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, ARM, MIPS and several other 29processors, which can be installed in a boot ROM and used to 30initialize and test the hardware or to download and run application 31code. 32 33The development of U-Boot is closely related to Linux: some parts of 34the source code originate in the Linux source tree, we have some 35header files in common, and special provision has been made to 36support booting of Linux images. 37 38Some attention has been paid to make this software easily 39configurable and extendable. For instance, all monitor commands are 40implemented with the same call interface, so that it's very easy to 41add new commands. Also, instead of permanently adding rarely used 42code (for instance hardware test utilities) to the monitor, you can 43load and run it dynamically. 44 45 46Status: 47======= 48 49In general, all boards for which a configuration option exists in the 50Makefile have been tested to some extent and can be considered 51"working". In fact, many of them are used in production systems. 52 53In case of problems see the CHANGELOG and CREDITS files to find out 54who contributed the specific port. 55 56 57Where to get help: 58================== 59 60In case you have questions about, problems with or contributions for 61U-Boot you should send a message to the U-Boot mailing list at 62<u-boot-users@lists.sourceforge.net>. There is also an archive of 63previous traffic on the mailing list - please search the archive 64before asking FAQ's. Please see 65http://lists.sourceforge.net/lists/listinfo/u-boot-users/ 66 67 68Where we come from: 69=================== 70 71- start from 8xxrom sources 72- create PPCBoot project (http://sourceforge.net/projects/ppcboot) 73- clean up code 74- make it easier to add custom boards 75- make it possible to add other [PowerPC] CPUs 76- extend functions, especially: 77 * Provide extended interface to Linux boot loader 78 * S-Record download 79 * network boot 80 * PCMCIA / CompactFLash / ATA disk / SCSI ... boot 81- create ARMBoot project (http://sourceforge.net/projects/armboot) 82- add other CPU families (starting with ARM) 83- create U-Boot project (http://sourceforge.net/projects/u-boot) 84 85 86Names and Spelling: 87=================== 88 89The "official" name of this project is "Das U-Boot". The spelling 90"U-Boot" shall be used in all written text (documentation, comments 91in source files etc.). Example: 92 93 This is the README file for the U-Boot project. 94 95File names etc. shall be based on the string "u-boot". Examples: 96 97 include/asm-ppc/u-boot.h 98 99 #include <asm/u-boot.h> 100 101Variable names, preprocessor constants etc. shall be either based on 102the string "u_boot" or on "U_BOOT". Example: 103 104 U_BOOT_VERSION u_boot_logo 105 IH_OS_U_BOOT u_boot_hush_start 106 107 108Versioning: 109=========== 110 111U-Boot uses a 3 level version number containing a version, a 112sub-version, and a patchlevel: "U-Boot-2.34.5" means version "2", 113sub-version "34", and patchlevel "4". 114 115The patchlevel is used to indicate certain stages of development 116between released versions, i. e. officially released versions of 117U-Boot will always have a patchlevel of "0". 118 119 120Directory Hierarchy: 121==================== 122 123- board Board dependent files 124- common Misc architecture independent functions 125- cpu CPU specific files 126 - 74xx_7xx Files specific to Motorola MPC74xx and 7xx CPUs 127 - arm720t Files specific to ARM 720 CPUs 128 - arm920t Files specific to ARM 920 CPUs 129 - imx Files specific to Motorola MC9328 i.MX CPUs 130 - s3c24x0 Files specific to Samsung S3C24X0 CPUs 131 - arm925t Files specific to ARM 925 CPUs 132 - arm926ejs Files specific to ARM 926 CPUs 133 - at91rm9200 Files specific to Atmel AT91RM9200 CPUs 134 - i386 Files specific to i386 CPUs 135 - ixp Files specific to Intel XScale IXP CPUs 136 - mcf52x2 Files specific to Motorola ColdFire MCF52x2 CPUs 137 - mips Files specific to MIPS CPUs 138 - mpc5xx Files specific to Motorola MPC5xx CPUs 139 - mpc5xxx Files specific to Motorola MPC5xxx CPUs 140 - mpc8xx Files specific to Motorola MPC8xx CPUs 141 - mpc824x Files specific to Motorola MPC824x CPUs 142 - mpc8260 Files specific to Motorola MPC8260 CPUs 143 - mpc85xx Files specific to Motorola MPC85xx CPUs 144 - nios Files specific to Altera NIOS CPUs 145 - nios2 Files specific to Altera Nios-II CPUs 146 - ppc4xx Files specific to IBM PowerPC 4xx CPUs 147 - pxa Files specific to Intel XScale PXA CPUs 148 - s3c44b0 Files specific to Samsung S3C44B0 CPUs 149 - sa1100 Files specific to Intel StrongARM SA1100 CPUs 150- disk Code for disk drive partition handling 151- doc Documentation (don't expect too much) 152- drivers Commonly used device drivers 153- dtt Digital Thermometer and Thermostat drivers 154- examples Example code for standalone applications, etc. 155- include Header Files 156- lib_arm Files generic to ARM architecture 157- lib_generic Files generic to all architectures 158- lib_i386 Files generic to i386 architecture 159- lib_m68k Files generic to m68k architecture 160- lib_mips Files generic to MIPS architecture 161- lib_nios Files generic to NIOS architecture 162- lib_ppc Files generic to PowerPC architecture 163- net Networking code 164- post Power On Self Test 165- rtc Real Time Clock drivers 166- tools Tools to build S-Record or U-Boot images, etc. 167 168Software Configuration: 169======================= 170 171Configuration is usually done using C preprocessor defines; the 172rationale behind that is to avoid dead code whenever possible. 173 174There are two classes of configuration variables: 175 176* Configuration _OPTIONS_: 177 These are selectable by the user and have names beginning with 178 "CONFIG_". 179 180* Configuration _SETTINGS_: 181 These depend on the hardware etc. and should not be meddled with if 182 you don't know what you're doing; they have names beginning with 183 "CFG_". 184 185Later we will add a configuration tool - probably similar to or even 186identical to what's used for the Linux kernel. Right now, we have to 187do the configuration by hand, which means creating some symbolic 188links and editing some configuration files. We use the TQM8xxL boards 189as an example here. 190 191 192Selection of Processor Architecture and Board Type: 193--------------------------------------------------- 194 195For all supported boards there are ready-to-use default 196configurations available; just type "make <board_name>_config". 197 198Example: For a TQM823L module type: 199 200 cd u-boot 201 make TQM823L_config 202 203For the Cogent platform, you need to specify the cpu type as well; 204e.g. "make cogent_mpc8xx_config". And also configure the cogent 205directory according to the instructions in cogent/README. 206 207 208Configuration Options: 209---------------------- 210 211Configuration depends on the combination of board and CPU type; all 212such information is kept in a configuration file 213"include/configs/<board_name>.h". 214 215Example: For a TQM823L module, all configuration settings are in 216"include/configs/TQM823L.h". 217 218 219Many of the options are named exactly as the corresponding Linux 220kernel configuration options. The intention is to make it easier to 221build a config tool - later. 222 223 224The following options need to be configured: 225 226- CPU Type: Define exactly one of 227 228 PowerPC based CPUs: 229 ------------------- 230 CONFIG_MPC823, CONFIG_MPC850, CONFIG_MPC855, CONFIG_MPC860 231 or CONFIG_MPC5xx 232 or CONFIG_MPC824X, CONFIG_MPC8260 233 or CONFIG_MPC85xx 234 or CONFIG_IOP480 235 or CONFIG_405GP 236 or CONFIG_405EP 237 or CONFIG_440 238 or CONFIG_MPC74xx 239 or CONFIG_750FX 240 241 ARM based CPUs: 242 --------------- 243 CONFIG_SA1110 244 CONFIG_ARM7 245 CONFIG_PXA250 246 247 MicroBlaze based CPUs: 248 ---------------------- 249 CONFIG_MICROBLAZE 250 251 Nios-2 based CPUs: 252 ---------------------- 253 CONFIG_NIOS2 254 255 256- Board Type: Define exactly one of 257 258 PowerPC based boards: 259 --------------------- 260 261 CONFIG_ADCIOP CONFIG_GEN860T CONFIG_PCI405 262 CONFIG_ADS860 CONFIG_GENIETV CONFIG_PCIPPC2 263 CONFIG_AMX860 CONFIG_GTH CONFIG_PCIPPC6 264 CONFIG_AR405 CONFIG_gw8260 CONFIG_pcu_e 265 CONFIG_BAB7xx CONFIG_hermes CONFIG_PIP405 266 CONFIG_c2mon CONFIG_hymod CONFIG_PM826 267 CONFIG_CANBT CONFIG_IAD210 CONFIG_ppmc8260 268 CONFIG_CCM CONFIG_ICU862 CONFIG_QS823 269 CONFIG_CMI CONFIG_IP860 CONFIG_QS850 270 CONFIG_cogent_mpc8260 CONFIG_IPHASE4539 CONFIG_QS860T 271 CONFIG_cogent_mpc8xx CONFIG_IVML24 CONFIG_RBC823 272 CONFIG_CPCI405 CONFIG_IVML24_128 CONFIG_RPXClassic 273 CONFIG_CPCI4052 CONFIG_IVML24_256 CONFIG_RPXlite 274 CONFIG_CPCIISER4 CONFIG_IVMS8 CONFIG_RPXsuper 275 CONFIG_CPU86 CONFIG_IVMS8_128 CONFIG_rsdproto 276 CONFIG_CRAYL1 CONFIG_IVMS8_256 CONFIG_sacsng 277 CONFIG_CSB272 CONFIG_JSE CONFIG_Sandpoint8240 278 CONFIG_CU824 CONFIG_LANTEC CONFIG_Sandpoint8245 279 CONFIG_DASA_SIM CONFIG_lwmon CONFIG_sbc8260 280 CONFIG_DB64360 CONFIG_MBX CONFIG_sbc8560 281 CONFIG_DB64460 CONFIG_MBX860T CONFIG_SM850 282 CONFIG_DU405 CONFIG_MHPC CONFIG_SPD823TS 283 CONFIG_DUET_ADS CONFIG_MIP405 CONFIG_STXGP3 284 CONFIG_EBONY CONFIG_MOUSSE CONFIG_SXNI855T 285 CONFIG_ELPPC CONFIG_MPC8260ADS CONFIG_TQM823L 286 CONFIG_ELPT860 CONFIG_MPC8540ADS CONFIG_TQM8260 287 CONFIG_ep8260 CONFIG_MPC8560ADS CONFIG_TQM850L 288 CONFIG_ERIC CONFIG_MUSENKI CONFIG_TQM855L 289 CONFIG_ESTEEM192E CONFIG_MVS1 CONFIG_TQM860L 290 CONFIG_ETX094 CONFIG_NETPHONE CONFIG_TTTech 291 CONFIG_EVB64260 CONFIG_NETTA CONFIG_UTX8245 292 CONFIG_FADS823 CONFIG_NETVIA CONFIG_V37 293 CONFIG_FADS850SAR CONFIG_NX823 CONFIG_W7OLMC 294 CONFIG_FADS860T CONFIG_OCRTC CONFIG_W7OLMG 295 CONFIG_FLAGADM CONFIG_ORSG CONFIG_WALNUT405 296 CONFIG_FPS850L CONFIG_OXC CONFIG_ZPC1900 297 CONFIG_FPS860L CONFIG_ZUMA 298 299 ARM based boards: 300 ----------------- 301 302 CONFIG_AT91RM9200DK, CONFIG_CERF250, CONFIG_DNP1110, 303 CONFIG_EP7312, CONFIG_H2_OMAP1610, CONFIG_HHP_CRADLE, 304 CONFIG_IMPA7, CONFIG_INNOVATOROMAP1510, CONFIG_INNOVATOROMAP1610, 305 CONFIG_LART, CONFIG_LPD7A400 CONFIG_LUBBOCK, 306 CONFIG_OSK_OMAP5912, CONFIG_SHANNON, CONFIG_P2_OMAP730, 307 CONFIG_SMDK2400, CONFIG_SMDK2410, CONFIG_TRAB, 308 CONFIG_VCMA9 309 310 MicroBlaze based boards: 311 ------------------------ 312 313 CONFIG_SUZAKU 314 315 Nios-2 based boards: 316 ------------------------ 317 318 CONFIG_PCI5441 CONFIG_PK1C20 319 320 321- CPU Module Type: (if CONFIG_COGENT is defined) 322 Define exactly one of 323 CONFIG_CMA286_60_OLD 324--- FIXME --- not tested yet: 325 CONFIG_CMA286_60, CONFIG_CMA286_21, CONFIG_CMA286_60P, 326 CONFIG_CMA287_23, CONFIG_CMA287_50 327 328- Motherboard Type: (if CONFIG_COGENT is defined) 329 Define exactly one of 330 CONFIG_CMA101, CONFIG_CMA102 331 332- Motherboard I/O Modules: (if CONFIG_COGENT is defined) 333 Define one or more of 334 CONFIG_CMA302 335 336- Motherboard Options: (if CONFIG_CMA101 or CONFIG_CMA102 are defined) 337 Define one or more of 338 CONFIG_LCD_HEARTBEAT - update a character position on 339 the lcd display every second with 340 a "rotator" |\-/|\-/ 341 342- Board flavour: (if CONFIG_MPC8260ADS is defined) 343 CONFIG_ADSTYPE 344 Possible values are: 345 CFG_8260ADS - original MPC8260ADS 346 CFG_8266ADS - MPC8266ADS 347 CFG_PQ2FADS - PQ2FADS-ZU or PQ2FADS-VR 348 CFG_8272ADS - MPC8272ADS 349 350- MPC824X Family Member (if CONFIG_MPC824X is defined) 351 Define exactly one of 352 CONFIG_MPC8240, CONFIG_MPC8245 353 354- 8xx CPU Options: (if using an MPC8xx cpu) 355 CONFIG_8xx_GCLK_FREQ - deprecated: CPU clock if 356 get_gclk_freq() cannot work 357 e.g. if there is no 32KHz 358 reference PIT/RTC clock 359 CONFIG_8xx_OSCLK - PLL input clock (either EXTCLK 360 or XTAL/EXTAL) 361 362- 859/866/885 CPU options: (if using a MPC859 or MPC866 or MPC885 CPU): 363 CFG_8xx_CPUCLK_MIN 364 CFG_8xx_CPUCLK_MAX 365 CONFIG_8xx_CPUCLK_DEFAULT 366 See doc/README.MPC866 367 368 CFG_MEASURE_CPUCLK 369 370 Define this to measure the actual CPU clock instead 371 of relying on the correctness of the configured 372 values. Mostly useful for board bringup to make sure 373 the PLL is locked at the intended frequency. Note 374 that this requires a (stable) reference clock (32 kHz 375 RTC clock or CFG_8XX_XIN) 376 377- Linux Kernel Interface: 378 CONFIG_CLOCKS_IN_MHZ 379 380 U-Boot stores all clock information in Hz 381 internally. For binary compatibility with older Linux 382 kernels (which expect the clocks passed in the 383 bd_info data to be in MHz) the environment variable 384 "clocks_in_mhz" can be defined so that U-Boot 385 converts clock data to MHZ before passing it to the 386 Linux kernel. 387 When CONFIG_CLOCKS_IN_MHZ is defined, a definition of 388 "clocks_in_mhz=1" is automatically included in the 389 default environment. 390 391 CONFIG_MEMSIZE_IN_BYTES [relevant for MIPS only] 392 393 When transfering memsize parameter to linux, some versions 394 expect it to be in bytes, others in MB. 395 Define CONFIG_MEMSIZE_IN_BYTES to make it in bytes. 396 397- Serial Ports: 398 CFG_PL010_SERIAL 399 400 Define this if you want support for Amba PrimeCell PL010 UARTs. 401 402 CFG_PL011_SERIAL 403 404 Define this if you want support for Amba PrimeCell PL011 UARTs. 405 406 CONFIG_PL011_CLOCK 407 408 If you have Amba PrimeCell PL011 UARTs, set this variable to 409 the clock speed of the UARTs. 410 411 CONFIG_PL01x_PORTS 412 413 If you have Amba PrimeCell PL010 or PL011 UARTs on your board, 414 define this to a list of base addresses for each (supported) 415 port. See e.g. include/configs/versatile.h 416 417 418- Console Interface: 419 Depending on board, define exactly one serial port 420 (like CONFIG_8xx_CONS_SMC1, CONFIG_8xx_CONS_SMC2, 421 CONFIG_8xx_CONS_SCC1, ...), or switch off the serial 422 console by defining CONFIG_8xx_CONS_NONE 423 424 Note: if CONFIG_8xx_CONS_NONE is defined, the serial 425 port routines must be defined elsewhere 426 (i.e. serial_init(), serial_getc(), ...) 427 428 CONFIG_CFB_CONSOLE 429 Enables console device for a color framebuffer. Needs following 430 defines (cf. smiLynxEM, i8042, board/eltec/bab7xx) 431 VIDEO_FB_LITTLE_ENDIAN graphic memory organisation 432 (default big endian) 433 VIDEO_HW_RECTFILL graphic chip supports 434 rectangle fill 435 (cf. smiLynxEM) 436 VIDEO_HW_BITBLT graphic chip supports 437 bit-blit (cf. smiLynxEM) 438 VIDEO_VISIBLE_COLS visible pixel columns 439 (cols=pitch) 440 VIDEO_VISIBLE_ROWS visible pixel rows 441 VIDEO_PIXEL_SIZE bytes per pixel 442 VIDEO_DATA_FORMAT graphic data format 443 (0-5, cf. cfb_console.c) 444 VIDEO_FB_ADRS framebuffer address 445 VIDEO_KBD_INIT_FCT keyboard int fct 446 (i.e. i8042_kbd_init()) 447 VIDEO_TSTC_FCT test char fct 448 (i.e. i8042_tstc) 449 VIDEO_GETC_FCT get char fct 450 (i.e. i8042_getc) 451 CONFIG_CONSOLE_CURSOR cursor drawing on/off 452 (requires blink timer 453 cf. i8042.c) 454 CFG_CONSOLE_BLINK_COUNT blink interval (cf. i8042.c) 455 CONFIG_CONSOLE_TIME display time/date info in 456 upper right corner 457 (requires CFG_CMD_DATE) 458 CONFIG_VIDEO_LOGO display Linux logo in 459 upper left corner 460 CONFIG_VIDEO_BMP_LOGO use bmp_logo.h instead of 461 linux_logo.h for logo. 462 Requires CONFIG_VIDEO_LOGO 463 CONFIG_CONSOLE_EXTRA_INFO 464 addional board info beside 465 the logo 466 467 When CONFIG_CFB_CONSOLE is defined, video console is 468 default i/o. Serial console can be forced with 469 environment 'console=serial'. 