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 - leon3 Files specific to Gaisler LEON3 SPARC CPU 157 - mcf52x2 Files specific to Freescale ColdFire MCF52x2 CPUs 158 - mcf5227x Files specific to Freescale ColdFire MCF5227x CPUs 159 - mcf532x Files specific to Freescale ColdFire MCF5329 CPUs 160 - mcf5445x Files specific to Freescale ColdFire MCF5445x CPUs 161 - mcf547x_8x Files specific to Freescale ColdFire MCF547x_8x CPUs 162 - mips Files specific to MIPS CPUs 163 - mpc5xx Files specific to Freescale MPC5xx CPUs 164 - mpc5xxx Files specific to Freescale MPC5xxx CPUs 165 - mpc8xx Files specific to Freescale MPC8xx CPUs 166 - mpc8220 Files specific to Freescale MPC8220 CPUs 167 - mpc824x Files specific to Freescale MPC824x CPUs 168 - mpc8260 Files specific to Freescale MPC8260 CPUs 169 - mpc85xx Files specific to Freescale MPC85xx CPUs 170 - nios Files specific to Altera NIOS CPUs 171 - nios2 Files specific to Altera Nios-II CPUs 172 - ppc4xx Files specific to AMCC PowerPC 4xx CPUs 173 - pxa Files specific to Intel XScale PXA CPUs 174 - s3c44b0 Files specific to Samsung S3C44B0 CPUs 175 - sa1100 Files specific to Intel StrongARM SA1100 CPUs 176- disk Code for disk drive partition handling 177- doc Documentation (don't expect too much) 178- drivers Commonly used device drivers 179- dtt Digital Thermometer and Thermostat drivers 180- examples Example code for standalone applications, etc. 181- include Header Files 182- lib_arm Files generic to ARM architecture 183- lib_avr32 Files generic to AVR32 architecture 184- lib_generic Files generic to all architectures 185- lib_i386 Files generic to i386 architecture 186- lib_m68k Files generic to m68k architecture 187- lib_mips Files generic to MIPS architecture 188- lib_nios Files generic to NIOS architecture 189- lib_ppc Files generic to PowerPC architecture 190- lib_sparc Files generic to SPARC architecture 191- libfdt Library files to support flattened device trees 192- net Networking code 193- post Power On Self Test 194- rtc Real Time Clock drivers 195- tools Tools to build S-Record or U-Boot images, etc. 196 197Software Configuration: 198======================= 199 200Configuration is usually done using C preprocessor defines; the 201rationale behind that is to avoid dead code whenever possible. 202 203There are two classes of configuration variables: 204 205* Configuration _OPTIONS_: 206 These are selectable by the user and have names beginning with 207 "CONFIG_". 208 209* Configuration _SETTINGS_: 210 These depend on the hardware etc. and should not be meddled with if 211 you don't know what you're doing; they have names beginning with 212 "CFG_". 213 214Later we will add a configuration tool - probably similar to or even 215identical to what's used for the Linux kernel. Right now, we have to 216do the configuration by hand, which means creating some symbolic 217links and editing some configuration files. We use the TQM8xxL boards 218as an example here. 219 220 221Selection of Processor Architecture and Board Type: 222--------------------------------------------------- 223 224For all supported boards there are ready-to-use default 225configurations available; just type "make <board_name>_config". 226 227Example: For a TQM823L module type: 228 229 cd u-boot 230 make TQM823L_config 231 232For the Cogent platform, you need to specify the cpu type as well; 233e.g. "make cogent_mpc8xx_config". And also configure the cogent 234directory according to the instructions in cogent/README. 235 236 237Configuration Options: 238---------------------- 239 240Configuration depends on the combination of board and CPU type; all 241such information is kept in a configuration file 242"include/configs/<board_name>.h". 243 244Example: For a TQM823L module, all configuration settings are in 245"include/configs/TQM823L.h". 246 247 248Many of the options are named exactly as the corresponding Linux 249kernel configuration options. The intention is to make it easier to 250build a config tool - later. 251 252 253The following options need to be configured: 254 255- CPU Type: Define exactly one, e.g. CONFIG_MPC85XX. 256 257- Board Type: Define exactly one, e.g. CONFIG_MPC8540ADS. 258 259- CPU Daughterboard Type: (if CONFIG_ATSTK1000 is defined) 260 Define exactly one, e.g. CONFIG_ATSTK1002 261 262- CPU Module Type: (if CONFIG_COGENT is defined) 263 Define exactly one of 264 CONFIG_CMA286_60_OLD 265--- FIXME --- not tested yet: 266 CONFIG_CMA286_60, CONFIG_CMA286_21, CONFIG_CMA286_60P, 267 CONFIG_CMA287_23, CONFIG_CMA287_50 268 269- Motherboard Type: (if CONFIG_COGENT is defined) 270 Define exactly one of 271 CONFIG_CMA101, CONFIG_CMA102 272 273- Motherboard I/O Modules: (if CONFIG_COGENT is defined) 274 Define one or more of 275 CONFIG_CMA302 276 277- Motherboard Options: (if CONFIG_CMA101 or CONFIG_CMA102 are defined) 278 Define one or more of 279 CONFIG_LCD_HEARTBEAT - update a character position on 280 the lcd display every second with 281 a "rotator" |\-/|\-/ 282 283- Board flavour: (if CONFIG_MPC8260ADS is defined) 284 CONFIG_ADSTYPE 285 Possible values are: 286 CFG_8260ADS - original MPC8260ADS 287 CFG_8266ADS - MPC8266ADS 288 CFG_PQ2FADS - PQ2FADS-ZU or PQ2FADS-VR 289 CFG_8272ADS - MPC8272ADS 290 291- MPC824X Family Member (if CONFIG_MPC824X is defined) 292 Define exactly one of 293 CONFIG_MPC8240, CONFIG_MPC8245 294 295- 8xx CPU Options: (if using an MPC8xx cpu) 296 CONFIG_8xx_GCLK_FREQ - deprecated: CPU clock if 297 get_gclk_freq() cannot work 298 e.g. if there is no 32KHz 299 reference PIT/RTC clock 300 CONFIG_8xx_OSCLK - PLL input clock (either EXTCLK 301 or XTAL/EXTAL) 302 303- 859/866/885 CPU options: (if using a MPC859 or MPC866 or MPC885 CPU): 304 CFG_8xx_CPUCLK_MIN 305 CFG_8xx_CPUCLK_MAX 306 CONFIG_8xx_CPUCLK_DEFAULT 307 See doc/README.MPC866 308 309 CFG_MEASURE_CPUCLK 310 311 Define this to measure the actual CPU clock instead 312 of relying on the correctness of the configured 313 values. Mostly useful for board bringup to make sure 314 the PLL is locked at the intended frequency. Note 315 that this requires a (stable) reference clock (32 kHz 316 RTC clock or CFG_8XX_XIN) 317 318- Intel Monahans options: 319 CFG_MONAHANS_RUN_MODE_OSC_RATIO 320 321 Defines the Monahans run mode to oscillator 322 ratio. Valid values are 8, 16, 24, 31. The core 323 frequency is this value multiplied by 13 MHz. 324 325 CFG_MONAHANS_TURBO_RUN_MODE_RATIO 326 327 Defines the Monahans turbo mode to oscillator 328 ratio. Valid values are 1 (default if undefined) and 329 2. The core frequency as calculated above is multiplied 330 by this value. 331 332- Linux Kernel Interface: 333 CONFIG_CLOCKS_IN_MHZ 334 335 U-Boot stores all clock information in Hz 336 internally. For binary compatibility with older Linux 337 kernels (which expect the clocks passed in the 338 bd_info data to be in MHz) the environment variable 339 "clocks_in_mhz" can be defined so that U-Boot 340 converts clock data to MHZ before passing it to the 341 Linux kernel. 342 When CONFIG_CLOCKS_IN_MHZ is defined, a definition of 343 "clocks_in_mhz=1" is automatically included in the 344 default environment. 345 346 CONFIG_MEMSIZE_IN_BYTES [relevant for MIPS only] 347 348 When transfering memsize parameter to linux, some versions 349 expect it to be in bytes, others in MB. 350 Define CONFIG_MEMSIZE_IN_BYTES to make it in bytes. 351 352 CONFIG_OF_LIBFDT / CONFIG_OF_FLAT_TREE 353 354 New kernel versions are expecting firmware settings to be 355 passed using flattened device trees (based on open firmware 356 concepts). 357 358 CONFIG_OF_LIBFDT 359 * New libfdt-based support 360 * Adds the "fdt" command 361 * The bootm command automatically updates the fdt 362 363 CONFIG_OF_FLAT_TREE 364 * Deprecated, see CONFIG_OF_LIBFDT 365 * Original ft_build.c-based support 366 * Automatically modifies the dft as part of the bootm command 367 * The environment variable "disable_of", when set, 368 disables this functionality. 369 370 OF_CPU - The proper name of the cpus node. 371 OF_SOC - The proper name of the soc node. 372 OF_TBCLK - The timebase frequency. 373 OF_STDOUT_PATH - The path to the console device 374 375 boards with QUICC Engines require OF_QE to set UCC mac addresses 376 377 CONFIG_OF_BOARD_SETUP 378 379 Board code has addition modification that it wants to make 380 to the flat device tree before handing it off to the kernel 381 382 CONFIG_OF_BOOT_CPU 383 384 This define fills in the correct boot cpu in the boot 385 param header, the default value is zero if undefined. 386 387- Serial Ports: 388 CFG_PL010_SERIAL 389 390 Define this if you want support for Amba PrimeCell PL010 UARTs. 391 392 CFG_PL011_SERIAL 393 394 Define this if you want support for Amba PrimeCell PL011 UARTs. 395 396 CONFIG_PL011_CLOCK 397 398 If you have Amba PrimeCell PL011 UARTs, set this variable to 399 the clock speed of the UARTs. 400 401 CONFIG_PL01x_PORTS 402 403 If you have Amba PrimeCell PL010 or PL011 UARTs on your board, 404 define this to a list of base addresses for each (supported) 405 port. See e.g. include/configs/versatile.h 406 407 408- Console Interface: 409 Depending on board, define exactly one serial port 410 (like CONFIG_8xx_CONS_SMC1, CONFIG_8xx_CONS_SMC2, 411 CONFIG_8xx_CONS_SCC1, ...), or switch off the serial 412 console by defining CONFIG_8xx_CONS_NONE 413 414 Note: if CONFIG_8xx_CONS_NONE is defined, the serial 415 port routines must be defined elsewhere 416 (i.e. serial_init(), serial_getc(), ...) 417 418 CONFIG_CFB_CONSOLE 419 Enables console device for a color framebuffer. Needs following 420 defines (cf. smiLynxEM, i8042, board/eltec/bab7xx) 421 VIDEO_FB_LITTLE_ENDIAN graphic memory organisation 422 (default big endian) 423 VIDEO_HW_RECTFILL graphic chip supports 424 rectangle fill 425 (cf. smiLynxEM) 426 VIDEO_HW_BITBLT graphic chip supports 427 bit-blit (cf. smiLynxEM) 428 VIDEO_VISIBLE_COLS visible pixel columns 429 (cols=pitch) 430 VIDEO_VISIBLE_ROWS visible pixel rows 431 VIDEO_PIXEL_SIZE bytes per pixel 432 VIDEO_DATA_FORMAT graphic data format 433 (0-5, cf. cfb_console.c) 434 VIDEO_FB_ADRS framebuffer address 435 VIDEO_KBD_INIT_FCT keyboard int fct 436 (i.e. i8042_kbd_init()) 437 VIDEO_TSTC_FCT test char fct 438 (i.e. i8042_tstc) 439 VIDEO_GETC_FCT get char fct 440 (i.e. i8042_getc) 441 CONFIG_CONSOLE_CURSOR cursor drawing on/off 442 (requires blink timer 443 cf. i8042.c) 444 CFG_CONSOLE_BLINK_COUNT blink interval (cf. i8042.c) 445 CONFIG_CONSOLE_TIME display time/date info in 446 upper right corner 447 (requires CONFIG_CMD_DATE) 448 CONFIG_VIDEO_LOGO display Linux logo in 449 upper left corner 450 CONFIG_VIDEO_BMP_LOGO use bmp_logo.h instead of 451 linux_logo.h for logo. 452 Requires CONFIG_VIDEO_LOGO 453 CONFIG_CONSOLE_EXTRA_INFO 454 addional board info beside 455 the logo 456 457 When CONFIG_CFB_CONSOLE is defined, video console is 458 default i/o. Serial console can be forced with 459 environment 'console=serial'. 460 461 When CONFIG_SILENT_CONSOLE is defined, all console 462 messages (by U-Boot and Linux!) can be silenced with 463 the "silent" environment variable. See 464 doc/README.silent for more information. 465 466- Console Baudrate: 467 CONFIG_BAUDRATE - in bps 468 Select one of the baudrates listed in 469 CFG_BAUDRATE_TABLE, see below. 470 CFG_BRGCLK_PRESCALE, baudrate prescale 471 472- Interrupt driven serial port input: 473 CONFIG_SERIAL_SOFTWARE_FIFO 474 475 PPC405GP only. 476 Use an interrupt handler for receiving data on the 477 serial port. It also enables using hardware handshake 478 (RTS/CTS) and UART's built-in FIFO. Set the number of 479 bytes the interrupt driven input buffer should have. 480 481 Leave undefined to disable this feature, including 482 disable the buffer and hardware handshake. 483 484- Console UART Number: 485 CONFIG_UART1_CONSOLE 486 487 AMCC PPC4xx only. 488 If defined internal UART1 (and not UART0) is used 489 as default U-Boot console. 490 491- Boot Delay: CONFIG_BOOTDELAY - in seconds 492 Delay before automatically booting the default image; 493 set to -1 to disable autoboot. 494 495 See doc/README.autoboot for these options that 496 work with CONFIG_BOOTDELAY. None are required. 497 CONFIG_BOOT_RETRY_TIME 498 CONFIG_BOOT_RETRY_MIN 499 CONFIG_AUTOBOOT_KEYED 500 CONFIG_AUTOBOOT_PROMPT 501 CONFIG_AUTOBOOT_DELAY_STR 502 CONFIG_AUTOBOOT_STOP_STR 503 CONFIG_AUTOBOOT_DELAY_STR2 504 CONFIG_AUTOBOOT_STOP_STR2 505 CONFIG_ZERO_BOOTDELAY_CHECK 506 CONFIG_RESET_TO_RETRY 507 508- Autoboot Command: 509 CONFIG_BOOTCOMMAND 510 Only needed when CONFIG_BOOTDELAY is enabled; 511 define a command string that is automatically executed 512 when no character is read on the console interface 513 within "Boot Delay" after reset. 514 515 CONFIG_BOOTARGS 516 This can be used to pass arguments to the bootm 517 command. The value of CONFIG_BOOTARGS goes into the 518 environment value "bootargs". 519 520 CONFIG_RAMBOOT and CONFIG_NFSBOOT 521 The value of these goes into the environment as 522 "ramboot" and "nfsboot" respectively, and can be used 523 as a convenience, when switching between booting from 524 ram and nfs. 525 526- Pre-Boot Commands: 527 CONFIG_PREBOOT 528 529 When this option is #defined, the existence of the 530 environment variable "preboot" will be checked 531 immediately before starting the CONFIG_BOOTDELAY 532 countdown and/or running the auto-boot command resp. 533 entering interactive mode. 534 535 This feature is especially useful when "preboot" is 536 automatically generated or modified. For an example 537 see the LWMON board specific code: here "preboot" is 538 modified when the user holds down a certain 539 combination of keys on the (special) keyboard when 540 booting the systems 541 542- Serial Download Echo Mode: 543 CONFIG_LOADS_ECHO 544 If defined to 1, all characters received during a 545 serial download (using the "loads" command) are 546 echoed back. This might be needed by some terminal 547 emulations (like "cu"), but may as well just take 548 time on others. This setting #define's the initial 549 value of the "loads_echo" environment variable. 550 551- Kgdb Serial Baudrate: (if CONFIG_CMD_KGDB is defined) 552 CONFIG_KGDB_BAUDRATE 553 Select one of the baudrates listed in 554 CFG_BAUDRATE_TABLE, see below. 555 556- Monitor Functions: 557 Monitor commands can be included or excluded 558 from the build by using the #include files 559 "config_cmd_all.h" and #undef'ing unwanted 560 commands, or using "config_cmd_default.h" 561 and augmenting with additional #define's 562 for wanted commands. 563 564 The default command configuration includes all commands 565 except those marked below with a "*". 566 567 CONFIG_CMD_ASKENV * ask for env variable 568 CONFIG_CMD_AUTOSCRIPT Autoscript Support 569 CONFIG_CMD_BDI bdinfo 570 CONFIG_CMD_BEDBUG * Include BedBug Debugger 571 CONFIG_CMD_BMP * BMP support 572 CONFIG_CMD_BSP * Board specific commands 573 CONFIG_CMD_BOOTD bootd 574 CONFIG_CMD_CACHE * icache, dcache 575 CONFIG_CMD_CONSOLE coninfo 576 CONFIG_CMD_DATE * support for RTC, date/time... 577 CONFIG_CMD_DHCP * DHCP support 578 CONFIG_CMD_DIAG * Diagnostics 579 CONFIG_CMD_DOC * Disk-On-Chip Support 580 CONFIG_CMD_DTT * Digital Therm and Thermostat 581 CONFIG_CMD_ECHO echo arguments 582 CONFIG_CMD_EEPROM * EEPROM read/write support 583 CONFIG_CMD_ELF * bootelf, bootvx 584 CONFIG_CMD_ENV saveenv 585 CONFIG_CMD_FDC * Floppy Disk Support 586 CONFIG_CMD_FAT * FAT partition support 587 CONFIG_CMD_FDOS * Dos diskette Support 588 CONFIG_CMD_FLASH flinfo, erase, protect 589 CONFIG_CMD_FPGA FPGA device initialization support 590 CONFIG_CMD_HWFLOW * RTS/CTS hw flow control 591 CONFIG_CMD_I2C * I2C serial bus support 592 CONFIG_CMD_IDE * IDE harddisk support 593 CONFIG_CMD_IMI iminfo 594 CONFIG_CMD_IMLS List all found images 595 CONFIG_CMD_IMMAP * IMMR dump support 596 CONFIG_CMD_IRQ * irqinfo 597 CONFIG_CMD_ITEST Integer/string test of 2 values 598 CONFIG_CMD_JFFS2 * JFFS2 Support 599 CONFIG_CMD_KGDB * kgdb 600 CONFIG_CMD_LOADB loadb 601 CONFIG_CMD_LOADS loads 602 CONFIG_CMD_MEMORY md, mm, nm, mw, cp, cmp, crc, base, 603 loop, loopw, mtest 604 CONFIG_CMD_MISC Misc functions like sleep etc 605 CONFIG_CMD_MMC * MMC memory mapped support 606 CONFIG_CMD_MII * MII utility commands 607 CONFIG_CMD_NAND * NAND support 608 CONFIG_CMD_NET bootp, tftpboot, rarpboot 609 CONFIG_CMD_PCI * pciinfo 610 CONFIG_CMD_PCMCIA * PCMCIA support 611 CONFIG_CMD_PING * send ICMP ECHO_REQUEST to network 612 host 613 CONFIG_CMD_PORTIO * Port I/O 614 CONFIG_CMD_REGINFO * Register dump 615 CONFIG_CMD_RUN run command in env variable 616 CONFIG_CMD_SAVES * save S record dump 617 CONFIG_CMD_SCSI * SCSI Support 618 CONFIG_CMD_SDRAM * print SDRAM configuration information 619 (requires CONFIG_CMD_I2C) 620 CONFIG_CMD_SETGETDCR Support for DCR Register access 621 (4xx only) 622 CONFIG_CMD_SPI * SPI serial bus support 623 CONFIG_CMD_USB * USB support 624 CONFIG_CMD_VFD * VFD support (TRAB) 625 CONFIG_CMD_BSP * Board SPecific functions 626 CONFIG_CMD_CDP * Cisco Discover Protocol support 627 CONFIG_CMD_FSL * Microblaze FSL support 628 629 630 EXAMPLE: If you want all functions except of network 631 support you can write: 632 633 #include "config_cmd_all.h" 634 #undef CONFIG_CMD_NET 635 636 Other Commands: 637 fdt (flattened device tree) command: CONFIG_OF_LIBFDT 638 639 Note: Don't enable the "icache" and "dcache" commands 640 (configuration option CONFIG_CMD_CACHE) unless you know 641 what you (and your U-Boot users) are doing. Data 642 cache cannot be enabled on systems like the 8xx or 643 8260 (where accesses to the IMMR region must be 644 uncached), and it cannot be disabled on all other 645 systems where we (mis-) use the data cache to hold an 646 initial stack and some data. 647 648 649 XXX - this list needs to get updated! 