1# 2# (C) Copyright 2000 - 2005 3# Wolfgang Denk, DENX Software Engineering, wd@denx.de. 4# 5# See file CREDITS for list of people who contributed to this 6# project. 7# 8# This program is free software; you can redistribute it and/or 9# modify it under the terms of the GNU General Public License as 10# published by the Free Software Foundation; either version 2 of 11# the License, or (at your option) any later version. 12# 13# This program is distributed in the hope that it will be useful, 14# but WITHOUT ANY WARRANTY; without even the implied warranty of 15# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 16# GNU General Public License for more details. 17# 18# You should have received a copy of the GNU General Public License 19# along with this program; if not, write to the Free Software 20# Foundation, Inc., 59 Temple Place, Suite 330, Boston, 21# MA 02111-1307 USA 22# 23 24Summary: 25======== 26 27This directory contains the source code for U-Boot, a boot loader for 28Embedded boards based on PowerPC, ARM, MIPS and several other 29processors, which can be installed in a boot ROM and used to 30initialize and test the hardware or to download and run application 31code. 32 33The development of U-Boot is closely related to Linux: some parts of 34the source code originate in the Linux source tree, we have some 35header files in common, and special provision has been made to 36support booting of Linux images. 37 38Some attention has been paid to make this software easily 39configurable and extendable. For instance, all monitor commands are 40implemented with the same call interface, so that it's very easy to 41add new commands. Also, instead of permanently adding rarely used 42code (for instance hardware test utilities) to the monitor, you can 43load and run it dynamically. 44 45 46Status: 47======= 48 49In general, all boards for which a configuration option exists in the 50Makefile have been tested to some extent and can be considered 51"working". In fact, many of them are used in production systems. 52 53In case of problems see the CHANGELOG and CREDITS files to find out 54who contributed the specific port. 55 56 57Where to get help: 58================== 59 60In case you have questions about, problems with or contributions for 61U-Boot you should send a message to the U-Boot mailing list at 62<u-boot-users@lists.sourceforge.net>. There is also an archive of 63previous traffic on the mailing list - please search the archive 64before asking FAQ's. Please see 65http://lists.sourceforge.net/lists/listinfo/u-boot-users/ 66 67 68Where we come from: 69=================== 70 71- start from 8xxrom sources 72- create PPCBoot project (http://sourceforge.net/projects/ppcboot) 73- clean up code 74- make it easier to add custom boards 75- make it possible to add other [PowerPC] CPUs 76- extend functions, especially: 77 * Provide extended interface to Linux boot loader 78 * S-Record download 79 * network boot 80 * PCMCIA / CompactFLash / ATA disk / SCSI ... boot 81- create ARMBoot project (http://sourceforge.net/projects/armboot) 82- add other CPU families (starting with ARM) 83- create U-Boot project (http://sourceforge.net/projects/u-boot) 84 85 86Names and Spelling: 87=================== 88 89The "official" name of this project is "Das U-Boot". The spelling 90"U-Boot" shall be used in all written text (documentation, comments 91in source files etc.). Example: 92 93 This is the README file for the U-Boot project. 94 95File names etc. shall be based on the string "u-boot". Examples: 96 97 include/asm-ppc/u-boot.h 98 99 #include <asm/u-boot.h> 100 101Variable names, preprocessor constants etc. shall be either based on 102the string "u_boot" or on "U_BOOT". Example: 103 104 U_BOOT_VERSION u_boot_logo 105 IH_OS_U_BOOT u_boot_hush_start 106 107 108Versioning: 109=========== 110 111U-Boot uses a 3 level version number containing a version, a 112sub-version, and a patchlevel: "U-Boot-2.34.5" means version "2", 113sub-version "34", and patchlevel "4". 114 115The patchlevel is used to indicate certain stages of development 116between released versions, i. e. officially released versions of 117U-Boot will always have a patchlevel of "0". 118 119 120Directory Hierarchy: 121==================== 122 123- board Board dependent files 124- common Misc architecture independent functions 125- cpu CPU specific files 126 - 74xx_7xx Files specific to Freescale MPC74xx and 7xx CPUs 127 - arm720t Files specific to ARM 720 CPUs 128 - arm920t Files specific to ARM 920 CPUs 129 - at91rm9200 Files specific to Atmel AT91RM9200 CPU 130 - imx Files specific to Freescale MC9328 i.MX CPUs 131 - s3c24x0 Files specific to Samsung S3C24X0 CPUs 132 - arm925t Files specific to ARM 925 CPUs 133 - arm926ejs Files specific to ARM 926 CPUs 134 - arm1136 Files specific to ARM 1136 CPUs 135 - at32ap Files specific to Atmel AVR32 AP CPUs 136 - i386 Files specific to i386 CPUs 137 - ixp Files specific to Intel XScale IXP CPUs 138 - mcf52x2 Files specific to Freescale ColdFire MCF52x2 CPUs 139 - mcf5227x Files specific to Freescale ColdFire MCF5227x CPUs 140 - mcf532x Files specific to Freescale ColdFire MCF5329 CPUs 141 - mcf5445x Files specific to Freescale ColdFire MCF5445x CPUs 142 - mcf547x_8x Files specific to Freescale ColdFire MCF547x_8x CPUs 143 - mips Files specific to MIPS CPUs 144 - mpc5xx Files specific to Freescale MPC5xx CPUs 145 - mpc5xxx Files specific to Freescale MPC5xxx CPUs 146 - mpc8xx Files specific to Freescale MPC8xx CPUs 147 - mpc8220 Files specific to Freescale MPC8220 CPUs 148 - mpc824x Files specific to Freescale MPC824x CPUs 149 - mpc8260 Files specific to Freescale MPC8260 CPUs 150 - mpc85xx Files specific to Freescale MPC85xx CPUs 151 - nios Files specific to Altera NIOS CPUs 152 - nios2 Files specific to Altera Nios-II CPUs 153 - ppc4xx Files specific to AMCC PowerPC 4xx CPUs 154 - pxa Files specific to Intel XScale PXA CPUs 155 - s3c44b0 Files specific to Samsung S3C44B0 CPUs 156 - sa1100 Files specific to Intel StrongARM SA1100 CPUs 157- disk Code for disk drive partition handling 158- doc Documentation (don't expect too much) 159- drivers Commonly used device drivers 160- dtt Digital Thermometer and Thermostat drivers 161- examples Example code for standalone applications, etc. 162- include Header Files 163- lib_arm Files generic to ARM architecture 164- lib_avr32 Files generic to AVR32 architecture 165- lib_generic Files generic to all architectures 166- lib_i386 Files generic to i386 architecture 167- lib_m68k Files generic to m68k architecture 168- lib_mips Files generic to MIPS architecture 169- lib_nios Files generic to NIOS architecture 170- lib_ppc Files generic to PowerPC architecture 171- libfdt Library files to support flattened device trees 172- net Networking code 173- post Power On Self Test 174- rtc Real Time Clock drivers 175- tools Tools to build S-Record or U-Boot images, etc. 176 177Software Configuration: 178======================= 179 180Configuration is usually done using C preprocessor defines; the 181rationale behind that is to avoid dead code whenever possible. 182 183There are two classes of configuration variables: 184 185* Configuration _OPTIONS_: 186 These are selectable by the user and have names beginning with 187 "CONFIG_". 188 189* Configuration _SETTINGS_: 190 These depend on the hardware etc. and should not be meddled with if 191 you don't know what you're doing; they have names beginning with 192 "CFG_". 193 194Later we will add a configuration tool - probably similar to or even 195identical to what's used for the Linux kernel. Right now, we have to 196do the configuration by hand, which means creating some symbolic 197links and editing some configuration files. We use the TQM8xxL boards 198as an example here. 199 200 201Selection of Processor Architecture and Board Type: 202--------------------------------------------------- 203 204For all supported boards there are ready-to-use default 205configurations available; just type "make <board_name>_config". 206 207Example: For a TQM823L module type: 208 209 cd u-boot 210 make TQM823L_config 211 212For the Cogent platform, you need to specify the cpu type as well; 213e.g. "make cogent_mpc8xx_config". And also configure the cogent 214directory according to the instructions in cogent/README. 215 216 217Configuration Options: 218---------------------- 219 220Configuration depends on the combination of board and CPU type; all 221such information is kept in a configuration file 222"include/configs/<board_name>.h". 223 224Example: For a TQM823L module, all configuration settings are in 225"include/configs/TQM823L.h". 226 227 228Many of the options are named exactly as the corresponding Linux 229kernel configuration options. The intention is to make it easier to 230build a config tool - later. 231 232 233The following options need to be configured: 234 235- CPU Type: Define exactly one, e.g. CONFIG_MPC85XX. 236 237- Board Type: Define exactly one, e.g. CONFIG_MPC8540ADS. 238 239- CPU Daughterboard Type: (if CONFIG_ATSTK1000 is defined) 240 Define exactly one, e.g. CONFIG_ATSTK1002 241 242- CPU Module Type: (if CONFIG_COGENT is defined) 243 Define exactly one of 244 CONFIG_CMA286_60_OLD 245--- FIXME --- not tested yet: 246 CONFIG_CMA286_60, CONFIG_CMA286_21, CONFIG_CMA286_60P, 247 CONFIG_CMA287_23, CONFIG_CMA287_50 248 249- Motherboard Type: (if CONFIG_COGENT is defined) 250 Define exactly one of 251 CONFIG_CMA101, CONFIG_CMA102 252 253- Motherboard I/O Modules: (if CONFIG_COGENT is defined) 254 Define one or more of 255 CONFIG_CMA302 256 257- Motherboard Options: (if CONFIG_CMA101 or CONFIG_CMA102 are defined) 258 Define one or more of 259 CONFIG_LCD_HEARTBEAT - update a character position on 260 the lcd display every second with 261 a "rotator" |\-/|\-/ 262 263- Board flavour: (if CONFIG_MPC8260ADS is defined) 264 CONFIG_ADSTYPE 265 Possible values are: 266 CFG_8260ADS - original MPC8260ADS 267 CFG_8266ADS - MPC8266ADS 268 CFG_PQ2FADS - PQ2FADS-ZU or PQ2FADS-VR 269 CFG_8272ADS - MPC8272ADS 270 271- MPC824X Family Member (if CONFIG_MPC824X is defined) 272 Define exactly one of 273 CONFIG_MPC8240, CONFIG_MPC8245 274 275- 8xx CPU Options: (if using an MPC8xx cpu) 276 CONFIG_8xx_GCLK_FREQ - deprecated: CPU clock if 277 get_gclk_freq() cannot work 278 e.g. if there is no 32KHz 279 reference PIT/RTC clock 280 CONFIG_8xx_OSCLK - PLL input clock (either EXTCLK 281 or XTAL/EXTAL) 282 283- 859/866/885 CPU options: (if using a MPC859 or MPC866 or MPC885 CPU): 284 CFG_8xx_CPUCLK_MIN 285 CFG_8xx_CPUCLK_MAX 286 CONFIG_8xx_CPUCLK_DEFAULT 287 See doc/README.MPC866 288 289 CFG_MEASURE_CPUCLK 290 291 Define this to measure the actual CPU clock instead 292 of relying on the correctness of the configured 293 values. Mostly useful for board bringup to make sure 294 the PLL is locked at the intended frequency. Note 295 that this requires a (stable) reference clock (32 kHz 296 RTC clock or CFG_8XX_XIN) 297 298- Intel Monahans options: 299 CFG_MONAHANS_RUN_MODE_OSC_RATIO 300 301 Defines the Monahans run mode to oscillator 302 ratio. Valid values are 8, 16, 24, 31. The core 303 frequency is this value multiplied by 13 MHz. 304 305 CFG_MONAHANS_TURBO_RUN_MODE_RATIO 306 307 Defines the Monahans turbo mode to oscillator 308 ratio. Valid values are 1 (default if undefined) and 309 2. The core frequency as calculated above is multiplied 310 by this value. 311 312- Linux Kernel Interface: 313 CONFIG_CLOCKS_IN_MHZ 314 315 U-Boot stores all clock information in Hz 316 internally. For binary compatibility with older Linux 317 kernels (which expect the clocks passed in the 318 bd_info data to be in MHz) the environment variable 319 "clocks_in_mhz" can be defined so that U-Boot 320 converts clock data to MHZ before passing it to the 321 Linux kernel. 322 When CONFIG_CLOCKS_IN_MHZ is defined, a definition of 323 "clocks_in_mhz=1" is automatically included in the 324 default environment. 325 326 CONFIG_MEMSIZE_IN_BYTES [relevant for MIPS only] 327 328 When transfering memsize parameter to linux, some versions 329 expect it to be in bytes, others in MB. 330 Define CONFIG_MEMSIZE_IN_BYTES to make it in bytes. 331 332 CONFIG_OF_LIBFDT / CONFIG_OF_FLAT_TREE 333 334 New kernel versions are expecting firmware settings to be 335 passed using flattened device trees (based on open firmware 336 concepts). 337 338 CONFIG_OF_LIBFDT 339 * New libfdt-based support 340 * Adds the "fdt" command 341 * The bootm command automatically updates the fdt 342 343 CONFIG_OF_FLAT_TREE 344 * Deprecated, see CONFIG_OF_LIBFDT 345 * Original ft_build.c-based support 346 * Automatically modifies the dft as part of the bootm command 347 * The environment variable "disable_of", when set, 348 disables this functionality. 349 350 OF_CPU - The proper name of the cpus node. 351 OF_SOC - The proper name of the soc node. 352 OF_TBCLK - The timebase frequency. 353 OF_STDOUT_PATH - The path to the console device 354 355 boards with QUICC Engines require OF_QE to set UCC mac addresses 356 357 CONFIG_OF_HAS_BD_T 358 359 * CONFIG_OF_LIBFDT - enables the "fdt bd_t" command 360 * CONFIG_OF_FLAT_TREE - The resulting flat device tree 361 will have a copy of the bd_t. Space should be 362 pre-allocated in the dts for the bd_t. 363 364 CONFIG_OF_HAS_UBOOT_ENV 365 366 * CONFIG_OF_LIBFDT - enables the "fdt env" command 367 * CONFIG_OF_FLAT_TREE - The resulting flat device tree 368 will have a copy of u-boot's environment variables 369 370 CONFIG_OF_BOARD_SETUP 371 372 Board code has addition modification that it wants to make 373 to the flat device tree before handing it off to the kernel 374 375 CONFIG_OF_BOOT_CPU 376 377 This define fills in the correct boot cpu in the boot 378 param header, the default value is zero if undefined. 379 380- Serial Ports: 381 CFG_PL010_SERIAL 382 383 Define this if you want support for Amba PrimeCell PL010 UARTs. 384 385 CFG_PL011_SERIAL 386 387 Define this if you want support for Amba PrimeCell PL011 UARTs. 388 389 CONFIG_PL011_CLOCK 390 391 If you have Amba PrimeCell PL011 UARTs, set this variable to 392 the clock speed of the UARTs. 393 394 CONFIG_PL01x_PORTS 395 396 If you have Amba PrimeCell PL010 or PL011 UARTs on your board, 397 define this to a list of base addresses for each (supported) 398 port. See e.g. include/configs/versatile.h 399 400 401- Console Interface: 402 Depending on board, define exactly one serial port 403 (like CONFIG_8xx_CONS_SMC1, CONFIG_8xx_CONS_SMC2, 404 CONFIG_8xx_CONS_SCC1, ...), or switch off the serial 405 console by defining CONFIG_8xx_CONS_NONE 406 407 Note: if CONFIG_8xx_CONS_NONE is defined, the serial 408 port routines must be defined elsewhere 409 (i.e. serial_init(), serial_getc(), ...) 410 411 CONFIG_CFB_CONSOLE 412 Enables console device for a color framebuffer. Needs following 413 defines (cf. smiLynxEM, i8042, board/eltec/bab7xx) 414 VIDEO_FB_LITTLE_ENDIAN graphic memory organisation 415 (default big endian) 416 VIDEO_HW_RECTFILL graphic chip supports 417 rectangle fill 418 (cf. smiLynxEM) 419 VIDEO_HW_BITBLT graphic chip supports 420 bit-blit (cf. smiLynxEM) 421 VIDEO_VISIBLE_COLS visible pixel columns 422 (cols=pitch) 423 VIDEO_VISIBLE_ROWS visible pixel rows 424 VIDEO_PIXEL_SIZE bytes per pixel 425 VIDEO_DATA_FORMAT graphic data format 426 (0-5, cf. cfb_console.c) 427 VIDEO_FB_ADRS framebuffer address 428 VIDEO_KBD_INIT_FCT keyboard int fct 429 (i.e. i8042_kbd_init()) 430 VIDEO_TSTC_FCT test char fct 431 (i.e. i8042_tstc) 432 VIDEO_GETC_FCT get char fct 433 (i.e. i8042_getc) 434 CONFIG_CONSOLE_CURSOR cursor drawing on/off 435 (requires blink timer 436 cf. i8042.c) 437 CFG_CONSOLE_BLINK_COUNT blink interval (cf. i8042.c) 438 CONFIG_CONSOLE_TIME display time/date info in 439 upper right corner 440 (requires CONFIG_CMD_DATE) 441 CONFIG_VIDEO_LOGO display Linux logo in 442 upper left corner 443 CONFIG_VIDEO_BMP_LOGO use bmp_logo.h instead of 444 linux_logo.h for logo. 445 Requires CONFIG_VIDEO_LOGO 446 CONFIG_CONSOLE_EXTRA_INFO 447 addional board info beside 448 the logo 449 450 When CONFIG_CFB_CONSOLE is defined, video console is 451 default i/o. Serial console can be forced with 452 environment 'console=serial'. 453 454 When CONFIG_SILENT_CONSOLE is defined, all console 455 messages (by U-Boot and Linux!) can be silenced with 456 the "silent" environment variable. See 457 doc/README.silent for more information. 458 459- Console Baudrate: 460 CONFIG_BAUDRATE - in bps 461 Select one of the baudrates listed in 462 CFG_BAUDRATE_TABLE, see below. 463 CFG_BRGCLK_PRESCALE, baudrate prescale 464 465- Interrupt driven serial port input: 466 CONFIG_SERIAL_SOFTWARE_FIFO 467 468 PPC405GP only. 469 Use an interrupt handler for receiving data on the 470 serial port. It also enables using hardware handshake 471 (RTS/CTS) and UART's built-in FIFO. Set the number of 472 bytes the interrupt driven input buffer should have. 473 474 Leave undefined to disable this feature, including 475 disable the buffer and hardware handshake. 476 477- Console UART Number: 478 CONFIG_UART1_CONSOLE 479 480 AMCC PPC4xx only. 481 If defined internal UART1 (and not UART0) is used 482 as default U-Boot console. 483 484- Boot Delay: CONFIG_BOOTDELAY - in seconds 485 Delay before automatically booting the default image; 486 set to -1 to disable autoboot. 487 488 See doc/README.autoboot for these options that 489 work with CONFIG_BOOTDELAY. None are required. 490 CONFIG_BOOT_RETRY_TIME 491 CONFIG_BOOT_RETRY_MIN 492 CONFIG_AUTOBOOT_KEYED 493 CONFIG_AUTOBOOT_PROMPT 494 CONFIG_AUTOBOOT_DELAY_STR 495 CONFIG_AUTOBOOT_STOP_STR 496 CONFIG_AUTOBOOT_DELAY_STR2 497 CONFIG_AUTOBOOT_STOP_STR2 498 CONFIG_ZERO_BOOTDELAY_CHECK 499 CONFIG_RESET_TO_RETRY 500 501- Autoboot Command: 502 CONFIG_BOOTCOMMAND 503 Only needed when CONFIG_BOOTDELAY is enabled; 504 define a command string that is automatically executed 505 when no character is read on the console interface 506 within "Boot Delay" after reset. 