1# 2# (C) Copyright 2000 - 2008 3# Wolfgang Denk, DENX Software Engineering, wd@denx.de. 4# 5# See file CREDITS for list of people who contributed to this 6# project. 7# 8# This program is free software; you can redistribute it and/or 9# modify it under the terms of the GNU General Public License as 10# published by the Free Software Foundation; either version 2 of 11# the License, or (at your option) any later version. 12# 13# This program is distributed in the hope that it will be useful, 14# but WITHOUT ANY WARRANTY; without even the implied warranty of 15# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 16# GNU General Public License for more details. 17# 18# You should have received a copy of the GNU General Public License 19# along with this program; if not, write to the Free Software 20# Foundation, Inc., 59 Temple Place, Suite 330, Boston, 21# MA 02111-1307 USA 22# 23 24Summary: 25======== 26 27This directory contains the source code for U-Boot, a boot loader for 28Embedded boards based on PowerPC, ARM, MIPS and several other 29processors, which can be installed in a boot ROM and used to 30initialize and test the hardware or to download and run application 31code. 32 33The development of U-Boot is closely related to Linux: some parts of 34the source code originate in the Linux source tree, we have some 35header files in common, and special provision has been made to 36support booting of Linux images. 37 38Some attention has been paid to make this software easily 39configurable and extendable. For instance, all monitor commands are 40implemented with the same call interface, so that it's very easy to 41add new commands. Also, instead of permanently adding rarely used 42code (for instance hardware test utilities) to the monitor, you can 43load and run it dynamically. 44 45 46Status: 47======= 48 49In general, all boards for which a configuration option exists in the 50Makefile have been tested to some extent and can be considered 51"working". In fact, many of them are used in production systems. 52 53In case of problems see the CHANGELOG and CREDITS files to find out 54who contributed the specific port. The MAINTAINERS file lists board 55maintainers. 56 57 58Where to get help: 59================== 60 61In case you have questions about, problems with or contributions for 62U-Boot you should send a message to the U-Boot mailing list at 63<u-boot@lists.denx.de>. There is also an archive of previous traffic 64on the mailing list - please search the archive before asking FAQ's. 65Please see http://lists.denx.de/pipermail/u-boot and 66http://dir.gmane.org/gmane.comp.boot-loaders.u-boot 67 68 69Where to get source code: 70========================= 71 72The U-Boot source code is maintained in the git repository at 73git://www.denx.de/git/u-boot.git ; you can browse it online at 74http://www.denx.de/cgi-bin/gitweb.cgi?p=u-boot.git;a=summary 75 76The "snapshot" links on this page allow you to download tarballs of 77any version you might be interested in. Official releases are also 78available for FTP download from the ftp://ftp.denx.de/pub/u-boot/ 79directory. 80 81Pre-built (and tested) images are available from 82ftp://ftp.denx.de/pub/u-boot/images/ 83 84 85Where we come from: 86=================== 87 88- start from 8xxrom sources 89- create PPCBoot project (http://sourceforge.net/projects/ppcboot) 90- clean up code 91- make it easier to add custom boards 92- make it possible to add other [PowerPC] CPUs 93- extend functions, especially: 94 * Provide extended interface to Linux boot loader 95 * S-Record download 96 * network boot 97 * PCMCIA / CompactFlash / ATA disk / SCSI ... boot 98- create ARMBoot project (http://sourceforge.net/projects/armboot) 99- add other CPU families (starting with ARM) 100- create U-Boot project (http://sourceforge.net/projects/u-boot) 101- current project page: see http://www.denx.de/wiki/U-Boot 102 103 104Names and Spelling: 105=================== 106 107The "official" name of this project is "Das U-Boot". The spelling 108"U-Boot" shall be used in all written text (documentation, comments 109in source files etc.). Example: 110 111 This is the README file for the U-Boot project. 112 113File names etc. shall be based on the string "u-boot". Examples: 114 115 include/asm-ppc/u-boot.h 116 117 #include <asm/u-boot.h> 118 119Variable names, preprocessor constants etc. shall be either based on 120the string "u_boot" or on "U_BOOT". Example: 121 122 U_BOOT_VERSION u_boot_logo 123 IH_OS_U_BOOT u_boot_hush_start 124 125 126Versioning: 127=========== 128 129U-Boot uses a 3 level version number containing a version, a 130sub-version, and a patchlevel: "U-Boot-2.34.5" means version "2", 131sub-version "34", and patchlevel "4". 132 133The patchlevel is used to indicate certain stages of development 134between released versions, i. e. officially released versions of 135U-Boot will always have a patchlevel of "0". 136 137 138Directory Hierarchy: 139==================== 140 141- board Board dependent files 142- common Misc architecture independent functions 143- cpu CPU specific files 144 - 74xx_7xx Files specific to Freescale MPC74xx and 7xx CPUs 145 - arm720t Files specific to ARM 720 CPUs 146 - arm920t Files specific to ARM 920 CPUs 147 - at91rm9200 Files specific to Atmel AT91RM9200 CPU 148 - imx Files specific to Freescale MC9328 i.MX CPUs 149 - s3c24x0 Files specific to Samsung S3C24X0 CPUs 150 - arm925t Files specific to ARM 925 CPUs 151 - arm926ejs Files specific to ARM 926 CPUs 152 - arm1136 Files specific to ARM 1136 CPUs 153 - at32ap Files specific to Atmel AVR32 AP CPUs 154 - i386 Files specific to i386 CPUs 155 - ixp Files specific to Intel XScale IXP CPUs 156 - leon2 Files specific to Gaisler LEON2 SPARC CPU 157 - leon3 Files specific to Gaisler LEON3 SPARC CPU 158 - mcf52x2 Files specific to Freescale ColdFire MCF52x2 CPUs 159 - mcf5227x Files specific to Freescale ColdFire MCF5227x CPUs 160 - mcf532x Files specific to Freescale ColdFire MCF5329 CPUs 161 - mcf5445x Files specific to Freescale ColdFire MCF5445x CPUs 162 - mcf547x_8x Files specific to Freescale ColdFire MCF547x_8x CPUs 163 - mips Files specific to MIPS CPUs 164 - mpc5xx Files specific to Freescale MPC5xx CPUs 165 - mpc5xxx Files specific to Freescale MPC5xxx CPUs 166 - mpc8xx Files specific to Freescale MPC8xx CPUs 167 - mpc8220 Files specific to Freescale MPC8220 CPUs 168 - mpc824x Files specific to Freescale MPC824x CPUs 169 - mpc8260 Files specific to Freescale MPC8260 CPUs 170 - mpc85xx Files specific to Freescale MPC85xx CPUs 171 - nios Files specific to Altera NIOS CPUs 172 - nios2 Files specific to Altera Nios-II CPUs 173 - ppc4xx Files specific to AMCC PowerPC 4xx CPUs 174 - pxa Files specific to Intel XScale PXA CPUs 175 - s3c44b0 Files specific to Samsung S3C44B0 CPUs 176 - sa1100 Files specific to Intel StrongARM SA1100 CPUs 177- disk Code for disk drive partition handling 178- doc Documentation (don't expect too much) 179- drivers Commonly used device drivers 180- dtt Digital Thermometer and Thermostat drivers 181- examples Example code for standalone applications, etc. 182- include Header Files 183- lib_arm Files generic to ARM architecture 184- lib_avr32 Files generic to AVR32 architecture 185- lib_generic Files generic to all architectures 186- lib_i386 Files generic to i386 architecture 187- lib_m68k Files generic to m68k architecture 188- lib_mips Files generic to MIPS architecture 189- lib_nios Files generic to NIOS architecture 190- lib_ppc Files generic to PowerPC architecture 191- lib_sparc Files generic to SPARC architecture 192- libfdt Library files to support flattened device trees 193- net Networking code 194- post Power On Self Test 195- rtc Real Time Clock drivers 196- tools Tools to build S-Record or U-Boot images, etc. 197 198Software Configuration: 199======================= 200 201Configuration is usually done using C preprocessor defines; the 202rationale behind that is to avoid dead code whenever possible. 203 204There are two classes of configuration variables: 205 206* Configuration _OPTIONS_: 207 These are selectable by the user and have names beginning with 208 "CONFIG_". 209 210* Configuration _SETTINGS_: 211 These depend on the hardware etc. and should not be meddled with if 212 you don't know what you're doing; they have names beginning with 213 "CFG_". 214 215Later we will add a configuration tool - probably similar to or even 216identical to what's used for the Linux kernel. Right now, we have to 217do the configuration by hand, which means creating some symbolic 218links and editing some configuration files. We use the TQM8xxL boards 219as an example here. 220 221 222Selection of Processor Architecture and Board Type: 223--------------------------------------------------- 224 225For all supported boards there are ready-to-use default 226configurations available; just type "make <board_name>_config". 227 228Example: For a TQM823L module type: 229 230 cd u-boot 231 make TQM823L_config 232 233For the Cogent platform, you need to specify the CPU type as well; 234e.g. "make cogent_mpc8xx_config". And also configure the cogent 235directory according to the instructions in cogent/README. 236 237 238Configuration Options: 239---------------------- 240 241Configuration depends on the combination of board and CPU type; all 242such information is kept in a configuration file 243"include/configs/<board_name>.h". 244 245Example: For a TQM823L module, all configuration settings are in 246"include/configs/TQM823L.h". 247 248 249Many of the options are named exactly as the corresponding Linux 250kernel configuration options. The intention is to make it easier to 251build a config tool - later. 252 253 254The following options need to be configured: 255 256- CPU Type: Define exactly one, e.g. CONFIG_MPC85XX. 257 258- Board Type: Define exactly one, e.g. CONFIG_MPC8540ADS. 259 260- CPU Daughterboard Type: (if CONFIG_ATSTK1000 is defined) 261 Define exactly one, e.g. CONFIG_ATSTK1002 262 263- CPU Module Type: (if CONFIG_COGENT is defined) 264 Define exactly one of 265 CONFIG_CMA286_60_OLD 266--- FIXME --- not tested yet: 267 CONFIG_CMA286_60, CONFIG_CMA286_21, CONFIG_CMA286_60P, 268 CONFIG_CMA287_23, CONFIG_CMA287_50 269 270- Motherboard Type: (if CONFIG_COGENT is defined) 271 Define exactly one of 272 CONFIG_CMA101, CONFIG_CMA102 273 274- Motherboard I/O Modules: (if CONFIG_COGENT is defined) 275 Define one or more of 276 CONFIG_CMA302 277 278- Motherboard Options: (if CONFIG_CMA101 or CONFIG_CMA102 are defined) 279 Define one or more of 280 CONFIG_LCD_HEARTBEAT - update a character position on 281 the LCD display every second with 282 a "rotator" |\-/|\-/ 283 284- Board flavour: (if CONFIG_MPC8260ADS is defined) 285 CONFIG_ADSTYPE 286 Possible values are: 287 CFG_8260ADS - original MPC8260ADS 288 CFG_8266ADS - MPC8266ADS 289 CFG_PQ2FADS - PQ2FADS-ZU or PQ2FADS-VR 290 CFG_8272ADS - MPC8272ADS 291 292- MPC824X Family Member (if CONFIG_MPC824X is defined) 293 Define exactly one of 294 CONFIG_MPC8240, CONFIG_MPC8245 295 296- 8xx CPU Options: (if using an MPC8xx CPU) 297 CONFIG_8xx_GCLK_FREQ - deprecated: CPU clock if 298 get_gclk_freq() cannot work 299 e.g. if there is no 32KHz 300 reference PIT/RTC clock 301 CONFIG_8xx_OSCLK - PLL input clock (either EXTCLK 302 or XTAL/EXTAL) 303 304- 859/866/885 CPU options: (if using a MPC859 or MPC866 or MPC885 CPU): 305 CFG_8xx_CPUCLK_MIN 306 CFG_8xx_CPUCLK_MAX 307 CONFIG_8xx_CPUCLK_DEFAULT 308 See doc/README.MPC866 309 310 CFG_MEASURE_CPUCLK 311 312 Define this to measure the actual CPU clock instead 313 of relying on the correctness of the configured 314 values. Mostly useful for board bringup to make sure 315 the PLL is locked at the intended frequency. Note 316 that this requires a (stable) reference clock (32 kHz 317 RTC clock or CFG_8XX_XIN) 318 319- Intel Monahans options: 320 CFG_MONAHANS_RUN_MODE_OSC_RATIO 321 322 Defines the Monahans run mode to oscillator 323 ratio. Valid values are 8, 16, 24, 31. The core 324 frequency is this value multiplied by 13 MHz. 325 326 CFG_MONAHANS_TURBO_RUN_MODE_RATIO 327 328 Defines the Monahans turbo mode to oscillator 329 ratio. Valid values are 1 (default if undefined) and 330 2. The core frequency as calculated above is multiplied 331 by this value. 332 333- Linux Kernel Interface: 334 CONFIG_CLOCKS_IN_MHZ 335 336 U-Boot stores all clock information in Hz 337 internally. For binary compatibility with older Linux 338 kernels (which expect the clocks passed in the 339 bd_info data to be in MHz) the environment variable 340 "clocks_in_mhz" can be defined so that U-Boot 341 converts clock data to MHZ before passing it to the 342 Linux kernel. 343 When CONFIG_CLOCKS_IN_MHZ is defined, a definition of 344 "clocks_in_mhz=1" is automatically included in the 345 default environment. 346 347 CONFIG_MEMSIZE_IN_BYTES [relevant for MIPS only] 348 349 When transferring memsize parameter to linux, some versions 350 expect it to be in bytes, others in MB. 351 Define CONFIG_MEMSIZE_IN_BYTES to make it in bytes. 352 353 CONFIG_OF_LIBFDT 354 355 New kernel versions are expecting firmware settings to be 356 passed using flattened device trees (based on open firmware 357 concepts). 358 359 CONFIG_OF_LIBFDT 360 * New libfdt-based support 361 * Adds the "fdt" command 362 * The bootm command automatically updates the fdt 363 364 OF_CPU - The proper name of the cpus node. 365 OF_SOC - The proper name of the soc node. 366 OF_TBCLK - The timebase frequency. 367 OF_STDOUT_PATH - The path to the console device 368 369 boards with QUICC Engines require OF_QE to set UCC MAC 370 addresses 371 372 CONFIG_OF_BOARD_SETUP 373 374 Board code has addition modification that it wants to make 375 to the flat device tree before handing it off to the kernel 376 377 CONFIG_OF_BOOT_CPU 378 379 This define fills in the correct boot CPU in the boot 380 param header, the default value is zero if undefined. 381 382- Serial Ports: 383 CONFIG_PL010_SERIAL 384 385 Define this if you want support for Amba PrimeCell PL010 UARTs. 386 387 CONFIG_PL011_SERIAL 388 389 Define this if you want support for Amba PrimeCell PL011 UARTs. 390 391 CONFIG_PL011_CLOCK 392 393 If you have Amba PrimeCell PL011 UARTs, set this variable to 394 the clock speed of the UARTs. 395 396 CONFIG_PL01x_PORTS 397 398 If you have Amba PrimeCell PL010 or PL011 UARTs on your board, 399 define this to a list of base addresses for each (supported) 400 port. See e.g. include/configs/versatile.h 401 402 403- Console Interface: 404 Depending on board, define exactly one serial port 405 (like CONFIG_8xx_CONS_SMC1, CONFIG_8xx_CONS_SMC2, 406 CONFIG_8xx_CONS_SCC1, ...), or switch off the serial 407 console by defining CONFIG_8xx_CONS_NONE 408 409 Note: if CONFIG_8xx_CONS_NONE is defined, the serial 410 port routines must be defined elsewhere 411 (i.e. serial_init(), serial_getc(), ...) 412 413 CONFIG_CFB_CONSOLE 414 Enables console device for a color framebuffer. Needs following 415 defines (cf. smiLynxEM, i8042, board/eltec/bab7xx) 416 VIDEO_FB_LITTLE_ENDIAN graphic memory organisation 417 (default big endian) 418 VIDEO_HW_RECTFILL graphic chip supports 419 rectangle fill 420 (cf. smiLynxEM) 421 VIDEO_HW_BITBLT graphic chip supports 422 bit-blit (cf. smiLynxEM) 423 VIDEO_VISIBLE_COLS visible pixel columns 424 (cols=pitch) 425 VIDEO_VISIBLE_ROWS visible pixel rows 426 VIDEO_PIXEL_SIZE bytes per pixel 427 VIDEO_DATA_FORMAT graphic data format 428 (0-5, cf. cfb_console.c) 429 VIDEO_FB_ADRS framebuffer address 430 VIDEO_KBD_INIT_FCT keyboard int fct 431 (i.e. i8042_kbd_init()) 432 VIDEO_TSTC_FCT test char fct 433 (i.e. i8042_tstc) 434 VIDEO_GETC_FCT get char fct 435 (i.e. i8042_getc) 436 CONFIG_CONSOLE_CURSOR cursor drawing on/off 437 (requires blink timer 438 cf. i8042.c) 439 CFG_CONSOLE_BLINK_COUNT blink interval (cf. i8042.c) 440 CONFIG_CONSOLE_TIME display time/date info in 441 upper right corner 442 (requires CONFIG_CMD_DATE) 443 CONFIG_VIDEO_LOGO display Linux logo in 444 upper left corner 445 CONFIG_VIDEO_BMP_LOGO use bmp_logo.h instead of 446 linux_logo.h for logo. 447 Requires CONFIG_VIDEO_LOGO 448 CONFIG_CONSOLE_EXTRA_INFO 449 additional board info beside 450 the logo 451 452 When CONFIG_CFB_CONSOLE is defined, video console is 453 default i/o. Serial console can be forced with 454 environment 'console=serial'. 455 456 When CONFIG_SILENT_CONSOLE is defined, all console 457 messages (by U-Boot and Linux!) can be silenced with 458 the "silent" environment variable. See 459 doc/README.silent for more information. 460 461- Console Baudrate: 462 CONFIG_BAUDRATE - in bps 463 Select one of the baudrates listed in 464 CFG_BAUDRATE_TABLE, see below. 465 CFG_BRGCLK_PRESCALE, baudrate prescale 466 467- Interrupt driven serial port input: 468 CONFIG_SERIAL_SOFTWARE_FIFO 469 470 PPC405GP only. 471 Use an interrupt handler for receiving data on the 472 serial port. It also enables using hardware handshake 473 (RTS/CTS) and UART's built-in FIFO. Set the number of 474 bytes the interrupt driven input buffer should have. 475 476 Leave undefined to disable this feature, including 477 disable the buffer and hardware handshake. 478 479- Console UART Number: 480 CONFIG_UART1_CONSOLE 481 482 AMCC PPC4xx only. 483 If defined internal UART1 (and not UART0) is used 484 as default U-Boot console. 485 486- Boot Delay: CONFIG_BOOTDELAY - in seconds 487 Delay before automatically booting the default image; 488 set to -1 to disable autoboot. 489 490 See doc/README.autoboot for these options that 491 work with CONFIG_BOOTDELAY. None are required. 492 CONFIG_BOOT_RETRY_TIME 493 CONFIG_BOOT_RETRY_MIN 494 CONFIG_AUTOBOOT_KEYED 495 CONFIG_AUTOBOOT_PROMPT 496 CONFIG_AUTOBOOT_DELAY_STR 497 CONFIG_AUTOBOOT_STOP_STR 498 CONFIG_AUTOBOOT_DELAY_STR2 499 CONFIG_AUTOBOOT_STOP_STR2 500 CONFIG_ZERO_BOOTDELAY_CHECK 501 CONFIG_RESET_TO_RETRY 502 503- Autoboot Command: 504 CONFIG_BOOTCOMMAND 505 Only needed when CONFIG_BOOTDELAY is enabled; 506 define a command string that is automatically executed 507 when no character is read on the console interface 508 within "Boot Delay" after reset. 509 510 CONFIG_BOOTARGS 511 This can be used to pass arguments to the bootm 512 command. The value of CONFIG_BOOTARGS goes into the 513 environment value "bootargs". 