1# 2# (C) Copyright 2000 - 2008 3# Wolfgang Denk, DENX Software Engineering, wd@denx.de. 4# 5# See file CREDITS for list of people who contributed to this 6# project. 7# 8# This program is free software; you can redistribute it and/or 9# modify it under the terms of the GNU General Public License as 10# published by the Free Software Foundation; either version 2 of 11# the License, or (at your option) any later version. 12# 13# This program is distributed in the hope that it will be useful, 14# but WITHOUT ANY WARRANTY; without even the implied warranty of 15# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 16# GNU General Public License for more details. 17# 18# You should have received a copy of the GNU General Public License 19# along with this program; if not, write to the Free Software 20# Foundation, Inc., 59 Temple Place, Suite 330, Boston, 21# MA 02111-1307 USA 22# 23 24Summary: 25======== 26 27This directory contains the source code for U-Boot, a boot loader for 28Embedded boards based on PowerPC, ARM, MIPS and several other 29processors, which can be installed in a boot ROM and used to 30initialize and test the hardware or to download and run application 31code. 32 33The development of U-Boot is closely related to Linux: some parts of 34the source code originate in the Linux source tree, we have some 35header files in common, and special provision has been made to 36support booting of Linux images. 37 38Some attention has been paid to make this software easily 39configurable and extendable. For instance, all monitor commands are 40implemented with the same call interface, so that it's very easy to 41add new commands. Also, instead of permanently adding rarely used 42code (for instance hardware test utilities) to the monitor, you can 43load and run it dynamically. 44 45 46Status: 47======= 48 49In general, all boards for which a configuration option exists in the 50Makefile have been tested to some extent and can be considered 51"working". In fact, many of them are used in production systems. 52 53In case of problems see the CHANGELOG and CREDITS files to find out 54who contributed the specific port. The MAINTAINERS file lists board 55maintainers. 56 57 58Where to get help: 59================== 60 61In case you have questions about, problems with or contributions for 62U-Boot you should send a message to the U-Boot mailing list at 63<u-boot-users@lists.sourceforge.net>. There is also an archive of 64previous traffic on the mailing list - please search the archive 65before asking FAQ's. Please see 66http://lists.sourceforge.net/lists/listinfo/u-boot-users/ 67 68 69Where to get source code: 70========================= 71 72The U-Boot source code is maintained in the git repository at 73git://www.denx.de/git/u-boot.git ; you can browse it online at 74http://www.denx.de/cgi-bin/gitweb.cgi?p=u-boot.git;a=summary 75 76The "snapshot" links on this page allow you to download tarballs of 77any version you might be interested in. Ofifcial releases are also 78available for FTP download from the ftp://ftp.denx.de/pub/u-boot/ 79directory. 80 81Pre-built (and tested) images are available from 82ftp://ftp.denx.de/pub/u-boot/images/ 83 84 85Where we come from: 86=================== 87 88- start from 8xxrom sources 89- create PPCBoot project (http://sourceforge.net/projects/ppcboot) 90- clean up code 91- make it easier to add custom boards 92- make it possible to add other [PowerPC] CPUs 93- extend functions, especially: 94 * Provide extended interface to Linux boot loader 95 * S-Record download 96 * network boot 97 * PCMCIA / CompactFLash / ATA disk / SCSI ... boot 98- create ARMBoot project (http://sourceforge.net/projects/armboot) 99- add other CPU families (starting with ARM) 100- create U-Boot project (http://sourceforge.net/projects/u-boot) 101- current project page: see http://www.denx.de/wiki/UBoot 102 103 104Names and Spelling: 105=================== 106 107The "official" name of this project is "Das U-Boot". The spelling 108"U-Boot" shall be used in all written text (documentation, comments 109in source files etc.). Example: 110 111 This is the README file for the U-Boot project. 112 113File names etc. shall be based on the string "u-boot". Examples: 114 115 include/asm-ppc/u-boot.h 116 117 #include <asm/u-boot.h> 118 119Variable names, preprocessor constants etc. shall be either based on 120the string "u_boot" or on "U_BOOT". Example: 121 122 U_BOOT_VERSION u_boot_logo 123 IH_OS_U_BOOT u_boot_hush_start 124 125 126Versioning: 127=========== 128 129U-Boot uses a 3 level version number containing a version, a 130sub-version, and a patchlevel: "U-Boot-2.34.5" means version "2", 131sub-version "34", and patchlevel "4". 132 133The patchlevel is used to indicate certain stages of development 134between released versions, i. e. officially released versions of 135U-Boot will always have a patchlevel of "0". 136 137 138Directory Hierarchy: 139==================== 140 141- board Board dependent files 142- common Misc architecture independent functions 143- cpu CPU specific files 144 - 74xx_7xx Files specific to Freescale MPC74xx and 7xx CPUs 145 - arm720t Files specific to ARM 720 CPUs 146 - arm920t Files specific to ARM 920 CPUs 147 - at91rm9200 Files specific to Atmel AT91RM9200 CPU 148 - imx Files specific to Freescale MC9328 i.MX CPUs 149 - s3c24x0 Files specific to Samsung S3C24X0 CPUs 150 - arm925t Files specific to ARM 925 CPUs 151 - arm926ejs Files specific to ARM 926 CPUs 152 - arm1136 Files specific to ARM 1136 CPUs 153 - at32ap Files specific to Atmel AVR32 AP CPUs 154 - i386 Files specific to i386 CPUs 155 - ixp Files specific to Intel XScale IXP CPUs 156 - mcf52x2 Files specific to Freescale ColdFire MCF52x2 CPUs 157 - mcf5227x Files specific to Freescale ColdFire MCF5227x CPUs 158 - mcf532x Files specific to Freescale ColdFire MCF5329 CPUs 159 - mcf5445x Files specific to Freescale ColdFire MCF5445x CPUs 160 - mcf547x_8x Files specific to Freescale ColdFire MCF547x_8x CPUs 161 - mips Files specific to MIPS CPUs 162 - mpc5xx Files specific to Freescale MPC5xx CPUs 163 - mpc5xxx Files specific to Freescale MPC5xxx CPUs 164 - mpc8xx Files specific to Freescale MPC8xx CPUs 165 - mpc8220 Files specific to Freescale MPC8220 CPUs 166 - mpc824x Files specific to Freescale MPC824x CPUs 167 - mpc8260 Files specific to Freescale MPC8260 CPUs 168 - mpc85xx Files specific to Freescale MPC85xx CPUs 169 - nios Files specific to Altera NIOS CPUs 170 - nios2 Files specific to Altera Nios-II CPUs 171 - ppc4xx Files specific to AMCC PowerPC 4xx CPUs 172 - pxa Files specific to Intel XScale PXA CPUs 173 - s3c44b0 Files specific to Samsung S3C44B0 CPUs 174 - sa1100 Files specific to Intel StrongARM SA1100 CPUs 175- disk Code for disk drive partition handling 176- doc Documentation (don't expect too much) 177- drivers Commonly used device drivers 178- dtt Digital Thermometer and Thermostat drivers 179- examples Example code for standalone applications, etc. 180- include Header Files 181- lib_arm Files generic to ARM architecture 182- lib_avr32 Files generic to AVR32 architecture 183- lib_generic Files generic to all architectures 184- lib_i386 Files generic to i386 architecture 185- lib_m68k Files generic to m68k architecture 186- lib_mips Files generic to MIPS architecture 187- lib_nios Files generic to NIOS architecture 188- lib_ppc Files generic to PowerPC architecture 189- libfdt Library files to support flattened device trees 190- net Networking code 191- post Power On Self Test 192- rtc Real Time Clock drivers 193- tools Tools to build S-Record or U-Boot images, etc. 194 195Software Configuration: 196======================= 197 198Configuration is usually done using C preprocessor defines; the 199rationale behind that is to avoid dead code whenever possible. 200 201There are two classes of configuration variables: 202 203* Configuration _OPTIONS_: 204 These are selectable by the user and have names beginning with 205 "CONFIG_". 206 207* Configuration _SETTINGS_: 208 These depend on the hardware etc. and should not be meddled with if 209 you don't know what you're doing; they have names beginning with 210 "CFG_". 211 212Later we will add a configuration tool - probably similar to or even 213identical to what's used for the Linux kernel. Right now, we have to 214do the configuration by hand, which means creating some symbolic 215links and editing some configuration files. We use the TQM8xxL boards 216as an example here. 217 218 219Selection of Processor Architecture and Board Type: 220--------------------------------------------------- 221 222For all supported boards there are ready-to-use default 223configurations available; just type "make <board_name>_config". 224 225Example: For a TQM823L module type: 226 227 cd u-boot 228 make TQM823L_config 229 230For the Cogent platform, you need to specify the cpu type as well; 231e.g. "make cogent_mpc8xx_config". And also configure the cogent 232directory according to the instructions in cogent/README. 233 234 235Configuration Options: 236---------------------- 237 238Configuration depends on the combination of board and CPU type; all 239such information is kept in a configuration file 240"include/configs/<board_name>.h". 241 242Example: For a TQM823L module, all configuration settings are in 243"include/configs/TQM823L.h". 244 245 246Many of the options are named exactly as the corresponding Linux 247kernel configuration options. The intention is to make it easier to 248build a config tool - later. 249 250 251The following options need to be configured: 252 253- CPU Type: Define exactly one, e.g. CONFIG_MPC85XX. 254 255- Board Type: Define exactly one, e.g. CONFIG_MPC8540ADS. 256 257- CPU Daughterboard Type: (if CONFIG_ATSTK1000 is defined) 258 Define exactly one, e.g. CONFIG_ATSTK1002 259 260- CPU Module Type: (if CONFIG_COGENT is defined) 261 Define exactly one of 262 CONFIG_CMA286_60_OLD 263--- FIXME --- not tested yet: 264 CONFIG_CMA286_60, CONFIG_CMA286_21, CONFIG_CMA286_60P, 265 CONFIG_CMA287_23, CONFIG_CMA287_50 266 267- Motherboard Type: (if CONFIG_COGENT is defined) 268 Define exactly one of 269 CONFIG_CMA101, CONFIG_CMA102 270 271- Motherboard I/O Modules: (if CONFIG_COGENT is defined) 272 Define one or more of 273 CONFIG_CMA302 274 275- Motherboard Options: (if CONFIG_CMA101 or CONFIG_CMA102 are defined) 276 Define one or more of 277 CONFIG_LCD_HEARTBEAT - update a character position on 278 the lcd display every second with 279 a "rotator" |\-/|\-/ 280 281- Board flavour: (if CONFIG_MPC8260ADS is defined) 282 CONFIG_ADSTYPE 283 Possible values are: 284 CFG_8260ADS - original MPC8260ADS 285 CFG_8266ADS - MPC8266ADS 286 CFG_PQ2FADS - PQ2FADS-ZU or PQ2FADS-VR 287 CFG_8272ADS - MPC8272ADS 288 289- MPC824X Family Member (if CONFIG_MPC824X is defined) 290 Define exactly one of 291 CONFIG_MPC8240, CONFIG_MPC8245 292 293- 8xx CPU Options: (if using an MPC8xx cpu) 294 CONFIG_8xx_GCLK_FREQ - deprecated: CPU clock if 295 get_gclk_freq() cannot work 296 e.g. if there is no 32KHz 297 reference PIT/RTC clock 298 CONFIG_8xx_OSCLK - PLL input clock (either EXTCLK 299 or XTAL/EXTAL) 300 301- 859/866/885 CPU options: (if using a MPC859 or MPC866 or MPC885 CPU): 302 CFG_8xx_CPUCLK_MIN 303 CFG_8xx_CPUCLK_MAX 304 CONFIG_8xx_CPUCLK_DEFAULT 305 See doc/README.MPC866 306 307 CFG_MEASURE_CPUCLK 308 309 Define this to measure the actual CPU clock instead 310 of relying on the correctness of the configured 311 values. Mostly useful for board bringup to make sure 312 the PLL is locked at the intended frequency. Note 313 that this requires a (stable) reference clock (32 kHz 314 RTC clock or CFG_8XX_XIN) 315 316- Intel Monahans options: 317 CFG_MONAHANS_RUN_MODE_OSC_RATIO 318 319 Defines the Monahans run mode to oscillator 320 ratio. Valid values are 8, 16, 24, 31. The core 321 frequency is this value multiplied by 13 MHz. 322 323 CFG_MONAHANS_TURBO_RUN_MODE_RATIO 324 325 Defines the Monahans turbo mode to oscillator 326 ratio. Valid values are 1 (default if undefined) and 327 2. The core frequency as calculated above is multiplied 328 by this value. 329 330- Linux Kernel Interface: 331 CONFIG_CLOCKS_IN_MHZ 332 333 U-Boot stores all clock information in Hz 334 internally. For binary compatibility with older Linux 335 kernels (which expect the clocks passed in the 336 bd_info data to be in MHz) the environment variable 337 "clocks_in_mhz" can be defined so that U-Boot 338 converts clock data to MHZ before passing it to the 339 Linux kernel. 340 When CONFIG_CLOCKS_IN_MHZ is defined, a definition of 341 "clocks_in_mhz=1" is automatically included in the 342 default environment. 343 344 CONFIG_MEMSIZE_IN_BYTES [relevant for MIPS only] 345 346 When transfering memsize parameter to linux, some versions 347 expect it to be in bytes, others in MB. 348 Define CONFIG_MEMSIZE_IN_BYTES to make it in bytes. 349 350 CONFIG_OF_LIBFDT / CONFIG_OF_FLAT_TREE 351 352 New kernel versions are expecting firmware settings to be 353 passed using flattened device trees (based on open firmware 354 concepts). 355 356 CONFIG_OF_LIBFDT 357 * New libfdt-based support 358 * Adds the "fdt" command 359 * The bootm command automatically updates the fdt 360 361 CONFIG_OF_FLAT_TREE 362 * Deprecated, see CONFIG_OF_LIBFDT 363 * Original ft_build.c-based support 364 * Automatically modifies the dft as part of the bootm command 365 * The environment variable "disable_of", when set, 366 disables this functionality. 367 368 OF_CPU - The proper name of the cpus node. 369 OF_SOC - The proper name of the soc node. 370 OF_TBCLK - The timebase frequency. 371 OF_STDOUT_PATH - The path to the console device 372 373 boards with QUICC Engines require OF_QE to set UCC mac addresses 374 375 CONFIG_OF_BOARD_SETUP 376 377 Board code has addition modification that it wants to make 378 to the flat device tree before handing it off to the kernel 379 380 CONFIG_OF_BOOT_CPU 381 382 This define fills in the correct boot cpu in the boot 383 param header, the default value is zero if undefined. 384 385- Serial Ports: 386 CFG_PL010_SERIAL 387 388 Define this if you want support for Amba PrimeCell PL010 UARTs. 389 390 CFG_PL011_SERIAL 391 392 Define this if you want support for Amba PrimeCell PL011 UARTs. 393 394 CONFIG_PL011_CLOCK 395 396 If you have Amba PrimeCell PL011 UARTs, set this variable to 397 the clock speed of the UARTs. 398 399 CONFIG_PL01x_PORTS 400 401 If you have Amba PrimeCell PL010 or PL011 UARTs on your board, 402 define this to a list of base addresses for each (supported) 403 port. See e.g. include/configs/versatile.h 404 405 406- Console Interface: 407 Depending on board, define exactly one serial port 408 (like CONFIG_8xx_CONS_SMC1, CONFIG_8xx_CONS_SMC2, 409 CONFIG_8xx_CONS_SCC1, ...), or switch off the serial 410 console by defining CONFIG_8xx_CONS_NONE 411 412 Note: if CONFIG_8xx_CONS_NONE is defined, the serial 413 port routines must be defined elsewhere 414 (i.e. serial_init(), serial_getc(), ...) 415 416 CONFIG_CFB_CONSOLE 417 Enables console device for a color framebuffer. Needs following 418 defines (cf. smiLynxEM, i8042, board/eltec/bab7xx) 419 VIDEO_FB_LITTLE_ENDIAN graphic memory organisation 420 (default big endian) 421 VIDEO_HW_RECTFILL graphic chip supports 422 rectangle fill 423 (cf. smiLynxEM) 424 VIDEO_HW_BITBLT graphic chip supports 425 bit-blit (cf. smiLynxEM) 426 VIDEO_VISIBLE_COLS visible pixel columns 427 (cols=pitch) 428 VIDEO_VISIBLE_ROWS visible pixel rows 429 VIDEO_PIXEL_SIZE bytes per pixel 430 VIDEO_DATA_FORMAT graphic data format 431 (0-5, cf. cfb_console.c) 432 VIDEO_FB_ADRS framebuffer address 433 VIDEO_KBD_INIT_FCT keyboard int fct 434 (i.e. i8042_kbd_init()) 435 VIDEO_TSTC_FCT test char fct 436 (i.e. i8042_tstc) 437 VIDEO_GETC_FCT get char fct 438 (i.e. i8042_getc) 439 CONFIG_CONSOLE_CURSOR cursor drawing on/off 440 (requires blink timer 441 cf. i8042.c) 442 CFG_CONSOLE_BLINK_COUNT blink interval (cf. i8042.c) 443 CONFIG_CONSOLE_TIME display time/date info in 444 upper right corner 445 (requires CONFIG_CMD_DATE) 446 CONFIG_VIDEO_LOGO display Linux logo in 447 upper left corner 448 CONFIG_VIDEO_BMP_LOGO use bmp_logo.h instead of 449 linux_logo.h for logo. 450 Requires CONFIG_VIDEO_LOGO 451 CONFIG_CONSOLE_EXTRA_INFO 452 addional board info beside 453 the logo 454 455 When CONFIG_CFB_CONSOLE is defined, video console is 456 default i/o. Serial console can be forced with 457 environment 'console=serial'. 458 459 When CONFIG_SILENT_CONSOLE is defined, all console 460 messages (by U-Boot and Linux!) can be silenced with 461 the "silent" environment variable. See 462 doc/README.silent for more information. 463 464- Console Baudrate: 465 CONFIG_BAUDRATE - in bps 466 Select one of the baudrates listed in 467 CFG_BAUDRATE_TABLE, see below. 468 CFG_BRGCLK_PRESCALE, baudrate prescale 469 470- Interrupt driven serial port input: 471 CONFIG_SERIAL_SOFTWARE_FIFO 472 473 PPC405GP only. 474 Use an interrupt handler for receiving data on the 475 serial port. It also enables using hardware handshake 476 (RTS/CTS) and UART's built-in FIFO. Set the number of 477 bytes the interrupt driven input buffer should have. 478 479 Leave undefined to disable this feature, including 480 disable the buffer and hardware handshake. 481 482- Console UART Number: 483 CONFIG_UART1_CONSOLE 484 485 AMCC PPC4xx only. 486 If defined internal UART1 (and not UART0) is used 487 as default U-Boot console. 488 489- Boot Delay: CONFIG_BOOTDELAY - in seconds 490 Delay before automatically booting the default image; 491 set to -1 to disable autoboot. 492 493 See doc/README.autoboot for these options that 494 work with CONFIG_BOOTDELAY. None are required. 495 CONFIG_BOOT_RETRY_TIME 496 CONFIG_BOOT_RETRY_MIN 497 CONFIG_AUTOBOOT_KEYED 498 CONFIG_AUTOBOOT_PROMPT 499 CONFIG_AUTOBOOT_DELAY_STR 500 CONFIG_AUTOBOOT_STOP_STR 501 CONFIG_AUTOBOOT_DELAY_STR2 502 CONFIG_AUTOBOOT_STOP_STR2 503 CONFIG_ZERO_BOOTDELAY_CHECK 504 CONFIG_RESET_TO_RETRY 505 506- Autoboot Command: 507 CONFIG_BOOTCOMMAND 508 Only needed when CONFIG_BOOTDELAY is enabled; 509 define a command string that is automatically executed 510 when no character is read on the console interface 511 within "Boot Delay" after reset. 