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-built (and tested) images are available from 82ftp://ftp.denx.de/pub/u-boot/images/ 83 84 85Where we come from: 86=================== 87 88- start from 8xxrom sources 89- create PPCBoot project (http://sourceforge.net/projects/ppcboot) 90- clean up code 91- make it easier to add custom boards 92- make it possible to add other [PowerPC] CPUs 93- extend functions, especially: 94 * Provide extended interface to Linux boot loader 95 * S-Record download 96 * network boot 97 * PCMCIA / CompactFLash / ATA disk / SCSI ... boot 98- create ARMBoot project (http://sourceforge.net/projects/armboot) 99- add other CPU families (starting with ARM) 100- create U-Boot project (http://sourceforge.net/projects/u-boot) 101- current project page: see http://www.denx.de/wiki/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 CFG_RTC_DS1337_NOOSC - Turn off the OSC output for DS1337 693 694 Note that if the RTC uses I2C, then the I2C interface 695 must also be configured. See I2C Support, below. 696 697- Timestamp Support: 698 699 When CONFIG_TIMESTAMP is selected, the timestamp 700 (date and time) of an image is printed by image 701 commands like bootm or iminfo. This option is 702 automatically enabled when you select CONFIG_CMD_DATE . 703 704- Partition Support: 705 CONFIG_MAC_PARTITION and/or CONFIG_DOS_PARTITION 706 and/or CONFIG_ISO_PARTITION 707 708 If IDE or SCSI support is enabled (CONFIG_CMD_IDE or 709 CONFIG_CMD_SCSI) you must configure support for at 710 least one partition type as well. 711 712- IDE Reset method: 713 CONFIG_IDE_RESET_ROUTINE - this is defined in several 714 board configurations files but used nowhere! 715 716 CONFIG_IDE_RESET - is this is defined, IDE Reset will 717 be performed by calling the function 718 ide_set_reset(int reset) 719 which has to be defined in a board specific file 720 721- ATAPI Support: 722 CONFIG_ATAPI 723 724 Set this to enable ATAPI support. 725 726- LBA48 Support 727 CONFIG_LBA48 728 729 Set this to enable support for disks larger than 137GB 730 Also look at CFG_64BIT_LBA ,CFG_64BIT_VSPRINTF and CFG_64BIT_STRTOUL 731 Whithout these , LBA48 support uses 32bit variables and will 'only' 732 support disks up to 2.1TB. 733 734 CFG_64BIT_LBA: 735 When enabled, makes the IDE subsystem use 64bit sector addresses. 736 Default is 32bit. 737 738- SCSI Support: 739 At the moment only there is only support for the 740 SYM53C8XX SCSI controller; define 741 CONFIG_SCSI_SYM53C8XX to enable it. 742 743 CFG_SCSI_MAX_LUN [8], CFG_SCSI_MAX_SCSI_ID [7] and 744 CFG_SCSI_MAX_DEVICE [CFG_SCSI_MAX_SCSI_ID * 745 CFG_SCSI_MAX_LUN] can be adjusted to define the 746 maximum numbers of LUNs, SCSI ID's and target 747 devices. 748 CFG_SCSI_SYM53C8XX_CCF to fix clock timing (80Mhz) 749 750- NETWORK Support (PCI): 751 CONFIG_E1000 752 Support for Intel 8254x gigabit chips. 753 754 CONFIG_EEPRO100 755 Support for Intel 82557/82559/82559ER chips. 756 Optional CONFIG_EEPRO100_SROM_WRITE enables eeprom 757 write routine for first time initialisation. 758 759 CONFIG_TULIP 760 Support for Digital 2114x chips. 761 Optional CONFIG_TULIP_SELECT_MEDIA for board specific 762 modem chip initialisation (KS8761/QS6611). 763 764 CONFIG_NATSEMI 765 Support for National dp83815 chips. 766 767 CONFIG_NS8382X 768 Support for National dp8382[01] gigabit chips. 769 770- NETWORK Support (other): 771 772 CONFIG_DRIVER_LAN91C96 773 Support for SMSC's LAN91C96 chips. 774 775 CONFIG_LAN91C96_BASE 776 Define this to hold the physical address 777 of the LAN91C96's I/O space 778 779 CONFIG_LAN91C96_USE_32_BIT 780 Define this to enable 32 bit addressing 781 782 CONFIG_DRIVER_SMC91111 783 Support for SMSC's LAN91C111 chip 784 785 CONFIG_SMC91111_BASE 786 Define this to hold the physical address 787 of the device (I/O space) 788 789 CONFIG_SMC_USE_32_BIT 790 Define this if data bus is 32 bits 791 792 CONFIG_SMC_USE_IOFUNCS 793 Define this to use i/o functions instead of macros 794 (some hardware wont work with macros) 795 796- USB Support: 797 At the moment only the UHCI host controller is 798 supported (PIP405, MIP405, MPC5200); define 799 CONFIG_USB_UHCI to enable it. 800 define CONFIG_USB_KEYBOARD to enable the USB Keyboard 801 and define CONFIG_USB_STORAGE to enable the USB 802 storage devices. 803 Note: 804 Supported are USB Keyboards and USB Floppy drives 805 (TEAC FD-05PUB). 806 MPC5200 USB requires additional defines: 807 CONFIG_USB_CLOCK 808 for 528 MHz Clock: 0x0001bbbb 809 CONFIG_USB_CONFIG 810 for differential drivers: 0x00001000 811 for single ended drivers: 0x00005000 812 CFG_USB_EVENT_POLL 813 May be defined to allow interrupt polling 814 instead of using asynchronous interrupts 815 816- USB Device: 817 Define the below if you wish to use the USB console. 818 Once firmware is rebuilt from a serial console issue the 819 command "setenv stdin usbtty; setenv stdout usbtty" and 820 attach your usb cable. The Unix command "dmesg" should print 821 it has found a new device. The environment variable usbtty 822 can be set to gserial or cdc_acm to enable your device to 823 appear to a USB host as a Linux gserial device or a 824 Common Device Class Abstract Control Model serial device. 825 If you select usbtty = gserial you should be able to enumerate 826 a Linux host by 827 # modprobe usbserial vendor=0xVendorID product=0xProductID 828 else if using cdc_acm, simply setting the environment 829 variable usbtty to be cdc_acm should suffice. The following 830 might be defined in YourBoardName.h 831 832 CONFIG_USB_DEVICE 833 Define this to build a UDC device 834 835 CONFIG_USB_TTY 836 Define this to have a tty type of device available to 837 talk to the UDC device 838 839 CFG_CONSOLE_IS_IN_ENV 840 Define this if you want stdin, stdout &/or stderr to 841 be set to usbtty. 842 843 mpc8xx: 844 CFG_USB_EXTC_CLK 0xBLAH 845 Derive USB clock from external clock "blah" 846 - CFG_USB_EXTC_CLK 0x02 847 848 CFG_USB_BRG_CLK 0xBLAH 849 Derive USB clock from brgclk 850 - CFG_USB_BRG_CLK 0x04 851 852 If you have a USB-IF assigned VendorID then you may wish to 853 define your own vendor specific values either in BoardName.h 854 or directly in usbd_vendor_info.h. If you don't define 855 CONFIG_USBD_MANUFACTURER, CONFIG_USBD_PRODUCT_NAME, 856 CONFIG_USBD_VENDORID and CONFIG_USBD_PRODUCTID, then U-Boot 857 should pretend to be a Linux device to it's target host. 858 859 CONFIG_USBD_MANUFACTURER 860 Define this string as the name of your company for 861 - CONFIG_USBD_MANUFACTURER "my company" 862 863 CONFIG_USBD_PRODUCT_NAME 864 Define this string as the name of your product 865 - CONFIG_USBD_PRODUCT_NAME "acme usb device" 866 867 CONFIG_USBD_VENDORID 868 Define this as your assigned Vendor ID from the USB 869 Implementors Forum. This *must* be a genuine Vendor ID 870 to avoid polluting the USB namespace. 871 - CONFIG_USBD_VENDORID 0xFFFF 872 873 CONFIG_USBD_PRODUCTID 874 Define this as the unique Product ID 875 for your device 876 - CONFIG_USBD_PRODUCTID 0xFFFF 877 878 879- MMC Support: 880 The MMC controller on the Intel PXA is supported. To 881 enable this define CONFIG_MMC. The MMC can be 882 accessed from the boot prompt by mapping the device 883 to physical memory similar to flash. Command line is 884 enabled with CONFIG_CMD_MMC. The MMC driver also works with 885 the FAT fs. This is enabled with CONFIG_CMD_FAT. 886 887- Journaling Flash filesystem support: 888 CONFIG_JFFS2_NAND, CONFIG_JFFS2_NAND_OFF, CONFIG_JFFS2_NAND_SIZE, 889 CONFIG_JFFS2_NAND_DEV 890 Define these for a default partition on a NAND device 891 892 CFG_JFFS2_FIRST_SECTOR, 893 CFG_JFFS2_FIRST_BANK, CFG_JFFS2_NUM_BANKS 894 Define these for a default partition on a NOR device 895 896 CFG_JFFS_CUSTOM_PART 897 Define this to create an own partition. You have to provide a 898 function struct part_info* jffs2_part_info(int part_num) 899 900 If you define only one JFFS2 partition you may also want to 901 #define CFG_JFFS_SINGLE_PART 1 902 to disable the command chpart. This is the default when you 903 have not defined a custom partition 904 905- Keyboard Support: 906 CONFIG_ISA_KEYBOARD 907 908 Define this to enable standard (PC-Style) keyboard 909 support 910 911 CONFIG_I8042_KBD 912 Standard PC keyboard driver with US (is default) and 913 GERMAN key layout (switch via environment 'keymap=de') support. 914 Export function i8042_kbd_init, i8042_tstc and i8042_getc 915 for cfb_console. Supports cursor blinking. 916 917- Video support: 918 CONFIG_VIDEO 919 920 Define this to enable video support (for output to 921 video). 922 923 CONFIG_VIDEO_CT69000 924 925 Enable Chips & Technologies 69000 Video chip 926 927 CONFIG_VIDEO_SMI_LYNXEM 928 Enable Silicon Motion SMI 712/710/810 Video chip. The 929 video output is selected via environment 'videoout' 930 (1 = LCD and 2 = CRT). If videoout is undefined, CRT is 931 assumed. 932 933 For the CT69000 and SMI_LYNXEM drivers, videomode is 934 selected via environment 'videomode'. Two diferent ways 935 are possible: 936 - "videomode=num" 'num' is a standard LiLo mode numbers. 937 Following standard modes are supported (* is default): 938 939 Colors 640x480 800x600 1024x768 1152x864 1280x1024 940 -------------+--------------------------------------------- 941 8 bits | 0x301* 0x303 0x305 0x161 0x307 942 15 bits | 0x310 0x313 0x316 0x162 0x319 943 16 bits | 0x311 0x314 0x317 0x163 0x31A 944 24 bits | 0x312 0x315 0x318 ? 0x31B 945 -------------+--------------------------------------------- 946 (i.e. setenv videomode 317; saveenv; reset;) 947 948 - "videomode=bootargs" all the video parameters are parsed 949 from the bootargs. (See drivers/video/videomodes.c) 950 951 952 CONFIG_VIDEO_SED13806 953 Enable Epson SED13806 driver. This driver supports 8bpp 954 and 16bpp modes defined by CONFIG_VIDEO_SED13806_8BPP 955 or CONFIG_VIDEO_SED13806_16BPP 956 957- Keyboard Support: 958 CONFIG_KEYBOARD 959 960 Define this to enable a custom keyboard support. 961 This simply calls drv_keyboard_init() which must be 962 defined in your board-specific files. 963 The only board using this so far is RBC823. 964 965- LCD Support: CONFIG_LCD 966 967 Define this to enable LCD support (for output to LCD 968 display); also select one of the supported displays 969 by defining one of these: 970 971 CONFIG_NEC_NL6448AC33: 972 973 NEC NL6448AC33-18. Active, color, single scan. 974 975 CONFIG_NEC_NL6448BC20 976 977 NEC NL6448BC20-08. 6.5", 640x480. 978 Active, color, single scan. 979 980 CONFIG_NEC_NL6448BC33_54 981 982 NEC NL6448BC33-54. 10.4", 640x480. 983 Active, color, single scan. 984 985 CONFIG_SHARP_16x9 986 987 Sharp 320x240. Active, color, single scan. 988 It isn't 16x9, and I am not sure what it is. 989 990 CONFIG_SHARP_LQ64D341 991 992 Sharp LQ64D341 display, 640x480. 993 Active, color, single scan. 994 995 CONFIG_HLD1045 996 997 HLD1045 display, 640x480. 998 Active, color, single scan. 999 1000 CONFIG_OPTREX_BW 1001 1002 Optrex CBL50840-2 NF-FW 99 22 M5 1003 or 1004 Hitachi LMG6912RPFC-00T 1005 or 1006 Hitachi SP14Q002 1007 1008 320x240. Black & white. 1009 1010 Normally display is black on white background; define 1011 CFG_WHITE_ON_BLACK to get it inverted. 1012 1013- Splash Screen Support: CONFIG_SPLASH_SCREEN 1014 1015 If this option is set, the environment is checked for 1016 a variable "splashimage". If found, the usual display 1017 of logo, copyright and system information on the LCD 1018 is suppressed and the BMP image at the address 1019 specified in "splashimage" is loaded instead. The 1020 console is redirected to the "nulldev", too. This 1021 allows for a "silent" boot where a splash screen is 1022 loaded very quickly after power-on. 1023 1024- Gzip compressed BMP image support: CONFIG_VIDEO_BMP_GZIP 1025 1026 If this option is set, additionally to standard BMP 1027 images, gzipped BMP images can be displayed via the 1028 splashscreen support or the bmp command. 1029 1030- Compression support: 1031 CONFIG_BZIP2 1032 1033 If this option is set, support for bzip2 compressed 1034 images is included. If not, only uncompressed and gzip 1035 compressed images are supported. 1036 1037 NOTE: the bzip2 algorithm requires a lot of RAM, so 1038 the malloc area (as defined by CFG_MALLOC_LEN) should 1039 be at least 4MB. 1040 1041- MII/PHY support: 1042 CONFIG_PHY_ADDR 1043 1044 The address of PHY on MII bus. 1045 1046 CONFIG_PHY_CLOCK_FREQ (ppc4xx) 1047 1048 The clock frequency of the MII bus 1049 1050 CONFIG_PHY_GIGE 1051 1052 If this option is set, support for speed/duplex 1053 detection of Gigabit PHY is included. 1054 1055 CONFIG_PHY_RESET_DELAY 1056 1057 Some PHY like Intel LXT971A need extra delay after 1058 reset before any MII register access is possible. 1059 For such PHY, set this option to the usec delay 1060 required. (minimum 300usec for LXT971A) 1061 1062 CONFIG_PHY_CMD_DELAY (ppc4xx) 1063 1064 Some PHY like Intel LXT971A need extra delay after 1065 command issued before MII status register can be read 1066 1067- Ethernet address: 1068 CONFIG_ETHADDR 1069 CONFIG_ETH2ADDR 1070 CONFIG_ETH3ADDR 1071 1072 Define a default value for ethernet address to use 1073 for the respective ethernet interface, in case this 1074 is not determined automatically. 1075 1076- IP address: 1077 CONFIG_IPADDR 1078 1079 Define a default value for the IP address to use for 1080 the default ethernet interface, in case this is not 1081 determined through e.g. bootp. 1082 1083- Server IP address: 1084 CONFIG_SERVERIP 1085 1086 Defines a default value for theIP address of a TFTP 1087 server to contact when using the "tftboot" command. 1088 1089- Multicast TFTP Mode: 1090 CONFIG_MCAST_TFTP 1091 1092 Defines whether you want to support multicast TFTP as per 1093 rfc-2090; for example to work with atftp. Lets lots of targets 1094 tftp down the same boot image concurrently. Note: the ethernet 1095 driver in use must provide a function: mcast() to join/leave a 1096 multicast group. 1097 1098 CONFIG_BOOTP_RANDOM_DELAY 1099- BOOTP Recovery Mode: 1100 CONFIG_BOOTP_RANDOM_DELAY 1101 1102 If you have many targets in a network that try to 1103 boot using BOOTP, you may want to avoid that all 1104 systems send out BOOTP requests at precisely the same 1105 moment (which would happen for instance at recovery 1106 from a power failure, when all systems will try to 1107 boot, thus flooding the BOOTP server. Defining 1108 CONFIG_BOOTP_RANDOM_DELAY causes a random delay to be 1109 inserted before sending out BOOTP requests. The 1110 following delays are inserted then: 1111 1112 1st BOOTP request: delay 0 ... 1 sec 1113 2nd BOOTP request: delay 0 ... 2 sec 1114 3rd BOOTP request: delay 0 ... 4 sec 1115 4th and following 1116 BOOTP requests: delay 0 ... 8 sec 1117 1118- DHCP Advanced Options: 1119 You can fine tune the DHCP functionality by defining 1120 CONFIG_BOOTP_* symbols: 1121 1122 CONFIG_BOOTP_SUBNETMASK 1123 CONFIG_BOOTP_GATEWAY 1124 CONFIG_BOOTP_HOSTNAME 1125 CONFIG_BOOTP_NISDOMAIN 1126 CONFIG_BOOTP_BOOTPATH 1127 CONFIG_BOOTP_BOOTFILESIZE 1128 CONFIG_BOOTP_DNS 1129 CONFIG_BOOTP_DNS2 1130 CONFIG_BOOTP_SEND_HOSTNAME 1131 CONFIG_BOOTP_NTPSERVER 1132 CONFIG_BOOTP_TIMEOFFSET 1133 CONFIG_BOOTP_VENDOREX 1134 1135 CONFIG_BOOTP_SERVERIP - TFTP server will be the serverip 1136 environment variable, not the BOOTP server. 