650 651- Watchdog: 652 CONFIG_WATCHDOG 653 If this variable is defined, it enables watchdog 654 support. There must be support in the platform specific 655 code for a watchdog. For the 8xx and 8260 CPUs, the 656 SIU Watchdog feature is enabled in the SYPCR 657 register. 658 659- U-Boot Version: 660 CONFIG_VERSION_VARIABLE 661 If this variable is defined, an environment variable 662 named "ver" is created by U-Boot showing the U-Boot 663 version as printed by the "version" command. 664 This variable is readonly. 665 666- Real-Time Clock: 667 668 When CONFIG_CMD_DATE is selected, the type of the RTC 669 has to be selected, too. Define exactly one of the 670 following options: 671 672 CONFIG_RTC_MPC8xx - use internal RTC of MPC8xx 673 CONFIG_RTC_PCF8563 - use Philips PCF8563 RTC 674 CONFIG_RTC_MC146818 - use MC146818 RTC 675 CONFIG_RTC_DS1307 - use Maxim, Inc. DS1307 RTC 676 CONFIG_RTC_DS1337 - use Maxim, Inc. DS1337 RTC 677 CONFIG_RTC_DS1338 - use Maxim, Inc. DS1338 RTC 678 CONFIG_RTC_DS164x - use Dallas DS164x RTC 679 CONFIG_RTC_ISL1208 - use Intersil ISL1208 RTC 680 CONFIG_RTC_MAX6900 - use Maxim, Inc. MAX6900 RTC 681 CFG_RTC_DS1337_NOOSC - Turn off the OSC output for DS1337 682 683 Note that if the RTC uses I2C, then the I2C interface 684 must also be configured. See I2C Support, below. 685 686- Timestamp Support: 687 688 When CONFIG_TIMESTAMP is selected, the timestamp 689 (date and time) of an image is printed by image 690 commands like bootm or iminfo. This option is 691 automatically enabled when you select CONFIG_CMD_DATE . 692 693- Partition Support: 694 CONFIG_MAC_PARTITION and/or CONFIG_DOS_PARTITION 695 and/or CONFIG_ISO_PARTITION 696 697 If IDE or SCSI support is enabled (CONFIG_CMD_IDE or 698 CONFIG_CMD_SCSI) you must configure support for at 699 least one partition type as well. 700 701- IDE Reset method: 702 CONFIG_IDE_RESET_ROUTINE - this is defined in several 703 board configurations files but used nowhere! 704 705 CONFIG_IDE_RESET - is this is defined, IDE Reset will 706 be performed by calling the function 707 ide_set_reset(int reset) 708 which has to be defined in a board specific file 709 710- ATAPI Support: 711 CONFIG_ATAPI 712 713 Set this to enable ATAPI support. 714 715- LBA48 Support 716 CONFIG_LBA48 717 718 Set this to enable support for disks larger than 137GB 719 Also look at CFG_64BIT_LBA ,CFG_64BIT_VSPRINTF and CFG_64BIT_STRTOUL 720 Whithout these , LBA48 support uses 32bit variables and will 'only' 721 support disks up to 2.1TB. 722 723 CFG_64BIT_LBA: 724 When enabled, makes the IDE subsystem use 64bit sector addresses. 725 Default is 32bit. 726 727- SCSI Support: 728 At the moment only there is only support for the 729 SYM53C8XX SCSI controller; define 730 CONFIG_SCSI_SYM53C8XX to enable it. 731 732 CFG_SCSI_MAX_LUN [8], CFG_SCSI_MAX_SCSI_ID [7] and 733 CFG_SCSI_MAX_DEVICE [CFG_SCSI_MAX_SCSI_ID * 734 CFG_SCSI_MAX_LUN] can be adjusted to define the 735 maximum numbers of LUNs, SCSI ID's and target 736 devices. 737 CFG_SCSI_SYM53C8XX_CCF to fix clock timing (80Mhz) 738 739- NETWORK Support (PCI): 740 CONFIG_E1000 741 Support for Intel 8254x gigabit chips. 742 743 CONFIG_E1000_FALLBACK_MAC 744 default MAC for empty eeprom after production. 745 746 CONFIG_EEPRO100 747 Support for Intel 82557/82559/82559ER chips. 748 Optional CONFIG_EEPRO100_SROM_WRITE enables eeprom 749 write routine for first time initialisation. 750 751 CONFIG_TULIP 752 Support for Digital 2114x chips. 753 Optional CONFIG_TULIP_SELECT_MEDIA for board specific 754 modem chip initialisation (KS8761/QS6611). 755 756 CONFIG_NATSEMI 757 Support for National dp83815 chips. 758 759 CONFIG_NS8382X 760 Support for National dp8382[01] gigabit chips. 761 762- NETWORK Support (other): 763 764 CONFIG_DRIVER_LAN91C96 765 Support for SMSC's LAN91C96 chips. 766 767 CONFIG_LAN91C96_BASE 768 Define this to hold the physical address 769 of the LAN91C96's I/O space 770 771 CONFIG_LAN91C96_USE_32_BIT 772 Define this to enable 32 bit addressing 773 774 CONFIG_DRIVER_SMC91111 775 Support for SMSC's LAN91C111 chip 776 777 CONFIG_SMC91111_BASE 778 Define this to hold the physical address 779 of the device (I/O space) 780 781 CONFIG_SMC_USE_32_BIT 782 Define this if data bus is 32 bits 783 784 CONFIG_SMC_USE_IOFUNCS 785 Define this to use i/o functions instead of macros 786 (some hardware wont work with macros) 787 788- USB Support: 789 At the moment only the UHCI host controller is 790 supported (PIP405, MIP405, MPC5200); define 791 CONFIG_USB_UHCI to enable it. 792 define CONFIG_USB_KEYBOARD to enable the USB Keyboard 793 and define CONFIG_USB_STORAGE to enable the USB 794 storage devices. 795 Note: 796 Supported are USB Keyboards and USB Floppy drives 797 (TEAC FD-05PUB). 798 MPC5200 USB requires additional defines: 799 CONFIG_USB_CLOCK 800 for 528 MHz Clock: 0x0001bbbb 801 CONFIG_USB_CONFIG 802 for differential drivers: 0x00001000 803 for single ended drivers: 0x00005000 804 CFG_USB_EVENT_POLL 805 May be defined to allow interrupt polling 806 instead of using asynchronous interrupts 807 808- USB Device: 809 Define the below if you wish to use the USB console. 810 Once firmware is rebuilt from a serial console issue the 811 command "setenv stdin usbtty; setenv stdout usbtty" and 812 attach your usb cable. The Unix command "dmesg" should print 813 it has found a new device. The environment variable usbtty 814 can be set to gserial or cdc_acm to enable your device to 815 appear to a USB host as a Linux gserial device or a 816 Common Device Class Abstract Control Model serial device. 817 If you select usbtty = gserial you should be able to enumerate 818 a Linux host by 819 # modprobe usbserial vendor=0xVendorID product=0xProductID 820 else if using cdc_acm, simply setting the environment 821 variable usbtty to be cdc_acm should suffice. The following 822 might be defined in YourBoardName.h 823 824 CONFIG_USB_DEVICE 825 Define this to build a UDC device 826 827 CONFIG_USB_TTY 828 Define this to have a tty type of device available to 829 talk to the UDC device 830 831 CFG_CONSOLE_IS_IN_ENV 832 Define this if you want stdin, stdout &/or stderr to 833 be set to usbtty. 834 835 mpc8xx: 836 CFG_USB_EXTC_CLK 0xBLAH 837 Derive USB clock from external clock "blah" 838 - CFG_USB_EXTC_CLK 0x02 839 840 CFG_USB_BRG_CLK 0xBLAH 841 Derive USB clock from brgclk 842 - CFG_USB_BRG_CLK 0x04 843 844 If you have a USB-IF assigned VendorID then you may wish to 845 define your own vendor specific values either in BoardName.h 846 or directly in usbd_vendor_info.h. If you don't define 847 CONFIG_USBD_MANUFACTURER, CONFIG_USBD_PRODUCT_NAME, 848 CONFIG_USBD_VENDORID and CONFIG_USBD_PRODUCTID, then U-Boot 849 should pretend to be a Linux device to it's target host. 850 851 CONFIG_USBD_MANUFACTURER 852 Define this string as the name of your company for 853 - CONFIG_USBD_MANUFACTURER "my company" 854 855 CONFIG_USBD_PRODUCT_NAME 856 Define this string as the name of your product 857 - CONFIG_USBD_PRODUCT_NAME "acme usb device" 858 859 CONFIG_USBD_VENDORID 860 Define this as your assigned Vendor ID from the USB 861 Implementors Forum. This *must* be a genuine Vendor ID 862 to avoid polluting the USB namespace. 863 - CONFIG_USBD_VENDORID 0xFFFF 864 865 CONFIG_USBD_PRODUCTID 866 Define this as the unique Product ID 867 for your device 868 - CONFIG_USBD_PRODUCTID 0xFFFF 869 870 871- MMC Support: 872 The MMC controller on the Intel PXA is supported. To 873 enable this define CONFIG_MMC. The MMC can be 874 accessed from the boot prompt by mapping the device 875 to physical memory similar to flash. Command line is 876 enabled with CONFIG_CMD_MMC. The MMC driver also works with 877 the FAT fs. This is enabled with CONFIG_CMD_FAT. 878 879- Journaling Flash filesystem support: 880 CONFIG_JFFS2_NAND, CONFIG_JFFS2_NAND_OFF, CONFIG_JFFS2_NAND_SIZE, 881 CONFIG_JFFS2_NAND_DEV 882 Define these for a default partition on a NAND device 883 884 CFG_JFFS2_FIRST_SECTOR, 885 CFG_JFFS2_FIRST_BANK, CFG_JFFS2_NUM_BANKS 886 Define these for a default partition on a NOR device 887 888 CFG_JFFS_CUSTOM_PART 889 Define this to create an own partition. You have to provide a 890 function struct part_info* jffs2_part_info(int part_num) 891 892 If you define only one JFFS2 partition you may also want to 893 #define CFG_JFFS_SINGLE_PART 1 894 to disable the command chpart. This is the default when you 895 have not defined a custom partition 896 897- Keyboard Support: 898 CONFIG_ISA_KEYBOARD 899 900 Define this to enable standard (PC-Style) keyboard 901 support 902 903 CONFIG_I8042_KBD 904 Standard PC keyboard driver with US (is default) and 905 GERMAN key layout (switch via environment 'keymap=de') support. 906 Export function i8042_kbd_init, i8042_tstc and i8042_getc 907 for cfb_console. Supports cursor blinking. 908 909- Video support: 910 CONFIG_VIDEO 911 912 Define this to enable video support (for output to 913 video). 914 915 CONFIG_VIDEO_CT69000 916 917 Enable Chips & Technologies 69000 Video chip 918 919 CONFIG_VIDEO_SMI_LYNXEM 920 Enable Silicon Motion SMI 712/710/810 Video chip. The 921 video output is selected via environment 'videoout' 922 (1 = LCD and 2 = CRT). If videoout is undefined, CRT is 923 assumed. 924 925 For the CT69000 and SMI_LYNXEM drivers, videomode is 926 selected via environment 'videomode'. Two diferent ways 927 are possible: 928 - "videomode=num" 'num' is a standard LiLo mode numbers. 929 Following standard modes are supported (* is default): 930 931 Colors 640x480 800x600 1024x768 1152x864 1280x1024 932 -------------+--------------------------------------------- 933 8 bits | 0x301* 0x303 0x305 0x161 0x307 934 15 bits | 0x310 0x313 0x316 0x162 0x319 935 16 bits | 0x311 0x314 0x317 0x163 0x31A 936 24 bits | 0x312 0x315 0x318 ? 0x31B 937 -------------+--------------------------------------------- 938 (i.e. setenv videomode 317; saveenv; reset;) 939 940 - "videomode=bootargs" all the video parameters are parsed 941 from the bootargs. (See drivers/video/videomodes.c) 942 943 944 CONFIG_VIDEO_SED13806 945 Enable Epson SED13806 driver. This driver supports 8bpp 946 and 16bpp modes defined by CONFIG_VIDEO_SED13806_8BPP 947 or CONFIG_VIDEO_SED13806_16BPP 948 949- Keyboard Support: 950 CONFIG_KEYBOARD 951 952 Define this to enable a custom keyboard support. 953 This simply calls drv_keyboard_init() which must be 954 defined in your board-specific files. 955 The only board using this so far is RBC823. 956 957- LCD Support: CONFIG_LCD 958 959 Define this to enable LCD support (for output to LCD 960 display); also select one of the supported displays 961 by defining one of these: 962 963 CONFIG_NEC_NL6448AC33: 964 965 NEC NL6448AC33-18. Active, color, single scan. 966 967 CONFIG_NEC_NL6448BC20 968 969 NEC NL6448BC20-08. 6.5", 640x480. 970 Active, color, single scan. 971 972 CONFIG_NEC_NL6448BC33_54 973 974 NEC NL6448BC33-54. 10.4", 640x480. 975 Active, color, single scan. 976 977 CONFIG_SHARP_16x9 978 979 Sharp 320x240. Active, color, single scan. 980 It isn't 16x9, and I am not sure what it is. 981 982 CONFIG_SHARP_LQ64D341 983 984 Sharp LQ64D341 display, 640x480. 985 Active, color, single scan. 986 987 CONFIG_HLD1045 988 989 HLD1045 display, 640x480. 990 Active, color, single scan. 991 992 CONFIG_OPTREX_BW 993 994 Optrex CBL50840-2 NF-FW 99 22 M5 995 or 996 Hitachi LMG6912RPFC-00T 997 or 998 Hitachi SP14Q002 999 1000 320x240. Black & white. 1001 1002 Normally display is black on white background; define 1003 CFG_WHITE_ON_BLACK to get it inverted. 1004 1005- Splash Screen Support: CONFIG_SPLASH_SCREEN 1006 1007 If this option is set, the environment is checked for 1008 a variable "splashimage". If found, the usual display 1009 of logo, copyright and system information on the LCD 1010 is suppressed and the BMP image at the address 1011 specified in "splashimage" is loaded instead. The 1012 console is redirected to the "nulldev", too. This 1013 allows for a "silent" boot where a splash screen is 1014 loaded very quickly after power-on. 1015 1016- Gzip compressed BMP image support: CONFIG_VIDEO_BMP_GZIP 1017 1018 If this option is set, additionally to standard BMP 1019 images, gzipped BMP images can be displayed via the 1020 splashscreen support or the bmp command. 1021 1022- Compression support: 1023 CONFIG_BZIP2 1024 1025 If this option is set, support for bzip2 compressed 1026 images is included. If not, only uncompressed and gzip 1027 compressed images are supported. 1028 1029 NOTE: the bzip2 algorithm requires a lot of RAM, so 1030 the malloc area (as defined by CFG_MALLOC_LEN) should 1031 be at least 4MB. 1032 1033- MII/PHY support: 1034 CONFIG_PHY_ADDR 1035 1036 The address of PHY on MII bus. 1037 1038 CONFIG_PHY_CLOCK_FREQ (ppc4xx) 1039 1040 The clock frequency of the MII bus 1041 1042 CONFIG_PHY_GIGE 1043 1044 If this option is set, support for speed/duplex 1045 detection of Gigabit PHY is included. 1046 1047 CONFIG_PHY_RESET_DELAY 1048 1049 Some PHY like Intel LXT971A need extra delay after 1050 reset before any MII register access is possible. 1051 For such PHY, set this option to the usec delay 1052 required. (minimum 300usec for LXT971A) 1053 1054 CONFIG_PHY_CMD_DELAY (ppc4xx) 1055 1056 Some PHY like Intel LXT971A need extra delay after 1057 command issued before MII status register can be read 1058 1059- Ethernet address: 1060 CONFIG_ETHADDR 1061 CONFIG_ETH2ADDR 1062 CONFIG_ETH3ADDR 1063 1064 Define a default value for ethernet address to use 1065 for the respective ethernet interface, in case this 1066 is not determined automatically. 1067 1068- IP address: 1069 CONFIG_IPADDR 1070 1071 Define a default value for the IP address to use for 1072 the default ethernet interface, in case this is not 1073 determined through e.g. bootp. 1074 1075- Server IP address: 1076 CONFIG_SERVERIP 1077 1078 Defines a default value for theIP address of a TFTP 1079 server to contact when using the "tftboot" command. 1080 1081- Multicast TFTP Mode: 1082 CONFIG_MCAST_TFTP 1083 1084 Defines whether you want to support multicast TFTP as per 1085 rfc-2090; for example to work with atftp. Lets lots of targets 1086 tftp down the same boot image concurrently. Note: the ethernet 1087 driver in use must provide a function: mcast() to join/leave a 1088 multicast group. 1089 1090 CONFIG_BOOTP_RANDOM_DELAY 1091- BOOTP Recovery Mode: 1092 CONFIG_BOOTP_RANDOM_DELAY 1093 1094 If you have many targets in a network that try to 1095 boot using BOOTP, you may want to avoid that all 1096 systems send out BOOTP requests at precisely the same 1097 moment (which would happen for instance at recovery 1098 from a power failure, when all systems will try to 1099 boot, thus flooding the BOOTP server. Defining 1100 CONFIG_BOOTP_RANDOM_DELAY causes a random delay to be 1101 inserted before sending out BOOTP requests. The 1102 following delays are inserted then: 1103 1104 1st BOOTP request: delay 0 ... 1 sec 1105 2nd BOOTP request: delay 0 ... 2 sec 1106 3rd BOOTP request: delay 0 ... 4 sec 1107 4th and following 1108 BOOTP requests: delay 0 ... 8 sec 1109 1110- DHCP Advanced Options: 1111 You can fine tune the DHCP functionality by defining 1112 CONFIG_BOOTP_* symbols: 1113 1114 CONFIG_BOOTP_SUBNETMASK 1115 CONFIG_BOOTP_GATEWAY 1116 CONFIG_BOOTP_HOSTNAME 1117 CONFIG_BOOTP_NISDOMAIN 1118 CONFIG_BOOTP_BOOTPATH 1119 CONFIG_BOOTP_BOOTFILESIZE 1120 CONFIG_BOOTP_DNS 1121 CONFIG_BOOTP_DNS2 1122 CONFIG_BOOTP_SEND_HOSTNAME 1123 CONFIG_BOOTP_NTPSERVER 1124 CONFIG_BOOTP_TIMEOFFSET 1125 CONFIG_BOOTP_VENDOREX 1126 1127 CONFIG_BOOTP_SERVERIP - TFTP server will be the serverip 1128 environment variable, not the BOOTP server. 1129 1130 CONFIG_BOOTP_DNS2 - If a DHCP client requests the DNS 1131 serverip from a DHCP server, it is possible that more 1132 than one DNS serverip is offered to the client. 1133 If CONFIG_BOOTP_DNS2 is enabled, the secondary DNS 1134 serverip will be stored in the additional environment 1135 variable "dnsip2". The first DNS serverip is always 1136 stored in the variable "dnsip", when CONFIG_BOOTP_DNS 1137 is defined. 1138 1139 CONFIG_BOOTP_SEND_HOSTNAME - Some DHCP servers are capable 1140 to do a dynamic update of a DNS server. To do this, they 1141 need the hostname of the DHCP requester. 1142 If CONFIG_BOOTP_SEND_HOSTNAME is defined, the content 1143 of the "hostname" environment variable is passed as 1144 option 12 to the DHCP server. 1145 1146 CONFIG_BOOTP_DHCP_REQUEST_DELAY 1147 1148 A 32bit value in microseconds for a delay between 1149 receiving a "DHCP Offer" and sending the "DHCP Request". 1150 This fixes a problem with certain DHCP servers that don't 1151 respond 100% of the time to a "DHCP request". E.g. On an 1152 AT91RM9200 processor running at 180MHz, this delay needed 1153 to be *at least* 15,000 usec before a Windows Server 2003 1154 DHCP server would reply 100% of the time. I recommend at 1155 least 50,000 usec to be safe. The alternative is to hope 1156 that one of the retries will be successful but note that 1157 the DHCP timeout and retry process takes a longer than 1158 this delay. 1159 1160 - CDP Options: 1161 CONFIG_CDP_DEVICE_ID 1162 1163 The device id used in CDP trigger frames. 1164 1165 CONFIG_CDP_DEVICE_ID_PREFIX 1166 1167 A two character string which is prefixed to the MAC address 1168 of the device. 