512 513 CONFIG_BOOTARGS 514 This can be used to pass arguments to the bootm 515 command. The value of CONFIG_BOOTARGS goes into the 516 environment value "bootargs". 517 518 CONFIG_RAMBOOT and CONFIG_NFSBOOT 519 The value of these goes into the environment as 520 "ramboot" and "nfsboot" respectively, and can be used 521 as a convenience, when switching between booting from 522 ram and nfs. 523 524- Pre-Boot Commands: 525 CONFIG_PREBOOT 526 527 When this option is #defined, the existence of the 528 environment variable "preboot" will be checked 529 immediately before starting the CONFIG_BOOTDELAY 530 countdown and/or running the auto-boot command resp. 531 entering interactive mode. 532 533 This feature is especially useful when "preboot" is 534 automatically generated or modified. For an example 535 see the LWMON board specific code: here "preboot" is 536 modified when the user holds down a certain 537 combination of keys on the (special) keyboard when 538 booting the systems 539 540- Serial Download Echo Mode: 541 CONFIG_LOADS_ECHO 542 If defined to 1, all characters received during a 543 serial download (using the "loads" command) are 544 echoed back. This might be needed by some terminal 545 emulations (like "cu"), but may as well just take 546 time on others. This setting #define's the initial 547 value of the "loads_echo" environment variable. 548 549- Kgdb Serial Baudrate: (if CONFIG_CMD_KGDB is defined) 550 CONFIG_KGDB_BAUDRATE 551 Select one of the baudrates listed in 552 CFG_BAUDRATE_TABLE, see below. 553 554- Monitor Functions: 555 Monitor commands can be included or excluded 556 from the build by using the #include files 557 "config_cmd_all.h" and #undef'ing unwanted 558 commands, or using "config_cmd_default.h" 559 and augmenting with additional #define's 560 for wanted commands. 561 562 The default command configuration includes all commands 563 except those marked below with a "*". 564 565 CONFIG_CMD_ASKENV * ask for env variable 566 CONFIG_CMD_AUTOSCRIPT Autoscript Support 567 CONFIG_CMD_BDI bdinfo 568 CONFIG_CMD_BEDBUG * Include BedBug Debugger 569 CONFIG_CMD_BMP * BMP support 570 CONFIG_CMD_BSP * Board specific commands 571 CONFIG_CMD_BOOTD bootd 572 CONFIG_CMD_CACHE * icache, dcache 573 CONFIG_CMD_CONSOLE coninfo 574 CONFIG_CMD_DATE * support for RTC, date/time... 575 CONFIG_CMD_DHCP * DHCP support 576 CONFIG_CMD_DIAG * Diagnostics 577 CONFIG_CMD_DOC * Disk-On-Chip Support 578 CONFIG_CMD_DTT * Digital Therm and Thermostat 579 CONFIG_CMD_ECHO echo arguments 580 CONFIG_CMD_EEPROM * EEPROM read/write support 581 CONFIG_CMD_ELF * bootelf, bootvx 582 CONFIG_CMD_ENV saveenv 583 CONFIG_CMD_FDC * Floppy Disk Support 584 CONFIG_CMD_FAT * FAT partition support 585 CONFIG_CMD_FDOS * Dos diskette Support 586 CONFIG_CMD_FLASH flinfo, erase, protect 587 CONFIG_CMD_FPGA FPGA device initialization support 588 CONFIG_CMD_HWFLOW * RTS/CTS hw flow control 589 CONFIG_CMD_I2C * I2C serial bus support 590 CONFIG_CMD_IDE * IDE harddisk support 591 CONFIG_CMD_IMI iminfo 592 CONFIG_CMD_IMLS List all found images 593 CONFIG_CMD_IMMAP * IMMR dump support 594 CONFIG_CMD_IRQ * irqinfo 595 CONFIG_CMD_ITEST Integer/string test of 2 values 596 CONFIG_CMD_JFFS2 * JFFS2 Support 597 CONFIG_CMD_KGDB * kgdb 598 CONFIG_CMD_LOADB loadb 599 CONFIG_CMD_LOADS loads 600 CONFIG_CMD_MEMORY md, mm, nm, mw, cp, cmp, crc, base, 601 loop, loopw, mtest 602 CONFIG_CMD_MISC Misc functions like sleep etc 603 CONFIG_CMD_MMC * MMC memory mapped support 604 CONFIG_CMD_MII * MII utility commands 605 CONFIG_CMD_NAND * NAND support 606 CONFIG_CMD_NET bootp, tftpboot, rarpboot 607 CONFIG_CMD_PCI * pciinfo 608 CONFIG_CMD_PCMCIA * PCMCIA support 609 CONFIG_CMD_PING * send ICMP ECHO_REQUEST to network 610 host 611 CONFIG_CMD_PORTIO * Port I/O 612 CONFIG_CMD_REGINFO * Register dump 613 CONFIG_CMD_RUN run command in env variable 614 CONFIG_CMD_SAVES * save S record dump 615 CONFIG_CMD_SCSI * SCSI Support 616 CONFIG_CMD_SDRAM * print SDRAM configuration information 617 (requires CONFIG_CMD_I2C) 618 CONFIG_CMD_SETGETDCR Support for DCR Register access 619 (4xx only) 620 CONFIG_CMD_SPI * SPI serial bus support 621 CONFIG_CMD_USB * USB support 622 CONFIG_CMD_VFD * VFD support (TRAB) 623 CONFIG_CMD_BSP * Board SPecific functions 624 CONFIG_CMD_CDP * Cisco Discover Protocol support 625 CONFIG_CMD_FSL * Microblaze FSL support 626 627 628 EXAMPLE: If you want all functions except of network 629 support you can write: 630 631 #include "config_cmd_all.h" 632 #undef CONFIG_CMD_NET 633 634 Other Commands: 635 fdt (flattened device tree) command: CONFIG_OF_LIBFDT 636 637 Note: Don't enable the "icache" and "dcache" commands 638 (configuration option CONFIG_CMD_CACHE) unless you know 639 what you (and your U-Boot users) are doing. Data 640 cache cannot be enabled on systems like the 8xx or 641 8260 (where accesses to the IMMR region must be 642 uncached), and it cannot be disabled on all other 643 systems where we (mis-) use the data cache to hold an 644 initial stack and some data. 645 646 647 XXX - this list needs to get updated! 648 649- Watchdog: 650 CONFIG_WATCHDOG 651 If this variable is defined, it enables watchdog 652 support. There must be support in the platform specific 653 code for a watchdog. For the 8xx and 8260 CPUs, the 654 SIU Watchdog feature is enabled in the SYPCR 655 register. 656 657- U-Boot Version: 658 CONFIG_VERSION_VARIABLE 659 If this variable is defined, an environment variable 660 named "ver" is created by U-Boot showing the U-Boot 661 version as printed by the "version" command. 662 This variable is readonly. 663 664- Real-Time Clock: 665 666 When CONFIG_CMD_DATE is selected, the type of the RTC 667 has to be selected, too. Define exactly one of the 668 following options: 669 670 CONFIG_RTC_MPC8xx - use internal RTC of MPC8xx 671 CONFIG_RTC_PCF8563 - use Philips PCF8563 RTC 672 CONFIG_RTC_MC146818 - use MC146818 RTC 673 CONFIG_RTC_DS1307 - use Maxim, Inc. DS1307 RTC 674 CONFIG_RTC_DS1337 - use Maxim, Inc. DS1337 RTC 675 CONFIG_RTC_DS1338 - use Maxim, Inc. DS1338 RTC 676 CONFIG_RTC_DS164x - use Dallas DS164x RTC 677 CONFIG_RTC_ISL1208 - use Intersil ISL1208 RTC 678 CONFIG_RTC_MAX6900 - use Maxim, Inc. MAX6900 RTC 679 CFG_RTC_DS1337_NOOSC - Turn off the OSC output for DS1337 680 681 Note that if the RTC uses I2C, then the I2C interface 682 must also be configured. See I2C Support, below. 683 684- Timestamp Support: 685 686 When CONFIG_TIMESTAMP is selected, the timestamp 687 (date and time) of an image is printed by image 688 commands like bootm or iminfo. This option is 689 automatically enabled when you select CONFIG_CMD_DATE . 690 691- Partition Support: 692 CONFIG_MAC_PARTITION and/or CONFIG_DOS_PARTITION 693 and/or CONFIG_ISO_PARTITION 694 695 If IDE or SCSI support is enabled (CONFIG_CMD_IDE or 696 CONFIG_CMD_SCSI) you must configure support for at 697 least one partition type as well. 698 699- IDE Reset method: 700 CONFIG_IDE_RESET_ROUTINE - this is defined in several 701 board configurations files but used nowhere! 702 703 CONFIG_IDE_RESET - is this is defined, IDE Reset will 704 be performed by calling the function 705 ide_set_reset(int reset) 706 which has to be defined in a board specific file 707 708- ATAPI Support: 709 CONFIG_ATAPI 710 711 Set this to enable ATAPI support. 712 713- LBA48 Support 714 CONFIG_LBA48 715 716 Set this to enable support for disks larger than 137GB 717 Also look at CFG_64BIT_LBA ,CFG_64BIT_VSPRINTF and CFG_64BIT_STRTOUL 718 Whithout these , LBA48 support uses 32bit variables and will 'only' 719 support disks up to 2.1TB. 720 721 CFG_64BIT_LBA: 722 When enabled, makes the IDE subsystem use 64bit sector addresses. 723 Default is 32bit. 724 725- SCSI Support: 726 At the moment only there is only support for the 727 SYM53C8XX SCSI controller; define 728 CONFIG_SCSI_SYM53C8XX to enable it. 729 730 CFG_SCSI_MAX_LUN [8], CFG_SCSI_MAX_SCSI_ID [7] and 731 CFG_SCSI_MAX_DEVICE [CFG_SCSI_MAX_SCSI_ID * 732 CFG_SCSI_MAX_LUN] can be adjusted to define the 733 maximum numbers of LUNs, SCSI ID's and target 734 devices. 735 CFG_SCSI_SYM53C8XX_CCF to fix clock timing (80Mhz) 736 737- NETWORK Support (PCI): 738 CONFIG_E1000 739 Support for Intel 8254x gigabit chips. 740 741 CONFIG_E1000_FALLBACK_MAC 742 default MAC for empty eeprom after production. 743 744 CONFIG_EEPRO100 745 Support for Intel 82557/82559/82559ER chips. 746 Optional CONFIG_EEPRO100_SROM_WRITE enables eeprom 747 write routine for first time initialisation. 748 749 CONFIG_TULIP 750 Support for Digital 2114x chips. 751 Optional CONFIG_TULIP_SELECT_MEDIA for board specific 752 modem chip initialisation (KS8761/QS6611). 753 754 CONFIG_NATSEMI 755 Support for National dp83815 chips. 756 757 CONFIG_NS8382X 758 Support for National dp8382[01] gigabit chips. 759 760- NETWORK Support (other): 761 762 CONFIG_DRIVER_LAN91C96 763 Support for SMSC's LAN91C96 chips. 764 765 CONFIG_LAN91C96_BASE 766 Define this to hold the physical address 767 of the LAN91C96's I/O space 768 769 CONFIG_LAN91C96_USE_32_BIT 770 Define this to enable 32 bit addressing 771 772 CONFIG_DRIVER_SMC91111 773 Support for SMSC's LAN91C111 chip 774 775 CONFIG_SMC91111_BASE 776 Define this to hold the physical address 777 of the device (I/O space) 778 779 CONFIG_SMC_USE_32_BIT 780 Define this if data bus is 32 bits 781 782 CONFIG_SMC_USE_IOFUNCS 783 Define this to use i/o functions instead of macros 784 (some hardware wont work with macros) 785 786- USB Support: 787 At the moment only the UHCI host controller is 788 supported (PIP405, MIP405, MPC5200); define 789 CONFIG_USB_UHCI to enable it. 790 define CONFIG_USB_KEYBOARD to enable the USB Keyboard 791 and define CONFIG_USB_STORAGE to enable the USB 792 storage devices. 793 Note: 794 Supported are USB Keyboards and USB Floppy drives 795 (TEAC FD-05PUB). 796 MPC5200 USB requires additional defines: 797 CONFIG_USB_CLOCK 798 for 528 MHz Clock: 0x0001bbbb 799 CONFIG_USB_CONFIG 800 for differential drivers: 0x00001000 801 for single ended drivers: 0x00005000 802 CFG_USB_EVENT_POLL 803 May be defined to allow interrupt polling 804 instead of using asynchronous interrupts 805 806- USB Device: 807 Define the below if you wish to use the USB console. 808 Once firmware is rebuilt from a serial console issue the 809 command "setenv stdin usbtty; setenv stdout usbtty" and 810 attach your usb cable. The Unix command "dmesg" should print 811 it has found a new device. The environment variable usbtty 812 can be set to gserial or cdc_acm to enable your device to 813 appear to a USB host as a Linux gserial device or a 814 Common Device Class Abstract Control Model serial device. 815 If you select usbtty = gserial you should be able to enumerate 816 a Linux host by 817 # modprobe usbserial vendor=0xVendorID product=0xProductID 818 else if using cdc_acm, simply setting the environment 819 variable usbtty to be cdc_acm should suffice. The following 820 might be defined in YourBoardName.h 821 822 CONFIG_USB_DEVICE 823 Define this to build a UDC device 824 825 CONFIG_USB_TTY 826 Define this to have a tty type of device available to 827 talk to the UDC device 828 829 CFG_CONSOLE_IS_IN_ENV 830 Define this if you want stdin, stdout &/or stderr to 831 be set to usbtty. 832 833 mpc8xx: 834 CFG_USB_EXTC_CLK 0xBLAH 835 Derive USB clock from external clock "blah" 836 - CFG_USB_EXTC_CLK 0x02 837 838 CFG_USB_BRG_CLK 0xBLAH 839 Derive USB clock from brgclk 840 - CFG_USB_BRG_CLK 0x04 841 842 If you have a USB-IF assigned VendorID then you may wish to 843 define your own vendor specific values either in BoardName.h 844 or directly in usbd_vendor_info.h. If you don't define 845 CONFIG_USBD_MANUFACTURER, CONFIG_USBD_PRODUCT_NAME, 846 CONFIG_USBD_VENDORID and CONFIG_USBD_PRODUCTID, then U-Boot 847 should pretend to be a Linux device to it's target host. 848 849 CONFIG_USBD_MANUFACTURER 850 Define this string as the name of your company for 851 - CONFIG_USBD_MANUFACTURER "my company" 852 853 CONFIG_USBD_PRODUCT_NAME 854 Define this string as the name of your product 855 - CONFIG_USBD_PRODUCT_NAME "acme usb device" 856 857 CONFIG_USBD_VENDORID 858 Define this as your assigned Vendor ID from the USB 859 Implementors Forum. This *must* be a genuine Vendor ID 860 to avoid polluting the USB namespace. 861 - CONFIG_USBD_VENDORID 0xFFFF 862 863 CONFIG_USBD_PRODUCTID 864 Define this as the unique Product ID 865 for your device 866 - CONFIG_USBD_PRODUCTID 0xFFFF 867 868 869- MMC Support: 870 The MMC controller on the Intel PXA is supported. To 871 enable this define CONFIG_MMC. The MMC can be 872 accessed from the boot prompt by mapping the device 873 to physical memory similar to flash. Command line is 874 enabled with CONFIG_CMD_MMC. The MMC driver also works with 875 the FAT fs. This is enabled with CONFIG_CMD_FAT. 876 877- Journaling Flash filesystem support: 878 CONFIG_JFFS2_NAND, CONFIG_JFFS2_NAND_OFF, CONFIG_JFFS2_NAND_SIZE, 879 CONFIG_JFFS2_NAND_DEV 880 Define these for a default partition on a NAND device 881 882 CFG_JFFS2_FIRST_SECTOR, 883 CFG_JFFS2_FIRST_BANK, CFG_JFFS2_NUM_BANKS 884 Define these for a default partition on a NOR device 885 886 CFG_JFFS_CUSTOM_PART 887 Define this to create an own partition. You have to provide a 888 function struct part_info* jffs2_part_info(int part_num) 889 890 If you define only one JFFS2 partition you may also want to 891 #define CFG_JFFS_SINGLE_PART 1 892 to disable the command chpart. This is the default when you 893 have not defined a custom partition 894 895- Keyboard Support: 896 CONFIG_ISA_KEYBOARD 897 898 Define this to enable standard (PC-Style) keyboard 899 support 900 901 CONFIG_I8042_KBD 902 Standard PC keyboard driver with US (is default) and 903 GERMAN key layout (switch via environment 'keymap=de') support. 904 Export function i8042_kbd_init, i8042_tstc and i8042_getc 905 for cfb_console. Supports cursor blinking. 906 907- Video support: 908 CONFIG_VIDEO 909 910 Define this to enable video support (for output to 911 video). 912 913 CONFIG_VIDEO_CT69000 914 915 Enable Chips & Technologies 69000 Video chip 916 917 CONFIG_VIDEO_SMI_LYNXEM 918 Enable Silicon Motion SMI 712/710/810 Video chip. The 919 video output is selected via environment 'videoout' 920 (1 = LCD and 2 = CRT). If videoout is undefined, CRT is 921 assumed. 922 923 For the CT69000 and SMI_LYNXEM drivers, videomode is 924 selected via environment 'videomode'. Two diferent ways 925 are possible: 926 - "videomode=num" 'num' is a standard LiLo mode numbers. 927 Following standard modes are supported (* is default): 928 929 Colors 640x480 800x600 1024x768 1152x864 1280x1024 930 -------------+--------------------------------------------- 931 8 bits | 0x301* 0x303 0x305 0x161 0x307 932 15 bits | 0x310 0x313 0x316 0x162 0x319 933 16 bits | 0x311 0x314 0x317 0x163 0x31A 934 24 bits | 0x312 0x315 0x318 ? 0x31B 935 -------------+--------------------------------------------- 936 (i.e. setenv videomode 317; saveenv; reset;) 937 938 - "videomode=bootargs" all the video parameters are parsed 939 from the bootargs. (See drivers/video/videomodes.c) 940 941 942 CONFIG_VIDEO_SED13806 943 Enable Epson SED13806 driver. This driver supports 8bpp 944 and 16bpp modes defined by CONFIG_VIDEO_SED13806_8BPP 945 or CONFIG_VIDEO_SED13806_16BPP 946 947- Keyboard Support: 948 CONFIG_KEYBOARD 949 950 Define this to enable a custom keyboard support. 951 This simply calls drv_keyboard_init() which must be 952 defined in your board-specific files. 953 The only board using this so far is RBC823. 954 955- LCD Support: CONFIG_LCD 956 957 Define this to enable LCD support (for output to LCD 958 display); also select one of the supported displays 959 by defining one of these: 960 961 CONFIG_NEC_NL6448AC33: 962 963 NEC NL6448AC33-18. Active, color, single scan. 964 965 CONFIG_NEC_NL6448BC20 966 967 NEC NL6448BC20-08. 6.5", 640x480. 968 Active, color, single scan. 969 970 CONFIG_NEC_NL6448BC33_54 971 972 NEC NL6448BC33-54. 10.4", 640x480. 973 Active, color, single scan. 974 975 CONFIG_SHARP_16x9 976 977 Sharp 320x240. Active, color, single scan. 978 It isn't 16x9, and I am not sure what it is. 979 980 CONFIG_SHARP_LQ64D341 981 982 Sharp LQ64D341 display, 640x480. 983 Active, color, single scan. 984 985 CONFIG_HLD1045 986 987 HLD1045 display, 640x480. 988 Active, color, single scan. 989 990 CONFIG_OPTREX_BW 991 992 Optrex CBL50840-2 NF-FW 99 22 M5 993 or 994 Hitachi LMG6912RPFC-00T 995 or 996 Hitachi SP14Q002 997 998 320x240. Black & white. 999 1000 Normally display is black on white background; define 1001 CFG_WHITE_ON_BLACK to get it inverted. 1002 1003- Splash Screen Support: CONFIG_SPLASH_SCREEN 1004 1005 If this option is set, the environment is checked for 1006 a variable "splashimage". If found, the usual display 1007 of logo, copyright and system information on the LCD 1008 is suppressed and the BMP image at the address 1009 specified in "splashimage" is loaded instead. The 1010 console is redirected to the "nulldev", too. This 1011 allows for a "silent" boot where a splash screen is 1012 loaded very quickly after power-on. 1013 1014- Gzip compressed BMP image support: CONFIG_VIDEO_BMP_GZIP 1015 1016 If this option is set, additionally to standard BMP 1017 images, gzipped BMP images can be displayed via the 1018 splashscreen support or the bmp command. 1019 1020- Compression support: 1021 CONFIG_BZIP2 1022 1023 If this option is set, support for bzip2 compressed 1024 images is included. If not, only uncompressed and gzip 1025 compressed images are supported. 1026 1027 NOTE: the bzip2 algorithm requires a lot of RAM, so 1028 the malloc area (as defined by CFG_MALLOC_LEN) should 1029 be at least 4MB. 1030 1031- MII/PHY support: 1032 CONFIG_PHY_ADDR 1033 1034 The address of PHY on MII bus. 1035 1036 CONFIG_PHY_CLOCK_FREQ (ppc4xx) 1037 1038 The clock frequency of the MII bus 1039 1040 CONFIG_PHY_GIGE 1041 1042 If this option is set, support for speed/duplex 1043 detection of Gigabit PHY is included. 1044 1045 CONFIG_PHY_RESET_DELAY 1046 1047 Some PHY like Intel LXT971A need extra delay after 1048 reset before any MII register access is possible. 