514 515 CONFIG_RAMBOOT and CONFIG_NFSBOOT 516 The value of these goes into the environment as 517 "ramboot" and "nfsboot" respectively, and can be used 518 as a convenience, when switching between booting from 519 RAM and NFS. 520 521- Pre-Boot Commands: 522 CONFIG_PREBOOT 523 524 When this option is #defined, the existence of the 525 environment variable "preboot" will be checked 526 immediately before starting the CONFIG_BOOTDELAY 527 countdown and/or running the auto-boot command resp. 528 entering interactive mode. 529 530 This feature is especially useful when "preboot" is 531 automatically generated or modified. For an example 532 see the LWMON board specific code: here "preboot" is 533 modified when the user holds down a certain 534 combination of keys on the (special) keyboard when 535 booting the systems 536 537- Serial Download Echo Mode: 538 CONFIG_LOADS_ECHO 539 If defined to 1, all characters received during a 540 serial download (using the "loads" command) are 541 echoed back. This might be needed by some terminal 542 emulations (like "cu"), but may as well just take 543 time on others. This setting #define's the initial 544 value of the "loads_echo" environment variable. 545 546- Kgdb Serial Baudrate: (if CONFIG_CMD_KGDB is defined) 547 CONFIG_KGDB_BAUDRATE 548 Select one of the baudrates listed in 549 CFG_BAUDRATE_TABLE, see below. 550 551- Monitor Functions: 552 Monitor commands can be included or excluded 553 from the build by using the #include files 554 "config_cmd_all.h" and #undef'ing unwanted 555 commands, or using "config_cmd_default.h" 556 and augmenting with additional #define's 557 for wanted commands. 558 559 The default command configuration includes all commands 560 except those marked below with a "*". 561 562 CONFIG_CMD_ASKENV * ask for env variable 563 CONFIG_CMD_AUTOSCRIPT Autoscript Support 564 CONFIG_CMD_BDI bdinfo 565 CONFIG_CMD_BEDBUG * Include BedBug Debugger 566 CONFIG_CMD_BMP * BMP support 567 CONFIG_CMD_BSP * Board specific commands 568 CONFIG_CMD_BOOTD bootd 569 CONFIG_CMD_CACHE * icache, dcache 570 CONFIG_CMD_CONSOLE coninfo 571 CONFIG_CMD_DATE * support for RTC, date/time... 572 CONFIG_CMD_DHCP * DHCP support 573 CONFIG_CMD_DIAG * Diagnostics 574 CONFIG_CMD_DOC * Disk-On-Chip Support 575 CONFIG_CMD_DTT * Digital Therm and Thermostat 576 CONFIG_CMD_ECHO echo arguments 577 CONFIG_CMD_EEPROM * EEPROM read/write support 578 CONFIG_CMD_ELF * bootelf, bootvx 579 CONFIG_CMD_ENV saveenv 580 CONFIG_CMD_FDC * Floppy Disk Support 581 CONFIG_CMD_FAT * FAT partition support 582 CONFIG_CMD_FDOS * Dos diskette Support 583 CONFIG_CMD_FLASH flinfo, erase, protect 584 CONFIG_CMD_FPGA FPGA device initialization support 585 CONFIG_CMD_HWFLOW * RTS/CTS hw flow control 586 CONFIG_CMD_I2C * I2C serial bus support 587 CONFIG_CMD_IDE * IDE harddisk support 588 CONFIG_CMD_IMI iminfo 589 CONFIG_CMD_IMLS List all found images 590 CONFIG_CMD_IMMAP * IMMR dump support 591 CONFIG_CMD_IRQ * irqinfo 592 CONFIG_CMD_ITEST Integer/string test of 2 values 593 CONFIG_CMD_JFFS2 * JFFS2 Support 594 CONFIG_CMD_KGDB * kgdb 595 CONFIG_CMD_LOADB loadb 596 CONFIG_CMD_LOADS loads 597 CONFIG_CMD_MEMORY md, mm, nm, mw, cp, cmp, crc, base, 598 loop, loopw, mtest 599 CONFIG_CMD_MISC Misc functions like sleep etc 600 CONFIG_CMD_MMC * MMC memory mapped support 601 CONFIG_CMD_MII * MII utility commands 602 CONFIG_CMD_NAND * NAND support 603 CONFIG_CMD_NET bootp, tftpboot, rarpboot 604 CONFIG_CMD_PCI * pciinfo 605 CONFIG_CMD_PCMCIA * PCMCIA support 606 CONFIG_CMD_PING * send ICMP ECHO_REQUEST to network 607 host 608 CONFIG_CMD_PORTIO * Port I/O 609 CONFIG_CMD_REGINFO * Register dump 610 CONFIG_CMD_RUN run command in env variable 611 CONFIG_CMD_SAVES * save S record dump 612 CONFIG_CMD_SCSI * SCSI Support 613 CONFIG_CMD_SDRAM * print SDRAM configuration information 614 (requires CONFIG_CMD_I2C) 615 CONFIG_CMD_SETGETDCR Support for DCR Register access 616 (4xx only) 617 CONFIG_CMD_SPI * SPI serial bus support 618 CONFIG_CMD_USB * USB support 619 CONFIG_CMD_VFD * VFD support (TRAB) 620 CONFIG_CMD_CDP * Cisco Discover Protocol support 621 CONFIG_CMD_FSL * Microblaze FSL support 622 623 624 EXAMPLE: If you want all functions except of network 625 support you can write: 626 627 #include "config_cmd_all.h" 628 #undef CONFIG_CMD_NET 629 630 Other Commands: 631 fdt (flattened device tree) command: CONFIG_OF_LIBFDT 632 633 Note: Don't enable the "icache" and "dcache" commands 634 (configuration option CONFIG_CMD_CACHE) unless you know 635 what you (and your U-Boot users) are doing. Data 636 cache cannot be enabled on systems like the 8xx or 637 8260 (where accesses to the IMMR region must be 638 uncached), and it cannot be disabled on all other 639 systems where we (mis-) use the data cache to hold an 640 initial stack and some data. 641 642 643 XXX - this list needs to get updated! 644 645- Watchdog: 646 CONFIG_WATCHDOG 647 If this variable is defined, it enables watchdog 648 support. There must be support in the platform specific 649 code for a watchdog. For the 8xx and 8260 CPUs, the 650 SIU Watchdog feature is enabled in the SYPCR 651 register. 652 653- U-Boot Version: 654 CONFIG_VERSION_VARIABLE 655 If this variable is defined, an environment variable 656 named "ver" is created by U-Boot showing the U-Boot 657 version as printed by the "version" command. 658 This variable is readonly. 659 660- Real-Time Clock: 661 662 When CONFIG_CMD_DATE is selected, the type of the RTC 663 has to be selected, too. Define exactly one of the 664 following options: 665 666 CONFIG_RTC_MPC8xx - use internal RTC of MPC8xx 667 CONFIG_RTC_PCF8563 - use Philips PCF8563 RTC 668 CONFIG_RTC_MC13783 - use MC13783 RTC 669 CONFIG_RTC_MC146818 - use MC146818 RTC 670 CONFIG_RTC_DS1307 - use Maxim, Inc. DS1307 RTC 671 CONFIG_RTC_DS1337 - use Maxim, Inc. DS1337 RTC 672 CONFIG_RTC_DS1338 - use Maxim, Inc. DS1338 RTC 673 CONFIG_RTC_DS164x - use Dallas DS164x RTC 674 CONFIG_RTC_ISL1208 - use Intersil ISL1208 RTC 675 CONFIG_RTC_MAX6900 - use Maxim, Inc. MAX6900 RTC 676 CFG_RTC_DS1337_NOOSC - Turn off the OSC output for DS1337 677 678 Note that if the RTC uses I2C, then the I2C interface 679 must also be configured. See I2C Support, below. 680 681- Timestamp Support: 682 683 When CONFIG_TIMESTAMP is selected, the timestamp 684 (date and time) of an image is printed by image 685 commands like bootm or iminfo. This option is 686 automatically enabled when you select CONFIG_CMD_DATE . 687 688- Partition Support: 689 CONFIG_MAC_PARTITION and/or CONFIG_DOS_PARTITION 690 and/or CONFIG_ISO_PARTITION 691 692 If IDE or SCSI support is enabled (CONFIG_CMD_IDE or 693 CONFIG_CMD_SCSI) you must configure support for at 694 least one partition type as well. 695 696- IDE Reset method: 697 CONFIG_IDE_RESET_ROUTINE - this is defined in several 698 board configurations files but used nowhere! 699 700 CONFIG_IDE_RESET - is this is defined, IDE Reset will 701 be performed by calling the function 702 ide_set_reset(int reset) 703 which has to be defined in a board specific file 704 705- ATAPI Support: 706 CONFIG_ATAPI 707 708 Set this to enable ATAPI support. 709 710- LBA48 Support 711 CONFIG_LBA48 712 713 Set this to enable support for disks larger than 137GB 714 Also look at CFG_64BIT_LBA ,CFG_64BIT_VSPRINTF and CFG_64BIT_STRTOUL 715 Whithout these , LBA48 support uses 32bit variables and will 'only' 716 support disks up to 2.1TB. 717 718 CFG_64BIT_LBA: 719 When enabled, makes the IDE subsystem use 64bit sector addresses. 720 Default is 32bit. 721 722- SCSI Support: 723 At the moment only there is only support for the 724 SYM53C8XX SCSI controller; define 725 CONFIG_SCSI_SYM53C8XX to enable it. 726 727 CFG_SCSI_MAX_LUN [8], CFG_SCSI_MAX_SCSI_ID [7] and 728 CFG_SCSI_MAX_DEVICE [CFG_SCSI_MAX_SCSI_ID * 729 CFG_SCSI_MAX_LUN] can be adjusted to define the 730 maximum numbers of LUNs, SCSI ID's and target 731 devices. 732 CFG_SCSI_SYM53C8XX_CCF to fix clock timing (80Mhz) 733 734- NETWORK Support (PCI): 735 CONFIG_E1000 736 Support for Intel 8254x gigabit chips. 737 738 CONFIG_E1000_FALLBACK_MAC 739 default MAC for empty EEPROM after production. 740 741 CONFIG_EEPRO100 742 Support for Intel 82557/82559/82559ER chips. 743 Optional CONFIG_EEPRO100_SROM_WRITE enables EEPROM 744 write routine for first time initialisation. 745 746 CONFIG_TULIP 747 Support for Digital 2114x chips. 748 Optional CONFIG_TULIP_SELECT_MEDIA for board specific 749 modem chip initialisation (KS8761/QS6611). 750 751 CONFIG_NATSEMI 752 Support for National dp83815 chips. 753 754 CONFIG_NS8382X 755 Support for National dp8382[01] gigabit chips. 756 757- NETWORK Support (other): 758 759 CONFIG_DRIVER_LAN91C96 760 Support for SMSC's LAN91C96 chips. 761 762 CONFIG_LAN91C96_BASE 763 Define this to hold the physical address 764 of the LAN91C96's I/O space 765 766 CONFIG_LAN91C96_USE_32_BIT 767 Define this to enable 32 bit addressing 768 769 CONFIG_DRIVER_SMC91111 770 Support for SMSC's LAN91C111 chip 771 772 CONFIG_SMC91111_BASE 773 Define this to hold the physical address 774 of the device (I/O space) 775 776 CONFIG_SMC_USE_32_BIT 777 Define this if data bus is 32 bits 778 779 CONFIG_SMC_USE_IOFUNCS 780 Define this to use i/o functions instead of macros 781 (some hardware wont work with macros) 782 783 CONFIG_DRIVER_SMC911X 784 Support for SMSC's LAN911x and LAN921x chips 785 786 CONFIG_DRIVER_SMC911X_BASE 787 Define this to hold the physical address 788 of the device (I/O space) 789 790 CONFIG_DRIVER_SMC911X_32_BIT 791 Define this if data bus is 32 bits 792 793 CONFIG_DRIVER_SMC911X_16_BIT 794 Define this if data bus is 16 bits. If your processor 795 automatically converts one 32 bit word to two 16 bit 796 words you may also try CONFIG_DRIVER_SMC911X_32_BIT. 797 798- USB Support: 799 At the moment only the UHCI host controller is 800 supported (PIP405, MIP405, MPC5200); define 801 CONFIG_USB_UHCI to enable it. 802 define CONFIG_USB_KEYBOARD to enable the USB Keyboard 803 and define CONFIG_USB_STORAGE to enable the USB 804 storage devices. 805 Note: 806 Supported are USB Keyboards and USB Floppy drives 807 (TEAC FD-05PUB). 808 MPC5200 USB requires additional defines: 809 CONFIG_USB_CLOCK 810 for 528 MHz Clock: 0x0001bbbb 811 CONFIG_USB_CONFIG 812 for differential drivers: 0x00001000 813 for single ended drivers: 0x00005000 814 CFG_USB_EVENT_POLL 815 May be defined to allow interrupt polling 816 instead of using asynchronous interrupts 817 818- USB Device: 819 Define the below if you wish to use the USB console. 820 Once firmware is rebuilt from a serial console issue the 821 command "setenv stdin usbtty; setenv stdout usbtty" and 822 attach your USB cable. The Unix command "dmesg" should print 823 it has found a new device. The environment variable usbtty 824 can be set to gserial or cdc_acm to enable your device to 825 appear to a USB host as a Linux gserial device or a 826 Common Device Class Abstract Control Model serial device. 827 If you select usbtty = gserial you should be able to enumerate 828 a Linux host by 829 # modprobe usbserial vendor=0xVendorID product=0xProductID 830 else if using cdc_acm, simply setting the environment 831 variable usbtty to be cdc_acm should suffice. The following 832 might be defined in YourBoardName.h 833 834 CONFIG_USB_DEVICE 835 Define this to build a UDC device 836 837 CONFIG_USB_TTY 838 Define this to have a tty type of device available to 839 talk to the UDC device 840 841 CFG_CONSOLE_IS_IN_ENV 842 Define this if you want stdin, stdout &/or stderr to 843 be set to usbtty. 844 845 mpc8xx: 846 CFG_USB_EXTC_CLK 0xBLAH 847 Derive USB clock from external clock "blah" 848 - CFG_USB_EXTC_CLK 0x02 849 850 CFG_USB_BRG_CLK 0xBLAH 851 Derive USB clock from brgclk 852 - CFG_USB_BRG_CLK 0x04 853 854 If you have a USB-IF assigned VendorID then you may wish to 855 define your own vendor specific values either in BoardName.h 856 or directly in usbd_vendor_info.h. If you don't define 857 CONFIG_USBD_MANUFACTURER, CONFIG_USBD_PRODUCT_NAME, 858 CONFIG_USBD_VENDORID and CONFIG_USBD_PRODUCTID, then U-Boot 859 should pretend to be a Linux device to it's target host. 860 861 CONFIG_USBD_MANUFACTURER 862 Define this string as the name of your company for 863 - CONFIG_USBD_MANUFACTURER "my company" 864 865 CONFIG_USBD_PRODUCT_NAME 866 Define this string as the name of your product 867 - CONFIG_USBD_PRODUCT_NAME "acme usb device" 868 869 CONFIG_USBD_VENDORID 870 Define this as your assigned Vendor ID from the USB 871 Implementors Forum. This *must* be a genuine Vendor ID 872 to avoid polluting the USB namespace. 873 - CONFIG_USBD_VENDORID 0xFFFF 874 875 CONFIG_USBD_PRODUCTID 876 Define this as the unique Product ID 877 for your device 878 - CONFIG_USBD_PRODUCTID 0xFFFF 879 880 881- MMC Support: 882 The MMC controller on the Intel PXA is supported. To 883 enable this define CONFIG_MMC. The MMC can be 884 accessed from the boot prompt by mapping the device 885 to physical memory similar to flash. Command line is 886 enabled with CONFIG_CMD_MMC. The MMC driver also works with 887 the FAT fs. This is enabled with CONFIG_CMD_FAT. 888 889- Journaling Flash filesystem support: 890 CONFIG_JFFS2_NAND, CONFIG_JFFS2_NAND_OFF, CONFIG_JFFS2_NAND_SIZE, 891 CONFIG_JFFS2_NAND_DEV 892 Define these for a default partition on a NAND device 893 894 CFG_JFFS2_FIRST_SECTOR, 895 CFG_JFFS2_FIRST_BANK, CFG_JFFS2_NUM_BANKS 896 Define these for a default partition on a NOR device 897 898 CFG_JFFS_CUSTOM_PART 899 Define this to create an own partition. You have to provide a 900 function struct part_info* jffs2_part_info(int part_num) 901 902 If you define only one JFFS2 partition you may also want to 903 #define CFG_JFFS_SINGLE_PART 1 904 to disable the command chpart. This is the default when you 905 have not defined a custom partition 906 907- Keyboard Support: 908 CONFIG_ISA_KEYBOARD 909 910 Define this to enable standard (PC-Style) keyboard 911 support 912 913 CONFIG_I8042_KBD 914 Standard PC keyboard driver with US (is default) and 915 GERMAN key layout (switch via environment 'keymap=de') support. 916 Export function i8042_kbd_init, i8042_tstc and i8042_getc 917 for cfb_console. Supports cursor blinking. 918 919- Video support: 920 CONFIG_VIDEO 921 922 Define this to enable video support (for output to 923 video). 924 925 CONFIG_VIDEO_CT69000 926 927 Enable Chips & Technologies 69000 Video chip 928 929 CONFIG_VIDEO_SMI_LYNXEM 930 Enable Silicon Motion SMI 712/710/810 Video chip. The 931 video output is selected via environment 'videoout' 932 (1 = LCD and 2 = CRT). If videoout is undefined, CRT is 933 assumed. 934 935 For the CT69000 and SMI_LYNXEM drivers, videomode is 936 selected via environment 'videomode'. Two different ways 937 are possible: 938 - "videomode=num" 'num' is a standard LiLo mode numbers. 939 Following standard modes are supported (* is default): 940 941 Colors 640x480 800x600 1024x768 1152x864 1280x1024 942 -------------+--------------------------------------------- 943 8 bits | 0x301* 0x303 0x305 0x161 0x307 944 15 bits | 0x310 0x313 0x316 0x162 0x319 945 16 bits | 0x311 0x314 0x317 0x163 0x31A 946 24 bits | 0x312 0x315 0x318 ? 0x31B 947 -------------+--------------------------------------------- 948 (i.e. setenv videomode 317; saveenv; reset;) 949 950 - "videomode=bootargs" all the video parameters are parsed 951 from the bootargs. (See drivers/video/videomodes.c) 952 953 954 CONFIG_VIDEO_SED13806 955 Enable Epson SED13806 driver. This driver supports 8bpp 956 and 16bpp modes defined by CONFIG_VIDEO_SED13806_8BPP 957 or CONFIG_VIDEO_SED13806_16BPP 958 959- Keyboard Support: 960 CONFIG_KEYBOARD 961 962 Define this to enable a custom keyboard support. 963 This simply calls drv_keyboard_init() which must be 964 defined in your board-specific files. 965 The only board using this so far is RBC823. 966 967- LCD Support: CONFIG_LCD 968 969 Define this to enable LCD support (for output to LCD 970 display); also select one of the supported displays 971 by defining one of these: 972 973 CONFIG_ATMEL_LCD: 974 975 HITACHI TX09D70VM1CCA, 3.5", 240x320. 976 977 CONFIG_NEC_NL6448AC33: 978 979 NEC NL6448AC33-18. Active, color, single scan. 980 981 CONFIG_NEC_NL6448BC20 982 983 NEC NL6448BC20-08. 6.5", 640x480. 984 Active, color, single scan. 985 986 CONFIG_NEC_NL6448BC33_54 987 988 NEC NL6448BC33-54. 10.4", 640x480. 989 Active, color, single scan. 990 991 CONFIG_SHARP_16x9 992 993 Sharp 320x240. Active, color, single scan. 994 It isn't 16x9, and I am not sure what it is. 995 996 CONFIG_SHARP_LQ64D341 997 998 Sharp LQ64D341 display, 640x480. 999 Active, color, single scan. 1000 1001 CONFIG_HLD1045 1002 1003 HLD1045 display, 640x480. 1004 Active, color, single scan. 1005 1006 CONFIG_OPTREX_BW 1007 1008 Optrex CBL50840-2 NF-FW 99 22 M5 1009 or 1010 Hitachi LMG6912RPFC-00T 1011 or 1012 Hitachi SP14Q002 1013 1014 320x240. Black & white. 1015 1016 Normally display is black on white background; define 1017 CFG_WHITE_ON_BLACK to get it inverted. 1018 1019- Splash Screen Support: CONFIG_SPLASH_SCREEN 1020 1021 If this option is set, the environment is checked for 1022 a variable "splashimage". If found, the usual display 1023 of logo, copyright and system information on the LCD 1024 is suppressed and the BMP image at the address 1025 specified in "splashimage" is loaded instead. The 1026 console is redirected to the "nulldev", too. This 1027 allows for a "silent" boot where a splash screen is 1028 loaded very quickly after power-on. 1029 1030- Gzip compressed BMP image support: CONFIG_VIDEO_BMP_GZIP 1031 1032 If this option is set, additionally to standard BMP 1033 images, gzipped BMP images can be displayed via the 1034 splashscreen support or the bmp command. 1035 1036- Compression support: 1037 CONFIG_BZIP2 1038 1039 If this option is set, support for bzip2 compressed 1040 images is included. If not, only uncompressed and gzip 1041 compressed images are supported. 1042 1043 NOTE: the bzip2 algorithm requires a lot of RAM, so 1044 the malloc area (as defined by CFG_MALLOC_LEN) should 1045 be at least 4MB. 1046 1047 CONFIG_LZMA 1048 1049 If this option is set, support for lzma compressed 1050 images is included. 1051 1052 Note: The LZMA algorithm adds between 2 and 4KB of code and it 1053 requires an amount of dynamic memory that is given by the 1054 formula: 1055 1056 (1846 + 768 << (lc + lp)) * sizeof(uint16) 1057 1058 Where lc and lp stand for, respectively, Literal context bits 1059 and Literal pos bits. 1060 1061 This value is upper-bounded by 14MB in the worst case. Anyway, 1062 for a ~4MB large kernel image, we have lc=3 and lp=0 for a 1063 total amount of (1846 + 768 << (3 + 0)) * 2 = ~41KB... that is 1064 a very small buffer. 1065 1066 Use the lzmainfo tool to determinate the lc and lp values and 1067 then calculate the amount of needed dynamic memory (ensuring 1068 the appropriate CFG_MALLOC_LEN value). 1069 1070- MII/PHY support: 1071 CONFIG_PHY_ADDR 1072 1073 The address of PHY on MII bus. 1074 1075 CONFIG_PHY_CLOCK_FREQ (ppc4xx) 1076 1077 The clock frequency of the MII bus 1078 1079 CONFIG_PHY_GIGE 1080 1081 If this option is set, support for speed/duplex 1082 detection of gigabit PHY is included. 