1137 1138 CONFIG_BOOTP_DNS2 - If a DHCP client requests the DNS 1139 serverip from a DHCP server, it is possible that more 1140 than one DNS serverip is offered to the client. 1141 If CONFIG_BOOTP_DNS2 is enabled, the secondary DNS 1142 serverip will be stored in the additional environment 1143 variable "dnsip2". The first DNS serverip is always 1144 stored in the variable "dnsip", when CONFIG_BOOTP_DNS 1145 is defined. 1146 1147 CONFIG_BOOTP_SEND_HOSTNAME - Some DHCP servers are capable 1148 to do a dynamic update of a DNS server. To do this, they 1149 need the hostname of the DHCP requester. 1150 If CONFIG_BOOTP_SEND_HOSTNAME is defined, the content 1151 of the "hostname" environment variable is passed as 1152 option 12 to the DHCP server. 1153 1154 - CDP Options: 1155 CONFIG_CDP_DEVICE_ID 1156 1157 The device id used in CDP trigger frames. 1158 1159 CONFIG_CDP_DEVICE_ID_PREFIX 1160 1161 A two character string which is prefixed to the MAC address 1162 of the device. 1163 1164 CONFIG_CDP_PORT_ID 1165 1166 A printf format string which contains the ascii name of 1167 the port. Normally is set to "eth%d" which sets 1168 eth0 for the first ethernet, eth1 for the second etc. 1169 1170 CONFIG_CDP_CAPABILITIES 1171 1172 A 32bit integer which indicates the device capabilities; 1173 0x00000010 for a normal host which does not forwards. 1174 1175 CONFIG_CDP_VERSION 1176 1177 An ascii string containing the version of the software. 1178 1179 CONFIG_CDP_PLATFORM 1180 1181 An ascii string containing the name of the platform. 1182 1183 CONFIG_CDP_TRIGGER 1184 1185 A 32bit integer sent on the trigger. 1186 1187 CONFIG_CDP_POWER_CONSUMPTION 1188 1189 A 16bit integer containing the power consumption of the 1190 device in .1 of milliwatts. 1191 1192 CONFIG_CDP_APPLIANCE_VLAN_TYPE 1193 1194 A byte containing the id of the VLAN. 1195 1196- Status LED: CONFIG_STATUS_LED 1197 1198 Several configurations allow to display the current 1199 status using a LED. For instance, the LED will blink 1200 fast while running U-Boot code, stop blinking as 1201 soon as a reply to a BOOTP request was received, and 1202 start blinking slow once the Linux kernel is running 1203 (supported by a status LED driver in the Linux 1204 kernel). Defining CONFIG_STATUS_LED enables this 1205 feature in U-Boot. 1206 1207- CAN Support: CONFIG_CAN_DRIVER 1208 1209 Defining CONFIG_CAN_DRIVER enables CAN driver support 1210 on those systems that support this (optional) 1211 feature, like the TQM8xxL modules. 1212 1213- I2C Support: CONFIG_HARD_I2C | CONFIG_SOFT_I2C 1214 1215 These enable I2C serial bus commands. Defining either of 1216 (but not both of) CONFIG_HARD_I2C or CONFIG_SOFT_I2C will 1217 include the appropriate I2C driver for the selected cpu. 1218 1219 This will allow you to use i2c commands at the u-boot 1220 command line (as long as you set CONFIG_CMD_I2C in 1221 CONFIG_COMMANDS) and communicate with i2c based realtime 1222 clock chips. See common/cmd_i2c.c for a description of the 1223 command line interface. 1224 1225 CONFIG_I2C_CMD_TREE is a recommended option that places 1226 all I2C commands under a single 'i2c' root command. The 1227 older 'imm', 'imd', 'iprobe' etc. commands are considered 1228 deprecated and may disappear in the future. 1229 1230 CONFIG_HARD_I2C selects a hardware I2C controller. 1231 1232 CONFIG_SOFT_I2C configures u-boot to use a software (aka 1233 bit-banging) driver instead of CPM or similar hardware 1234 support for I2C. 1235 1236 There are several other quantities that must also be 1237 defined when you define CONFIG_HARD_I2C or CONFIG_SOFT_I2C. 1238 1239 In both cases you will need to define CFG_I2C_SPEED 1240 to be the frequency (in Hz) at which you wish your i2c bus 1241 to run and CFG_I2C_SLAVE to be the address of this node (ie 1242 the cpu's i2c node address). 1243 1244 Now, the u-boot i2c code for the mpc8xx (cpu/mpc8xx/i2c.c) 1245 sets the cpu up as a master node and so its address should 1246 therefore be cleared to 0 (See, eg, MPC823e User's Manual 1247 p.16-473). So, set CFG_I2C_SLAVE to 0. 1248 1249 That's all that's required for CONFIG_HARD_I2C. 1250 1251 If you use the software i2c interface (CONFIG_SOFT_I2C) 1252 then the following macros need to be defined (examples are 1253 from include/configs/lwmon.h): 1254 1255 I2C_INIT 1256 1257 (Optional). Any commands necessary to enable the I2C 1258 controller or configure ports. 1259 1260 eg: #define I2C_INIT (immr->im_cpm.cp_pbdir |= PB_SCL) 1261 1262 I2C_PORT 1263 1264 (Only for MPC8260 CPU). The I/O port to use (the code 1265 assumes both bits are on the same port). Valid values 1266 are 0..3 for ports A..D. 1267 1268 I2C_ACTIVE 1269 1270 The code necessary to make the I2C data line active 1271 (driven). If the data line is open collector, this 1272 define can be null. 1273 1274 eg: #define I2C_ACTIVE (immr->im_cpm.cp_pbdir |= PB_SDA) 1275 1276 I2C_TRISTATE 1277 1278 The code necessary to make the I2C data line tri-stated 1279 (inactive). If the data line is open collector, this 1280 define can be null. 1281 1282 eg: #define I2C_TRISTATE (immr->im_cpm.cp_pbdir &= ~PB_SDA) 1283 1284 I2C_READ 1285 1286 Code that returns TRUE if the I2C data line is high, 1287 FALSE if it is low. 1288 1289 eg: #define I2C_READ ((immr->im_cpm.cp_pbdat & PB_SDA) != 0) 1290 1291 I2C_SDA(bit) 1292 1293 If <bit> is TRUE, sets the I2C data line high. If it 1294 is FALSE, it clears it (low). 1295 1296 eg: #define I2C_SDA(bit) \ 1297 if(bit) immr->im_cpm.cp_pbdat |= PB_SDA; \ 1298 else immr->im_cpm.cp_pbdat &= ~PB_SDA 1299 1300 I2C_SCL(bit) 1301 1302 If <bit> is TRUE, sets the I2C clock line high. If it 1303 is FALSE, it clears it (low). 1304 1305 eg: #define I2C_SCL(bit) \ 1306 if(bit) immr->im_cpm.cp_pbdat |= PB_SCL; \ 1307 else immr->im_cpm.cp_pbdat &= ~PB_SCL 1308 1309 I2C_DELAY 1310 1311 This delay is invoked four times per clock cycle so this 1312 controls the rate of data transfer. The data rate thus 1313 is 1 / (I2C_DELAY * 4). Often defined to be something 1314 like: 1315 1316 #define I2C_DELAY udelay(2) 1317 1318 CFG_I2C_INIT_BOARD 1319 1320 When a board is reset during an i2c bus transfer 1321 chips might think that the current transfer is still 1322 in progress. On some boards it is possible to access 1323 the i2c SCLK line directly, either by using the 1324 processor pin as a GPIO or by having a second pin 1325 connected to the bus. If this option is defined a 1326 custom i2c_init_board() routine in boards/xxx/board.c 1327 is run early in the boot sequence. 1328 1329 CONFIG_I2CFAST (PPC405GP|PPC405EP only) 1330 1331 This option enables configuration of bi_iic_fast[] flags 1332 in u-boot bd_info structure based on u-boot environment 1333 variable "i2cfast". (see also i2cfast) 1334 1335 CONFIG_I2C_MULTI_BUS 1336 1337 This option allows the use of multiple I2C buses, each of which 1338 must have a controller. At any point in time, only one bus is 1339 active. To switch to a different bus, use the 'i2c dev' command. 1340 Note that bus numbering is zero-based. 1341 1342 CFG_I2C_NOPROBES 1343 1344 This option specifies a list of I2C devices that will be skipped 1345 when the 'i2c probe' command is issued (or 'iprobe' using the legacy 1346 command). If CONFIG_I2C_MULTI_BUS is set, specify a list of bus-device 1347 pairs. Otherwise, specify a 1D array of device addresses 1348 1349 e.g. 1350 #undef CONFIG_I2C_MULTI_BUS 1351 #define CFG_I2C_NOPROBES {0x50,0x68} 1352 1353 will skip addresses 0x50 and 0x68 on a board with one I2C bus 1354 1355 #define CONFIG_I2C_MULTI_BUS 1356 #define CFG_I2C_MULTI_NOPROBES {{0,0x50},{0,0x68},{1,0x54}} 1357 1358 will skip addresses 0x50 and 0x68 on bus 0 and address 0x54 on bus 1 1359 1360 CFG_SPD_BUS_NUM 1361 1362 If defined, then this indicates the I2C bus number for DDR SPD. 1363 If not defined, then U-Boot assumes that SPD is on I2C bus 0. 1364 1365 CFG_RTC_BUS_NUM 1366 1367 If defined, then this indicates the I2C bus number for the RTC. 1368 If not defined, then U-Boot assumes that RTC is on I2C bus 0. 1369 1370 CFG_DTT_BUS_NUM 1371 1372 If defined, then this indicates the I2C bus number for the DTT. 1373 If not defined, then U-Boot assumes that DTT is on I2C bus 0. 1374 1375 CONFIG_FSL_I2C 1376 1377 Define this option if you want to use Freescale's I2C driver in 1378 drivers/i2c/fsl_i2c.c. 1379 1380 1381- SPI Support: CONFIG_SPI 1382 1383 Enables SPI driver (so far only tested with 1384 SPI EEPROM, also an instance works with Crystal A/D and 1385 D/As on the SACSng board) 1386 1387 CONFIG_SPI_X 1388 1389 Enables extended (16-bit) SPI EEPROM addressing. 1390 (symmetrical to CONFIG_I2C_X) 1391 1392 CONFIG_SOFT_SPI 1393 1394 Enables a software (bit-bang) SPI driver rather than 1395 using hardware support. This is a general purpose 1396 driver that only requires three general I/O port pins 1397 (two outputs, one input) to function. If this is 1398 defined, the board configuration must define several 1399 SPI configuration items (port pins to use, etc). For 1400 an example, see include/configs/sacsng.h. 1401 1402 CONFIG_HARD_SPI 1403 1404 Enables a hardware SPI driver for general-purpose reads 1405 and writes. As with CONFIG_SOFT_SPI, the board configuration 1406 must define a list of chip-select function pointers. 1407 Currently supported on some MPC8xxx processors. For an 1408 example, see include/configs/mpc8349emds.h. 1409 1410- FPGA Support: CONFIG_FPGA 1411 1412 Enables FPGA subsystem. 1413 1414 CONFIG_FPGA_<vendor> 1415 1416 Enables support for specific chip vendors. 1417 (ALTERA, XILINX) 1418 1419 CONFIG_FPGA_<family> 1420 1421 Enables support for FPGA family. 1422 (SPARTAN2, SPARTAN3, VIRTEX2, CYCLONE2, ACEX1K, ACEX) 1423 1424 CONFIG_FPGA_COUNT 1425 1426 Specify the number of FPGA devices to support. 1427 1428 CFG_FPGA_PROG_FEEDBACK 1429 1430 Enable printing of hash marks during FPGA configuration. 1431 1432 CFG_FPGA_CHECK_BUSY 1433 1434 Enable checks on FPGA configuration interface busy 1435 status by the configuration function. This option 1436 will require a board or device specific function to 1437 be written. 1438 1439 CONFIG_FPGA_DELAY 1440 1441 If defined, a function that provides delays in the FPGA 1442 configuration driver. 1443 1444 CFG_FPGA_CHECK_CTRLC 1445 Allow Control-C to interrupt FPGA configuration 1446 1447 CFG_FPGA_CHECK_ERROR 1448 1449 Check for configuration errors during FPGA bitfile 1450 loading. For example, abort during Virtex II 1451 configuration if the INIT_B line goes low (which 1452 indicated a CRC error). 1453 1454 CFG_FPGA_WAIT_INIT 1455 1456 Maximum time to wait for the INIT_B line to deassert 1457 after PROB_B has been deasserted during a Virtex II 1458 FPGA configuration sequence. The default time is 500 1459 mS. 1460 1461 CFG_FPGA_WAIT_BUSY 1462 1463 Maximum time to wait for BUSY to deassert during 1464 Virtex II FPGA configuration. The default is 5 mS. 1465 1466 CFG_FPGA_WAIT_CONFIG 1467 1468 Time to wait after FPGA configuration. The default is 1469 200 mS. 1470 1471- Configuration Management: 1472 CONFIG_IDENT_STRING 1473 1474 If defined, this string will be added to the U-Boot 1475 version information (U_BOOT_VERSION) 1476 1477- Vendor Parameter Protection: 1478 1479 U-Boot considers the values of the environment 1480 variables "serial#" (Board Serial Number) and 1481 "ethaddr" (Ethernet Address) to be parameters that 1482 are set once by the board vendor / manufacturer, and 1483 protects these variables from casual modification by 1484 the user. Once set, these variables are read-only, 1485 and write or delete attempts are rejected. You can 1486 change this behviour: 1487 1488 If CONFIG_ENV_OVERWRITE is #defined in your config 1489 file, the write protection for vendor parameters is 1490 completely disabled. Anybody can change or delete 1491 these parameters. 1492 1493 Alternatively, if you #define _both_ CONFIG_ETHADDR 1494 _and_ CONFIG_OVERWRITE_ETHADDR_ONCE, a default 1495 ethernet address is installed in the environment, 1496 which can be changed exactly ONCE by the user. [The 1497 serial# is unaffected by this, i. e. it remains 1498 read-only.] 1499 1500- Protected RAM: 1501 CONFIG_PRAM 1502 1503 Define this variable to enable the reservation of 1504 "protected RAM", i. e. RAM which is not overwritten 1505 by U-Boot. Define CONFIG_PRAM to hold the number of 1506 kB you want to reserve for pRAM. You can overwrite 1507 this default value by defining an environment 1508 variable "pram" to the number of kB you want to 1509 reserve. Note that the board info structure will 1510 still show the full amount of RAM. If pRAM is 1511 reserved, a new environment variable "mem" will 1512 automatically be defined to hold the amount of 1513 remaining RAM in a form that can be passed as boot 1514 argument to Linux, for instance like that: 1515 1516 setenv bootargs ... mem=\${mem} 1517 saveenv 1518 1519 This way you can tell Linux not to use this memory, 1520 either, which results in a memory region that will 1521 not be affected by reboots. 1522 1523 *WARNING* If your board configuration uses automatic 1524 detection of the RAM size, you must make sure that 1525 this memory test is non-destructive. So far, the 1526 following board configurations are known to be 1527 "pRAM-clean": 1528 1529 ETX094, IVMS8, IVML24, SPD8xx, TQM8xxL, 1530 HERMES, IP860, RPXlite, LWMON, LANTEC, 1531 PCU_E, FLAGADM, TQM8260 1532 1533- Error Recovery: 1534 CONFIG_PANIC_HANG 1535 1536 Define this variable to stop the system in case of a 1537 fatal error, so that you have to reset it manually. 1538 This is probably NOT a good idea for an embedded 1539 system where you want to system to reboot 1540 automatically as fast as possible, but it may be 1541 useful during development since you can try to debug 1542 the conditions that lead to the situation. 1543 1544 CONFIG_NET_RETRY_COUNT 1545 1546 This variable defines the number of retries for 1547 network operations like ARP, RARP, TFTP, or BOOTP 1548 before giving up the operation. If not defined, a 1549 default value of 5 is used. 1550 1551- Command Interpreter: 1552 CONFIG_AUTO_COMPLETE 1553 1554 Enable auto completion of commands using TAB. 1555 1556 Note that this feature has NOT been implemented yet 1557 for the "hush" shell. 1558 1559 1560 CFG_HUSH_PARSER 1561 1562 Define this variable to enable the "hush" shell (from 1563 Busybox) as command line interpreter, thus enabling 1564 powerful command line syntax like 1565 if...then...else...fi conditionals or `&&' and '||' 1566 constructs ("shell scripts"). 1567 1568 If undefined, you get the old, much simpler behaviour 1569 with a somewhat smaller memory footprint. 1570 1571 1572 CFG_PROMPT_HUSH_PS2 1573 1574 This defines the secondary prompt string, which is 1575 printed when the command interpreter needs more input 1576 to complete a command. Usually "> ". 