1# 2# (C) Copyright 2000 - 2008 3# Wolfgang Denk, DENX Software Engineering, wd@denx.de. 4# 5# See file CREDITS for list of people who contributed to this 6# project. 7# 8# This program is free software; you can redistribute it and/or 9# modify it under the terms of the GNU General Public License as 10# published by the Free Software Foundation; either version 2 of 11# the License, or (at your option) any later version. 12# 13# This program is distributed in the hope that it will be useful, 14# but WITHOUT ANY WARRANTY; without even the implied warranty of 15# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 16# GNU General Public License for more details. 17# 18# You should have received a copy of the GNU General Public License 19# along with this program; if not, write to the Free Software 20# Foundation, Inc., 59 Temple Place, Suite 330, Boston, 21# MA 02111-1307 USA 22# 23 24Summary: 25======== 26 27This directory contains the source code for U-Boot, a boot loader for 28Embedded boards based on PowerPC, ARM, MIPS and several other 29processors, which can be installed in a boot ROM and used to 30initialize and test the hardware or to download and run application 31code. 32 33The development of U-Boot is closely related to Linux: some parts of 34the source code originate in the Linux source tree, we have some 35header files in common, and special provision has been made to 36support booting of Linux images. 37 38Some attention has been paid to make this software easily 39configurable and extendable. For instance, all monitor commands are 40implemented with the same call interface, so that it's very easy to 41add new commands. Also, instead of permanently adding rarely used 42code (for instance hardware test utilities) to the monitor, you can 43load and run it dynamically. 44 45 46Status: 47======= 48 49In general, all boards for which a configuration option exists in the 50Makefile have been tested to some extent and can be considered 51"working". In fact, many of them are used in production systems. 52 53In case of problems see the CHANGELOG and CREDITS files to find out 54who contributed the specific port. The MAINTAINERS file lists board 55maintainers. 56 57 58Where to get help: 59================== 60 61In case you have questions about, problems with or contributions for 62U-Boot you should send a message to the U-Boot mailing list at 63<u-boot-users@lists.sourceforge.net>. There is also an archive of 64previous traffic on the mailing list - please search the archive 65before asking FAQ's. Please see 66http://lists.sourceforge.net/lists/listinfo/u-boot-users/ 67 68 69Where to get source code: 70========================= 71 72The U-Boot source code is maintained in the git repository at 73git://www.denx.de/git/u-boot.git ; you can browse it online at 74http://www.denx.de/cgi-bin/gitweb.cgi?p=u-boot.git;a=summary 75 76The "snapshot" links on this page allow you to download tarballs of 77any version you might be interested in. Ofifcial releases are also 78available for FTP download from the ftp://ftp.denx.de/pub/u-boot/ 79directory. 80 81Pre-built (and tested) images are available from 82ftp://ftp.denx.de/pub/u-boot/images/ 83 84 85Where we come from: 86=================== 87 88- start from 8xxrom sources 89- create PPCBoot project (http://sourceforge.net/projects/ppcboot) 90- clean up code 91- make it easier to add custom boards 92- make it possible to add other [PowerPC] CPUs 93- extend functions, especially: 94 * Provide extended interface to Linux boot loader 95 * S-Record download 96 * network boot 97 * PCMCIA / CompactFLash / ATA disk / SCSI ... boot 98- create ARMBoot project (http://sourceforge.net/projects/armboot) 99- add other CPU families (starting with ARM) 100- create U-Boot project (http://sourceforge.net/projects/u-boot) 101- current project page: see http://www.denx.de/wiki/UBoot 102 103 104Names and Spelling: 105=================== 106 107The "official" name of this project is "Das U-Boot". The spelling 108"U-Boot" shall be used in all written text (documentation, comments 109in source files etc.). Example: 110 111 This is the README file for the U-Boot project. 112 113File names etc. shall be based on the string "u-boot". Examples: 114 115 include/asm-ppc/u-boot.h 116 117 #include <asm/u-boot.h> 118 119Variable names, preprocessor constants etc. shall be either based on 120the string "u_boot" or on "U_BOOT". Example: 121 122 U_BOOT_VERSION u_boot_logo 123 IH_OS_U_BOOT u_boot_hush_start 124 125 126Versioning: 127=========== 128 129U-Boot uses a 3 level version number containing a version, a 130sub-version, and a patchlevel: "U-Boot-2.34.5" means version "2", 131sub-version "34", and patchlevel "4". 132 133The patchlevel is used to indicate certain stages of development 134between released versions, i. e. officially released versions of 135U-Boot will always have a patchlevel of "0". 136 137 138Directory Hierarchy: 139==================== 140 141- board Board dependent files 142- common Misc architecture independent functions 143- cpu CPU specific files 144 - 74xx_7xx Files specific to Freescale MPC74xx and 7xx CPUs 145 - arm720t Files specific to ARM 720 CPUs 146 - arm920t Files specific to ARM 920 CPUs 147 - at91rm9200 Files specific to Atmel AT91RM9200 CPU 148 - imx Files specific to Freescale MC9328 i.MX CPUs 149 - s3c24x0 Files specific to Samsung S3C24X0 CPUs 150 - arm925t Files specific to ARM 925 CPUs 151 - arm926ejs Files specific to ARM 926 CPUs 152 - arm1136 Files specific to ARM 1136 CPUs 153 - at32ap Files specific to Atmel AVR32 AP CPUs 154 - i386 Files specific to i386 CPUs 155 - ixp Files specific to Intel XScale IXP CPUs 156 - mcf52x2 Files specific to Freescale ColdFire MCF52x2 CPUs 157 - mcf5227x Files specific to Freescale ColdFire MCF5227x CPUs 158 - mcf532x Files specific to Freescale ColdFire MCF5329 CPUs 159 - mcf5445x Files specific to Freescale ColdFire MCF5445x CPUs 160 - mcf547x_8x Files specific to Freescale ColdFire MCF547x_8x CPUs 161 - mips Files specific to MIPS CPUs 162 - mpc5xx Files specific to Freescale MPC5xx CPUs 163 - mpc5xxx Files specific to Freescale MPC5xxx CPUs 164 - mpc8xx Files specific to Freescale MPC8xx CPUs 165 - mpc8220 Files specific to Freescale MPC8220 CPUs 166 - mpc824x Files specific to Freescale MPC824x CPUs 167 - mpc8260 Files specific to Freescale MPC8260 CPUs 168 - mpc85xx Files specific to Freescale MPC85xx CPUs 169 - nios Files specific to Altera NIOS CPUs 170 - nios2 Files specific to Altera Nios-II CPUs 171 - ppc4xx Files specific to AMCC PowerPC 4xx CPUs 172 - pxa Files specific to Intel XScale PXA CPUs 173 - s3c44b0 Files specific to Samsung S3C44B0 CPUs 174 - sa1100 Files specific to Intel StrongARM SA1100 CPUs 175- disk Code for disk drive partition handling 176- doc Documentation (don't expect too much) 177- drivers Commonly used device drivers 178- dtt Digital Thermometer and Thermostat drivers 179- examples Example code for standalone applications, etc. 180- include Header Files 181- lib_arm Files generic to ARM architecture 182- lib_avr32 Files generic to AVR32 architecture 183- lib_generic Files generic to all architectures 184- lib_i386 Files generic to i386 architecture 185- lib_m68k Files generic to m68k architecture 186- lib_mips Files generic to MIPS architecture 187- lib_nios Files generic to NIOS architecture 188- lib_ppc Files generic to PowerPC architecture 189- lib_sparc Files generic to SPARC architecture 190- libfdt Library files to support flattened device trees 191- net Networking code 192- post Power On Self Test 193- rtc Real Time Clock drivers 194- tools Tools to build S-Record or U-Boot images, etc. 195 196Software Configuration: 197======================= 198 199Configuration is usually done using C preprocessor defines; the 200rationale behind that is to avoid dead code whenever possible. 201 202There are two classes of configuration variables: 203 204* Configuration _OPTIONS_: 205 These are selectable by the user and have names beginning with 206 "CONFIG_". 207 208* Configuration _SETTINGS_: 209 These depend on the hardware etc. and should not be meddled with if 210 you don't know what you're doing; they have names beginning with 211 "CFG_". 212 213Later we will add a configuration tool - probably similar to or even 214identical to what's used for the Linux kernel. Right now, we have to 215do the configuration by hand, which means creating some symbolic 216links and editing some configuration files. We use the TQM8xxL boards 217as an example here. 218 219 220Selection of Processor Architecture and Board Type: 221--------------------------------------------------- 222 223For all supported boards there are ready-to-use default 224configurations available; just type "make <board_name>_config". 225 226Example: For a TQM823L module type: 227 228 cd u-boot 229 make TQM823L_config 230 231For the Cogent platform, you need to specify the cpu type as well; 232e.g. "make cogent_mpc8xx_config". And also configure the cogent 233directory according to the instructions in cogent/README. 234 235 236Configuration Options: 237---------------------- 238 239Configuration depends on the combination of board and CPU type; all 240such information is kept in a configuration file 241"include/configs/<board_name>.h". 242 243Example: For a TQM823L module, all configuration settings are in 244"include/configs/TQM823L.h". 245 246 247Many of the options are named exactly as the corresponding Linux 248kernel configuration options. The intention is to make it easier to 249build a config tool - later. 250 251 252The following options need to be configured: 253 254- CPU Type: Define exactly one, e.g. CONFIG_MPC85XX. 255 256- Board Type: Define exactly one, e.g. CONFIG_MPC8540ADS. 257 258- CPU Daughterboard Type: (if CONFIG_ATSTK1000 is defined) 259 Define exactly one, e.g. CONFIG_ATSTK1002 260 261- CPU Module Type: (if CONFIG_COGENT is defined) 262 Define exactly one of 263 CONFIG_CMA286_60_OLD 264--- FIXME --- not tested yet: 265 CONFIG_CMA286_60, CONFIG_CMA286_21, CONFIG_CMA286_60P, 266 CONFIG_CMA287_23, CONFIG_CMA287_50 267 268- Motherboard Type: (if CONFIG_COGENT is defined) 269 Define exactly one of 270 CONFIG_CMA101, CONFIG_CMA102 271 272- Motherboard I/O Modules: (if CONFIG_COGENT is defined) 273 Define one or more of 274 CONFIG_CMA302 275 276- Motherboard Options: (if CONFIG_CMA101 or CONFIG_CMA102 are defined) 277 Define one or more of 278 CONFIG_LCD_HEARTBEAT - update a character position on 279 the lcd display every second with 280 a "rotator" |\-/|\-/ 281 282- Board flavour: (if CONFIG_MPC8260ADS is defined) 283 CONFIG_ADSTYPE 284 Possible values are: 285 CFG_8260ADS - original MPC8260ADS 286 CFG_8266ADS - MPC8266ADS 287 CFG_PQ2FADS - PQ2FADS-ZU or PQ2FADS-VR 288 CFG_8272ADS - MPC8272ADS 289 290- MPC824X Family Member (if CONFIG_MPC824X is defined) 291 Define exactly one of 292 CONFIG_MPC8240, CONFIG_MPC8245 293 294- 8xx CPU Options: (if using an MPC8xx cpu) 295 CONFIG_8xx_GCLK_FREQ - deprecated: CPU clock if 296 get_gclk_freq() cannot work 297 e.g. if there is no 32KHz 298 reference PIT/RTC clock 299 CONFIG_8xx_OSCLK - PLL input clock (either EXTCLK 300 or XTAL/EXTAL) 301 302- 859/866/885 CPU options: (if using a MPC859 or MPC866 or MPC885 CPU): 303 CFG_8xx_CPUCLK_MIN 304 CFG_8xx_CPUCLK_MAX 305 CONFIG_8xx_CPUCLK_DEFAULT 306 See doc/README.MPC866 307 308 CFG_MEASURE_CPUCLK 309 310 Define this to measure the actual CPU clock instead 311 of relying on the correctness of the configured 312 values. Mostly useful for board bringup to make sure 313 the PLL is locked at the intended frequency. Note 314 that this requires a (stable) reference clock (32 kHz 315 RTC clock or CFG_8XX_XIN) 316 317- Intel Monahans options: 318 CFG_MONAHANS_RUN_MODE_OSC_RATIO 319 320 Defines the Monahans run mode to oscillator 321 ratio. Valid values are 8, 16, 24, 31. The core 322 frequency is this value multiplied by 13 MHz. 323 324 CFG_MONAHANS_TURBO_RUN_MODE_RATIO 325 326 Defines the Monahans turbo mode to oscillator 327 ratio. Valid values are 1 (default if undefined) and 328 2. The core frequency as calculated above is multiplied 329 by this value. 330 331- Linux Kernel Interface: 332 CONFIG_CLOCKS_IN_MHZ 333 334 U-Boot stores all clock information in Hz 335 internally. For binary compatibility with older Linux 336 kernels (which expect the clocks passed in the 337 bd_info data to be in MHz) the environment variable 338 "clocks_in_mhz" can be defined so that U-Boot 339 converts clock data to MHZ before passing it to the 340 Linux kernel. 341 When CONFIG_CLOCKS_IN_MHZ is defined, a definition of 342 "clocks_in_mhz=1" is automatically included in the 343 default environment. 344 345 CONFIG_MEMSIZE_IN_BYTES [relevant for MIPS only] 346 347 When transfering memsize parameter to linux, some versions 348 expect it to be in bytes, others in MB. 349 Define CONFIG_MEMSIZE_IN_BYTES to make it in bytes. 350 351 CONFIG_OF_LIBFDT / CONFIG_OF_FLAT_TREE 352 353 New kernel versions are expecting firmware settings to be 354 passed using flattened device trees (based on open firmware 355 concepts). 356 357 CONFIG_OF_LIBFDT 358 * New libfdt-based support 359 * Adds the "fdt" command 360 * The bootm command automatically updates the fdt 361 362 CONFIG_OF_FLAT_TREE 363 * Deprecated, see CONFIG_OF_LIBFDT 364 * Original ft_build.c-based support 365 * Automatically modifies the dft as part of the bootm command 366 * The environment variable "disable_of", when set, 367 disables this functionality. 368 369 OF_CPU - The proper name of the cpus node. 370 OF_SOC - The proper name of the soc node. 371 OF_TBCLK - The timebase frequency. 372 OF_STDOUT_PATH - The path to the console device 373 374 boards with QUICC Engines require OF_QE to set UCC mac addresses 375 376 CONFIG_OF_BOARD_SETUP 377 378 Board code has addition modification that it wants to make 379 to the flat device tree before handing it off to the kernel 380 381 CONFIG_OF_BOOT_CPU 382 383 This define fills in the correct boot cpu in the boot 384 param header, the default value is zero if undefined. 385 386- Serial Ports: 387 CFG_PL010_SERIAL 388 389 Define this if you want support for Amba PrimeCell PL010 UARTs. 390 391 CFG_PL011_SERIAL 392 393 Define this if you want support for Amba PrimeCell PL011 UARTs. 394 395 CONFIG_PL011_CLOCK 396 397 If you have Amba PrimeCell PL011 UARTs, set this variable to 398 the clock speed of the UARTs. 399 400 CONFIG_PL01x_PORTS 401 402 If you have Amba PrimeCell PL010 or PL011 UARTs on your board, 403 define this to a list of base addresses for each (supported) 404 port. See e.g. include/configs/versatile.h 405 406 407- Console Interface: 408 Depending on board, define exactly one serial port 409 (like CONFIG_8xx_CONS_SMC1, CONFIG_8xx_CONS_SMC2, 410 CONFIG_8xx_CONS_SCC1, ...), or switch off the serial 411 console by defining CONFIG_8xx_CONS_NONE 412 413 Note: if CONFIG_8xx_CONS_NONE is defined, the serial 414 port routines must be defined elsewhere 415 (i.e. serial_init(), serial_getc(), ...) 416 417 CONFIG_CFB_CONSOLE 418 Enables console device for a color framebuffer. Needs following 419 defines (cf. smiLynxEM, i8042, board/eltec/bab7xx) 420 VIDEO_FB_LITTLE_ENDIAN graphic memory organisation 421 (default big endian) 422 VIDEO_HW_RECTFILL graphic chip supports 423 rectangle fill 424 (cf. smiLynxEM) 425 VIDEO_HW_BITBLT graphic chip supports 426 bit-blit (cf. smiLynxEM) 427 VIDEO_VISIBLE_COLS visible pixel columns 428 (cols=pitch) 429 VIDEO_VISIBLE_ROWS visible pixel rows 430 VIDEO_PIXEL_SIZE bytes per pixel 431 VIDEO_DATA_FORMAT graphic data format 432 (0-5, cf. cfb_console.c) 433 VIDEO_FB_ADRS framebuffer address 434 VIDEO_KBD_INIT_FCT keyboard int fct 435 (i.e. i8042_kbd_init()) 436 VIDEO_TSTC_FCT test char fct 437 (i.e. i8042_tstc) 438 VIDEO_GETC_FCT get char fct 439 (i.e. i8042_getc) 440 CONFIG_CONSOLE_CURSOR cursor drawing on/off 441 (requires blink timer 442 cf. i8042.c) 443 CFG_CONSOLE_BLINK_COUNT blink interval (cf. i8042.c) 444 CONFIG_CONSOLE_TIME display time/date info in 445 upper right corner 446 (requires CONFIG_CMD_DATE) 447 CONFIG_VIDEO_LOGO display Linux logo in 448 upper left corner 449 CONFIG_VIDEO_BMP_LOGO use bmp_logo.h instead of 450 linux_logo.h for logo. 451 Requires CONFIG_VIDEO_LOGO 452 CONFIG_CONSOLE_EXTRA_INFO 453 addional board info beside 454 the logo 455 456 When CONFIG_CFB_CONSOLE is defined, video console is 457 default i/o. Serial console can be forced with 458 environment 'console=serial'. 459 460 When CONFIG_SILENT_CONSOLE is defined, all console 461 messages (by U-Boot and Linux!) can be silenced with 462 the "silent" environment variable. See 463 doc/README.silent for more information. 464 465- Console Baudrate: 466 CONFIG_BAUDRATE - in bps 467 Select one of the baudrates listed in 468 CFG_BAUDRATE_TABLE, see below. 469 CFG_BRGCLK_PRESCALE, baudrate prescale 470 471- Interrupt driven serial port input: 472 CONFIG_SERIAL_SOFTWARE_FIFO 473 474 PPC405GP only. 475 Use an interrupt handler for receiving data on the 476 serial port. It also enables using hardware handshake 477 (RTS/CTS) and UART's built-in FIFO. Set the number of 478 bytes the interrupt driven input buffer should have. 479 480 Leave undefined to disable this feature, including 481 disable the buffer and hardware handshake. 482 483- Console UART Number: 484 CONFIG_UART1_CONSOLE 485 486 AMCC PPC4xx only. 487 If defined internal UART1 (and not UART0) is used 488 as default U-Boot console. 489 490- Boot Delay: CONFIG_BOOTDELAY - in seconds 491 Delay before automatically booting the default image; 492 set to -1 to disable autoboot. 493 494 See doc/README.autoboot for these options that 495 work with CONFIG_BOOTDELAY. None are required. 496 CONFIG_BOOT_RETRY_TIME 497 CONFIG_BOOT_RETRY_MIN 498 CONFIG_AUTOBOOT_KEYED 499 CONFIG_AUTOBOOT_PROMPT 500 CONFIG_AUTOBOOT_DELAY_STR 501 CONFIG_AUTOBOOT_STOP_STR 502 CONFIG_AUTOBOOT_DELAY_STR2 503 CONFIG_AUTOBOOT_STOP_STR2 504 CONFIG_ZERO_BOOTDELAY_CHECK 505 CONFIG_RESET_TO_RETRY 506 507- Autoboot Command: 508 CONFIG_BOOTCOMMAND 509 Only needed when CONFIG_BOOTDELAY is enabled; 510 define a command string that is automatically executed 511 when no character is read on the console interface 512 within "Boot Delay" after reset. 