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 - imx Files specific to Motorola MC9328 i.MX CPUs 129 - s3c24x0 Files specific to Samsung S3C24X0 CPUs 130 - arm925t Files specific to ARM 925 CPUs 131 - arm926ejs Files specific to ARM 926 CPUs 132 - at91rm9200 Files specific to Atmel AT91RM9200 CPUs 133 - i386 Files specific to i386 CPUs 134 - ixp Files specific to Intel XScale IXP CPUs 135 - mcf52x2 Files specific to Motorola ColdFire MCF52x2 CPUs 136 - mips Files specific to MIPS CPUs 137 - mpc5xx Files specific to Motorola MPC5xx CPUs 138 - mpc5xxx Files specific to Motorola MPC5xxx CPUs 139 - mpc8xx Files specific to Motorola MPC8xx CPUs 140 - mpc824x Files specific to Motorola MPC824x CPUs 141 - mpc8260 Files specific to Motorola MPC8260 CPUs 142 - mpc85xx Files specific to Motorola MPC85xx CPUs 143 - nios Files specific to Altera NIOS CPUs 144 - ppc4xx Files specific to IBM PowerPC 4xx CPUs 145 - pxa Files specific to Intel XScale PXA CPUs 146 - s3c44b0 Files specific to Samsung S3C44B0 CPUs 147 - sa1100 Files specific to Intel StrongARM SA1100 CPUs 148- disk Code for disk drive partition handling 149- doc Documentation (don't expect too much) 150- drivers Commonly used device drivers 151- dtt Digital Thermometer and Thermostat drivers 152- examples Example code for standalone applications, etc. 153- include Header Files 154- lib_arm Files generic to ARM architecture 155- lib_generic Files generic to all architectures 156- lib_i386 Files generic to i386 architecture 157- lib_m68k Files generic to m68k architecture 158- lib_mips Files generic to MIPS architecture 159- lib_nios Files generic to NIOS architecture 160- lib_ppc Files generic to PowerPC architecture 161- net Networking code 162- post Power On Self Test 163- rtc Real Time Clock drivers 164- tools Tools to build S-Record or U-Boot images, etc. 165 166Software Configuration: 167======================= 168 169Configuration is usually done using C preprocessor defines; the 170rationale behind that is to avoid dead code whenever possible. 171 172There are two classes of configuration variables: 173 174* Configuration _OPTIONS_: 175 These are selectable by the user and have names beginning with 176 "CONFIG_". 177 178* Configuration _SETTINGS_: 179 These depend on the hardware etc. and should not be meddled with if 180 you don't know what you're doing; they have names beginning with 181 "CFG_". 182 183Later we will add a configuration tool - probably similar to or even 184identical to what's used for the Linux kernel. Right now, we have to 185do the configuration by hand, which means creating some symbolic 186links and editing some configuration files. We use the TQM8xxL boards 187as an example here. 188 189 190Selection of Processor Architecture and Board Type: 191--------------------------------------------------- 192 193For all supported boards there are ready-to-use default 194configurations available; just type "make <board_name>_config". 195 196Example: For a TQM823L module type: 197 198 cd u-boot 199 make TQM823L_config 200 201For the Cogent platform, you need to specify the cpu type as well; 202e.g. "make cogent_mpc8xx_config". And also configure the cogent 203directory according to the instructions in cogent/README. 204 205 206Configuration Options: 207---------------------- 208 209Configuration depends on the combination of board and CPU type; all 210such information is kept in a configuration file 211"include/configs/<board_name>.h". 212 213Example: For a TQM823L module, all configuration settings are in 214"include/configs/TQM823L.h". 215 216 217Many of the options are named exactly as the corresponding Linux 218kernel configuration options. The intention is to make it easier to 219build a config tool - later. 220 221 222The following options need to be configured: 223 224- CPU Type: Define exactly one of 225 226 PowerPC based CPUs: 227 ------------------- 228 CONFIG_MPC823, CONFIG_MPC850, CONFIG_MPC855, CONFIG_MPC860 229 or CONFIG_MPC5xx 230 or CONFIG_MPC824X, CONFIG_MPC8260 231 or CONFIG_MPC85xx 232 or CONFIG_IOP480 233 or CONFIG_405GP 234 or CONFIG_405EP 235 or CONFIG_440 236 or CONFIG_MPC74xx 237 or CONFIG_750FX 238 239 ARM based CPUs: 240 --------------- 241 CONFIG_SA1110 242 CONFIG_ARM7 243 CONFIG_PXA250 244 245 MicroBlaze based CPUs: 246 ---------------------- 247 CONFIG_MICROBLAZE 248 249 250- Board Type: Define exactly one of 251 252 PowerPC based boards: 253 --------------------- 254 255 CONFIG_ADCIOP CONFIG_GEN860T CONFIG_PCI405 256 CONFIG_ADS860 CONFIG_GENIETV CONFIG_PCIPPC2 257 CONFIG_AMX860 CONFIG_GTH CONFIG_PCIPPC6 258 CONFIG_AR405 CONFIG_gw8260 CONFIG_pcu_e 259 CONFIG_BAB7xx CONFIG_hermes CONFIG_PIP405 260 CONFIG_c2mon CONFIG_hymod CONFIG_PM826 261 CONFIG_CANBT CONFIG_IAD210 CONFIG_ppmc8260 262 CONFIG_CCM CONFIG_ICU862 CONFIG_QS823 263 CONFIG_CMI CONFIG_IP860 CONFIG_QS850 264 CONFIG_cogent_mpc8260 CONFIG_IPHASE4539 CONFIG_QS860T 265 CONFIG_cogent_mpc8xx CONFIG_IVML24 CONFIG_RBC823 266 CONFIG_CPCI405 CONFIG_IVML24_128 CONFIG_RPXClassic 267 CONFIG_CPCI4052 CONFIG_IVML24_256 CONFIG_RPXlite 268 CONFIG_CPCIISER4 CONFIG_IVMS8 CONFIG_RPXsuper 269 CONFIG_CPU86 CONFIG_IVMS8_128 CONFIG_rsdproto 270 CONFIG_CRAYL1 CONFIG_IVMS8_256 CONFIG_sacsng 271 CONFIG_CSB272 CONFIG_JSE CONFIG_Sandpoint8240 272 CONFIG_CU824 CONFIG_LANTEC CONFIG_Sandpoint8245 273 CONFIG_DASA_SIM CONFIG_lwmon CONFIG_sbc8260 274 CONFIG_DB64360 CONFIG_MBX CONFIG_sbc8560 275 CONFIG_DB64460 CONFIG_MBX860T CONFIG_SM850 276 CONFIG_DU405 CONFIG_MHPC CONFIG_SPD823TS 277 CONFIG_DUET_ADS CONFIG_MIP405 CONFIG_STXGP3 278 CONFIG_EBONY CONFIG_MOUSSE CONFIG_SXNI855T 279 CONFIG_ELPPC CONFIG_MPC8260ADS CONFIG_TQM823L 280 CONFIG_ELPT860 CONFIG_MPC8540ADS CONFIG_TQM8260 281 CONFIG_ep8260 CONFIG_MPC8560ADS CONFIG_TQM850L 282 CONFIG_ERIC CONFIG_MUSENKI CONFIG_TQM855L 283 CONFIG_ESTEEM192E CONFIG_MVS1 CONFIG_TQM860L 284 CONFIG_ETX094 CONFIG_NETPHONE CONFIG_TTTech 285 CONFIG_EVB64260 CONFIG_NETTA CONFIG_UTX8245 286 CONFIG_FADS823 CONFIG_NETVIA CONFIG_V37 287 CONFIG_FADS850SAR CONFIG_NX823 CONFIG_W7OLMC 288 CONFIG_FADS860T CONFIG_OCRTC CONFIG_W7OLMG 289 CONFIG_FLAGADM CONFIG_ORSG CONFIG_WALNUT405 290 CONFIG_FPS850L CONFIG_OXC CONFIG_ZPC1900 291 CONFIG_FPS860L CONFIG_ZUMA 292 293 ARM based boards: 294 ----------------- 295 296 CONFIG_AT91RM9200DK, CONFIG_CERF250, CONFIG_DNP1110, 297 CONFIG_EP7312, CONFIG_H2_OMAP1610, CONFIG_HHP_CRADLE, 298 CONFIG_IMPA7, CONFIG_INNOVATOROMAP1510, CONFIG_INNOVATOROMAP1610, 299 CONFIG_LART, CONFIG_LPD7A400 CONFIG_LUBBOCK, 300 CONFIG_OSK_OMAP5912, CONFIG_SHANNON, CONFIG_P2_OMAP730, 301 CONFIG_SMDK2400, CONFIG_SMDK2410, CONFIG_TRAB, 302 CONFIG_VCMA9 303 304 MicroBlaze based boards: 305 ------------------------ 306 307 CONFIG_SUZAKU 308 309 310- CPU Module Type: (if CONFIG_COGENT is defined) 311 Define exactly one of 312 CONFIG_CMA286_60_OLD 313--- FIXME --- not tested yet: 314 CONFIG_CMA286_60, CONFIG_CMA286_21, CONFIG_CMA286_60P, 315 CONFIG_CMA287_23, CONFIG_CMA287_50 316 317- Motherboard Type: (if CONFIG_COGENT is defined) 318 Define exactly one of 319 CONFIG_CMA101, CONFIG_CMA102 320 321- Motherboard I/O Modules: (if CONFIG_COGENT is defined) 322 Define one or more of 323 CONFIG_CMA302 324 325- Motherboard Options: (if CONFIG_CMA101 or CONFIG_CMA102 are defined) 326 Define one or more of 327 CONFIG_LCD_HEARTBEAT - update a character position on 328 the lcd display every second with 329 a "rotator" |\-/|\-/ 330 331- Board flavour: (if CONFIG_MPC8260ADS is defined) 332 CONFIG_ADSTYPE 333 Possible values are: 334 CFG_8260ADS - original MPC8260ADS 335 CFG_8266ADS - MPC8266ADS 336 CFG_PQ2FADS - PQ2FADS-ZU or PQ2FADS-VR 337 CFG_8272ADS - MPC8272ADS 338 339- MPC824X Family Member (if CONFIG_MPC824X is defined) 340 Define exactly one of 341 CONFIG_MPC8240, CONFIG_MPC8245 342 343- 8xx CPU Options: (if using an MPC8xx cpu) 344 CONFIG_8xx_GCLK_FREQ - deprecated: CPU clock if 345 get_gclk_freq() cannot work 346 e.g. if there is no 32KHz 347 reference PIT/RTC clock 348 CONFIG_8xx_OSCLK - PLL input clock (either EXTCLK 349 or XTAL/EXTAL) 350 351- 859/866/885 CPU options: (if using a MPC859 or MPC866 or MPC885 CPU): 352 CFG_8xx_CPUCLK_MIN 353 CFG_8xx_CPUCLK_MAX 354 CONFIG_8xx_CPUCLK_DEFAULT 355 See doc/README.MPC866 356 357 CFG_MEASURE_CPUCLK 358 359 Define this to measure the actual CPU clock instead 360 of relying on the correctness of the configured 361 values. Mostly useful for board bringup to make sure 362 the PLL is locked at the intended frequency. Note 363 that this requires a (stable) reference clock (32 kHz 364 RTC clock or CFG_8XX_XIN) 365 366- Linux Kernel Interface: 367 CONFIG_CLOCKS_IN_MHZ 368 369 U-Boot stores all clock information in Hz 370 internally. For binary compatibility with older Linux 371 kernels (which expect the clocks passed in the 372 bd_info data to be in MHz) the environment variable 373 "clocks_in_mhz" can be defined so that U-Boot 374 converts clock data to MHZ before passing it to the 375 Linux kernel. 376 When CONFIG_CLOCKS_IN_MHZ is defined, a definition of 377 "clocks_in_mhz=1" is automatically included in the 378 default environment. 379 380 CONFIG_MEMSIZE_IN_BYTES [relevant for MIPS only] 381 382 When transfering memsize parameter to linux, some versions 383 expect it to be in bytes, others in MB. 384 Define CONFIG_MEMSIZE_IN_BYTES to make it in bytes. 385 386- Serial Ports: 387 CFG_PL010_SERIAL 388 389 Define this if you want support for Amba PrimeCell PL010 UARTs. 390 391 CFG_PL011_SERIAL 392 393 Define this if you want support for Amba PrimeCell PL011 UARTs. 394 395 CONFIG_PL011_CLOCK 396 397 If you have Amba PrimeCell PL011 UARTs, set this variable to 398 the clock speed of the UARTs. 399 400 CONFIG_PL01x_PORTS 401 402 If you have Amba PrimeCell PL010 or PL011 UARTs on your board, 403 define this to a list of base addresses for each (supported) 404 port. See e.g. include/configs/versatile.h 405 406 407- Console Interface: 408 Depending on board, define exactly one serial port 409 (like CONFIG_8xx_CONS_SMC1, CONFIG_8xx_CONS_SMC2, 410 CONFIG_8xx_CONS_SCC1, ...), or switch off the serial 411 console by defining CONFIG_8xx_CONS_NONE 412 413 Note: if CONFIG_8xx_CONS_NONE is defined, the serial 414 port routines must be defined elsewhere 415 (i.e. serial_init(), serial_getc(), ...) 416 417 CONFIG_CFB_CONSOLE 418 Enables console device for a color framebuffer. Needs following 419 defines (cf. smiLynxEM, i8042, board/eltec/bab7xx) 420 VIDEO_FB_LITTLE_ENDIAN graphic memory organisation 421 (default big endian) 422 VIDEO_HW_RECTFILL graphic chip supports 423 rectangle fill 424 (cf. smiLynxEM) 425 VIDEO_HW_BITBLT graphic chip supports 426 bit-blit (cf. smiLynxEM) 427 VIDEO_VISIBLE_COLS visible pixel columns 428 (cols=pitch) 429 VIDEO_VISIBLE_ROWS visible pixel rows 430 VIDEO_PIXEL_SIZE bytes per pixel 431 VIDEO_DATA_FORMAT graphic data format 432 (0-5, cf. cfb_console.c) 433 VIDEO_FB_ADRS framebuffer address 434 VIDEO_KBD_INIT_FCT keyboard int fct 435 (i.e. i8042_kbd_init()) 436 VIDEO_TSTC_FCT test char fct 437 (i.e. i8042_tstc) 438 VIDEO_GETC_FCT get char fct 439 (i.e. i8042_getc) 440 CONFIG_CONSOLE_CURSOR cursor drawing on/off 441 (requires blink timer 442 cf. i8042.c) 443 CFG_CONSOLE_BLINK_COUNT blink interval (cf. i8042.c) 444 CONFIG_CONSOLE_TIME display time/date info in 445 upper right corner 446 (requires CFG_CMD_DATE) 447 CONFIG_VIDEO_LOGO display Linux logo in 448 upper left corner 449 CONFIG_VIDEO_BMP_LOGO use bmp_logo.h instead of 450 linux_logo.h for logo. 451 Requires CONFIG_VIDEO_LOGO 452 CONFIG_CONSOLE_EXTRA_INFO 453 addional board info beside 454 the logo 455 456 When CONFIG_CFB_CONSOLE is defined, video console is 457 default i/o. Serial console can be forced with 458 environment 'console=serial'. 459 460 When CONFIG_SILENT_CONSOLE is defined, all console 461 messages (by U-Boot and Linux!) can be silenced with 462 the "silent" environment variable. See 463 doc/README.silent for more information. 464 465- Console Baudrate: 466 CONFIG_BAUDRATE - in bps 467 Select one of the baudrates listed in 468 CFG_BAUDRATE_TABLE, see below. 469 CFG_BRGCLK_PRESCALE, baudrate prescale 470 471- Interrupt driven serial port input: 472 CONFIG_SERIAL_SOFTWARE_FIFO 473 474 PPC405GP only. 475 Use an interrupt handler for receiving data on the 476 serial port. It also enables using hardware handshake 477 (RTS/CTS) and UART's built-in FIFO. Set the number of 478 bytes the interrupt driven input buffer should have. 479 480 Leave undefined to disable this feature, including 481 disable the buffer and hardware handshake. 482 483- Console UART Number: 484 CONFIG_UART1_CONSOLE 485 486 IBM PPC4xx only. 487 If defined internal UART1 (and not UART0) is used 488 as default U-Boot console. 489 490- Boot Delay: CONFIG_BOOTDELAY - in seconds 491 Delay before automatically booting the default image; 492 set to -1 to disable autoboot. 493 494 See doc/README.autoboot for these options that 495 work with CONFIG_BOOTDELAY. None are required. 496 CONFIG_BOOT_RETRY_TIME 497 CONFIG_BOOT_RETRY_MIN 498 CONFIG_AUTOBOOT_KEYED 499 CONFIG_AUTOBOOT_PROMPT 500 CONFIG_AUTOBOOT_DELAY_STR 501 CONFIG_AUTOBOOT_STOP_STR 502 CONFIG_AUTOBOOT_DELAY_STR2 503 CONFIG_AUTOBOOT_STOP_STR2 504 CONFIG_ZERO_BOOTDELAY_CHECK 505 CONFIG_RESET_TO_RETRY 506 507- Autoboot Command: 508 CONFIG_BOOTCOMMAND 509 Only needed when CONFIG_BOOTDELAY is enabled; 510 define a command string that is automatically executed 511 when no character is read on the console interface 512 within "Boot Delay" after reset. 513 514 CONFIG_BOOTARGS 515 This can be used to pass arguments to the bootm 516 command. The value of CONFIG_BOOTARGS goes into the 517 environment value "bootargs". 518 519 CONFIG_RAMBOOT and CONFIG_NFSBOOT 520 The value of these goes into the environment as 521 "ramboot" and "nfsboot" respectively, and can be used 522 as a convenience, when switching between booting from 523 ram and nfs. 524 525- Pre-Boot Commands: 526 CONFIG_PREBOOT 527 528 When this option is #defined, the existence of the 529 environment variable "preboot" will be checked 530 immediately before starting the CONFIG_BOOTDELAY 531 countdown and/or running the auto-boot command resp. 532 entering interactive mode. 533 534 This feature is especially useful when "preboot" is 535 automatically generated or modified. For an example 536 see the LWMON board specific code: here "preboot" is 537 modified when the user holds down a certain 538 combination of keys on the (special) keyboard when 539 booting the systems 540 541- Serial Download Echo Mode: 542 CONFIG_LOADS_ECHO 543 If defined to 1, all characters received during a 544 serial download (using the "loads" command) are 545 echoed back. This might be needed by some terminal 546 emulations (like "cu"), but may as well just take 547 time on others. This setting #define's the initial 548 value of the "loads_echo" environment variable. 549 550- Kgdb Serial Baudrate: (if CFG_CMD_KGDB is defined) 551 CONFIG_KGDB_BAUDRATE 552 Select one of the baudrates listed in 553 CFG_BAUDRATE_TABLE, see below. 