507 508 CONFIG_BOOTARGS 509 This can be used to pass arguments to the bootm 510 command. The value of CONFIG_BOOTARGS goes into the 511 environment value "bootargs". 512 513 CONFIG_RAMBOOT and CONFIG_NFSBOOT 514 The value of these goes into the environment as 515 "ramboot" and "nfsboot" respectively, and can be used 516 as a convenience, when switching between booting from 517 ram and nfs. 518 519- Pre-Boot Commands: 520 CONFIG_PREBOOT 521 522 When this option is #defined, the existence of the 523 environment variable "preboot" will be checked 524 immediately before starting the CONFIG_BOOTDELAY 525 countdown and/or running the auto-boot command resp. 526 entering interactive mode. 527 528 This feature is especially useful when "preboot" is 529 automatically generated or modified. For an example 530 see the LWMON board specific code: here "preboot" is 531 modified when the user holds down a certain 532 combination of keys on the (special) keyboard when 533 booting the systems 534 535- Serial Download Echo Mode: 536 CONFIG_LOADS_ECHO 537 If defined to 1, all characters received during a 538 serial download (using the "loads" command) are 539 echoed back. This might be needed by some terminal 540 emulations (like "cu"), but may as well just take 541 time on others. This setting #define's the initial 542 value of the "loads_echo" environment variable. 543 544- Kgdb Serial Baudrate: (if CONFIG_CMD_KGDB is defined) 545 CONFIG_KGDB_BAUDRATE 546 Select one of the baudrates listed in 547 CFG_BAUDRATE_TABLE, see below. 548 549- Monitor Functions: 550 Monitor commands can be included or excluded 551 from the build by using the #include files 552 "config_cmd_all.h" and #undef'ing unwanted 553 commands, or using "config_cmd_default.h" 554 and augmenting with additional #define's 555 for wanted commands. 556 557 The default command configuration includes all commands 558 except those marked below with a "*". 559 560 CONFIG_CMD_ASKENV * ask for env variable 561 CONFIG_CMD_AUTOSCRIPT Autoscript Support 562 CONFIG_CMD_BDI bdinfo 563 CONFIG_CMD_BEDBUG * Include BedBug Debugger 564 CONFIG_CMD_BMP * BMP support 565 CONFIG_CMD_BSP * Board specific commands 566 CONFIG_CMD_BOOTD bootd 567 CONFIG_CMD_CACHE * icache, dcache 568 CONFIG_CMD_CONSOLE coninfo 569 CONFIG_CMD_DATE * support for RTC, date/time... 570 CONFIG_CMD_DHCP * DHCP support 571 CONFIG_CMD_DIAG * Diagnostics 572 CONFIG_CMD_DOC * Disk-On-Chip Support 573 CONFIG_CMD_DTT * Digital Therm and Thermostat 574 CONFIG_CMD_ECHO echo arguments 575 CONFIG_CMD_EEPROM * EEPROM read/write support 576 CONFIG_CMD_ELF * bootelf, bootvx 577 CONFIG_CMD_ENV saveenv 578 CONFIG_CMD_FDC * Floppy Disk Support 579 CONFIG_CMD_FAT * FAT partition support 580 CONFIG_CMD_FDOS * Dos diskette Support 581 CONFIG_CMD_FLASH flinfo, erase, protect 582 CONFIG_CMD_FPGA FPGA device initialization support 583 CONFIG_CMD_HWFLOW * RTS/CTS hw flow control 584 CONFIG_CMD_I2C * I2C serial bus support 585 CONFIG_CMD_IDE * IDE harddisk support 586 CONFIG_CMD_IMI iminfo 587 CONFIG_CMD_IMLS List all found images 588 CONFIG_CMD_IMMAP * IMMR dump support 589 CONFIG_CMD_IRQ * irqinfo 590 CONFIG_CMD_ITEST Integer/string test of 2 values 591 CONFIG_CMD_JFFS2 * JFFS2 Support 592 CONFIG_CMD_KGDB * kgdb 593 CONFIG_CMD_LOADB loadb 594 CONFIG_CMD_LOADS loads 595 CONFIG_CMD_MEMORY md, mm, nm, mw, cp, cmp, crc, base, 596 loop, loopw, mtest 597 CONFIG_CMD_MISC Misc functions like sleep etc 598 CONFIG_CMD_MMC * MMC memory mapped support 599 CONFIG_CMD_MII * MII utility commands 600 CONFIG_CMD_NAND * NAND support 601 CONFIG_CMD_NET bootp, tftpboot, rarpboot 602 CONFIG_CMD_PCI * pciinfo 603 CONFIG_CMD_PCMCIA * PCMCIA support 604 CONFIG_CMD_PING * send ICMP ECHO_REQUEST to network 605 host 606 CONFIG_CMD_PORTIO * Port I/O 607 CONFIG_CMD_REGINFO * Register dump 608 CONFIG_CMD_RUN run command in env variable 609 CONFIG_CMD_SAVES * save S record dump 610 CONFIG_CMD_SCSI * SCSI Support 611 CONFIG_CMD_SDRAM * print SDRAM configuration information 612 (requires CONFIG_CMD_I2C) 613 CONFIG_CMD_SETGETDCR Support for DCR Register access 614 (4xx only) 615 CONFIG_CMD_SPI * SPI serial bus support 616 CONFIG_CMD_USB * USB support 617 CONFIG_CMD_VFD * VFD support (TRAB) 618 CONFIG_CMD_BSP * Board SPecific functions 619 CONFIG_CMD_CDP * Cisco Discover Protocol support 620 CONFIG_CMD_FSL * Microblaze FSL support 621 622 623 EXAMPLE: If you want all functions except of network 624 support you can write: 625 626 #include "config_cmd_all.h" 627 #undef CONFIG_CMD_NET 628 629 Other Commands: 630 fdt (flattened device tree) command: CONFIG_OF_LIBFDT 631 632 Note: Don't enable the "icache" and "dcache" commands 633 (configuration option CONFIG_CMD_CACHE) unless you know 634 what you (and your U-Boot users) are doing. Data 635 cache cannot be enabled on systems like the 8xx or 636 8260 (where accesses to the IMMR region must be 637 uncached), and it cannot be disabled on all other 638 systems where we (mis-) use the data cache to hold an 639 initial stack and some data. 640 641 642 XXX - this list needs to get updated! 643 644- Watchdog: 645 CONFIG_WATCHDOG 646 If this variable is defined, it enables watchdog 647 support. There must be support in the platform specific 648 code for a watchdog. For the 8xx and 8260 CPUs, the 649 SIU Watchdog feature is enabled in the SYPCR 650 register. 651 652- U-Boot Version: 653 CONFIG_VERSION_VARIABLE 654 If this variable is defined, an environment variable 655 named "ver" is created by U-Boot showing the U-Boot 656 version as printed by the "version" command. 657 This variable is readonly. 658 659- Real-Time Clock: 660 661 When CONFIG_CMD_DATE is selected, the type of the RTC 662 has to be selected, too. Define exactly one of the 663 following options: 664 665 CONFIG_RTC_MPC8xx - use internal RTC of MPC8xx 666 CONFIG_RTC_PCF8563 - use Philips PCF8563 RTC 667 CONFIG_RTC_MC146818 - use MC146818 RTC 668 CONFIG_RTC_DS1307 - use Maxim, Inc. DS1307 RTC 669 CONFIG_RTC_DS1337 - use Maxim, Inc. DS1337 RTC 670 CONFIG_RTC_DS1338 - use Maxim, Inc. DS1338 RTC 671 CONFIG_RTC_DS164x - use Dallas DS164x RTC 672 CONFIG_RTC_MAX6900 - use Maxim, Inc. MAX6900 RTC 673 674 Note that if the RTC uses I2C, then the I2C interface 675 must also be configured. See I2C Support, below. 676 677- Timestamp Support: 678 679 When CONFIG_TIMESTAMP is selected, the timestamp 680 (date and time) of an image is printed by image 681 commands like bootm or iminfo. This option is 682 automatically enabled when you select CONFIG_CMD_DATE . 683 684- Partition Support: 685 CONFIG_MAC_PARTITION and/or CONFIG_DOS_PARTITION 686 and/or CONFIG_ISO_PARTITION 687 688 If IDE or SCSI support is enabled (CONFIG_CMD_IDE or 689 CONFIG_CMD_SCSI) you must configure support for at least 690 one partition type as well. 691 692- IDE Reset method: 693 CONFIG_IDE_RESET_ROUTINE - this is defined in several 694 board configurations files but used nowhere! 695 696 CONFIG_IDE_RESET - is this is defined, IDE Reset will 697 be performed by calling the function 698 ide_set_reset(int reset) 699 which has to be defined in a board specific file 700 701- ATAPI Support: 702 CONFIG_ATAPI 703 704 Set this to enable ATAPI support. 705 706- LBA48 Support 707 CONFIG_LBA48 708 709 Set this to enable support for disks larger than 137GB 710 Also look at CFG_64BIT_LBA ,CFG_64BIT_VSPRINTF and CFG_64BIT_STRTOUL 711 Whithout these , LBA48 support uses 32bit variables and will 'only' 712 support disks up to 2.1TB. 713 714 CFG_64BIT_LBA: 715 When enabled, makes the IDE subsystem use 64bit sector addresses. 716 Default is 32bit. 717 718- SCSI Support: 719 At the moment only there is only support for the 720 SYM53C8XX SCSI controller; define 721 CONFIG_SCSI_SYM53C8XX to enable it. 722 723 CFG_SCSI_MAX_LUN [8], CFG_SCSI_MAX_SCSI_ID [7] and 724 CFG_SCSI_MAX_DEVICE [CFG_SCSI_MAX_SCSI_ID * 725 CFG_SCSI_MAX_LUN] can be adjusted to define the 726 maximum numbers of LUNs, SCSI ID's and target 727 devices. 728 CFG_SCSI_SYM53C8XX_CCF to fix clock timing (80Mhz) 729 730- NETWORK Support (PCI): 731 CONFIG_E1000 732 Support for Intel 8254x gigabit chips. 733 734 CONFIG_EEPRO100 735 Support for Intel 82557/82559/82559ER chips. 736 Optional CONFIG_EEPRO100_SROM_WRITE enables eeprom 737 write routine for first time initialisation. 738 739 CONFIG_TULIP 740 Support for Digital 2114x chips. 741 Optional CONFIG_TULIP_SELECT_MEDIA for board specific 742 modem chip initialisation (KS8761/QS6611). 743 744 CONFIG_NATSEMI 745 Support for National dp83815 chips. 746 747 CONFIG_NS8382X 748 Support for National dp8382[01] gigabit chips. 749 750- NETWORK Support (other): 751 752 CONFIG_DRIVER_LAN91C96 753 Support for SMSC's LAN91C96 chips. 754 755 CONFIG_LAN91C96_BASE 756 Define this to hold the physical address 757 of the LAN91C96's I/O space 758 759 CONFIG_LAN91C96_USE_32_BIT 760 Define this to enable 32 bit addressing 761 762 CONFIG_DRIVER_SMC91111 763 Support for SMSC's LAN91C111 chip 764 765 CONFIG_SMC91111_BASE 766 Define this to hold the physical address 767 of the device (I/O space) 768 769 CONFIG_SMC_USE_32_BIT 770 Define this if data bus is 32 bits 771 772 CONFIG_SMC_USE_IOFUNCS 773 Define this to use i/o functions instead of macros 774 (some hardware wont work with macros) 775 776- USB Support: 777 At the moment only the UHCI host controller is 778 supported (PIP405, MIP405, MPC5200); define 779 CONFIG_USB_UHCI to enable it. 780 define CONFIG_USB_KEYBOARD to enable the USB Keyboard 781 and define CONFIG_USB_STORAGE to enable the USB 782 storage devices. 783 Note: 784 Supported are USB Keyboards and USB Floppy drives 785 (TEAC FD-05PUB). 786 MPC5200 USB requires additional defines: 787 CONFIG_USB_CLOCK 788 for 528 MHz Clock: 0x0001bbbb 789 CONFIG_USB_CONFIG 790 for differential drivers: 0x00001000 791 for single ended drivers: 0x00005000 792 CFG_USB_EVENT_POLL 793 May be defined to allow interrupt polling 794 instead of using asynchronous interrupts 795 796- USB Device: 797 Define the below if you wish to use the USB console. 798 Once firmware is rebuilt from a serial console issue the 799 command "setenv stdin usbtty; setenv stdout usbtty" and 800 attach your usb cable. The Unix command "dmesg" should print 801 it has found a new device. The environment variable usbtty 802 can be set to gserial or cdc_acm to enable your device to 803 appear to a USB host as a Linux gserial device or a 804 Common Device Class Abstract Control Model serial device. 805 If you select usbtty = gserial you should be able to enumerate 806 a Linux host by 807 # modprobe usbserial vendor=0xVendorID product=0xProductID 808 else if using cdc_acm, simply setting the environment 809 variable usbtty to be cdc_acm should suffice. The following 810 might be defined in YourBoardName.h 811 812 CONFIG_USB_DEVICE 813 Define this to build a UDC device 814 815 CONFIG_USB_TTY 816 Define this to have a tty type of device available to 817 talk to the UDC device 818 819 CFG_CONSOLE_IS_IN_ENV 820 Define this if you want stdin, stdout &/or stderr to 821 be set to usbtty. 822 823 mpc8xx: 824 CFG_USB_EXTC_CLK 0xBLAH 825 Derive USB clock from external clock "blah" 826 - CFG_USB_EXTC_CLK 0x02 827 828 CFG_USB_BRG_CLK 0xBLAH 829 Derive USB clock from brgclk 830 - CFG_USB_BRG_CLK 0x04 831 832 If you have a USB-IF assigned VendorID then you may wish to 833 define your own vendor specific values either in BoardName.h 834 or directly in usbd_vendor_info.h. If you don't define 835 CONFIG_USBD_MANUFACTURER, CONFIG_USBD_PRODUCT_NAME, 836 CONFIG_USBD_VENDORID and CONFIG_USBD_PRODUCTID, then U-Boot 837 should pretend to be a Linux device to it's target host. 838 839 CONFIG_USBD_MANUFACTURER 840 Define this string as the name of your company for 841 - CONFIG_USBD_MANUFACTURER "my company" 842 843 CONFIG_USBD_PRODUCT_NAME 844 Define this string as the name of your product 845 - CONFIG_USBD_PRODUCT_NAME "acme usb device" 846 847 CONFIG_USBD_VENDORID 848 Define this as your assigned Vendor ID from the USB 849 Implementors Forum. This *must* be a genuine Vendor ID 850 to avoid polluting the USB namespace. 851 - CONFIG_USBD_VENDORID 0xFFFF 852 853 CONFIG_USBD_PRODUCTID 854 Define this as the unique Product ID 855 for your device 856 - CONFIG_USBD_PRODUCTID 0xFFFF 857 858 859- MMC Support: 860 The MMC controller on the Intel PXA is supported. To 861 enable this define CONFIG_MMC. The MMC can be 862 accessed from the boot prompt by mapping the device 863 to physical memory similar to flash. Command line is 864 enabled with CONFIG_CMD_MMC. The MMC driver also works with 865 the FAT fs. This is enabled with CONFIG_CMD_FAT. 866 867- Journaling Flash filesystem support: 868 CONFIG_JFFS2_NAND, CONFIG_JFFS2_NAND_OFF, CONFIG_JFFS2_NAND_SIZE, 869 CONFIG_JFFS2_NAND_DEV 870 Define these for a default partition on a NAND device 871 872 CFG_JFFS2_FIRST_SECTOR, 873 CFG_JFFS2_FIRST_BANK, CFG_JFFS2_NUM_BANKS 874 Define these for a default partition on a NOR device 875 876 CFG_JFFS_CUSTOM_PART 877 Define this to create an own partition. You have to provide a 878 function struct part_info* jffs2_part_info(int part_num) 879 880 If you define only one JFFS2 partition you may also want to 881 #define CFG_JFFS_SINGLE_PART 1 882 to disable the command chpart. This is the default when you 883 have not defined a custom partition 884 885- Keyboard Support: 886 CONFIG_ISA_KEYBOARD 887 888 Define this to enable standard (PC-Style) keyboard 889 support 890 891 CONFIG_I8042_KBD 892 Standard PC keyboard driver with US (is default) and 893 GERMAN key layout (switch via environment 'keymap=de') support. 894 Export function i8042_kbd_init, i8042_tstc and i8042_getc 895 for cfb_console. Supports cursor blinking. 896 897- Video support: 898 CONFIG_VIDEO 899 900 Define this to enable video support (for output to 901 video). 902 903 CONFIG_VIDEO_CT69000 904 905 Enable Chips & Technologies 69000 Video chip 906 907 CONFIG_VIDEO_SMI_LYNXEM 908 Enable Silicon Motion SMI 712/710/810 Video chip. The 909 video output is selected via environment 'videoout' 910 (1 = LCD and 2 = CRT). If videoout is undefined, CRT is 911 assumed. 912 913 For the CT69000 and SMI_LYNXEM drivers, videomode is 914 selected via environment 'videomode'. Two diferent ways 915 are possible: 916 - "videomode=num" 'num' is a standard LiLo mode numbers. 917 Following standard modes are supported (* is default): 918 919 Colors 640x480 800x600 1024x768 1152x864 1280x1024 920 -------------+--------------------------------------------- 921 8 bits | 0x301* 0x303 0x305 0x161 0x307 922 15 bits | 0x310 0x313 0x316 0x162 0x319 923 16 bits | 0x311 0x314 0x317 0x163 0x31A 924 24 bits | 0x312 0x315 0x318 ? 0x31B 925 -------------+--------------------------------------------- 926 (i.e. setenv videomode 317; saveenv; reset;) 927 928 - "videomode=bootargs" all the video parameters are parsed 929 from the bootargs. (See drivers/video/videomodes.c) 930 931 932 CONFIG_VIDEO_SED13806 933 Enable Epson SED13806 driver. This driver supports 8bpp 934 and 16bpp modes defined by CONFIG_VIDEO_SED13806_8BPP 935 or CONFIG_VIDEO_SED13806_16BPP 936 937- Keyboard Support: 938 CONFIG_KEYBOARD 939 940 Define this to enable a custom keyboard support. 941 This simply calls drv_keyboard_init() which must be 942 defined in your board-specific files. 943 The only board using this so far is RBC823. 944 945- LCD Support: CONFIG_LCD 946 947 Define this to enable LCD support (for output to LCD 948 display); also select one of the supported displays 949 by defining one of these: 950 951 CONFIG_NEC_NL6448AC33: 952 953 NEC NL6448AC33-18. Active, color, single scan. 954 955 CONFIG_NEC_NL6448BC20 956 957 NEC NL6448BC20-08. 6.5", 640x480. 958 Active, color, single scan. 959 960 CONFIG_NEC_NL6448BC33_54 961 962 NEC NL6448BC33-54. 10.4", 640x480. 963 Active, color, single scan. 964 965 CONFIG_SHARP_16x9 966 967 Sharp 320x240. Active, color, single scan. 968 It isn't 16x9, and I am not sure what it is. 969 970 CONFIG_SHARP_LQ64D341 971 972 Sharp LQ64D341 display, 640x480. 973 Active, color, single scan. 974 975 CONFIG_HLD1045 976 977 HLD1045 display, 640x480. 978 Active, color, single scan. 979 980 CONFIG_OPTREX_BW 981 982 Optrex CBL50840-2 NF-FW 99 22 M5 983 or 984 Hitachi LMG6912RPFC-00T 985 or 986 Hitachi SP14Q002 987 988 320x240. Black & white. 989 990 Normally display is black on white background; define 991 CFG_WHITE_ON_BLACK to get it inverted. 992 993- Splash Screen Support: CONFIG_SPLASH_SCREEN 994 995 If this option is set, the environment is checked for 996 a variable "splashimage". If found, the usual display 997 of logo, copyright and system information on the LCD 998 is suppressed and the BMP image at the address 999 specified in "splashimage" is loaded instead. The 1000 console is redirected to the "nulldev", too. This 1001 allows for a "silent" boot where a splash screen is 1002 loaded very quickly after power-on. 1003 1004- Gzip compressed BMP image support: CONFIG_VIDEO_BMP_GZIP 1005 1006 If this option is set, additionally to standard BMP 1007 images, gzipped BMP images can be displayed via the 1008 splashscreen support or the bmp command. 1009 1010- Compression support: 1011 CONFIG_BZIP2 1012 1013 If this option is set, support for bzip2 compressed 1014 images is included. If not, only uncompressed and gzip 1015 compressed images are supported. 1016 1017 NOTE: the bzip2 algorithm requires a lot of RAM, so 1018 the malloc area (as defined by CFG_MALLOC_LEN) should 1019 be at least 4MB. 1020 1021- MII/PHY support: 1022 CONFIG_PHY_ADDR 1023 1024 The address of PHY on MII bus. 1025 1026 CONFIG_PHY_CLOCK_FREQ (ppc4xx) 1027 1028 The clock frequency of the MII bus 1029 1030 CONFIG_PHY_GIGE 1031 1032 If this option is set, support for speed/duplex 1033 detection of Gigabit PHY is included. 