1083 1084 CONFIG_PHY_RESET_DELAY 1085 1086 Some PHY like Intel LXT971A need extra delay after 1087 reset before any MII register access is possible. 1088 For such PHY, set this option to the usec delay 1089 required. (minimum 300usec for LXT971A) 1090 1091 CONFIG_PHY_CMD_DELAY (ppc4xx) 1092 1093 Some PHY like Intel LXT971A need extra delay after 1094 command issued before MII status register can be read 1095 1096- Ethernet address: 1097 CONFIG_ETHADDR 1098 CONFIG_ETH1ADDR 1099 CONFIG_ETH2ADDR 1100 CONFIG_ETH3ADDR 1101 CONFIG_ETH4ADDR 1102 CONFIG_ETH5ADDR 1103 1104 Define a default value for Ethernet address to use 1105 for the respective Ethernet interface, in case this 1106 is not determined automatically. 1107 1108- IP address: 1109 CONFIG_IPADDR 1110 1111 Define a default value for the IP address to use for 1112 the default Ethernet interface, in case this is not 1113 determined through e.g. bootp. 1114 1115- Server IP address: 1116 CONFIG_SERVERIP 1117 1118 Defines a default value for the IP address of a TFTP 1119 server to contact when using the "tftboot" command. 1120 1121- Multicast TFTP Mode: 1122 CONFIG_MCAST_TFTP 1123 1124 Defines whether you want to support multicast TFTP as per 1125 rfc-2090; for example to work with atftp. Lets lots of targets 1126 tftp down the same boot image concurrently. Note: the Ethernet 1127 driver in use must provide a function: mcast() to join/leave a 1128 multicast group. 1129 1130 CONFIG_BOOTP_RANDOM_DELAY 1131- BOOTP Recovery Mode: 1132 CONFIG_BOOTP_RANDOM_DELAY 1133 1134 If you have many targets in a network that try to 1135 boot using BOOTP, you may want to avoid that all 1136 systems send out BOOTP requests at precisely the same 1137 moment (which would happen for instance at recovery 1138 from a power failure, when all systems will try to 1139 boot, thus flooding the BOOTP server. Defining 1140 CONFIG_BOOTP_RANDOM_DELAY causes a random delay to be 1141 inserted before sending out BOOTP requests. The 1142 following delays are inserted then: 1143 1144 1st BOOTP request: delay 0 ... 1 sec 1145 2nd BOOTP request: delay 0 ... 2 sec 1146 3rd BOOTP request: delay 0 ... 4 sec 1147 4th and following 1148 BOOTP requests: delay 0 ... 8 sec 1149 1150- DHCP Advanced Options: 1151 You can fine tune the DHCP functionality by defining 1152 CONFIG_BOOTP_* symbols: 1153 1154 CONFIG_BOOTP_SUBNETMASK 1155 CONFIG_BOOTP_GATEWAY 1156 CONFIG_BOOTP_HOSTNAME 1157 CONFIG_BOOTP_NISDOMAIN 1158 CONFIG_BOOTP_BOOTPATH 1159 CONFIG_BOOTP_BOOTFILESIZE 1160 CONFIG_BOOTP_DNS 1161 CONFIG_BOOTP_DNS2 1162 CONFIG_BOOTP_SEND_HOSTNAME 1163 CONFIG_BOOTP_NTPSERVER 1164 CONFIG_BOOTP_TIMEOFFSET 1165 CONFIG_BOOTP_VENDOREX 1166 1167 CONFIG_BOOTP_SERVERIP - TFTP server will be the serverip 1168 environment variable, not the BOOTP server. 1169 1170 CONFIG_BOOTP_DNS2 - If a DHCP client requests the DNS 1171 serverip from a DHCP server, it is possible that more 1172 than one DNS serverip is offered to the client. 1173 If CONFIG_BOOTP_DNS2 is enabled, the secondary DNS 1174 serverip will be stored in the additional environment 1175 variable "dnsip2". The first DNS serverip is always 1176 stored in the variable "dnsip", when CONFIG_BOOTP_DNS 1177 is defined. 1178 1179 CONFIG_BOOTP_SEND_HOSTNAME - Some DHCP servers are capable 1180 to do a dynamic update of a DNS server. To do this, they 1181 need the hostname of the DHCP requester. 1182 If CONFIG_BOOTP_SEND_HOSTNAME is defined, the content 1183 of the "hostname" environment variable is passed as 1184 option 12 to the DHCP server. 1185 1186 CONFIG_BOOTP_DHCP_REQUEST_DELAY 1187 1188 A 32bit value in microseconds for a delay between 1189 receiving a "DHCP Offer" and sending the "DHCP Request". 1190 This fixes a problem with certain DHCP servers that don't 1191 respond 100% of the time to a "DHCP request". E.g. On an 1192 AT91RM9200 processor running at 180MHz, this delay needed 1193 to be *at least* 15,000 usec before a Windows Server 2003 1194 DHCP server would reply 100% of the time. I recommend at 1195 least 50,000 usec to be safe. The alternative is to hope 1196 that one of the retries will be successful but note that 1197 the DHCP timeout and retry process takes a longer than 1198 this delay. 1199 1200 - CDP Options: 1201 CONFIG_CDP_DEVICE_ID 1202 1203 The device id used in CDP trigger frames. 1204 1205 CONFIG_CDP_DEVICE_ID_PREFIX 1206 1207 A two character string which is prefixed to the MAC address 1208 of the device. 1209 1210 CONFIG_CDP_PORT_ID 1211 1212 A printf format string which contains the ascii name of 1213 the port. Normally is set to "eth%d" which sets 1214 eth0 for the first Ethernet, eth1 for the second etc. 1215 1216 CONFIG_CDP_CAPABILITIES 1217 1218 A 32bit integer which indicates the device capabilities; 1219 0x00000010 for a normal host which does not forwards. 1220 1221 CONFIG_CDP_VERSION 1222 1223 An ascii string containing the version of the software. 1224 1225 CONFIG_CDP_PLATFORM 1226 1227 An ascii string containing the name of the platform. 1228 1229 CONFIG_CDP_TRIGGER 1230 1231 A 32bit integer sent on the trigger. 1232 1233 CONFIG_CDP_POWER_CONSUMPTION 1234 1235 A 16bit integer containing the power consumption of the 1236 device in .1 of milliwatts. 1237 1238 CONFIG_CDP_APPLIANCE_VLAN_TYPE 1239 1240 A byte containing the id of the VLAN. 1241 1242- Status LED: CONFIG_STATUS_LED 1243 1244 Several configurations allow to display the current 1245 status using a LED. For instance, the LED will blink 1246 fast while running U-Boot code, stop blinking as 1247 soon as a reply to a BOOTP request was received, and 1248 start blinking slow once the Linux kernel is running 1249 (supported by a status LED driver in the Linux 1250 kernel). Defining CONFIG_STATUS_LED enables this 1251 feature in U-Boot. 1252 1253- CAN Support: CONFIG_CAN_DRIVER 1254 1255 Defining CONFIG_CAN_DRIVER enables CAN driver support 1256 on those systems that support this (optional) 1257 feature, like the TQM8xxL modules. 1258 1259- I2C Support: CONFIG_HARD_I2C | CONFIG_SOFT_I2C 1260 1261 These enable I2C serial bus commands. Defining either of 1262 (but not both of) CONFIG_HARD_I2C or CONFIG_SOFT_I2C will 1263 include the appropriate I2C driver for the selected CPU. 1264 1265 This will allow you to use i2c commands at the u-boot 1266 command line (as long as you set CONFIG_CMD_I2C in 1267 CONFIG_COMMANDS) and communicate with i2c based realtime 1268 clock chips. See common/cmd_i2c.c for a description of the 1269 command line interface. 1270 1271 CONFIG_I2C_CMD_TREE is a recommended option that places 1272 all I2C commands under a single 'i2c' root command. The 1273 older 'imm', 'imd', 'iprobe' etc. commands are considered 1274 deprecated and may disappear in the future. 1275 1276 CONFIG_HARD_I2C selects a hardware I2C controller. 1277 1278 CONFIG_SOFT_I2C configures u-boot to use a software (aka 1279 bit-banging) driver instead of CPM or similar hardware 1280 support for I2C. 1281 1282 There are several other quantities that must also be 1283 defined when you define CONFIG_HARD_I2C or CONFIG_SOFT_I2C. 1284 1285 In both cases you will need to define CFG_I2C_SPEED 1286 to be the frequency (in Hz) at which you wish your i2c bus 1287 to run and CFG_I2C_SLAVE to be the address of this node (ie 1288 the CPU's i2c node address). 1289 1290 Now, the u-boot i2c code for the mpc8xx (cpu/mpc8xx/i2c.c) 1291 sets the CPU up as a master node and so its address should 1292 therefore be cleared to 0 (See, eg, MPC823e User's Manual 1293 p.16-473). So, set CFG_I2C_SLAVE to 0. 1294 1295 That's all that's required for CONFIG_HARD_I2C. 1296 1297 If you use the software i2c interface (CONFIG_SOFT_I2C) 1298 then the following macros need to be defined (examples are 1299 from include/configs/lwmon.h): 1300 1301 I2C_INIT 1302 1303 (Optional). Any commands necessary to enable the I2C 1304 controller or configure ports. 1305 1306 eg: #define I2C_INIT (immr->im_cpm.cp_pbdir |= PB_SCL) 1307 1308 I2C_PORT 1309 1310 (Only for MPC8260 CPU). The I/O port to use (the code 1311 assumes both bits are on the same port). Valid values 1312 are 0..3 for ports A..D. 1313 1314 I2C_ACTIVE 1315 1316 The code necessary to make the I2C data line active 1317 (driven). If the data line is open collector, this 1318 define can be null. 1319 1320 eg: #define I2C_ACTIVE (immr->im_cpm.cp_pbdir |= PB_SDA) 1321 1322 I2C_TRISTATE 1323 1324 The code necessary to make the I2C data line tri-stated 1325 (inactive). If the data line is open collector, this 1326 define can be null. 1327 1328 eg: #define I2C_TRISTATE (immr->im_cpm.cp_pbdir &= ~PB_SDA) 1329 1330 I2C_READ 1331 1332 Code that returns TRUE if the I2C data line is high, 1333 FALSE if it is low. 1334 1335 eg: #define I2C_READ ((immr->im_cpm.cp_pbdat & PB_SDA) != 0) 1336 1337 I2C_SDA(bit) 1338 1339 If <bit> is TRUE, sets the I2C data line high. If it 1340 is FALSE, it clears it (low). 1341 1342 eg: #define I2C_SDA(bit) \ 1343 if(bit) immr->im_cpm.cp_pbdat |= PB_SDA; \ 1344 else immr->im_cpm.cp_pbdat &= ~PB_SDA 1345 1346 I2C_SCL(bit) 1347 1348 If <bit> is TRUE, sets the I2C clock line high. If it 1349 is FALSE, it clears it (low). 1350 1351 eg: #define I2C_SCL(bit) \ 1352 if(bit) immr->im_cpm.cp_pbdat |= PB_SCL; \ 1353 else immr->im_cpm.cp_pbdat &= ~PB_SCL 1354 1355 I2C_DELAY 1356 1357 This delay is invoked four times per clock cycle so this 1358 controls the rate of data transfer. The data rate thus 1359 is 1 / (I2C_DELAY * 4). Often defined to be something 1360 like: 1361 1362 #define I2C_DELAY udelay(2) 1363 1364 CFG_I2C_INIT_BOARD 1365 1366 When a board is reset during an i2c bus transfer 1367 chips might think that the current transfer is still 1368 in progress. On some boards it is possible to access 1369 the i2c SCLK line directly, either by using the 1370 processor pin as a GPIO or by having a second pin 1371 connected to the bus. If this option is defined a 1372 custom i2c_init_board() routine in boards/xxx/board.c 1373 is run early in the boot sequence. 1374 1375 CONFIG_I2CFAST (PPC405GP|PPC405EP only) 1376 1377 This option enables configuration of bi_iic_fast[] flags 1378 in u-boot bd_info structure based on u-boot environment 1379 variable "i2cfast". (see also i2cfast) 1380 1381 CONFIG_I2C_MULTI_BUS 1382 1383 This option allows the use of multiple I2C buses, each of which 1384 must have a controller. At any point in time, only one bus is 1385 active. To switch to a different bus, use the 'i2c dev' command. 1386 Note that bus numbering is zero-based. 1387 1388 CFG_I2C_NOPROBES 1389 1390 This option specifies a list of I2C devices that will be skipped 1391 when the 'i2c probe' command is issued (or 'iprobe' using the legacy 1392 command). If CONFIG_I2C_MULTI_BUS is set, specify a list of bus-device 1393 pairs. Otherwise, specify a 1D array of device addresses 1394 1395 e.g. 1396 #undef CONFIG_I2C_MULTI_BUS 1397 #define CFG_I2C_NOPROBES {0x50,0x68} 1398 1399 will skip addresses 0x50 and 0x68 on a board with one I2C bus 1400 1401 #define CONFIG_I2C_MULTI_BUS 1402 #define CFG_I2C_MULTI_NOPROBES {{0,0x50},{0,0x68},{1,0x54}} 1403 1404 will skip addresses 0x50 and 0x68 on bus 0 and address 0x54 on bus 1 1405 1406 CFG_SPD_BUS_NUM 1407 1408 If defined, then this indicates the I2C bus number for DDR SPD. 1409 If not defined, then U-Boot assumes that SPD is on I2C bus 0. 1410 1411 CFG_RTC_BUS_NUM 1412 1413 If defined, then this indicates the I2C bus number for the RTC. 1414 If not defined, then U-Boot assumes that RTC is on I2C bus 0. 1415 1416 CFG_DTT_BUS_NUM 1417 1418 If defined, then this indicates the I2C bus number for the DTT. 1419 If not defined, then U-Boot assumes that DTT is on I2C bus 0. 1420 1421 CFG_I2C_DTT_ADDR: 1422 1423 If defined, specifies the I2C address of the DTT device. 1424 If not defined, then U-Boot uses predefined value for 1425 specified DTT device. 1426 1427 CONFIG_FSL_I2C 1428 1429 Define this option if you want to use Freescale's I2C driver in 1430 drivers/i2c/fsl_i2c.c. 1431 1432 1433- SPI Support: CONFIG_SPI 1434 1435 Enables SPI driver (so far only tested with 1436 SPI EEPROM, also an instance works with Crystal A/D and 1437 D/As on the SACSng board) 1438 1439 CONFIG_SPI_X 1440 1441 Enables extended (16-bit) SPI EEPROM addressing. 1442 (symmetrical to CONFIG_I2C_X) 1443 1444 CONFIG_SOFT_SPI 1445 1446 Enables a software (bit-bang) SPI driver rather than 1447 using hardware support. This is a general purpose 1448 driver that only requires three general I/O port pins 1449 (two outputs, one input) to function. If this is 1450 defined, the board configuration must define several 1451 SPI configuration items (port pins to use, etc). For 1452 an example, see include/configs/sacsng.h. 1453 1454 CONFIG_HARD_SPI 1455 1456 Enables a hardware SPI driver for general-purpose reads 1457 and writes. As with CONFIG_SOFT_SPI, the board configuration 1458 must define a list of chip-select function pointers. 1459 Currently supported on some MPC8xxx processors. For an 1460 example, see include/configs/mpc8349emds.h. 1461 1462 CONFIG_MXC_SPI 1463 1464 Enables the driver for the SPI controllers on i.MX and MXC 1465 SoCs. Currently only i.MX31 is supported. 1466 1467- FPGA Support: CONFIG_FPGA 1468 1469 Enables FPGA subsystem. 1470 1471 CONFIG_FPGA_<vendor> 1472 1473 Enables support for specific chip vendors. 1474 (ALTERA, XILINX) 1475 1476 CONFIG_FPGA_<family> 1477 1478 Enables support for FPGA family. 1479 (SPARTAN2, SPARTAN3, VIRTEX2, CYCLONE2, ACEX1K, ACEX) 1480 1481 CONFIG_FPGA_COUNT 1482 1483 Specify the number of FPGA devices to support. 1484 1485 CFG_FPGA_PROG_FEEDBACK 1486 1487 Enable printing of hash marks during FPGA configuration. 1488 1489 CFG_FPGA_CHECK_BUSY 1490 1491 Enable checks on FPGA configuration interface busy 1492 status by the configuration function. This option 1493 will require a board or device specific function to 1494 be written. 1495 1496 CONFIG_FPGA_DELAY 1497 1498 If defined, a function that provides delays in the FPGA 1499 configuration driver. 1500 1501 CFG_FPGA_CHECK_CTRLC 1502 Allow Control-C to interrupt FPGA configuration 1503 1504 CFG_FPGA_CHECK_ERROR 1505 1506 Check for configuration errors during FPGA bitfile 1507 loading. For example, abort during Virtex II 1508 configuration if the INIT_B line goes low (which 1509 indicated a CRC error). 1510 1511 CFG_FPGA_WAIT_INIT 1512 1513 Maximum time to wait for the INIT_B line to deassert 1514 after PROB_B has been deasserted during a Virtex II 1515 FPGA configuration sequence. The default time is 500 1516 ms. 1517 1518 CFG_FPGA_WAIT_BUSY 1519 1520 Maximum time to wait for BUSY to deassert during 1521 Virtex II FPGA configuration. The default is 5 ms. 1522 1523 CFG_FPGA_WAIT_CONFIG 1524 1525 Time to wait after FPGA configuration. The default is 1526 200 ms. 1527 1528- Configuration Management: 1529 CONFIG_IDENT_STRING 1530 1531 If defined, this string will be added to the U-Boot 1532 version information (U_BOOT_VERSION) 1533 1534- Vendor Parameter Protection: 1535 1536 U-Boot considers the values of the environment 1537 variables "serial#" (Board Serial Number) and 1538 "ethaddr" (Ethernet Address) to be parameters that 1539 are set once by the board vendor / manufacturer, and 1540 protects these variables from casual modification by 1541 the user. Once set, these variables are read-only, 1542 and write or delete attempts are rejected. You can 1543 change this behaviour: 1544 1545 If CONFIG_ENV_OVERWRITE is #defined in your config 1546 file, the write protection for vendor parameters is 1547 completely disabled. Anybody can change or delete 1548 these parameters. 1549 1550 Alternatively, if you #define _both_ CONFIG_ETHADDR 1551 _and_ CONFIG_OVERWRITE_ETHADDR_ONCE, a default 1552 Ethernet address is installed in the environment, 1553 which can be changed exactly ONCE by the user. [The 1554 serial# is unaffected by this, i. e. it remains 1555 read-only.] 1556 1557- Protected RAM: 1558 CONFIG_PRAM 1559 1560 Define this variable to enable the reservation of 1561 "protected RAM", i. e. RAM which is not overwritten 1562 by U-Boot. Define CONFIG_PRAM to hold the number of 1563 kB you want to reserve for pRAM. You can overwrite 1564 this default value by defining an environment 1565 variable "pram" to the number of kB you want to 1566 reserve. Note that the board info structure will 1567 still show the full amount of RAM. If pRAM is 1568 reserved, a new environment variable "mem" will 1569 automatically be defined to hold the amount of 1570 remaining RAM in a form that can be passed as boot 1571 argument to Linux, for instance like that: 1572 1573 setenv bootargs ... mem=\${mem} 1574 saveenv 1575 1576 This way you can tell Linux not to use this memory, 1577 either, which results in a memory region that will 1578 not be affected by reboots. 1579 1580 *WARNING* If your board configuration uses automatic 1581 detection of the RAM size, you must make sure that 1582 this memory test is non-destructive. So far, the 1583 following board configurations are known to be 1584 "pRAM-clean": 1585 1586 ETX094, IVMS8, IVML24, SPD8xx, TQM8xxL, 1587 HERMES, IP860, RPXlite, LWMON, LANTEC, 1588 PCU_E, FLAGADM, TQM8260 1589 1590- Error Recovery: 1591 CONFIG_PANIC_HANG 1592 1593 Define this variable to stop the system in case of a 1594 fatal error, so that you have to reset it manually. 1595 This is probably NOT a good idea for an embedded 1596 system where you want the system to reboot 1597 automatically as fast as possible, but it may be 1598 useful during development since you can try to debug 1599 the conditions that lead to the situation. 1600 1601 CONFIG_NET_RETRY_COUNT 1602 1603 This variable defines the number of retries for 1604 network operations like ARP, RARP, TFTP, or BOOTP 1605 before giving up the operation. If not defined, a 1606 default value of 5 is used. 1607 1608 CONFIG_ARP_TIMEOUT 1609 1610 Timeout waiting for an ARP reply in milliseconds. 1611 1612- Command Interpreter: 1613 CONFIG_AUTO_COMPLETE 1614 1615 Enable auto completion of commands using TAB. 1616 1617 Note that this feature has NOT been implemented yet 1618 for the "hush" shell. 1619 1620 1621 CFG_HUSH_PARSER 1622 1623 Define this variable to enable the "hush" shell (from 1624 Busybox) as command line interpreter, thus enabling 1625 powerful command line syntax like 1626 if...then...else...fi conditionals or `&&' and '||' 1627 constructs ("shell scripts"). 1628 1629 If undefined, you get the old, much simpler behaviour 1630 with a somewhat smaller memory footprint. 