1049 For such PHY, set this option to the usec delay 1050 required. (minimum 300usec for LXT971A) 1051 1052 CONFIG_PHY_CMD_DELAY (ppc4xx) 1053 1054 Some PHY like Intel LXT971A need extra delay after 1055 command issued before MII status register can be read 1056 1057- Ethernet address: 1058 CONFIG_ETHADDR 1059 CONFIG_ETH2ADDR 1060 CONFIG_ETH3ADDR 1061 1062 Define a default value for ethernet address to use 1063 for the respective ethernet interface, in case this 1064 is not determined automatically. 1065 1066- IP address: 1067 CONFIG_IPADDR 1068 1069 Define a default value for the IP address to use for 1070 the default ethernet interface, in case this is not 1071 determined through e.g. bootp. 1072 1073- Server IP address: 1074 CONFIG_SERVERIP 1075 1076 Defines a default value for theIP address of a TFTP 1077 server to contact when using the "tftboot" command. 1078 1079- Multicast TFTP Mode: 1080 CONFIG_MCAST_TFTP 1081 1082 Defines whether you want to support multicast TFTP as per 1083 rfc-2090; for example to work with atftp. Lets lots of targets 1084 tftp down the same boot image concurrently. Note: the ethernet 1085 driver in use must provide a function: mcast() to join/leave a 1086 multicast group. 1087 1088 CONFIG_BOOTP_RANDOM_DELAY 1089- BOOTP Recovery Mode: 1090 CONFIG_BOOTP_RANDOM_DELAY 1091 1092 If you have many targets in a network that try to 1093 boot using BOOTP, you may want to avoid that all 1094 systems send out BOOTP requests at precisely the same 1095 moment (which would happen for instance at recovery 1096 from a power failure, when all systems will try to 1097 boot, thus flooding the BOOTP server. Defining 1098 CONFIG_BOOTP_RANDOM_DELAY causes a random delay to be 1099 inserted before sending out BOOTP requests. The 1100 following delays are inserted then: 1101 1102 1st BOOTP request: delay 0 ... 1 sec 1103 2nd BOOTP request: delay 0 ... 2 sec 1104 3rd BOOTP request: delay 0 ... 4 sec 1105 4th and following 1106 BOOTP requests: delay 0 ... 8 sec 1107 1108- DHCP Advanced Options: 1109 You can fine tune the DHCP functionality by defining 1110 CONFIG_BOOTP_* symbols: 1111 1112 CONFIG_BOOTP_SUBNETMASK 1113 CONFIG_BOOTP_GATEWAY 1114 CONFIG_BOOTP_HOSTNAME 1115 CONFIG_BOOTP_NISDOMAIN 1116 CONFIG_BOOTP_BOOTPATH 1117 CONFIG_BOOTP_BOOTFILESIZE 1118 CONFIG_BOOTP_DNS 1119 CONFIG_BOOTP_DNS2 1120 CONFIG_BOOTP_SEND_HOSTNAME 1121 CONFIG_BOOTP_NTPSERVER 1122 CONFIG_BOOTP_TIMEOFFSET 1123 CONFIG_BOOTP_VENDOREX 1124 1125 CONFIG_BOOTP_SERVERIP - TFTP server will be the serverip 1126 environment variable, not the BOOTP server. 1127 1128 CONFIG_BOOTP_DNS2 - If a DHCP client requests the DNS 1129 serverip from a DHCP server, it is possible that more 1130 than one DNS serverip is offered to the client. 1131 If CONFIG_BOOTP_DNS2 is enabled, the secondary DNS 1132 serverip will be stored in the additional environment 1133 variable "dnsip2". The first DNS serverip is always 1134 stored in the variable "dnsip", when CONFIG_BOOTP_DNS 1135 is defined. 1136 1137 CONFIG_BOOTP_SEND_HOSTNAME - Some DHCP servers are capable 1138 to do a dynamic update of a DNS server. To do this, they 1139 need the hostname of the DHCP requester. 1140 If CONFIG_BOOTP_SEND_HOSTNAME is defined, the content 1141 of the "hostname" environment variable is passed as 1142 option 12 to the DHCP server. 1143 1144 CONFIG_BOOTP_DHCP_REQUEST_DELAY 1145 1146 A 32bit value in microseconds for a delay between 1147 receiving a "DHCP Offer" and sending the "DHCP Request". 1148 This fixes a problem with certain DHCP servers that don't 1149 respond 100% of the time to a "DHCP request". E.g. On an 1150 AT91RM9200 processor running at 180MHz, this delay needed 1151 to be *at least* 15,000 usec before a Windows Server 2003 1152 DHCP server would reply 100% of the time. I recommend at 1153 least 50,000 usec to be safe. The alternative is to hope 1154 that one of the retries will be successful but note that 1155 the DHCP timeout and retry process takes a longer than 1156 this delay. 1157 1158 - CDP Options: 1159 CONFIG_CDP_DEVICE_ID 1160 1161 The device id used in CDP trigger frames. 1162 1163 CONFIG_CDP_DEVICE_ID_PREFIX 1164 1165 A two character string which is prefixed to the MAC address 1166 of the device. 1167 1168 CONFIG_CDP_PORT_ID 1169 1170 A printf format string which contains the ascii name of 1171 the port. Normally is set to "eth%d" which sets 1172 eth0 for the first ethernet, eth1 for the second etc. 1173 1174 CONFIG_CDP_CAPABILITIES 1175 1176 A 32bit integer which indicates the device capabilities; 1177 0x00000010 for a normal host which does not forwards. 1178 1179 CONFIG_CDP_VERSION 1180 1181 An ascii string containing the version of the software. 1182 1183 CONFIG_CDP_PLATFORM 1184 1185 An ascii string containing the name of the platform. 1186 1187 CONFIG_CDP_TRIGGER 1188 1189 A 32bit integer sent on the trigger. 1190 1191 CONFIG_CDP_POWER_CONSUMPTION 1192 1193 A 16bit integer containing the power consumption of the 1194 device in .1 of milliwatts. 1195 1196 CONFIG_CDP_APPLIANCE_VLAN_TYPE 1197 1198 A byte containing the id of the VLAN. 1199 1200- Status LED: CONFIG_STATUS_LED 1201 1202 Several configurations allow to display the current 1203 status using a LED. For instance, the LED will blink 1204 fast while running U-Boot code, stop blinking as 1205 soon as a reply to a BOOTP request was received, and 1206 start blinking slow once the Linux kernel is running 1207 (supported by a status LED driver in the Linux 1208 kernel). Defining CONFIG_STATUS_LED enables this 1209 feature in U-Boot. 1210 1211- CAN Support: CONFIG_CAN_DRIVER 1212 1213 Defining CONFIG_CAN_DRIVER enables CAN driver support 1214 on those systems that support this (optional) 1215 feature, like the TQM8xxL modules. 1216 1217- I2C Support: CONFIG_HARD_I2C | CONFIG_SOFT_I2C 1218 1219 These enable I2C serial bus commands. Defining either of 1220 (but not both of) CONFIG_HARD_I2C or CONFIG_SOFT_I2C will 1221 include the appropriate I2C driver for the selected cpu. 1222 1223 This will allow you to use i2c commands at the u-boot 1224 command line (as long as you set CONFIG_CMD_I2C in 1225 CONFIG_COMMANDS) and communicate with i2c based realtime 1226 clock chips. See common/cmd_i2c.c for a description of the 1227 command line interface. 1228 1229 CONFIG_I2C_CMD_TREE is a recommended option that places 1230 all I2C commands under a single 'i2c' root command. The 1231 older 'imm', 'imd', 'iprobe' etc. commands are considered 1232 deprecated and may disappear in the future. 1233 1234 CONFIG_HARD_I2C selects a hardware I2C controller. 1235 1236 CONFIG_SOFT_I2C configures u-boot to use a software (aka 1237 bit-banging) driver instead of CPM or similar hardware 1238 support for I2C. 1239 1240 There are several other quantities that must also be 1241 defined when you define CONFIG_HARD_I2C or CONFIG_SOFT_I2C. 1242 1243 In both cases you will need to define CFG_I2C_SPEED 1244 to be the frequency (in Hz) at which you wish your i2c bus 1245 to run and CFG_I2C_SLAVE to be the address of this node (ie 1246 the cpu's i2c node address). 1247 1248 Now, the u-boot i2c code for the mpc8xx (cpu/mpc8xx/i2c.c) 1249 sets the cpu up as a master node and so its address should 1250 therefore be cleared to 0 (See, eg, MPC823e User's Manual 1251 p.16-473). So, set CFG_I2C_SLAVE to 0. 1252 1253 That's all that's required for CONFIG_HARD_I2C. 1254 1255 If you use the software i2c interface (CONFIG_SOFT_I2C) 1256 then the following macros need to be defined (examples are 1257 from include/configs/lwmon.h): 1258 1259 I2C_INIT 1260 1261 (Optional). Any commands necessary to enable the I2C 1262 controller or configure ports. 1263 1264 eg: #define I2C_INIT (immr->im_cpm.cp_pbdir |= PB_SCL) 1265 1266 I2C_PORT 1267 1268 (Only for MPC8260 CPU). The I/O port to use (the code 1269 assumes both bits are on the same port). Valid values 1270 are 0..3 for ports A..D. 1271 1272 I2C_ACTIVE 1273 1274 The code necessary to make the I2C data line active 1275 (driven). If the data line is open collector, this 1276 define can be null. 1277 1278 eg: #define I2C_ACTIVE (immr->im_cpm.cp_pbdir |= PB_SDA) 1279 1280 I2C_TRISTATE 1281 1282 The code necessary to make the I2C data line tri-stated 1283 (inactive). If the data line is open collector, this 1284 define can be null. 1285 1286 eg: #define I2C_TRISTATE (immr->im_cpm.cp_pbdir &= ~PB_SDA) 1287 1288 I2C_READ 1289 1290 Code that returns TRUE if the I2C data line is high, 1291 FALSE if it is low. 1292 1293 eg: #define I2C_READ ((immr->im_cpm.cp_pbdat & PB_SDA) != 0) 1294 1295 I2C_SDA(bit) 1296 1297 If <bit> is TRUE, sets the I2C data line high. If it 1298 is FALSE, it clears it (low). 1299 1300 eg: #define I2C_SDA(bit) \ 1301 if(bit) immr->im_cpm.cp_pbdat |= PB_SDA; \ 1302 else immr->im_cpm.cp_pbdat &= ~PB_SDA 1303 1304 I2C_SCL(bit) 1305 1306 If <bit> is TRUE, sets the I2C clock line high. If it 1307 is FALSE, it clears it (low). 1308 1309 eg: #define I2C_SCL(bit) \ 1310 if(bit) immr->im_cpm.cp_pbdat |= PB_SCL; \ 1311 else immr->im_cpm.cp_pbdat &= ~PB_SCL 1312 1313 I2C_DELAY 1314 1315 This delay is invoked four times per clock cycle so this 1316 controls the rate of data transfer. The data rate thus 1317 is 1 / (I2C_DELAY * 4). Often defined to be something 1318 like: 1319 1320 #define I2C_DELAY udelay(2) 1321 1322 CFG_I2C_INIT_BOARD 1323 1324 When a board is reset during an i2c bus transfer 1325 chips might think that the current transfer is still 1326 in progress. On some boards it is possible to access 1327 the i2c SCLK line directly, either by using the 1328 processor pin as a GPIO or by having a second pin 1329 connected to the bus. If this option is defined a 1330 custom i2c_init_board() routine in boards/xxx/board.c 1331 is run early in the boot sequence. 1332 1333 CONFIG_I2CFAST (PPC405GP|PPC405EP only) 1334 1335 This option enables configuration of bi_iic_fast[] flags 1336 in u-boot bd_info structure based on u-boot environment 1337 variable "i2cfast". (see also i2cfast) 1338 1339 CONFIG_I2C_MULTI_BUS 1340 1341 This option allows the use of multiple I2C buses, each of which 1342 must have a controller. At any point in time, only one bus is 1343 active. To switch to a different bus, use the 'i2c dev' command. 1344 Note that bus numbering is zero-based. 1345 1346 CFG_I2C_NOPROBES 1347 1348 This option specifies a list of I2C devices that will be skipped 1349 when the 'i2c probe' command is issued (or 'iprobe' using the legacy 1350 command). If CONFIG_I2C_MULTI_BUS is set, specify a list of bus-device 1351 pairs. Otherwise, specify a 1D array of device addresses 1352 1353 e.g. 1354 #undef CONFIG_I2C_MULTI_BUS 1355 #define CFG_I2C_NOPROBES {0x50,0x68} 1356 1357 will skip addresses 0x50 and 0x68 on a board with one I2C bus 1358 1359 #define CONFIG_I2C_MULTI_BUS 1360 #define CFG_I2C_MULTI_NOPROBES {{0,0x50},{0,0x68},{1,0x54}} 1361 1362 will skip addresses 0x50 and 0x68 on bus 0 and address 0x54 on bus 1 1363 1364 CFG_SPD_BUS_NUM 1365 1366 If defined, then this indicates the I2C bus number for DDR SPD. 1367 If not defined, then U-Boot assumes that SPD is on I2C bus 0. 1368 1369 CFG_RTC_BUS_NUM 1370 1371 If defined, then this indicates the I2C bus number for the RTC. 1372 If not defined, then U-Boot assumes that RTC is on I2C bus 0. 1373 1374 CFG_DTT_BUS_NUM 1375 1376 If defined, then this indicates the I2C bus number for the DTT. 1377 If not defined, then U-Boot assumes that DTT is on I2C bus 0. 1378 1379 CONFIG_FSL_I2C 1380 1381 Define this option if you want to use Freescale's I2C driver in 1382 drivers/i2c/fsl_i2c.c. 1383 1384 1385- SPI Support: CONFIG_SPI 1386 1387 Enables SPI driver (so far only tested with 1388 SPI EEPROM, also an instance works with Crystal A/D and 1389 D/As on the SACSng board) 1390 1391 CONFIG_SPI_X 1392 1393 Enables extended (16-bit) SPI EEPROM addressing. 1394 (symmetrical to CONFIG_I2C_X) 1395 1396 CONFIG_SOFT_SPI 1397 1398 Enables a software (bit-bang) SPI driver rather than 1399 using hardware support. This is a general purpose 1400 driver that only requires three general I/O port pins 1401 (two outputs, one input) to function. If this is 1402 defined, the board configuration must define several 1403 SPI configuration items (port pins to use, etc). For 1404 an example, see include/configs/sacsng.h. 1405 1406 CONFIG_HARD_SPI 1407 1408 Enables a hardware SPI driver for general-purpose reads 1409 and writes. As with CONFIG_SOFT_SPI, the board configuration 1410 must define a list of chip-select function pointers. 1411 Currently supported on some MPC8xxx processors. For an 1412 example, see include/configs/mpc8349emds.h. 1413 1414- FPGA Support: CONFIG_FPGA 1415 1416 Enables FPGA subsystem. 1417 1418 CONFIG_FPGA_<vendor> 1419 1420 Enables support for specific chip vendors. 1421 (ALTERA, XILINX) 1422 1423 CONFIG_FPGA_<family> 1424 1425 Enables support for FPGA family. 1426 (SPARTAN2, SPARTAN3, VIRTEX2, CYCLONE2, ACEX1K, ACEX) 1427 1428 CONFIG_FPGA_COUNT 1429 1430 Specify the number of FPGA devices to support. 1431 1432 CFG_FPGA_PROG_FEEDBACK 1433 1434 Enable printing of hash marks during FPGA configuration. 1435 1436 CFG_FPGA_CHECK_BUSY 1437 1438 Enable checks on FPGA configuration interface busy 1439 status by the configuration function. This option 1440 will require a board or device specific function to 1441 be written. 1442 1443 CONFIG_FPGA_DELAY 1444 1445 If defined, a function that provides delays in the FPGA 1446 configuration driver. 1447 1448 CFG_FPGA_CHECK_CTRLC 1449 Allow Control-C to interrupt FPGA configuration 1450 1451 CFG_FPGA_CHECK_ERROR 1452 1453 Check for configuration errors during FPGA bitfile 1454 loading. For example, abort during Virtex II 1455 configuration if the INIT_B line goes low (which 1456 indicated a CRC error). 1457 1458 CFG_FPGA_WAIT_INIT 1459 1460 Maximum time to wait for the INIT_B line to deassert 1461 after PROB_B has been deasserted during a Virtex II 1462 FPGA configuration sequence. The default time is 500 1463 mS. 1464 1465 CFG_FPGA_WAIT_BUSY 1466 1467 Maximum time to wait for BUSY to deassert during 1468 Virtex II FPGA configuration. The default is 5 mS. 1469 1470 CFG_FPGA_WAIT_CONFIG 1471 1472 Time to wait after FPGA configuration. The default is 1473 200 mS. 1474 1475- Configuration Management: 1476 CONFIG_IDENT_STRING 1477 1478 If defined, this string will be added to the U-Boot 1479 version information (U_BOOT_VERSION) 1480 1481- Vendor Parameter Protection: 1482 1483 U-Boot considers the values of the environment 1484 variables "serial#" (Board Serial Number) and 1485 "ethaddr" (Ethernet Address) to be parameters that 1486 are set once by the board vendor / manufacturer, and 1487 protects these variables from casual modification by 1488 the user. Once set, these variables are read-only, 1489 and write or delete attempts are rejected. You can 1490 change this behviour: 1491 1492 If CONFIG_ENV_OVERWRITE is #defined in your config 1493 file, the write protection for vendor parameters is 1494 completely disabled. Anybody can change or delete 1495 these parameters. 1496 1497 Alternatively, if you #define _both_ CONFIG_ETHADDR 1498 _and_ CONFIG_OVERWRITE_ETHADDR_ONCE, a default 1499 ethernet address is installed in the environment, 1500 which can be changed exactly ONCE by the user. [The 1501 serial# is unaffected by this, i. e. it remains 1502 read-only.] 1503 1504- Protected RAM: 1505 CONFIG_PRAM 1506 1507 Define this variable to enable the reservation of 1508 "protected RAM", i. e. RAM which is not overwritten 1509 by U-Boot. Define CONFIG_PRAM to hold the number of 1510 kB you want to reserve for pRAM. You can overwrite 1511 this default value by defining an environment 1512 variable "pram" to the number of kB you want to 1513 reserve. Note that the board info structure will 1514 still show the full amount of RAM. If pRAM is 1515 reserved, a new environment variable "mem" will 1516 automatically be defined to hold the amount of 1517 remaining RAM in a form that can be passed as boot 1518 argument to Linux, for instance like that: 1519 1520 setenv bootargs ... mem=\${mem} 1521 saveenv 1522 1523 This way you can tell Linux not to use this memory, 1524 either, which results in a memory region that will 1525 not be affected by reboots. 1526 1527 *WARNING* If your board configuration uses automatic 1528 detection of the RAM size, you must make sure that 1529 this memory test is non-destructive. So far, the 1530 following board configurations are known to be 1531 "pRAM-clean": 1532 1533 ETX094, IVMS8, IVML24, SPD8xx, TQM8xxL, 1534 HERMES, IP860, RPXlite, LWMON, LANTEC, 1535 PCU_E, FLAGADM, TQM8260 1536 1537- Error Recovery: 1538 CONFIG_PANIC_HANG 1539 1540 Define this variable to stop the system in case of a 1541 fatal error, so that you have to reset it manually. 1542 This is probably NOT a good idea for an embedded 1543 system where you want to system to reboot 1544 automatically as fast as possible, but it may be 1545 useful during development since you can try to debug 1546 the conditions that lead to the situation. 1547 1548 CONFIG_NET_RETRY_COUNT 1549 1550 This variable defines the number of retries for 1551 network operations like ARP, RARP, TFTP, or BOOTP 1552 before giving up the operation. If not defined, a 1553 default value of 5 is used. 1554 1555- Command Interpreter: 1556 CONFIG_AUTO_COMPLETE 1557 1558 Enable auto completion of commands using TAB. 1559 1560 Note that this feature has NOT been implemented yet 1561 for the "hush" shell. 1562 1563 1564 CFG_HUSH_PARSER 1565 1566 Define this variable to enable the "hush" shell (from 1567 Busybox) as command line interpreter, thus enabling 1568 powerful command line syntax like 1569 if...then...else...fi conditionals or `&&' and '||' 1570 constructs ("shell scripts"). 1571 1572 If undefined, you get the old, much simpler behaviour 1573 with a somewhat smaller memory footprint. 1574 1575 1576 CFG_PROMPT_HUSH_PS2 1577 1578 This defines the secondary prompt string, which is 1579 printed when the command interpreter needs more input 1580 to complete a command. Usually "> ". 1581 1582 Note: 1583 1584 In the current implementation, the local variables 1585 space and global environment variables space are 1586 separated. Local variables are those you define by 1587 simply typing `name=value'. To access a local 1588 variable later on, you have write `$name' or 1589 `${name}'; to execute the contents of a variable 1590 directly type `$name' at the command prompt. 