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_ETH2ADDR 1099 CONFIG_ETH3ADDR 1100 1101 Define a default value for Ethernet address to use 1102 for the respective Ethernet interface, in case this 1103 is not determined automatically. 1104 1105- IP address: 1106 CONFIG_IPADDR 1107 1108 Define a default value for the IP address to use for 1109 the default Ethernet interface, in case this is not 1110 determined through e.g. bootp. 1111 1112- Server IP address: 1113 CONFIG_SERVERIP 1114 1115 Defines a default value for the IP address of a TFTP 1116 server to contact when using the "tftboot" command. 1117 1118- Multicast TFTP Mode: 1119 CONFIG_MCAST_TFTP 1120 1121 Defines whether you want to support multicast TFTP as per 1122 rfc-2090; for example to work with atftp. Lets lots of targets 1123 tftp down the same boot image concurrently. Note: the Ethernet 1124 driver in use must provide a function: mcast() to join/leave a 1125 multicast group. 1126 1127 CONFIG_BOOTP_RANDOM_DELAY 1128- BOOTP Recovery Mode: 1129 CONFIG_BOOTP_RANDOM_DELAY 1130 1131 If you have many targets in a network that try to 1132 boot using BOOTP, you may want to avoid that all 1133 systems send out BOOTP requests at precisely the same 1134 moment (which would happen for instance at recovery 1135 from a power failure, when all systems will try to 1136 boot, thus flooding the BOOTP server. Defining 1137 CONFIG_BOOTP_RANDOM_DELAY causes a random delay to be 1138 inserted before sending out BOOTP requests. The 1139 following delays are inserted then: 1140 1141 1st BOOTP request: delay 0 ... 1 sec 1142 2nd BOOTP request: delay 0 ... 2 sec 1143 3rd BOOTP request: delay 0 ... 4 sec 1144 4th and following 1145 BOOTP requests: delay 0 ... 8 sec 1146 1147- DHCP Advanced Options: 1148 You can fine tune the DHCP functionality by defining 1149 CONFIG_BOOTP_* symbols: 1150 1151 CONFIG_BOOTP_SUBNETMASK 1152 CONFIG_BOOTP_GATEWAY 1153 CONFIG_BOOTP_HOSTNAME 1154 CONFIG_BOOTP_NISDOMAIN 1155 CONFIG_BOOTP_BOOTPATH 1156 CONFIG_BOOTP_BOOTFILESIZE 1157 CONFIG_BOOTP_DNS 1158 CONFIG_BOOTP_DNS2 1159 CONFIG_BOOTP_SEND_HOSTNAME 1160 CONFIG_BOOTP_NTPSERVER 1161 CONFIG_BOOTP_TIMEOFFSET 1162 CONFIG_BOOTP_VENDOREX 1163 1164 CONFIG_BOOTP_SERVERIP - TFTP server will be the serverip 1165 environment variable, not the BOOTP server. 1166 1167 CONFIG_BOOTP_DNS2 - If a DHCP client requests the DNS 1168 serverip from a DHCP server, it is possible that more 1169 than one DNS serverip is offered to the client. 1170 If CONFIG_BOOTP_DNS2 is enabled, the secondary DNS 1171 serverip will be stored in the additional environment 1172 variable "dnsip2". The first DNS serverip is always 1173 stored in the variable "dnsip", when CONFIG_BOOTP_DNS 1174 is defined. 1175 1176 CONFIG_BOOTP_SEND_HOSTNAME - Some DHCP servers are capable 1177 to do a dynamic update of a DNS server. To do this, they 1178 need the hostname of the DHCP requester. 1179 If CONFIG_BOOTP_SEND_HOSTNAME is defined, the content 1180 of the "hostname" environment variable is passed as 1181 option 12 to the DHCP server. 1182 1183 CONFIG_BOOTP_DHCP_REQUEST_DELAY 1184 1185 A 32bit value in microseconds for a delay between 1186 receiving a "DHCP Offer" and sending the "DHCP Request". 1187 This fixes a problem with certain DHCP servers that don't 1188 respond 100% of the time to a "DHCP request". E.g. On an 1189 AT91RM9200 processor running at 180MHz, this delay needed 1190 to be *at least* 15,000 usec before a Windows Server 2003 1191 DHCP server would reply 100% of the time. I recommend at 1192 least 50,000 usec to be safe. The alternative is to hope 1193 that one of the retries will be successful but note that 1194 the DHCP timeout and retry process takes a longer than 1195 this delay. 1196 1197 - CDP Options: 1198 CONFIG_CDP_DEVICE_ID 1199 1200 The device id used in CDP trigger frames. 1201 1202 CONFIG_CDP_DEVICE_ID_PREFIX 1203 1204 A two character string which is prefixed to the MAC address 1205 of the device. 1206 1207 CONFIG_CDP_PORT_ID 1208 1209 A printf format string which contains the ascii name of 1210 the port. Normally is set to "eth%d" which sets 1211 eth0 for the first Ethernet, eth1 for the second etc. 1212 1213 CONFIG_CDP_CAPABILITIES 1214 1215 A 32bit integer which indicates the device capabilities; 1216 0x00000010 for a normal host which does not forwards. 1217 1218 CONFIG_CDP_VERSION 1219 1220 An ascii string containing the version of the software. 1221 1222 CONFIG_CDP_PLATFORM 1223 1224 An ascii string containing the name of the platform. 1225 1226 CONFIG_CDP_TRIGGER 1227 1228 A 32bit integer sent on the trigger. 1229 1230 CONFIG_CDP_POWER_CONSUMPTION 1231 1232 A 16bit integer containing the power consumption of the 1233 device in .1 of milliwatts. 1234 1235 CONFIG_CDP_APPLIANCE_VLAN_TYPE 1236 1237 A byte containing the id of the VLAN. 1238 1239- Status LED: CONFIG_STATUS_LED 1240 1241 Several configurations allow to display the current 1242 status using a LED. For instance, the LED will blink 1243 fast while running U-Boot code, stop blinking as 1244 soon as a reply to a BOOTP request was received, and 1245 start blinking slow once the Linux kernel is running 1246 (supported by a status LED driver in the Linux 1247 kernel). Defining CONFIG_STATUS_LED enables this 1248 feature in U-Boot. 1249 1250- CAN Support: CONFIG_CAN_DRIVER 1251 1252 Defining CONFIG_CAN_DRIVER enables CAN driver support 1253 on those systems that support this (optional) 1254 feature, like the TQM8xxL modules. 1255 1256- I2C Support: CONFIG_HARD_I2C | CONFIG_SOFT_I2C 1257 1258 These enable I2C serial bus commands. Defining either of 1259 (but not both of) CONFIG_HARD_I2C or CONFIG_SOFT_I2C will 1260 include the appropriate I2C driver for the selected CPU. 1261 1262 This will allow you to use i2c commands at the u-boot 1263 command line (as long as you set CONFIG_CMD_I2C in 1264 CONFIG_COMMANDS) and communicate with i2c based realtime 1265 clock chips. See common/cmd_i2c.c for a description of the 1266 command line interface. 1267 1268 CONFIG_I2C_CMD_TREE is a recommended option that places 1269 all I2C commands under a single 'i2c' root command. The 1270 older 'imm', 'imd', 'iprobe' etc. commands are considered 1271 deprecated and may disappear in the future. 1272 1273 CONFIG_HARD_I2C selects a hardware I2C controller. 1274 1275 CONFIG_SOFT_I2C configures u-boot to use a software (aka 1276 bit-banging) driver instead of CPM or similar hardware 1277 support for I2C. 1278 1279 There are several other quantities that must also be 1280 defined when you define CONFIG_HARD_I2C or CONFIG_SOFT_I2C. 1281 1282 In both cases you will need to define CFG_I2C_SPEED 1283 to be the frequency (in Hz) at which you wish your i2c bus 1284 to run and CFG_I2C_SLAVE to be the address of this node (ie 1285 the CPU's i2c node address). 1286 1287 Now, the u-boot i2c code for the mpc8xx (cpu/mpc8xx/i2c.c) 1288 sets the CPU up as a master node and so its address should 1289 therefore be cleared to 0 (See, eg, MPC823e User's Manual 1290 p.16-473). So, set CFG_I2C_SLAVE to 0. 1291 1292 That's all that's required for CONFIG_HARD_I2C. 1293 1294 If you use the software i2c interface (CONFIG_SOFT_I2C) 1295 then the following macros need to be defined (examples are 1296 from include/configs/lwmon.h): 1297 1298 I2C_INIT 1299 1300 (Optional). Any commands necessary to enable the I2C 1301 controller or configure ports. 1302 1303 eg: #define I2C_INIT (immr->im_cpm.cp_pbdir |= PB_SCL) 1304 1305 I2C_PORT 1306 1307 (Only for MPC8260 CPU). The I/O port to use (the code 1308 assumes both bits are on the same port). Valid values 1309 are 0..3 for ports A..D. 1310 1311 I2C_ACTIVE 1312 1313 The code necessary to make the I2C data line active 1314 (driven). If the data line is open collector, this 1315 define can be null. 1316 1317 eg: #define I2C_ACTIVE (immr->im_cpm.cp_pbdir |= PB_SDA) 1318 1319 I2C_TRISTATE 1320 1321 The code necessary to make the I2C data line tri-stated 1322 (inactive). If the data line is open collector, this 1323 define can be null. 1324 1325 eg: #define I2C_TRISTATE (immr->im_cpm.cp_pbdir &= ~PB_SDA) 1326 1327 I2C_READ 1328 1329 Code that returns TRUE if the I2C data line is high, 1330 FALSE if it is low. 1331 1332 eg: #define I2C_READ ((immr->im_cpm.cp_pbdat & PB_SDA) != 0) 1333 1334 I2C_SDA(bit) 1335 1336 If <bit> is TRUE, sets the I2C data line high. If it 1337 is FALSE, it clears it (low). 1338 1339 eg: #define I2C_SDA(bit) \ 1340 if(bit) immr->im_cpm.cp_pbdat |= PB_SDA; \ 1341 else immr->im_cpm.cp_pbdat &= ~PB_SDA 1342 1343 I2C_SCL(bit) 1344 1345 If <bit> is TRUE, sets the I2C clock line high. If it 1346 is FALSE, it clears it (low). 1347 1348 eg: #define I2C_SCL(bit) \ 1349 if(bit) immr->im_cpm.cp_pbdat |= PB_SCL; \ 1350 else immr->im_cpm.cp_pbdat &= ~PB_SCL 1351 1352 I2C_DELAY 1353 1354 This delay is invoked four times per clock cycle so this 1355 controls the rate of data transfer. The data rate thus 1356 is 1 / (I2C_DELAY * 4). Often defined to be something 1357 like: 1358 1359 #define I2C_DELAY udelay(2) 1360 1361 CFG_I2C_INIT_BOARD 1362 1363 When a board is reset during an i2c bus transfer 1364 chips might think that the current transfer is still 1365 in progress. On some boards it is possible to access 1366 the i2c SCLK line directly, either by using the 1367 processor pin as a GPIO or by having a second pin 1368 connected to the bus. If this option is defined a 1369 custom i2c_init_board() routine in boards/xxx/board.c 1370 is run early in the boot sequence. 1371 1372 CONFIG_I2CFAST (PPC405GP|PPC405EP only) 1373 1374 This option enables configuration of bi_iic_fast[] flags 1375 in u-boot bd_info structure based on u-boot environment 1376 variable "i2cfast". (see also i2cfast) 1377 1378 CONFIG_I2C_MULTI_BUS 1379 1380 This option allows the use of multiple I2C buses, each of which 1381 must have a controller. At any point in time, only one bus is 1382 active. To switch to a different bus, use the 'i2c dev' command. 1383 Note that bus numbering is zero-based. 1384 1385 CFG_I2C_NOPROBES 1386 1387 This option specifies a list of I2C devices that will be skipped 1388 when the 'i2c probe' command is issued (or 'iprobe' using the legacy 1389 command). If CONFIG_I2C_MULTI_BUS is set, specify a list of bus-device 1390 pairs. Otherwise, specify a 1D array of device addresses 1391 1392 e.g. 1393 #undef CONFIG_I2C_MULTI_BUS 1394 #define CFG_I2C_NOPROBES {0x50,0x68} 1395 1396 will skip addresses 0x50 and 0x68 on a board with one I2C bus 1397 1398 #define CONFIG_I2C_MULTI_BUS 1399 #define CFG_I2C_MULTI_NOPROBES {{0,0x50},{0,0x68},{1,0x54}} 1400 1401 will skip addresses 0x50 and 0x68 on bus 0 and address 0x54 on bus 1 1402 1403 CFG_SPD_BUS_NUM 1404 1405 If defined, then this indicates the I2C bus number for DDR SPD. 1406 If not defined, then U-Boot assumes that SPD is on I2C bus 0. 1407 1408 CFG_RTC_BUS_NUM 1409 1410 If defined, then this indicates the I2C bus number for the RTC. 1411 If not defined, then U-Boot assumes that RTC is on I2C bus 0. 1412 1413 CFG_DTT_BUS_NUM 1414 1415 If defined, then this indicates the I2C bus number for the DTT. 1416 If not defined, then U-Boot assumes that DTT is on I2C bus 0. 1417 1418 CFG_I2C_DTT_ADDR: 1419 1420 If defined, specifies the I2C address of the DTT device. 1421 If not defined, then U-Boot uses predefined value for 1422 specified DTT device. 1423 1424 CONFIG_FSL_I2C 1425 1426 Define this option if you want to use Freescale's I2C driver in 1427 drivers/i2c/fsl_i2c.c. 1428 1429 1430- SPI Support: CONFIG_SPI 1431 1432 Enables SPI driver (so far only tested with 1433 SPI EEPROM, also an instance works with Crystal A/D and 1434 D/As on the SACSng board) 1435 1436 CONFIG_SPI_X 1437 1438 Enables extended (16-bit) SPI EEPROM addressing. 1439 (symmetrical to CONFIG_I2C_X) 1440 1441 CONFIG_SOFT_SPI 1442 1443 Enables a software (bit-bang) SPI driver rather than 1444 using hardware support. This is a general purpose 1445 driver that only requires three general I/O port pins 1446 (two outputs, one input) to function. If this is 1447 defined, the board configuration must define several 1448 SPI configuration items (port pins to use, etc). For 1449 an example, see include/configs/sacsng.h. 1450 1451 CONFIG_HARD_SPI 1452 1453 Enables a hardware SPI driver for general-purpose reads 1454 and writes. As with CONFIG_SOFT_SPI, the board configuration 1455 must define a list of chip-select function pointers. 1456 Currently supported on some MPC8xxx processors. For an 1457 example, see include/configs/mpc8349emds.h. 1458 1459 CONFIG_MXC_SPI 1460 1461 Enables the driver for the SPI controllers on i.MX and MXC 1462 SoCs. Currently only i.MX31 is supported. 1463 1464- FPGA Support: CONFIG_FPGA 1465 1466 Enables FPGA subsystem. 1467 1468 CONFIG_FPGA_<vendor> 1469 1470 Enables support for specific chip vendors. 1471 (ALTERA, XILINX) 1472 1473 CONFIG_FPGA_<family> 1474 1475 Enables support for FPGA family. 1476 (SPARTAN2, SPARTAN3, VIRTEX2, CYCLONE2, ACEX1K, ACEX) 1477 1478 CONFIG_FPGA_COUNT 1479 1480 Specify the number of FPGA devices to support. 1481 1482 CFG_FPGA_PROG_FEEDBACK 1483 1484 Enable printing of hash marks during FPGA configuration. 1485 1486 CFG_FPGA_CHECK_BUSY 1487 1488 Enable checks on FPGA configuration interface busy 1489 status by the configuration function. This option 1490 will require a board or device specific function to 1491 be written. 1492 1493 CONFIG_FPGA_DELAY 1494 1495 If defined, a function that provides delays in the FPGA 1496 configuration driver. 1497 1498 CFG_FPGA_CHECK_CTRLC 1499 Allow Control-C to interrupt FPGA configuration 1500 1501 CFG_FPGA_CHECK_ERROR 1502 1503 Check for configuration errors during FPGA bitfile 1504 loading. For example, abort during Virtex II 1505 configuration if the INIT_B line goes low (which 1506 indicated a CRC error). 