470 471 When CONFIG_SILENT_CONSOLE is defined, all console 472 messages (by U-Boot and Linux!) can be silenced with 473 the "silent" environment variable. See 474 doc/README.silent for more information. 475 476- Console Baudrate: 477 CONFIG_BAUDRATE - in bps 478 Select one of the baudrates listed in 479 CFG_BAUDRATE_TABLE, see below. 480 CFG_BRGCLK_PRESCALE, baudrate prescale 481 482- Interrupt driven serial port input: 483 CONFIG_SERIAL_SOFTWARE_FIFO 484 485 PPC405GP only. 486 Use an interrupt handler for receiving data on the 487 serial port. It also enables using hardware handshake 488 (RTS/CTS) and UART's built-in FIFO. Set the number of 489 bytes the interrupt driven input buffer should have. 490 491 Leave undefined to disable this feature, including 492 disable the buffer and hardware handshake. 493 494- Console UART Number: 495 CONFIG_UART1_CONSOLE 496 497 IBM PPC4xx only. 498 If defined internal UART1 (and not UART0) is used 499 as default U-Boot console. 500 501- Boot Delay: CONFIG_BOOTDELAY - in seconds 502 Delay before automatically booting the default image; 503 set to -1 to disable autoboot. 504 505 See doc/README.autoboot for these options that 506 work with CONFIG_BOOTDELAY. None are required. 507 CONFIG_BOOT_RETRY_TIME 508 CONFIG_BOOT_RETRY_MIN 509 CONFIG_AUTOBOOT_KEYED 510 CONFIG_AUTOBOOT_PROMPT 511 CONFIG_AUTOBOOT_DELAY_STR 512 CONFIG_AUTOBOOT_STOP_STR 513 CONFIG_AUTOBOOT_DELAY_STR2 514 CONFIG_AUTOBOOT_STOP_STR2 515 CONFIG_ZERO_BOOTDELAY_CHECK 516 CONFIG_RESET_TO_RETRY 517 518- Autoboot Command: 519 CONFIG_BOOTCOMMAND 520 Only needed when CONFIG_BOOTDELAY is enabled; 521 define a command string that is automatically executed 522 when no character is read on the console interface 523 within "Boot Delay" after reset. 524 525 CONFIG_BOOTARGS 526 This can be used to pass arguments to the bootm 527 command. The value of CONFIG_BOOTARGS goes into the 528 environment value "bootargs". 529 530 CONFIG_RAMBOOT and CONFIG_NFSBOOT 531 The value of these goes into the environment as 532 "ramboot" and "nfsboot" respectively, and can be used 533 as a convenience, when switching between booting from 534 ram and nfs. 535 536- Pre-Boot Commands: 537 CONFIG_PREBOOT 538 539 When this option is #defined, the existence of the 540 environment variable "preboot" will be checked 541 immediately before starting the CONFIG_BOOTDELAY 542 countdown and/or running the auto-boot command resp. 543 entering interactive mode. 544 545 This feature is especially useful when "preboot" is 546 automatically generated or modified. For an example 547 see the LWMON board specific code: here "preboot" is 548 modified when the user holds down a certain 549 combination of keys on the (special) keyboard when 550 booting the systems 551 552- Serial Download Echo Mode: 553 CONFIG_LOADS_ECHO 554 If defined to 1, all characters received during a 555 serial download (using the "loads" command) are 556 echoed back. This might be needed by some terminal 557 emulations (like "cu"), but may as well just take 558 time on others. This setting #define's the initial 559 value of the "loads_echo" environment variable. 560 561- Kgdb Serial Baudrate: (if CFG_CMD_KGDB is defined) 562 CONFIG_KGDB_BAUDRATE 563 Select one of the baudrates listed in 564 CFG_BAUDRATE_TABLE, see below. 565 566- Monitor Functions: 567 CONFIG_COMMANDS 568 Most monitor functions can be selected (or 569 de-selected) by adjusting the definition of 570 CONFIG_COMMANDS; to select individual functions, 571 #define CONFIG_COMMANDS by "OR"ing any of the 572 following values: 573 574 #define enables commands: 575 ------------------------- 576 CFG_CMD_ASKENV * ask for env variable 577 CFG_CMD_AUTOSCRIPT Autoscript Support 578 CFG_CMD_BDI bdinfo 579 CFG_CMD_BEDBUG * Include BedBug Debugger 580 CFG_CMD_BMP * BMP support 581 CFG_CMD_BSP * Board specific commands 582 CFG_CMD_BOOTD bootd 583 CFG_CMD_CACHE * icache, dcache 584 CFG_CMD_CONSOLE coninfo 585 CFG_CMD_DATE * support for RTC, date/time... 586 CFG_CMD_DHCP * DHCP support 587 CFG_CMD_DIAG * Diagnostics 588 CFG_CMD_DOC * Disk-On-Chip Support 589 CFG_CMD_DTT * Digital Therm and Thermostat 590 CFG_CMD_ECHO * echo arguments 591 CFG_CMD_EEPROM * EEPROM read/write support 592 CFG_CMD_ELF * bootelf, bootvx 593 CFG_CMD_ENV saveenv 594 CFG_CMD_FDC * Floppy Disk Support 595 CFG_CMD_FAT * FAT partition support 596 CFG_CMD_FDOS * Dos diskette Support 597 CFG_CMD_FLASH flinfo, erase, protect 598 CFG_CMD_FPGA FPGA device initialization support 599 CFG_CMD_HWFLOW * RTS/CTS hw flow control 600 CFG_CMD_I2C * I2C serial bus support 601 CFG_CMD_IDE * IDE harddisk support 602 CFG_CMD_IMI iminfo 603 CFG_CMD_IMLS List all found images 604 CFG_CMD_IMMAP * IMMR dump support 605 CFG_CMD_IRQ * irqinfo 606 CFG_CMD_ITEST Integer/string test of 2 values 607 CFG_CMD_JFFS2 * JFFS2 Support 608 CFG_CMD_KGDB * kgdb 609 CFG_CMD_LOADB loadb 610 CFG_CMD_LOADS loads 611 CFG_CMD_MEMORY md, mm, nm, mw, cp, cmp, crc, base, 612 loop, loopw, mtest 613 CFG_CMD_MISC Misc functions like sleep etc 614 CFG_CMD_MMC * MMC memory mapped support 615 CFG_CMD_MII * MII utility commands 616 CFG_CMD_NAND * NAND support 617 CFG_CMD_NET bootp, tftpboot, rarpboot 618 CFG_CMD_PCI * pciinfo 619 CFG_CMD_PCMCIA * PCMCIA support 620 CFG_CMD_PING * send ICMP ECHO_REQUEST to network host 621 CFG_CMD_PORTIO * Port I/O 622 CFG_CMD_REGINFO * Register dump 623 CFG_CMD_RUN run command in env variable 624 CFG_CMD_SAVES * save S record dump 625 CFG_CMD_SCSI * SCSI Support 626 CFG_CMD_SDRAM * print SDRAM configuration information 627 CFG_CMD_SETGETDCR Support for DCR Register access (4xx only) 628 CFG_CMD_SPI * SPI serial bus support 629 CFG_CMD_USB * USB support 630 CFG_CMD_VFD * VFD support (TRAB) 631 CFG_CMD_BSP * Board SPecific functions 632 CFG_CMD_CDP * Cisco Discover Protocol support 633 ----------------------------------------------- 634 CFG_CMD_ALL all 635 636 CONFIG_CMD_DFL Default configuration; at the moment 637 this is includes all commands, except 638 the ones marked with "*" in the list 639 above. 640 641 If you don't define CONFIG_COMMANDS it defaults to 642 CONFIG_CMD_DFL in include/cmd_confdefs.h. A board can 643 override the default settings in the respective 644 include file. 645 646 EXAMPLE: If you want all functions except of network 647 support you can write: 648 649 #define CONFIG_COMMANDS (CFG_CMD_ALL & ~CFG_CMD_NET) 650 651 652 Note: Don't enable the "icache" and "dcache" commands 653 (configuration option CFG_CMD_CACHE) unless you know 654 what you (and your U-Boot users) are doing. Data 655 cache cannot be enabled on systems like the 8xx or 656 8260 (where accesses to the IMMR region must be 657 uncached), and it cannot be disabled on all other 658 systems where we (mis-) use the data cache to hold an 659 initial stack and some data. 660 661 662 XXX - this list needs to get updated! 663 664- Watchdog: 665 CONFIG_WATCHDOG 666 If this variable is defined, it enables watchdog 667 support. There must be support in the platform specific 668 code for a watchdog. For the 8xx and 8260 CPUs, the 669 SIU Watchdog feature is enabled in the SYPCR 670 register. 671 672- U-Boot Version: 673 CONFIG_VERSION_VARIABLE 674 If this variable is defined, an environment variable 675 named "ver" is created by U-Boot showing the U-Boot 676 version as printed by the "version" command. 677 This variable is readonly. 678 679- Real-Time Clock: 680 681 When CFG_CMD_DATE is selected, the type of the RTC 682 has to be selected, too. Define exactly one of the 683 following options: 684 685 CONFIG_RTC_MPC8xx - use internal RTC of MPC8xx 686 CONFIG_RTC_PCF8563 - use Philips PCF8563 RTC 687 CONFIG_RTC_MC146818 - use MC146818 RTC 688 CONFIG_RTC_DS1307 - use Maxim, Inc. DS1307 RTC 689 CONFIG_RTC_DS1337 - use Maxim, Inc. DS1337 RTC 690 CONFIG_RTC_DS1338 - use Maxim, Inc. DS1338 RTC 691 CONFIG_RTC_DS164x - use Dallas DS164x RTC 692 CONFIG_RTC_MAX6900 - use Maxim, Inc. MAX6900 RTC 693 694 Note that if the RTC uses I2C, then the I2C interface 695 must also be configured. See I2C Support, below. 696 697- Timestamp Support: 698 699 When CONFIG_TIMESTAMP is selected, the timestamp 700 (date and time) of an image is printed by image 701 commands like bootm or iminfo. This option is 702 automatically enabled when you select CFG_CMD_DATE . 703 704- Partition Support: 705 CONFIG_MAC_PARTITION and/or CONFIG_DOS_PARTITION 706 and/or CONFIG_ISO_PARTITION 707 708 If IDE or SCSI support is enabled (CFG_CMD_IDE or 709 CFG_CMD_SCSI) you must configure support for at least 710 one partition type as well. 711 712- IDE Reset method: 713 CONFIG_IDE_RESET_ROUTINE - this is defined in several 714 board configurations files but used nowhere! 715 716 CONFIG_IDE_RESET - is this is defined, IDE Reset will 717 be performed by calling the function 718 ide_set_reset(int reset) 719 which has to be defined in a board specific file 720 721- ATAPI Support: 722 CONFIG_ATAPI 723 724 Set this to enable ATAPI support. 725 726- LBA48 Support 727 CONFIG_LBA48 728 729 Set this to enable support for disks larger than 137GB 730 Also look at CFG_64BIT_LBA ,CFG_64BIT_VSPRINTF and CFG_64BIT_STRTOUL 731 Whithout these , LBA48 support uses 32bit variables and will 'only' 732 support disks up to 2.1TB. 733 734 CFG_64BIT_LBA: 735 When enabled, makes the IDE subsystem use 64bit sector addresses. 736 Default is 32bit. 737 738- SCSI Support: 739 At the moment only there is only support for the 740 SYM53C8XX SCSI controller; define 741 CONFIG_SCSI_SYM53C8XX to enable it. 742 743 CFG_SCSI_MAX_LUN [8], CFG_SCSI_MAX_SCSI_ID [7] and 744 CFG_SCSI_MAX_DEVICE [CFG_SCSI_MAX_SCSI_ID * 745 CFG_SCSI_MAX_LUN] can be adjusted to define the 746 maximum numbers of LUNs, SCSI ID's and target 747 devices. 748 CFG_SCSI_SYM53C8XX_CCF to fix clock timing (80Mhz) 749 750- NETWORK Support (PCI): 751 CONFIG_E1000 752 Support for Intel 8254x gigabit chips. 753 754 CONFIG_EEPRO100 755 Support for Intel 82557/82559/82559ER chips. 756 Optional CONFIG_EEPRO100_SROM_WRITE enables eeprom 757 write routine for first time initialisation. 758 759 CONFIG_TULIP 760 Support for Digital 2114x chips. 761 Optional CONFIG_TULIP_SELECT_MEDIA for board specific 762 modem chip initialisation (KS8761/QS6611). 763 764 CONFIG_NATSEMI 765 Support for National dp83815 chips. 766 767 CONFIG_NS8382X 768 Support for National dp8382[01] gigabit chips. 769 770- NETWORK Support (other): 771 772 CONFIG_DRIVER_LAN91C96 773 Support for SMSC's LAN91C96 chips. 774 775 CONFIG_LAN91C96_BASE 776 Define this to hold the physical address 777 of the LAN91C96's I/O space 778 779 CONFIG_LAN91C96_USE_32_BIT 780 Define this to enable 32 bit addressing 781 782 CONFIG_DRIVER_SMC91111 783 Support for SMSC's LAN91C111 chip 784 785 CONFIG_SMC91111_BASE 786 Define this to hold the physical address 787 of the device (I/O space) 788 789 CONFIG_SMC_USE_32_BIT 790 Define this if data bus is 32 bits 791 792 CONFIG_SMC_USE_IOFUNCS 793 Define this to use i/o functions instead of macros 794 (some hardware wont work with macros) 795 796- USB Support: 797 At the moment only the UHCI host controller is 798 supported (PIP405, MIP405, MPC5200); define 799 CONFIG_USB_UHCI to enable it. 800 define CONFIG_USB_KEYBOARD to enable the USB Keyboard 801 and define CONFIG_USB_STORAGE to enable the USB 802 storage devices. 803 Note: 804 Supported are USB Keyboards and USB Floppy drives 805 (TEAC FD-05PUB). 806 MPC5200 USB requires additional defines: 807 CONFIG_USB_CLOCK 808 for 528 MHz Clock: 0x0001bbbb 809 CONFIG_USB_CONFIG 810 for differential drivers: 0x00001000 811 for single ended drivers: 0x00005000 812 813 814- MMC Support: 815 The MMC controller on the Intel PXA is supported. To 816 enable this define CONFIG_MMC. The MMC can be 817 accessed from the boot prompt by mapping the device 818 to physical memory similar to flash. Command line is 819 enabled with CFG_CMD_MMC. The MMC driver also works with 820 the FAT fs. This is enabled with CFG_CMD_FAT. 821 822- Journaling Flash filesystem support: 823 CONFIG_JFFS2_NAND, CONFIG_JFFS2_NAND_OFF, CONFIG_JFFS2_NAND_SIZE, 824 CONFIG_JFFS2_NAND_DEV 825 Define these for a default partition on a NAND device 826 827 CFG_JFFS2_FIRST_SECTOR, 828 CFG_JFFS2_FIRST_BANK, CFG_JFFS2_NUM_BANKS 829 Define these for a default partition on a NOR device 830 831 CFG_JFFS_CUSTOM_PART 832 Define this to create an own partition. You have to provide a 833 function struct part_info* jffs2_part_info(int part_num) 834 835 If you define only one JFFS2 partition you may also want to 836 #define CFG_JFFS_SINGLE_PART 1 837 to disable the command chpart. This is the default when you 838 have not defined a custom partition 839 840- Keyboard Support: 841 CONFIG_ISA_KEYBOARD 842 843 Define this to enable standard (PC-Style) keyboard 844 support 845 846 CONFIG_I8042_KBD 847 Standard PC keyboard driver with US (is default) and 848 GERMAN key layout (switch via environment 'keymap=de') support. 849 Export function i8042_kbd_init, i8042_tstc and i8042_getc 850 for cfb_console. Supports cursor blinking. 851 852- Video support: 853 CONFIG_VIDEO 854 855 Define this to enable video support (for output to 856 video). 857 858 CONFIG_VIDEO_CT69000 859 860 Enable Chips & Technologies 69000 Video chip 861 862 CONFIG_VIDEO_SMI_LYNXEM 863 Enable Silicon Motion SMI 712/710/810 Video chip. The 864 video output is selected via environment 'videoout' 865 (1 = LCD and 2 = CRT). If videoout is undefined, CRT is 866 assumed. 867 868 For the CT69000 and SMI_LYNXEM drivers, videomode is 869 selected via environment 'videomode'. Two diferent ways 870 are possible: 871 - "videomode=num" 'num' is a standard LiLo mode numbers. 872 Following standard modes are supported (* is default): 873 874 Colors 640x480 800x600 1024x768 1152x864 1280x1024 875 -------------+--------------------------------------------- 876 8 bits | 0x301* 0x303 0x305 0x161 0x307 877 15 bits | 0x310 0x313 0x316 0x162 0x319 878 16 bits | 0x311 0x314 0x317 0x163 0x31A 879 24 bits | 0x312 0x315 0x318 ? 0x31B 880 -------------+--------------------------------------------- 881 (i.e. setenv videomode 317; saveenv; reset;) 882 883 - "videomode=bootargs" all the video parameters are parsed 884 from the bootargs. (See drivers/videomodes.c) 885 886 887 CONFIG_VIDEO_SED13806 888 Enable Epson SED13806 driver. This driver supports 8bpp 889 and 16bpp modes defined by CONFIG_VIDEO_SED13806_8BPP 890 or CONFIG_VIDEO_SED13806_16BPP 891 892- Keyboard Support: 893 CONFIG_KEYBOARD 894 895 Define this to enable a custom keyboard support. 896 This simply calls drv_keyboard_init() which must be 897 defined in your board-specific files. 898 The only board using this so far is RBC823. 899 900- LCD Support: CONFIG_LCD 901 902 Define this to enable LCD support (for output to LCD 903 display); also select one of the supported displays 904 by defining one of these: 905 906 CONFIG_NEC_NL6448AC33: 907 908 NEC NL6448AC33-18. Active, color, single scan. 909 910 CONFIG_NEC_NL6448BC20 911 912 NEC NL6448BC20-08. 6.5", 640x480. 913 Active, color, single scan. 914 915 CONFIG_NEC_NL6448BC33_54 916 917 NEC NL6448BC33-54. 10.4", 640x480. 918 Active, color, single scan. 919 920 CONFIG_SHARP_16x9 921 922 Sharp 320x240. Active, color, single scan. 923 It isn't 16x9, and I am not sure what it is. 924 925 CONFIG_SHARP_LQ64D341 926 927 Sharp LQ64D341 display, 640x480. 928 Active, color, single scan. 929 930 CONFIG_HLD1045 931 932 HLD1045 display, 640x480. 