1034 1035 CONFIG_PHY_RESET_DELAY 1036 1037 Some PHY like Intel LXT971A need extra delay after 1038 reset before any MII register access is possible. 1039 For such PHY, set this option to the usec delay 1040 required. (minimum 300usec for LXT971A) 1041 1042 CONFIG_PHY_CMD_DELAY (ppc4xx) 1043 1044 Some PHY like Intel LXT971A need extra delay after 1045 command issued before MII status register can be read 1046 1047- Ethernet address: 1048 CONFIG_ETHADDR 1049 CONFIG_ETH2ADDR 1050 CONFIG_ETH3ADDR 1051 1052 Define a default value for ethernet address to use 1053 for the respective ethernet interface, in case this 1054 is not determined automatically. 1055 1056- IP address: 1057 CONFIG_IPADDR 1058 1059 Define a default value for the IP address to use for 1060 the default ethernet interface, in case this is not 1061 determined through e.g. bootp. 1062 1063- Server IP address: 1064 CONFIG_SERVERIP 1065 1066 Defines a default value for theIP address of a TFTP 1067 server to contact when using the "tftboot" command. 1068 1069- Multicast TFTP Mode: 1070 CONFIG_MCAST_TFTP 1071 1072 Defines whether you want to support multicast TFTP as per 1073 rfc-2090; for example to work with atftp. Lets lots of targets 1074 tftp down the same boot image concurrently. Note: the ethernet 1075 driver in use must provide a function: mcast() to join/leave a 1076 multicast group. 1077 1078 CONFIG_BOOTP_RANDOM_DELAY 1079- BOOTP Recovery Mode: 1080 CONFIG_BOOTP_RANDOM_DELAY 1081 1082 If you have many targets in a network that try to 1083 boot using BOOTP, you may want to avoid that all 1084 systems send out BOOTP requests at precisely the same 1085 moment (which would happen for instance at recovery 1086 from a power failure, when all systems will try to 1087 boot, thus flooding the BOOTP server. Defining 1088 CONFIG_BOOTP_RANDOM_DELAY causes a random delay to be 1089 inserted before sending out BOOTP requests. The 1090 following delays are inserted then: 1091 1092 1st BOOTP request: delay 0 ... 1 sec 1093 2nd BOOTP request: delay 0 ... 2 sec 1094 3rd BOOTP request: delay 0 ... 4 sec 1095 4th and following 1096 BOOTP requests: delay 0 ... 8 sec 1097 1098- DHCP Advanced Options: 1099 You can fine tune the DHCP functionality by defining 1100 CONFIG_BOOTP_* symbols: 1101 1102 CONFIG_BOOTP_SUBNETMASK 1103 CONFIG_BOOTP_GATEWAY 1104 CONFIG_BOOTP_HOSTNAME 1105 CONFIG_BOOTP_NISDOMAIN 1106 CONFIG_BOOTP_BOOTPATH 1107 CONFIG_BOOTP_BOOTFILESIZE 1108 CONFIG_BOOTP_DNS 1109 CONFIG_BOOTP_DNS2 1110 CONFIG_BOOTP_SEND_HOSTNAME 1111 CONFIG_BOOTP_NTPSERVER 1112 CONFIG_BOOTP_TIMEOFFSET 1113 CONFIG_BOOTP_VENDOREX 1114 1115 CONFIG_BOOTP_SERVERIP - TFTP server will be the serverip 1116 environment variable, not the BOOTP server. 1117 1118 CONFIG_BOOTP_DNS2 - If a DHCP client requests the DNS 1119 serverip from a DHCP server, it is possible that more 1120 than one DNS serverip is offered to the client. 1121 If CONFIG_BOOTP_DNS2 is enabled, the secondary DNS 1122 serverip will be stored in the additional environment 1123 variable "dnsip2". The first DNS serverip is always 1124 stored in the variable "dnsip", when CONFIG_BOOTP_DNS 1125 is defined. 1126 1127 CONFIG_BOOTP_SEND_HOSTNAME - Some DHCP servers are capable 1128 to do a dynamic update of a DNS server. To do this, they 1129 need the hostname of the DHCP requester. 1130 If CONFIG_BOOTP_SEND_HOSTNAME is defined, the content 1131 of the "hostname" environment variable is passed as 1132 option 12 to the DHCP server. 1133 1134 - CDP Options: 1135 CONFIG_CDP_DEVICE_ID 1136 1137 The device id used in CDP trigger frames. 1138 1139 CONFIG_CDP_DEVICE_ID_PREFIX 1140 1141 A two character string which is prefixed to the MAC address 1142 of the device. 1143 1144 CONFIG_CDP_PORT_ID 1145 1146 A printf format string which contains the ascii name of 1147 the port. Normally is set to "eth%d" which sets 1148 eth0 for the first ethernet, eth1 for the second etc. 1149 1150 CONFIG_CDP_CAPABILITIES 1151 1152 A 32bit integer which indicates the device capabilities; 1153 0x00000010 for a normal host which does not forwards. 1154 1155 CONFIG_CDP_VERSION 1156 1157 An ascii string containing the version of the software. 1158 1159 CONFIG_CDP_PLATFORM 1160 1161 An ascii string containing the name of the platform. 1162 1163 CONFIG_CDP_TRIGGER 1164 1165 A 32bit integer sent on the trigger. 1166 1167 CONFIG_CDP_POWER_CONSUMPTION 1168 1169 A 16bit integer containing the power consumption of the 1170 device in .1 of milliwatts. 1171 1172 CONFIG_CDP_APPLIANCE_VLAN_TYPE 1173 1174 A byte containing the id of the VLAN. 1175 1176- Status LED: CONFIG_STATUS_LED 1177 1178 Several configurations allow to display the current 1179 status using a LED. For instance, the LED will blink 1180 fast while running U-Boot code, stop blinking as 1181 soon as a reply to a BOOTP request was received, and 1182 start blinking slow once the Linux kernel is running 1183 (supported by a status LED driver in the Linux 1184 kernel). Defining CONFIG_STATUS_LED enables this 1185 feature in U-Boot. 1186 1187- CAN Support: CONFIG_CAN_DRIVER 1188 1189 Defining CONFIG_CAN_DRIVER enables CAN driver support 1190 on those systems that support this (optional) 1191 feature, like the TQM8xxL modules. 1192 1193- I2C Support: CONFIG_HARD_I2C | CONFIG_SOFT_I2C 1194 1195 These enable I2C serial bus commands. Defining either of 1196 (but not both of) CONFIG_HARD_I2C or CONFIG_SOFT_I2C will 1197 include the appropriate I2C driver for the selected cpu. 1198 1199 This will allow you to use i2c commands at the u-boot 1200 command line (as long as you set CONFIG_CMD_I2C in 1201 CONFIG_COMMANDS) and communicate with i2c based realtime 1202 clock chips. See common/cmd_i2c.c for a description of the 1203 command line interface. 1204 1205 CONFIG_I2C_CMD_TREE is a recommended option that places 1206 all I2C commands under a single 'i2c' root command. The 1207 older 'imm', 'imd', 'iprobe' etc. commands are considered 1208 deprecated and may disappear in the future. 1209 1210 CONFIG_HARD_I2C selects a hardware I2C controller. 1211 1212 CONFIG_SOFT_I2C configures u-boot to use a software (aka 1213 bit-banging) driver instead of CPM or similar hardware 1214 support for I2C. 1215 1216 There are several other quantities that must also be 1217 defined when you define CONFIG_HARD_I2C or CONFIG_SOFT_I2C. 1218 1219 In both cases you will need to define CFG_I2C_SPEED 1220 to be the frequency (in Hz) at which you wish your i2c bus 1221 to run and CFG_I2C_SLAVE to be the address of this node (ie 1222 the cpu's i2c node address). 1223 1224 Now, the u-boot i2c code for the mpc8xx (cpu/mpc8xx/i2c.c) 1225 sets the cpu up as a master node and so its address should 1226 therefore be cleared to 0 (See, eg, MPC823e User's Manual 1227 p.16-473). So, set CFG_I2C_SLAVE to 0. 1228 1229 That's all that's required for CONFIG_HARD_I2C. 1230 1231 If you use the software i2c interface (CONFIG_SOFT_I2C) 1232 then the following macros need to be defined (examples are 1233 from include/configs/lwmon.h): 1234 1235 I2C_INIT 1236 1237 (Optional). Any commands necessary to enable the I2C 1238 controller or configure ports. 1239 1240 eg: #define I2C_INIT (immr->im_cpm.cp_pbdir |= PB_SCL) 1241 1242 I2C_PORT 1243 1244 (Only for MPC8260 CPU). The I/O port to use (the code 1245 assumes both bits are on the same port). Valid values 1246 are 0..3 for ports A..D. 1247 1248 I2C_ACTIVE 1249 1250 The code necessary to make the I2C data line active 1251 (driven). If the data line is open collector, this 1252 define can be null. 1253 1254 eg: #define I2C_ACTIVE (immr->im_cpm.cp_pbdir |= PB_SDA) 1255 1256 I2C_TRISTATE 1257 1258 The code necessary to make the I2C data line tri-stated 1259 (inactive). If the data line is open collector, this 1260 define can be null. 1261 1262 eg: #define I2C_TRISTATE (immr->im_cpm.cp_pbdir &= ~PB_SDA) 1263 1264 I2C_READ 1265 1266 Code that returns TRUE if the I2C data line is high, 1267 FALSE if it is low. 1268 1269 eg: #define I2C_READ ((immr->im_cpm.cp_pbdat & PB_SDA) != 0) 1270 1271 I2C_SDA(bit) 1272 1273 If <bit> is TRUE, sets the I2C data line high. If it 1274 is FALSE, it clears it (low). 1275 1276 eg: #define I2C_SDA(bit) \ 1277 if(bit) immr->im_cpm.cp_pbdat |= PB_SDA; \ 1278 else immr->im_cpm.cp_pbdat &= ~PB_SDA 1279 1280 I2C_SCL(bit) 1281 1282 If <bit> is TRUE, sets the I2C clock line high. If it 1283 is FALSE, it clears it (low). 1284 1285 eg: #define I2C_SCL(bit) \ 1286 if(bit) immr->im_cpm.cp_pbdat |= PB_SCL; \ 1287 else immr->im_cpm.cp_pbdat &= ~PB_SCL 1288 1289 I2C_DELAY 1290 1291 This delay is invoked four times per clock cycle so this 1292 controls the rate of data transfer. The data rate thus 1293 is 1 / (I2C_DELAY * 4). Often defined to be something 1294 like: 1295 1296 #define I2C_DELAY udelay(2) 1297 1298 CFG_I2C_INIT_BOARD 1299 1300 When a board is reset during an i2c bus transfer 1301 chips might think that the current transfer is still 1302 in progress. On some boards it is possible to access 1303 the i2c SCLK line directly, either by using the 1304 processor pin as a GPIO or by having a second pin 1305 connected to the bus. If this option is defined a 1306 custom i2c_init_board() routine in boards/xxx/board.c 1307 is run early in the boot sequence. 1308 1309 CONFIG_I2CFAST (PPC405GP|PPC405EP only) 1310 1311 This option enables configuration of bi_iic_fast[] flags 1312 in u-boot bd_info structure based on u-boot environment 1313 variable "i2cfast". (see also i2cfast) 1314 1315 CONFIG_I2C_MULTI_BUS 1316 1317 This option allows the use of multiple I2C buses, each of which 1318 must have a controller. At any point in time, only one bus is 1319 active. To switch to a different bus, use the 'i2c dev' command. 1320 Note that bus numbering is zero-based. 1321 1322 CFG_I2C_NOPROBES 1323 1324 This option specifies a list of I2C devices that will be skipped 1325 when the 'i2c probe' command is issued (or 'iprobe' using the legacy 1326 command). If CONFIG_I2C_MULTI_BUS is set, specify a list of bus-device 1327 pairs. Otherwise, specify a 1D array of device addresses 1328 1329 e.g. 1330 #undef CONFIG_I2C_MULTI_BUS 1331 #define CFG_I2C_NOPROBES {0x50,0x68} 1332 1333 will skip addresses 0x50 and 0x68 on a board with one I2C bus 1334 1335 #define CONFIG_I2C_MULTI_BUS 1336 #define CFG_I2C_MULTI_NOPROBES {{0,0x50},{0,0x68},{1,0x54}} 1337 1338 will skip addresses 0x50 and 0x68 on bus 0 and address 0x54 on bus 1 1339 1340 CFG_SPD_BUS_NUM 1341 1342 If defined, then this indicates the I2C bus number for DDR SPD. 1343 If not defined, then U-Boot assumes that SPD is on I2C bus 0. 1344 1345 CFG_RTC_BUS_NUM 1346 1347 If defined, then this indicates the I2C bus number for the RTC. 1348 If not defined, then U-Boot assumes that RTC is on I2C bus 0. 1349 1350 CFG_DTT_BUS_NUM 1351 1352 If defined, then this indicates the I2C bus number for the DTT. 1353 If not defined, then U-Boot assumes that DTT is on I2C bus 0. 1354 1355 CONFIG_FSL_I2C 1356 1357 Define this option if you want to use Freescale's I2C driver in 1358 drivers/i2c/fsl_i2c.c. 1359 1360 1361- SPI Support: CONFIG_SPI 1362 1363 Enables SPI driver (so far only tested with 1364 SPI EEPROM, also an instance works with Crystal A/D and 1365 D/As on the SACSng board) 1366 1367 CONFIG_SPI_X 1368 1369 Enables extended (16-bit) SPI EEPROM addressing. 1370 (symmetrical to CONFIG_I2C_X) 1371 1372 CONFIG_SOFT_SPI 1373 1374 Enables a software (bit-bang) SPI driver rather than 1375 using hardware support. This is a general purpose 1376 driver that only requires three general I/O port pins 1377 (two outputs, one input) to function. If this is 1378 defined, the board configuration must define several 1379 SPI configuration items (port pins to use, etc). For 1380 an example, see include/configs/sacsng.h. 1381 1382 CONFIG_HARD_SPI 1383 1384 Enables a hardware SPI driver for general-purpose reads 1385 and writes. As with CONFIG_SOFT_SPI, the board configuration 1386 must define a list of chip-select function pointers. 1387 Currently supported on some MPC8xxx processors. For an 1388 example, see include/configs/mpc8349emds.h. 1389 1390- FPGA Support: CONFIG_FPGA 1391 1392 Enables FPGA subsystem. 1393 1394 CONFIG_FPGA_<vendor> 1395 1396 Enables support for specific chip vendors. 1397 (ALTERA, XILINX) 1398 1399 CONFIG_FPGA_<family> 1400 1401 Enables support for FPGA family. 1402 (SPARTAN2, SPARTAN3, VIRTEX2, CYCLONE2, ACEX1K, ACEX) 1403 1404 CONFIG_FPGA_COUNT 1405 1406 Specify the number of FPGA devices to support. 1407 1408 CFG_FPGA_PROG_FEEDBACK 1409 1410 Enable printing of hash marks during FPGA configuration. 1411 1412 CFG_FPGA_CHECK_BUSY 1413 1414 Enable checks on FPGA configuration interface busy 1415 status by the configuration function. This option 1416 will require a board or device specific function to 1417 be written. 1418 1419 CONFIG_FPGA_DELAY 1420 1421 If defined, a function that provides delays in the FPGA 1422 configuration driver. 1423 1424 CFG_FPGA_CHECK_CTRLC 1425 Allow Control-C to interrupt FPGA configuration 1426 1427 CFG_FPGA_CHECK_ERROR 1428 1429 Check for configuration errors during FPGA bitfile 1430 loading. For example, abort during Virtex II 1431 configuration if the INIT_B line goes low (which 1432 indicated a CRC error). 1433 1434 CFG_FPGA_WAIT_INIT 1435 1436 Maximum time to wait for the INIT_B line to deassert 1437 after PROB_B has been deasserted during a Virtex II 1438 FPGA configuration sequence. The default time is 500 1439 mS. 1440 1441 CFG_FPGA_WAIT_BUSY 1442 1443 Maximum time to wait for BUSY to deassert during 1444 Virtex II FPGA configuration. The default is 5 mS. 1445 1446 CFG_FPGA_WAIT_CONFIG 1447 1448 Time to wait after FPGA configuration. The default is 1449 200 mS. 1450 1451- Configuration Management: 1452 CONFIG_IDENT_STRING 1453 1454 If defined, this string will be added to the U-Boot 1455 version information (U_BOOT_VERSION) 1456 1457- Vendor Parameter Protection: 1458 1459 U-Boot considers the values of the environment 1460 variables "serial#" (Board Serial Number) and 1461 "ethaddr" (Ethernet Address) to be parameters that 1462 are set once by the board vendor / manufacturer, and 1463 protects these variables from casual modification by 1464 the user. Once set, these variables are read-only, 1465 and write or delete attempts are rejected. You can 1466 change this behviour: 1467 1468 If CONFIG_ENV_OVERWRITE is #defined in your config 1469 file, the write protection for vendor parameters is 1470 completely disabled. Anybody can change or delete 1471 these parameters. 1472 1473 Alternatively, if you #define _both_ CONFIG_ETHADDR 1474 _and_ CONFIG_OVERWRITE_ETHADDR_ONCE, a default 1475 ethernet address is installed in the environment, 1476 which can be changed exactly ONCE by the user. [The 1477 serial# is unaffected by this, i. e. it remains 1478 read-only.] 1479 1480- Protected RAM: 1481 CONFIG_PRAM 1482 1483 Define this variable to enable the reservation of 1484 "protected RAM", i. e. RAM which is not overwritten 1485 by U-Boot. Define CONFIG_PRAM to hold the number of 1486 kB you want to reserve for pRAM. You can overwrite 1487 this default value by defining an environment 1488 variable "pram" to the number of kB you want to 1489 reserve. Note that the board info structure will 1490 still show the full amount of RAM. If pRAM is 1491 reserved, a new environment variable "mem" will 1492 automatically be defined to hold the amount of 1493 remaining RAM in a form that can be passed as boot 1494 argument to Linux, for instance like that: 1495 1496 setenv bootargs ... mem=\${mem} 1497 saveenv 1498 1499 This way you can tell Linux not to use this memory, 1500 either, which results in a memory region that will 1501 not be affected by reboots. 1502 1503 *WARNING* If your board configuration uses automatic 1504 detection of the RAM size, you must make sure that 1505 this memory test is non-destructive. So far, the 1506 following board configurations are known to be 1507 "pRAM-clean": 1508 1509 ETX094, IVMS8, IVML24, SPD8xx, TQM8xxL, 1510 HERMES, IP860, RPXlite, LWMON, LANTEC, 1511 PCU_E, FLAGADM, TQM8260 1512 1513- Error Recovery: 1514 CONFIG_PANIC_HANG 1515 1516 Define this variable to stop the system in case of a 1517 fatal error, so that you have to reset it manually. 1518 This is probably NOT a good idea for an embedded 1519 system where you want to system to reboot 1520 automatically as fast as possible, but it may be 1521 useful during development since you can try to debug 1522 the conditions that lead to the situation. 1523 1524 CONFIG_NET_RETRY_COUNT 1525 1526 This variable defines the number of retries for 1527 network operations like ARP, RARP, TFTP, or BOOTP 1528 before giving up the operation. If not defined, a 1529 default value of 5 is used. 1530 1531- Command Interpreter: 1532 CONFIG_AUTO_COMPLETE 1533 1534 Enable auto completion of commands using TAB. 1535 1536 Note that this feature has NOT been implemented yet 1537 for the "hush" shell. 1538 1539 1540 CFG_HUSH_PARSER 1541 1542 Define this variable to enable the "hush" shell (from 1543 Busybox) as command line interpreter, thus enabling 1544 powerful command line syntax like 1545 if...then...else...fi conditionals or `&&' and '||' 1546 constructs ("shell scripts"). 1547 1548 If undefined, you get the old, much simpler behaviour 1549 with a somewhat smaller memory footprint. 1550 1551 1552 CFG_PROMPT_HUSH_PS2 1553 1554 This defines the secondary prompt string, which is 1555 printed when the command interpreter needs more input 1556 to complete a command. Usually "> ". 1557 1558 Note: 1559 1560 In the current implementation, the local variables 1561 space and global environment variables space are 1562 separated. Local variables are those you define by 1563 simply typing `name=value'. To access a local 1564 variable later on, you have write `$name' or 1565 `${name}'; to execute the contents of a variable 1566 directly type `$name' at the command prompt. 