1# 2# (C) Copyright 2000 - 2004 3# Wolfgang Denk, DENX Software Engineering, wd@denx.de. 4# 5# See file CREDITS for list of people who contributed to this 6# project. 7# 8# This program is free software; you can redistribute it and/or 9# modify it under the terms of the GNU General Public License as 10# published by the Free Software Foundation; either version 2 of 11# the License, or (at your option) any later version. 12# 13# This program is distributed in the hope that it will be useful, 14# but WITHOUT ANY WARRANTY; without even the implied warranty of 15# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 16# GNU General Public License for more details. 17# 18# You should have received a copy of the GNU General Public License 19# along with this program; if not, write to the Free Software 20# Foundation, Inc., 59 Temple Place, Suite 330, Boston, 21# MA 02111-1307 USA 22# 23 24Summary: 25======== 26 27This directory contains the source code for U-Boot, a boot loader for 28Embedded boards based on PowerPC and ARM processors, which can be 29installed in a boot ROM and used to initialize and test the hardware 30or to download and run application code. 31 32The development of U-Boot is closely related to Linux: some parts of 33the source code originate in the Linux source tree, we have some 34header files in common, and special provision has been made to 35support booting of Linux images. 36 37Some attention has been paid to make this software easily 38configurable and extendable. For instance, all monitor commands are 39implemented with the same call interface, so that it's very easy to 40add new commands. Also, instead of permanently adding rarely used 41code (for instance hardware test utilities) to the monitor, you can 42load and run it dynamically. 43 44 45Status: 46======= 47 48In general, all boards for which a configuration option exists in the 49Makefile have been tested to some extent and can be considered 50"working". In fact, many of them are used in production systems. 51 52In case of problems see the CHANGELOG and CREDITS files to find out 53who contributed the specific port. 54 55 56Where to get help: 57================== 58 59In case you have questions about, problems with or contributions for 60U-Boot you should send a message to the U-Boot mailing list at 61<u-boot-users@lists.sourceforge.net>. There is also an archive of 62previous traffic on the mailing list - please search the archive 63before asking FAQ's. Please see 64http://lists.sourceforge.net/lists/listinfo/u-boot-users/ 65 66 67Where we come from: 68=================== 69 70- start from 8xxrom sources 71- create PPCBoot project (http://sourceforge.net/projects/ppcboot) 72- clean up code 73- make it easier to add custom boards 74- make it possible to add other [PowerPC] CPUs 75- extend functions, especially: 76 * Provide extended interface to Linux boot loader 77 * S-Record download 78 * network boot 79 * PCMCIA / CompactFLash / ATA disk / SCSI ... boot 80- create ARMBoot project (http://sourceforge.net/projects/armboot) 81- add other CPU families (starting with ARM) 82- create U-Boot project (http://sourceforge.net/projects/u-boot) 83 84 85Names and Spelling: 86=================== 87 88The "official" name of this project is "Das U-Boot". The spelling 89"U-Boot" shall be used in all written text (documentation, comments 90in source files etc.). Example: 91 92 This is the README file for the U-Boot project. 93 94File names etc. shall be based on the string "u-boot". Examples: 95 96 include/asm-ppc/u-boot.h 97 98 #include <asm/u-boot.h> 99 100Variable names, preprocessor constants etc. shall be either based on 101the string "u_boot" or on "U_BOOT". Example: 102 103 U_BOOT_VERSION u_boot_logo 104 IH_OS_U_BOOT u_boot_hush_start 105 106 107Versioning: 108=========== 109 110U-Boot uses a 3 level version number containing a version, a 111sub-version, and a patchlevel: "U-Boot-2.34.5" means version "2", 112sub-version "34", and patchlevel "4". 113 114The patchlevel is used to indicate certain stages of development 115between released versions, i. e. officially released versions of 116U-Boot will always have a patchlevel of "0". 117 118 119Directory Hierarchy: 120==================== 121 122- board Board dependent files 123- common Misc architecture independent functions 124- cpu CPU specific files 125 - 74xx_7xx Files specific to Motorola MPC74xx and 7xx CPUs 126 - arm720t Files specific to ARM 720 CPUs 127 - arm920t Files specific to ARM 920 CPUs 128 - imx Files specific to Motorola MC9328 i.MX CPUs 129 - s3c24x0 Files specific to Samsung S3C24X0 CPUs 130 - arm925t Files specific to ARM 925 CPUs 131 - arm926ejs Files specific to ARM 926 CPUs 132 - at91rm9200 Files specific to Atmel AT91RM9200 CPUs 133 - i386 Files specific to i386 CPUs 134 - ixp Files specific to Intel XScale IXP CPUs 135 - mcf52x2 Files specific to Motorola ColdFire MCF52x2 CPUs 136 - mips Files specific to MIPS CPUs 137 - mpc5xx Files specific to Motorola MPC5xx CPUs 138 - mpc5xxx Files specific to Motorola MPC5xxx CPUs 139 - mpc8xx Files specific to Motorola MPC8xx CPUs 140 - mpc824x Files specific to Motorola MPC824x CPUs 141 - mpc8260 Files specific to Motorola MPC8260 CPUs 142 - mpc85xx Files specific to Motorola MPC85xx CPUs 143 - nios Files specific to Altera NIOS CPUs 144 - nios2 Files specific to Altera Nios-II CPUs 145 - ppc4xx Files specific to IBM PowerPC 4xx CPUs 146 - pxa Files specific to Intel XScale PXA CPUs 147 - s3c44b0 Files specific to Samsung S3C44B0 CPUs 148 - sa1100 Files specific to Intel StrongARM SA1100 CPUs 149- disk Code for disk drive partition handling 150- doc Documentation (don't expect too much) 151- drivers Commonly used device drivers 152- dtt Digital Thermometer and Thermostat drivers 153- examples Example code for standalone applications, etc. 154- include Header Files 155- lib_arm Files generic to ARM architecture 156- lib_generic Files generic to all architectures 157- lib_i386 Files generic to i386 architecture 158- lib_m68k Files generic to m68k architecture 159- lib_mips Files generic to MIPS architecture 160- lib_nios Files generic to NIOS architecture 161- lib_ppc Files generic to PowerPC architecture 162- net Networking code 163- post Power On Self Test 164- rtc Real Time Clock drivers 165- tools Tools to build S-Record or U-Boot images, etc. 166 167Software Configuration: 168======================= 169 170Configuration is usually done using C preprocessor defines; the 171rationale behind that is to avoid dead code whenever possible. 172 173There are two classes of configuration variables: 174 175* Configuration _OPTIONS_: 176 These are selectable by the user and have names beginning with 177 "CONFIG_". 178 179* Configuration _SETTINGS_: 180 These depend on the hardware etc. and should not be meddled with if 181 you don't know what you're doing; they have names beginning with 182 "CFG_". 183 184Later we will add a configuration tool - probably similar to or even 185identical to what's used for the Linux kernel. Right now, we have to 186do the configuration by hand, which means creating some symbolic 187links and editing some configuration files. We use the TQM8xxL boards 188as an example here. 189 190 191Selection of Processor Architecture and Board Type: 192--------------------------------------------------- 193 194For all supported boards there are ready-to-use default 195configurations available; just type "make <board_name>_config". 196 197Example: For a TQM823L module type: 198 199 cd u-boot 200 make TQM823L_config 201 202For the Cogent platform, you need to specify the cpu type as well; 203e.g. "make cogent_mpc8xx_config". And also configure the cogent 204directory according to the instructions in cogent/README. 205 206 207Configuration Options: 208---------------------- 209 210Configuration depends on the combination of board and CPU type; all 211such information is kept in a configuration file 212"include/configs/<board_name>.h". 213 214Example: For a TQM823L module, all configuration settings are in 215"include/configs/TQM823L.h". 216 217 218Many of the options are named exactly as the corresponding Linux 219kernel configuration options. The intention is to make it easier to 220build a config tool - later. 221 222 223The following options need to be configured: 224 225- CPU Type: Define exactly one of 226 227 PowerPC based CPUs: 228 ------------------- 229 CONFIG_MPC823, CONFIG_MPC850, CONFIG_MPC855, CONFIG_MPC860 230 or CONFIG_MPC5xx 231 or CONFIG_MPC824X, CONFIG_MPC8260 232 or CONFIG_MPC85xx 233 or CONFIG_IOP480 234 or CONFIG_405GP 235 or CONFIG_405EP 236 or CONFIG_440 237 or CONFIG_MPC74xx 238 or CONFIG_750FX 239 240 ARM based CPUs: 241 --------------- 242 CONFIG_SA1110 243 CONFIG_ARM7 244 CONFIG_PXA250 245 246 MicroBlaze based CPUs: 247 ---------------------- 248 CONFIG_MICROBLAZE 249 250 Nios-2 based CPUs: 251 ---------------------- 252 CONFIG_NIOS2 253 254 255- Board Type: Define exactly one of 256 257 PowerPC based boards: 258 --------------------- 259 260 CONFIG_ADCIOP CONFIG_GEN860T CONFIG_PCI405 261 CONFIG_ADS860 CONFIG_GENIETV CONFIG_PCIPPC2 262 CONFIG_AMX860 CONFIG_GTH CONFIG_PCIPPC6 263 CONFIG_AR405 CONFIG_gw8260 CONFIG_pcu_e 264 CONFIG_BAB7xx CONFIG_hermes CONFIG_PIP405 265 CONFIG_c2mon CONFIG_hymod CONFIG_PM826 266 CONFIG_CANBT CONFIG_IAD210 CONFIG_ppmc8260 267 CONFIG_CCM CONFIG_ICU862 CONFIG_QS823 268 CONFIG_CMI CONFIG_IP860 CONFIG_QS850 269 CONFIG_cogent_mpc8260 CONFIG_IPHASE4539 CONFIG_QS860T 270 CONFIG_cogent_mpc8xx CONFIG_IVML24 CONFIG_RBC823 271 CONFIG_CPCI405 CONFIG_IVML24_128 CONFIG_RPXClassic 272 CONFIG_CPCI4052 CONFIG_IVML24_256 CONFIG_RPXlite 273 CONFIG_CPCIISER4 CONFIG_IVMS8 CONFIG_RPXsuper 274 CONFIG_CPU86 CONFIG_IVMS8_128 CONFIG_rsdproto 275 CONFIG_CRAYL1 CONFIG_IVMS8_256 CONFIG_sacsng 276 CONFIG_CSB272 CONFIG_JSE CONFIG_Sandpoint8240 277 CONFIG_CU824 CONFIG_LANTEC CONFIG_Sandpoint8245 278 CONFIG_DASA_SIM CONFIG_lwmon CONFIG_sbc8260 279 CONFIG_DB64360 CONFIG_MBX CONFIG_sbc8560 280 CONFIG_DB64460 CONFIG_MBX860T CONFIG_SM850 281 CONFIG_DU405 CONFIG_MHPC CONFIG_SPD823TS 282 CONFIG_DUET_ADS CONFIG_MIP405 CONFIG_STXGP3 283 CONFIG_EBONY CONFIG_MOUSSE CONFIG_SXNI855T 284 CONFIG_ELPPC CONFIG_MPC8260ADS CONFIG_TQM823L 285 CONFIG_ELPT860 CONFIG_MPC8540ADS CONFIG_TQM8260 286 CONFIG_ep8260 CONFIG_MPC8560ADS CONFIG_TQM850L 287 CONFIG_ERIC CONFIG_MUSENKI CONFIG_TQM855L 288 CONFIG_ESTEEM192E CONFIG_MVS1 CONFIG_TQM860L 289 CONFIG_ETX094 CONFIG_NETPHONE CONFIG_TTTech 290 CONFIG_EVB64260 CONFIG_NETTA CONFIG_UTX8245 291 CONFIG_FADS823 CONFIG_NETVIA CONFIG_V37 292 CONFIG_FADS850SAR CONFIG_NX823 CONFIG_W7OLMC 293 CONFIG_FADS860T CONFIG_OCRTC CONFIG_W7OLMG 294 CONFIG_FLAGADM CONFIG_ORSG CONFIG_WALNUT405 295 CONFIG_FPS850L CONFIG_OXC CONFIG_ZPC1900 296 CONFIG_FPS860L CONFIG_ZUMA 297 298 ARM based boards: 299 ----------------- 300 301 CONFIG_AT91RM9200DK, CONFIG_CERF250, CONFIG_DNP1110, 302 CONFIG_EP7312, CONFIG_H2_OMAP1610, CONFIG_HHP_CRADLE, 303 CONFIG_IMPA7, CONFIG_INNOVATOROMAP1510, CONFIG_INNOVATOROMAP1610, 304 CONFIG_LART, CONFIG_LPD7A400 CONFIG_LUBBOCK, 305 CONFIG_OSK_OMAP5912, CONFIG_SHANNON, CONFIG_P2_OMAP730, 306 CONFIG_SMDK2400, CONFIG_SMDK2410, CONFIG_TRAB, 307 CONFIG_VCMA9 308 309 MicroBlaze based boards: 310 ------------------------ 311 312 CONFIG_SUZAKU 313 314 Nios-2 based boards: 315 ------------------------ 316 317 CONFIG_PCI5441 CONFIG_PK1C20 318 319 320- CPU Module Type: (if CONFIG_COGENT is defined) 321 Define exactly one of 322 CONFIG_CMA286_60_OLD 323--- FIXME --- not tested yet: 324 CONFIG_CMA286_60, CONFIG_CMA286_21, CONFIG_CMA286_60P, 325 CONFIG_CMA287_23, CONFIG_CMA287_50 326 327- Motherboard Type: (if CONFIG_COGENT is defined) 328 Define exactly one of 329 CONFIG_CMA101, CONFIG_CMA102 330 331- Motherboard I/O Modules: (if CONFIG_COGENT is defined) 332 Define one or more of 333 CONFIG_CMA302 334 335- Motherboard Options: (if CONFIG_CMA101 or CONFIG_CMA102 are defined) 336 Define one or more of 337 CONFIG_LCD_HEARTBEAT - update a character position on 338 the lcd display every second with 339 a "rotator" |\-/|\-/ 340 341- Board flavour: (if CONFIG_MPC8260ADS is defined) 342 CONFIG_ADSTYPE 343 Possible values are: 344 CFG_8260ADS - original MPC8260ADS 345 CFG_8266ADS - MPC8266ADS 346 CFG_PQ2FADS - PQ2FADS-ZU or PQ2FADS-VR 347 CFG_8272ADS - MPC8272ADS 348 349- MPC824X Family Member (if CONFIG_MPC824X is defined) 350 Define exactly one of 351 CONFIG_MPC8240, CONFIG_MPC8245 352 353- 8xx CPU Options: (if using an MPC8xx cpu) 354 CONFIG_8xx_GCLK_FREQ - deprecated: CPU clock if 355 get_gclk_freq() cannot work 356 e.g. if there is no 32KHz 357 reference PIT/RTC clock 358 CONFIG_8xx_OSCLK - PLL input clock (either EXTCLK 359 or XTAL/EXTAL) 360 361- 859/866/885 CPU options: (if using a MPC859 or MPC866 or MPC885 CPU): 362 CFG_8xx_CPUCLK_MIN 363 CFG_8xx_CPUCLK_MAX 364 CONFIG_8xx_CPUCLK_DEFAULT 365 See doc/README.MPC866 366 367 CFG_MEASURE_CPUCLK 368 369 Define this to measure the actual CPU clock instead 370 of relying on the correctness of the configured 371 values. Mostly useful for board bringup to make sure 372 the PLL is locked at the intended frequency. Note 373 that this requires a (stable) reference clock (32 kHz 374 RTC clock or CFG_8XX_XIN) 375 376- Linux Kernel Interface: 377 CONFIG_CLOCKS_IN_MHZ 378 379 U-Boot stores all clock information in Hz 380 internally. For binary compatibility with older Linux 381 kernels (which expect the clocks passed in the 382 bd_info data to be in MHz) the environment variable 383 "clocks_in_mhz" can be defined so that U-Boot 384 converts clock data to MHZ before passing it to the 385 Linux kernel. 386 When CONFIG_CLOCKS_IN_MHZ is defined, a definition of 387 "clocks_in_mhz=1" is automatically included in the 388 default environment. 389 390 CONFIG_MEMSIZE_IN_BYTES [relevant for MIPS only] 391 392 When transfering memsize parameter to linux, some versions 393 expect it to be in bytes, others in MB. 394 Define CONFIG_MEMSIZE_IN_BYTES to make it in bytes. 395 396- Serial Ports: 397 CFG_PL010_SERIAL 398 399 Define this if you want support for Amba PrimeCell PL010 UARTs. 400 401 CFG_PL011_SERIAL 402 403 Define this if you want support for Amba PrimeCell PL011 UARTs. 404 405 CONFIG_PL011_CLOCK 406 407 If you have Amba PrimeCell PL011 UARTs, set this variable to 408 the clock speed of the UARTs. 409 410 CONFIG_PL01x_PORTS 411 412 If you have Amba PrimeCell PL010 or PL011 UARTs on your board, 413 define this to a list of base addresses for each (supported) 414 port. See e.g. include/configs/versatile.h 415 416 417- Console Interface: 418 Depending on board, define exactly one serial port 419 (like CONFIG_8xx_CONS_SMC1, CONFIG_8xx_CONS_SMC2, 420 CONFIG_8xx_CONS_SCC1, ...), or switch off the serial 421 console by defining CONFIG_8xx_CONS_NONE 422 423 Note: if CONFIG_8xx_CONS_NONE is defined, the serial 424 port routines must be defined elsewhere 425 (i.e. serial_init(), serial_getc(), ...) 