513 514 CONFIG_BOOTARGS 515 This can be used to pass arguments to the bootm 516 command. The value of CONFIG_BOOTARGS goes into the 517 environment value "bootargs". 518 519 CONFIG_RAMBOOT and CONFIG_NFSBOOT 520 The value of these goes into the environment as 521 "ramboot" and "nfsboot" respectively, and can be used 522 as a convenience, when switching between booting from 523 ram and nfs. 524 525- Pre-Boot Commands: 526 CONFIG_PREBOOT 527 528 When this option is #defined, the existence of the 529 environment variable "preboot" will be checked 530 immediately before starting the CONFIG_BOOTDELAY 531 countdown and/or running the auto-boot command resp. 532 entering interactive mode. 533 534 This feature is especially useful when "preboot" is 535 automatically generated or modified. For an example 536 see the LWMON board specific code: here "preboot" is 537 modified when the user holds down a certain 538 combination of keys on the (special) keyboard when 539 booting the systems 540 541- Serial Download Echo Mode: 542 CONFIG_LOADS_ECHO 543 If defined to 1, all characters received during a 544 serial download (using the "loads" command) are 545 echoed back. This might be needed by some terminal 546 emulations (like "cu"), but may as well just take 547 time on others. This setting #define's the initial 548 value of the "loads_echo" environment variable. 549 550- Kgdb Serial Baudrate: (if CONFIG_CMD_KGDB is defined) 551 CONFIG_KGDB_BAUDRATE 552 Select one of the baudrates listed in 553 CFG_BAUDRATE_TABLE, see below. 554 555- Monitor Functions: 556 Monitor commands can be included or excluded 557 from the build by using the #include files 558 "config_cmd_all.h" and #undef'ing unwanted 559 commands, or using "config_cmd_default.h" 560 and augmenting with additional #define's 561 for wanted commands. 562 563 The default command configuration includes all commands 564 except those marked below with a "*". 565 566 CONFIG_CMD_ASKENV * ask for env variable 567 CONFIG_CMD_AUTOSCRIPT Autoscript Support 568 CONFIG_CMD_BDI bdinfo 569 CONFIG_CMD_BEDBUG * Include BedBug Debugger 570 CONFIG_CMD_BMP * BMP support 571 CONFIG_CMD_BSP * Board specific commands 572 CONFIG_CMD_BOOTD bootd 573 CONFIG_CMD_CACHE * icache, dcache 574 CONFIG_CMD_CONSOLE coninfo 575 CONFIG_CMD_DATE * support for RTC, date/time... 576 CONFIG_CMD_DHCP * DHCP support 577 CONFIG_CMD_DIAG * Diagnostics 578 CONFIG_CMD_DOC * Disk-On-Chip Support 579 CONFIG_CMD_DTT * Digital Therm and Thermostat 580 CONFIG_CMD_ECHO echo arguments 581 CONFIG_CMD_EEPROM * EEPROM read/write support 582 CONFIG_CMD_ELF * bootelf, bootvx 583 CONFIG_CMD_ENV saveenv 584 CONFIG_CMD_FDC * Floppy Disk Support 585 CONFIG_CMD_FAT * FAT partition support 586 CONFIG_CMD_FDOS * Dos diskette Support 587 CONFIG_CMD_FLASH flinfo, erase, protect 588 CONFIG_CMD_FPGA FPGA device initialization support 589 CONFIG_CMD_HWFLOW * RTS/CTS hw flow control 590 CONFIG_CMD_I2C * I2C serial bus support 591 CONFIG_CMD_IDE * IDE harddisk support 592 CONFIG_CMD_IMI iminfo 593 CONFIG_CMD_IMLS List all found images 594 CONFIG_CMD_IMMAP * IMMR dump support 595 CONFIG_CMD_IRQ * irqinfo 596 CONFIG_CMD_ITEST Integer/string test of 2 values 597 CONFIG_CMD_JFFS2 * JFFS2 Support 598 CONFIG_CMD_KGDB * kgdb 599 CONFIG_CMD_LOADB loadb 600 CONFIG_CMD_LOADS loads 601 CONFIG_CMD_MEMORY md, mm, nm, mw, cp, cmp, crc, base, 602 loop, loopw, mtest 603 CONFIG_CMD_MISC Misc functions like sleep etc 604 CONFIG_CMD_MMC * MMC memory mapped support 605 CONFIG_CMD_MII * MII utility commands 606 CONFIG_CMD_NAND * NAND support 607 CONFIG_CMD_NET bootp, tftpboot, rarpboot 608 CONFIG_CMD_PCI * pciinfo 609 CONFIG_CMD_PCMCIA * PCMCIA support 610 CONFIG_CMD_PING * send ICMP ECHO_REQUEST to network 611 host 612 CONFIG_CMD_PORTIO * Port I/O 613 CONFIG_CMD_REGINFO * Register dump 614 CONFIG_CMD_RUN run command in env variable 615 CONFIG_CMD_SAVES * save S record dump 616 CONFIG_CMD_SCSI * SCSI Support 617 CONFIG_CMD_SDRAM * print SDRAM configuration information 618 (requires CONFIG_CMD_I2C) 619 CONFIG_CMD_SETGETDCR Support for DCR Register access 620 (4xx only) 621 CONFIG_CMD_SPI * SPI serial bus support 622 CONFIG_CMD_USB * USB support 623 CONFIG_CMD_VFD * VFD support (TRAB) 624 CONFIG_CMD_BSP * Board SPecific functions 625 CONFIG_CMD_CDP * Cisco Discover Protocol support 626 CONFIG_CMD_FSL * Microblaze FSL support 627 628 629 EXAMPLE: If you want all functions except of network 630 support you can write: 631 632 #include "config_cmd_all.h" 633 #undef CONFIG_CMD_NET 634 635 Other Commands: 636 fdt (flattened device tree) command: CONFIG_OF_LIBFDT 637 638 Note: Don't enable the "icache" and "dcache" commands 639 (configuration option CONFIG_CMD_CACHE) unless you know 640 what you (and your U-Boot users) are doing. Data 641 cache cannot be enabled on systems like the 8xx or 642 8260 (where accesses to the IMMR region must be 643 uncached), and it cannot be disabled on all other 644 systems where we (mis-) use the data cache to hold an 645 initial stack and some data. 646 647 648 XXX - this list needs to get updated! 649 650- Watchdog: 651 CONFIG_WATCHDOG 652 If this variable is defined, it enables watchdog 653 support. There must be support in the platform specific 654 code for a watchdog. For the 8xx and 8260 CPUs, the 655 SIU Watchdog feature is enabled in the SYPCR 656 register. 657 658- U-Boot Version: 659 CONFIG_VERSION_VARIABLE 660 If this variable is defined, an environment variable 661 named "ver" is created by U-Boot showing the U-Boot 662 version as printed by the "version" command. 663 This variable is readonly. 664 665- Real-Time Clock: 666 667 When CONFIG_CMD_DATE is selected, the type of the RTC 668 has to be selected, too. Define exactly one of the 669 following options: 670 671 CONFIG_RTC_MPC8xx - use internal RTC of MPC8xx 672 CONFIG_RTC_PCF8563 - use Philips PCF8563 RTC 673 CONFIG_RTC_MC146818 - use MC146818 RTC 674 CONFIG_RTC_DS1307 - use Maxim, Inc. DS1307 RTC 675 CONFIG_RTC_DS1337 - use Maxim, Inc. DS1337 RTC 676 CONFIG_RTC_DS1338 - use Maxim, Inc. DS1338 RTC 677 CONFIG_RTC_DS164x - use Dallas DS164x RTC 678 CONFIG_RTC_ISL1208 - use Intersil ISL1208 RTC 679 CONFIG_RTC_MAX6900 - use Maxim, Inc. MAX6900 RTC 680 CFG_RTC_DS1337_NOOSC - Turn off the OSC output for DS1337 681 682 Note that if the RTC uses I2C, then the I2C interface 683 must also be configured. See I2C Support, below. 684 685- Timestamp Support: 686 687 When CONFIG_TIMESTAMP is selected, the timestamp 688 (date and time) of an image is printed by image 689 commands like bootm or iminfo. This option is 690 automatically enabled when you select CONFIG_CMD_DATE . 691 692- Partition Support: 693 CONFIG_MAC_PARTITION and/or CONFIG_DOS_PARTITION 694 and/or CONFIG_ISO_PARTITION 695 696 If IDE or SCSI support is enabled (CONFIG_CMD_IDE or 697 CONFIG_CMD_SCSI) you must configure support for at 698 least one partition type as well. 699 700- IDE Reset method: 701 CONFIG_IDE_RESET_ROUTINE - this is defined in several 702 board configurations files but used nowhere! 703 704 CONFIG_IDE_RESET - is this is defined, IDE Reset will 705 be performed by calling the function 706 ide_set_reset(int reset) 707 which has to be defined in a board specific file 708 709- ATAPI Support: 710 CONFIG_ATAPI 711 712 Set this to enable ATAPI support. 713 714- LBA48 Support 715 CONFIG_LBA48 716 717 Set this to enable support for disks larger than 137GB 718 Also look at CFG_64BIT_LBA ,CFG_64BIT_VSPRINTF and CFG_64BIT_STRTOUL 719 Whithout these , LBA48 support uses 32bit variables and will 'only' 720 support disks up to 2.1TB. 721 722 CFG_64BIT_LBA: 723 When enabled, makes the IDE subsystem use 64bit sector addresses. 724 Default is 32bit. 725 726- SCSI Support: 727 At the moment only there is only support for the 728 SYM53C8XX SCSI controller; define 729 CONFIG_SCSI_SYM53C8XX to enable it. 730 731 CFG_SCSI_MAX_LUN [8], CFG_SCSI_MAX_SCSI_ID [7] and 732 CFG_SCSI_MAX_DEVICE [CFG_SCSI_MAX_SCSI_ID * 733 CFG_SCSI_MAX_LUN] can be adjusted to define the 734 maximum numbers of LUNs, SCSI ID's and target 735 devices. 736 CFG_SCSI_SYM53C8XX_CCF to fix clock timing (80Mhz) 737 738- NETWORK Support (PCI): 739 CONFIG_E1000 740 Support for Intel 8254x gigabit chips. 741 742 CONFIG_E1000_FALLBACK_MAC 743 default MAC for empty eeprom after production. 744 745 CONFIG_EEPRO100 746 Support for Intel 82557/82559/82559ER chips. 747 Optional CONFIG_EEPRO100_SROM_WRITE enables eeprom 748 write routine for first time initialisation. 749 750 CONFIG_TULIP 751 Support for Digital 2114x chips. 752 Optional CONFIG_TULIP_SELECT_MEDIA for board specific 753 modem chip initialisation (KS8761/QS6611). 754 755 CONFIG_NATSEMI 756 Support for National dp83815 chips. 757 758 CONFIG_NS8382X 759 Support for National dp8382[01] gigabit chips. 760 761- NETWORK Support (other): 762 763 CONFIG_DRIVER_LAN91C96 764 Support for SMSC's LAN91C96 chips. 765 766 CONFIG_LAN91C96_BASE 767 Define this to hold the physical address 768 of the LAN91C96's I/O space 769 770 CONFIG_LAN91C96_USE_32_BIT 771 Define this to enable 32 bit addressing 772 773 CONFIG_DRIVER_SMC91111 774 Support for SMSC's LAN91C111 chip 775 776 CONFIG_SMC91111_BASE 777 Define this to hold the physical address 778 of the device (I/O space) 779 780 CONFIG_SMC_USE_32_BIT 781 Define this if data bus is 32 bits 782 783 CONFIG_SMC_USE_IOFUNCS 784 Define this to use i/o functions instead of macros 785 (some hardware wont work with macros) 786 787- USB Support: 788 At the moment only the UHCI host controller is 789 supported (PIP405, MIP405, MPC5200); define 790 CONFIG_USB_UHCI to enable it. 791 define CONFIG_USB_KEYBOARD to enable the USB Keyboard 792 and define CONFIG_USB_STORAGE to enable the USB 793 storage devices. 794 Note: 795 Supported are USB Keyboards and USB Floppy drives 796 (TEAC FD-05PUB). 797 MPC5200 USB requires additional defines: 798 CONFIG_USB_CLOCK 799 for 528 MHz Clock: 0x0001bbbb 800 CONFIG_USB_CONFIG 801 for differential drivers: 0x00001000 802 for single ended drivers: 0x00005000 803 CFG_USB_EVENT_POLL 804 May be defined to allow interrupt polling 805 instead of using asynchronous interrupts 806 807- USB Device: 808 Define the below if you wish to use the USB console. 809 Once firmware is rebuilt from a serial console issue the 810 command "setenv stdin usbtty; setenv stdout usbtty" and 811 attach your usb cable. The Unix command "dmesg" should print 812 it has found a new device. The environment variable usbtty 813 can be set to gserial or cdc_acm to enable your device to 814 appear to a USB host as a Linux gserial device or a 815 Common Device Class Abstract Control Model serial device. 816 If you select usbtty = gserial you should be able to enumerate 817 a Linux host by 818 # modprobe usbserial vendor=0xVendorID product=0xProductID 819 else if using cdc_acm, simply setting the environment 820 variable usbtty to be cdc_acm should suffice. The following 821 might be defined in YourBoardName.h 822 823 CONFIG_USB_DEVICE 824 Define this to build a UDC device 825 826 CONFIG_USB_TTY 827 Define this to have a tty type of device available to 828 talk to the UDC device 829 830 CFG_CONSOLE_IS_IN_ENV 831 Define this if you want stdin, stdout &/or stderr to 832 be set to usbtty. 833 834 mpc8xx: 835 CFG_USB_EXTC_CLK 0xBLAH 836 Derive USB clock from external clock "blah" 837 - CFG_USB_EXTC_CLK 0x02 838 839 CFG_USB_BRG_CLK 0xBLAH 840 Derive USB clock from brgclk 841 - CFG_USB_BRG_CLK 0x04 842 843 If you have a USB-IF assigned VendorID then you may wish to 844 define your own vendor specific values either in BoardName.h 845 or directly in usbd_vendor_info.h. If you don't define 846 CONFIG_USBD_MANUFACTURER, CONFIG_USBD_PRODUCT_NAME, 847 CONFIG_USBD_VENDORID and CONFIG_USBD_PRODUCTID, then U-Boot 848 should pretend to be a Linux device to it's target host. 849 850 CONFIG_USBD_MANUFACTURER 851 Define this string as the name of your company for 852 - CONFIG_USBD_MANUFACTURER "my company" 853 854 CONFIG_USBD_PRODUCT_NAME 855 Define this string as the name of your product 856 - CONFIG_USBD_PRODUCT_NAME "acme usb device" 857 858 CONFIG_USBD_VENDORID 859 Define this as your assigned Vendor ID from the USB 860 Implementors Forum. This *must* be a genuine Vendor ID 861 to avoid polluting the USB namespace. 862 - CONFIG_USBD_VENDORID 0xFFFF 863 864 CONFIG_USBD_PRODUCTID 865 Define this as the unique Product ID 866 for your device 867 - CONFIG_USBD_PRODUCTID 0xFFFF 868 869 870- MMC Support: 871 The MMC controller on the Intel PXA is supported. To 872 enable this define CONFIG_MMC. The MMC can be 873 accessed from the boot prompt by mapping the device 874 to physical memory similar to flash. Command line is 875 enabled with CONFIG_CMD_MMC. The MMC driver also works with 876 the FAT fs. This is enabled with CONFIG_CMD_FAT. 877 878- Journaling Flash filesystem support: 879 CONFIG_JFFS2_NAND, CONFIG_JFFS2_NAND_OFF, CONFIG_JFFS2_NAND_SIZE, 880 CONFIG_JFFS2_NAND_DEV 881 Define these for a default partition on a NAND device 882 883 CFG_JFFS2_FIRST_SECTOR, 884 CFG_JFFS2_FIRST_BANK, CFG_JFFS2_NUM_BANKS 885 Define these for a default partition on a NOR device 886 887 CFG_JFFS_CUSTOM_PART 888 Define this to create an own partition. You have to provide a 889 function struct part_info* jffs2_part_info(int part_num) 890 891 If you define only one JFFS2 partition you may also want to 892 #define CFG_JFFS_SINGLE_PART 1 893 to disable the command chpart. This is the default when you 894 have not defined a custom partition 895 896- Keyboard Support: 897 CONFIG_ISA_KEYBOARD 898 899 Define this to enable standard (PC-Style) keyboard 900 support 901 902 CONFIG_I8042_KBD 903 Standard PC keyboard driver with US (is default) and 904 GERMAN key layout (switch via environment 'keymap=de') support. 905 Export function i8042_kbd_init, i8042_tstc and i8042_getc 906 for cfb_console. Supports cursor blinking. 907 908- Video support: 909 CONFIG_VIDEO 910 911 Define this to enable video support (for output to 912 video). 913 914 CONFIG_VIDEO_CT69000 915 916 Enable Chips & Technologies 69000 Video chip 917 918 CONFIG_VIDEO_SMI_LYNXEM 919 Enable Silicon Motion SMI 712/710/810 Video chip. The 920 video output is selected via environment 'videoout' 921 (1 = LCD and 2 = CRT). If videoout is undefined, CRT is 922 assumed. 923 924 For the CT69000 and SMI_LYNXEM drivers, videomode is 925 selected via environment 'videomode'. Two diferent ways 926 are possible: 927 - "videomode=num" 'num' is a standard LiLo mode numbers. 928 Following standard modes are supported (* is default): 929 930 Colors 640x480 800x600 1024x768 1152x864 1280x1024 931 -------------+--------------------------------------------- 932 8 bits | 0x301* 0x303 0x305 0x161 0x307 933 15 bits | 0x310 0x313 0x316 0x162 0x319 934 16 bits | 0x311 0x314 0x317 0x163 0x31A 935 24 bits | 0x312 0x315 0x318 ? 0x31B 936 -------------+--------------------------------------------- 937 (i.e. setenv videomode 317; saveenv; reset;) 938 939 - "videomode=bootargs" all the video parameters are parsed 940 from the bootargs. (See drivers/video/videomodes.c) 941 942 943 CONFIG_VIDEO_SED13806 944 Enable Epson SED13806 driver. This driver supports 8bpp 945 and 16bpp modes defined by CONFIG_VIDEO_SED13806_8BPP 946 or CONFIG_VIDEO_SED13806_16BPP 947 948- Keyboard Support: 949 CONFIG_KEYBOARD 950 951 Define this to enable a custom keyboard support. 952 This simply calls drv_keyboard_init() which must be 953 defined in your board-specific files. 954 The only board using this so far is RBC823. 955 956- LCD Support: CONFIG_LCD 957 958 Define this to enable LCD support (for output to LCD 959 display); also select one of the supported displays 960 by defining one of these: 961 962 CONFIG_NEC_NL6448AC33: 963 964 NEC NL6448AC33-18. Active, color, single scan. 965 966 CONFIG_NEC_NL6448BC20 967 968 NEC NL6448BC20-08. 6.5", 640x480. 969 Active, color, single scan. 970 971 CONFIG_NEC_NL6448BC33_54 972 973 NEC NL6448BC33-54. 10.4", 640x480. 974 Active, color, single scan. 975 976 CONFIG_SHARP_16x9 977 978 Sharp 320x240. Active, color, single scan. 979 It isn't 16x9, and I am not sure what it is. 980 981 CONFIG_SHARP_LQ64D341 982 983 Sharp LQ64D341 display, 640x480. 984 Active, color, single scan. 985 986 CONFIG_HLD1045 987 988 HLD1045 display, 640x480. 989 Active, color, single scan. 990 991 CONFIG_OPTREX_BW 992 993 Optrex CBL50840-2 NF-FW 99 22 M5 994 or 995 Hitachi LMG6912RPFC-00T 996 or 997 Hitachi SP14Q002 998 999 320x240. Black & white. 1000 1001 Normally display is black on white background; define 1002 CFG_WHITE_ON_BLACK to get it inverted. 1003 1004- Splash Screen Support: CONFIG_SPLASH_SCREEN 1005 1006 If this option is set, the environment is checked for 1007 a variable "splashimage". If found, the usual display 1008 of logo, copyright and system information on the LCD 1009 is suppressed and the BMP image at the address 1010 specified in "splashimage" is loaded instead. The 1011 console is redirected to the "nulldev", too. This 1012 allows for a "silent" boot where a splash screen is 1013 loaded very quickly after power-on. 1014 1015- Gzip compressed BMP image support: CONFIG_VIDEO_BMP_GZIP 1016 1017 If this option is set, additionally to standard BMP 1018 images, gzipped BMP images can be displayed via the 1019 splashscreen support or the bmp command. 1020 1021- Compression support: 1022 CONFIG_BZIP2 1023 1024 If this option is set, support for bzip2 compressed 1025 images is included. If not, only uncompressed and gzip 1026 compressed images are supported. 1027 1028 NOTE: the bzip2 algorithm requires a lot of RAM, so 1029 the malloc area (as defined by CFG_MALLOC_LEN) should 1030 be at least 4MB. 1031 1032- MII/PHY support: 1033 CONFIG_PHY_ADDR 1034 1035 The address of PHY on MII bus. 1036 1037 CONFIG_PHY_CLOCK_FREQ (ppc4xx) 1038 1039 The clock frequency of the MII bus 1040 1041 CONFIG_PHY_GIGE 1042 1043 If this option is set, support for speed/duplex 1044 detection of Gigabit PHY is included. 1045 1046 CONFIG_PHY_RESET_DELAY 1047 1048 Some PHY like Intel LXT971A need extra delay after 1049 reset before any MII register access is possible. 