1567 1568 Global environment variables are those you use 1569 setenv/printenv to work with. To run a command stored 1570 in such a variable, you need to use the run command, 1571 and you must not use the '$' sign to access them. 1572 1573 To store commands and special characters in a 1574 variable, please use double quotation marks 1575 surrounding the whole text of the variable, instead 1576 of the backslashes before semicolons and special 1577 symbols. 1578 1579- Commandline Editing and History: 1580 CONFIG_CMDLINE_EDITING 1581 1582 Enable editiong and History functions for interactive 1583 commandline input operations 1584 1585- Default Environment: 1586 CONFIG_EXTRA_ENV_SETTINGS 1587 1588 Define this to contain any number of null terminated 1589 strings (variable = value pairs) that will be part of 1590 the default environment compiled into the boot image. 1591 1592 For example, place something like this in your 1593 board's config file: 1594 1595 #define CONFIG_EXTRA_ENV_SETTINGS \ 1596 "myvar1=value1\0" \ 1597 "myvar2=value2\0" 1598 1599 Warning: This method is based on knowledge about the 1600 internal format how the environment is stored by the 1601 U-Boot code. This is NOT an official, exported 1602 interface! Although it is unlikely that this format 1603 will change soon, there is no guarantee either. 1604 You better know what you are doing here. 1605 1606 Note: overly (ab)use of the default environment is 1607 discouraged. Make sure to check other ways to preset 1608 the environment like the autoscript function or the 1609 boot command first. 1610 1611- DataFlash Support: 1612 CONFIG_HAS_DATAFLASH 1613 1614 Defining this option enables DataFlash features and 1615 allows to read/write in Dataflash via the standard 1616 commands cp, md... 1617 1618- SystemACE Support: 1619 CONFIG_SYSTEMACE 1620 1621 Adding this option adds support for Xilinx SystemACE 1622 chips attached via some sort of local bus. The address 1623 of the chip must alsh be defined in the 1624 CFG_SYSTEMACE_BASE macro. For example: 1625 1626 #define CONFIG_SYSTEMACE 1627 #define CFG_SYSTEMACE_BASE 0xf0000000 1628 1629 When SystemACE support is added, the "ace" device type 1630 becomes available to the fat commands, i.e. fatls. 1631 1632- TFTP Fixed UDP Port: 1633 CONFIG_TFTP_PORT 1634 1635 If this is defined, the environment variable tftpsrcp 1636 is used to supply the TFTP UDP source port value. 1637 If tftpsrcp isn't defined, the normal pseudo-random port 1638 number generator is used. 1639 1640 Also, the environment variable tftpdstp is used to supply 1641 the TFTP UDP destination port value. If tftpdstp isn't 1642 defined, the normal port 69 is used. 1643 1644 The purpose for tftpsrcp is to allow a TFTP server to 1645 blindly start the TFTP transfer using the pre-configured 1646 target IP address and UDP port. This has the effect of 1647 "punching through" the (Windows XP) firewall, allowing 1648 the remainder of the TFTP transfer to proceed normally. 1649 A better solution is to properly configure the firewall, 1650 but sometimes that is not allowed. 1651 1652- Show boot progress: 1653 CONFIG_SHOW_BOOT_PROGRESS 1654 1655 Defining this option allows to add some board- 1656 specific code (calling a user-provided function 1657 "show_boot_progress(int)") that enables you to show 1658 the system's boot progress on some display (for 1659 example, some LED's) on your board. At the moment, 1660 the following checkpoints are implemented: 1661 1662Legacy uImage format: 1663 1664 Arg Where When 1665 1 common/cmd_bootm.c before attempting to boot an image 1666 -1 common/cmd_bootm.c Image header has bad magic number 1667 2 common/cmd_bootm.c Image header has correct magic number 1668 -2 common/cmd_bootm.c Image header has bad checksum 1669 3 common/cmd_bootm.c Image header has correct checksum 1670 -3 common/cmd_bootm.c Image data has bad checksum 1671 4 common/cmd_bootm.c Image data has correct checksum 1672 -4 common/cmd_bootm.c Image is for unsupported architecture 1673 5 common/cmd_bootm.c Architecture check OK 1674 -5 common/cmd_bootm.c Wrong Image Type (not kernel, multi) 1675 6 common/cmd_bootm.c Image Type check OK 1676 -6 common/cmd_bootm.c gunzip uncompression error 1677 -7 common/cmd_bootm.c Unimplemented compression type 1678 7 common/cmd_bootm.c Uncompression OK 1679 8 common/cmd_bootm.c No uncompress/copy overwrite error 1680 -9 common/cmd_bootm.c Unsupported OS (not Linux, BSD, VxWorks, QNX) 1681 1682 9 common/image.c Start initial ramdisk verification 1683 -10 common/image.c Ramdisk header has bad magic number 1684 -11 common/image.c Ramdisk header has bad checksum 1685 10 common/image.c Ramdisk header is OK 1686 -12 common/image.c Ramdisk data has bad checksum 1687 11 common/image.c Ramdisk data has correct checksum 1688 12 common/image.c Ramdisk verification complete, start loading 1689 -13 common/image.c Wrong Image Type (not PPC Linux Ramdisk) 1690 13 common/image.c Start multifile image verification 1691 14 common/image.c No initial ramdisk, no multifile, continue. 1692 1693 15 lib_<arch>/bootm.c All preparation done, transferring control to OS 1694 1695 -30 lib_ppc/board.c Fatal error, hang the system 1696 -31 post/post.c POST test failed, detected by post_output_backlog() 1697 -32 post/post.c POST test failed, detected by post_run_single() 1698 1699 34 common/cmd_doc.c before loading a Image from a DOC device 1700 -35 common/cmd_doc.c Bad usage of "doc" command 1701 35 common/cmd_doc.c correct usage of "doc" command 1702 -36 common/cmd_doc.c No boot device 1703 36 common/cmd_doc.c correct boot device 1704 -37 common/cmd_doc.c Unknown Chip ID on boot device 1705 37 common/cmd_doc.c correct chip ID found, device available 1706 -38 common/cmd_doc.c Read Error on boot device 1707 38 common/cmd_doc.c reading Image header from DOC device OK 1708 -39 common/cmd_doc.c Image header has bad magic number 1709 39 common/cmd_doc.c Image header has correct magic number 1710 -40 common/cmd_doc.c Error reading Image from DOC device 1711 40 common/cmd_doc.c Image header has correct magic number 1712 41 common/cmd_ide.c before loading a Image from a IDE device 1713 -42 common/cmd_ide.c Bad usage of "ide" command 1714 42 common/cmd_ide.c correct usage of "ide" command 1715 -43 common/cmd_ide.c No boot device 1716 43 common/cmd_ide.c boot device found 1717 -44 common/cmd_ide.c Device not available 1718 44 common/cmd_ide.c Device available 1719 -45 common/cmd_ide.c wrong partition selected 1720 45 common/cmd_ide.c partition selected 1721 -46 common/cmd_ide.c Unknown partition table 1722 46 common/cmd_ide.c valid partition table found 1723 -47 common/cmd_ide.c Invalid partition type 1724 47 common/cmd_ide.c correct partition type 1725 -48 common/cmd_ide.c Error reading Image Header on boot device 1726 48 common/cmd_ide.c reading Image Header from IDE device OK 1727 -49 common/cmd_ide.c Image header has bad magic number 1728 49 common/cmd_ide.c Image header has correct magic number 1729 -50 common/cmd_ide.c Image header has bad checksum 1730 50 common/cmd_ide.c Image header has correct checksum 1731 -51 common/cmd_ide.c Error reading Image from IDE device 1732 51 common/cmd_ide.c reading Image from IDE device OK 1733 52 common/cmd_nand.c before loading a Image from a NAND device 1734 -53 common/cmd_nand.c Bad usage of "nand" command 1735 53 common/cmd_nand.c correct usage of "nand" command 1736 -54 common/cmd_nand.c No boot device 1737 54 common/cmd_nand.c boot device found 1738 -55 common/cmd_nand.c Unknown Chip ID on boot device 1739 55 common/cmd_nand.c correct chip ID found, device available 1740 -56 common/cmd_nand.c Error reading Image Header on boot device 1741 56 common/cmd_nand.c reading Image Header from NAND device OK 1742 -57 common/cmd_nand.c Image header has bad magic number 1743 57 common/cmd_nand.c Image header has correct magic number 1744 -58 common/cmd_nand.c Error reading Image from NAND device 1745 58 common/cmd_nand.c reading Image from NAND device OK 1746 1747 -60 common/env_common.c Environment has a bad CRC, using default 1748 1749 64 net/eth.c starting with Ethernetconfiguration. 1750 -64 net/eth.c no Ethernet found. 1751 65 net/eth.c Ethernet found. 1752 1753 -80 common/cmd_net.c usage wrong 1754 80 common/cmd_net.c before calling NetLoop() 1755 -81 common/cmd_net.c some error in NetLoop() occured 1756 81 common/cmd_net.c NetLoop() back without error 1757 -82 common/cmd_net.c size == 0 (File with size 0 loaded) 1758 82 common/cmd_net.c trying automatic boot 1759 83 common/cmd_net.c running autoscript 1760 -83 common/cmd_net.c some error in automatic boot or autoscript 1761 84 common/cmd_net.c end without errors 1762 1763FIT uImage format: 1764 1765 Arg Where When 1766 100 common/cmd_bootm.c Kernel FIT Image has correct format 1767 -100 common/cmd_bootm.c Kernel FIT Image has incorrect format 1768 101 common/cmd_bootm.c No Kernel subimage unit name, using configuration 1769 -101 common/cmd_bootm.c Can't get configuration for kernel subimage 1770 102 common/cmd_bootm.c Kernel unit name specified 1771 -103 common/cmd_bootm.c Can't get kernel subimage node offset 1772 103 common/cmd_bootm.c Found configuration node 1773 104 common/cmd_bootm.c Got kernel subimage node offset 1774 -104 common/cmd_bootm.c Kernel subimage hash verification failed 1775 105 common/cmd_bootm.c Kernel subimage hash verification OK 1776 -105 common/cmd_bootm.c Kernel subimage is for unsupported architecture 1777 106 common/cmd_bootm.c Architecture check OK 1778 -106 common/cmd_bootm.c Kernel subimage has wrong typea 1779 107 common/cmd_bootm.c Kernel subimge type OK 1780 -107 common/cmd_bootm.c Can't get kernel subimage data/size 1781 108 common/cmd_bootm.c Got kernel subimage data/size 1782 -108 common/cmd_bootm.c Wrong image type (not legacy, FIT) 1783 -109 common/cmd_bootm.c Can't get kernel subimage type 1784 -110 common/cmd_bootm.c Can't get kernel subimage comp 1785 -111 common/cmd_bootm.c Can't get kernel subimage os 1786 -112 common/cmd_bootm.c Can't get kernel subimage load address 1787 -113 common/cmd_bootm.c Image uncompress/copy overwrite error 1788 1789 120 common/image.c Start initial ramdisk verification 1790 -120 common/image.c Ramdisk FIT image has incorrect format 1791 121 common/image.c Ramdisk FIT image has correct format 1792 122 common/image.c No Ramdisk subimage unit name, using configuration 1793 -122 common/image.c Can't get configuration for ramdisk subimage 1794 123 common/image.c Ramdisk unit name specified 1795 -124 common/image.c Can't get ramdisk subimage node offset 1796 125 common/image.c Got ramdisk subimage node offset 1797 -125 common/image.c Ramdisk subimage hash verification failed 1798 126 common/image.c Ramdisk subimage hash verification OK 1799 -126 common/image.c Ramdisk subimage for unsupported architecture 1800 127 common/image.c Architecture check OK 1801 -127 common/image.c Can't get ramdisk subimage data/size 1802 128 common/image.c Got ramdisk subimage data/size 1803 129 common/image.c Can't get ramdisk load address 1804 -129 common/image.c Got ramdisk load address 1805 1806 -130 common/cmd_doc.c Icorrect FIT image format 1807 131 common/cmd_doc.c FIT image format OK 1808 1809 -140 common/cmd_ide.c Icorrect FIT image format 1810 141 common/cmd_ide.c FIT image format OK 1811 1812 -150 common/cmd_nand.c Icorrect FIT image format 1813 151 common/cmd_nand.c FIT image format OK 1814 1815 1816Modem Support: 1817-------------- 1818 1819[so far only for SMDK2400 and TRAB boards] 1820 1821- Modem support endable: 1822 CONFIG_MODEM_SUPPORT 1823 1824- RTS/CTS Flow control enable: 1825 CONFIG_HWFLOW 1826 1827- Modem debug support: 1828 CONFIG_MODEM_SUPPORT_DEBUG 1829 1830 Enables debugging stuff (char screen[1024], dbg()) 1831 for modem support. Useful only with BDI2000. 1832 1833- Interrupt support (PPC): 1834 1835 There are common interrupt_init() and timer_interrupt() 1836 for all PPC archs. interrupt_init() calls interrupt_init_cpu() 1837 for cpu specific initialization. interrupt_init_cpu() 1838 should set decrementer_count to appropriate value. If 1839 cpu resets decrementer automatically after interrupt 1840 (ppc4xx) it should set decrementer_count to zero. 1841 timer_interrupt() calls timer_interrupt_cpu() for cpu 1842 specific handling. If board has watchdog / status_led 1843 / other_activity_monitor it works automatically from 1844 general timer_interrupt(). 1845 1846- General: 1847 1848 In the target system modem support is enabled when a 1849 specific key (key combination) is pressed during 1850 power-on. Otherwise U-Boot will boot normally 1851 (autoboot). The key_pressed() fuction is called from 1852 board_init(). Currently key_pressed() is a dummy 1853 function, returning 1 and thus enabling modem 1854 initialization. 1855 1856 If there are no modem init strings in the 1857 environment, U-Boot proceed to autoboot; the 1858 previous output (banner, info printfs) will be 1859 supressed, though. 1860 1861 See also: doc/README.Modem 1862 1863 1864Configuration Settings: 1865----------------------- 1866 1867- CFG_LONGHELP: Defined when you want long help messages included; 1868 undefine this when you're short of memory. 1869 1870- CFG_PROMPT: This is what U-Boot prints on the console to 1871 prompt for user input. 1872 1873- CFG_CBSIZE: Buffer size for input from the Console 1874 1875- CFG_PBSIZE: Buffer size for Console output 1876 1877- CFG_MAXARGS: max. Number of arguments accepted for monitor commands 1878 1879- CFG_BARGSIZE: Buffer size for Boot Arguments which are passed to 1880 the application (usually a Linux kernel) when it is 1881 booted 1882 1883- CFG_BAUDRATE_TABLE: 1884 List of legal baudrate settings for this board. 1885 1886- CFG_CONSOLE_INFO_QUIET 1887 Suppress display of console information at boot. 1888 1889- CFG_CONSOLE_IS_IN_ENV 1890 If the board specific function 1891 extern int overwrite_console (void); 1892 returns 1, the stdin, stderr and stdout are switched to the 1893 serial port, else the settings in the environment are used. 1894 1895- CFG_CONSOLE_OVERWRITE_ROUTINE 1896 Enable the call to overwrite_console(). 1897 1898- CFG_CONSOLE_ENV_OVERWRITE 1899 Enable overwrite of previous console environment settings. 1900 1901- CFG_MEMTEST_START, CFG_MEMTEST_END: 1902 Begin and End addresses of the area used by the 1903 simple memory test. 1904 1905- CFG_ALT_MEMTEST: 1906 Enable an alternate, more extensive memory test. 1907 1908- CFG_MEMTEST_SCRATCH: 1909 Scratch address used by the alternate memory test 1910 You only need to set this if address zero isn't writeable 1911 1912- CFG_TFTP_LOADADDR: 1913 Default load address for network file downloads 1914 1915- CFG_LOADS_BAUD_CHANGE: 1916 Enable temporary baudrate change while serial download 1917 1918- CFG_SDRAM_BASE: 1919 Physical start address of SDRAM. _Must_ be 0 here. 1920 1921- CFG_MBIO_BASE: 1922 Physical start address of Motherboard I/O (if using a 1923 Cogent motherboard) 1924 1925- CFG_FLASH_BASE: 1926 Physical start address of Flash memory. 1927 1928- CFG_MONITOR_BASE: 1929 Physical start address of boot monitor code (set by 1930 make config files to be same as the text base address 1931 (TEXT_BASE) used when linking) - same as 1932 CFG_FLASH_BASE when booting from flash. 1933 1934- CFG_MONITOR_LEN: 1935 Size of memory reserved for monitor code, used to 1936 determine _at_compile_time_ (!) if the environment is 1937 embedded within the U-Boot image, or in a separate 1938 flash sector. 1939 1940- CFG_MALLOC_LEN: 1941 Size of DRAM reserved for malloc() use. 1942 1943- CFG_BOOTM_LEN: 1944 Normally compressed uImages are limited to an 1945 uncompressed size of 8 MBytes. If this is not enough, 1946 you can define CFG_BOOTM_LEN in your board config file 1947 to adjust this setting to your needs. 1948 1949- CFG_BOOTMAPSZ: 1950 Maximum size of memory mapped by the startup code of 1951 the Linux kernel; all data that must be processed by 1952 the Linux kernel (bd_info, boot arguments, eventually 1953 initrd image) must be put below this limit. 1954 1955- CFG_MAX_FLASH_BANKS: 1956 Max number of Flash memory banks 1957 1958- CFG_MAX_FLASH_SECT: 1959 Max number of sectors on a Flash chip 1960 1961- CFG_FLASH_ERASE_TOUT: 1962 Timeout for Flash erase operations (in ms) 1963 1964- CFG_FLASH_WRITE_TOUT: 1965 Timeout for Flash write operations (in ms) 1966 1967- CFG_FLASH_LOCK_TOUT 1968 Timeout for Flash set sector lock bit operation (in ms) 1969 1970- CFG_FLASH_UNLOCK_TOUT 1971 Timeout for Flash clear lock bits operation (in ms) 1972 1973- CFG_FLASH_PROTECTION 1974 If defined, hardware flash sectors protection is used 1975 instead of U-Boot software protection. 1976 1977- CFG_DIRECT_FLASH_TFTP: 1978 1979 Enable TFTP transfers directly to flash memory; 1980 without this option such a download has to be 1981 performed in two steps: (1) download to RAM, and (2) 1982 copy from RAM to flash. 1983 1984 The two-step approach is usually more reliable, since 1985 you can check if the download worked before you erase 1986 the flash, but in some situations (when sytem RAM is 1987 too limited to allow for a tempory copy of the 1988 downloaded image) this option may be very useful. 1989 1990- CFG_FLASH_CFI: 1991 Define if the flash driver uses extra elements in the 1992 common flash structure for storing flash geometry. 1993 1994- CFG_FLASH_CFI_DRIVER 1995 This option also enables the building of the cfi_flash driver 1996 in the drivers directory 1997 1998- CFG_FLASH_QUIET_TEST 1999 If this option is defined, the common CFI flash doesn't 2000 print it's warning upon not recognized FLASH banks. This 2001 is useful, if some of the configured banks are only 2002 optionally available. 