1591 1592 Global environment variables are those you use 1593 setenv/printenv to work with. To run a command stored 1594 in such a variable, you need to use the run command, 1595 and you must not use the '$' sign to access them. 1596 1597 To store commands and special characters in a 1598 variable, please use double quotation marks 1599 surrounding the whole text of the variable, instead 1600 of the backslashes before semicolons and special 1601 symbols. 1602 1603- Commandline Editing and History: 1604 CONFIG_CMDLINE_EDITING 1605 1606 Enable editiong and History functions for interactive 1607 commandline input operations 1608 1609- Default Environment: 1610 CONFIG_EXTRA_ENV_SETTINGS 1611 1612 Define this to contain any number of null terminated 1613 strings (variable = value pairs) that will be part of 1614 the default environment compiled into the boot image. 1615 1616 For example, place something like this in your 1617 board's config file: 1618 1619 #define CONFIG_EXTRA_ENV_SETTINGS \ 1620 "myvar1=value1\0" \ 1621 "myvar2=value2\0" 1622 1623 Warning: This method is based on knowledge about the 1624 internal format how the environment is stored by the 1625 U-Boot code. This is NOT an official, exported 1626 interface! Although it is unlikely that this format 1627 will change soon, there is no guarantee either. 1628 You better know what you are doing here. 1629 1630 Note: overly (ab)use of the default environment is 1631 discouraged. Make sure to check other ways to preset 1632 the environment like the autoscript function or the 1633 boot command first. 1634 1635- DataFlash Support: 1636 CONFIG_HAS_DATAFLASH 1637 1638 Defining this option enables DataFlash features and 1639 allows to read/write in Dataflash via the standard 1640 commands cp, md... 1641 1642- SystemACE Support: 1643 CONFIG_SYSTEMACE 1644 1645 Adding this option adds support for Xilinx SystemACE 1646 chips attached via some sort of local bus. The address 1647 of the chip must alsh be defined in the 1648 CFG_SYSTEMACE_BASE macro. For example: 1649 1650 #define CONFIG_SYSTEMACE 1651 #define CFG_SYSTEMACE_BASE 0xf0000000 1652 1653 When SystemACE support is added, the "ace" device type 1654 becomes available to the fat commands, i.e. fatls. 1655 1656- TFTP Fixed UDP Port: 1657 CONFIG_TFTP_PORT 1658 1659 If this is defined, the environment variable tftpsrcp 1660 is used to supply the TFTP UDP source port value. 1661 If tftpsrcp isn't defined, the normal pseudo-random port 1662 number generator is used. 1663 1664 Also, the environment variable tftpdstp is used to supply 1665 the TFTP UDP destination port value. If tftpdstp isn't 1666 defined, the normal port 69 is used. 1667 1668 The purpose for tftpsrcp is to allow a TFTP server to 1669 blindly start the TFTP transfer using the pre-configured 1670 target IP address and UDP port. This has the effect of 1671 "punching through" the (Windows XP) firewall, allowing 1672 the remainder of the TFTP transfer to proceed normally. 1673 A better solution is to properly configure the firewall, 1674 but sometimes that is not allowed. 1675 1676- Show boot progress: 1677 CONFIG_SHOW_BOOT_PROGRESS 1678 1679 Defining this option allows to add some board- 1680 specific code (calling a user-provided function 1681 "show_boot_progress(int)") that enables you to show 1682 the system's boot progress on some display (for 1683 example, some LED's) on your board. At the moment, 1684 the following checkpoints are implemented: 1685 1686Legacy uImage format: 1687 1688 Arg Where When 1689 1 common/cmd_bootm.c before attempting to boot an image 1690 -1 common/cmd_bootm.c Image header has bad magic number 1691 2 common/cmd_bootm.c Image header has correct magic number 1692 -2 common/cmd_bootm.c Image header has bad checksum 1693 3 common/cmd_bootm.c Image header has correct checksum 1694 -3 common/cmd_bootm.c Image data has bad checksum 1695 4 common/cmd_bootm.c Image data has correct checksum 1696 -4 common/cmd_bootm.c Image is for unsupported architecture 1697 5 common/cmd_bootm.c Architecture check OK 1698 -5 common/cmd_bootm.c Wrong Image Type (not kernel, multi) 1699 6 common/cmd_bootm.c Image Type check OK 1700 -6 common/cmd_bootm.c gunzip uncompression error 1701 -7 common/cmd_bootm.c Unimplemented compression type 1702 7 common/cmd_bootm.c Uncompression OK 1703 8 common/cmd_bootm.c No uncompress/copy overwrite error 1704 -9 common/cmd_bootm.c Unsupported OS (not Linux, BSD, VxWorks, QNX) 1705 1706 9 common/image.c Start initial ramdisk verification 1707 -10 common/image.c Ramdisk header has bad magic number 1708 -11 common/image.c Ramdisk header has bad checksum 1709 10 common/image.c Ramdisk header is OK 1710 -12 common/image.c Ramdisk data has bad checksum 1711 11 common/image.c Ramdisk data has correct checksum 1712 12 common/image.c Ramdisk verification complete, start loading 1713 -13 common/image.c Wrong Image Type (not PPC Linux Ramdisk) 1714 13 common/image.c Start multifile image verification 1715 14 common/image.c No initial ramdisk, no multifile, continue. 1716 1717 15 lib_<arch>/bootm.c All preparation done, transferring control to OS 1718 1719 -30 lib_ppc/board.c Fatal error, hang the system 1720 -31 post/post.c POST test failed, detected by post_output_backlog() 1721 -32 post/post.c POST test failed, detected by post_run_single() 1722 1723 34 common/cmd_doc.c before loading a Image from a DOC device 1724 -35 common/cmd_doc.c Bad usage of "doc" command 1725 35 common/cmd_doc.c correct usage of "doc" command 1726 -36 common/cmd_doc.c No boot device 1727 36 common/cmd_doc.c correct boot device 1728 -37 common/cmd_doc.c Unknown Chip ID on boot device 1729 37 common/cmd_doc.c correct chip ID found, device available 1730 -38 common/cmd_doc.c Read Error on boot device 1731 38 common/cmd_doc.c reading Image header from DOC device OK 1732 -39 common/cmd_doc.c Image header has bad magic number 1733 39 common/cmd_doc.c Image header has correct magic number 1734 -40 common/cmd_doc.c Error reading Image from DOC device 1735 40 common/cmd_doc.c Image header has correct magic number 1736 41 common/cmd_ide.c before loading a Image from a IDE device 1737 -42 common/cmd_ide.c Bad usage of "ide" command 1738 42 common/cmd_ide.c correct usage of "ide" command 1739 -43 common/cmd_ide.c No boot device 1740 43 common/cmd_ide.c boot device found 1741 -44 common/cmd_ide.c Device not available 1742 44 common/cmd_ide.c Device available 1743 -45 common/cmd_ide.c wrong partition selected 1744 45 common/cmd_ide.c partition selected 1745 -46 common/cmd_ide.c Unknown partition table 1746 46 common/cmd_ide.c valid partition table found 1747 -47 common/cmd_ide.c Invalid partition type 1748 47 common/cmd_ide.c correct partition type 1749 -48 common/cmd_ide.c Error reading Image Header on boot device 1750 48 common/cmd_ide.c reading Image Header from IDE device OK 1751 -49 common/cmd_ide.c Image header has bad magic number 1752 49 common/cmd_ide.c Image header has correct magic number 1753 -50 common/cmd_ide.c Image header has bad checksum 1754 50 common/cmd_ide.c Image header has correct checksum 1755 -51 common/cmd_ide.c Error reading Image from IDE device 1756 51 common/cmd_ide.c reading Image from IDE device OK 1757 52 common/cmd_nand.c before loading a Image from a NAND device 1758 -53 common/cmd_nand.c Bad usage of "nand" command 1759 53 common/cmd_nand.c correct usage of "nand" command 1760 -54 common/cmd_nand.c No boot device 1761 54 common/cmd_nand.c boot device found 1762 -55 common/cmd_nand.c Unknown Chip ID on boot device 1763 55 common/cmd_nand.c correct chip ID found, device available 1764 -56 common/cmd_nand.c Error reading Image Header on boot device 1765 56 common/cmd_nand.c reading Image Header from NAND device OK 1766 -57 common/cmd_nand.c Image header has bad magic number 1767 57 common/cmd_nand.c Image header has correct magic number 1768 -58 common/cmd_nand.c Error reading Image from NAND device 1769 58 common/cmd_nand.c reading Image from NAND device OK 1770 1771 -60 common/env_common.c Environment has a bad CRC, using default 1772 1773 64 net/eth.c starting with Ethernetconfiguration. 1774 -64 net/eth.c no Ethernet found. 1775 65 net/eth.c Ethernet found. 1776 1777 -80 common/cmd_net.c usage wrong 1778 80 common/cmd_net.c before calling NetLoop() 1779 -81 common/cmd_net.c some error in NetLoop() occured 1780 81 common/cmd_net.c NetLoop() back without error 1781 -82 common/cmd_net.c size == 0 (File with size 0 loaded) 1782 82 common/cmd_net.c trying automatic boot 1783 83 common/cmd_net.c running autoscript 1784 -83 common/cmd_net.c some error in automatic boot or autoscript 1785 84 common/cmd_net.c end without errors 1786 1787FIT uImage format: 1788 1789 Arg Where When 1790 100 common/cmd_bootm.c Kernel FIT Image has correct format 1791 -100 common/cmd_bootm.c Kernel FIT Image has incorrect format 1792 101 common/cmd_bootm.c No Kernel subimage unit name, using configuration 1793 -101 common/cmd_bootm.c Can't get configuration for kernel subimage 1794 102 common/cmd_bootm.c Kernel unit name specified 1795 -103 common/cmd_bootm.c Can't get kernel subimage node offset 1796 103 common/cmd_bootm.c Found configuration node 1797 104 common/cmd_bootm.c Got kernel subimage node offset 1798 -104 common/cmd_bootm.c Kernel subimage hash verification failed 1799 105 common/cmd_bootm.c Kernel subimage hash verification OK 1800 -105 common/cmd_bootm.c Kernel subimage is for unsupported architecture 1801 106 common/cmd_bootm.c Architecture check OK 1802 -106 common/cmd_bootm.c Kernel subimage has wrong typea 1803 107 common/cmd_bootm.c Kernel subimge type OK 1804 -107 common/cmd_bootm.c Can't get kernel subimage data/size 1805 108 common/cmd_bootm.c Got kernel subimage data/size 1806 -108 common/cmd_bootm.c Wrong image type (not legacy, FIT) 1807 -109 common/cmd_bootm.c Can't get kernel subimage type 1808 -110 common/cmd_bootm.c Can't get kernel subimage comp 1809 -111 common/cmd_bootm.c Can't get kernel subimage os 1810 -112 common/cmd_bootm.c Can't get kernel subimage load address 1811 -113 common/cmd_bootm.c Image uncompress/copy overwrite error 1812 1813 120 common/image.c Start initial ramdisk verification 1814 -120 common/image.c Ramdisk FIT image has incorrect format 1815 121 common/image.c Ramdisk FIT image has correct format 1816 122 common/image.c No Ramdisk subimage unit name, using configuration 1817 -122 common/image.c Can't get configuration for ramdisk subimage 1818 123 common/image.c Ramdisk unit name specified 1819 -124 common/image.c Can't get ramdisk subimage node offset 1820 125 common/image.c Got ramdisk subimage node offset 1821 -125 common/image.c Ramdisk subimage hash verification failed 1822 126 common/image.c Ramdisk subimage hash verification OK 1823 -126 common/image.c Ramdisk subimage for unsupported architecture 1824 127 common/image.c Architecture check OK 1825 -127 common/image.c Can't get ramdisk subimage data/size 1826 128 common/image.c Got ramdisk subimage data/size 1827 129 common/image.c Can't get ramdisk load address 1828 -129 common/image.c Got ramdisk load address 1829 1830 -130 common/cmd_doc.c Icorrect FIT image format 1831 131 common/cmd_doc.c FIT image format OK 1832 1833 -140 common/cmd_ide.c Icorrect FIT image format 1834 141 common/cmd_ide.c FIT image format OK 1835 1836 -150 common/cmd_nand.c Icorrect FIT image format 1837 151 common/cmd_nand.c FIT image format OK 1838 1839 1840Modem Support: 1841-------------- 1842 1843[so far only for SMDK2400 and TRAB boards] 1844 1845- Modem support endable: 1846 CONFIG_MODEM_SUPPORT 1847 1848- RTS/CTS Flow control enable: 1849 CONFIG_HWFLOW 1850 1851- Modem debug support: 1852 CONFIG_MODEM_SUPPORT_DEBUG 1853 1854 Enables debugging stuff (char screen[1024], dbg()) 1855 for modem support. Useful only with BDI2000. 1856 1857- Interrupt support (PPC): 1858 1859 There are common interrupt_init() and timer_interrupt() 1860 for all PPC archs. interrupt_init() calls interrupt_init_cpu() 1861 for cpu specific initialization. interrupt_init_cpu() 1862 should set decrementer_count to appropriate value. If 1863 cpu resets decrementer automatically after interrupt 1864 (ppc4xx) it should set decrementer_count to zero. 1865 timer_interrupt() calls timer_interrupt_cpu() for cpu 1866 specific handling. If board has watchdog / status_led 1867 / other_activity_monitor it works automatically from 1868 general timer_interrupt(). 1869 1870- General: 1871 1872 In the target system modem support is enabled when a 1873 specific key (key combination) is pressed during 1874 power-on. Otherwise U-Boot will boot normally 1875 (autoboot). The key_pressed() fuction is called from 1876 board_init(). Currently key_pressed() is a dummy 1877 function, returning 1 and thus enabling modem 1878 initialization. 1879 1880 If there are no modem init strings in the 1881 environment, U-Boot proceed to autoboot; the 1882 previous output (banner, info printfs) will be 1883 supressed, though. 1884 1885 See also: doc/README.Modem 1886 1887 1888Configuration Settings: 1889----------------------- 1890 1891- CFG_LONGHELP: Defined when you want long help messages included; 1892 undefine this when you're short of memory. 1893 1894- CFG_PROMPT: This is what U-Boot prints on the console to 1895 prompt for user input. 1896 1897- CFG_CBSIZE: Buffer size for input from the Console 1898 1899- CFG_PBSIZE: Buffer size for Console output 1900 1901- CFG_MAXARGS: max. Number of arguments accepted for monitor commands 1902 1903- CFG_BARGSIZE: Buffer size for Boot Arguments which are passed to 1904 the application (usually a Linux kernel) when it is 1905 booted 1906 1907- CFG_BAUDRATE_TABLE: 1908 List of legal baudrate settings for this board. 1909 1910- CFG_CONSOLE_INFO_QUIET 1911 Suppress display of console information at boot. 1912 1913- CFG_CONSOLE_IS_IN_ENV 1914 If the board specific function 1915 extern int overwrite_console (void); 1916 returns 1, the stdin, stderr and stdout are switched to the 1917 serial port, else the settings in the environment are used. 1918 1919- CFG_CONSOLE_OVERWRITE_ROUTINE 1920 Enable the call to overwrite_console(). 1921 1922- CFG_CONSOLE_ENV_OVERWRITE 1923 Enable overwrite of previous console environment settings. 1924 1925- CFG_MEMTEST_START, CFG_MEMTEST_END: 1926 Begin and End addresses of the area used by the 1927 simple memory test. 1928 1929- CFG_ALT_MEMTEST: 1930 Enable an alternate, more extensive memory test. 1931 1932- CFG_MEMTEST_SCRATCH: 1933 Scratch address used by the alternate memory test 1934 You only need to set this if address zero isn't writeable 1935 1936- CFG_MEM_TOP_HIDE (PPC only): 1937 If CFG_MEM_TOP_HIDE is defined in the board config header, 1938 this specified memory area will get subtracted from the top 1939 (end) of ram and won't get "touched" at all by U-Boot. By 1940 fixing up gd->ram_size the Linux kernel should gets passed 1941 the now "corrected" memory size and won't touch it either. 1942 This should work for arch/ppc and arch/powerpc. Only Linux 1943 board ports in arch/powerpc with bootwrapper support that 1944 recalculate the memory size from the SDRAM controller setup 1945 will have to get fixed in Linux additionally. 1946 1947 This option can be used as a workaround for the 440EPx/GRx 1948 CHIP 11 errata where the last 256 bytes in SDRAM shouldn't 1949 be touched. 1950 1951 WARNING: Please make sure that this value is a multiple of 1952 the Linux page size (normally 4k). If this is not the case, 1953 then the end address of the Linux memory will be located at a 1954 non page size aligned address and this could cause major 1955 problems. 1956 1957- CFG_TFTP_LOADADDR: 1958 Default load address for network file downloads 1959 1960- CFG_LOADS_BAUD_CHANGE: 1961 Enable temporary baudrate change while serial download 1962 1963- CFG_SDRAM_BASE: 1964 Physical start address of SDRAM. _Must_ be 0 here. 1965 1966- CFG_MBIO_BASE: 1967 Physical start address of Motherboard I/O (if using a 1968 Cogent motherboard) 1969 1970- CFG_FLASH_BASE: 1971 Physical start address of Flash memory. 1972 1973- CFG_MONITOR_BASE: 1974 Physical start address of boot monitor code (set by 1975 make config files to be same as the text base address 1976 (TEXT_BASE) used when linking) - same as 1977 CFG_FLASH_BASE when booting from flash. 1978 1979- CFG_MONITOR_LEN: 1980 Size of memory reserved for monitor code, used to 1981 determine _at_compile_time_ (!) if the environment is 1982 embedded within the U-Boot image, or in a separate 1983 flash sector. 1984 1985- CFG_MALLOC_LEN: 1986 Size of DRAM reserved for malloc() use. 1987 1988- CFG_BOOTM_LEN: 1989 Normally compressed uImages are limited to an 1990 uncompressed size of 8 MBytes. If this is not enough, 1991 you can define CFG_BOOTM_LEN in your board config file 1992 to adjust this setting to your needs. 1993 1994- CFG_BOOTMAPSZ: 1995 Maximum size of memory mapped by the startup code of 1996 the Linux kernel; all data that must be processed by 1997 the Linux kernel (bd_info, boot arguments, eventually 1998 initrd image) must be put below this limit. 1999 2000- CFG_MAX_FLASH_BANKS: 2001 Max number of Flash memory banks 2002 2003- CFG_MAX_FLASH_SECT: 2004 Max number of sectors on a Flash chip 2005 2006- CFG_FLASH_ERASE_TOUT: 2007 Timeout for Flash erase operations (in ms) 2008 2009- CFG_FLASH_WRITE_TOUT: 2010 Timeout for Flash write operations (in ms) 2011 2012- CFG_FLASH_LOCK_TOUT 2013 Timeout for Flash set sector lock bit operation (in ms) 2014 2015- CFG_FLASH_UNLOCK_TOUT 2016 Timeout for Flash clear lock bits operation (in ms) 2017 2018- CFG_FLASH_PROTECTION 2019 If defined, hardware flash sectors protection is used 2020 instead of U-Boot software protection. 2021 2022- CFG_DIRECT_FLASH_TFTP: 2023 2024 Enable TFTP transfers directly to flash memory; 2025 without this option such a download has to be 2026 performed in two steps: (1) download to RAM, and (2) 2027 copy from RAM to flash. 2028 2029 The two-step approach is usually more reliable, since 2030 you can check if the download worked before you erase 2031 the flash, but in some situations (when sytem RAM is 2032 too limited to allow for a tempory copy of the 2033 downloaded image) this option may be very useful. 2034 2035- CFG_FLASH_CFI: 2036 Define if the flash driver uses extra elements in the 2037 common flash structure for storing flash geometry. 