1577 1578 Note: 1579 1580 In the current implementation, the local variables 1581 space and global environment variables space are 1582 separated. Local variables are those you define by 1583 simply typing `name=value'. To access a local 1584 variable later on, you have write `$name' or 1585 `${name}'; to execute the contents of a variable 1586 directly type `$name' at the command prompt. 1587 1588 Global environment variables are those you use 1589 setenv/printenv to work with. To run a command stored 1590 in such a variable, you need to use the run command, 1591 and you must not use the '$' sign to access them. 1592 1593 To store commands and special characters in a 1594 variable, please use double quotation marks 1595 surrounding the whole text of the variable, instead 1596 of the backslashes before semicolons and special 1597 symbols. 1598 1599- Commandline Editing and History: 1600 CONFIG_CMDLINE_EDITING 1601 1602 Enable editiong and History functions for interactive 1603 commandline input operations 1604 1605- Default Environment: 1606 CONFIG_EXTRA_ENV_SETTINGS 1607 1608 Define this to contain any number of null terminated 1609 strings (variable = value pairs) that will be part of 1610 the default environment compiled into the boot image. 1611 1612 For example, place something like this in your 1613 board's config file: 1614 1615 #define CONFIG_EXTRA_ENV_SETTINGS \ 1616 "myvar1=value1\0" \ 1617 "myvar2=value2\0" 1618 1619 Warning: This method is based on knowledge about the 1620 internal format how the environment is stored by the 1621 U-Boot code. This is NOT an official, exported 1622 interface! Although it is unlikely that this format 1623 will change soon, there is no guarantee either. 1624 You better know what you are doing here. 1625 1626 Note: overly (ab)use of the default environment is 1627 discouraged. Make sure to check other ways to preset 1628 the environment like the autoscript function or the 1629 boot command first. 1630 1631- DataFlash Support: 1632 CONFIG_HAS_DATAFLASH 1633 1634 Defining this option enables DataFlash features and 1635 allows to read/write in Dataflash via the standard 1636 commands cp, md... 1637 1638- SystemACE Support: 1639 CONFIG_SYSTEMACE 1640 1641 Adding this option adds support for Xilinx SystemACE 1642 chips attached via some sort of local bus. The address 1643 of the chip must alsh be defined in the 1644 CFG_SYSTEMACE_BASE macro. For example: 1645 1646 #define CONFIG_SYSTEMACE 1647 #define CFG_SYSTEMACE_BASE 0xf0000000 1648 1649 When SystemACE support is added, the "ace" device type 1650 becomes available to the fat commands, i.e. fatls. 1651 1652- TFTP Fixed UDP Port: 1653 CONFIG_TFTP_PORT 1654 1655 If this is defined, the environment variable tftpsrcp 1656 is used to supply the TFTP UDP source port value. 1657 If tftpsrcp isn't defined, the normal pseudo-random port 1658 number generator is used. 1659 1660 Also, the environment variable tftpdstp is used to supply 1661 the TFTP UDP destination port value. If tftpdstp isn't 1662 defined, the normal port 69 is used. 1663 1664 The purpose for tftpsrcp is to allow a TFTP server to 1665 blindly start the TFTP transfer using the pre-configured 1666 target IP address and UDP port. This has the effect of 1667 "punching through" the (Windows XP) firewall, allowing 1668 the remainder of the TFTP transfer to proceed normally. 1669 A better solution is to properly configure the firewall, 1670 but sometimes that is not allowed. 1671 1672- Show boot progress: 1673 CONFIG_SHOW_BOOT_PROGRESS 1674 1675 Defining this option allows to add some board- 1676 specific code (calling a user-provided function 1677 "show_boot_progress(int)") that enables you to show 1678 the system's boot progress on some display (for 1679 example, some LED's) on your board. At the moment, 1680 the following checkpoints are implemented: 1681 1682Legacy uImage format: 1683 1684 Arg Where When 1685 1 common/cmd_bootm.c before attempting to boot an image 1686 -1 common/cmd_bootm.c Image header has bad magic number 1687 2 common/cmd_bootm.c Image header has correct magic number 1688 -2 common/cmd_bootm.c Image header has bad checksum 1689 3 common/cmd_bootm.c Image header has correct checksum 1690 -3 common/cmd_bootm.c Image data has bad checksum 1691 4 common/cmd_bootm.c Image data has correct checksum 1692 -4 common/cmd_bootm.c Image is for unsupported architecture 1693 5 common/cmd_bootm.c Architecture check OK 1694 -5 common/cmd_bootm.c Wrong Image Type (not kernel, multi) 1695 6 common/cmd_bootm.c Image Type check OK 1696 -6 common/cmd_bootm.c gunzip uncompression error 1697 -7 common/cmd_bootm.c Unimplemented compression type 1698 7 common/cmd_bootm.c Uncompression OK 1699 8 common/cmd_bootm.c No uncompress/copy overwrite error 1700 -9 common/cmd_bootm.c Unsupported OS (not Linux, BSD, VxWorks, QNX) 1701 1702 9 common/image.c Start initial ramdisk verification 1703 -10 common/image.c Ramdisk header has bad magic number 1704 -11 common/image.c Ramdisk header has bad checksum 1705 10 common/image.c Ramdisk header is OK 1706 -12 common/image.c Ramdisk data has bad checksum 1707 11 common/image.c Ramdisk data has correct checksum 1708 12 common/image.c Ramdisk verification complete, start loading 1709 -13 common/image.c Wrong Image Type (not PPC Linux Ramdisk) 1710 13 common/image.c Start multifile image verification 1711 14 common/image.c No initial ramdisk, no multifile, continue. 1712 1713 15 lib_<arch>/bootm.c All preparation done, transferring control to OS 1714 1715 -30 lib_ppc/board.c Fatal error, hang the system 1716 -31 post/post.c POST test failed, detected by post_output_backlog() 1717 -32 post/post.c POST test failed, detected by post_run_single() 1718 1719 34 common/cmd_doc.c before loading a Image from a DOC device 1720 -35 common/cmd_doc.c Bad usage of "doc" command 1721 35 common/cmd_doc.c correct usage of "doc" command 1722 -36 common/cmd_doc.c No boot device 1723 36 common/cmd_doc.c correct boot device 1724 -37 common/cmd_doc.c Unknown Chip ID on boot device 1725 37 common/cmd_doc.c correct chip ID found, device available 1726 -38 common/cmd_doc.c Read Error on boot device 1727 38 common/cmd_doc.c reading Image header from DOC device OK 1728 -39 common/cmd_doc.c Image header has bad magic number 1729 39 common/cmd_doc.c Image header has correct magic number 1730 -40 common/cmd_doc.c Error reading Image from DOC device 1731 40 common/cmd_doc.c Image header has correct magic number 1732 41 common/cmd_ide.c before loading a Image from a IDE device 1733 -42 common/cmd_ide.c Bad usage of "ide" command 1734 42 common/cmd_ide.c correct usage of "ide" command 1735 -43 common/cmd_ide.c No boot device 1736 43 common/cmd_ide.c boot device found 1737 -44 common/cmd_ide.c Device not available 1738 44 common/cmd_ide.c Device available 1739 -45 common/cmd_ide.c wrong partition selected 1740 45 common/cmd_ide.c partition selected 1741 -46 common/cmd_ide.c Unknown partition table 1742 46 common/cmd_ide.c valid partition table found 1743 -47 common/cmd_ide.c Invalid partition type 1744 47 common/cmd_ide.c correct partition type 1745 -48 common/cmd_ide.c Error reading Image Header on boot device 1746 48 common/cmd_ide.c reading Image Header from IDE device OK 1747 -49 common/cmd_ide.c Image header has bad magic number 1748 49 common/cmd_ide.c Image header has correct magic number 1749 -50 common/cmd_ide.c Image header has bad checksum 1750 50 common/cmd_ide.c Image header has correct checksum 1751 -51 common/cmd_ide.c Error reading Image from IDE device 1752 51 common/cmd_ide.c reading Image from IDE device OK 1753 52 common/cmd_nand.c before loading a Image from a NAND device 1754 -53 common/cmd_nand.c Bad usage of "nand" command 1755 53 common/cmd_nand.c correct usage of "nand" command 1756 -54 common/cmd_nand.c No boot device 1757 54 common/cmd_nand.c boot device found 1758 -55 common/cmd_nand.c Unknown Chip ID on boot device 1759 55 common/cmd_nand.c correct chip ID found, device available 1760 -56 common/cmd_nand.c Error reading Image Header on boot device 1761 56 common/cmd_nand.c reading Image Header from NAND device OK 1762 -57 common/cmd_nand.c Image header has bad magic number 1763 57 common/cmd_nand.c Image header has correct magic number 1764 -58 common/cmd_nand.c Error reading Image from NAND device 1765 58 common/cmd_nand.c reading Image from NAND device OK 1766 1767 -60 common/env_common.c Environment has a bad CRC, using default 1768 1769 64 net/eth.c starting with Ethernetconfiguration. 1770 -64 net/eth.c no Ethernet found. 1771 65 net/eth.c Ethernet found. 1772 1773 -80 common/cmd_net.c usage wrong 1774 80 common/cmd_net.c before calling NetLoop() 1775 -81 common/cmd_net.c some error in NetLoop() occured 1776 81 common/cmd_net.c NetLoop() back without error 1777 -82 common/cmd_net.c size == 0 (File with size 0 loaded) 1778 82 common/cmd_net.c trying automatic boot 1779 83 common/cmd_net.c running autoscript 1780 -83 common/cmd_net.c some error in automatic boot or autoscript 1781 84 common/cmd_net.c end without errors 1782 1783FIT uImage format: 1784 1785 Arg Where When 1786 100 common/cmd_bootm.c Kernel FIT Image has correct format 1787 -100 common/cmd_bootm.c Kernel FIT Image has incorrect format 1788 101 common/cmd_bootm.c No Kernel subimage unit name, using configuration 1789 -101 common/cmd_bootm.c Can't get configuration for kernel subimage 1790 102 common/cmd_bootm.c Kernel unit name specified 1791 -103 common/cmd_bootm.c Can't get kernel subimage node offset 1792 103 common/cmd_bootm.c Found configuration node 1793 104 common/cmd_bootm.c Got kernel subimage node offset 1794 -104 common/cmd_bootm.c Kernel subimage hash verification failed 1795 105 common/cmd_bootm.c Kernel subimage hash verification OK 1796 -105 common/cmd_bootm.c Kernel subimage is for unsupported architecture 1797 106 common/cmd_bootm.c Architecture check OK 1798 -106 common/cmd_bootm.c Kernel subimage has wrong typea 1799 107 common/cmd_bootm.c Kernel subimge type OK 1800 -107 common/cmd_bootm.c Can't get kernel subimage data/size 1801 108 common/cmd_bootm.c Got kernel subimage data/size 1802 -108 common/cmd_bootm.c Wrong image type (not legacy, FIT) 1803 -109 common/cmd_bootm.c Can't get kernel subimage type 1804 -110 common/cmd_bootm.c Can't get kernel subimage comp 1805 -111 common/cmd_bootm.c Can't get kernel subimage os 1806 -112 common/cmd_bootm.c Can't get kernel subimage load address 1807 -113 common/cmd_bootm.c Image uncompress/copy overwrite error 1808 1809 120 common/image.c Start initial ramdisk verification 1810 -120 common/image.c Ramdisk FIT image has incorrect format 1811 121 common/image.c Ramdisk FIT image has correct format 1812 122 common/image.c No Ramdisk subimage unit name, using configuration 1813 -122 common/image.c Can't get configuration for ramdisk subimage 1814 123 common/image.c Ramdisk unit name specified 1815 -124 common/image.c Can't get ramdisk subimage node offset 1816 125 common/image.c Got ramdisk subimage node offset 1817 -125 common/image.c Ramdisk subimage hash verification failed 1818 126 common/image.c Ramdisk subimage hash verification OK 1819 -126 common/image.c Ramdisk subimage for unsupported architecture 1820 127 common/image.c Architecture check OK 1821 -127 common/image.c Can't get ramdisk subimage data/size 1822 128 common/image.c Got ramdisk subimage data/size 1823 129 common/image.c Can't get ramdisk load address 1824 -129 common/image.c Got ramdisk load address 1825 1826 -130 common/cmd_doc.c Icorrect FIT image format 1827 131 common/cmd_doc.c FIT image format OK 1828 1829 -140 common/cmd_ide.c Icorrect FIT image format 1830 141 common/cmd_ide.c FIT image format OK 1831 1832 -150 common/cmd_nand.c Icorrect FIT image format 1833 151 common/cmd_nand.c FIT image format OK 1834 1835 1836Modem Support: 1837-------------- 1838 1839[so far only for SMDK2400 and TRAB boards] 1840 1841- Modem support endable: 1842 CONFIG_MODEM_SUPPORT 1843 1844- RTS/CTS Flow control enable: 1845 CONFIG_HWFLOW 1846 1847- Modem debug support: 1848 CONFIG_MODEM_SUPPORT_DEBUG 1849 1850 Enables debugging stuff (char screen[1024], dbg()) 1851 for modem support. Useful only with BDI2000. 1852 1853- Interrupt support (PPC): 1854 1855 There are common interrupt_init() and timer_interrupt() 1856 for all PPC archs. interrupt_init() calls interrupt_init_cpu() 1857 for cpu specific initialization. interrupt_init_cpu() 1858 should set decrementer_count to appropriate value. If 1859 cpu resets decrementer automatically after interrupt 1860 (ppc4xx) it should set decrementer_count to zero. 1861 timer_interrupt() calls timer_interrupt_cpu() for cpu 1862 specific handling. If board has watchdog / status_led 1863 / other_activity_monitor it works automatically from 1864 general timer_interrupt(). 1865 1866- General: 1867 1868 In the target system modem support is enabled when a 1869 specific key (key combination) is pressed during 1870 power-on. Otherwise U-Boot will boot normally 1871 (autoboot). The key_pressed() fuction is called from 1872 board_init(). Currently key_pressed() is a dummy 1873 function, returning 1 and thus enabling modem 1874 initialization. 1875 1876 If there are no modem init strings in the 1877 environment, U-Boot proceed to autoboot; the 1878 previous output (banner, info printfs) will be 1879 supressed, though. 1880 1881 See also: doc/README.Modem 1882 1883 1884Configuration Settings: 1885----------------------- 1886 1887- CFG_LONGHELP: Defined when you want long help messages included; 1888 undefine this when you're short of memory. 1889 1890- CFG_PROMPT: This is what U-Boot prints on the console to 1891 prompt for user input. 1892 1893- CFG_CBSIZE: Buffer size for input from the Console 1894 1895- CFG_PBSIZE: Buffer size for Console output 1896 1897- CFG_MAXARGS: max. Number of arguments accepted for monitor commands 1898 1899- CFG_BARGSIZE: Buffer size for Boot Arguments which are passed to 1900 the application (usually a Linux kernel) when it is 1901 booted 1902 1903- CFG_BAUDRATE_TABLE: 1904 List of legal baudrate settings for this board. 1905 1906- CFG_CONSOLE_INFO_QUIET 1907 Suppress display of console information at boot. 1908 1909- CFG_CONSOLE_IS_IN_ENV 1910 If the board specific function 1911 extern int overwrite_console (void); 1912 returns 1, the stdin, stderr and stdout are switched to the 1913 serial port, else the settings in the environment are used. 1914 1915- CFG_CONSOLE_OVERWRITE_ROUTINE 1916 Enable the call to overwrite_console(). 1917 1918- CFG_CONSOLE_ENV_OVERWRITE 1919 Enable overwrite of previous console environment settings. 1920 1921- CFG_MEMTEST_START, CFG_MEMTEST_END: 1922 Begin and End addresses of the area used by the 1923 simple memory test. 1924 1925- CFG_ALT_MEMTEST: 1926 Enable an alternate, more extensive memory test. 1927 1928- CFG_MEMTEST_SCRATCH: 1929 Scratch address used by the alternate memory test 1930 You only need to set this if address zero isn't writeable 1931 1932- CFG_TFTP_LOADADDR: 1933 Default load address for network file downloads 1934 1935- CFG_LOADS_BAUD_CHANGE: 1936 Enable temporary baudrate change while serial download 1937 1938- CFG_SDRAM_BASE: 1939 Physical start address of SDRAM. _Must_ be 0 here. 1940 1941- CFG_MBIO_BASE: 1942 Physical start address of Motherboard I/O (if using a 1943 Cogent motherboard) 1944 1945- CFG_FLASH_BASE: 1946 Physical start address of Flash memory. 