1631 1632 1633 CFG_PROMPT_HUSH_PS2 1634 1635 This defines the secondary prompt string, which is 1636 printed when the command interpreter needs more input 1637 to complete a command. Usually "> ". 1638 1639 Note: 1640 1641 In the current implementation, the local variables 1642 space and global environment variables space are 1643 separated. Local variables are those you define by 1644 simply typing `name=value'. To access a local 1645 variable later on, you have write `$name' or 1646 `${name}'; to execute the contents of a variable 1647 directly type `$name' at the command prompt. 1648 1649 Global environment variables are those you use 1650 setenv/printenv to work with. To run a command stored 1651 in such a variable, you need to use the run command, 1652 and you must not use the '$' sign to access them. 1653 1654 To store commands and special characters in a 1655 variable, please use double quotation marks 1656 surrounding the whole text of the variable, instead 1657 of the backslashes before semicolons and special 1658 symbols. 1659 1660- Commandline Editing and History: 1661 CONFIG_CMDLINE_EDITING 1662 1663 Enable editing and History functions for interactive 1664 commandline input operations 1665 1666- Default Environment: 1667 CONFIG_EXTRA_ENV_SETTINGS 1668 1669 Define this to contain any number of null terminated 1670 strings (variable = value pairs) that will be part of 1671 the default environment compiled into the boot image. 1672 1673 For example, place something like this in your 1674 board's config file: 1675 1676 #define CONFIG_EXTRA_ENV_SETTINGS \ 1677 "myvar1=value1\0" \ 1678 "myvar2=value2\0" 1679 1680 Warning: This method is based on knowledge about the 1681 internal format how the environment is stored by the 1682 U-Boot code. This is NOT an official, exported 1683 interface! Although it is unlikely that this format 1684 will change soon, there is no guarantee either. 1685 You better know what you are doing here. 1686 1687 Note: overly (ab)use of the default environment is 1688 discouraged. Make sure to check other ways to preset 1689 the environment like the autoscript function or the 1690 boot command first. 1691 1692- DataFlash Support: 1693 CONFIG_HAS_DATAFLASH 1694 1695 Defining this option enables DataFlash features and 1696 allows to read/write in Dataflash via the standard 1697 commands cp, md... 1698 1699- SystemACE Support: 1700 CONFIG_SYSTEMACE 1701 1702 Adding this option adds support for Xilinx SystemACE 1703 chips attached via some sort of local bus. The address 1704 of the chip must also be defined in the 1705 CFG_SYSTEMACE_BASE macro. For example: 1706 1707 #define CONFIG_SYSTEMACE 1708 #define CFG_SYSTEMACE_BASE 0xf0000000 1709 1710 When SystemACE support is added, the "ace" device type 1711 becomes available to the fat commands, i.e. fatls. 1712 1713- TFTP Fixed UDP Port: 1714 CONFIG_TFTP_PORT 1715 1716 If this is defined, the environment variable tftpsrcp 1717 is used to supply the TFTP UDP source port value. 1718 If tftpsrcp isn't defined, the normal pseudo-random port 1719 number generator is used. 1720 1721 Also, the environment variable tftpdstp is used to supply 1722 the TFTP UDP destination port value. If tftpdstp isn't 1723 defined, the normal port 69 is used. 1724 1725 The purpose for tftpsrcp is to allow a TFTP server to 1726 blindly start the TFTP transfer using the pre-configured 1727 target IP address and UDP port. This has the effect of 1728 "punching through" the (Windows XP) firewall, allowing 1729 the remainder of the TFTP transfer to proceed normally. 1730 A better solution is to properly configure the firewall, 1731 but sometimes that is not allowed. 1732 1733- Show boot progress: 1734 CONFIG_SHOW_BOOT_PROGRESS 1735 1736 Defining this option allows to add some board- 1737 specific code (calling a user-provided function 1738 "show_boot_progress(int)") that enables you to show 1739 the system's boot progress on some display (for 1740 example, some LED's) on your board. At the moment, 1741 the following checkpoints are implemented: 1742 1743- Automatic software updates via TFTP server 1744 CONFIG_UPDATE_TFTP 1745 CONFIG_UPDATE_TFTP_CNT_MAX 1746 CONFIG_UPDATE_TFTP_MSEC_MAX 1747 1748 These options enable and control the auto-update feature; 1749 for a more detailed description refer to doc/README.update. 1750 1751Legacy uImage format: 1752 1753 Arg Where When 1754 1 common/cmd_bootm.c before attempting to boot an image 1755 -1 common/cmd_bootm.c Image header has bad magic number 1756 2 common/cmd_bootm.c Image header has correct magic number 1757 -2 common/cmd_bootm.c Image header has bad checksum 1758 3 common/cmd_bootm.c Image header has correct checksum 1759 -3 common/cmd_bootm.c Image data has bad checksum 1760 4 common/cmd_bootm.c Image data has correct checksum 1761 -4 common/cmd_bootm.c Image is for unsupported architecture 1762 5 common/cmd_bootm.c Architecture check OK 1763 -5 common/cmd_bootm.c Wrong Image Type (not kernel, multi) 1764 6 common/cmd_bootm.c Image Type check OK 1765 -6 common/cmd_bootm.c gunzip uncompression error 1766 -7 common/cmd_bootm.c Unimplemented compression type 1767 7 common/cmd_bootm.c Uncompression OK 1768 8 common/cmd_bootm.c No uncompress/copy overwrite error 1769 -9 common/cmd_bootm.c Unsupported OS (not Linux, BSD, VxWorks, QNX) 1770 1771 9 common/image.c Start initial ramdisk verification 1772 -10 common/image.c Ramdisk header has bad magic number 1773 -11 common/image.c Ramdisk header has bad checksum 1774 10 common/image.c Ramdisk header is OK 1775 -12 common/image.c Ramdisk data has bad checksum 1776 11 common/image.c Ramdisk data has correct checksum 1777 12 common/image.c Ramdisk verification complete, start loading 1778 -13 common/image.c Wrong Image Type (not PPC Linux ramdisk) 1779 13 common/image.c Start multifile image verification 1780 14 common/image.c No initial ramdisk, no multifile, continue. 1781 1782 15 lib_<arch>/bootm.c All preparation done, transferring control to OS 1783 1784 -30 lib_ppc/board.c Fatal error, hang the system 1785 -31 post/post.c POST test failed, detected by post_output_backlog() 1786 -32 post/post.c POST test failed, detected by post_run_single() 1787 1788 34 common/cmd_doc.c before loading a Image from a DOC device 1789 -35 common/cmd_doc.c Bad usage of "doc" command 1790 35 common/cmd_doc.c correct usage of "doc" command 1791 -36 common/cmd_doc.c No boot device 1792 36 common/cmd_doc.c correct boot device 1793 -37 common/cmd_doc.c Unknown Chip ID on boot device 1794 37 common/cmd_doc.c correct chip ID found, device available 1795 -38 common/cmd_doc.c Read Error on boot device 1796 38 common/cmd_doc.c reading Image header from DOC device OK 1797 -39 common/cmd_doc.c Image header has bad magic number 1798 39 common/cmd_doc.c Image header has correct magic number 1799 -40 common/cmd_doc.c Error reading Image from DOC device 1800 40 common/cmd_doc.c Image header has correct magic number 1801 41 common/cmd_ide.c before loading a Image from a IDE device 1802 -42 common/cmd_ide.c Bad usage of "ide" command 1803 42 common/cmd_ide.c correct usage of "ide" command 1804 -43 common/cmd_ide.c No boot device 1805 43 common/cmd_ide.c boot device found 1806 -44 common/cmd_ide.c Device not available 1807 44 common/cmd_ide.c Device available 1808 -45 common/cmd_ide.c wrong partition selected 1809 45 common/cmd_ide.c partition selected 1810 -46 common/cmd_ide.c Unknown partition table 1811 46 common/cmd_ide.c valid partition table found 1812 -47 common/cmd_ide.c Invalid partition type 1813 47 common/cmd_ide.c correct partition type 1814 -48 common/cmd_ide.c Error reading Image Header on boot device 1815 48 common/cmd_ide.c reading Image Header from IDE device OK 1816 -49 common/cmd_ide.c Image header has bad magic number 1817 49 common/cmd_ide.c Image header has correct magic number 1818 -50 common/cmd_ide.c Image header has bad checksum 1819 50 common/cmd_ide.c Image header has correct checksum 1820 -51 common/cmd_ide.c Error reading Image from IDE device 1821 51 common/cmd_ide.c reading Image from IDE device OK 1822 52 common/cmd_nand.c before loading a Image from a NAND device 1823 -53 common/cmd_nand.c Bad usage of "nand" command 1824 53 common/cmd_nand.c correct usage of "nand" command 1825 -54 common/cmd_nand.c No boot device 1826 54 common/cmd_nand.c boot device found 1827 -55 common/cmd_nand.c Unknown Chip ID on boot device 1828 55 common/cmd_nand.c correct chip ID found, device available 1829 -56 common/cmd_nand.c Error reading Image Header on boot device 1830 56 common/cmd_nand.c reading Image Header from NAND device OK 1831 -57 common/cmd_nand.c Image header has bad magic number 1832 57 common/cmd_nand.c Image header has correct magic number 1833 -58 common/cmd_nand.c Error reading Image from NAND device 1834 58 common/cmd_nand.c reading Image from NAND device OK 1835 1836 -60 common/env_common.c Environment has a bad CRC, using default 1837 1838 64 net/eth.c starting with Ethernet configuration. 1839 -64 net/eth.c no Ethernet found. 1840 65 net/eth.c Ethernet found. 1841 1842 -80 common/cmd_net.c usage wrong 1843 80 common/cmd_net.c before calling NetLoop() 1844 -81 common/cmd_net.c some error in NetLoop() occurred 1845 81 common/cmd_net.c NetLoop() back without error 1846 -82 common/cmd_net.c size == 0 (File with size 0 loaded) 1847 82 common/cmd_net.c trying automatic boot 1848 83 common/cmd_net.c running autoscript 1849 -83 common/cmd_net.c some error in automatic boot or autoscript 1850 84 common/cmd_net.c end without errors 1851 1852FIT uImage format: 1853 1854 Arg Where When 1855 100 common/cmd_bootm.c Kernel FIT Image has correct format 1856 -100 common/cmd_bootm.c Kernel FIT Image has incorrect format 1857 101 common/cmd_bootm.c No Kernel subimage unit name, using configuration 1858 -101 common/cmd_bootm.c Can't get configuration for kernel subimage 1859 102 common/cmd_bootm.c Kernel unit name specified 1860 -103 common/cmd_bootm.c Can't get kernel subimage node offset 1861 103 common/cmd_bootm.c Found configuration node 1862 104 common/cmd_bootm.c Got kernel subimage node offset 1863 -104 common/cmd_bootm.c Kernel subimage hash verification failed 1864 105 common/cmd_bootm.c Kernel subimage hash verification OK 1865 -105 common/cmd_bootm.c Kernel subimage is for unsupported architecture 1866 106 common/cmd_bootm.c Architecture check OK 1867 -106 common/cmd_bootm.c Kernel subimage has wrong type 1868 107 common/cmd_bootm.c Kernel subimage type OK 1869 -107 common/cmd_bootm.c Can't get kernel subimage data/size 1870 108 common/cmd_bootm.c Got kernel subimage data/size 1871 -108 common/cmd_bootm.c Wrong image type (not legacy, FIT) 1872 -109 common/cmd_bootm.c Can't get kernel subimage type 1873 -110 common/cmd_bootm.c Can't get kernel subimage comp 1874 -111 common/cmd_bootm.c Can't get kernel subimage os 1875 -112 common/cmd_bootm.c Can't get kernel subimage load address 1876 -113 common/cmd_bootm.c Image uncompress/copy overwrite error 1877 1878 120 common/image.c Start initial ramdisk verification 1879 -120 common/image.c Ramdisk FIT image has incorrect format 1880 121 common/image.c Ramdisk FIT image has correct format 1881 122 common/image.c No ramdisk subimage unit name, using configuration 1882 -122 common/image.c Can't get configuration for ramdisk subimage 1883 123 common/image.c Ramdisk unit name specified 1884 -124 common/image.c Can't get ramdisk subimage node offset 1885 125 common/image.c Got ramdisk subimage node offset 1886 -125 common/image.c Ramdisk subimage hash verification failed 1887 126 common/image.c Ramdisk subimage hash verification OK 1888 -126 common/image.c Ramdisk subimage for unsupported architecture 1889 127 common/image.c Architecture check OK 1890 -127 common/image.c Can't get ramdisk subimage data/size 1891 128 common/image.c Got ramdisk subimage data/size 1892 129 common/image.c Can't get ramdisk load address 1893 -129 common/image.c Got ramdisk load address 1894 1895 -130 common/cmd_doc.c Incorrect FIT image format 1896 131 common/cmd_doc.c FIT image format OK 1897 1898 -140 common/cmd_ide.c Incorrect FIT image format 1899 141 common/cmd_ide.c FIT image format OK 1900 1901 -150 common/cmd_nand.c Incorrect FIT image format 1902 151 common/cmd_nand.c FIT image format OK 1903 1904 1905Modem Support: 1906-------------- 1907 1908[so far only for SMDK2400 and TRAB boards] 1909 1910- Modem support enable: 1911 CONFIG_MODEM_SUPPORT 1912 1913- RTS/CTS Flow control enable: 1914 CONFIG_HWFLOW 1915 1916- Modem debug support: 1917 CONFIG_MODEM_SUPPORT_DEBUG 1918 1919 Enables debugging stuff (char screen[1024], dbg()) 1920 for modem support. Useful only with BDI2000. 1921 1922- Interrupt support (PPC): 1923 1924 There are common interrupt_init() and timer_interrupt() 1925 for all PPC archs. interrupt_init() calls interrupt_init_cpu() 1926 for CPU specific initialization. interrupt_init_cpu() 1927 should set decrementer_count to appropriate value. If 1928 CPU resets decrementer automatically after interrupt 1929 (ppc4xx) it should set decrementer_count to zero. 1930 timer_interrupt() calls timer_interrupt_cpu() for CPU 1931 specific handling. If board has watchdog / status_led 1932 / other_activity_monitor it works automatically from 1933 general timer_interrupt(). 1934 1935- General: 1936 1937 In the target system modem support is enabled when a 1938 specific key (key combination) is pressed during 1939 power-on. Otherwise U-Boot will boot normally 1940 (autoboot). The key_pressed() function is called from 1941 board_init(). Currently key_pressed() is a dummy 1942 function, returning 1 and thus enabling modem 1943 initialization. 1944 1945 If there are no modem init strings in the 1946 environment, U-Boot proceed to autoboot; the 1947 previous output (banner, info printfs) will be 1948 suppressed, though. 1949 1950 See also: doc/README.Modem 1951 1952 1953Configuration Settings: 1954----------------------- 1955 1956- CFG_LONGHELP: Defined when you want long help messages included; 1957 undefine this when you're short of memory. 1958 1959- CFG_PROMPT: This is what U-Boot prints on the console to 1960 prompt for user input. 1961 1962- CFG_CBSIZE: Buffer size for input from the Console 1963 1964- CFG_PBSIZE: Buffer size for Console output 1965 1966- CFG_MAXARGS: max. Number of arguments accepted for monitor commands 1967 1968- CFG_BARGSIZE: Buffer size for Boot Arguments which are passed to 1969 the application (usually a Linux kernel) when it is 1970 booted 1971 1972- CFG_BAUDRATE_TABLE: 1973 List of legal baudrate settings for this board. 1974 1975- CFG_CONSOLE_INFO_QUIET 1976 Suppress display of console information at boot. 1977 1978- CFG_CONSOLE_IS_IN_ENV 1979 If the board specific function 1980 extern int overwrite_console (void); 1981 returns 1, the stdin, stderr and stdout are switched to the 1982 serial port, else the settings in the environment are used. 1983 1984- CFG_CONSOLE_OVERWRITE_ROUTINE 1985 Enable the call to overwrite_console(). 1986 1987- CFG_CONSOLE_ENV_OVERWRITE 1988 Enable overwrite of previous console environment settings. 1989 1990- CFG_MEMTEST_START, CFG_MEMTEST_END: 1991 Begin and End addresses of the area used by the 1992 simple memory test. 1993 1994- CFG_ALT_MEMTEST: 1995 Enable an alternate, more extensive memory test. 1996 1997- CFG_MEMTEST_SCRATCH: 1998 Scratch address used by the alternate memory test 1999 You only need to set this if address zero isn't writeable 2000 2001- CFG_MEM_TOP_HIDE (PPC only): 2002 If CFG_MEM_TOP_HIDE is defined in the board config header, 2003 this specified memory area will get subtracted from the top 2004 (end) of RAM and won't get "touched" at all by U-Boot. By 2005 fixing up gd->ram_size the Linux kernel should gets passed 2006 the now "corrected" memory size and won't touch it either. 2007 This should work for arch/ppc and arch/powerpc. Only Linux 2008 board ports in arch/powerpc with bootwrapper support that 2009 recalculate the memory size from the SDRAM controller setup 2010 will have to get fixed in Linux additionally. 2011 2012 This option can be used as a workaround for the 440EPx/GRx 2013 CHIP 11 errata where the last 256 bytes in SDRAM shouldn't 2014 be touched. 2015 2016 WARNING: Please make sure that this value is a multiple of 2017 the Linux page size (normally 4k). If this is not the case, 2018 then the end address of the Linux memory will be located at a 2019 non page size aligned address and this could cause major 2020 problems. 2021 2022- CFG_TFTP_LOADADDR: 2023 Default load address for network file downloads 2024 2025- CFG_LOADS_BAUD_CHANGE: 2026 Enable temporary baudrate change while serial download 2027 2028- CFG_SDRAM_BASE: 2029 Physical start address of SDRAM. _Must_ be 0 here. 2030 2031- CFG_MBIO_BASE: 2032 Physical start address of Motherboard I/O (if using a 2033 Cogent motherboard) 2034 2035- CFG_FLASH_BASE: 2036 Physical start address of Flash memory. 2037 2038- CFG_MONITOR_BASE: 2039 Physical start address of boot monitor code (set by 2040 make config files to be same as the text base address 2041 (TEXT_BASE) used when linking) - same as 2042 CFG_FLASH_BASE when booting from flash. 2043 2044- CFG_MONITOR_LEN: 2045 Size of memory reserved for monitor code, used to 2046 determine _at_compile_time_ (!) if the environment is 2047 embedded within the U-Boot image, or in a separate 2048 flash sector. 2049 2050- CFG_MALLOC_LEN: 2051 Size of DRAM reserved for malloc() use. 2052 2053- CFG_BOOTM_LEN: 2054 Normally compressed uImages are limited to an 2055 uncompressed size of 8 MBytes. If this is not enough, 2056 you can define CFG_BOOTM_LEN in your board config file 2057 to adjust this setting to your needs. 2058 2059- CFG_BOOTMAPSZ: 2060 Maximum size of memory mapped by the startup code of 2061 the Linux kernel; all data that must be processed by 2062 the Linux kernel (bd_info, boot arguments, FDT blob if 2063 used) must be put below this limit, unless "bootm_low" 2064 enviroment variable is defined and non-zero. In such case 2065 all data for the Linux kernel must be between "bootm_low" 2066 and "bootm_low" + CFG_BOOTMAPSZ. 2067 2068- CFG_MAX_FLASH_BANKS: 2069 Max number of Flash memory banks 2070 2071- CFG_MAX_FLASH_SECT: 2072 Max number of sectors on a Flash chip 2073 2074- CFG_FLASH_ERASE_TOUT: 2075 Timeout for Flash erase operations (in ms) 2076 2077- CFG_FLASH_WRITE_TOUT: 2078 Timeout for Flash write operations (in ms) 2079 2080- CFG_FLASH_LOCK_TOUT 2081 Timeout for Flash set sector lock bit operation (in ms) 2082 2083- CFG_FLASH_UNLOCK_TOUT 2084 Timeout for Flash clear lock bits operation (in ms) 2085 2086- CFG_FLASH_PROTECTION 2087 If defined, hardware flash sectors protection is used 2088 instead of U-Boot software protection. 