1# 2# (C) Copyright 2000 - 2008 3# Wolfgang Denk, DENX Software Engineering, wd@denx.de. 4# 5# See file CREDITS for list of people who contributed to this 6# project. 7# 8# This program is free software; you can redistribute it and/or 9# modify it under the terms of the GNU General Public License as 10# published by the Free Software Foundation; either version 2 of 11# the License, or (at your option) any later version. 12# 13# This program is distributed in the hope that it will be useful, 14# but WITHOUT ANY WARRANTY; without even the implied warranty of 15# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 16# GNU General Public License for more details. 17# 18# You should have received a copy of the GNU General Public License 19# along with this program; if not, write to the Free Software 20# Foundation, Inc., 59 Temple Place, Suite 330, Boston, 21# MA 02111-1307 USA 22# 23 24Summary: 25======== 26 27This directory contains the source code for U-Boot, a boot loader for 28Embedded boards based on PowerPC, ARM, MIPS and several other 29processors, which can be installed in a boot ROM and used to 30initialize and test the hardware or to download and run application 31code. 32 33The development of U-Boot is closely related to Linux: some parts of 34the source code originate in the Linux source tree, we have some 35header files in common, and special provision has been made to 36support booting of Linux images. 37 38Some attention has been paid to make this software easily 39configurable and extendable. For instance, all monitor commands are 40implemented with the same call interface, so that it's very easy to 41add new commands. Also, instead of permanently adding rarely used 42code (for instance hardware test utilities) to the monitor, you can 43load and run it dynamically. 44 45 46Status: 47======= 48 49In general, all boards for which a configuration option exists in the 50Makefile have been tested to some extent and can be considered 51"working". In fact, many of them are used in production systems. 52 53In case of problems see the CHANGELOG and CREDITS files to find out 54who contributed the specific port. The MAINTAINERS file lists board 55maintainers. 56 57 58Where to get help: 59================== 60 61In case you have questions about, problems with or contributions for 62U-Boot you should send a message to the U-Boot mailing list at 63<u-boot-users@lists.sourceforge.net>. There is also an archive of 64previous traffic on the mailing list - please search the archive 65before asking FAQ's. Please see 66http://lists.sourceforge.net/lists/listinfo/u-boot-users/ 67 68 69Where to get source code: 70========================= 71 72The U-Boot source code is maintained in the git repository at 73git://www.denx.de/git/u-boot.git ; you can browse it online at 74http://www.denx.de/cgi-bin/gitweb.cgi?p=u-boot.git;a=summary 75 76The "snapshot" links on this page allow you to download tarballs of 77any version you might be interested in. Ofifcial releases are also 78available for FTP download from the ftp://ftp.denx.de/pub/u-boot/ 79directory. 80 81Pre-build (and tested) images are available from 82ftp://ftp.denx.de/pub/u-boot/images/ 83 84 85Where we come from: 86=================== 87 88- start from 8xxrom sources 89- create PPCBoot project (http://sourceforge.net/projects/ppcboot) 90- clean up code 91- make it easier to add custom boards 92- make it possible to add other [PowerPC] CPUs 93- extend functions, especially: 94 * Provide extended interface to Linux boot loader 95 * S-Record download 96 * network boot 97 * PCMCIA / CompactFLash / ATA disk / SCSI ... boot 98- create ARMBoot project (http://sourceforge.net/projects/armboot) 99- add other CPU families (starting with ARM) 100- create U-Boot project (http://sourceforge.net/projects/u-boot) 101- current project page: see http://www.denx.de/wiki/UBoot 102 103 104Names and Spelling: 105=================== 106 107The "official" name of this project is "Das U-Boot". The spelling 108"U-Boot" shall be used in all written text (documentation, comments 109in source files etc.). Example: 110 111 This is the README file for the U-Boot project. 112 113File names etc. shall be based on the string "u-boot". Examples: 114 115 include/asm-ppc/u-boot.h 116 117 #include <asm/u-boot.h> 118 119Variable names, preprocessor constants etc. shall be either based on 120the string "u_boot" or on "U_BOOT". Example: 121 122 U_BOOT_VERSION u_boot_logo 123 IH_OS_U_BOOT u_boot_hush_start 124 125 126Versioning: 127=========== 128 129U-Boot uses a 3 level version number containing a version, a 130sub-version, and a patchlevel: "U-Boot-2.34.5" means version "2", 131sub-version "34", and patchlevel "4". 132 133The patchlevel is used to indicate certain stages of development 134between released versions, i. e. officially released versions of 135U-Boot will always have a patchlevel of "0". 136 137 138Directory Hierarchy: 139==================== 140 141- board Board dependent files 142- common Misc architecture independent functions 143- cpu CPU specific files 144 - 74xx_7xx Files specific to Freescale MPC74xx and 7xx CPUs 145 - arm720t Files specific to ARM 720 CPUs 146 - arm920t Files specific to ARM 920 CPUs 147 - at91rm9200 Files specific to Atmel AT91RM9200 CPU 148 - imx Files specific to Freescale MC9328 i.MX CPUs 149 - s3c24x0 Files specific to Samsung S3C24X0 CPUs 150 - arm925t Files specific to ARM 925 CPUs 151 - arm926ejs Files specific to ARM 926 CPUs 152 - arm1136 Files specific to ARM 1136 CPUs 153 - at32ap Files specific to Atmel AVR32 AP CPUs 154 - i386 Files specific to i386 CPUs 155 - ixp Files specific to Intel XScale IXP CPUs 156 - mcf52x2 Files specific to Freescale ColdFire MCF52x2 CPUs 157 - mcf5227x Files specific to Freescale ColdFire MCF5227x CPUs 158 - mcf532x Files specific to Freescale ColdFire MCF5329 CPUs 159 - mcf5445x Files specific to Freescale ColdFire MCF5445x CPUs 160 - mcf547x_8x Files specific to Freescale ColdFire MCF547x_8x CPUs 161 - mips Files specific to MIPS CPUs 162 - mpc5xx Files specific to Freescale MPC5xx CPUs 163 - mpc5xxx Files specific to Freescale MPC5xxx CPUs 164 - mpc8xx Files specific to Freescale MPC8xx CPUs 165 - mpc8220 Files specific to Freescale MPC8220 CPUs 166 - mpc824x Files specific to Freescale MPC824x CPUs 167 - mpc8260 Files specific to Freescale MPC8260 CPUs 168 - mpc85xx Files specific to Freescale MPC85xx CPUs 169 - nios Files specific to Altera NIOS CPUs 170 - nios2 Files specific to Altera Nios-II CPUs 171 - ppc4xx Files specific to AMCC PowerPC 4xx CPUs 172 - pxa Files specific to Intel XScale PXA CPUs 173 - s3c44b0 Files specific to Samsung S3C44B0 CPUs 174 - sa1100 Files specific to Intel StrongARM SA1100 CPUs 175- disk Code for disk drive partition handling 176- doc Documentation (don't expect too much) 177- drivers Commonly used device drivers 178- dtt Digital Thermometer and Thermostat drivers 179- examples Example code for standalone applications, etc. 180- include Header Files 181- lib_arm Files generic to ARM architecture 182- lib_avr32 Files generic to AVR32 architecture 183- lib_generic Files generic to all architectures 184- lib_i386 Files generic to i386 architecture 185- lib_m68k Files generic to m68k architecture 186- lib_mips Files generic to MIPS architecture 187- lib_nios Files generic to NIOS architecture 188- lib_ppc Files generic to PowerPC architecture 189- libfdt Library files to support flattened device trees 190- net Networking code 191- post Power On Self Test 192- rtc Real Time Clock drivers 193- tools Tools to build S-Record or U-Boot images, etc. 194 195Software Configuration: 196======================= 197 198Configuration is usually done using C preprocessor defines; the 199rationale behind that is to avoid dead code whenever possible. 200 201There are two classes of configuration variables: 202 203* Configuration _OPTIONS_: 204 These are selectable by the user and have names beginning with 205 "CONFIG_". 206 207* Configuration _SETTINGS_: 208 These depend on the hardware etc. and should not be meddled with if 209 you don't know what you're doing; they have names beginning with 210 "CFG_". 211 212Later we will add a configuration tool - probably similar to or even 213identical to what's used for the Linux kernel. Right now, we have to 214do the configuration by hand, which means creating some symbolic 215links and editing some configuration files. We use the TQM8xxL boards 216as an example here. 217 218 219Selection of Processor Architecture and Board Type: 220--------------------------------------------------- 221 222For all supported boards there are ready-to-use default 223configurations available; just type "make <board_name>_config". 224 225Example: For a TQM823L module type: 226 227 cd u-boot 228 make TQM823L_config 229 230For the Cogent platform, you need to specify the cpu type as well; 231e.g. "make cogent_mpc8xx_config". And also configure the cogent 232directory according to the instructions in cogent/README. 233 234 235Configuration Options: 236---------------------- 237 238Configuration depends on the combination of board and CPU type; all 239such information is kept in a configuration file 240"include/configs/<board_name>.h". 241 242Example: For a TQM823L module, all configuration settings are in 243"include/configs/TQM823L.h". 244 245 246Many of the options are named exactly as the corresponding Linux 247kernel configuration options. The intention is to make it easier to 248build a config tool - later. 249 250 251The following options need to be configured: 252 253- CPU Type: Define exactly one, e.g. CONFIG_MPC85XX. 254 255- Board Type: Define exactly one, e.g. CONFIG_MPC8540ADS. 256 257- CPU Daughterboard Type: (if CONFIG_ATSTK1000 is defined) 258 Define exactly one, e.g. CONFIG_ATSTK1002 259 260- CPU Module Type: (if CONFIG_COGENT is defined) 261 Define exactly one of 262 CONFIG_CMA286_60_OLD 263--- FIXME --- not tested yet: 264 CONFIG_CMA286_60, CONFIG_CMA286_21, CONFIG_CMA286_60P, 265 CONFIG_CMA287_23, CONFIG_CMA287_50 266 267- Motherboard Type: (if CONFIG_COGENT is defined) 268 Define exactly one of 269 CONFIG_CMA101, CONFIG_CMA102 270 271- Motherboard I/O Modules: (if CONFIG_COGENT is defined) 272 Define one or more of 273 CONFIG_CMA302 274 275- Motherboard Options: (if CONFIG_CMA101 or CONFIG_CMA102 are defined) 276 Define one or more of 277 CONFIG_LCD_HEARTBEAT - update a character position on 278 the lcd display every second with 279 a "rotator" |\-/|\-/ 280 281- Board flavour: (if CONFIG_MPC8260ADS is defined) 282 CONFIG_ADSTYPE 283 Possible values are: 284 CFG_8260ADS - original MPC8260ADS 285 CFG_8266ADS - MPC8266ADS 286 CFG_PQ2FADS - PQ2FADS-ZU or PQ2FADS-VR 287 CFG_8272ADS - MPC8272ADS 288 289- MPC824X Family Member (if CONFIG_MPC824X is defined) 290 Define exactly one of 291 CONFIG_MPC8240, CONFIG_MPC8245 292 293- 8xx CPU Options: (if using an MPC8xx cpu) 294 CONFIG_8xx_GCLK_FREQ - deprecated: CPU clock if 295 get_gclk_freq() cannot work 296 e.g. if there is no 32KHz 297 reference PIT/RTC clock 298 CONFIG_8xx_OSCLK - PLL input clock (either EXTCLK 299 or XTAL/EXTAL) 300 301- 859/866/885 CPU options: (if using a MPC859 or MPC866 or MPC885 CPU): 302 CFG_8xx_CPUCLK_MIN 303 CFG_8xx_CPUCLK_MAX 304 CONFIG_8xx_CPUCLK_DEFAULT 305 See doc/README.MPC866 306 307 CFG_MEASURE_CPUCLK 308 309 Define this to measure the actual CPU clock instead 310 of relying on the correctness of the configured 311 values. Mostly useful for board bringup to make sure 312 the PLL is locked at the intended frequency. Note 313 that this requires a (stable) reference clock (32 kHz 314 RTC clock or CFG_8XX_XIN) 315 316- Intel Monahans options: 317 CFG_MONAHANS_RUN_MODE_OSC_RATIO 318 319 Defines the Monahans run mode to oscillator 320 ratio. Valid values are 8, 16, 24, 31. The core 321 frequency is this value multiplied by 13 MHz. 322 323 CFG_MONAHANS_TURBO_RUN_MODE_RATIO 324 325 Defines the Monahans turbo mode to oscillator 326 ratio. Valid values are 1 (default if undefined) and 327 2. The core frequency as calculated above is multiplied 328 by this value. 329 330- Linux Kernel Interface: 331 CONFIG_CLOCKS_IN_MHZ 332 333 U-Boot stores all clock information in Hz 334 internally. For binary compatibility with older Linux 335 kernels (which expect the clocks passed in the 336 bd_info data to be in MHz) the environment variable 337 "clocks_in_mhz" can be defined so that U-Boot 338 converts clock data to MHZ before passing it to the 339 Linux kernel. 340 When CONFIG_CLOCKS_IN_MHZ is defined, a definition of 341 "clocks_in_mhz=1" is automatically included in the 342 default environment. 343 344 CONFIG_MEMSIZE_IN_BYTES [relevant for MIPS only] 345 346 When transfering memsize parameter to linux, some versions 347 expect it to be in bytes, others in MB. 348 Define CONFIG_MEMSIZE_IN_BYTES to make it in bytes. 349 350 CONFIG_OF_LIBFDT / CONFIG_OF_FLAT_TREE 351 352 New kernel versions are expecting firmware settings to be 353 passed using flattened device trees (based on open firmware 354 concepts). 355 356 CONFIG_OF_LIBFDT 357 * New libfdt-based support 358 * Adds the "fdt" command 359 * The bootm command automatically updates the fdt 360 361 CONFIG_OF_FLAT_TREE 362 * Deprecated, see CONFIG_OF_LIBFDT 363 * Original ft_build.c-based support 364 * Automatically modifies the dft as part of the bootm command 365 * The environment variable "disable_of", when set, 366 disables this functionality. 367 368 OF_CPU - The proper name of the cpus node. 369 OF_SOC - The proper name of the soc node. 370 OF_TBCLK - The timebase frequency. 371 OF_STDOUT_PATH - The path to the console device 372 373 boards with QUICC Engines require OF_QE to set UCC mac addresses 374 375 CONFIG_OF_HAS_BD_T 376 377 * CONFIG_OF_LIBFDT - enables the "fdt bd_t" command 378 * CONFIG_OF_FLAT_TREE - The resulting flat device tree 379 will have a copy of the bd_t. Space should be 380 pre-allocated in the dts for the bd_t. 381 382 CONFIG_OF_HAS_UBOOT_ENV 383 384 * CONFIG_OF_LIBFDT - enables the "fdt env" command 385 * CONFIG_OF_FLAT_TREE - The resulting flat device tree 386 will have a copy of u-boot's environment variables 387 388 CONFIG_OF_BOARD_SETUP 389 390 Board code has addition modification that it wants to make 391 to the flat device tree before handing it off to the kernel 392 393 CONFIG_OF_BOOT_CPU 394 395 This define fills in the correct boot cpu in the boot 396 param header, the default value is zero if undefined. 397 398- Serial Ports: 399 CFG_PL010_SERIAL 400 401 Define this if you want support for Amba PrimeCell PL010 UARTs. 402 403 CFG_PL011_SERIAL 404 405 Define this if you want support for Amba PrimeCell PL011 UARTs. 406 407 CONFIG_PL011_CLOCK 408 409 If you have Amba PrimeCell PL011 UARTs, set this variable to 410 the clock speed of the UARTs. 411 412 CONFIG_PL01x_PORTS 413 414 If you have Amba PrimeCell PL010 or PL011 UARTs on your board, 415 define this to a list of base addresses for each (supported) 416 port. See e.g. include/configs/versatile.h 417 418 419- Console Interface: 420 Depending on board, define exactly one serial port 421 (like CONFIG_8xx_CONS_SMC1, CONFIG_8xx_CONS_SMC2, 422 CONFIG_8xx_CONS_SCC1, ...), or switch off the serial 423 console by defining CONFIG_8xx_CONS_NONE 424 425 Note: if CONFIG_8xx_CONS_NONE is defined, the serial 426 port routines must be defined elsewhere 427 (i.e. serial_init(), serial_getc(), ...) 428 429 CONFIG_CFB_CONSOLE 430 Enables console device for a color framebuffer. Needs following 431 defines (cf. smiLynxEM, i8042, board/eltec/bab7xx) 432 VIDEO_FB_LITTLE_ENDIAN graphic memory organisation 433 (default big endian) 434 VIDEO_HW_RECTFILL graphic chip supports 435 rectangle fill 436 (cf. smiLynxEM) 437 VIDEO_HW_BITBLT graphic chip supports 438 bit-blit (cf. smiLynxEM) 439 VIDEO_VISIBLE_COLS visible pixel columns 440 (cols=pitch) 441 VIDEO_VISIBLE_ROWS visible pixel rows 442 VIDEO_PIXEL_SIZE bytes per pixel 443 VIDEO_DATA_FORMAT graphic data format 444 (0-5, cf. cfb_console.c) 445 VIDEO_FB_ADRS framebuffer address 446 VIDEO_KBD_INIT_FCT keyboard int fct 447 (i.e. i8042_kbd_init()) 448 VIDEO_TSTC_FCT test char fct 449 (i.e. i8042_tstc) 450 VIDEO_GETC_FCT get char fct 451 (i.e. i8042_getc) 452 CONFIG_CONSOLE_CURSOR cursor drawing on/off 453 (requires blink timer 454 cf. i8042.c) 455 CFG_CONSOLE_BLINK_COUNT blink interval (cf. i8042.c) 456 CONFIG_CONSOLE_TIME display time/date info in 457 upper right corner 458 (requires CONFIG_CMD_DATE) 459 CONFIG_VIDEO_LOGO display Linux logo in 460 upper left corner 461 CONFIG_VIDEO_BMP_LOGO use bmp_logo.h instead of 462 linux_logo.h for logo. 463 Requires CONFIG_VIDEO_LOGO 464 CONFIG_CONSOLE_EXTRA_INFO 465 addional board info beside 466 the logo 467 468 When CONFIG_CFB_CONSOLE is defined, video console is 469 default i/o. Serial console can be forced with 470 environment 'console=serial'. 471 472 When CONFIG_SILENT_CONSOLE is defined, all console 473 messages (by U-Boot and Linux!) can be silenced with 474 the "silent" environment variable. See 475 doc/README.silent for more information. 476 477- Console Baudrate: 478 CONFIG_BAUDRATE - in bps 479 Select one of the baudrates listed in 480 CFG_BAUDRATE_TABLE, see below. 481 CFG_BRGCLK_PRESCALE, baudrate prescale 482 483- Interrupt driven serial port input: 484 CONFIG_SERIAL_SOFTWARE_FIFO 485 486 PPC405GP only. 487 Use an interrupt handler for receiving data on the 488 serial port. It also enables using hardware handshake 489 (RTS/CTS) and UART's built-in FIFO. Set the number of 490 bytes the interrupt driven input buffer should have. 491 492 Leave undefined to disable this feature, including 493 disable the buffer and hardware handshake. 494 495- Console UART Number: 496 CONFIG_UART1_CONSOLE 497 498 AMCC PPC4xx only. 499 If defined internal UART1 (and not UART0) is used 500 as default U-Boot console. 501 502- Boot Delay: CONFIG_BOOTDELAY - in seconds 503 Delay before automatically booting the default image; 504 set to -1 to disable autoboot. 505 506 See doc/README.autoboot for these options that 507 work with CONFIG_BOOTDELAY. None are required. 