1050 For such PHY, set this option to the usec delay 1051 required. (minimum 300usec for LXT971A) 1052 1053 CONFIG_PHY_CMD_DELAY (ppc4xx) 1054 1055 Some PHY like Intel LXT971A need extra delay after 1056 command issued before MII status register can be read 1057 1058- Ethernet address: 1059 CONFIG_ETHADDR 1060 CONFIG_ETH2ADDR 1061 CONFIG_ETH3ADDR 1062 1063 Define a default value for ethernet address to use 1064 for the respective ethernet interface, in case this 1065 is not determined automatically. 1066 1067- IP address: 1068 CONFIG_IPADDR 1069 1070 Define a default value for the IP address to use for 1071 the default ethernet interface, in case this is not 1072 determined through e.g. bootp. 1073 1074- Server IP address: 1075 CONFIG_SERVERIP 1076 1077 Defines a default value for theIP address of a TFTP 1078 server to contact when using the "tftboot" command. 1079 1080- Multicast TFTP Mode: 1081 CONFIG_MCAST_TFTP 1082 1083 Defines whether you want to support multicast TFTP as per 1084 rfc-2090; for example to work with atftp. Lets lots of targets 1085 tftp down the same boot image concurrently. Note: the ethernet 1086 driver in use must provide a function: mcast() to join/leave a 1087 multicast group. 1088 1089 CONFIG_BOOTP_RANDOM_DELAY 1090- BOOTP Recovery Mode: 1091 CONFIG_BOOTP_RANDOM_DELAY 1092 1093 If you have many targets in a network that try to 1094 boot using BOOTP, you may want to avoid that all 1095 systems send out BOOTP requests at precisely the same 1096 moment (which would happen for instance at recovery 1097 from a power failure, when all systems will try to 1098 boot, thus flooding the BOOTP server. Defining 1099 CONFIG_BOOTP_RANDOM_DELAY causes a random delay to be 1100 inserted before sending out BOOTP requests. The 1101 following delays are inserted then: 1102 1103 1st BOOTP request: delay 0 ... 1 sec 1104 2nd BOOTP request: delay 0 ... 2 sec 1105 3rd BOOTP request: delay 0 ... 4 sec 1106 4th and following 1107 BOOTP requests: delay 0 ... 8 sec 1108 1109- DHCP Advanced Options: 1110 You can fine tune the DHCP functionality by defining 1111 CONFIG_BOOTP_* symbols: 1112 1113 CONFIG_BOOTP_SUBNETMASK 1114 CONFIG_BOOTP_GATEWAY 1115 CONFIG_BOOTP_HOSTNAME 1116 CONFIG_BOOTP_NISDOMAIN 1117 CONFIG_BOOTP_BOOTPATH 1118 CONFIG_BOOTP_BOOTFILESIZE 1119 CONFIG_BOOTP_DNS 1120 CONFIG_BOOTP_DNS2 1121 CONFIG_BOOTP_SEND_HOSTNAME 1122 CONFIG_BOOTP_NTPSERVER 1123 CONFIG_BOOTP_TIMEOFFSET 1124 CONFIG_BOOTP_VENDOREX 1125 1126 CONFIG_BOOTP_SERVERIP - TFTP server will be the serverip 1127 environment variable, not the BOOTP server. 1128 1129 CONFIG_BOOTP_DNS2 - If a DHCP client requests the DNS 1130 serverip from a DHCP server, it is possible that more 1131 than one DNS serverip is offered to the client. 1132 If CONFIG_BOOTP_DNS2 is enabled, the secondary DNS 1133 serverip will be stored in the additional environment 1134 variable "dnsip2". The first DNS serverip is always 1135 stored in the variable "dnsip", when CONFIG_BOOTP_DNS 1136 is defined. 1137 1138 CONFIG_BOOTP_SEND_HOSTNAME - Some DHCP servers are capable 1139 to do a dynamic update of a DNS server. To do this, they 1140 need the hostname of the DHCP requester. 1141 If CONFIG_BOOTP_SEND_HOSTNAME is defined, the content 1142 of the "hostname" environment variable is passed as 1143 option 12 to the DHCP server. 1144 1145 CONFIG_BOOTP_DHCP_REQUEST_DELAY 1146 1147 A 32bit value in microseconds for a delay between 1148 receiving a "DHCP Offer" and sending the "DHCP Request". 1149 This fixes a problem with certain DHCP servers that don't 1150 respond 100% of the time to a "DHCP request". E.g. On an 1151 AT91RM9200 processor running at 180MHz, this delay needed 1152 to be *at least* 15,000 usec before a Windows Server 2003 1153 DHCP server would reply 100% of the time. I recommend at 1154 least 50,000 usec to be safe. The alternative is to hope 1155 that one of the retries will be successful but note that 1156 the DHCP timeout and retry process takes a longer than 1157 this delay. 1158 1159 - CDP Options: 1160 CONFIG_CDP_DEVICE_ID 1161 1162 The device id used in CDP trigger frames. 1163 1164 CONFIG_CDP_DEVICE_ID_PREFIX 1165 1166 A two character string which is prefixed to the MAC address 1167 of the device. 1168 1169 CONFIG_CDP_PORT_ID 1170 1171 A printf format string which contains the ascii name of 1172 the port. Normally is set to "eth%d" which sets 1173 eth0 for the first ethernet, eth1 for the second etc. 1174 1175 CONFIG_CDP_CAPABILITIES 1176 1177 A 32bit integer which indicates the device capabilities; 1178 0x00000010 for a normal host which does not forwards. 1179 1180 CONFIG_CDP_VERSION 1181 1182 An ascii string containing the version of the software. 1183 1184 CONFIG_CDP_PLATFORM 1185 1186 An ascii string containing the name of the platform. 1187 1188 CONFIG_CDP_TRIGGER 1189 1190 A 32bit integer sent on the trigger. 1191 1192 CONFIG_CDP_POWER_CONSUMPTION 1193 1194 A 16bit integer containing the power consumption of the 1195 device in .1 of milliwatts. 1196 1197 CONFIG_CDP_APPLIANCE_VLAN_TYPE 1198 1199 A byte containing the id of the VLAN. 1200 1201- Status LED: CONFIG_STATUS_LED 1202 1203 Several configurations allow to display the current 1204 status using a LED. For instance, the LED will blink 1205 fast while running U-Boot code, stop blinking as 1206 soon as a reply to a BOOTP request was received, and 1207 start blinking slow once the Linux kernel is running 1208 (supported by a status LED driver in the Linux 1209 kernel). Defining CONFIG_STATUS_LED enables this 1210 feature in U-Boot. 1211 1212- CAN Support: CONFIG_CAN_DRIVER 1213 1214 Defining CONFIG_CAN_DRIVER enables CAN driver support 1215 on those systems that support this (optional) 1216 feature, like the TQM8xxL modules. 1217 1218- I2C Support: CONFIG_HARD_I2C | CONFIG_SOFT_I2C 1219 1220 These enable I2C serial bus commands. Defining either of 1221 (but not both of) CONFIG_HARD_I2C or CONFIG_SOFT_I2C will 1222 include the appropriate I2C driver for the selected cpu. 1223 1224 This will allow you to use i2c commands at the u-boot 1225 command line (as long as you set CONFIG_CMD_I2C in 1226 CONFIG_COMMANDS) and communicate with i2c based realtime 1227 clock chips. See common/cmd_i2c.c for a description of the 1228 command line interface. 1229 1230 CONFIG_I2C_CMD_TREE is a recommended option that places 1231 all I2C commands under a single 'i2c' root command. The 1232 older 'imm', 'imd', 'iprobe' etc. commands are considered 1233 deprecated and may disappear in the future. 1234 1235 CONFIG_HARD_I2C selects a hardware I2C controller. 1236 1237 CONFIG_SOFT_I2C configures u-boot to use a software (aka 1238 bit-banging) driver instead of CPM or similar hardware 1239 support for I2C. 1240 1241 There are several other quantities that must also be 1242 defined when you define CONFIG_HARD_I2C or CONFIG_SOFT_I2C. 1243 1244 In both cases you will need to define CFG_I2C_SPEED 1245 to be the frequency (in Hz) at which you wish your i2c bus 1246 to run and CFG_I2C_SLAVE to be the address of this node (ie 1247 the cpu's i2c node address). 1248 1249 Now, the u-boot i2c code for the mpc8xx (cpu/mpc8xx/i2c.c) 1250 sets the cpu up as a master node and so its address should 1251 therefore be cleared to 0 (See, eg, MPC823e User's Manual 1252 p.16-473). So, set CFG_I2C_SLAVE to 0. 1253 1254 That's all that's required for CONFIG_HARD_I2C. 1255 1256 If you use the software i2c interface (CONFIG_SOFT_I2C) 1257 then the following macros need to be defined (examples are 1258 from include/configs/lwmon.h): 1259 1260 I2C_INIT 1261 1262 (Optional). Any commands necessary to enable the I2C 1263 controller or configure ports. 1264 1265 eg: #define I2C_INIT (immr->im_cpm.cp_pbdir |= PB_SCL) 1266 1267 I2C_PORT 1268 1269 (Only for MPC8260 CPU). The I/O port to use (the code 1270 assumes both bits are on the same port). Valid values 1271 are 0..3 for ports A..D. 1272 1273 I2C_ACTIVE 1274 1275 The code necessary to make the I2C data line active 1276 (driven). If the data line is open collector, this 1277 define can be null. 1278 1279 eg: #define I2C_ACTIVE (immr->im_cpm.cp_pbdir |= PB_SDA) 1280 1281 I2C_TRISTATE 1282 1283 The code necessary to make the I2C data line tri-stated 1284 (inactive). If the data line is open collector, this 1285 define can be null. 1286 1287 eg: #define I2C_TRISTATE (immr->im_cpm.cp_pbdir &= ~PB_SDA) 1288 1289 I2C_READ 1290 1291 Code that returns TRUE if the I2C data line is high, 1292 FALSE if it is low. 1293 1294 eg: #define I2C_READ ((immr->im_cpm.cp_pbdat & PB_SDA) != 0) 1295 1296 I2C_SDA(bit) 1297 1298 If <bit> is TRUE, sets the I2C data line high. If it 1299 is FALSE, it clears it (low). 1300 1301 eg: #define I2C_SDA(bit) \ 1302 if(bit) immr->im_cpm.cp_pbdat |= PB_SDA; \ 1303 else immr->im_cpm.cp_pbdat &= ~PB_SDA 1304 1305 I2C_SCL(bit) 1306 1307 If <bit> is TRUE, sets the I2C clock line high. If it 1308 is FALSE, it clears it (low). 1309 1310 eg: #define I2C_SCL(bit) \ 1311 if(bit) immr->im_cpm.cp_pbdat |= PB_SCL; \ 1312 else immr->im_cpm.cp_pbdat &= ~PB_SCL 1313 1314 I2C_DELAY 1315 1316 This delay is invoked four times per clock cycle so this 1317 controls the rate of data transfer. The data rate thus 1318 is 1 / (I2C_DELAY * 4). Often defined to be something 1319 like: 1320 1321 #define I2C_DELAY udelay(2) 1322 1323 CFG_I2C_INIT_BOARD 1324 1325 When a board is reset during an i2c bus transfer 1326 chips might think that the current transfer is still 1327 in progress. On some boards it is possible to access 1328 the i2c SCLK line directly, either by using the 1329 processor pin as a GPIO or by having a second pin 1330 connected to the bus. If this option is defined a 1331 custom i2c_init_board() routine in boards/xxx/board.c 1332 is run early in the boot sequence. 1333 1334 CONFIG_I2CFAST (PPC405GP|PPC405EP only) 1335 1336 This option enables configuration of bi_iic_fast[] flags 1337 in u-boot bd_info structure based on u-boot environment 1338 variable "i2cfast". (see also i2cfast) 1339 1340 CONFIG_I2C_MULTI_BUS 1341 1342 This option allows the use of multiple I2C buses, each of which 1343 must have a controller. At any point in time, only one bus is 1344 active. To switch to a different bus, use the 'i2c dev' command. 1345 Note that bus numbering is zero-based. 1346 1347 CFG_I2C_NOPROBES 1348 1349 This option specifies a list of I2C devices that will be skipped 1350 when the 'i2c probe' command is issued (or 'iprobe' using the legacy 1351 command). If CONFIG_I2C_MULTI_BUS is set, specify a list of bus-device 1352 pairs. Otherwise, specify a 1D array of device addresses 1353 1354 e.g. 1355 #undef CONFIG_I2C_MULTI_BUS 1356 #define CFG_I2C_NOPROBES {0x50,0x68} 1357 1358 will skip addresses 0x50 and 0x68 on a board with one I2C bus 1359 1360 #define CONFIG_I2C_MULTI_BUS 1361 #define CFG_I2C_MULTI_NOPROBES {{0,0x50},{0,0x68},{1,0x54}} 1362 1363 will skip addresses 0x50 and 0x68 on bus 0 and address 0x54 on bus 1 1364 1365 CFG_SPD_BUS_NUM 1366 1367 If defined, then this indicates the I2C bus number for DDR SPD. 1368 If not defined, then U-Boot assumes that SPD is on I2C bus 0. 1369 1370 CFG_RTC_BUS_NUM 1371 1372 If defined, then this indicates the I2C bus number for the RTC. 1373 If not defined, then U-Boot assumes that RTC is on I2C bus 0. 1374 1375 CFG_DTT_BUS_NUM 1376 1377 If defined, then this indicates the I2C bus number for the DTT. 1378 If not defined, then U-Boot assumes that DTT is on I2C bus 0. 1379 1380 CONFIG_FSL_I2C 1381 1382 Define this option if you want to use Freescale's I2C driver in 1383 drivers/i2c/fsl_i2c.c. 1384 1385 1386- SPI Support: CONFIG_SPI 1387 1388 Enables SPI driver (so far only tested with 1389 SPI EEPROM, also an instance works with Crystal A/D and 1390 D/As on the SACSng board) 1391 1392 CONFIG_SPI_X 1393 1394 Enables extended (16-bit) SPI EEPROM addressing. 1395 (symmetrical to CONFIG_I2C_X) 1396 1397 CONFIG_SOFT_SPI 1398 1399 Enables a software (bit-bang) SPI driver rather than 1400 using hardware support. This is a general purpose 1401 driver that only requires three general I/O port pins 1402 (two outputs, one input) to function. If this is 1403 defined, the board configuration must define several 1404 SPI configuration items (port pins to use, etc). For 1405 an example, see include/configs/sacsng.h. 1406 1407 CONFIG_HARD_SPI 1408 1409 Enables a hardware SPI driver for general-purpose reads 1410 and writes. As with CONFIG_SOFT_SPI, the board configuration 1411 must define a list of chip-select function pointers. 1412 Currently supported on some MPC8xxx processors. For an 1413 example, see include/configs/mpc8349emds.h. 1414 1415- FPGA Support: CONFIG_FPGA 1416 1417 Enables FPGA subsystem. 1418 1419 CONFIG_FPGA_<vendor> 1420 1421 Enables support for specific chip vendors. 1422 (ALTERA, XILINX) 1423 1424 CONFIG_FPGA_<family> 1425 1426 Enables support for FPGA family. 1427 (SPARTAN2, SPARTAN3, VIRTEX2, CYCLONE2, ACEX1K, ACEX) 1428 1429 CONFIG_FPGA_COUNT 1430 1431 Specify the number of FPGA devices to support. 1432 1433 CFG_FPGA_PROG_FEEDBACK 1434 1435 Enable printing of hash marks during FPGA configuration. 1436 1437 CFG_FPGA_CHECK_BUSY 1438 1439 Enable checks on FPGA configuration interface busy 1440 status by the configuration function. This option 1441 will require a board or device specific function to 1442 be written. 1443 1444 CONFIG_FPGA_DELAY 1445 1446 If defined, a function that provides delays in the FPGA 1447 configuration driver. 1448 1449 CFG_FPGA_CHECK_CTRLC 1450 Allow Control-C to interrupt FPGA configuration 1451 1452 CFG_FPGA_CHECK_ERROR 1453 1454 Check for configuration errors during FPGA bitfile 1455 loading. For example, abort during Virtex II 1456 configuration if the INIT_B line goes low (which 1457 indicated a CRC error). 1458 1459 CFG_FPGA_WAIT_INIT 1460 1461 Maximum time to wait for the INIT_B line to deassert 1462 after PROB_B has been deasserted during a Virtex II 1463 FPGA configuration sequence. The default time is 500 1464 mS. 1465 1466 CFG_FPGA_WAIT_BUSY 1467 1468 Maximum time to wait for BUSY to deassert during 1469 Virtex II FPGA configuration. The default is 5 mS. 1470 1471 CFG_FPGA_WAIT_CONFIG 1472 1473 Time to wait after FPGA configuration. The default is 1474 200 mS. 1475 1476- Configuration Management: 1477 CONFIG_IDENT_STRING 1478 1479 If defined, this string will be added to the U-Boot 1480 version information (U_BOOT_VERSION) 1481 1482- Vendor Parameter Protection: 1483 1484 U-Boot considers the values of the environment 1485 variables "serial#" (Board Serial Number) and 1486 "ethaddr" (Ethernet Address) to be parameters that 1487 are set once by the board vendor / manufacturer, and 1488 protects these variables from casual modification by 1489 the user. Once set, these variables are read-only, 1490 and write or delete attempts are rejected. You can 1491 change this behviour: 1492 1493 If CONFIG_ENV_OVERWRITE is #defined in your config 1494 file, the write protection for vendor parameters is 1495 completely disabled. Anybody can change or delete 1496 these parameters. 1497 1498 Alternatively, if you #define _both_ CONFIG_ETHADDR 1499 _and_ CONFIG_OVERWRITE_ETHADDR_ONCE, a default 1500 ethernet address is installed in the environment, 1501 which can be changed exactly ONCE by the user. [The 1502 serial# is unaffected by this, i. e. it remains 1503 read-only.] 1504 1505- Protected RAM: 1506 CONFIG_PRAM 1507 1508 Define this variable to enable the reservation of 1509 "protected RAM", i. e. RAM which is not overwritten 1510 by U-Boot. Define CONFIG_PRAM to hold the number of 1511 kB you want to reserve for pRAM. You can overwrite 1512 this default value by defining an environment 1513 variable "pram" to the number of kB you want to 1514 reserve. Note that the board info structure will 1515 still show the full amount of RAM. If pRAM is 1516 reserved, a new environment variable "mem" will 1517 automatically be defined to hold the amount of 1518 remaining RAM in a form that can be passed as boot 1519 argument to Linux, for instance like that: 1520 1521 setenv bootargs ... mem=\${mem} 1522 saveenv 1523 1524 This way you can tell Linux not to use this memory, 1525 either, which results in a memory region that will 1526 not be affected by reboots. 1527 1528 *WARNING* If your board configuration uses automatic 1529 detection of the RAM size, you must make sure that 1530 this memory test is non-destructive. So far, the 1531 following board configurations are known to be 1532 "pRAM-clean": 1533 1534 ETX094, IVMS8, IVML24, SPD8xx, TQM8xxL, 1535 HERMES, IP860, RPXlite, LWMON, LANTEC, 1536 PCU_E, FLAGADM, TQM8260 1537 1538- Error Recovery: 1539 CONFIG_PANIC_HANG 1540 1541 Define this variable to stop the system in case of a 1542 fatal error, so that you have to reset it manually. 1543 This is probably NOT a good idea for an embedded 1544 system where you want to system to reboot 1545 automatically as fast as possible, but it may be 1546 useful during development since you can try to debug 1547 the conditions that lead to the situation. 1548 1549 CONFIG_NET_RETRY_COUNT 1550 1551 This variable defines the number of retries for 1552 network operations like ARP, RARP, TFTP, or BOOTP 1553 before giving up the operation. If not defined, a 1554 default value of 5 is used. 1555 1556- Command Interpreter: 1557 CONFIG_AUTO_COMPLETE 1558 1559 Enable auto completion of commands using TAB. 1560 1561 Note that this feature has NOT been implemented yet 1562 for the "hush" shell. 1563 1564 1565 CFG_HUSH_PARSER 1566 1567 Define this variable to enable the "hush" shell (from 1568 Busybox) as command line interpreter, thus enabling 1569 powerful command line syntax like 1570 if...then...else...fi conditionals or `&&' and '||' 1571 constructs ("shell scripts"). 1572 1573 If undefined, you get the old, much simpler behaviour 1574 with a somewhat smaller memory footprint. 1575 1576 1577 CFG_PROMPT_HUSH_PS2 1578 1579 This defines the secondary prompt string, which is 1580 printed when the command interpreter needs more input 1581 to complete a command. Usually "> ". 1582 1583 Note: 1584 1585 In the current implementation, the local variables 1586 space and global environment variables space are 1587 separated. Local variables are those you define by 1588 simply typing `name=value'. To access a local 1589 variable later on, you have write `$name' or 1590 `${name}'; to execute the contents of a variable 1591 directly type `$name' at the command prompt. 