available. Either 3085 option should work for you. Using CS 4 should be fine if your 3086 board designers haven't used it for something that would 3087 cause you grief during the initial boot! It is frequently not 3088 used. 3089 3090 CFG_INIT_RAM_ADDR should be somewhere that won't interfere 3091 with your processor/board/system design. The default value 3092 you will find in any recent u-boot distribution in 3093 Walnut405.h should work for you. I'd set it to a value larger 3094 than your SDRAM module. If you have a 64MB SDRAM module, set 3095 it above 400_0000. Just make sure your board has no resources 3096 that are supposed to respond to that address! That code in 3097 start.S has been around a while and should work as is when 3098 you get the config right. 3099 3100 -Chris Hallinan 3101 DS4.COM, Inc. 3102 3103It is essential to remember this, since it has some impact on the C 3104code for the initialization procedures: 3105 3106* Initialized global data (data segment) is read-only. Do not attempt 3107 to write it. 3108 3109* Do not use any unitialized global data (or implicitely initialized 3110 as zero data - BSS segment) at all - this is undefined, initiali- 3111 zation is performed later (when relocating to RAM). 3112 3113* Stack space is very limited. Avoid big data buffers or things like 3114 that. 3115 3116Having only the stack as writable memory limits means we cannot use 3117normal global data to share information beween the code. But it 3118turned out that the implementation of U-Boot can be greatly 3119simplified by making a global data structure (gd_t) available to all 3120functions. We could pass a pointer to this data as argument to _all_ 3121functions, but this would bloat the code. Instead we use a feature of 3122the GCC compiler (Global Register Variables) to share the data: we 3123place a pointer (gd) to the global data into a register which we 3124reserve for this purpose. 3125 3126When choosing a register for such a purpose we are restricted by the 3127relevant (E)ABI specifications for the current architecture, and by 3128GCC's implementation. 3129 3130For PowerPC, the following registers have specific use: 3131 R1: stack pointer 3132 R2: TOC pointer 3133 R3-R4: parameter passing and return values 3134 R5-R10: parameter passing 3135 R13: small data area pointer 3136 R30: GOT pointer 3137 R31: frame pointer 3138 3139 (U-Boot also uses R14 as internal GOT pointer.) 3140 3141 ==> U-Boot will use R29 to hold a pointer to the global data 3142 3143 Note: on PPC, we could use a static initializer (since the 3144 address of the global data structure is known at compile time), 3145 but it turned out that reserving a register results in somewhat 3146 smaller code - although the code savings are not that big (on 3147 average for all boards 752 bytes for the whole U-Boot image, 3148 624 text + 127 data). 3149 3150On ARM, the following registers are used: 3151 3152 R0: function argument word/integer result 3153 R1-R3: function argument word 3154 R9: GOT pointer 3155 R10: stack limit (used only if stack checking if enabled) 3156 R11: argument (frame) pointer 3157 R12: temporary workspace 3158 R13: stack pointer 3159 R14: link register 3160 R15: program counter 3161 3162 ==> U-Boot will use R8 to hold a pointer to the global data 3163 3164 3165Memory Management: 3166------------------ 3167 3168U-Boot runs in system state and uses physical addresses, i.e. the 3169MMU is not used either for address mapping nor for memory protection. 3170 3171The available memory is mapped to fixed addresses using the memory 3172controller. In this process, a contiguous block is formed for each 3173memory type (Flash, SDRAM, SRAM), even when it consists of several 3174physical memory banks. 3175 3176U-Boot is installed in the first 128 kB of the first Flash bank (on 3177TQM8xxL modules this is the range 0x40000000 ... 0x4001FFFF). After 3178booting and sizing and initializing DRAM, the code relocates itself 3179to the upper end of DRAM. Immediately below the U-Boot code some 3180memory is reserved for use by malloc() [see CFG_MALLOC_LEN 3181configuration setting]. Below that, a structure with global Board 3182Info data is placed, followed by the stack (growing downward). 3183 3184Additionally, some exception handler code is copied to the low 8 kB 3185of DRAM (0x00000000 ... 0x00001FFF). 3186 3187So a typical memory configuration with 16 MB of DRAM could look like 3188this: 3189 3190 0x0000 0000 Exception Vector code 3191 : 3192 0x0000 1FFF 3193 0x0000 2000 Free for Application Use 3194 : 3195 : 3196 3197 : 3198 : 3199 0x00FB FF20 Monitor Stack (Growing downward) 3200 0x00FB FFAC Board Info Data and permanent copy of global data 3201 0x00FC 0000 Malloc Arena 3202 : 3203 0x00FD FFFF 3204 0x00FE 0000 RAM Copy of Monitor Code 3205 ... eventually: LCD or video framebuffer 3206 ... eventually: pRAM (Protected RAM - unchanged by reset) 3207 0x00FF FFFF [End of RAM] 3208 3209 3210System Initialization: 3211---------------------- 3212 3213In the reset configuration, U-Boot starts at the reset entry point 3214(on most PowerPC systens at address 0x00000100). Because of the reset 3215configuration for CS0# this is a mirror of the onboard Flash memory. 3216To be able to re-map memory U-Boot then jumps to its link address. 3217To be able to implement the initialization code in C, a (small!) 3218initial stack is set up in the internal Dual Ported RAM (in case CPUs 3219which provide such a feature like MPC8xx or MPC8260), or in a locked 3220part of the data cache. After that, U-Boot initializes the CPU core, 3221the caches and the SIU. 3222 3223Next, all (potentially) available memory banks are mapped using a 3224preliminary mapping. For example, we put them on 512 MB boundaries 3225(multiples of 0x20000000: SDRAM on 0x00000000 and 0x20000000, Flash 3226on 0x40000000 and 0x60000000, SRAM on 0x80000000). Then UPM A is 3227programmed for SDRAM access. Using the temporary configuration, a 3228simple memory test is run that determines the size of the SDRAM 3229banks. 