933 Active, color, single scan. 934 935 CONFIG_OPTREX_BW 936 937 Optrex CBL50840-2 NF-FW 99 22 M5 938 or 939 Hitachi LMG6912RPFC-00T 940 or 941 Hitachi SP14Q002 942 943 320x240. Black & white. 944 945 Normally display is black on white background; define 946 CFG_WHITE_ON_BLACK to get it inverted. 947 948- Splash Screen Support: CONFIG_SPLASH_SCREEN 949 950 If this option is set, the environment is checked for 951 a variable "splashimage". If found, the usual display 952 of logo, copyright and system information on the LCD 953 is suppressed and the BMP image at the address 954 specified in "splashimage" is loaded instead. The 955 console is redirected to the "nulldev", too. This 956 allows for a "silent" boot where a splash screen is 957 loaded very quickly after power-on. 958 959- Compression support: 960 CONFIG_BZIP2 961 962 If this option is set, support for bzip2 compressed 963 images is included. If not, only uncompressed and gzip 964 compressed images are supported. 965 966 NOTE: the bzip2 algorithm requires a lot of RAM, so 967 the malloc area (as defined by CFG_MALLOC_LEN) should 968 be at least 4MB. 969 970- MII/PHY support: 971 CONFIG_PHY_ADDR 972 973 The address of PHY on MII bus. 974 975 CONFIG_PHY_CLOCK_FREQ (ppc4xx) 976 977 The clock frequency of the MII bus 978 979 CONFIG_PHY_GIGE 980 981 If this option is set, support for speed/duplex 982 detection of Gigabit PHY is included. 983 984 CONFIG_PHY_RESET_DELAY 985 986 Some PHY like Intel LXT971A need extra delay after 987 reset before any MII register access is possible. 988 For such PHY, set this option to the usec delay 989 required. (minimum 300usec for LXT971A) 990 991 CONFIG_PHY_CMD_DELAY (ppc4xx) 992 993 Some PHY like Intel LXT971A need extra delay after 994 command issued before MII status register can be read 995 996- Ethernet address: 997 CONFIG_ETHADDR 998 CONFIG_ETH2ADDR 999 CONFIG_ETH3ADDR 1000 1001 Define a default value for ethernet address to use 1002 for the respective ethernet interface, in case this 1003 is not determined automatically. 1004 1005- IP address: 1006 CONFIG_IPADDR 1007 1008 Define a default value for the IP address to use for 1009 the default ethernet interface, in case this is not 1010 determined through e.g. bootp. 1011 1012- Server IP address: 1013 CONFIG_SERVERIP 1014 1015 Defines a default value for theIP address of a TFTP 1016 server to contact when using the "tftboot" command. 1017 1018- BOOTP Recovery Mode: 1019 CONFIG_BOOTP_RANDOM_DELAY 1020 1021 If you have many targets in a network that try to 1022 boot using BOOTP, you may want to avoid that all 1023 systems send out BOOTP requests at precisely the same 1024 moment (which would happen for instance at recovery 1025 from a power failure, when all systems will try to 1026 boot, thus flooding the BOOTP server. Defining 1027 CONFIG_BOOTP_RANDOM_DELAY causes a random delay to be 1028 inserted before sending out BOOTP requests. The 1029 following delays are insterted then: 1030 1031 1st BOOTP request: delay 0 ... 1 sec 1032 2nd BOOTP request: delay 0 ... 2 sec 1033 3rd BOOTP request: delay 0 ... 4 sec 1034 4th and following 1035 BOOTP requests: delay 0 ... 8 sec 1036 1037- DHCP Advanced Options: 1038 CONFIG_BOOTP_MASK 1039 1040 You can fine tune the DHCP functionality by adding 1041 these flags to the CONFIG_BOOTP_MASK define: 1042 1043 CONFIG_BOOTP_DNS2 - If a DHCP client requests the DNS 1044 serverip from a DHCP server, it is possible that more 1045 than one DNS serverip is offered to the client. 1046 If CONFIG_BOOTP_DNS2 is enabled, the secondary DNS 1047 serverip will be stored in the additional environment 1048 variable "dnsip2". The first DNS serverip is always 1049 stored in the variable "dnsip", when CONFIG_BOOTP_DNS 1050 is added to the CONFIG_BOOTP_MASK. 1051 1052 CONFIG_BOOTP_SEND_HOSTNAME - Some DHCP servers are capable 1053 to do a dynamic update of a DNS server. To do this, they 1054 need the hostname of the DHCP requester. 1055 If CONFIG_BOOP_SEND_HOSTNAME is added to the 1056 CONFIG_BOOTP_MASK, the content of the "hostname" 1057 environment variable is passed as option 12 to 1058 the DHCP server. 1059 1060 - CDP Options: 1061 CONFIG_CDP_DEVICE_ID 1062 1063 The device id used in CDP trigger frames. 1064 1065 CONFIG_CDP_DEVICE_ID_PREFIX 1066 1067 A two character string which is prefixed to the MAC address 1068 of the device. 1069 1070 CONFIG_CDP_PORT_ID 1071 1072 A printf format string which contains the ascii name of 1073 the port. Normally is set to "eth%d" which sets 1074 eth0 for the first ethernet, eth1 for the second etc. 1075 1076 CONFIG_CDP_CAPABILITIES 1077 1078 A 32bit integer which indicates the device capabilities; 1079 0x00000010 for a normal host which does not forwards. 1080 1081 CONFIG_CDP_VERSION 1082 1083 An ascii string containing the version of the software. 1084 1085 CONFIG_CDP_PLATFORM 1086 1087 An ascii string containing the name of the platform. 1088 1089 CONFIG_CDP_TRIGGER 1090 1091 A 32bit integer sent on the trigger. 1092 1093 CONFIG_CDP_POWER_CONSUMPTION 1094 1095 A 16bit integer containing the power consumption of the 1096 device in .1 of milliwatts. 1097 1098 CONFIG_CDP_APPLIANCE_VLAN_TYPE 1099 1100 A byte containing the id of the VLAN. 1101 1102- Status LED: CONFIG_STATUS_LED 1103 1104 Several configurations allow to display the current 1105 status using a LED. For instance, the LED will blink 1106 fast while running U-Boot code, stop blinking as 1107 soon as a reply to a BOOTP request was received, and 1108 start blinking slow once the Linux kernel is running 1109 (supported by a status LED driver in the Linux 1110 kernel). Defining CONFIG_STATUS_LED enables this 1111 feature in U-Boot. 1112 1113- CAN Support: CONFIG_CAN_DRIVER 1114 1115 Defining CONFIG_CAN_DRIVER enables CAN driver support 1116 on those systems that support this (optional) 1117 feature, like the TQM8xxL modules. 1118 1119- I2C Support: CONFIG_HARD_I2C | CONFIG_SOFT_I2C 1120 1121 These enable I2C serial bus commands. Defining either of 1122 (but not both of) CONFIG_HARD_I2C or CONFIG_SOFT_I2C will 1123 include the appropriate I2C driver for the selected cpu. 1124 1125 This will allow you to use i2c commands at the u-boot 1126 command line (as long as you set CFG_CMD_I2C in 1127 CONFIG_COMMANDS) and communicate with i2c based realtime 1128 clock chips. See common/cmd_i2c.c for a description of the 1129 command line interface. 1130 1131 CONFIG_HARD_I2C selects the CPM hardware driver for I2C. 1132 1133 CONFIG_SOFT_I2C configures u-boot to use a software (aka 1134 bit-banging) driver instead of CPM or similar hardware 1135 support for I2C. 1136 1137 There are several other quantities that must also be 1138 defined when you define CONFIG_HARD_I2C or CONFIG_SOFT_I2C. 1139 1140 In both cases you will need to define CFG_I2C_SPEED 1141 to be the frequency (in Hz) at which you wish your i2c bus 1142 to run and CFG_I2C_SLAVE to be the address of this node (ie 1143 the cpu's i2c node address). 1144 1145 Now, the u-boot i2c code for the mpc8xx (cpu/mpc8xx/i2c.c) 1146 sets the cpu up as a master node and so its address should 1147 therefore be cleared to 0 (See, eg, MPC823e User's Manual 1148 p.16-473). So, set CFG_I2C_SLAVE to 0. 1149 1150 That's all that's required for CONFIG_HARD_I2C. 1151 1152 If you use the software i2c interface (CONFIG_SOFT_I2C) 1153 then the following macros need to be defined (examples are 1154 from include/configs/lwmon.h): 1155 1156 I2C_INIT 1157 1158 (Optional). Any commands necessary to enable the I2C 1159 controller or configure ports. 1160 1161 eg: #define I2C_INIT (immr->im_cpm.cp_pbdir |= PB_SCL) 1162 1163 I2C_PORT 1164 1165 (Only for MPC8260 CPU). The I/O port to use (the code 1166 assumes both bits are on the same port). Valid values 1167 are 0..3 for ports A..D. 1168 1169 I2C_ACTIVE 1170 1171 The code necessary to make the I2C data line active 1172 (driven). If the data line is open collector, this 1173 define can be null. 1174 1175 eg: #define I2C_ACTIVE (immr->im_cpm.cp_pbdir |= PB_SDA) 1176 1177 I2C_TRISTATE 1178 1179 The code necessary to make the I2C data line tri-stated 1180 (inactive). If the data line is open collector, this 1181 define can be null. 1182 1183 eg: #define I2C_TRISTATE (immr->im_cpm.cp_pbdir &= ~PB_SDA) 1184 1185 I2C_READ 1186 1187 Code that returns TRUE if the I2C data line is high, 1188 FALSE if it is low. 1189 1190 eg: #define I2C_READ ((immr->im_cpm.cp_pbdat & PB_SDA) != 0) 1191 1192 I2C_SDA(bit) 1193 1194 If <bit> is TRUE, sets the I2C data line high. If it 1195 is FALSE, it clears it (low). 1196 1197 eg: #define I2C_SDA(bit) \ 1198 if(bit) immr->im_cpm.cp_pbdat |= PB_SDA; \ 1199 else immr->im_cpm.cp_pbdat &= ~PB_SDA 1200 1201 I2C_SCL(bit) 1202 1203 If <bit> is TRUE, sets the I2C clock line high. If it 1204 is FALSE, it clears it (low). 1205 1206 eg: #define I2C_SCL(bit) \ 1207 if(bit) immr->im_cpm.cp_pbdat |= PB_SCL; \ 1208 else immr->im_cpm.cp_pbdat &= ~PB_SCL 1209 1210 I2C_DELAY 1211 1212 This delay is invoked four times per clock cycle so this 1213 controls the rate of data transfer. The data rate thus 1214 is 1 / (I2C_DELAY * 4). Often defined to be something 1215 like: 1216 1217 #define I2C_DELAY udelay(2) 1218 1219 CFG_I2C_INIT_BOARD 1220 1221 When a board is reset during an i2c bus transfer 1222 chips might think that the current transfer is still 1223 in progress. On some boards it is possible to access 1224 the i2c SCLK line directly, either by using the 1225 processor pin as a GPIO or by having a second pin 1226 connected to the bus. If this option is defined a 1227 custom i2c_init_board() routine in boards/xxx/board.c 1228 is run early in the boot sequence. 1229 1230 CONFIG_I2CFAST (PPC405GP|PPC405EP only) 1231 1232 This option enables configuration of bi_iic_fast[] flags 1233 in u-boot bd_info structure based on u-boot environment 1234 variable "i2cfast". (see also i2cfast) 1235 1236- SPI Support: CONFIG_SPI 1237 1238 Enables SPI driver (so far only tested with 1239 SPI EEPROM, also an instance works with Crystal A/D and 1240 D/As on the SACSng board) 1241 1242 CONFIG_SPI_X 1243 1244 Enables extended (16-bit) SPI EEPROM addressing. 1245 (symmetrical to CONFIG_I2C_X) 1246 1247 CONFIG_SOFT_SPI 1248 1249 Enables a software (bit-bang) SPI driver rather than 1250 using hardware support. This is a general purpose 1251 driver that only requires three general I/O port pins 1252 (two outputs, one input) to function. If this is 1253 defined, the board configuration must define several 1254 SPI configuration items (port pins to use, etc). For 1255 an example, see include/configs/sacsng.h. 1256 1257- FPGA Support: CONFIG_FPGA_COUNT 1258 1259 Specify the number of FPGA devices to support. 1260 1261 CONFIG_FPGA 1262 1263 Used to specify the types of FPGA devices. For example, 1264 #define CONFIG_FPGA CFG_XILINX_VIRTEX2 1265 1266 CFG_FPGA_PROG_FEEDBACK 1267 1268 Enable printing of hash marks during FPGA configuration. 1269 1270 CFG_FPGA_CHECK_BUSY 1271 1272 Enable checks on FPGA configuration interface busy 1273 status by the configuration function. This option 1274 will require a board or device specific function to 1275 be written. 1276 1277 CONFIG_FPGA_DELAY 1278 1279 If defined, a function that provides delays in the FPGA 1280 configuration driver. 1281 1282 CFG_FPGA_CHECK_CTRLC 1283 Allow Control-C to interrupt FPGA configuration 1284 1285 CFG_FPGA_CHECK_ERROR 1286 1287 Check for configuration errors during FPGA bitfile 1288 loading. For example, abort during Virtex II 1289 configuration if the INIT_B line goes low (which 1290 indicated a CRC error). 1291 1292 CFG_FPGA_WAIT_INIT 1293 1294 Maximum time to wait for the INIT_B line to deassert 1295 after PROB_B has been deasserted during a Virtex II 1296 FPGA configuration sequence. The default time is 500 1297 mS. 1298 1299 CFG_FPGA_WAIT_BUSY 1300 1301 Maximum time to wait for BUSY to deassert during 1302 Virtex II FPGA configuration. The default is 5 mS. 1303 1304 CFG_FPGA_WAIT_CONFIG 1305 1306 Time to wait after FPGA configuration. The default is 1307 200 mS. 1308 1309- Configuration Management: 1310 CONFIG_IDENT_STRING 1311 1312 If defined, this string will be added to the U-Boot 1313 version information (U_BOOT_VERSION) 1314 1315- Vendor Parameter Protection: 1316 1317 U-Boot considers the values of the environment 1318 variables "serial#" (Board Serial Number) and 1319 "ethaddr" (Ethernet Address) to be parameters that 1320 are set once by the board vendor / manufacturer, and 1321 protects these variables from casual modification by 1322 the user. Once set, these variables are read-only, 1323 and write or delete attempts are rejected. You can 1324 change this behviour: 1325 1326 If CONFIG_ENV_OVERWRITE is #defined in your config 1327 file, the write protection for vendor parameters is 1328 completely disabled. Anybody can change or delete 1329 these parameters. 1330 1331 Alternatively, if you #define _both_ CONFIG_ETHADDR 1332 _and_ CONFIG_OVERWRITE_ETHADDR_ONCE, a default 1333 ethernet address is installed in the environment, 1334 which can be changed exactly ONCE by the user. [The 1335 serial# is unaffected by this, i. e. it remains 1336 read-only.] 1337 1338- Protected RAM: 1339 CONFIG_PRAM 1340 1341 Define this variable to enable the reservation of 1342 "protected RAM", i. e. RAM which is not overwritten 1343 by U-Boot. Define CONFIG_PRAM to hold the number of 1344 kB you want to reserve for pRAM. You can overwrite 1345 this default value by defining an environment 1346 variable "pram" to the number of kB you want to 1347 reserve. Note that the board info structure will 1348 still show the full amount of RAM. If pRAM is 1349 reserved, a new environment variable "mem" will 1350 automatically be defined to hold the amount of 1351 remaining RAM in a form that can be passed as boot 1352 argument to Linux, for instance like that: 1353 1354 setenv bootargs ... mem=\$(mem) 1355 saveenv 1356 1357 This way you can tell Linux not to use this memory, 1358 either, which results in a memory region that will 1359 not be affected by reboots. 1360 1361 *WARNING* If your board configuration uses automatic 1362 detection of the RAM size, you must make sure that 1363 this memory test is non-destructive. So far, the 1364 following board configurations are known to be 1365 "pRAM-clean": 1366 1367 ETX094, IVMS8, IVML24, SPD8xx, TQM8xxL, 1368 HERMES, IP860, RPXlite, LWMON, LANTEC, 1369 PCU_E, FLAGADM, TQM8260 1370 1371- Error Recovery: 1372 CONFIG_PANIC_HANG 1373 1374 Define this variable to stop the system in case of a 1375 fatal error, so that you have to reset it manually. 1376 This is probably NOT a good idea for an embedded 1377 system where you want to system to reboot 1378 automatically as fast as possible, but it may be 1379 useful during development since you can try to debug 1380 the conditions that lead to the situation. 1381 1382 CONFIG_NET_RETRY_COUNT 1383 1384 This variable defines the number of retries for 1385 network operations like ARP, RARP, TFTP, or BOOTP 1386 before giving up the operation. If not defined, a 1387 default value of 5 is used. 1388 1389- Command Interpreter: 1390 CFG_AUTO_COMPLETE 1391 1392 Enable auto completion of commands using TAB. 1393 1394 CFG_HUSH_PARSER 1395 1396 Define this variable to enable the "hush" shell (from 1397 Busybox) as command line interpreter, thus enabling 1398 powerful command line syntax like 1399 if...then...else...fi conditionals or `&&' and '||' 1400 constructs ("shell scripts"). 