1592 1593 Global environment variables are those you use 1594 setenv/printenv to work with. To run a command stored 1595 in such a variable, you need to use the run command, 1596 and you must not use the '$' sign to access them. 1597 1598 To store commands and special characters in a 1599 variable, please use double quotation marks 1600 surrounding the whole text of the variable, instead 1601 of the backslashes before semicolons and special 1602 symbols. 1603 1604- Commandline Editing and History: 1605 CONFIG_CMDLINE_EDITING 1606 1607 Enable editiong and History functions for interactive 1608 commandline input operations 1609 1610- Default Environment: 1611 CONFIG_EXTRA_ENV_SETTINGS 1612 1613 Define this to contain any number of null terminated 1614 strings (variable = value pairs) that will be part of 1615 the default environment compiled into the boot image. 1616 1617 For example, place something like this in your 1618 board's config file: 1619 1620 #define CONFIG_EXTRA_ENV_SETTINGS \ 1621 "myvar1=value1\0" \ 1622 "myvar2=value2\0" 1623 1624 Warning: This method is based on knowledge about the 1625 internal format how the environment is stored by the 1626 U-Boot code. This is NOT an official, exported 1627 interface! Although it is unlikely that this format 1628 will change soon, there is no guarantee either. 1629 You better know what you are doing here. 1630 1631 Note: overly (ab)use of the default environment is 1632 discouraged. Make sure to check other ways to preset 1633 the environment like the autoscript function or the 1634 boot command first. 1635 1636- DataFlash Support: 1637 CONFIG_HAS_DATAFLASH 1638 1639 Defining this option enables DataFlash features and 1640 allows to read/write in Dataflash via the standard 1641 commands cp, md... 1642 1643- SystemACE Support: 1644 CONFIG_SYSTEMACE 1645 1646 Adding this option adds support for Xilinx SystemACE 1647 chips attached via some sort of local bus. The address 1648 of the chip must alsh be defined in the 1649 CFG_SYSTEMACE_BASE macro. For example: 1650 1651 #define CONFIG_SYSTEMACE 1652 #define CFG_SYSTEMACE_BASE 0xf0000000 1653 1654 When SystemACE support is added, the "ace" device type 1655 becomes available to the fat commands, i.e. fatls. 1656 1657- TFTP Fixed UDP Port: 1658 CONFIG_TFTP_PORT 1659 1660 If this is defined, the environment variable tftpsrcp 1661 is used to supply the TFTP UDP source port value. 1662 If tftpsrcp isn't defined, the normal pseudo-random port 1663 number generator is used. 1664 1665 Also, the environment variable tftpdstp is used to supply 1666 the TFTP UDP destination port value. If tftpdstp isn't 1667 defined, the normal port 69 is used. 1668 1669 The purpose for tftpsrcp is to allow a TFTP server to 1670 blindly start the TFTP transfer using the pre-configured 1671 target IP address and UDP port. This has the effect of 1672 "punching through" the (Windows XP) firewall, allowing 1673 the remainder of the TFTP transfer to proceed normally. 1674 A better solution is to properly configure the firewall, 1675 but sometimes that is not allowed. 1676 1677- Show boot progress: 1678 CONFIG_SHOW_BOOT_PROGRESS 1679 1680 Defining this option allows to add some board- 1681 specific code (calling a user-provided function 1682 "show_boot_progress(int)") that enables you to show 1683 the system's boot progress on some display (for 1684 example, some LED's) on your board. At the moment, 1685 the following checkpoints are implemented: 1686 1687Legacy uImage format: 1688 1689 Arg Where When 1690 1 common/cmd_bootm.c before attempting to boot an image 1691 -1 common/cmd_bootm.c Image header has bad magic number 1692 2 common/cmd_bootm.c Image header has correct magic number 1693 -2 common/cmd_bootm.c Image header has bad checksum 1694 3 common/cmd_bootm.c Image header has correct checksum 1695 -3 common/cmd_bootm.c Image data has bad checksum 1696 4 common/cmd_bootm.c Image data has correct checksum 1697 -4 common/cmd_bootm.c Image is for unsupported architecture 1698 5 common/cmd_bootm.c Architecture check OK 1699 -5 common/cmd_bootm.c Wrong Image Type (not kernel, multi) 1700 6 common/cmd_bootm.c Image Type check OK 1701 -6 common/cmd_bootm.c gunzip uncompression error 1702 -7 common/cmd_bootm.c Unimplemented compression type 1703 7 common/cmd_bootm.c Uncompression OK 1704 8 common/cmd_bootm.c No uncompress/copy overwrite error 1705 -9 common/cmd_bootm.c Unsupported OS (not Linux, BSD, VxWorks, QNX) 1706 1707 9 common/image.c Start initial ramdisk verification 1708 -10 common/image.c Ramdisk header has bad magic number 1709 -11 common/image.c Ramdisk header has bad checksum 1710 10 common/image.c Ramdisk header is OK 1711 -12 common/image.c Ramdisk data has bad checksum 1712 11 common/image.c Ramdisk data has correct checksum 1713 12 common/image.c Ramdisk verification complete, start loading 1714 -13 common/image.c Wrong Image Type (not PPC Linux Ramdisk) 1715 13 common/image.c Start multifile image verification 1716 14 common/image.c No initial ramdisk, no multifile, continue. 1717 1718 15 lib_<arch>/bootm.c All preparation done, transferring control to OS 1719 1720 -30 lib_ppc/board.c Fatal error, hang the system 1721 -31 post/post.c POST test failed, detected by post_output_backlog() 1722 -32 post/post.c POST test failed, detected by post_run_single() 1723 1724 34 common/cmd_doc.c before loading a Image from a DOC device 1725 -35 common/cmd_doc.c Bad usage of "doc" command 1726 35 common/cmd_doc.c correct usage of "doc" command 1727 -36 common/cmd_doc.c No boot device 1728 36 common/cmd_doc.c correct boot device 1729 -37 common/cmd_doc.c Unknown Chip ID on boot device 1730 37 common/cmd_doc.c correct chip ID found, device available 1731 -38 common/cmd_doc.c Read Error on boot device 1732 38 common/cmd_doc.c reading Image header from DOC device OK 1733 -39 common/cmd_doc.c Image header has bad magic number 1734 39 common/cmd_doc.c Image header has correct magic number 1735 -40 common/cmd_doc.c Error reading Image from DOC device 1736 40 common/cmd_doc.c Image header has correct magic number 1737 41 common/cmd_ide.c before loading a Image from a IDE device 1738 -42 common/cmd_ide.c Bad usage of "ide" command 1739 42 common/cmd_ide.c correct usage of "ide" command 1740 -43 common/cmd_ide.c No boot device 1741 43 common/cmd_ide.c boot device found 1742 -44 common/cmd_ide.c Device not available 1743 44 common/cmd_ide.c Device available 1744 -45 common/cmd_ide.c wrong partition selected 1745 45 common/cmd_ide.c partition selected 1746 -46 common/cmd_ide.c Unknown partition table 1747 46 common/cmd_ide.c valid partition table found 1748 -47 common/cmd_ide.c Invalid partition type 1749 47 common/cmd_ide.c correct partition type 1750 -48 common/cmd_ide.c Error reading Image Header on boot device 1751 48 common/cmd_ide.c reading Image Header from IDE device OK 1752 -49 common/cmd_ide.c Image header has bad magic number 1753 49 common/cmd_ide.c Image header has correct magic number 1754 -50 common/cmd_ide.c Image header has bad checksum 1755 50 common/cmd_ide.c Image header has correct checksum 1756 -51 common/cmd_ide.c Error reading Image from IDE device 1757 51 common/cmd_ide.c reading Image from IDE device OK 1758 52 common/cmd_nand.c before loading a Image from a NAND device 1759 -53 common/cmd_nand.c Bad usage of "nand" command 1760 53 common/cmd_nand.c correct usage of "nand" command 1761 -54 common/cmd_nand.c No boot device 1762 54 common/cmd_nand.c boot device found 1763 -55 common/cmd_nand.c Unknown Chip ID on boot device 1764 55 common/cmd_nand.c correct chip ID found, device available 1765 -56 common/cmd_nand.c Error reading Image Header on boot device 1766 56 common/cmd_nand.c reading Image Header from NAND device OK 1767 -57 common/cmd_nand.c Image header has bad magic number 1768 57 common/cmd_nand.c Image header has correct magic number 1769 -58 common/cmd_nand.c Error reading Image from NAND device 1770 58 common/cmd_nand.c reading Image from NAND device OK 1771 1772 -60 common/env_common.c Environment has a bad CRC, using default 1773 1774 64 net/eth.c starting with Ethernetconfiguration. 1775 -64 net/eth.c no Ethernet found. 1776 65 net/eth.c Ethernet found. 1777 1778 -80 common/cmd_net.c usage wrong 1779 80 common/cmd_net.c before calling NetLoop() 1780 -81 common/cmd_net.c some error in NetLoop() occured 1781 81 common/cmd_net.c NetLoop() back without error 1782 -82 common/cmd_net.c size == 0 (File with size 0 loaded) 1783 82 common/cmd_net.c trying automatic boot 1784 83 common/cmd_net.c running autoscript 1785 -83 common/cmd_net.c some error in automatic boot or autoscript 1786 84 common/cmd_net.c end without errors 1787 1788FIT uImage format: 1789 1790 Arg Where When 1791 100 common/cmd_bootm.c Kernel FIT Image has correct format 1792 -100 common/cmd_bootm.c Kernel FIT Image has incorrect format 1793 101 common/cmd_bootm.c No Kernel subimage unit name, using configuration 1794 -101 common/cmd_bootm.c Can't get configuration for kernel subimage 1795 102 common/cmd_bootm.c Kernel unit name specified 1796 -103 common/cmd_bootm.c Can't get kernel subimage node offset 1797 103 common/cmd_bootm.c Found configuration node 1798 104 common/cmd_bootm.c Got kernel subimage node offset 1799 -104 common/cmd_bootm.c Kernel subimage hash verification failed 1800 105 common/cmd_bootm.c Kernel subimage hash verification OK 1801 -105 common/cmd_bootm.c Kernel subimage is for unsupported architecture 1802 106 common/cmd_bootm.c Architecture check OK 1803 -106 common/cmd_bootm.c Kernel subimage has wrong typea 1804 107 common/cmd_bootm.c Kernel subimge type OK 1805 -107 common/cmd_bootm.c Can't get kernel subimage data/size 1806 108 common/cmd_bootm.c Got kernel subimage data/size 1807 -108 common/cmd_bootm.c Wrong image type (not legacy, FIT) 1808 -109 common/cmd_bootm.c Can't get kernel subimage type 1809 -110 common/cmd_bootm.c Can't get kernel subimage comp 1810 -111 common/cmd_bootm.c Can't get kernel subimage os 1811 -112 common/cmd_bootm.c Can't get kernel subimage load address 1812 -113 common/cmd_bootm.c Image uncompress/copy overwrite error 1813 1814 120 common/image.c Start initial ramdisk verification 1815 -120 common/image.c Ramdisk FIT image has incorrect format 1816 121 common/image.c Ramdisk FIT image has correct format 1817 122 common/image.c No Ramdisk subimage unit name, using configuration 1818 -122 common/image.c Can't get configuration for ramdisk subimage 1819 123 common/image.c Ramdisk unit name specified 1820 -124 common/image.c Can't get ramdisk subimage node offset 1821 125 common/image.c Got ramdisk subimage node offset 1822 -125 common/image.c Ramdisk subimage hash verification failed 1823 126 common/image.c Ramdisk subimage hash verification OK 1824 -126 common/image.c Ramdisk subimage for unsupported architecture 1825 127 common/image.c Architecture check OK 1826 -127 common/image.c Can't get ramdisk subimage data/size 1827 128 common/image.c Got ramdisk subimage data/size 1828 129 common/image.c Can't get ramdisk load address 1829 -129 common/image.c Got ramdisk load address 1830 1831 -130 common/cmd_doc.c Icorrect FIT image format 1832 131 common/cmd_doc.c FIT image format OK 1833 1834 -140 common/cmd_ide.c Icorrect FIT image format 1835 141 common/cmd_ide.c FIT image format OK 1836 1837 -150 common/cmd_nand.c Icorrect FIT image format 1838 151 common/cmd_nand.c FIT image format OK 1839 1840 1841Modem Support: 1842-------------- 1843 1844[so far only for SMDK2400 and TRAB boards] 1845 1846- Modem support endable: 1847 CONFIG_MODEM_SUPPORT 1848 1849- RTS/CTS Flow control enable: 1850 CONFIG_HWFLOW 1851 1852- Modem debug support: 1853 CONFIG_MODEM_SUPPORT_DEBUG 1854 1855 Enables debugging stuff (char screen[1024], dbg()) 1856 for modem support. Useful only with BDI2000. 1857 1858- Interrupt support (PPC): 1859 1860 There are common interrupt_init() and timer_interrupt() 1861 for all PPC archs. interrupt_init() calls interrupt_init_cpu() 1862 for cpu specific initialization. interrupt_init_cpu() 1863 should set decrementer_count to appropriate value. If 1864 cpu resets decrementer automatically after interrupt 1865 (ppc4xx) it should set decrementer_count to zero. 1866 timer_interrupt() calls timer_interrupt_cpu() for cpu 1867 specific handling. If board has watchdog / status_led 1868 / other_activity_monitor it works automatically from 1869 general timer_interrupt(). 1870 1871- General: 1872 1873 In the target system modem support is enabled when a 1874 specific key (key combination) is pressed during 1875 power-on. Otherwise U-Boot will boot normally 1876 (autoboot). The key_pressed() fuction is called from 1877 board_init(). Currently key_pressed() is a dummy 1878 function, returning 1 and thus enabling modem 1879 initialization. 1880 1881 If there are no modem init strings in the 1882 environment, U-Boot proceed to autoboot; the 1883 previous output (banner, info printfs) will be 1884 supressed, though. 1885 1886 See also: doc/README.Modem 1887 1888 1889Configuration Settings: 1890----------------------- 1891 1892- CFG_LONGHELP: Defined when you want long help messages included; 1893 undefine this when you're short of memory. 1894 1895- CFG_PROMPT: This is what U-Boot prints on the console to 1896 prompt for user input. 1897 1898- CFG_CBSIZE: Buffer size for input from the Console 1899 1900- CFG_PBSIZE: Buffer size for Console output 1901 1902- CFG_MAXARGS: max. Number of arguments accepted for monitor commands 1903 1904- CFG_BARGSIZE: Buffer size for Boot Arguments which are passed to 1905 the application (usually a Linux kernel) when it is 1906 booted 1907 1908- CFG_BAUDRATE_TABLE: 1909 List of legal baudrate settings for this board. 1910 1911- CFG_CONSOLE_INFO_QUIET 1912 Suppress display of console information at boot. 1913 1914- CFG_CONSOLE_IS_IN_ENV 1915 If the board specific function 1916 extern int overwrite_console (void); 1917 returns 1, the stdin, stderr and stdout are switched to the 1918 serial port, else the settings in the environment are used. 1919 1920- CFG_CONSOLE_OVERWRITE_ROUTINE 1921 Enable the call to overwrite_console(). 1922 1923- CFG_CONSOLE_ENV_OVERWRITE 1924 Enable overwrite of previous console environment settings. 1925 1926- CFG_MEMTEST_START, CFG_MEMTEST_END: 1927 Begin and End addresses of the area used by the 1928 simple memory test. 1929 1930- CFG_ALT_MEMTEST: 1931 Enable an alternate, more extensive memory test. 1932 1933- CFG_MEMTEST_SCRATCH: 1934 Scratch address used by the alternate memory test 1935 You only need to set this if address zero isn't writeable 1936 1937- CFG_MEM_TOP_HIDE (PPC only): 1938 If CFG_MEM_TOP_HIDE is defined in the board config header, 1939 this specified memory area will get subtracted from the top 1940 (end) of ram and won't get "touched" at all by U-Boot. By 1941 fixing up gd->ram_size the Linux kernel should gets passed 1942 the now "corrected" memory size and won't touch it either. 1943 This should work for arch/ppc and arch/powerpc. Only Linux 1944 board ports in arch/powerpc with bootwrapper support that 1945 recalculate the memory size from the SDRAM controller setup 1946 will have to get fixed in Linux additionally. 1947 1948 This option can be used as a workaround for the 440EPx/GRx 1949 CHIP 11 errata where the last 256 bytes in SDRAM shouldn't 1950 be touched. 1951 1952 WARNING: Please make sure that this value is a multiple of 1953 the Linux page size (normally 4k). If this is not the case, 1954 then the end address of the Linux memory will be located at a 1955 non page size aligned address and this could cause major 1956 problems. 1957 1958- CFG_TFTP_LOADADDR: 1959 Default load address for network file downloads 1960 1961- CFG_LOADS_BAUD_CHANGE: 1962 Enable temporary baudrate change while serial download 1963 1964- CFG_SDRAM_BASE: 1965 Physical start address of SDRAM. _Must_ be 0 here. 1966 1967- CFG_MBIO_BASE: 1968 Physical start address of Motherboard I/O (if using a 1969 Cogent motherboard) 1970 1971- CFG_FLASH_BASE: 1972 Physical start address of Flash memory. 1973 1974- CFG_MONITOR_BASE: 1975 Physical start address of boot monitor code (set by 1976 make config files to be same as the text base address 1977 (TEXT_BASE) used when linking) - same as 1978 CFG_FLASH_BASE when booting from flash. 1979 1980- CFG_MONITOR_LEN: 1981 Size of memory reserved for monitor code, used to 1982 determine _at_compile_time_ (!) if the environment is 1983 embedded within the U-Boot image, or in a separate 1984 flash sector. 1985 1986- CFG_MALLOC_LEN: 1987 Size of DRAM reserved for malloc() use. 1988 1989- CFG_BOOTM_LEN: 1990 Normally compressed uImages are limited to an 1991 uncompressed size of 8 MBytes. If this is not enough, 1992 you can define CFG_BOOTM_LEN in your board config file 1993 to adjust this setting to your needs. 1994 1995- CFG_BOOTMAPSZ: 1996 Maximum size of memory mapped by the startup code of 1997 the Linux kernel; all data that must be processed by 1998 the Linux kernel (bd_info, boot arguments, eventually 1999 initrd image) must be put below this limit. 2000 2001- CFG_MAX_FLASH_BANKS: 2002 Max number of Flash memory banks 2003 2004- CFG_MAX_FLASH_SECT: 2005 Max number of sectors on a Flash chip 2006 2007- CFG_FLASH_ERASE_TOUT: 2008 Timeout for Flash erase operations (in ms) 2009 2010- CFG_FLASH_WRITE_TOUT: 2011 Timeout for Flash write operations (in ms) 2012 2013- CFG_FLASH_LOCK_TOUT 2014 Timeout for Flash set sector lock bit operation (in ms) 2015 2016- CFG_FLASH_UNLOCK_TOUT 2017 Timeout for Flash clear lock bits operation (in ms) 2018 2019- CFG_FLASH_PROTECTION 2020 If defined, hardware flash sectors protection is used 2021 instead of U-Boot software protection. 2022 2023- CFG_DIRECT_FLASH_TFTP: 2024 2025 Enable TFTP transfers directly to flash memory; 2026 without this option such a download has to be 2027 performed in two steps: (1) download to RAM, and (2) 2028 copy from RAM to flash. 2029 2030 The two-step approach is usually more reliable, since 2031 you can check if the download worked before you erase 2032 the flash, but in some situations (when sytem RAM is 2033 too limited to allow for a tempory copy of the 2034 downloaded image) this option may be very useful. 