2038 2039- CFG_FLASH_CFI_DRIVER 2040 This option also enables the building of the cfi_flash driver 2041 in the drivers directory 2042 2043- CFG_FLASH_USE_BUFFER_WRITE 2044 Use buffered writes to flash. 2045 2046- CONFIG_FLASH_SPANSION_S29WS_N 2047 s29ws-n MirrorBit flash has non-standard addresses for buffered 2048 write commands. 2049 2050- CFG_FLASH_QUIET_TEST 2051 If this option is defined, the common CFI flash doesn't 2052 print it's warning upon not recognized FLASH banks. This 2053 is useful, if some of the configured banks are only 2054 optionally available. 2055 2056- CONFIG_FLASH_SHOW_PROGRESS 2057 If defined (must be an integer), print out countdown 2058 digits and dots. Recommended value: 45 (9..1) for 80 2059 column displays, 15 (3..1) for 40 column displays. 2060 2061- CFG_RX_ETH_BUFFER: 2062 Defines the number of ethernet receive buffers. On some 2063 ethernet controllers it is recommended to set this value 2064 to 8 or even higher (EEPRO100 or 405 EMAC), since all 2065 buffers can be full shortly after enabling the interface 2066 on high ethernet traffic. 2067 Defaults to 4 if not defined. 2068 2069The following definitions that deal with the placement and management 2070of environment data (variable area); in general, we support the 2071following configurations: 2072 2073- CFG_ENV_IS_IN_FLASH: 2074 2075 Define this if the environment is in flash memory. 2076 2077 a) The environment occupies one whole flash sector, which is 2078 "embedded" in the text segment with the U-Boot code. This 2079 happens usually with "bottom boot sector" or "top boot 2080 sector" type flash chips, which have several smaller 2081 sectors at the start or the end. For instance, such a 2082 layout can have sector sizes of 8, 2x4, 16, Nx32 kB. In 2083 such a case you would place the environment in one of the 2084 4 kB sectors - with U-Boot code before and after it. With 2085 "top boot sector" type flash chips, you would put the 2086 environment in one of the last sectors, leaving a gap 2087 between U-Boot and the environment. 2088 2089 - CFG_ENV_OFFSET: 2090 2091 Offset of environment data (variable area) to the 2092 beginning of flash memory; for instance, with bottom boot 2093 type flash chips the second sector can be used: the offset 2094 for this sector is given here. 2095 2096 CFG_ENV_OFFSET is used relative to CFG_FLASH_BASE. 2097 2098 - CFG_ENV_ADDR: 2099 2100 This is just another way to specify the start address of 2101 the flash sector containing the environment (instead of 2102 CFG_ENV_OFFSET). 2103 2104 - CFG_ENV_SECT_SIZE: 2105 2106 Size of the sector containing the environment. 2107 2108 2109 b) Sometimes flash chips have few, equal sized, BIG sectors. 2110 In such a case you don't want to spend a whole sector for 2111 the environment. 2112 2113 - CFG_ENV_SIZE: 2114 2115 If you use this in combination with CFG_ENV_IS_IN_FLASH 2116 and CFG_ENV_SECT_SIZE, you can specify to use only a part 2117 of this flash sector for the environment. This saves 2118 memory for the RAM copy of the environment. 2119 2120 It may also save flash memory if you decide to use this 2121 when your environment is "embedded" within U-Boot code, 2122 since then the remainder of the flash sector could be used 2123 for U-Boot code. It should be pointed out that this is 2124 STRONGLY DISCOURAGED from a robustness point of view: 2125 updating the environment in flash makes it always 2126 necessary to erase the WHOLE sector. If something goes 2127 wrong before the contents has been restored from a copy in 2128 RAM, your target system will be dead. 2129 2130 - CFG_ENV_ADDR_REDUND 2131 CFG_ENV_SIZE_REDUND 2132 2133 These settings describe a second storage area used to hold 2134 a redundand copy of the environment data, so that there is 2135 a valid backup copy in case there is a power failure during 2136 a "saveenv" operation. 2137 2138BE CAREFUL! Any changes to the flash layout, and some changes to the 2139source code will make it necessary to adapt <board>/u-boot.lds* 2140accordingly! 2141 2142 2143- CFG_ENV_IS_IN_NVRAM: 2144 2145 Define this if you have some non-volatile memory device 2146 (NVRAM, battery buffered SRAM) which you want to use for the 2147 environment. 2148 2149 - CFG_ENV_ADDR: 2150 - CFG_ENV_SIZE: 2151 2152 These two #defines are used to determin the memory area you 2153 want to use for environment. It is assumed that this memory 2154 can just be read and written to, without any special 2155 provision. 2156 2157BE CAREFUL! The first access to the environment happens quite early 2158in U-Boot initalization (when we try to get the setting of for the 2159console baudrate). You *MUST* have mappend your NVRAM area then, or 2160U-Boot will hang. 2161 2162Please note that even with NVRAM we still use a copy of the 2163environment in RAM: we could work on NVRAM directly, but we want to 2164keep settings there always unmodified except somebody uses "saveenv" 2165to save the current settings. 2166 2167 2168- CFG_ENV_IS_IN_EEPROM: 2169 2170 Use this if you have an EEPROM or similar serial access 2171 device and a driver for it. 2172 2173 - CFG_ENV_OFFSET: 2174 - CFG_ENV_SIZE: 2175 2176 These two #defines specify the offset and size of the 2177 environment area within the total memory of your EEPROM. 2178 2179 - CFG_I2C_EEPROM_ADDR: 2180 If defined, specified the chip address of the EEPROM device. 2181 The default address is zero. 2182 2183 - CFG_EEPROM_PAGE_WRITE_BITS: 2184 If defined, the number of bits used to address bytes in a 2185 single page in the EEPROM device. A 64 byte page, for example 2186 would require six bits. 2187 2188 - CFG_EEPROM_PAGE_WRITE_DELAY_MS: 2189 If defined, the number of milliseconds to delay between 2190 page writes. The default is zero milliseconds. 2191 2192 - CFG_I2C_EEPROM_ADDR_LEN: 2193 The length in bytes of the EEPROM memory array address. Note 2194 that this is NOT the chip address length! 2195 2196 - CFG_I2C_EEPROM_ADDR_OVERFLOW: 2197 EEPROM chips that implement "address overflow" are ones 2198 like Catalyst 24WC04/08/16 which has 9/10/11 bits of 2199 address and the extra bits end up in the "chip address" bit 2200 slots. This makes a 24WC08 (1Kbyte) chip look like four 256 2201 byte chips. 2202 2203 Note that we consider the length of the address field to 2204 still be one byte because the extra address bits are hidden 2205 in the chip address. 2206 2207 - CFG_EEPROM_SIZE: 2208 The size in bytes of the EEPROM device. 2209 2210 2211- CFG_ENV_IS_IN_DATAFLASH: 2212 2213 Define this if you have a DataFlash memory device which you 2214 want to use for the environment. 2215 2216 - CFG_ENV_OFFSET: 2217 - CFG_ENV_ADDR: 2218 - CFG_ENV_SIZE: 2219 2220 These three #defines specify the offset and size of the 2221 environment area within the total memory of your DataFlash placed 2222 at the specified address. 2223 2224- CFG_ENV_IS_IN_NAND: 2225 2226 Define this if you have a NAND device which you want to use 2227 for the environment. 2228 2229 - CFG_ENV_OFFSET: 2230 - CFG_ENV_SIZE: 2231 2232 These two #defines specify the offset and size of the environment 2233 area within the first NAND device. 2234 2235 - CFG_ENV_OFFSET_REDUND 2236 2237 This setting describes a second storage area of CFG_ENV_SIZE 2238 size used to hold a redundant copy of the environment data, 2239 so that there is a valid backup copy in case there is a 2240 power failure during a "saveenv" operation. 2241 2242 Note: CFG_ENV_OFFSET and CFG_ENV_OFFSET_REDUND must be aligned 2243 to a block boundary, and CFG_ENV_SIZE must be a multiple of 2244 the NAND devices block size. 2245 2246- CFG_SPI_INIT_OFFSET 2247 2248 Defines offset to the initial SPI buffer area in DPRAM. The 2249 area is used at an early stage (ROM part) if the environment 2250 is configured to reside in the SPI EEPROM: We need a 520 byte 2251 scratch DPRAM area. It is used between the two initialization 2252 calls (spi_init_f() and spi_init_r()). A value of 0xB00 seems 2253 to be a good choice since it makes it far enough from the 2254 start of the data area as well as from the stack pointer. 2255 2256Please note that the environment is read-only until the monitor 2257has been relocated to RAM and a RAM copy of the environment has been 2258created; also, when using EEPROM you will have to use getenv_r() 2259until then to read environment variables. 2260 2261The environment is protected by a CRC32 checksum. Before the monitor 2262is relocated into RAM, as a result of a bad CRC you will be working 2263with the compiled-in default environment - *silently*!!! [This is 2264necessary, because the first environment variable we need is the 2265"baudrate" setting for the console - if we have a bad CRC, we don't 2266have any device yet where we could complain.] 2267 2268Note: once the monitor has been relocated, then it will complain if 2269the default environment is used; a new CRC is computed as soon as you 2270use the "saveenv" command to store a valid environment. 2271 2272- CFG_FAULT_ECHO_LINK_DOWN: 2273 Echo the inverted Ethernet link state to the fault LED. 2274 2275 Note: If this option is active, then CFG_FAULT_MII_ADDR 2276 also needs to be defined. 2277 2278- CFG_FAULT_MII_ADDR: 2279 MII address of the PHY to check for the Ethernet link state. 2280 2281- CFG_64BIT_VSPRINTF: 2282 Makes vsprintf (and all *printf functions) support printing 2283 of 64bit values by using the L quantifier 2284 2285- CFG_64BIT_STRTOUL: 2286 Adds simple_strtoull that returns a 64bit value 2287 2288Low Level (hardware related) configuration options: 2289--------------------------------------------------- 2290 2291- CFG_CACHELINE_SIZE: 2292 Cache Line Size of the CPU. 2293 2294- CFG_DEFAULT_IMMR: 2295 Default address of the IMMR after system reset. 2296 2297 Needed on some 8260 systems (MPC8260ADS, PQ2FADS-ZU, 2298 and RPXsuper) to be able to adjust the position of 2299 the IMMR register after a reset. 2300 2301- Floppy Disk Support: 2302 CFG_FDC_DRIVE_NUMBER 2303 2304 the default drive number (default value 0) 2305 2306 CFG_ISA_IO_STRIDE 2307 2308 defines the spacing between fdc chipset registers 2309 (default value 1) 2310 2311 CFG_ISA_IO_OFFSET 2312 2313 defines the offset of register from address. It 2314 depends on which part of the data bus is connected to 2315 the fdc chipset. (default value 0) 2316 2317 If CFG_ISA_IO_STRIDE CFG_ISA_IO_OFFSET and 2318 CFG_FDC_DRIVE_NUMBER are undefined, they take their 2319 default value. 2320 2321 if CFG_FDC_HW_INIT is defined, then the function 2322 fdc_hw_init() is called at the beginning of the FDC 2323 setup. fdc_hw_init() must be provided by the board 2324 source code. It is used to make hardware dependant 2325 initializations. 2326 2327- CFG_IMMR: Physical address of the Internal Memory. 2328 DO NOT CHANGE unless you know exactly what you're 2329 doing! (11-4) [MPC8xx/82xx systems only] 2330 2331- CFG_INIT_RAM_ADDR: 2332 2333 Start address of memory area that can be used for 2334 initial data and stack; please note that this must be 2335 writable memory that is working WITHOUT special 2336 initialization, i. e. you CANNOT use normal RAM which 2337 will become available only after programming the 2338 memory controller and running certain initialization 2339 sequences. 2340 2341 U-Boot uses the following memory types: 2342 - MPC8xx and MPC8260: IMMR (internal memory of the CPU) 2343 - MPC824X: data cache 2344 - PPC4xx: data cache 2345 2346- CFG_GBL_DATA_OFFSET: 2347 2348 Offset of the initial data structure in the memory 2349 area defined by CFG_INIT_RAM_ADDR. Usually 2350 CFG_GBL_DATA_OFFSET is chosen such that the initial 2351 data is located at the end of the available space 2352 (sometimes written as (CFG_INIT_RAM_END - 2353 CFG_INIT_DATA_SIZE), and the initial stack is just 2354 below that area (growing from (CFG_INIT_RAM_ADDR + 2355 CFG_GBL_DATA_OFFSET) downward. 2356 2357 Note: 2358 On the MPC824X (or other systems that use the data 2359 cache for initial memory) the address chosen for 2360 CFG_INIT_RAM_ADDR is basically arbitrary - it must 2361 point to an otherwise UNUSED address space between 2362 the top of RAM and the start of the PCI space. 2363 2364- CFG_SIUMCR: SIU Module Configuration (11-6) 2365 2366- CFG_SYPCR: System Protection Control (11-9) 2367 2368- CFG_TBSCR: Time Base Status and Control (11-26) 2369 2370- CFG_PISCR: Periodic Interrupt Status and Control (11-31) 2371 2372- CFG_PLPRCR: PLL, Low-Power, and Reset Control Register (15-30) 2373 2374- CFG_SCCR: System Clock and reset Control Register (15-27) 2375 2376- CFG_OR_TIMING_SDRAM: 2377 SDRAM timing 2378 2379- CFG_MAMR_PTA: 2380 periodic timer for refresh 2381 2382- CFG_DER: Debug Event Register (37-47) 2383 2384- FLASH_BASE0_PRELIM, FLASH_BASE1_PRELIM, CFG_REMAP_OR_AM, 2385 CFG_PRELIM_OR_AM, CFG_OR_TIMING_FLASH, CFG_OR0_REMAP, 2386 CFG_OR0_PRELIM, CFG_BR0_PRELIM, CFG_OR1_REMAP, CFG_OR1_PRELIM, 2387 CFG_BR1_PRELIM: 2388 Memory Controller Definitions: BR0/1 and OR0/1 (FLASH) 2389 2390- SDRAM_BASE2_PRELIM, SDRAM_BASE3_PRELIM, SDRAM_MAX_SIZE, 2391 CFG_OR_TIMING_SDRAM, CFG_OR2_PRELIM, CFG_BR2_PRELIM, 2392 CFG_OR3_PRELIM, CFG_BR3_PRELIM: 2393 Memory Controller Definitions: BR2/3 and OR2/3 (SDRAM) 2394 2395- CFG_MAMR_PTA, CFG_MPTPR_2BK_4K, CFG_MPTPR_1BK_4K, CFG_MPTPR_2BK_8K, 2396 CFG_MPTPR_1BK_8K, CFG_MAMR_8COL, CFG_MAMR_9COL: 2397 Machine Mode Register and Memory Periodic Timer 2398 Prescaler definitions (SDRAM timing) 2399 2400- CFG_I2C_UCODE_PATCH, CFG_I2C_DPMEM_OFFSET [0x1FC0]: 2401 enable I2C microcode relocation patch (MPC8xx); 2402 define relocation offset in DPRAM [DSP2] 2403 2404- CFG_SMC_UCODE_PATCH, CFG_SMC_DPMEM_OFFSET [0x1FC0]: 2405 enable SMC microcode relocation patch (MPC8xx); 2406 define relocation offset in DPRAM [SMC1] 2407 2408- CFG_SPI_UCODE_PATCH, CFG_SPI_DPMEM_OFFSET [0x1FC0]: 2409 enable SPI microcode relocation patch (MPC8xx); 2410 define relocation offset in DPRAM [SCC4] 2411 2412- CFG_USE_OSCCLK: 2413 Use OSCM clock mode on MBX8xx board. Be careful, 2414 wrong setting might damage your board. Read 2415 doc/README.MBX before setting this variable! 2416 2417- CFG_CPM_POST_WORD_ADDR: (MPC8xx, MPC8260 only) 2418 Offset of the bootmode word in DPRAM used by post 2419 (Power On Self Tests). This definition overrides 2420 #define'd default value in commproc.h resp. 2421 cpm_8260.h. 2422 2423- CFG_PCI_SLV_MEM_LOCAL, CFG_PCI_SLV_MEM_BUS, CFG_PICMR0_MASK_ATTRIB, 2424 CFG_PCI_MSTR0_LOCAL, CFG_PCIMSK0_MASK, CFG_PCI_MSTR1_LOCAL, 2425 CFG_PCIMSK1_MASK, CFG_PCI_MSTR_MEM_LOCAL, CFG_PCI_MSTR_MEM_BUS, 2426 CFG_CPU_PCI_MEM_START, CFG_PCI_MSTR_MEM_SIZE, CFG_POCMR0_MASK_ATTRIB, 2427 CFG_PCI_MSTR_MEMIO_LOCAL, CFG_PCI_MSTR_MEMIO_BUS, CPU_PCI_MEMIO_START, 2428 CFG_PCI_MSTR_MEMIO_SIZE, CFG_POCMR1_MASK_ATTRIB, CFG_PCI_MSTR_IO_LOCAL, 2429 CFG_PCI_MSTR_IO_BUS, CFG_CPU_PCI_IO_START, CFG_PCI_MSTR_IO_SIZE, 2430 CFG_POCMR2_MASK_ATTRIB: (MPC826x only) 2431 Overrides the default PCI memory map in cpu/mpc8260/pci.c if set. 2432 2433- CONFIG_SPD_EEPROM 2434 Get DDR timing information from an I2C EEPROM. Common 2435 with pluggable memory modules such as SODIMMs 2436 2437 SPD_EEPROM_ADDRESS 2438 I2C address of the SPD EEPROM 2439 2440- CFG_SPD_BUS_NUM 2441 If SPD EEPROM is on an I2C bus other than the first 2442 one, specify here. Note that the value must resolve 2443 to something your driver can deal with. 2444 2445- CFG_83XX_DDR_USES_CS0 2446 Only for 83xx systems. If specified, then DDR should 2447 be configured using CS0 and CS1 instead of CS2 and CS3. 2448 2449- CFG_83XX_DDR_USES_CS0 2450 Only for 83xx systems. If specified, then DDR should 2451 be configured using CS0 and CS1 instead of CS2 and CS3. 2452 2453- CONFIG_ETHER_ON_FEC[12] 2454 Define to enable FEC[12] on a 8xx series processor. 2455 2456- CONFIG_FEC[12]_PHY 2457 Define to the hardcoded PHY address which corresponds 2458 to the given FEC; i. e. 2459 #define CONFIG_FEC1_PHY 4 2460 means that the PHY with address 4 is connected to FEC1 2461 2462 When set to -1, means to probe for first available. 2463 2464- CONFIG_FEC[12]_PHY_NORXERR 2465 The PHY does not have a RXERR line (RMII only). 2466 (so program the FEC to ignore it). 2467 2468- CONFIG_RMII 2469 Enable RMII mode for all FECs. 2470 Note that this is a global option, we can't 2471 have one FEC in standard MII mode and another in RMII mode. 2472 2473- CONFIG_CRC32_VERIFY 2474 Add a verify option to the crc32 command. 2475 The syntax is: 2476 2477 => crc32 -v <address> <count> <crc32> 2478 2479 Where address/count indicate a memory area 2480 and crc32 is the correct crc32 which the 2481 area should have. 2482 2483- CONFIG_LOOPW 2484 Add the "loopw" memory command. This only takes effect if 2485 the memory commands are activated globally (CONFIG_CMD_MEM). 2486 2487- CONFIG_MX_CYCLIC 2488 Add the "mdc" and "mwc" memory commands. These are cyclic 2489 "md/mw" commands. 2490 Examples: 2491 2492 => mdc.b 10 4 500 2493 This command will print 4 bytes (10,11,12,13) each 500 ms. 2494 2495 => mwc.l 100 12345678 10 2496 This command will write 12345678 to address 100 all 10 ms. 2497 2498 This only takes effect if the memory commands are activated 2499 globally (CONFIG_CMD_MEM). 2500 2501- CONFIG_SKIP_LOWLEVEL_INIT 2502- CONFIG_SKIP_RELOCATE_UBOOT 2503 2504 [ARM only] If these variables are defined, then 2505 certain low level initializations (like setting up 2506 the memory controller) are omitted and/or U-Boot does 2507 not relocate itself into RAM. 2508 Normally these variables MUST NOT be defined. The 2509 only exception is when U-Boot is loaded (to RAM) by 2510 some other boot loader or by a debugger which 2511 performs these intializations itself. 2512 2513 2514Building the Software: 2515====================== 2516 2517Building U-Boot has been tested in several native build environments 2518and in many different cross environments. Of course we cannot support 2519all possibly existing versions of cross development tools in all 2520(potentially obsolete) versions. In case of tool chain problems we 2521recommend to use the ELDK (see http://www.denx.de/wiki/DULG/ELDK) 2522which is extensively used to build and test U-Boot. 2523 2524If you are not using a native environment, it is assumed that you 2525have GNU cross compiling tools available in your path. In this case, 2526you must set the environment variable CROSS_COMPILE in your shell. 