3230 3231When there is more than one SDRAM bank, and the banks are of 3232different size, the largest is mapped first. For equal size, the first 3233bank (CS2#) is mapped first. The first mapping is always for address 32340x00000000, with any additional banks following immediately to create 3235contiguous memory starting from 0. 3236 3237Then, the monitor installs itself at the upper end of the SDRAM area 3238and allocates memory for use by malloc() and for the global Board 3239Info data; also, the exception vector code is copied to the low RAM 3240pages, and the final stack is set up. 3241 3242Only after this relocation will you have a "normal" C environment; 3243until that you are restricted in several ways, mostly because you are 3244running from ROM, and because the code will have to be relocated to a 3245new address in RAM. 3246 3247 3248U-Boot Porting Guide: 3249---------------------- 3250 3251[Based on messages by Jerry Van Baren in the U-Boot-Users mailing 3252list, October 2002] 3253 3254 3255int main (int argc, char *argv[]) 3256{ 3257 sighandler_t no_more_time; 3258 3259 signal (SIGALRM, no_more_time); 3260 alarm (PROJECT_DEADLINE - toSec (3 * WEEK)); 3261 3262 if (available_money > available_manpower) { 3263 pay consultant to port U-Boot; 3264 return 0; 3265 } 3266 3267 Download latest U-Boot source; 3268 3269 Subscribe to u-boot-users mailing list; 3270 3271 if (clueless) { 3272 email ("Hi, I am new to U-Boot, how do I get started?"); 3273 } 3274 3275 while (learning) { 3276 Read the README file in the top level directory; 3277 Read http://www.denx.de/twiki/bin/view/DULG/Manual ; 3278 Read the source, Luke; 3279 } 3280 3281 if (available_money > toLocalCurrency ($2500)) { 3282 Buy a BDI2000; 3283 } else { 3284 Add a lot of aggravation and time; 3285 } 3286 3287 Create your own board support subdirectory; 3288 3289 Create your own board config file; 3290 3291 while (!running) { 3292 do { 3293 Add / modify source code; 3294 } until (compiles); 3295 Debug; 3296 if (clueless) 3297 email ("Hi, I am having problems..."); 3298 } 3299 Send patch file to Wolfgang; 3300 3301 return 0; 3302} 3303 3304void no_more_time (int sig) 3305{ 3306 hire_a_guru(); 3307} 3308 3309 3310Coding Standards: 3311----------------- 3312 3313All contributions to U-Boot should conform to the Linux kernel 3314coding style; see the file "Documentation/CodingStyle" in your Linux 3315kernel source directory. 3316 3317Please note that U-Boot is implemented in C (and to some small parts 3318in Assembler); no C++ is used, so please do not use C++ style 3319comments (//) in your code. 3320 3321Please also stick to the following formatting rules: 3322- remove any trailing white space 3323- use TAB characters for indentation, not spaces 3324- make sure NOT to use DOS '\r\n' line feeds 3325- do not add more than 2 empty lines to source files 3326- do not add trailing empty lines to source files 3327 3328Submissions which do not conform to the standards may be returned 3329with a request to reformat the changes. 3330 3331 3332Submitting Patches: 3333------------------- 3334 3335Since the number of patches for U-Boot is growing, we need to 3336establish some rules. Submissions which do not conform to these rules 3337may be rejected, even when they contain important and valuable stuff. 3338 3339 3340When you send a patch, please include the following information with 3341it: 3342 3343* For bug fixes: a description of the bug and how your patch fixes 3344 this bug. Please try to include a way of demonstrating that the 3345 patch actually fixes something. 3346 3347* For new features: a description of the feature and your 3348 implementation. 3349 3350* A CHANGELOG entry as plaintext (separate from the patch) 3351 3352* For major contributions, your entry to the CREDITS file 3353 3354* When you add support for a new board, don't forget to add this 3355 board to the MAKEALL script, too. 3356 3357* If your patch adds new configuration options, don't forget to 3358 document these in the README file. 3359 3360* The patch itself. If you are accessing the CVS repository use "cvs 3361 update; cvs diff -puRN"; else, use "diff -purN OLD NEW". If your 3362 version of diff does not support these options, then get the latest 3363 version of GNU diff. 3364 3365 The current directory when running this command shall be the top 3366 level directory of the U-Boot source tree, or it's parent directory 3367 (i. e. please make sure that your patch includes sufficient 3368 directory information for the affected files). 3369 3370 We accept patches as plain text, MIME attachments or as uuencoded 3371 gzipped text. 3372 3373* If one logical set of modifications affects or creates several 3374 files, all these changes shall be submitted in a SINGLE patch file. 3375 3376* Changesets that contain different, unrelated modifications shall be 3377 submitted as SEPARATE patches, one patch per changeset. 3378 3379 3380Notes: 3381 3382* Before sending the patch, run the MAKEALL script on your patched 3383 source tree and make sure that no errors or warnings are reported 3384 for any of the boards. 3385 3386* Keep your modifications to the necessary minimum: A patch 3387 containing several unrelated changes or arbitrary reformats will be 3388 returned with a request to re-formatting / split it. 3389 3390* If you modify existing code, make sure that your new code does not 3391 add to the memory footprint of the code ;-) Small is beautiful! 3392 When adding new features, these should compile conditionally only 3393 (using #ifdef), and the resulting code with the new feature 3394 disabled must not need more memory than the old code without your 3395 modification. 3396