426 427 CONFIG_CFB_CONSOLE 428 Enables console device for a color framebuffer. Needs following 429 defines (cf. smiLynxEM, i8042, board/eltec/bab7xx) 430 VIDEO_FB_LITTLE_ENDIAN graphic memory organisation 431 (default big endian) 432 VIDEO_HW_RECTFILL graphic chip supports 433 rectangle fill 434 (cf. smiLynxEM) 435 VIDEO_HW_BITBLT graphic chip supports 436 bit-blit (cf. smiLynxEM) 437 VIDEO_VISIBLE_COLS visible pixel columns 438 (cols=pitch) 439 VIDEO_VISIBLE_ROWS visible pixel rows 440 VIDEO_PIXEL_SIZE bytes per pixel 441 VIDEO_DATA_FORMAT graphic data format 442 (0-5, cf. cfb_console.c) 443 VIDEO_FB_ADRS framebuffer address 444 VIDEO_KBD_INIT_FCT keyboard int fct 445 (i.e. i8042_kbd_init()) 446 VIDEO_TSTC_FCT test char fct 447 (i.e. i8042_tstc) 448 VIDEO_GETC_FCT get char fct 449 (i.e. i8042_getc) 450 CONFIG_CONSOLE_CURSOR cursor drawing on/off 451 (requires blink timer 452 cf. i8042.c) 453 CFG_CONSOLE_BLINK_COUNT blink interval (cf. i8042.c) 454 CONFIG_CONSOLE_TIME display time/date info in 455 upper right corner 456 (requires CFG_CMD_DATE) 457 CONFIG_VIDEO_LOGO display Linux logo in 458 upper left corner 459 CONFIG_VIDEO_BMP_LOGO use bmp_logo.h instead of 460 linux_logo.h for logo. 461 Requires CONFIG_VIDEO_LOGO 462 CONFIG_CONSOLE_EXTRA_INFO 463 addional board info beside 464 the logo 465 466 When CONFIG_CFB_CONSOLE is defined, video console is 467 default i/o. Serial console can be forced with 468 environment 'console=serial'. 469 470 When CONFIG_SILENT_CONSOLE is defined, all console 471 messages (by U-Boot and Linux!) can be silenced with 472 the "silent" environment variable. See 473 doc/README.silent for more information. 474 475- Console Baudrate: 476 CONFIG_BAUDRATE - in bps 477 Select one of the baudrates listed in 478 CFG_BAUDRATE_TABLE, see below. 479 CFG_BRGCLK_PRESCALE, baudrate prescale 480 481- Interrupt driven serial port input: 482 CONFIG_SERIAL_SOFTWARE_FIFO 483 484 PPC405GP only. 485 Use an interrupt handler for receiving data on the 486 serial port. It also enables using hardware handshake 487 (RTS/CTS) and UART's built-in FIFO. Set the number of 488 bytes the interrupt driven input buffer should have. 489 490 Leave undefined to disable this feature, including 491 disable the buffer and hardware handshake. 492 493- Console UART Number: 494 CONFIG_UART1_CONSOLE 495 496 IBM PPC4xx only. 497 If defined internal UART1 (and not UART0) is used 498 as default U-Boot console. 499 500- Boot Delay: CONFIG_BOOTDELAY - in seconds 501 Delay before automatically booting the default image; 502 set to -1 to disable autoboot. 503 504 See doc/README.autoboot for these options that 505 work with CONFIG_BOOTDELAY. None are required. 506 CONFIG_BOOT_RETRY_TIME 507 CONFIG_BOOT_RETRY_MIN 508 CONFIG_AUTOBOOT_KEYED 509 CONFIG_AUTOBOOT_PROMPT 510 CONFIG_AUTOBOOT_DELAY_STR 511 CONFIG_AUTOBOOT_STOP_STR 512 CONFIG_AUTOBOOT_DELAY_STR2 513 CONFIG_AUTOBOOT_STOP_STR2 514 CONFIG_ZERO_BOOTDELAY_CHECK 515 CONFIG_RESET_TO_RETRY 516 517- Autoboot Command: 518 CONFIG_BOOTCOMMAND 519 Only needed when CONFIG_BOOTDELAY is enabled; 520 define a command string that is automatically executed 521 when no character is read on the console interface 522 within "Boot Delay" after reset. 523 524 CONFIG_BOOTARGS 525 This can be used to pass arguments to the bootm 526 command. The value of CONFIG_BOOTARGS goes into the 527 environment value "bootargs". 528 529 CONFIG_RAMBOOT and CONFIG_NFSBOOT 530 The value of these goes into the environment as 531 "ramboot" and "nfsboot" respectively, and can be used 532 as a convenience, when switching between booting from 533 ram and nfs. 534 535- Pre-Boot Commands: 536 CONFIG_PREBOOT 537 538 When this option is #defined, the existence of the 539 environment variable "preboot" will be checked 540 immediately before starting the CONFIG_BOOTDELAY 541 countdown and/or running the auto-boot command resp. 542 entering interactive mode. 543 544 This feature is especially useful when "preboot" is 545 automatically generated or modified. For an example 546 see the LWMON board specific code: here "preboot" is 547 modified when the user holds down a certain 548 combination of keys on the (special) keyboard when 549 booting the systems 550 551- Serial Download Echo Mode: 552 CONFIG_LOADS_ECHO 553 If defined to 1, all characters received during a 554 serial download (using the "loads" command) are 555 echoed back. This might be needed by some terminal 556 emulations (like "cu"), but may as well just take 557 time on others. This setting #define's the initial 558 value of the "loads_echo" environment variable. 559 560- Kgdb Serial Baudrate: (if CFG_CMD_KGDB is defined) 561 CONFIG_KGDB_BAUDRATE 562 Select one of the baudrates listed in 563 CFG_BAUDRATE_TABLE, see below. 564 565- Monitor Functions: 566 CONFIG_COMMANDS 567 Most monitor functions can be selected (or 568 de-selected) by adjusting the definition of 569 CONFIG_COMMANDS; to select individual functions, 570 #define CONFIG_COMMANDS by "OR"ing any of the 571 following values: 572 573 #define enables commands: 574 ------------------------- 575 CFG_CMD_ASKENV * ask for env variable 576 CFG_CMD_AUTOSCRIPT Autoscript Support 577 CFG_CMD_BDI bdinfo 578 CFG_CMD_BEDBUG * Include BedBug Debugger 579 CFG_CMD_BMP * BMP support 580 CFG_CMD_BSP * Board specific commands 581 CFG_CMD_BOOTD bootd 582 CFG_CMD_CACHE * icache, dcache 583 CFG_CMD_CONSOLE coninfo 584 CFG_CMD_DATE * support for RTC, date/time... 585 CFG_CMD_DHCP * DHCP support 586 CFG_CMD_DIAG * Diagnostics 587 CFG_CMD_DOC * Disk-On-Chip Support 588 CFG_CMD_DTT * Digital Therm and Thermostat 589 CFG_CMD_ECHO * echo arguments 590 CFG_CMD_EEPROM * EEPROM read/write support 591 CFG_CMD_ELF * bootelf, bootvx 592 CFG_CMD_ENV saveenv 593 CFG_CMD_FDC * Floppy Disk Support 594 CFG_CMD_FAT * FAT partition support 595 CFG_CMD_FDOS * Dos diskette Support 596 CFG_CMD_FLASH flinfo, erase, protect 597 CFG_CMD_FPGA FPGA device initialization support 598 CFG_CMD_HWFLOW * RTS/CTS hw flow control 599 CFG_CMD_I2C * I2C serial bus support 600 CFG_CMD_IDE * IDE harddisk support 601 CFG_CMD_IMI iminfo 602 CFG_CMD_IMLS List all found images 603 CFG_CMD_IMMAP * IMMR dump support 604 CFG_CMD_IRQ * irqinfo 605 CFG_CMD_ITEST Integer/string test of 2 values 606 CFG_CMD_JFFS2 * JFFS2 Support 607 CFG_CMD_KGDB * kgdb 608 CFG_CMD_LOADB loadb 609 CFG_CMD_LOADS loads 610 CFG_CMD_MEMORY md, mm, nm, mw, cp, cmp, crc, base, 611 loop, loopw, mtest 612 CFG_CMD_MISC Misc functions like sleep etc 613 CFG_CMD_MMC * MMC memory mapped support 614 CFG_CMD_MII * MII utility commands 615 CFG_CMD_NAND * NAND support 616 CFG_CMD_NET bootp, tftpboot, rarpboot 617 CFG_CMD_PCI * pciinfo 618 CFG_CMD_PCMCIA * PCMCIA support 619 CFG_CMD_PING * send ICMP ECHO_REQUEST to network host 620 CFG_CMD_PORTIO * Port I/O 621 CFG_CMD_REGINFO * Register dump 622 CFG_CMD_RUN run command in env variable 623 CFG_CMD_SAVES * save S record dump 624 CFG_CMD_SCSI * SCSI Support 625 CFG_CMD_SDRAM * print SDRAM configuration information 626 CFG_CMD_SETGETDCR Support for DCR Register access (4xx only) 627 CFG_CMD_SPI * SPI serial bus support 628 CFG_CMD_USB * USB support 629 CFG_CMD_VFD * VFD support (TRAB) 630 CFG_CMD_BSP * Board SPecific functions 631 CFG_CMD_CDP * Cisco Discover Protocol support 632 ----------------------------------------------- 633 CFG_CMD_ALL all 634 635 CONFIG_CMD_DFL Default configuration; at the moment 636 this is includes all commands, except 637 the ones marked with "*" in the list 638 above. 639 640 If you don't define CONFIG_COMMANDS it defaults to 641 CONFIG_CMD_DFL in include/cmd_confdefs.h. A board can 642 override the default settings in the respective 643 include file. 644 645 EXAMPLE: If you want all functions except of network 646 support you can write: 647 648 #define CONFIG_COMMANDS (CFG_CMD_ALL & ~CFG_CMD_NET) 649 650 651 Note: Don't enable the "icache" and "dcache" commands 652 (configuration option CFG_CMD_CACHE) unless you know 653 what you (and your U-Boot users) are doing. Data 654 cache cannot be enabled on systems like the 8xx or 655 8260 (where accesses to the IMMR region must be 656 uncached), and it cannot be disabled on all other 657 systems where we (mis-) use the data cache to hold an 658 initial stack and some data. 659 660 661 XXX - this list needs to get updated! 662 663- Watchdog: 664 CONFIG_WATCHDOG 665 If this variable is defined, it enables watchdog 666 support. There must be support in the platform specific 667 code for a watchdog. For the 8xx and 8260 CPUs, the 668 SIU Watchdog feature is enabled in the SYPCR 669 register. 670 671- U-Boot Version: 672 CONFIG_VERSION_VARIABLE 673 If this variable is defined, an environment variable 674 named "ver" is created by U-Boot showing the U-Boot 675 version as printed by the "version" command. 676 This variable is readonly. 677 678- Real-Time Clock: 679 680 When CFG_CMD_DATE is selected, the type of the RTC 681 has to be selected, too. Define exactly one of the 682 following options: 683 684 CONFIG_RTC_MPC8xx - use internal RTC of MPC8xx 685 CONFIG_RTC_PCF8563 - use Philips PCF8563 RTC 686 CONFIG_RTC_MC146818 - use MC146818 RTC 687 CONFIG_RTC_DS1307 - use Maxim, Inc. DS1307 RTC 688 CONFIG_RTC_DS1337 - use Maxim, Inc. DS1337 RTC 689 CONFIG_RTC_DS1338 - use Maxim, Inc. DS1338 RTC 690 CONFIG_RTC_DS164x - use Dallas DS164x RTC 691 CONFIG_RTC_MAX6900 - use Maxim, Inc. MAX6900 RTC 692 693 Note that if the RTC uses I2C, then the I2C interface 694 must also be configured. See I2C Support, below. 695 696- Timestamp Support: 697 698 When CONFIG_TIMESTAMP is selected, the timestamp 699 (date and time) of an image is printed by image 700 commands like bootm or iminfo. This option is 701 automatically enabled when you select CFG_CMD_DATE . 702 703- Partition Support: 704 CONFIG_MAC_PARTITION and/or CONFIG_DOS_PARTITION 705 and/or CONFIG_ISO_PARTITION 706 707 If IDE or SCSI support is enabled (CFG_CMD_IDE or 708 CFG_CMD_SCSI) you must configure support for at least 709 one partition type as well. 710 711- IDE Reset method: 712 CONFIG_IDE_RESET_ROUTINE - this is defined in several 713 board configurations files but used nowhere! 714 715 CONFIG_IDE_RESET - is this is defined, IDE Reset will 716 be performed by calling the function 717 ide_set_reset(int reset) 718 which has to be defined in a board specific file 719 720- ATAPI Support: 721 CONFIG_ATAPI 722 723 Set this to enable ATAPI support. 724 725- LBA48 Support 726 CONFIG_LBA48 727 728 Set this to enable support for disks larger than 137GB 729 Also look at CFG_64BIT_LBA ,CFG_64BIT_VSPRINTF and CFG_64BIT_STRTOUL 730 Whithout these , LBA48 support uses 32bit variables and will 'only' 731 support disks up to 2.1TB. 732 733 CFG_64BIT_LBA: 734 When enabled, makes the IDE subsystem use 64bit sector addresses. 735 Default is 32bit. 736 737- SCSI Support: 738 At the moment only there is only support for the 739 SYM53C8XX SCSI controller; define 740 CONFIG_SCSI_SYM53C8XX to enable it. 741 742 CFG_SCSI_MAX_LUN [8], CFG_SCSI_MAX_SCSI_ID [7] and 743 CFG_SCSI_MAX_DEVICE [CFG_SCSI_MAX_SCSI_ID * 744 CFG_SCSI_MAX_LUN] can be adjusted to define the 745 maximum numbers of LUNs, SCSI ID's and target 746 devices. 747 CFG_SCSI_SYM53C8XX_CCF to fix clock timing (80Mhz) 748 749- NETWORK Support (PCI): 750 CONFIG_E1000 751 Support for Intel 8254x gigabit chips. 752 753 CONFIG_EEPRO100 754 Support for Intel 82557/82559/82559ER chips. 755 Optional CONFIG_EEPRO100_SROM_WRITE enables eeprom 756 write routine for first time initialisation. 757 758 CONFIG_TULIP 759 Support for Digital 2114x chips. 760 Optional CONFIG_TULIP_SELECT_MEDIA for board specific 761 modem chip initialisation (KS8761/QS6611). 762 763 CONFIG_NATSEMI 764 Support for National dp83815 chips. 765 766 CONFIG_NS8382X 767 Support for National dp8382[01] gigabit chips. 768 769- NETWORK Support (other): 770 771 CONFIG_DRIVER_LAN91C96 772 Support for SMSC's LAN91C96 chips. 773 774 CONFIG_LAN91C96_BASE 775 Define this to hold the physical address 776 of the LAN91C96's I/O space 777 778 CONFIG_LAN91C96_USE_32_BIT 779 Define this to enable 32 bit addressing 780 781 CONFIG_DRIVER_SMC91111 782 Support for SMSC's LAN91C111 chip 783 784 CONFIG_SMC91111_BASE 785 Define this to hold the physical address 786 of the device (I/O space) 787 788 CONFIG_SMC_USE_32_BIT 789 Define this if data bus is 32 bits 790 791 CONFIG_SMC_USE_IOFUNCS 792 Define this to use i/o functions instead of macros 793 (some hardware wont work with macros) 794 795- USB Support: 796 At the moment only the UHCI host controller is 797 supported (PIP405, MIP405, MPC5200); define 798 CONFIG_USB_UHCI to enable it. 799 define CONFIG_USB_KEYBOARD to enable the USB Keyboard 800 and define CONFIG_USB_STORAGE to enable the USB 801 storage devices. 802 Note: 803 Supported are USB Keyboards and USB Floppy drives 804 (TEAC FD-05PUB). 805 MPC5200 USB requires additional defines: 806 CONFIG_USB_CLOCK 807 for 528 MHz Clock: 0x0001bbbb 808 CONFIG_USB_CONFIG 809 for differential drivers: 0x00001000 810 for single ended drivers: 0x00005000 811 812 813- MMC Support: 814 The MMC controller on the Intel PXA is supported. To 815 enable this define CONFIG_MMC. The MMC can be 816 accessed from the boot prompt by mapping the device 817 to physical memory similar to flash. Command line is 818 enabled with CFG_CMD_MMC. The MMC driver also works with 819 the FAT fs. This is enabled with CFG_CMD_FAT. 820 821- Journaling Flash filesystem support: 822 CONFIG_JFFS2_NAND, CONFIG_JFFS2_NAND_OFF, CONFIG_JFFS2_NAND_SIZE, 823 CONFIG_JFFS2_NAND_DEV 824 Define these for a default partition on a NAND device 825 826 CFG_JFFS2_FIRST_SECTOR, 827 CFG_JFFS2_FIRST_BANK, CFG_JFFS2_NUM_BANKS 828 Define these for a default partition on a NOR device 829 830 CFG_JFFS_CUSTOM_PART 831 Define this to create an own partition. You have to provide a 832 function struct part_info* jffs2_part_info(int part_num) 833 834 If you define only one JFFS2 partition you may also want to 835 #define CFG_JFFS_SINGLE_PART 1 836 to disable the command chpart. This is the default when you 837 have not defined a custom partition 838 839- Keyboard Support: 840 CONFIG_ISA_KEYBOARD 841 842 Define this to enable standard (PC-Style) keyboard 843 support 844 845 CONFIG_I8042_KBD 846 Standard PC keyboard driver with US (is default) and 847 GERMAN key layout (switch via environment 'keymap=de') support. 848 Export function i8042_kbd_init, i8042_tstc and i8042_getc 849 for cfb_console. Supports cursor blinking. 850 851- Video support: 852 CONFIG_VIDEO 853 854 Define this to enable video support (for output to 855 video). 856 857 CONFIG_VIDEO_CT69000 858 859 Enable Chips & Technologies 69000 Video chip 860 861 CONFIG_VIDEO_SMI_LYNXEM 862 Enable Silicon Motion SMI 712/710/810 Video chip. The 863 video output is selected via environment 'videoout' 864 (1 = LCD and 2 = CRT). If videoout is undefined, CRT is 865 assumed. 866 867 For the CT69000 and SMI_LYNXEM drivers, videomode is 868 selected via environment 'videomode'. Two diferent ways 869 are possible: 870 - "videomode=num" 'num' is a standard LiLo mode numbers. 871 Following standard modes are supported (* is default): 872 873 Colors 640x480 800x600 1024x768 1152x864 1280x1024 874 -------------+--------------------------------------------- 875 8 bits | 0x301* 0x303 0x305 0x161 0x307 876 15 bits | 0x310 0x313 0x316 0x162 0x319 877 16 bits | 0x311 0x314 0x317 0x163 0x31A 878 24 bits | 0x312 0x315 0x318 ? 0x31B 879 -------------+--------------------------------------------- 880 (i.e. setenv videomode 317; saveenv; reset;) 881 882 - "videomode=bootargs" all the video parameters are parsed 883 from the bootargs. (See drivers/videomodes.c) 884 885 886 CONFIG_VIDEO_SED13806 887 Enable Epson SED13806 driver. This driver supports 8bpp 888 and 16bpp modes defined by CONFIG_VIDEO_SED13806_8BPP 889 or CONFIG_VIDEO_SED13806_16BPP 890 891- Keyboard Support: 892 CONFIG_KEYBOARD 893 894 Define this to enable a custom keyboard support. 895 This simply calls drv_keyboard_init() which must be 896 defined in your board-specific files. 897 The only board using this so far is RBC823. 