2035 2036- CFG_FLASH_CFI: 2037 Define if the flash driver uses extra elements in the 2038 common flash structure for storing flash geometry. 2039 2040- CFG_FLASH_CFI_DRIVER 2041 This option also enables the building of the cfi_flash driver 2042 in the drivers directory 2043 2044- CFG_FLASH_QUIET_TEST 2045 If this option is defined, the common CFI flash doesn't 2046 print it's warning upon not recognized FLASH banks. This 2047 is useful, if some of the configured banks are only 2048 optionally available. 2049 2050- CONFIG_FLASH_SHOW_PROGRESS 2051 If defined (must be an integer), print out countdown 2052 digits and dots. Recommended value: 45 (9..1) for 80 2053 column displays, 15 (3..1) for 40 column displays. 2054 2055- CFG_RX_ETH_BUFFER: 2056 Defines the number of ethernet receive buffers. On some 2057 ethernet controllers it is recommended to set this value 2058 to 8 or even higher (EEPRO100 or 405 EMAC), since all 2059 buffers can be full shortly after enabling the interface 2060 on high ethernet traffic. 2061 Defaults to 4 if not defined. 2062 2063The following definitions that deal with the placement and management 2064of environment data (variable area); in general, we support the 2065following configurations: 2066 2067- CFG_ENV_IS_IN_FLASH: 2068 2069 Define this if the environment is in flash memory. 2070 2071 a) The environment occupies one whole flash sector, which is 2072 "embedded" in the text segment with the U-Boot code. This 2073 happens usually with "bottom boot sector" or "top boot 2074 sector" type flash chips, which have several smaller 2075 sectors at the start or the end. For instance, such a 2076 layout can have sector sizes of 8, 2x4, 16, Nx32 kB. In 2077 such a case you would place the environment in one of the 2078 4 kB sectors - with U-Boot code before and after it. With 2079 "top boot sector" type flash chips, you would put the 2080 environment in one of the last sectors, leaving a gap 2081 between U-Boot and the environment. 2082 2083 - CFG_ENV_OFFSET: 2084 2085 Offset of environment data (variable area) to the 2086 beginning of flash memory; for instance, with bottom boot 2087 type flash chips the second sector can be used: the offset 2088 for this sector is given here. 2089 2090 CFG_ENV_OFFSET is used relative to CFG_FLASH_BASE. 2091 2092 - CFG_ENV_ADDR: 2093 2094 This is just another way to specify the start address of 2095 the flash sector containing the environment (instead of 2096 CFG_ENV_OFFSET). 2097 2098 - CFG_ENV_SECT_SIZE: 2099 2100 Size of the sector containing the environment. 2101 2102 2103 b) Sometimes flash chips have few, equal sized, BIG sectors. 2104 In such a case you don't want to spend a whole sector for 2105 the environment. 2106 2107 - CFG_ENV_SIZE: 2108 2109 If you use this in combination with CFG_ENV_IS_IN_FLASH 2110 and CFG_ENV_SECT_SIZE, you can specify to use only a part 2111 of this flash sector for the environment. This saves 2112 memory for the RAM copy of the environment. 2113 2114 It may also save flash memory if you decide to use this 2115 when your environment is "embedded" within U-Boot code, 2116 since then the remainder of the flash sector could be used 2117 for U-Boot code. It should be pointed out that this is 2118 STRONGLY DISCOURAGED from a robustness point of view: 2119 updating the environment in flash makes it always 2120 necessary to erase the WHOLE sector. If something goes 2121 wrong before the contents has been restored from a copy in 2122 RAM, your target system will be dead. 2123 2124 - CFG_ENV_ADDR_REDUND 2125 CFG_ENV_SIZE_REDUND 2126 2127 These settings describe a second storage area used to hold 2128 a redundand copy of the environment data, so that there is 2129 a valid backup copy in case there is a power failure during 2130 a "saveenv" operation. 2131 2132BE CAREFUL! Any changes to the flash layout, and some changes to the 2133source code will make it necessary to adapt <board>/u-boot.lds* 2134accordingly! 2135 2136 2137- CFG_ENV_IS_IN_NVRAM: 2138 2139 Define this if you have some non-volatile memory device 2140 (NVRAM, battery buffered SRAM) which you want to use for the 2141 environment. 2142 2143 - CFG_ENV_ADDR: 2144 - CFG_ENV_SIZE: 2145 2146 These two #defines are used to determin the memory area you 2147 want to use for environment. It is assumed that this memory 2148 can just be read and written to, without any special 2149 provision. 2150 2151BE CAREFUL! The first access to the environment happens quite early 2152in U-Boot initalization (when we try to get the setting of for the 2153console baudrate). You *MUST* have mappend your NVRAM area then, or 2154U-Boot will hang. 2155 2156Please note that even with NVRAM we still use a copy of the 2157environment in RAM: we could work on NVRAM directly, but we want to 2158keep settings there always unmodified except somebody uses "saveenv" 2159to save the current settings. 2160 2161 2162- CFG_ENV_IS_IN_EEPROM: 2163 2164 Use this if you have an EEPROM or similar serial access 2165 device and a driver for it. 2166 2167 - CFG_ENV_OFFSET: 2168 - CFG_ENV_SIZE: 2169 2170 These two #defines specify the offset and size of the 2171 environment area within the total memory of your EEPROM. 2172 2173 - CFG_I2C_EEPROM_ADDR: 2174 If defined, specified the chip address of the EEPROM device. 2175 The default address is zero. 2176 2177 - CFG_EEPROM_PAGE_WRITE_BITS: 2178 If defined, the number of bits used to address bytes in a 2179 single page in the EEPROM device. A 64 byte page, for example 2180 would require six bits. 2181 2182 - CFG_EEPROM_PAGE_WRITE_DELAY_MS: 2183 If defined, the number of milliseconds to delay between 2184 page writes. The default is zero milliseconds. 2185 2186 - CFG_I2C_EEPROM_ADDR_LEN: 2187 The length in bytes of the EEPROM memory array address. Note 2188 that this is NOT the chip address length! 2189 2190 - CFG_I2C_EEPROM_ADDR_OVERFLOW: 2191 EEPROM chips that implement "address overflow" are ones 2192 like Catalyst 24WC04/08/16 which has 9/10/11 bits of 2193 address and the extra bits end up in the "chip address" bit 2194 slots. This makes a 24WC08 (1Kbyte) chip look like four 256 2195 byte chips. 2196 2197 Note that we consider the length of the address field to 2198 still be one byte because the extra address bits are hidden 2199 in the chip address. 2200 2201 - CFG_EEPROM_SIZE: 2202 The size in bytes of the EEPROM device. 2203 2204 2205- CFG_ENV_IS_IN_DATAFLASH: 2206 2207 Define this if you have a DataFlash memory device which you 2208 want to use for the environment. 2209 2210 - CFG_ENV_OFFSET: 2211 - CFG_ENV_ADDR: 2212 - CFG_ENV_SIZE: 2213 2214 These three #defines specify the offset and size of the 2215 environment area within the total memory of your DataFlash placed 2216 at the specified address. 2217 2218- CFG_ENV_IS_IN_NAND: 2219 2220 Define this if you have a NAND device which you want to use 2221 for the environment. 2222 2223 - CFG_ENV_OFFSET: 2224 - CFG_ENV_SIZE: 2225 2226 These two #defines specify the offset and size of the environment 2227 area within the first NAND device. 2228 2229 - CFG_ENV_OFFSET_REDUND 2230 2231 This setting describes a second storage area of CFG_ENV_SIZE 2232 size used to hold a redundant copy of the environment data, 2233 so that there is a valid backup copy in case there is a 2234 power failure during a "saveenv" operation. 2235 2236 Note: CFG_ENV_OFFSET and CFG_ENV_OFFSET_REDUND must be aligned 2237 to a block boundary, and CFG_ENV_SIZE must be a multiple of 2238 the NAND devices block size. 2239 2240- CFG_SPI_INIT_OFFSET 2241 2242 Defines offset to the initial SPI buffer area in DPRAM. The 2243 area is used at an early stage (ROM part) if the environment 2244 is configured to reside in the SPI EEPROM: We need a 520 byte 2245 scratch DPRAM area. It is used between the two initialization 2246 calls (spi_init_f() and spi_init_r()). A value of 0xB00 seems 2247 to be a good choice since it makes it far enough from the 2248 start of the data area as well as from the stack pointer. 2249 2250Please note that the environment is read-only until the monitor 2251has been relocated to RAM and a RAM copy of the environment has been 2252created; also, when using EEPROM you will have to use getenv_r() 2253until then to read environment variables. 2254 2255The environment is protected by a CRC32 checksum. Before the monitor 2256is relocated into RAM, as a result of a bad CRC you will be working 2257with the compiled-in default environment - *silently*!!! [This is 2258necessary, because the first environment variable we need is the 2259"baudrate" setting for the console - if we have a bad CRC, we don't 2260have any device yet where we could complain.] 2261 2262Note: once the monitor has been relocated, then it will complain if 2263the default environment is used; a new CRC is computed as soon as you 2264use the "saveenv" command to store a valid environment. 2265 2266- CFG_FAULT_ECHO_LINK_DOWN: 2267 Echo the inverted Ethernet link state to the fault LED. 2268 2269 Note: If this option is active, then CFG_FAULT_MII_ADDR 2270 also needs to be defined. 2271 2272- CFG_FAULT_MII_ADDR: 2273 MII address of the PHY to check for the Ethernet link state. 2274 2275- CFG_64BIT_VSPRINTF: 2276 Makes vsprintf (and all *printf functions) support printing 2277 of 64bit values by using the L quantifier 2278 2279- CFG_64BIT_STRTOUL: 2280 Adds simple_strtoull that returns a 64bit value 2281 2282Low Level (hardware related) configuration options: 2283--------------------------------------------------- 2284 2285- CFG_CACHELINE_SIZE: 2286 Cache Line Size of the CPU. 2287 2288- CFG_DEFAULT_IMMR: 2289 Default address of the IMMR after system reset. 2290 2291 Needed on some 8260 systems (MPC8260ADS, PQ2FADS-ZU, 2292 and RPXsuper) to be able to adjust the position of 2293 the IMMR register after a reset. 2294 2295- Floppy Disk Support: 2296 CFG_FDC_DRIVE_NUMBER 2297 2298 the default drive number (default value 0) 2299 2300 CFG_ISA_IO_STRIDE 2301 2302 defines the spacing between fdc chipset registers 2303 (default value 1) 2304 2305 CFG_ISA_IO_OFFSET 2306 2307 defines the offset of register from address. It 2308 depends on which part of the data bus is connected to 2309 the fdc chipset. (default value 0) 2310 2311 If CFG_ISA_IO_STRIDE CFG_ISA_IO_OFFSET and 2312 CFG_FDC_DRIVE_NUMBER are undefined, they take their 2313 default value. 2314 2315 if CFG_FDC_HW_INIT is defined, then the function 2316 fdc_hw_init() is called at the beginning of the FDC 2317 setup. fdc_hw_init() must be provided by the board 2318 source code. It is used to make hardware dependant 2319 initializations. 2320 2321- CFG_IMMR: Physical address of the Internal Memory. 2322 DO NOT CHANGE unless you know exactly what you're 2323 doing! (11-4) [MPC8xx/82xx systems only] 2324 2325- CFG_INIT_RAM_ADDR: 2326 2327 Start address of memory area that can be used for 2328 initial data and stack; please note that this must be 2329 writable memory that is working WITHOUT special 2330 initialization, i. e. you CANNOT use normal RAM which 2331 will become available only after programming the 2332 memory controller and running certain initialization 2333 sequences. 2334 2335 U-Boot uses the following memory types: 2336 - MPC8xx and MPC8260: IMMR (internal memory of the CPU) 2337 - MPC824X: data cache 2338 - PPC4xx: data cache 2339 2340- CFG_GBL_DATA_OFFSET: 2341 2342 Offset of the initial data structure in the memory 2343 area defined by CFG_INIT_RAM_ADDR. Usually 2344 CFG_GBL_DATA_OFFSET is chosen such that the initial 2345 data is located at the end of the available space 2346 (sometimes written as (CFG_INIT_RAM_END - 2347 CFG_INIT_DATA_SIZE), and the initial stack is just 2348 below that area (growing from (CFG_INIT_RAM_ADDR + 2349 CFG_GBL_DATA_OFFSET) downward. 2350 2351 Note: 2352 On the MPC824X (or other systems that use the data 2353 cache for initial memory) the address chosen for 2354 CFG_INIT_RAM_ADDR is basically arbitrary - it must 2355 point to an otherwise UNUSED address space between 2356 the top of RAM and the start of the PCI space. 2357 2358- CFG_SIUMCR: SIU Module Configuration (11-6) 2359 2360- CFG_SYPCR: System Protection Control (11-9) 2361 2362- CFG_TBSCR: Time Base Status and Control (11-26) 2363 2364- CFG_PISCR: Periodic Interrupt Status and Control (11-31) 2365 2366- CFG_PLPRCR: PLL, Low-Power, and Reset Control Register (15-30) 2367 2368- CFG_SCCR: System Clock and reset Control Register (15-27) 2369 2370- CFG_OR_TIMING_SDRAM: 2371 SDRAM timing 2372 2373- CFG_MAMR_PTA: 2374 periodic timer for refresh 2375 2376- CFG_DER: Debug Event Register (37-47) 2377 2378- FLASH_BASE0_PRELIM, FLASH_BASE1_PRELIM, CFG_REMAP_OR_AM, 2379 CFG_PRELIM_OR_AM, CFG_OR_TIMING_FLASH, CFG_OR0_REMAP, 2380 CFG_OR0_PRELIM, CFG_BR0_PRELIM, CFG_OR1_REMAP, CFG_OR1_PRELIM, 2381 CFG_BR1_PRELIM: 2382 Memory Controller Definitions: BR0/1 and OR0/1 (FLASH) 2383 2384- SDRAM_BASE2_PRELIM, SDRAM_BASE3_PRELIM, SDRAM_MAX_SIZE, 2385 CFG_OR_TIMING_SDRAM, CFG_OR2_PRELIM, CFG_BR2_PRELIM, 2386 CFG_OR3_PRELIM, CFG_BR3_PRELIM: 2387 Memory Controller Definitions: BR2/3 and OR2/3 (SDRAM) 2388 2389- CFG_MAMR_PTA, CFG_MPTPR_2BK_4K, CFG_MPTPR_1BK_4K, CFG_MPTPR_2BK_8K, 2390 CFG_MPTPR_1BK_8K, CFG_MAMR_8COL, CFG_MAMR_9COL: 2391 Machine Mode Register and Memory Periodic Timer 2392 Prescaler definitions (SDRAM timing) 2393 2394- CFG_I2C_UCODE_PATCH, CFG_I2C_DPMEM_OFFSET [0x1FC0]: 2395 enable I2C microcode relocation patch (MPC8xx); 2396 define relocation offset in DPRAM [DSP2] 2397 2398- CFG_SMC_UCODE_PATCH, CFG_SMC_DPMEM_OFFSET [0x1FC0]: 2399 enable SMC microcode relocation patch (MPC8xx); 2400 define relocation offset in DPRAM [SMC1] 2401 2402- CFG_SPI_UCODE_PATCH, CFG_SPI_DPMEM_OFFSET [0x1FC0]: 2403 enable SPI microcode relocation patch (MPC8xx); 2404 define relocation offset in DPRAM [SCC4] 2405 2406- CFG_USE_OSCCLK: 2407 Use OSCM clock mode on MBX8xx board. Be careful, 2408 wrong setting might damage your board. Read 2409 doc/README.MBX before setting this variable! 2410 2411- CFG_CPM_POST_WORD_ADDR: (MPC8xx, MPC8260 only) 2412 Offset of the bootmode word in DPRAM used by post 2413 (Power On Self Tests). This definition overrides 2414 #define'd default value in commproc.h resp. 2415 cpm_8260.h. 2416 2417- CFG_PCI_SLV_MEM_LOCAL, CFG_PCI_SLV_MEM_BUS, CFG_PICMR0_MASK_ATTRIB, 2418 CFG_PCI_MSTR0_LOCAL, CFG_PCIMSK0_MASK, CFG_PCI_MSTR1_LOCAL, 2419 CFG_PCIMSK1_MASK, CFG_PCI_MSTR_MEM_LOCAL, CFG_PCI_MSTR_MEM_BUS, 2420 CFG_CPU_PCI_MEM_START, CFG_PCI_MSTR_MEM_SIZE, CFG_POCMR0_MASK_ATTRIB, 2421 CFG_PCI_MSTR_MEMIO_LOCAL, CFG_PCI_MSTR_MEMIO_BUS, CPU_PCI_MEMIO_START, 2422 CFG_PCI_MSTR_MEMIO_SIZE, CFG_POCMR1_MASK_ATTRIB, CFG_PCI_MSTR_IO_LOCAL, 2423 CFG_PCI_MSTR_IO_BUS, CFG_CPU_PCI_IO_START, CFG_PCI_MSTR_IO_SIZE, 2424 CFG_POCMR2_MASK_ATTRIB: (MPC826x only) 2425 Overrides the default PCI memory map in cpu/mpc8260/pci.c if set. 2426 2427- CONFIG_SPD_EEPROM 2428 Get DDR timing information from an I2C EEPROM. Common 2429 with pluggable memory modules such as SODIMMs 2430 2431 SPD_EEPROM_ADDRESS 2432 I2C address of the SPD EEPROM 2433 2434- CFG_SPD_BUS_NUM 2435 If SPD EEPROM is on an I2C bus other than the first 2436 one, specify here. Note that the value must resolve 2437 to something your driver can deal with. 2438 2439- CFG_83XX_DDR_USES_CS0 2440 Only for 83xx systems. If specified, then DDR should 2441 be configured using CS0 and CS1 instead of CS2 and CS3. 2442 2443- CFG_83XX_DDR_USES_CS0 2444 Only for 83xx systems. If specified, then DDR should 2445 be configured using CS0 and CS1 instead of CS2 and CS3. 2446 2447- CONFIG_ETHER_ON_FEC[12] 2448 Define to enable FEC[12] on a 8xx series processor. 2449 2450- CONFIG_FEC[12]_PHY 2451 Define to the hardcoded PHY address which corresponds 2452 to the given FEC; i. e. 2453 #define CONFIG_FEC1_PHY 4 2454 means that the PHY with address 4 is connected to FEC1 2455 2456 When set to -1, means to probe for first available. 2457 2458- CONFIG_FEC[12]_PHY_NORXERR 2459 The PHY does not have a RXERR line (RMII only). 2460 (so program the FEC to ignore it). 2461 2462- CONFIG_RMII 2463 Enable RMII mode for all FECs. 2464 Note that this is a global option, we can't 2465 have one FEC in standard MII mode and another in RMII mode. 2466 2467- CONFIG_CRC32_VERIFY 2468 Add a verify option to the crc32 command. 2469 The syntax is: 2470 2471 => crc32 -v <address> <count> <crc32> 2472 2473 Where address/count indicate a memory area 2474 and crc32 is the correct crc32 which the 2475 area should have. 2476 2477- CONFIG_LOOPW 2478 Add the "loopw" memory command. This only takes effect if 2479 the memory commands are activated globally (CONFIG_CMD_MEM). 2480 2481- CONFIG_MX_CYCLIC 2482 Add the "mdc" and "mwc" memory commands. These are cyclic 2483 "md/mw" commands. 2484 Examples: 2485 2486 => mdc.b 10 4 500 2487 This command will print 4 bytes (10,11,12,13) each 500 ms. 2488 2489 => mwc.l 100 12345678 10 2490 This command will write 12345678 to address 100 all 10 ms. 2491 2492 This only takes effect if the memory commands are activated 2493 globally (CONFIG_CMD_MEM). 2494 2495- CONFIG_SKIP_LOWLEVEL_INIT 2496- CONFIG_SKIP_RELOCATE_UBOOT 2497 2498 [ARM only] If these variables are defined, then 2499 certain low level initializations (like setting up 2500 the memory controller) are omitted and/or U-Boot does 2501 not relocate itself into RAM. 2502 Normally these variables MUST NOT be defined. The 2503 only exception is when U-Boot is loaded (to RAM) by 2504 some other boot loader or by a debugger which 2505 performs these intializations itself. 2506 2507 2508Building the Software: 2509====================== 2510 2511Building U-Boot has been tested in several native build environments 2512and in many different cross environments. Of course we cannot support 2513all possibly existing versions of cross development tools in all 2514(potentially obsolete) versions. In case of tool chain problems we 2515recommend to use the ELDK (see http://www.denx.de/wiki/DULG/ELDK) 2516which is extensively used to build and test U-Boot. 2517 2518If you are not using a native environment, it is assumed that you 2519have GNU cross compiling tools available in your path. In this case, 2520you must set the environment variable CROSS_COMPILE in your shell. 