1507 1508 CFG_FPGA_WAIT_INIT 1509 1510 Maximum time to wait for the INIT_B line to deassert 1511 after PROB_B has been deasserted during a Virtex II 1512 FPGA configuration sequence. The default time is 500 1513 ms. 1514 1515 CFG_FPGA_WAIT_BUSY 1516 1517 Maximum time to wait for BUSY to deassert during 1518 Virtex II FPGA configuration. The default is 5 ms. 1519 1520 CFG_FPGA_WAIT_CONFIG 1521 1522 Time to wait after FPGA configuration. The default is 1523 200 ms. 1524 1525- Configuration Management: 1526 CONFIG_IDENT_STRING 1527 1528 If defined, this string will be added to the U-Boot 1529 version information (U_BOOT_VERSION) 1530 1531- Vendor Parameter Protection: 1532 1533 U-Boot considers the values of the environment 1534 variables "serial#" (Board Serial Number) and 1535 "ethaddr" (Ethernet Address) to be parameters that 1536 are set once by the board vendor / manufacturer, and 1537 protects these variables from casual modification by 1538 the user. Once set, these variables are read-only, 1539 and write or delete attempts are rejected. You can 1540 change this behaviour: 1541 1542 If CONFIG_ENV_OVERWRITE is #defined in your config 1543 file, the write protection for vendor parameters is 1544 completely disabled. Anybody can change or delete 1545 these parameters. 1546 1547 Alternatively, if you #define _both_ CONFIG_ETHADDR 1548 _and_ CONFIG_OVERWRITE_ETHADDR_ONCE, a default 1549 Ethernet address is installed in the environment, 1550 which can be changed exactly ONCE by the user. [The 1551 serial# is unaffected by this, i. e. it remains 1552 read-only.] 1553 1554- Protected RAM: 1555 CONFIG_PRAM 1556 1557 Define this variable to enable the reservation of 1558 "protected RAM", i. e. RAM which is not overwritten 1559 by U-Boot. Define CONFIG_PRAM to hold the number of 1560 kB you want to reserve for pRAM. You can overwrite 1561 this default value by defining an environment 1562 variable "pram" to the number of kB you want to 1563 reserve. Note that the board info structure will 1564 still show the full amount of RAM. If pRAM is 1565 reserved, a new environment variable "mem" will 1566 automatically be defined to hold the amount of 1567 remaining RAM in a form that can be passed as boot 1568 argument to Linux, for instance like that: 1569 1570 setenv bootargs ... mem=\${mem} 1571 saveenv 1572 1573 This way you can tell Linux not to use this memory, 1574 either, which results in a memory region that will 1575 not be affected by reboots. 1576 1577 *WARNING* If your board configuration uses automatic 1578 detection of the RAM size, you must make sure that 1579 this memory test is non-destructive. So far, the 1580 following board configurations are known to be 1581 "pRAM-clean": 1582 1583 ETX094, IVMS8, IVML24, SPD8xx, TQM8xxL, 1584 HERMES, IP860, RPXlite, LWMON, LANTEC, 1585 PCU_E, FLAGADM, TQM8260 1586 1587- Error Recovery: 1588 CONFIG_PANIC_HANG 1589 1590 Define this variable to stop the system in case of a 1591 fatal error, so that you have to reset it manually. 1592 This is probably NOT a good idea for an embedded 1593 system where you want the system to reboot 1594 automatically as fast as possible, but it may be 1595 useful during development since you can try to debug 1596 the conditions that lead to the situation. 1597 1598 CONFIG_NET_RETRY_COUNT 1599 1600 This variable defines the number of retries for 1601 network operations like ARP, RARP, TFTP, or BOOTP 1602 before giving up the operation. If not defined, a 1603 default value of 5 is used. 1604 1605 CONFIG_ARP_TIMEOUT 1606 1607 Timeout waiting for an ARP reply in milliseconds. 1608 1609- Command Interpreter: 1610 CONFIG_AUTO_COMPLETE 1611 1612 Enable auto completion of commands using TAB. 1613 1614 Note that this feature has NOT been implemented yet 1615 for the "hush" shell. 1616 1617 1618 CFG_HUSH_PARSER 1619 1620 Define this variable to enable the "hush" shell (from 1621 Busybox) as command line interpreter, thus enabling 1622 powerful command line syntax like 1623 if...then...else...fi conditionals or `&&' and '||' 1624 constructs ("shell scripts"). 1625 1626 If undefined, you get the old, much simpler behaviour 1627 with a somewhat smaller memory footprint. 1628 1629 1630 CFG_PROMPT_HUSH_PS2 1631 1632 This defines the secondary prompt string, which is 1633 printed when the command interpreter needs more input 1634 to complete a command. Usually "> ". 1635 1636 Note: 1637 1638 In the current implementation, the local variables 1639 space and global environment variables space are 1640 separated. Local variables are those you define by 1641 simply typing `name=value'. To access a local 1642 variable later on, you have write `$name' or 1643 `${name}'; to execute the contents of a variable 1644 directly type `$name' at the command prompt. 1645 1646 Global environment variables are those you use 1647 setenv/printenv to work with. To run a command stored 1648 in such a variable, you need to use the run command, 1649 and you must not use the '$' sign to access them. 1650 1651 To store commands and special characters in a 1652 variable, please use double quotation marks 1653 surrounding the whole text of the variable, instead 1654 of the backslashes before semicolons and special 1655 symbols. 1656 1657- Commandline Editing and History: 1658 CONFIG_CMDLINE_EDITING 1659 1660 Enable editing and History functions for interactive 1661 commandline input operations 1662 1663- Default Environment: 1664 CONFIG_EXTRA_ENV_SETTINGS 1665 1666 Define this to contain any number of null terminated 1667 strings (variable = value pairs) that will be part of 1668 the default environment compiled into the boot image. 1669 1670 For example, place something like this in your 1671 board's config file: 1672 1673 #define CONFIG_EXTRA_ENV_SETTINGS \ 1674 "myvar1=value1\0" \ 1675 "myvar2=value2\0" 1676 1677 Warning: This method is based on knowledge about the 1678 internal format how the environment is stored by the 1679 U-Boot code. This is NOT an official, exported 1680 interface! Although it is unlikely that this format 1681 will change soon, there is no guarantee either. 1682 You better know what you are doing here. 1683 1684 Note: overly (ab)use of the default environment is 1685 discouraged. Make sure to check other ways to preset 1686 the environment like the autoscript function or the 1687 boot command first. 1688 1689- DataFlash Support: 1690 CONFIG_HAS_DATAFLASH 1691 1692 Defining this option enables DataFlash features and 1693 allows to read/write in Dataflash via the standard 1694 commands cp, md... 1695 1696- SystemACE Support: 1697 CONFIG_SYSTEMACE 1698 1699 Adding this option adds support for Xilinx SystemACE 1700 chips attached via some sort of local bus. The address 1701 of the chip must also be defined in the 1702 CFG_SYSTEMACE_BASE macro. For example: 1703 1704 #define CONFIG_SYSTEMACE 1705 #define CFG_SYSTEMACE_BASE 0xf0000000 1706 1707 When SystemACE support is added, the "ace" device type 1708 becomes available to the fat commands, i.e. fatls. 1709 1710- TFTP Fixed UDP Port: 1711 CONFIG_TFTP_PORT 1712 1713 If this is defined, the environment variable tftpsrcp 1714 is used to supply the TFTP UDP source port value. 1715 If tftpsrcp isn't defined, the normal pseudo-random port 1716 number generator is used. 1717 1718 Also, the environment variable tftpdstp is used to supply 1719 the TFTP UDP destination port value. If tftpdstp isn't 1720 defined, the normal port 69 is used. 1721 1722 The purpose for tftpsrcp is to allow a TFTP server to 1723 blindly start the TFTP transfer using the pre-configured 1724 target IP address and UDP port. This has the effect of 1725 "punching through" the (Windows XP) firewall, allowing 1726 the remainder of the TFTP transfer to proceed normally. 1727 A better solution is to properly configure the firewall, 1728 but sometimes that is not allowed. 1729 1730- Show boot progress: 1731 CONFIG_SHOW_BOOT_PROGRESS 1732 1733 Defining this option allows to add some board- 1734 specific code (calling a user-provided function 1735 "show_boot_progress(int)") that enables you to show 1736 the system's boot progress on some display (for 1737 example, some LED's) on your board. At the moment, 1738 the following checkpoints are implemented: 1739 1740Legacy uImage format: 1741 1742 Arg Where When 1743 1 common/cmd_bootm.c before attempting to boot an image 1744 -1 common/cmd_bootm.c Image header has bad magic number 1745 2 common/cmd_bootm.c Image header has correct magic number 1746 -2 common/cmd_bootm.c Image header has bad checksum 1747 3 common/cmd_bootm.c Image header has correct checksum 1748 -3 common/cmd_bootm.c Image data has bad checksum 1749 4 common/cmd_bootm.c Image data has correct checksum 1750 -4 common/cmd_bootm.c Image is for unsupported architecture 1751 5 common/cmd_bootm.c Architecture check OK 1752 -5 common/cmd_bootm.c Wrong Image Type (not kernel, multi) 1753 6 common/cmd_bootm.c Image Type check OK 1754 -6 common/cmd_bootm.c gunzip uncompression error 1755 -7 common/cmd_bootm.c Unimplemented compression type 1756 7 common/cmd_bootm.c Uncompression OK 1757 8 common/cmd_bootm.c No uncompress/copy overwrite error 1758 -9 common/cmd_bootm.c Unsupported OS (not Linux, BSD, VxWorks, QNX) 1759 1760 9 common/image.c Start initial ramdisk verification 1761 -10 common/image.c Ramdisk header has bad magic number 1762 -11 common/image.c Ramdisk header has bad checksum 1763 10 common/image.c Ramdisk header is OK 1764 -12 common/image.c Ramdisk data has bad checksum 1765 11 common/image.c Ramdisk data has correct checksum 1766 12 common/image.c Ramdisk verification complete, start loading 1767 -13 common/image.c Wrong Image Type (not PPC Linux ramdisk) 1768 13 common/image.c Start multifile image verification 1769 14 common/image.c No initial ramdisk, no multifile, continue. 1770 1771 15 lib_<arch>/bootm.c All preparation done, transferring control to OS 1772 1773 -30 lib_ppc/board.c Fatal error, hang the system 1774 -31 post/post.c POST test failed, detected by post_output_backlog() 1775 -32 post/post.c POST test failed, detected by post_run_single() 1776 1777 34 common/cmd_doc.c before loading a Image from a DOC device 1778 -35 common/cmd_doc.c Bad usage of "doc" command 1779 35 common/cmd_doc.c correct usage of "doc" command 1780 -36 common/cmd_doc.c No boot device 1781 36 common/cmd_doc.c correct boot device 1782 -37 common/cmd_doc.c Unknown Chip ID on boot device 1783 37 common/cmd_doc.c correct chip ID found, device available 1784 -38 common/cmd_doc.c Read Error on boot device 1785 38 common/cmd_doc.c reading Image header from DOC device OK 1786 -39 common/cmd_doc.c Image header has bad magic number 1787 39 common/cmd_doc.c Image header has correct magic number 1788 -40 common/cmd_doc.c Error reading Image from DOC device 1789 40 common/cmd_doc.c Image header has correct magic number 1790 41 common/cmd_ide.c before loading a Image from a IDE device 1791 -42 common/cmd_ide.c Bad usage of "ide" command 1792 42 common/cmd_ide.c correct usage of "ide" command 1793 -43 common/cmd_ide.c No boot device 1794 43 common/cmd_ide.c boot device found 1795 -44 common/cmd_ide.c Device not available 1796 44 common/cmd_ide.c Device available 1797 -45 common/cmd_ide.c wrong partition selected 1798 45 common/cmd_ide.c partition selected 1799 -46 common/cmd_ide.c Unknown partition table 1800 46 common/cmd_ide.c valid partition table found 1801 -47 common/cmd_ide.c Invalid partition type 1802 47 common/cmd_ide.c correct partition type 1803 -48 common/cmd_ide.c Error reading Image Header on boot device 1804 48 common/cmd_ide.c reading Image Header from IDE device OK 1805 -49 common/cmd_ide.c Image header has bad magic number 1806 49 common/cmd_ide.c Image header has correct magic number 1807 -50 common/cmd_ide.c Image header has bad checksum 1808 50 common/cmd_ide.c Image header has correct checksum 1809 -51 common/cmd_ide.c Error reading Image from IDE device 1810 51 common/cmd_ide.c reading Image from IDE device OK 1811 52 common/cmd_nand.c before loading a Image from a NAND device 1812 -53 common/cmd_nand.c Bad usage of "nand" command 1813 53 common/cmd_nand.c correct usage of "nand" command 1814 -54 common/cmd_nand.c No boot device 1815 54 common/cmd_nand.c boot device found 1816 -55 common/cmd_nand.c Unknown Chip ID on boot device 1817 55 common/cmd_nand.c correct chip ID found, device available 1818 -56 common/cmd_nand.c Error reading Image Header on boot device 1819 56 common/cmd_nand.c reading Image Header from NAND device OK 1820 -57 common/cmd_nand.c Image header has bad magic number 1821 57 common/cmd_nand.c Image header has correct magic number 1822 -58 common/cmd_nand.c Error reading Image from NAND device 1823 58 common/cmd_nand.c reading Image from NAND device OK 1824 1825 -60 common/env_common.c Environment has a bad CRC, using default 1826 1827 64 net/eth.c starting with Ethernet configuration. 1828 -64 net/eth.c no Ethernet found. 1829 65 net/eth.c Ethernet found. 