1947 1948- CFG_MONITOR_BASE: 1949 Physical start address of boot monitor code (set by 1950 make config files to be same as the text base address 1951 (TEXT_BASE) used when linking) - same as 1952 CFG_FLASH_BASE when booting from flash. 1953 1954- CFG_MONITOR_LEN: 1955 Size of memory reserved for monitor code, used to 1956 determine _at_compile_time_ (!) if the environment is 1957 embedded within the U-Boot image, or in a separate 1958 flash sector. 1959 1960- CFG_MALLOC_LEN: 1961 Size of DRAM reserved for malloc() use. 1962 1963- CFG_BOOTM_LEN: 1964 Normally compressed uImages are limited to an 1965 uncompressed size of 8 MBytes. If this is not enough, 1966 you can define CFG_BOOTM_LEN in your board config file 1967 to adjust this setting to your needs. 1968 1969- CFG_BOOTMAPSZ: 1970 Maximum size of memory mapped by the startup code of 1971 the Linux kernel; all data that must be processed by 1972 the Linux kernel (bd_info, boot arguments, eventually 1973 initrd image) must be put below this limit. 1974 1975- CFG_MAX_FLASH_BANKS: 1976 Max number of Flash memory banks 1977 1978- CFG_MAX_FLASH_SECT: 1979 Max number of sectors on a Flash chip 1980 1981- CFG_FLASH_ERASE_TOUT: 1982 Timeout for Flash erase operations (in ms) 1983 1984- CFG_FLASH_WRITE_TOUT: 1985 Timeout for Flash write operations (in ms) 1986 1987- CFG_FLASH_LOCK_TOUT 1988 Timeout for Flash set sector lock bit operation (in ms) 1989 1990- CFG_FLASH_UNLOCK_TOUT 1991 Timeout for Flash clear lock bits operation (in ms) 1992 1993- CFG_FLASH_PROTECTION 1994 If defined, hardware flash sectors protection is used 1995 instead of U-Boot software protection. 1996 1997- CFG_DIRECT_FLASH_TFTP: 1998 1999 Enable TFTP transfers directly to flash memory; 2000 without this option such a download has to be 2001 performed in two steps: (1) download to RAM, and (2) 2002 copy from RAM to flash. 2003 2004 The two-step approach is usually more reliable, since 2005 you can check if the download worked before you erase 2006 the flash, but in some situations (when sytem RAM is 2007 too limited to allow for a tempory copy of the 2008 downloaded image) this option may be very useful. 2009 2010- CFG_FLASH_CFI: 2011 Define if the flash driver uses extra elements in the 2012 common flash structure for storing flash geometry. 2013 2014- CFG_FLASH_CFI_DRIVER 2015 This option also enables the building of the cfi_flash driver 2016 in the drivers directory 2017 2018- CFG_FLASH_QUIET_TEST 2019 If this option is defined, the common CFI flash doesn't 2020 print it's warning upon not recognized FLASH banks. This 2021 is useful, if some of the configured banks are only 2022 optionally available. 2023 2024- CONFIG_FLASH_SHOW_PROGRESS 2025 If defined (must be an integer), print out countdown 2026 digits and dots. Recommended value: 45 (9..1) for 80 2027 column displays, 15 (3..1) for 40 column displays. 2028 2029- CFG_RX_ETH_BUFFER: 2030 Defines the number of ethernet receive buffers. On some 2031 ethernet controllers it is recommended to set this value 2032 to 8 or even higher (EEPRO100 or 405 EMAC), since all 2033 buffers can be full shortly after enabling the interface 2034 on high ethernet traffic. 2035 Defaults to 4 if not defined. 2036 2037The following definitions that deal with the placement and management 2038of environment data (variable area); in general, we support the 2039following configurations: 2040 2041- CFG_ENV_IS_IN_FLASH: 2042 2043 Define this if the environment is in flash memory. 2044 2045 a) The environment occupies one whole flash sector, which is 2046 "embedded" in the text segment with the U-Boot code. This 2047 happens usually with "bottom boot sector" or "top boot 2048 sector" type flash chips, which have several smaller 2049 sectors at the start or the end. For instance, such a 2050 layout can have sector sizes of 8, 2x4, 16, Nx32 kB. In 2051 such a case you would place the environment in one of the 2052 4 kB sectors - with U-Boot code before and after it. With 2053 "top boot sector" type flash chips, you would put the 2054 environment in one of the last sectors, leaving a gap 2055 between U-Boot and the environment. 2056 2057 - CFG_ENV_OFFSET: 2058 2059 Offset of environment data (variable area) to the 2060 beginning of flash memory; for instance, with bottom boot 2061 type flash chips the second sector can be used: the offset 2062 for this sector is given here. 2063 2064 CFG_ENV_OFFSET is used relative to CFG_FLASH_BASE. 2065 2066 - CFG_ENV_ADDR: 2067 2068 This is just another way to specify the start address of 2069 the flash sector containing the environment (instead of 2070 CFG_ENV_OFFSET). 2071 2072 - CFG_ENV_SECT_SIZE: 2073 2074 Size of the sector containing the environment. 2075 2076 2077 b) Sometimes flash chips have few, equal sized, BIG sectors. 2078 In such a case you don't want to spend a whole sector for 2079 the environment. 2080 2081 - CFG_ENV_SIZE: 2082 2083 If you use this in combination with CFG_ENV_IS_IN_FLASH 2084 and CFG_ENV_SECT_SIZE, you can specify to use only a part 2085 of this flash sector for the environment. This saves 2086 memory for the RAM copy of the environment. 2087 2088 It may also save flash memory if you decide to use this 2089 when your environment is "embedded" within U-Boot code, 2090 since then the remainder of the flash sector could be used 2091 for U-Boot code. It should be pointed out that this is 2092 STRONGLY DISCOURAGED from a robustness point of view: 2093 updating the environment in flash makes it always 2094 necessary to erase the WHOLE sector. If something goes 2095 wrong before the contents has been restored from a copy in 2096 RAM, your target system will be dead. 2097 2098 - CFG_ENV_ADDR_REDUND 2099 CFG_ENV_SIZE_REDUND 2100 2101 These settings describe a second storage area used to hold 2102 a redundand copy of the environment data, so that there is 2103 a valid backup copy in case there is a power failure during 2104 a "saveenv" operation. 2105 2106BE CAREFUL! Any changes to the flash layout, and some changes to the 2107source code will make it necessary to adapt <board>/u-boot.lds* 2108accordingly! 2109 2110 2111- CFG_ENV_IS_IN_NVRAM: 2112 2113 Define this if you have some non-volatile memory device 2114 (NVRAM, battery buffered SRAM) which you want to use for the 2115 environment. 2116 2117 - CFG_ENV_ADDR: 2118 - CFG_ENV_SIZE: 2119 2120 These two #defines are used to determin the memory area you 2121 want to use for environment. It is assumed that this memory 2122 can just be read and written to, without any special 2123 provision. 2124 2125BE CAREFUL! The first access to the environment happens quite early 2126in U-Boot initalization (when we try to get the setting of for the 2127console baudrate). You *MUST* have mappend your NVRAM area then, or 2128U-Boot will hang. 2129 2130Please note that even with NVRAM we still use a copy of the 2131environment in RAM: we could work on NVRAM directly, but we want to 2132keep settings there always unmodified except somebody uses "saveenv" 2133to save the current settings. 2134 2135 2136- CFG_ENV_IS_IN_EEPROM: 2137 2138 Use this if you have an EEPROM or similar serial access 2139 device and a driver for it. 2140 2141 - CFG_ENV_OFFSET: 2142 - CFG_ENV_SIZE: 2143 2144 These two #defines specify the offset and size of the 2145 environment area within the total memory of your EEPROM. 2146 2147 - CFG_I2C_EEPROM_ADDR: 2148 If defined, specified the chip address of the EEPROM device. 2149 The default address is zero. 2150 2151 - CFG_EEPROM_PAGE_WRITE_BITS: 2152 If defined, the number of bits used to address bytes in a 2153 single page in the EEPROM device. A 64 byte page, for example 2154 would require six bits. 2155 2156 - CFG_EEPROM_PAGE_WRITE_DELAY_MS: 2157 If defined, the number of milliseconds to delay between 2158 page writes. The default is zero milliseconds. 2159 2160 - CFG_I2C_EEPROM_ADDR_LEN: 2161 The length in bytes of the EEPROM memory array address. Note 2162 that this is NOT the chip address length! 2163 2164 - CFG_I2C_EEPROM_ADDR_OVERFLOW: 2165 EEPROM chips that implement "address overflow" are ones 2166 like Catalyst 24WC04/08/16 which has 9/10/11 bits of 2167 address and the extra bits end up in the "chip address" bit 2168 slots. This makes a 24WC08 (1Kbyte) chip look like four 256 2169 byte chips. 2170 2171 Note that we consider the length of the address field to 2172 still be one byte because the extra address bits are hidden 2173 in the chip address. 2174 2175 - CFG_EEPROM_SIZE: 2176 The size in bytes of the EEPROM device. 2177 2178 2179- CFG_ENV_IS_IN_DATAFLASH: 2180 2181 Define this if you have a DataFlash memory device which you 2182 want to use for the environment. 2183 2184 - CFG_ENV_OFFSET: 2185 - CFG_ENV_ADDR: 2186 - CFG_ENV_SIZE: 2187 2188 These three #defines specify the offset and size of the 2189 environment area within the total memory of your DataFlash placed 2190 at the specified address. 2191 2192- CFG_ENV_IS_IN_NAND: 2193 2194 Define this if you have a NAND device which you want to use 2195 for the environment. 2196 2197 - CFG_ENV_OFFSET: 2198 - CFG_ENV_SIZE: 2199 2200 These two #defines specify the offset and size of the environment 2201 area within the first NAND device. 2202 2203 - CFG_ENV_OFFSET_REDUND 2204 2205 This setting describes a second storage area of CFG_ENV_SIZE 2206 size used to hold a redundant copy of the environment data, 2207 so that there is a valid backup copy in case there is a 2208 power failure during a "saveenv" operation. 2209 2210 Note: CFG_ENV_OFFSET and CFG_ENV_OFFSET_REDUND must be aligned 2211 to a block boundary, and CFG_ENV_SIZE must be a multiple of 2212 the NAND devices block size. 2213 2214- CFG_SPI_INIT_OFFSET 2215 2216 Defines offset to the initial SPI buffer area in DPRAM. The 2217 area is used at an early stage (ROM part) if the environment 2218 is configured to reside in the SPI EEPROM: We need a 520 byte 2219 scratch DPRAM area. It is used between the two initialization 2220 calls (spi_init_f() and spi_init_r()). A value of 0xB00 seems 2221 to be a good choice since it makes it far enough from the 2222 start of the data area as well as from the stack pointer. 2223 2224Please note that the environment is read-only until the monitor 2225has been relocated to RAM and a RAM copy of the environment has been 2226created; also, when using EEPROM you will have to use getenv_r() 2227until then to read environment variables. 2228 2229The environment is protected by a CRC32 checksum. Before the monitor 2230is relocated into RAM, as a result of a bad CRC you will be working 2231with the compiled-in default environment - *silently*!!! [This is 2232necessary, because the first environment variable we need is the 2233"baudrate" setting for the console - if we have a bad CRC, we don't 2234have any device yet where we could complain.] 2235 2236Note: once the monitor has been relocated, then it will complain if 2237the default environment is used; a new CRC is computed as soon as you 2238use the "saveenv" command to store a valid environment. 2239 2240- CFG_FAULT_ECHO_LINK_DOWN: 2241 Echo the inverted Ethernet link state to the fault LED. 2242 2243 Note: If this option is active, then CFG_FAULT_MII_ADDR 2244 also needs to be defined. 2245 2246- CFG_FAULT_MII_ADDR: 2247 MII address of the PHY to check for the Ethernet link state. 2248 2249- CFG_64BIT_VSPRINTF: 2250 Makes vsprintf (and all *printf functions) support printing 2251 of 64bit values by using the L quantifier 2252 2253- CFG_64BIT_STRTOUL: 2254 Adds simple_strtoull that returns a 64bit value 2255 2256Low Level (hardware related) configuration options: 2257--------------------------------------------------- 2258 2259- CFG_CACHELINE_SIZE: 2260 Cache Line Size of the CPU. 2261 2262- CFG_DEFAULT_IMMR: 2263 Default address of the IMMR after system reset. 2264 2265 Needed on some 8260 systems (MPC8260ADS, PQ2FADS-ZU, 2266 and RPXsuper) to be able to adjust the position of 2267 the IMMR register after a reset. 2268 2269- Floppy Disk Support: 2270 CFG_FDC_DRIVE_NUMBER 2271 2272 the default drive number (default value 0) 2273 2274 CFG_ISA_IO_STRIDE 2275 2276 defines the spacing between fdc chipset registers 2277 (default value 1) 2278 2279 CFG_ISA_IO_OFFSET 2280 2281 defines the offset of register from address. It 2282 depends on which part of the data bus is connected to 2283 the fdc chipset. (default value 0) 2284 2285 If CFG_ISA_IO_STRIDE CFG_ISA_IO_OFFSET and 2286 CFG_FDC_DRIVE_NUMBER are undefined, they take their 2287 default value. 2288 2289 if CFG_FDC_HW_INIT is defined, then the function 2290 fdc_hw_init() is called at the beginning of the FDC 2291 setup. fdc_hw_init() must be provided by the board 2292 source code. It is used to make hardware dependant 2293 initializations. 2294 2295- CFG_IMMR: Physical address of the Internal Memory. 2296 DO NOT CHANGE unless you know exactly what you're 2297 doing! (11-4) [MPC8xx/82xx systems only] 2298 2299- CFG_INIT_RAM_ADDR: 2300 2301 Start address of memory area that can be used for 2302 initial data and stack; please note that this must be 2303 writable memory that is working WITHOUT special 2304 initialization, i. e. you CANNOT use normal RAM which 2305 will become available only after programming the 2306 memory controller and running certain initialization 2307 sequences. 2308 2309 U-Boot uses the following memory types: 2310 - MPC8xx and MPC8260: IMMR (internal memory of the CPU) 2311 - MPC824X: data cache 2312 - PPC4xx: data cache 2313 2314- CFG_GBL_DATA_OFFSET: 2315 2316 Offset of the initial data structure in the memory 2317 area defined by CFG_INIT_RAM_ADDR. Usually 2318 CFG_GBL_DATA_OFFSET is chosen such that the initial 2319 data is located at the end of the available space 2320 (sometimes written as (CFG_INIT_RAM_END - 2321 CFG_INIT_DATA_SIZE), and the initial stack is just 2322 below that area (growing from (CFG_INIT_RAM_ADDR + 2323 CFG_GBL_DATA_OFFSET) downward. 2324 2325 Note: 2326 On the MPC824X (or other systems that use the data 2327 cache for initial memory) the address chosen for 2328 CFG_INIT_RAM_ADDR is basically arbitrary - it must 2329 point to an otherwise UNUSED address space between 2330 the top of RAM and the start of the PCI space. 