2521Note that no changes to the Makefile or any other source files are 2522necessary. For example using the ELDK on a 4xx CPU, please enter: 2523 2524 $ CROSS_COMPILE=ppc_4xx- 2525 $ export CROSS_COMPILE 2526 2527U-Boot is intended to be simple to build. After installing the 2528sources you must configure U-Boot for one specific board type. This 2529is done by typing: 2530 2531 make NAME_config 2532 2533where "NAME_config" is the name of one of the existing configu- 2534rations; see the main Makefile for supported names. 2535 2536Note: for some board special configuration names may exist; check if 2537 additional information is available from the board vendor; for 2538 instance, the TQM823L systems are available without (standard) 2539 or with LCD support. You can select such additional "features" 2540 when chosing the configuration, i. e. 2541 2542 make TQM823L_config 2543 - will configure for a plain TQM823L, i. e. no LCD support 2544 2545 make TQM823L_LCD_config 2546 - will configure for a TQM823L with U-Boot console on LCD 2547 2548 etc. 2549 2550 2551Finally, type "make all", and you should get some working U-Boot 2552images ready for download to / installation on your system: 2553 2554- "u-boot.bin" is a raw binary image 2555- "u-boot" is an image in ELF binary format 2556- "u-boot.srec" is in Motorola S-Record format 2557 2558By default the build is performed locally and the objects are saved 2559in the source directory. One of the two methods can be used to change 2560this behavior and build U-Boot to some external directory: 2561 25621. Add O= to the make command line invocations: 2563 2564 make O=/tmp/build distclean 2565 make O=/tmp/build NAME_config 2566 make O=/tmp/build all 2567 25682. Set environment variable BUILD_DIR to point to the desired location: 2569 2570 export BUILD_DIR=/tmp/build 2571 make distclean 2572 make NAME_config 2573 make all 2574 2575Note that the command line "O=" setting overrides the BUILD_DIR environment 2576variable. 2577 2578 2579Please be aware that the Makefiles assume you are using GNU make, so 2580for instance on NetBSD you might need to use "gmake" instead of 2581native "make". 2582 2583 2584If the system board that you have is not listed, then you will need 2585to port U-Boot to your hardware platform. To do this, follow these 2586steps: 2587 25881. Add a new configuration option for your board to the toplevel 2589 "Makefile" and to the "MAKEALL" script, using the existing 2590 entries as examples. Note that here and at many other places 2591 boards and other names are listed in alphabetical sort order. Please 2592 keep this order. 25932. Create a new directory to hold your board specific code. Add any 2594 files you need. In your board directory, you will need at least 2595 the "Makefile", a "<board>.c", "flash.c" and "u-boot.lds". 25963. Create a new configuration file "include/configs/<board>.h" for 2597 your board 25983. If you're porting U-Boot to a new CPU, then also create a new 2599 directory to hold your CPU specific code. Add any files you need. 26004. Run "make <board>_config" with your new name. 26015. Type "make", and you should get a working "u-boot.srec" file 2602 to be installed on your target system. 26036. Debug and solve any problems that might arise. 2604 [Of course, this last step is much harder than it sounds.] 2605 2606 2607Testing of U-Boot Modifications, Ports to New Hardware, etc.: 2608============================================================== 2609 2610If you have modified U-Boot sources (for instance added a new board 2611or support for new devices, a new CPU, etc.) you are expected to 2612provide feedback to the other developers. The feedback normally takes 2613the form of a "patch", i. e. a context diff against a certain (latest 2614official or latest in the git repository) version of U-Boot sources. 2615 2616But before you submit such a patch, please verify that your modifi- 2617cation did not break existing code. At least make sure that *ALL* of 2618the supported boards compile WITHOUT ANY compiler warnings. To do so, 2619just run the "MAKEALL" script, which will configure and build U-Boot 2620for ALL supported system. Be warned, this will take a while. You can 2621select which (cross) compiler to use by passing a `CROSS_COMPILE' 2622environment variable to the script, i. e. to use the ELDK cross tools 2623you can type 2624 2625 CROSS_COMPILE=ppc_8xx- MAKEALL 2626 2627or to build on a native PowerPC system you can type 2628 2629 CROSS_COMPILE=' ' MAKEALL 2630 2631When using the MAKEALL script, the default behaviour is to build 2632U-Boot in the source directory. This location can be changed by 2633setting the BUILD_DIR environment variable. Also, for each target 2634built, the MAKEALL script saves two log files (<target>.ERR and 2635<target>.MAKEALL) in the <source dir>/LOG directory. This default 2636location can be changed by setting the MAKEALL_LOGDIR environment 2637variable. For example: 2638 2639 export BUILD_DIR=/tmp/build 2640 export MAKEALL_LOGDIR=/tmp/log 2641 CROSS_COMPILE=ppc_8xx- MAKEALL 2642 2643With the above settings build objects are saved in the /tmp/build, 2644log files are saved in the /tmp/log and the source tree remains clean 2645during the whole build process. 2646 2647 2648See also "U-Boot Porting Guide" below. 2649 2650 2651Monitor Commands - Overview: 2652============================ 2653 2654go - start application at address 'addr' 2655run - run commands in an environment variable 2656bootm - boot application image from memory 2657bootp - boot image via network using BootP/TFTP protocol 2658tftpboot- boot image via network using TFTP protocol 2659 and env variables "ipaddr" and "serverip" 2660 (and eventually "gatewayip") 2661rarpboot- boot image via network using RARP/TFTP protocol 2662diskboot- boot from IDE devicebootd - boot default, i.e., run 'bootcmd' 2663loads - load S-Record file over serial line 2664loadb - load binary file over serial line (kermit mode) 2665md - memory display 2666mm - memory modify (auto-incrementing) 2667nm - memory modify (constant address) 2668mw - memory write (fill) 2669cp - memory copy 2670cmp - memory compare 2671crc32 - checksum calculation 2672imd - i2c memory display 2673imm - i2c memory modify (auto-incrementing) 2674inm - i2c memory modify (constant address) 2675imw - i2c memory write (fill) 2676icrc32 - i2c checksum calculation 2677iprobe - probe to discover valid I2C chip addresses 2678iloop - infinite loop on address range 2679isdram - print SDRAM configuration information 2680sspi - SPI utility commands 2681base - print or set address offset 2682printenv- print environment variables 2683setenv - set environment variables 2684saveenv - save environment variables to persistent storage 2685protect - enable or disable FLASH write protection 2686erase - erase FLASH memory 2687flinfo - print FLASH memory information 2688bdinfo - print Board Info structure 2689iminfo - print header information for application image 2690coninfo - print console devices and informations 2691ide - IDE sub-system 2692loop - infinite loop on address range 2693loopw - infinite write loop on address range 2694mtest - simple RAM test 2695icache - enable or disable instruction cache 2696dcache - enable or disable data cache 2697reset - Perform RESET of the CPU 2698echo - echo args to console 2699version - print monitor version 2700help - print online help 2701? - alias for 'help' 2702 2703 2704Monitor Commands - Detailed Description: 2705======================================== 2706 2707TODO. 2708 2709For now: just type "help <command>". 2710 2711 2712Environment Variables: 2713====================== 2714 2715U-Boot supports user configuration using Environment Variables which 2716can be made persistent by saving to Flash memory. 2717 2718Environment Variables are set using "setenv", printed using 2719"printenv", and saved to Flash using "saveenv". Using "setenv" 2720without a value can be used to delete a variable from the 2721environment. As long as you don't save the environment you are 2722working with an in-memory copy. In case the Flash area containing the 2723environment is erased by accident, a default environment is provided. 2724 2725Some configuration options can be set using Environment Variables: 2726 2727 baudrate - see CONFIG_BAUDRATE 2728 2729 bootdelay - see CONFIG_BOOTDELAY 2730 2731 bootcmd - see CONFIG_BOOTCOMMAND 2732 2733 bootargs - Boot arguments when booting an RTOS image 2734 2735 bootfile - Name of the image to load with TFTP 2736 2737 autoload - if set to "no" (any string beginning with 'n'), 2738 "bootp" will just load perform a lookup of the 2739 configuration from the BOOTP server, but not try to 2740 load any image using TFTP 2741 2742 autoscript - if set to "yes" commands like "loadb", "loady", 2743 "bootp", "tftpb", "rarpboot" and "nfs" will attempt 2744 to automatically run script images (by internally 2745 calling "autoscript"). 2746 2747 autoscript_uname - if script image is in a format (FIT) this 2748 variable is used to get script subimage unit name. 2749 2750 autostart - if set to "yes", an image loaded using the "bootp", 2751 "rarpboot", "tftpboot" or "diskboot" commands will 2752 be automatically started (by internally calling 2753 "bootm") 2754 2755 If set to "no", a standalone image passed to the 2756 "bootm" command will be copied to the load address 2757 (and eventually uncompressed), but NOT be started. 2758 This can be used to load and uncompress arbitrary 2759 data. 2760 2761 i2cfast - (PPC405GP|PPC405EP only) 2762 if set to 'y' configures Linux I2C driver for fast 2763 mode (400kHZ). This environment variable is used in 2764 initialization code. So, for changes to be effective 2765 it must be saved and board must be reset. 2766 2767 initrd_high - restrict positioning of initrd images: 2768 If this variable is not set, initrd images will be 2769 copied to the highest possible address in RAM; this 2770 is usually what you want since it allows for 2771 maximum initrd size. If for some reason you want to 2772 make sure that the initrd image is loaded below the 2773 CFG_BOOTMAPSZ limit, you can set this environment 2774 variable to a value of "no" or "off" or "0". 2775 Alternatively, you can set it to a maximum upper 2776 address to use (U-Boot will still check that it 2777 does not overwrite the U-Boot stack and data). 2778 2779 For instance, when you have a system with 16 MB 2780 RAM, and want to reserve 4 MB from use by Linux, 2781 you can do this by adding "mem=12M" to the value of 2782 the "bootargs" variable. However, now you must make 2783 sure that the initrd image is placed in the first 2784 12 MB as well - this can be done with 2785 2786 setenv initrd_high 00c00000 2787 2788 If you set initrd_high to 0xFFFFFFFF, this is an 2789 indication to U-Boot that all addresses are legal 2790 for the Linux kernel, including addresses in flash 2791 memory. In this case U-Boot will NOT COPY the 2792 ramdisk at all. This may be useful to reduce the 2793 boot time on your system, but requires that this 2794 feature is supported by your Linux kernel. 2795 2796 ipaddr - IP address; needed for tftpboot command 2797 2798 loadaddr - Default load address for commands like "bootp", 2799 "rarpboot", "tftpboot", "loadb" or "diskboot" 2800 2801 loads_echo - see CONFIG_LOADS_ECHO 2802 2803 serverip - TFTP server IP address; needed for tftpboot command 2804 2805 bootretry - see CONFIG_BOOT_RETRY_TIME 2806 2807 bootdelaykey - see CONFIG_AUTOBOOT_DELAY_STR 2808 2809 bootstopkey - see CONFIG_AUTOBOOT_STOP_STR 2810 2811 ethprime - When CONFIG_NET_MULTI is enabled controls which 2812 interface is used first. 2813 2814 ethact - When CONFIG_NET_MULTI is enabled controls which 2815 interface is currently active. For example you 2816 can do the following 2817 2818 => setenv ethact FEC ETHERNET 2819 => ping 192.168.0.1 # traffic sent on FEC ETHERNET 2820 => setenv ethact SCC ETHERNET 2821 => ping 10.0.0.1 # traffic sent on SCC ETHERNET 2822 2823 ethrotate - When set to "no" U-Boot does not go through all 2824 available network interfaces. 2825 It just stays at the currently selected interface. 2826 2827 netretry - When set to "no" each network operation will 2828 either succeed or fail without retrying. 2829 When set to "once" the network operation will 2830 fail when all the available network interfaces 2831 are tried once without success. 2832 Useful on scripts which control the retry operation 2833 themselves. 2834 2835 npe_ucode - see CONFIG_IXP4XX_NPE_EXT_UCOD 2836 if set load address for the npe microcode 2837 2838 tftpsrcport - If this is set, the value is used for TFTP's 2839 UDP source port. 2840 2841 tftpdstport - If this is set, the value is used for TFTP's UDP 2842 destination port instead of the Well Know Port 69. 2843 2844 vlan - When set to a value < 4095 the traffic over 2845 ethernet is encapsulated/received over 802.1q 2846 VLAN tagged frames. 2847 2848The following environment variables may be used and automatically 2849updated by the network boot commands ("bootp" and "rarpboot"), 2850depending the information provided by your boot server: 2851 2852 bootfile - see above 2853 dnsip - IP address of your Domain Name Server 2854 dnsip2 - IP address of your secondary Domain Name Server 2855 gatewayip - IP address of the Gateway (Router) to use 2856 hostname - Target hostname 2857 ipaddr - see above 2858 netmask - Subnet Mask 2859 rootpath - Pathname of the root filesystem on the NFS server 2860 serverip - see above 2861 2862 2863There are two special Environment Variables: 2864 2865 serial# - contains hardware identification information such 2866 as type string and/or serial number 2867 ethaddr - Ethernet address 2868 2869These variables can be set only once (usually during manufacturing of 2870the board). U-Boot refuses to delete or overwrite these variables 2871once they have been set once. 2872 2873 2874Further special Environment Variables: 2875 2876 ver - Contains the U-Boot version string as printed 2877 with the "version" command. This variable is 2878 readonly (see CONFIG_VERSION_VARIABLE). 2879 2880 2881Please note that changes to some configuration parameters may take 2882only effect after the next boot (yes, that's just like Windoze :-). 2883 2884 2885Command Line Parsing: 2886===================== 2887 2888There are two different command line parsers available with U-Boot: 2889the old "simple" one, and the much more powerful "hush" shell: 2890 2891Old, simple command line parser: 2892-------------------------------- 2893 2894- supports environment variables (through setenv / saveenv commands) 2895- several commands on one line, separated by ';' 2896- variable substitution using "... ${name} ..." syntax 2897- special characters ('$', ';') can be escaped by prefixing with '\', 2898 for example: 2899 setenv bootcmd bootm \${address} 2900- You can also escape text by enclosing in single apostrophes, for example: 2901 setenv addip 'setenv bootargs $bootargs ip=$ipaddr:$serverip:$gatewayip:$netmask:$hostname::off' 2902 2903Hush shell: 2904----------- 2905 2906- similar to Bourne shell, with control structures like 2907 if...then...else...fi, for...do...done; while...do...done, 2908 until...do...done, ... 2909- supports environment ("global") variables (through setenv / saveenv 2910 commands) and local shell variables (through standard shell syntax 2911 "name=value"); only environment variables can be used with "run" 2912 command 2913 2914General rules: 2915-------------- 2916 2917(1) If a command line (or an environment variable executed by a "run" 2918 command) contains several commands separated by semicolon, and 2919 one of these commands fails, then the remaining commands will be 2920 executed anyway. 2921 2922(2) If you execute several variables with one call to run (i. e. 2923 calling run with a list af variables as arguments), any failing 2924 command will cause "run" to terminate, i. e. the remaining 2925 variables are not executed. 2926 2927Note for Redundant Ethernet Interfaces: 2928======================================= 2929 2930Some boards come with redundant ethernet interfaces; U-Boot supports 2931such configurations and is capable of automatic selection of a 2932"working" interface when needed. MAC assignment works as follows: 2933 2934Network interfaces are numbered eth0, eth1, eth2, ... Corresponding 2935MAC addresses can be stored in the environment as "ethaddr" (=>eth0), 2936"eth1addr" (=>eth1), "eth2addr", ... 2937 2938If the network interface stores some valid MAC address (for instance 2939in SROM), this is used as default address if there is NO correspon- 2940ding setting in the environment; if the corresponding environment 2941variable is set, this overrides the settings in the card; that means: 2942 2943o If the SROM has a valid MAC address, and there is no address in the 2944 environment, the SROM's address is used. 2945 2946o If there is no valid address in the SROM, and a definition in the 2947 environment exists, then the value from the environment variable is 2948 used. 2949 2950o If both the SROM and the environment contain a MAC address, and 2951 both addresses are the same, this MAC address is used. 2952 2953o If both the SROM and the environment contain a MAC address, and the 2954 addresses differ, the value from the environment is used and a 2955 warning is printed. 2956 2957o If neither SROM nor the environment contain a MAC address, an error 2958 is raised. 2959 2960 2961Image Formats: 2962============== 2963 2964U-Boot is capable of booting (and performing other auxiliary operations on) 2965images in two formats: 2966 2967New uImage format (FIT) 2968----------------------- 2969 2970Flexible and powerful format based on Flattened Image Tree -- FIT (similar 2971to Flattened Device Tree). It allows the use of images with multiple 2972components (several kernels, ramdisks, etc.), with contents protected by 2973SHA1, MD5 or CRC32. More details are found in the doc/uImage.FIT directory. 