2527Note that no changes to the Makefile or any other source files are 2528necessary. For example using the ELDK on a 4xx CPU, please enter: 2529 2530 $ CROSS_COMPILE=ppc_4xx- 2531 $ export CROSS_COMPILE 2532 2533U-Boot is intended to be simple to build. After installing the 2534sources you must configure U-Boot for one specific board type. This 2535is done by typing: 2536 2537 make NAME_config 2538 2539where "NAME_config" is the name of one of the existing configu- 2540rations; see the main Makefile for supported names. 2541 2542Note: for some board special configuration names may exist; check if 2543 additional information is available from the board vendor; for 2544 instance, the TQM823L systems are available without (standard) 2545 or with LCD support. You can select such additional "features" 2546 when chosing the configuration, i. e. 2547 2548 make TQM823L_config 2549 - will configure for a plain TQM823L, i. e. no LCD support 2550 2551 make TQM823L_LCD_config 2552 - will configure for a TQM823L with U-Boot console on LCD 2553 2554 etc. 2555 2556 2557Finally, type "make all", and you should get some working U-Boot 2558images ready for download to / installation on your system: 2559 2560- "u-boot.bin" is a raw binary image 2561- "u-boot" is an image in ELF binary format 2562- "u-boot.srec" is in Motorola S-Record format 2563 2564By default the build is performed locally and the objects are saved 2565in the source directory. One of the two methods can be used to change 2566this behavior and build U-Boot to some external directory: 2567 25681. Add O= to the make command line invocations: 2569 2570 make O=/tmp/build distclean 2571 make O=/tmp/build NAME_config 2572 make O=/tmp/build all 2573 25742. Set environment variable BUILD_DIR to point to the desired location: 2575 2576 export BUILD_DIR=/tmp/build 2577 make distclean 2578 make NAME_config 2579 make all 2580 2581Note that the command line "O=" setting overrides the BUILD_DIR environment 2582variable. 2583 2584 2585Please be aware that the Makefiles assume you are using GNU make, so 2586for instance on NetBSD you might need to use "gmake" instead of 2587native "make". 2588 2589 2590If the system board that you have is not listed, then you will need 2591to port U-Boot to your hardware platform. To do this, follow these 2592steps: 2593 25941. Add a new configuration option for your board to the toplevel 2595 "Makefile" and to the "MAKEALL" script, using the existing 2596 entries as examples. Note that here and at many other places 2597 boards and other names are listed in alphabetical sort order. Please 2598 keep this order. 25992. Create a new directory to hold your board specific code. Add any 2600 files you need. In your board directory, you will need at least 2601 the "Makefile", a "<board>.c", "flash.c" and "u-boot.lds". 26023. Create a new configuration file "include/configs/<board>.h" for 2603 your board 26043. If you're porting U-Boot to a new CPU, then also create a new 2605 directory to hold your CPU specific code. Add any files you need. 26064. Run "make <board>_config" with your new name. 26075. Type "make", and you should get a working "u-boot.srec" file 2608 to be installed on your target system. 26096. Debug and solve any problems that might arise. 2610 [Of course, this last step is much harder than it sounds.] 2611 2612 2613Testing of U-Boot Modifications, Ports to New Hardware, etc.: 2614============================================================== 2615 2616If you have modified U-Boot sources (for instance added a new board 2617or support for new devices, a new CPU, etc.) you are expected to 2618provide feedback to the other developers. The feedback normally takes 2619the form of a "patch", i. e. a context diff against a certain (latest 2620official or latest in the git repository) version of U-Boot sources. 2621 2622But before you submit such a patch, please verify that your modifi- 2623cation did not break existing code. At least make sure that *ALL* of 2624the supported boards compile WITHOUT ANY compiler warnings. To do so, 2625just run the "MAKEALL" script, which will configure and build U-Boot 2626for ALL supported system. Be warned, this will take a while. You can 2627select which (cross) compiler to use by passing a `CROSS_COMPILE' 2628environment variable to the script, i. e. to use the ELDK cross tools 2629you can type 2630 2631 CROSS_COMPILE=ppc_8xx- MAKEALL 2632 2633or to build on a native PowerPC system you can type 2634 2635 CROSS_COMPILE=' ' MAKEALL 2636 2637When using the MAKEALL script, the default behaviour is to build 2638U-Boot in the source directory. This location can be changed by 2639setting the BUILD_DIR environment variable. Also, for each target 2640built, the MAKEALL script saves two log files (<target>.ERR and 2641<target>.MAKEALL) in the <source dir>/LOG directory. This default 2642location can be changed by setting the MAKEALL_LOGDIR environment 2643variable. For example: 2644 2645 export BUILD_DIR=/tmp/build 2646 export MAKEALL_LOGDIR=/tmp/log 2647 CROSS_COMPILE=ppc_8xx- MAKEALL 2648 2649With the above settings build objects are saved in the /tmp/build, 2650log files are saved in the /tmp/log and the source tree remains clean 2651during the whole build process. 2652 2653 2654See also "U-Boot Porting Guide" below. 2655 2656 2657Monitor Commands - Overview: 2658============================ 2659 2660go - start application at address 'addr' 2661run - run commands in an environment variable 2662bootm - boot application image from memory 2663bootp - boot image via network using BootP/TFTP protocol 2664tftpboot- boot image via network using TFTP protocol 2665 and env variables "ipaddr" and "serverip" 2666 (and eventually "gatewayip") 2667rarpboot- boot image via network using RARP/TFTP protocol 2668diskboot- boot from IDE devicebootd - boot default, i.e., run 'bootcmd' 2669loads - load S-Record file over serial line 2670loadb - load binary file over serial line (kermit mode) 2671md - memory display 2672mm - memory modify (auto-incrementing) 2673nm - memory modify (constant address) 2674mw - memory write (fill) 2675cp - memory copy 2676cmp - memory compare 2677crc32 - checksum calculation 2678imd - i2c memory display 2679imm - i2c memory modify (auto-incrementing) 2680inm - i2c memory modify (constant address) 2681imw - i2c memory write (fill) 2682icrc32 - i2c checksum calculation 2683iprobe - probe to discover valid I2C chip addresses 2684iloop - infinite loop on address range 2685isdram - print SDRAM configuration information 2686sspi - SPI utility commands 2687base - print or set address offset 2688printenv- print environment variables 2689setenv - set environment variables 2690saveenv - save environment variables to persistent storage 2691protect - enable or disable FLASH write protection 2692erase - erase FLASH memory 2693flinfo - print FLASH memory information 2694bdinfo - print Board Info structure 2695iminfo - print header information for application image 2696coninfo - print console devices and informations 2697ide - IDE sub-system 2698loop - infinite loop on address range 2699loopw - infinite write loop on address range 2700mtest - simple RAM test 2701icache - enable or disable instruction cache 2702dcache - enable or disable data cache 2703reset - Perform RESET of the CPU 2704echo - echo args to console 2705version - print monitor version 2706help - print online help 2707? - alias for 'help' 2708 2709 2710Monitor Commands - Detailed Description: 2711======================================== 2712 2713TODO. 2714 2715For now: just type "help <command>". 2716 2717 2718Environment Variables: 2719====================== 2720 2721U-Boot supports user configuration using Environment Variables which 2722can be made persistent by saving to Flash memory. 2723 2724Environment Variables are set using "setenv", printed using 2725"printenv", and saved to Flash using "saveenv". Using "setenv" 2726without a value can be used to delete a variable from the 2727environment. As long as you don't save the environment you are 2728working with an in-memory copy. In case the Flash area containing the 2729environment is erased by accident, a default environment is provided. 2730 2731Some configuration options can be set using Environment Variables: 2732 2733 baudrate - see CONFIG_BAUDRATE 2734 2735 bootdelay - see CONFIG_BOOTDELAY 2736 2737 bootcmd - see CONFIG_BOOTCOMMAND 2738 2739 bootargs - Boot arguments when booting an RTOS image 2740 2741 bootfile - Name of the image to load with TFTP 2742 2743 autoload - if set to "no" (any string beginning with 'n'), 2744 "bootp" will just load perform a lookup of the 2745 configuration from the BOOTP server, but not try to 2746 load any image using TFTP 2747 2748 autoscript - if set to "yes" commands like "loadb", "loady", 2749 "bootp", "tftpb", "rarpboot" and "nfs" will attempt 2750 to automatically run script images (by internally 2751 calling "autoscript"). 2752 2753 autoscript_uname - if script image is in a format (FIT) this 2754 variable is used to get script subimage unit name. 2755 2756 autostart - if set to "yes", an image loaded using the "bootp", 2757 "rarpboot", "tftpboot" or "diskboot" commands will 2758 be automatically started (by internally calling 2759 "bootm") 2760 2761 If set to "no", a standalone image passed to the 2762 "bootm" command will be copied to the load address 2763 (and eventually uncompressed), but NOT be started. 2764 This can be used to load and uncompress arbitrary 2765 data. 2766 2767 i2cfast - (PPC405GP|PPC405EP only) 2768 if set to 'y' configures Linux I2C driver for fast 2769 mode (400kHZ). This environment variable is used in 2770 initialization code. So, for changes to be effective 2771 it must be saved and board must be reset. 2772 2773 initrd_high - restrict positioning of initrd images: 2774 If this variable is not set, initrd images will be 2775 copied to the highest possible address in RAM; this 2776 is usually what you want since it allows for 2777 maximum initrd size. If for some reason you want to 2778 make sure that the initrd image is loaded below the 2779 CFG_BOOTMAPSZ limit, you can set this environment 2780 variable to a value of "no" or "off" or "0". 2781 Alternatively, you can set it to a maximum upper 2782 address to use (U-Boot will still check that it 2783 does not overwrite the U-Boot stack and data). 2784 2785 For instance, when you have a system with 16 MB 2786 RAM, and want to reserve 4 MB from use by Linux, 2787 you can do this by adding "mem=12M" to the value of 2788 the "bootargs" variable. However, now you must make 2789 sure that the initrd image is placed in the first 2790 12 MB as well - this can be done with 2791 2792 setenv initrd_high 00c00000 2793 2794 If you set initrd_high to 0xFFFFFFFF, this is an 2795 indication to U-Boot that all addresses are legal 2796 for the Linux kernel, including addresses in flash 2797 memory. In this case U-Boot will NOT COPY the 2798 ramdisk at all. This may be useful to reduce the 2799 boot time on your system, but requires that this 2800 feature is supported by your Linux kernel. 2801 2802 ipaddr - IP address; needed for tftpboot command 2803 2804 loadaddr - Default load address for commands like "bootp", 2805 "rarpboot", "tftpboot", "loadb" or "diskboot" 2806 2807 loads_echo - see CONFIG_LOADS_ECHO 2808 2809 serverip - TFTP server IP address; needed for tftpboot command 2810 2811 bootretry - see CONFIG_BOOT_RETRY_TIME 2812 2813 bootdelaykey - see CONFIG_AUTOBOOT_DELAY_STR 2814 2815 bootstopkey - see CONFIG_AUTOBOOT_STOP_STR 2816 2817 ethprime - When CONFIG_NET_MULTI is enabled controls which 2818 interface is used first. 2819 2820 ethact - When CONFIG_NET_MULTI is enabled controls which 2821 interface is currently active. For example you 2822 can do the following 2823 2824 => setenv ethact FEC ETHERNET 2825 => ping 192.168.0.1 # traffic sent on FEC ETHERNET 2826 => setenv ethact SCC ETHERNET 2827 => ping 10.0.0.1 # traffic sent on SCC ETHERNET 2828 2829 ethrotate - When set to "no" U-Boot does not go through all 2830 available network interfaces. 2831 It just stays at the currently selected interface. 2832 2833 netretry - When set to "no" each network operation will 2834 either succeed or fail without retrying. 2835 When set to "once" the network operation will 2836 fail when all the available network interfaces 2837 are tried once without success. 2838 Useful on scripts which control the retry operation 2839 themselves. 2840 2841 npe_ucode - see CONFIG_IXP4XX_NPE_EXT_UCOD 2842 if set load address for the npe microcode 2843 2844 tftpsrcport - If this is set, the value is used for TFTP's 2845 UDP source port. 2846 2847 tftpdstport - If this is set, the value is used for TFTP's UDP 2848 destination port instead of the Well Know Port 69. 2849 2850 vlan - When set to a value < 4095 the traffic over 2851 ethernet is encapsulated/received over 802.1q 2852 VLAN tagged frames. 2853 2854The following environment variables may be used and automatically 2855updated by the network boot commands ("bootp" and "rarpboot"), 2856depending the information provided by your boot server: 2857 2858 bootfile - see above 2859 dnsip - IP address of your Domain Name Server 2860 dnsip2 - IP address of your secondary Domain Name Server 2861 gatewayip - IP address of the Gateway (Router) to use 2862 hostname - Target hostname 2863 ipaddr - see above 2864 netmask - Subnet Mask 2865 rootpath - Pathname of the root filesystem on the NFS server 2866 serverip - see above 2867 2868 2869There are two special Environment Variables: 2870 2871 serial# - contains hardware identification information such 2872 as type string and/or serial number 2873 ethaddr - Ethernet address 2874 2875These variables can be set only once (usually during manufacturing of 2876the board). U-Boot refuses to delete or overwrite these variables 2877once they have been set once. 2878 2879 2880Further special Environment Variables: 2881 2882 ver - Contains the U-Boot version string as printed 2883 with the "version" command. This variable is 2884 readonly (see CONFIG_VERSION_VARIABLE). 2885 2886 2887Please note that changes to some configuration parameters may take 2888only effect after the next boot (yes, that's just like Windoze :-). 2889 2890 2891Command Line Parsing: 2892===================== 2893 2894There are two different command line parsers available with U-Boot: 2895the old "simple" one, and the much more powerful "hush" shell: 2896 2897Old, simple command line parser: 2898-------------------------------- 2899 2900- supports environment variables (through setenv / saveenv commands) 2901- several commands on one line, separated by ';' 2902- variable substitution using "... ${name} ..." syntax 2903- special characters ('$', ';') can be escaped by prefixing with '\', 2904 for example: 2905 setenv bootcmd bootm \${address} 2906- You can also escape text by enclosing in single apostrophes, for example: 2907 setenv addip 'setenv bootargs $bootargs ip=$ipaddr:$serverip:$gatewayip:$netmask:$hostname::off' 2908 2909Hush shell: 2910----------- 2911 2912- similar to Bourne shell, with control structures like 2913 if...then...else...fi, for...do...done; while...do...done, 2914 until...do...done, ... 2915- supports environment ("global") variables (through setenv / saveenv 2916 commands) and local shell variables (through standard shell syntax 2917 "name=value"); only environment variables can be used with "run" 2918 command 2919 2920General rules: 2921-------------- 2922 2923(1) If a command line (or an environment variable executed by a "run" 2924 command) contains several commands separated by semicolon, and 2925 one of these commands fails, then the remaining commands will be 2926 executed anyway. 2927 2928(2) If you execute several variables with one call to run (i. e. 2929 calling run with a list af variables as arguments), any failing 2930 command will cause "run" to terminate, i. e. the remaining 2931 variables are not executed. 2932 2933Note for Redundant Ethernet Interfaces: 2934======================================= 2935 2936Some boards come with redundant ethernet interfaces; U-Boot supports 2937such configurations and is capable of automatic selection of a 2938"working" interface when needed. MAC assignment works as follows: 2939 2940Network interfaces are numbered eth0, eth1, eth2, ... Corresponding 2941MAC addresses can be stored in the environment as "ethaddr" (=>eth0), 2942"eth1addr" (=>eth1), "eth2addr", ... 2943 2944If the network interface stores some valid MAC address (for instance 2945in SROM), this is used as default address if there is NO correspon- 2946ding setting in the environment; if the corresponding environment 2947variable is set, this overrides the settings in the card; that means: 2948 2949o If the SROM has a valid MAC address, and there is no address in the 2950 environment, the SROM's address is used. 2951 2952o If there is no valid address in the SROM, and a definition in the 2953 environment exists, then the value from the environment variable is 2954 used. 2955 2956o If both the SROM and the environment contain a MAC address, and 2957 both addresses are the same, this MAC address is used. 2958 2959o If both the SROM and the environment contain a MAC address, and the 2960 addresses differ, the value from the environment is used and a 2961 warning is printed. 2962 2963o If neither SROM nor the environment contain a MAC address, an error 2964 is raised. 2965 2966 2967Image Formats: 2968============== 2969 2970U-Boot is capable of booting (and performing other auxiliary operations on) 2971images in two formats: 2972 2973New uImage format (FIT) 2974----------------------- 2975 2976Flexible and powerful format based on Flattened Image Tree -- FIT (similar 2977to Flattened Device Tree). It allows the use of images with multiple 2978components (several kernels, ramdisks, etc.), with contents protected by 2979SHA1, MD5 or CRC32. More details are found in the doc/uImage.FIT directory. 