1169 1170 CONFIG_CDP_PORT_ID 1171 1172 A printf format string which contains the ascii name of 1173 the port. Normally is set to "eth%d" which sets 1174 eth0 for the first ethernet, eth1 for the second etc. 1175 1176 CONFIG_CDP_CAPABILITIES 1177 1178 A 32bit integer which indicates the device capabilities; 1179 0x00000010 for a normal host which does not forwards. 1180 1181 CONFIG_CDP_VERSION 1182 1183 An ascii string containing the version of the software. 1184 1185 CONFIG_CDP_PLATFORM 1186 1187 An ascii string containing the name of the platform. 1188 1189 CONFIG_CDP_TRIGGER 1190 1191 A 32bit integer sent on the trigger. 1192 1193 CONFIG_CDP_POWER_CONSUMPTION 1194 1195 A 16bit integer containing the power consumption of the 1196 device in .1 of milliwatts. 1197 1198 CONFIG_CDP_APPLIANCE_VLAN_TYPE 1199 1200 A byte containing the id of the VLAN. 1201 1202- Status LED: CONFIG_STATUS_LED 1203 1204 Several configurations allow to display the current 1205 status using a LED. For instance, the LED will blink 1206 fast while running U-Boot code, stop blinking as 1207 soon as a reply to a BOOTP request was received, and 1208 start blinking slow once the Linux kernel is running 1209 (supported by a status LED driver in the Linux 1210 kernel). Defining CONFIG_STATUS_LED enables this 1211 feature in U-Boot. 1212 1213- CAN Support: CONFIG_CAN_DRIVER 1214 1215 Defining CONFIG_CAN_DRIVER enables CAN driver support 1216 on those systems that support this (optional) 1217 feature, like the TQM8xxL modules. 1218 1219- I2C Support: CONFIG_HARD_I2C | CONFIG_SOFT_I2C 1220 1221 These enable I2C serial bus commands. Defining either of 1222 (but not both of) CONFIG_HARD_I2C or CONFIG_SOFT_I2C will 1223 include the appropriate I2C driver for the selected cpu. 1224 1225 This will allow you to use i2c commands at the u-boot 1226 command line (as long as you set CONFIG_CMD_I2C in 1227 CONFIG_COMMANDS) and communicate with i2c based realtime 1228 clock chips. See common/cmd_i2c.c for a description of the 1229 command line interface. 1230 1231 CONFIG_I2C_CMD_TREE is a recommended option that places 1232 all I2C commands under a single 'i2c' root command. The 1233 older 'imm', 'imd', 'iprobe' etc. commands are considered 1234 deprecated and may disappear in the future. 1235 1236 CONFIG_HARD_I2C selects a hardware I2C controller. 1237 1238 CONFIG_SOFT_I2C configures u-boot to use a software (aka 1239 bit-banging) driver instead of CPM or similar hardware 1240 support for I2C. 1241 1242 There are several other quantities that must also be 1243 defined when you define CONFIG_HARD_I2C or CONFIG_SOFT_I2C. 1244 1245 In both cases you will need to define CFG_I2C_SPEED 1246 to be the frequency (in Hz) at which you wish your i2c bus 1247 to run and CFG_I2C_SLAVE to be the address of this node (ie 1248 the cpu's i2c node address). 1249 1250 Now, the u-boot i2c code for the mpc8xx (cpu/mpc8xx/i2c.c) 1251 sets the cpu up as a master node and so its address should 1252 therefore be cleared to 0 (See, eg, MPC823e User's Manual 1253 p.16-473). So, set CFG_I2C_SLAVE to 0. 1254 1255 That's all that's required for CONFIG_HARD_I2C. 1256 1257 If you use the software i2c interface (CONFIG_SOFT_I2C) 1258 then the following macros need to be defined (examples are 1259 from include/configs/lwmon.h): 1260 1261 I2C_INIT 1262 1263 (Optional). Any commands necessary to enable the I2C 1264 controller or configure ports. 1265 1266 eg: #define I2C_INIT (immr->im_cpm.cp_pbdir |= PB_SCL) 1267 1268 I2C_PORT 1269 1270 (Only for MPC8260 CPU). The I/O port to use (the code 1271 assumes both bits are on the same port). Valid values 1272 are 0..3 for ports A..D. 1273 1274 I2C_ACTIVE 1275 1276 The code necessary to make the I2C data line active 1277 (driven). If the data line is open collector, this 1278 define can be null. 1279 1280 eg: #define I2C_ACTIVE (immr->im_cpm.cp_pbdir |= PB_SDA) 1281 1282 I2C_TRISTATE 1283 1284 The code necessary to make the I2C data line tri-stated 1285 (inactive). If the data line is open collector, this 1286 define can be null. 1287 1288 eg: #define I2C_TRISTATE (immr->im_cpm.cp_pbdir &= ~PB_SDA) 1289 1290 I2C_READ 1291 1292 Code that returns TRUE if the I2C data line is high, 1293 FALSE if it is low. 1294 1295 eg: #define I2C_READ ((immr->im_cpm.cp_pbdat & PB_SDA) != 0) 1296 1297 I2C_SDA(bit) 1298 1299 If <bit> is TRUE, sets the I2C data line high. If it 1300 is FALSE, it clears it (low). 1301 1302 eg: #define I2C_SDA(bit) \ 1303 if(bit) immr->im_cpm.cp_pbdat |= PB_SDA; \ 1304 else immr->im_cpm.cp_pbdat &= ~PB_SDA 1305 1306 I2C_SCL(bit) 1307 1308 If <bit> is TRUE, sets the I2C clock line high. If it 1309 is FALSE, it clears it (low). 1310 1311 eg: #define I2C_SCL(bit) \ 1312 if(bit) immr->im_cpm.cp_pbdat |= PB_SCL; \ 1313 else immr->im_cpm.cp_pbdat &= ~PB_SCL 1314 1315 I2C_DELAY 1316 1317 This delay is invoked four times per clock cycle so this 1318 controls the rate of data transfer. The data rate thus 1319 is 1 / (I2C_DELAY * 4). Often defined to be something 1320 like: 1321 1322 #define I2C_DELAY udelay(2) 1323 1324 CFG_I2C_INIT_BOARD 1325 1326 When a board is reset during an i2c bus transfer 1327 chips might think that the current transfer is still 1328 in progress. On some boards it is possible to access 1329 the i2c SCLK line directly, either by using the 1330 processor pin as a GPIO or by having a second pin 1331 connected to the bus. If this option is defined a 1332 custom i2c_init_board() routine in boards/xxx/board.c 1333 is run early in the boot sequence. 1334 1335 CONFIG_I2CFAST (PPC405GP|PPC405EP only) 1336 1337 This option enables configuration of bi_iic_fast[] flags 1338 in u-boot bd_info structure based on u-boot environment 1339 variable "i2cfast". (see also i2cfast) 1340 1341 CONFIG_I2C_MULTI_BUS 1342 1343 This option allows the use of multiple I2C buses, each of which 1344 must have a controller. At any point in time, only one bus is 1345 active. To switch to a different bus, use the 'i2c dev' command. 1346 Note that bus numbering is zero-based. 1347 1348 CFG_I2C_NOPROBES 1349 1350 This option specifies a list of I2C devices that will be skipped 1351 when the 'i2c probe' command is issued (or 'iprobe' using the legacy 1352 command). If CONFIG_I2C_MULTI_BUS is set, specify a list of bus-device 1353 pairs. Otherwise, specify a 1D array of device addresses 1354 1355 e.g. 1356 #undef CONFIG_I2C_MULTI_BUS 1357 #define CFG_I2C_NOPROBES {0x50,0x68} 1358 1359 will skip addresses 0x50 and 0x68 on a board with one I2C bus 1360 1361 #define CONFIG_I2C_MULTI_BUS 1362 #define CFG_I2C_MULTI_NOPROBES {{0,0x50},{0,0x68},{1,0x54}} 1363 1364 will skip addresses 0x50 and 0x68 on bus 0 and address 0x54 on bus 1 1365 1366 CFG_SPD_BUS_NUM 1367 1368 If defined, then this indicates the I2C bus number for DDR SPD. 1369 If not defined, then U-Boot assumes that SPD is on I2C bus 0. 1370 1371 CFG_RTC_BUS_NUM 1372 1373 If defined, then this indicates the I2C bus number for the RTC. 1374 If not defined, then U-Boot assumes that RTC is on I2C bus 0. 1375 1376 CFG_DTT_BUS_NUM 1377 1378 If defined, then this indicates the I2C bus number for the DTT. 1379 If not defined, then U-Boot assumes that DTT is on I2C bus 0. 1380 1381 CONFIG_FSL_I2C 1382 1383 Define this option if you want to use Freescale's I2C driver in 1384 drivers/i2c/fsl_i2c.c. 1385 1386 1387- SPI Support: CONFIG_SPI 1388 1389 Enables SPI driver (so far only tested with 1390 SPI EEPROM, also an instance works with Crystal A/D and 1391 D/As on the SACSng board) 1392 1393 CONFIG_SPI_X 1394 1395 Enables extended (16-bit) SPI EEPROM addressing. 1396 (symmetrical to CONFIG_I2C_X) 1397 1398 CONFIG_SOFT_SPI 1399 1400 Enables a software (bit-bang) SPI driver rather than 1401 using hardware support. This is a general purpose 1402 driver that only requires three general I/O port pins 1403 (two outputs, one input) to function. If this is 1404 defined, the board configuration must define several 1405 SPI configuration items (port pins to use, etc). For 1406 an example, see include/configs/sacsng.h. 1407 1408 CONFIG_HARD_SPI 1409 1410 Enables a hardware SPI driver for general-purpose reads 1411 and writes. As with CONFIG_SOFT_SPI, the board configuration 1412 must define a list of chip-select function pointers. 1413 Currently supported on some MPC8xxx processors. For an 1414 example, see include/configs/mpc8349emds.h. 1415 1416- FPGA Support: CONFIG_FPGA 1417 1418 Enables FPGA subsystem. 1419 1420 CONFIG_FPGA_<vendor> 1421 1422 Enables support for specific chip vendors. 1423 (ALTERA, XILINX) 1424 1425 CONFIG_FPGA_<family> 1426 1427 Enables support for FPGA family. 1428 (SPARTAN2, SPARTAN3, VIRTEX2, CYCLONE2, ACEX1K, ACEX) 1429 1430 CONFIG_FPGA_COUNT 1431 1432 Specify the number of FPGA devices to support. 1433 1434 CFG_FPGA_PROG_FEEDBACK 1435 1436 Enable printing of hash marks during FPGA configuration. 1437 1438 CFG_FPGA_CHECK_BUSY 1439 1440 Enable checks on FPGA configuration interface busy 1441 status by the configuration function. This option 1442 will require a board or device specific function to 1443 be written. 1444 1445 CONFIG_FPGA_DELAY 1446 1447 If defined, a function that provides delays in the FPGA 1448 configuration driver. 1449 1450 CFG_FPGA_CHECK_CTRLC 1451 Allow Control-C to interrupt FPGA configuration 1452 1453 CFG_FPGA_CHECK_ERROR 1454 1455 Check for configuration errors during FPGA bitfile 1456 loading. For example, abort during Virtex II 1457 configuration if the INIT_B line goes low (which 1458 indicated a CRC error). 1459 1460 CFG_FPGA_WAIT_INIT 1461 1462 Maximum time to wait for the INIT_B line to deassert 1463 after PROB_B has been deasserted during a Virtex II 1464 FPGA configuration sequence. The default time is 500 1465 mS. 1466 1467 CFG_FPGA_WAIT_BUSY 1468 1469 Maximum time to wait for BUSY to deassert during 1470 Virtex II FPGA configuration. The default is 5 mS. 1471 1472 CFG_FPGA_WAIT_CONFIG 1473 1474 Time to wait after FPGA configuration. The default is 1475 200 mS. 1476 1477- Configuration Management: 1478 CONFIG_IDENT_STRING 1479 1480 If defined, this string will be added to the U-Boot 1481 version information (U_BOOT_VERSION) 1482 1483- Vendor Parameter Protection: 1484 1485 U-Boot considers the values of the environment 1486 variables "serial#" (Board Serial Number) and 1487 "ethaddr" (Ethernet Address) to be parameters that 1488 are set once by the board vendor / manufacturer, and 1489 protects these variables from casual modification by 1490 the user. Once set, these variables are read-only, 1491 and write or delete attempts are rejected. You can 1492 change this behviour: 1493 1494 If CONFIG_ENV_OVERWRITE is #defined in your config 1495 file, the write protection for vendor parameters is 1496 completely disabled. Anybody can change or delete 1497 these parameters. 1498 1499 Alternatively, if you #define _both_ CONFIG_ETHADDR 1500 _and_ CONFIG_OVERWRITE_ETHADDR_ONCE, a default 1501 ethernet address is installed in the environment, 1502 which can be changed exactly ONCE by the user. [The 1503 serial# is unaffected by this, i. e. it remains 1504 read-only.] 1505 1506- Protected RAM: 1507 CONFIG_PRAM 1508 1509 Define this variable to enable the reservation of 1510 "protected RAM", i. e. RAM which is not overwritten 1511 by U-Boot. Define CONFIG_PRAM to hold the number of 1512 kB you want to reserve for pRAM. You can overwrite 1513 this default value by defining an environment 1514 variable "pram" to the number of kB you want to 1515 reserve. Note that the board info structure will 1516 still show the full amount of RAM. If pRAM is 1517 reserved, a new environment variable "mem" will 1518 automatically be defined to hold the amount of 1519 remaining RAM in a form that can be passed as boot 1520 argument to Linux, for instance like that: 1521 1522 setenv bootargs ... mem=\${mem} 1523 saveenv 1524 1525 This way you can tell Linux not to use this memory, 1526 either, which results in a memory region that will 1527 not be affected by reboots. 1528 1529 *WARNING* If your board configuration uses automatic 1530 detection of the RAM size, you must make sure that 1531 this memory test is non-destructive. So far, the 1532 following board configurations are known to be 1533 "pRAM-clean": 1534 1535 ETX094, IVMS8, IVML24, SPD8xx, TQM8xxL, 1536 HERMES, IP860, RPXlite, LWMON, LANTEC, 1537 PCU_E, FLAGADM, TQM8260 1538 1539- Error Recovery: 1540 CONFIG_PANIC_HANG 1541 1542 Define this variable to stop the system in case of a 1543 fatal error, so that you have to reset it manually. 1544 This is probably NOT a good idea for an embedded 1545 system where you want to system to reboot 1546 automatically as fast as possible, but it may be 1547 useful during development since you can try to debug 1548 the conditions that lead to the situation. 1549 1550 CONFIG_NET_RETRY_COUNT 1551 1552 This variable defines the number of retries for 1553 network operations like ARP, RARP, TFTP, or BOOTP 1554 before giving up the operation. If not defined, a 1555 default value of 5 is used. 1556 1557- Command Interpreter: 1558 CONFIG_AUTO_COMPLETE 1559 1560 Enable auto completion of commands using TAB. 1561 1562 Note that this feature has NOT been implemented yet 1563 for the "hush" shell. 1564 1565 1566 CFG_HUSH_PARSER 1567 1568 Define this variable to enable the "hush" shell (from 1569 Busybox) as command line interpreter, thus enabling 1570 powerful command line syntax like 1571 if...then...else...fi conditionals or `&&' and '||' 1572 constructs ("shell scripts"). 1573 1574 If undefined, you get the old, much simpler behaviour 1575 with a somewhat smaller memory footprint. 1576 1577 1578 CFG_PROMPT_HUSH_PS2 1579 1580 This defines the secondary prompt string, which is 1581 printed when the command interpreter needs more input 1582 to complete a command. Usually "> ". 1583 1584 Note: 1585 1586 In the current implementation, the local variables 1587 space and global environment variables space are 1588 separated. Local variables are those you define by 1589 simply typing `name=value'. To access a local 1590 variable later on, you have write `$name' or 1591 `${name}'; to execute the contents of a variable 1592 directly type `$name' at the command prompt. 1593 1594 Global environment variables are those you use 1595 setenv/printenv to work with. To run a command stored 1596 in such a variable, you need to use the run command, 1597 and you must not use the '$' sign to access them. 1598 1599 To store commands and special characters in a 1600 variable, please use double quotation marks 1601 surrounding the whole text of the variable, instead 1602 of the backslashes before semicolons and special 1603 symbols. 1604 1605- Commandline Editing and History: 1606 CONFIG_CMDLINE_EDITING 1607 1608 Enable editiong and History functions for interactive 1609 commandline input operations 1610 1611- Default Environment: 1612 CONFIG_EXTRA_ENV_SETTINGS 1613 1614 Define this to contain any number of null terminated 1615 strings (variable = value pairs) that will be part of 1616 the default environment compiled into the boot image. 1617 1618 For example, place something like this in your 1619 board's config file: 1620 1621 #define CONFIG_EXTRA_ENV_SETTINGS \ 1622 "myvar1=value1\0" \ 1623 "myvar2=value2\0" 1624 1625 Warning: This method is based on knowledge about the 1626 internal format how the environment is stored by the 1627 U-Boot code. This is NOT an official, exported 1628 interface! Although it is unlikely that this format 1629 will change soon, there is no guarantee either. 1630 You better know what you are doing here. 1631 1632 Note: overly (ab)use of the default environment is 1633 discouraged. Make sure to check other ways to preset 1634 the environment like the autoscript function or the 1635 boot command first. 1636 1637- DataFlash Support: 1638 CONFIG_HAS_DATAFLASH 1639 1640 Defining this option enables DataFlash features and 1641 allows to read/write in Dataflash via the standard 1642 commands cp, md... 1643 1644- SystemACE Support: 1645 CONFIG_SYSTEMACE 1646 1647 Adding this option adds support for Xilinx SystemACE 1648 chips attached via some sort of local bus. The address 1649 of the chip must alsh be defined in the 1650 CFG_SYSTEMACE_BASE macro. For example: 1651 1652 #define CONFIG_SYSTEMACE 1653 #define CFG_SYSTEMACE_BASE 0xf0000000 1654 1655 When SystemACE support is added, the "ace" device type 1656 becomes available to the fat commands, i.e. fatls. 1657 1658- TFTP Fixed UDP Port: 1659 CONFIG_TFTP_PORT 1660 1661 If this is defined, the environment variable tftpsrcp 1662 is used to supply the TFTP UDP source port value. 1663 If tftpsrcp isn't defined, the normal pseudo-random port 1664 number generator is used. 1665 1666 Also, the environment variable tftpdstp is used to supply 1667 the TFTP UDP destination port value. If tftpdstp isn't 1668 defined, the normal port 69 is used. 1669 1670 The purpose for tftpsrcp is to allow a TFTP server to 1671 blindly start the TFTP transfer using the pre-configured 1672 target IP address and UDP port. This has the effect of 1673 "punching through" the (Windows XP) firewall, allowing 1674 the remainder of the TFTP transfer to proceed normally. 1675 A better solution is to properly configure the firewall, 1676 but sometimes that is not allowed. 