508 CONFIG_BOOT_RETRY_TIME 509 CONFIG_BOOT_RETRY_MIN 510 CONFIG_AUTOBOOT_KEYED 511 CONFIG_AUTOBOOT_PROMPT 512 CONFIG_AUTOBOOT_DELAY_STR 513 CONFIG_AUTOBOOT_STOP_STR 514 CONFIG_AUTOBOOT_DELAY_STR2 515 CONFIG_AUTOBOOT_STOP_STR2 516 CONFIG_ZERO_BOOTDELAY_CHECK 517 CONFIG_RESET_TO_RETRY 518 519- Autoboot Command: 520 CONFIG_BOOTCOMMAND 521 Only needed when CONFIG_BOOTDELAY is enabled; 522 define a command string that is automatically executed 523 when no character is read on the console interface 524 within "Boot Delay" after reset. 525 526 CONFIG_BOOTARGS 527 This can be used to pass arguments to the bootm 528 command. The value of CONFIG_BOOTARGS goes into the 529 environment value "bootargs". 530 531 CONFIG_RAMBOOT and CONFIG_NFSBOOT 532 The value of these goes into the environment as 533 "ramboot" and "nfsboot" respectively, and can be used 534 as a convenience, when switching between booting from 535 ram and nfs. 536 537- Pre-Boot Commands: 538 CONFIG_PREBOOT 539 540 When this option is #defined, the existence of the 541 environment variable "preboot" will be checked 542 immediately before starting the CONFIG_BOOTDELAY 543 countdown and/or running the auto-boot command resp. 544 entering interactive mode. 545 546 This feature is especially useful when "preboot" is 547 automatically generated or modified. For an example 548 see the LWMON board specific code: here "preboot" is 549 modified when the user holds down a certain 550 combination of keys on the (special) keyboard when 551 booting the systems 552 553- Serial Download Echo Mode: 554 CONFIG_LOADS_ECHO 555 If defined to 1, all characters received during a 556 serial download (using the "loads" command) are 557 echoed back. This might be needed by some terminal 558 emulations (like "cu"), but may as well just take 559 time on others. This setting #define's the initial 560 value of the "loads_echo" environment variable. 561 562- Kgdb Serial Baudrate: (if CONFIG_CMD_KGDB is defined) 563 CONFIG_KGDB_BAUDRATE 564 Select one of the baudrates listed in 565 CFG_BAUDRATE_TABLE, see below. 566 567- Monitor Functions: 568 Monitor commands can be included or excluded 569 from the build by using the #include files 570 "config_cmd_all.h" and #undef'ing unwanted 571 commands, or using "config_cmd_default.h" 572 and augmenting with additional #define's 573 for wanted commands. 574 575 The default command configuration includes all commands 576 except those marked below with a "*". 577 578 CONFIG_CMD_ASKENV * ask for env variable 579 CONFIG_CMD_AUTOSCRIPT Autoscript Support 580 CONFIG_CMD_BDI bdinfo 581 CONFIG_CMD_BEDBUG * Include BedBug Debugger 582 CONFIG_CMD_BMP * BMP support 583 CONFIG_CMD_BSP * Board specific commands 584 CONFIG_CMD_BOOTD bootd 585 CONFIG_CMD_CACHE * icache, dcache 586 CONFIG_CMD_CONSOLE coninfo 587 CONFIG_CMD_DATE * support for RTC, date/time... 588 CONFIG_CMD_DHCP * DHCP support 589 CONFIG_CMD_DIAG * Diagnostics 590 CONFIG_CMD_DOC * Disk-On-Chip Support 591 CONFIG_CMD_DTT * Digital Therm and Thermostat 592 CONFIG_CMD_ECHO echo arguments 593 CONFIG_CMD_EEPROM * EEPROM read/write support 594 CONFIG_CMD_ELF * bootelf, bootvx 595 CONFIG_CMD_ENV saveenv 596 CONFIG_CMD_FDC * Floppy Disk Support 597 CONFIG_CMD_FAT * FAT partition support 598 CONFIG_CMD_FDOS * Dos diskette Support 599 CONFIG_CMD_FLASH flinfo, erase, protect 600 CONFIG_CMD_FPGA FPGA device initialization support 601 CONFIG_CMD_HWFLOW * RTS/CTS hw flow control 602 CONFIG_CMD_I2C * I2C serial bus support 603 CONFIG_CMD_IDE * IDE harddisk support 604 CONFIG_CMD_IMI iminfo 605 CONFIG_CMD_IMLS List all found images 606 CONFIG_CMD_IMMAP * IMMR dump support 607 CONFIG_CMD_IRQ * irqinfo 608 CONFIG_CMD_ITEST Integer/string test of 2 values 609 CONFIG_CMD_JFFS2 * JFFS2 Support 610 CONFIG_CMD_KGDB * kgdb 611 CONFIG_CMD_LOADB loadb 612 CONFIG_CMD_LOADS loads 613 CONFIG_CMD_MEMORY md, mm, nm, mw, cp, cmp, crc, base, 614 loop, loopw, mtest 615 CONFIG_CMD_MISC Misc functions like sleep etc 616 CONFIG_CMD_MMC * MMC memory mapped support 617 CONFIG_CMD_MII * MII utility commands 618 CONFIG_CMD_NAND * NAND support 619 CONFIG_CMD_NET bootp, tftpboot, rarpboot 620 CONFIG_CMD_PCI * pciinfo 621 CONFIG_CMD_PCMCIA * PCMCIA support 622 CONFIG_CMD_PING * send ICMP ECHO_REQUEST to network 623 host 624 CONFIG_CMD_PORTIO * Port I/O 625 CONFIG_CMD_REGINFO * Register dump 626 CONFIG_CMD_RUN run command in env variable 627 CONFIG_CMD_SAVES * save S record dump 628 CONFIG_CMD_SCSI * SCSI Support 629 CONFIG_CMD_SDRAM * print SDRAM configuration information 630 (requires CONFIG_CMD_I2C) 631 CONFIG_CMD_SETGETDCR Support for DCR Register access 632 (4xx only) 633 CONFIG_CMD_SPI * SPI serial bus support 634 CONFIG_CMD_USB * USB support 635 CONFIG_CMD_VFD * VFD support (TRAB) 636 CONFIG_CMD_BSP * Board SPecific functions 637 CONFIG_CMD_CDP * Cisco Discover Protocol support 638 CONFIG_CMD_FSL * Microblaze FSL support 639 640 641 EXAMPLE: If you want all functions except of network 642 support you can write: 643 644 #include "config_cmd_all.h" 645 #undef CONFIG_CMD_NET 646 647 Other Commands: 648 fdt (flattened device tree) command: CONFIG_OF_LIBFDT 649 650 Note: Don't enable the "icache" and "dcache" commands 651 (configuration option CONFIG_CMD_CACHE) unless you know 652 what you (and your U-Boot users) are doing. Data 653 cache cannot be enabled on systems like the 8xx or 654 8260 (where accesses to the IMMR region must be 655 uncached), and it cannot be disabled on all other 656 systems where we (mis-) use the data cache to hold an 657 initial stack and some data. 658 659 660 XXX - this list needs to get updated! 661 662- Watchdog: 663 CONFIG_WATCHDOG 664 If this variable is defined, it enables watchdog 665 support. There must be support in the platform specific 666 code for a watchdog. For the 8xx and 8260 CPUs, the 667 SIU Watchdog feature is enabled in the SYPCR 668 register. 669 670- U-Boot Version: 671 CONFIG_VERSION_VARIABLE 672 If this variable is defined, an environment variable 673 named "ver" is created by U-Boot showing the U-Boot 674 version as printed by the "version" command. 675 This variable is readonly. 676 677- Real-Time Clock: 678 679 When CONFIG_CMD_DATE is selected, the type of the RTC 680 has to be selected, too. Define exactly one of the 681 following options: 682 683 CONFIG_RTC_MPC8xx - use internal RTC of MPC8xx 684 CONFIG_RTC_PCF8563 - use Philips PCF8563 RTC 685 CONFIG_RTC_MC146818 - use MC146818 RTC 686 CONFIG_RTC_DS1307 - use Maxim, Inc. DS1307 RTC 687 CONFIG_RTC_DS1337 - use Maxim, Inc. DS1337 RTC 688 CONFIG_RTC_DS1338 - use Maxim, Inc. DS1338 RTC 689 CONFIG_RTC_DS164x - use Dallas DS164x RTC 690 CONFIG_RTC_ISL1208 - use Intersil ISL1208 RTC 691 CONFIG_RTC_MAX6900 - use Maxim, Inc. MAX6900 RTC 692 693 Note that if the RTC uses I2C, then the I2C interface 694 must also be configured. See I2C Support, below. 695 696- Timestamp Support: 697 698 When CONFIG_TIMESTAMP is selected, the timestamp 699 (date and time) of an image is printed by image 700 commands like bootm or iminfo. This option is 701 automatically enabled when you select CONFIG_CMD_DATE . 702 703- Partition Support: 704 CONFIG_MAC_PARTITION and/or CONFIG_DOS_PARTITION 705 and/or CONFIG_ISO_PARTITION 706 707 If IDE or SCSI support is enabled (CONFIG_CMD_IDE or 708 CONFIG_CMD_SCSI) you must configure support for at 709 least one partition type as well. 710 711- IDE Reset method: 712 CONFIG_IDE_RESET_ROUTINE - this is defined in several 713 board configurations files but used nowhere! 714 715 CONFIG_IDE_RESET - is this is defined, IDE Reset will 716 be performed by calling the function 717 ide_set_reset(int reset) 718 which has to be defined in a board specific file 719 720- ATAPI Support: 721 CONFIG_ATAPI 722 723 Set this to enable ATAPI support. 724 725- LBA48 Support 726 CONFIG_LBA48 727 728 Set this to enable support for disks larger than 137GB 729 Also look at CFG_64BIT_LBA ,CFG_64BIT_VSPRINTF and CFG_64BIT_STRTOUL 730 Whithout these , LBA48 support uses 32bit variables and will 'only' 731 support disks up to 2.1TB. 732 733 CFG_64BIT_LBA: 734 When enabled, makes the IDE subsystem use 64bit sector addresses. 735 Default is 32bit. 736 737- SCSI Support: 738 At the moment only there is only support for the 739 SYM53C8XX SCSI controller; define 740 CONFIG_SCSI_SYM53C8XX to enable it. 741 742 CFG_SCSI_MAX_LUN [8], CFG_SCSI_MAX_SCSI_ID [7] and 743 CFG_SCSI_MAX_DEVICE [CFG_SCSI_MAX_SCSI_ID * 744 CFG_SCSI_MAX_LUN] can be adjusted to define the 745 maximum numbers of LUNs, SCSI ID's and target 746 devices. 747 CFG_SCSI_SYM53C8XX_CCF to fix clock timing (80Mhz) 748 749- NETWORK Support (PCI): 750 CONFIG_E1000 751 Support for Intel 8254x gigabit chips. 752 753 CONFIG_EEPRO100 754 Support for Intel 82557/82559/82559ER chips. 755 Optional CONFIG_EEPRO100_SROM_WRITE enables eeprom 756 write routine for first time initialisation. 757 758 CONFIG_TULIP 759 Support for Digital 2114x chips. 760 Optional CONFIG_TULIP_SELECT_MEDIA for board specific 761 modem chip initialisation (KS8761/QS6611). 762 763 CONFIG_NATSEMI 764 Support for National dp83815 chips. 765 766 CONFIG_NS8382X 767 Support for National dp8382[01] gigabit chips. 768 769- NETWORK Support (other): 770 771 CONFIG_DRIVER_LAN91C96 772 Support for SMSC's LAN91C96 chips. 773 774 CONFIG_LAN91C96_BASE 775 Define this to hold the physical address 776 of the LAN91C96's I/O space 777 778 CONFIG_LAN91C96_USE_32_BIT 779 Define this to enable 32 bit addressing 780 781 CONFIG_DRIVER_SMC91111 782 Support for SMSC's LAN91C111 chip 783 784 CONFIG_SMC91111_BASE 785 Define this to hold the physical address 786 of the device (I/O space) 787 788 CONFIG_SMC_USE_32_BIT 789 Define this if data bus is 32 bits 790 791 CONFIG_SMC_USE_IOFUNCS 792 Define this to use i/o functions instead of macros 793 (some hardware wont work with macros) 794 795- USB Support: 796 At the moment only the UHCI host controller is 797 supported (PIP405, MIP405, MPC5200); define 798 CONFIG_USB_UHCI to enable it. 799 define CONFIG_USB_KEYBOARD to enable the USB Keyboard 800 and define CONFIG_USB_STORAGE to enable the USB 801 storage devices. 802 Note: 803 Supported are USB Keyboards and USB Floppy drives 804 (TEAC FD-05PUB). 805 MPC5200 USB requires additional defines: 806 CONFIG_USB_CLOCK 807 for 528 MHz Clock: 0x0001bbbb 808 CONFIG_USB_CONFIG 809 for differential drivers: 0x00001000 810 for single ended drivers: 0x00005000 811 CFG_USB_EVENT_POLL 812 May be defined to allow interrupt polling 813 instead of using asynchronous interrupts 814 815- USB Device: 816 Define the below if you wish to use the USB console. 817 Once firmware is rebuilt from a serial console issue the 818 command "setenv stdin usbtty; setenv stdout usbtty" and 819 attach your usb cable. The Unix command "dmesg" should print 820 it has found a new device. The environment variable usbtty 821 can be set to gserial or cdc_acm to enable your device to 822 appear to a USB host as a Linux gserial device or a 823 Common Device Class Abstract Control Model serial device. 824 If you select usbtty = gserial you should be able to enumerate 825 a Linux host by 826 # modprobe usbserial vendor=0xVendorID product=0xProductID 827 else if using cdc_acm, simply setting the environment 828 variable usbtty to be cdc_acm should suffice. The following 829 might be defined in YourBoardName.h 830 831 CONFIG_USB_DEVICE 832 Define this to build a UDC device 833 834 CONFIG_USB_TTY 835 Define this to have a tty type of device available to 836 talk to the UDC device 837 838 CFG_CONSOLE_IS_IN_ENV 839 Define this if you want stdin, stdout &/or stderr to 840 be set to usbtty. 841 842 mpc8xx: 843 CFG_USB_EXTC_CLK 0xBLAH 844 Derive USB clock from external clock "blah" 845 - CFG_USB_EXTC_CLK 0x02 846 847 CFG_USB_BRG_CLK 0xBLAH 848 Derive USB clock from brgclk 849 - CFG_USB_BRG_CLK 0x04 850 851 If you have a USB-IF assigned VendorID then you may wish to 852 define your own vendor specific values either in BoardName.h 853 or directly in usbd_vendor_info.h. If you don't define 854 CONFIG_USBD_MANUFACTURER, CONFIG_USBD_PRODUCT_NAME, 855 CONFIG_USBD_VENDORID and CONFIG_USBD_PRODUCTID, then U-Boot 856 should pretend to be a Linux device to it's target host. 857 858 CONFIG_USBD_MANUFACTURER 859 Define this string as the name of your company for 860 - CONFIG_USBD_MANUFACTURER "my company" 861 862 CONFIG_USBD_PRODUCT_NAME 863 Define this string as the name of your product 864 - CONFIG_USBD_PRODUCT_NAME "acme usb device" 865 866 CONFIG_USBD_VENDORID 867 Define this as your assigned Vendor ID from the USB 868 Implementors Forum. This *must* be a genuine Vendor ID 869 to avoid polluting the USB namespace. 870 - CONFIG_USBD_VENDORID 0xFFFF 871 872 CONFIG_USBD_PRODUCTID 873 Define this as the unique Product ID 874 for your device 875 - CONFIG_USBD_PRODUCTID 0xFFFF 876 877 878- MMC Support: 879 The MMC controller on the Intel PXA is supported. To 880 enable this define CONFIG_MMC. The MMC can be 881 accessed from the boot prompt by mapping the device 882 to physical memory similar to flash. Command line is 883 enabled with CONFIG_CMD_MMC. The MMC driver also works with 884 the FAT fs. This is enabled with CONFIG_CMD_FAT. 885 886- Journaling Flash filesystem support: 887 CONFIG_JFFS2_NAND, CONFIG_JFFS2_NAND_OFF, CONFIG_JFFS2_NAND_SIZE, 888 CONFIG_JFFS2_NAND_DEV 889 Define these for a default partition on a NAND device 890 891 CFG_JFFS2_FIRST_SECTOR, 892 CFG_JFFS2_FIRST_BANK, CFG_JFFS2_NUM_BANKS 893 Define these for a default partition on a NOR device 894 895 CFG_JFFS_CUSTOM_PART 896 Define this to create an own partition. You have to provide a 897 function struct part_info* jffs2_part_info(int part_num) 898 899 If you define only one JFFS2 partition you may also want to 900 #define CFG_JFFS_SINGLE_PART 1 901 to disable the command chpart. This is the default when you 902 have not defined a custom partition 903 904- Keyboard Support: 905 CONFIG_ISA_KEYBOARD 906 907 Define this to enable standard (PC-Style) keyboard 908 support 909 910 CONFIG_I8042_KBD 911 Standard PC keyboard driver with US (is default) and 912 GERMAN key layout (switch via environment 'keymap=de') support. 913 Export function i8042_kbd_init, i8042_tstc and i8042_getc 914 for cfb_console. Supports cursor blinking. 915 916- Video support: 917 CONFIG_VIDEO 918 919 Define this to enable video support (for output to 920 video). 921 922 CONFIG_VIDEO_CT69000 923 924 Enable Chips & Technologies 69000 Video chip 925 926 CONFIG_VIDEO_SMI_LYNXEM 927 Enable Silicon Motion SMI 712/710/810 Video chip. The 928 video output is selected via environment 'videoout' 929 (1 = LCD and 2 = CRT). If videoout is undefined, CRT is 930 assumed. 931 932 For the CT69000 and SMI_LYNXEM drivers, videomode is 933 selected via environment 'videomode'. Two diferent ways 934 are possible: 935 - "videomode=num" 'num' is a standard LiLo mode numbers. 936 Following standard modes are supported (* is default): 937 938 Colors 640x480 800x600 1024x768 1152x864 1280x1024 939 -------------+--------------------------------------------- 940 8 bits | 0x301* 0x303 0x305 0x161 0x307 941 15 bits | 0x310 0x313 0x316 0x162 0x319 942 16 bits | 0x311 0x314 0x317 0x163 0x31A 943 24 bits | 0x312 0x315 0x318 ? 0x31B 944 -------------+--------------------------------------------- 945 (i.e. setenv videomode 317; saveenv; reset;) 946 947 - "videomode=bootargs" all the video parameters are parsed 948 from the bootargs. (See drivers/video/videomodes.c) 949 950 951 CONFIG_VIDEO_SED13806 952 Enable Epson SED13806 driver. This driver supports 8bpp 953 and 16bpp modes defined by CONFIG_VIDEO_SED13806_8BPP 954 or CONFIG_VIDEO_SED13806_16BPP 955 956- Keyboard Support: 957 CONFIG_KEYBOARD 958 959 Define this to enable a custom keyboard support. 960 This simply calls drv_keyboard_init() which must be 961 defined in your board-specific files. 962 The only board using this so far is RBC823. 963 964- LCD Support: CONFIG_LCD 965 966 Define this to enable LCD support (for output to LCD 967 display); also select one of the supported displays 968 by defining one of these: 969 970 CONFIG_NEC_NL6448AC33: 971 972 NEC NL6448AC33-18. Active, color, single scan. 973 974 CONFIG_NEC_NL6448BC20 975 976 NEC NL6448BC20-08. 6.5", 640x480. 977 Active, color, single scan. 978 979 CONFIG_NEC_NL6448BC33_54 980 981 NEC NL6448BC33-54. 10.4", 640x480. 982 Active, color, single scan. 983 984 CONFIG_SHARP_16x9 985 986 Sharp 320x240. Active, color, single scan. 987 It isn't 16x9, and I am not sure what it is. 988 989 CONFIG_SHARP_LQ64D341 990 991 Sharp LQ64D341 display, 640x480. 992 Active, color, single scan. 993 994 CONFIG_HLD1045 995 996 HLD1045 display, 640x480. 997 Active, color, single scan. 998 999 CONFIG_OPTREX_BW 1000 1001 Optrex CBL50840-2 NF-FW 99 22 M5 1002 or 1003 Hitachi LMG6912RPFC-00T 1004 or 1005 Hitachi SP14Q002 1006 1007 320x240. Black & white. 1008 1009 Normally display is black on white background; define 1010 CFG_WHITE_ON_BLACK to get it inverted. 1011 1012- Splash Screen Support: CONFIG_SPLASH_SCREEN 1013 1014 If this option is set, the environment is checked for 1015 a variable "splashimage". If found, the usual display 1016 of logo, copyright and system information on the LCD 1017 is suppressed and the BMP image at the address 1018 specified in "splashimage" is loaded instead. The 1019 console is redirected to the "nulldev", too. This 1020 allows for a "silent" boot where a splash screen is 1021 loaded very quickly after power-on. 1022 1023- Gzip compressed BMP image support: CONFIG_VIDEO_BMP_GZIP 1024 1025 If this option is set, additionally to standard BMP 1026 images, gzipped BMP images can be displayed via the 1027 splashscreen support or the bmp command. 1028 1029- Compression support: 1030 CONFIG_BZIP2 1031 1032 If this option is set, support for bzip2 compressed 1033 images is included. If not, only uncompressed and gzip 1034 compressed images are supported. 