554 555- Monitor Functions: 556 CONFIG_COMMANDS 557 Most monitor functions can be selected (or 558 de-selected) by adjusting the definition of 559 CONFIG_COMMANDS; to select individual functions, 560 #define CONFIG_COMMANDS by "OR"ing any of the 561 following values: 562 563 #define enables commands: 564 ------------------------- 565 CFG_CMD_ASKENV * ask for env variable 566 CFG_CMD_AUTOSCRIPT Autoscript Support 567 CFG_CMD_BDI bdinfo 568 CFG_CMD_BEDBUG * Include BedBug Debugger 569 CFG_CMD_BMP * BMP support 570 CFG_CMD_BSP * Board specific commands 571 CFG_CMD_BOOTD bootd 572 CFG_CMD_CACHE * icache, dcache 573 CFG_CMD_CONSOLE coninfo 574 CFG_CMD_DATE * support for RTC, date/time... 575 CFG_CMD_DHCP * DHCP support 576 CFG_CMD_DIAG * Diagnostics 577 CFG_CMD_DOC * Disk-On-Chip Support 578 CFG_CMD_DTT * Digital Therm and Thermostat 579 CFG_CMD_ECHO * echo arguments 580 CFG_CMD_EEPROM * EEPROM read/write support 581 CFG_CMD_ELF * bootelf, bootvx 582 CFG_CMD_ENV saveenv 583 CFG_CMD_FDC * Floppy Disk Support 584 CFG_CMD_FAT * FAT partition support 585 CFG_CMD_FDOS * Dos diskette Support 586 CFG_CMD_FLASH flinfo, erase, protect 587 CFG_CMD_FPGA FPGA device initialization support 588 CFG_CMD_HWFLOW * RTS/CTS hw flow control 589 CFG_CMD_I2C * I2C serial bus support 590 CFG_CMD_IDE * IDE harddisk support 591 CFG_CMD_IMI iminfo 592 CFG_CMD_IMLS List all found images 593 CFG_CMD_IMMAP * IMMR dump support 594 CFG_CMD_IRQ * irqinfo 595 CFG_CMD_ITEST Integer/string test of 2 values 596 CFG_CMD_JFFS2 * JFFS2 Support 597 CFG_CMD_KGDB * kgdb 598 CFG_CMD_LOADB loadb 599 CFG_CMD_LOADS loads 600 CFG_CMD_MEMORY md, mm, nm, mw, cp, cmp, crc, base, 601 loop, loopw, mtest 602 CFG_CMD_MISC Misc functions like sleep etc 603 CFG_CMD_MMC * MMC memory mapped support 604 CFG_CMD_MII * MII utility commands 605 CFG_CMD_NAND * NAND support 606 CFG_CMD_NET bootp, tftpboot, rarpboot 607 CFG_CMD_PCI * pciinfo 608 CFG_CMD_PCMCIA * PCMCIA support 609 CFG_CMD_PING * send ICMP ECHO_REQUEST to network host 610 CFG_CMD_PORTIO * Port I/O 611 CFG_CMD_REGINFO * Register dump 612 CFG_CMD_RUN run command in env variable 613 CFG_CMD_SAVES * save S record dump 614 CFG_CMD_SCSI * SCSI Support 615 CFG_CMD_SDRAM * print SDRAM configuration information 616 CFG_CMD_SETGETDCR Support for DCR Register access (4xx only) 617 CFG_CMD_SPI * SPI serial bus support 618 CFG_CMD_USB * USB support 619 CFG_CMD_VFD * VFD support (TRAB) 620 CFG_CMD_BSP * Board SPecific functions 621 CFG_CMD_CDP * Cisco Discover Protocol support 622 ----------------------------------------------- 623 CFG_CMD_ALL all 624 625 CONFIG_CMD_DFL Default configuration; at the moment 626 this is includes all commands, except 627 the ones marked with "*" in the list 628 above. 629 630 If you don't define CONFIG_COMMANDS it defaults to 631 CONFIG_CMD_DFL in include/cmd_confdefs.h. A board can 632 override the default settings in the respective 633 include file. 634 635 EXAMPLE: If you want all functions except of network 636 support you can write: 637 638 #define CONFIG_COMMANDS (CFG_CMD_ALL & ~CFG_CMD_NET) 639 640 641 Note: Don't enable the "icache" and "dcache" commands 642 (configuration option CFG_CMD_CACHE) unless you know 643 what you (and your U-Boot users) are doing. Data 644 cache cannot be enabled on systems like the 8xx or 645 8260 (where accesses to the IMMR region must be 646 uncached), and it cannot be disabled on all other 647 systems where we (mis-) use the data cache to hold an 648 initial stack and some data. 649 650 651 XXX - this list needs to get updated! 652 653- Watchdog: 654 CONFIG_WATCHDOG 655 If this variable is defined, it enables watchdog 656 support. There must be support in the platform specific 657 code for a watchdog. For the 8xx and 8260 CPUs, the 658 SIU Watchdog feature is enabled in the SYPCR 659 register. 660 661- U-Boot Version: 662 CONFIG_VERSION_VARIABLE 663 If this variable is defined, an environment variable 664 named "ver" is created by U-Boot showing the U-Boot 665 version as printed by the "version" command. 666 This variable is readonly. 667 668- Real-Time Clock: 669 670 When CFG_CMD_DATE is selected, the type of the RTC 671 has to be selected, too. Define exactly one of the 672 following options: 673 674 CONFIG_RTC_MPC8xx - use internal RTC of MPC8xx 675 CONFIG_RTC_PCF8563 - use Philips PCF8563 RTC 676 CONFIG_RTC_MC146818 - use MC146818 RTC 677 CONFIG_RTC_DS1307 - use Maxim, Inc. DS1307 RTC 678 CONFIG_RTC_DS1337 - use Maxim, Inc. DS1337 RTC 679 CONFIG_RTC_DS1338 - use Maxim, Inc. DS1338 RTC 680 CONFIG_RTC_DS164x - use Dallas DS164x RTC 681 CONFIG_RTC_MAX6900 - use Maxim, Inc. MAX6900 RTC 682 683 Note that if the RTC uses I2C, then the I2C interface 684 must also be configured. See I2C Support, below. 685 686- Timestamp Support: 687 688 When CONFIG_TIMESTAMP is selected, the timestamp 689 (date and time) of an image is printed by image 690 commands like bootm or iminfo. This option is 691 automatically enabled when you select CFG_CMD_DATE . 692 693- Partition Support: 694 CONFIG_MAC_PARTITION and/or CONFIG_DOS_PARTITION 695 and/or CONFIG_ISO_PARTITION 696 697 If IDE or SCSI support is enabled (CFG_CMD_IDE or 698 CFG_CMD_SCSI) you must configure support for at least 699 one partition type as well. 700 701- IDE Reset method: 702 CONFIG_IDE_RESET_ROUTINE - this is defined in several 703 board configurations files but used nowhere! 704 705 CONFIG_IDE_RESET - is this is defined, IDE Reset will 706 be performed by calling the function 707 ide_set_reset(int reset) 708 which has to be defined in a board specific file 709 710- ATAPI Support: 711 CONFIG_ATAPI 712 713 Set this to enable ATAPI support. 714 715- LBA48 Support 716 CONFIG_LBA48 717 718 Set this to enable support for disks larger than 137GB 719 Also look at CFG_64BIT_LBA ,CFG_64BIT_VSPRINTF and CFG_64BIT_STRTOUL 720 Whithout these , LBA48 support uses 32bit variables and will 'only' 721 support disks up to 2.1TB. 722 723 CFG_64BIT_LBA: 724 When enabled, makes the IDE subsystem use 64bit sector addresses. 725 Default is 32bit. 726 727- SCSI Support: 728 At the moment only there is only support for the 729 SYM53C8XX SCSI controller; define 730 CONFIG_SCSI_SYM53C8XX to enable it. 731 732 CFG_SCSI_MAX_LUN [8], CFG_SCSI_MAX_SCSI_ID [7] and 733 CFG_SCSI_MAX_DEVICE [CFG_SCSI_MAX_SCSI_ID * 734 CFG_SCSI_MAX_LUN] can be adjusted to define the 735 maximum numbers of LUNs, SCSI ID's and target 736 devices. 737 CFG_SCSI_SYM53C8XX_CCF to fix clock timing (80Mhz) 738 739- NETWORK Support (PCI): 740 CONFIG_E1000 741 Support for Intel 8254x gigabit chips. 742 743 CONFIG_EEPRO100 744 Support for Intel 82557/82559/82559ER chips. 745 Optional CONFIG_EEPRO100_SROM_WRITE enables eeprom 746 write routine for first time initialisation. 747 748 CONFIG_TULIP 749 Support for Digital 2114x chips. 750 Optional CONFIG_TULIP_SELECT_MEDIA for board specific 751 modem chip initialisation (KS8761/QS6611). 752 753 CONFIG_NATSEMI 754 Support for National dp83815 chips. 755 756 CONFIG_NS8382X 757 Support for National dp8382[01] gigabit chips. 758 759- NETWORK Support (other): 760 761 CONFIG_DRIVER_LAN91C96 762 Support for SMSC's LAN91C96 chips. 763 764 CONFIG_LAN91C96_BASE 765 Define this to hold the physical address 766 of the LAN91C96's I/O space 767 768 CONFIG_LAN91C96_USE_32_BIT 769 Define this to enable 32 bit addressing 770 771 CONFIG_DRIVER_SMC91111 772 Support for SMSC's LAN91C111 chip 773 774 CONFIG_SMC91111_BASE 775 Define this to hold the physical address 776 of the device (I/O space) 777 778 CONFIG_SMC_USE_32_BIT 779 Define this if data bus is 32 bits 780 781 CONFIG_SMC_USE_IOFUNCS 782 Define this to use i/o functions instead of macros 783 (some hardware wont work with macros) 784 785- USB Support: 786 At the moment only the UHCI host controller is 787 supported (PIP405, MIP405, MPC5200); define 788 CONFIG_USB_UHCI to enable it. 789 define CONFIG_USB_KEYBOARD to enable the USB Keyboard 790 end define CONFIG_USB_STORAGE to enable the USB 791 storage devices. 792 Note: 793 Supported are USB Keyboards and USB Floppy drives 794 (TEAC FD-05PUB). 795 MPC5200 USB requires additional defines: 796 CONFIG_USB_CLOCK 797 for 528 MHz Clock: 0x0001bbbb 798 CONFIG_USB_CONFIG 799 for differential drivers: 0x00001000 800 for single ended drivers: 0x00005000 801 802 803- MMC Support: 804 The MMC controller on the Intel PXA is supported. To 805 enable this define CONFIG_MMC. The MMC can be 806 accessed from the boot prompt by mapping the device 807 to physical memory similar to flash. Command line is 808 enabled with CFG_CMD_MMC. The MMC driver also works with 809 the FAT fs. This is enabled with CFG_CMD_FAT. 810 811- Journaling Flash filesystem support: 812 CONFIG_JFFS2_NAND, CONFIG_JFFS2_NAND_OFF, CONFIG_JFFS2_NAND_SIZE, 813 CONFIG_JFFS2_NAND_DEV 814 Define these for a default partition on a NAND device 815 816 CFG_JFFS2_FIRST_SECTOR, 817 CFG_JFFS2_FIRST_BANK, CFG_JFFS2_NUM_BANKS 818 Define these for a default partition on a NOR device 819 820 CFG_JFFS_CUSTOM_PART 821 Define this to create an own partition. You have to provide a 822 function struct part_info* jffs2_part_info(int part_num) 823 824 If you define only one JFFS2 partition you may also want to 825 #define CFG_JFFS_SINGLE_PART 1 826 to disable the command chpart. This is the default when you 827 have not defined a custom partition 828 829- Keyboard Support: 830 CONFIG_ISA_KEYBOARD 831 832 Define this to enable standard (PC-Style) keyboard 833 support 834 835 CONFIG_I8042_KBD 836 Standard PC keyboard driver with US (is default) and 837 GERMAN key layout (switch via environment 'keymap=de') support. 838 Export function i8042_kbd_init, i8042_tstc and i8042_getc 839 for cfb_console. Supports cursor blinking. 840 841- Video support: 842 CONFIG_VIDEO 843 844 Define this to enable video support (for output to 845 video). 846 847 CONFIG_VIDEO_CT69000 848 849 Enable Chips & Technologies 69000 Video chip 850 851 CONFIG_VIDEO_SMI_LYNXEM 852 Enable Silicon Motion SMI 712/710/810 Video chip. The 853 video output is selected via environment 'videoout' 854 (1 = LCD and 2 = CRT). If videoout is undefined, CRT is 855 assumed. 856 857 For the CT69000 and SMI_LYNXEM drivers, videomode is 858 selected via environment 'videomode'. Two diferent ways 859 are possible: 860 - "videomode=num" 'num' is a standard LiLo mode numbers. 861 Following standard modes are supported (* is default): 862 863 Colors 640x480 800x600 1024x768 1152x864 1280x1024 864 -------------+--------------------------------------------- 865 8 bits | 0x301* 0x303 0x305 0x161 0x307 866 15 bits | 0x310 0x313 0x316 0x162 0x319 867 16 bits | 0x311 0x314 0x317 0x163 0x31A 868 24 bits | 0x312 0x315 0x318 ? 0x31B 869 -------------+--------------------------------------------- 870 (i.e. setenv videomode 317; saveenv; reset;) 871 872 - "videomode=bootargs" all the video parameters are parsed 873 from the bootargs. (See drivers/videomodes.c) 874 875 876 CONFIG_VIDEO_SED13806 877 Enable Epson SED13806 driver. This driver supports 8bpp 878 and 16bpp modes defined by CONFIG_VIDEO_SED13806_8BPP 879 or CONFIG_VIDEO_SED13806_16BPP 880 881- Keyboard Support: 882 CONFIG_KEYBOARD 883 884 Define this to enable a custom keyboard support. 885 This simply calls drv_keyboard_init() which must be 886 defined in your board-specific files. 887 The only board using this so far is RBC823. 888 889- LCD Support: CONFIG_LCD 890 891 Define this to enable LCD support (for output to LCD 892 display); also select one of the supported displays 893 by defining one of these: 894 895 CONFIG_NEC_NL6448AC33: 896 897 NEC NL6448AC33-18. Active, color, single scan. 898 899 CONFIG_NEC_NL6448BC20 900 901 NEC NL6448BC20-08. 6.5", 640x480. 902 Active, color, single scan. 903 904 CONFIG_NEC_NL6448BC33_54 905 906 NEC NL6448BC33-54. 10.4", 640x480. 907 Active, color, single scan. 908 909 CONFIG_SHARP_16x9 910 911 Sharp 320x240. Active, color, single scan. 912 It isn't 16x9, and I am not sure what it is. 913 914 CONFIG_SHARP_LQ64D341 915 916 Sharp LQ64D341 display, 640x480. 917 Active, color, single scan. 918 919 CONFIG_HLD1045 920 921 HLD1045 display, 640x480. 922 Active, color, single scan. 923 924 CONFIG_OPTREX_BW 925 926 Optrex CBL50840-2 NF-FW 99 22 M5 927 or 928 Hitachi LMG6912RPFC-00T 929 or 930 Hitachi SP14Q002 931 932 320x240. Black & white. 933 934 Normally display is black on white background; define 935 CFG_WHITE_ON_BLACK to get it inverted. 936 937- Splash Screen Support: CONFIG_SPLASH_SCREEN 938 939 If this option is set, the environment is checked for 940 a variable "splashimage". If found, the usual display 941 of logo, copyright and system information on the LCD 942 is suppressed and the BMP image at the address 943 specified in "splashimage" is loaded instead. The 944 console is redirected to the "nulldev", too. This 945 allows for a "silent" boot where a splash screen is 946 loaded very quickly after power-on. 947 948- Compression support: 949 CONFIG_BZIP2 950 951 If this option is set, support for bzip2 compressed 952 images is included. If not, only uncompressed and gzip 953 compressed images are supported. 954 955 NOTE: the bzip2 algorithm requires a lot of RAM, so 956 the malloc area (as defined by CFG_MALLOC_LEN) should 957 be at least 4MB. 958 959- MII/PHY support: 960 CONFIG_PHY_ADDR 961 962 The address of PHY on MII bus. 963 964 CONFIG_PHY_CLOCK_FREQ (ppc4xx) 965 966 The clock frequency of the MII bus 967 968 CONFIG_PHY_GIGE 969 970 If this option is set, support for speed/duplex 971 detection of Gigabit PHY is included. 972 973 CONFIG_PHY_RESET_DELAY 974 975 Some PHY like Intel LXT971A need extra delay after 976 reset before any MII register access is possible. 977 For such PHY, set this option to the usec delay 978 required. (minimum 300usec for LXT971A) 979 980 CONFIG_PHY_CMD_DELAY (ppc4xx) 981 982 Some PHY like Intel LXT971A need extra delay after 983 command issued before MII status register can be read 984 985- Ethernet address: 986 CONFIG_ETHADDR 987 CONFIG_ETH2ADDR 988 CONFIG_ETH3ADDR 989 990 Define a default value for ethernet address to use 991 for the respective ethernet interface, in case this 992 is not determined automatically. 993 994- IP address: 995 CONFIG_IPADDR 996 997 Define a default value for the IP address to use for 998 the default ethernet interface, in case this is not 999 determined through e.g. bootp. 1000 1001- Server IP address: 1002 CONFIG_SERVERIP 1003 1004 Defines a default value for theIP address of a TFTP 1005 server to contact when using the "tftboot" command. 1006 1007- BOOTP Recovery Mode: 1008 CONFIG_BOOTP_RANDOM_DELAY 1009 1010 If you have many targets in a network that try to 1011 boot using BOOTP, you may want to avoid that all 1012 systems send out BOOTP requests at precisely the same 1013 moment (which would happen for instance at recovery 1014 from a power failure, when all systems will try to 1015 boot, thus flooding the BOOTP server. Defining 1016 CONFIG_BOOTP_RANDOM_DELAY causes a random delay to be 1017 inserted before sending out BOOTP requests. The 1018 following delays are insterted then: 1019 1020 1st BOOTP request: delay 0 ... 