2003 2004- CFG_RX_ETH_BUFFER: 2005 Defines the number of ethernet receive buffers. On some 2006 ethernet controllers it is recommended to set this value 2007 to 8 or even higher (EEPRO100 or 405 EMAC), since all 2008 buffers can be full shortly after enabling the interface 2009 on high ethernet traffic. 2010 Defaults to 4 if not defined. 2011 2012The following definitions that deal with the placement and management 2013of environment data (variable area); in general, we support the 2014following configurations: 2015 2016- CFG_ENV_IS_IN_FLASH: 2017 2018 Define this if the environment is in flash memory. 2019 2020 a) The environment occupies one whole flash sector, which is 2021 "embedded" in the text segment with the U-Boot code. This 2022 happens usually with "bottom boot sector" or "top boot 2023 sector" type flash chips, which have several smaller 2024 sectors at the start or the end. For instance, such a 2025 layout can have sector sizes of 8, 2x4, 16, Nx32 kB. In 2026 such a case you would place the environment in one of the 2027 4 kB sectors - with U-Boot code before and after it. With 2028 "top boot sector" type flash chips, you would put the 2029 environment in one of the last sectors, leaving a gap 2030 between U-Boot and the environment. 2031 2032 - CFG_ENV_OFFSET: 2033 2034 Offset of environment data (variable area) to the 2035 beginning of flash memory; for instance, with bottom boot 2036 type flash chips the second sector can be used: the offset 2037 for this sector is given here. 2038 2039 CFG_ENV_OFFSET is used relative to CFG_FLASH_BASE. 2040 2041 - CFG_ENV_ADDR: 2042 2043 This is just another way to specify the start address of 2044 the flash sector containing the environment (instead of 2045 CFG_ENV_OFFSET). 2046 2047 - CFG_ENV_SECT_SIZE: 2048 2049 Size of the sector containing the environment. 2050 2051 2052 b) Sometimes flash chips have few, equal sized, BIG sectors. 2053 In such a case you don't want to spend a whole sector for 2054 the environment. 2055 2056 - CFG_ENV_SIZE: 2057 2058 If you use this in combination with CFG_ENV_IS_IN_FLASH 2059 and CFG_ENV_SECT_SIZE, you can specify to use only a part 2060 of this flash sector for the environment. This saves 2061 memory for the RAM copy of the environment. 2062 2063 It may also save flash memory if you decide to use this 2064 when your environment is "embedded" within U-Boot code, 2065 since then the remainder of the flash sector could be used 2066 for U-Boot code. It should be pointed out that this is 2067 STRONGLY DISCOURAGED from a robustness point of view: 2068 updating the environment in flash makes it always 2069 necessary to erase the WHOLE sector. If something goes 2070 wrong before the contents has been restored from a copy in 2071 RAM, your target system will be dead. 2072 2073 - CFG_ENV_ADDR_REDUND 2074 CFG_ENV_SIZE_REDUND 2075 2076 These settings describe a second storage area used to hold 2077 a redundand copy of the environment data, so that there is 2078 a valid backup copy in case there is a power failure during 2079 a "saveenv" operation. 2080 2081BE CAREFUL! Any changes to the flash layout, and some changes to the 2082source code will make it necessary to adapt <board>/u-boot.lds* 2083accordingly! 2084 2085 2086- CFG_ENV_IS_IN_NVRAM: 2087 2088 Define this if you have some non-volatile memory device 2089 (NVRAM, battery buffered SRAM) which you want to use for the 2090 environment. 2091 2092 - CFG_ENV_ADDR: 2093 - CFG_ENV_SIZE: 2094 2095 These two #defines are used to determin the memory area you 2096 want to use for environment. It is assumed that this memory 2097 can just be read and written to, without any special 2098 provision. 2099 2100BE CAREFUL! The first access to the environment happens quite early 2101in U-Boot initalization (when we try to get the setting of for the 2102console baudrate). You *MUST* have mappend your NVRAM area then, or 2103U-Boot will hang. 2104 2105Please note that even with NVRAM we still use a copy of the 2106environment in RAM: we could work on NVRAM directly, but we want to 2107keep settings there always unmodified except somebody uses "saveenv" 2108to save the current settings. 2109 2110 2111- CFG_ENV_IS_IN_EEPROM: 2112 2113 Use this if you have an EEPROM or similar serial access 2114 device and a driver for it. 2115 2116 - CFG_ENV_OFFSET: 2117 - CFG_ENV_SIZE: 2118 2119 These two #defines specify the offset and size of the 2120 environment area within the total memory of your EEPROM. 2121 2122 - CFG_I2C_EEPROM_ADDR: 2123 If defined, specified the chip address of the EEPROM device. 2124 The default address is zero. 2125 2126 - CFG_EEPROM_PAGE_WRITE_BITS: 2127 If defined, the number of bits used to address bytes in a 2128 single page in the EEPROM device. A 64 byte page, for example 2129 would require six bits. 2130 2131 - CFG_EEPROM_PAGE_WRITE_DELAY_MS: 2132 If defined, the number of milliseconds to delay between 2133 page writes. The default is zero milliseconds. 2134 2135 - CFG_I2C_EEPROM_ADDR_LEN: 2136 The length in bytes of the EEPROM memory array address. Note 2137 that this is NOT the chip address length! 2138 2139 - CFG_I2C_EEPROM_ADDR_OVERFLOW: 2140 EEPROM chips that implement "address overflow" are ones 2141 like Catalyst 24WC04/08/16 which has 9/10/11 bits of 2142 address and the extra bits end up in the "chip address" bit 2143 slots. This makes a 24WC08 (1Kbyte) chip look like four 256 2144 byte chips. 2145 2146 Note that we consider the length of the address field to 2147 still be one byte because the extra address bits are hidden 2148 in the chip address. 2149 2150 - CFG_EEPROM_SIZE: 2151 The size in bytes of the EEPROM device. 2152 2153 2154- CFG_ENV_IS_IN_DATAFLASH: 2155 2156 Define this if you have a DataFlash memory device which you 2157 want to use for the environment. 2158 2159 - CFG_ENV_OFFSET: 2160 - CFG_ENV_ADDR: 2161 - CFG_ENV_SIZE: 2162 2163 These three #defines specify the offset and size of the 2164 environment area within the total memory of your DataFlash placed 2165 at the specified address. 2166 2167- CFG_ENV_IS_IN_NAND: 2168 2169 Define this if you have a NAND device which you want to use 2170 for the environment. 2171 2172 - CFG_ENV_OFFSET: 2173 - CFG_ENV_SIZE: 2174 2175 These two #defines specify the offset and size of the environment 2176 area within the first NAND device. 2177 2178 - CFG_ENV_OFFSET_REDUND 2179 2180 This setting describes a second storage area of CFG_ENV_SIZE 2181 size used to hold a redundant copy of the environment data, 2182 so that there is a valid backup copy in case there is a 2183 power failure during a "saveenv" operation. 2184 2185 Note: CFG_ENV_OFFSET and CFG_ENV_OFFSET_REDUND must be aligned 2186 to a block boundary, and CFG_ENV_SIZE must be a multiple of 2187 the NAND devices block size. 2188 2189- CFG_SPI_INIT_OFFSET 2190 2191 Defines offset to the initial SPI buffer area in DPRAM. The 2192 area is used at an early stage (ROM part) if the environment 2193 is configured to reside in the SPI EEPROM: We need a 520 byte 2194 scratch DPRAM area. It is used between the two initialization 2195 calls (spi_init_f() and spi_init_r()). A value of 0xB00 seems 2196 to be a good choice since it makes it far enough from the 2197 start of the data area as well as from the stack pointer. 2198 2199Please note that the environment is read-only until the monitor 2200has been relocated to RAM and a RAM copy of the environment has been 2201created; also, when using EEPROM you will have to use getenv_r() 2202until then to read environment variables. 2203 2204The environment is protected by a CRC32 checksum. Before the monitor 2205is relocated into RAM, as a result of a bad CRC you will be working 2206with the compiled-in default environment - *silently*!!! [This is 2207necessary, because the first environment variable we need is the 2208"baudrate" setting for the console - if we have a bad CRC, we don't 2209have any device yet where we could complain.] 2210 2211Note: once the monitor has been relocated, then it will complain if 2212the default environment is used; a new CRC is computed as soon as you 2213use the "saveenv" command to store a valid environment. 2214 2215- CFG_FAULT_ECHO_LINK_DOWN: 2216 Echo the inverted Ethernet link state to the fault LED. 2217 2218 Note: If this option is active, then CFG_FAULT_MII_ADDR 2219 also needs to be defined. 2220 2221- CFG_FAULT_MII_ADDR: 2222 MII address of the PHY to check for the Ethernet link state. 2223 2224- CFG_64BIT_VSPRINTF: 2225 Makes vsprintf (and all *printf functions) support printing 2226 of 64bit values by using the L quantifier 2227 2228- CFG_64BIT_STRTOUL: 2229 Adds simple_strtoull that returns a 64bit value 2230 2231Low Level (hardware related) configuration options: 2232--------------------------------------------------- 2233 2234- CFG_CACHELINE_SIZE: 2235 Cache Line Size of the CPU. 2236 2237- CFG_DEFAULT_IMMR: 2238 Default address of the IMMR after system reset. 2239 2240 Needed on some 8260 systems (MPC8260ADS, PQ2FADS-ZU, 2241 and RPXsuper) to be able to adjust the position of 2242 the IMMR register after a reset. 2243 2244- Floppy Disk Support: 2245 CFG_FDC_DRIVE_NUMBER 2246 2247 the default drive number (default value 0) 2248 2249 CFG_ISA_IO_STRIDE 2250 2251 defines the spacing between fdc chipset registers 2252 (default value 1) 2253 2254 CFG_ISA_IO_OFFSET 2255 2256 defines the offset of register from address. It 2257 depends on which part of the data bus is connected to 2258 the fdc chipset. (default value 0) 2259 2260 If CFG_ISA_IO_STRIDE CFG_ISA_IO_OFFSET and 2261 CFG_FDC_DRIVE_NUMBER are undefined, they take their 2262 default value. 2263 2264 if CFG_FDC_HW_INIT is defined, then the function 2265 fdc_hw_init() is called at the beginning of the FDC 2266 setup. fdc_hw_init() must be provided by the board 2267 source code. It is used to make hardware dependant 2268 initializations. 2269 2270- CFG_IMMR: Physical address of the Internal Memory. 2271 DO NOT CHANGE unless you know exactly what you're 2272 doing! (11-4) [MPC8xx/82xx systems only] 2273 2274- CFG_INIT_RAM_ADDR: 2275 2276 Start address of memory area that can be used for 2277 initial data and stack; please note that this must be 2278 writable memory that is working WITHOUT special 2279 initialization, i. e. you CANNOT use normal RAM which 2280 will become available only after programming the 2281 memory controller and running certain initialization 2282 sequences. 2283 2284 U-Boot uses the following memory types: 2285 - MPC8xx and MPC8260: IMMR (internal memory of the CPU) 2286 - MPC824X: data cache 2287 - PPC4xx: data cache 2288 2289- CFG_GBL_DATA_OFFSET: 2290 2291 Offset of the initial data structure in the memory 2292 area defined by CFG_INIT_RAM_ADDR. Usually 2293 CFG_GBL_DATA_OFFSET is chosen such that the initial 2294 data is located at the end of the available space 2295 (sometimes written as (CFG_INIT_RAM_END - 2296 CFG_INIT_DATA_SIZE), and the initial stack is just 2297 below that area (growing from (CFG_INIT_RAM_ADDR + 2298 CFG_GBL_DATA_OFFSET) downward. 2299 2300 Note: 2301 On the MPC824X (or other systems that use the data 2302 cache for initial memory) the address chosen for 2303 CFG_INIT_RAM_ADDR is basically arbitrary - it must 2304 point to an otherwise UNUSED address space between 2305 the top of RAM and the start of the PCI space. 2306 2307- CFG_SIUMCR: SIU Module Configuration (11-6) 2308 2309- CFG_SYPCR: System Protection Control (11-9) 2310 2311- CFG_TBSCR: Time Base Status and Control (11-26) 2312 2313- CFG_PISCR: Periodic Interrupt Status and Control (11-31) 2314 2315- CFG_PLPRCR: PLL, Low-Power, and Reset Control Register (15-30) 2316 2317- CFG_SCCR: System Clock and reset Control Register (15-27) 2318 2319- CFG_OR_TIMING_SDRAM: 2320 SDRAM timing 2321 2322- CFG_MAMR_PTA: 2323 periodic timer for refresh 2324 2325- CFG_DER: Debug Event Register (37-47) 2326 2327- FLASH_BASE0_PRELIM, FLASH_BASE1_PRELIM, CFG_REMAP_OR_AM, 2328 CFG_PRELIM_OR_AM, CFG_OR_TIMING_FLASH, CFG_OR0_REMAP, 2329 CFG_OR0_PRELIM, CFG_BR0_PRELIM, CFG_OR1_REMAP, CFG_OR1_PRELIM, 2330 CFG_BR1_PRELIM: 2331 Memory Controller Definitions: BR0/1 and OR0/1 (FLASH) 2332 2333- SDRAM_BASE2_PRELIM, SDRAM_BASE3_PRELIM, SDRAM_MAX_SIZE, 2334 CFG_OR_TIMING_SDRAM, CFG_OR2_PRELIM, CFG_BR2_PRELIM, 2335 CFG_OR3_PRELIM, CFG_BR3_PRELIM: 2336 Memory Controller Definitions: BR2/3 and OR2/3 (SDRAM) 2337 2338- CFG_MAMR_PTA, CFG_MPTPR_2BK_4K, CFG_MPTPR_1BK_4K, CFG_MPTPR_2BK_8K, 2339 CFG_MPTPR_1BK_8K, CFG_MAMR_8COL, CFG_MAMR_9COL: 2340 Machine Mode Register and Memory Periodic Timer 2341 Prescaler definitions (SDRAM timing) 2342 2343- CFG_I2C_UCODE_PATCH, CFG_I2C_DPMEM_OFFSET [0x1FC0]: 2344 enable I2C microcode relocation patch (MPC8xx); 2345 define relocation offset in DPRAM [DSP2] 2346 2347- CFG_SMC_UCODE_PATCH, CFG_SMC_DPMEM_OFFSET [0x1FC0]: 2348 enable SMC microcode relocation patch (MPC8xx); 2349 define relocation offset in DPRAM [SMC1] 2350 2351- CFG_SPI_UCODE_PATCH, CFG_SPI_DPMEM_OFFSET [0x1FC0]: 2352 enable SPI microcode relocation patch (MPC8xx); 2353 define relocation offset in DPRAM [SCC4] 2354 2355- CFG_USE_OSCCLK: 2356 Use OSCM clock mode on MBX8xx board. Be careful, 2357 wrong setting might damage your board. Read 2358 doc/README.MBX before setting this variable! 2359 2360- CFG_CPM_POST_WORD_ADDR: (MPC8xx, MPC8260 only) 2361 Offset of the bootmode word in DPRAM used by post 2362 (Power On Self Tests). This definition overrides 2363 #define'd default value in commproc.h resp. 2364 cpm_8260.h. 2365 2366- CFG_PCI_SLV_MEM_LOCAL, CFG_PCI_SLV_MEM_BUS, CFG_PICMR0_MASK_ATTRIB, 2367 CFG_PCI_MSTR0_LOCAL, CFG_PCIMSK0_MASK, CFG_PCI_MSTR1_LOCAL, 2368 CFG_PCIMSK1_MASK, CFG_PCI_MSTR_MEM_LOCAL, CFG_PCI_MSTR_MEM_BUS, 2369 CFG_CPU_PCI_MEM_START, CFG_PCI_MSTR_MEM_SIZE, CFG_POCMR0_MASK_ATTRIB, 2370 CFG_PCI_MSTR_MEMIO_LOCAL, CFG_PCI_MSTR_MEMIO_BUS, CPU_PCI_MEMIO_START, 2371 CFG_PCI_MSTR_MEMIO_SIZE, CFG_POCMR1_MASK_ATTRIB, CFG_PCI_MSTR_IO_LOCAL, 2372 CFG_PCI_MSTR_IO_BUS, CFG_CPU_PCI_IO_START, CFG_PCI_MSTR_IO_SIZE, 2373 CFG_POCMR2_MASK_ATTRIB: (MPC826x only) 2374 Overrides the default PCI memory map in cpu/mpc8260/pci.c if set. 2375 2376- CONFIG_SPD_EEPROM 2377 Get DDR timing information from an I2C EEPROM. Common with pluggable 2378 memory modules such as SODIMMs 2379 SPD_EEPROM_ADDRESS 2380 I2C address of the SPD EEPROM 2381 2382- CFG_SPD_BUS_NUM 2383 If SPD EEPROM is on an I2C bus other than the first one, specify here. 2384 Note that the value must resolve to something your driver can deal with. 2385 2386- CFG_83XX_DDR_USES_CS0 2387 Only for 83xx systems. If specified, then DDR should be configured 2388 using CS0 and CS1 instead of CS2 and CS3. 2389 2390- CFG_83XX_DDR_USES_CS0 2391 Only for 83xx systems. If specified, then DDR should be configured 2392 using CS0 and CS1 instead of CS2 and CS3. 2393 2394- CONFIG_ETHER_ON_FEC[12] 2395 Define to enable FEC[12] on a 8xx series processor. 2396 2397- CONFIG_FEC[12]_PHY 2398 Define to the hardcoded PHY address which corresponds 2399 to the given FEC; i. e. 2400 #define CONFIG_FEC1_PHY 4 2401 means that the PHY with address 4 is connected to FEC1 2402 2403 When set to -1, means to probe for first available. 2404 2405- CONFIG_FEC[12]_PHY_NORXERR 2406 The PHY does not have a RXERR line (RMII only). 2407 (so program the FEC to ignore it). 2408 2409- CONFIG_RMII 2410 Enable RMII mode for all FECs. 2411 Note that this is a global option, we can't 2412 have one FEC in standard MII mode and another in RMII mode. 2413 2414- CONFIG_CRC32_VERIFY 2415 Add a verify option to the crc32 command. 2416 The syntax is: 2417 2418 => crc32 -v <address> <count> <crc32> 2419 2420 Where address/count indicate a memory area 2421 and crc32 is the correct crc32 which the 2422 area should have. 2423 2424- CONFIG_LOOPW 2425 Add the "loopw" memory command. This only takes effect if 2426 the memory commands are activated globally (CONFIG_CMD_MEM). 2427 2428- CONFIG_MX_CYCLIC 2429 Add the "mdc" and "mwc" memory commands. These are cyclic 2430 "md/mw" commands. 2431 Examples: 2432 2433 => mdc.b 10 4 500 2434 This command will print 4 bytes (10,11,12,13) each 500 ms. 2435 2436 => mwc.l 100 12345678 10 2437 This command will write 12345678 to address 100 all 10 ms. 2438 2439 This only takes effect if the memory commands are activated 2440 globally (CONFIG_CMD_MEM). 2441 2442- CONFIG_SKIP_LOWLEVEL_INIT 2443- CONFIG_SKIP_RELOCATE_UBOOT 2444 2445 [ARM only] If these variables are defined, then 2446 certain low level initializations (like setting up 2447 the memory controller) are omitted and/or U-Boot does 2448 not relocate itself into RAM. 2449 Normally these variables MUST NOT be defined. The 2450 only exception is when U-Boot is loaded (to RAM) by 2451 some other boot loader or by a debugger which 2452 performs these intializations itself. 2453 2454 2455Building the Software: 2456====================== 2457 2458Building U-Boot has been tested in native PPC environments (on a 2459PowerBook G3 running LinuxPPC 2000) and in cross environments 2460(running RedHat 6.x and 7.x Linux on x86, Solaris 2.6 on a SPARC, and 2461NetBSD 1.5 on x86). 2462 2463If you are not using a native PPC environment, it is assumed that you 2464have the GNU cross compiling tools available in your path and named 2465with a prefix of "powerpc-linux-". If this is not the case, (e.g. if 2466you are using Monta Vista's Hard Hat Linux CDK 1.2) you must change 2467the definition of CROSS_COMPILE in Makefile. For HHL on a 4xx CPU, 2468change it to: 2469 2470 CROSS_COMPILE = ppc_4xx- 2471 2472 2473U-Boot is intended to be simple to build. After installing the 2474sources you must configure U-Boot for one specific board type. This 2475is done by typing: 2476 2477 make NAME_config 2478 2479where "NAME_config" is the name of one of the existing 2480configurations; see the main Makefile for supported names. 