2974 2975 2976Old uImage format 2977----------------- 2978 2979Old image format is based on binary files which can be basically anything, 2980preceded by a special header; see the definitions in include/image.h for 2981details; basically, the header defines the following image properties: 2982 2983* Target Operating System (Provisions for OpenBSD, NetBSD, FreeBSD, 2984 4.4BSD, Linux, SVR4, Esix, Solaris, Irix, SCO, Dell, NCR, VxWorks, 2985 LynxOS, pSOS, QNX, RTEMS, ARTOS; 2986 Currently supported: Linux, NetBSD, VxWorks, QNX, RTEMS, ARTOS, LynxOS). 2987* Target CPU Architecture (Provisions for Alpha, ARM, AVR32, Intel x86, 2988 IA64, MIPS, NIOS, PowerPC, IBM S390, SuperH, Sparc, Sparc 64 Bit; 2989 Currently supported: ARM, AVR32, Intel x86, MIPS, NIOS, PowerPC). 2990* Compression Type (uncompressed, gzip, bzip2) 2991* Load Address 2992* Entry Point 2993* Image Name 2994* Image Timestamp 2995 2996The header is marked by a special Magic Number, and both the header 2997and the data portions of the image are secured against corruption by 2998CRC32 checksums. 2999 3000 3001Linux Support: 3002============== 3003 3004Although U-Boot should support any OS or standalone application 3005easily, the main focus has always been on Linux during the design of 3006U-Boot. 3007 3008U-Boot includes many features that so far have been part of some 3009special "boot loader" code within the Linux kernel. Also, any 3010"initrd" images to be used are no longer part of one big Linux image; 3011instead, kernel and "initrd" are separate images. This implementation 3012serves several purposes: 3013 3014- the same features can be used for other OS or standalone 3015 applications (for instance: using compressed images to reduce the 3016 Flash memory footprint) 3017 3018- it becomes much easier to port new Linux kernel versions because 3019 lots of low-level, hardware dependent stuff are done by U-Boot 3020 3021- the same Linux kernel image can now be used with different "initrd" 3022 images; of course this also means that different kernel images can 3023 be run with the same "initrd". This makes testing easier (you don't 3024 have to build a new "zImage.initrd" Linux image when you just 3025 change a file in your "initrd"). Also, a field-upgrade of the 3026 software is easier now. 3027 3028 3029Linux HOWTO: 3030============ 3031 3032Porting Linux to U-Boot based systems: 3033--------------------------------------- 3034 3035U-Boot cannot save you from doing all the necessary modifications to 3036configure the Linux device drivers for use with your target hardware 3037(no, we don't intend to provide a full virtual machine interface to 3038Linux :-). 3039 3040But now you can ignore ALL boot loader code (in arch/ppc/mbxboot). 3041 3042Just make sure your machine specific header file (for instance 3043include/asm-ppc/tqm8xx.h) includes the same definition of the Board 3044Information structure as we define in include/u-boot.h, and make 3045sure that your definition of IMAP_ADDR uses the same value as your 3046U-Boot configuration in CFG_IMMR. 3047 3048 3049Configuring the Linux kernel: 3050----------------------------- 3051 3052No specific requirements for U-Boot. Make sure you have some root 3053device (initial ramdisk, NFS) for your target system. 3054 3055 3056Building a Linux Image: 3057----------------------- 3058 3059With U-Boot, "normal" build targets like "zImage" or "bzImage" are 3060not used. If you use recent kernel source, a new build target 3061"uImage" will exist which automatically builds an image usable by 3062U-Boot. Most older kernels also have support for a "pImage" target, 3063which was introduced for our predecessor project PPCBoot and uses a 3064100% compatible format. 3065 3066Example: 3067 3068 make TQM850L_config 3069 make oldconfig 3070 make dep 3071 make uImage 3072 3073The "uImage" build target uses a special tool (in 'tools/mkimage') to 3074encapsulate a compressed Linux kernel image with header information, 3075CRC32 checksum etc. for use with U-Boot. This is what we are doing: 3076 3077* build a standard "vmlinux" kernel image (in ELF binary format): 3078 3079* convert the kernel into a raw binary image: 3080 3081 ${CROSS_COMPILE}-objcopy -O binary \ 3082 -R .note -R .comment \ 3083 -S vmlinux linux.bin 3084 3085* compress the binary image: 3086 3087 gzip -9 linux.bin 3088 3089* package compressed binary image for U-Boot: 3090 3091 mkimage -A ppc -O linux -T kernel -C gzip \ 3092 -a 0 -e 0 -n "Linux Kernel Image" \ 3093 -d linux.bin.gz uImage 3094 3095 3096The "mkimage" tool can also be used to create ramdisk images for use 3097with U-Boot, either separated from the Linux kernel image, or 3098combined into one file. "mkimage" encapsulates the images with a 64 3099byte header containing information about target architecture, 3100operating system, image type, compression method, entry points, time 3101stamp, CRC32 checksums, etc. 3102 3103"mkimage" can be called in two ways: to verify existing images and 3104print the header information, or to build new images. 3105 3106In the first form (with "-l" option) mkimage lists the information 3107contained in the header of an existing U-Boot image; this includes 3108checksum verification: 3109 3110 tools/mkimage -l image 3111 -l ==> list image header information 3112 3113The second form (with "-d" option) is used to build a U-Boot image 3114from a "data file" which is used as image payload: 3115 3116 tools/mkimage -A arch -O os -T type -C comp -a addr -e ep \ 3117 -n name -d data_file image 3118 -A ==> set architecture to 'arch' 3119 -O ==> set operating system to 'os' 3120 -T ==> set image type to 'type' 3121 -C ==> set compression type 'comp' 3122 -a ==> set load address to 'addr' (hex) 3123 -e ==> set entry point to 'ep' (hex) 3124 -n ==> set image name to 'name' 3125 -d ==> use image data from 'datafile' 3126 3127Right now, all Linux kernels for PowerPC systems use the same load 3128address (0x00000000), but the entry point address depends on the 3129kernel version: 3130 3131- 2.2.x kernels have the entry point at 0x0000000C, 3132- 2.3.x and later kernels have the entry point at 0x00000000. 3133 3134So a typical call to build a U-Boot image would read: 3135 3136 -> tools/mkimage -n '2.4.4 kernel for TQM850L' \ 3137 > -A ppc -O linux -T kernel -C gzip -a 0 -e 0 \ 3138 > -d /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/ppc/coffboot/vmlinux.gz \ 3139 > examples/uImage.TQM850L 3140 Image Name: 2.4.4 kernel for TQM850L 3141 Created: Wed Jul 19 02:34:59 2000 3142 Image Type: PowerPC Linux Kernel Image (gzip compressed) 3143 Data Size: 335725 Bytes = 327.86 kB = 0.32 MB 3144 Load Address: 0x00000000 3145 Entry Point: 0x00000000 3146 3147To verify the contents of the image (or check for corruption): 3148 3149 -> tools/mkimage -l examples/uImage.TQM850L 3150 Image Name: 2.4.4 kernel for TQM850L 3151 Created: Wed Jul 19 02:34:59 2000 3152 Image Type: PowerPC Linux Kernel Image (gzip compressed) 3153 Data Size: 335725 Bytes = 327.86 kB = 0.32 MB 3154 Load Address: 0x00000000 3155 Entry Point: 0x00000000 3156 3157NOTE: for embedded systems where boot time is critical you can trade 3158speed for memory and install an UNCOMPRESSED image instead: this 3159needs more space in Flash, but boots much faster since it does not 3160need to be uncompressed: 3161 3162 -> gunzip /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/ppc/coffboot/vmlinux.gz 3163 -> tools/mkimage -n '2.4.4 kernel for TQM850L' \ 3164 > -A ppc -O linux -T kernel -C none -a 0 -e 0 \ 3165 > -d /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/ppc/coffboot/vmlinux \ 3166 > examples/uImage.TQM850L-uncompressed 3167 Image Name: 2.4.4 kernel for TQM850L 3168 Created: Wed Jul 19 02:34:59 2000 3169 Image Type: PowerPC Linux Kernel Image (uncompressed) 3170 Data Size: 792160 Bytes = 773.59 kB = 0.76 MB 3171 Load Address: 0x00000000 3172 Entry Point: 0x00000000 3173 3174 3175Similar you can build U-Boot images from a 'ramdisk.image.gz' file 3176when your kernel is intended to use an initial ramdisk: 3177 3178 -> tools/mkimage -n 'Simple Ramdisk Image' \ 3179 > -A ppc -O linux -T ramdisk -C gzip \ 3180 > -d /LinuxPPC/images/SIMPLE-ramdisk.image.gz examples/simple-initrd 3181 Image Name: Simple Ramdisk Image 3182 Created: Wed Jan 12 14:01:50 2000 3183 Image Type: PowerPC Linux RAMDisk Image (gzip compressed) 3184 Data Size: 566530 Bytes = 553.25 kB = 0.54 MB 3185 Load Address: 0x00000000 3186 Entry Point: 0x00000000 3187 3188 3189Installing a Linux Image: 3190------------------------- 3191 3192To downloading a U-Boot image over the serial (console) interface, 3193you must convert the image to S-Record format: 3194 3195 objcopy -I binary -O srec examples/image examples/image.srec 3196 3197The 'objcopy' does not understand the information in the U-Boot 3198image header, so the resulting S-Record file will be relative to 3199address 0x00000000. To load it to a given address, you need to 3200specify the target address as 'offset' parameter with the 'loads' 3201command. 3202 3203Example: install the image to address 0x40100000 (which on the 3204TQM8xxL is in the first Flash bank): 3205 3206 => erase 40100000 401FFFFF 3207 3208 .......... done 3209 Erased 8 sectors 3210 3211 => loads 40100000 3212 ## Ready for S-Record download ... 3213 ~>examples/image.srec 3214 1 2 3 4 5 6 7 8 9 10 11 12 13 ... 3215 ... 3216 15989 15990 15991 15992 3217 [file transfer complete] 3218 [connected] 3219 ## Start Addr = 0x00000000 3220 3221 3222You can check the success of the download using the 'iminfo' command; 3223this includes a checksum verification so you can be sure no data 3224corruption happened: 3225 3226 => imi 40100000 3227 3228 ## Checking Image at 40100000 ... 3229 Image Name: 2.2.13 for initrd on TQM850L 3230 Image Type: PowerPC Linux Kernel Image (gzip compressed) 3231 Data Size: 335725 Bytes = 327 kB = 0 MB 3232 Load Address: 00000000 3233 Entry Point: 0000000c 3234 Verifying Checksum ... OK 3235 3236 3237Boot Linux: 3238----------- 3239 3240The "bootm" command is used to boot an application that is stored in 3241memory (RAM or Flash). In case of a Linux kernel image, the contents 3242of the "bootargs" environment variable is passed to the kernel as 3243parameters. You can check and modify this variable using the 3244"printenv" and "setenv" commands: 3245 3246 3247 => printenv bootargs 3248 bootargs=root=/dev/ram 3249 3250 => setenv bootargs root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2 3251 3252 => printenv bootargs 3253 bootargs=root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2 3254 3255 => bootm 40020000 3256 ## Booting Linux kernel at 40020000 ... 3257 Image Name: 2.2.13 for NFS on TQM850L 3258 Image Type: PowerPC Linux Kernel Image (gzip compressed) 3259 Data Size: 381681 Bytes = 372 kB = 0 MB 3260 Load Address: 00000000 3261 Entry Point: 0000000c 3262 Verifying Checksum ... OK 3263 Uncompressing Kernel Image ... OK 3264 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 3265 Boot arguments: root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2 3266 time_init: decrementer frequency = 187500000/60 3267 Calibrating delay loop... 49.77 BogoMIPS 3268 Memory: 15208k available (700k kernel code, 444k data, 32k init) [c0000000,c1000000] 3269 ... 3270 3271If you want to boot a Linux kernel with initial ram disk, you pass 3272the memory addresses of both the kernel and the initrd image (PPBCOOT 3273format!) to the "bootm" command: 3274 3275 => imi 40100000 40200000 3276 3277 ## Checking Image at 40100000 ... 3278 Image Name: 2.2.13 for initrd on TQM850L 3279 Image Type: PowerPC Linux Kernel Image (gzip compressed) 3280 Data Size: 335725 Bytes = 327 kB = 0 MB 3281 Load Address: 00000000 3282 Entry Point: 0000000c 3283 Verifying Checksum ... OK 3284 3285 ## Checking Image at 40200000 ... 3286 Image Name: Simple Ramdisk Image 3287 Image Type: PowerPC Linux RAMDisk Image (gzip compressed) 3288 Data Size: 566530 Bytes = 553 kB = 0 MB 3289 Load Address: 00000000 3290 Entry Point: 00000000 3291 Verifying Checksum ... OK 3292 3293 => bootm 40100000 40200000 3294 ## Booting Linux kernel at 40100000 ... 3295 Image Name: 2.2.13 for initrd on TQM850L 3296 Image Type: PowerPC Linux Kernel Image (gzip compressed) 3297 Data Size: 335725 Bytes = 327 kB = 0 MB 3298 Load Address: 00000000 3299 Entry Point: 0000000c 3300 Verifying Checksum ... OK 3301 Uncompressing Kernel Image ... OK 3302 ## Loading RAMDisk Image at 40200000 ... 3303 Image Name: Simple Ramdisk Image 3304 Image Type: PowerPC Linux RAMDisk Image (gzip compressed) 3305 Data Size: 566530 Bytes = 553 kB = 0 MB 3306 Load Address: 00000000 3307 Entry Point: 00000000 3308 Verifying Checksum ... OK 3309 Loading Ramdisk ... OK 3310 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 3311 Boot arguments: root=/dev/ram 3312 time_init: decrementer frequency = 187500000/60 3313 Calibrating delay loop... 49.77 BogoMIPS 3314 ... 3315 RAMDISK: Compressed image found at block 0 3316 VFS: Mounted root (ext2 filesystem). 3317 3318 bash# 3319 3320Boot Linux and pass a flat device tree: 3321----------- 3322 3323First, U-Boot must be compiled with the appropriate defines. See the section 3324titled "Linux Kernel Interface" above for a more in depth explanation. The 3325following is an example of how to start a kernel and pass an updated 3326flat device tree: 3327 3328=> print oftaddr 3329oftaddr=0x300000 3330=> print oft 3331oft=oftrees/mpc8540ads.dtb 3332=> tftp $oftaddr $oft 3333Speed: 1000, full duplex 3334Using TSEC0 device 3335TFTP from server 192.168.1.1; our IP address is 192.168.1.101 3336Filename 'oftrees/mpc8540ads.dtb'. 3337Load address: 0x300000 3338Loading: # 3339done 3340Bytes transferred = 4106 (100a hex) 3341=> tftp $loadaddr $bootfile 3342Speed: 1000, full duplex 3343Using TSEC0 device 3344TFTP from server 192.168.1.1; our IP address is 192.168.1.2 3345Filename 'uImage'. 3346Load address: 0x200000 3347Loading:############ 3348done 3349Bytes transferred = 1029407 (fb51f hex) 3350=> print loadaddr 3351loadaddr=200000 3352=> print oftaddr 3353oftaddr=0x300000 3354=> bootm $loadaddr - $oftaddr 3355## Booting image at 00200000 ... 3356 Image Name: Linux-2.6.17-dirty 3357 Image Type: PowerPC Linux Kernel Image (gzip compressed) 3358 Data Size: 1029343 Bytes = 1005.2 kB 3359 Load Address: 00000000 3360 Entry Point: 00000000 3361 Verifying Checksum ... OK 3362 Uncompressing Kernel Image ... OK 3363Booting using flat device tree at 0x300000 3364Using MPC85xx ADS machine description 3365Memory CAM mapping: CAM0=256Mb, CAM1=256Mb, CAM2=0Mb residual: 0Mb 3366[snip] 3367 3368 3369More About U-Boot Image Types: 3370------------------------------ 3371 3372U-Boot supports the following image types: 3373 3374 "Standalone Programs" are directly runnable in the environment 3375 provided by U-Boot; it is expected that (if they behave 3376 well) you can continue to work in U-Boot after return from 3377 the Standalone Program. 3378 "OS Kernel Images" are usually images of some Embedded OS which 3379 will take over control completely. Usually these programs 3380 will install their own set of exception handlers, device 3381 drivers, set up the MMU, etc. - this means, that you cannot 3382 expect to re-enter U-Boot except by resetting the CPU. 3383 "RAMDisk Images" are more or less just data blocks, and their 3384 parameters (address, size) are passed to an OS kernel that is 3385 being started. 3386 "Multi-File Images" contain several images, typically an OS 3387 (Linux) kernel image and one or more data images like 3388 RAMDisks. This construct is useful for instance when you want 3389 to boot over the network using BOOTP etc., where the boot 3390 server provides just a single image file, but you want to get 3391 for instance an OS kernel and a RAMDisk image. 3392 3393 "Multi-File Images" start with a list of image sizes, each 3394 image size (in bytes) specified by an "uint32_t" in network 3395 byte order. This list is terminated by an "(uint32_t)0". 3396 Immediately after the terminating 0 follow the images, one by 3397 one, all aligned on "uint32_t" boundaries (size rounded up to 3398 a multiple of 4 bytes). 3399 3400 "Firmware Images" are binary images containing firmware (like 3401 U-Boot or FPGA images) which usually will be programmed to 3402 flash memory. 3403 3404 "Script files" are command sequences that will be executed by 3405 U-Boot's command interpreter; this feature is especially 3406 useful when you configure U-Boot to use a real shell (hush) 3407 as command interpreter. 3408 3409 3410Standalone HOWTO: 3411================= 3412 3413One of the features of U-Boot is that you can dynamically load and 3414run "standalone" applications, which can use some resources of 3415U-Boot like console I/O functions or interrupt services. 3416 3417Two simple examples are included with the sources: 3418 3419"Hello World" Demo: 3420------------------- 3421 3422'examples/hello_world.c' contains a small "Hello World" Demo 3423application; it is automatically compiled when you build U-Boot. 3424It's configured to run at address 0x00040004, so you can play with it 3425like that: 3426 3427 => loads 3428 ## Ready for S-Record download ... 3429 ~>examples/hello_world.srec 3430 1 2 3 4 5 6 7 8 9 10 11 ... 3431 [file transfer complete] 3432 [connected] 3433 ## Start Addr = 0x00040004 3434 3435 => go 40004 Hello World! This is a test. 3436 ## Starting application at 0x00040004 ... 3437 Hello World 3438 argc = 7 3439 argv[0] = "40004" 3440 argv[1] = "Hello" 3441 argv[2] = "World!" 3442 argv[3] = "This" 3443 argv[4] = "is" 3444 argv[5] = "a" 3445 argv[6] = "test." 3446 argv[7] = "<NULL>" 3447 Hit any key to exit ... 3448 3449 ## Application terminated, rc = 0x0 3450 3451Another example, which demonstrates how to register a CPM interrupt 3452handler with the U-Boot code, can be found in 'examples/timer.c'. 3453Here, a CPM timer is set up to generate an interrupt every second. 3454The interrupt service routine is trivial, just printing a '.' 3455character, but this is just a demo program. The application can be 3456controlled by the following keys: 3457 3458 ? - print current values og the CPM Timer registers 3459 b - enable interrupts and start timer 3460 e - stop timer and disable interrupts 3461 q - quit application 3462 3463 => loads 3464 ## Ready for S-Record download ... 3465 ~>examples/timer.srec 3466 1 2 3 4 5 6 7 8 9 10 11 ... 