1677 1678- Show boot progress: 1679 CONFIG_SHOW_BOOT_PROGRESS 1680 1681 Defining this option allows to add some board- 1682 specific code (calling a user-provided function 1683 "show_boot_progress(int)") that enables you to show 1684 the system's boot progress on some display (for 1685 example, some LED's) on your board. At the moment, 1686 the following checkpoints are implemented: 1687 1688Legacy uImage format: 1689 1690 Arg Where When 1691 1 common/cmd_bootm.c before attempting to boot an image 1692 -1 common/cmd_bootm.c Image header has bad magic number 1693 2 common/cmd_bootm.c Image header has correct magic number 1694 -2 common/cmd_bootm.c Image header has bad checksum 1695 3 common/cmd_bootm.c Image header has correct checksum 1696 -3 common/cmd_bootm.c Image data has bad checksum 1697 4 common/cmd_bootm.c Image data has correct checksum 1698 -4 common/cmd_bootm.c Image is for unsupported architecture 1699 5 common/cmd_bootm.c Architecture check OK 1700 -5 common/cmd_bootm.c Wrong Image Type (not kernel, multi) 1701 6 common/cmd_bootm.c Image Type check OK 1702 -6 common/cmd_bootm.c gunzip uncompression error 1703 -7 common/cmd_bootm.c Unimplemented compression type 1704 7 common/cmd_bootm.c Uncompression OK 1705 8 common/cmd_bootm.c No uncompress/copy overwrite error 1706 -9 common/cmd_bootm.c Unsupported OS (not Linux, BSD, VxWorks, QNX) 1707 1708 9 common/image.c Start initial ramdisk verification 1709 -10 common/image.c Ramdisk header has bad magic number 1710 -11 common/image.c Ramdisk header has bad checksum 1711 10 common/image.c Ramdisk header is OK 1712 -12 common/image.c Ramdisk data has bad checksum 1713 11 common/image.c Ramdisk data has correct checksum 1714 12 common/image.c Ramdisk verification complete, start loading 1715 -13 common/image.c Wrong Image Type (not PPC Linux Ramdisk) 1716 13 common/image.c Start multifile image verification 1717 14 common/image.c No initial ramdisk, no multifile, continue. 1718 1719 15 lib_<arch>/bootm.c All preparation done, transferring control to OS 1720 1721 -30 lib_ppc/board.c Fatal error, hang the system 1722 -31 post/post.c POST test failed, detected by post_output_backlog() 1723 -32 post/post.c POST test failed, detected by post_run_single() 1724 1725 34 common/cmd_doc.c before loading a Image from a DOC device 1726 -35 common/cmd_doc.c Bad usage of "doc" command 1727 35 common/cmd_doc.c correct usage of "doc" command 1728 -36 common/cmd_doc.c No boot device 1729 36 common/cmd_doc.c correct boot device 1730 -37 common/cmd_doc.c Unknown Chip ID on boot device 1731 37 common/cmd_doc.c correct chip ID found, device available 1732 -38 common/cmd_doc.c Read Error on boot device 1733 38 common/cmd_doc.c reading Image header from DOC device OK 1734 -39 common/cmd_doc.c Image header has bad magic number 1735 39 common/cmd_doc.c Image header has correct magic number 1736 -40 common/cmd_doc.c Error reading Image from DOC device 1737 40 common/cmd_doc.c Image header has correct magic number 1738 41 common/cmd_ide.c before loading a Image from a IDE device 1739 -42 common/cmd_ide.c Bad usage of "ide" command 1740 42 common/cmd_ide.c correct usage of "ide" command 1741 -43 common/cmd_ide.c No boot device 1742 43 common/cmd_ide.c boot device found 1743 -44 common/cmd_ide.c Device not available 1744 44 common/cmd_ide.c Device available 1745 -45 common/cmd_ide.c wrong partition selected 1746 45 common/cmd_ide.c partition selected 1747 -46 common/cmd_ide.c Unknown partition table 1748 46 common/cmd_ide.c valid partition table found 1749 -47 common/cmd_ide.c Invalid partition type 1750 47 common/cmd_ide.c correct partition type 1751 -48 common/cmd_ide.c Error reading Image Header on boot device 1752 48 common/cmd_ide.c reading Image Header from IDE device OK 1753 -49 common/cmd_ide.c Image header has bad magic number 1754 49 common/cmd_ide.c Image header has correct magic number 1755 -50 common/cmd_ide.c Image header has bad checksum 1756 50 common/cmd_ide.c Image header has correct checksum 1757 -51 common/cmd_ide.c Error reading Image from IDE device 1758 51 common/cmd_ide.c reading Image from IDE device OK 1759 52 common/cmd_nand.c before loading a Image from a NAND device 1760 -53 common/cmd_nand.c Bad usage of "nand" command 1761 53 common/cmd_nand.c correct usage of "nand" command 1762 -54 common/cmd_nand.c No boot device 1763 54 common/cmd_nand.c boot device found 1764 -55 common/cmd_nand.c Unknown Chip ID on boot device 1765 55 common/cmd_nand.c correct chip ID found, device available 1766 -56 common/cmd_nand.c Error reading Image Header on boot device 1767 56 common/cmd_nand.c reading Image Header from NAND device OK 1768 -57 common/cmd_nand.c Image header has bad magic number 1769 57 common/cmd_nand.c Image header has correct magic number 1770 -58 common/cmd_nand.c Error reading Image from NAND device 1771 58 common/cmd_nand.c reading Image from NAND device OK 1772 1773 -60 common/env_common.c Environment has a bad CRC, using default 1774 1775 64 net/eth.c starting with Ethernetconfiguration. 1776 -64 net/eth.c no Ethernet found. 1777 65 net/eth.c Ethernet found. 1778 1779 -80 common/cmd_net.c usage wrong 1780 80 common/cmd_net.c before calling NetLoop() 1781 -81 common/cmd_net.c some error in NetLoop() occured 1782 81 common/cmd_net.c NetLoop() back without error 1783 -82 common/cmd_net.c size == 0 (File with size 0 loaded) 1784 82 common/cmd_net.c trying automatic boot 1785 83 common/cmd_net.c running autoscript 1786 -83 common/cmd_net.c some error in automatic boot or autoscript 1787 84 common/cmd_net.c end without errors 1788 1789FIT uImage format: 1790 1791 Arg Where When 1792 100 common/cmd_bootm.c Kernel FIT Image has correct format 1793 -100 common/cmd_bootm.c Kernel FIT Image has incorrect format 1794 101 common/cmd_bootm.c No Kernel subimage unit name, using configuration 1795 -101 common/cmd_bootm.c Can't get configuration for kernel subimage 1796 102 common/cmd_bootm.c Kernel unit name specified 1797 -103 common/cmd_bootm.c Can't get kernel subimage node offset 1798 103 common/cmd_bootm.c Found configuration node 1799 104 common/cmd_bootm.c Got kernel subimage node offset 1800 -104 common/cmd_bootm.c Kernel subimage hash verification failed 1801 105 common/cmd_bootm.c Kernel subimage hash verification OK 1802 -105 common/cmd_bootm.c Kernel subimage is for unsupported architecture 1803 106 common/cmd_bootm.c Architecture check OK 1804 -106 common/cmd_bootm.c Kernel subimage has wrong typea 1805 107 common/cmd_bootm.c Kernel subimge type OK 1806 -107 common/cmd_bootm.c Can't get kernel subimage data/size 1807 108 common/cmd_bootm.c Got kernel subimage data/size 1808 -108 common/cmd_bootm.c Wrong image type (not legacy, FIT) 1809 -109 common/cmd_bootm.c Can't get kernel subimage type 1810 -110 common/cmd_bootm.c Can't get kernel subimage comp 1811 -111 common/cmd_bootm.c Can't get kernel subimage os 1812 -112 common/cmd_bootm.c Can't get kernel subimage load address 1813 -113 common/cmd_bootm.c Image uncompress/copy overwrite error 1814 1815 120 common/image.c Start initial ramdisk verification 1816 -120 common/image.c Ramdisk FIT image has incorrect format 1817 121 common/image.c Ramdisk FIT image has correct format 1818 122 common/image.c No Ramdisk subimage unit name, using configuration 1819 -122 common/image.c Can't get configuration for ramdisk subimage 1820 123 common/image.c Ramdisk unit name specified 1821 -124 common/image.c Can't get ramdisk subimage node offset 1822 125 common/image.c Got ramdisk subimage node offset 1823 -125 common/image.c Ramdisk subimage hash verification failed 1824 126 common/image.c Ramdisk subimage hash verification OK 1825 -126 common/image.c Ramdisk subimage for unsupported architecture 1826 127 common/image.c Architecture check OK 1827 -127 common/image.c Can't get ramdisk subimage data/size 1828 128 common/image.c Got ramdisk subimage data/size 1829 129 common/image.c Can't get ramdisk load address 1830 -129 common/image.c Got ramdisk load address 1831 1832 -130 common/cmd_doc.c Icorrect FIT image format 1833 131 common/cmd_doc.c FIT image format OK 1834 1835 -140 common/cmd_ide.c Icorrect FIT image format 1836 141 common/cmd_ide.c FIT image format OK 1837 1838 -150 common/cmd_nand.c Icorrect FIT image format 1839 151 common/cmd_nand.c FIT image format OK 1840 1841 1842Modem Support: 1843-------------- 1844 1845[so far only for SMDK2400 and TRAB boards] 1846 1847- Modem support endable: 1848 CONFIG_MODEM_SUPPORT 1849 1850- RTS/CTS Flow control enable: 1851 CONFIG_HWFLOW 1852 1853- Modem debug support: 1854 CONFIG_MODEM_SUPPORT_DEBUG 1855 1856 Enables debugging stuff (char screen[1024], dbg()) 1857 for modem support. Useful only with BDI2000. 1858 1859- Interrupt support (PPC): 1860 1861 There are common interrupt_init() and timer_interrupt() 1862 for all PPC archs. interrupt_init() calls interrupt_init_cpu() 1863 for cpu specific initialization. interrupt_init_cpu() 1864 should set decrementer_count to appropriate value. If 1865 cpu resets decrementer automatically after interrupt 1866 (ppc4xx) it should set decrementer_count to zero. 1867 timer_interrupt() calls timer_interrupt_cpu() for cpu 1868 specific handling. If board has watchdog / status_led 1869 / other_activity_monitor it works automatically from 1870 general timer_interrupt(). 1871 1872- General: 1873 1874 In the target system modem support is enabled when a 1875 specific key (key combination) is pressed during 1876 power-on. Otherwise U-Boot will boot normally 1877 (autoboot). The key_pressed() fuction is called from 1878 board_init(). Currently key_pressed() is a dummy 1879 function, returning 1 and thus enabling modem 1880 initialization. 1881 1882 If there are no modem init strings in the 1883 environment, U-Boot proceed to autoboot; the 1884 previous output (banner, info printfs) will be 1885 supressed, though. 1886 1887 See also: doc/README.Modem 1888 1889 1890Configuration Settings: 1891----------------------- 1892 1893- CFG_LONGHELP: Defined when you want long help messages included; 1894 undefine this when you're short of memory. 1895 1896- CFG_PROMPT: This is what U-Boot prints on the console to 1897 prompt for user input. 1898 1899- CFG_CBSIZE: Buffer size for input from the Console 1900 1901- CFG_PBSIZE: Buffer size for Console output 1902 1903- CFG_MAXARGS: max. Number of arguments accepted for monitor commands 1904 1905- CFG_BARGSIZE: Buffer size for Boot Arguments which are passed to 1906 the application (usually a Linux kernel) when it is 1907 booted 1908 1909- CFG_BAUDRATE_TABLE: 1910 List of legal baudrate settings for this board. 1911 1912- CFG_CONSOLE_INFO_QUIET 1913 Suppress display of console information at boot. 1914 1915- CFG_CONSOLE_IS_IN_ENV 1916 If the board specific function 1917 extern int overwrite_console (void); 1918 returns 1, the stdin, stderr and stdout are switched to the 1919 serial port, else the settings in the environment are used. 1920 1921- CFG_CONSOLE_OVERWRITE_ROUTINE 1922 Enable the call to overwrite_console(). 1923 1924- CFG_CONSOLE_ENV_OVERWRITE 1925 Enable overwrite of previous console environment settings. 1926 1927- CFG_MEMTEST_START, CFG_MEMTEST_END: 1928 Begin and End addresses of the area used by the 1929 simple memory test. 1930 1931- CFG_ALT_MEMTEST: 1932 Enable an alternate, more extensive memory test. 1933 1934- CFG_MEMTEST_SCRATCH: 1935 Scratch address used by the alternate memory test 1936 You only need to set this if address zero isn't writeable 1937 1938- CFG_MEM_TOP_HIDE (PPC only): 1939 If CFG_MEM_TOP_HIDE is defined in the board config header, 1940 this specified memory area will get subtracted from the top 1941 (end) of ram and won't get "touched" at all by U-Boot. By 1942 fixing up gd->ram_size the Linux kernel should gets passed 1943 the now "corrected" memory size and won't touch it either. 1944 This should work for arch/ppc and arch/powerpc. Only Linux 1945 board ports in arch/powerpc with bootwrapper support that 1946 recalculate the memory size from the SDRAM controller setup 1947 will have to get fixed in Linux additionally. 1948 1949 This option can be used as a workaround for the 440EPx/GRx 1950 CHIP 11 errata where the last 256 bytes in SDRAM shouldn't 1951 be touched. 1952 1953 WARNING: Please make sure that this value is a multiple of 1954 the Linux page size (normally 4k). If this is not the case, 1955 then the end address of the Linux memory will be located at a 1956 non page size aligned address and this could cause major 1957 problems. 1958 1959- CFG_TFTP_LOADADDR: 1960 Default load address for network file downloads 1961 1962- CFG_LOADS_BAUD_CHANGE: 1963 Enable temporary baudrate change while serial download 1964 1965- CFG_SDRAM_BASE: 1966 Physical start address of SDRAM. _Must_ be 0 here. 1967 1968- CFG_MBIO_BASE: 1969 Physical start address of Motherboard I/O (if using a 1970 Cogent motherboard) 1971 1972- CFG_FLASH_BASE: 1973 Physical start address of Flash memory. 1974 1975- CFG_MONITOR_BASE: 1976 Physical start address of boot monitor code (set by 1977 make config files to be same as the text base address 1978 (TEXT_BASE) used when linking) - same as 1979 CFG_FLASH_BASE when booting from flash. 1980 1981- CFG_MONITOR_LEN: 1982 Size of memory reserved for monitor code, used to 1983 determine _at_compile_time_ (!) if the environment is 1984 embedded within the U-Boot image, or in a separate 1985 flash sector. 1986 1987- CFG_MALLOC_LEN: 1988 Size of DRAM reserved for malloc() use. 1989 1990- CFG_BOOTM_LEN: 1991 Normally compressed uImages are limited to an 1992 uncompressed size of 8 MBytes. If this is not enough, 1993 you can define CFG_BOOTM_LEN in your board config file 1994 to adjust this setting to your needs. 1995 1996- CFG_BOOTMAPSZ: 1997 Maximum size of memory mapped by the startup code of 1998 the Linux kernel; all data that must be processed by 1999 the Linux kernel (bd_info, boot arguments, eventually 2000 initrd image) must be put below this limit. 2001 2002- CFG_MAX_FLASH_BANKS: 2003 Max number of Flash memory banks 2004 2005- CFG_MAX_FLASH_SECT: 2006 Max number of sectors on a Flash chip 2007 2008- CFG_FLASH_ERASE_TOUT: 2009 Timeout for Flash erase operations (in ms) 2010 2011- CFG_FLASH_WRITE_TOUT: 2012 Timeout for Flash write operations (in ms) 2013 2014- CFG_FLASH_LOCK_TOUT 2015 Timeout for Flash set sector lock bit operation (in ms) 2016 2017- CFG_FLASH_UNLOCK_TOUT 2018 Timeout for Flash clear lock bits operation (in ms) 2019 2020- CFG_FLASH_PROTECTION 2021 If defined, hardware flash sectors protection is used 2022 instead of U-Boot software protection. 2023 2024- CFG_DIRECT_FLASH_TFTP: 2025 2026 Enable TFTP transfers directly to flash memory; 2027 without this option such a download has to be 2028 performed in two steps: (1) download to RAM, and (2) 2029 copy from RAM to flash. 2030 2031 The two-step approach is usually more reliable, since 2032 you can check if the download worked before you erase 2033 the flash, but in some situations (when sytem RAM is 2034 too limited to allow for a tempory copy of the 2035 downloaded image) this option may be very useful. 2036 2037- CFG_FLASH_CFI: 2038 Define if the flash driver uses extra elements in the 2039 common flash structure for storing flash geometry. 2040 2041- CFG_FLASH_CFI_DRIVER 2042 This option also enables the building of the cfi_flash driver 2043 in the drivers directory 2044 2045- CFG_FLASH_QUIET_TEST 2046 If this option is defined, the common CFI flash doesn't 2047 print it's warning upon not recognized FLASH banks. This 2048 is useful, if some of the configured banks are only 2049 optionally available. 2050 2051- CONFIG_FLASH_SHOW_PROGRESS 2052 If defined (must be an integer), print out countdown 2053 digits and dots. Recommended value: 45 (9..1) for 80 2054 column displays, 15 (3..1) for 40 column displays. 2055 2056- CFG_RX_ETH_BUFFER: 2057 Defines the number of ethernet receive buffers. On some 2058 ethernet controllers it is recommended to set this value 2059 to 8 or even higher (EEPRO100 or 405 EMAC), since all 2060 buffers can be full shortly after enabling the interface 2061 on high ethernet traffic. 2062 Defaults to 4 if not defined. 2063 2064The following definitions that deal with the placement and management 2065of environment data (variable area); in general, we support the 2066following configurations: 2067 2068- CFG_ENV_IS_IN_FLASH: 2069 2070 Define this if the environment is in flash memory. 2071 2072 a) The environment occupies one whole flash sector, which is 2073 "embedded" in the text segment with the U-Boot code. This 2074 happens usually with "bottom boot sector" or "top boot 2075 sector" type flash chips, which have several smaller 2076 sectors at the start or the end. For instance, such a 2077 layout can have sector sizes of 8, 2x4, 16, Nx32 kB. In 2078 such a case you would place the environment in one of the 2079 4 kB sectors - with U-Boot code before and after it. With 2080 "top boot sector" type flash chips, you would put the 2081 environment in one of the last sectors, leaving a gap 2082 between U-Boot and the environment. 2083 2084 - CFG_ENV_OFFSET: 2085 2086 Offset of environment data (variable area) to the 2087 beginning of flash memory; for instance, with bottom boot 2088 type flash chips the second sector can be used: the offset 2089 for this sector is given here. 2090 2091 CFG_ENV_OFFSET is used relative to CFG_FLASH_BASE. 2092 2093 - CFG_ENV_ADDR: 2094 2095 This is just another way to specify the start address of 2096 the flash sector containing the environment (instead of 2097 CFG_ENV_OFFSET). 2098 2099 - CFG_ENV_SECT_SIZE: 2100 2101 Size of the sector containing the environment. 2102 2103 2104 b) Sometimes flash chips have few, equal sized, BIG sectors. 2105 In such a case you don't want to spend a whole sector for 2106 the environment. 