1830 1831 -80 common/cmd_net.c usage wrong 1832 80 common/cmd_net.c before calling NetLoop() 1833 -81 common/cmd_net.c some error in NetLoop() occurred 1834 81 common/cmd_net.c NetLoop() back without error 1835 -82 common/cmd_net.c size == 0 (File with size 0 loaded) 1836 82 common/cmd_net.c trying automatic boot 1837 83 common/cmd_net.c running autoscript 1838 -83 common/cmd_net.c some error in automatic boot or autoscript 1839 84 common/cmd_net.c end without errors 1840 1841FIT uImage format: 1842 1843 Arg Where When 1844 100 common/cmd_bootm.c Kernel FIT Image has correct format 1845 -100 common/cmd_bootm.c Kernel FIT Image has incorrect format 1846 101 common/cmd_bootm.c No Kernel subimage unit name, using configuration 1847 -101 common/cmd_bootm.c Can't get configuration for kernel subimage 1848 102 common/cmd_bootm.c Kernel unit name specified 1849 -103 common/cmd_bootm.c Can't get kernel subimage node offset 1850 103 common/cmd_bootm.c Found configuration node 1851 104 common/cmd_bootm.c Got kernel subimage node offset 1852 -104 common/cmd_bootm.c Kernel subimage hash verification failed 1853 105 common/cmd_bootm.c Kernel subimage hash verification OK 1854 -105 common/cmd_bootm.c Kernel subimage is for unsupported architecture 1855 106 common/cmd_bootm.c Architecture check OK 1856 -106 common/cmd_bootm.c Kernel subimage has wrong type 1857 107 common/cmd_bootm.c Kernel subimage type OK 1858 -107 common/cmd_bootm.c Can't get kernel subimage data/size 1859 108 common/cmd_bootm.c Got kernel subimage data/size 1860 -108 common/cmd_bootm.c Wrong image type (not legacy, FIT) 1861 -109 common/cmd_bootm.c Can't get kernel subimage type 1862 -110 common/cmd_bootm.c Can't get kernel subimage comp 1863 -111 common/cmd_bootm.c Can't get kernel subimage os 1864 -112 common/cmd_bootm.c Can't get kernel subimage load address 1865 -113 common/cmd_bootm.c Image uncompress/copy overwrite error 1866 1867 120 common/image.c Start initial ramdisk verification 1868 -120 common/image.c Ramdisk FIT image has incorrect format 1869 121 common/image.c Ramdisk FIT image has correct format 1870 122 common/image.c No ramdisk subimage unit name, using configuration 1871 -122 common/image.c Can't get configuration for ramdisk subimage 1872 123 common/image.c Ramdisk unit name specified 1873 -124 common/image.c Can't get ramdisk subimage node offset 1874 125 common/image.c Got ramdisk subimage node offset 1875 -125 common/image.c Ramdisk subimage hash verification failed 1876 126 common/image.c Ramdisk subimage hash verification OK 1877 -126 common/image.c Ramdisk subimage for unsupported architecture 1878 127 common/image.c Architecture check OK 1879 -127 common/image.c Can't get ramdisk subimage data/size 1880 128 common/image.c Got ramdisk subimage data/size 1881 129 common/image.c Can't get ramdisk load address 1882 -129 common/image.c Got ramdisk load address 1883 1884 -130 common/cmd_doc.c Incorrect FIT image format 1885 131 common/cmd_doc.c FIT image format OK 1886 1887 -140 common/cmd_ide.c Incorrect FIT image format 1888 141 common/cmd_ide.c FIT image format OK 1889 1890 -150 common/cmd_nand.c Incorrect FIT image format 1891 151 common/cmd_nand.c FIT image format OK 1892 1893 1894Modem Support: 1895-------------- 1896 1897[so far only for SMDK2400 and TRAB boards] 1898 1899- Modem support enable: 1900 CONFIG_MODEM_SUPPORT 1901 1902- RTS/CTS Flow control enable: 1903 CONFIG_HWFLOW 1904 1905- Modem debug support: 1906 CONFIG_MODEM_SUPPORT_DEBUG 1907 1908 Enables debugging stuff (char screen[1024], dbg()) 1909 for modem support. Useful only with BDI2000. 1910 1911- Interrupt support (PPC): 1912 1913 There are common interrupt_init() and timer_interrupt() 1914 for all PPC archs. interrupt_init() calls interrupt_init_cpu() 1915 for CPU specific initialization. interrupt_init_cpu() 1916 should set decrementer_count to appropriate value. If 1917 CPU resets decrementer automatically after interrupt 1918 (ppc4xx) it should set decrementer_count to zero. 1919 timer_interrupt() calls timer_interrupt_cpu() for CPU 1920 specific handling. If board has watchdog / status_led 1921 / other_activity_monitor it works automatically from 1922 general timer_interrupt(). 1923 1924- General: 1925 1926 In the target system modem support is enabled when a 1927 specific key (key combination) is pressed during 1928 power-on. Otherwise U-Boot will boot normally 1929 (autoboot). The key_pressed() function is called from 1930 board_init(). Currently key_pressed() is a dummy 1931 function, returning 1 and thus enabling modem 1932 initialization. 1933 1934 If there are no modem init strings in the 1935 environment, U-Boot proceed to autoboot; the 1936 previous output (banner, info printfs) will be 1937 suppressed, though. 1938 1939 See also: doc/README.Modem 1940 1941 1942Configuration Settings: 1943----------------------- 1944 1945- CFG_LONGHELP: Defined when you want long help messages included; 1946 undefine this when you're short of memory. 1947 1948- CFG_PROMPT: This is what U-Boot prints on the console to 1949 prompt for user input. 1950 1951- CFG_CBSIZE: Buffer size for input from the Console 1952 1953- CFG_PBSIZE: Buffer size for Console output 1954 1955- CFG_MAXARGS: max. Number of arguments accepted for monitor commands 1956 1957- CFG_BARGSIZE: Buffer size for Boot Arguments which are passed to 1958 the application (usually a Linux kernel) when it is 1959 booted 1960 1961- CFG_BAUDRATE_TABLE: 1962 List of legal baudrate settings for this board. 1963 1964- CFG_CONSOLE_INFO_QUIET 1965 Suppress display of console information at boot. 1966 1967- CFG_CONSOLE_IS_IN_ENV 1968 If the board specific function 1969 extern int overwrite_console (void); 1970 returns 1, the stdin, stderr and stdout are switched to the 1971 serial port, else the settings in the environment are used. 1972 1973- CFG_CONSOLE_OVERWRITE_ROUTINE 1974 Enable the call to overwrite_console(). 1975 1976- CFG_CONSOLE_ENV_OVERWRITE 1977 Enable overwrite of previous console environment settings. 1978 1979- CFG_MEMTEST_START, CFG_MEMTEST_END: 1980 Begin and End addresses of the area used by the 1981 simple memory test. 1982 1983- CFG_ALT_MEMTEST: 1984 Enable an alternate, more extensive memory test. 1985 1986- CFG_MEMTEST_SCRATCH: 1987 Scratch address used by the alternate memory test 1988 You only need to set this if address zero isn't writeable 1989 1990- CFG_MEM_TOP_HIDE (PPC only): 1991 If CFG_MEM_TOP_HIDE is defined in the board config header, 1992 this specified memory area will get subtracted from the top 1993 (end) of RAM and won't get "touched" at all by U-Boot. By 1994 fixing up gd->ram_size the Linux kernel should gets passed 1995 the now "corrected" memory size and won't touch it either. 1996 This should work for arch/ppc and arch/powerpc. Only Linux 1997 board ports in arch/powerpc with bootwrapper support that 1998 recalculate the memory size from the SDRAM controller setup 1999 will have to get fixed in Linux additionally. 2000 2001 This option can be used as a workaround for the 440EPx/GRx 2002 CHIP 11 errata where the last 256 bytes in SDRAM shouldn't 2003 be touched. 2004 2005 WARNING: Please make sure that this value is a multiple of 2006 the Linux page size (normally 4k). If this is not the case, 2007 then the end address of the Linux memory will be located at a 2008 non page size aligned address and this could cause major 2009 problems. 2010 2011- CFG_TFTP_LOADADDR: 2012 Default load address for network file downloads 2013 2014- CFG_LOADS_BAUD_CHANGE: 2015 Enable temporary baudrate change while serial download 2016 2017- CFG_SDRAM_BASE: 2018 Physical start address of SDRAM. _Must_ be 0 here. 2019 2020- CFG_MBIO_BASE: 2021 Physical start address of Motherboard I/O (if using a 2022 Cogent motherboard) 2023 2024- CFG_FLASH_BASE: 2025 Physical start address of Flash memory. 2026 2027- CFG_MONITOR_BASE: 2028 Physical start address of boot monitor code (set by 2029 make config files to be same as the text base address 2030 (TEXT_BASE) used when linking) - same as 2031 CFG_FLASH_BASE when booting from flash. 2032 2033- CFG_MONITOR_LEN: 2034 Size of memory reserved for monitor code, used to 2035 determine _at_compile_time_ (!) if the environment is 2036 embedded within the U-Boot image, or in a separate 2037 flash sector. 2038 2039- CFG_MALLOC_LEN: 2040 Size of DRAM reserved for malloc() use. 2041 2042- CFG_BOOTM_LEN: 2043 Normally compressed uImages are limited to an 2044 uncompressed size of 8 MBytes. If this is not enough, 2045 you can define CFG_BOOTM_LEN in your board config file 2046 to adjust this setting to your needs. 2047 2048- CFG_BOOTMAPSZ: 2049 Maximum size of memory mapped by the startup code of 2050 the Linux kernel; all data that must be processed by 2051 the Linux kernel (bd_info, boot arguments, FDT blob if 2052 used) must be put below this limit, unless "bootm_low" 2053 enviroment variable is defined and non-zero. In such case 2054 all data for the Linux kernel must be between "bootm_low" 2055 and "bootm_low" + CFG_BOOTMAPSZ. 2056 2057- CFG_MAX_FLASH_BANKS: 2058 Max number of Flash memory banks 2059 2060- CFG_MAX_FLASH_SECT: 2061 Max number of sectors on a Flash chip 2062 2063- CFG_FLASH_ERASE_TOUT: 2064 Timeout for Flash erase operations (in ms) 2065 2066- CFG_FLASH_WRITE_TOUT: 2067 Timeout for Flash write operations (in ms) 2068 2069- CFG_FLASH_LOCK_TOUT 2070 Timeout for Flash set sector lock bit operation (in ms) 2071 2072- CFG_FLASH_UNLOCK_TOUT 2073 Timeout for Flash clear lock bits operation (in ms) 2074 2075- CFG_FLASH_PROTECTION 2076 If defined, hardware flash sectors protection is used 2077 instead of U-Boot software protection. 2078 2079- CFG_DIRECT_FLASH_TFTP: 2080 2081 Enable TFTP transfers directly to flash memory; 2082 without this option such a download has to be 2083 performed in two steps: (1) download to RAM, and (2) 2084 copy from RAM to flash. 2085 2086 The two-step approach is usually more reliable, since 2087 you can check if the download worked before you erase 2088 the flash, but in some situations (when system RAM is 2089 too limited to allow for a temporary copy of the 2090 downloaded image) this option may be very useful. 2091 2092- CFG_FLASH_CFI: 2093 Define if the flash driver uses extra elements in the 2094 common flash structure for storing flash geometry. 2095 2096- CONFIG_FLASH_CFI_DRIVER 2097 This option also enables the building of the cfi_flash driver 2098 in the drivers directory 2099 2100- CFG_FLASH_USE_BUFFER_WRITE 2101 Use buffered writes to flash. 2102 2103- CONFIG_FLASH_SPANSION_S29WS_N 2104 s29ws-n MirrorBit flash has non-standard addresses for buffered 2105 write commands. 2106 2107- CFG_FLASH_QUIET_TEST 2108 If this option is defined, the common CFI flash doesn't 2109 print it's warning upon not recognized FLASH banks. This 2110 is useful, if some of the configured banks are only 2111 optionally available. 2112 2113- CONFIG_FLASH_SHOW_PROGRESS 2114 If defined (must be an integer), print out countdown 2115 digits and dots. Recommended value: 45 (9..1) for 80 2116 column displays, 15 (3..1) for 40 column displays. 2117 2118- CFG_RX_ETH_BUFFER: 2119 Defines the number of Ethernet receive buffers. On some 2120 Ethernet controllers it is recommended to set this value 2121 to 8 or even higher (EEPRO100 or 405 EMAC), since all 2122 buffers can be full shortly after enabling the interface 2123 on high Ethernet traffic. 2124 Defaults to 4 if not defined. 2125 2126The following definitions that deal with the placement and management 2127of environment data (variable area); in general, we support the 2128following configurations: 2129 2130- CONFIG_ENV_IS_IN_FLASH: 2131 2132 Define this if the environment is in flash memory. 2133 2134 a) The environment occupies one whole flash sector, which is 2135 "embedded" in the text segment with the U-Boot code. This 2136 happens usually with "bottom boot sector" or "top boot 2137 sector" type flash chips, which have several smaller 2138 sectors at the start or the end. For instance, such a 2139 layout can have sector sizes of 8, 2x4, 16, Nx32 kB. In 2140 such a case you would place the environment in one of the 2141 4 kB sectors - with U-Boot code before and after it. With 2142 "top boot sector" type flash chips, you would put the 2143 environment in one of the last sectors, leaving a gap 2144 between U-Boot and the environment. 2145 2146 - CONFIG_ENV_OFFSET: 2147 2148 Offset of environment data (variable area) to the 2149 beginning of flash memory; for instance, with bottom boot 2150 type flash chips the second sector can be used: the offset 2151 for this sector is given here. 2152 2153 CONFIG_ENV_OFFSET is used relative to CFG_FLASH_BASE. 2154 2155 - CONFIG_ENV_ADDR: 2156 2157 This is just another way to specify the start address of 2158 the flash sector containing the environment (instead of 2159 CONFIG_ENV_OFFSET). 2160 2161 - CONFIG_ENV_SECT_SIZE: 2162 2163 Size of the sector containing the environment. 2164 2165 2166 b) Sometimes flash chips have few, equal sized, BIG sectors. 2167 In such a case you don't want to spend a whole sector for 2168 the environment. 2169 2170 - CONFIG_ENV_SIZE: 2171 2172 If you use this in combination with CONFIG_ENV_IS_IN_FLASH 2173 and CONFIG_ENV_SECT_SIZE, you can specify to use only a part 2174 of this flash sector for the environment. This saves 2175 memory for the RAM copy of the environment. 2176 2177 It may also save flash memory if you decide to use this 2178 when your environment is "embedded" within U-Boot code, 2179 since then the remainder of the flash sector could be used 2180 for U-Boot code. It should be pointed out that this is 2181 STRONGLY DISCOURAGED from a robustness point of view: 2182 updating the environment in flash makes it always 2183 necessary to erase the WHOLE sector. If something goes 2184 wrong before the contents has been restored from a copy in 2185 RAM, your target system will be dead. 2186 2187 - CONFIG_ENV_ADDR_REDUND 2188 CONFIG_ENV_SIZE_REDUND 2189 2190 These settings describe a second storage area used to hold 2191 a redundant copy of the environment data, so that there is 2192 a valid backup copy in case there is a power failure during 2193 a "saveenv" operation. 2194 2195BE CAREFUL! Any changes to the flash layout, and some changes to the 2196source code will make it necessary to adapt <board>/u-boot.lds* 2197accordingly! 2198 2199 2200- CONFIG_ENV_IS_IN_NVRAM: 2201 2202 Define this if you have some non-volatile memory device 2203 (NVRAM, battery buffered SRAM) which you want to use for the 2204 environment. 2205 2206 - CONFIG_ENV_ADDR: 2207 - CONFIG_ENV_SIZE: 2208 2209 These two #defines are used to determine the memory area you 2210 want to use for environment. It is assumed that this memory 2211 can just be read and written to, without any special 2212 provision. 