898 899- LCD Support: CONFIG_LCD 900 901 Define this to enable LCD support (for output to LCD 902 display); also select one of the supported displays 903 by defining one of these: 904 905 CONFIG_NEC_NL6448AC33: 906 907 NEC NL6448AC33-18. Active, color, single scan. 908 909 CONFIG_NEC_NL6448BC20 910 911 NEC NL6448BC20-08. 6.5", 640x480. 912 Active, color, single scan. 913 914 CONFIG_NEC_NL6448BC33_54 915 916 NEC NL6448BC33-54. 10.4", 640x480. 917 Active, color, single scan. 918 919 CONFIG_SHARP_16x9 920 921 Sharp 320x240. Active, color, single scan. 922 It isn't 16x9, and I am not sure what it is. 923 924 CONFIG_SHARP_LQ64D341 925 926 Sharp LQ64D341 display, 640x480. 927 Active, color, single scan. 928 929 CONFIG_HLD1045 930 931 HLD1045 display, 640x480. 932 Active, color, single scan. 933 934 CONFIG_OPTREX_BW 935 936 Optrex CBL50840-2 NF-FW 99 22 M5 937 or 938 Hitachi LMG6912RPFC-00T 939 or 940 Hitachi SP14Q002 941 942 320x240. Black & white. 943 944 Normally display is black on white background; define 945 CFG_WHITE_ON_BLACK to get it inverted. 946 947- Splash Screen Support: CONFIG_SPLASH_SCREEN 948 949 If this option is set, the environment is checked for 950 a variable "splashimage". If found, the usual display 951 of logo, copyright and system information on the LCD 952 is suppressed and the BMP image at the address 953 specified in "splashimage" is loaded instead. The 954 console is redirected to the "nulldev", too. This 955 allows for a "silent" boot where a splash screen is 956 loaded very quickly after power-on. 957 958- Compression support: 959 CONFIG_BZIP2 960 961 If this option is set, support for bzip2 compressed 962 images is included. If not, only uncompressed and gzip 963 compressed images are supported. 964 965 NOTE: the bzip2 algorithm requires a lot of RAM, so 966 the malloc area (as defined by CFG_MALLOC_LEN) should 967 be at least 4MB. 968 969- MII/PHY support: 970 CONFIG_PHY_ADDR 971 972 The address of PHY on MII bus. 973 974 CONFIG_PHY_CLOCK_FREQ (ppc4xx) 975 976 The clock frequency of the MII bus 977 978 CONFIG_PHY_GIGE 979 980 If this option is set, support for speed/duplex 981 detection of Gigabit PHY is included. 982 983 CONFIG_PHY_RESET_DELAY 984 985 Some PHY like Intel LXT971A need extra delay after 986 reset before any MII register access is possible. 987 For such PHY, set this option to the usec delay 988 required. (minimum 300usec for LXT971A) 989 990 CONFIG_PHY_CMD_DELAY (ppc4xx) 991 992 Some PHY like Intel LXT971A need extra delay after 993 command issued before MII status register can be read 994 995- Ethernet address: 996 CONFIG_ETHADDR 997 CONFIG_ETH2ADDR 998 CONFIG_ETH3ADDR 999 1000 Define a default value for ethernet address to use 1001 for the respective ethernet interface, in case this 1002 is not determined automatically. 1003 1004- IP address: 1005 CONFIG_IPADDR 1006 1007 Define a default value for the IP address to use for 1008 the default ethernet interface, in case this is not 1009 determined through e.g. bootp. 1010 1011- Server IP address: 1012 CONFIG_SERVERIP 1013 1014 Defines a default value for theIP address of a TFTP 1015 server to contact when using the "tftboot" command. 1016 1017- BOOTP Recovery Mode: 1018 CONFIG_BOOTP_RANDOM_DELAY 1019 1020 If you have many targets in a network that try to 1021 boot using BOOTP, you may want to avoid that all 1022 systems send out BOOTP requests at precisely the same 1023 moment (which would happen for instance at recovery 1024 from a power failure, when all systems will try to 1025 boot, thus flooding the BOOTP server. Defining 1026 CONFIG_BOOTP_RANDOM_DELAY causes a random delay to be 1027 inserted before sending out BOOTP requests. The 1028 following delays are insterted then: 1029 1030 1st BOOTP request: delay 0 ... 1 sec 1031 2nd BOOTP request: delay 0 ... 2 sec 1032 3rd BOOTP request: delay 0 ... 4 sec 1033 4th and following 1034 BOOTP requests: delay 0 ... 8 sec 1035 1036- DHCP Advanced Options: 1037 CONFIG_BOOTP_MASK 1038 1039 You can fine tune the DHCP functionality by adding 1040 these flags to the CONFIG_BOOTP_MASK define: 1041 1042 CONFIG_BOOTP_DNS2 - If a DHCP client requests the DNS 1043 serverip from a DHCP server, it is possible that more 1044 than one DNS serverip is offered to the client. 1045 If CONFIG_BOOTP_DNS2 is enabled, the secondary DNS 1046 serverip will be stored in the additional environment 1047 variable "dnsip2". The first DNS serverip is always 1048 stored in the variable "dnsip", when CONFIG_BOOTP_DNS 1049 is added to the CONFIG_BOOTP_MASK. 1050 1051 CONFIG_BOOTP_SEND_HOSTNAME - Some DHCP servers are capable 1052 to do a dynamic update of a DNS server. To do this, they 1053 need the hostname of the DHCP requester. 1054 If CONFIG_BOOP_SEND_HOSTNAME is added to the 1055 CONFIG_BOOTP_MASK, the content of the "hostname" 1056 environment variable is passed as option 12 to 1057 the DHCP server. 1058 1059 - CDP Options: 1060 CONFIG_CDP_DEVICE_ID 1061 1062 The device id used in CDP trigger frames. 1063 1064 CONFIG_CDP_DEVICE_ID_PREFIX 1065 1066 A two character string which is prefixed to the MAC address 1067 of the device. 1068 1069 CONFIG_CDP_PORT_ID 1070 1071 A printf format string which contains the ascii name of 1072 the port. Normally is set to "eth%d" which sets 1073 eth0 for the first ethernet, eth1 for the second etc. 1074 1075 CONFIG_CDP_CAPABILITIES 1076 1077 A 32bit integer which indicates the device capabilities; 1078 0x00000010 for a normal host which does not forwards. 1079 1080 CONFIG_CDP_VERSION 1081 1082 An ascii string containing the version of the software. 1083 1084 CONFIG_CDP_PLATFORM 1085 1086 An ascii string containing the name of the platform. 1087 1088 CONFIG_CDP_TRIGGER 1089 1090 A 32bit integer sent on the trigger. 1091 1092 CONFIG_CDP_POWER_CONSUMPTION 1093 1094 A 16bit integer containing the power consumption of the 1095 device in .1 of milliwatts. 1096 1097 CONFIG_CDP_APPLIANCE_VLAN_TYPE 1098 1099 A byte containing the id of the VLAN. 1100 1101- Status LED: CONFIG_STATUS_LED 1102 1103 Several configurations allow to display the current 1104 status using a LED. For instance, the LED will blink 1105 fast while running U-Boot code, stop blinking as 1106 soon as a reply to a BOOTP request was received, and 1107 start blinking slow once the Linux kernel is running 1108 (supported by a status LED driver in the Linux 1109 kernel). Defining CONFIG_STATUS_LED enables this 1110 feature in U-Boot. 1111 1112- CAN Support: CONFIG_CAN_DRIVER 1113 1114 Defining CONFIG_CAN_DRIVER enables CAN driver support 1115 on those systems that support this (optional) 1116 feature, like the TQM8xxL modules. 1117 1118- I2C Support: CONFIG_HARD_I2C | CONFIG_SOFT_I2C 1119 1120 These enable I2C serial bus commands. Defining either of 1121 (but not both of) CONFIG_HARD_I2C or CONFIG_SOFT_I2C will 1122 include the appropriate I2C driver for the selected cpu. 1123 1124 This will allow you to use i2c commands at the u-boot 1125 command line (as long as you set CFG_CMD_I2C in 1126 CONFIG_COMMANDS) and communicate with i2c based realtime 1127 clock chips. See common/cmd_i2c.c for a description of the 1128 command line interface. 1129 1130 CONFIG_HARD_I2C selects the CPM hardware driver for I2C. 1131 1132 CONFIG_SOFT_I2C configures u-boot to use a software (aka 1133 bit-banging) driver instead of CPM or similar hardware 1134 support for I2C. 1135 1136 There are several other quantities that must also be 1137 defined when you define CONFIG_HARD_I2C or CONFIG_SOFT_I2C. 1138 1139 In both cases you will need to define CFG_I2C_SPEED 1140 to be the frequency (in Hz) at which you wish your i2c bus 1141 to run and CFG_I2C_SLAVE to be the address of this node (ie 1142 the cpu's i2c node address). 1143 1144 Now, the u-boot i2c code for the mpc8xx (cpu/mpc8xx/i2c.c) 1145 sets the cpu up as a master node and so its address should 1146 therefore be cleared to 0 (See, eg, MPC823e User's Manual 1147 p.16-473). So, set CFG_I2C_SLAVE to 0. 1148 1149 That's all that's required for CONFIG_HARD_I2C. 1150 1151 If you use the software i2c interface (CONFIG_SOFT_I2C) 1152 then the following macros need to be defined (examples are 1153 from include/configs/lwmon.h): 1154 1155 I2C_INIT 1156 1157 (Optional). Any commands necessary to enable the I2C 1158 controller or configure ports. 1159 1160 eg: #define I2C_INIT (immr->im_cpm.cp_pbdir |= PB_SCL) 1161 1162 I2C_PORT 1163 1164 (Only for MPC8260 CPU). The I/O port to use (the code 1165 assumes both bits are on the same port). Valid values 1166 are 0..3 for ports A..D. 1167 1168 I2C_ACTIVE 1169 1170 The code necessary to make the I2C data line active 1171 (driven). If the data line is open collector, this 1172 define can be null. 1173 1174 eg: #define I2C_ACTIVE (immr->im_cpm.cp_pbdir |= PB_SDA) 1175 1176 I2C_TRISTATE 1177 1178 The code necessary to make the I2C data line tri-stated 1179 (inactive). If the data line is open collector, this 1180 define can be null. 1181 1182 eg: #define I2C_TRISTATE (immr->im_cpm.cp_pbdir &= ~PB_SDA) 1183 1184 I2C_READ 1185 1186 Code that returns TRUE if the I2C data line is high, 1187 FALSE if it is low. 1188 1189 eg: #define I2C_READ ((immr->im_cpm.cp_pbdat & PB_SDA) != 0) 1190 1191 I2C_SDA(bit) 1192 1193 If <bit> is TRUE, sets the I2C data line high. If it 1194 is FALSE, it clears it (low). 1195 1196 eg: #define I2C_SDA(bit) \ 1197 if(bit) immr->im_cpm.cp_pbdat |= PB_SDA; \ 1198 else immr->im_cpm.cp_pbdat &= ~PB_SDA 1199 1200 I2C_SCL(bit) 1201 1202 If <bit> is TRUE, sets the I2C clock line high. If it 1203 is FALSE, it clears it (low). 1204 1205 eg: #define I2C_SCL(bit) \ 1206 if(bit) immr->im_cpm.cp_pbdat |= PB_SCL; \ 1207 else immr->im_cpm.cp_pbdat &= ~PB_SCL 1208 1209 I2C_DELAY 1210 1211 This delay is invoked four times per clock cycle so this 1212 controls the rate of data transfer. The data rate thus 1213 is 1 / (I2C_DELAY * 4). Often defined to be something 1214 like: 1215 1216 #define I2C_DELAY udelay(2) 1217 1218 CFG_I2C_INIT_BOARD 1219 1220 When a board is reset during an i2c bus transfer 1221 chips might think that the current transfer is still 1222 in progress. On some boards it is possible to access 1223 the i2c SCLK line directly, either by using the 1224 processor pin as a GPIO or by having a second pin 1225 connected to the bus. If this option is defined a 1226 custom i2c_init_board() routine in boards/xxx/board.c 1227 is run early in the boot sequence. 1228 1229 CONFIG_I2CFAST (PPC405GP|PPC405EP only) 1230 1231 This option enables configuration of bi_iic_fast[] flags 1232 in u-boot bd_info structure based on u-boot environment 1233 variable "i2cfast". (see also i2cfast) 1234 1235- SPI Support: CONFIG_SPI 1236 1237 Enables SPI driver (so far only tested with 1238 SPI EEPROM, also an instance works with Crystal A/D and 1239 D/As on the SACSng board) 1240 1241 CONFIG_SPI_X 1242 1243 Enables extended (16-bit) SPI EEPROM addressing. 1244 (symmetrical to CONFIG_I2C_X) 1245 1246 CONFIG_SOFT_SPI 1247 1248 Enables a software (bit-bang) SPI driver rather than 1249 using hardware support. This is a general purpose 1250 driver that only requires three general I/O port pins 1251 (two outputs, one input) to function. If this is 1252 defined, the board configuration must define several 1253 SPI configuration items (port pins to use, etc). For 1254 an example, see include/configs/sacsng.h. 1255 1256- FPGA Support: CONFIG_FPGA_COUNT 1257 1258 Specify the number of FPGA devices to support. 1259 1260 CONFIG_FPGA 1261 1262 Used to specify the types of FPGA devices. For example, 1263 #define CONFIG_FPGA CFG_XILINX_VIRTEX2 1264 1265 CFG_FPGA_PROG_FEEDBACK 1266 1267 Enable printing of hash marks during FPGA configuration. 1268 1269 CFG_FPGA_CHECK_BUSY 1270 1271 Enable checks on FPGA configuration interface busy 1272 status by the configuration function. This option 1273 will require a board or device specific function to 1274 be written. 1275 1276 CONFIG_FPGA_DELAY 1277 1278 If defined, a function that provides delays in the FPGA 1279 configuration driver. 1280 1281 CFG_FPGA_CHECK_CTRLC 1282 Allow Control-C to interrupt FPGA configuration 1283 1284 CFG_FPGA_CHECK_ERROR 1285 1286 Check for configuration errors during FPGA bitfile 1287 loading. For example, abort during Virtex II 1288 configuration if the INIT_B line goes low (which 1289 indicated a CRC error). 1290 1291 CFG_FPGA_WAIT_INIT 1292 1293 Maximum time to wait for the INIT_B line to deassert 1294 after PROB_B has been deasserted during a Virtex II 1295 FPGA configuration sequence. The default time is 500 1296 mS. 1297 1298 CFG_FPGA_WAIT_BUSY 1299 1300 Maximum time to wait for BUSY to deassert during 1301 Virtex II FPGA configuration. The default is 5 mS. 1302 1303 CFG_FPGA_WAIT_CONFIG 1304 1305 Time to wait after FPGA configuration. The default is 1306 200 mS. 1307 1308- Configuration Management: 1309 CONFIG_IDENT_STRING 1310 1311 If defined, this string will be added to the U-Boot 1312 version information (U_BOOT_VERSION) 1313 1314- Vendor Parameter Protection: 1315 1316 U-Boot considers the values of the environment 1317 variables "serial#" (Board Serial Number) and 1318 "ethaddr" (Ethernet Address) to be parameters that 1319 are set once by the board vendor / manufacturer, and 1320 protects these variables from casual modification by 1321 the user. Once set, these variables are read-only, 1322 and write or delete attempts are rejected. You can 1323 change this behviour: 1324 1325 If CONFIG_ENV_OVERWRITE is #defined in your config 1326 file, the write protection for vendor parameters is 1327 completely disabled. Anybody can change or delete 1328 these parameters. 1329 1330 Alternatively, if you #define _both_ CONFIG_ETHADDR 1331 _and_ CONFIG_OVERWRITE_ETHADDR_ONCE, a default 1332 ethernet address is installed in the environment, 1333 which can be changed exactly ONCE by the user. [The 1334 serial# is unaffected by this, i. e. it remains 1335 read-only.] 1336 1337- Protected RAM: 1338 CONFIG_PRAM 1339 1340 Define this variable to enable the reservation of 1341 "protected RAM", i. e. RAM which is not overwritten 1342 by U-Boot. Define CONFIG_PRAM to hold the number of 1343 kB you want to reserve for pRAM. You can overwrite 1344 this default value by defining an environment 1345 variable "pram" to the number of kB you want to 1346 reserve. Note that the board info structure will 1347 still show the full amount of RAM. If pRAM is 1348 reserved, a new environment variable "mem" will 1349 automatically be defined to hold the amount of 1350 remaining RAM in a form that can be passed as boot 1351 argument to Linux, for instance like that: 1352 1353 setenv bootargs ... mem=\$(mem) 1354 saveenv 1355 1356 This way you can tell Linux not to use this memory, 1357 either, which results in a memory region that will 1358 not be affected by reboots. 1359 1360 *WARNING* If your board configuration uses automatic 1361 detection of the RAM size, you must make sure that 1362 this memory test is non-destructive. So far, the 1363 following board configurations are known to be 1364 "pRAM-clean": 1365 1366 ETX094, IVMS8, IVML24, SPD8xx, TQM8xxL, 1367 HERMES, IP860, RPXlite, LWMON, LANTEC, 1368 PCU_E, FLAGADM, TQM8260 1369 1370- Error Recovery: 1371 CONFIG_PANIC_HANG 1372 1373 Define this variable to stop the system in case of a 1374 fatal error, so that you have to reset it manually. 1375 This is probably NOT a good idea for an embedded 1376 system where you want to system to reboot 1377 automatically as fast as possible, but it may be 1378 useful during development since you can try to debug 1379 the conditions that lead to the situation. 