2107 2108 - CFG_ENV_SIZE: 2109 2110 If you use this in combination with CFG_ENV_IS_IN_FLASH 2111 and CFG_ENV_SECT_SIZE, you can specify to use only a part 2112 of this flash sector for the environment. This saves 2113 memory for the RAM copy of the environment. 2114 2115 It may also save flash memory if you decide to use this 2116 when your environment is "embedded" within U-Boot code, 2117 since then the remainder of the flash sector could be used 2118 for U-Boot code. It should be pointed out that this is 2119 STRONGLY DISCOURAGED from a robustness point of view: 2120 updating the environment in flash makes it always 2121 necessary to erase the WHOLE sector. If something goes 2122 wrong before the contents has been restored from a copy in 2123 RAM, your target system will be dead. 2124 2125 - CFG_ENV_ADDR_REDUND 2126 CFG_ENV_SIZE_REDUND 2127 2128 These settings describe a second storage area used to hold 2129 a redundand copy of the environment data, so that there is 2130 a valid backup copy in case there is a power failure during 2131 a "saveenv" operation. 2132 2133BE CAREFUL! Any changes to the flash layout, and some changes to the 2134source code will make it necessary to adapt <board>/u-boot.lds* 2135accordingly! 2136 2137 2138- CFG_ENV_IS_IN_NVRAM: 2139 2140 Define this if you have some non-volatile memory device 2141 (NVRAM, battery buffered SRAM) which you want to use for the 2142 environment. 2143 2144 - CFG_ENV_ADDR: 2145 - CFG_ENV_SIZE: 2146 2147 These two #defines are used to determin the memory area you 2148 want to use for environment. It is assumed that this memory 2149 can just be read and written to, without any special 2150 provision. 2151 2152BE CAREFUL! The first access to the environment happens quite early 2153in U-Boot initalization (when we try to get the setting of for the 2154console baudrate). You *MUST* have mappend your NVRAM area then, or 2155U-Boot will hang. 2156 2157Please note that even with NVRAM we still use a copy of the 2158environment in RAM: we could work on NVRAM directly, but we want to 2159keep settings there always unmodified except somebody uses "saveenv" 2160to save the current settings. 2161 2162 2163- CFG_ENV_IS_IN_EEPROM: 2164 2165 Use this if you have an EEPROM or similar serial access 2166 device and a driver for it. 2167 2168 - CFG_ENV_OFFSET: 2169 - CFG_ENV_SIZE: 2170 2171 These two #defines specify the offset and size of the 2172 environment area within the total memory of your EEPROM. 2173 2174 - CFG_I2C_EEPROM_ADDR: 2175 If defined, specified the chip address of the EEPROM device. 2176 The default address is zero. 2177 2178 - CFG_EEPROM_PAGE_WRITE_BITS: 2179 If defined, the number of bits used to address bytes in a 2180 single page in the EEPROM device. A 64 byte page, for example 2181 would require six bits. 2182 2183 - CFG_EEPROM_PAGE_WRITE_DELAY_MS: 2184 If defined, the number of milliseconds to delay between 2185 page writes. The default is zero milliseconds. 2186 2187 - CFG_I2C_EEPROM_ADDR_LEN: 2188 The length in bytes of the EEPROM memory array address. Note 2189 that this is NOT the chip address length! 2190 2191 - CFG_I2C_EEPROM_ADDR_OVERFLOW: 2192 EEPROM chips that implement "address overflow" are ones 2193 like Catalyst 24WC04/08/16 which has 9/10/11 bits of 2194 address and the extra bits end up in the "chip address" bit 2195 slots. This makes a 24WC08 (1Kbyte) chip look like four 256 2196 byte chips. 2197 2198 Note that we consider the length of the address field to 2199 still be one byte because the extra address bits are hidden 2200 in the chip address. 2201 2202 - CFG_EEPROM_SIZE: 2203 The size in bytes of the EEPROM device. 2204 2205 2206- CFG_ENV_IS_IN_DATAFLASH: 2207 2208 Define this if you have a DataFlash memory device which you 2209 want to use for the environment. 2210 2211 - CFG_ENV_OFFSET: 2212 - CFG_ENV_ADDR: 2213 - CFG_ENV_SIZE: 2214 2215 These three #defines specify the offset and size of the 2216 environment area within the total memory of your DataFlash placed 2217 at the specified address. 2218 2219- CFG_ENV_IS_IN_NAND: 2220 2221 Define this if you have a NAND device which you want to use 2222 for the environment. 2223 2224 - CFG_ENV_OFFSET: 2225 - CFG_ENV_SIZE: 2226 2227 These two #defines specify the offset and size of the environment 2228 area within the first NAND device. 2229 2230 - CFG_ENV_OFFSET_REDUND 2231 2232 This setting describes a second storage area of CFG_ENV_SIZE 2233 size used to hold a redundant copy of the environment data, 2234 so that there is a valid backup copy in case there is a 2235 power failure during a "saveenv" operation. 2236 2237 Note: CFG_ENV_OFFSET and CFG_ENV_OFFSET_REDUND must be aligned 2238 to a block boundary, and CFG_ENV_SIZE must be a multiple of 2239 the NAND devices block size. 2240 2241- CFG_SPI_INIT_OFFSET 2242 2243 Defines offset to the initial SPI buffer area in DPRAM. The 2244 area is used at an early stage (ROM part) if the environment 2245 is configured to reside in the SPI EEPROM: We need a 520 byte 2246 scratch DPRAM area. It is used between the two initialization 2247 calls (spi_init_f() and spi_init_r()). A value of 0xB00 seems 2248 to be a good choice since it makes it far enough from the 2249 start of the data area as well as from the stack pointer. 2250 2251Please note that the environment is read-only until the monitor 2252has been relocated to RAM and a RAM copy of the environment has been 2253created; also, when using EEPROM you will have to use getenv_r() 2254until then to read environment variables. 2255 2256The environment is protected by a CRC32 checksum. Before the monitor 2257is relocated into RAM, as a result of a bad CRC you will be working 2258with the compiled-in default environment - *silently*!!! [This is 2259necessary, because the first environment variable we need is the 2260"baudrate" setting for the console - if we have a bad CRC, we don't 2261have any device yet where we could complain.] 2262 2263Note: once the monitor has been relocated, then it will complain if 2264the default environment is used; a new CRC is computed as soon as you 2265use the "saveenv" command to store a valid environment. 2266 2267- CFG_FAULT_ECHO_LINK_DOWN: 2268 Echo the inverted Ethernet link state to the fault LED. 2269 2270 Note: If this option is active, then CFG_FAULT_MII_ADDR 2271 also needs to be defined. 2272 2273- CFG_FAULT_MII_ADDR: 2274 MII address of the PHY to check for the Ethernet link state. 2275 2276- CFG_64BIT_VSPRINTF: 2277 Makes vsprintf (and all *printf functions) support printing 2278 of 64bit values by using the L quantifier 2279 2280- CFG_64BIT_STRTOUL: 2281 Adds simple_strtoull that returns a 64bit value 2282 2283Low Level (hardware related) configuration options: 2284--------------------------------------------------- 2285 2286- CFG_CACHELINE_SIZE: 2287 Cache Line Size of the CPU. 2288 2289- CFG_DEFAULT_IMMR: 2290 Default address of the IMMR after system reset. 2291 2292 Needed on some 8260 systems (MPC8260ADS, PQ2FADS-ZU, 2293 and RPXsuper) to be able to adjust the position of 2294 the IMMR register after a reset. 2295 2296- Floppy Disk Support: 2297 CFG_FDC_DRIVE_NUMBER 2298 2299 the default drive number (default value 0) 2300 2301 CFG_ISA_IO_STRIDE 2302 2303 defines the spacing between fdc chipset registers 2304 (default value 1) 2305 2306 CFG_ISA_IO_OFFSET 2307 2308 defines the offset of register from address. It 2309 depends on which part of the data bus is connected to 2310 the fdc chipset. (default value 0) 2311 2312 If CFG_ISA_IO_STRIDE CFG_ISA_IO_OFFSET and 2313 CFG_FDC_DRIVE_NUMBER are undefined, they take their 2314 default value. 2315 2316 if CFG_FDC_HW_INIT is defined, then the function 2317 fdc_hw_init() is called at the beginning of the FDC 2318 setup. fdc_hw_init() must be provided by the board 2319 source code. It is used to make hardware dependant 2320 initializations. 2321 2322- CFG_IMMR: Physical address of the Internal Memory. 2323 DO NOT CHANGE unless you know exactly what you're 2324 doing! (11-4) [MPC8xx/82xx systems only] 2325 2326- CFG_INIT_RAM_ADDR: 2327 2328 Start address of memory area that can be used for 2329 initial data and stack; please note that this must be 2330 writable memory that is working WITHOUT special 2331 initialization, i. e. you CANNOT use normal RAM which 2332 will become available only after programming the 2333 memory controller and running certain initialization 2334 sequences. 2335 2336 U-Boot uses the following memory types: 2337 - MPC8xx and MPC8260: IMMR (internal memory of the CPU) 2338 - MPC824X: data cache 2339 - PPC4xx: data cache 2340 2341- CFG_GBL_DATA_OFFSET: 2342 2343 Offset of the initial data structure in the memory 2344 area defined by CFG_INIT_RAM_ADDR. Usually 2345 CFG_GBL_DATA_OFFSET is chosen such that the initial 2346 data is located at the end of the available space 2347 (sometimes written as (CFG_INIT_RAM_END - 2348 CFG_INIT_DATA_SIZE), and the initial stack is just 2349 below that area (growing from (CFG_INIT_RAM_ADDR + 2350 CFG_GBL_DATA_OFFSET) downward. 2351 2352 Note: 2353 On the MPC824X (or other systems that use the data 2354 cache for initial memory) the address chosen for 2355 CFG_INIT_RAM_ADDR is basically arbitrary - it must 2356 point to an otherwise UNUSED address space between 2357 the top of RAM and the start of the PCI space. 2358 2359- CFG_SIUMCR: SIU Module Configuration (11-6) 2360 2361- CFG_SYPCR: System Protection Control (11-9) 2362 2363- CFG_TBSCR: Time Base Status and Control (11-26) 2364 2365- CFG_PISCR: Periodic Interrupt Status and Control (11-31) 2366 2367- CFG_PLPRCR: PLL, Low-Power, and Reset Control Register (15-30) 2368 2369- CFG_SCCR: System Clock and reset Control Register (15-27) 2370 2371- CFG_OR_TIMING_SDRAM: 2372 SDRAM timing 2373 2374- CFG_MAMR_PTA: 2375 periodic timer for refresh 2376 2377- CFG_DER: Debug Event Register (37-47) 2378 2379- FLASH_BASE0_PRELIM, FLASH_BASE1_PRELIM, CFG_REMAP_OR_AM, 2380 CFG_PRELIM_OR_AM, CFG_OR_TIMING_FLASH, CFG_OR0_REMAP, 2381 CFG_OR0_PRELIM, CFG_BR0_PRELIM, CFG_OR1_REMAP, CFG_OR1_PRELIM, 2382 CFG_BR1_PRELIM: 2383 Memory Controller Definitions: BR0/1 and OR0/1 (FLASH) 2384 2385- SDRAM_BASE2_PRELIM, SDRAM_BASE3_PRELIM, SDRAM_MAX_SIZE, 2386 CFG_OR_TIMING_SDRAM, CFG_OR2_PRELIM, CFG_BR2_PRELIM, 2387 CFG_OR3_PRELIM, CFG_BR3_PRELIM: 2388 Memory Controller Definitions: BR2/3 and OR2/3 (SDRAM) 2389 2390- CFG_MAMR_PTA, CFG_MPTPR_2BK_4K, CFG_MPTPR_1BK_4K, CFG_MPTPR_2BK_8K, 2391 CFG_MPTPR_1BK_8K, CFG_MAMR_8COL, CFG_MAMR_9COL: 2392 Machine Mode Register and Memory Periodic Timer 2393 Prescaler definitions (SDRAM timing) 2394 2395- CFG_I2C_UCODE_PATCH, CFG_I2C_DPMEM_OFFSET [0x1FC0]: 2396 enable I2C microcode relocation patch (MPC8xx); 2397 define relocation offset in DPRAM [DSP2] 2398 2399- CFG_SMC_UCODE_PATCH, CFG_SMC_DPMEM_OFFSET [0x1FC0]: 2400 enable SMC microcode relocation patch (MPC8xx); 2401 define relocation offset in DPRAM [SMC1] 2402 2403- CFG_SPI_UCODE_PATCH, CFG_SPI_DPMEM_OFFSET [0x1FC0]: 2404 enable SPI microcode relocation patch (MPC8xx); 2405 define relocation offset in DPRAM [SCC4] 2406 2407- CFG_USE_OSCCLK: 2408 Use OSCM clock mode on MBX8xx board. Be careful, 2409 wrong setting might damage your board. Read 2410 doc/README.MBX before setting this variable! 2411 2412- CFG_CPM_POST_WORD_ADDR: (MPC8xx, MPC8260 only) 2413 Offset of the bootmode word in DPRAM used by post 2414 (Power On Self Tests). This definition overrides 2415 #define'd default value in commproc.h resp. 2416 cpm_8260.h. 2417 2418- CFG_PCI_SLV_MEM_LOCAL, CFG_PCI_SLV_MEM_BUS, CFG_PICMR0_MASK_ATTRIB, 2419 CFG_PCI_MSTR0_LOCAL, CFG_PCIMSK0_MASK, CFG_PCI_MSTR1_LOCAL, 2420 CFG_PCIMSK1_MASK, CFG_PCI_MSTR_MEM_LOCAL, CFG_PCI_MSTR_MEM_BUS, 2421 CFG_CPU_PCI_MEM_START, CFG_PCI_MSTR_MEM_SIZE, CFG_POCMR0_MASK_ATTRIB, 2422 CFG_PCI_MSTR_MEMIO_LOCAL, CFG_PCI_MSTR_MEMIO_BUS, CPU_PCI_MEMIO_START, 2423 CFG_PCI_MSTR_MEMIO_SIZE, CFG_POCMR1_MASK_ATTRIB, CFG_PCI_MSTR_IO_LOCAL, 2424 CFG_PCI_MSTR_IO_BUS, CFG_CPU_PCI_IO_START, CFG_PCI_MSTR_IO_SIZE, 2425 CFG_POCMR2_MASK_ATTRIB: (MPC826x only) 2426 Overrides the default PCI memory map in cpu/mpc8260/pci.c if set. 2427 2428- CONFIG_SPD_EEPROM 2429 Get DDR timing information from an I2C EEPROM. Common 2430 with pluggable memory modules such as SODIMMs 2431 2432 SPD_EEPROM_ADDRESS 2433 I2C address of the SPD EEPROM 2434 2435- CFG_SPD_BUS_NUM 2436 If SPD EEPROM is on an I2C bus other than the first 2437 one, specify here. Note that the value must resolve 2438 to something your driver can deal with. 2439 2440- CFG_83XX_DDR_USES_CS0 2441 Only for 83xx systems. If specified, then DDR should 2442 be configured using CS0 and CS1 instead of CS2 and CS3. 2443 2444- CFG_83XX_DDR_USES_CS0 2445 Only for 83xx systems. If specified, then DDR should 2446 be configured using CS0 and CS1 instead of CS2 and CS3. 2447 2448- CONFIG_ETHER_ON_FEC[12] 2449 Define to enable FEC[12] on a 8xx series processor. 2450 2451- CONFIG_FEC[12]_PHY 2452 Define to the hardcoded PHY address which corresponds 2453 to the given FEC; i. e. 2454 #define CONFIG_FEC1_PHY 4 2455 means that the PHY with address 4 is connected to FEC1 2456 2457 When set to -1, means to probe for first available. 2458 2459- CONFIG_FEC[12]_PHY_NORXERR 2460 The PHY does not have a RXERR line (RMII only). 2461 (so program the FEC to ignore it). 2462 2463- CONFIG_RMII 2464 Enable RMII mode for all FECs. 2465 Note that this is a global option, we can't 2466 have one FEC in standard MII mode and another in RMII mode. 2467 2468- CONFIG_CRC32_VERIFY 2469 Add a verify option to the crc32 command. 2470 The syntax is: 2471 2472 => crc32 -v <address> <count> <crc32> 2473 2474 Where address/count indicate a memory area 2475 and crc32 is the correct crc32 which the 2476 area should have. 2477 2478- CONFIG_LOOPW 2479 Add the "loopw" memory command. This only takes effect if 2480 the memory commands are activated globally (CONFIG_CMD_MEM). 2481 2482- CONFIG_MX_CYCLIC 2483 Add the "mdc" and "mwc" memory commands. These are cyclic 2484 "md/mw" commands. 2485 Examples: 2486 2487 => mdc.b 10 4 500 2488 This command will print 4 bytes (10,11,12,13) each 500 ms. 2489 2490 => mwc.l 100 12345678 10 2491 This command will write 12345678 to address 100 all 10 ms. 2492 2493 This only takes effect if the memory commands are activated 2494 globally (CONFIG_CMD_MEM). 2495 2496- CONFIG_SKIP_LOWLEVEL_INIT 2497- CONFIG_SKIP_RELOCATE_UBOOT 2498 2499 [ARM only] If these variables are defined, then 2500 certain low level initializations (like setting up 2501 the memory controller) are omitted and/or U-Boot does 2502 not relocate itself into RAM. 2503 Normally these variables MUST NOT be defined. The 2504 only exception is when U-Boot is loaded (to RAM) by 2505 some other boot loader or by a debugger which 2506 performs these intializations itself. 2507 2508 2509Building the Software: 2510====================== 2511 2512Building U-Boot has been tested in several native build environments 2513and in many different cross environments. Of course we cannot support 2514all possibly existing versions of cross development tools in all 2515(potentially obsolete) versions. In case of tool chain problems we 2516recommend to use the ELDK (see http://www.denx.de/wiki/DULG/ELDK) 2517which is extensively used to build and test U-Boot. 2518 2519If you are not using a native environment, it is assumed that you 2520have GNU cross compiling tools available in your path. In this case, 2521you must set the environment variable CROSS_COMPILE in your shell. 2522Note that no changes to the Makefile or any other source files are 2523necessary. For example using the ELDK on a 4xx CPU, please enter: 2524 2525 $ CROSS_COMPILE=ppc_4xx- 2526 $ export CROSS_COMPILE 2527 2528U-Boot is intended to be simple to build. After installing the 2529sources you must configure U-Boot for one specific board type. This 2530is done by typing: 2531 2532 make NAME_config 2533 2534where "NAME_config" is the name of one of the existing configu- 2535rations; see the main Makefile for supported names. 2536 2537Note: for some board special configuration names may exist; check if 2538 additional information is available from the board vendor; for 2539 instance, the TQM823L systems are available without (standard) 2540 or with LCD support. You can select such additional "features" 2541 when chosing the configuration, i. e. 2542 2543 make TQM823L_config 2544 - will configure for a plain TQM823L, i. e. no LCD support 2545 2546 make TQM823L_LCD_config 2547 - will configure for a TQM823L with U-Boot console on LCD 2548 2549 etc. 2550 2551 2552Finally, type "make all", and you should get some working U-Boot 2553images ready for download to / installation on your system: 2554 2555- "u-boot.bin" is a raw binary image 2556- "u-boot" is an image in ELF binary format 2557- "u-boot.srec" is in Motorola S-Record format 2558 2559By default the build is performed locally and the objects are saved 2560in the source directory. One of the two methods can be used to change 2561this behavior and build U-Boot to some external directory: 2562 25631. Add O= to the make command line invocations: 2564 2565 make O=/tmp/build distclean 2566 make O=/tmp/build NAME_config 2567 make O=/tmp/build all 2568 25692. Set environment variable BUILD_DIR to point to the desired location: 2570 2571 export BUILD_DIR=/tmp/build 2572 make distclean 2573 make NAME_config 2574 make all 2575 2576Note that the command line "O=" setting overrides the BUILD_DIR environment 2577variable. 