2213 2214BE CAREFUL! The first access to the environment happens quite early 2215in U-Boot initalization (when we try to get the setting of for the 2216console baudrate). You *MUST* have mapped your NVRAM area then, or 2217U-Boot will hang. 2218 2219Please note that even with NVRAM we still use a copy of the 2220environment in RAM: we could work on NVRAM directly, but we want to 2221keep settings there always unmodified except somebody uses "saveenv" 2222to save the current settings. 2223 2224 2225- CONFIG_ENV_IS_IN_EEPROM: 2226 2227 Use this if you have an EEPROM or similar serial access 2228 device and a driver for it. 2229 2230 - CONFIG_ENV_OFFSET: 2231 - CONFIG_ENV_SIZE: 2232 2233 These two #defines specify the offset and size of the 2234 environment area within the total memory of your EEPROM. 2235 2236 - CFG_I2C_EEPROM_ADDR: 2237 If defined, specified the chip address of the EEPROM device. 2238 The default address is zero. 2239 2240 - CFG_EEPROM_PAGE_WRITE_BITS: 2241 If defined, the number of bits used to address bytes in a 2242 single page in the EEPROM device. A 64 byte page, for example 2243 would require six bits. 2244 2245 - CFG_EEPROM_PAGE_WRITE_DELAY_MS: 2246 If defined, the number of milliseconds to delay between 2247 page writes. The default is zero milliseconds. 2248 2249 - CFG_I2C_EEPROM_ADDR_LEN: 2250 The length in bytes of the EEPROM memory array address. Note 2251 that this is NOT the chip address length! 2252 2253 - CFG_I2C_EEPROM_ADDR_OVERFLOW: 2254 EEPROM chips that implement "address overflow" are ones 2255 like Catalyst 24WC04/08/16 which has 9/10/11 bits of 2256 address and the extra bits end up in the "chip address" bit 2257 slots. This makes a 24WC08 (1Kbyte) chip look like four 256 2258 byte chips. 2259 2260 Note that we consider the length of the address field to 2261 still be one byte because the extra address bits are hidden 2262 in the chip address. 2263 2264 - CFG_EEPROM_SIZE: 2265 The size in bytes of the EEPROM device. 2266 2267 2268- CONFIG_ENV_IS_IN_DATAFLASH: 2269 2270 Define this if you have a DataFlash memory device which you 2271 want to use for the environment. 2272 2273 - CONFIG_ENV_OFFSET: 2274 - CONFIG_ENV_ADDR: 2275 - CONFIG_ENV_SIZE: 2276 2277 These three #defines specify the offset and size of the 2278 environment area within the total memory of your DataFlash placed 2279 at the specified address. 2280 2281- CONFIG_ENV_IS_IN_NAND: 2282 2283 Define this if you have a NAND device which you want to use 2284 for the environment. 2285 2286 - CONFIG_ENV_OFFSET: 2287 - CONFIG_ENV_SIZE: 2288 2289 These two #defines specify the offset and size of the environment 2290 area within the first NAND device. 2291 2292 - CONFIG_ENV_OFFSET_REDUND 2293 2294 This setting describes a second storage area of CONFIG_ENV_SIZE 2295 size used to hold a redundant copy of the environment data, 2296 so that there is a valid backup copy in case there is a 2297 power failure during a "saveenv" operation. 2298 2299 Note: CONFIG_ENV_OFFSET and CONFIG_ENV_OFFSET_REDUND must be aligned 2300 to a block boundary, and CONFIG_ENV_SIZE must be a multiple of 2301 the NAND devices block size. 2302 2303- CFG_SPI_INIT_OFFSET 2304 2305 Defines offset to the initial SPI buffer area in DPRAM. The 2306 area is used at an early stage (ROM part) if the environment 2307 is configured to reside in the SPI EEPROM: We need a 520 byte 2308 scratch DPRAM area. It is used between the two initialization 2309 calls (spi_init_f() and spi_init_r()). A value of 0xB00 seems 2310 to be a good choice since it makes it far enough from the 2311 start of the data area as well as from the stack pointer. 2312 2313Please note that the environment is read-only until the monitor 2314has been relocated to RAM and a RAM copy of the environment has been 2315created; also, when using EEPROM you will have to use getenv_r() 2316until then to read environment variables. 2317 2318The environment is protected by a CRC32 checksum. Before the monitor 2319is relocated into RAM, as a result of a bad CRC you will be working 2320with the compiled-in default environment - *silently*!!! [This is 2321necessary, because the first environment variable we need is the 2322"baudrate" setting for the console - if we have a bad CRC, we don't 2323have any device yet where we could complain.] 2324 2325Note: once the monitor has been relocated, then it will complain if 2326the default environment is used; a new CRC is computed as soon as you 2327use the "saveenv" command to store a valid environment. 2328 2329- CFG_FAULT_ECHO_LINK_DOWN: 2330 Echo the inverted Ethernet link state to the fault LED. 2331 2332 Note: If this option is active, then CFG_FAULT_MII_ADDR 2333 also needs to be defined. 2334 2335- CFG_FAULT_MII_ADDR: 2336 MII address of the PHY to check for the Ethernet link state. 2337 2338- CFG_64BIT_VSPRINTF: 2339 Makes vsprintf (and all *printf functions) support printing 2340 of 64bit values by using the L quantifier 2341 2342- CFG_64BIT_STRTOUL: 2343 Adds simple_strtoull that returns a 64bit value 2344 2345Low Level (hardware related) configuration options: 2346--------------------------------------------------- 2347 2348- CFG_CACHELINE_SIZE: 2349 Cache Line Size of the CPU. 2350 2351- CFG_DEFAULT_IMMR: 2352 Default address of the IMMR after system reset. 2353 2354 Needed on some 8260 systems (MPC8260ADS, PQ2FADS-ZU, 2355 and RPXsuper) to be able to adjust the position of 2356 the IMMR register after a reset. 2357 2358- Floppy Disk Support: 2359 CFG_FDC_DRIVE_NUMBER 2360 2361 the default drive number (default value 0) 2362 2363 CFG_ISA_IO_STRIDE 2364 2365 defines the spacing between FDC chipset registers 2366 (default value 1) 2367 2368 CFG_ISA_IO_OFFSET 2369 2370 defines the offset of register from address. It 2371 depends on which part of the data bus is connected to 2372 the FDC chipset. (default value 0) 2373 2374 If CFG_ISA_IO_STRIDE CFG_ISA_IO_OFFSET and 2375 CFG_FDC_DRIVE_NUMBER are undefined, they take their 2376 default value. 2377 2378 if CFG_FDC_HW_INIT is defined, then the function 2379 fdc_hw_init() is called at the beginning of the FDC 2380 setup. fdc_hw_init() must be provided by the board 2381 source code. It is used to make hardware dependant 2382 initializations. 2383 2384- CFG_IMMR: Physical address of the Internal Memory. 2385 DO NOT CHANGE unless you know exactly what you're 2386 doing! (11-4) [MPC8xx/82xx systems only] 2387 2388- CFG_INIT_RAM_ADDR: 2389 2390 Start address of memory area that can be used for 2391 initial data and stack; please note that this must be 2392 writable memory that is working WITHOUT special 2393 initialization, i. e. you CANNOT use normal RAM which 2394 will become available only after programming the 2395 memory controller and running certain initialization 2396 sequences. 2397 2398 U-Boot uses the following memory types: 2399 - MPC8xx and MPC8260: IMMR (internal memory of the CPU) 2400 - MPC824X: data cache 2401 - PPC4xx: data cache 2402 2403- CFG_GBL_DATA_OFFSET: 2404 2405 Offset of the initial data structure in the memory 2406 area defined by CFG_INIT_RAM_ADDR. Usually 2407 CFG_GBL_DATA_OFFSET is chosen such that the initial 2408 data is located at the end of the available space 2409 (sometimes written as (CFG_INIT_RAM_END - 2410 CFG_INIT_DATA_SIZE), and the initial stack is just 2411 below that area (growing from (CFG_INIT_RAM_ADDR + 2412 CFG_GBL_DATA_OFFSET) downward. 2413 2414 Note: 2415 On the MPC824X (or other systems that use the data 2416 cache for initial memory) the address chosen for 2417 CFG_INIT_RAM_ADDR is basically arbitrary - it must 2418 point to an otherwise UNUSED address space between 2419 the top of RAM and the start of the PCI space. 2420 2421- CFG_SIUMCR: SIU Module Configuration (11-6) 2422 2423- CFG_SYPCR: System Protection Control (11-9) 2424 2425- CFG_TBSCR: Time Base Status and Control (11-26) 2426 2427- CFG_PISCR: Periodic Interrupt Status and Control (11-31) 2428 2429- CFG_PLPRCR: PLL, Low-Power, and Reset Control Register (15-30) 2430 2431- CFG_SCCR: System Clock and reset Control Register (15-27) 2432 2433- CFG_OR_TIMING_SDRAM: 2434 SDRAM timing 2435 2436- CFG_MAMR_PTA: 2437 periodic timer for refresh 2438 2439- CFG_DER: Debug Event Register (37-47) 2440 2441- FLASH_BASE0_PRELIM, FLASH_BASE1_PRELIM, CFG_REMAP_OR_AM, 2442 CFG_PRELIM_OR_AM, CFG_OR_TIMING_FLASH, CFG_OR0_REMAP, 2443 CFG_OR0_PRELIM, CFG_BR0_PRELIM, CFG_OR1_REMAP, CFG_OR1_PRELIM, 2444 CFG_BR1_PRELIM: 2445 Memory Controller Definitions: BR0/1 and OR0/1 (FLASH) 2446 2447- SDRAM_BASE2_PRELIM, SDRAM_BASE3_PRELIM, SDRAM_MAX_SIZE, 2448 CFG_OR_TIMING_SDRAM, CFG_OR2_PRELIM, CFG_BR2_PRELIM, 2449 CFG_OR3_PRELIM, CFG_BR3_PRELIM: 2450 Memory Controller Definitions: BR2/3 and OR2/3 (SDRAM) 2451 2452- CFG_MAMR_PTA, CFG_MPTPR_2BK_4K, CFG_MPTPR_1BK_4K, CFG_MPTPR_2BK_8K, 2453 CFG_MPTPR_1BK_8K, CFG_MAMR_8COL, CFG_MAMR_9COL: 2454 Machine Mode Register and Memory Periodic Timer 2455 Prescaler definitions (SDRAM timing) 2456 2457- CFG_I2C_UCODE_PATCH, CFG_I2C_DPMEM_OFFSET [0x1FC0]: 2458 enable I2C microcode relocation patch (MPC8xx); 2459 define relocation offset in DPRAM [DSP2] 2460 2461- CFG_SMC_UCODE_PATCH, CFG_SMC_DPMEM_OFFSET [0x1FC0]: 2462 enable SMC microcode relocation patch (MPC8xx); 2463 define relocation offset in DPRAM [SMC1] 2464 2465- CFG_SPI_UCODE_PATCH, CFG_SPI_DPMEM_OFFSET [0x1FC0]: 2466 enable SPI microcode relocation patch (MPC8xx); 2467 define relocation offset in DPRAM [SCC4] 2468 2469- CFG_USE_OSCCLK: 2470 Use OSCM clock mode on MBX8xx board. Be careful, 2471 wrong setting might damage your board. Read 2472 doc/README.MBX before setting this variable! 2473 2474- CFG_CPM_POST_WORD_ADDR: (MPC8xx, MPC8260 only) 2475 Offset of the bootmode word in DPRAM used by post 2476 (Power On Self Tests). This definition overrides 2477 #define'd default value in commproc.h resp. 2478 cpm_8260.h. 2479 2480- CFG_PCI_SLV_MEM_LOCAL, CFG_PCI_SLV_MEM_BUS, CFG_PICMR0_MASK_ATTRIB, 2481 CFG_PCI_MSTR0_LOCAL, CFG_PCIMSK0_MASK, CFG_PCI_MSTR1_LOCAL, 2482 CFG_PCIMSK1_MASK, CFG_PCI_MSTR_MEM_LOCAL, CFG_PCI_MSTR_MEM_BUS, 2483 CFG_CPU_PCI_MEM_START, CFG_PCI_MSTR_MEM_SIZE, CFG_POCMR0_MASK_ATTRIB, 2484 CFG_PCI_MSTR_MEMIO_LOCAL, CFG_PCI_MSTR_MEMIO_BUS, CPU_PCI_MEMIO_START, 2485 CFG_PCI_MSTR_MEMIO_SIZE, CFG_POCMR1_MASK_ATTRIB, CFG_PCI_MSTR_IO_LOCAL, 2486 CFG_PCI_MSTR_IO_BUS, CFG_CPU_PCI_IO_START, CFG_PCI_MSTR_IO_SIZE, 2487 CFG_POCMR2_MASK_ATTRIB: (MPC826x only) 2488 Overrides the default PCI memory map in cpu/mpc8260/pci.c if set. 2489 2490- CONFIG_SPD_EEPROM 2491 Get DDR timing information from an I2C EEPROM. Common 2492 with pluggable memory modules such as SODIMMs 2493 2494 SPD_EEPROM_ADDRESS 2495 I2C address of the SPD EEPROM 2496 2497- CFG_SPD_BUS_NUM 2498 If SPD EEPROM is on an I2C bus other than the first 2499 one, specify here. Note that the value must resolve 2500 to something your driver can deal with. 2501 2502- CFG_83XX_DDR_USES_CS0 2503 Only for 83xx systems. If specified, then DDR should 2504 be configured using CS0 and CS1 instead of CS2 and CS3. 2505 2506- CFG_83XX_DDR_USES_CS0 2507 Only for 83xx systems. If specified, then DDR should 2508 be configured using CS0 and CS1 instead of CS2 and CS3. 2509 2510- CONFIG_ETHER_ON_FEC[12] 2511 Define to enable FEC[12] on a 8xx series processor. 2512 2513- CONFIG_FEC[12]_PHY 2514 Define to the hardcoded PHY address which corresponds 2515 to the given FEC; i. e. 2516 #define CONFIG_FEC1_PHY 4 2517 means that the PHY with address 4 is connected to FEC1 2518 2519 When set to -1, means to probe for first available. 2520 2521- CONFIG_FEC[12]_PHY_NORXERR 2522 The PHY does not have a RXERR line (RMII only). 2523 (so program the FEC to ignore it). 2524 2525- CONFIG_RMII 2526 Enable RMII mode for all FECs. 2527 Note that this is a global option, we can't 2528 have one FEC in standard MII mode and another in RMII mode. 2529 2530- CONFIG_CRC32_VERIFY 2531 Add a verify option to the crc32 command. 2532 The syntax is: 2533 2534 => crc32 -v <address> <count> <crc32> 2535 2536 Where address/count indicate a memory area 2537 and crc32 is the correct crc32 which the 2538 area should have. 2539 2540- CONFIG_LOOPW 2541 Add the "loopw" memory command. This only takes effect if 2542 the memory commands are activated globally (CONFIG_CMD_MEM). 2543 2544- CONFIG_MX_CYCLIC 2545 Add the "mdc" and "mwc" memory commands. These are cyclic 2546 "md/mw" commands. 2547 Examples: 2548 2549 => mdc.b 10 4 500 2550 This command will print 4 bytes (10,11,12,13) each 500 ms. 2551 2552 => mwc.l 100 12345678 10 2553 This command will write 12345678 to address 100 all 10 ms. 2554 2555 This only takes effect if the memory commands are activated 2556 globally (CONFIG_CMD_MEM). 2557 2558- CONFIG_SKIP_LOWLEVEL_INIT 2559- CONFIG_SKIP_RELOCATE_UBOOT 2560 2561 [ARM only] If these variables are defined, then 2562 certain low level initializations (like setting up 2563 the memory controller) are omitted and/or U-Boot does 2564 not relocate itself into RAM. 2565 Normally these variables MUST NOT be defined. The 2566 only exception is when U-Boot is loaded (to RAM) by 2567 some other boot loader or by a debugger which 2568 performs these initializations itself. 2569 2570 2571Building the Software: 2572====================== 2573 2574Building U-Boot has been tested in several native build environments 2575and in many different cross environments. Of course we cannot support 2576all possibly existing versions of cross development tools in all 2577(potentially obsolete) versions. In case of tool chain problems we 2578recommend to use the ELDK (see http://www.denx.de/wiki/DULG/ELDK) 2579which is extensively used to build and test U-Boot. 2580 2581If you are not using a native environment, it is assumed that you 2582have GNU cross compiling tools available in your path. In this case, 2583you must set the environment variable CROSS_COMPILE in your shell. 