2980 2981 2982Old uImage format 2983----------------- 2984 2985Old image format is based on binary files which can be basically anything, 2986preceded by a special header; see the definitions in include/image.h for 2987details; basically, the header defines the following image properties: 2988 2989* Target Operating System (Provisions for OpenBSD, NetBSD, FreeBSD, 2990 4.4BSD, Linux, SVR4, Esix, Solaris, Irix, SCO, Dell, NCR, VxWorks, 2991 LynxOS, pSOS, QNX, RTEMS, ARTOS; 2992 Currently supported: Linux, NetBSD, VxWorks, QNX, RTEMS, ARTOS, LynxOS). 2993* Target CPU Architecture (Provisions for Alpha, ARM, AVR32, Intel x86, 2994 IA64, MIPS, NIOS, PowerPC, IBM S390, SuperH, Sparc, Sparc 64 Bit; 2995 Currently supported: ARM, AVR32, Intel x86, MIPS, NIOS, PowerPC). 2996* Compression Type (uncompressed, gzip, bzip2) 2997* Load Address 2998* Entry Point 2999* Image Name 3000* Image Timestamp 3001 3002The header is marked by a special Magic Number, and both the header 3003and the data portions of the image are secured against corruption by 3004CRC32 checksums. 3005 3006 3007Linux Support: 3008============== 3009 3010Although U-Boot should support any OS or standalone application 3011easily, the main focus has always been on Linux during the design of 3012U-Boot. 3013 3014U-Boot includes many features that so far have been part of some 3015special "boot loader" code within the Linux kernel. Also, any 3016"initrd" images to be used are no longer part of one big Linux image; 3017instead, kernel and "initrd" are separate images. This implementation 3018serves several purposes: 3019 3020- the same features can be used for other OS or standalone 3021 applications (for instance: using compressed images to reduce the 3022 Flash memory footprint) 3023 3024- it becomes much easier to port new Linux kernel versions because 3025 lots of low-level, hardware dependent stuff are done by U-Boot 3026 3027- the same Linux kernel image can now be used with different "initrd" 3028 images; of course this also means that different kernel images can 3029 be run with the same "initrd". This makes testing easier (you don't 3030 have to build a new "zImage.initrd" Linux image when you just 3031 change a file in your "initrd"). Also, a field-upgrade of the 3032 software is easier now. 3033 3034 3035Linux HOWTO: 3036============ 3037 3038Porting Linux to U-Boot based systems: 3039--------------------------------------- 3040 3041U-Boot cannot save you from doing all the necessary modifications to 3042configure the Linux device drivers for use with your target hardware 3043(no, we don't intend to provide a full virtual machine interface to 3044Linux :-). 3045 3046But now you can ignore ALL boot loader code (in arch/ppc/mbxboot). 3047 3048Just make sure your machine specific header file (for instance 3049include/asm-ppc/tqm8xx.h) includes the same definition of the Board 3050Information structure as we define in include/u-boot.h, and make 3051sure that your definition of IMAP_ADDR uses the same value as your 3052U-Boot configuration in CFG_IMMR. 3053 3054 3055Configuring the Linux kernel: 3056----------------------------- 3057 3058No specific requirements for U-Boot. Make sure you have some root 3059device (initial ramdisk, NFS) for your target system. 3060 3061 3062Building a Linux Image: 3063----------------------- 3064 3065With U-Boot, "normal" build targets like "zImage" or "bzImage" are 3066not used. If you use recent kernel source, a new build target 3067"uImage" will exist which automatically builds an image usable by 3068U-Boot. Most older kernels also have support for a "pImage" target, 3069which was introduced for our predecessor project PPCBoot and uses a 3070100% compatible format. 3071 3072Example: 3073 3074 make TQM850L_config 3075 make oldconfig 3076 make dep 3077 make uImage 3078 3079The "uImage" build target uses a special tool (in 'tools/mkimage') to 3080encapsulate a compressed Linux kernel image with header information, 3081CRC32 checksum etc. for use with U-Boot. This is what we are doing: 3082 3083* build a standard "vmlinux" kernel image (in ELF binary format): 3084 3085* convert the kernel into a raw binary image: 3086 3087 ${CROSS_COMPILE}-objcopy -O binary \ 3088 -R .note -R .comment \ 3089 -S vmlinux linux.bin 3090 3091* compress the binary image: 3092 3093 gzip -9 linux.bin 3094 3095* package compressed binary image for U-Boot: 3096 3097 mkimage -A ppc -O linux -T kernel -C gzip \ 3098 -a 0 -e 0 -n "Linux Kernel Image" \ 3099 -d linux.bin.gz uImage 3100 3101 3102The "mkimage" tool can also be used to create ramdisk images for use 3103with U-Boot, either separated from the Linux kernel image, or 3104combined into one file. "mkimage" encapsulates the images with a 64 3105byte header containing information about target architecture, 3106operating system, image type, compression method, entry points, time 3107stamp, CRC32 checksums, etc. 3108 3109"mkimage" can be called in two ways: to verify existing images and 3110print the header information, or to build new images. 3111 3112In the first form (with "-l" option) mkimage lists the information 3113contained in the header of an existing U-Boot image; this includes 3114checksum verification: 3115 3116 tools/mkimage -l image 3117 -l ==> list image header information 3118 3119The second form (with "-d" option) is used to build a U-Boot image 3120from a "data file" which is used as image payload: 3121 3122 tools/mkimage -A arch -O os -T type -C comp -a addr -e ep \ 3123 -n name -d data_file image 3124 -A ==> set architecture to 'arch' 3125 -O ==> set operating system to 'os' 3126 -T ==> set image type to 'type' 3127 -C ==> set compression type 'comp' 3128 -a ==> set load address to 'addr' (hex) 3129 -e ==> set entry point to 'ep' (hex) 3130 -n ==> set image name to 'name' 3131 -d ==> use image data from 'datafile' 3132 3133Right now, all Linux kernels for PowerPC systems use the same load 3134address (0x00000000), but the entry point address depends on the 3135kernel version: 3136 3137- 2.2.x kernels have the entry point at 0x0000000C, 3138- 2.3.x and later kernels have the entry point at 0x00000000. 3139 3140So a typical call to build a U-Boot image would read: 3141 3142 -> tools/mkimage -n '2.4.4 kernel for TQM850L' \ 3143 > -A ppc -O linux -T kernel -C gzip -a 0 -e 0 \ 3144 > -d /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/ppc/coffboot/vmlinux.gz \ 3145 > examples/uImage.TQM850L 3146 Image Name: 2.4.4 kernel for TQM850L 3147 Created: Wed Jul 19 02:34:59 2000 3148 Image Type: PowerPC Linux Kernel Image (gzip compressed) 3149 Data Size: 335725 Bytes = 327.86 kB = 0.32 MB 3150 Load Address: 0x00000000 3151 Entry Point: 0x00000000 3152 3153To verify the contents of the image (or check for corruption): 3154 3155 -> tools/mkimage -l examples/uImage.TQM850L 3156 Image Name: 2.4.4 kernel for TQM850L 3157 Created: Wed Jul 19 02:34:59 2000 3158 Image Type: PowerPC Linux Kernel Image (gzip compressed) 3159 Data Size: 335725 Bytes = 327.86 kB = 0.32 MB 3160 Load Address: 0x00000000 3161 Entry Point: 0x00000000 3162 3163NOTE: for embedded systems where boot time is critical you can trade 3164speed for memory and install an UNCOMPRESSED image instead: this 3165needs more space in Flash, but boots much faster since it does not 3166need to be uncompressed: 3167 3168 -> gunzip /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/ppc/coffboot/vmlinux.gz 3169 -> tools/mkimage -n '2.4.4 kernel for TQM850L' \ 3170 > -A ppc -O linux -T kernel -C none -a 0 -e 0 \ 3171 > -d /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/ppc/coffboot/vmlinux \ 3172 > examples/uImage.TQM850L-uncompressed 3173 Image Name: 2.4.4 kernel for TQM850L 3174 Created: Wed Jul 19 02:34:59 2000 3175 Image Type: PowerPC Linux Kernel Image (uncompressed) 3176 Data Size: 792160 Bytes = 773.59 kB = 0.76 MB 3177 Load Address: 0x00000000 3178 Entry Point: 0x00000000 3179 3180 3181Similar you can build U-Boot images from a 'ramdisk.image.gz' file 3182when your kernel is intended to use an initial ramdisk: 3183 3184 -> tools/mkimage -n 'Simple Ramdisk Image' \ 3185 > -A ppc -O linux -T ramdisk -C gzip \ 3186 > -d /LinuxPPC/images/SIMPLE-ramdisk.image.gz examples/simple-initrd 3187 Image Name: Simple Ramdisk Image 3188 Created: Wed Jan 12 14:01:50 2000 3189 Image Type: PowerPC Linux RAMDisk Image (gzip compressed) 3190 Data Size: 566530 Bytes = 553.25 kB = 0.54 MB 3191 Load Address: 0x00000000 3192 Entry Point: 0x00000000 3193 3194 3195Installing a Linux Image: 3196------------------------- 3197 3198To downloading a U-Boot image over the serial (console) interface, 3199you must convert the image to S-Record format: 3200 3201 objcopy -I binary -O srec examples/image examples/image.srec 3202 3203The 'objcopy' does not understand the information in the U-Boot 3204image header, so the resulting S-Record file will be relative to 3205address 0x00000000. To load it to a given address, you need to 3206specify the target address as 'offset' parameter with the 'loads' 3207command. 3208 3209Example: install the image to address 0x40100000 (which on the 3210TQM8xxL is in the first Flash bank): 3211 3212 => erase 40100000 401FFFFF 3213 3214 .......... done 3215 Erased 8 sectors 3216 3217 => loads 40100000 3218 ## Ready for S-Record download ... 3219 ~>examples/image.srec 3220 1 2 3 4 5 6 7 8 9 10 11 12 13 ... 3221 ... 3222 15989 15990 15991 15992 3223 [file transfer complete] 3224 [connected] 3225 ## Start Addr = 0x00000000 3226 3227 3228You can check the success of the download using the 'iminfo' command; 3229this includes a checksum verification so you can be sure no data 3230corruption happened: 3231 3232 => imi 40100000 3233 3234 ## Checking Image at 40100000 ... 3235 Image Name: 2.2.13 for initrd on TQM850L 3236 Image Type: PowerPC Linux Kernel Image (gzip compressed) 3237 Data Size: 335725 Bytes = 327 kB = 0 MB 3238 Load Address: 00000000 3239 Entry Point: 0000000c 3240 Verifying Checksum ... OK 3241 3242 3243Boot Linux: 3244----------- 3245 3246The "bootm" command is used to boot an application that is stored in 3247memory (RAM or Flash). In case of a Linux kernel image, the contents 3248of the "bootargs" environment variable is passed to the kernel as 3249parameters. You can check and modify this variable using the 3250"printenv" and "setenv" commands: 3251 3252 3253 => printenv bootargs 3254 bootargs=root=/dev/ram 3255 3256 => setenv bootargs root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2 3257 3258 => printenv bootargs 3259 bootargs=root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2 3260 3261 => bootm 40020000 3262 ## Booting Linux kernel at 40020000 ... 3263 Image Name: 2.2.13 for NFS on TQM850L 3264 Image Type: PowerPC Linux Kernel Image (gzip compressed) 3265 Data Size: 381681 Bytes = 372 kB = 0 MB 3266 Load Address: 00000000 3267 Entry Point: 0000000c 3268 Verifying Checksum ... OK 3269 Uncompressing Kernel Image ... OK 3270 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 3271 Boot arguments: root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2 3272 time_init: decrementer frequency = 187500000/60 3273 Calibrating delay loop... 49.77 BogoMIPS 3274 Memory: 15208k available (700k kernel code, 444k data, 32k init) [c0000000,c1000000] 3275 ... 3276 3277If you want to boot a Linux kernel with initial ram disk, you pass 3278the memory addresses of both the kernel and the initrd image (PPBCOOT 3279format!) to the "bootm" command: 3280 3281 => imi 40100000 40200000 3282 3283 ## Checking Image at 40100000 ... 3284 Image Name: 2.2.13 for initrd on TQM850L 3285 Image Type: PowerPC Linux Kernel Image (gzip compressed) 3286 Data Size: 335725 Bytes = 327 kB = 0 MB 3287 Load Address: 00000000 3288 Entry Point: 0000000c 3289 Verifying Checksum ... OK 3290 3291 ## Checking Image at 40200000 ... 3292 Image Name: Simple Ramdisk Image 3293 Image Type: PowerPC Linux RAMDisk Image (gzip compressed) 3294 Data Size: 566530 Bytes = 553 kB = 0 MB 3295 Load Address: 00000000 3296 Entry Point: 00000000 3297 Verifying Checksum ... OK 3298 3299 => bootm 40100000 40200000 3300 ## Booting Linux kernel at 40100000 ... 3301 Image Name: 2.2.13 for initrd on TQM850L 3302 Image Type: PowerPC Linux Kernel Image (gzip compressed) 3303 Data Size: 335725 Bytes = 327 kB = 0 MB 3304 Load Address: 00000000 3305 Entry Point: 0000000c 3306 Verifying Checksum ... OK 3307 Uncompressing Kernel Image ... OK 3308 ## Loading RAMDisk Image at 40200000 ... 3309 Image Name: Simple Ramdisk Image 3310 Image Type: PowerPC Linux RAMDisk Image (gzip compressed) 3311 Data Size: 566530 Bytes = 553 kB = 0 MB 3312 Load Address: 00000000 3313 Entry Point: 00000000 3314 Verifying Checksum ... OK 3315 Loading Ramdisk ... OK 3316 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 3317 Boot arguments: root=/dev/ram 3318 time_init: decrementer frequency = 187500000/60 3319 Calibrating delay loop... 49.77 BogoMIPS 3320 ... 3321 RAMDISK: Compressed image found at block 0 3322 VFS: Mounted root (ext2 filesystem). 3323 3324 bash# 3325 3326Boot Linux and pass a flat device tree: 3327----------- 3328 3329First, U-Boot must be compiled with the appropriate defines. See the section 3330titled "Linux Kernel Interface" above for a more in depth explanation. The 3331following is an example of how to start a kernel and pass an updated 3332flat device tree: 3333 3334=> print oftaddr 3335oftaddr=0x300000 3336=> print oft 3337oft=oftrees/mpc8540ads.dtb 3338=> tftp $oftaddr $oft 3339Speed: 1000, full duplex 3340Using TSEC0 device 3341TFTP from server 192.168.1.1; our IP address is 192.168.1.101 3342Filename 'oftrees/mpc8540ads.dtb'. 3343Load address: 0x300000 3344Loading: # 3345done 3346Bytes transferred = 4106 (100a hex) 3347=> tftp $loadaddr $bootfile 3348Speed: 1000, full duplex 3349Using TSEC0 device 3350TFTP from server 192.168.1.1; our IP address is 192.168.1.2 3351Filename 'uImage'. 3352Load address: 0x200000 3353Loading:############ 3354done 3355Bytes transferred = 1029407 (fb51f hex) 3356=> print loadaddr 3357loadaddr=200000 3358=> print oftaddr 3359oftaddr=0x300000 3360=> bootm $loadaddr - $oftaddr 3361## Booting image at 00200000 ... 3362 Image Name: Linux-2.6.17-dirty 3363 Image Type: PowerPC Linux Kernel Image (gzip compressed) 3364 Data Size: 1029343 Bytes = 1005.2 kB 3365 Load Address: 00000000 3366 Entry Point: 00000000 3367 Verifying Checksum ... OK 3368 Uncompressing Kernel Image ... OK 3369Booting using flat device tree at 0x300000 3370Using MPC85xx ADS machine description 3371Memory CAM mapping: CAM0=256Mb, CAM1=256Mb, CAM2=0Mb residual: 0Mb 3372[snip] 3373 3374 3375More About U-Boot Image Types: 3376------------------------------ 3377 3378U-Boot supports the following image types: 3379 3380 "Standalone Programs" are directly runnable in the environment 3381 provided by U-Boot; it is expected that (if they behave 3382 well) you can continue to work in U-Boot after return from 3383 the Standalone Program. 3384 "OS Kernel Images" are usually images of some Embedded OS which 3385 will take over control completely. Usually these programs 3386 will install their own set of exception handlers, device 3387 drivers, set up the MMU, etc. - this means, that you cannot 3388 expect to re-enter U-Boot except by resetting the CPU. 3389 "RAMDisk Images" are more or less just data blocks, and their 3390 parameters (address, size) are passed to an OS kernel that is 3391 being started. 3392 "Multi-File Images" contain several images, typically an OS 3393 (Linux) kernel image and one or more data images like 3394 RAMDisks. This construct is useful for instance when you want 3395 to boot over the network using BOOTP etc., where the boot 3396 server provides just a single image file, but you want to get 3397 for instance an OS kernel and a RAMDisk image. 3398 3399 "Multi-File Images" start with a list of image sizes, each 3400 image size (in bytes) specified by an "uint32_t" in network 3401 byte order. This list is terminated by an "(uint32_t)0". 3402 Immediately after the terminating 0 follow the images, one by 3403 one, all aligned on "uint32_t" boundaries (size rounded up to 3404 a multiple of 4 bytes). 3405 3406 "Firmware Images" are binary images containing firmware (like 3407 U-Boot or FPGA images) which usually will be programmed to 3408 flash memory. 3409 3410 "Script files" are command sequences that will be executed by 3411 U-Boot's command interpreter; this feature is especially 3412 useful when you configure U-Boot to use a real shell (hush) 3413 as command interpreter. 3414 3415 3416Standalone HOWTO: 3417================= 3418 3419One of the features of U-Boot is that you can dynamically load and 3420run "standalone" applications, which can use some resources of 3421U-Boot like console I/O functions or interrupt services. 3422 3423Two simple examples are included with the sources: 3424 3425"Hello World" Demo: 3426------------------- 3427 3428'examples/hello_world.c' contains a small "Hello World" Demo 3429application; it is automatically compiled when you build U-Boot. 3430It's configured to run at address 0x00040004, so you can play with it 3431like that: 3432 3433 => loads 3434 ## Ready for S-Record download ... 3435 ~>examples/hello_world.srec 3436 1 2 3 4 5 6 7 8 9 10 11 ... 3437 [file transfer complete] 3438 [connected] 3439 ## Start Addr = 0x00040004 3440 3441 => go 40004 Hello World! This is a test. 3442 ## Starting application at 0x00040004 ... 3443 Hello World 3444 argc = 7 3445 argv[0] = "40004" 3446 argv[1] = "Hello" 3447 argv[2] = "World!" 3448 argv[3] = "This" 3449 argv[4] = "is" 3450 argv[5] = "a" 3451 argv[6] = "test." 3452 argv[7] = "<NULL>" 3453 Hit any key to exit ... 3454 3455 ## Application terminated, rc = 0x0 3456 3457Another example, which demonstrates how to register a CPM interrupt 3458handler with the U-Boot code, can be found in 'examples/timer.c'. 3459Here, a CPM timer is set up to generate an interrupt every second. 3460The interrupt service routine is trivial, just printing a '.' 3461character, but this is just a demo program. The application can be 3462controlled by the following keys: 3463 3464 ? - print current values og the CPM Timer registers 3465 b - enable interrupts and start timer 3466 e - stop timer and disable interrupts 3467 q - quit application 3468 3469 => loads 3470 ## Ready for S-Record download ... 3471 ~>examples/timer.srec 3472 1 2 3 4 5 6 7 8 9 10 11 ... 