2578 2579 2580Please be aware that the Makefiles assume you are using GNU make, so 2581for instance on NetBSD you might need to use "gmake" instead of 2582native "make". 2583 2584 2585If the system board that you have is not listed, then you will need 2586to port U-Boot to your hardware platform. To do this, follow these 2587steps: 2588 25891. Add a new configuration option for your board to the toplevel 2590 "Makefile" and to the "MAKEALL" script, using the existing 2591 entries as examples. Note that here and at many other places 2592 boards and other names are listed in alphabetical sort order. Please 2593 keep this order. 25942. Create a new directory to hold your board specific code. Add any 2595 files you need. In your board directory, you will need at least 2596 the "Makefile", a "<board>.c", "flash.c" and "u-boot.lds". 25973. Create a new configuration file "include/configs/<board>.h" for 2598 your board 25993. If you're porting U-Boot to a new CPU, then also create a new 2600 directory to hold your CPU specific code. Add any files you need. 26014. Run "make <board>_config" with your new name. 26025. Type "make", and you should get a working "u-boot.srec" file 2603 to be installed on your target system. 26046. Debug and solve any problems that might arise. 2605 [Of course, this last step is much harder than it sounds.] 2606 2607 2608Testing of U-Boot Modifications, Ports to New Hardware, etc.: 2609============================================================== 2610 2611If you have modified U-Boot sources (for instance added a new board 2612or support for new devices, a new CPU, etc.) you are expected to 2613provide feedback to the other developers. The feedback normally takes 2614the form of a "patch", i. e. a context diff against a certain (latest 2615official or latest in the git repository) version of U-Boot sources. 2616 2617But before you submit such a patch, please verify that your modifi- 2618cation did not break existing code. At least make sure that *ALL* of 2619the supported boards compile WITHOUT ANY compiler warnings. To do so, 2620just run the "MAKEALL" script, which will configure and build U-Boot 2621for ALL supported system. Be warned, this will take a while. You can 2622select which (cross) compiler to use by passing a `CROSS_COMPILE' 2623environment variable to the script, i. e. to use the ELDK cross tools 2624you can type 2625 2626 CROSS_COMPILE=ppc_8xx- MAKEALL 2627 2628or to build on a native PowerPC system you can type 2629 2630 CROSS_COMPILE=' ' MAKEALL 2631 2632When using the MAKEALL script, the default behaviour is to build 2633U-Boot in the source directory. This location can be changed by 2634setting the BUILD_DIR environment variable. Also, for each target 2635built, the MAKEALL script saves two log files (<target>.ERR and 2636<target>.MAKEALL) in the <source dir>/LOG directory. This default 2637location can be changed by setting the MAKEALL_LOGDIR environment 2638variable. For example: 2639 2640 export BUILD_DIR=/tmp/build 2641 export MAKEALL_LOGDIR=/tmp/log 2642 CROSS_COMPILE=ppc_8xx- MAKEALL 2643 2644With the above settings build objects are saved in the /tmp/build, 2645log files are saved in the /tmp/log and the source tree remains clean 2646during the whole build process. 2647 2648 2649See also "U-Boot Porting Guide" below. 2650 2651 2652Monitor Commands - Overview: 2653============================ 2654 2655go - start application at address 'addr' 2656run - run commands in an environment variable 2657bootm - boot application image from memory 2658bootp - boot image via network using BootP/TFTP protocol 2659tftpboot- boot image via network using TFTP protocol 2660 and env variables "ipaddr" and "serverip" 2661 (and eventually "gatewayip") 2662rarpboot- boot image via network using RARP/TFTP protocol 2663diskboot- boot from IDE devicebootd - boot default, i.e., run 'bootcmd' 2664loads - load S-Record file over serial line 2665loadb - load binary file over serial line (kermit mode) 2666md - memory display 2667mm - memory modify (auto-incrementing) 2668nm - memory modify (constant address) 2669mw - memory write (fill) 2670cp - memory copy 2671cmp - memory compare 2672crc32 - checksum calculation 2673imd - i2c memory display 2674imm - i2c memory modify (auto-incrementing) 2675inm - i2c memory modify (constant address) 2676imw - i2c memory write (fill) 2677icrc32 - i2c checksum calculation 2678iprobe - probe to discover valid I2C chip addresses 2679iloop - infinite loop on address range 2680isdram - print SDRAM configuration information 2681sspi - SPI utility commands 2682base - print or set address offset 2683printenv- print environment variables 2684setenv - set environment variables 2685saveenv - save environment variables to persistent storage 2686protect - enable or disable FLASH write protection 2687erase - erase FLASH memory 2688flinfo - print FLASH memory information 2689bdinfo - print Board Info structure 2690iminfo - print header information for application image 2691coninfo - print console devices and informations 2692ide - IDE sub-system 2693loop - infinite loop on address range 2694loopw - infinite write loop on address range 2695mtest - simple RAM test 2696icache - enable or disable instruction cache 2697dcache - enable or disable data cache 2698reset - Perform RESET of the CPU 2699echo - echo args to console 2700version - print monitor version 2701help - print online help 2702? - alias for 'help' 2703 2704 2705Monitor Commands - Detailed Description: 2706======================================== 2707 2708TODO. 2709 2710For now: just type "help <command>". 2711 2712 2713Environment Variables: 2714====================== 2715 2716U-Boot supports user configuration using Environment Variables which 2717can be made persistent by saving to Flash memory. 2718 2719Environment Variables are set using "setenv", printed using 2720"printenv", and saved to Flash using "saveenv". Using "setenv" 2721without a value can be used to delete a variable from the 2722environment. As long as you don't save the environment you are 2723working with an in-memory copy. In case the Flash area containing the 2724environment is erased by accident, a default environment is provided. 2725 2726Some configuration options can be set using Environment Variables: 2727 2728 baudrate - see CONFIG_BAUDRATE 2729 2730 bootdelay - see CONFIG_BOOTDELAY 2731 2732 bootcmd - see CONFIG_BOOTCOMMAND 2733 2734 bootargs - Boot arguments when booting an RTOS image 2735 2736 bootfile - Name of the image to load with TFTP 2737 2738 autoload - if set to "no" (any string beginning with 'n'), 2739 "bootp" will just load perform a lookup of the 2740 configuration from the BOOTP server, but not try to 2741 load any image using TFTP 2742 2743 autoscript - if set to "yes" commands like "loadb", "loady", 2744 "bootp", "tftpb", "rarpboot" and "nfs" will attempt 2745 to automatically run script images (by internally 2746 calling "autoscript"). 2747 2748 autoscript_uname - if script image is in a format (FIT) this 2749 variable is used to get script subimage unit name. 2750 2751 autostart - if set to "yes", an image loaded using the "bootp", 2752 "rarpboot", "tftpboot" or "diskboot" commands will 2753 be automatically started (by internally calling 2754 "bootm") 2755 2756 If set to "no", a standalone image passed to the 2757 "bootm" command will be copied to the load address 2758 (and eventually uncompressed), but NOT be started. 2759 This can be used to load and uncompress arbitrary 2760 data. 2761 2762 i2cfast - (PPC405GP|PPC405EP only) 2763 if set to 'y' configures Linux I2C driver for fast 2764 mode (400kHZ). This environment variable is used in 2765 initialization code. So, for changes to be effective 2766 it must be saved and board must be reset. 2767 2768 initrd_high - restrict positioning of initrd images: 2769 If this variable is not set, initrd images will be 2770 copied to the highest possible address in RAM; this 2771 is usually what you want since it allows for 2772 maximum initrd size. If for some reason you want to 2773 make sure that the initrd image is loaded below the 2774 CFG_BOOTMAPSZ limit, you can set this environment 2775 variable to a value of "no" or "off" or "0". 2776 Alternatively, you can set it to a maximum upper 2777 address to use (U-Boot will still check that it 2778 does not overwrite the U-Boot stack and data). 2779 2780 For instance, when you have a system with 16 MB 2781 RAM, and want to reserve 4 MB from use by Linux, 2782 you can do this by adding "mem=12M" to the value of 2783 the "bootargs" variable. However, now you must make 2784 sure that the initrd image is placed in the first 2785 12 MB as well - this can be done with 2786 2787 setenv initrd_high 00c00000 2788 2789 If you set initrd_high to 0xFFFFFFFF, this is an 2790 indication to U-Boot that all addresses are legal 2791 for the Linux kernel, including addresses in flash 2792 memory. In this case U-Boot will NOT COPY the 2793 ramdisk at all. This may be useful to reduce the 2794 boot time on your system, but requires that this 2795 feature is supported by your Linux kernel. 2796 2797 ipaddr - IP address; needed for tftpboot command 2798 2799 loadaddr - Default load address for commands like "bootp", 2800 "rarpboot", "tftpboot", "loadb" or "diskboot" 2801 2802 loads_echo - see CONFIG_LOADS_ECHO 2803 2804 serverip - TFTP server IP address; needed for tftpboot command 2805 2806 bootretry - see CONFIG_BOOT_RETRY_TIME 2807 2808 bootdelaykey - see CONFIG_AUTOBOOT_DELAY_STR 2809 2810 bootstopkey - see CONFIG_AUTOBOOT_STOP_STR 2811 2812 ethprime - When CONFIG_NET_MULTI is enabled controls which 2813 interface is used first. 2814 2815 ethact - When CONFIG_NET_MULTI is enabled controls which 2816 interface is currently active. For example you 2817 can do the following 2818 2819 => setenv ethact FEC ETHERNET 2820 => ping 192.168.0.1 # traffic sent on FEC ETHERNET 2821 => setenv ethact SCC ETHERNET 2822 => ping 10.0.0.1 # traffic sent on SCC ETHERNET 2823 2824 ethrotate - When set to "no" U-Boot does not go through all 2825 available network interfaces. 2826 It just stays at the currently selected interface. 2827 2828 netretry - When set to "no" each network operation will 2829 either succeed or fail without retrying. 2830 When set to "once" the network operation will 2831 fail when all the available network interfaces 2832 are tried once without success. 2833 Useful on scripts which control the retry operation 2834 themselves. 2835 2836 npe_ucode - see CONFIG_IXP4XX_NPE_EXT_UCOD 2837 if set load address for the npe microcode 2838 2839 tftpsrcport - If this is set, the value is used for TFTP's 2840 UDP source port. 2841 2842 tftpdstport - If this is set, the value is used for TFTP's UDP 2843 destination port instead of the Well Know Port 69. 2844 2845 vlan - When set to a value < 4095 the traffic over 2846 ethernet is encapsulated/received over 802.1q 2847 VLAN tagged frames. 2848 2849The following environment variables may be used and automatically 2850updated by the network boot commands ("bootp" and "rarpboot"), 2851depending the information provided by your boot server: 2852 2853 bootfile - see above 2854 dnsip - IP address of your Domain Name Server 2855 dnsip2 - IP address of your secondary Domain Name Server 2856 gatewayip - IP address of the Gateway (Router) to use 2857 hostname - Target hostname 2858 ipaddr - see above 2859 netmask - Subnet Mask 2860 rootpath - Pathname of the root filesystem on the NFS server 2861 serverip - see above 2862 2863 2864There are two special Environment Variables: 2865 2866 serial# - contains hardware identification information such 2867 as type string and/or serial number 2868 ethaddr - Ethernet address 2869 2870These variables can be set only once (usually during manufacturing of 2871the board). U-Boot refuses to delete or overwrite these variables 2872once they have been set once. 2873 2874 2875Further special Environment Variables: 2876 2877 ver - Contains the U-Boot version string as printed 2878 with the "version" command. This variable is 2879 readonly (see CONFIG_VERSION_VARIABLE). 2880 2881 2882Please note that changes to some configuration parameters may take 2883only effect after the next boot (yes, that's just like Windoze :-). 2884 2885 2886Command Line Parsing: 2887===================== 2888 2889There are two different command line parsers available with U-Boot: 2890the old "simple" one, and the much more powerful "hush" shell: 2891 2892Old, simple command line parser: 2893-------------------------------- 2894 2895- supports environment variables (through setenv / saveenv commands) 2896- several commands on one line, separated by ';' 2897- variable substitution using "... ${name} ..." syntax 2898- special characters ('$', ';') can be escaped by prefixing with '\', 2899 for example: 2900 setenv bootcmd bootm \${address} 2901- You can also escape text by enclosing in single apostrophes, for example: 2902 setenv addip 'setenv bootargs $bootargs ip=$ipaddr:$serverip:$gatewayip:$netmask:$hostname::off' 2903 2904Hush shell: 2905----------- 2906 2907- similar to Bourne shell, with control structures like 2908 if...then...else...fi, for...do...done; while...do...done, 2909 until...do...done, ... 2910- supports environment ("global") variables (through setenv / saveenv 2911 commands) and local shell variables (through standard shell syntax 2912 "name=value"); only environment variables can be used with "run" 2913 command 2914 2915General rules: 2916-------------- 2917 2918(1) If a command line (or an environment variable executed by a "run" 2919 command) contains several commands separated by semicolon, and 2920 one of these commands fails, then the remaining commands will be 2921 executed anyway. 2922 2923(2) If you execute several variables with one call to run (i. e. 2924 calling run with a list af variables as arguments), any failing 2925 command will cause "run" to terminate, i. e. the remaining 2926 variables are not executed. 2927 2928Note for Redundant Ethernet Interfaces: 2929======================================= 2930 2931Some boards come with redundant ethernet interfaces; U-Boot supports 2932such configurations and is capable of automatic selection of a 2933"working" interface when needed. MAC assignment works as follows: 2934 2935Network interfaces are numbered eth0, eth1, eth2, ... Corresponding 2936MAC addresses can be stored in the environment as "ethaddr" (=>eth0), 2937"eth1addr" (=>eth1), "eth2addr", ... 2938 2939If the network interface stores some valid MAC address (for instance 2940in SROM), this is used as default address if there is NO correspon- 2941ding setting in the environment; if the corresponding environment 2942variable is set, this overrides the settings in the card; that means: 2943 2944o If the SROM has a valid MAC address, and there is no address in the 2945 environment, the SROM's address is used. 2946 2947o If there is no valid address in the SROM, and a definition in the 2948 environment exists, then the value from the environment variable is 2949 used. 2950 2951o If both the SROM and the environment contain a MAC address, and 2952 both addresses are the same, this MAC address is used. 2953 2954o If both the SROM and the environment contain a MAC address, and the 2955 addresses differ, the value from the environment is used and a 2956 warning is printed. 2957 2958o If neither SROM nor the environment contain a MAC address, an error 2959 is raised. 2960 2961 2962Image Formats: 2963============== 2964 2965U-Boot is capable of booting (and performing other auxiliary operations on) 2966images in two formats: 2967 2968New uImage format (FIT) 2969----------------------- 2970 2971Flexible and powerful format based on Flattened Image Tree -- FIT (similar 2972to Flattened Device Tree). It allows the use of images with multiple 2973components (several kernels, ramdisks, etc.), with contents protected by 2974SHA1, MD5 or CRC32. More details are found in the doc/uImage.FIT directory. 2975 2976 2977Old uImage format 2978----------------- 2979 2980Old image format is based on binary files which can be basically anything, 2981preceded by a special header; see the definitions in include/image.h for 2982details; basically, the header defines the following image properties: 2983 2984* Target Operating System (Provisions for OpenBSD, NetBSD, FreeBSD, 2985 4.4BSD, Linux, SVR4, Esix, Solaris, Irix, SCO, Dell, NCR, VxWorks, 2986 LynxOS, pSOS, QNX, RTEMS, ARTOS; 2987 Currently supported: Linux, NetBSD, VxWorks, QNX, RTEMS, ARTOS, LynxOS). 2988* Target CPU Architecture (Provisions for Alpha, ARM, AVR32, Intel x86, 2989 IA64, MIPS, NIOS, PowerPC, IBM S390, SuperH, Sparc, Sparc 64 Bit; 2990 Currently supported: ARM, AVR32, Intel x86, MIPS, NIOS, PowerPC). 2991* Compression Type (uncompressed, gzip, bzip2) 2992* Load Address 2993* Entry Point 2994* Image Name 2995* Image Timestamp 2996 2997The header is marked by a special Magic Number, and both the header 2998and the data portions of the image are secured against corruption by 2999CRC32 checksums. 