2584Note that no changes to the Makefile or any other source files are 2585necessary. For example using the ELDK on a 4xx CPU, please enter: 2586 2587 $ CROSS_COMPILE=ppc_4xx- 2588 $ export CROSS_COMPILE 2589 2590U-Boot is intended to be simple to build. After installing the 2591sources you must configure U-Boot for one specific board type. This 2592is done by typing: 2593 2594 make NAME_config 2595 2596where "NAME_config" is the name of one of the existing configu- 2597rations; see the main Makefile for supported names. 2598 2599Note: for some board special configuration names may exist; check if 2600 additional information is available from the board vendor; for 2601 instance, the TQM823L systems are available without (standard) 2602 or with LCD support. You can select such additional "features" 2603 when choosing the configuration, i. e. 2604 2605 make TQM823L_config 2606 - will configure for a plain TQM823L, i. e. no LCD support 2607 2608 make TQM823L_LCD_config 2609 - will configure for a TQM823L with U-Boot console on LCD 2610 2611 etc. 2612 2613 2614Finally, type "make all", and you should get some working U-Boot 2615images ready for download to / installation on your system: 2616 2617- "u-boot.bin" is a raw binary image 2618- "u-boot" is an image in ELF binary format 2619- "u-boot.srec" is in Motorola S-Record format 2620 2621By default the build is performed locally and the objects are saved 2622in the source directory. One of the two methods can be used to change 2623this behavior and build U-Boot to some external directory: 2624 26251. Add O= to the make command line invocations: 2626 2627 make O=/tmp/build distclean 2628 make O=/tmp/build NAME_config 2629 make O=/tmp/build all 2630 26312. Set environment variable BUILD_DIR to point to the desired location: 2632 2633 export BUILD_DIR=/tmp/build 2634 make distclean 2635 make NAME_config 2636 make all 2637 2638Note that the command line "O=" setting overrides the BUILD_DIR environment 2639variable. 2640 2641 2642Please be aware that the Makefiles assume you are using GNU make, so 2643for instance on NetBSD you might need to use "gmake" instead of 2644native "make". 2645 2646 2647If the system board that you have is not listed, then you will need 2648to port U-Boot to your hardware platform. To do this, follow these 2649steps: 2650 26511. Add a new configuration option for your board to the toplevel 2652 "Makefile" and to the "MAKEALL" script, using the existing 2653 entries as examples. Note that here and at many other places 2654 boards and other names are listed in alphabetical sort order. Please 2655 keep this order. 26562. Create a new directory to hold your board specific code. Add any 2657 files you need. In your board directory, you will need at least 2658 the "Makefile", a "<board>.c", "flash.c" and "u-boot.lds". 26593. Create a new configuration file "include/configs/<board>.h" for 2660 your board 26613. If you're porting U-Boot to a new CPU, then also create a new 2662 directory to hold your CPU specific code. Add any files you need. 26634. Run "make <board>_config" with your new name. 26645. Type "make", and you should get a working "u-boot.srec" file 2665 to be installed on your target system. 26666. Debug and solve any problems that might arise. 2667 [Of course, this last step is much harder than it sounds.] 2668 2669 2670Testing of U-Boot Modifications, Ports to New Hardware, etc.: 2671============================================================== 2672 2673If you have modified U-Boot sources (for instance added a new board 2674or support for new devices, a new CPU, etc.) you are expected to 2675provide feedback to the other developers. The feedback normally takes 2676the form of a "patch", i. e. a context diff against a certain (latest 2677official or latest in the git repository) version of U-Boot sources. 2678 2679But before you submit such a patch, please verify that your modifi- 2680cation did not break existing code. At least make sure that *ALL* of 2681the supported boards compile WITHOUT ANY compiler warnings. To do so, 2682just run the "MAKEALL" script, which will configure and build U-Boot 2683for ALL supported system. Be warned, this will take a while. You can 2684select which (cross) compiler to use by passing a `CROSS_COMPILE' 2685environment variable to the script, i. e. to use the ELDK cross tools 2686you can type 2687 2688 CROSS_COMPILE=ppc_8xx- MAKEALL 2689 2690or to build on a native PowerPC system you can type 2691 2692 CROSS_COMPILE=' ' MAKEALL 2693 2694When using the MAKEALL script, the default behaviour is to build 2695U-Boot in the source directory. This location can be changed by 2696setting the BUILD_DIR environment variable. Also, for each target 2697built, the MAKEALL script saves two log files (<target>.ERR and 2698<target>.MAKEALL) in the <source dir>/LOG directory. This default 2699location can be changed by setting the MAKEALL_LOGDIR environment 2700variable. For example: 2701 2702 export BUILD_DIR=/tmp/build 2703 export MAKEALL_LOGDIR=/tmp/log 2704 CROSS_COMPILE=ppc_8xx- MAKEALL 2705 2706With the above settings build objects are saved in the /tmp/build, 2707log files are saved in the /tmp/log and the source tree remains clean 2708during the whole build process. 2709 2710 2711See also "U-Boot Porting Guide" below. 2712 2713 2714Monitor Commands - Overview: 2715============================ 2716 2717go - start application at address 'addr' 2718run - run commands in an environment variable 2719bootm - boot application image from memory 2720bootp - boot image via network using BootP/TFTP protocol 2721tftpboot- boot image via network using TFTP protocol 2722 and env variables "ipaddr" and "serverip" 2723 (and eventually "gatewayip") 2724rarpboot- boot image via network using RARP/TFTP protocol 2725diskboot- boot from IDE devicebootd - boot default, i.e., run 'bootcmd' 2726loads - load S-Record file over serial line 2727loadb - load binary file over serial line (kermit mode) 2728md - memory display 2729mm - memory modify (auto-incrementing) 2730nm - memory modify (constant address) 2731mw - memory write (fill) 2732cp - memory copy 2733cmp - memory compare 2734crc32 - checksum calculation 2735imd - i2c memory display 2736imm - i2c memory modify (auto-incrementing) 2737inm - i2c memory modify (constant address) 2738imw - i2c memory write (fill) 2739icrc32 - i2c checksum calculation 2740iprobe - probe to discover valid I2C chip addresses 2741iloop - infinite loop on address range 2742isdram - print SDRAM configuration information 2743sspi - SPI utility commands 2744base - print or set address offset 2745printenv- print environment variables 2746setenv - set environment variables 2747saveenv - save environment variables to persistent storage 2748protect - enable or disable FLASH write protection 2749erase - erase FLASH memory 2750flinfo - print FLASH memory information 2751bdinfo - print Board Info structure 2752iminfo - print header information for application image 2753coninfo - print console devices and informations 2754ide - IDE sub-system 2755loop - infinite loop on address range 2756loopw - infinite write loop on address range 2757mtest - simple RAM test 2758icache - enable or disable instruction cache 2759dcache - enable or disable data cache 2760reset - Perform RESET of the CPU 2761echo - echo args to console 2762version - print monitor version 2763help - print online help 2764? - alias for 'help' 2765 2766 2767Monitor Commands - Detailed Description: 2768======================================== 2769 2770TODO. 2771 2772For now: just type "help <command>". 2773 2774 2775Environment Variables: 2776====================== 2777 2778U-Boot supports user configuration using Environment Variables which 2779can be made persistent by saving to Flash memory. 2780 2781Environment Variables are set using "setenv", printed using 2782"printenv", and saved to Flash using "saveenv". Using "setenv" 2783without a value can be used to delete a variable from the 2784environment. As long as you don't save the environment you are 2785working with an in-memory copy. In case the Flash area containing the 2786environment is erased by accident, a default environment is provided. 2787 2788Some configuration options can be set using Environment Variables: 2789 2790 baudrate - see CONFIG_BAUDRATE 2791 2792 bootdelay - see CONFIG_BOOTDELAY 2793 2794 bootcmd - see CONFIG_BOOTCOMMAND 2795 2796 bootargs - Boot arguments when booting an RTOS image 2797 2798 bootfile - Name of the image to load with TFTP 2799 2800 bootm_low - Memory range available for image processing in the bootm 2801 command can be restricted. This variable is given as 2802 a hexadecimal number and defines lowest address allowed 2803 for use by the bootm command. See also "bootm_size" 2804 environment variable. Address defined by "bootm_low" is 2805 also the base of the initial memory mapping for the Linux 2806 kernel -- see the description of CFG_BOOTMAPSZ. 2807 2808 bootm_size - Memory range available for image processing in the bootm 2809 command can be restricted. This variable is given as 2810 a hexadecimal number and defines the size of the region 2811 allowed for use by the bootm command. See also "bootm_low" 2812 environment variable. 2813 2814 autoload - if set to "no" (any string beginning with 'n'), 2815 "bootp" will just load perform a lookup of the 2816 configuration from the BOOTP server, but not try to 2817 load any image using TFTP 2818 2819 autoscript - if set to "yes" commands like "loadb", "loady", 2820 "bootp", "tftpb", "rarpboot" and "nfs" will attempt 2821 to automatically run script images (by internally 2822 calling "autoscript"). 2823 2824 autoscript_uname - if script image is in a format (FIT) this 2825 variable is used to get script subimage unit name. 2826 2827 autostart - if set to "yes", an image loaded using the "bootp", 2828 "rarpboot", "tftpboot" or "diskboot" commands will 2829 be automatically started (by internally calling 2830 "bootm") 2831 2832 If set to "no", a standalone image passed to the 2833 "bootm" command will be copied to the load address 2834 (and eventually uncompressed), but NOT be started. 2835 This can be used to load and uncompress arbitrary 2836 data. 2837 2838 i2cfast - (PPC405GP|PPC405EP only) 2839 if set to 'y' configures Linux I2C driver for fast 2840 mode (400kHZ). This environment variable is used in 2841 initialization code. So, for changes to be effective 2842 it must be saved and board must be reset. 2843 2844 initrd_high - restrict positioning of initrd images: 2845 If this variable is not set, initrd images will be 2846 copied to the highest possible address in RAM; this 2847 is usually what you want since it allows for 2848 maximum initrd size. If for some reason you want to 2849 make sure that the initrd image is loaded below the 2850 CFG_BOOTMAPSZ limit, you can set this environment 2851 variable to a value of "no" or "off" or "0". 2852 Alternatively, you can set it to a maximum upper 2853 address to use (U-Boot will still check that it 2854 does not overwrite the U-Boot stack and data). 2855 2856 For instance, when you have a system with 16 MB 2857 RAM, and want to reserve 4 MB from use by Linux, 2858 you can do this by adding "mem=12M" to the value of 2859 the "bootargs" variable. However, now you must make 2860 sure that the initrd image is placed in the first 2861 12 MB as well - this can be done with 2862 2863 setenv initrd_high 00c00000 2864 2865 If you set initrd_high to 0xFFFFFFFF, this is an 2866 indication to U-Boot that all addresses are legal 2867 for the Linux kernel, including addresses in flash 2868 memory. In this case U-Boot will NOT COPY the 2869 ramdisk at all. This may be useful to reduce the 2870 boot time on your system, but requires that this 2871 feature is supported by your Linux kernel. 2872 2873 ipaddr - IP address; needed for tftpboot command 2874 2875 loadaddr - Default load address for commands like "bootp", 2876 "rarpboot", "tftpboot", "loadb" or "diskboot" 2877 2878 loads_echo - see CONFIG_LOADS_ECHO 2879 2880 serverip - TFTP server IP address; needed for tftpboot command 2881 2882 bootretry - see CONFIG_BOOT_RETRY_TIME 2883 2884 bootdelaykey - see CONFIG_AUTOBOOT_DELAY_STR 2885 2886 bootstopkey - see CONFIG_AUTOBOOT_STOP_STR 2887 2888 ethprime - When CONFIG_NET_MULTI is enabled controls which 2889 interface is used first. 2890 2891 ethact - When CONFIG_NET_MULTI is enabled controls which 2892 interface is currently active. For example you 2893 can do the following 2894 2895 => setenv ethact FEC ETHERNET 2896 => ping 192.168.0.1 # traffic sent on FEC ETHERNET 2897 => setenv ethact SCC ETHERNET 2898 => ping 10.0.0.1 # traffic sent on SCC ETHERNET 2899 2900 ethrotate - When set to "no" U-Boot does not go through all 2901 available network interfaces. 2902 It just stays at the currently selected interface. 2903 2904 netretry - When set to "no" each network operation will 2905 either succeed or fail without retrying. 2906 When set to "once" the network operation will 2907 fail when all the available network interfaces 2908 are tried once without success. 2909 Useful on scripts which control the retry operation 2910 themselves. 2911 2912 npe_ucode - see CONFIG_IXP4XX_NPE_EXT_UCOD 2913 if set load address for the NPE microcode 2914 2915 tftpsrcport - If this is set, the value is used for TFTP's 2916 UDP source port. 2917 2918 tftpdstport - If this is set, the value is used for TFTP's UDP 2919 destination port instead of the Well Know Port 69. 2920 2921 vlan - When set to a value < 4095 the traffic over 2922 Ethernet is encapsulated/received over 802.1q 2923 VLAN tagged frames. 