1380 1381 CONFIG_NET_RETRY_COUNT 1382 1383 This variable defines the number of retries for 1384 network operations like ARP, RARP, TFTP, or BOOTP 1385 before giving up the operation. If not defined, a 1386 default value of 5 is used. 1387 1388- Command Interpreter: 1389 CFG_AUTO_COMPLETE 1390 1391 Enable auto completion of commands using TAB. 1392 1393 CFG_HUSH_PARSER 1394 1395 Define this variable to enable the "hush" shell (from 1396 Busybox) as command line interpreter, thus enabling 1397 powerful command line syntax like 1398 if...then...else...fi conditionals or `&&' and '||' 1399 constructs ("shell scripts"). 1400 1401 If undefined, you get the old, much simpler behaviour 1402 with a somewhat smaller memory footprint. 1403 1404 1405 CFG_PROMPT_HUSH_PS2 1406 1407 This defines the secondary prompt string, which is 1408 printed when the command interpreter needs more input 1409 to complete a command. Usually "> ". 1410 1411 Note: 1412 1413 In the current implementation, the local variables 1414 space and global environment variables space are 1415 separated. Local variables are those you define by 1416 simply typing `name=value'. To access a local 1417 variable later on, you have write `$name' or 1418 `${name}'; to execute the contents of a variable 1419 directly type `$name' at the command prompt. 1420 1421 Global environment variables are those you use 1422 setenv/printenv to work with. To run a command stored 1423 in such a variable, you need to use the run command, 1424 and you must not use the '$' sign to access them. 1425 1426 To store commands and special characters in a 1427 variable, please use double quotation marks 1428 surrounding the whole text of the variable, instead 1429 of the backslashes before semicolons and special 1430 symbols. 1431 1432- Default Environment: 1433 CONFIG_EXTRA_ENV_SETTINGS 1434 1435 Define this to contain any number of null terminated 1436 strings (variable = value pairs) that will be part of 1437 the default environment compiled into the boot image. 1438 1439 For example, place something like this in your 1440 board's config file: 1441 1442 #define CONFIG_EXTRA_ENV_SETTINGS \ 1443 "myvar1=value1\0" \ 1444 "myvar2=value2\0" 1445 1446 Warning: This method is based on knowledge about the 1447 internal format how the environment is stored by the 1448 U-Boot code. This is NOT an official, exported 1449 interface! Although it is unlikely that this format 1450 will change soon, there is no guarantee either. 1451 You better know what you are doing here. 1452 1453 Note: overly (ab)use of the default environment is 1454 discouraged. Make sure to check other ways to preset 1455 the environment like the autoscript function or the 1456 boot command first. 1457 1458- DataFlash Support: 1459 CONFIG_HAS_DATAFLASH 1460 1461 Defining this option enables DataFlash features and 1462 allows to read/write in Dataflash via the standard 1463 commands cp, md... 1464 1465- SystemACE Support: 1466 CONFIG_SYSTEMACE 1467 1468 Adding this option adds support for Xilinx SystemACE 1469 chips attached via some sort of local bus. The address 1470 of the chip must alsh be defined in the 1471 CFG_SYSTEMACE_BASE macro. For example: 1472 1473 #define CONFIG_SYSTEMACE 1474 #define CFG_SYSTEMACE_BASE 0xf0000000 1475 1476 When SystemACE support is added, the "ace" device type 1477 becomes available to the fat commands, i.e. fatls. 1478 1479- Show boot progress: 1480 CONFIG_SHOW_BOOT_PROGRESS 1481 1482 Defining this option allows to add some board- 1483 specific code (calling a user-provided function 1484 "show_boot_progress(int)") that enables you to show 1485 the system's boot progress on some display (for 1486 example, some LED's) on your board. At the moment, 1487 the following checkpoints are implemented: 1488 1489 Arg Where When 1490 1 common/cmd_bootm.c before attempting to boot an image 1491 -1 common/cmd_bootm.c Image header has bad magic number 1492 2 common/cmd_bootm.c Image header has correct magic number 1493 -2 common/cmd_bootm.c Image header has bad checksum 1494 3 common/cmd_bootm.c Image header has correct checksum 1495 -3 common/cmd_bootm.c Image data has bad checksum 1496 4 common/cmd_bootm.c Image data has correct checksum 1497 -4 common/cmd_bootm.c Image is for unsupported architecture 1498 5 common/cmd_bootm.c Architecture check OK 1499 -5 common/cmd_bootm.c Wrong Image Type (not kernel, multi, standalone) 1500 6 common/cmd_bootm.c Image Type check OK 1501 -6 common/cmd_bootm.c gunzip uncompression error 1502 -7 common/cmd_bootm.c Unimplemented compression type 1503 7 common/cmd_bootm.c Uncompression OK 1504 -8 common/cmd_bootm.c Wrong Image Type (not kernel, multi, standalone) 1505 8 common/cmd_bootm.c Image Type check OK 1506 -9 common/cmd_bootm.c Unsupported OS (not Linux, BSD, VxWorks, QNX) 1507 9 common/cmd_bootm.c Start initial ramdisk verification 1508 -10 common/cmd_bootm.c Ramdisk header has bad magic number 1509 -11 common/cmd_bootm.c Ramdisk header has bad checksum 1510 10 common/cmd_bootm.c Ramdisk header is OK 1511 -12 common/cmd_bootm.c Ramdisk data has bad checksum 1512 11 common/cmd_bootm.c Ramdisk data has correct checksum 1513 12 common/cmd_bootm.c Ramdisk verification complete, start loading 1514 -13 common/cmd_bootm.c Wrong Image Type (not PPC Linux Ramdisk) 1515 13 common/cmd_bootm.c Start multifile image verification 1516 14 common/cmd_bootm.c No initial ramdisk, no multifile, continue. 1517 15 common/cmd_bootm.c All preparation done, transferring control to OS 1518 1519 -30 lib_ppc/board.c Fatal error, hang the system 1520 -31 post/post.c POST test failed, detected by post_output_backlog() 1521 -32 post/post.c POST test failed, detected by post_run_single() 1522 1523 -1 common/cmd_doc.c Bad usage of "doc" command 1524 -1 common/cmd_doc.c No boot device 1525 -1 common/cmd_doc.c Unknown Chip ID on boot device 1526 -1 common/cmd_doc.c Read Error on boot device 1527 -1 common/cmd_doc.c Image header has bad magic number 1528 1529 -1 common/cmd_ide.c Bad usage of "ide" command 1530 -1 common/cmd_ide.c No boot device 1531 -1 common/cmd_ide.c Unknown boot device 1532 -1 common/cmd_ide.c Unknown partition table 1533 -1 common/cmd_ide.c Invalid partition type 1534 -1 common/cmd_ide.c Read Error on boot device 1535 -1 common/cmd_ide.c Image header has bad magic number 1536 1537 -1 common/cmd_nand.c Bad usage of "nand" command 1538 -1 common/cmd_nand.c No boot device 1539 -1 common/cmd_nand.c Unknown Chip ID on boot device 1540 -1 common/cmd_nand.c Read Error on boot device 1541 -1 common/cmd_nand.c Image header has bad magic number 1542 1543 -1 common/env_common.c Environment has a bad CRC, using default 1544 1545 1546Modem Support: 1547-------------- 1548 1549[so far only for SMDK2400 and TRAB boards] 1550 1551- Modem support endable: 1552 CONFIG_MODEM_SUPPORT 1553 1554- RTS/CTS Flow control enable: 1555 CONFIG_HWFLOW 1556 1557- Modem debug support: 1558 CONFIG_MODEM_SUPPORT_DEBUG 1559 1560 Enables debugging stuff (char screen[1024], dbg()) 1561 for modem support. Useful only with BDI2000. 1562 1563- Interrupt support (PPC): 1564 1565 There are common interrupt_init() and timer_interrupt() 1566 for all PPC archs. interrupt_init() calls interrupt_init_cpu() 1567 for cpu specific initialization. interrupt_init_cpu() 1568 should set decrementer_count to appropriate value. If 1569 cpu resets decrementer automatically after interrupt 1570 (ppc4xx) it should set decrementer_count to zero. 1571 timer_interrupt() calls timer_interrupt_cpu() for cpu 1572 specific handling. If board has watchdog / status_led 1573 / other_activity_monitor it works automatically from 1574 general timer_interrupt(). 1575 1576- General: 1577 1578 In the target system modem support is enabled when a 1579 specific key (key combination) is pressed during 1580 power-on. Otherwise U-Boot will boot normally 1581 (autoboot). The key_pressed() fuction is called from 1582 board_init(). Currently key_pressed() is a dummy 1583 function, returning 1 and thus enabling modem 1584 initialization. 1585 1586 If there are no modem init strings in the 1587 environment, U-Boot proceed to autoboot; the 1588 previous output (banner, info printfs) will be 1589 supressed, though. 1590 1591 See also: doc/README.Modem 1592 1593 1594Configuration Settings: 1595----------------------- 1596 1597- CFG_LONGHELP: Defined when you want long help messages included; 1598 undefine this when you're short of memory. 1599 1600- CFG_PROMPT: This is what U-Boot prints on the console to 1601 prompt for user input. 1602 1603- CFG_CBSIZE: Buffer size for input from the Console 1604 1605- CFG_PBSIZE: Buffer size for Console output 1606 1607- CFG_MAXARGS: max. Number of arguments accepted for monitor commands 1608 1609- CFG_BARGSIZE: Buffer size for Boot Arguments which are passed to 1610 the application (usually a Linux kernel) when it is 1611 booted 1612 1613- CFG_BAUDRATE_TABLE: 1614 List of legal baudrate settings for this board. 1615 1616- CFG_CONSOLE_INFO_QUIET 1617 Suppress display of console information at boot. 1618 1619- CFG_CONSOLE_IS_IN_ENV 1620 If the board specific function 1621 extern int overwrite_console (void); 1622 returns 1, the stdin, stderr and stdout are switched to the 1623 serial port, else the settings in the environment are used. 1624 1625- CFG_CONSOLE_OVERWRITE_ROUTINE 1626 Enable the call to overwrite_console(). 1627 1628- CFG_CONSOLE_ENV_OVERWRITE 1629 Enable overwrite of previous console environment settings. 1630 1631- CFG_MEMTEST_START, CFG_MEMTEST_END: 1632 Begin and End addresses of the area used by the 1633 simple memory test. 1634 1635- CFG_ALT_MEMTEST: 1636 Enable an alternate, more extensive memory test. 1637 1638- CFG_MEMTEST_SCRATCH: 1639 Scratch address used by the alternate memory test 1640 You only need to set this if address zero isn't writeable 1641 1642- CFG_TFTP_LOADADDR: 1643 Default load address for network file downloads 1644 1645- CFG_LOADS_BAUD_CHANGE: 1646 Enable temporary baudrate change while serial download 1647 1648- CFG_SDRAM_BASE: 1649 Physical start address of SDRAM. _Must_ be 0 here. 1650 1651- CFG_MBIO_BASE: 1652 Physical start address of Motherboard I/O (if using a 1653 Cogent motherboard) 1654 1655- CFG_FLASH_BASE: 1656 Physical start address of Flash memory. 1657 1658- CFG_MONITOR_BASE: 1659 Physical start address of boot monitor code (set by 1660 make config files to be same as the text base address 1661 (TEXT_BASE) used when linking) - same as 1662 CFG_FLASH_BASE when booting from flash. 1663 1664- CFG_MONITOR_LEN: 1665 Size of memory reserved for monitor code, used to 1666 determine _at_compile_time_ (!) if the environment is 1667 embedded within the U-Boot image, or in a separate 1668 flash sector. 1669 1670- CFG_MALLOC_LEN: 1671 Size of DRAM reserved for malloc() use. 1672 1673- CFG_BOOTMAPSZ: 1674 Maximum size of memory mapped by the startup code of 1675 the Linux kernel; all data that must be processed by 1676 the Linux kernel (bd_info, boot arguments, eventually 1677 initrd image) must be put below this limit. 1678 1679- CFG_MAX_FLASH_BANKS: 1680 Max number of Flash memory banks 1681 1682- CFG_MAX_FLASH_SECT: 1683 Max number of sectors on a Flash chip 1684 1685- CFG_FLASH_ERASE_TOUT: 1686 Timeout for Flash erase operations (in ms) 1687 1688- CFG_FLASH_WRITE_TOUT: 1689 Timeout for Flash write operations (in ms) 1690 1691- CFG_FLASH_LOCK_TOUT 1692 Timeout for Flash set sector lock bit operation (in ms) 1693 1694- CFG_FLASH_UNLOCK_TOUT 1695 Timeout for Flash clear lock bits operation (in ms) 1696 1697- CFG_FLASH_PROTECTION 1698 If defined, hardware flash sectors protection is used 1699 instead of U-Boot software protection. 1700 1701- CFG_DIRECT_FLASH_TFTP: 1702 1703 Enable TFTP transfers directly to flash memory; 1704 without this option such a download has to be 1705 performed in two steps: (1) download to RAM, and (2) 1706 copy from RAM to flash. 1707 1708 The two-step approach is usually more reliable, since 1709 you can check if the download worked before you erase 1710 the flash, but in some situations (when sytem RAM is 1711 too limited to allow for a tempory copy of the 1712 downloaded image) this option may be very useful. 1713 1714- CFG_FLASH_CFI: 1715 Define if the flash driver uses extra elements in the 1716 common flash structure for storing flash geometry. 1717 1718- CFG_FLASH_CFI_DRIVER 1719 This option also enables the building of the cfi_flash driver 1720 in the drivers directory 1721 1722- CFG_RX_ETH_BUFFER: 1723 Defines the number of ethernet receive buffers. On some 1724 ethernet controllers it is recommended to set this value 1725 to 8 or even higher (EEPRO100 or 405 EMAC), since all 1726 buffers can be full shortly after enabling the interface 1727 on high ethernet traffic. 1728 Defaults to 4 if not defined. 1729 1730The following definitions that deal with the placement and management 1731of environment data (variable area); in general, we support the 1732following configurations: 1733 1734- CFG_ENV_IS_IN_FLASH: 1735 1736 Define this if the environment is in flash memory. 1737 1738 a) The environment occupies one whole flash sector, which is 1739 "embedded" in the text segment with the U-Boot code. This 1740 happens usually with "bottom boot sector" or "top boot 1741 sector" type flash chips, which have several smaller 1742 sectors at the start or the end. For instance, such a 1743 layout can have sector sizes of 8, 2x4, 16, Nx32 kB. In 1744 such a case you would place the environment in one of the 1745 4 kB sectors - with U-Boot code before and after it. With 1746 "top boot sector" type flash chips, you would put the 1747 environment in one of the last sectors, leaving a gap 1748 between U-Boot and the environment. 1749 1750 - CFG_ENV_OFFSET: 1751 1752 Offset of environment data (variable area) to the 1753 beginning of flash memory; for instance, with bottom boot 1754 type flash chips the second sector can be used: the offset 1755 for this sector is given here. 1756 1757 CFG_ENV_OFFSET is used relative to CFG_FLASH_BASE. 1758 1759 - CFG_ENV_ADDR: 1760 1761 This is just another way to specify the start address of 1762 the flash sector containing the environment (instead of 1763 CFG_ENV_OFFSET). 1764 1765 - CFG_ENV_SECT_SIZE: 1766 1767 Size of the sector containing the environment. 1768 1769 1770 b) Sometimes flash chips have few, equal sized, BIG sectors. 1771 In such a case you don't want to spend a whole sector for 1772 the environment. 1773 1774 - CFG_ENV_SIZE: 1775 1776 If you use this in combination with CFG_ENV_IS_IN_FLASH 1777 and CFG_ENV_SECT_SIZE, you can specify to use only a part 1778 of this flash sector for the environment. This saves 1779 memory for the RAM copy of the environment. 1780 1781 It may also save flash memory if you decide to use this 1782 when your environment is "embedded" within U-Boot code, 1783 since then the remainder of the flash sector could be used 1784 for U-Boot code. It should be pointed out that this is 1785 STRONGLY DISCOURAGED from a robustness point of view: 1786 updating the environment in flash makes it always 1787 necessary to erase the WHOLE sector. If something goes 1788 wrong before the contents has been restored from a copy in 1789 RAM, your target system will be dead. 1790 1791 - CFG_ENV_ADDR_REDUND 1792 CFG_ENV_SIZE_REDUND 1793 1794 These settings describe a second storage area used to hold 1795 a redundand copy of the environment data, so that there is 1796 a valid backup copy in case there is a power failure during 1797 a "saveenv" operation. 