2481 2482Note: for some board special configuration names may exist; check if 2483 additional information is available from the board vendor; for 2484 instance, the TQM823L systems are available without (standard) 2485 or with LCD support. You can select such additional "features" 2486 when chosing the configuration, i. e. 2487 2488 make TQM823L_config 2489 - will configure for a plain TQM823L, i. e. no LCD support 2490 2491 make TQM823L_LCD_config 2492 - will configure for a TQM823L with U-Boot console on LCD 2493 2494 etc. 2495 2496 2497Finally, type "make all", and you should get some working U-Boot 2498images ready for download to / installation on your system: 2499 2500- "u-boot.bin" is a raw binary image 2501- "u-boot" is an image in ELF binary format 2502- "u-boot.srec" is in Motorola S-Record format 2503 2504By default the build is performed locally and the objects are saved 2505in the source directory. One of the two methods can be used to change 2506this behavior and build U-Boot to some external directory: 2507 25081. Add O= to the make command line invocations: 2509 2510 make O=/tmp/build distclean 2511 make O=/tmp/build NAME_config 2512 make O=/tmp/build all 2513 25142. Set environment variable BUILD_DIR to point to the desired location: 2515 2516 export BUILD_DIR=/tmp/build 2517 make distclean 2518 make NAME_config 2519 make all 2520 2521Note that the command line "O=" setting overrides the BUILD_DIR environment 2522variable. 2523 2524 2525Please be aware that the Makefiles assume you are using GNU make, so 2526for instance on NetBSD you might need to use "gmake" instead of 2527native "make". 2528 2529 2530If the system board that you have is not listed, then you will need 2531to port U-Boot to your hardware platform. To do this, follow these 2532steps: 2533 25341. Add a new configuration option for your board to the toplevel 2535 "Makefile" and to the "MAKEALL" script, using the existing 2536 entries as examples. Note that here and at many other places 2537 boards and other names are listed in alphabetical sort order. Please 2538 keep this order. 25392. Create a new directory to hold your board specific code. Add any 2540 files you need. In your board directory, you will need at least 2541 the "Makefile", a "<board>.c", "flash.c" and "u-boot.lds". 25423. Create a new configuration file "include/configs/<board>.h" for 2543 your board 25443. If you're porting U-Boot to a new CPU, then also create a new 2545 directory to hold your CPU specific code. Add any files you need. 25464. Run "make <board>_config" with your new name. 25475. Type "make", and you should get a working "u-boot.srec" file 2548 to be installed on your target system. 25496. Debug and solve any problems that might arise. 2550 [Of course, this last step is much harder than it sounds.] 2551 2552 2553Testing of U-Boot Modifications, Ports to New Hardware, etc.: 2554============================================================== 2555 2556If you have modified U-Boot sources (for instance added a new board 2557or support for new devices, a new CPU, etc.) you are expected to 2558provide feedback to the other developers. The feedback normally takes 2559the form of a "patch", i. e. a context diff against a certain (latest 2560official or latest in CVS) version of U-Boot sources. 2561 2562But before you submit such a patch, please verify that your modifi- 2563cation did not break existing code. At least make sure that *ALL* of 2564the supported boards compile WITHOUT ANY compiler warnings. To do so, 2565just run the "MAKEALL" script, which will configure and build U-Boot 2566for ALL supported system. Be warned, this will take a while. You can 2567select which (cross) compiler to use by passing a `CROSS_COMPILE' 2568environment variable to the script, i. e. to use the cross tools from 2569MontaVista's Hard Hat Linux you can type 2570 2571 CROSS_COMPILE=ppc_8xx- MAKEALL 2572 2573or to build on a native PowerPC system you can type 2574 2575 CROSS_COMPILE=' ' MAKEALL 2576 2577When using the MAKEALL script, the default behaviour is to build U-Boot 2578in the source directory. This location can be changed by setting the 2579BUILD_DIR environment variable. Also, for each target built, the MAKEALL 2580script saves two log files (<target>.ERR and <target>.MAKEALL) in the 2581<source dir>/LOG directory. This default location can be changed by 2582setting the MAKEALL_LOGDIR environment variable. For example: 2583 2584 export BUILD_DIR=/tmp/build 2585 export MAKEALL_LOGDIR=/tmp/log 2586 CROSS_COMPILE=ppc_8xx- MAKEALL 2587 2588With the above settings build objects are saved in the /tmp/build, log 2589files are saved in the /tmp/log and the source tree remains clean during 2590the whole build process. 2591 2592 2593See also "U-Boot Porting Guide" below. 2594 2595 2596Monitor Commands - Overview: 2597============================ 2598 2599go - start application at address 'addr' 2600run - run commands in an environment variable 2601bootm - boot application image from memory 2602bootp - boot image via network using BootP/TFTP protocol 2603tftpboot- boot image via network using TFTP protocol 2604 and env variables "ipaddr" and "serverip" 2605 (and eventually "gatewayip") 2606rarpboot- boot image via network using RARP/TFTP protocol 2607diskboot- boot from IDE devicebootd - boot default, i.e., run 'bootcmd' 2608loads - load S-Record file over serial line 2609loadb - load binary file over serial line (kermit mode) 2610md - memory display 2611mm - memory modify (auto-incrementing) 2612nm - memory modify (constant address) 2613mw - memory write (fill) 2614cp - memory copy 2615cmp - memory compare 2616crc32 - checksum calculation 2617imd - i2c memory display 2618imm - i2c memory modify (auto-incrementing) 2619inm - i2c memory modify (constant address) 2620imw - i2c memory write (fill) 2621icrc32 - i2c checksum calculation 2622iprobe - probe to discover valid I2C chip addresses 2623iloop - infinite loop on address range 2624isdram - print SDRAM configuration information 2625sspi - SPI utility commands 2626base - print or set address offset 2627printenv- print environment variables 2628setenv - set environment variables 2629saveenv - save environment variables to persistent storage 2630protect - enable or disable FLASH write protection 2631erase - erase FLASH memory 2632flinfo - print FLASH memory information 2633bdinfo - print Board Info structure 2634iminfo - print header information for application image 2635coninfo - print console devices and informations 2636ide - IDE sub-system 2637loop - infinite loop on address range 2638loopw - infinite write loop on address range 2639mtest - simple RAM test 2640icache - enable or disable instruction cache 2641dcache - enable or disable data cache 2642reset - Perform RESET of the CPU 2643echo - echo args to console 2644version - print monitor version 2645help - print online help 2646? - alias for 'help' 2647 2648 2649Monitor Commands - Detailed Description: 2650======================================== 2651 2652TODO. 2653 2654For now: just type "help <command>". 2655 2656 2657Environment Variables: 2658====================== 2659 2660U-Boot supports user configuration using Environment Variables which 2661can be made persistent by saving to Flash memory. 2662 2663Environment Variables are set using "setenv", printed using 2664"printenv", and saved to Flash using "saveenv". Using "setenv" 2665without a value can be used to delete a variable from the 2666environment. As long as you don't save the environment you are 2667working with an in-memory copy. In case the Flash area containing the 2668environment is erased by accident, a default environment is provided. 2669 2670Some configuration options can be set using Environment Variables: 2671 2672 baudrate - see CONFIG_BAUDRATE 2673 2674 bootdelay - see CONFIG_BOOTDELAY 2675 2676 bootcmd - see CONFIG_BOOTCOMMAND 2677 2678 bootargs - Boot arguments when booting an RTOS image 2679 2680 bootfile - Name of the image to load with TFTP 2681 2682 autoload - if set to "no" (any string beginning with 'n'), 2683 "bootp" will just load perform a lookup of the 2684 configuration from the BOOTP server, but not try to 2685 load any image using TFTP 2686 2687 autoscript - if set to "yes" commands like "loadb", "loady", 2688 "bootp", "tftpb", "rarpboot" and "nfs" will attempt 2689 to automatically run script images (by internally 2690 calling "autoscript"). 2691 2692 autoscript_uname - if script image is in a format (FIT) this 2693 variable is used to get script subimage unit name. 2694 2695 autostart - if set to "yes", an image loaded using the "bootp", 2696 "rarpboot", "tftpboot" or "diskboot" commands will 2697 be automatically started (by internally calling 2698 "bootm") 2699 2700 If set to "no", a standalone image passed to the 2701 "bootm" command will be copied to the load address 2702 (and eventually uncompressed), but NOT be started. 2703 This can be used to load and uncompress arbitrary 2704 data. 2705 2706 i2cfast - (PPC405GP|PPC405EP only) 2707 if set to 'y' configures Linux I2C driver for fast 2708 mode (400kHZ). This environment variable is used in 2709 initialization code. So, for changes to be effective 2710 it must be saved and board must be reset. 2711 2712 initrd_high - restrict positioning of initrd images: 2713 If this variable is not set, initrd images will be 2714 copied to the highest possible address in RAM; this 2715 is usually what you want since it allows for 2716 maximum initrd size. If for some reason you want to 2717 make sure that the initrd image is loaded below the 2718 CFG_BOOTMAPSZ limit, you can set this environment 2719 variable to a value of "no" or "off" or "0". 2720 Alternatively, you can set it to a maximum upper 2721 address to use (U-Boot will still check that it 2722 does not overwrite the U-Boot stack and data). 2723 2724 For instance, when you have a system with 16 MB 2725 RAM, and want to reserve 4 MB from use by Linux, 2726 you can do this by adding "mem=12M" to the value of 2727 the "bootargs" variable. However, now you must make 2728 sure that the initrd image is placed in the first 2729 12 MB as well - this can be done with 2730 2731 setenv initrd_high 00c00000 2732 2733 If you set initrd_high to 0xFFFFFFFF, this is an 2734 indication to U-Boot that all addresses are legal 2735 for the Linux kernel, including addresses in flash 2736 memory. In this case U-Boot will NOT COPY the 2737 ramdisk at all. This may be useful to reduce the 2738 boot time on your system, but requires that this 2739 feature is supported by your Linux kernel. 2740 2741 ipaddr - IP address; needed for tftpboot command 2742 2743 loadaddr - Default load address for commands like "bootp", 2744 "rarpboot", "tftpboot", "loadb" or "diskboot" 2745 2746 loads_echo - see CONFIG_LOADS_ECHO 2747 2748 serverip - TFTP server IP address; needed for tftpboot command 2749 2750 bootretry - see CONFIG_BOOT_RETRY_TIME 2751 2752 bootdelaykey - see CONFIG_AUTOBOOT_DELAY_STR 2753 2754 bootstopkey - see CONFIG_AUTOBOOT_STOP_STR 2755 2756 ethprime - When CONFIG_NET_MULTI is enabled controls which 2757 interface is used first. 2758 2759 ethact - When CONFIG_NET_MULTI is enabled controls which 2760 interface is currently active. For example you 2761 can do the following 2762 2763 => setenv ethact FEC ETHERNET 2764 => ping 192.168.0.1 # traffic sent on FEC ETHERNET 2765 => setenv ethact SCC ETHERNET 2766 => ping 10.0.0.1 # traffic sent on SCC ETHERNET 2767 2768 ethrotate - When set to "no" U-Boot does not go through all 2769 available network interfaces. 2770 It just stays at the currently selected interface. 2771 2772 netretry - When set to "no" each network operation will 2773 either succeed or fail without retrying. 2774 When set to "once" the network operation will 2775 fail when all the available network interfaces 2776 are tried once without success. 2777 Useful on scripts which control the retry operation 2778 themselves. 2779 2780 npe_ucode - see CONFIG_IXP4XX_NPE_EXT_UCOD 2781 if set load address for the npe microcode 2782 2783 tftpsrcport - If this is set, the value is used for TFTP's 2784 UDP source port. 2785 2786 tftpdstport - If this is set, the value is used for TFTP's UDP 2787 destination port instead of the Well Know Port 69. 2788 2789 vlan - When set to a value < 4095 the traffic over 2790 ethernet is encapsulated/received over 802.1q 2791 VLAN tagged frames. 2792 2793The following environment variables may be used and automatically 2794updated by the network boot commands ("bootp" and "rarpboot"), 2795depending the information provided by your boot server: 2796 2797 bootfile - see above 2798 dnsip - IP address of your Domain Name Server 2799 dnsip2 - IP address of your secondary Domain Name Server 2800 gatewayip - IP address of the Gateway (Router) to use 2801 hostname - Target hostname 2802 ipaddr - see above 2803 netmask - Subnet Mask 2804 rootpath - Pathname of the root filesystem on the NFS server 2805 serverip - see above 2806 2807 2808There are two special Environment Variables: 2809 2810 serial# - contains hardware identification information such 2811 as type string and/or serial number 2812 ethaddr - Ethernet address 2813 2814These variables can be set only once (usually during manufacturing of 2815the board). U-Boot refuses to delete or overwrite these variables 2816once they have been set once. 2817 2818 2819Further special Environment Variables: 2820 2821 ver - Contains the U-Boot version string as printed 2822 with the "version" command. This variable is 2823 readonly (see CONFIG_VERSION_VARIABLE). 2824 2825 2826Please note that changes to some configuration parameters may take 2827only effect after the next boot (yes, that's just like Windoze :-). 2828 2829 2830Command Line Parsing: 2831===================== 2832 2833There are two different command line parsers available with U-Boot: 2834the old "simple" one, and the much more powerful "hush" shell: 2835 2836Old, simple command line parser: 2837-------------------------------- 2838 2839- supports environment variables (through setenv / saveenv commands) 2840- several commands on one line, separated by ';' 2841- variable substitution using "... ${name} ..." syntax 2842- special characters ('$', ';') can be escaped by prefixing with '\', 2843 for example: 2844 setenv bootcmd bootm \${address} 2845- You can also escape text by enclosing in single apostrophes, for example: 2846 setenv addip 'setenv bootargs $bootargs ip=$ipaddr:$serverip:$gatewayip:$netmask:$hostname::off' 2847 2848Hush shell: 2849----------- 2850 2851- similar to Bourne shell, with control structures like 2852 if...then...else...fi, for...do...done; while...do...done, 2853 until...do...done, ... 2854- supports environment ("global") variables (through setenv / saveenv 2855 commands) and local shell variables (through standard shell syntax 2856 "name=value"); only environment variables can be used with "run" 2857 command 2858 2859General rules: 2860-------------- 2861 2862(1) If a command line (or an environment variable executed by a "run" 2863 command) contains several commands separated by semicolon, and 2864 one of these commands fails, then the remaining commands will be 2865 executed anyway. 2866 2867(2) If you execute several variables with one call to run (i. e. 2868 calling run with a list af variables as arguments), any failing 2869 command will cause "run" to terminate, i. e. the remaining 2870 variables are not executed. 2871 2872Note for Redundant Ethernet Interfaces: 2873======================================= 2874 2875Some boards come with redundant ethernet interfaces; U-Boot supports 2876such configurations and is capable of automatic selection of a 2877"working" interface when needed. MAC assignment works as follows: 2878 2879Network interfaces are numbered eth0, eth1, eth2, ... Corresponding 2880MAC addresses can be stored in the environment as "ethaddr" (=>eth0), 2881"eth1addr" (=>eth1), "eth2addr", ... 2882 2883If the network interface stores some valid MAC address (for instance 2884in SROM), this is used as default address if there is NO correspon- 2885ding setting in the environment; if the corresponding environment 2886variable is set, this overrides the settings in the card; that means: 2887 2888o If the SROM has a valid MAC address, and there is no address in the 2889 environment, the SROM's address is used. 2890 2891o If there is no valid address in the SROM, and a definition in the 2892 environment exists, then the value from the environment variable is 2893 used. 2894 2895o If both the SROM and the environment contain a MAC address, and 2896 both addresses are the same, this MAC address is used. 2897 2898o If both the SROM and the environment contain a MAC address, and the 2899 addresses differ, the value from the environment is used and a 2900 warning is printed. 2901 2902o If neither SROM nor the environment contain a MAC address, an error 2903 is raised. 2904 2905 2906Image Formats: 2907============== 2908 2909U-Boot is capable of booting (and performing other auxiliary operations on) 2910images in two formats: 2911 2912New uImage format (FIT) 2913----------------------- 2914 2915Flexible and powerful format based on Flattened Image Tree -- FIT (similar 2916to Flattened Device Tree). It allows the use of images with multiple 2917components (several kernels, ramdisks, etc.), with contents protected by 2918SHA1, MD5 or CRC32. More details are found in the doc/uImage.FIT directory. 2919 2920 2921Old uImage format 2922----------------- 2923 2924Old image format is based on binary files which can be basically anything, 2925preceded by a special header; see the definitions in include/image.h for 2926details; basically, the header defines the following image properties: 2927 2928* Target Operating System (Provisions for OpenBSD, NetBSD, FreeBSD, 2929 4.4BSD, Linux, SVR4, Esix, Solaris, Irix, SCO, Dell, NCR, VxWorks, 2930 LynxOS, pSOS, QNX, RTEMS, ARTOS; 2931 Currently supported: Linux, NetBSD, VxWorks, QNX, RTEMS, ARTOS, LynxOS). 