2924 2925The following environment variables may be used and automatically 2926updated by the network boot commands ("bootp" and "rarpboot"), 2927depending the information provided by your boot server: 2928 2929 bootfile - see above 2930 dnsip - IP address of your Domain Name Server 2931 dnsip2 - IP address of your secondary Domain Name Server 2932 gatewayip - IP address of the Gateway (Router) to use 2933 hostname - Target hostname 2934 ipaddr - see above 2935 netmask - Subnet Mask 2936 rootpath - Pathname of the root filesystem on the NFS server 2937 serverip - see above 2938 2939 2940There are two special Environment Variables: 2941 2942 serial# - contains hardware identification information such 2943 as type string and/or serial number 2944 ethaddr - Ethernet address 2945 2946These variables can be set only once (usually during manufacturing of 2947the board). U-Boot refuses to delete or overwrite these variables 2948once they have been set once. 2949 2950 2951Further special Environment Variables: 2952 2953 ver - Contains the U-Boot version string as printed 2954 with the "version" command. This variable is 2955 readonly (see CONFIG_VERSION_VARIABLE). 2956 2957 2958Please note that changes to some configuration parameters may take 2959only effect after the next boot (yes, that's just like Windoze :-). 2960 2961 2962Command Line Parsing: 2963===================== 2964 2965There are two different command line parsers available with U-Boot: 2966the old "simple" one, and the much more powerful "hush" shell: 2967 2968Old, simple command line parser: 2969-------------------------------- 2970 2971- supports environment variables (through setenv / saveenv commands) 2972- several commands on one line, separated by ';' 2973- variable substitution using "... ${name} ..." syntax 2974- special characters ('$', ';') can be escaped by prefixing with '\', 2975 for example: 2976 setenv bootcmd bootm \${address} 2977- You can also escape text by enclosing in single apostrophes, for example: 2978 setenv addip 'setenv bootargs $bootargs ip=$ipaddr:$serverip:$gatewayip:$netmask:$hostname::off' 2979 2980Hush shell: 2981----------- 2982 2983- similar to Bourne shell, with control structures like 2984 if...then...else...fi, for...do...done; while...do...done, 2985 until...do...done, ... 2986- supports environment ("global") variables (through setenv / saveenv 2987 commands) and local shell variables (through standard shell syntax 2988 "name=value"); only environment variables can be used with "run" 2989 command 2990 2991General rules: 2992-------------- 2993 2994(1) If a command line (or an environment variable executed by a "run" 2995 command) contains several commands separated by semicolon, and 2996 one of these commands fails, then the remaining commands will be 2997 executed anyway. 2998 2999(2) If you execute several variables with one call to run (i. e. 3000 calling run with a list of variables as arguments), any failing 3001 command will cause "run" to terminate, i. e. the remaining 3002 variables are not executed. 3003 3004Note for Redundant Ethernet Interfaces: 3005======================================= 3006 3007Some boards come with redundant Ethernet interfaces; U-Boot supports 3008such configurations and is capable of automatic selection of a 3009"working" interface when needed. MAC assignment works as follows: 3010 3011Network interfaces are numbered eth0, eth1, eth2, ... Corresponding 3012MAC addresses can be stored in the environment as "ethaddr" (=>eth0), 3013"eth1addr" (=>eth1), "eth2addr", ... 3014 3015If the network interface stores some valid MAC address (for instance 3016in SROM), this is used as default address if there is NO correspon- 3017ding setting in the environment; if the corresponding environment 3018variable is set, this overrides the settings in the card; that means: 3019 3020o If the SROM has a valid MAC address, and there is no address in the 3021 environment, the SROM's address is used. 3022 3023o If there is no valid address in the SROM, and a definition in the 3024 environment exists, then the value from the environment variable is 3025 used. 3026 3027o If both the SROM and the environment contain a MAC address, and 3028 both addresses are the same, this MAC address is used. 3029 3030o If both the SROM and the environment contain a MAC address, and the 3031 addresses differ, the value from the environment is used and a 3032 warning is printed. 3033 3034o If neither SROM nor the environment contain a MAC address, an error 3035 is raised. 3036 3037 3038Image Formats: 3039============== 3040 3041U-Boot is capable of booting (and performing other auxiliary operations on) 3042images in two formats: 3043 3044New uImage format (FIT) 3045----------------------- 3046 3047Flexible and powerful format based on Flattened Image Tree -- FIT (similar 3048to Flattened Device Tree). It allows the use of images with multiple 3049components (several kernels, ramdisks, etc.), with contents protected by 3050SHA1, MD5 or CRC32. More details are found in the doc/uImage.FIT directory. 3051 3052 3053Old uImage format 3054----------------- 3055 3056Old image format is based on binary files which can be basically anything, 3057preceded by a special header; see the definitions in include/image.h for 3058details; basically, the header defines the following image properties: 3059 3060* Target Operating System (Provisions for OpenBSD, NetBSD, FreeBSD, 3061 4.4BSD, Linux, SVR4, Esix, Solaris, Irix, SCO, Dell, NCR, VxWorks, 3062 LynxOS, pSOS, QNX, RTEMS, INTEGRITY; 3063 Currently supported: Linux, NetBSD, VxWorks, QNX, RTEMS, LynxOS, 3064 INTEGRITY). 3065* Target CPU Architecture (Provisions for Alpha, ARM, AVR32, Intel x86, 3066 IA64, MIPS, NIOS, PowerPC, IBM S390, SuperH, Sparc, Sparc 64 Bit; 3067 Currently supported: ARM, AVR32, Intel x86, MIPS, NIOS, PowerPC). 3068* Compression Type (uncompressed, gzip, bzip2) 3069* Load Address 3070* Entry Point 3071* Image Name 3072* Image Timestamp 3073 3074The header is marked by a special Magic Number, and both the header 3075and the data portions of the image are secured against corruption by 3076CRC32 checksums. 3077 3078 3079Linux Support: 3080============== 3081 3082Although U-Boot should support any OS or standalone application 3083easily, the main focus has always been on Linux during the design of 3084U-Boot. 3085 3086U-Boot includes many features that so far have been part of some 3087special "boot loader" code within the Linux kernel. Also, any 3088"initrd" images to be used are no longer part of one big Linux image; 3089instead, kernel and "initrd" are separate images. This implementation 3090serves several purposes: 3091 3092- the same features can be used for other OS or standalone 3093 applications (for instance: using compressed images to reduce the 3094 Flash memory footprint) 3095 3096- it becomes much easier to port new Linux kernel versions because 3097 lots of low-level, hardware dependent stuff are done by U-Boot 3098 3099- the same Linux kernel image can now be used with different "initrd" 3100 images; of course this also means that different kernel images can 3101 be run with the same "initrd". This makes testing easier (you don't 3102 have to build a new "zImage.initrd" Linux image when you just 3103 change a file in your "initrd"). Also, a field-upgrade of the 3104 software is easier now. 3105 3106 3107Linux HOWTO: 3108============ 3109 3110Porting Linux to U-Boot based systems: 3111--------------------------------------- 3112 3113U-Boot cannot save you from doing all the necessary modifications to 3114configure the Linux device drivers for use with your target hardware 3115(no, we don't intend to provide a full virtual machine interface to 3116Linux :-). 3117 3118But now you can ignore ALL boot loader code (in arch/ppc/mbxboot). 3119 3120Just make sure your machine specific header file (for instance 3121include/asm-ppc/tqm8xx.h) includes the same definition of the Board 3122Information structure as we define in include/asm-<arch>/u-boot.h, 3123and make sure that your definition of IMAP_ADDR uses the same value 3124as your U-Boot configuration in CFG_IMMR. 3125 3126 3127Configuring the Linux kernel: 3128----------------------------- 3129 3130No specific requirements for U-Boot. Make sure you have some root 3131device (initial ramdisk, NFS) for your target system. 3132 3133 3134Building a Linux Image: 3135----------------------- 3136 3137With U-Boot, "normal" build targets like "zImage" or "bzImage" are 3138not used. If you use recent kernel source, a new build target 3139"uImage" will exist which automatically builds an image usable by 3140U-Boot. Most older kernels also have support for a "pImage" target, 3141which was introduced for our predecessor project PPCBoot and uses a 3142100% compatible format. 3143 3144Example: 3145 3146 make TQM850L_config 3147 make oldconfig 3148 make dep 3149 make uImage 3150 3151The "uImage" build target uses a special tool (in 'tools/mkimage') to 3152encapsulate a compressed Linux kernel image with header information, 3153CRC32 checksum etc. for use with U-Boot. This is what we are doing: 3154 3155* build a standard "vmlinux" kernel image (in ELF binary format): 3156 3157* convert the kernel into a raw binary image: 3158 3159 ${CROSS_COMPILE}-objcopy -O binary \ 3160 -R .note -R .comment \ 3161 -S vmlinux linux.bin 3162 3163* compress the binary image: 3164 3165 gzip -9 linux.bin 3166 3167* package compressed binary image for U-Boot: 3168 3169 mkimage -A ppc -O linux -T kernel -C gzip \ 3170 -a 0 -e 0 -n "Linux Kernel Image" \ 3171 -d linux.bin.gz uImage 3172 3173 3174The "mkimage" tool can also be used to create ramdisk images for use 3175with U-Boot, either separated from the Linux kernel image, or 3176combined into one file. "mkimage" encapsulates the images with a 64 3177byte header containing information about target architecture, 3178operating system, image type, compression method, entry points, time 3179stamp, CRC32 checksums, etc. 3180 3181"mkimage" can be called in two ways: to verify existing images and 3182print the header information, or to build new images. 3183 3184In the first form (with "-l" option) mkimage lists the information 3185contained in the header of an existing U-Boot image; this includes 3186checksum verification: 3187 3188 tools/mkimage -l image 3189 -l ==> list image header information 3190 3191The second form (with "-d" option) is used to build a U-Boot image 3192from a "data file" which is used as image payload: 3193 3194 tools/mkimage -A arch -O os -T type -C comp -a addr -e ep \ 3195 -n name -d data_file image 3196 -A ==> set architecture to 'arch' 3197 -O ==> set operating system to 'os' 3198 -T ==> set image type to 'type' 3199 -C ==> set compression type 'comp' 3200 -a ==> set load address to 'addr' (hex) 3201 -e ==> set entry point to 'ep' (hex) 3202 -n ==> set image name to 'name' 3203 -d ==> use image data from 'datafile' 3204 3205Right now, all Linux kernels for PowerPC systems use the same load 3206address (0x00000000), but the entry point address depends on the 3207kernel version: 3208 3209- 2.2.x kernels have the entry point at 0x0000000C, 3210- 2.3.x and later kernels have the entry point at 0x00000000. 3211 3212So a typical call to build a U-Boot image would read: 3213 3214 -> tools/mkimage -n '2.4.4 kernel for TQM850L' \ 3215 > -A ppc -O linux -T kernel -C gzip -a 0 -e 0 \ 3216 > -d /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/ppc/coffboot/vmlinux.gz \ 3217 > examples/uImage.TQM850L 3218 Image Name: 2.4.4 kernel for TQM850L 3219 Created: Wed Jul 19 02:34:59 2000 3220 Image Type: PowerPC Linux Kernel Image (gzip compressed) 3221 Data Size: 335725 Bytes = 327.86 kB = 0.32 MB 3222 Load Address: 0x00000000 3223 Entry Point: 0x00000000 3224 3225To verify the contents of the image (or check for corruption): 3226 3227 -> tools/mkimage -l examples/uImage.TQM850L 3228 Image Name: 2.4.4 kernel for TQM850L 3229 Created: Wed Jul 19 02:34:59 2000 3230 Image Type: PowerPC Linux Kernel Image (gzip compressed) 3231 Data Size: 335725 Bytes = 327.86 kB = 0.32 MB 3232 Load Address: 0x00000000 3233 Entry Point: 0x00000000 3234 3235NOTE: for embedded systems where boot time is critical you can trade 3236speed for memory and install an UNCOMPRESSED image instead: this 3237needs more space in Flash, but boots much faster since it does not 3238need to be uncompressed: 3239 3240 -> gunzip /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/ppc/coffboot/vmlinux.gz 3241 -> tools/mkimage -n '2.4.4 kernel for TQM850L' \ 3242 > -A ppc -O linux -T kernel -C none -a 0 -e 0 \ 3243 > -d /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/ppc/coffboot/vmlinux \ 3244 > examples/uImage.TQM850L-uncompressed 3245 Image Name: 2.4.4 kernel for TQM850L 3246 Created: Wed Jul 19 02:34:59 2000 3247 Image Type: PowerPC Linux Kernel Image (uncompressed) 3248 Data Size: 792160 Bytes = 773.59 kB = 0.76 MB 3249 Load Address: 0x00000000 3250 Entry Point: 0x00000000 3251 3252 3253Similar you can build U-Boot images from a 'ramdisk.image.gz' file 3254when your kernel is intended to use an initial ramdisk: 3255 3256 -> tools/mkimage -n 'Simple Ramdisk Image' \ 3257 > -A ppc -O linux -T ramdisk -C gzip \ 3258 > -d /LinuxPPC/images/SIMPLE-ramdisk.image.gz examples/simple-initrd 3259 Image Name: Simple Ramdisk Image 3260 Created: Wed Jan 12 14:01:50 2000 3261 Image Type: PowerPC Linux RAMDisk Image (gzip compressed) 3262 Data Size: 566530 Bytes = 553.25 kB = 0.54 MB 3263 Load Address: 0x00000000 3264 Entry Point: 0x00000000 3265 3266 3267Installing a Linux Image: 3268------------------------- 3269 3270To downloading a U-Boot image over the serial (console) interface, 3271you must convert the image to S-Record format: 3272 3273 objcopy -I binary -O srec examples/image examples/image.srec 3274 3275The 'objcopy' does not understand the information in the U-Boot 3276image header, so the resulting S-Record file will be relative to 3277address 0x00000000. To load it to a given address, you need to 3278specify the target address as 'offset' parameter with the 'loads' 3279command. 