2089 2090- CFG_DIRECT_FLASH_TFTP: 2091 2092 Enable TFTP transfers directly to flash memory; 2093 without this option such a download has to be 2094 performed in two steps: (1) download to RAM, and (2) 2095 copy from RAM to flash. 2096 2097 The two-step approach is usually more reliable, since 2098 you can check if the download worked before you erase 2099 the flash, but in some situations (when system RAM is 2100 too limited to allow for a temporary copy of the 2101 downloaded image) this option may be very useful. 2102 2103- CFG_FLASH_CFI: 2104 Define if the flash driver uses extra elements in the 2105 common flash structure for storing flash geometry. 2106 2107- CONFIG_FLASH_CFI_DRIVER 2108 This option also enables the building of the cfi_flash driver 2109 in the drivers directory 2110 2111- CFG_FLASH_USE_BUFFER_WRITE 2112 Use buffered writes to flash. 2113 2114- CONFIG_FLASH_SPANSION_S29WS_N 2115 s29ws-n MirrorBit flash has non-standard addresses for buffered 2116 write commands. 2117 2118- CFG_FLASH_QUIET_TEST 2119 If this option is defined, the common CFI flash doesn't 2120 print it's warning upon not recognized FLASH banks. This 2121 is useful, if some of the configured banks are only 2122 optionally available. 2123 2124- CONFIG_FLASH_SHOW_PROGRESS 2125 If defined (must be an integer), print out countdown 2126 digits and dots. Recommended value: 45 (9..1) for 80 2127 column displays, 15 (3..1) for 40 column displays. 2128 2129- CFG_RX_ETH_BUFFER: 2130 Defines the number of Ethernet receive buffers. On some 2131 Ethernet controllers it is recommended to set this value 2132 to 8 or even higher (EEPRO100 or 405 EMAC), since all 2133 buffers can be full shortly after enabling the interface 2134 on high Ethernet traffic. 2135 Defaults to 4 if not defined. 2136 2137The following definitions that deal with the placement and management 2138of environment data (variable area); in general, we support the 2139following configurations: 2140 2141- CONFIG_ENV_IS_IN_FLASH: 2142 2143 Define this if the environment is in flash memory. 2144 2145 a) The environment occupies one whole flash sector, which is 2146 "embedded" in the text segment with the U-Boot code. This 2147 happens usually with "bottom boot sector" or "top boot 2148 sector" type flash chips, which have several smaller 2149 sectors at the start or the end. For instance, such a 2150 layout can have sector sizes of 8, 2x4, 16, Nx32 kB. In 2151 such a case you would place the environment in one of the 2152 4 kB sectors - with U-Boot code before and after it. With 2153 "top boot sector" type flash chips, you would put the 2154 environment in one of the last sectors, leaving a gap 2155 between U-Boot and the environment. 2156 2157 - CONFIG_ENV_OFFSET: 2158 2159 Offset of environment data (variable area) to the 2160 beginning of flash memory; for instance, with bottom boot 2161 type flash chips the second sector can be used: the offset 2162 for this sector is given here. 2163 2164 CONFIG_ENV_OFFSET is used relative to CFG_FLASH_BASE. 2165 2166 - CONFIG_ENV_ADDR: 2167 2168 This is just another way to specify the start address of 2169 the flash sector containing the environment (instead of 2170 CONFIG_ENV_OFFSET). 2171 2172 - CONFIG_ENV_SECT_SIZE: 2173 2174 Size of the sector containing the environment. 2175 2176 2177 b) Sometimes flash chips have few, equal sized, BIG sectors. 2178 In such a case you don't want to spend a whole sector for 2179 the environment. 2180 2181 - CONFIG_ENV_SIZE: 2182 2183 If you use this in combination with CONFIG_ENV_IS_IN_FLASH 2184 and CONFIG_ENV_SECT_SIZE, you can specify to use only a part 2185 of this flash sector for the environment. This saves 2186 memory for the RAM copy of the environment. 2187 2188 It may also save flash memory if you decide to use this 2189 when your environment is "embedded" within U-Boot code, 2190 since then the remainder of the flash sector could be used 2191 for U-Boot code. It should be pointed out that this is 2192 STRONGLY DISCOURAGED from a robustness point of view: 2193 updating the environment in flash makes it always 2194 necessary to erase the WHOLE sector. If something goes 2195 wrong before the contents has been restored from a copy in 2196 RAM, your target system will be dead. 2197 2198 - CONFIG_ENV_ADDR_REDUND 2199 CONFIG_ENV_SIZE_REDUND 2200 2201 These settings describe a second storage area used to hold 2202 a redundant copy of the environment data, so that there is 2203 a valid backup copy in case there is a power failure during 2204 a "saveenv" operation. 2205 2206BE CAREFUL! Any changes to the flash layout, and some changes to the 2207source code will make it necessary to adapt <board>/u-boot.lds* 2208accordingly! 2209 2210 2211- CONFIG_ENV_IS_IN_NVRAM: 2212 2213 Define this if you have some non-volatile memory device 2214 (NVRAM, battery buffered SRAM) which you want to use for the 2215 environment. 2216 2217 - CONFIG_ENV_ADDR: 2218 - CONFIG_ENV_SIZE: 2219 2220 These two #defines are used to determine the memory area you 2221 want to use for environment. It is assumed that this memory 2222 can just be read and written to, without any special 2223 provision. 2224 2225BE CAREFUL! The first access to the environment happens quite early 2226in U-Boot initalization (when we try to get the setting of for the 2227console baudrate). You *MUST* have mapped your NVRAM area then, or 2228U-Boot will hang. 2229 2230Please note that even with NVRAM we still use a copy of the 2231environment in RAM: we could work on NVRAM directly, but we want to 2232keep settings there always unmodified except somebody uses "saveenv" 2233to save the current settings. 2234 2235 2236- CONFIG_ENV_IS_IN_EEPROM: 2237 2238 Use this if you have an EEPROM or similar serial access 2239 device and a driver for it. 2240 2241 - CONFIG_ENV_OFFSET: 2242 - CONFIG_ENV_SIZE: 2243 2244 These two #defines specify the offset and size of the 2245 environment area within the total memory of your EEPROM. 2246 2247 - CFG_I2C_EEPROM_ADDR: 2248 If defined, specified the chip address of the EEPROM device. 2249 The default address is zero. 2250 2251 - CFG_EEPROM_PAGE_WRITE_BITS: 2252 If defined, the number of bits used to address bytes in a 2253 single page in the EEPROM device. A 64 byte page, for example 2254 would require six bits. 2255 2256 - CFG_EEPROM_PAGE_WRITE_DELAY_MS: 2257 If defined, the number of milliseconds to delay between 2258 page writes. The default is zero milliseconds. 2259 2260 - CFG_I2C_EEPROM_ADDR_LEN: 2261 The length in bytes of the EEPROM memory array address. Note 2262 that this is NOT the chip address length! 2263 2264 - CFG_I2C_EEPROM_ADDR_OVERFLOW: 2265 EEPROM chips that implement "address overflow" are ones 2266 like Catalyst 24WC04/08/16 which has 9/10/11 bits of 2267 address and the extra bits end up in the "chip address" bit 2268 slots. This makes a 24WC08 (1Kbyte) chip look like four 256 2269 byte chips. 2270 2271 Note that we consider the length of the address field to 2272 still be one byte because the extra address bits are hidden 2273 in the chip address. 2274 2275 - CFG_EEPROM_SIZE: 2276 The size in bytes of the EEPROM device. 2277 2278 2279- CONFIG_ENV_IS_IN_DATAFLASH: 2280 2281 Define this if you have a DataFlash memory device which you 2282 want to use for the environment. 2283 2284 - CONFIG_ENV_OFFSET: 2285 - CONFIG_ENV_ADDR: 2286 - CONFIG_ENV_SIZE: 2287 2288 These three #defines specify the offset and size of the 2289 environment area within the total memory of your DataFlash placed 2290 at the specified address. 2291 2292- CONFIG_ENV_IS_IN_NAND: 2293 2294 Define this if you have a NAND device which you want to use 2295 for the environment. 2296 2297 - CONFIG_ENV_OFFSET: 2298 - CONFIG_ENV_SIZE: 2299 2300 These two #defines specify the offset and size of the environment 2301 area within the first NAND device. 2302 2303 - CONFIG_ENV_OFFSET_REDUND 2304 2305 This setting describes a second storage area of CONFIG_ENV_SIZE 2306 size used to hold a redundant copy of the environment data, 2307 so that there is a valid backup copy in case there is a 2308 power failure during a "saveenv" operation. 2309 2310 Note: CONFIG_ENV_OFFSET and CONFIG_ENV_OFFSET_REDUND must be aligned 2311 to a block boundary, and CONFIG_ENV_SIZE must be a multiple of 2312 the NAND devices block size. 2313 2314- CFG_SPI_INIT_OFFSET 2315 2316 Defines offset to the initial SPI buffer area in DPRAM. The 2317 area is used at an early stage (ROM part) if the environment 2318 is configured to reside in the SPI EEPROM: We need a 520 byte 2319 scratch DPRAM area. It is used between the two initialization 2320 calls (spi_init_f() and spi_init_r()). A value of 0xB00 seems 2321 to be a good choice since it makes it far enough from the 2322 start of the data area as well as from the stack pointer. 2323 2324Please note that the environment is read-only until the monitor 2325has been relocated to RAM and a RAM copy of the environment has been 2326created; also, when using EEPROM you will have to use getenv_r() 2327until then to read environment variables. 2328 2329The environment is protected by a CRC32 checksum. Before the monitor 2330is relocated into RAM, as a result of a bad CRC you will be working 2331with the compiled-in default environment - *silently*!!! [This is 2332necessary, because the first environment variable we need is the 2333"baudrate" setting for the console - if we have a bad CRC, we don't 2334have any device yet where we could complain.] 2335 2336Note: once the monitor has been relocated, then it will complain if 2337the default environment is used; a new CRC is computed as soon as you 2338use the "saveenv" command to store a valid environment. 2339 2340- CFG_FAULT_ECHO_LINK_DOWN: 2341 Echo the inverted Ethernet link state to the fault LED. 2342 2343 Note: If this option is active, then CFG_FAULT_MII_ADDR 2344 also needs to be defined. 2345 2346- CFG_FAULT_MII_ADDR: 2347 MII address of the PHY to check for the Ethernet link state. 2348 2349- CFG_64BIT_VSPRINTF: 2350 Makes vsprintf (and all *printf functions) support printing 2351 of 64bit values by using the L quantifier 2352 2353- CFG_64BIT_STRTOUL: 2354 Adds simple_strtoull that returns a 64bit value 2355 2356Low Level (hardware related) configuration options: 2357--------------------------------------------------- 2358 2359- CFG_CACHELINE_SIZE: 2360 Cache Line Size of the CPU. 2361 2362- CFG_DEFAULT_IMMR: 2363 Default address of the IMMR after system reset. 2364 2365 Needed on some 8260 systems (MPC8260ADS, PQ2FADS-ZU, 2366 and RPXsuper) to be able to adjust the position of 2367 the IMMR register after a reset. 2368 2369- Floppy Disk Support: 2370 CFG_FDC_DRIVE_NUMBER 2371 2372 the default drive number (default value 0) 2373 2374 CFG_ISA_IO_STRIDE 2375 2376 defines the spacing between FDC chipset registers 2377 (default value 1) 2378 2379 CFG_ISA_IO_OFFSET 2380 2381 defines the offset of register from address. It 2382 depends on which part of the data bus is connected to 2383 the FDC chipset. (default value 0) 2384 2385 If CFG_ISA_IO_STRIDE CFG_ISA_IO_OFFSET and 2386 CFG_FDC_DRIVE_NUMBER are undefined, they take their 2387 default value. 2388 2389 if CFG_FDC_HW_INIT is defined, then the function 2390 fdc_hw_init() is called at the beginning of the FDC 2391 setup. fdc_hw_init() must be provided by the board 2392 source code. It is used to make hardware dependant 2393 initializations. 2394 2395- CFG_IMMR: Physical address of the Internal Memory. 2396 DO NOT CHANGE unless you know exactly what you're 2397 doing! (11-4) [MPC8xx/82xx systems only] 2398 2399- CFG_INIT_RAM_ADDR: 2400 2401 Start address of memory area that can be used for 2402 initial data and stack; please note that this must be 2403 writable memory that is working WITHOUT special 2404 initialization, i. e. you CANNOT use normal RAM which 2405 will become available only after programming the 2406 memory controller and running certain initialization 2407 sequences. 2408 2409 U-Boot uses the following memory types: 2410 - MPC8xx and MPC8260: IMMR (internal memory of the CPU) 2411 - MPC824X: data cache 2412 - PPC4xx: data cache 2413 2414- CFG_GBL_DATA_OFFSET: 2415 2416 Offset of the initial data structure in the memory 2417 area defined by CFG_INIT_RAM_ADDR. Usually 2418 CFG_GBL_DATA_OFFSET is chosen such that the initial 2419 data is located at the end of the available space 2420 (sometimes written as (CFG_INIT_RAM_END - 2421 CFG_INIT_DATA_SIZE), and the initial stack is just 2422 below that area (growing from (CFG_INIT_RAM_ADDR + 2423 CFG_GBL_DATA_OFFSET) downward. 2424 2425 Note: 2426 On the MPC824X (or other systems that use the data 2427 cache for initial memory) the address chosen for 2428 CFG_INIT_RAM_ADDR is basically arbitrary - it must 2429 point to an otherwise UNUSED address space between 2430 the top of RAM and the start of the PCI space. 2431 2432- CFG_SIUMCR: SIU Module Configuration (11-6) 2433 2434- CFG_SYPCR: System Protection Control (11-9) 2435 2436- CFG_TBSCR: Time Base Status and Control (11-26) 2437 2438- CFG_PISCR: Periodic Interrupt Status and Control (11-31) 2439 2440- CFG_PLPRCR: PLL, Low-Power, and Reset Control Register (15-30) 2441 2442- CFG_SCCR: System Clock and reset Control Register (15-27) 2443 2444- CFG_OR_TIMING_SDRAM: 2445 SDRAM timing 2446 2447- CFG_MAMR_PTA: 2448 periodic timer for refresh 2449 2450- CFG_DER: Debug Event Register (37-47) 2451 2452- FLASH_BASE0_PRELIM, FLASH_BASE1_PRELIM, CFG_REMAP_OR_AM, 2453 CFG_PRELIM_OR_AM, CFG_OR_TIMING_FLASH, CFG_OR0_REMAP, 2454 CFG_OR0_PRELIM, CFG_BR0_PRELIM, CFG_OR1_REMAP, CFG_OR1_PRELIM, 2455 CFG_BR1_PRELIM: 2456 Memory Controller Definitions: BR0/1 and OR0/1 (FLASH) 2457 2458- SDRAM_BASE2_PRELIM, SDRAM_BASE3_PRELIM, SDRAM_MAX_SIZE, 2459 CFG_OR_TIMING_SDRAM, CFG_OR2_PRELIM, CFG_BR2_PRELIM, 2460 CFG_OR3_PRELIM, CFG_BR3_PRELIM: 2461 Memory Controller Definitions: BR2/3 and OR2/3 (SDRAM) 2462 2463- CFG_MAMR_PTA, CFG_MPTPR_2BK_4K, CFG_MPTPR_1BK_4K, CFG_MPTPR_2BK_8K, 2464 CFG_MPTPR_1BK_8K, CFG_MAMR_8COL, CFG_MAMR_9COL: 2465 Machine Mode Register and Memory Periodic Timer 2466 Prescaler definitions (SDRAM timing) 2467 2468- CFG_I2C_UCODE_PATCH, CFG_I2C_DPMEM_OFFSET [0x1FC0]: 2469 enable I2C microcode relocation patch (MPC8xx); 2470 define relocation offset in DPRAM [DSP2] 2471 2472- CFG_SMC_UCODE_PATCH, CFG_SMC_DPMEM_OFFSET [0x1FC0]: 2473 enable SMC microcode relocation patch (MPC8xx); 2474 define relocation offset in DPRAM [SMC1] 2475 2476- CFG_SPI_UCODE_PATCH, CFG_SPI_DPMEM_OFFSET [0x1FC0]: 2477 enable SPI microcode relocation patch (MPC8xx); 2478 define relocation offset in DPRAM [SCC4] 2479 2480- CFG_USE_OSCCLK: 2481 Use OSCM clock mode on MBX8xx board. Be careful, 2482 wrong setting might damage your board. Read 2483 doc/README.MBX before setting this variable! 2484 2485- CFG_CPM_POST_WORD_ADDR: (MPC8xx, MPC8260 only) 2486 Offset of the bootmode word in DPRAM used by post 2487 (Power On Self Tests). This definition overrides 2488 #define'd default value in commproc.h resp. 2489 cpm_8260.h. 2490 2491- CFG_PCI_SLV_MEM_LOCAL, CFG_PCI_SLV_MEM_BUS, CFG_PICMR0_MASK_ATTRIB, 2492 CFG_PCI_MSTR0_LOCAL, CFG_PCIMSK0_MASK, CFG_PCI_MSTR1_LOCAL, 2493 CFG_PCIMSK1_MASK, CFG_PCI_MSTR_MEM_LOCAL, CFG_PCI_MSTR_MEM_BUS, 2494 CFG_CPU_PCI_MEM_START, CFG_PCI_MSTR_MEM_SIZE, CFG_POCMR0_MASK_ATTRIB, 2495 CFG_PCI_MSTR_MEMIO_LOCAL, CFG_PCI_MSTR_MEMIO_BUS, CPU_PCI_MEMIO_START, 2496 CFG_PCI_MSTR_MEMIO_SIZE, CFG_POCMR1_MASK_ATTRIB, CFG_PCI_MSTR_IO_LOCAL, 2497 CFG_PCI_MSTR_IO_BUS, CFG_CPU_PCI_IO_START, CFG_PCI_MSTR_IO_SIZE, 2498 CFG_POCMR2_MASK_ATTRIB: (MPC826x only) 2499 Overrides the default PCI memory map in cpu/mpc8260/pci.c if set. 2500 2501- CONFIG_SPD_EEPROM 2502 Get DDR timing information from an I2C EEPROM. Common 2503 with pluggable memory modules such as SODIMMs 2504 2505 SPD_EEPROM_ADDRESS 2506 I2C address of the SPD EEPROM 2507 2508- CFG_SPD_BUS_NUM 2509 If SPD EEPROM is on an I2C bus other than the first 2510 one, specify here. Note that the value must resolve 2511 to something your driver can deal with. 2512 2513- CFG_83XX_DDR_USES_CS0 2514 Only for 83xx systems. If specified, then DDR should 2515 be configured using CS0 and CS1 instead of CS2 and CS3. 2516 2517- CFG_83XX_DDR_USES_CS0 2518 Only for 83xx systems. If specified, then DDR should 2519 be configured using CS0 and CS1 instead of CS2 and CS3. 2520 2521- CONFIG_ETHER_ON_FEC[12] 2522 Define to enable FEC[12] on a 8xx series processor. 2523 2524- CONFIG_FEC[12]_PHY 2525 Define to the hardcoded PHY address which corresponds 2526 to the given FEC; i. e. 2527 #define CONFIG_FEC1_PHY 4 2528 means that the PHY with address 4 is connected to FEC1 2529 2530 When set to -1, means to probe for first available. 2531 2532- CONFIG_FEC[12]_PHY_NORXERR 2533 The PHY does not have a RXERR line (RMII only). 2534 (so program the FEC to ignore it). 2535 2536- CONFIG_RMII 2537 Enable RMII mode for all FECs. 2538 Note that this is a global option, we can't 2539 have one FEC in standard MII mode and another in RMII mode. 2540 2541- CONFIG_CRC32_VERIFY 2542 Add a verify option to the crc32 command. 2543 The syntax is: 2544 2545 => crc32 -v <address> <count> <crc32> 2546 2547 Where address/count indicate a memory area 2548 and crc32 is the correct crc32 which the 2549 area should have. 2550 2551- CONFIG_LOOPW 2552 Add the "loopw" memory command. This only takes effect if 2553 the memory commands are activated globally (CONFIG_CMD_MEM). 2554 2555- CONFIG_MX_CYCLIC 2556 Add the "mdc" and "mwc" memory commands. These are cyclic 2557 "md/mw" commands. 2558 Examples: 2559 2560 => mdc.b 10 4 500 2561 This command will print 4 bytes (10,11,12,13) each 500 ms. 2562 2563 => mwc.l 100 12345678 10 2564 This command will write 12345678 to address 100 all 10 ms. 2565 2566 This only takes effect if the memory commands are activated 2567 globally (CONFIG_CMD_MEM). 2568 2569- CONFIG_SKIP_LOWLEVEL_INIT 2570- CONFIG_SKIP_RELOCATE_UBOOT 2571 2572 [ARM only] If these variables are defined, then 2573 certain low level initializations (like setting up 2574 the memory controller) are omitted and/or U-Boot does 2575 not relocate itself into RAM. 2576 Normally these variables MUST NOT be defined. The 2577 only exception is when U-Boot is loaded (to RAM) by 2578 some other boot loader or by a debugger which 2579 performs these initializations itself. 