2932* Target CPU Architecture (Provisions for Alpha, ARM, AVR32, Intel x86, 2933 IA64, MIPS, NIOS, PowerPC, IBM S390, SuperH, Sparc, Sparc 64 Bit; 2934 Currently supported: ARM, AVR32, Intel x86, MIPS, NIOS, PowerPC). 2935* Compression Type (uncompressed, gzip, bzip2) 2936* Load Address 2937* Entry Point 2938* Image Name 2939* Image Timestamp 2940 2941The header is marked by a special Magic Number, and both the header 2942and the data portions of the image are secured against corruption by 2943CRC32 checksums. 2944 2945 2946Linux Support: 2947============== 2948 2949Although U-Boot should support any OS or standalone application 2950easily, the main focus has always been on Linux during the design of 2951U-Boot. 2952 2953U-Boot includes many features that so far have been part of some 2954special "boot loader" code within the Linux kernel. Also, any 2955"initrd" images to be used are no longer part of one big Linux image; 2956instead, kernel and "initrd" are separate images. This implementation 2957serves several purposes: 2958 2959- the same features can be used for other OS or standalone 2960 applications (for instance: using compressed images to reduce the 2961 Flash memory footprint) 2962 2963- it becomes much easier to port new Linux kernel versions because 2964 lots of low-level, hardware dependent stuff are done by U-Boot 2965 2966- the same Linux kernel image can now be used with different "initrd" 2967 images; of course this also means that different kernel images can 2968 be run with the same "initrd". This makes testing easier (you don't 2969 have to build a new "zImage.initrd" Linux image when you just 2970 change a file in your "initrd"). Also, a field-upgrade of the 2971 software is easier now. 2972 2973 2974Linux HOWTO: 2975============ 2976 2977Porting Linux to U-Boot based systems: 2978--------------------------------------- 2979 2980U-Boot cannot save you from doing all the necessary modifications to 2981configure the Linux device drivers for use with your target hardware 2982(no, we don't intend to provide a full virtual machine interface to 2983Linux :-). 2984 2985But now you can ignore ALL boot loader code (in arch/ppc/mbxboot). 2986 2987Just make sure your machine specific header file (for instance 2988include/asm-ppc/tqm8xx.h) includes the same definition of the Board 2989Information structure as we define in include/u-boot.h, and make 2990sure that your definition of IMAP_ADDR uses the same value as your 2991U-Boot configuration in CFG_IMMR. 2992 2993 2994Configuring the Linux kernel: 2995----------------------------- 2996 2997No specific requirements for U-Boot. Make sure you have some root 2998device (initial ramdisk, NFS) for your target system. 2999 3000 3001Building a Linux Image: 3002----------------------- 3003 3004With U-Boot, "normal" build targets like "zImage" or "bzImage" are 3005not used. If you use recent kernel source, a new build target 3006"uImage" will exist which automatically builds an image usable by 3007U-Boot. Most older kernels also have support for a "pImage" target, 3008which was introduced for our predecessor project PPCBoot and uses a 3009100% compatible format. 3010 3011Example: 3012 3013 make TQM850L_config 3014 make oldconfig 3015 make dep 3016 make uImage 3017 3018The "uImage" build target uses a special tool (in 'tools/mkimage') to 3019encapsulate a compressed Linux kernel image with header information, 3020CRC32 checksum etc. for use with U-Boot. This is what we are doing: 3021 3022* build a standard "vmlinux" kernel image (in ELF binary format): 3023 3024* convert the kernel into a raw binary image: 3025 3026 ${CROSS_COMPILE}-objcopy -O binary \ 3027 -R .note -R .comment \ 3028 -S vmlinux linux.bin 3029 3030* compress the binary image: 3031 3032 gzip -9 linux.bin 3033 3034* package compressed binary image for U-Boot: 3035 3036 mkimage -A ppc -O linux -T kernel -C gzip \ 3037 -a 0 -e 0 -n "Linux Kernel Image" \ 3038 -d linux.bin.gz uImage 3039 3040 3041The "mkimage" tool can also be used to create ramdisk images for use 3042with U-Boot, either separated from the Linux kernel image, or 3043combined into one file. "mkimage" encapsulates the images with a 64 3044byte header containing information about target architecture, 3045operating system, image type, compression method, entry points, time 3046stamp, CRC32 checksums, etc. 3047 3048"mkimage" can be called in two ways: to verify existing images and 3049print the header information, or to build new images. 3050 3051In the first form (with "-l" option) mkimage lists the information 3052contained in the header of an existing U-Boot image; this includes 3053checksum verification: 3054 3055 tools/mkimage -l image 3056 -l ==> list image header information 3057 3058The second form (with "-d" option) is used to build a U-Boot image 3059from a "data file" which is used as image payload: 3060 3061 tools/mkimage -A arch -O os -T type -C comp -a addr -e ep \ 3062 -n name -d data_file image 3063 -A ==> set architecture to 'arch' 3064 -O ==> set operating system to 'os' 3065 -T ==> set image type to 'type' 3066 -C ==> set compression type 'comp' 3067 -a ==> set load address to 'addr' (hex) 3068 -e ==> set entry point to 'ep' (hex) 3069 -n ==> set image name to 'name' 3070 -d ==> use image data from 'datafile' 3071 3072Right now, all Linux kernels for PowerPC systems use the same load 3073address (0x00000000), but the entry point address depends on the 3074kernel version: 3075 3076- 2.2.x kernels have the entry point at 0x0000000C, 3077- 2.3.x and later kernels have the entry point at 0x00000000. 3078 3079So a typical call to build a U-Boot image would read: 3080 3081 -> tools/mkimage -n '2.4.4 kernel for TQM850L' \ 3082 > -A ppc -O linux -T kernel -C gzip -a 0 -e 0 \ 3083 > -d /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/ppc/coffboot/vmlinux.gz \ 3084 > examples/uImage.TQM850L 3085 Image Name: 2.4.4 kernel for TQM850L 3086 Created: Wed Jul 19 02:34:59 2000 3087 Image Type: PowerPC Linux Kernel Image (gzip compressed) 3088 Data Size: 335725 Bytes = 327.86 kB = 0.32 MB 3089 Load Address: 0x00000000 3090 Entry Point: 0x00000000 3091 3092To verify the contents of the image (or check for corruption): 3093 3094 -> tools/mkimage -l examples/uImage.TQM850L 3095 Image Name: 2.4.4 kernel for TQM850L 3096 Created: Wed Jul 19 02:34:59 2000 3097 Image Type: PowerPC Linux Kernel Image (gzip compressed) 3098 Data Size: 335725 Bytes = 327.86 kB = 0.32 MB 3099 Load Address: 0x00000000 3100 Entry Point: 0x00000000 3101 3102NOTE: for embedded systems where boot time is critical you can trade 3103speed for memory and install an UNCOMPRESSED image instead: this 3104needs more space in Flash, but boots much faster since it does not 3105need to be uncompressed: 3106 3107 -> gunzip /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/ppc/coffboot/vmlinux.gz 3108 -> tools/mkimage -n '2.4.4 kernel for TQM850L' \ 3109 > -A ppc -O linux -T kernel -C none -a 0 -e 0 \ 3110 > -d /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/ppc/coffboot/vmlinux \ 3111 > examples/uImage.TQM850L-uncompressed 3112 Image Name: 2.4.4 kernel for TQM850L 3113 Created: Wed Jul 19 02:34:59 2000 3114 Image Type: PowerPC Linux Kernel Image (uncompressed) 3115 Data Size: 792160 Bytes = 773.59 kB = 0.76 MB 3116 Load Address: 0x00000000 3117 Entry Point: 0x00000000 3118 3119 3120Similar you can build U-Boot images from a 'ramdisk.image.gz' file 3121when your kernel is intended to use an initial ramdisk: 3122 3123 -> tools/mkimage -n 'Simple Ramdisk Image' \ 3124 > -A ppc -O linux -T ramdisk -C gzip \ 3125 > -d /LinuxPPC/images/SIMPLE-ramdisk.image.gz examples/simple-initrd 3126 Image Name: Simple Ramdisk Image 3127 Created: Wed Jan 12 14:01:50 2000 3128 Image Type: PowerPC Linux RAMDisk Image (gzip compressed) 3129 Data Size: 566530 Bytes = 553.25 kB = 0.54 MB 3130 Load Address: 0x00000000 3131 Entry Point: 0x00000000 3132 3133 3134Installing a Linux Image: 3135------------------------- 3136 3137To downloading a U-Boot image over the serial (console) interface, 3138you must convert the image to S-Record format: 3139 3140 objcopy -I binary -O srec examples/image examples/image.srec 3141 3142The 'objcopy' does not understand the information in the U-Boot 3143image header, so the resulting S-Record file will be relative to 3144address 0x00000000. To load it to a given address, you need to 3145specify the target address as 'offset' parameter with the 'loads' 3146command. 3147 3148Example: install the image to address 0x40100000 (which on the 3149TQM8xxL is in the first Flash bank): 3150 3151 => erase 40100000 401FFFFF 3152 3153 .......... done 3154 Erased 8 sectors 3155 3156 => loads 40100000 3157 ## Ready for S-Record download ... 3158 ~>examples/image.srec 3159 1 2 3 4 5 6 7 8 9 10 11 12 13 ... 3160 ... 3161 15989 15990 15991 15992 3162 [file transfer complete] 3163 [connected] 3164 ## Start Addr = 0x00000000 3165 3166 3167You can check the success of the download using the 'iminfo' command; 3168this includes a checksum verification so you can be sure no data 3169corruption happened: 3170 3171 => imi 40100000 3172 3173 ## Checking Image at 40100000 ... 3174 Image Name: 2.2.13 for initrd on TQM850L 3175 Image Type: PowerPC Linux Kernel Image (gzip compressed) 3176 Data Size: 335725 Bytes = 327 kB = 0 MB 3177 Load Address: 00000000 3178 Entry Point: 0000000c 3179 Verifying Checksum ... OK 3180 3181 3182Boot Linux: 3183----------- 3184 3185The "bootm" command is used to boot an application that is stored in 3186memory (RAM or Flash). In case of a Linux kernel image, the contents 3187of the "bootargs" environment variable is passed to the kernel as 3188parameters. You can check and modify this variable using the 3189"printenv" and "setenv" commands: 3190 3191 3192 => printenv bootargs 3193 bootargs=root=/dev/ram 3194 3195 => setenv bootargs root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2 3196 3197 => printenv bootargs 3198 bootargs=root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2 3199 3200 => bootm 40020000 3201 ## Booting Linux kernel at 40020000 ... 3202 Image Name: 2.2.13 for NFS on TQM850L 3203 Image Type: PowerPC Linux Kernel Image (gzip compressed) 3204 Data Size: 381681 Bytes = 372 kB = 0 MB 3205 Load Address: 00000000 3206 Entry Point: 0000000c 3207 Verifying Checksum ... OK 3208 Uncompressing Kernel Image ... OK 3209 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 3210 Boot arguments: root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2 3211 time_init: decrementer frequency = 187500000/60 3212 Calibrating delay loop... 49.77 BogoMIPS 3213 Memory: 15208k available (700k kernel code, 444k data, 32k init) [c0000000,c1000000] 3214 ... 3215 3216If you want to boot a Linux kernel with initial ram disk, you pass 3217the memory addresses of both the kernel and the initrd image (PPBCOOT 3218format!) to the "bootm" command: 3219 3220 => imi 40100000 40200000 3221 3222 ## Checking Image at 40100000 ... 3223 Image Name: 2.2.13 for initrd on TQM850L 3224 Image Type: PowerPC Linux Kernel Image (gzip compressed) 3225 Data Size: 335725 Bytes = 327 kB = 0 MB 3226 Load Address: 00000000 3227 Entry Point: 0000000c 3228 Verifying Checksum ... OK 3229 3230 ## Checking Image at 40200000 ... 3231 Image Name: Simple Ramdisk Image 3232 Image Type: PowerPC Linux RAMDisk Image (gzip compressed) 3233 Data Size: 566530 Bytes = 553 kB = 0 MB 3234 Load Address: 00000000 3235 Entry Point: 00000000 3236 Verifying Checksum ... OK 3237 3238 => bootm 40100000 40200000 3239 ## Booting Linux kernel at 40100000 ... 3240 Image Name: 2.2.13 for initrd on TQM850L 3241 Image Type: PowerPC Linux Kernel Image (gzip compressed) 3242 Data Size: 335725 Bytes = 327 kB = 0 MB 3243 Load Address: 00000000 3244 Entry Point: 0000000c 3245 Verifying Checksum ... OK 3246 Uncompressing Kernel Image ... OK 3247 ## Loading RAMDisk Image at 40200000 ... 3248 Image Name: Simple Ramdisk Image 3249 Image Type: PowerPC Linux RAMDisk Image (gzip compressed) 3250 Data Size: 566530 Bytes = 553 kB = 0 MB 3251 Load Address: 00000000 3252 Entry Point: 00000000 3253 Verifying Checksum ... OK 3254 Loading Ramdisk ... OK 3255 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 3256 Boot arguments: root=/dev/ram 3257 time_init: decrementer frequency = 187500000/60 3258 Calibrating delay loop... 49.77 BogoMIPS 3259 ... 3260 RAMDISK: Compressed image found at block 0 3261 VFS: Mounted root (ext2 filesystem). 3262 3263 bash# 3264 3265Boot Linux and pass a flat device tree: 3266----------- 3267 3268First, U-Boot must be compiled with the appropriate defines. See the section 3269titled "Linux Kernel Interface" above for a more in depth explanation. The 3270following is an example of how to start a kernel and pass an updated 3271flat device tree: 3272 3273=> print oftaddr 3274oftaddr=0x300000 3275=> print oft 3276oft=oftrees/mpc8540ads.dtb 3277=> tftp $oftaddr $oft 3278Speed: 1000, full duplex 3279Using TSEC0 device 3280TFTP from server 192.168.1.1; our IP address is 192.168.1.101 3281Filename 'oftrees/mpc8540ads.dtb'. 3282Load address: 0x300000 3283Loading: # 3284done 3285Bytes transferred = 4106 (100a hex) 3286=> tftp $loadaddr $bootfile 3287Speed: 1000, full duplex 3288Using TSEC0 device 3289TFTP from server 192.168.1.1; our IP address is 192.168.1.2 3290Filename 'uImage'. 3291Load address: 0x200000 3292Loading:############ 3293done 3294Bytes transferred = 1029407 (fb51f hex) 3295=> print loadaddr 3296loadaddr=200000 3297=> print oftaddr 3298oftaddr=0x300000 3299=> bootm $loadaddr - $oftaddr 3300## Booting image at 00200000 ... 3301 Image Name: Linux-2.6.17-dirty 3302 Image Type: PowerPC Linux Kernel Image (gzip compressed) 3303 Data Size: 1029343 Bytes = 1005.2 kB 3304 Load Address: 00000000 3305 Entry Point: 00000000 3306 Verifying Checksum ... OK 3307 Uncompressing Kernel Image ... OK 3308Booting using flat device tree at 0x300000 3309Using MPC85xx ADS machine description 3310Memory CAM mapping: CAM0=256Mb, CAM1=256Mb, CAM2=0Mb residual: 0Mb 3311[snip] 3312 3313 3314More About U-Boot Image Types: 3315------------------------------ 3316 3317U-Boot supports the following image types: 3318 3319 "Standalone Programs" are directly runnable in the environment 3320 provided by U-Boot; it is expected that (if they behave 3321 well) you can continue to work in U-Boot after return from 3322 the Standalone Program. 3323 "OS Kernel Images" are usually images of some Embedded OS which 3324 will take over control completely. Usually these programs 3325 will install their own set of exception handlers, device 3326 drivers, set up the MMU, etc. - this means, that you cannot 3327 expect to re-enter U-Boot except by resetting the CPU. 3328 "RAMDisk Images" are more or less just data blocks, and their 3329 parameters (address, size) are passed to an OS kernel that is 3330 being started. 3331 "Multi-File Images" contain several images, typically an OS 3332 (Linux) kernel image and one or more data images like 3333 RAMDisks. This construct is useful for instance when you want 3334 to boot over the network using BOOTP etc., where the boot 3335 server provides just a single image file, but you want to get 3336 for instance an OS kernel and a RAMDisk image. 3337 3338 "Multi-File Images" start with a list of image sizes, each 3339 image size (in bytes) specified by an "uint32_t" in network 3340 byte order. This list is terminated by an "(uint32_t)0". 3341 Immediately after the terminating 0 follow the images, one by 3342 one, all aligned on "uint32_t" boundaries (size rounded up to 3343 a multiple of 4 bytes). 3344 3345 "Firmware Images" are binary images containing firmware (like 3346 U-Boot or FPGA images) which usually will be programmed to 3347 flash memory. 3348 3349 "Script files" are command sequences that will be executed by 3350 U-Boot's command interpreter; this feature is especially 3351 useful when you configure U-Boot to use a real shell (hush) 3352 as command interpreter. 3353 3354 3355Standalone HOWTO: 3356================= 3357 3358One of the features of U-Boot is that you can dynamically load and 3359run "standalone" applications, which can use some resources of 3360U-Boot like console I/O functions or interrupt services. 3361 3362Two simple examples are included with the sources: 3363 3364"Hello World" Demo: 3365------------------- 3366 3367'examples/hello_world.c' contains a small "Hello World" Demo 3368application; it is automatically compiled when you build U-Boot. 3369It's configured to run at address 0x00040004, so you can play with it 3370like that: 3371 3372 => loads 3373 ## Ready for S-Record download ... 3374 ~>examples/hello_world.srec 3375 1 2 3 4 5 6 7 8 9 10 11 ... 3376 [file transfer complete] 3377 [connected] 3378 ## Start Addr = 0x00040004 3379 3380 => go 40004 Hello World! This is a test. 3381 ## Starting application at 0x00040004 ... 3382 Hello World 3383 argc = 7 3384 argv[0] = "40004" 3385 argv[1] = "Hello" 3386 argv[2] = "World!" 3387 argv[3] = "This" 3388 argv[4] = "is" 3389 argv[5] = "a" 3390 argv[6] = "test." 3391 argv[7] = "<NULL>" 3392 Hit any key to exit ... 3393 3394 ## Application terminated, rc = 0x0 3395 3396Another example, which demonstrates how to register a CPM interrupt 3397handler with the U-Boot code, can be found in 'examples/timer.c'. 3398Here, a CPM timer is set up to generate an interrupt every second. 3399The interrupt service routine is trivial, just printing a '.' 3400character, but this is just a demo program. The application can be 3401controlled by the following keys: 3402 3403 ? - print current values og the CPM Timer registers 3404 b - enable interrupts and start timer 3405 e - stop timer and disable interrupts 3406 q - quit application 3407 3408 => loads 3409 ## Ready for S-Record download ... 