1401 1402 If undefined, you get the old, much simpler behaviour 1403 with a somewhat smaller memory footprint. 1404 1405 1406 CFG_PROMPT_HUSH_PS2 1407 1408 This defines the secondary prompt string, which is 1409 printed when the command interpreter needs more input 1410 to complete a command. Usually "> ". 1411 1412 Note: 1413 1414 In the current implementation, the local variables 1415 space and global environment variables space are 1416 separated. Local variables are those you define by 1417 simply typing `name=value'. To access a local 1418 variable later on, you have write `$name' or 1419 `${name}'; to execute the contents of a variable 1420 directly type `$name' at the command prompt. 1421 1422 Global environment variables are those you use 1423 setenv/printenv to work with. To run a command stored 1424 in such a variable, you need to use the run command, 1425 and you must not use the '$' sign to access them. 1426 1427 To store commands and special characters in a 1428 variable, please use double quotation marks 1429 surrounding the whole text of the variable, instead 1430 of the backslashes before semicolons and special 1431 symbols. 1432 1433- Default Environment: 1434 CONFIG_EXTRA_ENV_SETTINGS 1435 1436 Define this to contain any number of null terminated 1437 strings (variable = value pairs) that will be part of 1438 the default environment compiled into the boot image. 1439 1440 For example, place something like this in your 1441 board's config file: 1442 1443 #define CONFIG_EXTRA_ENV_SETTINGS \ 1444 "myvar1=value1\0" \ 1445 "myvar2=value2\0" 1446 1447 Warning: This method is based on knowledge about the 1448 internal format how the environment is stored by the 1449 U-Boot code. This is NOT an official, exported 1450 interface! Although it is unlikely that this format 1451 will change soon, there is no guarantee either. 1452 You better know what you are doing here. 1453 1454 Note: overly (ab)use of the default environment is 1455 discouraged. Make sure to check other ways to preset 1456 the environment like the autoscript function or the 1457 boot command first. 1458 1459- DataFlash Support: 1460 CONFIG_HAS_DATAFLASH 1461 1462 Defining this option enables DataFlash features and 1463 allows to read/write in Dataflash via the standard 1464 commands cp, md... 1465 1466- SystemACE Support: 1467 CONFIG_SYSTEMACE 1468 1469 Adding this option adds support for Xilinx SystemACE 1470 chips attached via some sort of local bus. The address 1471 of the chip must alsh be defined in the 1472 CFG_SYSTEMACE_BASE macro. For example: 1473 1474 #define CONFIG_SYSTEMACE 1475 #define CFG_SYSTEMACE_BASE 0xf0000000 1476 1477 When SystemACE support is added, the "ace" device type 1478 becomes available to the fat commands, i.e. fatls. 1479 1480- Show boot progress: 1481 CONFIG_SHOW_BOOT_PROGRESS 1482 1483 Defining this option allows to add some board- 1484 specific code (calling a user-provided function 1485 "show_boot_progress(int)") that enables you to show 1486 the system's boot progress on some display (for 1487 example, some LED's) on your board. At the moment, 1488 the following checkpoints are implemented: 1489 1490 Arg Where When 1491 1 common/cmd_bootm.c before attempting to boot an image 1492 -1 common/cmd_bootm.c Image header has bad magic number 1493 2 common/cmd_bootm.c Image header has correct magic number 1494 -2 common/cmd_bootm.c Image header has bad checksum 1495 3 common/cmd_bootm.c Image header has correct checksum 1496 -3 common/cmd_bootm.c Image data has bad checksum 1497 4 common/cmd_bootm.c Image data has correct checksum 1498 -4 common/cmd_bootm.c Image is for unsupported architecture 1499 5 common/cmd_bootm.c Architecture check OK 1500 -5 common/cmd_bootm.c Wrong Image Type (not kernel, multi, standalone) 1501 6 common/cmd_bootm.c Image Type check OK 1502 -6 common/cmd_bootm.c gunzip uncompression error 1503 -7 common/cmd_bootm.c Unimplemented compression type 1504 7 common/cmd_bootm.c Uncompression OK 1505 -8 common/cmd_bootm.c Wrong Image Type (not kernel, multi, standalone) 1506 8 common/cmd_bootm.c Image Type check OK 1507 -9 common/cmd_bootm.c Unsupported OS (not Linux, BSD, VxWorks, QNX) 1508 9 common/cmd_bootm.c Start initial ramdisk verification 1509 -10 common/cmd_bootm.c Ramdisk header has bad magic number 1510 -11 common/cmd_bootm.c Ramdisk header has bad checksum 1511 10 common/cmd_bootm.c Ramdisk header is OK 1512 -12 common/cmd_bootm.c Ramdisk data has bad checksum 1513 11 common/cmd_bootm.c Ramdisk data has correct checksum 1514 12 common/cmd_bootm.c Ramdisk verification complete, start loading 1515 -13 common/cmd_bootm.c Wrong Image Type (not PPC Linux Ramdisk) 1516 13 common/cmd_bootm.c Start multifile image verification 1517 14 common/cmd_bootm.c No initial ramdisk, no multifile, continue. 1518 15 common/cmd_bootm.c All preparation done, transferring control to OS 1519 1520 -30 lib_ppc/board.c Fatal error, hang the system 1521 -31 post/post.c POST test failed, detected by post_output_backlog() 1522 -32 post/post.c POST test failed, detected by post_run_single() 1523 1524 -1 common/cmd_doc.c Bad usage of "doc" command 1525 -1 common/cmd_doc.c No boot device 1526 -1 common/cmd_doc.c Unknown Chip ID on boot device 1527 -1 common/cmd_doc.c Read Error on boot device 1528 -1 common/cmd_doc.c Image header has bad magic number 1529 1530 -1 common/cmd_ide.c Bad usage of "ide" command 1531 -1 common/cmd_ide.c No boot device 1532 -1 common/cmd_ide.c Unknown boot device 1533 -1 common/cmd_ide.c Unknown partition table 1534 -1 common/cmd_ide.c Invalid partition type 1535 -1 common/cmd_ide.c Read Error on boot device 1536 -1 common/cmd_ide.c Image header has bad magic number 1537 1538 -1 common/cmd_nand.c Bad usage of "nand" command 1539 -1 common/cmd_nand.c No boot device 1540 -1 common/cmd_nand.c Unknown Chip ID on boot device 1541 -1 common/cmd_nand.c Read Error on boot device 1542 -1 common/cmd_nand.c Image header has bad magic number 1543 1544 -1 common/env_common.c Environment has a bad CRC, using default 1545 1546 1547Modem Support: 1548-------------- 1549 1550[so far only for SMDK2400 and TRAB boards] 1551 1552- Modem support endable: 1553 CONFIG_MODEM_SUPPORT 1554 1555- RTS/CTS Flow control enable: 1556 CONFIG_HWFLOW 1557 1558- Modem debug support: 1559 CONFIG_MODEM_SUPPORT_DEBUG 1560 1561 Enables debugging stuff (char screen[1024], dbg()) 1562 for modem support. Useful only with BDI2000. 1563 1564- Interrupt support (PPC): 1565 1566 There are common interrupt_init() and timer_interrupt() 1567 for all PPC archs. interrupt_init() calls interrupt_init_cpu() 1568 for cpu specific initialization. interrupt_init_cpu() 1569 should set decrementer_count to appropriate value. If 1570 cpu resets decrementer automatically after interrupt 1571 (ppc4xx) it should set decrementer_count to zero. 1572 timer_interrupt() calls timer_interrupt_cpu() for cpu 1573 specific handling. If board has watchdog / status_led 1574 / other_activity_monitor it works automatically from 1575 general timer_interrupt(). 1576 1577- General: 1578 1579 In the target system modem support is enabled when a 1580 specific key (key combination) is pressed during 1581 power-on. Otherwise U-Boot will boot normally 1582 (autoboot). The key_pressed() fuction is called from 1583 board_init(). Currently key_pressed() is a dummy 1584 function, returning 1 and thus enabling modem 1585 initialization. 1586 1587 If there are no modem init strings in the 1588 environment, U-Boot proceed to autoboot; the 1589 previous output (banner, info printfs) will be 1590 supressed, though. 1591 1592 See also: doc/README.Modem 1593 1594 1595Configuration Settings: 1596----------------------- 1597 1598- CFG_LONGHELP: Defined when you want long help messages included; 1599 undefine this when you're short of memory. 1600 1601- CFG_PROMPT: This is what U-Boot prints on the console to 1602 prompt for user input. 1603 1604- CFG_CBSIZE: Buffer size for input from the Console 1605 1606- CFG_PBSIZE: Buffer size for Console output 1607 1608- CFG_MAXARGS: max. Number of arguments accepted for monitor commands 1609 1610- CFG_BARGSIZE: Buffer size for Boot Arguments which are passed to 1611 the application (usually a Linux kernel) when it is 1612 booted 1613 1614- CFG_BAUDRATE_TABLE: 1615 List of legal baudrate settings for this board. 1616 1617- CFG_CONSOLE_INFO_QUIET 1618 Suppress display of console information at boot. 1619 1620- CFG_CONSOLE_IS_IN_ENV 1621 If the board specific function 1622 extern int overwrite_console (void); 1623 returns 1, the stdin, stderr and stdout are switched to the 1624 serial port, else the settings in the environment are used. 1625 1626- CFG_CONSOLE_OVERWRITE_ROUTINE 1627 Enable the call to overwrite_console(). 1628 1629- CFG_CONSOLE_ENV_OVERWRITE 1630 Enable overwrite of previous console environment settings. 1631 1632- CFG_MEMTEST_START, CFG_MEMTEST_END: 1633 Begin and End addresses of the area used by the 1634 simple memory test. 1635 1636- CFG_ALT_MEMTEST: 1637 Enable an alternate, more extensive memory test. 1638 1639- CFG_MEMTEST_SCRATCH: 1640 Scratch address used by the alternate memory test 1641 You only need to set this if address zero isn't writeable 1642 1643- CFG_TFTP_LOADADDR: 1644 Default load address for network file downloads 1645 1646- CFG_LOADS_BAUD_CHANGE: 1647 Enable temporary baudrate change while serial download 1648 1649- CFG_SDRAM_BASE: 1650 Physical start address of SDRAM. _Must_ be 0 here. 1651 1652- CFG_MBIO_BASE: 1653 Physical start address of Motherboard I/O (if using a 1654 Cogent motherboard) 1655 1656- CFG_FLASH_BASE: 1657 Physical start address of Flash memory. 1658 1659- CFG_MONITOR_BASE: 1660 Physical start address of boot monitor code (set by 1661 make config files to be same as the text base address 1662 (TEXT_BASE) used when linking) - same as 1663 CFG_FLASH_BASE when booting from flash. 1664 1665- CFG_MONITOR_LEN: 1666 Size of memory reserved for monitor code, used to 1667 determine _at_compile_time_ (!) if the environment is 1668 embedded within the U-Boot image, or in a separate 1669 flash sector. 1670 1671- CFG_MALLOC_LEN: 1672 Size of DRAM reserved for malloc() use. 1673 1674- CFG_BOOTMAPSZ: 1675 Maximum size of memory mapped by the startup code of 1676 the Linux kernel; all data that must be processed by 1677 the Linux kernel (bd_info, boot arguments, eventually 1678 initrd image) must be put below this limit. 1679 1680- CFG_MAX_FLASH_BANKS: 1681 Max number of Flash memory banks 1682 1683- CFG_MAX_FLASH_SECT: 1684 Max number of sectors on a Flash chip 1685 1686- CFG_FLASH_ERASE_TOUT: 1687 Timeout for Flash erase operations (in ms) 1688 1689- CFG_FLASH_WRITE_TOUT: 1690 Timeout for Flash write operations (in ms) 1691 1692- CFG_FLASH_LOCK_TOUT 1693 Timeout for Flash set sector lock bit operation (in ms) 1694 1695- CFG_FLASH_UNLOCK_TOUT 1696 Timeout for Flash clear lock bits operation (in ms) 1697 1698- CFG_FLASH_PROTECTION 1699 If defined, hardware flash sectors protection is used 1700 instead of U-Boot software protection. 1701 1702- CFG_DIRECT_FLASH_TFTP: 1703 1704 Enable TFTP transfers directly to flash memory; 1705 without this option such a download has to be 1706 performed in two steps: (1) download to RAM, and (2) 1707 copy from RAM to flash. 1708 1709 The two-step approach is usually more reliable, since 1710 you can check if the download worked before you erase 1711 the flash, but in some situations (when sytem RAM is 1712 too limited to allow for a tempory copy of the 1713 downloaded image) this option may be very useful. 1714 1715- CFG_FLASH_CFI: 1716 Define if the flash driver uses extra elements in the 1717 common flash structure for storing flash geometry. 1718 1719- CFG_FLASH_CFI_DRIVER 1720 This option also enables the building of the cfi_flash driver 1721 in the drivers directory 1722 1723- CFG_RX_ETH_BUFFER: 1724 Defines the number of ethernet receive buffers. On some 1725 ethernet controllers it is recommended to set this value 1726 to 8 or even higher (EEPRO100 or 405 EMAC), since all 1727 buffers can be full shortly after enabling the interface 1728 on high ethernet traffic. 1729 Defaults to 4 if not defined. 1730 1731The following definitions that deal with the placement and management 1732of environment data (variable area); in general, we support the 1733following configurations: 1734 1735- CFG_ENV_IS_IN_FLASH: 1736 1737 Define this if the environment is in flash memory. 1738 1739 a) The environment occupies one whole flash sector, which is 1740 "embedded" in the text segment with the U-Boot code. This 1741 happens usually with "bottom boot sector" or "top boot 1742 sector" type flash chips, which have several smaller 1743 sectors at the start or the end. For instance, such a 1744 layout can have sector sizes of 8, 2x4, 16, Nx32 kB. In 1745 such a case you would place the environment in one of the 1746 4 kB sectors - with U-Boot code before and after it. With 1747 "top boot sector" type flash chips, you would put the 1748 environment in one of the last sectors, leaving a gap 1749 between U-Boot and the environment. 1750 1751 - CFG_ENV_OFFSET: 1752 1753 Offset of environment data (variable area) to the 1754 beginning of flash memory; for instance, with bottom boot 1755 type flash chips the second sector can be used: the offset 1756 for this sector is given here. 1757 1758 CFG_ENV_OFFSET is used relative to CFG_FLASH_BASE. 1759 1760 - CFG_ENV_ADDR: 1761 1762 This is just another way to specify the start address of 1763 the flash sector containing the environment (instead of 1764 CFG_ENV_OFFSET). 1765 1766 - CFG_ENV_SECT_SIZE: 1767 1768 Size of the sector containing the environment. 1769 1770 1771 b) Sometimes flash chips have few, equal sized, BIG sectors. 1772 In such a case you don't want to spend a whole sector for 1773 the environment. 1774 1775 - CFG_ENV_SIZE: 1776 1777 If you use this in combination with CFG_ENV_IS_IN_FLASH 1778 and CFG_ENV_SECT_SIZE, you can specify to use only a part 1779 of this flash sector for the environment. This saves 1780 memory for the RAM copy of the environment. 1781 1782 It may also save flash memory if you decide to use this 1783 when your environment is "embedded" within U-Boot code, 1784 since then the remainder of the flash sector could be used 1785 for U-Boot code. It should be pointed out that this is 1786 STRONGLY DISCOURAGED from a robustness point of view: 1787 updating the environment in flash makes it always 1788 necessary to erase the WHOLE sector. If something goes 1789 wrong before the contents has been restored from a copy in 1790 RAM, your target system will be dead. 1791 1792 - CFG_ENV_ADDR_REDUND 1793 CFG_ENV_SIZE_REDUND 1794 1795 These settings describe a second storage area used to hold 1796 a redundand copy of the environment data, so that there is 1797 a valid backup copy in case there is a power failure during 1798 a "saveenv" operation. 1799 1800BE CAREFUL! Any changes to the flash layout, and some changes to the 1801source code will make it necessary to adapt <board>/u-boot.lds* 1802accordingly! 1803 1804 1805- CFG_ENV_IS_IN_NVRAM: 1806 1807 Define this if you have some non-volatile memory device 1808 (NVRAM, battery buffered SRAM) which you want to use for the 1809 environment. 