2580 2581 2582Building the Software: 2583====================== 2584 2585Building U-Boot has been tested in several native build environments 2586and in many different cross environments. Of course we cannot support 2587all possibly existing versions of cross development tools in all 2588(potentially obsolete) versions. In case of tool chain problems we 2589recommend to use the ELDK (see http://www.denx.de/wiki/DULG/ELDK) 2590which is extensively used to build and test U-Boot. 2591 2592If you are not using a native environment, it is assumed that you 2593have GNU cross compiling tools available in your path. In this case, 2594you must set the environment variable CROSS_COMPILE in your shell. 2595Note that no changes to the Makefile or any other source files are 2596necessary. For example using the ELDK on a 4xx CPU, please enter: 2597 2598 $ CROSS_COMPILE=ppc_4xx- 2599 $ export CROSS_COMPILE 2600 2601U-Boot is intended to be simple to build. After installing the 2602sources you must configure U-Boot for one specific board type. This 2603is done by typing: 2604 2605 make NAME_config 2606 2607where "NAME_config" is the name of one of the existing configu- 2608rations; see the main Makefile for supported names. 2609 2610Note: for some board special configuration names may exist; check if 2611 additional information is available from the board vendor; for 2612 instance, the TQM823L systems are available without (standard) 2613 or with LCD support. You can select such additional "features" 2614 when choosing the configuration, i. e. 2615 2616 make TQM823L_config 2617 - will configure for a plain TQM823L, i. e. no LCD support 2618 2619 make TQM823L_LCD_config 2620 - will configure for a TQM823L with U-Boot console on LCD 2621 2622 etc. 2623 2624 2625Finally, type "make all", and you should get some working U-Boot 2626images ready for download to / installation on your system: 2627 2628- "u-boot.bin" is a raw binary image 2629- "u-boot" is an image in ELF binary format 2630- "u-boot.srec" is in Motorola S-Record format 2631 2632By default the build is performed locally and the objects are saved 2633in the source directory. One of the two methods can be used to change 2634this behavior and build U-Boot to some external directory: 2635 26361. Add O= to the make command line invocations: 2637 2638 make O=/tmp/build distclean 2639 make O=/tmp/build NAME_config 2640 make O=/tmp/build all 2641 26422. Set environment variable BUILD_DIR to point to the desired location: 2643 2644 export BUILD_DIR=/tmp/build 2645 make distclean 2646 make NAME_config 2647 make all 2648 2649Note that the command line "O=" setting overrides the BUILD_DIR environment 2650variable. 2651 2652 2653Please be aware that the Makefiles assume you are using GNU make, so 2654for instance on NetBSD you might need to use "gmake" instead of 2655native "make". 2656 2657 2658If the system board that you have is not listed, then you will need 2659to port U-Boot to your hardware platform. To do this, follow these 2660steps: 2661 26621. Add a new configuration option for your board to the toplevel 2663 "Makefile" and to the "MAKEALL" script, using the existing 2664 entries as examples. Note that here and at many other places 2665 boards and other names are listed in alphabetical sort order. Please 2666 keep this order. 26672. Create a new directory to hold your board specific code. Add any 2668 files you need. In your board directory, you will need at least 2669 the "Makefile", a "<board>.c", "flash.c" and "u-boot.lds". 26703. Create a new configuration file "include/configs/<board>.h" for 2671 your board 26723. If you're porting U-Boot to a new CPU, then also create a new 2673 directory to hold your CPU specific code. Add any files you need. 26744. Run "make <board>_config" with your new name. 26755. Type "make", and you should get a working "u-boot.srec" file 2676 to be installed on your target system. 26776. Debug and solve any problems that might arise. 2678 [Of course, this last step is much harder than it sounds.] 2679 2680 2681Testing of U-Boot Modifications, Ports to New Hardware, etc.: 2682============================================================== 2683 2684If you have modified U-Boot sources (for instance added a new board 2685or support for new devices, a new CPU, etc.) you are expected to 2686provide feedback to the other developers. The feedback normally takes 2687the form of a "patch", i. e. a context diff against a certain (latest 2688official or latest in the git repository) version of U-Boot sources. 2689 2690But before you submit such a patch, please verify that your modifi- 2691cation did not break existing code. At least make sure that *ALL* of 2692the supported boards compile WITHOUT ANY compiler warnings. To do so, 2693just run the "MAKEALL" script, which will configure and build U-Boot 2694for ALL supported system. Be warned, this will take a while. You can 2695select which (cross) compiler to use by passing a `CROSS_COMPILE' 2696environment variable to the script, i. e. to use the ELDK cross tools 2697you can type 2698 2699 CROSS_COMPILE=ppc_8xx- MAKEALL 2700 2701or to build on a native PowerPC system you can type 2702 2703 CROSS_COMPILE=' ' MAKEALL 2704 2705When using the MAKEALL script, the default behaviour is to build 2706U-Boot in the source directory. This location can be changed by 2707setting the BUILD_DIR environment variable. Also, for each target 2708built, the MAKEALL script saves two log files (<target>.ERR and 2709<target>.MAKEALL) in the <source dir>/LOG directory. This default 2710location can be changed by setting the MAKEALL_LOGDIR environment 2711variable. For example: 2712 2713 export BUILD_DIR=/tmp/build 2714 export MAKEALL_LOGDIR=/tmp/log 2715 CROSS_COMPILE=ppc_8xx- MAKEALL 2716 2717With the above settings build objects are saved in the /tmp/build, 2718log files are saved in the /tmp/log and the source tree remains clean 2719during the whole build process. 2720 2721 2722See also "U-Boot Porting Guide" below. 2723 2724 2725Monitor Commands - Overview: 2726============================ 2727 2728go - start application at address 'addr' 2729run - run commands in an environment variable 2730bootm - boot application image from memory 2731bootp - boot image via network using BootP/TFTP protocol 2732tftpboot- boot image via network using TFTP protocol 2733 and env variables "ipaddr" and "serverip" 2734 (and eventually "gatewayip") 2735rarpboot- boot image via network using RARP/TFTP protocol 2736diskboot- boot from IDE devicebootd - boot default, i.e., run 'bootcmd' 2737loads - load S-Record file over serial line 2738loadb - load binary file over serial line (kermit mode) 2739md - memory display 2740mm - memory modify (auto-incrementing) 2741nm - memory modify (constant address) 2742mw - memory write (fill) 2743cp - memory copy 2744cmp - memory compare 2745crc32 - checksum calculation 2746imd - i2c memory display 2747imm - i2c memory modify (auto-incrementing) 2748inm - i2c memory modify (constant address) 2749imw - i2c memory write (fill) 2750icrc32 - i2c checksum calculation 2751iprobe - probe to discover valid I2C chip addresses 2752iloop - infinite loop on address range 2753isdram - print SDRAM configuration information 2754sspi - SPI utility commands 2755base - print or set address offset 2756printenv- print environment variables 2757setenv - set environment variables 2758saveenv - save environment variables to persistent storage 2759protect - enable or disable FLASH write protection 2760erase - erase FLASH memory 2761flinfo - print FLASH memory information 2762bdinfo - print Board Info structure 2763iminfo - print header information for application image 2764coninfo - print console devices and informations 2765ide - IDE sub-system 2766loop - infinite loop on address range 2767loopw - infinite write loop on address range 2768mtest - simple RAM test 2769icache - enable or disable instruction cache 2770dcache - enable or disable data cache 2771reset - Perform RESET of the CPU 2772echo - echo args to console 2773version - print monitor version 2774help - print online help 2775? - alias for 'help' 2776 2777 2778Monitor Commands - Detailed Description: 2779======================================== 2780 2781TODO. 2782 2783For now: just type "help <command>". 2784 2785 2786Environment Variables: 2787====================== 2788 2789U-Boot supports user configuration using Environment Variables which 2790can be made persistent by saving to Flash memory. 2791 2792Environment Variables are set using "setenv", printed using 2793"printenv", and saved to Flash using "saveenv". Using "setenv" 2794without a value can be used to delete a variable from the 2795environment. As long as you don't save the environment you are 2796working with an in-memory copy. In case the Flash area containing the 2797environment is erased by accident, a default environment is provided. 2798 2799Some configuration options can be set using Environment Variables: 2800 2801 baudrate - see CONFIG_BAUDRATE 2802 2803 bootdelay - see CONFIG_BOOTDELAY 2804 2805 bootcmd - see CONFIG_BOOTCOMMAND 2806 2807 bootargs - Boot arguments when booting an RTOS image 2808 2809 bootfile - Name of the image to load with TFTP 2810 2811 bootm_low - Memory range available for image processing in the bootm 2812 command can be restricted. This variable is given as 2813 a hexadecimal number and defines lowest address allowed 2814 for use by the bootm command. See also "bootm_size" 2815 environment variable. Address defined by "bootm_low" is 2816 also the base of the initial memory mapping for the Linux 2817 kernel -- see the description of CFG_BOOTMAPSZ. 2818 2819 bootm_size - Memory range available for image processing in the bootm 2820 command can be restricted. This variable is given as 2821 a hexadecimal number and defines the size of the region 2822 allowed for use by the bootm command. See also "bootm_low" 2823 environment variable. 2824 2825 updatefile - Location of the software update file on a TFTP server, used 2826 by the automatic software update feature. Please refer to 2827 documentation in doc/README.update for more details. 2828 2829 autoload - if set to "no" (any string beginning with 'n'), 2830 "bootp" will just load perform a lookup of the 2831 configuration from the BOOTP server, but not try to 2832 load any image using TFTP 2833 2834 autoscript - if set to "yes" commands like "loadb", "loady", 2835 "bootp", "tftpb", "rarpboot" and "nfs" will attempt 2836 to automatically run script images (by internally 2837 calling "autoscript"). 2838 2839 autoscript_uname - if script image is in a format (FIT) this 2840 variable is used to get script subimage unit name. 2841 2842 autostart - if set to "yes", an image loaded using the "bootp", 2843 "rarpboot", "tftpboot" or "diskboot" commands will 2844 be automatically started (by internally calling 2845 "bootm") 2846 2847 If set to "no", a standalone image passed to the 2848 "bootm" command will be copied to the load address 2849 (and eventually uncompressed), but NOT be started. 2850 This can be used to load and uncompress arbitrary 2851 data. 2852 2853 i2cfast - (PPC405GP|PPC405EP only) 2854 if set to 'y' configures Linux I2C driver for fast 2855 mode (400kHZ). This environment variable is used in 2856 initialization code. So, for changes to be effective 2857 it must be saved and board must be reset. 2858 2859 initrd_high - restrict positioning of initrd images: 2860 If this variable is not set, initrd images will be 2861 copied to the highest possible address in RAM; this 2862 is usually what you want since it allows for 2863 maximum initrd size. If for some reason you want to 2864 make sure that the initrd image is loaded below the 2865 CFG_BOOTMAPSZ limit, you can set this environment 2866 variable to a value of "no" or "off" or "0". 2867 Alternatively, you can set it to a maximum upper 2868 address to use (U-Boot will still check that it 2869 does not overwrite the U-Boot stack and data). 2870 2871 For instance, when you have a system with 16 MB 2872 RAM, and want to reserve 4 MB from use by Linux, 2873 you can do this by adding "mem=12M" to the value of 2874 the "bootargs" variable. However, now you must make 2875 sure that the initrd image is placed in the first 2876 12 MB as well - this can be done with 2877 2878 setenv initrd_high 00c00000 2879 2880 If you set initrd_high to 0xFFFFFFFF, this is an 2881 indication to U-Boot that all addresses are legal 2882 for the Linux kernel, including addresses in flash 2883 memory. In this case U-Boot will NOT COPY the 2884 ramdisk at all. This may be useful to reduce the 2885 boot time on your system, but requires that this 2886 feature is supported by your Linux kernel. 2887 2888 ipaddr - IP address; needed for tftpboot command 2889 2890 loadaddr - Default load address for commands like "bootp", 2891 "rarpboot", "tftpboot", "loadb" or "diskboot" 2892 2893 loads_echo - see CONFIG_LOADS_ECHO 2894 2895 serverip - TFTP server IP address; needed for tftpboot command 2896 2897 bootretry - see CONFIG_BOOT_RETRY_TIME 2898 2899 bootdelaykey - see CONFIG_AUTOBOOT_DELAY_STR 2900 2901 bootstopkey - see CONFIG_AUTOBOOT_STOP_STR 2902 2903 ethprime - When CONFIG_NET_MULTI is enabled controls which 2904 interface is used first. 2905 2906 ethact - When CONFIG_NET_MULTI is enabled controls which 2907 interface is currently active. For example you 2908 can do the following 2909 2910 => setenv ethact FEC ETHERNET 2911 => ping 192.168.0.1 # traffic sent on FEC ETHERNET 2912 => setenv ethact SCC ETHERNET 2913 => ping 10.0.0.1 # traffic sent on SCC ETHERNET 2914 2915 ethrotate - When set to "no" U-Boot does not go through all 2916 available network interfaces. 2917 It just stays at the currently selected interface. 2918 2919 netretry - When set to "no" each network operation will 2920 either succeed or fail without retrying. 2921 When set to "once" the network operation will 2922 fail when all the available network interfaces 2923 are tried once without success. 2924 Useful on scripts which control the retry operation 2925 themselves. 2926 2927 npe_ucode - see CONFIG_IXP4XX_NPE_EXT_UCOD 2928 if set load address for the NPE microcode 2929 2930 tftpsrcport - If this is set, the value is used for TFTP's 2931 UDP source port. 2932 2933 tftpdstport - If this is set, the value is used for TFTP's UDP 2934 destination port instead of the Well Know Port 69. 2935 2936 vlan - When set to a value < 4095 the traffic over 2937 Ethernet is encapsulated/received over 802.1q 2938 VLAN tagged frames. 2939 2940The following environment variables may be used and automatically 2941updated by the network boot commands ("bootp" and "rarpboot"), 2942depending the information provided by your boot server: 2943 2944 bootfile - see above 2945 dnsip - IP address of your Domain Name Server 2946 dnsip2 - IP address of your secondary Domain Name Server 2947 gatewayip - IP address of the Gateway (Router) to use 2948 hostname - Target hostname 2949 ipaddr - see above 2950 netmask - Subnet Mask 2951 rootpath - Pathname of the root filesystem on the NFS server 2952 serverip - see above 2953 2954 2955There are two special Environment Variables: 2956 2957 serial# - contains hardware identification information such 2958 as type string and/or serial number 2959 ethaddr - Ethernet address 2960 2961These variables can be set only once (usually during manufacturing of 2962the board). U-Boot refuses to delete or overwrite these variables 2963once they have been set once. 2964 2965 2966Further special Environment Variables: 2967 2968 ver - Contains the U-Boot version string as printed 2969 with the "version" command. This variable is 2970 readonly (see CONFIG_VERSION_VARIABLE). 2971 2972 2973Please note that changes to some configuration parameters may take 2974only effect after the next boot (yes, that's just like Windoze :-). 2975 2976 2977Command Line Parsing: 2978===================== 2979 2980There are two different command line parsers available with U-Boot: 2981the old "simple" one, and the much more powerful "hush" shell: 2982 2983Old, simple command line parser: 2984-------------------------------- 2985 2986- supports environment variables (through setenv / saveenv commands) 2987- several commands on one line, separated by ';' 2988- variable substitution using "... ${name} ..." syntax 2989- special characters ('$', ';') can be escaped by prefixing with '\', 2990 for example: 2991 setenv bootcmd bootm \${address} 2992- You can also escape text by enclosing in single apostrophes, for example: 2993 setenv addip 'setenv bootargs $bootargs ip=$ipaddr:$serverip:$gatewayip:$netmask:$hostname::off' 2994 2995Hush shell: 2996----------- 2997 2998- similar to Bourne shell, with control structures like 2999 if...then...else...fi, for...do...done; while...do...done, 3000 until...do...done, ... 3001- supports environment ("global") variables (through setenv / saveenv 3002 commands) and local shell variables (through standard shell syntax 3003 "name=value"); only environment variables can be used with "run" 3004 command 3005 3006General rules: 3007-------------- 3008 3009(1) If a command line (or an environment variable executed by a "run" 3010 command) contains several commands separated by semicolon, and 3011 one of these commands fails, then the remaining commands will be 3012 executed anyway. 3013 3014(2) If you execute several variables with one call to run (i. e. 3015 calling run with a list of variables as arguments), any failing 3016 command will cause "run" to terminate, i. e. the remaining 3017 variables are not executed. 3018 3019Note for Redundant Ethernet Interfaces: 3020======================================= 3021 3022Some boards come with redundant Ethernet interfaces; U-Boot supports 3023such configurations and is capable of automatic selection of a 3024"working" interface when needed. MAC assignment works as follows: 3025 3026Network interfaces are numbered eth0, eth1, eth2, ... Corresponding 3027MAC addresses can be stored in the environment as "ethaddr" (=>eth0), 3028"eth1addr" (=>eth1), "eth2addr", ... 3029 3030If the network interface stores some valid MAC address (for instance 3031in SROM), this is used as default address if there is NO correspon- 3032ding setting in the environment; if the corresponding environment 3033variable is set, this overrides the settings in the card; that means: 3034 3035o If the SROM has a valid MAC address, and there is no address in the 3036 environment, the SROM's address is used. 3037 3038o If there is no valid address in the SROM, and a definition in the 3039 environment exists, then the value from the environment variable is 3040 used. 3041 3042o If both the SROM and the environment contain a MAC address, and 3043 both addresses are the same, this MAC address is used. 3044 3045o If both the SROM and the environment contain a MAC address, and the 3046 addresses differ, the value from the environment is used and a 3047 warning is printed. 