1035 1036 NOTE: the bzip2 algorithm requires a lot of RAM, so 1037 the malloc area (as defined by CFG_MALLOC_LEN) should 1038 be at least 4MB. 1039 1040- MII/PHY support: 1041 CONFIG_PHY_ADDR 1042 1043 The address of PHY on MII bus. 1044 1045 CONFIG_PHY_CLOCK_FREQ (ppc4xx) 1046 1047 The clock frequency of the MII bus 1048 1049 CONFIG_PHY_GIGE 1050 1051 If this option is set, support for speed/duplex 1052 detection of Gigabit PHY is included. 1053 1054 CONFIG_PHY_RESET_DELAY 1055 1056 Some PHY like Intel LXT971A need extra delay after 1057 reset before any MII register access is possible. 1058 For such PHY, set this option to the usec delay 1059 required. (minimum 300usec for LXT971A) 1060 1061 CONFIG_PHY_CMD_DELAY (ppc4xx) 1062 1063 Some PHY like Intel LXT971A need extra delay after 1064 command issued before MII status register can be read 1065 1066- Ethernet address: 1067 CONFIG_ETHADDR 1068 CONFIG_ETH2ADDR 1069 CONFIG_ETH3ADDR 1070 1071 Define a default value for ethernet address to use 1072 for the respective ethernet interface, in case this 1073 is not determined automatically. 1074 1075- IP address: 1076 CONFIG_IPADDR 1077 1078 Define a default value for the IP address to use for 1079 the default ethernet interface, in case this is not 1080 determined through e.g. bootp. 1081 1082- Server IP address: 1083 CONFIG_SERVERIP 1084 1085 Defines a default value for theIP address of a TFTP 1086 server to contact when using the "tftboot" command. 1087 1088- Multicast TFTP Mode: 1089 CONFIG_MCAST_TFTP 1090 1091 Defines whether you want to support multicast TFTP as per 1092 rfc-2090; for example to work with atftp. Lets lots of targets 1093 tftp down the same boot image concurrently. Note: the ethernet 1094 driver in use must provide a function: mcast() to join/leave a 1095 multicast group. 1096 1097 CONFIG_BOOTP_RANDOM_DELAY 1098- BOOTP Recovery Mode: 1099 CONFIG_BOOTP_RANDOM_DELAY 1100 1101 If you have many targets in a network that try to 1102 boot using BOOTP, you may want to avoid that all 1103 systems send out BOOTP requests at precisely the same 1104 moment (which would happen for instance at recovery 1105 from a power failure, when all systems will try to 1106 boot, thus flooding the BOOTP server. Defining 1107 CONFIG_BOOTP_RANDOM_DELAY causes a random delay to be 1108 inserted before sending out BOOTP requests. The 1109 following delays are inserted then: 1110 1111 1st BOOTP request: delay 0 ... 1 sec 1112 2nd BOOTP request: delay 0 ... 2 sec 1113 3rd BOOTP request: delay 0 ... 4 sec 1114 4th and following 1115 BOOTP requests: delay 0 ... 8 sec 1116 1117- DHCP Advanced Options: 1118 You can fine tune the DHCP functionality by defining 1119 CONFIG_BOOTP_* symbols: 1120 1121 CONFIG_BOOTP_SUBNETMASK 1122 CONFIG_BOOTP_GATEWAY 1123 CONFIG_BOOTP_HOSTNAME 1124 CONFIG_BOOTP_NISDOMAIN 1125 CONFIG_BOOTP_BOOTPATH 1126 CONFIG_BOOTP_BOOTFILESIZE 1127 CONFIG_BOOTP_DNS 1128 CONFIG_BOOTP_DNS2 1129 CONFIG_BOOTP_SEND_HOSTNAME 1130 CONFIG_BOOTP_NTPSERVER 1131 CONFIG_BOOTP_TIMEOFFSET 1132 CONFIG_BOOTP_VENDOREX 1133 1134 CONFIG_BOOTP_SERVERIP - TFTP server will be the serverip 1135 environment variable, not the BOOTP server. 1136 1137 CONFIG_BOOTP_DNS2 - If a DHCP client requests the DNS 1138 serverip from a DHCP server, it is possible that more 1139 than one DNS serverip is offered to the client. 1140 If CONFIG_BOOTP_DNS2 is enabled, the secondary DNS 1141 serverip will be stored in the additional environment 1142 variable "dnsip2". The first DNS serverip is always 1143 stored in the variable "dnsip", when CONFIG_BOOTP_DNS 1144 is defined. 1145 1146 CONFIG_BOOTP_SEND_HOSTNAME - Some DHCP servers are capable 1147 to do a dynamic update of a DNS server. To do this, they 1148 need the hostname of the DHCP requester. 1149 If CONFIG_BOOTP_SEND_HOSTNAME is defined, the content 1150 of the "hostname" environment variable is passed as 1151 option 12 to the DHCP server. 1152 1153 - CDP Options: 1154 CONFIG_CDP_DEVICE_ID 1155 1156 The device id used in CDP trigger frames. 1157 1158 CONFIG_CDP_DEVICE_ID_PREFIX 1159 1160 A two character string which is prefixed to the MAC address 1161 of the device. 1162 1163 CONFIG_CDP_PORT_ID 1164 1165 A printf format string which contains the ascii name of 1166 the port. Normally is set to "eth%d" which sets 1167 eth0 for the first ethernet, eth1 for the second etc. 1168 1169 CONFIG_CDP_CAPABILITIES 1170 1171 A 32bit integer which indicates the device capabilities; 1172 0x00000010 for a normal host which does not forwards. 1173 1174 CONFIG_CDP_VERSION 1175 1176 An ascii string containing the version of the software. 1177 1178 CONFIG_CDP_PLATFORM 1179 1180 An ascii string containing the name of the platform. 1181 1182 CONFIG_CDP_TRIGGER 1183 1184 A 32bit integer sent on the trigger. 1185 1186 CONFIG_CDP_POWER_CONSUMPTION 1187 1188 A 16bit integer containing the power consumption of the 1189 device in .1 of milliwatts. 1190 1191 CONFIG_CDP_APPLIANCE_VLAN_TYPE 1192 1193 A byte containing the id of the VLAN. 1194 1195- Status LED: CONFIG_STATUS_LED 1196 1197 Several configurations allow to display the current 1198 status using a LED. For instance, the LED will blink 1199 fast while running U-Boot code, stop blinking as 1200 soon as a reply to a BOOTP request was received, and 1201 start blinking slow once the Linux kernel is running 1202 (supported by a status LED driver in the Linux 1203 kernel). Defining CONFIG_STATUS_LED enables this 1204 feature in U-Boot. 1205 1206- CAN Support: CONFIG_CAN_DRIVER 1207 1208 Defining CONFIG_CAN_DRIVER enables CAN driver support 1209 on those systems that support this (optional) 1210 feature, like the TQM8xxL modules. 1211 1212- I2C Support: CONFIG_HARD_I2C | CONFIG_SOFT_I2C 1213 1214 These enable I2C serial bus commands. Defining either of 1215 (but not both of) CONFIG_HARD_I2C or CONFIG_SOFT_I2C will 1216 include the appropriate I2C driver for the selected cpu. 1217 1218 This will allow you to use i2c commands at the u-boot 1219 command line (as long as you set CONFIG_CMD_I2C in 1220 CONFIG_COMMANDS) and communicate with i2c based realtime 1221 clock chips. See common/cmd_i2c.c for a description of the 1222 command line interface. 1223 1224 CONFIG_I2C_CMD_TREE is a recommended option that places 1225 all I2C commands under a single 'i2c' root command. The 1226 older 'imm', 'imd', 'iprobe' etc. commands are considered 1227 deprecated and may disappear in the future. 1228 1229 CONFIG_HARD_I2C selects a hardware I2C controller. 1230 1231 CONFIG_SOFT_I2C configures u-boot to use a software (aka 1232 bit-banging) driver instead of CPM or similar hardware 1233 support for I2C. 1234 1235 There are several other quantities that must also be 1236 defined when you define CONFIG_HARD_I2C or CONFIG_SOFT_I2C. 1237 1238 In both cases you will need to define CFG_I2C_SPEED 1239 to be the frequency (in Hz) at which you wish your i2c bus 1240 to run and CFG_I2C_SLAVE to be the address of this node (ie 1241 the cpu's i2c node address). 1242 1243 Now, the u-boot i2c code for the mpc8xx (cpu/mpc8xx/i2c.c) 1244 sets the cpu up as a master node and so its address should 1245 therefore be cleared to 0 (See, eg, MPC823e User's Manual 1246 p.16-473). So, set CFG_I2C_SLAVE to 0. 1247 1248 That's all that's required for CONFIG_HARD_I2C. 1249 1250 If you use the software i2c interface (CONFIG_SOFT_I2C) 1251 then the following macros need to be defined (examples are 1252 from include/configs/lwmon.h): 1253 1254 I2C_INIT 1255 1256 (Optional). Any commands necessary to enable the I2C 1257 controller or configure ports. 1258 1259 eg: #define I2C_INIT (immr->im_cpm.cp_pbdir |= PB_SCL) 1260 1261 I2C_PORT 1262 1263 (Only for MPC8260 CPU). The I/O port to use (the code 1264 assumes both bits are on the same port). Valid values 1265 are 0..3 for ports A..D. 1266 1267 I2C_ACTIVE 1268 1269 The code necessary to make the I2C data line active 1270 (driven). If the data line is open collector, this 1271 define can be null. 1272 1273 eg: #define I2C_ACTIVE (immr->im_cpm.cp_pbdir |= PB_SDA) 1274 1275 I2C_TRISTATE 1276 1277 The code necessary to make the I2C data line tri-stated 1278 (inactive). If the data line is open collector, this 1279 define can be null. 1280 1281 eg: #define I2C_TRISTATE (immr->im_cpm.cp_pbdir &= ~PB_SDA) 1282 1283 I2C_READ 1284 1285 Code that returns TRUE if the I2C data line is high, 1286 FALSE if it is low. 1287 1288 eg: #define I2C_READ ((immr->im_cpm.cp_pbdat & PB_SDA) != 0) 1289 1290 I2C_SDA(bit) 1291 1292 If <bit> is TRUE, sets the I2C data line high. If it 1293 is FALSE, it clears it (low). 1294 1295 eg: #define I2C_SDA(bit) \ 1296 if(bit) immr->im_cpm.cp_pbdat |= PB_SDA; \ 1297 else immr->im_cpm.cp_pbdat &= ~PB_SDA 1298 1299 I2C_SCL(bit) 1300 1301 If <bit> is TRUE, sets the I2C clock line high. If it 1302 is FALSE, it clears it (low). 1303 1304 eg: #define I2C_SCL(bit) \ 1305 if(bit) immr->im_cpm.cp_pbdat |= PB_SCL; \ 1306 else immr->im_cpm.cp_pbdat &= ~PB_SCL 1307 1308 I2C_DELAY 1309 1310 This delay is invoked four times per clock cycle so this 1311 controls the rate of data transfer. The data rate thus 1312 is 1 / (I2C_DELAY * 4). Often defined to be something 1313 like: 1314 1315 #define I2C_DELAY udelay(2) 1316 1317 CFG_I2C_INIT_BOARD 1318 1319 When a board is reset during an i2c bus transfer 1320 chips might think that the current transfer is still 1321 in progress. On some boards it is possible to access 1322 the i2c SCLK line directly, either by using the 1323 processor pin as a GPIO or by having a second pin 1324 connected to the bus. If this option is defined a 1325 custom i2c_init_board() routine in boards/xxx/board.c 1326 is run early in the boot sequence. 1327 1328 CONFIG_I2CFAST (PPC405GP|PPC405EP only) 1329 1330 This option enables configuration of bi_iic_fast[] flags 1331 in u-boot bd_info structure based on u-boot environment 1332 variable "i2cfast". (see also i2cfast) 1333 1334 CONFIG_I2C_MULTI_BUS 1335 1336 This option allows the use of multiple I2C buses, each of which 1337 must have a controller. At any point in time, only one bus is 1338 active. To switch to a different bus, use the 'i2c dev' command. 1339 Note that bus numbering is zero-based. 1340 1341 CFG_I2C_NOPROBES 1342 1343 This option specifies a list of I2C devices that will be skipped 1344 when the 'i2c probe' command is issued (or 'iprobe' using the legacy 1345 command). If CONFIG_I2C_MULTI_BUS is set, specify a list of bus-device 1346 pairs. Otherwise, specify a 1D array of device addresses 1347 1348 e.g. 1349 #undef CONFIG_I2C_MULTI_BUS 1350 #define CFG_I2C_NOPROBES {0x50,0x68} 1351 1352 will skip addresses 0x50 and 0x68 on a board with one I2C bus 1353 1354 #define CONFIG_I2C_MULTI_BUS 1355 #define CFG_I2C_MULTI_NOPROBES {{0,0x50},{0,0x68},{1,0x54}} 1356 1357 will skip addresses 0x50 and 0x68 on bus 0 and address 0x54 on bus 1 1358 1359 CFG_SPD_BUS_NUM 1360 1361 If defined, then this indicates the I2C bus number for DDR SPD. 1362 If not defined, then U-Boot assumes that SPD is on I2C bus 0. 1363 1364 CFG_RTC_BUS_NUM 1365 1366 If defined, then this indicates the I2C bus number for the RTC. 1367 If not defined, then U-Boot assumes that RTC is on I2C bus 0. 1368 1369 CFG_DTT_BUS_NUM 1370 1371 If defined, then this indicates the I2C bus number for the DTT. 1372 If not defined, then U-Boot assumes that DTT is on I2C bus 0. 1373 1374 CONFIG_FSL_I2C 1375 1376 Define this option if you want to use Freescale's I2C driver in 1377 drivers/i2c/fsl_i2c.c. 1378 1379 1380- SPI Support: CONFIG_SPI 1381 1382 Enables SPI driver (so far only tested with 1383 SPI EEPROM, also an instance works with Crystal A/D and 1384 D/As on the SACSng board) 1385 1386 CONFIG_SPI_X 1387 1388 Enables extended (16-bit) SPI EEPROM addressing. 1389 (symmetrical to CONFIG_I2C_X) 1390 1391 CONFIG_SOFT_SPI 1392 1393 Enables a software (bit-bang) SPI driver rather than 1394 using hardware support. This is a general purpose 1395 driver that only requires three general I/O port pins 1396 (two outputs, one input) to function. If this is 1397 defined, the board configuration must define several 1398 SPI configuration items (port pins to use, etc). For 1399 an example, see include/configs/sacsng.h. 1400 1401 CONFIG_HARD_SPI 1402 1403 Enables a hardware SPI driver for general-purpose reads 1404 and writes. As with CONFIG_SOFT_SPI, the board configuration 1405 must define a list of chip-select function pointers. 1406 Currently supported on some MPC8xxx processors. For an 1407 example, see include/configs/mpc8349emds.h. 1408 1409- FPGA Support: CONFIG_FPGA 1410 1411 Enables FPGA subsystem. 1412 1413 CONFIG_FPGA_<vendor> 1414 1415 Enables support for specific chip vendors. 1416 (ALTERA, XILINX) 1417 1418 CONFIG_FPGA_<family> 1419 1420 Enables support for FPGA family. 1421 (SPARTAN2, SPARTAN3, VIRTEX2, CYCLONE2, ACEX1K, ACEX) 1422 1423 CONFIG_FPGA_COUNT 1424 1425 Specify the number of FPGA devices to support. 1426 1427 CFG_FPGA_PROG_FEEDBACK 1428 1429 Enable printing of hash marks during FPGA configuration. 1430 1431 CFG_FPGA_CHECK_BUSY 1432 1433 Enable checks on FPGA configuration interface busy 1434 status by the configuration function. This option 1435 will require a board or device specific function to 1436 be written. 1437 1438 CONFIG_FPGA_DELAY 1439 1440 If defined, a function that provides delays in the FPGA 1441 configuration driver. 1442 1443 CFG_FPGA_CHECK_CTRLC 1444 Allow Control-C to interrupt FPGA configuration 1445 1446 CFG_FPGA_CHECK_ERROR 1447 1448 Check for configuration errors during FPGA bitfile 1449 loading. For example, abort during Virtex II 1450 configuration if the INIT_B line goes low (which 1451 indicated a CRC error). 1452 1453 CFG_FPGA_WAIT_INIT 1454 1455 Maximum time to wait for the INIT_B line to deassert 1456 after PROB_B has been deasserted during a Virtex II 1457 FPGA configuration sequence. The default time is 500 1458 mS. 1459 1460 CFG_FPGA_WAIT_BUSY 1461 1462 Maximum time to wait for BUSY to deassert during 1463 Virtex II FPGA configuration. The default is 5 mS. 1464 1465 CFG_FPGA_WAIT_CONFIG 1466 1467 Time to wait after FPGA configuration. The default is 1468 200 mS. 1469 1470- Configuration Management: 1471 CONFIG_IDENT_STRING 1472 1473 If defined, this string will be added to the U-Boot 1474 version information (U_BOOT_VERSION) 1475 1476- Vendor Parameter Protection: 1477 1478 U-Boot considers the values of the environment 1479 variables "serial#" (Board Serial Number) and 1480 "ethaddr" (Ethernet Address) to be parameters that 1481 are set once by the board vendor / manufacturer, and 1482 protects these variables from casual modification by 1483 the user. Once set, these variables are read-only, 1484 and write or delete attempts are rejected. You can 1485 change this behviour: 1486 1487 If CONFIG_ENV_OVERWRITE is #defined in your config 1488 file, the write protection for vendor parameters is 1489 completely disabled. Anybody can change or delete 1490 these parameters. 1491 1492 Alternatively, if you #define _both_ CONFIG_ETHADDR 1493 _and_ CONFIG_OVERWRITE_ETHADDR_ONCE, a default 1494 ethernet address is installed in the environment, 1495 which can be changed exactly ONCE by the user. [The 1496 serial# is unaffected by this, i. e. it remains 1497 read-only.] 1498 1499- Protected RAM: 1500 CONFIG_PRAM 1501 1502 Define this variable to enable the reservation of 1503 "protected RAM", i. e. RAM which is not overwritten 1504 by U-Boot. Define CONFIG_PRAM to hold the number of 1505 kB you want to reserve for pRAM. You can overwrite 1506 this default value by defining an environment 1507 variable "pram" to the number of kB you want to 1508 reserve. Note that the board info structure will 1509 still show the full amount of RAM. If pRAM is 1510 reserved, a new environment variable "mem" will 1511 automatically be defined to hold the amount of 1512 remaining RAM in a form that can be passed as boot 1513 argument to Linux, for instance like that: 1514 1515 setenv bootargs ... mem=\${mem} 1516 saveenv 1517 1518 This way you can tell Linux not to use this memory, 1519 either, which results in a memory region that will 1520 not be affected by reboots. 1521 1522 *WARNING* If your board configuration uses automatic 1523 detection of the RAM size, you must make sure that 1524 this memory test is non-destructive. So far, the 1525 following board configurations are known to be 1526 "pRAM-clean": 1527 1528 ETX094, IVMS8, IVML24, SPD8xx, TQM8xxL, 1529 HERMES, IP860, RPXlite, LWMON, LANTEC, 1530 PCU_E, FLAGADM, TQM8260 1531 1532- Error Recovery: 1533 CONFIG_PANIC_HANG 1534 1535 Define this variable to stop the system in case of a 1536 fatal error, so that you have to reset it manually. 1537 This is probably NOT a good idea for an embedded 1538 system where you want to system to reboot 1539 automatically as fast as possible, but it may be 1540 useful during development since you can try to debug 1541 the conditions that lead to the situation. 1542 1543 CONFIG_NET_RETRY_COUNT 1544 1545 This variable defines the number of retries for 1546 network operations like ARP, RARP, TFTP, or BOOTP 1547 before giving up the operation. If not defined, a 1548 default value of 5 is used. 1549 1550- Command Interpreter: 1551 CONFIG_AUTO_COMPLETE 1552 1553 Enable auto completion of commands using TAB. 1554 1555 Note that this feature has NOT been implemented yet 1556 for the "hush" shell. 1557 1558 1559 CFG_HUSH_PARSER 1560 1561 Define this variable to enable the "hush" shell (from 1562 Busybox) as command line interpreter, thus enabling 1563 powerful command line syntax like 1564 if...then...else...fi conditionals or `&&' and '||' 1565 constructs ("shell scripts"). 1566 1567 If undefined, you get the old, much simpler behaviour 1568 with a somewhat smaller memory footprint. 1569 1570 1571 CFG_PROMPT_HUSH_PS2 1572 1573 This defines the secondary prompt string, which is 1574 printed when the command interpreter needs more input 1575 to complete a command. Usually "> ". 