2331 2332- CFG_SIUMCR: SIU Module Configuration (11-6) 2333 2334- CFG_SYPCR: System Protection Control (11-9) 2335 2336- CFG_TBSCR: Time Base Status and Control (11-26) 2337 2338- CFG_PISCR: Periodic Interrupt Status and Control (11-31) 2339 2340- CFG_PLPRCR: PLL, Low-Power, and Reset Control Register (15-30) 2341 2342- CFG_SCCR: System Clock and reset Control Register (15-27) 2343 2344- CFG_OR_TIMING_SDRAM: 2345 SDRAM timing 2346 2347- CFG_MAMR_PTA: 2348 periodic timer for refresh 2349 2350- CFG_DER: Debug Event Register (37-47) 2351 2352- FLASH_BASE0_PRELIM, FLASH_BASE1_PRELIM, CFG_REMAP_OR_AM, 2353 CFG_PRELIM_OR_AM, CFG_OR_TIMING_FLASH, CFG_OR0_REMAP, 2354 CFG_OR0_PRELIM, CFG_BR0_PRELIM, CFG_OR1_REMAP, CFG_OR1_PRELIM, 2355 CFG_BR1_PRELIM: 2356 Memory Controller Definitions: BR0/1 and OR0/1 (FLASH) 2357 2358- SDRAM_BASE2_PRELIM, SDRAM_BASE3_PRELIM, SDRAM_MAX_SIZE, 2359 CFG_OR_TIMING_SDRAM, CFG_OR2_PRELIM, CFG_BR2_PRELIM, 2360 CFG_OR3_PRELIM, CFG_BR3_PRELIM: 2361 Memory Controller Definitions: BR2/3 and OR2/3 (SDRAM) 2362 2363- CFG_MAMR_PTA, CFG_MPTPR_2BK_4K, CFG_MPTPR_1BK_4K, CFG_MPTPR_2BK_8K, 2364 CFG_MPTPR_1BK_8K, CFG_MAMR_8COL, CFG_MAMR_9COL: 2365 Machine Mode Register and Memory Periodic Timer 2366 Prescaler definitions (SDRAM timing) 2367 2368- CFG_I2C_UCODE_PATCH, CFG_I2C_DPMEM_OFFSET [0x1FC0]: 2369 enable I2C microcode relocation patch (MPC8xx); 2370 define relocation offset in DPRAM [DSP2] 2371 2372- CFG_SMC_UCODE_PATCH, CFG_SMC_DPMEM_OFFSET [0x1FC0]: 2373 enable SMC microcode relocation patch (MPC8xx); 2374 define relocation offset in DPRAM [SMC1] 2375 2376- CFG_SPI_UCODE_PATCH, CFG_SPI_DPMEM_OFFSET [0x1FC0]: 2377 enable SPI microcode relocation patch (MPC8xx); 2378 define relocation offset in DPRAM [SCC4] 2379 2380- CFG_USE_OSCCLK: 2381 Use OSCM clock mode on MBX8xx board. Be careful, 2382 wrong setting might damage your board. Read 2383 doc/README.MBX before setting this variable! 2384 2385- CFG_CPM_POST_WORD_ADDR: (MPC8xx, MPC8260 only) 2386 Offset of the bootmode word in DPRAM used by post 2387 (Power On Self Tests). This definition overrides 2388 #define'd default value in commproc.h resp. 2389 cpm_8260.h. 2390 2391- CFG_PCI_SLV_MEM_LOCAL, CFG_PCI_SLV_MEM_BUS, CFG_PICMR0_MASK_ATTRIB, 2392 CFG_PCI_MSTR0_LOCAL, CFG_PCIMSK0_MASK, CFG_PCI_MSTR1_LOCAL, 2393 CFG_PCIMSK1_MASK, CFG_PCI_MSTR_MEM_LOCAL, CFG_PCI_MSTR_MEM_BUS, 2394 CFG_CPU_PCI_MEM_START, CFG_PCI_MSTR_MEM_SIZE, CFG_POCMR0_MASK_ATTRIB, 2395 CFG_PCI_MSTR_MEMIO_LOCAL, CFG_PCI_MSTR_MEMIO_BUS, CPU_PCI_MEMIO_START, 2396 CFG_PCI_MSTR_MEMIO_SIZE, CFG_POCMR1_MASK_ATTRIB, CFG_PCI_MSTR_IO_LOCAL, 2397 CFG_PCI_MSTR_IO_BUS, CFG_CPU_PCI_IO_START, CFG_PCI_MSTR_IO_SIZE, 2398 CFG_POCMR2_MASK_ATTRIB: (MPC826x only) 2399 Overrides the default PCI memory map in cpu/mpc8260/pci.c if set. 2400 2401- CONFIG_SPD_EEPROM 2402 Get DDR timing information from an I2C EEPROM. Common 2403 with pluggable memory modules such as SODIMMs 2404 2405 SPD_EEPROM_ADDRESS 2406 I2C address of the SPD EEPROM 2407 2408- CFG_SPD_BUS_NUM 2409 If SPD EEPROM is on an I2C bus other than the first 2410 one, specify here. Note that the value must resolve 2411 to something your driver can deal with. 2412 2413- CFG_83XX_DDR_USES_CS0 2414 Only for 83xx systems. If specified, then DDR should 2415 be configured using CS0 and CS1 instead of CS2 and CS3. 2416 2417- CFG_83XX_DDR_USES_CS0 2418 Only for 83xx systems. If specified, then DDR should 2419 be configured using CS0 and CS1 instead of CS2 and CS3. 2420 2421- CONFIG_ETHER_ON_FEC[12] 2422 Define to enable FEC[12] on a 8xx series processor. 2423 2424- CONFIG_FEC[12]_PHY 2425 Define to the hardcoded PHY address which corresponds 2426 to the given FEC; i. e. 2427 #define CONFIG_FEC1_PHY 4 2428 means that the PHY with address 4 is connected to FEC1 2429 2430 When set to -1, means to probe for first available. 2431 2432- CONFIG_FEC[12]_PHY_NORXERR 2433 The PHY does not have a RXERR line (RMII only). 2434 (so program the FEC to ignore it). 2435 2436- CONFIG_RMII 2437 Enable RMII mode for all FECs. 2438 Note that this is a global option, we can't 2439 have one FEC in standard MII mode and another in RMII mode. 2440 2441- CONFIG_CRC32_VERIFY 2442 Add a verify option to the crc32 command. 2443 The syntax is: 2444 2445 => crc32 -v <address> <count> <crc32> 2446 2447 Where address/count indicate a memory area 2448 and crc32 is the correct crc32 which the 2449 area should have. 2450 2451- CONFIG_LOOPW 2452 Add the "loopw" memory command. This only takes effect if 2453 the memory commands are activated globally (CONFIG_CMD_MEM). 2454 2455- CONFIG_MX_CYCLIC 2456 Add the "mdc" and "mwc" memory commands. These are cyclic 2457 "md/mw" commands. 2458 Examples: 2459 2460 => mdc.b 10 4 500 2461 This command will print 4 bytes (10,11,12,13) each 500 ms. 2462 2463 => mwc.l 100 12345678 10 2464 This command will write 12345678 to address 100 all 10 ms. 2465 2466 This only takes effect if the memory commands are activated 2467 globally (CONFIG_CMD_MEM). 2468 2469- CONFIG_SKIP_LOWLEVEL_INIT 2470- CONFIG_SKIP_RELOCATE_UBOOT 2471 2472 [ARM only] If these variables are defined, then 2473 certain low level initializations (like setting up 2474 the memory controller) are omitted and/or U-Boot does 2475 not relocate itself into RAM. 2476 Normally these variables MUST NOT be defined. The 2477 only exception is when U-Boot is loaded (to RAM) by 2478 some other boot loader or by a debugger which 2479 performs these intializations itself. 2480 2481 2482Building the Software: 2483====================== 2484 2485Building U-Boot has been tested in several native build environments 2486and in many different cross environments. Of course we cannot support 2487all possibly existing versions of cross development tools in all 2488(potentially obsolete) versions. In case of tool chain problems we 2489recommend to use the ELDK (see http://www.denx.de/wiki/DULG/ELDK) 2490which is extensively used to build and test U-Boot. 2491 2492If you are not using a native environment, it is assumed that you 2493have GNU cross compiling tools available in your path. In this case, 2494you must set the environment variable CROSS_COMPILE in your shell. 2495Note that no changes to the Makefile or any other source files are 2496necessary. For example using the ELDK on a 4xx CPU, please enter: 2497 2498 $ CROSS_COMPILE=ppc_4xx- 2499 $ export CROSS_COMPILE 2500 2501U-Boot is intended to be simple to build. After installing the 2502sources you must configure U-Boot for one specific board type. This 2503is done by typing: 2504 2505 make NAME_config 2506 2507where "NAME_config" is the name of one of the existing configu- 2508rations; see the main Makefile for supported names. 2509 2510Note: for some board special configuration names may exist; check if 2511 additional information is available from the board vendor; for 2512 instance, the TQM823L systems are available without (standard) 2513 or with LCD support. You can select such additional "features" 2514 when chosing the configuration, i. e. 2515 2516 make TQM823L_config 2517 - will configure for a plain TQM823L, i. e. no LCD support 2518 2519 make TQM823L_LCD_config 2520 - will configure for a TQM823L with U-Boot console on LCD 2521 2522 etc. 2523 2524 2525Finally, type "make all", and you should get some working U-Boot 2526images ready for download to / installation on your system: 2527 2528- "u-boot.bin" is a raw binary image 2529- "u-boot" is an image in ELF binary format 2530- "u-boot.srec" is in Motorola S-Record format 2531 2532By default the build is performed locally and the objects are saved 2533in the source directory. One of the two methods can be used to change 2534this behavior and build U-Boot to some external directory: 2535 25361. Add O= to the make command line invocations: 2537 2538 make O=/tmp/build distclean 2539 make O=/tmp/build NAME_config 2540 make O=/tmp/build all 2541 25422. Set environment variable BUILD_DIR to point to the desired location: 2543 2544 export BUILD_DIR=/tmp/build 2545 make distclean 2546 make NAME_config 2547 make all 2548 2549Note that the command line "O=" setting overrides the BUILD_DIR environment 2550variable. 2551 2552 2553Please be aware that the Makefiles assume you are using GNU make, so 2554for instance on NetBSD you might need to use "gmake" instead of 2555native "make". 2556 2557 2558If the system board that you have is not listed, then you will need 2559to port U-Boot to your hardware platform. To do this, follow these 2560steps: 2561 25621. Add a new configuration option for your board to the toplevel 2563 "Makefile" and to the "MAKEALL" script, using the existing 2564 entries as examples. Note that here and at many other places 2565 boards and other names are listed in alphabetical sort order. Please 2566 keep this order. 25672. Create a new directory to hold your board specific code. Add any 2568 files you need. In your board directory, you will need at least 2569 the "Makefile", a "<board>.c", "flash.c" and "u-boot.lds". 25703. Create a new configuration file "include/configs/<board>.h" for 2571 your board 25723. If you're porting U-Boot to a new CPU, then also create a new 2573 directory to hold your CPU specific code. Add any files you need. 25744. Run "make <board>_config" with your new name. 25755. Type "make", and you should get a working "u-boot.srec" file 2576 to be installed on your target system. 25776. Debug and solve any problems that might arise. 2578 [Of course, this last step is much harder than it sounds.] 2579 2580 2581Testing of U-Boot Modifications, Ports to New Hardware, etc.: 2582============================================================== 2583 2584If you have modified U-Boot sources (for instance added a new board 2585or support for new devices, a new CPU, etc.) you are expected to 2586provide feedback to the other developers. The feedback normally takes 2587the form of a "patch", i. e. a context diff against a certain (latest 2588official or latest in the git repository) version of U-Boot sources. 2589 2590But before you submit such a patch, please verify that your modifi- 2591cation did not break existing code. At least make sure that *ALL* of 2592the supported boards compile WITHOUT ANY compiler warnings. To do so, 2593just run the "MAKEALL" script, which will configure and build U-Boot 2594for ALL supported system. Be warned, this will take a while. You can 2595select which (cross) compiler to use by passing a `CROSS_COMPILE' 2596environment variable to the script, i. e. to use the ELDK cross tools 2597you can type 2598 2599 CROSS_COMPILE=ppc_8xx- MAKEALL 2600 2601or to build on a native PowerPC system you can type 2602 2603 CROSS_COMPILE=' ' MAKEALL 2604 2605When using the MAKEALL script, the default behaviour is to build 2606U-Boot in the source directory. This location can be changed by 2607setting the BUILD_DIR environment variable. Also, for each target 2608built, the MAKEALL script saves two log files (<target>.ERR and 2609<target>.MAKEALL) in the <source dir>/LOG directory. This default 2610location can be changed by setting the MAKEALL_LOGDIR environment 2611variable. For example: 2612 2613 export BUILD_DIR=/tmp/build 2614 export MAKEALL_LOGDIR=/tmp/log 2615 CROSS_COMPILE=ppc_8xx- MAKEALL 2616 2617With the above settings build objects are saved in the /tmp/build, 2618log files are saved in the /tmp/log and the source tree remains clean 2619during the whole build process. 2620 2621 2622See also "U-Boot Porting Guide" below. 2623 2624 2625Monitor Commands - Overview: 2626============================ 2627 2628go - start application at address 'addr' 2629run - run commands in an environment variable 2630bootm - boot application image from memory 2631bootp - boot image via network using BootP/TFTP protocol 2632tftpboot- boot image via network using TFTP protocol 2633 and env variables "ipaddr" and "serverip" 2634 (and eventually "gatewayip") 2635rarpboot- boot image via network using RARP/TFTP protocol 2636diskboot- boot from IDE devicebootd - boot default, i.e., run 'bootcmd' 2637loads - load S-Record file over serial line 2638loadb - load binary file over serial line (kermit mode) 2639md - memory display 2640mm - memory modify (auto-incrementing) 2641nm - memory modify (constant address) 2642mw - memory write (fill) 2643cp - memory copy 2644cmp - memory compare 2645crc32 - checksum calculation 2646imd - i2c memory display 2647imm - i2c memory modify (auto-incrementing) 2648inm - i2c memory modify (constant address) 2649imw - i2c memory write (fill) 2650icrc32 - i2c checksum calculation 2651iprobe - probe to discover valid I2C chip addresses 2652iloop - infinite loop on address range 2653isdram - print SDRAM configuration information 2654sspi - SPI utility commands 2655base - print or set address offset 2656printenv- print environment variables 2657setenv - set environment variables 2658saveenv - save environment variables to persistent storage 2659protect - enable or disable FLASH write protection 2660erase - erase FLASH memory 2661flinfo - print FLASH memory information 2662bdinfo - print Board Info structure 2663iminfo - print header information for application image 2664coninfo - print console devices and informations 2665ide - IDE sub-system 2666loop - infinite loop on address range 2667loopw - infinite write loop on address range 2668mtest - simple RAM test 2669icache - enable or disable instruction cache 2670dcache - enable or disable data cache 2671reset - Perform RESET of the CPU 2672echo - echo args to console 2673version - print monitor version 2674help - print online help 2675? - alias for 'help' 2676 2677 2678Monitor Commands - Detailed Description: 2679======================================== 2680 2681TODO. 2682 2683For now: just type "help <command>". 2684 2685 2686Environment Variables: 2687====================== 2688 2689U-Boot supports user configuration using Environment Variables which 2690can be made persistent by saving to Flash memory. 2691 2692Environment Variables are set using "setenv", printed using 2693"printenv", and saved to Flash using "saveenv". Using "setenv" 2694without a value can be used to delete a variable from the 2695environment. As long as you don't save the environment you are 2696working with an in-memory copy. In case the Flash area containing the 2697environment is erased by accident, a default environment is provided. 2698 2699Some configuration options can be set using Environment Variables: 2700 2701 baudrate - see CONFIG_BAUDRATE 2702 2703 bootdelay - see CONFIG_BOOTDELAY 2704 2705 bootcmd - see CONFIG_BOOTCOMMAND 2706 2707 bootargs - Boot arguments when booting an RTOS image 2708 2709 bootfile - Name of the image to load with TFTP 2710 2711 autoload - if set to "no" (any string beginning with 'n'), 2712 "bootp" will just load perform a lookup of the 2713 configuration from the BOOTP server, but not try to 2714 load any image using TFTP 2715 2716 autoscript - if set to "yes" commands like "loadb", "loady", 2717 "bootp", "tftpb", "rarpboot" and "nfs" will attempt 2718 to automatically run script images (by internally 2719 calling "autoscript"). 2720 2721 autoscript_uname - if script image is in a format (FIT) this 2722 variable is used to get script subimage unit name. 2723 2724 autostart - if set to "yes", an image loaded using the "bootp", 2725 "rarpboot", "tftpboot" or "diskboot" commands will 2726 be automatically started (by internally calling 2727 "bootm") 2728 2729 If set to "no", a standalone image passed to the 2730 "bootm" command will be copied to the load address 2731 (and eventually uncompressed), but NOT be started. 