1810 1811 - CFG_ENV_ADDR: 1812 - CFG_ENV_SIZE: 1813 1814 These two #defines are used to determin the memory area you 1815 want to use for environment. It is assumed that this memory 1816 can just be read and written to, without any special 1817 provision. 1818 1819BE CAREFUL! The first access to the environment happens quite early 1820in U-Boot initalization (when we try to get the setting of for the 1821console baudrate). You *MUST* have mappend your NVRAM area then, or 1822U-Boot will hang. 1823 1824Please note that even with NVRAM we still use a copy of the 1825environment in RAM: we could work on NVRAM directly, but we want to 1826keep settings there always unmodified except somebody uses "saveenv" 1827to save the current settings. 1828 1829 1830- CFG_ENV_IS_IN_EEPROM: 1831 1832 Use this if you have an EEPROM or similar serial access 1833 device and a driver for it. 1834 1835 - CFG_ENV_OFFSET: 1836 - CFG_ENV_SIZE: 1837 1838 These two #defines specify the offset and size of the 1839 environment area within the total memory of your EEPROM. 1840 1841 - CFG_I2C_EEPROM_ADDR: 1842 If defined, specified the chip address of the EEPROM device. 1843 The default address is zero. 1844 1845 - CFG_EEPROM_PAGE_WRITE_BITS: 1846 If defined, the number of bits used to address bytes in a 1847 single page in the EEPROM device. A 64 byte page, for example 1848 would require six bits. 1849 1850 - CFG_EEPROM_PAGE_WRITE_DELAY_MS: 1851 If defined, the number of milliseconds to delay between 1852 page writes. The default is zero milliseconds. 1853 1854 - CFG_I2C_EEPROM_ADDR_LEN: 1855 The length in bytes of the EEPROM memory array address. Note 1856 that this is NOT the chip address length! 1857 1858 - CFG_I2C_EEPROM_ADDR_OVERFLOW: 1859 EEPROM chips that implement "address overflow" are ones 1860 like Catalyst 24WC04/08/16 which has 9/10/11 bits of 1861 address and the extra bits end up in the "chip address" bit 1862 slots. This makes a 24WC08 (1Kbyte) chip look like four 256 1863 byte chips. 1864 1865 Note that we consider the length of the address field to 1866 still be one byte because the extra address bits are hidden 1867 in the chip address. 1868 1869 - CFG_EEPROM_SIZE: 1870 The size in bytes of the EEPROM device. 1871 1872 1873- CFG_ENV_IS_IN_DATAFLASH: 1874 1875 Define this if you have a DataFlash memory device which you 1876 want to use for the environment. 1877 1878 - CFG_ENV_OFFSET: 1879 - CFG_ENV_ADDR: 1880 - CFG_ENV_SIZE: 1881 1882 These three #defines specify the offset and size of the 1883 environment area within the total memory of your DataFlash placed 1884 at the specified address. 1885 1886- CFG_ENV_IS_IN_NAND: 1887 1888 Define this if you have a NAND device which you want to use 1889 for the environment. 1890 1891 - CFG_ENV_OFFSET: 1892 - CFG_ENV_SIZE: 1893 1894 These two #defines specify the offset and size of the environment 1895 area within the first NAND device. 1896 1897- CFG_SPI_INIT_OFFSET 1898 1899 Defines offset to the initial SPI buffer area in DPRAM. The 1900 area is used at an early stage (ROM part) if the environment 1901 is configured to reside in the SPI EEPROM: We need a 520 byte 1902 scratch DPRAM area. It is used between the two initialization 1903 calls (spi_init_f() and spi_init_r()). A value of 0xB00 seems 1904 to be a good choice since it makes it far enough from the 1905 start of the data area as well as from the stack pointer. 1906 1907Please note that the environment is read-only as long as the monitor 1908has been relocated to RAM and a RAM copy of the environment has been 1909created; also, when using EEPROM you will have to use getenv_r() 1910until then to read environment variables. 1911 1912The environment is protected by a CRC32 checksum. Before the monitor 1913is relocated into RAM, as a result of a bad CRC you will be working 1914with the compiled-in default environment - *silently*!!! [This is 1915necessary, because the first environment variable we need is the 1916"baudrate" setting for the console - if we have a bad CRC, we don't 1917have any device yet where we could complain.] 1918 1919Note: once the monitor has been relocated, then it will complain if 1920the default environment is used; a new CRC is computed as soon as you 1921use the "saveenv" command to store a valid environment. 1922 1923- CFG_FAULT_ECHO_LINK_DOWN: 1924 Echo the inverted Ethernet link state to the fault LED. 1925 1926 Note: If this option is active, then CFG_FAULT_MII_ADDR 1927 also needs to be defined. 1928 1929- CFG_FAULT_MII_ADDR: 1930 MII address of the PHY to check for the Ethernet link state. 1931 1932- CFG_64BIT_VSPRINTF: 1933 Makes vsprintf (and all *printf functions) support printing 1934 of 64bit values by using the L quantifier 1935 1936- CFG_64BIT_STRTOUL: 1937 Adds simple_strtoull that returns a 64bit value 1938 1939Low Level (hardware related) configuration options: 1940--------------------------------------------------- 1941 1942- CFG_CACHELINE_SIZE: 1943 Cache Line Size of the CPU. 1944 1945- CFG_DEFAULT_IMMR: 1946 Default address of the IMMR after system reset. 1947 1948 Needed on some 8260 systems (MPC8260ADS, PQ2FADS-ZU, 1949 and RPXsuper) to be able to adjust the position of 1950 the IMMR register after a reset. 1951 1952- Floppy Disk Support: 1953 CFG_FDC_DRIVE_NUMBER 1954 1955 the default drive number (default value 0) 1956 1957 CFG_ISA_IO_STRIDE 1958 1959 defines the spacing between fdc chipset registers 1960 (default value 1) 1961 1962 CFG_ISA_IO_OFFSET 1963 1964 defines the offset of register from address. It 1965 depends on which part of the data bus is connected to 1966 the fdc chipset. (default value 0) 1967 1968 If CFG_ISA_IO_STRIDE CFG_ISA_IO_OFFSET and 1969 CFG_FDC_DRIVE_NUMBER are undefined, they take their 1970 default value. 1971 1972 if CFG_FDC_HW_INIT is defined, then the function 1973 fdc_hw_init() is called at the beginning of the FDC 1974 setup. fdc_hw_init() must be provided by the board 1975 source code. It is used to make hardware dependant 1976 initializations. 1977 1978- CFG_IMMR: Physical address of the Internal Memory Mapped 1979 Register; DO NOT CHANGE! (11-4) 1980 [MPC8xx systems only] 1981 1982- CFG_INIT_RAM_ADDR: 1983 1984 Start address of memory area that can be used for 1985 initial data and stack; please note that this must be 1986 writable memory that is working WITHOUT special 1987 initialization, i. e. you CANNOT use normal RAM which 1988 will become available only after programming the 1989 memory controller and running certain initialization 1990 sequences. 1991 1992 U-Boot uses the following memory types: 1993 - MPC8xx and MPC8260: IMMR (internal memory of the CPU) 1994 - MPC824X: data cache 1995 - PPC4xx: data cache 1996 1997- CFG_GBL_DATA_OFFSET: 1998 1999 Offset of the initial data structure in the memory 2000 area defined by CFG_INIT_RAM_ADDR. Usually 2001 CFG_GBL_DATA_OFFSET is chosen such that the initial 2002 data is located at the end of the available space 2003 (sometimes written as (CFG_INIT_RAM_END - 2004 CFG_INIT_DATA_SIZE), and the initial stack is just 2005 below that area (growing from (CFG_INIT_RAM_ADDR + 2006 CFG_GBL_DATA_OFFSET) downward. 2007 2008 Note: 2009 On the MPC824X (or other systems that use the data 2010 cache for initial memory) the address chosen for 2011 CFG_INIT_RAM_ADDR is basically arbitrary - it must 2012 point to an otherwise UNUSED address space between 2013 the top of RAM and the start of the PCI space. 2014 2015- CFG_SIUMCR: SIU Module Configuration (11-6) 2016 2017- CFG_SYPCR: System Protection Control (11-9) 2018 2019- CFG_TBSCR: Time Base Status and Control (11-26) 2020 2021- CFG_PISCR: Periodic Interrupt Status and Control (11-31) 2022 2023- CFG_PLPRCR: PLL, Low-Power, and Reset Control Register (15-30) 2024 2025- CFG_SCCR: System Clock and reset Control Register (15-27) 2026 2027- CFG_OR_TIMING_SDRAM: 2028 SDRAM timing 2029 2030- CFG_MAMR_PTA: 2031 periodic timer for refresh 2032 2033- CFG_DER: Debug Event Register (37-47) 2034 2035- FLASH_BASE0_PRELIM, FLASH_BASE1_PRELIM, CFG_REMAP_OR_AM, 2036 CFG_PRELIM_OR_AM, CFG_OR_TIMING_FLASH, CFG_OR0_REMAP, 2037 CFG_OR0_PRELIM, CFG_BR0_PRELIM, CFG_OR1_REMAP, CFG_OR1_PRELIM, 2038 CFG_BR1_PRELIM: 2039 Memory Controller Definitions: BR0/1 and OR0/1 (FLASH) 2040 2041- SDRAM_BASE2_PRELIM, SDRAM_BASE3_PRELIM, SDRAM_MAX_SIZE, 2042 CFG_OR_TIMING_SDRAM, CFG_OR2_PRELIM, CFG_BR2_PRELIM, 2043 CFG_OR3_PRELIM, CFG_BR3_PRELIM: 2044 Memory Controller Definitions: BR2/3 and OR2/3 (SDRAM) 2045 2046- CFG_MAMR_PTA, CFG_MPTPR_2BK_4K, CFG_MPTPR_1BK_4K, CFG_MPTPR_2BK_8K, 2047 CFG_MPTPR_1BK_8K, CFG_MAMR_8COL, CFG_MAMR_9COL: 2048 Machine Mode Register and Memory Periodic Timer 2049 Prescaler definitions (SDRAM timing) 2050 2051- CFG_I2C_UCODE_PATCH, CFG_I2C_DPMEM_OFFSET [0x1FC0]: 2052 enable I2C microcode relocation patch (MPC8xx); 2053 define relocation offset in DPRAM [DSP2] 2054 2055- CFG_SPI_UCODE_PATCH, CFG_SPI_DPMEM_OFFSET [0x1FC0]: 2056 enable SPI microcode relocation patch (MPC8xx); 2057 define relocation offset in DPRAM [SCC4] 2058 2059- CFG_USE_OSCCLK: 2060 Use OSCM clock mode on MBX8xx board. Be careful, 2061 wrong setting might damage your board. Read 2062 doc/README.MBX before setting this variable! 2063 2064- CFG_CPM_POST_WORD_ADDR: (MPC8xx, MPC8260 only) 2065 Offset of the bootmode word in DPRAM used by post 2066 (Power On Self Tests). This definition overrides 2067 #define'd default value in commproc.h resp. 2068 cpm_8260.h. 2069 2070- CFG_PCI_SLV_MEM_LOCAL, CFG_PCI_SLV_MEM_BUS, CFG_PICMR0_MASK_ATTRIB, 2071 CFG_PCI_MSTR0_LOCAL, CFG_PCIMSK0_MASK, CFG_PCI_MSTR1_LOCAL, 2072 CFG_PCIMSK1_MASK, CFG_PCI_MSTR_MEM_LOCAL, CFG_PCI_MSTR_MEM_BUS, 2073 CFG_CPU_PCI_MEM_START, CFG_PCI_MSTR_MEM_SIZE, CFG_POCMR0_MASK_ATTRIB, 2074 CFG_PCI_MSTR_MEMIO_LOCAL, CFG_PCI_MSTR_MEMIO_BUS, CPU_PCI_MEMIO_START, 2075 CFG_PCI_MSTR_MEMIO_SIZE, CFG_POCMR1_MASK_ATTRIB, CFG_PCI_MSTR_IO_LOCAL, 2076 CFG_PCI_MSTR_IO_BUS, CFG_CPU_PCI_IO_START, CFG_PCI_MSTR_IO_SIZE, 2077 CFG_POCMR2_MASK_ATTRIB: (MPC826x only) 2078 Overrides the default PCI memory map in cpu/mpc8260/pci.c if set. 2079 2080- CONFIG_ETHER_ON_FEC[12] 2081 Define to enable FEC[12] on a 8xx series processor. 2082 2083- CONFIG_FEC[12]_PHY 2084 Define to the hardcoded PHY address which corresponds 2085 to the given FEC; i. e. 2086 #define CONFIG_FEC1_PHY 4 2087 means that the PHY with address 4 is connected to FEC1 2088 2089 When set to -1, means to probe for first available. 2090 2091- CONFIG_FEC[12]_PHY_NORXERR 2092 The PHY does not have a RXERR line (RMII only). 2093 (so program the FEC to ignore it). 2094 2095- CONFIG_RMII 2096 Enable RMII mode for all FECs. 2097 Note that this is a global option, we can't 2098 have one FEC in standard MII mode and another in RMII mode. 2099 2100- CONFIG_CRC32_VERIFY 2101 Add a verify option to the crc32 command. 2102 The syntax is: 2103 2104 => crc32 -v <address> <count> <crc32> 2105 2106 Where address/count indicate a memory area 2107 and crc32 is the correct crc32 which the 2108 area should have. 2109 2110- CONFIG_LOOPW 2111 Add the "loopw" memory command. This only takes effect if 2112 the memory commands are activated globally (CFG_CMD_MEM). 2113 2114Building the Software: 2115====================== 2116 2117Building U-Boot has been tested in native PPC environments (on a 2118PowerBook G3 running LinuxPPC 2000) and in cross environments 2119(running RedHat 6.x and 7.x Linux on x86, Solaris 2.6 on a SPARC, and 2120NetBSD 1.5 on x86). 2121 2122If you are not using a native PPC environment, it is assumed that you 2123have the GNU cross compiling tools available in your path and named 2124with a prefix of "powerpc-linux-". If this is not the case, (e.g. if 2125you are using Monta Vista's Hard Hat Linux CDK 1.2) you must change 2126the definition of CROSS_COMPILE in Makefile. For HHL on a 4xx CPU, 2127change it to: 2128 2129 CROSS_COMPILE = ppc_4xx- 2130 2131 2132U-Boot is intended to be simple to build. After installing the 2133sources you must configure U-Boot for one specific board type. This 2134is done by typing: 2135 2136 make NAME_config 2137 2138where "NAME_config" is the name of one of the existing 2139configurations; the following names are supported: 2140 2141 ADCIOP_config FPS860L_config omap730p2_config 2142 ADS860_config GEN860T_config pcu_e_config 2143 AR405_config GENIETV_config PIP405_config 2144 at91rm9200dk_config GTH_config QS823_config 2145 CANBT_config hermes_config QS850_config 2146 cmi_mpc5xx_config hymod_config QS860T_config 2147 cogent_common_config IP860_config RPXlite_config 2148 cogent_mpc8260_config IVML24_config RPXlite_DW_config 2149 cogent_mpc8xx_config IVMS8_config RPXsuper_config 2150 CPCI405_config JSE_config rsdproto_config 2151 CPCIISER4_config LANTEC_config Sandpoint8240_config 2152 csb272_config lwmon_config sbc8260_config 2153 CU824_config MBX860T_config sbc8560_33_config 2154 DUET_ADS_config MBX_config sbc8560_66_config 2155 EBONY_config MPC8260ADS_config SM850_config 2156 ELPT860_config MPC8540ADS_config SPD823TS_config 2157 ESTEEM192E_config MPC8560ADS_config stxgp3_config 2158 ETX094_config NETVIA_config SXNI855T_config 2159 FADS823_config omap1510inn_config TQM823L_config 2160 FADS850SAR_config omap1610h2_config TQM850L_config 2161 FADS860T_config omap1610inn_config TQM855L_config 2162 FPS850L_config omap5912osk_config TQM860L_config 2163 WALNUT405_config 2164 ZPC1900_config 2165 2166Note: for some board special configuration names may exist; check if 2167 additional information is available from the board vendor; for 2168 instance, the TQM823L systems are available without (standard) 2169 or with LCD support. You can select such additional "features" 2170 when chosing the configuration, i. e. 2171 2172 make TQM823L_config 2173 - will configure for a plain TQM823L, i. e. no LCD support 2174 2175 make TQM823L_LCD_config 2176 - will configure for a TQM823L with U-Boot console on LCD 2177 2178 etc. 2179 2180 2181Finally, type "make all", and you should get some working U-Boot 2182images ready for download to / installation on your system: 2183 2184- "u-boot.bin" is a raw binary image 2185- "u-boot" is an image in ELF binary format 2186- "u-boot.srec" is in Motorola S-Record format 2187 2188 2189Please be aware that the Makefiles assume you are using GNU make, so 2190for instance on NetBSD you might need to use "gmake" instead of 2191native "make". 2192 2193 2194If the system board that you have is not listed, then you will need 2195to port U-Boot to your hardware platform. To do this, follow these 2196steps: 2197 21981. Add a new configuration option for your board to the toplevel 2199 "Makefile" and to the "MAKEALL" script, using the existing 2200 entries as examples. Note that here and at many other places 2201 boards and other names are listed in alphabetical sort order. Please 2202 keep this order. 22032. Create a new directory to hold your board specific code. Add any 2204 files you need. In your board directory, you will need at least 2205 the "Makefile", a "<board>.c", "flash.c" and "u-boot.lds". 22063. Create a new configuration file "include/configs/<board>.h" for 2207 your board 22083. If you're porting U-Boot to a new CPU, then also create a new 2209 directory to hold your CPU specific code. Add any files you need. 22104. Run "make <board>_config" with your new name. 22115. Type "make", and you should get a working "u-boot.srec" file 2212 to be installed on your target system. 22136. Debug and solve any problems that might arise. 2214 [Of course, this last step is much harder than it sounds.] 