1798 1799BE CAREFUL! Any changes to the flash layout, and some changes to the 1800source code will make it necessary to adapt <board>/u-boot.lds* 1801accordingly! 1802 1803 1804- CFG_ENV_IS_IN_NVRAM: 1805 1806 Define this if you have some non-volatile memory device 1807 (NVRAM, battery buffered SRAM) which you want to use for the 1808 environment. 1809 1810 - CFG_ENV_ADDR: 1811 - CFG_ENV_SIZE: 1812 1813 These two #defines are used to determin the memory area you 1814 want to use for environment. It is assumed that this memory 1815 can just be read and written to, without any special 1816 provision. 1817 1818BE CAREFUL! The first access to the environment happens quite early 1819in U-Boot initalization (when we try to get the setting of for the 1820console baudrate). You *MUST* have mappend your NVRAM area then, or 1821U-Boot will hang. 1822 1823Please note that even with NVRAM we still use a copy of the 1824environment in RAM: we could work on NVRAM directly, but we want to 1825keep settings there always unmodified except somebody uses "saveenv" 1826to save the current settings. 1827 1828 1829- CFG_ENV_IS_IN_EEPROM: 1830 1831 Use this if you have an EEPROM or similar serial access 1832 device and a driver for it. 1833 1834 - CFG_ENV_OFFSET: 1835 - CFG_ENV_SIZE: 1836 1837 These two #defines specify the offset and size of the 1838 environment area within the total memory of your EEPROM. 1839 1840 - CFG_I2C_EEPROM_ADDR: 1841 If defined, specified the chip address of the EEPROM device. 1842 The default address is zero. 1843 1844 - CFG_EEPROM_PAGE_WRITE_BITS: 1845 If defined, the number of bits used to address bytes in a 1846 single page in the EEPROM device. A 64 byte page, for example 1847 would require six bits. 1848 1849 - CFG_EEPROM_PAGE_WRITE_DELAY_MS: 1850 If defined, the number of milliseconds to delay between 1851 page writes. The default is zero milliseconds. 1852 1853 - CFG_I2C_EEPROM_ADDR_LEN: 1854 The length in bytes of the EEPROM memory array address. Note 1855 that this is NOT the chip address length! 1856 1857 - CFG_I2C_EEPROM_ADDR_OVERFLOW: 1858 EEPROM chips that implement "address overflow" are ones 1859 like Catalyst 24WC04/08/16 which has 9/10/11 bits of 1860 address and the extra bits end up in the "chip address" bit 1861 slots. This makes a 24WC08 (1Kbyte) chip look like four 256 1862 byte chips. 1863 1864 Note that we consider the length of the address field to 1865 still be one byte because the extra address bits are hidden 1866 in the chip address. 1867 1868 - CFG_EEPROM_SIZE: 1869 The size in bytes of the EEPROM device. 1870 1871 1872- CFG_ENV_IS_IN_DATAFLASH: 1873 1874 Define this if you have a DataFlash memory device which you 1875 want to use for the environment. 1876 1877 - CFG_ENV_OFFSET: 1878 - CFG_ENV_ADDR: 1879 - CFG_ENV_SIZE: 1880 1881 These three #defines specify the offset and size of the 1882 environment area within the total memory of your DataFlash placed 1883 at the specified address. 1884 1885- CFG_ENV_IS_IN_NAND: 1886 1887 Define this if you have a NAND device which you want to use 1888 for the environment. 1889 1890 - CFG_ENV_OFFSET: 1891 - CFG_ENV_SIZE: 1892 1893 These two #defines specify the offset and size of the environment 1894 area within the first NAND device. 1895 1896- CFG_SPI_INIT_OFFSET 1897 1898 Defines offset to the initial SPI buffer area in DPRAM. The 1899 area is used at an early stage (ROM part) if the environment 1900 is configured to reside in the SPI EEPROM: We need a 520 byte 1901 scratch DPRAM area. It is used between the two initialization 1902 calls (spi_init_f() and spi_init_r()). A value of 0xB00 seems 1903 to be a good choice since it makes it far enough from the 1904 start of the data area as well as from the stack pointer. 1905 1906Please note that the environment is read-only as long as the monitor 1907has been relocated to RAM and a RAM copy of the environment has been 1908created; also, when using EEPROM you will have to use getenv_r() 1909until then to read environment variables. 1910 1911The environment is protected by a CRC32 checksum. Before the monitor 1912is relocated into RAM, as a result of a bad CRC you will be working 1913with the compiled-in default environment - *silently*!!! [This is 1914necessary, because the first environment variable we need is the 1915"baudrate" setting for the console - if we have a bad CRC, we don't 1916have any device yet where we could complain.] 1917 1918Note: once the monitor has been relocated, then it will complain if 1919the default environment is used; a new CRC is computed as soon as you 1920use the "saveenv" command to store a valid environment. 1921 1922- CFG_FAULT_ECHO_LINK_DOWN: 1923 Echo the inverted Ethernet link state to the fault LED. 1924 1925 Note: If this option is active, then CFG_FAULT_MII_ADDR 1926 also needs to be defined. 1927 1928- CFG_FAULT_MII_ADDR: 1929 MII address of the PHY to check for the Ethernet link state. 1930 1931- CFG_64BIT_VSPRINTF: 1932 Makes vsprintf (and all *printf functions) support printing 1933 of 64bit values by using the L quantifier 1934 1935- CFG_64BIT_STRTOUL: 1936 Adds simple_strtoull that returns a 64bit value 1937 1938Low Level (hardware related) configuration options: 1939--------------------------------------------------- 1940 1941- CFG_CACHELINE_SIZE: 1942 Cache Line Size of the CPU. 1943 1944- CFG_DEFAULT_IMMR: 1945 Default address of the IMMR after system reset. 1946 1947 Needed on some 8260 systems (MPC8260ADS, PQ2FADS-ZU, 1948 and RPXsuper) to be able to adjust the position of 1949 the IMMR register after a reset. 1950 1951- Floppy Disk Support: 1952 CFG_FDC_DRIVE_NUMBER 1953 1954 the default drive number (default value 0) 1955 1956 CFG_ISA_IO_STRIDE 1957 1958 defines the spacing between fdc chipset registers 1959 (default value 1) 1960 1961 CFG_ISA_IO_OFFSET 1962 1963 defines the offset of register from address. It 1964 depends on which part of the data bus is connected to 1965 the fdc chipset. (default value 0) 1966 1967 If CFG_ISA_IO_STRIDE CFG_ISA_IO_OFFSET and 1968 CFG_FDC_DRIVE_NUMBER are undefined, they take their 1969 default value. 1970 1971 if CFG_FDC_HW_INIT is defined, then the function 1972 fdc_hw_init() is called at the beginning of the FDC 1973 setup. fdc_hw_init() must be provided by the board 1974 source code. It is used to make hardware dependant 1975 initializations. 1976 1977- CFG_IMMR: Physical address of the Internal Memory Mapped 1978 Register; DO NOT CHANGE! (11-4) 1979 [MPC8xx systems only] 1980 1981- CFG_INIT_RAM_ADDR: 1982 1983 Start address of memory area that can be used for 1984 initial data and stack; please note that this must be 1985 writable memory that is working WITHOUT special 1986 initialization, i. e. you CANNOT use normal RAM which 1987 will become available only after programming the 1988 memory controller and running certain initialization 1989 sequences. 1990 1991 U-Boot uses the following memory types: 1992 - MPC8xx and MPC8260: IMMR (internal memory of the CPU) 1993 - MPC824X: data cache 1994 - PPC4xx: data cache 1995 1996- CFG_GBL_DATA_OFFSET: 1997 1998 Offset of the initial data structure in the memory 1999 area defined by CFG_INIT_RAM_ADDR. Usually 2000 CFG_GBL_DATA_OFFSET is chosen such that the initial 2001 data is located at the end of the available space 2002 (sometimes written as (CFG_INIT_RAM_END - 2003 CFG_INIT_DATA_SIZE), and the initial stack is just 2004 below that area (growing from (CFG_INIT_RAM_ADDR + 2005 CFG_GBL_DATA_OFFSET) downward. 2006 2007 Note: 2008 On the MPC824X (or other systems that use the data 2009 cache for initial memory) the address chosen for 2010 CFG_INIT_RAM_ADDR is basically arbitrary - it must 2011 point to an otherwise UNUSED address space between 2012 the top of RAM and the start of the PCI space. 2013 2014- CFG_SIUMCR: SIU Module Configuration (11-6) 2015 2016- CFG_SYPCR: System Protection Control (11-9) 2017 2018- CFG_TBSCR: Time Base Status and Control (11-26) 2019 2020- CFG_PISCR: Periodic Interrupt Status and Control (11-31) 2021 2022- CFG_PLPRCR: PLL, Low-Power, and Reset Control Register (15-30) 2023 2024- CFG_SCCR: System Clock and reset Control Register (15-27) 2025 2026- CFG_OR_TIMING_SDRAM: 2027 SDRAM timing 2028 2029- CFG_MAMR_PTA: 2030 periodic timer for refresh 2031 2032- CFG_DER: Debug Event Register (37-47) 2033 2034- FLASH_BASE0_PRELIM, FLASH_BASE1_PRELIM, CFG_REMAP_OR_AM, 2035 CFG_PRELIM_OR_AM, CFG_OR_TIMING_FLASH, CFG_OR0_REMAP, 2036 CFG_OR0_PRELIM, CFG_BR0_PRELIM, CFG_OR1_REMAP, CFG_OR1_PRELIM, 2037 CFG_BR1_PRELIM: 2038 Memory Controller Definitions: BR0/1 and OR0/1 (FLASH) 2039 2040- SDRAM_BASE2_PRELIM, SDRAM_BASE3_PRELIM, SDRAM_MAX_SIZE, 2041 CFG_OR_TIMING_SDRAM, CFG_OR2_PRELIM, CFG_BR2_PRELIM, 2042 CFG_OR3_PRELIM, CFG_BR3_PRELIM: 2043 Memory Controller Definitions: BR2/3 and OR2/3 (SDRAM) 2044 2045- CFG_MAMR_PTA, CFG_MPTPR_2BK_4K, CFG_MPTPR_1BK_4K, CFG_MPTPR_2BK_8K, 2046 CFG_MPTPR_1BK_8K, CFG_MAMR_8COL, CFG_MAMR_9COL: 2047 Machine Mode Register and Memory Periodic Timer 2048 Prescaler definitions (SDRAM timing) 2049 2050- CFG_I2C_UCODE_PATCH, CFG_I2C_DPMEM_OFFSET [0x1FC0]: 2051 enable I2C microcode relocation patch (MPC8xx); 2052 define relocation offset in DPRAM [DSP2] 2053 2054- CFG_SPI_UCODE_PATCH, CFG_SPI_DPMEM_OFFSET [0x1FC0]: 2055 enable SPI microcode relocation patch (MPC8xx); 2056 define relocation offset in DPRAM [SCC4] 2057 2058- CFG_USE_OSCCLK: 2059 Use OSCM clock mode on MBX8xx board. Be careful, 2060 wrong setting might damage your board. Read 2061 doc/README.MBX before setting this variable! 2062 2063- CFG_CPM_POST_WORD_ADDR: (MPC8xx, MPC8260 only) 2064 Offset of the bootmode word in DPRAM used by post 2065 (Power On Self Tests). This definition overrides 2066 #define'd default value in commproc.h resp. 2067 cpm_8260.h. 2068 2069- CFG_PCI_SLV_MEM_LOCAL, CFG_PCI_SLV_MEM_BUS, CFG_PICMR0_MASK_ATTRIB, 2070 CFG_PCI_MSTR0_LOCAL, CFG_PCIMSK0_MASK, CFG_PCI_MSTR1_LOCAL, 2071 CFG_PCIMSK1_MASK, CFG_PCI_MSTR_MEM_LOCAL, CFG_PCI_MSTR_MEM_BUS, 2072 CFG_CPU_PCI_MEM_START, CFG_PCI_MSTR_MEM_SIZE, CFG_POCMR0_MASK_ATTRIB, 2073 CFG_PCI_MSTR_MEMIO_LOCAL, CFG_PCI_MSTR_MEMIO_BUS, CPU_PCI_MEMIO_START, 2074 CFG_PCI_MSTR_MEMIO_SIZE, CFG_POCMR1_MASK_ATTRIB, CFG_PCI_MSTR_IO_LOCAL, 2075 CFG_PCI_MSTR_IO_BUS, CFG_CPU_PCI_IO_START, CFG_PCI_MSTR_IO_SIZE, 2076 CFG_POCMR2_MASK_ATTRIB: (MPC826x only) 2077 Overrides the default PCI memory map in cpu/mpc8260/pci.c if set. 2078 2079- CONFIG_ETHER_ON_FEC[12] 2080 Define to enable FEC[12] on a 8xx series processor. 2081 2082- CONFIG_FEC[12]_PHY 2083 Define to the hardcoded PHY address which corresponds 2084 to the given FEC; i. e. 2085 #define CONFIG_FEC1_PHY 4 2086 means that the PHY with address 4 is connected to FEC1 2087 2088 When set to -1, means to probe for first available. 2089 2090- CONFIG_FEC[12]_PHY_NORXERR 2091 The PHY does not have a RXERR line (RMII only). 2092 (so program the FEC to ignore it). 2093 2094- CONFIG_RMII 2095 Enable RMII mode for all FECs. 2096 Note that this is a global option, we can't 2097 have one FEC in standard MII mode and another in RMII mode. 2098 2099- CONFIG_CRC32_VERIFY 2100 Add a verify option to the crc32 command. 2101 The syntax is: 2102 2103 => crc32 -v <address> <count> <crc32> 2104 2105 Where address/count indicate a memory area 2106 and crc32 is the correct crc32 which the 2107 area should have. 2108 2109- CONFIG_LOOPW 2110 Add the "loopw" memory command. This only takes effect if 2111 the memory commands are activated globally (CFG_CMD_MEM). 2112 2113Building the Software: 2114====================== 2115 2116Building U-Boot has been tested in native PPC environments (on a 2117PowerBook G3 running LinuxPPC 2000) and in cross environments 2118(running RedHat 6.x and 7.x Linux on x86, Solaris 2.6 on a SPARC, and 2119NetBSD 1.5 on x86). 2120 2121If you are not using a native PPC environment, it is assumed that you 2122have the GNU cross compiling tools available in your path and named 2123with a prefix of "powerpc-linux-". If this is not the case, (e.g. if 2124you are using Monta Vista's Hard Hat Linux CDK 1.2) you must change 2125the definition of CROSS_COMPILE in Makefile. For HHL on a 4xx CPU, 2126change it to: 2127 2128 CROSS_COMPILE = ppc_4xx- 2129 2130 2131U-Boot is intended to be simple to build. After installing the 2132sources you must configure U-Boot for one specific board type. This 2133is done by typing: 2134 2135 make NAME_config 2136 2137where "NAME_config" is the name of one of the existing 2138configurations; the following names are supported: 2139 2140 ADCIOP_config FPS860L_config omap730p2_config 2141 ADS860_config GEN860T_config pcu_e_config 2142 AR405_config GENIETV_config PIP405_config 2143 at91rm9200dk_config GTH_config QS823_config 2144 CANBT_config hermes_config QS850_config 2145 cmi_mpc5xx_config hymod_config QS860T_config 2146 cogent_common_config IP860_config RPXlite_config 2147 cogent_mpc8260_config IVML24_config RPXlite_DW_config 2148 cogent_mpc8xx_config IVMS8_config RPXsuper_config 2149 CPCI405_config JSE_config rsdproto_config 2150 CPCIISER4_config LANTEC_config Sandpoint8240_config 2151 csb272_config lwmon_config sbc8260_config 2152 CU824_config MBX860T_config sbc8560_33_config 2153 DUET_ADS_config MBX_config sbc8560_66_config 2154 EBONY_config MPC8260ADS_config SM850_config 2155 ELPT860_config MPC8540ADS_config SPD823TS_config 2156 ESTEEM192E_config MPC8560ADS_config stxgp3_config 2157 ETX094_config NETVIA_config SXNI855T_config 2158 FADS823_config omap1510inn_config TQM823L_config 2159 FADS850SAR_config omap1610h2_config TQM850L_config 2160 FADS860T_config omap1610inn_config TQM855L_config 2161 FPS850L_config omap5912osk_config TQM860L_config 2162 WALNUT405_config 2163 ZPC1900_config 2164 2165Note: for some board special configuration names may exist; check if 2166 additional information is available from the board vendor; for 2167 instance, the TQM823L systems are available without (standard) 2168 or with LCD support. You can select such additional "features" 2169 when chosing the configuration, i. e. 2170 2171 make TQM823L_config 2172 - will configure for a plain TQM823L, i. e. no LCD support 2173 2174 make TQM823L_LCD_config 2175 - will configure for a TQM823L with U-Boot console on LCD 2176 2177 etc. 2178 2179 2180Finally, type "make all", and you should get some working U-Boot 2181images ready for download to / installation on your system: 2182 2183- "u-boot.bin" is a raw binary image 2184- "u-boot" is an image in ELF binary format 2185- "u-boot.srec" is in Motorola S-Record format 2186 2187 2188Please be aware that the Makefiles assume you are using GNU make, so 2189for instance on NetBSD you might need to use "gmake" instead of 2190native "make". 2191 2192 2193If the system board that you have is not listed, then you will need 2194to port U-Boot to your hardware platform. To do this, follow these 2195steps: 2196 21971. Add a new configuration option for your board to the toplevel 2198 "Makefile" and to the "MAKEALL" script, using the existing 2199 entries as examples. Note that here and at many other places 2200 boards and other names are listed in alphabetical sort order. Please 2201 keep this order. 22022. Create a new directory to hold your board specific code. Add any 2203 files you need. In your board directory, you will need at least 2204 the "Makefile", a "<board>.c", "flash.c" and "u-boot.lds". 