2732 This can be used to load and uncompress arbitrary 2733 data. 2734 2735 i2cfast - (PPC405GP|PPC405EP only) 2736 if set to 'y' configures Linux I2C driver for fast 2737 mode (400kHZ). This environment variable is used in 2738 initialization code. So, for changes to be effective 2739 it must be saved and board must be reset. 2740 2741 initrd_high - restrict positioning of initrd images: 2742 If this variable is not set, initrd images will be 2743 copied to the highest possible address in RAM; this 2744 is usually what you want since it allows for 2745 maximum initrd size. If for some reason you want to 2746 make sure that the initrd image is loaded below the 2747 CFG_BOOTMAPSZ limit, you can set this environment 2748 variable to a value of "no" or "off" or "0". 2749 Alternatively, you can set it to a maximum upper 2750 address to use (U-Boot will still check that it 2751 does not overwrite the U-Boot stack and data). 2752 2753 For instance, when you have a system with 16 MB 2754 RAM, and want to reserve 4 MB from use by Linux, 2755 you can do this by adding "mem=12M" to the value of 2756 the "bootargs" variable. However, now you must make 2757 sure that the initrd image is placed in the first 2758 12 MB as well - this can be done with 2759 2760 setenv initrd_high 00c00000 2761 2762 If you set initrd_high to 0xFFFFFFFF, this is an 2763 indication to U-Boot that all addresses are legal 2764 for the Linux kernel, including addresses in flash 2765 memory. In this case U-Boot will NOT COPY the 2766 ramdisk at all. This may be useful to reduce the 2767 boot time on your system, but requires that this 2768 feature is supported by your Linux kernel. 2769 2770 ipaddr - IP address; needed for tftpboot command 2771 2772 loadaddr - Default load address for commands like "bootp", 2773 "rarpboot", "tftpboot", "loadb" or "diskboot" 2774 2775 loads_echo - see CONFIG_LOADS_ECHO 2776 2777 serverip - TFTP server IP address; needed for tftpboot command 2778 2779 bootretry - see CONFIG_BOOT_RETRY_TIME 2780 2781 bootdelaykey - see CONFIG_AUTOBOOT_DELAY_STR 2782 2783 bootstopkey - see CONFIG_AUTOBOOT_STOP_STR 2784 2785 ethprime - When CONFIG_NET_MULTI is enabled controls which 2786 interface is used first. 2787 2788 ethact - When CONFIG_NET_MULTI is enabled controls which 2789 interface is currently active. For example you 2790 can do the following 2791 2792 => setenv ethact FEC ETHERNET 2793 => ping 192.168.0.1 # traffic sent on FEC ETHERNET 2794 => setenv ethact SCC ETHERNET 2795 => ping 10.0.0.1 # traffic sent on SCC ETHERNET 2796 2797 ethrotate - When set to "no" U-Boot does not go through all 2798 available network interfaces. 2799 It just stays at the currently selected interface. 2800 2801 netretry - When set to "no" each network operation will 2802 either succeed or fail without retrying. 2803 When set to "once" the network operation will 2804 fail when all the available network interfaces 2805 are tried once without success. 2806 Useful on scripts which control the retry operation 2807 themselves. 2808 2809 npe_ucode - see CONFIG_IXP4XX_NPE_EXT_UCOD 2810 if set load address for the npe microcode 2811 2812 tftpsrcport - If this is set, the value is used for TFTP's 2813 UDP source port. 2814 2815 tftpdstport - If this is set, the value is used for TFTP's UDP 2816 destination port instead of the Well Know Port 69. 2817 2818 vlan - When set to a value < 4095 the traffic over 2819 ethernet is encapsulated/received over 802.1q 2820 VLAN tagged frames. 2821 2822The following environment variables may be used and automatically 2823updated by the network boot commands ("bootp" and "rarpboot"), 2824depending the information provided by your boot server: 2825 2826 bootfile - see above 2827 dnsip - IP address of your Domain Name Server 2828 dnsip2 - IP address of your secondary Domain Name Server 2829 gatewayip - IP address of the Gateway (Router) to use 2830 hostname - Target hostname 2831 ipaddr - see above 2832 netmask - Subnet Mask 2833 rootpath - Pathname of the root filesystem on the NFS server 2834 serverip - see above 2835 2836 2837There are two special Environment Variables: 2838 2839 serial# - contains hardware identification information such 2840 as type string and/or serial number 2841 ethaddr - Ethernet address 2842 2843These variables can be set only once (usually during manufacturing of 2844the board). U-Boot refuses to delete or overwrite these variables 2845once they have been set once. 2846 2847 2848Further special Environment Variables: 2849 2850 ver - Contains the U-Boot version string as printed 2851 with the "version" command. This variable is 2852 readonly (see CONFIG_VERSION_VARIABLE). 2853 2854 2855Please note that changes to some configuration parameters may take 2856only effect after the next boot (yes, that's just like Windoze :-). 2857 2858 2859Command Line Parsing: 2860===================== 2861 2862There are two different command line parsers available with U-Boot: 2863the old "simple" one, and the much more powerful "hush" shell: 2864 2865Old, simple command line parser: 2866-------------------------------- 2867 2868- supports environment variables (through setenv / saveenv commands) 2869- several commands on one line, separated by ';' 2870- variable substitution using "... ${name} ..." syntax 2871- special characters ('$', ';') can be escaped by prefixing with '\', 2872 for example: 2873 setenv bootcmd bootm \${address} 2874- You can also escape text by enclosing in single apostrophes, for example: 2875 setenv addip 'setenv bootargs $bootargs ip=$ipaddr:$serverip:$gatewayip:$netmask:$hostname::off' 2876 2877Hush shell: 2878----------- 2879 2880- similar to Bourne shell, with control structures like 2881 if...then...else...fi, for...do...done; while...do...done, 2882 until...do...done, ... 2883- supports environment ("global") variables (through setenv / saveenv 2884 commands) and local shell variables (through standard shell syntax 2885 "name=value"); only environment variables can be used with "run" 2886 command 2887 2888General rules: 2889-------------- 2890 2891(1) If a command line (or an environment variable executed by a "run" 2892 command) contains several commands separated by semicolon, and 2893 one of these commands fails, then the remaining commands will be 2894 executed anyway. 2895 2896(2) If you execute several variables with one call to run (i. e. 2897 calling run with a list af variables as arguments), any failing 2898 command will cause "run" to terminate, i. e. the remaining 2899 variables are not executed. 2900 2901Note for Redundant Ethernet Interfaces: 2902======================================= 2903 2904Some boards come with redundant ethernet interfaces; U-Boot supports 2905such configurations and is capable of automatic selection of a 2906"working" interface when needed. MAC assignment works as follows: 2907 2908Network interfaces are numbered eth0, eth1, eth2, ... Corresponding 2909MAC addresses can be stored in the environment as "ethaddr" (=>eth0), 2910"eth1addr" (=>eth1), "eth2addr", ... 2911 2912If the network interface stores some valid MAC address (for instance 2913in SROM), this is used as default address if there is NO correspon- 2914ding setting in the environment; if the corresponding environment 2915variable is set, this overrides the settings in the card; that means: 2916 2917o If the SROM has a valid MAC address, and there is no address in the 2918 environment, the SROM's address is used. 2919 2920o If there is no valid address in the SROM, and a definition in the 2921 environment exists, then the value from the environment variable is 2922 used. 2923 2924o If both the SROM and the environment contain a MAC address, and 2925 both addresses are the same, this MAC address is used. 2926 2927o If both the SROM and the environment contain a MAC address, and the 2928 addresses differ, the value from the environment is used and a 2929 warning is printed. 2930 2931o If neither SROM nor the environment contain a MAC address, an error 2932 is raised. 2933 2934 2935Image Formats: 2936============== 2937 2938U-Boot is capable of booting (and performing other auxiliary operations on) 2939images in two formats: 2940 2941New uImage format (FIT) 2942----------------------- 2943 2944Flexible and powerful format based on Flattened Image Tree -- FIT (similar 2945to Flattened Device Tree). It allows the use of images with multiple 2946components (several kernels, ramdisks, etc.), with contents protected by 2947SHA1, MD5 or CRC32. More details are found in the doc/uImage.FIT directory. 2948 2949 2950Old uImage format 2951----------------- 2952 2953Old image format is based on binary files which can be basically anything, 2954preceded by a special header; see the definitions in include/image.h for 2955details; basically, the header defines the following image properties: 2956 2957* Target Operating System (Provisions for OpenBSD, NetBSD, FreeBSD, 2958 4.4BSD, Linux, SVR4, Esix, Solaris, Irix, SCO, Dell, NCR, VxWorks, 2959 LynxOS, pSOS, QNX, RTEMS, ARTOS; 2960 Currently supported: Linux, NetBSD, VxWorks, QNX, RTEMS, ARTOS, LynxOS). 2961* Target CPU Architecture (Provisions for Alpha, ARM, AVR32, Intel x86, 2962 IA64, MIPS, NIOS, PowerPC, IBM S390, SuperH, Sparc, Sparc 64 Bit; 2963 Currently supported: ARM, AVR32, Intel x86, MIPS, NIOS, PowerPC). 2964* Compression Type (uncompressed, gzip, bzip2) 2965* Load Address 2966* Entry Point 2967* Image Name 2968* Image Timestamp 2969 2970The header is marked by a special Magic Number, and both the header 2971and the data portions of the image are secured against corruption by 2972CRC32 checksums. 2973 2974 2975Linux Support: 2976============== 2977 2978Although U-Boot should support any OS or standalone application 2979easily, the main focus has always been on Linux during the design of 2980U-Boot. 2981 2982U-Boot includes many features that so far have been part of some 2983special "boot loader" code within the Linux kernel. Also, any 2984"initrd" images to be used are no longer part of one big Linux image; 2985instead, kernel and "initrd" are separate images. This implementation 2986serves several purposes: 2987 2988- the same features can be used for other OS or standalone 2989 applications (for instance: using compressed images to reduce the 2990 Flash memory footprint) 2991 2992- it becomes much easier to port new Linux kernel versions because 2993 lots of low-level, hardware dependent stuff are done by U-Boot 2994 2995- the same Linux kernel image can now be used with different "initrd" 2996 images; of course this also means that different kernel images can 2997 be run with the same "initrd". This makes testing easier (you don't 2998 have to build a new "zImage.initrd" Linux image when you just 2999 change a file in your "initrd"). Also, a field-upgrade of the 3000 software is easier now. 3001 3002 3003Linux HOWTO: 3004============ 3005 3006Porting Linux to U-Boot based systems: 3007--------------------------------------- 3008 3009U-Boot cannot save you from doing all the necessary modifications to 3010configure the Linux device drivers for use with your target hardware 3011(no, we don't intend to provide a full virtual machine interface to 3012Linux :-). 3013 3014But now you can ignore ALL boot loader code (in arch/ppc/mbxboot). 3015 3016Just make sure your machine specific header file (for instance 3017include/asm-ppc/tqm8xx.h) includes the same definition of the Board 3018Information structure as we define in include/u-boot.h, and make 3019sure that your definition of IMAP_ADDR uses the same value as your 3020U-Boot configuration in CFG_IMMR. 3021 3022 3023Configuring the Linux kernel: 3024----------------------------- 3025 3026No specific requirements for U-Boot. Make sure you have some root 3027device (initial ramdisk, NFS) for your target system. 3028 3029 3030Building a Linux Image: 3031----------------------- 3032 3033With U-Boot, "normal" build targets like "zImage" or "bzImage" are 3034not used. If you use recent kernel source, a new build target 3035"uImage" will exist which automatically builds an image usable by 3036U-Boot. Most older kernels also have support for a "pImage" target, 3037which was introduced for our predecessor project PPCBoot and uses a 3038100% compatible format. 3039 3040Example: 3041 3042 make TQM850L_config 3043 make oldconfig 3044 make dep 3045 make uImage 3046 3047The "uImage" build target uses a special tool (in 'tools/mkimage') to 3048encapsulate a compressed Linux kernel image with header information, 3049CRC32 checksum etc. for use with U-Boot. This is what we are doing: 3050 3051* build a standard "vmlinux" kernel image (in ELF binary format): 3052 3053* convert the kernel into a raw binary image: 3054 3055 ${CROSS_COMPILE}-objcopy -O binary \ 3056 -R .note -R .comment \ 3057 -S vmlinux linux.bin 3058 3059* compress the binary image: 3060 3061 gzip -9 linux.bin 3062 3063* package compressed binary image for U-Boot: 3064 3065 mkimage -A ppc -O linux -T kernel -C gzip \ 3066 -a 0 -e 0 -n "Linux Kernel Image" \ 3067 -d linux.bin.gz uImage 3068 3069 3070The "mkimage" tool can also be used to create ramdisk images for use 3071with U-Boot, either separated from the Linux kernel image, or 3072combined into one file. "mkimage" encapsulates the images with a 64 3073byte header containing information about target architecture, 3074operating system, image type, compression method, entry points, time 3075stamp, CRC32 checksums, etc. 3076 3077"mkimage" can be called in two ways: to verify existing images and 3078print the header information, or to build new images. 3079 3080In the first form (with "-l" option) mkimage lists the information 3081contained in the header of an existing U-Boot image; this includes 3082checksum verification: 3083 3084 tools/mkimage -l image 3085 -l ==> list image header information 3086 3087The second form (with "-d" option) is used to build a U-Boot image 3088from a "data file" which is used as image payload: 3089 3090 tools/mkimage -A arch -O os -T type -C comp -a addr -e ep \ 3091 -n name -d data_file image 3092 -A ==> set architecture to 'arch' 3093 -O ==> set operating system to 'os' 3094 -T ==> set image type to 'type' 3095 -C ==> set compression type 'comp' 3096 -a ==> set load address to 'addr' (hex) 3097 -e ==> set entry point to 'ep' (hex) 3098 -n ==> set image name to 'name' 3099 -d ==> use image data from 'datafile' 3100 3101Right now, all Linux kernels for PowerPC systems use the same load 3102address (0x00000000), but the entry point address depends on the 3103kernel version: 3104 3105- 2.2.x kernels have the entry point at 0x0000000C, 3106- 2.3.x and later kernels have the entry point at 0x00000000. 