3473 [file transfer complete] 3474 [connected] 3475 ## Start Addr = 0x00040004 3476 3477 => go 40004 3478 ## Starting application at 0x00040004 ... 3479 TIMERS=0xfff00980 3480 Using timer 1 3481 tgcr @ 0xfff00980, tmr @ 0xfff00990, trr @ 0xfff00994, tcr @ 0xfff00998, tcn @ 0xfff0099c, ter @ 0xfff009b0 3482 3483Hit 'b': 3484 [q, b, e, ?] Set interval 1000000 us 3485 Enabling timer 3486Hit '?': 3487 [q, b, e, ?] ........ 3488 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0xef6, ter=0x0 3489Hit '?': 3490 [q, b, e, ?] . 3491 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x2ad4, ter=0x0 3492Hit '?': 3493 [q, b, e, ?] . 3494 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x1efc, ter=0x0 3495Hit '?': 3496 [q, b, e, ?] . 3497 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x169d, ter=0x0 3498Hit 'e': 3499 [q, b, e, ?] ...Stopping timer 3500Hit 'q': 3501 [q, b, e, ?] ## Application terminated, rc = 0x0 3502 3503 3504Minicom warning: 3505================ 3506 3507Over time, many people have reported problems when trying to use the 3508"minicom" terminal emulation program for serial download. I (wd) 3509consider minicom to be broken, and recommend not to use it. Under 3510Unix, I recommend to use C-Kermit for general purpose use (and 3511especially for kermit binary protocol download ("loadb" command), and 3512use "cu" for S-Record download ("loads" command). 3513 3514Nevertheless, if you absolutely want to use it try adding this 3515configuration to your "File transfer protocols" section: 3516 3517 Name Program Name U/D FullScr IO-Red. Multi 3518 X kermit /usr/bin/kermit -i -l %l -s Y U Y N N 3519 Y kermit /usr/bin/kermit -i -l %l -r N D Y N N 3520 3521 3522NetBSD Notes: 3523============= 3524 3525Starting at version 0.9.2, U-Boot supports NetBSD both as host 3526(build U-Boot) and target system (boots NetBSD/mpc8xx). 3527 3528Building requires a cross environment; it is known to work on 3529NetBSD/i386 with the cross-powerpc-netbsd-1.3 package (you will also 3530need gmake since the Makefiles are not compatible with BSD make). 3531Note that the cross-powerpc package does not install include files; 3532attempting to build U-Boot will fail because <machine/ansi.h> is 3533missing. This file has to be installed and patched manually: 3534 3535 # cd /usr/pkg/cross/powerpc-netbsd/include 3536 # mkdir powerpc 3537 # ln -s powerpc machine 3538 # cp /usr/src/sys/arch/powerpc/include/ansi.h powerpc/ansi.h 3539 # ${EDIT} powerpc/ansi.h ## must remove __va_list, _BSD_VA_LIST 3540 3541Native builds *don't* work due to incompatibilities between native 3542and U-Boot include files. 3543 3544Booting assumes that (the first part of) the image booted is a 3545stage-2 loader which in turn loads and then invokes the kernel 3546proper. Loader sources will eventually appear in the NetBSD source 3547tree (probably in sys/arc/mpc8xx/stand/u-boot_stage2/); in the 3548meantime, see ftp://ftp.denx.de/pub/u-boot/ppcboot_stage2.tar.gz 3549 3550 3551Implementation Internals: 3552========================= 3553 3554The following is not intended to be a complete description of every 3555implementation detail. However, it should help to understand the 3556inner workings of U-Boot and make it easier to port it to custom 3557hardware. 3558 3559 3560Initial Stack, Global Data: 3561--------------------------- 3562 3563The implementation of U-Boot is complicated by the fact that U-Boot 3564starts running out of ROM (flash memory), usually without access to 3565system RAM (because the memory controller is not initialized yet). 3566This means that we don't have writable Data or BSS segments, and BSS 3567is not initialized as zero. To be able to get a C environment working 3568at all, we have to allocate at least a minimal stack. Implementation 3569options for this are defined and restricted by the CPU used: Some CPU 3570models provide on-chip memory (like the IMMR area on MPC8xx and 3571MPC826x processors), on others (parts of) the data cache can be 3572locked as (mis-) used as memory, etc. 3573 3574 Chris Hallinan posted a good summary of these issues to the 3575 u-boot-users mailing list: 3576 3577 Subject: RE: [U-Boot-Users] RE: More On Memory Bank x (nothingness)? 3578 From: "Chris Hallinan" <clh@net1plus.com> 3579 Date: Mon, 10 Feb 2003 16:43:46 -0500 (22:43 MET) 3580 ... 3581 3582 Correct me if I'm wrong, folks, but the way I understand it 3583 is this: Using DCACHE as initial RAM for Stack, etc, does not 3584 require any physical RAM backing up the cache. The cleverness 3585 is that the cache is being used as a temporary supply of 3586 necessary storage before the SDRAM controller is setup. It's 3587 beyond the scope of this list to expain the details, but you 3588 can see how this works by studying the cache architecture and 3589 operation in the architecture and processor-specific manuals. 3590 3591 OCM is On Chip Memory, which I believe the 405GP has 4K. It 3592 is another option for the system designer to use as an 3593 initial stack/ram area prior to SDRAM being available. Either 3594 option should work for you. Using CS 4 should be fine if your 3595 board designers haven't used it for something that would 3596 cause you grief during the initial boot! It is frequently not 3597 used. 3598 3599 CFG_INIT_RAM_ADDR should be somewhere that won't interfere 3600 with your processor/board/system design. The default value 3601 you will find in any recent u-boot distribution in 3602 walnut.h should work for you. I'd set it to a value larger 3603 than your SDRAM module. If you have a 64MB SDRAM module, set 3604 it above 400_0000. Just make sure your board has no resources 3605 that are supposed to respond to that address! That code in 3606 start.S has been around a while and should work as is when 3607 you get the config right. 3608 3609 -Chris Hallinan 3610 DS4.COM, Inc. 3611 3612It is essential to remember this, since it has some impact on the C 3613code for the initialization procedures: 3614 3615* Initialized global data (data segment) is read-only. Do not attempt 3616 to write it. 3617 3618* Do not use any unitialized global data (or implicitely initialized 3619 as zero data - BSS segment) at all - this is undefined, initiali- 3620 zation is performed later (when relocating to RAM). 3621 3622* Stack space is very limited. Avoid big data buffers or things like 3623 that. 3624 3625Having only the stack as writable memory limits means we cannot use 3626normal global data to share information beween the code. But it 3627turned out that the implementation of U-Boot can be greatly 3628simplified by making a global data structure (gd_t) available to all 3629functions. We could pass a pointer to this data as argument to _all_ 3630functions, but this would bloat the code. Instead we use a feature of 3631the GCC compiler (Global Register Variables) to share the data: we 3632place a pointer (gd) to the global data into a register which we 3633reserve for this purpose. 3634 3635When choosing a register for such a purpose we are restricted by the 3636relevant (E)ABI specifications for the current architecture, and by 3637GCC's implementation. 3638 3639For PowerPC, the following registers have specific use: 3640 R1: stack pointer 3641 R2: reserved for system use 3642 R3-R4: parameter passing and return values 3643 R5-R10: parameter passing 3644 R13: small data area pointer 3645 R30: GOT pointer 3646 R31: frame pointer 3647 3648 (U-Boot also uses R14 as internal GOT pointer.) 3649 3650 ==> U-Boot will use R2 to hold a pointer to the global data 3651 3652 Note: on PPC, we could use a static initializer (since the 3653 address of the global data structure is known at compile time), 3654 but it turned out that reserving a register results in somewhat 3655 smaller code - although the code savings are not that big (on 3656 average for all boards 752 bytes for the whole U-Boot image, 3657 624 text + 127 data). 3658 3659On Blackfin, the normal C ABI (except for P5) is followed as documented here: 3660 http://docs.blackfin.uclinux.org/doku.php?id=application_binary_interface 3661 3662 ==> U-Boot will use P5 to hold a pointer to the global data 3663 3664On ARM, the following registers are used: 3665 3666 R0: function argument word/integer result 3667 R1-R3: function argument word 3668 R9: GOT pointer 3669 R10: stack limit (used only if stack checking if enabled) 3670 R11: argument (frame) pointer 3671 R12: temporary workspace 3672 R13: stack pointer 3673 R14: link register 3674 R15: program counter 3675 3676 ==> U-Boot will use R8 to hold a pointer to the global data 3677 3678NOTE: DECLARE_GLOBAL_DATA_PTR must be used with file-global scope, 3679or current versions of GCC may "optimize" the code too much. 3680 3681Memory Management: 3682------------------ 3683 3684U-Boot runs in system state and uses physical addresses, i.e. the 3685MMU is not used either for address mapping nor for memory protection. 3686 3687The available memory is mapped to fixed addresses using the memory 3688controller. In this process, a contiguous block is formed for each 3689memory type (Flash, SDRAM, SRAM), even when it consists of several 3690physical memory banks. 3691 3692U-Boot is installed in the first 128 kB of the first Flash bank (on 3693TQM8xxL modules this is the range 0x40000000 ... 0x4001FFFF). After 3694booting and sizing and initializing DRAM, the code relocates itself 3695to the upper end of DRAM. Immediately below the U-Boot code some 3696memory is reserved for use by malloc() [see CFG_MALLOC_LEN 3697configuration setting]. Below that, a structure with global Board 3698Info data is placed, followed by the stack (growing downward). 3699 3700Additionally, some exception handler code is copied to the low 8 kB 3701of DRAM (0x00000000 ... 0x00001FFF). 3702 3703So a typical memory configuration with 16 MB of DRAM could look like 3704this: 3705 3706 0x0000 0000 Exception Vector code 3707 : 3708 0x0000 1FFF 3709 0x0000 2000 Free for Application Use 3710 : 3711 : 3712 3713 : 3714 : 3715 0x00FB FF20 Monitor Stack (Growing downward) 3716 0x00FB FFAC Board Info Data and permanent copy of global data 3717 0x00FC 0000 Malloc Arena 3718 : 3719 0x00FD FFFF 3720 0x00FE 0000 RAM Copy of Monitor Code 3721 ... eventually: LCD or video framebuffer 3722 ... eventually: pRAM (Protected RAM - unchanged by reset) 3723 0x00FF FFFF [End of RAM] 3724 3725 3726System Initialization: 3727---------------------- 3728 3729In the reset configuration, U-Boot starts at the reset entry point 3730(on most PowerPC systens at address 0x00000100). Because of the reset 3731configuration for CS0# this is a mirror of the onboard Flash memory. 3732To be able to re-map memory U-Boot then jumps to its link address. 3733To be able to implement the initialization code in C, a (small!) 3734initial stack is set up in the internal Dual Ported RAM (in case CPUs 3735which provide such a feature like MPC8xx or MPC8260), or in a locked 3736part of the data cache. After that, U-Boot initializes the CPU core, 3737the caches and the SIU. 3738 3739Next, all (potentially) available memory banks are mapped using a 3740preliminary mapping. For example, we put them on 512 MB boundaries 3741(multiples of 0x20000000: SDRAM on 0x00000000 and 0x20000000, Flash 3742on 0x40000000 and 0x60000000, SRAM on 0x80000000). Then UPM A is 3743programmed for SDRAM access. Using the temporary configuration, a 3744simple memory test is run that determines the size of the SDRAM 3745banks. 3746 3747When there is more than one SDRAM bank, and the banks are of 3748different size, the largest is mapped first. For equal size, the first 3749bank (CS2#) is mapped first. The first mapping is always for address 37500x00000000, with any additional banks following immediately to create 3751contiguous memory starting from 0. 3752 3753Then, the monitor installs itself at the upper end of the SDRAM area 3754and allocates memory for use by malloc() and for the global Board 3755Info data; also, the exception vector code is copied to the low RAM 3756pages, and the final stack is set up. 3757 3758Only after this relocation will you have a "normal" C environment; 3759until that you are restricted in several ways, mostly because you are 3760running from ROM, and because the code will have to be relocated to a 3761new address in RAM. 3762 3763 3764U-Boot Porting Guide: 3765---------------------- 3766 3767[Based on messages by Jerry Van Baren in the U-Boot-Users mailing 3768list, October 2002] 3769 3770 3771int main (int argc, char *argv[]) 3772{ 3773 sighandler_t no_more_time; 3774 3775 signal (SIGALRM, no_more_time); 3776 alarm (PROJECT_DEADLINE - toSec (3 * WEEK)); 3777 3778 if (available_money > available_manpower) { 3779 pay consultant to port U-Boot; 3780 return 0; 3781 } 3782 3783 Download latest U-Boot source; 3784 3785 Subscribe to u-boot-users mailing list; 3786 3787 if (clueless) { 3788 email ("Hi, I am new to U-Boot, how do I get started?"); 3789 } 3790 3791 while (learning) { 3792 Read the README file in the top level directory; 3793 Read http://www.denx.de/twiki/bin/view/DULG/Manual ; 3794 Read the source, Luke; 3795 } 3796 3797 if (available_money > toLocalCurrency ($2500)) { 3798 Buy a BDI2000; 3799 } else { 3800 Add a lot of aggravation and time; 3801 } 3802 3803 Create your own board support subdirectory; 3804 3805 Create your own board config file; 3806 3807 while (!running) { 3808 do { 3809 Add / modify source code; 3810 } until (compiles); 3811 Debug; 3812 if (clueless) 3813 email ("Hi, I am having problems..."); 3814 } 3815 Send patch file to Wolfgang; 3816 3817 return 0; 3818} 3819 3820void no_more_time (int sig) 3821{ 3822 hire_a_guru(); 3823} 3824 3825 3826Coding Standards: 3827----------------- 3828 3829All contributions to U-Boot should conform to the Linux kernel 3830coding style; see the file "Documentation/CodingStyle" and the script 3831"scripts/Lindent" in your Linux kernel source directory. In sources 3832originating from U-Boot a style corresponding to "Lindent -pcs" (adding 3833spaces before parameters to function calls) is actually used. 3834 3835Source files originating from a different project (for example the 3836MTD subsystem) are generally exempt from these guidelines and are not 3837reformated to ease subsequent migration to newer versions of those 3838sources. 3839 3840Please note that U-Boot is implemented in C (and to some small parts in 3841Assembler); no C++ is used, so please do not use C++ style comments (//) 3842in your code. 3843 3844Please also stick to the following formatting rules: 3845- remove any trailing white space 3846- use TAB characters for indentation, not spaces 3847- make sure NOT to use DOS '\r\n' line feeds 3848- do not add more than 2 empty lines to source files 3849- do not add trailing empty lines to source files 3850 3851Submissions which do not conform to the standards may be returned 3852with a request to reformat the changes. 3853 3854 3855Submitting Patches: 3856------------------- 3857 3858Since the number of patches for U-Boot is growing, we need to 3859establish some rules. Submissions which do not conform to these rules 3860may be rejected, even when they contain important and valuable stuff. 3861 3862Patches shall be sent to the u-boot-users mailing list. 3863 3864Please see http://www.denx.de/wiki/UBoot/Patches for details. 3865 3866When you send a patch, please include the following information with 3867it: 3868 3869* For bug fixes: a description of the bug and how your patch fixes 3870 this bug. Please try to include a way of demonstrating that the 3871 patch actually fixes something. 3872 3873* For new features: a description of the feature and your 3874 implementation. 3875 3876* A CHANGELOG entry as plaintext (separate from the patch) 3877 3878* For major contributions, your entry to the CREDITS file 3879 3880* When you add support for a new board, don't forget to add this 3881 board to the MAKEALL script, too. 3882 3883* If your patch adds new configuration options, don't forget to 3884 document these in the README file. 3885 3886* The patch itself. If you are using git (which is *strongly* 3887 recommended) you can easily generate the patch using the 3888 "git-format-patch". If you then use "git-send-email" to send it to 3889 the U-Boot mailing list, you will avoid most of the common problems 3890 with some other mail clients. 3891 3892 If you cannot use git, use "diff -purN OLD NEW". If your version of 3893 diff does not support these options, then get the latest version of 3894 GNU diff. 3895 3896 The current directory when running this command shall be the parent 3897 directory of the U-Boot source tree (i. e. please make sure that 3898 your patch includes sufficient directory information for the 3899 affected files). 3900 3901 We prefer patches as plain text. MIME attachments are discouraged, 3902 and compressed attachments must not be used. 3903 3904* If one logical set of modifications affects or creates several 3905 files, all these changes shall be submitted in a SINGLE patch file. 3906 3907* Changesets that contain different, unrelated modifications shall be 3908 submitted as SEPARATE patches, one patch per changeset. 3909 3910 3911Notes: 3912 3913* Before sending the patch, run the MAKEALL script on your patched 3914 source tree and make sure that no errors or warnings are reported 3915 for any of the boards. 3916 3917* Keep your modifications to the necessary minimum: A patch 3918 containing several unrelated changes or arbitrary reformats will be 3919 returned with a request to re-formatting / split it. 3920 3921* If you modify existing code, make sure that your new code does not 3922 add to the memory footprint of the code ;-) Small is beautiful! 3923 When adding new features, these should compile conditionally only 3924 (using #ifdef), and the resulting code with the new feature 3925 disabled must not need more memory than the old code without your 3926 modification. 3927 3928* Remember that there is a size limit of 40 kB per message on the 3929 u-boot-users mailing list. Bigger patches will be moderated. If 3930 they are reasonable and not bigger than 100 kB, they will be 3931 acknowledged. Even bigger patches should be avoided. 3932