1576 1577 Note: 1578 1579 In the current implementation, the local variables 1580 space and global environment variables space are 1581 separated. Local variables are those you define by 1582 simply typing `name=value'. To access a local 1583 variable later on, you have write `$name' or 1584 `${name}'; to execute the contents of a variable 1585 directly type `$name' at the command prompt. 1586 1587 Global environment variables are those you use 1588 setenv/printenv to work with. To run a command stored 1589 in such a variable, you need to use the run command, 1590 and you must not use the '$' sign to access them. 1591 1592 To store commands and special characters in a 1593 variable, please use double quotation marks 1594 surrounding the whole text of the variable, instead 1595 of the backslashes before semicolons and special 1596 symbols. 1597 1598- Commandline Editing and History: 1599 CONFIG_CMDLINE_EDITING 1600 1601 Enable editiong and History functions for interactive 1602 commandline input operations 1603 1604- Default Environment: 1605 CONFIG_EXTRA_ENV_SETTINGS 1606 1607 Define this to contain any number of null terminated 1608 strings (variable = value pairs) that will be part of 1609 the default environment compiled into the boot image. 1610 1611 For example, place something like this in your 1612 board's config file: 1613 1614 #define CONFIG_EXTRA_ENV_SETTINGS \ 1615 "myvar1=value1\0" \ 1616 "myvar2=value2\0" 1617 1618 Warning: This method is based on knowledge about the 1619 internal format how the environment is stored by the 1620 U-Boot code. This is NOT an official, exported 1621 interface! Although it is unlikely that this format 1622 will change soon, there is no guarantee either. 1623 You better know what you are doing here. 1624 1625 Note: overly (ab)use of the default environment is 1626 discouraged. Make sure to check other ways to preset 1627 the environment like the autoscript function or the 1628 boot command first. 1629 1630- DataFlash Support: 1631 CONFIG_HAS_DATAFLASH 1632 1633 Defining this option enables DataFlash features and 1634 allows to read/write in Dataflash via the standard 1635 commands cp, md... 1636 1637- SystemACE Support: 1638 CONFIG_SYSTEMACE 1639 1640 Adding this option adds support for Xilinx SystemACE 1641 chips attached via some sort of local bus. The address 1642 of the chip must alsh be defined in the 1643 CFG_SYSTEMACE_BASE macro. For example: 1644 1645 #define CONFIG_SYSTEMACE 1646 #define CFG_SYSTEMACE_BASE 0xf0000000 1647 1648 When SystemACE support is added, the "ace" device type 1649 becomes available to the fat commands, i.e. fatls. 1650 1651- TFTP Fixed UDP Port: 1652 CONFIG_TFTP_PORT 1653 1654 If this is defined, the environment variable tftpsrcp 1655 is used to supply the TFTP UDP source port value. 1656 If tftpsrcp isn't defined, the normal pseudo-random port 1657 number generator is used. 1658 1659 Also, the environment variable tftpdstp is used to supply 1660 the TFTP UDP destination port value. If tftpdstp isn't 1661 defined, the normal port 69 is used. 1662 1663 The purpose for tftpsrcp is to allow a TFTP server to 1664 blindly start the TFTP transfer using the pre-configured 1665 target IP address and UDP port. This has the effect of 1666 "punching through" the (Windows XP) firewall, allowing 1667 the remainder of the TFTP transfer to proceed normally. 1668 A better solution is to properly configure the firewall, 1669 but sometimes that is not allowed. 1670 1671- Show boot progress: 1672 CONFIG_SHOW_BOOT_PROGRESS 1673 1674 Defining this option allows to add some board- 1675 specific code (calling a user-provided function 1676 "show_boot_progress(int)") that enables you to show 1677 the system's boot progress on some display (for 1678 example, some LED's) on your board. At the moment, 1679 the following checkpoints are implemented: 1680 1681Legacy uImage format: 1682 1683 Arg Where When 1684 1 common/cmd_bootm.c before attempting to boot an image 1685 -1 common/cmd_bootm.c Image header has bad magic number 1686 2 common/cmd_bootm.c Image header has correct magic number 1687 -2 common/cmd_bootm.c Image header has bad checksum 1688 3 common/cmd_bootm.c Image header has correct checksum 1689 -3 common/cmd_bootm.c Image data has bad checksum 1690 4 common/cmd_bootm.c Image data has correct checksum 1691 -4 common/cmd_bootm.c Image is for unsupported architecture 1692 5 common/cmd_bootm.c Architecture check OK 1693 -5 common/cmd_bootm.c Wrong Image Type (not kernel, multi) 1694 6 common/cmd_bootm.c Image Type check OK 1695 -6 common/cmd_bootm.c gunzip uncompression error 1696 -7 common/cmd_bootm.c Unimplemented compression type 1697 7 common/cmd_bootm.c Uncompression OK 1698 8 common/cmd_bootm.c No uncompress/copy overwrite error 1699 -9 common/cmd_bootm.c Unsupported OS (not Linux, BSD, VxWorks, QNX) 1700 1701 9 common/image.c Start initial ramdisk verification 1702 -10 common/image.c Ramdisk header has bad magic number 1703 -11 common/image.c Ramdisk header has bad checksum 1704 10 common/image.c Ramdisk header is OK 1705 -12 common/image.c Ramdisk data has bad checksum 1706 11 common/image.c Ramdisk data has correct checksum 1707 12 common/image.c Ramdisk verification complete, start loading 1708 -13 common/image.c Wrong Image Type (not PPC Linux Ramdisk) 1709 13 common/image.c Start multifile image verification 1710 14 common/image.c No initial ramdisk, no multifile, continue. 1711 1712 15 lib_<arch>/bootm.c All preparation done, transferring control to OS 1713 1714 -30 lib_ppc/board.c Fatal error, hang the system 1715 -31 post/post.c POST test failed, detected by post_output_backlog() 1716 -32 post/post.c POST test failed, detected by post_run_single() 1717 1718 34 common/cmd_doc.c before loading a Image from a DOC device 1719 -35 common/cmd_doc.c Bad usage of "doc" command 1720 35 common/cmd_doc.c correct usage of "doc" command 1721 -36 common/cmd_doc.c No boot device 1722 36 common/cmd_doc.c correct boot device 1723 -37 common/cmd_doc.c Unknown Chip ID on boot device 1724 37 common/cmd_doc.c correct chip ID found, device available 1725 -38 common/cmd_doc.c Read Error on boot device 1726 38 common/cmd_doc.c reading Image header from DOC device OK 1727 -39 common/cmd_doc.c Image header has bad magic number 1728 39 common/cmd_doc.c Image header has correct magic number 1729 -40 common/cmd_doc.c Error reading Image from DOC device 1730 40 common/cmd_doc.c Image header has correct magic number 1731 41 common/cmd_ide.c before loading a Image from a IDE device 1732 -42 common/cmd_ide.c Bad usage of "ide" command 1733 42 common/cmd_ide.c correct usage of "ide" command 1734 -43 common/cmd_ide.c No boot device 1735 43 common/cmd_ide.c boot device found 1736 -44 common/cmd_ide.c Device not available 1737 44 common/cmd_ide.c Device available 1738 -45 common/cmd_ide.c wrong partition selected 1739 45 common/cmd_ide.c partition selected 1740 -46 common/cmd_ide.c Unknown partition table 1741 46 common/cmd_ide.c valid partition table found 1742 -47 common/cmd_ide.c Invalid partition type 1743 47 common/cmd_ide.c correct partition type 1744 -48 common/cmd_ide.c Error reading Image Header on boot device 1745 48 common/cmd_ide.c reading Image Header from IDE device OK 1746 -49 common/cmd_ide.c Image header has bad magic number 1747 49 common/cmd_ide.c Image header has correct magic number 1748 -50 common/cmd_ide.c Image header has bad checksum 1749 50 common/cmd_ide.c Image header has correct checksum 1750 -51 common/cmd_ide.c Error reading Image from IDE device 1751 51 common/cmd_ide.c reading Image from IDE device OK 1752 52 common/cmd_nand.c before loading a Image from a NAND device 1753 -53 common/cmd_nand.c Bad usage of "nand" command 1754 53 common/cmd_nand.c correct usage of "nand" command 1755 -54 common/cmd_nand.c No boot device 1756 54 common/cmd_nand.c boot device found 1757 -55 common/cmd_nand.c Unknown Chip ID on boot device 1758 55 common/cmd_nand.c correct chip ID found, device available 1759 -56 common/cmd_nand.c Error reading Image Header on boot device 1760 56 common/cmd_nand.c reading Image Header from NAND device OK 1761 -57 common/cmd_nand.c Image header has bad magic number 1762 57 common/cmd_nand.c Image header has correct magic number 1763 -58 common/cmd_nand.c Error reading Image from NAND device 1764 58 common/cmd_nand.c reading Image from NAND device OK 1765 1766 -60 common/env_common.c Environment has a bad CRC, using default 1767 1768 64 net/eth.c starting with Ethernetconfiguration. 1769 -64 net/eth.c no Ethernet found. 1770 65 net/eth.c Ethernet found. 1771 1772 -80 common/cmd_net.c usage wrong 1773 80 common/cmd_net.c before calling NetLoop() 1774 -81 common/cmd_net.c some error in NetLoop() occured 1775 81 common/cmd_net.c NetLoop() back without error 1776 -82 common/cmd_net.c size == 0 (File with size 0 loaded) 1777 82 common/cmd_net.c trying automatic boot 1778 83 common/cmd_net.c running autoscript 1779 -83 common/cmd_net.c some error in automatic boot or autoscript 1780 84 common/cmd_net.c end without errors 1781 1782FIT uImage format: 1783 1784 Arg Where When 1785 100 common/cmd_bootm.c Kernel FIT Image has correct format 1786 -100 common/cmd_bootm.c Kernel FIT Image has incorrect format 1787 101 common/cmd_bootm.c No Kernel subimage unit name, using configuration 1788 -101 common/cmd_bootm.c Can't get configuration for kernel subimage 1789 102 common/cmd_bootm.c Kernel unit name specified 1790 -103 common/cmd_bootm.c Can't get kernel subimage node offset 1791 103 common/cmd_bootm.c Found configuration node 1792 104 common/cmd_bootm.c Got kernel subimage node offset 1793 -104 common/cmd_bootm.c Kernel subimage hash verification failed 1794 105 common/cmd_bootm.c Kernel subimage hash verification OK 1795 -105 common/cmd_bootm.c Kernel subimage is for unsupported architecture 1796 106 common/cmd_bootm.c Architecture check OK 1797 -106 common/cmd_bootm.c Kernel subimage has wrong typea 1798 107 common/cmd_bootm.c Kernel subimge type OK 1799 -107 common/cmd_bootm.c Can't get kernel subimage data/size 1800 108 common/cmd_bootm.c Got kernel subimage data/size 1801 -108 common/cmd_bootm.c Wrong image type (not legacy, FIT) 1802 -109 common/cmd_bootm.c Can't get kernel subimage type 1803 -110 common/cmd_bootm.c Can't get kernel subimage comp 1804 -111 common/cmd_bootm.c Can't get kernel subimage os 1805 -112 common/cmd_bootm.c Can't get kernel subimage load address 1806 -113 common/cmd_bootm.c Image uncompress/copy overwrite error 1807 1808 120 common/image.c Start initial ramdisk verification 1809 -120 common/image.c Ramdisk FIT image has incorrect format 1810 121 common/image.c Ramdisk FIT image has correct format 1811 122 common/image.c No Ramdisk subimage unit name, using configuration 1812 -122 common/image.c Can't get configuration for ramdisk subimage 1813 123 common/image.c Ramdisk unit name specified 1814 -124 common/image.c Can't get ramdisk subimage node offset 1815 125 common/image.c Got ramdisk subimage node offset 1816 -125 common/image.c Ramdisk subimage hash verification failed 1817 126 common/image.c Ramdisk subimage hash verification OK 1818 -126 common/image.c Ramdisk subimage for unsupported architecture 1819 127 common/image.c Architecture check OK 1820 -127 common/image.c Can't get ramdisk subimage data/size 1821 128 common/image.c Got ramdisk subimage data/size 1822 129 common/image.c Can't get ramdisk load address 1823 -129 common/image.c Got ramdisk load address 1824 1825 -130 common/cmd_doc.c Icorrect FIT image format 1826 131 common/cmd_doc.c FIT image format OK 1827 1828 -140 common/cmd_ide.c Icorrect FIT image format 1829 141 common/cmd_ide.c FIT image format OK 1830 1831 -150 common/cmd_nand.c Icorrect FIT image format 1832 151 common/cmd_nand.c FIT image format OK 1833 1834 1835Modem Support: 1836-------------- 1837 1838[so far only for SMDK2400 and TRAB boards] 1839 1840- Modem support endable: 1841 CONFIG_MODEM_SUPPORT 1842 1843- RTS/CTS Flow control enable: 1844 CONFIG_HWFLOW 1845 1846- Modem debug support: 1847 CONFIG_MODEM_SUPPORT_DEBUG 1848 1849 Enables debugging stuff (char screen[1024], dbg()) 1850 for modem support. Useful only with BDI2000. 1851 1852- Interrupt support (PPC): 1853 1854 There are common interrupt_init() and timer_interrupt() 1855 for all PPC archs. interrupt_init() calls interrupt_init_cpu() 1856 for cpu specific initialization. interrupt_init_cpu() 1857 should set decrementer_count to appropriate value. If 1858 cpu resets decrementer automatically after interrupt 1859 (ppc4xx) it should set decrementer_count to zero. 1860 timer_interrupt() calls timer_interrupt_cpu() for cpu 1861 specific handling. If board has watchdog / status_led 1862 / other_activity_monitor it works automatically from 1863 general timer_interrupt(). 1864 1865- General: 1866 1867 In the target system modem support is enabled when a 1868 specific key (key combination) is pressed during 1869 power-on. Otherwise U-Boot will boot normally 1870 (autoboot). The key_pressed() fuction is called from 1871 board_init(). Currently key_pressed() is a dummy 1872 function, returning 1 and thus enabling modem 1873 initialization. 1874 1875 If there are no modem init strings in the 1876 environment, U-Boot proceed to autoboot; the 1877 previous output (banner, info printfs) will be 1878 supressed, though. 1879 1880 See also: doc/README.Modem 1881 1882 1883Configuration Settings: 1884----------------------- 1885 1886- CFG_LONGHELP: Defined when you want long help messages included; 1887 undefine this when you're short of memory. 1888 1889- CFG_PROMPT: This is what U-Boot prints on the console to 1890 prompt for user input. 1891 1892- CFG_CBSIZE: Buffer size for input from the Console 1893 1894- CFG_PBSIZE: Buffer size for Console output 1895 1896- CFG_MAXARGS: max. Number of arguments accepted for monitor commands 1897 1898- CFG_BARGSIZE: Buffer size for Boot Arguments which are passed to 1899 the application (usually a Linux kernel) when it is 1900 booted 1901 1902- CFG_BAUDRATE_TABLE: 1903 List of legal baudrate settings for this board. 1904 1905- CFG_CONSOLE_INFO_QUIET 1906 Suppress display of console information at boot. 1907 1908- CFG_CONSOLE_IS_IN_ENV 1909 If the board specific function 1910 extern int overwrite_console (void); 1911 returns 1, the stdin, stderr and stdout are switched to the 1912 serial port, else the settings in the environment are used. 1913 1914- CFG_CONSOLE_OVERWRITE_ROUTINE 1915 Enable the call to overwrite_console(). 1916 1917- CFG_CONSOLE_ENV_OVERWRITE 1918 Enable overwrite of previous console environment settings. 1919 1920- CFG_MEMTEST_START, CFG_MEMTEST_END: 1921 Begin and End addresses of the area used by the 1922 simple memory test. 1923 1924- CFG_ALT_MEMTEST: 1925 Enable an alternate, more extensive memory test. 1926 1927- CFG_MEMTEST_SCRATCH: 1928 Scratch address used by the alternate memory test 1929 You only need to set this if address zero isn't writeable 1930 1931- CFG_TFTP_LOADADDR: 1932 Default load address for network file downloads 1933 1934- CFG_LOADS_BAUD_CHANGE: 1935 Enable temporary baudrate change while serial download 1936 1937- CFG_SDRAM_BASE: 1938 Physical start address of SDRAM. _Must_ be 0 here. 1939 1940- CFG_MBIO_BASE: 1941 Physical start address of Motherboard I/O (if using a 1942 Cogent motherboard) 1943 1944- CFG_FLASH_BASE: 1945 Physical start address of Flash memory. 1946 1947- CFG_MONITOR_BASE: 1948 Physical start address of boot monitor code (set by 1949 make config files to be same as the text base address 1950 (TEXT_BASE) used when linking) - same as 1951 CFG_FLASH_BASE when booting from flash. 1952 1953- CFG_MONITOR_LEN: 1954 Size of memory reserved for monitor code, used to 1955 determine _at_compile_time_ (!) if the environment is 1956 embedded within the U-Boot image, or in a separate 1957 flash sector. 1958 1959- CFG_MALLOC_LEN: 1960 Size of DRAM reserved for malloc() use. 1961 1962- CFG_BOOTM_LEN: 1963 Normally compressed uImages are limited to an 1964 uncompressed size of 8 MBytes. If this is not enough, 1965 you can define CFG_BOOTM_LEN in your board config file 1966 to adjust this setting to your needs. 1967 1968- CFG_BOOTMAPSZ: 1969 Maximum size of memory mapped by the startup code of 1970 the Linux kernel; all data that must be processed by 1971 the Linux kernel (bd_info, boot arguments, eventually 1972 initrd image) must be put below this limit. 1973 1974- CFG_MAX_FLASH_BANKS: 1975 Max number of Flash memory banks 1976 1977- CFG_MAX_FLASH_SECT: 1978 Max number of sectors on a Flash chip 1979 1980- CFG_FLASH_ERASE_TOUT: 1981 Timeout for Flash erase operations (in ms) 1982 1983- CFG_FLASH_WRITE_TOUT: 1984 Timeout for Flash write operations (in ms) 1985 1986- CFG_FLASH_LOCK_TOUT 1987 Timeout for Flash set sector lock bit operation (in ms) 1988 1989- CFG_FLASH_UNLOCK_TOUT 1990 Timeout for Flash clear lock bits operation (in ms) 1991 1992- CFG_FLASH_PROTECTION 1993 If defined, hardware flash sectors protection is used 1994 instead of U-Boot software protection. 1995 1996- CFG_DIRECT_FLASH_TFTP: 1997 1998 Enable TFTP transfers directly to flash memory; 1999 without this option such a download has to be 2000 performed in two steps: (1) download to RAM, and (2) 2001 copy from RAM to flash. 2002 2003 The two-step approach is usually more reliable, since 2004 you can check if the download worked before you erase 2005 the flash, but in some situations (when sytem RAM is 2006 too limited to allow for a tempory copy of the 2007 downloaded image) this option may be very useful. 2008 2009- CFG_FLASH_CFI: 2010 Define if the flash driver uses extra elements in the 2011 common flash structure for storing flash geometry. 2012 2013- CFG_FLASH_CFI_DRIVER 2014 This option also enables the building of the cfi_flash driver 2015 in the drivers directory 2016 2017- CFG_FLASH_QUIET_TEST 2018 If this option is defined, the common CFI flash doesn't 2019 print it's warning upon not recognized FLASH banks. This 2020 is useful, if some of the configured banks are only 2021 optionally available. 2022 2023- CONFIG_FLASH_SHOW_PROGRESS 2024 If defined (must be an integer), print out countdown 2025 digits and dots. Recommended value: 45 (9..1) for 80 2026 column displays, 15 (3..1) for 40 column displays. 