3280 3281Example: install the image to address 0x40100000 (which on the 3282TQM8xxL is in the first Flash bank): 3283 3284 => erase 40100000 401FFFFF 3285 3286 .......... done 3287 Erased 8 sectors 3288 3289 => loads 40100000 3290 ## Ready for S-Record download ... 3291 ~>examples/image.srec 3292 1 2 3 4 5 6 7 8 9 10 11 12 13 ... 3293 ... 3294 15989 15990 15991 15992 3295 [file transfer complete] 3296 [connected] 3297 ## Start Addr = 0x00000000 3298 3299 3300You can check the success of the download using the 'iminfo' command; 3301this includes a checksum verification so you can be sure no data 3302corruption happened: 3303 3304 => imi 40100000 3305 3306 ## Checking Image at 40100000 ... 3307 Image Name: 2.2.13 for initrd on TQM850L 3308 Image Type: PowerPC Linux Kernel Image (gzip compressed) 3309 Data Size: 335725 Bytes = 327 kB = 0 MB 3310 Load Address: 00000000 3311 Entry Point: 0000000c 3312 Verifying Checksum ... OK 3313 3314 3315Boot Linux: 3316----------- 3317 3318The "bootm" command is used to boot an application that is stored in 3319memory (RAM or Flash). In case of a Linux kernel image, the contents 3320of the "bootargs" environment variable is passed to the kernel as 3321parameters. You can check and modify this variable using the 3322"printenv" and "setenv" commands: 3323 3324 3325 => printenv bootargs 3326 bootargs=root=/dev/ram 3327 3328 => setenv bootargs root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2 3329 3330 => printenv bootargs 3331 bootargs=root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2 3332 3333 => bootm 40020000 3334 ## Booting Linux kernel at 40020000 ... 3335 Image Name: 2.2.13 for NFS on TQM850L 3336 Image Type: PowerPC Linux Kernel Image (gzip compressed) 3337 Data Size: 381681 Bytes = 372 kB = 0 MB 3338 Load Address: 00000000 3339 Entry Point: 0000000c 3340 Verifying Checksum ... OK 3341 Uncompressing Kernel Image ... OK 3342 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 3343 Boot arguments: root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2 3344 time_init: decrementer frequency = 187500000/60 3345 Calibrating delay loop... 49.77 BogoMIPS 3346 Memory: 15208k available (700k kernel code, 444k data, 32k init) [c0000000,c1000000] 3347 ... 3348 3349If you want to boot a Linux kernel with initial RAM disk, you pass 3350the memory addresses of both the kernel and the initrd image (PPBCOOT 3351format!) to the "bootm" command: 3352 3353 => imi 40100000 40200000 3354 3355 ## Checking Image at 40100000 ... 3356 Image Name: 2.2.13 for initrd on TQM850L 3357 Image Type: PowerPC Linux Kernel Image (gzip compressed) 3358 Data Size: 335725 Bytes = 327 kB = 0 MB 3359 Load Address: 00000000 3360 Entry Point: 0000000c 3361 Verifying Checksum ... OK 3362 3363 ## Checking Image at 40200000 ... 3364 Image Name: Simple Ramdisk Image 3365 Image Type: PowerPC Linux RAMDisk Image (gzip compressed) 3366 Data Size: 566530 Bytes = 553 kB = 0 MB 3367 Load Address: 00000000 3368 Entry Point: 00000000 3369 Verifying Checksum ... OK 3370 3371 => bootm 40100000 40200000 3372 ## Booting Linux kernel at 40100000 ... 3373 Image Name: 2.2.13 for initrd on TQM850L 3374 Image Type: PowerPC Linux Kernel Image (gzip compressed) 3375 Data Size: 335725 Bytes = 327 kB = 0 MB 3376 Load Address: 00000000 3377 Entry Point: 0000000c 3378 Verifying Checksum ... OK 3379 Uncompressing Kernel Image ... OK 3380 ## Loading RAMDisk Image at 40200000 ... 3381 Image Name: Simple Ramdisk Image 3382 Image Type: PowerPC Linux RAMDisk Image (gzip compressed) 3383 Data Size: 566530 Bytes = 553 kB = 0 MB 3384 Load Address: 00000000 3385 Entry Point: 00000000 3386 Verifying Checksum ... OK 3387 Loading Ramdisk ... OK 3388 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 3389 Boot arguments: root=/dev/ram 3390 time_init: decrementer frequency = 187500000/60 3391 Calibrating delay loop... 49.77 BogoMIPS 3392 ... 3393 RAMDISK: Compressed image found at block 0 3394 VFS: Mounted root (ext2 filesystem). 3395 3396 bash# 3397 3398Boot Linux and pass a flat device tree: 3399----------- 3400 3401First, U-Boot must be compiled with the appropriate defines. See the section 3402titled "Linux Kernel Interface" above for a more in depth explanation. The 3403following is an example of how to start a kernel and pass an updated 3404flat device tree: 3405 3406=> print oftaddr 3407oftaddr=0x300000 3408=> print oft 3409oft=oftrees/mpc8540ads.dtb 3410=> tftp $oftaddr $oft 3411Speed: 1000, full duplex 3412Using TSEC0 device 3413TFTP from server 192.168.1.1; our IP address is 192.168.1.101 3414Filename 'oftrees/mpc8540ads.dtb'. 3415Load address: 0x300000 3416Loading: # 3417done 3418Bytes transferred = 4106 (100a hex) 3419=> tftp $loadaddr $bootfile 3420Speed: 1000, full duplex 3421Using TSEC0 device 3422TFTP from server 192.168.1.1; our IP address is 192.168.1.2 3423Filename 'uImage'. 3424Load address: 0x200000 3425Loading:############ 3426done 3427Bytes transferred = 1029407 (fb51f hex) 3428=> print loadaddr 3429loadaddr=200000 3430=> print oftaddr 3431oftaddr=0x300000 3432=> bootm $loadaddr - $oftaddr 3433## Booting image at 00200000 ... 3434 Image Name: Linux-2.6.17-dirty 3435 Image Type: PowerPC Linux Kernel Image (gzip compressed) 3436 Data Size: 1029343 Bytes = 1005.2 kB 3437 Load Address: 00000000 3438 Entry Point: 00000000 3439 Verifying Checksum ... OK 3440 Uncompressing Kernel Image ... OK 3441Booting using flat device tree at 0x300000 3442Using MPC85xx ADS machine description 3443Memory CAM mapping: CAM0=256Mb, CAM1=256Mb, CAM2=0Mb residual: 0Mb 3444[snip] 3445 3446 3447More About U-Boot Image Types: 3448------------------------------ 3449 3450U-Boot supports the following image types: 3451 3452 "Standalone Programs" are directly runnable in the environment 3453 provided by U-Boot; it is expected that (if they behave 3454 well) you can continue to work in U-Boot after return from 3455 the Standalone Program. 3456 "OS Kernel Images" are usually images of some Embedded OS which 3457 will take over control completely. Usually these programs 3458 will install their own set of exception handlers, device 3459 drivers, set up the MMU, etc. - this means, that you cannot 3460 expect to re-enter U-Boot except by resetting the CPU. 3461 "RAMDisk Images" are more or less just data blocks, and their 3462 parameters (address, size) are passed to an OS kernel that is 3463 being started. 3464 "Multi-File Images" contain several images, typically an OS 3465 (Linux) kernel image and one or more data images like 3466 RAMDisks. This construct is useful for instance when you want 3467 to boot over the network using BOOTP etc., where the boot 3468 server provides just a single image file, but you want to get 3469 for instance an OS kernel and a RAMDisk image. 3470 3471 "Multi-File Images" start with a list of image sizes, each 3472 image size (in bytes) specified by an "uint32_t" in network 3473 byte order. This list is terminated by an "(uint32_t)0". 3474 Immediately after the terminating 0 follow the images, one by 3475 one, all aligned on "uint32_t" boundaries (size rounded up to 3476 a multiple of 4 bytes). 3477 3478 "Firmware Images" are binary images containing firmware (like 3479 U-Boot or FPGA images) which usually will be programmed to 3480 flash memory. 3481 3482 "Script files" are command sequences that will be executed by 3483 U-Boot's command interpreter; this feature is especially 3484 useful when you configure U-Boot to use a real shell (hush) 3485 as command interpreter. 3486 3487 3488Standalone HOWTO: 3489================= 3490 3491One of the features of U-Boot is that you can dynamically load and 3492run "standalone" applications, which can use some resources of 3493U-Boot like console I/O functions or interrupt services. 3494 3495Two simple examples are included with the sources: 3496 3497"Hello World" Demo: 3498------------------- 3499 3500'examples/hello_world.c' contains a small "Hello World" Demo 3501application; it is automatically compiled when you build U-Boot. 3502It's configured to run at address 0x00040004, so you can play with it 3503like that: 3504 3505 => loads 3506 ## Ready for S-Record download ... 3507 ~>examples/hello_world.srec 3508 1 2 3 4 5 6 7 8 9 10 11 ... 3509 [file transfer complete] 3510 [connected] 3511 ## Start Addr = 0x00040004 3512 3513 => go 40004 Hello World! This is a test. 3514 ## Starting application at 0x00040004 ... 3515 Hello World 3516 argc = 7 3517 argv[0] = "40004" 3518 argv[1] = "Hello" 3519 argv[2] = "World!" 3520 argv[3] = "This" 3521 argv[4] = "is" 3522 argv[5] = "a" 3523 argv[6] = "test." 3524 argv[7] = "<NULL>" 3525 Hit any key to exit ... 3526 3527 ## Application terminated, rc = 0x0 3528 3529Another example, which demonstrates how to register a CPM interrupt 3530handler with the U-Boot code, can be found in 'examples/timer.c'. 3531Here, a CPM timer is set up to generate an interrupt every second. 3532The interrupt service routine is trivial, just printing a '.' 3533character, but this is just a demo program. The application can be 3534controlled by the following keys: 3535 3536 ? - print current values og the CPM Timer registers 3537 b - enable interrupts and start timer 3538 e - stop timer and disable interrupts 3539 q - quit application 3540 3541 => loads 3542 ## Ready for S-Record download ... 3543 ~>examples/timer.srec 3544 1 2 3 4 5 6 7 8 9 10 11 ... 3545 [file transfer complete] 3546 [connected] 3547 ## Start Addr = 0x00040004 3548 3549 => go 40004 3550 ## Starting application at 0x00040004 ... 3551 TIMERS=0xfff00980 3552 Using timer 1 3553 tgcr @ 0xfff00980, tmr @ 0xfff00990, trr @ 0xfff00994, tcr @ 0xfff00998, tcn @ 0xfff0099c, ter @ 0xfff009b0 3554 3555Hit 'b': 3556 [q, b, e, ?] Set interval 1000000 us 3557 Enabling timer 3558Hit '?': 3559 [q, b, e, ?] ........ 3560 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0xef6, ter=0x0 3561Hit '?': 3562 [q, b, e, ?] . 3563 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x2ad4, ter=0x0 3564Hit '?': 3565 [q, b, e, ?] . 3566 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x1efc, ter=0x0 3567Hit '?': 3568 [q, b, e, ?] . 3569 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x169d, ter=0x0 3570Hit 'e': 3571 [q, b, e, ?] ...Stopping timer 3572Hit 'q': 3573 [q, b, e, ?] ## Application terminated, rc = 0x0 3574 3575 3576Minicom warning: 3577================ 3578 3579Over time, many people have reported problems when trying to use the 3580"minicom" terminal emulation program for serial download. I (wd) 3581consider minicom to be broken, and recommend not to use it. Under 3582Unix, I recommend to use C-Kermit for general purpose use (and 3583especially for kermit binary protocol download ("loadb" command), and 3584use "cu" for S-Record download ("loads" command). 3585 3586Nevertheless, if you absolutely want to use it try adding this 3587configuration to your "File transfer protocols" section: 3588 3589 Name Program Name U/D FullScr IO-Red. Multi 3590 X kermit /usr/bin/kermit -i -l %l -s Y U Y N N 3591 Y kermit /usr/bin/kermit -i -l %l -r N D Y N N 3592 3593 3594NetBSD Notes: 3595============= 3596 3597Starting at version 0.9.2, U-Boot supports NetBSD both as host 3598(build U-Boot) and target system (boots NetBSD/mpc8xx). 3599 3600Building requires a cross environment; it is known to work on 3601NetBSD/i386 with the cross-powerpc-netbsd-1.3 package (you will also 3602need gmake since the Makefiles are not compatible with BSD make). 3603Note that the cross-powerpc package does not install include files; 3604attempting to build U-Boot will fail because <machine/ansi.h> is 3605missing. This file has to be installed and patched manually: 3606 3607 # cd /usr/pkg/cross/powerpc-netbsd/include 3608 # mkdir powerpc 3609 # ln -s powerpc machine 3610 # cp /usr/src/sys/arch/powerpc/include/ansi.h powerpc/ansi.h 3611 # ${EDIT} powerpc/ansi.h ## must remove __va_list, _BSD_VA_LIST 3612 3613Native builds *don't* work due to incompatibilities between native 3614and U-Boot include files. 3615 3616Booting assumes that (the first part of) the image booted is a 3617stage-2 loader which in turn loads and then invokes the kernel 3618proper. Loader sources will eventually appear in the NetBSD source 3619tree (probably in sys/arc/mpc8xx/stand/u-boot_stage2/); in the 3620meantime, see ftp://ftp.denx.de/pub/u-boot/ppcboot_stage2.tar.gz 3621 3622 3623Implementation Internals: 3624========================= 3625 3626The following is not intended to be a complete description of every 3627implementation detail. However, it should help to understand the 3628inner workings of U-Boot and make it easier to port it to custom 3629hardware. 3630 3631 3632Initial Stack, Global Data: 3633--------------------------- 3634 3635The implementation of U-Boot is complicated by the fact that U-Boot 3636starts running out of ROM (flash memory), usually without access to 3637system RAM (because the memory controller is not initialized yet). 3638This means that we don't have writable Data or BSS segments, and BSS 3639is not initialized as zero. To be able to get a C environment working 3640at all, we have to allocate at least a minimal stack. Implementation 3641options for this are defined and restricted by the CPU used: Some CPU 3642models provide on-chip memory (like the IMMR area on MPC8xx and 3643MPC826x processors), on others (parts of) the data cache can be 3644locked as (mis-) used as memory, etc. 3645 3646 Chris Hallinan posted a good summary of these issues to the 3647 u-boot-users mailing list: 3648 3649 Subject: RE: [U-Boot-Users] RE: More On Memory Bank x (nothingness)? 3650 From: "Chris Hallinan" <clh@net1plus.com> 3651 Date: Mon, 10 Feb 2003 16:43:46 -0500 (22:43 MET) 3652 ... 