3048 3049o If neither SROM nor the environment contain a MAC address, an error 3050 is raised. 3051 3052 3053Image Formats: 3054============== 3055 3056U-Boot is capable of booting (and performing other auxiliary operations on) 3057images in two formats: 3058 3059New uImage format (FIT) 3060----------------------- 3061 3062Flexible and powerful format based on Flattened Image Tree -- FIT (similar 3063to Flattened Device Tree). It allows the use of images with multiple 3064components (several kernels, ramdisks, etc.), with contents protected by 3065SHA1, MD5 or CRC32. More details are found in the doc/uImage.FIT directory. 3066 3067 3068Old uImage format 3069----------------- 3070 3071Old image format is based on binary files which can be basically anything, 3072preceded by a special header; see the definitions in include/image.h for 3073details; basically, the header defines the following image properties: 3074 3075* Target Operating System (Provisions for OpenBSD, NetBSD, FreeBSD, 3076 4.4BSD, Linux, SVR4, Esix, Solaris, Irix, SCO, Dell, NCR, VxWorks, 3077 LynxOS, pSOS, QNX, RTEMS, INTEGRITY; 3078 Currently supported: Linux, NetBSD, VxWorks, QNX, RTEMS, LynxOS, 3079 INTEGRITY). 3080* Target CPU Architecture (Provisions for Alpha, ARM, AVR32, Intel x86, 3081 IA64, MIPS, NIOS, PowerPC, IBM S390, SuperH, Sparc, Sparc 64 Bit; 3082 Currently supported: ARM, AVR32, Intel x86, MIPS, NIOS, PowerPC). 3083* Compression Type (uncompressed, gzip, bzip2) 3084* Load Address 3085* Entry Point 3086* Image Name 3087* Image Timestamp 3088 3089The header is marked by a special Magic Number, and both the header 3090and the data portions of the image are secured against corruption by 3091CRC32 checksums. 3092 3093 3094Linux Support: 3095============== 3096 3097Although U-Boot should support any OS or standalone application 3098easily, the main focus has always been on Linux during the design of 3099U-Boot. 3100 3101U-Boot includes many features that so far have been part of some 3102special "boot loader" code within the Linux kernel. Also, any 3103"initrd" images to be used are no longer part of one big Linux image; 3104instead, kernel and "initrd" are separate images. This implementation 3105serves several purposes: 3106 3107- the same features can be used for other OS or standalone 3108 applications (for instance: using compressed images to reduce the 3109 Flash memory footprint) 3110 3111- it becomes much easier to port new Linux kernel versions because 3112 lots of low-level, hardware dependent stuff are done by U-Boot 3113 3114- the same Linux kernel image can now be used with different "initrd" 3115 images; of course this also means that different kernel images can 3116 be run with the same "initrd". This makes testing easier (you don't 3117 have to build a new "zImage.initrd" Linux image when you just 3118 change a file in your "initrd"). Also, a field-upgrade of the 3119 software is easier now. 3120 3121 3122Linux HOWTO: 3123============ 3124 3125Porting Linux to U-Boot based systems: 3126--------------------------------------- 3127 3128U-Boot cannot save you from doing all the necessary modifications to 3129configure the Linux device drivers for use with your target hardware 3130(no, we don't intend to provide a full virtual machine interface to 3131Linux :-). 3132 3133But now you can ignore ALL boot loader code (in arch/ppc/mbxboot). 3134 3135Just make sure your machine specific header file (for instance 3136include/asm-ppc/tqm8xx.h) includes the same definition of the Board 3137Information structure as we define in include/asm-<arch>/u-boot.h, 3138and make sure that your definition of IMAP_ADDR uses the same value 3139as your U-Boot configuration in CFG_IMMR. 3140 3141 3142Configuring the Linux kernel: 3143----------------------------- 3144 3145No specific requirements for U-Boot. Make sure you have some root 3146device (initial ramdisk, NFS) for your target system. 3147 3148 3149Building a Linux Image: 3150----------------------- 3151 3152With U-Boot, "normal" build targets like "zImage" or "bzImage" are 3153not used. If you use recent kernel source, a new build target 3154"uImage" will exist which automatically builds an image usable by 3155U-Boot. Most older kernels also have support for a "pImage" target, 3156which was introduced for our predecessor project PPCBoot and uses a 3157100% compatible format. 3158 3159Example: 3160 3161 make TQM850L_config 3162 make oldconfig 3163 make dep 3164 make uImage 3165 3166The "uImage" build target uses a special tool (in 'tools/mkimage') to 3167encapsulate a compressed Linux kernel image with header information, 3168CRC32 checksum etc. for use with U-Boot. This is what we are doing: 3169 3170* build a standard "vmlinux" kernel image (in ELF binary format): 3171 3172* convert the kernel into a raw binary image: 3173 3174 ${CROSS_COMPILE}-objcopy -O binary \ 3175 -R .note -R .comment \ 3176 -S vmlinux linux.bin 3177 3178* compress the binary image: 3179 3180 gzip -9 linux.bin 3181 3182* package compressed binary image for U-Boot: 3183 3184 mkimage -A ppc -O linux -T kernel -C gzip \ 3185 -a 0 -e 0 -n "Linux Kernel Image" \ 3186 -d linux.bin.gz uImage 3187 3188 3189The "mkimage" tool can also be used to create ramdisk images for use 3190with U-Boot, either separated from the Linux kernel image, or 3191combined into one file. "mkimage" encapsulates the images with a 64 3192byte header containing information about target architecture, 3193operating system, image type, compression method, entry points, time 3194stamp, CRC32 checksums, etc. 3195 3196"mkimage" can be called in two ways: to verify existing images and 3197print the header information, or to build new images. 3198 3199In the first form (with "-l" option) mkimage lists the information 3200contained in the header of an existing U-Boot image; this includes 3201checksum verification: 3202 3203 tools/mkimage -l image 3204 -l ==> list image header information 3205 3206The second form (with "-d" option) is used to build a U-Boot image 3207from a "data file" which is used as image payload: 3208 3209 tools/mkimage -A arch -O os -T type -C comp -a addr -e ep \ 3210 -n name -d data_file image 3211 -A ==> set architecture to 'arch' 3212 -O ==> set operating system to 'os' 3213 -T ==> set image type to 'type' 3214 -C ==> set compression type 'comp' 3215 -a ==> set load address to 'addr' (hex) 3216 -e ==> set entry point to 'ep' (hex) 3217 -n ==> set image name to 'name' 3218 -d ==> use image data from 'datafile' 3219 3220Right now, all Linux kernels for PowerPC systems use the same load 3221address (0x00000000), but the entry point address depends on the 3222kernel version: 3223 3224- 2.2.x kernels have the entry point at 0x0000000C, 3225- 2.3.x and later kernels have the entry point at 0x00000000. 3226 3227So a typical call to build a U-Boot image would read: 3228 3229 -> tools/mkimage -n '2.4.4 kernel for TQM850L' \ 3230 > -A ppc -O linux -T kernel -C gzip -a 0 -e 0 \ 3231 > -d /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/ppc/coffboot/vmlinux.gz \ 3232 > examples/uImage.TQM850L 3233 Image Name: 2.4.4 kernel for TQM850L 3234 Created: Wed Jul 19 02:34:59 2000 3235 Image Type: PowerPC Linux Kernel Image (gzip compressed) 3236 Data Size: 335725 Bytes = 327.86 kB = 0.32 MB 3237 Load Address: 0x00000000 3238 Entry Point: 0x00000000 3239 3240To verify the contents of the image (or check for corruption): 3241 3242 -> tools/mkimage -l examples/uImage.TQM850L 3243 Image Name: 2.4.4 kernel for TQM850L 3244 Created: Wed Jul 19 02:34:59 2000 3245 Image Type: PowerPC Linux Kernel Image (gzip compressed) 3246 Data Size: 335725 Bytes = 327.86 kB = 0.32 MB 3247 Load Address: 0x00000000 3248 Entry Point: 0x00000000 3249 3250NOTE: for embedded systems where boot time is critical you can trade 3251speed for memory and install an UNCOMPRESSED image instead: this 3252needs more space in Flash, but boots much faster since it does not 3253need to be uncompressed: 3254 3255 -> gunzip /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/ppc/coffboot/vmlinux.gz 3256 -> tools/mkimage -n '2.4.4 kernel for TQM850L' \ 3257 > -A ppc -O linux -T kernel -C none -a 0 -e 0 \ 3258 > -d /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/ppc/coffboot/vmlinux \ 3259 > examples/uImage.TQM850L-uncompressed 3260 Image Name: 2.4.4 kernel for TQM850L 3261 Created: Wed Jul 19 02:34:59 2000 3262 Image Type: PowerPC Linux Kernel Image (uncompressed) 3263 Data Size: 792160 Bytes = 773.59 kB = 0.76 MB 3264 Load Address: 0x00000000 3265 Entry Point: 0x00000000 3266 3267 3268Similar you can build U-Boot images from a 'ramdisk.image.gz' file 3269when your kernel is intended to use an initial ramdisk: 3270 3271 -> tools/mkimage -n 'Simple Ramdisk Image' \ 3272 > -A ppc -O linux -T ramdisk -C gzip \ 3273 > -d /LinuxPPC/images/SIMPLE-ramdisk.image.gz examples/simple-initrd 3274 Image Name: Simple Ramdisk Image 3275 Created: Wed Jan 12 14:01:50 2000 3276 Image Type: PowerPC Linux RAMDisk Image (gzip compressed) 3277 Data Size: 566530 Bytes = 553.25 kB = 0.54 MB 3278 Load Address: 0x00000000 3279 Entry Point: 0x00000000 3280 3281 3282Installing a Linux Image: 3283------------------------- 3284 3285To downloading a U-Boot image over the serial (console) interface, 3286you must convert the image to S-Record format: 3287 3288 objcopy -I binary -O srec examples/image examples/image.srec 3289 3290The 'objcopy' does not understand the information in the U-Boot 3291image header, so the resulting S-Record file will be relative to 3292address 0x00000000. To load it to a given address, you need to 3293specify the target address as 'offset' parameter with the 'loads' 3294command. 3295 3296Example: install the image to address 0x40100000 (which on the 3297TQM8xxL is in the first Flash bank): 3298 3299 => erase 40100000 401FFFFF 3300 3301 .......... done 3302 Erased 8 sectors 3303 3304 => loads 40100000 3305 ## Ready for S-Record download ... 3306 ~>examples/image.srec 3307 1 2 3 4 5 6 7 8 9 10 11 12 13 ... 3308 ... 3309 15989 15990 15991 15992 3310 [file transfer complete] 3311 [connected] 3312 ## Start Addr = 0x00000000 3313 3314 3315You can check the success of the download using the 'iminfo' command; 3316this includes a checksum verification so you can be sure no data 3317corruption happened: 3318 3319 => imi 40100000 3320 3321 ## Checking Image at 40100000 ... 3322 Image Name: 2.2.13 for initrd on TQM850L 3323 Image Type: PowerPC Linux Kernel Image (gzip compressed) 3324 Data Size: 335725 Bytes = 327 kB = 0 MB 3325 Load Address: 00000000 3326 Entry Point: 0000000c 3327 Verifying Checksum ... OK 3328 3329 3330Boot Linux: 3331----------- 3332 3333The "bootm" command is used to boot an application that is stored in 3334memory (RAM or Flash). In case of a Linux kernel image, the contents 3335of the "bootargs" environment variable is passed to the kernel as 3336parameters. You can check and modify this variable using the 3337"printenv" and "setenv" commands: 3338 3339 3340 => printenv bootargs 3341 bootargs=root=/dev/ram 3342 3343 => setenv bootargs root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2 3344 3345 => printenv bootargs 3346 bootargs=root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2 3347 3348 => bootm 40020000 3349 ## Booting Linux kernel at 40020000 ... 3350 Image Name: 2.2.13 for NFS on TQM850L 3351 Image Type: PowerPC Linux Kernel Image (gzip compressed) 3352 Data Size: 381681 Bytes = 372 kB = 0 MB 3353 Load Address: 00000000 3354 Entry Point: 0000000c 3355 Verifying Checksum ... OK 3356 Uncompressing Kernel Image ... OK 3357 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 3358 Boot arguments: root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2 3359 time_init: decrementer frequency = 187500000/60 3360 Calibrating delay loop... 49.77 BogoMIPS 3361 Memory: 15208k available (700k kernel code, 444k data, 32k init) [c0000000,c1000000] 3362 ... 3363 3364If you want to boot a Linux kernel with initial RAM disk, you pass 3365the memory addresses of both the kernel and the initrd image (PPBCOOT 3366format!) to the "bootm" command: 3367 3368 => imi 40100000 40200000 3369 3370 ## Checking Image at 40100000 ... 3371 Image Name: 2.2.13 for initrd on TQM850L 3372 Image Type: PowerPC Linux Kernel Image (gzip compressed) 3373 Data Size: 335725 Bytes = 327 kB = 0 MB 3374 Load Address: 00000000 3375 Entry Point: 0000000c 3376 Verifying Checksum ... OK 3377 3378 ## Checking Image at 40200000 ... 3379 Image Name: Simple Ramdisk Image 3380 Image Type: PowerPC Linux RAMDisk Image (gzip compressed) 3381 Data Size: 566530 Bytes = 553 kB = 0 MB 3382 Load Address: 00000000 3383 Entry Point: 00000000 3384 Verifying Checksum ... OK 3385 3386 => bootm 40100000 40200000 3387 ## Booting Linux kernel at 40100000 ... 3388 Image Name: 2.2.13 for initrd on TQM850L 3389 Image Type: PowerPC Linux Kernel Image (gzip compressed) 3390 Data Size: 335725 Bytes = 327 kB = 0 MB 3391 Load Address: 00000000 3392 Entry Point: 0000000c 3393 Verifying Checksum ... OK 3394 Uncompressing Kernel Image ... OK 3395 ## Loading RAMDisk Image at 40200000 ... 3396 Image Name: Simple Ramdisk Image 3397 Image Type: PowerPC Linux RAMDisk Image (gzip compressed) 3398 Data Size: 566530 Bytes = 553 kB = 0 MB 3399 Load Address: 00000000 3400 Entry Point: 00000000 3401 Verifying Checksum ... OK 3402 Loading Ramdisk ... OK 3403 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 3404 Boot arguments: root=/dev/ram 3405 time_init: decrementer frequency = 187500000/60 3406 Calibrating delay loop... 49.77 BogoMIPS 3407 ... 3408 RAMDISK: Compressed image found at block 0 3409 VFS: Mounted root (ext2 filesystem). 3410 3411 bash# 3412 3413Boot Linux and pass a flat device tree: 3414----------- 3415 3416First, U-Boot must be compiled with the appropriate defines. See the section 3417titled "Linux Kernel Interface" above for a more in depth explanation. The 3418following is an example of how to start a kernel and pass an updated 3419flat device tree: 3420 3421=> print oftaddr 3422oftaddr=0x300000 3423=> print oft 3424oft=oftrees/mpc8540ads.dtb 3425=> tftp $oftaddr $oft 3426Speed: 1000, full duplex 3427Using TSEC0 device 3428TFTP from server 192.168.1.1; our IP address is 192.168.1.101 3429Filename 'oftrees/mpc8540ads.dtb'. 3430Load address: 0x300000 3431Loading: # 3432done 3433Bytes transferred = 4106 (100a hex) 3434=> tftp $loadaddr $bootfile 3435Speed: 1000, full duplex 3436Using TSEC0 device 3437TFTP from server 192.168.1.1; our IP address is 192.168.1.2 3438Filename 'uImage'. 3439Load address: 0x200000 3440Loading:############ 3441done 3442Bytes transferred = 1029407 (fb51f hex) 3443=> print loadaddr 3444loadaddr=200000 3445=> print oftaddr 3446oftaddr=0x300000 3447=> bootm $loadaddr - $oftaddr 3448## Booting image at 00200000 ... 3449 Image Name: Linux-2.6.17-dirty 3450 Image Type: PowerPC Linux Kernel Image (gzip compressed) 3451 Data Size: 1029343 Bytes = 1005.2 kB 3452 Load Address: 00000000 3453 Entry Point: 00000000 3454 Verifying Checksum ... OK 3455 Uncompressing Kernel Image ... OK 3456Booting using flat device tree at 0x300000 3457Using MPC85xx ADS machine description 3458Memory CAM mapping: CAM0=256Mb, CAM1=256Mb, CAM2=0Mb residual: 0Mb 3459[snip] 3460 3461 3462More About U-Boot Image Types: 3463------------------------------ 3464 3465U-Boot supports the following image types: 3466 3467 "Standalone Programs" are directly runnable in the environment 3468 provided by U-Boot; it is expected that (if they behave 3469 well) you can continue to work in U-Boot after return from 3470 the Standalone Program. 3471 "OS Kernel Images" are usually images of some Embedded OS which 3472 will take over control completely. Usually these programs 3473 will install their own set of exception handlers, device 3474 drivers, set up the MMU, etc. - this means, that you cannot 3475 expect to re-enter U-Boot except by resetting the CPU. 3476 "RAMDisk Images" are more or less just data blocks, and their 3477 parameters (address, size) are passed to an OS kernel that is 3478 being started. 3479 "Multi-File Images" contain several images, typically an OS 3480 (Linux) kernel image and one or more data images like 3481 RAMDisks. This construct is useful for instance when you want 3482 to boot over the network using BOOTP etc., where the boot 3483 server provides just a single image file, but you want to get 3484 for instance an OS kernel and a RAMDisk image. 3485 3486 "Multi-File Images" start with a list of image sizes, each 3487 image size (in bytes) specified by an "uint32_t" in network 3488 byte order. This list is terminated by an "(uint32_t)0". 3489 Immediately after the terminating 0 follow the images, one by 3490 one, all aligned on "uint32_t" boundaries (size rounded up to 3491 a multiple of 4 bytes). 3492 3493 "Firmware Images" are binary images containing firmware (like 3494 U-Boot or FPGA images) which usually will be programmed to 3495 flash memory. 3496 3497 "Script files" are command sequences that will be executed by 3498 U-Boot's command interpreter; this feature is especially 3499 useful when you configure U-Boot to use a real shell (hush) 3500 as command interpreter. 3501 3502 3503Standalone HOWTO: 3504================= 3505 3506One of the features of U-Boot is that you can dynamically load and 3507run "standalone" applications, which can use some resources of 3508U-Boot like console I/O functions or interrupt services. 3509 3510Two simple examples are included with the sources: 3511 3512"Hello World" Demo: 3513------------------- 3514 3515'examples/hello_world.c' contains a small "Hello World" Demo 3516application; it is automatically compiled when you build U-Boot. 3517It's configured to run at address 0x00040004, so you can play with it 3518like that: 3519 3520 => loads 3521 ## Ready for S-Record download ... 3522 ~>examples/hello_world.srec 3523 1 2 3 4 5 6 7 8 9 10 11 ... 3524 [file transfer complete] 3525 [connected] 3526 ## Start Addr = 0x00040004 3527 3528 => go 40004 Hello World! This is a test. 3529 ## Starting application at 0x00040004 ... 3530 Hello World 3531 argc = 7 3532 argv[0] = "40004" 3533 argv[1] = "Hello" 3534 argv[2] = "World!" 3535 argv[3] = "This" 3536 argv[4] = "is" 3537 argv[5] = "a" 3538 argv[6] = "test." 3539 argv[7] = "<NULL>" 3540 Hit any key to exit ... 3541 3542 ## Application terminated, rc = 0x0 3543 3544Another example, which demonstrates how to register a CPM interrupt 3545handler with the U-Boot code, can be found in 'examples/timer.c'. 3546Here, a CPM timer is set up to generate an interrupt every second. 3547The interrupt service routine is trivial, just printing a '.' 