1 sec 1021 2nd BOOTP request: delay 0 ... 2 sec 1022 3rd BOOTP request: delay 0 ... 4 sec 1023 4th and following 1024 BOOTP requests: delay 0 ... 8 sec 1025 1026- DHCP Advanced Options: 1027 CONFIG_BOOTP_MASK 1028 1029 You can fine tune the DHCP functionality by adding 1030 these flags to the CONFIG_BOOTP_MASK define: 1031 1032 CONFIG_BOOTP_DNS2 - If a DHCP client requests the DNS 1033 serverip from a DHCP server, it is possible that more 1034 than one DNS serverip is offered to the client. 1035 If CONFIG_BOOTP_DNS2 is enabled, the secondary DNS 1036 serverip will be stored in the additional environment 1037 variable "dnsip2". The first DNS serverip is always 1038 stored in the variable "dnsip", when CONFIG_BOOTP_DNS 1039 is added to the CONFIG_BOOTP_MASK. 1040 1041 CONFIG_BOOTP_SEND_HOSTNAME - Some DHCP servers are capable 1042 to do a dynamic update of a DNS server. To do this, they 1043 need the hostname of the DHCP requester. 1044 If CONFIG_BOOP_SEND_HOSTNAME is added to the 1045 CONFIG_BOOTP_MASK, the content of the "hostname" 1046 environment variable is passed as option 12 to 1047 the DHCP server. 1048 1049 - CDP Options: 1050 CONFIG_CDP_DEVICE_ID 1051 1052 The device id used in CDP trigger frames. 1053 1054 CONFIG_CDP_DEVICE_ID_PREFIX 1055 1056 A two character string which is prefixed to the MAC address 1057 of the device. 1058 1059 CONFIG_CDP_PORT_ID 1060 1061 A printf format string which contains the ascii name of 1062 the port. Normally is set to "eth%d" which sets 1063 eth0 for the first ethernet, eth1 for the second etc. 1064 1065 CONFIG_CDP_CAPABILITIES 1066 1067 A 32bit integer which indicates the device capabilities; 1068 0x00000010 for a normal host which does not forwards. 1069 1070 CONFIG_CDP_VERSION 1071 1072 An ascii string containing the version of the software. 1073 1074 CONFIG_CDP_PLATFORM 1075 1076 An ascii string containing the name of the platform. 1077 1078 CONFIG_CDP_TRIGGER 1079 1080 A 32bit integer sent on the trigger. 1081 1082 CONFIG_CDP_POWER_CONSUMPTION 1083 1084 A 16bit integer containing the power consumption of the 1085 device in .1 of milliwatts. 1086 1087 CONFIG_CDP_APPLIANCE_VLAN_TYPE 1088 1089 A byte containing the id of the VLAN. 1090 1091- Status LED: CONFIG_STATUS_LED 1092 1093 Several configurations allow to display the current 1094 status using a LED. For instance, the LED will blink 1095 fast while running U-Boot code, stop blinking as 1096 soon as a reply to a BOOTP request was received, and 1097 start blinking slow once the Linux kernel is running 1098 (supported by a status LED driver in the Linux 1099 kernel). Defining CONFIG_STATUS_LED enables this 1100 feature in U-Boot. 1101 1102- CAN Support: CONFIG_CAN_DRIVER 1103 1104 Defining CONFIG_CAN_DRIVER enables CAN driver support 1105 on those systems that support this (optional) 1106 feature, like the TQM8xxL modules. 1107 1108- I2C Support: CONFIG_HARD_I2C | CONFIG_SOFT_I2C 1109 1110 These enable I2C serial bus commands. Defining either of 1111 (but not both of) CONFIG_HARD_I2C or CONFIG_SOFT_I2C will 1112 include the appropriate I2C driver for the selected cpu. 1113 1114 This will allow you to use i2c commands at the u-boot 1115 command line (as long as you set CFG_CMD_I2C in 1116 CONFIG_COMMANDS) and communicate with i2c based realtime 1117 clock chips. See common/cmd_i2c.c for a description of the 1118 command line interface. 1119 1120 CONFIG_HARD_I2C selects the CPM hardware driver for I2C. 1121 1122 CONFIG_SOFT_I2C configures u-boot to use a software (aka 1123 bit-banging) driver instead of CPM or similar hardware 1124 support for I2C. 1125 1126 There are several other quantities that must also be 1127 defined when you define CONFIG_HARD_I2C or CONFIG_SOFT_I2C. 1128 1129 In both cases you will need to define CFG_I2C_SPEED 1130 to be the frequency (in Hz) at which you wish your i2c bus 1131 to run and CFG_I2C_SLAVE to be the address of this node (ie 1132 the cpu's i2c node address). 1133 1134 Now, the u-boot i2c code for the mpc8xx (cpu/mpc8xx/i2c.c) 1135 sets the cpu up as a master node and so its address should 1136 therefore be cleared to 0 (See, eg, MPC823e User's Manual 1137 p.16-473). So, set CFG_I2C_SLAVE to 0. 1138 1139 That's all that's required for CONFIG_HARD_I2C. 1140 1141 If you use the software i2c interface (CONFIG_SOFT_I2C) 1142 then the following macros need to be defined (examples are 1143 from include/configs/lwmon.h): 1144 1145 I2C_INIT 1146 1147 (Optional). Any commands necessary to enable the I2C 1148 controller or configure ports. 1149 1150 eg: #define I2C_INIT (immr->im_cpm.cp_pbdir |= PB_SCL) 1151 1152 I2C_PORT 1153 1154 (Only for MPC8260 CPU). The I/O port to use (the code 1155 assumes both bits are on the same port). Valid values 1156 are 0..3 for ports A..D. 1157 1158 I2C_ACTIVE 1159 1160 The code necessary to make the I2C data line active 1161 (driven). If the data line is open collector, this 1162 define can be null. 1163 1164 eg: #define I2C_ACTIVE (immr->im_cpm.cp_pbdir |= PB_SDA) 1165 1166 I2C_TRISTATE 1167 1168 The code necessary to make the I2C data line tri-stated 1169 (inactive). If the data line is open collector, this 1170 define can be null. 1171 1172 eg: #define I2C_TRISTATE (immr->im_cpm.cp_pbdir &= ~PB_SDA) 1173 1174 I2C_READ 1175 1176 Code that returns TRUE if the I2C data line is high, 1177 FALSE if it is low. 1178 1179 eg: #define I2C_READ ((immr->im_cpm.cp_pbdat & PB_SDA) != 0) 1180 1181 I2C_SDA(bit) 1182 1183 If <bit> is TRUE, sets the I2C data line high. If it 1184 is FALSE, it clears it (low). 1185 1186 eg: #define I2C_SDA(bit) \ 1187 if(bit) immr->im_cpm.cp_pbdat |= PB_SDA; \ 1188 else immr->im_cpm.cp_pbdat &= ~PB_SDA 1189 1190 I2C_SCL(bit) 1191 1192 If <bit> is TRUE, sets the I2C clock line high. If it 1193 is FALSE, it clears it (low). 1194 1195 eg: #define I2C_SCL(bit) \ 1196 if(bit) immr->im_cpm.cp_pbdat |= PB_SCL; \ 1197 else immr->im_cpm.cp_pbdat &= ~PB_SCL 1198 1199 I2C_DELAY 1200 1201 This delay is invoked four times per clock cycle so this 1202 controls the rate of data transfer. The data rate thus 1203 is 1 / (I2C_DELAY * 4). Often defined to be something 1204 like: 1205 1206 #define I2C_DELAY udelay(2) 1207 1208 CFG_I2C_INIT_BOARD 1209 1210 When a board is reset during an i2c bus transfer 1211 chips might think that the current transfer is still 1212 in progress. On some boards it is possible to access 1213 the i2c SCLK line directly, either by using the 1214 processor pin as a GPIO or by having a second pin 1215 connected to the bus. If this option is defined a 1216 custom i2c_init_board() routine in boards/xxx/board.c 1217 is run early in the boot sequence. 1218 1219 CONFIG_I2CFAST (PPC405GP|PPC405EP only) 1220 1221 This option enables configuration of bi_iic_fast[] flags 1222 in u-boot bd_info structure based on u-boot environment 1223 variable "i2cfast". (see also i2cfast) 1224 1225- SPI Support: CONFIG_SPI 1226 1227 Enables SPI driver (so far only tested with 1228 SPI EEPROM, also an instance works with Crystal A/D and 1229 D/As on the SACSng board) 1230 1231 CONFIG_SPI_X 1232 1233 Enables extended (16-bit) SPI EEPROM addressing. 1234 (symmetrical to CONFIG_I2C_X) 1235 1236 CONFIG_SOFT_SPI 1237 1238 Enables a software (bit-bang) SPI driver rather than 1239 using hardware support. This is a general purpose 1240 driver that only requires three general I/O port pins 1241 (two outputs, one input) to function. If this is 1242 defined, the board configuration must define several 1243 SPI configuration items (port pins to use, etc). For 1244 an example, see include/configs/sacsng.h. 1245 1246- FPGA Support: CONFIG_FPGA_COUNT 1247 1248 Specify the number of FPGA devices to support. 1249 1250 CONFIG_FPGA 1251 1252 Used to specify the types of FPGA devices. For example, 1253 #define CONFIG_FPGA CFG_XILINX_VIRTEX2 1254 1255 CFG_FPGA_PROG_FEEDBACK 1256 1257 Enable printing of hash marks during FPGA configuration. 1258 1259 CFG_FPGA_CHECK_BUSY 1260 1261 Enable checks on FPGA configuration interface busy 1262 status by the configuration function. This option 1263 will require a board or device specific function to 1264 be written. 1265 1266 CONFIG_FPGA_DELAY 1267 1268 If defined, a function that provides delays in the FPGA 1269 configuration driver. 1270 1271 CFG_FPGA_CHECK_CTRLC 1272 Allow Control-C to interrupt FPGA configuration 1273 1274 CFG_FPGA_CHECK_ERROR 1275 1276 Check for configuration errors during FPGA bitfile 1277 loading. For example, abort during Virtex II 1278 configuration if the INIT_B line goes low (which 1279 indicated a CRC error). 1280 1281 CFG_FPGA_WAIT_INIT 1282 1283 Maximum time to wait for the INIT_B line to deassert 1284 after PROB_B has been deasserted during a Virtex II 1285 FPGA configuration sequence. The default time is 500 1286 mS. 1287 1288 CFG_FPGA_WAIT_BUSY 1289 1290 Maximum time to wait for BUSY to deassert during 1291 Virtex II FPGA configuration. The default is 5 mS. 1292 1293 CFG_FPGA_WAIT_CONFIG 1294 1295 Time to wait after FPGA configuration. The default is 1296 200 mS. 1297 1298- Configuration Management: 1299 CONFIG_IDENT_STRING 1300 1301 If defined, this string will be added to the U-Boot 1302 version information (U_BOOT_VERSION) 1303 1304- Vendor Parameter Protection: 1305 1306 U-Boot considers the values of the environment 1307 variables "serial#" (Board Serial Number) and 1308 "ethaddr" (Ethernet Address) to be parameters that 1309 are set once by the board vendor / manufacturer, and 1310 protects these variables from casual modification by 1311 the user. Once set, these variables are read-only, 1312 and write or delete attempts are rejected. You can 1313 change this behviour: 1314 1315 If CONFIG_ENV_OVERWRITE is #defined in your config 1316 file, the write protection for vendor parameters is 1317 completely disabled. Anybody can change or delete 1318 these parameters. 1319 1320 Alternatively, if you #define _both_ CONFIG_ETHADDR 1321 _and_ CONFIG_OVERWRITE_ETHADDR_ONCE, a default 1322 ethernet address is installed in the environment, 1323 which can be changed exactly ONCE by the user. [The 1324 serial# is unaffected by this, i. e. it remains 1325 read-only.] 1326 1327- Protected RAM: 1328 CONFIG_PRAM 1329 1330 Define this variable to enable the reservation of 1331 "protected RAM", i. e. RAM which is not overwritten 1332 by U-Boot. Define CONFIG_PRAM to hold the number of 1333 kB you want to reserve for pRAM. You can overwrite 1334 this default value by defining an environment 1335 variable "pram" to the number of kB you want to 1336 reserve. Note that the board info structure will 1337 still show the full amount of RAM. If pRAM is 1338 reserved, a new environment variable "mem" will 1339 automatically be defined to hold the amount of 1340 remaining RAM in a form that can be passed as boot 1341 argument to Linux, for instance like that: 1342 1343 setenv bootargs ... mem=\$(mem) 1344 saveenv 1345 1346 This way you can tell Linux not to use this memory, 1347 either, which results in a memory region that will 1348 not be affected by reboots. 1349 1350 *WARNING* If your board configuration uses automatic 1351 detection of the RAM size, you must make sure that 1352 this memory test is non-destructive. So far, the 1353 following board configurations are known to be 1354 "pRAM-clean": 1355 1356 ETX094, IVMS8, IVML24, SPD8xx, TQM8xxL, 1357 HERMES, IP860, RPXlite, LWMON, LANTEC, 1358 PCU_E, FLAGADM, TQM8260 1359 1360- Error Recovery: 1361 CONFIG_PANIC_HANG 1362 1363 Define this variable to stop the system in case of a 1364 fatal error, so that you have to reset it manually. 1365 This is probably NOT a good idea for an embedded 1366 system where you want to system to reboot 1367 automatically as fast as possible, but it may be 1368 useful during development since you can try to debug 1369 the conditions that lead to the situation. 1370 1371 CONFIG_NET_RETRY_COUNT 1372 1373 This variable defines the number of retries for 1374 network operations like ARP, RARP, TFTP, or BOOTP 1375 before giving up the operation. If not defined, a 1376 default value of 5 is used. 1377 1378- Command Interpreter: 1379 CFG_AUTO_COMPLETE 1380 1381 Enable auto completion of commands using TAB. 1382 1383 CFG_HUSH_PARSER 1384 1385 Define this variable to enable the "hush" shell (from 1386 Busybox) as command line interpreter, thus enabling 1387 powerful command line syntax like 1388 if...then...else...fi conditionals or `&&' and '||' 1389 constructs ("shell scripts"). 1390 1391 If undefined, you get the old, much simpler behaviour 1392 with a somewhat smaller memory footprint. 1393 1394 1395 CFG_PROMPT_HUSH_PS2 1396 1397 This defines the secondary prompt string, which is 1398 printed when the command interpreter needs more input 1399 to complete a command. Usually "> ". 1400 1401 Note: 1402 1403 In the current implementation, the local variables 1404 space and global environment variables space are 1405 separated. Local variables are those you define by 1406 simply typing `name=value'. To access a local 1407 variable later on, you have write `$name' or 1408 `${name}'; to execute the contents of a variable 1409 directly type `$name' at the command prompt. 1410 1411 Global environment variables are those you use 1412 setenv/printenv to work with. To run a command stored 1413 in such a variable, you need to use the run command, 1414 and you must not use the '$' sign to access them. 1415 1416 To store commands and special characters in a 1417 variable, please use double quotation marks 1418 surrounding the whole text of the variable, instead 1419 of the backslashes before semicolons and special 1420 symbols. 1421 1422- Default Environment: 1423 CONFIG_EXTRA_ENV_SETTINGS 1424 1425 Define this to contain any number of null terminated 1426 strings (variable = value pairs) that will be part of 1427 the default environment compiled into the boot image. 1428 1429 For example, place something like this in your 1430 board's config file: 1431 1432 #define CONFIG_EXTRA_ENV_SETTINGS \ 1433 "myvar1=value1\0" \ 1434 "myvar2=value2\0" 1435 1436 Warning: This method is based on knowledge about the 1437 internal format how the environment is stored by the 1438 U-Boot code. This is NOT an official, exported 1439 interface! Although it is unlikely that this format 1440 will change soon, there is no guarantee either. 1441 You better know what you are doing here. 1442 1443 Note: overly (ab)use of the default environment is 1444 discouraged. Make sure to check other ways to preset 1445 the environment like the autoscript function or the 1446 boot command first. 