2027 2028- CFG_RX_ETH_BUFFER: 2029 Defines the number of ethernet receive buffers. On some 2030 ethernet controllers it is recommended to set this value 2031 to 8 or even higher (EEPRO100 or 405 EMAC), since all 2032 buffers can be full shortly after enabling the interface 2033 on high ethernet traffic. 2034 Defaults to 4 if not defined. 2035 2036The following definitions that deal with the placement and management 2037of environment data (variable area); in general, we support the 2038following configurations: 2039 2040- CFG_ENV_IS_IN_FLASH: 2041 2042 Define this if the environment is in flash memory. 2043 2044 a) The environment occupies one whole flash sector, which is 2045 "embedded" in the text segment with the U-Boot code. This 2046 happens usually with "bottom boot sector" or "top boot 2047 sector" type flash chips, which have several smaller 2048 sectors at the start or the end. For instance, such a 2049 layout can have sector sizes of 8, 2x4, 16, Nx32 kB. In 2050 such a case you would place the environment in one of the 2051 4 kB sectors - with U-Boot code before and after it. With 2052 "top boot sector" type flash chips, you would put the 2053 environment in one of the last sectors, leaving a gap 2054 between U-Boot and the environment. 2055 2056 - CFG_ENV_OFFSET: 2057 2058 Offset of environment data (variable area) to the 2059 beginning of flash memory; for instance, with bottom boot 2060 type flash chips the second sector can be used: the offset 2061 for this sector is given here. 2062 2063 CFG_ENV_OFFSET is used relative to CFG_FLASH_BASE. 2064 2065 - CFG_ENV_ADDR: 2066 2067 This is just another way to specify the start address of 2068 the flash sector containing the environment (instead of 2069 CFG_ENV_OFFSET). 2070 2071 - CFG_ENV_SECT_SIZE: 2072 2073 Size of the sector containing the environment. 2074 2075 2076 b) Sometimes flash chips have few, equal sized, BIG sectors. 2077 In such a case you don't want to spend a whole sector for 2078 the environment. 2079 2080 - CFG_ENV_SIZE: 2081 2082 If you use this in combination with CFG_ENV_IS_IN_FLASH 2083 and CFG_ENV_SECT_SIZE, you can specify to use only a part 2084 of this flash sector for the environment. This saves 2085 memory for the RAM copy of the environment. 2086 2087 It may also save flash memory if you decide to use this 2088 when your environment is "embedded" within U-Boot code, 2089 since then the remainder of the flash sector could be used 2090 for U-Boot code. It should be pointed out that this is 2091 STRONGLY DISCOURAGED from a robustness point of view: 2092 updating the environment in flash makes it always 2093 necessary to erase the WHOLE sector. If something goes 2094 wrong before the contents has been restored from a copy in 2095 RAM, your target system will be dead. 2096 2097 - CFG_ENV_ADDR_REDUND 2098 CFG_ENV_SIZE_REDUND 2099 2100 These settings describe a second storage area used to hold 2101 a redundand copy of the environment data, so that there is 2102 a valid backup copy in case there is a power failure during 2103 a "saveenv" operation. 2104 2105BE CAREFUL! Any changes to the flash layout, and some changes to the 2106source code will make it necessary to adapt <board>/u-boot.lds* 2107accordingly! 2108 2109 2110- CFG_ENV_IS_IN_NVRAM: 2111 2112 Define this if you have some non-volatile memory device 2113 (NVRAM, battery buffered SRAM) which you want to use for the 2114 environment. 2115 2116 - CFG_ENV_ADDR: 2117 - CFG_ENV_SIZE: 2118 2119 These two #defines are used to determin the memory area you 2120 want to use for environment. It is assumed that this memory 2121 can just be read and written to, without any special 2122 provision. 2123 2124BE CAREFUL! The first access to the environment happens quite early 2125in U-Boot initalization (when we try to get the setting of for the 2126console baudrate). You *MUST* have mappend your NVRAM area then, or 2127U-Boot will hang. 2128 2129Please note that even with NVRAM we still use a copy of the 2130environment in RAM: we could work on NVRAM directly, but we want to 2131keep settings there always unmodified except somebody uses "saveenv" 2132to save the current settings. 2133 2134 2135- CFG_ENV_IS_IN_EEPROM: 2136 2137 Use this if you have an EEPROM or similar serial access 2138 device and a driver for it. 2139 2140 - CFG_ENV_OFFSET: 2141 - CFG_ENV_SIZE: 2142 2143 These two #defines specify the offset and size of the 2144 environment area within the total memory of your EEPROM. 2145 2146 - CFG_I2C_EEPROM_ADDR: 2147 If defined, specified the chip address of the EEPROM device. 2148 The default address is zero. 2149 2150 - CFG_EEPROM_PAGE_WRITE_BITS: 2151 If defined, the number of bits used to address bytes in a 2152 single page in the EEPROM device. A 64 byte page, for example 2153 would require six bits. 2154 2155 - CFG_EEPROM_PAGE_WRITE_DELAY_MS: 2156 If defined, the number of milliseconds to delay between 2157 page writes. The default is zero milliseconds. 2158 2159 - CFG_I2C_EEPROM_ADDR_LEN: 2160 The length in bytes of the EEPROM memory array address. Note 2161 that this is NOT the chip address length! 2162 2163 - CFG_I2C_EEPROM_ADDR_OVERFLOW: 2164 EEPROM chips that implement "address overflow" are ones 2165 like Catalyst 24WC04/08/16 which has 9/10/11 bits of 2166 address and the extra bits end up in the "chip address" bit 2167 slots. This makes a 24WC08 (1Kbyte) chip look like four 256 2168 byte chips. 2169 2170 Note that we consider the length of the address field to 2171 still be one byte because the extra address bits are hidden 2172 in the chip address. 2173 2174 - CFG_EEPROM_SIZE: 2175 The size in bytes of the EEPROM device. 2176 2177 2178- CFG_ENV_IS_IN_DATAFLASH: 2179 2180 Define this if you have a DataFlash memory device which you 2181 want to use for the environment. 2182 2183 - CFG_ENV_OFFSET: 2184 - CFG_ENV_ADDR: 2185 - CFG_ENV_SIZE: 2186 2187 These three #defines specify the offset and size of the 2188 environment area within the total memory of your DataFlash placed 2189 at the specified address. 2190 2191- CFG_ENV_IS_IN_NAND: 2192 2193 Define this if you have a NAND device which you want to use 2194 for the environment. 2195 2196 - CFG_ENV_OFFSET: 2197 - CFG_ENV_SIZE: 2198 2199 These two #defines specify the offset and size of the environment 2200 area within the first NAND device. 2201 2202 - CFG_ENV_OFFSET_REDUND 2203 2204 This setting describes a second storage area of CFG_ENV_SIZE 2205 size used to hold a redundant copy of the environment data, 2206 so that there is a valid backup copy in case there is a 2207 power failure during a "saveenv" operation. 2208 2209 Note: CFG_ENV_OFFSET and CFG_ENV_OFFSET_REDUND must be aligned 2210 to a block boundary, and CFG_ENV_SIZE must be a multiple of 2211 the NAND devices block size. 2212 2213- CFG_SPI_INIT_OFFSET 2214 2215 Defines offset to the initial SPI buffer area in DPRAM. The 2216 area is used at an early stage (ROM part) if the environment 2217 is configured to reside in the SPI EEPROM: We need a 520 byte 2218 scratch DPRAM area. It is used between the two initialization 2219 calls (spi_init_f() and spi_init_r()). A value of 0xB00 seems 2220 to be a good choice since it makes it far enough from the 2221 start of the data area as well as from the stack pointer. 2222 2223Please note that the environment is read-only until the monitor 2224has been relocated to RAM and a RAM copy of the environment has been 2225created; also, when using EEPROM you will have to use getenv_r() 2226until then to read environment variables. 2227 2228The environment is protected by a CRC32 checksum. Before the monitor 2229is relocated into RAM, as a result of a bad CRC you will be working 2230with the compiled-in default environment - *silently*!!! [This is 2231necessary, because the first environment variable we need is the 2232"baudrate" setting for the console - if we have a bad CRC, we don't 2233have any device yet where we could complain.] 2234 2235Note: once the monitor has been relocated, then it will complain if 2236the default environment is used; a new CRC is computed as soon as you 2237use the "saveenv" command to store a valid environment. 2238 2239- CFG_FAULT_ECHO_LINK_DOWN: 2240 Echo the inverted Ethernet link state to the fault LED. 2241 2242 Note: If this option is active, then CFG_FAULT_MII_ADDR 2243 also needs to be defined. 2244 2245- CFG_FAULT_MII_ADDR: 2246 MII address of the PHY to check for the Ethernet link state. 2247 2248- CFG_64BIT_VSPRINTF: 2249 Makes vsprintf (and all *printf functions) support printing 2250 of 64bit values by using the L quantifier 2251 2252- CFG_64BIT_STRTOUL: 2253 Adds simple_strtoull that returns a 64bit value 2254 2255Low Level (hardware related) configuration options: 2256--------------------------------------------------- 2257 2258- CFG_CACHELINE_SIZE: 2259 Cache Line Size of the CPU. 2260 2261- CFG_DEFAULT_IMMR: 2262 Default address of the IMMR after system reset. 2263 2264 Needed on some 8260 systems (MPC8260ADS, PQ2FADS-ZU, 2265 and RPXsuper) to be able to adjust the position of 2266 the IMMR register after a reset. 2267 2268- Floppy Disk Support: 2269 CFG_FDC_DRIVE_NUMBER 2270 2271 the default drive number (default value 0) 2272 2273 CFG_ISA_IO_STRIDE 2274 2275 defines the spacing between fdc chipset registers 2276 (default value 1) 2277 2278 CFG_ISA_IO_OFFSET 2279 2280 defines the offset of register from address. It 2281 depends on which part of the data bus is connected to 2282 the fdc chipset. (default value 0) 2283 2284 If CFG_ISA_IO_STRIDE CFG_ISA_IO_OFFSET and 2285 CFG_FDC_DRIVE_NUMBER are undefined, they take their 2286 default value. 2287 2288 if CFG_FDC_HW_INIT is defined, then the function 2289 fdc_hw_init() is called at the beginning of the FDC 2290 setup. fdc_hw_init() must be provided by the board 2291 source code. It is used to make hardware dependant 2292 initializations. 2293 2294- CFG_IMMR: Physical address of the Internal Memory. 2295 DO NOT CHANGE unless you know exactly what you're 2296 doing! (11-4) [MPC8xx/82xx systems only] 2297 2298- CFG_INIT_RAM_ADDR: 2299 2300 Start address of memory area that can be used for 2301 initial data and stack; please note that this must be 2302 writable memory that is working WITHOUT special 2303 initialization, i. e. you CANNOT use normal RAM which 2304 will become available only after programming the 2305 memory controller and running certain initialization 2306 sequences. 2307 2308 U-Boot uses the following memory types: 2309 - MPC8xx and MPC8260: IMMR (internal memory of the CPU) 2310 - MPC824X: data cache 2311 - PPC4xx: data cache 2312 2313- CFG_GBL_DATA_OFFSET: 2314 2315 Offset of the initial data structure in the memory 2316 area defined by CFG_INIT_RAM_ADDR. Usually 2317 CFG_GBL_DATA_OFFSET is chosen such that the initial 2318 data is located at the end of the available space 2319 (sometimes written as (CFG_INIT_RAM_END - 2320 CFG_INIT_DATA_SIZE), and the initial stack is just 2321 below that area (growing from (CFG_INIT_RAM_ADDR + 2322 CFG_GBL_DATA_OFFSET) downward. 2323 2324 Note: 2325 On the MPC824X (or other systems that use the data 2326 cache for initial memory) the address chosen for 2327 CFG_INIT_RAM_ADDR is basically arbitrary - it must 2328 point to an otherwise UNUSED address space between 2329 the top of RAM and the start of the PCI space. 2330 2331- CFG_SIUMCR: SIU Module Configuration (11-6) 2332 2333- CFG_SYPCR: System Protection Control (11-9) 2334 2335- CFG_TBSCR: Time Base Status and Control (11-26) 2336 2337- CFG_PISCR: Periodic Interrupt Status and Control (11-31) 2338 2339- CFG_PLPRCR: PLL, Low-Power, and Reset Control Register (15-30) 2340 2341- CFG_SCCR: System Clock and reset Control Register (15-27) 2342 2343- CFG_OR_TIMING_SDRAM: 2344 SDRAM timing 2345 2346- CFG_MAMR_PTA: 2347 periodic timer for refresh 2348 2349- CFG_DER: Debug Event Register (37-47) 2350 2351- FLASH_BASE0_PRELIM, FLASH_BASE1_PRELIM, CFG_REMAP_OR_AM, 2352 CFG_PRELIM_OR_AM, CFG_OR_TIMING_FLASH, CFG_OR0_REMAP, 2353 CFG_OR0_PRELIM, CFG_BR0_PRELIM, CFG_OR1_REMAP, CFG_OR1_PRELIM, 2354 CFG_BR1_PRELIM: 2355 Memory Controller Definitions: BR0/1 and OR0/1 (FLASH) 2356 2357- SDRAM_BASE2_PRELIM, SDRAM_BASE3_PRELIM, SDRAM_MAX_SIZE, 2358 CFG_OR_TIMING_SDRAM, CFG_OR2_PRELIM, CFG_BR2_PRELIM, 2359 CFG_OR3_PRELIM, CFG_BR3_PRELIM: 2360 Memory Controller Definitions: BR2/3 and OR2/3 (SDRAM) 2361 2362- CFG_MAMR_PTA, CFG_MPTPR_2BK_4K, CFG_MPTPR_1BK_4K, CFG_MPTPR_2BK_8K, 2363 CFG_MPTPR_1BK_8K, CFG_MAMR_8COL, CFG_MAMR_9COL: 2364 Machine Mode Register and Memory Periodic Timer 2365 Prescaler definitions (SDRAM timing) 2366 2367- CFG_I2C_UCODE_PATCH, CFG_I2C_DPMEM_OFFSET [0x1FC0]: 2368 enable I2C microcode relocation patch (MPC8xx); 2369 define relocation offset in DPRAM [DSP2] 2370 2371- CFG_SMC_UCODE_PATCH, CFG_SMC_DPMEM_OFFSET [0x1FC0]: 2372 enable SMC microcode relocation patch (MPC8xx); 2373 define relocation offset in DPRAM [SMC1] 2374 2375- CFG_SPI_UCODE_PATCH, CFG_SPI_DPMEM_OFFSET [0x1FC0]: 2376 enable SPI microcode relocation patch (MPC8xx); 2377 define relocation offset in DPRAM [SCC4] 2378 2379- CFG_USE_OSCCLK: 2380 Use OSCM clock mode on MBX8xx board. Be careful, 2381 wrong setting might damage your board. Read 2382 doc/README.MBX before setting this variable! 2383 2384- CFG_CPM_POST_WORD_ADDR: (MPC8xx, MPC8260 only) 2385 Offset of the bootmode word in DPRAM used by post 2386 (Power On Self Tests). This definition overrides 2387 #define'd default value in commproc.h resp. 2388 cpm_8260.h. 2389 2390- CFG_PCI_SLV_MEM_LOCAL, CFG_PCI_SLV_MEM_BUS, CFG_PICMR0_MASK_ATTRIB, 2391 CFG_PCI_MSTR0_LOCAL, CFG_PCIMSK0_MASK, CFG_PCI_MSTR1_LOCAL, 2392 CFG_PCIMSK1_MASK, CFG_PCI_MSTR_MEM_LOCAL, CFG_PCI_MSTR_MEM_BUS, 2393 CFG_CPU_PCI_MEM_START, CFG_PCI_MSTR_MEM_SIZE, CFG_POCMR0_MASK_ATTRIB, 2394 CFG_PCI_MSTR_MEMIO_LOCAL, CFG_PCI_MSTR_MEMIO_BUS, CPU_PCI_MEMIO_START, 2395 CFG_PCI_MSTR_MEMIO_SIZE, CFG_POCMR1_MASK_ATTRIB, CFG_PCI_MSTR_IO_LOCAL, 2396 CFG_PCI_MSTR_IO_BUS, CFG_CPU_PCI_IO_START, CFG_PCI_MSTR_IO_SIZE, 2397 CFG_POCMR2_MASK_ATTRIB: (MPC826x only) 2398 Overrides the default PCI memory map in cpu/mpc8260/pci.c if set. 2399 2400- CONFIG_SPD_EEPROM 2401 Get DDR timing information from an I2C EEPROM. Common 2402 with pluggable memory modules such as SODIMMs 2403 2404 SPD_EEPROM_ADDRESS 2405 I2C address of the SPD EEPROM 2406 2407- CFG_SPD_BUS_NUM 2408 If SPD EEPROM is on an I2C bus other than the first 2409 one, specify here. Note that the value must resolve 2410 to something your driver can deal with. 2411 2412- CFG_83XX_DDR_USES_CS0 2413 Only for 83xx systems. If specified, then DDR should 2414 be configured using CS0 and CS1 instead of CS2 and CS3. 2415 2416- CFG_83XX_DDR_USES_CS0 2417 Only for 83xx systems. If specified, then DDR should 2418 be configured using CS0 and CS1 instead of CS2 and CS3. 2419 2420- CONFIG_ETHER_ON_FEC[12] 2421 Define to enable FEC[12] on a 8xx series processor. 2422 2423- CONFIG_FEC[12]_PHY 2424 Define to the hardcoded PHY address which corresponds 2425 to the given FEC; i. e. 2426 #define CONFIG_FEC1_PHY 4 2427 means that the PHY with address 4 is connected to FEC1 2428 2429 When set to -1, means to probe for first available. 2430 2431- CONFIG_FEC[12]_PHY_NORXERR 2432 The PHY does not have a RXERR line (RMII only). 2433 (so program the FEC to ignore it). 2434 2435- CONFIG_RMII 2436 Enable RMII mode for all FECs. 2437 Note that this is a global option, we can't 2438 have one FEC in standard MII mode and another in RMII mode. 2439 2440- CONFIG_CRC32_VERIFY 2441 Add a verify option to the crc32 command. 2442 The syntax is: 2443 2444 => crc32 -v <address> <count> <crc32> 2445 2446 Where address/count indicate a memory area 2447 and crc32 is the correct crc32 which the 2448 area should have. 2449 2450- CONFIG_LOOPW 2451 Add the "loopw" memory command. This only takes effect if 2452 the memory commands are activated globally (CONFIG_CMD_MEM). 2453 2454- CONFIG_MX_CYCLIC 2455 Add the "mdc" and "mwc" memory commands. These are cyclic 2456 "md/mw" commands. 2457 Examples: 2458 2459 => mdc.b 10 4 500 2460 This command will print 4 bytes (10,11,12,13) each 500 ms. 2461 2462 => mwc.l 100 12345678 10 2463 This command will write 12345678 to address 100 all 10 ms. 2464 2465 This only takes effect if the memory commands are activated 2466 globally (CONFIG_CMD_MEM). 2467 2468- CONFIG_SKIP_LOWLEVEL_INIT 2469- CONFIG_SKIP_RELOCATE_UBOOT 2470 2471 [ARM only] If these variables are defined, then 2472 certain low level initializations (like setting up 2473 the memory controller) are omitted and/or U-Boot does 2474 not relocate itself into RAM. 2475 Normally these variables MUST NOT be defined. The 2476 only exception is when U-Boot is loaded (to RAM) by 2477 some other boot loader or by a debugger which 2478 performs these intializations itself. 2479 2480 2481Building the Software: 2482====================== 2483 2484Building U-Boot has been tested in several native build environments 2485and in many different cross environments. Of course we cannot support 2486all possibly existing versions of cross development tools in all 2487(potentially obsolete) versions. In case of tool chain problems we 2488recommend to use the ELDK (see http://www.denx.de/wiki/DULG/ELDK) 2489which is extensively used to build and test U-Boot. 2490 2491If you are not using a native environment, it is assumed that you 2492have GNU cross compiling tools available in your path. In this case, 2493you must set the environment variable CROSS_COMPILE in your shell. 2494Note that no changes to the Makefile or any other source files are 2495necessary. For example using the ELDK on a 4xx CPU, please enter: 2496 2497 $ CROSS_COMPILE=ppc_4xx- 2498 $ export CROSS_COMPILE 2499 2500U-Boot is intended to be simple to build. After installing the 2501sources you must configure U-Boot for one specific board type. This 2502is done by typing: 2503 2504 make NAME_config 2505 2506where "NAME_config" is the name of one of the existing configu- 2507rations; see the main Makefile for supported names. 