2215 2216 2217Testing of U-Boot Modifications, Ports to New Hardware, etc.: 2218============================================================== 2219 2220If you have modified U-Boot sources (for instance added a new board 2221or support for new devices, a new CPU, etc.) you are expected to 2222provide feedback to the other developers. The feedback normally takes 2223the form of a "patch", i. e. a context diff against a certain (latest 2224official or latest in CVS) version of U-Boot sources. 2225 2226But before you submit such a patch, please verify that your modifi- 2227cation did not break existing code. At least make sure that *ALL* of 2228the supported boards compile WITHOUT ANY compiler warnings. To do so, 2229just run the "MAKEALL" script, which will configure and build U-Boot 2230for ALL supported system. Be warned, this will take a while. You can 2231select which (cross) compiler to use by passing a `CROSS_COMPILE' 2232environment variable to the script, i. e. to use the cross tools from 2233MontaVista's Hard Hat Linux you can type 2234 2235 CROSS_COMPILE=ppc_8xx- MAKEALL 2236 2237or to build on a native PowerPC system you can type 2238 2239 CROSS_COMPILE=' ' MAKEALL 2240 2241See also "U-Boot Porting Guide" below. 2242 2243 2244Monitor Commands - Overview: 2245============================ 2246 2247go - start application at address 'addr' 2248run - run commands in an environment variable 2249bootm - boot application image from memory 2250bootp - boot image via network using BootP/TFTP protocol 2251tftpboot- boot image via network using TFTP protocol 2252 and env variables "ipaddr" and "serverip" 2253 (and eventually "gatewayip") 2254rarpboot- boot image via network using RARP/TFTP protocol 2255diskboot- boot from IDE devicebootd - boot default, i.e., run 'bootcmd' 2256loads - load S-Record file over serial line 2257loadb - load binary file over serial line (kermit mode) 2258md - memory display 2259mm - memory modify (auto-incrementing) 2260nm - memory modify (constant address) 2261mw - memory write (fill) 2262cp - memory copy 2263cmp - memory compare 2264crc32 - checksum calculation 2265imd - i2c memory display 2266imm - i2c memory modify (auto-incrementing) 2267inm - i2c memory modify (constant address) 2268imw - i2c memory write (fill) 2269icrc32 - i2c checksum calculation 2270iprobe - probe to discover valid I2C chip addresses 2271iloop - infinite loop on address range 2272isdram - print SDRAM configuration information 2273sspi - SPI utility commands 2274base - print or set address offset 2275printenv- print environment variables 2276setenv - set environment variables 2277saveenv - save environment variables to persistent storage 2278protect - enable or disable FLASH write protection 2279erase - erase FLASH memory 2280flinfo - print FLASH memory information 2281bdinfo - print Board Info structure 2282iminfo - print header information for application image 2283coninfo - print console devices and informations 2284ide - IDE sub-system 2285loop - infinite loop on address range 2286loopw - infinite write loop on address range 2287mtest - simple RAM test 2288icache - enable or disable instruction cache 2289dcache - enable or disable data cache 2290reset - Perform RESET of the CPU 2291echo - echo args to console 2292version - print monitor version 2293help - print online help 2294? - alias for 'help' 2295 2296 2297Monitor Commands - Detailed Description: 2298======================================== 2299 2300TODO. 2301 2302For now: just type "help <command>". 2303 2304 2305Environment Variables: 2306====================== 2307 2308U-Boot supports user configuration using Environment Variables which 2309can be made persistent by saving to Flash memory. 2310 2311Environment Variables are set using "setenv", printed using 2312"printenv", and saved to Flash using "saveenv". Using "setenv" 2313without a value can be used to delete a variable from the 2314environment. As long as you don't save the environment you are 2315working with an in-memory copy. In case the Flash area containing the 2316environment is erased by accident, a default environment is provided. 2317 2318Some configuration options can be set using Environment Variables: 2319 2320 baudrate - see CONFIG_BAUDRATE 2321 2322 bootdelay - see CONFIG_BOOTDELAY 2323 2324 bootcmd - see CONFIG_BOOTCOMMAND 2325 2326 bootargs - Boot arguments when booting an RTOS image 2327 2328 bootfile - Name of the image to load with TFTP 2329 2330 autoload - if set to "no" (any string beginning with 'n'), 2331 "bootp" will just load perform a lookup of the 2332 configuration from the BOOTP server, but not try to 2333 load any image using TFTP 2334 2335 autostart - if set to "yes", an image loaded using the "bootp", 2336 "rarpboot", "tftpboot" or "diskboot" commands will 2337 be automatically started (by internally calling 2338 "bootm") 2339 2340 If set to "no", a standalone image passed to the 2341 "bootm" command will be copied to the load address 2342 (and eventually uncompressed), but NOT be started. 2343 This can be used to load and uncompress arbitrary 2344 data. 2345 2346 i2cfast - (PPC405GP|PPC405EP only) 2347 if set to 'y' configures Linux I2C driver for fast 2348 mode (400kHZ). This environment variable is used in 2349 initialization code. So, for changes to be effective 2350 it must be saved and board must be reset. 2351 2352 initrd_high - restrict positioning of initrd images: 2353 If this variable is not set, initrd images will be 2354 copied to the highest possible address in RAM; this 2355 is usually what you want since it allows for 2356 maximum initrd size. If for some reason you want to 2357 make sure that the initrd image is loaded below the 2358 CFG_BOOTMAPSZ limit, you can set this environment 2359 variable to a value of "no" or "off" or "0". 2360 Alternatively, you can set it to a maximum upper 2361 address to use (U-Boot will still check that it 2362 does not overwrite the U-Boot stack and data). 2363 2364 For instance, when you have a system with 16 MB 2365 RAM, and want to reserve 4 MB from use by Linux, 2366 you can do this by adding "mem=12M" to the value of 2367 the "bootargs" variable. However, now you must make 2368 sure that the initrd image is placed in the first 2369 12 MB as well - this can be done with 2370 2371 setenv initrd_high 00c00000 2372 2373 If you set initrd_high to 0xFFFFFFFF, this is an 2374 indication to U-Boot that all addresses are legal 2375 for the Linux kernel, including addresses in flash 2376 memory. In this case U-Boot will NOT COPY the 2377 ramdisk at all. This may be useful to reduce the 2378 boot time on your system, but requires that this 2379 feature is supported by your Linux kernel. 2380 2381 ipaddr - IP address; needed for tftpboot command 2382 2383 loadaddr - Default load address for commands like "bootp", 2384 "rarpboot", "tftpboot", "loadb" or "diskboot" 2385 2386 loads_echo - see CONFIG_LOADS_ECHO 2387 2388 serverip - TFTP server IP address; needed for tftpboot command 2389 2390 bootretry - see CONFIG_BOOT_RETRY_TIME 2391 2392 bootdelaykey - see CONFIG_AUTOBOOT_DELAY_STR 2393 2394 bootstopkey - see CONFIG_AUTOBOOT_STOP_STR 2395 2396 ethprime - When CONFIG_NET_MULTI is enabled controls which 2397 interface is used first. 2398 2399 ethact - When CONFIG_NET_MULTI is enabled controls which 2400 interface is currently active. For example you 2401 can do the following 2402 2403 => setenv ethact FEC ETHERNET 2404 => ping 192.168.0.1 # traffic sent on FEC ETHERNET 2405 => setenv ethact SCC ETHERNET 2406 => ping 10.0.0.1 # traffic sent on SCC ETHERNET 2407 2408 netretry - When set to "no" each network operation will 2409 either succeed or fail without retrying. 2410 When set to "once" the network operation will 2411 fail when all the available network interfaces 2412 are tried once without success. 2413 Useful on scripts which control the retry operation 2414 themselves. 2415 2416 vlan - When set to a value < 4095 the traffic over 2417 ethernet is encapsulated/received over 802.1q 2418 VLAN tagged frames. 2419 2420The following environment variables may be used and automatically 2421updated by the network boot commands ("bootp" and "rarpboot"), 2422depending the information provided by your boot server: 2423 2424 bootfile - see above 2425 dnsip - IP address of your Domain Name Server 2426 dnsip2 - IP address of your secondary Domain Name Server 2427 gatewayip - IP address of the Gateway (Router) to use 2428 hostname - Target hostname 2429 ipaddr - see above 2430 netmask - Subnet Mask 2431 rootpath - Pathname of the root filesystem on the NFS server 2432 serverip - see above 2433 2434 2435There are two special Environment Variables: 2436 2437 serial# - contains hardware identification information such 2438 as type string and/or serial number 2439 ethaddr - Ethernet address 2440 2441These variables can be set only once (usually during manufacturing of 2442the board). U-Boot refuses to delete or overwrite these variables 2443once they have been set once. 2444 2445 2446Further special Environment Variables: 2447 2448 ver - Contains the U-Boot version string as printed 2449 with the "version" command. This variable is 2450 readonly (see CONFIG_VERSION_VARIABLE). 2451 2452 2453Please note that changes to some configuration parameters may take 2454only effect after the next boot (yes, that's just like Windoze :-). 2455 2456 2457Command Line Parsing: 2458===================== 2459 2460There are two different command line parsers available with U-Boot: 2461the old "simple" one, and the much more powerful "hush" shell: 2462 2463Old, simple command line parser: 2464-------------------------------- 2465 2466- supports environment variables (through setenv / saveenv commands) 2467- several commands on one line, separated by ';' 2468- variable substitution using "... $(name) ..." syntax 2469- special characters ('$', ';') can be escaped by prefixing with '\', 2470 for example: 2471 setenv bootcmd bootm \$(address) 2472- You can also escape text by enclosing in single apostrophes, for example: 2473 setenv addip 'setenv bootargs $bootargs ip=$ipaddr:$serverip:$gatewayip:$netmask:$hostname::off' 2474 2475Hush shell: 2476----------- 2477 2478- similar to Bourne shell, with control structures like 2479 if...then...else...fi, for...do...done; while...do...done, 2480 until...do...done, ... 2481- supports environment ("global") variables (through setenv / saveenv 2482 commands) and local shell variables (through standard shell syntax 2483 "name=value"); only environment variables can be used with "run" 2484 command 2485 2486General rules: 2487-------------- 2488 2489(1) If a command line (or an environment variable executed by a "run" 2490 command) contains several commands separated by semicolon, and 2491 one of these commands fails, then the remaining commands will be 2492 executed anyway. 2493 2494(2) If you execute several variables with one call to run (i. e. 2495 calling run with a list af variables as arguments), any failing 2496 command will cause "run" to terminate, i. e. the remaining 2497 variables are not executed. 2498 2499Note for Redundant Ethernet Interfaces: 2500======================================= 2501 2502Some boards come with redundant ethernet interfaces; U-Boot supports 2503such configurations and is capable of automatic selection of a 2504"working" interface when needed. MAC assignment works as follows: 2505 2506Network interfaces are numbered eth0, eth1, eth2, ... Corresponding 2507MAC addresses can be stored in the environment as "ethaddr" (=>eth0), 2508"eth1addr" (=>eth1), "eth2addr", ... 2509 2510If the network interface stores some valid MAC address (for instance 2511in SROM), this is used as default address if there is NO correspon- 2512ding setting in the environment; if the corresponding environment 2513variable is set, this overrides the settings in the card; that means: 2514 2515o If the SROM has a valid MAC address, and there is no address in the 2516 environment, the SROM's address is used. 2517 2518o If there is no valid address in the SROM, and a definition in the 2519 environment exists, then the value from the environment variable is 2520 used. 2521 2522o If both the SROM and the environment contain a MAC address, and 2523 both addresses are the same, this MAC address is used. 2524 2525o If both the SROM and the environment contain a MAC address, and the 2526 addresses differ, the value from the environment is used and a 2527 warning is printed. 2528 2529o If neither SROM nor the environment contain a MAC address, an error 2530 is raised. 2531 2532 2533Image Formats: 2534============== 2535 2536The "boot" commands of this monitor operate on "image" files which 2537can be basicly anything, preceeded by a special header; see the 2538definitions in include/image.h for details; basicly, the header 2539defines the following image properties: 2540 2541* Target Operating System (Provisions for OpenBSD, NetBSD, FreeBSD, 2542 4.4BSD, Linux, SVR4, Esix, Solaris, Irix, SCO, Dell, NCR, VxWorks, 2543 LynxOS, pSOS, QNX, RTEMS, ARTOS; 2544 Currently supported: Linux, NetBSD, VxWorks, QNX, RTEMS, ARTOS, LynxOS). 2545* Target CPU Architecture (Provisions for Alpha, ARM, Intel x86, 2546 IA64, MIPS, NIOS, PowerPC, IBM S390, SuperH, Sparc, Sparc 64 Bit; 2547 Currently supported: ARM, Intel x86, MIPS, NIOS, PowerPC). 2548* Compression Type (uncompressed, gzip, bzip2) 2549* Load Address 2550* Entry Point 2551* Image Name 2552* Image Timestamp 2553 2554The header is marked by a special Magic Number, and both the header 2555and the data portions of the image are secured against corruption by 2556CRC32 checksums. 2557 2558 2559Linux Support: 2560============== 2561 2562Although U-Boot should support any OS or standalone application 2563easily, the main focus has always been on Linux during the design of 2564U-Boot. 2565 2566U-Boot includes many features that so far have been part of some 2567special "boot loader" code within the Linux kernel. Also, any 2568"initrd" images to be used are no longer part of one big Linux image; 2569instead, kernel and "initrd" are separate images. This implementation 2570serves several purposes: 2571 2572- the same features can be used for other OS or standalone 2573 applications (for instance: using compressed images to reduce the 2574 Flash memory footprint) 2575 2576- it becomes much easier to port new Linux kernel versions because 2577 lots of low-level, hardware dependent stuff are done by U-Boot 2578 2579- the same Linux kernel image can now be used with different "initrd" 2580 images; of course this also means that different kernel images can 2581 be run with the same "initrd". This makes testing easier (you don't 2582 have to build a new "zImage.initrd" Linux image when you just 2583 change a file in your "initrd"). Also, a field-upgrade of the 2584 software is easier now. 2585 2586 2587Linux HOWTO: 2588============ 2589 2590Porting Linux to U-Boot based systems: 2591--------------------------------------- 2592 2593U-Boot cannot save you from doing all the necessary modifications to 2594configure the Linux device drivers for use with your target hardware 2595(no, we don't intend to provide a full virtual machine interface to 2596Linux :-). 2597 2598But now you can ignore ALL boot loader code (in arch/ppc/mbxboot). 