1447 1448- DataFlash Support: 1449 CONFIG_HAS_DATAFLASH 1450 1451 Defining this option enables DataFlash features and 1452 allows to read/write in Dataflash via the standard 1453 commands cp, md... 1454 1455- SystemACE Support: 1456 CONFIG_SYSTEMACE 1457 1458 Adding this option adds support for Xilinx SystemACE 1459 chips attached via some sort of local bus. The address 1460 of the chip must alsh be defined in the 1461 CFG_SYSTEMACE_BASE macro. For example: 1462 1463 #define CONFIG_SYSTEMACE 1464 #define CFG_SYSTEMACE_BASE 0xf0000000 1465 1466 When SystemACE support is added, the "ace" device type 1467 becomes available to the fat commands, i.e. fatls. 1468 1469- Show boot progress: 1470 CONFIG_SHOW_BOOT_PROGRESS 1471 1472 Defining this option allows to add some board- 1473 specific code (calling a user-provided function 1474 "show_boot_progress(int)") that enables you to show 1475 the system's boot progress on some display (for 1476 example, some LED's) on your board. At the moment, 1477 the following checkpoints are implemented: 1478 1479 Arg Where When 1480 1 common/cmd_bootm.c before attempting to boot an image 1481 -1 common/cmd_bootm.c Image header has bad magic number 1482 2 common/cmd_bootm.c Image header has correct magic number 1483 -2 common/cmd_bootm.c Image header has bad checksum 1484 3 common/cmd_bootm.c Image header has correct checksum 1485 -3 common/cmd_bootm.c Image data has bad checksum 1486 4 common/cmd_bootm.c Image data has correct checksum 1487 -4 common/cmd_bootm.c Image is for unsupported architecture 1488 5 common/cmd_bootm.c Architecture check OK 1489 -5 common/cmd_bootm.c Wrong Image Type (not kernel, multi, standalone) 1490 6 common/cmd_bootm.c Image Type check OK 1491 -6 common/cmd_bootm.c gunzip uncompression error 1492 -7 common/cmd_bootm.c Unimplemented compression type 1493 7 common/cmd_bootm.c Uncompression OK 1494 -8 common/cmd_bootm.c Wrong Image Type (not kernel, multi, standalone) 1495 8 common/cmd_bootm.c Image Type check OK 1496 -9 common/cmd_bootm.c Unsupported OS (not Linux, BSD, VxWorks, QNX) 1497 9 common/cmd_bootm.c Start initial ramdisk verification 1498 -10 common/cmd_bootm.c Ramdisk header has bad magic number 1499 -11 common/cmd_bootm.c Ramdisk header has bad checksum 1500 10 common/cmd_bootm.c Ramdisk header is OK 1501 -12 common/cmd_bootm.c Ramdisk data has bad checksum 1502 11 common/cmd_bootm.c Ramdisk data has correct checksum 1503 12 common/cmd_bootm.c Ramdisk verification complete, start loading 1504 -13 common/cmd_bootm.c Wrong Image Type (not PPC Linux Ramdisk) 1505 13 common/cmd_bootm.c Start multifile image verification 1506 14 common/cmd_bootm.c No initial ramdisk, no multifile, continue. 1507 15 common/cmd_bootm.c All preparation done, transferring control to OS 1508 1509 -30 lib_ppc/board.c Fatal error, hang the system 1510 -31 post/post.c POST test failed, detected by post_output_backlog() 1511 -32 post/post.c POST test failed, detected by post_run_single() 1512 1513 -1 common/cmd_doc.c Bad usage of "doc" command 1514 -1 common/cmd_doc.c No boot device 1515 -1 common/cmd_doc.c Unknown Chip ID on boot device 1516 -1 common/cmd_doc.c Read Error on boot device 1517 -1 common/cmd_doc.c Image header has bad magic number 1518 1519 -1 common/cmd_ide.c Bad usage of "ide" command 1520 -1 common/cmd_ide.c No boot device 1521 -1 common/cmd_ide.c Unknown boot device 1522 -1 common/cmd_ide.c Unknown partition table 1523 -1 common/cmd_ide.c Invalid partition type 1524 -1 common/cmd_ide.c Read Error on boot device 1525 -1 common/cmd_ide.c Image header has bad magic number 1526 1527 -1 common/cmd_nand.c Bad usage of "nand" command 1528 -1 common/cmd_nand.c No boot device 1529 -1 common/cmd_nand.c Unknown Chip ID on boot device 1530 -1 common/cmd_nand.c Read Error on boot device 1531 -1 common/cmd_nand.c Image header has bad magic number 1532 1533 -1 common/env_common.c Environment has a bad CRC, using default 1534 1535 1536Modem Support: 1537-------------- 1538 1539[so far only for SMDK2400 and TRAB boards] 1540 1541- Modem support endable: 1542 CONFIG_MODEM_SUPPORT 1543 1544- RTS/CTS Flow control enable: 1545 CONFIG_HWFLOW 1546 1547- Modem debug support: 1548 CONFIG_MODEM_SUPPORT_DEBUG 1549 1550 Enables debugging stuff (char screen[1024], dbg()) 1551 for modem support. Useful only with BDI2000. 1552 1553- Interrupt support (PPC): 1554 1555 There are common interrupt_init() and timer_interrupt() 1556 for all PPC archs. interrupt_init() calls interrupt_init_cpu() 1557 for cpu specific initialization. interrupt_init_cpu() 1558 should set decrementer_count to appropriate value. If 1559 cpu resets decrementer automatically after interrupt 1560 (ppc4xx) it should set decrementer_count to zero. 1561 timer_interrupt() calls timer_interrupt_cpu() for cpu 1562 specific handling. If board has watchdog / status_led 1563 / other_activity_monitor it works automatically from 1564 general timer_interrupt(). 1565 1566- General: 1567 1568 In the target system modem support is enabled when a 1569 specific key (key combination) is pressed during 1570 power-on. Otherwise U-Boot will boot normally 1571 (autoboot). The key_pressed() fuction is called from 1572 board_init(). Currently key_pressed() is a dummy 1573 function, returning 1 and thus enabling modem 1574 initialization. 1575 1576 If there are no modem init strings in the 1577 environment, U-Boot proceed to autoboot; the 1578 previous output (banner, info printfs) will be 1579 supressed, though. 1580 1581 See also: doc/README.Modem 1582 1583 1584Configuration Settings: 1585----------------------- 1586 1587- CFG_LONGHELP: Defined when you want long help messages included; 1588 undefine this when you're short of memory. 1589 1590- CFG_PROMPT: This is what U-Boot prints on the console to 1591 prompt for user input. 1592 1593- CFG_CBSIZE: Buffer size for input from the Console 1594 1595- CFG_PBSIZE: Buffer size for Console output 1596 1597- CFG_MAXARGS: max. Number of arguments accepted for monitor commands 1598 1599- CFG_BARGSIZE: Buffer size for Boot Arguments which are passed to 1600 the application (usually a Linux kernel) when it is 1601 booted 1602 1603- CFG_BAUDRATE_TABLE: 1604 List of legal baudrate settings for this board. 1605 1606- CFG_CONSOLE_INFO_QUIET 1607 Suppress display of console information at boot. 1608 1609- CFG_CONSOLE_IS_IN_ENV 1610 If the board specific function 1611 extern int overwrite_console (void); 1612 returns 1, the stdin, stderr and stdout are switched to the 1613 serial port, else the settings in the environment are used. 1614 1615- CFG_CONSOLE_OVERWRITE_ROUTINE 1616 Enable the call to overwrite_console(). 1617 1618- CFG_CONSOLE_ENV_OVERWRITE 1619 Enable overwrite of previous console environment settings. 1620 1621- CFG_MEMTEST_START, CFG_MEMTEST_END: 1622 Begin and End addresses of the area used by the 1623 simple memory test. 1624 1625- CFG_ALT_MEMTEST: 1626 Enable an alternate, more extensive memory test. 1627 1628- CFG_MEMTEST_SCRATCH: 1629 Scratch address used by the alternate memory test 1630 You only need to set this if address zero isn't writeable 1631 1632- CFG_TFTP_LOADADDR: 1633 Default load address for network file downloads 1634 1635- CFG_LOADS_BAUD_CHANGE: 1636 Enable temporary baudrate change while serial download 1637 1638- CFG_SDRAM_BASE: 1639 Physical start address of SDRAM. _Must_ be 0 here. 1640 1641- CFG_MBIO_BASE: 1642 Physical start address of Motherboard I/O (if using a 1643 Cogent motherboard) 1644 1645- CFG_FLASH_BASE: 1646 Physical start address of Flash memory. 1647 1648- CFG_MONITOR_BASE: 1649 Physical start address of boot monitor code (set by 1650 make config files to be same as the text base address 1651 (TEXT_BASE) used when linking) - same as 1652 CFG_FLASH_BASE when booting from flash. 1653 1654- CFG_MONITOR_LEN: 1655 Size of memory reserved for monitor code, used to 1656 determine _at_compile_time_ (!) if the environment is 1657 embedded within the U-Boot image, or in a separate 1658 flash sector. 1659 1660- CFG_MALLOC_LEN: 1661 Size of DRAM reserved for malloc() use. 1662 1663- CFG_BOOTMAPSZ: 1664 Maximum size of memory mapped by the startup code of 1665 the Linux kernel; all data that must be processed by 1666 the Linux kernel (bd_info, boot arguments, eventually 1667 initrd image) must be put below this limit. 1668 1669- CFG_MAX_FLASH_BANKS: 1670 Max number of Flash memory banks 1671 1672- CFG_MAX_FLASH_SECT: 1673 Max number of sectors on a Flash chip 1674 1675- CFG_FLASH_ERASE_TOUT: 1676 Timeout for Flash erase operations (in ms) 1677 1678- CFG_FLASH_WRITE_TOUT: 1679 Timeout for Flash write operations (in ms) 1680 1681- CFG_FLASH_LOCK_TOUT 1682 Timeout for Flash set sector lock bit operation (in ms) 1683 1684- CFG_FLASH_UNLOCK_TOUT 1685 Timeout for Flash clear lock bits operation (in ms) 1686 1687- CFG_FLASH_PROTECTION 1688 If defined, hardware flash sectors protection is used 1689 instead of U-Boot software protection. 1690 1691- CFG_DIRECT_FLASH_TFTP: 1692 1693 Enable TFTP transfers directly to flash memory; 1694 without this option such a download has to be 1695 performed in two steps: (1) download to RAM, and (2) 1696 copy from RAM to flash. 1697 1698 The two-step approach is usually more reliable, since 1699 you can check if the download worked before you erase 1700 the flash, but in some situations (when sytem RAM is 1701 too limited to allow for a tempory copy of the 1702 downloaded image) this option may be very useful. 1703 1704- CFG_FLASH_CFI: 1705 Define if the flash driver uses extra elements in the 1706 common flash structure for storing flash geometry. 1707 1708- CFG_FLASH_CFI_DRIVER 1709 This option also enables the building of the cfi_flash driver 1710 in the drivers directory 1711 1712- CFG_RX_ETH_BUFFER: 1713 Defines the number of ethernet receive buffers. On some 1714 ethernet controllers it is recommended to set this value 1715 to 8 or even higher (EEPRO100 or 405 EMAC), since all 1716 buffers can be full shortly after enabling the interface 1717 on high ethernet traffic. 1718 Defaults to 4 if not defined. 1719 1720The following definitions that deal with the placement and management 1721of environment data (variable area); in general, we support the 1722following configurations: 1723 1724- CFG_ENV_IS_IN_FLASH: 1725 1726 Define this if the environment is in flash memory. 1727 1728 a) The environment occupies one whole flash sector, which is 1729 "embedded" in the text segment with the U-Boot code. This 1730 happens usually with "bottom boot sector" or "top boot 1731 sector" type flash chips, which have several smaller 1732 sectors at the start or the end. For instance, such a 1733 layout can have sector sizes of 8, 2x4, 16, Nx32 kB. In 1734 such a case you would place the environment in one of the 1735 4 kB sectors - with U-Boot code before and after it. With 1736 "top boot sector" type flash chips, you would put the 1737 environment in one of the last sectors, leaving a gap 1738 between U-Boot and the environment. 1739 1740 - CFG_ENV_OFFSET: 1741 1742 Offset of environment data (variable area) to the 1743 beginning of flash memory; for instance, with bottom boot 1744 type flash chips the second sector can be used: the offset 1745 for this sector is given here. 1746 1747 CFG_ENV_OFFSET is used relative to CFG_FLASH_BASE. 1748 1749 - CFG_ENV_ADDR: 1750 1751 This is just another way to specify the start address of 1752 the flash sector containing the environment (instead of 1753 CFG_ENV_OFFSET). 1754 1755 - CFG_ENV_SECT_SIZE: 1756 1757 Size of the sector containing the environment. 1758 1759 1760 b) Sometimes flash chips have few, equal sized, BIG sectors. 1761 In such a case you don't want to spend a whole sector for 1762 the environment. 1763 1764 - CFG_ENV_SIZE: 1765 1766 If you use this in combination with CFG_ENV_IS_IN_FLASH 1767 and CFG_ENV_SECT_SIZE, you can specify to use only a part 1768 of this flash sector for the environment. This saves 1769 memory for the RAM copy of the environment. 1770 1771 It may also save flash memory if you decide to use this 1772 when your environment is "embedded" within U-Boot code, 1773 since then the remainder of the flash sector could be used 1774 for U-Boot code. It should be pointed out that this is 1775 STRONGLY DISCOURAGED from a robustness point of view: 1776 updating the environment in flash makes it always 1777 necessary to erase the WHOLE sector. If something goes 1778 wrong before the contents has been restored from a copy in 1779 RAM, your target system will be dead. 1780 1781 - CFG_ENV_ADDR_REDUND 1782 CFG_ENV_SIZE_REDUND 1783 1784 These settings describe a second storage area used to hold 1785 a redundand copy of the environment data, so that there is 1786 a valid backup copy in case there is a power failure during 1787 a "saveenv" operation. 1788 1789BE CAREFUL! Any changes to the flash layout, and some changes to the 1790source code will make it necessary to adapt <board>/u-boot.lds* 1791accordingly! 1792 1793 1794- CFG_ENV_IS_IN_NVRAM: 1795 1796 Define this if you have some non-volatile memory device 1797 (NVRAM, battery buffered SRAM) which you want to use for the 1798 environment. 1799 1800 - CFG_ENV_ADDR: 1801 - CFG_ENV_SIZE: 1802 1803 These two #defines are used to determin the memory area you 1804 want to use for environment. It is assumed that this memory 1805 can just be read and written to, without any special 1806 provision. 1807 1808BE CAREFUL! The first access to the environment happens quite early 1809in U-Boot initalization (when we try to get the setting of for the 1810console baudrate). You *MUST* have mappend your NVRAM area then, or 1811U-Boot will hang. 1812 1813Please note that even with NVRAM we still use a copy of the 1814environment in RAM: we could work on NVRAM directly, but we want to 1815keep settings there always unmodified except somebody uses "saveenv" 1816to save the current settings. 1817 1818 1819- CFG_ENV_IS_IN_EEPROM: 1820 1821 Use this if you have an EEPROM or similar serial access 1822 device and a driver for it. 1823 1824 - CFG_ENV_OFFSET: 1825 - CFG_ENV_SIZE: 1826 1827 These two #defines specify the offset and size of the 1828 environment area within the total memory of your EEPROM. 1829 1830 - CFG_I2C_EEPROM_ADDR: 1831 If defined, specified the chip address of the EEPROM device. 1832 The default address is zero. 1833 1834 - CFG_EEPROM_PAGE_WRITE_BITS: 1835 If defined, the number of bits used to address bytes in a 1836 single page in the EEPROM device. A 64 byte page, for example 1837 would require six bits. 1838 1839 - CFG_EEPROM_PAGE_WRITE_DELAY_MS: 1840 If defined, the number of milliseconds to delay between 1841 page writes. The default is zero milliseconds. 1842 1843 - CFG_I2C_EEPROM_ADDR_LEN: 1844 The length in bytes of the EEPROM memory array address. Note 1845 that this is NOT the chip address length! 1846 1847 - CFG_I2C_EEPROM_ADDR_OVERFLOW: 1848 EEPROM chips that implement "address overflow" are ones 1849 like Catalyst 24WC04/08/16 which has 9/10/11 bits of 1850 address and the extra bits end up in the "chip address" bit 1851 slots. This makes a 24WC08 (1Kbyte) chip look like four 256 1852 byte chips. 