2508 2509Note: for some board special configuration names may exist; check if 2510 additional information is available from the board vendor; for 2511 instance, the TQM823L systems are available without (standard) 2512 or with LCD support. You can select such additional "features" 2513 when chosing the configuration, i. e. 2514 2515 make TQM823L_config 2516 - will configure for a plain TQM823L, i. e. no LCD support 2517 2518 make TQM823L_LCD_config 2519 - will configure for a TQM823L with U-Boot console on LCD 2520 2521 etc. 2522 2523 2524Finally, type "make all", and you should get some working U-Boot 2525images ready for download to / installation on your system: 2526 2527- "u-boot.bin" is a raw binary image 2528- "u-boot" is an image in ELF binary format 2529- "u-boot.srec" is in Motorola S-Record format 2530 2531By default the build is performed locally and the objects are saved 2532in the source directory. One of the two methods can be used to change 2533this behavior and build U-Boot to some external directory: 2534 25351. Add O= to the make command line invocations: 2536 2537 make O=/tmp/build distclean 2538 make O=/tmp/build NAME_config 2539 make O=/tmp/build all 2540 25412. Set environment variable BUILD_DIR to point to the desired location: 2542 2543 export BUILD_DIR=/tmp/build 2544 make distclean 2545 make NAME_config 2546 make all 2547 2548Note that the command line "O=" setting overrides the BUILD_DIR environment 2549variable. 2550 2551 2552Please be aware that the Makefiles assume you are using GNU make, so 2553for instance on NetBSD you might need to use "gmake" instead of 2554native "make". 2555 2556 2557If the system board that you have is not listed, then you will need 2558to port U-Boot to your hardware platform. To do this, follow these 2559steps: 2560 25611. Add a new configuration option for your board to the toplevel 2562 "Makefile" and to the "MAKEALL" script, using the existing 2563 entries as examples. Note that here and at many other places 2564 boards and other names are listed in alphabetical sort order. Please 2565 keep this order. 25662. Create a new directory to hold your board specific code. Add any 2567 files you need. In your board directory, you will need at least 2568 the "Makefile", a "<board>.c", "flash.c" and "u-boot.lds". 25693. Create a new configuration file "include/configs/<board>.h" for 2570 your board 25713. If you're porting U-Boot to a new CPU, then also create a new 2572 directory to hold your CPU specific code. Add any files you need. 25734. Run "make <board>_config" with your new name. 25745. Type "make", and you should get a working "u-boot.srec" file 2575 to be installed on your target system. 25766. Debug and solve any problems that might arise. 2577 [Of course, this last step is much harder than it sounds.] 2578 2579 2580Testing of U-Boot Modifications, Ports to New Hardware, etc.: 2581============================================================== 2582 2583If you have modified U-Boot sources (for instance added a new board 2584or support for new devices, a new CPU, etc.) you are expected to 2585provide feedback to the other developers. The feedback normally takes 2586the form of a "patch", i. e. a context diff against a certain (latest 2587official or latest in the git repository) version of U-Boot sources. 2588 2589But before you submit such a patch, please verify that your modifi- 2590cation did not break existing code. At least make sure that *ALL* of 2591the supported boards compile WITHOUT ANY compiler warnings. To do so, 2592just run the "MAKEALL" script, which will configure and build U-Boot 2593for ALL supported system. Be warned, this will take a while. You can 2594select which (cross) compiler to use by passing a `CROSS_COMPILE' 2595environment variable to the script, i. e. to use the ELDK cross tools 2596you can type 2597 2598 CROSS_COMPILE=ppc_8xx- MAKEALL 2599 2600or to build on a native PowerPC system you can type 2601 2602 CROSS_COMPILE=' ' MAKEALL 2603 2604When using the MAKEALL script, the default behaviour is to build 2605U-Boot in the source directory. This location can be changed by 2606setting the BUILD_DIR environment variable. Also, for each target 2607built, the MAKEALL script saves two log files (<target>.ERR and 2608<target>.MAKEALL) in the <source dir>/LOG directory. This default 2609location can be changed by setting the MAKEALL_LOGDIR environment 2610variable. For example: 2611 2612 export BUILD_DIR=/tmp/build 2613 export MAKEALL_LOGDIR=/tmp/log 2614 CROSS_COMPILE=ppc_8xx- MAKEALL 2615 2616With the above settings build objects are saved in the /tmp/build, 2617log files are saved in the /tmp/log and the source tree remains clean 2618during the whole build process. 2619 2620 2621See also "U-Boot Porting Guide" below. 2622 2623 2624Monitor Commands - Overview: 2625============================ 2626 2627go - start application at address 'addr' 2628run - run commands in an environment variable 2629bootm - boot application image from memory 2630bootp - boot image via network using BootP/TFTP protocol 2631tftpboot- boot image via network using TFTP protocol 2632 and env variables "ipaddr" and "serverip" 2633 (and eventually "gatewayip") 2634rarpboot- boot image via network using RARP/TFTP protocol 2635diskboot- boot from IDE devicebootd - boot default, i.e., run 'bootcmd' 2636loads - load S-Record file over serial line 2637loadb - load binary file over serial line (kermit mode) 2638md - memory display 2639mm - memory modify (auto-incrementing) 2640nm - memory modify (constant address) 2641mw - memory write (fill) 2642cp - memory copy 2643cmp - memory compare 2644crc32 - checksum calculation 2645imd - i2c memory display 2646imm - i2c memory modify (auto-incrementing) 2647inm - i2c memory modify (constant address) 2648imw - i2c memory write (fill) 2649icrc32 - i2c checksum calculation 2650iprobe - probe to discover valid I2C chip addresses 2651iloop - infinite loop on address range 2652isdram - print SDRAM configuration information 2653sspi - SPI utility commands 2654base - print or set address offset 2655printenv- print environment variables 2656setenv - set environment variables 2657saveenv - save environment variables to persistent storage 2658protect - enable or disable FLASH write protection 2659erase - erase FLASH memory 2660flinfo - print FLASH memory information 2661bdinfo - print Board Info structure 2662iminfo - print header information for application image 2663coninfo - print console devices and informations 2664ide - IDE sub-system 2665loop - infinite loop on address range 2666loopw - infinite write loop on address range 2667mtest - simple RAM test 2668icache - enable or disable instruction cache 2669dcache - enable or disable data cache 2670reset - Perform RESET of the CPU 2671echo - echo args to console 2672version - print monitor version 2673help - print online help 2674? - alias for 'help' 2675 2676 2677Monitor Commands - Detailed Description: 2678======================================== 2679 2680TODO. 2681 2682For now: just type "help <command>". 2683 2684 2685Environment Variables: 2686====================== 2687 2688U-Boot supports user configuration using Environment Variables which 2689can be made persistent by saving to Flash memory. 2690 2691Environment Variables are set using "setenv", printed using 2692"printenv", and saved to Flash using "saveenv". Using "setenv" 2693without a value can be used to delete a variable from the 2694environment. As long as you don't save the environment you are 2695working with an in-memory copy. In case the Flash area containing the 2696environment is erased by accident, a default environment is provided. 2697 2698Some configuration options can be set using Environment Variables: 2699 2700 baudrate - see CONFIG_BAUDRATE 2701 2702 bootdelay - see CONFIG_BOOTDELAY 2703 2704 bootcmd - see CONFIG_BOOTCOMMAND 2705 2706 bootargs - Boot arguments when booting an RTOS image 2707 2708 bootfile - Name of the image to load with TFTP 2709 2710 autoload - if set to "no" (any string beginning with 'n'), 2711 "bootp" will just load perform a lookup of the 2712 configuration from the BOOTP server, but not try to 2713 load any image using TFTP 2714 2715 autoscript - if set to "yes" commands like "loadb", "loady", 2716 "bootp", "tftpb", "rarpboot" and "nfs" will attempt 2717 to automatically run script images (by internally 2718 calling "autoscript"). 2719 2720 autoscript_uname - if script image is in a format (FIT) this 2721 variable is used to get script subimage unit name. 2722 2723 autostart - if set to "yes", an image loaded using the "bootp", 2724 "rarpboot", "tftpboot" or "diskboot" commands will 2725 be automatically started (by internally calling 2726 "bootm") 2727 2728 If set to "no", a standalone image passed to the 2729 "bootm" command will be copied to the load address 2730 (and eventually uncompressed), but NOT be started. 2731 This can be used to load and uncompress arbitrary 2732 data. 2733 2734 i2cfast - (PPC405GP|PPC405EP only) 2735 if set to 'y' configures Linux I2C driver for fast 2736 mode (400kHZ). This environment variable is used in 2737 initialization code. So, for changes to be effective 2738 it must be saved and board must be reset. 2739 2740 initrd_high - restrict positioning of initrd images: 2741 If this variable is not set, initrd images will be 2742 copied to the highest possible address in RAM; this 2743 is usually what you want since it allows for 2744 maximum initrd size. If for some reason you want to 2745 make sure that the initrd image is loaded below the 2746 CFG_BOOTMAPSZ limit, you can set this environment 2747 variable to a value of "no" or "off" or "0". 2748 Alternatively, you can set it to a maximum upper 2749 address to use (U-Boot will still check that it 2750 does not overwrite the U-Boot stack and data). 2751 2752 For instance, when you have a system with 16 MB 2753 RAM, and want to reserve 4 MB from use by Linux, 2754 you can do this by adding "mem=12M" to the value of 2755 the "bootargs" variable. However, now you must make 2756 sure that the initrd image is placed in the first 2757 12 MB as well - this can be done with 2758 2759 setenv initrd_high 00c00000 2760 2761 If you set initrd_high to 0xFFFFFFFF, this is an 2762 indication to U-Boot that all addresses are legal 2763 for the Linux kernel, including addresses in flash 2764 memory. In this case U-Boot will NOT COPY the 2765 ramdisk at all. This may be useful to reduce the 2766 boot time on your system, but requires that this 2767 feature is supported by your Linux kernel. 2768 2769 ipaddr - IP address; needed for tftpboot command 2770 2771 loadaddr - Default load address for commands like "bootp", 2772 "rarpboot", "tftpboot", "loadb" or "diskboot" 2773 2774 loads_echo - see CONFIG_LOADS_ECHO 2775 2776 serverip - TFTP server IP address; needed for tftpboot command 2777 2778 bootretry - see CONFIG_BOOT_RETRY_TIME 2779 2780 bootdelaykey - see CONFIG_AUTOBOOT_DELAY_STR 2781 2782 bootstopkey - see CONFIG_AUTOBOOT_STOP_STR 2783 2784 ethprime - When CONFIG_NET_MULTI is enabled controls which 2785 interface is used first. 2786 2787 ethact - When CONFIG_NET_MULTI is enabled controls which 2788 interface is currently active. For example you 2789 can do the following 2790 2791 => setenv ethact FEC ETHERNET 2792 => ping 192.168.0.1 # traffic sent on FEC ETHERNET 2793 => setenv ethact SCC ETHERNET 2794 => ping 10.0.0.1 # traffic sent on SCC ETHERNET 2795 2796 ethrotate - When set to "no" U-Boot does not go through all 2797 available network interfaces. 2798 It just stays at the currently selected interface. 2799 2800 netretry - When set to "no" each network operation will 2801 either succeed or fail without retrying. 2802 When set to "once" the network operation will 2803 fail when all the available network interfaces 2804 are tried once without success. 2805 Useful on scripts which control the retry operation 2806 themselves. 2807 2808 npe_ucode - see CONFIG_IXP4XX_NPE_EXT_UCOD 2809 if set load address for the npe microcode 2810 2811 tftpsrcport - If this is set, the value is used for TFTP's 2812 UDP source port. 2813 2814 tftpdstport - If this is set, the value is used for TFTP's UDP 2815 destination port instead of the Well Know Port 69. 2816 2817 vlan - When set to a value < 4095 the traffic over 2818 ethernet is encapsulated/received over 802.1q 2819 VLAN tagged frames. 2820 2821The following environment variables may be used and automatically 2822updated by the network boot commands ("bootp" and "rarpboot"), 2823depending the information provided by your boot server: 2824 2825 bootfile - see above 2826 dnsip - IP address of your Domain Name Server 2827 dnsip2 - IP address of your secondary Domain Name Server 2828 gatewayip - IP address of the Gateway (Router) to use 2829 hostname - Target hostname 2830 ipaddr - see above 2831 netmask - Subnet Mask 2832 rootpath - Pathname of the root filesystem on the NFS server 2833 serverip - see above 2834 2835 2836There are two special Environment Variables: 2837 2838 serial# - contains hardware identification information such 2839 as type string and/or serial number 2840 ethaddr - Ethernet address 2841 2842These variables can be set only once (usually during manufacturing of 2843the board). U-Boot refuses to delete or overwrite these variables 2844once they have been set once. 2845 2846 2847Further special Environment Variables: 2848 2849 ver - Contains the U-Boot version string as printed 2850 with the "version" command. This variable is 2851 readonly (see CONFIG_VERSION_VARIABLE). 2852 2853 2854Please note that changes to some configuration parameters may take 2855only effect after the next boot (yes, that's just like Windoze :-). 2856 2857 2858Command Line Parsing: 2859===================== 2860 2861There are two different command line parsers available with U-Boot: 2862the old "simple" one, and the much more powerful "hush" shell: 2863 2864Old, simple command line parser: 2865-------------------------------- 2866 2867- supports environment variables (through setenv / saveenv commands) 2868- several commands on one line, separated by ';' 2869- variable substitution using "... ${name} ..." syntax 2870- special characters ('$', ';') can be escaped by prefixing with '\', 2871 for example: 2872 setenv bootcmd bootm \${address} 2873- You can also escape text by enclosing in single apostrophes, for example: 2874 setenv addip 'setenv bootargs $bootargs ip=$ipaddr:$serverip:$gatewayip:$netmask:$hostname::off' 2875 2876Hush shell: 2877----------- 2878 2879- similar to Bourne shell, with control structures like 2880 if...then...else...fi, for...do...done; while...do...done, 2881 until...do...done, ... 2882- supports environment ("global") variables (through setenv / saveenv 2883 commands) and local shell variables (through standard shell syntax 2884 "name=value"); only environment variables can be used with "run" 2885 command 2886 2887General rules: 2888-------------- 2889 2890(1) If a command line (or an environment variable executed by a "run" 2891 command) contains several commands separated by semicolon, and 2892 one of these commands fails, then the remaining commands will be 2893 executed anyway. 2894 2895(2) If you execute several variables with one call to run (i. e. 2896 calling run with a list af variables as arguments), any failing 2897 command will cause "run" to terminate, i. e. the remaining 2898 variables are not executed. 2899 2900Note for Redundant Ethernet Interfaces: 2901======================================= 2902 2903Some boards come with redundant ethernet interfaces; U-Boot supports 2904such configurations and is capable of automatic selection of a 2905"working" interface when needed. MAC assignment works as follows: 2906 2907Network interfaces are numbered eth0, eth1, eth2, ... Corresponding 2908MAC addresses can be stored in the environment as "ethaddr" (=>eth0), 2909"eth1addr" (=>eth1), "eth2addr", ... 2910 2911If the network interface stores some valid MAC address (for instance 2912in SROM), this is used as default address if there is NO correspon- 2913ding setting in the environment; if the corresponding environment 2914variable is set, this overrides the settings in the card; that means: 2915 2916o If the SROM has a valid MAC address, and there is no address in the 2917 environment, the SROM's address is used. 2918 2919o If there is no valid address in the SROM, and a definition in the 2920 environment exists, then the value from the environment variable is 2921 used. 2922 2923o If both the SROM and the environment contain a MAC address, and 2924 both addresses are the same, this MAC address is used. 2925 2926o If both the SROM and the environment contain a MAC address, and the 2927 addresses differ, the value from the environment is used and a 2928 warning is printed. 2929 2930o If neither SROM nor the environment contain a MAC address, an error 2931 is raised. 2932 2933 2934Image Formats: 2935============== 2936 2937U-Boot is capable of booting (and performing other auxiliary operations on) 2938images in two formats: 2939 2940New uImage format (FIT) 2941----------------------- 2942 2943Flexible and powerful format based on Flattened Image Tree -- FIT (similar 2944to Flattened Device Tree). It allows the use of images with multiple 2945components (several kernels, ramdisks, etc.), with contents protected by 2946SHA1, MD5 or CRC32. More details are found in the doc/uImage.FIT directory. 2947 2948 2949Old uImage format 2950----------------- 2951 2952Old image format is based on binary files which can be basically anything, 2953preceded by a special header; see the definitions in include/image.h for 2954details; basically, the header defines the following image properties: 2955 2956* Target Operating System (Provisions for OpenBSD, NetBSD, FreeBSD, 2957 4.4BSD, Linux, SVR4, Esix, Solaris, Irix, SCO, Dell, NCR, VxWorks, 2958 LynxOS, pSOS, QNX, RTEMS, ARTOS; 2959 Currently supported: Linux, NetBSD, VxWorks, QNX, RTEMS, ARTOS, LynxOS). 