3107 3108So a typical call to build a U-Boot image would read: 3109 3110 -> tools/mkimage -n '2.4.4 kernel for TQM850L' \ 3111 > -A ppc -O linux -T kernel -C gzip -a 0 -e 0 \ 3112 > -d /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/ppc/coffboot/vmlinux.gz \ 3113 > examples/uImage.TQM850L 3114 Image Name: 2.4.4 kernel for TQM850L 3115 Created: Wed Jul 19 02:34:59 2000 3116 Image Type: PowerPC Linux Kernel Image (gzip compressed) 3117 Data Size: 335725 Bytes = 327.86 kB = 0.32 MB 3118 Load Address: 0x00000000 3119 Entry Point: 0x00000000 3120 3121To verify the contents of the image (or check for corruption): 3122 3123 -> tools/mkimage -l examples/uImage.TQM850L 3124 Image Name: 2.4.4 kernel for TQM850L 3125 Created: Wed Jul 19 02:34:59 2000 3126 Image Type: PowerPC Linux Kernel Image (gzip compressed) 3127 Data Size: 335725 Bytes = 327.86 kB = 0.32 MB 3128 Load Address: 0x00000000 3129 Entry Point: 0x00000000 3130 3131NOTE: for embedded systems where boot time is critical you can trade 3132speed for memory and install an UNCOMPRESSED image instead: this 3133needs more space in Flash, but boots much faster since it does not 3134need to be uncompressed: 3135 3136 -> gunzip /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/ppc/coffboot/vmlinux.gz 3137 -> tools/mkimage -n '2.4.4 kernel for TQM850L' \ 3138 > -A ppc -O linux -T kernel -C none -a 0 -e 0 \ 3139 > -d /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/ppc/coffboot/vmlinux \ 3140 > examples/uImage.TQM850L-uncompressed 3141 Image Name: 2.4.4 kernel for TQM850L 3142 Created: Wed Jul 19 02:34:59 2000 3143 Image Type: PowerPC Linux Kernel Image (uncompressed) 3144 Data Size: 792160 Bytes = 773.59 kB = 0.76 MB 3145 Load Address: 0x00000000 3146 Entry Point: 0x00000000 3147 3148 3149Similar you can build U-Boot images from a 'ramdisk.image.gz' file 3150when your kernel is intended to use an initial ramdisk: 3151 3152 -> tools/mkimage -n 'Simple Ramdisk Image' \ 3153 > -A ppc -O linux -T ramdisk -C gzip \ 3154 > -d /LinuxPPC/images/SIMPLE-ramdisk.image.gz examples/simple-initrd 3155 Image Name: Simple Ramdisk Image 3156 Created: Wed Jan 12 14:01:50 2000 3157 Image Type: PowerPC Linux RAMDisk Image (gzip compressed) 3158 Data Size: 566530 Bytes = 553.25 kB = 0.54 MB 3159 Load Address: 0x00000000 3160 Entry Point: 0x00000000 3161 3162 3163Installing a Linux Image: 3164------------------------- 3165 3166To downloading a U-Boot image over the serial (console) interface, 3167you must convert the image to S-Record format: 3168 3169 objcopy -I binary -O srec examples/image examples/image.srec 3170 3171The 'objcopy' does not understand the information in the U-Boot 3172image header, so the resulting S-Record file will be relative to 3173address 0x00000000. To load it to a given address, you need to 3174specify the target address as 'offset' parameter with the 'loads' 3175command. 3176 3177Example: install the image to address 0x40100000 (which on the 3178TQM8xxL is in the first Flash bank): 3179 3180 => erase 40100000 401FFFFF 3181 3182 .......... done 3183 Erased 8 sectors 3184 3185 => loads 40100000 3186 ## Ready for S-Record download ... 3187 ~>examples/image.srec 3188 1 2 3 4 5 6 7 8 9 10 11 12 13 ... 3189 ... 3190 15989 15990 15991 15992 3191 [file transfer complete] 3192 [connected] 3193 ## Start Addr = 0x00000000 3194 3195 3196You can check the success of the download using the 'iminfo' command; 3197this includes a checksum verification so you can be sure no data 3198corruption happened: 3199 3200 => imi 40100000 3201 3202 ## Checking Image at 40100000 ... 3203 Image Name: 2.2.13 for initrd on TQM850L 3204 Image Type: PowerPC Linux Kernel Image (gzip compressed) 3205 Data Size: 335725 Bytes = 327 kB = 0 MB 3206 Load Address: 00000000 3207 Entry Point: 0000000c 3208 Verifying Checksum ... OK 3209 3210 3211Boot Linux: 3212----------- 3213 3214The "bootm" command is used to boot an application that is stored in 3215memory (RAM or Flash). In case of a Linux kernel image, the contents 3216of the "bootargs" environment variable is passed to the kernel as 3217parameters. You can check and modify this variable using the 3218"printenv" and "setenv" commands: 3219 3220 3221 => printenv bootargs 3222 bootargs=root=/dev/ram 3223 3224 => setenv bootargs root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2 3225 3226 => printenv bootargs 3227 bootargs=root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2 3228 3229 => bootm 40020000 3230 ## Booting Linux kernel at 40020000 ... 3231 Image Name: 2.2.13 for NFS on TQM850L 3232 Image Type: PowerPC Linux Kernel Image (gzip compressed) 3233 Data Size: 381681 Bytes = 372 kB = 0 MB 3234 Load Address: 00000000 3235 Entry Point: 0000000c 3236 Verifying Checksum ... OK 3237 Uncompressing Kernel Image ... OK 3238 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 3239 Boot arguments: root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2 3240 time_init: decrementer frequency = 187500000/60 3241 Calibrating delay loop... 49.77 BogoMIPS 3242 Memory: 15208k available (700k kernel code, 444k data, 32k init) [c0000000,c1000000] 3243 ... 3244 3245If you want to boot a Linux kernel with initial ram disk, you pass 3246the memory addresses of both the kernel and the initrd image (PPBCOOT 3247format!) to the "bootm" command: 3248 3249 => imi 40100000 40200000 3250 3251 ## Checking Image at 40100000 ... 3252 Image Name: 2.2.13 for initrd on TQM850L 3253 Image Type: PowerPC Linux Kernel Image (gzip compressed) 3254 Data Size: 335725 Bytes = 327 kB = 0 MB 3255 Load Address: 00000000 3256 Entry Point: 0000000c 3257 Verifying Checksum ... OK 3258 3259 ## Checking Image at 40200000 ... 3260 Image Name: Simple Ramdisk Image 3261 Image Type: PowerPC Linux RAMDisk Image (gzip compressed) 3262 Data Size: 566530 Bytes = 553 kB = 0 MB 3263 Load Address: 00000000 3264 Entry Point: 00000000 3265 Verifying Checksum ... OK 3266 3267 => bootm 40100000 40200000 3268 ## Booting Linux kernel at 40100000 ... 3269 Image Name: 2.2.13 for initrd on TQM850L 3270 Image Type: PowerPC Linux Kernel Image (gzip compressed) 3271 Data Size: 335725 Bytes = 327 kB = 0 MB 3272 Load Address: 00000000 3273 Entry Point: 0000000c 3274 Verifying Checksum ... OK 3275 Uncompressing Kernel Image ... OK 3276 ## Loading RAMDisk Image at 40200000 ... 3277 Image Name: Simple Ramdisk Image 3278 Image Type: PowerPC Linux RAMDisk Image (gzip compressed) 3279 Data Size: 566530 Bytes = 553 kB = 0 MB 3280 Load Address: 00000000 3281 Entry Point: 00000000 3282 Verifying Checksum ... OK 3283 Loading Ramdisk ... OK 3284 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 3285 Boot arguments: root=/dev/ram 3286 time_init: decrementer frequency = 187500000/60 3287 Calibrating delay loop... 49.77 BogoMIPS 3288 ... 3289 RAMDISK: Compressed image found at block 0 3290 VFS: Mounted root (ext2 filesystem). 3291 3292 bash# 3293 3294Boot Linux and pass a flat device tree: 3295----------- 3296 3297First, U-Boot must be compiled with the appropriate defines. See the section 3298titled "Linux Kernel Interface" above for a more in depth explanation. The 3299following is an example of how to start a kernel and pass an updated 3300flat device tree: 3301 3302=> print oftaddr 3303oftaddr=0x300000 3304=> print oft 3305oft=oftrees/mpc8540ads.dtb 3306=> tftp $oftaddr $oft 3307Speed: 1000, full duplex 3308Using TSEC0 device 3309TFTP from server 192.168.1.1; our IP address is 192.168.1.101 3310Filename 'oftrees/mpc8540ads.dtb'. 3311Load address: 0x300000 3312Loading: # 3313done 3314Bytes transferred = 4106 (100a hex) 3315=> tftp $loadaddr $bootfile 3316Speed: 1000, full duplex 3317Using TSEC0 device 3318TFTP from server 192.168.1.1; our IP address is 192.168.1.2 3319Filename 'uImage'. 3320Load address: 0x200000 3321Loading:############ 3322done 3323Bytes transferred = 1029407 (fb51f hex) 3324=> print loadaddr 3325loadaddr=200000 3326=> print oftaddr 3327oftaddr=0x300000 3328=> bootm $loadaddr - $oftaddr 3329## Booting image at 00200000 ... 3330 Image Name: Linux-2.6.17-dirty 3331 Image Type: PowerPC Linux Kernel Image (gzip compressed) 3332 Data Size: 1029343 Bytes = 1005.2 kB 3333 Load Address: 00000000 3334 Entry Point: 00000000 3335 Verifying Checksum ... OK 3336 Uncompressing Kernel Image ... OK 3337Booting using flat device tree at 0x300000 3338Using MPC85xx ADS machine description 3339Memory CAM mapping: CAM0=256Mb, CAM1=256Mb, CAM2=0Mb residual: 0Mb 3340[snip] 3341 3342 3343More About U-Boot Image Types: 3344------------------------------ 3345 3346U-Boot supports the following image types: 3347 3348 "Standalone Programs" are directly runnable in the environment 3349 provided by U-Boot; it is expected that (if they behave 3350 well) you can continue to work in U-Boot after return from 3351 the Standalone Program. 3352 "OS Kernel Images" are usually images of some Embedded OS which 3353 will take over control completely. Usually these programs 3354 will install their own set of exception handlers, device 3355 drivers, set up the MMU, etc. - this means, that you cannot 3356 expect to re-enter U-Boot except by resetting the CPU. 3357 "RAMDisk Images" are more or less just data blocks, and their 3358 parameters (address, size) are passed to an OS kernel that is 3359 being started. 3360 "Multi-File Images" contain several images, typically an OS 3361 (Linux) kernel image and one or more data images like 3362 RAMDisks. This construct is useful for instance when you want 3363 to boot over the network using BOOTP etc., where the boot 3364 server provides just a single image file, but you want to get 3365 for instance an OS kernel and a RAMDisk image. 3366 3367 "Multi-File Images" start with a list of image sizes, each 3368 image size (in bytes) specified by an "uint32_t" in network 3369 byte order. This list is terminated by an "(uint32_t)0". 3370 Immediately after the terminating 0 follow the images, one by 3371 one, all aligned on "uint32_t" boundaries (size rounded up to 3372 a multiple of 4 bytes). 3373 3374 "Firmware Images" are binary images containing firmware (like 3375 U-Boot or FPGA images) which usually will be programmed to 3376 flash memory. 3377 3378 "Script files" are command sequences that will be executed by 3379 U-Boot's command interpreter; this feature is especially 3380 useful when you configure U-Boot to use a real shell (hush) 3381 as command interpreter. 3382 3383 3384Standalone HOWTO: 3385================= 3386 3387One of the features of U-Boot is that you can dynamically load and 3388run "standalone" applications, which can use some resources of 3389U-Boot like console I/O functions or interrupt services. 3390 3391Two simple examples are included with the sources: 3392 3393"Hello World" Demo: 3394------------------- 3395 3396'examples/hello_world.c' contains a small "Hello World" Demo 3397application; it is automatically compiled when you build U-Boot. 3398It's configured to run at address 0x00040004, so you can play with it 3399like that: 3400 3401 => loads 3402 ## Ready for S-Record download ... 3403 ~>examples/hello_world.srec 3404 1 2 3 4 5 6 7 8 9 10 11 ... 3405 [file transfer complete] 3406 [connected] 3407 ## Start Addr = 0x00040004 3408 3409 => go 40004 Hello World! This is a test. 3410 ## Starting application at 0x00040004 ... 3411 Hello World 3412 argc = 7 3413 argv[0] = "40004" 3414 argv[1] = "Hello" 3415 argv[2] = "World!" 3416 argv[3] = "This" 3417 argv[4] = "is" 3418 argv[5] = "a" 3419 argv[6] = "test." 3420 argv[7] = "<NULL>" 3421 Hit any key to exit ... 3422 3423 ## Application terminated, rc = 0x0 3424 3425Another example, which demonstrates how to register a CPM interrupt 3426handler with the U-Boot code, can be found in 'examples/timer.c'. 3427Here, a CPM timer is set up to generate an interrupt every second. 3428The interrupt service routine is trivial, just printing a '.' 3429character, but this is just a demo program. The application can be 3430controlled by the following keys: 3431 3432 ? - print current values og the CPM Timer registers 3433 b - enable interrupts and start timer 3434 e - stop timer and disable interrupts 3435 q - quit application 3436 3437 => loads 3438 ## Ready for S-Record download ... 3439 ~>examples/timer.srec 3440 1 2 3 4 5 6 7 8 9 10 11 ... 3441 [file transfer complete] 3442 [connected] 3443 ## Start Addr = 0x00040004 3444 3445 => go 40004 3446 ## Starting application at 0x00040004 ... 3447 TIMERS=0xfff00980 3448 Using timer 1 3449 tgcr @ 0xfff00980, tmr @ 0xfff00990, trr @ 0xfff00994, tcr @ 0xfff00998, tcn @ 0xfff0099c, ter @ 0xfff009b0 3450 3451Hit 'b': 3452 [q, b, e, ?] Set interval 1000000 us 3453 Enabling timer 3454Hit '?': 3455 [q, b, e, ?] ........ 3456 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0xef6, ter=0x0 3457Hit '?': 3458 [q, b, e, ?] . 3459 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x2ad4, ter=0x0 3460Hit '?': 3461 [q, b, e, ?] . 3462 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x1efc, ter=0x0 3463Hit '?': 3464 [q, b, e, ?] . 3465 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x169d, ter=0x0 3466Hit 'e': 3467 [q, b, e, ?] ...Stopping timer 3468Hit 'q': 3469 [q, b, e, ?] ## Application terminated, rc = 0x0 3470 3471 3472Minicom warning: 3473================ 3474 3475Over time, many people have reported problems when trying to use the 3476"minicom" terminal emulation program for serial download. I (wd) 3477consider minicom to be broken, and recommend not to use it. Under 3478Unix, I recommend to use C-Kermit for general purpose use (and 3479especially for kermit binary protocol download ("loadb" command), and 3480use "cu" for S-Record download ("loads" command). 3481 3482Nevertheless, if you absolutely want to use it try adding this 3483configuration to your "File transfer protocols" section: 3484 3485 Name Program Name U/D FullScr IO-Red. Multi 3486 X kermit /usr/bin/kermit -i -l %l -s Y U Y N N 3487 Y kermit /usr/bin/kermit -i -l %l -r N D Y N N 3488 3489 3490NetBSD Notes: 3491============= 3492 3493Starting at version 0.9.2, U-Boot supports NetBSD both as host 3494(build U-Boot) and target system (boots NetBSD/mpc8xx). 3495 3496Building requires a cross environment; it is known to work on 3497NetBSD/i386 with the cross-powerpc-netbsd-1.3 package (you will also 3498need gmake since the Makefiles are not compatible with BSD make). 3499Note that the cross-powerpc package does not install include files; 3500attempting to build U-Boot will fail because <machine/ansi.h> is 3501missing. This file has to be installed and patched manually: 3502 3503 # cd /usr/pkg/cross/powerpc-netbsd/include 3504 # mkdir powerpc 3505 # ln -s powerpc machine 3506 # cp /usr/src/sys/arch/powerpc/include/ansi.h powerpc/ansi.h 3507 # ${EDIT} powerpc/ansi.h ## must remove __va_list, _BSD_VA_LIST 3508 3509Native builds *don't* work due to incompatibilities between native 3510and U-Boot include files. 3511 3512Booting assumes that (the first part of) the image booted is a 3513stage-2 loader which in turn loads and then invokes the kernel 3514proper. Loader sources will eventually appear in the NetBSD source 3515tree (probably in sys/arc/mpc8xx/stand/u-boot_stage2/); in the 3516meantime, see ftp://ftp.denx.de/pub/u-boot/ppcboot_stage2.tar.gz 3517 3518 3519Implementation Internals: 3520========================= 3521 3522The following is not intended to be a complete description of every 3523implementation detail. However, it should help to understand the 3524inner workings of U-Boot and make it easier to port it to custom 3525hardware. 