1853 1854 Note that we consider the length of the address field to 1855 still be one byte because the extra address bits are hidden 1856 in the chip address. 1857 1858 - CFG_EEPROM_SIZE: 1859 The size in bytes of the EEPROM device. 1860 1861 1862- CFG_ENV_IS_IN_DATAFLASH: 1863 1864 Define this if you have a DataFlash memory device which you 1865 want to use for the environment. 1866 1867 - CFG_ENV_OFFSET: 1868 - CFG_ENV_ADDR: 1869 - CFG_ENV_SIZE: 1870 1871 These three #defines specify the offset and size of the 1872 environment area within the total memory of your DataFlash placed 1873 at the specified address. 1874 1875- CFG_ENV_IS_IN_NAND: 1876 1877 Define this if you have a NAND device which you want to use 1878 for the environment. 1879 1880 - CFG_ENV_OFFSET: 1881 - CFG_ENV_SIZE: 1882 1883 These two #defines specify the offset and size of the environment 1884 area within the first NAND device. 1885 1886- CFG_SPI_INIT_OFFSET 1887 1888 Defines offset to the initial SPI buffer area in DPRAM. The 1889 area is used at an early stage (ROM part) if the environment 1890 is configured to reside in the SPI EEPROM: We need a 520 byte 1891 scratch DPRAM area. It is used between the two initialization 1892 calls (spi_init_f() and spi_init_r()). A value of 0xB00 seems 1893 to be a good choice since it makes it far enough from the 1894 start of the data area as well as from the stack pointer. 1895 1896Please note that the environment is read-only as long as the monitor 1897has been relocated to RAM and a RAM copy of the environment has been 1898created; also, when using EEPROM you will have to use getenv_r() 1899until then to read environment variables. 1900 1901The environment is protected by a CRC32 checksum. Before the monitor 1902is relocated into RAM, as a result of a bad CRC you will be working 1903with the compiled-in default environment - *silently*!!! [This is 1904necessary, because the first environment variable we need is the 1905"baudrate" setting for the console - if we have a bad CRC, we don't 1906have any device yet where we could complain.] 1907 1908Note: once the monitor has been relocated, then it will complain if 1909the default environment is used; a new CRC is computed as soon as you 1910use the "saveenv" command to store a valid environment. 1911 1912- CFG_FAULT_ECHO_LINK_DOWN: 1913 Echo the inverted Ethernet link state to the fault LED. 1914 1915 Note: If this option is active, then CFG_FAULT_MII_ADDR 1916 also needs to be defined. 1917 1918- CFG_FAULT_MII_ADDR: 1919 MII address of the PHY to check for the Ethernet link state. 1920 1921- CFG_64BIT_VSPRINTF: 1922 Makes vsprintf (and all *printf functions) support printing 1923 of 64bit values by using the L quantifier 1924 1925- CFG_64BIT_STRTOUL: 1926 Adds simple_strtoull that returns a 64bit value 1927 1928Low Level (hardware related) configuration options: 1929--------------------------------------------------- 1930 1931- CFG_CACHELINE_SIZE: 1932 Cache Line Size of the CPU. 1933 1934- CFG_DEFAULT_IMMR: 1935 Default address of the IMMR after system reset. 1936 1937 Needed on some 8260 systems (MPC8260ADS, PQ2FADS-ZU, 1938 and RPXsuper) to be able to adjust the position of 1939 the IMMR register after a reset. 1940 1941- Floppy Disk Support: 1942 CFG_FDC_DRIVE_NUMBER 1943 1944 the default drive number (default value 0) 1945 1946 CFG_ISA_IO_STRIDE 1947 1948 defines the spacing between fdc chipset registers 1949 (default value 1) 1950 1951 CFG_ISA_IO_OFFSET 1952 1953 defines the offset of register from address. It 1954 depends on which part of the data bus is connected to 1955 the fdc chipset. (default value 0) 1956 1957 If CFG_ISA_IO_STRIDE CFG_ISA_IO_OFFSET and 1958 CFG_FDC_DRIVE_NUMBER are undefined, they take their 1959 default value. 1960 1961 if CFG_FDC_HW_INIT is defined, then the function 1962 fdc_hw_init() is called at the beginning of the FDC 1963 setup. fdc_hw_init() must be provided by the board 1964 source code. It is used to make hardware dependant 1965 initializations. 1966 1967- CFG_IMMR: Physical address of the Internal Memory Mapped 1968 Register; DO NOT CHANGE! (11-4) 1969 [MPC8xx systems only] 1970 1971- CFG_INIT_RAM_ADDR: 1972 1973 Start address of memory area that can be used for 1974 initial data and stack; please note that this must be 1975 writable memory that is working WITHOUT special 1976 initialization, i. e. you CANNOT use normal RAM which 1977 will become available only after programming the 1978 memory controller and running certain initialization 1979 sequences. 1980 1981 U-Boot uses the following memory types: 1982 - MPC8xx and MPC8260: IMMR (internal memory of the CPU) 1983 - MPC824X: data cache 1984 - PPC4xx: data cache 1985 1986- CFG_GBL_DATA_OFFSET: 1987 1988 Offset of the initial data structure in the memory 1989 area defined by CFG_INIT_RAM_ADDR. Usually 1990 CFG_GBL_DATA_OFFSET is chosen such that the initial 1991 data is located at the end of the available space 1992 (sometimes written as (CFG_INIT_RAM_END - 1993 CFG_INIT_DATA_SIZE), and the initial stack is just 1994 below that area (growing from (CFG_INIT_RAM_ADDR + 1995 CFG_GBL_DATA_OFFSET) downward. 1996 1997 Note: 1998 On the MPC824X (or other systems that use the data 1999 cache for initial memory) the address chosen for 2000 CFG_INIT_RAM_ADDR is basically arbitrary - it must 2001 point to an otherwise UNUSED address space between 2002 the top of RAM and the start of the PCI space. 2003 2004- CFG_SIUMCR: SIU Module Configuration (11-6) 2005 2006- CFG_SYPCR: System Protection Control (11-9) 2007 2008- CFG_TBSCR: Time Base Status and Control (11-26) 2009 2010- CFG_PISCR: Periodic Interrupt Status and Control (11-31) 2011 2012- CFG_PLPRCR: PLL, Low-Power, and Reset Control Register (15-30) 2013 2014- CFG_SCCR: System Clock and reset Control Register (15-27) 2015 2016- CFG_OR_TIMING_SDRAM: 2017 SDRAM timing 2018 2019- CFG_MAMR_PTA: 2020 periodic timer for refresh 2021 2022- CFG_DER: Debug Event Register (37-47) 2023 2024- FLASH_BASE0_PRELIM, FLASH_BASE1_PRELIM, CFG_REMAP_OR_AM, 2025 CFG_PRELIM_OR_AM, CFG_OR_TIMING_FLASH, CFG_OR0_REMAP, 2026 CFG_OR0_PRELIM, CFG_BR0_PRELIM, CFG_OR1_REMAP, CFG_OR1_PRELIM, 2027 CFG_BR1_PRELIM: 2028 Memory Controller Definitions: BR0/1 and OR0/1 (FLASH) 2029 2030- SDRAM_BASE2_PRELIM, SDRAM_BASE3_PRELIM, SDRAM_MAX_SIZE, 2031 CFG_OR_TIMING_SDRAM, CFG_OR2_PRELIM, CFG_BR2_PRELIM, 2032 CFG_OR3_PRELIM, CFG_BR3_PRELIM: 2033 Memory Controller Definitions: BR2/3 and OR2/3 (SDRAM) 2034 2035- CFG_MAMR_PTA, CFG_MPTPR_2BK_4K, CFG_MPTPR_1BK_4K, CFG_MPTPR_2BK_8K, 2036 CFG_MPTPR_1BK_8K, CFG_MAMR_8COL, CFG_MAMR_9COL: 2037 Machine Mode Register and Memory Periodic Timer 2038 Prescaler definitions (SDRAM timing) 2039 2040- CFG_I2C_UCODE_PATCH, CFG_I2C_DPMEM_OFFSET [0x1FC0]: 2041 enable I2C microcode relocation patch (MPC8xx); 2042 define relocation offset in DPRAM [DSP2] 2043 2044- CFG_SPI_UCODE_PATCH, CFG_SPI_DPMEM_OFFSET [0x1FC0]: 2045 enable SPI microcode relocation patch (MPC8xx); 2046 define relocation offset in DPRAM [SCC4] 2047 2048- CFG_USE_OSCCLK: 2049 Use OSCM clock mode on MBX8xx board. Be careful, 2050 wrong setting might damage your board. Read 2051 doc/README.MBX before setting this variable! 2052 2053- CFG_CPM_POST_WORD_ADDR: (MPC8xx, MPC8260 only) 2054 Offset of the bootmode word in DPRAM used by post 2055 (Power On Self Tests). This definition overrides 2056 #define'd default value in commproc.h resp. 2057 cpm_8260.h. 2058 2059- CFG_PCI_SLV_MEM_LOCAL, CFG_PCI_SLV_MEM_BUS, CFG_PICMR0_MASK_ATTRIB, 2060 CFG_PCI_MSTR0_LOCAL, CFG_PCIMSK0_MASK, CFG_PCI_MSTR1_LOCAL, 2061 CFG_PCIMSK1_MASK, CFG_PCI_MSTR_MEM_LOCAL, CFG_PCI_MSTR_MEM_BUS, 2062 CFG_CPU_PCI_MEM_START, CFG_PCI_MSTR_MEM_SIZE, CFG_POCMR0_MASK_ATTRIB, 2063 CFG_PCI_MSTR_MEMIO_LOCAL, CFG_PCI_MSTR_MEMIO_BUS, CPU_PCI_MEMIO_START, 2064 CFG_PCI_MSTR_MEMIO_SIZE, CFG_POCMR1_MASK_ATTRIB, CFG_PCI_MSTR_IO_LOCAL, 2065 CFG_PCI_MSTR_IO_BUS, CFG_CPU_PCI_IO_START, CFG_PCI_MSTR_IO_SIZE, 2066 CFG_POCMR2_MASK_ATTRIB: (MPC826x only) 2067 Overrides the default PCI memory map in cpu/mpc8260/pci.c if set. 2068 2069- CONFIG_ETHER_ON_FEC[12] 2070 Define to enable FEC[12] on a 8xx series processor. 2071 2072- CONFIG_FEC[12]_PHY 2073 Define to the hardcoded PHY address which corresponds 2074 to the given FEC; i. e. 2075 #define CONFIG_FEC1_PHY 4 2076 means that the PHY with address 4 is connected to FEC1 2077 2078 When set to -1, means to probe for first available. 2079 2080- CONFIG_FEC[12]_PHY_NORXERR 2081 The PHY does not have a RXERR line (RMII only). 2082 (so program the FEC to ignore it). 2083 2084- CONFIG_RMII 2085 Enable RMII mode for all FECs. 2086 Note that this is a global option, we can't 2087 have one FEC in standard MII mode and another in RMII mode. 2088 2089- CONFIG_CRC32_VERIFY 2090 Add a verify option to the crc32 command. 2091 The syntax is: 2092 2093 => crc32 -v <address> <count> <crc32> 2094 2095 Where address/count indicate a memory area 2096 and crc32 is the correct crc32 which the 2097 area should have. 2098 2099- CONFIG_LOOPW 2100 Add the "loopw" memory command. This only takes effect if 2101 the memory commands are activated globally (CFG_CMD_MEM). 2102 2103Building the Software: 2104====================== 2105 2106Building U-Boot has been tested in native PPC environments (on a 2107PowerBook G3 running LinuxPPC 2000) and in cross environments 2108(running RedHat 6.x and 7.x Linux on x86, Solaris 2.6 on a SPARC, and 2109NetBSD 1.5 on x86). 2110 2111If you are not using a native PPC environment, it is assumed that you 2112have the GNU cross compiling tools available in your path and named 2113with a prefix of "powerpc-linux-". If this is not the case, (e.g. if 2114you are using Monta Vista's Hard Hat Linux CDK 1.2) you must change 2115the definition of CROSS_COMPILE in Makefile. For HHL on a 4xx CPU, 2116change it to: 2117 2118 CROSS_COMPILE = ppc_4xx- 2119 2120 2121U-Boot is intended to be simple to build. After installing the 2122sources you must configure U-Boot for one specific board type. This 2123is done by typing: 2124 2125 make NAME_config 2126 2127where "NAME_config" is the name of one of the existing 2128configurations; the following names are supported: 2129 2130 ADCIOP_config FPS860L_config omap730p2_config 2131 ADS860_config GEN860T_config pcu_e_config 2132 AR405_config GENIETV_config PIP405_config 2133 at91rm9200dk_config GTH_config QS823_config 2134 CANBT_config hermes_config QS850_config 2135 cmi_mpc5xx_config hymod_config QS860T_config 2136 cogent_common_config IP860_config RPXlite_config 2137 cogent_mpc8260_config IVML24_config RPXlite_DW_config 2138 cogent_mpc8xx_config IVMS8_config RPXsuper_config 2139 CPCI405_config JSE_config rsdproto_config 2140 CPCIISER4_config LANTEC_config Sandpoint8240_config 2141 csb272_config lwmon_config sbc8260_config 2142 CU824_config MBX860T_config sbc8560_33_config 2143 DUET_ADS_config MBX_config sbc8560_66_config 2144 EBONY_config MPC8260ADS_config SM850_config 2145 ELPT860_config MPC8540ADS_config SPD823TS_config 2146 ESTEEM192E_config MPC8560ADS_config stxgp3_config 2147 ETX094_config NETVIA_config SXNI855T_config 2148 FADS823_config omap1510inn_config TQM823L_config 2149 FADS850SAR_config omap1610h2_config TQM850L_config 2150 FADS860T_config omap1610inn_config TQM855L_config 2151 FPS850L_config omap5912osk_config TQM860L_config 2152 WALNUT405_config 2153 ZPC1900_config 2154 2155Note: for some board special configuration names may exist; check if 2156 additional information is available from the board vendor; for 2157 instance, the TQM823L systems are available without (standard) 2158 or with LCD support. You can select such additional "features" 2159 when chosing the configuration, i. e. 2160 2161 make TQM823L_config 2162 - will configure for a plain TQM823L, i. e. no LCD support 2163 2164 make TQM823L_LCD_config 2165 - will configure for a TQM823L with U-Boot console on LCD 2166 2167 etc. 2168 2169 2170Finally, type "make all", and you should get some working U-Boot 2171images ready for download to / installation on your system: 2172 2173- "u-boot.bin" is a raw binary image 2174- "u-boot" is an image in ELF binary format 2175- "u-boot.srec" is in Motorola S-Record format 2176 2177 2178Please be aware that the Makefiles assume you are using GNU make, so 2179for instance on NetBSD you might need to use "gmake" instead of 2180native "make". 2181 2182 2183If the system board that you have is not listed, then you will need 2184to port U-Boot to your hardware platform. To do this, follow these 2185steps: 2186 21871. Add a new configuration option for your board to the toplevel 2188 "Makefile" and to the "MAKEALL" script, using the existing 2189 entries as examples. Note that here and at many other places 2190 boards and other names are listed in alphabetical sort order. Please 2191 keep this order. 21922. Create a new directory to hold your board specific code. Add any 2193 files you need. In your board directory, you will need at least 2194 the "Makefile", a "<board>.c", "flash.c" and "u-boot.lds". 21953. Create a new configuration file "include/configs/<board>.h" for 2196 your board 21973. If you're porting U-Boot to a new CPU, then also create a new 2198 directory to hold your CPU specific code. Add any files you need. 21994. Run "make <board>_config" with your new name. 22005. Type "make", and you should get a working "u-boot.srec" file 2201 to be installed on your target system. 22026. Debug and solve any problems that might arise. 2203 [Of course, this last step is much harder than it sounds.] 2204 2205 2206Testing of U-Boot Modifications, Ports to New Hardware, etc.: 2207============================================================== 2208 2209If you have modified U-Boot sources (for instance added a new board 2210or support for new devices, a new CPU, etc.) you are expected to 2211provide feedback to the other developers. The feedback normally takes 2212the form of a "patch", i. e. a context diff against a certain (latest 2213official or latest in CVS) version of U-Boot sources. 2214 2215But before you submit such a patch, please verify that your modifi- 2216cation did not break existing code. At least make sure that *ALL* of 2217the supported boards compile WITHOUT ANY compiler warnings. To do so, 2218just run the "MAKEALL" script, which will configure and build U-Boot 2219for ALL supported system. Be warned, this will take a while. You can 2220select which (cross) compiler to use by passing a `CROSS_COMPILE' 2221environment variable to the script, i. e. to use the cross tools from 2222MontaVista's Hard Hat Linux you can type 2223 2224 CROSS_COMPILE=ppc_8xx- MAKEALL 2225 2226or to build on a native PowerPC system you can type 2227 2228 CROSS_COMPILE=' ' MAKEALL 2229 2230See also "U-Boot Porting Guide" below. 