2960* Target CPU Architecture (Provisions for Alpha, ARM, AVR32, Intel x86, 2961 IA64, MIPS, NIOS, PowerPC, IBM S390, SuperH, Sparc, Sparc 64 Bit; 2962 Currently supported: ARM, AVR32, Intel x86, MIPS, NIOS, PowerPC). 2963* Compression Type (uncompressed, gzip, bzip2) 2964* Load Address 2965* Entry Point 2966* Image Name 2967* Image Timestamp 2968 2969The header is marked by a special Magic Number, and both the header 2970and the data portions of the image are secured against corruption by 2971CRC32 checksums. 2972 2973 2974Linux Support: 2975============== 2976 2977Although U-Boot should support any OS or standalone application 2978easily, the main focus has always been on Linux during the design of 2979U-Boot. 2980 2981U-Boot includes many features that so far have been part of some 2982special "boot loader" code within the Linux kernel. Also, any 2983"initrd" images to be used are no longer part of one big Linux image; 2984instead, kernel and "initrd" are separate images. This implementation 2985serves several purposes: 2986 2987- the same features can be used for other OS or standalone 2988 applications (for instance: using compressed images to reduce the 2989 Flash memory footprint) 2990 2991- it becomes much easier to port new Linux kernel versions because 2992 lots of low-level, hardware dependent stuff are done by U-Boot 2993 2994- the same Linux kernel image can now be used with different "initrd" 2995 images; of course this also means that different kernel images can 2996 be run with the same "initrd". This makes testing easier (you don't 2997 have to build a new "zImage.initrd" Linux image when you just 2998 change a file in your "initrd"). Also, a field-upgrade of the 2999 software is easier now. 3000 3001 3002Linux HOWTO: 3003============ 3004 3005Porting Linux to U-Boot based systems: 3006--------------------------------------- 3007 3008U-Boot cannot save you from doing all the necessary modifications to 3009configure the Linux device drivers for use with your target hardware 3010(no, we don't intend to provide a full virtual machine interface to 3011Linux :-). 3012 3013But now you can ignore ALL boot loader code (in arch/ppc/mbxboot). 3014 3015Just make sure your machine specific header file (for instance 3016include/asm-ppc/tqm8xx.h) includes the same definition of the Board 3017Information structure as we define in include/u-boot.h, and make 3018sure that your definition of IMAP_ADDR uses the same value as your 3019U-Boot configuration in CFG_IMMR. 3020 3021 3022Configuring the Linux kernel: 3023----------------------------- 3024 3025No specific requirements for U-Boot. Make sure you have some root 3026device (initial ramdisk, NFS) for your target system. 3027 3028 3029Building a Linux Image: 3030----------------------- 3031 3032With U-Boot, "normal" build targets like "zImage" or "bzImage" are 3033not used. If you use recent kernel source, a new build target 3034"uImage" will exist which automatically builds an image usable by 3035U-Boot. Most older kernels also have support for a "pImage" target, 3036which was introduced for our predecessor project PPCBoot and uses a 3037100% compatible format. 3038 3039Example: 3040 3041 make TQM850L_config 3042 make oldconfig 3043 make dep 3044 make uImage 3045 3046The "uImage" build target uses a special tool (in 'tools/mkimage') to 3047encapsulate a compressed Linux kernel image with header information, 3048CRC32 checksum etc. for use with U-Boot. This is what we are doing: 3049 3050* build a standard "vmlinux" kernel image (in ELF binary format): 3051 3052* convert the kernel into a raw binary image: 3053 3054 ${CROSS_COMPILE}-objcopy -O binary \ 3055 -R .note -R .comment \ 3056 -S vmlinux linux.bin 3057 3058* compress the binary image: 3059 3060 gzip -9 linux.bin 3061 3062* package compressed binary image for U-Boot: 3063 3064 mkimage -A ppc -O linux -T kernel -C gzip \ 3065 -a 0 -e 0 -n "Linux Kernel Image" \ 3066 -d linux.bin.gz uImage 3067 3068 3069The "mkimage" tool can also be used to create ramdisk images for use 3070with U-Boot, either separated from the Linux kernel image, or 3071combined into one file. "mkimage" encapsulates the images with a 64 3072byte header containing information about target architecture, 3073operating system, image type, compression method, entry points, time 3074stamp, CRC32 checksums, etc. 3075 3076"mkimage" can be called in two ways: to verify existing images and 3077print the header information, or to build new images. 3078 3079In the first form (with "-l" option) mkimage lists the information 3080contained in the header of an existing U-Boot image; this includes 3081checksum verification: 3082 3083 tools/mkimage -l image 3084 -l ==> list image header information 3085 3086The second form (with "-d" option) is used to build a U-Boot image 3087from a "data file" which is used as image payload: 3088 3089 tools/mkimage -A arch -O os -T type -C comp -a addr -e ep \ 3090 -n name -d data_file image 3091 -A ==> set architecture to 'arch' 3092 -O ==> set operating system to 'os' 3093 -T ==> set image type to 'type' 3094 -C ==> set compression type 'comp' 3095 -a ==> set load address to 'addr' (hex) 3096 -e ==> set entry point to 'ep' (hex) 3097 -n ==> set image name to 'name' 3098 -d ==> use image data from 'datafile' 3099 3100Right now, all Linux kernels for PowerPC systems use the same load 3101address (0x00000000), but the entry point address depends on the 3102kernel version: 3103 3104- 2.2.x kernels have the entry point at 0x0000000C, 3105- 2.3.x and later kernels have the entry point at 0x00000000. 3106 3107So a typical call to build a U-Boot image would read: 3108 3109 -> tools/mkimage -n '2.4.4 kernel for TQM850L' \ 3110 > -A ppc -O linux -T kernel -C gzip -a 0 -e 0 \ 3111 > -d /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/ppc/coffboot/vmlinux.gz \ 3112 > examples/uImage.TQM850L 3113 Image Name: 2.4.4 kernel for TQM850L 3114 Created: Wed Jul 19 02:34:59 2000 3115 Image Type: PowerPC Linux Kernel Image (gzip compressed) 3116 Data Size: 335725 Bytes = 327.86 kB = 0.32 MB 3117 Load Address: 0x00000000 3118 Entry Point: 0x00000000 3119 3120To verify the contents of the image (or check for corruption): 3121 3122 -> tools/mkimage -l examples/uImage.TQM850L 3123 Image Name: 2.4.4 kernel for TQM850L 3124 Created: Wed Jul 19 02:34:59 2000 3125 Image Type: PowerPC Linux Kernel Image (gzip compressed) 3126 Data Size: 335725 Bytes = 327.86 kB = 0.32 MB 3127 Load Address: 0x00000000 3128 Entry Point: 0x00000000 3129 3130NOTE: for embedded systems where boot time is critical you can trade 3131speed for memory and install an UNCOMPRESSED image instead: this 3132needs more space in Flash, but boots much faster since it does not 3133need to be uncompressed: 3134 3135 -> gunzip /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/ppc/coffboot/vmlinux.gz 3136 -> tools/mkimage -n '2.4.4 kernel for TQM850L' \ 3137 > -A ppc -O linux -T kernel -C none -a 0 -e 0 \ 3138 > -d /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/ppc/coffboot/vmlinux \ 3139 > examples/uImage.TQM850L-uncompressed 3140 Image Name: 2.4.4 kernel for TQM850L 3141 Created: Wed Jul 19 02:34:59 2000 3142 Image Type: PowerPC Linux Kernel Image (uncompressed) 3143 Data Size: 792160 Bytes = 773.59 kB = 0.76 MB 3144 Load Address: 0x00000000 3145 Entry Point: 0x00000000 3146 3147 3148Similar you can build U-Boot images from a 'ramdisk.image.gz' file 3149when your kernel is intended to use an initial ramdisk: 3150 3151 -> tools/mkimage -n 'Simple Ramdisk Image' \ 3152 > -A ppc -O linux -T ramdisk -C gzip \ 3153 > -d /LinuxPPC/images/SIMPLE-ramdisk.image.gz examples/simple-initrd 3154 Image Name: Simple Ramdisk Image 3155 Created: Wed Jan 12 14:01:50 2000 3156 Image Type: PowerPC Linux RAMDisk Image (gzip compressed) 3157 Data Size: 566530 Bytes = 553.25 kB = 0.54 MB 3158 Load Address: 0x00000000 3159 Entry Point: 0x00000000 3160 3161 3162Installing a Linux Image: 3163------------------------- 3164 3165To downloading a U-Boot image over the serial (console) interface, 3166you must convert the image to S-Record format: 3167 3168 objcopy -I binary -O srec examples/image examples/image.srec 3169 3170The 'objcopy' does not understand the information in the U-Boot 3171image header, so the resulting S-Record file will be relative to 3172address 0x00000000. To load it to a given address, you need to 3173specify the target address as 'offset' parameter with the 'loads' 3174command. 3175 3176Example: install the image to address 0x40100000 (which on the 3177TQM8xxL is in the first Flash bank): 3178 3179 => erase 40100000 401FFFFF 3180 3181 .......... done 3182 Erased 8 sectors 3183 3184 => loads 40100000 3185 ## Ready for S-Record download ... 3186 ~>examples/image.srec 3187 1 2 3 4 5 6 7 8 9 10 11 12 13 ... 3188 ... 3189 15989 15990 15991 15992 3190 [file transfer complete] 3191 [connected] 3192 ## Start Addr = 0x00000000 3193 3194 3195You can check the success of the download using the 'iminfo' command; 3196this includes a checksum verification so you can be sure no data 3197corruption happened: 3198 3199 => imi 40100000 3200 3201 ## Checking Image at 40100000 ... 3202 Image Name: 2.2.13 for initrd on TQM850L 3203 Image Type: PowerPC Linux Kernel Image (gzip compressed) 3204 Data Size: 335725 Bytes = 327 kB = 0 MB 3205 Load Address: 00000000 3206 Entry Point: 0000000c 3207 Verifying Checksum ... OK 3208 3209 3210Boot Linux: 3211----------- 3212 3213The "bootm" command is used to boot an application that is stored in 3214memory (RAM or Flash). In case of a Linux kernel image, the contents 3215of the "bootargs" environment variable is passed to the kernel as 3216parameters. You can check and modify this variable using the 3217"printenv" and "setenv" commands: 3218 3219 3220 => printenv bootargs 3221 bootargs=root=/dev/ram 3222 3223 => setenv bootargs root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2 3224 3225 => printenv bootargs 3226 bootargs=root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2 3227 3228 => bootm 40020000 3229 ## Booting Linux kernel at 40020000 ... 3230 Image Name: 2.2.13 for NFS on TQM850L 3231 Image Type: PowerPC Linux Kernel Image (gzip compressed) 3232 Data Size: 381681 Bytes = 372 kB = 0 MB 3233 Load Address: 00000000 3234 Entry Point: 0000000c 3235 Verifying Checksum ... OK 3236 Uncompressing Kernel Image ... OK 3237 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 3238 Boot arguments: root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2 3239 time_init: decrementer frequency = 187500000/60 3240 Calibrating delay loop... 49.77 BogoMIPS 3241 Memory: 15208k available (700k kernel code, 444k data, 32k init) [c0000000,c1000000] 3242 ... 3243 3244If you want to boot a Linux kernel with initial ram disk, you pass 3245the memory addresses of both the kernel and the initrd image (PPBCOOT 3246format!) to the "bootm" command: 3247 3248 => imi 40100000 40200000 3249 3250 ## Checking Image at 40100000 ... 3251 Image Name: 2.2.13 for initrd on TQM850L 3252 Image Type: PowerPC Linux Kernel Image (gzip compressed) 3253 Data Size: 335725 Bytes = 327 kB = 0 MB 3254 Load Address: 00000000 3255 Entry Point: 0000000c 3256 Verifying Checksum ... OK 3257 3258 ## Checking Image at 40200000 ... 3259 Image Name: Simple Ramdisk Image 3260 Image Type: PowerPC Linux RAMDisk Image (gzip compressed) 3261 Data Size: 566530 Bytes = 553 kB = 0 MB 3262 Load Address: 00000000 3263 Entry Point: 00000000 3264 Verifying Checksum ... OK 3265 3266 => bootm 40100000 40200000 3267 ## Booting Linux kernel at 40100000 ... 3268 Image Name: 2.2.13 for initrd on TQM850L 3269 Image Type: PowerPC Linux Kernel Image (gzip compressed) 3270 Data Size: 335725 Bytes = 327 kB = 0 MB 3271 Load Address: 00000000 3272 Entry Point: 0000000c 3273 Verifying Checksum ... OK 3274 Uncompressing Kernel Image ... OK 3275 ## Loading RAMDisk Image at 40200000 ... 3276 Image Name: Simple Ramdisk Image 3277 Image Type: PowerPC Linux RAMDisk Image (gzip compressed) 3278 Data Size: 566530 Bytes = 553 kB = 0 MB 3279 Load Address: 00000000 3280 Entry Point: 00000000 3281 Verifying Checksum ... OK 3282 Loading Ramdisk ... OK 3283 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 3284 Boot arguments: root=/dev/ram 3285 time_init: decrementer frequency = 187500000/60 3286 Calibrating delay loop... 49.77 BogoMIPS 3287 ... 3288 RAMDISK: Compressed image found at block 0 3289 VFS: Mounted root (ext2 filesystem). 3290 3291 bash# 3292 3293Boot Linux and pass a flat device tree: 3294----------- 3295 3296First, U-Boot must be compiled with the appropriate defines. See the section 3297titled "Linux Kernel Interface" above for a more in depth explanation. The 3298following is an example of how to start a kernel and pass an updated 3299flat device tree: 3300 3301=> print oftaddr 3302oftaddr=0x300000 3303=> print oft 3304oft=oftrees/mpc8540ads.dtb 3305=> tftp $oftaddr $oft 3306Speed: 1000, full duplex 3307Using TSEC0 device 3308TFTP from server 192.168.1.1; our IP address is 192.168.1.101 3309Filename 'oftrees/mpc8540ads.dtb'. 3310Load address: 0x300000 3311Loading: # 3312done 3313Bytes transferred = 4106 (100a hex) 3314=> tftp $loadaddr $bootfile 3315Speed: 1000, full duplex 3316Using TSEC0 device 3317TFTP from server 192.168.1.1; our IP address is 192.168.1.2 3318Filename 'uImage'. 3319Load address: 0x200000 3320Loading:############ 3321done 3322Bytes transferred = 1029407 (fb51f hex) 3323=> print loadaddr 3324loadaddr=200000 3325=> print oftaddr 3326oftaddr=0x300000 3327=> bootm $loadaddr - $oftaddr 3328## Booting image at 00200000 ... 3329 Image Name: Linux-2.6.17-dirty 3330 Image Type: PowerPC Linux Kernel Image (gzip compressed) 3331 Data Size: 1029343 Bytes = 1005.2 kB 3332 Load Address: 00000000 3333 Entry Point: 00000000 3334 Verifying Checksum ... OK 3335 Uncompressing Kernel Image ... OK 3336Booting using flat device tree at 0x300000 3337Using MPC85xx ADS machine description 3338Memory CAM mapping: CAM0=256Mb, CAM1=256Mb, CAM2=0Mb residual: 0Mb 3339[snip] 3340 3341 3342More About U-Boot Image Types: 3343------------------------------ 3344 3345U-Boot supports the following image types: 3346 3347 "Standalone Programs" are directly runnable in the environment 3348 provided by U-Boot; it is expected that (if they behave 3349 well) you can continue to work in U-Boot after return from 3350 the Standalone Program. 3351 "OS Kernel Images" are usually images of some Embedded OS which 3352 will take over control completely. Usually these programs 3353 will install their own set of exception handlers, device 3354 drivers, set up the MMU, etc. - this means, that you cannot 3355 expect to re-enter U-Boot except by resetting the CPU. 3356 "RAMDisk Images" are more or less just data blocks, and their 3357 parameters (address, size) are passed to an OS kernel that is 3358 being started. 3359 "Multi-File Images" contain several images, typically an OS 3360 (Linux) kernel image and one or more data images like 3361 RAMDisks. This construct is useful for instance when you want 3362 to boot over the network using BOOTP etc., where the boot 3363 server provides just a single image file, but you want to get 3364 for instance an OS kernel and a RAMDisk image. 3365 3366 "Multi-File Images" start with a list of image sizes, each 3367 image size (in bytes) specified by an "uint32_t" in network 3368 byte order. This list is terminated by an "(uint32_t)0". 3369 Immediately after the terminating 0 follow the images, one by 3370 one, all aligned on "uint32_t" boundaries (size rounded up to 3371 a multiple of 4 bytes). 3372 3373 "Firmware Images" are binary images containing firmware (like 3374 U-Boot or FPGA images) which usually will be programmed to 3375 flash memory. 3376 3377 "Script files" are command sequences that will be executed by 3378 U-Boot's command interpreter; this feature is especially 3379 useful when you configure U-Boot to use a real shell (hush) 3380 as command interpreter. 3381 3382 3383Standalone HOWTO: 3384================= 3385 3386One of the features of U-Boot is that you can dynamically load and 3387run "standalone" applications, which can use some resources of 3388U-Boot like console I/O functions or interrupt services. 3389 3390Two simple examples are included with the sources: 3391 3392"Hello World" Demo: 3393------------------- 3394 3395'examples/hello_world.c' contains a small "Hello World" Demo 3396application; it is automatically compiled when you build U-Boot. 3397It's configured to run at address 0x00040004, so you can play with it 3398like that: 3399 3400 => loads 3401 ## Ready for S-Record download ... 3402 ~>examples/hello_world.srec 3403 1 2 3 4 5 6 7 8 9 10 11 ... 3404 [file transfer complete] 3405 [connected] 3406 ## Start Addr = 0x00040004 3407 3408 => go 40004 Hello World! This is a test. 3409 ## Starting application at 0x00040004 ... 3410 Hello World 3411 argc = 7 3412 argv[0] = "40004" 3413 argv[1] = "Hello" 3414 argv[2] = "World!" 3415 argv[3] = "This" 3416 argv[4] = "is" 3417 argv[5] = "a" 3418 argv[6] = "test." 3419 argv[7] = "<NULL>" 3420 Hit any key to exit ... 3421 3422 ## Application terminated, rc = 0x0 3423 3424Another example, which demonstrates how to register a CPM interrupt 3425handler with the U-Boot code, can be found in 'examples/timer.c'. 3426Here, a CPM timer is set up to generate an interrupt every second. 3427The interrupt service routine is trivial, just printing a '.' 3428character, but this is just a demo program. The application can be 3429controlled by the following keys: 3430 3431 ? - print current values og the CPM Timer registers 3432 b - enable interrupts and start timer 3433 e - stop timer and disable interrupts 3434 q - quit application 3435 3436 => loads 3437 ## Ready for S-Record download ... 3438 ~>examples/timer.srec 3439 1 2 3 4 5 6 7 8 9 10 11 ... 3440 [file transfer complete] 3441 [connected] 3442 ## Start Addr = 0x00040004 3443 3444 => go 40004 3445 ## Starting application at 0x00040004 ... 