2599 2600Just make sure your machine specific header file (for instance 2601include/asm-ppc/tqm8xx.h) includes the same definition of the Board 2602Information structure as we define in include/u-boot.h, and make 2603sure that your definition of IMAP_ADDR uses the same value as your 2604U-Boot configuration in CFG_IMMR. 2605 2606 2607Configuring the Linux kernel: 2608----------------------------- 2609 2610No specific requirements for U-Boot. Make sure you have some root 2611device (initial ramdisk, NFS) for your target system. 2612 2613 2614Building a Linux Image: 2615----------------------- 2616 2617With U-Boot, "normal" build targets like "zImage" or "bzImage" are 2618not used. If you use recent kernel source, a new build target 2619"uImage" will exist which automatically builds an image usable by 2620U-Boot. Most older kernels also have support for a "pImage" target, 2621which was introduced for our predecessor project PPCBoot and uses a 2622100% compatible format. 2623 2624Example: 2625 2626 make TQM850L_config 2627 make oldconfig 2628 make dep 2629 make uImage 2630 2631The "uImage" build target uses a special tool (in 'tools/mkimage') to 2632encapsulate a compressed Linux kernel image with header information, 2633CRC32 checksum etc. for use with U-Boot. This is what we are doing: 2634 2635* build a standard "vmlinux" kernel image (in ELF binary format): 2636 2637* convert the kernel into a raw binary image: 2638 2639 ${CROSS_COMPILE}-objcopy -O binary \ 2640 -R .note -R .comment \ 2641 -S vmlinux linux.bin 2642 2643* compress the binary image: 2644 2645 gzip -9 linux.bin 2646 2647* package compressed binary image for U-Boot: 2648 2649 mkimage -A ppc -O linux -T kernel -C gzip \ 2650 -a 0 -e 0 -n "Linux Kernel Image" \ 2651 -d linux.bin.gz uImage 2652 2653 2654The "mkimage" tool can also be used to create ramdisk images for use 2655with U-Boot, either separated from the Linux kernel image, or 2656combined into one file. "mkimage" encapsulates the images with a 64 2657byte header containing information about target architecture, 2658operating system, image type, compression method, entry points, time 2659stamp, CRC32 checksums, etc. 2660 2661"mkimage" can be called in two ways: to verify existing images and 2662print the header information, or to build new images. 2663 2664In the first form (with "-l" option) mkimage lists the information 2665contained in the header of an existing U-Boot image; this includes 2666checksum verification: 2667 2668 tools/mkimage -l image 2669 -l ==> list image header information 2670 2671The second form (with "-d" option) is used to build a U-Boot image 2672from a "data file" which is used as image payload: 2673 2674 tools/mkimage -A arch -O os -T type -C comp -a addr -e ep \ 2675 -n name -d data_file image 2676 -A ==> set architecture to 'arch' 2677 -O ==> set operating system to 'os' 2678 -T ==> set image type to 'type' 2679 -C ==> set compression type 'comp' 2680 -a ==> set load address to 'addr' (hex) 2681 -e ==> set entry point to 'ep' (hex) 2682 -n ==> set image name to 'name' 2683 -d ==> use image data from 'datafile' 2684 2685Right now, all Linux kernels for PowerPC systems use the same load 2686address (0x00000000), but the entry point address depends on the 2687kernel version: 2688 2689- 2.2.x kernels have the entry point at 0x0000000C, 2690- 2.3.x and later kernels have the entry point at 0x00000000. 2691 2692So a typical call to build a U-Boot image would read: 2693 2694 -> tools/mkimage -n '2.4.4 kernel for TQM850L' \ 2695 > -A ppc -O linux -T kernel -C gzip -a 0 -e 0 \ 2696 > -d /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/ppc/coffboot/vmlinux.gz \ 2697 > examples/uImage.TQM850L 2698 Image Name: 2.4.4 kernel for TQM850L 2699 Created: Wed Jul 19 02:34:59 2000 2700 Image Type: PowerPC Linux Kernel Image (gzip compressed) 2701 Data Size: 335725 Bytes = 327.86 kB = 0.32 MB 2702 Load Address: 0x00000000 2703 Entry Point: 0x00000000 2704 2705To verify the contents of the image (or check for corruption): 2706 2707 -> tools/mkimage -l examples/uImage.TQM850L 2708 Image Name: 2.4.4 kernel for TQM850L 2709 Created: Wed Jul 19 02:34:59 2000 2710 Image Type: PowerPC Linux Kernel Image (gzip compressed) 2711 Data Size: 335725 Bytes = 327.86 kB = 0.32 MB 2712 Load Address: 0x00000000 2713 Entry Point: 0x00000000 2714 2715NOTE: for embedded systems where boot time is critical you can trade 2716speed for memory and install an UNCOMPRESSED image instead: this 2717needs more space in Flash, but boots much faster since it does not 2718need to be uncompressed: 2719 2720 -> gunzip /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/ppc/coffboot/vmlinux.gz 2721 -> tools/mkimage -n '2.4.4 kernel for TQM850L' \ 2722 > -A ppc -O linux -T kernel -C none -a 0 -e 0 \ 2723 > -d /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/ppc/coffboot/vmlinux \ 2724 > examples/uImage.TQM850L-uncompressed 2725 Image Name: 2.4.4 kernel for TQM850L 2726 Created: Wed Jul 19 02:34:59 2000 2727 Image Type: PowerPC Linux Kernel Image (uncompressed) 2728 Data Size: 792160 Bytes = 773.59 kB = 0.76 MB 2729 Load Address: 0x00000000 2730 Entry Point: 0x00000000 2731 2732 2733Similar you can build U-Boot images from a 'ramdisk.image.gz' file 2734when your kernel is intended to use an initial ramdisk: 2735 2736 -> tools/mkimage -n 'Simple Ramdisk Image' \ 2737 > -A ppc -O linux -T ramdisk -C gzip \ 2738 > -d /LinuxPPC/images/SIMPLE-ramdisk.image.gz examples/simple-initrd 2739 Image Name: Simple Ramdisk Image 2740 Created: Wed Jan 12 14:01:50 2000 2741 Image Type: PowerPC Linux RAMDisk Image (gzip compressed) 2742 Data Size: 566530 Bytes = 553.25 kB = 0.54 MB 2743 Load Address: 0x00000000 2744 Entry Point: 0x00000000 2745 2746 2747Installing a Linux Image: 2748------------------------- 2749 2750To downloading a U-Boot image over the serial (console) interface, 2751you must convert the image to S-Record format: 2752 2753 objcopy -I binary -O srec examples/image examples/image.srec 2754 2755The 'objcopy' does not understand the information in the U-Boot 2756image header, so the resulting S-Record file will be relative to 2757address 0x00000000. To load it to a given address, you need to 2758specify the target address as 'offset' parameter with the 'loads' 2759command. 2760 2761Example: install the image to address 0x40100000 (which on the 2762TQM8xxL is in the first Flash bank): 2763 2764 => erase 40100000 401FFFFF 2765 2766 .......... done 2767 Erased 8 sectors 2768 2769 => loads 40100000 2770 ## Ready for S-Record download ... 2771 ~>examples/image.srec 2772 1 2 3 4 5 6 7 8 9 10 11 12 13 ... 2773 ... 2774 15989 15990 15991 15992 2775 [file transfer complete] 2776 [connected] 2777 ## Start Addr = 0x00000000 2778 2779 2780You can check the success of the download using the 'iminfo' command; 2781this includes a checksum verification so you can be sure no data 2782corruption happened: 2783 2784 => imi 40100000 2785 2786 ## Checking Image at 40100000 ... 2787 Image Name: 2.2.13 for initrd on TQM850L 2788 Image Type: PowerPC Linux Kernel Image (gzip compressed) 2789 Data Size: 335725 Bytes = 327 kB = 0 MB 2790 Load Address: 00000000 2791 Entry Point: 0000000c 2792 Verifying Checksum ... OK 2793 2794 2795Boot Linux: 2796----------- 2797 2798The "bootm" command is used to boot an application that is stored in 2799memory (RAM or Flash). In case of a Linux kernel image, the contents 2800of the "bootargs" environment variable is passed to the kernel as 2801parameters. You can check and modify this variable using the 2802"printenv" and "setenv" commands: 2803 2804 2805 => printenv bootargs 2806 bootargs=root=/dev/ram 2807 2808 => setenv bootargs root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2 2809 2810 => printenv bootargs 2811 bootargs=root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2 2812 2813 => bootm 40020000 2814 ## Booting Linux kernel at 40020000 ... 2815 Image Name: 2.2.13 for NFS on TQM850L 2816 Image Type: PowerPC Linux Kernel Image (gzip compressed) 2817 Data Size: 381681 Bytes = 372 kB = 0 MB 2818 Load Address: 00000000 2819 Entry Point: 0000000c 2820 Verifying Checksum ... OK 2821 Uncompressing Kernel Image ... OK 2822 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 2823 Boot arguments: root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2 2824 time_init: decrementer frequency = 187500000/60 2825 Calibrating delay loop... 49.77 BogoMIPS 2826 Memory: 15208k available (700k kernel code, 444k data, 32k init) [c0000000,c1000000] 2827 ... 2828 2829If you want to boot a Linux kernel with initial ram disk, you pass 2830the memory addresses of both the kernel and the initrd image (PPBCOOT 2831format!) to the "bootm" command: 2832 2833 => imi 40100000 40200000 2834 2835 ## Checking Image at 40100000 ... 2836 Image Name: 2.2.13 for initrd on TQM850L 2837 Image Type: PowerPC Linux Kernel Image (gzip compressed) 2838 Data Size: 335725 Bytes = 327 kB = 0 MB 2839 Load Address: 00000000 2840 Entry Point: 0000000c 2841 Verifying Checksum ... OK 2842 2843 ## Checking Image at 40200000 ... 2844 Image Name: Simple Ramdisk Image 2845 Image Type: PowerPC Linux RAMDisk Image (gzip compressed) 2846 Data Size: 566530 Bytes = 553 kB = 0 MB 2847 Load Address: 00000000 2848 Entry Point: 00000000 2849 Verifying Checksum ... OK 2850 2851 => bootm 40100000 40200000 2852 ## Booting Linux kernel at 40100000 ... 2853 Image Name: 2.2.13 for initrd on TQM850L 2854 Image Type: PowerPC Linux Kernel Image (gzip compressed) 2855 Data Size: 335725 Bytes = 327 kB = 0 MB 2856 Load Address: 00000000 2857 Entry Point: 0000000c 2858 Verifying Checksum ... OK 2859 Uncompressing Kernel Image ... OK 2860 ## Loading RAMDisk Image at 40200000 ... 2861 Image Name: Simple Ramdisk Image 2862 Image Type: PowerPC Linux RAMDisk Image (gzip compressed) 2863 Data Size: 566530 Bytes = 553 kB = 0 MB 2864 Load Address: 00000000 2865 Entry Point: 00000000 2866 Verifying Checksum ... OK 2867 Loading Ramdisk ... OK 2868 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 2869 Boot arguments: root=/dev/ram 2870 time_init: decrementer frequency = 187500000/60 2871 Calibrating delay loop... 49.77 BogoMIPS 2872 ... 2873 RAMDISK: Compressed image found at block 0 2874 VFS: Mounted root (ext2 filesystem). 2875 2876 bash# 2877 2878More About U-Boot Image Types: 2879------------------------------ 2880 2881U-Boot supports the following image types: 2882 2883 "Standalone Programs" are directly runnable in the environment 2884 provided by U-Boot; it is expected that (if they behave 2885 well) you can continue to work in U-Boot after return from 2886 the Standalone Program. 2887 "OS Kernel Images" are usually images of some Embedded OS which 2888 will take over control completely. Usually these programs 2889 will install their own set of exception handlers, device 2890 drivers, set up the MMU, etc. - this means, that you cannot 2891 expect to re-enter U-Boot except by resetting the CPU. 2892 "RAMDisk Images" are more or less just data blocks, and their 2893 parameters (address, size) are passed to an OS kernel that is 2894 being started. 2895 "Multi-File Images" contain several images, typically an OS 2896 (Linux) kernel image and one or more data images like 2897 RAMDisks. This construct is useful for instance when you want 2898 to boot over the network using BOOTP etc., where the boot 2899 server provides just a single image file, but you want to get 2900 for instance an OS kernel and a RAMDisk image. 2901 2902 "Multi-File Images" start with a list of image sizes, each 2903 image size (in bytes) specified by an "uint32_t" in network 2904 byte order. This list is terminated by an "(uint32_t)0". 2905 Immediately after the terminating 0 follow the images, one by 2906 one, all aligned on "uint32_t" boundaries (size rounded up to 2907 a multiple of 4 bytes). 2908 2909 "Firmware Images" are binary images containing firmware (like 2910 U-Boot or FPGA images) which usually will be programmed to 2911 flash memory. 2912 2913 "Script files" are command sequences that will be executed by 2914 U-Boot's command interpreter; this feature is especially 2915 useful when you configure U-Boot to use a real shell (hush) 2916 as command interpreter. 2917 2918 2919Standalone HOWTO: 2920================= 2921 2922One of the features of U-Boot is that you can dynamically load and 2923run "standalone" applications, which can use some resources of 2924U-Boot like console I/O functions or interrupt services. 2925 2926Two simple examples are included with the sources: 2927 2928"Hello World" Demo: 2929------------------- 2930 2931'examples/hello_world.c' contains a small "Hello World" Demo 2932application; it is automatically compiled when you build U-Boot. 2933It's configured to run at address 0x00040004, so you can play with it 2934like that: 2935 2936 => loads 2937 ## Ready for S-Record download ... 2938 ~>examples/hello_world.srec 2939 1 2 3 4 5 6 7 8 9 10 11 ... 2940 [file transfer complete] 2941 [connected] 2942 ## Start Addr = 0x00040004 2943 2944 => go 40004 Hello World! This is a test. 2945 ## Starting application at 0x00040004 ... 2946 Hello World 2947 argc = 7 2948 argv[0] = "40004" 2949 argv[1] = "Hello" 2950 argv[2] = "World!" 2951 argv[3] = "This" 2952 argv[4] = "is" 2953 argv[5] = "a" 2954 argv[6] = "test." 2955 argv[7] = "<NULL>" 2956 Hit any key to exit ... 2957 2958 ## Application terminated, rc = 0x0 2959 2960Another example, which demonstrates how to register a CPM interrupt 2961handler with the U-Boot code, can be found in 'examples/timer.c'. 2962Here, a CPM timer is set up to generate an interrupt every second. 2963The interrupt service routine is trivial, just printing a '.' 2964character, but this is just a demo program. The application can be 2965controlled by the following keys: 2966 2967 ? - print current values og the CPM Timer registers 2968 b - enable interrupts and start timer 2969 e - stop timer and disable interrupts 2970 q - quit application 2971 2972 => loads 2973 ## Ready for S-Record download ... 2974 ~>examples/timer.srec 2975 1 2 3 4 5 6 7 8 9 10 11 ... 2976 [file transfer complete] 2977 [connected] 2978 ## Start Addr = 0x00040004 2979 2980 => go 40004 2981 ## Starting application at 0x00040004 ... 2982 TIMERS=0xfff00980 2983 Using timer 1 2984 tgcr @ 0xfff00980, tmr @ 0xfff00990, trr @ 0xfff00994, tcr @ 0xfff00998, tcn @ 0xfff0099c, ter @ 0xfff009b0 2985 2986Hit 'b': 2987 [q, b, e, ?] Set interval 1000000 us 2988 Enabling timer 2989Hit '?': 2990 [q, b, e, ?] ........ 2991 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0xef6, ter=0x0 2992Hit '?': 2993 [q, b, e, ?] . 2994 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x2ad4, ter=0x0 2995Hit '?': 2996 [q, b, e, ?] . 2997 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x1efc, ter=0x0 2998Hit '?': 2999 [q, b, e, ?] . 3000 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x169d, ter=0x0 3001Hit 'e': 3002 [q, b, e, ?] ...Stopping timer 3003Hit 'q': 3004 [q, b, e, ?] ## Application terminated, rc = 0x0 3005 3006 3007Minicom warning: 3008================ 3009 3010Over time, many people have reported problems when trying to use the 3011"minicom" terminal emulation program for serial download. I (wd) 3012consider minicom to be broken, and recommend not to use it. Under 3013Unix, I recommend to use C-Kermit for general purpose use (and 3014especially for kermit binary protocol download ("loadb" command), and 3015use "cu" for S-Record download ("loads" command). 