2231 2232 2233Monitor Commands - Overview: 2234============================ 2235 2236go - start application at address 'addr' 2237run - run commands in an environment variable 2238bootm - boot application image from memory 2239bootp - boot image via network using BootP/TFTP protocol 2240tftpboot- boot image via network using TFTP protocol 2241 and env variables "ipaddr" and "serverip" 2242 (and eventually "gatewayip") 2243rarpboot- boot image via network using RARP/TFTP protocol 2244diskboot- boot from IDE devicebootd - boot default, i.e., run 'bootcmd' 2245loads - load S-Record file over serial line 2246loadb - load binary file over serial line (kermit mode) 2247md - memory display 2248mm - memory modify (auto-incrementing) 2249nm - memory modify (constant address) 2250mw - memory write (fill) 2251cp - memory copy 2252cmp - memory compare 2253crc32 - checksum calculation 2254imd - i2c memory display 2255imm - i2c memory modify (auto-incrementing) 2256inm - i2c memory modify (constant address) 2257imw - i2c memory write (fill) 2258icrc32 - i2c checksum calculation 2259iprobe - probe to discover valid I2C chip addresses 2260iloop - infinite loop on address range 2261isdram - print SDRAM configuration information 2262sspi - SPI utility commands 2263base - print or set address offset 2264printenv- print environment variables 2265setenv - set environment variables 2266saveenv - save environment variables to persistent storage 2267protect - enable or disable FLASH write protection 2268erase - erase FLASH memory 2269flinfo - print FLASH memory information 2270bdinfo - print Board Info structure 2271iminfo - print header information for application image 2272coninfo - print console devices and informations 2273ide - IDE sub-system 2274loop - infinite loop on address range 2275loopw - infinite write loop on address range 2276mtest - simple RAM test 2277icache - enable or disable instruction cache 2278dcache - enable or disable data cache 2279reset - Perform RESET of the CPU 2280echo - echo args to console 2281version - print monitor version 2282help - print online help 2283? - alias for 'help' 2284 2285 2286Monitor Commands - Detailed Description: 2287======================================== 2288 2289TODO. 2290 2291For now: just type "help <command>". 2292 2293 2294Environment Variables: 2295====================== 2296 2297U-Boot supports user configuration using Environment Variables which 2298can be made persistent by saving to Flash memory. 2299 2300Environment Variables are set using "setenv", printed using 2301"printenv", and saved to Flash using "saveenv". Using "setenv" 2302without a value can be used to delete a variable from the 2303environment. As long as you don't save the environment you are 2304working with an in-memory copy. In case the Flash area containing the 2305environment is erased by accident, a default environment is provided. 2306 2307Some configuration options can be set using Environment Variables: 2308 2309 baudrate - see CONFIG_BAUDRATE 2310 2311 bootdelay - see CONFIG_BOOTDELAY 2312 2313 bootcmd - see CONFIG_BOOTCOMMAND 2314 2315 bootargs - Boot arguments when booting an RTOS image 2316 2317 bootfile - Name of the image to load with TFTP 2318 2319 autoload - if set to "no" (any string beginning with 'n'), 2320 "bootp" will just load perform a lookup of the 2321 configuration from the BOOTP server, but not try to 2322 load any image using TFTP 2323 2324 autostart - if set to "yes", an image loaded using the "bootp", 2325 "rarpboot", "tftpboot" or "diskboot" commands will 2326 be automatically started (by internally calling 2327 "bootm") 2328 2329 If set to "no", a standalone image passed to the 2330 "bootm" command will be copied to the load address 2331 (and eventually uncompressed), but NOT be started. 2332 This can be used to load and uncompress arbitrary 2333 data. 2334 2335 i2cfast - (PPC405GP|PPC405EP only) 2336 if set to 'y' configures Linux I2C driver for fast 2337 mode (400kHZ). This environment variable is used in 2338 initialization code. So, for changes to be effective 2339 it must be saved and board must be reset. 2340 2341 initrd_high - restrict positioning of initrd images: 2342 If this variable is not set, initrd images will be 2343 copied to the highest possible address in RAM; this 2344 is usually what you want since it allows for 2345 maximum initrd size. If for some reason you want to 2346 make sure that the initrd image is loaded below the 2347 CFG_BOOTMAPSZ limit, you can set this environment 2348 variable to a value of "no" or "off" or "0". 2349 Alternatively, you can set it to a maximum upper 2350 address to use (U-Boot will still check that it 2351 does not overwrite the U-Boot stack and data). 2352 2353 For instance, when you have a system with 16 MB 2354 RAM, and want to reserve 4 MB from use by Linux, 2355 you can do this by adding "mem=12M" to the value of 2356 the "bootargs" variable. However, now you must make 2357 sure that the initrd image is placed in the first 2358 12 MB as well - this can be done with 2359 2360 setenv initrd_high 00c00000 2361 2362 If you set initrd_high to 0xFFFFFFFF, this is an 2363 indication to U-Boot that all addresses are legal 2364 for the Linux kernel, including addresses in flash 2365 memory. In this case U-Boot will NOT COPY the 2366 ramdisk at all. This may be useful to reduce the 2367 boot time on your system, but requires that this 2368 feature is supported by your Linux kernel. 2369 2370 ipaddr - IP address; needed for tftpboot command 2371 2372 loadaddr - Default load address for commands like "bootp", 2373 "rarpboot", "tftpboot", "loadb" or "diskboot" 2374 2375 loads_echo - see CONFIG_LOADS_ECHO 2376 2377 serverip - TFTP server IP address; needed for tftpboot command 2378 2379 bootretry - see CONFIG_BOOT_RETRY_TIME 2380 2381 bootdelaykey - see CONFIG_AUTOBOOT_DELAY_STR 2382 2383 bootstopkey - see CONFIG_AUTOBOOT_STOP_STR 2384 2385 ethprime - When CONFIG_NET_MULTI is enabled controls which 2386 interface is used first. 2387 2388 ethact - When CONFIG_NET_MULTI is enabled controls which 2389 interface is currently active. For example you 2390 can do the following 2391 2392 => setenv ethact FEC ETHERNET 2393 => ping 192.168.0.1 # traffic sent on FEC ETHERNET 2394 => setenv ethact SCC ETHERNET 2395 => ping 10.0.0.1 # traffic sent on SCC ETHERNET 2396 2397 netretry - When set to "no" each network operation will 2398 either succeed or fail without retrying. 2399 When set to "once" the network operation will 2400 fail when all the available network interfaces 2401 are tried once without success. 2402 Useful on scripts which control the retry operation 2403 themselves. 2404 2405 vlan - When set to a value < 4095 the traffic over 2406 ethernet is encapsulated/received over 802.1q 2407 VLAN tagged frames. 2408 2409The following environment variables may be used and automatically 2410updated by the network boot commands ("bootp" and "rarpboot"), 2411depending the information provided by your boot server: 2412 2413 bootfile - see above 2414 dnsip - IP address of your Domain Name Server 2415 dnsip2 - IP address of your secondary Domain Name Server 2416 gatewayip - IP address of the Gateway (Router) to use 2417 hostname - Target hostname 2418 ipaddr - see above 2419 netmask - Subnet Mask 2420 rootpath - Pathname of the root filesystem on the NFS server 2421 serverip - see above 2422 2423 2424There are two special Environment Variables: 2425 2426 serial# - contains hardware identification information such 2427 as type string and/or serial number 2428 ethaddr - Ethernet address 2429 2430These variables can be set only once (usually during manufacturing of 2431the board). U-Boot refuses to delete or overwrite these variables 2432once they have been set once. 2433 2434 2435Further special Environment Variables: 2436 2437 ver - Contains the U-Boot version string as printed 2438 with the "version" command. This variable is 2439 readonly (see CONFIG_VERSION_VARIABLE). 2440 2441 2442Please note that changes to some configuration parameters may take 2443only effect after the next boot (yes, that's just like Windoze :-). 2444 2445 2446Command Line Parsing: 2447===================== 2448 2449There are two different command line parsers available with U-Boot: 2450the old "simple" one, and the much more powerful "hush" shell: 2451 2452Old, simple command line parser: 2453-------------------------------- 2454 2455- supports environment variables (through setenv / saveenv commands) 2456- several commands on one line, separated by ';' 2457- variable substitution using "... $(name) ..." syntax 2458- special characters ('$', ';') can be escaped by prefixing with '\', 2459 for example: 2460 setenv bootcmd bootm \$(address) 2461- You can also escape text by enclosing in single apostrophes, for example: 2462 setenv addip 'setenv bootargs $bootargs ip=$ipaddr:$serverip:$gatewayip:$netmask:$hostname::off' 2463 2464Hush shell: 2465----------- 2466 2467- similar to Bourne shell, with control structures like 2468 if...then...else...fi, for...do...done; while...do...done, 2469 until...do...done, ... 2470- supports environment ("global") variables (through setenv / saveenv 2471 commands) and local shell variables (through standard shell syntax 2472 "name=value"); only environment variables can be used with "run" 2473 command 2474 2475General rules: 2476-------------- 2477 2478(1) If a command line (or an environment variable executed by a "run" 2479 command) contains several commands separated by semicolon, and 2480 one of these commands fails, then the remaining commands will be 2481 executed anyway. 2482 2483(2) If you execute several variables with one call to run (i. e. 2484 calling run with a list af variables as arguments), any failing 2485 command will cause "run" to terminate, i. e. the remaining 2486 variables are not executed. 2487 2488Note for Redundant Ethernet Interfaces: 2489======================================= 2490 2491Some boards come with redundant ethernet interfaces; U-Boot supports 2492such configurations and is capable of automatic selection of a 2493"working" interface when needed. MAC assignment works as follows: 2494 2495Network interfaces are numbered eth0, eth1, eth2, ... Corresponding 2496MAC addresses can be stored in the environment as "ethaddr" (=>eth0), 2497"eth1addr" (=>eth1), "eth2addr", ... 2498 2499If the network interface stores some valid MAC address (for instance 2500in SROM), this is used as default address if there is NO correspon- 2501ding setting in the environment; if the corresponding environment 2502variable is set, this overrides the settings in the card; that means: 2503 2504o If the SROM has a valid MAC address, and there is no address in the 2505 environment, the SROM's address is used. 2506 2507o If there is no valid address in the SROM, and a definition in the 2508 environment exists, then the value from the environment variable is 2509 used. 2510 2511o If both the SROM and the environment contain a MAC address, and 2512 both addresses are the same, this MAC address is used. 2513 2514o If both the SROM and the environment contain a MAC address, and the 2515 addresses differ, the value from the environment is used and a 2516 warning is printed. 2517 2518o If neither SROM nor the environment contain a MAC address, an error 2519 is raised. 2520 2521 2522Image Formats: 2523============== 2524 2525The "boot" commands of this monitor operate on "image" files which 2526can be basicly anything, preceeded by a special header; see the 2527definitions in include/image.h for details; basicly, the header 2528defines the following image properties: 2529 2530* Target Operating System (Provisions for OpenBSD, NetBSD, FreeBSD, 2531 4.4BSD, Linux, SVR4, Esix, Solaris, Irix, SCO, Dell, NCR, VxWorks, 2532 LynxOS, pSOS, QNX, RTEMS, ARTOS; 2533 Currently supported: Linux, NetBSD, VxWorks, QNX, RTEMS, ARTOS, LynxOS). 2534* Target CPU Architecture (Provisions for Alpha, ARM, Intel x86, 2535 IA64, MIPS, NIOS, PowerPC, IBM S390, SuperH, Sparc, Sparc 64 Bit; 2536 Currently supported: ARM, Intel x86, MIPS, NIOS, PowerPC). 2537* Compression Type (uncompressed, gzip, bzip2) 2538* Load Address 2539* Entry Point 2540* Image Name 2541* Image Timestamp 2542 2543The header is marked by a special Magic Number, and both the header 2544and the data portions of the image are secured against corruption by 2545CRC32 checksums. 2546 2547 2548Linux Support: 2549============== 2550 2551Although U-Boot should support any OS or standalone application 2552easily, the main focus has always been on Linux during the design of 2553U-Boot. 2554 2555U-Boot includes many features that so far have been part of some 2556special "boot loader" code within the Linux kernel. Also, any 2557"initrd" images to be used are no longer part of one big Linux image; 2558instead, kernel and "initrd" are separate images. This implementation 2559serves several purposes: 2560 2561- the same features can be used for other OS or standalone 2562 applications (for instance: using compressed images to reduce the 2563 Flash memory footprint) 2564 2565- it becomes much easier to port new Linux kernel versions because 2566 lots of low-level, hardware dependent stuff are done by U-Boot 2567 2568- the same Linux kernel image can now be used with different "initrd" 2569 images; of course this also means that different kernel images can 2570 be run with the same "initrd". This makes testing easier (you don't 2571 have to build a new "zImage.initrd" Linux image when you just 2572 change a file in your "initrd"). Also, a field-upgrade of the 2573 software is easier now. 2574 2575 2576Linux HOWTO: 2577============ 2578 2579Porting Linux to U-Boot based systems: 2580--------------------------------------- 2581 2582U-Boot cannot save you from doing all the necessary modifications to 2583configure the Linux device drivers for use with your target hardware 2584(no, we don't intend to provide a full virtual machine interface to 2585Linux :-). 2586 2587But now you can ignore ALL boot loader code (in arch/ppc/mbxboot). 2588 2589Just make sure your machine specific header file (for instance 2590include/asm-ppc/tqm8xx.h) includes the same definition of the Board 2591Information structure as we define in include/u-boot.h, and make 2592sure that your definition of IMAP_ADDR uses the same value as your 2593U-Boot configuration in CFG_IMMR. 2594 2595 2596Configuring the Linux kernel: 2597----------------------------- 2598 2599No specific requirements for U-Boot. Make sure you have some root 2600device (initial ramdisk, NFS) for your target system. 2601 2602 2603Building a Linux Image: 2604----------------------- 2605 2606With U-Boot, "normal" build targets like "zImage" or "bzImage" are 2607not used. If you use recent kernel source, a new build target 2608"uImage" will exist which automatically builds an image usable by 2609U-Boot. Most older kernels also have support for a "pImage" target, 2610which was introduced for our predecessor project PPCBoot and uses a 2611100% compatible format. 