3000 3001 3002Linux Support: 3003============== 3004 3005Although U-Boot should support any OS or standalone application 3006easily, the main focus has always been on Linux during the design of 3007U-Boot. 3008 3009U-Boot includes many features that so far have been part of some 3010special "boot loader" code within the Linux kernel. Also, any 3011"initrd" images to be used are no longer part of one big Linux image; 3012instead, kernel and "initrd" are separate images. This implementation 3013serves several purposes: 3014 3015- the same features can be used for other OS or standalone 3016 applications (for instance: using compressed images to reduce the 3017 Flash memory footprint) 3018 3019- it becomes much easier to port new Linux kernel versions because 3020 lots of low-level, hardware dependent stuff are done by U-Boot 3021 3022- the same Linux kernel image can now be used with different "initrd" 3023 images; of course this also means that different kernel images can 3024 be run with the same "initrd". This makes testing easier (you don't 3025 have to build a new "zImage.initrd" Linux image when you just 3026 change a file in your "initrd"). Also, a field-upgrade of the 3027 software is easier now. 3028 3029 3030Linux HOWTO: 3031============ 3032 3033Porting Linux to U-Boot based systems: 3034--------------------------------------- 3035 3036U-Boot cannot save you from doing all the necessary modifications to 3037configure the Linux device drivers for use with your target hardware 3038(no, we don't intend to provide a full virtual machine interface to 3039Linux :-). 3040 3041But now you can ignore ALL boot loader code (in arch/ppc/mbxboot). 3042 3043Just make sure your machine specific header file (for instance 3044include/asm-ppc/tqm8xx.h) includes the same definition of the Board 3045Information structure as we define in include/u-boot.h, and make 3046sure that your definition of IMAP_ADDR uses the same value as your 3047U-Boot configuration in CFG_IMMR. 3048 3049 3050Configuring the Linux kernel: 3051----------------------------- 3052 3053No specific requirements for U-Boot. Make sure you have some root 3054device (initial ramdisk, NFS) for your target system. 3055 3056 3057Building a Linux Image: 3058----------------------- 3059 3060With U-Boot, "normal" build targets like "zImage" or "bzImage" are 3061not used. If you use recent kernel source, a new build target 3062"uImage" will exist which automatically builds an image usable by 3063U-Boot. Most older kernels also have support for a "pImage" target, 3064which was introduced for our predecessor project PPCBoot and uses a 3065100% compatible format. 3066 3067Example: 3068 3069 make TQM850L_config 3070 make oldconfig 3071 make dep 3072 make uImage 3073 3074The "uImage" build target uses a special tool (in 'tools/mkimage') to 3075encapsulate a compressed Linux kernel image with header information, 3076CRC32 checksum etc. for use with U-Boot. This is what we are doing: 3077 3078* build a standard "vmlinux" kernel image (in ELF binary format): 3079 3080* convert the kernel into a raw binary image: 3081 3082 ${CROSS_COMPILE}-objcopy -O binary \ 3083 -R .note -R .comment \ 3084 -S vmlinux linux.bin 3085 3086* compress the binary image: 3087 3088 gzip -9 linux.bin 3089 3090* package compressed binary image for U-Boot: 3091 3092 mkimage -A ppc -O linux -T kernel -C gzip \ 3093 -a 0 -e 0 -n "Linux Kernel Image" \ 3094 -d linux.bin.gz uImage 3095 3096 3097The "mkimage" tool can also be used to create ramdisk images for use 3098with U-Boot, either separated from the Linux kernel image, or 3099combined into one file. "mkimage" encapsulates the images with a 64 3100byte header containing information about target architecture, 3101operating system, image type, compression method, entry points, time 3102stamp, CRC32 checksums, etc. 3103 3104"mkimage" can be called in two ways: to verify existing images and 3105print the header information, or to build new images. 3106 3107In the first form (with "-l" option) mkimage lists the information 3108contained in the header of an existing U-Boot image; this includes 3109checksum verification: 3110 3111 tools/mkimage -l image 3112 -l ==> list image header information 3113 3114The second form (with "-d" option) is used to build a U-Boot image 3115from a "data file" which is used as image payload: 3116 3117 tools/mkimage -A arch -O os -T type -C comp -a addr -e ep \ 3118 -n name -d data_file image 3119 -A ==> set architecture to 'arch' 3120 -O ==> set operating system to 'os' 3121 -T ==> set image type to 'type' 3122 -C ==> set compression type 'comp' 3123 -a ==> set load address to 'addr' (hex) 3124 -e ==> set entry point to 'ep' (hex) 3125 -n ==> set image name to 'name' 3126 -d ==> use image data from 'datafile' 3127 3128Right now, all Linux kernels for PowerPC systems use the same load 3129address (0x00000000), but the entry point address depends on the 3130kernel version: 3131 3132- 2.2.x kernels have the entry point at 0x0000000C, 3133- 2.3.x and later kernels have the entry point at 0x00000000. 3134 3135So a typical call to build a U-Boot image would read: 3136 3137 -> tools/mkimage -n '2.4.4 kernel for TQM850L' \ 3138 > -A ppc -O linux -T kernel -C gzip -a 0 -e 0 \ 3139 > -d /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/ppc/coffboot/vmlinux.gz \ 3140 > examples/uImage.TQM850L 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 (gzip compressed) 3144 Data Size: 335725 Bytes = 327.86 kB = 0.32 MB 3145 Load Address: 0x00000000 3146 Entry Point: 0x00000000 3147 3148To verify the contents of the image (or check for corruption): 3149 3150 -> tools/mkimage -l examples/uImage.TQM850L 3151 Image Name: 2.4.4 kernel for TQM850L 3152 Created: Wed Jul 19 02:34:59 2000 3153 Image Type: PowerPC Linux Kernel Image (gzip compressed) 3154 Data Size: 335725 Bytes = 327.86 kB = 0.32 MB 3155 Load Address: 0x00000000 3156 Entry Point: 0x00000000 3157 3158NOTE: for embedded systems where boot time is critical you can trade 3159speed for memory and install an UNCOMPRESSED image instead: this 3160needs more space in Flash, but boots much faster since it does not 3161need to be uncompressed: 3162 3163 -> gunzip /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/ppc/coffboot/vmlinux.gz 3164 -> tools/mkimage -n '2.4.4 kernel for TQM850L' \ 3165 > -A ppc -O linux -T kernel -C none -a 0 -e 0 \ 3166 > -d /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/ppc/coffboot/vmlinux \ 3167 > examples/uImage.TQM850L-uncompressed 3168 Image Name: 2.4.4 kernel for TQM850L 3169 Created: Wed Jul 19 02:34:59 2000 3170 Image Type: PowerPC Linux Kernel Image (uncompressed) 3171 Data Size: 792160 Bytes = 773.59 kB = 0.76 MB 3172 Load Address: 0x00000000 3173 Entry Point: 0x00000000 3174 3175 3176Similar you can build U-Boot images from a 'ramdisk.image.gz' file 3177when your kernel is intended to use an initial ramdisk: 3178 3179 -> tools/mkimage -n 'Simple Ramdisk Image' \ 3180 > -A ppc -O linux -T ramdisk -C gzip \ 3181 > -d /LinuxPPC/images/SIMPLE-ramdisk.image.gz examples/simple-initrd 3182 Image Name: Simple Ramdisk Image 3183 Created: Wed Jan 12 14:01:50 2000 3184 Image Type: PowerPC Linux RAMDisk Image (gzip compressed) 3185 Data Size: 566530 Bytes = 553.25 kB = 0.54 MB 3186 Load Address: 0x00000000 3187 Entry Point: 0x00000000 3188 3189 3190Installing a Linux Image: 3191------------------------- 3192 3193To downloading a U-Boot image over the serial (console) interface, 3194you must convert the image to S-Record format: 3195 3196 objcopy -I binary -O srec examples/image examples/image.srec 3197 3198The 'objcopy' does not understand the information in the U-Boot 3199image header, so the resulting S-Record file will be relative to 3200address 0x00000000. To load it to a given address, you need to 3201specify the target address as 'offset' parameter with the 'loads' 3202command. 3203 3204Example: install the image to address 0x40100000 (which on the 3205TQM8xxL is in the first Flash bank): 3206 3207 => erase 40100000 401FFFFF 3208 3209 .......... done 3210 Erased 8 sectors 3211 3212 => loads 40100000 3213 ## Ready for S-Record download ... 3214 ~>examples/image.srec 3215 1 2 3 4 5 6 7 8 9 10 11 12 13 ... 3216 ... 3217 15989 15990 15991 15992 3218 [file transfer complete] 3219 [connected] 3220 ## Start Addr = 0x00000000 3221 3222 3223You can check the success of the download using the 'iminfo' command; 3224this includes a checksum verification so you can be sure no data 3225corruption happened: 3226 3227 => imi 40100000 3228 3229 ## Checking Image at 40100000 ... 3230 Image Name: 2.2.13 for initrd on TQM850L 3231 Image Type: PowerPC Linux Kernel Image (gzip compressed) 3232 Data Size: 335725 Bytes = 327 kB = 0 MB 3233 Load Address: 00000000 3234 Entry Point: 0000000c 3235 Verifying Checksum ... OK 3236 3237 3238Boot Linux: 3239----------- 3240 3241The "bootm" command is used to boot an application that is stored in 3242memory (RAM or Flash). In case of a Linux kernel image, the contents 3243of the "bootargs" environment variable is passed to the kernel as 3244parameters. You can check and modify this variable using the 3245"printenv" and "setenv" commands: 3246 3247 3248 => printenv bootargs 3249 bootargs=root=/dev/ram 3250 3251 => setenv bootargs root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2 3252 3253 => printenv bootargs 3254 bootargs=root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2 3255 3256 => bootm 40020000 3257 ## Booting Linux kernel at 40020000 ... 3258 Image Name: 2.2.13 for NFS on TQM850L 3259 Image Type: PowerPC Linux Kernel Image (gzip compressed) 3260 Data Size: 381681 Bytes = 372 kB = 0 MB 3261 Load Address: 00000000 3262 Entry Point: 0000000c 3263 Verifying Checksum ... OK 3264 Uncompressing Kernel Image ... OK 3265 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 3266 Boot arguments: root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2 3267 time_init: decrementer frequency = 187500000/60 3268 Calibrating delay loop... 49.77 BogoMIPS 3269 Memory: 15208k available (700k kernel code, 444k data, 32k init) [c0000000,c1000000] 3270 ... 3271 3272If you want to boot a Linux kernel with initial ram disk, you pass 3273the memory addresses of both the kernel and the initrd image (PPBCOOT 3274format!) to the "bootm" command: 3275 3276 => imi 40100000 40200000 3277 3278 ## Checking Image at 40100000 ... 3279 Image Name: 2.2.13 for initrd on TQM850L 3280 Image Type: PowerPC Linux Kernel Image (gzip compressed) 3281 Data Size: 335725 Bytes = 327 kB = 0 MB 3282 Load Address: 00000000 3283 Entry Point: 0000000c 3284 Verifying Checksum ... OK 3285 3286 ## Checking Image at 40200000 ... 3287 Image Name: Simple Ramdisk Image 3288 Image Type: PowerPC Linux RAMDisk Image (gzip compressed) 3289 Data Size: 566530 Bytes = 553 kB = 0 MB 3290 Load Address: 00000000 3291 Entry Point: 00000000 3292 Verifying Checksum ... OK 3293 3294 => bootm 40100000 40200000 3295 ## Booting Linux kernel at 40100000 ... 3296 Image Name: 2.2.13 for initrd on TQM850L 3297 Image Type: PowerPC Linux Kernel Image (gzip compressed) 3298 Data Size: 335725 Bytes = 327 kB = 0 MB 3299 Load Address: 00000000 3300 Entry Point: 0000000c 3301 Verifying Checksum ... OK 3302 Uncompressing Kernel Image ... OK 3303 ## Loading RAMDisk Image at 40200000 ... 3304 Image Name: Simple Ramdisk Image 3305 Image Type: PowerPC Linux RAMDisk Image (gzip compressed) 3306 Data Size: 566530 Bytes = 553 kB = 0 MB 3307 Load Address: 00000000 3308 Entry Point: 00000000 3309 Verifying Checksum ... OK 3310 Loading Ramdisk ... OK 3311 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 3312 Boot arguments: root=/dev/ram 3313 time_init: decrementer frequency = 187500000/60 3314 Calibrating delay loop... 49.77 BogoMIPS 3315 ... 3316 RAMDISK: Compressed image found at block 0 3317 VFS: Mounted root (ext2 filesystem). 3318 3319 bash# 3320 3321Boot Linux and pass a flat device tree: 3322----------- 3323 3324First, U-Boot must be compiled with the appropriate defines. See the section 3325titled "Linux Kernel Interface" above for a more in depth explanation. The 3326following is an example of how to start a kernel and pass an updated 3327flat device tree: 3328 3329=> print oftaddr 3330oftaddr=0x300000 3331=> print oft 3332oft=oftrees/mpc8540ads.dtb 3333=> tftp $oftaddr $oft 3334Speed: 1000, full duplex 3335Using TSEC0 device 3336TFTP from server 192.168.1.1; our IP address is 192.168.1.101 3337Filename 'oftrees/mpc8540ads.dtb'. 3338Load address: 0x300000 3339Loading: # 3340done 3341Bytes transferred = 4106 (100a hex) 3342=> tftp $loadaddr $bootfile 3343Speed: 1000, full duplex 3344Using TSEC0 device 3345TFTP from server 192.168.1.1; our IP address is 192.168.1.2 3346Filename 'uImage'. 3347Load address: 0x200000 3348Loading:############ 3349done 3350Bytes transferred = 1029407 (fb51f hex) 3351=> print loadaddr 3352loadaddr=200000 3353=> print oftaddr 3354oftaddr=0x300000 3355=> bootm $loadaddr - $oftaddr 3356## Booting image at 00200000 ... 3357 Image Name: Linux-2.6.17-dirty 3358 Image Type: PowerPC Linux Kernel Image (gzip compressed) 3359 Data Size: 1029343 Bytes = 1005.2 kB 3360 Load Address: 00000000 3361 Entry Point: 00000000 3362 Verifying Checksum ... OK 3363 Uncompressing Kernel Image ... OK 3364Booting using flat device tree at 0x300000 3365Using MPC85xx ADS machine description 3366Memory CAM mapping: CAM0=256Mb, CAM1=256Mb, CAM2=0Mb residual: 0Mb 3367[snip] 3368 3369 3370More About U-Boot Image Types: 3371------------------------------ 3372 3373U-Boot supports the following image types: 3374 3375 "Standalone Programs" are directly runnable in the environment 3376 provided by U-Boot; it is expected that (if they behave 3377 well) you can continue to work in U-Boot after return from 3378 the Standalone Program. 3379 "OS Kernel Images" are usually images of some Embedded OS which 3380 will take over control completely. Usually these programs 3381 will install their own set of exception handlers, device 3382 drivers, set up the MMU, etc. - this means, that you cannot 3383 expect to re-enter U-Boot except by resetting the CPU. 3384 "RAMDisk Images" are more or less just data blocks, and their 3385 parameters (address, size) are passed to an OS kernel that is 3386 being started. 3387 "Multi-File Images" contain several images, typically an OS 3388 (Linux) kernel image and one or more data images like 3389 RAMDisks. This construct is useful for instance when you want 3390 to boot over the network using BOOTP etc., where the boot 3391 server provides just a single image file, but you want to get 3392 for instance an OS kernel and a RAMDisk image. 3393 3394 "Multi-File Images" start with a list of image sizes, each 3395 image size (in bytes) specified by an "uint32_t" in network 3396 byte order. This list is terminated by an "(uint32_t)0". 3397 Immediately after the terminating 0 follow the images, one by 3398 one, all aligned on "uint32_t" boundaries (size rounded up to 3399 a multiple of 4 bytes). 3400 3401 "Firmware Images" are binary images containing firmware (like 3402 U-Boot or FPGA images) which usually will be programmed to 3403 flash memory. 3404 3405 "Script files" are command sequences that will be executed by 3406 U-Boot's command interpreter; this feature is especially 3407 useful when you configure U-Boot to use a real shell (hush) 3408 as command interpreter. 3409 3410 3411Standalone HOWTO: 3412================= 3413 3414One of the features of U-Boot is that you can dynamically load and 3415run "standalone" applications, which can use some resources of 3416U-Boot like console I/O functions or interrupt services. 3417 3418Two simple examples are included with the sources: 3419 3420"Hello World" Demo: 3421------------------- 3422 3423'examples/hello_world.c' contains a small "Hello World" Demo 3424application; it is automatically compiled when you build U-Boot. 3425It's configured to run at address 0x00040004, so you can play with it 3426like that: 3427 3428 => loads 3429 ## Ready for S-Record download ... 3430 ~>examples/hello_world.srec 3431 1 2 3 4 5 6 7 8 9 10 11 ... 3432 [file transfer complete] 3433 [connected] 3434 ## Start Addr = 0x00040004 3435 3436 => go 40004 Hello World! This is a test. 3437 ## Starting application at 0x00040004 ... 3438 Hello World 3439 argc = 7 3440 argv[0] = "40004" 3441 argv[1] = "Hello" 3442 argv[2] = "World!" 3443 argv[3] = "This" 3444 argv[4] = "is" 3445 argv[5] = "a" 3446 argv[6] = "test." 3447 argv[7] = "<NULL>" 3448 Hit any key to exit ... 3449 3450 ## Application terminated, rc = 0x0 3451 3452Another example, which demonstrates how to register a CPM interrupt 3453handler with the U-Boot code, can be found in 'examples/timer.c'. 3454Here, a CPM timer is set up to generate an interrupt every second. 3455The interrupt service routine is trivial, just printing a '.' 3456character, but this is just a demo program. The application can be 3457controlled by the following keys: 3458 3459 ? - print current values og the CPM Timer registers 3460 b - enable interrupts and start timer 3461 e - stop timer and disable interrupts 3462 q - quit application 3463 3464 => loads 3465 ## Ready for S-Record download ... 3466 ~>examples/timer.srec 3467 1 2 3 4 5 6 7 8 9 10 11 ... 3468 [file transfer complete] 3469 [connected] 3470 ## Start Addr = 0x00040004 3471 3472 => go 40004 3473 ## Starting application at 0x00040004 ... 3474 TIMERS=0xfff00980 3475 Using timer 1 3476 tgcr @ 0xfff00980, tmr @ 0xfff00990, trr @ 0xfff00994, tcr @ 0xfff00998, tcn @ 0xfff0099c, ter @ 0xfff009b0 3477 3478Hit 'b': 3479 [q, b, e, ?] Set interval 1000000 us 3480 Enabling timer 3481Hit '?': 3482 [q, b, e, ?] ........ 3483 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0xef6, ter=0x0 3484Hit '?': 3485 [q, b, e, ?] . 3486 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x2ad4, ter=0x0 3487Hit '?': 3488 [q, b, e, ?] . 3489 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x1efc, ter=0x0 3490Hit '?': 3491 [q, b, e, ?] . 