3526 3527 3528Initial Stack, Global Data: 3529--------------------------- 3530 3531The implementation of U-Boot is complicated by the fact that U-Boot 3532starts running out of ROM (flash memory), usually without access to 3533system RAM (because the memory controller is not initialized yet). 3534This means that we don't have writable Data or BSS segments, and BSS 3535is not initialized as zero. To be able to get a C environment working 3536at all, we have to allocate at least a minimal stack. Implementation 3537options for this are defined and restricted by the CPU used: Some CPU 3538models provide on-chip memory (like the IMMR area on MPC8xx and 3539MPC826x processors), on others (parts of) the data cache can be 3540locked as (mis-) used as memory, etc. 3541 3542 Chris Hallinan posted a good summary of these issues to the 3543 u-boot-users mailing list: 3544 3545 Subject: RE: [U-Boot-Users] RE: More On Memory Bank x (nothingness)? 3546 From: "Chris Hallinan" <clh@net1plus.com> 3547 Date: Mon, 10 Feb 2003 16:43:46 -0500 (22:43 MET) 3548 ... 3549 3550 Correct me if I'm wrong, folks, but the way I understand it 3551 is this: Using DCACHE as initial RAM for Stack, etc, does not 3552 require any physical RAM backing up the cache. The cleverness 3553 is that the cache is being used as a temporary supply of 3554 necessary storage before the SDRAM controller is setup. It's 3555 beyond the scope of this list to expain the details, but you 3556 can see how this works by studying the cache architecture and 3557 operation in the architecture and processor-specific manuals. 3558 3559 OCM is On Chip Memory, which I believe the 405GP has 4K. It 3560 is another option for the system designer to use as an 3561 initial stack/ram area prior to SDRAM being available. Either 3562 option should work for you. Using CS 4 should be fine if your 3563 board designers haven't used it for something that would 3564 cause you grief during the initial boot! It is frequently not 3565 used. 3566 3567 CFG_INIT_RAM_ADDR should be somewhere that won't interfere 3568 with your processor/board/system design. The default value 3569 you will find in any recent u-boot distribution in 3570 walnut.h should work for you. I'd set it to a value larger 3571 than your SDRAM module. If you have a 64MB SDRAM module, set 3572 it above 400_0000. Just make sure your board has no resources 3573 that are supposed to respond to that address! That code in 3574 start.S has been around a while and should work as is when 3575 you get the config right. 3576 3577 -Chris Hallinan 3578 DS4.COM, Inc. 3579 3580It is essential to remember this, since it has some impact on the C 3581code for the initialization procedures: 3582 3583* Initialized global data (data segment) is read-only. Do not attempt 3584 to write it. 3585 3586* Do not use any unitialized global data (or implicitely initialized 3587 as zero data - BSS segment) at all - this is undefined, initiali- 3588 zation is performed later (when relocating to RAM). 3589 3590* Stack space is very limited. Avoid big data buffers or things like 3591 that. 3592 3593Having only the stack as writable memory limits means we cannot use 3594normal global data to share information beween the code. But it 3595turned out that the implementation of U-Boot can be greatly 3596simplified by making a global data structure (gd_t) available to all 3597functions. We could pass a pointer to this data as argument to _all_ 3598functions, but this would bloat the code. Instead we use a feature of 3599the GCC compiler (Global Register Variables) to share the data: we 3600place a pointer (gd) to the global data into a register which we 3601reserve for this purpose. 3602 3603When choosing a register for such a purpose we are restricted by the 3604relevant (E)ABI specifications for the current architecture, and by 3605GCC's implementation. 3606 3607For PowerPC, the following registers have specific use: 3608 R1: stack pointer 3609 R2: reserved for system use 3610 R3-R4: parameter passing and return values 3611 R5-R10: parameter passing 3612 R13: small data area pointer 3613 R30: GOT pointer 3614 R31: frame pointer 3615 3616 (U-Boot also uses R14 as internal GOT pointer.) 3617 3618 ==> U-Boot will use R2 to hold a pointer to the global data 3619 3620 Note: on PPC, we could use a static initializer (since the 3621 address of the global data structure is known at compile time), 3622 but it turned out that reserving a register results in somewhat 3623 smaller code - although the code savings are not that big (on 3624 average for all boards 752 bytes for the whole U-Boot image, 3625 624 text + 127 data). 3626 3627On Blackfin, the normal C ABI (except for P5) is followed as documented here: 3628 http://docs.blackfin.uclinux.org/doku.php?id=application_binary_interface 3629 3630 ==> U-Boot will use P5 to hold a pointer to the global data 3631 3632On ARM, the following registers are used: 3633 3634 R0: function argument word/integer result 3635 R1-R3: function argument word 3636 R9: GOT pointer 3637 R10: stack limit (used only if stack checking if enabled) 3638 R11: argument (frame) pointer 3639 R12: temporary workspace 3640 R13: stack pointer 3641 R14: link register 3642 R15: program counter 3643 3644 ==> U-Boot will use R8 to hold a pointer to the global data 3645 3646NOTE: DECLARE_GLOBAL_DATA_PTR must be used with file-global scope, 3647or current versions of GCC may "optimize" the code too much. 3648 3649Memory Management: 3650------------------ 3651 3652U-Boot runs in system state and uses physical addresses, i.e. the 3653MMU is not used either for address mapping nor for memory protection. 3654 3655The available memory is mapped to fixed addresses using the memory 3656controller. In this process, a contiguous block is formed for each 3657memory type (Flash, SDRAM, SRAM), even when it consists of several 3658physical memory banks. 3659 3660U-Boot is installed in the first 128 kB of the first Flash bank (on 3661TQM8xxL modules this is the range 0x40000000 ... 0x4001FFFF). After 3662booting and sizing and initializing DRAM, the code relocates itself 3663to the upper end of DRAM. Immediately below the U-Boot code some 3664memory is reserved for use by malloc() [see CFG_MALLOC_LEN 3665configuration setting]. Below that, a structure with global Board 3666Info data is placed, followed by the stack (growing downward). 3667 3668Additionally, some exception handler code is copied to the low 8 kB 3669of DRAM (0x00000000 ... 0x00001FFF). 3670 3671So a typical memory configuration with 16 MB of DRAM could look like 3672this: 3673 3674 0x0000 0000 Exception Vector code 3675 : 3676 0x0000 1FFF 3677 0x0000 2000 Free for Application Use 3678 : 3679 : 3680 3681 : 3682 : 3683 0x00FB FF20 Monitor Stack (Growing downward) 3684 0x00FB FFAC Board Info Data and permanent copy of global data 3685 0x00FC 0000 Malloc Arena 3686 : 3687 0x00FD FFFF 3688 0x00FE 0000 RAM Copy of Monitor Code 3689 ... eventually: LCD or video framebuffer 3690 ... eventually: pRAM (Protected RAM - unchanged by reset) 3691 0x00FF FFFF [End of RAM] 3692 3693 3694System Initialization: 3695---------------------- 3696 3697In the reset configuration, U-Boot starts at the reset entry point 3698(on most PowerPC systens at address 0x00000100). Because of the reset 3699configuration for CS0# this is a mirror of the onboard Flash memory. 3700To be able to re-map memory U-Boot then jumps to its link address. 3701To be able to implement the initialization code in C, a (small!) 3702initial stack is set up in the internal Dual Ported RAM (in case CPUs 3703which provide such a feature like MPC8xx or MPC8260), or in a locked 3704part of the data cache. After that, U-Boot initializes the CPU core, 3705the caches and the SIU. 3706 3707Next, all (potentially) available memory banks are mapped using a 3708preliminary mapping. For example, we put them on 512 MB boundaries 3709(multiples of 0x20000000: SDRAM on 0x00000000 and 0x20000000, Flash 3710on 0x40000000 and 0x60000000, SRAM on 0x80000000). Then UPM A is 3711programmed for SDRAM access. Using the temporary configuration, a 3712simple memory test is run that determines the size of the SDRAM 3713banks. 3714 3715When there is more than one SDRAM bank, and the banks are of 3716different size, the largest is mapped first. For equal size, the first 3717bank (CS2#) is mapped first. The first mapping is always for address 37180x00000000, with any additional banks following immediately to create 3719contiguous memory starting from 0. 3720 3721Then, the monitor installs itself at the upper end of the SDRAM area 3722and allocates memory for use by malloc() and for the global Board 3723Info data; also, the exception vector code is copied to the low RAM 3724pages, and the final stack is set up. 3725 3726Only after this relocation will you have a "normal" C environment; 3727until that you are restricted in several ways, mostly because you are 3728running from ROM, and because the code will have to be relocated to a 3729new address in RAM. 3730 3731 3732U-Boot Porting Guide: 3733---------------------- 3734 3735[Based on messages by Jerry Van Baren in the U-Boot-Users mailing 3736list, October 2002] 3737 3738 3739int main (int argc, char *argv[]) 3740{ 3741 sighandler_t no_more_time; 3742 3743 signal (SIGALRM, no_more_time); 3744 alarm (PROJECT_DEADLINE - toSec (3 * WEEK)); 3745 3746 if (available_money > available_manpower) { 3747 pay consultant to port U-Boot; 3748 return 0; 3749 } 3750 3751 Download latest U-Boot source; 3752 3753 Subscribe to u-boot-users mailing list; 3754 3755 if (clueless) { 3756 email ("Hi, I am new to U-Boot, how do I get started?"); 3757 } 3758 3759 while (learning) { 3760 Read the README file in the top level directory; 3761 Read http://www.denx.de/twiki/bin/view/DULG/Manual ; 3762 Read the source, Luke; 3763 } 3764 3765 if (available_money > toLocalCurrency ($2500)) { 3766 Buy a BDI2000; 3767 } else { 3768 Add a lot of aggravation and time; 3769 } 3770 3771 Create your own board support subdirectory; 3772 3773 Create your own board config file; 3774 3775 while (!running) { 3776 do { 3777 Add / modify source code; 3778 } until (compiles); 3779 Debug; 3780 if (clueless) 3781 email ("Hi, I am having problems..."); 3782 } 3783 Send patch file to Wolfgang; 3784 3785 return 0; 3786} 3787 3788void no_more_time (int sig) 3789{ 3790 hire_a_guru(); 3791} 3792 3793 3794Coding Standards: 3795----------------- 3796 3797All contributions to U-Boot should conform to the Linux kernel 3798coding style; see the file "Documentation/CodingStyle" and the script 3799"scripts/Lindent" in your Linux kernel source directory. In sources 3800originating from U-Boot a style corresponding to "Lindent -pcs" (adding 3801spaces before parameters to function calls) is actually used. 3802 3803Source files originating from a different project (for example the 3804MTD subsystem) are generally exempt from these guidelines and are not 3805reformated to ease subsequent migration to newer versions of those 3806sources. 3807 3808Please note that U-Boot is implemented in C (and to some small parts in 3809Assembler); no C++ is used, so please do not use C++ style comments (//) 3810in your code. 3811 3812Please also stick to the following formatting rules: 3813- remove any trailing white space 3814- use TAB characters for indentation, not spaces 3815- make sure NOT to use DOS '\r\n' line feeds 3816- do not add more than 2 empty lines to source files 3817- do not add trailing empty lines to source files 3818 3819Submissions which do not conform to the standards may be returned 3820with a request to reformat the changes. 3821 3822 3823Submitting Patches: 3824------------------- 3825 3826Since the number of patches for U-Boot is growing, we need to 3827establish some rules. Submissions which do not conform to these rules 3828may be rejected, even when they contain important and valuable stuff. 3829 3830Patches shall be sent to the u-boot-users mailing list. 3831 3832Please see http://www.denx.de/wiki/UBoot/Patches for details. 3833 3834When you send a patch, please include the following information with 3835it: 3836 3837* For bug fixes: a description of the bug and how your patch fixes 3838 this bug. Please try to include a way of demonstrating that the 3839 patch actually fixes something. 3840 3841* For new features: a description of the feature and your 3842 implementation. 3843 3844* A CHANGELOG entry as plaintext (separate from the patch) 3845 3846* For major contributions, your entry to the CREDITS file 3847 3848* When you add support for a new board, don't forget to add this 3849 board to the MAKEALL script, too. 3850 3851* If your patch adds new configuration options, don't forget to 3852 document these in the README file. 3853 3854* The patch itself. If you are using git (which is *strongly* 3855 recommended) you can easily generate the patch using the 3856 "git-format-patch". If you then use "git-send-email" to send it to 3857 the U-Boot mailing list, you will avoid most of the common problems 3858 with some other mail clients. 3859 3860 If you cannot use git, use "diff -purN OLD NEW". If your version of 3861 diff does not support these options, then get the latest version of 3862 GNU diff. 3863 3864 The current directory when running this command shall be the parent 3865 directory of the U-Boot source tree (i. e. please make sure that 3866 your patch includes sufficient directory information for the 3867 affected files). 3868 3869 We prefer patches as plain text. MIME attachments are discouraged, 3870 and compressed attachments must not be used. 3871 3872* If one logical set of modifications affects or creates several 3873 files, all these changes shall be submitted in a SINGLE patch file. 3874 3875* Changesets that contain different, unrelated modifications shall be 3876 submitted as SEPARATE patches, one patch per changeset. 3877 3878 3879Notes: 3880 3881* Before sending the patch, run the MAKEALL script on your patched 3882 source tree and make sure that no errors or warnings are reported 3883 for any of the boards. 3884 3885* Keep your modifications to the necessary minimum: A patch 3886 containing several unrelated changes or arbitrary reformats will be 3887 returned with a request to re-formatting / split it. 3888 3889* If you modify existing code, make sure that your new code does not 3890 add to the memory footprint of the code ;-) Small is beautiful! 3891 When adding new features, these should compile conditionally only 3892 (using #ifdef), and the resulting code with the new feature 3893 disabled must not need more memory than the old code without your 3894 modification. 3895 3896* Remember that there is a size limit of 40 kB per message on the 3897 u-boot-users mailing list. Bigger patches will be moderated. If 3898 they are reasonable and not bigger than 100 kB, they will be 3899 acknowledged. Even bigger patches should be avoided. 3900