22053. Create a new configuration file "include/configs/<board>.h" for 2206 your board 22073. If you're porting U-Boot to a new CPU, then also create a new 2208 directory to hold your CPU specific code. Add any files you need. 22094. Run "make <board>_config" with your new name. 22105. Type "make", and you should get a working "u-boot.srec" file 2211 to be installed on your target system. 22126. Debug and solve any problems that might arise. 2213 [Of course, this last step is much harder than it sounds.] 2214 2215 2216Testing of U-Boot Modifications, Ports to New Hardware, etc.: 2217============================================================== 2218 2219If you have modified U-Boot sources (for instance added a new board 2220or support for new devices, a new CPU, etc.) you are expected to 2221provide feedback to the other developers. The feedback normally takes 2222the form of a "patch", i. e. a context diff against a certain (latest 2223official or latest in CVS) version of U-Boot sources. 2224 2225But before you submit such a patch, please verify that your modifi- 2226cation did not break existing code. At least make sure that *ALL* of 2227the supported boards compile WITHOUT ANY compiler warnings. To do so, 2228just run the "MAKEALL" script, which will configure and build U-Boot 2229for ALL supported system. Be warned, this will take a while. You can 2230select which (cross) compiler to use by passing a `CROSS_COMPILE' 2231environment variable to the script, i. e. to use the cross tools from 2232MontaVista's Hard Hat Linux you can type 2233 2234 CROSS_COMPILE=ppc_8xx- MAKEALL 2235 2236or to build on a native PowerPC system you can type 2237 2238 CROSS_COMPILE=' ' MAKEALL 2239 2240See also "U-Boot Porting Guide" below. 2241 2242 2243Monitor Commands - Overview: 2244============================ 2245 2246go - start application at address 'addr' 2247run - run commands in an environment variable 2248bootm - boot application image from memory 2249bootp - boot image via network using BootP/TFTP protocol 2250tftpboot- boot image via network using TFTP protocol 2251 and env variables "ipaddr" and "serverip" 2252 (and eventually "gatewayip") 2253rarpboot- boot image via network using RARP/TFTP protocol 2254diskboot- boot from IDE devicebootd - boot default, i.e., run 'bootcmd' 2255loads - load S-Record file over serial line 2256loadb - load binary file over serial line (kermit mode) 2257md - memory display 2258mm - memory modify (auto-incrementing) 2259nm - memory modify (constant address) 2260mw - memory write (fill) 2261cp - memory copy 2262cmp - memory compare 2263crc32 - checksum calculation 2264imd - i2c memory display 2265imm - i2c memory modify (auto-incrementing) 2266inm - i2c memory modify (constant address) 2267imw - i2c memory write (fill) 2268icrc32 - i2c checksum calculation 2269iprobe - probe to discover valid I2C chip addresses 2270iloop - infinite loop on address range 2271isdram - print SDRAM configuration information 2272sspi - SPI utility commands 2273base - print or set address offset 2274printenv- print environment variables 2275setenv - set environment variables 2276saveenv - save environment variables to persistent storage 2277protect - enable or disable FLASH write protection 2278erase - erase FLASH memory 2279flinfo - print FLASH memory information 2280bdinfo - print Board Info structure 2281iminfo - print header information for application image 2282coninfo - print console devices and informations 2283ide - IDE sub-system 2284loop - infinite loop on address range 2285loopw - infinite write loop on address range 2286mtest - simple RAM test 2287icache - enable or disable instruction cache 2288dcache - enable or disable data cache 2289reset - Perform RESET of the CPU 2290echo - echo args to console 2291version - print monitor version 2292help - print online help 2293? - alias for 'help' 2294 2295 2296Monitor Commands - Detailed Description: 2297======================================== 2298 2299TODO. 2300 2301For now: just type "help <command>". 2302 2303 2304Environment Variables: 2305====================== 2306 2307U-Boot supports user configuration using Environment Variables which 2308can be made persistent by saving to Flash memory. 2309 2310Environment Variables are set using "setenv", printed using 2311"printenv", and saved to Flash using "saveenv". Using "setenv" 2312without a value can be used to delete a variable from the 2313environment. As long as you don't save the environment you are 2314working with an in-memory copy. In case the Flash area containing the 2315environment is erased by accident, a default environment is provided. 2316 2317Some configuration options can be set using Environment Variables: 2318 2319 baudrate - see CONFIG_BAUDRATE 2320 2321 bootdelay - see CONFIG_BOOTDELAY 2322 2323 bootcmd - see CONFIG_BOOTCOMMAND 2324 2325 bootargs - Boot arguments when booting an RTOS image 2326 2327 bootfile - Name of the image to load with TFTP 2328 2329 autoload - if set to "no" (any string beginning with 'n'), 2330 "bootp" will just load perform a lookup of the 2331 configuration from the BOOTP server, but not try to 2332 load any image using TFTP 2333 2334 autostart - if set to "yes", an image loaded using the "bootp", 2335 "rarpboot", "tftpboot" or "diskboot" commands will 2336 be automatically started (by internally calling 2337 "bootm") 2338 2339 If set to "no", a standalone image passed to the 2340 "bootm" command will be copied to the load address 2341 (and eventually uncompressed), but NOT be started. 2342 This can be used to load and uncompress arbitrary 2343 data. 2344 2345 i2cfast - (PPC405GP|PPC405EP only) 2346 if set to 'y' configures Linux I2C driver for fast 2347 mode (400kHZ). This environment variable is used in 2348 initialization code. So, for changes to be effective 2349 it must be saved and board must be reset. 2350 2351 initrd_high - restrict positioning of initrd images: 2352 If this variable is not set, initrd images will be 2353 copied to the highest possible address in RAM; this 2354 is usually what you want since it allows for 2355 maximum initrd size. If for some reason you want to 2356 make sure that the initrd image is loaded below the 2357 CFG_BOOTMAPSZ limit, you can set this environment 2358 variable to a value of "no" or "off" or "0". 2359 Alternatively, you can set it to a maximum upper 2360 address to use (U-Boot will still check that it 2361 does not overwrite the U-Boot stack and data). 2362 2363 For instance, when you have a system with 16 MB 2364 RAM, and want to reserve 4 MB from use by Linux, 2365 you can do this by adding "mem=12M" to the value of 2366 the "bootargs" variable. However, now you must make 2367 sure that the initrd image is placed in the first 2368 12 MB as well - this can be done with 2369 2370 setenv initrd_high 00c00000 2371 2372 If you set initrd_high to 0xFFFFFFFF, this is an 2373 indication to U-Boot that all addresses are legal 2374 for the Linux kernel, including addresses in flash 2375 memory. In this case U-Boot will NOT COPY the 2376 ramdisk at all. This may be useful to reduce the 2377 boot time on your system, but requires that this 2378 feature is supported by your Linux kernel. 2379 2380 ipaddr - IP address; needed for tftpboot command 2381 2382 loadaddr - Default load address for commands like "bootp", 2383 "rarpboot", "tftpboot", "loadb" or "diskboot" 2384 2385 loads_echo - see CONFIG_LOADS_ECHO 2386 2387 serverip - TFTP server IP address; needed for tftpboot command 2388 2389 bootretry - see CONFIG_BOOT_RETRY_TIME 2390 2391 bootdelaykey - see CONFIG_AUTOBOOT_DELAY_STR 2392 2393 bootstopkey - see CONFIG_AUTOBOOT_STOP_STR 2394 2395 ethprime - When CONFIG_NET_MULTI is enabled controls which 2396 interface is used first. 2397 2398 ethact - When CONFIG_NET_MULTI is enabled controls which 2399 interface is currently active. For example you 2400 can do the following 2401 2402 => setenv ethact FEC ETHERNET 2403 => ping 192.168.0.1 # traffic sent on FEC ETHERNET 2404 => setenv ethact SCC ETHERNET 2405 => ping 10.0.0.1 # traffic sent on SCC ETHERNET 2406 2407 netretry - When set to "no" each network operation will 2408 either succeed or fail without retrying. 2409 When set to "once" the network operation will 2410 fail when all the available network interfaces 2411 are tried once without success. 2412 Useful on scripts which control the retry operation 2413 themselves. 2414 2415 vlan - When set to a value < 4095 the traffic over 2416 ethernet is encapsulated/received over 802.1q 2417 VLAN tagged frames. 2418 2419The following environment variables may be used and automatically 2420updated by the network boot commands ("bootp" and "rarpboot"), 2421depending the information provided by your boot server: 2422 2423 bootfile - see above 2424 dnsip - IP address of your Domain Name Server 2425 dnsip2 - IP address of your secondary Domain Name Server 2426 gatewayip - IP address of the Gateway (Router) to use 2427 hostname - Target hostname 2428 ipaddr - see above 2429 netmask - Subnet Mask 2430 rootpath - Pathname of the root filesystem on the NFS server 2431 serverip - see above 2432 2433 2434There are two special Environment Variables: 2435 2436 serial# - contains hardware identification information such 2437 as type string and/or serial number 2438 ethaddr - Ethernet address 2439 2440These variables can be set only once (usually during manufacturing of 2441the board). U-Boot refuses to delete or overwrite these variables 2442once they have been set once. 2443 2444 2445Further special Environment Variables: 2446 2447 ver - Contains the U-Boot version string as printed 2448 with the "version" command. This variable is 2449 readonly (see CONFIG_VERSION_VARIABLE). 2450 2451 2452Please note that changes to some configuration parameters may take 2453only effect after the next boot (yes, that's just like Windoze :-). 2454 2455 2456Command Line Parsing: 2457===================== 2458 2459There are two different command line parsers available with U-Boot: 2460the old "simple" one, and the much more powerful "hush" shell: 2461 2462Old, simple command line parser: 2463-------------------------------- 2464 2465- supports environment variables (through setenv / saveenv commands) 2466- several commands on one line, separated by ';' 2467- variable substitution using "... $(name) ..." syntax 2468- special characters ('$', ';') can be escaped by prefixing with '\', 2469 for example: 2470 setenv bootcmd bootm \$(address) 2471- You can also escape text by enclosing in single apostrophes, for example: 2472 setenv addip 'setenv bootargs $bootargs ip=$ipaddr:$serverip:$gatewayip:$netmask:$hostname::off' 2473 2474Hush shell: 2475----------- 2476 2477- similar to Bourne shell, with control structures like 2478 if...then...else...fi, for...do...done; while...do...done, 2479 until...do...done, ... 2480- supports environment ("global") variables (through setenv / saveenv 2481 commands) and local shell variables (through standard shell syntax 2482 "name=value"); only environment variables can be used with "run" 2483 command 2484 2485General rules: 2486-------------- 2487 2488(1) If a command line (or an environment variable executed by a "run" 2489 command) contains several commands separated by semicolon, and 2490 one of these commands fails, then the remaining commands will be 2491 executed anyway. 2492 2493(2) If you execute several variables with one call to run (i. e. 2494 calling run with a list af variables as arguments), any failing 2495 command will cause "run" to terminate, i. e. the remaining 2496 variables are not executed. 2497 2498Note for Redundant Ethernet Interfaces: 2499======================================= 2500 2501Some boards come with redundant ethernet interfaces; U-Boot supports 2502such configurations and is capable of automatic selection of a 2503"working" interface when needed. MAC assignment works as follows: 2504 2505Network interfaces are numbered eth0, eth1, eth2, ... Corresponding 2506MAC addresses can be stored in the environment as "ethaddr" (=>eth0), 2507"eth1addr" (=>eth1), "eth2addr", ... 2508 2509If the network interface stores some valid MAC address (for instance 2510in SROM), this is used as default address if there is NO correspon- 2511ding setting in the environment; if the corresponding environment 2512variable is set, this overrides the settings in the card; that means: 2513 2514o If the SROM has a valid MAC address, and there is no address in the 2515 environment, the SROM's address is used. 2516 2517o If there is no valid address in the SROM, and a definition in the 2518 environment exists, then the value from the environment variable is 2519 used. 2520 2521o If both the SROM and the environment contain a MAC address, and 2522 both addresses are the same, this MAC address is used. 2523 2524o If both the SROM and the environment contain a MAC address, and the 2525 addresses differ, the value from the environment is used and a 2526 warning is printed. 2527 2528o If neither SROM nor the environment contain a MAC address, an error 2529 is raised. 2530 2531 2532Image Formats: 2533============== 2534 2535The "boot" commands of this monitor operate on "image" files which 2536can be basicly anything, preceeded by a special header; see the 2537definitions in include/image.h for details; basicly, the header 2538defines the following image properties: 2539 2540* Target Operating System (Provisions for OpenBSD, NetBSD, FreeBSD, 2541 4.4BSD, Linux, SVR4, Esix, Solaris, Irix, SCO, Dell, NCR, VxWorks, 2542 LynxOS, pSOS, QNX, RTEMS, ARTOS; 2543 Currently supported: Linux, NetBSD, VxWorks, QNX, RTEMS, ARTOS, LynxOS). 2544* Target CPU Architecture (Provisions for Alpha, ARM, Intel x86, 2545 IA64, MIPS, NIOS, PowerPC, IBM S390, SuperH, Sparc, Sparc 64 Bit; 2546 Currently supported: ARM, Intel x86, MIPS, NIOS, PowerPC). 2547* Compression Type (uncompressed, gzip, bzip2) 2548* Load Address 2549* Entry Point 2550* Image Name 2551* Image Timestamp 2552 2553The header is marked by a special Magic Number, and both the header 2554and the data portions of the image are secured against corruption by 2555CRC32 checksums. 2556 2557 2558Linux Support: 2559============== 2560 2561Although U-Boot should support any OS or standalone application 2562easily, the main focus has always been on Linux during the design of 2563U-Boot. 2564 2565U-Boot includes many features that so far have been part of some 2566special "boot loader" code within the Linux kernel. Also, any 2567"initrd" images to be used are no longer part of one big Linux image; 2568instead, kernel and "initrd" are separate images. This implementation 2569serves several purposes: 2570 2571- the same features can be used for other OS or standalone 2572 applications (for instance: using compressed images to reduce the 2573 Flash memory footprint) 2574 2575- it becomes much easier to port new Linux kernel versions because 2576 lots of low-level, hardware dependent stuff are done by U-Boot 2577 2578- the same Linux kernel image can now be used with different "initrd" 2579 images; of course this also means that different kernel images can 2580 be run with the same "initrd". This makes testing easier (you don't 2581 have to build a new "zImage.initrd" Linux image when you just 2582 change a file in your "initrd"). Also, a field-upgrade of the 2583 software is easier now. 2584 2585 2586Linux HOWTO: 2587============ 2588 2589Porting Linux to U-Boot based systems: 2590--------------------------------------- 2591 2592U-Boot cannot save you from doing all the necessary modifications to 2593configure the Linux device drivers for use with your target hardware 2594(no, we don't intend to provide a full virtual machine interface to 2595Linux :-). 