2612 2613Example: 2614 2615 make TQM850L_config 2616 make oldconfig 2617 make dep 2618 make uImage 2619 2620The "uImage" build target uses a special tool (in 'tools/mkimage') to 2621encapsulate a compressed Linux kernel image with header information, 2622CRC32 checksum etc. for use with U-Boot. This is what we are doing: 2623 2624* build a standard "vmlinux" kernel image (in ELF binary format): 2625 2626* convert the kernel into a raw binary image: 2627 2628 ${CROSS_COMPILE}-objcopy -O binary \ 2629 -R .note -R .comment \ 2630 -S vmlinux linux.bin 2631 2632* compress the binary image: 2633 2634 gzip -9 linux.bin 2635 2636* package compressed binary image for U-Boot: 2637 2638 mkimage -A ppc -O linux -T kernel -C gzip \ 2639 -a 0 -e 0 -n "Linux Kernel Image" \ 2640 -d linux.bin.gz uImage 2641 2642 2643The "mkimage" tool can also be used to create ramdisk images for use 2644with U-Boot, either separated from the Linux kernel image, or 2645combined into one file. "mkimage" encapsulates the images with a 64 2646byte header containing information about target architecture, 2647operating system, image type, compression method, entry points, time 2648stamp, CRC32 checksums, etc. 2649 2650"mkimage" can be called in two ways: to verify existing images and 2651print the header information, or to build new images. 2652 2653In the first form (with "-l" option) mkimage lists the information 2654contained in the header of an existing U-Boot image; this includes 2655checksum verification: 2656 2657 tools/mkimage -l image 2658 -l ==> list image header information 2659 2660The second form (with "-d" option) is used to build a U-Boot image 2661from a "data file" which is used as image payload: 2662 2663 tools/mkimage -A arch -O os -T type -C comp -a addr -e ep \ 2664 -n name -d data_file image 2665 -A ==> set architecture to 'arch' 2666 -O ==> set operating system to 'os' 2667 -T ==> set image type to 'type' 2668 -C ==> set compression type 'comp' 2669 -a ==> set load address to 'addr' (hex) 2670 -e ==> set entry point to 'ep' (hex) 2671 -n ==> set image name to 'name' 2672 -d ==> use image data from 'datafile' 2673 2674Right now, all Linux kernels for PowerPC systems use the same load 2675address (0x00000000), but the entry point address depends on the 2676kernel version: 2677 2678- 2.2.x kernels have the entry point at 0x0000000C, 2679- 2.3.x and later kernels have the entry point at 0x00000000. 2680 2681So a typical call to build a U-Boot image would read: 2682 2683 -> tools/mkimage -n '2.4.4 kernel for TQM850L' \ 2684 > -A ppc -O linux -T kernel -C gzip -a 0 -e 0 \ 2685 > -d /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/ppc/coffboot/vmlinux.gz \ 2686 > examples/uImage.TQM850L 2687 Image Name: 2.4.4 kernel for TQM850L 2688 Created: Wed Jul 19 02:34:59 2000 2689 Image Type: PowerPC Linux Kernel Image (gzip compressed) 2690 Data Size: 335725 Bytes = 327.86 kB = 0.32 MB 2691 Load Address: 0x00000000 2692 Entry Point: 0x00000000 2693 2694To verify the contents of the image (or check for corruption): 2695 2696 -> tools/mkimage -l examples/uImage.TQM850L 2697 Image Name: 2.4.4 kernel for TQM850L 2698 Created: Wed Jul 19 02:34:59 2000 2699 Image Type: PowerPC Linux Kernel Image (gzip compressed) 2700 Data Size: 335725 Bytes = 327.86 kB = 0.32 MB 2701 Load Address: 0x00000000 2702 Entry Point: 0x00000000 2703 2704NOTE: for embedded systems where boot time is critical you can trade 2705speed for memory and install an UNCOMPRESSED image instead: this 2706needs more space in Flash, but boots much faster since it does not 2707need to be uncompressed: 2708 2709 -> gunzip /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/ppc/coffboot/vmlinux.gz 2710 -> tools/mkimage -n '2.4.4 kernel for TQM850L' \ 2711 > -A ppc -O linux -T kernel -C none -a 0 -e 0 \ 2712 > -d /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/ppc/coffboot/vmlinux \ 2713 > examples/uImage.TQM850L-uncompressed 2714 Image Name: 2.4.4 kernel for TQM850L 2715 Created: Wed Jul 19 02:34:59 2000 2716 Image Type: PowerPC Linux Kernel Image (uncompressed) 2717 Data Size: 792160 Bytes = 773.59 kB = 0.76 MB 2718 Load Address: 0x00000000 2719 Entry Point: 0x00000000 2720 2721 2722Similar you can build U-Boot images from a 'ramdisk.image.gz' file 2723when your kernel is intended to use an initial ramdisk: 2724 2725 -> tools/mkimage -n 'Simple Ramdisk Image' \ 2726 > -A ppc -O linux -T ramdisk -C gzip \ 2727 > -d /LinuxPPC/images/SIMPLE-ramdisk.image.gz examples/simple-initrd 2728 Image Name: Simple Ramdisk Image 2729 Created: Wed Jan 12 14:01:50 2000 2730 Image Type: PowerPC Linux RAMDisk Image (gzip compressed) 2731 Data Size: 566530 Bytes = 553.25 kB = 0.54 MB 2732 Load Address: 0x00000000 2733 Entry Point: 0x00000000 2734 2735 2736Installing a Linux Image: 2737------------------------- 2738 2739To downloading a U-Boot image over the serial (console) interface, 2740you must convert the image to S-Record format: 2741 2742 objcopy -I binary -O srec examples/image examples/image.srec 2743 2744The 'objcopy' does not understand the information in the U-Boot 2745image header, so the resulting S-Record file will be relative to 2746address 0x00000000. To load it to a given address, you need to 2747specify the target address as 'offset' parameter with the 'loads' 2748command. 2749 2750Example: install the image to address 0x40100000 (which on the 2751TQM8xxL is in the first Flash bank): 2752 2753 => erase 40100000 401FFFFF 2754 2755 .......... done 2756 Erased 8 sectors 2757 2758 => loads 40100000 2759 ## Ready for S-Record download ... 2760 ~>examples/image.srec 2761 1 2 3 4 5 6 7 8 9 10 11 12 13 ... 2762 ... 2763 15989 15990 15991 15992 2764 [file transfer complete] 2765 [connected] 2766 ## Start Addr = 0x00000000 2767 2768 2769You can check the success of the download using the 'iminfo' command; 2770this includes a checksum verification so you can be sure no data 2771corruption happened: 2772 2773 => imi 40100000 2774 2775 ## Checking Image at 40100000 ... 2776 Image Name: 2.2.13 for initrd on TQM850L 2777 Image Type: PowerPC Linux Kernel Image (gzip compressed) 2778 Data Size: 335725 Bytes = 327 kB = 0 MB 2779 Load Address: 00000000 2780 Entry Point: 0000000c 2781 Verifying Checksum ... OK 2782 2783 2784Boot Linux: 2785----------- 2786 2787The "bootm" command is used to boot an application that is stored in 2788memory (RAM or Flash). In case of a Linux kernel image, the contents 2789of the "bootargs" environment variable is passed to the kernel as 2790parameters. You can check and modify this variable using the 2791"printenv" and "setenv" commands: 2792 2793 2794 => printenv bootargs 2795 bootargs=root=/dev/ram 2796 2797 => setenv bootargs root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2 2798 2799 => printenv bootargs 2800 bootargs=root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2 2801 2802 => bootm 40020000 2803 ## Booting Linux kernel at 40020000 ... 2804 Image Name: 2.2.13 for NFS on TQM850L 2805 Image Type: PowerPC Linux Kernel Image (gzip compressed) 2806 Data Size: 381681 Bytes = 372 kB = 0 MB 2807 Load Address: 00000000 2808 Entry Point: 0000000c 2809 Verifying Checksum ... OK 2810 Uncompressing Kernel Image ... OK 2811 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 2812 Boot arguments: root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2 2813 time_init: decrementer frequency = 187500000/60 2814 Calibrating delay loop... 49.77 BogoMIPS 2815 Memory: 15208k available (700k kernel code, 444k data, 32k init) [c0000000,c1000000] 2816 ... 2817 2818If you want to boot a Linux kernel with initial ram disk, you pass 2819the memory addresses of both the kernel and the initrd image (PPBCOOT 2820format!) to the "bootm" command: 2821 2822 => imi 40100000 40200000 2823 2824 ## Checking Image at 40100000 ... 2825 Image Name: 2.2.13 for initrd on TQM850L 2826 Image Type: PowerPC Linux Kernel Image (gzip compressed) 2827 Data Size: 335725 Bytes = 327 kB = 0 MB 2828 Load Address: 00000000 2829 Entry Point: 0000000c 2830 Verifying Checksum ... OK 2831 2832 ## Checking Image at 40200000 ... 2833 Image Name: Simple Ramdisk Image 2834 Image Type: PowerPC Linux RAMDisk Image (gzip compressed) 2835 Data Size: 566530 Bytes = 553 kB = 0 MB 2836 Load Address: 00000000 2837 Entry Point: 00000000 2838 Verifying Checksum ... OK 2839 2840 => bootm 40100000 40200000 2841 ## Booting Linux kernel at 40100000 ... 2842 Image Name: 2.2.13 for initrd on TQM850L 2843 Image Type: PowerPC Linux Kernel Image (gzip compressed) 2844 Data Size: 335725 Bytes = 327 kB = 0 MB 2845 Load Address: 00000000 2846 Entry Point: 0000000c 2847 Verifying Checksum ... OK 2848 Uncompressing Kernel Image ... OK 2849 ## Loading RAMDisk Image at 40200000 ... 2850 Image Name: Simple Ramdisk Image 2851 Image Type: PowerPC Linux RAMDisk Image (gzip compressed) 2852 Data Size: 566530 Bytes = 553 kB = 0 MB 2853 Load Address: 00000000 2854 Entry Point: 00000000 2855 Verifying Checksum ... OK 2856 Loading Ramdisk ... OK 2857 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 2858 Boot arguments: root=/dev/ram 2859 time_init: decrementer frequency = 187500000/60 2860 Calibrating delay loop... 49.77 BogoMIPS 2861 ... 2862 RAMDISK: Compressed image found at block 0 2863 VFS: Mounted root (ext2 filesystem). 2864 2865 bash# 2866 2867More About U-Boot Image Types: 2868------------------------------ 2869 2870U-Boot supports the following image types: 2871 2872 "Standalone Programs" are directly runnable in the environment 2873 provided by U-Boot; it is expected that (if they behave 2874 well) you can continue to work in U-Boot after return from 2875 the Standalone Program. 2876 "OS Kernel Images" are usually images of some Embedded OS which 2877 will take over control completely. Usually these programs 2878 will install their own set of exception handlers, device 2879 drivers, set up the MMU, etc. - this means, that you cannot 2880 expect to re-enter U-Boot except by resetting the CPU. 2881 "RAMDisk Images" are more or less just data blocks, and their 2882 parameters (address, size) are passed to an OS kernel that is 2883 being started. 2884 "Multi-File Images" contain several images, typically an OS 2885 (Linux) kernel image and one or more data images like 2886 RAMDisks. This construct is useful for instance when you want 2887 to boot over the network using BOOTP etc., where the boot 2888 server provides just a single image file, but you want to get 2889 for instance an OS kernel and a RAMDisk image. 2890 2891 "Multi-File Images" start with a list of image sizes, each 2892 image size (in bytes) specified by an "uint32_t" in network 2893 byte order. This list is terminated by an "(uint32_t)0". 2894 Immediately after the terminating 0 follow the images, one by 2895 one, all aligned on "uint32_t" boundaries (size rounded up to 2896 a multiple of 4 bytes). 2897 2898 "Firmware Images" are binary images containing firmware (like 2899 U-Boot or FPGA images) which usually will be programmed to 2900 flash memory. 2901 2902 "Script files" are command sequences that will be executed by 2903 U-Boot's command interpreter; this feature is especially 2904 useful when you configure U-Boot to use a real shell (hush) 2905 as command interpreter. 2906 2907 2908Standalone HOWTO: 2909================= 2910 2911One of the features of U-Boot is that you can dynamically load and 2912run "standalone" applications, which can use some resources of 2913U-Boot like console I/O functions or interrupt services. 2914 2915Two simple examples are included with the sources: 2916 2917"Hello World" Demo: 2918------------------- 2919 2920'examples/hello_world.c' contains a small "Hello World" Demo 2921application; it is automatically compiled when you build U-Boot. 2922It's configured to run at address 0x00040004, so you can play with it 2923like that: 2924 2925 => loads 2926 ## Ready for S-Record download ... 2927 ~>examples/hello_world.srec 2928 1 2 3 4 5 6 7 8 9 10 11 ... 2929 [file transfer complete] 2930 [connected] 2931 ## Start Addr = 0x00040004 2932 2933 => go 40004 Hello World! This is a test. 2934 ## Starting application at 0x00040004 ... 2935 Hello World 2936 argc = 7 2937 argv[0] = "40004" 2938 argv[1] = "Hello" 2939 argv[2] = "World!" 2940 argv[3] = "This" 2941 argv[4] = "is" 2942 argv[5] = "a" 2943 argv[6] = "test." 2944 argv[7] = "<NULL>" 2945 Hit any key to exit ... 2946 2947 ## Application terminated, rc = 0x0 2948 2949Another example, which demonstrates how to register a CPM interrupt 2950handler with the U-Boot code, can be found in 'examples/timer.c'. 2951Here, a CPM timer is set up to generate an interrupt every second. 2952The interrupt service routine is trivial, just printing a '.' 2953character, but this is just a demo program. The application can be 2954controlled by the following keys: 2955 2956 ? - print current values og the CPM Timer registers 2957 b - enable interrupts and start timer 2958 e - stop timer and disable interrupts 2959 q - quit application 2960 2961 => loads 2962 ## Ready for S-Record download ... 2963 ~>examples/timer.srec 2964 1 2 3 4 5 6 7 8 9 10 11 ... 2965 [file transfer complete] 2966 [connected] 2967 ## Start Addr = 0x00040004 2968 2969 => go 40004 2970 ## Starting application at 0x00040004 ... 2971 TIMERS=0xfff00980 2972 Using timer 1 2973 tgcr @ 0xfff00980, tmr @ 0xfff00990, trr @ 0xfff00994, tcr @ 0xfff00998, tcn @ 0xfff0099c, ter @ 0xfff009b0 2974 2975Hit 'b': 2976 [q, b, e, ?] Set interval 1000000 us 2977 Enabling timer 2978Hit '?': 2979 [q, b, e, ?] ........ 2980 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0xef6, ter=0x0 2981Hit '?': 2982 [q, b, e, ?] . 2983 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x2ad4, ter=0x0 2984Hit '?': 2985 [q, b, e, ?] . 2986 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x1efc, ter=0x0 2987Hit '?': 2988 [q, b, e, ?] . 2989 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x169d, ter=0x0 2990Hit 'e': 2991 [q, b, e, ?] ...Stopping timer 2992Hit 'q': 2993 [q, b, e, ?] ## Application terminated, rc = 0x0 2994 2995 2996Minicom warning: 2997================ 2998 2999Over time, many people have reported problems when trying to use the 3000"minicom" terminal emulation program for serial download. I (wd) 3001consider minicom to be broken, and recommend not to use it. Under 3002Unix, I recommend to use C-Kermit for general purpose use (and 3003especially for kermit binary protocol download ("loadb" command), and 3004use "cu" for S-Record download ("loads" command). 3005 3006Nevertheless, if you absolutely want to use it try adding this 3007configuration to your "File transfer protocols" section: 3008 3009 Name Program Name U/D FullScr IO-Red. Multi 3010 X kermit /usr/bin/kermit -i -l %l -s Y U Y N N 3011 Y kermit /usr/bin/kermit -i -l %l -r N D Y N N 3012 3013 3014NetBSD Notes: 3015============= 3016 3017Starting at version 0.9.2, U-Boot supports NetBSD both as host 3018(build U-Boot) and target system (boots NetBSD/mpc8xx). 