3492 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x169d, ter=0x0 3493Hit 'e': 3494 [q, b, e, ?] ...Stopping timer 3495Hit 'q': 3496 [q, b, e, ?] ## Application terminated, rc = 0x0 3497 3498 3499Minicom warning: 3500================ 3501 3502Over time, many people have reported problems when trying to use the 3503"minicom" terminal emulation program for serial download. I (wd) 3504consider minicom to be broken, and recommend not to use it. Under 3505Unix, I recommend to use C-Kermit for general purpose use (and 3506especially for kermit binary protocol download ("loadb" command), and 3507use "cu" for S-Record download ("loads" command). 3508 3509Nevertheless, if you absolutely want to use it try adding this 3510configuration to your "File transfer protocols" section: 3511 3512 Name Program Name U/D FullScr IO-Red. Multi 3513 X kermit /usr/bin/kermit -i -l %l -s Y U Y N N 3514 Y kermit /usr/bin/kermit -i -l %l -r N D Y N N 3515 3516 3517NetBSD Notes: 3518============= 3519 3520Starting at version 0.9.2, U-Boot supports NetBSD both as host 3521(build U-Boot) and target system (boots NetBSD/mpc8xx). 3522 3523Building requires a cross environment; it is known to work on 3524NetBSD/i386 with the cross-powerpc-netbsd-1.3 package (you will also 3525need gmake since the Makefiles are not compatible with BSD make). 3526Note that the cross-powerpc package does not install include files; 3527attempting to build U-Boot will fail because <machine/ansi.h> is 3528missing. This file has to be installed and patched manually: 3529 3530 # cd /usr/pkg/cross/powerpc-netbsd/include 3531 # mkdir powerpc 3532 # ln -s powerpc machine 3533 # cp /usr/src/sys/arch/powerpc/include/ansi.h powerpc/ansi.h 3534 # ${EDIT} powerpc/ansi.h ## must remove __va_list, _BSD_VA_LIST 3535 3536Native builds *don't* work due to incompatibilities between native 3537and U-Boot include files. 3538 3539Booting assumes that (the first part of) the image booted is a 3540stage-2 loader which in turn loads and then invokes the kernel 3541proper. Loader sources will eventually appear in the NetBSD source 3542tree (probably in sys/arc/mpc8xx/stand/u-boot_stage2/); in the 3543meantime, see ftp://ftp.denx.de/pub/u-boot/ppcboot_stage2.tar.gz 3544 3545 3546Implementation Internals: 3547========================= 3548 3549The following is not intended to be a complete description of every 3550implementation detail. However, it should help to understand the 3551inner workings of U-Boot and make it easier to port it to custom 3552hardware. 3553 3554 3555Initial Stack, Global Data: 3556--------------------------- 3557 3558The implementation of U-Boot is complicated by the fact that U-Boot 3559starts running out of ROM (flash memory), usually without access to 3560system RAM (because the memory controller is not initialized yet). 3561This means that we don't have writable Data or BSS segments, and BSS 3562is not initialized as zero. To be able to get a C environment working 3563at all, we have to allocate at least a minimal stack. Implementation 3564options for this are defined and restricted by the CPU used: Some CPU 3565models provide on-chip memory (like the IMMR area on MPC8xx and 3566MPC826x processors), on others (parts of) the data cache can be 3567locked as (mis-) used as memory, etc. 3568 3569 Chris Hallinan posted a good summary of these issues to the 3570 u-boot-users mailing list: 3571 3572 Subject: RE: [U-Boot-Users] RE: More On Memory Bank x (nothingness)? 3573 From: "Chris Hallinan" <clh@net1plus.com> 3574 Date: Mon, 10 Feb 2003 16:43:46 -0500 (22:43 MET) 3575 ... 3576 3577 Correct me if I'm wrong, folks, but the way I understand it 3578 is this: Using DCACHE as initial RAM for Stack, etc, does not 3579 require any physical RAM backing up the cache. The cleverness 3580 is that the cache is being used as a temporary supply of 3581 necessary storage before the SDRAM controller is setup. It's 3582 beyond the scope of this list to expain the details, but you 3583 can see how this works by studying the cache architecture and 3584 operation in the architecture and processor-specific manuals. 3585 3586 OCM is On Chip Memory, which I believe the 405GP has 4K. It 3587 is another option for the system designer to use as an 3588 initial stack/ram area prior to SDRAM being available. Either 3589 option should work for you. Using CS 4 should be fine if your 3590 board designers haven't used it for something that would 3591 cause you grief during the initial boot! It is frequently not 3592 used. 3593 3594 CFG_INIT_RAM_ADDR should be somewhere that won't interfere 3595 with your processor/board/system design. The default value 3596 you will find in any recent u-boot distribution in 3597 walnut.h should work for you. I'd set it to a value larger 3598 than your SDRAM module. If you have a 64MB SDRAM module, set 3599 it above 400_0000. Just make sure your board has no resources 3600 that are supposed to respond to that address! That code in 3601 start.S has been around a while and should work as is when 3602 you get the config right. 3603 3604 -Chris Hallinan 3605 DS4.COM, Inc. 3606 3607It is essential to remember this, since it has some impact on the C 3608code for the initialization procedures: 3609 3610* Initialized global data (data segment) is read-only. Do not attempt 3611 to write it. 3612 3613* Do not use any unitialized global data (or implicitely initialized 3614 as zero data - BSS segment) at all - this is undefined, initiali- 3615 zation is performed later (when relocating to RAM). 3616 3617* Stack space is very limited. Avoid big data buffers or things like 3618 that. 3619 3620Having only the stack as writable memory limits means we cannot use 3621normal global data to share information beween the code. But it 3622turned out that the implementation of U-Boot can be greatly 3623simplified by making a global data structure (gd_t) available to all 3624functions. We could pass a pointer to this data as argument to _all_ 3625functions, but this would bloat the code. Instead we use a feature of 3626the GCC compiler (Global Register Variables) to share the data: we 3627place a pointer (gd) to the global data into a register which we 3628reserve for this purpose. 3629 3630When choosing a register for such a purpose we are restricted by the 3631relevant (E)ABI specifications for the current architecture, and by 3632GCC's implementation. 3633 3634For PowerPC, the following registers have specific use: 3635 R1: stack pointer 3636 R2: reserved for system use 3637 R3-R4: parameter passing and return values 3638 R5-R10: parameter passing 3639 R13: small data area pointer 3640 R30: GOT pointer 3641 R31: frame pointer 3642 3643 (U-Boot also uses R14 as internal GOT pointer.) 3644 3645 ==> U-Boot will use R2 to hold a pointer to the global data 3646 3647 Note: on PPC, we could use a static initializer (since the 3648 address of the global data structure is known at compile time), 3649 but it turned out that reserving a register results in somewhat 3650 smaller code - although the code savings are not that big (on 3651 average for all boards 752 bytes for the whole U-Boot image, 3652 624 text + 127 data). 3653 3654On Blackfin, the normal C ABI (except for P5) is followed as documented here: 3655 http://docs.blackfin.uclinux.org/doku.php?id=application_binary_interface 3656 3657 ==> U-Boot will use P5 to hold a pointer to the global data 3658 3659On ARM, the following registers are used: 3660 3661 R0: function argument word/integer result 3662 R1-R3: function argument word 3663 R9: GOT pointer 3664 R10: stack limit (used only if stack checking if enabled) 3665 R11: argument (frame) pointer 3666 R12: temporary workspace 3667 R13: stack pointer 3668 R14: link register 3669 R15: program counter 3670 3671 ==> U-Boot will use R8 to hold a pointer to the global data 3672 3673NOTE: DECLARE_GLOBAL_DATA_PTR must be used with file-global scope, 3674or current versions of GCC may "optimize" the code too much. 3675 3676Memory Management: 3677------------------ 3678 3679U-Boot runs in system state and uses physical addresses, i.e. the 3680MMU is not used either for address mapping nor for memory protection. 3681 3682The available memory is mapped to fixed addresses using the memory 3683controller. In this process, a contiguous block is formed for each 3684memory type (Flash, SDRAM, SRAM), even when it consists of several 3685physical memory banks. 3686 3687U-Boot is installed in the first 128 kB of the first Flash bank (on 3688TQM8xxL modules this is the range 0x40000000 ... 0x4001FFFF). After 3689booting and sizing and initializing DRAM, the code relocates itself 3690to the upper end of DRAM. Immediately below the U-Boot code some 3691memory is reserved for use by malloc() [see CFG_MALLOC_LEN 3692configuration setting]. Below that, a structure with global Board 3693Info data is placed, followed by the stack (growing downward). 3694 3695Additionally, some exception handler code is copied to the low 8 kB 3696of DRAM (0x00000000 ... 0x00001FFF). 3697 3698So a typical memory configuration with 16 MB of DRAM could look like 3699this: 3700 3701 0x0000 0000 Exception Vector code 3702 : 3703 0x0000 1FFF 3704 0x0000 2000 Free for Application Use 3705 : 3706 : 3707 3708 : 3709 : 3710 0x00FB FF20 Monitor Stack (Growing downward) 3711 0x00FB FFAC Board Info Data and permanent copy of global data 3712 0x00FC 0000 Malloc Arena 3713 : 3714 0x00FD FFFF 3715 0x00FE 0000 RAM Copy of Monitor Code 3716 ... eventually: LCD or video framebuffer 3717 ... eventually: pRAM (Protected RAM - unchanged by reset) 3718 0x00FF FFFF [End of RAM] 3719 3720 3721System Initialization: 3722---------------------- 3723 3724In the reset configuration, U-Boot starts at the reset entry point 3725(on most PowerPC systens at address 0x00000100). Because of the reset 3726configuration for CS0# this is a mirror of the onboard Flash memory. 3727To be able to re-map memory U-Boot then jumps to its link address. 3728To be able to implement the initialization code in C, a (small!) 3729initial stack is set up in the internal Dual Ported RAM (in case CPUs 3730which provide such a feature like MPC8xx or MPC8260), or in a locked 3731part of the data cache. After that, U-Boot initializes the CPU core, 3732the caches and the SIU. 3733 3734Next, all (potentially) available memory banks are mapped using a 3735preliminary mapping. For example, we put them on 512 MB boundaries 3736(multiples of 0x20000000: SDRAM on 0x00000000 and 0x20000000, Flash 3737on 0x40000000 and 0x60000000, SRAM on 0x80000000). Then UPM A is 3738programmed for SDRAM access. Using the temporary configuration, a 3739simple memory test is run that determines the size of the SDRAM 3740banks. 3741 3742When there is more than one SDRAM bank, and the banks are of 3743different size, the largest is mapped first. For equal size, the first 3744bank (CS2#) is mapped first. The first mapping is always for address 37450x00000000, with any additional banks following immediately to create 3746contiguous memory starting from 0. 3747 3748Then, the monitor installs itself at the upper end of the SDRAM area 3749and allocates memory for use by malloc() and for the global Board 3750Info data; also, the exception vector code is copied to the low RAM 3751pages, and the final stack is set up. 3752 3753Only after this relocation will you have a "normal" C environment; 3754until that you are restricted in several ways, mostly because you are 3755running from ROM, and because the code will have to be relocated to a 3756new address in RAM. 3757 3758 3759U-Boot Porting Guide: 3760---------------------- 3761 3762[Based on messages by Jerry Van Baren in the U-Boot-Users mailing 3763list, October 2002] 3764 3765 3766int main (int argc, char *argv[]) 3767{ 3768 sighandler_t no_more_time; 3769 3770 signal (SIGALRM, no_more_time); 3771 alarm (PROJECT_DEADLINE - toSec (3 * WEEK)); 3772 3773 if (available_money > available_manpower) { 3774 pay consultant to port U-Boot; 3775 return 0; 3776 } 3777 3778 Download latest U-Boot source; 3779 3780 Subscribe to u-boot-users mailing list; 3781 3782 if (clueless) { 3783 email ("Hi, I am new to U-Boot, how do I get started?"); 3784 } 3785 3786 while (learning) { 3787 Read the README file in the top level directory; 3788 Read http://www.denx.de/twiki/bin/view/DULG/Manual ; 3789 Read the source, Luke; 3790 } 3791 3792 if (available_money > toLocalCurrency ($2500)) { 3793 Buy a BDI2000; 3794 } else { 3795 Add a lot of aggravation and time; 3796 } 3797 3798 Create your own board support subdirectory; 3799 3800 Create your own board config file; 3801 3802 while (!running) { 3803 do { 3804 Add / modify source code; 3805 } until (compiles); 3806 Debug; 3807 if (clueless) 3808 email ("Hi, I am having problems..."); 3809 } 3810 Send patch file to Wolfgang; 3811 3812 return 0; 3813} 3814 3815void no_more_time (int sig) 3816{ 3817 hire_a_guru(); 3818} 3819 3820 3821Coding Standards: 3822----------------- 3823 3824All contributions to U-Boot should conform to the Linux kernel 3825coding style; see the file "Documentation/CodingStyle" and the script 3826"scripts/Lindent" in your Linux kernel source directory. In sources 3827originating from U-Boot a style corresponding to "Lindent -pcs" (adding 3828spaces before parameters to function calls) is actually used. 3829 3830Source files originating from a different project (for example the 3831MTD subsystem) are generally exempt from these guidelines and are not 3832reformated to ease subsequent migration to newer versions of those 3833sources. 3834 3835Please note that U-Boot is implemented in C (and to some small parts in 3836Assembler); no C++ is used, so please do not use C++ style comments (//) 3837in your code. 3838 3839Please also stick to the following formatting rules: 3840- remove any trailing white space 3841- use TAB characters for indentation, not spaces 3842- make sure NOT to use DOS '\r\n' line feeds 3843- do not add more than 2 empty lines to source files 3844- do not add trailing empty lines to source files 3845 3846Submissions which do not conform to the standards may be returned 3847with a request to reformat the changes. 3848 3849 3850Submitting Patches: 3851------------------- 3852 3853Since the number of patches for U-Boot is growing, we need to 3854establish some rules. Submissions which do not conform to these rules 3855may be rejected, even when they contain important and valuable stuff. 3856 3857Patches shall be sent to the u-boot-users mailing list. 3858 3859Please see http://www.denx.de/wiki/UBoot/Patches for details. 3860 3861When you send a patch, please include the following information with 3862it: 3863 3864* For bug fixes: a description of the bug and how your patch fixes 3865 this bug. Please try to include a way of demonstrating that the 3866 patch actually fixes something. 3867 3868* For new features: a description of the feature and your 3869 implementation. 3870 3871* A CHANGELOG entry as plaintext (separate from the patch) 3872 3873* For major contributions, your entry to the CREDITS file 3874 3875* When you add support for a new board, don't forget to add this 3876 board to the MAKEALL script, too. 3877 3878* If your patch adds new configuration options, don't forget to 3879 document these in the README file. 3880 3881* The patch itself. If you are using git (which is *strongly* 3882 recommended) you can easily generate the patch using the 3883 "git-format-patch". If you then use "git-send-email" to send it to 3884 the U-Boot mailing list, you will avoid most of the common problems 3885 with some other mail clients. 3886 3887 If you cannot use git, use "diff -purN OLD NEW". If your version of 3888 diff does not support these options, then get the latest version of 3889 GNU diff. 3890 3891 The current directory when running this command shall be the parent 3892 directory of the U-Boot source tree (i. e. please make sure that 3893 your patch includes sufficient directory information for the 3894 affected files). 3895 3896 We prefer patches as plain text. MIME attachments are discouraged, 3897 and compressed attachments must not be used. 3898 3899* If one logical set of modifications affects or creates several 3900 files, all these changes shall be submitted in a SINGLE patch file. 3901 3902* Changesets that contain different, unrelated modifications shall be 3903 submitted as SEPARATE patches, one patch per changeset. 3904 3905 3906Notes: 3907 3908* Before sending the patch, run the MAKEALL script on your patched 3909 source tree and make sure that no errors or warnings are reported 3910 for any of the boards. 3911 3912* Keep your modifications to the necessary minimum: A patch 3913 containing several unrelated changes or arbitrary reformats will be 3914 returned with a request to re-formatting / split it. 3915 3916* If you modify existing code, make sure that your new code does not 3917 add to the memory footprint of the code ;-) Small is beautiful! 3918 When adding new features, these should compile conditionally only 3919 (using #ifdef), and the resulting code with the new feature 3920 disabled must not need more memory than the old code without your 3921 modification. 3922 3923* Remember that there is a size limit of 40 kB per message on the 3924 u-boot-users mailing list. Bigger patches will be moderated. If 3925 they are reasonable and not bigger than 100 kB, they will be 3926 acknowledged. Even bigger patches should be avoided. 3927