2596 2597But now you can ignore ALL boot loader code (in arch/ppc/mbxboot). 2598 2599Just make sure your machine specific header file (for instance 2600include/asm-ppc/tqm8xx.h) includes the same definition of the Board 2601Information structure as we define in include/u-boot.h, and make 2602sure that your definition of IMAP_ADDR uses the same value as your 2603U-Boot configuration in CFG_IMMR. 2604 2605 2606Configuring the Linux kernel: 2607----------------------------- 2608 2609No specific requirements for U-Boot. Make sure you have some root 2610device (initial ramdisk, NFS) for your target system. 2611 2612 2613Building a Linux Image: 2614----------------------- 2615 2616With U-Boot, "normal" build targets like "zImage" or "bzImage" are 2617not used. If you use recent kernel source, a new build target 2618"uImage" will exist which automatically builds an image usable by 2619U-Boot. Most older kernels also have support for a "pImage" target, 2620which was introduced for our predecessor project PPCBoot and uses a 2621100% compatible format. 2622 2623Example: 2624 2625 make TQM850L_config 2626 make oldconfig 2627 make dep 2628 make uImage 2629 2630The "uImage" build target uses a special tool (in 'tools/mkimage') to 2631encapsulate a compressed Linux kernel image with header information, 2632CRC32 checksum etc. for use with U-Boot. This is what we are doing: 2633 2634* build a standard "vmlinux" kernel image (in ELF binary format): 2635 2636* convert the kernel into a raw binary image: 2637 2638 ${CROSS_COMPILE}-objcopy -O binary \ 2639 -R .note -R .comment \ 2640 -S vmlinux linux.bin 2641 2642* compress the binary image: 2643 2644 gzip -9 linux.bin 2645 2646* package compressed binary image for U-Boot: 2647 2648 mkimage -A ppc -O linux -T kernel -C gzip \ 2649 -a 0 -e 0 -n "Linux Kernel Image" \ 2650 -d linux.bin.gz uImage 2651 2652 2653The "mkimage" tool can also be used to create ramdisk images for use 2654with U-Boot, either separated from the Linux kernel image, or 2655combined into one file. "mkimage" encapsulates the images with a 64 2656byte header containing information about target architecture, 2657operating system, image type, compression method, entry points, time 2658stamp, CRC32 checksums, etc. 2659 2660"mkimage" can be called in two ways: to verify existing images and 2661print the header information, or to build new images. 2662 2663In the first form (with "-l" option) mkimage lists the information 2664contained in the header of an existing U-Boot image; this includes 2665checksum verification: 2666 2667 tools/mkimage -l image 2668 -l ==> list image header information 2669 2670The second form (with "-d" option) is used to build a U-Boot image 2671from a "data file" which is used as image payload: 2672 2673 tools/mkimage -A arch -O os -T type -C comp -a addr -e ep \ 2674 -n name -d data_file image 2675 -A ==> set architecture to 'arch' 2676 -O ==> set operating system to 'os' 2677 -T ==> set image type to 'type' 2678 -C ==> set compression type 'comp' 2679 -a ==> set load address to 'addr' (hex) 2680 -e ==> set entry point to 'ep' (hex) 2681 -n ==> set image name to 'name' 2682 -d ==> use image data from 'datafile' 2683 2684Right now, all Linux kernels for PowerPC systems use the same load 2685address (0x00000000), but the entry point address depends on the 2686kernel version: 2687 2688- 2.2.x kernels have the entry point at 0x0000000C, 2689- 2.3.x and later kernels have the entry point at 0x00000000. 2690 2691So a typical call to build a U-Boot image would read: 2692 2693 -> tools/mkimage -n '2.4.4 kernel for TQM850L' \ 2694 > -A ppc -O linux -T kernel -C gzip -a 0 -e 0 \ 2695 > -d /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/ppc/coffboot/vmlinux.gz \ 2696 > examples/uImage.TQM850L 2697 Image Name: 2.4.4 kernel for TQM850L 2698 Created: Wed Jul 19 02:34:59 2000 2699 Image Type: PowerPC Linux Kernel Image (gzip compressed) 2700 Data Size: 335725 Bytes = 327.86 kB = 0.32 MB 2701 Load Address: 0x00000000 2702 Entry Point: 0x00000000 2703 2704To verify the contents of the image (or check for corruption): 2705 2706 -> tools/mkimage -l examples/uImage.TQM850L 2707 Image Name: 2.4.4 kernel for TQM850L 2708 Created: Wed Jul 19 02:34:59 2000 2709 Image Type: PowerPC Linux Kernel Image (gzip compressed) 2710 Data Size: 335725 Bytes = 327.86 kB = 0.32 MB 2711 Load Address: 0x00000000 2712 Entry Point: 0x00000000 2713 2714NOTE: for embedded systems where boot time is critical you can trade 2715speed for memory and install an UNCOMPRESSED image instead: this 2716needs more space in Flash, but boots much faster since it does not 2717need to be uncompressed: 2718 2719 -> gunzip /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/ppc/coffboot/vmlinux.gz 2720 -> tools/mkimage -n '2.4.4 kernel for TQM850L' \ 2721 > -A ppc -O linux -T kernel -C none -a 0 -e 0 \ 2722 > -d /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/ppc/coffboot/vmlinux \ 2723 > examples/uImage.TQM850L-uncompressed 2724 Image Name: 2.4.4 kernel for TQM850L 2725 Created: Wed Jul 19 02:34:59 2000 2726 Image Type: PowerPC Linux Kernel Image (uncompressed) 2727 Data Size: 792160 Bytes = 773.59 kB = 0.76 MB 2728 Load Address: 0x00000000 2729 Entry Point: 0x00000000 2730 2731 2732Similar you can build U-Boot images from a 'ramdisk.image.gz' file 2733when your kernel is intended to use an initial ramdisk: 2734 2735 -> tools/mkimage -n 'Simple Ramdisk Image' \ 2736 > -A ppc -O linux -T ramdisk -C gzip \ 2737 > -d /LinuxPPC/images/SIMPLE-ramdisk.image.gz examples/simple-initrd 2738 Image Name: Simple Ramdisk Image 2739 Created: Wed Jan 12 14:01:50 2000 2740 Image Type: PowerPC Linux RAMDisk Image (gzip compressed) 2741 Data Size: 566530 Bytes = 553.25 kB = 0.54 MB 2742 Load Address: 0x00000000 2743 Entry Point: 0x00000000 2744 2745 2746Installing a Linux Image: 2747------------------------- 2748 2749To downloading a U-Boot image over the serial (console) interface, 2750you must convert the image to S-Record format: 2751 2752 objcopy -I binary -O srec examples/image examples/image.srec 2753 2754The 'objcopy' does not understand the information in the U-Boot 2755image header, so the resulting S-Record file will be relative to 2756address 0x00000000. To load it to a given address, you need to 2757specify the target address as 'offset' parameter with the 'loads' 2758command. 2759 2760Example: install the image to address 0x40100000 (which on the 2761TQM8xxL is in the first Flash bank): 2762 2763 => erase 40100000 401FFFFF 2764 2765 .......... done 2766 Erased 8 sectors 2767 2768 => loads 40100000 2769 ## Ready for S-Record download ... 2770 ~>examples/image.srec 2771 1 2 3 4 5 6 7 8 9 10 11 12 13 ... 2772 ... 2773 15989 15990 15991 15992 2774 [file transfer complete] 2775 [connected] 2776 ## Start Addr = 0x00000000 2777 2778 2779You can check the success of the download using the 'iminfo' command; 2780this includes a checksum verification so you can be sure no data 2781corruption happened: 2782 2783 => imi 40100000 2784 2785 ## Checking Image at 40100000 ... 2786 Image Name: 2.2.13 for initrd on TQM850L 2787 Image Type: PowerPC Linux Kernel Image (gzip compressed) 2788 Data Size: 335725 Bytes = 327 kB = 0 MB 2789 Load Address: 00000000 2790 Entry Point: 0000000c 2791 Verifying Checksum ... OK 2792 2793 2794Boot Linux: 2795----------- 2796 2797The "bootm" command is used to boot an application that is stored in 2798memory (RAM or Flash). In case of a Linux kernel image, the contents 2799of the "bootargs" environment variable is passed to the kernel as 2800parameters. You can check and modify this variable using the 2801"printenv" and "setenv" commands: 2802 2803 2804 => printenv bootargs 2805 bootargs=root=/dev/ram 2806 2807 => setenv bootargs root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2 2808 2809 => printenv bootargs 2810 bootargs=root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2 2811 2812 => bootm 40020000 2813 ## Booting Linux kernel at 40020000 ... 2814 Image Name: 2.2.13 for NFS on TQM850L 2815 Image Type: PowerPC Linux Kernel Image (gzip compressed) 2816 Data Size: 381681 Bytes = 372 kB = 0 MB 2817 Load Address: 00000000 2818 Entry Point: 0000000c 2819 Verifying Checksum ... OK 2820 Uncompressing Kernel Image ... OK 2821 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 2822 Boot arguments: root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2 2823 time_init: decrementer frequency = 187500000/60 2824 Calibrating delay loop... 49.77 BogoMIPS 2825 Memory: 15208k available (700k kernel code, 444k data, 32k init) [c0000000,c1000000] 2826 ... 2827 2828If you want to boot a Linux kernel with initial ram disk, you pass 2829the memory addresses of both the kernel and the initrd image (PPBCOOT 2830format!) to the "bootm" command: 2831 2832 => imi 40100000 40200000 2833 2834 ## Checking Image at 40100000 ... 2835 Image Name: 2.2.13 for initrd on TQM850L 2836 Image Type: PowerPC Linux Kernel Image (gzip compressed) 2837 Data Size: 335725 Bytes = 327 kB = 0 MB 2838 Load Address: 00000000 2839 Entry Point: 0000000c 2840 Verifying Checksum ... OK 2841 2842 ## Checking Image at 40200000 ... 2843 Image Name: Simple Ramdisk Image 2844 Image Type: PowerPC Linux RAMDisk Image (gzip compressed) 2845 Data Size: 566530 Bytes = 553 kB = 0 MB 2846 Load Address: 00000000 2847 Entry Point: 00000000 2848 Verifying Checksum ... OK 2849 2850 => bootm 40100000 40200000 2851 ## Booting Linux kernel at 40100000 ... 2852 Image Name: 2.2.13 for initrd on TQM850L 2853 Image Type: PowerPC Linux Kernel Image (gzip compressed) 2854 Data Size: 335725 Bytes = 327 kB = 0 MB 2855 Load Address: 00000000 2856 Entry Point: 0000000c 2857 Verifying Checksum ... OK 2858 Uncompressing Kernel Image ... OK 2859 ## Loading RAMDisk Image at 40200000 ... 2860 Image Name: Simple Ramdisk Image 2861 Image Type: PowerPC Linux RAMDisk Image (gzip compressed) 2862 Data Size: 566530 Bytes = 553 kB = 0 MB 2863 Load Address: 00000000 2864 Entry Point: 00000000 2865 Verifying Checksum ... OK 2866 Loading Ramdisk ... OK 2867 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 2868 Boot arguments: root=/dev/ram 2869 time_init: decrementer frequency = 187500000/60 2870 Calibrating delay loop... 49.77 BogoMIPS 2871 ... 2872 RAMDISK: Compressed image found at block 0 2873 VFS: Mounted root (ext2 filesystem). 2874 2875 bash# 2876 2877More About U-Boot Image Types: 2878------------------------------ 2879 2880U-Boot supports the following image types: 2881 2882 "Standalone Programs" are directly runnable in the environment 2883 provided by U-Boot; it is expected that (if they behave 2884 well) you can continue to work in U-Boot after return from 2885 the Standalone Program. 2886 "OS Kernel Images" are usually images of some Embedded OS which 2887 will take over control completely. Usually these programs 2888 will install their own set of exception handlers, device 2889 drivers, set up the MMU, etc. - this means, that you cannot 2890 expect to re-enter U-Boot except by resetting the CPU. 2891 "RAMDisk Images" are more or less just data blocks, and their 2892 parameters (address, size) are passed to an OS kernel that is 2893 being started. 2894 "Multi-File Images" contain several images, typically an OS 2895 (Linux) kernel image and one or more data images like 2896 RAMDisks. This construct is useful for instance when you want 2897 to boot over the network using BOOTP etc., where the boot 2898 server provides just a single image file, but you want to get 2899 for instance an OS kernel and a RAMDisk image. 2900 2901 "Multi-File Images" start with a list of image sizes, each 2902 image size (in bytes) specified by an "uint32_t" in network 2903 byte order. This list is terminated by an "(uint32_t)0". 2904 Immediately after the terminating 0 follow the images, one by 2905 one, all aligned on "uint32_t" boundaries (size rounded up to 2906 a multiple of 4 bytes). 2907 2908 "Firmware Images" are binary images containing firmware (like 2909 U-Boot or FPGA images) which usually will be programmed to 2910 flash memory. 2911 2912 "Script files" are command sequences that will be executed by 2913 U-Boot's command interpreter; this feature is especially 2914 useful when you configure U-Boot to use a real shell (hush) 2915 as command interpreter. 2916 2917 2918Standalone HOWTO: 2919================= 2920 2921One of the features of U-Boot is that you can dynamically load and 2922run "standalone" applications, which can use some resources of 2923U-Boot like console I/O functions or interrupt services. 2924 2925Two simple examples are included with the sources: 2926 2927"Hello World" Demo: 2928------------------- 2929 2930'examples/hello_world.c' contains a small "Hello World" Demo 2931application; it is automatically compiled when you build U-Boot. 2932It's configured to run at address 0x00040004, so you can play with it 2933like that: 2934 2935 => loads 2936 ## Ready for S-Record download ... 2937 ~>examples/hello_world.srec 2938 1 2 3 4 5 6 7 8 9 10 11 ... 2939 [file transfer complete] 2940 [connected] 2941 ## Start Addr = 0x00040004 2942 2943 => go 40004 Hello World! This is a test. 2944 ## Starting application at 0x00040004 ... 2945 Hello World 2946 argc = 7 2947 argv[0] = "40004" 2948 argv[1] = "Hello" 2949 argv[2] = "World!" 2950 argv[3] = "This" 2951 argv[4] = "is" 2952 argv[5] = "a" 2953 argv[6] = "test." 2954 argv[7] = "<NULL>" 2955 Hit any key to exit ... 2956 2957 ## Application terminated, rc = 0x0 2958 2959Another example, which demonstrates how to register a CPM interrupt 2960handler with the U-Boot code, can be found in 'examples/timer.c'. 2961Here, a CPM timer is set up to generate an interrupt every second. 2962The interrupt service routine is trivial, just printing a '.' 2963character, but this is just a demo program. The application can be 2964controlled by the following keys: 2965 2966 ? - print current values og the CPM Timer registers 2967 b - enable interrupts and start timer 2968 e - stop timer and disable interrupts 2969 q - quit application 2970 2971 => loads 2972 ## Ready for S-Record download ... 2973 ~>examples/timer.srec 2974 1 2 3 4 5 6 7 8 9 10 11 ... 2975 [file transfer complete] 2976 [connected] 2977 ## Start Addr = 0x00040004 2978 2979 => go 40004 2980 ## Starting application at 0x00040004 ... 2981 TIMERS=0xfff00980 2982 Using timer 1 2983 tgcr @ 0xfff00980, tmr @ 0xfff00990, trr @ 0xfff00994, tcr @ 0xfff00998, tcn @ 0xfff0099c, ter @ 0xfff009b0 2984 2985Hit 'b': 2986 [q, b, e, ?] Set interval 1000000 us 2987 Enabling timer 2988Hit '?': 2989 [q, b, e, ?] ........ 2990 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0xef6, ter=0x0 2991Hit '?': 2992 [q, b, e, ?] . 2993 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x2ad4, ter=0x0 2994Hit '?': 2995 [q, b, e, ?] . 2996 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x1efc, ter=0x0 2997Hit '?': 2998 [q, b, e, ?] . 2999 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x169d, ter=0x0 3000Hit 'e': 3001 [q, b, e, ?] ...Stopping timer 3002Hit 'q': 3003 [q, b, e, ?] ## Application terminated, rc = 0x0 3004 3005 3006Minicom warning: 3007================ 3008 3009Over time, many people have reported problems when trying to use the 3010"minicom" terminal emulation program for serial download. I (wd) 3011consider minicom to be broken, and recommend not to use it. Under 3012Unix, I recommend to use C-Kermit for general purpose use (and 3013especially for kermit binary protocol download ("loadb" command), and 3014use "cu" for S-Record download ("loads" command). 