3019 3020Building requires a cross environment; it is known to work on 3021NetBSD/i386 with the cross-powerpc-netbsd-1.3 package (you will also 3022need gmake since the Makefiles are not compatible with BSD make). 3023Note that the cross-powerpc package does not install include files; 3024attempting to build U-Boot will fail because <machine/ansi.h> is 3025missing. This file has to be installed and patched manually: 3026 3027 # cd /usr/pkg/cross/powerpc-netbsd/include 3028 # mkdir powerpc 3029 # ln -s powerpc machine 3030 # cp /usr/src/sys/arch/powerpc/include/ansi.h powerpc/ansi.h 3031 # ${EDIT} powerpc/ansi.h ## must remove __va_list, _BSD_VA_LIST 3032 3033Native builds *don't* work due to incompatibilities between native 3034and U-Boot include files. 3035 3036Booting assumes that (the first part of) the image booted is a 3037stage-2 loader which in turn loads and then invokes the kernel 3038proper. Loader sources will eventually appear in the NetBSD source 3039tree (probably in sys/arc/mpc8xx/stand/u-boot_stage2/); in the 3040meantime, send mail to bruno@exet-ag.de and/or wd@denx.de for 3041details. 3042 3043 3044Implementation Internals: 3045========================= 3046 3047The following is not intended to be a complete description of every 3048implementation detail. However, it should help to understand the 3049inner workings of U-Boot and make it easier to port it to custom 3050hardware. 3051 3052 3053Initial Stack, Global Data: 3054--------------------------- 3055 3056The implementation of U-Boot is complicated by the fact that U-Boot 3057starts running out of ROM (flash memory), usually without access to 3058system RAM (because the memory controller is not initialized yet). 3059This means that we don't have writable Data or BSS segments, and BSS 3060is not initialized as zero. To be able to get a C environment working 3061at all, we have to allocate at least a minimal stack. Implementation 3062options for this are defined and restricted by the CPU used: Some CPU 3063models provide on-chip memory (like the IMMR area on MPC8xx and 3064MPC826x processors), on others (parts of) the data cache can be 3065locked as (mis-) used as memory, etc. 3066 3067 Chris Hallinan posted a good summary of these issues to the 3068 u-boot-users mailing list: 3069 3070 Subject: RE: [U-Boot-Users] RE: More On Memory Bank x (nothingness)? 3071 From: "Chris Hallinan" <clh@net1plus.com> 3072 Date: Mon, 10 Feb 2003 16:43:46 -0500 (22:43 MET) 3073 ... 3074 3075 Correct me if I'm wrong, folks, but the way I understand it 3076 is this: Using DCACHE as initial RAM for Stack, etc, does not 3077 require any physical RAM backing up the cache. The cleverness 3078 is that the cache is being used as a temporary supply of 3079 necessary storage before the SDRAM controller is setup. It's 3080 beyond the scope of this list to expain the details, but you 3081 can see how this works by studying the cache architecture and 3082 operation in the architecture and processor-specific manuals. 3083 3084 OCM is On Chip Memory, which I believe the 405GP has 4K. It 3085 is another option for the system designer to use as an 3086 initial stack/ram area prior to SDRAM being available. Either 3087 option should work for you. Using CS 4 should be fine if your 3088 board designers haven't used it for something that would 3089 cause you grief during the initial boot! It is frequently not 3090 used. 3091 3092 CFG_INIT_RAM_ADDR should be somewhere that won't interfere 3093 with your processor/board/system design. The default value 3094 you will find in any recent u-boot distribution in 3095 Walnut405.h should work for you. I'd set it to a value larger 3096 than your SDRAM module. If you have a 64MB SDRAM module, set 3097 it above 400_0000. Just make sure your board has no resources 3098 that are supposed to respond to that address! That code in 3099 start.S has been around a while and should work as is when 3100 you get the config right. 3101 3102 -Chris Hallinan 3103 DS4.COM, Inc. 3104 3105It is essential to remember this, since it has some impact on the C 3106code for the initialization procedures: 3107 3108* Initialized global data (data segment) is read-only. Do not attempt 3109 to write it. 3110 3111* Do not use any unitialized global data (or implicitely initialized 3112 as zero data - BSS segment) at all - this is undefined, initiali- 3113 zation is performed later (when relocating to RAM). 3114 3115* Stack space is very limited. Avoid big data buffers or things like 3116 that. 3117 3118Having only the stack as writable memory limits means we cannot use 3119normal global data to share information beween the code. But it 3120turned out that the implementation of U-Boot can be greatly 3121simplified by making a global data structure (gd_t) available to all 3122functions. We could pass a pointer to this data as argument to _all_ 3123functions, but this would bloat the code. Instead we use a feature of 3124the GCC compiler (Global Register Variables) to share the data: we 3125place a pointer (gd) to the global data into a register which we 3126reserve for this purpose. 3127 3128When choosing a register for such a purpose we are restricted by the 3129relevant (E)ABI specifications for the current architecture, and by 3130GCC's implementation. 3131 3132For PowerPC, the following registers have specific use: 3133 R1: stack pointer 3134 R2: TOC pointer 3135 R3-R4: parameter passing and return values 3136 R5-R10: parameter passing 3137 R13: small data area pointer 3138 R30: GOT pointer 3139 R31: frame pointer 3140 3141 (U-Boot also uses R14 as internal GOT pointer.) 3142 3143 ==> U-Boot will use R29 to hold a pointer to the global data 3144 3145 Note: on PPC, we could use a static initializer (since the 3146 address of the global data structure is known at compile time), 3147 but it turned out that reserving a register results in somewhat 3148 smaller code - although the code savings are not that big (on 3149 average for all boards 752 bytes for the whole U-Boot image, 3150 624 text + 127 data). 3151 3152On ARM, the following registers are used: 3153 3154 R0: function argument word/integer result 3155 R1-R3: function argument word 3156 R9: GOT pointer 3157 R10: stack limit (used only if stack checking if enabled) 3158 R11: argument (frame) pointer 3159 R12: temporary workspace 3160 R13: stack pointer 3161 R14: link register 3162 R15: program counter 3163 3164 ==> U-Boot will use R8 to hold a pointer to the global data 3165 3166 3167Memory Management: 3168------------------ 3169 3170U-Boot runs in system state and uses physical addresses, i.e. the 3171MMU is not used either for address mapping nor for memory protection. 3172 3173The available memory is mapped to fixed addresses using the memory 3174controller. In this process, a contiguous block is formed for each 3175memory type (Flash, SDRAM, SRAM), even when it consists of several 3176physical memory banks. 3177 3178U-Boot is installed in the first 128 kB of the first Flash bank (on 3179TQM8xxL modules this is the range 0x40000000 ... 0x4001FFFF). After 3180booting and sizing and initializing DRAM, the code relocates itself 3181to the upper end of DRAM. Immediately below the U-Boot code some 3182memory is reserved for use by malloc() [see CFG_MALLOC_LEN 3183configuration setting]. Below that, a structure with global Board 3184Info data is placed, followed by the stack (growing downward). 3185 3186Additionally, some exception handler code is copied to the low 8 kB 3187of DRAM (0x00000000 ... 0x00001FFF). 3188 3189So a typical memory configuration with 16 MB of DRAM could look like 3190this: 3191 3192 0x0000 0000 Exception Vector code 3193 : 3194 0x0000 1FFF 3195 0x0000 2000 Free for Application Use 3196 : 3197 : 3198 3199 : 3200 : 3201 0x00FB FF20 Monitor Stack (Growing downward) 3202 0x00FB FFAC Board Info Data and permanent copy of global data 3203 0x00FC 0000 Malloc Arena 3204 : 3205 0x00FD FFFF 3206 0x00FE 0000 RAM Copy of Monitor Code 3207 ... eventually: LCD or video framebuffer 3208 ... eventually: pRAM (Protected RAM - unchanged by reset) 3209 0x00FF FFFF [End of RAM] 3210 3211 3212System Initialization: 3213---------------------- 3214 3215In the reset configuration, U-Boot starts at the reset entry point 3216(on most PowerPC systens at address 0x00000100). Because of the reset 3217configuration for CS0# this is a mirror of the onboard Flash memory. 3218To be able to re-map memory U-Boot then jumps to its link address. 3219To be able to implement the initialization code in C, a (small!) 3220initial stack is set up in the internal Dual Ported RAM (in case CPUs 3221which provide such a feature like MPC8xx or MPC8260), or in a locked 3222part of the data cache. After that, U-Boot initializes the CPU core, 3223the caches and the SIU. 3224 3225Next, all (potentially) available memory banks are mapped using a 3226preliminary mapping. For example, we put them on 512 MB boundaries 3227(multiples of 0x20000000: SDRAM on 0x00000000 and 0x20000000, Flash 3228on 0x40000000 and 0x60000000, SRAM on 0x80000000). Then UPM A is 3229programmed for SDRAM access. Using the temporary configuration, a 3230simple memory test is run that determines the size of the SDRAM 3231banks. 3232 3233When there is more than one SDRAM bank, and the banks are of 3234different size, the largest is mapped first. For equal size, the first 3235bank (CS2#) is mapped first. The first mapping is always for address 32360x00000000, with any additional banks following immediately to create 3237contiguous memory starting from 0. 3238 3239Then, the monitor installs itself at the upper end of the SDRAM area 3240and allocates memory for use by malloc() and for the global Board 3241Info data; also, the exception vector code is copied to the low RAM 3242pages, and the final stack is set up. 3243 3244Only after this relocation will you have a "normal" C environment; 3245until that you are restricted in several ways, mostly because you are 3246running from ROM, and because the code will have to be relocated to a 3247new address in RAM. 3248 3249 3250U-Boot Porting Guide: 3251---------------------- 3252 3253[Based on messages by Jerry Van Baren in the U-Boot-Users mailing 3254list, October 2002] 3255 3256 3257int main (int argc, char *argv[]) 3258{ 3259 sighandler_t no_more_time; 3260 3261 signal (SIGALRM, no_more_time); 3262 alarm (PROJECT_DEADLINE - toSec (3 * WEEK)); 3263 3264 if (available_money > available_manpower) { 3265 pay consultant to port U-Boot; 3266 return 0; 3267 } 3268 3269 Download latest U-Boot source; 3270 3271 Subscribe to u-boot-users mailing list; 3272 3273 if (clueless) { 3274 email ("Hi, I am new to U-Boot, how do I get started?"); 3275 } 3276 3277 while (learning) { 3278 Read the README file in the top level directory; 3279 Read http://www.denx.de/twiki/bin/view/DULG/Manual ; 3280 Read the source, Luke; 3281 } 3282 3283 if (available_money > toLocalCurrency ($2500)) { 3284 Buy a BDI2000; 3285 } else { 3286 Add a lot of aggravation and time; 3287 } 3288 3289 Create your own board support subdirectory; 3290 3291 Create your own board config file; 3292 3293 while (!running) { 3294 do { 3295 Add / modify source code; 3296 } until (compiles); 3297 Debug; 3298 if (clueless) 3299 email ("Hi, I am having problems..."); 3300 } 3301 Send patch file to Wolfgang; 3302 3303 return 0; 3304} 3305 3306void no_more_time (int sig) 3307{ 3308 hire_a_guru(); 3309} 3310 3311 3312Coding Standards: 3313----------------- 3314 3315All contributions to U-Boot should conform to the Linux kernel 3316coding style; see the file "Documentation/CodingStyle" in your Linux 3317kernel source directory. 3318 3319Please note that U-Boot is implemented in C (and to some small parts 3320in Assembler); no C++ is used, so please do not use C++ style 3321comments (//) in your code. 3322 3323Please also stick to the following formatting rules: 3324- remove any trailing white space 3325- use TAB characters for indentation, not spaces 3326- make sure NOT to use DOS '\r\n' line feeds 3327- do not add more than 2 empty lines to source files 3328- do not add trailing empty lines to source files 3329 3330Submissions which do not conform to the standards may be returned 3331with a request to reformat the changes. 3332 3333 3334Submitting Patches: 3335------------------- 3336 3337Since the number of patches for U-Boot is growing, we need to 3338establish some rules. Submissions which do not conform to these rules 3339may be rejected, even when they contain important and valuable stuff. 3340 3341 3342When you send a patch, please include the following information with 3343it: 3344 3345* For bug fixes: a description of the bug and how your patch fixes 3346 this bug. Please try to include a way of demonstrating that the 3347 patch actually fixes something. 3348 3349* For new features: a description of the feature and your 3350 implementation. 3351 3352* A CHANGELOG entry as plaintext (separate from the patch) 3353 3354* For major contributions, your entry to the CREDITS file 3355 3356* When you add support for a new board, don't forget to add this 3357 board to the MAKEALL script, too. 3358 3359* If your patch adds new configuration options, don't forget to 3360 document these in the README file. 3361 3362* The patch itself. If you are accessing the CVS repository use "cvs 3363 update; cvs diff -puRN"; else, use "diff -purN OLD NEW". If your 3364 version of diff does not support these options, then get the latest 3365 version of GNU diff. 3366 3367 The current directory when running this command shall be the top 3368 level directory of the U-Boot source tree, or it's parent directory 3369 (i. e. please make sure that your patch includes sufficient 3370 directory information for the affected files). 3371 3372 We accept patches as plain text, MIME attachments or as uuencoded 3373 gzipped text. 3374 3375* If one logical set of modifications affects or creates several 3376 files, all these changes shall be submitted in a SINGLE patch file. 3377 3378* Changesets that contain different, unrelated modifications shall be 3379 submitted as SEPARATE patches, one patch per changeset. 3380 3381 3382Notes: 3383 3384* Before sending the patch, run the MAKEALL script on your patched 3385 source tree and make sure that no errors or warnings are reported 3386 for any of the boards. 3387 3388* Keep your modifications to the necessary minimum: A patch 3389 containing several unrelated changes or arbitrary reformats will be 3390 returned with a request to re-formatting / split it. 3391 3392* If you modify existing code, make sure that your new code does not 3393 add to the memory footprint of the code ;-) Small is beautiful! 3394 When adding new features, these should compile conditionally only 3395 (using #ifdef), and the resulting code with the new feature 3396 disabled must not need more memory than the old code without your 3397 modification. 3398