3446 TIMERS=0xfff00980 3447 Using timer 1 3448 tgcr @ 0xfff00980, tmr @ 0xfff00990, trr @ 0xfff00994, tcr @ 0xfff00998, tcn @ 0xfff0099c, ter @ 0xfff009b0 3449 3450Hit 'b': 3451 [q, b, e, ?] Set interval 1000000 us 3452 Enabling timer 3453Hit '?': 3454 [q, b, e, ?] ........ 3455 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0xef6, ter=0x0 3456Hit '?': 3457 [q, b, e, ?] . 3458 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x2ad4, ter=0x0 3459Hit '?': 3460 [q, b, e, ?] . 3461 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x1efc, ter=0x0 3462Hit '?': 3463 [q, b, e, ?] . 3464 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x169d, ter=0x0 3465Hit 'e': 3466 [q, b, e, ?] ...Stopping timer 3467Hit 'q': 3468 [q, b, e, ?] ## Application terminated, rc = 0x0 3469 3470 3471Minicom warning: 3472================ 3473 3474Over time, many people have reported problems when trying to use the 3475"minicom" terminal emulation program for serial download. I (wd) 3476consider minicom to be broken, and recommend not to use it. Under 3477Unix, I recommend to use C-Kermit for general purpose use (and 3478especially for kermit binary protocol download ("loadb" command), and 3479use "cu" for S-Record download ("loads" command). 3480 3481Nevertheless, if you absolutely want to use it try adding this 3482configuration to your "File transfer protocols" section: 3483 3484 Name Program Name U/D FullScr IO-Red. Multi 3485 X kermit /usr/bin/kermit -i -l %l -s Y U Y N N 3486 Y kermit /usr/bin/kermit -i -l %l -r N D Y N N 3487 3488 3489NetBSD Notes: 3490============= 3491 3492Starting at version 0.9.2, U-Boot supports NetBSD both as host 3493(build U-Boot) and target system (boots NetBSD/mpc8xx). 3494 3495Building requires a cross environment; it is known to work on 3496NetBSD/i386 with the cross-powerpc-netbsd-1.3 package (you will also 3497need gmake since the Makefiles are not compatible with BSD make). 3498Note that the cross-powerpc package does not install include files; 3499attempting to build U-Boot will fail because <machine/ansi.h> is 3500missing. This file has to be installed and patched manually: 3501 3502 # cd /usr/pkg/cross/powerpc-netbsd/include 3503 # mkdir powerpc 3504 # ln -s powerpc machine 3505 # cp /usr/src/sys/arch/powerpc/include/ansi.h powerpc/ansi.h 3506 # ${EDIT} powerpc/ansi.h ## must remove __va_list, _BSD_VA_LIST 3507 3508Native builds *don't* work due to incompatibilities between native 3509and U-Boot include files. 3510 3511Booting assumes that (the first part of) the image booted is a 3512stage-2 loader which in turn loads and then invokes the kernel 3513proper. Loader sources will eventually appear in the NetBSD source 3514tree (probably in sys/arc/mpc8xx/stand/u-boot_stage2/); in the 3515meantime, see ftp://ftp.denx.de/pub/u-boot/ppcboot_stage2.tar.gz 3516 3517 3518Implementation Internals: 3519========================= 3520 3521The following is not intended to be a complete description of every 3522implementation detail. However, it should help to understand the 3523inner workings of U-Boot and make it easier to port it to custom 3524hardware. 3525 3526 3527Initial Stack, Global Data: 3528--------------------------- 3529 3530The implementation of U-Boot is complicated by the fact that U-Boot 3531starts running out of ROM (flash memory), usually without access to 3532system RAM (because the memory controller is not initialized yet). 3533This means that we don't have writable Data or BSS segments, and BSS 3534is not initialized as zero. To be able to get a C environment working 3535at all, we have to allocate at least a minimal stack. Implementation 3536options for this are defined and restricted by the CPU used: Some CPU 3537models provide on-chip memory (like the IMMR area on MPC8xx and 3538MPC826x processors), on others (parts of) the data cache can be 3539locked as (mis-) used as memory, etc. 3540 3541 Chris Hallinan posted a good summary of these issues to the 3542 u-boot-users mailing list: 3543 3544 Subject: RE: [U-Boot-Users] RE: More On Memory Bank x (nothingness)? 3545 From: "Chris Hallinan" <clh@net1plus.com> 3546 Date: Mon, 10 Feb 2003 16:43:46 -0500 (22:43 MET) 3547 ... 3548 3549 Correct me if I'm wrong, folks, but the way I understand it 3550 is this: Using DCACHE as initial RAM for Stack, etc, does not 3551 require any physical RAM backing up the cache. The cleverness 3552 is that the cache is being used as a temporary supply of 3553 necessary storage before the SDRAM controller is setup. It's 3554 beyond the scope of this list to expain the details, but you 3555 can see how this works by studying the cache architecture and 3556 operation in the architecture and processor-specific manuals. 3557 3558 OCM is On Chip Memory, which I believe the 405GP has 4K. It 3559 is another option for the system designer to use as an 3560 initial stack/ram area prior to SDRAM being available. Either 3561 option should work for you. Using CS 4 should be fine if your 3562 board designers haven't used it for something that would 3563 cause you grief during the initial boot! It is frequently not 3564 used. 3565 3566 CFG_INIT_RAM_ADDR should be somewhere that won't interfere 3567 with your processor/board/system design. The default value 3568 you will find in any recent u-boot distribution in 3569 walnut.h should work for you. I'd set it to a value larger 3570 than your SDRAM module. If you have a 64MB SDRAM module, set 3571 it above 400_0000. Just make sure your board has no resources 3572 that are supposed to respond to that address! That code in 3573 start.S has been around a while and should work as is when 3574 you get the config right. 3575 3576 -Chris Hallinan 3577 DS4.COM, Inc. 3578 3579It is essential to remember this, since it has some impact on the C 3580code for the initialization procedures: 3581 3582* Initialized global data (data segment) is read-only. Do not attempt 3583 to write it. 3584 3585* Do not use any unitialized global data (or implicitely initialized 3586 as zero data - BSS segment) at all - this is undefined, initiali- 3587 zation is performed later (when relocating to RAM). 3588 3589* Stack space is very limited. Avoid big data buffers or things like 3590 that. 3591 3592Having only the stack as writable memory limits means we cannot use 3593normal global data to share information beween the code. But it 3594turned out that the implementation of U-Boot can be greatly 3595simplified by making a global data structure (gd_t) available to all 3596functions. We could pass a pointer to this data as argument to _all_ 3597functions, but this would bloat the code. Instead we use a feature of 3598the GCC compiler (Global Register Variables) to share the data: we 3599place a pointer (gd) to the global data into a register which we 3600reserve for this purpose. 3601 3602When choosing a register for such a purpose we are restricted by the 3603relevant (E)ABI specifications for the current architecture, and by 3604GCC's implementation. 3605 3606For PowerPC, the following registers have specific use: 3607 R1: stack pointer 3608 R2: reserved for system use 3609 R3-R4: parameter passing and return values 3610 R5-R10: parameter passing 3611 R13: small data area pointer 3612 R30: GOT pointer 3613 R31: frame pointer 3614 3615 (U-Boot also uses R14 as internal GOT pointer.) 3616 3617 ==> U-Boot will use R2 to hold a pointer to the global data 3618 3619 Note: on PPC, we could use a static initializer (since the 3620 address of the global data structure is known at compile time), 3621 but it turned out that reserving a register results in somewhat 3622 smaller code - although the code savings are not that big (on 3623 average for all boards 752 bytes for the whole U-Boot image, 3624 624 text + 127 data). 3625 3626On Blackfin, the normal C ABI (except for P5) is followed as documented here: 3627 http://docs.blackfin.uclinux.org/doku.php?id=application_binary_interface 3628 3629 ==> U-Boot will use P5 to hold a pointer to the global data 3630 3631On ARM, the following registers are used: 3632 3633 R0: function argument word/integer result 3634 R1-R3: function argument word 3635 R9: GOT pointer 3636 R10: stack limit (used only if stack checking if enabled) 3637 R11: argument (frame) pointer 3638 R12: temporary workspace 3639 R13: stack pointer 3640 R14: link register 3641 R15: program counter 3642 3643 ==> U-Boot will use R8 to hold a pointer to the global data 3644 3645NOTE: DECLARE_GLOBAL_DATA_PTR must be used with file-global scope, 3646or current versions of GCC may "optimize" the code too much. 3647 3648Memory Management: 3649------------------ 3650 3651U-Boot runs in system state and uses physical addresses, i.e. the 3652MMU is not used either for address mapping nor for memory protection. 3653 3654The available memory is mapped to fixed addresses using the memory 3655controller. In this process, a contiguous block is formed for each 3656memory type (Flash, SDRAM, SRAM), even when it consists of several 3657physical memory banks. 3658 3659U-Boot is installed in the first 128 kB of the first Flash bank (on 3660TQM8xxL modules this is the range 0x40000000 ... 0x4001FFFF). After 3661booting and sizing and initializing DRAM, the code relocates itself 3662to the upper end of DRAM. Immediately below the U-Boot code some 3663memory is reserved for use by malloc() [see CFG_MALLOC_LEN 3664configuration setting]. Below that, a structure with global Board 3665Info data is placed, followed by the stack (growing downward). 3666 3667Additionally, some exception handler code is copied to the low 8 kB 3668of DRAM (0x00000000 ... 0x00001FFF). 3669 3670So a typical memory configuration with 16 MB of DRAM could look like 3671this: 3672 3673 0x0000 0000 Exception Vector code 3674 : 3675 0x0000 1FFF 3676 0x0000 2000 Free for Application Use 3677 : 3678 : 3679 3680 : 3681 : 3682 0x00FB FF20 Monitor Stack (Growing downward) 3683 0x00FB FFAC Board Info Data and permanent copy of global data 3684 0x00FC 0000 Malloc Arena 3685 : 3686 0x00FD FFFF 3687 0x00FE 0000 RAM Copy of Monitor Code 3688 ... eventually: LCD or video framebuffer 3689 ... eventually: pRAM (Protected RAM - unchanged by reset) 3690 0x00FF FFFF [End of RAM] 3691 3692 3693System Initialization: 3694---------------------- 3695 3696In the reset configuration, U-Boot starts at the reset entry point 3697(on most PowerPC systens at address 0x00000100). Because of the reset 3698configuration for CS0# this is a mirror of the onboard Flash memory. 3699To be able to re-map memory U-Boot then jumps to its link address. 3700To be able to implement the initialization code in C, a (small!) 3701initial stack is set up in the internal Dual Ported RAM (in case CPUs 3702which provide such a feature like MPC8xx or MPC8260), or in a locked 3703part of the data cache. After that, U-Boot initializes the CPU core, 3704the caches and the SIU. 3705 3706Next, all (potentially) available memory banks are mapped using a 3707preliminary mapping. For example, we put them on 512 MB boundaries 3708(multiples of 0x20000000: SDRAM on 0x00000000 and 0x20000000, Flash 3709on 0x40000000 and 0x60000000, SRAM on 0x80000000). Then UPM A is 3710programmed for SDRAM access. Using the temporary configuration, a 3711simple memory test is run that determines the size of the SDRAM 3712banks. 3713 3714When there is more than one SDRAM bank, and the banks are of 3715different size, the largest is mapped first. For equal size, the first 3716bank (CS2#) is mapped first. The first mapping is always for address 37170x00000000, with any additional banks following immediately to create 3718contiguous memory starting from 0. 3719 3720Then, the monitor installs itself at the upper end of the SDRAM area 3721and allocates memory for use by malloc() and for the global Board 3722Info data; also, the exception vector code is copied to the low RAM 3723pages, and the final stack is set up. 3724 3725Only after this relocation will you have a "normal" C environment; 3726until that you are restricted in several ways, mostly because you are 3727running from ROM, and because the code will have to be relocated to a 3728new address in RAM. 3729 3730 3731U-Boot Porting Guide: 3732---------------------- 3733 3734[Based on messages by Jerry Van Baren in the U-Boot-Users mailing 3735list, October 2002] 3736 3737 3738int main (int argc, char *argv[]) 3739{ 3740 sighandler_t no_more_time; 3741 3742 signal (SIGALRM, no_more_time); 3743 alarm (PROJECT_DEADLINE - toSec (3 * WEEK)); 3744 3745 if (available_money > available_manpower) { 3746 pay consultant to port U-Boot; 3747 return 0; 3748 } 3749 3750 Download latest U-Boot source; 3751 3752 Subscribe to u-boot-users mailing list; 3753 3754 if (clueless) { 3755 email ("Hi, I am new to U-Boot, how do I get started?"); 3756 } 3757 3758 while (learning) { 3759 Read the README file in the top level directory; 3760 Read http://www.denx.de/twiki/bin/view/DULG/Manual ; 3761 Read the source, Luke; 3762 } 3763 3764 if (available_money > toLocalCurrency ($2500)) { 3765 Buy a BDI2000; 3766 } else { 3767 Add a lot of aggravation and time; 3768 } 3769 3770 Create your own board support subdirectory; 3771 3772 Create your own board config file; 3773 3774 while (!running) { 3775 do { 3776 Add / modify source code; 3777 } until (compiles); 3778 Debug; 3779 if (clueless) 3780 email ("Hi, I am having problems..."); 3781 } 3782 Send patch file to Wolfgang; 3783 3784 return 0; 3785} 3786 3787void no_more_time (int sig) 3788{ 3789 hire_a_guru(); 3790} 3791 3792 3793Coding Standards: 3794----------------- 3795 3796All contributions to U-Boot should conform to the Linux kernel 3797coding style; see the file "Documentation/CodingStyle" and the script 3798"scripts/Lindent" in your Linux kernel source directory. In sources 3799originating from U-Boot a style corresponding to "Lindent -pcs" (adding 3800spaces before parameters to function calls) is actually used. 3801 3802Source files originating from a different project (for example the 3803MTD subsystem) are generally exempt from these guidelines and are not 3804reformated to ease subsequent migration to newer versions of those 3805sources. 3806 3807Please note that U-Boot is implemented in C (and to some small parts in 3808Assembler); no C++ is used, so please do not use C++ style comments (//) 3809in your code. 3810 3811Please also stick to the following formatting rules: 3812- remove any trailing white space 3813- use TAB characters for indentation, not spaces 3814- make sure NOT to use DOS '\r\n' line feeds 3815- do not add more than 2 empty lines to source files 3816- do not add trailing empty lines to source files 3817 3818Submissions which do not conform to the standards may be returned 3819with a request to reformat the changes. 3820 3821 3822Submitting Patches: 3823------------------- 3824 3825Since the number of patches for U-Boot is growing, we need to 3826establish some rules. Submissions which do not conform to these rules 3827may be rejected, even when they contain important and valuable stuff. 3828 3829Patches shall be sent to the u-boot-users mailing list. 3830 3831Please see http://www.denx.de/wiki/UBoot/Patches for details. 3832 3833When you send a patch, please include the following information with 3834it: 3835 3836* For bug fixes: a description of the bug and how your patch fixes 3837 this bug. Please try to include a way of demonstrating that the 3838 patch actually fixes something. 3839 3840* For new features: a description of the feature and your 3841 implementation. 3842 3843* A CHANGELOG entry as plaintext (separate from the patch) 3844 3845* For major contributions, your entry to the CREDITS file 3846 3847* When you add support for a new board, don't forget to add this 3848 board to the MAKEALL script, too. 3849 3850* If your patch adds new configuration options, don't forget to 3851 document these in the README file. 3852 3853* The patch itself. If you are using git (which is *strongly* 3854 recommended) you can easily generate the patch using the 3855 "git-format-patch". If you then use "git-send-email" to send it to 3856 the U-Boot mailing list, you will avoid most of the common problems 3857 with some other mail clients. 3858 3859 If you cannot use git, use "diff -purN OLD NEW". If your version of 3860 diff does not support these options, then get the latest version of 3861 GNU diff. 3862 3863 The current directory when running this command shall be the parent 3864 directory of the U-Boot source tree (i. e. please make sure that 3865 your patch includes sufficient directory information for the 3866 affected files). 3867 3868 We prefer patches as plain text. MIME attachments are discouraged, 3869 and compressed attachments must not be used. 3870 3871* If one logical set of modifications affects or creates several 3872 files, all these changes shall be submitted in a SINGLE patch file. 3873 3874* Changesets that contain different, unrelated modifications shall be 3875 submitted as SEPARATE patches, one patch per changeset. 3876 3877 3878Notes: 3879 3880* Before sending the patch, run the MAKEALL script on your patched 3881 source tree and make sure that no errors or warnings are reported 3882 for any of the boards. 3883 3884* Keep your modifications to the necessary minimum: A patch 3885 containing several unrelated changes or arbitrary reformats will be 3886 returned with a request to re-formatting / split it. 3887 3888* If you modify existing code, make sure that your new code does not 3889 add to the memory footprint of the code ;-) Small is beautiful! 3890 When adding new features, these should compile conditionally only 3891 (using #ifdef), and the resulting code with the new feature 3892 disabled must not need more memory than the old code without your 3893 modification. 3894 3895* Remember that there is a size limit of 40 kB per message on the 3896 u-boot-users mailing list. Bigger patches will be moderated. If 3897 they are reasonable and not bigger than 100 kB, they will be 3898 acknowledged. Even bigger patches should be avoided. 3899