3015 3016Nevertheless, if you absolutely want to use it try adding this 3017configuration to your "File transfer protocols" section: 3018 3019 Name Program Name U/D FullScr IO-Red. Multi 3020 X kermit /usr/bin/kermit -i -l %l -s Y U Y N N 3021 Y kermit /usr/bin/kermit -i -l %l -r N D Y N N 3022 3023 3024NetBSD Notes: 3025============= 3026 3027Starting at version 0.9.2, U-Boot supports NetBSD both as host 3028(build U-Boot) and target system (boots NetBSD/mpc8xx). 3029 3030Building requires a cross environment; it is known to work on 3031NetBSD/i386 with the cross-powerpc-netbsd-1.3 package (you will also 3032need gmake since the Makefiles are not compatible with BSD make). 3033Note that the cross-powerpc package does not install include files; 3034attempting to build U-Boot will fail because <machine/ansi.h> is 3035missing. This file has to be installed and patched manually: 3036 3037 # cd /usr/pkg/cross/powerpc-netbsd/include 3038 # mkdir powerpc 3039 # ln -s powerpc machine 3040 # cp /usr/src/sys/arch/powerpc/include/ansi.h powerpc/ansi.h 3041 # ${EDIT} powerpc/ansi.h ## must remove __va_list, _BSD_VA_LIST 3042 3043Native builds *don't* work due to incompatibilities between native 3044and U-Boot include files. 3045 3046Booting assumes that (the first part of) the image booted is a 3047stage-2 loader which in turn loads and then invokes the kernel 3048proper. Loader sources will eventually appear in the NetBSD source 3049tree (probably in sys/arc/mpc8xx/stand/u-boot_stage2/); in the 3050meantime, send mail to bruno@exet-ag.de and/or wd@denx.de for 3051details. 3052 3053 3054Implementation Internals: 3055========================= 3056 3057The following is not intended to be a complete description of every 3058implementation detail. However, it should help to understand the 3059inner workings of U-Boot and make it easier to port it to custom 3060hardware. 3061 3062 3063Initial Stack, Global Data: 3064--------------------------- 3065 3066The implementation of U-Boot is complicated by the fact that U-Boot 3067starts running out of ROM (flash memory), usually without access to 3068system RAM (because the memory controller is not initialized yet). 3069This means that we don't have writable Data or BSS segments, and BSS 3070is not initialized as zero. To be able to get a C environment working 3071at all, we have to allocate at least a minimal stack. Implementation 3072options for this are defined and restricted by the CPU used: Some CPU 3073models provide on-chip memory (like the IMMR area on MPC8xx and 3074MPC826x processors), on others (parts of) the data cache can be 3075locked as (mis-) used as memory, etc. 3076 3077 Chris Hallinan posted a good summary of these issues to the 3078 u-boot-users mailing list: 3079 3080 Subject: RE: [U-Boot-Users] RE: More On Memory Bank x (nothingness)? 3081 From: "Chris Hallinan" <clh@net1plus.com> 3082 Date: Mon, 10 Feb 2003 16:43:46 -0500 (22:43 MET) 3083 ... 3084 3085 Correct me if I'm wrong, folks, but the way I understand it 3086 is this: Using DCACHE as initial RAM for Stack, etc, does not 3087 require any physical RAM backing up the cache. The cleverness 3088 is that the cache is being used as a temporary supply of 3089 necessary storage before the SDRAM controller is setup. It's 3090 beyond the scope of this list to expain the details, but you 3091 can see how this works by studying the cache architecture and 3092 operation in the architecture and processor-specific manuals. 3093 3094 OCM is On Chip Memory, which I believe the 405GP has 4K. It 3095 is another option for the system designer to use as an 3096 initial stack/ram area prior to SDRAM being available. Either 3097 option should work for you. Using CS 4 should be fine if your 3098 board designers haven't used it for something that would 3099 cause you grief during the initial boot! It is frequently not 3100 used. 3101 3102 CFG_INIT_RAM_ADDR should be somewhere that won't interfere 3103 with your processor/board/system design. The default value 3104 you will find in any recent u-boot distribution in 3105 Walnut405.h should work for you. I'd set it to a value larger 3106 than your SDRAM module. If you have a 64MB SDRAM module, set 3107 it above 400_0000. Just make sure your board has no resources 3108 that are supposed to respond to that address! That code in 3109 start.S has been around a while and should work as is when 3110 you get the config right. 3111 3112 -Chris Hallinan 3113 DS4.COM, Inc. 3114 3115It is essential to remember this, since it has some impact on the C 3116code for the initialization procedures: 3117 3118* Initialized global data (data segment) is read-only. Do not attempt 3119 to write it. 3120 3121* Do not use any unitialized global data (or implicitely initialized 3122 as zero data - BSS segment) at all - this is undefined, initiali- 3123 zation is performed later (when relocating to RAM). 3124 3125* Stack space is very limited. Avoid big data buffers or things like 3126 that. 3127 3128Having only the stack as writable memory limits means we cannot use 3129normal global data to share information beween the code. But it 3130turned out that the implementation of U-Boot can be greatly 3131simplified by making a global data structure (gd_t) available to all 3132functions. We could pass a pointer to this data as argument to _all_ 3133functions, but this would bloat the code. Instead we use a feature of 3134the GCC compiler (Global Register Variables) to share the data: we 3135place a pointer (gd) to the global data into a register which we 3136reserve for this purpose. 3137 3138When choosing a register for such a purpose we are restricted by the 3139relevant (E)ABI specifications for the current architecture, and by 3140GCC's implementation. 3141 3142For PowerPC, the following registers have specific use: 3143 R1: stack pointer 3144 R2: TOC pointer 3145 R3-R4: parameter passing and return values 3146 R5-R10: parameter passing 3147 R13: small data area pointer 3148 R30: GOT pointer 3149 R31: frame pointer 3150 3151 (U-Boot also uses R14 as internal GOT pointer.) 3152 3153 ==> U-Boot will use R29 to hold a pointer to the global data 3154 3155 Note: on PPC, we could use a static initializer (since the 3156 address of the global data structure is known at compile time), 3157 but it turned out that reserving a register results in somewhat 3158 smaller code - although the code savings are not that big (on 3159 average for all boards 752 bytes for the whole U-Boot image, 3160 624 text + 127 data). 3161 3162On ARM, the following registers are used: 3163 3164 R0: function argument word/integer result 3165 R1-R3: function argument word 3166 R9: GOT pointer 3167 R10: stack limit (used only if stack checking if enabled) 3168 R11: argument (frame) pointer 3169 R12: temporary workspace 3170 R13: stack pointer 3171 R14: link register 3172 R15: program counter 3173 3174 ==> U-Boot will use R8 to hold a pointer to the global data 3175 3176 3177Memory Management: 3178------------------ 3179 3180U-Boot runs in system state and uses physical addresses, i.e. the 3181MMU is not used either for address mapping nor for memory protection. 3182 3183The available memory is mapped to fixed addresses using the memory 3184controller. In this process, a contiguous block is formed for each 3185memory type (Flash, SDRAM, SRAM), even when it consists of several 3186physical memory banks. 3187 3188U-Boot is installed in the first 128 kB of the first Flash bank (on 3189TQM8xxL modules this is the range 0x40000000 ... 0x4001FFFF). After 3190booting and sizing and initializing DRAM, the code relocates itself 3191to the upper end of DRAM. Immediately below the U-Boot code some 3192memory is reserved for use by malloc() [see CFG_MALLOC_LEN 3193configuration setting]. Below that, a structure with global Board 3194Info data is placed, followed by the stack (growing downward). 3195 3196Additionally, some exception handler code is copied to the low 8 kB 3197of DRAM (0x00000000 ... 0x00001FFF). 3198 3199So a typical memory configuration with 16 MB of DRAM could look like 3200this: 3201 3202 0x0000 0000 Exception Vector code 3203 : 3204 0x0000 1FFF 3205 0x0000 2000 Free for Application Use 3206 : 3207 : 3208 3209 : 3210 : 3211 0x00FB FF20 Monitor Stack (Growing downward) 3212 0x00FB FFAC Board Info Data and permanent copy of global data 3213 0x00FC 0000 Malloc Arena 3214 : 3215 0x00FD FFFF 3216 0x00FE 0000 RAM Copy of Monitor Code 3217 ... eventually: LCD or video framebuffer 3218 ... eventually: pRAM (Protected RAM - unchanged by reset) 3219 0x00FF FFFF [End of RAM] 3220 3221 3222System Initialization: 3223---------------------- 3224 3225In the reset configuration, U-Boot starts at the reset entry point 3226(on most PowerPC systens at address 0x00000100). Because of the reset 3227configuration for CS0# this is a mirror of the onboard Flash memory. 3228To be able to re-map memory U-Boot then jumps to its link address. 3229To be able to implement the initialization code in C, a (small!) 3230initial stack is set up in the internal Dual Ported RAM (in case CPUs 3231which provide such a feature like MPC8xx or MPC8260), or in a locked 3232part of the data cache. After that, U-Boot initializes the CPU core, 3233the caches and the SIU. 3234 3235Next, all (potentially) available memory banks are mapped using a 3236preliminary mapping. For example, we put them on 512 MB boundaries 3237(multiples of 0x20000000: SDRAM on 0x00000000 and 0x20000000, Flash 3238on 0x40000000 and 0x60000000, SRAM on 0x80000000). Then UPM A is 3239programmed for SDRAM access. Using the temporary configuration, a 3240simple memory test is run that determines the size of the SDRAM 3241banks. 3242 3243When there is more than one SDRAM bank, and the banks are of 3244different size, the largest is mapped first. For equal size, the first 3245bank (CS2#) is mapped first. The first mapping is always for address 32460x00000000, with any additional banks following immediately to create 3247contiguous memory starting from 0. 3248 3249Then, the monitor installs itself at the upper end of the SDRAM area 3250and allocates memory for use by malloc() and for the global Board 3251Info data; also, the exception vector code is copied to the low RAM 3252pages, and the final stack is set up. 3253 3254Only after this relocation will you have a "normal" C environment; 3255until that you are restricted in several ways, mostly because you are 3256running from ROM, and because the code will have to be relocated to a 3257new address in RAM. 3258 3259 3260U-Boot Porting Guide: 3261---------------------- 3262 3263[Based on messages by Jerry Van Baren in the U-Boot-Users mailing 3264list, October 2002] 3265 3266 3267int main (int argc, char *argv[]) 3268{ 3269 sighandler_t no_more_time; 3270 3271 signal (SIGALRM, no_more_time); 3272 alarm (PROJECT_DEADLINE - toSec (3 * WEEK)); 3273 3274 if (available_money > available_manpower) { 3275 pay consultant to port U-Boot; 3276 return 0; 3277 } 3278 3279 Download latest U-Boot source; 3280 3281 Subscribe to u-boot-users mailing list; 3282 3283 if (clueless) { 3284 email ("Hi, I am new to U-Boot, how do I get started?"); 3285 } 3286 3287 while (learning) { 3288 Read the README file in the top level directory; 3289 Read http://www.denx.de/twiki/bin/view/DULG/Manual ; 3290 Read the source, Luke; 3291 } 3292 3293 if (available_money > toLocalCurrency ($2500)) { 3294 Buy a BDI2000; 3295 } else { 3296 Add a lot of aggravation and time; 3297 } 3298 3299 Create your own board support subdirectory; 3300 3301 Create your own board config file; 3302 3303 while (!running) { 3304 do { 3305 Add / modify source code; 3306 } until (compiles); 3307 Debug; 3308 if (clueless) 3309 email ("Hi, I am having problems..."); 3310 } 3311 Send patch file to Wolfgang; 3312 3313 return 0; 3314} 3315 3316void no_more_time (int sig) 3317{ 3318 hire_a_guru(); 3319} 3320 3321 3322Coding Standards: 3323----------------- 3324 3325All contributions to U-Boot should conform to the Linux kernel 3326coding style; see the file "Documentation/CodingStyle" in your Linux 3327kernel source directory. 3328 3329Please note that U-Boot is implemented in C (and to some small parts 3330in Assembler); no C++ is used, so please do not use C++ style 3331comments (//) in your code. 3332 3333Please also stick to the following formatting rules: 3334- remove any trailing white space 3335- use TAB characters for indentation, not spaces 3336- make sure NOT to use DOS '\r\n' line feeds 3337- do not add more than 2 empty lines to source files 3338- do not add trailing empty lines to source files 3339 3340Submissions which do not conform to the standards may be returned 3341with a request to reformat the changes. 3342 3343 3344Submitting Patches: 3345------------------- 3346 3347Since the number of patches for U-Boot is growing, we need to 3348establish some rules. Submissions which do not conform to these rules 3349may be rejected, even when they contain important and valuable stuff. 3350 3351 3352When you send a patch, please include the following information with 3353it: 3354 3355* For bug fixes: a description of the bug and how your patch fixes 3356 this bug. Please try to include a way of demonstrating that the 3357 patch actually fixes something. 3358 3359* For new features: a description of the feature and your 3360 implementation. 3361 3362* A CHANGELOG entry as plaintext (separate from the patch) 3363 3364* For major contributions, your entry to the CREDITS file 3365 3366* When you add support for a new board, don't forget to add this 3367 board to the MAKEALL script, too. 3368 3369* If your patch adds new configuration options, don't forget to 3370 document these in the README file. 3371 3372* The patch itself. If you are accessing the CVS repository use "cvs 3373 update; cvs diff -puRN"; else, use "diff -purN OLD NEW". If your 3374 version of diff does not support these options, then get the latest 3375 version of GNU diff. 3376 3377 The current directory when running this command shall be the top 3378 level directory of the U-Boot source tree, or it's parent directory 3379 (i. e. please make sure that your patch includes sufficient 3380 directory information for the affected files). 3381 3382 We accept patches as plain text, MIME attachments or as uuencoded 3383 gzipped text. 3384 3385* If one logical set of modifications affects or creates several 3386 files, all these changes shall be submitted in a SINGLE patch file. 3387 3388* Changesets that contain different, unrelated modifications shall be 3389 submitted as SEPARATE patches, one patch per changeset. 3390 3391 3392Notes: 3393 3394* Before sending the patch, run the MAKEALL script on your patched 3395 source tree and make sure that no errors or warnings are reported 3396 for any of the boards. 3397 3398* Keep your modifications to the necessary minimum: A patch 3399 containing several unrelated changes or arbitrary reformats will be 3400 returned with a request to re-formatting / split it. 3401 3402* If you modify existing code, make sure that your new code does not 3403 add to the memory footprint of the code ;-) Small is beautiful! 3404 When adding new features, these should compile conditionally only 3405 (using #ifdef), and the resulting code with the new feature 3406 disabled must not need more memory than the old code without your 3407 modification. 3408