3548character, but this is just a demo program. The application can be 3549controlled by the following keys: 3550 3551 ? - print current values og the CPM Timer registers 3552 b - enable interrupts and start timer 3553 e - stop timer and disable interrupts 3554 q - quit application 3555 3556 => loads 3557 ## Ready for S-Record download ... 3558 ~>examples/timer.srec 3559 1 2 3 4 5 6 7 8 9 10 11 ... 3560 [file transfer complete] 3561 [connected] 3562 ## Start Addr = 0x00040004 3563 3564 => go 40004 3565 ## Starting application at 0x00040004 ... 3566 TIMERS=0xfff00980 3567 Using timer 1 3568 tgcr @ 0xfff00980, tmr @ 0xfff00990, trr @ 0xfff00994, tcr @ 0xfff00998, tcn @ 0xfff0099c, ter @ 0xfff009b0 3569 3570Hit 'b': 3571 [q, b, e, ?] Set interval 1000000 us 3572 Enabling timer 3573Hit '?': 3574 [q, b, e, ?] ........ 3575 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0xef6, ter=0x0 3576Hit '?': 3577 [q, b, e, ?] . 3578 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x2ad4, ter=0x0 3579Hit '?': 3580 [q, b, e, ?] . 3581 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x1efc, ter=0x0 3582Hit '?': 3583 [q, b, e, ?] . 3584 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x169d, ter=0x0 3585Hit 'e': 3586 [q, b, e, ?] ...Stopping timer 3587Hit 'q': 3588 [q, b, e, ?] ## Application terminated, rc = 0x0 3589 3590 3591Minicom warning: 3592================ 3593 3594Over time, many people have reported problems when trying to use the 3595"minicom" terminal emulation program for serial download. I (wd) 3596consider minicom to be broken, and recommend not to use it. Under 3597Unix, I recommend to use C-Kermit for general purpose use (and 3598especially for kermit binary protocol download ("loadb" command), and 3599use "cu" for S-Record download ("loads" command). 3600 3601Nevertheless, if you absolutely want to use it try adding this 3602configuration to your "File transfer protocols" section: 3603 3604 Name Program Name U/D FullScr IO-Red. Multi 3605 X kermit /usr/bin/kermit -i -l %l -s Y U Y N N 3606 Y kermit /usr/bin/kermit -i -l %l -r N D Y N N 3607 3608 3609NetBSD Notes: 3610============= 3611 3612Starting at version 0.9.2, U-Boot supports NetBSD both as host 3613(build U-Boot) and target system (boots NetBSD/mpc8xx). 3614 3615Building requires a cross environment; it is known to work on 3616NetBSD/i386 with the cross-powerpc-netbsd-1.3 package (you will also 3617need gmake since the Makefiles are not compatible with BSD make). 3618Note that the cross-powerpc package does not install include files; 3619attempting to build U-Boot will fail because <machine/ansi.h> is 3620missing. This file has to be installed and patched manually: 3621 3622 # cd /usr/pkg/cross/powerpc-netbsd/include 3623 # mkdir powerpc 3624 # ln -s powerpc machine 3625 # cp /usr/src/sys/arch/powerpc/include/ansi.h powerpc/ansi.h 3626 # ${EDIT} powerpc/ansi.h ## must remove __va_list, _BSD_VA_LIST 3627 3628Native builds *don't* work due to incompatibilities between native 3629and U-Boot include files. 3630 3631Booting assumes that (the first part of) the image booted is a 3632stage-2 loader which in turn loads and then invokes the kernel 3633proper. Loader sources will eventually appear in the NetBSD source 3634tree (probably in sys/arc/mpc8xx/stand/u-boot_stage2/); in the 3635meantime, see ftp://ftp.denx.de/pub/u-boot/ppcboot_stage2.tar.gz 3636 3637 3638Implementation Internals: 3639========================= 3640 3641The following is not intended to be a complete description of every 3642implementation detail. However, it should help to understand the 3643inner workings of U-Boot and make it easier to port it to custom 3644hardware. 3645 3646 3647Initial Stack, Global Data: 3648--------------------------- 3649 3650The implementation of U-Boot is complicated by the fact that U-Boot 3651starts running out of ROM (flash memory), usually without access to 3652system RAM (because the memory controller is not initialized yet). 3653This means that we don't have writable Data or BSS segments, and BSS 3654is not initialized as zero. To be able to get a C environment working 3655at all, we have to allocate at least a minimal stack. Implementation 3656options for this are defined and restricted by the CPU used: Some CPU 3657models provide on-chip memory (like the IMMR area on MPC8xx and 3658MPC826x processors), on others (parts of) the data cache can be 3659locked as (mis-) used as memory, etc. 3660 3661 Chris Hallinan posted a good summary of these issues to the 3662 u-boot-users mailing list: 3663 3664 Subject: RE: [U-Boot-Users] RE: More On Memory Bank x (nothingness)? 3665 From: "Chris Hallinan" <clh@net1plus.com> 3666 Date: Mon, 10 Feb 2003 16:43:46 -0500 (22:43 MET) 3667 ... 3668 3669 Correct me if I'm wrong, folks, but the way I understand it 3670 is this: Using DCACHE as initial RAM for Stack, etc, does not 3671 require any physical RAM backing up the cache. The cleverness 3672 is that the cache is being used as a temporary supply of 3673 necessary storage before the SDRAM controller is setup. It's 3674 beyond the scope of this list to explain the details, but you 3675 can see how this works by studying the cache architecture and 3676 operation in the architecture and processor-specific manuals. 3677 3678 OCM is On Chip Memory, which I believe the 405GP has 4K. It 3679 is another option for the system designer to use as an 3680 initial stack/RAM area prior to SDRAM being available. Either 3681 option should work for you. Using CS 4 should be fine if your 3682 board designers haven't used it for something that would 3683 cause you grief during the initial boot! It is frequently not 3684 used. 3685 3686 CFG_INIT_RAM_ADDR should be somewhere that won't interfere 3687 with your processor/board/system design. The default value 3688 you will find in any recent u-boot distribution in 3689 walnut.h should work for you. I'd set it to a value larger 3690 than your SDRAM module. If you have a 64MB SDRAM module, set 3691 it above 400_0000. Just make sure your board has no resources 3692 that are supposed to respond to that address! That code in 3693 start.S has been around a while and should work as is when 3694 you get the config right. 3695 3696 -Chris Hallinan 3697 DS4.COM, Inc. 3698 3699It is essential to remember this, since it has some impact on the C 3700code for the initialization procedures: 3701 3702* Initialized global data (data segment) is read-only. Do not attempt 3703 to write it. 3704 3705* Do not use any uninitialized global data (or implicitely initialized 3706 as zero data - BSS segment) at all - this is undefined, initiali- 3707 zation is performed later (when relocating to RAM). 3708 3709* Stack space is very limited. Avoid big data buffers or things like 3710 that. 3711 3712Having only the stack as writable memory limits means we cannot use 3713normal global data to share information beween the code. But it 3714turned out that the implementation of U-Boot can be greatly 3715simplified by making a global data structure (gd_t) available to all 3716functions. We could pass a pointer to this data as argument to _all_ 3717functions, but this would bloat the code. Instead we use a feature of 3718the GCC compiler (Global Register Variables) to share the data: we 3719place a pointer (gd) to the global data into a register which we 3720reserve for this purpose. 3721 3722When choosing a register for such a purpose we are restricted by the 3723relevant (E)ABI specifications for the current architecture, and by 3724GCC's implementation. 3725 3726For PowerPC, the following registers have specific use: 3727 R1: stack pointer 3728 R2: reserved for system use 3729 R3-R4: parameter passing and return values 3730 R5-R10: parameter passing 3731 R13: small data area pointer 3732 R30: GOT pointer 3733 R31: frame pointer 3734 3735 (U-Boot also uses R14 as internal GOT pointer.) 3736 3737 ==> U-Boot will use R2 to hold a pointer to the global data 3738 3739 Note: on PPC, we could use a static initializer (since the 3740 address of the global data structure is known at compile time), 3741 but it turned out that reserving a register results in somewhat 3742 smaller code - although the code savings are not that big (on 3743 average for all boards 752 bytes for the whole U-Boot image, 3744 624 text + 127 data). 3745 3746On Blackfin, the normal C ABI (except for P5) is followed as documented here: 3747 http://docs.blackfin.uclinux.org/doku.php?id=application_binary_interface 3748 3749 ==> U-Boot will use P5 to hold a pointer to the global data 3750 3751On ARM, the following registers are used: 3752 3753 R0: function argument word/integer result 3754 R1-R3: function argument word 3755 R9: GOT pointer 3756 R10: stack limit (used only if stack checking if enabled) 3757 R11: argument (frame) pointer 3758 R12: temporary workspace 3759 R13: stack pointer 3760 R14: link register 3761 R15: program counter 3762 3763 ==> U-Boot will use R8 to hold a pointer to the global data 3764 3765NOTE: DECLARE_GLOBAL_DATA_PTR must be used with file-global scope, 3766or current versions of GCC may "optimize" the code too much. 3767 3768Memory Management: 3769------------------ 3770 3771U-Boot runs in system state and uses physical addresses, i.e. the 3772MMU is not used either for address mapping nor for memory protection. 3773 3774The available memory is mapped to fixed addresses using the memory 3775controller. In this process, a contiguous block is formed for each 3776memory type (Flash, SDRAM, SRAM), even when it consists of several 3777physical memory banks. 3778 3779U-Boot is installed in the first 128 kB of the first Flash bank (on 3780TQM8xxL modules this is the range 0x40000000 ... 0x4001FFFF). After 3781booting and sizing and initializing DRAM, the code relocates itself 3782to the upper end of DRAM. Immediately below the U-Boot code some 3783memory is reserved for use by malloc() [see CFG_MALLOC_LEN 3784configuration setting]. Below that, a structure with global Board 3785Info data is placed, followed by the stack (growing downward). 3786 3787Additionally, some exception handler code is copied to the low 8 kB 3788of DRAM (0x00000000 ... 0x00001FFF). 3789 3790So a typical memory configuration with 16 MB of DRAM could look like 3791this: 3792 3793 0x0000 0000 Exception Vector code 3794 : 3795 0x0000 1FFF 3796 0x0000 2000 Free for Application Use 3797 : 3798 : 3799 3800 : 3801 : 3802 0x00FB FF20 Monitor Stack (Growing downward) 3803 0x00FB FFAC Board Info Data and permanent copy of global data 3804 0x00FC 0000 Malloc Arena 3805 : 3806 0x00FD FFFF 3807 0x00FE 0000 RAM Copy of Monitor Code 3808 ... eventually: LCD or video framebuffer 3809 ... eventually: pRAM (Protected RAM - unchanged by reset) 3810 0x00FF FFFF [End of RAM] 3811 3812 3813System Initialization: 3814---------------------- 3815 3816In the reset configuration, U-Boot starts at the reset entry point 3817(on most PowerPC systems at address 0x00000100). Because of the reset 3818configuration for CS0# this is a mirror of the onboard Flash memory. 3819To be able to re-map memory U-Boot then jumps to its link address. 3820To be able to implement the initialization code in C, a (small!) 3821initial stack is set up in the internal Dual Ported RAM (in case CPUs 3822which provide such a feature like MPC8xx or MPC8260), or in a locked 3823part of the data cache. After that, U-Boot initializes the CPU core, 3824the caches and the SIU. 3825 3826Next, all (potentially) available memory banks are mapped using a 3827preliminary mapping. For example, we put them on 512 MB boundaries 3828(multiples of 0x20000000: SDRAM on 0x00000000 and 0x20000000, Flash 3829on 0x40000000 and 0x60000000, SRAM on 0x80000000). Then UPM A is 3830programmed for SDRAM access. Using the temporary configuration, a 3831simple memory test is run that determines the size of the SDRAM 3832banks. 3833 3834When there is more than one SDRAM bank, and the banks are of 3835different size, the largest is mapped first. For equal size, the first 3836bank (CS2#) is mapped first. The first mapping is always for address 38370x00000000, with any additional banks following immediately to create 3838contiguous memory starting from 0. 3839 3840Then, the monitor installs itself at the upper end of the SDRAM area 3841and allocates memory for use by malloc() and for the global Board 3842Info data; also, the exception vector code is copied to the low RAM 3843pages, and the final stack is set up. 3844 3845Only after this relocation will you have a "normal" C environment; 3846until that you are restricted in several ways, mostly because you are 3847running from ROM, and because the code will have to be relocated to a 3848new address in RAM. 3849 3850 3851U-Boot Porting Guide: 3852---------------------- 3853 3854[Based on messages by Jerry Van Baren in the U-Boot-Users mailing 3855list, October 2002] 3856 3857 3858int main (int argc, char *argv[]) 3859{ 3860 sighandler_t no_more_time; 3861 3862 signal (SIGALRM, no_more_time); 3863 alarm (PROJECT_DEADLINE - toSec (3 * WEEK)); 3864 3865 if (available_money > available_manpower) { 3866 pay consultant to port U-Boot; 3867 return 0; 3868 } 3869 3870 Download latest U-Boot source; 3871 3872 Subscribe to u-boot-users mailing list; 3873 3874 if (clueless) { 3875 email ("Hi, I am new to U-Boot, how do I get started?"); 3876 } 3877 3878 while (learning) { 3879 Read the README file in the top level directory; 3880 Read http://www.denx.de/twiki/bin/view/DULG/Manual ; 3881 Read the source, Luke; 3882 } 3883 3884 if (available_money > toLocalCurrency ($2500)) { 3885 Buy a BDI2000; 3886 } else { 3887 Add a lot of aggravation and time; 3888 } 3889 3890 Create your own board support subdirectory; 3891 3892 Create your own board config file; 3893 3894 while (!running) { 3895 do { 3896 Add / modify source code; 3897 } until (compiles); 3898 Debug; 3899 if (clueless) 3900 email ("Hi, I am having problems..."); 3901 } 3902 Send patch file to Wolfgang; 3903 3904 return 0; 3905} 3906 3907void no_more_time (int sig) 3908{ 3909 hire_a_guru(); 3910} 3911 3912 3913Coding Standards: 3914----------------- 3915 3916All contributions to U-Boot should conform to the Linux kernel 3917coding style; see the file "Documentation/CodingStyle" and the script 3918"scripts/Lindent" in your Linux kernel source directory. In sources 3919originating from U-Boot a style corresponding to "Lindent -pcs" (adding 3920spaces before parameters to function calls) is actually used. 3921 3922Source files originating from a different project (for example the 3923MTD subsystem) are generally exempt from these guidelines and are not 3924reformated to ease subsequent migration to newer versions of those 3925sources. 3926 3927Please note that U-Boot is implemented in C (and to some small parts in 3928Assembler); no C++ is used, so please do not use C++ style comments (//) 3929in your code. 3930 3931Please also stick to the following formatting rules: 3932- remove any trailing white space 3933- use TAB characters for indentation, not spaces 3934- make sure NOT to use DOS '\r\n' line feeds 3935- do not add more than 2 empty lines to source files 3936- do not add trailing empty lines to source files 3937 3938Submissions which do not conform to the standards may be returned 3939with a request to reformat the changes. 3940 3941 3942Submitting Patches: 3943------------------- 3944 3945Since the number of patches for U-Boot is growing, we need to 3946establish some rules. Submissions which do not conform to these rules 3947may be rejected, even when they contain important and valuable stuff. 3948 3949Patches shall be sent to the u-boot-users mailing list. 3950 3951Please see http://www.denx.de/wiki/U-Boot/Patches for details. 3952 3953When you send a patch, please include the following information with 3954it: 3955 3956* For bug fixes: a description of the bug and how your patch fixes 3957 this bug. Please try to include a way of demonstrating that the 3958 patch actually fixes something. 3959 3960* For new features: a description of the feature and your 3961 implementation. 3962 3963* A CHANGELOG entry as plaintext (separate from the patch) 3964 3965* For major contributions, your entry to the CREDITS file 3966 3967* When you add support for a new board, don't forget to add this 3968 board to the MAKEALL script, too. 3969 3970* If your patch adds new configuration options, don't forget to 3971 document these in the README file. 3972 3973* The patch itself. If you are using git (which is *strongly* 3974 recommended) you can easily generate the patch using the 3975 "git-format-patch". If you then use "git-send-email" to send it to 3976 the U-Boot mailing list, you will avoid most of the common problems 3977 with some other mail clients. 3978 3979 If you cannot use git, use "diff -purN OLD NEW". If your version of 3980 diff does not support these options, then get the latest version of 3981 GNU diff. 3982 3983 The current directory when running this command shall be the parent 3984 directory of the U-Boot source tree (i. e. please make sure that 3985 your patch includes sufficient directory information for the 3986 affected files). 3987 3988 We prefer patches as plain text. MIME attachments are discouraged, 3989 and compressed attachments must not be used. 3990 3991* If one logical set of modifications affects or creates several 3992 files, all these changes shall be submitted in a SINGLE patch file. 3993 3994* Changesets that contain different, unrelated modifications shall be 3995 submitted as SEPARATE patches, one patch per changeset. 3996 3997 3998Notes: 3999 4000* Before sending the patch, run the MAKEALL script on your patched 4001 source tree and make sure that no errors or warnings are reported 4002 for any of the boards. 4003 4004* Keep your modifications to the necessary minimum: A patch 4005 containing several unrelated changes or arbitrary reformats will be 4006 returned with a request to re-formatting / split it. 4007 4008* If you modify existing code, make sure that your new code does not 4009 add to the memory footprint of the code ;-) Small is beautiful! 4010 When adding new features, these should compile conditionally only 4011 (using #ifdef), and the resulting code with the new feature 4012 disabled must not need more memory than the old code without your 4013 modification. 4014 4015* Remember that there is a size limit of 40 kB per message on the 4016 u-boot-users mailing list. Bigger patches will be moderated. If 4017 they are reasonable and not bigger than 100 kB, they will be 4018 acknowledged. Even bigger patches should be avoided. 4019