3410 ~>examples/timer.srec 3411 1 2 3 4 5 6 7 8 9 10 11 ... 3412 [file transfer complete] 3413 [connected] 3414 ## Start Addr = 0x00040004 3415 3416 => go 40004 3417 ## Starting application at 0x00040004 ... 3418 TIMERS=0xfff00980 3419 Using timer 1 3420 tgcr @ 0xfff00980, tmr @ 0xfff00990, trr @ 0xfff00994, tcr @ 0xfff00998, tcn @ 0xfff0099c, ter @ 0xfff009b0 3421 3422Hit 'b': 3423 [q, b, e, ?] Set interval 1000000 us 3424 Enabling timer 3425Hit '?': 3426 [q, b, e, ?] ........ 3427 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0xef6, ter=0x0 3428Hit '?': 3429 [q, b, e, ?] . 3430 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x2ad4, ter=0x0 3431Hit '?': 3432 [q, b, e, ?] . 3433 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x1efc, ter=0x0 3434Hit '?': 3435 [q, b, e, ?] . 3436 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x169d, ter=0x0 3437Hit 'e': 3438 [q, b, e, ?] ...Stopping timer 3439Hit 'q': 3440 [q, b, e, ?] ## Application terminated, rc = 0x0 3441 3442 3443Minicom warning: 3444================ 3445 3446Over time, many people have reported problems when trying to use the 3447"minicom" terminal emulation program for serial download. I (wd) 3448consider minicom to be broken, and recommend not to use it. Under 3449Unix, I recommend to use C-Kermit for general purpose use (and 3450especially for kermit binary protocol download ("loadb" command), and 3451use "cu" for S-Record download ("loads" command). 3452 3453Nevertheless, if you absolutely want to use it try adding this 3454configuration to your "File transfer protocols" section: 3455 3456 Name Program Name U/D FullScr IO-Red. Multi 3457 X kermit /usr/bin/kermit -i -l %l -s Y U Y N N 3458 Y kermit /usr/bin/kermit -i -l %l -r N D Y N N 3459 3460 3461NetBSD Notes: 3462============= 3463 3464Starting at version 0.9.2, U-Boot supports NetBSD both as host 3465(build U-Boot) and target system (boots NetBSD/mpc8xx). 3466 3467Building requires a cross environment; it is known to work on 3468NetBSD/i386 with the cross-powerpc-netbsd-1.3 package (you will also 3469need gmake since the Makefiles are not compatible with BSD make). 3470Note that the cross-powerpc package does not install include files; 3471attempting to build U-Boot will fail because <machine/ansi.h> is 3472missing. This file has to be installed and patched manually: 3473 3474 # cd /usr/pkg/cross/powerpc-netbsd/include 3475 # mkdir powerpc 3476 # ln -s powerpc machine 3477 # cp /usr/src/sys/arch/powerpc/include/ansi.h powerpc/ansi.h 3478 # ${EDIT} powerpc/ansi.h ## must remove __va_list, _BSD_VA_LIST 3479 3480Native builds *don't* work due to incompatibilities between native 3481and U-Boot include files. 3482 3483Booting assumes that (the first part of) the image booted is a 3484stage-2 loader which in turn loads and then invokes the kernel 3485proper. Loader sources will eventually appear in the NetBSD source 3486tree (probably in sys/arc/mpc8xx/stand/u-boot_stage2/); in the 3487meantime, see ftp://ftp.denx.de/pub/u-boot/ppcboot_stage2.tar.gz 3488 3489 3490Implementation Internals: 3491========================= 3492 3493The following is not intended to be a complete description of every 3494implementation detail. However, it should help to understand the 3495inner workings of U-Boot and make it easier to port it to custom 3496hardware. 3497 3498 3499Initial Stack, Global Data: 3500--------------------------- 3501 3502The implementation of U-Boot is complicated by the fact that U-Boot 3503starts running out of ROM (flash memory), usually without access to 3504system RAM (because the memory controller is not initialized yet). 3505This means that we don't have writable Data or BSS segments, and BSS 3506is not initialized as zero. To be able to get a C environment working 3507at all, we have to allocate at least a minimal stack. Implementation 3508options for this are defined and restricted by the CPU used: Some CPU 3509models provide on-chip memory (like the IMMR area on MPC8xx and 3510MPC826x processors), on others (parts of) the data cache can be 3511locked as (mis-) used as memory, etc. 3512 3513 Chris Hallinan posted a good summary of these issues to the 3514 u-boot-users mailing list: 3515 3516 Subject: RE: [U-Boot-Users] RE: More On Memory Bank x (nothingness)? 3517 From: "Chris Hallinan" <clh@net1plus.com> 3518 Date: Mon, 10 Feb 2003 16:43:46 -0500 (22:43 MET) 3519 ... 3520 3521 Correct me if I'm wrong, folks, but the way I understand it 3522 is this: Using DCACHE as initial RAM for Stack, etc, does not 3523 require any physical RAM backing up the cache. The cleverness 3524 is that the cache is being used as a temporary supply of 3525 necessary storage before the SDRAM controller is setup. It's 3526 beyond the scope of this list to expain the details, but you 3527 can see how this works by studying the cache architecture and 3528 operation in the architecture and processor-specific manuals. 3529 3530 OCM is On Chip Memory, which I believe the 405GP has 4K. It 3531 is another option for the system designer to use as an 3532 initial stack/ram area prior to SDRAM being available. Either 3533 option should work for you. Using CS 4 should be fine if your 3534 board designers haven't used it for something that would 3535 cause you grief during the initial boot! It is frequently not 3536 used. 3537 3538 CFG_INIT_RAM_ADDR should be somewhere that won't interfere 3539 with your processor/board/system design. The default value 3540 you will find in any recent u-boot distribution in 3541 walnut.h should work for you. I'd set it to a value larger 3542 than your SDRAM module. If you have a 64MB SDRAM module, set 3543 it above 400_0000. Just make sure your board has no resources 3544 that are supposed to respond to that address! That code in 3545 start.S has been around a while and should work as is when 3546 you get the config right. 3547 3548 -Chris Hallinan 3549 DS4.COM, Inc. 3550 3551It is essential to remember this, since it has some impact on the C 3552code for the initialization procedures: 3553 3554* Initialized global data (data segment) is read-only. Do not attempt 3555 to write it. 3556 3557* Do not use any unitialized global data (or implicitely initialized 3558 as zero data - BSS segment) at all - this is undefined, initiali- 3559 zation is performed later (when relocating to RAM). 3560 3561* Stack space is very limited. Avoid big data buffers or things like 3562 that. 3563 3564Having only the stack as writable memory limits means we cannot use 3565normal global data to share information beween the code. But it 3566turned out that the implementation of U-Boot can be greatly 3567simplified by making a global data structure (gd_t) available to all 3568functions. We could pass a pointer to this data as argument to _all_ 3569functions, but this would bloat the code. Instead we use a feature of 3570the GCC compiler (Global Register Variables) to share the data: we 3571place a pointer (gd) to the global data into a register which we 3572reserve for this purpose. 3573 3574When choosing a register for such a purpose we are restricted by the 3575relevant (E)ABI specifications for the current architecture, and by 3576GCC's implementation. 3577 3578For PowerPC, the following registers have specific use: 3579 R1: stack pointer 3580 R2: reserved for system use 3581 R3-R4: parameter passing and return values 3582 R5-R10: parameter passing 3583 R13: small data area pointer 3584 R30: GOT pointer 3585 R31: frame pointer 3586 3587 (U-Boot also uses R14 as internal GOT pointer.) 3588 3589 ==> U-Boot will use R2 to hold a pointer to the global data 3590 3591 Note: on PPC, we could use a static initializer (since the 3592 address of the global data structure is known at compile time), 3593 but it turned out that reserving a register results in somewhat 3594 smaller code - although the code savings are not that big (on 3595 average for all boards 752 bytes for the whole U-Boot image, 3596 624 text + 127 data). 3597 3598On Blackfin, the normal C ABI (except for P5) is followed as documented here: 3599 http://docs.blackfin.uclinux.org/doku.php?id=application_binary_interface 3600 3601 ==> U-Boot will use P5 to hold a pointer to the global data 3602 3603On ARM, the following registers are used: 3604 3605 R0: function argument word/integer result 3606 R1-R3: function argument word 3607 R9: GOT pointer 3608 R10: stack limit (used only if stack checking if enabled) 3609 R11: argument (frame) pointer 3610 R12: temporary workspace 3611 R13: stack pointer 3612 R14: link register 3613 R15: program counter 3614 3615 ==> U-Boot will use R8 to hold a pointer to the global data 3616 3617NOTE: DECLARE_GLOBAL_DATA_PTR must be used with file-global scope, 3618or current versions of GCC may "optimize" the code too much. 3619 3620Memory Management: 3621------------------ 3622 3623U-Boot runs in system state and uses physical addresses, i.e. the 3624MMU is not used either for address mapping nor for memory protection. 3625 3626The available memory is mapped to fixed addresses using the memory 3627controller. In this process, a contiguous block is formed for each 3628memory type (Flash, SDRAM, SRAM), even when it consists of several 3629physical memory banks. 3630 3631U-Boot is installed in the first 128 kB of the first Flash bank (on 3632TQM8xxL modules this is the range 0x40000000 ... 0x4001FFFF). After 3633booting and sizing and initializing DRAM, the code relocates itself 3634to the upper end of DRAM. Immediately below the U-Boot code some 3635memory is reserved for use by malloc() [see CFG_MALLOC_LEN 3636configuration setting]. Below that, a structure with global Board 3637Info data is placed, followed by the stack (growing downward). 3638 3639Additionally, some exception handler code is copied to the low 8 kB 3640of DRAM (0x00000000 ... 0x00001FFF). 3641 3642So a typical memory configuration with 16 MB of DRAM could look like 3643this: 3644 3645 0x0000 0000 Exception Vector code 3646 : 3647 0x0000 1FFF 3648 0x0000 2000 Free for Application Use 3649 : 3650 : 3651 3652 : 3653 : 3654 0x00FB FF20 Monitor Stack (Growing downward) 3655 0x00FB FFAC Board Info Data and permanent copy of global data 3656 0x00FC 0000 Malloc Arena 3657 : 3658 0x00FD FFFF 3659 0x00FE 0000 RAM Copy of Monitor Code 3660 ... eventually: LCD or video framebuffer 3661 ... eventually: pRAM (Protected RAM - unchanged by reset) 3662 0x00FF FFFF [End of RAM] 3663 3664 3665System Initialization: 3666---------------------- 3667 3668In the reset configuration, U-Boot starts at the reset entry point 3669(on most PowerPC systens at address 0x00000100). Because of the reset 3670configuration for CS0# this is a mirror of the onboard Flash memory. 3671To be able to re-map memory U-Boot then jumps to its link address. 3672To be able to implement the initialization code in C, a (small!) 3673initial stack is set up in the internal Dual Ported RAM (in case CPUs 3674which provide such a feature like MPC8xx or MPC8260), or in a locked 3675part of the data cache. After that, U-Boot initializes the CPU core, 3676the caches and the SIU. 3677 3678Next, all (potentially) available memory banks are mapped using a 3679preliminary mapping. For example, we put them on 512 MB boundaries 3680(multiples of 0x20000000: SDRAM on 0x00000000 and 0x20000000, Flash 3681on 0x40000000 and 0x60000000, SRAM on 0x80000000). Then UPM A is 3682programmed for SDRAM access. Using the temporary configuration, a 3683simple memory test is run that determines the size of the SDRAM 3684banks. 3685 3686When there is more than one SDRAM bank, and the banks are of 3687different size, the largest is mapped first. For equal size, the first 3688bank (CS2#) is mapped first. The first mapping is always for address 36890x00000000, with any additional banks following immediately to create 3690contiguous memory starting from 0. 3691 3692Then, the monitor installs itself at the upper end of the SDRAM area 3693and allocates memory for use by malloc() and for the global Board 3694Info data; also, the exception vector code is copied to the low RAM 3695pages, and the final stack is set up. 3696 3697Only after this relocation will you have a "normal" C environment; 3698until that you are restricted in several ways, mostly because you are 3699running from ROM, and because the code will have to be relocated to a 3700new address in RAM. 3701 3702 3703U-Boot Porting Guide: 3704---------------------- 3705 3706[Based on messages by Jerry Van Baren in the U-Boot-Users mailing 3707list, October 2002] 3708 3709 3710int main (int argc, char *argv[]) 3711{ 3712 sighandler_t no_more_time; 3713 3714 signal (SIGALRM, no_more_time); 3715 alarm (PROJECT_DEADLINE - toSec (3 * WEEK)); 3716 3717 if (available_money > available_manpower) { 3718 pay consultant to port U-Boot; 3719 return 0; 3720 } 3721 3722 Download latest U-Boot source; 3723 3724 Subscribe to u-boot-users mailing list; 3725 3726 if (clueless) { 3727 email ("Hi, I am new to U-Boot, how do I get started?"); 3728 } 3729 3730 while (learning) { 3731 Read the README file in the top level directory; 3732 Read http://www.denx.de/twiki/bin/view/DULG/Manual ; 3733 Read the source, Luke; 3734 } 3735 3736 if (available_money > toLocalCurrency ($2500)) { 3737 Buy a BDI2000; 3738 } else { 3739 Add a lot of aggravation and time; 3740 } 3741 3742 Create your own board support subdirectory; 3743 3744 Create your own board config file; 3745 3746 while (!running) { 3747 do { 3748 Add / modify source code; 3749 } until (compiles); 3750 Debug; 3751 if (clueless) 3752 email ("Hi, I am having problems..."); 3753 } 3754 Send patch file to Wolfgang; 3755 3756 return 0; 3757} 3758 3759void no_more_time (int sig) 3760{ 3761 hire_a_guru(); 3762} 3763 3764 3765Coding Standards: 3766----------------- 3767 3768All contributions to U-Boot should conform to the Linux kernel 3769coding style; see the file "Documentation/CodingStyle" and the script 3770"scripts/Lindent" in your Linux kernel source directory. In sources 3771originating from U-Boot a style corresponding to "Lindent -pcs" (adding 3772spaces before parameters to function calls) is actually used. 3773 3774Source files originating from a different project (for example the 3775MTD subsystem) are generally exempt from these guidelines and are not 3776reformated to ease subsequent migration to newer versions of those 3777sources. 3778 3779Please note that U-Boot is implemented in C (and to some small parts in 3780Assembler); no C++ is used, so please do not use C++ style comments (//) 3781in your code. 3782 3783Please also stick to the following formatting rules: 3784- remove any trailing white space 3785- use TAB characters for indentation, not spaces 3786- make sure NOT to use DOS '\r\n' line feeds 3787- do not add more than 2 empty lines to source files 3788- do not add trailing empty lines to source files 3789 3790Submissions which do not conform to the standards may be returned 3791with a request to reformat the changes. 3792 3793 3794Submitting Patches: 3795------------------- 3796 3797Since the number of patches for U-Boot is growing, we need to 3798establish some rules. Submissions which do not conform to these rules 3799may be rejected, even when they contain important and valuable stuff. 3800 3801Patches shall be sent to the u-boot-users mailing list. 3802 3803When you send a patch, please include the following information with 3804it: 3805 3806* For bug fixes: a description of the bug and how your patch fixes 3807 this bug. Please try to include a way of demonstrating that the 3808 patch actually fixes something. 3809 3810* For new features: a description of the feature and your 3811 implementation. 3812 3813* A CHANGELOG entry as plaintext (separate from the patch) 3814 3815* For major contributions, your entry to the CREDITS file 3816 3817* When you add support for a new board, don't forget to add this 3818 board to the MAKEALL script, too. 3819 3820* If your patch adds new configuration options, don't forget to 3821 document these in the README file. 3822 3823* The patch itself. If you are accessing the CVS repository use "cvs 3824 update; cvs diff -puRN"; else, use "diff -purN OLD NEW". If your 3825 version of diff does not support these options, then get the latest 3826 version of GNU diff. 3827 3828 The current directory when running this command shall be the top 3829 level directory of the U-Boot source tree, or it's parent directory 3830 (i. e. please make sure that your patch includes sufficient 3831 directory information for the affected files). 3832 3833 We accept patches as plain text, MIME attachments or as uuencoded 3834 gzipped text. 3835 3836* If one logical set of modifications affects or creates several 3837 files, all these changes shall be submitted in a SINGLE patch file. 3838 3839* Changesets that contain different, unrelated modifications shall be 3840 submitted as SEPARATE patches, one patch per changeset. 3841 3842 3843Notes: 3844 3845* Before sending the patch, run the MAKEALL script on your patched 3846 source tree and make sure that no errors or warnings are reported 3847 for any of the boards. 3848 3849* Keep your modifications to the necessary minimum: A patch 3850 containing several unrelated changes or arbitrary reformats will be 3851 returned with a request to re-formatting / split it. 3852 3853* If you modify existing code, make sure that your new code does not 3854 add to the memory footprint of the code ;-) Small is beautiful! 3855 When adding new features, these should compile conditionally only 3856 (using #ifdef), and the resulting code with the new feature 3857 disabled must not need more memory than the old code without your 3858 modification. 3859 3860* Remember that there is a size limit of 40 kB per message on the 3861 u-boot-users mailing list. Compression may help. 3862