3016 3017Nevertheless, if you absolutely want to use it try adding this 3018configuration to your "File transfer protocols" section: 3019 3020 Name Program Name U/D FullScr IO-Red. Multi 3021 X kermit /usr/bin/kermit -i -l %l -s Y U Y N N 3022 Y kermit /usr/bin/kermit -i -l %l -r N D Y N N 3023 3024 3025NetBSD Notes: 3026============= 3027 3028Starting at version 0.9.2, U-Boot supports NetBSD both as host 3029(build U-Boot) and target system (boots NetBSD/mpc8xx). 3030 3031Building requires a cross environment; it is known to work on 3032NetBSD/i386 with the cross-powerpc-netbsd-1.3 package (you will also 3033need gmake since the Makefiles are not compatible with BSD make). 3034Note that the cross-powerpc package does not install include files; 3035attempting to build U-Boot will fail because <machine/ansi.h> is 3036missing. This file has to be installed and patched manually: 3037 3038 # cd /usr/pkg/cross/powerpc-netbsd/include 3039 # mkdir powerpc 3040 # ln -s powerpc machine 3041 # cp /usr/src/sys/arch/powerpc/include/ansi.h powerpc/ansi.h 3042 # ${EDIT} powerpc/ansi.h ## must remove __va_list, _BSD_VA_LIST 3043 3044Native builds *don't* work due to incompatibilities between native 3045and U-Boot include files. 3046 3047Booting assumes that (the first part of) the image booted is a 3048stage-2 loader which in turn loads and then invokes the kernel 3049proper. Loader sources will eventually appear in the NetBSD source 3050tree (probably in sys/arc/mpc8xx/stand/u-boot_stage2/); in the 3051meantime, send mail to bruno@exet-ag.de and/or wd@denx.de for 3052details. 3053 3054 3055Implementation Internals: 3056========================= 3057 3058The following is not intended to be a complete description of every 3059implementation detail. However, it should help to understand the 3060inner workings of U-Boot and make it easier to port it to custom 3061hardware. 3062 3063 3064Initial Stack, Global Data: 3065--------------------------- 3066 3067The implementation of U-Boot is complicated by the fact that U-Boot 3068starts running out of ROM (flash memory), usually without access to 3069system RAM (because the memory controller is not initialized yet). 3070This means that we don't have writable Data or BSS segments, and BSS 3071is not initialized as zero. To be able to get a C environment working 3072at all, we have to allocate at least a minimal stack. Implementation 3073options for this are defined and restricted by the CPU used: Some CPU 3074models provide on-chip memory (like the IMMR area on MPC8xx and 3075MPC826x processors), on others (parts of) the data cache can be 3076locked as (mis-) used as memory, etc. 3077 3078 Chris Hallinan posted a good summary of these issues to the 3079 u-boot-users mailing list: 3080 3081 Subject: RE: [U-Boot-Users] RE: More On Memory Bank x (nothingness)? 3082 From: "Chris Hallinan" <clh@net1plus.com> 3083 Date: Mon, 10 Feb 2003 16:43:46 -0500 (22:43 MET) 3084 ... 3085 3086 Correct me if I'm wrong, folks, but the way I understand it 3087 is this: Using DCACHE as initial RAM for Stack, etc, does not 3088 require any physical RAM backing up the cache. The cleverness 3089 is that the cache is being used as a temporary supply of 3090 necessary storage before the SDRAM controller is setup. It's 3091 beyond the scope of this list to expain the details, but you 3092 can see how this works by studying the cache architecture and 3093 operation in the architecture and processor-specific manuals. 3094 3095 OCM is On Chip Memory, which I believe the 405GP has 4K. It 3096 is another option for the system designer to use as an 3097 initial stack/ram area prior to SDRAM being available. Either 3098 option should work for you. Using CS 4 should be fine if your 3099 board designers haven't used it for something that would 3100 cause you grief during the initial boot! It is frequently not 3101 used. 3102 3103 CFG_INIT_RAM_ADDR should be somewhere that won't interfere 3104 with your processor/board/system design. The default value 3105 you will find in any recent u-boot distribution in 3106 Walnut405.h should work for you. I'd set it to a value larger 3107 than your SDRAM module. If you have a 64MB SDRAM module, set 3108 it above 400_0000. Just make sure your board has no resources 3109 that are supposed to respond to that address! That code in 3110 start.S has been around a while and should work as is when 3111 you get the config right. 3112 3113 -Chris Hallinan 3114 DS4.COM, Inc. 3115 3116It is essential to remember this, since it has some impact on the C 3117code for the initialization procedures: 3118 3119* Initialized global data (data segment) is read-only. Do not attempt 3120 to write it. 3121 3122* Do not use any unitialized global data (or implicitely initialized 3123 as zero data - BSS segment) at all - this is undefined, initiali- 3124 zation is performed later (when relocating to RAM). 3125 3126* Stack space is very limited. Avoid big data buffers or things like 3127 that. 3128 3129Having only the stack as writable memory limits means we cannot use 3130normal global data to share information beween the code. But it 3131turned out that the implementation of U-Boot can be greatly 3132simplified by making a global data structure (gd_t) available to all 3133functions. We could pass a pointer to this data as argument to _all_ 3134functions, but this would bloat the code. Instead we use a feature of 3135the GCC compiler (Global Register Variables) to share the data: we 3136place a pointer (gd) to the global data into a register which we 3137reserve for this purpose. 3138 3139When choosing a register for such a purpose we are restricted by the 3140relevant (E)ABI specifications for the current architecture, and by 3141GCC's implementation. 3142 3143For PowerPC, the following registers have specific use: 3144 R1: stack pointer 3145 R2: TOC pointer 3146 R3-R4: parameter passing and return values 3147 R5-R10: parameter passing 3148 R13: small data area pointer 3149 R30: GOT pointer 3150 R31: frame pointer 3151 3152 (U-Boot also uses R14 as internal GOT pointer.) 3153 3154 ==> U-Boot will use R29 to hold a pointer to the global data 3155 3156 Note: on PPC, we could use a static initializer (since the 3157 address of the global data structure is known at compile time), 3158 but it turned out that reserving a register results in somewhat 3159 smaller code - although the code savings are not that big (on 3160 average for all boards 752 bytes for the whole U-Boot image, 3161 624 text + 127 data). 3162 3163On ARM, the following registers are used: 3164 3165 R0: function argument word/integer result 3166 R1-R3: function argument word 3167 R9: GOT pointer 3168 R10: stack limit (used only if stack checking if enabled) 3169 R11: argument (frame) pointer 3170 R12: temporary workspace 3171 R13: stack pointer 3172 R14: link register 3173 R15: program counter 3174 3175 ==> U-Boot will use R8 to hold a pointer to the global data 3176 3177 3178Memory Management: 3179------------------ 3180 3181U-Boot runs in system state and uses physical addresses, i.e. the 3182MMU is not used either for address mapping nor for memory protection. 3183 3184The available memory is mapped to fixed addresses using the memory 3185controller. In this process, a contiguous block is formed for each 3186memory type (Flash, SDRAM, SRAM), even when it consists of several 3187physical memory banks. 3188 3189U-Boot is installed in the first 128 kB of the first Flash bank (on 3190TQM8xxL modules this is the range 0x40000000 ... 0x4001FFFF). After 3191booting and sizing and initializing DRAM, the code relocates itself 3192to the upper end of DRAM. Immediately below the U-Boot code some 3193memory is reserved for use by malloc() [see CFG_MALLOC_LEN 3194configuration setting]. Below that, a structure with global Board 3195Info data is placed, followed by the stack (growing downward). 3196 3197Additionally, some exception handler code is copied to the low 8 kB 3198of DRAM (0x00000000 ... 0x00001FFF). 3199 3200So a typical memory configuration with 16 MB of DRAM could look like 3201this: 3202 3203 0x0000 0000 Exception Vector code 3204 : 3205 0x0000 1FFF 3206 0x0000 2000 Free for Application Use 3207 : 3208 : 3209 3210 : 3211 : 3212 0x00FB FF20 Monitor Stack (Growing downward) 3213 0x00FB FFAC Board Info Data and permanent copy of global data 3214 0x00FC 0000 Malloc Arena 3215 : 3216 0x00FD FFFF 3217 0x00FE 0000 RAM Copy of Monitor Code 3218 ... eventually: LCD or video framebuffer 3219 ... eventually: pRAM (Protected RAM - unchanged by reset) 3220 0x00FF FFFF [End of RAM] 3221 3222 3223System Initialization: 3224---------------------- 3225 3226In the reset configuration, U-Boot starts at the reset entry point 3227(on most PowerPC systens at address 0x00000100). Because of the reset 3228configuration for CS0# this is a mirror of the onboard Flash memory. 3229To be able to re-map memory U-Boot then jumps to its link address. 3230To be able to implement the initialization code in C, a (small!) 3231initial stack is set up in the internal Dual Ported RAM (in case CPUs 3232which provide such a feature like MPC8xx or MPC8260), or in a locked 3233part of the data cache. After that, U-Boot initializes the CPU core, 3234the caches and the SIU. 3235 3236Next, all (potentially) available memory banks are mapped using a 3237preliminary mapping. For example, we put them on 512 MB boundaries 3238(multiples of 0x20000000: SDRAM on 0x00000000 and 0x20000000, Flash 3239on 0x40000000 and 0x60000000, SRAM on 0x80000000). Then UPM A is 3240programmed for SDRAM access. Using the temporary configuration, a 3241simple memory test is run that determines the size of the SDRAM 3242banks. 3243 3244When there is more than one SDRAM bank, and the banks are of 3245different size, the largest is mapped first. For equal size, the first 3246bank (CS2#) is mapped first. The first mapping is always for address 32470x00000000, with any additional banks following immediately to create 3248contiguous memory starting from 0. 3249 3250Then, the monitor installs itself at the upper end of the SDRAM area 3251and allocates memory for use by malloc() and for the global Board 3252Info data; also, the exception vector code is copied to the low RAM 3253pages, and the final stack is set up. 3254 3255Only after this relocation will you have a "normal" C environment; 3256until that you are restricted in several ways, mostly because you are 3257running from ROM, and because the code will have to be relocated to a 3258new address in RAM. 3259 3260 3261U-Boot Porting Guide: 3262---------------------- 3263 3264[Based on messages by Jerry Van Baren in the U-Boot-Users mailing 3265list, October 2002] 3266 3267 3268int main (int argc, char *argv[]) 3269{ 3270 sighandler_t no_more_time; 3271 3272 signal (SIGALRM, no_more_time); 3273 alarm (PROJECT_DEADLINE - toSec (3 * WEEK)); 3274 3275 if (available_money > available_manpower) { 3276 pay consultant to port U-Boot; 3277 return 0; 3278 } 3279 3280 Download latest U-Boot source; 3281 3282 Subscribe to u-boot-users mailing list; 3283 3284 if (clueless) { 3285 email ("Hi, I am new to U-Boot, how do I get started?"); 3286 } 3287 3288 while (learning) { 3289 Read the README file in the top level directory; 3290 Read http://www.denx.de/twiki/bin/view/DULG/Manual ; 3291 Read the source, Luke; 3292 } 3293 3294 if (available_money > toLocalCurrency ($2500)) { 3295 Buy a BDI2000; 3296 } else { 3297 Add a lot of aggravation and time; 3298 } 3299 3300 Create your own board support subdirectory; 3301 3302 Create your own board config file; 3303 3304 while (!running) { 3305 do { 3306 Add / modify source code; 3307 } until (compiles); 3308 Debug; 3309 if (clueless) 3310 email ("Hi, I am having problems..."); 3311 } 3312 Send patch file to Wolfgang; 3313 3314 return 0; 3315} 3316 3317void no_more_time (int sig) 3318{ 3319 hire_a_guru(); 3320} 3321 3322 3323Coding Standards: 3324----------------- 3325 3326All contributions to U-Boot should conform to the Linux kernel 3327coding style; see the file "Documentation/CodingStyle" in your Linux 3328kernel source directory. 3329 3330Please note that U-Boot is implemented in C (and to some small parts 3331in Assembler); no C++ is used, so please do not use C++ style 3332comments (//) in your code. 3333 3334Please also stick to the following formatting rules: 3335- remove any trailing white space 3336- use TAB characters for indentation, not spaces 3337- make sure NOT to use DOS '\r\n' line feeds 3338- do not add more than 2 empty lines to source files 3339- do not add trailing empty lines to source files 3340 3341Submissions which do not conform to the standards may be returned 3342with a request to reformat the changes. 3343 3344 3345Submitting Patches: 3346------------------- 3347 3348Since the number of patches for U-Boot is growing, we need to 3349establish some rules. Submissions which do not conform to these rules 3350may be rejected, even when they contain important and valuable stuff. 3351 3352 3353When you send a patch, please include the following information with 3354it: 3355 3356* For bug fixes: a description of the bug and how your patch fixes 3357 this bug. Please try to include a way of demonstrating that the 3358 patch actually fixes something. 3359 3360* For new features: a description of the feature and your 3361 implementation. 3362 3363* A CHANGELOG entry as plaintext (separate from the patch) 3364 3365* For major contributions, your entry to the CREDITS file 3366 3367* When you add support for a new board, don't forget to add this 3368 board to the MAKEALL script, too. 3369 3370* If your patch adds new configuration options, don't forget to 3371 document these in the README file. 3372 3373* The patch itself. If you are accessing the CVS repository use "cvs 3374 update; cvs diff -puRN"; else, use "diff -purN OLD NEW". If your 3375 version of diff does not support these options, then get the latest 3376 version of GNU diff. 3377 3378 The current directory when running this command shall be the top 3379 level directory of the U-Boot source tree, or it's parent directory 3380 (i. e. please make sure that your patch includes sufficient 3381 directory information for the affected files). 3382 3383 We accept patches as plain text, MIME attachments or as uuencoded 3384 gzipped text. 3385 3386* If one logical set of modifications affects or creates several 3387 files, all these changes shall be submitted in a SINGLE patch file. 3388 3389* Changesets that contain different, unrelated modifications shall be 3390 submitted as SEPARATE patches, one patch per changeset. 3391 3392 3393Notes: 3394 3395* Before sending the patch, run the MAKEALL script on your patched 3396 source tree and make sure that no errors or warnings are reported 3397 for any of the boards. 3398 3399* Keep your modifications to the necessary minimum: A patch 3400 containing several unrelated changes or arbitrary reformats will be 3401 returned with a request to re-formatting / split it. 3402 3403* If you modify existing code, make sure that your new code does not 3404 add to the memory footprint of the code ;-) Small is beautiful! 3405 When adding new features, these should compile conditionally only 3406 (using #ifdef), and the resulting code with the new feature 3407 disabled must not need more memory than the old code without your 3408 modification. 3409