3467 [file transfer complete] 3468 [connected] 3469 ## Start Addr = 0x00040004 3470 3471 => go 40004 3472 ## Starting application at 0x00040004 ... 3473 TIMERS=0xfff00980 3474 Using timer 1 3475 tgcr @ 0xfff00980, tmr @ 0xfff00990, trr @ 0xfff00994, tcr @ 0xfff00998, tcn @ 0xfff0099c, ter @ 0xfff009b0 3476 3477Hit 'b': 3478 [q, b, e, ?] Set interval 1000000 us 3479 Enabling timer 3480Hit '?': 3481 [q, b, e, ?] ........ 3482 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0xef6, ter=0x0 3483Hit '?': 3484 [q, b, e, ?] . 3485 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x2ad4, ter=0x0 3486Hit '?': 3487 [q, b, e, ?] . 3488 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x1efc, ter=0x0 3489Hit '?': 3490 [q, b, e, ?] . 3491 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x169d, ter=0x0 3492Hit 'e': 3493 [q, b, e, ?] ...Stopping timer 3494Hit 'q': 3495 [q, b, e, ?] ## Application terminated, rc = 0x0 3496 3497 3498Minicom warning: 3499================ 3500 3501Over time, many people have reported problems when trying to use the 3502"minicom" terminal emulation program for serial download. I (wd) 3503consider minicom to be broken, and recommend not to use it. Under 3504Unix, I recommend to use C-Kermit for general purpose use (and 3505especially for kermit binary protocol download ("loadb" command), and 3506use "cu" for S-Record download ("loads" command). 3507 3508Nevertheless, if you absolutely want to use it try adding this 3509configuration to your "File transfer protocols" section: 3510 3511 Name Program Name U/D FullScr IO-Red. Multi 3512 X kermit /usr/bin/kermit -i -l %l -s Y U Y N N 3513 Y kermit /usr/bin/kermit -i -l %l -r N D Y N N 3514 3515 3516NetBSD Notes: 3517============= 3518 3519Starting at version 0.9.2, U-Boot supports NetBSD both as host 3520(build U-Boot) and target system (boots NetBSD/mpc8xx). 3521 3522Building requires a cross environment; it is known to work on 3523NetBSD/i386 with the cross-powerpc-netbsd-1.3 package (you will also 3524need gmake since the Makefiles are not compatible with BSD make). 3525Note that the cross-powerpc package does not install include files; 3526attempting to build U-Boot will fail because <machine/ansi.h> is 3527missing. This file has to be installed and patched manually: 3528 3529 # cd /usr/pkg/cross/powerpc-netbsd/include 3530 # mkdir powerpc 3531 # ln -s powerpc machine 3532 # cp /usr/src/sys/arch/powerpc/include/ansi.h powerpc/ansi.h 3533 # ${EDIT} powerpc/ansi.h ## must remove __va_list, _BSD_VA_LIST 3534 3535Native builds *don't* work due to incompatibilities between native 3536and U-Boot include files. 3537 3538Booting assumes that (the first part of) the image booted is a 3539stage-2 loader which in turn loads and then invokes the kernel 3540proper. Loader sources will eventually appear in the NetBSD source 3541tree (probably in sys/arc/mpc8xx/stand/u-boot_stage2/); in the 3542meantime, see ftp://ftp.denx.de/pub/u-boot/ppcboot_stage2.tar.gz 3543 3544 3545Implementation Internals: 3546========================= 3547 3548The following is not intended to be a complete description of every 3549implementation detail. However, it should help to understand the 3550inner workings of U-Boot and make it easier to port it to custom 3551hardware. 3552 3553 3554Initial Stack, Global Data: 3555--------------------------- 3556 3557The implementation of U-Boot is complicated by the fact that U-Boot 3558starts running out of ROM (flash memory), usually without access to 3559system RAM (because the memory controller is not initialized yet). 3560This means that we don't have writable Data or BSS segments, and BSS 3561is not initialized as zero. To be able to get a C environment working 3562at all, we have to allocate at least a minimal stack. Implementation 3563options for this are defined and restricted by the CPU used: Some CPU 3564models provide on-chip memory (like the IMMR area on MPC8xx and 3565MPC826x processors), on others (parts of) the data cache can be 3566locked as (mis-) used as memory, etc. 3567 3568 Chris Hallinan posted a good summary of these issues to the 3569 u-boot-users mailing list: 3570 3571 Subject: RE: [U-Boot-Users] RE: More On Memory Bank x (nothingness)? 3572 From: "Chris Hallinan" <clh@net1plus.com> 3573 Date: Mon, 10 Feb 2003 16:43:46 -0500 (22:43 MET) 3574 ... 3575 3576 Correct me if I'm wrong, folks, but the way I understand it 3577 is this: Using DCACHE as initial RAM for Stack, etc, does not 3578 require any physical RAM backing up the cache. The cleverness 3579 is that the cache is being used as a temporary supply of 3580 necessary storage before the SDRAM controller is setup. It's 3581 beyond the scope of this list to expain the details, but you 3582 can see how this works by studying the cache architecture and 3583 operation in the architecture and processor-specific manuals. 3584 3585 OCM is On Chip Memory, which I believe the 405GP has 4K. It 3586 is another option for the system designer to use as an 3587 initial stack/ram area prior to SDRAM being available. Either 3588 option should work for you. Using CS 4 should be fine if your 3589 board designers haven't used it for something that would 3590 cause you grief during the initial boot! It is frequently not 3591 used. 3592 3593 CFG_INIT_RAM_ADDR should be somewhere that won't interfere 3594 with your processor/board/system design. The default value 3595 you will find in any recent u-boot distribution in 3596 walnut.h should work for you. I'd set it to a value larger 3597 than your SDRAM module. If you have a 64MB SDRAM module, set 3598 it above 400_0000. Just make sure your board has no resources 3599 that are supposed to respond to that address! That code in 3600 start.S has been around a while and should work as is when 3601 you get the config right. 3602 3603 -Chris Hallinan 3604 DS4.COM, Inc. 3605 3606It is essential to remember this, since it has some impact on the C 3607code for the initialization procedures: 3608 3609* Initialized global data (data segment) is read-only. Do not attempt 3610 to write it. 3611 3612* Do not use any unitialized global data (or implicitely initialized 3613 as zero data - BSS segment) at all - this is undefined, initiali- 3614 zation is performed later (when relocating to RAM). 3615 3616* Stack space is very limited. Avoid big data buffers or things like 3617 that. 3618 3619Having only the stack as writable memory limits means we cannot use 3620normal global data to share information beween the code. But it 3621turned out that the implementation of U-Boot can be greatly 3622simplified by making a global data structure (gd_t) available to all 3623functions. We could pass a pointer to this data as argument to _all_ 3624functions, but this would bloat the code. Instead we use a feature of 3625the GCC compiler (Global Register Variables) to share the data: we 3626place a pointer (gd) to the global data into a register which we 3627reserve for this purpose. 3628 3629When choosing a register for such a purpose we are restricted by the 3630relevant (E)ABI specifications for the current architecture, and by 3631GCC's implementation. 3632 3633For PowerPC, the following registers have specific use: 3634 R1: stack pointer 3635 R2: reserved for system use 3636 R3-R4: parameter passing and return values 3637 R5-R10: parameter passing 3638 R13: small data area pointer 3639 R30: GOT pointer 3640 R31: frame pointer 3641 3642 (U-Boot also uses R14 as internal GOT pointer.) 3643 3644 ==> U-Boot will use R2 to hold a pointer to the global data 3645 3646 Note: on PPC, we could use a static initializer (since the 3647 address of the global data structure is known at compile time), 3648 but it turned out that reserving a register results in somewhat 3649 smaller code - although the code savings are not that big (on 3650 average for all boards 752 bytes for the whole U-Boot image, 3651 624 text + 127 data). 3652 3653On Blackfin, the normal C ABI (except for P5) is followed as documented here: 3654 http://docs.blackfin.uclinux.org/doku.php?id=application_binary_interface 3655 3656 ==> U-Boot will use P5 to hold a pointer to the global data 3657 3658On ARM, the following registers are used: 3659 3660 R0: function argument word/integer result 3661 R1-R3: function argument word 3662 R9: GOT pointer 3663 R10: stack limit (used only if stack checking if enabled) 3664 R11: argument (frame) pointer 3665 R12: temporary workspace 3666 R13: stack pointer 3667 R14: link register 3668 R15: program counter 3669 3670 ==> U-Boot will use R8 to hold a pointer to the global data 3671 3672NOTE: DECLARE_GLOBAL_DATA_PTR must be used with file-global scope, 3673or current versions of GCC may "optimize" the code too much. 3674 3675Memory Management: 3676------------------ 3677 3678U-Boot runs in system state and uses physical addresses, i.e. the 3679MMU is not used either for address mapping nor for memory protection. 3680 3681The available memory is mapped to fixed addresses using the memory 3682controller. In this process, a contiguous block is formed for each 3683memory type (Flash, SDRAM, SRAM), even when it consists of several 3684physical memory banks. 3685 3686U-Boot is installed in the first 128 kB of the first Flash bank (on 3687TQM8xxL modules this is the range 0x40000000 ... 0x4001FFFF). After 3688booting and sizing and initializing DRAM, the code relocates itself 3689to the upper end of DRAM. Immediately below the U-Boot code some 3690memory is reserved for use by malloc() [see CFG_MALLOC_LEN 3691configuration setting]. Below that, a structure with global Board 3692Info data is placed, followed by the stack (growing downward). 3693 3694Additionally, some exception handler code is copied to the low 8 kB 3695of DRAM (0x00000000 ... 0x00001FFF). 3696 3697So a typical memory configuration with 16 MB of DRAM could look like 3698this: 3699 3700 0x0000 0000 Exception Vector code 3701 : 3702 0x0000 1FFF 3703 0x0000 2000 Free for Application Use 3704 : 3705 : 3706 3707 : 3708 : 3709 0x00FB FF20 Monitor Stack (Growing downward) 3710 0x00FB FFAC Board Info Data and permanent copy of global data 3711 0x00FC 0000 Malloc Arena 3712 : 3713 0x00FD FFFF 3714 0x00FE 0000 RAM Copy of Monitor Code 3715 ... eventually: LCD or video framebuffer 3716 ... eventually: pRAM (Protected RAM - unchanged by reset) 3717 0x00FF FFFF [End of RAM] 3718 3719 3720System Initialization: 3721---------------------- 3722 3723In the reset configuration, U-Boot starts at the reset entry point 3724(on most PowerPC systens at address 0x00000100). Because of the reset 3725configuration for CS0# this is a mirror of the onboard Flash memory. 3726To be able to re-map memory U-Boot then jumps to its link address. 3727To be able to implement the initialization code in C, a (small!) 3728initial stack is set up in the internal Dual Ported RAM (in case CPUs 3729which provide such a feature like MPC8xx or MPC8260), or in a locked 3730part of the data cache. After that, U-Boot initializes the CPU core, 3731the caches and the SIU. 3732 3733Next, all (potentially) available memory banks are mapped using a 3734preliminary mapping. For example, we put them on 512 MB boundaries 3735(multiples of 0x20000000: SDRAM on 0x00000000 and 0x20000000, Flash 3736on 0x40000000 and 0x60000000, SRAM on 0x80000000). Then UPM A is 3737programmed for SDRAM access. Using the temporary configuration, a 3738simple memory test is run that determines the size of the SDRAM 3739banks. 3740 3741When there is more than one SDRAM bank, and the banks are of 3742different size, the largest is mapped first. For equal size, the first 3743bank (CS2#) is mapped first. The first mapping is always for address 37440x00000000, with any additional banks following immediately to create 3745contiguous memory starting from 0. 3746 3747Then, the monitor installs itself at the upper end of the SDRAM area 3748and allocates memory for use by malloc() and for the global Board 3749Info data; also, the exception vector code is copied to the low RAM 3750pages, and the final stack is set up. 3751 3752Only after this relocation will you have a "normal" C environment; 3753until that you are restricted in several ways, mostly because you are 3754running from ROM, and because the code will have to be relocated to a 3755new address in RAM. 3756 3757 3758U-Boot Porting Guide: 3759---------------------- 3760 3761[Based on messages by Jerry Van Baren in the U-Boot-Users mailing 3762list, October 2002] 3763 3764 3765int main (int argc, char *argv[]) 3766{ 3767 sighandler_t no_more_time; 3768 3769 signal (SIGALRM, no_more_time); 3770 alarm (PROJECT_DEADLINE - toSec (3 * WEEK)); 3771 3772 if (available_money > available_manpower) { 3773 pay consultant to port U-Boot; 3774 return 0; 3775 } 3776 3777 Download latest U-Boot source; 3778 3779 Subscribe to u-boot-users mailing list; 3780 3781 if (clueless) { 3782 email ("Hi, I am new to U-Boot, how do I get started?"); 3783 } 3784 3785 while (learning) { 3786 Read the README file in the top level directory; 3787 Read http://www.denx.de/twiki/bin/view/DULG/Manual ; 3788 Read the source, Luke; 3789 } 3790 3791 if (available_money > toLocalCurrency ($2500)) { 3792 Buy a BDI2000; 3793 } else { 3794 Add a lot of aggravation and time; 3795 } 3796 3797 Create your own board support subdirectory; 3798 3799 Create your own board config file; 3800 3801 while (!running) { 3802 do { 3803 Add / modify source code; 3804 } until (compiles); 3805 Debug; 3806 if (clueless) 3807 email ("Hi, I am having problems..."); 3808 } 3809 Send patch file to Wolfgang; 3810 3811 return 0; 3812} 3813 3814void no_more_time (int sig) 3815{ 3816 hire_a_guru(); 3817} 3818 3819 3820Coding Standards: 3821----------------- 3822 3823All contributions to U-Boot should conform to the Linux kernel 3824coding style; see the file "Documentation/CodingStyle" and the script 3825"scripts/Lindent" in your Linux kernel source directory. In sources 3826originating from U-Boot a style corresponding to "Lindent -pcs" (adding 3827spaces before parameters to function calls) is actually used. 3828 3829Source files originating from a different project (for example the 3830MTD subsystem) are generally exempt from these guidelines and are not 3831reformated to ease subsequent migration to newer versions of those 3832sources. 3833 3834Please note that U-Boot is implemented in C (and to some small parts in 3835Assembler); no C++ is used, so please do not use C++ style comments (//) 3836in your code. 3837 3838Please also stick to the following formatting rules: 3839- remove any trailing white space 3840- use TAB characters for indentation, not spaces 3841- make sure NOT to use DOS '\r\n' line feeds 3842- do not add more than 2 empty lines to source files 3843- do not add trailing empty lines to source files 3844 3845Submissions which do not conform to the standards may be returned 3846with a request to reformat the changes. 3847 3848 3849Submitting Patches: 3850------------------- 3851 3852Since the number of patches for U-Boot is growing, we need to 3853establish some rules. Submissions which do not conform to these rules 3854may be rejected, even when they contain important and valuable stuff. 3855 3856Patches shall be sent to the u-boot-users mailing list. 3857 3858Please see http://www.denx.de/wiki/UBoot/Patches for details. 3859 3860When you send a patch, please include the following information with 3861it: 3862 3863* For bug fixes: a description of the bug and how your patch fixes 3864 this bug. Please try to include a way of demonstrating that the 3865 patch actually fixes something. 3866 3867* For new features: a description of the feature and your 3868 implementation. 3869 3870* A CHANGELOG entry as plaintext (separate from the patch) 3871 3872* For major contributions, your entry to the CREDITS file 3873 3874* When you add support for a new board, don't forget to add this 3875 board to the MAKEALL script, too. 3876 3877* If your patch adds new configuration options, don't forget to 3878 document these in the README file. 3879 3880* The patch itself. If you are using git (which is *strongly* 3881 recommended) you can easily generate the patch using the 3882 "git-format-patch". If you then use "git-send-email" to send it to 3883 the U-Boot mailing list, you will avoid most of the common problems 3884 with some other mail clients. 3885 3886 If you cannot use git, use "diff -purN OLD NEW". If your version of 3887 diff does not support these options, then get the latest version of 3888 GNU diff. 3889 3890 The current directory when running this command shall be the parent 3891 directory of the U-Boot source tree (i. e. please make sure that 3892 your patch includes sufficient directory information for the 3893 affected files). 3894 3895 We prefer patches as plain text. MIME attachments are discouraged, 3896 and compressed attachments must not be used. 3897 3898* If one logical set of modifications affects or creates several 3899 files, all these changes shall be submitted in a SINGLE patch file. 3900 3901* Changesets that contain different, unrelated modifications shall be 3902 submitted as SEPARATE patches, one patch per changeset. 3903 3904 3905Notes: 3906 3907* Before sending the patch, run the MAKEALL script on your patched 3908 source tree and make sure that no errors or warnings are reported 3909 for any of the boards. 3910 3911* Keep your modifications to the necessary minimum: A patch 3912 containing several unrelated changes or arbitrary reformats will be 3913 returned with a request to re-formatting / split it. 3914 3915* If you modify existing code, make sure that your new code does not 3916 add to the memory footprint of the code ;-) Small is beautiful! 3917 When adding new features, these should compile conditionally only 3918 (using #ifdef), and the resulting code with the new feature 3919 disabled must not need more memory than the old code without your 3920 modification. 3921 3922* Remember that there is a size limit of 40 kB per message on the 3923 u-boot-users mailing list. Bigger patches will be moderated. If 3924 they are reasonable and not bigger than 100 kB, they will be 3925 acknowledged. Even bigger patches should be avoided. 3926