3653 3654 Correct me if I'm wrong, folks, but the way I understand it 3655 is this: Using DCACHE as initial RAM for Stack, etc, does not 3656 require any physical RAM backing up the cache. The cleverness 3657 is that the cache is being used as a temporary supply of 3658 necessary storage before the SDRAM controller is setup. It's 3659 beyond the scope of this list to explain the details, but you 3660 can see how this works by studying the cache architecture and 3661 operation in the architecture and processor-specific manuals. 3662 3663 OCM is On Chip Memory, which I believe the 405GP has 4K. It 3664 is another option for the system designer to use as an 3665 initial stack/RAM area prior to SDRAM being available. Either 3666 option should work for you. Using CS 4 should be fine if your 3667 board designers haven't used it for something that would 3668 cause you grief during the initial boot! It is frequently not 3669 used. 3670 3671 CFG_INIT_RAM_ADDR should be somewhere that won't interfere 3672 with your processor/board/system design. The default value 3673 you will find in any recent u-boot distribution in 3674 walnut.h should work for you. I'd set it to a value larger 3675 than your SDRAM module. If you have a 64MB SDRAM module, set 3676 it above 400_0000. Just make sure your board has no resources 3677 that are supposed to respond to that address! That code in 3678 start.S has been around a while and should work as is when 3679 you get the config right. 3680 3681 -Chris Hallinan 3682 DS4.COM, Inc. 3683 3684It is essential to remember this, since it has some impact on the C 3685code for the initialization procedures: 3686 3687* Initialized global data (data segment) is read-only. Do not attempt 3688 to write it. 3689 3690* Do not use any uninitialized global data (or implicitely initialized 3691 as zero data - BSS segment) at all - this is undefined, initiali- 3692 zation is performed later (when relocating to RAM). 3693 3694* Stack space is very limited. Avoid big data buffers or things like 3695 that. 3696 3697Having only the stack as writable memory limits means we cannot use 3698normal global data to share information beween the code. But it 3699turned out that the implementation of U-Boot can be greatly 3700simplified by making a global data structure (gd_t) available to all 3701functions. We could pass a pointer to this data as argument to _all_ 3702functions, but this would bloat the code. Instead we use a feature of 3703the GCC compiler (Global Register Variables) to share the data: we 3704place a pointer (gd) to the global data into a register which we 3705reserve for this purpose. 3706 3707When choosing a register for such a purpose we are restricted by the 3708relevant (E)ABI specifications for the current architecture, and by 3709GCC's implementation. 3710 3711For PowerPC, the following registers have specific use: 3712 R1: stack pointer 3713 R2: reserved for system use 3714 R3-R4: parameter passing and return values 3715 R5-R10: parameter passing 3716 R13: small data area pointer 3717 R30: GOT pointer 3718 R31: frame pointer 3719 3720 (U-Boot also uses R14 as internal GOT pointer.) 3721 3722 ==> U-Boot will use R2 to hold a pointer to the global data 3723 3724 Note: on PPC, we could use a static initializer (since the 3725 address of the global data structure is known at compile time), 3726 but it turned out that reserving a register results in somewhat 3727 smaller code - although the code savings are not that big (on 3728 average for all boards 752 bytes for the whole U-Boot image, 3729 624 text + 127 data). 3730 3731On Blackfin, the normal C ABI (except for P5) is followed as documented here: 3732 http://docs.blackfin.uclinux.org/doku.php?id=application_binary_interface 3733 3734 ==> U-Boot will use P5 to hold a pointer to the global data 3735 3736On ARM, the following registers are used: 3737 3738 R0: function argument word/integer result 3739 R1-R3: function argument word 3740 R9: GOT pointer 3741 R10: stack limit (used only if stack checking if enabled) 3742 R11: argument (frame) pointer 3743 R12: temporary workspace 3744 R13: stack pointer 3745 R14: link register 3746 R15: program counter 3747 3748 ==> U-Boot will use R8 to hold a pointer to the global data 3749 3750NOTE: DECLARE_GLOBAL_DATA_PTR must be used with file-global scope, 3751or current versions of GCC may "optimize" the code too much. 3752 3753Memory Management: 3754------------------ 3755 3756U-Boot runs in system state and uses physical addresses, i.e. the 3757MMU is not used either for address mapping nor for memory protection. 3758 3759The available memory is mapped to fixed addresses using the memory 3760controller. In this process, a contiguous block is formed for each 3761memory type (Flash, SDRAM, SRAM), even when it consists of several 3762physical memory banks. 3763 3764U-Boot is installed in the first 128 kB of the first Flash bank (on 3765TQM8xxL modules this is the range 0x40000000 ... 0x4001FFFF). After 3766booting and sizing and initializing DRAM, the code relocates itself 3767to the upper end of DRAM. Immediately below the U-Boot code some 3768memory is reserved for use by malloc() [see CFG_MALLOC_LEN 3769configuration setting]. Below that, a structure with global Board 3770Info data is placed, followed by the stack (growing downward). 3771 3772Additionally, some exception handler code is copied to the low 8 kB 3773of DRAM (0x00000000 ... 0x00001FFF). 3774 3775So a typical memory configuration with 16 MB of DRAM could look like 3776this: 3777 3778 0x0000 0000 Exception Vector code 3779 : 3780 0x0000 1FFF 3781 0x0000 2000 Free for Application Use 3782 : 3783 : 3784 3785 : 3786 : 3787 0x00FB FF20 Monitor Stack (Growing downward) 3788 0x00FB FFAC Board Info Data and permanent copy of global data 3789 0x00FC 0000 Malloc Arena 3790 : 3791 0x00FD FFFF 3792 0x00FE 0000 RAM Copy of Monitor Code 3793 ... eventually: LCD or video framebuffer 3794 ... eventually: pRAM (Protected RAM - unchanged by reset) 3795 0x00FF FFFF [End of RAM] 3796 3797 3798System Initialization: 3799---------------------- 3800 3801In the reset configuration, U-Boot starts at the reset entry point 3802(on most PowerPC systems at address 0x00000100). Because of the reset 3803configuration for CS0# this is a mirror of the onboard Flash memory. 3804To be able to re-map memory U-Boot then jumps to its link address. 3805To be able to implement the initialization code in C, a (small!) 3806initial stack is set up in the internal Dual Ported RAM (in case CPUs 3807which provide such a feature like MPC8xx or MPC8260), or in a locked 3808part of the data cache. After that, U-Boot initializes the CPU core, 3809the caches and the SIU. 3810 3811Next, all (potentially) available memory banks are mapped using a 3812preliminary mapping. For example, we put them on 512 MB boundaries 3813(multiples of 0x20000000: SDRAM on 0x00000000 and 0x20000000, Flash 3814on 0x40000000 and 0x60000000, SRAM on 0x80000000). Then UPM A is 3815programmed for SDRAM access. Using the temporary configuration, a 3816simple memory test is run that determines the size of the SDRAM 3817banks. 3818 3819When there is more than one SDRAM bank, and the banks are of 3820different size, the largest is mapped first. For equal size, the first 3821bank (CS2#) is mapped first. The first mapping is always for address 38220x00000000, with any additional banks following immediately to create 3823contiguous memory starting from 0. 3824 3825Then, the monitor installs itself at the upper end of the SDRAM area 3826and allocates memory for use by malloc() and for the global Board 3827Info data; also, the exception vector code is copied to the low RAM 3828pages, and the final stack is set up. 3829 3830Only after this relocation will you have a "normal" C environment; 3831until that you are restricted in several ways, mostly because you are 3832running from ROM, and because the code will have to be relocated to a 3833new address in RAM. 3834 3835 3836U-Boot Porting Guide: 3837---------------------- 3838 3839[Based on messages by Jerry Van Baren in the U-Boot-Users mailing 3840list, October 2002] 3841 3842 3843int main (int argc, char *argv[]) 3844{ 3845 sighandler_t no_more_time; 3846 3847 signal (SIGALRM, no_more_time); 3848 alarm (PROJECT_DEADLINE - toSec (3 * WEEK)); 3849 3850 if (available_money > available_manpower) { 3851 pay consultant to port U-Boot; 3852 return 0; 3853 } 3854 3855 Download latest U-Boot source; 3856 3857 Subscribe to u-boot-users mailing list; 3858 3859 if (clueless) { 3860 email ("Hi, I am new to U-Boot, how do I get started?"); 3861 } 3862 3863 while (learning) { 3864 Read the README file in the top level directory; 3865 Read http://www.denx.de/twiki/bin/view/DULG/Manual ; 3866 Read the source, Luke; 3867 } 3868 3869 if (available_money > toLocalCurrency ($2500)) { 3870 Buy a BDI2000; 3871 } else { 3872 Add a lot of aggravation and time; 3873 } 3874 3875 Create your own board support subdirectory; 3876 3877 Create your own board config file; 3878 3879 while (!running) { 3880 do { 3881 Add / modify source code; 3882 } until (compiles); 3883 Debug; 3884 if (clueless) 3885 email ("Hi, I am having problems..."); 3886 } 3887 Send patch file to Wolfgang; 3888 3889 return 0; 3890} 3891 3892void no_more_time (int sig) 3893{ 3894 hire_a_guru(); 3895} 3896 3897 3898Coding Standards: 3899----------------- 3900 3901All contributions to U-Boot should conform to the Linux kernel 3902coding style; see the file "Documentation/CodingStyle" and the script 3903"scripts/Lindent" in your Linux kernel source directory. In sources 3904originating from U-Boot a style corresponding to "Lindent -pcs" (adding 3905spaces before parameters to function calls) is actually used. 3906 3907Source files originating from a different project (for example the 3908MTD subsystem) are generally exempt from these guidelines and are not 3909reformated to ease subsequent migration to newer versions of those 3910sources. 3911 3912Please note that U-Boot is implemented in C (and to some small parts in 3913Assembler); no C++ is used, so please do not use C++ style comments (//) 3914in your code. 3915 3916Please also stick to the following formatting rules: 3917- remove any trailing white space 3918- use TAB characters for indentation, not spaces 3919- make sure NOT to use DOS '\r\n' line feeds 3920- do not add more than 2 empty lines to source files 3921- do not add trailing empty lines to source files 3922 3923Submissions which do not conform to the standards may be returned 3924with a request to reformat the changes. 3925 3926 3927Submitting Patches: 3928------------------- 3929 3930Since the number of patches for U-Boot is growing, we need to 3931establish some rules. Submissions which do not conform to these rules 3932may be rejected, even when they contain important and valuable stuff. 3933 3934Patches shall be sent to the u-boot-users mailing list. 3935 3936Please see http://www.denx.de/wiki/U-Boot/Patches for details. 3937 3938When you send a patch, please include the following information with 3939it: 3940 3941* For bug fixes: a description of the bug and how your patch fixes 3942 this bug. Please try to include a way of demonstrating that the 3943 patch actually fixes something. 3944 3945* For new features: a description of the feature and your 3946 implementation. 3947 3948* A CHANGELOG entry as plaintext (separate from the patch) 3949 3950* For major contributions, your entry to the CREDITS file 3951 3952* When you add support for a new board, don't forget to add this 3953 board to the MAKEALL script, too. 3954 3955* If your patch adds new configuration options, don't forget to 3956 document these in the README file. 3957 3958* The patch itself. If you are using git (which is *strongly* 3959 recommended) you can easily generate the patch using the 3960 "git-format-patch". If you then use "git-send-email" to send it to 3961 the U-Boot mailing list, you will avoid most of the common problems 3962 with some other mail clients. 3963 3964 If you cannot use git, use "diff -purN OLD NEW". If your version of 3965 diff does not support these options, then get the latest version of 3966 GNU diff. 3967 3968 The current directory when running this command shall be the parent 3969 directory of the U-Boot source tree (i. e. please make sure that 3970 your patch includes sufficient directory information for the 3971 affected files). 3972 3973 We prefer patches as plain text. MIME attachments are discouraged, 3974 and compressed attachments must not be used. 3975 3976* If one logical set of modifications affects or creates several 3977 files, all these changes shall be submitted in a SINGLE patch file. 3978 3979* Changesets that contain different, unrelated modifications shall be 3980 submitted as SEPARATE patches, one patch per changeset. 3981 3982 3983Notes: 3984 3985* Before sending the patch, run the MAKEALL script on your patched 3986 source tree and make sure that no errors or warnings are reported 3987 for any of the boards. 3988 3989* Keep your modifications to the necessary minimum: A patch 3990 containing several unrelated changes or arbitrary reformats will be 3991 returned with a request to re-formatting / split it. 3992 3993* If you modify existing code, make sure that your new code does not 3994 add to the memory footprint of the code ;-) Small is beautiful! 3995 When adding new features, these should compile conditionally only 3996 (using #ifdef), and the resulting code with the new feature 3997 disabled must not need more memory than the old code without your 3998 modification. 3999 4000* Remember that there is a size limit of 40 kB per message on the 4001 u-boot-users mailing list. Bigger patches will be moderated. If 4002 they are reasonable and not bigger than 100 kB, they will be 4003 acknowledged. Even bigger patches should be avoided. 4004